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Biomedical subjects

A Tomé

Publications and source records attributed to A Tomé.

12 recordsLinked to original sources
PubMed2000

Differential contribution of syntaxin 1 and SNAP-25 to secretion in noradrenergic and adrenergic chromaffin cells.

We used botulinum neurotoxins (BoNT) to examine whether differences in the secretory activity of noradrenergic and adrenergic chromaffin cells are related to differences in the exocytotic machinery of these two types of bovine adrenal medulla cells. Cleavage of syntaxin and SNAP-25 by BoNT/C1 decreased in a dose-dependent way the release of both noradrenaline and adrenaline, but noradrenaline release was more sensitive to BoNT/C1. Cleavage of SNAP-25 by BoNT/A also had a larger inhibitory effect on noradrenaline release than on adrenaline release. Neither BoNT/C1 nor BoNT/A affected the intracellular Ca2+ responses induced by K+-depolarisation, and the extent of the inhibition of K+-evoked catecholamine release by selective blockers of voltage-gated Ca2+ channels was not affected by BoNT/C1. Therefore, our data do not support the hypothesis of a regulatory effect of syntaxin or SNAP-25 on the activity of Ca2+ channels. The lower sensitivity of adrenaline release to BoNT was not due to a reduced ability of the toxins to enter or to cleave their protein targets in adrenergic cells, since immunoblot analysis showed the cleavage of a larger fraction of syntaxin 1A in adrenergic cells, as compared to the cleavage in noradrenergic cells. The immunoblot analysis also showed larger amounts of syntaxin 1A in noradrenergic chromaffin cells than in adrenergic cells. Thus, in spite of a greater cleavage of syntaxin 1A in adrenergic cells by BoNT/C1, adrenaline release was less sensitive to BoNT/C1, suggesting that the release process in noradrenergic cells might be more dependent on syntaxin 1A and SNAP-25, as compared to adrenergic cells.

Adrenal Glands↗
PubMed1997

[Collagenous colitis: presentation of 12 cases].

Collagenous colitis (CC) is a cause of chronic aqueous diarrhea with normal radiologic study and endoscopic appearance of the colonic mucosa. Histologically, it is defined by the presence of a thickened subepithelial collagenous band and inflammatory changes of the mucosa. The cause of CC is currently unknown, although several mechanisms have been proposed, such as an inflammatory, autoimmune, origin, disregulation in collagen synthesis, plasma vasculosis and a possible role of bacterial or drug toxins. The clinicopathological data of 12 patients (9 females and 3 males) with a mean age of 52.4 years diagnosed by histologic criteria are presented. Aqueous diarrhea was observed in all the patients with a mean number of 5.4 stools/day during a time period between 3 weeks and 10 years (mean, 14.7 months). In a 6 patients allergies and/or associated diseases, mainly rheumatologic diseases were found. Laboratory and endoscopic data were normal or unspecific, with colon biopsy being carried out in all the patients. Several treatments were tested with good response with sulphasalazine derivatives, corticoids, antibiotics, and mebeverine, with no solution to the diarrhea in 2 patients. A review of the literature is also provided.

Adult↗
PubMed1996

[Splenic infarction].

A 53-year-old male suffered splenic infarction etiologically related to atrial fibrillation and non-obstructive hypertrophic cardiomyopathy. The main clinical manifestations were a one-month history of epigastric and left upper quadrant pain, with tenderness to palpation in the later zone. Laboratory tests revealed a slight leucocytosis (14.700) with left shift and a marked increase in LDH concentration (945 IU). Abdominal CAT and arteriography established the diagnosis, Echography proved normal. Patient evolution was satisfactory with conservative medical treatment. We conclude that splenic infarction should be considered in all cases of acute or chronic pain in the left hypochondrium. The diagnosis is established by CAT, arteriography and hepatosplenic gammagraphy. Medical management is initially advocated, surgery being reserved for those cases involving complications or in which diagnosis is not clear. Emphasis is placed on the main etiological, clinical, diagnostic and management characteristics of splenic infarction.

Angiography↗
PubMed1995

[Does the antisecretory agent used affect the evolution of upper digestive hemorrhage?].

OBJECTIVE: To investigate whether omeprazole has improved morbidity-mortality among patients with upper gastrointestinal bleeding of non-variceal origin in comparison with ranitidine. MATERIAL AND METHODS: Prospective, randomized and open study. We study 519 consecutive patients admitted to our Service between June 1991 and January 1993 for upper gastrointestinal bleeding of peptic origin, dividing the patients into two randomized groups that were homogeneous in terms of age, sex, previous history of gastric disease and upper gastrointestinal bleeding, intake of non-steroidal antiinflammatory drugs, and the severity of bleeding on admittance. Thus, Group A consisted of 252 patients treated immediately upon arrival at the emergency ward with 50 mg intravenous ranitidine, followed by a further 50 mg every 6 hours. Group B in turn consisted of 267 patients initially given a bolus dose of 80 mg omeprazole intravenously, followed by an additional 40 mg every 8 hours for 48 hours. Forty mg were subsequently administered every 12 hours until hospital discharge. Endoscopy was performed in all cases within the first 24 hours following admittance, those patients with active upper gastrointestinal bleeding resulted from Forrest-type ulcer of subjected to endoscopic sclerotherapy were excluded. RESULTS: Duodenal ulcer was the most common cause of bleeding, followed by gastric ulcer and acute lesions of the mucosa. Emphasis should be placed on the high incidence of previous non-steroidal antiinflammatory drug intake in our series (54.5%). We encountered no statistically significant differences between the two groups on comparing bleeding stigmata, transfusion requirements, recurrences, emergency surgery, the duration of hospital stay, and mortality. CONCLUSIONS: Both drugs were found to possess a similar efficacy in treating upper gastrointestinal bleeding of peptic origin.

