Towards alpha- or beta-D-C-glycosyl compounds by tin-catalyzed addition of glycosyl radicals to acrylonitrile and vinylphosphonate,and flexible reduction of tetra-O-acetyl-alpha-D-glucopyranosyl bromide with cyanoborohydride

Photo-induced radical addition of acetylated alpha-D-glucopyranosyl bromide (1). to acrylonitrile or diethyl vinylphosphonate, in the presence of catalytic amounts of tri-n-butyltin chloride and sodium (or tetra-n-butylammonium) cyanoborohydride in excess, allowed efficient preparations of alpha-configurated nonononitrile and 2-(alpha-D-glucopyranosyl)-ethylphosphonate (79, 70% yields, respectively). These conditions led to 2-(alpha-D-manno-, and galactopyranosyl)-ethylphosphonates in 68 and 76% yields. Similarly, radical addition of acetylated 1-bromo-beta-D-glucopyranosyl chloride (2). to acrylonitrile or diethyl vinylphosphonate afforded mainly intermediate chlorides which, upon radical reduction with excess tri-n-butyltin hydride, afforded the corresponding beta anomers (40 and 38%, respectively) by sequential C-C and C-H bond formation. Stereocontrol relies on the alpha-stereoselective quenching of D-glycopyranos-1-yl radicals. We found also that UV light irradiation of 1 with excess NaBH(3)CN in tert-butanol afforded either 1,3,4,6-tetra-O-acetyl-2-deoxy-alpha-D-arabino-hexopyranose (65% after crystallization) or, when 10% mol thiophenol was added, 2,3,4,6-tetra-O-acetyl-1,5-anhydro-D-glucitol (79%). These are simple, tin-free, and easily controlled conditions, which compare well with known preparations of these reduced sugars.     

Helicobacter pylori Omp18 and Its Application in Serologic Screening of Infection

Helicobacter pylori (Hp) is a major risk factor for gastrointestinal disorders including gastric cancer. We evaluated host serum antibody responses toward outer membrane protein18 in comparison with Urease A and B subunits. omp18 and ureA-ureB gene fragments were PCR amplified, cloned, and expressed in E. coli expression system. The expressed proteins were visualized on SDS-PAGE and confirmed by immuno-blotting. Purified proteins were applied in western blotting assays in comparison with local and foreign ELISA kits. ROC curve analysis identified the optimum cut-off points for each protein. rOmp18 represented the highest rates of sensitivity (94%), specificity (89%), PPV (97.4%), NPV (77.4%), and accuracy (93.2%) in comparison with urease A and B subunits. These immunologic indices were in ??substantial?? agreement (???=?0.7) with the gold standard tests for Hp detection. This study recommends Hp conserved Omp18 as a reliable serologic marker for accurate detection of Hp infection particularly for application in population screening approaches.     

Myricetin loaded in solid lipid nanoparticles induces apoptosis in the HT-29 colorectal cancer cells via mitochondrial dysfunction

Molecular Biology Reports - Among the flavonoids, Myricetin (MCN) has negligible side effects and anti-cancer properties. However, the therapeutic potential of MCN has been limited mainly by its...     

Petroleum Degradation,Biosurfactant and Laccase Production by Fusarium neocosmosporiellum RH-10: A Microcosm Study

The aim of this study was to evaluate the potential of crude oil removal by fungal strains isolated from Arak refinery. The results showed that the RH10 strain is a potent strain as a surfactant producer and degrader of petrochemical hydrocarbons. The strain was identified as a Fusarium neocosmosporiellum and could degrade 58% of hydrocarbons in the minimal medium and reduce the surface tension from 45 to 26.5 mN m^?1. Moreover, residual crude oil analysis with Fourier transform infrared spectrophotometry showed that this strain was able to degrade 50% of aliphatic compounds. To investigate the mechanism of degradation, oxidase enzymes were assayed and it was found that F. neocosmosporiellum can produce 1.94 U L^?1 of laccase in 10 g L^?1 crude oil. Carbon, nitrogen, phosphorus and soil pattern optimization in a microcosm study showed that this strain removed 44% and 27% of the crude oil from contaminated soil in 1% and 5% crude oil concentrations, respectively. Under optimum condition, 9.66 g kg^?1 crude oil was removed by F. neocosmosporiellum when the initial oil concentration was 50 g kg^?1, at the end of 150 days microcosm experiment. The results demonstrated the promising potential of fungi strain for cleaning of contaminated soil.     

