Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.20 (alpha-glucosidase)
4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to investigate the role of renal factors in affecting trypsinogen 1 metabolism and excretion in chronic pancreatic disease, serum immunoreactive trypsin (IRT), urinary IRT, gamma-glutamyltransferase (GGT), alpha-glucosidase (AGL) and RNase outputs and the molecular size distribution of serum and urine IRT were studied in 8 control subjects, 18 cases with pancreatic cancer, and 23 cases with chronic pancreatitis. Serum chromatography demonstrated that most immunoreactivity eluted as trypsinogen 1. Smaller amounts of immunoreactivity at higher molecular weights were also observed. Urine chromatography displayed both trypsinogen 1 and heavier molecular forms. An inverse linear correlation was noticed between creatinine clearance and serum trypsinogen 1 levels. Multiple regression analysis (urinary IRT output dependent and GGT, AGL, and RNase predictor variables) showed a significant linear correlation. RNase was found to be the most important parameter in explaining urinary IRT output. Mild variations in the glomerular function seem to be able to influence serum trypsinogen 1 levels. Urinary IRT excretion is principally explained by a disturbance in the tubular reabsorption of low molecular weight proteins, such as RNase.
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PMID:Renal factors in serum trypsinogen 1 metabolism and excretion in chronic pancreatic disease. 336 41

The reformation of functioning organelles at the end of mitosis presents a problem in vesicle targeting. Using extracts made from Xenopus laevis frog eggs, we have studied in vitro the vesicles that reform the nuclear envelope. In the in vitro assay, nuclear envelope growth is linear with time. Furthermore, the final surface area of the nuclear envelopes formed is directly dependent upon the amount of membrane vesicles added to the assay. Egg membrane vesicles could be fractionated into two populations, only one of which was competent for nuclear envelope assembly. We found that vesicles active in nuclear envelope assembly contained markers (BiP and alpha-glucosidase II) characteristic of the endoplasmic reticulum (ER), but that the majority of ER-derived vesicles do not contribute to nuclear envelope size. This functional distinction between nuclear vesicles and ER-derived vesicles implies that nuclear vesicles are unique and possess at least one factor required for envelope assembly that is lacking in other vesicles. Consistent with this, treatment of vesicles with trypsin destroyed their ability to form a nuclear envelope; electron microscopic studies indicate that the trypsin-sensitive proteins is required for vesicles to bind to chromatin. However, the protease-sensitive component(s) is resistant to treatments that disrupt protein-protein interactions, such as high salt, EDTA, or low ionic strength solutions. We propose that an integral membrane protein, or protein tightly associated with the membrane, is critical for nuclear vesicle targeting or function.
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PMID:A trypsin-sensitive receptor on membrane vesicles is required for nuclear envelope formation in vitro. 339 6

Procedures have been validated for the investigation of the physical properties of canine microvillar membrane proteins by SDS-polyacrylamide gel electrophoresis. These have been used to examine mucosal samples from eight control dogs and from five dogs with naturally occurring exocrine pancreatic insufficiency (EPI) in order to evaluate the potential role of the pancreas in the normal turnover of microvillar membrane proteins in the dog. Gel scanning showed that the proportion of total membrane protein in bands corresponding to a molecular mass greater than 200 kDa was up to 20-times higher in dogs with EPI than in control dogs. In particular, a band of apparent molecular mass 218 kDa represented between 8 and 28% of membrane protein in all affected dogs, compared with only 0.5 to 1.8% in controls, and is most likely to contain single chains of both pro-maltase-glucoamylase and pro-sucrase-isomaltase. Incubation of microvillar membranes in vitro with either trypsin or canine pancreatic juice resulted in degradation of this high molecular mass band and a corresponding increase in the amount of protein in three bands representing molecular masses of 150, 133 and 106 kDa. In samples from control dogs aminopeptidase N was identified in the 133 kDa band by Western blotting and incubation with monospecific antiserum. These findings suggest that pancreatic enzymes play a major role in the normal post-translational processing of intestinal microvillar membrane proteins in the dog.
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PMID:Investigation of the physical properties of dog intestinal microvillar membrane proteins by polyacrylamide gel electrophoresis: a comparison between normal dogs and dogs with exocrine pancreatic insufficiency. 340 88

