Selenium modulates β‐cyfluthrin‐induced liver oxidative toxicity in rats

This study was designed to investigate the possibility of β‐cyfluthrin to induce oxidative stress and biochemical perturbations in rat liver and the role of selenium in alleviating its toxic effects. Male Wister rats were randomly divided into four groups of seven each, group I served as control, group II treated with selenium (200 µg/kg BW), group III received β‐cyfluthrin (15 mg/kg BW, 1/25 LD₅₀), and group IV treated with β‐cyfluthrin plus selenium. Rats were orally administered their respective doses daily for 30 days. The administration of β‐cyfluthrin caused elevation in lipid peroxidation (LPO) and reduction in the activities of antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), glutathione S‐transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR). A decrease in reduced glutathione (GSH) content was also observed. Liver aminotransferases (AST and ALT) and alkaline phosphatase (ALP) were decreased, whereas lactate dehydrogenase (LDH) was increased. Selenium in β‐cyfluthrin‐induced liver oxidative injury of the rats modulated LPO, CAT, SOD, GSH, GST, GPx, and GR. Also, liver AST, ALT, ALP, and LDH were maintained near normal level due to selenium treatment. It is concluded that selenium scavenges reactive oxygen species and render a protective effect against β‐cyfluthrin toxicity. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1323–1329, 2014.     

Pathological Evaluation of Nipple‐Sparing Mastectomies with Emphasis on Occult Nipple Involvement: The Weill‐Cornell Experience with 325 Cases

Nipple‐sparing mastectomy (NSM) is an increasingly utilized surgical option in managing breast carcinoma; however, data on malignant involvement of a separately submitted nipple margin are scant. Consecutive NSM, including those performed for therapeutic and prophylactic purposes, over a 4‐year period (2007–2011), were studied. A separately submitted nipple margin was evaluated by permanent H&E preparations and via frozen section evaluation whenever requested. 325 consecutive NSM specimens, 208 (64%) therapeutic‐NSM, and 117 (36%) prophylactic‐NSM were studied. All nipples were clinically unremarkable. 86% (179/208) of nipple margins from therapeutic‐NSM and 100% (117/117) from prophylactic‐NSM showed no histopathologic abnormality. 14% (29/208) of nipple margins from therapeutic‐NSM and no nipple margin from prophylactic‐NSM showed malignancy. Frozen section evaluation was performed in 188/325 NSM (58%) with a sensitivity of 64% and specificity of 99%. Central tumor location and stage N2/N3 lymph node status were significantly associated with nipple margin positivity (χ² ≤ 0.05). Subsequent nipple resection was performed in 69% (20/29) of nipple margin‐positive cases with residual malignancy found in 40% (8/20, including three cases of invasive carcinoma). In a mean follow‐up of 33 months, one invasive carcinoma recurred in the “saved” nipple, 36 months after therapeutic‐NSM. 14% (29/208) of nipple margins in therapeutic‐NSM and no nipple margin (0/117) in prophylactic‐NSM showed malignancy. Central tumor location and N2/N3 stage were significantly associated with nipple margin positivity (χ² ≤ 0.05).     

The Effect of Polymerization Method in Stereo-active Block Copolymers on the Stability of Polymeric Micelles and their Drug Release Profile

Purpose

To investigate the effect of polymerization method on the stability and drug release properties of polymeric micelles formed using stereo-active block copolymers.

Methods

Diblock copolymers consisting of methoxy poly ethylene oxide (MePEO) and poly(lactide)s (PLA)s of different stereochemistry were synthesized by bulk or solution polymerization. Polymers and micelles were characterized for their chemical structure by ¹H NMR, optical rotation by polarimetry, critical micellar concentration by fluorescence spectroscopy, thermal properties by differential scanning calorimetry, morphology by transmission electron microscopy and size as well as kinetic stability by dynamic light scattering. Release of encapsulated nimodipine from polymeric micelles at different levels of loading was also investigated.

Results

Solution polymerization yielded a higher degree of crystallinity for stereo-regular PLA blocks. Consequently, the related polymeric micelles were kinetically more stable than those prepared by bulk polymerization. At high drug loading levels, the release of nimodipine was more rapid from polymeric micelles with crystalline cores. At lower levels of drug loading, drug release was slower and independent of the stereochemistry of the core.

Conclusions

The results underline the effect of polymerization method in defining core crystallinity in stereoregular block copolymer micelles. It also shows the impact of core crystallinity on enhancing micellar stability and drug release.     

Pleuraerkrankungen

Zeitschrift für Pneumologie - Pleuraerkrankungen bieten ein weites Spektrum an Differenzialdiagnosen. Häufigstes Symptom ist der Pleuraerguss, der zur Luftnot führen kann. Neben der...     

