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Query: UMLS:C0013395 (dyspepsia)
 4,879 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gastric function is finely modulated by a series of neurological mechanisms, so that gastric digestion is normally not perceived. Alteration of these control mechanisms may lead to different situations, which are frequently associated with symptoms. An impaired tonic contraction of the proximal stomach, that is, an impaired gastric tone, results in gastroparesis. Patients with functional dyspepsia, and also patients with achalasia, have impaired meal accommodation of the stomach. Interestingly, patients with functional dyspepsia may also have a sensory dysfunction, and both dysfunctions could play a synergistic role. However, the sensory dysfunction in dyspepsia, particularly the types of afferent fibres affected, and the mechanisms of impaired accommodation, still remain to be characterized. Evaluation of gastric function has been approached using the barostat. However, the barostat has limitations and potential technical pitfalls that require proper attention. Meal ingestion induces a variety of reflexes and the net result is a relaxation of the stomach. However, gastric reflexes can be best evaluated with the stomach empty, when the stimuli are applied at a different site. Nevertheless, altered reflex responses may be difficult to interpret. For instance, absent or decreased relaxatory responses may equally correspond to a gastroparetic stomach without tone or to a dyspeptic stomach unable to relax. In this context, it may be important to measure basal tone. Distension of the stomach by means of the barostat has been also used to test gastric sensitivity. However, recent studies have shown that perception of gastric distension relays on stimulation of tension receptors; since wall tension depends on both pressure and volume, distension with the barostat may be difficult to standardize. Hopefully, a battery of tests may become available in the near future for a complete neuromuscular evaluation of the gut.
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PMID:Gastric neurology: evolving concepts and techniques. 983 Dec 67

There is considerable debate about whether the mucous neck cell (MNC) in the mucosa of the gastric corpus is merely a transit cell population, intermediate between gastric stem cells and the differentiated zymogenic (chief or peptic) cell lineages, or has distinct functions of its own. To cast light on these possibilities, the secretory phenotype of the MNC has been examined. Archival gastric body samples from non-ulcer dyspepsia biopsies and gastrectomies performed for peptic ulcer disease were stained with antibodies to the trefoil peptides TFF1/pS2 and TFF2/SP, pancreatic secretory trypsin inhibitor (PSTI), epidermal growth factor (EGF) and its receptor (EGFR), and to the MUC1 gene product--HMFG2. Human MNCs express PSTI, TFF1/pS2, TFF2/SP, and EGF proteins, while rat MNCs express TFF2/SP; the mucin contained in the MNCs is diastase/periodic acid Schiff (D/PAS)-positive and stains with human milk fat globulin (HMFG2). The canaliculi but not the cytoplasm of adjacent parietal cells were also decorated focally by D/PAS, by HMFG2, and by antibodies to TFF2/SP and TFF1/pS2. These findings favour the hypothesis that MNCs have a defined phenotype and are thus a separate and distinct cell lineage, secreting a number of luminally-active peptides which protect the gastric mucosa, and in particular the adjacent parietal cells, from the effects of secreted gastric acid. Moreover, a considerable degree of similarity in secretory profile is noted between MNCs and the so-called 'reparative lineages' in the gut--the ulcer-associated cell lineage (UACL) and hyperplastic polyp epithelium. If, on the other hand, the MNCs are indeed a transit population differentiating into zymogenic or peptic cells, then it is clear that having differentiated into one secretory phenotype producing a range of peptides, the MNC then proceeds to differentiate into a cell with a totally different secretory phenotype, a phenomenon unique in gastrointestinal cell lineage relationships.
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PMID:The mucous neck cell in the human gastric corpus: a distinctive, functional cell lineage. 1039 88

Many of the symptoms characteristic of the functional gastrointestinal disorders (FGID) are consistent with dysfunction of the motor and/or sensory apparatus of the digestive tract. Those aspects of sensorimotor dysfunction most relevant to the FGID include alterations in: gut contractile activity; myoelectrical activity; tone and compliance; and transit, as well as an enhanced sensitivity to distension, in each region of the gastrointestinal tract. Assessment of these phenomena involves a number of techniques, some well established and others requiring further validation. Using such techniques, researchers have reported a wide range of alterations in sensory and in motor function in the FGID. Importantly, however, relationships between such dysfunction and symptoms have been relatively weak, and so the clinical relevance of the former remains unclear. Moreover, the proportions of patients in the various symptom subgroups who display dysfunction, and the extent and severity of their symptoms, require better characterization. On a positive note, progress is occurring on several fronts, especially in relation to functional dyspepsia and irritable bowel syndrome, and based on the data gathered to date, a number of areas where further advances are required can be highlighted.
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PMID:Principles of applied neurogastroenterology: physiology/motility-sensation. 1045 40

