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Biomedical subjects

J D Wilson

Publications and source records attributed to J D Wilson.

At least 235 records · Page 13Linked to original sources
PubMed1987

Partial purification and characterization of dynein adenosine triphosphatase from bovine sperm.

Outer dynein arm polypeptides that possess Mg+2-adenosine triphosphatase (ATPase) activity have been extracted from the flagellar axonemes of demembranated bovine sperm. Electron microscopy of intact and salt-extracted sperm demonstrates a relatively selective removal of the outer dynein arms. The salt extract contains a specific ATPase activity of 55 nmoles inorganic phosphate (Pi)/min/mg protein. Sucrose density gradient centrifugation of this extract results in a 6-fold increase in specific activity of ATPase (333 nmole/Pi/min/mg protein), which sediments as a single 13S peak. Concomitant with the increase in specific activity, there is enrichment of three high molecular weight polypeptides (Mr greater than 300,000) characteristic of dynein heavy chains. ATPase activities in the initial extract and in the 13S peak are inhibited by concentrations of vanadate and erythro-9-[3-2-(hydroxynonyl)]adenine similar to those that inhibit ATPase activity in sea urchin sperm dynein. These findings indicate that outer arm dynein ATPase can be extracted and partially purified from bovine sperm.

Adenosine Triphosphatases↗
PubMed1987

Epidemiological treatment of sexual contacts prevents recurrence of non-gonococcal urethritis.

Of 98 male patients with non-gonococcal urethritis (NGU) who had regular female consorts who received concurrent epidemiological treatment, NGU recurred in four (16%) men whose treated partners were initially chlamydia positive and 20 (27%) men whose treated partners were initially chlamydia negative. Of 32 men whose regular female sexual partners refused to attend, 26 (77%) men suffered a recurrence of NGU. All study patients were selected because they were in monogamous relationships and returned to the clinic either because of a recurrence of NGU or for unrelated reasons at least 12 months after treatment. We recommend the routine epidemiological treatment of all sexual contacts of men with NGU.

Adolescent↗
PubMed1987

Clinical and endocrinological characterization of two subjects with Reifenstein syndrome associated with qualitative abnormalities of the androgen receptor.

The androgen receptor in fibroblasts cultured from a biopsy of scrotal skin from 1 subject with Reifenstein syndrome has been found to be normal in amount and to bind dihydrotestosterone with normal affinity but to be qualitatively abnormal as evident by thermolability and instability upon ultracentrifugation. The family study of this subject and endocrine studies document androgen resistance in the index patient and his affected uncle. These findings provide evidence for X-linkage of this disorder, and suggest that the mutations that give rise to this phenotype are probably allelic to the mutations of the androgen receptor that cause testicular feminization.

Adolescent↗
PubMed1987

Changes in amount and intracellular distribution of androgen receptor in human foreskin as a function of age.

To provide insight into the factors that control growth of the penis we measured the amount and intracellular distribution of specific high affinity androgen receptor in foreskins obtained at circumcision from 49 males varying in age from newborn to 59 yr. Total (cytosolic plus nuclear extract) androgen receptor decreased from approximately 40 fmol/g tissue weight in newborn foreskins to approximately 25 fmol/g by 1 yr of age. The amount of receptor rose in childhood to approximately 180 fmol/g in the late teenage years and fell thereafter to approximately 20-40 fmol/g in men older than 40 yr. The amount of receptor in the nuclear fraction increased at the time of puberty and subsequently decreased in parallel with the decline in total receptor level. These changes in androgen-receptor amount are similar when expressed per milligram DNA or per milligram protein.

Age Factors↗
PubMed1987

Transformation of the androgen receptor to the deoxyribonucleic acid-binding state: studies in homogenates and intact cells.

Transformation of the [3H]dihydrotestosterone-receptor complex to the DNA-binding state was studied in intact monolayers and in homogenates of cultured human fibroblasts and mouse L-cells. When homogenates of either cell type were prepared in low salt buffer, incubated at 0 C with [3H]dihydrotestosterone, chromatographed on DNA-Sepharose, and eluted with a NaCl gradient, the receptor complex was eluted at 25 mM NaCl (peak A). After incubation of the homogenate at 25 C for 20 min, peak A decreased in amplitude. The major peak of the receptor from human fibroblasts eluted at 100 mM NaCl, while that from L-cells eluted at 170 mM NaCl (peak B). Flow-through fractions contained only minimal amounts of transformable dihydrotestosterone-receptor complex under the same conditions. Furthermore, isolated peak A could be converted to peak B by the same warming process. The appearance of peak B was prevented when 10 mM, but not 1 mM, sodium molybdate was present during the homogenization process. Unoccupied receptor was recovered exclusively in peak A both at 0 C and after incubation at 25 C. When intact fibroblast and L-cell monolayers were incubated with [3H]dihydrotestosterone at 37 C, all receptor in both cytosol and nuclear extract was recovered in peak B. In sucrose density gradient centrifugation, peak A was 6-8S in size, and peak B was 4.6S. These findings suggest that peak A corresponds to the nontransformed and peak B to the transformed states of the androgen receptor; the transformation reaction may be the consequence of a dissociation of a macromolecular complex into subunits; and sodium molybdate acts to stabilize the macromolecular complex.

