首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
With follow-on biologics essentially dead in the water in the US, the decision of the world's largest generics manufacturer to invest in a platform for enhancing protein pharmacokinetics could pay dividends.  相似文献   

2.
3.

Objective

To measure the prices and availability of selected medicines in Shaanxi Province after the implementation of new healthcare reform in 2009.

Methods

Data on the prices and availability of 47 medicines were collected from 50 public and 36 private sector medicine outlets in six regions of Shaanxi Province, Western China using a standardized methodology developed by the World Health Organization and Health Action International from September to October 2010. Medicine prices were compared with international reference prices to obtain a median price ratio. Affordability was measured as the number of days’ wages required for the lowest-paid unskilled government worker to purchase standard treatments for common conditions.

Findings

The mean availabilities of originator brands and lowest-priced generics were 8.9% and 26.5% in the public sector, and 18.1% and 43.6% in the private sector, respectively. The public sector procured generics and originator brands at median price ratios of 0.75 and 8.49, respectively, while patients paid 0.97 and 10.16. Final patient prices for lowest-priced generics and originator brands in the private sector were about 1.53 and 8.36 times their international retail prices, respectively. Public sector vendors applied high markups of 30.4% to generics, and 19.6% to originator brands. In the private sector, originator brands cost 390.7% more, on average, than their generic equivalents. Generic medicines were priced 17.3% higher in the private sector than the public sector. The lowest-paid government worker would need 0.1 day’s wages to purchase captopril for lowest-priced generics from private sector, while 6.6 days’ wages for losartan. For originator brands, the costs rise to 1.2 days’ wages for salbutamol inhaler and 15.6 days’ wages for omeprazole.

Conclusions

The prices, availability and affordability of medicines in China should be improved to ensure equitable access to basic medical treatments, especially for the poor. This requires multi-faceted interventions, as well as the review and refocusing of policies, regulations and educational interventions.  相似文献   

4.
Plants are complex living beings, extremely sensitive to environmental factors, continuously adapting to the ever changing environment. Emerging research document that plants sense, memorize, and process experiences and use this information for their adaptive behavior and evolution. As any other living and evolving systems, plants act as knowledge accumulating systems. Neuronal informational systems are behind this concept of organisms as knowledge accumulating systems because they allow the most rapid and efficient adaptive responses to changes in environment. Therefore, it should not be surprising that neuronal computation is not limited to animal brains but is used also by bacteria and plants. The journal, Plant Signaling & Behavior, was launched as a platform for exchanging information and fostering research on plant neurobiology in order to allow our understanding of plants in their whole integrated, communicative, and behavioral complexity.
I always go by official statistics because they are very carefully compounded and, even if they are false, we have no others …∼ Jaroslav Hašek, 1911
Key Words: plant neurobiology, sensory biology, behavior, biological complexity, evolution, signal integrationThis quotation of writer and mystificator Jaroslav Hašek is from his electorial speech aimed to get a seat in the Austro-Hungarian parliament for his imaginary political party ‘Moderate Progress within the Limits of the Law’ in 1911. It indicates how statistics can be misused for manipulation of public opinion, sometimes allegedly for general good. This quotation is partially relevant also for recent biology which is passing through a critical cross-road from reductionist-mechanistic concepts and methodologies towards the post-genomic, holistic, systems-based analysis of integrated and communicative hierarchic networks known as life processes.There is a message hidden in this Hašek''s aphorism. All those mathematical models, scientific theories and concepts, however appealing, harmonious and long-standing … but which do not correspond to reality …; inevitably will be ‘killed by ugly’ facts generated by scientific progress, and finally replaced by new models, theories, and concepts.1Despite the indisputable success of the reductionistic approach in providing many discoveries regarding single cells and their components, it is increasingly clear that promises of ‘mechanistic’ genocentric biology were just chimeras and that living organisms are much more complex than the sum of their constituents. Ernst Mayr, in his final opus, almost a testament published at his age of 100, strongly opposed the belief that the reductionism at the molecular level could help to explain the complexity of life. He stressed that the concept of biological “emergence”, which deals with the occurrence of unexpected features in complex living systems, is not fully accessible using only physical and chemical approaches.2Themes of hierarchy, continuity, and order dominated biology before the turn of the century, but these have in many cases been replaced by images of the workshop. Examples include such terms as ‘machineries’, ‘mechanistic understanding’, ‘mechanistic explanation’, ‘motors’, ‘machines’, ‘clocks’ etc. This shift may well reflect the characteristic style of our age. These concepts, although useful for mining of details, do not reveal the true complexity of life and can be misleading. Even a one-celled organism is made up of ‘millions’ of subcellular parts. Concerning the great complexity of unicellular creatures Ilya Prigogine (1973) wrote: “… but let us have no illusions, our research would still leave us quite unable to grasp the extreme complexity of the simplest of organism.”3 Moreover, eukaryotic cell proved to be, in fact, ‘cells within cell’,48 while there are numerous supracellular situations, the most dramatic one is represented by plants when all cells are interconnected via plasmodesmata into supracellular organism.6 All this collectively indicate that the currently valid ‘Cell Theory’ dogma is approaching its replacement with a new updated concept of a basic unit of eukaryotic life.68All those mathematical models, scientific theories and concepts, however appealing, harmonious and long-standing … but which do not correspond to reality …; inevitably will be ‘killed by ugly’ facts generated by scientific progress, and finally replaced by new models, theories, and concepts.Furthermore, genomes are much more complex and dynamic as we ever anticipated.9,10 They often have as much as 99% of non-coding DNA sequences,11 which is not ‘junk DNA’ but rather DNA which is part of multitask networks integrating coding DNA.12 In genomes exposed to stress (like mutations), changes are scored preferentially in non-coding sequences which regain a new balance by complex changes in genome composition and activity.9,10,13,14 There are several definitions regarding what is gene11 and molecular biologists and genetics are learning to be careful not to make strong conclusions from under-expression, knocking-out, or overexpression of any particular gene. It is increasingly clear that mutations in single genes are accompanied with altered expressions of other genes and non-coding DNA sequences too, and even subtle re-arrangements of chromatin structure and genome architecture are possible. The dynamic genome actively regains the lost balance, also via extensive re-shufflings of non-coding DNA.After complete sequencing of numerous genomes, it is clear that our understanding of what constitutes life and what distinguishes living biological systems from non-living chemical - biochemical systems is not much better than our understanding before the start of the genomics era some 60 years ago. Yet, it is also obvious that living systems, whether single cells or whole complex organisms like animals and plants, are not machines and automata which respond to external signals via a limited set of predefined responses and automatic reflexes. While humans and other animals, even insects, are already out of this ‘mechanistic’ trap15,16 which can be traced back to Descartes,17 plants are still considered to act only in predetermined automatic fashions, as mechanical devices devoid of any possibility for choice and planning of their activities. In contrast to machines, life systems are based on wet chemistry, being systems of hierarchical and dynamic integration, communication and emergence.1,18Recently, a critical mass of data has accumulated demanding reconsideration of this mechanistic view of plants.19,20 Plants are complex living beings, extremely sensitive to environmental factors and continuously adapting to the ever changing environment.21 In addition, plants respond to environmental stimuli as integrated organisms. Often, plants make important decisions, such as onset or breakage of dormancy and onset of flowering, which implicate some central or decentralized command center. Moreover, roots and shoots act in an integrated manner allowing dynamic balance of above-ground and below-ground organs. The journal, Plant Signaling & Behavior, was launched as a platform for exchange of information about the integration of discrete processes, including subcellular signalling integrated with higher-level processes. Signal integration and communication results in adaptive behavior of whole supracellular organisms, encompassing also complex, and still elusive, plant-plant, plant-insect, and plant-animal communications. Coordinated behavior based on sensory perception is inherent for neurobiological systems.22 Therefore, plants can be considered for neuronal individuals. Moreover, plants are also able to share knowledge perceived from environment with other plants, communicating both private and public messages.23,24 This implicates social learning and behavioral inheritance in plants too.After complete sequencing of numerous genomes, it is clear that our understanding of what constitutes life and what distinguishes living biological systems from non-living chemical - biochemical systems is not much better than our understanding before the start of genomics era some 60 years ago.

