• Clinical and Experimental Pediatrics
• /
• v.50 no.6
• /
• pp.519-523
• /
• 2007

Aplastic anemia is a rare disease, which is characterized by pancytopenia and hypocellular bone marrow without infiltration of abnormal cells or fibrosis. The incidence in Asia is higher than in the West and new cases are diagnosed at a rate of 5.1 per million pediatric populations per year in Korea. The pathophysiology is understood roughly by defective hematopoiesis, impaired bone marrow micro-environment and immune mechanism. Treatments are performed on basis of pathogenesis and selected depending on the severity. Immunosuppressive therapy with antilymphocyte or antithymocyte globulin and cyclosporine is effective in the majority of patients but has some problems including relapse or clonal evolution. Recently, there have been clinical trials of immunosuppression with hematopoietic growth factors or other drugs. Allogeneic hematopoietic stem cell transplantation (HSCT) is curative in children with severe aplastic anemia. The overall survival in HSCT from HLA-identical sibling is higher than alternative donor, including HLA matched unrelated donor or cord blood. We have to consider quality of life after HSCT because of high survival rate. However, chronic graft versus host disease and graft failure are important factors that affect the quality of life and overall survival. We need further investigation to make new regimens aimed at overcoming these risk factors and perform clinical trials.

• Clinical and Experimental Pediatrics
• /
• v.54 no.3
• /
• pp.106-110
• /
• 2011

In pediatric patients with acute lymphoblastic leukemia (ALL), the Philadelphia chromosome translocation is uncommon, with a frequency of less than 5%. However, it is classified as a high or very high risk, and only 20-30% of Philadelphia chromosome-positive (Ph+) children with ALL are cured with chemotherapy alone. Allogeneic hematopoietic stem cell transplantation from a closely matched donor cures 60% of patients in first complete remission. Recent data suggest that chemotherapy plus tyrosine kinase inhibitors (TKIs) may be the initial treatment of choice for Ph+ ALL in children. However, longer observation is required to determine whether long-term outcome with intensive imatinib and chemotherapy is indeed equivalent to that with allogeneic related or alternative donor hematopoietic stem cell transplantation (HSCT). Reports on the use of second-generation TKIs in children with Ph+ ALL are limited. A few case reports have indicated the feasibility and clinical benefit of using dasatinib as salvage therapy enabling HSCT. However, more extensive data from clinical trials are needed to determine whether the administration of second-generation TKIs in children is comparable to that in adults. Because Ph+ ALL is rare in children, the question of whether HSCT could be a dispensable part of their therapy may not be answered for some time. An international multicenter study is needed to answer the question of whether imatinib plus chemotherapy could replace sibling allogeneic HSCT in children with Ph+ ALL.

• Journal of Veterinary Clinics
• /
• v.32 no.4
• /
• pp.352-355
• /
• 2015

This study was conducted to ascertain whether the scent detection ability of a donor dog having extraordinary talent in cancer detection can be conserved through cloning. A specially trained dog for colorectal cancer detection was cloned, and she was trained and tested to detect breast cancers using breath samples collected from patients and healthy volunteers. Scent detection sensitivity of the clone was 93.3% and specificity was 99.5%, similar with those of donor (91% and 99%). Furthermore, the clone successfully detected early stage of breast cancers. Therefore, superior canine scent detection ability for cancer screening could be preserved through cloning.

• Reproductive and Developmental Biology
• /
• v.31 no.2
• /
• pp.127-131
• /
• 2007

Embryonic germ (EG) cells are undifferentiated stern cells isolated from cultured primordial germ cells (PGC). These cells share many characteristics with embryonic stem cells including morphology and pluripotency. Undifferentiated porcine EG cell lines demonstrating capacities of differentiation both in vitro and in vivo have been established. Since EG cells can be cultured indefinitely in an undifferentiated state, whereas somatic cells in primary culture are often unstable and have limited lifespan, EG cells may provide inexhaustible source of karyoplasts in nuclear transfer (NT). In this study the efficiencies of NT using porcine EG and fetal fibroblast cells were compared. Two different techniques were used to perform NT. With conventional NT procedure (Roslin method) involving fusion of donor cells with enucleated oocytes, the rates of development to the blastocyst stage in EG and somatic cell NT were 16.8% (59/351) and 14.5% (98/677), respectively. In piezo-driven microinjection (Honolulu method) of donor nuclei into enucleated oocytes, the rates of blastocyst formation in EG and somatic cell NT were 11.9% (15/126) and 9.4% (9/96), respectively. Regardless of NT methods used in this study, EG cell NT gave rise to comparable rate of blastocyst development to somatic cell NT. Overall, EG cells can be used as karyoplast donor in NT procedure, and embryos can be produced by EG cell NT that may be used as an alternative to conventional somatic cell NT.