Thrombospondin 2 deficiency in pregnant mice results in premature softening of the uterine cervix

The gradual disorganization of collagen fibers in the stromal connective tissue of the uterine cervix is characteristic of progressive cervical softening during pregnancy. A lack of thrombospondin (TSP) 2 has been shown to be associated with altered collagen fibril morphology of connective-tissue-rich organs such as skin and tendon. The goal of this study was to determine the role of TSP2 in cervical softening by studying a TSP2-null mouse line. Creep testing showed that, in the nonpregnant animal and on Day 10 of pregnancy, there was no difference between the cervical extensibility of the wild-type and the TSP2-deficient mice. However, by Day 14 of pregnancy, the TSP2-null mice showed 4.5-fold increase in cervical extensibility, and by Day 18, a 6.1-fold increase, when compared with wild-type mice. A further indicator of compromised cervical integrity was that, on Days 14 and 18 of pregnancy, the cervix of TSP2-null mice broke rapidly under standard loading conditions that did not break the cervix of wild-type mice. Western blotting showed that TSP2 was expressed in the cervix of mice on Days 14 and 18 of pregnancy but not on Day 10 or in the nonpregnant animal. As determined by immunohistochemistry, the amount of matrix metalloproteinase 2 (MMP2) in the cervix of TSP2-null mice increased 11-fold on Day 14 of pregnancy and 19-fold on Day 18. Thus, TSP2-null mice provide an animal model to assist in the understanding of the molecular basis of spontaneous, premature softening of the uterine cervix.     

Effect of atriopeptin on the adrenergic mechanism regulating blood vessel tonus

The direct action of atriopeptin on the cell regulation mechanism of the smooth muscle in isolated segments of the portal vein, aorta, pancreatic and cerebral arteries have been studied. It was found that atriopeptin induce the direct relaxation of the smooth muscle in the main vessels only (aorta, portal vein). In the cerebral and pancreatic arteries atriopeptin stops norepinephrine-induced contractions. The data obtained show that the action of the atriopeptin is mediated by Na+-K+ pump activation of smooth muscle cells and restricts vasoconstriction of catecholamine effect.     

Orthotopic Small Bowel Transplantation in Rats

Small bowel transplantation has become an accepted clinical option for patients with short gut syndrome and failure of parenteral nutrition (irreversible intestinal failure). In specialized centers improved operative and managing strategies have led to excellent short- and intermediate term patient and graft survival while providing high quality of life ^1,3. Unlike in the more common transplantation of other solid organs (i.e. heart, liver) many underlying mechanisms of graft function and immunologic alterations induced by intestinal transplantation are not entirely known^6,7. Episodes of acute rejection, sepsis and chronic graft failure are the main obstacles still contributing to less favorable long term outcome and hindering a more widespread employment of the procedure despite a growing number of patients on home parenteral nutrition who would potentially benefit from such a transplant. The small intestine contains a large number of passenger leucocytes commonly referred to as part of the gut associated lymphoid system (GALT) this being part of the reason for the high immunogenity of the intestinal graft. The presence and close proximity of many commensals and pathogens in the gut explains the severity of sepsis episodes once graft mucosal integrity is compromised (for example by rejection). To advance the field of intestinal- and multiorgan transplantation more data generated from reliable and feasible animal models is needed. The model provided herein combines both reliability and feasibility once established in a standardized manner and can provide valuable insight in the underlying complex molecular, cellular and functional mechanisms that are triggered by intestinal transplantation. We have successfully used and refined the described procedure over more than 5 years in our laboratory ^8-11. The JoVE video-based format is especially useful to demonstrate the complex procedure and avoid initial pitfalls for groups planning to establish an orthotopic rodent model investigating intestinal transplantation.     

