Immobilization of PR4A3 enzyme in pluronic F127 polymeric micelles against colorectal adenocarcinoma cells and increase of in vitro bioavailability.

Traditional therapy for malignant neoplasms involving surgical procedures, radiotherapy and chemotherapy aims to kill neoplastic cells, but also affects normal cells. Therefore, exogenous proteases are the target of studies in cancer therapy, as they have been shown to be effective in suppressing tumors and reducing metastases. Pluronic F127 (F127) is a copolymer of amphiphilic blocks that has shown significant potential for drug administration, as it is capable of incorporating hydrophobic drugs and self-assembling in micrometers of nanometric size. This study investigated the effects of immobilization of the alkaline protease PR4A3 with pluronic F127 micelles on the enzyme-induced cytotoxicity. Protease immobilization was demonstrated through UV-visible and circular dichroism (CD) spectroscopies, as the enzyme interacts with the polymeric micelle of Pluronic F127 without changing its secondary structure. In addition, the immobilized form of the enzyme showed greater bioavailability after passing through the simulated gastrointestinal transit. Cell viability was assessed using the tetrazoic methylthiazole (MTT) assay. The results open perspectives for new research and development for PR4A3 in the treatment of colorectal carcinoma.

Biotechnological potential of mangrove sediments: Identification and functional attributes of thermostable and salinity-tolerant ß-glucanase.

Microorganisms native to mangroves are expected to contain enzymes capable of hydrolyzing different carbon sources. However, most of these microorganisms aren't cultivable; hence, alternative techniques as metagenomics are tools for studying and obtaining some of the natural genomes, genes and enzymes of biotechnological interest. The ß-glucanase was produced using a metagenomic clone of mangrove sediments and detected by functional screening on carboxymethylcellulose substrate. The enzyme was purified by cation exchange chromatography. The peptides detected by mass spectrometry showed 20% identity with the polypeptide deduced from the genomic fragment sequenced. The ORF identified as BglfosD9 possessed 729 bp and the encoded protein showed predicted MW and pI of 28kD and 6.8, respectively. The enzyme was active in a wide range of pH (5-10) with optimum pH at 8, had relative activity greater than 50% at all temperatures tested (5-90 °C), was stable at temperatures of 5, 50 and 90 °C and showed excellent relative activity at high NaCl concentrations. This ß-glucanase also showed high relative activity in the presence of SDS and it could hydrolyze ß-glucan, CMC and Avicel as substrates. These findings support the idea of a new thermostable and active enzyme at basic pH from metagenomic library of mangrove sediment.

Purple Sulfur Bacteria Dominate Microbial Community in Brazilian Limestone Cave.

The mineralogical composition of caves makes the environment ideal for inhabitation by microbes. However, the bacterial diversity in the cave ecosystem remains largely unexplored. In this paper, we described the bacterial community in an oxic chamber of the Sopradeira cave, an iron-rich limestone cave, in the semiarid region of Northeast Brazil. The microbial population in the cave samples was studied by 16S rDNA next-generation sequencing. A type of purple sulfur bacteria (PSB), Chromatiales, was found to be the most abundant in the sediment (57%), gravel-like (73%), and rock samples (96%). The predominant PSB detected were Ectothiorhodospiraceae, Chromatiaceae, and Woeseiaceae. We identified the PSB in a permanently aphotic zone, with no sulfur detected by energy-dispersive X-ray (EDX) spectroscopy. The absence of light prompted us to investigate for possible nitrogen fixing (nifH) and ammonia oxidizing (amoA) genes in the microbial samples. The nifH gene was found to be present in higher copy numbers than the bacterial-amoA and archaeal-amoA genes, and archaeal-amoA dominated the ammonia-oxidizing community. Although PSB dominated the bacterial community in the samples and may be related to both nitrogen-fixing and ammonia oxidizing bacteria, nitrogen-fixing associated gene was the most detected in those samples, especially in the rock. The present work demonstrates that this cave is an interesting hotspot for the study of ammonia-oxidizing archaea and aphotic PSB.

Perspectivas da gestão local do desenvolvimento econômico: as experiências de Salvador e Porto Alegre / Perspectives for local management of economic development: the experiences of Salvador and Porto Alegre

Discute quais as perspectivas da gestão local do desenvolvimento econômico no Brasil. Entra nas seguintes questões: a direção das iniciativas economicas que vêm sendo adotadas; o lugar que tais iniciativas ocupam no conjunto das políticas municipais; os instrumentos de que dispõe o governo local para atuar neste âmbito. Analisa as experiências de Salvador e Porto Alegre, na década de 1990. Faz uma breve revisão da literatura sobre o tema. Exibe as visões do desenvolvimento local assumidas pelos governos, em cada uma das cidades. Enfatiza os enfoques dados às questões da exclusão social e da competitividade urbana. Discute as diferenças de enfoque e evidência que, apesar das limitações, novos e antigos instrumentos podem ser utilizados na gestão local do desenvolvimento econômico.

Gestão contemporânea: cidades estratégicas e organizações locais / Contemporary management: strategic cities and local organizations

Discute as dimensões teóricas e metodológicas da complexidade local e dos ideários de desenvolvimento que articulam dimensões sociais e globais. Focaliza as organizações, em transição para novas configurações, e a construção de identidade a partir de valores étnico-culturais. Destaca as estratégias de gestão local, que incluem a gestão de serviços e a melhoria da qualidade de vida urbana (AU)