355 research outputs found

    The presence of Y674/Y675 phosphorylated NTRK1 via TP53 repression of PTPN6 expression as a potential prognostic marker in neuroblastoma

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    The tumor suppressor TP53 promotes nerve growth factor receptor (NTRK1) -Y674/Y675 phosphorylation (NTRK1-pY674/pY675) via repression of the NTRK1 phosphatase PTPN6 in a ligand-independent manner, resulting in suppression of breast cancer cell proliferation. Moreover, NTRK1-pY674/pY675 together with low levels of PTPN6 and TP53 expression is associated with favorable disease-free survival of breast cancer patients. We determined whether in neuroblastoma this protein expression pattern impacts relapse-free survival (RFS). NTRK1-pY674/pY675, PTPN6, and TP53 expression was assessed in 98 neuroblastoma samples by immunohistochemistry. Association between expression levels and RFS was investigated by multivariate and Kaplan-Meier analysis. Mutant or wild-type TP53 was identified by sequencing tumor DNA. Tumors expressing NTRK1-pY674/pY675 and low or undetectable levels of PTPN6 and TP53 were significantly associated with 5-year RFS (P = .014) when the dataset was stratified by MYCN amplification, segmental chromosomal abnormalities and histology. Similar results were observed with tumors expressing wild-type TP53, NTRK1-pY674/pY675 and low or undetectable levels of PTPN6. Kaplan-Meier analysis demonstrated a significant correlation (P = .004), with a 50% probability of RFS (median survival 4.73 years) when present compared with 19.51% (median survival 11.63 months) when absent. Similar results were seen with non-amplified MYCN or unfavorable/undifferentiating samples and tumors from patients aged 18 months or less. Importantly, NTRK1-pY674/pY675 is an independent predictor of improved RFS. These results strongly suggest that NTRK1-pY674/pY675 together with wild-type TP53 and undetectable or low levels of PTPN6 expression is a potential biomarker of improved RFS of neuroblastoma patients. The predictive value of NTRK1-pY674/pY675 together with wild-type TP53 and low PTPN6 expression could contribute to neuroblastoma patient prognosis

    Enhancing the utility of antroduodenal manometry in pediatric intestinal pseudo-obstruction

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    BACKGROUND: Antroduodenal manometry (ADM) and histopathology are currently employed to aid the diagnosis of pediatric intestinal pseudo-obstruction (PIPO). Limited data are available on the reliability of ADM analysis and its correlation with histopathology. We aimed to develop a protocol for enhanced analysis of ADM contractile patterns, including a scoring system, and explore whether this provided better correlation with histopathology. METHODS: Children referred with suspected PIPO between April 2012-December 2019 who underwent both ADM and full-thickness biopsies were included. ADM tracings were analyzed using both standard (conventional ADM) and novel (enhanced ADM) motility parameters. A novel ADM score (GLASS score) was generated based on the enhanced ADM analysis. Conventional and enhanced ADM analyses were then correlated with histopathology. RESULTS: Forty patients were included. Using conventional clinical criteria, 29 of these were diagnosed with PIPO and the other 11 with non-PIPO diagnoses. Twenty-three of the PIPO patients had abnormal histopathology: 6 myopathy, 4 neuropathy, 3 neuro-myopathy, and 10 non-specific changes. No agreement in diagnosis was found between conventional ADM analysis and histopathology (ϰ = 0.068; p = 0.197), whereas the latter significantly correlated with enhanced ADM analysis (ϰ = 0.191; p = 0.003). The enhanced ADM score was significantly higher in PIPO versus non-PIPO (16.0 vs. 8.0; p < 0.001). CONCLUSIONS: As opposed to conventional analysis protocols, the newly developed enhanced ADM analysis and associated score is not only able to discriminate between PIPO and non-PIPO patients, but also between distinct histopathological pathologies. Further studies are required to assess the utility of enhanced ADM analysis in larger populations

    Selective in vitro replication of herpes simplex virus type 1 (HSV-1) ICP34.5 null mutants in primary human CNS tumours--evaluation of a potentially effective clinical therapy.

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    Primary tumours of the central nervous system (CNS) are an important cause of cancer-related deaths in adults and children. CNS tumours are mostly glial cell in origin and are predominantly astrocytomas. Conventional therapy of high-grade gliomas includes maximal resection followed by radiation treatment. The addition of adjuvant chemotherapy provides little improvement in survival time and hence assessment of novel therapies is imperative. We have evaluated the potential therapeutic use of the herpes simplex virus (HSV) mutant 1716 in the treatment of primary brain tumours. The mutant is deleted in the RL1 gene and fails to produce the virulence factor ICP34.5. 1716 replication was analysed in both established human glioma cell lines and in primary cell cultures derived from human tumour biopsy material. In the majority of cultures, virus replication occurred and consequential cell death resulted. In the minority of tumour cell lines which are non-permissive for mutant replication, premature shut-off of host cell protein synthesis was induced in response to lack of expression of ICP34.5. Hence RL1-negative mutants have the distinct advantage of providing a double hit phenomenon whereby cell death could occur by either pathway. Moreover, 1716, by virtue of its ability to replicate selectively within a tumour cell, has the potential to deliver a 'suicide' gene product to the required site immediately. It is our opinion that HSV which fails to express ICP34.5 could provide an effective tumour therapy

    Correction of both immunodeficiency and hypoparathyroidism by thymus transplantation in complete DiGeorge Syndrome

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    Combined immune deficiency due to athymia in patients with complete DiGeorge syndrome can be corrected by allogeneic thymus transplantation. Hypoparathyroidism is a frequent concomitant clinical problem in these patients, which persists after thymus transplantation. Cotransplantation of allogeneic thymus and parental parathyroid tissue has been attempted but does not achieve durable correction of the patients' hypoparathyroidism due to parathyroid graft rejection. Surprisingly, we observed correction of hypoparathyroidism in one patient after thymus transplantation. Immunohistochemical analysis and fluorescence in situ hybridization confirmed the presence of allogeneic parathyroid tissue in the patient's thymus transplant biopsy. Despite a lack of HLA‐matching between thymus donor and recipient, the reconstituted immune system displays tolerance toward the thymus donor. Therefore we expect this patient's hypoparathyroidism to be permanently cured. It is recognised that ectopic parathyroid tissue is not infrequently found in the thymus. If such thymuses could be identified, we propose that their use would offer a compelling approach to achieving lasting correction of both immunodeficiency and hypoparathyroidism
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