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Thomas Frieling

Publications and source records attributed to Thomas Frieling.

7 recordsLinked to original sources
PubMed2006

Hydrogen sulfide is a novel prosecretory neuromodulator in the Guinea-pig and human colon.

BACKGROUND & AIMS: Hydrogen sulfide (H(2)S) has been suggested as a novel gasomediator. We explored its unknown neuromodulatory role in human and guinea-pig colon. METHODS: We used immunohistochemistry to detect H(2)S-producing enzymes cystathionine gamma-lyase (CSE) and cystathionine beta-synthase (CBS) in enteric neurons, Ussing chambers to measure mucosal ion secretion, and neuroimaging with voltage- and Ca(++)-sensitive dyes to record H(2)S effects on guinea-pig and human enteric neurons. RESULTS: More than 90% of guinea-pig and human submucous and myenteric neurons were colabeled for CSE and CBS. Myenteric interstitial cells of Cajal were CSE-immunoreactive. The exogenous H(2)S donor NaHS (0.2-2.5 mmol/L) concentration-dependently increased chloride secretion in human and guinea-pig submucosa/mucosa preparations, but not in the colonic epithelial cell line T84. The secretory response was reduced significantly by tetrodotoxin (0.5 micromol/L), capsaicin desensitization (10 micromol/L), and the transient receptor potentials vanilloid receptor 1 antagonist capsazepine (10 micromol/L). The endogenous H(2)S donor L-cysteine also induced secretion that was diminished significantly by capsaicin desensitization, the CBS inhibitor amino-oxyacetic acid, and the CSE inhibitor propargylglycine. NaHS increased spike discharge in 23% of guinea-pig and 36% of human submucous neurons, but had no effect on Ca(++) mobilization in cultured guinea-pig enteric neurons. This excitatory response was reduced significantly by capsaicin desensitization and capsazepine, but not by glibenclamide (10 micromol/L). CONCLUSIONS: The presence of H(2)S-producing enzymes in human and guinea-pig enteric neurons, the excitatory action on enteric neurons, and the prosecretory effects of NaHS suggest H(2)S as a novel gut-signaling molecule. Its action mainly involves transient receptor potentials vanilloid receptor 1 receptors on extrinsic afferent terminals, which in turn activate enteric neurons.

Adult↗
PubMed2006

The German hospital malnutrition study.

BACKGROUND & AIMS: Malnutrition is frequently observed in chronic and severe diseases and associated with impaired outcome. In Germany general data on prevalence and impact of hospital malnutrition are missing. METHODS: Nutritional state was assessed by subjective global assessment (SGA) and by anthropometric measurements in 1,886 consecutively admitted patients in 13 hospitals (n=1,073, university hospitals; n=813, community or teaching hospitals). Risk factors for malnutrition and the impact of nutritional status on length of hospital stay were analyzed. RESULTS: Malnutrition was diagnosed in 27.4% of patients according to SGA. A low arm muscle area and arm fat area were observed in 11.3% and 17.1%, respectively. Forty-three % of patients 70 years old were malnourished compared to only 7.8% of patients <30 years. The highest prevalence of malnutrition was observed in geriatric (56.2%), oncology (37.6%), and gastroenterology (32.6%) departments. Multivariate analysis revealed three independent risk factors: higher age, polypharmacy, and malignant disease (all P<0.01). Malnutrition was associated with an 43% increase of hospital stay (P<0.001). CONCLUSIONS: In German hospitals every fourth patient is malnourished. Malnutrition is associated with increased length of hospital stay. Higher age, malignant disease and major comorbidity were found to be the main contributors to malnutrition. Adequate nutritional support should be initiated in order to optimize the clinical outcome of these patients.

Adolescent↗
PubMed2006

[Functional and inflammatory bowel disorders].

