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Dai C, Miao CX, Lu GX. ASCR-012 Characterization of the transcription factors for the CDCA8 promoter. Reprod Biomed Online 2008. [DOI: 10.1016/s1472-6483(10)61547-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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52
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Dai C, Mi W, Yang F, Chen B, Ding H, Shan Y. A novel inorganic–organic hybrid material: hydrothermal synthesis and properties of [V6O12(CH3O)4(phen)4·4H2O] (phen = 1,10-phenanthroline). J COORD CHEM 2007. [DOI: 10.1080/00958970500270836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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53
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Jenkins M, Zhu H, Dai C, Sithisack J, Chang Y, Zhu T. 349 FUNCTIONAL ANALYSIS OF THE HIV-1 ENVELOPE GENE ISOLATED FROM PURIFIED HUMAN T CELLS AND MONOCYTES. J Investig Med 2004. [DOI: 10.1136/jim-52-suppl1-349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Abramowitz J, Dai C, Hirschi KK, Dmitrieva RI, Doris PA, Liu L, Allen JC. Ouabain- and Marinobufagenin-Induced Proliferation of Human Umbilical Vein Smooth Muscle Cells and a Rat Vascular Smooth Muscle Cell Line, A7r5. Circulation 2003; 108:3048-53. [PMID: 14638550 DOI: 10.1161/01.cir.0000101919.00548.86] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
We studied the growth-promoting effects of 2 sodium pump–selective cardiotonic steroids, ouabain and marinobufagenin, on cultured cells from vascular smooth muscle (VSMCs) from human umbilical vein and a rat VSMC line, A7r5.
Methods and Results—
Both ouabain and marinobufagenin activated proliferation of these cells in a concentration-dependent manner, reflecting the cardiotonic steroid sensitivity of the specific α
1
subunit contained within each cell source. The observed effective concentration ranges of both compounds was below that necessary to induce cytoplasmic ion alterations by sodium pump inhibition.
Conclusions—
These data indicate that the ouabain-activated proliferative effect previously observed in canine VSMCs occurs in other VSMC sources. This growth effect seems to be initiated by drug interaction with the sodium pump, reflected by the affinity of the steroid for the pump, and is independent of altered transmembrane ionic gradients.
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Hirschi KK, Burt JM, Hirschi KD, Dai C. Gap junction communication mediates transforming growth factor-beta activation and endothelial-induced mural cell differentiation. Circ Res 2003; 93:429-37. [PMID: 12919949 DOI: 10.1161/01.res.0000091259.84556.d5] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
During blood vessel assembly, endothelial cells recruit mesenchymal progenitors and induce their differentiation into mural cells via contact-dependent transforming growth factor-beta (TGF-beta) activation. We investigated whether gap junction channels are formed between endothelial cells and recruited mesenchymal progenitors and whether intercellular communication is necessary for endothelial-induced mural cell differentiation. Mesenchymal progenitors from Cx43-/- murine embryos and Cx43+/+ littermates were cocultured with prelabeled endothelial cells. Intracellular dye injection and dual whole-cell voltage clamp revealed that endothelial cells formed gap junction channels with Cx43+/+ but not Cx43-/- progenitors. In coculture with endothelial cells, Cx43-/- progenitors did not undergo mural cell differentiation as did Cx43+/+ cells. Stable reexpression of Cx43 in Cx43-/- cells (reCx43) restored their ability to form gap junctions with endothelial cells and undergo endothelial-induced mural cell differentiation. Cocultures of endothelial cells and either Cx43+/+ or reCx43 mesenchymal cells produced activated TGF-beta; endothelial-Cx43-/- cocultures did not. However, Cx43-/- cells did produce latent TGF-beta and undergo mural cell differentiation in response to exogenous TGF-beta1. These studies indicate that gap junction communication between endothelial and mesenchymal cells mediates TGF-beta activation and subsequent mural cell differentiation.
