Reduction of radiation-induced nitrative stress in leucocytes and kidney cells of rats upon administration of polyphenolic complex concentrates from red wine

The research has shown that exposure to ionizing radiation at the dose of 30 cGy leads to the activation of NO-synthase way of nitrogen oxide synthesis, as well as to the accumulation of its stable metabolites and 3'-nitrotyrosine modified proteins in rat peripheral blood leucocytes and the renal cortical layer. NO-synthase activity was preserved at the control value through the consumption of red wine naturalpolyphenolic complex concentrates by the irradiated animals. The content of proteins modified by tyrosine nitration decreased in the early period of post-radiation exposure due to the influence of the investigated concentrate. Thus the ability of red wine natural polyphenolic complex concentrates to prevent adverse changes in L-arginine/NO system and, therefore, inhibit the development of nitrative stress induced by low doses of ionizing radiation has been proved experimentally.     

Changes in functional state of the low-molecular G-proteins of platelets in type 1 diabetes mellitus

Platelets from healthy donors and insuline dependent patients with type 1 diabetes mellitus were examined for proteins specifically interacting in vitro with GST-fused constitutively active (Val12) forms of small GTPases of Rac, Rho and Cdc42. Differential changes in pattern of proteins which bind to these G-proteins in diabetic platelets have been revealed. Obtained results suggest that signalling pathways mediated by Rho GTPases are altered under type I diabetes mellitus. Such changes of actin cytoskeleton regulation may contribute to the higher level of platelet aggregation, which prove to be the etiological background of the late diabetes complications.     

Development of a transformation system for the flavinogenic yeast Candida famata

Riboflavin-overproducing mutants of the flavinogenic yeast Candida famata are used for industrial riboflavin production. This paper describes the development of an efficient transformation system for this species. Leucine-deficient mutants have been isolated from C. famata VKM Y-9 wild-type strain. Among them leu2 mutants were identified by transformation to leucine prototrophy with plasmids YEp13 and PRpL2 carrying the Saccharomyces cerevisiae LEU2 gene. DNA fragments (called CfARSs) conferring increased transformation frequencies and extrachromosomal replication were isolated from a C. famata gene library constructed on the integrative vector containing the S. cerevisiae LEU2 gene as a selective marker. The smallest cloned fragment (CfARS16) has been sequenced. This one had high adenine plus thymine (A+T) base pair content and a sequence homologous to the S. cerevisiae ARS Consensus Sequence. Methods for spheroplast transformation and electrotransformation of the yeast C. famata were optimized. They conferred high transformation frequencies (up to 10(5) transformants per microg DNA) with a C. famata leu2 mutant using replicative plasmids containing the S. cerevisiae LEU2 gene as a selective marker. Riboflavin-deficient mutants were isolated from the C. famata leu2 strain and their biochemical identification was carried out. Using the developed transformation system, several C. famata genomic fragments complementing mutations of structural genes for riboflavin biosynthesis (coding for GTP cyclohydrolase, reductase, dihydroxybutanone phosphate synthase and riboflavin synthase, respectively) have been cloned.     

Protective effects of polyphenolics in red wine on diabetes associated oxidative/nitrative stress in streptozotocin‐diabetic rats

Increased accumulation of NT (3‐nitrotyrosine) and PARylated [poly(ADP‐ribosyl)ated] proteins in the tissues of diabetics are associated with diabetes complications (diabetes neuropathy, nephropathy and retinopathy). Red wine (its polyphenols are considered to be the main active components) can act as ROS (reactive oxygen species) scavengers, iron chelators and enzyme modulators. This study is novel in investigating the effect of red wine in preventing the accumulation of NT and PARylated proteins in the sciatic nerve, DRG (dorsal root ganglia), spinal cord, kidney and retina of diabetic animals. We have shown that during the experiment the body weight of control and diabetic groups of rats with consumption of red wine was significantly increased, by 52% and 19% accordingly. The significant increase in the content of NT in the sciatic nerve, DRG, spinal cord, kidney and retina, and PARylated proteins in the sciatic nerve, renal glomeruli and retinae of diabetic rats was partly or completely prevented by treatment with red wine. Red wine and its polyphenol preparations might be a promising option in the prevention and treatment of diabetic complications.     

