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Biomedical subjects

M A Araujo

Publications and source records attributed to M A Araujo.

6 recordsLinked to original sources

Microleakage and nanoleakage: influence of laser in cavity preparation and dentin pretreatment.

OBJECTIVE: The purpose of this study was to verify if the application of the Nd:YAG laser following pretreatment of dentin with adhesive systems that were not light cured in class V cavities and were prepared with Er:YAG laser would promote better sealing of the gingival margins when compared to cavities prepared the conventional way. BACKGROUND DATA: Previous studies had shown that the pretreatment of dentin with laser irradiation after the application of an adhesive system is efficient in achieving higher shear bond and tensile bond strength. MATERIALS AND METHODS: Er:YAG laser (Kavo-Key, Germany) with 350 mJ, 4 Hz, and 116.7 J/cm2 was used for cavity preparation. The conventional preparation was made with diamond bur mounted in high-speed turbine. Dentin treatment was accomplished using an Nd:YAG laser (Pulse Master 1000, ADT. USA) at 60 mJ, 10 Hz, and 74.65/cm2 following application of the adhesive system. The cavities were stored with Single Bond/Z100 and Prime & Bond NT/TPH. Eighty bovine incisors were used, and class V preparations were done at buccal and lingual surfaces divided into eight groups: (1) Er:YAG preparation + Prime & Bond NT + TPH; (2) Er:YAG preparation + Single Bond + Z100; (3) Er:YAG preparation + Single Bond + Nd:YAG + Z100; (4) Er:YAG preparation + Prime & Bond NT + Nd:YAG + TPH; (5) conventional preparation + Prime & Bond NT + TPH; (6) conventional preparation + Single Bond + Z100; (7) conventional preparation + Single Bond + Nd:YAG + Z100; (8) conventional preparation + Prime & Bond NT + Nd:YAG + TPH. All specimens were thermocycled for 300 full cycles between 5 degrees C+/-2 degrees C and 55 degrees C+/-2 degrees C (dwell time of 30 sec), and stored in 50% silver nitrate solution for 24 h soaked in photodeveloping solution and exposed to fluorescent light for 6 h. After this procedure, the specimens were sectioned longitudinally in 3 portions and the extension of microleakage at the gingival wall was determined following a criteria ranging from 0 to 4 using scanning electron microscopy (SEM). The medium portion sectioned of each specimen was polished and prepared for nanoleakage avaliation by SEM. RESULTS: Kruskall-Wallis and Miller statistical tests determined that group 3 presented less microleakage and nanoleakage. CONCLUSION: Application of the Nd:YAG laser following pretreatment of dentin with adhesive Single Bond non-photocured Single Bond adhesive in cavities prepared with Er:YAG promote better sealing of the gingival margins.

Animals↗

Clinics in diagnostic imaging (52). Spinal cord schistosomiasis.

A 2-year-old Brazilian boy presented with bilateral leg weakness and constipation, followed by development of progressive paraparesis and bladder dysfunction. Neurological examination revealed flaccid paraparesis. Blood tests and CSF analysis showed eosinophilia. The MR examination revealed a spinal cord mass extending from T9 to L1 levels, with a heterogeneously-enhancing solid component and a cystic component. Stool tests for Schistosoma mansoni eggs were positive. The patient underwent surgery, the intramedullary mass was partially resected, and the diagnosis of spinal cord infection by Schistosoma mansoni was confirmed. After surgery, the patient was treated with praziquantel and oxamniquine. He was discharged with partial improvement of the lower extremity weakness and bowel/bladder function. The clinical and imaging features of spinal cord schistosomiasis are reviewed.

Child, Preschool↗

Ultrasound findings in children with toxocariasis: report on 18 cases.

PURPOSE: To evaluate abdominal ultrasound (US) findings in children infected with Toxocara canis. MATERIALS AND METHODS: Eighteen children, 18 months to 7 years of age, with serological diagnosis of T.canis infection underwent abdominal US. Eosinophil counts, hemoglobin levels and immunoglobulin E titers were measured for all patients. RESULTS: Abdominal ultrasound revealed multiple hypoechoic areas in the livers of 15 patients (83.3%). Hepatohilar lymph-node enlargement was present in 14 patients (77.7%), 2 of whom also showed peripancreatic lymph-node enlargement. Hepatomegaly was present in 13 patients (72.7%) and splenomegaly in 9 (50%). CONCLUSION: The most prevalent findings of abdominal ultrasound examination of children with T.canis infection are hepatic granulomas and abdominal lymph-node enlargement. This infection should be considered in the differential diagnosis of any children who exhibit these findings on abdominal US examination, especially for those with eosinophilia.

Animals↗

Prevalence of anti-Leishmania donovani antibody among Brazilian blood donors and multiply transfused hemodialysis patients.

The prevalence of anti-Leishmania donovani antibodies was investigated in 1,500 Brazilian blood donors and multiply transfused hemodialysis patients. Sera were tested using the fucose-mannose ligand (FML) ELISA, which was shown to have 100% sensitivity and 96% specificity for kala-azar. Among 1,194 volunteer blood donors, seroreactivity was 9%, increasing to 25% in a periurban kala-azar focus. However, higher positivity (37%) was found in multiply transfused hemodialysis patients from Natal, where kala-azar is constantly present in low numbers (endemic), with sporadic outbreaks in localized regions (endemic and epidemic). Risk factors included blood transfusion, which was significantly associated with the presence of anti-Leishmania antibodies (chi2 = 8.567, P < 0.005), but did not include potential exposure to sandfly bites (chi2 = 0.033, P > 0.1). The prevalence significantly decreased to 7% in hemodialysis patients from Rio de Janeiro, where kala-azar is only occasionally seen, and was 0% in patients undergoing continuous ambulatorial peritoneal dialysis. The prospective analysis of 27 FML-seroreactive donors from Natal revealed amastigotes of Leishmania in the bone marrow of one subject while four had clinical complaints, including splenomegaly and hepatosplenomegaly. Our results point to the need for control of blood transfusion as a possible route for transmission of kala-azar in endemic areas.

Animals↗