The European Practice Assessment program provides feedback and outreach visits to primary care practices to facilitate quality improvement in five domains (infrastructure, people, information, finance, and quality and safety). We examined the effectiveness of this program in improving management in primary care practices in Germany, with a focus on the domain of quality and safety.
Methods:
In a before–after study, 102 primary care practices completed a practice assessment using the European Practice Assessment instrument at baseline and three years later (intervention group). A comparative group of 102 practices was included that completed their first assessment using this instrument at the time of the intervention group’s second assessment. Mean scores were based on the proportion of indicators for which a positive response was achieved by all of the practices, on a scale of 0 to 100.
Results:
We found significant improvements in all domains between the first and second assessments in the intervention group. In the domain of quality and safety, improvements in scores (mean scores were based on the proportion of indicators for which a positive response was achieved by all of the practices, on a scale of 0 to 100) were observed in the following dimensions: complaint management (from a mean score of 51.2 at first assessment to 80.7 at second assessment); analysis of critical incidents (from 79.1 to 89.6); and quality development, quality policy (from 40.7 to 55.6). Overall scores at the time of the second assessment were significantly higher in the intervention group than in the comparative group.
Interpretation:
Primary care practices that completed the European Practice Assessment instrument twice over a three-year period showed improvements in practice management. Our findings show the value of the quality-improvement cycle in the context of practice assessment and the use of established organizational standards for practice management with the Europeaen Practice Assessment.A variety of quality-improvement initiatives in health care management have been implemented in most health care systems.1,2 Countries such as Australia, New Zealand, the United Kingdom and the United States have a long tradition in, and established standards for, quality management in primary care. In Canada, such initiatives in primary care are in their infancy, despite support by the federal Primary Health Care Transition Fund since 2000.3 In Ontario, a comprehensive book was recently issued that provides recommendations on practice management and clinical indicators for improving quality in primary care settings in the province.4 The indicators were adopted and refined from the Royal New Zealand College of General Practitioners, the Royal Australian College of General Practitioners’ National Expert Committee on Standards for General Practices, the TOPAS–Europe Association European Practice Assessment, the United Kingdom’s Quality and Outcomes Framework and the Canadian Institute for Health Information.In Germany, similar developments took place. In 2005, the German government stipulated that health care providers implement a system of annual assessment of quality management.5 One of the systems available to practices is the European Practice Assessment (www.epa-qm.de), a validated instrument based on quality indicators for assessing practice management.6 The five key domains of the European Practice Assessment instrument and their respective dimensions are described in Figure 1.Open in a separate windowFigure 1:The domains and dimensions (and number of indicators) of the European Practice Assessment instrument used to measure the quality of practice management in primary care practices. For an example of how the pentagon shape is used to provide feedback to individual practices, see Appendix 1 (available at www.cmaj.ca/lookup/suppl/doi:10.1503/cmaj.110412/-/DC1). GP = general practitioner.The European Practice Assessment is used to help general practices both assess and improve their quality of practice management set against predefined criteria with embedded quality indicators. The improvement process is ongoing (e.g., through plan–do–study–act cycles7): each step is reviewed and redesigned with a view to improving the quality of the end product, thereby fostering continuous improvement.8 The multifaceted strategy has three essential components: assessment and feedback using validated instruments based on quality indicators; external support through an outreach educational visit by a trained visitor (physician or nurse) to support the practice in improving areas of management identified by the practice;9 and formal accreditation by an external organization.Three requirements have to be fulfilled by practices to receive accreditation: achieve a positive response for more than 50% of the indicators; meet predefined safety indicators (e.g., the vaccination status of staff regarding hepatitis B vaccination is recorded and medical equipment is checked regularly according to national regulations); and highlight areas for continuous quality improvement.Accreditation is one method for assessing and benchmarking the performance of general practice care across a broad range of clinical and organizational domains. It describes a formal process of self-assessment and external and independent peer review to encourage best management practice and can result in recommendations for continuous improvement of safety and quality in the practice.8 Practice accreditation can be used for different purposes: quality control, regulation, quality improvement, providing data on performance, and marketing.8 In Germany, it is used for quality improvement, leading to a certificate.We conducted a study to determine whether improvements in practice management occurred in general practices that completed the European Practice Assessment twice over three years, compared with general practices that completed the European Practice Assessment once. We focused our analysis on the domain of quality and safety, expecting an association between practice organization and quality improvement.10,11 We hypothesized that the initial use of the European Practice Assessment and reassessment with it three years later would result in improved scores in the dimensions and indicators within the domain of quality and safety. 相似文献
Abstract: A patient presented with a small-bowel obstruction associated with signs and symptoms of botulism. Fecal cultures were positive for viable Clostridium botulinum. This case emphasizes the importance of a broad differential diagnosis and doing a complete examination to account for all signs and symptoms.The case: A 45-year-old man who was previously healthy presented to the emergency department with acute-onset abdominal distension and mild blurry vision. Despite self-induced vomiting, his abdominal distension worsened. A small-bowel obstruction was diagnosed based on his clinical presentation and the results of radiography (Figure 1). A computed tomography scan of the patient''s abdomen confirmed the obstruction, but did not add any further information. Despite nasogastric suctioning for 12 hours, the patient''s abdomen continued to distend, bowel sounds became diminished and signs of peritonitis (guarding, tenderness) appeared. To avoid bowel perforation, an exploratory laparotomy was performed. No obvious cause of the obstruction was identified.Open in a separate windowFigure 1: Abdominal radiograph obtained while the patient was in an upright position. Note the small-bowel obstruction with multiple air–fluid levels.A neurologist was consulted 5 days later to assess the patient''s worsening neurologic symptoms, including ptosis (Figure 2), diplopia, dysphagia, aphonia and dry mouth. On examination, the patient''s vital signs were normal. Performing the Valsalva manoeuvre did not change his heart rate The patient had bilateral paralysis of cranial nerves 3, 4, 6, 7, 9 and 10. The patient''s pupils were initially dilated but they were sluggishly reactive to light. One day later, his pupils were unreactive to light (Figure 3). Neck flexion was weak, but appendicular strength was preserved. A neurophysiological assessment with repetitive nerve stimulation was performed, which showed an electro-incremental response on high-frequency stimulation, which was suggestive of a presynaptic disorder.Open in a separate windowFigure 2: The patient had ptosis of both eyes.Open in a separate windowFigure 3: Six days after the patient presented with abdominal distension and blurry vision, his pupils became unresponsive to light.Botulism was highly suspected based on the clinical presentation and the neurophysiological findings. Serum, stool and gastric contents were sent for testing. A detailed history revealed no exposure to suspicious foods, and he had no sick contacts. Public health was notified immediately. We administered antitoxin based on his clinical presentation and the the progression of his pupillary symptoms. There was no subsequent progression of his symptoms. The patient''s bowel sounds returned 6 days after the exploratory laparotomy. The patient received nutrition through a nasogastric tube until his neurologic deficits improved. Speech sounds and other deficits gradually improved over several weeks.Initial samples of the patient''s serum, feces and gastric contents as well as food sources were all negative for botulinum neurotoxin and viable Clostridium botulinum. Two fecal samples, taken about 2 and 8 weeks