P. Vezzadini

Interdigestive gastroduodenal motility and serum motilin levels in patients with idiopathic delay in gastric emptying

The interdigestive gastroduodenal motor activity and serum motilin levels were studied in 22 dyspeptic patients with markedly delayed gastric emptying not due to diseases known to impair gastroduodenal motility and in 7 control subjects with normal gastric emptying. Motor activity was recorded using a manometric probe positioned in the gastric antrum and in the proximal duodenum, and blood samples for radioimmunoassay of motilin were taken every 15 min during the recording period. The control subjects showed gastroduodenal activity fronts of the migrating motor complex associated with motilin peaks. Almost all patients with delayed gastric emptying showed no activity fronts in the stomach, and only half of them showed activity fronts starting in the duodenum. In these patients a significant reduction in the number of motilin peaks and in the integrated motilin output during the identified peaks was also observed. The results of this study indicate that most dyspeptic patients with idiopathic delay in gastric emptying may also have an alteration in interdigestive gastroduodenal motility, mainly characterized by a lack of gastric activity fronts, associated with an impaired motilin release.

Chromogranin A in gastric neuroendocrine tumours: an immunohistochemical and biochemical study with region-specific antibodies

The aim of the present study was to investigate ECLomas and enterochromaffin-like (ECL) cell hyperplasia in gastric human mucosa regarding the immunohistochemical expression of chromogranin A (CgA) epitopes and to measure the same CgA epitopes in plasma samples. Eight gastric biopsies from ECLomas, seven of type I and one of type III, and biopsies from one patient showing only ECL cell hyperplasia were included in the study. Our results revealed a varying expression of region-specific CgA epitopes in the ECLomas regarding both the frequency of immunoreactive cells and intensity of immunoreactivity. CgA284–301 (pancreastatin) was not revealed in any neoplasm, whereas CgA361–372 (catestatin) was expressed in all ECLomas. However, the number of immunoreactive cells to vesicular monoamino transporter 2 (VMAT 2) or the commercial monoclonal CgA (CgA250–284) antibodies were generally higher. The plasma concentrations of the region-specific CgA radioimmunoassays differed considerably, with highest concentrations of CgA1–17 and CgA116–130 epitopes and the lowest with the CgA17–37, CgA63–76, CgA238–247 and CgA441–424 epitopes. No relationship was found between tissue expression and plasma concentration of CgA epitopes. In conclusion, this study shows that VMAT 2 and the commercial CgA antibodies seem more useful for histopathological diagnosis of ECLomas than the antibodies to the other CgA regions.

Effect of hypothyroidism on vasoactive intestinal polypeptide-immunoreactive neurons in forebrain-neurohypophysial nuclei of the rat brain

We have recently reported that hypothyroidism increases immunoreactive (IR)-vasoactive intestinal polypeptide (VIP) and VIP mRNA content in both parvocellular and magnocellular neurons of the rat, hypothalamic paraventricular nucleus (PVN). As VIP can stimulate vasopressin (AVP) secretion, we conducted an anatomical investigation to determine whether VIP-containing neurons in other regions of the brain that are involved with homeostatic mechanisms of water and salt conservation are also affected by hypothyroidism. The distribution and intensity of VIP immunostaining in neurons and fibers of the magnocellular-neurohypophysial system, including the hypothalamic PVN, supraoptic nucleus (SON) and accessory magnocellular cell groups, circumventricular subfornical organ (SFO), preoptic and anterior hypothalamus, midline thalamus, subthalamic zona incerta and posterior septal nuclei were studied using a highly sensitive immunocytochemical technique and unbiased neuronal counting methods, based on the optical dissector principle. Hypothyroidism increased the intensity of VIP immunostaining and/or the number/section, percentage and numerical density of IR-VIP neurons in the PVN, SON, nucleus circularis, periventricular preoptic nucleus of the hypothalamus and SFO. In addition, IR-VIP perikarya and/or fibers in the hypothalamic medial preoptic area and anterior periventricular nucleus, nucleus reuniens of the thalamus and dorsal fornix-triangular septal nucleus complex were also apparent in the hypothyroid animals while no immunostaining was seen in these areas in control animals. No quantitative and/or qualitative modifications in IR-VIP neurons and fibers were noted in the anterior hypothalamic area, suprachiasmatic nucleus, thalamic paraventricular nucles an subthalamic zona incerta between hypothyroid and control animals. These findings suggest an inverse relationship between thyroid hormone and VIP content and/or distribution of IR-VIP neurons in specific forebrain regions involved in the control of AVP release, extracellular fluid volume, thirst, blood pressure and anterior pituitary secretion. This raises the possibility that changes in fluid homeostasis and cardiovascular function occurring in hypothyroidism may be mediated, at least in part, by VIP-producing neurons in diverse regions of the brain.

