U.S. medical resident familiarity with national tuberculosis guidelines

Background  

The ability of medical residents training at U.S. urban medical centers to diagnose and manage tuberculosis cases has important public health implications. We assessed medical resident knowledge about tuberculosis diagnosis and early management based on American Thoracic Society guidelines.     

Predicting type 1 diabetes

Predicting type 1 diabetes mellitus (T1DM) is a prerequisite for disease prevention. Prediction is currently performed on three levels, which include the genetic susceptibility for disease, the identification of preclinical T1DM by way of circulating islet autoantibodies, and the use of metabolic tests to stage preclinical disease into late or early prediabetes. Combinations of genetic markers such as HLA genotype, INS genotype, and if and how much family history of T1DM is present can stratify disease risk more than 1000-fold, and can be used for selection of first-degree relatives of patients with T1DM for primary intervention trials. Measurement of autoantibodies in genetically at-risk subjects identifies future cases of T1DM. Further stratification of diabetes risk in autoantibody-positive subjects can be made on the basis of autoantibody characteristics that correspond to the magnitude of the autoantibody response.     

Molecular remodeling in the failing human heart

Heart failure is a progressive and fatal disease process. Arrhythmias and progressive cardiac dysfunction account for most of the morbidity and mortality in patients with heart failure. In general, the physiologic mechanisms responsible for progressive myocyte dysfunction, remodeling, and arrhythmias involve signaling mechanisms that alter myocardial gene expression. These changes in gene expression are complex and involve contractile proteins, ion channels, Ca++ handling, apoptosis, cell metabolism, the extracellular matrix, signal transduction pathways, and growth factors.     

HAART drugs induce mitochondrial damage and intercellular gaps and gp 120 causes apoptosis

HIV-1 infection is associated with serious cardiovascular complications, but the roles of HIV-1, viral proteins, and highly active antiretroviral therapy (HAART) drugs are not understood. HAART decreases the overall risk of heart disease but leads to metabolic disturbances and possibly coronary artery disease. We investigated toxicities of HIV-1, HIV-1 glycoprotein 120 (gp120), and HAART drugs for human coronary artery endothelial cells (CAECs), brain microvascular endothelial cells, and neonatal rat ventricular myocytes (NRVMs). HIV-1 and gp120, but not azidothymidine (AZT), induced apoptosis of NRVMs and CAECs. Ethylisothiourea, an inhibitor of nitric oxide synthase, inhibited apoptosis induction by gp120. AZT, HIV-1, and gp120 all damaged mitochondria of cardiomyocytes. HAART drugs, AZT, and indinavir, but not HIV-1, produced intercellular gaps between confluent endothelial cells and decreased transendothelial electrical resistance. In conclusion, HIV-1 and gp120 induce toxicity through induction of cardiomyocyte and endothelial cell apoptosis. HAART drugs disrupt endothelial cell junctions and mitochondria and could cause vascular damage.     

Matrix Metalloproteinases in the Pathogenesis of Asthma and COPD

While asthma is an inflammatory disorder of the airways involving mediators released from mast cells and eosinophils, inflammation alone is insufficient to explain the chronic nature of the disease. Recent progress in the understanding of disease pathogenesis has revealed that airway remodeling, which is at least in part due to an excess of extracellular matrix (ECM) deposition in the airway wall, plays a significant role in airflow obstruction. Matrix metalloproteinases (MMPs) have been suggested to be the major proteolytic enzymes to induce airway remodeling in asthma and COPD. It has been widely accepted that different inflammatory processes are involved in asthma and COPD with different inflammatory cells, mediators, and responses to treatments. Despite these different processes, airflow obstruction and airway remodeling characterize these two diseases. MMP-2 and -9 have been reported to be involved in the pathogenesis of airway remodeling in both diseases and MMP-12, in addition to these MMPs, in the pathogenesis of COPD. In this review, we discuss the current views on the role of MMPs in the pathogenesis of bronchial asthma and COPD. Anti-MMP therapy could theoretically be useful to prevent airway remodeling in asthma and COPD. However, to date no clinical data are available regarding the efficacy of anti-MMP therapies in the treatment of patients with asthma and COPD.     

