Report from the 17th Annual Western Canadian Gastrointestinal Cancer Consensus Conference; Edmonton, Alberta; 11-12 September 2015.

The 17th annual Western Canadian Gastrointestinal Cancer Consensus Conference (wcgccc) was held in Edmonton, Alberta, 11-12 September 2015. The wcgccc is an interactive multidisciplinary conference attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purposes of developing the recommendations presented here. This consensus statement addresses current issues in the management of gastric cancer.

A cell model for conditional profiling of androgen-receptor-interacting proteins.

Partial androgen insensitivity syndrome (PAIS) is associated with impaired male genital development and can be transmitted through mutations in the androgen receptor (AR). The aim of this study is to develop a cell model suitable for studying the impact AR mutations might have on AR interacting proteins. For this purpose, male genital development relevant mouse cell lines were genetically modified to express a tagged version of wild-type AR, allowing copurification of multiprotein complexes under native conditions followed by mass spectrometry. We report 57 known wild-type AR-interacting proteins identified in cells grown under proliferating and 65 under nonproliferating conditions. Of those, 47 were common to both samples suggesting different AR protein complex components in proliferating and proliferation-inhibited cells from the mouse proximal caput epididymus. These preliminary results now allow future studies to focus on replacing wild-type AR with mutant AR to uncover differences in protein interactions caused by AR mutations involved in PAIS.

CD8 blockade promotes the expansion of antigen-specific CD4+ FOXP3+ regulatory T cells in vivo.

Treatment with a cocktail of CD4 and CD8-specific monoclonal antibodies (mAb) induces long-term transplantation tolerance and regulatory CD4(+) T cells that induce tolerance in non-tolerant T cells. In contrast, treatment with a CD4-specific mAb alone fails to induce long-term tolerance. The current study was designed to test the hypothesis that CD8 blockade plays a role in promoting the development of CD4(+) regulatory T cells. Using the DO11.10 CD4(+) TCR transgenic mouse model we show that treatment with a CD4/CD8-specific mAb cocktail induces antigen-specific tolerance to OVA, measured by a significant decrease in OVA-specific IgG, on challenge with antigen. Although treatment with OVA and the CD4-specific mAb alone also induces a significant decrease in OVA-specific antibody, the number of DO11.10 cells is significantly greater in mice treated with the CD4/CD8-specific mAb cocktail, and this is associated with a significant increase in proliferation of DO11.10 cells in response to specific antigen. DO11.10 cells sorted from mice made tolerant to OVA with the CD4/CD8-specific mAb cocktail promote an OVA-specific IgG1 (Th2-type) response but not an OVA-specific IgG3 (Th1-type) response on transfer into new syngeneic recipients, suggesting their ability to regulate the type of antigen-specific immune response that ensues after priming with antigen. In addition, DO11.10 cells from tolerant mice express markers that are characteristic of CD4(+) regulatory cells, including FOXP3, GITR and CTLA4, but not CD25. Taken as a whole, these data suggest that CD8 blockade promotes CD4(+) FOXP3(+) regulatory CD4(+) T cells by promoting their proliferation in tolerant mice.

Otago Diagnostic Laboratories' (ODL) Method for the detection of beta-lactamases in Enterobacteriaceae.

AIM: The rapid evolvement of beta-lactamases in Enterobacteriaceae is an important concern and the clinical microbiology laboratory is required to detect them, where possible, using a rapid, reliable, simple and low cost methodology. MATERIALS AND METHODS: A disc diffusion method using NCCLS breakpoints, Jarlier's principle and cefoxitin test for AmpC was carried out. It incorporated seven antimicrobial discs in one agar plate: cefotaxime, aztreonam, amoxicillin-clavulanate, ceftazidime, cefpodoxime, cefepime and cefoxitin. NCCLS disc confirmation test for extended-spectrum beta-lactamase (ESBL) was carried out simultaneously. RESULTS: AmpC, ESBL, CTX-M, and K1 were detected using these tests. The prevalence of ESBL was <1% in the hospital. CONCLUSION: The method is recommended for the phenotypic detection of beta-lactamases in Enterobacteriaceae or for confirmation after the results are obtained by conventional automated systems.

