Structural and functional impairment of the hypothalamo- pituitary-interrenal axis in fish exposed to bleached kraft mill effluent in the St Maurice River,Quebec

The effects of bleached kraft mill effluent (BKME) on blood cortisol levels and the morphology of the pituitary-interrenal axis were investigated in two species of teleost fish, the northern pike, Esox lucius, and the yellow perch, Perca flavescens, sampled upstream and downstream from a pulp and paper mill on the St Maurice River, Quebec. Fish were acutely stressed by a standardized capture and sampling protocol at both sites, and their ability to elevate blood cortisol levels in response to the capture stress was compared. Blood cortisol levels in fish from the upstream site (>100 ng/ml plasma) were higher than the levels in fish from the BKME site, and the pituitary corticotropes and the interrenal steroidogenic cells of the upstream fish were larger and had larger nuclei compared with cells from the downstream fish. The low blood cortisol levels in fish exposed to BKME were correlated to cellular atrophy within the hypothalamo-pituitary-interrenal (HPI) axis. The reduced ability to elevate blood cortisol in response to an acute stress may be an endocrine dysfunction occuring in fish chronically exposed to chemical stressors in their environment     

Bile Acid Metabolism in Children with Cystic Fibrosis

ABSTRACT. Recycling of bile acids through the enterohepatic cycle is very efficacious. Bile acids contribute to bile formation and, by forming micelles, participate in lipid solubilization and absorption. The small fraction which escapes in the feces, is synthesized daily by the liver to compensate for losses. In CF, bile acid malabsorption has been documented; these large losses are accompanied by an interruption in the enterohepatic circulation with concomitant reduction in bile acid pool and disturbances in biliary composition. The various intraluminal factors implicated in bile acid malabsorption include: unhydrolysed triglycerides and phospholipids, precipitation of bile acids in acidic duodenal content, adsorption to residues and modification of colonic microflora. A defect in bile acid ileal uptake has also been advocated. These disturbances in bile acid metabolism associated with CF might lead to aggravation of diarrhea and steatorrhea, cholelithiasis and perhaps liver disease.     

Evidence for 25-hydroxyvitamin D deficiency as a factor contributing to osteopenia in diabetic patients with idiopathic haemochromatosis

Abstract. Osteopenia is frequently encountered in the course of idiopathic haemochromatosis. In order to establish the mechanism of this bone disorder, the following parameters were studied in nine diabetic patients with idiopathic haemochromatosis: (i) the intestinal calcium absorption measured by using a double radiotracer technique; (ii) the bone mineral content (BMC, mg/cm²) determined on the forearm by the Cameron's absorptiometry technique, (iii) the plasma 25 hydroxyvitamin D (25-OH-D ng/ml) by a competitive protein-binding radioassay. The results were compared to those obtained in ten controls and in eight diabetics without haemochromatosis. The patients suffering from haemochromatosis had a significant fall in total fractional absorption of calcium and BMC as compared with controls and diabetics without haemochromatosis. Furthermore plasma 25-OH-D was significantly lower in haemochromatosis patients (51±0–6 ng/ml) than in controls (16-4±1–3 ng/ml, P < 001) and in diabetics without haemochromatosis (14-2±1–4 ng/ml, P < 0–02). These results indicate that haemochromatosis patients exhibit important disturbances in calcium homeostasis, i.e. low concentration of plasma 25-OH-D and reduced intestinal absorption of calcium. The latter abnormalities may well be related to the bone rarefaction observed in these patients.     

Persistent Functional Atrioventricular Block in Two Patients with Prolonged QT Intervals; Elucidation of the Mechanism of Block

This article describes two infants with prolonged QT interval and intermittent second-degree atrioventricular block. An asymptomatic 14-month-old child with persistent 2:1 atrioventricular conduction since birth underwent electrophysiology study including measurements with a contact monophasic action potential catheter. During 2:1 conduction, atrioventricular block occurred distal to the site of the His-bundle recording. Monophasic action potential duration was closely related to prior RR intervals. Single premature atrial or ventricular depolarizations during 1:1 conduction followed by a pause, lead to monophasic action potential prolongation and subsequent 2:1 atrioventricular conduction, which was perpetuated by the resulting long RR intervals. Paired premature ventricular contractions or short bursts of ventricular pacing elicited monophasic action potential shortening and subsequent 1:1 atrioventricular conduction that was perpetuated by the resulting short RR intervals. A second infant presented at birth with a prolonged QT interval, ventricular tachycardia, and episodes of second-degree atrioventricular block with persistent 2:1 atrioventricular conduction. The atrioventricular block was repeatedly elicited by single premature ventricular contractions and terminated by ventricular couplets. We conclude that the atrioventricular block in both patients is functional in nature and results from the interrelationships between ventricular rate, action potential duration, and His-Purkinje system refractoriness.     

