药用植物细胞生物反应器技术的研究进展

利用植物细胞生物反应器技术生产植物有用代谢产物,近些年来取得了很大发展,但植物细胞悬浮培养的工业化应用仍受到来自生物及工程技术上的限制。针对植物细胞生物反应器技术的特点及其研究进展,提出在综合考虑生物学和工艺学两方面的基础上,选育药用植物稳定高产的优良细胞系是提高植物细胞生物反应器技术可行性的关键。     

In Defense of the Obstetrician and Obstetrics

Changes and advances in obstetrics are emphasized by the comparative study of private and one hospital practice in 1939 and 1964. Education, prenatal care, anesthesia, antibiotics, transfusions have all been instrumental. Old problems—abortion, toxemia, prematurity, developmental abnormalities—remain with us. New developments, both professional and economic, some not desirable, face us and demand that active practicing obstetricians take an active role in helping direct their course.     

植物细胞生物反应器培养的研究进展(I)

利用植物细胞大规模悬浮培养生产植物有用代谢产物在近些年来取得了很大发展,但植物细胞悬浮培养的工业化应用受到来自生物及工程技术上的限制。本文针对植物细胞培养的基本特点,详细讨论了与大规模生产有关的工程技术方面的问题,如植物细胞聚集、溶氧及气体成分、流体性能、剪切力对植物细胞培养产生的影响。     

植物细胞生物反应器培养的研究进展(I)

利用植物细胞大规模悬浮培养生产植物有用代谢产物在近些年来取得了很大发展,但植物细胞悬浮培养的工业化应用受到来自生物及工程技术上的限制.本文针对植物细胞培养的基本特点,详细讨论了与大规模生产有关的工程技术方面的问题,如植物细胞聚集、溶氧及气体成分、流体性能、剪切力对植物细胞培养产生的影响.     

Use of CR in the detection of present gastric cancer: diagnostic aspects

The authors describe the state-of-the-art of gastric cancer detection in detail and show the current principles of its radiodiagnosis. They provide a detailed explanation for that radiodiagnosis should be urgently returned into gastroenterology as an equal with endoscopy, which is based on the existing tendency for the major morphological types of gastric cancer to appear. The present-day capacities of radiodiagnosis of gastric cancer are mainly based on the introduction of the digital technologies into traditional radiology, which will replace the analog imaging principle in the foreseeable future. The authors present their data of examining 300 gastric cancer cases diagnosed by the CR system and later verified by a morphological study of resected gastric specimens. They emphasize that intraparietally growing gastric cancer is frequently inaccessible for endoscopy long, which determines the need for two basic procedures (radiodiagnosis and endoscopy) coexisting on a par for the detection of gastric cancer. They are sure that computed radiology (CR) will be the most acceptable way of changing traditional radiology to the digital imaging principle in primary, municipal health care in the near future.     

Do we have any solid evidence of clinical utility about the pathophysiology of schizophrenia?

A diagnosis of schizophrenia, as in most of psychiatric practice, is made largely by eliciting symptoms with reference to subjective, albeit operationalized, criteria. This diagnosis then provides some rationale for management. Objective diagnostic and therapeutic tests are much more desirable, provided they are reliably measured and interpreted. Definite advances have been made in our understanding of schizophrenia in recent decades, but there has been little consideration of how this information could be used in clinical practice. We review here the potential utility of the strongest and best replicated risk factors for and manifestations of schizophrenia within clinical, epidemiological, cognitive, blood biomarker and neuroimaging domains. We place particular emphasis on the sensitivity, specificity and predictive power of pathophysiological indices for making a diagnosis, establishing an early diagnosis or predicting treatment response in schizophrenia. We conclude that a number of measures currently available have the potential to increase the rigour of clinical assessments in schizophrenia. We propose that the time has come to more fully evaluate these and other well replicated abnormalities as objective potential diagnostic and prognostic guides, and to steer future clinical, therapeutic and nosological research in this direction.     

