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Editorial. Discusses the practice of endomyocardial biopsies for the evaluation of cardiac transplant status in children. Difference in the incidence of cellular rejection between patients receiving tacrolimus and cyclosporine; Factors considered in the evaluation of cardiac biopsies; Rate of rejection diagnosed in endomyocardial biopsies.

Microvillus inclusion disease (MVTD) is a severe form of congenital diarrhea that arises from inactivating mutations in the gene encoding myosin Vb (MYO5B). We have examined the association of mutations in MYO5B and disruption of microvillar assembly and polarity in enterocytes. Stable MYO5B knockdown (MYO5B-KD) in CaCo2-BBE cells elicited loss of microvilli, alterations in junctional claudins, and disruption of apical and basolateral trafficking; however, no microvillus inclusions were observed in MYO5B-KD cells. Expression of WT MYO5B in MYO5B-KD cells restored microvilli; however, expression of MYO5B-P660L, a MVID-associated mutation found within Navajo populations, did not rescue the MYO5B-KD phenotype but induced formation of microvillus inclusions. Microvilli establishment required interaction between RAB8A and MYO5B, while loss of the interaction between RAB11A and MYO5B induced microvillus inclusions. Using surface biotinylation and dual immunofluorescence staining in MYO5B-KD cells expressing mutant forms of MYO5B, we observed that early microvillus inclusions were positive for the sorting marker SNX18 and derived from apical membrane internalization. In patients with MVID, MYO5B-P660L results in global changes in polarity at the villus tips that could account for deficits in apical absorption, loss of microvilli, aberrant junctions, and losses in transcellular ion transport pathways, likely leading to the MVID clinical phenotype of neonatal secretory diarrhea. [ABSTRACT FROM AUTHOR]

Background: The insulin-like growth factor-1 (IGF-1) signaling pathway plays an important role in the pathology of Ewing sarcoma (ES). Retrospective studies have suggested that levels of IGF-1 and IGF binding protein 3 (IGFBP-3) are correlated with the outcome of patients with ES.Methods: The IGF-1 signaling pathway was investigated prospectively in 269 patients who had localized, previously untreated ES. Serum samples were obtained at diagnosis, and concentrations of IGF-1 and IGFBP-3 were determined by enzyme-linked immunosorbent assays. In addition, immunohistochemistry (IHC) was performed to assay for phosphorylated p70S6 kinase, protein kinase B (Akt), and forkhead box protein O1 (FOXO1) and to determine the presence of protein tyrosine phosphatase-L1 (PTPL1). IHC findings along with IGF-1 and IGFBP-3 concentrations were correlated with age, tumor location, sex, event-free survival, and overall survival.Results: Patients aged >18 years tended to have higher levels of IGF-1 (P = .10), lower levels of IGFBP-3 (P = .16), and decreased IGFBP-3:IGF-1 ratios (P = .01). No correlations were observed between sex, tumor location, or outcomes and concentrations of IGF-1 or IGFBP-3. Phosphorylation of p70S6 kinase, Akt, and FOXO1 was detected in the majority of patient tissues but was not associated with age, sex, or tumor location. PTPL1 was present in >80% of tumors and also was not correlated with age, sex, or tumor location. There was no difference in survival with respect to the presence of phosphorylated p70S6 kinase, phosphorylated FOXO1, phosphorylated Akt, or PTPL1.Conclusions: The baseline IGFBP-3:IGF-1 ratio was correlated with age but did not affect the outcomes of patients with ES. The authors concluded that additional investigation of the IGF-1 pathway is warranted in patients with ES, and especially in those who have received treatment with IGF-1 receptor antibody inhibitors. [ABSTRACT FROM AUTHOR]

