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Biomedical subjects

J Broida

Publications and source records attributed to J Broida.

At least 19 recordsLinked to original sources

An investigation of coaches' perceptions of the causes of home advantage.

This study investigated the personal experiences of 144 high school coaches in terms of their perceptions of the causes of the home advantage. Surveys were distributed to varsity coaches of local high school sports asking them to assign a percentage value to each of the most common explanations of -the home advantage, reflecting the perceived importance of each, e.g., social support, travel or fatigue, site familiarity, officials' bias, and self-fulfilling prophecy. A 3 x 6 repeated-measures analysis of variance indicated that no differences were significant in attribution of the causes of home advantage for the combinations of sex of coach and sex of athlete. A significant difference was noted in the percentages assigned across the five explanations provided the coaches. Post hoc comparison indicated that site familiarity was seen as the most important explanation across the combinations of the sex of coach and sex of athlete.

Attitude↗

Continued validation of the Multidimensional Perfectionism Scale.

Scores on the Multidimensional Perfectionism Scale have been correlated with measures of obsessive-compulsive tendencies for women, so the validity of scores on this scale for 41 men was examined. Scores on the Perfectionism Scale were significantly correlated (.47-.03) with scores on the Maudsley Obsessive-Compulsive Inventory.

Adult↗

Further validation of the Indecisiveness Scale.

Scores on the Indecisiveness Scale have been shown to be correlated with scores on measures of obsessive-compulsive tendencies and perfectionism for women. This study examined the validity of the Indecisiveness Scale with 41 men whose mean age was 21.1 yr. Indecisiveness scores were significantly correlated with scores on measures of obsessive-compulsive tendencies and perfectionism. Also, undeclared majors had a significantly higher mean on the Indecisiveness Scale than did declared majors.

Adult↗

Prior intrauterine position influences body weight in male and female mice.

In two longitudinal studies, intrauterine location of male and female Rockland-Swiss mice relative to fetuses of the same and opposite sex dramatically influenced body weight. In one study, body weight of males and females that were located in utero between two female fetuses (OM animals) or between two male fetuses (2M animals) was assessed from birth to the time of weaning (25 days of age). The body weights of 2M females were indistinguishable from those of OM and 2M males on all but a few of the 25 postnatal days of life. Also, 2M females were significantly heavier than OM females from Postnatal Day 6 onward, and 2M males weighed significantly more than OM males from Postnatal Day 19 onward. In a second study, food intake and body weight of animals from different intrauterine locations were examined from 25 to 120 days of age. Regardless of prior intrauterine position, males were always heavier than females. However, prior in utero location modulated body weight in that 2M females were significantly heavier than OM females and 2M males were reliably heavier than OM males. Intrauterine position effects were observed in the absence of any appreciable influence of this variable on levels of food intake. Taken together, the results suggest that prior in utero location may influence metabolic set points involved in the regulation of body weight and fat storage.

Age Factors↗

Socio-medical determinants of hospital utilization in Quebec, Canada, 1970-1975.

The relationship between ambulatory physician use and hospitalization was studied using aggregate data in the Province of Quebec, Canada. The analysis showed that the introduction of health insurance covering physician services had a negligible influence on hospitalization. The average length of short-term hospital stays was determined by the proportion of aged population, the proportion of English speaking persons, and the prior level of hospitalization in the medical market areas. Overall, hospital discharge rates remained very constant during the period of six years (1970-1975). There were, however, reductions in hospitalization for infectious diseases, diseases of the blood and blood-forming organs, respiratory diseases, and diseases of the skin and subcutaneous tissue, and increases in the hospitalization rates for neoplasms, circulatory system disorders, musculoskeletal conditions, congenital anomalies, and perinatal morbidity and mortality.

Adult↗

Sequence organization and control of transcription in the bacteriophage T4 tRNA region.

