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PubMed1989

Alpha-amylase determination with the Reflotron reagent carrier system: use of whole blood, plasma, and serum, and effect of isoenzymes.

In the Reflotron Amylase dry-reagent carrier system (Boehringer Mannheim GmbH) a new substrate is used for determining total amylase (EC 3.2.1.1) activity:indolyl-alpha-D-maltoheptaoside. The procedure shows low imprecision (median CV less than 3.2%), and results for sera, plasma, and capillary and venous blood (y) correlate well with those of a conventional alpha-amylase method involving p-nitrophenyl (PNP)-maltoheptaoside substrate (x) (for 209 blood samples: y = 0.981x + 9.7; r = 0.994). Correlation was also excellent with a method involving maltotetraose as substrate (r = 0.987). Attachment of an indoxyl residue rather than a PNP group to the maltoheptaoside did not affect the substrate response to pancreatic or salivary isoenzyme activity. Therefore, the relative proportion of these isoenzymes did not affect the correlation between the Reflotron Amylase reagent carrier and the alpha-amylase PNP-maltoheptaoside method. With a reaction time of less than 3 min, this system is especially suitable for amylase determination in situations where a prompt result is required.

Humans↗
PubMed1988

Expression of alpha-amylase in human lung cancers.

Thirty-three human lung tumors were studied for the expression of alpha-amylase by immunohistochemical and Northern blot analyses. Twenty of them were adenocarcinomas, among which 17 proved to be adequate for mRNA analyses and were, except for two, amylase mRNA producers. Seven were squamous cell carcinomas, none of which produced amylase. The remaining six consisted of two undifferentiated small cell carcinomas, and one each of undifferentiated large cell carcinoma, carcinoid tumor, mucoepidermoid carcinoma, and metastatic lung cancer; the mucoepidermoid carcinoma proved to be an amylase producer. These observations strongly suggest that among lung cancers, the production of alpha-amylase is a property commonly associated with adenocarcinomas and can be used for distinguishing cell types. Histogenesis and carcinogenesis in lung cells are discussed in connection with the cells that produce amylase.

Adenocarcinoma↗
PubMed1988

[Comparison of chemical and thermal stability of soluble and immobilized alpha-amylases from B. licheniformis and A. oryzae].

alpha-Amylases from B. licheniformis and A. oryzae, which differ in their thermal stability, were studied with respect to their resistance to chemical denaturants as guanidine hydrochloride, urea, aliphatic alcohols, and formaldehyde. Moreover, the thermal and chemical stabilities of both enzymes were compared after their covalent binding to gamma-aminopropyl silica. The thermolabile alpha-amylase (A. oryzae) as well as the thermostable alpha-amylase (B. licheniformis) are remarkably stabilized by immobilization. Therefore, the high thermal resistance of the thermophilic enzyme may be further increased. Soluble and immobilized alpha-amylases from B. licheniformis are more resistant to guanidine hydrochloride, urea, methanol, ethanol, propranol, and t-butanol than the alpha-amylases from A. oryzae. Obviously, the high intrinsic stability of the thermophilic enzyme is also valid for chemical denaturation. An exception is given by the effect of formaldehyde, which may result in chemical modifications of the protein molecule. Enzymes from B. licheniformis are more sensitive against formaldehyde than those from A. oryzae. As in thermal inactivation, immobilization protects alpha-amylase from A. oryzae against denaturation by guanidine hydrochloride and urea, but fails in the denaturation by alcohols. Therefore, stabilizing effects in immobilized enzymes are dependent on the kind of denaturant.

Aspergillus↗
PubMed1986

Electrophoretic assays of amylase isoenzymes and isoforms.

Electrophoretic methods provide an effective means for analysis of amylase isoenzymes and isoforms. A wide variety of such techniques have been developed and reflect different applications and analytic objectives of different investigators. Virtually all of the available clinical data on amylase isoenzymes and isoforms has resulted from application of these methods. Recent identification of selective amylase inhibitors and of monoclonal antibodies to amylase isoenzymes holds promise of development of rapid routine clinical assays for amylase isoenzymes. Electrophoretic methods will have an important role in validating these new assays. Furthermore, at the present time, electrophoretic methods provide the best approach for analyzing isoforms of the pancreatic and salivary isoenzymes. This may be clinically important in patients with tumors, pancreatic pseudocysts, or macroamylasemia. Further clinical experience is needed to define the roles of the various assays that are now available for the estimation of amylase isoenzymes and isoforms in human samples.