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Zhang G, Dai C. Gene polymorphisms of homocysteine metabolism-related enzymes in Chinese patients with occlusive coronary artery or cerebral vascular diseases. Thromb Res 2001; 104:187-95. [PMID: 11672761 DOI: 10.1016/s0049-3848(01)00352-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The mutations in homocysteine (Hcy) metabolism-related enzyme genes including methylenetetrahydrofolate reductase (MTHFR) C677T, cystathionine beta-synthase (CBS) 844ins68, and methionine synthase (MS) A2756G have been identified as genetic risk factors for thromboembolic events. It has been noticed that these gene mutations have heterogeneous distributions among different ethnic groups or geographic areas. The data on the prevalence of the gene mutations in Chinese population is not yet available. In the present study, we have investigated the frequency of the MTHFR C677T, CBS 844ins68, and MS A2756G mutations in 102 patients with ischemic stroke (IS), 73 patients with myocardial infarction (MI) and 100 healthy controls. The distributive frequencies of the gene variations are as follows: In the IS, MI and control groups, the mutant homozygote for MTHFR C677T is 15 (14.7%), 8 (11.7%) and 16 (16.0%), respectively, and the T allele frequency is 37.7%, 33.6% and 39.5%, respectively; the heterozygote for CBS 844ins68 is 1 (1.0%), 1 (1.4%) and 5 (5.0%), respectively; the heterozygote for MS A2756G is 18 (17.6%), 14 (19.2%) and 17 (17.0%), and the G allele frequency is 8.8%, 11.0% and 9.5%, respectively. The carrier of both MS A2756G and MTHFR C677T (combined mutations) is 14 (12.7%), 8(11.0%) and 12(12.0%), respectively. There is no statistically significant difference between the patient groups and the control group in the frequencies of these single mutation or combined mutations. The heterozygosity of CBS 844ins68 yields an odds ratio (OR) of 0.19 (95% confidence interval (CI) 0.02-1.43) for IS and 0.26 (95% CI 0.03-2.31) for MI. The T allele of MTHFR C677T yields an OR of 0.93 for IS (95% CI 0.62-1.39) and 0.77 for MI (95% CI 0.50-1.21). The G allele of MS A2756G yields an OR of 0.92(95% CI 0.47-1.81) for IS and 1.17 (95% CI 0.58-2.37) for MI. Our results suggest that neither single mutation nor combined mutations in MTHFR C677T, CBS 844ins68 and MS A2756G represent an independent risk factor for increasing IS and coronary artery disease risks in Chinese population. However, CBS 844ins68 may be a protective factor against vascular thromboembolic disease. The prevalence of CBS 844ins68 and MS A2756G in Chinese population is obviously lower than in Western Caucasian population.
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Dai C, Wang W, Cao Y. [An experimental study of repairing nerve gap with acellular basal lamina tubes]. ZHONGHUA ZHENG XING WAI KE ZA ZHI = ZHONGHUA ZHENGXING WAIKE ZAZHI = CHINESE JOURNAL OF PLASTIC SURGERY 2001; 17:366-8. [PMID: 11838065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To develop an effective new material for repair of nerve defects. METHODS The 4-week pre-degenerative and normal sciatic nerve segments of SD rats were extracted with the detergent lysophosphatidylcholine, which resulted in acellular nerve basal lamina tubes, called EDNG (extracted degenerative nerve grafts) and ENG (extracted normal nerve grafts) respectively. The morphology of the acellular nerve basal lamina tubes was revealed by conventional histological examinations, transmission electron microscopy and immunohistochemistry method. The basal lamina tubes, as allografts, were used to repair a 15 mm-gap of sciatic nerve in Wistar rats. In the control group nerve autografts (NAG) was applied. Evaluation included general observation, electromyographic examination, muscle measurement and histological observation of serial sections at 12 weeks after surgery. RESULTS The EDNG had more ideal frame, better resilience than ENG. There was no any cell debris in EDNG, whereas in the inner wall of the tubes immunohistochemical analysis revealed clear positive staining and strong immunoreactivity of laminin under immunoelectron microscopy. After peripheral nerves were repaired, all the animals of the three groups had restoration of function to a certain extent. The result of the NAG group was the best, the EDNG group was the next and the ENG group was the inferior. CONCLUSION This new material offers a possible solution to repair of a short defect of a peripheral nerve.
