Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.2.1.1 (ACS)
 78,556 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Methods are described for the direct optical assay of citrate, acetate, and acetoacetate production by isolated, incubated rat liver mitochondria. Each metabolite is converted into acetyl-CoA, using ATP: citrate lyase or acetyl-CoA synthetase or acetoacetyl-CoA synthetase and acetyl-CoA acetyltransferase, respectively. Arylamine acetyltransferase acts as auxiliary enzyme. It was shown that isolated rat liver mitochondria produce citrate, acetate and acetoacetate, and that production rates are stimulated by pyruvate and hexanoate. It was concluded that these three products might contribute to the transport of acetyl units across the mitochondrial membrane and thus serve as precursors in fatty acid synthesis. The rate of acetyl transfer does not seem to be rate-limiting with regard to the overall-process of fatty acid synthesis from carbohydrates.
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PMID:Transfer of C2-units across the mitochondrial membrane. Direct recording of citrate, acetate and acetoacetate production rates. 66 82

Radiation dose from mammographic techniques was determined as a function of surface exposure, beam quality, and depth. Relative exposure vs. depth was measured in tissue-substitute materials by thermoluminescent dosimetry. The f-factors were calculated from elemental compositions of mastectomy specimens. Dose at depth depends on beam quality as well as exposure and tissue composition. Analysis of data from the ACS/NCI Screening Centers shows current average midbreast doses to be 25 times lower (film/screen) and 3 times lower (Xerox) than the 2 rads previously estimated. Quantitative risk indicators other than midbreast dose are also discussed.
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PMID:Absorbed radiation dose in mammography. 76 Jan 67

Experience with 35 second grafts included in a total number of 310 renal transplants was analyzed to identify factors associated with success. The 2 year life-table renal survival rate of sequential cadaveric grafts is 42 percent compared in 54 percent for primary cadaveric grafts. The 2 year life-table patient survival rate for the same group is 68 percent compared to 72 percent for single cadaveric homotransplants. Twenty-one of 30 patients tested in the interval between grafts developed cytotoxic antibodies to greater than 5 percent of a random panel of cells; 43 percent of these kidneys functioned at least one year; 65 percent functioned for one year or more if the cytotoxicity was 5 percent or less. If the first graft functioned greater than 3 months, the second had a 67 percent chance of functioning for one year; if less than 3 months, the second had a 45 percent one year function rate. Removal of the first transplant at time of second transplantation resulted in an 88 percent one year life-table survival rate of the second kidney in nine patients. Removal prior to second transplantation resulted in a 25 percent one year survival rate in 23 patients. To further evaluate this significant finding, data was obtained through the American College of Surgeons/National Institutes of Health (ACS/NIH) Organ Transplant Registry from five major transplant centers. Thirty-two patients had their first graft removed at time of second transplantation with a 52 percent one year life-table kidney survival rate vs. 29 percent if the first were removed more than 90 days prior to second grafting. Statistical analysis shows this to be significant at the 95 percent confidence level.
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PMID:Sequential renal transplants: some surgical and immunological implications on management of the first homograft. 76 12

A rapid sensitive spectrophotometric assay for the measurement of methylmalonic and propionic acids in urine is described. The assay is based upon the quantitation of propionic acid using acetyl coenzyme A synthetase isolated from baker's yeast. This enzyme is highly specific for acetate and propionate, and acetate interference is eliminated by conversion to citrate. Methylmalonic acid was assayed by converting it to propionate by heat decarboxylation and then measuring the propionate increment over the endogenous amount in the noncarboxylated sample. Studies of urine obtained from normal subjects (by isolation, partial purification, and then assay by the isotope dilution technique) demonstrated urinary excretion of less than 1 mg of propionic acid and 1-5 mg of methylmalonic acid per day. In 22 consecutive patients with documented vitamin B12 deficiency, methylmalonic acid excretion in excess of 30 mg/24 hr was found. In four other patients, with only neurologic involvement methylmalonic aciduria aided in identifying B12 deficiency as an etiologic factor. Methylmalonic acid excretion was measured by direct assay of an aliquot of urine, requiring neither a valine load nor special extraction procedures. Propionic aciduria was variably increased in B12 deficiency and did not correlate either with the severity of the deficit or degree of methylmalonic aciduria. The assay was performed on urine, but it is potentially applicable to tissue extracts. In addition, this assay method can be utilized for the quantification of urine acetate levels as well.
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PMID:Applicability of an enzymatic quantitation of methylmalonic, propionic, and acetic acids in normal and megaloblastic states. 83 Mar 70

In the liver of adult diabetics, the activity of two enzymes of the citrate-cleavage pathway was increased, the change being statistically significant for NADP-malate dehydrogenase (+ 46%, p less than 0.05) but not significant for ATP citrate-lyase (+ 55%, p greater than 0.10). The increased activity of NADP-malate dehydrogenase, together with the previously described elevation of pentose cycle dehydrogenases, suggests enhanced NADPH generation. Considering the recently proposed possibility of extramitochondrial acetyl-CoA formation by routes other than the citrate-cleavage (i.e., via cytoplasmic acetyl-CoA synthetase), our data is consistent with the occurrence of increased lipogenetic capacity.
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PMID:Enzymes of citrate-cleavage pathway in liver of subjects with adult-onset diabetes. 83 95