Effects of Combined Exposure to Chronic High-Fat Diet and Arsenic on Thyroid Function and Lipid Profile in Male Mouse

The thyroid is one of the major endocrine glands that contribute to body and fat metabolism. The present study evaluated the effects of combined exposure to chronic high-fat diet (HFD) and arsenic on thyroid function and lipid profile. In this experimental study, 72 male Naval Medical Research Institute mice were divided into six groups and fed HFD or low-fat diet (LFD) while being exposed to 25 or 50 ppm of arsenic in drinking water for 20 weeks. After 24 h of the last experimental day, blood samples were collected for hormonal and biochemical measurements. The data indicated that exposure to HFD alone increased the levels of triiodothyronine (T3), thyroid-stimulating hormone (TSH), leptin, lipid profile, reactive oxygen species (ROS), and malondialdehyde (MDA) and decreased the levels of high-density lipoprotein, albumin, adiponectin, and glutathione sulfhydryl reductase (GSH), whereas exposure to arsenic alone decreased the levels of T3 and GSH and increased the levels of TSH, leptin, ROS, MDA, and T4/T3 ratio compared to those in the control LFD group. Furthermore, concomitant administration of HFD and arsenic decreased the lipid profile and levels of T4, albumin, total protein, T3, and GSH and increased the levels of TSH, adiponectin, leptin, ROS, MDA, and T4/T3 ratio compared to those in the control LFD or HFD group. In conclusion, combined exposure to HFD and arsenic induced hypothyroidism via reduction of thyroid hormones and enhancement of plasma TSH and T3 uptake levels concomitant with hypolipidemia, hyperleptinemia, hyperadiponectinemia, induction of oxidative stress, and reduction of GSH levels.     

Xylan-hydrolyzing thermotolerant <Emphasis Type="Italic">Candida tropicalis</Emphasis> HNMA-1 for bioethanol production from sugarcane bagasse hydrolysate

Sugarcane bagasse is one of the low-cost substrates used for bioethanol production. In order to solubilize sugars in hemicelluloses like xylan, a new thermotolerant isolate of Candida tropicalis HNMA-1 with xylan-hydrolyzing ability was identified and characterized. The strain showed relative tolerance to high temperature. Our results demonstrated 0.211 IU ml^?1 xylanase activity at 40 °C compared to 0.236 IU ml^?1 at 30 °C. The effect of high temperature on the growth and fermentation of xylose and sugarcane bagasse hydrolysate were also investigated. In both xylose or hydrolysate medium, increased growth was recorded at 40 °C. Meanwhile, the efficiency of ethanol fermentation was adversely affected by temperature since yields of 0.088 g g^?1 and 0.076 g g^?1 in the xylose medium, in addition to 0.090 g g^?1 and 0.078 g g^?1 in the hydrolysate medium were noticed at 30 °C and 40 °C, respectively. Inhibitory compounds in the hydrolysate medium demonstrated negative effects on fermentation and productivity, with maximum ethanol concentration attained after 48 h in the hydrolysate, as opposed to 24 h in the xylose medium. Our data show that the newly thermotolerant isolate, C. tropicalis HNMA-1, is able to efficiently ferment xylose and hydrolysate, and also has the capacity for application in ethanol production from hemicellulosic sources.     

Hypoxia-induced expression of complement receptor type 1(CR1, CD35) in human vascular endothelial cells

Reoxygenation of hypoxic human umbilical vein endothelial cells(HUVECs) increases protein expression of the complement regulators CD46and CD55. As the receptor for C3b is known to be present on injuredbovine endothelial cells, we investigated whether hypoxia or inflammatory mediators induce complement receptor type 1 (CR1; CD35) expression on HUVECs. CR1 protein expressionincreased 3.7 ± 0.6-fold as measured by ELISA on HUVECsfollowing hypoxia (48 h, 1%O₂). Colocalization of CD35 andvon Willebrand factor by confocal microscopy confirmed that CD35 waspredominantly intracellular. Lipopolysaccharide or tumor necrosisfactor- also significantly increased HUVEC CR1 proteinexpression. Western blot analysis of neutrophil or hypoxicHUVEC lysates revealed a 221-kDa CR1 band under nonreducingconditions. RT-PCR of hypoxic HUVEC mRNA revealed a singleband that, after sequencing, was identified as CD35. In situhybridization of hypoxic HUVECs, but not normoxic HUVECs or fibroblasts, demonstrated increased CD35 mRNA.Hypoxic HUVECs bound immune complexes and acted as a cofactorfor factor I-mediated cleavage of C3b. Thus hypoxia induces functionalHUVEC CR1 expression.