Molecular description of α-keto-based inhibitors of cruzain with activity against Chagas disease combining 3D-QSAR studies and molecular dynamics.

In this work, a group of α-keto-based inhibitors of the cruzain enzyme with anti-chagas activity was selected for a three-dimensional quantitative structure-activity relationship study (3D-QSAR) combined with molecular dynamics (MD). Firstly, statistical models based on Partial Least Square (PLS) regression were developed employing comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) descriptors. Validation parameters (q2 and r2 )for the models were, respectively, 0.910 and 0.997 (CoMFA) and 0.913 and 0.992 (CoMSIA). In addition, external validation for the models using a test group revealed r2pred  = 0.728 (CoMFA) and 0.971 (CoMSIA). The most relevant aspect in this study was the generation of molecular fields in both favorable and unfavorable regions based on the models developed. These fields are important to interpret modifications necessary to enhance the biological activities of the inhibitors. This analysis was restricted considering the inhibitors in a fixed conformation, not interacting with their target, the cruzain enzyme. Then, MD was employed taking into account important variables such as time and temperature. MD helped describe the behavior of the inhibitors and their properties showed similar results as those generated by QSAR-3D study.

Realinhamento das cabeças metatarsais no tratamento do antepé reumatóide: correçäo modificada do primeiro raio / Metarsal head resection for rheumatoid forefoot: first ray modified correction

Foram estudados 18 pés (dez pacientes), submetidos à ressecçao das cabeças metatarsais para o tratamento do antepé reumatóide por via plantar. O encurtamento do primeiro raio foi feito na base por meio de osteotomia do tipo trapezoidal. Esta modificaçao mostrou-se vantajosa por preservar a cabeça do primeiro MT, além de corrigir o varismo entre o primeiro e segundo raios. Com este procedimento obtiveram-se 50 por cento de excelentes resultados, 35 por cento foram considerados bons e 15 por cento avaliados como maus.

Hallux varus: tratamento cirúrgico pela transferência do hemitendäo extensor do 2o. artelho e osteotomia da falange proximal do hálux / Hallux varus: surgical treatment through transfer of the 2nd toe hemitendon extensor and osteotomy of the hallux proximal phalanx

Os autores apresentam a classificaçäo do "hallux varus" com revisäo da literatura. Sugerem técnica cirúrgica para os casos de "hallux varus" adquiridos, pela transferência do hemitendäo extensor do 2§ artelho e osteotomia valgizante da falange proximal do hálux. Säo relatados cinco casos.