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Biomedical subjects

S Anuras

Publications and source records attributed to S Anuras.

At least 19 recordsLinked to original sources

Effects of prostaglandins E2 and F2 alpha on electromyogram of cat colon in vitro.

Prostaglandins cause diarrhea, and their production by the gut increases in diarrheal states. We studied the effects of PGF2 alpha and PGE2 on the electromyogram recorded from the cat colon in vitro to determine if these prostaglandins might produce electromyographic changes similar to those seen in diarrheal states. PGF2 alpha decreased slow wave frequency and uncoupled slow wave propagation in the proximal colon. It increased the frequency of migrating spike bursts. PGE2 had no effect on slow waves, but increased the frequency of the migrating spike burst. PGF2 alpha produced electromyographic changes similar to those recorded from the colon of cats with spontaneous diarrhea or after exposure to diarrhea-producing agents such as ricinoleate or quinidine. Some diarrhea-producing agents are likely to act by increasing prostaglandin production.

Animals↗

Neuromuscular disease of the gastrointestinal tract.

Gastrointestinal motility is the function of gastrointestinal smooth muscle. It is controlled by both the intrinsic and extrinsic nerves of the gastrointestinal tract and, to a lesser degree, the gastrointestinal hormones. Therefore, any abnormality of the above factors, theoretically, can cause gastrointestinal dysmotility. In a clinical situation, commonly seen is gastrointestinal dysmotility caused by either smooth muscle or intrinsic and extrinsic nerves dysfunction. Diseases that cause smooth muscle dysfunction include familial visceral myopathies, nonfamilial visceral myopathies, collagen disease, muscular dystrophies, amyloidosis, thyroid disease, and so on. Diseases that cause enteric nerve dysfunction include familial visceral neuropathies, nonfamilial visceral neuropathies, diabetes mellitus, Chagas' disease, ganglioneuromatosis of the intestine, visceral neuropathy of carcinomatosis, Parkinson's disease, and so on. The patients with neuromuscular disease of the gastrointestinal tract have a wide range of clinical manifestations regardless of the underlying cause. At one end of the spectrum, the patients may be asymptomatic, and at the other end of the spectrum, the patients may have functional obstruction of the gastrointestinal tract. Plain abdominal x-rays, upper gastrointestinal (UGI) and small bowel x-rays, enteroclysis, barium enema, and manometric studies are useful for the work-up of these patients. Enteroclysis is especially helpful in ruling out mechanical obstruction of the small intestine in patients with chronic intestinal pseudo-obstruction. Treatment is mainly symptomatic and supportive. There is no effective drug to improve gastrointestinal motility. Surgery may be helpful in selected cases of severe gastrointestinal dysmotility.

Gastrointestinal Diseases↗

Right atrial myxoma with a nonembolic intestinal manifestation.

A 5-year-old male with right atrial myxoma without interatrial communication who presented with abdominal pain, vomiting, fever, and guaiac positive stool is reported. He was later found to have ischemia of a jejunal segment necessitating segmental resection. Although his symptoms persisted postoperatively, surgical removal of a right atrial myxoma was followed by complete resolution of his intestinal symptoms. We demonstrated that the mesenteric vasculitis was of nonembolic origin, and we speculate autoimmune arteritis as a possible mechanism.

Child, Preschool↗

Intestinal pseudo-obstruction syndrome.

Intestinal pseudo-obstruction is a syndrome of many causes. Attempts must be made to determine the cause and the extent of the involvement of the gastrointestinal tract in each patient, because they will dictate the method of treatment for that patient. Family history must be taken from all primary chronic intestinal pseudo-obstruction patients. If it is positive, genetic counseling and proper medical management can be given to newly identified cases in the family.

Colonic Diseases↗

Changes in colorectal function in patients with chronic colonic pseudoobstruction.

Motility studies of the lower bowel, radiology to exclude other gastrointestinal involvement, and rectal biopsies were carried out in 11 patients, age 21-60 years, with isolated chronic colonic pseudoobstruction. Repeated plain abdominal x-rays during symptomatic periods revealed massive gaseous colonic distension in all. Seven patients had the primary form while four patients had an underlying disease which could have been responsible for the chronic colonic pseudoobstruction. Lower bowel motility was decreased in patients with the primary form. Rectal wall elasticity was increased in both the primary and secondary form. Some of the abnormalities measured may suggest myogenic abnormalities of the sigmoid or rectal wall. No specific neural or muscular morphologic defect was identified in colonic transmural sections in eight patients except in the patient with Hirschsprung's disease. Five of seven patients with primary colonic pseudoobstruction achieved symptomatic relief only after subtotal colectomy and ileoproctostomy.

