Search PubMed⌕ Search

Biomedical subjects

M Classen

Publications and source records attributed to M Classen.

At least 145 records · Page 8Linked to original sources
PubMed1991

[Endoscopic papillotomy (sphincterotomy) in the 1990-s].

This review summarizes the past history and presence of endoscopic papillotomy (EPT, sphincterotomy) in the treatment of biliary and pancreatic tract diseases. The indications of the different techniques used, and the comparison of the effectiveness of EPT with that of the traditional surgical treatment is also discussed. Based on the results, EPT is an up-to-date technique with good effectiveness, low risk for patients and widening indication range. EPT in the future, will play a determining role in the effective treatment of biliary and pancreatic tract diseases.

Ampulla of Vater↗
PubMed1991

Neuropeptide Y and food intake in fasted rats: effect of naloxone and site of action.

Central administration of neuropeptide Y (NPY) induces food intake in freely feeding animals and this effect is mediated by hypothalamic sites. Little is known, however, about the effect of NPY on food intake and site of action in food-deprived animals. To examine this further, 24-h fasted rats received injections of saline or NPY into the lateral cerebral ventricle (10 micrograms/10 microliters; n = 8) or into the lateral (LH) or ventromedial hypothalamus (VMH) (1 microgram/0.5 microliters; n = 44). In addition, intracerebroventricular (i.c.v.) injections of NPY were carried out with or without i.c.v. naloxone (25 micrograms), a specific opioid receptor antagonist. During the first 40 min food intake was not different with or without NPY. After 60 and 120 min, food intake was 5.9 +/- 0.4 g and 8.3 +/- 0.6 g with i.c.v. saline which was significantly augmented by i.c.v. NPY to 8.7 +/- 0.9 g and 14.4 +/- 1.5 g, respectively (P less than 0.05). This increase in food consumption was due to a prolongation of feeding time. The opioid receptor antagonist naloxone significantly augmented latency to feed, both in the absence and presence of NPY (8.0 vs 1.7 min or 14.7 vs 2.8 min, respectively) and abolished the NPY-induced increase in food intake. Following intrahypothalamic injection of NPY, an increase in food intake (greater than 20%) was observed in 50% of the histologically identified LH and VMH sites, but only in 15% of the injection sites outside the LH/VMH.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

A major fraction of human intraepithelial lymphocytes simultaneously expresses the gamma/delta T cell receptor, the CD8 accessory molecule and preferentially uses the V delta 1 gene segment.

The frequency of T cell receptor (TcR) type and the variable gene segment expression in human intraepithelial lymphocytes (IEL) from the large intestinal mucosa were studied by flow cytometry and immunohistochemistry, and compared to those in peripheral blood lymphocytes (PBL) - or lamina propria lymphocytes (LPL). Employing anti-gamma/delta TcR and anti-alpha/beta TcR monoclonal antibodies (mAb), flow cytometric analysis revealed that a large fraction of IEL (37%) are gamma/delta T cells, whereas within LPL and PBL gamma/delta T cells comprise a minor population (4.6% and 3.8% respectively). At these sites the number of gamma/delta T cells labeled with anti-CD8 mAb were 58.3% (IEL), 43.3% (LPL) and 24.4% (PBL). In situ staining of serial sections of large intestine confirmed these results. Hence, these data suggest a selective accumulation of CD8+ gamma/delta T cells in the human epithelium of the large intestine. Furthermore, analysis of gamma/delta TcR bearing IEL+ disclosed a marked preponderance of cells using the V delta 1 gene segment, whereas gamma/delta TcR+ PBL preferentially express V delta 2. Strikingly, the majority of these V delta 1+ IEL bear the CD8 molecule on their surface. These results are taken as evidence for a selective localization of V delta 1+ CD8+ gamma/delta T cells in the epithelium of the large intestine.

Adult↗
PubMed1991

The effect of glucose and insulin on vagally induced gastrin, bombesin-like immunoreactivity and somatostatin secretion from the perfused rat stomach.

Previous studies in the isolated perfused rat stomach have shown that elevated glucose and insulin concentrations modulate BLI and somatostatin release during arterially administered peptidergic stimuli. In the present study the effect of elevated levels of glucose or insulin was examined on vagally induced changes of gastrin, somatostatin and BLI secretion. The lumen of the stomach was perfused with saline pH 7 or pH 2. Vagal stimulation (5 Hz, 1 msec, 10V) increased gastrin and BLI secretion and inhibited somatostatin release. The increase of the perfusate glucose concentration from 100 mg/dl to 150 or 300 mg/dl or the addition of insulin (100 microU/ml) augmented vagally stimulated gastrin release at luminal pH 7 but not pH2. Vagally induced inhibition of somatostatin was attenuated by both concentrations of glucose at either luminal pH while insulin had no effect. BLI secretion was affected neither by elevated glucose nor by insulin. On the other hand, the noncholinergic component of vagally induced BLI secretion in the presence of atropine was augmented by insulin. These data demonstrate that glucose and insulin can modulate vagally activated gastric neuroendocrine functions which could be of relevance during the ingestion of carbohydrate containing meals.

