Clear cell odontogenic carcinoma: a mini review

Clear cell odontogenic carcinoma (CCOC), a very rare neoplasm located mostly in the mandible, has been regarded as a benign tumor. However, due to the accumulation of case reports, CCOC has been reclassified as a malignant entity by the World Health Organization. Patients with CCOC present with regional swelling and periodontal indications with variable pain, often remaining misdiagnosed for a long period. CCOC has slow growth but aggressive behavior, requiring radical resection. Histologic analysis revealed the monophasic, biphasic, and ameloblastic types of CCOC with clear cells and a mixed combination of polygonal and palisading cells. At the molecular level, CCOC shows the expression of cytokeratin and epithelial membrane antigen, along with markers that assign CCOC to the sarcoma family. At the genetic level, Ewing sarcoma breakpoint region 1-activating transcription factor 1 fusion is regarded as the key feature for identification. Nevertheless, the scarcity of cases and dependence on histological data delay the development of an efficient therapy. Regarding the high recurrence rate and the potential of distant metastasis, further characterization of CCOC is necessary for an early and accurate diagnosis.

Differentiation of CD31-Positive Vascular Endothelial Cells from Organoid Culture of Dental Pulp Stem Cells

The mesenchymal stem cells (MSCs) that reside in dental tissues hold a great potential for future applications in regenerative dentistry. In this study, we used human dental pulp cells, isolated from the molars (DPCs), in order to establish the organoid culture. DPCs were established after growing pulp cells in an MSC expansion media (MSC-EM). DPCs were subjected to organoid growth media (OGM) in comparison with human dental pulp stem cells (DPSCs). Inside the extracellular matrix in the OGM, the DPCs and DPSCs readily formed vessel-like structures, which were not observed in the MSC-EM. Immunocytochemistry analysis and flow cytometry analysis showed the elevated expression of CD31 in the DPCs and DPSCs cultured in the OGM. These results suggest endothelial cell-prone differentiation of the DPCs and DPSCs in organoid culture condition.

Trib2 regulates the pluripotency of embryonic stem cells and enhances reprogramming efficiency

Embryonic stem (ES) cells are pluripotent cells characterized by self-renewability and differentiation potential. Induced pluripotent stem (iPS) cells are ES cell-equivalent cells derived from somatic cells by the introduction of core reprogramming factors. ES and iPS cells are important sources for understanding basic biology and for generating therapeutic cells for clinical applications. Tribbles homolog 2 (Trib2) functions as a scaffold in signaling pathways. However, the relevance of Trib2 to the pluripotency of ES and iPS cells is unknown. In the present study, we elucidated the importance of Trib2 in maintaining pluripotency in mouse ES cells and in generating iPS cells from somatic cells through the reprogramming process. Trib2 expression decreased as ES cells differentiated, and Trib2 knockdown in ES cells changed their colony morphology while reducing the activity of alkaline phosphatase and the expression of the pluripotency marker genes Oct4, Sox2, Nanog and Klf4. Trib2 directly interacted with Oct4 and elevated Oct4 promoter activity. During the generation of iPS cells, Trib2 knockdown decreased the reprogramming efficiency of mouse embryonic fibroblasts, whereas Trib2 overexpression significantly increased their reprogramming efficiency. In summary, our results suggest that Trib2 is important for maintaining self-renewal in ES cells and for pluripotency induction during the reprogramming process.

Expression of Cytokines in Coculture Model with Epithelial Cells and Fibroblasts of Nasal Polyp / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Nasal polyposis is a chronic inflammatory disease characterized histologically by edematous fluid with sparse fibrous cells, few mucous glands and proliferation of stromal and epithelial cells. There have been many studies done separately about epithelial cells, fibroblasts, and other inflammatory cells in nasal polyps. However, there is no usable study model for the cell-to-cell interaction. Therefore, we tried to make a new model for the study of nasal polyp by coculture of epithelial cells and fibroblasts. SUBJECTS AND METHOD: Nasal polyp was collected during endoscopic sinus surgery. Almost half of them were used for epithelial cell culture and the remaining portion was used for fibroblast culture in the same polyp. Using a transwell insert, fibroblasts were placed in the bottom and epithelial cells were placed on the insert, respectively. RNA were isolated both from epithelial cells and fibroblasts of 12, 24, and 48 hours' coculture. The expressions of IL-8, IL-6, and eotaxin from cocultured cells were compared with cells that were cultured alone by semiquantitative RT-PCR. RESULTS: IL-8 was highly expressed in fibroblasts than in epithelial cells, especially in cocultured cells. The expression of IL-6 in fibroblasts was much higher than in epithelial cells, especially in cocultured fibroblasts. Eotaxin is weakly expressed in fibroblasts but not in epithelial cells. CONCLUSION: These findings indicate that cocultured cells show different expression of the mRNA of various cytokines compared with cultured cells alone. And this coculture system may be more ideal than the mono-cell culture system for the study of cell-to-cell interactions and to reveal the pathogenesis of nasal polyposis.

