Neuroendocrine gut neoplasms. Important lessons from uncommon tumors

OBJECTIVE

To review our experiences in order to high-light some important lessons learned in the treatment of patients with neuroendocrine gut neoplasms.

DESIGN

Retrospective analysis of case series of 70 patients with neuroendocrine gut neoplasms treated between 1983 and 1993. The clinical features of individual patients illustrate lessons in surgical treatment.

SETTING

University hospitals with tertiary care referral practice.

INTERVENTIONS

The main intervention was abdominal exploration in 43 patients, with resection of the primary tumor in 39 and of hepatic metastases in four.

MAIN OUTCOME MEASURES

To describe the tumors seen and to identify major lessons learned.

RESULTS

Of 70 patients with neuroendocrine tumors treated, 31 had carcinoid tumors, 10 each had insulinomas and gastrinomas, five had vipomas, nine had non-functioning islet cell tumors, three had glucagonomas, and one each had somatostatinoma and a possible cholecystokinin-secreting tumor (or CCKoma). Important lessons learned include: (1) the importance of preoperative tumor localization; (2) in multiple endocrine neoplasia, type I syndrome, the tumor found may not be the one responsible for the patient's symptoms; (3) solitary sporadic tumors secreting multiple peptides may mimic multiple tumors in multiple endocrine neoplasia, type I syndrome; (4) one needs to be prepared for the unexpected, such as the carcinoid crisis; (5) resection may sometimes be necessary even with advanced local disease; and (6) selected patients may benefit from pancreaticoduodenectomy.

CONCLUSIONS

These rare tumors are interesting in their clinical presentation and can be challenging in their treatment.

Noninvasive method for the detection of bowel ischemia: computed tomography detection of absorbed iodinated contrast material

RATIONALE AND OBJECTIVES

Although systemic absorption of enterically administered iohexol and its excretion in urine has been previously documented in rats with ischemic bowel, a practical and sensitive method of detecting urinary iohexol has not been available. We proposed to detect the presence of iohexol in the urine of rats with normal and ischemic bowel by use of a computed tomography (CT) number increase in the bladder with the use of CT.

METHODS

Anesthetized rats (250 g) underwent either sham laparotomy (n = 6), ligation of two vascular arcades to the proximal jejunum (n = 5), ligation of six vascular arcades to the proximal jejunum (n = 6), or ligation of the superior mesenteric artery (n = 6). Rats were hydrated with saline (3.2 ml/hr intravenously). Each received a 3-ml enteric bolus of isotonic iohexol. Serial CT scans and plain film radiographs of the bladder were performed at 2, 4, and 6 hr to detect systemic absorption of contrast from the gut. Urine iohexol concentrations were measured by capillary electrophoresis. CT number and iohexol concentration were compared with evidence from plain film radiographs of bladder opacification. Intestinal ischemia was graded histologically.

RESULTS

Histologic evidence of ischemia was present in all six-arcade and five of six superior mesenteric artery (SMA)-ligated animals. No animals in the control or two-arcade group showed evidence of bowel ischemia. Statistically significant increases (P < 0.05) in bladder density were demonstrated in the six-arcade and SMA-ligated groups. No statistical difference was noted between the two-arcade ligation and control groups.

CONCLUSIONS

Experimental intestinal ischemia was reliably detected by bladder opacification after administration of enteric contrast. CT detection of systemic absorption of enteric iohexol was more sensitive than plain film radiographs and may be useful in the diagnosis of intestinal ischemia, although it may not be specific for ischemia.

Laparoscopic management of gallstone disease

The development of laparoscopic cholecystectomy has had a major impact on the management of patients with biliary tract disease. The evidence today suggests that the procedure is safe, effective, and has special advantages over open cholecystectomy in terms of patient discomfort and postoperative convalescence. Laparoscopic cholecystectomy has become the treatment of choice for patients with symptomatic cholelithiasis. However, the availability of this minimally invasive approach to gallstones should not alter the indications for operation. Minimally invasive techniques are increasingly being adapted to the management of patients with other biliary tract problems, including acute cholecystitis and choledocholithiasis. Continued surveillance of outcomes is warranted to ensure that these procedures are being applied safely and appropriately.

