Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although the current risk of posttransfusion infection is very low in North America and Western Europe, there continues to be considerable interest in measures to inactivate residual viruses in blood components. The human immunodeficiency virus is of greatest concern, but hepatitis C virus is also considered to be a significant problem. HTLV-I and -II and HBV may also be transmitted by transfusion, although infrequently. It is likely that effective inactivation methods will have to reduce viral titers by about 6 orders of magnitude, including both viruses found free in plasma and those in intracellular compartments. Although it would be most desirable to have a single procedure to inactivate viruses in all blood components, it appears that different methods may be required for plasma, red cells and platelets. To date, the most promising approach for platelets appears to be photochemical inactivation. In general, photoactive compounds fall into two major groups: photodynamic dyes which are activated by visible light and act by oxygen dependent generation of reactive molecular species; and ultraviolet-activated intercalating compounds which form covalent adducts with nucleic acids. We have found that photodynamic inactivators are unable to inactivate viruses in platelet concentrates without damaging the platelets. On the other hand, we have shown that aminomethyl trimethyl psoralen (AMT), when activated by long-wavelength ultraviolet light (UVA) can inactivate more than 5 logs of model viruses and HIV while platelet in vitro properties are maintained. Further, unlike photodynamic inactivators, AMT is able to inactivate cell-associated and intracellular viruses and also prevents the replication of integrated HIV genome sequences, as demonstrated by PCR.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Viral inactivation in platelet concentrates. 804 13

Sodium hypochlorite (NaOCl) is widely used to inactivate retroviruses topically and on environmental surfaces. This proposal establishes the thesis that sodium hypochlorite and its related oxygen free radicals can be administered in minute quantities in vivo to achieve a reduction in retroviral titer within the infected individual. Published reports of animal studies and accidental sodium hypochlorite infusion in much greater concentrations have indicated that the protein depletion and oxidation of sulfhydryl compounds is reversible and possibly preventable by administration of disulfide reducing agents. Various methods of infusion can include the ex vivo retroviral inactivation of plasma utilizing extracorporeal circulation through a continuous centrifugal plasma separator. The utilization of infusion of low-concentration sodium hypochlorite dialysate for retroviral inactivation merits immediate experimental study. Chlorinated tap-water and table salt ingestion must also be among the environmental factors studied for correlation to HIV infection.
 ...
PMID:Proposal for experimental studies to evaluate sodium hypochlorite dialysate in retroviral treatment. 805 71

The US blood supply is once again expanding (14 million units a year) and annual estimated whole blood and red blood cell (RBC) transfusion now exceeds 12 million units. The observed increase in total transfusions and units transfused per surgical procedure may result from more aggressive therapies, an aging population, and improved access to health care. While autologous blood collection has grown 20-fold in the past decade, autologous blood still accounts for < 8% of transfusions and is unlikely to replace much more of the allogeneic transfusion needs. Although safer than ever, allogeneic blood still transmits infectious disease (HIV:1 in 225,000 units, hepatitis:1 in 3300 units, HTLV I/II:1 in 50,000 units) and poses additional immunologic and non-immunologic risks. Allogeneic RBCs are probably underutilized because of safety concerns. While the cost of a unit of RBCs has been estimated at $150, costs are substantially higher in some areas and blood processing (filtration, gamma irradiation, washing) add additional expense. The narrowing margin between supply and demand, and repeated regional blood shortages argue for the value of safe, effective oxygen carriers.
 ...
PMID:Oxygen carriers and transfusion medicine. 808 36

We attempted to measure cardiopulmonary effects, CD4 counts, and perceived sense of well-being in 25 individuals moderately to severely immunocompromised from HIV infection (mean entry CD4 count = 144.microliters-1) before and after a 24-wk program of exercise training. Only six subjects completed the 24-wk program. All six showed evidence of a training effect. Statistically significant improvements were seen in maximal oxygen consumption (VO2max), oxygen pulse, and minute ventilation. Submaximal exercise performance improved significantly by 12 wk in the 10 individuals available for testing: decreases were seen in heart rate, rate pressure product, and rate of perceived exertion. White blood cell counts and T-lymphocyte subsets were stable at 12 and 24 wk in the subjects available for testing. High depression/anxiety scores on a mental health inventory (General Health Questionnaire) correlated with low CD4 counts. Scores did not correlate with compliance with the exercise program. There was a trend (P < 0.10) for scores to improve over time among those individuals who attended > or = 80% of scheduled exercise sessions. We conclude that exercise training is feasible and beneficial for some HIV-infected individuals.
 ...
PMID:Supervised exercise training improves cardiopulmonary fitness in HIV-infected persons. 810 Jun 7

