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At least 1,729 records · Page 96Linked to original sources
PubMed1993

alpha-Amylase, a flour additive: an important cause of protein contact dermatitis in bakers.

BACKGROUND: alpha-Amylase, an enzyme commonly used in flour additives, has been reported to be an important cause of rhinitis and asthma in bakers. OBJECTIVE: Our purpose was to determine whether this enzyme could also cause dermatitis. We tested it routinely in bakers with hand eczema. METHODS: Patch tests were administered with the International Contact Dermatitis Research Group standard series and a bakery series and scratch-chamber or prick tests were performed with the bakers' own material and with alpha-amylase powder. RESULTS: Of 32 bakers tested, seven had an immediate wheal-and-flare reaction and two also had a delayed eczematous reaction. High dilutions of the alpha-amylase powder still gave strong reactions. CONCLUSION: alpha-Amylase is an important cause of skin reactions in bakers and should be tested routinely if a contact allergy is suspected.

Adult↗
PubMed1990

Regulation of a thermostable alpha-amylase of Streptomyces thermoviolaceus CUB74: maltotriose is the smallest inducer.

We have examined induction and repression by various sugars and carbon sources of the synthesis of a thermostable alpha-amylase in its natural host, S thermoviolaceus CUB74. The smallest molecule capable of inducing synthesis of the enzyme was maltotriose whereas maltose had no effect which might suggest a different control system from that found in other streptomycete amylases. Addition of mannitol to the growth medium impeded the alpha-amylase induction whereas glucose had no effect. After cloning of its gene into a new streptomycete host, S lividans TK24, the S thermoviolaceus alpha-amylase could not be induced by any of the sugars tested.

Enzyme Induction↗
PubMed1975

The significance of amylase in forensic investigations of body fluids.

Amylase levels in body fluids are reported, and it is shown that high amylase levels may occasionally occur in body fluids other than saliva. Low amylase levels are reported in a saliva component which has been previously described as being rich in blood group active material. The use of amylase activity in the localisation and identification of saliva is discussed in detail and guidelines for the interpretation of results are proposed.

Amylases↗
PubMed1986

Ontogeny of alpha-amylase circadian rhythms in rat parotid gland.

The content of alpha-amylase (alpha-1,4-glucan-4-glucanohydrolase, EC 3.2.1.1.) and total soluble proteins of parotid glands (from rats exposed to a photoperiod of 14 hr light: 10 hr dark), have been determined every 2 or 3 hr over 24 hr periods in 15, 25 and 90-day-old rats. In 35-, 45- and 72-day-old rats, determinations were performed only at 0100 and 1400 hr. The alpha-amylase and total soluble protein contents from 90-day-old rats show a circadian variation, with a maximum value at 2200 hr and a minimum at 1400 hr. Parotids from 15- and 25-day-old rats also show a circadian rhythm. The minimum value is recorded at 0100 hr and the maximum at 1400 hr. At day 35 and after, there is an inversion of the amylase rhythm. In immature rats, it appears that alpha-amylase and soluble protein are under the influence of another synchronizer, whose timing is independent of that imposed by mastication of solid food.

Aging↗
PubMed1991

Identification and properties of an alpha-amylase from a strain of Eubacterium sp. isolated from the rat intestinal tract.

1. A bacterial amylase was isolated from the intestinal content of monoxenic rats inoculated with Eubacterium sp. B86. 2. Affinity chromatography on cross-linked starch allowed its separation from rat endogenous amylases. 3. The bacterial enzyme was characterized by its pI, molecular weight and action pattern. It behaves as a typical endo-amylase (alpha-amylase).

Animals↗
PubMed1976

Premature induction of amylase in pancreas and parotid gland of growing rats by dexamethasone.

Studies were made on changes in the contents of alpha-amylase (EC 3.2.1.1) in the pancreas and parotid gland of rats during postnatal development, on the premature induction of this enzyme by hormones and on the existence of specific glucocorticoid receptors in these tissues. The amylase content in the pancreas increased from the 9th day after birth and reached the adult level on the 28th day, its content in the parotid gland increased rapidly from the 16th to the 28th day after birth and then rose more gradually to the adult level. Injection of dexamethasone into rats 6--8 days after birth induced increase in the amylase of the pancreas but not the parotid gland. However, injection of dexamethasone into weanling rats 21--23 days after birth resulted in precocious induction of amylase in both tissues. Specific glucocorticoid receptors were detectable in the parotid gland of rats from 6 days after birth but were almost undetectable in the pancreas until adolescence.

Aging↗
PubMed1976

Effect of adenosine 3',5'-cyclic monophosphate derivatives on alpha-amylase release, protein kinase and cyclic nucleotide phosphodiesterase activity from rat parotid tissue.

