Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Proinflammatory cytokines, tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma and interleukin (IL)-6, have multiple effects in the central nervous system (CNS) not strictly cytotoxic being involved in controlling neuronal and glial activation, proliferation, differentiation and survival, thus influencing neuronal and glial plasticity, degeneration as well as development and regeneration of the nervous system. Moreover, they can contribute to CNS disorders, including multiple sclerosis. Alzheimer's disease and human immunodeficiency virus-associated dementia complex. Recent results with deficient mice in the expression of those cytokines indicate that they are in general more sensible to insults resulting in neural damage. Some of the actions induced by TNF-alpha, and IFN-gamma, including both beneficial and detrimental, are mediated by inducible nitric oxide synthase (iNOS)-derived nitric oxide (NO) production. NO produced by iNOS may be beneficial by promoting the differentiation and survival of neurons. IL-6 does not induce iNOS, explaining why this cytokine is less often involved in this dual role protection pathology. Some of the proinflammatory as well as the neurotrophic effects of those cytokines also involve upregulation of cell adhesion molecules (CAM). Those apparently conflicting results may be reconciled considering that proinflammatory cytokines are involved in promoting the disease, mostly by inducing expression of CAM leading to alteration of the blood-brain barrier integrity, whereas they have a protective role once disease is established due to its immunosuppressive or neurotrophic role. Understanding the dichotomy pathogenesis/neuroprotection of those cytokines may provide a rationale for better therapeutic strategies.
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PMID:The role of tumour necrosis factor, interleukin 6, interferon-gamma and inducible nitric oxide synthase in the development and pathology of the nervous system. 977 Feb 42

A human immunodeficiency virus type 1 (HIV)-seropositive, antiretroviral-naive patient presented with significant cognitive dysfunction. Neuropsychologic, neuroradiologic, immunologic, and virologic studies confirmed HIV-associated dementia (HAD). After 12 weeks of highly active antiretroviral therapy (HAART) with ibuprofen, dramatic improvements were demonstrated in neurologic function and were sustained for > 1 year. HIV-1 RNA in cerebrospinal fluid (CSF) decreased from 10(5) to 10(4) copies/mL after 4 weeks. After 20 weeks of therapy, plasma viremia decreased from 10(6) copies/mL to undetectable (< 96 copies/mL). Assays of neurotoxins (tumor necrosis factor-alpha, quinolinic acid, and nitric oxide) in plasma and CSF were considerably elevated at presentation and significantly decreased after therapy. Baseline plasma and CSF demonstrated neurotoxic activities in vitro, which also reduced markedly. These data, taken together, support the notion that HAD is a reversible metabolic encephalopathy fueled by viral replication. HAART used with nonsteroidal antiinflammatory agents leads to the suppression of inflammatory neurotoxins and can markedly improve neurologic function in HAD.
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PMID:Suppression of inflammatory neurotoxins by highly active antiretroviral therapy in human immunodeficiency virus-associated dementia. 980 27

Nitric oxide (NO) plays an important role in normal neural cell function. Dysregulated or overexpression of NO contributes to neurologic damage associated with various pathologies, including human immunodeficiency virus (HIV)-associated neurological disease. Previous studies suggest that HIV-infected monocyte-derived macrophages (MDM) produce low levels of NO in vitro and that inducible nitric oxide synthase (iNOS) is expressed in the brain of patients with neurologic disease. However, the levels of NO could not account for the degree of neural toxicity observed. In this study, we found that induction of iNOS with concomitant production of NO occurred in primary human astrocytes, but not in MDM, when astrocytes were cocultured with HIV-1-infected MDM. This coincided with decreased HIV replication in infected MDM. Supernatants from cocultures of infected MDM and astrocytes also stimulated iNOS/NO expression in astrocytes, but cytokines known to induce iNOS expression (interferon-gamma, interleukin-1beta, and tumor necrosis factor-alpha) were not detected. In addition, the recombinant HIV-1 envelope protein gp41, but not rgp120, induced iNOS in cocultures of uninfected MDM and astrocytes. This suggests that astrocytes may be an important source of NO production due to dysregulated iNOS expression and may constitute one arm of the host response resulting in suppression of HIV-1 replication in the brain. It also leads us to speculate that neurologic damage observed in HIV disease may ensue from prolonged, high level production of NO.
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PMID:Human immunodeficiency virus-1-infected macrophages induce inducible nitric oxide synthase and nitric oxide (NO) production in astrocytes: astrocytic NO as a possible mediator of neural damage in acquired immunodeficiency syndrome. 1006 56

