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

Candida albicans and Cryptococcus neoformans are major causes of systemic fungal infections, particularly in patients with acquired immunodeficiency syndrome. Metabolic labeling studies revealed that these organisms synthesize a small number of N-myristoylproteins, the most prominent being 20-kDa ADP-ribosylation factors (Arfs). C. albicans Arf has approximately 80% identity with the essential Arf1 and Arf2 proteins of Saccharomyces cerevisiae. [3H]Myristic acid analogs with oxygen for -CH2- substitutions at C4, C6, C11, and C13 are incorporated into cellular N-myristoylproteins, phospholipids, and neutral lipids produced by these three yeasts during exponential growth at 30 degrees C in complex media. Analog- and organism-specific differences in the efficiency of labeling of proteins and lipid classes were observed. The effects of oxatetradecanoic acids with oxygen for -CH2- substitutions at C3-C13 on C. neoformans, C. albicans, and S. cerevisiae were assessed during mid-log phase growth at 30 degrees C. A single dose of 3-oxa-, 4-oxa-, 5-oxa- or 6-oxatetradecanoic acid (O3-O6, final concentration = 300 microM) was able to inhibit growth of C. neoformans in the order O4 greater than O5 greater than O3 approximately O6. The other compounds were inactive. 4-Oxatetradecanoic acid was fungicidal, producing a 10,000-fold reduction in viable cell number 1 h after administration and continued suppression of cell growth for 7 h. A clear dose response was observed over a concentration range of 100-300 microM. 4-Oxatridecanoic acid was 100-fold less potent in reducing cell viability than 4-oxatetradecanoic acid but more potent than 5-oxatridecanoic acid. O4 produced approximately 10-100-fold reductions in the viability of C. albicans and S. cerevisiae at 300-500 microM, respectively, whereas O5 and O6 were less active. Since N-myristoylation of the Pr55gag polyprotein precursor produced by human immunodeficiency virus I (HIV-I) is essential for its assembly, we also assessed the antiviral effects of 4-oxatetradecanoic acid. O4 is able to produce a 50% reduction in the replication of HIV-I in acutely infected human T-lymphocyte cell lines at a concentration of 18 microM. Together, these data suggest that (i) the position of the oxygen for methylene substitution is a critical determinant of the fungicidal activity of O4 and (ii) NMT may be an attractive therapeutic target for treating opportunistic fungal infections in patients infected with HIV-I.
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PMID:4-oxatetradecanoic acid is fungicidal for Cryptococcus neoformans and inhibits replication of human immunodeficiency virus I. 151 54

Purulent bronchitis was identified in 19 of 422 patients undergoing fiberoptic bronchoscopy during a 32-month period because of suspicion of an opportunistic lung infection complicating acquired immunodeficiency syndrome or human immunodeficiency virus infection. Five patients had Pneumocystis carinii pneumonia, but other opportunistic lung infections were excluded in the remaining 14 patients. Characteristics of these 14 patients included fever (greater than 38.3 degrees C), cough, and dyspnea in 14 of 14 patients; purulence of expectorated sputum (11/14); and widened alveolar-arterial oxygen gradient (13/14). Rapid (2 +/- 1.4 days) clinical response (defervescence and resolution of pulmonary symptoms) occurred with antibiotic therapy in 10 of 14 patients. In three patients, there was no improvement, and adult respiratory distress syndrome developed. Bacterial isolates from bronchoalveolar lavage included Streptococcus viridans (n = 12), Haemophilus influenzae (n = 7), Staphylococcus aureus (n = 3). Roentgenographic features of bronchiectasis were present in seven patients. Differential cell counts revealed greater than 50% neutrophils in the bronchial washings of all patients with purulent bronchitis. Neutrophil percentages in bronchoalveolar lavage were as follows: patient with purulent bronchitis without P carinii pneumonia (n = 14), 54.53% +/- 29.18%; patients with purulent bronchitis and concomitant P carinii pneumonia (n = 5), 62% +/- 31.9%. In a control group of 17 patients with P carinii pneumonia who did not have purulent bronchitis, the neutrophil percentage was 6.8% +/- 6.17% (p = less than 0.00001, t-test). Purulent bronchitis appears to be a distinct, treatable entity in patients with HIV infection and may accompany bacterial pneumonia, bronchiectasis, and P carinii pneumonia.
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PMID:Bronchitis mimicking opportunistic lung infection in patients with human immunodeficiency virus infection/AIDS. 151 86

Transfusion of red blood cells is useful in restoring oxygen-carrying capacity in patients with symptomatic anemia. In general, physicians should avoid transfusing blood based on hemoglobin concentration alone. Instead, they should focus on the impact of anemia on the patient's symptoms and level of activity. The concern for HIV infection and viral hepatitis has only served to highlight the potential risks associated with homologous transfusion therapy. These concerns should be carefully considered, along with possible alternatives, before a decision is made to transfuse. It is important to define the cause of anemia and to institute appropriate corrective therapy. The availability of recombinant human erythropoietin offers an option in selected patients to reduce or eliminate the need for red blood cell transfusion.
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PMID:Use of blood transfusion in management of anemia. 157 67