Effects of High Glucose on Interleukin-6 Production in Human Mesangial Cells

Interleukin (IL)-6 is an autocrine growth factor for mesangial cells. It is not known whether high glucose influences IL-6 production in mesangial cells. Angiotensin II (AGII) is involved in the progression of renal diseases including diabetic nephropathy. Therefore, we evaluated the effects of high glucose in concert with AGII on IL-6 production in human mesangial cells and the modulation by blocking AGII. After 48 hr of culture, IL-6 mRNA expression was analyzed by reverse transcription and polymerase chain reaction (PCR). Quantitative determination of IL-6 concentrations in the culture supernatants of mesangial cells was performed using a sandwich enzyme immunoassay kit. Incubation of mesangial cells with high glucose (450 mg/dL) reduced the ratio of PCR products for IL-6 to beta-actin on densitometric results, while AGII (10(-7)M) increased it. The IL-6 secretion in the supernatant was also increased by AGII and decreased by high glucose. The IL-6 mRNA expression and IL-6 secretion in combination of high glucose and AGII were higher than those in high glucose and similar with those in control media. The addition of losartan (10(-6)M) or captopril (10(-6)M) to high glucose had no additional effects on IL-6 production. These results suggest that whereas AGII increases IL-6 production, high glucose decreases it. The IL-6 production of mesangial cells in diabetic milieu may be complicated and depend on the local effects of high glucose and/or AGII.

Effects of Immune Aggregates, Hydrocortisone and Angiotensin II Receptor Blocker on Interleukin-6 mRNA Expression in Human Mesangial Cells / 대한신장학회잡지

PURPOSE: Various factors regulate interleukin(IL)-6 expression in mesangial cells (MCs). Immune complexes or angiotensin II(AII) are involved in the development of glomerulonephritis(GN). We evaluated the effects of IgG and IgA aggregates or AII on IL-6 mRNA expression in human MCs and the modulation by losartan, an AT1 receptor blocker, or hydrocortisone. METHODS: After 48 hours of culture in the presence of sera, IL-6 mRNA expression was analyzed by reverse transcription and polymerase chain reaction(PCR). RESULTS: Incubation of MCs with IgA or IgG aggregates(100 microgram/mL) as well as AII(10(-7) M) enhanced the ratio of PCR products for IL-6 to beta-actin on densitometric results. The addition of hydrocortisone(0.5 microgrammL) reduced the IgA aggregates-induced IL-6 mRNA expression and losartan(10(-6) M) reduced IgG aggregates- induced IL-6 mRNA expression. CONCLUSION: These results suggest that IgG and IgA aggregates and AII may induce IL-6 expression in GN which can be partially suppressed by hydrocortisone or AT1 receptor blocker.

Effect of Native and Modified Lipoproteins, and Albumin on Human Mesangial Cell Proliferation / 대한신장학회잡지

