Changes in phospholipid composition of the mitochondrial membrane after orthotopic liver transplantation

Changes in phospholipids and their fatty acid composition in liver mitochondria obtained from allogenic rats with orthotopic liver transplants were measured with and without immunosuppressive treatment. In untreated allogenic rats, mitochondrial phosphorylation activity was severely deteriorated at 8 days after transplantation. A significant change was also found in the amount of cardiolipin compared with other classes of phospholipids. Namely, cardiolipin decreased, and lysodiphosphatidylglycerol and phosphatidylglycerol increased concomitantly. Furthermore, the percentage of linoleic acid in cardiolipin decreased dramatically. Decrease in cardiolipin and changes in its fatty acid composition may be attributed to the deterioration of mitochondrial function upon acute rejection.     

Plasma corticosterone and restraint induced gastric pathology: age-related differences after administration of corticotropin releasing factor

Corticotropin releasing factor (CRF) or saline was administered i.p. to rats aged either 100 or 220 days, followed by either brief handling or water immersion restraint. Plasma corticosterone was measured 75 min. later. Age of the animals in itself was not a significant factor either for basal levels of plasma corticosterone or for extent of restraint induced gastric pathology. However after CRF administration, young but not older animals revealed a significant increase in plasma corticosterone levels, and post restraint gastric ulcerations were more severe in older than young animals. CRF significantly decreased the number of restraint induced ulcers in young rats, while the cumulative ulcer length was increased in older animals.     

Endothelium-derived relaxing factor (nitric oxide) has protective actions in the stomach

The role that nitric oxide, an endothelium-derived relaxing factor, may play in the regulation of gastric mucosal defence was investigated by assessing the potential protective actions of this factor against the damage caused by ethanol in an ex vivo chamber preparation of the rat stomach. Topical application of glyceryl trinitrate and sodium nitroprusside, which have been shown to release nitric oxide, markedly reduced the area of 70% ethanol-induced hemorrhagic damage. Topical application of a 0.01% solution of authentic nitric oxide also significantly reduced the severity of mucosal damage. Pretreatment with indomethacin precluded the involvement of endogenous prostaglandins in the protective effects of these agents. The protective effects of NO were transient, since a delay of 5 minutes between NO administration and ethanol administration resulted in a complete loss of the protective activity. The protection against ethanol afforded by 10 micrograms/ml nitroprusside could be completely reversed by intravenous infusion of either 1% methylene blue or 1 mM hemoglobin, both of which inhibit vasodilation induced by nitric oxide. Intravenous infusion of 1% methylene blue significantly increased the susceptibility of the mucosa to damage induced by topical 20% ethanol. These results indicate that ethanol-induced gastric damage can be significantly reduced by nitric oxide. The mechanisms underlying the protective actions of nitric oxide are unclear, but may be related to its vasodilator or anti-aggregatory properties.     

Stress and immunity: an integrated view of relationships between the brain and the immune system

The old notion that stress exacerbates the progression of physical illness via its corticosteroid-mediated immunosuppressive effects must be revised. Experimental and clinical studies demonstrate that both laboratory and natural stressors alter the activities of lymphocytes and macrophages in a complex way that depends on the type of immune response, the physical and psychological characteristics of the stressor and the timing of stress relative to the induction and expression of the immune event. The influences of stress on immunity are mediated not only by glucocorticoids but also by catecholamines, endogenous opioids and pituitary hormones such as growth hormone. Sensitivity of the immune system to stress is not simply fortuitous but is an indirect consequence of the regulatory reciprocal influences that exist between the immune system and the central nervous system. The immune system receives signals from the brain and the neuroendocrine system via the autonomic nervous system and hormones and sends information to the brain via cytokines. These connections appear to be part of a long-loop regulatory feedback system that plays an important role in the coordination of behavioral and physiological responses to infection and inflammation.     

Species preservations in an optimal harvest model with random prices

In this paper, we consider an optimal harvest model in which the objective is to maximize the expected return. The unit price of biomass is assumed constant until a random time when the price increases by a given amount. Furthermore, due to obvious environmental protection requirements, it is assumed that the fishery population is bounded from below for all time so as to reduce the danger of species extinction. Clearly, this problem is an optimal control problem in which a random parameter is involved. However, due to its special structure, it is shown that the problem is convertible into a deterministic optimal control problem and hence is solvable by an existing optimal control software package, MISER. The practical implication of several computed results obtained by this approach is discussed. They are also compared with other related results in the literature.     

