Biomedical subjects

Lei Cui

Publications and source records attributed to Lei Cui.

At least 55 records · Page 3Linked to original sources

PubMed2004

Absolute configuration determination of angular dihydrocoumarins from Peucedanum praeruptorum.

From Peucedanum praeruptorum, one new khellactone ester (3'R)-O-acetyl-(4'S)-O-angeloylkhellactone (3), as well as four known angular dihydropyranocoumarins (1, 2, 4, 5) have been isolated. On the basis of NMR spectra and X-ray crystallography, their structures were determined. We have elucidated their absolute configuration by either chiral separation of their alkaline hydrolysis products with Rp-18 HPLC eluted with 5% hydroxypropyl-beta-cyclodextrin (beta-HCD) or by measurement of their CD spectra. A general rule relating the position and absolute streochemistry of the khellactone esters to the sign of their Cotton effects in CD curves is proposed.

Apiaceae↗

PubMed2004

A study on a chitosan-gelatin-hyaluronic acid scaffold as artificial skin in vitro and its tissue engineering applications.

Chitosan-gelatin-hyaluronic acid scaffolds for tissue regeneration were fabricated by freezing and lyophilizing methods. The scaffolds showed a higher water uptake and retention abilities than chitosan-gelatin scaffolds did. Fibroblasts cultured in chitosan-gelatin-hyaluronic acid scaffolds grew and proliferated well, and they exhibited a strong viability. Keratinocytes were co-cultured with fibroblasts in chitosan-gelatin-hyaluronic acid scaffolds to construct an artificial bilayer skin in vitro. The artificial skin obtained was flexible and had good mechanical properties. The data from this study suggested that chitosan-gelatin-hyaluronic acid scaffolds are suitable for preparing a bilayer skin substitute.

Biocompatible Materials↗

PubMed2004

[In-vivo tracing of bone marrow stromal cell differentiating into chondrocytes by green fluorescent protein gene transfection].

AIM: To achieve highly efficient, stable and long-term expression of green fluorescent protein(GFP) reporter gene in bone marrow stromal cells(BMSCs) and to trace directly the distribution and differentiation of BMSCs in articular cartilage defects. METHODS: Recombinant RV-GFP expression vector was constructed and transfected into packaging cell PT67. After G418 screening and amplification, cell clones producing high level recombinant viruses were obtained and in-vitro expanded. The virus supernatant from infected PT67 cell culture was used to infect BMSCs directly. Autologous GFP-labeled BMSCs were seeded onto biodegradable polymer and implanted into porcine articular cartilage defects. 7 months later, the repaired tissue was evaluated by confocal microscope. RESULTS: The constructed recombinant expression vector RV-GFP was identified by restriction digestion. The transfection rates of PT67 cells reached 20%-50%, which reached 100% after G418 screening, bright green fluorescence could be seen under fluorescence microscope. BMSCs could be transfected successfully by the culture supernatant from infected PT67 cells and GFP was expressed efficiently in a long-term period. Confocal microscope revealed that GFP-labeled cells existed in many neocartilage lacunae after 7 months. CONCLUSIONS: The recombinant vector RV-GFP can provide a simple, sensitive and reliable tool to label BMSCs which can be used to study cytologic dynamic follow-up in-vivo. BMSCs can differentiate into chondrocytes and play an important role in repairing articular cartilage defects.

Animals↗

PubMed2004

[Regeneration of autologous tissue-engineered cartilage by using basic-fibroblast growth factor in vitro culture].

