Biomedical subjects

S Klein

Publications and source records attributed to S Klein.

At least 19 recordsLinked to original sources

PubMed2007

Gene-gene effects on central processing of aversive stimuli.

Emotional reactivity and regulation are fundamental to human behavior. As inter-individual behavioral variation is affected by a multitude of different genes, there is intense interest to investigate gene-gene effects. Functional sequence variation at two genes has been associated with response and resiliency to emotionally unpleasant stimuli. These genes are the catechol-O-methyltransferase gene (COMT Val158Met) and the regulatory region (5-HTTLPR) of the serotonin transporter gene. Recently, it has been proposed that 5-HTT expression is not only affected by the common S/L variant of 5-HTTLPR but also by an A to G substitution. Using functional magnetic resonance imaging, we assessed the effects of COMT Val(158)Met and both 5-HTT genotypes on brain activation by standardized affective visual stimuli (unpleasant, pleasant, and neutral) in 48 healthy subjects. Based on previous studies, the analysis of genotype effects was restricted to limbic brain areas. To determine allele-dose effects, the number of COMT Met158 alleles (i.e., lower activity of COMT) and the number of 5-HTT low expressing alleles (S and G) was correlated with the blood oxygen level-dependent (BOLD) response to pleasant or unpleasant stimuli compared to neutral stimuli. We observed an additive effect of COMT and both 5-HTT polymorphisms, accounting for 40% of the inter-individual variance in the averaged BOLD response of amygdala, hippocampal and limbic cortical regions elicited by unpleasant stimuli. Effects of 5-HTT and COMT genotypes did not affect brain processing of pleasant stimuli. These data indicate that functional brain imaging may be used to assess the interaction of multiple genes on the function of neuronal networks.

Adult↗

PubMed2006

Personality characteristics in obesity and relationship with successful weight loss.

OBJECTIVE: Personality influences lifestyle behaviors. Therefore, certain personality traits could contribute to obesity and the response to behaviorally based weight loss therapy. PURPOSE: The aims of this study were to test the hypothesis that personality characteristics differ between lean and obese persons in the community, obese persons in the community and obese persons seeking weight loss therapy by enrolling in a comprehensive weight loss program, and in obese persons who were successful and unsuccessful in achieving behavioral therapy-induced weight loss. METHODS: The Temperament and Character Inventory was administered to 264 lean (body mass index (BMI) <25 kg/m(2)) and 56 obese (BMI> or =35 kg/m(2)) subjects from the St Louis community and 183 obese patients (BMI=44+/-10 kg/m(2)) enrolled in the Washington University Weight Management Program (WUWMP), which involved weekly group behavioral therapy and diet education sessions for 22 weeks. RESULTS: Compared with lean subjects, obese subjects in the community scored higher in novelty seeking (19.7+/-5.9 vs 16.2+/-6.0, P<0.05), lower in Persistence (4.1+/-1.8 vs 4.8+/-1.7, P<0.05) and lower in self-directedness (32.1+/-7.6 vs 34.3+/-6.6, P<0.05.) Patients enrolled in the WUWMP scored higher than obese persons in the general population in both Reward Dependence (17.1+/-4.2 vs 15.7+/-4.3, P<0.05) and cooperativeness (36.9+/-5.4 vs 34.5+/-6.2, P<0.05). Patients who were successful in losing weight (>10% weight loss) after 22 weeks of behavioral therapy scored lower in novelty seeking than those who were unsuccessful in losing weight (<5% weight loss) (17.6+/-5.9 vs 20.2+/-5.9, P<0.05). DISCUSSION: These results suggest that personality traits differ between lean and obese persons, and between obese persons who enroll and who do not enroll in a comprehensive weight management program. Moreover, high scores in novelty seeking are associated with decreased success in achieving behavioral therapy-induced weight loss.

Attitude to Health↗

PubMed2006

Novel expression and functional role of ghrelin in chicken ovary.

