8 research outputs found

    Azospirillum Genomes Reveal Transition of Bacteria from Aquatic to Terrestrial Environments

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    Fossil records indicate that life appeared in marine environments ∌3.5 billion years ago (Gyr) and transitioned to terrestrial ecosystems nearly 2.5 Gyr. Sequence analysis suggests that “hydrobacteria” and “terrabacteria” might have diverged as early as 3 Gyr. Bacteria of the genus Azospirillum are associated with roots of terrestrial plants; however, virtually all their close relatives are aquatic. We obtained genome sequences of two Azospirillum species and analyzed their gene origins. While most Azospirillum house-keeping genes have orthologs in its close aquatic relatives, this lineage has obtained nearly half of its genome from terrestrial organisms. The majority of genes encoding functions critical for association with plants are among horizontally transferred genes. Our results show that transition of some aquatic bacteria to terrestrial habitats occurred much later than the suggested initial divergence of hydro- and terrabacterial clades. The birth of the genus Azospirillum approximately coincided with the emergence of vascular plants on land

    Comparative Effects of Basic Fibroblast Growth Factor Delivery or Voluntary Exercise on Muscle Regeneration after Volumetric Muscle Loss.

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    Volumetric muscle loss (VML) is associated with irreversibly impaired muscle function due to traumatic injury. Experimental approaches to treat VML include the delivery of basic fibroblast growth factor (bFGF) or rehabilitative exercise. The objective of this study was to compare the effects of spatially nanopatterned collagen scaffold implants with either bFGF delivery or in conjunction with voluntary exercise. Aligned nanofibrillar collagen scaffold bundles were adsorbed with bFGF, and the bioactivity of bFGF-laden scaffolds was examined by skeletal myoblast or endothelial cell proliferation. The therapeutic efficacy of scaffold implants with either bFGF release or exercise was examined in a murine VML model. Our results show an initial burst release of bFGF from the scaffolds, followed by a slower release over 21 days. The released bFGF induced myoblast and endothelial cell proliferation in vitro. After 3 weeks of implantation in a mouse VML model, twitch force generation was significantly higher in mice treated with bFGF-laden scaffolds compared to bFGF-laden scaffolds with exercise. However, myofiber density was not significantly improved with bFGF scaffolds or voluntary exercise. In contrast, the scaffold implant with exercise induced more re-innervation than all other groups. These results highlight the differential effects of bFGF and exercise on muscle regeneration

    Estimating gestational age and its relation to the anthropometric status of newborns: a study comparing the Capurro and ultrasound methods with last menstrual period Estimativa da idade gestacional e sua relação com o estado antropomĂ©trico em recĂ©m-nascidos: uma comparação dos mĂ©todos Capurro e ultrassonogrĂĄfico com a data da Ășltima menstruação

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    OBJECTIVE: to assess the accuracy of the Capurro somatic and ultrasound methods, taking date of last menstruation as a reference point, for evaluating gestational age and anthropometric classification of term newborns. METHODS: a prevalence study was carried out involving 309 pregnant women and their term newborns, 92 of whom were small for gestational age and 217 appropriate sized for gestational age, at two public maternity hospitals in the Brazilian city of Salvador. The evaluation of the differences between the median gestational age according to the two methods was carried out using the non-parametric "Wilcoxon Signed-Rank Test." The accuracy of the methods for evaluating gestational age for the small for gestational age newborns was estimated by calculating the sensitivity, specificity, positive predictive value, negative predictive value and ROC (Receiver Operating Characteristic) curve. RESULTS: compared to ultrasound, the Capurro method overestimated the gestational age in newbornsof less than 39 weeks and underestimated it in older newborns. Ultrasound underestimated gestational agein newborns with more than 37 weeks. CONCLUSION: ultrasound was found to have greater sensitivity for prediction of small for age newborns (96.6%), while the Capurro method presented greater specificity (75.5%). The highest accuracy was obtained using ultrasound in the 41st gestational week (ROC=77.0%).<br>OBJETIVOS: avaliar a acurĂĄcia dos mĂ©todos fĂ­sico de Capurro e da ultrassonografia (USG), tomandocomo referĂȘncia o mĂ©todo da data da Ășltima menstruação (DUM), na avaliação da idade gestacional e classificação antropomĂ©trica de recĂ©m-nascidos (RN) a termo. MÉTODOS: estudo de prevalĂȘncia, envolvendo 309 puĂ©rperas e seus recĂ©m-nascidos a termo, sendo 92 pequenos para idade gestacional (PIG) e 217 adequados para idade gestacional (AIG), de duas maternidades pĂșblicas de Salvador. A avaliação das diferenças entre as medianas da idade gestacional segundo os mĂ©todos foi realizada utilizando-se o teste nĂŁo paramĂ©trico "Wilcoxon Signed-Rank Test." A acurĂĄcia dos mĂ©todos na avaliação da idade gestacional para o diagnĂłstico de RN PIG foi verificada atravĂ©s do cĂĄlculo da sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e curva ROC (Receiver Operating Characteristic). RESULTADOS: comparado Ă  ultrassonografia, o mĂ©todo de Capurro superestimou a idade gestacional em recĂ©m-natos menores de 39 semanas e substimou a naqueles acima deste patamar. A USG substimou aidade gestacional em recĂ©m-nascidos com mais de 37 semanas. CONCLUSÕES: na predição de RN PIG, maior sensibilidade foi observada para a USG (96,6%) e maior especificidade para o Capurro (75,5%). Melhor acurĂĄcia foi observada para a USG na 41ÂȘ semana gestacional (ROC=77,0%)
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