Exposure to food allergens through inflamed skin promotes intestinal food allergy through the thymic stromal lymphopoietin-basophil axis.

BACKGROUND Exposure to food allergens through a disrupted skin barrier has been recognized as a potential factor in the increasing prevalence of food allergy. OBJECTIVE We sought to test the immunologic mechanisms by which epicutaneous sensitization to food allergens predisposes to intestinal food allergy. METHODS Mice were epicutaneously sensitized with ovalbumin or peanut on an atopic dermatitis-like skin lesion, followed by intragastric antigen challenge. Antigen-specific serum IgE levels and T(H)2 cytokine responses were measured by ELISA. Expression of type 2 cytokines and mast cell proteases in the intestine were measured by using real-time PCR. Accumulation of basophils in the skin and mast cells in the intestine was examined by using flow cytometry. In vivo basophil depletion was achieved by using diphtheria toxin treatment of Baso-DTR mice. For cell-transfer studies, the basophil population was expanded in vivo by means of hydrodynamic tail vein injection of thymic stromal lymphopoietin (TSLP) cDNA plasmid. RESULTS Sensitization to food allergens through an atopic dermatitis-like skin lesion is associated with an expansion of TSLP-elicited basophils in the skin that promote antigen-specific T(H)2 cytokine responses, increased antigen-specific serum IgE levels, and accumulation of mast cells in the intestine, promoting the development of intestinal food allergy. Critically, disruption of TSLP responses or depletion of basophils reduced the susceptibility to intestinal food allergy, whereas transfer of TSLP-elicited basophils into intact skin promoted disease. CONCLUSION Epicutaneous sensitization on a disrupted skin barrier is associated with accumulation of TSLP-elicited basophils, which are necessary and sufficient to promote antigen-induced intestinal food allergy.

Angiomatous kaposi sarcoma: a variant that mimics hemangiomas.

We describe 14 cases of angiomatous Kaposi sarcoma (KS), a distinct histological variant of KS first mentioned by Gottlieb and Ackerman in 1988 that can easily be mistaken for a hemangioma. Intriguingly, this variant of KS has not attracted much attention and has not been studied in detail. Immunohistochemistry showed prominent staining of podoplanin (D2-40) of the neoplastic vasculature but not the preexisting vessels, suggesting lymphatic differentiation, despite the erythrocyte-filled round lumens. To test whether D2-40 staining of round vessels with erythrocytes was distinctive, we stained sinusoidal hemangiomas and cellular angiolipomas, both of which have these structures. In contrast to angiomatous KS, the vessels in both entities were podoplanin (D2-40) negative. The finding of round erythrocyte-filled vessels with podoplanin (D2-40) positivity may be distinctive for this form of KS.

Support of hepatic regeneration by trophic factors from liver-derived mesenchymal stromal/stem cells

Mesenchymal stromal/stem cells (MSCs) have multilineage differentiation potential and as such are known to promote regeneration in response to tissue injury. However, accumulating evidence indicates that the regenerative capacity of MSCs is not via transdifferentiation but mediated by their production of trophic and other factors that promote endogenous regeneration pathways of the tissue cells. In this chapter, we provide a detailed description on how to obtain trophic factors secreted by cultured MSCs and how they can be used in small animal models. More specific, in vivo models to study the paracrine effects of MSCs on regeneration of the liver after surgical resection and/or ischemia and reperfusion injury are described.

Bone marrow-derived mesenchymal stromal cells improve vascular regeneration and reduce leukocyte-endothelium activation in critical ischemic murine skin in a dose-dependent manner

