Biomedical subjects

R Mårvik

Publications and source records attributed to R Mårvik.

13 recordsLinked to original sources

PubMed1996

[Transanal endoscopic microsurgery].

Transanal endoscopic microsurgery was introduced by Buess and co-workers in 1984 for transanal removal of tumours up to 20 cm above anus. In the present study, 18 transmural and two mucosal resections were performed for rectal adenomas (16) and early rectal cancer (4). Median operation time was 85 minutes (55-140 minutes) and the median postoperative stay in hospital was 3 days (1-5). All tumours were removed radically and in none was there tumour involvement of the resection margin. There were no serious complications. After a median observation time of 10 months (1-17 months) there have been no recurrences. Functional results are excellent; none of the patients have developed incontinence. It is concluded that transanal endoscopic microsurgery (TEM) is an adequate method for removal of benign rectal tumours and, in selected cases, early rectal cancer.

Adenoma↗

PubMed1995

Bioassay of gastrin using the isolated vascularly perfused rat stomach. A new, simplified and sensitive method.

Radioimmunoassays are sensitive and specific methods for measurement of the concentrations of regulatory peptides. However, aspects of physiological, pathophysiological and pharmacological research require knowledge about the biological activity which does not necessarily vary concomitantly with immunological activity. The present work describes a simplified bioassay for gastrin based on the gastric histamine releasing properties of this peptide, using an isolated vascularly perfused rat stomach preparation with a crystalline perfusate and a specific radioimmunoassay for histamine. The establishment of a dose-response curve is described, as well as the utilization of the bioassay on sera from patients with hypergastrinaemia. The method is sensitive for gastrin in the low (4 pmol L-1) picomolar range.

Anemia, Pernicious↗

PubMed1995

Neuroendocrine differentiation in colorectal carcinomas.

OBJECTIVE: To evaluate neuroendocrine differentiation in tumours from patients with colorectal carcinomas by immunostaining with antibodies against human chromogranin A (CgA) and neuron-specific enolase (NSE), and to correlate these finding with serum levels of CgA and pancreastatin-like immunoreactivity (PST-LI). We also investigated the degree of neuroendocrine differentiation found in colorectal carcinomas of different embryonic origins (hindgut and midgut). PATIENTS AND METHODS: The presence of CgA and NSE in tumours from 91 patients with colorectal carcinoma was investigated using immunohistochemistry; levels of CgA and PST-LI in sera from 55 of these patients were determined using radioimmunoassays. RESULTS: Immunostaining for CgA and NSE was found in 15 and 36% of tumours, respectively. One or both markers of neuroendocrine differentiation were demonstrated in 40% of the colorectal carcinomas. In patients who died during the study, 23 and 51% expressed CgA and NSE in their tumours, respectively, while the corresponding values in survivors were 11 and 27% (P = 0.14 and P = 0.025, respectively). The median survival time tended to be lower in patients with neuroendocrine differentiation of their tumours than in those without such differentiation (P = 0.1). The expression of NSE was significantly higher in colorectal carcinomas derived from the midgut than in those of hindgut origin. Elevated serum levels of CgA and PST-LI were found in 38 and 43% of the patients, respectively; 62% had elevated levels of one or both markers. Of the patients with elevated serum levels of CgA or PST-LI, 44% had positive immunohistochemistry for either NSE or CgA compared with 29% of those with normal serum levels of CgA and PST-LI (P = 0.27). Serum levels of CgA were increased in a significantly higher percentage of patients with colorectal carcinomas of midgut than of hindgut origin (63 and 28%, respectively, P = 0.03). Of patients with hindgut-derived carcinomas who died during the study, 64% had raised serum values of CgA compared with 19% of those who survived (P = 0.023). The corresponding figures for PST-LI elevation were 75 and 44%, respectively (P = 0.096). In the midgut group, no difference was demonstrated for these parameters between survivors and non-survivors. CONCLUSION: Neuroendocrine differentiation was demonstrated in 40% of the colorectal carcinomas investigated and was more frequent in midgut-derived carcinomas than in those of hindgut origin. We have shown for the first time that serum levels of CgA and PST-LI are elevated in patients with colorectal carcinomas. In accordance with previous studies, our data support the value of neuroendocrine differentiation as an indicator of poor prognosis; they also suggest a role for serum CgA and PST-LI as prognostic markers.

Biomarkers, Tumor↗

PubMed1994

The effect of tripotassium dicitrato bismuthate on the rat stomach.

