Characterization of terminal NeuNAcalpha2-3Galbeta1-4GlcNAc sequence in lipooligosaccharides of Neisseria meningitidis

Group B and C Neisseria meningitidis are the major cause of meningococcal disease in the United States and in Europe. N . meningitidis lipooligosaccharide (LOS), a major surface antigen, can be divided into 12 immunotypes of which L1 through L8 were found among Group B and C organisms. Groups B and C but not Group A may sialylate their LOSs with N-acetylneuraminic acid (NeuNAc) at the nonreducing end because they synthesize CMP-NeuNAc. Using sialic acid-galactose binding lectins as probes in an ELISA format, six of the eight LOS immunotypes (L2, L3, L4, L5, L7, and L8) in Groups B and C bound specifically to Maackia amurensis leukoagglutinin (MAL), which recognizes NeuNAcalpha2- 3Galbeta1-4GlcNAc/Glc sequence, but not to Sambucus nigra agglutinin, which binds NeuNAcalpha2-6Gal sequence. The combination of SDS-PAGE and MAL-blot analyses revealed that these six LOSs contained only the NeuNAcalpha2-3Galbeta1-4GlcNAc trisaccharide sequence in their 4.1 kDa LOS components, which have a common terminal lacto-N-neotetraose (LNnT, Galbeta1-4GlcNAcbeta1-3Galbeta1-4Glc) structure when nonsialylated as shown by previous studies. The LOS-lectin binding was abolished when the LOSs were treated with Newcastle disease viral neuraminidase which cleaves alpha2-->3 linked sialic acid. Methylation analysis of a representative LOS (L2) confirmed that NeuNAc is 2-->3 linked to Gal. Thus, these LOSs structurally mimic certain glycolipids, i.e., paragloboside (LNnT-ceramide) and sialylparagloboside and some glycoproteins in having LNnT and N-acetyllactosamine sequences, respectively, with or without alpha2-->3 linked NeuNAc. The molecular mimicry of the LOSs may play a role in the pathogenesis of N.meningitidis by assisting the organism to evade host immune defenses in man.      

A novel EspA-associated surface organelle of enteropathogenic Escherichia coli involved in protein translocation into epithelial cells.

Enteropathogenic Escherichia coli (EPEC), like many bacterial pathogens, employ a type III secretion system to deliver effector proteins across the bacterial cell. In EPEC, four proteins are known to be exported by a type III secretion system_EspA, EspB and EspD required for subversion of host cell signal transduction pathways and a translocated intimin receptor (Tir) protein (formerly Hp90) which is tyrosine-phosphorylated following transfer to the host cell to become a receptor for intimin-mediated intimate attachment and 'attaching and effacing' (A/E) lesion formation. The structural basis for protein translocation has yet to be fully elucidated for any type III secretion system. Here, we describe a novel EspA-containing filamentous organelle that is present on the bacterial surface during the early stage of A/E lesion formation, forms a physical bridge between the bacterium and the infected eukaryotic cell surface and is required for the translocation of EspB into infected epithelial cells.     

Oswaldofiaria chabaudi n. sp. (Nematoda: Onchocercidae) from a South American tropidurid lizard (Squamata: Iguania) with an update on Oswaldofilariinae

A new species of Oswaldofilaria is described from Tropidurus torquatus (Tropiduridae: Iguania); its prevalence at the rocky study area at Juiz de Fora, Minas Gerais, Brazil, was approximately 30% and its mean intensity 3.13 +/- 2.51. Oswaldofilaria chaboudi n. sp. is distinct from the thirteen Oswaldofilaria species known in Australia, Africa and South-America in having the following characteristics: oesophagus medium-sized, left spicule 1 mm long and high spicular ratio (about 5), tail extremity ornated in both sexes with a bifurcated projection, and tooth-like structures near phasmids in the female. A long left spicule and high spicular ratio are convergent derived characters also found in a parasite of Australian crocodilians, O. kanbaya, and in several species of the closely related genus Befilaria, such as the Central American B. puertoricensis from polychrotids. Oswaldofilaria in South America is represented by eight species. Within these, a primitive group that is parasitic in Iguanidae, Polychrotidae (Iguania) and Crocodylidae and that possesses a long oesophagus is recognised, together with two distinct derived lines: three species with numerous, aligned precloacal papillae, parasitic in Teiidae (Laterato) and Scincidae (Scincomorpha), and O. chabaudi n. sp., in which this character is absent. Tropidurids (Tropiduris and Plica) had previously been reported in the host range of two oswaldofilarine genera, Oswaldofilaria and Piratuba, and their parasites assigned to known species described from other groups of lizards.     

Roles of the main olfactory and vomeronasal systems in the detection of androstenone in inbred strains of mice

We investigated the role of the main olfactory and accessory olfactory systems (MOS and AOS respectively) in the detection of androstenone. We used the following experimental approaches: behavioral, surgical removal of the vomeronasal organ (VNX) followed by histochemical verification and Fos immunohistochemistry. Using a Y-maze paradigm we estimated sensitivity of NZB/B1NJ and CBA/J mice to androstenone. CBA mice were 2,000-fold more sensitive to androstenone than NZB mice. VNX caused a 4- to 16-fold decre...     