BACKGROUND: Modified lipoproteins may be involved in nephro- and glomerulosclerosis. Diabetic nephropathy-like lesions have also been induced in a rat model by glycated and glycoxidized albumin. In cultured rat or human mesangial cells, enhanced cell proliferation and production of mesangial matrix in response to lipoproteins and their modified forms have been demonstrated by [3H]-thymidine incorporation and cell counting assays. But these methods are relatively complex and most of them have used only one or two of the lipoprotein, albumin and their modified forms. METHODS: We investigated the effects of native and modifed lipoproteins, and albumin on cultured human mesangial cell proliferation using non-radioactive colorimetric method by MTS/PMS assay. Lipoproteins added were low density lipoprotein(LDL), high density lipoprotein(HDL), very low density lipoprotein(VLDL), oxidized LDL(oxidation with copper sulfate in vitro) and glycated LDL and we also used albumin, glycated albumin, and interleukin-1beta as a positive control. RESULTS: Interleukin-1beta promoted the proliferation of cultured human mesangial cells up to concentration 20 ng/mL. LDL induced the proliferation of mesangial cells in a concentration-dependent manner up to concentration 100 microgram/mL. HDL and VLDL had no significant proliferative effect. Oxidized LDL caused the proliferation of mesangial cells at low concentration up to concentration 25 microgram/mL. Addition of glycated LDL resulted in a concentration- dependent inhibition of mesangial cells. Albumin and glycated albumin inhibited the proliferation of mesangial cells at low concentration of 100 microgram/mL, but cell growth was increased at higher concentrations. CONCLUSION: We demonstrated the effects of the single and modified proteins on the proliferation of cultured human mesangial cell by relatively simple colorimetric method. Results were almostly identical to those of previous studies obtained by radioactive method or cell counting assay.

Prospective Study of the Immunologic Factors Affecting the Prognosis of Severe Community-Acquired Pneumonia / 결핵

BACKGROUND: In the severe community-acquired pneumonia, it has been known that the immune status is occasionally suppressed. This study was performed to identify the immunologic markers related with the prognostic factors in severe community-acquired pneumonia. METHODS: 23 patients with severe community-acquired pneumonia were involved in this study, and divided into survivor (16) and nonsurvivor (7) groups. In this study, the medical history, laboratory tests(complete blood counts, routine chemistry profile, immunoglobulins, complements, lymphocyte subsets, cytokines, sputum and blood culture, urine analysis), and chest radiographs were scrutinized. RESULTS: 1) Both groups had lymphopenia(total lymphocyte count 995.6±505.7/mm2 in the survivor and 624.0±287.6/mm2 in the nonsurvivor group). 2) The T-lymphocyte count of the nonsurvivor group(295.9±203.0/mm2) was lower than the survivor group(723.6±406.5/mm2) (p<0.05). 3) The total serum protein(albumin) was 6.0±1.0(2.7±0.7) g/dl in the survivor and 5.2±1.5(2.3±0.8)g/dl in the nonsurvivor group. The BUN of the noncurvivor group(41.7±30.0mg/dl) was higher than that of the survivor group(18.9±9.8mg/dl)(p<0.05). The creatinine concentration was higher in the nonsurvivor group(1.8±1.0mg/dl) than that in the survivor group(1.0±0.3mg/dl)(p<0.05). 4) The immunoglobulin G level was higher in the survivor group (1433.0±729.5mg/dl) than in the nonsurvivor group(849.1±373.1mg/dl)(p<0.05). 5) The complement C3 level was 108.0±37.9mg/dl in the survivor group and 88.0±32.1mg/dl in the nonsurvivor group. 6) A cytokine study showed an insignificant differenne in both groups. 7) Chronic liver disease, DM, and COPD were major underlying diseases in both groups. CONCLUSION: These results suggest that decreased a T-lymphocyte count and immunoglobulin G level, and an increased BUN and creatinine level may be associated with the poor prognosis of severe community-acquired pneumonia.

A Case of Nonspecific Interstitial Pneumonia Associated with Systemic Lupus Erythematosus / 결핵

Systemic lupus erythematosus frequently has thoracic involvement among connective tissue diseases. One of the pleuropulmonary manifestations is diffuse interstitial lung disease including nonspecific interstitial pneumonia(NSIP). NSIP if a newly classified disease among interstitial lung diseases. Systemic lupus erythematosus has a better prognosis than usual interstitial peumonia(UIP) and responds well to steroids. In this report, a 34 year-old woman who complained of a dry cough, and exertional dyspnea for 2 months is described. The chest X-ray showed fine reticular opacities and a mild honeycomb appearance in both basal lungs. High resolution computed tomography(HRCT) showed bilateral patchy areas of ground-glass attenuation and a mild honeycomb appearance in the subpleural of both the lower and the middle portion of the lung fields. An open lung biopsy showed prominent lymphocytic interstitial inflammation and fibrosis with small are as with a honeycomb appearance. This case was diagnosed as NSIP associated with systemic lupus erythematosus and was managed with oral steroids. Here we report a case of nonspecific interstitial pneumonia associated with systemic lupus erythematosus confirmed by HRCT and an open lung biopsy with a review of the relevant literature.