BACKGROUND AIMS Stem cells participate in vascular regeneration following critical ischemia. However, their angiogenic and remodeling properties, as well as their role in ischemia-related endothelial leukocyte activation, need to be further elucidated. Herein, we investigated the effect of bone marrow-derived mesenchymal stromal cells (BM-MSCs) in a critically ischemic murine skin flap model. METHODS Groups received either 1 × 10(5), 5 × 10(5), or 1 × 10(6) BM-MSCs or cell-free conditioned medium (CM). Controls received sodium chloride. Intravital fluorescence microscopy was performed for morphological and quantitative assessment of micro-hemodynamic parameters over 12 days. RESULTS Tortuosity and diameter of conduit-arterioles were pronounced in the MSC groups (P < 0.01), whereas vasodilation was shifted to the end arteriolar level in the CM group (P < 0.01). These effects were accompanied by angiopoietin-2 expression. Functional capillary density and red blood cell velocity were enhanced in all treatment groups (P < 0.01). Although a significant reduction of rolling and sticking leukocytes was observed in the MSC groups with a reduction of diameter in postcapillary venules (P < 0.01), animals receiving CM exhibited a leukocyte-endothelium interaction similar to controls. This correlated with leukocyte common antigen expression in tissue sections (P < 0.01) and p38 mitogen-activated protein kinase expression from tissue samples. Cytokine analysis from BM-MSC culture medium revealed a 50% reduction of pro-inflammatory cytokines (interleukin [IL]-1β, IL-6, IL-12, tumor necrosis factor-α, interferon-γ) and chemokines (keratinocyte chemoattractant, granulocyte colony-stimulating factor) under hypoxic conditions. DISCUSSION We demonstrated positive effects of BM-MSCs on vascular regeneration and modulation of endothelial leukocyte adhesion in critical ischemic skin. The improvements after MSC application were dose-dependent and superior to the use of CM alone.

Pulmonary intimal sarcoma: a rare differential diagnosis for arterial filling defects on a chest CT

We present a rare case of pulmonary intimal sarcoma mimicking pulmonary embolism in a 40-year-old woman. Although extremely rare, these tumors must be considered in patients who present inappropriate imaging findings that suggest embolism. Chest computed tomography is the modality of choice to determine the extent of the tumor. We present a female patient with suspected embolism that was in fact found to be an endothelial sarcoma of the pulmonary arteries.

Lymph node stromal cells negatively regulate antigen-specific CD4+ T cell responses

Lymph node (LN) stromal cells (LNSCs) form the functional structure of LNs and play an important role in lymphocyte survival and the maintenance of immune tolerance. Despite their broad spectrum of function, little is known about LNSC responses during microbial infection. In this study, we demonstrate that LNSC subsets display distinct kinetics following vaccinia virus infection. In particular, compared with the expansion of other LNSC subsets and the total LN cell population, the expansion of fibroblastic reticular cells (FRCs) was delayed and sustained by noncirculating progenitor cells. Notably, newly generated FRCs were preferentially located in perivascular areas. Viral clearance in reactive LNs preceded the onset of FRC expansion, raising the possibility that viral infection in LNs may have a negative impact on the differentiation of FRCs. We also found that MHC class II expression was upregulated in all LNSC subsets until day 10 postinfection. Genetic ablation of radioresistant stromal cell-mediated Ag presentation resulted in slower contraction of Ag-specific CD4(+) T cells. We propose that activated LNSCs acquire enhanced Ag-presentation capacity, serving as an extrinsic brake system for CD4(+) T cell responses. Disrupted function and homeostasis of LNSCs may contribute to immune deregulation in the context of chronic viral infection, autoimmunity, and graft-versus-host disease.

The contribution of intrabolus pressure to symptoms induced by gastric banding

BACKGROUND & AIMS Mechanisms that ultimately lead to dysphagia are still not totally clear. Patients with laparoscopic gastric banding (LAGB) often complain about dysphagia, regurgitation and heartburn. Our aim was to evaluate the contribution of intrabolus pressure to symptoms of gastric banding. METHODS This study investigated 30 patients with LAGB before and 3 months after conversion to Roux-en-Y gastric bypass (RYGB), evaluating symptoms with a 7-point-Likert-scale and esophageal peristalsis, esophageal bolus transit and intrabolus pressure changes using combined impedance-manometry. RESULTS Conversion from LAGB to RYGB leads to a significant reduction in dysphagia (1.9 +/- 0.4 vs. 0.0 +/- 0.0; p< 0.01) and regurgitation (4.2 +/- 0.4 vs. 0.1 +/- 0.1; p< 0.01) symptom scores. For liquid swallows we found a modest but significant correlation between the intensity of dysphagia and intrabolus pressure (r=0.11; p<0.05) and the intensity of regurgitation and intrabolus pressure for viscous swallows (r=0.12, p<0.05) in patients with LAGB. There was a significant (p< 0.05) reduction in intrabolus pressure at 5 cm above LES before (liquid 10.6 +/-1.0; viscous 13.5 +/- 1.5) and after (liquid 6.4 +/- 0.6; viscous 10.5 +/- 0.9) conversion from LAGB to RYGB. CONCLUSION Current data suggest that intraesophageal pressure during bolus presence in the distal esophagus contributes to the development but not to the intensity of dysphagia and regurgitation.

