Search PubMed⌕ Search

Biomedical subjects

A Thomas

Publications and source records attributed to A Thomas.

At least 541 records · Page 30Linked to original sources
PubMed1979

A comparison of the initiation factors of eukaryotic protein synthesis from ribosomes and from the postribosomal supernatant.

A purification procedure is described for the initiation factors of protein synthesis from rabbit reticulocytes: (a) from the ribosomal wash and (b) from the postribosomal supernantant. A comparison is made between these preparations with respect to yield and specific activity. eIF-4A and eIF-4D occur mainly in the postribosomal supernatant; eIF-2, eIF-4C and eIF-5 are more evenly divided over both fractions, whereas eIF-1, eIF-3 and eIF-4B are found almost exclusively in the ribosomal wash. No significant difference in specific activity could be detected when factors from both sources were compared, with a possible exception of eIF-4A and eIF-4D.

Animals↗
PubMed1979

Adrenocorticotrophin-related peptides in adult and foetal sheep pituitary glands.

Differences in foetal and adult adrenal function may be due to qualitative as well as quantitative changes in the pituitary corticotrophic stimulus. Pituitary glands from adult and foetal sheep were freshly dissected and stored at -70 degrees C until extracted at pH 1.5. The extracts were subjected to chromatography on Sephadex G-100 superfine and fractions were assayed by multiple radioimmunoassays directed against the NH2- and CO2H-terminal sequences of ACTH and lipotrophin (LPH). Peaks corresponding to beta-melanocyte-stimulating hormone (beta-MSH), beta-LHP, gamma-LPH, beta-endorphin and ACTH were identified, with little or no evidence for the presence of alpha-MSH and corticotrophin-like intermediate lobe peptide. Three peaks of large molecular weight material, A. B and C, were identified and their relative proportions shown to be considerably greater in the foetus than in the adult. The immunoassay profile of peaks A and B suggested that they were 'stem hormones' which could give rise to a family of biologically active peptides. Since the 'family tree' which they engender varies according to the stage of development, it is proposed that the changes in the 'trophic family' may explain the different adrenal responses of the foetal and adult sheep.

Adrenocorticotropic Hormone↗
PubMed1979

Aerobic and anaerobic bacterial flora in semen from fertile and infertile groups of men.

Semen samples were collected by masturbation under asceptic conditions from men who had sired children within the past 6 mo (group A) and asymptomatic men attending an infertility clinic who had not sired children and whose wives were asymptomatic for infertility (group B). These 109 semen samples were analyzed and cultured for isolation of aerobic and anerobic organisms. Overall, 68% of the specimens had positive bacterial cultures: 54% of the samples from group A were positive and 73% from group B were positive. Mixed bacterial flora were isolated from both groups but in group B they were more varied and present in a higher colony count than in group A. Staphylococcus epidermidis, Staph. aureus, Corynebacterium species, Mycoplasma hominis, and Ureaplasma urealyticum were isolated from group A. Group B revealed these organisma plus Streptococcus pneumoniae type III, Strep. pyogenes group A, Strep. feacalis, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Candida albicans, Bacteroides species, Peptostreptococcus species, and Eubacterium species. Semen samples from group A were of better quality than those from group B. In addition, the antibacterial effect of seminal plasma from group A was greater than that from group B.

Adult↗
PubMed1979

Cyclophosphamide-sensitive and cyclophosphamide-resistant suppressor cells in the immune response to alloantigens.

We have demonstrated that within a given system Cy may alter the immune response in different ways. It may augment the response by inactivating CSS cells or induce immunosuppression by activating CRS. Furthermore, our studies provide a means of analyzing the mechanism of suppression, that is, delineating the target cell for suppression, the properties and life span of the suppressed cells, and the nature of the cell interactions involved. Furthermore, with the available information on the immunosuppressive activity of Cy, clinical studies may be best monitored in transplantation immunology and tumor chemotherapy. It is possible that the induction of CRS cells, which are antigen-nonspecific and non-H-2-restricted, may be useful for inducing specific immunosuppression to alleviate GVH reactions. These studies are currently in progress.

Animals↗
PubMed1978

Ureaplasma urealyticum (T-mycoplasma) in vaginal fluid and cervical mucus from fertile and infertile women.

Ureaplasma urealyticum (T-mycoplasma) was isolated more frequently and in heavier growth from cervical mucus (49%) than from vaginal fluid (34%). It was isolated in 24% of vaginal fluid samples and in 35% of cervical mucus samples from fertile women, and in 29% of vaginal fluid samples and in 47% of cervical mucus samples from infertile women. The incidence of infection was high following abortion or total hysterectomy and during pregnancy or oral contraceptive use. T-mycoplasma was also isolated from the vaginal fluid and cervical mucus of a woman with tubo-ovarian abscess, but was not present in women with Trichomonas vaginalis infection. U. urealyticum did not alter the physiophysiologic characteristics of vaginal fluid and cervical mucus or the sperm penetration and sperm viability in cervical mucus. Treatment with tetracycline eradicated the organism in 88% of the infected women. Pregnancies were recorded during a 6-month follow-up in 1 of 19 infertile women who were treated with tetracycline.

Cell Survival↗
PubMed1978

Further epidemiological evaluation of a malaria model.

The malaria model previously fitted to 1 year of baseline data from the Garki District in the Sudan savanna of northern Nigeria was tested against data collected in the same area over a period of 3 years, including 1(1/2) years during which the insides of houses in certain villages were sprayed with propoxur. It was also tested against data collected in Kisumu, Kenya, also over a period of 3 years, including 20 months during which the insides of houses in part of the area were sprayed with fenitrothion. The test consisted in using the vectorial capacity, calculated from the entomological observations made in the above places and periods, as input in the Garki model while keeping the other parameters as fitted to the Garki baseline data, and in comparing the prevalence of Plasmodium falciparum parasitaemia as estimated by the model to that actually observed. There was relatively good agreement and the model is considered epidemiologically satisfactory and fit for use in planning malaria control operations.

Adolescent↗