Open Surgical versus Minimal Invasive Necrosectomy of the Pancreas-A Retrospective Multicenter Analysis of the German Pancreatitis Study Group

Background Necrotising pancreatitis, and particularly infected necrosis, are still associated with high morbidity and mortality. Since 2011, a step-up approach with lower morbidity rates compared to initial open necrosectomy has been established. However, mortality and complication rates of this complex treatment are hardly studied thereafter. Methods The German Pancreatitis Study Group performed a multicenter, retrospective study including 220 patients with necrotising pancreatitis requiring intervention, treated at 10 hospitals in Germany between January 2008 and June 2014. Data were analysed for the primary endpoints "severe complications" and "mortality" as well as secondary endpoints including "length of hospital stay", "follow up", and predisposing or prognostic factors. Results Of all patients 13.6% were treated primarily with surgery and 86.4% underwent a step-up approach. More men (71.8%) required intervention for necrotising pancreatitis. The most frequent etiology was biliary (41.4%) followed by alcohol (29.1%). Compared to open necrosectomy, the step-up approach was associated with a lower number of severe complications (primary composite endpoint including sepsis, persistent multiorgan dysfunction syndrome (MODS) and erosion bleeding: 44.7% vs. 73.3%), lower mortality (10.5% vs. 33.3%) and lower rates of diabetes mellitus type 3c (4.7% vs. 33.3%). Low hematocrit and low blood urea nitrogen at admission as well as a history of acute pancreatitis were prognostic for less complications in necrotising pancreatitis. A combination of drainage with endoscopic necrosectomy resulted in the lowest rate of severe complications. Conclusion A step-up approach starting with minimal invasive drainage techniques and endoscopic necrosectomy results in a significant reduction of morbidity and mortality in necrotising pancreatitis compared to a primarily surgical intervention

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ISSN:0948-3349ISSN:1614-750

Copy Number Variants in German Patients with Schizophrenia

Large rare copy number variants (CNVs) have been recognized as significant genetic risk factors for the development of schizophrenia (SCZ). However, due to their low frequency (1∶150 to 1∶1000) among patients, large sample sizes are needed to detect an association between specific CNVs and SCZ. So far, the majority of genome-wide CNV analyses have focused on reporting only CNVs that reached a significant P-value within the study cohort and merely confirmed the frequency of already-established risk-carrying CNVs. As a result, CNVs with a very low frequency that might be relevant for SCZ susceptibility are lost for secondary analyses. In this study, we provide a concise collection of high-quality CNVs in a large German sample consisting of 1,637 patients with SCZ or schizoaffective disorder and 1,627 controls. All individuals were genotyped on Illumina's BeadChips and putative CNVs were identified using QuantiSNP and PennCNV. Only those CNVs that were detected by both programs and spanned ≥30 consecutive SNPs were included in the data collection and downstream analyses (2,366 CNVs, 0.73 CNVs per individual). The genome-wide analysis did not reveal a specific association between a previously unknown CNV and SCZ. However, the group of CNVs previously reported to be associated with SCZ was more frequent in our patients than in the controls. The publication of our dataset will serve as a unique, easily accessible, high-quality CNV data collection for other research groups. The dataset could be useful for the identification of new disease-relevant CNVs that are currently overlooked due to their very low frequency and lack of power for their detection in individual studies

Studies on the impact of probiotic bacteria on enteric microbial diversity and immune response

