Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0014848 (achalasia)
 2,804 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Achalasia is a disease of the esophagus characterized by incomplete relaxation of the lower esophageal sphincter, resulting in obstruction. Aperistalsis and dilation of the esophageal body occurs later, contributing to the esophageal dysfunction. Gastrointestinal bleeding in achalasia is an infrequent complication usually caused by stasis ulcer, esophageal varices, carcinoma, or pneumatic dilation of the sphincter. We describe here a patient with longstanding achalasia who bled vigorously from a proximal esophageal site that can be identified as arterial bleeding by endoscopy. Subsequent esophageal resection allowed detailed histological and immunohistochemical examination, which revealed a vascular ectasia. This lesion was associated with an unusually rich network of nerve fibers containing calcitonin gene-related peptide. Neuropeptide Y- and substance P-containing fibers were found to be decreased in this lesion as compared with controls. On the other hand vasoactive intestinal peptide- and nitric oxide synthase-containing fibers appeared quantitatively similar to those of controls. Calcitonin gene-related peptide is known to be involved in angiogenesis and may have played a causative role in the development of this lesion. Vascular ectasia may represent a hitherto unreported complication of achalasia.
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PMID:Innervation of an esophageal ectatic submucosal blood vessel in achalasia and a comparison with normals. 752 10

In this study the innervation of the normal human oesophagus was compared with samples taken from 12 patients undergoing Heller's cardiomyotomy for achalasia. The distribution of all nerve fibres in the oesophageal wall was revealed by immunoreactivity to neuron specific enolase and subpopulations of nerve fibres were revealed by immunoreactivity to vasoactive intestinal peptide, neuropeptide Y, enkephalin and substance P. In healthy oesophagus, many nerve fibres immunoreactive for vasoactive intestinal peptide and neuropeptide Y were present in the circular and longitudinal muscle layers of the oesophageal wall and in the cardia of the stomach, whereas fibres immunoreactive for enkephalin and substance P were uncommon. Neuropeptide Y-reactive fibres were commonly seen around blood vessels. In the myenteric plexus cell bodies reactive for vasoactive intestinal peptide and neuropeptide Y were prevalent, as were varicose and non-varicose fibres. In contrast, samples from patients with achalasia revealed few nerve fibres immunoreactive for vasoactive intestinal peptide or neuropeptide Y in either circular or longitudinal muscle, suggesting damage to the inhibitory motor neurons to the muscle layers. Very few fibres were found that were reactive for neuron-specific enolase, indicating that other fibre population (e.g. excitatory cholinergic motor neurons) are also damaged in achalasia. These abnormalities were observed in biopsies from both the constricted and dilated portions of the oesophagus, but the pattern of innervation in the gastric cardia was normal. Myenteric ganglion cells were seen in the oesophagus in only two patients and varicose nerve fibres in the myenteric plexus were uncommon. Neuropeptide Y-reactive perivascular nerve fibres were still found in achalasia as well as non-varicose nerve fibres in the myenteric plexus. These findings indicate damage to all intrinsic neurons in the oesophageal wall in achalasia; however, extrinsic nerve fibres appear to be intact.
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PMID:Distribution of peptide-containing nerve fibres in achalasia of the oesophagus. 874 21

Transcutaneous stimulation (TNS) at esophageal acupuncture points decreases lower esophageal sphincter (LES) pressures in patients with achalasia. We examined the effect of TNS on esophageal motility and vasoactive intestinal peptide (VIP) levels in normal subjects. TNS was applied to either hand or foot (placebo) in 10 volunteers. Esophageal and LES pressures were recorded and blood was drawn for VIP analysis. Hand TNS improved LES relaxation and percent of peristaltic contractions to swallows, and decreased the number of spontaneous contractions. Foot TNS decreased only spontaneous contractions while LES pressures and VIP levels were unchanged. We conclude that a somatovisceral pathway involving the esophagus exists.
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PMID:Effect of transcutaneous nerve stimulation on esophageal function in normal subjects--evidence for a somatovisceral reflex. 887 76

Achalasia cardia is one of the common causes of motor dysphagia. Though the disease was first described more than 300 years ago, exact pathogenesis of this condition still remains enigmatic. Pathophysiologically, achalasia cardia is caused by loss of inhibitory ganglion in the myenteric plexus of the esophagus. In the initial stage, degeneration of inhibitory nerves in the esophagus results in unopposed action of excitatory neurotransmitters such as acetylcholine, resulting in high amplitude non-peristaltic contractions (vigorous achalasia); progressive loss of cholinergic neurons over time results in dilation and low amplitude simultaneous contractions in the esophageal body (classic achalasia). Since the initial description, several studies have attempted to explore initiating agents that may cause the disease, such as viral infection, other environmental factors, autoimmunity, and genetic factors. Though Chagas disease, which mimics achalasia, is caused by an infective agent, available evidence suggests that infection may not be an independent cause of primary achalasia. A genetic basis for achalasia is supported by reports showing occurrence of disease in monozygotic twins, siblings and other first-degree relatives and occurrence in association with other genetic diseases such as Down's syndrome and Parkinson's disease. Polymorphisms in genes encoding for nitric oxide synthase, receptors for vasoactive intestinal peptide, interleukin 23 and the ALADIN gene have been reported. However, studies on larger numbers of patients and controls from different ethnic groups are needed before definite conclusions can be obtained. Currently, the disease is believed to be multi-factorial, with autoimmune mechanisms triggered by infection in a genetically predisposed individual leading to degeneration of inhibitory ganglia in the wall of the esophagus.
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PMID:Pathogenesis of achalasia cardia. 2279 40