The effect of long-distance running on some biochemical variables.

Biochemical variables have been measured in a group of volunteers during and after a long-distance run. Plasma glucose levels remained relatively constant and a significant decrease in plasma bicarbonate was noted. Plasma sodium, chloride, total protein, albumin and calcium showed significant increased of an order compatible with water losses occurring during the run. Plasma potassium, urea, creatinine, uric acid, phosphate and bilirubin all show much more marked and variable increases. The plasma enzymes alkaline phosphatase, lactate dehydrogenase, aspartate aminotransferase and creatine kinase likewise increased significantly throughout the run. Whilst most constituents showed a tendency to return to normal at 20-30 hours after the run, gross increases were observed for aspartate aminotransferase and creatine kinase.     

Activities of mitochondrial aspartate aminotransferase and creatine kinase isoenzyme MB in serum following coronary bypass surgery

The mitochondrial isoenzyme of aspartate aminotransferase showed only slight increases in serum of twenty-seven patients after uncomplicated coronary bypass surgery, which contrasted the rapid and substantial increases in creatine kinase MB. In seven patients suffering perioperative infarction or serious complications, substantial increases in mitochondrial aspartate aminotransferase were detected and the elevations in creatine kinase MB were prolonged. Mitochondrial aspartate aminotransferase may appear as a specific marker of myocardial necrosis following coronary bypass surgery. The elevations of creatine kinase and creatine kinase MB were detected as early as 5 minutes after onset of coronary reperfusion and slightly higher activities were measured in coronary sinus blood than in systemic blood sampled simultaneously. Increases in mitochondrial aspartate aminotransferase, however, could first be measured 8 hours after reperfusion.     

The effect of a short burst of exercise on activity values of enzymes in sera of healthy young men

We report the effect of exercise on the activity values of five enzymes in sera as studied in four healthy male volunteers. The underlying purpose of this present study was to produce an increase in the activity values in the sera of selected enzymes found in muscle. Then by observing the decay rate of these enzymes, we computed the inter-individual differences in clearance rates (serum half-life) of these enzymes.Blood specimens were collected just prior to exercise, 1 h after exercise, and on eight additional times up to 93 h after exercise. All specimens were assayed on one occasion for activity values of creatine kinase, asparate aminotransferase, alanine aminotransferase, alkaline phosphatase, and lactate dehydrogenase. We found increases in the three muscle enzymes with average increases being: creatine kinase, +116%; aspartate aminotransferase, +41%; and lactate dehydrogenase, +32%; all of which remained above baseline values for 53 h or longer. In the case of creatine kinase, a monoexponential decay curve depicted the data (from the 19-h specimen to the 67-h specimen). The calculated “apparent serum half-life” for creatine kinase varied from 38 h to 118 h in the subjects tested.     

Enzyme activities of NADPH-forming metabolic pathways in normal and leukemic leukocytes.

With respect to the enzymes of NADPH-forming metabolic pathways in human leukocytes: (a) Glucose-6-phosphate dehydrogenase and phosphogluconate dehydrogenase (decarboxylating) were less active in leukocytes (mostly myeloblasts) from eight patients with acute myeloblastic leukemia (I) than in leukocytes (mostly granulocytes) from 16 normal subjects (II). (b) Of the enzymes of the citrate cleavage pathway, ATP citrate lyase and malate dehydrogenase (decarboxylating) (NADP+) were virtually absent in the cells studied. (c) Isocitrate dehydrogenase (NADP+), aspartate aminotransferase, and alanine aminotransferase, which, together with the much more active malate dehydrogenase, constitute a newly proposed NADPH-forming metabolic cycle, showed a higher activity in I than in II or III, and therefore could compensate, as concerns NADPH-generation, for the low activity of pentose cycle dehydrogenases. We are not sure whether the enzymatic characteristic of I cells is attributable to their immaturity or to their leukemic nature.     

The estimation of ammonia in kidney slices in the presence of added glutamine and other amino acids.

