Different evolutionary histories of two cation/proton exchanger gene families in plants.

BACKGROUND: Gene duplication events have been proposed to be involved in the adaptation of plants to stress conditions; precisely how is unclear. To address this question, we studied the evolution of two families of antiporters. Cation/proton exchangers are important for normal cell function and in plants, Na+,K+/H+ antiporters have also been implicated in salt tolerance. Two well-known plant cation/proton antiporters are NHX1 and SOS1, which perform Na+ and K+ compartmentalization into the vacuole and Na+ efflux from the cell, respectively. However, our knowledge about the evolution of NHX and SOS1 stress responsive gene families is still limited. RESULTS: In this study we performed a comprehensive molecular evolutionary analysis of the NHX and SOS1 families. Using available sequences from a total of 33 plant species, we estimated gene family phylogenies and gene duplication histories, as well as examined heterogeneous selection pressure on amino acid sites. Our results show that, while the NHX family expanded and specialized, the SOS1 family remained a low copy gene family that appears to have undergone neofunctionalization during its evolutionary history. Additionally, we found that both families are under purifying selection although SOS1 is less constrained. CONCLUSIONS: We propose that the different evolution histories are related with the proteins' function and localization, and that the NHX and SOS1 families are examples of two different evolutionary paths through which duplication events may result in adaptive evolution of stress tolerance.

Transgenic Hypericum perforatum.

Plant transformation is an important tool with many applications in modern plant biology. Although this technique is primarily used to produce superior crop varieties, it is also being utilized to answer basic questions concerning gene function and regulation in contemporary functional genomics research. In our laboratory, we have established a transformation system for Hypericum perforatum. This protocol involves the transfer of foreign DNA into H. perforatum organogenic nodule explants via particle-bombardment and the regeneration of shoots from the explants under selection pressure. We have successfully used this method to express ss-glucuronidase and hygromycin phosphotransferase genes in H. perforatum. Molecular analyses of putative phenotypically normal transgenic plants show stable integration of the transgenes into the plant nuclear genome. Here we describe the procedure for the transformation of H. perforatum.

[Diabetic foot infection. Bacteriologic analysis of 141 patients]. / Pé diabético: análise bacteriológica de 141 casos.

Diabetes mellitus (DM) is a progressive disease with chronic complications. Feet problems represent one of the most important complications. In a prospective study, we analyzed 298 species of bacteria isolated from 141 patients with community-acquired diabetic foot ulcers. The study was undertaken at a diabetic center and at the Federal University of Ceará, Brazil, from March/2000 to November/2001. The majority of patients had mild to moderate infections and was classified as Wagner's grades I and II. The samples were cultured using selective media. The identification and the susceptibility tests were done by conventional and automated methods. The most frequently occurring pathogens were Enterobacteriaceae (83.7%), Staphylococcus aureus (43.3%) and anaerobic bacteria (17%). Streptococcus pyogenes was recovered from 7.8% of the patients. ESBL producing strains were detected in 6% and methicillin resistant Staphylococcus aureus strains were recovered from 11.6% of the patients. Resistance among bacteria has increased largely, and became common even in community-acquired infections. Improvements in the routine etiologic diagnostics and antibiotic use strategies are required to avoid inadequate treatment and its well known dramatic consequences.

Pé diabético: análise bacteriológica de 141 casos / Diabetic foot infection: bacteriologic analysis of 141 patients

Diabetes mellitus (DM) é uma doença progressiva que apresenta complicações freqüentes, em especial a infecção nos pés. Realizamos um estudo prospectivo com 141 pacientes com DM e úlceras infectadas nos pés, conduzido no Centro Integrado de Diabetes e Hipertensão da UFC no período de março/2000 a novembro/2001. A maioria apresentava infecção avaliada como graus I e II da classificação de Wagner. As amostras foram cultivadas utilizando-se meios seletivos, e a identificação bacteriana e os antibiogramas foram realizados através de metodologia convencional e automatizados. Os patógenos mais freqüentemente isolados foram as enterobactérias (83,7 por cento), Staphylococcus aureus (43,3 por cento) e bactérias anaeróbias (17 por cento). Cepas de Streptococcus pyogenes foram isoladas de 7,8 por cento dos pacientes. Cepas produtoras de beta-lactamase de espectro ampliado e cepas de Staphylococcus aureus resistentes à oxacilina foram isoladas de 6 por cento e 11,6 por cento dos pacientes, respectivamente. A resistência aos antimicrobianos vem se tornando cada vez mais comum, mesmo em pacientes com infecção adquirida na comunidade. Investimentos em diagnóstico etiológico das infecções e estratégias racionais no uso de antimicrobianos fazem-se necessários na tentativa de evitar tratamentos inadequados e suas já conhecidas conseqüências.

Avaliação de risco potencial para estabelecimentos processadores de alimentos artesanais / Evaluation of potential risk to food processors craft establishments

A exigência de Boas Práticas de Fabricação ao longo da cadeia produtiva na produção de alimentos tem procurado garantir melhor qualidade e segurança. Com o presente trabalho, objetivou-se avaliar o potencial de risco de estabelecimentos processadores de alimentos artesanais. Foram aplicados questionários num total de 20 estabelecimentos produtores de queijo minas frescal, rapadura, farinha de mandioca e doces na região do Alto Jequitinhonha. As perguntas eram pertinentes à avaliação das condições de infra-estrutura, higienização e processamento adotados nas unidades de produção artesanal. Para a produção de farinha de mandioca, rapadura e doces, os estabelecimentos foram considerados de Alto Risco. O maior risco estava nas instalações e nos manipuladores de alimentos, que não atenderam aos itens considerados imprescindíveis no processamento dos alimentos. Nas avaliações das queijarias, observou-se que se apresentavam dentro dos padrões recomendados. Em 100% dos estabelecimentos não realizavam nenhum controle de qualidade do processo. Portanto para minimizar os riscos e garantir a obtenção de alimentos dentro dos padrões de qualidade e segurança é fundamental a adoção de sistemas e programas de controle.