Seven patients with necrotizing soft tissue infections of the perineum are described. Predisposing factors related to infection were present in four patients (diabetes mellitus, multiple myeloma, HIV, and a poorly defined immunodeficiency syndrome). Anaerobic and facultative anaerobic bacteria were cultured in each case. Two patients required skin graft closure of the debrided wounds, with the remaining wounds closed by contracture and epithelialization. A diverting sigmoid colostomy to facilitate wound care was performed on one patient who had complete dissolution of all anal sphincters. The role of hyperbaric oxygen therapy in four patients was of uncertain value.
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PMID:Synergistic soft tissue infections of the perineum. 161 51

1. Certain metal ions have been identified as inhibitors (IC50 1-20 microM) of the aspartic proteinase of Human Immunodeficiency Virus Type 1 (HIV-PR). 2. By contrast most simple metal ions do not inhibit this enzyme. 3. Those that did inhibit have in common a high charge/size ratio or "hard" acidic nature, preferring to combine covalently with oxygen donor ligands. 4. Some evidence from independent X-ray crystal structure determinations suggests that the metalloinhibitors identified here may bind in the active site of the enzyme via coordination to the carboxylate side chains of the essential active site residues Asp 25 and 125. 5. Although the measured inhibition is only microM, very few enzyme-inhibitor interactions can be taking place and so more complex metalloinhibitors with ligands that can also bind to peptide side chains of the enzyme might be significantly more potent inhibitors of HIV-PR and of viral replication.
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PMID:Inhibition of HIV-1 proteinase by metal ions. 161 81

Dupuytren's contracture is a deforming, fibrotic condition of the palmar fascia which has confounded clinicians and scientists since the early descriptions by Guillaume Dupuytren in 1831. It predominantly affects elderly, male caucasians, has a hereditary predisposition and has strong associations with diabetes, alcohol consumption, cigarette smoking and HIV infection. The major morphological features are an increase in fibroblasts, particularly around narrowed fibroblasts; a finding consistent with localised ischaemia. During ischaemia, adenosine triphosphate (ATP) is converted to hypoxanthine and xanthine, and endothelial xanthine dehydrogenase to xanthine oxidase (alcohol also mediates this change, a finding of particular relevance given the association of Dupuytren's contracture with alcohol intake). Xanthine oxidase catalyses the oxidation of hypoxanthine to xanthine and uric acid with the release of superoxide free radicals (O2-), hydrogen peroxide (H2O2) and hydroxyl radicals (OH.). These free radicals are highly reactive, with half-lives in the order of milliseconds and are toxic in high concentrations. A potential for free radical generation in Dupuytren's contracture was elicited by finding a sixfold increase in hypoxanthine concentrations in Dupuytren's contracture compared with control palmar fascia. In vitro studies affirmed the toxic effects of oxygen free radicals to Dupuytren's contracture fibroblasts, but also showed that, at lower concentrations (concentrations similar to those likely to occur in Dupuytren's contracture), free radicals had a stimulatory effect on fibroblast proliferation. Cultured fibroblasts were found to release their own O2-. These endogenously released free radicals were also found to be important in fibroblast proliferation. The collagen changes of Dupuytren's contracture were examined. The results established that fibroblast origin was unimportant, but that inhibition of type I collagen production at high fibroblast density accounted for the increase in type III/I collagen ratios observed by previous investigators. These biochemical and morphological observations throw new light on Dupuytren's contracture. They suggest that age, genetic and environmental factors may contribute to micro vessel narrowing with consequent localised ischaemia and free radical generation. Endothelial xanthine oxidase derived free radicals may both damage the surrounding stroma and stimulate fibroblasts to proliferate. Proliferating fibroblasts lay down and contract collagen in lines of stress.Progressive fibroblast proliferation and deposition of collagen is likely to encourage further microvessel narrowing with a positive feedback effect consistent with the progressive nature of the condition.
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PMID:An insight into Dupuytren's contracture. 161 55