Postgastrectomy syndromes: dumping and diarrhea

This article reviews the current literature on the postgastrectomy syndromes of dumping and postvagotomy diarrhea. Pathophysiology, diagnosis, incidence, and treatment options are discussed. These syndromes present some of the most difficult treatment dilemmas seen after surgery. Specific recommendations for both medical and surgical treatments are included.

A role for calcitonin gene-related peptide in protection against gastric ulceration

OBJECTIVE

The goal of this investigation was to determine the role of calcitonin gene-related peptide (CGRP) in gastric mucosal resistance to ulceration.

SUMMARY BACKGROUND DATA

CGRP is a 37-amino acid peptide found in the peripheral ends of afferent gastric neurons. CGRP is known to inhibit acid secretion, stimulate mucosal blood flow, and stimulate release of somatostatin.

METHODS

The release of CGRP in response to intragastric and intra-arterial administration of capsaicin in the isolated, vascularly perfused rat stomach was measured by radioimmunoassay. The molecular forms of CGRP released were analyzed by gel filtration chromatography. The effect of intravenous CGRP or intragastric capsaicin on gastric ulceration induced by 100 mmol/L HCl and indomethacin was studied in intact and endogenous CGRP-depleted rats.

RESULTS

Intra-arterial capsaicin (concentration range, 10(-7) to 10(-5) mol/L) stimulated a prompt and sustained release of immunoreactive CGRP, of which 84% coeluted with rat 1-37 CGRP I by gel filtration. Intragastric capsaicin (range, 10(-5) to 10(-4) mol/L) failed to release CGRP into the vascular perfusate. In intact rats, intragastric capsaicin (10(-6) mol/L) or intravenous CGRP I (10 micrograms/kg/hr) reduced the number and area of mucosal lesions caused by HCl and indomethacin compared with the findings in control rats. Rats depleted of endogenous CGRP were more susceptible to gastric ulceration than were normal rats. Intragastric capsaicin failed to protect the mucosa of CGRP-depleted rats, whereas exogenous intravenous CGRP was effective.

CONCLUSIONS

These data support the hypothesis that CGRP released from gastric enteric neurons mediates gastric mucosal resistance to ulceration by noxious agents.

Vagal stimulation of rat exocrine pancreatic secretion occurs via multiple mediators

BACKGROUND

The vagus nerve contains cholinergic and noncholinergic neurons that interact with peptidergic neurons of the enteric nervous system, which stain immunohistochemically for cholecystokinin, vasoactive intestinal polypeptide, and gastrin-releasing peptide.

METHODS

The role of these pancreatic exocrine secretagogues during electrical vagal stimulation was studied using specific inhibitors in urethane-anesthetized rats.

RESULTS

The pancreatic secretory response to vagal stimulation was blocked significantly by each of the following: the ganglionic blocker hexamethonium (100% inhibition); the muscarinic, cholinergic blocker atropine (85% inhibition); the specific cholecystokinin A-receptor antagonist L-364,718 (84% inhibition); a gastrin-releasing peptide-receptor blocker (91% inhibition); and a vasoactive intestinal polypeptide polyclonal antibody (89% inhibition). The response was not altered by a monoclonal antibody to somatostatin. A subthreshold dose of cholecystokinin octapeptide augmented the response to electrical vagal stimulation.

CONCLUSIONS

Suppression of tonic somatostatin release is not the final common event. The findings that subthreshold cholecystokinin augments vagal stimulation, together with marked inhibition by each antagonist used, are consistent with the hypothesis that potentiating interactions among several agonists mediate the vagal response in anesthetized rats. However, this study does not exclude acetylcholine as the final common mediator. Studies in conscious animals are needed to determine the physiological significance of these observations.

