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New products of photo‐ and thermal rearrangements of 19‐membered azoxybenzocrown with phenyl substituents in benzene rings in the para positions to oligooxyethylene fragments are characterized in this work. The yields of photochemical transformations depend on the solvent. Para‐hydroxyazocrown is formed with yields over 50 % in propan‐2‐ol. Ortho‐hydroxyazobenzocrown is obtained with yields up to 70 % in toluene/acetic acid mixture. Macrocyclic Ph‐20‐ester is obtained in yield 90 % under thermochemical rearrangement conditions. Structure of new hydroxyazobenzocrowns and also atypical product of rearrangements, 20‐membered ester, was confirmed by X‐ray diffraction analysis. Azophenol←→ ${ \mathbin{{\stackrel{\textstyle\rightarrow} { {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}} } }} }$ quinone‐hydrazone tautomeric equilibrium of new hydroxyazobenzocrowns and the influence of metal cations on tautomeric equilibrium was investigated using 1H NMR and UV‐Vis spectroscopy in acetonitrile. The highest value of stability constant (logK 7.25) was obtained for strontium complex of p‐hydroxyazobenzocrown. For the first time p‐hydroxyazobenzocrown was used as a chromoionophore in the receptor layer of an optical sensor. Comparative analysis with data obtained previously for series 19‐membered analogs have shown the influence of the presence of substituents in benzene rings for the course and products distribution of photo and thermal rearrangement. The effect of substituents was also discussed against the tautomeric equilibrium and metal cation complexation properties. [ABSTRACT FROM AUTHOR]

Summary: The disaccharide trehalose is widely distributed in nature and can serve as a carbon reservoir, a signaling molecule for controlling glucose metabolism and a stress protectant. We demonstrated that in Escherichia coli ΔotsA cells, which are unable to synthesize trehalose, the aggregation of endogenous proteins during the stationary phase was increased in comparison to wild‐type cells. The lack of trehalose synthesis boosted Nε‐lysine acetylation of proteins, which in turn enhanced their hydrophobicity and aggregation. This increased Nε‐lysine acetylation could result from carbon overflow and the accumulation of acetyl phosphate caused by the ΔotsA mutation. These findings provide a better understanding of the previously reported protective functions of trehalose in protein stabilization and the prevention of protein aggregation. Our results indicate that trehalose may participate in proteostasis not only as a chemical chaperone but also as a metabolite that indirectly counteracts detrimental protein acetylation. We propose that trehalose protects E. coli against carbon stress – the synthesis and storage of trehalose can prevent carbon overflow, which otherwise is manifested by protein acetylation and aggregation. [ABSTRACT FROM AUTHOR]

Aims: The cardiotoxic effects of antimuscarinics constitute a significant restriction in their application in elderly people. Overactive bladder syndrome pharmacotherapy using compounds with cardioprotective properties would seem an ideal solution. The main goal of the study was to assess the impacts of nebivolol (NEB) on the activity of BRL 37344 — β3‐adrenergic receptor (β3AR) agonist, in the animal model of detrusor overactivity. As both these substances can impact on the cardiovascular system, their effect on the parameters of this system and diuresis was also examined. Methods: Retinyl acetate (RA; 0.75%) solution was used to induce detrusor overactivity in female Wistar rats. BRL and/or NEB were administered intra‐arterially during cystometry in a single dose (2.5 or 5, 0.05 or 0.1 mg/kg, respectively). In addition, a 24 hours measurement of heart rate, blood pressure, and urine production was carried out. Results: NEB (0.05 mg/kg) and BRL (2.5 mg/kg) monotherapy proved to have no influence on the cystometric parameters of animals with RA‐induced detrusor overactivity. NEB at 0.1 mg/kg resulted in a drop in the detrusor overactivity index, similarly to BRL at 5 mg/kg. Coadministration of NEB and BRL, both at ineffective doses, decreased the detrusor overactivity index and ameliorated the nonvoiding contractions. β3AR stimulation proved to induce tachycardia and hypertension. NEB at 0.05 mg/kg proved to ameliorate detrusor overactivity and have preventive properties against adverse cardiovascular effects of the β3AR agonist. Conclusions: The combined application of the β3AR agonist and NEB may improve detrusor overactivity without affecting the heart rate, blood pressure, and urine production. [ABSTRACT FROM AUTHOR]