While widely used in research, the 1991 Rome criteria for the gastroduodenal disorders, especially symptom subgroups in dyspepsia, remain contentious. After a comprehensive literature search, a consensus-based approach was applied, supplemented by input from international experts who reviewed the report. Three functional gastroduodenal disorders are defined. Functional dyspepsia is persistent or recurrent pain or discomfort centered in the upper abdomen; evidence of organic disease likely to explain the symptoms is absent, including at upper endoscopy. Discomfort refers to a subjective, negative feeling that may be characterized by or associated with a number of non-painful symptoms including upper abdominal fullness, early satiety, bloating, or nausea. A dyspepsia subgroup classification is proposed for research purposes, based on the predominant (most bothersome) symptom: (a) ulcer-like dyspepsia when pain (from mild to severe) is the predominant symptom, and (b) dysmotility-like dyspepsia when discomfort (not pain) is the predominant symptom. This classification is supported by recent evidence suggesting that predominant symptoms, but not symptom clusters, identify subgroups with distinct underlying pathophysiological disturbances and responses to treatment. Aerophagia is an unusual complaint characterized by air swallowing that is objectively observed and troublesome repetitive belching. Functional vomiting refers to frequent episodes of recurrent vomiting that is not self-induced nor medication induced, and occurs in the absence of eating disorders, major psychiatric diseases, abnormalities in the gut or central nervous system, or metabolic diseases that can explain the symptom. The current classification requires careful validation but the criteria should be of value in future research.
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PMID:Functional gastroduodenal disorders. 1045 43

Several serotonin (5-HT) receptor subtypes have been defined by pharmacological responses to selective agonists and antagonists and by pathways of receptor-effector coupling. Using molecular techniques, additional receptor subtypes have been described. 5-HT receptors are prevalent in the central nervous system and gut and participate in induction of emesis. 5-HT3 antagonists are used to prevent emesis from cancer chemotherapy and also demonstrate efficacy in radiation-induced nausea, postoperative nausea, hyperemesis gravidarum, and nausea and vomiting with the acquired immunodeficiency syndrome. 5-HT4 agonists exhibit prokinetic properties in nauseated patients with gastroparesis and functional dyspepsia. Conversely, 5-HT4 antagonists have antiemetic activity in some experimental models. The 5-HT1D receptor agonist sumatriptan reduces emesis with migraine headaches and in cyclic vomiting syndrome, most likely via action on central nervous system sites. In other models, 5-HT1A and 5-HT2A/5-HT2C agonists exhibit antiemetic properties. The utility of 5-HT receptor ligands in treating emesis is the subject of active investigation.
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PMID:Serotonin receptor physiology: relation to emesis. 1049 49

Dyspepsia drains a substantial proportion of healthcare resources in industrialized countries and an appropriate management strategy is needed. An aetiological role for Helicobacter pylori infection has been demonstrated in a number of pathological conditions associated with dyspepsia, such as peptic ulcer and gastric malignancies, but not in functional dyspepsia. Endoscopy and diagnosis-based treatment, H. pylori testing and eradication therapy, history taking and empirical therapy, are the main tools that are currently available for managing patients with upper gastrointestinal symptoms. Endoscopy identifies malignancies and organic diseases of the proximal gut and therefore provides reassurance to both doctors and patients. It should be recommended in older patients with suspicious symptoms and it has proven to be more cost-effective than empirical H2-receptor antagonists in patients with ulcer-like symptoms. Empirical eradication in all dyspeptics without suspicious symptoms is a cost-effective approach that cures the majority of peptic ulcers. Nevertheless, it does not control symptoms in the majority of patients, it may exacerbate gastro-oesophageal reflux disease, and it encourages antibiotic resistance. The realities of current clinical practice require empirical therapy in most, if not all, the dyspeptics seen by general practitioners. A detailed history taking can help to diagnose gastro-oesophageal reflux disease and to identify suspicious symptoms. Furthermore, identification of dyspepsia subgroups may provide guidance for empirical therapy. Nevertheless, even analysis of individual symptoms does not provide a sufficient diagnostic yield to differentiate functional from organic dyspepsia and appropriate investigations are needed in patients with poor response to short-term therapy or frequent relapses.
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PMID:Review article: the continuing dilemma of dyspepsia. 1105 Apr 84

Fedotozine [(1R)-1-phenyl-1-[(3,4,5-trimethoxy)benzyloxymethyl]-N,N- dimethyl-n-propylamine, (2S,3S-tartrate] is derived from the arylacetamide series. As with other compounds of this series, fedotozine is more or less selective of kappa(1)-opioid receptors and particularly for the kappa(1a)-receptor subtype, where it acts as an agonist. Pharmacological studies have shown that fedotozine exerts a peripheral antinociceptive action, comparable with that of other kappa-agonists. Its main effects have been demonstrated at the level of the afferent nerve pathways originating from the gut. Fedotozine alters the processing of visceral sensations along these pathways and hence, the perception of gut stimuli at the brain level. It modifies reflexes induced in various pathological conditions, like experimental inflammation of the gut, chemically-induced peritonitis or post-operative ileus. Fedotozine also decreases the nociceptive reflexes triggered by noxious gut distension in animals. In humans, fedotozine decreases the perception of gut distension, both in physiological and pathological conditions. Clinical trials undertaken in patients with functional digestive disorders, non-ulcer dyspepsia and irritable bowel syndrome, have shown that fedotozine relieves abdominal pain in these patients in 6-week treatments. kappa-Opioid receptors remain an interesting area for future development of new treatments for abdominal pain in patients with functional digestive disorders.
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PMID:Pharmacology and clinical experience with fedotozine. 1111 83

