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

HIV infection has profound effects on a patient's nutritional status because it can modulate appetite, nutrient absorption and basal metabolic rate. In addition, HIV infection can lead to the depletion of a variety of vitamins and micronutrients including vitamins A, D, B2, B6, B12, L-carnitine, iron, zinc and selenium. This review article summarizes existing data regarding nutritional defects in HIV-infected patients and the results of clinical studies addressing the effects of nutritional supplementation in infected patients.
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PMID:Nutrition and HIV infection in children. 1083 30

In tropical zones, uncertain living conditions, inadequate food intake, and poor medical facilities enhance unnecessary morbidity and mortality especially involving infants and young children. In addition to protein-caloric malnutrition, deficiencies in essential micronutrients have a specific health impact. Such deficiencies can be the direct cause of disease such as vitamin A deficiency and blindness or have a promoting effect by compromising immune status and increasing susceptibility to and severity of infectious diseases especially of viral origin. The promoting effect of micronutrient deficiency plays a significant role in measles, rotavirus-related diarrhea, and, to a certain extent, progression of HIV infection. Several examples are described to illustrate the relationship between tropical viral infection and micronutrients including vitamin A, selenium, and various other antioxidants. These examples highlight the effect of infectious disease on micronutritional status (vitamin A and measles) and the need to develop reliable, practical tools to evaluate the relevance and effectiveness of dietary supplementation. In any case, improving living conditions and health programs such as the Expanded Vaccination Program are required and illustrate a transverse approach for prevention of infectious and non-infectious tropical disease. The relationship between micronutrients and infection is only one aspect of the multifactorial reality that must be dealt with in tropical medicine.
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PMID:[Micronutrients and tropical viral infections: one aspect of pathogenic complexity in tropical medicine]. 1090 45

An important role for selenium in human immunodeficiency virus (HIV) disease has been proposed. Decreased selenium levels, as found in persons with HIV infection or AIDS, are sensitive markers of disease progression. Selenium deficiency, an independent predictor of mortality in both HIV-1-infected adults and children, is an essential micronutrient that is associated with an improvement of T cell function and reduced apoptosis in animal models. In addition, adequate selenium may enhance resistance to infections through modulation of interleukin (IL) production and subsequently the Th1/Th2 response. Selenium supplementation up-regulates IL-2 and increases activation, proliferation, differentiation, and programmed cell death of T helper cells. Moreover, selenium supplementation may down-regulate the abnormally high levels of IL-8 and tumor necrosis factor-alpha observed in HIV disease, which has been associated with neurologic damage, Kaposi's sarcoma, wasting syndrome, and increased viral replication. Together, these findings suggest a new mechanism through which selenium may affect HIV-1 disease progression.
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PMID:Selenium and interleukins in persons infected with human immunodeficiency virus type 1. 1094 86

The essential trace mineral, selenium, is of fundamental importance to human health. As a constituent of selenoproteins, selenium has structural and enzymic roles, in the latter context being best-known as an antioxidant and catalyst for the production of active thyroid hormone. Selenium is needed for the proper functioning of the immune system, and appears to be a key nutrient in counteracting the development of virulence and inhibiting HIV progression to AIDS. It is required for sperm motility and may reduce the risk of miscarriage. Deficiency has been linked to adverse mood states. Findings have been equivocal in linking selenium to cardiovascular disease risk although other conditions involving oxidative stress and inflammation have shown benefits of a higher selenium status. An elevated selenium intake may be associated with reduced cancer risk. Large clinical trials are now planned to confirm or refute this hypothesis. In the context of these health effects, low or diminishing selenium status in some parts of the world, notably in some European countries, is giving cause for concern.
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PMID:The importance of selenium to human health. 1103 24

As dioxolane and oxathiolane nucleosides have exhibited promising antiviral and anticancer activities, it was of interest to synthesize isoelectronically substituted oxaselenolane nucleosides, in which the 3'-CH(2) is replaced by a selenium atom. To study structure-activity relationships, various pyrimidine and purine oxaselenolane nucleosides were synthesized from the key intermediate, (+/-)-2-benzoyloxymethyl-1,2-oxaselenolane 5-acetate (6). Among the synthesized racemic nucleosides, cytosine and 5-fluorocytosine analogues exhibited potent anti-HIV and anti-HBV activities. It was of interest to obtain the enantiomerically pure isomers to determine if they have differential antiviral activities. However, due to the difficult and time-consuming nature of enantiomeric synthesis, a chiral HPLC separation was performed to obtain optical isomers from the corresponding racemic mixtures. Each pair of enantiomers of Se-ddC and Se-FddC was separated by an amylose chiral column using a mobile phase of 100% 2-propanol. The results indicate that most of the anti-HIV activity of both cytosine and fluorocytosine nucleosides resides with the (-)-isomers.
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PMID:Synthesis and antiviral activity of oxaselenolane nucleosides. 1105 95

Nutritional deficiencies are widespread among HIV-1-seropositive male and female drug abusers (injecting drug users, or IDUs), among men who have sex with men (MSM), and among children, although the prevalence of nutritional alterations varies among the groups. Low levels of vitamin A, vitamin B12, zinc, and selenium are common and have been demonstrated to be associated with disease progression and HIV-1 related mortality, independent of CD4 count <200 cells/mm3 at baseline and CD4 count over time. When all nutrient factors that are associated with survival are considered together, only selenium deficiency is a significant predictor of mortality. The profound effect of selenium on disease progression may reflect selenium's action in antioxidant defense systems, as well as gene regulation.
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PMID:Role of micronutrients in HIV-infected intravenous drug users. 1112 27

