Polyphasic Taxonomic Analysis Establishes Mycobacterium indicus pranii as a Distinct Species

that integrate its phenotypic, chemotaxonomic and molecular phylogenetic attributes..

Vaccines against fertility

The first evidence for the efficacy of a birth control vaccine in humans is now available from the Phase II trials on the human chorionic gonadotrophin vaccine in India. Several sperm antigens have been identified as potential contraceptive immunogens and zona pellucida antigens have been reported that reversibly control fertility

Mechanism of phagocytosis by Schwann cell

33B rat Schwannoma cell line is known to exhibit phagocytic properties analogous to those of normal Schwann cells. The mechanism of phagocytosis by this cell line was investigated by studying the effect of known modulators of phagocytosis on the uptake of latex particles by these cells. Treatments which block energy production of the host cell, such as incubation at 4°C and treatment with sodium azide, markedly inhibited the phagocytosis of latex particles by these cells. Phagocytosis was dose-dependently, and completely, inhibited by cytochalasin B, demonstrating an important role of microfilaments. Colchicine produced a minor inhibition of phagocytosis only at the highest concentration (10−3 M) tested, suggesting that intact microtubules are not crucial for latex phagocytosis. Dibutyryl cyclic AMP was without any effect on the phagocytosis. Thus, latex phagocytosis by rat Schwannoma cells is an active, energy-dependent process requiring intact microfilaments with only a minor dependence on microtubules

Inhibition of the interaction of mycobacteria with Schwann cells by antimycobacterial antibodies

The effect of antimycobacterial serum on the uptake of Mycobacterium w by 33B rat Schwannoma cell line and rat peritoneal macrophages was studied. Incubation of Mycobacterium w with antimycobacterial serum caused a marked inhibition of its uptake by 33B cells but did not diminish its uptake by macrophages. These rsults suggest that the mechanism of the interaction of mycobacteria with Schwann cells differs from that with macrophages

Influence of serum proteins on the kinetics of attachment of vero cells to cytodex microcarriers

The attachment characteristics of the Vero cell line on microcarriers has been found to be influenced by the serum proteins. Significant quantities of serum proteins were found to be adsorbed on the carrier surface, which resulted in decreased exchange capacity and a lower attachment rate constant. The kinetics of attachment followed primarily first order with respect to the concentration of free cells. With positively charged microcarriers the attachment process exhibited two distinct phases, an initial phase of normal attachment followed by a second phase characterized by a lower rate of attachment. The attachment rate constant in the first phase (0.062 min−1) was reduced to 0.01 min−1 in the second phase. Presumably, at a low concentration of free Vero cells, the attachment process is retarded by unadsorbed Bovine Serum Albumin (BSA) and other serum proteins present in the medium

Functional morphology of testis and its excurrent ducts in rats immunized with synthetic luteinizing hormone releasing hormone conjugated to tetanus toxoid

The effects of active immunization against luteinizing hormone releasing hormone (LHRH) on the testis and its excurrent ducts in rats were studied using a synthetic LHRH peptide conjugated to tetanus toxoid (TT), with or without an adjuvant. The study demonstrated that LHRH-TT given alone did not elicit an appreciable immune response and that its immunogenicity could be enhanced by administration with an adjuvant, such as species-specific IgG or SPLPS. The anti-LHRH antibody response showed a corresponding regressive effect on the morphology of the testis and its excurrent ducts. The functional involution of the testis was reflected in the form of a block in spermatogenesis and the lowering of testosterone production; the basic structural organization of the testicular components was, however, maintained. Epididymal ducts displayed rather drastic atrophic changes, indicating that prolonged immunization may result in irreversible damage to the excurrent ducts and could, therefore, adversely affect the restoration of fertility even after the return of testicular function following decline in the immune response against LHRH. This could be an important consideration if LHRH immunization is to be used for male contraception

Some aspects of the influence of hydrostatic pressure on reactions catalysed by enzymes

