Effects of bile acids on ventricular muscle contraction and electrophysiological properties: studies in rat papillary muscle and isolated ventricular myocytes

Summary The effects of sodium salts of various bile acids on the contractile force and the electrophysiological properties of rat ventricular muscle were studied in vitro. Primary, conjugated, and secondary bile acids were studied in a concentration range of 10^–9–10^–6 mol/l, which corresponds to concentrations found in the plasm of patients with cholestatic jaundice. In general, the bile acid induced a negative inotropic effect which was manifested as a reduction in active tension, maximum rate of tension activation, and maximum rate of tension relaxation. Twitch duration and time to peak tension were unaffected by the bile acids. The negative inotropism was associated with a reduction in ventricular action potential duration. Resting potential, action potential amplitude, and maximum upstroke velocity of phase 0 depolarization were unaffected. Voltage clamp experiments in rat ventricular myocytes demonstrated that sodium taurocholate decreased the slow inward current and slightly increased the outward potassium current. Hence, these effects on the membrane currents are probably responsible for the negative inotropic effect. Send offprint requests to O. Binah at the above address     

Epilation of hair-bearing urethral grafts using the neodymium:YAG surgical laser

Nonhair-bearing skin should be used when grafting is necessary during urethroplasty for stricture or hypospadias repair. Occasionally, this is not possible or hair-bearing skin is used inadvertently. Traditionally, electrocoagulation has been the method used for epilation when intraluminal hair has become a problem, such as interfering with flow, as a focus for recurrent urinary tract infection or acting as a nidus for calculus formation. Electrocautery also is performed during grafting in an attempt to prevent the growth of hair when hair-bearing skin is used. Unfortunately, due to lack of penetration the hair follicles are not destroyed and the epilating procedure fails or is only partially successful. The neodymium:YAG surgical laser can photocoagulate tissue to a depth up to 5.0 mm, and thus, has the ability to destroy hair follicles. We report 4 cases presenting with clinical problems directly related to hair-bearing urethral grafts successfully treated by neodymium:YAG laser epilation.     

Bactericidal/permeability-increasing protein in host defense and its efficacy in the treatment of bacterial sepsis

The 55-kD bactericidal/permeability-increasing protein (BPI) is a neutrophil-derived polypeptide belonging to a family of lipid and endotoxin binding proteins. BPI is composed of two functionally distinct structural domains: a potently antibacterial and antiendotoxin ∼ 20-kD aminoterminal half, and an opsonic carboxy-terminal portion. In multiple animal models, a recombinant amino-terminal fragment of BPI (rBPI₂₁) is nontoxic and protects against gram-negative bacteria and endotoxin. In humans, rBPI₂₁ is also nontoxic and nonimmunogenic and has undergone phase II/III clinical trials with apparent therapeutic benefit.     

Adenocarcinoma arising in a chondroid syringoma of vulva.

Chondroid syringoma of the vulva is an extremely rare tumor. Of the previously reported cases, only one was clinically malignant. The authors describe a case of chondroid syringoma of the right labium majus from which arose a papillary adenocarcinoma. A right inguinal lymph node was replaced with metastatic adenocarcinoma.     

Screening for type 2 diabetes mellitus in children and adolescents: attitudes, barriers, and practices among pediatric clinicians.

OBJECTIVE: The American Diabetes Association (ADA) recommends screening children at risk for type 2 diabetes with a fasting plasma glucose test or an oral glucose tolerance test. The purpose of this study was to describe attitudes, barriers, and practices related to type 2 diabetes screening in children among pediatric clinicians. METHODS: Pediatricians, nurse practitioners and physician assistants from a multispecialty, group practice in Eastern Massachusetts completed a mailed survey. To assess screening practice, three vignettes were presented representing pediatric patients with low, moderately high, and high risk for type 2 diabetes. The moderately high-risk and high-risk patients met ADA criteria for screening. ADA-consistent practice was defined as only screening the moderately high-risk and high-risk patients; lower-threshold practice was defined as also screening the low-risk patient; and higher threshold practice was screening only the high-risk patient. RESULTS: Sixty-two of 90 clinicians responded (69%). Based on intent to screen in the 3 vignettes, 21% of respondents reported ADA-consistent screening practice, 39% lower-threshold, and 35% higher-threshold screening practice. Five percent had incomplete or nonclassifiable responses. Many clinicians ordered screening tests other than those recommended by the ADA; few (< or =8% in any vignette) ordered only an ADA-recommended test. Preferences for nonfasting tests were influenced by nonmedical factors such as access to or cost of transportation. Inadequate patient education materials and unclear recommendations for appropriate screening methods were the most frequently reported moderate/strong barriers to screening. CONCLUSIONS: Most respondents reported type 2 diabetes screening practices that differed from current ADA recommendations. Our findings suggest that type 2 diabetes screening tests must be practical for clinicians and patients if they are to be used in pediatric practice. Further study of the benefits and cost-effectiveness of type 2 diabetes screening in children is warranted to clarify the role and optimal methods for screening in pediatric primary care.     

Clinical measures, smoking, radon exposure, and risk of lung cancer in uranium miners.

OBJECTIVES: Exposure to the radioactive daughters of radon is associated with increased risk of lung cancer in mining populations. An investigation of incidence of lung cancer following a clinical survey of Ontario uranium miners was undertaken to explore whether risk associated with radon is modified by factors including smoking, radiographic silicosis, clinical symptoms, the results of lung function testing, and the temporal pattern of radon exposure. METHODS: Miners were examined in 1974 by a respiratory questionnaire, tests of lung function, and chest radiography. A random selection of 733 (75%) of the original 973 participants was followed up by linkage to the Ontario Mortality and Cancer Registries. RESULTS: Incidence of lung cancer was increased threefold. Risk of lung cancer among miners who had stopped smoking was half that of men who continued to smoke. There was no interaction between smoking and radon exposure. Men with lung function test results consistent with airways obstruction had an increased risk of lung cancer, even after adjustment for cigarette smoking. There was no association between radiographic silicosis and risk of lung cancer. Lung cancer was associated with exposures to radon daughters accumulated in a time window four to 14 years before diagnosis, but there was little association with exposures incurred earlier than 14 years before diagnosis. Among the men diagnosed with lung cancer, the mean and median dose rates were 2.6 working level months (WLM) a year and 1.8 WLM/year in the four to 14 year exposure window. CONCLUSIONS: Risk of lung cancer associated with radon is modified by dose and time from exposure. Risk can be substantially decreased by stopping smoking.     

Autoamputation of the foot caused by untreated gas gangrene: a case report

Gas-producing diabetic foot infections are limb-threatening emergencies commonly encountered by foot and ankle surgeons. Appropriate treatment includes aggressive surgical debridement, parenteral antibiotics, and postoperative wound care. The authors present a unique case of a patient who refused treatment for a deep-space gas-producing infection, resulting in autoamputation of the foot. The authors also discuss the confusion surrounding the definition of gas gangrene.