T cells affect thymic involution during puberty by inducing regression of the adrenal reticularis.

The thymus involutes after puberty, although the mechanism by which this process occurs remains poorly understood. The profile of thymic involution, which is inversely correlated with an increase in peripheral T cells, may indicate that the accumulation of T cells in the periphery is related to thymic atrophy. In this study, it was shown that the prevention of T cell generation delayed the initiation of thymic involution.

Adrenal participation in thymocyte death by anti-CD3 antibodies in vivo.

The deletion of CD4- and CD8-double-positive (DP) cells in the thymus after treatment with anti-CD3 antibodies has long been considered as a useful model for clonal deletion during T cell development, although it was reported that DP cell death was not observed in neonates where self-tolerance should be developing. We dealt with the cellular basis of this enigmatic phenomenon in this report. Due to the similar susceptibility to the antibody-treatment in vitro between neonatal and adult thymocytes, critical factors may be outside rather than within the thymus.

Effects of a high-protein diet versus dietary supplementation with ammonium chloride on struvite crystal formation in urine of clinically normal cats.

Objective: To evaluate the effects of a high-protein diet versus dietary supplementation with ammonium chloride (NH4Cl) on struvite crystal formation in the urine of clinically normal cats by measuring the urine concentration of hydrochloric acid (HCl)-insoluble sediment, urine pH, struvite activity product (SAP), number of struvite crystals in urine, and urine volume.

Animals: 23 healthy adult cats.

Procedure: Urine was fractionated by centrifugation with subsequent extraction of the sediment with 1 N HCl (study 1).

Comparison of corn gluten meal and meat meal as a protein source in dry foods formulated for cats.

Objective: To compare the nutritional value of corn gluten meal (CGM) and meat meal (MM) as a dietary source of protein in dry food formulated for adult cats.

Animals: 8 healthy adult cats (4 males and 4 females).

Procedure: Diets containing CGM or MM as the main protein source were each fed for a 3-week period in a crossover study.