Effect of Inhaled Fluticasone Propionate on Hypothalamic-Pituitary-Adrenal Axis in Bronchial Asthma Patient / 결핵

BACKGROUND: Inhaled glucocorticoids are the medical treatment of choice in asthma patients. Fluticasone propionate is one of the most effective inhaled corticosteroids and has been reported to have minimal effect on the hypothalamic-pituitary-adrenal axis at the recommended dose. However, reports of long-term trials characterizing their systemic safety with chronic use are rare. This study was designed to evaluate the long-term safety of inhaled fluticasone propionate to the hypothalamic-pituitary-adrenal axis. METHOD: This study was conducted on 21 patients to evaluate the adrenal response to rapid ACTH stimulation test after 6 months of treatment with fluticasone propionate from 200 µg to 750 µg daily. The serum cortisol levels was measured to assess its effect on the hypothalamic-pituitary-adrenal axis just prior to the injection, at 30 minutes and 60 minutes after an intramuscular injection of synthetic ACTH. RESULT: The mean dose of inhaled fluticasone propionate was 355 µg per day(SD=174 µg, range=200 µg to 750 µg). The mean serum cortisol levels of the patients was 11.0 µg/dl(SD=6.4 µg/dl) prior to the injection, 20.0 µg/dl(SD=7.7 µg/dl) after 30 minutes, and 23.0 µg/dl(SD=6.3 µg/dl) after 60 minutes. Sixteen patients of the 21 patients had a normal response(>18 µg/dl), and 5 out of the 21 patients had serum cortisol levels below the normal range after the rapid ACTH stimulation test. CONCLUSION: Adrenal suppression occurred in 5 out of 21 patients with 6 months treatment with inhaled fluticasone propionate.

Expression of p53, bcl-2 Protein in Small Cell Lung Cancer (SCLC) Cell Lines in Relation to Sensitivity to Chemotherapy / 대한암학회지

PURPOSE: Sensitivity of tumor cells to chemotherapeutic regimen may be accentuated by their abnormal expression of oncogene. p53 is required for the efficient activation of apoptosis following irradiation or treatment with chemotherapeutic agents. The aim of this study was to evaluate the relationship between chemosensitivity and apoptosis related proteins such as p53, bcl-2 in small cell lung cancer cell lines. MATERIAL AND METHODS: Six human small cell lung cancer cell lines, NCI-H69, NCI-H128, NCI-H1436, NCI-H1092, derived from untreated and treated patients were tested for chemo sensitivity and the expression of the p53, bcl-2 genes were examined in each cell lines with western blot analysis. We used 4 drugs including adriamycin, cisplatin, vincristine and VP-16. RESULTS: NCI-H128 was the most sensitive cell line to four drugs. NCI-H82 and NCI-H1092 were highly resistant to VP-16, adriamycin and vincristine and determination of an IC50 was not possible. In western blot analysis, NCI-H128 alone was strong positive to p53 monoclonal antibody and the rest of cell lines were negative. All but NCI-H128 were positive to bcl-2 monoclonal antibody. NCI-H128 which was strong positive to p53 and negative to bcl-2. NCI-H1092 was strong positive to bcl-2 and negative to p53 monoclonal antibody. CONCLUSION: We were not able to explain the expression of p53 in small cell lung cancer cell lines in relation to senitivity to anti-cancer chemotherapeutic agents. But the expression of bcl-2 in small cell lung cancer cell lines was correlated with the chemosensitivity well.