Acetylated low-density lipoprotein stimulates human vascular smooth muscle cell calcification by promoting osteoblastic differentiation and inhibiting phagocytosis.

BACKGROUND: Vascular smooth muscle cells (VSMCs) in atherosclerotic lesions display an osteogenic phenotype, and calcification commonly occurs in association with lipid. We therefore tested the hypothesis that lipid components in atherosclerotic lesions influenced VSMC phenotype and calcification using an in vitro model of calcification. METHODS AND RESULTS: In situ hybridization of human atherosclerotic plaques (n=10) collected from patients undergoing carotid endarterectomy demonstrated that subsets of lipid-filled VSMCs adjacent to sites of calcification expressed alkaline phosphatase, bone Gla protein, and bone sialoprotein, suggesting an osteogenic phenotype. Treatment of VSMCs in culture with acetylated low-density lipoprotein (acLDL) or lipoprotein-deficient serum altered the time course of bone-associated protein gene expression and calcification. AcLDL increased nodule calcification 3-fold, whereas lipoprotein-deficient serum significantly inhibited it. Reverse transcriptase-polymerase chain reaction and Western analysis demonstrated the presence of the acLDL receptor, SRA1, exclusively in calcifying nodular VSMCs, and blockade of SRA with polyinosinic acid inhibited acLDL-induced calcification. Because apoptotic bodies can serve as nucleation sites for calcification, we investigated whether acLDL could stimulate apoptosis in nodules. Apoptosis of nodular VSMCs was unaltered, but the number of apoptotic bodies per nodule increased approximately 3-fold, implying a defect in phagocytosis. Consistent with these observations, binding of apoptotic bodies to VSMCs was decreased in the presence of acLDL. CONCLUSIONS: These studies suggest that modified lipoproteins stimulate calcification by enhancing osteogenic differentiation of VSMCs and by a novel mechanism whereby acLDL interacts with SRA on VSMCs and blocks phagocytic removal of apoptotic bodies.

A polymorphism of the human matrix gamma-carboxyglutamic acid protein promoter alters binding of an activating protein-1 complex and is associated with altered transcription and serum levels.

Matrix gamma-carboxyglutamic acid protein (MGP) is a mineral-binding extracellular matrix protein synthesized by vascular smooth muscle cells (VSMCs) and chondrocytes that is thought to be a key regulator of tissue calcification. In this study, we identified four polymorphisms in the promoter region of the human MGP gene. Transfection studies showed that the G-7A and T-138C polymorphisms have an important impact on in vitro promoter activity when transiently transfected into VSMCs. We found that one of these polymorphisms (T-138C) is significantly correlated with serum MGP levels in human subjects. Promoter deletion analysis showed that this polymorphism lies in a region of the promoter critical for transcription in VSMCs. This region contains a potential activating protein-1 (AP-1) binding element located between -142 and -136. We have demonstrated that the T-138C polymorphism results in altered binding of an AP-1 complex to this region. The -138T allelic variant binds AP-1 complexes consisting primarily of c-Jun, JunB and its partners Fra-1 and Fra-2 in rat VSMC. Furthermore, the -138T variant form of the promoter was induced following phorbol 12-myristate 13-acetate treatment, while the -138C variant was refractive to phorbol 12-myristate 13-acetate treatment, confirming that AP-1 factors preferentially bind to the -138T variant. This study therefore suggests that a common polymorphism of the MGP promoter influences binding of the AP-1 complex, which may lead to altered transcription and serum levels. This could have important implications for diseases such as atherosclerosis and aortic valve stenosis, since it strongly suggests a genetic basis for regulation of tissue calcification.

Fat necrosis of the female breast--Hadfield re-visited.

Examination of pathology records from three hospitals over an 8-year period identified 42 cases of primary fat necrosis of the female breast. The mean age of the women was 56 (range 24-85) and the lump was most commonly in the upper, inner quadrant of the breast having been present for a mean of 11 weeks (range 1-56). Twenty-one percent of patients gave a history of trauma which had occurred a mean of 69 weeks (range 3-208) previously. The mammograms gave an appearance of malignancy in 12 of the 22 cases where they were performed. Cytology was suspicious in five cases. Thirty-seven patients subsequently underwent wide local excision to confirm the diagnosis. The histology was re-examined by a pathologist and a subgroup of patients were identified who had fat necrosis associated with periductal mastitis. Two patients who had a core biopsy diagnosis of fat necrosis were found to have malignancy on wide local excision. Here we review the changes in presentation since the original description of the condition, and highlight that although this series reflects difficult cases, fat necrosis remains a condition which can still be difficult to diagnose.

