38 research outputs found

    Dedifferentiation of Human Primary Thyrocytes into Multilineage Progenitor Cells without Gene Introduction

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    While identification and isolation of adult stem cells have potentially important implications, recent reports regarding dedifferentiation/reprogramming from differentiated cells have provided another clue to gain insight into source of tissue stem/progenitor cells. In this study, we developed a novel culture system to obtain dedifferentiated progenitor cells from normal human thyroid tissues. After enzymatic digestion, primary thyrocytes, expressing thyroglobulin, vimentin and cytokeratin-18, were cultured in a serum-free medium called SAGM. Although the vast majority of cells died, a small proportion (∼0.5%) survived and proliferated. During initial cell expansion, thyroglobulin/cytokeratin-18 expression was gradually declined in the proliferating cells. Moreover, sorted cells expressing thyroid peroxidase gave rise to proliferating clones in SAGM. These data suggest that those cells are derived from thyroid follicular cells or at least thyroid-committed cells. The SAGM-grown cells did not express any thyroid-specific genes. However, after four-week incubation with FBS and TSH, cytokeratin-18, thyroglobulin, TSH receptor, PAX8 and TTF1 expressions re-emerged. Moreover, surprisingly, the cells were capable of differentiating into neuronal or adipogenic lineage depending on differentiating conditions. In summary, we have developed a novel system to generate multilineage progenitor cells from normal human thyroid tissues. This seems to be achieved by dedifferentiation of thyroid follicular cells. The presently described culture system may be useful for regenerative medicine, but the primary importance will be as a tool to elucidate the mechanisms of thyroid diseases

    Metastasis from follicular lymphoma to an ovarian mature teratoma: a case report of tumor-to-tumor metastasis

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    Abstract Background Tumor-to-tumor metastasis (TTM) is a rare but well-established phenomenon where histologically distinct tumors metastasize within each other. Here we report the first “known” case of follicular lymphoma that metastasized and extended to a mature ovarian teratoma. Case presentation A 59-year-old Japanese postmenopausal woman visited our hospital for a detailed examination of an ovarian tumor. Clinical imaging suggested it to be either teratoma-associated ovarian cancer with multiple lymph node metastases, or tumor-to-tumor metastasis from malignant lymphoma to ovarian teratoma. A bilateral adnexectomy and retroperitoneal lymph node biopsy were performed. Lined with squamous epithelium, the cyst constituted a mature ovarian teratoma, and the solid part showed diffuse proliferation of abnormal lymphoid cells. Immunohistochemically, the abnormal lymphoid cells were negative for CD5, MUM1, and CyclinD1, and positive for CD10, CD20, CD21, BCL2, and BCL6. Genetic analysis using G-banding and fluorescence in situ hybridization identified a translocation of t(14;18) (q32;q21), and we diagnosed tumor-to-tumor metastasis from nodal follicular lymphoma to mature ovarian teratoma. Twelve months after surgery, the patient showed no progression without adjuvant therapy. Conclusions The present case suggests that molecular approaches are useful in the diagnosis of TTM in mature ovarian teratomas when morphologic and immunohistochemical findings alone are insufficient for diagnoses

    Carrier Localization Suppression by Multipath Transport in Helical Polyacetylene

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    The conduction sites in the main chain of helical polyacetylene (HPA) are arranged in a unique helical configuration, whereas conventional conductive polymers such as <i>cis</i>-polyacetylene and <i>trans</i>-polyacetylene have almost collinearly aligned conduction sites. Here we report the distinctive hole transport properties in HPA caused by the helical structure. Analyses of the hole diffusion with different models of the range of transfer integrals (TIs) reveal that the helical configuration produces multiple conduction paths in HPA. The holes propagate through multiple pathways, avoiding local paths with small TIs. This mechanism suppresses the localization of electronic states in HPA, which is inevitable in conventional one-dimensional conductive polymers

    Two cesarean deliveries after hemi-hysterectomy due to gestational trophoblastic neoplasia

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    Objective: Although uterine didelphys per se is not associated with an impaired ability to conceive, the association between uterine anomalies and gestational trophoblastic neoplasia (GTN) remains unclear. The management of chemotherapy-resistant GTN in women with uterine didelphys raises a new issue regarding whether to perform a hemi-hysterectomy. Case report: A 23-year-old, gravida 1, para 0 Japanese woman was referred with a failed intermittent cervical dilatation for hematometra. Four years previously, she developed a GTN Stage III, score 5. As two cycles of chemotherapy with methotrexate (MTX) and one cycle of EMA-CO (etoposide, MTX, actinomycin D, cyclophosphamide and vincristine) did not result in remission, we performed an abdominal hemi-hysterectomy. After a canalization procedure and cervicoplasty were performed, the patient conceived naturally and prematurely delivered by cesarean section twice. Conclusion: A hemi-hysterectomy should be considered for fertility preservation when GTN develops on either side of a didelphic uterus and adjuvant chemotherapy does not result in remission. Keywords: Adjuvant chemotherapy, Fertility preservation, Gestational trophoblastic disease, Hysterectomy, Anomalie
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