Human immunodeficiency virus (HIV) infection is associated with altered levels of glutathione (GSH) in cells and extracellular fluids. GSH is essential for lymphocyte proliferation and inhibits HIV replication. Therefore, determination of GSH and glutathione disulfide (GSSG) levels could be useful as indicators of the progression of the disease. Thyroid hormone levels are altered in acquired immuno-deficiency syndrome (AIDS), such that thyroid hormone might be a useful prognostic indicator of the severity of AIDS. Pneumocystis carinii pneumonia (PCP) is a debilitating disease of the lung that can accompany HIV infection. The effects of pulmonary infections were assessed in AIDS patients on thyroid hormone, GSH, GSSG levels and other parameters. Two groups of AIDS patients were selected, a group with PCP and a control group with other respiratory diseases. GSH was evaluated in plasma, pulmonary lavage fluid, pulmonary biopsy tissue and buccal cells. Levels of GSSG in pulmonary lavage fluid were higher in PCP patients than in controls, which suggests that PCP patients suffer from oxygen radical toxicity in their lungs. PCP patients may have altered plasma GSH utilization such that damaged lung tissue may become less efficient at using plasma GSH. Patients with PCP may have altered CD4 cell functions such that thyroid hormone levels do not correlate with CD4 cell counts. Patients with AIDS and secondary infections of the lung were found to have altered GSH redox states, probably indicative of physiologic adaptation to AIDS.
 ...
PMID:Pneumocystis carinii pneumonia in HIV infected patients: effects of the diseases on glutathione and glutathione disulfide. 818 48

Neutrophils from asymptomatic HIV-infected patients have an increased Nitroblue tetrazolium (NBT) reduction, that is an increased production of oxygen radicals. Plasma from these patients can activate normal neutrophils to an increased NBT-reduction and the neutrophil activating factor thus seems to be mainly plasma bound. Further, the patients also have increased levels of plasma malondialdehyde and thus an increased lipid peroxidation. Plasma cysteine levels are low, a sign of increased consumption of antioxidants. Treatment of the asymptomatic HIV-infected patients with N-acetylcysteine corrected the plasma cysteine levels and had some beneficial effects, but did not inhibit the increased radical production by the neutrophils.
 ...
PMID:Oxygen radical release by neutrophils of HIV-infected patients. 819 30

Following the initial infection with HIV, there is evidence of immune dysfunction despite an apparent normal clinical state. In the context that the lung is a major site affected by opportunistic infection, and that some components of the immune system are activated during early HIV infection, we hypothesized that there may be activation of alveolar macrophages (AM), a key component of the pulmonary host defense system. Compared to cells from normal individuals, AM of asymptomatic HIV-seropositive (HIV+) individuals (CDC-stage II) spontaneously released significantly more superoxide anion (O2-.) (P < 0.002). The O2-. release by AM of HIV-infected individuals was comparable to the spontaneous O2-.-release by AM of cigarette smokers (P > 0.6), a condition often associated with chronic damage of respiratory tissues. The destructive effects of oxidants are normally suppressed by antioxidant defense systems. Evaluation of the concentrations of glutathione, a major component of the pulmonary antioxidant protective screen, demonstrated that the HIV+ state is also characterized by a significant glutathione deficiency in lung epithelial lining fluid (P < 0.001) and in venous plasma (P < 0.001). This suggests that the alveolar structures of HIV+ individuals are continuously exposed to increased amounts of toxic oxygen radicals without adequate protection, i.e. the reactive oxygen metabolites may cause sufficient tissue damage culminating in interstitial lung disease. Further, since many immune functions are susceptible to injury by extracellular oxidants, the consequences of an unsuppressed oxidant burden in the lung may amplify the extent of local immunocompromise. In addition, since glutathione plays an important role in modulating lymphocyte activation and effector functions independent of its antioxidant activity, the systemic glutathione deficiency may contribute to the progressive global immune dysfunction that characterizes HIV infection.
 ...
PMID:Imbalance between oxidants and antioxidants in the lungs of HIV-seropositive individuals. 819 31

