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Biomedical subjects

L M Nyhus

Publications and source records attributed to L M Nyhus.

At least 109 records · Page 6Linked to original sources
PubMed1981

An unusual case of heterotopic pancreas of the stomach.

A 56 year old man had an unusual case of heterotopic pancreas of the stomach. The patient had two lesions. One was at the gastroesophageal junction, representing the highest location in the stomach reported for this lesion. The second lesion was in the prepyloric antrum and consisted of heterotopic pancreatic tissue as well as tissue consistent with heterotopic ampulla of Vater. A general review of heterotopic pancreas is presented.

Ampulla of Vater↗
PubMed1981

Influence of hiatal hernia on lower esophageal sphincter function.

Sliding hiatal hernia has long term been implicated as a cause of lower esophageal sphincter (LES) incompetence and gastroesophageal reflux. The physics of LES function in hiatal hernia were investigated in in vitro and in vivo experiments. In vitro models of sliding hernias were constructed from excised canine gastroesophageal specimens. A "sphincter" was simulated with a rubber band around the gastroesophageal junction. It was found that placement of a ligature "hernia ring" on the stomach increased the opening pressure of the model sphincter. Addition of a tissue "hernia sac" sutured to the esophagus above the sphincter further increased the opening pressure, the protective effect being related to the pressure transmitted from the stomach to the hernia sac. There was no fluid leakage from the hernia sac between the hernia ring and the stomach. In anesthetized dogs (in vivo model) gastric and esophageal pressures were measured during gastric infusion while the LES gas way to reflux. A ligature tied loosely around the stomach to simulate a "hernia ring" and a sliding hernia without a hernia sac increased both the opening and the closing pressures of the LES by 36 +/- 18% and 35 +/- 20% (mean +/- SD), respectively. The opening pressure was increased by a decrease in gastric wall tension at the gastroesophageal junction, which was caused by the decreased radius of the herniated portion of the stomach. Pressure transmitted from the stomach to the hernia sac added to the LES pressure, and thereby further increased the opening pressure of the sphincter. The results explain how gastroesophageal reflux may be prevented in patients with hiatal hernia. It was recognized that the hernia sac may protect the sphincter, provided that it inserts into the esophagus above the LES.

Animals↗
PubMed1981

Engulfment of erythrocytes by intestinocytes of the rat ileum.

The innervation of ileal mucosa of normal, unanaesthetized male Wistar rats was investigated electronmicroscopically. The presence of RBC inside intestinocytes was a secondary, but frequent observation in 4 of 20 rats. No sign of hemorrhage or trauma of the tissue was noted, and the rats had not been exposed to any known toxic agent. The study demonstrates that also intestinocytes have the capacity to engulf RBC, as many other types of epithelial cells. However, previous demonstration of RBC phagocytosis of epithelia was performed in tissues where hemorrhage had occurred for various reasons. In contrast, the rats of the present study were considered normal, although the influence of unknown agents cannot be ruled out.

Animals↗
PubMed1981

The effect of propranolol on insulin-stimulated gastric secretion in dogs.

The effect of beta-adrenergic blockade on the insulin hypoglycemia-induced gastric secretion was studied. Insulin-stimulated (0.15 IU/kg) gastric acid and pepsin output and serum gastrin were measured before and after beta-adrenergic blockade with propranolol (20 microgram/kg/min intravenous infusion) in gastric fistula and Heidenhain pouch dogs. Insulin injection caused acid and pepsin secretion from the gastric fistula, and both acid and pepsin secretion was significantly increased during beta-adrenergic blockade. Significant gastrin release was observed after insulin stimulation. However, the insulin-induced gastrin release was unaltered by intravenous infusion of propranolol. The Heidenhain pouch did not show any secretion in these experiments. It is concluded that beta-adrenergic blockade augments the hypoglycemia-induced gastric secretion in dogs. Furthermore, it seems that this effect is not dependent on vagally released gastrin.

Animals↗
PubMed1981

The lack of effect of propranolol on the intestinal phase secretion in the dog.

Four mongrel dogs were prepared with a Heidenhain pouch, a gastric fistula, and a 90-cm-long Thiry-Vella loop. After recovery, the jejunal loop was perfused for 3 h with either 5% liver extract or with 0.15 M NaCl, and measurements of gastric acid and pepsin secretion and serum gastrin levels were performed. The experiments were repeated during beta-adrenergic blockade induced by intravenous infusion of propranolol in a dose of 20 micrograms/kg/min. As control, propranolol was also given alone without intestinal perfusion. Perfusion of the jejunal loop with liver extract caused a significant acid secretion from the Heidenhain pouch and gastric fistula. In addition, significant pepsin secretion was obtained, but only from the gastric fistula. The serum gastrin levels remained unchanged during intestinal perfusion. Beta-adrenergic blockade did not influence any of these measurements. The results suggest that the intestinal-phase hormone also stimulates pepsin secretion in dogs. Furthermore, it seems that neither the release nor the action of this hormone is controlled by the beta-adrenergic nerves in the gut.

Animals↗
PubMed1981

Effect of acetylcholine and catecholamines on the enterochromaffin-like cells of the stomach.

Small pieces of fundic mucosa from rats were incubated for 15 minutes at 3 degrees C. in tissue culture medium, and the effects of acetylcholine, epinephrine and norepinephrine on the enterochromaffin-like cell were studied by electron microscopy with a morphometric study of the secretory granules. The addition of acetylcholine and norepinephrine did not cause significant changes in the secretory granules of the cell, while the addition of epinephrine caused a significant increase in the volume density of the secretory granules. This increase was associated with a significant decrease in electron opaque components within the secretory granules of the cell. The results suggest that the activity of the cells in rats is under direct adrenomedullary influence.

