Using fecal immmunochemical cartridges for gut microbiome analysis within a colorectal cancer screening program

The colorectal cancer (CRC) screening program B-PREDICT is an invited two-stage screening project using a fecal immunochemical test (FIT) for initial screening followed by a colonoscopy for those with a positive FIT. Since the gut microbiome likely plays a role in the etiology of CRC, microbiome-based biomarkers in combination with FIT could be a promising tool for optimizing CRC screening. Therefore, we evaluated the usability of FIT cartridges for microbiome analysis and compared it to Stool Collection and Preservation Tubes. Corresponding FIT cartridges as well as Stool Collection and Preservation Tubes were collected from participants of the B-PREDICT screening program to perform 16S rRNA gene sequencing. We calculated intraclass correlation coefficients (ICCs) based on center log ratio transformed abundances and used ALDEx2 to test for significantly differential abundant taxa between the two sample types. Additionally, FIT and Stool Collection and Preservation Tube triplicate samples were obtained from volunteers to estimate variance components of microbial abundances. FIT and Preservation Tube samples produce highly similar microbiome profiles which cluster according to subject. Significant differences between the two sample types can be found for abundances of some bacterial taxa (e.g. 33 genera) but are minor compared to the differences between the subjects. Analysis of triplicate samples revealed slightly worse repeatability of results for FIT than for Preservation Tube samples. Our findings indicate that FIT cartridges are appropriate for gut microbiome analysis nested within CRC screening programs.

Epithelial splicing regulatory protein 1 and 2 paralogues correlate with splice signatures and favorable outcome in human colorectal cancer

ESRPs are master splice regulators implicated in alternative mRNA splicing programs important for epithelial-mesenchymal transition (EMT) and tumor progression. ESRP1 was identified in some tumors as good or worse predictor of outcome, but in colorectal cancer (CRC) the prognostic value of ESRPs and relation with mesenchymal splice variants is not clear. Here, we studied 68 CRC cases, compared tissue expression of ESRPs with clinical data and with EMT gene splice patterns of conditional CRC cells with deficient ESRP1 expression.Around 72% of patients showed global decreased transcript expression of both ESRPs in tumor as compared to matched non-neoplastic colorectal epithelium. Reduction of ESRP1 in tumor cells was evaluated by immunohistochemistry, associated with microsatellite stability and switch to mesenchymal splice signatures of FGFRs, CD44, ENAH and CTNND1(p120-catenin). Expression of ESRPs was significantly associated with favorable overall survival (log-rank test, P=0.0186 and 0.0408), better than prognostic stratification by tumor staging; and for ESRP1 confirmed with second TCGA cohort (log-rank test, P=0.0435). Prognostic value is independent of the pathological stage and microsatellite instability (ESRP1: HR=0.36, 95%CI 0.15-0.91, P=0.032; ESRP2: HR=0.23, 95%CI 0.08-0.65, P=0.006).Our study supports the role of ESRP1 as tumor suppressor and strongly suggests that ESRPs are candidate markers for early detection, diagnosis, and prognosis of CRC.

The microbiology of Lascaux Cave

Lascaux Cave (Montignac, France) contains paintings from the Upper Paleolithic period. Shortly after its discovery in 1940, the cave was seriously disturbed by major destructive interventions. In 1963, the cave was closed due to algal growth on the walls. In 2001, the ceiling, walls and sediments were colonized by the fungus Fusarium solani. Later, black stains, probably of fungal origin, appeared on the walls. Biocide treatments, including quaternary ammonium derivatives, were extensively applied for a few years, and have been in use again since January 2008. The microbial communities in Lascaux Cave were shown to be composed of human-pathogenic bacteria and entomopathogenic fungi, the former as a result of the biocide selection. The data show that fungi play an important role in the cave, and arthropods contribute to the dispersion of conidia. A careful study on the fungal ecology is needed in order to complete the cave food web and to control the black stains threatening the Paleolithic paintings.

