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1.
干细胞及其在人类医学上的应用前景 总被引：1，自引：0，他引：1
干细胞是指从胚胎、胎儿或成年个体各种组织中分离出来的多能性细胞 ,具有体外保持未分化状态的无限增殖能力 ,在不同条件下可诱导分化为不同的细胞类型、组织甚至器官。胚胎癌细胞、胚胎干细胞、胚胎生殖细胞和成年组织干细胞是目前研究的几类主要干细胞 ,它们除作为发育生物学研究的细胞模型外 ,在人类医学领域也具有潜在的应用价值 相似文献
2.
The cancer stem cell hypothesis postulates that tumor growth is driven by a rare subpopulation of tumor cells. Much of the supporting evidence for this intriguing idea is derived from xenotransplantation experiments in which human leukemia cells are grown in immunocompromised mice. We show that, when lymphomas and leukemias of mouse origin are transplanted into histocompatible mice, a very high frequency (at least 1 in 10) of the tumor cells can seed tumor growth. We suggest that the low frequency of tumor-sustaining cells observed in xenotransplantation studies may reflect the limited ability of human tumor cells to adapt to growth in a foreign (mouse) milieu. 相似文献
3.
探讨骨髓间充质干细胞(MSCs)移植对大鼠脑缺血的修复和治疗.体外分离培养大鼠MSCs,以Hoeschst33342标记,移植到大脑中动脉梗塞(MCAO)模型的大鼠体内,分别设立缺血1 d和缺血7 dMSCs移植组与缺血对照组,对各组大鼠进行神经功能损害严重程度评分(NSS)及大脑组织切片观察比较.结果发现,缺血1 d MSCs移植组大鼠NSS评分低于另外两组,差异显著(P＜0.05),大脑组织结构清晰、完整,胶质瘢痕少;缺血7 d MSCs移植组与对照组无明显差异(P＞0.05).故缺血早期进行MSCs移植,大鼠神经功能恢复情况明显.MSCs在损伤后的脑组织内能够存活并且分化为神经元、胶质细胞等,对动物神经损伤后组织重建及功能恢复有一定的治疗作用. 相似文献
4.
Alteration of T-cell functions by infection with HTLV-I or HTLV-II 总被引：18，自引：0，他引：18
M Popovic N Flomenberg D J Volkman D Mann A S Fauci B Dupont R C Gallo 《Science (New York, N.Y.)》1984,226(4673):459-462
Two functionally different types of human T-cell clones, one with helper function and two with specific activity, were infected with different isolates of HTLV-I and HLTV-II. Both types of human T cells showed alterations in specific function after infection with either of the HTLV subgroups. Before HTLV infection, the T-cell clone with helper function proliferates and provides help to B cells only in the presence of both a specific soluble antigen (keyhole limpet hemocyanin) and histocompatible antigen-presenting cells. After HTLV infection, these cells respond with increased proliferation and indiscriminant stimulation of polyclonal immunoglobulin production by B cells, regardless of the histocompatibility of the antigen-presenting cells or the presence of the soluble antigen. Infection of the normal cytotoxic T-cell clones led to a dimunition or loss of the cytotoxic function. The results of these studies suggest some possible mechanisms for induction of immune deficiency and of polyclonal B-cell activation by viruses of the HTLV family. 相似文献
5.
Pluripotent cells in the embryo can generate all cell types, but lineage-restricted cells are generally thought to replenish adult tissues. Planarians are flatworms and regenerate from tiny body fragments, a process requiring a population of proliferating cells (neoblasts). Whether regeneration is accomplished by pluripotent cells or by the collective activity of multiple lineage-restricted cell types is unknown. We used ionizing radiation and single-cell transplantation to identify neoblasts that can form large descendant-cell colonies in vivo. These clonogenic neoblasts (cNeoblasts) produce cells that differentiate into neuronal, intestinal, and other known postmitotic cell types and are distributed throughout the body. Single transplanted cNeoblasts restored regeneration in lethally irradiated hosts. We conclude that broadly distributed, adult pluripotent stem cells underlie the remarkable regenerative abilities of planarians. 相似文献
6.
To rigorously test the in vivo cell fate specificity of bone marrow (BM) hematopoietic stem cells (HSCs), we generated chimeric animals by transplantation of a single green fluorescent protein (GFP)-marked HSC into lethally irradiated nontransgenic recipients. Single HSCs robustly reconstituted peripheral blood leukocytes in these animals, but did not contribute appreciably to nonhematopoietic tissues, including brain, kidney, gut, liver, and muscle. Similarly, in GFP+:GFP- parabiotic mice, we found substantial chimerism of hematopoietic but not nonhematopoietic cells. These data indicate that "transdifferentiation" of circulating HSCs and/or their progeny is an extremely rare event, if it occurs at all. 相似文献
7.