Abstract: Hybrid and integrated membrane systems are often proposed as a way to increase the water recovery in desalination plants. Four different configurations of seawater desalination plants were compared: a standard single‐stage seawater reverse osmosis (SWRO), a hybrid SWRO‐electrodialysis (ED) system, a nanofiltration (NF)‐SWRO system, and an NF‐SWRO‐ED. Based on the laboratory results, the overall water recovery, energy consumption, scaling risk, and the composition of the generated waste brine were projected. An NF‐SWRO‐ED system was found as the best choice. The proposed system is able to produce highly concentrated brine, close to saturation with respect to sodium chloride. The brine can be further used in evaporated salt production or in the chlor‐alkali industry. [ABSTRACT FROM AUTHOR]

Objective. The aim of this study was to determine whether maternal serum matrix metalloproteinases 2, 3, 9, and 13 levels differ in early- and late-onset preeclampsia and uncomplicated pregnancies. Patients and Methods. The study was carried out in 125 pregnant women (29 with early-onset preeclampsia; 31 preeclamptic patients with late-onset preeclampsia; and 65 healthy pregnant controls). Levels of MMP-2, MMP-3, MMP-9, and MMP-13 were measured in the maternal serum using an enzyme-linked immunosorbent assay. Results. Maternal serum MMP-2 levels in both the groups of preeclamptic women were significantly higher than those in the controls. Levels of MMP-3 were significantly higher in preeclamptic patients with early-onset disease; however, the MMP-3 levels in patients with late-onset preeclampsia were similar to those observed in the control subjects. MMP-9 levels were lower whereas the levels of MMP-13 were higher in both preeclamptic groups of pregnant women than in the healthy controls, but these differences were statistically insignificant. Conclusions. One important finding of the present study was that MMP-3 appears to be involved solely in early-onset preeclampsia, but not in late-onset preeclampsia. Higher levels of MMP-2 and MMP-13 and lower levels of MMP-9 seem to be related to both early- and late-onset severe preeclampsia. [ABSTRACT FROM AUTHOR]

Background A major problem in the treatment of leukemia is the development of drug resistance to chemotherapeutic agents. Methods To determine the ex vivo drug resistance profile to anthracyclines, an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT) cytotoxicity assay was performed on mononuclear cells obtained from 155 patients with acute lymphoblastic leukemia (ALL) or acute myeloblastic leukemia (AML). Gene expression profiles (for 51 patients with ALL and 16 with AML) were prepared on the basis of cRNA hybridization to oligonucleotide arrays of the human genome (Affymetrix). Hierarchical clustering, assignment location and biological function were investigated during the correlation analysis for identified probe sets. Comparative genomic hybridization (CGH) array profiles (34 patients with ALL and 12 with AML) were prepared on the basis of DNA hybridization to oligonucleotide arrays of the human genome (Agilent). The validation of the array results was performed by a quantitative reverse transcriptase polymerase chain reaction. Results The collected expression and CGH microarray experiment results indicate that the ITGB2, SCL6A7, CASP1 and DUSP genes may comprise a resistance marker for acute leukemia cells correlated with anthracyclines. Moreover, there were also identified chromosome rearrangements associated with drug resistance, such as del5q32-35.3 and amp8p12-p11.21. Precise genes, as well as genome aberrations, might be classified as targets in therapy. Conclusions In AML, the resistance of blasts to idarubicin and mitoxantrone may reflect an impaired integrin pathway. In ALL, the development of resistance is caused by the inhibition of B and T cell activation. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Weather aging of nitrile rubber composites containing hydrophilic 1-ethyl-3-methylimidazolium thiocyanate (EMIM SCN) and hydrophobic 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI), and 1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (AMIM TFSI) ionic liquids was investigated. The mechanical properties at small (dynamic mechanical analysis) and high deformation (tensile test), the hardness and the electrical properties were measured before and after the aging process. It was found that the presence of hydrophobic ionic liquids in the nitrile rubber enhanced the retention of their mechanical properties (tensile strength, stiffness) and slightly reduced surface defects (as determined by scanning electron microscopy), thereby retarding the aging of rubber composites. However, the presence of hydrophilic EMIM SCN in the composite accelerated the degradation of the studied materials because of its high crosslinking activity during the aging process. The electrical studies showed also lower stability of hydrophilic ionic liquid (EMIM SCN) in the studied nitrile matrix (leaking effects) compared to the hydrophobic one (EMIM TFSI, AMIM TFSI). [ABSTRACT FROM AUTHOR]

