Biodegradation of mono-, di- and trifluoroacetate by microbial cultures with different origins

This work focused on the biodegradation of three structurally related fluoroacetates (FAs), mono- (MFA), di- (DFA) and trifluoroacetate (TFA), using as microbial inocula samples collected from a site with a long history of industrial contamination and activated sludge obtained from a municipal wastewater treatment plant. Biodegradation experiments were carried out under different modes of substrate supplementation, which included (i) FAs fed as sole carbon sources; (ii) FAs (only for DFA and TFA) fed in co-metabolism with sodium acetate; and (iii) mixtures of MFA with DFA or TFA. Biodegradation of the target compounds was assessed through fluoride ion release. Defluorination was obtained in the cultures fed with MFA, while DFA and TFA were recalcitrant in all tested conditions. When present in mixture, DFA was shown to inhibit biodegradation of MFA, while TFA had no effect. A total of 13 bacterial isolates obtained from MFA degrading cultures were found to degrade 20mgL-1 of this compound, as single strains, when supplemented as a sole carbon source. Sequencing of the 16S rRNA gene indicated that among these degrading bacteria only Delftia acidovorans had been previously reported to be able to degrade MFA. This work shows that, despite their similar chemical structures, biodegradation of the three tested FAs is very distinct and draws attention to the unknown impacts that the accumulation of DFA and TFA may have in the environment as a result of their high recalcitrance.info:eu-repo/semantics/publishedVersio

Molecular determinants of ligand specificity in family 11 carbohydrate binding modules - An NMR, X-ray crystallography and computational chemistry approach

12 pags, 6 figs, 1 tabThe direct conversion of plant cell wall polysaccharides into soluble sugars is one of the most important reactions on earth, and is performed by certain microorganisms such as Clostridium thermocellum (Ct). These organisms produce extracellular multi-subunit complexes (i.e. cellulosomes) comprising a consortium of enzymes, which contain noncatalytic carbohydrate-binding modules (CBM) that increase the activity of the catalytic module. In the present study, we describe a combined approach by X-ray crystallography, NMR and computational chemistry that aimed to gain further insight into the binding mode of different carbohydrates (cellobiose, cellotetraose and cellohexaose) to the binding pocket of the family 11 CBM. The crystal structure of C. thermocellum CBM11 has been resolved to 1.98 Å in the apo form. Since the structure with a bound substrate could not be obtained, computational studies with cellobiose, cellotetraose and cellohexaose were carried out to determine the molecular recognition of glucose polymers by CtCBM11. These studies revealed a specificity area at the CtCBM11 binding cleft, which is lined with several aspartate residues. In addition, a cluster of aromatic residues was found to be important for guiding and packing of the polysaccharide. The binding cleft of CtCBM11 interacts more strongly with the central glucose units of cellotetraose and cellohexaose, mainly through interactions with the sugar units at positions 2 and 6. This model of binding is supported by saturation transfer difference NMR experiments and linebroadening NMR studies. © 2008 The Authors.The authors would like to thank the research network REQUIMTE (Project Reqmol), as well as the Portuguese Science and Technology Foundation (FCT-MCTES), for financial support through projectPTDC⁄QUI⁄68286⁄2006 and scholarships SFRH⁄BPD⁄27237⁄2006 and SFRH⁄BD⁄31359⁄200

Team dynamics in emergency surgery teams: results from a first international survey

