Antioxidant enzyme level in the testes of cirrhotic rats.

OBJECTIVES: An understanding of the tissue and organ level of antioxidant enzymes that scavenge reactive oxygen species may provide an indication of their susceptibility to free radical-related cytotoxic damage. A direct association between testicular production of excessive reactive oxygen species and male infertility has been noted. We measured the activities of superoxide dismutase and glutathione peroxidase in the testes of thioacetamide-induced cirrhotic rats. METHODS: Antioxidant enzyme activities and trace element levels (copper, zinc, manganese, and selenium) in the testes of thioacetamide-induced cirrhotic and control rats were measured. The statistical difference between the experimental and control groups with regard to the activities of superoxide dismutase and glutathione peroxidase and levels of trace elements was analyzed with Student's t test. RESULTS: Our results showed a significant decrease in the activity of these enzymes in the testes of cirrhotic rats. The testicular levels of copper, zinc, and manganese, which are associated with these antioxidant enzymes, increased, whereas selenium decreased slightly in cirrhotic rats; that decrease was not statistically significant. CONCLUSIONS: Our studies showed a drastic decrease in the level of antioxidant enzymes in the testes of cirrhotic rats that could have deleterious effects on sperm function in these animals. Further studies are necessary to understand the exact pathways of trace element metabolism in the testes of cirrhotic rats.

Vascular stroma-derived endothelial colony forming progenitor cells adapt to tumour growth.

Under appropriate nutrient agar culture conditions, primary or xenografted human and animal tumour biopsy-derived cell suspensions will form two types of colony. The first type, consisting of tight colonies of round cells which form tumours when introduced into nude mice, is of neoplastic origin. The second type of colony, the cells of which fail to form tumours on injection into nude mice, consists of loose colonies of larger, inter-connecting elongated bi- or tripolar cells and is thought to originate from vascular stroma-derived endothelial colony forming progenitor cells (V-ECPC). The likely importance of V-ECPC to tumour growth is emphasised by a positive correlation between the VECPC-derived endothelial cell colonies and both tumour vascularity and growth rate. A high cloning efficiency obtained from tumours of particularly intense vascular nature indicates that this cell is of importance in vascular adaptation and therefore tumour growth. In contrast, avascular, fibrotic tumour tissue yielded very low numbers of stromal vascular endothelial cell colonies. The results suggest that stromal vascular endothelial cell colonies do not arise from the mature fibroblastic elements of the tumour stroma, but rather from cells within actively growing regions. Tritiated thymidine uptake studies show that the vascular stroma-derived endothelial colony forming progenitor cells cell are cycling. Cell separation studies have characterized the as yet morphologically unidentified V-ECPC as having a sedimentation rate of 4.7 mm./hr and a mean density of 1.068 g/cm3 and hence a calculated volume of 450 microns 3.

Inhibition of Ras-GTPase farnesylation and the ubiquitin-proteasome system or treatment with angiotensin-(1-7) attenuates spinal cord injury-induced cardiac dysfunction.

Cardiovascular diseases are one of the principal causes of death and disability in people with spinal cord injury (SCI). The present study was designed to investigate if acute treatment with FPTIII (an inhibitor of Ras-GTPase farnesylation) or MG132 (an inhibitor of ubiquitin-proteasome pathway [UPS]) or administration of angiotensin-(1-7), also known as Ang-(1-7), (a known inhibitor of cardiac NF-kB) would be cardioprotective. The weight drop technique produced a consistent contusive injury of the spinal cord at the T13 segment. Hearts were isolated from rats either 6 months (SCI-6) or 12 months (SCI-12) after SCI. Hearts were perfused for 30 min and then subjected to 30 min ischemia followed by 30 min reperfusion (I/R). Recovery of cardiac function after I/R was measured as left ventricular developed pressure (P(max)) and coronary flow (CF). Drugs were given during perfusion before hearts were exposed to ischemia and reperfusion. Percent recovery (%R) in P(max) and CF in hearts from control animals were 48±6 and 50±5, respectively, whereas none of the hearts from animals with SCI recovered after 30 min of ischemia. Treatment with FPTIII, MG 132, or Ang-(1-7) before ischemia for 30 min led to significant recovery of heart function following ischemia in SCI-6 but not in SCI-12 animals. Thus we have shown that acute treatments with FPTIII, MG132, or Ang-(1-7) improve cardiac recovery following ischemic insult in animals with SCI and may represent novel therapeutic agents for preventing ischemia-induced cardiac dysfunction in patients with SCI.

