Pseudomyxoma peritonei is a rare condition in which the abdominal cavity fills with thick mucoid material as a result of either a benign or malignant disease. We report the findings with gray-scale sonography and laparoscopy in a 74-year-old man with pseudomyxoma peritonei. After paracentesis and drainage of the ascites, sonography visualized hypoechoic nodules in the peritoneum at the surface of the liver and between bowel loops. Laparoscopy revealed mucoid material diffusely throughout the abdominal cavity. The diagnosis of pseudomyxoma peritonei was confirmed by cytologic examination of peritoneal fluid and histologic examination of laparoscopically obtained specimens.

Aged↗

PubMedDate not supplied

Interaction between endogenous opioids, cholinergic and adrenergic mechanisms during vagally-induced gastrin release in rats.

Endogenous opioids are present in neurons of the vagus and the intrinsic nervous system and they are colocalized with gastrin in antral G-cells. This raises the possibility that endogenous opioids modulate gastrin release. Stimulation of both cervical vagi (10V, 5Hz, 5ms) elicited an increase of arterial plasma gastrin levels at intragastric pH7 or pH2. The response at pH2 was 30% of that at luminal pH7. Atropine reduced vagally stimulated gastrin levels substantially. At luminal pH2 the small residual noncholinergic response was mediated neither by adrenergic mechanisms nor by endogenous opioids. At luminal pH 7 adrenergic blockade with phentolamine and propranolol reduced vagally stimulated gastrin by 60%. In the presence of atropine adrenergic blockade elicited only a small inhibitory effect suggesting that vagal activation of adrenergic mechanisms depends on atropine-sensitive cholinergic pathways. Blockade of opiate receptors by naloxone had no effect on vagal gastrin release, however, the noncholinergic gastrin response was reduced significantly by naloxone, suggesting that cholinergic mechanisms normally restrain activation of endogenous opioids during vagal stimulation. Naloxone had no effect on the noncholinergic, nonadrenergic stimulation of gastrin levels. These data suggest that endogenous opioids can contribute to vagal gastrin release provided the cholinergic restraint is blocked and adrenergic mechanisms stimulate endogenous opioids. In conclusion a major role of endogenous opioids in the regulation of vagal gastrin release can not be detected.

Animals↗

PubMedDate not supplied

Omega-conotoxin GVIA specifically blocks neuronal mechanisms in rat ileum.

Omega Conotoxin is a peptide venom of the marine snail Conus geographus which has been postulated as a neural specific calcium channel blocker in several systems. In the present study in rat ileum strips omega-conotoxin GVIA specifically blocked neuronal responses evoked by electrical field stimulation in a dose-dependent manner, but did not block responses induced by carbachol or direct depolarization with KCl. On the other hand the dyhydropyridine calcium channel blocker nitrendipine (10(-7) M) showed no specificity and blocked electrical field stimulation as well as carbachol- and KCl-induced contractions. This indicates that contractions of intestinal smooth muscle which can be blocked by dihydropyridine calcium channel blockers or Ca2+-free medium are not reduced by the neurotoxin omega-conotoxin. Omega-conotoxin caused even a little increase of the responses elicited by depolarisation with KCL. Omega-conotoxin blocked however neural mediated contractions which might suggest that it interacts with a distinct neuronal calcium channel and, in addition to tetrodotoxin, could provide a useful pharmacological tool to discriminate between muscular and neural sites of action of excitatory or inhibitory agents.

Animals↗

PubMedDate not supplied

Effect of vasoactive intestinal peptide, peptide histidine isoleucine and growth hormone-releasing factor-40 on bombesin-like immunoreactivity, somatostatin and gastrin release from the perfused rat stomach.

Bombesin-like immunoreactivity (BLI) has been demonstrated in neurons of the gastrointestinal tract and gastric BLI secretion can be demonstrated in response to the classical neurotransmitter acetylcholine. Since structurally related peptides VIP, PHI and GRF have to be considered as peptidergic neurotransmitters it was of interest to determine their effect on gastric BLI secretion. Additionally, somatostatin (SLI) and gastrin secretion was examined. The isolated stomach of overnight fasted rats was perfused with Krebs-Ringer buffer via the celiac artery and the effluent was collected via the portal vein. The gastric lumen was perfused with isotonic saline at pH7 or pH2. All four peptides were tested at a dose of 10(-11) M and 10(-8) M at both pH levels and in addition the effect of VIP and PHI was examined at 10(-14) M and 10(-12) M during luminal pH2. At luminal pH7 VIP and PHI stimulated SLI release at 10(-8) M but had no effect on BLI or gastrin secretion. rGRF and hpGRF were both ineffective on SLI and gastrin release while rGRF inhibited and hpGRF stimulated BLI secretion. This effect was not dose related. At luminal pH2 all four peptides stimulated BLI secretion. Stimulation by PHI was already observed at a dose of 10(-14) M while VIP elicited a stimulatory effect at 10(-12) M. PHI at the two lowest concentrations of 10(-14) and 10(-12) M elicited a stimulation of SLI and gastrin release while the same doses of VIP and the higher doses of all four peptides had no effect on SLI and gastrin secretion at an acidic intraluminal pH.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

Naturally occurring opioid peptides modulate H+-production by isolated rat parietal cells.