We investigated the ability of three imidazolium ionic liquids (ILs) (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIM TFSI), 1-hexyl-methylimidazolium bis(trifluoromethylsulfonyl)imide (HMIM TFSI)) that have the same anion but different alkyl chain lengths of cation in amounts of 2.5, 5, 10 and 15 phr (parts per hundred rubber)to improve the ionic conductivity of carboxylated nitrile butadiene rubber (XNBR)/layered double hydroxide (MgAl-LDH) composites. The presence of these ionic liquids modified the relaxation behavior of the XNBR matrix. Increasing the length of the cation side-chain (from ethyl- to hexyl-) impactsthe glass transition temperature of the rubber matrix, the crosslink density, the mechanical properties and the ionic conductivity of the resulting XNBR/IL-LDH composites. Among this group of ionic liquids, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM TFSI)or alternatively 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIM TFSI)proved most suitable for enhancingthe ionic conductivity of rubber composites without substantial deterioration of their mechanical properties. [ABSTRACT FROM AUTHOR]

This work aimed to investigate the impact of hydrophobic imidazolium ionic liquids with alkyl chains of varying length attached to the cation imidazolium ring on the rheometric data, the mechanical, morphological, thermal and conductive properties of acrylonitrile-butadiene rubber (NBR) composites. The presence of ionic liquids not only increased the conductivity (AC) of the composites but also influenced their curing behaviour and mechanical properties. A maximum conductivity of 8.9 · 10−8 S · cm−1 was achieved at room temperature in the NBR sample containing 15 phr (parts per hundred rubber) of 1-hexyl-3-methylimidazolium bis(trifluoromethane- sulfone)imide (HMIM TFSI). Moreover, the presence of HMIM TFSI at 15 phr loading in the NBR composite contributed most significantly to the downward shift in the glass transition temperature ( T g) from -30 to −33 °C, indicating a plasticizing effect [ABSTRACT FROM AUTHOR]

In the present study, two types imidazolium salts containing the common cation 1-butyl-3-methylimidazolium-hydrophilic tetrachloroaluminate (BMIM AlCl4) and hydrophobic bis(trifluoromethylsulfonyl)imide (BMIM TFSI) are analyzed for effects on the ionic conductivity and the state of cure of carboxylated nitrile rubber/hydrotalcite composites (XNBR/HT). Imidazolium salt containing tetrachloroaluminate ions effectively participates in the crosslinking process of carboxylated nitrile rubber and contributes to an increase in the crosslink density of the composites. Hydrophobic 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide was found to be compatible with carboxylated nitrile rubber. In the presence of 15 parts per hundred rubber (phr) of BMIM TFSI, the ionic conductivity of the composites increases from 10−10 to 10−7 S·cm−1, and the glass transition temperature (Tg) of the XNBR shifts towards lower temperatures from -23 °C to -33 °C. [ABSTRACT FROM AUTHOR]

