Gastroscopic and histochemical study of normal, atrophic and hypertrophic mucosa.
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Senile muscles of the rat (28-36 months) show loss of overall activity of glycolytic and aerobic enzymes. However, there is a differential loss and shift of enzyme activity pattern in the three types of muscles. The extensor digitorum longus (EDL) and diaphragm show a decrease of ratios of glycolytic to aerobic-oxidative enzymes. This shift to a more oxidative type of metabolism is not observed in the soleus muscle. Decrease of enzyme activities is least marked in the diaphragm muscle. Biochemical analysis shows a trend to levelling out of metabolic differences between the different muscle types. This trend of 'dedifferentiation' is most marked when comparing EDL and soleus, least marked when comparing EDL and diaphragm muscle. The histochemical analysis shows a shift from the original mixed to a more uniform pattern of muscle fibres in the EDL and soleus muscle; this levelling-out of differences between enzymatic activities of different muscle fibres is not observed in the diaphragm muscle. Preferential atrophy and loss of ATPase activity in II muscle fibres in the soleus muscle and the occurrence of 'type grouping' are further characteristic features of senile muscle change. The findings show general (i.e. loss of enzyme activities) and differential trends of biochemical and histochemical enzyme changes in different types of muscles.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The activities of lactate dehydrogenase (LDH), glucose 6-phosphate dehydrogenase (G6PD) and glyceraldehyde 3-phosphate dehydrogenase (GAPD) in two zones of the epithelium of the lens of 6- and 27-month-old rats were measured using quantitative cytochemical methods. In both age groups, the epithelium in the equatorial zone showed the highest enzymatic activity. LDH activity was similar in young and old rats in both areas. G6PD and GAPD activities in the central area were similar in both age groups, but their activity was markedly lower in the equatorial zone in old rats compared to young ones. This decrease in G6PD and GAPD activities may play a role in cataract formation.
The properties of 12 enzymes related to the glycolytic and oxidative metabolism of glucose were examined in normal and malignant epithelium of human uterine tissues to develop optimised assays suitable for both types of tissue and to delineate important kinetic differences that may exist between them. All assays gave acceptable long-term precision, although instability of phosphofructokinase and 6-phosphogluconate dehydrogenase prevented proper assessment; and all were linear with concentration to an absorbance change of 0.04/min, or more in the case of several enzymes. Notable differences between pyruvate kinase of normal and malignant uterine epithelium were found with D-fructose-1,6-diphosphate (FDP) which caused significantly greater activation of the latter as well as a dramatic reduction in Km for phosphoenol pyruvate; inhibition by DL-alanine was greater for pyruvate kinase of malignant than normal cervix epithelium, whereas endometrium did not show this difference. The ratio of aldolase activity with FDP to that with D-fructose-1-phosphate was greater in malignant than in normal cervix epithelium, no significant difference being apparent in endometrium.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Human platelets were separated by desity-centrifugation into heavy and light populations. Heavy platelets have an average volume approximately twofold greater than light platelets, and have previously been shown to be young platelets. All 11 enzymes of the Embden-Meyerhof pathway plus the five related enzymes: phosphoglucomutase, glucose-6-P dehydrogenase, 6-P-gluconic dehydrogenase, alpha-glycerol-P dehydrogenase, and glutathione reductase (TPNH) were examined in cell lysates from total, heavy, and light platelet populations. Apparent Km for individual enzymes were measured in a total platelet population. Empirical V(max) of the individual enzymes were measured in total, heavy, and light platelet populations. The three apparent rate-limiting enzymes for glycolysis were hexokinase, phosphofructokinase, and glyceraldehyde-3-P dehydrogenase. Heavy platelets contained approximately twofold greater enzyme activity (per gram wet weight) than light platelets for 7 of the 16 enzymes measured: hexokinase, phosphohexoisomerase, phosphofructokinase, glyceraldehyde-3-P dehydrogenase, phosphoglycerokinase, lactic dehydrogenase, and phosphoglucomutase. Heavy platelets also contained 1.9-fold greater reduced glutathione (GSH), 1.7-fold greater DPNH, and 1.2-fold greater TPNH than light platelets. Heavy platelets contained 1.8-fold less lipid peroxidation products (malonyl aldehyde equivalents) than light platelets and were 2.4-fold more resistant to lipid peroxidation catalyzed by 0.1 mM FeCl(3). Sterile incubation of heavy platelets, in vitro for 17 hr, resulted in a significant loss of enzyme activity for the "elevated" seven enzymes when compared with the remainder. Reducing agents such as GSH (0.1 mM), ascorbic acid (0.1 mM), and dithiothreitol (0.01 mM), when added to the incubation mixture, significantly reduced the in vitro loss of activity. In vitro incubation was also associated with a significant loss of GSH and DPNH and a 1.8-fold increase in lipid peroxidation products.
Explore the source record for details and available documents.
The effects of thyroxine and 5 alpha-dihydrotestosterone on the activities of various marker enzymes in the submandibular glands of immature mice were studied. The responsiveness to thyroid hormone appeared at latest by day five after birth, which was ten d earlier than the appearance of androgen responsiveness. The activity of trypsin-like esteroprotease, however, was not increased by these hormones until day 15 after birth.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.