• Fisheries and Aquatic Sciences
• /
• v.19 no.4
• /
• pp.16.1-16.8
• /
• 2016

To culture germline stem cells in vitro, establishment of the cell lines that can be used as the feeder cells is a prerequisite. In this study, we tried to establish gonad-derived cell lines in Siberian sturgeon (Acipenser baerii). Five 1-year-old A. baerii were used as a donor of gonad tissues, and gonad-dissociated cells were cultured in vitro. Subsequently, determination of growth conditions, long-term culture, characterization, and cryopreservation of the cell lines were also conducted. Five gonad-derived cell lines were stably established and cultured continuously over at least the 73th passage and 402 culture days under the media containing 20 % fetal bovine serum at $28^{\circ}C$. All cell lines consisted of two main cell types based on morphology even if the ratio of the two cell types was different depending on cell lines. Despite long-term culture, all cell lines maintained diploid DNA contents and expression of several genes that are known to express in the A. baerii gonad. After freezing and thawing of the cell lines, post-thaw cell viabilities between 57.6 and 92.9 % depending on cell lines were indentified, suggesting that stable cryopreservation is possible. The results and the cell lines established in this study will contribute to the development of an in vitro system for A. baerii germline stem cell culture.

• International Journal of Stem Cells
• /
• v.16 no.1
• /
• pp.36-43
• /
• 2023

Background and Objectives: Lymphoblastoid cell lines (LCLs) deposited from disease-affected individuals could be a valuable donor cell source for generating disease-specific induced pluripotent stem cells (iPSCs). However, generation of iPSCs from the LCLs is still challenging, as yet no effective gene delivery strategy has been developed. Methods and Results: Here, we reveal an effective gene delivery method specifically for LCLs. We found that LCLs appear to be refractory toward retroviral and lentiviral transduction. Consequently, lentiviral and retroviral transduction of OCT4, SOX2, KFL4 and c-MYC into LCLs does not elicit iPSC colony formation. Interestingly, however we found that transfection of oriP/EBNA-1-based episomal vectors by electroporation is an efficient gene delivery system into LCLs, enabling iPSC generation from LCLs. These iPSCs expressed pluripotency makers (OCT4, NANOG, SSEA4, SALL4) and could form embryoid bodies. Conclusions: Our data show that electroporation is an effective gene delivery method with which LCLs can be efficiently reprogrammed into iPSCs.

• Journal of Chest Surgery
• /
• v.29 no.7
• /
• pp.713-722
• /
• 1996

Poor long term patient survival (60% at 2 years) in lung allograft recipients are mainly due to rejection and complications associated with the use of nonspecific immunosuppressants. Better means to achieve waft acceptance is desperately needed. 1 have investigated whether mixed allogeneic chimerism in the form of bone marrow stem cell engraftment would induce donor-specific tolerance for lung allografts. Fisher (F344) and Wistar Forth (WF)rats were lethally irradiated (1100c0y) and reconstituted with a mixture of T-cell depleted syngeneic and allogeneic bone marrow (F344+WFIWF, ACI +F344- F344). After Mixed chimerism was documented by peripheral blood Ipnphocyte typing at 28 days, orthotopic left single lung transplantation was performed, using donor-s ecific or third party allografts. No immunosuppressants were administered. Graft rejection was monitored by chest rentgenography, and con- firmed by histology Mixed chimeric rats accepted lung allografts permanently, and it was not strain specific effect. Tolerance was all or none phenomenon which had nothing to do with the percentage of chimerlsm. Mixed chimeras rejected third party allografts in less than 10 days, a time course similar to that of unmanipulated controls. No acute or chronic rejection was observed in donor specific grafts more than 150 days posttransplant. These data suggest that mixed chimerism in the form of bone marrow stem cell engraftment results in stable, systemic donor-specific transplantation tolerance for lung allografts.

• Clinical and Experimental Reproductive Medicine
• /
• v.48 no.3
• /
• pp.268-272
• /
• 2021

Bone marrow-derived cell (BMDC) therapy has numerous applications as potential biological cells for use in regenerative medicine. Here, we present an original case of endometrial atrophy associated with genital tuberculosis in a woman who achieved a live birth with BMDC. This 27-year-old woman came to our center with endometrial atrophy and primary infertility. She had a past history of genital tuberculosis and amenorrhea. Her husband's semen quality was normal. The patient was counseled for hysteroscopy due to thin endometrium and advised in vitro fertilization (IVF) with donor eggs in lieu of poor ovarian reserve. Several attempts of IVF with hormone replacement therapy (HRT) were made, but the desired thickness of the endometrium was not achieved. Uterine artery injection of BMDC through interventional radiology was given, followed by HRT for three months, which resulted in improved endometrium. This was subsequently followed by IVF with donor egg. The treatment resulted in the conception and delivery of a 3.1-kg baby boy through lower segment caesarean section with no antenatal, intranatal or postnatal complications. Recently, there has been massive interest in stem cells as a novel treatment method for regenerative medicine, and more specifically for the regeneration of human endometrium disorders like Asherman syndrome and thin endometrium, which was the reason behind using this strategy for treatment.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.6
• /
• pp.423-428
• /
• 2000

