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We studied the effect of retinal polypeptide Retinalamin on multipotent ectodermal cells of the early gastrula of Xenopus laevis. Neuronal differentiation of the early gastrula ectoderm including the brain, retina, and pigment epithelium depended on Retinalamin concentration.
Six cases of epithelioid sarcoma were studied by conventional light microscopy and immunohistochemistry. The six cases account for 1.4% of the 417 cases of soft tissue sarcoma collected at the Paediatric Tumor Registry, Kiel. The average age of the five male and one female patient was 10.8 years (median: 13 years). Particular clinical findings included the location of the tumours; three were found in the pelvis, two in the head and neck, and one in the hand. Four patients are living without disease, and one patient died of disease three years after diagnosis. Histologically, four of the six tumours revealed multinucleated giant cells. Immunohistochemically using a panel of mono- and polyclonal antibodies all cases stained positively for vimentin, cytokeratin, epithelial membrane antigen (EMA), and human milk fat globulin (HMFG-2). Five cases were positive for neuron specific enolase (NSE), and three stained positively for protein S-100. A positive reaction for alpha-1-antichymotrypsin was noted in two cases. These immunohistochemical findings attest to the multidirectional differentiating capabilities of epithelioid sarcoma and support the concept of derivation from a multipotent mesenchymal stem cell.
Each cell lineage specified in the preimplantation mammalian embryo depends on intrinsic factors for its development, but there is also mutual interdependence between them. OCT4 is required for the ICM/epiblast lineage, and at transient high levels for extraembryonic endoderm, but also indirectly through its role in regulating Fgf4 expression, for the establishment and proliferation of extraembryonic ectoderm from polar trophectoderm. The transcription factor SOX2 has also been implicated in the regulation of Fgf4 expression. We have used gene targeting to inactivate Sox2, examining the phenotypic consequences in mutant embryos and in chimeras in which the epiblast is rescued with wild-type ES cells. We find a cell-autonomous requirement for the gene in both epiblast and extraembryonic ectoderm, the multipotent precursors of all embryonic and trophoblast cell types, respectively. However, an earlier role within the ICM may be masked by the persistence of maternal protein, whereas the lack of SOX2 only becomes critical in the chorion after 7.5 days postcoitum. Our data suggest that maternal components could be involved in establishing early cell fate decisions and that a combinatorial code, requiring SOX2 and OCT4, specifies the first three lineages present at implantation.
Mesenchymal stem cells (MSCs) have been recently shown to inhibit T-cell proliferation to polyclonal stimuli. We characterized the effect of MSCs of bone marrow origin on the T-cell response of naive and memory T cells to their cognate antigenic epitopes. The immune response to murine male transplantation antigens, HY, was selected because the peptide identity and major histocompatibility complex (MHC) restriction of the immunodominant epitopes are known. C57BL/6 female mice immunized with male cells were the source of memory T cells, whereas C6 mice transgenic for HY-specific T-cell receptor provided naive T cells. Responder cells were stimulated in vitro with male spleen cells or HY peptides in the presence or absence of MSCs. MSCs inhibited HY-specific naive and memory T cells in a dose-dependent fashion and affected cell proliferation, cytotoxicity, and the number of interferon gamma (IFN-gamma)-producing HY peptide-specific T cells. However, the MSC inhibitory effect did not selectively target antigen-reactive T cells. When MSCs were added to the T-cell cultures in a Transwell system or MSCs were replaced by MSC culture supernatant, the inhibitory activity was abrogated. T-cell reactivity was also restored if MSCs were removed from the cultures. The expression of MHC molecules and the presence in culture of antigen-presenting cells (APCs) or of CD4(+)/CD25(+) regulatory T cells were not required for MSCs to inhibit. We conclude that MSCs inhibit naive and memory T-cell responses to their cognate antigens. Overall our data suggest that MSCs physically hinder T cells from the contact with APCs in a noncognate fashion.
