The patient as an adult learner.
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Adult↗
Biomedical subjects
L M Shaw
Publications and source records attributed to L M Shaw.
A teaching plan for coronary artery bypass.
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Coronary Artery Bypass↗
A teaching plan for Nissen fundoplication.
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Hernia, Diaphragmatic↗
Electrocardiographic changes following a cardiac stab wound. Case report and review of the literature.
A patient is described who sustained a cardiac stab wound which was associated with ECG evidence of a full thickness myocardial infarction. Subsequent investigation showed a localized area of dyskinesia on left ventricular angiography, but normal thallium myocardial perfusion and normal anatomy on coronary angiography. The patient was managed conservatively and made a complete and uneventful recovery. It is concluded that extensive ECG changes following a cardiac stab wound need not be associated with major coronary artery damage.
Adolescent↗
Immunochemical evaluation of the organ specificity of prostatic acid phosphatase.
In a survey of normal and cancerous human tissues we determined the distribution of immunoreactive prostatic acid phosphatase, using rabbit antiserum to acid phosphatase purified from prostatic fluid. In all normal tissues and blood cells studied except leukocytes we found less than 0.1% (expressed as micrograms per gram of wet weight of tissue) of the quantity of immunoreactive prostatic acid phosphatase detected in normal prostate tissue by radioimmunoassay. A small quantity of cross-reactive antigen (2.5 microgram/10(8) cells) was found in leukocytes. In all normal and cancerous nonprostate tissues surveyed by an immunohistochemical technique we detected no immunoreactive prostatic acid phosphatase, except in kidney tissue. Faint but reproducible staining was detected in the lumen of distal tubules and collecting ducts and within interstitial capillaries. Immunoreactive prostatic acid phosphatase was detected in the urine of pre- and post-pubertal males and females. We propose that this material is from serum (low concentrations of immunoreactive prostatic acid phosphatase are present in the serum of men and women) and that it is excreted into urine by the kidneys. Full proof of this must await future experimentation. The specificity of our antiserum for prostatic acid phosphatase was demonstrated by the fact that the Mr 100 000 and 20 000 liver acid phosphatase isoenzymes did not cross with our antiserum in either the radioimmunoassay or double-diffusion analysis. Similarly, preparations of isoenzymes 5A and 5B are human serum albumin did not cross react.
Acid Phosphatase↗
Designing an outpatient surgery program.
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Ambulatory Surgical Procedures↗
Electrophoretic, kinetic, and immunoinhibition properties of gamma-glutamyltransferase from various tissues compared.
gamma-Glutamyltransferase (EC 2.3.2.2) from human liver, kidney, pancreas, and duodenum migrated in acrylamide gels (65 g/L) as a single band with the following decreasing order of electrophoretic mobility: liver > pancreas > kidney > duodenum. The initial velocity kinetic constants of pancreatic and duodenal gamma-glutamyltransferase and of the enzyme in human serum were determined and compared with those we previously established for the enzyme from human kidney, liver, and serum. The greatest differences were in the glycylglycine competitive-inhibition constants: kidney gamma-glutamyltransferase was the most strongly inhibited and pancreatic enzyme the second most strongly inhibited by high concentrations of glycylglycine, with the liver and duodenal isoenzymes only slightly inhibited and the enzyme in serum not inhibited over the concentration range (0-150 mmol/L) of glycylglycine used. Differences between the other kinetic constants of these isoenzymes were much smaller. Human liver gamma-glutamyltransferase was obtained in a highly purified form by a six-step procedure that included papain digestion of the original homogenate. Rabbit antisera raised against this preparation inhibited liver, kidney, and pancreatic gamma-glutamyltransferase activity equally well (78, 76, and 78% inhibition, respectively), but inhibited the hog-kidney enzyme only slightly (1%). We conclude that the polypeptide portions of the isoenzyme molecules are structurally similar but that the carbohydrate moieties differ significantly in structure and topography.
Duodenum↗
Interaction of gamma-glutamyltransferase from human tissues with insolubilized lectins.
We have characterized the binding of gamma-glutamyltransferase to three insolubilized lectins. Optimal binding was achieved in 2 hours at 25 degrees C for concanavalin A and at 4 derees C for ricinus communis agglutinin 120 and wheat germ agglutinin,and was also a function of the ratio of lectin protein to gamma-glutamyltransferase protein. The interaction of gamma-glutamyltransferase with these three lectins is specific, and release of bound enzyme by carbohydrates follows the same general order of specificity previously observed for the competition between mono or polysaccharides for the lectin carbohydrate binding sites. The binding of trypsin-solubilized liver gamma-glutamyltransferase to the three insolubilized lectins was virtually identical to that of detergent solubilized enzyme. We propose, therefore, that the release by proteolytic enzymes, of gamma-glutamyltransferase from plasma membrane matrix does not significantly alter its carbohydrate structure. We obtained great differences in binding to the three lectins between the liver, kidney, pancreatic and duodenal isoenzymes of gamma-glutamyltransferase. From this data we conclude that carbohydrate content and topography are important distinguishing features of gamma-glutamyltransferase isoenzymes.
