Human suppressor T cells induced in vitro with an autologous renal allograft-derived T cell line. II. Activity and specificity of a soluble suppressor factor

Human suppressor T cells induced by autologous mixed lymphocyte reaction (AMLR) using fresh responder PBL from a renal transplant recipient and an autologous irradiated antidonor CTL line (EE-1) established from a biopsy of the patient's own allograft were studied for the production of suppressor factors. The suppressor cell lines propagated (designated TsEE) were capable of inhibiting the in vitro generation of proliferative and cytotoxic responses of responder cells from the recipient or other individuals who shared HLA-B7 with TsEE cells, regardless of the stimulatory cell phenotype. Coculture of TsEE cells with the autologous irradiated EE-1 inducer cell line in vitro yielded a soluble factor (designated TsEEF) capable of inhibiting the generation of MLR and CTL responses, as well as mitogen-induced proliferative responses to PHA and PWM in an HLA-unrestricted manner. TsEEF also inhibited the replication of lymphoblastoid T cell lines (Molt-4 and HSB) but not B cell lines (SB and JC-EBV) or PBL stimulated with the B cell mitogen LPS. Control supernatants obtained from each of the cells used to generate TsEE in AMLR (i.e., EE-PBL and the EE-1 line) cultured alone or together for 48 hr demonstrated no suppressive activity in any of these test systems. TsEEF was nontoxic for lymphoid cells, was nondialyzable (greater than 12kDa), did not act by interfering with IL-1 or IL-2 utilization, and was negative for TNF and IFN-gamma activity. Functionally, the suppressive activity of TsEEF was dose-dependent, did not shift MLR kinetics, and could be absorbed by T cells. T cells incubated with TsEEF for 4 hr were unresponsive to subsequent mitogen or MLR stimulation. These findings indicate that, whereas T suppressor cell lines propagated from the circulation of a stable renal transplant recipient demonstrate class I HLA restriction, the activity of their soluble products is not HLA-restricted, and functionally inhibits T cell proliferation.     

压电频移中和萃取法测定微克量枸橼酸维静宁

用涂圈压电石英晶体频移一中和萃取法测定枸橼酸维静宁(咳必清),检出限0.02μg,在0.05～1.6μg范围内呈线性,相关系数0.999,变异系数为2.3%。与经典的中和萃取法相比,本法具有明显的优越性。     

A dose-response study of graded reoxygenation on the carotid haemodynamics, matrix metalloproteinase-2 activities and amino acid concentrations in the brain of asphyxiated newborn piglets

PURPOSE: It is controversial to choose an appropriate oxygen concentration to resuscitate asphyxiated newborns regarding the clinical and biochemical oxidative effects. We examined the vasomotor response to reoxygenation with graded reoxygenation and the effects on matrix metalloproteinases and amino acids of the immature brain. METHODS: Thirty-two piglets (1-3 days, 1.5-2.1 kg) were instrumented for continuous monitoring of left common carotid and pulmonary arterial flows (Transonic). Piglets were randomized to a sham-operated control group (without hypoxia/reoxygenation) or 2 h hypoxia induced by decreasing the inspired oxygen concentration to 10-15%, followed by reoxygenation with 21, 50 or 100% oxygen for 1 h and then 21% oxygen for 3 h (n=8 each). The brains were then flash frozen and analyzed for matrix metalloproteinases and amino acid levels by zymography and HPLC, respectively. RESULTS: After 2 h oxygen deprivation, the absolute carotid flow remained similar but accounted for 38% of cardiac output (increased from 17% at baseline, p=0.001). During early reoxygenation, the flow rose in the piglets resuscitated with air (p<0.05), but not in those with supplemental oxygen. Carotid vascular resistance correlated significantly with the arterial partial pressure of oxygen (r=0.7). There was an oxygen-dependent increase in global cerebral activity of matrix metalloproteinase-2 with specific increases in the basal ganglia of all hypoxic-reoxygenated brains. There were no significant differences in glutamate and other amino acids in any brain regions. CONCLUSIONS: Although using high oxygen concentration to resuscitate asphyxiated newborn piglets increased carotid vascular resistance and cerebral matrix metalloproteinase-2 activity, there is no detrimental effect observed in this acute model of hypoxia-reoxygenation.     