We investigated the effect of thrombopoietin (TPO) on the growth of leukaemic blasts from 30 acute myelogenous leukaemia (AML) patients according to the surface expression of CD7 and CD34: 10 patients were CD7 positive (CD7+), nine were CD7 negative/CD34+ (CD7-/CD34+) and the remaining 11 were CD7-/CD34-. Significant growth response of leukaemic blasts to TPO was observed in 10/10 CD7+, 5/9 CD7-/CD34+ and 2/11 CD7-/CD34- AML cases using 3H-thymidine incorporation. Synergistic stimulatory effects of TPO with stem cell factor (SCF), interleukin-3 (IL-3), granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor were observed in both TPO-responding cases (9/17) and TPO-non-responding cases (8/13). In a leukaemic blast colony assay. significant growth response to TPO was observed in 5/6 CD7+ and 4/17 CD7-AML cases examined. However, the effect of TPO on the growth of CD7+ leukaemic blasts was not so potent as that of IL-3 and SCF, both of which support the proliferation of primitive haemopoietic progenitors. Expression of c-mpl (TPO receptor) was significantly higher in CD7+ AML cases than in CD7- cases, suggesting a relationship between expression of c-mpl and proliferative response to TPO. These data indicate that CD7+ leukaemic blasts express functional TPO receptors and proliferate in response to TPO. These observations also imply that CD7 expression on AML blasts may indicate involvement of leukaemic progenitors at an early stage of multipotent haemopoietic stem cells.
An infant case of acute leukemia (AL) showed lineage infidelity and a chromosome rearrangement involving 11q23. This case was morphologically diagnosed as ALL-L2 according to the FAB classification. However, the blast cells were highly positive for monoclonal antimyeloid antigens (Mol and TG-8) and lymphoid markers (B1, J5 and TdT). These immunologic findings indicated that the blast cells had characteristics of lymphoid B-cell and myeloid lines. In the literature, so-called "11q23 chromosome abnormalities," commonly observed in acute nonlymphoblastic leukemia (ANLL) and in a subtype of acute lymphoblastic leukemia (ALL) with t(4;11) were observed in both lymphoid and myeloid acute leukemias, with some of them recently reported to have lineage infidelity. These unique characteristics may indicate the possibility that the latter is a variation of the former, and support the hypothesis that the chromosomal rearrangement at 11q23 occurs at a multipotent stem-cell level.
Within the contemporary multitude of complex methods used in clinical flow cytometry, very few techniques exist which can be described as disease-specific diagnostic tests. Detection of glycophosphatidylinositol (GPI)-linked antigens on hematopoietic cells using monoclonal antibodies and flow cytometry forms the basis of a specific diagnostic test for paroxysmal nocturnal hemoglobinuria (PNH). Absent or markedly diminished expression of GPI-linked antigens is, in the appropriate clinical setting, specific for all patients with PNH. Clinically, PNH is a syndrome characterized by bone marrow failure, acquired hemolytic anemia, and a thrombotic tendency. The molecular genetic lesion responsible for this condition is a somatic mutation of the X-linked pig-a gene within a multipotent hematopoietic stem cell. Due to its rarity, delay in diagnosis is not uncommon for patients with PNH. Once a definitive diagnosis is established, this can make a considerable impact on patient management and prognosis. In this article, we review the complimentary roles that molecular biology and flow cytometry have played in unraveling the genotypic and phenotypic aspects of this unique condition.
We have previously identified multipotent neuroepithelial (NEP) stem cells and lineage-restricted, self-renewing precursor cells termed NRPs (neuron-restricted precursors) and GRPs (glial-restricted precursors) present in the developing rat spinal cord (A. Kalyani, K. Hobson, and M. S. Rao, 1997, Dev. Biol. 186, 202-223; M. S. Rao and M. Mayer-Proschel, 1997, Dev. Biol. 188, 48-63; M. Mayer-Proschel, A. J. Kalyani, T. Mujtaba, and M. S. Rao, 1997, Neuron 19, 773-785). We now show that cells identical to rat NEPs, NRPs, and GRPs are present in mouse neural tubes and that immunoselection against cell surface markers E-NCAM and A2B5 can be used to isolate NRPs and GRPs, respectively. Restricted precursors similar to NRPs and GRPs can also be isolated from mouse embryonic stem cells (ES cells). ES cell-derived NRPs are E-NCAM immunoreactive, undergo self-renewal in defined medium, and differentiate into multiple neuronal phenotypes in mass culture. ES cells also generate A2B5-immunoreactive cells that are similar to E9 NEP-cell-derived GRPs and can differentiate into oligodendrocytes and astrocytes. Thus, lineage restricted precursors can be generated in vitro from cultured ES cells and these restricted precursors resemble those derived from mouse neural tubes. These results demonstrate the utility of using ES cells as a source of late embryonic precursor cells.
