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)

The livers of 26 adult males with acquired immune deficiency syndrome (AIDS) were reviewed. The occurrence of portal tracts with diminished lymphocytes, probably reflecting generalized exhaustion of the lymphoid system, was a characteristic morphologic change, and was found in all cases. Kupffer cell hyperplasia was also a frequent finding and probably reflected generalized infection(s). Punched-out clusters of foamy histiocytes filled with acid-fast bacilli, typical for infection with Mycobacterium avium intracellulare (MAC), were found in three patients. In addition, MAC was cultured from two livers without the foamy histiocytic changes. Chronic viral hepatitis (three cases) and deposition of polarizable materials (one case) in the liver might be related to unusual habits of patients with AIDS. In conclusion, livers from patients with AIDS disclosed several kinds of lesions reflecting underlying or associated conditions in AIDS, but these did not contribute to the cause of death in our patients.
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PMID:Pathologic features of the liver in acquired immune deficiency syndrome (AIDS). 348 53

The complement system has developed a remarkably simple but elegant manner of regulating itself. It has faced and successfully dealt with how to facilitate activation on a microbe while preventing the same on host tissue. It solved this problem primarily by creating a series of secreted and membrane-regulatory proteins that prevent two highly undesirable events: activation in the fluid phase (no target) and on host tissue (inappropriate target). Also, if not checked, even on an appropriate target, the system would go to exhaustion and have nothing left for the next microbe. Therefore, the complement enzymes have an intrinsic instability and the fluid-phase control proteins play a major role in limiting activation in time. The symmetry of the regulatory process between fluid phase and membrane inhibitors at the C4/C3 step of amplification and convertase formation as well as at the MAC steps are particularly striking features of the self/nonself discrimination system. The use of glycolipid anchored proteins on membranes to decay enzymes and block membrane insertion events is unlikely to be by chance. Finally, it is economical for the cofactor regulatory activity to produce derivatives of C3b that now specifically engage additional receptors. Likewise, C1-Inh leads to C1q remaining on the immune complex to interact with the C1q receptor. Thus the complement system is designed to allow rapid, efficient, unimpeded activation on an appropriate foreign target while regulatory proteins intervene to prevent three undesirable consequences of complement activation: excessive activation on a single target, fluid phase activation, and activation on self.
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PMID:Control of the complement system. 883 97

Ceramic fibres are amorphous or crystalline synthetic mineral fibres which are characterised by refractory properties (i.c. stability in temperature above 1000 degrees C). In general, ceramic fibres are produced from aluminium oxide, silicon oxide and other metal oxides and less frequently from non-oxide materials such as silicon carbide, silicon nitride and boron nitride. In Poland, the production of ceramic fibres was begun in the Refractory Materials Plant, Skawina, during mid-eighties. The production capacity accounts for about 600 tons annually. It is estimated that approximately 3000 persons are exposed to the effect of ceramic fibres in Poland. During the production of ceramic fibres, concentrations of respiral fibres in the air at work places range from 0.07 to 0.27 f/cm3; during the manufacture of ceramic fibre products from 0.23 to 0.71 f/cm3 and during the application of ceramic fibre products from 0.07 to 1.67 f/cm3. As published data depict, fibres longer than 5 microns are most common in the work environment, and the proportion of fibres with diameters below 1 micron accounts for 40-50%. Bearing in mind the present situation in Poland, namely combined exposure to asbestos (during removal of worn out heat-insulating materials) and ceramic fibres (during installation of new insulation), as well as in view of own investigations and literature data which evidence a strong carcinogenic effect of certain fibres, the following MAC values have been adopted: Dusts of refractory ceramic fibres: total dust-2 mg/m3; respirable fibres-1 f/cm3 (L > 5 microns; D < 3 microns; L: D < 3:1) Dusts of reflactory ceramic fibres mixed with asbestos: total dust-1 mg/m3; respirable fibres-1 f/m3. Dusts of refractory ceramic fibres mixed with other man-made mineral fibres (MMMF): total dust-2 mg/m3; respirable fibres-1 f/m3. According to the IARC, ceramic fibres have been included into group 2B-suspected human carcinogen.
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PMID:[Refractory ceramic fibers, kinds, health effects after exposure, TLVs]. 884 86

In the Czech Republic, mycobacteriosis is relatively rare. The low incidence probably reflects high BCG coverage rates in the Czech population. Globally, the importance of BCG vaccine has been increasing, as a result of acquired immunodeficiencies, particularly HIV infection. The presented case report describes the course of disseminated mycobacteriosis in a Vietnamese asylum seeker with newly diagnosed advanced HIV infection. In HIV patients, disseminated mycobacteriosis, most frequently caused by members of Mycobacterium avium complex (MAC), is mostly manifested in the last stage, AIDS, with extremely severe immunodeficiency, or in immune reconstitution inflammatory syndrome (IRIS), shortly after initiation of antiretroviral therapy. From the beginning, the patient's condition was complicated by multiple simultaneous severe opportunistic infections which, together with gradually progressing atypical mycobacteriosis, resulted in overall exhaustion of the organism. The adverse prognosis of these infections is significantly influenced by prolonged diagnosis based on culture detection of slow-growing mycobacteria. In the above patient, the lethal course was contributed to by resistance to commonly used antitubercular drugs which was only detected post mortem due to time-consuming susceptibility tests.
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PMID:[Disseminated infection with Mycobacterium avium in a patient with newly diagnosed HIV infection]. 2178 28

Fatigue, the enduring sensation of weakness, lack of energy, tiredness or exhaustion, is described by 40%-80% of patients with rheumatoid arthritis as their most disabling symptom with wide-ranging consequences for quality of life. Little attention has been paid to its multidimensional nature or to its reliability as a measure to evaluate progression of the disease. Low impact aerobic exercise affects the level of fatigue, and this same level of fatigue influences the exercise itself. We searched Medline, Cochrane Collaboration Register of Controlled Trials (CCRCT), Lilacs, PubMed and Scopus databases for randomized controlled trials (with appropriate description of methods, materials and results) on the assessment of fatigue and exercise. Review articles, case reports, letters to the editor and editorials were excluded. Of 121 references initially identified, 4 randomized controlled trials met the inclusion criteria. Two studies used the MAF scale (Multidimensional Assessment of Fatigue), one used the MAC (Mental Adjustment to Cancer) fatigue scale, and all trials used POMS (Profile of Mood States) to assess fatigue. All four trials conducted a 12 week program of two to three times/ week and different periods of follow-up. Two studies used low impact aerobic exercise, one used dance-based exercise, and another study followed a home cardiopulmonary conditioning program using a stationary bicycle. While fatigue appears to be a reliable outcome measure in the clinical management of RA, especially when related to exercise prescription, further research is needed to evaluate the correlation between exercise, fatigue and quality of life, using fatigue scales validated to explore the different components of fatigue and its wide-ranging consequences.
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PMID:Exercise and fatigue in rheumatoid arthritis. 2457 9