Enrichment of anaerobic heterotrophic thermophiles from four Azorean hot springs revealed different community composition and genera abundances using recalcitrant substrates

DGGE analysis combined with a metagenomic approach was used to get insights into heterotrophic anoxic enrichment cultures of four hot springs of Vale das Furnas, Portugal, using the recalcitrant substrate spent coffee ground (SCG). Parallel enrichment cultures were performed using the major components of spent coffee ground, namely arabinogalactan, galactomannan, cellulose, and proteins. DGGE revealed that heterotrophic thermophilic bacteria are highly abundant in the hydrothermal springs and significant differences in community composition depending on the substrate were observed. DNA, isolated from enrichment cultures of different locations that were grown on the same substrate were pooled, and the respective metagenomes were analyzed. Results indicated that cultures grown on recalcitrant substrate SCG consists of a totally different thermophilic community, dominated by Dictyoglomus. Enrichments with galactomannan and arabinogalactan were dominated by Thermodesulfovibrio, while cultures with casein and cellulose were dominated by Thermus. This study indicates the high potential of thermophilic bacteria degrading recalcitrant substrate such as SCG and furthermore how the accessibility to complex polymers shapes the bacterial community.

     

Seropositivity and Serointensity of Toxoplasma gondii Antibodies and DNA among Patients with Schizophrenia

The aim of this cross sectional case control study was to examine the serofrequency and serointensity of Toxoplasma gondii (Tg) IgG, IgM, and DNA among patients with schizophrenia. A total of 101 patients with schizophrenia and 55 healthy controls from Sungai Buloh Hospital, Selangor, Malaysia and University Malaya Medical Center (UMMC) were included in this study. The diagnosis of schizophrenia was made based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The presence of Tg infection was examined using both indirect (ELISA) and direct (quantitative real-time PCR) detection methods by measuring Tg IgG and IgM and DNA, respectively. The serofrequency of Tg IgG antibodies (51.5%, 52/101) and DNA (32.67%, 33/101) among patients with schizophrenia was significantly higher than IgG (18.2%, 10/55) and DNA (3.64%, 2/55) of the controls (IgG, P=0.000, OD=4.8, CI=2.2-10.5; DNA, P=0.000, OD=12.9, CI=2.17-10.51). However, the Tg IgM antibody between patients with schizophrenia and controls was not significant (P>0.005). There was no significant difference (P>0.005) in both serointensity of Tg IgG and DNA between patients with schizophrenia and controls. These findings have further demonstrated the strong association between the active Tg infection and schizophrenia.     

Effects of indomethacin on intestinal secretion, prostaglandin E and cyclic AMP: Evidence against a role for prostaglandins in cholera toxin-induced secretion

The effects of indomethacin on intestine mucosal cAMP, intestinal fluid secretion, and mucosal and fluid PGE were studied in rabbits in vivo following challenge with cholera toxin. Indomethacin had no effect on cholera toxin-induced fluid secretion or cAMP accumulation. Inhibition of PGE synthesis was achieved by the administration of two but not one injection of indomethacin. These studies provide evidence against a role for PGE in mediating cholera toxin-induced secretion and point out the need to measure prostaglandin levels when using prostaglandin synthetase inhibitors in vivo.     

The role of transmembrane sodium gradient in rabbit ileal smooth muscle: Utilization of harmaline

Decreasing extracellular sodium concentration was found to produce a contractile response of rabbit ileal smooth muscle. As the concentration decreases, the amplitude of contraction increases, thus producing a dose-dependent curve. Harmaline, a competitor for sodium, was found to inhibit the sodium gradient-dependent contractions in a dose-dependent manner. The results are interpreted as harmaline inhibiting a Na–Ca exchange mechanism present in ileal smooth muscle.     

Helicobacter suis KB1 derived from pig gastric lymphoid follicles induces the formation of gastric lymphoid follicles in mice through the activation of B cells and CD4 positive cells

"Helicobacter heilmannii" ("H. heilmannii"), which belongs to the genus Helicobacter, is a group of bacterial species that display a long spiral-shaped morphology. Recent studies have demonstrated that "H. heilmannii" type 1 is actually H. suis, which mainly colonizes the stomachs of various animals and humans. However, the influence of H. suis on gastric diseases remains to be fully elucidated. In this report, we revealed the relationship between natural H. suis infection and follicular gastritis in the pig stomachs. From sequence analysis of the 16S rRNA, urease A, and urease B genes, the presence of H. suis was confirmed in pig gastric lymphoid follicles, and this bacterium was named H. suis KB1. In addition, H. suis KB1 was inoculated into C57BL/6J mice, and the following mouse model of the pathogenesis of follicular gastritis by H. suis infection was established: H. suis KB1 colonizes the mouse stomach, and moreover, induces the development of lymphoid follicles and acquired immune responses characterized by the activation of B cells and CD4 positive cells. These results may lead to better understanding of the relationship between H. suis and gastric diseases, especially follicular gastritis; and furthermore, our findings emphasize the zoonotic aspects of animal-human infection by H. suis.     

