PubMed Health⌕ Search

Biomedical subjects

H Mönnikes

Publications and source records attributed to H Mönnikes.

At least 19 recordsLinked to original sources

[Drug therapy for irritable bowel syndrome. What works, what doesn't work and for whom?].

The therapy of patients with irritable bowel syndrome (IBS) is often challenging, especially if a broad spectrum of symptoms is present and trigger factors, such as the influence of diet or stress, are lacking. Current pathogenetic concepts propose central or peripheral alterations that cause disturbed gastrointestinal function (motility, visceral sensitivity) and subsequent symptoms. These alterations are possibly related to psychological (stress, depression, anxiety) and biological (post-infectious residuals, micro-inflammation) influences. Since no universally effective medical treatment is available to treat the causes of the disease, standard medical therapy is symptom directed (especially for pain, constipation and diarrhoea). In addition to well established drugs (like spasmolytics, opioids and laxatives), newly developed compounds including those with other primarily indications (e.g. antidepressants) are available for highly differentiated individualized therapies. New medical approaches which are currently undergoing evaluation, promise further progress in the treatment of IBS.

Antidepressive Agents, Tricyclic↗

Intestinal fluid volumes and transit of dosage forms as assessed by magnetic resonance imaging.

AIM: The gastrointestinal transit of sequentially administered capsules was investigated in relation to the availability of fluid along the intestinal lumen by magnetic resonance imaging. METHODS: Water-sensitive magnetic resonance imaging was performed on 12 healthy subjects during fasting and 1 h after a meal. Specifiable non-disintegrating capsules were administered at 7, 4 and 1 h prior to imaging. RESULTS: While food intake reduced the mean fluid volumes in the small intestine (105 +/- 72 mL vs. 54 +/- 41 mL, P < 0.01) it had no significant effect on the mean fluid volumes in the colon (13 +/- 12 mL vs. 18 +/- 26 mL). The mean number of separated fluid pockets increased in both organs after meal (small intestine: 4 vs. 6, P < 0.05; large intestine: 4 vs. 6, P < 0.05). The distribution of capsules between the small and large intestine was strongly influenced by food (colon: 3 vs. 17 capsules, P < 0.01). CONCLUSIONS: The results show that fluid is not homogeneously distributed along the gut, which likely contributes to the individual variability of drug absorption. Furthermore, transport of fluid and solids through the ileocaecal valve is obviously initiated by a meal-induced gastro-ileocaecal reflex.

Adult↗

Anti-ghrelin Spiegelmer NOX-B11 inhibits neurostimulatory and orexigenic effects of peripheral ghrelin in rats.

BACKGROUND AND AIMS: Ghrelin, the natural ligand of the growth hormone secretagogue receptor 1a, is the most powerful peripherally active orexigenic agent known. In rodents, ghrelin administration stimulates growth hormone release, food intake, and adiposity. Because of these effects, blocking of ghrelin has been widely discussed as a potential treatment for obesity. Spiegelmer NOX-B11 is a synthetic l-oligonucleotide, which was previously shown to bind ghrelin. We examined the effects of NOX-B11 on ghrelin induced neuronal activation and food intake in non-fasted rats. METHODS: Animals received various doses of NOX-B11, inactive control Spiegelmer, or vehicle intravenously. Ghrelin or vehicle was administered intraperitoneally 12 hours later and food intake was measured over four hours. Neuronal activation was assessed as c-Fos-like immunoreactivity in the arcuate nucleus. RESULTS: Treatment with NOX-B11 30 nmol suppressed ghrelin induced c-Fos-like immunoreactivity in the arcuate nucleus and blocked the ghrelin induced increase in food intake within the first half hour after ghrelin injection (mean 1.13 (SEM 0.59) g/kg body weight; 4.94 (0.63) g/kg body weight versus 0.58 (0.58) g/kg body weight; p<0.0001). Treatment with NOX-B11 1 nmol or control Spiegelmer had no effect whereas treatment with NOX-B11 10 nmol showed an intermediate effect on ghrelin induced food intake. CONCLUSIONS: Spiegelmer NOX-B11 suppresses ghrelin induced food intake and c-Fos induction in the arcuate nucleus in rats. The use of an anti-ghrelin Spiegelmer could be an innovative new approach to inhibit the biological action of circulating ghrelin. This may be of particular relevance to conditions associated with elevated plasma ghrelin, such as the Prader-Willi syndrome.

Animals↗

Long-term failure of endoscopic suturing in the treatment of gastroesophageal reflux: a prospective follow-up study.