Behavior

  1. An activity of a defined organism: observable activity when measurable in terms of quantitative effects of the environment whether arising from internal or external stimuli.
  2. Anything that an organism does that involves action and response to stimulation.
(Webster Third New International Dictionary 1961).Neuronal informational systems allow the most rapid and efficient adaptive responses. Therefore, it should not be surprising that neuronal computation is not limited to animal brains but is used also by bacteria and plants.Some of our colleagues assert that plants do not exhibit any integrated neuronal principles.25 They maintain that plants do not show complex experience- or learning-based behavior. Plants, they aver, act rather as machines manifesting predefined reflexes. Yet recent studies indicate that even prokaryotic bacteria exhibit cognitive behavior26,27 and posses linguistic communication and rudimentary intelligence.2830 Therefore, it should not be too surprising that plants also show features of communication and even plant-specific cognition.19,20,31,3235 As any other living systems, plants act as ‘knowledge accumulating systems’.1 In fact, in order to adapt, all organisms continuously generate hypotheses about their environment via well formulated ‘questions’ which are solved by an increasing set of possible ‘answers’ in order to adapt.1 Neuronal informational systems are behind this concept of organisms as ‘knowledge accumulating systems’ because they allow the most rapid and efficient adaptive responses.22 As a consequence, neuronal computation is not limited to animal brains but is used also by bacteria and plants.Reductionistic approaches will continue to “atomize” biological systems. Nevertheless, the avalanche of new data will be in need of functional integration, winning adherents to the idea that plants have integrated signaling and communicative systems that endowed them with complex and adaptive behavior. We trust that Plant Signaling & Behavior, will become an important platform for exchange of these ideas. With progress of sciences, plants show more and more similarities to animals despite obviously plant-specific evolutionary origins, cellular basis, and multicellularity. We can just mention sexuality and sex organs, embryos, stem cells, immunity, circadian rhythms, hormonal and peptide signaling, sensory perception and bioelectricity including action potentials, communication and neurobiological aspects of signal integration. The whole picture strongly suggest that convergent evolution is much more important36,37 than currently envisioned in evolutionary theories.Reductionistic approaches will continue to “atomize” biological systems. Nevertheless, the avalanche of new data will be in need of functional integration, winning adherents to the idea that plants have integrated signaling and communicative systems that endowed them with complex and adaptive behavior.We have started with Jaroslav Hašek and we close with him as well. His quotation from 1911 is also a warning for future that we should stay open-minded. We should not slip into dogmatic ‘traps’ which have been so characteristic for the mechanistic and genocentric biology. Mathematics and computational biology are important tools, and surely will play decisive role in systems biology in the future. But they can be easily misinterpreted, and even misused. Plant systems biology, and the whole biology in general, must overcome dogmas of mechanistic genocentric biology. We hope that characterizing plants in their whole behavioral and communicative complexity will allow us to better understand what is life and how it emerged from chemical and biochemical complex systems.  相似文献   

5.
The opioid overdose epidemic is a major threat to the public’s health, resulting in the development and implementation of a variety of strategies to reduce fatal overdose [1-3]. Many strategies are focused on primary prevention and increased access to effective treatment, although the past decade has seen an exponential increase in harm reduction initiatives. To maximize identification of opportunities for intervention, initiatives focusing on prevention, access to effective treatment, and harm reduction are examined independently, although considerable overlap exists. Particular attention is given to harm reduction approaches, as increased public and political will have facilitated widespread implementation of several initiatives, including increased distribution of naloxone and policy changes designed to increase bystander assistance during a witnessed overdose [4-7].  相似文献   

6.
Angela Holder was to give the Grover Powers Memorial Lecture at the weekly Grand Rounds conducted by the Yale Department of Pediatrics on Wednesday, May 27, 2009, but unfortunately, she died one month earlier, on April 22, leaving behind her prepared address, “From Chattel to Consenter: Adolescents and Informed Consent,” which she had regarded as the pinnacle of a remarkable career, much of it spent at Yale. As the Grover Powers honoree, the department’s highest honor, Ms. Holder was only the fourth woman of 46 recipients and the first who was not a physician. On the date scheduled for her address, tributes were presented by her son, John Holder, and her longtime colleague, Dr. Robert Levine, co-founder of Yale’s Interdisciplinary Bioethics Center. Their comments follow Angela Holder’s completed but undelivered Grover Powers address. — Myron Genel, MD, Professor Emeritus of PediatricsUnder the common law of England and in the early years of the United States, a minor (defined as anyone under 21) was a chattel or possession of his or her father [1-4]. A father had the right to sue a physician who treated his son or daughter perfectly properly but without the father’s permission because such an intervention contravened the father’s right to control the child. Beginning in the early years of the 20th century, by the end of World War II and into the 1950s, the notion that a 16-year-old was a legally different entity from a 6-year-old gradually became law in all states.1 The first hospital unit for adolescents was created in 1951 at Boston Children’s Hospital, and the concept of “adolescent medicine” was born [5].As the law in this area currently defines “adolescent,” we are discussing someone 14 or older who may be (1) living at home with his or her parents; (2) Not living at home but still dependent on parents (i.e., a 16-year-old college freshman living in a dorm); (3) an “emancipated minor” who is married, emancipated by a court order, or a parent (other than in North Carolina), living away from home and self-supporting; or (4) a runaway or throwaway. At any time in this country, there are about 200,000 adolescents living on the streets with no adult supervision or involvement [6].Regardless of the age of the patient, informed consent consists of five elements: (1) An explanation of what will happen; (2) explanation of the risks; (3) explanation of the projected benefits; (4) alternatives (including doing nothing); and (5) why the physician thinks it should be done, which I interpret as a right to know one’s diagnosis. While the doctrine of “therapeutic privilege” means that in rare cases a physician may withhold some information from an adult patient if she or he believes the patient cannot “deal with the information,” there can never be any withholding of information from an adolescent. If the patient can’t deal with the information to be presented, then parents have to be involved and give permission to treat the adolescent.In some cases, when parents are involved, they do not want their adolescent to know his or her diagnosis. While this is usually not a good idea, it normally falls under the rubric of “professional judgment,” and the physician has every right to decide to follow the parents’ instruction if she agrees with it. In some situations, however, the adolescent must be told what his or her illness is, whether parents like it or not. For example, if a teenager is HIV positive, he or she must be told, must be instructed about safe sex, and must be asked to divulge the names of any sex partners. Parents who say, “Oh, no, don’t tell him, he would never do anything like that, so it doesn’t matter,” should be tactfully but firmly led to accept the fact that he may well have and if he hasn’t yet, he will certainly in the future. There has been at least one successful malpractice case in which the physician did not, at the request of the parents, tell his adolescent patient that he had HIV. The patient’s girlfriend caught it and sued the physician [7]. I feel sure there are many more cases like this that have been quietly settled and no one will ever hear about.Usually, questions about adolescents giving consent to treatments that their parents don’t know about involve outpatient treatment. In the first place, hospital administrators, who are much more interested in getting paid than they are in advancing the rights of autonomous adolescents, are not going to admit for a non-emergency problem a minor whose parent has not made some sort of financial arrangement to pay for it. Secondly, in most households, if Little Herman doesn’t show up for supper or throughout the evening, someone notices and a few telephone calls later discovers that Little Herman is in the hospital.  相似文献   

7.
Plant responses are coordinately controlled by both external and internal signals. Apt perception of pathogen attack and its appropriate conversion to internal signals ultimately determine the outcome of innate immunity. The present review predicts the involvement of unconventional ‘guard/decoy model’ in chickpea-Fusarium encounter. Rapid alkalinization factor is predicted to act as initial ‘Gatekeeper decoy’ counteracting fungal entry. Phospholipases and cystatins probably function as ‘Guardees’ being shielded by R gene(s). Serine Threonine Kinases decodes external pathogenic signals to in planta defense alarms. 14.3.3 provides clues to the wilt mechanism. The versatile sugars serve as signal generators and transmitters maintaining intra and inter cellular connectivity during stress.Key words: R gene, decoy, guardee, RALF, ROS, STK, 14.3.3, sugar, defense‘Survival for existence’ is the dictum followed by the entire living world. Similarly ‘survival of the fittest’ is nature''s preference. Owing to the extensive surveillance system of higher organisms resistance becomes the natural rule while susceptibility the exception.1 All living entities are being exposed to a plethora of interactions ranging from mutualism to antagonism.2 However the adaptive strategies opted by the plants are unique, versatile and still grossly unknown which have attracted the researchers since decades towards looking into the varied responses and diversification of plant adaptation.Plants are hosts to a large number of organisms such as symbiotic/pathogenic bacteria, phytopathogenic fungi, harmful viruses and nematodes. All have their own stratagem to gain over their host.3 However only the plant-fungal interaction with Chickpea-Fusarium case study in particular, shall be the focal area of the present review. Fungi are classified as necrotrophic and biotrophic according to their nutritional requirements.4 Necrotrophs apply ‘brute force’ by killing host cells and thriving on their dead remains while biotrophs prefer subtler ‘modus operandi’—the stealth mechanism used to derive nutrients from live host cells.5 Irrespective of the pathogen type and their mode of nutrition procurement, perception of attack lies central to effective induction of innate immunity in plants.  相似文献   

