An in vitro digestion method to assess the quality of proteins based on enzymatic hydrolysis is presented. The method consists of a two-step proteolysis at 37 degrees, a 30-minute incubation of the protein with pepsin at pH 1.9, followed by pancreatin digestion at pH 8 for 24 hours in a dialysis bag with a 1000 molecular weight cutoff for the continuous elimination of the digested products into a replaceable buffer. Three types of buffer replacement were tried. These were, in increasing order of efficiency: intermittent with either six changes (infrequent buffer replacement) or eleven changes (frequent buffer replacement) or continuously circulated at the rate of 212 ml/hour (continuous buffer replacement). By using three protein sources, i.e., casein, soybean and rapeseed proteins, it was found that the degree of digestion (dialyzed N) as well as the regularity of the process were markedly improved by increasing the frequency of buffer replacement. In spite of different pepsin digestibilities, as determined from the production of trichloroacetic acid-soluble N, the digestion of the three proteins gave equivalent results when the best procedure of buffer replacement was used (continuous buffer replacement). The deleterious effect of heat and alkali treatment on protein digestion was readily shown by this procedure and indicated casein to be a very heat-sensitive protein as compared to the others.

Brassica↗

PubMed1982

Double-blind controlled trial of bethanechol and antacid versus placebo and antacid in the treatment of erosive esophagitis.

To determine the value of bethanechol in the treatment of erosive esophagitis, a double-blind study was undertaken in which 28 patients were randomized to either bethanechol and antacid, or placebo and antacid. Patients were evaluated clinically, endoscopically, and by esophageal manometry before and after 8 wk of therapy. After treatment both groups showed significant improvement in heartburn and in healing of esophageal lesions. Patients who received bethanechol plus antacids did not show a greater improvement than patients who received placebo plus antacids in any category, nor did patients in the bethanechol-treated group have a greater incidence of complete healing. In addition, pretreatment mean lower esophageal sphincter pressure was normal in approximately 30% of patients with erosive esophagitis and this finding was associated with a greater chance for complete healing of esophageal lesions. These results fail to show that the addition of bethanechol to an intensive antacid regimen is more effective than the antacid regimen alone in the treatment of erosive esophagitis and that patients with esophagitis and normal lower esophageal sphincter pressures respond more favorably to medical treatment.

Antacids↗

PubMed1982

Esophageal potential difference measurements in esophageal disease.

To determine if esophageal transmural electrical potential difference measurements are of use for evaluating esophageal disease, we recorded potential difference in 129 patients with one or more of the following: heartburn, dysphagia, and chest pain. All potential difference studies were performed at the time of esophageal manometry using a Ringer-perfused catheter technique which yields accurate and reproducible results in healthy subjects. In 103 of the 129 patients, esophageal potential difference measurements could be correlated with findings at manometry, endoscopy, and biopsy. The remaining 26 patients had primary esophageal motor disease and were not biopsied. The results of this investigation showed: (a) that 94% of patients with gross endoscopic lesions have an abnormal esophageal potential difference, (b) that an abnormal esophageal potential difference (found in only 1 of 24 patients with normal mucosa) is highly specific for the presence of esophageal mucosal disease, (c) that the type of potential difference abnormality may suggest the nature of the mucosal abnormality, for example high potential difference with Barrett's esophagus and low potential difference with esophagitis or invasive carcinoma, and (d) that while an abnormal esophageal potential difference is highly sensitive for detecting gross esophagitis (38 of 40 patients), it is less sensitive for diagnosing microscopic esophagitis (8 of 16 patients). Based on these findings we conclude that the measurement of esophageal potential difference at the time of manometry can provide additional valuable information about the state of the esophageal mucosa.

Action Potentials↗

PubMed1981

A comparison of GE(Li) detectors with different efficiencies for low-level general purpose counting.

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Germanium↗

PubMed1981

A current approach to rectal bleeding.

The source of bleeding from the rectum is extremely difficult to specify in many patients with moderate to severe bleeding. Lesions may be located anywhere along the gastrointestinal tract. On the basis of the available literature and reported clinical data, we conclude that moderate to severe rectal bleeding originates from the upper gut in up to 10% of patients, from the small bowel in up to 5%, and from the colon in the remaining 85%. Diverticulosis and vascular dysplasia account for 30-50% of colonic bleeding, and inflammatory bowel disease and ischemic colitis for another 5-15%. No diagnosis is made in 20-30% of patients with moderate to severe rectal bleeding. Patients with rectal bleeding can be classified as those whose bleeding stops spontaneously, those whose bleeding stops and then recurs, and those whose bleeding continues despite conventional treatment. Based on these classifications, we present an approach to the diagnosis and therapy of rectal bleeding.

Colonic Diseases↗

PubMed1981

A current approach to acute upper gastrointestinal bleeding.

The mortality in patients with upper gastrointestinal bleeding has not changed in the past quarter century in spite of the introduction of new modes of therapy and treatment. In this review we address the possible reasons for a lack of change in mortality and the implications raised for the use of new techniques. We review the factors that affect the mortality of acute upper gastrointestinal hemorrhage and the diagnostic accuracy of upper gastrointestinal endoscopy. Based on this information, we present guidelines for the therapy of the major causes of upper gastrointestinal bleeding. These guidelines should be useful until new therapies have been assessed and become generally available.

Age Factors↗

PubMed1981

Effect of gibberellic Acid on silica content and distribution in sugarcane.