Ghrelin has recently emerged as pleiotropic regulator of a wide array of endocrine and non-endocrine functions. The former likely includes the control of gonadal function, as expression of ghrelin and its putative receptor, the GH secretagogue receptor type 1a (GHS-R1a), has been described in mammalian gonads, and direct effects of ghrelin in the control of testicular secretion and cell proliferation have been reported. Yet, the expression and/or functional role of ghrelin in gonads from non-mammalian species remain to be analyzed. The present study aimed to evaluate the expression of ghrelin and GHS-R genes in the chicken ovary, and to assess the potential involvement of ghrelin in the direct control of chick ovarian function. To this end, RT-PCR assays for ghrelin and GHS-R1a mRNAs were performed in ovarian tissue, and cultures of chicken ovarian cells were conducted in the presence of increasing doses (1, 10 or 100 ng/ml) of the ghrelin analog, ghrelin 1-18. Our results demonstrate that both ghrelin and GHS-R1a mRNAs are expressed in chick ovarian tissue. Moreover, challenge of ovarian granulosa cells with ghrelin 1-18 was able to induce markers of proliferation (i.e. expression of both PCNA and cyclin), and to modulate markers of apoptosis (i.e. decreased expression of caspase-3, bax, bcl-2 and TUNEL-positive cells). Moreover, ghrelin 1-18 increased the expression of PCNA, cyclin, bax and p53 in cultures of ovarian follicular fragments, where it also stimulated the release of progesterone, estradiol, arginine-vasotocin (AVT) and IGF-I, but not of testosterone. In conclusion, our study provides novel evidence for the gonadal expression of the genes encoding ghrelin and its cognate receptor in a non-mammalian species, i.e. the chicken ovary, and unravels the potential involvement of this newly discovered molecule in the control of key gonadal functions in the chick, such as proliferation, apoptosis, and hormone release.

Animals↗

PubMed2006

Genetic analysis of three different classification protocols for the evaluation of elbow dysplasia in German shepherd dogs.

OBJECTIVES: Three different scoring systems for elbow dysplasia and its radiographic signs were genetically evaluated in 2645 German shepherd dogs. METHODS: An animal model was used to estimate heritabilities and additive genetic and residual correlations for the three scoring systems: ED-SV, which is recommended by the International Elbow Working Group; ED-LA, developed by Lang and others; and ED-TH, proposed by Tellhelm. RESULTS: The effects of sex, age at examination and the correlation between the two factors were significant for all three scoring systems. Heritability estimates (se) were 0.18 (0.04) for ED-SV, 0.11 (0.03) for ED-LA and 0.16 (0.04) for ED-TH. The additive genetic correlations among the different single criteria for elbow dysplasia and the different elbow dysplasia scores were between 0.68 and 0.98, except for the criteria ununited anconeal process and osteochondrosis dissecans of the trochlea humeri, which were mostly genetically negatively correlated to the other radiological criteria. CLINICAL SIGNIFICANCE: The elbow dysplasia scores were determined by two genetically different traits. The possibilities for selecting German shepherd dogs with respect to elbow dysplasia might be improved by taking into account these two traits in the prediction of breeding values.

Age Factors↗

PubMed2005

[Perforator flaps--the evolution of a reconstructive surgical technique].

Trauma, oncological resections and pressure sores can cause major soft tissue defects. The evolution of cutaneous, myocutaneous, and fasciocutaneous flaps currently makes possible the restoration of contour and, in many cases, function. This evolution was closely related to the increased understanding of the vascular anatomy of the skin and subcutis and has led to the development of perforator flaps. A perforator flap is a large flap of skin that survives on a single vascular stalk that perforates the muscle, referred to in briefas a 'perforator'. This has its origin in a larger vascular stalk that runs beneath the muscle. The vascular stalk of such a perforator flap can be lengthened by dissecting the perforator from the muscle in continuity with the vessels running beneath the muscle. Moreover, the larger diameter of these vessels facilitates the creation of a vascular anastomosis in the receptor area. By the use of such perforator flaps, proper innervation and a good blood supply to the flap can be combined with less morbidity at the donor site. Important possibilities include the filling of a dorsal (decubitus) defect and breast reconstruction.

Humans↗

PubMed2005

Alterations in liver, muscle, and adipose tissue insulin sensitivity in men with HIV infection and dyslipidemia.