API ZYM and API An-Ident enzymatic substrate tests were done on six oral species which are difficult to characterize with conventional biochemical tests. "Bacteroides forsythus, the "fusiform" Bacteroides species (A. C. R. Tanner, M. A. Listgarten, M. N. Strzempko, and J. L. Ebersole, manuscript in preparation), is difficult to cultivate in broth media, yet it gave 15 positive tests in these series. The tests were able to separate this new species from species of Capnocytophaga and Fusobacterium. "B. forsythus" reactions were similar but not identical to those of reference Bacteroides species. Positive reactions for alpha-glucosidase, beta-glucosidase, alpha-fucosidase, and alpha-glucuronidase suggest that "B. forsythus" may be saccharolytic. It was the only species tested which was trypsin positive. Wolinella species, Campylobacter concisus, B. gracilis, and Eikenella corrodens are asaccharolytic, and characterization relies heavily on sensitivities to inhibitory agents. These species reacted weakly in the API ZYM and API An-Ident enzymatic substrate tests, and the reactions were not useful for separating these species. The enzyme reactions differentiated Wolinella recta and C. concisus from Selenomonas sputigena, another oral motile but saccharolytic organism.
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PMID:API ZYM and API An-Ident reactions of fastidious oral gram-negative species. 393 May 58

Trypsin/creatinine clearance ratio--a recently proposed screening test for pancreatic cancer--was assessed in 45 subjects (17 control subjects, 15 patients with pancreatic cancer, and 13 with chronic pancreatitis). A statistically significant increase of the ratio was detected not only in pancreatic cancer, but also in chronic calcifying pancreatitis. Thus, the previously reported clinical usefulness of the test in pancreatic cancer diagnosis was not substantiated by the present data. Although not fully investigated as yet, reasons for an abnormal ratio are probably independent of the neoplastic or inflammatory nature of the pancreatic disease. Science renal enzyme excretion (alpha-glucosidase, gamma-glutamyltranspeptidase, leucine aminopeptidase) was not found to be invariably elevated when trypsin/creatinine clearance ratio was increased, tubular damage cannot be assumed as constituting the only reason for an altered clearance ratio.
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PMID:Role of trypsin/creatinine clearance ratio in the differential diagnosis of chronic pancreatic disease. 616 44

In the pigeon, 70-80% of the activities of maltase (alpha-D-glucoside glucohydrolase EC 3.2.1.20), sucrase (alpha-glucohydrolase, EC 3.2.1.48), isomaltase (dextran 6-alpha-D-glucan hydrolase, EC 3.2.1.10) and glucoamylase (1,4-alpha-D-glucan glucohydrolase, EC 3.2.1.3) were found to be localized in the brush-border membrane of intestinal epithelial cells. Of the total glycosidase activities in the mucosal homogenate, nearly 60 to 70% were recovered in the microsomal (105 000 X g) fraction, about 30% in the mitochondrial (22 000 X g) fraction and less than 5% from the cytosol (105 000 X g supernatant) fraction. The hydrolases were solubilized by digestion with papain but not with trypsin, and the phosphate ion had a protective effect in the solubilization. Amongst detergents, Triton X-100 but not sodium deoxycholate, was found to truly solubilize these enzymes.
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PMID:Studies on the intestinal disaccharidases of the pigeon. II. Subcellular localization and solubilization. 618 28

