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Biomedical subjects

F G Moody

Publications and source records attributed to F G Moody.

At least 109 records · Page 6Linked to original sources
PubMed1980

A mechanism for prostaglandin cytoprotection.

Topical 16,16-dimethyl (dm) prostaglandin E2 produces an alkaline secretion from the canine stomach. This study attempts to assess whether this prostaglandin-induced secretion might have a cytoprotective role. Chambered ex vivo perfused wedges of canine stomach were divided into equal halves: a control and test side. The mucosa of each half was sequentially exposed to isosmotic hydrochloric acid, 20 microgram of 16,16 dm PGE2 in acid, 20 mmol aspirin + 20 microgram of dm PGE2 in acid then isosmotic acid. The test side received 40 mmHg pneumatic counterpressure to reduce the prostaglandin-induced fluid movement before, during and after the aspirin exposure. The mucosal lesions produced on each side were graded 0 to 14. If prostaglandin exerts its cytoprotective effect by stimulating an alkaline secretion, elimination of that secretion with counterpressure should prevent a cytoprotective action. Nine dogs were studied. Topical prostaglandin increased transmucosal fluid movement from 10 microliter/min to 65 microliter/min. Counterpressure decreased this volume flow by 50 per cent (P < 0.01); it also decreased mucosal blood flow on the test side by 20 per cent (P < 0.05). The lesions on the counterpressure side were worse 2.0 +/- 0.6 v. 0.8 +/- 0.3 (P < 0.01). Thus the greater damage in the counterpressure group could have been caused by diminished fluid movement or by reduced blood flow or a combination of both factors. Although this study cannot distinguish between these possibilities, it seems like that the prostaglandin-induced alkaline secretion has a cytoprotective role.

16,16-Dimethylprostaglandin E2↗
PubMed1979

Sepsis in the management of complicated biliary disorders.

Postoperative sepsis developed in 72 per cent of 25 patients with noncalculous proximal biliary tract obstruction. Six episodes of shock and one death resulted. Twenty-eight per cent of septic events occurred despite the administration of prophylactic antibiotics. The incidence of septic complications was similar regardless of the biliary drainage procedure used. Despite the advent of broad spectrum antibiotics and improved surgical techniques for biliary decompression, sepsis remains a serious and frequent complication in patients with chronic bile duct obstruction.

Adolescent↗
PubMed1979

A model of biliary pancreatic reflux.

A primate model for the study of biliary pancreatic reflux under relatively physiological conditions is described. Cannulas were inserted into the gallbladder and the common bile duct of rhesus monkeys, and a pedicled segment of small bowel was used to create a pancreaticocutaneous fistula after resection of the spleen and pancreatic tail. Following recovery, Hypaque was instilled into the gallbladder with maintenance of common duct pressure within a normal range. The pancreatic duct was visualized in 21 of 34 radiographic studies (19 monkeys). Small amounts of iodine were detected in the fistula effluent of nine of 11 animals that refluxed radiologically. Radioactive polyethylene glycol (PEG-C14) was instilled into the gallbladder and pancreatic fistula drainage sampled by aspiration (26 studies, four monkeys). When compared to controls without PEG instillation (six studies, four monkeys), there was a significant rise in fistula counts beginning 50 minutes after injection and peaking at 180 minutes. In a second series of studies, pancreatic fistula aspiration was replaced by a flush technique using a triple-lumen cannula which allowed constant monitoring and control of fistula pressure. A statistically significant rise and fall of radioactivity after PEG introduction again was demonstrated. These data demonstrate taht biliary pancreatic reflux can occur and be quantitated under these experimental conditions.

Animals↗
PubMed1979

Mechanisms of mucus release in exposed canine gastric mucosa.

