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

Reactive oxygen species (ROS) may play an important role in HIV-1 pathogenesis and HIV-1 gp120-induced neurotoxicity. Our studies determined the extent to which gp120 increased ROS production in human monocytic U937 cells and the effectiveness of various agents, including dipyridamole (DPR), in blocking these responses. The thiobarbituric acid-reactive substances (TBARS) assay was used as a measure of recombinant gp120 (HIV-1[3B])-induced oxidative damage to U937 cells. As a control, TBARS production was measured using a hypoxanthine/xanthine superoxide generating system. There was gp120-induced oxidative damage in U937 cells with a concentration that produces 50% of maximal effect (apparent EC50 value) of 11 pM. Polyclonal antiserum to gp120 significantly (p < 0.05) inhibited gp120-induced oxidative damage. gp120-induced oxidative damage was significantly inhibited 81% (p < 0.01) by catalase/superoxide dismutase, 53% (p < 0.05) by (+/-)-alpha-tocopherol, 78% (p < 0.01) by desferrioxamine, and 82% (p < 0.01) by ethylene diamine tetraacetic acid (EDTA). These results indicate that gp120 is capable of promoting iron-based oxygen free radical damage to U937 cells. DPR potently (p < 0.05) inhibited both hypoxanthine/xanthine- and gp120-induced oxidative damage with concentrations that produce 50% inhibition (apparent IC50 values) of 1.3 microM for hypoxanthine/xanthine and 1.0 microM for gp120. Therapeutic intervention against ROS production may prevent HIV-1 neurotoxicity.
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PMID:Antioxidants and dipyridamole inhibit HIV-1 gp120-induced free radical-based oxidative damage to human monocytoid cells. 940 67

Brain iron deposition was assessed at 1.5 T in the caudate nucleus, globus pallidus and frontal and parieto-occipital white matter in 28 human immunodeficiency virus (HIV)-infected patients and 15 control subjects with a new Partially Refocussed Interleaved Multi-Echo sequence by measuring 1/T2, 1/T2* and 1/T2' (i.e., R2, R2* and R2'). There were significant differences in the R2 and R2* of the caudate nucleus (p < 0.0001 and p < 0.05) and the R2, R2* and R2' of the globus pallidus (p < 0.01, p < 0.005 and p < 0.05) in HIV-infected patients compared to control subjects. There was a trend for higher values of R2, R2* and R2' in the globus pallidus and caudate nucleus in HIV-infected patients with later stage HIV disease. These results suggest that there is greater iron deposition in the basal ganglia of HIV-infected patients compared with control subjects, with a predilection for the globus pallidus. The relationship between iron deposition in the brain and various parameters of severity of HIV infection remains uncertain.
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PMID:The measurement of R2, R2* and R2' in HIV-infected patients using the prime sequence as a measure of brain iron deposition. 940 32

The anaemia that is a common complication of human immunodeficiency virus (HIV) infection bears many similarities to the anaemia of chronic disease. These similarities include an impaired erythropoietin (EPO) response to anaemia, reduced concentrations of marrow progenitors giving rise to erythroid colonies, abnormalities of reticuloendothelial iron metabolism, and correction of anaemia with recombinant human EPO. A model has been developed in which the pathophysiologic processes producing the anaemia of chronic disease may be attributed to actions of the cytokines that mediate the immune response, such as interleukin-1, tumor necrosis factor and the interferons. These cytokines are also implicated in HIV-related anaemia. In this review, the applicability of this cytokine-mediated anaemia model to the anaemia of HIV infection is explored.
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PMID:Cytokines and anaemia in human immunodeficiency virus infection. 942 76

Anemia occurs frequently among patients seropositive for human immunodeficiency virus (HIV), but its multifactorial origin complicates its differential diagnosis and adequate treatment. In addition, the etiology of anemia in HIV infection often remains unclear. In recent years several attempts have been undertaken to elucidate the mechanisms leading to HIV-associated anemia. Direct infection of erythroid progenitors has been discussed, but could not be proven. Furthermore, soluble factors like HIV proteins and cytokines have been suggested to inhibit growth of hematopietic cells in the bone marrow of HIV-infected patients. However, so far no statements can be made whether these factors are directly involved in myelosuppression or mediate their effect by inhibiting growth-factor synthesis. Opportunistic complications represent the underlying cause for anemia in a large number of HIV-infected patients. Next to this rather obvious reason for anemia, iatrogenic anemia induced by myelosuppressive drugs is also very common. It is of note, however, that modern dosages of < 600 mg zidovudine (ZDV) daily rarely cause anemia. Instead, other drugs that can induce anemia itself or by enhancing ZDV plasma concentrations must be considered important contributing factors. Deficiency of vitamin B12, folate and iron are frequently reported in HIV patients. However, specific investigations revealed appropriate storage amounts of these micronutrients. Supplementation may be beneficial in some patients, but often fails to reverse anemia in this population. In anemic HIV patients reticulocytopenia is a consistent finding. Additionally, inadequately low endogenous erythropoietin concentrations have been repeatedly reported. Thus, it is speculated that a blunted erythropoietin feedback mechanism contributes substantially to the pathogenesis of anemia in HIV patients.
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PMID:Pathogenesis and pathophysiology of anemia in HIV infection. 943 73