Articular cartilage damaged by disease or trauma has a limited capacity for regeneration. The end stage of cartilage loss frequently leads to osteoarthritis resulting in a significantly decreased quality of life in millions of people. The surgical treatment of articular cartilage injury has always posed difficult problems for orthopedic surgeons and regarding long-term outcomes the currently available methods are unsatisfactory. The main lack of the applied methods is the appearance of the mechanically inadequate resident fibrocartilage instead of hyalin cartilage in the place of the cartilage defect. To find reliable methods for early repair of cartilage injuries seems of huge importance. Using techniques of tissue engineering, artificial cartilage fabricated in vitro has been applied for the repair and regeneration of damaged cartilage. Mesenchymal stem cells provide a source of cells for the repair of musculoskeletal tissue. Mesenchymal stem cells are multipotent cells that are capable of differentiating into cartilage, tendon, muscle, cartilage or hematopoiesis supporting marrow stroma. To ensure the successful durable integration and function of the engineered tissue requires suitable biomechanical and biochemical circumstances, and poses the challenge of handling in vitro culture of human cells, cell biology and molecular biology.
The aims of neurology in Japan in the 21st Century should include establishment of therapeutic measures for neurological diseases, training clinical neurologists to cover both static and dynamic aspects of neurology, and application of gene therapy and neurogenesis to clinical neurology. It is also important to note that once any neurological disease develops, remaining sequelae are usually not curable, so the problem of how to prevent the onset of neurological diseases, that is preventive neurology, will become increasingly important. The key target for prevention in neurology is cerebro-vascular disease, since it is very common. Many risk factors are known for ischemic CVD. However, even for the management of hypertension, the so-called number needed to treat (NNT) is 29-118/5 years for primary prevention and 14-23/5 years for secondary prevention. It is also important to consider genetic factors that influence CVD, including abnormal plasminogen, Lp (a), ACT Isehara 1 gene, apolipoprotein E and so on, since these congenital factors reinforce known acquired risk factors, such as hypertension. In addition, the presence of asymptomatic cerebral infarction, as well as PVH and DSWMH, in MRI T2-weighted images is an important predictor of future symptomatic CVD. Finally, storage of one's own bone marrow cells might be useful, since in the event of onset of CVD, dementia or other neurological diseases, autotransplantation with cytokine might become available for neurogenesis. The results of our recent experiments indicate that this idea may be feasible.