A brief Valsalva manoeuvre, lasting 2-3 s, performed by young healthy men during strength exercise reduces transmural pressure acting on intrathoracic arteries. In this study, we sought to verify this finding in older men. Twenty normotensive, prehypertensive and moderately hypertensive otherwise healthy men 46-69 years old performed knee extensions combined with inspiration or with brief Valsalva manoeuvre performed at 10, 20 and 40 mmHg mouth pressure. Same respiratory manoeuvres were also performed at rest. Non-invasively measured blood pressure, knee angle, respiratory airflow and mouth pressure were continuously registered. In comparison to inspiration, estimated transmural pressure acting on thoracic arteries changed slightly and insignificantly during brief Valsalva manoeuvre at 10 and 20 mmHg mouth pressure. At 40 mmHg mouth pressure, transmural pressure declined at rest (−8·8 ± 11·4 mmHg) and during knee extension (−12·1 ± 11·9 mmHg). This decline ensued, as peak systolic pressure increase caused by this manoeuvre, was distinctly <40 mmHg. Only a main effect of mouth pressure was revealed ( P<0·001) and neither exercise nor interaction between these factors, what suggests that transmural pressure decline, depended mainly on intrathoracic pressure developed during brief Valsalva manoeuvre. Resting blood pressure did not influence the effect of brief Valsalva manoeuvre on transmural pressure. [ABSTRACT FROM AUTHOR]

We investigated the influence of hydrophilic and hydrophobic imidazolium ionic liquids on the curing kinetic, mechanical, morphological and ionic conductivity properties of nitrile rubber composites. Two room temperature ionic liquids with a common cation-1-ethyl-3-methylimidazolium thiocyanate ( EMIM SCN; hydrophilic) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ( EMIM TFSI; hydrophobic)-were used. Magnesium-aluminium layered double hydroxide ( MgAl-LDH; also known as hydrotalcite) was added to carboxylated acrylonitrile-butadiene rubber ( XNBR) whereas fumed silica Aerosil 380 was used in acrylonitrile-butadiene rubber ( NBR) as reinforcing fillers. NBR compounds were vulcanized with a conventional sulfur-based crosslinking system whereas XNBR compounds were cured with MgAl-LDH. The optimum cure time reduction and tensile properties improvement were obtained when both ionic liquids were added at 5 parts per hundred rubber (phr). The results revealed that EMIM SCN and EMIM TFSI induced an increase in the AC conductivity of nitrile rubber composites from 10−10 to 10−8 and to 10−7 S cm−1, respectively (at 15 phr ionic liquid concentration). The presence of ionic liquids in NBR slightly affected the glass transition temperature ( Tg) whereas the presence of EMIM TFSI in XNBR contributed to a shift in Tg towards lower temperatures from −23 to −31 °C, at 15 phr loading, which can be attributed to the plasticizing behaviour of EMIM TFSI in the XNBR/ MgAl-LDH system. Dynamic mechanical analysis was also carried out and the related parameters, such as the mechanical loss factor and storage modulus, were determined. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Summary Strength training is a recommended measure against loss of strength and muscle mass because of age- or illness-induced inactivity. Strength exercises may impose heavy cardiovascular load by increasing heart rate and blood pressure. To increase strength efficiently, a heavy load has to be applied; this, however, leads to a spontaneous Valsalva manoeuvre, which additionally raises blood pressure. Avoidance of this manoeuvre is recommended. If the additional rise in arterial blood pressure caused by Valsalva manoeuvre is smaller than intrathoracic or intracranial pressures during this manoeuvre, Valsalva manoeuvre may actually protect arteries located in the thorax and in the brain by diminishing transmural pressure acting across these vessels. Effect of controlled breathing or brief Valsalva manoeuvre on arterial pressure at rest and during knee extension against 15-repetition maximum resistance was evaluated. In 12 healthy young men blood pressure was measured continuously and non-invasively, knee angle, speed of respiratory air or mouth pressure (MP) were continuously registered. Each combination of respiratory and exercise manoeuvres was repeated six times, for every of last three repetitions peak and trough systolic and diastolic pressure were determined. Strength exercises elevated peak pressures more than trough pressures, systolic more than diastolic. Valsalva manoeuvre increased only peak systolic and peak diastolic pressure. This increase was in average lesser than MP, thus rendering an argument in favour of protective role of brief Valsalva manoeuvre because of decline in transmural pressure acting on thoracic and possibly cerebral arteries. However, there was strong individual variability, and in few instances, arterial pressure increased because of brief Valsalva manoeuvre more than MP; thus in some subjects, the manoeuvre might enhance transmural pressure acting on thorax arteries. [ABSTRACT FROM AUTHOR]

