Density functional theory-based conformational analysis of a phospholipid molecule (dimyristoyl phosphatidylcholine).

The conformational space of the dimyristoyl phosphatidylcholine (DMPC) molecule has been studied using density functional theory (DFT), augmented with a damped empirical dispersion energy term (DFT-D). Fourteen ground-state isomers have been found with total energies within less than 1 kcal/mol. Despite differences in combinations of their torsion angles, all these conformers share a common geometric profile, which includes a balance of attractive, repulsive, and constraint forces between and within specific groups of atoms. The definition of this profile fits with most of the structural characteristics deduced from measured NMR properties of DMPC solutions. The calculated vibrational spectrum of the molecule is in good agreement with experimental data obtained for DMPC bilayers. These results support the idea that DMPC molecules preserve their individual molecular structures in the various assemblies.

Distinct vascular zones in the canine prostate.

The vascular bed of canine prostate was studied and detailed distinct vascular zones were visualized on corrosion casts by scanning electron microscopy. This study was performed because of scarce information about the zonal vascularization of the prostate gland in dogs. There are no studies for three-dimensional microvascular distribution of the capsular vessels and the capsular microvascular trabeculae. SEM (vascular corrosion casting method) was used to show 3D angioarchitecture of the prostate gland. The lobules on the dorsal and lateral surface of the gland were numerous but small. Their small size is probably due to the abundant blood supply in the region. Few but large ventral lobules were observed. Three prostatic zones were clearly defined: capsular, parenchyma, and urethral. The diameter of the venous blood vessel compared to arterial vessels of the capsule was smaller. Two types of arteries were observed in trabeculae: direct and branched. The direct arteries were straight, with only a few branches. The branched arteries contained many bifurcations, with the vessel's diameter decreasing gradually. The trabeculae capillary network formed loops, with frequent sphincter-like constrictions and pouch-like protuberances.

Experimental mycotoxicosis in chickens induced by ochratoxin A and penicillic acid and intervention with natural plant extracts.

The combined toxic effect of ochratoxin A (OTA) and penicillic acid (PA) on the body mass, the weight and pathomorphology of some internal organs was studied in 85 broiler chickens fed a mouldy diet containing 130, 300 or 800 ppb OTA and 1000-2000 ppb PA. The main pathomorphological changes were cloudy swelling and granular degeneration in the epithelium and mononuclear cell proliferation and activation of capillary endothelium in the kidney and liver; degenerative changes and depletion of lymphoid cells in lymphoid organs (bursa of Fabricius, thymus and spleen) were also seen. Protective effects of 5% total water extract of artichoke and a new natural phytosubstance Rosallsat against these pathomorphological changes were observed. A significant decrease in body mass and relative weight of lymphoid organs was found after 6 weeks of exposure and a greater decrease after 10 weeks of exposure to OTA and PA, and a protective effect of artichoke extract and a slight effect of Rosallsat against that decrease was observed. A significant increase in relative weight of liver and kidneys was also observed as well as a protective effect of artichoke extract against that increase. The quantity of OTA and the percentage of positive samples were significantly lower in tissues of chickens treated with artichoke extract or Rosallsat in addition to OTA than in those treated with only OTA.

[Effect of varying alloxan concentration on serum levels of glucose, calcium and alkaline phosphatase in the rat]. / Vliianie razlichnykh kontsentratsii alloksana na soderzhanie gliukozy, kal'tsiia i aktivnost' shchelochnoi fosfatazy v syvorotke krovi krys.

Two groups of rats were injected intravenously 20 and 40 mg alloxan/kg of body weight respectively. It was shown that different doses of alloxan induced the increase of glucose concentration, activity of alkaline phosphatase and decrease of calcium level in the rat serum. The above changes more expressed in the groups of rats that received the higher dose of alloxan.

[Features of vitamin D3 metabolism in liver cells in experimental diabetes mellitus]. / Osobennosti obmena vitamina D3 v kletkakh pecheni pri éksperimental'nom sakharnom diabete.

The uptake of vitamin D3 by the liver cells and its hydroxylation in the hepatocytes of rats at experimental diabetes has been studied. It is proved that in this pathology the disturbances of vitamin D3 exchange in the rat liver take place. It is concluded that the lowering of the level of absorption of vitamin D3 by hepatocytes and its transportation to these cells from reticulocytes as well as the inhibition of vitamin D3-25-hydroxylase liver systems can be the most probable cause of these disturbances.

[Vitamin D-dependent protein of smooth endoplasmic reticulum membranes of rat enterocytes]. / Vitamin-D-zavisimyi belok membran gladkogo éndoplazmaticheskogo retikuluma énterotsitov krys.

DEAE-cellulose chromatography and SDS-PAAG electrophoresis were used to study proteins from endoplasmic reticulum of smooth and rough enterocyte membranes in the vitamin D-replete and deficient rat. The membrane-bound vitamin-D-dependent protein with a molecular weight of 21-25 kDa is shown to consist of the endoplasmic reticulum of smooth membranes. The intensive binding of calcium by these membranes is established.

