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)

Ventilatory responses to hypoxia (HVR) were investigated using poikilocapnic conditions (i.e. end-tidal CO2's allowed to seek it's own level) in 15 cardio-pulmonary healthy patients who were first studied awake and then at 0.85 MAC isoflurane. The influence of hypercapnia (HyperCapnic Ventilatory Response, HCVR) was also elucidated. Pneumotachography, capnography and airway occlusion pressures at 0.1 s (P degree 0.1) were used before and during both mild hypoxia (end-tidal O2 tension 8.7 kPa) and hypercapnia achieved by an inspired CO2 concentration of 5%. HCVR was attenuated by 60% during anesthesia (P < 0.01). In the awake state, five of the 15 patients decreased HVR during hypoxia as compared with during normoxia. This resulted in a VE that on average increased by 0.6 l.min-1 (P < 0.05) whereas P degree 0.1 was unchanged. In the anesthetized state, no case of decreased HVR was seen and hypoxia induced a mean VE increase (+/- s.d.) by 1.0 +/- 0.2 l.min-1 (P < 0.001) and a P degree 0.1 that on average was improved by 0.63 +/- 0.27 cm H2O (P < 0.01). It is suggested that when the aim is to evaluate the influence of volatile anesthetic agents on HVR and to quantitate its clinical relevance during and immediately after anesthesia, a poikilocapnic technique should be used. It is concluded that the poikilocapnic HVR to PEO2's of 8.7 kPa was maintained during 0.85 MAC isoflurane.
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PMID:Poikilocapnic hypoxic ventilatory response in humans during 0.85 MAC isoflurane anesthesia. 817 50

Intracranial pressure (ICP) has been shown to increase dramatically during desflurane anesthesia, possibly as a result in part of an increase in the rate of cerebrospinal fluid (CSF) formation (Vf) or a decrease in the rate of CSF reabsorption. To examine this phenomenon, I designed a study to measure Vf, resistance to reabsorption of CSF (Ra), brain tissue water content, and the electroencephalographic activity (EEG) during desflurane anesthesia in dogs. Vf and Ra were determined using ventriculocisternal perfusion of mock CSF labeled with blue dextran. EEG activity was determined using aperiodic analysis. At the end of the study, brain tissue water contents of gray and white matter were determined by dry/wet weight ratios. Eighteen dogs were allocated into three groups. Group 1 (n = 6) was examined at five experimental conditions during normocapnia; group 2 (n = 6) was examined at five experimental conditions during hypocapnia. The experimental conditions for groups 1 and 2 were (a) baseline (halothane 0.5-1.0% inspired plus thiopental 12 mg.kg-1 i.v. given over 15 min followed by i.v. infusion at 12 mg.kg-1 x h-1), (b) 0.5 MAC (3.5 +/- 0.1% expired) and (c) 1.0 MAC (7.0 +/- 0.1% expired) desflurane at normal CSF pressure, and (d) and (e) 0.5 and 1.0 MAC desflurane at increased CSF pressure (> 30 cm H2O). Group 3 (n = 6), the control group, was examined over the same time period as groups 1 and 2. In the control group, desflurane was not administered; instead, the baseline condition (i.e., halothane plus thiopental) was maintained throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Rate of cerebrospinal fluid formation, resistance to reabsorption of cerebrospinal fluid, brain tissue water content, and electroencephalogram during desflurane anesthesia in dogs. 840 Jul 57

Infections caused by mycobacteria other than tuberculosis (MOTT), especially Mycobacterium avium complex (MAC), are common in AIDS patients, but rare in immunocompetent persons. The route of transmission is unknown, but tap water could provide a possible source of infection: MAC was isolated from tap water in the U.S.A. but this has not been reported in Germany. We therefore investigated tap water in Berlin for the presence of mycobacteria and compared radiometric (Bactec) and standard plate culture methods processing large volumes of water samples. The Bactec method yielded equal results compared to standard methods but had the advantage of easy handling. Mycobacteria were isolated from 50/118 (42.4%) samples and from 21/30 (70%) sites. The most frequently isolated species was Mycobacterium gordonae (from 28% samples and from 53.3% sites); MAC was isolated from two samples only (1.7%).
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PMID:Isolation of atypical mycobacteria from tap water in hospitals and homes: is this a possible source of disseminated MAC infection in AIDS patients? 852 30

