Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The assessment of the skin sensitising capacity of chemicals is up to now investigated using in vivo animal tests. However there has been an increasing public and governmental concern regarding the use of animals for chemical screening. This has raised the need for the development of validated in vitro alternatives. Langerhans cells are potent antigen-presenting cells that play a crucial role in the development of allergic contact dermatitis. We used CD34(+) progenitor-derived dendritic cells from cord blood as an in vitro alternative for Langerhans cells. The cells were exposed to four contact allergens (nickel sulphate, dinitrochlorobenzene, oxazolone and eugenol) and two irritants (sodium dodecyl sulphate and benzalkonium chloride) for 3, 6, 12 and 24h. Using microarray analyses we revealed a set of 25 genes with an altered gene expression pattern after exposure to allergens and not to irritants. Five out of these 25 genes were selected and their gene expression changes were confirmed with real-time reverse transcriptase polymerase chain reaction. The list of 25 genes represent valuable candidates to be further evaluated for their capacity to predict the sensitizing potential of different classes of chemicals in studies using a more extended set of (non) allergic substances.
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PMID:Microarray analyses in dendritic cells reveal potential biomarkers for chemical-induced skin sensitization. 1737 97

TPO (thrombopoietin) and SCF (stem-cell factor) are functionally related cytokines with overlapping but distinct haematopoietic effects. In the present study, a novel TPO-SCF fusion protein that combined the complementary biological effects of TPO and SCF into a single molecule was expressed in, and purified from, Sf9 [Spodoptera frugiperda (fall armyworm)] insect cells. The specific activity of rhTPO (recombinant human TPO)-SCF in megakaryoblastic Mo7e cell proliferation assays was 2.90+/-0.35 x 10(7) units/micromol, approx. 1.7 times as high as that of rhTPO. The specific activity of rhTPO-SCF in TF-1 cells proliferation assays was 7.10+/-0.95 x 10(6) units/micromol, approx. 1.2 times as high as that of rhSCF (recombinant human SCF). In a megakaryocyte-colony-forming assay using human peripheral-blood CD34(+) cells, the SCF moiety of rhTPO-SCF worked in a synergistic way to augment the colony number and exhibited a higher potential to stimulate megakaryocyte colony growth. According to the results of EMSA (electrophoretic mobility-shift assay) and semi-quantitative RT (reverse transcriptase)-PCR, the synergistic effects of the SCF moiety were also reflected in increased STAT5 (signal transducer and activator of transcription 5) DNA binding and enhanced up-regulation of p21 expression in Mo7e cells treated by rhTPO-SCF, suggesting that rhTPO-SCF could be more potent in promoting megakaryocyte proliferation and differentiation.
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PMID:A novel thrombopoietin-stem-cell factor fusion protein possesses enhanced potential in stimulating megakaryocyte proliferation and differentiation. 1751 19

The MHB-2 cell line, established from a mouse hepatoblastoma (HB), was subjected to the reverse transcriptase-polymerase chain reaction (RT-PCR) for evaluation of gene expression related to cell differentiation. RNAs for c-kit, CD34, thy-1, albumin, cytokeratin (CK) 8, 18 and 19 could be detected, but expression of alpha-fetoprotein, glucose-6-phosphatase, tyrosine aminotransferase and CK7 was not observed. MHB-2 cells were positive for CK8/18 but negative for c-kit, CD34, thy-1 and albumin on protein level. Immunohistochemical staining of the HB in vivo revealed diffusely expressed c-kit. Thy-1-positive HB cells were sparsely observed, but the tumor was negative for CD34 and rarely positive for CK8/18. By in situ hybridization, the HB was positive for CK18 but negative for CK19. Slight expression of albumin, but the lack of immature hepatocytic marker suggested some heterogeneous hepatocyte or an undifferentiated cell from other origin. Furthermore, positive expression of CK19 as well as CK8 and CK18 in culture strongly suggested the differentiation into a biliary lineage or the bidirectional state. In conclusion, the present study indicated the mouse HB to have de-differentiated, bipotent, or biliary-like cell characteristics, and considering the histological difference between HB and biliary tumors, it suggests the mouse HB cells are closely like some sort of hepatic undifferentiated cells.
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PMID:Evaluation of gene expression related to hepatic cell maturation and differentiation in a chemically induced mouse hepatoblastoma cell line. 1763 80

