150 research outputs found

    Medical students’ preparedness for professional activities in early clerkships

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    Background Sufficient preparedness is important for transitions to workplace participation and learning in clinical settings. This study aims to analyse medical students’ preparedness for early clerkships using a three-dimensional, socio-cognitive, theory-based model of preparedness anchored in specific professional activities and their supervision level. Methods Medical students from a competency-based undergraduate curriculum were surveyed about preparedness for 21 professional activities and level of perceived supervision during their early clerkships via an online questionnaire. Preparedness was operationalized by the three dimensions of confidence to carry out clerkship activities, being prepared through university teaching and coping with failure by seeking support. Factors influencing preparedness and perceived stress as outcomes were analysed through step-wise regression. Results Professional activities carried out by the students (n = 147; 19.0%) and their supervision levels varied. While most students reported high confidence to perform the tasks, the activity-specific analysis revealed important gaps in preparation through university teaching. Students regularly searched for support in case of difficulty. One quarter of the variance of each preparedness dimension was explained by self-efficacy, supervision quality, amount of prior clerkship experience and nature of professional activities. Preparedness contributed to predicting perceived stress. Conclusions The applied three-dimensional concept of preparedness and the task-specific approach provided a detailed and meaningful view on medical students’ workplace participation and experiences in early clerkships

    Aptamer-based multiplexed proteomic technology for biomarker discovery

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    Interrogation of the human proteome in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology. We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 [mu]L of serum or plasma). Our current assay allows us to measure ~800 proteins with very low limits of detection (1 pM average), 7 logs of overall dynamic range, and 5% average coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding DNA aptamer concentration signature, which is then quantified with a DNA microarray. In essence, our assay takes advantage of the dual nature of aptamers as both folded binding entities with defined shapes and unique sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to discover unique protein signatures characteristic of various disease states. More generally, we describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine

    Evaluation of an influenza-like illness case definition in the diagnosis of influenza among patients with acute febrile illness in cambodia

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    <p>Abstract</p> <p>Background</p> <p>Influenza-like illness (ILI) is often defined as fever (>38.0°C) with cough or sore throat. In this study, we tested the sensitivity, specificity, and positive and negative predictive values of this case definition in a Cambodia patient population.</p> <p>Methods</p> <p>Passive clinic-based surveillance was established at nine healthcare centers to identify the causes of acute undifferentiated fever in patients aged two years and older seeking treatment. Fever was defined as tympanic membrane temperature >38°C lasting more than 24 hours and less than 10 days. Influenza virus infections were identified by polymerase chain reaction.</p> <p>Results</p> <p>From July 2008 to December 2008, 2,639 patients were enrolled. From 884 (33%) patients positive for influenza, 652 presented with ILI and 232 acute fever patients presented without ILI. Analysis by age group identified no significant differences between influenza positive patients from the two groups. Positive predictive values (PPVs) varied during the course of the influenza season and among age groups.</p> <p>Conclusion</p> <p>The ILI case definition can be used to identify a significant percentage of patients with influenza infection during the influenza season in Cambodia, assisting healthcare providers in its diagnosis and treatment. However, testing samples based on the criteria of fever alone increased our case detection by 34%.</p

    Safety Measures During Cholecystectomy: Results of a Nationwide Survey

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    BACKGROUND: This study aimed to identify safety measures practiced by Dutch surgeons during laparoscopic cholecystectomy. METHOD: An electronic questionnaire was sent to all members of the Dutch Society of Surgery with a registered e-mail address. RESULTS: The response rate was 40.4% and 453 responses were analyzed. The distribution of the respondents with regard to type of hospital was similar to that in the general population of Dutch surgeons. The critical view of safety (CVS) technique is used by 97.6% of the surgeons. It is documented by 92.6%, mostly in the operation report (80.0%), but often augmented by photography (42.7%) or video (30.2%). If the CVS is not obtained, 50.9% of surgeons convert to the open approach, 39.1% continue laparoscopically, and 10.0% perform additional imaging studies. Of Dutch surgeons, 53.2% never perform intraoperative cholangiography (IOC), 41.3% perform it incidentally, and only 2.6% perform it routinely. A total of 105 bile duct injuries (BDIs) were reported in 14,387 cholecystectomies (0.73%). The self-reported major BDI rate (involving the common bile duct) was 0.13%, but these figures need to be confirmed in other studies. CONCLUSION: The CVS approach in laparoscopic cholecystectomy is embraced by virtually all Dutch surgeons. The course of action when CVS is not obtained varies. IOC seems to be an endangered skill as over half the Dutch surgeons never perform it and the rest perform it only incidentally