Nonresponsiveness of the thyroid gland to goitrogen in the early neonatal period in the rat: light- and electron-microscopic observations.

The thyroid response of fetal and neonatal rats to propylthiouracil (PTU) as a goitrogen was studied with observation of the thyroid glands by light and electron microscopy. On day 19 of gestation and on days 1, 3, 5 and 8 after birth, fetal and neonatal rats were given a subcutaneous injection of PTU and were autopsied 2 days later. PTU induced conspicuous goiters in fetal rats but did not in neonatal rats aged up to day 5 after birth. Beyond that age, PTU again induced goiters. Histologically, the follicular cell height in goitrous thyroid glands was significantly increased. Ultrastructurally, follicular cells in goitrous thyroid glands often had colloid droplets and lysosomes. It seems that nonresponsiveness of the thyroid glands in early neonatal rats to goitrogen is due to a temporary decline of the pituitary activity of thyrotropin secretion. About 5 days or more after birth, the pituitary-thyroid system begins to operate again in response to goitrogen.     

Sex differences in adrenocortical structure and function: 29. Morphometric and functional studies on the effects of gonadectomy and gonadal-hormone replacement on the hamster adrenal cortex.

The morphologic changes evoked in the adrenal glands of male and female hamsters by gonadectomy (15 weeks) and gonadal-hormone replacement (single s.c. injection of 5 mg/100 g b.w. testosterone or 0.5 mg/100 g b.w. estradiol, 2 weeks before the sacrifice) were investigated by morphometric techniques and correlated with the functional alterations of the hypothalamopituitary-adrenal axis. Our findings evidenced a stimulatory role of androgens and a moderate inhibitory one of estrogens on the growth and steroidogenic capacity of the adrenal glands in male and female hamsters, respectively. Moreover, they suggest that these adrenal effects of gonadal hormones are, at least partly, independent of alterations in the pituitary ACTH release.     

Colloid carcinoma of the breast with concomitant metastasis and a tuberculous lesion in the axillary lymph nodes. A case report.

A 30-year-old woman presented with a lump in the left breast and left axillary lymphadenopathy that, on fine needle aspiration cytology (FNAC), proved to be duct cell carcinoma with metastasis. Histology of the radical mastectomy specimen showed a mixed colloid carcinoma. Axillary lymph nodes revealed a variety of pathologic changes consisting of reactive hyperplasia, tuberculosis and metastasis. A combination of a tuberculous lesion and metastasis in the same lymph nodes was also found. During follow-up, after radiotherapy, the patient developed left supraclavicular and right cervical lymphadenopathy that, on FNAC, revealed a tuberculous lesion and metastasis, respectively. The rarity of this condition with double pathology is highlighted, and the reason behind the limitations of FNA in subtyping the primary malignancy and its failure to detect the tuberculous lesion in the axillary lymph node are discussed.     

Enzyme-based high-performance liquid chromatography supports as probes of enzyme activity and inhibition: the immobilization of trypsin and alpha-chymotrypsin on an immobilized artificial membrane high-performance liquid chromatography support.

Immobilized artificial membrane (IAM) HPLC supports have been used to immobilize the enzymes alpha-chymotrypsin and trypsin. The enzymes were trapped in hydrophobic cavities on the support and were not covalently attached to the IAM surface. The resulting IAM-enzyme supports retained the hydrolytic activity of the immobilized enzymes: the IAM-trypsin support catalyzed the hydrolysis of N alpha-benzoyl-DL-arginine-p-nitroanilide (BAPNA), and the IAM-alpha-chymotrypsin support (IAM-ACHT) catalyzed the hydrolysis of a number of substrates, including tryptophan methyl ester. The activities of both supports were decreased by known enzyme inhibitors and the activity of the IAM-ACHT was affected by changes in pH and temperature. When a substrate was chromatographed on an IAM-ACHT HPLC, the hydrolytic activity of the immobilized enzyme could be determined from the resulting substrate/product ratios. These data were obtained either directly from the IAM-ACHT chromatogram or from the chromatogram produced by a coupled column system. The results of this study indicate that IAM-immobilized alpha-chymotrypsin and trypsin can be used as chromatographic probes for the qualitative determination of enzyme/substrate and enzyme/inhibitor interactions.