Dyslipidemia is common in patients with HIV infection. In this study, a two-stage euglycemic hyperinsulinemic clamp, with infusion of stable isotopically labeled tracers, was used to evaluate insulin action in skeletal muscle, liver, and adipose tissue in HIV-infected men with dyslipidemia (HIV-DL; plasma triglyceride >250 mg/dl and HDL <45 mg/dl; n=12), HIV-infected men without dyslipidemia (HIV w/o DL; n=12), and healthy men (n=6). Basal rates of glucose production (glucose R(a)), glucose disposal (glucose R(d)), and lipolysis (palmitate R(a)) were similar between groups. The relative suppression of glucose R(a) (63+/- 4, 77+/- 2, and 78+/- 3%, P=0.008) and palmitate R(a) (49+/-4, 63+/-3, and 68+/-3%, P=0.005) during ow-dose insulin infusion (plasma insulin approximately 30 microU/ml), and the relative stimulation of glucose R(d) (214+/-21, 390+/-25, and 393+/-46%, P=0.001) during high-dose insulin infusion (plasma insulin approximately 75 microU/ml) were lower in HIV-DL than in HIV w/o DL and healthy volunteers, respectively. Suppression of basal glucose R(a) correlated with plasma adiponectin (r=0.44, P=0.02) and inversely with plasma IL-6 (r=-0.49, P<0.001). Stimulation of glucose R(d) correlated directly with adiponectin (r=0.48, P<0.01) and inversely with IL-6 (r=-0.49, P=0.02). We conclude that dyslipidemia in HIV-infected men is indicative of multiorgan insulin resistance, and circulating adipokines may be important in the pathogenesis of impaired insulin action.

Adiponectin↗

PubMed2005

The nutritional phenotype in the age of metabolomics.

The concept of the nutritional phenotype is proposed as a defined and integrated set of genetic, proteomic, metabolomic, functional, and behavioral factors that, when measured, form the basis for assessment of human nutritional status. The nutritional phenotype integrates the effects of diet on disease/wellness and is the quantitative indication of the paths by which genes and environment exert their effects on health. Advances in technology and in fundamental biological knowledge make it possible to define and measure the nutritional phenotype accurately in a cross section of individuals with various states of health and disease. This growing base of data and knowledge could serve as a resource for all scientific disciplines involved in human health. Nutritional sciences should be a prime mover in making key decisions that include: what environmental inputs (in addition to diet) are needed; what genes/proteins/metabolites should be measured; what end-point phenotypes should be included; and what informatics tools are available to ask nutritionally relevant questions. Nutrition should be the major discipline establishing how the elements of the nutritional phenotype vary as a function of diet. Nutritional sciences should also be instrumental in linking the elements that are responsive to diet with the functional outcomes in organisms that derive from them. As the first step in this initiative, a prioritized list of genomic, proteomic, and metabolomic as well as functional and behavioral measures that defines a practically useful subset of the nutritional phenotype for use in clinical and epidemiological investigations must be developed. From this list, analytic platforms must then be identified that are capable of delivering highly quantitative data on these endpoints. This conceptualization of a nutritional phenotype provides a concrete form and substance to the recognized future of nutritional sciences as a field addressing diet, integrated metabolism, and health.

Diet↗

PubMed2005

Genetic evaluation of elbow angles as predictors of elbow dysplasia in German shepherd dogs.

Elbow angles were measured in X-rays of both elbows to elucidate the usefulness of such data for selecting against elbow dysplasia (ED) in German shepherd dogs. These measurements record the size, proportions and alignments of the anconeal process (PA), the radius (RA), the olecranon (OL), and the ulnar trochlear notch (UL). The reference system for evaluating the information content of the measurements was the score for ED (ED-SV) as recommended by the International Elbow Working Group. Data from 2645 X-rayed dogs born from 1998 to 2001 in 1331 kennels were analysed by using residual maximum likelihood procedures to estimate heritabilities, additive genetic correlations and residual correlations. The pedigree file included 11,426 dogs and contained ancestors for up to six generations. ED-SV was significantly influenced by sex, by age within sex and by month of birth. The elbow angles were significantly influenced by the month and year of birth, X-ray positioning of the dog's forelimbs, angle of elbow flection, litter size and number of dogs X-rayed by the veterinary practitioners. The following heritability estimates were found: h2=0.18+/-0.04 for ED; h2=0.76+/-0.04 for OL; h2=0.52+/-0.05 for PA; h2=0.50+/-0.04 for UL; and h2=0.39+/-0.04 for RA. The additive genetic correlations of ED-SV with three elbow angles (OL, UL and RA) were close to zero. A higher additive genetic correlation to ED-SV was found only for PA, for which r(g)=0.31. The distributions of predicted breeding values for susceptibility to ED were not affected by regarding the elbow angles as additional traits in the multivariate prediction procedure. Measurements of elbow angles were thus shown to be unsuitable for use in selection programmes against ED in German shepherd dogs.

Animals↗

PubMed2005

Completeness of malaria notification in the Netherlands 1995-2003 assessed by capture-recapture method.

