Hepatitis B Surface Antigen Concentrations in Patients with HIV/HBV Co-Infection

HBsAg clearance is associated with clinical cure of chronic hepatitis B virus (HBV) infection. Quantification of HBsAg may help to predict HBsAg clearance during the natural course of HBV infection and during antiviral therapy. Most studies investigating quantitative HBsAg were performed in HBV mono-infected patients. However, the immune status is considered to be important for HBsAg decline and subsequent HBsAg loss. HIV co-infection unfavorably influences the course of chronic hepatitis B. In this cross-sectional study we investigated quantitative HBsAg in 173 HBV/HIV co-infected patients from 6 centers and evaluated the importance of immunodeficiency and antiretroviral therapy. We also compared 46 untreated HIV/HBV infected patients with 46 well-matched HBV mono-infected patients. HBsAg levels correlated with CD4 T-cell count and were higher in patients with more advanced HIV CDC stage. Patients on combination antiretroviral therapy (cART) including nucleos(t)ide analogues active against HBV demonstrated significant lower HBsAg levels compared to untreated patients. Importantly, HBsAg levels were significantly lower in patients who had a stronger increase between nadir CD4 and current CD4 T-cell count during cART. Untreated HIV/HBV patients demonstrated higher HBsAg levels than HBV mono-infected patients despite similar HBV DNA levels. In conclusion, HBsAg decline is dependent on an effective immune status. Restoration of CD4 T-cells during treatment with cART including nucleos(t)ide analogues seems to be important for HBsAg decrease and subsequent HBsAg loss.     

On architectures of circuits implemented in simulated Belousov-Zhabotinsky droplets

When lipid vesicles filled with Belousov-Zhabotinsky (BZ) excitable chemical medium are packed in tight assembles, waves of excitation may travel between the vesicles. When several waves meet in a vesicle some fragments may deflect, others can annihilate or continue their travel undisturbed. By interpreting waves as Boolean values we can construct logical gates and assemble them in large circuits. In numerical modelling we show two architectures of one-bit half-adders implemented in BZ-vesicles.     

Application of high-resolution,massively parallel pyrosequencing for estimation of haplotypes and gene expression levels of swine leukocyte antigen (<Emphasis Type="Italic">SLA</Emphasis>) class I genes

The swine is an important animal model for allo- and xeno-transplantation donor studies, which necessitates an extensive characterization of the expression and sequence variations within the highly polygenic and polymorphic swine leukocyte antigen (SLA) region. Massively parallel pyrosequencing is potentially an effective new 2ndGen method for simultaneous high-throughput genotyping and detection of SLA class I gene expression levels. In this study, we compared the 2ndGen method using the Roche Genome Sequencer 454 FLX with the conventional method using sub-cloning and Sanger sequencing to genotype SLA class I genes in five pigs of the Clawn breed and four pigs of the Landrace breed. We obtained an average of 10.4 SLA class I sequences per pig by the 2ndGen method, consistent with the inheritance data, and an average of only 6.0 sequences by the conventional method. We also performed a correlation analysis between the sequence read numbers obtained by the 2ndGen method and the relative expression values obtained by quantitative real-time PCR analysis at the allele level. A significant correlation coefficient (r = 0.899, P < 0.01) was observed between the sequence read numbers and the relative quantitative values for the expressed classical SLA class I genes SLA-1, SLA-2, and SLA-3, suggesting that the sequence read numbers closely reflect the gene expression levels in white blood cells. Overall, five novel class I sequences, different haplotype-specific expression patterns and a splice variant for one of the SLA class I genes were identified by the 2ndGen method at greater efficiency and sensitivity than the conventional method.     

Centrally acting leptin induces a resuscitating effect in haemorrhagic shock in rats

Centrally acting leptin induces the activation of the sympathetic nervous system with a pressor effect in normotensive rats. The purpose of the study was to examine central leptin-evoked action in critical haemorrhagic hypotension. In anaesthetized male Wistar rats subjected for irreversible haemorrhagic shock with mean arterial pressure (MAP) 20-25 mmHg haemodynamic parameters and plasma concentrations of adrenaline and noradrenaline were measured. Leptin given intracerebroventricularly (20 μg) evoked long-lasting rises in MAP and heart rate (HR), with a subsequent increase in renal, mesenteric and hindquarters blood flows and a 100% survival at 2 h. MAP and peripheral blood flow changes were inhibited by a pre-treatment with α(1)- and α(2)-adrenoceptor antagonists prazosin (0.5 mg/kg) and yohimbine (1 mg/kg), while β-adrenoceptor antagonist propranolol (1 mg/kg) blocked leptin-induced HR changes, without influence on MAP, peripheral blood flows and survival. Twenty min after leptin treatment, there were higher plasma concentrations of noradrenaline, but not adrenaline, in comparison with the saline-treated control group. In conclusion, centrally acting leptin induces a long-lasting pressor effect with an improvement in the survival rate in haemorrhage-shocked rats. The effect may be associated with the activation of the sympathetic nervous system.     