No Detection of Interferon-γ Activity During Early Pregnancy in the Mouse

PROBLEM: Interferons (IFN) have been shown to be secreted by the trophectoderm of implanting embryos in different species, in particular ungulates. In the pig, a clear-cut IFN-γ production, the role of which is unknown, was found in the trophoblast at implantation. A murine counterpart to these IFNs has not yet been identified. METHOD: Two sets of experiments were conducted to test the presence of IFN-γ in the mouse conceptus. First, day 4 blastocysts were collected from Swiss mice and their antiviral activity measured in a microassay using mouse L 929 cells and vesicular stomatitis virus (VSV) in the presence or absence of anti-IFN-γ antibodies. In a second set of experiments, uteri from Swiss mice on days 5.5 and 6.5 of pregnancy were flushed and the resulting fluids assayed in a specific and sensitive ELISA test. RESULTS: In the antiviral assay, no consistent IFN-like activity was found. The viral challenge also revealed a high susceptibility of mouse blastocysts to VSV infection. By ELISA, all but two samples (N = 75), whether on 5.5 or 6.5, were found negative. CONCLUSION: We conclude that in this rodent species IFN-γ is most probably not involved in early maternal-fetal interactions.     

T HELPER 1/2 LYMPHOCYTE URINARY CYTOKINE PROFILES IN RESPONDING AND NONRESPONDING PATIENTS AFTER 1 AND 2 COURSES OF BACILLUS CALMETTE-GUERIN FOR SUPERFICIAL BLADDER CANCER

PURPOSE: Interleukin (IL)-2 and interferon-gamma are released during T helper 1 lymphocyte responses and IL-10 is released during T helper 2 lymphocyte responses. We have previously reported that a T helper 1 lymphocyte urinary cytokine profile is associated with a favorable prognosis after bacillus Calmette-Guerin (BCG) treatment. We evaluated the T helper 1/2 lymphocyte cytokine profiles during courses 1 and 2 of 6 weekly BCG instillations. MATERIALS AND METHODS: Urinary interferon-gamma, IL-2 and IL-10 were measured by enzyme-linked immunosorbent assay after each of 6 weekly instillations of 150 mg. BCG, Pasteur strain, in 19 patients with superficial stages Ta and T1 bladder cancer, and carcinoma in situ. The 11 patients who did not respond to course 1 were re-treated according to the same schedule and reevaluated. RESULTS: During course 1 interferon-gamma was higher than during course 2 (p <0.001), which was associated with nonrecurrence (p <0.001). In contrast, IL-2 cytokine was higher after course 2 (p <0.01), which was associated with a BCG response (p = 0.01). Interferon-gamma and IL-10 correlated during courses 1 and 2 (p = 0.04 and 0.0004, respectively). We distinguished groups 1-immediate T helper 1 lymphocyte profile consisting of responders to course 1 with high interferon-gamma, IL-2 and IL-10, 2-delayed T helper 1 lymphocyte profile consisting of responders to course 2 with early high IL-2 and 3-consisting of nonresponders to the 2 courses with low interferon-gamma, IL-2 and IL-10. CONCLUSIONS: A T helper 1 lymphocyte urinary cytokine profile was associated with a clinical response to BCG. A repeat BCG course induces a favorable immune response in a subset of patients, suggesting that maintenance therapy may be beneficial.     

Hyaluronectin in normal human skin and in basal cell carcinoma

The localization of hyaluronectin has been studied in normal skin and in basal cell carcinoma. In fetal skin it is abundant in the dermis but absent from the epidermis, and in adult skin it is totally absent except in the hair sheaths and bulbs. In basal cell carcinoma it is abundant only in the stroma reaction. The presence of this protein in mesenchymatous tissues seems to be linked to zones of physiological or neoplastic proliferation.     

Epidemiology and morbidity of regional anesthesia in children: a follow-up one-year prospective survey of the French-Language Society of Paediatric Anaesthesiologists (ADARPEF)

Background: The French‐Language Society of Paediatric Anaesthesiologists (ADARPEF) designed a 1‐year prospective, multicenter and anonymous study to update both epidemiology and morbidity of regional anesthesia in children. Methods: From November 2005 to October 2006, data from participating hospitals were recorded using an identification form, a data recording form, and a complication form. Information collected included the characteristics of the hospitals, the number and type of regional anesthetics (RA), the age of the involved children as well as the incidence, and type of complications. Results: Data collected in 47 institutions included 104 612 pure general anesthesias (GAs), 29 870 GAs associated with regional blocks, and 1262 pure regional blocks. Central blocks accounted for 34% of all RA. Peripheral blocks (66%) were upper or lower limb blocks (29% of peripheral blocks), trunk blocks, and face blocks (71%). In children aged ≤3 years, the percentage of central blocks was similar to the peripheral ones (45% vs 55), while in older children, peripheral blocks were more than four times used than central ones. Complications (41 involving 40 patients) were rare and usually minor. They did not result in any sequelae. The study revealed an overall rate of complication of 0.12%; CI 95% [0.09–0.17], significantly six times higher for central than for peripheral blocks. Conclusions: As a result of the low rate of complications, RA techniques have a good safety profile and can be used to provide postoperative analgesia. In addition, the results should encourage anesthesiologists to continue to use peripheral instead of central (including caudal) blocks as often as possible when appropriate.