This paper reports a study of changes in red blood cell enzymes and some serum parameters during and after treatment of protein-calorie malnutrition. The red cell GSH levels were low during the crisis, together with the levels of GSSG:NADPH reductase, GSH:H₂O₂ peroxidase, aspartate aminotransferase and alanine aminotransferase. After treatment the levels of all these enzymes increased significantly to normal values.Of the serum parameters investigated, significant reduction in the activity of the enzymes cholinesterase, catecholamine oxidase, total proteins, albumin, urea and electrolytes were obvious, and returned to normal values after treatment. Ceruloplasmin activity remained low even after three weeks' treatment and could not be related to copper levels.The results are discussed in relation to anemia and liver damage that may accompany the syndrome.     

Ceforanide: In Vitro and Clinical Evaluation

Ceforanide, a new cephalosporin antibiotic with a long half-life (3 h), can be administered twice daily. We evaluated its antimicrobial activity, pharmacology, and clinical efficacy. Twenty-seven patients with infections due to susceptible organisms received ceforanide, 0.5, 1, or 2 g, intramuscularly or intravenously every 12 h for 6 to 28 days. In vitro studies with the clinical isolates from 27 patients treated plus 263 additional isolates showed that ceforanide was active against cephalothin-susceptible gram-positive and gram-negative microorganisms. In addition, ceforanide inhibited 65% of cephalothin-resistant Escherichia coli and 65% of Enterobacter spp. at 相似文献   

长期服用阿立哌唑与氯氮平对精神分裂症患者血清心肌酶的影响

目的：探讨长期服用阿立哌唑与氯氮平对精神分裂症患者血清心肌酶水平的影响。方法对84例服用阿立哌唑及85例服用氯氮平治疗时间＞3 a的精神分裂症患者进行血清心肌酶水平检测分析,指标包括肌酸激酶、肌酸激酶同工酶MB亚型、乳酸脱氢酶和天门冬氨酸氨基转移酶。结果两组肌酸激酶、肌酸激酶同工酶MB亚型、乳酸脱氢酶水平均高于正常值,但氯氮平组显著高于阿立哌唑组（ P＜0．05或0．01）;两组天门冬氨酸氨基转移酶水平与正常值比较均无明显变化。结论精神分裂症患者长期服用阿立哌唑与氯氮平治疗均可导致血清心肌酶水平不同程度的升高,氯氮平升高更为显著,应引起临床医师的关注。     

Alteration of serum enzymes in primary hypothyroidism.

In order to study the relationships between serum enzymes and the degree of hypothyroidism, 114 patients with primary hypothyroidism aged from 7 to 65 years were investigated. Forty one percent of patients exhibited normal levels of serum enzymes, while 59% had high levels either alone or in combination. The frequency of enzyme elevation was as follows: creatine kinase: 37%, aspartate aminotransferase: 35%, alanine aminotransferase: 29%, amylase: 15%, alkaline phosphatase: 3%. No significant correlation between thyroid stimulating hormone and serum enzyme levels was observed. This was due to highly variable release of enzymes from cells resulting presumably from individual metabolic set-point. Replacement therapy with thyroxine resulted in remarkable lowering of creatine kinase not only from high level to normal as early as 3 weeks even before normalization of thyroid stimulating hormone, but also from high normal to low normal level. The elevation of amylase and its response to thyroxine is being reported for the first time.     

