Comparison of subcutaneous inflammatory response to commercial and engineered zinc hydroxyapatite implants in rabbits / Comparação da resposta inflamatória subcutânea aos implantes de hidroxiapatita comercial e modificada com zinco em coelhos

Hydroxyapatite (HA) is widely used as a biomaterial for bone repair and metallic prostheses coating. The main limitations of the current commercial synthetic hydroxyapatite compounds include high cost and decreased availability, especially for veterinary medicine purposes. Additionally, it is thought that HA biocompatibility and bioactivity could be enhanced by the addition of metal compounds. The objective of this work was to compare the subcutaneous tissue response of commercial and engineered hydroxyapatite obtained from the bovine femur diaphysis mixed with different concentrations of hexa-hydrated Zinc Nitrate in rabbits. Twenty-Five New Zealand female rabbits were used. Five treatments were done according to HA composition (commercial HA, no Zn-HA, 0.1M Zn, 0.2M Zn, and 0.3M Zn). Each treatment was evaluated at five time-points (8, 15, 30, 60 and 90 days post-implantation). Histopathologic analysis was performed to assess inflammation by polymorphonuclear cells infiltration, neovascularization, and fibrosis. Results obtained in this work suggest that general inflammation decreased after 60 days of implantation regardless of Zn concentration. Fibrosis score was increased in the commercial HP compared to control and Zn-hydrated HA. This paper shows that bovine hydroxyapatite is a biocompatible material regardless of nitrate Zinc concentration and has the same properties of commercial hydroxyapatite.(AU)

A hidroxiapatita (HA) é amplamente utilizada como biomaterial para reparo ósseo e revestimento de próteses metálicas. As principais limitações dos atuais compostos comerciais de hidroxiapatita sintética incluem alto custo e menor disponibilidade, especialmente para fins de medicina veterinária. Além disso, acredita-se que a biocompatibilidade e a bioatividade da HA poderiam ser aumentadas pela adição de compostos metálicos. O objetivo deste trabalho foi comparar a resposta tecidual subcutânea de hidroxiapatita comercial e da obtida da diáfise do fêmur bovino misturada com diferentes concentrações de nitrato de zinco hexa-hidratado em coelhos. Foram utilizadas 25 coelhas fêmeas Nova Zelândia. Cinco tratamentos foram feitos de acordo com os compostos de HA (HA comercial, no Zn-HA, 0,1M Zn, 0,2M Zn e 0,3M Zn). Cada tratamento foi avaliado em cinco momentos (oito, 15, 30, 60 e 90 dias após a implantação). A análise histopatológica foi realizada para avaliar a inflamação por infiltração de células polimorfonucleares, neovascularização e fibrose. Os resultados obtidos neste trabalho sugerem que a inflamação geral diminuiu após 60 dias de implantação, independentemente da concentração de Zn. O escore de fibrose foi aumentado na HA comercial comparada com o controle e com a HA hidratada com Zn. Este trabalho mostra que a hidroxiapatita bovina é um material biocompatível independentemente da concentração de nitrato de zinco e possui as mesmas propriedades da hidroxiapatita comercial.(AU)

Renal transplantation program in Cuba.

Kidney transplantation has been performed in Cuba since 1970. In 1979, compatible living-related donors were introduced into our renal transplantation program. There are 43 hospitals distributed around the country with a multidisciplinary group that attends cadaveric donors with encephalic death. The donor rate in Cuba oscillates between 15 and 18 per million; 90% of them are from cadaveric donors. This program includes 47 dialysis centers throughout the country with 2300 patients as supported by a National Coordinating Center at The Nephrology Institute. Cuba is one of the first countries in our region with this experience.

Human papillomavirus type 16 variants isolated from vulvar Bowenoid papulosis.

Tissues from two cases of Bowenoid papulosis of the vulva were found to contain human papillomavirus (HPV) 16 DNA by Southern blot hybridization. Analysis of the hybridization pattern revealed differences in a restriction fragment of one specimen as compared to the HPV 16 DNA prototype. To investigate if these differences could interfere with the expression of such oncogenic viral genomes, the corresponding DNA fragments were cloned and further analyzed. After amplification by PCR and DNA sequencing, a 213 base pairs duplication was mapped in the long control region (LCR) of this HPV 16 variant. One single PCR fragment was obtained from the other Bowenoid papulosis, which is identical in size with the same region in the HPV-16 prototype. The duplication in the HPV-16 LCR analyzed in this study maps upstream of a region containing several regulatory elements.