Translating stem and progenitor cell biology to the clinic: barriers and opportunities 总被引：1，自引：0，他引：1
Weissman IL 《Science (New York, N.Y.)》2000,287(5457):1442-1446
Stem cells are the natural units of embryonic generation, and also adult regeneration, of a variety of tissues. Recently, the list of tissues that use the model of differentiation from stem to progenitor to mature cell has increased from blood to include a variety of tissues, including both central and peripheral nervous systems and skeletal muscle; it is also possible that all organs and tissues are derived from, and still contain, stem cells. Because the number and activities of stem cells and their progeny are homeostatically regulated, clinical stem cell transplantation could greatly add to the physician's armamentarium against degenerative diseases. 相似文献
8.
Chamberlain JR Schwarze U Wang PR Hirata RK Hankenson KD Pace JM Underwood RA Song KM Sussman M Byers PH Russell DW 《Science (New York, N.Y.)》2004,303(5661):1198-1201
Adult stem cells offer the potential to treat many diseases through a combination of ex vivo genetic manipulation and autologous transplantation. Mesenchymal stem cells (MSCs, also referred to as marrow stromal cells) are adult stem cells that can be isolated as proliferating, adherent cells from bones. MSCs can differentiate into multiple cell types present in several tissues, including bone, fat, cartilage, and muscle, making them ideal candidates for a variety of cell-based therapies. Here, we have used adeno-associated virus vectors to disrupt dominant-negative mutant COL1A1 collagen genes in MSCs from individuals with the brittle bone disorder osteogenesis imperfecta, demonstrating successful gene targeting in adult human stem cells. 相似文献
9.
Antigenic relationships in mammalian DNA polymerase 总被引：7，自引：0，他引：7
Rabbit antibody was prepared against a high-molecular-weight DNA polymerase purified from the soluble fraction of calf thymus gland. This antibody does not inhibit terminal deoxynucleotidyl transferase isolated from that source, but does inhibit both low-molecular-weight and high-molecular-weight DNA polymerases isolated from cytoplasmic and nuclear fractions of a number of mammalian tissues (mouse L cells, calf thymus, phytohemagglutinin-stimulated human lymphocytes, rat liver, and rabbit bone marrow). The results suggest that (i) no antigenic relationship exists between terminal transferase and DNA polymerase, (ii) common antigenic determinants exist in the DNA polymerases from all mammalian sources, and (iii) multiple forms of DNA polymerase found in mammalian, cells are related by having polypeptide sequences or subunits in common. 相似文献
10.
Generalized potential of adult neural stem cells 总被引：1，自引：0，他引：1
Clarke DL Johansson CB Wilbertz J Veress B Nilsson E Karlström H Lendahl U Frisén J 《Science (New York, N.Y.)》2000,288(5471):1660-1663
The differentiation potential of stem cells in tissues of the adult has been thought to be limited to cell lineages present in the organ from which they were derived, but there is evidence that some stem cells may have a broader differentiation repertoire. We show here that neural stem cells from the adult mouse brain can contribute to the formation of chimeric chick and mouse embryos and give rise to cells of all germ layers. This demonstrates that an adult neural stem cell has a very broad developmental capacity and may potentially be used to generate a variety of cell types for transplantation in different diseases. 相似文献
11.
Cranial neural crest cells generate the distinctive bone and connective tissues in the vertebrate head. Classical models of craniofacial development argue that the neural crest is prepatterned or preprogrammed to make specific head structures before its migration from the neural tube. In contrast, recent studies in several vertebrates have provided evidence for plasticity in patterning neural crest populations. Using tissue transposition and molecular analyses in avian embryos, we reconcile these findings by demonstrating that classical manipulation experiments, which form the basis of the prepatterning model, involved transplantation of a local signaling center, the isthmic organizer. FGF8 signaling from the isthmus alters Hoxa2 expression and consequently branchial arch patterning, demonstrating that neural crest cells are patterned by environmental signals. 相似文献
12.