Background: Emergency surgery represents a unique context. Trauma teams are often multidisciplinary and need to operate under extreme stress and time constraints, sometimes with no awareness of the trauma\u2019s causes or the patient\u2019s personal and clinical information. In this perspective, the dynamics of how trauma teams function is fundamental to ensuring the best performance and outcomes. Methods: An online survey was conducted among the World Society of Emergency Surgery members in early 2021. 402 fully filled questionnaires on the topics of knowledge translation dynamics and tools, non-technical skills, and difficulties in teamwork were collected. Data were analyzed using the software R, and reported following the Checklist for Reporting Results of Internet E-Surveys (CHERRIES). Results: Findings highlight how several surgeons are still unsure about the meaning and potential of knowledge translation and its mechanisms. Tools like training, clinical guidelines, and non-technical skills are recognized and used in clinical practice. Others, like patients\u2019 and stakeholders\u2019 engagement, are hardly implemented, despite their increasing importance in the modern healthcare scenario. Several difficulties in working as a team are described, including the lack of time, communication, training, trust, and ego. Discussion: Scientific societies should take the lead in offering training and support about the abovementioned topics. Dedicated educational initiatives, practical cases and experiences, workshops and symposia may allow mitigating the difficulties highlighted by the survey\u2019s participants, boosting the performance of emergency teams. Additional investigation of the survey results and its characteristics may lead to more further specific suggestions and potential solutions

Infrequent p53 gene alterations in ulcerative colitis

The purpose of this study was to determine whether point mutations and loss of the p53 gene take place in ulcerative colitis which is histologically negative for dysplasia. DNA was extracted from 13 frozen rectal or colon biopsies and blood samples. Ulcerative colitis was classified histologically as active (10 cases) and inactive (3 cases). Exons 5-8 were amplified by PCR, treated with exonuclease and shrimp alkaline phosphatase and sequenced by the dideoxy chain termination method with the Sequenase Version 2.0 DNA sequencing kit. PCR products of intron 6 and exon 4 were digested with MspI and AccII, respectively, for RFLP analysis. No p53 gene mutation was detected in these cases. The number of informative patients for loss of heterozygosity (LOH) at the p53 intron 6 was high, 11 out of 12 (92%), whereas no LOH was observed. LOH affecting p53 exon 4 was not detected in lesions from 5 of 12 patients (42%). In ulcerative colitis, tumor progression is similar to that in sporadic colon cancer, and other oncogenes and tumor suppressor genes are likely to be mutated before the p53 gene

Hydrops fetalis and neonatal cholestasis – case report

As possíveis etiologias associadas a hidropisia fetal não imune e colestase neonatal são numerosas. A investigação destas situações, mesmo quando exaustiva, nem sempre permite estabelecer um diagnóstico etiológico. A abordagem clínica deverá assentar na exploração minuciosa dos dados da anamnese e do exame objectivo. A realização de exames complementares deve ser orientada pela clínica, tendo por objectivo identificar rapidamente os casos graves e as patologias potencialmente tratáveis. Os autores descrevem a abordagem diagnóstica e terapêutica de um recém-nascido admitido numa Unidade de Cuidados Intensivos Neonatais ao nascimento por hidropisia fetal e prematuridade, que desenvolveu um quadro de colestase a partir do 2º dia de vida. ABSTRACT There is a wide variety of disorders associated with non-immune hydrops fetalis and neonatal cholestasis. Besides exhaustive investigation, in some cases it is not possible to identify an etiological factor. The approach to these entities should be supported by detailed anamnesis and a meticulous physical examination. Additional testing must be oriented by clinical manifestations and the aim is prompt identification of potential lifethreatening diseases and treatable disorders. The authors present the diagnostic and therapeutic approaches in a premature newborn with hydrops fetalis, admitted in an Intensive Care Neonatal Unit soon after birth, who developed cholestasis from the 2nd day of life

Development of microsatellite loci for the black-footed limpet, Patella depressa, and cross-amplification in two other Patella species

Limpets (Patella spp.) are suitable organisms to investigate the effects of climate change in marine systems. They are widespread over NE Atlantic intertidal rocky shores and have been extensively studied in terms of population dynamics and ecology. Within genus Patella, microsatellites have only been developed for Patella caerulea and cross-species tests are unknown. In this work, we describe 11 primer pairs for Patella depressa and the results of cross-species testing on Patella candei and Patella rustica