Multi-center study for the utilization of quality of life questionnaire for adult Korean asthmatics (QLQAKA) / 천식및알레르기

BACKGROUND AND OBJECTIVE: Assessment of quality of life (QOL) of patients with chronic illness requires reasonable tools which reflect the patients' cultural and behavioral properties. We developed the quality of life questionnaire for adult Korean asthmatics (QLQAKA) on the basis of the Korean life style and evaluated its reliability and validity. METHODS: The QLQAKA consisted of four domains; symptoms (six items), daily activity (five items), emotion (three items) and reaction to environmental stimuli (three items). Patients answered each item according to a five-response scale. The reproducibility and validity of the questionnaire was estimated from the responses of 244 patients who visited the clinics in 15 institutes within a 2-week interval. RESULTS: Items with the most frequent complaints were dyspnea (87%), difficulty in sputum discharge or throat clearing (87%), limitation in strenuous activity (84%) and coughing (82.4%). The QLQAKA reflected the changes of patients' status very well. The value of minimal important differences, such as the clinically significant minimal change in the QOL score, was 0.5. The questionnaire was also highly reproducible with the value of intraclass correlation coefficiency and intraclass standard deviation as 0.940 (p<0.001) and 0.180, respectively. The changes of mean total QLQAKA score correlated weakly with the changes of FEV1 and PEFR values. CONCLUSION: The adult version of QLQAKA was valid and may be a reproducible tool for evaluating and monitoring Korean adult asthma patients.

A Case of benign metastasizing leiomyoma in the lung / 결핵

Benign metastasizing leiomyoma usually occurs in women and is associated with a past hysterectomy in 80% of the cases, which is a rare entity. The patient was a 39-year-old woman who complained of cough and sputum. She underwent hysterectomy beacuse of benign leiomyoma ten years age. Chest X-ray showed nodular lesion in the left lung field. Chest CT showed a 3cm sized round well defined mass at left hilum with mild indentation of segmental bronchi of left upper lobe and a small tiny nodule in right lower lung field. Nodular lesion of left upper lobe was resected by thoracotomy.Pathological evaluation showed benign spindle-like cells having nuclei without cytotic atypia similar to those of benign leiomyoma. Immunohistochemical stainings for desmin and smooth muscle actin were positive. Therefore these nodules are considered as benign metastasizing leiomyoma from a uterine leiomyoma. We report this case with the review of literature.

Morphological Study of Effects of Oxidized Low Density Lipoprotein on Three Dimensionally Constructed Vascular Wall

PURPOSE: The purpose of this experiment was to study the effects of Ox-LDL (oxidized low density lipoprotein) and Ox-VLDL (oxidized very low density lipoprotein) with or without probucol treatment on the proliferation of human vascular endothelial cells (EC) which were three dimensionally constructed vascular wall model. METHOD: The thiobarbituric acid reactive substance content of LDL and VLDL oxidized by incubation with copper irons was consistently greater than 10 nM malondialdehyde (MDA)/mg protein compared with less than 3 nM MDA/mg for unmodified lipoprotein immediately after isolation. On agarose gel electrophoresis, Ox-LDL and Ox-VLDL were shown to have greater cationic charge than unmodified lipoprotein. RESULT: In Ox-LDL stimulated ECs, the cellular enzymatic activity was markedly decreased in 50 mug/ml concentration of Ox-LDL and was protected by 10 nM probucol. And in Ox-VLDL stimulated ECs, the cellular enzymatic activity was markedly decreased in 25 and 50 mug/ml concentration of ox-VLDL and was not protected by 10 nM probucol. On scanning electron microscopy (SEM) and transmission electron microscopy (TEM), endothelial layers of control, unmodified LDL and unmodified VLDL groups showed similar appearance. But in Ox-LDL and Ox-VLDL groups, cellular edema, loosened cell-to-cell contact and loss of microvilli were shown on SEM, and marked cellular edema, distortion of cell membrane, loss of intracellular organelles and destruction of nulcleus were shown on TEM. And the protective effect of probucol was definite in Ox-LDL group but in 25 and 50 mug/ml concentration of Ox-VLDL group, there were no protective effects of probucol. CONCLLUSION: As a conclusion, three dimensionally constructed vascular wall model is to be a good experimental model for vascular research. And Ox-LDL and Ox-VLDL have toxic effects on vascular endothelial cell layer and its toxic effects are partially prevented by probucol.