Translationally Controlled Tumour Protein (TCTP) associates with microtubules (MT), however, the details of this association are unknown. Here we analyze the relationship of TCTP with MTs and centrosomes in Xenopus laevis and mammalian cells using immunofluorescence, tagged TCTP expression and immunoelectron microscopy. We show that TCTP associates both with MTs and centrosomes at spindle poles when detected by species-specific antibodies and by Myc-XlTCTP expression in Xenopus and mammalian cells. However, when the antibodies against XlTCTP were used in mammalian cells, TCTP was detected exclusively in the centrosomes. These results suggest that a distinct pool of TCTP may be specific for, and associate with, the centrosomes. Double labelling for TCTP and γ-tubulin with immuno-gold electron microscopy in Xenopus laevis oogonia shows localization of TCTP at the periphery of the γ-tubulin-containing pericentriolar material (PCM) enveloping the centriole. TCTP localizes in the close vicinity of, but not directly on the MTs in Xenopus ovary suggesting that this association requires unidentified linker proteins. Thus, we show for the first time: (1) the association of TCTP with centrosomes, (2) peripheral localization of TCTP in relation to the centriole and the γ-tubulin-containing PCM within the centrosome, and (3) the indirect association of TCTP with MTs [ABSTRACT FROM AUTHOR]

Abstract: Small heat shock proteins (sHsps) associate with aggregated proteins, changing their physical properties in such a way that chaperone mediated disaggregation becomes much more efficient. In Escherichia coli two small Hsps, IbpA and IbpB, exist. They are 48% identical at the amino acid level, yet their roles in stabilisation of protein aggregates are quite distinct. Here we analysed the biochemical properties of IbpA. We found that IbpA assembles into protofilaments which in turn form mature fibrils. Such fibrils are atypical for sHsps. Interaction of IbpA with either its cochaperone IbpB or an aggregated substrate blocks IbpA fibril formation. Structured summary: MINT-7876715: ibpA (uniprotkb:P0C054) and ibpA (uniprotkb:P0C054) bind (MI:0407) by molecular sieving (MI:0071) MINT-7888427: ibpB (uniprotkb:P0C058) and ibpB (uniprotkb:P0C058) bind (MI:0407) by molecular sieving (MI:0071) MINT-7888448: ibpA (uniprotkb:P0C054) and ibpA (uniprotkb:P0C054) bind (MI:0407) by electron microscopy (MI:0040) MINT-7888434: ibpB (uniprotkb:P0C058) and ibpB (uniprotkb:P0C058) bind (MI:0407) by electron microscopy (MI:0040) MINT-7888459: ibpA (uniprotkb:P0C054) and ibpA (uniprotkb:P0C054) bind (MI:0407) by fluorescence microscopy (MI:0416) [Copyright &y& Elsevier]

It has been proposed that glial cells may supply carbon fuel to neurons and also that there are fluxes of ammonium from neurons to glia. We have investigated both these proposals in Apis retinal slices, in which virtually all the mitochondria are in the photoreceptor neurons. Normally the superfusate contained no substrate of energy metabolism; addition of glucose or alanine did not increase oxygen consumption , confirming that the neurons received adequate substrate from glycogen in the glia. 1,4-Dideoxy-1,4-imino-d-arabinitol (DAB, 100 μm), an inhibitor of glycogen phosphorylase, progressively decreased . This decrease was reversed by alanine but not glucose. Ammonium-sensitive microelectrodes did not detect significant extracellular [NH4+] ([NH4+]e) in slices superfused with normal superfusate. Removal of Cl−, necessary for cotransport of NH4+ into the glia, increased [NH4+]e so that at the end of 2 min photostimulation mean [NH4+]e was 0.442 mm (s.e.m.= 0.082 mm, n= 16). In 0 Cl−, [NH4+]e was reduced by 2-(methylamino)isobutyrate (MeAIB) an inhibitor of alanine transport. MeAIB also blocked oxidation of alanine in the presence of DAB, but did not decrease in normal superfusate. Lactate (l andd) and pyruvate (but not glucose) increased in DAB and decreased [NH4+]e in 0 Cl−. These results strengthen the evidence that in superfused retinal slices, glucose is metabolized exclusively in the glia, which supply alanine to the neurons, and that ammonium returns to the glia. They also show that another fuel (perhaps lactate) can be supplied by the glia to the neurons. [ABSTRACT FROM AUTHOR]

