PubMed Health⌕ Search

Biomedical subjects

L Mata

Publications and source records attributed to L Mata.

87 records · Page 5Linked to original sources
PubMedDate not supplied

Ultrastructure of the vacuolar apparatus in the renal proximal tubule microinfused in vivo with the cytological stain light green.

To obtain insight into the basic mechanisms controlling endocytosis, we tested the effects of different perfusates containing the cytological stain light green on endocytosis and ultrastructure of the vacuolar apparatus in renal proximal tubule cells. Rat proximal tubules were microinfused in vivo for 2 min in the presence or absence of light green with the following solutions: (A) perfusates containing inorganic salts and (B) perfusates with organic components or protein. In other experiments, the tubules were first microinfused for 2 min with 0.9% NaCl in the presence or absence of light green, then 15 min later further microinfused with or without light green using either group A or B solutions in order to either aggravate or reverse possible changes. All infused tubules were fixed after 5 min with 1% glutaraldehyde and examined by electron microscopy. In tubules microinfused without light green, the endocytic vacuolar apparatus in the apical cytoplasm showed a normal ultrastructure. However, microinfusion of solutions containing light green in either inorganic salts or a low concentration of protein caused significant changes in the apical endocytic apparatus. Large endocytic vacuoles were absent, and invaginations and small endocytic vacuoles were decreased in frequency. On the other hand, the amount of dense apical tubules was significantly increased, and in some cells dense apical tubules had transformed into a cisternalike network. These changes were aggravated in tubules which received a second microinfusion of NaCl and reversed in tubules that received a second infusion of protein. Furthermore, in the tubules microinfused with light green using perfusates containing organic components or protein, the apical cytoplasm of proximal tubule cells showed an essentially normal endocytic apparatus. The present study demonstrates that microinfusion of renal proximal tubules with light green disrupted normal endocytic membrane trafficking and recycling. These changes could be prevented or reversed by microinfusion of solutions containing protein or organic components.

Animals↗
PubMedDate not supplied

[Cryptosporidiosis in children from 1 to 2 years of age, with acute diarrhea in Belém, Pará, Brazil].

Two hundred and one samples obtained from 61 children were examined for Cryptosporidium infection during a period of 12 months. One hundred fifteen specimens were collected during diarrhoea episodes and the remaining 86 obtained out of diarrhoea period, as controls. All samples were examined by a modified Ziehl-Neelsen staining method. Cryptosporidium was detected in 6 (5.2%) of 115 samples from diarrhoeic children. All non-diarrhoeic control patients were negative for Cryptosporidium. The present study suggests that Cryptosporidium is an agent of self-limited diarrhoea among immunocompetent children from Belém, Pará.

Animals↗
PubMedDate not supplied

[Solitary rectal polyp and endoscopic polypectomy in a pediatric population: 3 years' experience].

During defecation, rectal polyps represent one most frequent causes of bleeding in infancy. The advent of endoscopic polypectomy has resulted very useful in their treatment. From January 1987 to March 1990, 113 children with rectal bleeding were evaluated; 22 of them had solitary rectal polyp, between 5 to 15 cm from anal margin at rectoscopy. 6 patients were excluded because they had autoamputation of the polyp, 16 patients, 9 girls and 6 boys between 2 and 11 years of age were studied with blood tests, series stools, contrast study with barium, colonoscopy with polypectomy and polyp histology investigation. 14 patients had chronic anemia, 10 had parasitic in stools. The barium enema identified rectal polyps in 14 patients (87.5%), colonoscopy and polypectomy was performed in every children. Juvenile histologic type predominated (82%). It is demonstrated that chronic anemia can follow rectal bleeding by polyps in children. Parasitic infections such as tricocephalous in conjunction with solid feces, may have a traumatic effect and produce chronic inflammation. Double contrast X-rays of the colon is useful to identify polyps. Non complications were observed during or after polypectomy. It is demonstrated that endoscopic polypectomy in children is a simple, safety and effective method.

Child↗
PubMedDate not supplied

[Rotavirus in children with severe malnutrition].

