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Biomedical subjects

F G Moody

Publications and source records attributed to F G Moody.

At least 55 records · Page 3Linked to original sources
PubMed1990

Stenosis of the sphincter of Oddi.

"Stenosing papillitis" is a descriptive term for an anatomic deformity of the papilla of Vater that is characterized by narrowing of the lower end of the bile duct and the proximal end of the duct of Wirsung. The defect is secondary to inflammation and fibrosis from the chronic passage of gallstones, episodes of acute pancreatitis, chronic pancreatitis, sclerosing cholangitis, peptic ulcer disease, and cholesterolosis. Patients with papillary stenosis from gallstones may present with episodes of severe upper-abdominal pain several years after cholecystectomy. The pain is often incapacitating, and patients are often addicted to narcotic analgesics. The work-up includes abdominal ultrasonography and CT scanning and endoscopic retrograde cholangiopancreatography even though the findings usually are normal. Liver and pancreatic enzymes are not frequently elevated with the painful episodes. Transendoscopic manometry may reveal elevated pressures within the papillary portion of the distal bile duct. Some patients are relieved of their pain by transduodenal sphincteroplasty and transampullary septectomy, thereby ablating the sphincter of Oddi around the bile and pancreatic ducts and enlarging their openings.

Cholestasis, Extrahepatic↗
PubMed1990

Biliary and gut function following shock.

The aim of this study was to characterize the alterations in gallbladder and intestinal function after hemorrhagic shock and blood reperfusion in opossums. Animals were subjected to a shock of 30 mm Hg of arterial blood pressure for 60 minutes and resuscitated with blood reinfusion. Gallbladder epithelial ion transport, gallbladder motility in vitro and in vivo, gastrointestinal motility, and flora of the stomach and small bowel were studied 2 and 24 hours after shock. Changes at 2 hours included decreased gallbladder contractility in vitro and decreased emptying in vivo, loss of coordination with intestinal motor activity, decrease in frequency of intestinal electrical slow waves, and reduced duration of the intestinal migrating motor complex cycle. By 24 hours, gallbladder epithelial permeability was increased and in vitro contractility remained reduced but the in vivo functions showed partial recovery. Gastrointestinal flora was not affected by these changes. These data demonstrate that hemorrhagic shock and reperfusion affect digestive motility. The early timing of the alterations observed and the partial recovery 24 hours post shock suggest an ischemia-hypoxia mechanism of injury.

Animals↗
PubMed1990

The propulsive behavior of the opossum sphincter of Oddi.

This study investigates whether the phasic contractions of the opossum sphincter of Oddi (SO) delay bile flow by acting as a resistor or facilitate bile flow by acting as a pump. The common bile duct (CBD) and an adjacent segment of duodenum from eight opossums were studied in a propulsion evaluation system in vitro. This system required the production of hydrostatic work by the SO to transfer fluid from the CBD to the duodenum when the pressure in the duodenum was equal or greater than the pressure in the CBD. Fluid movement from the CBD to duodenum and duodenum to CBD was studied at pressure gradients up to 50 cmH2O before and after sodium nitroprusside (10(-7) M) inhibition of smooth muscle contractile activity. All preparations propelled fluid from the CBD to the duodenum against a pressure gradient ranging from 10 to 50 cmH2O. The SO emptied the CBD in a monoexponential fashion, with a time constant of 1.52 +/- 0.7 min, until CBD pressure was reduced to 8.5 +/- 3.2 cmH2O, when propulsion ceased. Superimposed on the CBD pressure waveform were pressure pulses of 1-2 cmH2O in amplitude that resulted from the contractions of the SO. CBD pressure was higher at the start than at the end of a periodic pressure pulse, whereas CBD pressure was stable between pulses. The frequency of the pressure pulses was greatest at the maximal CBD pressure (9.4/min) and decreased significantly when the basal pressure was reached (1.5/min, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Ampulla of Vater↗
PubMed1990

Gallbladder and gastrointestinal motility after hemorrhagic shock.