Effect of aminoguanidine on oxidative modification of proteins in experimental diabetes mellitus in rats

It was shown that administration of aminoguanidine is accompanied by a decrease of the content of nitric oxide stable metabolites, as well as protein carbonyl groups in leukocytes and blood plasma in diabetic and control animals. Aminoguanidine is proposed to be used for pharmacological correction of NO biosynthesis. Aminoguanidine, being the selective iNOS inhibitor, antioxidant and the factor eliminating post-translational protein nitrozylation and oxidative modification, weaken the toxic effects of NO and positively modulates the pathological state caused by NO hyperproduction.     

Mononuclear and polymorphonuclear leukocytes show increased fructose-1,6-bisphosphatase activity in patients with type 1 diabetes mellitus

The activity and localization of fructose-1,6-bisphosphatase (FBPase; EC 3.1.3.11) in blood leukocytes of patients with type 1 diabetes mellitus and healthy adults were investigated immunocytochemically. The amount of polymorphonuclear (PMN) and mononuclear (MN) cells with positive FBPase immunocytochemical reaction was 57% and 68%, respectively, in pathological, and 38% and 42%, respectively, in healthy donors. Results of light microscopic investigations were confirmed by measurements of FBPase activity following lysis of PMN and MN cells. The enzyme activity of PMN and MN leukocytes was higher in diabetes mellitus than in healthy adults, by 30% and 127%, respectively. Using immunocytochemistry together with electron microscopy, FBPase was detected not only in the cytoplasm but also in the nucleus of leukocytes of both patients with insulin-dependent diabetes mellitus and healthy donors.     

Cranial anatomy,taxonomic implications and palaeopathology of an Upper Jurassic Pliosaur (Reptilia: Sauropterygia) from Westbury,Wiltshire, UK

Abstract: Complete skulls of giant marine reptiles of the Late Jurassic are rare, and so the discovery of the 1.8‐m‐long skull of a pliosaur from the Kimmeridge Clay Formation (Kimmeridgian) of Westbury, Wiltshire, UK, is an important find. The specimen shows most of the cranial and mandibular anatomy, as well as a series of pathological conditions. It was previously referred to Pliosaurus brachyspondylus, but it can be referred reliably only to the genus Pliosaurus, because species within the genus are currently in need of review. The new specimen, together with another from the same locality, also referred to P. brachyspondylus, will be crucial in that systematic revision, and it is likely that the genus Pliosaurus will be found to include several genera. The two Westbury Pliosaurus specimens share many features, including the form of the teeth, but marked differences in the snout and parietal crest suggest sexual dimorphism; the present specimen is probably female. The large size of the animal, the extent of sutural fusion and the pathologies suggest this is an ageing individual. An erosive arthrotic condition of the articular glenoids led to prolonged jaw misalignment, generating a suite of associated bone and dental pathologies. Further damage to the jaw joint may have been the cause of death.     

On the existence of a gradient of sensitivity to the lack of sodium in the spinal roots of the bullfrog

The Et class of fibers includes fibers of Gasser's d.r. C group. The fibers of the dorsal root are more sensitive to the effect of lack of sodium than are the fibers of the ventral root. In the two roots there is a gradient of sensitivity to the lack of sodium, which is such that in all the root fibers the sensitivity decreases with increasing distance from the spinal cord. The gradient continues in the trunk up to about 10 to 12 mm. peripheral to the trunk-roots margin. No comparable gradient of sensitivity to the lack of sodium has been observed in the rest of the nerve trunk. The gradient of sensitivity to the lack of sodium has no relationship to the anatomical distribution of the epineurium. As a working hypothesis it is suggested that the gradient of sensitivity to the lack of sodium is one aspect of a transitional gradient that serves to establish a gradual change between the properties that the axons have inside the spinal cord and the properties that they have inside the nerve trunks. Details are given of the temporal course of the loss of excitability by root fibers deprived of sodium. It is suggested that sodium is present in the nerve fibers, in 2 forms, loosely and tightly bound sodium and that loss of loosely bound sodium is sufficient to render the nerve fibers unable to conduct impulses. If the rate of loss of loosely bound sodium is decreased, conversion of tightly bound into loosely bound sodium may temporarily restore the excitability of the nerve fibers.