Butyrylcholinesterase activity in gestational diabetes: correlation with lymphocyte subpopulations in peripheral blood.

PROBLEM: Inefficient clearance of pregnancy-threatening toxins may contribute to gestational diabetes (GD) and Type II diabetes mellitus (DM) through mechanisms involving immune dysregulation. METHOD OF STUDY: Peripheral venous blood from pregnant Kuwaiti women in third trimester, including 15 GD and 17 DM patients, 14 healthy pregnant (HP) and eight non-pregnant subjects, was analyzed by two-color flow cytometery for number and percentage representation of T lymphocytes. Buterylcholinesterase (BuChE) activity was measured using buterylthiocholine iodide and spectrophotometry. RESULTS: Relative to HP, GD patients exhibited higher ratios of activated and memory phenotypes, including CD4+ CD25+ (P < 0.01), CD4+ HLA-DR (P < 0.05) and CD4+ CD45RO+ (P < 0.05) cells. Serum BuChE activity exhibited positive correlation within the HP cohort with CD4+ CD25+ (P < 0.05), but not in GD and DM cohorts. CONCLUSIONS: Positive correlation between BuChE and a (presumptive) 'regulatory' T-cell phenotype in HP, but not GD or DM may indicate existence of protective detoxification mechanisms against oxidative stress in normal pregnancies.

Major lymphocyte populations and T-cell expression of ICAM-1 and L-selectin adhesion molecules in Kuwaitis with asthma and rhinitis.

The authors evaluate major immunologic features of asthma and allergies in a Kuwaiti population. They analyzed peripheral venous blood from 17 asthmatic and 17 healthy long-term residents of Kuwait by using two-color flow cytometry for major lymphocyte subpopulations; they also evaluated 10 healthy individuals who had recently arrived in Kuwait. Relative to healthy subjects, asthmatics exhibited increased percentages of T+ NK cells (p < .01), T-helper cells (p < .05), T-cytotoxic and NK cells for both total numbers (p < .01-.001) and percentages (p < .05-.01), and increased percentages of T cells expressing CD54 (ICAM-1; p < .001) and CD62 (L-selectin; p < .01). However, B cells were present at significantly lower levels in asthmatics, both in total numbers (p < .05) and percentages (p < .01). In comparison with healthy individuals who had recently arrived in Kuwait, healthy long-term residents exhibited elevated numbers of pan-T cells (p < .01) and T-helper cells (p < .05). These results help establish immunological parameters for asthma and allergies in Kuwaiti populations.

In vitro effects of astaxanthin combined with ginkgolide B on T lymphocyte activation in peripheral blood mononuclear cells from asthmatic subjects.

This study was undertaken to identify novel approaches to pharmacological treatment of asthma. Here we hypothesize that the platelet-activating factor receptor antagonist ginkgolide B (GB) in combination with the antioxidant carotenoid astaxanthin (ASX) suppresses T cell activation comparably to two commonly-used antihistamines: cetirizine dihydrochloride (CTZ) and azelastine (AZE). Peripheral blood mononuclear cells from asthmatics, cultured 24 h with either 50 microg/ml phytohemaglutinin (PHA) or PHA plus selected dosages of each drug are analyzed by flow cytometry for CD25+ or HLA-DR+ on CD3+ (T cells). Results are reported as stimulation indices (SI) of %CD3+CD25+ cells or %CD3+HLA-DR+ cells in cultures treated with PHA alone versus these subpopulations in cultures treated with both PHA and drugs. Combinations of ASX and GB exhibited optimal suppression at 10(-7) M GB + 10(-8) M ASX for CD3+CD25+ (SI = 0.79 +/- 0.04, P = 0.001) and 10(-7) M GB + 10(-7) M ASX for CD3+HLA-DR+ (SI = 0.82 +/- 0.05, P = 0.004). In conclusion, suppression of T cell activation below fully stimulated values by GB, ASX, and their combinations was comparable and for some combinations better than that mediated by CTZ and AZE. These results suggest that ASX and GB may have application as novel antiasthmatic formulations.