Animals↗
PubMed1991

Gastric fundus impression caused by splenic vessels: detection by endoscopic ultrasound.

When a submucosal impression of the stomach fundus is seen during upper GI endoscopy, a true submucosal tumor can reliably be differentiated from an extragastric impression by endoscopic ultrasound (EUS). We report on 15 patients in whom EUS identified splenic vessels near the splenic hilum causing an impression of the posterior wall of the gastric fundus. Neither by EUS nor conventional ultrasound, computed tomography or clinical follow-up, was a tumor in the stomach or upper abdomen that could have been the cause of the gastric wall impression, identified. Two of the 15 patients had portal hypertension with multiple intra-/paramural venous collateral vessels. Twenty patients examined for other reasons and 10 patients with portal hypertension but without fundic impressions, served as controls: In these cases the splenic vessels were shown by EUS to follow a course more distant to the gastric wall. Thus, normal vascular structures should be included in the differential diagnosis of gastric fundus impression detected by endoscopy.

Diagnosis, Differential↗
PubMed1991

The quality of gastroenterological reports based on free text dictation: an evaluation in endoscopy and ultrasonography.

The majority of physicians consider the use of free dictation for medical reports to be essential in many domains. One of the main criticisms of structured data entry is the possible lack of flexibility and completeness. Electronic documentation systems exist for endoscopy and ultrasonography examinations which are based on structured input as well as on free dictation. Endoscopy and ultrasonography reports based on free dictation were evaluated for omissive errors. The data evaluated was drawn from a database of 18,239 gastroscopy and 3,340 colonoscopy reports dictated by 28 physicians over 74 months, and 18,834 ultrasonography reports dictated by 37 physicians over 42 months. The error rates varied from 0% to 41.8% depending upon the particular feature and the particular examination, but were usually below 15%. The results were independent of the experience of the examiner. This study provides baseline measurements of omissive error rates for selected findings in gastrointestinal endoscopy and abdominal ultrasonography which can be used as standards for the development and evaluation of systems for collection of clinical data.

Database Management Systems↗
PubMed1991

An unusual case of active tuberculosis of the oesophagus in an adult.

A case is reported of a 56-year-old woman of Libyan origin presenting with dysphagia, retrosternal pain and weight loss. Oesophago-gastroduodenoscopy revealed an ulcerated tumor in the upper oesophagus strongly suggesting a malignancy. A positive Mendel-Mantoux test along with histological evidence of epitheloid cell granulomas and clinical findings consistent with pulmonary and lymph node tuberculosis led to the presumptive diagnosis of oesophageal tuberculosis. The diagnosis was later confirmed by positive bacteriological cultures of oesophageal biopsies and gastric washings. It is very unusual for dysphagia to be the presenting symptom of active adult tuberculosis. Oesophageal tuberculosis is extremely rare and must be distinguished predominantly from oesophageal carcinoma.

Deglutition Disorders↗
PubMed1991

A new pull-through trocar technique for percutaneous operative endoscopy.

A pull-through trocar is described which establishes a percutaneous access to the stomach and may immediately be used for endoscopy. The trocar is placed in a similar fashion to PEG probes. The technique was evaluated in animals. Using rigid endoscopes and instruments introduced through the trocar operative manipulations of the gastric wall were carried out. There were no severe complications. The new method extends the scope of percutaneous therapeutic endoscopy (minimal invasive surgery) by permitting direct access to the interior of the stomach.

Animals↗
PubMed1991

Fish oil reduces ethanol-induced damage of the duodenal mucosa in humans.

Eight healthy volunteers were studied before and after 3 weeks of dietary supplementation with fish oil (10.5 g day-1, 18% (1.9 g) eicosapentaenoic acid). Duodenal mucosal lesions were induced by instillation of 40 ml ethanol (40%). Mean endoscopic lesion score was lower after fish oil treatment (1.62 +/- 0.32; mean +/- SEM) than before (3.25 +/- 0.31; P less than 0.01). Histologic lesion score fell from 22.75 +/- 1.98 before treatment to 13.50 +/- 1.51 after fish oil (P less than 0.01). Basal and pentagastrin-stimulated gastric acid output remained unaffected. Release of prostaglandin E2, 6-keto-prostaglandin F1 alpha, and thromboxane B2 from biopsy specimens of the duodenal mucosa in vitro was not significantly altered after fish oil ingestion. In the same in vitro system calcium ionophore A23187-induced release of total leukotriene C (LTC) increased from 10.6 +/- 1.5 ng g-1 mucosa 20 min before treatment to 30.4 +/- 3.2 ng after fish oil. High pressure liquid chromatography analysis showed that this increase was partly due to formation of LTC5 as after fish oil 28% of total LTC were identified as LTC5 whereas 72% were LTC4. We conclude that in humans fish oil reduces ethanol-induced damage of the duodenal mucosa without inhibiting gastric acid secretion or stimulating prostaglandin formation. It remains to be clarified if the changes in leukotriene formation are relevant for the mucosaprotective fish oil effect.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

GLP-1-(7-36) amide, -(1-37), and -(1-36) amide: potent cAMP-dependent stimuli of rat parietal cell function.

