Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026916 (MAC)
 5,226 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 33-yr-old black intravenous drug abuser with the acquired immunodeficiency syndrome (AIDS) had a massive fatal upper gastrointestinal hemorrhage due to profound and diffuse esophageal ulceration from Candida, as demonstrated by postmortem examination. A 2-yr-old white male with congenitally acquired AIDS had a massive fatal esophageal bleed as a result of esophagitis from Candida albicans, as proven by pathologic examination and culture of endoscopic biopsies. A 27-yr-old black human immunodeficiency virus-seropositive female died from massive lower gastrointestinal bleeding due to extensive small and large intestinal ulceration caused by Mycobacterium avium intracellulare, as proven by microscopic examination and mycobacterial culture of intestinal tissue. These reports extend the clinical spectrum of these infections in AIDS patients by demonstrating that these infections can produce gastrointestinal bleeding.
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PMID:Gastrointestinal hemorrhage due to gastrointestinal Mycobacterium avium intracellulare or esophageal candidiasis in patients with the acquired immunodeficiency syndrome. 173 3

Antibodies to Mycobacterium avium complex (MAC) antigens were measured by enzyme-linked immunosorbent assays and immunoblot analyses in sera from 20 patients with AIDS and disseminated MAC disease, 5 human immunodeficiency virus-seronegative patients with pulmonary MAC infections, and 20 healthy controls. Whereas enzyme-linked immunosorbent assay titers for healthy controls and patients with AIDS and MAC disease were comparable, human immunodeficiency virus-seronegative patients with MAC disease had higher anti-MAC antibody titers (P less than 0.01). Immunoblot analysis with the same sonic extracts indicated that each of the three groups had a limited heterogeneous response to M. avium antigens. No significant differences in immunoblot reactivities were detected. However, immunoblot studies with recombinant nontuberculous mycobacterial antigens revealed that sera from over 90% of the patients with MAC disease and only 25% of controls recognized a recombinant protein derived from a 35-kDa mycobacterial antigen. Although sonic extracts did not permit adequate discrimination of antibody reactivity in patients with MAC disease, recombinant antigens may be useful as indicators of disease.
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PMID:Mycobacterium avium complex disease in patients with AIDS: seroreactivity to native and recombinant mycobacterial antigens. 175 38

The reservoir of Mycobacterium avium complex (MAC) during human infection is the mononuclear phagocyte. In these studies, the ability of certain macrophage-active cytokines to affect MAC growth in human alveolar macrophages was evaluated. Neither recombinant interferon-gamma (2 x 10(2) to 10(3) U/well of 5 x 10(5) cells) nor recombinant macrophage colony-stimulating factor (20 to 50 ng/well), when tested alone, exhibited a consistent ability to induce macrophage targets to inhibit the growth of a clinical strain of MAC serovar 4. However, the combination of these cytokines (1 to 50 ng macrophage colony-stimulating factor + 10(3) U interferon per well) was remarkably effective in diminishing replication of MAC in all experiments. These cytokines were also able to induce alveolar macrophages to restrict MAC growth even though cells were obtained from several individuals with acquired immunodeficiency syndrome (AIDS) or from normal donors and infected in vitro with the human immunodeficiency virus type 1. The effect of this cytokine combination was not abrogated by 10(4) neutralizing U/ml of anti-tumor necrosis factor-alpha antibody. Rather, the combination of interferon-gamma and macrophage colony-stimulating factor appeared to activate intrinsic macrophage mechanisms for restricting MAC growth and deserves further study to determine the potential value of this cytokine combination in the treatment of human infection.
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PMID:Growth inhibition of Mycobacterium avium complex in human alveolar macrophages by the combination of recombinant macrophage colony-stimulating factor and interferon-gamma. 190 Apr 25