Value of enzyme determinations in urine for the diagnosis of nephrotoxicity in rats

Excretion of urinary lactate dehydrogenase (LDH, EC 1.1.1.27), gamma-glutamyltransferase (gamma-GT, EC 2.3.2.2), alkaline phosphatase (ALP, EC 3.1.3.1), alanine aminopeptidase (AAP, EC 3.4.11.-), alanine aminotransferase (GPT, EC 2.6.1.2) and N-acetyl-beta-D-glucosaminidase (NAG, EC 3.2.1.30) was studied following a single i.v. application of 1 mg mercuric chloride/kg body weight or a radio contrast medium (SH H 340 AB) at a dose of 7.5 g iodine/kg body weight in rats. Measurements of urinary enzymes and serum urea nitrogen and creatinine were carried out on the second, third, fourth and ninth days after treatment. Histological examinations of kidneys were performed on day 9. A drastic increase in urinary LDH and moderate increase in gamma-GT, ALP and AAP and a very slight increase in GPT was observed in the first 18-h urine samples after mercuric chloride. This increase in enzymuria was associated with a drastic increase in serum urea nitrogen and creatinine, with a maximum on day 4. The radio contrast medium-treated animals showed a similar but less pronounced pattern of urinary enzymes excretion and only a slight increase of serum urea nitrogen on day 2. A good correlation was found between histological findings and enzymuria as well as serum urea nitrogen and creatinine. Thus, determination of only some urinary enzymes (LDH and gamma-GT) is valuable in predicting early nephrotoxicity and sufficient for the diagnosis of proximal tubule damage in rats.     

Proteinase K inactivation of cytosolic aspartate aminotransferase isoenzyme for measurement of human serum mitochondrial aspartate aminotransferase

We studied a new proteinase K assay method for human serum mitochondrial aspartate aminotransferase. We found that proteinase K showed no inactivation of human mitochondrial aspartate aminotransferase isoenzyme and complete inactivation of cytosolic aspartate aminotransferase. Previous studies have shown that selective proteolytic measurement for mitochondrial aspartate aminotransferase in serum using the protease 401 cleaved peptide bond at Leu 20 from the amino-terminal bond shows complete inactivation of cytosolic aspartate aminotransferase and slight inactivation of mitochondrial aspartate aminotransferase isoenzyme, depending on protease concentration. In this investigation, we found that the proteinase K method does not depend on protease concentration. The proteinase K enzyme inactivation of cytosolic aspartate aminotransferase is caused by the cleavage of the peptide bond at lieu 21 from the aminoterminal bond. In studies with various animal cytosolic aspartate aminotransferase isoenzymes, proteinase K almost completely inactivated cytosolic aspartate aminotransferase. Precision and correlation using proteinase K for measurement of serum mitochondrial aspartate aminotransferase in human showed a good coefficient of variation (within-run <4.45%) and a coefficient of correlation of r = 0.985 (N = 125). © 1993 Wiley-Liss, Inc.     

肝损伤酶活性联合检测在肝胆疾病诊断中的相关分析

目的探讨肝损伤酶活性联合检测在肝胆疾病诊断中的临床意义。方法对健康对照组36例和各类肝胆疾病组204例患者的丙氨酸氨基转移酶、天门冬氨酸氨基转移酶、乳酸脱氢酶、腺苷脱氨酶、线粒体天门冬氨酸转氨酶、碱性磷酸酶、γ-谷氨酰转移酶、5′-核苷酸酶活性进行测定与分析。结果肝胆疾病组丙氨酸氨基转移酶、天门冬氨酸氨基转移酶、乳酸脱氢酶、腺苷脱氨酶、线粒体天门冬氨酸转氨酶、碱性磷酸酶、γ-谷氨酰转移酶、5′-核苷酸酶活性均高于健康对照组（P〈0．01）。结论肝损伤酶活性联合检测有利于肝胆疾病的鉴别诊断及疗效观察。     

Clearance of argininosuccinate synthetase from the circulation in acute liver disease

Argininosuccinate synthetase is an enzyme which has been found to be a specific marker for liver damage. In patients with acute hepatitis, the concentration in serum increases at the onset of the disease, but later decreases more quickly, so that the time required for normalization is shorter than that of alanine aminotransferase. This is probably caused by rapid clearance of argininosuccinate synthetase from the serum. Rapid clearance was demonstrated in experimental animals given purified enzymes intravenously. Argininosuccinate synthetase disappeared from the serum with a half life of about 15 min, while the half lives of alanine aminotransferase and aspartate aminotransferase were 4 and 5 h, respectively, under the same conditions.     

