Prognostic implications of the seventh edition of the international union against cancer classification for patients with gastric cancer: the Western experience of patients treated in a single-center European institution

PURPOSE Validity of the seventh edition of the American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) staging systems for gastric cancer has been evaluated in several studies, mostly in Asian patient populations. Only few data are available on the prognostic implications of the new classification system on a Western population. Therefore, we investigated its prognostic ability based on a German patient cohort. PATIENTS AND METHODS Data from a single-center cohort of 1,767 consecutive patients surgically treated for gastric cancer were classified according to the seventh edition and were compared using the previous TNM/UICC classification. Kaplan-Meier analyses were performed for all TNM stages and UICC stages in a comparative manner. Additional survival receiver operating characteristic analyses and bootstrap-based goodness-of-fit comparisons via Bayesian information criterion (BIC) were performed to assess and compare prognostic performance of the competing classification systems. RESULTS We identified the UICC pT/pN stages according to the seventh edition of the AJCC/UICC guidelines as well as resection status, age, Lauren histotype, lymph-node ratio, and tumor grade as independent prognostic factors in gastric cancer, which is consistent with data from previous Asian studies. Overall survival rates according to the new edition were significantly different for each individual's pT, pN, and UICC stage. However, BIC analysis revealed that, owing to higher complexity, the new staging system might not significantly alter predictability for overall survival compared with the old system within the analyzed cohort from a statistical point of view. CONCLUSION The seventh edition of the AJCC/UICC classification was found to be valid with distinctive prognosis for each stage. However, the AJCC/UICC classification has become more complex without improving predictability for overall survival in a Western population. Therefore, simplification with better predictability of overall survival of patients with gastric cancer should be considered when revising the seventh edition.

Lesions of the gastric mucosa in adult horses of different disciplines: a review

The prevalence of gastric mucosal lesions in the thoroughbred race horse has been the subject of numerous studies. The frequency of gastric ulcer diseases in the adult horse of other sport disciplines are less well investigated. Recent data show that gastric mucosal lesions in non thoroughbred racehorses occur considerably more frequently than previously thought. Prevalences of up to 93 % in endurance horses, of up to 87 % in standardbreds, of 40 % in western horses, of 63 % in show-jumping horses, of 71 % in broodmares and of 53 % in leisure horses are reported. Since the introduction of gastroscopy in equine medicine in the 1990s, numerous scoring-systems to describe the number, the severity and the localisation of the lesions have been used. Unfortunately, no standardized scoring system is generally accepted to date. A direct comparison of results from different studies is therefore difficult. Comparison and interpretation of data is further hampered by the heterogenicity of the study populations which consist of horses of different age-groups, breeds and exercise intensity.

Gastric pharmacobezoars in quetiapine extended-release overdose: a case series

OBJECTIVE Although extended-release (XR) formulations are recognized to bear some risk of pharmacobezoar formation in overdose, there are no previously documented reports of this phenomenon with quetiapine. We describe nine cases of pharmacobezoar formation in acute quetiapine XR overdose. METHODS Observational case series of all patients who underwent gastroscopy after quetiapine XR overdose, which were reported by physicians to the Swiss Toxicological Information Centre between January 2010 and December 2012, with detailed analysis of cases with documented pharmacobezoar. RESULTS Gastric pharmacobezoars were detected in 9 out of 19 gastroscopic evaluations performed during the study period. All these patients ingested a large dose of quetiapine XR (10-61 tablets; 6-24.4 g quetiapine). All patients but one also coingested at least one other substance, and in three cases another XR drug formulation. Gastroscopic pharmacobezoar removal was achieved without complications in all patients, but was difficult due to the particular "gelatinous-sticky-pasty" consistency of the concretion. The subsequent clinical course was favorable. CONCLUSIONS The possibility of pharmacobezoar formation following a large quetiapine XR overdose should be considered, as this may influence acute patient management. Complete endoscopic pharmacobezoar removal may be a promising approach in selected cases, but further studies are needed to define its role.