We report 20 cases of a distinct, previously unrecognized renal neoplasm, anaplastic sarcoma of the kidney with polyphenotypic features. The tumors were identified by re-reviewing tumors with unusual anaplastic features from the National Wilms Tumor Study Pathology Center, the International Society of Pediatric Oncology and the United Kingdom Children's Cancer Study Group trials. Patients ranged in age from 10 months to 41 years (median age 5 y, mean age 12 y) and females predominated (1.5:1). Twelve tumors presented in the right kidney, and 5 in the left (laterality was unknown in 3 cases). The most common presentation was a renal mass. Grossly, most tumors were large, measured 4 to 21 cm (mean 12.7 cm) and weighed 115 to 1820 g (mean 835 g). Seven out of 12 tumors suitable for assessment had a distinct cystic component. The tumors involved the pelvi-calyceal system in 5 of the cases. Histologically, all tumors showed a spindle cell component which contained either multiple foci or diffuse, widespread anaplastic changes with bizarre pleomorphic cells and very atypical mitotic figures. Chondroid differentiation was seen in 16 cases, usually in the form of islands of hyaline cartilage (13 cases) or chondroid matrix (3 cases). The nodules of cartilage showed both benign and malignant features, often within the same tumor. In 2 cases small foci of osteoid were found whereas osteoclast-like giant cells were seen in 4 cases. Only 3 of the tumors exhibited a primitive blastema-like area. No neoplastic epithelial structures were identified. No nephrogenic rests were found. Limited immunohistochemical studies showed vimentin positivity in 5/5 cases, desmin was positive in 4/6 cases, MYF4 showed focal weak nuclear positivity in 1/4 cases, but MyoD1 was negative in all cases (0/5). PGP9.5 was focally, strongly positive in 4/5 cases and p53 was strongly positive in 3/6 cases. Cytokeratin, using the antibody CAM5.2, was uniformly negative within the tumor cells. Finally, CD56 was focally positive in 1/6 tumors, whereas all other markers were negative including NB84a (4/4), CD34 (5/6), CD99 (5/5), and WT1 (6/6 cases). In 4 tumors reverse transcriptase-polymerase chain reaction was performed to detect the SYT-SSX fusion transcript produced by the t(x;18), and the ETV6-NTRK3 fusion transcript using RNA extracted from archived paraffin blocks-results were negative in all 4 specimens. Tumor stage was known in 15 patients including 7 stage I, 4 stage II, 3 stage III, and 1 stage IV tumors. They were usually diagnosed as anaplastic Wilms tumors and treated accordingly. Of the 13 patients with a minimum of 2 years follow-up, 4 patients developed distant metastases and 1 had local recurrence including 1 patient with stage IV, 2 with stage III, and 2 with stage I at presentation. Three of them died and 2 were lost to follow-up. One patient with stage I tumor developed widespread metastases and died. Another stage I patient developed local recurrence after 3 months of diagnosis, but was lost to follow-up. Five stage I patients were alive and free of tumor at last follow-up. The most common sites of metastases were lung (3 cases), and liver and bones (2 cases each). These tumors showed pathologic features similar to the pleuropulmonary blastoma of childhood and undifferentiated (embryonal) sarcoma of the liver. In the differential diagnosis, anaplastic Wilms tumor, primary renal synovial sarcoma, malignant mesenchymoma, ectomesenchymoma, and mesenchymal chondrosarcomas have been considered but none of these tumors shared the same features as the 20 cases described here which represent a distinct clinicopathologic entity with morphologic features of a polyphenotypic anaplastic sarcoma of the kidney. Further molecular studies are needed to better understand its nature and more accurate classification.
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PMID:Anaplastic sarcoma of the kidney: a clinicopathologic study of 20 cases of a new entity with polyphenotypic features. 1789 46

Two cases of primary prostatic synovial sarcoma presenting as a prostatic mass are presented in patients aged 44 and 46 years. Histologically, both tumors were mainly composed of uniform spindle cells forming interlacing fascicles. Clusters of immature epithelioid cells were also observed among the spindle cells in case 1. Immunohistochemically, the tumor cells of both cases were strongly positive for vimentin, bcl-2, CD99, and E-cadherin, as well as focally positive for cytokeratin. However, they were negative for prostate-specific antigen, S-100 protein, CD34, CD117, muscle-specific actin, desmin, and calretinin. The presence of an SYT-SSX gene fusion resulting from t(X;18) was demonstrated from paraffin blocks by reverse transcriptase polymerase chain reaction in both cases. To the authors' knowledge, these represent the fifth and sixth reported cases of prostatic synovial sarcoma. Accurate diagnosis depends on morphologic and immunohistochemical examination and proper molecular analysis.
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PMID:Primary synovial sarcoma of the prostate: report of 2 cases and literature review. 1838 92