Adolescent↗
PubMed1993

[Diagnostic value of aspiration cytology with ERCP].

ERCP is of great value in diagnosing malignant pathology of the biliopancreatic duct system. However, the ERCP endoscopic characteristics in malignant stenosis often lack specificity and are difficult to differentiate from those of chronic pancreatitis. In these cases histological confirmation is essential to diagnosis. With the aim of increasing the diagnostic possibilities of ERCP in pancreatic cancer--particularly when associated with chronic pancreatitis--we performed aspiration cytology of pancreatic juice obtained via endoscopic cannulation of the main pancreatic duct using ERCP in 102 patients with suspected periampullar pathology, chronic pancreatitis and/or pancreatic cancer. The diagnostic sensitivity of cytology for pancreatic malignancy was 33.3%, versus 60% for cancer of Vater's papilla. Specificity was 100% in both cancers. We observed no false positive results or complications. On combining both techniques, i.e., ERCP and cytology of the pancreatic juice, sensitivity increased to 100% for pancreatic malignancy, 77.7% for chronic pancreatitis (characteristic ERCP radiographic images and absence of neoplastic cells) and 100% in the case of ampullomas. Difficulties in the differential diagnosis between advanced chronic pancreatitis and pancreatic cancer persist with ERCP alone. In such cases aspiration cytology may secure a definitive diagnosis--particularly when neoplastic cells are demonstrated (Class IV).

Adult↗
PubMed1993

[Long-term results of endoscopic sphincterotomy].

A review is made of the results of long-term endoscopic sphincterotomy. We studied 81 endoscopic sphincterotomies performed between 1980 and 1985. The technique performed, its indications and immediate complications were evaluated, along with the follow-up carried out in these patients (minimum 6 years). In view of the results obtained, the patients were classified as asymptomatic or symptomatic. Thus, immediate complications (21.9%) were all minor, with the exception of one case (1.2%) of severe complication due to acute pancreatitis. One death was recorded three days after sphincterotomy, corresponding to an elderly patient with in situ gallbladder as a consequence of biliary sepsis. In turn, 91.4% of the patients followed-up at long term remained asymptomatic. The overall results show the method to be effective, with few either immediate or long-term complications.

Adult↗
PubMed1990

Segmental tuberculosis of the colon diagnosed by colonoscopy.

We describe the case of a woman with rectorrhagia and rectal tenesmus. Colonoscopy revealed a 3-4 cm-long ulcerated lesion with a reduced colon lumen 35 cm from the anus, and multiple biopsies were obtained from the ulcerated region, but histopathology was non-specific. Biopsy culture was positive for M. tuberculosis. Anti-tuberculous chemotherapy was initiated on the diagnosis of segmental tuberculosis of the colon. Subsequent evolution was favorable, both clinically and endoscopically. Emphasis is placed on the importance of colonoscopy and biopsy in the diagnosis of tuberculosis of the colon.

Aged↗
PubMed1990

[Physical exercise and gastric acid secretion].

The effects of physical exercise on the basal acid secretion of the stomach has been investigated in 10 healthy individuals and 16 hypersecretors with duodenal ulcer. The gastric basal secretion was collected during 3 hours; during the first hour the patient was at rest, during the second he realized a training exercise, according to Roskamm's formula, and in the third was at rest. While normal subjects showed a significative reduction of the acid secretion during the period of exercise, in the hypersecretory patients with ulcer the acid secretion increased significantly during exercise, from 4.25 +/- 1.52 mEq/h to 7.79 +/- 3.49 mEq/h; these figures reverted to normal values (5.45 +/- 2.21) during the recovery period. We comment the potential mechanisms of these differences in both groups of patients.

Adult↗
PubMed1989

Hypertrophic pyloric stenosis in the adult.

In view of the low incidence of hypertrophic pyloric stenosis, we present a case of this pathology in a male aged 74. Stenosis was of the diffuse type, associated with gastric ulcer and chronic atrophic gastritis. The patient was admitted to our Service with upper digestive tract hemorrhage after deterioration of the ulcer.

Aged↗
PubMedDate not supplied

[Non-aneurysmatic aortic dysphagia].

Esophageal compression by a vascular structure is a rare cause of dysphagia, the aberrant right subclavian artery being the most common congenital abnormality. Aortica dysphagia is usually observed in the elderly, especially in hypertensive women with cardiopathy and degenerative osteopathy. We report a 73-year-old woman with dysphagia, caused by a non-aneurysmatic aortic elongation, who presented progressive dysphagia, which ended in aphagia associated with heart failure. The diagnostic approach to these patients is discussed. The patient received cinitapride and, following treatment for heart failure, remains asymptomatic after a 3-year follow-up period, although manometric alterations persist.

Aged↗
PubMedDate not supplied

[Cluster headache].

We present a review of 60 cases of cluster headache. Most patients were males, ranging from 19 to 65 years of age at the time of the first visit. Headaches consisted of short-lasting (from 15 to 210 minutes), intense, unilateral pain attacks, most frequently in the periorbital area, with ipsilateral autonomic signs (rhinorrhea, ptosis, tearing and conjunctival injection). Between attacks, patients were completely free of pain. The attacks occurred in bouts lasting 1 to 6 months, in which patients had daily headaches (one to three times a day). Headaches responded well to oxygen or ergotamine. Prophylactic therapy in most cases consisted of verapamil, also with a good response. We present this review in order to draw attention to this relatively rare form of headache with a specific therapy.

Adolescent↗