Immunotoxicological Study of One of the Most Common Over-The-Counter Pyrethroid Insecticide Products in Egypt

A commonly available aerosolized pyrethroid insecticide containing deltamethrin and imiprothrin is widely used for hygienic control in Egypt. The immunotoxic effects after inhalation exposures to the preparation of each for 2, 10, and 30 days were investigated in rats. For each exposure, the insecticide (containing 0.2% imiprothrin and 2.5% deltamethrin) was sprayed in all directions in a room (using a special attachment located in the ceiling in the center of the room) for 30 s each minute for 15 min; the room was then kept closed for 15 min. After each spray interval, the rats were introduced for 30 min and then removed to a clean room. The exposure process was repeated a total of three times on each day of the respective regimens. The interval between the 15-min spray/15-min pause/30-min rat exposure cycles was 120 min. Twenty-four hours after the final exposure in each particular regimen, the cohort rats in the regimen (air and exposed) were weighed, sacrificed, and their tissues were removed for analyses. Immunological tests performed included assessments of potential changes in immunopathology (determined from body and splenic weights), humoral-mediated immunity (based on plaque-forming activity of spleen cells), cell-mediated immunity (determined from splenic lymphocyte responsiveness to stimulation with phytohemagglutinin and immune cell (sub)type profile analyses), and nonspecific immunity (based on phagocytic activity of peritoneal macrophages). The results indicated that of all the endpoints examined, among the rats exposed over a 2-day period to the imiprothrin- and deltamethrin-containing insecticide aerosol, the only significant change noted (relative to values from time-matched controls) was in the levels of splenic CD4⁺CD8^? and CD4⁺ CD8⁺ cells. In contrast, exposures on each day of a 10-day period led to significant decreases in several endpoints; exceptions to this were values for body and spleen weight (unaffected), splenic OX12^?OX19⁺ levels (significant increase), and CD4⁺CD8^? levels (unaffected, relative to control). Rats exposed for 30 days displayed significant decreases in each test applied, except for increases in both splenic OX12^?OX19⁺ and CD4⁺CD8^? cell levels relative to corresponding control rat values. The present study findings indicate that repeated noncontinuous inhalation of a commonly utilized insecticide that contains imiprothrin and deltamethrin can cause a variety of immunotoxic effects in sites distal to the lungs.     

Green tea attenuates benzene-induced oxidative stress in pump workers

Workers exposed to benzene frequently suffer from toxicities of the bone marrow as well as the central nervous, immune, and reproductive systems. This toxicity most likely is a result of the oxidative metabolism of benzene to reactive products. As green tea possesses antioxidant effects, the objective of this study was to examine any amelioration of benzene-induced oxidative stress in pump workers drinking 6 cups (150 ml/cup) of freshly prepared tea daily. Sixty male non-smoking subjects, divided into four groups: no benzene exposure/no green tea; no exposure/tea; exposure/no tea; and, exposure/tea, were monitored after a 6 mo period. On the final day of the study, urine samples were collected for analyses of benzene, trans-trans muconic acid, and phenol. Blood was also collected at this time; plasma was assayed for total antioxidant activity, malondialdehyde (MDA), and glutathione (GSH) while erythrocytes were analyzed for activity of antioxidant enzymes glutathione peroxidase (GSHPX), superoxide dismutase (SOD), and catalase. The results demonstrated that urinary levels of benzene, trans-trans muconic acid, and phenol were elevated in all pump workers, and that this elevation was mitigated by consumption of green tea. The benzene exposures also led to significant reductions in plasma GSH levels and erythrocyte antioxidant enzyme activities; these effects were abrogated (to near-control levels) by the tea. Interestingly, among control subjects, tea ingestion itself caused significant increases in both GSHPX and catalase activities. Unlike with the other plasma parameters, while the benzene exposures also significantly increased plasma MDA levels and decreased total antioxidant activity, tea ingestion did not cause a near-total reversion to control values; the effects on these two endpoints were more like those noted with the urine parameters (mitigation, not abrogation). These studies demonstrate that drinking green tea during benzene exposure can reduce several parameters indicative of oxidative stress. As such, as a dietary supplement, green tea could represent a potential therapeutic agent in reducing certain aspects of benzene-induced toxicity.     

Assessment of hepatic and cardiac iron overload in thalassemia patients by magnetic resonance imaging: Our experience in Alexandria University

Aim of the study

The aim of this study was to assess the utility of MRI as a non-invasive technique for grading of the hepatic and cardiac iron overload in Thalassemia patients in a cohort of patients in Alexandria, Egypt.