Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tedisamil is a new bradycardic agent with an inhibitory action on K+ channels in cardiac muscle, and secondary beneficial effects in experimentally induced cardiac ischemia. In whole-cell clamp studies in enzymatically dispersed, single smooth muscle cells from the guinea-pig portal vein, tedisamil inhibited the delayed rectifier K+ current (determined as the charge transferred through the cell membrane), the mean concentration for half-maximal inhibition being 2.9 microM. In contrast to controls in the absence of drugs or in the presence of the classical K+ channel blockers barium, tetraethylammonium or 4-aminopyridine, the time course of the delayed rectifier K+ current in the presence of tedisamil could no longer be fitted by a single exponential, and signs of an accelerated inactivation by tedisamil were obtained. The slow onset of the response to tedisamil applied to the outside of the vascular myocytes, and the finding that tedisamil applied directly to the cytosol via the pipette was highly effective, suggest an intracellular site of action.
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PMID:Tedisamil inhibits the delayed rectifier K+ current in single smooth muscle cells of the guinea-pig portal vein. 163 Aug 81

To assess ischemic lesions as a factor in obliterative bronchiolitis after lung transplantation, the authors severed the left bronchial arteries of 15 dogs, together with the left stem bronchus, the latter being immediately reanostomosed. They examined the bronchioles at weekly interfals up to three and a half months. On the week chosen each dog was anesthetized, totally heparinized, and exsanguino-perfused with saline. Just after heart arrest, the thoracic aorta was injected with a barium solution until this white medium appeared in the bronchial arteries. The heart-lung blocs were excised en bloc, submitted to soft-tissue x ray, fixed, and then sliced to 1 cm. Corresponding right and left 5-mm-thick samples of these slices were prepared for contact microradiography followed by histologic 5-to-20-micron-thick, stained, correlated specimens. For two weeks the left bronchial arteries remained empty, but there was no necrosis or edema. Between two and four weeks barium solution appeared in the bronchial arteries, and the bronchiolar epithelium had become multistratified. Later the left bronchiangiogram became similar to the right, but there were more folds of the mucosa and a little submucosal fibrosis. These studies provide proof that no significant ischemic lesions occurred during repermeation of the bronchiolar vascular bed. Ischemia, if existent, is not a significant factor in obliterative bronchiolitis.
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PMID:Bronchiolar morphology after systemic arterial interruption. 170 Aug 91

This elderly male with a long history of alcohol abuse presented with an acute pleural trauma and hemopneumothorax, which may have served as the precipitating medical illness for cecal volvulus. He subsequently developed bacterial peritonitis as a complication of his bowel obstruction. It is probable that his pleural cavity was seeded hematogenously via a bacteremia from his peritonitis, thus accounting for the empyema with species typical of bowel flora. Cecal bascule is a type of cecal volvulus that causes intestinal obstruction. Diagnosis is difficult, but a delay in recognition may result in intestinal ischemia, perforation, sepsis, and even death. Cecal ischemia or gangrene cannot always be determined based on physical examination or laboratory findings. Plain films of the abdomen may be helpful, and barium enema has been advocated by some authors. However, laparotomy is often necessary for definitive diagnosis and therapy. While cecal volvulus has not been reported to occur frequently in the elderly, the relatively common occurrence of anatomic predisposition in addition to the widespread use of respirators and the increasing age and number of medical illnesses of our population make it possible that cecal volvulus will be seen with increasing frequency in the future.
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PMID:Cecal bascule: an overlooked diagnosis in the elderly. 172 51

Because plain films are usually normal or nonspecific in both colonic and acute mesenteric ischemia, they are not diagnostically helpful. The barium enema is the most useful radiographic examination in the diagnosis of colonic ischemia, and a double-contrast study will show abnormalities in almost all cases. Findings specific for colonic ischemia characteristically change with time. Thumbprinting is the most diagnostic finding; it is seen early in the course of the disease and usually resolves or is replaced within 1 or 2 weeks by an acute ulcerating colitis pattern. The latter may heal over months or go on to stricture formation or a persistent colitis. Nonspecific abnormalities can also be identified on CT and ultrasound, but the incidence of the findings with colonic ischemia is not known. Plain film findings occur late in the course of acute mesenteric ischemia and thus cannot be relied on for the diagnosis, although they may be useful in excluding other conditions. When acute mesenteric ischemia is suspected, angiography should be performed, but CT, ultrasound, and, perhaps, MR imaging may contribute to the diagnosis.
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PMID:Radiology in intestinal ischemia. Plain film, contrast, and other imaging studies. 173 79