[Lipids and proteolipids in membranes of the smooth endoplasmic reticulum of rat enterocytes. Vitamin D-dependent calcium binding]. / Lipidy i proteolipidy membran gladkogo éndoplazmaticheskogo retikuluma énterotsitov krys. Vitamin D-zavisimoe sviazyvanie kal'tsiia.

The lipid and proteolipid composition of endoplasmic reticulum smooth membranes from rat enterocytes in normalcy and under D-hypovitaminosis is studied to show the Ca2+-binding with these components. These membranes in vitamin D-deficiency are established to differ in the cholesterol content. Proteolipids 1 and 2 are isolated from the lipid fraction of membranes. Their amino acid composition is determined. The vitamin D-dependent binding of Ca by the proteolipid fraction is shown.

[Sensitivity of Salmonellae isolated from poultry to bacteriophage O1]. / Chuvstvitelnost na salmoneli, izolirani ot ptitsi, kum bakteriofag O1.

Studied were a total of 200 bacterial strains that agglutinated with the group B, C, D and E Salmonella sera. The organisms were isolated from viscera (liver, gallbladder, spleen, ovaries, and heart) and bone marrow from dead birds, from embryos, eggs, and washings from hatcheries, etc. in 1982-1985 in the district of Stara Zagora. It was found that the strains behaved biochemically as typical Salmonellae. Serologically typed of group B were 40 strains (S. typhimurium--34, and S. lagos--6); of group C--61 strains (S. oranienburg--38, S. isangi--7, S. montevideo--4, Salmonella II 6.7:gmst: 1.5--5, S. thompson--2, and S. newport--5); of group D--89 strains (S. gallinarum--57, S. gallinarum var. duisburg--23, S. pullorum--1, and S, enteritidis--8); and of group E--8 strains (S. senftenberg--4, S. anatum--4). Two of the strains were in the R form. Sensitive to the phage proved 89 +/- 5.7 per cent of the strains including the two R-form ones and those that were resistant of group C (S. oranienburg--5.4 per cent) and of group D (S. gallinarum--23 per cent, and S. gallinarum var. duisburg--26.1 per cent). The high sensitivity to the phage substantiated the phage identification of the strains as an adjunct, supplementary method in the complex diagnostics of diseases of a Salmonella etiology after the preliminarily determined phage for the respective region was made known.

[Sensitivity of salmonellae isolated from poultry to drugs]. / Chuvstvitelnost na izolirani ot ptitsi salmoneli kum lekarstveni sredstva.

Studied were a total of 125 Salmonella strains, isolated from birds, with regard to their sensitivity to medicinal drugs. A 100 percent effect against these organisms was found with amopen, neomycin, borgal, and sumetrolin. The effect was 97.7 per cent with canamycin, gentamycin, and terramycin; it was 95.5 per cent with the use of streptomycin, spectam, and chloramphenicol, 72.4 per cent--with tetracyclin, 70.5 per cent--with nalidixic acid, and 47.7 per cent--with sulfathiazol. Resistance of the strains to carbenicillin was 83 per cent, to ampicillin--79.6 per cent, and to sulfathiazol--38.6 per cent. It was interesting to note that resistance to carbenicillin and nalidixic acid, used in human medicine only, was 82.6 and 4.54 per cent, respectively. The high susceptibility of Salmonellae to amopen, and the limited capacity of the organisms to produce resistant strains outline the perspective of its wide use in the control of Salmonella infections in birds.

[Vitamin D3 transport across the intestines and its metabolism in the liver of rats with alloxan diabetes]. / Transport vitamina D3 cherez kishechnik i ego obmen v pecheni krys pri alloksanovom diabete.

Vitamin D3 intestinal transport and liver metabolism were studied in rats with alloxan-induced diabetes. The condition was induced by i.v. alloxan injection in a dose of 40 mg/kg b.m. Diabetes development was monitored by blood serum glucose measurements, carried out for 30 days. [3H]-cholecalciferol absorption in the rat intestine was found inhibited in the diabetic animals as against the reference animals, which fact results in disordered entry of vitamin D3 to the body. [3H]-cholecalciferol absorption by the liver is reduced in the examined condition, and the time of its metabolism is increased more than threefold as against the reference animals. The share of vitamin D3 hydroxylation by the liver of diabetic rats is also significantly reduced. The described disorders are responsible, among other things, for the reduction of the levels of vitamin D3 active metabolites in the blood serum of rats with experimental diabetes.

Effect of anticoagulation and lavage prior to casting of postmortem material with Mercox and Batson 17.

In this study we compare the quality of vascular casts, obtained from organs of several animal species from different sources and sacrificed under different conditions. Organs from healthy animals were injected with two different polymers such as Mercox and Batson No. 17. When the specimens were observed under a scanning electron microscope structural elements such as endothelial nuclear impressions on vessels and capillaries, endothelial cell borders, venous valves, imprints of smooth muscle cells and intra-arterial cushions were identified. Organs excised post mortem from large animals can be used for microvascular corrosion casting studies with optimal results.