Vasoactive Intestinal Polypeptide (VIP) Secretion and Refractory Diarrhea in Patients with AIDS or AIDS-Related Complex (ARC)

Elevated plasma levels of vasoactive intestinal polypeptide (VIP) (as assessed by a radio-immunoassay), were found in 7/11 patients with AIDS or AIDS-related Complex (ARC), evaluated because of prolonged intractable diarrhea with either an infectious (6 cases) or a non-infectious (5 cases) etiology. Six subjects have been treated with the somatostatin analogue octreotide, which gave both a favourable clinical response and a significant reduction in plasma VIP concentrations. Evaluation of plasma VIP levels may provide a pathophysiological basis for explaining the efficacy of octreotide therapy in HIV-infected patients suffering from both infectious and non-infectious refractory diarrhea.

Life-threatening gastrointestinal hemorrhage with omeprazole.

To The Editor: Omeprazole is a highly potent and long-lasting antisecretory agent which acts by inhibiting (H +, K§ and is believed to be the proton pump inhibitor of the parietal cell (1). Here we report two cases in which oral omeprazole administration resulted in stopping severe gastrointestinal bleeding from duodenal ulcer in Zollinger-Ellison patients resistant to high-dose H2 antagonists. A 55-year-old man with Zollinger-Ellison syndrome was admitted to our Medical Department on November 1984 because of a large (2-cm-diameter) and penetrating ulcer of the anterior wall of duodenal bulb unresponsive to treatment. After a oneweek regimen with ranitidine 500 mg intravenous and pirenzepine 40 mg intravenous daily, suddenly the patient was found with hemorrhagic shock and massive melena. Adequate blood replacement was planned, and a large amount of gastric juice mixed with blood (pH 1.6) was removed from the stomach through a nasogastric tube. A single dose of 90 mg omeprazole was then given orally, and 2 hr later the endoscopic examination showed a blood cloth covering the ulcer and no blood mixed with the gastric juice (pH 5.5). Complete healing of the ulcer was achieved following a three-week treatment (90 mg daily for one week and 60 mg daily for two weeks). Subsequently the patient underwent surgery for pancreatic tumor excision, but the operation was not radical. He did not have ulcer relapse or rebleeding and, at present, he is in good health and gastric hypersecretion and symptoms are controlled with 20 mg of omeprazole given orally every other day. The second patient, a 22-year-old man with Zollinger-Ellison syndrome associated with MEA type I, was recently admitted to our Surgical Department for severe upper gastrointestinal bleeding (Hb 5.6 g/100 ml, hematocrit 17%) due to an extremely large and penetrating ulcer of duodenal bulb. One month earlier, he underwent a nonradical operation of body-tail pancreatectomy and splenectomy with exeresis of three endocrine tumoral nodules. Five days later the patient was reoperated to drain a collection of pancreatic juice in the left subphrenic space. Treatment with intravenous somatostatin and ranitidine was started for a residual pancreatic fistula and the persistence of severe gastrointestinal symptoms (epigastric pain. vomiting, diarrhea). At the admission, massive acid hypersecretion with gastric stasis and metabolic alkalosis was observed. The basal acid output 2 hr following intravenous administration of 100 mg ranitidine was 25.2 mmol/ hr. The patients condition was considered lifethreatening; therefore omeprazole was orally administered as an emergency measure at a once daily dose of 100 mg for four days. 80 mg for 10 days, and 60 mg subsequently. The basal acid output was reduced to 0.1 mmol/hr during the 12 hr following the first administration and remained less than 3.7 mmol/hr before the next dose in several controls during treatment. No blood could be aspirated by the stomach tube. The patient improved markedly and. at the present time, five months after the beginning of the treatment, the peptic ulcer is completely healed and the acid hypersecretion and the clinical symptoms are controlled with a 60-mg once daily dose of omeprazole. In these two critically ill patients, in whom massive acid hypersecretion and bleeding could not be controlled by high-dose H2 antagonists, omeprazole treatment was a valid alternative to total gastrectomy, which, in these emergency conditions, is associated with a high mortality. Several studies have shown that oral omeprazole is effective and well tolerated in the long-term management of ZollingerEllison syndrome (2) and in the short-term treatment of common peptic ulcer (3), but no data are available on the treatment of acute upper gastrointestinal bleeding. Preparations of omeprazole for intravenous injection and studies on the more common acute upper gastrointestinal bleeding episodeS from other causes are needed and awaited with interest.

Influence of Gastric Acid Secretion on Interdigestive Gastric Motor Activity and Serum Motilin in the Elderly

The purpose of this study is to investigate the influence of gastric secretion on the interdigestive gastric motor activity and related serum motilin variations in elderly subjects. The study was carried out on two groups of elderly subjects: one with achlorhydria or marked hypochlorhydria due to chronic atrophic gastritis and the other with normal acid secretion. A group of nonelderly subjects with normal acid secretion was also examined as control. Gastric motility was studied manometrically and serum motilin was measured by radioimmunoassay on blood samples taken every 15 min during the entire motor recording period of 200-300 min. Both groups of elderly subjects showed (1) alterations in interdigestive gastric motility and (2) serum motilin which was steadily high without the normal cyclic fluctuations. These studies suggest that the alterations in gastric motor activity and serum motilin in aged subjects are not related to the acid secretory capacity of the stomach. Other factors, such as alterations in the neurohormonal control system of gut motility, should be considered in the genesis of these age-related disorders.