C C Congdon 《Science (New York, N.Y.)》1971,171(976):1116-1124
The goals in bone marrow transplantation are its application to the treatment of diseases arising in the blood-forming tissues of man. Techniques for procuring and grafting marrow are of the needle-and-syringe type and are based on the normal physiological processes in which stem cells circulate through blood and other fluids of the mammalian organism. Destruction of bone marrow by irradiation, chemicals, or unknown agencies provides the immediate experimental system for demonstrating the therapeutic value of marrow transplants. Genetic diseases characterized by abnormal marrow function are also modifiable by grafts of blood-forming tissues. Studies with identical twins are critical experiments for showing the clinical value of grafts, even though the transplanted cells cannot be identified by the usual marker techniques. Among the best results seen with marrow grafting is the presumed cure of certain rare hereditary immune-deficiency disorders of children. A major problem in bone marrow transplantation-one that delays its wider clinical application-is the immune reaction from cells growing out of the foreign transplant which attack the host (the graft-versus-host reaction). Attempts to use a graft-versus-host response to eliminate tumor cells is a part of the marrow research program. The history of the processes that led to some of the achieved goals in marrow grafting shows the usual multicentric origin of an idea. Certain individuals play critical roles in developing the idea. Finally, a body of knowledge is accumulated that opens up or limits prospects for the future. In bone marrow transplantati on, future achievements will depend in part on the progress that is made in the areas of cell separation, bone marrow banking, and tissue culture. 相似文献
13.
Production of Transgenic Animals Using Spermatogonial Stem Cells 总被引：1，自引：0，他引：1
MIAO Xiang-yang 《中国农业科学(英文版)》2011,10(5):762-768
Spermatogonial stem cells (SSCs) are a type of adult stem cell found in male mammals. These cells have the capacity for self renewal and are capable of differentiating in the niche of testis. They are also the only adult stem cells in a normal postnatal body that undergo self-renewal throughout life, transferring genetic information to the offspring. Since a technique for transplanting SSCs was first described by Brinster and his colleagues in 1994, more and more researchers have become interested in exploring the possibility of utilizing adult SSCs to generate transgenic animals. In this minireview, we attempt to summarize the current research progress in the area of spermatogonial stem cells including the source, types and differentiation of the SSCs, and the application on transgenic animals, with a particular focus on the strategy of SSCs delivery including seminiferous tubule injection and spermatogonial stem cell transplantation. 相似文献
14.
Cellular localization of somatomedin (insulin-like growth factor) messenger RNA in the human fetus 总被引：49，自引：0，他引：49
The somatomedins or insulin-like growth factors (IGFs) are synthesized in many organs and tissues, but the specific cells that synthesize them in vivo have not been defined. By in situ hybridization histochemistry, IGF I (somatomedin C) and IGF II messenger RNAs were localized to connective tissues or cells of mesenchymal origin in 14 organs and tissues from human fetuses. IGF messenger RNAs were localized to perisinusoidal cells of liver, to perichondrium of cartilage, to sclera of eye, and to connective tissue layers, sheaths, septa, and capsules of each organ and tissue. All of the hybridizing regions are comprised predominantly of fibroblasts or other cells of mesenchymal origin. Because these cells are widely distributed and anatomically integrated into tissues and organs, they are ideally located for production of IGFs, which may exert paracrine effects on nearby target cells. 相似文献
15.
G F Schreiner W Flye E Brunt K Korber J B Lefkowith 《Science (New York, N.Y.)》1988,240(4855):1032-1033
A central hypothesis in transplantation biology is that resident leukocytes expressing class II histocompatibility antigens may determine the immunogenicity of an organ. By means of a novel method to deplete the kidney of resident leukocytes, essential fatty acid deficiency (EFAD), this hypothesis was tested in an intact, vascular organ. Kidneys subjected to EFAD and thus depleted of resident Ia-positive macrophages survived and functioned when transplanted across a major histocompatibility antigen barrier in the absence of immunosuppression of the recipient. Control allografts were rejected promptly. Allografts from donors subjected to EFAD normalized their lipid composition and were repopulated with host macrophages by 5 days. Administration of Ia-positive cells at the time of transplantation established that the resident leukocyte depletion induced by EFAD was responsible for the protective effect. These observations may provide insights into the mechanisms underlying tissue immunogenicity and the population of normal tissues with resident leukocytes. 相似文献
16.
