An end-joining repair mechanism in Escherichia coli

Bridging broken DNA ends via nonhomologous end-joining (NHEJ) contributes to the evolution and stability of eukaryote genomes. Although some bacteria possess a simplified NHEJ mechanism, the human commensal Escherichia coli is thought to rely exclusively on homology-directed mechanisms to repair DNA double-strand breaks (DSBs). We show here that laboratory and pathogenic E. coli strains possess a distinct end-joining activity that repairs DSBs and generates genome rearrangements. This mechanism, named alternative end-joining (A-EJ), does not rely on the key NHEJ proteins Ku and Ligase-D which are absent in E. coli. Differently from classical NHEJ, A-EJ is characterized by extensive end-resection largely due to RecBCD, by overwhelming usage of microhomology and extremely rare DNA synthesis. We also show that A-EJ is dependent on the essential Ligase-A and independent on Ligase-B. Importantly, mutagenic repair requires a functional Ligase-A. Although generally mutagenic, accurate A-EJ also occurs and is frequent in some pathogenic bacteria. Furthermore, we show the acquisition of an antibiotic-resistance gene via A-EJ, refuting the notion that bacteria gain exogenous sequences only by recombination-dependent mechanisms. This finding demonstrates that E. coli can integrate unrelated, nonhomologous exogenous sequences by end-joining and it provides an alternative strategy for horizontal gene transfer in the bacterial genome. Thus, A-EJ contributes to bacterial genome evolution and adaptation to environmental challenges. Interestingly, the key features of A-EJ also appear in A-NHEJ, an alternative end-joining mechanism implicated in chromosomal translocations associated with human malignancies, and we propose that this mutagenic repair might have originated in bacteria.     

Management of animal bites within the area of Ascoli Piceno,Marches Region,Italy (2000-2001)

During the years 2000-2001, 284 cases of animal-bite injuries were reported to the Public Health Service of Ascoli Piceno, Marches Region, Italy. The authors have described the ways in which the accidents occurred as well as the clinical and prophylactic measures adopted. Dogs have shown to be responsible for most bites (87.4%) and limbs were the most frequent sites involved (82%). One third of the patients were submitted to antibiotic treatment and 13% of them had their injuries sutured. On veterinary assessment, rabic conditions were ruled out in all the animals observed. The study stresses the importance to actively offer tetanus vaccination services in these circumstances.     

Efficacy of novel recombinant fowlpox vaccine against recent Mexican H7N3 highly pathogenic avian influenza virus

Since 2012, H7N3 highly pathogenic avian influenza (HPAI) has produced negative economic and animal welfare impacts on poultry in central Mexico. In the present study, chickens were vaccinated with two different recombinant fowlpox virus vaccines (rFPV-H7/3002 with 2015 H7 hemagglutinin [HA] gene insert, and rFPV-H7/2155 with 2002 H7 HA gene insert), and were then challenged three weeks later with H7N3 HPAI virus (A/chicken/Jalisco/CPA-37905/2015). The rFPV-H7/3002 vaccine conferred 100% protection against mortality and morbidity, and significantly reduced virus shed titers from the respiratory and gastrointestinal tracts. In contrast, 100% of sham and rFPV-H7/2155 vaccinated birds shed virus at higher titers and died within 4?days. Pre- (15/20) and post- (20/20) challenge serum of birds vaccinated with rFPV-H7/3002 had antibodies detectable by hemagglutination inhibition (HI) assay using challenge virus antigen. However, only a few birds (3/20) in the rFPV-H7/2155 vaccinated group had antibodies that reacted against the challenge strain but all birds had antibodies that reacted against the homologous vaccine antigen (A/turkey/Virginia/SEP-66/2002) (20/20). One possible explanation for differences in vaccines efficacy is the antigenic drift between circulating viruses and vaccines. Molecular analysis demonstrated that the Mexican H7N3 strains have continued to rapidly evolve since 2012. In addition, we identified in silico three potential new N-glycosylation sites on the globular head of the H7 HA of A/chicken/Jalisco/CPA-37905/2015 challenge virus, which were absent in 2012 H7N3 outbreak virus. Our results suggested that mutations in the HA antigenic sites including increased glycosylation sites, accumulated in the new circulating Mexican H7 HPAIV strains, altered the recognition of neutralizing antibodies from the older vaccine strain rFPV-H7/2155. Therefore, the protective efficacy of novel rFPV-H7/3002 against recent outbreak Mexican H7N3 HPAIV confirms the importance of frequent updating of vaccines seed strains for long-term effective control of H7 HPAI virus.     