Does somatostatin or gastric inhibitory peptide receptor expression correlate with tumor grade and stage in gut neuroendocrine tumors?

BACKGROUND/AIMS Important characteristics of neuroendocrine neoplasms (NEN) for prognosis and therapeutic decisions are the MIB-1 proliferative index (tumor grade) and tumor stage. Moreover, these tumors express peptide hormone receptors like somatostatin and gastric inhibitory peptide (GIP) receptors which represent important established and potential future targets, respectively, for molecular imaging and radiotherapy. However, the interrelation between tumor proliferation, stage, and peptide receptor amounts has never been assessed. METHODS In 114 gastrointestinal and bronchopulmonary NEN, the proliferative rate assessed with MIB-1 immunohistochemistry and tumor stage were compared with the somatostatin type 2 receptor (sst2) and GIP receptor expression measured quantitatively with in vitro receptor autoradiography. RESULTS NEN generally showed high sst2 and GIP receptor expression. GIP receptor but not sst2 expression correlated with the MIB-1 index. GIP receptor levels gradually increased in a subset of insulinomas and nonfunctioning pancreatic NEN, and decreased in ileal and bronchopulmonary NEN with increasing MIB-1 rate. MIB-1 levels were identified, above which GIP receptor levels were consistently high or low. These MIB-1 levels were clearly different from those defining tumor grade. In grade 3 NEN, GIP receptor levels were always low, while sst2 levels were variable and sometimes extremely high. Conversely, sst2 expression correlated more frequently with tumor stage than GIP receptor expression, with metastasized NEN showing higher sst2 levels than localized tumors. CONCLUSIONS sst2, a clinically crucial molecular target, shows variable and unpredictable expression in NEN irrespective of tumor grade. Therefore, each NEN should be tested for sst2 if clinical applications with somatostatin analogs are considered. Conversely, the potential future role of GIP receptors as molecular targets in NEN may be dependent on the MIB-1 level.

Expression of E-cadherin repressors SNAIL, ZEB1 and ZEB2 by tumour and stromal cells influences tumour-budding phenotype and suggests heterogeneity of stromal cells in pancreatic cancer.

BACKGROUND There is evidence that tumour-stroma interactions have a major role in the neoplastic progression of pancreatic ductal adenocarcinoma (PDAC). Tumour budding is thought to reflect the process of epithelial-mesenchymal transition (EMT); however, the relationship between tumour buds and EMT remains unclear. Here we characterize the tumour-budding- and stromal cells in PDAC at protein and mRNA levels concerning factors involved in EMT. METHODS mRNA in situ hybridisation and immunostaining for E-cadherin, β-catenin, SNAIL1, ZEB1, ZEB2, N-cadherin and TWIST1 were assessed in the main tumour, tumour buds and tumour stroma on multipunch tissue microarrays from 120 well-characterised PDACs and associated with the clinicopathological features, including peritumoural (PTB) and intratumoural (ITB) budding. RESULTS Tumour-budding cells showed increased levels of ZEB1 (P<0.0001) and ZEB2 (P=0.0119) and reduced E-cadherin and β-catenin (P<0.0001, each) compared with the main tumour. Loss of membranous β-catenin in the main tumour (P=0.0009) and tumour buds (P=0.0053), without nuclear translocation, as well as increased SNAIL1 in tumour and stromal cells (P=0.0002, each) correlated with high PTB. ZEB1 overexpression in the main tumour-budding and stromal cells was associated with high ITB (P=0.0084; 0.0250 and 0.0029, respectively) and high PTB (P=0.0005; 0.0392 and 0.0007, respectively). ZEB2 overexpression in stromal cells correlated with higher pT stage (P=0.03), lymphatic invasion (P=0.0172) and lymph node metastasis (P=0.0152). CONCLUSIONS In the tumour microenvironment of phenotypically aggressive PDAC, tumour-budding cells express EMT hallmarks at protein and mRNA levels underlining their EMT-type character and are surrounded by stromal cells expressing high levels of the E-cadherin repressors ZEB1, ZEB2 and SNAIL1, this being strongly associated with the tumour-budding phenotype. Moreover, our findings suggest the existence of subtypes of stromal cells in PDAC with phenotypical and functional heterogeneity.