ROLE OF GSH METABOLISM IN MEDIATING STROMAL-LEUKEMIA INTERACTION AND PROMOTING CELL SURVIVAL AND DRUG RESISTANCE IN CHRONIC LYMPHOCYTIC LEUKEMIA

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the western countries. The interaction between CLL cells and the bone marrow stromal environment is thought to play a major role in promoting the leukemia cell survival and drug resistance. My dissertation works proved a novel biochemical mechanism by which the bone marrow stromal cells exert a profound influence on the redox status of primary CLL cells and enhance their ability to sustain oxidative stress and drug treatment. Fresh leukemia cells isolated from the peripheral blood of CLL patients exhibited two major redox alterations when they were cultured alone: a significant decrease in cellular glutathione (GSH) and an increase in basal ROS levels. However, when cultured in the presence of bone marrow stromal cells, CLL cells restored their redox balance with an increased synthesis of GSH, a decrease in spontaneous apoptosis, and an improved cell survival. Further study showed that CLL cells were under intrinsic ROS stress and highly dependent on GSH for survival, and that the bone marrow stromal cells promoted GSH synthesis in CLL cells through a novel biochemical mechanism. Cysteine is a limiting substrate for GSH synthesis and is chemically unstable. Cells normally obtain cysteine by uptaking the more stable and abundant precursor cystine from the tissue environment and convert it to cysteine intracellularly. I showed that CLL cells had limited ability to take up extracellular cystine for GSH synthesis due to their low expression of the transporter Xc-, but had normal ability to uptake cysteine. In the co-culture system, the bone marrow stromal cells effectively took up cystine and reduced it to cysteine for secretion into the tissue microenvironment to be taken up by CLL cells for GSH synthesis. The elevated GSH in CLL cells in the presence of bone marrow stromal cells significantly protected the leukemia cells from stress-induced apoptosis, and rendered them resistant to standard therapeutic agents such as fludarabine and oxaliplatin. Importantly, disabling of this protective mechanism by depletion of cellular GSH using a pharmacological approach potently sensitized CLL cells to drug treatment, and effectively enhanced the cytotoxic action of fludarabine and oxaliplatin against CLL in the presence of stromal cells. This study reveals a key biochemical mechanism of leukemia-stromal cells interaction, and identifies a new therapeutic strategy to overcome drug resistance in vivo.

Activation of Src kinase Lyn by the Kaposi sarcoma-associated herpesvirus K1 protein: implications for lymphomagenesis.

The K1 gene of Kaposi sarcoma-associated herpesvirus (KSHV) encodes a transmembrane glycoprotein bearing a functional immunoreceptor tyrosine-based activation motif (ITAM). Previously, we reported that the K1 protein induced plasmablastic lymphomas in K1 transgenic mice, and that these lymphomas showed enhanced Lyn kinase activity. Here, we report that systemic administration of the nuclear factor kappa B (NF-kappaB) inhibitor Bay 11-7085 or an anti-vascular endothelial growth factor (VEGF) antibody significantly reduced K1 lymphoma growth in nude mice. Furthermore, in KVL-1 cells, a cell line derived from a K1 lymphoma, inhibition of Lyn kinase activity by the Src kinase inhibitor PP2 decreased VEGF induction, NF-kappaB activity, and the cell proliferation index by 50% to 75%. In contrast, human B-cell lymphoma BJAB cells expressing K1, but not the ITAM sequence-deleted mutant K1, showed a marked increase in Lyn kinase activity with concomitant VEGF induction and NF-kappaB activation, indicating that ITAM sequences were required for the Lyn kinase-mediated activation of these factors. Our results suggested that K1-mediated constitutive Lyn kinase activation in K1 lymphoma cells is crucial for the production of VEGF and NF-kappaB activation, both strongly implicated in the development of KSHV-induced lymphoproliferative disorders.

Direct intrathecal implantation of mesenchymal stromal cells leads to enhanced neuroprotection via an NFkappaB-mediated increase in interleukin-6 production.

Mesenchymal stromal cell (MSC) therapy has shown promise for the treatment of traumatic brain injury (TBI). Although the mechanism(s) by which MSCs offer protection is unclear, initial in vivo work has suggested that modulation of the locoregional inflammatory response could explain the observed benefit. We hypothesize that the direct implantation of MSCs into the injured brain activates resident neuronal stem cell (NSC) niches altering the intracerebral milieu. To test our hypothesis, we conducted initial in vivo studies, followed by a sequence of in vitro studies. In vivo: Sprague-Dawley rats received a controlled cortical impact (CCI) injury with implantation of 1 million MSCs 6 h after injury. Brain tissue supernatant was harvested for analysis of the proinflammatory cytokine profile. In vitro: NSCs were transfected with a firefly luciferase reporter for NFkappaB and placed in contact culture and transwell culture. Additionally, multiplex, quantitative PCR, caspase 3, and EDU assays were completed to evaluate NSC cytokine production, apoptosis, and proliferation, respectively. In vivo: Brain supernatant analysis showed an increase in the proinflammatory cytokines IL-1alpha, IL-1beta, and IL-6. In vitro: NSC NFkappaB activity increased only when in contact culture with MSCs. When in contact with MSCs, NSCs show an increase in IL-6 production as well as a decrease in apoptosis. Direct implantation of MSCs enhances neuroprotection via activation of resident NSC NFkappaB activity (independent of PI3 kinase/AKT pathway) leading to an increase in IL-6 production and decrease in apoptosis. In addition, the observed NFkappaB activity depends on direct cell contact.

