ABSTRACT Purpose To evaluate the effect of fractional carbon dioxide (CO2) laser treatment using lower power associated with pulse stacking within collagen fibers, using second harmonic generation microscopy and computerized image analysis. Methods Twenty male Wistar rats aging eight weeks were used. Each treatment area received a single-pass CO2 fractional laser with different parameters. The 20 animals were divided into two groups and euthanized after 30 and 60 days. Second harmonic generation images were obtained and program ImageJ was utilized to evaluate the collagen organization within all areas. Collagen anisotropy, entropy and optical density were quantified. Results Increased anisotropy over time was observed in all four areas, but only reached statistical significance (p = 0.0305) when the mildest parameters were used (area four). Entropy decreased over time in all areas, but without significance(p = 0.1779) in area four. Density showed an overtime increase only in area four, but no statistical significance was reached (p = 0.6534). Conclusions When combined, the results obtained in this study regarding anisotropy, entropy and density tend to demonstrate that it is possible to achieve collagen remodeling with the use of lower power levels associated with stacked pulses.

ABSTRACT A cytotoxicity study is performed on a poly(methyl methacrylate) polymer (PMMA) to be used for the fabrication of bone tissue by Rapid Prototyping (RP). The solution polymerization is conducted in a pilot plant reactor using more appropriated reagents in consideration of the medical application. Moreover, the polymer is efficiently handled to avoid the side effect of the monomer, reducing the concentration of this specie to 287,731 µg MMA/kg PMMA. The cytotoxicity of the polymer is determined through growth monitoring, adherence and morphology of L-929 cells. Additionally, MTT and LIVE/DEAD tests are performed. The results showed continuous and progressive growth of the cells on the surface of the specimens. Moreover, the material did not influence on the viability of mesenchymal cells and inverted fluorescence microscopy images showed a polyanionic dye calcein well retained in the cells in contact with the PMMA as well as the negative control after 72 hours. Thus, the polymer was efficiently synthesized and handled for the expected demands.

PURPOSE : To evaluate the effect of different energies and stacking in skin shrinkage. METHODS : Three decreasing settings of a fractional CO2 laser were applied to the abdomen of Twenty five Wistar rats divided into three groups. Group I (n=5) was histologically evaluated for microthermal zones dimensions. Groups II and III (n=10 each) were macroscopic evaluated with freeware ImageJ for area contraction immediately and after 30 and 60 days. RESULTS : No statistical significance was found within microthermal zone histological dimensions (Group I) in all settings studied. (Ablation depth: 76.90 to 97.18µm; Coagulation depth: 186.01 to 219.84 µm). In Group II, macroscopic evaluation showed that all settings cause significant immediate skin contraction. The highest setting cause significant more intense tightening effect initially, contracting skin area from 258.65 to 179.09 mm2. The same pattern was observed in Group III. At 30 and 60 days, the lowest setting significantly sustained contraction. CONCLUSION : Lower fractional CO2 laser energies associated to pulse stacking could cause consistent and long lasting tissue contraction in rats.

PURPOSE:To investigate the osseointegration properties of prototyped implants with tridimensionally interconnected pores made of the Ti6Al4V alloy and the influence of a thin calcium phosphate coating.METHODS: Bilateral critical size calvarial defects were created in thirty Wistar rats and filled with coated and uncoated implants in a randomized fashion. The animals were kept for 15, 45 and 90 days. Implant mechanical integration was evaluated with a push-out test. Bone-implant interface was analyzed using scanning electron microscopy.RESULTS: The maximum force to produce initial displacement of the implants increased during the study period, reaching values around 100N for both types of implants. Intimate contact between bone and implant was present, with progressive bone growth into the pores. No significant differences were seen between coated and uncoated implants.CONCLUSION:Adequate osseointegration can be achieved in calvarial reconstructions using prototyped Ti6Al4V Implants with the described characteristics of surface and porosity.

Bartonella henselae was detected in defibrinated sheep blood employed in supplementing a selective bacteria culture medium by nested PCR. We recommended that highly sensitive technical tests be run to ensure a sterile culture medium for Bartonella spp. isolation, since infected blood samples used in preparation could lead to false-positive results.

A possibilidade de que alguma contaminação por virus poderia estar alterando a resposta do hospedeiro à infecção experimental por Trypanosoma cruzi foi investigada. Os dados obtidos mostraram que camundongos CBA/J infectados com estoques de parasitos mantidos em camundongos (Y1UEC) apresentavam maior parasitemia e menor período de sobrevivência do que os infectados com um estoque (Y1TC) que também foi mantido em animal mas tinha sido previamente passado em cultura de células. Testes de produção de anticorpos em camundongos (Map tests) realizados com o plasma fliltrado de camundongos infectados com Y1UEC indicaram a presença do virus da hepatite do camundongo (MHV) enquanto nenhum virus foi detectado no plasma de animais infectados com Y1TC. O plasma filtrado obtido de camundongos infectados com Y1UEC continha um fator capaz de aumentar o nível de parasitemia e reduzir o tempo médio de sobrevivencia dos camundongos desafiados com 10(5) Y1TC. Testes de neutralização mostraram que este fator que podia ser passado seriadamente para camundongos era um coronavirus.

