982 resultados para stromal abscess
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The formation of a 'tumor-associated vasculature', a process referred to as tumor angiogenesis, is a stromal reaction essential for tumor progression. Inhibition of tumor angiogenesis suppresses tumor growth in many experimental models, thereby indicating that tumor-associated vasculature may be a relevant target to inhibit tumor progression. Among the antiangiogenic molecules reported to date many are peptides and proteins. They include cytokines, chemokines, antibodies to vascular growth factors and growth factor receptors, soluble receptors, fragments derived from extracellular matrix proteins and small synthetic peptides. The polypeptide tumor necrosis factor (TNF, Beromun) was the first drug registered for the regional treatment of human cancer, whose mechanisms of action involved selective disruption of the tumor vasculature. More recently, bevacizumab (Avastin), an antibody against vascular endothelial growth factor (VEGF)-A, was approved as the first systemic antiangiogenic drug that had a significant impact on the survival of patients with advanced colorectal cancer, in combination with chemotherapy. Several additional peptides and antibodies with antiangiogenic activity are currently tested in clinical trials for their therapeutic efficacy. Thus, peptides, polypeptides and antibodies are emerging as leading molecules among the plethora of compounds with antiangiogenic activity. In this article, we will review some of these molecules and discuss their mechanism of action and their potential therapeutic use as anticancer agents in humans.
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This article describes the long-lasting psychological after-effects of a traumatic experience. There is growing lmowledge of the biomedical underpinnings of these phenomena: the underlying mechanisms belong to an implicit learning process whereby the victim remains under the influence of painful past experiences. One of these mechanisms concerns the development of a traumatic bonding which Iioticeably impedes the establishment of interpersona! relationships. The other mechanism, called "contextualisation deficit", is the difficulty of adjusting a person's emotional and behavioural reactivity to the context of present day !ife. This capacity of a traumatic experience to become incrusted long-termina human being's mind, and to haunt the victim with various forms of psychological and physical suffering, can be compared with the presence of a tumour or an abscess in somatic medicine. Th us, severe drug addiction can be conceptualised as a disorder in which the patient tries - in most cases ineffectively - to soothe the pain of today's world in cmmection with the trauma of the past. In conclusion, this article urges the development of psychiatrie care programmes which operate at the centre of the suffering encountered by the se patients, as a complement to the already well-established offers such as harm reduction, substitution therapy and social support.
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Petrositis is a rare and severe complication of acute otitis media and mastoiditis. Although the extension of the inflammatory process from the petrous apex to the adjacent Meckel cave can lead to trigeminal pain, an irritation of the trigeminal nerve roots resulting in acute or chronic hyperactivity of masticatory muscles has never been reported. We report here the unusual case of an 86-year-old man who presented with a handicapping myofascial pain and dysfunction syndrome of the right temporal muscle as a heralding manifestation of an unusual form of petrositis. The patient progressively developed a retropharyngeal abscess, a right sphenoid sinusitis, and fatal meningitis. This case demonstrated that (1) myofascial pain and dysfunction syndrome that does not respond to conventional treatments may suggest an unusual etiology and warrant further medical investigations and a detailed medical history and that (2) petrositis can manifest itself with atypical clinical symptoms and radiologic signs. (Quintessence Int 2011;42:419-422).
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OBJECTIVES: To evaluate the influence of genetic polymorphisms on the susceptibility to Candida colonization and intra-abdominal candidiasis, a blood culture-negative life-threatening infection in high-risk surgical ICU patients. DESIGN: Prospective observational cohort study. SETTING: Surgical ICUs from two University hospitals of the Fungal Infection Network of Switzerland. PATIENTS: Eighty-nine patients at high risk for intra-abdominal candidiasis (68 with recurrent gastrointestinal perforation and 21 with acute necrotizing pancreatitis). MEASUREMENTS AND MAIN RESULTS: Eighteen single-nucleotide polymorphisms in 16 genes previously associated with development of fungal infections were analyzed from patient's DNA by using an Illumina Veracode genotyping platform. Candida colonization was defined by recovery of Candida species from at least one nonsterile site by twice weekly monitoring of cultures from oropharynx, stools, urine, skin, and/or respiratory tract. A corrected colonization index greater than or equal to 0.4 defined "heavy" colonization. Intra-abdominal candidiasis was defined by the presence of clinical symptoms and signs of peritonitis or intra-abdominal abscess and isolation of Candida species either in pure or mixed culture from intraoperatively collected abdominal samples. Single-nucleotide polymorphisms in three innate immune genes were associated with development of a Candida corrected colonization index greater than or equal to 0.4 (Toll-like receptor rs4986790, hazard ratio = 3.39; 95% CI, 1.45-7.93; p = 0.005) or occurrence of intra-abdominal candidiasis (tumor necrosis factor-α rs1800629, hazard ratio = 4.31; 95% CI, 1.85-10.1; p= 0.0007; β-defensin 1 rs1800972, hazard ratio = 3.21; 95% CI, 1.36-7.59; p = 0.008). CONCLUSION: We report a strong association between the promoter rs1800629 single-nucleotide polymorphism in tumor necrosis factor-α and an increased susceptibility to intra-abdominal candidiasis in a homogenous prospective cohort of high-risk surgical ICU patients. This finding highlights the relevance of the tumor necrosis factor-α functional polymorphism in immune response to fungal pathogens. Immunogenetic profiling in patients at clinical high risk followed by targeted antifungal interventions may improve the prevention or preemptive management of this life-threatening infection.
