30 research outputs found
A master's exam in surgical training
AN EXAMPLE FOR THE PRESENT DAY: The current requirement for explicit quality standards and examination of surgeons is an opportunity to contemplate surgical training from a historical perspective by looking at the regulations of the Amsterdam Surgeons' Guild (1461-1736). At that time Amsterdam surgeons usually trained for five years in a master-apprentice relationship under the guidance of a master surgeon in a surgeon's shop. An important part of the surgical training took place in the botanical gardens and anatomical theatre, where, during the weekly lessons, the praelector anatomiae would also demonstrate anatomy on the bodies of the deceased. Surgical training was complete after the trainee had passed the 'meesterproef' (master's exam), in which the manufacturing of lancets, blood-letting and performing a trepanation on a skull played a major part. However, over the course of time the final master's exam as the ultimate test of capability at the end of surgical training has disappeared. From the perspective of renewed interest in explicit quality standards and examination of surgeons, the reintroduction of a modern master's exam should perhaps be considered.</p
Distribution of Cardioembolic Stroke: A Cohort Study
Background: A cardiac origin in ischemic stroke is more frequent than previously assumed, but it is not clear which patients benefit from cardiac work-up if obvious cardiac pathology is absent. We hypothesized that thromboembolic stroke with a cardiac source occurs more frequently in the posterior circulation compared with thromboembolic stroke of another etiology. Methods: We performed a multicenter observational study in 3,311 consecutive patients with ischemic stroke who were enrolled in an ongoing prospective stroke registry of 8 University hospitals between September 2009 and November 2014 in The Netherlands. In thi
Heterologous Expression and Maturation of an NADP-Dependent [NiFe]-Hydrogenase: A Key Enzyme in Biofuel Production
Hydrogen gas is a major biofuel and is metabolized by a wide range of microorganisms. Microbial hydrogen production is catalyzed by hydrogenase, an extremely complex, air-sensitive enzyme that utilizes a binuclear nickel-iron [NiFe] catalytic site. Production and engineering of recombinant [NiFe]-hydrogenases in a genetically-tractable organism, as with metalloprotein complexes in general, has met with limited success due to the elaborate maturation process that is required, primarily in the absence of oxygen, to assemble the catalytic center and functional enzyme. We report here the successful production in Escherichia coli of the recombinant form of a cytoplasmic, NADP-dependent hydrogenase from Pyrococcus furiosus, an anaerobic hyperthermophile. This was achieved using novel expression vectors for the co-expression of thirteen P. furiosus genes (four structural genes encoding the hydrogenase and nine encoding maturation proteins). Remarkably, the native E. coli maturation machinery will also generate a functional hydrogenase when provided with only the genes encoding the hydrogenase subunits and a single protease from P. furiosus. Another novel feature is that their expression was induced by anaerobic conditions, whereby E. coli was grown aerobically and production of recombinant hydrogenase was achieved by simply changing the gas feed from air to an inert gas (N2). The recombinant enzyme was purified and shown to be functionally similar to the native enzyme purified from P. furiosus. The methodology to generate this key hydrogen-producing enzyme has dramatic implications for the production of hydrogen and NADPH as vehicles for energy storage and transport, for engineering hydrogenase to optimize production and catalysis, as well as for the general production of complex, oxygen-sensitive metalloproteins
Intervju: akademik Jakša Barbić
Over the past 20 years evidence has accumulated confirming the immunomodulatory role of the appendix in ulcerative colitis (UC). This led to the idea that appendectomy might alter the clinical course of established UC. The objective of this body of research is to evaluate the short-term and medium-term efficacy of appendectomy to maintain remission in patients with UC, and to establish the acceptability and cost-effectiveness of the intervention compared to standard treatment. These paired phase III multicenter prospective randomised studies will include patients over 18 years of age with an established diagnosis of ulcerative colitis and a disease relapse within 12 months prior to randomisation. Patients need to have been medically treated until complete clinical (Mayo score <3) and endoscopic (Mayo score 0 or 1) remission. Patients will then be randomised 1:1 to a control group (maintenance 5-ASA treatment, no appendectomy) or elective laparoscopic appendectomy plus maintenance treatment. The primary outcome measure is the one year cumulative UC relapse rate - defined both clinically and endoscopically as a total Mayo-score ≥5 with endoscopic subscore of 2 or 3. Secondary outcomes that will be assessed include the number of relapses per patient at 12 months, the time to first relapse, health related quality of life and treatment costs, and number of colectomies in each arm. The ACCURE and ACCURE-UK trials will provide evidence on the role and acceptability of appendectomy in the treatment of ulcerative colitis and the effects of appendectomy on the disease course. NTR2883 ; ISRCTN5652301
Root-emitted volatile organic compounds: can they mediate belowground plant-plant interactions?
