Molecular and antigenic characterization of bovine Coronavirus circulating in Argentinean cattle during 1994-2010

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Detection rate of BCoV was statistically higher in dairy than in beef calves.

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Argentinean strains are distant from the Mebus strain included in local vaccines.

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In vitro cross-protection between Arg95 field strain and Mebus reference strain.

Bovine coronavirus (BCoV) is an important viral pathogen associated with neonatal calf diarrhea. Our aim was to investigate the incidence of BCoV in diarrhea outbreaks in beef and dairy herds from Argentina during 1994–2010. A total of 5.365 fecal samples from diarrheic calves were screened for BCoV diagnosis by ELISA. The virus was detected in 1.71% (92/5365) of the samples corresponding to 5.95% (63/1058) of the diarrhea cases in 239 beef and 324 dairy farms. The detection rate of BCoV was significantly higher in dairy than in beef herds: 12.13% (29/239) vs. 4.32% (14/324) respectively. Phylogenetic analysis of the hypervariable S1 region of seven representative samples (from different husbandry systems, farm locations and years of sampling) indicated that BCoV strains circulating in Argentinean beef and dairy herds formed a cluster distinct from other geographical regions. Interestingly, Argentinean strains are distantly related (at both the nucleotide and amino acid levels) with the Mebus historic reference BCoV strain included in the vaccines currently available in Argentina. However, Mebus-induced antibodies were capable of neutralizing the BCoV Arg95, a field strain adapted to grow in vitro, and vice versa, indicating that both strains belong to the same CoV serotype reported in cattle. This work represents the first large survey describing BCoV circulation in Argentinean cattle.

Migration of germline progenitor cells is directed by sphingosine-1-phosphate signalling in a basal chordate

The colonial ascidian Botryllus schlosseri continuously regenerates entire bodies in an asexual budding process. The germ line of the newly developing bodies is derived from migrating germ cell precursors, but the signals governing this homing process are unknown. Here we show that germ cell precursors can be prospectively isolated based on expression of aldehyde dehydrogenase and integrin alpha-6, and that these cells express germ cell markers such as vasa, pumilio and piwi, as well as sphingosine-1-phosphate receptor. In vitro, sphingosine-1-phosphate (S1P) stimulates migration of germ cells, which depends on integrin alpha-6 activity. In vivo, S1P signalling is essential for homing of germ cells to newly developing bodies. S1P is generated by sphingosine kinase in the developing germ cell niche and degraded by lipid phosphate phosphatase in somatic tissues. These results demonstrate a previously unknown role of the S1P signalling pathway in germ cell migration in the ascidian Botryllus schlosseri.

The regulation of germ cell migration in the colonial ascidian Botryllus schlosseri is poorly understood. In this chordate, Kassmer et al. identify sphingosine-1-phosphate as regulating germ cell migration in vitro and homing of cells to newly developing bodies in live organisms.

Molecular evolution and in vitro characterization of Botryllus histocompatibility factor

Botryllus schlosseri is a colonial ascidian with a natural ability to anastomose with another colony to form a vascular and hematopoietic chimera. In order to fuse, two individuals must share at least one allele at the highly polymorphic fuhc locus. Otherwise, a blood-based inflammatory response will occur resulting in a melanin scar at the sites of interaction. The single-locus genetic control of allorecognition makes B. schlosseri an attractive model to study the underlying molecular mechanisms. Over the past decade, several candidate genes involved in allorecognition have been identified, but how they ultimately contribute to allorecognition outcome remains poorly understood. Here, we report our initial molecular characterization of a recently identified candidate allodeterminant called Botryllus histocompatibility factor (bhf). bhf, both on a DNA and protein level, is the least polymorphic protein in the fuhc locus studied so far and, unlike other known allorecognition determinants, does not appear to be under any form of balancing or directional selection. Additionally, we identified a second isoform through mRNA-Seq and an EST assembly library which is missing exon 3, resulting in a C-terminally truncated form. We report via whole-mount fluorescent in situ hybridization that a subset of cells co-express bhf and cfuhc(sec). Finally, we observed BHF's localization in HEK293T at the cytoplasmic side of the plasma membrane in addition to the nucleus via a nuclear localization signal. Given the localization data thus far, we hypothesize that BHF may function as a scaffolding protein in a complex with other Botryllus proteins, rather than functioning as an allorecognition determinant.

Magnetic resonance diffusion metrics indexing high focal cellularity and sharp transition at the tumour boundary predict poor outcome in glioblastoma multiforme

AIM

To investigate the prognostic power of intra-tumoural and gradient magnetic resonance imaging (MRI) diffusion metrics in patients with glioblastoma multiforme (GBM).

MATERIALS AND METHODS

Forty-six consecutive patients with histologically confirmed GBM who had undergone preoperative diffusion tensor imaging at 3 T were included. Mean diffusivity (MD) and MD gradient maps were computed. Regions of interest were analysed to determine the minimum MD within the enhancing tumour (minMD). MD gradients were calculated along the enhancing tumour boundary and subjected to histogram analysis. Overall survival (OS) and time to progression (TTP) were derived and survival analysis was undertaken.