BACKGROUND: Current investigations suggest that postinflammatory mechanisms might induce subtle changes in the mucosa and enteric nervous system which cannot be readily detected by routine diagnostic measures in subgroups of functional bowel disorders, especially in postinfectious irritable bowel syndrome (PI-IBS). DEFINITION OF PI-IBS: Characteristic of IBS is a symptom cluster with abdominal pain/discomfort and altered bowel movement without pathologic findings during routine work-up. PI-IBS is characterized by acute onset of symptoms, fever, vomiting, diarrhea and/or positive stool culture. EPIDEMIOLOGY: The incidence of PI-IBS is 10-17% in unselected IBS patients of whom 70% develop diarrhea, 26% alternating bowel movement and 8% constipation. PATHOPHYSIOLOGY: Initial gastrointestinal infections might induce subtle ongoing inflammation with consecutive altered mucosal function. Pathomechanisms include mutations within the interleukin-(IL-) 10 promoter polymorphism, hyperplasia of specialized cells including Paneth and enteroendocrine cells (EC) through cytokines as well as inflammatory-mediated modulation of neurones and neurotransmitters within the enteric nervous system. DIAGNOSIS, DIFFERENTIAL DIAGNOSIS, AND THERAPY: It is essential to exclude alarm symptoms. IBS can be positively diagnosed with a sensitivity and specificity of > 90% by standardized questionnaires. Indications of PI-IBS are the acute onset of symptoms, fever, vomiting, diarrhea and/or positive stool culture. Differential diagnoses include lactose intolerance, small bowel bacterial overgrowth, bile acid malabsorption, celiac disease, giardiasis, chronic inflammatory bowel disease, collagenous colitis, and diverticulitis. Therapeutic options in PI-IBS remain symptomatic. So far, no specific anti-inflammatory treatment modalities are available.

Biopsy↗
PubMed2006

The clinical impact of capsule endoscopy: to believe or not to believe.

The study by Estevez et al., 'Diagnostic yield and clinical outcomes after capsule endoscopy in 100 consecutive patients with obscure gastrointestinal bleeding' published in this issue of the journal on a large patient cohort refined a subgroup of patients who could best benefit from capsule endoscopy (CE), e.g. patients with overt bleeding and a requirement for transfusion, and a subgroup of patients in whom CE is clearly not indicated, e.g. patients with overt bleeding and no transfusion requirement. Although the results are promising, some further comments on limitations appear appropriate. The entire small intestine was accessible only in a subgroup of patients and there is a necessity for further technical improvement. A large proportion of the significant lesions detected by CE may also have been detected by conventional diagnostic work-up. The clinical relevance of potentially bleeding lesions that were detected by CE is unresolved. For example, the presence of angiodysplasias per se does not imply a significant bleeding source because their natural history, morphological criteria to characterize the bleeding risk, and occurrence in asymptomatic populations are still unknown. Most of the treatment modifications after CE did not reflect a specific impact of CE on changes in treatment modalities (iron supplementation, eradication of Helicobacter pylori, gluten-free diet, suspension of non-steroidal anti-inflammatory drugs). The authors merit credits for their contribution to our understanding on how to put CE into a rational diagnostic algorithm. It seems to be clear that this decision will not be made by the believer or non-believer in CE alone, but also by health insurance companies.

Capsule Endoscopy↗
PubMed2005

Time-trends in the epidemiology of peptic ulcer bleeding.

OBJECTIVE: Despite the introduction of effective medical treatment of peptic ulcer disease, bleeding is still a frequent complication. The aim of this study was to investigate whether the incidence and the risk profile of peptic ulcer haemorrhage have changed within a 10-year period. MATERIAL AND METHODS: In a prospective epidemiological and observational study the incidence and risk profile of peptic ulcer haemorrhage in Düsseldorf, Germany were compared between two time periods (period A: 1.3.89-28.2.90 and period B: 1.4.99-31.3.2000), involving nine hospitals with both surgical and medical departments. Patients with proven peptic ulcer haemorrhage at endoscopy or operation were included in the study; those with bleeding under defined severe stress conditions were excluded. RESULTS: No differences in bleeding ulcer incidence were observed between periods A and B (51.4 per 100,000 person-years versus 48.7), or for duodenal ulcer (24.9 versus 25.7) or for gastric ulcer bleeding (26.5 versus 23.0). A marked increase in incidence rates was observed with increasing age. In period B, patients with bleeding ulcers were older (56% versus 41% 70 years or older), were usually taking non-steroidal anti-inflammatory drugs (NSAIDs) (45% versus 27%) and were less likely to have a history of ulcer (25% versus 59%) compared with patients in period A. CONCLUSIONS: The persisting high incidence of peptic ulcer disease is a superimposing of two trends: a higher incidence in the growing population of elderly patient with a higher intake of NSAIDs and a lower incidence among younger patients due to a decrease in incidence and improved medical treatment.

Adult↗