Bacterial Processes of the Methane Cycle in Bottom Sediments of Lake Baikal

The activity of methanogenic and methanotrophic bacteria was evaluated in bottom sediments of Lake Baikal. Methane concentration in Baikal bottom sediments varied from 0.0053 to 81.7 ml/dm³. Bacterial methane was produced at rates of 0.0004–534.7 l CH₄/(dm³ day) and oxidized at rates of 0.005–1180 l CH₄/(dm³ day). Peak methane production and oxidation were observed in Frolikha Bay near a methane vent. Methane was emitted into water at rates of 49.2–4340 l CH₄/(m² day). Rates of bacterial methane oxidation in near-bottom water layers ranged from 0.002 to 1.78 l/(l day). Methanogens and methanotrophs were found to play an important role in the carbon cycle through all layers of sediments, particularly in the areas of methane vent and gas-hydrate occurrence.     

The effect of temperature and pH on the growth of aerobic alkalithermophilic bacteria from hot springs in Buryatia

Growth parameters (temperature and pH) were determined for collection cultures of aerobic heterotrophic bacteria. Analysis of the experimental data with the use of the Rosso model made it possible to calculate the extreme values of temperature and pH permissive for culture growth. The examined cultures were subdivided into three groups with respect to their growth temperature and pH. The first group is represented by the cultures with minimum, maximum, and optimal growth temperatures of < 20, 60-64, and 38-40 degrees C, respectively, and with the optimal growth pH 8.0-8.5. Bacteria of the second group are true alkalithermophilic organisms with a temperature optimum of 45-50 degrees C and pH optimum of 8.5-9.0. The third group includes a culture of a thermophilic alkalitolerant bacterium.     

The PINE study: rationale and design of a randomised comparison of epidural injection of local anaesthetics and steroids versus care-as-usual to prevent postherpetic neuralgia in the elderly [ISRCTN32866390]

BACKGROUND: Postherpetic neuralgia (PHN) is by far the most common complication of herpes zoster (HZ) and one of the most intractable pain disorders. Since PHN is seen most often in the elderly, the number of patients with this disorder is expected to increase in our ageing society. PHN may last for months to years and has a high impact on the quality of life. The results of PHN treatment are rather disappointing. Epidural injection of local anaesthetics and steroids in the acute phase of HZ is a promising therapy for the prevention of PHN. Since randomised trials on the effectiveness of this intervention are lacking, the PINE (Prevention by epidural Injection of postherpetic Neuralgia in the Elderly) study was set up. The PINE study compares the effectiveness and cost-effectiveness of a single epidural injection of local anaesthetics and steroids during the acute phase of HZ with that of care-as-usual (i.e. antivirals and analgesics) in preventing PHN in elderly patients. METHODS / DESIGN: The PINE study is an open, multicenter clinical trial in which 550 elderly (age >/= 50 yr.) patients who consult their general practitioner in the acute phase of HZ (rash < 7 days) are randomised to one of the treatment groups. The primary clinical endpoint is the presence of HZ-related pain one month after the onset of the rash. Secondary endpoints include duration and severity of pain, re-interventions aiming to treat the existing pain, side effects, quality of life, and cost-effectiveness. CONCLUSION: The PINE study is aimed to quantify the (cost-) effectiveness of a single epidural injection during the acute phase of HZ on the prevention of PHN.     

Inverted Alu repeats unstable in yeast are excluded from the human genome

The nearly one million ALU: repeats in human chromosomes are a potential threat to genome integrity. ALU:s form dense clusters where they frequently appear as inverted repeats, a sequence motif known to cause DNA rearrangements in model organisms. Using a yeast recombination system, we found that inverted ALU: pairs can be strong initiators of genetic instability. The highly recombinagenic potential of inverted ALU: pairs was dependent on the distance between the repeats and the level of sequence divergence. Even inverted ALU:s that were 86% homologous could efficiently stimulate recombination when separated by <20 bp. This stimulation was independent of mismatch repair. Mutations in the DNA metabolic genes RAD27 (FEN1), POL3 (polymerase delta) and MMS19 destabilized widely separated and diverged inverted ALU:s. Having defined factors affecting inverted ALU: repeat stability in yeast, we analyzed the distribution of ALU: pairs in the human genome. Closely spaced, highly homologous inverted ALU:s are rare, suggesting that they are unstable in humans. ALU: pairs were identified that are potential sites of genetic change.     