RESULTS

There were 31 deaths and 37 patients progressed during the study period. Multivariate survival analysis, controlling for treatment and gender, showed that minMD values<6.1×10(-4) mm(2)/s predicted shorter OS (hazard ratio [HR]=2.82, 1.25-6.34; p=0.012) and TTP (HR=5.43, 1.96-15.05; p=0.001). Higher MD gradient values of the tumour boundary predicted shorter survival: MD gradient values >4.7×10(-5) mm(2)/s (10(th) centile) had a significantly shorter OS with a HR of 0.43 (0.19-0.96; p=0.04). Similarly, a value above 1.4×10(-4) mm(2)/s (75(th) centile) was a significant predictor for shorter OS (HR=0.39, 0.17-0.89; p=0.03).

CONCLUSIONS

Lower minMD and higher MD gradient values for the 10(th) and 75(th) percentile of the tumour boundary demonstrated prognostic value in preoperative GBM. This suggests that MRI diffusion metrics indicative of higher focal cellularity and steeper transition from high cellular tumour edge to low cellular oedema define more aggressive glioblastoma subtypes with a poorer prognosis.

Advances in the metabolic profiling of acidic compounds in children's urines achieved by comprehensive two-dimensional gas chromatography

The main objective of this work was to evaluate a comprehensive two-dimensional gas chromatographic (GCxGC) coupled to quadrupole mass spectrometry (qMS) method in the field of biomarker candidates' discovery. To this purpose we developed a GCxGC-qMS method suitable for the separation of organic acids and other classes of compounds with silylable polar hydrogen such as sugars, amino-acids, and vitamins. As compared to those obtained by a widely used 1D-GC method, the urinary chromatographic profiles performed by the proposed 2D-GC method exhibit higher resolution and sensitivity, leading to the detection of up to 92 additional compounds in some urine samples including some well-known biomarkers. In order to validate the proposed method we focused on three metabolites of interest with various functional groups and polarities including CH3-malonic acid (MMA: biomarker of methylmalonic acidemia), 3-hydroxy-3-methyl-glutaric acid (3-OHMGA: biomarker of 3-hydroxy-3-methylglutaric acidemia), and phenylpiruvic acid (PhPA: marker of phenylketonuria). While these three metabolites can be considered as representative of organic acids classically determined by 1D-GC, they cannot be representative of new detected metabolites. Thus, we also focused on quinolic acid (QUIN), taken as an example of biomarker not detected at basal levels with the classical 1D GC-qMS method. In order to obtain sufficient recoveries for all tested compounds, we developed a sample preparation protocol including a step of urea removal followed by two extraction steps using two solvents of different polarity and selectivity. Recoveries with the proposed method reached more than 80% for all targeted compounds and the linearity was satisfactory up to 50μmol/L. The CVs of the within-run and within-laboratory precisions were less than 8% for all tested compounds. The limits of quantification (LOQs) were 0.6μmol/L for MMA, 0.4μmol/L for 3-OHMGA, 0.7μmol/L for PhPA, and 1μmol/L for QUIN. The LOQs of these metabolites obtained by a classical GC-MS method under the same chromatographic conditions were 5μmol/L for MMA, 4μmol/L for 3-OHMGA, 6μmol/L for PhPA while QUIN was below the limit of detection. As compared to 1D-GC, these results highlight the enhanced detectability of urine metabolites by the 2D-GC technique. Our results also show that for each new detected compound it is necessary to develop and validate an appropriate sample preparation procedure.

Analysis of the basal chordate Botryllus schlosseri reveals a set of genes associated with fertility

Background

Gonad differentiation is an essential function for all sexually reproducing species, and many aspects of these developmental processes are highly conserved among the metazoa. The colonial ascidian, Botryllus schlosseri is a chordate model organism which offers two unique traits that can be utilized to characterize the genes underlying germline development: a colonial life history and variable fertility. These properties allow individual genotypes to be isolated at different stages of fertility and gene expression can be characterized comprehensively.

Results

Here we characterized the transcriptome of both fertile and infertile colonies throughout blastogenesis (asexual development) using differential expression analysis. We identified genes (as few as 7 and as many as 647) regulating fertility in Botryllus at each stage of blastogenesis. Several of these genes appear to drive gonad maturation, as they are expressed by follicle cells surrounding both testis and oocyte precursors. Spatial and temporal expression of differentially expressed genes was analyzed by in situ hybridization, confirming expression in developing gonads.

Conclusion

We have identified several genes expressed in developing and mature gonads in B. schlosseri. Analysis of genes upregulated in fertile animals suggests a high level of conservation of the mechanisms regulating fertility between basal chordates and vertebrates.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-1183) contains supplementary material, which is available to authorized users.