Assessing and reporting heterogeneity in treatment effects in clinical trials: a proposal

Background

This paper presents the study protocol for a pragmatic randomised controlled trial to evaluate the impact of a school based program developed to prevent teenage pregnancy. The program includes students taking care of an Infant Simulator; despite growing popularity and an increasing global presence of such programs, there is no published evidence of their long-term impact. The aim of this trial is to evaluate the Virtual Infant Parenting (VIP) program by investigating pre-conceptual health and risk behaviours, teen pregnancy and the resultant birth outcomes, early child health and maternal health.

Methods and Design

Fifty-seven schools (86% of 66 eligible secondary schools) in Perth, Australia were recruited to the clustered (by school) randomised trial, with even randomisation to the intervention and control arms. Between 2003 and 2006, the VIP program was administered to 1,267 participants in the intervention schools, while 1,567 participants in the non-intervention schools received standard curriculum. Participants were all female and aged between 13-15 years upon recruitment. Pre and post-intervention questionnaires measured short-term impact and participants are now being followed through their teenage years via data linkage to hospital medical records, abortion clinics and education records. Participants who have a live birth are interviewed by face-to-face interview. Kaplan-Meier survival analysis and proportional hazards regression will test for differences in pregnancy, birth and abortion rates during the teenage years between the study arms.

Discussion

This protocol paper provides a detailed overview of the trial design as well as initial results in the form of participant flow. The authors describe the intervention and its delivery within the natural school setting and discuss the practical issues in the conduct of the trial, including recruitment. The trial is pragmatic and will directly inform those who provide Infant Simulator based programs in school settings.

Trial registration

ISRCTN24952438     

Multilocus sequence types of Finnish bovine <Emphasis Type="Italic">Campylobacter jejuni</Emphasis> isolates and their attribution to human infections

Background  

Campylobacter jejuni is the most common bacterial cause of human gastroenteritis worldwide. Due to the sporadic nature of infection, sources often remain unknown. Multilocus sequence typing (MLST) has been successfully applied to population genetics of Campylobacter jejuni and mathematical modelling can be applied to the sequence data. Here, we analysed the population structure of a total of 250 Finnish C. jejuni isolates from bovines, poultry meat and humans collected in 2003 using a combination of Bayesian clustering (BAPS software) and phylogenetic analysis.     

Three species of <Emphasis Type="Italic">Skrjabinelazia</Emphasis> Sypliaxov, 1930 (Nematoda: Seuratidae) parasitic in Gekkonidae and Lacertidae from South Africa,Europe and Australia

Skrjabinelazia Sypliaxov, 1930 comprises 10 species distinguished by several characters typical of the genus including, among the most important, the presence/absence of spicules, cuticle ornamentation and vesicles, head-shape, the presence/absence of a leaflet crown in the buccal cavity, female tail-shape and male cone-shape. The three samples studied are new species: S. boomkeri n. sp., a parasite of Pachydactylus turneri, Gekkonidae, from South Africa (Klaserie Reserve); S. vozae n. sp., a parasite of Lacerta vivipara, Lacertidae, from France (Cévennes), which is close to two lacertid parasites, S. taurica Sypliaxov, 1930 and L. hoffmanni Li, 1934, respectively from the Crimea and North China (Peking); and S. mawsangelae n. sp. (male unknown), a parasite of Christinus marmoratus, Gekkonidae, from Australia (Pearson Island), which is, surprisingly, distinct from Skrjabinelazia sp. of Angel & Mawson (1968) from the same host in another region (North of Adelaide) of South Australia. Two main groups are distinguished in Skrjabinelazia: the species with spicules which are parasitic in the Lacertidae, and the species with a gubernaculum only which are parasitic in the Gekkonidae. The unique species described from the Iguanidae, S. intermedia (Freitas, 1940) from Brazil (Para), also without spicules, seems to be derived from gekkonid parasites, as it also has an evolved oesophagus with a glandular region, unlike the simple oesophagus seen in the larval stages of Skrjabinelazia.     

Fracture prevention in COPD patients; a clinical 5-step approach

Although osteoporosis and its related fractures are common in patients with COPD, patients at high risk of fracture are poorly identified, and consequently, undertreated. Since there are no fracture prevention guidelines available that focus on COPD patients, we developed a clinical approach to improve the identification and treatment of COPD patients at high risk of fracture. We organised a round-table discussion with 8 clinical experts in the field of COPD and fracture prevention in the Netherlands in December 2013. The clinical experts presented a review of the literature on COPD, osteoporosis and fracture prevention. Based on the Dutch fracture prevention guideline, they developed a 5-step clinical approach for fracture prevention in COPD. Thereby, they took into account both classical risk factors for fracture (low body mass index, older age, personal and family history of fracture, immobility, smoking, alcohol intake, use of glucocorticoids and increased fall risk) and COPD-specific risk factors for fracture (severe airflow obstruction, pulmonary exacerbations and oxygen therapy). Severe COPD (defined as postbronchodilator FEV₁ < 50% predicted) was added as COPD-specific risk factor to the list of classical risk factors for fracture. The 5-step clinical approach starts with case finding using clinical risk factors, followed by risk evaluation (dual energy X-ray absorptiometry and imaging of the spine), differential diagnosis, treatment and follow-up. This systematic clinical approach, which is evidence-based and easy-to-use in daily practice by pulmonologists, should contribute to optimise fracture prevention in COPD patients at high risk of fracture.