The mechanism of action of probiotics is based on competitive exclusion and immune modulation. However, the literature is scant on supporting data because of the failure to adopt a systems approach to probiotic functionality. This has been partially addressed in this thesis by taking into consideration the tripartite interaction between bacteria and bacteria in the enteric community; between bacteria and the host animal and finally, between the host immune response (innate or acquired) on the plethora of microbes that inhabit the gastrointestinal tract. A trial involving newly inducted cattle in a feedlot, formed the basis of initial attempts to assess the benefits of a commercial probiotic formulation - Protexin on intestinal health by enumeration of a select subset of cultivable bacteria species and by assessment of immune modulation. The results failed to demonstrate a significant change in the population dynamics of cultured faecal microbes but did show that Protexin stimulated immune responsiveness in T cells. Carcass analysis demonstrated a significant reduction in marbling or intramuscular fat deposition. In the course of examining the faecal microflora from feedlot cattle, the presence of high levels of Bacillus spores suggested that one possible reason for the lack of a growth benefit may be attributed to a high endogenous level of bacilli. Since there were no reliable methodologies for identifying Bacillus species, an alternative procedure was developed involving amplified ribosomal DNA restriction analysis (ARDRA). With this protocol, we were able to show that cattle faeces contained large numbers of Bacillus spores representing different mesophilic species, where B. subtilis, B. licheniformis and B. clausii dominated. The presence of a stable population of coliforms in cattle faeces that was not altered by probiotic feeding highlighted the importance of developing better techniques to characterise diversity in E. coli, a potential food-borne pathogen of economic significance to the cattle industry. The use of virulence genes to genotype coliforms provided a method for differentiating between pathogenic, clinical and commensal isolates of E. coli. Altogether, a combination of uni- and multiplex PCR assays was developed to screen for 50 virulence genes (VGs) from 8 pathotypes of E. coli. There was a significant association between phylogroupings and VG ownership. This result showed clearly that the lack of or possession of VGs in member isolates of each phylogenetic group can be used to assess diversity and potential pathogenesis of E. coli. To understand better the importance of pathogenic enteric coliforms, an alternative animal model involving pigs with post-weaning diarrhoea was used to investigate the relationship between pathogenicity and commensalism by VG profiling. Porcine enterotoxigenic E. coli (ETEC) were found to carry VGs identified in E. coli that cause extraintestinal infection. Furthermore, by using the appropriate methods of statistical analysis, VG profiling had the capacity to predict the pathogenic and commensal status of individual clones. By developing the capacity to rapidly characterise and genotype virulence and commensalism in E. coli, it is now feasible to examine how probiotic feeding can modulate the population dynamics of different community members in pigs with enteric disease, as well as changes in the coliform populations. Finally, another arm of the tripartite interaction involving bacteria and host interaction was modelled in vitro by examining the primary signalling events between bacteria and intestinal epithelial cells. These investigations focused on the judicious selection of T84 as the reporter intestinal epithelial cell line because of low level expression of inflammatory transcripts from 6 other epithelial cell lines. Using a panel of coliforms genotyped for virulence or lack of virulence, the signalling events that followed on from the primary interaction between bacterium and cell, showed there was a lack of correlation between VGs and gene activation. Nonetheless, all the coliform strains tested varied in their capacity to signal transduce T84, confirming that this differential bioactivity can be exploited in the ranking of candidate probiotic strains. The differential responses seen with different E. coli strains and the lower and more consistent activation patterns recorded by LABs for both cytokine and chemokine gene activation, demonstrate that a semi-quantitative ranking of microbial bioactivity can be obtained. Such an approach if adopted in conjunction with an even wider panel of genes in a standardised in vitro environment can provide invaluable information on the selection of appropriate strains to be further tested in vivo

Open Surgical versus Minimal Invasive Necrosectomy of the Pancreas-A Retrospective Multicenter Analysis of the German Pancreatitis Study Group.