The study comprised 19 children with severe protein-calorie malnutrition admitted to Hospital Nacional de Niños. With one exception, all of the patients complained of diarrhea at the examination. Samples of stools were collected for bacteriologic, parasitologic and virologic studies. Rotavirus was shown in 4 cases and adenovirus in another 4. Enteropathogenic Escherichia coli, Shigella and Salmonella were isolated in 9 different children. It was possible to demonstrate at least one potentially pathogenic agent in 84% of the total number of cases. In malnourished infants under one year of age, the index of positiveness was 100%. It is set forth that infection is the most important factor in the etiology of diarrhea of the malnourished infant.

Child↗
PubMedDate not supplied

[Diarrhea outbreak and bacterial resistance to ampicillin in newborns].

Twenty-eight healthy neonates from the San Juan de Dios Hospital were studied to determine the pattern of antibiotic resistance of indigenous intestinal bacteria. Sixty-eight per cent of infants had enterobacteriaceae resistant to several wide-spectrum antibiotics, including ampicillin; 28 per cent of the cultures had plasmid-mediated ampicillin resistance. In the course of the study, an outbreak of 10 acute cases of diarrhea occurred, not associated to any of the commonly known agents, including the rotaviruses. Enterobacteriaceae multiple resistant were isolated from all cases; ampicillin-resistant strains were found in all; those resistances were mediated by transmissible plasmids. Several sites of the Neonatology Ward were sampled and two yielded E. coli with resistance to 8 drugs transmissible in vitro. The outbreak was controlled after strict hygienic measures were established in the ward. A following sample showed a decrease in indigenous antibiotic-resistant strains, especially E. coli; however, plasmid mediated resistant Klebsiella was still isolated several months later. The need to regulate the use of antibiotics; to educate the medical personnel and the public in general and to modify the hospital norms and regulations are discussed in the paper.

Ampicillin↗
PubMedDate not supplied

[Recovery of the acute malnourished child in Costa Rica, by using caloric hyperalimentation].

This study was conducted at the National Children's Hospital, in Costa Rica. Fifteen malnourished children (means upon admission: age 7.5 months; 55.2% weight for age; 74.3 weight for height) were treated according to a new feeding scheme in which hypercaloric formulas were given to children from the seventh day onwards. The children achieved a mean weight gain of 8.7 g/kg/day after the first week of hospitalization. A strong correlation was found between caloric intake and weight gain (r = 0.78). The equation Y = -10.36 + 0.1X indicates and additional caloric requirement of 10 Kcal/kg/day for synthesis of tissue of 1 g/kg/day. Children achieved an average of 90% weight/height four weeks after initiation of treatment, advancing from grade III to grade II (weight deficit, Gómez classification) The application of this feeding scheme will reduce hospitalization cost, the risk of cross-infections, the rate of readmissions, and will favor a better adaptation of the child to his own environment.

Body Weight↗
PubMedDate not supplied

[Rehydration by the oral route and its maintenance in patients from birth to 3 months old dehydrated due to diarrhea].

Studies of oral rehydration have been carried out in patients three months of age or older. With the exception of a previous report by us, nothing has been written before about the method of rehydration in patients of less than three month of age. During the period comprised between March 1978 and May 1979, we attended 106 patients; age ranging from seven days to three months and weighing 1,900 to 6,080 grams. The The dehydration status ranged from 2% - 4%; in all cases due to watery diarrhoea. Oral or nasogastric rehydration was accomplished in 97% of cases in an average time of seven hours. Several patients presented severe water and electrolyte unbalance, namely metabolic acidosis or hypernatremia. This returned near normality as the patients became rehydrated. We conclude that patients under 3 months of age respond as well as older ones to oral rehydration.

Administration, Oral↗
PubMedDate not supplied

[Infectious agents in diarrhea of hospitalized children in Costa Rica].

Shigella, toxigenic Escherichia coli (stable toxin) and rotaviruses were frequently found among 50 children hospitalized with diarrhea studied during one year. These agents were less common among 45 controls without diarrhea, of comparable age and from the same wards as the cases reported. There was a greater frequency of respiratory symptoms in the diarrhea associated with rotaviruses. These were characterized by frequent bowel movements and vomiting and often fever. The bacterial diarrheas showed, in general, a more severe clinical picture than the viral ones. The rotaviruses had a low endemic level during April-October, but their prevalence increased in December and January; in such months these viruses were found in more than 50 per cent of the diarrheal cases.

Acute Disease↗