BACKGROUND: Bismuth has been used as symptomatic treatment of dyspepsia for many years. It promotes healing of peptic ulcers and reduces their recurrence. The beneficial effect of bismuth on duodenal ulcer disease is thought to be due to an effect on Helicobacter pylori, although it has a rather weak bactericidal effect on H. pylori in vitro. Eradication of H. pylori in duodenal ulcer patients by a combination of bismuth, tetracycline and metronidazole has been reported to increase the density of somatostatin-producing D cells in the antrum. A reduced D cell density in the antral mucosa of duodenal ulcer patients could explain their exaggerated gastrin release. AIMS/METHODS: To test the possibility that bismuth could affect the neuroendocrine cells independently of the presence of H. pylori or not, we gave rats a diluted tripotassium dicitrato bismuthate solution by gastric gavage for 14 days. RESULTS: Tripotassium dicitrato bismuthate treatment did not affect maximal pentagastrin-stimulated acid secretion or histamine release in isolated rat stomachs or the density of argyrophil cells in the oxyntic and antral mucosa. However, it significantly reduced the duodenal concentration of gastrin and calcitonin gene-related peptide, and the density of G cells in the antrum and duodenum. CONCLUSION: The effect of tripotassium dicitrato bismuthate on the G cell may be of significance for its beneficial effect on duodenal ulcer disease.

Administration, Oral↗

PubMed1994

Gastrin regulates histidine decarboxylase activity and mRNA abundance in rat oxyntic mucosa.

Gastrin release histamine from the oxyntic mucosa, stimulates the enzymatic activity of histidine decarboxylase (HDC), increases HDC mRNA abundance, and has a trophic effect on the enterochromaffin-like (ECL) cell. In the present study, we examined the effect of exogenous gastrin on HDC activity and mRNA and the time scale of increase and decline of HDC activity and mRNA. Rats received intravenous infusion of gastrin-(1-17) in different doses or periods of time. Oxyntic mucosal HDC activity and mRNA abundance increased significantly with serum gastrin concentrations in the physiological range. The onset of response was rapid and maximal for both parameters after 2 h. Poststimulatory decrease was maximal 2 h after cessation of gastrin infusion. Those observations suggest that HDC enzymatic activity and mRNA abundance are important in meal-to-meal regulation of gastric secretion. Furthermore, HDC enzymatic activity and mRNA abundance varied in parallel, indicating that HDC mRNA abundance is important in the overall regulation of gastric mucosal HDC activity.

Animals↗

PubMed1994

Effect of cionin on histamine and acid secretion by the perfused rat stomach.

BACKGROUND: The protochordean octapeptide cionin is structurally a hybrid of mammalian cholecystokinin (CCK) and gastrin. An earlier study has shown that cionin in mammals stimulates gallbladder contraction and gastric somatostatin release, similarly to CCK-8. METHODS: In the present study we examined the effect of cionin on histamine release and acid secretion of the stomach, both effects being mediated by CCK-B/gastrin receptors. RESULTS: Cionin induced a concentration-dependent increase in histamine release and acid secretion in the isolated, vascularly perfused rat stomach, detectable at a concentration of 4 pM and reaching a maximum at a concentration of 512 pM. The CCK-B/gastrin receptor antagonist L 365,260 abolished the stimulating effect of cionin on both histamine release and acid secretion, whereas the CCK-A receptor antagonist L 364,718 only had a faint effect. CONCLUSION: Cionin is a potent and efficient stimulator of gastric histamine release and acid secretion interacting via a CCK-B receptor.

Amino Acid Sequence↗

PubMed1994

Complications during the introduction of laparoscopic cholecystectomy in Norway. A prospective multicentre study in seven hospitals.

OBJECTIVE: To assess the morbidity of laparoscopic cholecystectomy since its introduction in Norway in the Autumn of 1990. DESIGN: Postal collection of prospectively collected data. SETTING: Practices of 26 surgeons in 7 district and university hospitals. SUBJECTS: 527 patients who underwent laparoscopic cholecystectomy. INTERVENTIONS: 133 patients (25.5%) had endoscopic retrograde cholangiopancreatography before operation, and two had cholangiograms during operation; dissection was by electrocautery in 490 patients and by laser in 37. MAIN OUTCOME MEASURES: Morbidity, number converted to open operation, and number who required reoperation. RESULTS: There were no deaths and a total of 70 complications (13.3%), 8 of which were after laser dissection. There were 59 local complications (11.2%) and 11 general (2.1%); 12 patients (2.3%) required reoperation for bleeding (n = 5), biliary leak (n = 4), and incisional hernia (n = 3). One had a retained stone in the common duct. 42 were converted to open operation (8.0%), 11 because of complications (bleeding, n = 6; damage to the bile duct, n = 3; and bowel perforation, n = 2). Of the 28 patients with acute cholecystitis 5 (17.9%) had to be converted to open operations and 7 (25.0%) developed complications. 2 of these patients had bile duct injury. CONCLUSION: The morbidity during the introductory period of laparoscopic cholecystectomy in Norway is higher than that reported elsewhere, indicating that the risk of complications is increased during the learning period.

Bile Ducts↗

PubMed1993

Effect of nicotine on the enterochromaffin like cells of the oxyntic mucosa of the rat.

