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Biomedical subjects

W L Hasler

Publications and source records attributed to W L Hasler.

At least 19 recordsLinked to original sources
PubMed2006

Treatment of gastroparesis: a multidisciplinary clinical review.

This clinical review on the treatment of patients with gastroparesis is a consensus document developed by the American Motility Society Task Force on Gastroparesis. It is a multidisciplinary effort with input from gastroenterologists and other specialists who are involved in the care of patients with gastroparesis. To provide practical guidelines for treatment, this document covers results of published research studies in the literature and areas developed by consensus agreement where clinical research trials remain lacking in the field of gastroparesis.

Consensus Statements as Topic↗
PubMed2004

Directed endoscopic mucosal mapping of normal and dysrhythmic gastric slow waves in healthy humans.

Frequency and amplitude characteristics of normal and dysrhythmic slow waves in different gastric regions are poorly characterized. Using endoscopic mucosal mapping, we quantified slow wave frequency and power at predetermined sites under control conditions and with glucagon. Twelve healthy volunteers underwent gastroscopy with midazolam. Bipolar recording electrodes were directed to 12, 7, and 2 cm proximal to the pylorus along the greater and lesser curvatures. Dominant frequencies at all sites were 2.96 +/- 0.07 cycles min(-1) (cpm). Powers of the dominant frequency were 59 +/- 7% lower 12 cm vs 2 cm from the pylorus (P < 0.01), but were similar along the greater and lesser curvatures. Glucagon (0.3 mg IV) decreased dominant frequencies (1.40 +/- 0.10 cpm, P < 0.01) and elicited power reductions which varied by region (36 +/- 37% at 12 cm vs 79 +/- 20% at 2 cm, P < 0.01). Comparing dominant frequencies from mucosal recordings and electrogastrography revealed minimal slow wave uncoupling. In conclusion, endoscopic mucosal mapping demonstrates slow wave power gradients from the proximal to distal stomach under normal conditions. Glucagon evokes bradygastria with minimal uncoupling and elicits inhibitory effects on slow wave power which are more potent in the distal antrum. This method provides insight into the mechanisms of action of gastric slow wave dysrhythmic stimuli.

Adult↗
PubMed2003

Systematic review: Abdominal and pelvic surgery in patients with irritable bowel syndrome.

AIM: To systematically review research on the prevalence of abdominal and pelvic surgery in patients with irritable bowel syndrome. METHODS: Computer searches of MEDLINE, EMBASE and Current Contents were performed independently by both investigators to identify appropriate studies. Primary study selection criteria included: (i) population-based samples of adult irritable bowel syndrome patients; (ii) the use of appropriate symptom-based criteria to identify irritable bowel syndrome patients; and (iii) comparison of the prevalence of abdominal and pelvic surgery in irritable bowel syndrome patients vs. control populations. Secondary analysis was performed on published studies of referral populations and case series. RESULTS: Two population-based studies met the primary study selection criteria and revealed an increased prevalence of surgery in irritable bowel syndrome patients vs. controls for cholecystectomy (4.6% vs. 2.4%, respectively; odds ratio, 1.9; 95% confidence interval, 1.2-3.2) and hysterectomy (18% vs. 12%, respectively; odds ratio, 1.6; 95% confidence interval, 1.1-2.2). Secondary analysis revealed an increased prevalence of appendectomy and other abdominal and pelvic surgery in irritable bowel syndrome patients. CONCLUSIONS: Irritable bowel syndrome is associated with a disproportionately high prevalence of abdominal and pelvic surgery, but most studies exhibit sub-optimal study design and do not define the factors causing the increased prevalence of surgery in these patients.

Abdomen↗
PubMed2003

Electrogastrography: a document prepared by the gastric section of the American Motility Society Clinical GI Motility Testing Task Force.

The objective of this document is to present the consensus opinion of the American Motility Society Clinical GI Motility Testing Task Force on the performance and clinical utility of electrogastrography (EGG). EGG is a non-invasive means of recording human gastric myoelectrical activity or slow waves from cutaneous leads placed over the stomach. In healthy volunteers, EGG tracings exhibit sinusoidal waveforms with a predominant frequency of 3 cycles per minute (cpm). Clinical studies have shown good correlation of these cutaneous recordings with those acquired from serosally implanted electrodes. The amplitude of the EGG waveform increases with ingestion of caloric or non-caloric meals. Some patients with nausea, vomiting, or other dyspeptic symptoms exhibit EGG rhythm disturbances or blunting of meal-evoked EGG signal amplitude increases. These abnormalities correlate to some degree with delayed gastric emptying of solids. In selected patients, EGG may be complementary to gastric emptying testing. To date, no therapies have convincingly demonstrated in controlled studies that correcting abnormalities detected by EGG improves upper gastrointestinal symptoms. Proposed clinical indications for performance of EGG in patients with unexplained nausea, vomiting and dyspeptic symptoms must be validated by prospective controlled investigations.