An increase in tuberculosis cases in the United States has been partially linked to the large number of patients with acquired immunodeficiency syndrome. Symptoms are indistinguishable from those of other opportunistic infections and include cough, low-grade fever, and weight loss. In patients with early human immunodeficiency virus (HIV) infection, radiographic findings resemble those seen in patients with reactivation tuberculosis. In patients with advanced HIV infection, chest radiographs typically reveal bilateral, symmetric, coarse, nodular densities. An upper lobe distribution is not prevalent. Lymphadenopathy is reported in many patients. Antituberculous therapy leads to clinical and radiographic improvement. Radiographic deterioration during therapy should suggest the presence of another opportunistic infection. Mycobacterium avium complex (MAC) infection of the lung cannot be distinguished from tuberculosis clinically or radiographically. Therapy, however, is less likely to be successful in patients with MAC infection.
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PMID:Mycobacterial disease in AIDS. 194 94

The nef gene is conserved among all human and simian lentiviruses. However, the amino acid similarity between simian immunodeficiency virus (SIV) and human immunodeficiency virus type 1 NEF is only 38%. To assess the role of SIV NEF on virus replication and compare its activity with that of its human immunodeficiency virus type 1 counterpart, we examined the activity of an intact nef gene from proviral clone pSIV 102, an isolate from SIV-MAC-251-infected cells. Proviral clone pSIV BA was constructed by introducing a premature termination codon at codon 40 of the nef gene without altering the predicted amino acid sequence of the overlapping env gene. These two clones were transfected into CD4- COS cells, and virus replication was monitored by p27 enzyme-linked immunosorbent assay kits. In seven independent experiments, clone pSIV BA afforded two- to sixfold greater levels of viral antigen compared with those in clone pSIV 102 and two- to sixfold-increased levels of viral mRNAs as indicated with Northern (RNA) blot and S1 nuclease protection analyses. Nuclear run-on assays demonstrated a two- to threefold increased rate of RNA synthesis with nuclei isolated from cells transfected with pSIV BA compared with that from cells transfected with pSIV 102. In contrast, there was no apparent destabilization of SIV mRNAs by NEF, as measured in dactinomycin-treated cells. This study demonstrates that SIV NEF is a negative regulator of virus replication and acts by suppressing the level of mRNA synthesis and accumulation in COS cells.
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PMID:Simian immunodeficiency virus negative factor suppresses the level of viral mRNA in COS cells. 204 Oct 81

The histopathologic changes of bone marrow during infection with the human immunodeficiency virus type 1 (HIV-1) are described. Bone marrow biopsies from 73 patients at different stages of HIV-1 infection were studied. Indications for biopsy included peripheral blood abnormalities, suspicion of lymphoma, or search for specific pathogens. Common histopathological features, suggestive of HIV-1 infection but nonpathognomonic were hypercellularity (67%), myelodysplasia (86.1%), plasmacytosis (98.6%), lymphocytic infiltration (31.1%) and histiocytic infiltration with or without granulomata (13.7%). Increases in reticulin fibers (54.7%), and stainable iron deposits, vascular congestion and serous atrophy of fat were frequent features. Opportunistic infections and neoplastic complications were detected in 7 cases: pathogens were demonstrated in 4 cases (Mycobacterium avium intracellulare (MAI), Cryptococcus neoformans, Toxoplasma gondii and Leishmania) and lymphoma in 3 cases (1 Burkitt lymphoma and 2 Hodgkin's disease). Bone marrow hypoplasia is usually a terminal event in AIDS and may be iatrogenic.
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PMID:Bone marrow findings in HIV infection: a pathological study. 210 65

Atypical mycobacterial infections play an important role in human pathogenicity. Mycobacterium avium complex has been reported to occur in 17% to 50% of individuals infected with human immunodeficiency virus. In the southwestern United States, Mycobacterium kansasii is reported to be a predominate mycobacterial infection in middle-aged men. The epidemiology of the pathological species is discussed along with current recommendations for chemotherapeutic regimens.
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PMID:Atypical mycobacterial infections. 226 42