The myelodysplastic syndromes (MDS) include a diverse groups of clonal and potentially malignant bone marrow disorders. Evidences exist that microenvironment cells from MDS marrow show functional abnormalities, which may be relevant to the incidence of such a disease. Mesenchymal stem cells (MSCs) are a very important component of hematopoietic microenvironment. This study was supposed to investigate the biological characteristics and functions of MSC derived from patients with MDS in low-risk. MSCs from bone marrow samples of 11 low-risk MDS patients were isolated, cultured and expanded. Morphology, immunophenotype and osteoblasts differentiation were analyzed. Their capacity of proliferation and hematopoietic supporting in vitro were measured. A real-time quantitative reverse transcriptase polymerase chain reaction method (RQ RT-PCR) was used for detecting the expression levels of relative cytokines and chemokines in MSC. MSCs from healthy donors were used as controls. The results showed that the culture-expanded cells from MDS patients displayed a typical fibroblast-like morphology. Cells were positive for SH2 (CD105), SH3 (CD73), Thy-1 (CD90), while negative for CD34 and CD45. After induction, these cells could differentiate into osteoblasts. The proliferative ability of MSCs in MDS patients were not different from those of MSC isolated from normal bone marrow (p > 0.05), however, their capacity of hematopoietic supporting in vitro were significantly weaker (p < 0.05). RQ RT-PCR detection indicated that the SDF-1 gene expression level in MSCs of low-risk MDS patients was significantly higher than that in MSC derived from healthy donors (p < 0.01). It is concluded that the abnormal function of MSC influences the regulation of hemotopoiesis in the bone marrow microenvironment of MDS patients. It is worthy to further investigate the new clue in etiological mechanism and therapeutic strategies for MDS.
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PMID:In vitro study of biological characteristics of mesenchymal stem cells in patients with low-risk myelodysplastic syndrome. 1871 67

In this study, the authors examined combinations of growth factors that induce effective chondrogenesis from adipose tissue-derived mesenchymal stem cells (MSCs). Human MSCs were isolated from bone marrow (BMMSCs) and adipose tissue (ATMSCs) and characterized according to flow cytometry for CD34, CD45, CD73, and CD166. Chondrogenesis was induced by culturing ATMSCs in pellets without growth factors (negative control) and with 5 ng/mL of transforming growth factor beta 2 (TGF-beta(2)), 100 ng/mL of bone morphogenetic protein (BMP)-2, 100 ng/mL of BMP-6, 100 ng/mL of BMP-7, 5 ng/mL of TGF-beta(2) and 100 ng/mL of BMP-2, 5 ng/mL of TGF-beta(2) and 100 ng/mL of BMP-6, and 5 ng/mL of TGF-beta(2) and 100 ng/mL of BMP-7. BMMSCs cultured under the same condition with 5 ng/mL of TGF-beta(2) were used as positive controls. Flow cytometry showed that ATMSCs and BMMSCs had similar surface marker profiles. After 4 weeks of in vitro culture, glycosaminoglycan assays, real-time reverse transcriptase polymerase chain reaction, and histological findings demonstrated that the combination of 5 ng/mL of TGF-beta(2) and 100 ng/mL of BMP-7 most effectively induced chondrogenesis from ATMSCs. The findings of this study suggest that the combination of TGF-beta(2) and BMP-7 potently enhances chondrogenesis from ATMSCs and can be used to overcome the inferior chondrogenic potential of ATMSCs in cartilage tissue engineering.
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PMID:Combination of transforming growth factor-beta2 and bone morphogenetic protein 7 enhances chondrogenesis from adipose tissue-derived mesenchymal stem cells. 1907 23

