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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have studied the action of ascorbate (vitamin C) on human immunodeficiency virus type 1 (HIV-1), the etiological agent clinically associated with AIDS. We report the suppression of virus production and cell fusion in HIV-infected T-lymphocytic cell lines grown in the presence of nontoxic concentrations of ascorbate. In chronically infected cells expressing HIV at peak levels, ascorbate reduced the levels of extracellular reverse transcriptase (RT) activity (by greater than 99%) and of p24 antigen (by 90%) in the culture supernatant. Under similar conditions, no detectable inhibitory effects on cell viability, host metabolic activity, and protein synthesis were observed. In freshly infected CD4+ cells, ascorbate inhibited the formation of giant-cell syncytia (by approximately 93%). Exposure of cell-free virus to ascorbate at 37 degrees C for 1 day had no effect on its RT activity or syncytium-forming ability. Prolonged exposure of virus (37 degrees C for 4 days) in the presence of ascorbate (100-150 micrograms/ml) resulted in the drop by a factor of 3-14 in RT activity as compared to a reduction by a factor of 25-172 in extracellular RT released from chronically infected cells. These results indicate that ascorbate mediates an anti-HIV effect by diminishing viral protein production in infected cells and RT stability in extracellular virions.
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PMID:Suppression of human immunodeficiency virus replication by ascorbate in chronically and acutely infected cells. 169 93

To elucidate the action of vitamin C on pathogenic human retroviruses, we investigated and compared the effects of noncytoxic concentrations of ascorbic acid (AA), its calcium salt (Ca-ascorbate), and two thiol-based reducing agents [glutathione (GSH) and N-acetyl-L-cysteine (NAC)] against human immunodeficiency virus (HIV)-1 replication in chronically infected T lymphocytes. Ca-ascorbate reduced extracellular HIV reverse transcriptase (RT) activity by about the same magnitude as the equivalent dose of AA. Long-term experiments showed that continuous presence of ascorbate was necessary for HIV suppression. NAC (10 mmol/L) caused less than twofold inhibition of HIV RT and conferred a synergistic effect (approximately eightfold inhibition) when tested simultaneously with AA (0.426 mmol/L). In contrast, nonesterified GSH (less than or equal to 1.838 mmol/L) had no effect on RT concentrations and did not potentiate the anti-HIV effect of AA. These results further support the potent antiviral activity of ascorbate and suggest its therapeutic value in controlling HIV infection in combination with thiols.
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PMID:Comparative study of the anti-HIV activities of ascorbate and thiol-containing reducing agents in chronically HIV-infected cells. 172 May 98

This study surveyed serum concentrations of vitamins, electrolytes, and trace elements in subjects seropositive for HIV-1 by ELISA and confirmatory Western blot. Thirty subjects (26 males, 4 females) were recruited at a hospital clinic. Seventeen were classified as having mild or severe ARC (AIDS-related complex), 7 had AIDS, and 6 were asymptomatic. Eight had experienced weight loss of 10 pounds or more in the past 6 months. Most (93%) were anergic to skin test antigens. Percentages of subjects with below normal plasma concentrations include: zinc-30%, calcium-27%, magnesium-30%, carotenes-31%, total choline-50%, and ascorbate-27%. Eighty-seven percent of the subjects had at least one abnormally low value. Percentages with above normal values include: folate-37% and carnitine-37%. Some subjects with above normal values for plasma vitamins reported self-supplementation, usually with large doses. The results suggest that one or more abnormally low concentrations of the plasma micronutrients studied here are likely to be present in the majority of HIV seropositive patients.
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PMID:Micronutrient status and human immunodeficiency virus (HIV) infection. 236 Jul 60