Aging in the colonial chordate, Botryllus schlosseri

What mechanisms underlie aging? One theory, the wear-and-tear model, attributes aging to progressive deterioration in the molecular and cellular machinery which eventually lead to death through the disruption of physiological homeostasis. The second suggests that life span is genetically programmed, and aging may be derived from intrinsic processes which enforce a non-random, terminal time interval for the survivability of the organism. We are studying an organism that demonstrates both properties: the colonial ascidian, Botryllus schlosseri. Botryllus is a member of the Tunicata, the sister group to the vertebrates, and has a number of life history traits which make it an excellent model for studies on aging. First, Botryllus has a colonial life history, and grows by a process of asexual reproduction during which entire bodies, including all somatic and germline lineages, regenerate every week, resulting in a colony of genetically identical individuals. Second, previous studies of lifespan in genetically distinct Botryllus lineages suggest that a direct, heritable basis underlying mortality exists that is unlinked to reproductive effort and other life history traits. Here we will review recent efforts to take advantage of the unique life history traits of B. schlosseri and develop it into a robust model for aging research.

Gemcitabine plus capecitabine (Gem-Cape) biweekly in chemorefractory metastatic colorectal cancer

Purpose

A proportion of patients with metastatic colorectal cancer (mCRC) are still able to continue with active therapy after their progression to fluoropyrimidines, oxaliplatin, and irinotecan regimens. Studies suggest that gemcitabine and fluoropyrimidines are synergic antimetabolites. The purpose was to evaluate gemcitabine–capecitabine (Gem–Cape) in heavily pretreated mCRC and to thus assess possible predictive factors for progression-free survival (PFS) and overall survival (OS).

Patients and methods

This analysis was performed on 119 evaluable patients pretreated with fluoropyrimidines, oxaliplatin, irinotecan, and biological agents between June 2001 and July 2011. Patients received gemcitabine 1,000 mg/m² day 1 and capecitabine 1,000 mg/m²bid for 7 days every 2 weeks.

Results

The general characteristics were ECOG 0–1, 89 %; male, 68 %, and median age 63 years. In total, 61 % had received two chemotherapy lines, while 39 % had received three or more. Objective response rates and stable disease rates at 3 months were 6.72 and 37.81 %, equalling a clinical benefit of 44.53 %. The median PFS and OS were 2.87 months [95 % confidence interval (CI) 2.53–3.17 months] and 6.53 months (95 % CI 5.33–8.77), respectively. The most frequent toxicities were grades 1–2, anemia (22 %), thrombocytopenia (10 %), and hand–foot syndrome (9 %); grade ≥3, diarrhea (2 %), with no treatment-related discontinuations. No treatment-related deaths were reported. Statistical significance was obtained by subgroups, assessing clinical benefits and objective responses for PFS and OS. Moreover, patients under 65 tended to have a better PFS.

Conclusion

These data suggest that Gem–Cape is a tolerable and feasible regimen, associated with clinical benefit in non-selected, heavily pretreated, mCRC patients.

Whole-mount fluorescent in situ hybridization staining of the colonial tunicate Botryllus schlosseri

Botryllus schlosseri is a colonial ascidian with characteristics that make it an attractive model for studying immunology, stem cell biology, evolutionary biology, and regeneration. Transcriptome sequencing and the recent completion of a draft genome sequence for B. schlosseri have revealed a large number of genes, both with and without vertebrate homologs, but analyzing the spatial and temporal expression of these genes in situ has remained a challenge. Here, we report a robust protocol for in situ hybridization that enables the simultaneous detection of multiple transcripts in whole adult B. schlosseri using Tyramide Signal Amplification in conjunction with digoxigenin- and dinitrophenol-labeled RNA probes. Using this protocol, we have identified a number of genes that can serve as markers for developing and mature structures in B. schlosseri, permitting analysis of phenotypes induced in loss-of-function experiments.

Meta-analysis of randomized trials comparing combined compression and anticoagulation with either modality alone for prevention of venous thromboembolism after surgery

Background

Although venous thromboembolism (VTE) is an important cause of postoperative morbidity and mortality, there is still no consensus on the optimal strategy for VTE prevention after major surgery. The objective of this review was to determine the benefits and risks of thromboprophylaxis with both compression and anticoagulation, compared with either modality alone.

Methods

A systematic review of MEDLINE, CENTRAL and Embase databases was performed to identify eligible randomized trials. The literature search and data extraction were carried out independently by two reviewers. Outcomes of interest were deep vein thrombosis (DVT), pulmonary embolism, bleeding, limb injury and mortality.

Results

Twenty-five studies were eligible for inclusion. Adding compression to anticoagulation decreased the risk of DVT by 49 per cent (risk ratio (RR) 0·51, 95 per cent confidence interval 0·36 to 0·73). The corresponding funnel plot suggested publication bias and, overall, the evidence for this comparison was judged to be of low quality. Adding anticoagulation to compression decreased the risk of DVT by 44 per cent (RR 0·56, 0·45 to 0·69) while increasing the risk of bleeding (RR 1·74, 1·29 to 2·34). There was no suggestion of publication bias and the evidence for this comparison was judged to be of moderate quality.

Conclusion

Combined compression and anticoagulation is more effective at preventing postoperative DVT than either modality alone. However, adding anticoagulation to compression increases the risk of bleeding, and the evidence that adding compression to anticoagulation reduces VTE risk is of low quality.