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Biomedical subjects

E N Mendes

Publications and source records attributed to E N Mendes.

At least 37 records · Page 2Linked to original sources
PubMed1994

Effect of Helicobacter pylori eradication on G-cell and D-cell density in children.

Helicobacter pylori infection is associated with abnormalities in serum gastrin concentration, antral gastrin and somatostatin content, and D-cell density in adults. We have studied the effects of H pylori infection in children. We studied 13 children positive for H pylori and 7 negative children. The median antral somatostatin content was significantly lower in the positive than in the negative group (0.69 [range 0.35-0.91] vs 1.31 [0.73-1.67] ng/mg, p = 0.007). Both antral and serum gastrin concentrations were significantly higher in the positive group (30.1 [15.3-83.6] vs 14.8 [13.8-28.8] ng/mg, p = 0.008; and 89.9 [59.4-313.2] vs 29.5 [13.9-71.1] pg/mL, p = 0.006). Treatment to eradicate H pylori was successful in 11 of the 13 positive patients. With eradication antral somatostatin increased to within the normal range (by a median of 0.41 [0.21-0.86] ng/mg to 1.10 [0.81-1.55] ng/mg, p = 0.016). Serum and antral gastrin decreased (by 37.1 [5.5-265.2] pg/mL to 52.8 [21.4-267.5] ng/mg, p = 0.001; and by 8.0 [2.0-47.2] ng/mg to 22.1 [10.9-37.5] ng/mg, p = 0.001). Eradication of H pylori also significantly increased antral D-cell density (8 [5-22] to 15 [9-22] cells per mm, p = 0.031) and decreased G-cell density (138 [89-161] to 88 [33-121] cells per mm, p = 0.016). The hypergastrinaemia in children positive for H pylori may be due to a deficiency of antral somatostatin, which inhibits gastrin synthesis and release.

Adolescent↗
PubMed1994

Seroprevalence of Helicobacter pylori infection in children of low socioeconomic level in Belo Horizonte, Brazil.

OBJECTIVE: To study the epidemiology of Helicobacter pylori infection in children of low socioeconomic level in Belo Horizonte, Brazil. METHODS: Serum samples were collected from 249 children (134 boys, 115 girls, mean age 6.4 yr, range 1 month to 18 yr) at an outpatient clinic of the University Hospital/UFMG, Belo Horizonte, Brazil. Information obtained included age, gender, nutritional status, family income, domestic crowding, sewage, and water supply. H. pylori infection was identified by means of an indirect immunofluorescence assay (sensitivity, 94.3% and specificity, 100.0% in children) which detects the presence of IgG against H. pylori. RESULTS: Ninety-seven percent of the children had an annual family income of US $5,000.00 or less, 93.7% had city water, and 79.5% had sewage. In 90.2% of the families, the number of persons per room was > 1. Of the 241 children evaluated for nutritional status, 129 (53.5%) were considered to be eutrophic, 62 (25.7%) presented mild malnutrition, 34 (14.1%) moderate malnutrition, and 16 (6.6%) severe malnutrition. The prevalence of H. pylori infection was 34.1% and was similar in boys (35.8%) and girls (32.2%). The prevalence of H. pylori infection increased significantly (p = 0.001) with age as follows: 1 month-2 yr, 16.4% (11/67); 3-5 yr, 36.7% (22/60); 6-8 yr, 29.5% (13/44); 9-11 yr, 48.8% (21/43); 12-14 yr, 42.8% (9/21); and 15-18 yr, 64.3% (9/14). There was no significant difference in H. pylori infection with regard to nutritional status or the presence of sewage. CONCLUSION: The results of present study demonstrate that in Belo Horizonte, Brazil, as also reported in other developing countries, H. pylori infection occurs early and increases with age.

Adolescent↗
PubMed1993

Prevalence of Helicobacter pylori in Brazilian patients with gastric carcinoma.

Investigators have speculated on the role of Helicobacter pylori in gastric carcinogenesis. The current study was performed to evaluate prospectively the prevalence of H. pylori infection in the stomachs of Brazilian patients with gastric carcinoma. Forty patients receiving gastrectomy for gastric carcinoma were studied. H. pylori was examined in four areas without atrophy or with minor atrophic changes. Mucosal fragments were obtained for microbiologic studies in 19 cases. H. pylori was detected in 82.5% of the cases. Of the cases evaluated by histologic and microbiologic methods, 94% had positive results by at least one method. In most cases there were small numbers of microorganisms. There was no correlation between the site and histologic type of neoplasia and the presence of H. pylori. The use of more than one diagnostic method improves H. pylori detection in gastric carcinoma. The small number of microorganisms observed in gastric carcinoma cases may lead to an underestimate of H. pylori in histologic sections. This might explain the variation in H. pylori infection rates reported for patients with gastric carcinoma.