A case of primary diffuse nodular pulmonary amyloidosis localized in the lung / 결핵

Nodular pulmonary amyloidosis is one of the rare manifestation of amyloid disease. It is known to be caused by anyloid L fibrils in the majority of case. We experienced an unusual case of a forty-one year-old woman who was presented with multiple nodular lesion on the chest X-ray. CT-guided core needle bilpsy, performed on the lesion, showed apple green birefringes, when stained Congo red and examined under polarized light. Ultrastructurally, there are randomly oriented, forming densed networks, and consists of fine, 7.5 to 10nm diameter, rigid, non-branching filaments of various lengths in electron-microscopic finding. We report a case of primary diffuse nodular pulmonary amyloidosis only localized in the lung, which was confirmed by CT guided core needle biopsy.

Are Churg-Strauss syndrome and idiopathic hypereosinophilic syndrome in the same spectrum?: A case with overlapping features / 천식및알레르기

Sometimes, it is difficult to distinguish Churg-Strauss syndrome from idiopathic hypereosinophilic syndrome and there may be overlap syndrome in the differential diagnosis of systemic vasculitis with hypereosinophilia. Recently, we experienced a 42-year-old female patient who presented signs and symptoms of cardiac failure and neuropathy with peripheral hypereosinophilia. She had no history of asthma. She had erythematous skin lesions and distal digit necrosis. The cause of hypereosinophilia could not be identified. Skin and nerve biopsy revealed vasculitis with eosinophilic infiltration. Cardiac failure improved dramatically with steroid, inotropics and diuretics. Other symptoms including digital necrosis also improved. During steroid, tapering peripheral eosinophilia recurred. For maintenance therapy, we added daily cyclophosphamide to every-other-day prednisolone therapy. We report the case with a review of the literature.

In Vitro Tissue Engineering of Cartilage using Autologous Fibrin Glue and Chondrocytes

Neomorphogenesis of cartilage using chondrocyte-polymer constructs is a potential source for development of cartilage reconstruction. Current tissue engineering techniques of neocartilage rely on in vivo implantation of polymer-chondrocyte constructs. The purpose of this study was to find a way to bioengineer cartilage in vitro by entrapping chondrocytes in a molded autologous fibrin glue. Chondrocytes isolated from the cartilage of rabbit joints were combined with fibrinogen extracted by a single cryoprecipitation of autologous plasma, and they were then polymerized with thrombin to create a fibrin glue with a final cell density of 2.5x10(6) cells/ml. The collagen for a control study was used as a polymer. The polymer-chondrocyte constructs were cultured for 4 weeks and the fibrin-chondrocyte constructs molded in the shape of a human ear were cultured for 6 weeks in vitro. Morphometric, histochemical, and histomorphometric analysis including glycosaminoglycan quantitation confirmed the following results: 1) Highly-concentrated autologous fibrinogen was easily extracted by a single cryoprecipition of autologous olasma. 2) The fibrin-chondrocyte constructs demonstrated the presence of actively proliferating chondrocytes with the production of cartilaginous matrix(collagen and glycosaminoglycan) at 1 week after culture, as well as gross and histologic evidence similar to those of normal cartilage at 3-4 weeks after culture. 3) The collagen-chondrocyte constructs demonstrated lower degrees of hardness and transparency, as well as a lower density of cells and glycosaminoglycan during the culture period. 4) Neocartilage generated from fibrin-chondrocyte constructs in the shape of a human ear nearly retained their original configuration and size without degeneration for 6 weeks of culture in vitro. This study demonstrated a novel method for bioengineering the molded cartilage in vitro using autologous fibrin glue as a matrix scaffold. The generated cartilage showed gross and histologic evidence similar to those of normal cartilage, retaining the original gross dimension. With further refinement, this may be a new application of tissue engineering for the reconstruction of cartilage.