Decellularized, xenogeneic small-diameter arteries: transition from a muscular to an elastic phenotype in vivo

Reports regarding the biocompatibility of xenogeneic, decellularized bioprosthetic implants differ between bioinertness and complete graft degradation. We investigated heparin-crosslinked and nonheparinized, xenogeneic vascular substitutes in a rat model. Porcine arteries (15 x 1.5 mm) were decellularized by multistep detergent and enzymatic techniques, which were followed by heparin-crosslinking in 50% of the implants. Prostheses were implanted into the abdominal aorta of 76 rats for 1 day and up to 6 months. Retrieved specimens were evaluated by histology, immunohistochemistry, laser scanning, and scanning electron microscopy. Graft patency did not differ between groups (97.3%). Heparinized grafts showed a statistically significant lower rate of aneurysm formation (p = 0.04 %). Implants revealed infiltration with granulocytes and macrophages up to 3 months. Recellularization with endothelial cells and myofibroblasts was detectable within 1 month. After 6 months elastin biosynthesis and complete graft remodeling toward an elastic vessel was evident. These results indicate that temporary inflammation does not interfere with long-term vascular remodeling.

Stem-loop structures II-IV of the 5' untranslated sequences are required for the expression of the full-length hepatitis C virus genome

The 5' and 3' untranslated regions (UTR) of the hepatitis C virus (HCV) genome contain stem-loop structures, which are important in viral gene expression and replication. In this study, the functional roles of the predicted stem-loop structures of HCV 5' UTR and 3' UTR in viral gene expression were examined using a chimeric clone of full-length HCV genomic cDNA clone and the gene for green fluorescent protein (GFP). High level expression of the HCV-GFP chimera in Huh-7 cells was accomplished by using a replication defective adenovirus that expresses T7 RNA polymerase and transcription plasmid containing full-length HCV-GFP chimera under the control of a T7 promoter. The HCV-GFP clone, with deletion of stem-loop I, expressed proteins in transfected Huh-7 cells at comparable levels to the wild type HCV clone. Other mutations of the 5' UTR, which either deleted or altered the base pairing of stem-loops II to IV, completely abolished the expression of HCV-GFP chimera. In contrast, deletion of 3' UTR sequences had no effect on HCV protein expression. These findings suggest that the stem-loop structures II to IV of HCV 5' UTR are necessary for protein expression, but that stem loop I is dispensable for protein translation. The stem-loop structures of 3' UTR of HCV genome appear to have no direct role in viral gene expression.

Creutzfeldt-Jakob disease in a husband and wife

A 53-year-old man died of sporadic Creutzfeldt-Jakob disease (CJD) after a 1.5-year clinical course. Four and a half years later, his then 55-year-old widow died from CJD after a 1-month illness. Both patients had typical clinical and neuropathologic features of the disease, and pathognomonic proteinase-resistant amyloid protein ("prion" protein, or PrP) was present in both brains. Neither patient had a family history of neurologic disease, and molecular genetic analysis of their PrP genes was normal. No medical, surgical, or dietary antecedent of CJD was identified; therefore, we are left with the unanswerable alternatives of human-to-human transmission or the chance occurrence of sporadic CJD in a husband and wife.

Vein, silastic, and polyglycolic acid fine mesh: a comparative study in peripheral nerve repair

We investigated three sheathing materials (autogenous vein, silastic, and polyglycolic acid fine mesh) using the rat model. Forty rats were divided into five groups of eight animals each. Group A animals underwent transection of the sciatic nerve but had no repair. In Group B, a standard epineural repair was performed. In Groups C, D, and E, the nerve was repaired as in Group B with the addition of autogenous vein, Silastic, and polyglycolic acid fine mesh sheaths, respectively. Nerve regeneration and function were assessed using sciatic functional index, nerve conduction studies, and light microscopy. Sheathing methods showed no statistically significant advantage to standard epineural repair without a sheath.

Myopathy in Marinesco-Sjogren syndrome

Progressive muscular weakness, hypotonia and atrophy are among the cardinal signs of the Marinesco-Sjogren syndrome but have not been extensively investigated. Our study focused on 6 related patients who are members of an inbred population. Muscle biopsies revealed myopathic alterations with variation of fiber size, rounding, degeneration and regeneration of fibers, internalization of nuclei and endomysial fat and fibrosis. Most patients had elevated serum creatine kinase levels. One patient revealed endstage neuromuscular disease and had normal serum creatine kinase levels. Of particular interest was the finding of conspicuous myopathy in 2 young children. Thus far, it has not been appreciated that myopathy represents an early sign of the Marinesco-Sjogren syndrome.