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Biomedical subjects

L Sheehan

Publications and source records attributed to L Sheehan.

7 recordsLinked to original sources
PubMed1993

Spontaneous bile reflux in the elderly.

Duodenogastric bile reflux is common in postoperative stomach but has been reported in intact stomachs. Spontaneous bile reflux in the elderly has not been studied before. This has been assessed in dyspeptic elderly and young patients. Total bile acid (TBA) levels and pH were measured in the samples of fasting gastric juice. Antral biopsies were taken for histological examination including Helicobacter pylori identification. TBA levels were significantly higher in elderly patients with gastritis in comparison to elderly and young normal groups. Only 10% of elderly patients with gastritis and 7% with gastric ulcer has abnormal TBA (> 1 mmol/l). There was some correlation between the pH and TBA but a significant proportion of elderly patients has pH > 4 with a normal TBA. TBA levels were not significantly different in H. pylori +ve and H. pylori -ve patients. Nineteen elderly patients had evidence of reactive gastritis. Five of these patients had raised TBA levels with severe H. pylori infection. The remaining 15 patients had normal TBA. These patients were on NSAIDs and 4 of them had H. pylori infection. We conclude that spontaneous bile reflux in the elderly is uncommon. Hypochlorhydria which is observed in the elderly is not caused by alkaline bile reflux. The main cause of reactive gastritis in the elderly is NSAIDs ingestion.

Adult↗
PubMed1983

Conversion of substance P to C-terminal fragments in human plasma.

Substance P is rapidly converted by enzyme(s) in human plasma to des-[Arg1Pro2]-substance P (fragment 3-11) and to des-[Arg1Pro2Lys3Pro4]-substance P (fragment 5-11). These metabolites were isolated by HPLC and partially sequenced. No evidence was obtained for deamidation of substance P in plasma or for the formation of the N-terminal tetrapeptide [Arg-Pro-Lys-Pro]. The data suggest that substance P is metabolized in human plasma by an enzyme with the specificity of dipeptidyl-aminopeptidase IV. Consistent with this hypothesis, the rate of degradation of substance P measured with an antibody directed against the N-terminal region is 2-3-fold greater than measured with a C-terminally directed antibody. The degrading activity of plasma was purified 522-fold and was eluted from a gel filtration column in the molecular weight zone 150 000-170 000 and from a chromatofocusing column in the pH range 4.5 to 5.5.

Amino Acid Sequence↗
PubMed1978

Evaluation of non-core laboratories.

The CAP Interlaboratory Survey data from the non-core laboratories identified by Paule and Mandel were examined. Some laboratories were designated non-core because they submitted one or more values that were widely discrepant and were caused by unit problems, decimal shifts, or reversal of the specimens. A second group of laboratories submitted a number of discrepant results that appeared to be caused by problems within the laboratories. A third group submitted results that appeared acceptable, and the exclusion and the effectiveness of the criteria differed for each of the three analytes. The findings suggest that examination of data from excluded laboratories can provide a valuable source of information to supplement the central data.

Blood Chemical Analysis↗
PubMed1976

Urinary polyamine levels in patients with localized malignancy.

Polyamine levels (putrescine, spermidine, and spermine) were determined in 24-hour urine samples by a high voltage electroporesis techique. Twenty-four of 26 patients with localized malignant tumors had two or more elevated urinary polyamine levels. Seven of 12 patients with regional spread of their cancer and five of 11 patients with localized benign and/or noninvasive tumors had elevated urinary polyamine levels. Elevations were seen more frequently frequently in patients with gynecologic tumors. Our data suggest that there is no significant difference between the individual of total polyamine levels obtained in patients with localized malignant tumors, and those levels obtained in patients previously studied with widespread metastatic disease.

Adolescent↗
PubMed1975

Urinary polyamine levels in patients with gastrointestinal malignancy.

Polyamine levels (putrescine, spermidine, and spermine) were determined in 24-hour urine samples by a high voltage electrophoresis technique. Eleven of 14 patients with widespread metastatic gastrointestinal cancer had two or more elevated polyamine values. Two patients with cancer confined to the colon and two with cancer spread within the pelvis had two or more elevated polyamine values. Three patients who had all known disease removed by surgery, two patients with gastric lymphoma, and one patient with a vilous adenoma of the colon had normal values. Individual values of spermidine and spermine appeared to be elevated more frequently than putrescine values in these patients.

Adolescent↗
PubMed1975

Preliminary evaluation of urinary polyamines in the diagnosis of genitourinary tract malignancy.

Normal ranges for urinary polyamines have been obtained. Non-malignant genitourinary tract disease is not associated with elevated urinary polyamines. A high correlation exists between the presence of active urologic cancer and elevated urinary excretion of polyamines. Post-treatment polyamines correlate with the continued presence or absence of genitourinary tract malignancy.

Adenocarcinoma↗