Spermatogenic and sperm quality differences in an experimental model of metabolic syndrome and hypogonadal hypogonadism

The synergistic effect of the co-morbidities that comprise metabolic syndrome (MetS) is increasingly being recognised as an important contributor in the pathology of a broad spectrum of seemingly disparate conditions. However, in terms of male reproductive function, beyond erectile dysfunction, little is known about the influence of this cohort (collectively or separately) on spermatogenesis and sperm quality. The aims of this study were to assess the reproductive tract of a MetS animal model for detrimental changes, to determine whether a group of compounds (advanced glycation end products and their receptor) known to cause cell dysfunction and DNA damage was present and assess whether hypogonadotropic hypogonadism was the main contributing factor for the changes seen. Animals fed a high-fat diet were found to have significantly increased cholesterol, triglycerides, blood glucose, mean arterial pressure and visceral fat levels. Although serum testosterone was decreased, no changes were seen in either testicular or epididymal histology. Immunolocalisation of N(ε)-carboxymethyl-lysine and the receptor for advanced glycation end products was found in the testes, epididymides and sperm of the two treated groups of animals; however, ELISA did not show any difference in protein levels. Similarly, assessment of sperm nuclear DNA (nDNA) fragmentation by acridine orange test did not find significant differences in nDNA integrity. We conclude that the minimal effect on spermatogenesis and sperm quality seen in our model is probably due to the moderate increase of blood glucose rather than the hypogonadism.     

DFT study of trichloroethene reaction with permanganate in aqueous solution

The mechanism of the environmentally important reaction between permanganate anion and trichloroethene (TCE) has been studied theoretically using modern DFT functional. It has been shown that IEFPCM/M05-2X/aug-cc-pVDZ theory level yields activation parameters and carbon isotopic fractionation factor in excellent agreement with the experimental data. Obtained results indicate that this reaction proceeds via the 3+2 mechanism with a very early transition state, in which the new C-O bonds are formed only in about 20%. An alternative, stepwise mechanism that involves initial formation of a single new C-O bond and a C-Mn bond, followed by rearrangement to the permanganate-TCE adduct, has been found to be more energetically demanding and in disagreement with the experimental isotopic fractionation.     

In vitro synthesis of biogenic amines by Brochothrix thermosphacta isolates from meat and meat products and the influence of other microorganisms

Twenty Brochothrix thermosphacta strains tested for biogenic amines (BAs) production, formed histamine (6.6-16.2 mg/kg) and tyramine (18.7-35.4 mg/kg) but neither putrescine nor cadaverine. Six of the twenty strains were also investigated in respect of their influence on the synthesis of BAs by Escherichia coli, Pseudomonas sp., Proteus mirabilis and Lactobacillus sakei. In pure culture Escherichia coli produced all of the studied amines (histamine, tyramine, putrescine and cadaverine) with a total concentration of 167.7 mg/kg, P. mirabilis produced a total of 56.7 mg/kg histamine, tyramine and cadaverine, while Lactobacillus sakei and Pseudomonas sp. produced histamine and tyramine, totaling 37.9 and 35.2 mg/kg respectively. All B. thermosphacta promoted cadaverine production by Escherichia coli which increased by 12-68%, and some of them contributed to the appearance of this amine among the metabolites of Pseudomonas. The presence of B. thermosphacta decreased the potential ability of P. mirabilis to produce BAs.     

Role of mitochondria in the switch mechanism of the cell death mode from apoptosis to necrosis--studies on rho0 cells

Detailed mechanisms of the switch of the cell death mode from apoptosis to necrosis remain to be solved, although the intracellular level of ATP and that of free radicals have been postulated to be the major factors involved in the mechanisms. In the present study menadione (MEN)-induced cell injury processes were studied using rho0 cells derived from human osteosarcoma 143B cells and parental rho+ cells co-treated with inhibitors of electron transfer chain of mitochondria or oligomycin, an inhibitor of ATP synthesis. Treatment of rho+ cells with 100 microM MEN induced apoptosis, which reached the maximum at 6 h, and was followed by an abrupt decrease thereafter, while necrotic cells (NC) increased continuously when they were judged by Annexin V and PI double staining. On the other hand, MEN induced apoptotic and necrotic changes much faster in rho0 cells compared to rho+ cells. The frequency to find apoptotic cells (AP) in the former cells was distinctly smaller than that to find NC judged by Annexin V and PI double staining. Electron microscopically, a major population of rho0 cells treated with MEN for 6 h consisted of intermediate cells, and a small number of AP co-existed. At 9 h of the treatment intermediate cells were exclusively seen, and AP were hardly detected. When parental rho+ cells were treated with MEN in the presence of oligomycin or oligomycin plus antimycin A both apoptotic and necrotic changes of the cells were distinctly accelerated. The intracellular level of superoxide in rho0 cells continuously increased after the MEN treatment, whereas that of ATP remained distinctly low before and after the MEN treatment compared to that in rho+ cells. These data suggest that the intracellular level of superoxide may be a key factor controlling the switch from apoptosis to necrosis.     

