175 research outputs found

    Localization of Helicobacter spp. in the fundic mucosa of laboratory Beagle dogs: an ultrastructural study

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    In dogs Helicobacter spp. are found in all gastric regions usually localized in the surface mucus, gastric glands and parietal cells. The aim of this study was to detail the distribution of Helicobacter spp. in the fundic mucosa of asymptomatic Beagle dogs and their intracellular localization within parietal cells, in order to evaluate species-specific pathogenetic effects on gastric cells. The presence of Helicobacter spp. was investigated by immunohistochemistry, TEM, and PCR in the fundic mucosa of six Beagle dogs. Helicobacter spp. were found in all dogs examined, and H. bizzozeronii and H. felis were identified by PCR and confirmed by TEM. In the lumen of the fundic glands, co-localization was common. H. bizzozeronii was present in larger numbers than H. felis in both intraluminal and intraparietal localization. The amounts of H. bizzozeronii were similar in superficial and basal portions of the glands. H. felis was predominantly localized in the superficial portions of gastric glands but almost absent from the base. Within parietal cells, most Helicobacter organisms were intracanalicular, but intact and degenerate Helicobacter organisms were also visualized free in the cytoplasm or in secondary lysosomes. No specific degenerative lesions were found in infected parietal cells. Helicobacter organisms were also observed within macrophages in the lamina propria. In conclusion, there is a differential distribution of H. bizzozeronii and H. felis in the fundic mucosa of Beagle dogs, and their intracellular localization in parietal cells and macrophages suggests novel pathogenic scenarios for the development of immune response and maintenance of chronic gastritis in dogs

    Differential responsiveness to constitutive vs. inducible chemokines of immature and mature mouse dendritic cells

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    Upon exposure to immune or inflammatory stimuli, dendritic cells (DC) migrate from peripheral tissues to lymphoid organs, where they present antigen. The molecular basis for the peculiar trafficking properties of DC is largely unknown. In this study, mouse DC were generated from CD34+ bone marrow precursors and cultured with granulocyte-macrophage-CSF and Flt3 ligand for 9 days. Chemokines active on immature DC include MIP1alpha, RANTES, MIP1beta, MCP-1, MCP-3, and the constitutively expressed SDF1, MDC, and ELC. TNF-alpha-induced DC maturation caused reduction of migration to inducible chemokines (MIP1alpha, RANTES, MIP1beta, MCP-1, and MCP-3) and increased migration to SDF1, MDC, and ELC. Similar results were obtained by CD40 ligation or culture in the presence of bacterial lipopolysaccharide. TNF-alpha down-regulated CC chemokine receptor (CCR)1, CCR2, and CCR5 and up-regulated CCR7 mRNA levels, in agreement with functional data. This study shows that selective responsiveness of mature and immature DC to inducible vs. constitutively produced chemokines can contribute to the regulated trafficking of DC

    Factors that predict early treatment failure for patients with locally advanced (T4) breast cancer

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    Locally advanced breast cancer (LABC) is associated with dire prognosis despite progress in multimodal treatments. We evaluated several clinical and pathological features of patients with either noninflammatory (NIBC, cT4a-c) or inflammatory (IBC, cT4d) breast cancer to identify subset groups of patients with high risk of early treatment failure. Clinical and pathological features of 248 patients with LABC, who were treated with multimodality treatments including neoadjuvant chemotherapy followed by radical surgery and radiotherapy were reassessed. Tumour samples obtained at surgery were evaluated using standard immunohistochemical methods. Overall, 141 patients (57%) presented with NIBC (cT4a-c, N0-2, M0) and 107 patients (43%) with IBC (cT4d, N0-2, M0). Median follow-up time was 27.5 months (range: 1.6–87.8). No significant difference in terms of recurrence-free survival (RFS) (P=0.72), disease-free survival (DFS) (P=0.98) and overall survival (OS) (P=0.35) was observed between NIBC and IBC. At the multivariate analysis, patients with ER- and PgR-negative diseases had a significantly worse RFS than patients with ER- and/or PgR-positive diseases (hazard ratio: 2.47, 95% CI: 1.33–4.59 for overall). The worst RFS was observed for the subgroup of patients with endocrine nonresponsive and HER2-negative breast cancer (2-year RFS: 57% in NIBC and 57% in IBC) A high Ki-67 labelling index (>20% of the invasive tumour cells) and the presence of peritumoral vascular invasion (PVI) significantly correlated with poorer RFS in overall (HR 2.69, 95% CI: 1.61–4.50 for Ki-67>20% and HR 2.27, 95% CI: 1.42–3.62 for PVI). Patients with endocrine nonresponsive LABC had the most dire treatment outcome. High degree of Ki-67 staining and presence of PVI were also indicators of higher risk of early relapse. These factors should be considered in therapeutic algorithms for LABC