Gastric ulceration after fundoplication for gastroesophageal reflux is relatively uncommon, occurring in 1% to 3% of cases. During the period 1974 to 1979, approximately 100 modified Belsey fundoplications were performed at McMaster University Medical Centre. In four patients gastric ulceration developed after the surgery. In all cases the ulcers were located in the proximal stomach, an unusual site. Published reports of gastric ulceration after fundoplication were reviewed, special attention being given to the cause. The authors conclude that local ischemia and mechanical trauma are important in the development of ulceration, which can occur as early as one week after fundoplication. The detection of ulcers requires awareness of the condition and special attention to the symptoms. Because the gastric anatomy is altered by the fundal wrap, the area can be visualized more easily by double-contrast barium studies than by endoscopy.
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PMID:Gastric ulceration after fundoplication. 173 87

A case of urticarial vasculitis syndrome is described in which the gastrointestinal disease was the main clinical manifestation. The gastroduodenal barium meal demonstrated signs compatible with intestinal ischemia which reversed upon medical treatment. The colonoscopy with biopsy showed changes compatible with unspecific colitis. The role of reversible acute vasculitis as a pathogenic factor implicated in the gastrointestinal manifestations in this entity is discussed. Although the response to treatment with corticoids and cochicine was not constant, there was good response to dapsone in successive relapses of the disease. Despite some antibodies becoming positive during the third year of follow up, the patient did not fulfill the clinical criteria for the diagnosis of systemic lupus erythematosus.
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PMID:[Gastrointestinal involvement and the response to dapsone in a case of the urticarial vasculitis syndrome]. 177 Aug 22

The barium enema is a safe and accurate diagnostic study of the colon but, in rare cases, complications may result. Many of these can be prevented by proper equipment and careful attention to technique. When a complication does occur, prompt recognition and management is vital in decreasing morbidity and mortality. Perforation of the bowel is the most frequent serious complication, occurring in approximately 0.02% to 0.04% of patients. Rarely the colon may burst due to excessive transmural pressure alone. However, a colon weakened by iatrogenic trauma or disease is more likely to perforate during an enema than is a normal healthy bowel. Injury to the rectal mucosa or anal canal due to the enema tip or retention balloon is probably the most common traumatic cause of barium enema perforation. Inflation of a retention balloon within a stricture, neoplasm, inflamed rectum, or colostomy stoma is particularly hazardous. Recent deep biopsy or polypectomy with electrocautery makes the bowel more vulnerable to rupture. The tensile strength of the bowel wall is impaired in elderly patients, patients receiving long-term steroid therapy, and in disease states including neoplasm, diverticulitis, inflammatory bowel disease, and ischemia. Intraperitoneal perforation leads to a severe, acute peritonitis with intravascular volume depletion. The ensuing shock may be rapidly fatal. Prompt fluid replacement and laparotomy are essential. If the patient survives the initial shock and sepsis, later complications caused by dense intraperitoneal adhesions may develop. Extraperitoneal perforation is usually less catastrophic but may result in pain, sepsis, cellulitis, abscess, rectal stricture, or fistula. Intramural extravasation often forms a persistent submucosal barium granuloma which may ulcerate or be mistaken for a neoplasm. The most dramatic complication of barium enema is venous intravasation of barium. Fortunately, this is quite rare as it may be immediately lethal. Most cases have been attributed to trauma from the enema tip or retention balloon, mucosal inflammation, or misplacement of the tip in the vagina. Bacteremia has been found in as many as 23% of patients following barium enema and, in rare cases, may cause symptomatic septicemia. Other less common complications include barium impaction, water intoxication, allergic reactions, and cardiac arrhythmias. Preparatory laxatives and cleansing enemas have been implicated in some instances of dehydration, rectal trauma, water intoxication, and perforation. Careful review of the indications for examination, previous radiographs, and clinical history will identify many of the patients at greater risk for complications so that appropriate precautions may be observed.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Recognition and prevention of barium enema complications. 188 35