    Resveratrol increases rate of apoptosis caused by purine analogues in malignant lymphocytes of chronic lymphocytic leukemia

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    In this study, we attempted to assess the interactions of resveratrol, a natural compound present in various plant species, with the purine analogues fludarabine and cladribine in terms of their effects on DNA damage and apoptosis in chronic lymphocytic leukemia (CLL) cells. The experiments were performed ex vivo using short-term cell cultures of blood and bone marrow cells from newly diagnosed untreated patients. We analyzed the expression of active caspase-3 and the BCL-2/BAX ratio as markers of apoptosis and the expression of phosphorylated histone H2AX (γH2AX) and activated ATM kinase, which are reporters of DNA damage. The results of our study revealed that resveratrol induced apoptosis in CLL cells in a tumor-specific manner but did not affect non-leukemic cells, and apoptosis was associated with a decreased BCL2/BAX ratio. Here, we report for the first time that both resveratrol + fludarabine and resveratrol + cladribine caused a higher rate of apoptosis in comparison to the rate caused by a single drug. The percentage of apoptotic cells induced by resveratrol alone was higher in the group of patients with better prognostic markers than in those with worse prognostic markers. However, the rates of apoptosis caused by resveratrol combined with purine analogues were independent of ZAP-70 and CD38 expression and the clinical state of the disease; they were only dependent on the presence of high-risk cytogenetic abnormalities. We also observed an increase in γH2AX expression together with a rise in activated ATM in most of the analyzed samples. The obtained results indicate that resveratrol might warrant further study as a new therapeutic option for CLL patients. This naturally occurring substance may be used as a single agent, especially in older persons for whom there are some limitations for the use of aggressive treatment. On the other hand, a lower purine analogue dose could potentially be used in combination with resveratrol because of their combined effect. One of the mechanisms of action of resveratrol is the induction of DNA damage, which ultimately leads to apoptosis

    Educational intervention improves anticoagulation control in atrial fibrillation patients:the TREAT randomised trial

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    Background: Stroke prevention in atrial fibrillation (AF), most commonly with warfarin, requires maintenance of a narrow therapeutic target (INR 2.0 to 3.0) and is often poorly controlled in practice. Poor patient-understanding surrounding AF and its’ treatment may contribute to patient’s willingness to adhere to recommendations. Method: A theory-driven intervention, developed using patient interviews and focus groups, consisting of a one-off group session (1-6 patients) utilising an ‘expert-patient’ focussed DVD, educational booklet, self-monitoring diary and worksheet, was compared in a randomised controlled trial (ISRCTN93952605) against usual care, with patient postal follow-ups at 1, 2, 6, and 12-months. Ninety-seven warfarin-naïve AF patients were randomised to intervention (n=46, mean age (SD) 72.0 (8.2), 67.4% men), or usual care (n=51, mean age (SD) 73.7 (8.1), 62.7% men), stratified by age, sex, and recruitment centre. Primary endpoint was time within therapeutic range (TTR); secondary endpoints included knowledge, quality of life, anxiety/depression, beliefs about medication, and illness perceptions. Main findings: Intervention patients had significantly higher TTR than usual care at 6-months (76.2% vs. 71.3%; p=0.035); at 12-months these differences were not significant (76.0% vs. 70.0%; p=0.44). Knowledge increased significantly across time (F (3, 47) = 6.4; p<0.01), but there were no differences between groups (F (1, 47) = 3.3; p = 0.07). At 6-months, knowledge scores predicted TTR (r=0.245; p=0.04). Patients’ scores on subscales representing their perception of the general harm and overuse of medication, as well as the perceived necessity of their AF specific medications predicted TTR at 6- and 12-months. Conclusions: A theory-driven educational intervention significantly improves TTR in AF patients initiating warfarin during the first 6-months. Adverse clinical outcomes may potentially be reduced by improving patients’ understanding of the necessity of warfarin and reducing their perception of treatment harm. Improving education provision for AF patients is essential to ensure efficacious and safe treatment