In the present study 220 patients suffering from recurrent rhinosinusitis and not responding to antibiotic treatment were evaluated for a defect in IgG-immunoglobulin subclasses. Twenty-one of these patients were found to have an antibody deficiency. These included deficiencies of IgG-2 (n = 10), IgG-1 (n = 6), IgG-3 (n = 1) and IgG-4 (n = 1). A common variable immune disease was diagnosed in three patients that was characterized by an additional defect in the IgG main class. However, an IgG subclass deficiency can only be ascertained by an immunological evaluation. The significance of a deficiency can be identified by a reaction to vaccination using (for example) protein or polysaccharide antigens. Treatment consists of antibiotics, intravenous immunoglobulins and long-term follow-up. Endonasal microsurgery should only be performed in cases that do not respond to conservative treatment. It is particularly necessary to observe these patients because a deficiency of immunoglobulin subclass in certain cases is the first sign of an immunological impairment that can advance to a severe immunodeficiency and predispose to the development of malignancy.
HNO 1999 Jan
PMID:[Immunoglobulin subclass defects in patients with therapy refractor chronic rhinosinusitis]. 1009 85

To rehabilitate most cases of conductive hearing loss closure of ear drum perforations and rebuilding of the ossicular chain can be performed. Due to the great number of biocompatible bone substitute materials available it is occasionally difficult for the surgeon to choose the most favorable substitute. Autogenous structures (ossicles, cortical bone, cartilage) and allogenous tissues (ossicles, cortical bone, cartilage, dentin) are possible bone replacement materials. Xenogenic tissue is currently not used in middle ear surgery. Ionomer cement is a hybrid material for replacement of bone but does not fit direct classification of the various classes of alloplastic materials in current use: that is, metals (gold, steel wire, platinum, titanium), plastics (polyethylene, polytetrafluorethylene) and ceramics (ceramic oxide, carbon, calcium-phosphate ceramic, vitreous ceramic). For restoration of the sound conductive apparatus preference is given to autogenous ossicles because cortical bone is resorbed and cartilage weakens over time. Most surgeons do not use allogenous tissue, because of the possible transmission of such infectious disease as immunodeficiency syndrome or Creutzfeldt-Jakob disease. Only dentin deserves special attention as a possible bone substitute in the middle ear because its form can be preserved during sterilization. Based on the observations available to date, it becomes apparent that titanium implants hold greater promise than gold. Form-stable synthetic materials are not generally recommended due to foreign body reactions which have been confirmed by many investigators. Ceramic materials (e.g. ceramic oxide, carbon, calcium-phosphate ceramic, glass ceramic) are well tolerated in the middle ear and have also proved to be useful over time. Hybrid bone substitute ionomer cement is easily workable and well integrated, showing a good functional outcome. For many years good results in otosclerosis surgery have been achieved with a prosthesis made of platinum-wire and Teflon. Short-term follow-up periods hold great promise with pistons made of gold. Autogenous ossicles, ionomer cement and recently titanium protheses--as far as usable--are employed by the author for reconstructing the middle ear. For the time being platinum-Teflon prostheses and gold are used in otosclerosis surgery.
HNO 1999 Feb
PMID:[Materials for reconstruction of the middle ear]. 1019 73

There has long been a popular conceptual linkage between human immunodeficiency virus (HIV) acquisition and substance abuse involving "needles". Indeed, in vitro studies demonstrate that these substances promote the replication of HIV. Included in these in vitro studies is a linkage or association of tissue damage and viral load with the actions HIV envelope protein gp120 with substances of abuse. However, detailed epidemiological studies have not supported this association of substance abuse and HIV acquisition, viral load and exacerbated tissue damage. It is with this understanding that we undertake a reevaluation of the in vitro studies within the context of the microvascular immune environment. In this regard, a counter-intuitive hypothesis emerges, namely, that specific substances of abuse may afford a degree of protection from HIV infection. This new hypothesis involves the neural, immune, and vascular signaling molecule nitric oxide.
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PMID:Substance abuse and HIV-gp120: are opiates protective? 1020 62

To evaluate the roles of nitric oxide (NO) on human immunodeficiency virus (HIV) Tat-induced transactivation of HIV long terminal repeat (HIV-LTR), we examined the effect of NO in the regulation of nuclear factor (NF)-kappaB, a key transcription factor involved in HIV gene expression and viral replication. In the present study, we demonstrate that HIV Tat activates NF-kappaB and that this activation can be attenuated by endogenous or exogenous NO. Inhibition of endogenous NO production with the NO synthase (NOS) inhibitor L-NMMA causes a significant increase in Tat-induced NF-kappaB activity. In addition, NO attenuates signal-initiated degradation of IkappaBalpha, an intracellular inhibitor of NF-kappaB, and blocks the DNA binding activity of the NF-kappaB p50/p50 homodimer and p50/p65 heterodimer. To determine how NO is induced by HIV Tat, reverse transcription polymerase chain reaction was used to demonstrate the induction of NOS-2 and NOS-3 mRNA by Tat. Although a putative NF-kappaB binding site was identified in the -74 GGAGAGCCCCC -64 region of the NOS-3 gene promoter, gel mobility shift assays and site-directed mutation analyses suggest that the putative NF-kappaB site is not of primary importance. Rather, several Sp-1 sites adjoining the putative NF-kappaB binding site in the promoter region of NOS-3 gene are required for the induction of NOS-3 gene expression by Tat.
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PMID:Nitric oxide inhibits HIV tat-induced NF-kappaB activation. 1039 59

