OBJECTIVE: To observe the effects of silks on attachment, shape and function of chondrocytes cultured in vitro. METHODS: The silks from silk worm cocoons were digested by trypsin and coated with polylactic acid to from three dimensional scaffolds for rabbit rib chondrocyte culture. The growth and shape of chondrocytes were observed with phase contrast microscopy, scanning electron microscopy. RESULTS: The chondrocytes were adhered to silks slowly after chondrocytes were seeded into silk scaffolds and cells fixed on silks well 1 or 2 days later. Cells began to proliferate after 3 days and multiplicative growth was observed on the 6th day. Microholes of silk scaffolds were filled with chondrocytes 2 weeks later. Scanning electron microscopy showed that there was a lot of extracellular matrix surrounding cells. CONCLUSION: Silks are ideal for attachment, growth and function maintenance of chondrocytes, and silks can be used as scaffolds for chondrocytes in three dimensional culture.
Osteoblasts were cultured and isolated from a piece of tibial pettiosteum of four New-Zealandrabbits. After subeultured,these cells Were incubatd in vitro with tritiated thvmidine for 36 hoursand then these labeled cells were implanted in the subeutaneous layer of the defects of the auriclarcartilage and the radial bone, After 2 weeks and 4 weeks respectively, these rabbits were killed andthe spoimens were obtained from the site where the cells had been transplanted. The transformation of these cells was observed by autoradiographic method. The results indicated that nearly all of the cultured cells were labeled. After 2 weeks, it was observed that many labeled osteoblasts were in different stages of differentiation, some were beried by extracellular matrix and resembled osteocyte, thers were differentiated into chondrocyte-like cell. In addition, some labeled osteoblasts were congregated in the form of multinucleated osteoclast. After 4 weeks , in the subcutaneous layer the labeled osteoblasts were changed to osteoid tissue and in the defect of the auricular crtilage these cells transformed into chondritic tissue; moreover, those labeled osteoblsts which had been implanted into the radial defect had differentiated into typical bone tissue. The results of this research indicated that the osteoblasts isolated from the periosteum if reimplanted to the same donor might be possible to repair the bone and cartilage defects.
The osteogenc potential of bone marrow has been proved by experiment. To investigate more in details, bone marrow was obtained from the trochanteric region of femur of NewZealand rabbit in 4 to 8 weeks old. After being cultured in vitro for one week, the hematopoietic component of the bone marrow had disappeared, thus the stromal cells were obtained. Then the stromal cells were subcultured in cultural fluid containing dexamethasone (10-8 mol/L) and natrium glycerophosphate (10mmol/L). Under the phasecontrast microscope, it was found that being cultured for 15 days. The stromal cells were lined up in one layer and late the secretion activity was increased and gradually transformed into multilayer structure and was congregated into diffused opaque clusters in twenty days. During culture, the cells were examined by tetracycline fluorescence label, histochemistry stains, transmission electron microscopy, scanning electron microscopy and energy dispersive X-ray microanalysis. The results showed that the morphological and biological characteristics of the cultured stromal cells derived from the bone marrow were similiar to those of osteoblasts and could synthesized mineralized new bone tissue in vitro.
ObjectiveTo study the effects of recombinant human growth hormone (rhGH) on proliferation of human rectal cancer cell in vitro. MethodsThe experiment was divided into control group,rhGH group,Oxaliplatin (LOHP) group and rhGH+LOHP group. The double proliferation time of cells,cell inhibition rate,cell cycle, proliferation index (PI) and DNA inhibition rate of human rectal cancer line,HR8348,were studied by cell culture, MTT assay and flow cytometry on different concentration of rhGH. ResultsIn vitro the markedly accelerated effects of rhGH on multiplication of HR8348 cell line were not found: there was no statistical significance as compared rhGH group with control group or compared rhGH+LOHP group and LOHP group （Pgt;0.05）. The double proliferation time of cells was markedly lengthened, cell inhibition rate and the cells arrested in G0-G1 phase were obviously increased, meanwhile, the cells in S phase （P＜0.05） and G2-M phase and PI were markedly decreased and DNA inhibition rate was obviously risen as compared rhGH+LOHP group with control group or rhGH+LOHP group and rhGH group （P＜0.01）.ConclusionIn vitro rhGH does not accelerate the multiplication of human rectal cancer cells.
Objective To investigate the role of transforming growth factorβ3 (TGF-β3) on the amylase secretion of rat submandibular gland cells(RSGCs).Methods The RSGCs were cultured and identified. The expressions of CK 8.13, S100 and Vimentin in the RSGCs were examined by immunohistochemical staining. The experimental group was divided into 5 groups according to differentconcentrations of TGF-β3 (0.5, 1.0, 5.0, 10.0 and 25.0 ng/ml) and no TGF-β3 culture was used as control group. The effects ofTGF-β3 on the cell proliferation and amylase secretion were examined at the24th, the 48th, the 72nd and the 96th hour. MTT colorimetric method was used to estimate vital force of culture cells. Amylase protein was assayed by autobiochemistry equipment and Western blotting.Results The RSGCs were stained positively for CK 8.13 and S-100, but negatively for Vimentin. There were no significant differences in absorbency between the experimental groups and the control group(Pgt;0.05). Compared with the control group,TGF-β3 at concentrations of 0.5-10.0 ng/ml significantly stimulated the amylase secretion of RSGCs after 72 and 96 hours(Plt;0.01). But high concentration of TGF-β3 (25.0ng/ml) showed no stimulation. Western blotting demonstrated that the cultured RSGCs and submandibular gland had the same band of amylase electrophoresis.Conclusion TGF-β3 can stimulate RSGCs to differentiate and to secrete amylase, but TGF-β3 has no effect on proliferation ofRSGCs.