8.
Adapted from a whitepaper written for the Healthspan Campaign, sponsored by the Alliance for Aging Research.The economic peril posed by burgeoning federal debt has inspired fierce political wrangling in recent years. But the elephant in the room when the issue comes up is apolitical: the graying of baby boomers will relentlessly increase federal entitlement costs in coming years, especially those for healthcare, threatening ever larger budget deficits and federal debt. Indeed, annual deficits, largely due to healthcare spending, have put us on a path of unsustainable debt growth that could lead to “financial Armageddon,” according a recent analysis.1While the population’s rising median age is a key driver of healthcare costs, the way we buy time during our later years is arguably as important as aging itself. We’re living in an era of minor miracles with major costs, such as $10,000-per-dose cancer drugs that extend average survival by a few months. Barring drastic healthcare rationing, the use of such palliatives will continue to grow in tandem with the elderly population.But a much more efficient alternative is on the horizon: leaders in gerontology have concluded that anti-aging drugs capable of delaying all diseases of aging by about seven years are now technically feasible.2 Such drugs would be very broadly effective preventive medicines, staving off dementia, cancer, heart failure, frailty—and a myriad other old-age ills—in much the same way that drugs that lower blood pressure help postpone or avert heart disease.Unlike palliatives applied late in the course of diseases, the envisioned drugs would increase life expectancy by expanding the period of good health before the onset of disabling illness.3 A 2005 RAND Corp. study of the economic implications of 10 future medical advances that may benefit the elderly concluded that such anti-aging medicines would be by far the most cost-effective means of adding healthy life years among the analyzed technologies.4Interventions that slow aging in mammals have been known since the 1930s, when very low-calorie diets were found to extend rats’ lifespans. In 2009, researchers showed that rapamycin, a drug used to prevent rejection of transplanted organs, significantly extended lifespan in mice in a way reminiscent of calorie restriction.5 Intriguingly, this effect was observed in mice first put on the drug late in life, at 20 months of age, roughly equivalent to 60 years in humans; the life expectancy of the aged male rodents after initiation of the drug rose by 28% compared with controls, and that of the aged females by 38%. Many forms of age-dependent change occur more slowly in rapamycin-treated mice than in controls, suggesting that the drug has an authentic anti-aging effect.6Mutations, diets and drugs that slow aging in animals delay late-life morbidity, effectively increasing healthspan along with lifespan—they don’t extend the period of late-life decline, as feared by skeptics unfamiliar with the gerontology literature. For instance, mutations that delay aging in mice make them resistant to multiple diseases of aging, and the animals retain cognitive function later in life than do normal mice.7 A sizable fraction of human centenarians, who likely possess genetic loci that effectively slow aging, remain in remarkably good health nearly all their lives.8 The world’s longest-lived human population, natives of Japan’s Okinawa prefecture, suffer about 40% fewer hip fractures than U.S. peers.9 Remarkably, they also experience only half the rate of dementia, between 85 and 90, than their American peers do.10Increasing healthy life years with anti-aging drugs would slow projected increases in medical spending and deliver large, ongoing benefits across many sectors of the economy, helping to offset the costs of population aging, reduce future budget deficits and contain the federal debt. Healthier, longer-living people can stay in the workforce longer, preserving human capital that might otherwise be lost to disability. Healthier workers are physically and mentally more robust, making them more productive and less likely to lose workdays from illness. They’re motivated to make larger personal investments in developing their skills, because they expect to reap the benefits of such investments for longer periods. They save more for retirement, boosting capital formation that fuels economic growth. They pose lighter burdens on federal entitlement programs for seniors and contribute more in federal and state tax revenues. The combined effect of such factors is thought to explain why per-capita incomes of nations around the world have long risen in tandem with their populations’ life expectancies.11Unfortunately, there''s still a wide gap between research and development in gerontology. Realizing the promise of advances in aging science, for example, will likely require the identification of well-grounded biomarkers of aging to help assess purported anti-aging interventions’ efficacy in relatively short clinical trials12—human lifespan studies are untenable. Such research will require a major increase in funding for biogerontology studies.Basic research on aging has perennially garnered less than 1% of the NIH’s overall annual budget. Still, there have been some signs of growing support for stepping up such work. Recently, nearly 70 prominent scientists, including four Nobel laureates, endorsed a “healthspan campaign” to push for more research on aging as the common denominator of major diseases. Spearheaded by the Alliance for Aging Research, a nonprofit group in Washington, D.C., the campaign represents a significant preliminary step toward work that could pave the way for development of validated anti-aging drugs. Many more steps will be needed. But few, if any, areas for investing research dollars offer greater potential returns.  相似文献   

9.
《Endocrine practice》2018,24(2):195-204
Objective: Many healthcare providers in the U.S. are not familiar with follow-on biologics and biosimilars nor with their critical distinctions from standard generics. Our aim is to provide a detailed review of both, with a focus on insulins in the U.S. regulatory system.Methods: Literature has been reviewed to provide information on various aspects of biosimilars and a follow-on biologic of insulin. This will include structure, efficacy, cost, switching, and legal issues.Results: Biologic products are large, complex molecules derived from living sources. Follow-on biologics are copies of the original innovator biologics. It is not possible to copy their structure exactly, leading to possible differences in efficacy and safety. Thus, regulations involving biologics are complex. Follow-on biologics are regulated under two Federal laws until March 23, 2020: the Public Health Service Act (PHS Act) and the Federal Food, Drug, and Cosmetic Act. Biosimilars are follow-on biologics which have been approved via the PHS Act. They consist of those which are “highly similar” to the reference drug and those which are “expected” to produce the same clinical result as the reference drug (interchangeable biosimilars). Interchangeable biosimilars have been determined by the U.S. Food and Drug Administration to be substitutable by the pharmacist “without the intervention” of the prescriber. From the patient perspective, switching to a follow-on biologic may necessitate a change in delivery device, which may create issues for patient adherence and dosing.Conclusion: Although they present several challenges in terms of regulation and acceptance, follow-on biologics have the potential to significantly reduce costs for patients requiring insulin therapy.Abbreviations:BLA = biologics license applicationEU = European UnionFDA = Food and Drug AdministrationFD&C = Food, Drug, and CosmeticHCPCS = Healthcare Common Procedure Coding SystemINN = internatinal nonproprietary nameNDA = new drug applicationPHS = Public Health Service  相似文献   

