Determination of esterase activity of human and animal serine proteinases using fluorogenic esters of amino acids as substrates]

Two fluorogenic derivatives of amino acids are proposed as substrates for the purpose of enzymatic assay: N-benzyloxycarbonyl-phenylalanine-4-methyl umbelliferyl ester (substrate-1) and tert-butyloxycarbonyl-alanine-4-methyl-umbelliferyl ester (substrate-II). Chymotrypsin-like (hydrolysis of substrate-1), elastase-like (hydrolysis of substrate-II) esterase activity of bovine pancreatic chymotrypsin, activities of cathepsin G and elastase from human, porcine and rat neutrophils and esterase activity of human, porcine and rat serum were assayed. Differences in the level of chymotrypsin-like and elastase-like activities of human, porcine and rat serum were established. Activities of purified elastase and cathepsin G from human and animal neutrophils were shown to have no significant distinctions.     

pH track of expanding bacterial populations

A method of pH distribution measurements in agar nutrient media containing expanding bacterial populations is described. It is based on measuring pH microsamples taken at different points of the media. The sample volume was 10 microliters. A pH sensitive field effect transistor was used as a measuring electrode. Acidification was found to occur in glucose media, while alkalization occurred in the media containing peptone.     

Transfusion-induced immunomodulation and its possible role in cancer recurrence and perioperative bacterial infection

Over the last decade, it has become evident that homologous transfusions carry immunologic consequences beyond the well-understood ones of alloimmunization to blood cell antigens. Transfusions constitute temporary transplants of large amounts of allogeneic antigen given intravenously and cause down-regulation of many cellular immune functions. These changes may explain in part the association of transfusion with such clinically important events as (1) improved survival of renal allografts, (2) decreased recurrence rates for autoimmune disease, (3) increased frequency and earlier recurrences of solid tumors, (4) increased frequency of post-operative bacterial infection, and (5) increased severity of viral infection. Preliminary data suggest that, in animal models and clinical settings, syngeneic or autologous transfusions are not associated with such events. This finding supports the hypothesis that these associations are cause and effect and involve immunologic mechanisms.     

Characterisation of Pseudomonas rhamnolipids

The Gram negative organism, Pseudomonas aeruginosa, is often found in the lungs of patients with cystic fibrosis and other forms of severe bronchiectasis, where it secretes a number of extracellular toxins including the mono- and dirhamnolipids. The principal monorhamnolipid from P. aeruginosa has previously been identified as rhamnosyl-3-hydroxydecanoyl-3-hydroxydecanoate (Rh-C10.C10). A number of related mono- and dirhamnolipids have been purified from cultures of a clinical isolate of P. aeruginosa and identified by fast atom bombardment and electron impact mass spectrometry: these contain the 3-hydroxyoctanoyl-3-hydroxydecanoate (C8.C10) and 3-hydroxydecanoyl-3-hydroxydodecanoate (C10.C12) homologues. Structural isomers were also present where the order of the lipid linkage was transposed (Rh-C10.C8 and Rh-C12.C10). Unsaturated mono- and dirhamnolipids containing the 3-hydroxydecanoyl-3-hydroxydodec-5-enoate (C10.C12:1) lipid were also present.     

The study of nucleoside triphosphate-binding center of DNA-dependent RNA-polymerase of phage T7 using GTP analogs

The NTP binding site of bacteriophage T7 DNA-dependent RNA polymerase was studied using GTP analogs. For four analogs the irreversible inhibition was demonstrated. The kinetic parameters for competitive (Ki) and irreversible (KI and k3) inhibition were determined. One of the analogs, 5'[2-hydroxy(4-iodoacetamido)benzoyl]guanosine, was shown to inactivate the enzyme rapidly due to the modification of SH-groups. Some suggestions on the structure of the RNA polymerase active site have been made.     

Curvularia clavata as an aetiological agent of human skin infection

Curvularza cfavata was cultured from skin lesions in a 20-year-old female. The morphological characteristics of the isolate are described. The isolate was sensitive to clotrimazole at a minimum inhibitory concentration of 5 μg/ml.     

Comparative study of the changes in microanatomical organization of lymph nodes located and functioning in the area of venous congestion

By the morphometric method the microanatomical organization of the popliteal and kidney lymph nodes of the type Vi was studied in venous congestion. In the first experimental series (lymph nodes localize in venous congestion area) the venous congestion in the popliteal lymph nodes was created by the ligature of caudal vena cava. In the second experimental series (lymph nodes, which clean the venous congestion area--the kidney vena was tied up. The small and short time increase of the marginal sinus volume and hypertrophy of the medullary cords, which seemed about medullary substance B-zone stimulation were characteristically for the lymph nodes, localize in the venous congestion area. The sharp increase of the marginal sinus volume during the long experimental time and paracortical T-zone hyperplasia were characteristically for the lymph nodes, which clean the venous congestion area.