Perioperative use of octreotide in gastrointestinal surgery

The evolution of gastrointestinal endocrinology has led to the design and application of analogs of gut peptides to treat disease. Octreotide, a long-acting analog of the inhibitory peptide somatostatin, has proven useful in the management of disorders such as carcinoid syndrome and secretory diarrhea due to VIPoma. More recent experience suggests a role for this peptide in the management of certain complications of gastrointestinal surgery. Prophylactic use of octreotide appears warranted in the prevention of carcinoid crisis in selected patients with carcinoid syndrome undergoing invasive procedures, and in the prevention of complications in selected patients undergoing pancreatic surgery. Evidence from placebo-controlled trials supports a role for octreotide in the management of dumping symptoms in severely affected patients, at least in the short term. Octreotide appears to serve a useful adjunctive role in controlling output from postoperative gastrointestinal fistulae and may hasten closure, particularly in pancreatic fistulae. Selected patients with ileostomy diarrhea and short bowel syndrome benefit from octreotide treatment, but the long-term value of the peptide in controlling stool output is less clear. Rare patients with other forms of postoperative secretory diarrhea have been successfully treated with octreotide. Finally, animal and early human experience suggests that octreotide may have a role as an adjunctive treatment of partial small bowel obstruction. In most of these conditions, the available data is sparse and further controlled trials are warranted.

Selective release of somatostatin by calcitonin gene-related peptide and influence on pancreatic secretion

Calcitonin gene-related peptide is a potent inhibitor of stimulated pancreatic exocrine secretion in vivo. The mechanism of this inhibitory action was studied in dogs and rats. The questions examined were: (1) is the inhibitory action of CGRP on pancreatic secretion mediated by somatostatin? (2) is the inhibition direct, via action on acinar cells, or indirect? and (3) is a neuronal mechanism involved, and, if so, by what pathway? In dogs with chronic pancreatic fistulae, CGRP caused significant inhibition of the outputs of pancreatic protein (63-68%) and of pancreatic bicarbonate (74-89%) and a simultaneous dose-related rise (40-102 fmol/ml) in plasma somatostatin-like immunoreactivity. A similar degree of inhibition was found when exogenous somatostatin was infused to achieve similar levels of plasma somatostatin-like immunoreactivity. More direct evidence of somatostatin mediation of CGRP action was sought in conscious rats with pancreatic fistulae using a potent and specific monoclonal antibody to somatostatin. The latter studies suggest that CGRP has both a somatostatin-dependent and a somatostatin-independent mechanism of action. In isolated rat acini, CGRP did not inhibit CCK-stimulated amylase release, suggesting that its in vivo action is indirect. In the isolated vascularly perfused rat pancreas, CGRP (10(-10)-10(-7) M) inhibited in a dose-dependent manner volume and protein output stimulated by a mixture of CCK-8 and secretin. The inhibitory action of CGRP was blocked by tetrodotoxin (10(-7) M) and by atropine (10(-7) M), but not by hexamethonium (10(-7) M). We conclude that CGRP action: (1) is partly explained by release of somatostatin; (2) is indirect; (3) is neurally mediated; and (4) involves cholinergic muscarinic neurons within the pancreas.

How secure are laparoscopically placed clips? An in vitro and in vivo study

We tested the security of laparoscopic, hemostatic clips in vitro and in vivo. In vitro, the force needed to transversely dislodge clips that were applied to silicone (Silastic) tubing ranged from a mean +/- SEM of 1.81 +/- 0.07 N (Endo Clip) to 2.68 +/- 0.04 N (Ligaclip). The force needed to axially dislodge clips that were applied to silicone tubing ranged from 4.08 +/- 0.20 N (Endo Clip) to 4.78 +/- 0.18 N (Ligaclip). In vivo, on mesenteric vessels in anesthetized pigs, 34 of 100 clips that were applied laparoscopically with the Endo Clip were moved or dislodged compared with 11 of 100 of those applied with the Ligaclip. We conclude that laparoscopically placed vascular clips applied with the Ligaclip are more secure than those applied with the Endo Clip. The laparoscopic surgeon should be aware of the relative ease with which clips may be dislodged.