after the onset of symptoms, both tested positive for viable C. botulinum type B. Because the results were positive for C. botulinum type B and negative for toxins, we suspected colonization botulism rather than foodborne botulism. The patient received no further therapy because his symptoms were improving. He remained in hospital with supportive care for 1 month until his dysphagia resolved.Botulism is a rare neuroparalytic illness caused by a neurotoxin produced by C. botulinum. Botulinum neurotoxin causes irreversible inhibition of acetylcholine release, which affects both the autonomic and somatic systems.1 Although rare, it remains an important public health concern. From 2000 to 2005, there was an average of 5.8 cases of botulism reported each year in Canada.2–5 A complete review of the patient''s systems and a physical examination, including cranial nerves, will help to establish the diagnosis.6There are 4 natural forms of clinical botulism: foodborne, infant, wound and adult intestinal colonization (Open in a separate windowOnce botulism is suspected, the local public health unit and the Botulism Reference Service for Canada should be notified immediately. Samples of the patient''s feces and gastric contents as well as suspect foods should be tested for botulinum neurotoxin and viable C. botulinum. Serum should be tested for botulinum neurotoxin. After appropriate samples are collected, treatment with antitoxin should be considered. Antitoxin against type A, B and E is typically administered. The benefit of this therapy is greatest within the first 24 hours after the onset of symptoms. Respiratory monitoring and support is essential. If flaccid paralysis occurs, it can not be reversed by antitoxin; however, the antitoxin neutralizes circulating toxins and prevents progression of symptoms. 相似文献
INFLIXIMAB IS A CHIMERIC ANTI-TUMOUR NECROSIS FACTOR-α antibody that is efficacious in treating Crohn''s disease. However, its immunomodulatory properties increase susceptibility to opportunistic infections. We present a case of cutaneous Nocardia infection in a patient who was taking infliximab for Crohn''s disease. The case illustrates the challenges in the diagnosis and management of this disease and serves as a reminder of the complications associated with the use of immunomodulatory agents.A 45-year-old HIV-negative man with fistulous Crohn''s disease had a history of inadequate disease control despite ongoing prednisone therapy. He had previously taken budesonide, mesalamine, ciprofloxacin and metronidazole in attempts to induce remission of his inflammatory bowel disease. The patient was born in Canada and, other than a 1-week holiday to Mexico 10 years before presentation, had travelled only locally. He denied a family history of tuberculosis, and he had never worked in a health care facility. Infliximab was introduced, and the patient received 3 infusions of 5 mg/kg at baseline and 2 and 6 weeks later. After he received his third infusion, prednisone was tapered to 40 mg at a rate of 5 mg weekly. One month after the third infusion, in February 2000, he reported multiple erythematous papulopustular lesions on his right leg (Fig. 1). There was no associated lymphadenopathy, cough, shortness of breath, fever or constitutional symptoms. He denied a history of insect bites, but in November 1999 he had received cuts to his right leg from a metal blade when at work. He had not immersed the leg in a whirlpool or swimming pool around the time of the leg injury. The patient continued to receive further infliximab infusions (at weeks 12 and 18 after baseline), and the lesions were treated with cloxacillin for suspected Staphylococcus aureus infection. Since improvement was minimal, a skin biopsy was performed in July 2000. Granulomatous inflammation was present, and acid-fast bacilli were visualized (Fig. 2). Cultures sent for mycobacteriology and mycology were incubated at 35°C for 8 weeks, but the results from the mycobacteriology culture proved negative. A polymerase chain reaction assay for Mycobacterium tuberculosus was also negative. A clinical diagnosis of M. marinum infection was made, and the patient''s antibiotic regimen was changed to minocycline. A tuberculin skin test was not performed; since the patient was immunocompromised, a negative result would not have excluded the disease. A chest radiograph appeared normal.Open in a separate windowFig. 2: Acid-fast bacilli visualized in skin biopsy.Open in a separate windowFig. 1: Multiple erythematous papulopustular lesions on the patient''s leg 1 month after the third infusion of infliximab.The patient failed to respond to the minocycline therapy, and he was referred for infectious disease consultation in October 2000. The infliximab infusions were discontinued, and 2 more skin biopsies were performed, with acid-fast bacilli visualized in both specimens. The patient was given trimethoprim–sulfamethoxazole, and his lesions began to heal slowly but progressively.Acid-fast bacilli were recovered from the second set of biopsies, and specific instructions were given to incubate the cultures at 30°C and 35°C to ensure that M. marinum, if present, would be detected. Again, the cultures failed to recover organisms. The laboratory, using polymerase chain reaction restriction analysis of the 439-base pair segment of the gene encoding a 65-kDa heat shock protein,1 identified the presence of Nocardia species. Nevertheless, Nocardia organisms still could not be recovered in culture, and therefore final speciation could not be performed.The patient resumed taking prednisone, and the dosage was increased in order to ameliorate the symptoms of his Crohn''s disease. The trimethoprim–sulfamethoxazole therapy was continued until late 2003, and the dosage was reduced over the subsequent months. Complete healing of the lesions was eventually achieved 4 years after therapy was initiated. 相似文献
Information on health disparities between Aboriginal and non-Aboriginal populations is essential for developing public health programs aimed at reducing such disparities. The lack of data on disparities in birth outcomes between Inuit and non-Inuit populations in Canada prompted us to compare birth outcomes in Inuit-inhabited areas with those in the rest of the country and in other rural and northern areas of Canada.
Methods
We conducted a cohort study of all births in Canada during 1990–2000 using linked vital data. We identified 13 642 births to residents of Inuit-inhabited areas and 4 054 489 births to residents of all other areas. The primary outcome measures were preterm birth, stillbirth and infant death.
Results
Compared with the rest of Canada, Inuit-inhabited areas had substantially higher rates of preterm birth (risk ratio [RR] 1.45, 95% confidence interval [CI] 1.38–1.52), stillbirth (RR 1.68, 95% CI 1.38–2.04) and infant death (RR 3.61, 95% CI 3.17–4.12). The risk ratios and absolute differences in risk for these outcomes changed little over time. Excess mortality was observed for all major causes of infant death, including congenital anomalies (RR 1.64), immaturity-related conditions (RR 2.96), asphyxia (RR 2.43), sudden infant death syndrome (RR 7.15), infection (RR 8.32) and external causes (RR 7.30). Maternal characteristics accounted for only a small part of the risk disparities. Substantial risk ratios for preterm birth, stillbirth and infant death remained when the comparisons were restricted to other rural or northern areas of Canada.
An outbreak of zombification wreaked havoc recently in Canada and the rest of the world. Mathematical models were created to establish the speed of zombie infection and evaluate potential scenarios for intervention, mainly because mathematicians don’t have anything better to do with their time. We review the development of these models and their effect on the undead.In August 2009, a new disease emerged in North America and quickly made its way around the world.1 Media reports suggest the outbreak began in Ottawa2 but rapidly spread across Canada3,4 and was transported thereafter to the United States5 and the United Kingdom.6,7The infection resulted in a new species of human, classified as nonmortuus contagio, but known in the popular press as “zombie”, from the Congolese nzambi, meaning “spirit of a dead person.” As the name implies, the outbreak resulted in a resurgence of the previously deceased. Clinical signs included discoloration around the eyes, open wounds and rotting flesh, with organs and bodily functions operating at minimal levels.Initial studies reported that the zombies did not feel pain, but these findings could not be verified because of the zombification of the researchers in question. When asked for comment, the lead author of one such study said, “Grrrnn, aaarghhh, huuuuuungry!” When questioned in more detail, he replied, “Braaaaiiiinnnnsss!” No further information is available from the interview.The cause of the virus remains unknown. Anecdotal evidence suggests that zombies can be defeated by guns, the army, eventual starvation or Dire Straits records.New diseases are generally investigated using experiments on infected people, clinical trials or medical observation. Unfortunately, because of the rapid zombification of scientists, epidemiologists and doctors, society was left with only one group of technocrats who remained uninfected: mathematicians. Fortunately, during the time at which the outbreak occurred, members of this group had not been invited to parties and thus