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The anaerobic Gram-positive bacterium Propionibacterium avidum is a common inhabitant of the skin with low pathogenicity. We report a case of P. avidum sacroilitis, psoas abscess and osteomyelitis in a 67-year-old male who had recently undergone surgical repair of an inguinal hernia. The organism was recovered from blood cultures, a bone biopsy specimen and specimens from the abscess. The spectrum of bone and joint infections caused by Propionibacterium is discussed. Infection by Propionibacterium spp. should be considered in patients with bone and joint infections.
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Loss-of-function mutations in human profilaggrin gene have been identified as the cause of ichthyosis vulgaris (IV), and as a major predisposition factor for atopic dermatitis (AD). Similarly, flaky tail (a/a ma ft/ma ft/J) mice were described as a model for IV, and shown to be predisposed to eczema. The aim of this study was to correlate the flaky tail mouse phenotype with human IV and AD, in order to dissect early molecular events leading to atopic dermatitis in mice and men, suffering from filaggrin deficiency. Thus, 5-days old flaky tail pups were analyzed histologically, expression of cytokines was measured in skin and signaling pathways were investigated by protein analysis. Human biopsies of IV and AD patients were analyzed histologically and by real time PCR assays. Our data show acanthosis and hyperproliferation in flaky tail epidermis, associated with increased IL1β and thymic stromal lymphopoietin (TSLP) expression, and Th2-polarization. Consequently, NFκB and Stat pathways were activated, and IL6 mRNA levels were increased. Further, quantitative analysis of late epidermal differentiation markers revealed increased Small proline-rich protein 2A (Sprr2a) synthesis. Th2-polarization and Sprr2a increase may result from high TSLP expression, as shown after analysis of 5-days old K14-TSLP tg mouse skin biopsies. Our findings in the flaky tail mouse correlate with data obtained from patient biopsies of AD, but not IV. We propose that proinflammatory cytokines are responsible for acanthosis in flaky tail epidermis, and together with the Th2-derived cytokines lead to morphological changes. Accordingly, the a/a ma ft/ma ft/J mouse model can be used as an appropriate model to study early AD onset associated with profilaggrin deficiency.
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The precise mechanisms underlying the interaction between intestinal bacteria and the host epithelium lead to multiple consequences that remain poorly understood at the molecular level. Deciphering such events can provide valuable information as to the mode of action of commensal and probiotic microorganisms in the gastrointestinal environment. Potential roles of such microorganisms along the privileged target represented by the mucosal immune system include maturation prior, during and after weaning, and the reduction of inflammatory reactions in pathogenic conditions. Using human intestinal epithelial Caco-2 cell grown as polarized monolayers, we found that association of a Lactobacillus or a Bifidobacterium with nonspecific secretory IgA (SIgA) enhanced probiotic adhesion by a factor of 3.4-fold or more. Bacteria alone or in complex with SIgA reinforced transepithelial electrical resistance, a phenomenon coupled with increased phosphorylation of tight junction proteins zonula occludens-1 and occludin. In contrast, association with SIgA resulted in both enhanced level of nuclear translocation of NF-κB and production of epithelial polymeric Ig receptor as compared with bacteria alone. Moreover, thymic stromal lymphopoietin production was increased upon exposure to bacteria and further enhanced with SIgA-based complexes, whereas the level of pro-inflammatory epithelial cell mediators remained unaffected. Interestingly, SIgA-mediated potentiation of the Caco-2 cell responsiveness to the two probiotics tested involved Fab-independent interaction with the bacteria. These findings add to the multiple functions of SIgA and underscore a novel role of the antibody in interaction with intestinal bacteria.