The efficacy and limitations of percutaneous endoscopic gastrostomy

We analyzed 64 percutaneous endoscopic gastrostomy procedures performed by us between 1986 and 1990. Thirty patients had neurologic disease; 16 had head and neck cancers; eight had other malignancies; two had acquired immunodeficiency syndrome; and eight had other problems. Seven patients died within 30 days of complications (n = 4) or the primary illness (n = 3). Mean follow-up was 6 months; an additional patient died of aspiration and eight others died of their underlying illness. There were 19 complications (32%). Four wound complications occurred. Nine patients developed aspiration pneumonia within 3 days of the procedure, four of whom died in the hospital. Of the 24 patients with a history of aspiration, nine experienced aspiration during or after percutaneous endoscopic gastrostomy. Patients with a history of aspiration were more likely to have perioperative aspiration pneumonia, and patients who experienced aspiration were more likely to die.

Improvement in survival of mice with proximal small bowel obstruction treated with octreotide

Small bowel obstruction is a common disorder in surgical practice. The major morbidity of bowel obstruction relates to intestinal distension and ischemia. We hypothesized that octreotide, a potent inhibitor of gut secretion, would reduce mortality in a mouse model of lethal small bowel obstruction. C57 mice were anesthetized with urethane and prepared with either proximal jejunal or distal ileal obstruction. After 8 hours, surviving mice were randomized to receive either octreotide (100 micrograms/kg) or saline subcutaneously every 8 hours. Octreotide significantly improved survival in mice with proximal obstruction by life table analysis. Mean survival increased from 31 +/- 3 to 41 +/- 4 hours. In distal obstruction, octreotide treatment resulted in a trend towards improved survival; however, this trend failed to reach statistical significance by life table analysis. The improvement in survival in this mouse model suggests that octreotide may be a valuable adjunct in the treatment of patients with small bowel obstruction.

Control of dumping symptoms by somatostatin analogue in patients after gastric surgery

Octreotide acetate is a long-acting analogue of the naturally occurring inhibitory gastrointestinal peptide, somatostatin. We tested the efficacy of octreotide in controlling the symptoms of dumping syndrome in response to a provocative meal in a randomized, double-blinded, crossover trial in nine severely affected patients. Pretreatment with octreotide acetate (100 micrograms injected subcutaneously) reduced postprandial dumping symptoms from a mean +/- SEM score of 15.7 +/- 1.6 (placebo treatment day) to 4.6 +/- 1.7. With placebo treatment, all nine patients became symptomatic in response to the meal, whereas with octreotide treatment, symptoms occurred in only two of nine patients. Similarly, all placebo-treated patients showed a postprandial increase in pulse rate to a mean +/- SEM of 105 +/- 6 beats per minute, whereas only one of nine octreotide-treated patients showed an increase in pulse rate (mean +/- SEM, 80 +/- 3 beats per minute). These differences were also statistically significant. While no significant changes were observed in postprandial hematocrit values or osmolality between placebo and octreotide treatments, octreotide prevented hypoglycemia in four affected patients and significantly inhibited insulin release. We conclude that octreotide is a useful tool in the treatment of patients with severe, refractory dumping syndrome.

Alternating hepatic intra-arterial floxuridine and fluorouracil: a less toxic regimen for treatment of liver metastases from colorectal cancer

Hepatic intra-arterial (HIA) infusion of floxuridine (FUDR) via an implanted pump has shown promise in the treatment of colorectal cancer metastasized to the liver. However, the potential benefit of this therapy may be offset by the high incidence of treatment-limiting biliary toxicity. Although weekly HIA bolus of fluorouracil (5-FU) is effective against metastatic colorectal cancer to the liver with no biliary toxicity, it is limited by systemic side effects. In December 1986, we began a phase II trial of alternating HIA FUDR and 5-FU via the implanted pump in an attempt to extend the duration of treatment by obviating the limiting biliary (FUDR) and systemic (5-FU) drug toxic effects. Patients received continuous HIA FUDR at 0.1 mg/kg of body weight per day on days 1 through 8 followed by an HIA bolus of 5-FU at 15 mg/kg given via the pump sideport on days 15, 22, and 29, with the cycle repeated every 35 days. Sixty-eight patients were enrolled in this trial, and 64 were fully evaluable. Of the 64 patients, 30 (47%) previously had received chemotherapy. Major response (complete response plus partial response) was observed in 32 (50%) of 64 patients, and the median survival from pump implantation in all patients was 22.4 months. In contrast to the experience with the single-agent HIA FUDR regimen, no patient had treatment terminated because of drug toxicity. Alternating HIA FUDR and 5-FU has efficacy similar to that of HIA FUDR given alone, but when closely monitored and adjusted appropriately, is not associated with toxic effects requiring treatment termination.

