Bacterial translocation and infected pancreatic necrosis in acute necrotizing pancreatitis derives from small bowel rather than from colon

Background

The clinical course of acute necrotizing pancreatitis (ANP) is determined by the superinfection of pancreatic necrosis. To date, the pathophysiology of the underlying bacterial translocation is poorly understood. The present study investigated the bacterial source of translocation.

Methods

A terminal loop ileostomy was applied in rats. Selective digestive decontamination (SDD) of either the small bowel or the colon was performed. After 3 days of SDD, severe ANP was induced. At 24 hours, bacterial translocation was assessed by cultures of bowel mucosa, mesenteric lymph nodes, and pancreas using a scoring system (0-4).

Results

Without SDD, pancreatic infection was present in all cases with an average score of 2.67. Colon SDD reduced pancreatic superinfection to 1.67 (not significant). SDD of the small bowel significantly reduced superinfection to 1.0 (P < .005).

Conclusions

Bacterial translocation from the colon is less frequent than translocation from the small bowel. Thus, the small bowel seems to be the major source of enteral bacteria in infected pancreatic necrosis.     

Adoptive transfer of cytotoxic T-cells for treatment of residual disease after irradiation

Purpose: To evaluate whether immunotherapy based on adoptively transferred cytotoxic T-cells (CTL) can improve the antitumour efficacy of irradiation.

Material and methods: The experiments were performed using the human squamous cell carcinoma line UT-SCC-15, which expresses human leukocyte antigen (HLA)-A2. The UT-SCC-15 cell-mediated activation of JB4 CTL in terms of interferon (IFN)-γ secretion and cytotoxic potential was determined by enzyme-linked immunosorbent assay and chromium release assay, the perforin content of JB4 cells by flow cytometry. In vivo, tumours were irradiated with 14 Gy. Subsequently, JB4 CTL were injected intra- and peritumourally. Volume doubling times were calculated as a marker of tumour growth delay.

Results: UT-SCC-15 tumour cells were well recognized by JB4 CTL in vitro, as indicated by profound IFN-γ secretion and tumour cell lysis. This response was completely abrogated in the presence of an anti-HLA-A2 antibody. In vivo, adoptive transfer of JB4 CTL after irradiation did not delay tumour growth in comparison to irradiation alone. As a possible underlying mechanism, a loss of perforin content and cytolytic function of the CTL in the absence of interleukin (IL)- 2 or IL-15 was found in vitro.

Conclusion: HLA-A2-alloreactive JB4 cells efficiently recognize and destroy UT-SCC-15 tumour cells in vitro. However, the intratumoural application of JB4 cells after irradiation does not enhance the in vivo effect of radiotherapy alone, which might be caused by the reduced cytotoxic potential of JB4 cells in the absence of IL-2 or IL-15. Thus, co-administration of these cytokines might improve the efficacy of combined irradiation and CTL treatment.     

Onset of labour: women’s experiences and midwives’ assessments in relation to first stage duration

Aim  

The study aimed to assess the time of labour onset and its symptoms as perceived by women in labour and midwives, and the relationship between these and first stage duration.     

Validation of a DNA mixture statistics tool incorporating allelic drop-out and drop-in

DNA mixture analysis is a current topic of discussion in the forensics literature. Of particular interest is how to approach mixtures where allelic drop-out and/or drop-in may have occurred. The Office of Chief Medical Examiner (OCME) of The City of New York has developed and validated the Forensic Statistical Tool (FST), a software tool for likelihood ratio analysis of forensic DNA samples, allowing for allelic drop-out and drop-in. FST can be used for single source samples and for mixtures of DNA from two or three contributors, with or without known contributors. Drop-out and drop-in probabilities were estimated empirically through analysis of over 2000 amplifications of more than 700 mixtures and single source samples. Drop-out rates used by FST are a function of the Identifiler^® locus, the quantity of template DNA amplified, the number of amplification cycles, the number of contributors to the sample, and the approximate mixture ratio (either unequal or approximately equal). Drop-out rates were estimated separately for heterozygous and homozygous genotypes. Drop-in rates used by FST are a function of number of amplification cycles only.FST was validated using 454 mock evidence samples generated from DNA mixtures and from items handled by one to four persons. For each sample, likelihood ratios (LRs) were computed for each true contributor and for each profile in a database of over 1200 non-contributors. A wide range of LRs for true contributors was obtained, as true contributors’ alleles may be labeled at some or all of the tested loci. However, the LRs were consistent with OCME's qualitative assessments of the results. The second set of data was used to evaluate FST LR results when the test sample in the prosecution hypothesis of the LR is not a contributor to the mixture. With this validation, we demonstrate that LRs generated using FST are consistent with, but more informative than, OCME's qualitative sample assessments and that LRs for non-contributors are appropriately assigned.     

