• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제31권1호
• /
• pp.31-38
• /
• 2005

Thorough screening of donors medical and social history, extensive serological and bacterial screening combined with developed processing and sterilization methods have improved the safety of the allogeneic tissues in recent decades. The risk of bacterial infection through allogenic tissue transplantation is one of the major problems facing tissue banks. The purpose study is to report the contamination rate in 358 retrieved tissues obtained strictly aseptic conditions, between 2001 and 2002 in Korea Tissue Bank. Samples from 9 donors(total 13 donors) were used in blood culture, and in 7 donors the blood culture were negative. Of the 358 tissues cultured in their entirety, 186(52%) were initially culture negative and 177(48%) were positive. Organism low pathogenicity were cultures from 20.2% of the tissues. To minimize the bacterial load, donors should be obtain in operating rooms, using aseptic techniques with only a few personnel for procurement. The procurement cultures from donors and retrieved tissues with multiple should be carefully interpreted. Blood cultures should be taken account, since these can help to find contamination not detect swab culture. A prospective cohort study is needed to determine which of the varied processing and sterilization methodologies gives the best quality.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제13권3호
• /
• pp.265-277
• /
• 1991

In this study, the healing changes of the implanted bone and its surrounding tissues were examined on the histopathologic basis following implantation of the freeze - dried and radiation - sterilized allogeneic bone in Rectus abdominicus of the rat. This study was performed to see the tissue recations after implantation of the freeze - dried and radiation - sterilized allogeneic bone and whether osteogenesis or osteo - induction or osteo - conduction is happened. And the results were as follows : 1. The shape of the implanted allogeneic bone of the 1, 2 - week group specimen was similar to that of normal bone in light - microscopic finding and the atrophy of cellular organells was found in trans - mission electron - microscopic finding. 2. The implanted allogeneic bone was surrounded with the dense fibroconnective tissues, and infiltration of the chronic inflammatory cells gradually became increased. 3. Hyaline degeneration was observed in the surrounding tissue at the 3, 4, 6 - week group specimen. 4. Light - microscopically the resorption of implanted bone became prominent after 4 - week group and the necrosis of allogeneic bone implant became severe with loss of cell components in lacuna. 5. Electron - microscopically, the osteoclast - like cells ere fond after, 2 - week group. It is summarized that the osteo - conduction potential of the bone is remained just after implanting the freeze - dried and radiation - sterilized allogeneic bone on Rectus abdominicus of the rat, but gradually it disappeared with the gradual increse of chronic inflammatory reaction and osteoclastic activity. So it is suggested that the antigenicity of the freeze - dried and radiation - sterilized bone is remained and it has little osteo - conductive activity when it is implanted in the muscle.

• Journal of Applied Biological Chemistry
• /
• 제50권4호
• /
• pp.187-195
• /
• 2007

The cord blood serves as a vehicle for the transportation of oxygen and nutrients to the fetus. In the past, the human cord blood has generally been discarded after birth. However, numerous studies have described the regenerative ability of the cord blood cells in various incurable diseases. The umbilical cord blood (UCB)-derived stem cells are obtained through non-invasive methods that are not harmful to both the mother and the fetus. Furthermore, the cord blood stem cells are more immature than the adult stem cells and expand readily in vitro. The mesenchymal stem cells (MSCs) have the capacity to differentiate in vitro into various mesodermal (bone, cartilage, tendon, muscle, and adipose), endodermal (hepatocyte), and ectodermal (neurons) tissues. This review describes the immunological properties of the human UCB-MSCs to assess their potential usefulness in the allogeneic transplantation for the regenerative medicine.