10.
With the advent of molecular biology, genomics, and proteomics, the intersection between science and law has become increasingly significant. In addition to the ethical and legal concerns surrounding the collection, storage, and use of genomic data, patent disputes for new biotechnologies are quickly becoming part of mainstream business discussions. Under current patent law, new technologies cannot be patented if they are “obvious” changes to an existing patent. The definition of “obvious,” therefore, has a huge impact on determining whether a patent is granted. For example, are modifications to microarray protocols, popular in diagnostic medicine, considered “obvious” improvements of previous products? Also, inventions that are readily apparent now may not have been obvious when discovered. Polymerase chain reaction, or PCR, is now a common component of every biologist’s toolbox and seems like an obvious invention, though it clearly was not in 1983. Thus, there is also a temporal component that complicates the interpretation of an invention’s obviousness. The following article discusses how a recent Supreme Court decision has altered the definition of “obviousness” in patent disputes. By examining how the obviousness standard has changed, the article illuminates how legal definitions that seem wholly unrelated to biology or medicine could still potentially have enormous effects on these fieldsJust what is obvious or not is a question that has provoked substantial litigation in the Federal Circuit, the appellate court with special jurisdiction over patent law disputes. Under U.S. patent law, an inventor may not obtain a patent, which protects his invention from infringement by others, if the differences between the subject matter sought to be patented and the prior art are such that “the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill” in the patent’s subject matter area [1]. However, what was “obvious” at the time of invention to a person of ordinary skill is hardly clear and is, in effect, a legal fiction designed to approximate objectivity. As illustrated by Chief Justice John Roberts of the Supreme Court in a moment of levity, “Who do you get to ... tell you something’s not obvious … the least insightful person you can find?” [2] Despite the apparent objectivity provided by a “person of ordinary skill” obviousness standard, the difficulty lies in that such a standard is still susceptible to multiple interpretations, depending on the point of view and knowledge ascribed to the “ordinary person.” As such, how obviousness is defined and interpreted by the courts will have important implications on biotechnology patents and the biotechnology business.The issue of obviousness arose in April 2007 when the Supreme Court handed down its decision in KSR Int’l Co. v. Teleflex, Inc. [3] The facts of the case were anything but glamorous; in the suit, Teleflex, a manufacturer of adjustable pedal systems for automobiles, sued KSR, its rival, for infringement of its patent, which “describe[d] a mechanism for combining an electronic sensor with an adjustable automobile pedal so that the pedal’s position can be transmitted to a computer that controls the throttle in the vehicle’s engine.” [4] Teleflex believed that KSR’s new pedal design was too similar to its own patented design and therefore infringed upon it [5]. In defense, KSR argued that Teleflex’s patent was merely the obvious combination of two pre-existing elements and, thus, the patent, upon which Teleflex’s infringement claim was based, was invalid.Patent law relies on the concept of obviousness to distinguish whether new inventions are worthy of being protected by a patent. If a new invention is too obvious, it is not granted a patent and is therefore not a legally protected property interest. However, if an invention is deemed not obvious and has met the other patentability requirements, a patent will be granted, thereby conferring exclusive use of the invention to the patent holder. This exclusive right prohibits others from making, using, selling, offering to sell, or importing into the United States the patented invention [6]. Essentially, the definition of obviousness sets the balance between rewarding new inventions with exclusive property rights and respecting old inventions by not treating minor variations of existing patents as new patents. In this manner, the law seeks to provide economic incentives for the creation of new inventions by ensuring that the property right conferred by the patent will be protected against insignificant variations. The importance of where the line for obviousness is drawn and how clearly it is drawn is especially important in the biotechnology industry. Studies have shown that the development of a new pharmaceutical therapy can take up to 14 years with costs exceeding $800 million [7]. Such an enormous investment of time and money would not be practical if it did not predictably result in a legally enforceable property right.The standard for what constitutes a patentable discovery has evolved over the last 150 years. In 1851, the Supreme Court held in Hotchkiss v. Greenwood that a patentable discovery required a level of ingenuity above that possessed by an ordinary person [8]. Lower courts treated the Hotchkiss standard as a subjective standard, whereby courts sought to determine “what constitute[d] an invention” [9] and a “flash of creative genius” [10]. However, the attempts at imposing the Hotchkiss standard proved unworkable, and in 1952, Congress overrode the case law with the Patent Act, “mandat[ing] that patentability be governed by an objective nonobviousness standard.” [11] This new statutory standard moved the courts away from subjective determinations and toward a more workable, objective obviousness standard.While the Patent Act laid the foundation for the current obviousness standard, the Supreme Court in Graham v. John Deere Co. interpreted the statutory language in an attempt to provide greater clarity as to what exactly “obvious” meant [12]. The Supreme Court determined that the objective analysis would require “the scope and content of the prior art ... to be determined; differences between the prior art and the claims at issue ... to be ascertained; and the level of ordinary skill in the pertinent art resolved.” [13] In addition to analysis under this three-part framework, the Supreme Court called for several secondary considerations to be weighed, including “commercial success, long felt but unresolved needs, [and the] failure of others [to solve the problem addressed].” [13]Unsurprisingly, lower courts were unsatisfied with the Supreme Court’s attempts to clarify the obviousness standard and sought to provide “more uniformity and consistency” to their evaluation of obviousness than the Supreme Court’s jumble of factors provided [14]. In search of consistency, the Federal Circuit created the “teaching, suggestion, or motivation” test (TSM test) “under which a patent is only proved obvious if ‘some motivation or suggestion to combine prior art teachings’ can be found in the prior art, the nature of the problem, or the knowledge of a person having ordinary skill in the art.” [14] Through implementation of the TSM test, the Federal Circuit sought to maintain the flexibility envisioned by the Supreme Court in Graham, while at the same time providing more certainty and predictability to obviousness determinations.The issue before the Supreme Court in KSR Int’l Co. v. Teleflex, Inc. was whether the Federal Circuit’s elaboration on the statutory language of the Patent Act, the TSM test, was consistent with the terms of the Patent Act itself and the Supreme Court’s own analysis in Graham. The Supreme Court determined that while the TSM test was, on its terms, consistent with the framework set out in Graham, the rigid manner in which the Federal Circuit had taken to applying that standard was inconsistent with the flexible approach established by Graham [15]. More generally, it appears the Supreme Court was mainly interested in restoring a more rounded, thorough inquiry to the evaluation of obviousness: “Graham set forth a broad inquiry and invited courts, where appropriate, to look at any secondary considerations that would prove instructive.” [16] As stated by the Supreme Court, “[r]igid preventative rules that deny factfinders recourse to common sense, however, are neither necessary under our case law nor consistent with it.” [17] As such, the Supreme Court reversed the findings of the Federal Circuit, which had found the Teleflex patent valid, and remanded the case back to the lower court with directions to analyze, without rigid adherence to the TSM test, whether the Teleflex patent was obvious [18].The Supreme Court’s ruling in KSR Int’l Co. v. Teleflex, Inc. that the Federal Circuit apply its TSM test less rigidly may have implications for those seeking biotechnology patents in the future. As discussed above, the large investments necessary to develop a marketable biotechnology product demand that entrepreneurs making those investments be reasonably assured that they can predict any future legal hurdles in patenting their invention and in ultimately protecting their patent. As explained by the Biotechnology Industry Organization in its amicus curiae brief in KSR Int’l Co. v. Teleflex, Inc., “[i]nvestment thus is predicated on an expected return on investment in the form of products or services that are protected by patents whose validity can be fairly determined.” [19] Therefore, the Supreme Court’s insistence that the Federal Circuit no longer rigidly rely on the TSM test could increase uncertainty in the grant of future patents. However, the Supreme Court’s refusal to completely dismiss the TSM test, while in fact endorsing its continued use, albeit on a less rigid basis, has to be viewed as a profound victory for an industry with a significant stake in maintaining the status quo. Moreover, it is unclear how much the Supreme Court’s holding in KSR Int’l Co. v. Teleflex, Inc. will truly change the legal analysis of the lower courts, given the evidence that lower courts already were independently shifting away from rigid adherence to the TSM test before the Supreme Court’s ruling [20].More importantly, several aspects of the Supreme Court’s reasoning in KSR Int’l Co. v. Teleflex, Inc. seem to directly address relevant concerns of the biotechnology market in favorable ways. First, the Supreme Court made clear that though a product is the result of a combination of elements that were “obvious to try,” it is not necessarily “obvious” under the Patent Act. Retaining the possibility that “obvious to try” inventions still may be patentable is extremely important to the biotechnology industry in particular because “many patentable inventions in biotechnology spring from known components and methodologies found in [the] prior art.” [21] Rather than foreclosing all “obvious to try” inventions as being obvious, and therefore not patentable, the Supreme Court instead explained that where there is “a design need or market pressure to solve a problem and there are a finite number of identified, predictable solutions,” it is more likely that a person of ordinary skill would find it obvious to pursue “known options.” [22] Thus, the proper inquiry, as stated by the Supreme Court, is “whether the improvement is more than the predictable use of prior art elements according to their established functions.” [23] While this reasoning may prevent some “obvious to try” inventions from being patented, it is unlikely to have a substantial effect on inventions in the biotechnology market because “most advances in biotechnology are only won through great effort and expense, and with only a low probability of success in achieving the claimed invention at the outset.” [24] In other words, it would be hard to characterize the use of prior art in the biotechnology context as predictable based on the inherent unpredictability of obtaining favorable results. As such, most biotechnology inventions would presumably fall outside the Supreme Court’s “obvious to try” reasoning due to the very nature of the industry, meaning they would remain patentable under the Supreme Court’s KSR Int’l Co. v. Teleflex, Inc. decision.Second, the Supreme Court recognized the “distortion caused by hindsight bias” and the importance of avoiding “arguments reliant upon ex post reasoning,” though it lessened the Federal Circuit’s rigid protection against hindsight bias [24]. Hindsight bias requires that obviousness be viewed at the time the invention was made, because what may seem revolutionary at the time of invention may, upon the passage of time, seem “obvious.” Cognizance of hindsight bias is crucial for biotechnology patents because “there often is a long ‘passage of time between patent application filing and litigation with biotechnology inventions [that] can exacerbate the problem’ of hindsight bias.” [25] The problem is further exacerbated by the “significantly longer durations of commercial utility” biotechnology inventions enjoy as compared to those in other fields [25]. The more time between the filing of a patent and the subsequent litigation over its validity, the greater the risk that “reliable accounts of [the] context” in which the discovery is made will no longer exist [26]. As such, inventions that were not obvious when they were created will be inescapably colored by the passage of time and by new knowledge and discoveries; the likelihood of this occurrence is higher the further removed the litigation is from the patent filing date. Once again, however, it seems clear that despite the Supreme Court’s abandonment of the TSM test’s rigidity, strong protections against hindsight bias still were emphasized in the Supreme Court’s KSR Int’l Co. v. Teleflex, Inc. decision. In fact, lower courts applying KSR Int’l Co. v. Teleflex, Inc. acknowledge they are “cautious” to avoid “using hindsight” in biotechnology obviousness determinations [27].Finally, the Supreme Court seems to believe that the imposition of a more flexible approach will be more likely to benefit markets not directly at issue in KSR Int’l Co. v. Teleflex, Inc. The Supreme Court asserted, “[t]he diversity of inventive pursuits and of modern technology counsels against limiting the analysis” to the rigid TSM test of the Federal Circuit [28]. This language suggests that the Supreme Court expects lower courts to take into consideration the special considerations facing unique markets, such as the biotechnology market. As such, the specific concerns of the biotechnology market discussed above may receive more attention under the flexible framework asserted by the Supreme Court in KSR Int’l Co. v. Teleflex, Inc.Leading up to the oral argument in KSR Int’l Co. v. Teleflex, Inc., there was widespread speculation that the case could result in a watershed moment, significantly altering the definition of obviousness in patent law. For many, including those in the biotechnology industry, there was ample reason to be concerned. Any change in the definition of obviousness would effectively shift property rights from new patent holders to old, or vice versa. However, the Supreme Court acted with restraint. While the decision purports to make substantial changes by doing away with the Federal Circuit’s TSM test, the opinion seems more like a mild-mannered rebuke of lower courts that had become too complacent in the implementation of their beloved test. If anything, the Supreme Court’s insistence on a more flexible formula is simply a call for lower courts to employ common sense, in addition to considering the factors from Graham and the TSM test. Accordingly, the Supreme Court’s opinion in KSR Int’l Co. v. Teleflex, Inc. is unlikely to have a pronounced effect on the biotechnology market, despite the widespread concern generated before the actual decision was handed down.  相似文献   