Trends in incidence of oesophageal and gastric cancer according to morphology and anatomical location, in Switzerland 1982-2011.

QUESTION UNDER STUDY/PRINCIPLES This study aimed to evaluate trends in the incidence of oesophageal and gastric cancer by anatomical location and histology using nationally representative Swiss data. METHODS We included all oesophageal and gastric cancers recorded in 10 Swiss population-based cancer registries 1982-2011. We calculated age-standardised incidence rates (ASIRs) per 100 000 person-years (PY) (European standard) for both cancer sites stratified by sex, language region (German, French-Italian), morphology and anatomical location. To assess time trends, we estimated annual percentage changes (APCs) with 95% confidence intervals (95% CIs). RESULTS ASIR of oesophageal adenocarcinoma increased in both sexes and language regions (p <0.001). The steepest increase occurred in males of the German-speaking region (APC 6.8%, 95% CI 5.8-7.8) with ASIRs of 0.8 per 100,000 PY in 1982-1987 and 3.9 per 100.000 PY in 2007-2011. Incidence of oesophageal squamous cell carcinoma decreased significantly in males of both language regions by around -1.5% per year. In contrast, a slight but significant increase (APC 1.4%, 95% CI 0.3-2.4]) of oesophageal squamous cell carcinoma was observed in females of the German-speaking region. We observed stable rates for cancer of the gastric cardia. The incidence of noncardia gastric cancer decreased substantially in both sexes and language regions (p <0.001). CONCLUSION In Switzerland, the incidence of oesophageal adenocarcinoma has risen whereas incidence of noncardia gastric cancer has decreased substantially as observed in other developed countries.

Post mortem computed tomography and core needle biopsy in comparison to autopsy in eleven bernese mountain Dogs with histiocytic sarcoma

Background: Bernese mountain dogs are reported to have a shorter life expectancy than other breeds. A Major reason for this has been assigned to a high tumour prevalence, especially of histiocytic sarcoma. The efforts made by the breeding clubs to improve the longevity with the help of genetic tests and breeding value estimations are impeded by insufficiently reliable diagnoses regarding the cause of death. The current standard for post mortem examination in animals is performance of an autopsy. In human forensic medicine, imaging modalities, such as computed tomography and magnetic resonance imaging, are used with increasing frequency as a complement to autopsy. The present study investigates, whether post mortem computed tomography in combination with core needle biopsy is able to provide a definitive diagnosis of histiocytic sarcoma. For this purpose we have analysed the results of post mortem computed tomography and core needle biopsy in eleven Bernese mountain dogs. In the subsequent autopsy, every dog had a definitive diagnosis of histiocytic sarcoma, based on immunohistochemistry. Results: Computed tomography revealed space-occupying lesions in all dogs. Lesion detection by post mortem computed tomography was similar to lesion detection in autopsy for lung tissue (9 cases in computed tomography / 8 cases in autopsy), thoracic lymph nodes (9/8), spleen (6/7), kidney (2/2) and bone (3/3). Hepatic nodules, however, were difficult to detect with our scanning protocol (2/7). Histology of the core needle biopsies provided definitive diagnoses of histiocytic sarcoma in ten dogs, including confirmation by immunohistochemistry in six dogs. The biopsy samples of the remaining dog did not contain any identifiable neoplastic cells. Autolysis was the main reason for uncertain histological diagnoses. Conclusions: Post mortem computed tomography is a fast and effective method for the detection of lesions suspicious for histiocytic sarcoma in pulmonary, thoracic lymphatic, splenic, osseous and renal tissue. Optimization of the procedure regarding the scanning protocol and tissue sample size and number will improve the accuracy of the method. Keywords: Post mortem computed tomography, Core needle biopsy, Bernese mountain dog, Histiocytic sarcoma, Autopsy