Anti-inflammatory activity of Agaricus blazei in different basidiocarp maturation phases

Agaricus blazei Murrill ss. Heinemann (Agaricus brasiliensis Wasser et al.; Agaricus subrufescens Peck) has raised interest in the scientific community due to its therapeutic properties. Although there are numerous studies about this fungus a few of them study the anti-inflammatory activity and the relationship with basidiocarp development phases. Thus, the objective of this study was to evaluate the effect of A. blazei extracts of closed and opened basidiocarp on the cell migration of rats submitted to an inflammatory challenge. The basidiocarp extracts were administered by gavage at 55 or 110 mg/kg. The inflammatory challenge was performed by administering phlogistic agent (carrageenan 2%) in an air-pouch induced in the animal subcutaneous tissue. It was concluded that the extracts affect leukocyte mobilisation regulation; closed basidiocarp extract in doses of 55 and 110 mg/kg and opened basidiocarp extract in 110 mg/kg modulate the anti-inflammatory response.     

Relationship between Anthropometric Measures and Cardiovascular Risk Factors in Children and Adolescents

Background

Obesity has been identified as an important risk factor in the development of cardiovascular diseases; however, other factors, combined or not with obesity, can influence cardiovascular risk and should be considered in cardiovascular risk stratification in pediatrics.

Objective

To analyze the association between anthropometry measures and cardiovascular risk factors, to investigate the determinants to changes in blood pressure (BP), and to propose a prediction equation to waist circumference (WC) in children and adolescents.

Methods

We evaluated 1,950 children and adolescents, aged 7 to 18 years. Visceral fat was assessed by WC and waist hip relationship, BP and body mass index (BMI). In a randomly selected subsample of these volunteers (n = 578), total cholesterol, glucose and triglycerides levels were evaluated.

Results

WC was positively correlated with BMI (r = 0.85; p < 0.001) and BP (SBP r = 0.45 and DBP = 0.37; p < 0.001). Glycaemia and triglycerides showed a weak correlation with WC (r = 0.110; p = 0.008 e r = 0.201; p < 0.001, respectively). Total cholesterol did not correlate with any of the variables. Age, BMI and WC were significant predictors on the regression models for BP (p < 0.001). We propose a WC prediction equation for children and adolescents: boys: y = 17.243 + 0.316 (height in cm); girls: y = 25.197 + 0.256 (height in cm).

Conclusion

WC is associated with cardiovascular risk factors and presents itself as a risk factor predictor of hypertension in children and adolescents. The WC prediction equation proposed by us should be tested in future studies.     

Genetic heterogeneity of the excision repair defect associated with trichothiodystrophy

Trichothiodystrophy (TTD) is a rare autosomal recessive diseasecharacterized by brittle hair with reduced sulfur content, mentaland physical retardation, a peculiar face and ichthyosis. Photosensitivityhas been reported in     

Reservosomes: multipurpose organelles?

Reservosomes are endocytic organelles from Trypanosoma cruzi epimastigotes that store proteins and lipids for future use. The lack of molecular markers for the compartments of this parasite makes it difficult to clarify all reservosome functions, as they present characteristics of pre-lysosomes, lysosomes and recycling compartments.This review was presented at the International Symposium on Vesicle Trafficking in Parasitic Protozoa at Caxambu, Brasil, in November, 2005.     

Encouraging family engagement in the rehabilitation process: a rehabilitation provider's development of support strategies for family members of people with traumatic brain injury

Purpose: After a moderate to severe traumatic brain injury, it is widely recommended that family members be actively engaged in the client's rehabilitation journey because evidence suggests that this is associated with better outcomes. The ability of family members to fully engage in rehabilitation may be hindered by the barriers (logistical and psychological) they encounter. However, rehabilitation services can facilitate family engagement through a person-centred approach that provides support to remove barriers. Limited published guidance exists regarding practical and effective methods for delivering such support. This paper describes how one rehabilitation service has developed an eight-tiered approach. Key messages and implications: Family support is provided by explicit structuring of services to include (i) early engagement, (ii) meeting cultural needs, (iii) keeping families together, (iv) actively listening, (v) active involvement, (vi) education, (vii) skills training, and (viii) support for community re-integration. Implementation of these support strategies are individualised based on the expressed needs of each family. Families report a high level of satisfaction with the service. Conclusion: A practice-based quality improvement model identified challenges, implemented changes, and observed/evaluated the results to successfully develop a multifaceted strategy for supporting families, thereby encouraging their engagement in rehabilitation. Ongoing refinements and evaluation are planned. [Box: see text].