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Biomedical subjects

R A Anderson

Publications and source records attributed to R A Anderson.

At least 289 records · Page 16Linked to original sources
PubMed1985

Partial reversal of ethanol-induced male reproductive pathology following abstinence.

To date, no longitudinal studies have been carried out to determine the recovery of ethanol-related reproductive failure subsequent to moderate periods of abstinence. An animal model (C57B1 mouse) was utilized to examine the effectiveness of abstinence for reversal of ethanol-induced reproductive failure. After treatment with either a 5% (v/v) ethanol diet (10 weeks) or a 6% (v/v) ethanol diet (5 weeks), ethanol-treated animals and their pair-fed controls were electroejaculated and hemicastrated (right testis and accessory organs); their reproductive tracts and epididymal spermatozoa were examined. Ingestion of the 5% and 6% ethanol diets resulted in significantly (P less than 0.05) decreased weights of testes (24% and 28%, respectively) and seminal vesicles/prostate (20%, 6% diet only), increased frequencies of germ cell desquamation (480% and 400%), inactive seminiferous tubules (186% and 567%), sperm dysmorphology (31% and 119%) and inhibition of in vitro fertilization of mouse oocytes by epididymal spermatozoa (26% and 62%), as compared to their respective pair-fed control values. Also observed were significant decreases in epididymal sperm content (72%, 6% diet only), total motile spermatozoa (85%, 6% diet only) and seminal vesicles epithelial cell height (13% and 29%). No abnormal semen parameters were observed after treatment with the 5% ethanol diet; however, in animals treated with the 6% diet, significant decreases were noted in coagulum weight (50%), sperm count (85%) and acid phosphatase content (53%). Improvement in all parameters was observed in the contralateral half of the reproductive tract subsequent to 10 weeks abstinence. Only germ cell desquamation remained significantly elevated (100% as compared to control) in animals that ingested the 5% diet. In contrast, significant abnormalities persisting 10 weeks after treatment with the 6% ethanol diet included increased germ cell desquamation (200%), inactive seminiferous tubules (157%) and sperm dysmorphology (39%) and decreased forward progression (17%) of epididymal sperm, as compared to values. These findings are discussed in relation to the influence of alcohol consumption on male reproductive function in man.

Animals↗
PubMed1984

Analysis of benzodiazepine binding sites in rat pituitary gland.

Benzodiazepine binding sites in rat pituitary gland were investigated by equilibrium binding assays in vitro. Using [3H]flunitrazepam [( 3H]FNM), specific binding was demonstrated in both anterior and neurointermediate lobes. Clonazepam and Ro 5-4864 were used to discriminate the binding to central and peripheral-type sites. Both types of binding site were found to be relatively concentrated in the neurointermediate lobe. Scatchard analysis demonstrated that Kd values for [3H]FNM for the two types of sites were similar to those reported in other areas.

Animals↗
PubMed1984

Cardiovascular findings in congenital contractural arachnodactyly: report of an affected kindred.

Three generations of a kindred had a history and physical findings consistent with congenital contractural arachnodactyly (CCA) segregating in an autosomal-dominant manner. Six of the seven affected patients we examined had mitral valve prolapse (MVP) diagnosed clinically or by echocardiography. The family members without CCA did not have MVP. This association of cardiac involvement with CCA further lessens the distinction between CCA and the Marfan syndrome. The indication for ophthamologic and echocardiographic follow-up of patients carrying the diagnosis of CCA is stressed.

Adult↗
PubMed1984

Central-type benzodiazepine binding sites in rat pituitary gland are of the BZ1 subtype.

Experiments were performed to investigate the subtype of central-type benzodiazepine binding site present in rat pituitary gland. Bmax values for [3H] n-propyl beta-carboline-3-carboxylate and [3H] flunitrazepam (for central-type binding only) were similar. Displacement of [3H] flunitrazepam by n-propyl beta-carboline-3-carboxylate gave a linear Hofstee plot and a Hill coefficient close to unity. These results suggest that the central benzodiazepine binding sites in the pituitary are predominantly of the BZ1 subtype, as found in the cerebellum.

Animals↗
PubMed1984

Comparison of human acrosin, a trypsin-like sperm proteinase, with human pancreatic trypsin: temperature stability and effect of cations.