OBJECTIVE: To investigate the effect of the basic fibroblast growth factor (b-FGF) to regenerate an autologous tissue-engineered cartilage in vitro. METHODS: The Cells were harvested from the elastic auricular cartilage of swine,and were plated at the concentration of 1 x 10(4) cells/cm2 , studied in vitro at two different media enviroments: Group I contained Ham's F-12 with supplements and b-FGF, Group II contained Ham's F-12 only with supplements. The passage 2 cells (after 12.75 +/- 1.26 days) were harvested and mixed with 30% pluronic F-127/Ham's F-12 at the concentration of 50 x 10(6) cells/ml. It was injected subcutaneously at 0.5 ml per implant. The implants were harvested 8 weeks after the vivo culture and examined with the histological stains. RESULTS: The chondrocytes displayed morphologically similar to the fibroblasts in the media containing basic-FGF. The number of cell doublings (after 12.75 +/- 1.26 days) in vitro culture was as the following: Group I, 70; Group II, 5.4. Eight 8 weeks after the vivo autologous implantation, the average weight (g) and volume (cm3) in each group was as the following: Group I, 0.371 g/0.370 cm3 Group II, 0.179 g/0.173 cm3 (P < 0.01). With the b-FGF in vitro culture, the cells were expanded by 70 times after 2 weeks. Histologically, all of the engineered cartilage in the two groups were similar to the native elastic cartilage. CONCLUSION: These results indicate that the basic-FGF could be used positively to enhance the quality and quantity of the seeding cells for the generation of the well-engineered cartilage.

Animals↗

PubMed2004

[Age-related changes in growth and metabolism function of human costal chondrocytes cultured in vitro].

OBJECTIVE: To investigate the expressive changes of collagen I, II and aggrecan during the aging of the human costal chondrocytes cultured in vitro, in order to select the best chondrocytes for cartilage engineering. METHODS: The human costal chondrocytes from the different passages (P1-P5) were harvested. The morphological changes and cell proliferation rate were observed, and the quantity of glycosaminoglycans (GAGs) was examined in each passage with alcian blue precipitation. The expression of collagen I, II and aggrecan was measured with immunohistochemistry and RT-PCR method. RESULTS: From the third passage, the human costal chondrocytes were transformed into fibroblast-like cell morphology; and the GAGs content in each passage was decreased and became significantly low in the third passage. The expression of the collagen I, II was consistent in the protein level with that in the mRNA level. Before the second passage, the expression of collagen II was high while the collagen I was low. After the second passage, the expression of collagen II decreased while the collagen I increased. The expression of aggrecan was high before the third passage, and then became low in the fourth passage. CONCLUSION: With the examinations of the cell proliferating rate and cell functions in human chondrocytes cultured in vitro, the chondrocytes of the second passage seem suitable for human cartilage engineering.

Aggrecans↗

PubMed2004

[Effects of hVEGF cDNA on random skin flap via a replication-deficient adenovirus vector].

OBJECTIVE: The purpose of this study was to determine the effects of local delivery of vascular endothelial growth factor( VEGF) transferred with adenovirus-mediated gene on the survival of ischemic random skin flap in rats. METHODS: The animals were divided into three groups randomly (n = 10) . A 2 cm x 8 cm dorsal skin flap was designed with the pedicle at the level of the iliac crest. In group A (AdCMV-VEGF), each animal received 10(12) PR replication-deficient recombinant adenovirus (AdCMV-VEGF) in the distal two-thirds of the proposed flap by means of the subdermal injection at ten different locations. In group B (AdCMV-GaI), each received 1012 PR AdCMV-Gal. In Group C (Saline), each received 1 ml saline. Three days after the treatment, the flap was elevated as planed way and re-sutured back to its donor site. All the animals were evaluated 7 days after the operation. RESULTS: The mean percentage of surviving flap area was (85.91 +/- 2.54)% in group A, (59.56 +/- l.18)% in group B, and (61.48 +/- l.09)% in group C. There was a significant increase in the percentage of the survival area in the flaps of the group A, compared with the group B and group C (Group B vs. Group A, P < 0.01; Group C vs.Group A, P < 0.01, Group B vs. Group C, P >0.05). Hybridization in the situ, the immunohistochemical stain showed that the VEGF was expressed in the survival tissue of the flap treated with the AdCMV-VEGF, but it was not found in the control groups. Histological analysis demonstrated qualitatively greater amount of granulation tissue and angiogenesis was found in the group treated with the AdCMV-VEGF than the controls. CONCLUSIONS: The results may indicate that Ad vector carrying VEGF cDNA could be useful in enhancing the survival of the skin flap due to the effect of the local delivery of the VEGF.