Helicobacter pylori infection in Kazakhstan: effect of water source and household hygiene

The epidemiology of Helicobacter pylori infection and risk factors associated with its transmission are not well understood. Kazakhstan is country with two ethnic groups, Asian (Kazakhs) and Western (Russians), living under similar socioeconomic conditions. The aim of this study was to examine the seroepidemiologic pattern of H. pylori and hepatitis A among the same individuals from both ethnic groups, with emphasis on water source and household sanitation practices. This was a cross-sectional seroepidemiologic study conducted among unrelated healthy individuals in Kazakhstan. From May through August 1999, individuals between the ages of 10 and 60 years from Almaty, Kazakhstan, were invited to participate. Demographic information, socioeconomic factors, living conditions, and various aspects of the local household environment including access to water were collected. A clean water index (CWI) was created based on combined factors, consistency of boiling water before drinking, frequency of storing and reusing water, and frequency of bathing and showering. H. pylori and hepatitis A antibodies were assessed by enzyme-linked immunosorbent assay. Two hundred eighty-eight individuals between the ages of 10 and 60 years participated. The prevalence of H. pylori infection was almost identical among the two ethnic groups (Russians 79% and Kazakhs 80%). H. pylori infection was inversely correlated with the CWI (i.e., 56%, 79%, and 95% for high, middle, and low, respectively (P < .05). Drinking river water had highest risk of H. pylori infection (OR = 13.6, 95% CI = 1.8-102.4; P < .01, compared with tap water). Crowding showed no significant effect on H. pylori prevalence. Anti-HAV antibodies were found in 86% of the population, 90% among the Russians versus 82% among the Kazakhs (OR = 1.8, 95% CI = 1.1-3.8, P = .05). Although the two infections were highly correlated (P < .001), antibody to both infections were present simultaneously in only 74%. The prevalence of H. pylori infection in Kazakhstan is very high. The data suggest that transmission of H. pylori can be water borne, related to poor sanitary practices, or both. The high prevalence of antibodies to H. pylori and HAV among this population is a marker for poor sanitation and hygienic practices. Reducing the rate of H. pylori transmission will require improvements in overall sanitation including clean water, waste disposal, as well as in household hygienic practices.     

Circulating anti-HLA antibodies in patients with chronic hepatitis C: relation to disease activity

The human leukocyte antigens (HLA) may influence host immune to infection. In the mean time chronic hepatitis C (CHC) results in the appearance of a variety of autoantibodies. We investigated the frequency of circulating anti-HLA antibodies and none organ specific autoantibodies in patients with chronic hepatitis C at different stages of disease activity. Sixty-seven untreated male patients with CHC (anti-HCV antibody and HCV RNA positive), in whom 38 had elevated serum alanine aminotransferase (ALT) levels and 29 persistently normal serum ALT values, and 23 age-matched normal male subjects were studied. None of them had a history of blood transfusion. Sera were analyzed for immunoglobulin G-anti-HLA class I and class II antibodies by enzyme-linked immunosorbant assay, and for non-organ-specific autoantibodies (antinuclear, anti-smooth muscle, anti-mitochondrial and anti-liver/kidney microsomes type 1 antibodies) using indirect immunofluorescence technique. Circulating anti-HLA class I and class II antibodies were detected in 15/67 (22.4 %) and 11/67 (16.4 %) respectively, while none of normal controls had detectable anti-HLA antibodies in the serum. The frequency of detecting anti-HLA antibodies was significantly higher in patients with elevated serum ALT than persistently normal serum ALT values (31.6 % vs 10.3 %; P = 0.039) and was associated with non-organ-specific serum autoantibodies in 11/15 (73.3 %) patients. Those with circulating anti-HLA antibodies had significantly higher levels of serum aminotransferases, gamma-glutamyl transpeptidase, viral load and necroinflammatory and fibrosis scores in liver biopsies than patients with negative anti-HLA antibody (P < 0.001). In conclusions, the presence of circulating antibodies against HLA class I and class II molecules in HCV antibodies may represent an autoimmune response to HLA antigens and may play a pathogenetic role in the induction of the HCV-related chronic liver disease.     

Radiation Exposure from Diagnostic Imaging Studies Among Patients with Inflammatory Bowel Disease in a Safety-Net Health-Care System

Background/Aims

Radiographic imaging studies are important in the management of patients with inflammatory bowel disease (IBD), but are associated with radiation exposure. IBD patients in a safety-net health-care system may be at risk of high exposure to radiation. Our purpose was to identify associations of high-dose radiation exposure among an ethnically diverse cohort of IBD patients in a safety-net health-care system.

Methods

A study was performed on patients with IBD receiving care from the Harris County Hospital District. Radiation exposure was calculated using total number of imaging studies performed between from 2000 and 2010 and estimates of radiation dose per study. Associations of high-dose radiation exposure, defined as a cumulative effective dose (CED) >50 mSv, were identified by using univariate and multivariate logistic regression.

Results

The study cohort of 278 patients with IBD was ethnically diverse, with 30 % Caucasian, 44 % African–American, and 26 % Hispanic. The median CED was 10.40 mSv (SD 20.02). Annualized radiation doses were 3.45 mSv/year among patients with Crohn’s disease (CD) and 1.27 mSv/year among patients with ulcerative colitis, p < 0.02. Approximately 13 % of IBD patients received a CED >50 mSv. There were no differences in radiation exposure based on age, gender, or race/ethnicity.

Conclusions

A small proportion of IBD patients in a safety-net health-care system received high doses of diagnostic radiation exposure. Use of diagnostic imaging studies that limit radiation exposure should be encouraged.