Bone mineral density and body composition in men with multiple sclerosis chronically treated with low-dose glucocorticoids

The aim of the study was to compare the bone mineral density (BMD) and body composition between ambulatory male MS patients and control subjects and to evaluate the relationships among body composition, motor disability, glucocorticoids (GC) use, and bone health. Body composition and BMD were measured by dual-energy X-ray absorptiometry in 104 ambulatory men with MS (mean age: 45.2 years) chronically treated with low-dose GC and in 54 healthy age-matched men. Compared to age-matched controls, MS patients had a significantly lower total body bone mineral content (TBBMC) and BMD at all measured sites except for the radius. Sixty five male MS patients (62.5 %) met the criteria for osteopenia and twenty six of them (25 %) for osteoporosis. The multivariate analysis showed a consistent dependence of bone measures (except whole body BMD) on BMI. The total leg lean mass % was as an independent predictor of TBBMC. The Expanded Disability Status Scale (EDSS), cumulative GC dose and age were independent determinants for BMD of the proximal femur. We conclude that decreasing mobility in male MS patients is associated with an increasing degree of osteoporosis and muscle wasting in the lower extremities. The chronic low-dose GC treatment further contributes to bone loss.     

The effect of intracerebral mesenchymal stem cells transplantation on the density of microvascular network of the pial matter of the rat brain cortex

Using a TV installation for studying the microcirculation (with 30-160-fold magnification), the density of microvascular network in the pia matter of the rat brain sensomotor cortex was determined after intracerebral transplantation of mesenchymal stem cells (MSC) or (as control) of the MSC cultivation nutrition medium, or of saline. The results have shown that intracerebral transplantation does not change density of microvascular network in the pia mater of the ipsilateral hemisphere. Transplantation of the MSC led to a 1.8-fold increase of density of the pia matter of the contralateral hemisphere as compared with control animals; the number of arterioles in the same zone was 2.5-fold higher than in intact rats.     

Phospholipids and structural modification of tissues and cell membranes for adaptation in high altitude mountains

The nature of the impact of physical factors of high altitudes (3200 m) on the lipids of tissues and membranes of animals was researched. It was established that the adaptation process in Wistar rats was followed by peroxide degradation and subsequent modification of the phospholipids' structure of tissues and microsomal membranes. Adaptive phospholipids reconstruction takes place in microsomal membranes in the tissues of the lungs, brain, liver and skeletal muscles. Together with this, the amount of phosphatidylinositol and phosphatidic acid accumulates, indicating that the hydrolysis of phosphatidylinositol-4, 5 biphosphate to diacylglycerol and secondary messenger--inositol triphosphate, occurs. A decrease in temperature adaptation (+10 degrees C) leads to a more noticeable shift in peroxide oxidation of lipids, phospholipid structure in the tissues and membranes rather than adaptation in thermoneutral conditions (+30 degrees C). Modification of lipid composition of tissues and cell membranes in the highlands obviously increases the adaptive capabilities of cells of the whole body: physical performance and resistance to hypoxia increases in animals.     

Resistance of neuroblastoma GI-ME-N cell line to glutathione depletion involves Nrf2 and heme oxygenase-1

Cancer cell survival is known to be related to the ability to counteract oxidative stress, and glutathione (GSH) depletion has been proposed as a mechanism to sensitize cells to anticancer therapy. However, we observed that GI-ME-N cells, a neuroblastoma cell line without MYCN amplification, are able to survive even if GSH-depleted by l-buthionine-(S,R)-sulfoximine (BSO). Here, we show that in GI-ME-N cells, BSO activates Nrf2 and up-regulates heme oxygenase-1 (HO-1). Silencing of Nrf2 restrained HO-1 induction by BSO. Inhibition of HO-1 and silencing of Nrf2 or HO-1 sensitized GI-ME-N cells to BSO, leading to reactive oxygen/nitrogen species overproduction and decreasing viability. Moreover, targeting the Nrf2/HO-1 axis sensitized GI-ME-N cells to etoposide more than GSH depletion. Therefore, we have provided evidence that in GI-ME-N cells, the Nrf2/HO-1 axis plays a crucial role as a protective factor against cellular stress, and we suggest that the inhibition of Nfr2/HO-1 signaling should be considered as a central target in the clinical battle against neuroblastoma.     

Mitochondrial aquaporin-8 in renal proximal tubule cells: evidence for a role in the response to metabolic acidosis

Mitochondrial ammonia synthesis in proximal tubules and its urinary excretion are key components of the renal response to maintain acid-base balance during metabolic acidosis. Since aquaporin-8 (AQP8) facilitates transport of ammonia and is localized in inner mitochondrial membrane (IMM) of renal proximal cells, we hypothesized that AQP8-facilitated mitochondrial ammonia transport in these cells plays a role in the response to acidosis. We evaluated whether mitochondrial AQP8 (mtAQP8) knockdown by RNA interference is able to impair ammonia excretion in the human renal proximal tubule cell line, HK-2. By RT-PCR and immunoblotting, we found that AQP8 is expressed in these cells and is localized in IMM. HK-2 cells were transfected with short-interfering RNA targeting human AQP8. After 48 h, the levels of mtAQP8 protein decreased by 53% (P < 0.05). mtAQP8 knockdown decreased the rate of ammonia released into culture medium in cells grown at pH 7.4 (-31%, P < 0.05) as well as in cells exposed to acid (-90%, P < 0.05). We also evaluated mtAQP8 protein expression in HK-2 cells exposed to acidic medium. After 48 h, upregulation of mtAQP8 (+74%, P < 0.05) was observed, together with higher ammonia excretion rate (+73%, P < 0.05). In vivo studies in NH(4)Cl-loaded rats showed that mtAQP8 protein expression was also upregulated after 7 days of acidosis in renal cortex (+51%, P < 0.05). These data suggest that mtAQP8 plays an important role in the adaptive response of proximal tubule to acidosis possibly facilitating mitochondrial ammonia transport.     

