Effect of vanadium on renal Na<Superscript>+</Superscript>,K<Superscript>+</Superscript>-ATPase activity in diabetic rats: a possible role of leptin

Several researches attempt to protect diabetic patients from the development of nephropathy. Involvement of leptin and renal Na⁺,K⁺-ATPase enzyme in diabetic nephropathy (DN) development is a recent field for researches. Vanadium, as a trace element with insulin mimetic effect, may act synergistically with insulin to protect against the development of DN. Sixty male Sprague Dawley rats were divided into six groups: control group (C), vanadium control group (CV), streptozotocin-induced diabetic group (D), insulin-treated diabetic group (DI), vanadium-treated diabetic group (DV), and combined insulin and vanadium-treated diabetic group. Six weeks later, systolic blood pressure (SBP) was measured and retro-orbital blood samples were collected to estimate glycosylated hemoglobin (HbA_1c), serum sodium (Na⁺) and creatinine, blood urea nitrogen (BUN) and plasma leptin levels. Preparation of microsomal fraction of renal tissue homogenate for estimation of Na⁺,K⁺-ATPase activity was done. The D group showed a significant increase in SBP, HbA_1c, serum Na⁺, creatinine, and BUN levels and Na⁺,K⁺-ATPase activity in microsomal fraction of renal tissue homogenate while plasma leptin level decreased significantly compared with C and CV groups. Both DI and DV groups showed a significant improvement in all the above measured parameters compared with D group while there were no significant changes between the DI and DV groups. Concomitant treatment with insulin and vanadium resulted in a significant improvement in all the measured parameters compared to each alone. Vanadium in combination with insulin ameliorates DN markers and reduces renal Na⁺,K⁺-ATPase overactivity in diabetic rats. An effect that may be partially mediated through correction of hypoleptinemia observed in these animals.     

Phylogenetic and Demographic Insights into Kuhl’s Pipistrelle,Pipistrellus kuhlii,in the Middle East

Kuhl’s pipistrelle is found from Europe and North Africa all of the way to Asia, yet studies have thus far concentrated on the western limit of its distribution. Here we form a multi-marker picture of the diversity of Kuhl’s pipistrelle at a mid point in the Arabian peninsula in an attempt to redress the western sampling bias and to represent a region from which no genetic data has thus far been presented for this species. The three Arabian Cytochrome b haplotypes showed a clear divergence of 19 substitutions from those found in either Europe or North Africa. Molecular dating suggests the Arabian population split from the remaining Kuhl’s somewhere between 0.7 and 1.7 million years before present around the time of a series of aridification events across northern Africa. Well supported lineages within Arabia are typical of that which may be seen after an expansion from multiple Pleistocene refugia, but may also reflect the loss of intermediate haplotypes during historical population fluctuations. A long-term population contraction coincides with climatic changes towards those conditions more typical of contemporary Arabia.     

Do ABO Blood Group Antigens Hamper the Therapeutic Efficacy of Mesenchymal Stromal Cells?

Investigation into predictors for treatment outcome is essential to improve the clinical efficacy of therapeutic multipotent mesenchymal stromal cells (MSCs). We therefore studied the possible harmful impact of immunogenic ABO blood groups antigens – genetically governed antigenic determinants – at all given steps of MSC-therapy, from cell isolation and preparation for clinical use, to final recipient outcome.We found that clinical MSCs do not inherently express or upregulate ABO blood group antigens after inflammatory challenge or in vitro differentiation. Although antigen adsorption from standard culture supplements was minimal, MSCs adsorbed small quantities of ABO antigen from fresh human AB plasma (ABP), dependent on antigen concentration and adsorption time. Compared to cells washed in non-immunogenic human serum albumin (HSA), MSCs washed with ABP elicited stronger blood responses after exposure to blood from healthy O donors in vitro, containing high titers of ABO antibodies. Clinical evaluation of hematopoietic stem cell transplant (HSCT) recipients found only very low titers of anti-A/B agglutination in these strongly immunocompromised patients at the time of MSC treatment. Patient analysis revealed a trend for lower clinical response in blood group O recipients treated with ABP-exposed MSC products, but not with HSA-exposed products.We conclude, that clinical grade MSCs are ABO-neutral, but the ABP used for washing and infusion of MSCs can contaminate the cells with immunogenic ABO substance and should therefore be substituted by non-immunogenic HSA, particularly when cells are given to immunocompentent individuals.     

Arteries define the position of the thyroid gland during its developmental relocalisation

During vertebrate development, the thyroid gland undergoes a unique relocalisation from its site of induction to a distant species-specific position in the cervical mesenchyme. We have analysed thyroid morphogenesis in wild-type and mutant zebrafish and mice, and find that localisation of growing thyroid tissue along the anteroposterior axis in zebrafish is linked to the development of the ventral aorta. In grafting experiments, ectopic vascular cells influence the localisation of thyroid tissue cell non-autonomously, showing that vessels provide guidance cues in zebrafish thyroid morphogenesis. In mouse thyroid development, the midline primordium bifurcates and two lobes relocalise cranially along the bilateral pair of carotid arteries. In hedgehog-deficient mice, thyroid tissue always develops along the ectopically and asymmetrically positioned carotid arteries, suggesting that, in mice (as in zebrafish), co-developing major arteries define the position of the thyroid. The similarity between zebrafish and mouse mutant phenotypes further indicates that thyroid relocalisation involves two morphogenetic phases, and that variation in the second phase accounts for species-specific differences in thyroid morphology. Moreover, the involvement of vessels in thyroid relocalisation sheds new light on the interpretation of congenital thyroid defects in humans.     