Induction of hyporesponsiveness to an early post-binding effect of tumor necrosis factor by tumor necrosis factor itself and interleukin 1.

Modulation of cellular responsiveness to tumor necrosis factor (TNF) was studied in the human SV-80 cells. A marked cytocidal effect is exhibited by these cells at about 4 to 8 h after application of TNF together with protein synthesis inhibitors. Sensitivity of the cells to TNF toxicity was shown to be markedly decreased following their pretreatment with TNF itself or with interleukin (IL) 1 in the absence of protein synthesis inhibitors. The SV-80 cells respond to TNF also with enhanced phosphorylation of the small heat-shock protein, HSP27. This TNF effect is much more rapid than the cytocidal effect; it is observed within minutes of TNF application. The response to this effect, just like the response to the cytocidal effect, is markedly decreased following preexposure of the cells to either TNF or IL 1. Responsiveness to both effects of TNF is regained at the same time, about 15 to 20 h following removal of TNF or IL 1. The decrease in responsiveness after pretreatment with TNF or IL 1 does not reflect an inability of the pretreated cells to bind TNF. Although there is an initial decrease in TNF binding after such pretreatment, it is fully reversed already about 5 h following removal of the cytokines. The rate of uptake of TNF by the pretreated cells is also normal. In view of the rapidity of the effect of TNF on the phosphorylation of HSP27, it seems likely that the observed hyporesponsiveness reflects impairment of an early step in a signaling pathway, perhaps common to both the stimulation of phosphorylation and the induction of cell death by TNF. By restricting the duration of the effects of TNF this desensitization mechanism may safeguard against harmful consequences of these effects.     

Identification of 36 novel Jagged1 (JAG1) mutations in patients with Alagille syndrome

Alagille syndrome (AGS) is an autosomal dominant disorder characterized by five major symptoms: cholestasis, vertebral deformity, heart malformations, ocular defects and peculiar facial appearance. The previously described Jagged1 (JAG1) gene on chromosome 20p12 has been identified as being responsible for AGS. JAG1 encodes a transmembrane protein acting as ligand for the evolutionarily conserved Notch signaling pathway. Here we report 36 novel mutations in the JAG1 gene. We identified 12 novel deletions, 4 insertions, 8 missense, 7 nonsense and 5 splice site mutations. All mutations map to the sequence encoding the extracellular part of the Jagged1 protein. The mutations spread over the entire gene with slightly increased rates in exons 2 to 6 and exon 23 and 24. Eight novel missense mutations map to the Delta-Serrate-Lag2 (DSL) domain and adjacent sequences which are important for ligand-receptor interaction. Inheritance was determined in 27 families. Sixteen mutations (55%) were de novo and eleven mutations (45%) were transmitted. Altogether 226 different JAG1 mutations have been described in association with AGS, including our novel 36 mutations. AGS variants are spread over the entire gene with only a few mutations in exon 26. A relatively high number of mutations are clustered in exons 2 to 6. This sequence region shows high interspecies conservation and encodes the Notch receptor-binding region (DSL domain).     

Outcome measures in studies on the use of oxytocin for the treatment of delay in labour: A systematic review

Objectives

to identify primary and secondary outcome measures in randomised trials, and systematic reviews of randomised trials, measuring effectiveness of oxytocin for treatment of delay in the first and second stages of labour, and to identify any positive health-focussed outcomes used.

Design

eight relevant citation databases were searched up to January 2013 for all randomised trials, and systematic reviews of randomised trials, measuring effectiveness of oxytocin for treatment of delay in labour. Trials of active management of labour or partogram action lines were excluded. 1918 citations were identified. Two reviewers reviewed all citations and extracted data. Twenty-six individual trials and five systematic reviews were included. Primary and secondary outcome measures were documented and analysed using frequency distributions.

Findings

most frequent primary outcomes were caesarean section (n=15, 46%), length of labour (n=14, 42%), measurements of uterine activity (n=13, 39%) and mode of vaginal birth (n=9, 27%). Maternal satisfaction was identified a priori by one review and included as a secondary outcome by three papers. No further positive health-focussed outcomes were identified.

Key conclusions

outcomes used to measure the effectiveness of oxytocin for treatment of delay in labour are heterogeneous and tend to focus on adverse events.

Implications for practice

it is recommended that, in future randomised trials of oxytocin use for delay in labour, some women-centred and health-focussed outcome measures should be used, which may instil a more salutogenic culture in childbirth.