218 research outputs found

    Intravital microscopy of biosensor activities and intrinsic metabolic states

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    Intravital microscopy (IVM) is an imaging tool that is capable of detecting subcellular signaling or metabolic events as they occur in tissues in the living animal. Imaging in highly scattering biological tissues, however, is challenging because of the attenuation of signal in images acquired at increasing depths. Depth-dependent signal attenuation is the major impediment to IVM, limiting the depth from which significant data can be obtained. Therefore, making quantitative measurements by IVM requires methods that use internal calibration, or alternatively, a completely different way of evaluating the signals. Here, we describe how ratiometric imaging of genetically encoded biosensor probes can be used to make quantitative measurements of changes in the activity of cell signaling pathways. Then, we describe how fluorescence lifetime imaging can be used for label-free measurements of the metabolic states of cells within the living animal

    Programmed Death Ligand 2 in Cancer-Induced Immune Suppression

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    Inhibitory molecules of the B7/CD28 family play a key role in the induction of immune tolerance in the tumor microenvironment. The programmed death-1 receptor (PD-1), with its ligands PD-L1 and PD-L2, constitutes an important member of these inhibitory pathways. The relevance of the PD-1/PD-L1 pathway in cancer has been extensively studied and therapeutic approaches targeting PD-1 and PD-L1 have been developed and are undergoing human clinical testing. However, PD-L2 has not received as much attention and its role in modulating tumor immunity is less clear. Here, we review the literature on the immunobiology of PD-L2, particularly on its possible roles in cancer-induced immune suppression and we discuss the results of recent studies targeting PD-L2 in cancer

    Alteration of N-glycans related to articular cartilage deterioration after anterior cruciate ligament transection in rabbits

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    SummaryObjectiveOsteoarthritis (OA) is the most common of all joint diseases, but the molecular basis of its onset and progression is controversial. Several studies have shown that modifications of N-glycans contribute to pathogenesis. However, little attention has been paid to N-glycan modifications seen in articular cartilage. The goal of this study was to identify disease specific N-glycan expression profiles in degenerated cartilage in a rabbit OA model induced by anterior cruciate ligament transection (ACLT).MethodsCartilage samples were harvested at 7, 10, 14, and 28 days after ACLT and assessed for cartilage degeneration and alteration in N-glycans. N-Glycans from cartilage were analyzed by high performance liquid chromatography and mass spectrometry.ResultsHistological analysis showed that osteoarthritic changes in cartilage occurred 10 days after ACLT. Apparent alterations in the N-glycan peak pattern in cartilage samples were observed 7 days after ACLT, and overall N-glycan changes in OA reflected alterations in both sialylation and fucosylation. These changes apparently preceded histological changes in cartilage.ConclusionThese results indicate that changes in the expression of N-glycans are correlated with OA in an animal model. Understanding mechanisms underlying changes in N-glycans seen in OA may be of therapeutic value in treating cartilage deterioration

    Desenvolvimento de protótipo embarcado para automatização da medida do tempo de cozimento de feijão.

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    O presente trabalho propicia o fortalecimento do protocolo de intenções entre a Pontifícia Universidade Católica de Goiás ? PUC-GO e a Embrapa, na geração de benefícios sociais, envolvendo equipe multidisciplinar, que propõe a finalização e validação de um produto envolvendo o hardware e software para se obter a automatização dessa análise laboratorial.CONAFE

    Full recovery of a 13-year-old boy with pediatric Ramsay Hunt syndrome using a shorter course of aciclovir and steroid at lower doses: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Reports on children with Ramsay Hunt syndrome are limited in the literature, resulting in uncertainty regarding the clinical manifestations and outcome of this syndrome. Treatment for Ramsay Hunt syndrome is usually with antivirals, although there is no evidence for beneficial effect on the outcome of Ramsay Hunt syndrome in adults (insufficient data on children exists). Here, we report a case of Ramsay Hunt syndrome occurring in a child who inadvertently received a lower dose of aciclovir and steroid administered for shorter than is usual. Our patient made a full recovery.</p> <p>Case presentation</p> <p>A 13-year-old African boy presented to our out-patients department with an inability to move the right side of his face for one week. He had previously been seen by the doctor on call, who prescribed aciclovir 200 mg three times per day and prednisone 20 mg once daily, both orally for five days, with a working diagnosis of Bell's palsy. After commencement of aciclovir-prednisone, while at home, our patient had headache, malaise, altered taste, vomiting after feeds, a ringing sound in his right ear as well as earache and ear itchiness. Additionally, he developed numerous fluid-filled pimples on his right ear. On presentation, a physical examination revealed a right-sided lower motor neuron facial nerve palsy and a healing rash on the right pinna. On direct questioning, our patient admitted having had chicken pox about three months previously. Based on the history and physical examination, Ramsay Hunt syndrome was diagnosed. Our patient was lost to follow-up until 11 months after the onset of illness; at this time, his facial nerve function was normal.</p> <p>Conclusions</p> <p>This case report documents the clinical manifestations and outcome of pediatric Ramsay Hunt syndrome; a condition with few case reports in the literature. In addition, our patient made a full recovery despite inadvertently receiving a lower dose of aciclovir and steroid administered for shorter than is usual.</p

    Human CD1c+ DCs are critical cellular mediators of immune responses induced by immunogenic cell death