11.
12.
Despite our advanced understanding of primary cancer development and progression, metastasis and the systemic spread of the disease to secondary sites remains the leading cause of cancer-associated death. The metastatic process is therefore a major potential therapeutic target area for cancer researchers and elucidating the key steps that are susceptible to therapeutic intervention will be critical to improve our treatment strategies. Recent advances in intravital imaging are rapidly improving our insight into this process and are helping in the design of stage-specific drug regimes for the treatment of metastatic cancer. Here we discuss current developments in intravital imaging and our recent use of photobleaching and photoactivation in the analysis of dynamic biomarkers in living animals to assess the efficacy of therapeutic intervention on early stages of tumor cell metastasis.Key words: in vivo imaging, photobleaching, photoactivation, biomarkersMetastasis is a complex process consisting of interactions between cancer cells and their surrounding extra-cellular matrix and stroma. To give rise to a secondary tumor, a primary tumor cell undergoes alterations to its cell-cell and cell-ECM contacts, allowing it to breach the basement membrane and intravasate into the vasculature or the lymphatic system. A tumor cell must survive in the circulation before extravasating at a secondary site and initiating new tumor growth and the development of its own blood supply. Imaging this process in live animals under native physiological conditions is inherently difficult due to poor sample stability, tissue penetration and autofluorescence of the tissue. However, new advances in fluorescent imaging, including the continued development of green fluorescent protein (GFP) and its variants, have facilitated the observation of this process and shed light on some key mechanisms that determine how and why cells metastasise. The use of fluorescent probes for in vivo imaging can be divided into two types (1) ‘passive’ markers or reporters used for direct visualization and tracking of cell movement in relation to extracellular structures and (2) more complex, ‘active’ reporters or biosensors for monitoring detailed processes such as biochemical activity or protein-protein interactions during metastasis.1,2 In some cases there can be overlap between both types of imaging which will be addressed here.The majority of early intravital imaging studies focused on the stages of metastasis that occur after dissemination from the primary tumor and predominantly used a ‘passive’ reporter approach to assess tumor cell behavior. Models of circulating tumor cells have allowed for analysis at the single cell level of tumor cell velocity, persistence, shape change and interactions with the ECM and stroma in secondary tissue.35 The use of fluorescently-labelled cells has also revealed some limiting factors that cause the arrest of cancer cells in target tissue such as trapping in small capillary networks due to tumor cell size or adhesion to surrounding vessel walls.6,7 Furthermore, experimental models of metastasis such as intra-splenic, intra-cardial and tail vein injections in combination with fluorescently-tagged tumor cells has provided information on the colonisation, extravasation and dormancy of tumor cells in secondary sites (Fig. 1 and refs. 5, 8 and 9). Collectively, along with the rapid increase in tissue specific expression of GFP in mouse cancer models,10 a wealth of information on different steps of the metastatic process has begun to emerge.Open in a separate windowFigure 1(A) Whole body optical imaging of mCherry-expressing SW 620 colon cancer cell metastases after approximately six weeks post intra-splenic injection. Images were obtained using the Olympus OV100 whole body imaging system with an Olympus MT10, 150 w, Xenon light source, using a low magnification objective (macro lens) with a magnification of 0.14× and numerical aperture of 0.04. (B) mCherry expressing SW 620 colon cancer cells colonizing the liver 30 mins after intra-splenic injection. 1 × 106 cells were injected into the spleen of an anesthetised CD-1 nude mouse and the incision sealed using ‘Clay Adams’ vetinary clips (VetTec). The mouse was placed on a heat pad for 30 mins then sacrificed. An incision was made in the abdomen to expose the liver and images of fluorescent cells within the liver were obtained using a 0.8× (0.22 NA) objective lens with variable zoom on the Olympus OV100.The departure of individual cells away from solid primary tumors into the blood stream has been a more difficult process to study using intravital imaging. It is a rare, sporadic event, requiring long acquisition and the inherent density and complex nature of the tumor tissue poses problems for imaging. Overcoming autofluorescence and light scattering has recently been improved due to advances in fluorophores1,11 and the combined use of long-term multiphoton microscopy12 has allowed greater resolution and tissue penetration than before. Multiphoton imaging can also provide additional detail regarding the interaction between cells and the surrounding extracellular environment using second harmonic signal generation (SHG) from collagen, elastin and other matrix proteins found in connective tissue.13,14 In this regard, imaging the interaction of cancer cells with extracellular matrix has revealed distinct modes of cell locomotion adopted by cancer cells in vivo, such as ameboid or mesenchymal invasion, that depend upon the topography or density of the surrounding matrix.3,13,15 A greater understanding of the initial cell movement and interaction with the extracellular environment will enhance our ability to pin-point cell-ECM targets that may be of clinical relevance in the future.Concurrent with the use of GFP as a ‘passive’ marker, a number of techniques have been developed that facilitate the visualization and localisation of GFP-tagged fusion proteins to quantify changes in protein expression, mobility and sub-cellular interactions during various processes in vitro. These include photobleaching (PB), photoactivation (PA), fluorescence resonance energy transfer (FRET) and fluorescent life time imaging microscopy (FLIM).2,16,17 The adaptation of these techniques for in vivo imaging to examine the activity of key molecules will provide new ‘active’ markers or reporters that can be correlated with biological processes important in disease progression such as migration, proliferation and cell death. Other fluorescent probes such as MMPsense or Apotrace that measure ‘active’ processes such as metalloproteinase activity or apoptosis have also recently been used in animals.18,19 In this way we can get closer to understanding how subcellular components or signal transduction pathways interact in real-time. The improved spatial and temporal detail will facilitate the ‘when and where’ we should target metastatic cancer cells for therapy.12In our recent paper we have adapted two techniques, photobleaching and photoactivation, for in vivo imaging and used them to assess the potential of E-cadherin as a molecular biosensor for cell migration in live tumors.20 E-cadherin-based cell-cell contacts are prominent sites of remodelling during early stages of epithelial to mesenchymal transition (EMT). The disruption or deregulation of E-cadherin-based adhesions leads to the collapse of normal epithelial architecture that precedes the initial intravasation of cells from tumors.2123 In vitro photobleaching analysis of E-cadherin can be used as an ‘active’ molecular read-out of cell migration, as cells within a stationary colony show significantly reduced E-cadherin mobility compared to collectively migrating cells.20 Moreover, as demonstrated in Figure 2 (reviewed in ref. 20), E-cadherin mobility can also be spatially regulated within a population of tumor cells, as cells at the rear of a wound show impaired E-cadherin mobilisation compared to cells at the leading edge of the wound. This suggests a gradient of E-cadherin mobilisation within the local environment of a tumor may exist and could potentially be used in the future to map areas of weakened cell-cell adhesion from which cells are more likely to migrate. In vivo analysis of E-cadherin dynamics showed that changes in the mobility of E-cadherin can also be used as an ‘active’ marker of cell behavior in live animals, and may be useful in predicting cell mobilisation from primary tumors.20Open in a separate windowFigure 2FRAP of GFP-E-cadherin at the rear or front of a wound heal assay. (A and B) Schematic and representative images of a wound heal assay depicting the area of cells selected for E-cadherin-based cell-cell junction FRAP analysis (red broken line). (C and D) Representative images of FRAP experiments performed at the rear or front of a wound heal assay respectively. White solid arrows represent area of photobleaching at the rear and white broken arrows represent area of photobleaching at the front of the wound. Red arrows indicate dynamics of cells at the front of the wound. Cells were classed to be at the front of the wound within the first three cells from the wound border (reviewed in ref. 20).We also demonstrated the subcellular tracking of plasma membrane dynamics in vivo using the membrane-targeting sequence of H-Ras fused to photoactivatable-GFP.24,25 Importantly, both the dynamics of cell-cell junctions, as visualised using E-cadherin:GFP, and the dynamics of the plasma membrane, which also plays a fundamental role in cell invasion and metastasis, are significantly different in vivo than in vitro.20 Critically, this raises the possibility that many signalling axes and networks may function differently in vivo and therefore care must be taken when correlating in vitro information to the live setting. Lastly, we demonstrated the benefits of in vivo imaging in the assessment of molecular-based targeted therapeutics by using the Src inhibitor dasatinib, which impaired E-cadherin cell mobility in vivo but not in vitro.20,26In the context of previous intravital imaging studies, our work suggests that we are at the beginning of a new stage of intravital imaging in which ‘active’ probes can help predict the efficacy of novel therapeutic treatments and also provide a context dependent read-out of oncogene-induced biological behavior in live animals. Importantly, not all molecules are adaptable for this type of in vivo imaging. Careful selection of candidate molecular markers that demonstrate clear changes attributable to a biological function, for example, subcellular relocalization or compartmentalisation, will be ideally suited for this type of intravital examination in the future.Here we have adopted two key fluorescent imaging techniques typically used in vitro and combined them with a fundamental biological question in vivo. The adaptation of other techniques for in vivo imaging such as FRET or FLIM-FRET probes will provide a detailed pixel by pixel map of the activity and behavior of key signalling proteins in live animals.2,27 The use of these ‘active’ probes in vivo may hold further surprises concerning differences in molecular behavior in live animals compared to the traditional ‘snap-shot’ approach in vitro. Finally, one of the major challenges of in vivo imaging during drug discovery is the need for repeated imaging of the same animal in the presence or absence of drugs. The continued development of optical windows and observation chambers for non-invasive real-time imaging will facilitate this and allow for the assessment of drug response at the single cell level.28 This, when combined with the subcellular optical techniques described here, will prove very useful in the future for in vivo imaging when evaluating the aetiology of the disease or during the drug discovery process.  相似文献   