Temperature and ion sensitivity of human acrosin (EC 3.4.21.10) was compared to that of human trypsin. With the exception of zinc, no ion tested had significant effects on either enzyme. Zinc behaved as a noncompetitive inhibitor of both enzymes, with inhibition constants of 1.8 and 1.7 mM for acrosin and trypsin respectively. Trypsin was inhibited by the chelators EDTA and EGTA, a specific effect reversed by either calcium or magnesium. EDTA inhibited acrosin in a nonspecific manner, while EGTA was without effect. Unlike acrosin from the other species, human acrosin was unaffected by calcium or the polyamines, spermine and spermidine. Acrosin was sensitive to inhibition by preincubation temperatures above 5 degrees C; trypsin, however, was stable to preincubation temperatures up to 60 degrees C. Hydrolysis of N-alpha-benzoyl-L-arginine ethyl ester was more efficiently catalyzed by trypsin (6800 cal/mol) than by acrosin (9511 cal/mol).

Acrosin↗
PubMed1984

A pattern of partially homologous recombination in mouse L cells.

Herpes simplex virus thymidine kinase gene and pBR322 DNA (in large excess to the thymidine kinase gene) were introduced into mouse L cells by calcium phosphate DNA-mediated gene transfer. DNA fragments encompassing six junctions between the exogenous DNAs have been cloned and their nucleotide sequences determined. Analysis of these sequences has shown that stretches of partial homology involving from 20-50 base pairs are present near the points at which joining occurs between the donor molecules. The structure of the junction sequences suggests that the recombination event involves the alignment of the two donor DNA molecules at partially homologous regions followed by staggered cutting and joining. One donor molecule is always cut in the region of partial homology, while the second is cut at some distance that is a small multiple of 13.5 +/- 0.5 base pairs away (at 0, 14, 27, 39, 41, and 54 base pairs). In the three junctions where the second cut is far from the region of homology, a 17- to 19-base-pair segment of DNA separates the donor sequences. In all cases the origin of this "filler" DNA appears to be oligonucleotides derived from pBR322.

Animals↗
PubMed1984

General practitioner's care of the elderly: studies of aspects of workload.

This paper reports trends in the volume and nature of general practitioners' contacts with the elderly patients on their NHS lists in Dundee during the 1970s. It forms part of a larger project involving 32 general practitioners collaborating in a continuing study concerning the introduction of the first health centre in Dundee.During the decade contacts with the elderly increased as a proportion of the general practitioners' total work, broadly commensurate with the increase in Dundee's elderly population. Indirect contacts, mainly reissue of prescriptions for longterm medication, showed a greater proportional increase than direct consultations. Home visiting of the elderly remained relatively constant, while house calls to other age groups declined. Hospital referrals remained a small proportion of the general practitioners' work. Entry into a health centre was not associated with obvious changes in patterns of workload.If more might be done in planning and implementing changes in care of the elderly at general practice level, such changes should be the result of consensus among the professionals concerned, and should take account of the views of recipients of care.

Aged↗
PubMed1984

A move to a health centre: the effect on home visiting, repeat prescribing and patients' choice of transport.

A group of general practitioners recorded data about their work before and after moving into a health centre. A group of doctors who did not enter the health centre made equivalent observations for comparison.Patients of the health centre doctors increased their use of public transport by 13 per cent; the ;no-entry' group of doctors did not record a similar increase. A 27 per cent reduction in home visits was thought to be a direct result of entry into the health centre, contributing factors being, in all probability, availability of public transport and the provision of a pharmacy. An increase in the issue of repeat prescriptions without consultation was considered to be evidence of a wider trend since this change was not confined to the health centre doctors.It was concluded that patients will attend a health centre if public transport is easily available and that this factor should be born in mind when planning health centres, especially in inner city areas.

Community Health Centers↗
PubMed1983

Chromium supplementation of human subjects: effects on glucose, insulin, and lipid variables.

Seventy-six normal, free-living subjects were given supplements of 200 micrograms chromium (Cr) in the form of chromic chloride or a placebo in a double-blind crossover study with 3-month experimental periods. Twenty of the 76 subjects had serum glucose concentrations greater than or equal to 100 mg/dL 90 minutes after a glucose challenge (1 g glucose per kilogram of body weight). Chromium supplementation significantly decreased (P less than 0.05) the 90-minute glucose concentration of these subjects from 135 +/- 9 to 116 +/- 11 mg/dL; fasting glucose concentrations also decreased significantly. The 90-minute serum glucose levels of the 35 subjects with glucose concentrations less than the fasting serum glucose level were increased significantly by Cr supplementation, from 71 +/- 1 to 81 +/- 4 mg/dL. Fasting and 90-minute serum glucose concentrations of the remaining subjects who displayed 90-minute glucose concentrations greater than fasting levels but less than 100 mg/dL were not affected by Cr supplementation. In this study, immunoreactive serum insulin concentration, body weight, lipids, and other selected clinical variables did not change significantly during Cr supplementation. These data demonstrate that Cr supplementation decreases the serum glucose levels of subjects with 90-minute glucose concentrations greater than or equal to 100 mg/dL following a glucose challenge, increases serum glucose levels of subjects with 90-minute glucose concentrations less than fasting levels, and has no effect on the serum glucose levels of subjects with 90-minute glucose values similar to but greater than fasting levels.

