Cytobios最新文献

The effect of low temperature preservation on the motility and morphology of acrosomes, acrosomal proteolytic activity, phospholipid and fatty acid composition of phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE), and the cholesterol/phospholipid molar ratio in sperm from rams housed in the highlands or in the valleys, were studied. The indices of motility and morphological integrity of sperm from highland rams were much greater compared with those of valley rams. Phosphatidyl choline (PC) of the highland rams was more unsaturated, while PE was more saturated compared with those of valley rams. Cryopreservation of the sperm from highland rams significantly increased the content of choline plasmalogen, accompanied by a slight rise in the levels of lysophosphatidyl choline (LPC) and phosphatidyl inositol (PI) in their sperm. The fatty acid composition altered following cryopreservation. These variations were mainly due to a decrease in the amount of docosahexaenic acid and an increase in the amounts of linoleic and palmitic fatty acids. The results may be indicative of the fact that the alterations in the sperm of the valley rams were more pronounced and they may be attributed to the structural features of the sperm, as well as a reduced concentration of oxygen in the organs and tissues of the highland rams.

The expression of high- and low-molecular weight acid phosphatase (HMr- and LMr-AP) and zinc ion-dependent acid phosphatase (HMr-ZnAP and LMr-ZnAP) was compared in normal human liver and in Hep G2 human hepatocarcinoma cell line extracts. The investigation was carried out using Sephadex G-100 chromatography, molecular weight determination, and analysis of some distinctive biochemical characteristics and immunochemical properties. Normal human liver and Hep G2 cell lines expressed both HMr- and LMr-AP enzymes although in different proportions. HMr-ZnAP was detected only in human liver extract, while LMr-ZnAP was present only in hepatoma cell extract, indicating that they were differentially expressed in normal and transformed human liver cells.

A study using transmission electron microscopy (TEM) of the spermatozoa of Rana tigrina and Heteropneustes fossilis in all phases of the annual reproductive cycle revealed that there was a phylogenetic relationship between them. The spermatozoa of H. fossilis appeared horseshoe-shaped, somewhat oval or wedge-shaped at the anterior end and broader at the posterior end. The horseshoe-shaped spermatozoan nucleus was observed during spermiogenesis of R. tigrina but later changed into a finger shape at maturity. The posterior end of the nuclei of mature spermatozoa of R. tigrina was blunt. The extremely dense homogenized nucleus was capped with an acrosomal vesicle in both species suggesting a definite phylogenetic inter-relationship between them.

Protozoa of the genus Leishmania infect reticuloendothelial cells of several mammalian species, including dogs, in which they often give rise to a chronic, not self-healing visceral disease. The parasitocidal mechanism of peripheral blood monocytes towards Leishmania in the dog has not been investigated in detail. Consequently, Leishmania infantum-infected monocyte cultures of healthy dogs were evaluated using the following parameters: (1) phagocytosis and killing capacities; (2) oxidative burst, in terms of superoxide anion (O2-) release, and (3) nitric oxide (NO) activity, in terms of nitrite (NO2-) production in the presence or absence of the NO synthase inhibitor NG-monomethyl-L-arginine (NGMMLA). Parallel experiments were performed on monocytes stimulated with supernatants of concanavalin A-activated PBMC and on unstimulated monocytes. The amount of IFN-gamma in PBMC supernatants used for monocyte activation was determined by a biological assay on a canine Madin Darby cell line. Results demonstrated that phagocytosis, killing capacity and O2- production significantly increased in monocytes stimulated with supernatants, in comparison with unstimulated cells. A positive correlation was observed between the killing capacity, the O2- production and the amount of IFN-gamma in PBMC supernatants employed for monocyte activation. No significant differences were observed in NO production between unstimulated and stimulated cultures, or between the same cultures with and without NGMMLA. Finally, the killing percentage was similar in the presence or absence of NGMMLA, suggesting that in this experimental model peripheral blood dog monocytes lack NO-mediated killing.

Volume changes were originally used for studying the dynamic properties of glucose transport in red cells. As an extension it has been found possible to examine the interplay of three functional proteins evolved for the physiological role of human erythrocytes in transporting carbon dioxide and bicarbonate. The proteins chiefly concerned in this investigation were the cytoplasmic carbonic anhydrase and the two membrane transporting proteins, namely the band 3 anion exchanger and the unique bicarbonate transporter, which are distinct from the anion exchanger. The rates of anion membrane transport measured and the volume changes may be more than two orders of magnitude faster than those which regulate cationic movement in red cells, but this may only be an adaptation for the physiological role of red cells. The new concepts derived from the studies and their possible wider applications to physiological mechanisms are briefly discussed.

