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Biomedical subjects

M E Wilson

Publications and source records attributed to M E Wilson.

At least 361 records · Page 20Linked to original sources

Influence of estrogen-treated females on sexual behavior and male testosterone levels of a social group of rhesus monkeys during the nonbreeding season.

The effect of the sequential estradiol benzoate treatment of each of 6 ovariectomized (OVX) females on a social group of rhesus monkeys was examined during the period from May to August. The group was housed outdoors and was composed of 7 adult males and 5 intact females, in addition to the 6 OVX animals. Social behavior was observed and male testosterone levels were monitored before, during and after estrogen treatment of the OVX females. Behavior of an unmanipulated group was also examined, and no sexual behavior occurred in this control group from May through August. In contrast, the sexual behavior of both males and gonadally intact females of the experimental group increased when estrogen-treated females were present. Sexual behavior remained elevated after the estrogen-treated females had been removed and continued so into the breeding season. The sexual behavior of the untreated females was displayed in cycles about 26 days in length. Male testosterone levels increased to values typical of the breeding season. Aggressive and submissive behavior also increased during the treatment. These results confirm previous findings about the influence of estrogen-treated females on male sexual behavior, and present the first direct evidence of increased testosterone levels in this situation. In addition, the data suggest that the presence of estrogen-treated females can induce sexual behavior in the other females of the same social group.

Agonistic Behavior↗

Evidence for different requirements in physical state for the interaction of lipopolysaccharides with the classical and alternative pathways of complement.

The influence of the state of aggregation of lipopolysaccharides upon their ability to interact with serum complement via either the classical or alternative pathway was studied. The anticomplement properties of two chromatographically distinct fractions of a phenol-extracted lipopolysaccharide isolated from Serratia marcescens were assessed by means of the standard sheep erythrocyte hemolytic assay and an alternative pathway-selective kinetic assay using rabbit erythrocytes. Both the high molecular weight PI fraction and the lower molecular weight PII fraction exerted anti-complement activity as determined in the sheep erythrocyte assay. Conversion of fractions PI and PII to their more soluble triethylamine salt forms resulted in a decrease in sedimentation coefficients and a corresponding loss of anticomplement activity. Further, the anticomplement activity of fractions PI and PII in the sheep erythrocyte assay was inhibited by polymyxin B, indicating a role for the lipid A region. Unlike the PII fraction, only the PI fraction can activate serum complement via the alternative pathway. This activity is not inhibited by polymyxin B, indicating that the response is not lipid A-mediated. Significantly, solubilization of the PI fraction with triethylamine had no effect on its ability to activate the alternative pathway. These studies clearly demonstrate that the interaction between lipopolysaccharides and serum complement is influenced by the state of lipopolysaccharide aggregation. However, this appears to be the case for lipopolysaccharide activation of the classical pathway but not of the alternative pathway.

Adult↗

Reproductive performance in capture-acclimated female rhesus monkeys (Macaca mulatta).

Behavioral and physiological data were collected over a three-year period on a colony of compound-housed rhesus monkeys (Macaca mulatta) to examine endocrine influences on sexual behavior. The reproductive performance of the experimental animals was compared to controls which were not routinely handled. The groups did not differ significantly with regard to the percentage of conceptions or other parameters of reproductive biology. The demonstration that manipulations attendant to data collection did not jeopardize reproductive success has important implications for research on primate colonies which are maintained primarily for breeding purposes. Additionally, female copulatory behavior was found to be a reliable indicator of ovulation which allows for an accurate prediction of the parturition date.

Acclimatization↗

A survey of anaesthetic misadventures.

Reports of anaesthetic misadventures were regularly collected in the Anaesthetic Department of a district general hospital, to identify recurring problems. Eighty-one misadventures, none of which had serious outcome, were reported during a 6-month period, in which 8312 anaesthetics were administered. Human error was more frequently responsible than equipment failure, and failure to perform a normal check was the factor most frequently associated. Local hazard warnings were circulated when necessary to members of the Department, and the reports formed the basis of departmental discussion and teaching.

Accidents↗

Emergence of gentamicin- and methicillin-resistant Staphylococcus aureus strains in New York City hospitals.

Gentamicin- and methicillin-resistant strains of Staphylococcus aureus have been isolated from Spring 1979 to the present from many hospitals in New York City. A large proportion of the strains were resistant to the majority of antistaphylococcal antibiotics. The ratio of multiply resistant strains was highest among tetracycline-resistant strains. There were significant differences in phage susceptibility patterns and the resistance spectrum of strains isolated at different hospitals, whereas strains isolated at the same hospital often showed a marked degree of similarity. This suggests multiple origins of gentamicin- and methicillin-resistant strains isolated in New York City.

Bacteriophage Typing↗

Isolation of N. meningitidis from patients in a gonorrhea screen program: a four-year survey in New York City.

In the course of the screening program for gonorrhea in New York City, a total of 964 N. meningitidis strains were recovered from the genitourinary tract and/or anal canal over a four-year period (April 1975-April 1979), the rate of such recoveries having tripled during that time. The majority of strains were isolated from anal canal cultures of male patients most of whom were seen in a clinic treating homosexuals. N. meningitidis and N. gonorrhoeae were cultured together from 41 patients: in 24 cases from different sites and in 17 instances from the same specimen. Evidence of clinically significant N. meningitidis involvement of genitourinary sites was obtained in a number of cases of urethritis and proctitis as well as in three instances of epidemiologically linked cases. The rising frequency of N. meningitidis isolations from these sites, with its potential clinical implications, should alert microbiologists, clinicians, and epidemiologists to the need for careful distinction of meningococcal from gonorrheal infection, particularly among homosexual men.

Female↗

Progesterone and estrogen concentrations in gilts with delayed parturition.

Twelve pregnant gilts were assigned to three treatments (four gilts per treatment): (1) corn oil (control) injected subcutaneously four times daily from day 110 of gestation until onset of lactation; (2) 25 mg progesterone (P4) injected subcutaneously four times daily from day 110 of gestation through day 113, or (3) 25 mg P4 injected subcutaneously from day 110 through day 115 of gestation. Excluding one gilt on treatment 2 which farrowed on day 110, average lengths of gestation for control gilts and gilts receiving treatments 2 and 3 were 113.3 +/- 1.2 (SE), 115.6 +/- .7 and 118.0 +/- .4 days. Associated mean percentages of live births were 87.4 +/- 5.9, 48.8 +/- 24.4 and 2.5 +/- 2.5, respectively. P4 averaged 2.9 +/- .6 ng/ml in blood serum of control gilts during the 24 hr preceding parturition. P4 was released in a sporadic pattern by gilts on treatment 3, resulting in higher P4 concentrations (9.0 +/- 1.7 ng/ml) for the same prepartum period. Concentrations of P4 in serum of gilts on treatment 2 averaged 7.6 +/- 1.6 ng/ml, intermediate to, but not different from, concentrations of P4 in controls and gilts on treatment 3. Concentrations of estrogen in serum of control gilts averaged 6.2 +/- 1.3 ng/ml during the 24 hr preceding parturition, whereas concentrations of estrogen in gilts treated with P4 were reduced (P less than .01) to below 2 ng/ml during the same prepartum period. The erratic pattern of concentration of P4 during and after administration of exogenous P4 may reflect a disturbance of the secretion or metabolism of endogenous P4. We suggest that failure to suppress P4 post-treatment plus reduced estrogenic stimulation impedes the birth process and contributes to the high incidence of stillbirths observed in gilts with progestin-delayed parturition.

Animals↗