A direct role for secretory phospholipase A2 and lysophosphatidylcholine in the mediation of LPS-induced gastric injury.

Endotoxemia from sepsis can injure the gastrointestinal tract through mechanisms that have not been fully elucidated. We have shown that LPS induces an increase in gastric permeability in parallel with the luminal appearance of secretory phospholipase A2 (sPLA2) and its product, lysophosphatidylcholine (lyso-PC). We proposed that sPLA2 acted on the gastric hydrophobic barrier, composed primarily of phosphatidylcholine (PC), to degrade it and produce lyso-PC, an agent that is damaging to the mucosa. In the present study, we have tested whether lyso-PC and/or sPLA2 have direct damaging effects on the hydrophobic barriers of synthetic and mucosal surfaces. Rats were administered LPS (5 mg/kg, i.p.), and gastric contents were collected 5 h later for analysis of sPLA2 and lyso-PC content. Using these measured concentrations, direct effects of sPLA2 and lyso-PC were determined on (a) surface hydrophobicity as detected with an artificial PC surface and with intact gastric mucosa (contact angle analysis) and (b) cell membrane disruption of gastric epithelial cells (AGS). Both lyso-PC and sPLA2 increased significantly in the collected gastric juice of LPS-treated rats. Using similar concentrations to the levels in gastric juice, the contact angle of PC-coated slides declined after incubation with either pancreatic sPLA2 or lyso-PC. Similarly, gastric contact angles seen in control rats were significantly decreased in sPLA2 and lyso-PC-treated rats. In addition, we observed dose-dependent injurious effects of both lyso-PC and sPLA2 in gastric AGS cells. An LPS-induced increase in sPLA2 activity in the gastric lumen and its product, lyso-PC, are capable of directly disrupting the gastric hydrophobic layer and may contribute to gastric barrier disruption and subsequent inflammation.

Naive B-cell trafficking is shaped by local chemokine availability and LFA-1-independent stromal interactions.

It is not known how naive B cells compute divergent chemoattractant signals of the T-cell area and B-cell follicles during in vivo migration. Here, we used two-photon microscopy of peripheral lymph nodes (PLNs) to analyze the prototype G-protein-coupled receptors (GPCRs) CXCR4, CXCR5, and CCR7 during B-cell migration, as well as the integrin LFA-1 for stromal guidance. CXCR4 and CCR7 did not influence parenchymal B-cell motility and distribution, despite their role during B-cell arrest in venules. In contrast, CXCR5 played a nonredundant role in B-cell motility in follicles and in the T-cell area. B-cell migration in the T-cell area followed a random guided walk model, arguing against directed migration in vivo. LFA-1, but not α4 integrins, contributed to B-cell motility in PLNs. However, stromal network guidance was LFA-1 independent, uncoupling integrin-dependent migration from stromal attachment. Finally, we observed that despite a 20-fold reduction of chemokine expression in virus-challenged PLNs, CXCR5 remained essential for B-cell screening of antigen-presenting cells. Our data provide an overview of the contribution of prototype GPCRs and integrins during naive B-cell migration and shed light on the local chemokine availability that these cells compute.

Cryo-electron tomography of Kaposi's sarcoma-associated herpesvirus capsids reveals dynamic scaffolding structures essential to capsid assembly and maturation.

Kaposi's sarcoma-associated herpesvirus (KSHV) is a recently discovered DNA tumor virus that belongs to the gamma-herpesvirus subfamily. Though numerous studies on KSHV and other herpesviruses, in general, have revealed much about their multilayered organization and capsid structure, the herpesvirus capsid assembly and maturation pathway remains poorly understood. Structural variability or irregularity of the capsid internal scaffolding core and the lack of adequate tools to study such structures have presented major hurdles to earlier investigations employing more traditional cryo-electron microscopy (cryoEM) single particle reconstruction. In this study, we used cryo-electron tomography (cryoET) to obtain 3D reconstructions of individual KSHV capsids, allowing direct visualization of the capsid internal structures and systematic comparison of the scaffolding cores for the first time. We show that B-capsids are not a structurally homogenous group; rather, they represent an ensemble of "B-capsid-like" particles whose inner scaffolding is highly variable, possibly representing different intermediates existing during the KSHV capsid assembly and maturation. This information, taken together with previous observations, has allowed us to propose a detailed pathway of herpesvirus capsid assembly and maturation.