Bacteriophage T4 contains genes for eight transfer RNAs and two stable RNAs of unknown function. These are found in two clusters at 70 X 10(3) base-pairs on the T4 genetic map. To understand the control of transcription in this region we have completed the sequencing of 5000 base-pairs in this region. The sequence contains a part of gene 3, gene 1, gene 57, internal protein I, the tRNA genes and five open reading frames which most likely code for heretofore unidentified proteins. We have used subclones of the region to investigate the kinetics of transcription in vivo. The results show that transcription in this region consists of overlapping early, middle and late transcripts. Transcription is directed from two early promoters, one or two middle promoters and perhaps two late promoters. This region contains all of the features that are seen in T4 transcription and as such is a good place to study the phenomenon in more detail.

Amino Acid Sequence↗

Sex differences in the activity of mice: modulation by postnatal gonadal hormones.

A series of six experiments was performed to examine the influence of postnatal-gonadal-hormone exposure on home-cage activity in Rockland-Swiss albino mice. Intact females were more active than their male counterparts and gonadectomy in adulthood, while reducing levels of the behavior in both sexes, did not eliminate the gender difference. Males that were castrated on the day of birth were more active than animals castrated 5, 10, or 25 days later. Also, females treated with testosterone propionate on the day of birth were less active than oil-treated controls and females exposed to the steroid 10 days after birth. Thus, perinatal exposure to gonadal hormones suppresses adult levels of home-cage activity in mice.

Animals↗

Infanticide: accounting for genetic variation in mice.

Infanticide, the killing of young, is one of a number of sexually-dimorphic traits in mice that is dependent upon androgen stimulation during perinatal life and during adulthood. Genotype also influences infanticide in that males of some strains of mice (C57BL/6J) exhibit high levels of this behavior while males of other strains (DBA/2J) seldom kill young. The experiments conducted here show that strain differences in pup killing behavior exhibited by males are not related to postweaning social factors nor are they due to differences in perinatal, pubertal, or adult levels of circulating hormones. These results, in combination with those previously reported, suggest that strain differences in the tendency of mice to kill young may instead depend upon the interaction of genotypic features such as prenatal hormone titers and/or sensitivity to these hormones, as well as on extra organismic factors such as intrauterine position. A model for understanding the manner in which genes and hormones may interact to influence infanticide and other hormone dependent sexually-dimorphic behaviors in mice is presented.

Aggression↗

Acute endocrine correlates of attack by lactating females in male mice: effects on plasma prolactin, luteinizing hormone and corticosterone levels.

Immediately following defeat inflicted by lactating Rockland-Swiss (R-S) albino mice, adult R-S male mice exhibited significant reductions in circulating prolactin (PRL) and luteinizing hormone (LH), but not corticosterone (CORT). These results suggest that acute neuroendocrine responses to intersex competition may be as dramatic as those previously reported for intermale encounters.

Aggression↗

Genotype modulates testosterone-dependent activity and reactivity in male mice.

Adult castration significantly reduced the homecage locomotor activity of both inbred C57BL/6J and DBA/2J and outbred Rockland-Swiss (R-S) male mice. Castrated C57BL animals exhibited greater reductions in this behavior than did the other genotypes. Locomotor activity in a novel environment (reactivity) was also reduced by castration but only for inbred males. In both test situations, postcastration reductions in ambulation were prevented by implants of testosterone (T)-containing Silastic capsules. Thus, testicular hormones promote activity and reactivity in the male mouse in a genotype-dependent fashion.

Animals↗

Infanticide exhibited by female mice: genetic, developmental and hormonal influences.

Approximately 25-40% of 25-45 day old C57BL/6J females killed young (1-3 day old Rockland-Swiss (R-S) albino mouse pups) while similarly aged DBA/2J females were parental or ignored neonates. Beyond 45 days of age C57BL and DBA females seldom killed young. When ovariectomized at weaning and tested for infanticide at 65 days of age, DBA females rarely killed neonates while 40% of C57BL females exhibited the behavior. In contrast to DBA females, significantly more C57BL females killed young in response to the adult administration of testosterone propionate (TP) and estradiol benzoate (EB), but not dihydrotestosterone propionate (DHTP). It is tentatively proposed that strain differences in spontaneous and steroid aroused infanticide in female mice may be related to differences in the prenatal hormone environment.