In 1997 when cloned sheep Dolly and soon after Polly were born, it had become head-line news because in the former the nucleus that gave rise to the lamb came from cells of six-year-old adult sheep and in the latter case a foreign gene was inserted into the donor nucleus to make the cloned sheep produce human protein, factor IX, in e milk. In the last few years, once the realm of science fiction, cloned mammals especially in livestock have become almost commonplace. What the press accounts often fail to convey, however, is that behind every success lie hundreds of failures. Many of the nuclear-transferred egg cells fail to undergo normal cell divisions. Even when an embryo does successfully implant in the womb, pregnancy often ends in miscarriage. A significant fraction of the animals that are born die shortly after birth and some of those that survived have serious developmental abnormalities. Efficiency remains at less than one % out of some hundred attempts to clone an animal. These facts show that something is fundamentally wrong and enormous hurdles must be overcome before cloning becomes practical. Cloning researchers now tent to put aside their effort to create live animals in order to probe the fundamental questions on cell biology including stem cells, the questions of whether the hereditary material in the nucleus of each cell remains intact throughout development, and how transferred nucleus is reprogrammed exactly like the zygotic nucleus. Stem cells are defined as those cells which can divide to produce a daughter cell like themselves (self-renewal) as well as a daughter cell that will give rise to specific differentiated cells (cell-differentiation). Multicellular organisms are formed from a single totipotent stem cell commonly called fertilized egg or zygote. As this cell and its progeny undergo cell divisions the potency of the stem cells in each tissue and organ become gradually restricted in the order of totipotent, pluripotent, and multipotent. The differentiation potential of multipotent stem cells in each tissue has been thought to be limited to cell lineages present in the organ from which they were derived. Recent studies, however, revealed that multipotent stem cells derived from adult tissues have much wider differentiation potential than was previously thought. These cells can differentiate into developmentally unrelated cell types, such as nerve stem cell into blood cells or muscle stem cell into brain cells. Neural stem cells isolated from the adult forebrain were recently shown to be capable of repopulating the hematopoietic system and produce blood cells in irradiated condition. In plants although the term$\boxDr$ stem cell$\boxUl$is not used, some cells in the second layer of tunica at the apical meristem of shoot, some nucellar cells surrounding the embryo sac, and initial cells of adventive buds are considered to be equivalent to the totipotent stem cells of mammals. The telomere ends of linear eukaryotic chromosomes cannot be replicated because the RNA primer at the end of a completed lagging strand cannot be replaced with DNA, causing 5' end gap. A chromosome would be shortened by the length of RNA primer with every cycle of DNA replication and cell division. Essential genes located near the ends of chromosomes would inevitably be deleted by end-shortening, thereby killing the descendants of the original cells. Telomeric DNA has an unusual sequence consisting of up to 1,000 or more tandem repeat of a simple sequence. For example, chromosome of mammal including human has the repeating telomeric sequence of TTAGGG and that of higher plant is TTTAGGG. This non-genic tandem repeat prevents the death of cell despite the continued shortening of chromosome length. In contrast with the somatic cells germ line cells have the mechanism to fill-up the 5' end gap of telomere, thus maintaining the original length of chromosome. Cem line cells exhibit active enzyme telomerase which functions to maintain the stable length of telomere. Some of the cloned animals are reported prematurely getting old. It has to be ascertained whether the multipotent stem cells in the tissues of adult mammals have the original telomeres or shortened telomeres.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.5
• /
• pp.648-656
• /
• 2008

The objective of this study was to establish conditions for transfection of a foreign gene into somatic cells using cationic lipid reagents and to evaluate the effects of transfection on in vitro development of somatic cell nuclear transfer (SCNT) embryos. Green fluorescent protein (GFP) gene was used as a foreign gene and a non-transfected somatic cell was utilized as a control karyoplast. Monolayers of porcine cells were established and subsequently transfected with a GFP-expressing gene (pEGFP-N1) using three types of transfection reagents (LipofectAMINE PLUS, FuGENE 6 or ExGen500). Donor cells used for SCNT included transfected fetal or adult fibroblasts and oviduct epithelial cells, either serum-fed or serum-starved. Oocytes matured in vitro for 42 h were reconstructed with either transfected or non-transfected porcine somatic cells by electric fusion and activation using a single DC pulse of 1.8 kV/cm for $30{\mu}s$ in $Ca^{2+}$ and $Mg^{2+}-containing$ 0.26 M mannitol solution. Reconstructed oocytes were subsequently cultured in NCSU-23 medium for 168 h and the developmental competence and cell number in blastocyst were compared. There were no significant differences (P>0.05) in fusion, cleavage rates or development to the blastocyst stage between non-transfected, transfected, serum-fed and serum-starved cells. However, the rates of GFP-expressing blastocysts were higher in the FuGENE 6 group (71.4%) among transfection reagents and in the fetal fibroblasts group (70.4%) for donor cells. These results indicate that fetal fibroblasts transfected with FuGENE 6 can be used as donor cells for porcine SCNT and that GFP gene can be safely used as a marker of foreign genes in porcine transgenesis.