ACUTE EFFECTS OF MOVEMENT VELOCITY ON BLOOD LACTATE AND GROWTH HORMONE RESPONSES AFTER ECCENTRIC BENCH PRESS EXERCISE IN RESISTANCE-TRAINED MEN

This study aimed to compare the effects of different velocities of eccentric muscle actions on acute blood lactate and serum growth hormone (GH) concentrations following free weight bench press exercises performed by resistance-trained men. Sixteen healthy men were divided into two groups: slow eccentric velocity (SEV; n = 8) and fast eccentric velocity (FEV; n = 8). Both groups performed four sets of eight eccentric repetitions at an intensity of 70% of their one repetition maximum eccentric (1RMecc) test, with 2-minute rest intervals between sets. The eccentric velocity was controlled to 3 seconds per range of motion for SEV and 0.5 seconds for the FEV group. There was a significant difference (P < 0.001) in the kinetics of blood lactate removal (at 3, 6, 9, 15, and 20 min) and higher mean values for peak blood lactate (P = 0.001) for the SEV group (9.1 ± 0.5 mM) compared to the FEV group (6.1 ± 0.4 mM). Additionally, serum GH concentrations were significantly higher (P < 0.001) at 15 minutes after bench press exercise in the SEV group (1.7 ± 0.6 ng · mL⁻¹) relative to the FEV group (0.1 ± 0.0 ng · mL⁻¹). In conclusion, the velocity of eccentric muscle action influences acute responses following bench press exercises performed by resistance-trained men using a slow velocity resulting in a greater metabolic stress and hormone response.     

Influence of age on the haemoglobin concentration of malaria-infected patients in a reference centre in the Brazilian Amazon

Anaemia is amongst the major complications of malaria, a major public health problem in the Amazon Region in Latin America. We examined the haemoglobin (Hb) concentrations of malaria-infected patients and compared it to that of malaria-negative febrile patients and afebrile controls. The haematological parameters of febrile patients who had a thick-blood-smear performed at an infectious diseases reference centre of the Brazilian Amazon between December 2009-January 2012 were retrieved together with clinical data. An afebrile community control group was composed from a survey performed in a malaria-endemic area. Hb concentrations and anaemia prevalence were analysed according to clinical-epidemiological status and demographic characteristics. In total, 7,831 observations were included. Patients with Plasmodium falciparum infection had lower mean Hb concentrations (10.5 g/dL) followed by P. vivax-infected individuals (12.4 g/dL), community controls (12.8 g/dL) and malaria-negative febrile patients (13.1 g/dL) (p < 0.001). Age, gender and clinical-epidemiological status were strong independent predictors for both outcomes. Amongst malaria-infected individuals, women in the reproductive age had considerably lower Hb concentrations. In this moderate transmission intensity setting, both vivax and falciparum malaria are associated with reduced Hb concentrations and risk of anaemia throughout a wide age range.     

Impact of folic acid fortification on global DNA methylation and one-carbon biomarkers in the Women's Health Initiative Observational Study cohort

DNA methylation is an epigenetic mechanism that regulates gene expression and can be modified by one-carbon nutrients. The objective of this study was to investigate the impact of folic acid (FA) fortification of the US food supply on leukocyte global DNA methylation and the relationship between DNA methylation, red blood cell (RBC) folate, and other one-carbon biomarkers among postmenopausal women enrolled in the Women's Health Initiative Observational Study. We selected 408 women from the highest and lowest tertiles of RBC folate distribution matching on age and timing of the baseline blood draw, which spanned the pre- (1994–1995), peri- (1996–1997), or post-fortification (1998) periods. Global DNA methylation was assessed by liquid chromatography-tandem mass spectrometry and expressed as a percentage of total cytosine. We observed an interaction (P = 0.02) between fortification period and RBC folate in relation to DNA methylation. Women with higher (vs. lower) RBC folate had higher mean DNA methylation (5.12 vs. 4.99%; P = 0.05) in the pre-fortification period, but lower (4.95 vs. 5.16%; P = 0.03) DNA methylation in the post-fortification period. We also observed significant correlations between one-carbon biomarkers and DNA methylation in the pre-fortification period, but not in the peri- or post-fortification period. The correlation between plasma homocysteine and DNA methylation was reversed from an inverse relationship during the pre-fortification period to a positive relationship during the post-fortification period. Our data suggest that (1) during FA fortification, higher RBC folate status is associated with a reduction in leukocyte global DNA methylation among postmenopausal women and; (2) the relationship between one-carbon biomarkers and global DNA methylation is dependent on folate availability.     

The role of glyceraldehyde 3-phosphate dehydrogenase (GapA-1) in <Emphasis Type="Italic">Neisseria meningitidis</Emphasis> adherence to human cells

Background  

Glyceraldehyde 3-phosphate dehydrogenases (GAPDHs) are cytoplasmic glycolytic enzymes, which although lacking identifiable secretion signals, have also been found localized to the surface of several bacteria (and some eukaryotic organisms); where in some cases they have been shown to contribute to the colonization and invasion of host tissues. Neisseria meningitidis is an obligate human nasopharyngeal commensal which can cause life-threatening infections including septicaemia and meningitis. N. meningitidis has two genes, gapA-1 and gapA-2, encoding GAPDH enzymes. GapA-1 has previously been shown to be up-regulated on bacterial contact with host epithelial cells and is accessible to antibodies on the surface of capsule-permeabilized meningococcal cells. The aims of this study were: 1) to determine whether GapA-1 was expressed across different strains of N. meningitidis; 2) to determine whether GapA-1 surface accessibility to antibodies was dependant on the presence of capsule; 3) to determine whether GapA-1 can influence the interaction of meningococci and host cells, particularly in the key stages of adhesion and invasion.