Necrotising pancreatitis, and particularly infected necrosis, are still associated with high morbidity and mortality. Since 2011, a step-up approach with lower morbidity rates compared to initial open necrosectomy has been established. However, mortality and complication rates of this complex treatment are hardly studied thereafter.The German Pancreatitis Study Group performed a multicenter, retrospective study including 220 patients with necrotising pancreatitis requiring intervention, treated at 10 hospitals in Germany between January 2008 and June 2014. Data were analysed for the primary endpoints "severe complications" and "mortality" as well as secondary endpoints including "length of hospital stay", "follow up", and predisposing or prognostic factors.Of all patients 13.6% were treated primarily with surgery and 86.4% underwent a step-up approach. More men (71.8%) required intervention for necrotising pancreatitis. The most frequent etiology was biliary (41.4%) followed by alcohol (29.1%). Compared to open necrosectomy, the step-up approach was associated with a lower number of severe complications (primary composite endpoint including sepsis, persistent multiorgan dysfunction syndrome (MODS) and erosion bleeding: 44.7% vs. 73.3%), lower mortality (10.5% vs. 33.3%) and lower rates of diabetes mellitus type 3c (4.7% vs. 33.3%). Low hematocrit and low blood urea nitrogen at admission as well as a history of acute pancreatitis were prognostic for less complications in necrotising pancreatitis. A combination of drainage with endoscopic necrosectomy resulted in the lowest rate of severe complications.A step-up approach starting with minimal invasive drainage techniques and endoscopic necrosectomy results in a significant reduction of morbidity and mortality in necrotising pancreatitis compared to a primarily surgical intervention

Investigation of the involvement of MIR185 and its target genes in the development of schizophrenia

BACKGROUND: Schizophrenia is a complex neuropsychiatric disorder of unclear etiology. The strongest known genetic risk factor is the 22q11.2 microdeletion. Research has yet to confirm which genes within the deletion region are implicated in schizophrenia. The minimal 1.5 megabase deletion contains MIR185, which encodes microRNA 185. METHODS: We determined miR-185 expression in embryonic and adult mouse brains. Common and rare variants at this locus were then investigated using a human genetics approach. First, we performed gene-based analyses for MIR185 common variants and target genes using Psychiatric Genomics Consortium genome-wide association data. Second, MIR185 was resequenced in German patients (n = 1000) and controls (n = 500). We followed up promising variants by genotyping an additional European sample (patients, n = 3598; controls, n = 4082). RESULTS: In situ hybridization in mice revealed miR-185 expression in brain regions implicated in schizophrenia. Gene-based tests revealed association between common variants in 3 MIR185 target genes (ATAT1, SH3PXD2A, NTRK3) and schizophrenia. Further analyses in mice revealed overlapping expression patterns for these target genes and miR-185. Resequencing identified 2 rare patient-specific novel variants flanking MIR185. However, follow-up genotyping provided no further evidence of their involvement in schizophrenia. LIMITATIONS: Power to detect rare variant associations was limited. CONCLUSION: Human genetic analyses generated no evidence of the involvement of MIR185 in schizophrenia. However, the expression patterns of miR-185 and its target genes in mice, and the genetic association results for the 3 target genes, suggest that further research into the involvement of miR-185 and its downstream pathways in schizophrenia is warranted

CNVs in regions previously associated with SCZ.

<p>SCZ, schizophrenia; del, microdeletion; dup, microduplication; P, P-value; OR, odds ratio. Position according to NCBI built 36; all P-values and ORs were calculated using Fisher's exact test.</p><p>Two of the patients with a deletion in 1q21.1 and one patient with a deletion in 15q11.2 were already reported by Stefansson et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064035#pone.0064035-Stefansson1" target="_blank">[3]</a>, three patients with a deletion in Neurexin were included in Rujescu et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064035#pone.0064035-Rujescu1" target="_blank">[5]</a> and two patients with a deletion and one patient with a duplication in 16p13.11 were part of the study performed by Ingason et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064035#pone.0064035-Ingason1" target="_blank">[10]</a>.</p

Phenotypic information of patients with a CNV in regions previously associated with SCZ.

<p>Chr, chromosome; DEL, deletion; DUP, duplication; Diagnosis, DSM-IV diagnosis; f, female; m, male; AAO, age-at-onset; Family history SCZ, any fist degree relative with schizophrenia; ., missing data; Position according to NCBI built 36.</p