Bleaching Gels Used After 1 Week of Mixing: Efficacy, Hydrogen Peroxide Penetration, and Physical-chemical Properties.

OBJECTIVES: This in vitro study aimed to evaluate the bleaching efficacy (BE), hydrogen peroxide penetration into the pulp chamber (HPP), and physical-chemical properties (concentration, pH, and viscosity) of in-office bleaching gels immediately and after 1 week of mixing. METHODS AND MATERIALS: We randomly divided 49 premolars into seven groups: control (no bleaching) and the following in-office bleaching (Opalescence Boost 40%, Total Blanc One Step 35%, and Whiteness HP Blue 35%) applied at two storage times: immediately and after 1 week. We evaluated the BE using a digital spectrophotometer and the HPP through UV-Vis spectroscopy. We measured the initial concentration, pH, and viscosity using titration, a Digital pH meter and Rheometer, respectively. For statistical analysis, we used a twoway analysis of variance and Tukey and Dunnet tests (α=0.05). RESULTS: We observed higher BE and HPP for Opalescence Boost and Total Blanc One Step after 1 week of mixing than for Whiteness HP Blue (p<0.001). We observed a significantly lower initial concentration for Whiteness HP Blue 1 week after mixing compared to immediately (p=0.00001). All bleaching gels showed a decrease in pH after 1 week of mixing (p=0.00003). However, Total Blanc One Step had a lower pH at both evaluation times (p<0.001). Only Opalescence Boost maintained viscosity 1 week after mixing. CONCLUSIONS: Opalescence Boost was the only bleaching gel able to keep bleaching efficacy, with the same characteristics of permeability and physical- chemical properties after 1 week of mixing.

Rendimento industrial de filetagem da tilápia tailandesa (Oreochromis spp) / Industrial filefish processing yield of Thailand tilapia (Oreochromis spp)

Avaliaram-se o rendimento de filetagem e os valores percentuais das partes de tilápia tailandesa (Oreochromis spp.), no âmbito de uma empresa em Minas Gerais, durante o período de janeiro a novembro de 2004. Foram processadas 4260 tilápias (2560 quilos), registrando-se os pesos totais dos peixes e de suas partes principais, o desempenho da mão-de-obra e o tempo gasto no processo. Os peixes foram distribuidos em três classes de peso (300 a 600g; 601 a 800g e 801 a 1000g) O rendimento médio de filetagem foi de 31,0 por cento, variando de 28,9 por cento a 33,6 por cento, complementado por 36,0 por cento de cabeça e vísceras, 8,0 por cento de pele, 22,0 por cento de resíduo ósseo e 3,0 por cento de restos de toilet. Não houve diferença no rendimento de filetagem (P>0,05), entre as três classes de pesos. Verificaram-se que as variações dos percentuais e o desempenho dos operários têm impacto na competitividade da empresa.

Echocardiographic assessment of the different left ventricular geometric patterns in hypertensive patients.

OBJECTIVE: To identify left ventricular geometric patterns in hypertensive patients on echocardiography, and to correlate those patterns with casual blood pressure measurements and with the parameters obtained on a 24-hour ambulatory blood pressure monitoring. METHODS: We studied sixty hypertensive patients, grouped according to the Joint National Committee stages of hypertension. Using the single- and two-dimensional Doppler Echocardiography, we analyzed the left ventricular mass and the geometric patterns through the correlation of left ventricular mass index and relative wall thickness. On ambulatory blood pressure monitoring we assessed the means and pressure loads in the different geometric patterns detected on echocardiography RESULTS: We identified three left ventricular geometric patterns: 1) concentric hypertrophy, in 25% of the patients; 2) concentric remodeling, in 25%; and 3) normal geometry, in 50%. Casual systolic blood pressure was higher in the group with concentric hypertrophy than in the other groups (p=0.001). Mean systolic pressure in the 24h, daytime and nighttime periods was also higher in patients with concentric hypertrophy, as compared to the other groups (p=0.003, p=0.004 and p=0.007). Daytime systolic load and nighttime diastolic load were higher in patients with concentric hypertrophy ( p=0.004 and p=0.01, respectively). CONCLUSIONS: Left ventricular geometric patterns show significant correlation with casual systolic blood pressure, and with means and pressure loads on ambulatory blood pressure monitoring.

Experimental Salmonella enterica serovar Pullorum infection in two commercial varieties of laying hens.

An experiment was carried out to investigate the biology of Salmonella Pullorum in two varieties of laying hens, from 5 days of age up to 9 months. One variety was resistant to systemic salmonellosis (light layers producing white eggs) and the other was considered susceptible (brown layers producing brown eggs). The brown birds were more affected by the infection, showing signs of clinical disease in the first month of life. Later, these signs disappeared, but postmortem examination revealed persistent gross pathological changes in the liver, spleen, heart and ovary. The rapid agglutination test detected reactors throughout the experiment, with the strongest agglutination from 1 to 7 months post-infection. S . Pullorum was isolated from some of the organs and the eggs laid throughout the experiment. The relationship between white birds and S . Pullorum was less intense, and there were no noticeable signs of disease. There were few gross pathological changes, and the bacteria were isolated infrequently and only for a brief period after infection, although contaminated eggs were laid by these birds. The strongest serological response in the white chickens occurred between the second and the fifth month post-infection.

Doppler echocardiographic study in adolescents and young adults with sickle cell anemia.

OBJECTIVE: Anatomical and functional assessment of the heart through Doppler and echocardiography in patients with cell anemia (SCA). METHODS: Twenty-five patients with SCA and ages ranging from 14 to 45 years were prospectively studied in a comparison with 25 healthy volunteers. All of them underwent clinical and laboratory evaluation and Doppler echocardiography as well. The measurements were converted into body surface indices. RESULTS: There were increases in all chamber diameters and left ventricle (LV) mass of the SCA patients. It was characterised an eccentric hypertrophy of the left ventricle. The preload was increased (left ventricle end-diastolic volume) and the afterload was decreased (diastolic blood pressure, peripheral vascular resistance and end-systolic parietal stress ESPS). The cardiac index was increased due to the stroke volume. The ejection fraction and the percentage of the systolic shortening, as well as the systolic time intervals of the LV were equivalent. The isovolumetric contraction period of the LV was increased. The mitral E-septum distance and the end-systolic volume index (ESVi) were increased. The ESPS/ESVi ratio,a loading independent parameter, was decreased in SCA, suggesting systolic dysfunction. No significant differences in the diastolic function or in the pulmonary pressure occurred. CONCLUSION: Chamber dilations, eccentric hypertrophy and systolic dysfunction confirm the evidence of the literature in characterizing a sickle cell anemia cardiomyopathy.

Metilprednisolona intravenosa em altas doses (pulsoterapia): possível solução terapêutica para a febre reumática ativa com cardite grave / High-dose intravenous methylprednisolone (pulsetherapy): possible therapeutic solution for active rheumatic fever with severe carditis

Oito pacientes com cardite reumatica ativa a maioria em franca insuficiencia cardiaca foram tratados com esquema de pulsoterapia (lg de metilprednisolona intravenosa). Foram acompanhados por exame clinico,eletrocardiograma, radiografia de torax, provas de atividade reumatica e ecocardiograma. A melhora da insuficiencia cardiaca ocorreu em dias. Esta forma de terapeutica tornou possivel o controle da insuficiencia cardiaca, certamente imunologica em curto periodo de tempo e sem efeitos adversos. Ela permitira, tambem, maior abrangencia em situacoes especiais de insuficiencia cardiaca auto-imune