    A Contributing Role for Anti-Neuraminidase Antibodies on Immunity to Pandemic H1N1 2009 Influenza A Virus

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    Exposure to contemporary seasonal influenza A viruses affords partial immunity to pandemic H1N1 2009 influenza A virus (pH1N1) infection. The impact of antibodies to the neuraminidase (NA) of seasonal influenza A viruses to cross-immunity against pH1N1 infection is unknown.Antibodies to the NA of different seasonal H1N1 influenza strains were tested for cross-reactivity against A/California/04/09 (pH1N1). A panel of reverse genetic (rg) recombinant viruses was generated containing 7 genes of the H1N1 influenza strain A/Puerto Rico/08/34 (PR8) and the NA gene of either the pandemic H1N1 2009 strain (pH1N1) or one of the following contemporary seasonal H1N1 strains: A/Solomon/03/06 (rg Solomon) or A/Brisbane/59/07 (rg Brisbane). Convalescent sera collected from mice infected with recombinant viruses were measured for cross-reactive antibodies to pH1N1 via Hemagglutinin Inhibition (HI) or Enzyme-Linked Immunosorbent Assay (ELISA). The ectodomain of a recombinant NA protein from the pH1N1 strain (pNA-ecto) was expressed, purified and used in ELISA to measure cross-reactive antibodies. Analysis of sera from elderly humans immunized with trivalent split-inactivated influenza (TIV) seasonal vaccines prior to 2009 revealed considerable cross-reactivity to pNA-ecto. High titers of cross-reactive antibodies were detected in mice inoculated with either rg Solomon or rg Brisbane. Convalescent sera from mice inoculated with recombinant viruses were used to immunize naïve recipient Balb/c mice by passive transfer prior to challenge with pH1N1. Mice receiving rg California sera were better protected than animals receiving rg Solomon or rg Brisbane sera.The NA of contemporary seasonal H1N1 influenza strains induces a cross-reactive antibody response to pH1N1 that correlates with reduced lethality from pH1N1 challenge, albeit less efficiently than anti-pH1N1 NA antibodies. These findings demonstrate that seasonal NA antibodies contribute to but are not sufficient for cross-reactive immunity to pH1N1

    Chronic ventricular pacing in children: toward prevention of pacing-induced heart disease

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    In children with congenital or acquired complete atrioventricular (AV) block, ventricular pacing is indicated to increase heart rate. Ventricular pacing is highly beneficial in these patients, but an important side effect is that it induces abnormal electrical activation patterns. Traditionally, ventricular pacemaker leads are positioned at the right ventricle (RV). The dyssynchronous pattern of ventricular activation due to RV pacing is associated with an acute and chronic impairment of left ventricular (LV) function, structural remodeling of the LV, and increased risk of heart failure. Since the degree of pacing-induced dyssynchrony varies between the different pacing sites, ‘optimal-site pacing’ should aim at the prevention of mechanical dyssynchrony. Especially in children, generally paced from a very early age and having a perspective of life-long pacing, the preservation of cardiac function during chronic ventricular pacing should take high priority. In the perspective of the (patho)physiology of ventricular pacing and the importance of the sequence of activation, this paper provides an overview of the current knowledge regarding possible alternative sites for chronic ventricular pacing. Furthermore, clinical implications and practical concerns of the various pacing sites are discussed. The review concludes with recommendations for optimal-site pacing in children

    Dentifrices, mouthwashes, and remineralization/caries arrestment strategies

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    While our knowledge of the dental caries process and its prevention has greatly advanced over the past fifty years, it is fair to state that the management of this disease at the level of the individual patient remains largely empirical. Recommendations for fluoride use by patients at different levels of caries risk are mainly based on the adage that more is better. There is a general understanding that the fluoride compound, concentration, frequency of use, duration of exposure, and method of delivery can influence fluoride efficacy. Two important factors are (1) the initial interaction of relatively high concentrations of fluoride with the tooth surface and plaque during application and (2) the retention of fluoride in oral fluids after application
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