Growth of bifidobacteria and clostridia on human and cow milk saccharides

For healthy infants, which were born normally and fully breastfed, the dominant component of the intestinal microflora are bifidobacteria. However, infants born by caesarean section possess clostridia as a dominant intestinal bacterial group. The aim of the present study was to determine whether bifidobacteria and clostridia are able to grow on human milk oligosaccharides (HMOs) and other carbon sources - lactose, cow milk (CM) and human milk (HM). Both bifidobacteria and clostridia grew on lactose and in CM. Bifidobacteria grew in HM and on HMOs. In contrast, 3 out of 5 strains of clostridia were not able to grow in HM. No clostridial strain was able to utilise HMOs. While both bifidobacterial strains were resistant to lysozyme, 4 out of 5 strains of clostridia were lysozyme-susceptible. It seems that HMOs together with lysozyme may act as prebiotic-bifidogenic compounds inhibiting intestinal clostridia.     

Isolation and characterization of 20 polymorphic microsatellite loci in the migratory freshwater fish Leporinus obtusidens (Characiformes: Anostomidae) using 454 shotgun pyrosequencing

Twenty polymorphic microsatellite markers were developed for the Neotropical fish Leporinus obtusidens using a next generation sequencing approach and tested in two other characifomes species, Schizodon platae and Prochilodus lineatus. Microsatellite loci alleles in L. obtusidens ranged between 2 and 20 alleles per locus (mean = 5·7), with expected heterozygosity values ranging from 0·097 to 0·956 (mean = 0·578) and observed heterozygosity values ranging from 0·000 to 0·800 (mean = 0·400) in a sample of 20 specimens from the lower Paraná River (Argentina). Most of these markers will be a valuable tool for captive breeding and stocking programmes, as well as for analyses of population connectivity and genetic structure in this broadly distributed Neotropical migratory fish.     

Associations between Parental Feeding Styles and Childhood Eating Habits: A Survey of Hong Kong Pre-School Children

Childhood obesity is a global public health issue, including in the Chinese setting, and its prevalence has increased dramatically throughout the last decade. Since the origins of childhood obesity may lie in the pre-school period, factors relating to very young children’s food consumption should be investigated. Parental influence, including feeding style, is the major determinant of childhood dietary behaviour through altering food provision and social environment. However, the applicability of previous research on parental feeding styles was limited by small sample size. To evaluate the influence of parental feeding styles on children''s dietary patterns, a cross-sectional study was conducted among 4553 pre-schoolers in Hong Kong. Information was obtained about dietary intake and how regularly they had breakfast, using previous health surveillance surveys taken among primary school students. Parental feeding styles were assessed by a validated Parental Feeding Style Questionnaire and categorized into ‘instrumental feeding’, ‘emotional feeding’, ‘prompting and encouragement to eat’ and ‘control over eating’. Multivariable analysis was performed, adjusted for demographic information. Instrumental and/or emotional feeding was found to relate to inadequate consumption of fruit, vegetables and breakfast, and positively correlated with intake of high-energy-density food. Encouragement on eating was associated with more frequent consumption of fruits, vegetables, dairy products and breakfast. Control over eating correlated with more frequent consumption of fruits, vegetables and breakfast, and less consumption of dairy products and high-energy-density food. The present study has provided evidence on the associations between parental feeding styles and dietary patterns of Hong Kong pre-school children from a reasonably large population. Parents should avoid instrumental and emotional feeding, and implement control and encouragement to promote healthy food intake. Longitudinal studies and interventions on parental feeding style are required to confirm the research findings.     

Defective regression models for cure rate modeling with interval‐censored data

Regression models in survival analysis are most commonly applied for right‐censored survival data. In some situations, the time to the event is not exactly observed, although it is known that the event occurred between two observed times. In practice, the moment of observation is frequently taken as the event occurrence time, and the interval‐censored mechanism is ignored. We present a cure rate defective model for interval‐censored event‐time data. The defective distribution is characterized by a density function whose integration assumes a value less than one when the parameter domain differs from the usual domain. We use the Gompertz and inverse Gaussian defective distributions to model data containing cured elements and estimate parameters using the maximum likelihood estimation procedure. We evaluate the performance of the proposed models using Monte Carlo simulation studies. Practical relevance of the models is illustrated by applying datasets on ovarian cancer recurrence and oral lesions in children after liver transplantation, both of which were derived from studies performed at A.C. Camargo Cancer Center in São Paulo, Brazil.     

Diet of labrisomid blenny Auchenionchus variolosus (Valenciennes, 1836) (Labrisomidae) during its larval development off central Chile (2012–2013)

The diet, feeding success (prey number and total volume per gut, and maximum prey width) and trophic niche width of the labrisomid blenny Auchenionchus variolosus (Valenciennes, 1836) was studied during its larval development (3.93–17.26 mm standard length). Individuals were collected in October 2012 and October 2013 in nearshore waters (<500 m offshore) from Bahía Valparaíso, central Chile with Bongo nets. When compared to the same length range, larval A. variolosus collected during 2013 showed larger upper jaw‐at‐sizes than those from 2012. This coincided with a reduction in relative importance (%IRI) of the main prey item, copepod nauplii, from ~90 to ~73%. Feeding incidence (FI) was high throughout larval development, varying from 97.3 to 100%, being similar throughout the larval development. Prey items per gut (PIPG) ranged from 0 to 35 prey, showing no differences among years. Total volume per gut (TVPG) was positively correlated with larval length, and at given larval size, TVPG ingested by larval A. variolosus was larger during 2013 (0.0607 mm³) than during 2012 (0.0301 mm³). Prey width range was 47.47–700.94 μm and was positively correlated with standard length (SL). Niche breadth was independent of larval size and did not change during larval development in 2012 or 2013. The study helps to understand the trophic interactions occurring in nearshore waters off rocky reef environments from mid‐latitudes of the Southeast Pacific coasts.     