Adenoviridae↗

PubMed2004

[Experimental study on biological character changes of human epidermal cells during proliferation culture in vitro].

UNLABELLED: [Abstract] OBJECTIVE: The study was (1) to investigate the biological character changes of human epidermal cells during proliferation culture in vitro and (2) to provide data for construction of engineered skin. METHODS: The foreskin was collected from 20 healthy children. The epidermal cells were isolated with digestion of the foreskin and cultured in vitro. Growth curve was obtained from the data of cell counting. Cell growth kinetics was observed. Meanwhile, clonal analysis and cell size measurement was performed. The rate of keratin 19 (K19) and involucrin expression-positive cells was counted by flow cytometer. Expression of K19 and involucrin mRNA was detected by RT-PCR. RESULTS: When passaged to P6, the keratinocytes from child foreskin could be expanded by (700 +/- 37) times. Flow cytometer results showed that the percentage of K19 expression-positive cells decreased from (66.97 +/- 3.14)% to (4.65 +/- 1.38)% while the percentage of involucrin expression-positive cells increased from (11.65 +/- 1.62)% to (97.03 +/- 2.66)% at P0 and P6 respectively. RT-PCR results showed that expression of K19 mRNA decreased from P0 to P6 while involucrin mRNA kept stable with passage in vitro. CONCLUSIONS: Human epidermal cells of passage 5 maintain proliferation phenotype, which are suitable for skin tissue engineering. Decrease of proliferation phenotype content is partially responsible for the proliferation capacity loss of in vitro cultured epidermal cells.

Cell Proliferation↗

PubMed2003

[Clinical application of tissue engineered bone repair of human craniomaxillofacial bone defects].

OBJECTIVE: To explore the feasibility of tissue engineered bone formation in human being using human bone marrow stromal cells (hBMSCs) and the possibility of clinical repair of craniomaxillofacial bone defects with tissue engineered bone. METHODS: Total 11 patients of cranial defects and aperture piriformis bone depression were included in this study. The hBMSCs were isolated by Percoll gradient centrifugation from patient's bone marrow aspirated from iliac crest. The hBMSCs were cultured in vitro and induced to become osteogenic cells in the DMEM medium containing 10% self-serum, beta-glycerophosphate (10 nmol/L) dexamethasone (10(-8) mol/L), L-2-ascorbic acid (50 micro mol/L), and 1, 25 (OH)(2)VD(3)(10 nmol/L). Induced hBMSCs of passage 3 were harvested and seeded onto partly demineralized allogenic bone matrix (pDBM) to form a cell-scaffold construct and in vitro co-culture for 1 week. The defects were repaired with the cell-scaffold construct. In 3 cases of aperture piriformis bone depression, one side was repaired with hBMSC/pDBM, while the other side was repaired by pDBM alone. All cases were followed up for 1, 3, 6 months post-operation as short-term evaluation and 1 to 2.5 years post-operation as long-term evaluation by three-dimensional computerized tomography (3D-CT) and clinical examination. In 2 cases who received secondary surgery, extra engineered bone tissue and control pDBM were harvested at the implantation sites for histological examination and immunohistochemistry. RESULTS: 3D-CT demonstrated that engineered bone was formed in 3 to 6 months post-operation. Additionally, formed bone maintained stable up to 1 - 2 years without absorption. Histologically, engineered bones revealed their structures similar to that of normal bone in HE staining. Interestingly, endochondral ossification was also observed in engineered bone. Immunohistochemistry shows positive staining of osteonectin and osteocalcin in engineered and normal bones. In contrast, implanted pDBM was completely degraded in 3 - 6 months as revealed by 3D-CT. Histologically, degraded pDBM and fibrous tissue were observed in the sites where pDBM alone was implanted. CONCLUSIONS: Tissue engineered bone can be formed in human being. Engineered bone can be used to repair clinical bone defect with satisfactory result. Furthermore, the result of this study proves that tissue engineered bone is possible for clinical application.