Several 8-substituted derivatives of cyclic AMP were tested for their effects on alpha-amylase release. None of the 8-substituted compounds were more active than N6,O2-dibutyryl- or N6-monobutyryl adenosine 3',5'-monophosphate in causing alpha-amylase release. The rat parotid was found to contain a high (105 muM) and a low (1.15 muM) Km cyclic AMP phosphodiesterase activity. All of the 8-substituted cyclic AMP compounds inhibited the hydrolysis of 1 muM cyclic AMP. However, there was only a partial correlation between the ability to cause alpha-amylase release and inhibit cyclic AMP hydrolysis. Extracts of parotid tissue contained a cyclic AMP-dependent protein kinase activity. None of the compounds were as effective as cyclic AMP in activating the protein kinase. As in the case of inhibition of cyclic AMP hydrolysis, the ability of the 8-substituted cyclic AMP compounds to increase protein kinase activity did not correlate with their effects on alpha-amylase release. It is concluded that factors in addition to the in vitro inhibition of cyclic AMP hydrolysis and activation of protein kinase are important in determining the net result of the 8-substituted cyclic AMP compounds on parotid gland function. These additional factors might include differences in the rate of uptake and differences in rats of conversion to compounds with modified activity.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1977

Perinatal changes in amylase and serum corticosterone levels in rats.

In rats amylase activity in the pancreas increased greatly from day 15 of gestation to a maximum on day 21. Then it decreased to less than one-tenth of this maximum value on about day 5 after birth. It increased again about 15 days after birth and reached the adult level about 30 days after birth. No amylase activity was in the parotid gland before birth: it appeared about 12 days after birth and reached the adult level, which was higher than that in the pancreas, about 30 days after birth. The serum corticosterone level was as high as the adult level before birth. Then it decreased to less than one-tenth of the adult level 5 days after birth and increased again from 15 to 25 days after birth to the adult level. The developmental change in the serum corticosterone level seemed to influence amylase activity in the pancreas both before and after birth, and that in the parotid gland only after birth. The serum contained both pancreatic and parotid type isozymes of amylase until 1 day after birth but only the parotid type from 3 days after birth.

Aging↗
PubMed1979

Amylase release from rat parotid glands. II. Calcium kinetics.

The kinetics of 45Ca2+ uptake, efflux, and calcium potentiation of amylase release by slices of rat parotid glands were examined. Pretreatment of the tissue with 11.25 mM 45Ca2+ medium increased the total tissue 45calcium content. Lanthanum (1 mM) decreased tissue uptake, blocked the slow components of exchange and appeared to inhibit transcellular calcium movement. Neither dibutyryl cyclic AMP nor caffeine caused consistently significant effects on 45Ca2+ kinetics, or total 45calcium content. Carbamylcholine increased the initial rate of 45Ca2+ uptake, but had no effect on total uptake. Elevation of the extracellular Ca2+ concentration to 11.25 mM during stimulation of amylase release resulted in an initial decrease in the rate of amylase release followed by a potentiation of release which developed slowly, requiring 40--50 min to reach the maximal response. The inability to detect release-related changes in either calcium influx or mobilization, and the lengthy times and high Ca2+ concentrations required to achieve calcium potentiation suggests that calcium does not couple amylase release.

Amylases↗
PubMed1983

Evidence that amylase is released from two distinct pools of secretory proteins in the pancreas.

Previous experiments demonstrated the existence of at least two pools of secretory proteins in the exocrine pancreas. We have measured the specific activities of amylase released under resting conditions and of amylase in the zymogen granules. Specific activity of resting secretion was twice that found under stimulated conditions or in zymogen granules. Secretory proteins were pulse-labeled and amylase was measured after precipitation of the enzyme with glycogen. Pancreatic juice collected at 45-50 min post-pulse contained 10-25-times the amylase activity found in zymogen granules. These results confirm the existence of at least two distinct pools of secretory proteins in the exocrine pancreas and suggest the existence of an intracellular route of secretory proteins which would bypass the zymogen granule compartment.

Amylases↗
PubMed1979

Amylase levels in the tissues and body fluids of the domestic cat (Felis catus).

1. The amylase activities of serum, liver, pancreas, submaxillary and parotid glands, saliva, duodenum, colon, lung, heart, spleen, kidney and skeletal muscle of the domestic cat, were determined. 2. As in most mammals, the highest amylase content was found in the pancreas. Levels in saliva and salivary glands were very low. 3. Amylase activities of the serum, liver and pancreas have an optimum pH 7.0-7.5. 4. Amylases of serum, liver and pancreas were inactivated by removal of chloride and these activities mainly restored by addition of chloride.

Amylases↗
PubMed1988

Isozymes of alpha-amylase in the porcine pancreas: population distribution.