Dyspepsia refers to pain or discomfort centered in the upper abdomen. This symptom is remarkably common, with 1-year prevalence rates averaging 25% in the community. Symptoms suggestive of the irritable bowel syndrome and reflux disease frequently overlap but do not form part of the definition of dyspepsia. Electrical and other stimuli can cause similar or different symptoms in various patients, and even the site to which symptoms are referred varies considerably. Dyspeptic symptoms are therefore a relatively poor guide to the origin or nature of any "disturbances" in the gut. Identification of patients who require further investigation to rule out serious structural disease, such as peptic ulcer disease or cancer, is a key issue because unaided clinical diagnosis is unreliable. The use of an age threshold (typically 45 years) and the identification of alarm features, including weight loss, repeated vomiting, and signs of bleeding, seem to be valid on the basis of the limited evidence available. Dyspeptic symptoms fall into distinct subgroups resembling the perceived clinical entities of ulcer-like and dysmotility-like dyspepsia. Unfortunately, because of overlap with reflux symptoms and between the subgroups, the clinical significance of these groups remains highly questionable. A focus on symptom predominance may be more rewarding. Lack of validated outcome measures has hampered clinical studies and has led to the development of complex outcome measures that integrate and weigh different symptoms or other indirect indicators of outcome into a general score. Further testing and validation are in progress.
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PMID:Dyspepsia. 1134 16

Disorders of augmented visceral perception include functional (or nonulcer) dyspepsia and irritable bowel syndrome (IBS). Enhancement of luminal perception can result from alterations in normal elastic gut wall properties or exaggerated responsiveness of visceral sensory nerve pathways. Standard therapies for functional dyspepsia are effective in subsets of patients and may act in part by compensating for gastric hypersensitivity (as with acid-suppressing drugs) or by enhancing gastric compliance (as with some motor-stimulating agents). Likewise, conventional treatments of patients with IBS reduce visceral perception via effects on sensory nerve function (fiber supplements) or luminal wall properties (antispasmodic drugs). Antidepressants are increasingly used in patients with functional dyspepsia or IBS. These drugs have several purported mechanisms, including 1) luminal relaxation, 2) blunting of visceral hypersensitivity, and 3) modulation of central nervous system pain processing pathways. The efficacy of available and investigational agents that act as visceral analgesics or luminal relaxants is an area of intense pharmaceutical research.
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PMID:Augmented Visceral Perception. 1146 93

Microbial and fermentation changes in the ingesta of the large intestine and their influence on the pathogenesis of acute lactic acidosis were studied in 4 cows fitted with permanent cannulas in the ileum and cecum. Feed mixture containing 65% of maize was infused into the cecum for several days in amounts of 2 and 4 kg per day. The daily amount was divided in 8 equal portions and given with 3 l of warm physiologic saline solution. During the period of ad libitum feeding of hay, the pH values in cecal digesta were 7.4 to 7.6 and the amount of total volatile fatty acids 40-60 mmol/kg with high molar percentage (87-90 mol%) of acetic acid. As to lactic acid only the L(+) lactic isomer was found in a concentration of about 0.4 mmol/kg. Infusion of low amounts of starch induced mild lactic acid fermentation in the cecum associated with a pronounced increase in the concentration of L(+) and D (-) lactic acid to peak levels of 80 +/- 10 mmol/kg and 7 +/- 1 mmol/kg, respectively. Lactic acid fermentation ceased within 2 to 3 days indicating that the gut microflora had adapted to the starch infusion. Slight decreases of blood pH and bicarbonates in blood as well as a moderate increase of netto acid-base excretion in urine indicated mild changes of acid-base balance, but clinically no pathological symptoms were observed. Higher amounts of infused starch caused pronounced lactic acid production in the large intestine which persisted throughout the experiment. Peak L(+) and D(-) lactic acid concentration in cecal digesta reached on the average 137 +/- 16 mmol/kg and 45 +/- 7 mmol/kg respectively. Significant decreases of blood pH values from 7.41 +/- 0.02 to 7.18 +/- 0.08 (P < 0.001), actual bicarbonate from 28.2 +/- 3.2 to 11.0 +/- 2.6 mmol/l (P < 0.001) and base excess from 3.9 +/- 3.6 to -15.2 +/- 3.8 mmol/l (P < 0.001) were observed. D (-) lactic acid concentration in blood increased to 3.2 +/- 0.4 mmol/l, but L(+) lactic acid values remained unchanged under 1 mmol/l. Clear clinical symptoms of indigestion and intoxication characterized by severe inappetence, ruminal stasis and general weakness were also observed. Typical clinical symptoms of disease as well as blood and urine changes in acid-base balance indicated that lactic acid fermentation in the large intestine contributes considerably to the pathogenesis of acute ruminant lactic acidosis.
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PMID:[Impact of lactic acid fermentation in the large intestine on acute lactic acidosis in cattle]. 1147 93


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