Adult↗
PubMed1983

Male reproductive tract sensitivity to ethanol: a critical overview.

While endocrinological effects of acute and chronic ethanol ingestion have been extensively reviewed, a survey of ethanol induced functional and physical perturbations of the male reproductive tract remains lacking. A brief overview of recent literature concerned with ethanol sensitivity of various components of the reproductive tract is presented. Clinical findings are reviewed as they relate to the possible pathogenesis of alcohol-related testicular atrophy. Currently available animal models for the study of ethanol-induced male reproductive failure are discussed. Attempts have been made to separate the contribution of ethanol per se from secondary factors, such as hepatic dysfunction and nutritional deficiency, to manifestations of male infertility. Studies directed toward elucidating the mechanism(s) by which ethanol exerts its inhibitory effect on testicular steroidogenesis are discussed. Finally, evidence suggesting an effect of ethanol on the functional integrity of other components of the reproductive tract is reviewed. It is concluded that ethanol is a male reproductive tract toxin. Future clinical studies of alcoholics afflicted with testicular atrophy, but having normal liver histology, will be of great value in efforts to identify the mechanisms by which chronic ethanol ingestion results in reproductive impairment. Similar benefits will be realized in laboratory experimentation, in which models are employed that describe ethanol-induced infertility, while minimizing nutritional factors and hepatic involvement, and control for the reproductive maturity of the organism.

Acetaldehyde↗
PubMed1983

Effects of chromium supplementation on urinary Cr excretion of human subjects and correlation of Cr excretion with selected clinical parameters.

Daily urinary chromium (Cr) excretion of 15 healthy free-living female subjects was 0.20 +/- 0.03 microgram (mean +/- SEM) and nearly identical for 27 male subjects, 0.17 +/- 0.02 microgram. Minimum Cr absorption calculated from urinary Cr excretion was about 0.4 percent. Increasing intake fivefold by Cr supplementation led to a nearly fivefold increase in Cr excretion suggesting that the extent of absorption of supplemental inorganic chromium was similar to that from normal dietary sources. Correlations between 24-hour Cr excretion and urine volume, age, total creatinine and body weight were not found. Urinary Cr concentration of samples obtained following a morning void correlated with creatinine and Cr concentration following a glucose challenge but not with serum glucose, insulin, lipid parameters, age or body weight. Similar results were obtained for urine samples obtained from subjects during Cr supplementation. These results suggest that urinary Cr excretion does not appear to be a meaningful indicator of Cr status but is a meaningful indicator of Cr intake and that the absorption of supplemental inorganic Cr was similar to that of Cr from normal dietary sources.

Adult↗
PubMed1983

Relationship between semen characteristics and fertility in electroejaculated mice.

Ejaculates were obtained from C57BL mice by applying two successive series of electrical stimuli which were delivered via a bipolar rectal probe. The ejaculates thus collected contained fertile spermatozoa as indicated by results from in-vitro fertilization. Once separated from the seminal plasma, ejaculated spermatozoa possessed the same in-vitro fertilization rate as epididymal sperm. Ejaculates were analysed for coagulum weight, ejaculate volume, sperm count, sperm motility, acid phosphatase content and fructose content. Significant differences were present between several of these values for fertile and infertile mice, and values were therefore empirically assigned to represent minimal amounts for 'normal' fertility (1.5 microliters ejaculate volume; 10.2 mg coagulum weight; 2.5 x 10(6) spermatozoa/ml; 2.3 x 10(3) motile spermatozoa/ejaculate). One half of the fertile animals had no deficiencies in any of the characteristics measured, whereas 97% of the infertile animals had at least one deficiency. No fertile male had more than 2 deficiencies. These data show that the characteristics of mouse semen obtained by the present method of electroejaculation are related to the fertility status of the animal.

Animals↗
PubMed1983

Chronic pain therapy with transcutaneous electrical nerve stimulation: predictive value of questionnaires.

A retrospective study of 200 chronic pain patients was conducted to determine whether preexisting physical or social factors influence treatment success with transcutaneous electrical nerve stimulation (TENS). Responses to 30 questions from a preadmission questionnaire were analyzed against short-term treatment success. Patients with pain of more than a year's duration, who had undergone multiple surgical operations for pain control, who used tranquilizers, or who were not working because of pain, demonstrated a generally lower rate of treatment success, although the differences were not statistically significant. Treatment success rate was significantly higher for retired patients than for those with blue-collar jobs or those who were unemployed. There was no association between treatment success rate and site, frequency, character or severity of pain, age, sex, use of narcotic analgesics, or the presence of financial compensation or litigation. The value of TENS for chronic pain remains largely empirical.