Review of the English literature revealed 21 cases describing abnormalities on barium enema secondary to amyloidosis of the colon. These cases were categorized as to frequency of specific barium enema findings and distribution within the colon. The most common radiologic findings were luminal narrowing (11 of 21), loss of haustrations (10 of 21), thickened mucosal folds (8 of 21), mucosal nodularity (8 of 21), and ulceration (6 of 21). The most frequent locations of disease within the colon were the descending and rectosigmoid portions (13 of 21). We present a case of primary amyloidosis that demonstrates the findings of bowel wall thickening and luminal narrowing on double-contrast barium enema and computed tomography (CT). Pathologic examination in our case, in addition to similar observations from the literature, suggests that at least a part of the radiologic changes of colonic amyloid can be attributed to bowel ischemia.
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PMID:Amyloidosis of the colon presenting as ischemic colitis: a case report and review of the literature. 201 25

Nonthrombotic occlusion or stenosis of the mesenteric veins is a rare cause of intestinal ischemia that usually occurs in association with systemic vasculitis. The current report includes four male patients with segmental ischemic colitis caused by idiopathic myointimal hyperplasia in the small mesenteric veins and their intramural branches; neither vasculitis nor arterial involvement were present. Three of the four patients were less than or equal to 38 years of age; the fourth was 67. All four patients were previously healthy and had no history of drug use of any kind. Clinical findings included abdominal pain, diarrhea, bloody stools, and colonic strictures discovered by barium enema. The intima of the mesenteric and intestinal mural veins was focally thickened by a marked increase in cells and matrix between the endothelium and internal elastic lamina, whereas the vessel walls external to the thickened intima appeared normal. Histochemistry and immunoreactivity with antibodies to muscle-specific actins (HHF-35) disclosed that the intimal thickening was caused by proliferation of smooth muscle cells in a proteoglycan matrix. All patients recovered completely after segmental resection of the ischemic portion of the colon and had no recurrence of intestinal symptoms on follow-up of up to 7 years. These unusual venous lesions do not appear to have been previously described; their etiology and pathogenesis remain unknown.
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PMID:Idiopathic myointimal hyperplasia of mesenteric veins. 206 29

Flecainide acetate is a new antiarrhythmic drug which suppresses different kinds of experimental arrhythmias. We studied the efficacy of flecainide acetate on reperfusion- and barium-induced ventricular tachyarrhythmias in the isolated perfused rat heart by monitoring heart rate, coronary flow rate, left ventricular systolic pressure, dp/dtmax, and the voltage of the epicardial electrogram. Seventy-five male rats were randomized into 5 groups. In group I, after a 15 min period of stabilization, hearts were perfused by ischemic perfusion and then reperfused. In group II, flecainide acetate (10(-6) M) was given after stabilization and before ischaemic perfusion. In group III, barium chloride (10(-3) M) was given after stabilization. In group IV, flecainide acetate was given after stabilization and before barium chloride administration. In group V, acetylcholine chloride (10(-6) M) was given after stabilization and before barium chloride administration. In group I, we noted during ischemia a reduction in heart rate, coronary flow rate, left ventricular systolic pressure and dp/dtmax and an increase in the voltage of the epicardial electrogram. In group II, after administration of flecainide acetate, we observed a reduction in heart rate, left ventricular systolic pressure and dp/dtmax; during the ischaemic period there was no difference in these parameters with respect to group I. Reperfusion induced ventricular arrhythmias in 12 out of 15 hearts in group I and in only 3 out of 15 in group II (p less than 0.005). Barium induced ventricular arrhythmias in the 15 hearts studied in group III as well as in group IV. On the contrary, acetylcholine chloride in group V prevented the occurrence of barium-induced ventricular arrhythmias (p less than 0.005 vs group III and IV). Thus, flecainide acetate is able to reduce reperfusion-induced ventricular arrhythmias, but is unable to reduce barium-induced ventricular arrhythmias, presumably because of a different mechanism of these two types of arrhythmias.
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PMID:Effect of flecainide acetate on reperfusion- and barium-induced ventricular tachyarrhythmias in the isolated perfused rat heart. 212 50


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