The use of crypt suspensions for endocrine cell quantification

We have recently described a new approach for the quantification of intestinal endocrine cells, based on their direct counting in single crypts and villi microdissected from small pieces of immunostained intestinal mucosa (Ferri et al., 1982). Since the method is limited in practice by the time-consuming procedure of microdissection, we describe here a technical modification, which makes it possible to obtain suspensions of intact, whole colonic crypts virtually ready for immunostaining and quantification. Samples of full-thickness human colon (at least 1 x 2 cm) are injected in the submucosa with a 5mmol/1 solution of sodium EDTA in Krebs-Henseleit bicarbonate-saline, in a quantity sufficient to obtain complete flattening of the mucosal folds (10-50 ml) and immersed in 20-50 ml of the same solution (enough to cover the tissue) (Dupont et al., 1980; Ferri et al., 1983). After 60-90 min incubation, with occasional agitation, samples are vigorously shaken by hand in the incubation fluid (20-30 s) and an epithelial pellet is obtained from the incubation fluid by centrifugation (at 150g for 10 min). The supernatant is poured out and replaced with freshly-prepared 0.4% p-benzoquinone solution in phosphate-buffered saline (PBS), pH 7.2-7.3 (Bishop et aI., 1978), and the epithelium is resuspended in the fixative by inverting the tubes several times, immediately and during the course of fixation (1 h). Crypt preparations are washed with PBS (if tubes are left vertical for a few minutes, centrifugation is not usually required) and stored in PBS containing 0.02% sodium azide. The suspensions are dehydrated through graded alcohols, cleared with xylene, and rehydrated as described previously by Ferri et al. (1982). They are immunostained by an immunofluorescence procedure (Coons et aI., 1955) in conical tubes, using small amounts of primary and F1TC-conjugated secondary antibodies (each overnight) and by filling the tubes with PBS for the washings. Immunostained crypts are then layered on slides in a drop of PBS-glycerine (3:2 v/v). Over forty samples of bowel have been treated by this technique in our laboratories. The accuracy of the epithelial removal can be easily checked by counting, under a dissecting microscope, the number of crypts remaining in the tissue sample (Fig. 1). The method proved highly reproducible since 2% of the crypts remained in the mucosa in virtually all samples. Epithelial preparations are mainly composed of well-preserved whole crypts (Fig. 3), in which endocrine cells are easily demonstrated (Fig. 2). In order to confirm the suitability of crypt suspensions for endocrine cell quantification,

Secretin-stimulated trypsin-like immunoreactivity in alcoholics.

Serum trypsin-like immunoreactivity (TLI) was studied in alcoholics without evidence of pancreatic disease and in controls. Basal values were 29 +/- 4.6 microgram/l (mean +/- S.E.M) in alcoholics and 23 +/- 4.4 microgram/l in controls (p not significant). The injection of secretin was followed by a significant increase of serum TLI in both groups; the integrated trypsin output (ITO) in the first hour after secretin administration was 947 +/- 403 (mean +/- S.E.M.) in alcoholics and 76 +/- 15 in controls (p less than 0.05). In 9 (75%) of the alcoholics tested, ITO was higher than the highest ITO of controls. The increase of serum TLI after injection of secretin is probably due to secretion and/or regurgitation of trypsinogen into the bloodstream when the pancreas is stimulated with intravenous secretin. In the light of experimental studies on chronic ethanol intoxication in animals, the increased ITO observed in alcoholics may suggest obstruction to pancreatic secretory flow in spite of the absence of any clinical sign of pancreatic disease.

Gastrinoma of the stomach: a case report.

Gastrinomas of the stomach are extremely rare endocrine tumors producing Zollinger-Ellison syndrome. We report here the case of a patient with gastrinoma of the stomach who presented regional and hepatic metastases at the time of diagnosis. The endocrine tumor was discovered incidentally 8 yr after the onset of symptoms related to peptic ulcer, which responded to medical treatment with a proton pump inhibitor. Surgery did not cure the patient, as demonstrated by provocative tests showing serum gastrin responses indicative of residual disease. A long-term treatment with the somatostatin analog lanreotide induced a biochemical response and was associated with a substantially stable disease.

Effect of Secretin on Serum Trypsin-Like Immunoreactivity in Alcoholics

Serum trypsin-like immunoreactivity (TLI) was studied with a newly developed radioimmunoassay in human subjects. The intravenous administration of secretin was followed by an evident increase of serum TLI significantly greater in alcoholics as compared to controls.