Changes in urinary androgen concentration indicate that male giant pandas (Ailuropoda melanoleuca) respond to impending female oestrus during and outside the typical spring breeding season.

Giant pandas have been described as mono-oestrus spring breeders, yet males exposed to aseasonal oestrous females in the autumn or winter exhibit breeding behaviours and interest in mating. In the present study, urinary androgens and sperm parameters were quantified for males exposed to females expressing oestrus during spring, autumn or winter to examine plasticity of reproductive seasonality in giant pandas. Monthly average androgen concentrations for two males exposed to females in either seasonal or aseasonal oestrus were greater (P<0.

Seasonal shifts in giant panda feeding behavior: relationships to bamboo plant part consumption.

The giant panda (Ailuropoda melanoleuca) is classified as a carnivore, yet subsists on a diet comprised almost exclusively of bamboo. Wild and captive giant pandas use highly selective foraging behaviors for processing and consuming bamboo. These behaviors are for the first time quantified in captive giant pandas over a 5-year period of time showing highly specific seasonal trends.

Bombesin affects mucosal immunity and gut-associated lymphoid tissue in intravenously fed mice.

Background: Our prior studies show that intravenous (IV) total parenteral nutrition (TPN) produces atrophy of the small intestine-related gut-associated lymphoid tissue and significant decreases in intestinal IgA levels, the major system of mucosal immunity. Others have noted increased small intestinal permeability, bacterial adherence and translocation, and decreased IgA levels in TPN-fed animals. Bombesin, a neuropeptide, may play a regulatory role in mucosal immunity.

Effects of parenteral and enteral nutrition on gut-associated lymphoid tissue.

Changes in mucosal defense have been implicated as important factors affecting infections complications in critically ill patients. To study the effects of nutrient administration on gut-associated lymphatic tissue (GALT), ICR mice were randomized to receive chow plus intravenous saline, intravenous feeding of a total parenteral nutrition (TPN) solution, or enteral feeding of the same TPN solution. In a second series of experiments, a more complex enteral diet (Nutren) was compared with chow feeding and enteral TPN.

cis-dominant regulation of CD4 and CD8 gene expression in rat/mouse T cell heterohybridomas.

To determine whether expression of CD4 and CD8 molecules on T cells is determined-solely by transacting regulators, we examined heterohybridomas derived from the fusion of a rat CD4+ T cell line and the CD4- CD8- mouse thymoma BW5147. The majority of hybrid offspring expressed rat CD4. However, a fraction of the cell lines obtained expressed not only rat CD4 but also various amounts of mouse CD4 and CD8 molecules from both species.