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Biomedical subjects

A Ayalon

Publications and source records attributed to A Ayalon.

At least 55 records · Page 3Linked to original sources
PubMed1991

The use of radioiodinated toluidine blue for preoperative localization of parathyroid pathology.

The efficiency of preoperative radioactive toluidine blue (RTB) scintigraphy for the localization of parathyroid pathology was evaluated prospectively in 69 patients (age range, 15 to 81 years; mean, 56 years) with primary hyperparathyroidism. Four patients have previously undergone negative exploratory surgery. Patients underwent preoperative dual radionuclide parathyroid-RTB/technetium 99m (Tc 99m)-thyroid scintigraphies with a computer-interfaced gamma-camera with a pinhole collimator. Computer-acquired scintigraphic data were analyzed for parathyroid localizations by an RTB-parathyroid/thyroid superposition technique. At surgery, parathyroid adenomas were found in 64 patients (single adenomas in 60 patients; two adenomas in four patients), nine of these adenomas were mediastinal. Four patients had parathyroid hyperplasia. One patient had no parathyroid pathology (negative exploratory surgery). Correlation between the surgical-pathologic findings and the scintigraphic RTB localization studies disclosed a sensitivity of 87%, with a specificity of 94%, and an overall accuracy of 92%. The routine use of preoperative scintigraphic parathyroid-RTB/Tc 99m-thyroid localization has proved to be highly effective, enabling detection of small hyperfunctioning parathyroid glands in normal and ectopic locations in a wide range of weights. In this series a success rate of 98% was achieved on initial and reexploratory surgery for primary hyperparathyroidism.

Adenoma↗
PubMed1990

The danger of high compliance balloons for esophageal dilatation in achalasia.

High compliance balloons, commonly used for pneumatic dilatation of achalasia patients, theoretically subject the widened esophageal wall, proximal to the narrow zone, to increased pressure, and subsequently to a higher risk of perforation. The new type of inelastic cylindrically shaped balloons, such as the Gruntzig-type and Rigiflex Achalasia Dilator, seems to be safer, since it increases esophageal wall tension in the stenotic zone only. The purpose of this study was to present a pathophysiological consideration of this assumption, together with two cases which support it.

Adult↗
PubMed1990

Acetylcholinesterase and butyrylcholinesterase genes coamplify in primary ovarian carcinomas.

The genes for acetylcholinesterase (ACHE) and butyrylcholinesterase (CHE) are expressed in multiple tumor tissues, including ovarian carcinomas. Both CHE and ACHE genes coamplify in leukemias. To examine the relationship of gene amplification to the expression of these genes in tumors, ACHE and CHE genes and their expression were studied in primary ovarian carcinomas. DNA blot hybridization demonstrated a significant amplification and mutagenesis of both genes in 6 of 11 malignant tumors studied. This was greater or of the same order of magnitude as the amplification of the oncogenes c-rafi, v-sis, and c-fes in these tumors. No amplification was found in normal ovarian tissues or benign ovarian cysts. Xenopus oocyte microinjections, blot and in situ hybridizations, and immuno- and cytochemical staining revealed translatable CHEmRNA and its active protein product in discrete tumor foci. The frequent coamplification in ovarian carcinomas of ACHE and CHE genes implicates cholinesterases in neoplastic growth and/or proliferation.

Acetylcholinesterase↗
PubMed1990

UW solution improves duration and quality of clinical liver preservation.

Prolonged liver preservation (up to 17 hours) with UW solution had no adverse effect on perioperative blood loss or results of postoperative serum biochemistry studies. After use of this solution, biliary and vascular complications as well as evidence of histologic damage were less. The advantages of the extended preservation time permit liver transplantation to be done as a semi-elective procedure; more patients can be waiting at home instead of near the transplant center. The availability of UW solution also makes it possible to send grafts long distances throughout the nation. Furthermore, surgeons can arrange for backup patients in case the recipient proves to be inoperable. This capability should reduce organ wastage, even before the time limits of preservation with UW solution have been determined definitely. We feel that UW solution undoubtedly has improved both the duration and quality of liver graft preservation.

