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Regulation of expression of the interleukin-2 receptor on hematopoietic cells by interleukin-3 总被引：4，自引：0，他引：4
M C Birchenall-Sparks W L Farrar D Rennick P L Kilian F W Ruscetti 《Science (New York, N.Y.)》1986,233(4762):455-458
Remarkable similarities in the intracellular and genetic events occur when lymphoid and hematopoietic cells are exposed to their specific growth factors. The interleukin-2 (IL-2) receptor, whose cell-surface expression is an absolute requirement for the growth and differentiation of lymphoid cells, was detected on various nonlymphoid hematopoietic cell types in this study. Cell lines consisting either of granulocyte-macrophage precursors or mast cells, which are dependent on interleukin-3 (IL-3) for their growth, expressed high levels of the IL-2 receptor on their surface. Analysis of the binding characteristics of these receptors with 125I-labeled recombinant IL-2 revealed that only receptors with low affinity for IL-2 were present on these cells. Addition of purified recombinant IL-3 to these cell lines led to an increase in IL-2 receptor gene expression within 1 hour in isolated nuclei. This IL-3--induced increase in the number of IL-2 receptors on the cell surface is maximal within 24 hours. Addition of 10,000 units of IL-2 to these cells had no apparent effect on their growth or differentiation. The presence of the receptor with only low affinity for IL-2 on hematopoietic cells and the regulation by IL-3 suggest that this receptor is involved in some important metabolic event in hematopoiesis. 相似文献
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Malignant transformation of erythroid cells in vivo by introduction of a nonreplicating retrovirus vector 总被引：26，自引：0，他引：26
DNA from a replication-defective spleen focus-forming virus (SFFV) was reconstructed and transfected into psi-2 cells containing a packaging-defective mutant of Moloney murine leukemia virus. Replication-incompetent retrovirus particles (helper virus-free containing genomes that express the transforming envelope gene of SFFV (gp52) transformed bone marrow cells in vitro and, after direct intravenous introduction of the vector, induced malignant erythroid disease in vivo. Disease induction was dependent on prior treatment of mice with phenylhydrazine, which probably increased the availability of erythroid target cells. Since there was no evidence of virus particle expression in mice with malignant disease, this study demonstrates the acute oncogenic potential of a limited number of erythroid cells expressing SFFV gp52. Direct inoculation of animals with nonreplicating retroviral vectors containing transforming genes may be useful in study the oncogenic effects of such genes. 相似文献
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FTV Pereira FC Braga KC Burioli JR Kfoury Jr LJ Oliveira PC Papa AF Carvalho CE Ambrósio FW Bazer MA Miglino 《Reproduction in domestic animals》2010,45(5):907-914
The objectives of this investigation were to understand transplacental transport of iron by secreted uteroferrin (UF) and haemophagous areas of water buffalo placenta and clarify the role(s) of blood extravasation at the placental‐maternal interface. Placentomes and interplacentomal region of 51 placentae at various stages of gestation were fixed, processed for light and transmission electron microscopy, histochemistry and immunohistochemistry. Haemophagous areas were present in placentomes collected between 4 and 10 months of pregnancy. Perl’s reaction for ferric iron was negative in placentomes, but positive in endometrial glands. Positive staining for UF indicated areas in which it was being taken up by phagocytosis and/or fluid phase pinocytosis in areolae of the interplacentomal mesenchyme, with little staining in endometrial stroma. Imunohistochemistry detected UF in trophectoderm of haemophagous regions of placentomes and in other parts of the foetal villous tree, but the strongest immunostaining was in the epithelial cells and lumen of uterine glands. Ultrastructural analyses indicated that erythrophagocytosis was occurring and that erythrocytes were present inside cells of the chorion that also contained endocytic vesicles and caveolae. Results of this study indicate that both the haemophagous areas of placentomes and the areolae at the interface between chorion and endometrial glands are important sites for iron transfer from mother to foetal‐placental tissues in buffalo throughout pregnancy. 相似文献
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DE Boerner RD Kurtz JA Craven GM Ross FW Jones WJ Davis 《Science (New York, N.Y.)》1999,283(5402):668-670
The subcrustal lithosphere underlying the southern Archean Churchill Province (ACP) in western Canada is at least one order of magnitude more electrically conductive than the lithosphere beneath adjacent Paleoproterozoic crust. The measured electrical properties of the lithosphere underlying most of the Paleoproterozoic crust can be explained by the conductivity of olivine. Mantle xenolith and geological mapping evidence indicate that the lithosphere beneath the southern ACP was substantially modified as a result of being trapped between two nearly synchronous Paleoproterozoic subduction zones. Tectonically induced metasomatism thus may have enhanced the subcrustal lithosphere conductivity of the southern ACP. 相似文献
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When confronted with a novel familial disorder, veterinarians should consult McKusick's catalogue of inherited disorders in humans, called Mendelian Inheritance in Man (MIM), or its online version (OMIM), to see whether a similar disorder has been reported in humans. They should also consult the other readily available sources of comparative information on mice and domesticated species. Increasingly, such consultations can be conducted on the Internet via the World Wide Web. If it is thought that an animal disorder is homologous with a human disorder, publications describing the animal disorder should include the MIM number(s) for that disorder. Future research can then test the hypothesis of homology, until a consensus is reached. 相似文献
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Chondrodysplasia in Australian Dexter cattle 总被引：1，自引：0，他引：1
Objective To describe the occurrence of chondrodysplasia in Australian Dexter cattle.
