Search PubMed⌕ Search

Biomedical subjects

D W Piper

Publications and source records attributed to D W Piper.

At least 109 records · Page 6Linked to original sources
PubMed1977

beta-Glucoronidase and the gastric epithelial cell. A study using organ culture.

In an attempt to determine the significance of increased beta-glucuronidase content of gastric juice of patients with gastric carcinoma, gastric mucosal cells were exposed, in organ culture technique, to a known gastric carcinogen and indices of carcinogenic activity were studied in the ambient fluid and in the mucosal cells. Isotopic methods were used to determine cell viability. Indices of carcinogenic activity in the ambient fluid were beta-glucuronidase and lactate production and changes in the LDH isoenzyme pattern of the homogenates of the exposed cells were also studied. Incubation with the carcinogen resulted in increased production of beta-glucuronidase and lactate, suggesting the increased beta-glucuronidase activity in the gastric juice of patients with gastric cancer indicates malignancy.

Carcinogens↗
PubMed1977

Aspirin esterase of gastric mucosal origin.

The enzyme, aspirin esterase, which converts acetylsalicyclic acid to the less toxic salicyclic acid, was found to be present in gastric mucosal specimens obtained from surgically resected tissue. The enzyme was found to be stable to storage and active at two pH optima. Alcohol in the reaction mixture produced a net effect of slowing the rate of aspirin hydrolysis; this was attributable to a marked inhibitory effect on aspirin esterase activity which was not completely counteracted by the increased rate of spontaneous breakdown of aspirin by alcohol. Age, sex, or gastric disease state of the patient from whom the tissue was obtained, did not significantly alter the level of enzyme activity measured, nor were different levels obtained from body or antral mucosa. In patients with gastric ulcer, those with a previous history of regular aspirin consumption did not show significantly different levels from those without such a history. It is concluded that aspirin esterase activity of gastric mucosa is not alone a significant factor in any role acetylsalicyclic acid may play in the etiology and natural history of chronic peptic ulcer.

Age Factors↗
PubMed1977

Personality pattern of patients with chronic gastric ulcer. Study of neuroticism and extroversion in a gastric ulcer and a control population.

Forty-four patients with chronic gastric ulcer were compared with a control group matched for age, sex, and place of residence. The personality pattern was studied by the Eysenck Personality Inventory and personality assessed in terms of neuroticism and extroversion. The relevance of social class was also studied. The gastric ulcer population did not differ from the control group except among the male population, in which the gastric ulcer population was significantly more neurotic and less extroverted than their controls.

Adult↗
PubMed1977

Krebs cycle, pentose phosphate pathway, and glycolysis in the uninvolved gastric mucosa of peptic ulcer and gastric cancer patients.

Uninvolved gastric mucosa from duodenal ulcer, gastric ulcer, and gastric cancer patients was incubated with [1-14C]glucose and [6-14C]glucose in order to assess the relative contributions of the pentose phosphate pathway and Krebs cycle to glucose metabolism. [14C]Glucose counts retained by the tissue, glycolysis, and pyruvate formation were also measured. Tumor tissue from the cancer patients was included in the study. Less than 1.2% of the glucose entering the tissues was metabolized via the pentose phosphate pathway; suggesting that this pathway plays a minor role in energy production from glucose. The major determinant of energy production was the Krebs cycle. Its contribution to glucose metabolism was greatest in the body mucosa of duodenal ulcer patients, less in the uninvolved body mucosa of gastric ulcer patients, and lower still in the corresponding body mucosa of gastric cancer patients. The low levels of Krebs cycle activity seen in the latter tissue resembled those of uninvolved antral mucosa. The smallest Krebs cycle contribution was seen in tumor tissue. [14C]Glucose counts retained by the tissue and glycolysis both tended to vary inversely with Krebs cycle activity among the tissues studied. Thus, both were small in the body mucosa of noncancer patients and somewhat larger in the body mucosa of cancer patients, in uninvolved antral mucosa and in tumor tissue.

Aerobiosis↗
PubMed1976

Acute upper gastrointestinal haemorrhage with negative barium-meal x-ray findings: follow-up investigation.

One-hundred and one patients admitted to hospital with acute upper gastrointestinal haemorrhage whose initial barium-meal X-ray examination revealed no abnormality have been followed up 5 to 14 years later. Forty-five were symptom-free, and 8 had dyspepsia, but the barium-meal X-ray findings were still normal. Disease of the lower oesophagus, the stomach or the duodenum was found in 20, 16 of whom had a chronic peptic ulcer and two had gastric carcinoma. There was a poor prognosis for those gastric-ulcer patients whose diagnosis had been missed initially.