remained entirely uninfected.A mathematical model for zombie infection8 was quickly designed (Figure 1). As shown by the model, humans could be infected by contact with a zombie, whereas zombies could be created either through the conversion of humans or reanimation of the dead. The model assumed that zombies could be killed in encounters with humans, as often happened when humans ran over zombies in their cars. Initially, such deaths were assumed by authorities to be part of a concerted effort at eradication of zombies, but were later revealed to be simply a result of rush hour. Some drivers were surprised when these recently deceased zombies returned to life and attacked them. Other drivers simply handed the zombies some spare change and waited for the reanimated creatures to clean their windshields.Open in a separate windowFigure 1Schematic diagram of the basic mathematical model (black arrows). Humans (friendly Canadians, in this example) can either die naturally or be converted into zombies — which is not terribly pleasant, but does come with that nifty jacket and tie. Zombies can reanimate the dead or be killed by humans (although it must be said that the latter doesn’t bother them too much). Possible intervention include quarantine of the zombies (green arrow), a potential cure (blue arrow) or impulsive attacks (red arrow).Open in a separate windowThe model showed two equilibria: the disease-free equilibrium (with no zombies) and the doomsday equilibrium (where everyone is a zombie). The application of a linear stability analysis showed that — in the absence of further interventions — the disease-free equilibrium was unstable and the doomsday equilibrium was stable. This finding was not promising.Simulations based on a city of roughly 500 000 people demonstrated that an entire such city would be replaced by zombies after about four days (Figure 2A). Were this mass replacement of a population to occur in a city such as Ottawa, it may be unlikely anyone would notice. Nevertheless, nearby cities such as Montreal would no longer be in the bagel-supplying business in such a scenario, and that result would be serious.Open in a separate windowFigure 2Projected population dynamics (based on type of intervention) in the context of a zombie outbreak. In the basic model (A), zombies eradicate humans after 4 days, leaving nobody to host daytime variety television shows or stop you from entering nightclubs (i.e., no loss there). (B): Quarantine delays the inevitable. Slightly. (C): A cure allows zombies to live in harmony with humans, which would be more fun for zombies than humans. (D): Only episodes of blind, aggressive, unfeeling violence are effective. And that’s just on the part of humans.Given this model, even a small outbreak would lead to a collapse of society as we know it. Explaining to the mathematicians that this outcome might be a bad thing took time because, initially, they were not able to see the downside. However, they were quickly mobilized after realizing their supply of caffeine and science fiction DVDs would dry up.Three interventions were proposed. The first was quarantine (Figure 1, green arrow), whereby a small proportion of the zombies would be kept in isolation. But given that the infection was so virulent, even leaving a few zombies in the wild would result in a restart of the outbreak. Including quarantine thus made no difference to the stability of the doomsday equilibrium (Figure 2B). That was a bit of a downer, to be honest.The second intervention was a theoretical cure that would convert zombies back into humans (Figure 1, blue arrow). Although the mathematicians were reminded that such a cure was entirely theoretical and likely could not be developed within four days, they were quite taken with the idea of proving results based on things that couldn’t possibly exist. This response was annoying, because they should have been concentrating on zombies instead.With a cure, humans and zombies could coexist. But unless the cure were 100% effective, humans would survive only in small numbers (Figure 2C) — most likely in shopping malls, abandoned farmhouses or the Winchester pub.Finally, the idea of impulsive attacks was considered (Figure 1, red arrow). This intervention would involve an escalating series of discrete attacks on the zombies, using an advanced mathematical theory called impulsive differential equations. These equations are similar to ordinary differential equations, except that sometimes they jump up onto tables, paint themselves purple and start singing show tunes for no reason whatsoever.The projected outcome of this intervention was more promising. At regular intervals, humans would mobilize their resources and attack the zombies. Each attack would be carried out with more force than the last one. The humans would keep fighting with increasing intensity until either the zombies were destroyed or the humans were torn apart from limb to limb and their flesh consumed by the ghoulish undead. Still, you’ve got to laugh, haven’t you? If humans could manage these impulsive attacks, the zombies could be destroyed after 10 days (Figure 2D).The overall model had limitations, of course. The numerical contributions of natural births and deaths had been ignored because of the brief timescale involved and the unlikelihood that mathematicians would be engaged in breeding. Inclusion of population demographics in the model suggests a limitless supply of new bodies would be available for zombies to infect, resurrect and convert. We must therefore act quickly and decisively to eradicate zombies before they eradicate us. 相似文献
Because many Aboriginal Canadians had severe cases of pandemic (H1N1) 2009 influenza, they were given priority access to vaccine. However, it was not known if the single recommended dose would adequately protect people at high risk, prompting our study to assess responses to the vaccine among Aboriginal Canadians.
Methods:
We enrolled First Nations and Métis adults aged 20–59 years in our prospective cohort study. Participants were given one 0.5-mL dose of ASO3-adjuvanted pandemic (H1N1) 2009 vaccine (Arepanrix, GlaxoSmithKline Canada). Blood samples were taken at baseline and 21–28 days after vaccination. Paired sera were tested for hemagglutination-inhibiting antibodies at a reference laboratory. To assess vaccine safety, we monitored the injection site symptoms of each participant for seven days. We also monitored patients for general symptoms within 7 days of vaccination and any use of the health care system for 21–28 days after vaccination.
Results:
We enrolled 138 participants in the study (95 First Nations, 43 Métis), 137 of whom provided all safety data and 136 of whom provided both blood samples. First Nations and Métis participants had similar characteristics, including high rates of chronic health conditions (74.4%–76.8%). Pre-existing antibody to the virus was detected in 34.3% of the participants, all of whom boosted strongly with vaccination (seroprotection rate [titre ≥ 40] 100%, geometric mean titre 531–667). Particpants with no pre-existing antibody also responded well. Fifty-eight of 59 (98.3%) First Nations participants showed seroprotection and a geometric mean titre of 353.6; all 30 Métis participants with no pre-existing antibody showed seroprotection and a geometric mean titre of 376.2. Pain at the injection site and general symptoms frequently occurred but were short-lived and generally not severe, although three participants (2.2%) sought medical attention for general symptoms.
Interpretation:
First Nations and Métis adults responded robustly to ASO3-adjuvanted pandemic (H1N1) 2009 vaccine. Virtually all participants showed protective titres, including those with chronic health conditions.
Trial registration:
ClinicalTrials.gov trial register no. NCT.01001026.During the first wave of the H1N1 pandemic in Canada in 2009, some First Nations communities were severely affected, with younger adults and children most at risk for severe disease.1,2 Whereas Aboriginal Canadians make up 3.4% of the population (with 1.14 million people), they accounted for 16% of admissions to hospital during the first wave of the pandemic, and 43% of Aboriginal patients had underlying medical conditions.3 The increased rate of severe disease might have resulted from residential crowding, prevalence of chronic health conditions, delayed access to health care or suboptimal immune responses to infection.4 When a federally funded, ASO3-adjuvanted (squalene/tocopherol) pandemic vaccine became available for Canadians later in 2009,5 Aboriginal people were given priority access to it.3 However, dosing requirements at the time were tentative. Previous studies of an ASO3-adjuvanted influenza A (H5N1) vaccine established that two doses were needed for immunity in adults.6 Because the 2009 influenza (H1N1) pandemic occurred without warning, no prepandemic studies had been done with vaccines based on this novel swine-derived virus.7The ASO3-adjuvanted pandemic (H1N1) 2009 vaccine manufactured in Canada (Arepanrix, GlaxoSmithKline, Laval, Quebec) was released for public use as soon as it was available, unstudied, to mitigate morbidity during the pandemic’s second wave, which was already in progress. A single 3.75-μg dose of hemagglutinin was recommended for adults using the preliminary results of a European trial of another ASO3-adjuvanted vaccine (Pandemrix, GlaxoSmithKline, Rixensart, Belgium) given to 65 adults aged 18–60 years.8 The European product was believed to be equivalent to the Canadian-made vaccine, but this had not yet been shown.We wondered if the recommended single dose would be adequate for Aboriginal Canadian adults given their heightened risk of severe influenza during the first wave. We were unable to identify any previous studies of influenza vaccines involving Aboriginal Canadians to determine if their responses would be similar to other Canadians or to the healthy European study participants on whom the dosing recommendation was based. Consequently, we undertook a study involving First Nations and Métis adults to assess their responses to the pandemic vaccine. 相似文献