Thrombocytopenia is common in sick preterm babies. Despite this, platelet production in thrombocytopenic preterm babies has rarely been assessed. To address this problem we have developed miniaturized assays to study circulating megakaryocyte (MK) progenitors [burst-forming unit (BFU)-MK and colony-forming unit (CFU)-MK], total cultured MK precursors and mature MK, by culturing mononuclear cells purified from 0.5-1 mL of preterm peripheral blood. MK lineage colonies and cells are identified by an anti-IIb/IIIa antibody (CD61). We prospectively studied circulating BFU-MK/CFU-MK, total cultured MK precursors and mature MK in 63 preterm babies (gestational age 24-34 wk). Twenty-six developed early thrombocytopenia (platelets < 150 x 10(9)/L by 48 h), whereas the remaining 37 babies maintained normal platelet counts. Twenty-one of the 26 thrombocytopenic babies were born to mothers with pregnancy-induced hypertension or were growth retarded. At birth, thrombocytopenic babies had severely reduced numbers of all MK precursors compared with nonthrombocytopenic babies: BFU-MK 82 +/- 50 versus 663 +/- 174 colonies/mL, mean +/- SEM; CFU-MK 596 +/- 196 versus 3267 +/- 530 colonies/mL; total MK precursors 97 +/- 30 versus 301 +/- 49 x 10(3) cells/mL and mature MK 8 +/- 2 versus 37 +/- 8 x 10(3) cells/mL, respectively. Thrombocytopenia resolved by d 10 in all babies accompanied or preceded by a recovery to normal numbers of circulating MK progenitors. Eighteen (69%) of the thrombocytopenic babies were also neutropenic (neutrophils < 2 x 10(9)/L); in these babies neutrophil progenitor cells (CFU-granulocyte/monocyte) were also severely reduced compared with the nonthrombocytopenic babies (539 +/- 280 versus 1937 +/- 348 colonies/mL, mean +/- SEM). This indicates that the principal cause of the thrombocytopenia and neutropenia is reduced platelet and neutrophil production occurring as a consequence of reduced numbers of MK and CFU-granulocyte/monocyte progenitors, respectively. Taken together these data suggest the hematologic abnormalities characteristic of newborns born to mothers with pregnancy-induced hypertension or with intrauterine growth retardation are a consequence of dysregulation of fetal hemopoiesis occurring proximal to committed MK and neutrophil progenitors, most likely at the level of the primitive multipotent hemopoietic stem cell.
Mesenchymal stem cells were isolated and a subpopulation of cells--multipotent adult progenitor cells--were identified that have the potential for multilineage differentiation. Their ability to engraft and differentiate in vivo is under investigation.
Embryo experimentation raises many ethical questions, but is established as acceptable practice in the UK under the Human Fertilisation and Embryology Act 1990. The development of preimplantation genetic diagnosis (PGD) and embryonic stem (ES) cell research is dependent on couples undergoing in vitro fertilization (IVF) donating for research embryos that are unused in, or unsuitable for, treatment. Rarely is the role of these donors acknowledged, let alone studied. One concern is whether couples feel an obligation to donate embryos because of their gratitude for the IVF treatment they have received. This article, based on an ongoing study investigating the similarities and differences between the views and values of those IVF couples who agree to donate embryos for research and those who refuse to donate embryos, explores the broader issues around embryonic research. Discussions such as this, embedded in a background of empirical research, will assist practitioners and policymakers in assessing the social and ethical contexts of this very important aspect of current and future scientific developments.
Pancreatic lymphangiomas, which occur predominantly in women, are rare and account for only 1% of all lymphangiomas. The characteristic histologic features include multiple cysts lined by endothelial cells, irregularly distributed smooth muscle cells, and lymphoid aggregates in the wall of the cyst. We describe a 36-year-old woman with lymphangioma of the pancreas with "ovarian-like" mesenchymal stroma in the wall. This stroma, composed of uncommitted mesenchymal cells, has not been described previously in the wall of pancreatic lymphangiomas. Multiple small lymphatic channels that are found in this stroma recapitulate the development of lymphatic channels in the embryo. Lymphangioma of the pancreas may arise from distension of these lymphatic channels. Pancreatic lymphangioma may, therefore, be a developmental anomaly rather than a true neoplasm.
OBJECTIVE: Severe newborn hypoxic-ischemic encephalopathy (HIE) has a very high rate of disability and no effective treatment is available. The present study aimed to preliminarily evaluate the effects of human neural stem cell transplantation in treatment of severe neonatal HIE. METHODS: The patient was a 75-day old male infant with sequelae of severe HIE who had highly delayed development of intelligence and movement and myotonia. MRI showed multiple cerebromalacia and encephalatrophy. Cells obtained from the forebrain of an 11-week old fetus were cultured and amplified for 15 days. And then the human fetal neural stem cells were injected into cerebral ventricle of this infant. RESULTS: Twenty eight days after transplantation, remarkable improvement occurred not only in his myotonia but also in his intelligence and movement, which became similar to those of the normal infants of the same age. Positron emission tomography (PET) showed significantly increased radioactivity at temporal and occipital lobes which suggested that the cellular metabolism had increased greatly. CONCLUSION: The short-term effect of NSCs transplantation on the infant with severe HIE sequelae was significant. PET suggested that the implanted NSCs survived. Many more studies are needed to evaluate long-term effects of NSC transplantation in treatment of HIE.
