Background Escherichia coli strains adhere to the normally sterile human uroepithelium using type 1 pili, that are long, hairy surface organelles exposing a mannose-binding FimH adhesin at the tip. A small percentage of adhered bacteria can successfully invade bladder cells, presumably via pathways mediated by the high-mannosylated uroplakin-Ia and α3β1 integrins found throughout the uroepithelium. Invaded bacteria replicate and mature into dense, biofilm-like inclusions in preparation of fluxing and of infection of neighbouring cells, being the major cause of the troublesome recurrent urinary tract infections.Methodology/Principal FindingsWe demonstrate that α-d-mannose based inhibitors of FimH not only block bacterial adhesion on uroepithelial cells but also antagonize invasion and biofilm formation. Heptyl α-d-mannose prevents binding of type 1-piliated E. coli to the human bladder cell line 5637 and reduces both adhesion and invasion of the UTI89 cystitis isolate instilled in mouse bladder via catheterization. Heptyl α-d-mannose also specifically inhibited biofilm formation at micromolar concentrations. The structural basis of the great inhibitory potential of alkyl and aryl α-d-mannosides was elucidated in the crystal structure of the FimH receptor-binding domain in complex with oligomannose-3. FimH interacts with Manα1,3Manβ1,4GlcNAcβ1,4GlcNAc in an extended binding site. The interactions along the α1,3 glycosidic bond and the first β1,4 linkage to the chitobiose unit are conserved with those of FimH with butyl α-d-mannose. The strong stacking of the central mannose with the aromatic ring of Tyr48 is congruent with the high affinity found for synthetic inhibitors in which this mannose is substituted for by an aromatic group.Conclusions/SignificanceThe potential of ligand-based design of antagonists of urinary tract infections is ruled by the structural mimicry of natural epitopes and extends into blocking of bacterial invasion, intracellular growth and capacity to fluxing and of recurrence of the infection.

Association between nasopharyngeal load of Streptococcus pneumoniae, viral co-infection and radiologically confirmed pneumonia in Vietnamese children.

Hospitalized Vietnamese children with acute respiratory infection (ARI) were investigated for 13 viral pathogens using multiplex-polymerase chain reaction. We enrolled 958 children of whom 659(69%) had documented viral infection: rhinovirus (28%), respiratory syncytial virus (23%), influenza virus (15%), adenovirus (5%), human metapneumo virus (4.5%), parainfluenza virus (5%) and bocavirus (2%). These Vietnamese children had a range of respiratory viruses which underscores the need for enhanced ARI surveillance in tropical developing countries. Positive templates were used in each assay for quality control. RESULTSDuring the 14-months study period, a total of 1,014 pediatric patients from the catchment area were admitted to KHGH, of which 958 (95%) were enrolled in the study.Males comprised 58% of patients and 94% of the patients were less than 5 years old (median age: 1.4 years). The results showed that one or more respiratory viruses were found in 69% of patients: 11% had dual and 1.4% had triple infection. Eighty six percent of the viral ARI patients were less than 3 years old (detail information of age breakdown is shown in supplementary table 2, online only).Major viruses detected were rhinovirus (28%), RSV (23%) and influenza A (15%). This was followed by adenovirus (5%), hMPV (5%), PIV3 (4%) and bocavirus (2%). Other viruses (PIV1, PIV2 and influenza B) were detected in a small proportion (1.5%) of ARI patients. Across age, sex, and case categories, there were no significant differences between proportion of virus positive and negative patients.The pattern of virus detection did not differ between URTI and LRTI patients. A total of 268 radiologically-confirmed pneumonia (RCP) patients and 195 bronchiolitis 7 patients were identified. PIV3 detection was significantly associated with hospitalized LRTI (p=0.016) and bronchiolitis (p=<0.001). Similar to previous reports, we found that RSV infection was significantly associated with bronchiolitis (p=0.002) (6). We also found that a significantly higher proportion of patients (n=119)

Background: Guinea pig serum and liver contain an enzyme with L-asparaginase activity. Results: H0W0T5_CAVPO (gpASNase1) displays a low micromolar K m with Asn. Structures of apo and ASP complex are presented. Conclusion: gpASNase1is the likely identity of a guinea pig L-asparaginase endowed with anticancer properties. Significance: The high sequence identity to the human enzymes and its lack of L-glutaminase activity make gpASNase1 a potential replacement for the bacterial enzymes.