In 1999 in the Netherlands, the duty to notify malaria was transferred from physicians to laboratories by the new Infectious Diseases Law. To evaluate the effect of this change, we aimed to estimate completeness of malaria notification in the Netherlands from 1995-2003. We calculated it relative to sentinel laboratory and hospital admission data. Using the two-source capture-recapture method (CRM), we estimated the total number of cases to assess the completeness relative to this number. The completeness of notification relative to sentinel data was 18.2 % (95% CI of 15.7-20.7) from 1995-1998 and 56.4 % (95% CI of 47.0-65.8) for 2000-2003. The completeness relative to the number of malaria cases admitted to the hospital was 35.1 % for the period 1995-2003. The estimated numbers of cases of malaria between 1995 and 1998 were 3123 (95% CI of 2796-3449) and 5043 (95% CI of 4343-5742) between 2000 and 2003. The completeness relative to this numbers changed from 35.5 % (95% CI of 32.1-39.7) in 1995-1998 to 36.1 % (95% CI of 31.7-41.9) for the years 2000-2003. Laboratory-based notification has significantly increased the absolute number of malaria notifications, but there was no change in completeness relative to hospital admissions. The increase in estimated malaria cases may be artificial, due to the extent of violation of CRM requirements over the study period.

Disease Notification↗

PubMed2004

Population structure and evolutionary origins of Microsporum canis, M. ferrugineum and M. audouinii.

The recurrent evolutionary emergence of asexual lineages within sexual zoo- and anthropophilic dermatophyte species living in animal-frequented soil is likely to be triggered by changes in ecological niche, i.e., shifts of host animal. Subsequent adaptation to the new host species is noted. Sometimes geographic isolation or intrinsic host factors like human race may also play a role in speciation. In the present study, we elaborate concepts of speciation in dermatophytes using the Microsporum canis complex as an example. The group consists of a cluster of phylogenetically closely related anamorphs: the anthropophilic taxa Microsporum audouinii and M. ferrugineum, and the zoophilic taxon M. canis. The sexually reproducing species underlying this complex is Arthroderma otae. The study is done by an analysis of the population structure of about 200 isolates and using intergenic spacers, non-translated regions of genes as well as hypervariable microsatellite markers that are known to evolve at high mutation rates. The results suggest that sympatric speciation took place already during the period where mating ability was maintained and thus that strictly clonal fungal species emerged in Africa and led to genetically isolated clonal species elsewhere.

Alleles↗

PubMed2004

Role of glutamate receptors in nucleus accumbens core and shell in spatial behaviour of rats.

The nucleus accumbens (NAC) is considered to be an important neural interface between corticolimbic and motor systems of the brain. Several studies have shown that the NAC is not only involved in motivation and reward-related processes but also in spatial behavior. We here investigated the involvement of different glutamate receptor subclasses within NAC core and shell subregions on behavior in a radial-maze. Rats were first trained in a four-arm-baited eight-arm radial maze task for baseline performance. Thereafter, the effects of microinjection of the nonselective glutamate receptor antagonist kynurenic acid (4.5 microg), the NMDA receptor antagonist 2-amino-5-phosphonopentanoic acid (1 microg) and the non-NMDA receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (0.75 microg) in NAC core and shell were tested on reference memory errors (RME) and working memory errors (WME). Moreover, the choice pattern of entries and duration of arm-entries were evaluated. Microinjection of all drugs increased RME. Additionally, non-NMDA receptor blockade in NAC shell but not core increased WME. After microinjection of all drugs into NAC core and shell rats preferentially choose the arms next to the previously visited arm. This work shows that glutamate receptors in both NAC subregions are important for spatial behavior. The deficits seen after glutamate receptor blockade may not be working- or reference memory-related but caused by a switch from a memory-dependent allocentric strategy to an egocentric response strategy.

2-Amino-5-phosphonovalerate↗

PubMed2004

Metabolomics in the opening decade of the 21st century: building the roads to individualized health.

It is rapidly becoming possible to measure hundreds or thousands of metabolites in small samples of biological fluids or tissues. This makes it possible to assess the metabolic component of nutritional phenotypes and will allow individualized dietary recommendations. ASNS has to take action to ensure that appropriate technologies are developed and that metabolic databases are constructed with the right inputs and organization. The relations between diet and metabolomic profiles and between those profiles and health and disease must be established. ASNS also should consider the social implications of these advances and plan for their appropriate utilization.

Animals↗

PubMed2004

Are health professionals getting caught in the crossfire? The personal implications of caring for trauma victims.