Abstract: Neurofibromatosis type 1 is a common autosomal dominant condition that affects about 1 in 5000 people. We describe a 75-year-old man who, in addition to many classic developmental changes of the disease in his skin, eyes and nervous system, had blindness in his right eye as a complication.Case: A 75-year-old man with long-standing neurofibromatosis type 1 was admitted because the vision in his right eye had decreased progressively over 3 months. Physical examination showed disseminated cutaneous and subcutaneous neurofibromas of varying size (Figure 1) and café-au-lait spots (Figure 2). The patient had a visual acuity of 6/18 (20/60) in his right eye and Lisch nodules (iris hamartomas) (Figure 3). A neurologic examination showed no abnormalities other than his loss of vision. Axial T1-weighted magnetic resonance imaging of the brain and orbits (Figure 4) showed an isointense mass lateral to the right optic nerve that appeared atrophic and pushed to the left. The mass showed a hyperintense signal on T2-weighted images with contrast enhancement. These findings are compatible with glioma of the optic nerve.Open in a separate windowFigure 1: Disseminated cutaneous and subcutaneous neurofibromas of varying size on the torso of a patient with neurofibromatosis type 1.Open in a separate windowFigure 2: A café-au-lait spot on the patient''s right knee.Open in a separate windowFigure 3: Lisch nodules on the left iris.Open in a separate windowFigure 4: T1-weighted axial magnetic resonance imaging of the brain and orbits, showing an isointense mass lateral to the right optic nerve (white arrow) that appears atrophic and pushed to the left (black arrow on inset).Axial and coronal magnetic resonance imaging (Figure 5) showed a mass in the left parietal lobe with hyperintensity on T2-weighted images and hypointensity on T1-weighted images. After a contrast medium was administered, the lesion showed a thickened, enhanced wall with a central necrotic area. These findings are compatible with astrocytoma.Open in a separate windowFigure 5: T2-weighted axial (left) and coronal (right) magnetic resonance imaging showing a mass with hyperintensity (arrow) in the left temporal lobe. After administration of a contrast medium, the lesion is visible with a thickened enhanced wall and a central necrotic area.Because of slight enlargement and increased hardness of the subcutaneous lesions, an excisional biopsy was performed. Histology showed delicate fascicles consisting of cells with oval or spindle-shaped nuclei, scant cytoplasm and round cells with entrapped axons (Figure 6). Only scattered neoplastic Schwann cells were stained during immunostaining for S-100 protein (Figure 7). This pattern is consistent with neurofibroma. The patient chose not to receive further treatment and was discharged.Open in a separate windowFigure 6: Biopsy specimen of a subcutaneous neurofibroma showing spindle-shaped and round cells with entrapped axons (hematoxylin and eosin, original magnification ×10).Open in a separate windowFigure 7: Only scattered neoplastic Schwann cells (arrow) are stained after immunostaining for S-100 protein. Normally, S-100 protein is present in cells derived from the neural crest, such as Schwann cells. It can be found in melanoma cells, in malignant peripheral nerve sheath tumours and in certain types of sarcomas.Neurofibromatosis type 1, also known as von Recklinghausen disease,1 is characterized by changes in pigmentation and the growth of tumours along nerves in the skin and other parts of the body. It is caused by a defect in a tumour-suppressing gene on chromosome 17q11.2. Normally the gene produces neurofibromin, a protein that regulates cellular proliferation.2 With the gene mutation, the lack of neurofibromin results in overgrowth of cells from neural crest areas in both the central nervous system (causing Schwann cell tumours on virtually every nerve) and the skin. All people who inherit a copy of the mutated gene are affected. As the pattern of inheritance is autosomal dominant, only 1 copy of the defective gene is needed to cause the condition. However, it is not necessary to have an affected parent. About 30%–50% of patients have a new mutation.Neurofibromatosis type 2 is a much rarer form of neurofibromatosis caused by mutations in both alleles of a different tumour suppressor gene on chromosome 22q12.1.About 1 in 3000–5000 individuals are affected by neurofibromatosis type 1, without differences related to ethnic background.3 Pigmented small macules and café-au-lait patches are often present shortly after birth, although neurofibromas are rare in early childhood. In later childhood and adolescence, both neurofibromas and pigmented lesions become common. Clinical manifestations are variable (4Table 1Open in a separate windowA diagnosis of neurofibromatosis type 1 is based on clinical findings. The patient should have 2 or more of the following: 6 or more café-au-lait spots of ≥ 1.5 cm in postpubertal individuals or ≥ 0.5 cm in prepubertal individuals; 2 or more neurofibromas of any type or 1 or more plexiform neurofibroma; and freckling in the underarms and groin.1 The differential diagnosis includes benign café-au-lait pigmentation (present in up to 10% of the general population), multiple lipomas, and sporadic schwannomas, gliomas and meningiomas in the central nervous system.Most people with mild neurofibromatosis have little disability. People affected by more severe variants have a shortened life expectancy, especially if tumours of the central nervous system or other malignant neoplasms arise during the course of illness.1,3 The condition can have a serious psychological impact because the accumulation of skin nodules can be quite disfiguring.5 Surgical excision and laser treatment of the neurofibromas are possible, but neither treatment is universally effective.6 Transplantation with an allograft of composite tissue on the lower and middle parts of a patient''s face was recently reported.7Gliomas of the optic nerve are found in up to 15% of pediatric patients with neurofibromatosis type 1. Best detected using magnetic resonance imaging, these gliomas are symptomatic in about 50% of patients at diagnosis. A minority will progress to vision loss.8 The high prevalence of gliomas of the optic nerve that are asymptomatic may, however, be biased by referral patterns, Indeed, in patients with neurofibromatosis type 1, the threshold of risk for optic nerve glioma is low.9Guidelines are available for the diagnosis and management of neurofibromatosis type 1.10,11 Physicians who identify patients with neurofibromatosis type 1 should refer them early to facilities where appropriate evaluation and monitoring of lesions can be carried out. Early detection and monitoring may help to prevent disability and death. 相似文献
Implementation of yellow fever vaccination is currently hampered by limited supply of vaccine. An alternative route of administration with reduced amounts of vaccine but without loss of vaccine efficacy would boost vaccination programmes.
Methods and Findings
A randomized, controlled, non-inferiority trial was conducted in a Dutch university center between August 2005 and February 2007. A total of 155 primary vaccinated and 20 previously vaccinated volunteers participated. Participants were randomly assigned in a 1∶1 ratio to receive intradermal (i.d.) vaccination with live attenuated yellow fever 17D vaccine at a reduced dose (1/5th; 0·1 mL) or the conventional subcutaneous (s.c.) vaccination (0·5 mL). Antibody neutralization titers were determined at 2, 4 and 8 weeks and 1 year after vaccination by counting the reduction in virus-induced plaques in the presence of serial serum dilutions. Adverse events were documented in a 3-week dairy. Viraemia was measured 5 days after vaccination. From 2 weeks up to one year after vaccination, the maximum serum-dilution at which 80% of the virus plaques were neutralized, which indicates protection against yellow fever, did not differ between those given a reduced i.d. dose or standard s.c. dose of vaccine. In all cases the WHO standard of seroprotection (i.e. 80% virus neutralization) was reached (in 77/77 and 78/78, respectively). Similar results were found in the previously vaccinated individuals. Viraemia was detected in half of the primary vaccinated participants, which was not predictive of serological response. In revaccinees no viraemia was detected.
Conclusions
Intradermal administration of one fifth of the amount of yellow fever vaccine administered subcutaneously results in protective seroimmunity in all volunteers. Albeit this vaccination route should enable vaccination of five-times as many individuals at risk for disease, these results should now be confirmed in field studies in areas with potential yellow fever virus transmission to change vaccination policy.