Adolescent↗

PubMed2003

[Repair of alveolar bone defect with tissue engineered bone: an experimental study of dogs].

OBJECTIVE: To study the feasibility of repairing experimental horizontal alveolar bone defects by tissue engineering based on bone marrow stromal cells (BMSC). METHODS: Dog bone marrow mononuclear cells were isolated from the bone marrow by gradient centrifugation and then cultured in conditional medium to be induced to become osteogenic. Immunohistochemistry was used to examine the expression of core-binding factor alpha subunit 1 (Cbfa1), osteocalcin (OCN), and type I collagen in the cultured BMSCs. Histochemical technique was used to examine the expression of alkaline phosphatase (AKP) in the BMSCs. Inversed phase-contrast microscopy and electron microscopy were used to observe the morphology and proliferation of the BMSCs. Induced BMSCs at passage 3 were harvested and mixed with calcium alginate to form a gelatin form cell-scaffold construct. A horizontal alveolar bone defect (5 mm high) was created surgically in each buccal side of the mandibular premolars 3 and 4 and molar 1 of 11 dogs. The defects was randomly repaired with a cell-scaffold construct (experimental group, 20 teeth), calcium alginate alone (control group A, 15 teeth), or left untreated (control group B, 12 teeth). At four, twelve, and twenty-four weeks after operation, 2, 7, 2 dogs were killed respectively and block sections of mandibular bones at the defects were collected and processed for gross and histological observation as well as X-ray examination. The status of bone repair 12 weeks after operation in the 3 groups was compared. RESULT: In vitro induced BMSCs exhibited an osteogenic phenotype. Since the passage 3 calcium salt sedimentation could be seen in the extracellular stroma of BMSCs. Cbfa1, type I collagen, and AKP were expressed in the BMSCs in every passage. OCN was expressed since the second passage. Histologically, bone nodule structure was observed in the experimental group 4 weeks after operation. The engineered bone became more mature, similar to the normal bone, 12 weeks after operation. Twelve weeks after operation, the alveolar ridge regeneration amounted to a repair height of 2.43 +/- 0.93 mm, 0.98 +/- 0.87 mm, and 0.78 +/- 0.75 mm and reached 48.59%, 19.74%, and 15.76% of the original height in the experimental group, control group A, and control group B respectively, with a significant difference between the experimental and control groups A and B (all P < 0.01). CONCLUSION: BMSCs can be induced to become osteogenic and be used as seed cells to engineer bone tissue and repair experimental alveolar bone defect.

Alkaline Phosphatase↗

PubMed2003

Glucose-6-phosphate dehydrogenase modulates cytosolic redox status and contractile phenotype in adult cardiomyocytes.

Reactive oxygen species (ROS)-mediated cell injury contributes to the pathophysiology of cardiovascular disease and myocardial dysfunction. Protection against ROS requires maintenance of endogenous thiol pools, most importantly, reduced glutathione (GSH), by NADPH. In cardiomyocytes, GSH resides in two separate cellular compartments: the mitochondria and cytosol. Although mitochondrial GSH is maintained largely by transhydrogenase and isocitrate dehydrogenase, the mechanisms responsible for sustaining cytosolic GSH remain unclear. Glucose-6-phosphate dehydrogenase (G6PD) functions as the first and rate-limiting enzyme in the pentose phosphate pathway, responsible for the generation of NADPH in a reaction coupled to the de novo production of cellular ribose. We hypothesized that G6PD is required to maintain cytosolic GSH levels and protect against ROS injury in cardiomyocytes. We found that in adult cardiomyocytes, G6PD activity is rapidly increased in response to cellular oxidative stress, with translocation of G6PD to the cell membrane. Furthermore, inhibition of G6PD depletes cytosolic GSH levels and subsequently results in cardiomyocyte contractile dysfunction through dysregulation of calcium homeostasis. Cardiomyocyte dysfunction was reversed through treatment with either a thiol-repleting agent (L-2-oxothiazolidine-4-carboxylic acid) or antioxidant treatment (Eukarion-134), but not with exogenous ribose. Finally, in a murine model of G6PD deficiency, we demonstrate the development of in vivo adverse structural remodeling and impaired contractile function over time. We, therefore, conclude that G6PD is a critical cytosolic antioxidant enzyme, essential for maintenance of cytosolic redox status in adult cardiomyocytes. Deficiency of G6PD may contribute to cardiac dysfunction through increased susceptibility to free radical injury and impairment of intracellular calcium transport. The full text of this article is available online at http://www.circresaha.org.