The alterations in fasting gallbladder and gastrointestinal motility during hemorrhagic shock were investigated. Eight opossums implanted with a gallbladder cannula, gastrointestinal bipolar electrodes, and a carotid catheter were subjected to hemorrhagic shock of 30 mm Hg for 60 minutes by the removal of arterial blood. Shed blood was reinfused after the shock period. Fasting gallbladder volume and gastrointestinal electrical activity were studied before, immediately after, and 24 hours after hemorrhagic shock. Control measurements demonstrated a slow-wave frequency maximal in the duodenum (18.1 +/- 1.1 waves/min), with a plateau in the proximal third of the small bowel, decreasing thereafter. The migrating motor complex (MMC) had a duration of 118 +/- 28 minutes. The average volume of the gallbladder before shock was 5.4 +/- 1.5 ml. Gallbladder volume fluctuated with the MMC, being maximal during phase I and minimal in phase III. The volume of blood removed to reduce mean arterial pressure to 30 mm Hg was 45 +/- 5 ml/kg. Immediately after the shock and blood reinfusion, slow-wave frequency decreased by 40% in the antrum and 25% in the small bowel. The MMC was of shorter duration (91 +/- 22 minutes; p less than 0.05), and gallbladder volume increased to 7.0 +/- 1.7 ml (p less than 0.05). Fluctuations in gallbladder volume during the MMC were absent. Twenty-four hours after shock, slow-wave frequency, MMC, and gallbladder volume had returned to normal and were not different from control measurements. Ischemic damage to the gastrointestinal tract is postulated as the cause of gallbladder dysfunction and altered intestinal motility after hemorrhagic shock.

Animals↗
PubMed1989

Morphology of the prairie dog gallbladder: normal characteristics and changes during early lithogenesis.

Studies were undertaken to describe the normal structure of the prairie dog gallbladder and adjacent cystic duct, and then to determine sequential changes that occurred as abnormalities in bile composition developed during high cholesterol feeding. Control animals were fed a diet with trace cholesterol, while experimental animals were fed a diet enriched with 1.2% cholesterol for 1, 2, 3, or 4 weeks. Light microscopy and scanning and transmission electron microscopy were used to characterize morphologic changes at each time interval. Biliary lipid composition was altered in all experimental groups, evidenced by significant decreases in bile-acid-to-cholesterol ratios. Cholesterol crystals appeared in experimental bile at 1 and 2 weeks, while stones formed at 3 and 4 weeks. The cystic duct and neck of the gallbladder occasionally displayed goblet cells. Little mucus was demonstrable in principal cells of the gallbladder, but much more in those lining the cystic duct. After 2 weeks of lithogenic diet, there was an increase in mucus content and secretion from all areas, as well as an influx of polymorphonuclear and mononuclear leukocytes. Accumulation of plasma cells in the lamina propria was an especially prominent feature of experimental tissues. These results suggest that 1) there is regional heterogeneity in the mucus content of the gallbladder and cystic duct of the prairie dog, and 2) both regions respond to lithogenesis with mucus hypersecretion and acute and chronic inflammatory changes prior to the appearance of cholesterol gallstones.

Animals↗
PubMed1989

Lithotripsy for bile duct stones.

Fragmentation of bile duct stones by mechanical, electrohydraulic, and laser intraluminal lithotripsy has greatly facilitated the ability to remove stones that are otherwise difficult to remove by standard manipulative techniques. Even these approaches fail when stones lack access or are impacted within the biliary tree. Extracorporeal shock-wave lithotripsy (ESWL) was evaluated in the United States in a multicenter trial with 56 patients. Stone fragmentation occurred in 91 percent of patients and duct clearance in 79 percent. Adjunctive procedures were used in 54 percent. Two ESWL treatments were required for fragmentation in 28 percent. Complications were mild and relatively infrequent. Hemobilia (8 percent), gross hematuria (6 percent), and biliary sepsis (4 percent) occurred less frequently than expected. There were no deaths during the 1 to 31 days of hospitalization (mean 9 days). We conclude that ESWL is a safe and effective adjunct to the treatment of difficult-to-remove bile duct stones under the conditions observed in this trial.

Bile Duct Diseases↗
PubMed1989

The effects of lithogenic bile on gallbladder epithelium.