Adult↗

Intestinal motility disorders of infants and children: classification, clinical manifestations and roentgenology.

Diseases affecting intestinal motility in the pediatric age group are reviewed as to pathophysiology, clinical manifestations, and imaging investigation. Acute disease includes classical paralytic ileus (which has unique causes and manifestations in the infant) and acute regional bowel paralysis. Perinatal motility disorders consist of a group of related clinical syndromes which have in common functional intestinal obstruction. Chronic motility disorders are divided into those diseases in which the principal abnormality is in the bowel or those entities where the gut is affected as part of a generalized disease. Regional muscle disease includes Hirschsprung's disease and allied disorders. Some recognized causes of chronic functional obstruction of bowel include megacystis-microcolon-intestinal hypoperistalsis syndrome, rare enzymatic disorders, several discrete forms of chronic intestinal pseudoobstruction, as well as some less well-defined entities. Clinical and pathologic nature and methods of imaging investigation of these entities are considered.

Abdominal Muscles↗

Chronic intestinal pseudoobstruction in young children.

We studied 8 young children (4 boys and 4 girls) with chronic intestinal pseudoobstruction. Intestinal pseudoobstruction, recurrent urinary tract infections, and dysuria occurred between the ages of a few weeks to 5 yr old. All had marked dilatation of the entire gastrointestinal tract distal to the esophagus, and megacystis. Conventional pathologic examinations of the full-thickness specimens of the gastrointestinal tract were normal in 5 and abnormal in 2 patients. The abnormalities included increased fibrosis and lipofuscin pigment in the smooth muscle cells. Myenteric plexus examination, using the Smith's method in 2 patients, was normal. Biopsy specimens from urinary bladders examined in 3 patients revealed separation of individual smooth muscle cells by collagen fibers. Intestinal manometric studies performed in 3 patients showed only weak and infrequent contractions during fasting and after feeding. Severe and extensive dysfunction of the gastrointestinal and urinary tracts with relatively normal histologic appearance are typical for these children.

Abdomen↗

A familial visceral myopathy with dilatation of the entire gastrointestinal tract.

We are reporting a new kindred in which familial visceral myopathy was identified in four siblings. There was no other symptomatic case identified in this 75-member, four-generation family, suggesting an autosomal recessive inheritance. All patients had recurrent symptoms of intestinal obstruction, and 3 died from malnutrition. Gastrointestinal lesions showed marked dilatation of the entire digestive tract from the esophagus to the rectum, which is different from other types of familial visceral myopathies. Microscopic examination of the gastrointestinal smooth muscle showed degeneration and increased fibrosis indistinguishable from other types of familial visceral myopathy.

Adult↗

The colon in the pseudoobstructive syndrome.

Colonic pseudoobstruction can occur as part of a generalized chronic intestinal pseudoobstruction syndrome or as an isolated entity. Isolated colonic pseudoobstruction can occur in two unrelated forms: the acute and chronic forms. Acute colonic pseudoobstruction is frequently a hospital-acquired disease that arises as a complication of other illnesses. The syndrome must be recognized and treated with early colonoscopic decompression to prevent cecal or colonic perforation. Chronic colonic pseudoobstruction is a syndrome of many causes. The prognosis of patients with chronic colonic pseudoobstruction is much better than that of generalized chronic intestinal pseudoobstruction, because the patients become asymptomatic with appropriate operations. The pathogenesis of acute colonic pseudoobstruction and several types of chronic colonic pseudoobstruction is not known. Further investigations should include bacteriologic study, histopathologic studies (examinations of smooth muscle and myenteric plexus), and examination of extrinsic nerves of the colon. With these approaches, a better understanding of the pathogenesis of these syndromes will be achieved.

Colonic Diseases↗

Effect of substance P on opossum duodenal smooth muscle.

Opossum duodenum was cut into strips measuring 2.0 X 15.0 mm. Strips cut along the oral-caudal axis were called longitudinal strips, while those cut 90 degrees to that axis were called circular strips. Each strip was placed in a heated, oxygenated organ bath and attached to a force-displacement transducer. Substance P produced tonic contraction in longitudinal strips and tonic and phasic contraction in circular strips. The ED50 for longitudinal and circular muscle was 1.9 X 10(-7) M and 2.8 X 10(-7) M, respectively. Longitudinal muscle was 1.3 times more sensitive to substance P than circular muscle. Phenoxybenzamine, atropine, curare, propranolol, haloperidol, and tetrodotoxin had no effect on the substance P-produced contractions in circular and longitudinal muscle. Trifluoperazine (10(-5) and 10(-4) M), D600 (10(-7) M), and nifedipine (10(-8) and 10(-7] inhibited both tonic and phasic contraction in circular and longitudinal strips. These studies suggest that substance P acts on both muscle layers at a site located at the muscle cell and that it produces tonic and phasic contraction through similar calcium-activating pathways.

