T2182C mutation in 23S rRNA is associated with clarithromycin resistance in Helicobacter pylori isolates obtained in Bangladesh

Twelve clarithromycin-resistant (MIC, > or = 1 microg/ml) Helicobacter pylori isolates were analyzed for point mutations in the 23S rRNA gene. Sequence analysis of all of the resistant isolates revealed a T-to-C transition mutation at position 2182. Transformation experiments confirmed that a single T-to-C transition mutation at position 2182 is associated with clarithromycin resistance.     

Evaluation of Biocompatibility and Osteogenic Potential of Tricalcium Silicate–based Cements Using Human Bone Marrow–derived Mesenchymal Stem Cells

Introduction

The success of endodontic regeneration lies in the appropriate combination of stem cells and bioactive materials. Several novel dental materials are available on the market in this regard. Hence, the current study aimed to evaluate the proliferation, differentiation, and osteogenic potential of human bone marrow–derived mesenchymal stem cells (hBMSCs) onto biomaterials like ProRoot MTA (MTA; Dentsply Tulsa Dental, Tulsa, OK), Biodentine (BD; Septodont, Saint Maur de Fosses, France), and EndoSequence Root Repair Material (ERRM; Brasseler USA, Savannah, GA).

Ischemia-Mediated Dysfunction in Subpapillary Myocardium as a Marker of Functional Mitral Regurgitation

ObjectivesThe goal of this study was to test whether ischemia-mediated contractile dysfunction underlying the mitral valve affects functional mitral regurgitation (FMR) and the prognostic impact of FMR.BackgroundFMR results from left ventricular (LV) remodeling, which can stem from myocardial tissue alterations. Stress cardiac magnetic resonance can assess ischemia and infarction in the left ventricle and papillary muscles; relative impact on FMR is uncertain.MethodsVasodilator stress cardiac magnetic resonance was performed in patients with known or suspected coronary artery disease at 7 sites. Images were centrally analyzed for MR etiology/severity, mitral apparatus remodeling, and papillary ischemia.ResultsA total of 8,631 patients (mean age 60.0 ± 14.1 years; 55% male) were studied. FMR was present in 27%, among whom 16% (n = 372) had advanced (moderate or severe) FMR. Patients with ischemia localized to subpapillary regions were more likely to have advanced FMR (p = 0.003); those with ischemia localized to other areas were not (p = 0.17). Ischemic/dysfunctional subpapillary myocardium (odds ratio: 1.24/10% subpapillary myocardium; confidence interval: 1.17 to 1.31; p < 0.001) was associated with advanced FMR controlling for infarction. Among a subgroup with (n = 372) and without (n = 744) advanced FMR matched (1:2) on infarct size/distribution, patients with advanced FMR had increased adverse mitral apparatus remodeling, paralleled by greater ischemic/dysfunctional subpapillary myocardium (p < 0.001). Although posteromedial papillary ischemia was more common with advanced FMR (p = 0.006), subpapillary ischemia with dysfunction remained associated (p < 0.001), adjusting for posteromedial papillary ischemia (p = 0.074). During follow-up (median 5.1 years), 1,473 deaths occurred in the overall cohort; advanced FMR conferred increased mortality risk (hazard ratio: 1.52; 95% confidence interval: 1.25 to 1.86; p < 0.001) controlling for left ventricular ejection fraction, infarction, and ischemia.ConclusionsIschemic and dysfunctional subpapillary myocardium provides a substrate for FMR, which predicts mortality independent of key mechanistic substrates.     