Smoking has an unfavourable effect on peptic ulcer disease. The pathophysiological mechanisms underlying this effect are not known. The enterochromaffin like (ECL) cell is the cellular source of histamine participating in the regulation of acid secretion. The ECL cell is under functional and trophic control of gastrin and the vagus nerves. Nicotine may affect acid secretion through vagal pathways. Furthermore, nicotine may also stimulate neuroendocrine cells. The present study examined if chronic nicotine administration could stimulate the function and growth of the ECL cell. Rats inhaled nicotine vapour at a concentration of approximately 6.2 mumol/m3, 20 hours/day, 5 days/week for 11 weeks. Steady state plasma nicotine concentration was 461.8 (137.5 (SD)) nmol/l. The ECL cell density, histamine content and histidine decarboxylase activity of the oxynitic mucosa were similar to the controls. We also examined the effect of acute nicotine stimulation on the acid output and histamine release from the totally isolated vascularly perfused rat stomach. Nicotine did not stimulate acid secretion or histamine release. Thus no evidence could be provided to support the hypothesis that nicotine exerts its negative effects on peptic ulcer disease by stimulating the ECL cell.

Administration, Inhalation↗

PubMed1993

Laparoscopic ultrasonography and treatment of hepatic cysts.

Laparoscopic unroofing of a solitary liver cyst was performed in two patients. To give an accurate picture of the cyst-liver anatomic relationship, laparoscopic ultrasonography (US) was performed with a 5 mHz rotating 90 degrees radial scanner. With this technique, an excellent resolution was obtained, and appropriate unroofing of the cysts could be performed. In both patients, additional information was gained that could not be obtained by percutaneous US or computerized tomography (CT).

Aged↗

PubMed1990

[Laser treatment of inoperable cancer of the esophagus and cardia].

The palliative effect of laser treatment for obstructing carcinomas of the oesophagus and gastric cardia was evaluated in 16 patients, between 59 and 81 years of age (median 73 years) and treated during the years 1986-89. All patients had severe dysphagia and none were able to eat solid food. They were judged inoperable because of advanced disease (9), reduced general condition, high age or concomitant disease (5). Two patients refused surgery. There was no procedure-related mortality. Complications were oesophageal perforation (1), bleeding (1) and development of fibrotic stricture (1). Ability to swallow was improved in all but one patient, and 13 became able to eat solid food. Seven patients needed repeated treatment 1-5 times at intervals of 3-10 weeks (median five weeks) between treatments. The results suggest that endoscopic laser treatment represents a good alternative in the palliative treatment of malignant obstructions in the oesophagus and gastric cardia.

Aged↗

PubMed1990

The benefit of colonoscopy.

In a prospective study involving 833 consecutive outpatient and open-access colonoscopies, attempts were made to characterize the benefit of colonoscopy in terms of both predicted and unpredicted findings and therapeutic procedures. The endoscopist therefore predicted the endoscopic findings before the endoscopy. The results were compared for the different indications for colonoscopy. The overall agreement between the predictions and the colonoscopic findings was 61%. Clinically significant abnormalities were found in about half the examinations. The most frequent abnormal findings were benign polyps (24%), inflammatory bowel disease (17%), and malignancy (5%). In about half the patients with a malignancy the indication for colonoscopy was rectal bleeding, and half of the malignancies were not predicted. The greatest benefit of colonoscopy was found in patients referred because of overt rectal bleeding or occult faecal blood, and abnormal barium enema or endoscopy findings. The importance of complete colonoscopy in connection with operation for colorectal carcinoma is emphasized.

Colonic Polyps↗

PubMed1983

Palatal myoclonus during sleep.

Standard polysomnographic recordings were carried out in three patients with verified diagnoses of palatal myoclonus (PM). Findings showed that PM continued during sleep; its frequency and amplitude varied consistently with different sleep stages. Gradual decrease in rate and amplitude, together with amplitude irregularities, occurred as sleep progressed from light to deep non rapid eye movement sleep. The most characteristic change was seen during rapid eye movement sleep. Here the PM occurred in the form of clusters of two to four high-amplitude movements at rather variable intervals.

Adult↗

PubMed1981

Cluster headache. The sweating pattern during spontaneous attacks.

Sweating in the forehead, on the eyelids, in the face and on the trunk was measured with the Evaporimeter during 31 spontaneous cluster headache attacks of varying severity in 18 patients. The evaporimeter measures evaporative water loss (sweating + transepidermal water loss) rapidly and accurately as g/m2/h. The patients themselves acted as controls. Sweating was also estimated in 25 healthy individuals at a temperature of 27 +/- 1 degree C, and a mean relative humidity of 19%. During eight severe attacks, sweating in the medial part of the forehead on the symptomatic side was invariably increased. In moderate attacks the increment was less pronounced and in the inter-cycle period, no definite increase was found. The cause of increased sweating during cluster headache attacks remains enigmatic.

Adolescent↗