Biomedical subjects

U Fagundes-Neto

Publications and source records attributed to U Fagundes-Neto.

60 records · Page 4Linked to original sources

PubMedDate not supplied

Morphometric study of the small bowel mucosa in infants with diarrhea due to enteropathogenic Escherichia coli strains.

BACKGROUND/AIMS: Enteropathogenic Escherichia coli (EPEC) strains are the most important cause of gastroenteritis in infants under 1 year of age and may induce several patterns of villous atrophy in the intestinal mucosa. However, the interpretation of these abnormalities has usually been based on semiquantitative criteria, giving rise to considerably subjective results. We utilized the linear morphometry to analyze the morphological lesions of the small bowel mucosa induced by EPEC strains in infants with persistent diarrhea in comparison with those seen in infants with asymptomatic environmental enteropathy (AEE) and controls. METHODOLOGY: Fifty nine specimens of small bowel mucosa were comparatively studied and divided in the following groups: 1. Group I: Thirty infants with persistent diarrhea due to EPEC strains, mean age 6.4 months; 2. Group II: Sixteen infants with AEE, mean age 6.5 months with no enteropathogenic bacteria in stools; 3. Group III: Thirteen children with short stature and no gastrointestinal complaints, mean age 15 months. Morphometric analysis of the small bowel mucosa was performed by using a x10 objective to a Zeiss light microscope, to which a measuring Zeiss ocular, t8x was adapted. The following measurements were carried out: Total mucosal thickness (TMT); Villous height (VH); Crypt length (CL); Intraepithelial lymphocyte (IEL) count. RESULTS: Except for the IEL, there was a significant difference in all the parameters analyzed among the evaluated groups. Group I revealed the lowest values for total mucosal thickness, villous height, and the ratio villous height/crypt length in comparison with the two other groups. On the other hand, the crypt length measurements for Group II were larger than those for Groups I and III. The measurements of villous height and the ratio villous height/crypt length for Group III turned out to be greater than those for Group II. CONCLUSIONS: The utilization of an accurate technique in the morphological study of the small bowel mucosa allowed us to detect severe abnormalities not only in infants with EPEC infection, but also in those counterparts who live in contaminated environments, and can therefore potentially acquire this type of intestinal infection.

Bacterial Adhesion↗

PubMedDate not supplied

[Classic enteropathogenic Escherichia coli].

Enteropathogenic Escherichia coli. (EPEC) are gram negative bacteria of great importance in the etiology of diarrhea in children under two years of age living in developing countries. It was first reported in 1946. Its pathogenic mechanism was unknown until 1970 when several papers were published in the attempt to find out their physiophatologic mechanism. These bacteria interfere on the small bowel resulting in parcial or sub total villous atrophy. This injury will revert when the infection subsides.

Diarrhea, Infantile↗

PubMedDate not supplied

[Scanning electronic microscopy of the small intestine in persistent diarrhea].

Persistent diarrhea very often leads children to malnutrition. It has become the major cause of death resulting from acute diarrhea episodes in developing countries. In order to determine the ultrastructural alterations of the small bowel that occur in the syndrome, 16 infants with severe persistent diarrhea were studied, utilizing light microscopy and the scanning electron microscope. Stool and jejunal fluid samples were collected for culture, rotavirus, ova and parasite search. Enteropathogenic agents were isolated in stools from 11 (68.7%) patients and bacterial proliferation in the small bowel was detected in 11 (68.7%) patients. EPEC strains were the most frequent enteropathogenic agent isolated both from stool and jejunal fluid cultures. The stool cultures revealed the presence of the following enteropathogenic microorganisms: EPEC 0111 in four, EPEC 0119 in one, EAggEC in five, Shigella flexneri in two, and Shigella sonnei in one; mixed infections due to EAggEC associated with EPEC 0111 were seen in two patients. The light microscopic analysis revealed that 56.2% of the patients suffered moderate villous atrophy most frequently associated with effacement of the microvilli, intracytoplasmatic vacuolization, increased number of multivesicular bodied and increased lymphocytic and eosinophylic infiltration in the lamina propria. The scanning electron microscopic analysis revealed in all cases shortening of the villi and enterocyte derangements; very often there was a total lack and/or effacement of the microvilli; in half of the patients there was a mucoid material covering the enterocytes tightly adhered to the apical epithelium surface. The scanning ultrastructural alterations observed in these patients are probably due to an association of factors brought about by the presence of enteropathogenic microorganisms and the resulting food intolerance that is responsible for perpetuation of diarrhea.

Diarrhea, Infantile↗

PubMedDate not supplied

[Acute diarrhea: stool water loss in hospitalized infants and its correlation with etiologic agents and lactose content in the diet].