Digestive System Physiological Phenomena↗
PubMed2001

Gastric distention correlates with activation of multiple cortical and subcortical regions.

BACKGROUND & AIMS: The pathophysiology of functional dyspepsia may involve abnormal processing of visceral stimuli at the level of the central nervous system. There is accumulating evidence that visceral and somatic pain processing in the brain share common neuronal substrates. However, the cerebral loci that process sensory information from the stomach are unknown. The aim of this study was to localize the human brain regions that are activated by gastric distention. METHODS: Brain (15)O-water positron emission tomography was performed in 15 right-handed healthy volunteers during baseline and distal gastric distentions to 10 mm Hg, 20 mm Hg, threshold pain, and moderate pain. Pain, nausea, and bloating were rated during baseline and distentions (0-5 scale). Statistical subtraction analysis of brain images was performed between distentions and baseline. RESULTS: Symptoms increased with distending stimulus intensity (maximum pain, 2.1 +/- 0.4; nausea, 2.2 +/- 0.4; bloating, 3.7 +/- 0.2). Paralleling increases in distention stimulus and symptoms, progressive increases in activation (P < or = 0.05), were observed in the thalami, insula bilaterally, anterior cingulate cortex, caudate nuclei, brain stem periaqueductal gray matter, cerebellum, and occipital cortex. CONCLUSIONS: Symptomatic gastric distention activates structures implicated in somatic pain processing, supporting the notion of a common cerebral pain network.

Adult↗
PubMed2001

Effects of nutrients and serotonin 5-HT3 antagonism on symptoms evoked by distal gastric distension in humans.

Distal gastric distension may contribute to meal-related dyspeptic symptoms. This study's aims were to determine the effects of distinct nutrient classes on symptoms induced by distal gastric distension and their dependence on 5-hydroxytryptamine(3) (5-HT3) receptors. Nine healthy subjects rated pain, nausea, and bloating induced by isobaric distal gastric distensions (6-24 mmHg) during duodenal lipid, carbohydrate, protein, or saline perfusion after treatment with placebo or the 5-HT3 receptor antagonist granisetron (10 microg/kg iv). Distensions produced greater pain, nausea, and bloating with lipid at 1.5 kcal/min compared with saline (P < or = 0.02), primarily because of greater distal gastric volumes at each distending pressure. In contrast, carbohydrate and protein had no significant effect. At 3 kcal/min, lipid increased symptoms through a volume-independent as well as a volume-dependent effect. Granisetron did not affect symptom perception or gastric pressure-volume relationships. In conclusion, isobaric distal gastric distension produces more intense symptoms during duodenal lipid compared with saline perfusion. Symptom perception during distal gastric distension is unaffected by 5-HT3 receptor antagonism.

Adult↗
PubMed2001

Nizatidine enhances the gastrocolonic response and the colonic peristaltic reflex in humans.

Animal studies demonstrate that nizatidine, an H2-receptor inhibitor, may enhance colonic activity independent of its effect on acid secretion. The effect of nizatidine on human colonic motility is unknown. We evaluated the potential prokinetic property of nizatidine in 12 healthy subjects (10 men and 2 women, age 21-46 years). Each subject received either nizatidine (600 mg), famotidine (80 mg, a H2-receptor inhibitor used as a control), or a placebo, on separate days in randomized order at least 3 days apart. Following an overnight fast, a three-lumen catheter fitted with a stimulus balloon and two barostat bags was placed in the descending colon. The gastrocolonic response was tested by antral balloon inflation and the colonic peristaltic reflex was evaluated by colonic distension. Changes in colonic motility were assessed by volume changes in the barostat bags. Antral distension evoked volume-dependent increases in colonic motility, maximal at a 300-ml inflation, as demonstrated by a reduced bag volume. Nizatidine enhanced colonic motility in response to antral distension at 200 and 300 ml, compared with famotidine and placebo. Colonic distension evoked volume-dependent increases in colonic motility proximal to the stimulus balloon. Compared with famotidine and placebo, nizatidine enhanced the ascending and descending contractile limbs of the peristaltic reflex but did not affect relaxation distal to the balloon. In conclusion, nizatidine enhanced the gastrocolonic response and the colonic peristaltic reflex in healthy subjects. Further research on the prokinetic action of nizatidine in the colon may lead to novel treatments for idiopathic constipation.

Adult↗