New Insights into the Evolution of Metazoan Tyrosinase Gene Family

Tyrosinases, widely distributed among animals, plants and fungi, are involved in the biosynthesis of melanin, a pigment that has been exploited, in the course of evolution, to serve different functions. We conducted a deep evolutionary analysis of tyrosinase family amongst metazoa, thanks to the availability of new sequenced genomes, assessing that tyrosinases (tyr) represent a distinctive feature of all the organisms included in our study and, interestingly, they show an independent expansion in most of the analyzed phyla. Tyrosinase-related proteins (tyrp), which derive from tyr but show distinct key residues in the catalytic domain, constitute an invention of chordate lineage. In addition we here reported a detailed study of the expression territories of the ascidian Ciona intestinalis tyr and tyrps. Furthermore, we put efforts in the identification of the regulatory sequences responsible for their expression in pigment cell lineage. Collectively, the results reported here enlarge our knowledge about the tyrosinase gene family as valuable resource for understanding the genetic components involved in pigment cells evolution and development

A randomized clinical trial of oral steroids for ulnar neuropathy in type 1 and type 2 leprosy reactions Ensaio clínico sobre o tratamento com esteróides via oral da neuropatia ulnar em reação tipo 1 e tipo 2 da hanseníase

BACKGROUND: Steroids regimens in leprosy neuropathies are still controversial in botth types of reactions. METHOD: For this trial, 21 patients with ulnar neuropathy were selected from 163 leprosy patients, 12 with type 1 reaction (T1R) and nine with type 2 (T2R). One experimental group started with prednisone 2 mg/kg/day and the control group with 1 mg/kg/day. A clinical score based on tests for spontaneous pain, nerve palpation, sensory and muscle function was used. Neurophysiological evaluation consisted on the motor nerve conduction of the ulnar nerve in three segments. Student "t" test for statistical analysis was applied on the results: before treatment, first week, first month and sixth month, between each regimen and types of reaction. CONCLUSION: In both reactions during the first month higher doses of steroids produced better results but, earlier treatment with lower dose was as effective. Short periods of steroid, 1 mg/Kg/day at the beginning and,tapering to 0,5 mg/Kg/day or less in one month turned out to be efficient in T2R.<br>INTRODUÇÃO: O tratamento da neuropatia da hanseníase com esteróides é ainda controverso nos dois tipos de reações. MÉTODO: Neste ensaio, de 163 pacientes foram selecionados 21 com neuropatia ulnar, 12 com reação tipo 1 e 9 com tipo 2. Um grupo experimental iniciou com 2 mg/kg/dia e o grupo controle com 1 mg/kg/dia. Foi composto um escore clínico pela avaliação da sensação dolorosa espontânea, palpação de nervos e funções sensitiva e motora. Realizou-se a condução nervosa motora do nervo ulnar em três segmentos. Aplicaram-se os estudos estatísticos com o teste t de Student nos resultados: antes do tratamento, primeira semana, primeiro mês e sexto mês. CONCLUSÃO: Em ambas as reações dosagens mais elevadas iniciais produziram melhores resultados, mas a dose menor quando administrada precocemente foi igualmente efetiva. Períodos curtos com doses efetivas, 1 mg/Kg/dia no início e reduzindo-se para 0,5 mg/Kg/dia ou menos em um mês foram eficientes na reação tipo 2