Animals↗

PubMed2003

[The experimental study of tissue engineered autologous cartilage using chitosan-gelatin complex scaffolds].

OBJECTIVE: To investigate whether man-made porous chitosan-gelatin complex scaffold was a appropriate scaffold for tissue engineering cartilage. METHODS: Chondrocytes isolated from Changfeng crossbred swines' auricular cartilage were seeded onto chitosan- gelatin scaffolds to be cultured in a three dimensional environment. The chondrocyte- polymer constructs were implanted into the subcutaneous tissue of the swines' abdomenal wall. Specimens were harvested and analyzed by gross observation, histology, type II collagen immunohistochemistry and biochemistry after 10 and 16 weeks in vivo respectively. RESULTS: H.E staining showed cartilage was formed, and chondrocytes were enclosed in lacuna with histological characteristics similar to natural cartilage. Some clusters of neocartilage surrounded by fibrous tissues were observed. Elastic fibres were observed in the mesenchyma of cartilage 16 weeks after by Vehoeff's staining. Immunohistochemical staining of the neocartilage with anti- type II collagen showed the presence of type II collagen in the ECM of tissue engineered cartilage. The proteoglycans content in tissue engineered cartilage was close to that of natural swine's auricular cartilage. CONCLUSION: The experiments demonstrated that using chitosan-gelatin complex scaffold we can generate autologous cartilage on animals with normal immune system. Porous chitosan- gelatin complex scaffolds may be a suitable scaffolds for tissue engineered cartilage.

Animals↗

PubMed2003

[Inhibiting scar formation in rat cutaneous wounds by blocking TGF-beta signaling].

OBJECTIVE: TGF-beta plays a key role in wound scarring. This study explored the possibility of using gene therapy to inhibit wound scarring by blocking TGF-beta signaling. METHODS: In vitro, human normal dermal fibroblasts were infected with recombinant adenoviruses of truncated TGF-beta receptor II (tTGF-betaRII, 100 pfu/cell) and beta-galactosidase (beta-gal, 100 pfu/cell), and their effects on regulating TGF-beta1 gene expression were analyzed by Northern blot. For gene therapy, beta-gal and tTGF-betaRII viruses (1 x 10(9) pfu)were injected intradermally at left and right side of dorsal skin of newborn Sprague-Dawley rats (n = 15) respectively. A full-thickness incisional wound (0.5 cm long) was created at the injection sites of each rat 2 days post-injection. An incisional wound was similarly created in the middle part of the dorsal skin of tTGF-betaRII transgenic mice (n = 5) and control mice (n = 5). Wound tissues of rats and mice were harvested at various time points post-wounding for histological and immunohistochemical analysis. Scar area in tissue section was measured by Image-Pro Plus software. RESULTS: Over-expression of tTGF-betaRII markedly reduced TGF-beta1 gene expression in dermal fibroblasts. Adenovirus mediated gene expression in skin reached a peak level 2 - 3 days post-injection, and decreased gradually at 5 - 7 days. Two weeks post-wounding, histology and quantitative analysis demonstrated that relative scar area in the wounds of transgenic mice and control mice were 136,969.8 +/- 66,339 and 474,641.6 +/- 227,396 respectively, the scar area of transgenic wounds was 29 percent of control area (P < 0.05). In all rats, wounds transfected with tTGF-betaRII gene healed with much less scarring (relative scar area 128,311.2 +/- 36,764.6) than control wounds (251,189.1 +/- 62,544.7) of the same rat, with a 45% reduction of scar area in average (P < 0.001). In addition, the tTGF-betaRII expression also decreased inflammation and TGF-beta1 production in treated wounds, and promoted the repair of panniculus muscle in treated wounds. CONCLUSIONS: Adenovirus mediated over-expression of tTGF-betaRII can block TGF-beta signaling and inhibit wound scarring, and thus can serve as a gene therapy strategy to control wound scarring.