Adenosine↗
PubMed1989

[Repair of large abdominal wall defects with expanded polytetrafluoroethylene].

Most abdominal wall defects can be repaired by primary closure. However, when the defect is so large that there is tension on closure, use of prosthetic material is indicated. Expanded polytetrafluoroethylene has the advantages of low rates of infection, foreign body reaction and adhesion formation, making it the material of choice for repair of large abdominal wall defects.

Abdominal Muscles↗
PubMed1988

Splenic artery aneurysms in liver transplant patients.

We found splenic artery aneurysms in 6 of 71 consecutive patients who underwent orthotopic liver transplantation at the Mayo Clinic. The incidence of splenic artery aneurysms in cirrhotic patients with portal hypertension was 10%. Five of the aneurysms were found in patients suffering from chronic active hepatitis, whereas no aneurysms were encountered in patients with primary sclerosing cholangitis or primary biliary cirrhosis. One patient ruptured a splenic artery aneurysm shortly after liver transplantation, and 1 patient developed an aneurysm 3 months after transplantation. We recommend coeliac angiography to be performed prior to liver transplantation, and if splenic artery aneurysms are found, ligation of the splenic artery should be performed at the time of transplantation to prevent possible rupture.

Adolescent↗
PubMed1986

Surgical aspects of gastrointestinal persimmon phytobezoar treatment.

One hundred thirteen patients presented with gastrointestinal complications due to persimmon phytobezoars during a 3 year period. One hundred three patients had a history of persimmon ingestion. One hundred five patients had undergone previous gastric operation for duodenal ulcer, one patient underwent highly selective vagotomy, and seven patients had not undergone previous operation. An elevated temperature, leukocytosis, and decreased bowel sounds were typical early clinical manifestations of small bowel obstruction by persimmon phytobezoars. In 13 patients, gastric bezoars were found, in 20 patients, gastric and intestinal bezoars, and in 80 patients, intestinal bezoars. One hundred patients were treated surgically. In 14 of the 20 patients with concomitant gastric and intestinal phytobezoars, extraction of the bezoars was achieved by gastrotomy. Of the remaining six patients, it was achieved by intraoperative milking of the gastric bezoar into the small bowel in two patients and by conservative treatment in four patients. Of the 100 patients who presented with small bowel obstruction, 60 were treated by milking of the bezoar into the large bowel, 34 by enterotomy, and 6 by conservative therapy with intravenous fluids, gastric suction, and a water-soluble contrast meal. Small bowel resection of a gangrenous segment was necessary in two patients. Two patients died after operation because of sepsis and respiratory complications. Eleven of the 13 patients in whom postoperative wound infection developed underwent gastrotomy or enterotomy. We conclude that the treatment of choice of intestinal obstruction due to persimmon phytobezoars is milking of the bezoar into the large bowel without enterotomy. Preoperative or operative endoscopy should be performed in patients presenting with complications of gastrointestinal phytobezoars. Patients who have undergone gastric operation should be warned against the risk of persimmon ingestion.

Bezoars↗
PubMed1986

Pouch ileitis--recurrence of the inflammatory bowel disease in the ileal reservoir.

"Pouchitis" is an inflammation of the ileal pouch that has been described as occurring after Kock's procedure--the continent ileal pouch. The case presented herein demonstrates clinical and histological features that resemble ulcerative colitis, implying that this disorder may be a recurrence of the patient's original inflammatory bowel disease and not merely a local and nonspecific process as previously suggested.

Adult↗
PubMed1984

Percutaneous transhepatic therapy of bile duct stones and strictures.

Two patients, one with bile duct stones above a strictured biliary-enteric anastomosis, and the second with posttraumatic intra- and extrahepatic bile duct strictures, were treated via the percutaneous transhepatic route. The stones were removed and the strictures dilated. Surgery was unnecessary in the first patient, and in the second, exploratory laparotomy confirmed the efficacy of percutaneous transhepatic dilatation.