The effect of gibberellic acid on the content and distribution of silicon in the stem, leaf sheath, and leaf lamina of sugarcane was analyzed in relation to the effect of gibberellic acid on stem growth. Silicon content was measured by neutron activation analysis, and its distribution was followed by scanning electron microscopy and X-ray analysis.Foliarly applied gibberellic acid increased stem length and fresh weight and decreased silicon content. Gibberellic acid treatments had little or no effect on growth or silicon content of leaf laminae or sheaths. The close correlation between increase in growth of an internode in response to gibberellic acid and the decrease in silicon content of that internode indicated a dilution effect of growth on the amount of silicon rather than a direct effect of gibberellic acid on silicon deposition. This conclusion was supported by scanning electrom microscopy, X-ray map photos, and counts of silica cells per unit of epidermis area.

Journal Article↗

PubMed1981

Plasma alpha-amino-n-butyric acid/leucine ratio in alcoholics.

Fasting free amino acid concentrations in plasma of 20 control and 18 alcoholic subjects were compared in an attempt to validate previous reports that the molar ratio of alpha-amino-n-butyric acid/leucine (A/L ratio) is a marker for alcoholism. We were unable to confirm the observations of either altered alpha-amino-n-butyric acid or leucine concentrations or an increased A/L ratio in alcoholic subjects, and we conclude that the A/L ratio is not a biochemical marker for alcoholism.

Adult↗

PubMed1981

Renal toxicity during therapy with gentamicin or tobramycin.

Twenty-seven patients who had normal pretherapy renal clearance by the [125I]iothalamate test were randomly assigned either gentamicin or tobramycin for therapy of infections due to susceptible bacteria. No patients were critically ill or had evidence of bacteremia. Mean age and duration of therapy were 51 years and 14 days, respectively, for 15 patients treated with gentamicin, and 45 years and 13 days for 12 patients treated with tobramycin. At the completion of therapy, six (40%) gentamicin and seven (58%) tobramycin patients had a decrease in renal clearance of at least 14% below baseline. The mean decrease was 26% in the gentamicin group and 23% in the tobramycin group. Simultaneous increases in serum creatinine concentrations (greater than or equal to 0.2 mg/dl) occurred in only 4 (31%) of the 13 patients. Of four patients who had renal clearance studies repeated 3 weeks to 6 months after therapy, two had stable function, but at 16 to 19% below baseline. Mean urinary concentration of N-acetyl glucosaminidase and alanine aminopeptidase increased faster and to higher levels with gentamicin than with tobramycin. However, on an individual patient basis, they were not predictive of a decrease in renal clearance in either therapy group.

Acetylglucosaminidase↗

PubMed1981

Colorimetric vs liquid-chromatographic determination of urinary 5-hydroxyindole-3-acetic acid.

The popular colorimetric assay for urinary 5-hydroxyindole-3-acetic acid based on the reaction with 1-nitroso-2-naphthol has been criticized for lack of specificity. Goldenberg (Clin. Chem. 19: 38-44, 1973) proposed a modification of this method, in which 2-mercaptoethanol is used to discharge unwanted chromophores. We compared results by both the unmodified and modified colorimetric methods with those by a "high-performance" liquid-chromatographic method, with fluorometric detection. Agreement among all three assays was excellent in the range of 50 to 600 mg/24 h, but there were considerable differences in the range 0 to 30 mg/24 h between results by the unmodified colorimetric assay and the other two. In this range, results by the modified assay (y) correlated well with those by the chromatographic method (x), although the values were slightly lower (y = 0.85x + 0.11, r = 0.9303). Using the modified colorimetric assay to analyze 40 normal specimens, we defined a normal range of 0 to 6 mg/24 h). We recommend the modified colorimetric assay for use in the high-volume laboratory and either this assay or the liquid-chromatographic method for the smaller laboratory.

Chromatography, High Pressure Liquid↗

PubMed1981

The nature and prognostic significance of serial amino acid determinations in severe chronic active liver disease.

Serum amino acid levels were determined in 29 patients with severe chronic active liver disease before, during, and after administration of prednisone or placebo and in 22 healthy controls. The pretreatment molar ratio of amino acids was less in patients than in controls (p less than 0.001) and was lower in those with cirrhosis (p less than 0.02). Branched-chain amino acid levels were elevated in patients without cirrhosis (p less than 0.02) but not in those with cirrhosis; aromatic amino acid concentrations were increased in all (p less than 0.01). The ratio improved with remission and predicted behavior after discontinuation of treatment. Patients who deteriorated failed to improve the ratio and those whose ratio improved incompletely relapsed. The ratio correlated with histologic severity and serum concentrations of albumin, bilirubin, and gamma-globulin and not with clinical manifestations of encephalopathy. We conclude that amino acid abnormalities reflect liver dysfunction and that normalization of the molar ratio may have therapeutic and prognostic significance.

Adolescent↗

PubMed1981

The maintenance of pets in allergic families. I. A survey of health beliefs.

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Animals↗

PubMed1980

Determination of serum inorganic phosphorus using a discrete analyzer.

Concentrations of polyvinylpyrrolidone and o-phenylenediamine have been optimized to allow performance of serum inorganic phosphorus using a discrete analyzer, the Vickers M-300. The reagents are stable. The method is precise, accurate, reliable and very sensitive. A precipitate forms in the reaction mixture from some serum specimens containing abnormal globulins.

Autoanalysis↗

PubMed1980

Glutamine therapy of cystinuria.

We studied the urinary excretion of cystine, acids, and cystine crystalluria in five patients with homozygous cystinuraia before and during oral glutamine therapy. Oral glutamine did not change the absolute urinary excretion or fractional excretion of cystine in our patients and did not significantly affect urinary pH. Cystine crystalluria was present before and during oral glutamine therapy.

Administration, Oral↗