Prairie dogs were fed a 1.2% cholesterol diet for up to 24 weeks to evaluate the effects of lithogenic bile on the mucosa of the gallbladder. There was a progressive increase in the lithogenic index of the gallbladder bile (1.44 +/- 0.15 at 4 weeks, p less than 0.05). Fifty-five of 70 animals developed gallstones between the second and fourth week. Increasing stone burden was associated with a 27% (p less than 0.05) decrease in the electrical resistance of the epithelium and a 60% (p less than 0.05) decrease in net sodium transport when measured isotopically in an Ussing chamber (3 weeks). After 4 months, seven of ten animals developed inflammatory mucosal polyps characterized by a heavy infiltration of plasma cells into an expanded matrix. Cellular infiltration began as early as 2 weeks. These changes occurred without alterations in the ultrastructural appearance of the epithelium.

Absorption↗
PubMed1988

Role of pancreatic duct occlusion with prolamine (Ethibloc) in necrotizing pancreatitis.

There is evidence that the pancreatic duct plays an important role in the evolution of necrotizing pancreatitis. We hypothesized that occlusion of the pancreatic duct and its smaller ductules with prolamine (Ethibloc) in opossums at risk of severe necrotizing pancreatitis would have a beneficial effect on the progression of the disease. Sixteen opossums underwent bile duct ligation below the entrance of the pancreatic duct. They were divided into four groups at 6 days. Group I (control, n = 5) opossums were killed for histologic observation of the degree of necrosis of the pancreas; group II (n = 5) underwent external drainage of the pancreatic biliary duct; group III (n = 4) had external biliary drainage and ligation of the pancreatic duct; group IV (n = 7) was treated with external biliary drainage and ligation of the main pancreatic duct after instillation of prolamine. Serum amylase, lipase, and calcium values were determined. The pancreas was examined by inspection and histologically at the time of death, and the severity of the disease was determined by quantitation of pancreatic tissue necrosis. All animals in groups II and III died 8 to 14 days after bile duct ligation, and all had severe necrotizing pancreatitis. All animals in group IV survived and were killed at 2 to 10 weeks after prolamine (Ethibloc) injection into the pancreatic duct. A mild edematous pancreatitis was observed in all seven animals. Prolamine (Ethibloc) provided dramatic protection from progressive necrosis. This study does not provide an explanation, but it allows for speculation that ductal injection interrupted the deleterious effect of proteolytic enzymes and their leakage into the interstitial space of the pancreas.

Amylases↗
PubMed1988

Pancreatitis as a medical emergency.

Pancreatitis in its acute form, whether from alcohol or gallstones, can be a severe, devastating illness. Patients presumed to have the disease require aggressive fluid therapy and imaging of the pancreas by ultrasound and computed tomography (CT). They should be managed in an intensive care setting until the course of the illness is determined. Surgical intervention is reserved for cases in which extensive pancreatic necrosis or infection is demonstrated by CT scan.

Acute Disease↗
PubMed1987

The effect of preoperative internal and external biliary drainage on mortality of jaundiced rats.

Mortality following abdominal infection induced by cecal ligation and puncture was studied in rats with obstructive jaundice and after relief of the obstruction by preoperative internal or external biliary drainage. Four groups of adult Sprague-Dawley rats were used: common bile duct ligation (BDL), BDL followed by internal drainage after two weeks, BDL followed by external drainage after two weeks, and sham operation. The serum bilirubin concentration was significantly increased in the BDL group and returned to normal following internal and external drainage. Mortality in the sham group was 16.5% and increased to 83.3% following BDL, but it decreased significantly (25%) to near-normal values after preoperative internal drainage. However, after external drainage no significant reduction in mortality (63%) was found. These findings confirm the poor results of preoperative external drainage in previous studies and establish the efficacy of internal biliary drainage in a well-controlled experimental model that has to be evaluated in the clinical situation.

Animals↗
PubMed1987

Certain aspects of normal and abnormal motility of sphincter of Oddi.

Applications of electromyographic and endoscopic manometric techniques in experimental and clinical studies have enhanced our knowledge of the normal physiology and motility disturbances of the sphincter of Oddi. The sphincter of Oddi has an active role in coordinating the time and rate of secretion of biliopancreatic juice into the duodenum. In the opossum, the sphincter of Oddi exhibits spontaneous contractions that migrate distally along the sphincter and expels its contents into the duodenum. Although the motor activity of the sphincter of Oddi is independent from that of the duodenum, there is a correlation between the frequency of bursts of spike potentials in the sphincter of Oddi and the migrating motor complex phases in the duodenum. Abnormal motility of the sphincter of Oddi has been reported during endoscopic manometric evaluation of patients with choledocholithiasis and sphincter of Oddi dyskinesia. Patients with common bile duct stones have an increase in the frequency of retrograde propagation of phasic waves. Elevation of basal pressure as well as an increase in the frequency and amplitude of sphincter of Oddi phasic waves and the common bile duct-duodenum gradient pressure may occur in patients with sphincter of Oddi dyskinesia. Endoscopic manometric studies of the sphincter of Oddi may become an important method to diagnose sphincter of Oddi dyskinesia.