The rationale for the present study was to determine the effects of naturally occurring opioid peptides on H+-production by isolated rat parietal cells as indirectly measured by [14C]-aminopyrine uptake. In crude preparations (18 to 25% parietal cells) and in enriched (80 to 90%) parietal cell fractions stimulation by submaximal histamine- or dibutyryl cAMP-concentrations (10(-6)-10(-4) mol/l) was augmented by 20-30% in the presence of methionine-enkephalin (Met-Enk) and Met-Enk Arg6Phe7 (10(-7) to 10(-5) mol/l). This augmentation was blocked by the opiate receptor antagonist (-)naloxone (10(-6) mol/l) suggesting specificity of the action of Met-Enk and Met-Enk Arg6Phe7. At 10(-6) mol/l (-)naloxone did not exert nonspecific toxic effects. Yet, even in the absence of exogenous opioids, histamine-induced H+-production was inhibited by 3 X 10(-5) or 10(-4) mol/l (-)naloxone. Since similar inhibition occurred with (+)naloxone, an inactive stereoisomer which does not interact with opiate receptors, effects of (-)naloxone at concentrations above 10(-5) mol/l must be considered nonspecific. We conclude that Met-Enk and Met-Enk Arg6Phe7 have no effect on basal, but augment stimulated H+-production by a direct effect on the parietal cells. At nontoxic concentrations (-)naloxone antagonizes this augmentation indicating that it is mediated by specific opiate receptors on the parietal cells.

Aminopyrine↗

PubMedDate not supplied

Endoscopic ultrasonography in esophageal diseases.

Endoscopic ultrasonography (EUS) was performed prospectively in 38 patients with various esophageal disorders. Twenty-four had a histologically proven carcinoma and EUS was done to assess its ability in preoperative staging. In 9 of 24 patients (37.5%), tumor stenosis could be passed with the endoscope and EUS preoperative findings regarding tumor extension and the presence of enlarged periesophageal lymph nodes were confirmed in those operated on (n = 4). In five patients with achalasia, a periesophageal tumor was reliably excluded by EUS. In one of four patients with Barrett's esophagus, EUS demonstrated a small (less than 1 cm) carcinoma that could not be visualized with any conventional technique. For differentiation of cancer recurrence after operation from periesophageal scar tissue EUS-guided transmural biopsies are needed. Our experience shows that at the present time EUS is the most reliable method to demonstrate small (less than or equal to 1 cm) intra- and extramural esophageal lesions and that it should therefore be applied early in the work-up of patients with dysphagia.

Aged↗

PubMedDate not supplied

Endoscopic ultrasonography in the evaluation of colon and rectal disease.

Endosonography of the colon has until recently been limited to examination of the rectum. Rigid and flexible instruments are currently available which allow for detailed images of the rectal wall. Comparative studies suggest that endosonography may be more accurate than computed tomography in the preoperative staging of rectal carcinoma. Recently, an ultrasound colonoscope has been developed which allows for visual examination, biopsy, and endosonography throughout the colon. Experience with this technique is limited and its role in the evaluation of colonic disease has not yet been determined. Further comparative trials are needed to more fully define the role of endosonography in the diagnosis of colorectal disease.

Colon↗

PubMedDate not supplied

Colonic endoscopic ultrasonography: first results of a new technique.

Explore the source record for details and available documents.

Adenoma↗

PubMedDate not supplied

The cystic artery: borderline between internal medicine and surgery?

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Ampulla of Vater↗

PubMedDate not supplied

Percutaneous cholangioscopic or transpapillary insertion of self-expanding biliary metal stents.

Fifty-two self-expanding metal stents were implanted in 39 patients with malignant (35 patients) or benign (4 patients) biliary stenoses. The stents were inserted and properly released by means of a 7 or 9 French gauge delivery catheter via the percutaneous (20 patients) or transpapillary (19 patients) route. In all cases the endoprostheses expanded to a diameter of 7 to 10 mm and achieved complete biliary tract drainage. Jaundice disappeared in 36 of the 39 patients. No early complication was observed. After a median follow-up of 121 days (range, 30 to 422 days), 19 of 36 patients are still alive and 17 died of non-procedure-related causes. Biliary re-obstruction occurred in five patients due to tumor overgrowth above or below the prosthesis (four patients) or bile encrustation (one patient). In patients with malignant stenoses, the probability of stent patency is 78% after 200 days. We conclude that large-bore metal stents are safe, effective, and provide better long-term patency than conventional endoprostheses.

Adenoma, Bile Duct↗

PubMedDate not supplied

Endoscopic ultrasound in pancreatic tumor diagnosis.

In a prospective study from 1988 to 1990, 132 patients with suspected pancreatic tumor were examined with endoscopic ultrasound (EUS), transabdominal ultrasound (US), computed tomography (CT), and ERCP. The final diagnosis of 102 pancreatic tumors of different origin (76 malignant and 26 inflammatory tumors) and the exclusion of a pancreatic tumor in 30 patients was made by operation (N = 47), puncture (N = 36), autopsy (N = 3), or follow-up of a mean of 51 weeks (N = 46). Sensitivity and specificity in pancreatic tumor diagnosis were significantly higher for EUS (99% and 100%) than for US (67%/40%) and CT (77%/53%) and equal to ERCP (sensitivity 90%). This was even more obvious in small pancreatic tumors of 3 cm and less. However, as with the other imaging procedures, EUS was not able to differentiate reliably malignant from inflammatory pancreatic masses (accuracy 76% for malignancy and 46% for focal inflammation). From analysis of the endosonographic pattern of pancreatic tumors, no consistent morphologic features were identified which could have been specifically attributed to malignant or inflammatory masses. Our results show that EUS is superior to US and CT and equal to ERCP in pancreatic tumor diagnosis. In contrast to the indirect evidence obtained by ERCP, EUS provides direct visualization of tumor size and shape in almost all patients examined. Thus, EUS should be considered early in the evaluation of patients with suspected pancreatic tumors.

Adult↗