Adolescent↗
PubMed1983

Ethanol-induced male reproductive tract pathology as a function of ethanol dose and duration of exposure.

Chronic ethanol ingestion by the male results in several manifestations of reproductive dysfunction. However, little is known concerning 1) the level of ethanol or duration of ethanol exposure necessary to produce pathological changes in the male reproductive tract; or 2) mechanism(s) by which ethanol exerts its toxic effects. The purpose of the present study was to develop an animal model which describes ethanol-induced male reproductive failure and to define conditions of ethanol exposure which alter male reproductive tract function. Proven breeder male C57Bl/6J mice were maintained on either a 5% (v/v) ethanol liquid diet for periods of 5, 10 or 20 weeks or a 6% (v/v) ethanol diet for 5 weeks. Daily blood ethanol levels peaked at 125 to 200 and 268 mg/100 ml in animals consuming the 5 and 6% ethanol diets, respectively. Plasma testosterone levels were depressed throughout all treatments, an effect which appeared reversible. Plasma testosterone was poorly correlated (r = 0.28) with blood ethanol levels during treatment. After treatment, reproductive tract pathology included reduced testicular and accessory sex organ weights, decreased spermatogenesis, increased desquamation of immature germ cells into the seminiferous tubule lumina and increased frequency of inactive seminiferous tubules. Whereas minimal changes were noted after 5 weeks treatment with the 5% ethanol diet, deficiencies became increasingly evident after either longer exposure periods or treatment with 6% ethanol for the same period. None of the treatment regimens resulted in altered plasma levels of hepatic enzyme markers or in altered histological appearance. The data indicate that male reproductive function is sensitive to both ethanol dose and duration of exposure. The animal model described in the present study should have utility in the evaluation of putative mechanisms of ethanol-induced male reproductive dysfunction.

Alcoholism↗
PubMed1983

Ethanol-induced male infertility: impairment of spermatozoa.

Ethanol is generally regarded as a reproductive toxin. However, the mechanism(s) of ethanol-induced infertility remain poorly understood. As male fertility depends upon the ability of spermatozoa to fertilize ova, it was the purpose of the present study to examine the effects of chronic ethanol treatment on several parameters related to sperm fertility. Male C57Bl/6J mice of proven fertility were administered liquid diets as follows: 5% (v/v) ethanol for either 1) 5 weeks; 2) 10 weeks; 3) 20 weeks; or 4) 6% (v/v) ethanol for 5 weeks. After each treatment, epididymal spermatozoa were evaluated with respect to quantity, motility, morphology and the ability to fertilize. A biphasic effect on sperm content was noted: 5- and 10-week treatments with 5% ethanol increased content by 80 and 65%, respectively, whereas 20-week treatment with 5% ethanol and 5-week treatment with 6% ethanol decreased content by 52 and 71%, respectively. Although the proportion of motile spermatozoa was unaffected by ethanol, average forward progression velocity was reduced, the effect being dependent on ethanol dose and duration of exposure. Similarly, the frequency of abnormal spermatozoa was increased; 20-week treatment with 5% ethanol and 5-week treatment with 6% ethanol increased the frequency of sperm morphological anomalies by 50 and 40%, respectively. Fertility of spermatozoa was reduced as a function of ethanol dose and duration of exposure. The ability of sperm to fertilize mouse ova in vitro was reduced by 34% (P less than .02) and 62% (P less than .001) subsequent to 20-week treatment with 5% ethanol and 5-week treatment with 6% ethanol, respectively. An animal model has been developed which describes ethanol-induced male infertility. The degree of reproductive impairment varies with the amount of ethanol ingested, and the duration of ethanol exposure. The continuum of effects should make possible the evaluation of putative mechanisms of male sterility resulting from chronic ethanol consumption.

Alcoholism↗
PubMed1982

Hepatitis B virus infections in laboratory staff.

Auckland Hospital laboratory staff were tested on three occasions over a 9 month period for the presence of hepatitis B antigen (HBsAg) and antibody (anti-HBs). Over 20 percent of technical staff were seropositive for one of these markers of hepatitis B virus (HBV) infection, this proportion being significantly higher than that found in new blood donors or in staff from a laboratory not handling blood samples. Asymptomatic infection with the HBV virus, as assessed by seroconversion changes of HBsAg to anti-HBS status, was detected in some staff members. The number of staff positive for HBsAg or anti-HBS increased with both age and length of period of employment in laboratory work. The results indicate that subclinical HBV infections are occurring in laboratory staff and the present procedures in the care and handling of blood specimens may require review and improvement.

Age Factors↗