We investigated the effect of glucagon-like peptide 1 (GLP-1)-(7-36) amide and its molecular variants GLP-1-(1-37) and GLP-1-(1-36) amide on enzymatically dispersed enriched rat parietal cells using [14C]aminopyrine accumulation as a measure of H+ production. GLP-1-(7-36) amide was 100 times more potent than GLP-1-(1-37) and GLP-1-(1-36) amide in stimulating [14C]aminopyrine accumulation. At their maximally effective concentrations, GLP-1-(7-36) amide (10(-8) M), GLP-1-(1-37) (10(-6) M), and GLP-1-(1-36) amide (10(-6) M) reached 80-90% of the response to 10(-4) M histamine. However, the peptides were 100-10,000 times more potent than histamine, which induced maximal [14C]aminopyrine accumulation at 10(-4) M. Stimulation by GLP-1 was dependent on the presence of a phosphodiesterase inhibitor and was not altered by pertussis toxin. Ranitidine failed to affect the response to the GLP-1 variants. Stimulation of H+ production by GLP-1 was accompanied by an increase in the formation of adenosine 3',5'-cyclic monophosphate (cAMP) but not by changes in phosphoinositol breakdown. In stimulating [14C]aminopyrine accumulation, the GLP-1 variants acted additively to threshold but not to maximal concentrations of histamine, suggesting that histamine and GLP-1 activate the same cAMP pool. In contrast, in anesthetized rats GLP-1-(7-36) amide (10-500 ng.kg-1.h-1) had no effect on basal and pentagastrin-stimulated acid secretion in vivo. We conclude that GLP-1 exerts a direct stimulatory effect on rat parietal cells. This potent effect is mediated by cAMP and is independent of H2 receptors. In vivo direct stimulation by GLP-1 of the parietal cells might be counterbalanced by indirect inhibitory mechanisms that are excluded in the in vitro cell system.

1-Methyl-3-isobutylxanthine↗
PubMed1991

Modulatory effect of insulin on rat small intestinal motility and peptide release in vitro.

Intact segments of rat ileum were stimulated in vitro by either electrical field stimulation (EFS) or cholinergic stimulation with carbachol, in the presence of absence of varying insulin concentrations (50, 100 and 200 microU/ml), and the contraction in the longitudinal axis was recorded. Insulin had no significant influence on the carbachol contractile dose-response curve nor did it affect the cholinergically mediated 'on-contraction' at onset of the electrical stimulus. The 'off-contraction' occurring at cessation of the electrical stimulus was partly mediated by a cholinergic and partly by a noncholinergic and nonadrenergic mechanism, and decreased over time with repeated stimulation. This decay with time was significantly attenuated by insulin. In the presence of insulin, release of bombesin-like immunoreactivity induced by carbachol or EFS significantly increased. On the other hand, the release of somatostatin-like immunoreactivity was suppressed by 50-70% in the presence of insulin. These results demonstrate that in vitro insulin can modify both the motility responses of isolated segments of rat ileum and the neuropeptide release from such segments.

Animals↗
PubMed1991

Substitution of factor XIII: a therapeutic approach to ulcerative colitis.

Three patients with ulcerative colitis in the active stage demonstrated reduced levels of F XIII activity and F XIII subunit A (61 and 80.3%, respectively). Because of the lack of clinical improvement during conservative therapy, the patients were treated additionally with F XIII concentrate (Fibrogammin HS, Behring, FRG) for 10 days. The substitution resulted in an increase in F XIII activity (144.3%) and F XIII subunit A (238%) as well as in a marked improvement in symptoms.

Adrenal Cortex Hormones↗
PubMed1991

Effect of motilin on gastric emptying in patients with diabetic gastroparesis.

OBJECTIVES: Because disturbances of gastric emptying are a serious complication in insulin-dependent diabetic subjects with regard to the maintenance of good metabolic control, we wanted to assess the effectiveness of motilin as a potential treatment for gastric emptying disturbances. RESEARCH DESIGN AND METHODS: The intestinal hormone motilin has been shown to accelerate gastric emptying in healthy subjects. Therefore, we examined the effect of intravenous motilin on gastric emptying of a 99mTc colloid-labeled semisolid test meal in 9 insulin-dependent diabetic patients with diabetic gastroparesis. All patients had a significantly delayed gastric emptying rate compared with a group of 11 healthy control subjects. RESULTS: During the infusion of motilin, gastric emptying was accelerated, and it was no longer significantly different from control values. CONCLUSIONS: These data demonstrate that motilin and related compounds such as erythromycin derivatives could be useful for the treatment of disturbed gastric emptying in diabetic subjects.

Adult↗