The limited plasticity of adult muscle- or bone marrow- derived stem cells intended for cardiac regeneration impedes their conversion into cardiomyocytes. Since murine skeletal muscle was reported to harbor cardiac precursor cells, we assessed whether similar cells exist in man. Skeletal muscle biopsies obtained from 39 patients were sorted by flow cytometry which generated three populations (CD90+/CD34(-), CD34+/CD90(-), CD90(-)/CD34(-)) expressing similar levels of cardiac (Nkx2.5, cTn-T, cTn-I, Cx43) and skeletal muscle (Myf-5, MyoD, myogenin) mRNAs, as assessed by quantitative reverse transcriptase-PCR. However, compared to unpurified myoblasts, CD34+/CD90(-) cells expressed greater amounts of endothelium-specific mRNAs and were, therefore, selected for transplantation experiments. Thirty immunosuppressed rats then underwent coronary artery ligation and, 4 weeks later, were intramyocardially injected with culture medium, myoblasts, or CD34+/CD90(-) cells. After 1 month, left ventricular ejection fraction was significantly higher in the CD34+/CD90(-) group than in the control and myoblast-injected hearts, which was associated with smaller fibrosis and greater angiogenesis. The low engraftment rate suggested a paracrine mechanism supported by the greater release of growth factors by CD34+/CD90(-) cells than by unsorted myoblasts. In conclusion, the human skeletal muscle does not harbor cardiac-specified cells but contains a CD34+ fraction endowed with an angiogenic potential providing superior functional and structural benefits.
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PMID:Does the human skeletal muscle harbor the murine equivalents of cardiac precursor cells? 1922 68

We have shown for the first time that pluripotent/multipotent stem cells can be isolated from blood in a relatively simple cell separation, which is fast and compatible with current standards. We used the germ line- and pluripotent-specific DAZL gene as a marker to demonstrate its use for identifying and isolating pluripotent/multipotent cells from blood. DAZL-expressing (DE) cells were identified in about 0.3% of umbilical cord blood (UCB) mononuclear cells. These DE cells do not express either blood cell differentiation markers, such as CD38, CD3, and CD14, or the blood progenitor cell markers, such as CD34 and CD133. Nevertheless, they express pluripotent embryonic stem (ES) cells OCT-4 and SOX-2 genes. To examine whether the DE cells exhibit stem cell characteristics, we seeded 10(3) DE cells in methylcellulose containing the ingredients needed for hematopoietic cell growth. Although DE cells are CD34-, a mean (+/-SD) of 21 +/- 4 colonies were formed per plate, of which 4.8% were colony-forming unit granulocyte, erythroid, macrophage, megakaryocytes (CFU-GEMMs). Mononuclear or CD34+ cells isolated from UCB formed 6 +/- 1 and 53 +/- 8 colonies per plate, respectively, of which 0% and 3.8% were CFU-GEMMs. DE cells grown in methylcellulose without cytokines formed various colonies, which demonstrated expression pattern that is typical of neurons, endothelial, bone/cartilage, cardiomyocyte, and hepatocyte differentiation as determined by reverse transcriptase-PCR (RT-PCR). Our results suggest that DE cells, which possess some pluripotent/multipotent characteristics of ES cells, can be easily isolated from blood. These cells may be effective in various therapeutic applications with no biological or ethical ramifications.
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PMID:A method for isolating pluripotent/multipotent stem cells from blood by using the pluripotent and germ-line DAZL gene as a marker. 1932 14

Induction of an antigenically broad and vigorous primary T-cell immune response by myeloid dendritic cells (DC) in blood and tissues could be important for an effective prophylactic or therapeutic vaccine to human immunodeficiency virus type 1 (HIV-1). Here we show that a primary CD8(+) T-cell response can be induced by HIV-1 peptide-loaded DC derived from blood monocytes of HIV-1-negative adults and neonates (moDC) and by Langerhans cells (LC) and interstitial, dermal-intestinal DC (idDC) derived from CD34(+) stem cells of neonatal cord blood. Optimal priming of single-cell gamma interferon (IFN-gamma) production by CD8(+) T cells required CD4(+) T cells and was broadly directed to multiple regions of Gag, Env, and Nef that corresponded to known and predicted major histocompatibility complex class I epitopes. Polyfunctional CD8(+) T-cell responses, defined as single-cell production of more than one cytokine (IFN-gamma, interleukin 2, or tumor necrosis factor alpha), chemokine (macrophage inhibitory factor 1beta), or cytotoxic degranulation marker CD107a, were primed by moDC, LC, and idDC to HIV-1 Gag and reverse transcriptase epitopes, as well as to Epstein-Barr virus and influenza A virus epitopes. Thus, three major types of blood and tissue myeloid DC targeted by HIV-1, i.e., moDC, LC, and idDC, can prime multispecific, polyfunctional CD8(+) T-cell responses to HIV-1 and other viral antigens.
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PMID:Primary human immunodeficiency virus type 1-specific CD8+ T-cell responses induced by myeloid dendritic cells. 1935 76


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