Adenoviridae↗

PubMed2003

Deletion of cytosolic phospholipase A2 promotes striated muscle growth.

Generation of arachidonic acid by the ubiquitously expressed cytosolic phospholipase A2 (PLA2) has a fundamental role in the regulation of cellular homeostasis, inflammation and tumorigenesis. Here we report that cytosolic PLA2 is a negative regulator of growth, specifically of striated muscle. We find that normal growth of skeletal muscle, as well as normal and pathologic stress-induced hypertrophic growth of the heart, are exaggerated in Pla2g4a-/- mice, which lack the gene encoding cytosolic PLA2. The mechanism underlying this phenotype is that cytosolic PLA2 negatively regulates insulin-like growth factor (IGF)-1 signaling. Absence of cytosolic PLA2 leads to sustained activation of the IGF-1 pathway, which results from the failure of 3-phosphoinositide-dependent protein kinase (PDK)-1 to recruit and phosphorylate protein kinase C (PKC)-zeta, a negative regulator of IGF-1 signaling. Arachidonic acid restores activation of PKC-zeta, correcting the exaggerated IGF-1 signaling. These results indicate that cytosolic PLA2 and arachidonic acid regulate striated muscle growth by modulating multiple growth-regulatory pathways.

3-Phosphoinositide-Dependent Protein Kinases↗

PubMed2003

Tissue engineering of blood vessels with endothelial cells differentiated from mouse embryonic stem cells.

Endothelial cells (TEC3 cells) derived from mouse embryonic stem (ES) cells were used as seed cells to construct blood vessels. Tissue engineered blood vessels were made by seeding 8 106 smooth muscle cells (SMCs) obtained from rabbit arteries onto a sheet of nonwoven polyglycolic acid (PGA) fibers, which was used as a biodegradable polymer scaffold. After being cultured in DMEM medium for 7 days in vitro, SMCs grew well on the PGA fibers, and the cell-PGA sheet was then wrapped around a silicon tube, and implanted subcutaneously into nude mice. After 6~8 weeks, the silicon tube was replaced with another silicon tube in smaller diameter, and then the TEC3 cells (endothelial cells differentiated from mouse ES cells) were injected inside the engineered vessel tube as the test group. In the control group only culture medium was injected. Five days later, the engineered vessels were harvested for gross observation, histological and immunohistochemical analysis. The preliminary results demonstrated that the SMC-PGA construct could form a tubular structure in 6~8 weeks and PGA fibers were completely degraded. Histological and immunohistochemical analysis of the newly formed tissue revealed a typical blood vessel structure, including a lining of endothelial cells (ECs) on the lumimal surface and the presence of SMC and collagen in the wall. No EC lining was found in the tubes of control group. Therefore, the ECs differentiated from mouse ES cells can serve as seed cells for endothelium lining in tissue engineered blood vessels.

Animals↗

PubMed2003

Titin determines the Frank-Starling relation in early diastole.

Titin, a giant protein spanning half the sarcomere, is responsible for passive and restoring forces in cardiac myofilaments during sarcomere elongation and compression, respectively. In addition, titin has been implicated in the length-dependent activation that occurs in the stretched sarcomere, during the transition from diastole to systole. The purpose of this study was to investigate the role of titin in the length-dependent deactivation that occurs during early diastole, when the myocyte is shortened below slack length. We developed a novel in vitro assay to assess myocyte restoring force (RF) by measuring the velocity of recoil in Triton-permeabilized, unloaded rat cardiomyocytes after rigor-induced sarcomere length (SL) contractions. We compared rigor-induced SL shortening to that following calcium-induced (pCa) contractions. The RF-SL relationship was linearly correlated, and the SL-pCa curve displayed a characteristic sigmoidal curve. The role of titin was defined by treating myocytes with a low concentration of trypsin, which we show selectively degrades titin using mass spectroscopic analysis. Trypsin treatment reduced myocyte RF as shown by a decrease in the slope of the RF-SL relationship, and this was accompanied by a downward and leftward shift of the SL-pCa curve, indicative of sensitization of the myofilaments to calcium. In addition, trypsin digestion did not alter the relationship between SL and interfilament spacing (assessed by cell width) after calcium activation. These data suggest that as the sarcomere shortens below slack length, titin-based restoring forces act to desensitize the myofilaments. Furthermore, in contrast to length-dependent activation at long SLs, length-dependent deactivation does not depend on interfilament spacing. This study demonstrates for the first time the importance of titin-based restoring force in length-dependent deactivation during the early phase of diastole.