Nesprins: a novel family of spectrin-repeat-containing proteins that localize to the nuclear membrane in multiple tissues.

In search of vascular smooth muscle cell differentiation markers, we identified two genes encoding members of a new family of type II integral membrane proteins. Both are ubiquitously expressed, and tissue-specific alternative mRNA initiation and splicing generate at least two major isoforms of each protein, with the smaller isoforms being truncated at the N-terminus. We have named these proteins nesprin-1 and -2 for nuclear envelope spectrin repeat, as they are characterized by the presence of multiple, clustered spectrin repeats, bipartite nuclear localization sequences and a conserved C-terminal, single transmembrane domain. Transient transfection of EGFP-fusion expression constructs demonstrated their localization to the nuclear membrane with a novel C-terminal, TM-domain-containing sequence essential for perinuclear localization. Using antibodies to nesprin-1, we documented its colocalization with LAP1, emerin and lamins at the nuclear envelope, and immunogold labeling confirmed its presence at the nuclear envelope and in the nucleus where it colocalized with heterochromatin. Nesprin-1 is developmentally regulated in both smooth and skeletal muscle and is re-localized from the nuclear envelope to the nucleus and cytoplasm during C2C12 myoblast differentiation. These data and structural analogies with other proteins suggest that nesprins may function as 'dystrophins of the nucleus' to maintain nuclear organization and structural integrity.

CD4+ CD45RB low-density cells from untreated mice prevent acute allograft rejection.

In the absence of therapy that suppresses the action of the immune system, the immune response to transplantation Ags results in rapid rejection of the transplant. The most successful mechanism so far described that achieves organ-specific immunological tolerance is that which controls peripheral tolerance to self-tissue. Until now, no similarities have been documented between the peripheral response to self-Ags and the response to transplantation Ags. CD4+ cells that express a high density of CD45RB (in the mouse) and CD45RC (in the rat) on their surface have been shown to cause a number of autoimmune disorders. In contrast, autoimmunity caused by the CD45RB high-density cells is inhibited by CD4+ CD45RB cells that express a low density of CD45RB (CD45RC in the rat). In this paper we show that CD4+ CD45RB high-density cells are sufficient to cause rejection of a MHC-mismatched pancreas allograft, whereas CD4+ CD45RB low-density cells are not. Unexpectedly, the CD45RB low-density cells prevent the CD45RBhigh expressing cells from causing rejection. These data suggest that the response to foreign tissue can be controlled in the same way as the response to self-tissue.

Amplification of cytokine-specific ELISAs increases the sensitivity of detection to 5-20 picograms per milliliter.

The ability to detect a protein is always limited to the sensitivity of the assays available. Progress in improving the sensitivity of protein detection will allow a more complete understanding of biological systems. Of particular interest to the field of immunology is the ability to characterize an immune response based upon the pattern of cytokines that are released in response to antigen. A Th1 response is characterized by the presence of IL-2, IL-12, TNF and IFN-gamma, whereas a Th2 response is characterized by IL-4, IL-5, IL-6 and IL-10. Often, these cytokines are present in in vitro-derived culture supernatants at extremely low concentrations and are therefore very difficult to detect. Although a number of improvements have been made to the sensitivity of the relevant detection assays, the most successful assays involve the presence of the cells being cultured thereby limiting the number of tests per culture to one. Here we describe an enhanced ELISA protocol where the sensitivity is equivalent or better than corresponding cell-based assays. This protocol will permit the sensitive measurement of multiple cytokines per single culture supernatant.

An immunoluminometric assay for cardiotrophin-1: a newly identified cytokine is present in normal human plasma and is increased in heart failure.