HIV-infected patients and transplanted patients share similar immunosuppressed status. Recent insights gained through the field of heart transplantation may help to clarify the role of reactive oxygen species in HIV-infected patients.
 ...
PMID:Increased production of reactive oxygen species in pharmacologically-immunosuppressed patients. 819 32

Deficiency in antioxidant micronutrients have been observed in patients with AIDS. These observations concerning only some isolated nutrients demonstrate a defect in zinc, selenium, and glutathione. An increase in free radical production and lipid peroxidation has been also found in these patients, and takes a great importance with recent papers presenting an immunodeficiency and more important an increase in HIV-1 replication secondary to free radicals overproduction. We have assessed different studies, trying to obtain a global view of the antioxidant status of these patients. In adults we observe a progressive decrease for zinc, selenium, and vitamin E with the severity of disease, except that selenium remains normal at stage II. However, the main dramatic decrease concerns carotenoids whose level at stage II is only half the normal value. To understand if these decreases in antioxidant and increases in oxidative stress occur secondary to the aggravation of the disease or, conversely, are responsible for it, we undertook a longitudinal survey of asymptotic patients. The preliminary results of this evaluation are presented. Paradoxically, lipid peroxidation is higher at stage II than at stage IV. This may be consecutive to a more intense overproduction of oxygen free radicals by more viable polymorphonuclear (PMN) at the asymptomatic stage. The free radicals production and lipid peroxidation seem secondary to a direct induction by the virus of PMN stimulation and cytokines secretion. N-Acetyl cysteine or ascorbate have been demonstrated in cell culture to be capable of blocking the expression of HIV-1 after oxidative stress and N-acetyl cysteine inhibits in vitro TNF-induced apoptosis of infected cells. In regard to all these experimental data, few serious and large trials of antioxidants have been conducted in HIV-infected patients, although some preliminary studies using zinc or selenium have been performed. In our opinion it is now time to evaluate in humans the beneficial effect of antioxidants. The more promising candidates for presenting synergistic effects when associated with N-acetyl cysteine seem to be beta-carotene, selenium and zinc.
 ...
PMID:Antioxidant status and lipid peroxidation in patients infected with HIV. 819 33

Evidence supports the premise that a pro-oxidant condition exists in HIV-seropositive patients, a result of an overabundance in production of reactive oxygen forms combined with a multilevel deficiency in nutritional and metabolic sources of antioxidants. Apoptosis (a programmed cell death) is recognized as a possible pathway of immune cell loss in patients with HIV infection and AIDS. The cascade of events that results from 'oxidative stress' (OS) is markedly similar to that which can initiate apoptosis and includes oxidation of cellular membranes, alteration of metabolic pathways, disruption of electron transport systems, depletion of cellular ATP production, loss of Ca2+ homeostasis, endonuclease activation and DNA/chromatin fragmentation. Downstream events secondary to these effects may also play a role in activation of latent virus and subsequent viral replication. Primary and secondary metabolites found in plants act as synergistic antioxidants, and can protect plants from oxidation-induced cell death. Experiments have shown that some of these same metabolites can inhibit cell killing by HIV. Can these compounds be useful in inhibiting viral activation and the death of immune cells in HIV/AIDS through their synergistic antioxidant properties? A brief review of the evidence for OS in HIV is presented and the potential basis for OS playing a role in the initiation of cell death and viral replication is explored. The functional antioxidant activities of plant metabolites are illustrated and the use of these synergistic antioxidants from plants are proposed as a mechanism by which viral replication and cell killing in HIV infection can be inhibited.
 ...
PMID:Could oxidative stress initiate programmed cell death in HIV infection? A role for plant derived metabolites having synergistic antioxidant activity. 819 35


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>