Search PubMed⌕ Search

Biomedical subjects

J M Howard

Publications and source records attributed to J M Howard.

At least 127 records · Page 7Linked to original sources
PubMed1977

Drug-induced acute pancreatitis.

A review of the literature reflects numerous instances of acute pancreatitis developing in patients while being treated with drugs. The causative relation is not yet definitively established but, in several instances, there appears to be a probable relation. The literature records at least 112 patients with drug-induced acute pancreatitis. Fifty-one instances were caused by steroids or adrenocorticotropic hormone, six by estrogen, two by azathioprine, 16 by diurectics, two by hypercalcemia, 24 by chemotherapy, three by clonidine and phenformin, two by warfarin and one each by salicylate, 1-asparaginase and d-propoxyphene. In addition, many patients have experienced acute pancreatitis while receiving immunosuppressive therapy after renal transplantation.

Acute Disease↗
PubMed1977

The hypocalcemic activity of pancreatic tissue homogenate in the dog.

Glucagon and the pancreatic homogenate preparations to be tested for hypocalcemic effects were injected either intravenously or intraperitoneally in thyroparathyroid intact dogs and in dogs after thyroparathyroidectomy, respectively. Evidence has been presented that, in thyroparathyroid intact dogs, pancreatic tissue homogenate and the residue of such homogenate demonstrated a maximal hypocalcemic effect and that, in the thyroparathyroid intact dog, glucagon produced a hypocalcemic effect but did not produce a significant effect on dogs after acute thyroparathyroidectomy. On the other hand, the hypocalcemic effect of residue was equally effective both in dogs after thyroparathyroidectomy and in thyroparathyroid intact dogs; there was evidence that intravenous infusion of the residue resulted in a more rapid decrease in serum calcium levels compared with the intraperitoneal infusion after thyroparathyroidectomy of dogs being maintained four to five days with parathormone. Although final conclusions are not justifiable, the results suggest that a pancreatic factor other than glucagon has hypocalcemic effects and might explain the hypocalcemia observed during acute pancreatitis.

Animals↗
PubMed1977

The effects of calcitonin on pancreatic exocrine secretion in dogs.

The effect of calcitonin on pancreatic secretion was studied in unanesthetized dogs with a Thomas cannula implanted opposite the main pancreatic duct. Pancreatic juice was collected for a 60 minute control period, during which time secretion was stimulated by the intravenous infusion of secretin and pancreozymin. After the 60 minute control period, calcitonin was infused along with the secretin and pancreozymin. The infusion of calcitonin caused the volume, bicarbonate and enzyme output in the pancreatic juice to decrease to about one-half of that during the control period. During the one hour period, after calcitonin infusion was stopped, the volume, bicarbonate and enzyme content of the pancreatic juice increased but remained slightly lower than that of the control period. The infusion of calcium gluceptate, along with secretin and pancreozymin, overcame the inhibitory effect of calcitonin on pancreatic secretion.

Animals↗
PubMed1976

Vascular permeability induced by pancreatic exudate formed during acute pancreatitis in dogs.

Acute pancreatitis was produced in five dogs by injecting bile into the pancreatic duct. The capillary permeability effects of the exudate formed within the peritoneal cavity were studied by injecting the exudate intradermally into puppies. The amount of radioactively labeled albumin escaping from the circulation and appearing at the intradermal injection site was used as a measure of capillary permeability. It was observed that the peritoneal exudate, especially that produced in the early stage of bile induced pancreatitis, contains one or more substances which result in an increased capillary permeability when injected intradermally into puppies.

Amylases↗
PubMed1975

Studies of paralytic ileus. Effects of intraperitoneal injury on motility of the canine small intestine.

This study is significant in demonstrating that the small intestine of the dog is extremely resistant to paralytic ileus. The various types of intra-abdominal irritation studied were quite severe. After a transient period of inhibition, however, in most instances motility of the small intestine returned and continued until near the time of death. Various types of intra-abdominal irritation were used to study paralytic ileus in dogs, including intraperitoneal injection of gastric juice, gastroperitoneal fistula, appendiceal ligation, intraperitoneal injection of Lugol's iodine solution, retroperitoneal injection of blood, and mechanical and thermal irritation of the intestine and peritoneum. The electrical and mechanical activity of the small intestine was observed by means of a Thomas cannula implanted in the jejunum. The presence or absence of fluid accumulation within the intestinal lumen or peritoneal cavity was noted at autopsy. Intra-abdominal chemical irritation caused a transient inhibition of intestinal motility, which was reversed when the irritation was stopped. Repeated irritation did not appear to cause progressive, irreversible inhibition of intestinal motility. When intestinal motility was depressed, spike potentials were absent in the recordings of electrical activity of the intestine. The "slow" electrical waves were distinguishable at all times. With the exception of the gastroperitoneal fistulas, the procedures were tolerated with only transient inhibition of intestinal motility. Accumulation of intraperitoneal fluid occurred in dogs subjected to gastroperitoneal fistulas. A small amount of intraluminal fluid accumulated in dogs subjected to repeated thermal and mechanical irritation of the intestines and peritoneum. In the other groups of dogs no significant increase in intestinal or intraperitoneal fluid was observed.

Animals↗
PubMed1975

An evaluation of endoscopic pancreatocholangiography in surgical patients.

Retrograde pancreatocholangiography was successful in 110 or 83 per cent of 133 patients suspected of having pancreatobiliary disease. Cannulation of the pancreatic duct was successful in 95 per cent of the patients suspected of having disorders of the pancreas. In 84 per cent, the biliary tree was successfully visualized among the group suspected of having disorders of the biliary tract. Dilatation of the main pancreatic duct in association with cholelithiasis and choledocholithiasis was observed in 33 and 72 percent, respectively.

Ampulla of Vater↗
PubMed1975

Elastase levels during bile-induced pancreatitis in dogs determined by radioimmunoassay.

The changes in elastase levels were studied in the plasma before and after bile-induced pancreatitis. Although the anylase and lipase levels increased markedly, there was no significant increase in the plasma elastase levels, as measured by enzymatic assay. On the other hand, the elastase levels of the blood in the femoral and pancreatic veins as measured by radioimmunoassay, increased to about ten times above the control levels. Similarly, in pancreatitis, large amounts of elastase, determined by radioimmunoassay, was found in the ascitic fluid. At that time, no elastase activity could be determined in the ascitic fluid. In this study, it is suggested that circulating inhibitors interfere with the determination of elastase enzymatic activity but do not interfere with the radioimmunoassay of elastase.

Acute Disease↗
PubMed1974

The effects of distention and obstruction on the accumulation of fluid in the lumen of small bowel of dogs.

Fluid accumulation in either the obstructed upper or lower intestinal segments of the dog was found in most animals to be negligible. Distention pressures of 25 cm of water tended to reduce fluid accumulation within the intestinal lumen. These studies suggest that if the dog is comparable to man, the intraluminal accumulation of fluid in the obstructed small bowel of man might be due to alterations in blood supply to the intestine, rather than to obstruction per se, or the accumulated fluid originates proximal to the jejunum.

Animals↗