Cardiotrophin-1, a member of the interleukin-6 related cytokine family which acts via the glycoprotein 130 signalling pathway, may be involved in the process of ventricular remodelling. Its presence in human plasma has never been reported. We have devised a non-radioactive immunoluminometric sensitive and specific assay for CT-1 based on a competitive ligand binding principle. The chemiluminescent label 4-(2-succinimidyl-oxycarbonylethyl)phenyl-10-methylacridinium 9-carboxylate fluorosulfonate was used to label a peptide representing a domain in the middle section of CT-1. Assay of this domain of CT-1 (amino acids 105-120) in patients with heart failure revealed elevated CT-1 values median 87 [range 74.3-182.8] fmol/ml) compared to normal controls (CT-1 median 29.55 [range 6.9-48.3] fmol/ml, P<0.0005). The molecular weight of human CT-1 was estimated to be 26.7 kD from sodium dodecyl sulphate polyacrylamide gel electrophoresis. This is the first quantitative assessment of CT-1 in humans. Furthermore, this is the first demonstration of significant elevation of plasma CT-1 in patients with heart failure.

Pancreatic IL-4 expression results in islet-reactive Th2 cells that inhibit diabetogenic lymphocytes in the nonobese diabetic mouse.

When immunological tolerance breaks down, autoimmune destruction of insulin-producing beta cells in the pancreas can cause insulin-dependent diabetes mellitus. We previously showed that transgenic nonobese diabetic (NOD) mice expressing IL-4 in the pancreas (NOD-IL-4 mice) were protected from insulitis and diabetes. Here we have characterized the avoidance of pathological autoimmunity in these mice. The absence of disease did not result from a lack of T cell priming, because T cells responding to dominant islet Ags were present. These islet Ag-specific T cells displayed a Th2 phenotype, indicating that Th2 responses could account for the observed tolerance. Interestingly, islet Ag-specific Th1 T cells were present and found to be functional, because neutralization of the Th2 effector cytokines IL-4 and IL-10 resulted in diabetes. Histological examination revealed that NOD-IL-4 splenocytes inhibited diabetogenic T cells in cotransfer experiments by limiting insulitis and delaying diabetes. Neutralization of IL-4 in this system abrogated the ability of NOD-IL-4 splenocytes to delay the onset of diabetes. These results indicate that IL-4 expressed in the islets does not prevent the generation of pathogenic islet responses but induces islet Ag-specific Th2 T cells that block the action of diabetogenic T cells in the pancreas.

Interleukin-4 secretion by the allograft fails to affect the allograft-specific interleukin-4 response in vitro.

BACKGROUND: The role of the cytokine, interleukin (IL)-4, in allograft rejection and protection is not clear. We have previously shown that IL-4 transgenically expressed in a pancreas allograft does not protect the allograft from rejection. Here, we analyze the effect of the transgenically expressed IL-4 on the cytokine profile of the allograft-specific immune response. METHODS: C57BL/6SCID mice were infused with small numbers of spleen cells from C57BL/6 donors. The former received pancreas grafts from 1- to 2-day-old BALB/c donors which did or did not transgenically express IL-4 in the graft. Three weeks after the cell infusion, the spleens were removed and the splenocytes were restimulated in vitro with BALB/c APC, and third party BALB.K APC. IL-2 and IL-4 levels in the culture supernatants were measured. RESULTS: The presence of a pancreatic allograft induced an increase in the levels of both IL-2 and IL-4 in culture supernatants from splenocytes of mice receiving grafts compared with mice not receiving grafts. The presence of IL-4 transgenically expressed in the pancreas allograft had no effect on the in vitro cytokine profile. CONCLUSIONS: from these results we conclude that the failure of transgenically expressed IL-4 to protect the allograft was not associated with up-regulation of a graft antigen-specific IL-4 response.

IL-10 impacts autoimmune diabetes via a CD8+ T cell pathway circumventing the requirement for CD4+ T and B lymphocytes.