The Honeywell ACS 1000, an automated computerized scanning system, is evaluated against the recommended manual method for WBC differentials. Over 400,000 data points were gathered by both methods during an 11-month study, employing routine peripheral blood smears and critically characterized control preparations. These data were found to exhibit an effective increase in throughput, precision, comparable accuracy, and a reduction in operator fatigue. In addition, the instrument demonstrates application to the improvement of quality control, teaching, and continuing education.
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PMID:Evaluation of the Honeywell ACS 1000. 84 73

In order to assess the extent to which metabolism within the sheep placenta may influence the transfer of metabolites between mother and foetus at different stages of gestation the activities of enzymes concerned with some aspects of carbohydrate, amino acid and keton body metabolism were determined in placental cotyledons resected from ewes during the last three months of pregnancy. The activities of pyruvate kinase (EC 2.7.1.40), lactate dehydrogenase (EC 1.1.1.27), malate dehydrogenase (EC 1.1.1.37), ATP citrate (pro-3S)-lyase (EC 4.1.3.8), citrate (si)-synthase (EC 4.1.3.7), acetyl-CoA synthetase (EC 6.2.1.1), acetyl-CoA acetyltransferase (EC 2.3.1.9) and 3-keto acid CoA-transferase (EC 2.8.3.5) per gram wet weight cotyledon do not change during the period studied. The activities of alanine aminotransferase (EC 2.6.1.2), aspartate aminotransferase (EC 2.6.1.1), isocitrate dehydrogenase (NADP+) (EC 1.1.1.42), ornithine-oxoacid aminotransferase (EC 2.6.1.13) and 3-hydroxybutyrate dehydrogenase (EC 1.1.1.30) show an increase in activity between the third and fourth months of pregnancy whilst the activities of arginase (EC 3.5.3.1) and possibly pyruvate carboxylase (EC 6.4.1.1) show an increase in activity between the fourth and final months of pregnancy. Ornithine decarboxylase (EC 4.1.1.17) activity declines to one tenth of its activity during this later period. The absence of detectable activities of phosphoenolpyruvate carboxykinase (EC 4.1.1.32) and ornithine carbamoyltransferase (EC 2.1.3.3) indicate that gluconeogenesis and urea synthesis from ammonia do not occur in the sheep placenta. It appears that the ability of the placenta to metabolise several substrates is achieved by the time the placenta reaches its maximum size at approximately 90 days.
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PMID:Enzyme activities in the sheep placenta during the last three months of pregnancy. 84 73

Sixty-four consecutive patients with coronary artery disease who had resections of left ventricular scars during 1969 to 1973 were retrospectively identified. Extent of angiographic coronary artery disease was scored by the jeopardy score system. Size of the abnormally contracting segment (akinetic or dyskinetic in all) was measured as a percent of the end-diastolic ventriculographic perimeter (% ACS). Contractility of the non-ACS was expressed as the difference between the actual ejection fraction and that predicted by the spherical model of Feild and Dowling (excess ejection fraction, XEF.) Perioperative survival correlated with jeopardy score (21 of 27, jeopardy score less than or equal to 6; 19 of 37 jeopardy score greater than 6) and with XEF (30 OF 38, XEF greater than +0.10; 10 of 26, XEF less than or equal to "0.10). When XEF and jeopardy score were combined, the patients were separated into four subgroups with perioperative survival ranging from 89% to 33%. Long-term survival (minimum follow-up period 30 months) in the 40 perioperative survivors also correlated with jeopardy score (95% at 54 mo for jeopardy score less than or equal to 6; 49% for jeopardy score greater than 6). Survival was unrelated to whether or not aortocoronary bypass graft procedures had been done. It is concluded that survival following aneurysmectomy is predicted by two preoperative angiographic variables--the extent of coronary artery disease and the contractility of the non-aneurysmal portion of the left ventricle.
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PMID:Angiographic predictors of survival following left ventricular aneurysmectomy. 88 15

Studies of the acetylator polymorphism in Pushtoons, Tajiks, Hazaras and Usbeks living in Afghanistan revealed a lower frequency of the allele ACS in the last two populations. The results were compared with those of other populations. The importance of this polymorphism for therapy and a possible relation to the use of alkaloids in form of spices and drugs is discussed.
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PMID:The acetylator polymorphism in four populations of Afghanistan. 90 67

1. The ATP dependent acetyl-, propionyl- and butyryl-CoA synthetase activities were measured in the soluble fraction of both guinea-pig heart and liver mitochondria. 2. When measured in 300 mM Tris-HC1, the V of propionate activation in heart (equals 892 munits/mg protein) is much higher than the V of acetate (equals 637 munits/mg protein) and butyrate activation (equals 143 munits/mg protein. Fatty acid competition experiments, however, clearly show that most of the propionate activation (Km equals 7.94 mM) is caused by the acetyl-CoA synthetase (EC 6.2.1.1) (Km for acetate equals 0.8 mM), while the remaining activity is probably caused by a butyryl-CoA synthetase (Km for butyrate equals 0.83 mM). This indicates that in guinea-pig heart the presence of a distinct propionyl-CoA synthetase is very unlikely. 3. In liver a completely different pattern of short-chain fatty acid activation is found: low acetate activation and moderate propionate and butyrate activation. Substrate competition experiments and kinetics of fatty acid activation indicate that in this tissue a distinct propionyl-CoA synthetase is present with high affinity for propionate (Km equals 0.6 mM) and some affinity towards acetate and butyrate (Km values respectively 11 mM and 5.4 mM).
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PMID:The activation of short-chain fatty acids by the soluble fraction of guinea-pig heart and liver mitochondria. The search for a distinct propionyl-CoA synthetase. 112 7


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