Blood Protein Electrophoresis↗
PubMed1979

Clinical use of amylase clearance and isoamylase measurements.

Isoamylase determinations and measurements of the ratio of the renal clearance of amylase relative to creatinine (CAm/CCr) were employed in an attempt to improve the diagnostic accuracy of the standard amylase measurement. An elevated CAm/CCr reflects defective proximal tubular reabsorption of amylase which occurs in virtually all patients with clear-cut acute pancreatitis. However, other conditions that apparently are associated with acute defective tubular function, such as burns and diabetic acidosis, may cause an elevated ratio. Thus, elevations of CAm/CCr cannot be considered to be specific for acute pancreatitis. Pancreatic isoamylase represents, on the average, about 33% of the normal serum amylase activity, whereas about 66% is salivary-type isoamylase. Isoamylase measurements are useful in determining whether an elevated value for serum amylase activity is of pancreatic origin. However, this measurement is not useful for determining whether patients with normal serum amylase activity have pancreatitis.

Amylases↗
PubMed1984

Coordinate increase in major transcripts from the high pI alpha-amylase multigene family in barley aleurone cells stimulated with gibberellic acid.

The purpose of this study was to identify specifically genes and transcripts for the high pI isozyme of barley alpha-amylase. From hybridization of coding sequence probes to blots of genomic DNA digested with restriction enzymes that do not cut within our cloned high pI alpha-amylase cDNA, it is estimated that about 7 alpha-amylase genes or pseudogenes exist. No difference could be detected between barley aleurone cell and sprout DNAs. Experiments using probes from the 5' and 3' untranslated sequences of the high pI alpha-amylase cDNA clone identified three HindIII fragments that probably carry high pI sequences. Primer extension experiments used as a primer the terminal 5' coding sequence from our cDNA clone; this primer would not cross-hybridize to low pI alpha-amylase transcripts. Two major transcripts were identified. These shared a conserved 23-base sequence immediately 5' to the ATG start codon, although a C----G transversion and a 3-base deletion were present within this sequence. An unusual 8-base pair GC palindrome was present in the conserved region immediately preceding the ATG start codon. Distal to the conserved sequence there was no apparent homology. One transcript carrying a 97-base untranslated region was identical to our high pI cDNA clone E. The gene for the other was recovered from a lambda phage genomic library. The 5' coding sequence was very similar, but not identical to clone E, demonstrating that these transcripts arise from separate genes. The two transcripts increased coordinately in aleurone cells stimulated with gibberellic acid. These data indicate that there is a high pI alpha-amylase multigene family with at least two active members, both of which are regulated in some manner by the plant hormone gibberellic acid.

Base Sequence↗
PubMed1981

Genetic determination of amylase synthesis in the mouse.

Extensive genetic variation in structure and rate of synthesis of pancreatic amylase has been identified among strains of mice. The relative rate of synthesis of amylase varies from 0.15 in strain YBR to 0.26 in strain C3H. The number of electrophoretic isozymes of pancreatic amylase varies between one and four. In each strain with multiple amylase isozymes, a characteristic quantitative distribution of protein among the isozymes is observed. Isozyme proportions are determined by the relative rates of synthesis of each component. Congenic lines with different amylase phenotypes have been established. Genetic analysis reveals the close linkage of cis-acting sites determining rate of synthesis and electrophoretic mobility of mouse pancreatic amylase.

Amylases↗
PubMed1981

On the mechanism of variation of pancreatic amylase levels in mouse strains.

The relative levels of pancreatic amylase mRNA closely parallel the 3-fold variation of pancreatic amylase protein levels observed in several mouse strains studied. In contrast pancreatic elastase mRNA levels were similar in these strains. Each of the strains contained the same number of amylase-like genes (about 8). The selective variation in the pancreatic amylase gene expression could be due either to differences in the numbers of active amylase genes or to different rates of synthesis and/or degradation of the amylase mRNA from a constant number of genes.

Amylases↗
PubMed1982

Amylase in human milk.

Amylase activity and isoenzyme pattern were determined in human milk from various stages of lactation and were compared with that in duodenal juice. The activity is high in colostrum and somewhat lower in milk from day 15 to day 90 after delivery. In this period of lactation, human milk contains higher amounts of amylase than duodenal juice from infants aged 1 to 6 months. Low activity was found in milk from 90 days or more after delivery. The amylase is of the salivary type. A pH of 5.3 does not inactivate the amylase; there is considerable human milk amylase activity in duodenal juice after a meal of human milk. Human milk amylase could thus contribute to the breast-fed infant's ability to digest starch.

