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Biomedical subjects

P Sharon

Publications and source records attributed to P Sharon.

35 records · Page 2Linked to original sources
PubMed1981

PGE2 mediates the effect of pentagastrin on intestinal adenylate cyclase and Na-K-ATPase activities.

The hypothesis that PGE2 mediates the effect of pentagastrin on jejunal Na-K-ATPase and adenylate cyclase activities was tested in rats. Mucosal PGE2 and cAMP contents, Na-K-ATPase and adenylate cyclase activities were determined 45 min after IV pentagastrin (1 microgram/100 g b.w.) administration to pyloric ligated rats. Pentagastrin almost doubled mucosal PGE2 content as compared to that in saline-treated rats: 198 +/- 19 (S.E., N = 11) and 109 +/- 9 (S.E., N = 26) pg/mg tissue, respectively, inhibited mucosal Na-K-ATPase activity: 16.4 +/- 0.7 (S.E., N = 8) as compared to 26.7 +/- 4.0 (S.E., N = 13) mumole/mg protein/h in saline-treated rats, stimulated adenylate cyclase activity by 146% and increased mucosal cAMP content by 80%. Pretreatment with indomethacin (4 mg/kg b.w., s.c./day x 2) prevented the increase in PGE2 content, the stimulation of adenylate cyclase activity and the inhibition of jejunal Na-K-ATPase activity induced by pentagastrin. The results reported thus suggest that the mechanisms whereby pentagastrin affects intestinal water and electrolyte transport are probably mediated by mucosal PGE2 and include inhibition of Na-K-ATPase activity and stimulation of the adenylate cyclase - cAMP system.

Adenylyl Cyclases↗
PubMed1981

Enhanced thromboxane A2 and prostacyclin production by cultured rectal mucosa in ulcerative colitis and its inhibition by steroids and sulfasalazine.

Accumulation of 6-ketoprostaglandin F1 alpha and thromboxane B2, the stable metabolites of prostacyclin I2 and thromboxane A2 respectively, by cultured rectal mucosa obtained from patients with active ulcerative colitis was significantly higher than their respective accumulation by cultured biopsy specimens obtained from normal subjects. Accumulation of prostacyclin I2 and thromboxane A2 by rectal mucosa obtained from ulcerative colitis patients in remission was not enhanced. Prostacyclin I2, thromboxane A2, and prostaglandin E2 accumulation was significantly inhibited by the addition to the culture medium of 5-aminosalicylic acid, flufenamic acid, aspirin, azathioprine, and methylprednisolone. Sulfapyridine inhibited significantly only prostaglandin E2 and prostacyclin I2 while sulfasalazine inhibited thromboxane A2, prostaglandin E2, and prostacyclin I2 accumulation. Flufenamic acid potentiated the inhibition of prostaglandin E2 accumulation induced by methylprednisolone when administered alone. These results suggest that in addition to the mediation by prostaglandin E2, thromboxane A2 and prostacylin I2 may also be involved in the inflammatory response in ulcerative colitis. Moreover, the therapeutic effects of steroid hormones and sulfasalazine may be partially related to their inhibition of colonic prostaglandin E2, prostacyclin I2, and thromboxane A2 synthesis.

Colitis, Ulcerative↗
PubMed1980

Lipoprotein synthesis and secretion by cultured human intestinal mucosa.

We tested whether cultured human jejunal mucosa incorporates fatty acid into esterified lipids and whether organ culture can serve as a model system to study lipoprotein secretion by the human gut. Jejunal biopsies obtained from seven subjects were cultured for 24 h in medium containing 2 microCi of [3H]palmitic acid. More than 95% of the radioactivity incorporated by the tissue was found to be associated with esterified lipids: triglycerides, cholesterol esters and phospholipids, 7 . 8 +/- 1 . 2, 0 . 5 +/- 0 . 1 and 14 . 0 +/- 1 . 5 nmol/10 mg weight respectively. During the culture labelled triglycerides, phospholipids and cholesterol esters were secreted to the medium. Most of the newly synthesized esterified lipids in the medium were found in the d < 1 . 019 g/ml and d = 1 . 019--1 . 063 g/ml fractions. The majority of the newly synthesized triglycerides were found in the d < 1 . 019 g/ml fraction. Labelled cholesterol esters were enriched in the d = 1 . 063--1 . 21 g/ml fraction. Boiled biopsies adsorbed negligible amounts of radioactive palmitic acid and did not synthesize esterified lipids. The addition of puromycin to the culture medium and preincubation with colchicine resulted in decreased uptake of the labelled fatty acid and decreased secretion of esterified lipids to the medium. These experiments indicate that cultured human intestinal mucosa is a suitable model to study lipid synthesis and lipoprotein secretion by the human intestine.

