Resistance of Crohn's disease T cells to multiple apoptotic signals is associated with a Bcl-2/Bax mucosal imbalance.

Crohn's disease (CD) is a condition characterized by excessive numbers of activated T cells in the mucosa. We investigated whether a defect in apoptosis could prolong T cell survival and contribute to their accumulation in the mucosa. Apoptotic, Bcl-2+, and Bax+ cells in tissue sections were detected by the TUNEL method and immunohistochemistry. T cell apoptosis was induced by IL-2 deprivation, Fas Ag ligation, and exposure to TNF-alpha and nitric oxide. TUNEL+ leukocytes were few in control, CD, and ulcerative colitis (UC) mucosa, with occasional CD68+ and myeloperoxidase+, but no CD45RO+, apoptotic cells. Compared with control and UC, CD T cells grew remarkably more in response to IL-2 and were significantly more resistant to IL-2 deprivation-induced apoptosis. CD T cells were also more resistant to Fas- and nitric oxide-mediated apoptosis, whereas TNF-alpha failed to induce cell death in all groups. Compared with control, CD mucosa contained similar numbers of Bcl-2+, but fewer Bax+, cells, while UC mucosa contained fewer Bcl-2+, but more Bax+, cells. Hence, the Bcl-2/Bax ratio was significantly higher in CD and lower in UC. These results indicate that CD may represent a disorder where the rate of T cell proliferation exceeds that of cell death. Insufficient T cell apoptosis may interfere with clonal deletion and maintenance of tolerance, and result in inappropriate T cell accumulation contributing to chronic inflammation.

The expression of CNTF message and immunoreactivity in the central and peripheral nervous system of the rat.

We have examined the temporal and spatial expression of ciliary neurotrophic factor (CNTF) and its messenger RNA (mRNA) by immunocytochemistry and Northern blot analysis. Specific CNTF-like (CNTF-IR) immunoreactivity and CNTF message were detected primarily in sciatic nerve, spinal cord, and optic nerve sections in the adult rat. In the sciatic nerve immunostaining was localized primarily to the Schwann cell cytoplasm. Schwann cells in the dorsal root ganglion and in the spinal motor roots were immunoreactive for CNTF but no CNTF immunoreactivity was detected in Schwann cells associated with unmyelinated sympathetic fibers in the superior cervical ganglion. CNTF-IR was first detected in sciatic nerve sections on postnatal day 8 and increased in intensity until reaching adult levels by postnatal day 21. In the adult rat, optic nerve staining was confined to astrocyte-like cells and their projections, and this pattern of immunoreactivity was first apparent at postnatal day 8. Double labelling experiments suggest that a GFAP-positive cell in the optic nerve synthesizes CNTF. In the spinal cord, CNTF-IR was seen only in white matter non-neuronal cells at all ages studied. Branched oligodendrocyte-like cells appeared stained and the staining was first apparent at postnatal day 8. The data, therefore, suggest that myelinating Schwann cells produce CNTF and demonstrate the presence of CNTF and its messenger RNA at the appropriate time period in tissues previously defined as having biological responses to CNTF.

Pirenperone effects on temperature preference and body temperature in maturing mice.

Thermoregulatory effects of the selective 5-HT2 antagonist pirenperone were studied 1 hr after IP injection in mice aged 1, 3, 5, 7 and 10 days postpartum. Compared with vehicle injected littermates, a dose of 0.16 mg/kg decreased temperature preference (T pref) on a thermal gradient at all ages. No significant effects were observed on body temperature (Tb) at any of the ages. An increased dose (0.48 mg/kg) caused no greater effect on T pref and no significant effect on Tb. These results indicate that Tb and T pref are separable on the basis of receptor pharmacology, and are discussed in relation to drug effects on 5-HT2 receptors.

The effect of rapid weight loss due to jejunoileal bypass on total cholesterol and high-density lipoprotein.

Twelve patients undergoing a 10 to 4 inch end-to-side jejunoileal bypass for morbid obesity were measured pre- and postsurgically for total cholesterol and high-density lipoprotein (HDL) cholesterol levels. After a mean weight loss period of 7 months, results showed a significant decrease in total cholesterol (p less than 0.001) and in the total cholesterol: HDL cholesterol level (p less than 0.01). The change in HDL cholesterol levels was not significant (p less than 0.05). The decrease in total cholesterol accompanied by no change in HDL cholesterol indicates an increased transport of cholesterol as HDL in these patients. This results suggests that these subjects are placed at a decreased risk of coronary heart disease postsurgically.

Temperature dependence of the chromatographic assay of hemoglobin A1 and application of a temperature controlled assay to clinical evaluation of diabetic control.

We investigated the temperature dependence of the cation-exchange chromatographic properties of hemoglobin A1 using the "Fast Hemoglobins Test System" obtained from Isolab, Inc., Akron, OH, U.S.A. and a temperature control chamber constructed in our laboratory. Six patient samples, two each from the "normal" range (5--8.5%, "transitional" range (8.5--12.0%) and "uncontrolled diabetic" range (12--20%) described by Isolab (as measured at 24 degrees C) were collected, hemolyzed and assayed according to product insert instructions. Each sample was assayed in triplicate in three separate runs at 20 degrees C, 22 degrees C, 24 degrees C, 26 degrees C and 28 degrees C in the temperature controlled (+/- 0.25 degrees C) chamber. Resultant mean increases in assay results of 0.8, 1.1 and 1.6% hemoglobin A1 per 2 degrees C increase in temperature for the three ranges respectively, indicate that the temperature dependence of the microcolumn assay for hemoglobin A1 is at least partially a function of the relative percentage of glycosylated hemoglobin in the sample. By controlling assay temperature we have reduced interassay variation throughout all concentration ranges by more than one-half to less than 5%. We applied this temperature controlled assay to measurement of hemoglobin A1 levels in 33 non-diabetic subjects and to the screening of hemoglobin A1 levels in 77 diabetic patients regularly attending the diabetic-endocrine outpatient clinic of this hospital. No non-diabetic subject had a HbA1 level above 8.5% and of the diabetic patients, 26% fell within the "normal" range, 43% within the "transitional" range and 31% within the "uncontrolled diabetic" range.