Directing the evolution of Rubisco and Rubisco activase: first impressions of a new tool for photosynthesis research

During the last decade the practice of laboratory-directed protein evolution has become firmly established as a versatile tool in biochemical research by enabling molecular evolution toward desirable phenotypes or detection of novel structure-function interactions. Applications of this technique in the field of photosynthesis research are still in their infancy, but recently first steps have been reported in the directed evolution of the CO(2)-fixing enzyme Rubisco and its helper protein Rubisco activase. Here we summarize directed protein evolution strategies and review the progressive advances that have been made to develop and apply suitable selection systems for screening mutant forms of these enzymes that improve the fitness of the host organism. The goal of increasing photosynthetic efficiency of plants by improving the kinetics of Rubisco has been a long-term goal scoring modest successes. We discuss how directed evolution methodologies may one day be able to circumvent the problems encountered during this venture.     

The duty to recontact: attitudes of genetics service providers

The term "duty to recontact" refers to the possible ethical and/or legal obligation of genetics service providers (GSPs) to recontact former patients about advances in research that might be relevant to them. Although currently this practice is not part of standard care, some argue that such an obligation may be established in the future. Little information is available, however, on the implications of this requirement, from the point of view of GSPs. To explore the opinions of genetics professionals on this issue, we sent a self-administered questionnaire to 1,000 randomly selected U.S. and Canadian members of the American Society of Human Genetics. We received 252 completed questionnaires. The major categories of respondents were physician geneticist (41%), Ph.D. geneticist (30%), and genetic counselor (18%); 72% of the total stated that they see patients. Respondents indicated that responsibility for staying in contact should be shared between health professionals and patients. Respondents were divided about whether recontacting patients should be the standard of care: 46% answered yes, 43% answered no, and 11% did not know. Those answering yes included 44% of physician geneticists, 53% of Ph.D. geneticists, and 31% of genetic counselors; answers were statistically independent of position or country of practice but were dependent on whether the respondent sees patients (43% answered yes) or not (54% answered yes). There also was a lack of consensus about the possible benefits and burdens of recontacting patients and about various alternative methods of informing patients about research advances. Analysis of qualitative data suggested that most respondents consider recontacting patients an ethically desirable, but not feasible, goal. Points to consider in the future development of guidelines for practice are presented.     

The endoscopist and malignant and non-malignant biliary obstruction

Patients with biliary strictures often represent a diagnostic and therapeutic challenge, due to the site and complexity of biliary obstruction and wide differential diagnosis. Multidisciplinary decision making is required to reach an accurate and timely diagnosis and to plan optimal care. Developments in endoscopic ultrasound and peroral cholangioscopy have advanced the diagnostic yield of biliary endoscopy, and novel optical imaging techniques are emerging. Endoscopic approaches to biliary drainage are preferred in most scenarios, and recent advances in therapeutic endoscopic ultrasound allow drainage where the previous alternatives were only percutaneous or surgical. Here we review recent advances in endoscopic practice for the diagnosis and management of biliary strictures. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni and Peter Jansen.     

Controlled addition of small amounts of oxygen with membranes

Summary In some fermentations micro-aerobic conditions are desirable. The controlled addition of trace amounts of oxygen may be achieved by bubble free oxygen supply using silicon membrane tube, operated in dead-end mode. The small oxygen uptake rate is accurately determined with this self-constructable device.     