Neuroendocrine design of the gut

The enteric nervous system (ENS) can be thought of as the third component of the autonomic nervous system. It is a vast network of neurons widely dispersed throughout the gut. The ENS is a dominant regulator of gut function through the action of peptide and non-peptide neurotransmitters. The most intensively studied roles of the ENS have been the regulation of secretory processes, such as gastric acid secretion, and motility. It is clear, however, that the ENS plays a broader role in the regulation of other gut functions, including mucosal defense, the gut immune response, and sphincter function. Alterations in the regulation of gut function by the ENS are likely or suspected in a number of conditions, including achalasia, Hirschsprung's disease, inflammatory bowel disease, Chagas' disease, chronic intestinal pseudoobstruction, biliary dyskinesia, tachygastria, and irritable bowel syndrome. Improved knowledge of the pathophysiology of these troublesome conditions makes effective therapy more likely in the future.

Calcitonin gene-related peptide inhibits exocrine secretion from the rat pancreas by a neurally mediated mechanism

The mechanism by which calcitonin gene-related peptide (CGRP) inhibits exocrine secretion from the rat pancreas was examined in the isolated, vascularly perfused pancreas and in vitro using freshly isolated pancreatic acini. CGRP (10(-10)-10(-7) M) inhibited the volume and protein output from the perfused pancreas, stimulated by a mixture of the cholecystokinin octapeptide CCK8 (10(-10) M) and secretin (10(-8) M). The inhibition by CGRP was dose related and maximal at 10(-8) M (P less than 0.05). CGRP (10(-8) M) failed to inhibit amylase secretion from isolated pancreatic acini, stimulated by graded concentrations of CCK8 (10(-13)-10(-8) M). This implies an indirect mechanism of inhibition. The mechanism of inhibition was investigated in the isolated, vascularly perfused pancreas using tetrodotoxin, atropine and hexamethonium (all 10(-7) M). Tetrodotoxin and atropine but not hexamethonium prevented the inhibition of volume and protein secretion by CGRP (10(-8) M) (P less than 0.05). Tetrodotoxin, atropine and hexamethonium were without effect on exocrine secretion stimulated by CCK8 and secretin (controls). These results indicate that CGRP inhibits pancreatic exocrine secretion by an indirect, neurally mediated mechanism involving cholinergic-muscarinic transmission.

Somatostatin inhibits pancreatic exocrine secretion via a neural mechanism

The mechanism of inhibition of pancreatic exocrine secretion by somatostatin is unknown. We hypothesized that somatostatin acts indirectly, via intrinsic pancreatic neurons, to inhibit pancreatic exocrine secretion. To test this hypothesis, amylase and volume outputs in response to secretin (10(-8) mol/L) and cholecystokinin octapeptide (CCK) (10(-8) mol/L) were studied in the rat isolated, perfused, pancreas model. Somatostatin (10(-7) mol/L) significantly inhibited amylase output by 48% compared with control (352 +/- 57 v 676 +/- 85 U/30 min, P less than .05 by ANOVA). Blockade of axonal neuronal transmission by tetrodotoxin (10(-7) mol/L) completely abolished the inhibitory effect of somatostatin (992 +/- 53 U/30 min). Similar effects were seen on volume output. The inhibitory effect of somatostatin on amylase output was not affected by cholinergic receptor blockade with atropine (328 +/- 65 U/30 min) or by sympathetic ganglionic blockade with hexamethonium (360 +/- 68 U/30 min). This suggests that the intrinsic pancreatic neurons responsible for the inhibitory effect of somatostatin are peptidergic. The possibility that somatostatin acts directly on the acinar cell to inhibit exocrine secretion was tested by incubating varying doses of somatostatin (10(-12) to 10(-7) mol/L) with isolated pancreatic acini in the presence of graded concentrations of CCK (10(-12) to 10(-10) mol/L). In this model, CCK alone is a potent stimulant of amylase release, with a Km of 6 X 10(-12) mol/L and a Vmax of 22 +/- 3% total amylase. In this model, somatostatin had no inhibitory effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Ontogeny of the smooth muscle response to histamine in rabbit and human small bowel

