Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transport of glutamine by brush-border vesicles prepared from the renal cortex was studied. The transport system had both Na+-dependent and Na+-independent components. The presence of Na+ in the incubation resulted in an 'overshoot' at 30s at which time the rates of transport were approx. 8 times the values obtained in the absence of Na+. Variation of the glutamine concentration showed that the system obeyed Michaelis-Menten kinetics with Km and Vmax. values for the Na+-dependent system of 0.86 mM and 9.6 nmol/min per mg of protein respectively. Vesicles obtained from chronically acidotic rats showed similar kinetic characteristics. The Km and Vmax. values for the Na+-dependent system were 0.76 mM and 9.6 nmol/min per mg of protein respectively. There was increased uptake of glutamine by vesicles from acidotic rats and this increase was associated with increased activity of gamma-glutamyltransferase in these preparations. Vesicles from acidotic rats, however, showed no increase in glucose transport and no increase in the activity of maltase, another brush-border enzyme.
 ...
PMID:Transport of glutamine by rat kidney brush-border membrane vesicles. 4 16

The circadian rhythms of sucrase, maltase, isomaltase, trehalase, lactase, gamma-glutamyltransferase, leucylnaphthylamide hydrolyzing activity, alkaline phosphatase and monosaccharide transport were assessed in each fifth of the small intestine of the rat in order to determine if an entire enzyme or transport system population responded in a similar manner or if there were regional differences. Animals were maintained under a light-dark cycle and fed from 1400-1800, EST for 7 days. Functional activities were assessed every 4 h for 24 h, inclusively. Quantitative, and in a few instances, qualitative differences in different areas of the intestine were found for all functions. There were portions of the lactase and alkaline phosphatase populations which displayed no rhythmicity in activity. When rhythmicity was observed there were differences in the activity patterns along the intestine for all functions. Thus, the rhythm patterns obtained from homogenates of the entire small intestine are a composite of the patterns in regions of high average activity. Also, there appears to be a reasonable amount of local control of the various functions.
 ...
PMID:Regional variability in circadian rhythmicity of intestinal digestive-absorptive functions. 4 53

1. alpha-D-mannosidase, beta-D-galactosidase, alpha-L-fucosidase, beta-N-acetylgalactosaminidase, alpha-D-glucosidase and acid phosphatase activities were studied in circulating blood leukocytes from Sus scropha var. domestica L. (pig) and Equus asinus x caballus (mule) by spectrophotometric procedures using p-nitrophenyl derivatives as substrates and three different buffer solutions. 2. The highest specific activity corresponds to acid phosphatase. The specific activities of the glycosidases, all relatively close together in all cases, were low in comparison with that of phosphatase. 3. Generally, each of the above-mentioned enzymes shows one common peak for the pH optimum between 3.5 and 6.0, except alpha-D-glucosidase, which shows two peaks. 4. The pH optima values are generally similar in three buffer solutions employed. 5. Specific activities of the studied enzymes show a parallelism in leukocytes from both pig and mule. Also, this parallelism is observed in their pH optima values. 6. Thermal stability of alpha-D-mannosidase is high whereas that of acid phosphatase is low, in both materials. For other enzymes, differences in the thermal stability was observed according to their source.
 ...
PMID:Comparative study on the activity, pH optimum and thermal stability of some glycosidases and acid phosphatase from pig and mule leukocytes. 4 40

A new series of maltase negative mutants have been isolated from yeast strains carrying the MAL4 gene. These mutants are allelic to the MAL4 gene and fail to ferment maltose, sucrose, and alpha-methylglucoside. Most revertants isolated from these mutants restore the ability to ferment above sugars, and also produce the same levels of maltase as the parental strains. One of the revertants (NA-520-R1), however, ferments maltose slowly, and produces 24 fold less enzyme than the parental strain. Genetic studies revealed that revertant (NA-520-R1), is not a true back mutation but is carrying an extra-genic suppressor, which suppresses the mal4 allele in mutant (NA-520). Since several lines of published evidence indicate that the MAL4 gene is a regulatory gene, it is suggested that the MAL4 gene codes for a regulatory protein, which acts as a positive regulatory element in maltase synthesis.
 ...
PMID:Genetic control of maltase synthesis in yeast. IV. Function of the MAL4 gene: extragenic suppression of a maltase negative mutant. 4 11

Cardiac tissue obtained by left-ventricular endomyocardial biopsy from patients with valvular heart-disease was assayed for marker enzyme activities of subcellular organelles and these were correlated with left ventricular function as assessed by haemodynamic studies. In patients with poor left ventricular function, calcium-dependent adenosine-triphosphatase (A.T.P.ase) activity, predominantly localised to the myofibrils, was strikingly reduced. Activity of lactate dehydrongenase, a cytosol enzyme, was significantly increased in tissue from patients with poor left ventricular function. The activity of enzymes associated with sarcolemma (5'-nucleotidase), mitochondria (glutamate dehydrogenase and monoamine oxidase), microsomes (neutral alpha-glucosidase), and lysosomes (acid phosphatase, N-acetyl-beta-glucosaminidase) was no different in patients with good or poor left ventricular function. It is suggested that reduced myofibrillary A.T.P.ase concentration is the biochemical basis for the impaired ventricular function.
 ...
PMID:Enzymic analysis of cardiac biopsy material from patients with valvular heart-disease. 5 85