Amylases↗
PubMed1983

Isolation and characterization of a rat amylase gene family.

Portions of at least nine distinct rat amylase genes or pseudogenes have been isolated. Cloned rat genomic DNA fragments containing complete or major portions of seven of these have been examined by heteroduplex analysis and fall within two separate groups based on their degree of homology. Four gene sequences comprising one of these groups are closely related to pancreatic amylase mRNA. The other group shows significant nonhomology to both pancreatic and parotid amylase cDNAs and may represent an additional gene type(s). All of the cloned amylase gene sequences are found in rat genomic DNA. Additional amylase sequences which have not yet been cloned are also detected. Comparison of DNA from individual Sprague-Dawley rats by Southern blotting techniques indicates allelic variation at multiple amylase loci.

Amylases↗
PubMed1983

Suitability of control materials in the differential inhibition assay for human pancreatic and salivary amylase.

We investigated the behavior of 26 quality-control sera with the inhibitor method for differential amylase (EC 3.2.1.1) assay. We also studied the sensitivity to the wheat-derived inhibitor of pancreatic amylases from 10 different animals in comparison with human pancreatic and salivary amylase. The results indicate that only control materials containing human amylases can be measured accurately. The animal amylases (bovine, equine, porcine) used in many quality control sera are relatively insensitive to the inhibitor as compared with human pancreatic and salivary amylase.

Amylases↗
PubMed1983

[Diagnostic value of the determination of serum amylase and serum lipase in suspected acute onset of acute or chronic pancreatitis].

In a prospective study the value of serum amylase and serum lipase determination has been analyzed in 19 patients with an acute episode of acute or chronic pancreatitis and in 19 patients with acute abdomen not due to pancreatitis. The concentration of urinary amylase and the urinary output of amylase in the spot urine as well as after a two-hour collection period have also been examined. The normal values were determined in 21 healthy volunteers and the reproducibility of the various parameters was analyzed after 1 hour and 25 hours in these volunteers. For diagnosis of an acute episode of chronic pancreatitis serum amylase was found to have good sensitivity, but a specificity inferior to that of serum lipase. By contrast, the specificity of serum lipase is excellent. Unlike determination of serum enzymes, measurement of urinary enzymes in all variations does not offer any further advantage. Except for the combination of serum amylase and serum lipase, none of the other tested combinations provides further diagnostic information. The examination of spot urine samples is not inferior to the 2-hour urine specimen. For the time being the combination of serum amylase and serum lipase determination is again recommended for diagnostic routine in patients with an acute episode of pancreatitis.

Abdomen, Acute↗
PubMedDate not supplied

[Purification and properties of alpha-amylases in morphological variants of Bacillus subtilis].

Extracellular alpha-amylases were isolated from the culture medium filtrates of Bacillus subtilis R-623 morphological variants R, P and S by means of biospecific chromatography on artificial sorbents and then purified to homogeneity. Some properties of purified alpha-amylases were being studied. The molecular weight of alpha-amylases from Bacillus subtilis variants R, P and S equals 57,000, 58,000 and 56,000, and the isoelectric points are at pH 5.4, 5.6 and 5.1, respectively. pH optimum for alpha-amylase from variants R and P is 4.5, and for that from variant S--5.0. alpha-Amylases from Bacillus subtilis R-623 morphological variants are thermostable enzymes. According to the properties studied, they correspond to Bacillus subtilis alpha-amylases that were isolated and described by other researchers.

Bacillus subtilis↗
PubMed1978

Effects of functional nephrectomy on the disappearance rates of canine serum amylase and lipase.

The rates of disappearance of intravenously injected amylase and lipase were determined in dogs before and after ligation of the renal vessels. Functional nephrectomy increased the half life of serum amylase from 5 to 14 hours and of serum lipase from 2 to 11 hours. Serum amylase values increased relatively little in dogs with a functional nephrectomy when enzymes were not infused. The increase in serum amylase activity was not correlated to the increase in serum urea nitrogen. The canine kidney was responsible for the disappearance of part of the amylase and lipase from the serum. Only trace amounts of either amylase or lipase activity were found in the urine. It is assumed the canine kidney inactivated these enzymes.

Amylases↗
PubMed1995

The lipase to amylase ratio in acute pancreatitis.