Adult↗
PubMed1993

Serodiagnosis of Helicobacter pylori infection in children by an indirect immunofluorescence test.

The objective of this study was to evaluate the accuracy of an indirect immunofluorescence (IIF) test for serodiagnosis of Helicobacter pylori infection in children and to determine how the test is affected by the presence of antibodies against Campylobacter jejuni. We studied 65 consecutive children (two with endoscopically confirmed duodenal ulcer) and a series of 18 children with duodenal ulcer. Thirty children were H. pylori negative, as determined by culture, by the preformed urease test, and by carbolfuchsin-stained smears. The microorganism was identified by microbiological methods in 35 of the 65 (53.85%) consecutive patients studied and in all children with duodenal ulcer. The titer of the IIF test was > or = 1:20 in the sera of all children with duodenal ulcer and in the sera of 30 of 33 H. pylori-positive children without duodenal ulcer. No H. pylori-negative children had titers > 1:10. A serum dilution of 1:20 discriminated between H. pylori-infected and noninfected children. Absorption with C. jejuni did not change the levels of IgG against H. pylori. When five patients who had been successfully treated with metronidazole, amoxycillin, and furazolidone for 7 days were retested, a slight decrease in anti-H. pylori IgG levels was noted from the third month on. The decrease was more significant 9 months after the eradication of the microorganism.

Adolescent↗
PubMed1993

The inflammatory response of the gastric mucosa of mice experimentally infected with "Gastrospirillum suis".

To establish an experimental model to study gastric spiral non-cultivable bacteria, 30 4-week-old female CFW (LOB) mice were inoculated with porcine gastric mucus containing "Gastrospirillum suis" and 25 mice were inoculated with mucus without "G. suis". Mice were examined 3, 7, 14, 21, 28 and 60 days after inoculation. Fragments from the membranous, oxyntic and antral gastric mucosa and from the duodenal mucosa were obtained for histological and microbiological analysis. Tightly spiralled bacteria were seen in smears and in histological sections of the antral and oxyntic mucosa from all G. suis-infected mice. The pre-formed urease test also gave positive results in both tissues. In control mice, no tightly spiralled bacteria were seen. By 7 days after inoculation, the test animals had developed an inflammatory infiltrate of mononuclear cells, some neutrophils and a few eosinophils, mainly in the lower third of the antral and oxyntic mucosa, which persisted for the remainder of the observation period. This model can assist in the understanding of several clinical, pathological and immunological aspects of infection with spiral gastric bacteria, particularly those associated with non-cultivable spiral bacteria.

Animals↗
PubMed1993

Effect of Helicobacter pylori eradication on antral gastrin- and somatostatin-immunoreactive cell density and gastrin and somatostatin concentrations.

The density of antral gastrin (G)- and somatostatin (D)-immunoreactive cells and the contents of antral gastrin and somatostatin were investigated in endoscopic antral biopsy specimens from patients with duodenal ulcer before and after eradication of Helicobacter pylori. After H. pylori eradication both antral somatostatin concentration (p = 0.0002) and antral D-cell density (p = 0.01) increased significantly. Conversely, although the number of G-cells was unchanged, antral (p = 0.0002) and serum (p = 0.001) gastrin contents decreased significantly. The number of oxyntic D-cells did not change significantly. These results strongly suggest that the hypergastrinaemia observed in H. pylori-positive patients may be due to a deficiency in antral somatostatin, which normally inhibits the synthesis and release of gastrin.

Adult↗
PubMed1993

Histology of the mucosa of gastric antrum and body before and after eradication of Helicobacter pylori.

1. Helicobacter pylori status and the histology of the antral and oxyntic mucosa were evaluated in 25 patients with duodenal ulcer treated with a triple schedule of furazolidone, metronidazole and amoxicillin, and in 16 patients treated only with cimetidine. 2. Before treatment, H. pylori was detected in all patients. One month after treatment with the antimicrobial agents, H. pylori was not found in 18 (72.0%) of 25 patients treated with the triple schedule. In the patients treated with cimetidine (N = 16) the H. pylori tests continued to be positive after treatment. 3. Inflammatory activity and intensity of gastritis were significantly reduced in patients treated with the antimicrobial agents but not in cimetidine-treated patients. Three patients who had negative cultures and improvement of gastritis 1 month after treatment became H. pylori positive again within 2 months, with concomitant reappearance of gastritis. 4. This study provides additional evidence that histological gastritis observed in H. pylori-positive patients with duodenal ulcer is due to the presence of the microorganism.