Actin Cytoskeleton↗

PubMed2003

A closer view of tissue engineering in China: the experience of tissue construction in immunocompetent animals.

Tissue engineering started in late 1980s and is now well established and progressing rapidly in Western developed countries. However, the development of tissue-engineering research in China remains relatively unknown to the international society of tissue engineering. Although involved in all areas of tissue-engineering research, including the creation of new scaffold materials, in vitro studies of seed cells, application of growth factors, and modification of seed cells and scaffold materials, China has put special emphasis on tissue construction in large mammalian animals in order to establish a solid scientific basis for clinical application of engineered tissues. To provide a closer view of tissue-engineering research in China, this article reviews our experience in tissue construction and tissue repair using immunocompetent animals such as sheep, pig, and dog as well as hen and rabbit. The engineered tissues include bone, cartilage, tendon, skin, blood vessels, cornea, and peripheral nerves.

Animals↗

PubMed2003

[Construction of recombinant pEGFP/hTRT plasmid].

OBJECTIVE: To construct a plasmid which has a reporter gene for exploring the role of human telomerase reverse transcriptase(hTRT) in in-vitro cell cultivation. METHODS: hTRT was cut by restricted enzyme from plasmid pGRN145 and inserted to plasmid pEGFP-C1 (enhanced green fluorescent protein). RESULTS: Restricted enzyme analysis and DNA sequencing showed that the sequence of the pEGFP -hTRT transgenic plasmid was correct. CONCLUSION: The recombinant vector pEGFP-hTRT has been successfully constructed, and it can be used as a transgenic plasmid in generating immortalized cell lines.

DNA-Binding Proteins↗

PubMed2003

Effect of adenovirus-mediated gene transfection of vascular endothelial growth factor on survival of random flaps in rats.

OBJECTIVE: To evaluate the effect of local application of vascular endothelial growth factor (VEGF) via adenovirus-mediated gene transfer on survival of full thickness flaps selected randomly in rats. METHODS: Thirty Sprague-Dawley rats weighing 480-520 g were used in this study. A dorsal flap (8 cm x 2 cm) in full thickness with the pedicle located at the level of the iliac crest was designed. Then the rats received 1,012 pfu replication-deficient recombinant adenovirus carrying VEGF (AdCMV-VEGF group, n=10), 1,012 pfu recombinant beta-galactosidase adenovirus (AdCMV-Gal group, n=10) and 1 ml saline (saline group, n=10), respectively, in the distal two thirds of the proposed flap by means of subdermal injection at 8 different locations. Three days after treatment, the flaps were elevated as originally designed and sutured back in situ. The survival rate of the flaps was evaluated on day 7 after operation. RESULTS: The survival rate of the flaps in the AdCMV-VEGF group increased significantly as compared with those of the AdCMV-Gal group (P<0.01) and the saline group (P<0.01). Immunohistochemical staining showed that VEGF was expressed in the survival flaps injected with AdCMV-VEGF. Histological analysis showed that more granulation tissues and angiogenesis were observed in the AdCMV-VEGF group than those in the AdCMV-Gal and the saline groups. CONCLUSIONS: Local application of adenovirus-mediated VEGF165 cDNA may efficiently improve the survival of ischemic skin flaps.

Adenoviridae↗