Intestinal metaplasia is often associated with human gastric carcinoma. Intestinalization seems to be a typical example of abnormal differentiation and is possibly a precancerous state. For investigation of intestinal metaplasia, a method for visualizing disaccharidases using Tes-Tape was developed; this method was applied to many specimens of stomach surgically removed for the treatment of gastric carcinoma. More than 130 specimens of human stomach were investigated. Intestinalization was classified into types I and II intestinal metaplasia. In type I intestinal metaplasia, sucrase, maltase, trehalase, alkaline phosphatase, goblet cells, and Paneth cells were present; while the type II intestinal metaplasia, sucrase and maltase were present but alkaline phosphatase and trehalase were absent. In type II, goblet cells were present but not Paneth cells. The histochemical technique for sucrase was newly devised. Some of the villi with goblet cells in the area of intestinalization in the stomach were not stained by sucrase activity, although most of the villi were stained. The presence of a third type of metaplasia was suggested. Purified sucrases obtained from the intestine and one case of type I intestinal metaplasia showed blood group reactivity due to the oligosaccharide side chain. However, purified sucrases obtained from two cases of type II intestinal metaplasia were negative in blood group reactivity. A close relation between distribution of alpha-fetoprotein and carcinoembryonic antigen in gastric carcinoma and that in surrounding intestinal metaplasia is discussed.
 ...
PMID:Precancerous changes in the stomach. 5 22

The mild, generalized myopathy (glycogenosis type II) of a 23-year-old male, previously thought to have progressive muscular dystrophy, was studied clinically, electro-myographically, biochemically and with light- and electron microscopes. However, the history and clinical aspects, as well as the registration of high frequency discharges in the electromyogram first made the diagnosis uncertain. This kind of spontaneous activity has been found in nearly all cases reported in the literature. Light microscopic and histochemical examinations show vacular degeneration and glycogen storage in muscle fibres. With the electron microscope we found free dispersed glycogen in the cytoplasm and membrane-bound glycogen, glycogen-filled lysosomes. Biochemical measurements of the muscle enzymes, involved in the glycogen breakdown, were normal except for acid alpha-1,4-glucosidase, which was deficient. The evidence of these findings in this abortive form of glycogenosis type II is discussed and compared with the few cases found in the literature.
 ...
PMID:The symptomatology, morphology and biochemistry of glycogenosis type II (Pompe) in the adult. 5 76

Four cultures of a Candida sp. that lacked alpha-glucosidase activity were isolated from clinical specimens. Physiological, morphological, and serological characterizations of the yeasts and deoxyribonucleic acid reassociation studies supported their classification as a variant of C. tropicalis.
 ...
PMID:Sucrose-negative variants of Candida tropicalis. 6 25

Dog enterocyte brush border proteins have been studied after a 75% proximal resection of the small bowel. This study was carried on microvillar membrane preparations purified from ileal mucosa sampled before and after regeneration on neighbouring intestinal segments, each animal acting as its own control. After six weeks of regeneration a statistically significant decrease of the following enzyme specific activities was observed: lactase, cellobiase, maltase, sucrase, palatinase, dextranase, trehalase, alkaline phosphatase, aminopeptidase and gamma-glutamyl transferase. Analysis of brush border proteins by polyacrylamide gel electrophoresis in presence of sodium dodecyl sulphate have shown after regeneration a decreased rate for the proteins with a molecular weight higher than 100,000 daltons. Modifications of electrophoretic patterns seem to be related to the specific activity decreases observed for brush border enzymes after regeneration, since the molecular weight of these enzymes were found between 116,000 and 285,000 daltons, after gel filtration.
 ...
PMID:Effect of massive proximal small bowel resection on intestinal brush border membrane proteins in the dog. 8 27

The survival and prognosis of the prematurely born human infant are dependent on a successful transition from the intrauterine to the extrauterine environment. This is largely a consequence of the maturation of sufficient gastrointestinal function to provide adequate nutrition. However, the gastrointestinal tract of the premature infant, and to some extent, of the full-term infant, may be unprepared to provide the requisite absorptive function. Data presented in this symposium emphasize the dissociations in the development of human gastrointestinal function. Morphological maturation is completed early in gestation while glucose absorption increases with gestational age. Sucrase and maltase activities appear early; lactase activity begins to increase at 30 weeks and increases steadily to term. The latter pattern is accompanied by increased production of cortisol and thyroid in the fetus. The intraluminal phase of fat digestion is immature even in the full-term neonate. Both pancreatic secretory function and bile salt metabolism mature postnatally. Despite this relative immaturity, breast milk fat is absorbed with great efficiency by the term infant, and breast milk provides other important influences on intestinal development: mitogenic factor, immunological support, control of intestinal flora. The goals of nutrition support of the premature infant have been to maintain intrauterine growth standards; yet premature infants receiving pooled breast milk from mothers at 40 weeks or more may be given too little protein for their needs. Human milk from mothers of premature infants may be a more appropriate nutrient source. Supplements with higher contents of amino acids may lead to amino acid imbalance or hyperammonaemia. Additional stresses and requirements are imposed by illness or congenital anomalies. While we must apply current research findings to clinical care, we must also extend our knowledge of extrauterine human development. The ultimate measure of success in this field will be the physical and neurological capacities of infants followed prospectively.
 ...
PMID:The immature intestine: implications for nutrition of the neonate. 9 85


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>