Adult↗
PubMed1983

Regulation of pepsinogen release from canine chief cells in primary monolayer culture.

To study the regulation of pepsinogen secretion by chief cells, we have developed techniques for the isolation, enrichment, and short-term culture of chief cells from canine stomach. The fundic mucosa was enzyme dispersed and chief cells were enriched to a content of about 70% using an elutriator rotor. After 36 h in culture confluent monolayers formed that were highly enriched in chief cells. Carbachol induced a time-dependent release of pepsinogen into the medium, with about a threefold increase in pepsinogen secretion over controls found after 60 min of incubation. Carbachol stimulation of pepsinogen secretion was dose dependent, with 5 microM producing 50% of the maximal response found at a carbachol concentration of 100 microM. Atropine (100 microM) produced a rightward shift of the dose-response curve, indicating the presence of a muscarinic receptor. Dibutyryl cAMP, 8-bromo-cAMP, and forskolin also markedly stimulated pepsinogen secretion. Secretin and vasoactive intestinal peptide (VIP) stimulated pepsinogen secretion, but the response were of smaller magnitude than found with carbachol or the cAMP analogues. The phosphodiesterase inhibitor isobutylmethylxanthine also caused a small stimulation of pepsinogen secretion but did not enhance the response to secretin or VIP. These findings indicate that epithelial monolayers can spontaneously form from isolated canine chief cells and retain functional differentiation evident by a response to stimulation. Canine chief cells in culture possess muscarinic and secretin receptors and respond to cAMP.

1-Methyl-3-isobutylxanthine↗
PubMed1983

An unusually high incidence of gastrointestinal obstruction by persimmon bezoars in Israeli patients after ulcer surgery.

Seventy-seven patients presented with gastrointestinal obstruction due to phytobezoars during a 5-mo period. Most of the patients (88.3%) had a history of persimmon ingestion, and all had previous surgery for ulcer disease. Seventy-one patients were treated surgically; 67 because of intestinal obstruction and 4 for extraction of gastric phytobezoars. Five patients were reoperated once and 1 patient twice because of retained phytobezoars. Six patients were treated conservatively. Seventy-five patients recovered after surgical or conservative therapy, and 2 patients died. Patients who have undergone gastric surgery should be warned about the risk of persimmon ingestion.

Adolescent↗
PubMed1982

Electrical effects of histamine on monolayers formed in culture from enriched canine gastric chief cells.

To develop techniques for studying transport properties and secretory function of selected cell types in the gastric mucosa, separated fractions of dispersed canine fundic mucosal cells were placed in short-term culture to form epithelial monolayers. Cell fractions enriched in either chief, parietal, or mucous cells were prepared by using counterflow centrifugation and were plated on type I collagen. An epithelial monolayer formed by approximately equal to 36 hr. Immunofluorescence with an antipepsinogen I antibody revealed pepsinogen-containing granules in greater than 95% of the cells, regardless of whether the monolayers were formed from the mucous, chief, or parietal cell-enriched fractions. Upon achieving confluency, chief cell monolayers were mounted in Ussing chambers to study their electrical properties. Under basal conditions, monolayers (n = 6) had a spontaneous potential difference (PD) (+/- SEM) of 26 +/- 4 mV (apical surface negative), a short-circuit current (Isc) (+/- SEM) of 16 +/- 2 microA/cm2, and a transepithelial resistance (R) (+/- SEM) of 1,480 +/- 210 omega X cm2. Histamine increased the short-circuit current, an effect blocked by an H2-receptor antagonist. Seventy percent of the spontaneous PD was amiloride sensitive, suggesting sodium absorption accounted for a major component of the PD. These preparative techniques yield highly enriched chief cell monolayers, which maintain morphological and functional cellular differentiation for greater than 48 hr in culture, thus allowing study of oriented functions of a selected cell type. The present studies indicate that an H2 receptor enhances electrogenic ion transport in chief cell monolayers, indicating that histamine can act on fundic mucosal cells other than just parietal cells.

Animals↗