• Archives of Plastic Surgery
• /
• 제37권4호
• /
• pp.323-328
• /
• 2010

Purpose: Adipose-derived stromal cells (ADSCs) are multipotent cells that have been found to promote wound healing through the process of angiogenesis and reepithelialization. Generally, it is well known that the antigenicity of ADSCs doesn't affect stem cell therapy. In this study, we investigated the effect of allogeneic ADSCs in the wound healing process by applying allogeneic ADSCs on the wound healing splint model of mice. Methods: Adipose tissue was harvested from the epididymal fat pads of BALB/c and C57BL/6 mice. Twenty four mice BALB/c were divided into three groups; control, isogeneic, and allogeneic groups. Two full thickness defects with 6 mm diameters were created on the back of BALB/c mice. $1{\times}10^6$ ADSCs from BALB/c mice were applied on the isogeneic group. In the allogeneic group, ADSCs from the C57BL/6 mice were applied. No cells were applied to the control group. The sizes of the wounds were evaluated in 3, 5, 7, 10, and 14 days after the wounds were applied, and tissues were harvested in 7 and 14 days for histological analysis. Results: Wound healing rates had showed significant increase in 10, and 14 days when the isogeneic group was compared to the control group, but the allogeneic group showed significantly decrease compared to the isogeneic group (p<0.05). Histological scores in the isogeneic group were significantly high, but significantly lower in the allogeneic group when compared to the isogeneic group in 2 weeks (p<0.05). In the isogeneic group, thick inflammatory cell infiltration with abundant capillaries were observed in 1 week, and thick epithelium with many large capillaries were observed in 2 weeks. Conclusion: When isogeneic ADSCs were applied to wounds, they presented a faster wound healing rate compared to controls and the allogeneic group. Unlike general stem cell therapy, these findings suggest that cell therapy targeted at enhancing wound healing may benefit from the use of ADSCs with identical antigenicity, as opposed to allogeneic or xenogenic ADSCs.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제27권6호
• /
• pp.523-527
• /
• 2005

Allograft donations are commonly found to be contaminated. The most of tissue banks has promoted the use of ionizing radiation for the sterilization of biological tissues. The potential for transmission of human infectious diseases and contamination of microorganism has created serious concern for the continued clinical use of hard and soft-tissue allografts. Tissue banks have employed 15-25kGy for sterilization of hard and tendon allografts, which, according to the national standards, approaches the level at which the tissue quality is adversely affected for transplantation. The donations of allogeneic tissues to the Korea Tissue Bank over a 2-year period were reviewed, and the incidence and bacteriology of contamination were detailed. Clinical outcomes were determined for donors who had positive cultures at the time of retrieval and during the processing and they were compared with those of post sterilization. After exposure of the frozen block bone to 25kGy and the processed tissues to 15kGy of gamma irradiation, the authors were able to demonstrate complete inactivation of the bacteria. The aim of this study was to obtain the effects of gamma irradiation and the irradiation dose according to the type of tissue, through conventional microbiologic test without on influence of biocompatibility in allografts. The contamination rate after the final irradiation sterilization is 0% in the processed allografts. This may be due to the fact that the gamma radiation and processing steps are effective to control contamination.

• 한국임상수의학회지
• /
• 제28권4호
• /
• pp.399-402
• /
• 2011

In recent years, the mesenchymal stem cells (MSC) derived from various tissues have been widely tested for developing cell therapies, tissue repair and transplantation. Although there has been much interest in the immunomodulatory properties of MSC and their immunologic reactions following autologous, allogeneic and xenogenic transplantation of MSC in vivo, up to date, the expression of immunogenic markers, such as class I and II human leukocyte antigens (HLA), after differentiation of human umbilical cord blood (hUCB)-derived MSC has been poorly investigated and require extensive in vitro and in vivo testing. In this experiment, the expression of the HLA-ABC and HLA-DR on hUCB-derived MSC have been tested by immunocytochemical staining. The undifferentiated MSC were moderately stained for HLA-ABC but very weakly for HLA-DR. In order to investigate the inhibitory effect of allogeneic lymphocytes on proliferation of MSC, the MSC were cultured in the presence or absence of peripheral allogeneic lymphocytes stimulated with concanavalin A. The allogeneic lymphocytes did not significantly inhibit MSC proliferation. We conclude that hUCB-MSC expressed moderately class I HLA antigen while almost negatively class II HLA antigen. The MSC have an immunomodulatory effect which can suppress the allogeneic response of lymphocytes. These in vitro data suggest that allogeneic MSC derived from cord blood can be useful candidate for allogeneic cell therapy and transplantation without a major risk of rejection.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제13권2호
• /
• pp.203-216
• /
• 1991

Nerve allografts as a bridge of regeneration is useful in the repair of peripheral nerve defect resulting from trauma, and leprosy. But immunological rejection and complicated scar formation is an unavoidable problem in the application of allogeneic nerves. This article is intended to study of the regeneration of allogeneic nerve grafts in rats with histopathologically, scanning electron microscopically. 24 adult male Sprague-Dawley rats were used as the experimental animals. A 2cm skin incision was made on the lateral aspects of limb, parallel to femur. Segments of sciatic nerve trunk taken from rats, 10mm was resected at the middle of the thigh, nerve graft was inserted between the ends of gaps with perineural and epineural suture method with 10-0 prolene. Obsrevation was made simultaneously at 3 day, 1, 2, 3, 4, 5, 6, 8 weeks after surgery. The results were as follows. 1. In light and electronic microscopic studies, marked degenerative change of the graft nerves were observed at 2 weeks after surgery. 2. After surgery, blood clot fromation was observed at 3 day, granualtion tissue formation was observed at 2 week, and fibrous tissue proliferation was observed at 3 week. 3. In change of nerve fiber, there were Wallerian degeneration at early stage, decrease in degeneration at 4 week but degeneration of myeline was continuded at 8 week. 4. At 4 week, schwann cells proliferate at its cut ends to join with the distal and proximal stump of the damaged nerve. 5. Fibrous scar tissues are formed at 2 weeks and increased progressively in 8 weeks, which was interrupted the regeneration of grafted nerve.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권10호
• /
• pp.5705-5711
• /
• 2013