Here we describe a novel vaccine vector for expressing human immunodeficiency virus (HIV) antigens. We show that recombinant attenuated yellow fever vaccine virus 17D expressing simian immunodeficiency virus SIVmac239 Gag sequences can be used as a vector to generate SIV-specific CD8+ T-cell responses in the rhesus macaque. Priming with recombinant BCG expressing SIV antigens increased the frequency of these SIV-specific CD8+ T-cell responses after recombinant YF17D boosting. These recombinant YF17D-induced SIV-specific CD8+ T cells secreted several cytokines, were largely effector memory T cells, and suppressed viral replication in CD4+ T cells.None of the vaccine regimens tested in human immunodeficiency virus (HIV) vaccine efficacy trials to date have either reduced the rate of HIV infection or reduced the level of HIV replication. Structural features and the enormous variability of the envelope glycoprotein have frustrated efforts to induce broadly reactive neutralizing antibodies against HIV (10). Investigators have therefore focused their attention on T-cell-based vaccines (40). Simian immunodeficiency virus (SIV) challenge of rhesus macaques vaccinated with T-cell-based vaccines has shown that it is possible to control virus replication after SIV infection (22, 41, 42). The recent STEP trial of a recombinant Ad5-vectored vaccine was widely seen as an important test of this concept (http://www.hvtn.org/media/pr/step111307.html) (9, 25). Unfortunately, vaccinees became infected at higher rates than the controls (9). While it is still not clear what caused the enhanced infection rate in the vaccinated group, future Ad5-based human vaccine trials may be difficult to justify. We therefore need to develop new vaccine vectors for delivering SIV and HIV genes. Several other viral vectors currently under consideration include nonreplicating adenovirus (Ad)-based vectors (1, 21, 22), Venezuelan equine encephalitis (VEE) virus (12, 20), adeno-associated virus (AAV) (19), modified vaccinia virus Ankara (MVA) (3, 4, 13, 15, 18, 38), NYVAC (6), cytomegalovirus (CMV) (16), and replicating Ad (30). However, only a few of these have shown promise in monkey trials using rigorous SIV challenges.We explored whether the small (11-kb) yellow fever vaccine flavivirus 17D (YF17D) might be a suitable vector for HIV vaccines. The YF17D vaccine is inexpensive, production and quality control protocols already exist, and it disseminates widely in vivo after a single dose (27). Importantly, methods for the manipulation of the YF17D genome were recently established (7, 8, 24, 28). This effective vaccine has been safely used on >400 million people in the last 70 years (27). Additionally, the YF17D strain elicits robust CD8+ T-cell responses in humans (26). Chimeric YF17D is presently being developed as a vaccine for other flaviviruses, such as Japanese encephalitis virus (28), dengue virus (14), and West Nile virus (29). Inserts expressing a malaria B-cell epitope have been engineered into the E protein of YF17D (7). In murine models, recombinant YF17D viruses have generated robust and specific responses to engineered antigens inserted between the 2B and NS3 proteins in vivo (24, 35).We first used the YF17D vaccine virus to infect four Mamu-A*01-positive macaques. The vaccine virus replicated in these four animals and induced neutralizing antibodies in all four macaques by 2 weeks postvaccination (Fig. 1A and B). To monitor the CD8+ T-cell immune response against YF17D, we scanned its proteome for peptides that might bind to Mamu-A*01 using the major histocompatibility complex (MHC) pathway algorithm (31). We synthesized the 52 YF17D-derived peptides most likely to bind to Mamu-A*01 based on their predicted affinity for this MHC class I molecule. We then used a gamma interferon (IFN-γ) enzyme-linked immunospot (ELISPOT) assay to screen these peptides in YF17D-immunized animals at several time points after vaccination and discovered that four Mamu-A*01-binding peptides, LTPVTMAEV (LV91285-1293), VSPGNGWMI (VI93250-3258), MSPKGISRM (MM92179-2187), and TTPFGQQRVF (TF102853-2862), were recognized in vivo (Fig. (Fig.1C).1C). Using a previously reported protocol (26), we also observed CD8+ T-cell activation in all four animals (Fig. 1D and E). Thus, as was observed previously, the YF17D vaccine virus replicates in Indian rhesus monkeys (36) and induces neutralizing antibodies, yellow fever 17D-specific Mamu-A*01-restricted CD8+ T-cell responses, and CD8+ T-cell activation.Open in a separate windowFIG. 1.YF17D replicates and induces neutralizing antibodies, virus-specific CD8+ T cells, and the activation of CD8+ T cells in rhesus macaques. (A) Replication of YF17D during the first 10 days after vaccination with two different doses, as measured by quantitative PCR (Q-PCR) using the following primers: forward primer YF-17D 10188 (5′-GCGGATCACTGATTGGAATGAC-3′), reverse primer YF-17D 10264 (5′-CGTTCGGATACGATGGATGACTA-3′), and probe 6-carboxyfluorescein (6Fam)-5′-AATAGGGCCACCTGGGCCTCCC-3′-6-carboxytetramethylrhodamine (TamraQ). (B) Titer of neutralizing antibodies determined at 2 and 5 weeks after YF17D vaccination. (C) Fresh PBMC from vaccinees (100,000 cells/well) were used in IFN-γ ELISPOT assays (41) to assess T-cell responses against YF17D. We used 4 epitopes (LTPVTMAEV [LV91285-1293], VSPGNGWMI [VI93250-3258], MSPKGISRM [MM92179-2187], and TTPFGQQRVF [TF102853-2862]) predicted to bind to Mamu-A*01 as defined by the MHC pathway algorithm (31). All IFN-γ ELISPOT results were considered positive if they were ≥50 SFC/106 PBMC and ≥2 standard deviations over the background. (D) Identification of activated CD8+ T cells after vaccination with YF17D based on the expression of the proliferation and proapoptotic markers Ki-67 and Bcl-2, respectively (26). We stained whole blood cells with antibodies against CD3 and CD8. We then permeabilized and subsequently labeled these cells with Bcl-2- and Ki-67-specific antibodies. The flow graphs were gated on CD3+ CD8+ lymphocytes. (E) Expression kinetics of Ki-67 and Bcl-2 in CD8+ T cells after vaccination with YF17D.We next engineered the YF17D vaccine virus to express amino acids 45 to 269 of SIVmac239 Gag (rYF17D/SIVGag45-269) by inserting a yellow fever codon-optimized sequence between the genes encoding the viral proteins E and NS1. This recombinant virus replicated and induced neutralizing antibodies in mice (data not shown). We then tested the rYF17D/SIVGag45-269 construct in six Mamu-A*01-positive Indian rhesus macaques. We found evidence for the viral replication of rYF17D/SIVGag45-269 for five of these six macaques (Fig. (Fig.2A).2A). However, neutralizing antibodies were evident for all six animals at 2 weeks postvaccination (Fig. (Fig.2B).2B). Furthermore, all animals developed SIV-specific CD8+ T cells after a single immunization with rYF17D/SIVGag45-269 (Fig. (Fig.2C).2C). To test whether a second dose of this vaccine could boost virus-specific T-cell responses, we administered rYF17D/SIVGag45-269 (2.0 × 105 PFU) to four macaques on day 28 after the first immunization and monitored cellular immune responses. With the exception of animal r04091, the rYF17D/SIVGag45-269 boost did not increase the frequency of the vaccine-induced T-cell responses. This recombinant vaccine virus also induced CD8+ T-cell activation in the majority of the vaccinated animals (Fig. (Fig.2D2D).Open in a separate windowFIG. 2.rYF17D/SIVGag45-269 replicates and induces neutralizing antibodies, virus-specific CD8+ T cells, and the activation of CD8+ T cells in rhesus macaques. (A) Replication of rYF17D/SIVGag45-269 during the first 10 days after vaccination with two different doses as measured by Q-PCR using the YF17D-specific primers described in the legend of Fig. Fig.1.1. (B) Titer of neutralizing antibodies determined at 2 and 5 weeks after rYF17D/SIVGag45-269 vaccination. The low levels of neutralization for animal r02013 were observed in three separate assays. (C) Fresh PBMC from vaccinees (100,000 cells/well) were used in IFN-γ ELISPOT assays to assess T-cell responses against the YF17D vector (red) and the SIV Gag(45-269) insert (black) at several time points postvaccination. We measured YF17D-specific responses using the same epitopes described in the legend of Fig. Fig.1.1. For SIV Gag-specific responses, we used 6 pools of 15-mers overlapping by 11 amino acids spanning the entire length of the SIVmac239 Gag insert. In addition, we measured Mamu-A*01-restricted responses against the dominant Gag181-189CM9 and subdominant Gag254-262QI9 epitopes. Four animals received a second dose of rYF17D/SIVGag45-269 on day 28 after the first vaccination (dashed line). (D) Expression kinetics of Ki-67 and Bcl-2 in CD8+ T cells after vaccination with rYF17D/SIVGag45-269. This assay was performed as described in the legend of Fig. Fig.11.We could not detect differences in vaccine-induced immune responses between the group of animals vaccinated with YF17D and the group vaccinated with rYF17D/SIVGag45-269. There was, however, considerable animal-to-animal variability. Animal r02034, which was vaccinated with YF17D, exhibited massive CD8+ T-cell activation (a peak of 35% at day 14) (Fig. (Fig.1E),1E), which was probably induced by the high levels of viral replication (16,800 copies/ml at day 5) (Fig. (Fig.1A).1A). It was difficult to see differences between the neutralizing antibody responses induced by YF17D and those induced by rYF17D/SIVGag45-269 (Fig. (Fig.1B1B and