507 research outputs found

    On the association between Haplosyllis (Polychaeta, Syllidae) and gorgonians (Cnidaria, Octocorallaria), with the description of a new species

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    23 páginas, 13 figuras, 2 tablas.The present paper includes a morphological, ecological and biological updating of the three gorgonian associated species of Haplosyllis (Polychaeta, Syllidae) known to date: H. chamaeleon (symbiont with Paramuricea clavata in the Mediterranean), H. anthogorgicola (symbiont with Anthogorgia bocki in the Japanese seas) and H. villogorgicola , a new species living symbiotically with Villogorgia bebrycoides which is only known from Tenerife (Canary Islands, Eastern Central Atlantic). The new species is described on the basis of ecological, morphological, morphometric and statistical analysis of relevant characteristics. Each host colony harboured about 15 pale-yellowish worms, whose cryptic colouration mimicked that of the host. They occurred either on the host branches or partly hidden inside cavities formed by the fusion of two branches. The new species is characterized by the presence of simple chaetae with clearly bidentate tips all along the body, the presence of gland pore aggregates distributed in two lateral rows and two ventral patches on each palp and the absence of ciliary tufts on the pharyngeal papillae. H. villogorgicola sp. nov. is closely related to H. chamaeleon . Thus, it is compared with two populations of this species collected in the north-west and south-west Mediterranean. Stolons of H. chamaeleon are re-described as tetracerous and a peculiar posterior end regeneration process occurring in adult worms during the stolon formation is described. H. anthogorgicola is also re-described, with particular emphasis on its appendage and chaetal arrangements. The main features of the three associations are discussed in light of the current knowledge on symbiotic polychaetes, particularly cnidarian-associated syllids. © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 2002, 77 , 455–477.This paper is a contribution to the research project INTAS-97–0916.Peer reviewe

    Antibiotic prescribing for endodontic infections: a survey of dental students in Italy

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    Aim To determine the knowledge of final year undergraduate students attending Italian universities on the appropriate use of systemic antibiotics for endodontic infections. Methodology Final year dental students from twenty Italian universities completed a one-page questionnaire on antibiotic use for the treatment of endodontic infections. Data were analysed using descriptive statistics and chi-square tests. Results A total of three hundred and three students completed the questionnaire. The average duration of antibiotic prescription proposed by respondents was 5.48 1.06 days. Amoxicillin with clavulanic acid was the first-choice antibiotic (85.2%) followed by amoxicillin alone (13.5%), azithromycin (1.0%) and clarithromycin (0.3%), for patients not allergic to penicillin. Clarithromycin was the first-choice drug for patients with a penicillin allergy (56.1%), followed from azithromycin (31.7%), clindamycin (11.9%) and levofloxacin (0.3%). Alveolar abscess with systemic manifestations was reported as the principal reason to prescribe antibiotics (97.7%) followed by the same condition without systemic manifestations (85.5%). For the scenario of irreversible pulpitis, 5% of students considered antibiotics necessary. Almost 52% of students would prescribe antibiotics for apical acute periodontitis; 29.7% would prescribe antibiotics for chronic apical periodontitis with sinus tract, and 13.5% indicated these drugs for chronic apical periodontitis without sinus tract. Conclusions The results demonstrate that it is necessary to improve the knowledge of Italian students on antibiotics and indications for their use in endodontics

    Increased Seroreactivity to Glioma-Expressed Antigen 2 in Brain Tumor Patients under Radiation

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    Background: Surgery and radiation are the mainstays of therapy for human gliomas that are the most common primary brain tumors. Most recently, cell culture and animal studies provided the first convincing evidence that radiation not only eliminates tumor cells, but also modulates the immune response and likely improves anti-tumor immunotherapy. Methology/Pricipal Findings: We present an in vivo study that analyzes the effects of radiation on the immune response in tumor patients. As readout system, we utilized the reactivity of glioma patients ’ sera against antigen GLEA2 as the most frequent antigen immunogenic in glioblastoma patients. We established an ELISA assay to analyze reactivity of 24 glioblastoma patients over a period of several months. As control we used 30 sera from healthy donors as well as 30 sera from lung cancer patients. We compared the course of GLEA2 seroreactivity at different times prior, during and after radiation. The GLEA2 seroreactivity was increased by the time of surgery, decreased after surgery, increased again under radiation, and slightly decreased after radiation. Conclusions/Significance: Our results provide in vivo evidence for an increased antibody response against tumor antigens under radiation. Antigens that become immunogenic with an increased antibody response as result of radiation can serv