OBJECTIVES: To investigate the long term psychological sequelae of treating multiple victims of traumatic incidents, such as violent crime and motor vehicle accidents, and to assess staff exposure to violent patients in the emergency department. METHODS: A self administered questionnaire booklet was distributed to all full time and part time staff working within the Johannesburg Hospital Trauma Unit during September 2002. Participation was voluntary. The questionnaire was specifically designed for the study as no relevant, validated questionnaire was found to be suitable. Psychological assessment comprised two standardised measures, the impact of event scale-revised and the Maslach burnout inventory. RESULTS: Thirty eight staff members completed the questionnaire, a response rate of 90%. Over 40% of respondents had been physically assaulted while at work and over 90% had been verbally abused. Staff reported a significant level of post-traumatic symptoms, evaluated by the impact of event scale-revised (median = 17.5, range = 0-88), as a result of critical incidents they had been involved in during the previous six months. At least half of the respondents also reported a "high" degree of professional burnout in the three sub-scales of the Maslach burnout tnventory-that is emotional exhaustion, depersonalisation, and personal accomplishment. CONCLUSIONS: Preventative measures, such as increased availability of formal psychological support, should be considered by all trauma units to protect the long term emotional wellbeing of their staff.

Accidents, Traffic↗

PubMed2004

Severe hepatic injury in interleukin 18 (IL-18) transgenic mice: a key role for IL-18 in regulating hepatocyte apoptosis in vivo.

BACKGROUND: Interleukin 18 (IL-18) is a cytokine with pleiotropic activity that augments T helper 1 responses and cytotoxic activity of natural killer cells. METHODS: To assess the function of IL-18 in vivo, we generated IL-18 transgenic (IL-18 Tg) mice under the control of a CD2 promoter/enhancer construct. RESULTS: Macroscopically, IL-18 Tg mice showed reduced relative liver weight compared with wild-type littermates. TUNEL assays demonstrated increased hepatocyte apoptosis, and primary hepatocytes isolated from IL-18 Tg mice exhibited an increased spontaneous apoptosis rate. Furthermore, cross linking of Fas increased significantly the apoptosis rate in hepatocytes isolated from wild- type mice but to a much lesser extent in IL-18 Tg mice, suggesting spontaneous activation of the Fas pathway in the latter mice. In fact, in vivo blockade of Fas signal transduction by an adenovirus overexpressing the dominant negative form of the Fas associated death domain rescued hepatocytes from undergoing apoptosis. Finally, adoptive transfer of CD4(+) T cells from IL-18 Tg mice but not from wild-type littermates in SCID mice resulted in severe liver failure with massive periportal fibrosis due to hepatocyte apoptosis. CONCLUSION: IL-18 plays a fundamental role in regulating hepatocyte apoptosis. Furthermore, our transgenic model provides a novel tool to study the mechanisms of IL-18 dependent liver injury in vivo.

Adoptive Transfer↗

PubMed2003

Tibial fixation comparison of semitendinosus-bone composite allografts fixed with bioabsorbable screws and bone-patella tendon-bone grafts fixed with titanium screws.

Tibial fixation remains the weak link of ACL reconstruction over the first 8-12 weeks postoperatively. This study compared the biomechanical properties of tibial fixation for a bone-patellar tendon-bone (BPTB) graft and a novel semitendinosus-bone composite (SBC) allograft with mixed cortical-cancellous bone dowels at each end. Seven paired, fresh frozen cadaveric knees (20-45 years) were stripped of all soft tissue attachments and randomly assigned to receive either the BPTB graft or SBC allograft. Grafts were placed into tibial tunnels via a standard protocol and secured with either a 10 mmx28 mm bioabsorbable (SBC) or titanium (BPTB) screw. Grafts were cycled ten times in a servo hydraulic device from 10-50 N prior to pull to failure testing at a rate of 20 mm/min with the force vector aligned with the tibial tunnel ("worst case scenario"). Wilcoxon Signed Rank Tests were used to evaluate biomechanical differences between graft types ( p<0.05). Tibial bone mineral density and interference screw insertion torque were statistically equivalent between graft types. The mode of failure for all constructs was direct screw and graft construct pullout from the tibial tunnel. Significant differences were not observed between graft types for maximum load at failure strength (BPTB=620.8+/-209 N vs. SBC=601.2+/-140 N, p=0.74) or stiffness (BPTB=69.8 N/mm+/-29 N/mm vs SBC=47.1+/-31.6 N/mm, p=0.24). The SBC allograft yielded significantly more displacement prior to failure than the BPTB graft (15.1+/-4.9 mm vs 9.2+/-1.3 mm, p=0.04). Increased construct displacement appeared to be due to fixation failure, with some evidence of graft tissue tearing around the sutures: Bioabsorbable screw (10 x 28 mm) fixation of the SBC allograft produced unacceptable displacement levels during testing. Further study is recommended using a titanium interference screw or a longer bioabsorbable screw for SBC graft fixation under cyclic loading conditions.

