Search PubMed⌕ Search

Biomedical subjects

L de Rafael

Publications and source records attributed to L de Rafael.

30 records · Page 2Linked to original sources
PubMed1995

[Decrease of basal levels of gastrin following H. pylori eradication].

UNLABELLED: Hypergastrinemia has long been considered an important factor in the pathophysiology of duodenal ulcer. Moreover, H. pylori infection has been reported in virtually all duodenal ulcers. AIM: To demonstrate the influence of H. pylori eradication on the basal levels of serum gastrin in patients with duodenal ulcer. METHODS: Seventy-six patients with endoscopically proved duodenal ulcer were prospectively studied. At endoscopy three biopsy samples each were taken from duodenal bulb, gastric antrum, corpus and fundus. Two samples from every location were submitted for conventional histological examination and the other for microbiological examination (Gram staining and culture). Endoscopy was repeated one month after the end of therapy, when endoscopy samples were again obtained from the gastric antrum and corpus. Basal levels of gastrin were measured both at initial and repeat endoscopies. Different therapeutic regimes were used: Amoxycillin/Clavulanate plus omeprazole or ranitidine, and triple therapy. RESULTS: H. pylori eradication was associated with a significant histological improvement (p < 0.001), both in antrum and corpus. In those patients with eradicated H. pylori the differences in basal gastrin levels both at diagnosis and after therapy were 45.4 +/- 11 pg/ml and 36.7 +/- 10 pg/ml, respectively; these differences were statistically significant (p < 0.001). When eradication was not achieved differences were not significant. The area under the ROC curve constructed from the different cutoff points for the gastrin decreases was 0.68 (EE 0.06). CONCLUSION: H. pylori eradication in patients with duodenal ulcer was associated with a significant decrease in basal levels of serum gastrin. Although the verification of such a decrease doesn't have an optimal relationship between sensitivity and specificity, it could be an aid as a useful non-invasive method to monitor the efficiency of therapy, both in H. pylori eradication and in the resolution of the associated gastritis. This procedure is also associated with early results and a low cost.

Adult↗
PubMed1995

[Prevalence of Helicobacter pylori infection in gastrectomy and vagotomy].

OBJECTIVE: To report the prevalence of Helicobacter pylori infection in patients undergoing gastrectomy or vagotomy plus pyloroplasty because of peptic ulcer disease. METHODS: Eighty-five patients were studied (mean age = 61 years; 85% males) who had undergone gastric surgery: Billroth I gastrectomy (n = 25), Billroth II (n = 51) and vagotomy plus pyloroplasty (n = 9). During endoscopy biopsy specimens were obtained from fundus and both sides of anastomosis for histological (hematoxylin-eosin) and microbiological (Gram stain and culture) investigations. RESULTS: The overall percentage of Helicobacter pylori infection was 43.6% (Billroth I = 40%; Billroth II = 37%; vagotomy = 89%) and no differences were observed between both types of surgical reconstruction. However, differences were indeed observed (p < 0.01) when comparing percentages of infection between patients undergoing gastrectomy and vagotomy. Among infected gastrectomized patients H. pylori was detected in fundus in 93% of cases, whereas the recovery rate from anastomotic mouth biopsies was only 72% (p < 0.05). CONCLUSIONS: The prevalence of H. pylori infection in gastrectomized patients (Billroth I and II) was low regarding the cause of surgery (peptic ulcer disease), and no differences were observed between both types of surgical reconstruction. The prevalence of infection after vagotomy and pyloroplasty was significantly higher. Among infected gastrectomized patients, H. pylori was detected more frequently in gastric fundus compared with biopsy specimens obtained from the anastomotic mouth.

Adult↗
PubMed1993

[Detection of serum IgG (ELISA) against Helicobacter pylori: relationship with age and gastroduodenal disease].

OBJECTIVE: An attempt was made to investigate the serological response against Helicobacter pylori by using a IgG serum detection technique (ELISA Biometra) to establish a relationship with age and gastroduodenal pathology. The serological response was compared with the microbiologic and histologic studies of biopsy samples from 4 locations in each patient: duodenal bulb, gastric antrum, corpus and fundus. PATIENTS: A total of 309 patients with gastrointestinal symptoms who underwent an upper digestive endoscopy were included. RESULTS: The overall sensitivity of the serological technique (cut-off value 15 U/ml) was 89.3%, the specificity 75.7%, the positive predictive value 96.9% and the negative predictive value 45.4%. The mean titer in patients with a negative microbiology increased with age: 13.5 U/ml, 14-30 years; 10.0 U/ml, 31-50 years; 18.5 U/nl, 51-65 years and 29.2 U/ml, > 65 years. By increasing the cut-off value to 20 and 30 U/ml in the last two age groups, the specificity increased without a significant decrease in the sensitivity. Patients without abnormal findings at endoscopy had mean titers considerably lower (64.7 U/ml) than those with the stomach resected -Billroth I or II- (99.6 U/ml) and those with gastritis, duodenitis and ulcus (86.7-83.1 U/ml), Patients with gastritis but without acute inflammatory activity had mean titers (62.5 U/ml) lower than those observed in patients with active gastritis (p < 0.01) and increased in parallel with the increasing activity of gastritis. In contrast, patients with atrophic gastritis had the lowest mean titers (54 U/ml). CONCLUSIONS: Our results suggest that the cut-off value in the serological technique should be increased according to the patient's age. Moreover, there is a clear relationship between the serum levels of IgG and the activity of gastritis.

Adolescent↗
PubMed1984

Acridine orange stain in the early detection of bacteria in blood cultures.

A total of 1,592 blood cultures without macroscopic signs of bacterial growth in the first 12-24 h of incubation were processed for both acridine orange stain and blind subculture. One hundred and twenty-one (7.6%) blood cultures were positive by either method; of these, 105 (8.68%) were positive by both methods, 11 (9.1%) positive by acridine orange and negative by subculture, and 5 (4.1%) negative by acridine orange and positive by subculture. The difference between the 116 blood cultures positive by acridine orange and the 110 blood cultures positive by subculture was not statistically significant (p greater than 0.1). Gram stain performed on all acridine orange positive cultures failed to reveal bacteria in 14 cases. Acridine orange staining is a sensitive, rapid and reliable method for detecting bacteria in blood cultures early during incubation. The method is inexpensive and easy to perform and can be substituted for blind subcultures.

Acridine Orange↗
PubMed1980

Yersinia enterocolitica Septicemia.

Human Yersinia enterocolitica septicemia is an uncommon condition. Four new cases are reported here and a review is made of 51 others taken from medical literature. Septicemia caused by this microorganism occurs more frequently in the young and in the elderly, and usually involves patients havig previous liver or blood disorders, diabetes mellitus, and other debilitating diseases. Clinically it is indistinguishable from sepsis caused by other organisms of Enterobacteriaceae, but it is important that the clinician bear its existence in mind, since Yersinia enterocolitica strains are usually resistant to beta-lactam antibiotics, whereas they are susceptible to the aminoglycosides and co-trimoxazole, among others. Susceptibilities in the blood isolates from our patients, and in another ten fecal isolates from eight other patients showed the previously described pattern. Our isolates, however, were all susceptible to the new cephalosporins, cefamandole and cefoxitin, and to the experimental ones, HR-756, T-1551, and Ly-127.935.

Adolescent↗