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Expression of laminin-5 alpha3, beta3 and gamma2 protein subunits was investigated in colorectal adenocarcinomas using immunostaining and confocal microscopy. The laminin-5 heterotrimer was found in basement membranes and as extracellular deposits in tumor stroma. In contrast to the alpha3 subunit, which was under-expressed, the gamma2 and beta3 subunits were detected in the cytoplasm of carcinoma cells dissociating (budding) from neoplastic tubules, suggestive of focal alterations in laminin-5 assembly and secretion. Laminin-5 gamma2 or beta3 subunit-reactive budding carcinoma cells expressed cytokeratins but not vimentin; they did not proliferate and were not apoptotic. Furthermore, expression of laminin-5 gamma2 and beta3 subunits in budding cells was associated with focal under-expression of the E-cadherin-beta-catenin complex. Results from xenograft experiments showed that budding activity in colorectal adenocarcinomas could be suppressed when these tumors grew at ectopic s.c. sites in nude mice. In vitro, cultured colon carcinoma cells, but not adenoma-derived tumor cells, shared the laminin-5 phenotype expressed by carcinoma cells in vivo. Using colon carcinoma cell lines implanted orthotopically and invading the cecum of nude mice, the laminin-5-associated budding was restored, indicating that this phenotype is not only determined by tumor cell properties but also dependent on the tissue micro-environment. Our results indicate that both laminin-5 alpha3 subunit expression and cell-cell cohesiveness are altered in budding carcinoma cells, which we consider to be actively invading. We propose that the local tissue micro-environment contributes to these events.
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Background: Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors usually caused by mutations in the KIT or PDGFRA gene. Advanced disease generally cannot be cured by surgery nor by tyrosine kinase inhibitors (TKI), but TKIs have considerably improved outcome for patients (pts) with advanced GIST. Patients failing TKI treatment with imatinib (IM), sunitinib (SU) or nilotinib (NI) have a poor prognosis. Sorafenib is a multi kinase inhibitor that blocks not only receptor tyrosine kinases such as KIT, VEGFR and PDGFR but also serine/threonine kinases along the RAS/RAF/MEK/ERK pathway. Recently, clinical activity of sorafenib in third-line treatment in patients with GIST after IM and SU failure has been shown (Wiebe et al. ASCO 2008, #10502). Methods: We report herein preliminary data of 32 pts treated with sorafenib in nine European centers. Centers were selected based on their previous and known experience in GIST and reported all pts treated. Pts received sorafenib after failure of IM, SU and NI in fourth-line treatment. Baseline characteristics and treatment details have been retrieved via questionary. Results: Median age at sorafenib treatment start was 62 years (range 33-81 y), and the majority of pts were male (63 %). Primary tumor site was gastric or small intestine in 25% and 41% of pts, respectively. All pts had failed IM, SU, NI. 19 % of pts achieved partial remission and 44% disease stabilization. Approximately half of the pts had an improvement of symptoms and/or performance. Half of the pts were on treatment longer than 4 months (actuarial data) and 41% of pts continue to receive sorafenib. Median progression-free survival is 20 weeks and median overall survival 42 weeks (Kaplan-Meier), at a median follow-up of 22 weeks (range 3-54). Conclusions: This is the largest series assessing efficacy of sorafenib fourth-line treatment for IM, SU and NI refractory GIST reported yet. Sorafenib displays significant clinical activity in this heavily pretreated group of patients.
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The stromal scaffold of the lymph node (LN) paracortex is built by fibroblastic reticular cells (FRCs). Conditional ablation of lymphotoxin-β receptor (LTβR) expression in LN FRCs and their mesenchymal progenitors in developing LNs revealed that LTβR-signaling in these cells was not essential for the formation of LNs. Although T cell zone reticular cells had lost podoplanin expression, they still formed a functional conduit system and showed enhanced expression of myofibroblastic markers. However, essential immune functions of FRCs, including homeostatic chemokine and interleukin-7 expression, were impaired. These changes in T cell zone reticular cell function were associated with increased susceptibility to viral infection. Thus, myofibroblasic FRC precursors are able to generate the basic T cell zone infrastructure, whereas LTβR-dependent maturation of FRCs guarantees full immunocompetence and hence optimal LN function during infection.