    Model of SNARE-Mediated Membrane Adhesion Kinetics

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    SNARE proteins are conserved components of the core fusion machinery driving diverse membrane adhesion and fusion processes in the cell. In many cases micron-sized membranes adhere over large areas before fusion. Reconstituted in vitro assays have helped isolate SNARE mechanisms in small membrane adhesion-fusion and are emerging as powerful tools to study large membrane systems by use of giant unilamellar vesicles (GUVs). Here we model SNARE-mediated adhesion kinetics in SNARE-reconstituted GUV-GUV or GUV-supported bilayer experiments. Adhesion involves many SNAREs whose complexation pulls apposing membranes into contact. The contact region is a tightly bound rapidly expanding patch whose growth velocity increases with SNARE density . We find three patch expansion regimes: slow, intermediate, fast. Typical experiments belong to the fast regime where depends on SNARE diffusivities and complexation binding constant. The model predicts growth velocities s. The patch may provide a close contact region where SNAREs can trigger fusion. Extending the model to a simple description of fusion, a broad distribution of fusion times is predicted. Increasing SNARE density accelerates fusion by boosting the patch growth velocity, thereby providing more complexes to participate in fusion. This quantifies the notion of SNAREs as dual adhesion-fusion agents

    What's in a Sign? Trademark Law and Economic Theory

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    Abstract: The aim of this paper is to summarise the extant theory as it relates to the economics of trademark, and to give some suggestions for further research with reference to distinct streams of literature. The proposed line of study inevitably looks at the complex relationship between signs and economics. Trademark is a sign introduced to remedy a market failure. It facilitates purchase decisions by indicating the provenance of the goods, so that consumers can identify specific quality attributes deriving from their own, or others', past experience. Trademark holders, on their part, have an incentive to invest in quality because they will be able to reap the benefits in terms of reputation. In other words, trademark law becomes an economic device which, opportunely designed, can produce incentives for maximising market efficiency. This role must, of course, be recognised, as a vast body of literature has done, with its many positive economic consequences. Nevertheless, trademark appears to have additional economic effects that should be properly recognized: it can determine the promotion of market power and the emergence of rent-seeking behaviours. It gives birth to an idiosyncratic economics of signs where very strong protection tends to be assured, even though the welfare effects are as yet poorly understood. In this domain much remains to be done and the challenge to researchers is open

    Obtaining Adequate Surgical Margins in Breast-Conserving Therapy for Patients with Early-Stage Breast Cancer: Current Modalities and Future Directions

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    Inadequate surgical margins represent a high risk for adverse clinical outcome in breast-conserving therapy (BCT) for early-stage breast cancer. The majority of studies report positive resection margins in 20% to 40% of the patients who underwent BCT. This may result in an increased local recurrence (LR) rate or additional surgery and, consequently, adverse affects on cosmesis, psychological distress, and health costs. In the literature, various risk factors are reported to be associated with positive margin status after lumpectomy, which may allow the surgeon to distinguish those patients with a higher a priori risk for re-excision. However, most risk factors are related to tumor biology and patient characteristics, which cannot be modified as such. Therefore, efforts to reduce the number of positive margins should focus on optimizing the surgical procedure itself, because the surgeon lacks real-time intraoperative information on the presence of positive resection margins during breast-conserving surgery. This review presents the status of pre- and intraoperative modalities currently used in BCT. Furthermore, innovative intraoperative approaches, such as positron emission tomography, radioguided occult lesion localization, and near-infrared fluorescence optical imaging, are addressed, which have to prove their potential value in improving surgical outcome and reducing the need for re-excision in BCT
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