Cercopithecus aethiops (African Green monkey), a nonhuman primate species distributed throughout subsaharan Africa, has been shown to have high seroprevalence rates of antibodies to simian immunodeficiency virus (SIV), and therefore, has been proposed as a natural reservoir for immunodeficiency viruses. Our laboratories have isolated SIV-like viruses from two East African subspecies of C. aethiops designated grivet and vervet monkeys. Analysis of the structural proteins based on the molecular weights and immunologic cross-reactivity to the prototypic SIV(MAC), HIV-1, and HIV-2 isolates suggests that these viruses are distinctly different. Heterogeneity was observed in the molecular weights of the gag, pol, and env gene products between SIV isolates from vervets [SIV(AGM(VER))] and grivets [SIV(AGM(GRI))]. Phenotypically, SIV(AGM(VER)) isolates were distinguishable from SIV(AGM(GRI)) isolates by the apparent size difference of the major core antigen p24. All SIV(AGM(GRI)) and SIV(AGM(VER)) isolates were found to encode a transmembrane protein of approximately 40 kD (gp40) in contrast to gp32 of SIV(MAC). Furthermore, the transmembrane protein was shown to be encoded by the entire env open reading frame, unlike gp32 of SIC(MAC) or gp36 of SIV(AGM(TYO-1)). These data indicate that viruses from C. aethiops share common features with SIV(MAC) and HIV-1, but represent diverse SIV-like viruses which may vary according to subspecies and geographic location.
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PMID:Isolation and characterization of simian immunodeficiency viruses from two subspecies of African green monkeys. 234 Jan 99

Gastrointestinal disease in AIDS is common and is due to opportunistic infections, aggressive malignancy and possible direct HIV enteropathy. Disabling gastrointestinal symptoms are prominent both in patients with established AIDS and in patients with earlier stages of HIV infection. We report the cases of 160 patients with AIDS who underwent gastroenterological investigations at St Vincent's Hospital, Sydney, between November 1983 to October 1987. Of these, 127 had the diagnosis of AIDS established prior to referral and 33 patients had the diagnosis of AIDS established as a result of gastroenterological investigations. Diarrhoea and weight loss (88%) were the most frequent reasons for undertaking gastroenterological investigations. Swallowing disorders (47%), abdominal pain (20%), oral and perianal disease (74%) and evidence of hepatobiliary disease were the other major indications for investigation. In 90% of cases there was evidence of concurrent and active gastrointestinal disease at two or more sites within the alimentary tract. Results from this series reveal a wide range of infectious pathogens: viral (Cytomegalovirus, Herpes simplex), bacterial (Mycobacterium avium intracellulare) and parasitic (Cryptosporidium, Isospora belli). Kaposi's sarcoma and non-Hodgkin's lymphoma were the only malignancies detected in this series. Gastrointestinal disease associated with HIV infection is common, and contributes significantly to its overall morbidity and mortality. Moreover, chronic diarrhoea, weight loss and malnutrition may also contribute to the overall immunodeficiency.
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PMID:The gastrointestinal manifestations of AIDS. 234 18

Infectious molecular clones of the human immunodeficiency virus type 2 (HIV-2) will be valuable tools for the study of regulatory gene functions and the development of an animal model for the human acquired immunodeficiency syndrome (AIDS). To this end, we have cloned and sequenced a novel HIV-2 isolate, HIV-2BEN. One clone, designated MK6, is infectious for various human T-cell lines and for human and macaque peripheral blood lymphocytes (PBL), allowing molecular studies of HIV-2 infection and replication. Since MK6 is highly cytopathic in MT-2 and Molt-4 clone 8 cells, antiviral agents and neutralizing sera may be tested. Cluster analysis of HIV-1, HIV-2, and simian immunodeficiency virus (SIV) env and gag genes revealed that HIV-2BEN yielded the earliest node of phylogenetic divergence for all reported HIV-2 sequences. Noise analysis showed that, with the current data, no specification of any branching order can be made among the four groups of primate lentiviruses, HIV-1, HIV-2/SIVSMM/MAC, SIVAGM, and SIVMND.
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PMID:A novel proviral clone of HIV-2: biological and phylogenetic relationship to other primate immunodeficiency viruses. 235 57


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