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    Chemotherapeutics, including the platinum compounds oxaliplatin (OXP) and cisplatin (CDDP), are standard care of treatment for cancer. Although chemotherapy has long been considered immunosuppressive, evidence now suggests that certain cytotoxic agents can efficiently stimulate antitumor responses, through the induction of a form of apoptosis, called immunogenic cell death (ICD). ICD is characterized by exposure of calreticulin and heat shock proteins (HSPs), secretion of ATP and release of high-mobility group box 1 (HMGB1). Proper activation of the immune system relies on the integration of these signals by dendritic cells (DCs). Studies on the crucial role of DCs, in the context of ICD, have been performed using mouse models or human in vitro-generated monocyte-derived DCs (moDCs), which do not fully recapitulate the in vivo situation. Here, we explore the effect of platinum-induced ICD on phenotype and function of human blood circulating DCs. Tumor cells were treated with OXP or CDDP and induction of ICD was investigated. We show that both platinum drugs triggered translocation of calreticulin and HSP70, as well as the release of ATP and HMGB1. Platinum treatment increased phagocytosis of tumor fragments by human blood DCs and enhanced phenotypic maturation of blood myeloid and plasmacytoid DCs. Moreover, upon interaction with platinum-treated tumor cells, CD1c+ DCs efficiently stimulated allogeneic proliferation of T lymphocytes. Together, our observations indicate that platinum-treated tumor cells may exert an active stimulatory effect on human blood DCs. In particular, these data suggest that CD1c+ DCs are critical mediators of immune responses induced by ICD

    Management of peripheral facial nerve palsy

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    Peripheral facial nerve palsy (FNP) may (secondary FNP) or may not have a detectable cause (Bell’s palsy). Three quarters of peripheral FNP are primary and one quarter secondary. The most prevalent causes of secondary FNP are systemic viral infections, trauma, surgery, diabetes, local infections, tumor, immunological disorders, or drugs. The diagnosis of FNP relies upon the presence of typical symptoms and signs, blood chemical investigations, cerebro-spinal-fluid-investigations, X-ray of the scull and mastoid, cerebral MRI, or nerve conduction studies. Bell’s palsy may be diagnosed after exclusion of all secondary causes, but causes of secondary FNP and Bell’s palsy may coexist. Treatment of secondary FNP is based on the therapy of the underlying disorder. Treatment of Bell’s palsy is controversial due to the lack of large, randomized, controlled, prospective studies. There are indications that steroids or antiviral agents are beneficial but also studies, which show no beneficial effect. Additional measures include eye protection, physiotherapy, acupuncture, botulinum toxin, or possibly surgery. Prognosis of Bell’s palsy is fair with complete recovery in about 80% of the cases, 15% experience some kind of permanent nerve damage and 5% remain with severe sequelae

    Survival of metastatic melanoma patients after dendritic cell vaccination correlates with expression of leukocyte phosphatidylethanolamine-binding protein 1/Raf kinase inhibitory protein

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    Immunotherapy for metastatic melanoma offers great promise but, to date, only a subset of patients have responded. There is an urgent need to identify ways of allocating patients to the most beneficial therapy, to increase survival and decrease therapy-associated morbidity and costs. Blood-based biomarkers are of particular interest because of their straightforward implementation in routine clinical care. We sought to identify markers for dendritic cell (DC) vaccine-based immunotherapy against metastatic melanoma through gene expression analysis of peripheral blood mononuclear cells. A large-scale microarray analysis of 74 samples from two treatment centers, taken directly after the first round of DC vaccination, was performed. We found that phosphatidylethanolamine binding protein 1 (_PEBP1_)/ Raf Kinase inhibitory protein (RKIP) expression can be used to identify a significant proportion of patients who performed poorly after DC vaccination. This result was validated by q-PCR analysis on blood samples from a second cohort of 95 patients treated with DC vaccination in four different centers. We conclude that low _PEBP1_ expression correlates with poor overall survival after DC vaccination. Intriguingly, this was only the case for expression of _PEBP1_ after, but not prior to, DC vaccination. Moreover, the change in _PEBP1_ expression upon vaccination correlated well with survival. Further analyses revealed that _PEBP1_ expression positively correlated with genes involved in T cell responses but inversely correlated with genes associated with myeloid cells and aberrant inflammation including _STAT3, NOTCH1,_ and _MAPK1_. Concordantly, _PEBP1_ inversely correlated with the myeloid/ lymphoid-ratio and was suppressed in patients suffering from chronic inflammatory disease

    G12/13 Signaling Pathways Substitute for Integrin αIIbβ3-Signaling for Thromboxane Generation in Platelets

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    We have previously shown that ADP-induced TXA(2) generation requires signaling from αIIbβ3 integrin in platelets. Here we observed that, unlike ADP, protease-activated receptor (PAR)-mediated TXA(2) generation occurs independently of αIIbβ3. PAR agonists, but not ADP, activate G(12/13) signaling pathways. Hence, we evaluated the role of these pathways in TXA(2) generation.Inhibition of ADP-induced thromboxane generation by fibrinogen receptor antagonist SC57101 was rescued by co-stimulation of G(12/13) pathways with YFLLRNP. This observation suggested an existence of a common signaling effector downstream of integrins and G(12/13) pathways. Hence, we evaluated role of three potential tyrosine kinases; c-Src, Syk and FAK (Focal Adhesion Kinase) that are known to be activated by integrins. c-Src and Syk kinase did not play a role in ADP-induced functional responses in platelets. Selective activation of G(12/13) pathways resulted in the activation of FAK, in the absence of integrin signaling. Interestingly, αIIbβ3-mediated FAK activation occurred in a Src family kinase (SFK)-independent manner whereas G(12/13) pathway caused FAK activation in a SFK and RhoA-dependent manner. A FAK selective inhibitor TAE-226, blocked TXA(2) generation. However, in comparison to WT mice, Pf4-Cre/Fak-Floxed mice did not show any difference in platelet TXA(2) generation.Therefore, we conclude that differential activation of FAK occurs downstream of Integrins and G(12/13) pathways. However, the common effector molecule, possibly a tyrosine kinase downstream of integrins and G(12/13) pathways contributing to TXA(2) generation in platelets remains elusive
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