and2B).2B). However, neutralizing antibodies in animal r02013 decreased by 5 weeks postvaccination. It was also difficult to detect differences in the YF17D-specific CD8+ T-cell responses induced by these two vaccines. Peak Mamu-A*01-restricted CD8+ T-cell responses against YF17D ranged from barely detectable (animal r02110 at day 11) (Fig. (Fig.1C)1C) to 265 spot-forming cells (SFCs)/106 peripheral blood mononuclear cells (PBMC) (animal r02034 at day 28) (Fig. (Fig.1C).1C). Similarly, three of the rYF17D/SIVGag45-269-vaccinated animals (animals r04091, r04051, and r02013) made low-frequency CD8+ T-cell responses against the Mamu-A*01-bound YF17D peptides, whereas the other three animals (animals r03130, r02049, and r02042) recognized these epitopes with responses ranging from 50 to 200 SFCs/106 PBMC (Fig. (Fig.2C).2C). For almost every rYF17D/SIVGag45-269-vaccinated animal, the Gag181-189CM9-specific responses (range, 50 to 750 SFCs/106 PBMC) were higher than those generated against the Mamu-A*01-restricted YF17D epitopes (range, 0 to 175 SFCs/106 PBMC), suggesting that the recombinant virus replicated stably in vivo (Fig. (Fig.2C).2C). Thus, the recombinant YF17D virus replicated and induced both virus-specific neutralizing antibodies and CD8+ T cells that were not demonstrably different from those induced by YF17D alone.Most viral vectors are usually more efficient after a prime with DNA or recombinant BCG (rBCG) (4, 11, 15, 18). We therefore used rYF17D/SIVGag45-269 to boost two macaques that had been primed with rBCG expressing SIV proteins (Fig. (Fig.3A).3A). We detected no SIV-specific responses after either of the two priming rBCG vaccinations. Unfortunately, while the recombinant YF17D virus replicated well in animal r01056, we found evidence for only low levels of replication of rYF17D/SIVGag45-269 on day 5 postvaccination for animal r01108 (7 copies/ml) (Fig. (Fig.3B).3B). Both animals, however, generated neutralizing antibodies at 2 weeks postvaccination (Fig. (Fig.3C).3C). Encouragingly, we detected high-frequency CD8+ T-cell responses in the Mamu-A*01-positive macaque (animal r01056) after boosting with rYF17D/SIVGag45-269 (Fig. 3D to F). These responses were directed mainly against the Mamu-A*01-restricted Gag181-189CM9 epitope, which is contained in the peptide pool Gag E (Fig. (Fig.3D).3D). Furthermore, the boost induced a massive activation of animal r01056''s CD8+ T cells, peaking at 35% at 17 days postvaccination (Fig. (Fig.3E).3E). Of these activated CD8+ T cells, approximately 10% were directed against the Gag181-189CM9 epitope, with a frequency of 3.5% of CD8+ T cells (Fig. (Fig.3E).3E). These epitope-specific CD8+ T cells made IFN-γ, tumor necrosis factor alpha (TNF-α), macrophage inflammatory protein 1β (MIP-1β), and degranulated (Fig. (Fig.3F3F and data not shown). Thus, an rBCG prime followed by a recombinant yellow fever 17D boost induced polyfunctional antigen-specific CD8+ T cells.Open in a separate windowFIG. 3.rYF17D/SIVGag45-269 vaccination induced a robust expansion of Gag-specific responses in an rBCG-primed macaque. (A) Vaccination scheme. We immunized two rhesus macaques with rBCG intradermally (i.d.) (2.0 × 105 CFU), rBCG orally (107 CFU), and rYF17D/SIVGag45-269 subcutaneously (2.0 × 105 PFU) at 6-month intervals. rBCG was engineered to express 18 minigenes containing sequences of Gag, Vif, Nef, Rev, and Tat from SIVmac239. (B) Replication of rYF17D/SIVGag45-269 during the first 10 days after vaccination as measured by Q-PCR using the YF17D-specific primers described in the legend of Fig. Fig.1.1. (C) Titer of neutralizing antibodies determined at 2 and 5 weeks after rYF17D/SIVGag45-269 vaccination. (D) Fresh PBMC from animal r01056 (100,000 cells/well) were used in IFN-γ ELISPOT assays to assess T-cell responses against the YF17D vector (red) and the SIV Gag(45-269) insert (black) at several time points postvaccination. (E) Kinetics of CD8+ T-cell activation (as described in the legend of Fig. Fig.1)1) and expansion of Gag181-189CM9-specific CD8+ T cells in animal r01056 after vaccination with rYF17D/SIVGag45-269. (F) Vaccination with rYF17D/SIVGag45-269 induced robust CD8+ T-cell responses against Gag181-189CM9 in r01056. CD8+ T-cell activation (Ki-67+/Bcl-2−) for baseline and day 13 are shown. Gag181-189CM9-specific responses were measured by tetramer staining and intracellular cytokine staining (ICS) with antibodies against MIP-1β and IFN-γ.Vaccine-induced CD8+ T cells are usually central memory T cells (TCM) or effector memory T cells (TEM). These two subsets of CD8+ T cells differ in function and surface markers (23). Repeated boosting drives CD8+ T cells toward the TEM subset (23). We therefore determined whether a rBCG prime followed by a rYF17D/SIVGag45-269 boost induced TCM or TEM CD8+ T cells. Staining of PBMC obtained on day 30 postvaccination revealed that the SIV-specific CD8+ T cells were largely TEM cells since the majority of them were CD28 negative (Fig. (Fig.4A).4A). Furthermore, these cells persisted with the same phenotype until day 60 after vaccination (Fig. (Fig.4B).4B). It was recently suggested that TEM cells residing in the mucosae can effectively control infection after a low-dose challenge with SIVmac239 (16).Open in a separate windowFIG. 4.rYF17D/SIVGag45-269 vaccination of animal r01056 induced effector memory Gag181-189CM9-specific CD8+ T cells that suppressed viral replication in CD4+ targets. (A and B) Frequency and memory phenotype of tetramer-positive Gag181-189-specific CD8+ T cells in animal r01056 on day 30 (A) and day 60 (B) after rYF17D/SIVGag45-269 vaccination. CD28 and CD95 expression profiles of tetramer-positive cells show a polarized effector memory phenotype. Cells were gated on CD3+ CD8+ lymphocytes. (C) Ex vivo Gag181-189CM9-specific CD8+ T cells from animal r01056 inhibit viral replication from SIVmac239-infected CD4+ T cells. Gag181-189CM9-specific CD8+ T cells from three SIV-infected Mamu-A*01-positive animals and rYF17D/SIVGag45-269-vaccinated animal r01056 were tested for their ability to suppress viral replication from SIV-infected CD4+ T cells (39). Forty-eight hours after the incubation of various ratios of SIV-infected CD4+ T cells and Gag181-189CM9-specific CD8+ T cells, the supernatant was removed and measured for viral RNA (vRNA) copies per ml by Q-PCR. We observed no suppression when effectors were incubated with CD4+ targets from Mamu-A*01-negative animals (data not shown). Animal rh2029 was infected with SIVmac239 (viral load, ∼105 vRNA copies/ml) containing mutations in 8 Mamu-B*08-restricted epitopes as part of another study (37). Animal r01080 was vaccinated with a DNA/Ad5 regimen expressing Gag, Rev, Tat, and Nef and later infected with SIVmac239 (viral load, ∼103 vRNA copies/ml) (42). Animal r95061 was vaccinated with a DNA/MVA regimen containing Gag181-189CM9 and was later challenged with SIVmac239 (undetectable viral load) (2).We then assessed whether rYF17D/SIVGag45-269-induced CD8+ T cells could recognize virally infected CD4+ T cells. We have shown that these vaccine-induced CD8+ T cells stain for tetramers and produce cytokines after stimulation with synthetic peptides (Fig. (Fig.3).3). None of these assays, however, tested whether these SIV-specific CD8+ T cells recognize SIV-infected cells and reduce viral replication. We therefore used a newly developed assay (39) to determine whether vaccine-induced CD8+ T cells can reduce viral replication in CD4+ T cells. We sorted tetramer-positive (Gag181-189CM9-specific) lymphocytes directly from fresh PBMC and incubated them for 48 h with SIVmac239-infected CD4+ T cells expressing Mamu-A*01. We assessed the percentage of CD4+ T cells that expressed SIV Gag p27 (data not shown) and the quantity of virus in the culture supernatant (Fig. (Fig.4C).4C). Vaccine-induced CD8+ T cells reduced viral replication to the same extent as that seen with Gag181-189CM9-specific CD8+ T cells purified from three SIVmac239-infected rhesus macaques, including an elite controller rhesus macaque, animal r95061 (Fig. (Fig.4C4C).The most encouraging aspect of this study is that rBCG primed a high-frequency CD8+ T-cell response after boosting with rYF17D/SIVGag45-269. These CD8+ T cells reached frequencies that were similar to those induced by an rBCG prime followed by an Ad5 boost (11). Even without the benefit of the rBCG prime, the levels of CD8+ T cells induced by a single rYF17D/SIVGag45-269 vaccination were equivalent to those induced by our best SIV vaccine, SIVmac239ΔNef. Recombinant YF17D generated an average of 195 SFCs/106 PBMC (range, 100 to 750 SFCs/106 PBMC) (n = 6), whereas SIVmac239ΔNef induced an average of 238 SFCs/106 PBMC (range, 150 to 320 SFCs/106 PBMC) (n = 3) (32). It is also possible that any YF17D/HIV recombinants would likely replicate better in humans than they have in rhesus macaques and thus induce more robust immune responses. Also, rBCG was shown previously to be effective in humans (5, 17, 33, 34) and may be more useful at priming T-cell responses in humans than it has been in our limited study with rhesus macaques. These two vectors have long-distinguished safety and efficacy histories in humans and may therefore be well suited for HIV vaccine development. 相似文献
Physicians face challenges when searching PubMed for research evidence, and they may miss relevant articles while retrieving too many nonrelevant articles. We investigated whether the use of search filters in PubMed improves searching by physicians.