Mitochondrial enzymes in human serum: comparative determinations of glutamate dehydrogenase and mitochondrial aspartate aminotransferase in healthy persons and patients with chronic liver diseases

We measured the activities of two mitochondrial enzymes, the mitochondrial form of aspartate aminotransferase (EC 2.6.1.1) and glutamate dehydrogenase (EC 1.4.1.2), in the serum of apparently healthy persons (n = 84) and patients suffering from chronic liver diseases (n = 43). The distribution of activities for glutamate dehydrogenase, but not mitochondrial aspartate aminotransferase, was sex-dependent. The upper limits of the reference intervals (99th percentile) at 37 degrees C were 3.2 U/L for mitochondrial aspartate aminotransferase, 6.4 U/L for glutamate dehydrogenase (women), and 11.0 U/L for glutamate dehydrogenase (men); there was a weak correlation between the activities of both mitochondrial enzymes (r = 0.439). In patients with chronic liver diseases we found a greater increase in the activity of glutamate dehydrogenase than of mitochondrial aspartate aminotransferase and the correlation between the two mitochondrial enzymes was stronger. The diagnostic sensitivity and specificity of either mitochondrial enzyme was less than that of total aspartate aminotransferase, alanine aminotransferase (EC 2.6.1.2), or gamma-glutamyltransferase (EC 2.3.2.2).     

Biochemical properties of human glomerular basement membrane in normal and diabetic kidneys

To determine the presence of any significant structural abnormalities in the glomerular basement membrane (GBM) of diabetic individuals, GBM from normal and diabetic human kidneys were isolated and analyzed chemically and structurally. The amino acid composition of the normal GBM revealed the presence of significant amounts of hydroxyproline, hydroxylysine, glycine, and carbohydrate suggesting the presence of a collagen-like protein. There was no significant increase in the amount of hydroxylysine, hydroxyproline, or in the hydroxylysine-linked glycoside glucosyl-galactose in the diabetic kidneys. There was, however, a significant decrease in the cystine and sialic acid content of GBM from diabetic kidneys. It was further shown that the alpha-chains isolated from the collagens of normal and diabetic basement membranes had similar amino acid and carbohydrate compositions. The hydroxylysine, hydroxyproline, glycine, and hexose contents were higher by 82, 56, 74, and 94%, respectively in the alpha-chains compared with the intact basement membranes from both the normal and diabetic kidneys. The results indicate that the slight increases in hydroxylysine and hexose content observed occasionally in diabetic GBM preparations are of no statistical significance and cannot be attributed to increases in the activities of enzymes which hydroxylate lysine or glycosylate hydroxylysine, respectively.     

Intra-individual variation of analytes in serum from patients with chronic liver diseases

The average biological intra-individual CV in 20 patients with chronic liver diseases (CLD), estimated for 14 analytes during a stationary phase, significantly exceeded that for a normal group in the cases of Na+, K+, Cl-, total protein, albumin, cholinesterase, hemoglobin, and alpha-amylase; it did not differ significantly from the normal group for cholesterol, alkaline phosphatase, aspartate aminotransferase, and alanine aminopeptidase; and it was significantly lower than in the normal group for alanine aminotransferase and gamma-glutamyltransferase. There were no significant sex-related differences in mean intra-individual variation in CLD patients. Individual values were gaussian-distributed for all analytes, including enzymes. The estimated biological component of intra-individual variation and the analytical variation as determined for each laboratory can be used to derive decision-making criteria in monitoring CLD.     

Demographic and analytic factors affecting the normal range of serum enzyme activities.