BACKGROUND AND STUDY AIMS: Several endoscopic antireflux therapies have been marketed, but long-term data on their objective and clinical efficacy are sparse. This report presents prospective 1-year follow-up results, including technical, clinical, and functional success rates, for the first of these treatments to be developed, endoscopic gastroplication (EGP). PATIENTS AND METHODS: A total of 43 EGP procedures were carried out in 38 patients with gastroesophageal reflux disease (GERD). Two or three EndoCinch gastroplications were constructed at the level of the gastric cardia in each patient; five patients were treated twice within 6 - 12 months. Each endoscopic suture joined two gastric folds to each other as a double fold, known as a "gastroplication", in order to narrow the esophagogastric junction. Postprocedure data after 2 months and after 1 year were compared with preoperative data, focusing on symptoms, medication requirements, endoscopic findings, and pH-metry results. RESULTS: In contrast to the findings at 2 months (which showed that 72 % of the sutures were present and that there was a reduction in the percentage of time when the esophageal pH was < 4 from 15.4 % to 8.7 %), the results 1 year after EGP were considered to indicate failure of the treatment in all 38 patients because none of them still had all of the initially placed gastroplications in situ (90 % of gastroplications were lost). The percentage of patients who did not require proton pump inhibitor medication decreased from 52 % at 2 months to only 20 % at 1 year and even more patients had evidence of reflux esophagitis at 1 year (56 %) than had initially demonstrated signs of this (41 %). CONCLUSIONS: EGP has some short-term beneficial effects on clinical symptoms and pH-metry. However, mainly due to the loss of the endoscopically placed sutures, these effects were not maintained at the 1-year follow-up. EGP cannot therefore be recommended for routine clinical use. Better endoscopic methods need to be developed, and they should be adequately tested before being marketed.

Adult↗

Brain activation responses to subliminal or supraliminal rectal stimuli and to auditory stimuli in irritable bowel syndrome.

Visceral hypersensitivity in irritable bowel syndrome (IBS) has been associated with altered cerebral activations in response to visceral stimuli. It is unclear whether these processing alterations are specific for visceral sensation. In this study we aimed to determine by functional magnetic resonance imaging (fMRI) whether cerebral processing of supraliminal and subliminal rectal stimuli and of auditory stimuli is altered in IBS. In eight IBS patients and eight healthy controls, fMRI activations were recorded during auditory and rectal stimulation. Intensities of rectal balloon distension were adapted to the individual threshold of first perception (IPT): subliminal (IPT -10 mmHg), liminal (IPT), or supraliminal (IPT +10 mmHg). IBS patients relative to controls responded with lower activations of the prefrontal cortex (PFC) and anterior cingulate cortex (ACC) to both subliminal and supraliminal stimulation and with higher activation of the hippocampus (HC) to supraliminal stimulation. In IBS patients, not in controls, ACC and HC were also activated by auditory stimulation. In IBS patients, decreased ACC and PFC activation with subliminal and supraliminal rectal stimuli and increased HC activation with supraliminal stimuli suggest disturbances of the associative and emotional processing of visceral sensation. Hyperreactivity to auditory stimuli suggests that altered sensory processing in IBS may not be restricted to visceral sensation.

Acoustic Stimulation↗

International validation of ReQuest in patients with endoscopy-negative gastro-oesophageal reflux disease.

BACKGROUND: Reflux Questionnaire (ReQuest), a newly developed gastro-oesophageal reflux disease-sensitive scale, can be used to reliably evaluate the effect of treatment on gastro-oesophageal reflux disease symptoms. AIM: International validation of this scale, in patients suffering from endoscopy-negative gastro-oesophageal reflux disease. METHODS: In this open, multicentre and multinational clinical trial 840 endoscopy-negative gastro-oesophageal reflux disease patients received pantoprazole 20 mg daily for 28 days. The long and short versions of ReQuest were completed both in the pre-treatment and treatment phases. For scale development an item reduction analysis was performed. Internal consistency, test-retest reliability and responsiveness were calculated for psychometric analysis. Construct validity was evaluated by comparison with the Gastrointestinal Symptom Rating Scale and the Psychological General Well-being questionnaire by means of correlation coefficients. RESULTS: Factor analyses confirmed the content validity of both long and short version of ReQuest. Psychometric calculations proved high internal consistency (Cronbach's alpha: 0.9), test-retest reliability [Intraclass Correlation Coefficient: 0.9 (long vs. long) and 0.8 (short vs. short)], and responsiveness (Responsiveness Index 320.3) of the scale, for which also good construct validity was achieved (correlation coefficient: Gastrointestinal Symptom Rating Scale -0.6; Psychological General Well-being -0.4). CONCLUSION: ReQuest proved valid, reliable, and responsive in this multinational clinical trial to evaluate treatment response in endoscopy-negative gastro-oesophageal reflux disease patients.