Hypomorphic sialidase expression decreases serum cholesterol by downregulation of VLDL production in mice

Lipoprotein metabolism is an important contributing factor in the development and progression of atherosclerosis. Plasma lipoproteins and their receptors are heavily glycosylated and sialylated, and levels of sialic acids modulate their biological functions. Sialylation is controlled by the activities of sialyltranferases and sialidases. To address the impact of sialidase (neu1) activity on lipoprotein metabolism, we have generated a mouse model with a hypomorphic neu1 allele (B6.SM) that displays reduced sialidase expression and sialidase activity. The objectives of this study are to determine the impact of sialidase on the rate of hepatic lipoprotein secretion and lipoprotein uptake. Our results indicate that hepatic levels of cholesterol and triglycerides are significantly higher in B6.SM mice compared with C57Bl/6 mice; however, VLDL-triglyceride production rate is lower. In addition, B6.SM mice show significantly lower levels of hepatic microsomal triglyceride transfer protein (MTP) and active sterol-regulatory element binding protein (SREBP)-2 but higher levels of diglyceride acyltransferase (DGAT)2; these are all indicative of increased hepatic lipid storage. Rescue of sialidase activity in hypomorphic sialidase mice using helper-dependent adenovirus resulted in increased VLDL production and an increase in MTP levels. Furthermore, hypomorphic sialidase expression results in stabilization of hepatic LDL receptor (LDLR) protein expression, which enhances LDL uptake. These findings provide novel evidence for a central role of sialidase in the cross talk between the uptake and production of lipoproteins.     

Unmelanized plumage patterns in Old World leaf warblers do not correspond to sequence variation at the melanocortin-1 receptor locus (MC1R)

Evolutionary changes in patterns and coloration of plumage are likely to represent a major mechanism for speciation among birds, yet the molecular basis for such changes remains poorly understood. Recently much attention has focused on the melanocortin-1 receptor (MC1R) as a candidate locus for determining the level and extent of epidermal melanin deposition. We tested the hypothesis that MC1R sequence variation is associated with interspecific variation in unmelanized plumage pattern elements in Old World leaf warblers (genus Phylloscopus). This genus is characterized by a variety of plumage patterns that nonetheless vary along similar lines. Species vary in the presence or absence of pale (unmelanized) pattern elements against a dark background, and these patterns are used in species recognition and courtship. We sequenced most of the MC1R coding region for eight Phylloscopus species, representing the full range of plumage patterns found in this genus. Although MC1R sequence varied among species, this variation was not related to melanin-based plumage variation. Rather, evolution of this locus in these birds appears to be conservative. Ratios of nonsynonymous to synonymous substitutions (dN/dS) were consistently low, suggesting that strong purifying selection has operated at this locus, and likelihood ratio testing revealed no evidence of variable selective pressures among lineages or across codons. Adaptive evolution at MC1R may be constrained by the adaptive importance of plumage pattern elements in this genus.     

Haptoglobin release by human adipose tissue in primary culture

Haptoglobin is a putative adiposity marker because its concentration in blood is increased in obese humans. The present studies examined haptoglobin release by explants of adipose tissue in primary culture. Haptoglobin was released by explants of human visceral and subcutaneous adipose tissue at a nearly linear rate over 48 h. Explants of visceral adipose tissue released more haptoglobin than did explants of subcutaneous adipose tissue. The release of haptoglobin was quite variable, but there was a close correlation between haptoglobin release by visceral adipose tissue and that by explants of subcutaneous tissue from the same individual. Dexamethasone and niflumic acid, a cyclooxygenase-2 inhibitor, both inhibited haptoglobin release. There was release of haptoglobin by both isolated adipocytes and the adipose tissue matrix remaining after collagenase digestion of human adipose tissue. However, the amount of haptoglobin released by human adipose tissue explants in primary culture was quite low in relationship to the circulating level of haptoglobin.     

Propofol is cardioprotective in a clinically relevant model of normothermic blood cardioplegic arrest and cardiopulmonary bypass

The general anesthetic propofol has been shown to be cardioprotective. However, its benefits when used in cardioplegia during cardiac surgery have not been demonstrated. In this study, we investigated the effects of propofol on metabolic stress, cardiac function, and injury in a clinically relevant model of normothermic cardioplegic arrest and cardiopulmonary bypass. Twenty anesthetized pigs, randomized to propofol treatment (n = 8) and control (n = 12) groups, were surgically prepared for cardiopulmonary bypass (CPB) and cardioplegic arrest. Doses of warm blood cardioplegia were delivered at 15-min intervals during a 60-min aortic cross-clamped period. Propofol was continuously infused for the duration of CPB and was therefore present in blood cardioplegia. Myocardial biopsies were collected before, at the end of cardioplegic arrest, and 20 mins after the release of the aortic cross-clamp. Hemodynamic parameters were monitored and blood samples collected for cardiac troponin I measurements. Propofol infusion during CPB and before ischemia did not alter cardiac function or myocardial metabolism. Propofol treatment attenuated the changes in myocardial tissue levels of adenine nucleotides, lactate, and amino acids during ischemia and reduced cardiac troponin I release on reperfusion. Propofol treatment reduced measurable hemodynamic dysfunction after cardioplegic arrest when compared to untreated controls. In conclusion, propofol protects the heart from ischemia-reperfusion injury in a clinically relevant experimental model. Propofol may therefore be a useful adjunct to cardioplegic solutions as well as being an appropriate anesthetic for cardiac surgery.