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

Scientists at the Ninth International Symposium on Infections in the Immunocompromised Host offered evidence that the rate of HIV disease progression may be determined by how vigorously host defenses are mobilized in the first weeks of infection. Others report on the use of thalidomide or IL-10 for curtailing or suppressing tumor necrosis factor alpha in coincident HIV and tuberculosis patients. The success of shoring up weakened host defenses against the onslaught of opportunistic pathogens, such as mycobacterium avium complex, is also addressed, as are thoughts on using fluconazole to treat fungal infection in HIV-positive patients and the danger of creating a drug-resistant strain of Candida. Recent trial data are discussed in response to questions about prophylaxis and treatment of opportunistic pathogens such as cytomegalovirus (CMV) and Mycobacterium avium complex (MAC). It is suggested that scientists are close to refining assays for CMV, and perhaps MAC, that will allow clinicians to predict which patients have a substantially increased risk of cytomegalovirus or MAC disease. However, it is warned that prophylaxis of opportunistic infections should only be considered as a stop-gap measure, not a way of preventing AIDS.
 ...
PMID:Or is it the host, sir? 1136 95

The second annual National Conference on Human Retroviruses and Related Infections was held in Washington, D.C., January 29-February 2, 1995. Lectures addressed such topics as viral dynamics, United States AIDS epidemiology, immunopathogenesis, antiretroviral therapy, and HIV vaccines. Symposia were held on the interactivity of sexually transmitted diseases (STDs) and AIDS, the causes leading to long-term nonprogressors, and factors causing individuals to be exposed but uninfected. Oral presentations reviewed the following: 1) a study on the efficacy of oral ganciclovir for prevention of CMV disease in CMV-seropositive, HIV-infected individuals with CD4 counts of 50 or less; 2) data supporting rifabutin prophylaxis against MAC infection once the CD4 count is below 100; 3) the safety of the screened blood supply in the United States; 4) ACTG 063, a study examining the use of AZT with and without acyclovir; 5) perinatal transmission; and 6) four independent studies examining the efficacy of 3TC (lamivudine) as part of a combination of antiretroviral drugs in HIV-infected patients who were both AZT-naive and AZT-experienced.
 ...
PMID:Second National Conference on Human Retroviruses. Good news, bad news, and no news. 1137 Jun 57

We studied the incidence of dengue virus (DEN) infections in a cohort of Dutch short-term travellers to endemic areas in Asia during 1991-92. Sera were collected before and after travel. All post-travel sera were tested for DEN immunoglobulin M (IgM) [IgM capture (MAC)-enzyme-linked immunosorbent assay (ELISA)] and IgG (indirect ELISA). Probable DEN infection was defined as IgM seroconversion or a fourfold rise in IgG ratio in the absence of cross-reaction with antibody to Japanese encephalitis virus (JEV). Infections were considered clinically apparent in case of febrile illness (> 24 H) with headache, myalgia, arthralgia or rash. Probable DEN infection was found in 13 of 447 travellers (incidence rate 30/1000 person-months, 95% CI 17.4-51.6). One infection was considered secondary; no haemorrhagic fever occurred. The clinical-to-subclinical infection rate was 1 : 3.3. The risk of infection showed marked seasonal variation. DEN infections are frequent in travellers to endemic areas in Asia; most remain subclinical.
 ...
PMID:Incidence and risk factors of probable dengue virus infection among Dutch travellers to Asia. 1195 49