HIV-infected injection drug users (IDUs) often suffer from serious nutritional deficiencies. This is a concern because plasma levels of micronutrients such as vitamin B12, zinc, and selenium have been correlated with mortality risk in HIV-positive populations. Injection drug use also increases lipid peroxidation and other indicators of oxidative stress, which, combined with antioxidant deficiencies, can stimulate HIV-1 replication through activation of NF-kappaB transcription factors, while weakening immune defenses. As detailed herein, these prooxidant stimuli can also increase the pathogenic effects of HIV-1 by another mechanism, involving viral selenoproteins. Overlapping the envelope coding region, HIV-1 encodes a truncated glutathione peroxidase (GPx) gene (see #6 in reference list). Sequence analysis and molecular modeling show that this viral GPx (vGPx) module has highly significant structural similarity to known mammalian GPx, with conservation of the catalytic triad of selenocysteine (Sec), glutamine, and tryptophan. In addition to other functions, HIV-1 vGPx may serve as a negative regulator of proviral transcription, by acting as an NF-kappaB inhibitor (a known property of cellular GPx). Another potential selenoprotein coding function of HIV-1 is associated with the 3' end of the nef gene, which terminates in a conserved UGA (potential Sec) codon in the context of a sequence (Cys-Sec) identical to the C-terminal redox center of thioredoxin reductase, another cellular regulator of NF-kappaB. Thus, in combination with known cellular mechanisms involving Se, viral selenoproteins may represent a unique mechanism by which HIV-1 monitors and exploits an essential micronutrient to optimize its replication relative to the host.
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PMID:Nutrition, HIV, and drug abuse: the molecular basis of a unique role for selenium. 1112 28

Transmission of HIV from mothers to children may occur through the transplacental, intrapartum, or breastfeeding routes. Adequate nutritional status may reduce vertical transmission by affecting several maternal or fetal and child risk factors for transmission including enhancing systemic immune function in the mother or fetus/child; reducing the rate of clinical, immunological, or virological progression in the mother; reducing viral load or the risk of viral shedding in lower genital secretions or breast milk; reducing the risks of low birth weight or prematurity; or by maintaining the integrity of the fetus/child gastrointestinal integrity. In prospective observational studies, low plasma vitamin A levels were associated with higher risks of vertical transmission. However, findings from randomized, controlled trials suggest that supplements of vitamin A or other vitamins are unlikely to have an effect on vertical transmission during pregnancy or the intrapartum period. The effect of other nutrient supplements, such as zinc and selenium, is unknown. Similarly, whether nutrition supplements of mothers during the breastfeeding period has an effect on transmission is unknown. The potential benefits of direct supplementation of children born to HIV-infected women on transmission of HIV, as well as on the risk and severity of childhood infections and mortality, are also important to examine.
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PMID:Nutritional factors and vertical transmission of HIV-1. Epidemiology and potential mechanisms. 1113 40

Various vitamins and minerals play roles in HIV infection. There is evidence that a number of HIV+ patients suffer from deficiencies in vitamins B12, B6, A, and D; folate, zinc and selenium; and carotenoids such as beta-carotene, betacryptoxanthin, and lutein. Vitamin B12 deficiency can result in peripheral neuropathy, encephalopathy, cognitive dysfunction and anemia. Lowered levels of vitamins B6 and A can lead to impaired immune function and, in the latter, an increased rate of perinatal transmission. Low levels of vitamin D have been linked to weight loss and wasting. Folate deficiencies are related to anemia, and low levels of zinc and/or selenium have been linked to impaired immune function. Information on the carotenoids, which have been found to be associated with cellular immune function, is mostly derived from recent research. Studies have shown that the levels of carotenoids are decreased in HIV+ people even in the early stages of infection, but the greatest deficiencies appeared in patients with the most advanced disease. Other clinical trials seem to indicate that administration of beta-carotene improves immune function, causing an increase in CD4 counts over baseline levels. Clinical trials conducted in response to all of these deficiencies have found multivitamin supplementation to be beneficial. Therefore, it is recommended that all HIV-infected patients receive a multivitamin supplement to assist in reversing the damage caused by these vitamin and mineral deficiencies.
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PMID:Update on vitamins, minerals, and the carotenoids. 1136 98

Nutritional status directly affects immune competence; therefore, dietary supplements can be beneficial. Vitamin A, a fat-soluble nutrient obtained exogenously from animal protein or synthesized endogenously from carotenoids, is important in vision, epithelial tissue maintenance, reproduction, and growth. It is also an antioxidant, and can interfere with HIV-related oxidative destruction. Vitamin C, a water-soluble antioxidant important in hydroxylation reactions and required by erythrocytes for retrieving stored iron, can suppress HIV in vitro. However, this requires long-term administration, and its effect ceases upon termination of treatment. Vitamin E, fat-soluble tocopherols, can be found in plants, vegetable oils, milk, eggs, fish, meats, and cereals. A potent antioxidant because of its electron-donating ability, vitamin E reduces HIV replication. Deficiency reduces inhibition of tumor necrosis factor alpha (TNF-a) and protein kinase C, therefore limiting immunocompetence. Additionally, damaging side effects of AZT, normally reversed or minimized by vitamin E, may induce low leukocyte counts and anemia. Vitamin E acts synergistically with selenium, another antioxidant, to block the rate of lipid peroxidation. Its administration may reduce diarrhea, cramping, and weight loss, and may improve epithelial conditions and reduce the frequency of illness. N-acetylcysteine (NAC), a sulfur-containing amino acid, inhibits HIV replication by raising serum glutathione levels through inhibition of TNF-a. Finally, HIV-infected patients should consider gluten-free diets during times of acute gastric distress.
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PMID:Nutrition and HIV. 1136 99


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