Decrease in salivary lactoferrin output in chronically intoxicated alcohol-dependent patients

Salivary lactoferrin is a glycoprotein involved in the elimination of pathogens and the prevention of massive overgrowth of microorganisms that affect oral and general health. A high concentration of lactoferrin in saliva is often considered to be a marker of damage to the salivary glands, gingivitis, or leakage through inflamed or damaged oral mucosa, infiltrated particularly by neutrophils. We conducted a study to determine the effect of chronic alcohol intoxication on salivary lactoferrin concentration and output. The study included 30 volunteers consisting of ten non-smoking male patients after chronic alcohol intoxication (group A), and 20 control nonsmoking male social drinkers (group C) with no history of alcohol abuse. Resting whole saliva was collected 24 to 48 hours after a chronic alcohol intoxication period. Lactoferrin was assessed by enzyme-linked immunosorbent assay. For all participants, the DMFT index (decayed, missing, or filled teeth), gingival index (GI) and papilla bleeding index (PBI) were assessed. The differences between groups were evaluated using the Mann-Whitney U test. We noticed significantly decreased salivary flow (SF) in alcohol dependent patients after chronic alcohol intoxication (A), compared to the control group (C). Although there was no significant difference in salivary lactoferrin concentration between the alcohol dependent group A and the control group C, we found significantly decreased lactoferrin output in group A compared to group C. We found a significant correlation between the amount of daily alcohol use and a decrease in lactoferrin output. There was a significant increase in GI and a tendency of PBI to increase in group A compared to group C. We demonstrated that chronic alcohol intoxication decreases SF and lactoferrin output. The decreased lactoferrin output in persons chronically intoxicated by alcohol may be the result of lactoferrin exhaustion during drinking (due to its alcohol-related lower biosynthesis or higher catabolism) or to decreased function of neutrophils affected by the ethanol. The poorer periodontal state in alcohol dependent persons compared to controls may be a result of lower salivary flow and decreased protection of the oral cavity by lactoferrin.     

Effect of selenite on basic mitochondrial function in human osteosarcoma cells with chronic mitochondrial stress

Mitochondrial chronic stress that originates from defective mitochondria is implicated in a growing list of human diseases. To enhance understanding of pathophysiology of chronic mitochondrial dysfunction we investigated human osteosarcoma cells with 2 types of chronic stress: corresponding to the mutation in ATP synthase subunit 6 encoded by mtDNA (NARP syndrome-mild stress) and to a total lack of mtDNA (Rho0 cells-heavy stress). We previously found that selenium influenced mitochondrial stress response and lowered ROS production. Therefore, in this study effect of selenite on other mitochondrial parameters was investigated. We showed that presence of selenium improved survival of starved cells, modified organization of mitochondrial network in NARP cybrids and decreased cytosolic calcium level in NARP and Rho0 cells. Selenium did not affect mitochondrial membrane potential, ATP level, activity of ATP synthase and activity of complex II of the respiratory chain.     

Evaluation of natural and nitramine binding energies to 3-D models of the S1S2 domains in the <Emphasis Type="Italic">N</Emphasis>-methyl-<Emphasis Type="SmallCaps">D</Emphasis>-aspartate receptor

Overactivation of the N-methyl-D-aspartate receptor (NMDAR) in postsynaptic neurons leads to glutamate-related excitotoxicity in the central nervous system of mammals. We have built 3-D models of each domain for the universal screening of potential toxicants and their binding mechanisms. Our docking results show that the calculated pK _i values of glycine and L-glutamate significantly increase (>1) when the NR1 and NR2A S1S2 domains are closing, respectively. Inversely, D-cycloserine (DCS) and 5,7-dichlorokynurenic acid (5,7-DCKA) do not show such a dependence on domain closure. Replica exchange molecular dynamics (REMD) confirmed 5 different conformational states of the S1S2 domain along the 308.2 K temperature trajectory. Analysis of residue fluctuations during this temperature trajectory showed that residues in loop 1, loop 2, the amino terminal domain (ATD), and the area linked to ion channel α-helices are involved in this movement. This further implicates the notion that efficacious ligands act through S1S2 lobe movement which can culminate in the opening or closing of the ion channel. We further tested this by docking hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) to the S1S2 domain. Our results predict that these nitramines are not efficacious and thus do not produce excitoxicity when they bind to the S1S2 domain of the NMDAR.     

Molecular simulations of adsorption of RDX and TATP on IRMOF-1(Be)

The influence of different sorption sites of isoreticular metal-organic frameworks (IRMOFs) on interactions with explosive molecules is investigated. Different connector effects are taken into account by choosing IRMOF-1(Be) (IRMOF-1 with Zn replaced by Be), and two high explosive molecules: 1,3,5-trinitro-s-triazine (RDX) and triacetone triperoxide (TATP). The key interaction features (structural, electronic and energetic) of selected contaminants were analyzed by means of density functional calculations. The interaction of RDX and TATP with different IRMOF-1(Be) fragments is studied. The results show that physisorption is favored and occurs due to hydrogen bonding, which involves the C-H groups of both molecules and the carbonyl oxygen atoms of IRMOF-1(Be). Additional stabilization of RDX and TATP arises from weak electrostatic interactions. Interaction with IRMOF-1(Be) fragments leads to polarization of the target molecules. Of the molecular configurations we have studied, the Be-O-C cluster connected with six benzene linkers (1,4-benzenedicarboxylate, BDC), possesses the highest binding energy for the studied explosives (-16.4 kcal mol(-1) for RDX and -12.9 kcal mol(-1) for TATP). The main difference was discovered to be in the preferable adsorption site for adsorbates (RDX above the small and TATP placed above the big cage). Based on these results, IRMOF-1 can be suggested as an effective material for storage and also for separation of similar explosives. Hydration destabilizes most of the studied adsorption systems by 1-3 kcal mol(-1) but it leads to the same trend in the binding strength as found for the non-hydrated complexes.