Industrial strain improvement: Mutagenesis and random screening procedures

Industrial strain improvement plays a central role in the commercial development of microbial fermentation processes. In recent years new procedures such as rational screening and genetic engineering have begun to make a significant contribution to this activity but mutagenesis and selection - so-called ‘random screening’ - is still a cost-effective procedure, and for reliable short-term strain development is frequently the method of choice. The current practice of strain improvement by mutagenesis and selection is a highly developed technique drawing on the latest advances from a wide range of scientific and technical disciplines. Mutagenic procedures can be optimized in terms of type of mutagen and dose, mutagen specificity effects can be taken into account and mutagenesis itself can be enhanced or directed in order to obtain the maximum frequency of desirable mutant types among the isolates to be screened. Screens can be designed to allow maximum expression of the desirable mutant types and the application of statistically-based screening procedures will maximize the probability of detecting them. Automated procedures can be developed using robotics and microprocessors to increase the numbers of isolates that can be processed through a screen per unit time. The relationship between screening and production conditions can be organized so as to minimize the probability of improved isolates selected by the screen failing to scale up.     

Understanding the classics: the unifying concepts of transgressive segregation,inbreeding depression and heterosis and their central relevance for crop breeding

Transgressive segregation and heterosis are the reasons that plant breeding works. Molecular explanations for both phenomena have been suggested and play a contributing role. However, it is often overlooked by molecular genetic researchers that transgressive segregation and heterosis are most simply explained by dispersion of favorable alleles. Therefore, advances in molecular biology will deliver the most impact on plant breeding when integrated with sources of heritable trait variation – and this will be best achieved within a quantitative genetics framework. An example of the power of quantitative approaches is the implementation of genomic selection, which has recently revolutionized animal breeding. Genomic selection is now being applied to both hybrid and inbred crops and is likely to be the major source of improvement in plant breeding practice over the next decade. Breeders’ ability to efficiently apply genomic selection methodologies is due to recent technology advances in genotyping and sequencing. Furthermore, targeted integration of additional molecular data (such as gene expression, gene copy number and methylation status) into genomic prediction models may increase their performance. In this review, we discuss and contextualize a suite of established quantitative genetics themes relating to hybrid vigour, transgressive segregation and their central relevance to plant breeding, with the aim of informing crop researchers outside of the quantitative genetics discipline of their relevance and importance to crop improvement. Better understanding between molecular and quantitative disciplines will increase the potential for further improvements in plant breeding methodologies and so help underpin future food security.     

Guidelines on appropriate indications for upper gastrointestinal endoscopy. Working Party of the Joint Committee of the Royal College of Physicians of London,Royal College of Surgeons of England,Royal College of Anaesthetists,Association of Surgeons,the British Society of Gastroenterology,and the Thoracic Society of Great Britain.

Upper gastrointestinal endoscopy is a valuable diagnostic tool, but for an endoscopy service to be effective it is essential that it is not overloaded with inappropriately referred patients. A joint working party in Britain has considered the available literature on indications for endoscopy, assessed standard practice through a questionnaire, and audited randomly selected cases using an independent panel of experts and an American database system. They used these data to produce guidelines on the appropriate and inappropriate indications for referral for endoscopy, although they emphasise that under certain circumstances there may be reasons to deviate from the advice given. The need for endoscopy is most difficult to judge in patients with dyspepsia, and this aspect is discussed in detail. Early endoscopy will often prove more cost effective than delaying until the indications are clearer.     

Design and analysis of gastroenterology (GI) clinic in Digestive Health Center of University of Wisconsin Health

This paper is devoted to the design and analysis of the gastroenterology (GI) clinic in the Digestive Health Center (DHC) of University of Wisconsin Health. The DHC will consolidate several existing clinic and endoscopy locations into a single center. First, the work flow at a current GI clinic is studied. A Markov chain model is developed and then extended to non-Markovian case to evaluate patient average length of stay and staff utilization. The model is validated by the data observed in the clinic. It is shown that the model can provide accurate estimation of system performance. Then, using such a model, design options of the new GI clinic in the DHC are studied. To investigate the impact of different system configurations, what-if analyses are carried out and different patient check-out processes are investigated. Finally, recommendations for enhancing service at the new GI clinic are proposed to the DHC leadership.     

Upper gastrointestinal endoscopy: its effects on patient management.