Immature dendritic cells (DC) reside in tissues where they initiate immune responses by taking up foreign antigens. Since DC have a limited tissue half-life, the DC pool in tissues has to be replenished constantly. This implies that precursor/immature DC must be able to cross non-activated endothelium using as yet unknown mechanisms. Here we show that immature, but not mature bone marrow-derived murine DC migrate across resting endothelial monolayers in vitro. We find that endothelial intercellular adhesion molecule-2 (ICAM-2) is a major player in transendothelial migration (TEM) of immature DC, accounting for at least 41% of TEM. Surprisingly, the ICAM-2-mediated TEM was independent of β-integrins, the known ICAM-2 ligands, since neither blocking of β-integrins with antibodies nor the use of CD18-deficient DC affected the ICAM-2-specific TEM. In humans, the C-type lectin DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN) was shown to interact with ICAM-2, suggesting a similar role in mice. However, we find that none of the murine DC-SIGN homologues mDC-SIGN, murine DC-SIGN-related molecule-1 (mSIGN-R1) and mSIGN-R3 is expressed on the surface of bone marrow-derived mouse DC. Taken together, this study shows that ICAM-2 strongly supports transmigration of immature DC across resting endothelium by interacting with ligands that are distinct from β-integrins and DC-SIGN homologues. [ABSTRACT FROM AUTHOR]

Examines the fusogenic properties of bacteriophage gene product Rz1. Categories of chemicals and lipids used in the experiments; Method used for the preparation of liposomes; Results observed by monitoring liposome aggregation; Observations made about the fusion of liposomal membranes on the basis of changes in the resonance energy transfer between lipids.

To study whether the adhesion of colon cancer cells to E-selectin can be directly affected by changes in the expression level of sialosyl Lea antigen we created a specific loss-of-function phenotype. A stable subclone (CX-1.1) with high expression of sialosyl Lea structure, obtained from a heterogenous population of colon carcinoma CX-1 cells, was transfected with an expression vector containing a fragment of cDNA for α1,3/4-fucosyltransferase in antisense orientation. After transfection, the cell line was isolated which did not express sialosyl Lea antigen and lacked the α1,3/4-fucosyltransferase activity, despite an unchanged level of mRNA specific for this enzyme. It was found that the specific lack of expression of sialosyl Lea carbohydrate structure on the surface of colon cancer cells completely abolished their adhesion to E-selectin. To evaluate which cellular glycoconjugates carry sialosyl Lea antigen, glycoproteins as well as glycolipids of CX-1.1 cells were analysed for the expression of this structure. Anti-sialosyl Lea antibodies detected multiple glycoprotein bands with apparent molecular masses of 65-280 kDa on western blots, and an intense band representing sialosyl Lea-ganglioside on a thin-layer chromatogram. Using O-sialoglycoprotease from Pasteurella haemolytica and an alkaline β-elimination procedure, it was shown that protein-linked sialosyl Lea structures are carried mostly by mucin-type glycoproteins. However, treatment of CX-1.1 cells with O-sialoglycoprotease did not decrease either their binding to E-selectin-expressing Chinese hamster ovary cells, or binding of anti-sialosyl Lea antibodies to the cell surface. These results suggested that cleavage of sialomucins uncovered cryptic sialosyl Lea-ganglioside, which was inaccessible for the antibody and E-selectin in untreated cells. This hypothesis was confirmed to... [ABSTRACT FROM AUTHOR]

