Nerve-perivascular fat communication as a potential influence on the performance of blood vessels used as coronary artery bypass grafts

Perivascular fat, the cushion of adipose tissue surrounding blood vessels, possesses dilator, anti-contractile and constrictor actions. The majority of these effects have been demonstrated in vitro and may depend on the vessel and/or the experimental method or species used. In general, the relaxant effect of perivascular adipose tissue is local and may be either endothelium-dependent or endothelium-independent. However, nerve stimulation studies show that, in general, perivascular adipose tissue (PVAT) has an anti-contractile vascular effect likely to involve an action of the autonomic vascular nerves. Apart from a direct effect of perivascular fat-derived factors on bypass conduits, an interaction with a number of neurotransmitters and other agents may play an important role in graft performance. Although the vascular effects of PVAT are now well-established there is a lack of information regarding the role and/or involvement of peripheral nerves including autonomic nerves. For example, are perivascular adipocytes innervated and does PVAT affect neuronal control of vessels used as grafts? To date there is a paucity of electrophysiological studies into nerve-perivascular fat control. This review provides an overview of the vascular actions of PVAT, focussing on its potential relevance on blood vessels used as bypass grafts. In particular, the anatomical relationship between the perivascular nerves and fat are considered and the role of the perivascular-nerve/fat axis in the performance of bypass grafts is also discussed.     

DISTAN -- A program which detects significant distances between short oligonucleotides

We present an algorithm to detect distances between oligonucleotidesin large collections of nucleic acids sequences. The ratiosof actual frequencies of occurrence of short oligonucleotidesat a given distance to the corresponding expected frequencieswere analyzed in four categories of DNA sequences (eukaryoticexons, bacterial genes, introns and non-Alu repeated DNAs).Three base periodic occurrences (independent of the readingframe) of all combinations of mononucleotides and repeats ofall dinucleotides was characteristic for protein coding regions.This was also the case with the majority of trinucleotides (includingtranslational stop signals) in these regions. Mirror-symmetrictrinucleotides (except GCG and CGC) displayed a strong tendencyto be two base periodically repeated in introns. Some two andthree base periodic motifs were also observed in repeated DNAs.The possible biological implications of outstanding three baseperiodicities in bacterial genes and eukaryotic exons are discussed. Received on March 2, 1987; accepted on May 5, 1987     

The influence of hypomagnesemia on erythrocyte antioxidant enzyme defence system in mice

The effect of magnesium deficiency on antioxidant defence system was studied in RBC of mice suffering from hypomagnesemia. The animals were kept for 8, 15 and 22 days on magnesium-deficient diet with consequent reduction of magnesium level in plasma by 38% at the first 8 days and by 64% after 22 days of experiment. The activities of the most important antioxidant enzymes, catalase, glutathione peroxidase, superoxide dismutase, glutathione reductase, glutahione S-transferase were assayed in hemolysates. The level of reduced glutathione in erythrocytes was measured as well. Apart from catalase, the activities of antioxidant enzymes were decreasing. The activity of superoxide dismutase decreased gradually during the experiment and on the 15th and 22nd day of experiment was significantly (P<0,05) lowered by 30 and 32% respectively. The catalase activity was increased on each point of the experiment with the peak value up to 149% on 15th day, and by 32% on 22nd day. Glutathione peroxidase activity was insignificantly reduced. The reduction of Glutatione reductase and Glutathione S-transferase activities by 24 and 21%, respectively, were observed after 8 days of the experiment with a further downward tendency. The reduced glutathione was significantly depleted after 8 days by 33% and was kept on that level in the course of the study. These findings support previous reports on the hypomagnesemia – induced alteration in endogenous enzyme antioxidant defences and glutathione redox cycle of mice.     

Combined effect of X‐ray radiation and static magnetic fields on reactive oxygen species in rat lymphocytes in vitro

The aim of this study was to investigate the effect of static magnetic fields (SMF) on reactive oxygen species induced by X‐ray radiation. The experiments were performed on lymphocytes from male albino Wistar rats. After exposure to 3 Gy X‐ray radiation (with a dose rate of 560 mGy/min) the measurement of intracellular reactive oxygen species in lymphocytes, using a fluorescent probe, was done before exposure to the SMF, and after 15 min, 1 and 2 h of exposure to the SMF or a corresponding incubation time. For SMF exposure, 0 mT (50 µT magnetic field induction opposite to the geomagnetic field) and 5 mT fields were chosen. The trend of SMF effects for 0 mT was always opposite that of 5 mT. The first one decreased the rate of fluorescence change, while the latter one increased it. Bioelectromagnetics 34:333–336, 2013. © 2012 Wiley Periodicals, Inc.     

Crystallographic studies on E. coli Trp aporepressor

Two crystal forms of Trp aporepressor, an inactive, unliganded form of Trp repressor have been obtained which are suitable for high resolution X-ray diffraction analysis. Trp aporepressor crystallizes in two forms: orthorhombic, P 2(1)2(1)2 and tetragonal P 4(1) (or P 4(3] which diffract to 1.8 A and 2.4 A, respectively. The orthorhombic crystals contain one monomer in the asymmetric unit, therefore the twofold axis relates two subunits of the dimer as in the case of the previously described Trp repressor (R. Schevitz et al., 1985, Nature, 317, 782-786) and Trp pseudorepressor (C. Lawson & P. B. Sigler, 1988, Nature, 333, 869-871). The tetragonal crystals have two dimers in the asymmetric unit and are nearly isomorphous with the tetragonal crystals of Trp repressor and Trp pseudorepressor grown under similar conditions but in the presence of an activator or inhibitor, respectively.     

ESR evidence of superoxide radical dismutation by human ceruloplasmin

The formation of the paramagnetic complex between human ceruloplasmin and radiation produced superoxide radicals was observed by the ESR method at low temperatures. The disappearance of the complex without changes in the oxidation state of copper give the direct evidence that ceruloplasmin, the major antioxidant in serum, is able to dismutate superoxide radicals.     

Analysis of dynamics trajectories of DNA and DNA - drug complexes

A FORTRAN-77 program is described which was applied for analysisof optimized structures and computer-generated dynamics trajectoriesof DNA and DNA -drug complexes. The CORDAN program (coordinatesanalysis) also can be used for various manipulations of DNA-drugcomplexes, i.e. inversion of asymmetric sites or rebuildingthe structure of the intercalator, among others. These procedurescan find application in drug design. Analysis of dynamics trajectoryof neocarzinostatin antibiotic (NCS) intercalated to the A-DNAform of 5'GGATGGGAG: 5'CTCCCATCC is presented. The proceduresdescribed can be used for detailed analysis of dynamics structuresof DNA and their complexes with intercalating drugs. Received on December 20, 1988; accepted on June 27, 1989