1. 1. Hydrostatic pressures influence enzymatic reactions in three ways: a. Low pressures accelerate the rate of enzymatic reaction. b. Relatively higher pressures slow-down the reaction rate without totally denaturing the enzyme. c. Very high pressures arrest the evolution of enzymatic reactions, inactivating the enzyme. 2. 2. It has been seen that in conditions of excess of substrate, ΔV=−13.7 ml./mole for the hydrolysis of denatured serum albumin by trypsin. For the same system ΔV in conditions of nonexcess of the Substrate=−2.9 ml./mole. 3. 3. The acceleration of enzymatic reaction under low pressures is then due to the fact that the process of activation of the complex taking place with a diminution of volume is favored under pressures of this order. When the value of pressure applied increases, the formation of the complex ES is inhibited, and we thus observe an overall slowing down of the reaction rate. 4. 4. Very high pressures inactivate the molecule of enzyme. This denaturation is different from the denaturation caused by heating, as evidenced by immunochemical assays. 5. 5. From the effects of pH on the influence of pressure on the reaction starch-amylase, it is deduced that the molecule of salivary amylase carries a negative charge in its active state. The high denaturing pressures will be acting on a reversibly inactive form of the amylase in constant equilibrium with the active form

Screening for autoantibodies in human subjects immunized with Pr-β-HCG-TT

Sera from 3 human volunteers immunised with Pr-β-HCG-TT vaccine were tested for possible reactivity with other human tissues. They were found to be negative for antinuclear, antimicrosomal antibodies and rheumatoid factor. The sera from these subjects did not give any reaction with human thyroid, pituitary, parathyroid, adrenal, testes and ovaries as examined by immunofluorescence techniques. They were also devoid of reaction with tissue substrates from baboons, mice and rabbits

A novel computer modeling approach to the structures of small bioactive peptides: the structure of gonadotropin releasing hormone

A novel computer modeling approach suitable for the structure analysis of small bioactive peptides has been developed. This approach involves identification of conformational patterns in protein structure data bank based on the sequence homology with the bioactive peptide. The models built on the basis of this homology and having common conformational patterns are analyzed under the structural constraints derived from the activity data of various synthetic analogs of the peptide. Application of this procedure to the gonadotropin releasing hormone (GnRH) resulted in a library of possible structures for GnRH, 9 among which shared a common β-turn. Further analysis of the structures containing the β -turn motif, in the context of the structure-activity data, led to a model for the active conformation of GnRH. The topology of the putative receptor binding site of the hormone is defined by a contiguous surface formed through an appropriate juxtaposition of the N-terminal pGlu 1 the guanidyl group of Arg8, aromatic side chain of Trp3, and the Gly 10-NH2 at the C-terminal end

Expression of NEU/HER-2 oncoprotein (p185<SUP>neu</SUP>) in prostate tumors: an immunohistochemical study

The expression of the neu oncogene product was investigated immunohistochemically in 36 cases of benign prostatic hyperplasia (BPH) and seven cases of adenocarcinoma of prostate (CaP). c-neu oncogene encodes a transmembrane growth factor receptor that has partial structural homology with EGF receptor, and is overexpressed and amplified in a number of human tumors, specially, breast cancers. Using a monoclonal antibody, AB-3, which recognizes -COOH-terminal of neu oncoprotein, we have analyzed immunohistochemically the expression of this protein in buffered formalin and Zamboni fluid-fixed surgically removed tissues. Focal patchy and/or diffused cytoplasmic staining of varying intensity was observed in 34 of 36 BPH cases. Four cases showed cell membrane staining as well (4/36=11%). All seven cases of adenocarcinomas had moderate to strong c-neu immunoreactivity, and two gave a distinct cell membrane-positive reaction (100%). The available data indicate that prostatic tumors as well as a high percentage of prostatic hyperplasia tissues express c-neu protein; however, its role in cellular proliferation needs further study