In 25 bulls, blood and semen selenium concentration, as well as glutathione peroxidase (GSH-Px) activity and lipid peroxide level and motility of spermatozoa were studied. The mean concentrations of Se in blood, seminal plasma and spermatozoa were 44.2 ± 7.6 ng/ml, 257 ± 98 ng/ml and 583 ± 143 ng/109 cells, respectively. The activity of total GSH-Px and Se-dependent GSH-Px in spermatozoa were 1.9 ± 0.7 and 0.3 ± 0.1 U/109 cells and in seminal plasma 19.2 ± 4.4 and 5.3 ± 1.6 U/ml, respectively. A significant correlation between selenium concentration and Se GSH-Px activity in seminal plasma (r = 0.79, p ≤ 0.01) was found. The latter showed an inverse linear relation with the activity of the total enzyme activity in spermatozoa (r = 0.39, p ≤ 0.05). No significant correlation was found between the selenium concentration in blood and GSH-Px activity in semen or between blood Se level and concentration of this element in semen. Observation of spermatozoa motility after freezing - thawing showed that the portions of excellent semen quality (motility ≥ 30% after thawing), before freezing had lower lipid peroxide content (p ≤ 0.001) than semen samples qualified as 'unusable'. After 3 h incubation at 37°C samples containing significantly lower Se concentrations and total GSH-Px activity in spermatozoa and higher levels of lipid peroxide in fresh semen tended to have lower motilities recorded. Zusammenfassung Selengehalt, Glutathion-Peroxidase-Aktivität und Gehalt an Lipidperoxiden in frischem Bullen-Sperma und deren Beziehung zur Spermienmotilität nach dem Einfrieren und Auftauen Bei 25 Bullen wurde sowohl die Selenkonzentration und Glutathionperoxidaseaktivität des Blutes und des Samens als auch der Gehalt an Lipidperoxiden und die Motilität der Spermien untersucht. Die mittleren Selenkonzentrationen im Blut, Seminalplasma und in den Spermien betrugen 44,2 ± 7,6 ng/ml, 237 ± 98 ng/ml bzw. 583 ± 143 ng/109 Zellen. Die Aktivität der gesamten GSH-Px und der Se-abhängigen GSH-Px betrug in den Spermien 1,9 ± 0,7 und 0,3 ± 0,1 Einheiten pro 109 Zellen, im Seminalplasma dagegen 19,2 ± 4,4 und 5,3 ± 1,6 Einheiten pro ml. Zwischen der Selenkonzentration und der GSH-Px-Aktivität des Seminalplasmas wurde eine signifikante Korrelation (r = 0,79, p ≤ 0,01) gefunden. Für die letztere ergab sich eine reziproke Beziehung zur Aktivität der gesamten GSH-Px der Spermien (r = 0,39, p ≤ 0,05). Keine signifikante Beziehung wurde zwischen der Se-Konzentration des Blutes und der GSH-Px-Aktivität im Sperma bzw. zwischen der Se-Konzentration des Blutes und der Se-Konzentration des Spermas gefunden. Die Erfassung der Spermienmotilität nach dem Einfrieren und Wiederauftauen zeigte, daß die Samenportionen mit hervorragender Qualität (Motilität ≥ 30% nach dem Auftauen) vor dem Einfrieren einen geringeren Gehalt an Lipid-Peroxiden (p ≤ 0,001) aufwiesen als die als 'unbrauchbar' qualifizierten Samenportionen. Nach 3stündiger Inkubation bei 37°C zeigten die Samenportionen, die im frischen Zustand signifikant erniedrigte Se-Konzentration und Gesamt-GSH-Px-Aktivität in den Spermien und erhöhte Lipid-Peroxid-Gehalte im Sperma aufwiesen, eine etwas herabgesetzte Motilität. [ABSTRACT FROM AUTHOR]