Objective To establish a culture system in vitro of fetal and adult human retinal neural cells provide a model for the basic research of retinal neural cells and the medicinal exploitation. Methods Fetal human retinas(10~13 weeks after conception) and adult human retinas(20~40 years old) were dissected, dissociated, and put into culture plate which was coated with polylysine or rat tail gel. Specific growth factor EGF、FGF、BDNF or NT-4 were added to the culture medium. BrdU incorporation, Tunnel assessment and immuno-histochemistry and immuno-fluorescent staining were applied to determine cells proliferation, apoptosis and identify the component of cultured cells. Results Fetal human retinal cells and adult human retinal cells survived for up to 100 and 180 days in vitro. The addition of EGF、FGF、BDNF or NT-4 promoted the survival of both fetal and adult retinal neurons and stimultated proliferation of fetal retinal cells. The neurons or the rate of ganglion cells was observed with higher percentage in the group with growth factor adding than the group without. Conclusion Fetal and adult human retinal cells can be maintained in vitro and the fetal cells also can be expanded, which are helpful to generate retinal neurons for basic research and drug exploitation. The exogenous growth factors added to the culture medium can promote survival, proliferation and differentiation of retinal cells in culture. (Chin J Ocul Fundus Dis, 2002, 18: 279-282)
OBJECTIVE: To investigate the biological characteristics of human muscle satellite cell cultured in vitro. METHODS: Human muscle satellite cells were obtained from skeletal muscle biopsies of six patients during corrective orthopedic surgery, cultivated in growth medium for ten days, then in differentiation medium for additional five days. Human satellite cells were identified with monoclonal antibody against desmin. Cells were observed under phase contrast microscopy. RESULTS: Human muscle satellite cells proliferated in growth medium, and fused to form myotubes in differentiation medium. After 24 hours in differentiation medium, the confluent satellite cells began to fuse actively and achieved the top level at 72 hours. CONCLUSION: Human muscle satellite cell can proliferate and differentiate in appropriate culture condition. Immunocytochemical detection of desmin is the effective early method to determine satellite cell.
The effects of pentagastrin (PG) on the viable cell count (Α value) and the synthesis of DNA (CPM value) of primary cultured large bowel carcinoma cells in 25 patients were evaluated in vitro by MTT assay,3H-TdR incorporation. The results showed that Α value and CPM value in well， moderately and poorly-differentiated carcinoma cells were higher than normal control (Ｐlt;0.01，Ｐ＜0.05). The proliferative effect was significant at a dose of 0.3907 μg/ml in well-differentiated carcinoma cells, and at a dose of 6.2500μg/ml in moderately and poorly-differentiated carcinoma cells. These indicat that PG has the proliferative effect on large bowel carcinoma cells. These results provide an experimental foundation for the endocrine therapy for patients with large intestine carcinoma, especially by using gastrin receptor antagonists for well-differentiated carcinoma.
OBJECTIVE To search an optimal method for improving viability of cryopreserved articular cartilage. METHODS Articular cartilage which was sampled from the rabbits were randomly divided into 5 groups. Fresh cartilage was group I, other groups were frozen. Before frozen, other cartilage was exposured in 10% DMSO at 4 degrees C for 30 minutes(group II), 1 hour(group III), 2 hours (group IV), 4 hours(group V), then were stored in liquid nitrogen for 1 week. Viabilities of the chondrocytes were detected by Typan-blue staining, electron transmission microscope, and determination of incorporation 3H-TdR after the temperature returned to normal. RESULTS 1. The cells were injuried at different extent after the cartilage was frozen. In group I, survival rate of cells was 96% and incorporation of 3H-TdR was (4,953.13 +/- 583.27)%, statistic difference was significant between group I and other groups(P lt; 0.01). The microstructure of group I was normal while other groups all had damage of the organella, 2. Structures and functions of cells in group IV were best among frozen groups. Organella were less damaged than group II, III, V, survival rate of cells was 56% and incorporation of 3H-TdR was (1,139.88 +/- 146.39)%, statistic difference was significant between group IV and group II, III, V(P lt; 0.01). CONCLUSION If cartilage are exposured in 10% DMSO at 4 degrees C for 2 hours before frozen, optimal cryopreservation can be achieved.
【Abstract】ObjectiveTo establish an efficient, effective hepatocyte isolation technique in order to increase cell production and decrease the prime cost. Methods The inferior vena cava below diaphragm was dissected and ligatured, and the inferior vena cava below liver was separated. Subsequently, the liver was perfused with EGTA through the portal vein while the inferior vena cava below liver was opened, and then the liver was harvested. The liver tissue was cut into 1 mm×1 mm×1 mm and digested at 37 ℃ water bath with Ⅳ collagenase for 30-40 minutes, then the hepatocytes were purified and cultured in CO2 incubator. The production and function of hepatocytes were assessed. ResultsThe isolated hepatocytes using this technique were more than 95% among the all isolated cells. No statistic difference was found in cell production and cell function comparing with traditional technique. But this technique was simplified and more economically. ConclusionThis modified hepatocyte isolation technique is efficient and effective. It can ensure the amount of production and purity of hepatocytes.