Performance of a Web-Based Clinical Diagnosis Support System for Internists

BACKGROUND Rigorous guideline development methods are designed to produce recommendations that are relevant to common clinical situations and consistent with evidence and expert understanding, thereby promoting guidelines’ acceptability to providers. No studies have examined whether this technical quality consistently leads to acceptability. OBJECTIVE To examine the clinical acceptability of guidelines having excellent technical quality. DESIGN AND MEASUREMENTS We selected guidelines covering several musculoskeletal disorders and meeting 5 basic technical quality criteria, then used the widely accepted AGREE Instrument to evaluate technical quality. Adapting an established modified Delphi method, we assembled a multidisciplinary panel of providers recommended by their specialty societies as leaders in the field. Panelists rated acceptability, including “perceived comprehensiveness” (perceived relevance to common clinical situations) and “perceived validity” (consistency with their understanding of existing evidence and opinions), for ten common condition/therapy pairs pertaining to Surgery, physical therapy, and chiropractic manipulation for lumbar spine, shoulder, and carpal tunnel disorders. RESULTS Five guidelines met selection criteria. Their AGREE scores were generally high indicating excellent technical quality. However, panelists found 4 guidelines to be only moderately comprehensive and valid, and a fifth guideline to be invalid overall. Of the topics covered by each guideline, panelists rated 50% to 69% as “comprehensive” and 6% to 50% as “valid”. CONCLUSION Despite very rigorous development methods compared with guidelines assessed in prior studies, experts felt that these guidelines omitted common clinical situations and contained much content of uncertain validity. Guideline acceptability should be independently and formally evaluated before dissemination. This document includes content previously published in a RAND report, available online at: .     

The Constipation Severity Instrument: A Validated Measure

Purpose This study was designed to develop and test the validity and reliability of the Constipation Severity Instrument. Methods Scale development was conducted in two stages: 1) 74 items were generated through a literature review and focus groups of constipated patients and medical providers; and 2) a preliminary instrument was administered to 191 constipated patients and 103 healthy volunteers. Test-retest reliability of the constipated group was assessed (N = 90). Content, convergent, divergent, and discriminant validity were evaluated by using other validated measures by performing one-way analysis of variance and Pearson correlations. Results Exploratory and confirmatory factor analysis revealed three subscales: obstructive defecation, colonic inertia, and pain. Internal consistency (α = 0.88–0.91) and test-retest reliability (intraclass correlation coefficients = 0.84–0.91) were high for all subscales. Constipated patients were grouped by Rome II criteria: functional constipation (22 percent), pelvic floor dyssynergia (15 percent), constipation predominant irritable bowel syndrome (23 percent), and no specific criteria (40 percent). Those with constipation predominant irritable bowel syndrome or pelvic floor dyssynergia scored higher on the Obstructive Defecation and Colonic Inertia subscales than those with functional constipation or no specific criteria (P = 0.001–0.058). Subjects with functional constipation had much lower scores on the pain subscale than constipation predominant irritable bowel syndrome, functional constipation, or no specific criteria (P < 0.009).The Constipation Severity Instrument subscale and total score correlated very highly with the subscales and total score of the Patient Assessment of Constipation Symptom measure. The Constipation Severity Instrument subscales discriminated well between constipated patients and healthy volunteers (P < 0.001) and demonstrated excellent divergent validity. Higher Constipation Severity Instrument scores inversely correlated with general quality of life. Conclusions The Constipation Severity Instrument is a reliable and valid instrument for assessing constipated patients. Administration of the Constipation Severity Instrument to other constipated patients will further validate its use. Supported by the University of California San Francisco Hellman Family Award for Early Career Faculty. Read at the meeting of The American Society of Colon and Rectal Surgeons, St. Louis, Missouri, June 2 to 6, 2007. Reprints are not available.     