Carbohydrates↗
Hydrolysis of glutathione by human liver gamma-glutamyltransferase.
We studied the catalytic hydrolysis of glutathione by human liver gamma-glutamyltransferase [(gamma-glutamyl)-peptide:amino acid gamma-glutamyltransferase, EC 2.3.2.2]. Glutamate production from glutathione was maximal at pH 7.4 (37 degrees C). Kinetically, the liver enzyme is similar to human kidney gamma-glutamyltransferase: their respective Km values with glutathione as substrate are similar (0.096 x 10(-3) mol/L and 0.097 x 10(-3) mol/L, respectively). S-Methylglutathione was hydrolyzed at a slightly higher rate than glutatione by liver gamma-glutamyltransferase. From these findings and other established properties of liver and kidney gamma-glutamyltransferase we propose that human liver is an important site of glutathione catabolism and that gamma-glutamyltransferase in liver catalyzes the first step of the catabolism of glutathione and glutathione conjugates in this organ.
Glutathione↗
Isolation of gamma-glutamyltransferase from human liver, and comparison with the enzyme from human kidney.
We isolated gamma-glutamyltransferase [(gamma-glutamyl)-peptide:amino acid gamma-glutamyltransferase, EC 2.3.2.2] from human liver and compared some of its properties with the same enzyme prepared from human kidney. The enzymes from these two sources are very similar with respect to initial velocity kinetic constants, pH optima of the transpeptidation and autotransfer reactions, heat stability, competitive inhibition by glutathione of the colorimetric assay in which gamma-glutamyl-4-nitroanilide is substrate, stability of catalytic activity to trypsinization, and relative rates of transfer of the gamma-glutamyl moiety from gamma-glutamyl-4-nitroanilide and L-[glycine-2-3/]glutathione to some amino acids and small peptides. The kidney enzyme is inhibited more by the gamma-glutamyl acceptor substrate, glycylglycine, as reflected in a sevenfold lower value for the inhibition constant KiA. Major differences were observed in the lectin-binding properties of liver gamma-glutamyltransferase compared to the kidney enzyme. Lectin-binding property differences are retained for the trypsinized form of the liver and kidney enzymes, although the degree of precipitation was less for certain lectins as compared to the untreated enzyme. Lectin-binding properties were reversed by carbohydrates specific for each lectin. We adapted the histochemical staining technique of Rutenberg et al. [J. Histochem. Cytochem. 17, 517 (1969)] to the detection of gamma-glutamyltransferase activity in acrylamide gels; diffusion artifacts are minimized and the color produced is stable for several days. Untreated and trypsinized forms of the liver enzyme both migrated faster in acrylamide gels (as single bands) than did the corresponding forms of the kidney enzyme.
Humans↗
Increased creatine kinase isoenzyme MB values in patients without myocardial infarct.
Six of 13 randomly selected patients in a medical intensive-care unit with above-normal creatine kinase MB activities had diagnoses other than myocardial infarction. These data, which indicate the need for further study, were obtained during evaluation of a commercially available column procedure (Biodynamics/bmc).
Chromatography, Ion Exchange↗
Progress curve algorithm for calculating enzyme activities from kinetic assay spectrophotometric measurements.
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Autoanalysis↗
An evaluation of a kinetic acid phosphatase method.
The authors have evaluated a new kinetic acid phosphatase method in which the substrate is alpha-naphthyl phosphate. The original claim that this substrate was highly specific for the prostatic isozyme has been strongly challenged. Therefore, large numbers of patients in the following groupings were included in the evaluation: 52 urology clinic patients, 17 patients with uremia, 11 patients with multiple myeloma and 231 patients who had undergone prostatic biopsies. Two hundred seventy of these patients were found to be free of prostatic cancer. Of these, seven had acid phosphatase values above the upper limit of normal. Five of these seven patients had diagnoses of fibromuscular glandular hyperplasia. One was a woman who had multiple myeloma, and one was a uremic patient. Fifteen of 17 patients who had metastatic cancer of the prostate had elevated acid phosphatase activities, whereas one of 24 patients who had cancer of the prostate but no evidence of metastases had an elevated value.