Adult↗

Evaluation of GERD symptoms during therapy. Part II. Psychometric evaluation and validation of the new questionnaire ReQuest in erosive GERD.

BACKGROUND/AIMS: Evaluation of the response of gastroesophageal reflux disease (GERD) symptoms to treatment would be facilitated by a brief, valid, reliable and responsive, self-assessed GERD-sensitive scale. We therefore developed the Reflux Questionnaire (ReQuest). This publication describes the psychometric evaluation and validation of ReQuest. METHODS: This second phase of development was based on data from a clinical trial of patients with erosive GERD who received pantoprazole 20 or 40 mg daily for 28 days and completed weekly the long, and daily the short version of ReQuest. The psychometric analyses of ReQuest included internal consistency, test-retest reliability and responsiveness. Construct validity was evaluated by comparison with the Gastrointestinal Symptom Rating Scale (GSRS) and the Psychological General Well-Being (PGWB) scale. RESULTS: Validation of ReQuest indicated very high internal consistency (Cronbach's alpha = 0.90) and test-retest reliability (intraclass correlation coefficient 0.94 (long-long) and 0.86 (short-short)). This was also the case for the two subscales ReQuest-GI and ReQuest-WSO with Cronbach's alpha coefficients of 0.84 and 0.81. Responsiveness was high with a responsiveness index of >0.8 at day 28. Construct validity was good. CONCLUSION: ReQuest is a highly reliable, valid and responsive self-assessment tool for evaluating treatment response in patients with erosive GERD, and can be applied daily.

Endpoint Determination↗

Evaluation of GERD symptoms during therapy. Part I. Development of the new GERD questionnaire ReQuest.

BACKGROUND/AIMS: The changes in gastroesophageal reflux disease (GERD)-related symptoms on treatment are variously described, but currently available questionnaires have shortcomings. We therefore developed a self-assessment reflux questionnaire (ReQuest). This article describes the process of development and testing. MATERIALS AND METHODS: For the first version of ReQuest the symptom spectrum of GERD and the various symptom descriptions were investigated. The 67 identified symptom descriptions were condensed empirically into 6 dimensions, to which a 7th dimension on general well-being was added. The symptom burden of the dimensions was measured by frequency and/or intensity. ReQuest was translated into different languages and then tested in focus groups. The initial validation was based on data from a clinical trial of patients with erosive GERD, treated with pantoprazole 20 or 40 mg daily for 28 days. Factor analyses determined the contribution of each symptom to the different dimensions. Additionally, correlation analyses between the identified factors and the dimensions were performed. RESULTS: On the basis of factor analyses, ReQuest was reduced to a 60-item scale. The factors generated correlated strongly with the dimensions and confirmed the empirical process mathematically. CONCLUSION: ReQuest provides a valuable, self-assessment tool for evaluating the daily treatment response in patients with erosive GERD.

Adult↗

Systematic review: do we need a new gastro-oesophageal reflux disease questionnaire?

BACKGROUND: Gastro-oesophageal reflux disease (GERD) is highly prevalent in Western countries. Because the majority of patients do not present with endoscopic abnormalities, the assessment of the symptom severity and quality of life, and their response to treatment, has become increasingly important. Self-assessed symptom questionnaires are now key instruments in clinical trials. AIM: To evaluate the validity of available GERD measurement tools. METHODS: An ideal GERD symptom assessment instrument, suitable as a primary end-point for clinical trials, should possess the following characteristics: (i) be sensitive in patients with GERD; (ii) cover the frequency and intensity of typical and atypical GERD symptoms; (iii) be multidimensional (cover all symptom dimensions); (iv) have proven psychometric properties (validity, reliability and responsiveness); (v) be practical and economical; (vi) be self-assessed; (vii) use 'word pictures' which are easy to understand for patients; (viii) respond rapidly to changes (responsiveness over short time intervals); (ix) be used daily to assess changes during and after therapy; and (x) be valid in different languages for international use. RESULTS: A literature review revealed five scales that met some of the above characteristics, but did not fulfil all criteria. CONCLUSION: There is a need for a new evaluative tool for the assessment of GERD symptoms and their response to therapy.