Methods:
We asked a random sample of Canadian nephrologists to answer unique clinical questions derived from 100 systematic reviews of renal therapy. Physicians provided the search terms that they would type into PubMed to locate articles to answer these questions. We entered the physician-provided search terms into PubMed and applied two types of search filters alone or in combination: a methods-based filter designed to identify high-quality studies about treatment (clinical queries “therapy”) and a topic-based filter designed to identify studies with renal content. We evaluated the comprehensiveness (proportion of relevant articles found) and efficiency (ratio of relevant to nonrelevant articles) of the filtered and nonfiltered searches. Primary studies included in the systematic reviews served as the reference standard for relevant articles.
Results:
The average physician-provided search terms retrieved 46% of the relevant articles, while 6% of the retrieved articles were nonrelevant (the ratio of relevant to nonrelevant articles was 1:16). The use of both filters together produced a marked improvement in efficiency, resulting in a ratio of relevant to nonrelevant articles of 1:5 (16 percentage point improvement; 99% confidence interval 9% to 22%; p < 0.003) with no substantive change in comprehensiveness (44% of relevant articles found; p = 0.55).
Interpretation:
The use of PubMed search filters improves the efficiency of physician searches. Improved search performance may enhance the transfer of research into practice and improve patient care.Retrieving health literature is a cornerstone of evidence-based practice. With the rapid increase in available evidence, physicians can no longer rely on one or two key journals to stay current. Increasingly, physicians search bibliographic databases, such as PubMed, for research evidence, which is dispersed across hundreds of journals. Each year, physicians perform over 200 million searches in PubMed.1,2 Physicians face challenges while searching PubMed and often miss relevant articles while retrieving too many nonrelevant articles.3–6 Clinical decision-making based on evidence from a search may be impaired if relevant articles are missed. Retrieving many nonrelevant articles impedes the efficiency of searching. Improved search strategies are therefore necessary to retrieve a manageable amount of information. The use of PubMed search filters may help solve this problem. Filters are objectively derived, pretested strategies optimized to help users efficiently retrieve articles for a specific purpose.7,8PubMed provides two types of clinical search filters: methods-based and topic-based. Methods-based filters (known as clinical queries) were designed to retrieve articles on therapy, diagnosis, prognosis and etiology.9–13 For example, the clinical queries “therapy” filter is optimized to retrieve publications of randomized controlled trials. Methods-based filters can be used for any clinical discipline and are available for general use in PubMed (www.ncbi.nlm.nih.gov/pubmed/clinical). Topic-based filters, in contrast, are designed to retrieve articles within a specific discipline or topic. For example, the recently developed nephrology filters were optimized to retrieve articles with renal content.1Physicians can use methods- and topic-based filters alone or in combination. For example, Figure 1A shows a search without search filters for studies about the effectiveness of hepatitis B vaccination in patients with chronic kidney disease. Alternatively, this search could be performed with search filters (Figure 1B). Using filters removes the task of generating and including method-specific or topic-specific terms in a search strategy because the filters act as optimized substitutes. For example, applying the nephrology filter eliminates the need to enter renal terms and synonyms in a search query (e.g., chronic kidney disease, end-stage renal disease, chronic renal failure). The nephrology filter, instead, maximizes the retrieval of all renal content (see the nephrology filter strategy in Figure 1B).Open in a separate windowFigure 1:PubMed searches without (A) and with (B) filters. This figure was created from the PubMed clinical queries Web interface; this page currently does not feature a “clinical category” section. When we performed searches with the nephrology filter (B), we removed the term “chronic kidney disease” because the filter acts as an optimized substitute for clinical content terms.In theory, filters should make searching more efficient; however, empiric evidence of this among physicians is lacking. We conducted this study to determine whether the use of methods-based filters and topic-based filters (alone and in combination) improve the efficiency of physician searches in PubMed. The area of renal medicine is an excellent test model because the literature in this field is dispersed across 400 multidisciplinary journals, and many nephrologists search PubMed for information to guide patient care.14,15相似文献
Current requirements for control of live viral vaccines, including yellow fever 17D, produced from potentially neurotropic wild-type viruses include tests for neurovirulence in nonhuman primates. We have used yellow fever 17D virus as a live vector for novel flavivirus vaccines (designated ChimeriVax) against dengue, Japanese encephalitis (JE), and West Nile (WN) viruses. For control of these vaccines, it would be preferable to substitute a test in mice for the test in a higher species (monkeys). In this study, we compare the neurovirulence of ChimeriVax vaccine candidates in suckling mice inoculated by the intracerebral (IC) route with graded doses of the test article or yellow fever 17D vaccine as a reference control. Mortality ratio and survival distribution are the outcome measures. The monkey safety test is performed as described for control of yellow fever vaccines. In both mice and monkeys, all chimeric vaccines were significantly less neurovirulent than yellow fever 17D vaccine. The test in suckling mice discriminated between strains of two different vaccines (ChimeriVax-JE and ChimeriVax-DEN1) differing by a single amino acid change, and was more sensitive for detecting virulence differences than the test in monkeys. The results indicate that the suckling mouse test is simple to perform, highly sensitive and, with appropriate validation, could complement or possibly even replace the neurovirulence component of the monkey safety test. The test in infant mice is particularly useful as a means of demonstrating biological consistency across seed virus and vaccine lots. 相似文献
OXYMETAZOLINE IS A SYMPATHOMIMETIC amine found in over-the-counter nasal decongestants. We report a case of chronic use of nasal oxymetazoline associated with thunderclap headache due to reversible segmental intracranial vasoconstriction.A 31-year-old woman had sudden onset of global headache at 1 pm when she was resting that she characterized as the “worst of her life,” rating the pain as 10/10. Associated symptoms included nausea, vomiting, sonophobia and photophobia. The headache waxed and waned over the next 4 days, and on day 4 the patient presented to the emergency department in a community hospital. Her blood pressure, findings on neurological examination and initial CT scan were normal. Her past medical history included hiatal hernia, cigarette smoking and remote use of marijuana (she denied any other illicit drugs), and she was taking sertraline, peptobismol, lansoprazole and domperidone. A lumbar puncture revealed normal cerebrospinal fluid with no xanthochromia. The opening pressure in the seated position was 37 cm H2O. She was transferred to our hospital, and CT venography was performed. It revealed no venous sinus thrombosis, but multifocal vessel irregularities in both the anterior and posterior arterial circulations were observed. Cerebral angiography confirmed focal areas of vasospasm in the internal carotid circulations bilaterally as well as in the vertebrobasilar system (Fig. 1A, B, C). Results of hematologic and serologic investigations were negative for signs of systemic infection, inflammation or vasculitis.Open in a separate windowFig. 1: A: CT angiogram at admission showing axial reformatted images with severe narrowing of the M2 branches of the right middle cerebral artery. B: CT angiogram at admission showing midline sagittal multiplanar reformatted image; done to assess dural sinuses, the image shows multifocal narrowings of the anterior cerebral arteries. C: Right anterior oblique view from a selective cerebral angiogram of the right internal carotid artery showing focal narrowing and dilatation of anterior cerebral artery. D: Follow-up left anterior oblique view from the left carotid artery showing near complete resolution of arteriopathic changes.The patient had been using Afrin, a nasal spray that contains oxymetazoline, regularly for the previous 6 months. Although she was using the medication at recommended daily dosages (2–3 sprays twice daily), she was using it consistently. Two weeks before presentation she had noticed a pattern of headache starting 20 minutes after use of the nasal spray. The index event had occurred immediately after its use.Use of the nasal spray was discontinued. Narcotic analgesics reduced the pain, but the nausea and vomiting responded to ondansetron only. The patient had no improvement in her headache with nimodipine, a calcium-channel antagonist that causes dilatation of arterial smooth muscle. Repeat lumbar puncture was done in the supine position at discharge and demonstrated an opening pressure of 19 cm H2O. Two weeks after discharge the headache had nearly resolved. A repeat angiogram at 6 weeks showed complete resolution of most areas of arterial narrowing (Fig. 1D). 相似文献
Plants exploit several types of cell surface receptors for perception of extracellular signals, of which the extracellular leucine-rich repeat （eLRR）-containing receptors form the major class. Although the function of most plant eLRR receptors remains unclear, an increasing number of these receptors are shown to play roles in innate immunity and a wide variety of developmental processes. Recent efforts using domain swaps, gene shuffling analyses, site-directed mutagenesis, interaction studies, and crystallographic analyses resulted in the current knowledge on ligand binding and the mechanism of activation of plant eLRR receptors. This review provides an overview of eLRR receptor research, specificallysummarizing the recent understanding of interactions among plant eLRR receptors, their co-receptors and corresponding ligands. The functions of distinct eLRR receptor domains, and their role in structure, ligand perception and multimeric complex formation are discussed. 相似文献
The multicomponent serogroup B meningococcal (4CMenB) vaccine induces antibodies against indicator strains of serogroup B meningococcus under various schedules. We investigated the persistence of antibodies in 5-year-old children 18–20 months after their last dose (at about 3.5 years of age).