1. The effect of demographic variables such as age, sex, body weight, social class and blood pressure upon the activity of serum enzymes in healthy humans is reviewed. A system developed by the author and his colleagues, which automatically adjusts the results of enzyme activity measurements to allow for demographic influences, is described. This allows derivation of a "demographically corrected" normal range; for most enzymes this range is much narrower than that provided by the conventional mean +/- 2 SD approach. 2. The influence of precision and analytical factors upon the normal range for serum enzymes is discussed. Data from a British national quality-control survey reveal a depressing picture of interlaboratory precision for commonly determined enzyme estimations. Examples are given (serum aspartate aminotransferase and guanase) which illustrate the influence that precision of a method may have on the normal range for that enzyme.     

Comparative analysis of enzyme activity in human colostrum, milk, and serum

Changes of enzyme activity in the colostrum, milk, and serum samples of 14 mothers were followed. For the enzyme assay, the colostrum and the milk samples were diluted, 1:10 and 1:5, respectively. The activity of the following enzymes were measured: lactate dehydrogenase (LDH); gammaglutamyl transpeptidase (GGT); aspartate aminotransferase (ASAT); alanine aminotransferase (ALAT); cholinesterase; alkaline, and acid phosphatase. Milk, LDH, ASAT, and ALAT activities did not change during the first four days of lactation, yet were significantly higher than the corresponding activities of serum. The activity of GGT and alkaline and acid phosphatase in milk showed a marked decrease by day 4 postpartum; however, the GGT stayed much higher than that of serum, while the activity of the other two enzymes decreased to the level of the serum. By contrast, as compared to the colostrum, the cholinesterase activity in the breast milk showed a significant increase.     

Apoenzyme content of serum aminotransferases in patients with a renal allograft treated with cyclosporine A and azathioprine

In 16 patients with a renal allograft the activity concentrations of aspartate aminotransferase and alanine aminotransferase and the percentage stimulation of both enzymes were investigated. After the transplantation the patients received prednisone and cyclosporine A as immunosuppressive therapy, while exactly 3 months after the date of transplantation prednisone and azathioprine were given as immunosuppressives. In the first period, the percentage increase of the activity concentration of aspartate aminotransferase and alanine aminotransferase upon supplementation of pyridoxal-5'-phosphate in vitro were similar to that of healthy individuals. In the second period, however, the percentage increase of the activity concentration of alanine aminotransferase was much higher than that of aspartate aminotransferase. Cyclosporine A given during a period of about 400 days did not influence the percentage increase of both enzymes. It is concluded that the high stimulation of alanine aminotransferase in the second period depends on the presence of azathioprine or its metabolites in serum.     

Mode of action of the biotin antimetabolites actithiazic acid and alpha-methyldethiobiotin.

Actithiazic acid and alpha-methyldethiobiotin inhibited the conversion of dethiobiotin to biotin resting-cell suspensions of Escherichia coli. The concentrations which effected 50% inhibition were 0.45 and 1.1 microM for actithiazic acid and alpha-methyldethiobiotin, respectively. Cells grown in low concentrations of the two biotin antimetabolites showed derepression of the biotin A operon, as evidenced by the enhanced levels of the enzymes 7,8-diaminopelargonic acid aminotransferase and dethiobiotin synthetase. Derepression was not due to any direct regulatory effect of the antibiotics but was the consequence of the inhibition of the biotin synthetase enzyme; this inhibition prevented the intracellular concentration of biotin from reaching the levels required for normal regulation of the biotin A operon.     

ICU危重病患者血清酶活性与病情的关系

目的探讨ICU危重病患者 5种血清酶活性的变化及其与病情及预后的关系。方法检测 1 32例危重病患者血清ALT、AST、LDH、AKP、GGT的酶活性 ,其中合并多功能器官障碍综合征 (MODS)患者 60例 ,死亡 2 0例 ,并以 1 0 0例健康体检者作为正常对照组。结果危重病组ALT、AST、LDH、AKP、GGT明显高于正常对照组 (P <0 .0 1 ) ;MODS组与非MODS组 5种酶相比较 ,有显著性差异 ;死亡组又明显高于存活组 (P <0 .0 1 )。结论血清酶活性既可反映ICU危重病患者的病情及预后 ,又是早期判断MODS的重要指标。