The effects of coronary artery disease severity on time-dependent changes in platelet activation indices in stored whole blood

Background Platelets play a pivotal role in the pathogenesis of the thrombotic complications in cardiovascular disease (CVD). Abnormal platelet activation indices are evolving as potentially useful markers in CVD risk stratification. Whilst there has been some investigation into the effects of storage time on several of these indices, the effects of underlying disease severity on these temporal changes have not been previously studied. Methods Using the ADVIA^TM120 haematology analyser, we assessed the effects of time-dependent storage of whole blood in EDTA, on a number of platelet activation indices: mean platelet volume (MPV), mean platelet component (MPC, measure of platelet density) and platelet component distribution width (PCDW, a marker of platelet shape change. We studied three age- and sex-matched patient groups: (i) healthy controls (n = 10), (ii) stable patients with coronary artery disease (CAD, n = 9); and (iii) patients with acute myocardial infarction (n = 8). Whole blood samples were processed at exactly 5 min following venesection and at 15, 30, 60 and 120 min later in storage in EDTA tubes at room temperature. Results There was a significant and stepwise increase in MPV (P = 0.01) and decrease in PCDW (P = 0.03), with a non-significant trend to increasing MPM and decreasing MPC with increasing underlying disease (that is healthy, ‘stable’ and ‘acute’ artery disease). There was a significant time-dependent increase in MPV and decrease in MPC and PCDW (all P < 0.05), which were all significant on ‘post-hoc’ analyses by 30 min. There were no significant changes in platelet count or MPM with time. There was no interaction of underlying disease with whole-blood storage time for any of the platelet indices reported (P = NS). Conclusion There is a temporal increase in MPV and decrease in MPC and PCDW in venous blood stored over 2 h in EDTA. These changes are not influenced by the underlying CVD disease severity.     

Incidence,consequences, and risk factors for anastomotic dehiscence after colorectal surgery: a prospective monocentric study

Background Anastomotic dehiscence is the most severe surgical complication after large bowel resection. This study was designed to assess the incidence, to observe the consequences, and to identify the risk factors associated with anastomotic leakage after colorectal surgery. Materials and methods All procedures involving anastomoses of the colon or the rectum, which were performed between November 2002 and February 2006 in a single institution, were prospectively entered into a computerized database. Results One thousand eighteen colorectal resections and 811 anastomoses were performed over this 40-month period. The most frequent procedures were sigmoid (276) and right colectomies (217). The overall anastomotic leak rate was 3.8%. The mortality rate associated with anastomotic leak was 12.9%. In univariate analysis, the following parameters were associated with an increased risk for anastomotic dehiscence: (1) ASA score ≥ 3 (p = 0.004), (2) prolonged (>3 h) operative time (p = 0.02), (3) rectal location of the disease (p < 0.001), (4) and a body mass index > 25 (p = 0.04). In multivariate analysis, ASA score ≥ 3 (OR = 2.5; 95% CI 1.5–4.3, p < 0.001), operative time > 3 h [OR = 3.0; 95% CI 1.1–8.0, p = 0.02), and rectal location of the disease (OR = 3.75; 95% CI 1.5–9.0 (vs left colon), p = 0.003; OR = 7.69; 95% CI 2.2–27.3 (vs right colon), p = 0.001] were factors significantly associated with a higher risk of anastomotic dehiscence. Conclusions Three risk factors for anastomotic leak have been identified, one is patient-related (ASA score), one is disease-related (rectal location), the third being surgery-related (prolonged operative time). These factors should be considered in perioperative decision-making regarding defunctioning stoma formation.     

Evaluation of a Longitudinal Medical School Evidence-Based Medicine Curriculum: A Pilot Study

Background  Evidence-based medicine (EBM) is increasingly taught in medical schools, but few curricula have been evaluated using validated instruments. Objective  To evaluate a longitudinal medical school EBM curriculum using a validated instrument. Design, Participants, Measurements  We evaluated EBM attitudes and knowledge of 32 medical students as they progressed through an EBM curriculum. The first part was an EBM “short course” with didactic and small-group sessions occurring at the end of the second year. The second part integrated EBM assignments with third-year clinical rotations. The validated 15-item Berlin Questionnaire was administered before the course, after the short course, and at the end of the third year. Results  EBM knowledge scores increased from baseline by 2.8 points at the end of the second year portion of the course (p = .0001), and by 3.7 points at the end of the third year (p < .0001). Self-rated EBM knowledge increased from baseline by 0.8 and 1.1 points, respectively (p = .0006 and p < .0001, respectively). EBM was felt to be of high importance for medical education and clinical practice at all time points, peaking after the short course. Conclusions  A longitudinal medical school EBM curriculum was associated with increased EBM knowledge. This knowledge increase was sustained throughout the curriculum. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.