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Background: Inflammasome activation with the production of IL-1 beta received substantial attention recently in inflammatory diseases. However, the role of inflammasome in the pathogenesis of asthma is not clear. Using an adjuvant-free model of allergic lung inflammation induced by ovalbumin (OVA), we investigated the role of NLRP3 inflammasome and related it to IL-1R1 signaling pathway.Methods: Allergic lung inflammation induced by OVA was evaluated in vivo in mice deficient in NLRP3 inflammasome, IL-1R1, IL-1 beta or IL-1 alpha. Eosinophil recruitment, Th2 cytokine, and chemokine levels were determined in bronchoalveolar lavage fluid, lung homogenates, and mediastinal lymph node cells ex vivo.Results: Allergic airway inflammation depends on NLRP3 inflammasome activation. Dendritic cell recruitment into lymph nodes, Th2 lymphocyte activation in the lung and secretion of Th2 cytokines and chemokines are reduced in the absence of NLRP3. Absence of NLRP3 and IL-1 beta is associated with reduced expression of other proinflammatory cytokines such as IL-5, IL-13, IL-33, and thymic stromal lymphopoietin. Furthermore, the critical role of IL-1R1 signaling in allergic inflammation is confirmed in IL-1R1-, IL-1 beta-, and IL-1 alpha-deficient mice.Conclusion: NLRP3 inflammasome activation leading to IL-1 production is critical for the induction of a Th2 inflammatory allergic response.
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BACKGROUND: Until recently, it was accepted that the rate of complications and failure of medical therapy were higher during recurrent episodes of diverticulitis. New data and new interpretation of older studies have challenged this opinion. The aim of the present study was to determine whether recurrent diverticulitis in comparison with the initial episode has a different short-term outcome after medical or surgical treatment. METHODS: This was a retrospective cohort study of 271 consecutive patients admitted for diverticulitis confirmed by computed tomography (CT) between 2001 and 2004. Altogether 202 patients had an initial episode (group I), and 69 had recurrent diverticulitis (group R). A total of 20 clinical and 15 radiologic parameters were analyzed and compared between the two groups, including need for surgery, clinical presentation at admission, response to treatment, complications, laboratory parameters, and pathologic CT features (colonic wall thickening, abscess, pneumoperitoneum, free intraperitoneal fluid). An unpaired Student's t-test and Fisher's and Wilcoxon's tests were applied for statistical analysis. RESULTS: None of the clinical or radiologic parameters was statistically different between the two groups. Regarding surgery, 15.8% of the group I patients needed surgery at admission compared to 5.8% in group R (p = 0.04). Conservative treatment failure was similar in the two groups (10.7% vs. 10.0%; p = 0.84). There was 3% mortality at 30 days in group I compared to 0% in group R. CONCLUSIONS: Recurrent episodes of diverticulitis do not lead to more complications and more conservative treatment failure. Moreover, surgery at admission was less frequent among patients who presented with a recurrence.
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Radiotherapy is a well-established therapeutic modality in oncology. It provides survival benefits in several different cancer types. However, cancers relapsing after radiotherapy often develop into more aggressive conditions that are difficult to treat and are associated with poor prognosis. Cumulative experimental evidence indicates that the irradiated tumor bed contributes to such aggressive behavior. The involved mechanisms have for long remained elusive. Recent progress in the field revealed previously unrecognized cellular and molecular events promoting growth, invasion, and metastasis of tumors progressing in an irradiated microenvironment. Cellular mechanisms include inhibition of sprouting angiogenesis, formation of hypoxia, activation and differentiation of stromal cells, and recruitment of bone marrow-derived cells with vasculogenic and prometastatic activities. Identified pathways include TGF-β/ALK5, CXCL12/CXCR4, KITL/KIT, and CYR61/αVβ5 integrin. The availability of pharmacologic inhibitors impinging on these pathways opens novel opportunities for translational and clinical studies. These experimental results and ongoing work highlight the importance of the irradiated microenvironment in modulating the tumor response to radiotherapy and open new opportunities for the development of novel therapeutic strategies for patients with cancer who relapse after radiotherapy. Here, we review and discuss recent advances in the field and their translational and therapeutic implications to human cancer treatment.
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bolism. Surgery was needed in 51% of cases and mortality was 42%. Prosthetic valve endocarditis (nine of 60, 13%) predominated in the aortic position and was associated with abscess formation, required surgery, and high mortality (78%). Pacemaker lead IE (seven of 69, 10%) is associated with a better prognosis when antibiotic treatment is combined with surgery. Conclusions:S lugdunensis IE is an uncommon cause of IE, involving mainly native left sided valves, and it is characterised by an aggressive clinical course. Mortality in left sided native valve IE is high but the prognosis has improved in recent years. Surgery has improved survival in left sided IE and, therefore, early surgery should always be considered. Prosthetic valve S lugdunensis IE carries an ominous prognosis.
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OBJECTIVE: Our objective is to describe pouchography, CT, and MRI features of the J-shaped pouch, both normal and with pouch-related complications. CONCLUSION: Pouchography is performed before closure of the loop ileostomy to assess the integrity of the ileal pouch and anastomosis. CT and MRI can be performed when postoperative complications, such as small-bowel obstruction, pouchitis, leakage, abscess, intramural hematoma, desmoid tumor, or recurrent Crohn's disease, are suspected.