Ampulla of Vater↗
PubMed1987

Intestinalization of pancreatic fragments in dogs: improvement in survival rate after acute segmental pancreatitis.

Intestinalization, a new method of pancreatic preservation in which vascularized pancreatic fragments are placed inside a jejunal pouch, has been tested for its effectiveness in the prevention of shock and death due to segmental pancreatitis. Intestinalization of the fragment resulted in the survival of eight of nine animals (89 percent) in which recovery was uneventful, whereas animals with pancreatitis in situ or in a mobilized fragment without intestinalization had a mortality rate of 100 percent within 2 days. We conclude that intestinalization ameliorates the outcome of hemorrhagic pancreatitis in the pancreatic fragment by effectively draining toxic products. The procedure may also be useful in pancreatic transplantation since no reintervention is necessary if graft failure or rejection occurs because the pancreas is accessible by endoscopy.

Animals↗
PubMed1987

Calcium-induced contraction and contractile protein of gallbladder smooth muscle after high-cholesterol feeding of prairie dogs.

Feeding a high-cholesterol diet to prairie dogs causes a reduction in contractile responses of gallbladder smooth muscle from these animals. In this study, the influence of cholesterol feeding on the contractile response to calcium and on the concentration of the contractile proteins actin and myosin was determined. Strips of gallbladder smooth muscle, at their optimal length for tension development, were stimulated maximally with carbachol. Then the muscle cell membranes were made permeable and strips were exposed to a maximally effective concentration of calcium. Strips from cholesterol fed animals developed less stress than those from control animals under all conditions. The concentration of actin and myosin was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. There were no differences in the concentrations of either protein between the cholesterol-fed and control animals. Our results indicate that the decreased contractile response seen in muscle from cholesterol-fed animals is not due to alterations in membrane excitation, excitation-contraction coupling, or in total contractile proteins.

Actins↗
PubMed1987

Postcholecystectomy syndromes.

The postcholecystectomy syndrome in its chronic form is characterized by severe episodes of upper abdominal pain that may or may not be accompanied by hepatic or pancreatic dysfunction or ductal dilation. Endoscopic retrograde cholangiopancreatography is the most definitive way to identify anatomic defects. Transendoscopic papillary manometry is a promising new diagnostic technique. A surgical approach should be used only after persistence of symptoms without apparent cause and a prolonged trial of medical therapy. The operation should include exploration of the contents of the peritoneal cavity and transduodenal examination of the papilla of Vater. An extended papilloplasty should be performed to include a 1- to 2-cm anterior sphincteroplasty and an excision of the transampullary septum. Approximately 75 percent of patients with chronic pain after cholecystectomy will gain long-term relief of their symptoms.

Cholecystectomy↗
PubMed1986

Effect of feeding on myoelectric activity of the sphincter of Oddi and the gastrointestinal tract in the opossum.

The effect of different foods on the myoelectric activity of the sphincter of Oddi and gastrointestinal tract was evaluated in the opossum. Gallbladder pressure was also recorded. Feeding fat and mixed food resulted in the greatest incidence of spike activity in the duodenum and jejunum, followed by protein. The lowest incidence of slow waves with spikes in the duodenum and jejunum followed feeding of carbohydrates (P less than 0.01). Likewise, the lowest spike activity in the sphincter of Oddi was observed after carbohydrate feeding (P less than 0.05). There was no significant difference in the incidence of spike potentials in the sphincter of Oddi when fat, protein, or mixed food was fed. No significant change in gallbladder pressure during fasting and following feeding of different aliments was observed. We concluded that there is a correlation between the frequency of spike potentials in the sphincter of Oddi and in the small bowel following feeding. The duration of the fed pattern for each type of food correlated with the number of spikes in the sphincter of Oddi and gastrointestinal tract.

Ampulla of Vater↗