peer reviewedBackground
Aboveground, plants release volatile organic compounds (VOCs) that act as chemical
signals between neighbouring plants. It is now well documented that VOCs emitted by
the roots in the plant rhizosphere also play important ecological roles in the soil
ecosystem, notably in plant defence because they are involved in interactions between
plants, phytophagous pests and organisms of the third trophic level. The roles played
by root-emitted VOCs in between- and within-plant signalling, however, are still poorly
documented in the scientific literature.
Scope
Given that (1) plants release volatile cues mediating plant-plant interactions
aboveground, (2) roots can detect the chemical signals originating from their
neighbours, and (3) roots release VOCs involved in biotic interactions belowground,
the aim of this paper is to discuss the roles of VOCs in between- and within-plant
signalling belowground. We also highlight the technical challenges associated with the
analysis of root-emitted VOCs and the design of experiments targeting volatile-mediated
root-root interactions.
Conclusions
We conclude that root-root interactions mediated by volatile cues deserve more
research attention and that both the analytical tools and methods developed to study
the ecological roles played by VOCs in interplant signalling aboveground can be
adapted to focus on the roles played by root-emitted VOCs in between- and within-plant
signalling
De meesterproef in de chirurgijnsopleiding: Een historisch concept als voorbeeld voor nu?
AN EXAMPLE FOR THE PRESENT DAY: The current requirement for explicit quality standards and examination of surgeons is an opportunity to contemplate surgical training from a historical perspective by looking at the regulations of the Amsterdam Surgeons' Guild (1461-1736). At that time Amsterdam surgeons usually trained for five years in a master-apprentice relationship under the guidance of a master surgeon in a surgeon's shop. An important part of the surgical training took place in the botanical gardens and anatomical theatre, where, during the weekly lessons, the praelector anatomiae would also demonstrate anatomy on the bodies of the deceased. Surgical training was complete after the trainee had passed the 'meesterproef' (master's exam), in which the manufacturing of lancets, blood-letting and performing a trepanation on a skull played a major part. However, over the course of time the final master's exam as the ultimate test of capability at the end of surgical training has disappeared. From the perspective of renewed interest in explicit quality standards and examination of surgeons, the reintroduction of a modern master's exam should perhaps be considered
Residents' Engagement and Empathy Associated With Their Perception of Faculty's Teaching Performance
Faculty members rely on residents' feedback about their teaching performance. The influence of residents' characteristics on evaluations of faculty is relatively unexplored. We aimed to evaluate the levels of work engagement and empathy among residents and the association of both characteristics with their evaluation of the faculty's teaching performance. A multicenter questionnaire study among 271 surgery and gynecology residents was performed from September 2012 to February 2013. Residents' ratings of the faculty's teaching performance were collected using the system for evaluation of teaching quality (SETQ). Residents were also invited to fill out standardized measures of work engagement and empathy using the short Utrecht Work Engagement Scale and the Jefferson Scale of Physician Empathy, respectively. Linear regression analysis using generalized estimating equations to evaluate the association of residents' engagement and empathy with residents' evaluations of teaching performance. Overall, 204 (75.3 %) residents completed 1814 SETQ evaluations of 302 faculty, and 143 (52.8 %) and 140 (51.7 %) residents, respectively, completed the engagement and empathy measurements. The median scores of residents' engagement and empathy were 4.56 (scale 0-6) and 5.55 (scale 1-7), respectively. Higher levels of residents' engagement (regression coefficient b = 0.128; 95 % confidence interval (CI) 0.072-0.184; p <0.001) and empathy (b = 0.113; 95 % CI 0.063-0.164; p <0.001) were associated with higher faculty teaching performance scores. Residents' engagement and empathy appear to be positively associated with their evaluation of the faculty's performance. A possible explanation is that residents who are more engaged and can understand and share others' perspectives stimulate and experience faculty's teaching better than others