Histamine is known to stimulate small bowel smooth muscle contraction in adults. We studied the response to histamine of small bowel from 27 day gestation fetal (term = 31 days), 4 days-old neonatal, and weanling rabbits using an isolated muscle strip technique in vitro. Sensitivity to histamine stimulation decreased with increasing age, with a six-fold difference in mean D50 between fetal and weanling bowel. A strong contractile response was also obtained in human fetal bowel between 16 and 24 weeks gestation. The response to histamine was inhibited at all ages in both rabbit and human bowel by specific histamine H1 receptor blockade with diphenhydramine, and not by H2 or cholinergic receptor blockers. We conclude that histamine stimulates rabbit and human fetal small bowel contraction; stimulation specifically occurs via the histamine H1 receptor, and is unrelated to release of acetylcholine; sensitivity to histamine decreases significantly with maturity in the rabbit.

Characterization of in vivo acid secretory responses of rabbit with comparison to dog and rat

Even though rabbit gastric glands are a commonly used model for the study of gastric physiology, little is known about the secretion of gastric acid in the rabbit in vivo. Gastric acid secretion in response to pentagastrin, histamine, and bethanechol stimulation, and the effect of specific cholinergic and histamine H2-receptor blockers was studied in 62 urethane-anesthetized rabbits. Additionally, the responses of eight conscious rabbits prepared with chronic gastric fistula were compared with similarly prepared conscious dogs (n = 10) and conscious rats (n = 18). In anesthetized rabbits, maximal pentagastrin stimulation resulted in acid outputs only 22% that of maximal histamine stimulation, but this was enhanced by restoring cholinergic tone with a subthreshold infusion of bethanechol. In conscious rabbits, pentagastrin was an effective stimulant, resulting in maximal acid output 70% that of maximal histamine stimulation. This is in contrast to the in vitro findings reported reported by others utilizing isolated gastric glands and cells. Histamine was a potent stimulant of acid secretion in both the anesthetized and conscious rabbit, an observation that parallels the in vitro findings. Unlike the dog and rat, atropine was ineffective as an inhibitor of histamine-stimulated acid secretion in the conscious rabbit, although it was marginally effective against histamine in anesthetized rabbits and against pentagastrin in conscious rabbits. It is concluded that cholinergic tone plays a crucial role in pentagastrin-stimulated acid secretion in the rabbit. This may be an explanation for the poor response to pentagastrin described in isolated rabbit gastric gland preparations.

Trophic effect of amniotic fluid on cultured fetal gastric mucosal cells

This study examines the hypothesis that the growth and development of fetal gastric epithelial cells is critically dependent on the presence of trophic factors in amniotic fluid. Fetal gastric epithelial cells (predominantly parietal cells) were grown in culture in the presence of graded concentrations of rabbit amniotic fluid, fetal bovine serum, or a control solution containing the nutrients specific to amniotic fluid. After 7 days, cells were harvested and growth was assessed by cell counts and DNA contents. Amniotic fluid stimulated growth of these cultured cells with a potency similar to that of fetal bovine serum. Cell growth was significantly enhanced by amniotic fluid at each dose tested, when compared to the appropriate nutrient control group. Cell growth could not be maintained in the absence of amniotic fluid or fetal bovine serum. We conclude that amniotic fluid contains factors which are trophic to the growth of cultured fetal gastric epithelial cells. The nature of these factors remains to be determined.

