Biomedical subjects

S Meade

Publications and source records attributed to S Meade.

4 recordsLinked to original sources

PubMed2001

Feeding, drinking, and temperature responses of chickens to intracerebroventricular histamine.

The present study examines the effects of intracerebroventricular injections of histamine (HA) and two HA antagonists, the H(1) receptor antagonist chloropheneramine maleate (CM) and the H(2) receptor antagonist cimetidine (CIM), on food and water consumption and body temperature in chickens. Single-Comb White Leghorns (SCWL) and broiler cockerels were utilized for these experiments. The first pair of experiments consisted of intracerebroventricular injections of HA and its effects on food and water consumption. HA was infused at dosages of 0, 25, 50, and 100 microg/10 microl of artificial cerebrospinal fluid (aCSF). HA significantly decreased food and water intake in a dose-dependent manner. The second pair of experiments examined the effects of HA on water intake while birds had no access to feed. Water intake was not significantly affected by intracerebroventricular injections of HA. The next pair of experiments examined the effects of HA on body temperature. In SCWL, body temperature was not affected by HA until 165 min postinjection when HA decreased temperature in a quadratic dose-response with maximum hypothermia being achieved at a dose of 25 microg. In contrast, HA increased body temperature in broilers beginning at 75 min postinjection. In the final series of experiments, the anorexia induced by HA was attenuated in SCWL and broilers with pretreatment of either CM or CIM. These results suggest that HA has an anorexigenic effect in SCWL and broiler cockerels, and this effect is mediated by both H(1) and H(2) receptors. Water intake is not directly affected by the intracerebroventricular injection of HA. Whereas HA increased body temperature in broilers, the response in SCWL is equivocal.

Animals↗

PubMed2000

Leptin-induced decrease in food intake in chickens.

The effect of intracerebroventricular (i.c.v.) injection of leptin was investigated using broiler and Single Comb White Leghorn (SCWL)-type chickens. These represent relatively fast- and slow-growing birds, respectively. The i.c.v. injection of leptin decreased food intake in both broilers and Leghorns in a dose-dependent manner. The most efficacious dose appeared to be 10 microg in both types of chickens. Water intake was generally not affected by leptin, indicating that this effect was not due to general malaise. It appears that leptin can act within the central nervous sytstem of birds to decrease food intake.

Aging↗

PubMed1991

Breast-feeding patterns of Montserratian women.

This article describes the breast-feeding patterns found on Montserrat by a survey that interviewed 69 mothers who delivered infants over a 13-month period, from March 1989 through March 1990. The results indicated that 94% of the women breast-fed these children for at least two weeks after delivery; that 70% were still breast-feeding at the time of the interview in March or April 1990; and that principal factors influencing early termination of breast-feeding were the age at which supplementary feeding was commenced and lack of maternal information about why babies appear to reject the breast.

Age Factors↗

PubMed1988

Enhanced transforming activity of pSV2 plasmids in human cells depends upon the type of damage introduced into the plasmid.

When pSV2-gpt or pSV2-neo plasmids are introduced into human cells by calcium phosphate coprecipitation, the yield of stable transformants (Gpt+ or Neo+) is increased by irradiating the respective plasmid DNA in vitro with UV (254 nm). To identify specific lesions that can increase the transforming activity of plasmids in human cells we examined pSV2 plasmids containing different types of damage. Of the lesions tested, cyclobutane pyrimidine dimers produced the greatest increase, and can nearly fully account for the effect of 254 nm UV on transformation. The enhancement of transformation produced by UV was not altered by the additional treatment of the plasmid DNA with T4 endonuclease V, an enzyme that nicks DNA specifically at pyrimidine dimers. Treatment of plasmid DNA with osmium tetroxide to produce thymine glycols, or with acid and heat to produce apurinic sites did not affect transformation frequency. The enhancement occurred in all the human cell lines tested, whether they contained or not sequences homologous to those in the plasmids, and was independent of the repair capacity of the recipient cells.

Cell Line↗