Methods:
We assessed 5-year-old children who received the 4CMenB vaccine or a recombinant protein vaccine in a previous randomized trial. We also recruited 50 vaccine-naive 5-year-olds and administered 2 doses of 4CMenB to each child. We measured serum bactericidal antibody titres against 4 indicator strains of serogroup B meningococcus matched to each individual vaccine component and against 4 mismatched strains.
Results:
Of those who received the 4CMenB vaccine at 2, 4, 6, 12 and 40 months (n = 16), the percentage with protective antibody titres (≥ 1:4) at 60 months ranged from 44% to 88% against matched strains and from 13% to 81% against mismatched strains. Loss of protective titres was also observed for those who received the 4CMenB vaccine at 12, 40 and 42 months (n = 5) (80%–100% against matched strains, 60%–100% against mismatched strains) or at 40 and 42 months (n = 29) (31%–100% against matched strains, 41%–81% against mismatched strains). Administering the 4CMenB vaccine to 5-year-old children yielded protective titres against matched strains in 92%–100% and against mismatched strains in 59%–100%. The majority of these children reported injection-site pain (40/50 [80%] after dose 1, 39/46 [85%] after dose 2) and erythema (47/50 [94%] and 40/46 [87%], respectively); rates of fever were low (5/50 [10%] and 2/46 [4%], respectively).
Interpretation:
Waning of immunity by 5 years of age occurred after receipt of the 4CMenB vaccine in infancy, even with an additional booster at 40 months. The 4CMenB vaccine is immunogenic and was fairly well tolerated by 5-year-old children, although injection-site pain was noteworthy. Trial registration:
ClinicalTrials.gov, no. {"type":"clinical-trial","attrs":{"text":"NCT01027351","term_id":"NCT01027351"}}NCT01027351The multicomponent serogroup B meningococcal (4CMenB) vaccine is licensed in the European Union, Australia and Canada to prevent serogroup B meningococcal disease. It was developed using “reverse vaccinology,” in which candidate antigens were identified by interrogating the whole meningococcal genome.1 The 4CMenB vaccine consists of 3 surface proteins (factor H binding protein [fHbp], Neisseria adhesin A [NadA] and Neisseria heparin-binding antigen [NHBA]), along with a fourth component, the outer membrane vesicle, which acts as both antigen and adjuvant.1Group B meningococcal disease is a potentially devastating condition, with an average case fatality rate of 5.2% (data for England and Wales2), and over a third of survivors are left with measurable functional deficits.3 The incidence of laboratory-confirmed cases is about 1 per 100 000 population in England4 and 0.33 per 100 000 population in Canada.5 The recommendation of the United Kingdom Joint Committee on Vaccination and Immunisation that the 4CMenB vaccine be introduced into the routine UK immunization schedule should, if implemented, lead to a reduction in this morbidity and mortality.6 Data on the persistence of antibody responses following infant or toddler immunization, and after subsequent boosting, remain limited yet will be important for guiding implementation of this recommendation.We present here the results of a follow-on study investigating the persistence of antibodies 18–20 months after the last dose in 5-year-old children previously immunized under a variety of schedules with 4CMenB vaccine or another investigational vaccine (recombinant protein serogroup B meningococcal [rMenB] vaccine), which lacks the outer membrane vesicle component of the 4CMenB vaccine. Since the original infant study,7 4CMenB vaccine has emerged as the preferred vaccine, because addition of the outer membrane vesicle component improves the breadth of strain coverage;8 however, the extension study continued follow-up for all of the original children, and all results are therefore presented here. 相似文献
Leucine-rich repeat receptor-like kinases （LRR-RLKs） belong to a large group of cell surface proteins involved in many aspects of plant development and environmental responses in both monocots and dicots. Brassinosteroid insensitive 1 （BRI1）, a member of the LRR X subfamily, was first identified through several forward genetic screenings for mutants insensitive to brassinosteroids （BRs）, which are a class of plant-specific steroid hormones. Since its identification, BRI1 and its homologs had been proved as receptors perceiving BRs and initiating BR signaling. The co-receptor BRIl-associated kinase 1 and its homologs, and other BRI1 interacting proteins such as its inhibitor BRI1 kinase inhibitor I （BKI1） were identified by genetic andbiochemical approaches. The detailed mechanisms of BR perception by BRI1 and the activation of BRI1 receptor complex have also been elucidated. Moreover, several mechanisms for termination of the activated BRI1 signaling were also discovered. In this review, we will focus on the recent advances on the mechanism of BRI1 phosphorylation and activation, the regulation of its receptor complex, the structure basis of BRI1 ectodomain and BR recognition, its direct substrates, and the termination of the activated BRI1 receptor complex. 相似文献
Raman spectral imaging is gaining more and more attention in biological studies because of its label‐free characteristic. However, the discrimination of overlapping chemical contrasts has been a major challenge. In this study, we introduce an optical method to simultaneously obtain two orthogonally polarized Raman images from a single scan of the sample. We demonstrate how this technique can improve the quality and quantity of the hyperspectral Raman dataset and how the technique is expected to further extend the horizons of Raman spectral imaging in biological studies by providing more detailed chemical information.
The dual‐polarization Raman images of a HeLa cell. 相似文献
The evolution of gold nanoparticle (Au NP) clusters in living cells are studied by using sectional dark‐field optical microscopy and chromatic analysis approach. During endocytosis, Au NP clusters undergo fantastic color changes, from green to yellow‐orange due to the plasmonic coupling effect. Analysis of brightness/hue values of the dark‐field images helps estimate the numbers of Au NPs in the clusters. The Au NP clusters were further categorized into four groups within the endocytosis. As the results, the late endosomes had increased number of large Au NP clusters with time, while clustered numbers in secondary and tertiary groups were first increased and then decreased due to the fusion and fission of the endocytic vesicles. The time constants and cluster numbers for different groups are fitted by using an integrated rate equation, and show a positive correlation with the size of the Au NP cluster. The efficiency of Au NP uptake is only about 50% for normal cells, while 75% for cancer cells. Compared to normal cells, cancer cells show a larger number in uptake, while faster rate in removal. The propose method helps the kinetic study of endocytosed nanoparticles in physiological conditions.
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