Animals↗
PubMed1987

5 alpha-reduced androgens in the human fetal testis.

The androgen content was measured in testes from 34 male and in ovaries from 30 female embryos that varied in age from less than 12 to approximately 20 weeks. The 5 alpha-reduced androgens dihydrotestosterone and 3 alpha-androstanediol were found in testes at a level of about a 30th of that of testosterone at all ages examined, whereas very little or no testosterone, androstenedione, or either of the 5 alpha-reduced androgens were detected in the ovaries. Whether dihydrotestosterone plays a role in the development of the testes is unknown.

Androstane-3,17-diol↗
PubMed1986

A comparative study of transplant sites for endocrine tissue transplantation in the pig.

Thyroid and thymus tissue autografts were used to examine the suitability of different transplant sites in the pig for endocrine tissue transplantation. The omental pouch, gall bladder fossa and renal subcapsular space showed optimal implantation, preservation and vascularisation of graft tissue. Marked dissemination of graft tissue was observed at intramuscular sites and graft viability at subcutaneous sites in the ear was poor. The omental pouch represents a potentially suitable site for pancreatic islet tissue transplantation studies in the pig.

Animals↗
PubMed1986

Induction and management of diabetes mellitus in the pig.

Insulin-dependent diabetes mellitus was induced in the pig by pancreatectomy or by administration of intravenous streptozotocin (150 mg/kg). High post-operative morbidity and mortality in the pancreatectomised animals made this method of inducing diabetes unsuitable for animals to be used in long term studies. By contrast, the good clinical state of animals after streptozotocin and the permanence of their diabetes indicated that these animals were suitable for long term studies such as those involving transplantation of pancreatic islet tissue. Techniques designed to facilitate the assessment and management of these animals included placement of an indwelling jugular venous catheter to enable blood samples to be obtained for metabolic studies, denervation of an area on the flank of the animal to enable insulin administration with minimum discomfort and denervation of an ear to enable blood samples to be obtained from the animal for glucose estimation in long term studies.

Animals↗
PubMed1986

Application of response-surface methodology to detect interactions of genotoxic agents in cultured mammalian cells.

Response-surface methodology (RSM) techniques provide a useful statistical approach for the design and analysis of experiments involving multiple variables. Although it has been used for some time in the areas of chemical engineering and agriculture, RSM has only recently been applied to the solution of biological problems. Here we have utilized RSM to investigate the interaction of two direct-acting, monofunctional alkylating agents [ethyl methanesulfonate (EMS) and ethylnitrosourea (ENU)] in Chinese hamster V79 cells with respect to the in vitro induction of sister chromatid exchanges (SCEs). A factorial design was employed in which the cells were exposed to the agents singly and in simultaneous combinations for 4 h. The cells were collected for SCE determination 30 h after treatment. The analysis revealed concentration-dependent increases in SCEs for both of the agents, with ENU being the more effective on an equimolar basis. In addition, single- and multiple-agent interactions were detected. The most important finding was that over the treatment range studied, a significant negative interaction occurs between EMS and ENU with regard to SCE induction. It is suggested that RSM not only may be useful in determining the statistical relevance of experimental variables but also may generate hypotheses the evaluation of which could provide additional insights into the underlying mechanisms involved.

Animals↗
PubMed1985

Allergy to basidiospores: immunologic studies.

Fruiting bodies of larger basidiomycetous fungi were collected over a 15 month period from natural habitats and a total of 67 different antigenic extracts were prepared from spores or tissue, in buffered saline, pH8, and standardised at 1:50 and 1:10 (W/V) concentrations. A number of heterogeneous and diagnosed allergic patients were tested by skin prick test method with the extracts of either individual species or mixtures of related species. Up to 22% patients reacted positively, indicating their possible IgE mediated reactions and the allergenic potency of the species involved. The potential allergenicity of many of these genera and/or species has not been reported previously. The findings suggest that basidiospores could be a possible major factor for the high respiratory allergy incidence in the Auckland region and necessitate further investigation.

Adolescent↗