During the terminal stages of AIDS, Mycobacterium avium complex (MAC) infection is the most common disseminated bacterial infection in rhesus macaques (Macaca mulatta) experimentally inoculated with the simian immunodeficiency virus (SIV). The source of mycobacterial infection in 15 SIV-inoculated rhesus macaques housed in a biolevel 3 containment facility was investigated using a sensitive polymerase chain reaction typing technique. Six animal isolates had banding profiles identical to that of 1 environmental isolate obtained from the facility's water distribution system. An additional 6 isolates had banding profiles differing by the addition or loss of one or two bands from this and 1 other water isolate. These findings indicate that potable water may serve as a significant source of mycobacterial infection in SIV-inoculated macaques and suggest that strategies to prevent exposure to mycobacteria within potable water should be investigated as a method to prevent mycobacteriosis in human immunodeficiency virus-infected persons.
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PMID:Simian immunodeficiency virus-inoculated macaques acquire Mycobacterium avium from potable water during AIDS. 898 17

Repeated outbreaks of a suspected viral fever in Chirimiri colliery area, Madhya Pradesh were reported since 1990. The area consists of an agglomeration of sprawling settlements at varying altitudes of 816 to 890 m and it has partial sylvan cover. During a 1992 outbreak 25 patients' sera were tested, of which 13 showed seropositivity to dengue (DEN) by MAC-ELISA test; DEN-2 was isolated from Aedes aegypti collected from two of the eight settlements of the area. The principal vector, Ae. aegypti, was prevalent in all the settlements studied; Breteau indices (BI) varied between 2.5 and 125.0; adult house indices (AHI) between 0 and 60.0%; Ae. albopictus and Ae. vittatus occurred in considerable numbers; Ae. aegypti bred in more containers with nonpotable water than those with potable water; the breeding of this species was noted in a maximum number of cement tanks while mud pots were predominant among the available containers. Paired comparisons between relative prevalence indices showed significant correlation and regression coefficients. Significant association of Ae. aegypti breeding with the households having tap water supply was noted, the relative risk declining with the people's use of well water either exclusively or in combination with other sources of water supply. It was also collected in the nonresidential areas. The role of ecological factors in the maintenance and spread of Ae. aegypti and dengue in these settlements is discussed.
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PMID:Activity of dengue-2 virus and prevalence of Aedes aegypti in the Chirimiri colliery area, Madhya Pradesh, India. 932 95

An antigen of apparent molecular weight of 24,000, reactive with a murine monoclonal antibody, has been isolated from a cachexia-inducing tumour (MAC 16) and has been shown to initiate muscle protein degradation in vitro using isolated soleus muscle. Administration of this material to female NMRI mice (20 g) produced a pronounced depression in body weight (2.72 +/- 0.14 g; P<0.005 from control) over a 24 h period. This weight loss was attenuated in mice pretreated with the monoclonal antibody (0.06 +/- 0.26 g over 24 h) and occurred without a reduction in food and water intake. There was no change in body water composition, and the major contribution to the decrease in body weight was a decrease in the non-fat carcass dry weight (mainly lean body mass). The plasma levels of glucose and most amino acids were also significantly depressed. The decrease in lean body mass was accounted for by an increase (by 50%) in protein degradation and a decrease (by 50%) in protein synthesis in gastrocnemius muscle. Protein degradation was significantly decreased and protein synthesis increased to control values in mice pretreated with the monoclonal antibody. Protein degradation initiated in vitro with the proteolysis-inducing factor was abolished in mice pretreated with eicosapentaenoic acid (EPA), which had been shown to prevent muscle wastage in mice bearing the MAC16 tumour. Protein degradation was associated with a significant elevation of prostaglandin E2 production by isolated soleus muscle, which was inhibited by both the monoclonal antibody and EPA. These results suggest that this material may be the humoral factor mediating changes in skeletal muscle protein homeostasis during the process of cancer cachexia in animals bearing the MAC16 tumour, and could potentially be involved in other cases of cachexia.
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PMID:Induction of muscle protein degradation by a tumour factor. 937 63

The investigations have indicated that in the flood period when the water-purifying means of a water pipe bears the maximum load, the existing water-preparing system cannot fully purify and disinfect drinking water from some opportunistic microbes (Klebsiella, Acinetobacter). The latter were recorded in the pipe water having the MAC of coliform organisms established by the GOST.
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PMID:[Barrier role of water-purifying construction of water pipe in relation to opportunistic microorganisms]. 937 12