Animals↗

Intermale aggression and infanticide in aged C57BL/6J male mice: behavioral deficits are not related to serum testosterone (T) levels and are not recovered by supplemental T.

Healthy aged adult (24-26 months of age) and young adult (2-4 months of age) c57BL/6J male mice were assessed for intermale aggression, pup-killing behavior (infanticide), and circulating levels of testosterone (T). When compared to young adult male mice, aged adult males were highly variable in the exhibition of both androgen-dependent behaviors. Significant numbers of aged males exhibited deficits in aggression and pup-killing while other animals were as behaviorally active as their young male counterparts. Assessment of serum T showed that aging did not produce a reduction in levels of the steroid and individual variability in androgen-dependent behavior of aged males was not related to plasma levels of the hormone. When aged non-aggressive and non-killer males were exposed to supplemental T by way of subcutaneously implanted silastic capsules, circulating levels of the steroid were elevated but T-dependent behavior was not recovered. These findings, in combination with those previously reported for copulatory behavior, indicate that the deficits observed in the androgen-dependent behavior of aged male mice cannot be attributed to a breakdown in the production of testicular androgens. While neural refractoriness to T may account in part for deficits in androgen-dependent behavior of aged males, the variability that is observed in the reproductive behaviors of aged male rodents ultimately may be related to other sources of variation such as the perinatal environment.

Aggression↗

Mice: progesterone and the regulation of strain differences in pregnancy-induced nest building.

Pregnant DBA/2J females built significantly larger and more completely enclosed nests than did pregnant C57BL/6J mice. This strain difference was restricted to the last half of gestation and was not observed during either the virgin state or lactation. Genotype-based differences in pregnancy-induced nest building were not related to circulating levels of progesterone (P), core temperature, or body weight. Exposure to supplemented P during pregnancy elevated nest building exhibited by pregnant C57BL females but did not induce DBA-like levels of the behavior. Also, virgin DBA females built larger nests in response to P than did C57BL females. These findings suggest that differences in the sensitivity of central neural tissue to steroid hormones may account for genotypically determined variation in patterns of pregnancy-induced nest building.

Animals↗

Genotypic influences on infanticide in mice: environmental, situational and experiential determinants.

Approximately 20-30% of adult, 60-70 day old, dBA/2J male mice exhibit infanticide toward standard stimulus 1-3 day old Rockland-Swiss Albino mouse pups, while 50-80% of adult C57BL/6J males display the behavior. Reciprocally-crossed hybrid males exhibit DBA-like levels of low pup-killing behavior and cross-fostered DBA and C57BL males retain their strain-typical phenotype. Also DBA males continue to exhibit low levels of infanticide and C57bL males display high levels of the behavior regardless of the length of pup exposure, or the sex, age, or strain of the stimulus newborn. Thus, strain differences in pup-killing behavior are not related to differences in the prenatal or postnatal maternal environment, or to situational or experiential factors. Inherent biological differences may be responsible for the strain differences in infanticidal behavior.

Animals↗

Strain-typical patterns of pregnancy-induced nestbuilding in mice: maternal and experiential influences.

Pregnant C57BL/6J mice incorporate less material into maternal nests and build fewer fully enclosed nests than do pregnant DBA/2J mice. These strain differences are not ameliorated by additional reproductive experience since multiparous animals also exhibit a similar pattern. Reciprocally-crossed hybrid females exhibit DBA-like levels of pregnancy-induced nestbuilding and cross-fostered C57BL and DBA females retain the phenotype of their strain. Experiential and maternal environmental factors apparently are not responsible for strain differences in pregnancy-induced nestbuilding. Differences in ovarian function and/or central neural tissue sensitivity to ovarian hormones may modulate strain differences in pregnancy-induced nestbuilding.

Animals↗