The action of certain substances known to induce cellular alterations, or encounted in the oral cavity, on the accumulation of 18F by Streptococcus mutans GS-5 has been investigated. A 62-67% inhibition in the number of 18F atoms bound per mg dry weight of cells could be induced by a 15 min pretreatment with 2.7 X 10(-4) M cetyltrimethylammoniumbromide, 1 X 10(-1) M acetic anhydride, or 7 X 10(-2) M HCl. Plate counts indicated that alteration of the cellular composition rather than viability was responsible for this diminution in 18F accumulation. Prior exposure for 15 min of this organism to 1 M HCHO or 0.1 M NaOH did not alter 18F accumulation. Of the common salts encountered in the oral cavity, CaCl2 enhanced 18F binding. Pretreatment of the assay cells for 15-160 min with 0.1-10 mg/ml of trypsin, pronase, protease, alpha-glucosidase, dextranase, or lactoferrin had no significant effect on the accumulation of 18F. However, pre-exposure of cells for 60 min to 1-10 mg/ml of either amylase or lipase induced a 40-67% inhibition in the binding of 18F, while lysozyme enhanced the binding of 18F by the cells. It would appear then that the binding of 18F by S. mutans may be altered by certain substances encountered in the oral cavity.
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PMID:The action of selected agents on the accumulation of 18F by Streptococcus mutans. 618 42

The results presented show striking differences in the response of the exocrine pancreas to fasting in suckling versus adult rats. In adult rats, fasting led to an increase in lipase to amylase ratio with a particularly sharp decrease in amylase concentrations, a generalized decrease in total protein, amylase, trypsinogen and lipase contents, and a decrease in responsiveness of the pancreatic acini to optimal and supraoptimal concentrations of secretagogues in vitro. In 15 day old pups, however, fasting led to an increase in total amylase, trypsin and lipase and a maintenance of the total protein content in their pancreases. Further, no decrease in responsiveness of their pancreatic acini to secretagogue stimulation is observed at the concentrations studied. The difference in the behavior of the exocrine pancreas during fasting can be partly explained by the changing pattern of their responses to hormonal stimulation, particularly that of corticosterone and cholecystokinin during various stages of development. Fasting led to an increase in corticosterone and presumable decrease in cholecystokinin. The pancreas of the suckling rat is very sensitive to the induction effect of corticosterone while that of the adult rats is relatively insensitive. Conversely, the pancreas of the adult rats is sensitive to the trophic effect of cholecystokinin while that of the suckling rat has the opposite reaction. The combination of these and other factors then resulted in an entirely different profile of the responses of the exocrine pancreas to fasting. Recent studies in our laboratory, and that of others, showed that an analogous situation also existed in the small intestine. Fasting of adult rats led to a general decrease in small intestinal enzymes including sucrase and maltase (29) but in suckling rats led to (30,31) increases of sucrase and maltase. Corticosterone again has been shown to be involved (30,31). Further, the small intestinal sucrase of the suckling rats responded to corticosterone by an increase in its level but the same hormone did not seem to control the sucrase concentrations in the small intestine of adult rats (32,33). Thus, both the small intestine and the pancreas responds very differently to fasting presumably mediated through a varying pattern of responses to selective hormonal stimulation, eg in this case, corticosterone. These results strongly suggest the importance of the interaction between environmental influences (fasting in this case) and the stage of development in determining the outcome of ontogenesis.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Response of the pancreas to fasting: adult versus neonates. 620 75