Acetylcholine↗
PubMed1980

Complete vagotomy. The evolution of an effective technique.

In the 36 years since the reintroduction of truncal vagotomy for the treatment of duodenal ulcer, recurrent ulcer at a rate of between 7% and 12% has become accepted as the most serious long-term postoperative complication. Although techniques for performance of complete vagotomy have been described, many of these principles of technique have been either forgotten or discarded. The new techniques of vagotomy, that is, selective and highly selective vagotomy, have realerted us to the necessity of performing a careful and wide anatomic dissection of all periesophageal tissue of the esophagogastric junction.

Duodenal Ulcer↗
PubMed1980

Sterile, portable radiation shield for the operating room.

A sterile, portable radiation shield has been developed to protect the surgeon who must remain in the operative field during radiation exposure. The shield is simple to construct and to use. There is no undue prolongation of operating time. The shield effectively reduces exposure to radiation.

Humans↗
PubMed1980

Pancreatic abscess after alcoholic pancreatitis.

Primary pancreatic abscess should be suspected in patients with acute or subsiding pancreatitis who have a tender abdominal mass with evidence of local and systemic sepsis. These individuals have a prolonged course of illness compared with patients with uncomplicated pancreatitis. Another group of patients without overt signs of sepsis may have abdominal masses thought to be pseudocysts, with unexplained temperature elevation and leukocytosis. This latter group may also have pancreatic suppuration, termed secondary because of its natural history. The distinction between primary and secondary abscesses is difficult unless time of onset of the preceding pancreatitis is known. Both groups of patients require early, thorough operation. Signs of sepsis or progressive deterioration in patients with acute pancreatitis must be recognized early since untreated abscess is usually fatal. Extensive debridement and external drainage of all abscess cavities present, preferably via posterolateral flank drain sites, are essential to successful surgical treatment of pancreatic abscess.

Abscess↗
PubMed1980

A pharmacokinetic analysis of the vagal release of 5-hydroxytryptamine in the cat.

The kinetics of 5-hydroxytryptamine (5-HT) release into the portal system after efferent electrical vagal stimulation were studied in an in vivo model. Blood samples were drawn from cats before, during and after vagal nerve stimulation, and portal plasma levels of 5-HT were measured. Portal plasma concentration of 5-HT rose during stimulation. After termination of stimulation, the plasma levels returned to steady state values and were used to calculate half-life and elimination rate constant. When pharmacokinetic principles were applied, the plasma half-life (T1/2) was determined to be 1.32 min and the elimination rate constant (KE), 0.5246 min-1. Pharmacokinetic principles also were applied to data from earlier in vitro studies using exogenously administered 5-HT, and a half-life of 1.03 min and a KE of 0.67 min-1 were calculated. Therefore, it appears that exogenously administered 5-HT and neurogenically released endogenous 5-HT are metabolized at a similar rate, both having a short half-life.

Animals↗
PubMed1980

Real-time ultrasonography during biliary surgery.

High resolution real-time B-mode ultrasound scanning using a sterile 7.5 MHz transducer was performed during operations on the biliary tract. Ultrasound is useful for locating the common bile duct in the presence of acute inflammation and other abnormal anatomy, detecting small calculi in the gallbladder with a thickened wall, measuring the caliber of the common bile duct, and identifying calculi in the common bile duct. Intraoperative ultrasonography can permit earlier and more precise appraisal of operative findings and, thereby, decrease operative time.

Biliary Tract Diseases↗
PubMed1980

Non-gastrin, intestinal-phase secretion. Experimental confirmation in the dog.

Four mongrel dogs were prepared with a Heidenhain pouch, a gastric fistula, and a 90-cm-long Thiry-Vella loop. After recovery, dose-response curves were obtained with different doses of pentagastrin, and the maximal acid output was determined. The jejunal loop was perfused for 3 h with either 5% liver extract or with 0.15 M NaCl at a rate of 114 ml/h. To verify that the stomach could release gastrin and that the assay could detect that change, antral perfusion with liver extract was performed. Serum gastrin levels and acid output were measured every 30 min. Perfusion of the jejunal loop with liver extract resulted in a significant increase in acid output from the Heidenhain pouch and the gastric fistula, whereas perfusion with saline solution failed to show any changes. The magnitude of acid response from the Heidenhain pouch and gastric fistula was 11% and 18%, respectively, as compared with maximal pentagastrin stimulation. The serum gastrin levels remained unchanged during both liver extract and saline perfusion of the jejunal loop, in contrast to the marked increase in serum gastrin level after antral perfusion. The results confirm the existence of the intestinal phase of gastric acid stimulation in dogs as an entity and show that the magnitude of this phase is significantly lower than has been suggested by results of earlier studies. Furthermore, the results suggest that the intestinal phase of gastric secretion in dogs is most probably elicited through a humoral agent other than gastrin.

Animals↗
PubMed1980

Ultrasonography of the abdominal wall in the diagnosis of spigelian hernia.

Gray scale ultrasonography of the abdominal wall was used in the evaluation of patients suspected to have spigelian hernia. This diagnostic technique was found to be accurate in displaying defects in the spigelian fascia. Application of this technique to patients with mild abdominal tenderness may result in the detection of more cases of spigelian hernia and also prevent unnecessary exploration in patients in whom the sonogram is normal.

Abdominal Muscles↗