13.
Charles Darwin recognized the power of the root cap as a model for plant signalling and behavior, and used it to explore the ways plants sense and respond to diverse stimuli. Over ensuing decades, various groups have reported tantalizing clues regarding the role of a complex extracellular matrix that ensheaths the tip region housing the apical and root cap meristems. In the course of characterizing root tip resistance to infection and injury and the role border cells play in this phenomenon, we confirmed and extended early- and mid-20th century studies reporting enzyme activities secreted from the root cap. Multidimensional protein analysis revealed, in fact, that >100 proteins are actively synthesized and secreted from the root cap and border cells. This ‘root cap secretome’ appears to be a critical component of root tip resistance to infection. We have developed a microscopic assay to quantify the protein-based extracellular response to dynamic changes in environmental conditions including hydroponic culture, and present the results here. This tool provides a simple, direct measure that can be used to explore the ways border cells may function in the manner of white blood cells to trap, immobilize and neutralize threats to the growing root tip.Key Words: roots, roots cap, rhizosphere ecology, border cells, extracellular proteins, secretomeIn a process similar to the shedding of ‘buccal’ cells into the mammalian oral cavity, root caps of most higher plants naturally can shed thousands of healthy ‘border’ cells into the external environment each day.4,5 Like buccal cells ensheathed in saliva, populations of border cells are contained within a mucous-like material.1,2,6,7 This material-historically termed root cap ‘slime’ or ‘mucilage’-has been found by several groups to be comprised of a high molecular weight polysaccharide, with a small amount of protein (95% and 5%, respectively).1,810 Previously, we used two-dimensional electrophoresis to characterize root cap and border cell proteins in pea and were surprised to find that within a 1 h period of exposure to 35S-labelled methionine, >100 proteins are synthesized and exported into the extracellular environment.11 The protein activities within this ‘root cap secretome’ appear to be critical to the capacity of the root cap extracellular material to protect the root tip from infection.12 When these proteins are degraded the mucilage disintegrates, as described below, suggesting for the first time that the minority protein component of the root cap slime layer is a key structural component.In summary, multidimensional protein analysis confirmed that the root cap secretome includes a mixture of ∼120 proteins including defense and signalling enzymes as well as structural proteins like actin.12 When the proteins are solubilized in situ using a broad spectrum protease, the root tip of pea completely loses its resistance to infection by the pea pathogen, Nectria haematococca. Normally, only 3% of inoculated roots of a susceptible host develop a lesion at the root tip even under conditions highly conducive to infection.13 After protease treatment, however, frequency of infection was increased to 100%.12 Every inoculated root tip became necrotic. This surprising result reveals that, despite being a minor physical component of the extracellular matrix, the secretome is a major functional component.India ink can be used to visualize bacterial and fungal cells, whose extracellular capsules exclude penetration of the carbon particles.14,15 Here we report that the contours of the entire slime-mucilage ‘blob’ (Fig. 1), with border cells embedded within the matrix (Fig. 1, arrows) can be visualized using this simple assay. Surprisingly, the same protease treatment used to solubilize the secretome and eliminate root tip resistance to infection12 also eliminates the matrix seen with India ink. These data indicate that protein is a key structural as well as functional component of the matrix, such that solubilizing the 5% of the matrix that is protein causes the entire structure to disintegrate.Open in a separate windowFigure 1India ink assay to visualize root cap ‘mucilage’. A root tip (white arrow) was placed onto a glass slide and India ink was added. After addition of a cover slip, a clear delineation can be seen (white triangles) where ink fails to penetrate due to the presence of an impermeable layer. Border cells (black arrows) are present throughout the boundary layer. Addition of proteinase K, under conditions that destroy root tip resistance to infection, destroyed the boundary layer, resulting in an unbroken field of black when ink is added (not shown). Magnification: bar = 1 mm.As previously shown in a study of genotype-specific responses of Phaseolus vulgarus border cells to aluminum,16 the India ink assay revealed that individual border cells exhibit species-specific dynamic responses to microbial challenge (Fig. 2). Control pea border cells, washed to remove soluble material, are surrounded by a ca 5 µm wide capsule around the cell periphery (Fig. 2A). When incubated with N. haematococca conidia, a marked increase in the size of the capsule occurred (Fig. 2B). In contrast, when incubated with proteinase K, the capsule virtually disappeared (Fig. 2C). Control corn border cell capsules are slightly larger than those of pea (Fig. 2D). After cocultivation with Pseudomonas aeruginosa, the capsule increased by several-fold and bacterial cells could be seen enmeshed within the layer (Fig. 2E, arrows). Remarkably, a dramatic, >50-fold increase in capsule size occurred on border cells of corn cocultivated in hydroponic culture for 7–10 days with a gram-positive bacterium (Bacillus sp) found as a seed-borne epiphyte (Fig. 2F).Open in a separate windowFigure 2Dynamics of border cell capsule induction, and solubilization by proteinase K. India ink was used to visualize the boundary (triangles) of (A–C) pea and corn (D–F) border cell capsules. (A) Control pea border cell capsule; (B) Increased capsule size in response to N. haematococca conidia; (C) Effect of protease treatment on the the border cell capsule. The cell remains viable, as can been seen by the intact nucleus (arrow), but the capsule is nearly eliminated. (D) Control corn border cell; (E) Increased capsule occurring in response to cocultivation with Pseudomonas aeruginosa. Trapped bacteria can be seen within the capsule (arrows); (F) Massive capsule around a single corn border cell after hydroponic culture for >1 week. Magnification: bar = 15 µm.Brinkmann et al.17 reported that, in mammalian systems, white blood cells (neutrophils) produce extracellular structures containing antimicrobial proteins. According to the authors, these neutrophil extracellular traps (NETs) ‘appear to be a form of innate response that binds microorganisms, prevents them from spreading, and ensures a high local concentration of antimicrobial agents to degrade virulence factors and kill bacteria.’ The trapping of pathogenic bacteria within the border cell capsule was reported previously.18 Knudson19 reported that border cells of pea and corn survive for months in hydroponic culture, and the potential impact of such massive capsules on microbial survival over time will be of interest. Our results support the premise, as others have suggested, that the root cap extracellular matrix is a dynamic conduit for plant signalling and behavior responses.20,21 Recognition of the critical role the extracellular proteome plays in its function will provide a context to dissect how root caps perceive and respond to incoming signals to control root growth and development.A note on terminology: Perhaps it might be time to consider that a more dignified term than root cap ‘slime’ would more accurately represent this dynamic component of plant root systems. If the extracellular matrix functions, as in neutrophils, to kill bound bacteria and fungi, then border cell extracellular trap (BET) might work. Border cell ‘capsule,’ in the meantime, accurately conveys the concept of a functional unit surrounding individual cells, and highlights the likely functional parallels with microbial cells.14,15 The capsule of Bacillus anthracis cells, for example, also includes integral proteins—the ‘S-layer’—which underlie surface receptors that control pathogen-host recognition.14 However, root cap capsule seems a bit redundant. We would be interested in the views of our colleagues: Stick with slime? Suggestions for an alternative name?  相似文献   

14.
Somastostatin receptors are frequently expressed in phaeochromocytoma but data on somatostatin receptor subtyping are scanty and the functional response to the somatostatin analogue octretide is still debated.We report an unusual case of pheochromocytoma, causing ectopic Cushing’s syndrome due to CRH production by the tumour cells, in a 50-yr-old woman. Abdominal computed tomography revealed an inhomogeneous, 9-cm mass in the right adrenal gland, and [111In-DTPA0] octreotide scintigraphy showed an abnormal uptake of the radiotracer in the right perirenal region, corresponding to the adrenal mass. The patient underwent laparoscopic surgery and formalin-fixed and paraffin-embedded samples were studied. The tumour was extensively characterized by immunohistochemistry and somatostatin receptor (SSTRs) subtypes expression was analyzed. Histological and immunohistochemical examination of the surgical specimens displayed a typical pheochromocytoma, which was found to be immunoreative to S-100, chromogranin A and neurofilaments. Immunostaining for SSTR subtypes showed a positive reaction for SSTR1, SSTR2A, SSTR2B, antisera on tumour cells. The intense and diffuse immunostaining for corticotropin releasing hormone (CRH) antiserum indicated that Cushing’s disease was dependent on CRH overproduction by the pheochromocytoma, in which no immunostaining for adrenocorticotropic hormone was found. Our report confirms the heterogeneity of the pattern of SSTR expression in pheochromocytomas, and provide further evidence for functional SSTR subtype SSTR2a in a subgroup of pheochromocytomas, suggesting that these tumours may represent potential target for octreotide treatment.Key words: phaeochromocytoma, neuroendocrine tumours, somatostatin receptors, octreotide, corticotropin releasing hormone.Phaeochromocytomas are tumours derived from the chromaffin cells of the sympathoadrenal system, generally associated with cathecolamine overproduction. They represent a rare condition, occurring in less than 0.2% of patients with hypertension. The diagnosis of sporadic phaeochromocytoma is based on clinical history and features characterized by the triad episodic headache, sweating, and tachycardia, but an increasing number of these tumours are diagnosed in patients without classical symptoms (Pacak et al., 2001). Ectopic Cushing’s syndrome is one of the possible, albeit unusual, expression of pheochromocytoma. Up to date, there are few reports of pheochromocytomas producing adrenocorticotropic hormone (ACTH) and/or ACTH precursors (O’Brien T et al., 1992; Chen et al., 1995; White et al., 2000), and even more limited is the number of cases in which pheochromocytoma secrete corticotropin releasing hormone (CRH) (Eng et al., 1999; Bayraktar et al., 2006).Similar to other neuroendocrine tumours, pheochromocytomas often express somatostatin receptors (SSTR) (De Herder and Hofland, 2004), but data on the specific SSTRs subtypes expressed within the tumours are thus far sparse and conflicting and the real therapeutic effectiveness of somatostatin analogue in these tumours is still debated (Reubi et al., 1992; Kubota et al., 1994; Epelbaum et al., 1995; Hofland et al., 1999; Mundschenk et al., 2003; Unger et al., 2004; Ueberberg et al., 2005; Unger et al., 2007).  相似文献   

