Hormonal status of cortisol and dehydroepiandrosterone sulfate in an elderly Tunisian population

Adrenal function and aging have been the object of intense interest recently, especially as regards dehydroepiandrosterone sulfate (DHEA-S), which is of major importance, since it is distinct from cortisol and aldosterone in declining with age. In a group of healthy old Tunisians, we investigated the association between cortisol and DHEA-S, on the one hand, and age, sex, lifestyle, physical health, including the body mass index (BMI), physical activity, and smoking indicators, on the other hand. We observed that cortisol concentrations did not change with aging, while DHEA-S concentrations decrease with age in both sexes. Cortisol/DHEA-S ratio, however, increases with aging. Our results revealed that DHEA-S levels are affected neither by physical activity nor by weight. It appears also that current smoking could not affect the level of DHEA-S. Relationships were found between DHEA-S concentrations and BMI, then between DHEA-S levels and serum cholesterol, triglycerides and calcium. No modification in the morning serum cortisol was found to be associated with aging. Decrease in DHEA-S levels is, however, clearly associated with this phenomenon. High cortisol/DHEA-S ratio accelerates the occurrence of some adult diseases, such as diabetes mellitus, atherosclerosis, dementia, and osteoporosis. Generally, the adrenal insufficiency marked by a cognitive impairment, immune disorders, sexual dysfunction, and scores for depression and anxiety can be corrected by a replacement of deficient DHEA-S.     

Toxicity of hexachlorobenzene in Meriones unguiculatus: effects on thyroid and liver

The effect of in vivo administered hexachlorobenzene (HCB) on liver and thyroid was studied on Meriones unguiculatus. HCB (1.6, 4, and 16 mg/kg of body weight) has been administered orally to meriones for 30 days. At the end of the experiment, the body weight of the animals did not show significant change. However, the higher dose of HCB treatment led to a pronounced hepatic hypertrophy comparatively to controls. Histological observations revealed many cytomorphological alterations. Cellular necrosis, periportal, and centrolobular vein congestion and cytoplasmic vacuolisation were noted and correlated with the administered doses of HCB. The higher dose of HCB induced modifications in the activities of hepatic transaminases and on thyroid hormones levels: ALAT activity level was more pronounced in males (170+/-24.7 U/l vs. 52.66+/-8.29 U/l in controls) than in females (120+/-12.47 U/l vs. 56+/-5 U/l in controls). However, ASAT activity increased significantly only in females (259+/-29 U/l vs. 244.66+/-18 U/l in controls). Plasma total triiodothyronine (TT3) and total thyroxine (TT4) levels seemed to be sex-dependent in intoxicated animals, since TT4 decreased significantly in males (21.95+/-7.46 nmol/l vs. 40.59+/-1.08 nmol/l in controls) and TT3 in females (1.42+/-0.11 nmol/l vs. 3.96+/-0.48 nmol/l in controls).     

Effect of hexachlorobenzene on some male reproductive parameters in Meriones unguiculatus

Organochlorine pesticides are known to cause disturbances in many physiological functions. The effects of in vivo administered hexachlorobenzene (HCB) on the male testicular function were studied in Meriones unguiculatus. Three groups of sexually mature meriones were orally exposed to 1.6, 4, and 16 mg/kg of body weight in olive oil for 30 days. Morphological and morphometrical estimations were applied to quantify some structural constituents of the testes. Testicular weight was significantly decreased in all treated groups, while no change was noted in seminal vesicle weight. A decrease in the spermatozoid content of the seminiferous tube was noted and appeared correlated with a modification of the process of spermatogenesis. Spermatic activity in HCB-treated animals testes decreased significantly, particularly in the group treated with the higher dose (60+/-3.16% vs. 88+/-4.89% in controls). Plasma testosterone levels were decreased significantly in the groups treated with 4 and 16 mg[HCB]/kg BW (0.48+/-0.08 ng/ml and 0.54+/-0.07 ng/ml) comparatively to controls (1.08+/-0.1 ng/ml) p<0.01.     

Immunohistochemical study of vascular endothelial growth factor (VEGF), tumor suppressor protein (p53) and intercellular adhesion molecule (ICAM-1) in the conjunctiva of diabetic patients

Summary The expression pattern of VEGF, p53 and ICAM-1 was studied in conjunctiva of diabetic patients with and without retinopathy. All patients underwent a complete ophthalmic examination, including retinal fluorescein angiography. Indirect immunoperoxidase method was performed on 20 eyes of 20 patients with type II diabetes without DR and on 5 eyes of 5 patients with PDR. A control study was performed on 6 normal conjunctiva undertaken during cataract surgery. Immunoreactivity of VEGF, p53 and ICAM-1 was found in epithelial, fibroblast and vascular endothelial cells. For the same duration of diabetes, a strong to moderate or weak immunoreactivity was observed in the conjunctiva of patients without retinopathy. In patients with PDR, the expression was strong for all these proteins. The immunoreactivity was correlated between VEGF, p53 and ICAM-1. In the normal conjunctiva, a weak to negative immunostaining was observed. The presence of these proteins in the conjunctiva of diabetic patients without retinopathy may add new data in the pathogenesis of diabetic retinopathy. Further studies are needed to confirm this hypothesis.     

Alleviation of drought stress in faba bean (Vicia faba L.) by exogenous application of β-aminobutyric acid (BABA)

Physiology and Molecular Biology of Plants - Drought stress is one of the most prevalent environmental factors limiting faba bean (Vicia faba L.) crop productivity. β-aminobutyric acid (BABA)...     

Plasma Antioxidants and Human Aging: A Study on Healthy Elderly Tunisian Population

The aging has been described by several theories. It was proposed that free radicals are the major factor involved in this process. This gave birth to the free radical theory of aging. This current theory provides the most popular explanation for how aging occurs at the biochemical/molecular level. Ever since 1956, this theory has received widespread attention and a large body of evidence has been accumulated in support of its hypotheses which were subsequently refined. The free radical theory of aging postulates that age-associated reductions in physiological functions are caused by an irreversible accumulation of oxidative alterations to macromolecules. This accumulation increases with age and is associated with the life expectancy of organisms. Moreover, this theory suggests the existence of an imbalance between reactive oxygen species (ROS)-producing pathways and (ROS)-scavenging pathways, which is responsible for the generation of oxidative stress syndrome. In this article, we evaluate the antioxidant status in a population of healthy elderly Tunisians in comparison with a group of healthy young Tunisian subjects. This study sets out to investigate the age-related changes in glutathione peroxidase (GPx), superoxide dismutase (SOD) activities, and in total antioxidant status (TAS) of human plasma. We have concluded that healthy aging is accompanied with a disturbed antioxidant status.