Absorbable Implants↗

PubMed2003

Alterations in lipid kinetics in men with HIV-dyslipidemia.

Hypertriglyceridemia is common in individuals with human immunodeficiency (HIV) infection, but the mechanisms responsible for increased plasma triglyceride (TG) concentrations are not clear. We evaluated fatty acid and VLDL-TG kinetics during basal conditions and during a glucose infusion that resulted in typical postprandial plasma glucose and insulin concentrations in six men with HIV-dyslipidemia [body mass index (BMI): 28 +/- 2 kg/m2] and six healthy men (BMI: 26 +/- 2 kg/m2). VLDL-TG secretion and palmitate rate of appearance (Ra) in plasma were measured by using stable-isotope-labeled tracer techniques. Basal palmitate Ra and VLDL-TG secretion rates were greater (P < 0.01 for both) in men with HIV-dyslipidemia (1.04 +/- 0.07 micromol palmitate x kg-1 x min-1 and 5.7 +/- 0.6 micromol VLDL-TG x l plasma-1 x min-1) than in healthy men (0.67 +/- 0.08 micromol palmitate. kg-1 x min-1 and 3.0 +/- 0.5 micromol VLDL-TG x l plasma-1 x min-1). Basal VLDL-TG plasma clearance was lower in men with HIV-dyslipidemia (13 +/- 1 ml/min) than in healthy men (19 +/- 2 ml/min; P < 0.05). Glucose infusion decreased palmitate Ra (by approximately 50%) and the VLDL-TG secretion rate (by approximately 30%) in both groups, but the VLDL-TG secretion rate remained higher (P < 0.05) in subjects with HIV-dyslipidemia. These findings demonstrate that increased secretion of VLDL-TG and decreased plasma VLDL-TG clearance, during both fasting and fed conditions, contribute to hypertriglyceridemia in men with HIV-dyslipidemia. Although it is likely that increased free fatty acid release from adipose tissue contributes to the increase in basal VLDL-TG concentration, other factors must be involved, because insulin-induced suppression of lipolysis and systemic fatty acid availability did not normalize the VLDL-TG secretion rate.

Adult↗

PubMed2003

Production of N-acylhomoserine lactone signal molecules by gram-negative soil-borne and plant-associated bacteria.

Quorum-sensing control mediated by N-acylhomoserine lactone (AHL) signal molecules has been established as a key feature in the regulation of various metabolic traits in many bacteria. Approximately 300 strains representing 6 genera and 18 species of soil-borne and plant-associated Gram-negative bacteria isolated in various regions of the former USSR using two reporter systems were screened for AHL production. The production was observed in 17.5% of the screened bacterial strains. Positive response was detected in all of the 14 tested strains of Erwinia herbicola, in 41 of the 239 strains of Pseudomonas species; in all 5 strains of Xanthomonas ampelina, X. campestris pv. malvacearum, pv. translucens, pv. vesicatoria and in one strain of Pantoea stewartii. AHL assay of 41 strains of X. maltophilia (syn. Stenotrophomonas maltophilia) isolated from soils with Chromobacterium violaceum reporter has revealed no strains synthesizing these signal molecules; 26 strains analyzed with Agrobacterium tumefaciens reporter showed the same result.

4-Butyrolactone↗

PubMed2003

Assessing the communication skills of doctors in training: reliability and sources of error.

Medical examining bodies now commonly assess candidates' communication skills. However, there are a number of within-case sources of error that can mean examinations have poor reliability and validity. The aims of this study were to determine the main within-case sources of error and to identify the best methods of maximising reliability in highly structured communication skills assessments. Subjects were fifth year medical students at the University of Aberdeen. Subjects were videotaped giving clinical information to standardised patients and relatives toward the end of their fifth year and toward the end of their pre-registration year. Sources of variation, reliability coefficients and the most effective methods of reducing measurement error were calculated using generalisability theory. Systematic differences among subjects' communication skill was the main source of variation in two of the three assessment cases. The implications of the results are discussed.

Communication↗