A free radical is any species capable of independent existence that contains one or more unpaired electrons. Free radical reactions have been implicated in the pathology of more than 50 human diseases. Radicals and other reactive oxygen species are formed constantly in the human body, both by deliberate synthesis (e.g. by activated phagocytes) and by chemical side-reactions. They are removed by enzymic and nonenzymic antioxidant defence systems. Oxidative stress, occurring when antioxidant defences are inadequate, can damage lipids, proteins, carbohydrates and DNA. A few clinical conditions are caused by oxidative stress, but more often the stress results from the disease. Sometimes it then makes a significant contribution to the disease pathology, and sometimes it does not. Several antioxidants are available for therapeutic use. They include molecules naturally present in the body [superoxide dismutase (SOD), alpha-tocopherol, glutathione and its precursors, ascorbic acid, adenosine, lactoferrin and carotenoids] as well as synthetic antioxidants [such as thiols, ebselen (PZ51), xanthine oxidase inhibitors, inhibitors of phagocyte function, iron ion chelators and probucol]. The therapeutic efficacy of SOD, alpha-tocopherol and ascorbic acid in the treatment of human disease is generally unimpressive to date although dietary deficiencies of the last two molecules should certainly be avoided. Xanthine oxidase inhibitors may be of limited relevance as antioxidants for human use. Exciting preliminary results with probucol (antiatherosclerosis), ebselen (anti-inflammatory), and iron ion chelators (in thalassaemia, leukaemia, malaria, stroke, traumatic brain injury and haemorrhagic shock) need to be confirmed by controlled clinical trials. Clinical testing of N-acetylcysteine in HIV-1-positive subjects may also be merited. A few drugs already in clinical use may have some antioxidant properties, but this ability is not widespread and drug-derived radicals may occasionally cause significant damage.
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PMID:Drug antioxidant effects. A basis for drug selection? 172 62

Various non-invasive investigations were carried out in patients infected with HIV who had respiratory symptoms with and without pneumocystis pneumonia (with pneumonia, n = 13 (five smokers); without pneumonia, n = 22 (13 smokers]. These included chest radiography; lung function tests (forced expiratory volume in one second, forced vital capacity; transfer factor and coefficient for carbon monoxide); arterial blood gas tensions; arterial oxygen saturation at rest and on exercise; and lung clearance of diethylenetriaminepenta-acetic acid labelled with technetium-99m (99mTc DTPA). The effect of scan time (seven v 45 minutes from peak counts) and subtraction of background counts were examined. There were no significant differences between the two groups in lung function tests or arterial blood gas tensions at rest. The median clearance half time of inhaled 99mTc DTPA for the first seven minutes from peak counts was 7.2 minutes for patients with pneumocystis pneumonia and 22 minutes for those without. The median arterial oxygen desaturation on exercise was 5% in patients with pneumocystis pneumonia and 2% in those without. 99mTc DTPA lung clearance was better than the other non-invasive tests in discriminating pneumocystis pneumonia from other pulmonary disorders in patients positive for HIV. A short scan time of seven minutes was as sensitive and specific as the longer scan time of 45 minutes, and this allows the clearance of 99mTc DTPA to become a rapid screening test.
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PMID:Diagnostic value of lung clearance of 99mTc DTPA compared with other non-invasive investigations in Pneumocystis carinii pneumonia in AIDS. 154 24

Human Immunodeficiency Virus (HIV) related Pneumocystis carinii pneumonia (PCP) associated with severe respiratory failure is an increasingly common problem in major centres and is associated with a high mortality in previous and recent studies. Early in the epidemic, alternatives to invasive intensive care treatment were utilized in our institution and found to be successful. When respiratory failure developed, mask CPAP was used instead of intubation and ventilation. A retrospective review of 175 cases of HIV infected patients with confirmed first presentation PCP was undertaken. Treatment with our protocol resulted in an overall hospital mortality of 9%. Those patients who did not require supplemental oxygen or respiratory support had no in-hospital mortality. The group who required supplemental oxygen had a mortality of 10%. If respiratory failure supervened (severe respiratory distress, PaO2 less than 50 mmHg, SaO2 less than 90% on mask oxygen), CPAP was introduced. The mortality in this group was 22%. Only two patients were admitted to the intensive care unit for respiratory support after failure of CPAP. Both patients were intubated and received intermittent positive pressure ventilation (IPPV). Both patients died.
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PMID:CPAP, effective respiratory support in patients with AIDS-related Pneumocystis carinii pneumonia. 175 Jun 39

Ultrastructural, immunohistochemical, and biochemical studies to date show that the fibroblast in Dupuytren's contracture is identical to palmar fascia fibroblasts in patients unaffected by Dupuytren's contracture, and to all other fibroblasts. The major difference relating to fibroblasts is that in Dupuytren's contracture there are more of them, and they are clustered around narrowed microvessels. It is probable that these two phenomena are linked because recent studies indicate a greater potential for ischemia-induced oxygen free radical generation in Dupuytren's contracture, and because oxygen free radicals in these concentrations can stimulate fibroblast proliferation. The major source of oxygen free radicals is likely to be from microvascular endothelial xanthine oxidase-catalyzed reactions. These observations also account for many of the epidemiologic associations of Dupuytren's contracture, because (1) age, race, and diabetes are associated with microvessel narrowing and (2) age, diabetes, alcohol consumption, HIV infection, cigarette smoking, and trauma are associated with increased free radical generation. Nonsteroidal anti-inflammatory drugs and allopurinol are two agents that decrease oxygen free radical release and may inhibit or prevent Dupuytren's contracture.
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PMID:The role of the fibroblast in Dupuytren's contracture. 176 89


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