Design A pathological and genetic case report.
Procedure Congenital lethal chondrodysplasia was studied in two female Dexter foetuses aborted mid to late gestation. Clinicopathological findings including histological changes in limb bones, and analysis of pedigree information were evaluated.
Results Characteristic features of congenital lethal chon-drodysplasia (Dexter bulldog) include abortion, disproportionate dwarfism, a short vertebral column, marked micromelia, a relatively large head with retruded muzzle, cleft palate and protruding tongue and a large abdominal hernia. Histological changes in limb bones are consistent with failure of endochondral ossification. Dexter chondrodysplasia is considered to be inherited in an incompletely dominant manner with the homozygous form producing the congenital lethal condition. A preliminary minimum estimate of heterozy-gote frequency is 19% within the registered Australian Dexter herd, based on analysis of the contribution of three obligate heterozygotes whose semen has been widely used by artificial insemination in Australia.
Conclusion Dexter chondrodysplasia is present in Australian cattle and further cases of the homozygous form, congenital lethal chondrodysplasia, are likely to occur.
Recommendation It is requested that spleen and liver tissue from bulldog foetuses and blood from their parents be collected to assist research into Dexter chondrodysplasia. 相似文献
Design A pathological and genetic case report.
Procedure Congenital lethal chondrodysplasia was studied in two female Dexter foetuses aborted mid to late gestation. Clinicopathological findings including histological changes in limb bones, and analysis of pedigree information were evaluated.
Results Characteristic features of congenital lethal chon-drodysplasia (Dexter bulldog) include abortion, disproportionate dwarfism, a short vertebral column, marked micromelia, a relatively large head with retruded muzzle, cleft palate and protruding tongue and a large abdominal hernia. Histological changes in limb bones are consistent with failure of endochondral ossification. Dexter chondrodysplasia is considered to be inherited in an incompletely dominant manner with the homozygous form producing the congenital lethal condition. A preliminary minimum estimate of heterozy-gote frequency is 19% within the registered Australian Dexter herd, based on analysis of the contribution of three obligate heterozygotes whose semen has been widely used by artificial insemination in Australia.
Conclusion Dexter chondrodysplasia is present in Australian cattle and further cases of the homozygous form, congenital lethal chondrodysplasia, are likely to occur.
Recommendation It is requested that spleen and liver tissue from bulldog foetuses and blood from their parents be collected to assist research into Dexter chondrodysplasia. 相似文献
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Simmons G Glynn SA Komaroff AL Mikovits JA Tobler LH Hackett J Tang N Switzer WM Heneine W Hewlett IK Zhao J Lo SC Alter HJ Linnen JM Gao K Coffin JM Kearney MF Ruscetti FW Pfost MA Bethel J Kleinman S Holmberg JA Busch MP;Blood XMRV Scientific Research Working Group 《Science (New York, N.Y.)》2011,334(6057):814-817
Murine leukemia viruses (MLVs), including xenotropic-MLV-related virus (XMRV), have been controversially linked to chronic fatigue syndrome (CFS). To explore this issue in greater depth, we compiled coded replicate samples of blood from 15 subjects previously reported to be XMRV/MLV-positive (14 with CFS) and from 15 healthy donors previously determined to be negative for the viruses. These samples were distributed in a blinded fashion to nine laboratories, which performed assays designed to detect XMRV/MLV nucleic acid, virus replication, and antibody. Only two laboratories reported evidence of XMRV/MLVs; however, replicate sample results showed disagreement, and reactivity was similar among CFS subjects and negative controls. These results indicate that current assays do not reproducibly detect XMRV/MLV in blood samples and that blood donor screening is not warranted. 相似文献
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