Characterization of Leishmania colombiensis sp. n (Kinetoplastida: Trypanosomatidae), a new parasite infecting humans, animals, and phlebotomine sand flies in Colombia and Panama.

Characterization of Leishmania colombiensis sp.n. is presented, which on the basis of biological and molecular criteria, appears to be a new member of the L. braziliensis complex. A total of nine isolates of the new parasite were made in Colombia and Panama between 1980 and 1986: two from human cases of cutaneous leishmaniasis, six from phlebotomine sand flies, and one from a sloth. Although most closely related to L. lainsoni, L. colombiensis sp.n. is clearly distinguishable from other members of the genus by its reactivity with monoclonal antibodies, isoenzyme electrophoresis, and restriction endonuclease fragment patterns of kinetoplast DNA (k-DNA).     

Perimount® Bovine Pericardial Valve to Restore Pulmonary Valve Competence Late after Right Ventricular Outflow Tract Repair

Objective. No ideal option exists for restoring pulmonary valve competence late after repair of the congenitally abnormal right ventricular outflow tract (RVOT). This has driven a continued search for new alternatives. Texas Children’s Hospital has recently used the Carpentier‐Edwards Perimount RSR Pericardial Aortic Prosthesis (Edwards Lifesciences, Irvine, Calif, USA) for this indication and reports the initial experience. Design. Retrospective chart review. Setting. Academically affiliated tertiary‐care pediatric hospital. Patients. Twenty‐six patients who underwent pulmonary valve replacement with the Perimount^® valve late after RVOT reconstruction between June 2002 and November 2005. Interventions. No prospective interventions. Outcomes Measures. Hospital morbidity and mortality. Valve function assessed by follow‐up visits and echocardiograms. Results. Mean age and weight of the patients were 20.3 ± 9.8 years (range 7.0–45.1 years) and 56.2 ± 18.1 kg (range 35.8–109 kg). Twenty‐two patients (85%) had severe pulmonary insufficiency (PI), 23 (89%) had symptomatic right heart failure, and 14 (54%) had moderate to severe right ventricular dysfunction. Average prosthetic valve size was 23 mm (range 19–27 mm). Twenty‐one (88%) patients were extubated within 24 hours. There was no hospital mortality. Median length of stay for all patients from day of surgery was 6 days (range 3–56 days). Median length of last echocardiography follow‐up was 12.4 months (range 0.1–37.6 months). At that time, 16 of the 26 (62%) patients had improved right ventricular function, no patient demonstrated significant RVOT obstruction, and 24 patients (92%) have no PI or mild PI. Freedom from death, reintervention, or reoperation on the pulmonary valve is 100% at 2.5 years. Conclusion. Initial results with the Perimount^® bovine pericardial tissue prosthesis for pulmonary valve replacement are encouraging. Further follow‐up is required to define long‐term function and durability.     

Mammary gland sympathetic innervation is a major component in type 1 deiodinase regulation

Recent observations have shown that in lactating rats previously deprived of suckling, either suckling stimulus or ip injection of norepinephrine was capable of increasing mammary deiodinase type 1 (M-D1) mRNA content and enzyme activity. In the present work, we show that intact efferent sympathetic mammary innervation is required to restore both mammary D1 mRNA content and enzyme activity, whereas suckling-induced secretion of catecholamines from the adrenal glands does not seem to participate in M-D1 enzyme regulation. The data also indicate that the sympathetic reflex activation in response to suckling involves two complementary autonomic components: (1) activation, presumably through mammary segmental arrangement affecting neighboring mammary glands; and (2) an individual reflex regulatory mechanism capable of maintaining M-D1 activity within each mammary gland. In addition to these findings, we show that the suckling-induced sympathetic activation of M-D1 activity could be blocked by prior activation of ductal mechanoreceptors. This set of regulatory and counterregulatory mechanisms seems to ensure the optimal control of mammary energetic expenditure according to litter size.     

Eight-year incidence of hypertension in Mexican-Americans and non-Hispanic whites. The San Antonio Heart Study.

The prevalence of hypertension has been reported to be lower in Mexican-Americans (MAs) than in non-Hispanic whites (NHWs). This finding is paradoxical since, compared to NHWs, MAs are generally more obese, and generally have a higher prevalence of non-insulin-dependent diabetes mellitus (NIDDM), both of which are risk factors for hypertension. Thus far, no data exist on the incidence of hypertension in MAs. We therefore determined the 8-year incidence of hypertension (defined as a diastolic blood pressure greater than or equal to 95 mm Hg or current treatment with antihypertensive medications) in 1462 subjects (867 MAs and 595 NHWs) who were normotensive at baseline and who subsequently participated in the 8-year follow-up of the San Antonio Heart Study, a population-based study of diabetes and cardiovascular risk factors. Hypertension developed in 79 MAs (9.1%) and 55 NHWs (9.2%). The age-adjusted odds ratio (OR) for ethnicity (MA/NHW) was 0.83 (95% CI = 0.48, 1.44) in men and 1.25 (95% CI = 0.76, 2.04) in women. After adjusting for age, gender, body mass index, NIDDM, and level of educational attainment using multiple logistic regression, Mexican-Americans had an incidence of hypertension similar to non-Hispanic white (OR = 0.80, 95% CI = 0.52, 1.22). The similar incidence of hypertension in MAs is in striking contrast to the markedly increased incidence of NIDDM in this ethnic group relative to non-Hispanic whites. The cause of the relative protection from hypertension in MAs is unknown.     

An improved method of 90% pancreatectomy using a low dose of streptozotocin at the pancreaticoduodenal artery results in a rapid diabetic stage in dogs

Abstract An improved method of inducing diabetes in dogs was developed. This method included 90% pancreatectomy, 2 mg/kg streptozotocin (STZ) perfused into pancreaticoduodenal artery, and the fixation suture of the duodenum to the costo-abdominal wall. Vasopressin injection administered to the animals before surgery reduced bleeding. All dogs used in this procedure survived and became diabetic. One month after the procedure the pancreatic islets were reduced in volume and the number compared with pancreas tissue obtained during the surgery. Acinar tissue remained with a normal histology, and exocrine function maintained the physiological parameters, except for a soft faecal consistency. We conclude that this procedure is effective in inducing experimental diabetes in dogs.