Dyspepsia↗

Oesophageal transport of solid dosage forms depends on body position, swallowing volume and pharyngeal propulsion velocity.

Knowledge about transit of solid dosage forms (SDF) in the gastrointestinal tract is incomplete. Detection of magnetically marked capsules (MMC) via superconducting quantum interference device (SQUID) allows monitoring of oesophageal transport of SDF with high tempospatial resolution. The aim of the study was to investigate the influence of body position, volume at swallowing, and oesophageal motility on orogastric transport of SDF. In 360 measurements we determined tempospatial characteristics of orogastric transit of SDFs by a SQUID device in six volunteers. They swallowed MMCs with various amounts of water in upright and supine position with and without simultaneous oesophageal manometry. Orogastric transit time, oesophageal transport velocity and rate of oesophageal retention of SDF depend on swallowing volume and body position at all experimental conditions. At 50 mL water bolus and in upright position, the retention rate depends on the pharyngeal propulsion velocity, and the transport velocity of MMCs in the oesophageal body are faster than the propulsive oesophageal contractions. Body position, swallowing volume and pharyngeal propulsion velocity markedly influence the oesophageal transport of SDF. They should be taken in upright body position with at least 50 mL of water to minimize entrapment in the oesophagus.

Adult↗

Cocaine- and amphetamine-regulated transcript stimulates colonic motility via central CRF receptor activation and peripheral cholinergic pathways in fed, conscious rats.

Many neuropeptides participating in the hypothalamic control of feeding behaviour and satiety have been shown to be additionally involved in the autonomic control of gastrointestinal (GI) functions. Recently, the neuropeptide cocaine- and amphetamine-regulated transcript (CART) has been indicated to function as an anorectic substance in the brain. In the present study we examine the hypothesis that CART is involved in the modulation of GI motility. Colonic transit time was measured after peripheral and central injection of CART in fed and freely moving Sprague-Dawley rats. Intracerebroventricular injection of synthetic CART (55-102) (190 pmol and 1.9 nmol per 10 microL and saline controls) decreased the colonic transit time of conscious rats up to 46%. In contrast, i.p. injection of CART (55-102) (1.9 nmol and 19 nmol kg(-1) BW and saline controls) had no effect on colonic motility. Central administration of a CRF receptor antagonist (2.8 nmol) prior to central CART administration antagonized the CART-induced stimulation of colonic transit. Pretreatment with the peripherally acting cholinergic antagonist atropin methyl nitrate (0.1 mg kg(-1) i.p.) blocked the stimulatory CART effect on colonic motor function. The results suggest that CART acts in the central nervous system to modulate behavioural motor function via a central CRF receptor-dependent mechanism and peripheral cholinergic pathways.

Animals↗

Electrogastrography as a diagnostic tool for delayed gastric emptying in functional dyspepsia and irritable bowel syndrome.

Several pathophysiological mechanisms have been proposed in functional gastrointestinal (GI) disorders, e.g. altered GI motility and sensitivity. The aim of this study was to investigate gastric electrical activity (GEA) in patients with functional dyspepsia (FD) or irritable bowel syndrome (IBS) compared with healthy controls (HC), and to assess if abdominal symptoms and delayed gastric emptying are associated with alterations in GEA, as determined by electrogastrography (EGG). Forty patients with FD, IBS or both were compared with 22 HC. EGG was performed before and after a standard meal. Frequencies and amplitudes pre- and post-prandially were analysed. Furthermore, gastric emptying and symptom scores were assessed. Eight of 40 patients (20%; three FD, three IBS, two FD and IBS) had delayed gastric emptying. Disturbed gastric emptying and lack of a postprandial increase in the EGG amplitude were significantly correlated (r = 0.8; P < 0.005). No differences between controls and patients were observed in the distribution of EGG frequencies. Treatment with the prokinetically active macrolide erythromycin improved gastric emptying, GEA and symptoms (n = 4). The data suggest that EGG could be useful as a diagnostic tool in patients with FD and IBS to identify a subgroup of patients with delayed gastric emptying.

Adolescent↗

[Acute liver failure following the use of ecstasy (MDMA)].