To define the virus specificity of the immunoglobulin M (IgM) antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA) among the medically important members of the Japanese encephalitis (JE) virus serocomplex of flaviviruses, 103 IgM-positive human serum samples from patients with confirmed West Nile (WN) virus, St. Louis encephalitis (SLE) virus, or JE virus infections were assembled and simultaneously tested against all three viral antigens in a standardized MAC-ELISA. Of the serum samples tested, 96 (93%) showed higher positive-to-negative absorbance ratios (P/Ns) with the infecting virus antigen compared to those obtained with the other two virus antigens. Of the seven specimens with higher P/Ns with heterologous virus antigens, six were from patients with SLE virus infections (the serum samples had higher levels of reactivity with WN virus antigen) and one was from a patient with a JE virus infection (this serum sample also had a higher level of reactivity with WN virus antigen). Not surprisingly, similar virus specificity was observed with WN virus-elicited IgM in cerebrospinal fluid. As shown in previous studies, a subset of these specimens was even less reactive in the MAC-ELISA with dengue virus, a member of a different flavivirus serocomplex. The degree of virus cross-reactivity did not appear to be related to days postonset, at least during the first 40 days of infection. Infections with WN virus could be correctly distinguished from infections with SLE virus on the basis of the observed anti-viral IgM cross-reactivities alone 92% of the time. Infections with SLE virus resulted in antibody that was more cross-reactive, so identification of SLE virus as the infecting agent by use of MAC-ELISA cross-reactivity alone was more problematic.
 ...
PMID:Use of immunoglobulin m cross-reactions in differential diagnosis of human flaviviral encephalitis infections in the United States. 1198 57

Mycobacterium avium complex (MAC) is commonly associated with fever, fatigue, nausea, diarrhea, and cytopenias related to invasion of the intestine and bone marrow. Infection and clinical disease has been reported in other organs as well. We report the first case of cholecystitis associated with MAC infection of the gallbladder.
 ...
PMID:Mycobacterium avium complex-associated cholecystitis in an HIV-infected woman. 1205 27

Infections caused by multidrug-resistant Mycobacterium tuberculosis (MT) and non-tuberculous mycobacteria are difficult to treat and, indeed, new therapeutic agents are being sought. As a part of an ongoing research in our laboratories, novel N-alkyl-1,2-dihydro-2-thioxo-3-pyridinecarbothioamides have been synthesized and evaluated against several strains of MT and Mycobacterium avium complex (MAC). The pharmacokinetics and relative bioavailability after intravenous administration of three derivatives have been investigated. Introduction of a hydroxyl or a tertiary amino group in the N-alkyl chain resulted in an improved pharmacokinetic profile without affecting sensitively the antituberculous potency.
 ...
PMID:New N-alkyl-1,2-dihydro-2-thioxo-3-pyridinecarbothioamides as antituberculous agents with improved pharmacokinetics. 1218 55

Infections with atypical mycobacteria in Australia during 2000 occurred at a rate of 1.8 cases per 100,000 population. The main sites of disease were the respiratory tract, soft tissue, and the lymphatics. The Mycobacterium avium complex was the most common group of mycobacteria isolated from respiratory, lymphatic sites, and blood. The rapidly growing mycobacteria, predominantly the M. fortuitum-M. abscessus-M. chelonae group were the most common soft tissue infections. Atypical mycobacteria were isolated from significant numbers of sputum 'smear positive' patients, requiring further tests to exclude M. tuberculosis. Geographical differences were observed for some Mycobacterium species, notably the isolation of M. haemophilum from Western Australia, and M. ulcerans from Victoria and Queensland. Newer molecular techniques, while improving precision and accuracy of identification, raise additional questions about the ecology of the atypical mycobacteria and their role in disease.
 ...
PMID:National atypical mycobacteria survey, 2000. 1292 33