Conditional immortalization of human fetal hepatocytes using an amphotropic retrovirus encoding temperature - sensitive SV40 large T antigen / 대한내과학회지

BACKGROUND: Human cells are almost never spontaneously immortalized in vitro. We tried to immortalize human fetal hepatocytes (h-FH) and evaluate the differentiational status and its change. METHODS: Hepatocytes were isolated from a liver fragment of 20 week old fetus and infected with amphotropic recombinant retrovirus containing a temperature- sensitive mutant of SV40 large T antigen and neomycin phosphotransferase gene. G418 resistant colonies were cloned and expanded. The cells which were able to divide more than 30 times were used to analyze various functions. RESULTS: The immortalization rate was 3.3 x 10-8 and two cell lines (C11, D21) were established. C11-60, C11-80, D21-30 and D21-60 (suffix number means the cell division counts) were evaluated. D21-30 was thougt to be imcompletely immortalized because a considerable portion of cells died during culture. The morphology was similar to that of epithelial cells except for D21-30 which looked like fibroblast. The cells grew rapidly at 33oC but stopped growing at 39oC. T antigen and p53 was expressed at 33oC but disappeared at 39oC, which suggest that T antigen binds to p53. Chromosomal changes were so marked that it was impossible to discriminate exact number. Albumin was secreted as about 1/10 as that of h-FH, but alpha-fetoprotein secretion stopped after immortalization. Telomerase was activated in both cell lines except for the incompletely immortalized cells D21-30. Telomere was elongated in competely immortalized cell lines, but it was rather shortened in D21-30 compared to that of h-FH. Macroscopic colonies did not develop in soft agar assay. CONCLUSIONS: We successfully immortalized human fetal hepatocytes. Although the cells are not likely to have oncogenicity, the functions are not so good, possibly due to marked chromosomal changes which are thought to occur before telomerase is activated during immortalization step.

Modulation of Telomerase Activity by p53 Gene in KATO - III Gastric Carcinoma Cell Line / 대한암학회지

PURPOSE: Alteration of p53 and telomerase activity may be responsible for gastric carcino- genesis. In this study, we tried to observe modulation of telomerase activity by wild type p53 in gastric cancer cell lines. MATERIALS AND METHODS: We used five gastric cancer cell lines (KATO-III, AGS, SNU-1, SNU-5, SNU-16). In order to find p53 mutation, we used western blot and PCR-SSCP. The TRAP-eze kit which supplied by Oncor (Gaithersburg, MD) was used to detect telomerase activity of the five gastric carcinoma cell lines. The wild type p53 gene was transfected by electroporation method. RESULTS: The expression of p53 protein was increased in four gastric carcinoma cell lines and one cell line (KATO-III) did not express. We found p53 point mutation in exon 5 and 8, and the p53 gene was deleted in KATO-III. The telomerase activity were observed in all five gastric carcinoma cell lines and there were no difference in telomere repeat length among five cell lines. After transfection with wild type p53, we could not find the change of telomerase activity in KATO-III. CONCLUSION: Although activation of telomerase activity and mutation of p53 gene may be needed in gastric carcinogenesis, the telomerase activity was not affected by restoration of p53 function in gastric carcinoma cell lines.

Transplantation of Cultured Keratinocytes in Autologous Fibrin Glue Suspension

The use of a cultured autologous keratinocyte sheet has become a recognized method for the coverage of extensive bums during recent years. The disadvantages of these sheet grafts are a long time-lag until keratinocyte sheets are available, the fragility and difficulty in handling of grafts, an unpredictable take rate and extremely high costs. In this study we investigated the transplantation of cultured keratinocytes as single cells suspended in autologous fibrin glue. In a rat model with standardized full thickness wounds, this new transplantation technique was evaluated and compared directly to the conventional keratinocyte sheet grafting technique. After transplantation, wounds were evaluated for the degree of epithelial coverage, and then microscopic structures were evaluated under light and electron microscopy. The results were as follows: 1) The fibrinogen solution prepared from autologous blood had 12 times more fibrinogen compared to the original blood. 2) After transplantation of cultured keratinocyt-es in fibrin glue, the degree of epithelial coverage was 79% at 2 weeks, which was comparable to 17% for cultured keratinocyte sheet graft 3) Typical basement membrane structures were consistently found at 2 weeks after transplantation of keratinocytes in fibrin glue. 4) Rete ridges were found at 4 weeks after transplantation of keratinocytes in fibrin glue. In conclusion, the transplantation technique of keratinocytes in fibrin glue is available earlier than sheet grafts, it transfers actively proliferating cells and it simplifies the grafting procedure. As well, this technique leads to an earlier epithelial covering and an earlier restoration of the dermo-epidermal junction than sheet grafting.