15.
The role of medical anthropology in tackling the problems and challenges at the intersections of public health, medicine, and technology was addressed during the 2009 Society for Medical Anthropology Conference at Yale University in an interdisciplinary panel session entitled Training, Communication, and Competence: The Making of Health Care Professionals.The discipline of medical anthropology is not very formalized in the health setting. Although medical anthropologists work across a number of health organizations, including schools of public health, at the Centers for Disease Control (CDC), and at non-governmental organizations (NGOs), there is an emerging demand for an influential applied medical anthropology that contributes both pragmatically and theoretically to the health care field.The role of anthropology at the intersections of public health, medicine, and technology was addressed during the 2009 Society for Medical Anthropology Conference at Yale University in September. In a conference session entitled Training, Communication, and Competence: The Making of Health Care Professionals, health professional career issues, including training and education, medical entrepreneurship, and the maintenance of clinical relationships with patients were examined. The presentations encompassed macro approaches to institutional reform in training, education, and health care delivery, as well as micro studies of practitioner-patient interaction. Seemingly disparate methodological, disciplinary, and theoretical orientations were united to assess the increasing relevance of medically oriented anthropology in addressing the challenges of health care delivery, health education, and training.Margaret Bentley, a professor of public health at the University of North Carolina, Chapel Hill, spoke about the increasing “epidemic of global health” in universities, noting a doubling of global health majors within the past three years. Despite this expansion of the field, a common discipline of global health continues to be developed. In September, the Association of Schools of Public Health (ASPH) and the University of Minnesota hosted a Global Health Core Competency Development Consensus Conference with the initiative to explore “workforce needs, practice settings, and to identify core constructs, competency domains, and a preliminary global health competency model”1. Given the current variability in training, Bentley believes medical anthropology is uniquely suited to inform training in global health because of its offerings in the way of interdisciplinary methods and team-based applied field experience.Anthropologists Carl Kendall of Tulane University and Laetitia Atlani of Université de Paris X Nanterre have seen medical anthropologists examine models of health strictly within a clinical experience. Understanding of the social determinants of epidemiology, methodological issues of population health, and survey research is crucial. However, training individuals through a more formalized program (currently in development in Europe) will allow anthropologists to better understand context, explain complex models, humanize aggregate statistics, and articulate methods of the multidimensional “social field” of health outside of the clinical experience.The social field of health, however, as Robert Like of the University of Medicine and Dentistry of New Jersey explained, shares an uncomfortable interface with clinical medicine. Recent efforts by the New Jersey Board of Examiners to incorporate cultural competency legislation have been robustly criticized. Evaluations of six-hour training sessions on cultural competency training have revealed health professionals’ frustration with the health care system’s inability to deal with “culturally different” individuals. In fact, the majority of health professionals who were required to complete the training believe cultural competency to be an area of study that is a “waste of time.”This opposition to cross-cultural education and the value of “cultural competence” training also has been a topic of great debate among anthropologists and health researchers. Despite the ubiquitous use of the term among research and health professionals, cultural competency is a term that cannot be defined precisely enough to operationalize.In “Anthropology in the Clinic: The Problem of Cultural Competency and How to Fix It,” Arthur Kleinman and Peter Benson asserted that the static notion of culture in the medical field “suggests that a culture can be reduced to a technical skill for which clinicians can be trained to develop expertise” [1]. T.S. Harvey, a linguistic and medical anthropologist at the University of California, Riverside, expounded on Kleinman’s opposition to competence as an acquired “technical skill” [1] and suggested reconceptualizing the approach to competence as communication. Although Kleinman’s explanatory models approach [2] provides a health care professional with what to ask the patient, Harvey pulls from Dell Hymes’ communicative competence [3] to understand how to ask it. Harvey recommended viewing competence as a “sociolinguistic acquisition … like a foreign language” where competencies are rule-governed and communication and speech events are formulaic.Harvey also noted that the “onus of cultural competency” is too often placed on the practitioner. Inevitably, there is an asymmetry in every clinical encounter, whereby the “would-be patient” is perpetually considered the “passive receptor.” Patients also share a stake in their health and, as such, should be taught communicative competence as well.Harvey also noted that the “onus of cultural competency” is too often placed on the practitioner. Inevitably, there is an asymmetry in every clinical encounter, whereby the “would-be patient” is perpetually considered the “passive receptor.” Patients also share a stake in their health and, as such, should be taught communicative competence as well.The role of the patient is made ever more complex by the power relationship that exists in the patient-provider context. Through ethnographic research, Sylvie Fainzang, director of research in the Inserm (Cermes), examines how doctors and patients lie. She argues that lying, in the context of secrecy, is an indication of a power relationship [4]. Fainzaing’s further research on the relationship between doctors and patients has yielded additional information on how patients learn about their diagnoses and how they will react to these diagnoses. Though a clinical encounter between a doctor and patient is expected to be one of informed consent, doctors often judge patients upon their ability to “intellectually understand” [4] and assess who is “psychologically ready” [4] to bear the information. This leads to manipulated, misinformed, and “resigned consent” [4]. This sort of social training of obligation of a subject to medical authority provides the patient with the choice either to conform or overthrow the rules as defined by society.Collectively, this interdisciplinary panel worked to inform the discussion on how medical anthropology can address training, communication, and competence at the intersections of medicine, public health, and education. By reviewing health professionals’ growing interest in public health, training in health education and competence, and the patient-provider relationship, medical anthropology can be seen as both relevant and necessary to addressing the challenges faced by the medical and health community today.  相似文献   

16.
Root elongation occurs by the generation of new cells from meristematic tissue within the apical 1–2 mm region of root tips. Therefore penetration of the soil environment is carried out by newly synthesized plant tissue, whose cells are inherently vulnerable to invasion by pathogens. This conundrum, on its face, would seem to reflect an intolerable risk to the successful establishment of root systems needed for plant life. Yet root tip regions housing the meristematic tissues repeatedly have been found to be free of microbial infection and colonization. Even when spore germination, chemotaxis, and/or growth of pathogens are stimulated by signals from the root tip, the underlying root tissue can escape invasion. Recent insights into the functions of root border cells, and the regulation of their production by transient exposure to external signals, may shed light on long-standing observations.Key words: border cells, chemotaxis, zoospores, neutrophil extracellular traps (NETs)The evidence suggests that there has evolved within plants, mechanisms for extremely rapid adjustment to changes in the soil environment. The logical conclusion is that plants can and do selectively manipulate the ecological balances within the rhizosphere to their own advantage.1“Sloughed root cap cells” that detach from the root tip were long presumed to be moribund tissue serving to lubricate passage of the elongating root.2 The discovery nearly a century ago that these cells from Zea mays L. and Pisum sativum L. can remain 100% viable for weeks after detachment into hydroponic culture did not alter this perception.3 In recent decades, studies have shown that the cells from root caps of most species are metabolically active and can survive even after detachment into the soil.4 Moreover, the cell populations express distinct patterns of gene expression reflecting tissue specialization and were therefore given the name root ‘border’ cells.5 Like ‘border towns’ that exist at the boundary of disparate countries and cultures, border cells are part of the plant and part of the soil, yet distinct from both.The soil is a dynamic environment whose pH, surface charge, water availability, texture and composition can range markedly on a large and small scale.1,6,7 The concept of a ‘microniche’ emphasizes that the biological requirements for a particular soil microorganism may be met within one site but not another site only a micron away.8 Thus, the rhizosphere—the region adjacent to root surfaces—can support much higher levels of microorganisms than bulk soil a few millimeters distant.9 This phenomenon is recognized to be driven by an increased availability of nutrients released from plants into the external environment.10 Less well recognized is the dynamic variation that occurs along the root surface, and its significance in patterns of disease development. As roots emerge and the new tissue differentiates progressively through stages from root cap, root apical meristem, elongation zone, and finally mature roots with lignified cell walls, the material released into the environment also changes.1113 More than 90% of bulk carbon released from young roots of legumes is delivered by the root cap, a 1 mm zone at the apex.14 Some pathogens are attracted specifically to the root tip region, presumably in response to such exudates.15,16 For example, instantaneous swarming occurs when a cotton root is placed into a suspension of Pythium dissotocum zoospores (Sup. Fig. 1). This host-specific attraction is specific to the root tip region where border cells are present (Sup. Fig. 2). Border cells remain attractive to zoospores when removed from the root (Sup. Fig. 3). The nature of the attractant is not known, but its impact is localized and transient (Sup. Fig. 4).Newly generated tissue is highly susceptible to infection by pathogens, in general, so elongating root tips would be predicted to be vulnerable to invasion. And yet, root apices repeatedly have been found to escape infection and colonization.1719 Recent discoveries about parallels between mammalian white blood cells and root border cells may provide new insight into this apparent conundrum.20 Neutrophils, a type of white blood cell, are produced in response to infection. Neutrophil extracellular traps (NETs) then attract and kill the invader through a process that requires extracellular DNA (exDNA) and an array of extracellular proteins.21,22 Border cell production, like that of neutrophils, also is induced in response to signals from pathogens and root tip resistance to infection requires exDNA and an array of extracellular proteins.20,23 Root tip specific chemotaxis, like that seen with Pythium zoospores, has been presumed to involve steps in a process of pathogen invasion.15,16 It may, instead, involve a process of extracellular trapping and killing by cells designed to protect root meristems from invasion, in a manner analogous to that which occurs in mammalian defense. If tests confirm this model, the mystery of how root tips escape infection by soilborne pathogens they attract could be resolved.  相似文献   