Excessive production of oxygen free radicals causes the oxidation of circulating or membrane lipids, proteins, and DNA. Patients infected with HIV usually have severe malnutrition in the AIDS stage of disease. Therefore, they may be at higher risk of oxidative stress. We measured lipid hydroperoxide concentration, antioxidant status, cholesterol, triglyceride, iron, ceruloplasmin, and transferrin concentrations in the serum samples of 14 patients infected with HIV and compared our results with the results from 14 volunteers who served as controls. Lipid hydroperoxide concentrations in serum samples were measured by a colorimetric assay in which hemoglobin catalyzes the reaction of lipid hydroperoxide with a methylene blue derivative, yielding methylene blue. The total antioxidant capacity of serum was measured by the ability of serum to inhibit the formation of ferrylmyoglobin by metmyoglobin and hydrogen peroxide. Both assays were automated on the Syva-30R analyzer (Behring, San Francisco, Calif). We measured serum cholesterol and triglyceride concentrations by using the Vitro 950 analyzer (Johnson & Johnson, Rochester, NY). The lipid hydroperoxide concentrations were significantly elevated (mean, 1.44; SD, 0.95 micromol/L) in patients with HIV compared with control subjects (mean, 0.25; SD, 0.24 micromol/L). In contrast, the total antioxidant capacity was significantly lower in patients with HIV (mean, 1.04; SD, 0.13 mmol/L of trolox equivalent) compared with control subjects (mean, 1.66; SD, 0.09 mmol/L). We observed a fair correlation between serum lipid hydroperoxide concentrations and serum triglyceride concentrations in patients with AIDS. The correlation between serum hydroperoxide concentration and antioxidant status of serum was relatively poor. The lipid hydroperoxide assay was linear, from 0.1 micromol/L to 50 micromol/L. The within-run and between-run coefficients of variation were 3.5% and 4.5%, respectively, at a lipid hydroperoxide concentration of 2.5 micromol/L. The total antioxidant capacity assay was linear, from 0.1 to 2.5 mmol/L of trolox equivalent. The within-run and between-run coefficients of variation were 1.4% and 4.2% for the standard, with a target total antioxidant capacity of 1.5 mmol/L of trolox equivalent. We conclude that our automated assays for determination of total antioxidant status of serum and lipid hydroperoxide products may be helpful screening tests followed by measuring individual antioxidants, such as tocopherol, ascorbic acid, and other antioxidants for patients with severe deficiency of antioxidant status.
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PMID:Rapid automated determination of lipid hydroperoxide concentrations and total antioxidant status of serum samples from patients infected with HIV: elevated lipid hydroperoxide concentrations and depleted total antioxidant capacity of serum samples. 949 97

Recombinant human erythropoietin is used in clinical practice mainly for treatment of anemia of renal failure. In the past years, however, its use has been approved for other indications, including prevention of anemia in surgical patients or in patients undergoing platinum-based chemotherapy, treatment of anemia of prematurity, of anemia induced by zidovudine therapy in HIV-infected patients, and of anemia induced by chemotherapy of nonmyeloid malignancies. Erythropoietin should routinely be given subcutaneously to maximize its effects. Most patients undergoing rHuEpo treatment develop functional iron deficiency, a situation in which iron supply to the erythroid marrow is inadequate for the erythrocyte precursor demand. Iron supplementation should, therefore, be given to all individuals receiving rHuEpo except for those patients with increased serum iron and transferrin saturation. Outside the setting of uremia, only a portion of patients can clearly benefit from erythropoietin therapy; therefore, the use of rHuEpo should be individualized in nonrenal applications.
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PMID:How and when to use erythropoietin. 957 Jul 2