A Capillary Fraction Collector Coupled to a Fluorescence Reader: A Novel Device to Continuously Quantify Glutamate During Microdialysis

Microdialysis coupled to HPLC is the preferred method for quantification of glutamate (Glu) concentrations, both in normal and pathological conditions. However, HPLC is a time consuming technique that suffers from poor temporal resolution. Here we describe an alternative method to measure glutamate concentrations in small-volume dialysis samples by quantifying hydrogen peroxide released by glutamate oxidase using the Amplex Red method. This system permits continuous automatic sample collection and the detection of a fluorescent reaction product, resorufin, which provides a measure of the glutamate concentration. Quantification can be carried out in small microdialysis samples to allow a temporal resolution of 60 s. Both in vitro and in vivo tests showed that this method was reproducible and reliable, detecting Glu along a linear scale. To validate the proposed method, extracellular Glu concentrations in the rat brain were measured and correlated with electrophysiological activity prior, during and after seizure induction with 4-aminopyridine. This method may be adapted to monitor other biologically active compounds, including acetylcholine and glucose, as well as other compounds that generate hydrogen peroxide as a reaction product and may be used as an alternative to other neurochemical methods.     

Probiotic genomic DNA reduces the production of pro-inflammatory cytokine tumor necrosis factor-alpha

The effect of Lactobacillus plantarum genomic DNA on lipopolysaccharide (LPS)-induced mitogen-activated protein kinase (MAPK) activation, nuclear factor-kappa B activation, and the expressions of tumor necrosis factor-alpha, interleukin-1 receptor-associated kinase M, and the pattern recognition receptor were examined. Pretreatment of p-gDNA inhibited the phosphorylation of MAPKs and nuclear factor-kappa B, and also inhibited LPS-induced TNF-α production in response to subsequent LPS stimulation. L.?plantarum genomic DNA-mediated inhibition of signaling pathway and tumor necrosis factor-alpha was accompanied by the suppression of toll-like receptor (TLR) 2, TLR4, and TLR9 and the induction of interleukin-1 receptor-associated kinase M, a negative regulator of TLR. This study can extend our understanding of the biological function of probiotic genomic DNA as an anti-inflammatory agent.     

Evolutionary origin of the Asteraceae capitulum: Insights from Calyceraceae

? Premise of the study: Phylogenies based on molecular data are revealing that generalizations about complex morphological structures often obscure variation and developmental patterns important for understanding the evolution of forms, as is the case for inflorescence morphology within the well-supported MGCA clade (Menyanthaceae + Goodeniaceae + Calyceraceae + Asteraceae). While the basal families share a basic thyrsic/thyrsoid structure of their inflorescences, Asteraceae possesses a capitulum that is widely interpreted as a racemose, condensed inflorescence. Elucidating the poorly known inflorescence structure of Calyceraceae, sister to Asteraceae, should help clarify how the Asteraceae capitulum evolved from thyrsic/thyrsoid inflorescences. ? Methods: The early development and structure of the inflorescence of eight species (five genera) of Calyceraceae were studied by SEM, and patterns of evolutionary change were interpreted via phylogenetic character mapping. ? Key results: The basic inflorescence structure of Calyceraceae is a cephalioid (a very condensed botryoid/thyrsoid). Optimization of inflorescence characters on a DNA sequence-derived tree suggests that the Asteraceae capitulum derives from a simple cephalioid through two morphological changes: loss of the terminal flower and suppression of the cymose branching pattern in the peripheral branches. ? Conclusions: Widely understood as a condensed raceme, the Asteraceae capitulum is the evolutionary result of a very reduced, condensed thyrsoid. Starting from that point, evolution worked separately only on the racemose developmental control/pattern within Asteraceae and mainly on the cymose developmental control/pattern within Calyceraceae, producing head-like inflorescences in both groups but with very different diversification potential. We also discuss possible remnants of the ancestral cephalioid structure in some Asteraceae.     

The impact of population dynamics on Y-chromosome microsatellite Polymorphism. Mathematical modeling

In this article, we use mathematical modeling to study the impact of population dynamics on Y-chromosome STR-polymorphism accumulation in two independently evolving populations, namely, on the changes in genetic distance among the populations. Using two definitions of the genetic distance: (deltamu)2 and ASD, we carry out comparative research on the genetic distance changes and show that in contrast to (deltamu)2, ASD is characterized by a near-linear dependence on time. As the populations undergo oscillations, ASD is shown to be smaller than that in stationary populations. The linear dependence of ASD on time is shown to break down in relatively scanty stationary populations.