The use of "ecstasy" (Methylenedioxymethamphetamine) as a recreational drug is increasing in europe since the 1980's. Aside intended psychological effects the use of ecstasy can be followed by symptoms of intoxication; complications include toxic hepatic damage up to acute hepatic failure. This case-report is about a 17-year old female patient who regularly used "ecstasy" over a six-month period. Two days after the last use of "ecstasy", she reported to her general practitioner with nausea, vomiting, abdominal pain and jaundice. Within 10 days the patient developed acute liver failure. With criteria for liver transplantation fulfilled she was listed for orthotopic liver transplantation of high urgency which was carried out only one day later. Histological examination of the explanted liver showed evidence for a toxic fulminant hepatitis. After transplantation the patient made a full recovery and was released from hospital on day 26 after transplantation. At the first control after six months the patient was in good physical and nutritional condition, serological parameters were normal and ultrasound examination of the transplanted liver was unremarkable. The ethiopathology of "ecstasy"-induced hepatotoxicity, which can occur dose-independently with a symptom-free period from days to weeks after ingestion is not yet fully understood. Possible mechanisms of hepatic damage include influence of MDMA on body temperature regulation, harmful effects of the substance or further components of the "ecstasy"-tablets on the liver cell or a genetic vulnerability of some individuals against amphetamines and amphetamine derivates. There are no parameters existing which could predict the course and severity of "ecstasy"-induced hepatopathy. Especially in young patients with symptoms of hepatic damage frequent controls of clinical status and relevant laboratory parameters are of great importance. Patient transfer to a specialised centre should follow as early as possible; at the latest, when coagulopathy occurs.

Adolescent↗

Review on the influence of stress on immune mediators, neuropeptides and hormones with relevance for inflammatory bowel disease.

Stress has long been postulated to influence the progression of inflammatory bowel disease (IBD). Our current understanding of the relationship between stress and IBD is still limited, and hence explanation for the occurrence of relapses has remained largely speculative. Stress affects the immune system, the neuroendocrine system and the intestinal epithelia. Stress induces the release of pro-inflammatory Th1 cytokines and neuropeptides, such as tachykinins. Thereby, stress may induce alterations of the intestinal epithelium via the interaction of the neuroendocrine and immune system and may induce relapses of IBD. The present review focuses on this network and highlights the role of distinct mediators and mechanisms, i.e. neurotransmitters, hormones and immune cells, which are involved in the response to stress on the one hand, and contribute to the onset, progression or relapses of IBD on the other.

Animals↗

Investigation of gastrointestinal transport by magnetic marker localization.

The method of magnetic marker monitoring MMM with a biomagnetic measurement system allows the tracking of the transport of solid drug forms with high spatiotemporal resolution. This technique enables to display the path and the disintegration of the magnetic marked pharmaceutical dosage form via the decrease of its magnetic moment. The method was used to assess exogenous factor on the esophageal transport of orally administered solid drug forms in five healthy volunteers. In a drug delivery study we have applied the MMM to monitor the path of a tablet during the gastrointestinal passage and to visualize the disintegration in the small intestine by the magnetic moment of the tablet. The signal to noise ratio of the measurement data was improved by ICA filtering.

Acetaminophen↗

Excitatory stimulation of neurons in the arcuate nucleus inhibits gastric acid secretion via vagal pathways in anesthetized rats.

It is well established that autonomic control of gastrointestinal function is modulated by central autonomic neurotransmission. In this context it has been shown that gastrointestinal motility and secretion can be modulated by exogenous neuropeptides microinjected into the paraventricular nucleus of the hypothalamus (PVN). Furthermore, there is considerable evidence suggesting that neurons projecting from the arcuate nucleus (Arc) to the PVN may be the source of endogenous neuropeptide release in the PVN. This poses the question whether stimulation of neurons in the arcuate nucleus, e.g. by an excitatory amino acid, alters gastrointestinal function. In the present study, we investigated the effect of an excitatory amino acid, kainate, microinjected into the arcuate nucleus on gastric acid secretion in urethane-anesthetized rats. Kainate (140 pmol/rat) bilaterally microinjected into the Arc induced an significant inhibition of pentagastrin (PG) stimulated (16 mg/kg per h) gastric acid secretion throughout an observation period of 120 min after microinjection. Microinjection of kainate into hypothalamic areas outside the arcuate nucleus did not modify gastric secretion. Bilateral cervical vagotomy blocked the effect of kainate injected into the Arc on PG-stimulated gastric acid secretion. These data show that gastric secretory function can be modulated by stimulation of neuronal activity in the Arc via efferent vagal pathways. The results suggest that the arcuate nucleus is a forebrain area involved in the CNS regulation of gastrointestinal function.

Anesthetics, Intravenous↗