Forty weaned male infants were studied during their first year of life, all hospitalized with acute diarrhea in the Gastroenterology and Metabolism Unit of the Hospital "Umberto I", São Paulo, SP, Brazil. We evaluated and quantified water fecal losses, employing the metabolic bed technique, relating the feeding formula employed with the different causal enteropathogenic agents. 67.5% of the studied infants were under six months and 40% under three months of age. Two groups were randomly assembled to receive, lactose or lactose free feeding formulae. Twenty one patients received a lactose-containing formula (Ninho 10%) and the other 19 children were fed caseine (Portagen) formulae. According to coproculture results and identification of enteropathogenic agents, we divided the studied infants relating feeding formula with the presence or absence of the enteropathogenic Escherichia coli (EPEC): I-13 with positive coproculture for EPEC and diets which included lactose--(L/EPEC+); II--eight with negative coproculture for EPEC and diets which included lactose--(L/EPEC-); III--seven with positive coproculture for EPEC and lactose free diets--(G/EPEC+); IV--12 with negative coproculture for EPEC and lactose free diets. (G/EPEC-). The most frequently isolated agent at coproculture was EPEC, in 20 of the cases (50%), followed by Campylobacter (7.5%). It was also possible to observe that the frequencies of EIEC, Salmonella and Rotavirus were all equal (2.5%). Mixed infections occurred only between EPEC and EIEC, registering a frequency of 5%. The EIEC samples, associated to EPEC 0111 were serotyped as 0 28 ac: H- and 0 152:H-. The use of metabolic bed made the evaluation of fecal volumes possible by a simple and quick technique, thus allowing a closer clinical monitoring, as well as a more reliable evaluation of the patients hospitalized with acute diarrhea. Average acceptance volumes of the formulae--either with or without lactose--were always below the amount recommended by FAO/WHO (100 kcal/day) which shows the impact of acute diarrhea on the decrease of food intake. The average volumes of watery fecal losses found among any of the studied subgroups may be considered quite relevant when compared to standard values. Especially within the L/EPEC+ group fecal losses, both on the first day (83.56 ml/kg/day) and, mainly, on the second (119.44 ml/kg/day) reached exceedingly high levels indicating a disastrous association between the presence of EPEC in the small intestine and lactose offer in the diet. Thus, the results show that there exists a positive and significant association between poor lactose absorption and the presence of EPEC in the feces. WHO's recommendation proposing the use of diluted cow milk, in universal and indiscriminate administration, in the two first days of the disease, may represent a risk factor, not only for malnutrition, but also for the survival rates of children with severe diarrhea, especially those under six months of age and hospitalized with EPEC enteroinfection.

Acute Disease↗

PubMedDate not supplied

[Lactose intolerance in hospitalized infants with acute diarrhea due to classic enteropathogenic Escherichia coil (EPEC)].

Three hundred and eleven hospitalized weaned infants with acute diarrhea, all under 12 months of age, were studied in order to evaluate the development of lactose intolerance and its association with age, nutritional status, birth weight, dehydration and enteropathogenic agents identified in fecal samples. After been rehydrated the infants received whole cow' milk assuring the intake of 100 kcal/kg per day. Lactose intolerance was defined according t the following criteria: 1) persistence of diarrhea associated with weight loss during 48 hours, 2) development of vomiting and/or abdominal distention associated with excretion of carbohydrate in feces and/or acids tools, 3) metabolic acidosis associated with abdominal distention at anytime of refeeding period. Lactose intolerance was detected in 52.1% (162/311) of the patients and it was significantly associated with age under 6 months (P < 0.01), birth weight under 3000 grams (P < 0.01), development of dehydration (P < 0.01) and with enteropathogenic Escherichia coli (EPEC) serotypes infection (P < 0.01).

Acute Disease↗

PubMedDate not supplied

[Mortality in breast-fed infants with persistent diarrhea: risk factors associated with death].

OBJECTS: Persistent diarrhea is a frequent disease in developing countries. In this research, we studied 21 patients that passed away among 189 that were hospitalized with persistent diarrhea at the "Hospital Italo Brasileiro Umberto I Foundation", from January of 1985 until December of 1992. PATIENTS AND METHODS: The patients were distributed into two groups: survival and dead, in accord of the clinical evolution at the end of the internment. The analyzed parameters were: birth weight, sex, age, provenance, diarrhea period before the admission, nutritional status, hydration status, coprologic results, occurrence of food intolerance, internment period and the age of ending breast-feeding. RESULTS: The parameters that showed significantly association with the death were: age, with relative risk = 3 for children with age below 6 months old; provenance, with relative risk = 3.4 for patients who were arrived from other hospitals; third grade dehydration at the admission (relative risk = 2.9); enteropathogenic Escherichia coli (EPEC) isolated in feces (relative risk = 3.3), and use of total parenteral nutrition. The etiologic research was positive in 57.1% of the cases. The enteropathogen more frequently isolated in dead group, was EPEC (42.9%), followed by Shigella (9.5%) and Salmonella (5.9%). From the isolated EPEC (35/189), 26 (74.3%) were belonged to the OIII sorogroup (6/26). From these children, 23.1% died. From the 35 patients with EPEC isolated in feces, 25 were below 6 months old, and from these one, eight died. The relative risk to die for lactents with less than 6 months old and EPEC in feces was equal 3.2. Sepsis was considered the most important cause of death for hospitalized lactents with persistent diarrhea.

Age Factors↗