No contribution of GSTM1 and GSTT1 null genotypes to the risk of neutropenia due to benzene exposure in Southeastern Brazil

Exposure to benzene has been associated with haematological diseases such as neutropenia (NEB) and acute myeloid leukaemia (AML). We tested whether the null genotypes of the GSTM1 and GSTT1 genes, involved in benzene inactivation, altered the risk for NEB in southeastern Brazil. Genomic DNA from 55 NEB patients and 330 controls was analysed by multiplex-polymerase chain reaction. The frequency of the GSTM1, GSTT1 and combined null genotypes was similar in patients and controls (GSTM1, 27.3% vs. 38.8%, p = 0.16; GSTT1, 25.5% vs. 19.7%, p = 0.24; GSTM1/GSTT1, 12.7% vs. 6.7%, p = 0.26; respectively). The distribution of genotype classes in NEB patients was similar to normal controls, suggesting that GSTM1 and GSTT1 null genotypes make no specific contribution to the risk of NEB. As the GSTM1 and GSTT1 null genotypes were previously associated with increased risk for AML in Brazil and elsewhere, we hypothesise that different thresholds of chemical exposure relative to distinct GSTM1 and GSTT1 genotypes may determine whether AML or NEB manifests in benzene exposed individuals from southeastern Brazil. Although indicative, our results still require support by prospective and large scale epidemiological studies, with rigorous assessment of daily chemical exposures and control of the possible contribution of other polymorphic genes involved in benzene metabolism

Adverse Events Related to the Use of Central Venous Catheters in Hospitalized Newborns

This study identifies the adverse events related to the use of central venous catheters (CVC) in newborns admitted to a neonatal care unit. This is a quantitative, descriptive and retrospective study. The population consisted of 167 newborns admitted in the neonatal unit of the Hospital de Clínicas at Porto Alegre, RS, Brazil which used CVCs inserted through percutaneous puncture (PICC) and surgical insertion, totaling 241 catheters. There was a higher prevalence of mechanical adverse events in the PICC line insertions, with a preponderance of catheter occlusions (19.44%) and ruptures (8.8%). The surgically inserted CVCs had a higher prevalence of catheter-related infectious adverse events with the most common being clinical sepsis (16%). This study suggests that the correct insertion technique should be used and a specialized team should monitor the CVCs to ensure safety and prevent adverse events.El objetivo de este estudio fue identificar los eventos adversos relacionados con el uso de catéteres venosos centrales (CVC), en recién nacidos internados en una unidad neonatal. Se trata de investigación cuantitativa, descriptiva, retrospectiva. La población fue constituida por 167 neonatos internados en la unidad neonatal del Hospital de Clínicas de Porto Alegre que utilizaron CVCs, inseridos por punción percutánea (PICC) e inserción quirúrgica, totalizando 241 catéteres. En los PICCs hubo mayor incidencia de eventos adversos mecánicos, predominando la oclusión (19,44%) y la ruptura del catéter (8,8%). Los CVCs por inserción quirúrgica presentaron la mayor incidencia de los eventos adversos infecciosos relacionados al catéter, siendo el más frecuente la sepsis clínica (16%). El estudio sugiere que, para mayor seguridad del uso de CVCs, es importante que sea utilizada la técnica correcta de inserción del catéter y realizado el acompañamiento de los CVCs por un equipo especializado y atento a la prevención de eventos adversos.O objetivo deste estudo foi identificar os eventos adversos relacionados ao uso de cateteres venosos centrais (CVC), em recém-nascidos internados em unidade neonatal. Trata-se de pesquisa quantitativa, descritiva, retrospectiva. A população foi constituída por 167 neonatos internados na unidade neonatal do Hospital de Clínicas de Porto Alegre que utilizaram CVCs, inseridos por punção percutânea (PICC) e inserção cirúrgica, totalizando 241 cateteres. Nos PICCs houve maior prevalência de eventos adversos mecânicos, predominando a oclusão (19,44%) e a ruptura do cateter (8,8%). Os CVCs por inserção cirúrgica apresentaram maior prevalência dos eventos adversos infecciosos relacionados ao cateter, sendo o mais frequente a sepse clínica (16%). O estudo sugere que, para maior segurança do uso de CVCs, é importante que seja utilizada a técnica correta de inserção do cateter e realizado o acompanhamento dos CVCs por equipe especializada e atenta para a prevenção de eventos adversos

Structuring of Bacterioplankton Diversity in a Large Tropical Bay

Structuring of bacterioplanktonic populations and factors that determine the structuring of specific niche partitions have been demonstrated only for a limited number of colder water environments. In order to better understand the physical chemical and biological parameters that may influence bacterioplankton diversity and abundance, we examined their productivity, abundance and diversity in the second largest Brazilian tropical bay (Guanabara Bay, GB), as well as seawater physical chemical and biological parameters of GB. The inner bay location with higher nutrient input favored higher microbial (including vibrio) growth. Metagenomic analysis revealed a predominance of Gammaproteobacteria in this location, while GB locations with lower nutrient concentration favored Alphaproteobacteria and Flavobacteria. According to the subsystems (SEED) functional analysis, GB has a distinctive metabolic signature, comprising a higher number of sequences in the metabolism of phosphorus and aromatic compounds and a lower number of sequences in the photosynthesis subsystem. The apparent phosphorus limitation appears to influence the GB metagenomic signature of the three locations. Phosphorus is also one of the main factors determining changes in the abundance of planktonic vibrios, suggesting that nutrient limitation can be observed at community (metagenomic) and population levels (total prokaryote and vibrio counts)