Phylogenomic analysis sheds light on the evolutionary pathways towards acoustic communication in Orthoptera

Acoustic communication is enabled by the evolution of specialised hearing and sound producing organs. In this study, we performed a large-scale macroevolutionary study to understand how both hearing and sound production evolved and affected diversification in the insect order Orthoptera, which includes many familiar singing insects, such as crickets, katydids, and grasshoppers. Using phylogenomic data, we firmly establish phylogenetic relationships among the major lineages and divergence time estimates within Orthoptera, as well as the lineage-specific and dynamic patterns of evolution for hearing and sound producing organs. In the suborder Ensifera, we infer that forewing-based stridulation and tibial tympanal ears co-evolved, but in the suborder Caelifera, abdominal tympanal ears first evolved in a non-sexual context, and later co-opted for sexual signalling when sound producing organs evolved. However, we find little evidence that the evolution of hearing and sound producing organs increased diversification rates in those lineages with known acoustic communication

Tumores malignos de cabeça e pescoço em pacientes com menos de 18 anos de idade

A conduta ideal para os pacientes menores de 18 anos portadores de tumores malignos da região de cabeça e pescoço não é uniforme nos escassos relatos de literatura. Com o objetivo de mostrar e discutir a experiência no atendimento de cinqüenta casos tratados no Serviço de Cirurgia de Cabeça e Pescoço do Complexo Hospitalar Heliópolis, no período de 1978 a 1994, os autores procederam a uma análise retrospectiva de sua casuística. Os tipos histológicos mais freqüentes foram os derivados da linhagem epitelial, 24 casos (48%) e, entre eles, o carcinoma mucoepidermóide. Entre os tumores derivados do tecido mensequimal, os mais freqüentes foram o rabdomiossarcoma e os linfomas. A cavidade oral foi o sítio mais freqüentemente acometido (15 casos, 30%). Entre todos os pacientes, apenas 21 (42%) estavam vivos e sem evidência de doença em atividade por um período que variou de seis meses a 18 anos. Quatorze (28%) pacientes morreram em decorrência de doença não controlada após um período que variou de dez dias a dois anos a contar da data do final do tratamento. De quatorze (28%) pacientes não pudemos obter informações atualizadas de suas condições e foram considerados perdidos de seguimento. Estes tumores não devem ser vistos como neoplasias de adultos localizadas em pacientes pediátricos; devem ser estudados e abordados como uma doença que apresenta características próprias e que exigem, como no adulto, que a primeira intervenção para o diagnóstico ou para o tratamento não seja intempestiva e, de fato, tenha resolubilidade

PDGF-BB Does Not Accelerate Healing in Diabetic Mice with Splinted Skin Wounds

Topical application of platelet-derived growth factor-BB (PDGF-BB) is considered to accelerate tissue repair of impaired chronic wounds. However, the vast literature is plagued with conflicting reports of its efficacy in animal models and this is often influenced by a wide array of experimental variables making it difficult to compare the results across the studies. To mitigate the confounding variables that influence the efficacy of topically applied PDGF-BB, we used a controlled full thickness splinted excisional wound model in db/db mice (type 2 diabetic mouse model) for our investigations. A carefully-defined silicone-splinted wound model, with reduced wound contraction, controlled splint and bandage maintenance, allowing for healing primarily by reepithelialization was employed. Two splinted 8 mm dorsal full thickness wounds were made in db/db mice. Wounds were topically treated once daily with either 3 µg PDGF-BB in 30 µl of 5% PEG-PBS vehicle or an equal volume of vehicle for 10 days. Body weights, wound contraction, wound closure, reepithelialization, collagen content, and wound bed inflammation were evaluated clinically and histopathologically. The bioactivity of PDGF-BB was confirmed by in vitro proliferation assay. PDGF-BB, although bioactive in vitro, failed to accelerate wound healing in vivo in the db/db mice using the splinted wound model. Considering that the predominant mechanism of wound healing in humans is by re-epithelialization, the most appropriate model for evaluating therapeutics is one that uses splints to prevent excessive wound contraction. Here, we report that PDGF-BB does not promote wound closure by re-epithelialization in a murine splinted wound model. Our results highlight that the effects of cytoactive factors reported in vivo ought to be carefully interpreted with critical consideration of the wound model used