Thermally aggregated, endogenous proteins of Escherichia coli form a distinct fraction, denoted 5, which is separable by sucrose-density-gradient centrifugation. It was shown earlier that DnaK, DnaJ, IbpA and IbpB heat-shock proteins are associated with the 5 fraction. Comparison of the rise and decay of the S fraction in mutants defective for heat-shock proteases Lon (La), Clp, HtrA (DegP, Do) and in wild-type strains made studies of proteolysis and the function of the heat-shock response possible in vivo. Different timing and the extent of action of particular proteases was revealed by the initial size and decay kinetics of the S fraction. The proteases Lon, Clp, and HtrA all participated in removal of the aggregated proteins. Mutation in the gene encoding ClpB caused the most prominent effect (47% stabilization of the S fraction). The correlation between the disappearance of the S fraction and proteolytic activity was supported by the result of the in vitro reaction. Approximately one third of the isolated S fraction was converted to trichloro-acetic acid-soluble products by the purified HtrA protease. Mg2+ ions stimulated the reaction, in contrast to the reaction of the HtrA protease with casein. The digestion of the aggregated proteins, unlike the digestion of casein, by HtrA protease in vitro was inhibited by added DnaJ, which might reflect protection of the aggregated proteins in vivo by DnaJ from excessive degradation. One might expect that such an activity of DnaJ would promote denatured protein renaturation versus proteolysis. Moreover, among the aggregated proteins that are discernible by electrophoresis, none could be identified as being more susceptible than any other to HtrA degradation. The separation pattern of these proteins before and after the in vitro digestion did not show a difference corresponding to the loss of about 30% of constituting proteins. This was interpreted as recognition by the HtrA protease of a state of protein denaturation rather than specific amino acid sequences in particular proteins. We conclude that the fraction consisting of proteins heat-aggregated in vivo (i.e. the S fraction) contains endogenous substrates for the heat-shock proteases tested. Their use for in vitro reaction reveals information that is in some respects different from that obtained with exogenous substrates such as casein. [ABSTRACT FROM AUTHOR]

Heat shock induces protein aggregation in Escherichia coli and E. coli (λ cl857). The aggregates (S fraction) appear 15 min post-induction and are separable from membranes by sucrose density-gradient centrifugation. The S fraction quickly disappears in wild type strains but persists in rpoH mutant with concomitant quick inner membrane destruction. We propose that: (1) the disappearance of the S fraction reflects a rpoH-dependent processing, (2) the membrane destruction explains the lethality of the rpoH mutation at elevated temperatures; and (3) the protection of the inner membrane integrity is an important physiological function of the heat-shock response. We assume that the S fraction of aggregated proteins represents the signal inducing the heat-shock response. The prophage thermo-induction results in an increase (35 min post-induction) in the A fraction resembling that of the adhesion zones of the membranes. This fraction is greater than the corresponding fraction from uninduced cells. The increase is mediated by the λ late genes, since it is absent in the induced E.coli (λ cl857 Qam21). Since heat shock is widely used for induction of the λ promoters in expression vectors it is possible that the formation of the protein aggregates (though transient in WT strains) and/or the fragility of membranes in rpoH mutants may be the cause of poor expression of cloned genes or may lead to mistaken localization of their expression products. [ABSTRACT FROM AUTHOR]

With 2 tables Nicotiana tabacum cv. 'Polalta' is reported as having a hypersensitive type of Tomato spotted wilt virus (TSWV) resistance. In 'Polalta' hybrids with susceptible cultivars, morphological deformations (thickened and ribbon‐shaped leaves, irregular venation, tumours) appear. Acceptable DH lines derived from hybrids of 'Polalta' with 'Wiślica' were obtained by a method of in vitro culture. Those DH lines were evaluated for TSWV resistance. Tests for resistance were conducted under greenhouse conditions using one TSWV isolate from a local source. The presence of the virus was verified using DAS‐ELISA. The DH lines PW‐833, PW‐834, and PW‐900 showed a near correct morphology and stably inherited dominant monogenic resistance to TSWV. [ABSTRACT FROM AUTHOR]