Insatiable feeding evoked in rats by recurrent perfusion of neuropeptide Y in the hypothalamus

Hyperphagic-like intake of food was determined in the unrestrained rat during the sustained elevation over time of neuropeptide Y (NPY) within the paraventricular nucleus (PVN) and surrounding hypothalamic regions. A single guide tube was implanted stereotaxically in each of 22 rats for localized, intermittent perfusions of a CSF vehicle, nondeprotected NPY(1-36) or native NPY. Each site in the PVN of the fully sated rat was perfused repeatedly over a 5.0-h interval by means of a standard push-pull cannula system at a rate of 20 microliters/min for 6.0 min in one of three concentrations: 0.2, 1.0 and 2.0 micrograms/min. Two perfusions of 1.0 micrograms/min NPY evoked an intake of 4.6 +/- 1.1 g of food over a 3.0-h period, whereas 4-7 and 8-15 perfusions of this concentration of NPY, distributed over 5.0 h, induced the sated rats to eat a total of 12.0 +/- 1.1 g and 33.2 +/- 3.0 g, respectively. During a fixed number of 10 hypothalamic perfusions distributed over 5.0 h, concentrations of 0.2 and 2.0 micrograms/min NPY caused a cumulative intake of food in the rats of 14.2 +/- 2.0 g and 31.7 +/- 3.3 g, respectively. Under each condition, parallel push-pull perfusions of either control solution in the same hypothalamic sites were without effect on feeding. During the 5.0-h interval of repeated perfusions, successive bouts of eating occurred with individual intakes of food reaching as high as 49.0 g, which exceeded by up to two-fold the entire daily consumption of food. However, ingestion of water was unaffected by perfusion of NPY.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of dietary selenium supplementation on parasitemia,anemia and serum proteins of Trypanosoma brucei brucei infected rats

Trypanosomosis has been associated with immunosuppression, anemia and oxidative damage while selenium possesses both immunostimulatory and antioxidative effects. This study was designed to assess the effect of dietary selenium supplementation on parasitemia, anemia, survival pattern and serum protein profiles of trypanosome-infected rats. Twenty five rats, divided into five groups (A–E) of 5 each, were treated as follows: 4, 8 and 16 ppm (ppm) of selenium in their feed, respectively throughout the experimental period and were infected with Trypanosoma brucei brucei on day 14 post supplementation, infected not supplemented and the negative control. Supplementation at 4 and 8 ppm increased the packed cell volume (PCV) and hemoglobin (Hb) concentration on day 7 of supplementation (PS) when compared with the unsupplemented groups. Following infection on day 14 PS, the PCV, Hb of 16 ppm and infected not supplemented groups were significantly (P < 0.05) lower than other groups on days 28 and 35 PS. Supplementation did not lead to significant (P > 0.05) changes on the total protein, albumin and globulin by day 14 PS. Infection, however, caused significant (P > 0.05) decrease in the total protein and albumin from day 28. The supplementation did not significantly (P > 0.05) increase the pre-patent period but caused a significant reduction in the parasitemia levels and increased survival intervals. Dietary selenium supplementation, from the results, may show promise in the management of African trypanosomosis as the supplementation was able to: reduce anemia and parasitemia and increase survival intervals of trypanosome infected rats.     

Comparison of intradiurnal variation of airborne pollen in Mar del Plata (Argentina). Part I. Non-arboreal pollen

Intradiurnal variation of non-arboreal pollen (NAP) aredescribed in relation to the associated weather using the data obtainedwith a Burkard trap in Mar del Plata city, for a three year data set(1988, 1992 and 1995). The daily pattern of concentration was quitehomogeneous during the years analysed except for 1995, when it showed avariation due to the change of position of the station. Qualitativecomposition of the NAP airborne pollen was mainly represented byPoaceae, Plantago and Cyperaceae during the three years. The daily trendshowed high concentrations during daylight hours, when instability andconvective movements prevail, and low concentrations in the night, whenmeteorological conditions favour the development of a stable stratifiedlayer.     

A Pilot of a Video Game (DDR) to Promote Physical Activity and Decrease Sedentary Screen Time

Objective: We examined the feasibility of Dance Dance Revolution (DDR), a dance video game, in participants' homes, to increase physical activity (PA) and to decrease sedentary screen time (SST). Methods And Procedures: Sixty children (7.5 ± 0.5 years) were randomized in a 2:1 ratio to DDR or to wait‐list control (10‐week delay). DDR use was logged, PA was measured objectively by accelerometry. SST was self‐reported at weeks 0 and 10. At week 28, after both groups had access to DDR, accelerometry and SST were repeated. Results: Mean use of DDR was 89 ± 82 (range 0–660min) min per week (mpw). The DDR group showed increased vigorous PA and a reduction in light PA; the control group showed no increase in moderate and/or vigorous PA (MVPA) although they also had a reduction in light PA. Differences between the groups were not observed. The DDR group also reported a decrease in SST of ?1.2 ± 3.7 h per week (hpw) (P < 0.05), whereas the controls reported an increase of +3.0 ± 7.7 hpw (nonsignificant). The difference in SST between the groups was significant, with less SST in the DDR group. Between weeks 10 and 28, numeric reductions in SST were reported in both groups. In the DDR group, SST at week 28 (8.8 ± 6.0 hpw) was lower than baseline (10.5 ± 5.5 hpw; P < 0.03). Discussion: This pilot study suggests that DDR reduces SST and may facilitate slight increases in vigorous PA. Further study is needed to better characterize children and contexts in which DDR may promote a healthy lifestyle.     

Emergency Contraceptives and the Beginning of Human Animals

Emergency contraceptives may sometimes prevent implantation, thereby causing the death of the embryo. According to some positions contrary to abortion, because the embryo is a human animal, there are usually decisive moral reasons not to use them. In this article, I will show that objecting to the use of emergency contraceptives on those grounds is unjustified. If organisms are real existents, then according to the most plausible conception of what is required for a group of cells to compose one, the embryo cannot qualify as a single organism. On the other hand, if organisms are virtual objects, then whether or not the embryo qualifies as one is morally irrelevant. I conclude that even if those positions are right about the morality of abortion, they are not entitled to oppose the use of emergency contraceptives.