BACKGROUND: The insulin-like growth factor-1 (IGF-1) signaling pathway plays an important role in the pathology of Ewing sarcoma (ES). Retrospective studies have suggested that levels of IGF-1 and IGF binding protein 3 (IGFBP-3) are correlated with the outcome of patients with ES. METHODS: The IGF-1 signaling pathway was investigated prospectively in 269 patients who had localized, previously untreated ES. Serum samples were obtained at diagnosis, and concentrations of IGF-1 and IGFBP-3 were determined by enzyme-linked immunosorbent assays. In addition, immunohistochemistry (IHC) was performed to assay for phosphorylated p70S6 kinase, protein kinase B (Akt), and forkhead box protein O1 (FOXO1) and to determine the presence of protein tyrosine phosphatase-L1 (PTPL1). IHC findings along with IGF-1 and IGFBP-3 concentrations were correlated with age, tumor location, sex, event-free survival, and overall survival. RESULTS: Patients aged >18 years tended to have higher levels of IGF-1 ( P = .10), lower levels of IGFBP-3 ( P = .16), and decreased IGFBP-3:IGF-1 ratios ( P = .01). No correlations were observed between sex, tumor location, or outcomes and concentrations of IGF-1 or IGFBP-3. Phosphorylation of p70S6 kinase, Akt, and FOXO1 was detected in the majority of patient tissues but was not associated with age, sex, or tumor location. PTPL1 was present in >80% of tumors and also was not correlated with age, sex, or tumor location. There was no difference in survival with respect to the presence of phosphorylated p70S6 kinase, phosphorylated FOXO1, phosphorylated Akt, or PTPL1. CONCLUSIONS: The baseline IGFBP-3:IGF-1 ratio was correlated with age but did not affect the outcomes of patients with ES. The authors concluded that additional investigation of the IGF-1 pathway is warranted in patients with ES, and especially in those who have received treatment with IGF-1 receptor antibody inhibitors. Cancer 2011;. © 2011 American Cancer Society. [ABSTRACT FROM AUTHOR]

Presents the protocol in examining specimens of pediatric and adult patients with osseous and extraosseous ewing sarcoma family of tumors, including peripheral primitive neuroectodermal tumor and ewing, developed by the College of American Pathologists. Importance of the protocol for pathologists; Background and documentation of the protocol; Scope and limitation of the protocol.

Background: Ewing's sarcoma and primitive neuroectodermal tumor of bone are closely related, highly malignant tumors of children, adolescents, and young adults. A new drug combination, ifosfamide and etoposide, was highly effective in patients with Ewing's sarcoma or primitive neuroectodermal tumor of bone who had a relapse after standard therapy. We designed a study to test whether the addition of these drugs to a standard regimen would improve the survival of patients with newly diagnosed disease. Methods: Patients 30 years old or younger with Ewing's sarcoma, primitive neuroectodermal tumor of bone, or primitive sarcoma of bone were eligible. The patients were randomly assigned to receive 49 weeks of standard chemotherapy with doxorubicin, vincristine, cyclophosphamide, and dactinomycin or experimental therapy with these four drugs alternating with courses of ifosfamide and etoposide. Results: A total of 518 patients met the eligibility requirements. Of 120 patients with metastatic disease, 62 were randomly assigned to the standard-therapy group and 58 to the experimental-therapy group. There was no significant difference in five-year event-free survival between the treatment groups (P=0.81). Among the 398 patients with nonmetastatic disease, the mean (±SE) five-year event-free survival among the 198 patients in the experimental-therapy group was 69±3 percent, as compared with 54±4 percent among the 200 patients in the standard-therapy group (P=0.005). Overall survival was also significantly better among patients in the experimental-therapy group (72±3.4 percent vs. 61±3.6 percent in the standard-therapy group, P=0.01). Conclusions: The addition of ifosfamide and etoposide to a standard regimen does not affect the outcome for patients with metastatic disease, but it significantly improves the outcome for patients with nonmetastatic Ewing's sarcoma, primitive neuroectodermal tumor of bone, or primitive sarcoma of bone. N Engl J Med 2003;348:694-701. [ABSTRACT FROM AUTHOR]

Background: Epstein–Barr virus (EBV) has been associated with nasopharyngeal carcinoma, some lymphomas, and lymphoproliferative disease after organ transplantation. Many lymphoproliferative tumors that occur after transplantation are clonal, a property that classifies them as neoplastic. Clonality can be determined by analysis of the extrachromosomal circular DNA episomes produced by EBV infection. Methods: We describe three young children in whom smooth-muscle tumors developed 18 months to 5 years after liver transplantation with immunosuppression. We examined the tumors by microscopy and with immunohistochemical studies and molecular genetic analyses of the EBV DNA. Results: The tumors were composed of spindle cells with smooth-muscle features and resembled those described in patients with the acquired immunodeficiency syndrome. Immunohistochemical analysis was negative for EBV latent membrane protein and EBV receptor (CD21), but positive for EBV nuclear antigen 2. In situ hybridization revealed nuclear EBV sequences, and molecular genetic analysis showed the EBV genome to be clonal in all three patients. Conclusions: Smooth-muscle tumors that developed after organ transplantation contained clonal EBV, suggesting that the virus has a role in the development of these neoplastic lesions. (N Engl J Med 1995;332:19-25.) [ABSTRACT FROM AUTHOR]