Search

Erythropoietin (EPO) induces erythropoiesis in vitro as well as in vivo, and the process of erythroid differentiation has been explored phenotypically and morphologically. However, morphological analysis of in vitro erythropoiesis of human hematopoietic progenitor cells at the ultrastructural level has not been reported before. In the present study, we have traced the ultrastructural changes of erythroid differentiation during ex vivo expansion of human cord blood (CB) CD34+ cells in the presence of EPO by electron microscopy (EM), along with concurrent phenotypic analysis. CD34+ cells purified from ten CBs by immunomagnetic selection were cultured in serum-free essential media in the presence of a combination of the several cytokines including EPO, thrombopoietin, flt3-ligand (FL), stem cell factor (SCF), granulocyte colony-stimulating factor, interleukin (IL)-3 and/or IL-11. Phenotypic analysis was performed by flow cytometric analysis for erythroid markers, including glycophorin C (GPC), Kell-related, glycophorin A (GPA), band 3, Lub, and RhD. Ultrastructural analysis was performed by electron-microscopic examination of the cultured cells stained with uranyl acetate and lead citrate. Phenotypic analysis revealed that in the absence of EPO, genuine erythroid fraction expressing the typical pattern of erythroid markers did not appear. The order of the above markers expressed in the cultured cells in the presence of EPO was GPC, Kell-related, GPA, band 3, Lub, and RhD, irrespective of the type of cytokine added. Of the cytokines used in combination with EPO, FL + IL-3 was the most efficient in inducing erythroid differentiation, which was followed by SCF + IL-3. EM examination demonstrated complete process of erythroid development from pronormoblasts to reticulocytes with nuclei having been extruded and mature erythrocytes. These results suggest that morphologically intact erythrocytes could be produced by ex vivo expansion of CB CD34+ cells using EPO. [ABSTRACT FROM AUTHOR]

Thrombopoietin (TPO) is one of the most promising stimulants for ex vivo expansion of haematopoietic stem cells. Previously, we have found that TPO induces a characteristic pattern of apoptosis during ex vivo expansion of human cord blood (CB) CD34+ cells and that the TPO-induced apoptotic cells belong to megakaryocyte (MK) lineage. In this study, we have examined the maturation of MK and platelet production in association with the TPO-induced apoptosis. CD34+ cells, purified from human CB, were expanded in serum-free conditions stimulated with TPO. Apoptosis was confirmed by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) assay and electron microscopy (EM). Simultaneous measurement of DNA content and immunophenotyping revealed that the cells with higher DNA content (>8 N) constituted less than 5% of the CD41+ fractions until day 14, implying premature apoptosis of MKs before full polyploidization. Nevertheless, EM observation showed not only platelet territories but also newly produced platelets in which granules and microfilaments could be identified. Furthermore, flow cytometry demonstrated that the platelet fraction expressed P-selectin and an activation motif on GPIIb/IIIa recognized by monoclonal antibody PAC-1 upon stimulation with adenosine diphosphate (ADP). In addition, periodic acid-Schiff (PAS)-positive materials and nonspecific esterase activities could be demonstrated. Therefore, it is suggested that platelet production and the accompanying processes, rather than apoptosis only, be hastened during the ex vivo expansion of CB CD34+ cells when using TPO. [ABSTRACT FROM AUTHOR]

Abstract Background Breast cancer in females and prostate cancer in males are two of the most common cancers in the United States, and the literature suggests that they share similar features. However, it is unknown whether the occurrence of these two cancers at the county level in the United States is correlated. We analyzed Caucasian age-adjusted county level average annual incidence rates for breast and prostate cancers from the National Cancer Institute and State Cancer Registries to determine whether there was a spatial correlation between the two conditions and whether the two cancers had similar spatial patterns. Results There was a significant correlation between breast and prostate cancers by county (r = 0.332, p < 0.001). This relationship was more pronounced when we performed a geographically-weighted regression (GWR) analysis (r = 0.552) adjusting for county unemployment rates. There was variation in the parameter estimates derived with the GWR; however, the majority of the estimates indicted a positive association. The strongest relationship between breast and prostate cancer was in the eastern parts of the Midwest and South, and the Southeastern U.S. We also observed a north-south pattern for both cancers with our cluster analyses. Clusters of counties with high cancer incidence rates were more frequently found in the North and clusters of counties with low incidence rates were predominantly in the South. Conclusion Our analyses suggest breast and prostate cancers cluster spatially. This finding corroborates other studies that have found these two cancers share similar risk factors. The north-south distribution observed for both cancers warrants further research to determine what is driving this spatial pattern.