The possibility that pancreatic secretory abnormalities might precede the appearance of pancreatic neoplasms and thus provide clues to early detection of this malignancy has been investigated in an animal model. Syrian golden hamsters were treated with bis-(2-oxopropyl)-N-nitrosamine on two successive weeks (2 mg/100 g body weight/week). Pancreatic secretions from treated and untreated control animals were studied at approximately monthly intervals. The animals were anesthetized, their pancreatic ducts cannulated, and basal pancreatic juice collected for 30 min. Pancreatic secretion was then stimulated by sequential intravenous injection of secretin (50 ng/100 g) and C-terminal octapeptide of cholecystokinin (4 ng/100 g) 1 hr later. Four consecutive 15-min collections of fluid were made following secretin stimulation and four additional collections after CCK administration. Each collection was examined for volume, total protein, trypsin, chymotrypsin, elastase, arylsulfatase, beta-D-glucuronidase, alpha-D-glucosidase, and leucine naphthylamidase. In addition two trypsinogen variants present in pancreatic secretions were determined. The pancreas and other organs were removed and examined histologically at the end of each experiment. Cytological atypia appeared 3 months, ductal hyperplasia 4 months, and pancreatic neoplasms 6 months after the last injection of carcinogen. Striking decreases in flow rate and output of trypsin and chymotrypsin were observed several months prior to the appearance of histologically recognizable pancreatic tumors. By contrast, output of beta-D-glucuronidase and alpha-D-glucosidase in pancreatic juice increased markedly in the last 2 months preceding the emergence of neoplasms. The diagnostic significance of these premalignant abnormalities is illustrated most dramatically in the form of ratios of lysosomal to digestive enzymes, such as beta-D-glucuronidase-trypsin or alpha-D-glucosidase-chymotrypsin. Highly significant increases in these ratios were observed consistently, not only in hamsters with pancreatic neoplasms, but also in animals with preneoplastic lesions (ductular hyperplasia) which preceded malignancies by about 2 months.
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PMID:Pancreatic secretory abnormalities precede appearance of tumors of the pancreas in hamsters treated with bis-(2-oxopropyl)-N-nitrosamine. 630 6

After twenty weeks of continuous dosing with Trichostrongylus colubriformis larvae substantial, but declining, numbers of worms had persisted in most of the lambs examined, although there were wide inter-individual variations. Mucosal lesions were found in the proximal small intestines of all the infected animals, their severity being directly related to worm burden. Representative brush border enzyme activities analysed in intestinal mucosal extracts from the same lambs showed differing responses. Alkaline phosphatase and glycyl-L-leucine dipeptidase were significantly depleted, whereas maltase activity was only marginally reduced, and leucine aminopeptidase activity was normal. Mucosal acetylcholinesterase activity was significantly elevated in the parasitised animals and, interestingly in view of the postulated role of this enzyme in nematode pathogenicity, the level of activity was directly correlated with individual worm burdens. Intestinal trypsin and chymotrypsin activities were unaffected and the level of superoxide dismutase, an enzyme associated with the inflammatory response, was normal. There were also no consistent changes in the mucosal activities of several enzymes including lactic dehydrogenase, creatine phosphokinase, aldolase, and glutamic oxaloacetate transaminase, whose leakage from damaged or necrotic tissues has been well defined in terms of the concomitant increase in their activity in the circulation. Lambs treated orally with fenbendazole five and/or ten weeks before slaughter either in the presence or absence of continued larval intake, had negligible worm burdens, and showed little evidence of intestinal damage at post mortem. Brush border enzyme levels, with the exception of alkaline phosphatase and, in two cases dipeptidase, were normal in these animals. The activity of alkaline phosphatase was approximately double that in the continuously infected, untreated lambs, but remained markedly lower than in the uninfected controls. The activities of the other enzymes studied, including acetylcholinesterase, were within the control range. In summary, in chronic trichostrongylosis even relatively low nematode burdens were associated with marked pathological and biochemical damage in the intestine with both lesion severity and mucosal acetylcholinesterase activity being directly related to worm numbers. Although morphological integrity was completely restored after anthelmintic treatment, the persistent low activity of brush border alkaline phosphatase coupled with the enzymological findings in untreated, infected animals suggests that recovery of the full functional capability of the intestinal mucosa may take longer.
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PMID:Intestinal enzyme activity in lambs chronically infected with Trichostrongylus colubriformis: effect of anthelmintic treatment. 634 11


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