Biomedical subjects

S L Gray

Publications and source records attributed to S L Gray.

42 records · Page 3Linked to original sources

PubMedDate not supplied

Prenatal ethanol exposure fails to affect stimulus reactivity in the rat.

Three groups of male Long-Evans rats, that were the offspring of dams maintained throughout pregnancy on a liquid diet in which 35% of the calories were derived from ethanol, pair fed an isocaloric liquid diet that had maltose-dextrin substituted for the ethanol, or maintained on lab chow and water were used as subjects. All subjects were nursed by foster mothers maintained on lab chow and water throughout pregnancy and lactation. The groups were not found to differ on open field activity or number of approaches to four stimulus objects in an open field at 26-30 days of age, on spontaneous alternation at 50-55 days of age or on response to a novel alley at 55 days of age. It was concluded that in the rat, prenatal ethanol exposure does not result in demonstrable changes in responsivity to stimuli in rats tested after 26 days of age.

Aging↗

PubMedDate not supplied

The insulin-like growth factor (IGF) system and gonadotropin regulation: actions and interactions.

Insulin-like growth factors (IGF) are polypeptides that regulate growth, differentiation and survival in a multitude of cells and tissues. The IGF system consists of ligands, receptors, binding proteins and binding protein proteases. The influence of the IGF system on reproductive parameters, specifically gonadotropin release and interactions between the IGF system and other effectors of gonadotropin release will be examined in this review.

Amenorrhea↗

PubMedDate not supplied

Computer-assisted sperm motion analysis of bovine sperm treated with insulin-like growth factor I and II: implications as motility regulators and chemokinetic factors.

The effects of insulin-like growth factors (IGFs) I and II on motility of bovine sperm were examined using a computer-assisted sperm motion analyzer (CASA). The following kinematic parameters were examined: percentage of rapidly moving cells, straight-line velocity , curvilinear velocity, average path velocity, amplitude of lateral head displacement, and beat cross frequency. Sperm were treated with IGF-I (100 ng/mL) or IGF-II (250 ng/mL) and compared to sperm in modified Tyrodes' medium only (control) at 90, 180, and 360 min using CASA. Insulin-like growth factor I and II increased the percentage of rapidly moving cells, straight-line velocity, curvilinear velocity, average path velocity, amplitude of lateral head displacement, and beat cross frequency compared to the control treatment. These results indicate that IGFs may be involved in initiation and maintenance of bovine sperm motility.

Animals↗

PubMedDate not supplied

Prenatal ethanol exposure in rats does not alter maze exploration or impair visual discrimination with or without distracting stimuli.

The effects of in utero exposure to ethanol on maze exploration and visual discrimination and reversal with and without distracting tactile stimuli present were examined in rats. Three groups were compared on all measures. An ethanol treated group was the offspring of dams receiving a liquid diet throughout pregnancy with 35% of the calories supplied as ethanol. Subjects in a pair-fed group were the offspring of dams fed the same diet except that the caloric equivalent of maltose-dextrin was substituted for the ethanol. Subjects in a third group were the offspring of dams fed ad lib lab chow and water throughout pregnancy. All pups were nursed by foster mothers who received ad lib lab chow and water throughout pregnancy and nursing. Relative to the control groups, the ethanol treated group was not found to be significantly more active in the maze at 41-45 days of age or deficient in visual discrimination or reversal with or without the distracting stimuli present at 46-77 days of age. These results are consistent with many studies suggesting that behavioral deficits resulting from in utero ethanol exposure become less evident with age.

Animals↗

PubMedDate not supplied

Hyperresponsiveness to methylphenidate in rats following prenatal ethanol exposure.

Rats exposed in utero to ethanol are hyperresponsive to methylphenidate when tested as neonates or adults. Long-Evans rats were maintained on liquid diets containing either ethanol or maltose-dextrin (35% of total calories) or on lab chow and water throughout pregnancy. Male offspring, who were raised by foster mothers maintained on lab chow and water throughout pregnancy and lactation, were used in two experiments to examine the effects of methylphenidate on activity. In Experiment 1, a time-sampling procedure revealed that methylphenidate (0, 1, 2 & 4 mg/kg) increases the frequency of ambulation in young (26-38 day old) ethanol-treated offspring more than in control offspring. In Experiment 2, an open-field procedure revealed that methylphenidate (0, 2, 4, 6 & 8 mg/kg) produces greater increases in number of squares covered and the total duration of ambulation during 5-min tests in adult (100-184 day old) offspring treated prenatally with ethanol than in control offspring. Both studies revealed that the hyperactivation effect increases with increased doses of methylphenidate.

Animals↗

PubMedDate not supplied

Predictors of nutritional supplement use by the elderly.

We conducted a population survey to describe patterns and determine predictors of the use of nutritional supplements and single-ingredient vitamins and minerals among elderly living in five adjacent urban and rural counties in the Piedmont area of North Carolina. The stratified random sample consisted of 3939 black and white participants age 65 or older from the Duke Established Populations for Epidemiologic Studies of the Elderly. The use of nutritional supplements within the previous 2 weeks was determined during an in-home interview. Multivariate analyses, using weighted data adjusted for sampling design, were conducted to assess the association between nutritional supplement use and predisposing, need, and enabling factors. Nutritional supplement use was reported by 26.2% of participants and was more likely for those who were white women, were high school educated, were underweight, took prescription drugs, had five or more health visits in the previous year, and had supplemental health insurance. It was less likely for those with poor self-rated health. The majority (71.5%) of nutritional supplement users took at least one single-ingredient supplement. Use of such products was more likely in those who were white, born and raised in an urban area, and high school educated, and was less likely in those with impaired functional status. Nutritional supplement use is prevalent in community-dwelling elderly and is more commonly associated with demographic factors and access to health care than with need factors.

Aged↗