Out of 95 patients referred for upper gastrointestinal endoscopy after a barium-meal examination, 44 underwent a change in management. Some changes were minor but in 12 patients a decision on surgery was required. Seven of these patients were among a group of 13 for whom the referring consultant would have recommended laparotomy had endoscopy not been available, while the other five were subjected to an unplanned laparotomy. These findings support the practice of performing endoscopy on patients whose symptoms are not fully explained by barium-meal examination, especially patients aged over 45. In such cases the procedure also seems to be cost-effective.     

Genetic engineering of flavonoid pigments to modify flower color in floricultural plants

Recent advances in genetic transformation techniques enable the production of desirable and novel flower colors in some important floricultural plants. Genetic engineering of novel flower colors is now a practical technology as typified by commercialization of a transgenic blue rose and blue carnation. Many researchers exploit knowledge of flavonoid biosynthesis effectively to obtain unique flower colors. So far, the main pigments targeted for flower color modification are anthocyanins that contribute to a variety of colors such as red, pink and blue, but recent studies have also utilized colorless or faint-colored compounds. For example, chalcones and aurones have been successfully engineered to produce yellow flowers, and flavones and flavonols used to change flower color hues. In this review, we summarize examples of successful flower color modification in floricultural plants focusing on recent advances in techniques.     

Progress and Challenges in Agricultural Applications of Arbuscular Mycorrhizal Fungi

Arbuscular mycorrhiza is a widespread interaction between plant roots and mutualistic fungi that both promotes plant mineral nutrition and supports stability in many natural ecosystems. Given the demand in current agriculture for these ecosystem services, it appears desirable to further integrate this interaction in current management schemes. While two different approaches can be identified in this regard, a number of problems have limited the agricultural application of mycorrhiza to date. In this review, the sensitivity of arbuscular mycorrhizal fungi to certain agricultural management methods, the functional variability of arbuscular mycorrhizal fungi, and the variability of plant responsiveness will be discussed in particular. In addition we will focus on recent advances in the study of mycorrhiza in natural ecosystems, and illustrate how such knowledge might be used to further the integration of arbuscular mycorrhizal fungi in agricultural regimes, and so increase the sustainability and robustness of current practice.     

Food security in 2044: How do we control the fungal threat?

Plant fungal pathogens place considerable strain on agricultural productivity and threaten global food security. In recent decades, advances in crop breeding, farming practice and the agrochemical industry have allowed crop yields to keep pace with food demand. In this opinion article, we speculate on which recent technological advances will allow us to maintain this situation into the future. We take inspiration that it is 25 y since the first plant disease resistance genes were cloned, and imagine if and how agricultural control of pathogens will be achieved by the year 2044. We examine which technologies are best poised to make the jump from lab bench to field application, and propose that future control measures will likely depend on effective integrated disease management.     

Medication and skilled work

There is increasing interest in the way in which drugs impair performance. This has arisen because some may impair day-to-day skills of those whose occupations demand vigilance and motor skill, and of those who are involved in decision making or where interpersonal relations are crucial. For many years the position was adopted, at least in certain occupations where impaired performance could be a danger to others, that the use of any drug should preclude employment. However, recent advances in therapeutics and a greater understanding of drug action in man has made this rather uncomplicated view of life less tenable, and there is now an increasing desire that advances in therapy should, if at all possible, be available to occupational groups, such as airline pilots. In this way the adverse effect which a drug may have on performance has become an important aspect of its clinical profile. Hypnotics appropriate for transient insomnia, which may arise from the irregularity of rest inherent in many occupations, need to be free of residual effects, antihistamines that are sedative must be avoided, and drugs used in the management of mild hypertension, often during the important years of middle life, must be as free as possible from central effects. And it must be emphasized that these drugs are often used by active, healthy or near healthy individuals. The issues involved in the safe use of a particular drug by a particular individual are complex, and as with all aspects of therapeutics it is sometimes necessary to balance efficacy and adverse effects.