Mucus release was studied in the exposed gastric mucosa of anesthetized fasted dogs using scanning and transmission microscopy as well as histochemical and autoradiographic techniques. Under unstimulated conditions, the gastric epithelium was composed of both nonsecreting and mucus-secreting epithelial cells, with the former being predominant. Nonsecreting cells were characterized by an intact apical mucus package of granules and a continuous plasma membrane. The secreting mucus cell population was found in the foveolar (pit region) as well as interfoveolar areas. Three mechanisms of mucus release were observed: (a) exocytosis, (b) apical expulsion, and (c) cell exfoliation. Evidence for exocytosis was found in all mucus cells, especially in the sulfated glycoprotein-rich foveolar cells. Exocytosis involved only a few granules at a time; this mode of secretion is likely slow and continuous. In contrast, apical expulsion resulted in an explosive release of the entire apical mucus package followed by in situ degeneration of the cell itself. This occurred in the oldest cells forming mucosal crests in the interfoveolar area, whose mucus predominantly stains for neutral glycoproteins. Cell exfoliation, in which the entire cell was extruded into the lumen, was rarely observed and may provide, in addition to apical expulsion, a second mechanism to rid the mucosa of senescent epithelial cells. Mucus secretion is a complex function of the gastric epithelium. The mechanism of secretion and the histochemically defined type of mucus secreted are variables which are dependent on the age of the cell, its position on the foveolae, and the microenvironment within the gastric lumen. The mucus-containing surface and pit cells of gastric epithelium have been described morphologically and ultrastructurally in a number of studies. These cells are highly differentiated, forming a layer which is dynamic and responsive to conditions present in the gastric lumen. Mucus cells arise from multipotent progenitor cells which differentiate in the course of migration up the gastric pits and are involved in the complex macromolecular synthesis of glycoproteins. Although mucus release occurs throughout cell life, very little attention has been given to the cellular ultrastructural changes that deal with mucus secretion. As a result, the mucus-containing surface and pit cells have been described primarily in terms of their nonsecreting functional state. Exceptions to this are a few transmission and scanning electron microscopy studies which describe loss of intact mucus granules, cell extrusion, and in situ degeneration. These previous ultrastructural studies describe cellular patterns, in both normal and injured mucosa, which we fell are related to mucus release. Because of a paucity of knowledge concerning the normal mechanisms of mucus secretion, it was the purpose of this study to define the ultrastructural changes which result in and accompany the production of mucus in canine gastric epithelium.

Animals↗
PubMed1978

Accuracy and consistency of pancreatography.

Pancreatography is a valuable diagnostic technic to identify structural changes in the pancreatic ductal system. Although specific diagnoses based on ductal changes are not always possible, patients with surgically normal glands and those showing changes of chronic pancreatitis were reliably identified in this series. Patients evaluated for postcholecystectomy pain usually had normal pancreatograms and grossly normal pancreatic glands at the time of surgical exploration. The overall consistency in interpretation of pancreatograms by experienced radiologists was approximately 80 per cent. Pancreatic cancer was poorly predicted due to either minimal changes in the ductal system or inability to distinguish gross changes from those seen with chronic pancreatitis.

Adult↗
PubMed1978

Oxygen consumption during cimetidine and prostaglandin E2 inhibition of acid secretion.

Oxygen consumption was determined during cimetidine and 16,16-dimethyl prostaglandin E2 inhibition of acid secretion in exteriorized segments of the greater curvature of dog stomach. Steady-state acid secretion during histamine infusion correlated well with O2 consumption (r = 0.85, P less than 0.01). Cimetidine and 16,16-dimethyl prostaglandin E2 inhibition of acid secretion produced a reduction of oxygen consumption to resting levels. In contrast, oxygen consumption did not decrease appreciably during thiocyanate inhibition of acid secretion. These observations suggest that the inhibitory action of cimetidine and 16,16-dimethyl prostaglandin E2 precedes, whereas that of thiocyanate is at a point beyond the transfer of energy to the process of acid production.

Animals↗
PubMed1977

Transampullary septectomy for post-cholecystectomy pain.

Twenty-eight patients with chronic, incapacitating upper abdominal pain after cholecystectomy had excision of the common wall between the terminal bile duct and duct of Wirsung (ampullary septum). Twenty-two also had a sphincteroplasty: six had had this procedure previously. Pancreatic function studies, scintiscans, ultrasound and pancreatograms were non-diagnositic. Hyperamylasemia was an uncommon finding. Eight patients were found to have evidence of mild pancreatitis at exploration. There was gross scarring of the ampullary septum in 22 cases. Histologic examination revealed inflammation in 12 septa; the degree of fibrosis could not be assessed since 14 control septa from autopsy material free from biliary tract disease revealed a comparable degree of collagen and smooth muscle. There were no deaths, and minimal morbidity. In follow-up from seven to 59 months (mean = 26), 16 patients are relatively free of pain, five have occasional episodes which require non-narcotic analgesics, and seven have gained no relief from the operative procedure. A randomized controlled trial is recommended.

Adult↗