Mycobacterium avium complex (MAC) is a significant cause of opportunistic infection in patients with acquired immunodeficiency syndrome. Although the major route of entry of MAC is via the gastrointestinal tract, MAC can infect humans through the respiratory tract and eventually encounter alveolar macrophages within the lung. Once in the lung, MAC can potentially interact with surfactant protein A (SP-A), an important component of the pulmonary innate-immune response. Previous work on other pulmonary pathogens including Mycobacterium bovis Bacillus Calmette-Guerin (BCG) suggests that SP-A participates in promoting efficient clearance of these organisms by alveolar macrophages. In the present study, we investigated the role of SP-A in clearance of MAC by cultured rat macrophages. SP-A bound to MAC organisms and enhanced the ingestion of the mycobacteria by macrophages. Infection of macrophages with SP-A-MAC complexes induced the production of nitric oxide (NO) and tumor necrosis factor-alpha. However, intracellular survival of MAC was not altered by preopsonization with SP-A. In addition, inhibitors of inducible NO synthase did not alter MAC clearance. These results suggest that SP-A can bind to and enhance the uptake of MAC by alveolar macrophages, similar to previous findings with BCG and Mycobacterium tuberculosis.However, unlike BCG and other pulmonary pathogens that are cleared effectively in the presence of SP-A via a NO-dependent pathway, macrophage-mediated clearance of MAC is not enhanced by SP-A.
 ...
PMID:Surfactant protein A enhances Mycobacterium avium ingestion but not killing by rat macrophages. 1296 Feb 70

Cytomegalovirus (CMV) is a significant opportunistic pathogen associated with AIDS and immunosuppressive therapy. Infection of the mature central nervous system (CNS) can cause significant pathology with associated neurological deficits, mental disorders, and cognitive impairment and may have potentially fatal consequences. Using genetically immunocompromised mice, we studied mechanisms of CMV invasion into, and behavior within, the CNS. Adult immunodeficient (nude and SCID) and control mice were peripherally infected with recombinant mouse CMV expressing a green fluorescent protein reporter gene. Control mice actively eliminated acute peripheral infection and were resistant to invasion of CMV into the brain. In contrast, virus infected brains of immunodeficient mice but only after a minimum of 21 days postinoculation. After inoculation, CMV was found in circulating leukocytes (MAC-3/CD45(+)) and in leukocytes within the brain, suggesting these cells as a possible source of CMV entry into the CNS. CNS infection was observed in many different cell types, including neurons, glial cells, meninges, ependymal cells, and cells of cerebral vessels. Infection foci progressively expanded locally to adjacent cells, resulting in meningitis, choroiditis, encephalitis, vasculitis, and necrosis; clear indication of axonal transport of CMV was not found. Regional distribution of CMV was unique in each brain, consisting of randomly distributed, unilateral foci. Testing whether CMV gained access to brain through nonspecific vascular disruption, vascular injections of a tracer molecule revealed no obvious disruption of the blood brain barrier in mice with CMV in the brain. Results indicate the importance of host adaptive immunity (particularly T cells) in controlling entry and dissemination of CMV into the brain and are consistent with the view that virus may be carried into the brain by circulating mononuclear cells that traffic through the blood brain barrier.
 ...
PMID:Systemic immune deficiency necessary for cytomegalovirus invasion of the mature brain. 1472 3

Nontuberculous mycobacteria (NTM) are important environmental pathogens that can cause a broad spectrum of diseases. The last few years brought several changes in this expanding field: The number of infections that can be associated with specific species as well as the number of new species as etiological agents has exploded due to the development of new diagnostic tools. The incidence of disseminated Mycobacterium avium complex (MAC) infections in HIV patients is decreasing with more potent anti-HIV treatments, while the rate of pulmonary NTM infection and disease as well as the prevalence of Buruli ulcer, a chronic, necrotizing, progressive ulcerous disease caused by Mycobacterium ulcerans, is increasing. The disease manifestations depend on the interaction between the specific mycobacterial pathogen and the host's immune system. This article presents an update of the epidemiology, diagnosis, and treatment of NTM-associated pulmonary disease, lymphadenitis, skin and soft tissue disease, skeletal infection and foreign body- and catheter-related NTM infections.
Infection 2004 Oct
PMID:Nontuberculous mycobacterial infections: a clinical review. 1562 89


<< Previous 1 2 3 4 5 6 7 8 Next >>