Development of a S. cerevisiae whole cell biocatalyst for in vitro sialylation of oligosaccharides

Absence of sialylation on recombinant glycoproteins compromises their efficacy as therapeutic agents, as it results in rapid clearance from the human bloodstream. To circumvent this, several strategies are followed, including the implementation of a post-secretion glycosylation step. In this paper we describe the engineering of yeast cells expressing active surface exposed Trypanosoma cruzi trans-sialidase (TS) fused to the yeast Aga2 protein, and the use of this yeast in the sialylation of synthetic oligosaccharides. In an attempt to improve overall protein accessibility on the yeast surface, we abolished hyperglycosylation on the yeast cell wall proteins. This was achieved by disrupting the OCH1 gene of the TS surface expressing strain, which resulted in increased enzymatic activity. Using a fluorescence-based activity assay and DSA-FACE structural analysis, we obtained almost complete conversion to a fully sialylated acceptor, whereas in the wild type situation this conversion was only partial. Increasing protein accessibility on the yeast surface by modifying the glycosylation content thus proved to be a valuable approach in increasing the cell wall associated activity of an immobilised enzyme, hence resulting in a more effective biocatalyst system.     

Causal role of oxidative stress in liver preconditioning by thyroid hormone in rats

Hepatic ischemia-reperfusion (IR) injury, a major clinical drawback during surgery, is abolished by L-3,3',5-triiodothyronine (T(3)) administration. Considering that the triggering mechanisms are unknown, the aim of this study is to assess the role of oxidative stress in T(3) preconditioning using N-acetylcysteine (NAC) before T(3) administration. Male Sprague-Dawley rats given a single dose of 0.1 mg of T(3)/kg were subjected to 1 h ischemia followed by 20 h reperfusion, in groups of animals pretreated with 0.5 g of NAC/kg 0.5 h before T(3) or with the respective control vehicles. At the end of the reperfusion period, blood and liver samples were taken for analysis of serum aspartate aminotransferase (AST) and hepatic histology, glutathione (GSH) and protein carbonyl contents, and nuclear factor-kappaB (NF-kappaB) and activating protein 1 (AP-1) DNA binding. The IR protocol used led to a 4.5-fold increase in serum AST levels and drastic changes in liver histology, with significant GSH depletion and enhancement of protein carbonyl levels and of the protein carbonyl/GSH content ratio, whereas NF-kappaB and AP-1 DNA binding was decreased and enhanced, respectively. In a time window of 48 h, T(3) exerted protection against hepatic IR injury, with 88% reduction in the protein carbonyl/GSH ratio and normalization of NF-kappaB and AP-1 DNA binding, changes that were suppressed by NAC administration before T(3). Data presented suggest that a transient increase in the oxidative stress status of the liver is an important trigger for T(3) preconditioning, evidenced in a warm IR injury model through antioxidant intervention.     

Human Hemorrhagic Pulmonary Leptospirosis: Pathological Findings and Pathophysiological Correlations

Background

Leptospirosis is a re-emerging zoonosis with protean clinical manifestations. Recently, the importance of pulmonary hemorrhage as a lethal complication of this disease has been recognized. In the present study, five human necropsies of leptospirosis (Weil‘s syndrome) with extensive pulmonary manifestations were analysed, and the antibodies expressed in blood vessels and cells involved in ion and water transport were used, seeking to better understand the pathophysiology of the lung injury associated with this disease.

Principal Findings

Prominent vascular damage was present in the lung microcirculation, with decreased CD34 and preserved aquaporin 1 expression. At the periphery and even inside the extensive areas of edema and intraalveolar hemorrhage, enlarged, apparently hypertrophic type I pneumocytes (PI) were detected and interpreted as a non-specific attempt of clearence of the intraalveolar fluid, in which ionic transport, particularly of sodium, plays a predominant role, as suggested by the apparently increased ENaC and aquaporin 5 expression. Connexin 43 was present in most pneumocytes, and in the cytoplasm of the more preserved endothelial cells. The number of type II pneumocytes (PII) was slightly decreased when compared to normal lungs and those of patients with septicemia from other causes, a fact that may contribute to the progressively low PI count, resulting in deficient restoration after damage to the alveolar epithelial integrity and, consequently, a poor outcome of the pulmonary edema and hemorrhage.

Conclusions

Pathogenesis of lung injury in human leptospirosis was discussed, and the possibility of primary non-inflammatory vascular damage was considered, so far of undefinite etiopathogenesis, as the initial pathological manifestation of the disease.