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Biomedical subjects

L M Paiva

Publications and source records attributed to L M Paiva.

7 recordsLinked to original sources

[Gastrointestinal bleeding]

OBJECTIVE: To present an analysis of the occurrence of gastrointestinal bleeding in children and emphasize: i) diagnostic methods; ii) the organized use of different therapeutic approaches in upper gastrointestinal bleeding; iii) the review of concepts, classifications and techniques used in endoscopy, which are important to the practice of clinical pediatrics. METHODS: Literary review of chapters selected from textbooks, pertinent articles obtained through the Medline system and active search, as well as personal archives belonging to the authors. RESULTS: The differential diagnosis of gastrointestinal bleeding in children varies according to the age. The causes of upper gastrointestinal bleeding are subdivided into variceal and nonvariceal. Nonselective beta-blockers are recommended to prevent variceal bleeding. Vasoactive drugs, such as somatostatin, octreotide, and glypressin may be used, showing good results in both variceal and nonvariceal acute bleeding. Both sclerotherapy and variceal ligation can be used in children to achieve variceal eradication. Cyanoacrylate is effective and presents the lowest complication rate related to gastric variceal bleeding. The presence of hemorrhage stigmata, such as active bleeding and visible vessel in ulcers is indicative of a higher risk for recurrent bleeding, suggesting the need for endoscopic hemostasis. Proton pump inhibitors are more efficacious than H2-receptor antagonists to promote the peptic ulcer healing. CONCLUSION: The correct etiologic diagnosis of gastrointestinal bleeding in children is fundamentally important to adopt the adequate therapeutic approach, whose main advances concern the pharmacological and the endoscopic treatment.

Journal Article↗

[Measles seroprevalence among pediatricians in a teaching hospital].

OBJECTIVE: A measles outbreak occurred in S. Paulo state, during 1996 and 1997, resulting in 20,921 cases. Forty seven percent of the cases occurred in people between 20 and 29 years of age, and one of the control strategies of the Department of Health was the vaccination of health care workers. The prevalence of antibodies against measles among the hospital pediatricians was investigated. METHODS: One hundred and fifty samples were taken from volunteer pediatricians to test for measles antibodies using ELISA. A questionnaire about their having had measles and the vaccine was filled out. RESULTS: Of the 150 doctors, 122 (81.4%) were female and 28 (18.6%) male, of between 23 and 46 years of age (mean and median 27 years). The majority (98%-147/150) had protective levels of antibodies against measles (>100 UI/ml); 118 (80.3%-118/147) without and 29 (19.7%-29/147) with a history of measles. Only 3 pediatricians (2%-3/150), had negative serology, 2 without and 1 with a history of measles. Out of the 118 without history of measles, 79 (67%-39/118) in spite of the protective level of antibodies against measles, did not know if they, had been vaccinated. Out of the 79 vaccinated pediatricians, 64 (81%-64/79), had been vaccinated 25 years before, and still maintained protective levels of antibodies. Of the 3 doctors with negative serologies only one declared that he had been vaccinated. CONCLUSIONS: Measles seroprevalence among pediatricians of this hospital is high, especially due to preceding vaccination. On the other hand, the 2% of pediatricians with negative serology, in an epidemic situation could constitute a significant population for the acquisition and dissemination of the disease.

Adult↗

Inhibition of horse liver alcohol dehydrogenase and rabbit muscle lactate dehydrogenase by phenylhydrazine.

The activity of horse liver alcohol dehydrogenase was inhibited by phenylhydrazine. Kinetic experiments showed that this compound produced linear competitive inhibition with respect to NAD+ and linear noncompetitive inhibition with respect to ethanol. These results suggested that the inhibitor competes with NAD+ for the coenzyme binding site of alcohol dehydrogenase, forming a dead-end complex with the free form of the enzyme. A Ki value of 393 +/- 51 microM was estimated for the enzyme-inhibitor complex. Further evidence for this mechanism of inhibition arose from the fact that the same kind of inhibition was found for rabbit muscle lactate dehydrogenase. The Ki value for the lactate dehydrogenase-phenylhydrazine complex was 43.41 +/- 2.10 mM. The significant difference between these Ki values is explained in terms of known differences in hydrophobicity of the nicotinamide binding region in the two enzymes.

Alcohol Dehydrogenase↗

Pathological involvement of human gastrocnemius muscle in leptospirosis (a study in 63 patients).

The authors discuss the microscopic changes in gastrocnemius muscle in Leptospirosis in 63 patients. The hyaline necrosis frequently associated to a hemorrhagic infiltrate represented the most important feature in the lesional picture of the disease. Other findings were swelling, loss of cross striations, vacuolation and regenerative changes of muscle fibres. This last one was represented by multinucleated sarcoblasts and the presence of thin and strongly basophilic new-formed fibres. Interstitial hemorrhage was frequently seen and an inflammatory afflux was only rarely observed. This histological picture was considered as characteristic and highly significant for the diagnosis of Leptospirosis.

Adolescent↗