Adult↗
PubMed1993

Comparison of the urease test and of direct smear examination in the control of treatment of Helicobacter pylori-induced infection.

The sensitivity and specificity of the preformed urease test and of carbolfuchsin-stained smears for the diagnosis of the presence of Helicobacter pylori in gastric mucosa were evaluated before and after antimicrobial treatment. The results obtained by culture were used as the reference point. We studied 41 patients with endoscopically diagnosed duodenal ulcer. Twenty-five of these were treated with furazolidone (100 mg t.i.d.), amoxicillin (500 mg t.i.d.) and metronidazole (250 mg t.i.d.) for 5 days and then with only furazolidone (100 mg t.i.d.) for an additional 25 days. The 16 control patients were treated with cimetidine (800 mg, 4 times a day). The sensitivity of the urease test and of direct smear examination was 100% before treatment and 84.6% and 92.3%, respectively, after treatment. We conclude that the urease test and carbolfuchsin-stained smears, which are highly sensitive for H. pylori diagnosis, present reduced sensitivity when they are employed for the follow-up of patients treated with antimicrobials.

Adult↗
PubMed1993

Histamine content of the oxyntic mucosa from duodenal ulcer patients: effect of Helicobacter pylori eradication.

The histamine concentration of the oxyntic mucosa was determined in Helicobacter pylori-positive patients with duodenal ulcer before and after antimicrobial therapy and in H. pylori-negative subjects. Determination of serum gastrin was also performed in duodenal ulcer patients before and after H. pylori eradication. The histamine content of the oxyntic mucosa was lower in patients with duodenal ulcer than in H. pylori-negative subjects, but it increased after H. pylori eradication. Conversely, in patients in whom therapy failed to eradicate the microorganism, the histamine content remained unchanged. Serum gastrin levels fell after microorganism eradication, and the percentage of this fall was correlated with the percentage of increase in gastric histamine. In conclusion, our findings suggest that abnormalities of histamine store present in duodenal ulcer patients might be a feature of H. pylori infection.

Adult↗
PubMed1992

Spiral bacterium associated with gastric, ileal and caecal mucosa of mice.

A spiral shaped bacterium was seen in smears and histological sections (stained by carbolfuchsin) of gastric, ileal and caecal mucosa as well as in stool smears from mice. A significant correlation between the presence of the spiral bacterium and the occurrence of gastritis was observed but the ileal and caecal mucosa seemed unaffected. The bacterium was Gram negative and grew on BHM and Skirrow's medium, under microaerophilic conditions, at 37 degrees C. Its major biochemical characteristics included positive catalase and oxidase reactions and a rapidly positive urease test. There were 2 or 3 spiral turns per cell and a tuft of up to 12 sheathed flagella on each pointed end. Entwined, braided periplasmic fibrils covered the surface of the cell. This spiral bacterium seemed to be part of the normal intestinal flora but was associated with gastritis.

Animals↗
PubMed1992

Indirect immunofluorescence determination of the frequency of anti-H. pylori antibodies in Brazilian blood donors.

1. The accuracy of an indirect immunofluorescence (IIF) test for the serodiagnosis of Helicobacter pylori infection was evaluated in adult patients and compared with culture, preformed urease test and smears stained with carbolfuchsin. 2. We studied 80 consecutive patients submitted to gastroduodenoscopy (17 of whom were found to have duodenal ulcer) plus 57 patients with duodenal ulcer. 3. H. pylori was identified by microbiological methods in 65 of the 80 consecutive patients and in all 57 patients with duodenal ulcer. 4. Among the 74 patients with duodenal ulcer, 71 presented antibody titers > or = 1:20 and 46 of the 48 H. pylori-positive patients without duodenal ulcer presented antibody titers > or = 1:20. 5. Thirteen of the 15 H. pylori-negative patients presented antibody titers < or = 1:10. 6. The sensitivity, specificity and positive predictive value of the IIF test were 95.9%, 88.8% and 98.4%, respectively. 7. The seroprevalence of H. pylori in 380 asymptomatic Brazilian blood donors was also studied by the IIF test. The presence of IgG antibodies against H. pylori was observed in 62.1% of the individuals. The prevalence of H. pylori infection increased with age and no difference was observed between males (60.3%) and females (66.6%).