Hwang WS Roh SI Lee BC Kang SK Kwon DK Kim S Kim SJ Park SW Kwon HS Lee CK Lee JB Kim JM Ahn C Paek SH Chang SS Koo JJ Yoon HS Hwang JH Hwang YY Park YS Oh SK Kim HS Park JH Moon SY Schatten G 《Science (New York, N.Y.)》2005,308(5729):1777-1783
Patient-specific, immune-matched human embryonic stem cells (hESCs) are anticipated to be of great biomedical importance for studies of disease and development and to advance clinical deliberations regarding stem cell transplantation. Eleven hESC lines were established by somatic cell nuclear transfer (SCNT) of skin cells from patients with disease or injury into donated oocytes. These lines, nuclear transfer (NT)-hESCs, grown on human feeders from the same NT donor or from genetically unrelated individuals, were established at high rates, regardless of NT donor sex or age. NT-hESCs were pluripotent, chromosomally normal, and matched the NT patient's DNA. The major histocompatibility complex identity of each NT-hESC when compared to the patient's own showed immunological compatibility, which is important for eventual transplantation. With the generation of these NT-hESCs, evaluations of genetic and epigenetic stability can be made. Additional work remains to be done regarding the development of reliable directed differentiation and the elimination of remaining animal components. Before clinical use of these cells can occur, preclinical evidence is required to prove that transplantation of differentiated NT-hESCs can be safe, effective, and tolerated. 相似文献
17.
诱导性多能干细胞的研究及应用 总被引：1，自引：0，他引：1
自从小鼠的胚胎成纤维细胞和鼠尾成纤维细胞重编程成为诱导多能干细胞（induced pluripotent stem cells,iPSCs）以来,iPS的研究成了干细胞研究领域的热点。与胚胎干细胞相比,iPS细胞有操作简便和高稳定性等优点可以应用于,如创建人类疾病的遗传模型,培育转基因动物用于器官移植,改善动物生产性状和抗病性,以及生物制药等领域。另外,iPSCs的产生对于解决长期以来干细胞研究领域的伦理问题和免疫排斥问题有巨大的意义,iPS结合基因治疗和细胞移植疗法的成果已经应用到了动物疾病模型上。iPS细胞技术给病人特定细胞治疗和基因针对性药品研制带来了巨大的前景。此外,该技术也提供了iPS细胞重编程机制和人类疾病的病理过程研究的新平台。然而,现阶段多能干细胞的研究只是开辟了一个新的领域,iPS技术要应用于临床还有很多工作要做。本文主要针对iPSCs的研究现状与应用前景进行讨论。 相似文献
18.
Cellular and molecular mechanisms underlying differences in beak morphology likely involve interactions among multiple embryonic populations. We exchanged neural crest cells destined to participate in beak morphogenesis between two anatomically distinct species. Quail neural crest cells produced quail beaks in duck hosts and duck neural crest produced duck bills in quail hosts. These transformations involved morphological changes to non-neural crest host beak tissues. To achieve these changes, donor neural crest cells executed autonomous molecular programs and regulated gene expression in adjacent host tissues. Thus, neural crest cells are a source of molecular information that generates interspecific variation in beak morphology. 相似文献
19.
XUE Chun-lin MAO Da-gan YANG Li-guo CHENG Bao 《中国农业科学(英文版)》2007,6(7):882-889
To study the immune effect of CpGDNA on somatostatin （SS） DNA vaccine, the 20-day-old experimental mice were immunized with 20 lag SS eukaryotic expression plasmid pES/2SS with different adjuvants in equal dose, such as the synthetic CpG-ODN, the pE-CpG plasmid, E. coli DNA and the crude liposome. A booster was given two weeks later. The results showed that the body weight gain of female mice in the SS immunized group was higher than that of the control （P 〈0.05）. The levels of antibodies against SS, IgG2a/IgG1, spleen lymphocyte proliferation activity and the concentrations of GH and IGF-Ⅰ in the DNA vaccine groups combined with CpGDNA were significantly increased compared to that of the group immunized with DNA vaccine alone. All these suggested the recombinant SS expression plasmid can stimulate animals to produce antibodies against SS, and CpGDNA adjuvant can enhance the immune effect of DNA vaccine against SS and influence the concentration of GH and IGF-Ⅰ . 相似文献
20.
Correlation of leukocyte groups with skin and renal allograft survival indicates that ranks of histocompatibility based upon current genetic concepts of the HL-A system may provide an approach to the selection of optimally compatible subjects for clinical organ transplantation. Such ranks may be expressed as a net histocompatibility ratio (NHR) between prospective donors and recipients. The best clinical results have been when this ratio is of 0.5 to 1. Donor-recipient compatibility situations where the ratio was 0.25 or less have been associated with a high incidence of transplant failure, regardless of whether the organ source was a living, related donor or a cadaver donor. 相似文献