IL-10 is essential for an early phase of diabetes in nonobese diabetic (NOD) mice, but later becomes protective against its development. The mechanism by which IL-10 mediates the pathway to diabetes in these mice is unknown. Herein, we dissected the cellular and costimulation requirements for diabetes in transgenic (tg) NOD mice that expressed IL-10 in their pancreatic islets (IL-10-NOD mice). We found that IL-10 alone did not cause diabetes because the offspring (IL-10-NOD-scid mice) from back-crosses of IL-10-NOD mice with NOD-scid mice had no diabetes. Moreover, these IL-10-NOD-scid mice were free of lymphocytic infiltration. Treatment of IL-10-NOD mice with depleting anti-CD4 mAb or control mAb had no effect on diabetes. Surprisingly, depletion of CD8+ T cells by treatment with the corresponding mAb inhibited diabetes without attenuating insulitis, demonstrating a critical role for CD8+ T cells in the disease process. Interestingly, B cell-deficient IL-10-NOD mice readily developed diabetes with kinetics and incidence similar to those observed in wild-type mice, demonstrating that B lymphocytes as APCs were not required in the disease process. Administration of anti-CD40 ligand (CD40L) mAb did not prevent disease, indicating that CD40/CD40L costimulation is not required for diabetes in IL-10-NOD mice. Immunization of IL-10-NOD mice with CFA or heat-shock protein 65, known to block diabetes in NOD mice, had no effect on their diabetes. We demonstrate that IL-10 contributes early to the pathology of diabetes via a CD8+ T cell pathway, eliminating the requirement for B lymphocytes and CD40-CD40L costimulation. Our findings provide a mechanism for the participation of IL-10 in the early development of diabetes.

A role for the ETS domain transcription factor PEA3 in myogenic differentiation.

Activation of adult myoblasts called satellite cells during muscle degeneration is an important aspect of muscle regeneration. Satellite cells are believed to be the only myogenic stem cells in adult skeletal muscle and the source of regenerating muscle fibers. Upon activation, satellite cells proliferate, migrate to the site of degeneration, and become competent to fuse and differentiate. We show here that the transcription factor polyomavirus enhancer activator 3 (PEA3) is expressed in adult myoblasts in vitro when they are proliferative and during the early stages of differentiation. Overexpression of PEA3 accelerates differentiation, whereas blocking of PEA3 function delays myoblast fusion. PEA3 activates gene expression following binding to the ets motif most efficiently in conjunction with the transcription factor myocyte enhancer factor 2 (MEF2). In vivo, PEA3 is expressed in satellite cells only after muscle degeneration. Taken together, these results suggest that PEA3 is an important regulator of activated satellite cell function.

IL-4 expression by grafts from transgenic mice fails to prevent allograft rejection.

Cell-mediated tissue destruction, such as that occurring in allograft rejection, is thought to be mediated by Th1 cells and cytokines. We have recently shown that transgenic expression of the Th2 cytokine IL-4 by pancreatic beta cells completely protects nonobese diabetic (NOD) mice from autoimmune diabetes by inducing functional tolerance among autoreactive T cells. To investigate whether local IL-4 production could also induce functional tolerance among alloreactive T cells and thus prevent allograft rejection, we transplanted pancreata from transgenic neonatal mice and their nontransgenic littermates into allogeneic hosts. Within 2 wk, recipient mice had rejected their grafts regardless of the transgene's presence or absence. Considering that the vigorous immune response induced might have prevented any effect by IL-4, we injected recipient mice with anti-CD4 and anti-CD8 mAbs, thereby depleting them of T cells and thus providing the islets with an opportunity to mature and grow. This approach indeed delayed rejection of neonatal pancreata from nontransgenic mice by >1 wk. By that time, however, pancreata from transgenic mice had also been rejected. Our results indicate that the allograft rejection response under these conditions, in contrast to the autoimmune response in NOD mice, cannot be regulated by local IL-4 production, regardless of the cytokine's impact on Th1 cells.

A comparative audit of prevalent, incident and interval cancers in the Avon breast screening programme.

The 4th year of the Avon breast screening programme comprises two distinct groups: those called for screening for the first time (prevalent group) and those who were initially screened 3 years earlier (incident group). The cancer detection rate, stage of disease and rate of interval cancers in these patients have been compared. For the prevalent groups of year 1 and year 4 there was no statistically significant difference in the cancer detection rate, proportion of small tumours or node positivity. For the prevalent and incident groups of year 4, there was no statistically significant difference in the cancer detection rate or proportion of small tumours. There were significantly fewer node-positive tumours in the incident group (5/45 vs 8/23; P < 0.05). Fifty-six interval cancers presented in the 3-year period between years 1 and 4 of screening; 28 (50%) after 24 months. The screening programme may result in tumours being detected at an earlier stage, but this may be offset by the high rate of interval cancers. This suggests that the time between screens may need to be reduced to 2 years.