Background: Embryonic stem cells (ESCs) have the potential to form teratomas when implanted into immunodeficient mice, but data in immunocompetent mice are limited. We therefore investigated teratoma formation after implantation of three different mouse ESC (mESC) lines into immunocompetent mice. Materials and Methods: BALB/c mice were injected with three highly germline competent mESCs (129Sv, BALB/c and C57BL/6) subcutaneously or under the kidney capsule. After 4 weeks, mice were euthanized and examined histologically for teratoma development. The incidence, size and composition of teratomas were compared using Pearson Chi-square, t-test for dependent variables, one-way analysis of variance and the nonparametric Kruskal-Wallis analysis of variance and median test. Results: Teratomas developed from all three cell lines. The incidence of formation was significantly higher under the kidney capsule compared to subcutaneous site and occurred in both allogeneic and syngeneic mice. Overall, the size of teratoma was largest with the 129Sv cell line and under the kidney capsule. Diverse embryonic stem cell-derived tissues, belonging to the three embryonic germ layers, were encountered, reflecting the pluripotency of embryonic stem cells. Most commonly represented tissues were nervous tissue, keratinizing stratified squamous epithelium (ectoderm), smooth muscle, striated muscle, cartilage, bone (mesoderm), and glandular tissue in the form of gut- and respiratory-like epithelia (endoderm). Conclusions: ESCs can form teratomas in immunocompetent mice and, therefore, removal of undifferentiated ESC is a pre-requisite for a safe use of ESC in cell-based therapies. In addition the genetic relationship of the origin of the cell lines to the ability to transplant plays a major role.

• Animal cells and systems
• /
• 제2권1호
• /
• pp.107-111
• /
• 1998

Two kinds of humoral factors were observed in 2 orders, 7 families, 10 genera, and 15 different species of Korean ascidians. They are the naturally occuring hemagglutinins and/or hemolysins against human erythrocytes A, B, and 0. All but two species showed aggregative activity, although there were considerable variations in titer. The weak agglutinating and lytic activities were increased in the presence of $Ca^{++}$. Much higher activities of agglutination and/or lysis were shown in the hemolymph than extracts from tissues, and a higher response was shown in adults than in juveniles. No distinct differences from collected locations were observed. The hemolymph of Ciona intestinalis showed a strong hemolytic (cytotoxic) and weak agglutinins capacities. In addition, hemolymph of Styela plicata and Styela clava clava also showed hemoagglutining and hemolytic activities. Botryllus tuberatus had hemagglutining and weak lytic activities. Other species showed only hemagglutining activity. These agglutining activities are probably responsible for carbohydrate recognition in solitary or colonial ascidian. The lytic activity is probably responsible for antibacterial defense and nonfusion reactions between allogeneic colonial ascidians, especially the genus of Botryllus. The occurrences of humoral factors in ascidians were independent of their geographic distributions.

• Journal of Microbiology and Biotechnology
• /
• 제17권6호
• /
• pp.993-1001
• /
• 2007

The technique of serological analysis of antigens by recombinant cDNA expression library (SEREX) uses autologous patient sera as a screening probe to isolate tumor-associated antigens for various tumor types. Isolation of tumor-associated antigens that are specifically reactive with patient sera, but not with normal sera, is important to avoid false-positive and autoimmunogenic antigens for the cancer immunotherapy. Here, we describe a selection methodology to isolate patient sera-specific antigens from a yeast surface-expressed cDNA library constructed from 15 patient lung tissues with non-small cell lung cancer (NSCLC). Several rounds of positive selection using patient sera alone as a screening probe isolated clones exhibiting comparable reactivity with both patient and normal sera. However, the combination of negative selection with allogeneic normal sera to remove antigens reactive with normal sera and subsequent positive selection with patient sera efficiently enriched patient sera-specific antigens. Using the selection methodology described here, we isolated 3 known and 5 unknown proteins, which have not been isolated previously, but and potentially associated with NSCLC.