Animals↗

Familial visceral myopathy: the role of surgery.

Familial visceral myopathy is a form of chronic intestinal pseudoobstruction in which fibrosis of the smooth muscle of the alimentary tract causes protean symptoms of disordered visceral motility. Based on our 8 year observation of six members of one family with familial visceral myopathy and review of the few well-documented case reports of this disease, we have confirmed a role for surgeons in tissue diagnosis, case identification, and palliation of incapacitating symptoms of familial visceral myopathy after obtaining dynamic radiographic assessment of the entire alimentary canal. Because the duodenum and colon are the usual sources of major dysmotility symptoms, patients incapacitated by duodenal or colonic pseudoobstruction may benefit from bypass or resective operations.

Adult↗

Effects of age and sex on anorectal manometry.

We studied rectal and anal function in 18 healthy elderly and 18 healthy young adults using intraluminal pressure transducers and a rectal balloon. Both age groups consisted of nine females and nine males. Age did not affect anal length, highest anal resting tone, anal pullthrough pressures obtained during rest and voluntary squeeze, threshold of the rectosphincteric reflex (RSR), amplitude of RSR with 60 ml rectal distension, threshold of sensation, critical volume, and rectal wall elasticity. Sex did not affect anal length, threshold of RSR, amplitude of RSR with 60 ml rectal distension, the critical volume and rectal wall elasticity. But the highest anal resting tone, anal pullthrough pressures obtained during rest and voluntary squeeze, and threshold of rectal sensation were significantly higher in the males than in the females. While aging did not affect anal and rectal function, sex did. Males achieved higher anal canal pressures. Therefore, statistical comparison between different groups of subjects is valid only if the groups are matched for sex.

Adult↗

Elevated ANA titers in patients with severely abnormal gastrointestinal motility.

We studied a group of six patients with clinical, radiological, and/or manometric features of severely abnormal gastrointestinal motility. Symptoms suggestive of esophageal, small bowel, or colonic involvement were present from 1 1/2 to 40 years. All patients had elevated antinuclear antibody (ANA) titers. None had clinical or radiographic features suggestive of progressive systemic sclerosis or other connective tissue diseases. Two patients had pathologic examinations of intestinal specimens, and these did not show changes suggestive of progressive systemic sclerosis. We conclude that patients with severe gastrointestinal motility disorders can have elevated ANA titers without features of progressive systemic sclerosis or other connective tissue diseases.

Aged↗

Urological manifestations of patients with visceral myopathy.

Of 10 patients with familial or nonfamilial visceral myopathy studied for urological manifestations only 3 had symptoms of urinary retention. Excretory urography revealed megacystis in all 3 symptomatic patients, while the 7 asymptomatic patients had normal-sized bladders. Cystometrograms performed in 4 asymptomatic patients also were normal. Bladder tissue from 5 patients was studied. Of 3 autopsy cystectomy specimens 2 were dilated severely and thin-walled without trabeculations or diverticula suggestive of mechanical obstruction. Microscopic sections showed segmental intrafascicular fibrosis in 4 patients, which was associated with elastosis in 3. Electron microscopy of leiomyocytes in abnormal fascicles revealed myofilament disorganization, lipid accumulation and increased numbers of cytoplasmic organelles. We conclude that pathological changes in the bladder occur commonly but urinary symptoms occur in less than half of the patients with visceral myopathy available for study. An abnormal excretory urogram was seen in only patients who had symptoms suggestive of lower urinary tract dysfunction.

Adolescent↗

Sigmoidal and rectal motility in healthy elderly.

Motility in the sigmoid, rectosigmoid, and rectum was studied before, during, and after a 900-kcal meal in 18 healthy elderly and 18 healthy young adults. Three intraluminal pressure transducers spaced 5 cm apart were used for the recording. No differences existed in the percentage activities and the surface areas under the contraction curves (SA) for the corresponding measurements during fasting, during eating, and after consumption of a meal in the elderly and young adults (P greater than 0.1). A 900-kcal meal significantly increased percentage activity and SA in all three recording areas in both the elderly and young adults (P less than 0.02). Percentage activity and SA returned to fasting levels immediately after consumption of the meal. Percentage activity and SA were highest 15 cm above the anal verge in both elderly and young adults. These findings suggest that age and gender do not affect sigmoidal, rectosigmoidal, and rectal motility.

Adult↗