Human neural stem cells (HNSCs) are used in studies of neural development and differentiation, and are regarded as an alternative source of tissue for neural transplantation in degenerative diseases. Selection and standardization of HNSC samples is an important task in research and clinical approaches. We evaluated embryonal brain matter obtained from human 8-12-week-old fetuses by means of flow cytometry on a panel including: nestin; vimentin; NeuN; GFAP; beta-tubulin III; CD56; N-Cad; OB-Cad; HLA-ABC; HLA-DR; CD34, and annexin. Samples from embryos of even the same gestation differ dramatically regarding neural cell development, their phenotype and viability. The samples containing the highest proportion of stem cells and multipotent progenitors of neural types, and the least of definitive cells and antigens of histocompatibility, were selected for further expansion in serum-free medium. Secondary phenotyping 14 days later revealed again a marked heterogeneity of the cultures. For the final culturing for 24 h in a serum-containing medium we selected only samples having following phenotype: nestin+, and vimentin+ no less than 25%; HLA-DR+ and CD34+ no more than 5%; GFAP+ no more than 10%; beta-tubulin+ no more than 20%; CD56+, N-Cad+, OB-Cad+, HLA-A,B,C+, and annexin+ no more than 15%; cell viability no less than 60%. Immunocytochemical study of selected samples proved that numerous neural stem cells, and neuro- and glioblasts necessary for transplantation were present. Our results demonstrate that the flow cytometry phenotyping allows the screening and standardization of HNSC samples for further expansion and transplantation.
The glucose-6-phosphate dehydrogenase (G.-6-P.D.) types of isolated blood-cell populations and normal skin were determined in two patients with chronic lymphocytic leukaemia (C.L.L.) who were heterozygous at the G.-6-P.D. locus. Normal tissues from each patient manifested both A and B G.-6-P.D. types, but the C.L.L. B-lymphocyte preparation from one patient showed only a single enzyme type, and from the other patient it showed 95% activity of one G.-6-P.D. type. These observations confirm the supposition based on immunoglobulin-marker data that at the time of study C.L.L. has a clonal origin. In contrast to the B lymphocytes, granulocytes, erythrocytes, platelets, and T lymphocytes displayed both enzyme types in proportions similar to those found in skin. These findings indicate that C.L.L. involves committed B-lymphocyte progenitors. Thus, the disease stands in contrast to chronic myelocytic leukaemia and other myeloproliferative syndromes, all of which involve multipotent haemopoietic stem cells.
The physical and biological properties of murine splenic granulocyte-macrophage colony-forming cells (GM-CFC) were analyzed after the injection of the splenic hemopoiesis stimulating agent lipid A. In continuous gradients of Percoll, the majority of the splenic GM-CFC of untreated mice peaked at a buoyant density of 1.090 g/cm3, while a small second GM-CFC peak could be detected at 1.065 g/cm3. One day after the injection of lipid A, the splenic GM-CFC were almost equally distributed among these two density peaks. This altered proportion was still detectable 72 to 96 h later, although to a smaller extent. No difference in the responsiveness to the colony-stimulating factor (GM-CSF) from mouse-lung conditioned medium (MLCM) was observed between these two density subpopulations. The differentiation pattern of splenic GM-CFC was altered after the injection of lipid A. However, this altered pattern was the same in both density subpopulations. The percentage of splenic GM-CFC as well as the percentage of multipotent hemopoietic stem cells (CFUs) in DNA synthesis were markedly elevated after the injection of lipid A. A striking difference in the proliferative activity was found between high- and low-density GM-CFC in post-lipid A spleens. 24 h after the injection of lipid A, 43% of the high-density GM-CFC subpopulation was found in S according to the suicide technique using tritiated thymidine, whereas in the low-density fraction only 10% of the population was killed. This finding allows alternative interpretations.