The possibility that some virus contaminants could be altering host response to Trypanosoma cruzi experimental infection was investigated. Data obtained showed that CBA/J mice infected with stocks of parasite maintained in mice (Y1UEC) presented higher level of parasitemia and shorter survival times than those infected with a stock (Y1TC) which was also maintained in mice but had been previously passaged in cell culture. Mouse antibody production tests, performed with the filtered plasma of mice infected with Y1UEC, indicated the presence of mouse hepatitis virus (MHV) while no virus was detected when testing the plasma of Y1TC infected mice. Filtered plasma of Y1EUC infected mice was shown to contain a factor able to enhance the level of parasitemia and to reduce the mean survival time of mice challenged with 10(5) Y1TC. This factor, that could be serially passaged to naïve mice was shown to be a coronavirus by neutralization tests.

Casais de camundongos isogênicos das raças CBA, BALB/c e machos e fêmeas de Swiss heterogenéticos criados no sistema convencional, que se encontravam infectados em diferentes graus por Myobia musculi e Myocoptes musculinus, foram submetidos a quatro esquemas de tratamento com Tetmosol. A incidência de ectoparasitas na raça C57BL/10 foi apenas 1,2%. Todos os animais da raça CBA e Swiss encontravam-se parasitados, enquanto que a infestação do BALB/c foi de 50 a 90%. Os melhores resultados dos 4 esquemas de tratamento testados foram observados utilizando-se Tetmosol na concentração 2,5% em banhos seriados com intervalos alternados de 3 e 4 dias, num período de 21 dias. A incidência de ectoparasitas adultos em CBA, BALB/c e Swiss após o tratamento foi de respectivamente 0%, 40% e 0%, enquanto que para ovos viáveis os respectivos resultados foram de 20%, 50% e 0%. Após a introdução de matrizes tratadas num sistema de criação sob barreiras, a colônia tem sido examinada sistematicamente há 24 meses e encontra-se isenta de ectoparasitas.

Colonies of CBA, C57BL/10, BALB/c and Swiss mice housed in conventional systems were found to be infected to different degrees with both Myobia musculi and Myocoptes musculinus. Groups of ten different sister-brother pairs of the isogenic mice and groups of 25 mice separated according to were infected by the parasite and then submitted to 4 different schemes of treatment with Tetmosol. C57BL/10 presented a very low incidence of parasites (1.2%). Every pair of CBA, and every Swiss mice examined, were found to be infected while only 50-90% of the pairs of BALB/c mice were infected. The best results of four different schemes were obtained by dipping the animals in 2.5% Tetmosol, at 3-4 days intervals for 21 days. The incidence of adult parasite forms in CBA, BALB/c and Swiss mice were found to be 0%, 40% and 0%, respectively, while in viable eggs it was found to be 20%, 50% and 0%, respectively.

Casais de camundongos isogênicos das raças CBA, BALB/c e machos e fêmeas de Swiss heterogenéticos criados no sistema convencional, que se encontravam infectados em diferentes graus por Myobia musculi e Myocoptes musculinus, foram submetidos a quatro esquemas de tratamento com Tetmosol. A incidência de ectoparasitas na raça C57BL/10 foi apenas 1,2%. Todos os animais da raça CBA e Swiss encontravam-se parasitados, enquanto que a infestação do BALB/c foi de 50 a 90%. Os melhores resultados dos 4 esquemas de tratamento testados foram observados utilizando-se Tetmosol na concentração 2,5% em banhos seriados com intervalos alternados de 3 e 4 dias, num período de 21 dias. A incidência de ectoparasitas adultos em CBA, BALB/c e Swiss após o tratamento foi de respectivamente 0%, 40% e 0%, enquanto que para ovos viáveis os respectivos resultados foram de 20%, 50% e 0%. Após a introdução de matrizes tratadas num sistema de criação sob barreiras, a colônia tem sido examinada sistematicamente há 24 meses e encontra-se isenta de ectoparasitas.

Colonies of CBA, C57BL/10, BALB/c and Swiss mice housed in conventional systems were found to be infected to different degrees with both Myobia musculi and Myocoptes musculinus. Groups of ten different sister-brother pairs of the isogenic mice and groups of 25 mice separated according to were infected by the parasite and then submitted to 4 different schemes of treatment with Tetmosol. C57BL/10 presented a very low incidence of parasites (1.2%). Every pair of CBA, and every Swiss mice examined, were found to be infected while only 50-90% of the pairs of BALB/c mice were infected. The best results of four different schemes were obtained by dipping the animals in 2.5% Tetmosol, at 3-4 days intervals for 21 days. The incidence of adult parasite forms in CBA, BALB/c and Swiss mice were found to be 0%, 40% and 0%, respectively, while in viable eggs it was found to be 20%, 50% and 0%, respectively.