Although not as common as solitary lesions, multiple schwannomas do occur, even in single nerve lesions. We report a rare case of a 47-year-old female patient who presented with multiple schwannomas with inter-fascicular invasion in the ulnar nerve above the cubital tunnel. Preoperative MRI revealed a 10-cm multilobulated tubular mass along the ulnar nerve above the elbow joint. During excision under 4.5° loupe magnification, we separated three ovoid yellow-colored neurogenic tumors of different sizes, but there were still remaining lesions as it was difficult to completely separate lesions from the ulnar nerve due to the risk of iatrogenic nerve ulnar nerve injury. The operative wound was closed. Postoperative biopsy confirmed the diagnosis of the three schwannomas. During the follow-up, the patient recovered without neurological symptom or limitations in range of motion, and there were no neurological abnormalities. At 1year after surgery, small lesions remained in the most proximal part. However, the patient had no clinical symptoms and was satisfied with the surgical results. Although a long-term follow-up is necessary for this patient, we were able to obtain good clinical and radiological results., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Archetypal human pluripotent stem cells (hPSC) are widely considered to be equivalent in developmental status to mouse epiblast stem cells, which correspond to pluripotent cells at a late post-implantation stage of embryogenesis. Heterogeneity within hPSC cultures complicates this interspecies comparison. Here we show that a subpopulation of archetypal hPSC enriched for high self-renewal capacity (ESR) has distinct properties relative to the bulk of the population, including a cell cycle with a very low G1 fraction and a metabolomic profile that reflects a combination of oxidative phosphorylation and glycolysis. ESR cells are pluripotent and capable of differentiation into primordial germ cell-like cells. Global DNA methylation levels in the ESR subpopulation are lower than those in mouse epiblast stem cells. Chromatin accessibility analysis revealed a unique set of open chromatin sites in ESR cells. RNA-seq at the subpopulation and single cell levels shows that, unlike mouse epiblast stem cells, the ESR subset of hPSC displays no lineage priming, and that it can be clearly distinguished from gastrulating and extraembryonic cell populations in the primate embryo. ESR hPSC correspond to an earlier stage of post-implantation development than mouse epiblast stem cells.

The study and application of human pluripotent stem cells (hPSCs) will be enhanced by the availability of well-characterized monoclonal antibodies (mAbs) detecting cell-surface epitopes. Here, we report generation of seven new mAbs that detect cell surface proteins present on live and fixed human ES cells (hESCs) and human iPS cells (hiPSCs), confirming our previous prediction that these proteins were present on the cell surface of hPSCs. The mAbs all show a high correlation with POU5F1 (OCT4) expression and other hPSC surface markers (TRA-160 and SSEA-4) in hPSC cultures and detect rare OCT4 positive cells in differentiated cell cultures. These mAbs are immunoreactive to cell surface protein epitopes on both primed and naive state hPSCs, providing useful research tools to investigate the cellular mechanisms underlying human pluripotency and states of cellular reprogramming. In addition, we report that subsets of the seven new mAbs are also immunoreactive to human bone marrow-derived mesenchymal stem cells (MSCs), normal human breast subsets and both normal and tumorigenic colorectal cell populations. The mAbs reported here should accelerate the investigation of the nature of pluripotency, and enable development of robust cell separation and tracing technologies to enrich or deplete for hPSCs and other human stem and somatic cell types. Stem Cells 2017;35:626-640., (© 2016 The Authors Stem Cells published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.)

We demonstrate that a combination of Noggin, Dickkopf-1, Insulin Growth Factor 1 and basic Fibroblast Growth Factor, promotes the differentiation of human pluripotent stem cells into retinal pigment epithelium (RPE) cells. We describe an efficient one-step approach that allows the generation of RPE cells from both human embryonic stem cells and human induced pluripotent stem cells within 40-60 days without the need for manual excision, floating aggregates or imbedded cysts. Compared to methods that rely on spontaneous differentiation, our protocol results in faster differentiation into RPE cells. This pro-retinal culture medium promotes the growth of functional RPE cells that exhibit key characteristics of the RPE including pigmentation, polygonal morphology, expression of mature RPE markers, electrophysiological membrane potential and the ability to phagocytose photoreceptor outer segments. This protocol can be adapted for feeder, feeder-free and serum-free conditions. This method thereby provides a rapid and simplified production of RPE cells for downstream applications such as disease modelling and drug screening.