OBJECTIVES: The ratio of serum lipase to serum amylase has been proposed to distinguish acute episodes of alcoholic from nonalcoholic pancreatitis. We evaluated the efficacy of this test in a community hospital setting. METHODS: Charts of all patients discharged with a diagnosis of acute pancreatitis over 19 months were retrospectively reviewed. Patients were excluded if their creatinine was greater than 3.0 mg/dl, if the amylase and lipase were not measured within 72 h of the onset of symptoms, or if the cause of pancreatitis was not known by the time of discharge. RESULTS: Of the 56 patients, 31 had alcoholic pancreatitis. The lipase to amylase ratio did not differ significantly between patients with alcoholic and nonalcoholic pancreatitis. Median amylase and lipase were significantly higher in nonalcoholic pancreatitis; however, the wide ranges of both meant that neither amylase nor lipase accurately determined the cause of pancreatitis. CONCLUSION: The lipase to amylase ratio does not appear to be sufficiently sensitive or specific to distinguish alcoholic from nonalcoholic acute pancreatitis.

Acute Disease↗
PubMed1994

Charge selectivity and urine amylase isoenzymes.

The urinary excretions of salivary and pancreatic amylase were studied in 718 type I diabetic patients and 51 control subjects, as part of a multicenter study on diabetic nephropathy in 15 Spanish hospitals. It was found that the urinary ratio of salivary to pancreatic amylase (S/P ratio), that in normal subjects is always below 1, was elevated in 35.4% of diabetic patients, whereas microalbuminuria was present in 19.8%. The prevalence of elevated S/P ratio was also higher than that of microalbuminuria at the first years from the onset of the disease, but the prevalence of microalbuminuria was higher in patients with a long duration of the disease. alpha 1-microglobulin and microalbuminuria paralleled their prevalences during the disease, when measured in a group of patients. Overnight urine samples were obtained on three consecutive weeks from the diabetic patients, and a nested ANOVA analysis showed that the intra-individual variation of the urine parameters measured (albumin, salivary and pancreatic amylase, and beta-NAG) was very small and not statistically significant. All these findings suggest that in type I diabetes mellitus, loss of negative charges of GBM would induce preferential excretion of the anionic salivary amylase over the more cationic pancreatic amylase, and that this phenomenon is more frequent and appears earlier than microalbuminuria. The mechanisms for the increased excretion of salivary amylase and albumin into urine seem to be at least partly different. On the contrary, increase in urinary excretion of albumin and alpha 1-microglobulin in these patients are correlated, suggesting a tubular participation in the mechanisms of production of microalbuminuria.

Adolescent↗
PubMed1993

[A case of amylase producing lung cancer].

The patient was a 72-year-old man, who was admitted to our hospital because of cough. Chest X-rays showed a mass shadow in the right lower lung field. Amylase activities in serum and urine were extremely high. Amylase isozyme pattern identified salivary type amylase. Cytological examination of the sputum suggested adenocarcinoma. Amylase activities in serum and urine gradually decreased with the administration of chemotherapy. Afterwards, pleural effusion increased, and the amylase activity in pleural fluid was also extremely high. Pleural fluid also showed adenocarcinoma. Enzyme-labeled antibody method (PAP) on this specimen from pleural fluid proved that tumor cells were producing amylase ectopically.

Adenocarcinoma↗
PubMed1994

[Effect of the changes of amino acids on both signal peptide C-terminal and mature protein N-terminal region to the secretion of alpha-amylase in B. subtilis].

By site-directed mutagenesis, G and C have taken the place of T and G at nucleotide sequence 287 and 291 of B. licheniformis alpha-amylase gene to generate pAm-y413B and the N-terminal sequence of mature protein have been changed from 7Leu 8Met to 7Arg8Ile. By the insertion of polylinker into the C-terminal of the signal sequence of alpha-amylase gene of pAmy413, the signal peptide of alpha-amylase produced by pAmy413L is 13 amino acids more than the pAmy413 (which is 29 amino acids long) and also, a new recognition cleavage sequence for signal peptidase I (Ala-Gln-Ala decreases Ser) is created; The secondary structure of the signal peptide has been analyzed by computer programs. The alpha-amylase relative activity of the two mutant strains is 3% and 36% of pAmy413, respectively. The molecular weight of extracellular alpha-amylase is the same as pAmy413. Terminal analysis shows that the N-terminal amino acid of mature protein is Ala, not Ser, and suggests that SPase I prefers to cleavage at the wild type recognition site (Ala-Ala-Ala decreases Ala). Therefore, all of the above results show that the secretion of alpha-amylase in B. subtilis is in accordance with the co-translational transportation model.

Amino Acid Sequence↗