Adolescent↗
PubMed1980

Glycogenic acanthosis of the esophagus. A benign but confusing endoscopic lesion.

During 160 consecutive fiberoptic endoscopic examinations, glycogenic acanthosis was diagnosed in 24 patients. The endoscopic diagnosis was confirmed histologically in the first 14 patients from whom biopsies were obtained. No correlation with any other disease affecting the gastrointestinal tract was found including reflux esophagitis. This common benign condition must be differentiated from lesions of similar appearance and more important prognostic significance.

Biopsy↗
PubMed1978

Role of prostaglandins in ulcerative colitis. Enhanced production during active disease and inhibition by sulfasalazine.

Prostaglandin E2 (PGE2) level in rectal mucosa excised from 17 patients suffering from ulcerative colitis was 2-fold higher than that found in rectal mucosa of 17 normal subjects: 2.0 +/- 0.4 and 0.9 +/- 0.2 ng per mg of wet tissue, respectively. Accumulation of PGE 2 in 24-hr cultures of rectal mucosa specimens obtained from patients with ulcerative colitis was 112% higher than that observed in cultures from control subjects. Addition of sulfasalazine, sulfapyridine, and 5-aminosalicylic, acid to the culture medium of ulcerative colitis mucosa resulted in inhibition of PGE2 production by 34, 32, and 62%, respectively, compared to rectal specimens cultured in drug-free medium. These results suggest that PGE may mediate the inflammatory response in ulcerative colitis and that some of the therapeutic effect of sulfasalazine and its constituents are related to the inhibition of PGE synthesis.

Aminosalicylic Acids↗
PubMed1978

Giant cell carcinoma of the pancreas. Report of a case with upper gastrointestinal bleeding diagnosed by endoscopic brush cytology.

A case of upper gastrointestinal bleeding as the first and only manifestation of giant cell carcinoma of the pancreas invading the duodenum is described. The polypoid tumor was visualized during endoscopy. The diagnosis was made by a cytologic brush and confirmed by endoscopic biopsy. The rather uncommon presentation of pancreatic carcinoma and the possibility of establishing the diagnosis by a cytologic brush is discussed.

Aged↗
PubMed1977

Aseptic necrosis of head of femur: presenting manifestation in Cushing's disease.

Aseptic necrosis of bone is a known complication of corticosteroid therapy. We report a case of aseptic necrosis of the femoral head as a presenting symptom of Cushing's disease. The case demonstrates that endogenous steroids, like exogenous steroids, may bear the same relationship to the pathogenesis of aseptic necrosis of bone. It also indicates that Cushing's disease must be considered in every case of so-called idiopathic aseptic necrosis of bone.

17-Hydroxycorticosteroids↗
PubMedDate not supplied

Prostaglandins in disorders of the intestinal tract: a review.

Prostaglandins (PGs) are natural oxygenated products of polyunsaturated fatty acids. They have multiple effects on the gastrointestinal tract. Their major physiological roles in the intestine are the promotion of solute and water secretion and the control of bowel motility. Prostaglandins have a role in the pathogenesis of diarrhea in a wide spectrum of gastrointestinal disorders. The effects and the potential contribution of PGs in various gastrointestinal disorders are discussed, and therapeutic modalities in these disorders are reviewed.

Humans↗
PubMedDate not supplied

Acute pancreatitis in a community with a low alcohol intake.

The etiological factors in 130 cases of acute pancreatitis occurring in a community with a low alcohol intake were reviewed. Alcohol was an insignificant factor in the etiology of acute pancreatitis. So-called idiopathic pancreatitis, occurring mainly in the older age group, was diagnosed in 19% of the cases. This is in contradistinction to findings in populations with excessive alcohol intake, where idiopathic pancreatitis is seen in all age groups. Similar age and sex distribution, as well as biochemical evidence of cholestasis, were seen in both the group suffering from gallbladder disease and in the idiopathic group. A more aggressive diagnostic work-up, including surgical exploration, is warranted, in view of the clinical overlap of biliary tract disease and idiopathic pancreatitis.

Acute Disease↗