alpha-Lipoic acid, which plays an essential role in mitochondrial dehydrogenase reactions, has recently gained considerable attention as an antioxidant. Lipoate, or its reduced form, dihydrolipoate, reacts with reactive oxygen species such as superoxide radicals, hydroxyl radicals, hypochlorous acid, peroxyl radicals, and singlet oxygen. It also protects membranes by interacting with vitamin C and glutathione, which may in turn recycle vitamin E. In addition to its antioxidant activities, dihydrolipoate may exert prooxidant actions through reduction of iron. alpha-Lipoic acid administration has been shown to be beneficial in a number of oxidative stress models such as ischemia-reperfusion injury, diabetes (both alpha-lipoic acid and dihydrolipoic acid exhibit hydrophobic binding to proteins such as albumin, which can prevent glycation reactions), cataract formation, HIV activation, neurodegeneration, and radiation injury. Furthermore, lipoate can function as a redox regulator of proteins such as myoglobin, prolactin, thioredoxin and NF-kappa B transcription factor. We review the properties of lipoate in terms of (1) reactions with reactive oxygen species; (2) interactions with other antioxidants; (3) beneficial effects in oxidative stress models or clinical conditions.
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PMID:alpha-Lipoic acid as a biological antioxidant. 764 94

The authors sought to determine if different levels of dietary intake of micronutrients are associated with the progression of human immunodeficiency virus type 1 (HIV-1) infection to acquired immunodeficiency syndrome (AIDS). A total of 281 HIV-1 seropositive homosexual/bisexual men were seen semiannually since 1984 at the Baltimore/Washington, DC site of the Multicenter AIDS Cohort Study. Participants completed a self-administered semiquantitative food frequency questionnaire at baseline. Levels of daily micronutrient intake at baseline were examined in relation to subsequent progression to AIDS (1987 Centers for Disease Control definition; n = 108) during a median follow-up period of 6.8 years. For each nutrient, the authors used a Cox proportional hazards model to adjust for age, presence of symptoms, CD4+ lymphocyte count, energy intake, use of antiretrovirals, and use of Pneumocystis carinii pneumonia prophylaxis. The highest levels of total intake (from food and supplements) of vitamins C and B1 and niacin were associated with a significantly decreased progression rate to AIDS: vitamin C (relative hazard (RH) = 0.55, 95% confidence interval (CI) 0.34-0.91), vitamin B1 (RH = 0.60, 95% CI 0.36-0.98), and niacin (RH = 0.52, 95% CI 0.31-0.86). The relation between total vitamin A intake and progression to AIDS appeared to be U-shaped; the lowest and highest quartiles of intake did most poorly, while the middle two quartiles were associated with significantly slower progression to AIDS (RH = 0.55, 95% CI 0.35-0.88). Increased intake of zinc was monotonically and significantly associated with an increased risk of progression to AIDS (for highest vs. lowest quartiles, RH = 2.06, 95% CI 1.16-3.64). In a final multinutrient model, vitamin A, niacin, and zinc remained significantly associated with progression to AIDS, while vitamin C was only marginally significant.
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PMID:Dietary micronutrient intake and risk of progression to acquired immunodeficiency syndrome (AIDS) in human immunodeficiency virus type 1 (HIV-1)-infected homosexual men. 790 21

(1) We evaluated efficacy of several treatments for HTLV-I-associated myelopathy (HAM) on the basis of our study on 254 HAM patients and of literature review. Improvement of motor disability more than fair response was obtained as follows: 82% in prednisolone, 69% in interferon-alpha, 92% in fosfomycin, 82% in high-dose vitamin C, 72% in blood purification therapy, 70% in heparin, 59% in salazosulfapyridine, 56% in thyrotropin-releasing hormone, 55% in erythromycin, 50% in mizoribine. (2) In the absence of clear guideline, the efficacy of zidovudine in the AIDS dementia complex has been demonstrated. There are also efficacy of amytriptylinein controlling HIV headache, corticosteroid in mononeuritis multiple and inflammatory myositis, hydrocortisone in autonomic neuropathy and plasmapheresis in distal sensory neuropathy respectively. Otherwise, it is emphasized that ddI, ddC and d4T have peripheral neuropathy as major, dose related side effect.
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PMID:[Therapy for HAM/TSP and AIDS]. 799 4