The effect of thyroid stimulating hormone (TSH) or thyrotropin (0.06, 0.6, 6, and 60 microIU/ml), follicle stimulating hormone (FSH) and luteinizing hormone (0.1, 1, 10, and 100 mIU/ml) on soluble interleukin-2 receptor (sIL-2R) release in vitro from resting or phytohaemagglutinin (PHA) activated human peripheral blood mononuclear cells (PBMC) was evaluated. sIL-2R concentrations were measured in supernatants of cultured cells by quantitative sandwich enzyme immunoassay method (ELISA). TSH in a dilution of 0.6 microIU/ml and FSH in a concentration of 1 mIU/ml inhibited the secretion of sIL-2R only (p < 0.01) into supernatants from PHA activated PBMC cultures.

In this study 315 individuals (25 controls, 290 chemically sensitive immunocompromised patients) were investigated. Each patient had been on a standard therapy of avoidance of pollutants, nutritional supplementation, and injections of antigens for foods, and biological inhalants, but did not attain their immunological competence. Peripheral lymphocytes were collected and DNA histograms were constructed. The flow cytometer was used to evaluate the cell cycle, haematological, and other immunological profiles. From the other portion of the blood specimen, lymphocytes were propagated in vitro, harvested, and a lysate, termed the autogenous lymphocytic factor (ALF), was prepared. When treated with ALF, 88% of these individuals showed a significant (p < 0.001) clinical improvement which correlated with laboratory findings, involving regulation of abnormal cell cycles, increase in total lymphocytes and subsets T4, T8, (p < 0.05) and cell mediated immunity (CMI) response (p < 0.001). The ALF presumably acts as a biological response modifier. The cell cycle and ALF provide clinical tools for diagnosis and regulation of immunological incompetence.

Molecular cytogenetics using fluorescent in situ hybridization (FISH) is an extremely useful adjunct technique to conventional cytogenetics via GTG-banding. The present paper illustrates the utility of FISH by describing a patient with myelodysplastic syndrome (MDS) who was initially studied using GTG-banding and whose bone marrow was found to be populated with hyperdiploid cells. FISH was used to delineate the numerical and structural chromosomal abnormalities. It revealed the presence of trisomy 8 and determined that the previously unidentifiable marker chromosome was of chromosome 10 origin. Although trisomy 8 is a frequent finding in MDS, the structural chromosomal abnormality of chromosome 10 as reported here is not a common finding.

When cells of Saccharomyces cerevisiae ale strain C1028 were grown aerobically, ethanol production displayed a hyperbolic increase over a limited range of magnesium concentrations up to approximately 0.7 mM. Entry of cells into the stationary growth phase and the time of maximum ethanol and minimum sugar concentrations correlated with a period of maximum Mg2+ concentration in the growing media. It is suggested that magnesium accumulation by yeast cells may be usefully exploited in biotechnology concerned with the production of beer.

The genotoxic effect of polycyclic aromatic hydrocarbons (PAHs) on somatic human chromosomes obtained from lymphocytes of 49 coal tar workers exposed to 26 micrograms/m3 benzo(a)pyrene, 16 mg/m3 benzene and 0.04 mg/m3 H2S in the ambient air, compared to equal numbers of matched controls breathing air containing 1 microgram/m3 benzo(a)pyrene, 1.5 mg/m3 benzene and 0.02 mg/m3 H2S, was investigated. The mitotic index (MI), chromosome aberrations (CAs), sister chromatid exchanges (SCEs) and satellite associations (SAs) were analysed. All the parameters showed a significant increase (p < 0.01 and 0.05) in the exposed individuals compared with the controls: viz MI, 4.59-7.92; CAs, 0.77-3.0; SCEs, 5.89-6.80; and SAs, 8.18-14.26. The occurrence of the DG type of satellite associations were highest and the 3D type lowest. The frequency of SCEs was highest in coal tar workers with an exposure period of 6-10 years. It is suggested that these results show PAH is genotoxic for humans.