Purpose: To describe a patient with acinic cell carcinoma of the lacrimal gland presenting with atypical manifestations including erosion of the orbital roof and intracranial extension. We compare his clinical manifestations with two previously reported cases., Methods: Case report., Results: A 51-year-old man presented with a firm, tender, palpable mass in the superior temporal portion of his right orbit. CT scan demonstrated a large homogeneously enhancing mass displacing the globe inferiorly and eroding the roof of the orbit. MRI of the orbit showed intracranial extension of tumor. Biopsy revealed an acinic cell carcinoma of the lacrimal gland., Conclusions: Acinic cell carcinoma is a rare neoplasm occurring primarily in the major and minor salivary glands.

Apoptosis is responsible for the loss of thyrocytes in autoimmune thyroiditis. Recent investigations into the pathogenesis of apoptosis have revealed that the important roles of suicide molecules expression on both thyrocytes and cytotoxic T-lymphocytes. To study the mechanism of thyrocyte loss in various forms of thyroiditis, we evaluated in situ expression patterns of CD40, Fas, and Fas-L on thyrocytes and infiltrating inflammatory cells by immunohistochemical staining of thyroid samples obtained from 49 patients (Graves' disease, n=10: Hashimoto's thyroiditis, n=14; nonspecific lymphocytic thyroiditis, n=11; subacute granulomatous thyroiditis, n=11; normal, n=3). The role of cytotoxic T-lymphocytes was also evaluated by analyzing the expression of granzyme B along with their phenotypic characteristics. CD40 was not expressed on thyrocytes of normal controls while they showed a diffuse expression of Fas and a scattered focal expression of Fas-L. The plump thyrocytes proximal to the inflammatory infiltrates showed more intense expressions of these three molecules in various forms of thyroiditis and a close correlation was found between CD40 and Fas-L expression on thyrocytes. Unlike Fas, which was expressed on infiltrating lymphocytes in all groups, Fas-L was not expressed on infiltrating lymphocytes, except those in subacute granulomatous thyroiditis. Granzyme B expressing activated cytotoxic T-lymphocytes occupied a negligible proportion of CD8+ T-lymphocytes in various forms of thyroiditis, and no difference was found in terms of their proportions according to the type of thyroiditis. These results show the acquisition of CD40, Fas and Fas-L molecules on thyrocytes proximal to inflammatory cell aggregates and the negligible expression of granzyme B and Fas-L on the infiltrating lymphocytes, and suggest that Fas and Fas-L mediated apoptosis of thyrocytes (fratricide) may be more important than T cell-mediated cytotoxicity in various forms of thyroiditis.

Primary testicular carcinoid tumor, occupying 0.23% of testicular neoplasm, is a rare and indolent neoplasm with the potential for distant metastasis. We present two cases of primary pure carcinoid tumor of the testis. Both patients were 36 years old. Physical examination revealed testicular mass with and without tenderness. The preoperative serum levels of beta-human chorionic gonadotropin and alpha-fetoprotein were normal and neither patient had carcinoid syndrome. The tumors measured 7.5x6x4 cm and 5.5x5x4 cm in size. Histologically, immunohistochemically and ultrastructurally, the tumors showed typical features of the carcinoid tumor. Case 1 showed extensive tumor necrosis and vascular invasion. DNA flow cytometric analysis showed aneuploidy with DNA index of 1.47 and S+G2M of 14.0% in case 1 and tetraploidy with DNA index of 1.96 and S+G2M of 22.1% in case 2. Both patients have been well without any signs of metastasis after operation for 24 months in case 1 and for 16 months in case 2.

Dieulafoy lesion is an uncommon cause of gastrointestinal bleeding, reported to be only 2% of acute or chronic upper gastrointestinal bleeding episodes. Bleeding occurs from a small mucosal erosion involving an unusually large submucosal artery in an otherwise normal mucosa. It is associated with massive, life threatening hemorrhage and is difficult to diagnosis. In most cases the lesion is encountered in the proximal stomach, antrum, duodenum, colon and rectum. In particular, extragastric Dieulafoy lesion is an extremely rare source of intestinal bleeding. In Korea, no case of bleeding from a Dieulafoy lesion of the small intestine has been previously reported. We experienced one case of bleeding from a jejunal Dieulafoy lesion, which was confirmed by the pathologic examination of the resected specimen, and report here.

Myxoma is a rare nonepithelial neoplasm of the larynx frequently misdiagnosed as a large vocal polyp due to its slow-growing nature. Myxoma is a benign but often infiltrating neoplasm of uncertain mesenchymal cell origin, characterized by irregular round, spindle or stellate cells within a matrix containing abundant mucoid material, scant vascularity and a variable meshwork of reticulum and collagen. We report one case of myxoma with life-threatening dyspnea requiring tracheotomy.