Surgical disorders of the pancreas in infancy and childhood

Pancreatic disorders in infants and children encountered over a 20 year period are reviewed. A total of 79 children were treated. Forty-eight had pancreatitis or its complications, 17 had congenital malformations, 12 had hypoglycemia and hyperinsulinism, and 2 had carcinoma. The mortality rate for the children with pancreatitis was 17 percent and was limited to patients treated nonoperatively. Idiopathic and drug-induced pancreatitis (the latter, particularly from corticosteroids) were the predominant types. Only rarely should such patients undergo operative treatment. Operations performed for various obstructive or traumatic lesions of the pancreas, as well as for complications of pancreatitis, obtained uniformly good results. The most common congenital malformation of the pancreas was an annular pancreas in association with duodenal atresia; all children with this abnormality were successfully treated with bypass procedures. Four patients with an ectopic pancreas underwent successful wedge resection. Nine infants with nesidioblastosis or islet cell hyperplasia and three children with islet cell adenomas underwent successful resection without any deaths, although neurologic sequelae due to prolonged preoperative hypoglycemia were common. Two patients underwent radical resection for pancreatic carcinoma, one of whom had survived 20 years postoperatively at last follow-up. Pancreatic disorders requiring operation in childhood are uncommon, but are likely to be complex and challenging when they do occur.

The effect of somatostatin on experimental intestinal obstruction

The effect of somatostatin (SS-14) was tested in an anesthetized rabbit model of closed-loop ileal obstruction. Experimental groups included (1) immediate treatment (N = 6) receiving SS-14 2,000 pmol X kg-1 X h-1 intravenously (I.V.) beginning at the time of ileal obstruction, (2) delayed treatment (N = 5) receiving SS-14 beginning 6 hours following ileal obstruction, and (3) control (N = 6) receiving only hydration. After 24 hours, all rabbits were killed. Significantly decreased intestinal luminal volume and sodium and potassium output was observed with both immediate and delayed SS-14 treatment when compared to control. Additionally, the gross and microscopic pathologic features of intestinal distension, inflammation, and necrosis seen in control rabbits were absent in rabbits treated with SS-14. The known broad spectrum of physiologic activity of SS-14 on the gastrointestinal tract appeared beneficial in this rabbit model of intestinal obstruction.

Surgical management of pancreatitis in childhood

In a retrospective study of patients 18 years of age and younger over a 28-year period, 48 children had pancreatitis. Epigastric pain, nausea, and emesis were present in 90%. Hyperamylasemia was present in 34 children; elevated amylase/creatinine clearance ratio was helpful in diagnosing ten others. In four children, pancreatitis was diagnosed at laparotomy. Etiology of the pancreatitis was idiopathic in 16, drug-induced in 12, all of whom had received corticosteroids. Nine developed pancreatitis after blunt trauma; seven had obstruction of the pancreaticobiliary drainage system. Two children developed pancreatitis in association with sepsis, and two had recurrent hereditary pancreatitis. Thirty of the 48 patients were managed nonoperatively while operations were required in 18. Seven had drainage of pancreatic pseudocysts, four had a pancreatectomy, and four underwent laparotomy with debridement and drainage of necrotic pancreas. Bilioenteric bypass procedures were performed to prevent recurrent pancreatitis in three patients; while duodenojenjunostomy sphincteroplasty and cholecystectomy were performed in one child each. Cure was achieved in 38 of 48 children treated for pancreatitis and its complications; each subsequently grew and developed normally. Hemorrhagic pancreatitis occurred in seven children, six of whom died. Seven deaths occurred, all in the medically treated group. Fifteen of the 18 children treated operatively did well in long-term follow-up. Although rare, pancreatitis is a serious cause of abdominal pain in childhood; almost half of the children will benefit from operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Advances in drug therapy for peptic ulcer disease

Recently, three new drug types have emerged to treat peptic ulceration. We compared the mechanism of action of omeprazole and somatostatin-14, both inhibitors of gastric acid, with that of tetraprenylacetone, a drug thought to be cytoprotective in the upper gut. Omeprazole and somatostatin-14 caused potent inhibition of meal-stimulated acid secretion in the dog (92% +/- 6% and 97% +/- 1%, respectively). On the other hand, tetraprenylacetone had no significant inhibitory effect on acid secretion (4% +/- 17%). In separate studies, tetraprenylacetone was shown to be a stimulant of gastric bicarbonate secretion in the rabbit, increasing bicarbonate secretion from a basal level of 0 to 86 +/- 28 pmol/2 h. Tetraprenylactone was also found to be a strong stimulant of canine pancreatic bicarbonate secretion. The ability of tetraprenylacetone to stimulate endogenous bicarbonate secretion may explain its ability to heal ulcers both experimentally and clinically.