Anti-Hyperglycemic,Anti-Hyperlipidemic and Antioxidant Potential of Alcoholic-Extract of Sida cordifolia (Areal Part) in Streptozotocin-Induced-Diabetes in Wistar-Rats

Sida cordifolia is a shrub found throughout the tropical and sub-tropical plains. All parts of the plant are used as anti-rheumatic, antipyretic, anti-asthmatic, laxative, diuretic, vasorelaxative, hypotensive, central nervous system depressant, antioxidant, analgesic and hypoglycemic. The present study was aimed to evaluate the hypoglycemic, anti-hyperlipidemic and antioxidant potential of alcoholic-extract obtained from areal part of S. cordifolia in streptozotocin-induced-diabetes in wistar-rats. Diabetes was induced with streptozotocin at the intra-peritoneal dose of 55 mg/kg. Diabetic rats were treated with alcoholic extract of S. cordifolia at dosage of 200, 400 mg/kg and glibenclamide (5 mg/kg) after sub-acute administration for 28 days. Alcoholic extract of S. cordifolia at 400 mg/kg significantly improved the body-weight whereas significantly decreased the blood glucose level in diabetic rats. However at 400 mg/kg, the alcoholic extract of S. cordifolia showed beneficial effect indicating significant decrease in total cholesterol, triglycerides, low density lipids, plasma-creatinine, plasma-urea nitrogen and lipid-peroxidation and a significant increase in high density lipid-level in diabetic rats. Interestingly at 400 mg/kg, a significant increase in antioxidant enzymes such as catalase and superoxide-dismutase-activity was seen in the diabetic rats. The dose 200 mg/kg of alcoholic extract of S. cordifolia showed non-significant change in diabetic rats. The above therapeutic-potential of alcoholic extract of areal parts of plant may be because of the presence of bioactive compounds such as glycosides, resins, alkaloids, sterols, saponins and flavonoids. Thus, the findings of the present study indicate that the alcoholic extract of S. cordifolia at dosage level of 400 mg/kg produces anti-diabetic effect in the streptozotocin-induced diabetes in wistar-rats.     

Label‐free mass spectrometry‐based quantification of hemagglutinin and neuraminidase in influenza virus preparations and vaccines

Please cite this paper as: Getie‐Kebtie et al. (2012) Label‐free mass spectrometry‐based quantification of hemagglutinin and neuraminidase in influenza virus preparations and vaccines. Influenza and Other Respiratory Viruses 7(4), 521–530. Background Influenza vaccination is the primary method for preventing influenza and its severe complications. An accurate rapid method to determine hemagglutinin (HA) concentration would facilitate reference antigen preparation and consequently expedite availability of seasonal as well as pandemic vaccines. Objective The goal of this study was to develop a label‐free mass spectrometry (MS) based method that enables simultaneous identification and quantification of HA, neuraminidase (NA), and other viral proteins and protein contaminations in influenza vaccine or virus preparations. Methods The method presented is based on LC/MSE analysis of vaccine or virus preparations tryptic digests spiked with a known amount of protein standard from which a universal response factor is generated and applied to calculate the concentration of proteins identified in the mixture. Results We show that, with the use of an appropriate internal standard, the label‐free MS‐based protein quantification method is applicable for simultaneous identification and absolute quantification of HA and identification and relative quantification of other influenza proteins as well as protein impurities in influenza vaccines and virus preparations. We show that different subtype recombinant HA is preferred internal standard that provides the most accurate results in absolute quantification of HAs and other influenza proteins. We applied this method to measure the absolute quantity of HA as well as relative quantities of other viral proteins and impurities in preparations of whole virus and monovalent vaccine, providing data to demonstrate strain‐dependent differences in the amount of NA. Conclusion The label‐free MS method presented here is ideally suited for timely preparation of reference material needed for potency testing of seasonal and pandemic vaccines.     

Potency under pressure: the impact of hydrostatic pressure on antigenic properties of influenza virus hemagglutinin

Background

Influenza vaccines are effective in protecting against illness and death caused by this seasonal pathogen. The potency of influenza vaccines is measured by single radial immunodiffusion (SRID) assay that quantifies antigenic forms of hemagglutinin (HA). Hydrostatic pressure results in loss of binding of influenza virus to red blood cells, but it is not known whether this infers loss of potency.

Objectives

Our goal was to determine the impact of pressure on HA antigenic structure.

Methods

Viruses included in the 2010–2011 trivalent influenza vaccine were subjected to increasing number of cycles at 35 000 psi in a barocycler, and the impact of this treatment measured by determining hemagglutination units (HAU) and potency. Potency was assessed by SRID and immunogenicity in mice.