The main stages of and principles of methodology of assessment of a carcinogenic risk from exposure to environmental factors are considered. The carcinogenic risks of exposure to MAC of in the ambient air of the populated areas, in the reservoir water, and in the air of a working zone were calculated by using the carcinogenic potential. Analyzing the data obtained has indicated that a great variety of potential carcinogens presents a high risk even if the hygienic standards approved now are followed. The methodological and organization aspects of the use of the procedure for assessing carcinogenic risks in Russia are discussed.
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PMID:[Problems in assessing carcinogenic risk of exposure to chemical pollution of the environment]. 956 Sep 35

Mycobacterium avium complex (MAC) organisms have been isolated from water and soil. It is now generally accepted that environmental sources, especially natural waters, are the reservoirs for most human infections caused by MAC. Previously, we reported that M. avium and M. intracellular were distributed predominantly in the eastern and western part of Japan, respectively. To clarify the factor(s) of the difference, the following experiment was undertaken. MAC was isolated from soil samples collected in Tokai, Kinki and Chugoku districts, by the method of Ichiyama et al. MAC isolates were identified by AccuProbe Confirmation and Identification tests, together with some conventional tests. Seven (11.7%) of 60 isolates were identified as M. avium, twenty (33%) as M. intracellulaer and 33 (55%) as MAC-like organisms. Therefore, it was not found that the difference in the geographical distribution between soil MAC and disease-associated MAC. MAC-like strains possess MAC-specific alpha antigen, and biological and biochemical features of MAC. They reacted with the AccuProbe MAC but not with the AccuProbe M. avium and M. intracellulare. Sequencing analysis of 16s RNA gene implies that MAC-like strains show an intermediate sequence pattern of M. avium and M. intracellulare. HPLC patterns of these strains were compatible with those of MAC. It is known that the major serovars of MAC isolates from patients with or without AIDS are different. Serological aspects in this respect are not yet elucidated well in Japan. The major serovars of MAC from patients with AIDS are 4 and 8 in the USA and Australia, 6 and 4 in Sweden, and 8/21 and 8 in Germany. On the other hand, the major serovars of MAC from patients without AIDS are 8 and 16 (15) in the USA and 6 and 1 in Sweden. According to out recent study the major serovars of MAC from non-AIDS patients are 1 and 8 in the eastern part and 16 and 14 in the western part of Japan. In the present study, 38 MAC isolates from sputum, stool and blood and AIDS patients were identified. All of the isolates were identified as M. avium. Serovars of 15 strains were 4 (4 strains), 8 (3 strains), 9 (3 strains), 3 (2 strains), Darkin (2 strains) and 1 (1 strain). Therefore, it seems that the major serovars of the Japanese MAC strains from AIDS patients are similar to those of the American MAC strains from such patients.
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PMID:[Geographical distribution of Mycobacterium avium complex in environment and serovars of Mycobacterium avium complex isolates from patients with and without AIDS]. 963 23

Volatile anesthetic concentrations have been difficult to measure, but are an important experimental parameter for in vitro studies of anesthetic actions. Calcium sensitive electrodes were investigated as a means of continuously monitoring anesthetic concentrations in artificial cerebrospinal fluids (ACSF). Anesthetic-induced Ca2+ electrode signals were compared at room (22 degrees C) and physiological (35 degrees C) temperatures. Electrophysiological measures of anesthetic effects on synaptic potentials provided a bioassay. Halothane and isoflurane produced negative changes in calcium electrode potentials which were linearly related to concentrations over a clinically useful range (0.5-1.5 MAC). Anesthetic-induced voltages persisted in nominally zero Ca2+ ACSF and even in deionized water. A good correlation (r>0.9) was found for calcium electrode measures of anesthetic concentration and synaptic response depression produced by halothane, at both 22 and 35 degrees C. These results support three conclusions: (1) calcium sensitive electrodes provide a useful measure of volatile anesthetic concentrations in aqueous solution. (2) Care must be taken when using these electrodes for Ca2+ concentration measurements, if a volatile anesthetic is also to be used, since the anesthetic could introduce an appreciable error (>50%). (3) A temperature change of 13 degrees C had surprisingly little effect on Ca2+ electrode responses or on synaptic depression produced by anesthetics.
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PMID:Concentration measures of volatile anesthetics in the aqueous phase using calcium sensitive electrodes. 969 23


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