1. Three isozymes of pancreatic alpha-amylase, PPA 1, PPA 2, and PPA 3, were observed in a porcine population of 50 animals. 2. Isozyme PPA 2 was common to each pancreas. 3. Three phenotypic patterns were described as: (A) consisting of PPA 2 alone (20%); (B) consisting of PPA 1 and PPA 2 (78%); and (C) consisting of all three forms (2%). 4. Amylase isozymes were separated by anion exchange chromatography using DE53. 5. Individual isozymes corresponded to one of the three isozymes found in pancreatin. 6. Individual isozymes were inhibited equally by an amylase inhibitor from wheat. 7. Differences in amylase isozymes were attributed to genetically controlled mechanisms and not to artifacts of isolation.

Animals↗
PubMed1987

Description of an automated assay for measurement of alpha-amylase in vitro from rat parotid gland slices.

1. A modified continuous assay of alpha-amylase is detailed and its usefulness in measuring amylase secretion from rat parotid salivary gland described. 2. The alpha-amylase secretion from the rat parotid gland can be evoked by acetylcholine, substance P and isoprenaline. 3. The secretion of amylase was greatest following isoprenaline stimulation and was of a slower time course than with the other two agonists.

Acetylcholine↗
PubMed1984

Corrected sequences of cDNAs for human salivary and pancreatic alpha-amylases [corrected].

The nucleotide sequences of the cloned human salivary and pancreatic alpha-amylase cDNAs correspond to the continuous mRNA sequences of 1768 and 1566 nucleotides, respectively. These include all of the amino acid coding regions. Salivary cDNA contains 200 bp in the 5'-noncoding region and 32 in the 3'-noncoding region. Pancreatic cDNA contains 3 and 27 bp of 5'- and 3'-noncoding regions, respectively. The nucleotide sequence homology of the two cDNAs is 96% in the coding region, and the predicted amino acid sequences are 94% homologous. Comparison of the sequences of human alpha-amylase cDNAs with those previously obtained for mouse alpha-amylase genes (Hagenbuchle et al., 1980; Schibler et al., 1982) showed the possibility of gene conversion between the two genes of human alpha-amylase.

Amino Acid Sequence↗
PubMed1991

Separation and characterization of sialic acid-containing salivary-type amylase from patients' sera with immunoglobulin A-type myeloma.

Isoamylases, with an abnormal anodic migration, were detected by an electrophoretic technique in the sera from two patients with immunoglobulin A-type myeloma. The abnormal isoamylase bands migrate towards the anode faster than the salivary isoamylase (S2) band and were stained more strongly than the S2 sub-band. The abnormal isoamylase could be separated from patients' sera by using size-exclusion high-performance liquid chromatography. The serum abnormal isoamylases were showed to be sialic acid residues containing amylase, after the study of treatment with neuraminidase (EC 3.2.1.18), and to be salivary-type amylase, after the study of reaction with human salivary monoclonal antibody. The abnormal bands were not detected in the saliva from one patient. The two patients had no detectable malignancies except myeloma. These findings strongly suggest that the sialic acid-containing salivary-type amylases were produced ectopically from myeloma cells. In this regard the ectopic amylase production by myeloma cells is discussed.

Aged↗
PubMed1996

Chromatographic methods for amylases.

This review surveys recent developments in chromatographic methods for the separation of amylases from complex extracts, including the separation of isozymes. It contains two tables with the properties and molecular characteristics of alpha-and beta-amylases from different sources as well as an updated review of methods for the determination of amylase activity. The main subject of this review is a detailed evaluation of the application of newly developed chromatographic methods for the purification of amylases.

Amylases↗
PubMed1988

Serum amylase levels in ectopic pregnancy.

Thirty-four women with abdominal complaints and a positive pregnancy test were evaluated for possible ectopic pregnancy (EP). Serum amylase levels were obtained as part of the diagnostic workup to note any correlation of enzyme levels with the presence of EP. Thirteen individuals (30%) were subsequently diagnosed as having an EP, and serum amylase levels in all of these patients were within normal limits, averaging 81 U/L. There was no statistically significant difference in amylase levels between the EP group and the non-EP group (P = .70). Serum amylase levels cannot reliably predict the presence of EP and should not be used as a screening or diagnostic test for this disorder.

Adolescent↗
PubMed1994

Normal amylase levels in the presentation of acute pancreatitis.

Recent literature suggests that serum amylase levels are not an appropriate screen for the diagnosis of acute pancreatitis because specificity and sensitivity are poor. Evidence from several studies supports the use of lipase determinations to diagnose acute pancreatitis, and recent improvements in this assay have made it more readily available to the emergency physician. This retrospective review compares the use of serum amylase to lipase levels in the diagnosis of acute pancreatitis in 52 patients who presented to the emergency department, with the hospital discharge diagnosis serving as the gold standard to which the assays were compared. Serum lipase was found to be more sensitive than serum amylase (95% vs 79%); serum amylase levels decreased to normal significantly faster than lipase levels.

Acute Disease↗