Adolescent↗
PubMed1991

Differences in distribution and severity of Helicobacter pylori gastritis in children and adults with duodenal ulcer disease.

The presence of Helicobacter pylori and the gastric mucosa histology were investigated in 15 children and 15 adults with duodenal ulcer. The microorganism was isolated from antral and oxyntic mucosa in 100% of patients, both adults and children. The results of Gram stain and preformed urease test were compared with those of culture and there was no difference in sensitivity among the tests. Antral chronic gastritis was observed in all patients. However, children presented oxyntic gastritis more frequently than adults. It was also observed that the endoscopic aspects were different in the two groups of patients. The results here observed strongly support the idea that, as well as in adults, H. pylori is the causative agent of the gastritis seen in children with duodenal ulceration. On the other hand, the histological findings of oxyntic mucosa of children with duodenal ulcer were different from those of adults.

Adolescent↗
PubMed1991

Histopathological study of porcine gastric mucosa with and without a spiral bacterium ("Gastrospirillum suis").

Tightly spiralled bacteria ("Gastrospirillum suis") were seen in the pyloric mucosa of the stomach of 13 (10.8%) of 120 pigs that appeared clinically healthy at slaughter and in the fundic mucosa of three (5.0%) out of 60 pigs. The spiral organism could not be cultured from any pig. Chronic gastritis was observed in the pyloric mucosa of 53 (44.2%) of 120 pigs and in the fundic mucosa of 7 (11.7%) of 60 pigs. The 13 pigs with spiral bacteria in the pyloric region comprised one animal (7.7%) with normal pyloric mucosa, two (15.4%) with "borderline gastritis", and 10 (76.9%) with chronic gastritis--in one instance accompanied by signs of activity (numerous polymorphonuclear cells). The three pigs with spiral bacteria in the fundic mucosa comprised two animals with a normal fundic region and one with "borderline gastritis". The presence of the spiral bacterium was significantly associated with pyloric gastritis (p = 0.013) and with numbers of lymphoid follicles (p = 0.014).

Animals↗
PubMed1991

Histamine concentration of gastric mucosa in Helicobacter pylori positive and negative children.

The histamine concentration was determined by enzymatic isotopic method in biopsy specimens of oxyntic mucosa from 37 children. Nineteen of the 37 had Helicobacter pylori associated gastritis (9 with duodenal ulcer). The histamine concentration in the H pylori negative group was mean (SD) 54.1 (23.1) micrograms/g fresh weight, and that in the H pylori positive group was 26.3 (14.2) micrograms/g (p less than 0.01). There was also a significant difference between H pylori positive patients with duodenal ulcer (19.8 (6.3) micrograms/g) and those without ulcer (31.4 (17.9) micrograms/g) (p less than 0.05). These results suggest that H pylori positive patients, especially those with duodenal ulcer, have reduced 'stored' histamine, perhaps because of increased histamine liberation.

Adolescent↗
PubMed1991

Helicobacter pylori and gastric histamine concentrations.

An enzyme isotopic assay was used to determine the histamine concentration in the gastric mucosa of patients positive for Helicobacter pylori with (n = 11) and without duodenal ulceration (n = 9) and in negative controls (n = 7). A significant difference was observed when the histamine content of H pylori negative subjects was compared with that of positive patients. On the other hand, there was no significant difference in histamine concentration between H pylori positive patients with duodenal ulceration and those without duodenal ulceration. H pylori positive patients with and without duodenal ulceration had significantly lower gastric histamine concentrations than H pylori negative subjects. The lower gastric histamine concentration observed in H pylori positive patients might be due to increased histamine release which could in turn induce increased gastric acid secretion.

Adult↗
PubMed1991

Diagnosis and distribution of Helicobacter pylori in the gastric mucosa of symptomatic children.

1. The demonstration of the association of H. pylori with gastritis and peptic ulcer has been of increasing interest to gastroenterologists, microbiologists, and histopathologists. 2. In this study, the presence of H. pylori in the gastric mucosa of children was investigated by culture, preformed urease test, and carbolfuchsin staining of biopsy smears. 3. The organism was detected in 44.9% of the children studied, and found to be distributed equally on the antral and fundic mucosa. 4. Compared to culture, the urease test and carbolfuchsin staining proved to be of higher sensitivity and specificity in detecting H. pylori.

Adolescent↗