Trichloroethylene inhibits development of embryonic heart valve precursors in vitro.

Previous epidemiological studies with humans and laboratory studies with chickens and rats linked trichloroethylene (TCE) exposure to cardiac defects. Although the cardiac defects in humans and laboratory animals produced by TCE are diverse, a majority of them involves valvular and septal structures. Progenitors of the valves and septa are formed by an epithelial-mesenchymal cell transformation of endothelial cells in the atrioventricular (AV) canal and outflow tract areas of the heart. Based on these studies, we hypothesized that TCE might cause cardiac valve and septa defects by specifically perturbing epithelial-mesenchymal cell transformation. We tested this hypothesis using an in vitro chick-AV canal culture model. This study shows that TCE affected several elements of epithelial-mesenchymal cell transformation. In particular, TCE blocked the endothelial cell-cell separation process that is associated with endothelial activation. Moreover, TCE inhibited mesenchymal cell formation throughout the concentration range tested (50-250 ppm). In contrast, TCE had no effect on the cell migration rate of the fully formed mesenchymal cells. Finally, the expression of 3 proteins (selected as molecular markers of epithelial-mesenchymal cell transformation) was analyzed in untreated and TCE-treated cultures. TCE inhibited the expression of the transcription factor Mox-1 and extracellular matrix (ECM) protein fibrillin 2. In contrast, TCE had no effect on the expression of alpha-smooth muscle actin. These data suggest that TCE may cause cardiac valvular and septal malformations by inhibiting endothelial separation and early events of mesenchymal cell formation in the heart.

Influence of the contralateral carotid artery on neurologic complications following carotid endarterectomy.

To examine the effect of contralateral carotid artery stenosis on postoperative events, a retrospective review was made of 451 patients undergoing 510 carotid endarterectomies during a 6-year period. Three degrees of contralateral carotid stenosis were identified radiologically: 0% to 49%, 50% to 99%, and totally occluded. Each group was further separated into two categories according to preoperative symptoms. "Low risk" included asymptomatic lesions, transient ischemic attacks, and nonhemispheric symptoms; "high risk" described poststroke patients and urgent operations. The results show the incidence of stroke or death was not increased in patients with severely stenosed or occluded contralateral vessels in either low- or high-risk patients (p = 0.741 and p = 0.561, respectively). Patients in the high-risk category, however, had a significantly higher risk of postoperative complications than patients in the low-risk category (p less than 0.001). The study reaffirms that preoperative indications have a major influence on surgical outcome and suggests that the status of the contralateral artery has little bearing on postoperative events.

Content knowledge and problem-solving skill in reviewing medical charts.

Skills in reviewing medical charts have been demonstrated components of clinical competence related to knowledge base, level of clinical experience, and basic observational skills. A study of the generalizability of performance on chart review exercises, which controlled for knowledge in the content area, was undertaken to determine their potential in evaluating students' problem-solving ability. Results of the study indicate that the case specificity which has characterized simulated problem-solving tasks is largely case, rather than content, specificity: correlations between scores on single charts demonstrated no consistent relationships for measures of proficiency, efficiency, and diagnostic accuracy. However, averaging the scores on two charts and then computing correlations resulted in significant positive measures for both proficiency and efficiency. The effects of length and difficulty level on the generalizability of tests of problem-solving ability are areas suggested for future research.

Chart review skills: a dimension of clinical competence.

A study of undergraduate medical students' abilities to identify salient information in reviewing patient charts was conducted by members of the Department of Surgery at Southern Illinois University School of Medicine. Specific goals of the two-year study were to develop and test a method for assessing chart skills and to test the following hypotheses: (a) knowledge base is a component of chart review skill; (b) chart skills are related to basic observational skills; (c) performance on one chart is positively correlated with performance on other charts; (d) chart performance is affected by distraction and time pressure; and (e) chart performance improves with clinical experience. Evaluation instruments and methodology are described. Hypotheses a, b, and e and the time effect hypothesized in d were supported; hypothesis c was not supported. Results of the study provide a foundation for further research exploring the effect of instruction on chart performance and investigating the relationships between chart performance and other measures of clinical competence.

Urinary tract infections in kidney transplant recipients.

In 65 kidney transplant recipients who were followed up for a mean period of 14.7 months, the incidence of urinary tract infection (UTI), and how the incidence was affected by length of graft survival, age, HLA-A and HLA-B matches, complications, duration of Foley catheter use, and other aspects, were examined. The total incidence of infection included an unexpectedly high rate of late infections. The incidence was found to be statistically increased with nephrectomy, splenectomy, recatheterization, and age older than 40 years. There was no correlation noted with graft source, antigen match, graft loss, or previous history of UTI. A group of patients with persistent UTI was noted and an inability to suppress UTI with long-term therapy with antibiotics was found. The asymptomatic nature of most of the UTIs confirmed the need for frequent periodic cultures of urine in the immunosuppressed patient.

False positive 51Cr release tests during post-transplant immunological monitoring due to recipient serum radioactive contamination.

The occurrence of false positive 51Cr release test results in post-transplant immunological monitoring of human kidney graft recipients due to 131I carryover from renograms is described. False positivity was detected in 7 instances in 4 recipients, and suspected in 12 instances in 7 recipients, in a series of 46 consecutive transplant recipients. Technical methods and controls to detect and prevent such false positivity are described.

A prospective study to determine the efficacy of antibiotics in acute pancreatitis.

This study is a double "blind" prospective evaluation of the efficacy of antibiotics (Ampicillin) in the treatment of acute alcohol-induced and idiopathic pancreatitis. Fifty-eight patients with acute pancreatitis were randomly divided into antibiotic and non-antibiotic treatment groups. The two groups were comparable clinically at the onset of the study and other than for antibiotics received identical therapy. The patients without antibiotics had a clinical course equal or slightly more favorable than the antibiotic treatment group in all parameters examined. These data indicate that prophylactic use of Ampicillin is not indicated in patients with routine acute alcohol-induced or idiopathic pancreatitis. The role of prophylactic antibiotics in patients with pancreatitis related to biliary calculi and those with more severe varieties of acute hemorrhagic or necrotizing pancreatitis remains to be more clearly defined.