PubMed Health⌕ Search

Biomedical subjects

B Liang

Publications and source records attributed to B Liang.

102 records · Page 6Linked to original sources
PubMed1982

Cardiac beta-receptor variation in rat strains selectively bred for differences in susceptibility to stress.

The radioligand 3H-DHA was used to estimate the density and affinity of cardiac beta-receptors in rat strains selectively bred for differences in response to stress. Maudsley Reactive rats selected for heightened reactivity to stress had a greater density of beta-adrenergic binding in cardiac membranes than rats of two genetically distinct Maudsley Non-Reactive strains selected for decreased reactivity to stress, and compared with one of these Non-Reactive strains the MNR/Har, increased affinity for 3H-DHA. Together with previous findings the present results demonstrate a negative correlation between estimates of basal sympathetic activity on the on hand, and post-synaptic beta-receptors in heart on the other, that are consistent with the notion that these receptor alterations have occurred as a result of long-term differences in pre-synaptic release of transmitter. The Maudsley strains may, therefore, provide a useful model for the study of beta-adrenergic receptors as a physiological locus for regulation of end-target responsiveness to sympathetic stimulation.

Animals↗
PubMed1978

Central and peripheral norepinephrine concentrations in rat strains selectively bred for differences in response to stress: confirmation and extension.

Inbred rats from the Maudsley Reactive (MR) strain had lower concentrations of norepinephrine in hypothalamus, heart, and spleen, and lower total catecholamines in adrenal than inbred Maudsley Non-Reactive rats (MNRA line). In contrast, they had a higher concentration of telencephalic NE than MNRA rats. These results confirmed previous findings obtained on rats maintained by non-systematic breeding within the two lines. Comparisons were also made between MR and a second Maudsley Non-Reactive strain (MNR). Rats of the two Non-Reactive lines (MNRA, MNR) have been bred from the same foundation population and selected for the same behavioral characteristics, but have been genetically isolated from each other for many generations. It was found that MR rats showed differences from MNR rats in hypothalamic and peripheral (but not telencephalic) NE concentrations similar to those seen in MR/MNRA comparisons. Since rats of the two Non-Reactive lines differ appreciably from MR rats in open-field defecation (the criterion on which they were selected), their differences from MR rats in a neurochemical system involved in sympathetic function suggests that this system may be functionally related to well established behavioral and physiological differences between the lines.

Adrenal Glands↗
PubMed1977

Serum prolactin and hypothalamic dopamine in rat strains selectively bred for differences in susceptibility to stress.

Rat strains selectively bred for behavioral differences in susceptibility to mild stress exhibited differences in serum prolactin (Prl) and hypothalamic dopamine (DA). Male rats from the Maudsley Reactive (MR) strain had higher levels of serum Prl and hypothalamic DA than rats from the Maudsley Non-Reactive (MNRA) strain. MR rats also showed a greater percentage increase in serum Prl 1 h after blockade of catecholamine synthesis by administration of alpha-methylparatyrosine (alphaMpT). The correlation of basal serum Prl levels with individual susceptibility to stress constitutes further evidence that Prl may play a functional role in the organism's response to stress. Strain differences in hypothalamic DA function may play a role in the etiology of strain differences in serum Prl.

Animals↗
PubMedDate not supplied

Differential understanding of sexual abuse prevention concepts among preschoolers.

Most evaluations of sexual abuse prevention programs employ composite knowledge scores that may mask whether individual skills are differentially understood. The few studies examining separate skills have provided no statistical justification for doing so. This study attempted to validate empirically distinct prevention skills and whether children comprehend these skills in the order taught by prevention programs: RECOGNITION (of good and bad touch), SAY-NO (refuse the perpetrator), GO (leave the situation), TELL-WHO (find an adult), and TELL-WHAT (accurately disclose the abuse). Subjects were 117 preschoolers who were individually administered the "What If Situations Test" (WIST). Analyses confirmed that the WIST was composed of six skills. The hypothesized sequence of skills produced a high coefficient of reproducibility, but an even higher coefficient was obtained when three common sequence reversals were added to the existing logical sequences. We discuss explanations for these cognitive sequence reversals and applications of this information for teaching preschoolers prevention concepts.

Child↗
PubMedDate not supplied

The effect of alcohol consumption on nutritional status during murine AIDS.

As alcohol (ETOH) abusers and AIDS patients have nutritional disorders, the influence of chronic ETOH consumption (5% v/v for 10 weeks) on levels of immunomodulatory nutrients (vitamins A and E, Zn, and Cu) in the serum, liver, small intestine, spleen, and thymus was determined during murine AIDS. The hepatic levels of vitamins A and E and Zn in both normal and LP-BM5 retrovirus-infected female C56BL/6 mice fed ETOH were significantly reduced compared to controls, whereas the level of Cu in the liver was not affected. Intestinal levels of vitamin A and Cu were not affected by ETOH, whereas vitamin E and Zn were significantly reduced in both normal mice and those with AIDS fed ETOH. The splenic levels of vitamin A and Zn in the normal mice were significantly reduced by ETOH compared to controls, but vitamin E and Cu were not. All splenic levels of nutrients measured were reduced in ETOH-fed mice with AIDS. The levels of vitamins A and E, Zn, and Cu in the thymus in murine AIDS were also significantly affected by ETOH consumption. The serum levels of vitamins A and E in both normal mice and murine AIDS were significantly decreased by dietary ETOH. These data produced evidence that chronic ETOH can directly aggravate undernutrition initiated by retrovirus infection. Such ETOH-induced malnutrition in AIDS may be a cofactor, accelerating development of AIDS via immunosuppression secondary to nutritional deficiencies.

Animals↗
PubMedDate not supplied

Alcohol consumption alters cytokine release during murine AIDS.

Acquired immune deficiency syndrome (AIDS) is a clinical disorder caused by a human immunodeficiency virus (HIV), representing the end point in a progressive sequence of immunosuppressive changes. HIV, the key causative agent of AIDS, induces immunosuppression that render the body highly susceptible to opportunistic infections and neoplasm. However, the onset of clinical symptoms of AIDS (e.g., low CD4+ T cells count, opportunistic infections, and tumors) is quite variable among HIV+ individuals with a mean incubation times 3-10 years following seroconversion. Because of the deleterious effects of chronic alcohol (EtOH) consumption on cytokine release, immune response, host defense, nutritional status, and oxidative stress, it has been believed to be a possible cofactor that could enhance the host's susceptibility to HIV infection, and subsequently accelerate the development of AIDS. The purpose of this review is to present evidence of EtOH-induced cytokine dysregulation during murine AIDS. Our results done in murine AIDS indicate the EtOH consumption may accelerate the development of AIDS by disrupting cytokine production. These EtOH-induced abnormalities in cytokine release may promote a more rapid development of AIDS as a cofactor, which exacerbates the immune dysfunctions initiated by retrovirus infection.

Animals↗