    Chronic lymphocytic leukaemia: the role of T cells in a B cell disease

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    Chronic lymphocytic leukaemia (CLL) has long been thought to be an immunosuppressive disease and abnormalities in T‐cell subset distribution and function have been observed in many studies. However, the role of T cells (if any) in disease progression remains unclear and has not been directly studied. This has changed with the advent of new therapies, such as chimeric antigen receptor‐T cells, which actively use retargeted patient‐derived T cells as “living drugs” for CLL. However complete responses are relatively low (~26%) and recent studies have suggested the differentiation status of patient T cells before therapy may influence efficacy. Non‐chemotherapeutic drugs, such as idelalisib and ibrutinib, also have an impact on T cell populations in CLL patients. This review will highlight what is known about T cells in CLL during disease progression and after treatment, and discuss the prospects of using T cells as predictive biomarkers for immune status and response to therapy

    Sensitizing Protective Tumor Microenvironments to Antibody-Mediated Therapy

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    Therapy-resistant microenvironments represent a major barrier toward effective elimination of disseminated malignancies. Here, we show that select microenvironments can underlie resistance to antibody-based therapy. Using a humanized model of treatment refractory B cell leukemia, we find that infiltration of leukemia cells into the bone marrow rewires the tumor microenvironment to inhibit engulfment of antibody-targeted tumor cells. Resistance to macrophage-mediated killing can be overcome by combination regimens involving therapeutic antibodies and chemotherapy. Specifically, the nitrogen mustard cyclophosphamide induces an acute secretory activating phenotype (ASAP), releasing CCL4, IL8, VEGF, and TNFα from treated tumor cells. These factors induce macrophage infiltration and phagocytic activity in the bone marrow. Thus, the acute induction of stress-related cytokines can effectively target cancer cells for removal by the innate immune system. This synergistic chemoimmunotherapeutic regimen represents a potent strategy for using conventional anticancer agents to alter the tumor microenvironment and promote the efficacy of targeted therapeutics.Massachusetts Institute of Technology. Ludwig Center for Molecular OncologyKathy and Curt Marble Cancer Research FundSingapore-MIT Alliance for Research and TechnologyGerman Research Foundation (KFO286)German Research Foundation (Fellowship)National Cancer Institute (U.S.) (Koch Institute Support (Core) Grant P30-CA14051

    Rapid generation of human B-cell lymphomas via combined expression of Myc and Bcl2 and their use as a preclinical model for biological therapies

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    Although numerous mouse models of B-cell malignancy have been developed via the enforced expression of defined oncogenic lesions, the feasibility of generating lineage-defined human B-cell malignancies using mice reconstituted with modified human hematopoietic stem cells (HSCs) remains unclear. In fact, whether human cells can be transformed as readily as murine cells by simple oncogene combinations is a subject of considerable debate. Here, we describe the development of humanized mouse model of MYC/BCL2-driven ‘double-hit’ lymphoma. By engrafting human HSCs transduced with the oncogene combination into immunodeficient mice, we generate a fatal B malignancy with complete penetrance. This humanized-MYC/BCL2-model (hMB) accurately recapitulates the histopathological and clinical aspects of steroid-, chemotherapy- and rituximab-resistant human ‘double-hit’ lymphomas that involve the MYC and BCL2 loci. Notably, this model can serve as a platform for the evaluation of antibody-based therapeutics. As a proof of principle, we used this model to show that the anti-CD52 antibody alemtuzumab effectively eliminates lymphoma cells from the spleen, liver and peripheral blood, but not from the brain. The hMB humanized mouse model underscores the synergy of MYC and BCL2 in ‘double-hit’ lymphomas in human patients. Additionally, our findings highlight the utility of humanized mouse models in interrogating therapeutic approaches, particularly human-specific monoclonal antibodies.Kathy and Curt Marble Cancer Research FundSingapore-MIT Alliance for Research and TechnologyNational Institutes of Health (U.S.) (Grant R01-CA128803)Virginia and Daniel K. Ludwig Graduate FellowshipNational Institute of General Medical Sciences (U.S.) (Medical Scientist Training Program Grant T32GM007753)MIT School of Science (Cancer Research Fellowship
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