Strain variation in susceptibility to monoclonal antibody-induced transplantation tolerance.

BACKGROUND: We have reproducibly induced specific tolerance to multiple minor histocompatibility antigens with nondepleting anti-CD4 and -CD8 monoclonal antibodies. The tolerance induced is effective for the lifetime of the host. We have tested this therapy in a number of mouse strain combinations to further understand the mechanisms. METHODS: Various mouse strains were grafted with allogeneic tail skin with and without nondepleting CD4- and CD8-specific monoclonal antibody therapy. The grafts were monitored daily for signs of rejection. RESULTS: Whereas the CBA/Ca (H2k) strain can be made tolerant to skin grafts that are mismatched at multiple minor histocompatibility antigens indefinitely, using the same protocol, long-term survival of similarly mismatched grafts on the HW80 (B6 congenic for BALB H1) mouse strain is limited to around 8 weeks. Interestingly, the B10.BR strain, which is also of the H2k haplotype, is also not readily tolerized. In addition, an F1 between the CBA/Ca and the resistant B10.BR strains is B10.BR-like in its susceptibility to tolerance induction. Susceptibility to such antibody-dependent tolerance induction is not related to immunogenicity because grafts mismatched at only a single minor antigen also do not reproducibly survive beyond 8 weeks when grafted onto HW80 mice in the presence of the antibody therapy. CONCLUSIONS: The data strongly suggest that the B6/B10 genetic background confers a level of resistance to CD4- and CD8-specific monoclonal antibody-dependent tolerance induction.

Cytokeratin demonstration in thick breast tissue slices.

Tissue slices (500 to 1000 microns thick) of archival formalin-fixed, paraffin-embedded breast tissue were immunostained by a cytokeratin antibody (MNF116) using a streptavidin-biotin complex procedure. The technique requires prolonged exposure of tissue slices to the reagents. Use of the detergent Triton X-100 facilitated penetration of high molecular weight reagents through the tissue slices. Fifty of 58 slices 500 microns thick (86%) showed good to excellent immunostaining, and 13 of 20 slices 1000 microns thick (65%) showed similar staining. Omission of the primary antibody eliminated any immunostaining. Comparison with corresponding Haematoxylin staining of the thick slices (the conventional procedure for such breast tissue slices) showed that thick-slice cytokeratin immunostaining markedly improved visualization of the epithelial structure in normal lobules and invasive carcinomas. Although the immunohistochemical technique takes 33 days for completion, the quality of the epithelial images outweighs this disadvantage.

3-D histo-radiographic comparison of surgical clearances of microcalcified lesions in breast localization biopsies.

There is controversy as to the value of the radiological or pathological estimation of surgical clearance of microcalcifying breast lesions. An important part of this issue has been addressed by coordinated three-dimensional radiographic and histological examination of a prospective consecutive series of 40 benign and malignant mammographically detected lesions in surgical breast biopsy specimens containing microcalcifications, including 20 cases of ductal carcinoma in situ. They were radiographed from four viewpoints by means of rotation in a radiolucent tetrahedral container. The planes of histological examination were then chosen to correspond to the radiographic view showing the minimum separation of the edge of the specimen and the outermost microcalcification. There was a close correlation (Spearman ranked) between the least tetrahedral radiographic distance and the corresponding histological distance separating the surgical margin of excision. There were, however, incompatible Wilcoxon signed ranking orders when comparing the least tetrahedral distance or the histological distance with all four single radiographic views, including the conventional specimen radiographic view. Two-dimensional specimen mammography and standardized histological examination are suboptimal and may thus have contributed to confusion as to the value of determining adequate surgical excision of ductal carcinoma in situ of the breast. Although labour-intensive, use of four-view radiography and choice of the appropriate plane of histological examination give a better correlation of the radiographic estimates of surgical clearance with histology than single-view specimen radiography and arbitrary histological sectioning.