Four children in three unrelated families (one consanguineous) presented with lethargy, hyperlactatemia, and hyperammonemia of unexplained origin during the neonatal period and early childhood. We identified and validated three different CA5A alterations, including a homozygous missense mutation (c.697T>C) in two siblings, a homozygous splice site mutation (c.555G>A) leading to skipping of exon 4, and a homozygous 4 kb deletion of exon 6. The deleterious nature of the homozygous mutation c.697T>C (p.Ser233Pro) was demonstrated by reduced enzymatic activity and increased temperature sensitivity. Carbonic anhydrase VA (CA-VA) was absent in liver in the child with the homozygous exon 6 deletion. The metabolite profiles in the affected individuals fit CA-VA deficiency, showing evidence of impaired provision of bicarbonate to the four enzymes that participate in key pathways in intermediary metabolism: carbamoylphosphate synthetase 1 (urea cycle), pyruvate carboxylase (anaplerosis, gluconeogenesis), propionyl-CoA carboxylase, and 3-methylcrotonyl-CoA carboxylase (branched chain amino acids catabolism). In the three children who were administered carglumic acid, hyperammonemia resolved. CA-VA deficiency should therefore be added to urea cycle defects, organic acidurias, and pyruvate carboxylase deficiency as a treatable condition in the differential diagnosis of hyperammonemia in the neonate and young child.

Comprehensive population-based data on the role of respiratory viruses in the development of lower respiratory tract infections (LRTIs) remain unclear. We investigated the incidence and effect of single and multiple infections with respiratory viruses on the risk of LRTIs in Vietnam.Population-based prospective surveillance and a case-control study of hospitalised paediatric patients with acute respiratory infection (ARI) were conducted from April 2007 through to March 2010. Healthy controls were randomly recruited from the same community. Nasopharyngeal samples were collected and tested for 13 respiratory viruses using multiplex PCRs.1992 hospitalised ARI episodes, including 397 (19.9%) with LRTIs, were enrolled. Incidence of hospitalised LRTIs among children aged ,24 months was 2171.9 per 100 000 (95% CI 1947.9-2419.7). The majority of ARI cases (60.9%) were positive for at least one virus. Human rhinovirus (24.2%), respiratory syncytial virus (20.1%) and influenza A virus (12.0%) were the most common and 9.5% had multiple-viral infections. Respiratory syncytial virus and human metapneumovirus infections independently increased the risk of LRTIs. Respiratory syncytial virus further increased the risk, when co-infected with human rhinovirus, human metapneumovirus and parainfluenza virus-3 but not with influenza A virus. The casecontrol analysis revealed that respiratory syncytial virus and influenza A virus increased the risk of ARI hospitalisation but not human rhinovirus.Respiratory syncytial virus is the leading pathogen associated with risk of ARI hospitalisation and LRTIs in Vietnam. @ERSpublications RSV is the leading pathogen associated with risk of ARI hospitalisation and LRTIs in Vietnam

Acute lymphoblastic leukemia (ALL) is the most common type of pediatric cancer, although about 4 of every 10 cases occur in adults. The enzyme drug l-asparaginase serves as a cornerstone of ALL therapy and exploits the asparagine dependency of ALL cells. In addition to hydrolyzing the amino acid l-asparagine, all FDA-approved l-asparaginases also have significant l-glutaminase coactivity. Since several reports suggest that l-glutamine depletion correlates with many of the side effects of these drugs, enzyme variants with reduced l-glutaminase coactivity might be clinically beneficial if their antileukemic activity would be preserved. Here we show that novel low l-glutaminase variants developed on the backbone of the FDA-approved l-asparaginase were highly efficacious against both T- and B-cell ALL, while displaying reduced acute toxicity features. These results support the development of a new generation of safer l-asparaginases without l-glutaminase activity for the treatment of human ALL. A new l-asparaginase-based therapy is less toxic compared with FDA-approved high l-glutaminase enzymes .

Since the initial discovery of RSV-A ON1 in Canada in 2010, ON1 has been reported worldwide, yet information regarding its clinical impact and severity has been controversial. To investigate the clinical relevance of RSV-A ON1,acute respiratory infection (ARI) cases enrolled to our population-based prospective pediatric ARI surveillance at Khanh Hoa General Hospital, Central Vietnam from January 2010 through December 2012 were studied. Clinical-epidemiological information and nasopharyngeal samples were collected. Multiplex PCR assays were performed for screening 13 respiratory viruses. RSV-positive samples were further tested for subgroups (A/B) and genotypes information by sequencing the G-glycoprotein 2nd hypervariable region. Statistical analysis was performed to evaluate the clinical-epidemiological characteristics of RSV-A ON1. A total of 1854 ARI cases were enrolled and 426 (23.0%) of them were RSV-positive. During the study period, RSV-A and B had been co-circulating. NA1 was the predominant RSV-A genotype until the appearance of ON1 in 2012. RSV-related ARI hospitalization incidence significantly increased after the emergence of ON1. Moreover, multivariate analysis revealed that risk of lower respiratory tract infection was 2.26 (95% CI: 1.37–3.72) times, and radiologically-confirmed pneumonia was 1.98 (95% CI: 1.01–3.87) times greater in ON1 compared to NA1 cases. Our result suggested that ON1 ARI cases were clinically more severe than NA1.