Effects of dietary protein or arginine deficiency on constitutive and lipopolysaccharide (LPS)-induced nitric oxide (NO) synthesis were determined in young rats by quantifying urinary nitrate excretion. In Experiment 1, 30-d-old rats (n = 16) were divided randomly into two groups (n = 8/group) and pair-fed on the basis of body weight semipurified isocaloric diets containing 20 or 5% casein. In Experiment 2, 30-d-old rats (n = 24) were divided randomly into three groups (n = 8) and pair-fed on the basis of body weight purified isonitrogenous and isocaloric diets (composed of amino acids) containing 0.0, 0.3 or 1.0% L-arginine. In both experiments, daily collection of urine was initiated 10 d after the start of pair-feeding. On d 17 after the pair-feeding was initiated, LPS (1 mg/kg body wt) was injected intraperitoneally into rats, and urine was collected daily for an additional 7 d. In Experiments 3 and 4, activities of constitutive and inducible NO synthases were measured in macrophages and various tissues from protein- or arginine-deficient rats (n = 6). Body weight was lower in rats fed the 5% casein diet or the 0.0 and 0.3% arginine diets than in those fed 20% casein or 1% arginine, respectively. Dietary protein or arginine deficiency decreased serum concentrations of arginine and urinary nitrate excretion before and after LPS treatment, indicating impaired constitutive and inducible NO synthesis. Protein malnutrition reduced constitutive and inducible NO synthase activities in brain, heart, jejunum, lung, skeletal muscle and spleen, and inducible NO synthase activity in macrophages. Because NO is a mediator of the immune response and is the endothelium-dependent relaxing factor, impaired NO synthesis may help explain immunodeficiency and cardiovascular dysfunction in protein- or arginine-deficient subjects.
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PMID:Dietary protein or arginine deficiency impairs constitutive and inducible nitric oxide synthesis by young rats. 1039 97

In order to establish whether the neurotoxicity of the human immunodeficiency virus type 1 (HIV-1) regulatory protein Tat could be related to the production of potentially toxic substances by microglial cells, we examined the ability of recombinant HIV-1 Tat protein to stimulate the release of NO in purified rat microglial cultures. We found that the exposure of microglia to Tat led to a dose dependent expression of the inducible isoform of nitric oxide (iNOS) and NO production. The effect was remarkably enhanced by pretreatment or cotreatment with the proinflammatory cytokine interferon-gamma (IFN-gamma), but not with bacterial lipopolysaccharide (LPS). The high concentrations of Tat required (>100 ng/ml) suggested the viral protein induced transactivation of the iNOS gene, rather than acting through a receptor-mediated mechanism, that generally requires lower concentrations. Indeed, the induction of the iNOS gene by Tat was largely prevented by a specific inhibitor of the nuclear factor-kB (NF-kB), a transcription factor known to be involved in the induction of iNOS by LPS. The activation of NF-kB could largely account for the ability of Tat to induce iNOS expression and to act in synergism with IFN-gamma, which utilizes a different transduction system. On the other hand, the convergence of Tat and LPS on the same target (NF-kB) could explain the lack of synergism between these substances. We propose that the induction of iNOS in microglial cells and the consequent release of high and sustained levels of NO during HIV-1 cerebral infection may be an important step in the cascade of pathological events triggered by Tat. Furthermore, the NO-dependent damage may be exacerbated by the presence of IFN-gamma, which is likely to occur in pathological conditions characterized by glial activation and inflammatory cell infiltration.
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PMID:Human immunodeficiency virus type 1 Tat protein stimulates inducible nitric oxide synthase expression and nitric oxide production in microglial cultures. 1044 7

In infected human cells, nitric oxide (NO) has been shown to inhibit the replication of the human immunodeficiency virus-1 (HIV-1), the etiological agent of AIDS. Evidence suggests that NO may regulate HIV-1 replication by affecting the sulphydryl redox state. In this respect, it has been very recently demonstrated that NO-donors inactivate the HIV-1-encoded protease and reverse transcriptase in vitro. Further viral and host NO targets may be envisaged. Although no data are available on the anti-HIV-1 effect of NO in vivo, NO-releasing drugs, clinically used in the treatment of cardiovascular disorders, may represent a novel class of molecules for decreasing virus replication. Here, the possible molecular bases for the anti-HIV-1 effect of NO are discussed.
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PMID:Molecular bases for the anti-HIV-1 effect of NO. Commentary. 1049 76


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