U1 cells, a subclone of U937 cells chronically infected with human immunodeficiency virus type 1 (HIV-1), produced HIV-1 only in the presence of inducers such as 12-O-tetradecanoxylphorbol 13-acetate (TPA) or tumor necrosis factor (TNF)-alpha. The expression of HIV-antigen on U1 cells induced by TPA or TNF-alpha was found to be prevented by sodium 5,6-benzylidene-L-ascorbate (SBA) in a concentration-dependent manner. Treatment of U1 cells with SBA in the presence of inducers resulted in cell death with cell shrinkage, chromatin condensation and DNA fragmentation into nucleosomal oligomers, characteristics of apoptosis. In contrast, SBA had scarcely any apoptotic effect on U1 cells in the absence of inducers. SBA did not also induce apoptosis in parental U937 cells in the presence or absence of inducers. These results suggest that HIV-replicating U1 cells selectively undergo apoptosis on treatment with SBA.
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PMID:Sodium benzylideneascorbate induces apoptosis in HIV-replicating U1 cells. 807 75

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.
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PMID:Antioxidant status and lipid peroxidation in patients infected with HIV. 819 33

After the development of monophasic combined oral contraceptives (COCs), containing a fixed dose of estrogen and progestogen, biphasic and triphasic COCs were introduced in the 1980s; in these the dose of ethinyl estradiol and progestogen changes during the pill cycle. In the so-called every day pills, the 21 pills of active steroid combination are followed by 7 inactive pills containing starch, iron, or bran. Method failures of OCs are among the lowest ranging from 0.2-1/100 woman-years. User failures can be as high as 6.2/100 women-years. The individual difference in peak plasma levels of estrogens in women taking identical OCs can be 10-fold. Conditions that affect the bioavailability of contraceptive steroids are: 1) drug interaction (vitamin C, drugs that induce liver enzymes, and antibiotics); 2) vomiting; 3) vegetarianism; 4) missing pills; and 5) malabsorption. Metabolic effects of COCs pertain to carbohydrate metabolism, lipid metabolism, hemostasis, and vitamins. Prescribing of COCs involves counseling clients about contraindications to COCs, starting routines, and the pill-free interval, as well as follow-up and monitoring, the problem of missing pills, and selection criteria for OC use. Medical conditions in which COC use requires special consideration are sickle cell disease, trophoblastic disease, HIV disease, gallstones, epilepsy, valvular heart disease, oligomenorrhea/amenorrhea, inflammatory bowel disease, and surgery. Side effects of COCs may include depression, nausea, vomiting, headaches, urinary tract infection, and lower genital tract infections. 6 months after stopping the OC 1% of users become amenorrheic. Many of the common causes of amenorrhea, such as weight loss amenorrhea and polycystic ovarian disease, may be treated with the COC until the couple desires to have a baby. The new progestogens desogestrel, norgestimate, and gestodene are highly selective compared to first and second generation progestogens.
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PMID:Combined oral contraceptives: acceptability and effective use. 832 4

We have recently shown that ascorbic acid (AA) suppresses the production of HIV in a latently infected T-lymphocytic cell line (ACH-2) following stimulation with the tumor promoter, PMA. To evaluate the effect of ascorbic acid on virus activation following treatment with inflammatory cytokine, we tested tumor necrosis factor alpha (TNF-alpha) whose levels are elevated in patients with HIV/AIDS. ACH-2 cultures, pretreated with various nontoxic concentrations of ascorbate or AZT were stimulated for 2 h with TNF-alpha, and incubated further with fresh supplements of ascorbate or AZT. At 24 to 48 h post-treatment, the RT activity released into culture supernatant was determined. Results showed that TNF-alpha alone caused approximately 13- to 16-fold stimulation in the level of extracellular RT. Pretreatment with ascorbic acid at 200 micrograms/ml caused a little more than about 2- to 4-fold reduction in extracellular RT levels. Most remarkably, exposure to 300 micrograms/ml ascorbate resulted in approximately 5- to 10-fold lowering of the extra-cellular RT titer. In contrast, no significant suppression in extracellular RT levels was seen with concentrations of AZT in the range of 1-5 micrograms/ml.
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PMID:Ascorbate effect on cytokine stimulation of HIV production. 874 52


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