Acute Disease↗
PubMed1976

LDH isoenzyme pattern of uninvolved gastric mucosa of patients with gastric carcinoma and benign gastric disease.

The LDH isoenzyme pattern of the uninvolved mucosa of gastric cancer patients differs as regards the LDH isoenzyme pattern from that of similar tissue of patients with benign gastric disease; the former tissue is characterised by a high M/H ratio of the LDH isoenzymes (M and H sub-units). A high M/H ratio characterises antral mucosa when the latter is compared with fundic mucosa. Mucosa showing superficial and atrophic gastritis also has a higher M/H ratio, whereas the presence of intestinal metaplasia does not appear to influence the M/H ratio. These observations are consistent with the concept that the tissue from which the cancer arose may possess a pre-malignant biochemical lesion.

Duodenal Ulcer↗
PubMed1976

Demethylchlortetracycline-binding proteins in uninvolved gastric mucosa of gastric carcinoma and gastric ulcer patients. Demonstration of a difference between the uninvolved mucosa of ulcer and cancer patients.

The uninvolved gastric mucosa of gastric ulcer and gastric carcinoma patients has been compared in in vitro studies as regards their capacity to bind demethylchlortetracycline (DMCT). Dialysis experiments demonstrated excessive binding of DMCT in gastric cancer. Several electrophoretic fractions were observed that bound DMCT; it was demonstrated that these fractions differed in the uninvolved mucosa of gastric ulcer and gastric cancer patients.

Adenocarcinoma↗
PubMed1976

Effect of sodium amylosulfate (Depepsen) on the healing of duodenal ulcer.

Thirty-five patients with active duodenal ulceration were included in a double blind randomized trial, the antiulcer agent sodium amylosulfate (Depepsen), being compared with placebo. Diagnosis and healing were determined by duodenoscopy. Results showed, in the whole series, 13 of 18 patients treated with Depepsen healed, whereas 10 of 17 healed on placebo (P = 0.04). In the group of 23 outpatients, 6 of 11 healed on Depepsen, and 5 of 12 healed on placebo (P = 0.55). It was concluded that Depepsen did not accelerate the healing of duodenal ulcer.

Adult↗
PubMed1975

The assay of pyruvate kinase activity in gastric mucosa.

Pyruvate kinase activity in gastric mucosal supernatant preparations shows large responses to exogenous effectors. At pH 7.5, fructose 1,6-diphosphate can cause large stimulations in activity. Alanine inhibits the reaction but this effect is partially reversed by fructose 1,6-diphosphate. In the absence of these compounds, 4.0-5.0 mM phosphoenolpyruvate (PEP) is required to generate maximal activity in the assay system used. Electrophoresis reveals an isoenzyme pattern containing only one form of pyruvate kinase, an M isoenzyme, in both fundic and antral mucosa. The pyruvate kinase of gastric mucosa thus resembles the M-type enzymes of leucocytes and liver. Measurements of activity at both 1.0 mM PEP and 4.0--5.0 mM PEP, with and without additions of fructose 1,6-diphosphate, are recommended for the reliable estimation of pyruvate kinase activity in this tissue.

Animals↗
PubMed1975

Factors relevant to the prognosis of chronic gastric ulcer.

The factors that determine the recurrence rate of chronic gastric ulcer were studied in 105 patients. It was found that complete healing of the ulcer significantly reduced the recurrence rate and subsequent need for hospital admission because of ulcer symptoms when this group was compared with those who left hospital with their ulcers unhealed. Those admitted with large ulcers also had a higher recurrence rate. The age and sex of the patient, ingestion of analgesics and cigarette smoking did not influence recurrence. The initial healing rate of the ulcer also had no effect on the subsequent course of the patient.

Age Factors↗
PubMed1975

The stability of human pepsins in stored gastric juice.

The effect of storage at -20 degrees C and +2 degrees C on the pepsins of human gastric juice was assessed by quantitative assay and agar gel electrophoresis. Quantitative assays showed no significant loss of peptic activity at either temperature over periods of storage up to 3 weeks, and no correlation between change in peptic activity and the acidity of the gastric juice, although raising the pH of the gastric juice above pH 2 with buffers gave improved stability over gastric juice mixed with buffer of lower pH. At low pH, the addition of bovine serum albumin gave improved stability. Agar gel electrophoresis showed that the pepsins were all stable at -20 degrees C for several days or several weeks, but alterations occurred in the pepsin molecules after several months.

Buffers↗