An ongoing (1994-98) randomized, community-based trial in Uganda's Rakai District is assessing the assumption that intensive sexually transmitted disease (STD) control efforts result in marked declines in HIV/AIDS prevalence. Described, in this article, are the project design and findings of the first-round baseline survey. 56 communities were grouped into 10 clusters designed to encompass social/sexual networks and clusters within blocks were randomly assigned to the intervention or control arm. All consenting permanent residents of the district are visited in their homes at 10-month intervals where they are administered extensive questionnaires, provide urine and vaginal swab samples, and are offered mass treatment regardless of symptoms or laboratory testing (single oral dose STD treatment in the intervention arm and anthelmintics and iron folate in the control arm). Both groups receive identical health education, condom promotion, and serologic counseling services. In the first round of home visits, 5834 intervention and 5784 control arm subjects were enrolled, representing about 90% of eligible adults. The groups were comparable in terms of sociodemographic and behavioral characteristics and baseline rates of HIV and STDs. 16.9% of subjects were HIV-positive, 10.0% had syphilis, 23.8% of women had trichomonas, and 50.9% had bacterial vaginosis. Detailed STD assessment is expected not only to document the relationship between STD control and HIV, but also to identify which STDs confer the greatest population attributable risk for HIV transmission, facilitating targeted control efforts in the future.
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PMID:A randomized, community trial of intensive sexually transmitted disease control for AIDS prevention, Rakai, Uganda. 967 71

Mycobacterium haemophilum has recently been recognized as a newly emerging cause of osteomyelitis in immunocompromised patients. While still uncommon, its incidence has increased significantly with the growing AIDS epidemic. Like its relative M. tuberculosis and M. intracellulare, this organism is acid-fast positive; yet unlike its more well-known counterparts, M. haemophilum requires iron-supplemented culture media and low incubation temperatures (30-32 degrees C) for growth. We describe a case of M. haemophilum osteomyelities in the distal femur of a 36-year-old HIV-positive male, who also presented with multiple skin ulcerations. In an AIDS patient with a lytic bone lesion and concomitant skin eruptions, the diagnosis of M. haemophilum should be entertained so that special culture media can be used and appropriate treatment administered.
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PMID:Considering Mycobacterium haemophilum in the differential diagnosis for lytic bone lesions in AIDS patients who present with ulcerating skin lesions. 967 51

Economic deterioration and a decade of military rule have had a disastrous impact on the health of women and children in Burma. In 1996, Burma's infant mortality rate was 105/1000 live births. The major causes of child mortality and morbidity are intestinal and respiratory infections, malaria, malnutrition, and vaccine-preventable diseases. Low birth weight, iodine and vitamin A deficiency diseases, and iron-deficiency anemia are widespread. Cholera outbreaks occur each year. The Universal Child Immunization Program, supported by UNICEF, reaches less than 60% of eligible children. The maternal mortality rate is 580/100,000 live births; most are related to unsafe abortion. Basic reproductive health care is available only in select areas of the country. 17-22% of women use modern contraception. UNAIDS has estimated that 440,000 Burmese are HIV-infected and there are 14,000 AIDS orphans. HIV prevalence is 26.5% in urban prostitutes, 91% among injecting drug users near the Chinese border, and 10.6% among pregnant women in one border town. Any improvement in the health status of the population requires a shift in priority on the part of the military government from weapons build-up to health promotion and protection.
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PMID:Burma: a country's health in crisis. 977 77

Lactoferrin is a mammalian iron-binding glycoprotein present in many biological secretions, such as milk, tears, semen and plasma and a major component of the specific granules of polymorphonuclear leucocytes. The effect of bovine lactoferrin (BLf) in apo-form or saturated with ferric, manganese or zinc ions, on human immunodeficiency virus type 1 (HIV-1) infection in the C8166 T-cell line was studied. Both HIV-1 replication and syncytium formation were efficiently inhibited, in a dose-dependent manner, by lactoferrins. BLf in apo and saturated forms markedly inhibited HIV-1 replication when added prior to HIV infection or during the virus adsorption step, thus suggesting a mechanism of action on the HIV binding to or entry into C8166 cells. Likewise, the addition of Fe3+BLf prior to HIV infection and during the attachment step resulted in a marked reduction of the HIV-1 DNA in C8166 cells 20 h after infection. The potent antiviral effect and the high selectivity index exhibited by BLf suggest for this protein, in apo or saturated forms, an important role in inhibiting the early HIV-cell interaction, even though a post adsorption effect cannot be ruled out.
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PMID:Antiviral effect of bovine lactoferrin saturated with metal ions on early steps of human immunodeficiency virus type 1 infection. 978 69


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