Control of feeding and sexual behaviors by neuropeptide Y: physiological implications

Recent evidence suggests that a variety of hypothalamic neuropeptides may mediate interneuronal communication to coordinate diverse neuroendocrine and behavioral functions. In this work, we describe the effects of neuropeptide Y (NPY) on feeding and sexual behaviors. We observed that central administration of bolus NPY stimulated a robust, dose-related feeding response in satiated male and female rats. Continuous NPY receptor activation also evoked dose-related, intermittent feeding in a manner normally observed during nocturnal feeding. It appears that the paraventricular nucleus in the hypothalamus may be the primary site of NPY action because the anticipated reciprocal changes in NPY concentrations, in response to food deprivation followed by ad libitum food intake, occurred only in this site. Additional findings revealed that NPY-induced feeding may follow either substantial reduction or complete restraint of an inhibitory influence on feeding mediated by alpha 2-adrenoreceptor systems in satiated rats. Further, NPY was found to suppress male and female sexual behaviors. The suppressive effects on sexual behavior were apparent prior to or at the time of the onset of feeding after NPY administration. These observations may provide a neurochemical basis for clinical and animal studies on disorders of feeding associated with diminished reproductive functions.     

Structure-function analysis of stimulation of food intake by neuropeptide Y: effects of receptor agonists.

Neuropeptide Y (NPY) is a potent natural orexigenic signal in the rat. In this study, we have compared the effects of several COOH-terminal fragments of NPY and NPY receptor agonists on cumulative food intake in male rats. Rats were implanted with permanent cannulae either into the third cerebroventricle or paraventricular nucleus (PVN). NPY1-36 and various COOH-terminal fragments of NPY, two agonist analogues [Leu31, Pro34]NPY and NPY 1-4-Aca (epsilon-amino-caproic acid)-25-36, were administered intracerebroventricularly (ICV) or directly into the PVN, and the cumulative 2-h food intake response was compared. We observed that peptides that were effective by ICV were also effective when administered into the PVN, but smaller amounts of the peptides were required after PVN injection to evoke an equivalent food intake response. Injection of NPY1-36 induced a dose-dependent increment in food intake. Surprisingly, deletion of NH2-terminal tyrosine residue did not adversely affect feeding behavior. In fact, NPY2-36 was consistently more effective than NPY1-36; the enhancement in feeding by NPY2-36 was dose-related and was higher than evoked by NPY1-36 at each dose tested. Further serial deletion of aminoacids at NH2-terminal resulted in complete loss of activity. In addition, NPY agonist analogue, NPY 1-4-Aca-25-36, failed to stimulate feeding. However, NPY Y1 receptor agonist, [Leu31, Pro34]NPY, but not Y2 receptor agonist, NPY13-36, stimulated feeding.(ABSTRACT TRUNCATED AT 250 WORDS)     

Specificity of the monoclonal anti-I antibody (Hy)

In previous work we found that a monoclonal cold hemagglutinin from patient Hy strongly bound antigens contained in stage IV breast cancer sera. To infer the chemical structure of the antigens expressed in the cancer sera, we studied the specificity of the antibody (Hy). The antibody (Hy) had I specificity, based on agglutination scores with adult and cord red blood cells. The binding of the antibody to synthetic and milk oligosaccharides was determined using a solid phase enzyme immunoassay (EIA). The anti-I antibody (Hy) strongly bound LacNAc0-Me, LacNAc1----6Gal, LacNAc1----6 (LacNAc1----3)Gal, LacNAc-1----6 alpha GalNAc, LacNAc1----3LacNAc, and LacNAc, 0.05, 0.06, 0.09, 0.22, 0.35 and 0.75 mM giving 50% inhibition, respectively. The anti-I antibody (Hy), similar to the anti-I antibody (Ma), strongly bound LacNAc1----6Gal, but it differed from the anti-I antibody (Ma) in its cross-reactivity with the i sequence. The anti-I antibody (Hy) showed similar reactivities as the hybridoma monoclonal antibodies M18 and M39 with LacNAc1----6Gal and with the i-active sequence. The EIA procedure is a useful alternative to either radioimmunoassay or immunoprecipitation method in the study of anti-I,i specificities.     

Hemostatic parameters in newborn--II. Sequential study during the first four weeks of life

A sequential study of kaolin cephalin clotting time (KCCT), prothrombin time (PT), thrombin time (TT), plasma fibrinogen and serum FDP was conducted during the first four weeks of life on term and preterm babies. A "physiological dip" of PT and TT was noted inappropriate for gestational age (AGA) babies both term and preterm; in case of KCCT, the dip was significant in term AGA babies only. At the end of four weeks, PT and TT had moderately improved in term babies but showed little improvement in preterm ones; KCCT reached almost an adult value in all babies except in preterm AGA and term LGA (large for gestational age) ones. Plasma fibrinogen showed no "physiological dip" and reached adult level in two to four weeks. Serum FDP levels were appreciably raised in preterm AGA babies only at birth and there too normalised by 72 h.     

Antibacterial photodynamic activity of photosensitizer-embedded alginate-pectin-carboxymethyl cellulose composite biopolymer films

Lasers in Medical Science - Antimicrobial photodynamic therapy (APDT) is a promising approach for treatment of wounds infected with antibiotic-resistant bacteria. In this approach, delivery of...     

A breast feeding education and promotion program: Effects on knowledge,attitudes, and support for breast feeding

This study was undertaken to determine the effects of a partner-support, incentive-baed educational program on breast feeding knowledge, attitudes and support and to examine the relationship between feeding intentions and feeding behavior among low-income women. Women who expressed a willingness to participate in the intervention were randomly assigned to intervention and usual breast feeding (control) groups. Sixty-eight primipara women, with expected due dates between May and December, 1992, volunteered to participate in the study. Of these, 34 were randomly assigned to each of the two groups. Approximately 81 percent of the women completed the study, leaving n=29 in the control group and n-26 in the intervention group. The intervention consisted of special incentives (prizes) for women and their partners to participate in several breast feeding education and promotion activities. Intervention group women and their partners experienced positive changes in breast feeding knowledge and attitudes. Furthermore, the intervention seemed to have influenced more women in the treatment group to breast feed despite their prenatal feeding intentions. In addition, the partners of intervention group women were perceived to be more supportive of, breast feeding than control group partners. These findings suggest that incentives, such as donated prizes, can be used to attract lower socioeconomic group women and their partners to breast feeding promotion interventions. Participation in such interventions can produce positive changes in breast feeding knowledge, attitudes, and support, and can have a dramatic effect in promoting breast feeding.This study was supported through contract no. 59-3198-1-050 from the Food and Nutrition Service, U.S. Department of Agriculture.     

Antileishmanial action of Tephrosia purpurea linn,extract and its fractions against experimental visceral leishmaniasis

Tephrosia purpurea (family: Fabaceae), which is used in traditional remedies for the treatment of febrile attacks, enlargement and obstruction of liver, spleen, and kidney, was found to have significant antileishmanial activity, and has been extensively fractionated to locate the abode of activity. A fraction (F062) obtained from N‐butanol extract of T. purpurea showed consistent antileishmanial activity at 50 mg/ kg × 5 days by oral route against Leishmania donovani infection in hamsters. Activity was further confirmed in a secondary model, i.e., Indian langur monkeys (Presbytis entellus). Thus, the fraction F062 from this plant possesses potential to produce significant antileishmanial activity by oral route without producing any toxic side effects. Drug. Dev. Res. 60:285–293, 2003. © 2003 Wiley‐Liss, Inc.