Influence of selected sugars and temperature on fatty acids composition in Candida lipolytica

Summary An investigation was made of the effects of temperature and of mono- and disaccharides on lipids, biomass, odd-chain and unsaturated fatty acids production of Candida lipolytica. With different sugars as carbon source at 30°C, the order for biomass production was: fructose > glucose > sucrose > lactose > galactose, while lipids production/g biomass decreased as follows: lactose, sucrose, galactose, fructose and glucose. On the other hand, the odd-chain fatty acids contents decreased in the following order: fructose, lactose, glucose, sucrose and galactose. Lowering the temperature of cultivation to 15°C, biomass, lipids and unsaturated fatty acids decreased. However, a notable decrease in the content of odd-chain fatty acids was detected.     

Pyrogenic toxins of Staphylococcus aureus in sudden unexpected nocturnal deaths in adults and older children: factors influencing the control of inflammatory responses to toxic shock syndrome toxins

Sudden unexpected nocturnal deaths (SUND) occur in young immigrant workers, mainly from south-east Asia, who are employed in countries such as Singapore and Saudi Arabia. Pyrogenic toxins of Staphylococcus aureus have been identified in two cases of sudden unexpected death in adults in the UK and it has been suggested that these or other toxins with superantigen properties might induce strong inflammatory responses leading to sudden unexpected nocturnal deaths. The objectives of the present study were (1) to assess the levels of antibodies to pyrogenic staphylococcal toxins in the general population, (2) to assess the levels of IgG to the toxins needed to reduce the production of inflammatory mediators by 50% in a model system, (3) to assess in a model system the effects on inflammatory responses to toxic shock syndrome toxin-1 (TSST) of cortisol levels present at night, during the day and under conditions of physiological stress. Enzyme linked immunosorbent assays were used to assess levels of IgG to TSST, staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin C (SEC). Human buffy coats were used to examine the effect of IgG to the toxins for neutralising activity and the effect of cortisol on induction of inflammatory mediators. Tumour necrosis factor alpha (TNF-alpha) was detected by a bioassay with L929 cells, interleukin-6 (IL-6) and interleukin-10 (IL-10) were measured by an enzyme linked immunosorbent assay. IL-6 and TNF-alpha levels elicited by the toxins were not reduced by night time levels of cortisol (5-10 microg dl(-1)) levels. Day time levels of cortisol (10-20 microg dl(-1)) significantly inhibited IL-6 production but not TNF-alpha in responses. Stress levels of cortisol (40 80 microg dl(-1)) significantly reduced all three cytokines earlier than the normal day time levels. The majority of the population tested had sufficient antibodies to reduce TNF-alpha and IL-6 responses elicited by TSST and SEC in the model system. In the age range in which most sudden unexpected nocturnal death cases occur (20-39 years), males had significantly lower levels of IgG to TSST compared with females. If these toxins play a role in precipitating the series of events leading to sudden unexpected nocturnal death, the higher levels of IgG to the toxins observed in females might explain partly the much higher prevalence of these deaths among men in this age range. If inflammatory responses play a role in sudden unexpected nocturnal death, the inability of the night time levels of cortisol to control IL-6 and TNF-alpha in the model system might reflect these interactions in vivo. The methods developed for detection of the toxins in tissue samples and the quantitative IgG assays for anti-toxins can be applied to investigation of SUND victims to test the hypothesis that some of these deaths are precipitated by pyrogenic staphylococcal toxins.     

A lignan glucoside from Euphrasia rostkoviana

A new lignan glucoside has been isolated from Euphrasia rostkoviana. Its structure was elucidated by spectroscopic means and by correlation with dehydrodiconiferyl alcohol to be dehydrodiconiferyl alcohol- 4-β-d-glucoside.     

Treatment of three-point linkage data inNeurospora crassa

In three-point linkage experiments inNeurospora crassa, when recombination frequencies are suspected of being affected by differetial viability, the experimental remedy is to perform the four possible complementary crosses, using in parallel the four pairs of complementary genotypes. If the viability ratio is the same in these crosses, its effect upon crossover frequencies can be eliminated and a valid estimate of recombination fractions can be made.     

Development and validation of an ion-pair liquid chromatographic method for the quantitation of sodium cromoglycate in urine following inhalation

An ion-pair liquid high-performance chromatography method with solid-phase extraction for measuring urinary concentrations of sodium cromoglycate following inhalation has been developed and validated. Sodium cromoglycate was extracted from urine on a 100-mg phenyl cartridge (Isolute, Jones Chromatography) and then quantified on a 25-cm C₈ Spherisorb 5 μm stationary phase with a mobile phase of methanol-0.045 M phosphate buffer-0.05 M dodecyl triethyl ammonium phosphate (550:447.6:2.4, v/v) pH 2.3, at 0.85 ml min⁻¹ using nedocromil sodium as an internal standard and UV detection at 238 nm. The inter- and intra-day reproducibilities were 8.33 and 13.63%, respectively, at 0.25 mg l⁻¹. The limit of determination for sodium cromoglycate was 0.25 mg l⁻¹ (with a signal-to-noise ration of greater than 10:1). Following oral and inhaled administration of 20 mg of sodium cromoglycate to eight healthy volunteers, the mean and S.D. of sodium cromoglycate excreted in the urine at 0.5, 1 and 24 h post-dose were 0.02, 0.05 and 0.33%, and 0.16, 0.30 and 1.55% of the dose, respectively. The urinary recovery of sodium cromoglycate at 0.5 and 1 h following inhalation can therefore be used to compare the amount of drug reaching the respiratory tract using different sodium cromoglycate inhaled products or inhalation methods.