Acid Phosphatase↗
Gamma-Glutamyltransferase: kinetic properties and assay conditions when gamma-glutamyl-4-nitroanilide and its 3-carboxy derivative are used as donor substrates.
The kinetics of human serum gamma-glutamyltransferase (EC 2.3.2.2) were investigated, with use of glycylglycine as a gamma-glutamyl acceptor substrate and gamma-glutamyl-4-nitroanilide and its carboxy derivative, gamma-glutamyl-3-carboxy-4-nitroanilide, as donor substrates. The simultaneous occurrence of both gamma-glutamyltransfer and autotransfer was established by descending paper chromatography. Constant-ratio double-reciprocal plots confirm that the enzyme mechanism is nonsequential (ping-pong bi-bi). Inhibition by either donor was not found, and inhibition by glycylglycine was only observed at concentrations above those of clinical interest. Kinetic constants obtained by nonlinear regression analysis of initial velocity data were used to determine reagent substrate concentrations for the assay of this enzyme. An assay with use of 4 mmol of gamma-glutamyl-3-carboxy-4-nitroanilide and 100 mmol of glycylglycine per liter yielded equivalent activities to those by assay with use of 4 mmol of gamma-glutamyl-4-nitroanilide and 40 mmol of glycylglycine per liter. These concentrations of the carboxy donor and glycylglycine are also "cost optimal" and present no procedural problems when used.
Anilides↗
Determination of the mechanism and kinetic constants for hog kidney gamma-glutamyltransferase.
The initial-velocity kinetics of hog kidney gamma-glutamyltransferase were studied. Glutamate gamma-(4-nitroanilide) and its 3-carboxy derivative, glutamate gamma-(3-carboxy-4-nitroanilide), served as gamma-glutamyl donors, and glycylglycine as an acceptor. Reaction products were identified by paper chromatography and amino acid analysis. Inhibited Ping Pong mechanisms and a comprehensive initial- velocity expression were developed which account for the observed simultaneous gamma-glutamyl transfer and autotransfer, competitive inhibition by glycylglycine, and non-competitive inhibition by the carboxy donor. The validity of the proposed Ping Pong mechanisms are supported by enzyme-velocity data obtained with constant ratios of acceptor to donor concentrations. Kinetic constants were determined by a non-linear regression analysis. With glutamate gamma-(4-nitroanilide) as the donor, Michaelis constants for the donor, acceptor and donor-acting-as-acceptor are 1.87, 24.9, and 2.08 mM respectively. With glutamate gamma-(3-carboxy-4-nitroanilide) as the donor, these Michaelis constants are 1.63, 16.6, and 12.3 mM. Glyclyglycine competitive inhibition constants with the parent donor and its carboxy derivative are 275 and 205 mM respectively; the non-competitive inhibition constant of the carboxy donor is 34 mM.
Anilides↗
Effect of halothane anesthesia on muscle, liver, thyroid, and adrenal-function tests in man.
Seven healthy men volunteers received 6.6 +/- 1.3 (SD) percent-hours of halothane oxygen anesthesia without surgery. Serum bilirubin, alanine aminotransferase, and aspartate aminotransferase significantly increased after anesthesia, which may indicate subclinical liver-cell damage. Creatine kinase of skeletal muscle origin increased above 90 U/liter in six subjects, indicating subclinical muscle-cell damage. Cortisol, triiodothyronine uptake, thyroxine, and free thyroxine index increased significantly immediately after anesthesia. Serum bromide concentrations had increased by fivefold on the second day after anesthesia, and on the ninth day was still elevated fourfold. Oral temperatures increased 0.7 degrees C 6 h post-anesthesia, possibly because of increased thyroxine activity. Lactate dehydrogenase, hydroxybutyrate dehydrogenase and gamma-glutamyltransferase activities did not change significantly. No drugs administered during the course of this study chemically interfered with any of the test methods used.
Adrenal Glands↗
Increased serum bromide concentration after halothane anesthesia in man.
Seven healthy male volunteers received 6.6 plus or minus 0.5 (SE) per cent-hours of halothane-oxygen anesthesia without surgery. Serum bromide concentrations increased from 0.6 plus or minus 0.1 before anesthesia to 2.9 plus or minus 0.2 mEq/l on the second day after anesthesia. On the ninth day serum bromide was still elevated to 2.5 plus or minus 0.1 mEq/l. These bromide concentrations represent psychoactive levels and may account for previously recognized prolonged changes in mood and intellectual function after halothane. Plasma and urinary fluoride concentrations did not increase significantly.
Adult↗