Clinical Significance of NOTCH1 and NOTCH2 Expression in Gastric Carcinomas: An Immunohistochemical Study.

BACKGROUND NOTCH signaling can exert oncogenic or tumor suppressive functions and can contribute to chemotherapy resistance in cancer. In this study, we aimed to clarify the clinicopathological significance and the prognostic and predictive value of NOTCH1 and NOTCH2 expression in gastric cancer (GC). METHODS NOTCH1 and NOTCH2 expression was determined immunohistochemically in 142 primarily resected GCs using tissue microarrays and in 84 pretherapeutic biopsies from patients treated by neoadjuvant chemotherapy. The results were correlated with survival, response to therapy, and clinico-pathological features. RESULTS Primarily resected patients with NOTCH1-negative tumors demonstrated worse survival. High NOTCH1 expression was associated with early-stage tumors and with significantly increased survival in this subgroup. Higher NOTCH2 expression was associated with early-stage and intestinal-type tumors and with better survival in the subgroup of intestinal-type tumors. In pretherapeutic biopsies, higher NOTCH1 and NOTCH2 expression was more frequent in non-responding patients, but these differences were statistically not significant. CONCLUSION Our findings suggested that, in particular, NOTCH1 expression indicated good prognosis in GC. The close relationship of high NOTCH1 and NOTCH2 expression with early tumor stages may indicate a tumor-suppressive role of NOTCH signaling in GC. The role of NOTCH1 and NOTCH2 in neoadjuvantly treated GC is limited.

Osteogenic differentiation of bone marrow stromal cells is hindered by the presence of intervertebral disc cells.

BACKGROUND Clinical observations indicate that the presence of nucleus pulposus (NP) tissue during spinal fusion hinders the rate of disc ossification. While the underlying mechanism remains unknown, this observation could be due to incomplete removal of NP cells (NPCs) that secrete factors preventing disc calcification, such as bone morphogenetic protein (BMP) antagonists including noggin and members of the DAN (differential screening selected gene aberrative in neuroblastoma) family. METHODS Monolayer human bone marrow-derived mesenchymal stem cells (MSCs) were cocultured withNPCs and annulus fibrosus cells (AFCs) embedded in alginate for 21 days. At the end of coculture, MSCs were stained for mineral deposition by alizarin red, and relative expression of bone-related genes [Runt-related transcription factor 2, (RUNX2), Osteopontin (OPN), and Alkaline phosphatase (ALP)] and ALP activity were analyzed. Relative expression of three BMP antagonists, chordin (CHRD), gremlin (GREM1), and noggin (NOG), was determined in primary human NPCs and AFCs. These cells were also stained for Gremlin and Noggin by immunocytochemistry. RESULTS Alizarin red staining showed that MSC osteogenesis in monolayer cultures was inhibited by coculture with NPCs or AFCs. ALP activity and RT-PCR analyses confirmed these results and demonstrated inhibition of osteogenesis of MSC in the presence of disc cells. NOG was significantly up-regulated in MSCs after coculture. Relative gene expression of intervertebral disc (IVD) cells showed higher expression of GREM1 in NPCs than in AFCs. CONCLUSIONS We show that primary IVD cells inhibit osteogenesis of MSCs. BMP inhibitors NOG, GREM1 and CHRD were expressed in IVD cells. GREM1 appears to be differentially expressed in NPCs and AFCs. Our results have implications for the design and development of treatments for non-union in spinal fusion.