Physico-Chemical Properties of Cobalt–Ruthenium (10% Co–0.5% Ru) Catalysts Supported on Binary Oxides 8.5%ZrO<Subscript>2</Subscript>/Support (SiO<Subscript>2</Subscript>, Al<Subscript>2</Subscript>O<Subscript>3</Subscript>, TiO<Subscript>2</Subscript>) for Fischer-Tropsch Synthesis

The promotion of Fischer-Tropsch catalysts 10%Co/Al₂O₃, 10%Co/SiO₂, 10%Co/TiO₂ by 0.5% Ru and the modification of supports by 8.5 wt% ZrO₂ have been studied. The following properties: catalyst specific surface area as well as reducibility and dispersion of metallic phase were studied by different techniques: BET, TPR, and H₂ chemisorption. The modification of supports by non-reducible ZrO₂, results in a decrease of cobalt oxide reduction on Al₂O₃ and TiO₂ but not on SiO₂ supports. Additionally the enhancement of cobalt dispersion was found for all catalysts with ZrO₂ modified supports. The impact of Ru promotion is likely due to the stabilization of applied supports, prevention or blockage of interaction between surface Co species and support and an increase in cobalt oxide reducibility to the catalytically active metallic cobalt phase.     

Antioxidant activity and free radical‐scavenging capacity of ethanolic extracts of thyme,oregano, and marjoram

Phenolic compounds were extracted from thyme (Thymus vulgaris L.), oregano (Origanum vulgare L.) and marjoram (Origanum majorana L.) with 95% ethanol. A number of antioxidant and radical‐scavenging capacity tests were performed on the prepared extracts using colorimetric assays and model system studies. Specifically, these included determining the content of total phenolics, antioxidant efficacy in a linoleic acid‐ferric thiocyanate model system, reducing power, scavenging effect on 2,2'‐diphenyl‐1‐picrylhydrazyl radical, and hydroxyl radical‐scavenging activity by electron paramagnetic resonance spectroscopy. Moreover, the efficacies of the prepared herb extracts were investigated in a real‐life food product: the stabilization of butter against oxidation.     

Thermal stability of expanded perlite modified by mullite

Results of the thermal stability of expanded perlite modified by mullite are presented. Mullite was formed from alumino-silicate gel by sol–gel method. This method allowed us to obtain very homogenous and reactive gel and phase formation of mullite took place at relatively low temperatures. Expanded perlite modified with alumino-silicate gel after firing above the temperature of mullite formation had better thermal stability and durability during heating. The thermal stability of this material was examined up to 1400 °C.     

The influence of ageing of epoxy coatings on adhesion of polyurethane topcoats and protective properties of coating systems

The dependence of adhesion and protective properties of coating systems on surface properties of epoxy intermediate coatings, aged and non-aged before an application of polyurethane topcoats, were examined. The intermediate coatings were aged 500 h in UV chamber. The surface free energy and polar groups were estimated after ageing. After applying polyurethane topcoats on aged and non-aged epoxy coatings, resistance to salt spray and thermal shocks were tested as well as internal stresses were measured before and after corrosion tests.The results showed that adhesion in coating systems with polyurethane topcoats applied on aged epoxy coatings depends strongly on the degradation degree of epoxy intermediate coatings and the value of generated internal stresses. Coatings with good adhesion retention in corrosion environments have good protective properties even when temporary blistering has occurred.     

The importance of electrode material in environmental electrochemistry: Formation and reactivity of free hydroxyl radicals on boron-doped diamond electrodes

A model describing the hydroxyl radical (HO) concentration profile at the boron-doped diamond (BDD) electrode, in the presence and absence of organic compounds, is presented. It is shown that this profile depends strongly on the reaction rate constant between the HO and the organic compound. Furthermore, it is shown that the presence of organics affects the current-potential (I-V) curves. In fact, the higher the reaction rate between organics and HO, the higher is the shift of the I-V curves toward lower potential with respect to oxygen evolution. Supposing that water discharge to free hydroxyl radicals on BDD is governed by Nernst equation, this shift of the I-V curves toward lower potentials has been calculated and compared with the experimental data obtained on BDD using two model compounds: methanol and formic acid.