17.
Jenny M. Woof 《MABS-AUSTIN》2012,4(3):291-293
Fc receptors and their interaction with antibodies will be a major theme at the forthcoming FASEB Science Research Conference on Immunoreceptors to be held in Snowmass this July (details available at www.faseb.org/src/home.aspx, follow the tabs for Immunoreceptors). Since its inception in the mid 1980s, this meeting series has maintained a focus on Fc receptors, and this year’s meeting will be no exception.From a therapeutic viewpoint, there is much to be gained from a detailed understanding of the biology of effector molecules such as Fc receptors and complement. Indeed, knowledge of the interaction of IgG with such molecules has been central to the development of improved mAbs with altered functions and transformed half-lives, tailored for particular therapeutic applications. Examples include mAbs designed to maximise complement recruitment1 or to enhance Fc receptor engagement and triggering of ADCC,2-5 or conversely, variants engineered to be unable to engage complement6 or Fc receptors.7 Glycoengineering of IgG Fc offers an alternative means to modify effector function capabilities,8 while development of IgG mutants that display extended or altered serum half-lives has been driven through exhaustive analysis of the interaction with FcRn.9,10Despite the appreciable advances that have been made in unravelling the various facets of Fc receptor biology, new information pertinent to mAb engineering continues to emerge. A flavour of some of these new advances will be given below. They span novel receptors and receptor roles, structure-function relationships, the molecular architecture of signaling complexes, the influence of the membrane lipid environment and scaffolding interactions, isotype considerations, through to technical innovations likely to inform the field.Remarkably, new receptors that have previously eluded characterization are now being described. These include the IgM receptor, which evidence indicates is a molecule also known as TOPO/Fas apoptotic inhibitory molecule 3 whose gene lies close to other known immunoglobulin receptors on chromosome 1,11 and a receptor for IgD recently documented on basophils.12 Moreover, we are seeing an appreciation of new roles for existing Fc receptors. An example is the demonstration in a transgenic study that human FcγRIIa can trigger active and passive anaphylaxis and airway inflammation. Moreover, human mast cells, monocytes and neutrophils were shown to produce anaphylactogenic mediators when FcγRIIA was engaged.13 Hence IgG may contribute to allergic and anaphylactic reactions in humans by engaging FcγRIIa.Exciting new structural information on Fc receptors and their ligands is emerging. An important example is the solving of the X-ray crystal structure for human FcγRI.14 While the structural information supports a ligand binding mode similar to those of FcγRII or FcγRIII, the FG-loop in domain 2 of FcγRI with its conserved one-residue deletion appears critical for high affinity IgG binding. A second example concerns the high responder/low responder (HR/LR) polymorphisms of FcγRIIa, which are linked to susceptibility to infections, autoimmune diseases, and the efficacy of therapeutic Abs. New insights into these differences have been provided by the recent solving of the structure for the complex of the HR allele with IgG Fc.15 Third, understanding of the human IgE-FcεRI interaction has moved forward significantly through the solving of the X-ray crystal structure of the complex of FcεRI and the entire Fc region of IgE (comprising domains Cε2, Cε3 and Cε4).16 In a final example, the structural basis for the improved efficacy of nonfucosylated mAbs has been investigated.17 The X-ray crystal structure of the complex between nonfucosylated IgG Fc and a soluble form of FcγRIIIa carrying two N-linked glycans showed that one of two receptor glycans interacts with nonfucosylated Fc to stabilize the complex. It is proposed that when the Fc glycan is fucosylated this interaction is inhibited due to steric hindrance and, together with the negative effects of Fc fucosylation on the dynamics of the receptor binding site, this provides a rationale for the improved ADCC displayed by nonfucosylated IgG.A question of interest is precisely how Fc receptors bound to antibody ligands organize themselves within signaling complexes in the cell membrane. Some intriguing clues to this conundrum of molecular architecture are now surfacing. In mast cells, FcεRI molecules loaded with IgE form a synapse when presented with antigen that is mobile within a lipid bilayer, via coalescence into large cholesterol-rich clusters.18 Of particular relevance to the therapeutic setting, clustering of receptors into immune synapses is also seen with FcγR. For instance, during in vivo ADCC mediated by tumor-specific mAb, clustering of FcγR, actin and phosphotyrosines has been noted at contact zones between tumor cells and macrophages or neutrophils.19 The theme of the influence of the membrane lipid domain environment on Fc receptor function is taken up elsewhere. It has been shown, for example, that serine phosphorylation of FcγRI influences membrane mobility and function. The cytoplasmic tail of FcγRI interacts with protein 4.1G,20 and it is proposed that this is mediated via a phosphoserine-dependent mechanism critical for localization of the receptor to lipid rafts.21 With regard to FcγRIIa, a major role for lipid rafts in the regulation of IgG binding to FcγRIIa has been revealed.22 Notably, exclusion of FcγRIIa from lipid raft membrane microdomains is able to suppress IgG binding in myeloid cells.Increased knowledge of the capabilities of Fc receptors specific for other antibody classes is opening up new options for therapy. For example, IgA antibodies may offer a highly useful and efficacious alternative approach of particular relevance to treatment at mucosal sites. Human IgA mAbs have been demonstrated to mediate efficient tumor cell killing23,24 and to have the capability to control certain infectious diseases.25,26 The detailed understanding of functional sites in IgA that has resulted from numerous mutagenesis studies,27 coupled with improved ways to produce and isolate recombinant IgA mAbs28 should facilitate developments toward therapeutics based on this immunoglobulin class. Similarly, recent studies indicate that IgE may serve as an alternative to the classic IgG backbone for therapeutic antibodies.29Finally, technical innovations seem poised to further inform the field and advances are arriving or may be anticipated from techniques such as solution nuclear magnetic resonance (NMR) spectroscopy,30 cryo-electron tomography,31 single particle tracking,32 and ultrasensitive force techniques such as adhesion frequency assays.33,34Interest in Fc receptors continues unabated, and the contribution that the field can make to mAb development and optimisation is unquestionable. The FASEB SRC on Immunoreceptors will serve as a forum for discourse on the above issues and much more, providing invaluable information and networking opportunities for all those interested in ways to maximise the efficacy of mAbs and mAb-based reagents. Registration is open until 24 June 2012.  相似文献   

18.
The intimate arbuscular mycorrhiza (AM) association between roots and obligate symbiotic Glomeromycota (‘AM fungi’) ‘feeds’ about 80% of land plants. AM forming fungi supply land plants with inorganic nutrients and have an enormous impact on terrestrial ecosystems. In return, AM fungi obtain up to 20% of the plant-fixed CO2, putatively as monosaccharides. In a recent work we have reported the characterization of the first glomeromycotan monosaccharide transporter, GpMST1, and its gene sequence. We discuss that AM fungi might take up sugars deriving from plant cell-wall material. The GpMST1 sequence delivers valuable data for the isolation of orthologues from other AM fungi and may eventually lead to the understanding of C-flows in the AM.Key Words: arbuscular mycorrhiza, Geosiphon symbiosis, monosaccharide transporter, hexosesThe arbuscular mycorrhiza (AM) as an outstanding terrestrial plant symbiosis directly and indirectly is a driver of most terrestrial ecosystems. It is formed by ∼80% of land plants and by obligate symbiotic fungi of the phylum Glomeromycota.1 The glomeromycotan fungi usually are called ‘arbuscular mycorrhizal (AM) fungi’, or ‘AMF’, and obviously play an enormous ecological (and economical) role. Most land plants and glomeromycotan fungi are ‘joint systems’, forming the intimate AM.2 By this fact, statements like that of the BEG (European Bank of Glomeromycota) committee (1993): “The study of plants without their mycorrhizas is the study of artefacts; the majority of plants, strictly speaking, do not have roots—they have mycorrhizas” were provoked. AM fungi supply the vast majority of land plants with inorganic nutrients, mainly phosphorous, but also nitrogen, trace elements, and water. In return, they obtain up to >20% of the photosynthetically fixed CO2 as carbohydrates from the plants.3 It was calculated that, each year, 5 billion tons of carbon are transferred from plants to fungi (and therefore partly get deposited in the soil) via the AM symbiosis. AM fungi therefore represent a large sink for atmospheric CO2 on our planet and play a role in C-deposition in the soil.  相似文献   

19.
BackgroundIn the interest of cost effectiveness, switching antiretroviral brand name medications to generics is recommended in France since 2013. The study objective was to evaluate the perception of generics per se and antiretroviral generics in HIV-infected patients and their hospital physiciansConclusionsAcceptability of antiretroviral generics in this French population was mostly dictated by the patient’s and physician’s knowledge and use of generics overall. It should be improved with an efficient information of both patients and physicians.  相似文献   

20.

Background

Biologics are used for the treatment of inflammatory bowel diseases, Crohn´s disease and ulcerative colitis refractory to conventional treatment. In order to allocate healthcare spending efficiently, costly biologics for inflammatory bowel diseases are an important target for cost-effectiveness analyses. The aim of this study was to systemically review all published literature on the cost-effectiveness of biologics for inflammatory bowel diseases and to evaluate the methodological quality of cost-effectiveness analyses.

Methods

A literature search was performed using Medline (Ovid), Cochrane Library, and SCOPUS. All cost-utility analyses comparing biologics with conventional medical treatment, another biologic treatment, placebo, or surgery for the treatment of inflammatory bowel diseases in adults were included in this review. All costs were converted to the 2014 euro. The methodological quality of the included studies was assessed by Drummond’s, Philips’, and the Consolidated Health Economic Evaluation Reporting Standards checklist.

Results

Altogether, 25 studies were included in the review. Among the patients refractory to conventional medical treatment, the incremental cost-effectiveness ratio ranged from dominance to 549,335 €/Quality-Adjusted Life Year compared to the incremental cost-effectiveness ratio associated with conventional medical treatment. When comparing biologics with another biologic treatment, the incremental cost-effectiveness ratio ranged from dominance to 24,012,483 €/Quality-Adjusted Life Year. A study including both direct and indirect costs produced more favorable incremental cost-effectiveness ratios than those produced by studies including only direct costs.

Conclusions

With a threshold of 35,000 €/Quality-Adjusted Life Year, biologics seem to be cost-effective for the induction treatment of active and severe inflammatory bowel disease. Between biologics, the cost-effectiveness remains unclear.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号