Results

After 25 cycles of pressure, the potency measured by SRID assay was below the limit of quantification for the H1N1 and B viruses used in our study, while the H3N2 component retained some potency that was lost after 50 pressure cycles. Pressure treatment also resulted in loss of HAU, but this did not strictly correlate with the potency value. Curiously, loss of potency was abrogated when influenza A, but not B, antigens were exposed to pressure in chicken egg allantoic fluid. Protection against pressure appeared to be mediated by specific interactions because addition of bovine serum albumin did not have the same effect.

Conclusions

Our results show that pressure‐induced loss of potency is strain dependent and suggests that pressure treatment may be useful for identifying vaccine formulations that improve HA stability.     

Tephrosia purpurea Ameliorates N‐Diethylnitrosamine and Potassium Bromate‐Mediated Renal Oxidative Stress and Toxicity in Wistar Rats

Abstract: In an earlier communication, we have shown that Tephrosia purpurea ameliorates benzoyl peroxide‐induced oxidative stress in murine skin (Saleem et al. 1999). The present study was designed to investigate a chemopreventive efficacy of T. purpurea against N‐diethylnitrosamine‐initiated and potassium bromate‐mediated oxidative stress and toxicity in rat kidney. A single intraperitoneal dose of N‐diethylnitrosamine (200 mg/kg body weight) one hr prior to the dose of KBrO₃ (125 mg/kg body weight) increases microsomal lipid peroxidation and the activity of xanthine oxidase and decreases the activities of renal antioxidant enzymes viz., catalase, glutathione peroxidase, glutathione reductase and glucose‐6‐phosphate dehydrogenase, phase II metabolizing enzymes such as glutathione‐S‐transferase and quinone reductase and causes depletion in the level of renal glutathione content. A sharp increase in blood urea nitrogen and serum creatinine has also been observed. Prophylactic treatment of rats with T. purpurea at doses of 5 mg/kg body weight and 10 mg/kg body weight prevented N‐diethylnitrosamine‐initiated and KBrO₃ promoted renal oxidative stress and toxicity. The susceptibility of renal microsomal membrane for iron ascorbate‐induced lipid peroxidation and xanthine oxidase activities were significantly reduced (P<0.01). The depleted levels of glutathione, the inhibited activities of antioxidant enzymes, phase II metabolizing enzymes and the enhanced levels of serum creatinine and blood urea nitrogen were recovered to a significant level (P<0.01). All the antioxidant enzymes were recovered dose‐dependently. Our data indicate that T. purpurea besides a skin antioxidant can be a potent chemopreventive agent against renal oxidative stress and carcinogenesis induced by N‐diethylnitrosamine and KBrO₃.     

Protective effects of Picorrhiza kurroa extract against 2-acetylaminofluorene-induced hepatotoxicity in Wistar rats.

Picrorrhiza kurroa has been shown to impart significant hepatoprotective activities, partly by modulation of free radical--induced lipid peroxidation. Lipid peroxidation and reactive oxygen species are associated with hepatic injury. The effect of P. kurroa treatment on the antiproliferative response and, hepatic antioxidant enzymes of rats administered with 2-acetylaminofluorene (2-AAF) was studied in Wistar rats. 2-AAF (50 mg/kg body weight, i.p.) enhances hepatic lipid peroxidation, with reduction in hepatic glutathione content, glutathione peroxidase, glutathione reductase, catalase, and glutathione-s-transferase. There was an increase in the levels of transaminase enzymes and LDH. 2-AAF treatment also enhanced ornithine decarboxylase (ODC) activity and [3H] thymidine incorporation into hepatic DNA. Pretreatment of rats orally with P. kurroa extract (250 and 500 mg/kg body weight) resulted in significant decrease in lipid peroxidation, transaminase enzymes, LDH, hepatic ODC activity, and DNA synthesis (p < 0.001). Hepatic glutathione content (p < 0.001), glutathione metabolizing enzymes (p < 0.001), and antioxidant enzymes were also recovered to significant level (p < 0.001).