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Netherton MR, Dai C, Neuschütz K, Fu GC. Room-temperature alkyl-alkyl Suzuki cross-coupling of alkyl bromides that possess beta hydrogens. J Am Chem Soc 2001; 123:10099-100. [PMID: 11592890 DOI: 10.1021/ja011306o] [Citation(s) in RCA: 355] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Yang J, Dai C, Liu Y. Systemic administration of naked plasmid encoding hepatocyte growth factor ameliorates chronic renal fibrosis in mice. Gene Ther 2001; 8:1470-9. [PMID: 11593360 DOI: 10.1038/sj.gt.3301545] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2001] [Accepted: 07/05/2001] [Indexed: 11/08/2022]
Abstract
The progression of chronic renal diseases is considered as an irreversible process that eventually leads to end-stage renal failure characterized by extensive tissue fibrosis. At present, chronic renal fibrosis is incurable and the incidence of affected patients is on the rise worldwide. In this study, we demonstrate that delivery of hepatocyte growth factor (HGF) gene via systemic administration of naked plasmid vector markedly ameliorated renal fibrosis in an animal model of chronic renal disease induced by unilateral ureteral obstruction. A high level of exogenous HGF protein was detected in the obstructed kidneys following intravenous injection of naked plasmid encoding human HGF. Delivery of human HGF gene induced a sustained activation of extracellular signal-regulated kinases-1 and -2 in the obstructed kidneys. Exogenous HGF expression dramatically inhibited alpha-smooth muscle actin expression, attenuated renal interstitial accumulation and deposition of collagen I and fibronectin. In addition, exogenous HGF suppressed renal expression of pro-fibrogenic cytokine TGF-beta1 and its type I receptor in vivo. These results suggest that systemic administration of naked plasmid vector introduces a high level of exogenous HGF to the diseased kidneys, and that HGF gene transfer may provide a novel therapeutic strategy for amelioration of chronic renal fibrosis in vivo.
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Dai C, Zhang G. [Study on homocysteine metabolism related enzymes gene mutations in Chinese patients with ischemic cardiovascular and cerebrovascular diseases]. ZHONGHUA XUE YE XUE ZA ZHI = ZHONGHUA XUEYEXUE ZAZHI 2001; 22:484-7. [PMID: 11758232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To explore the significance of gene mutations of cystathionine beta-synthase (CBS844ins68), methionine synthase (MS A2756G) and methylenetetrahydrofolate reductase (MTHFR C677T) in ischemic cardiovascular and cerebrovascular diseases. METHODS The genotypes of CBS 844ins68, MS A2756G and MTHFR C677T were determined by PCR-based assay in 102 patients with brain infarction, 73 with myocardial infarction and 100 healthy controls. RESULTS The prevalences of CBS 844ins68 and MS A2756G in the cohort studied were somewhat lower than that in western Caucasian populations. There were no significant differences in the frequencies of CBS 844ins 68, MS A2756G and MTHFR C677T mutations between the patient the and control groups. However, the heterozygous form of CBS 844ins 68 tended to be more prevalent in the controls than in the patients. CONCLUSION Gene mutations as CBS 844ins 68, MS A2756G and MTHFR C677T may not be independent risk factors for ischemic cardiovascular and cerebrovascular disease in Southern Chinese Han population. The prevalences of CBS 844ins 68 and MS A2756G may vary with different ethnic groups or geographic regions.
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Sun M, Zan Y, Ma Y, Zhang G, Du Q, Dai C. Expression and glycosylation of rotavirus strain SA11 VP4 protein in a recombinant adenovirus. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 2001; 16:129-34. [PMID: 12899323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
OBJECTIVE Using a recombinant human adenovirus to express modified VP4 gene of rotavirus SA11 strain. METHODS A whole VP4 gene was obtained with PCR and induced the signal peptide at the gene N terminal. The chimera gene was cloned into pCMV plasmid that consists of human cytomegalovirus promoter, and then the gene was cloned to the transfer vector of human adenovirus type 5. Homologous recombination was performed by co-transfection to 293 cell lines with recombinant plasmid and viral genome using CaPO4 precipitation. RESULTS No mutation was found in the whole VP4 gene sequence of 2362 base pair. The expressed product in recombinant adenovirus was confirmed to be specific and more antigenicity by indirect immunofluorescence assay. Both the Western blot and immunoprecipitation assay showed that the molecular mass of the expressed protein was higher than the wild type VP4 protein, and that the modified product was corresponding to a glycosylation of VP4 protein. CONCLUSION To modify the target gene might be an effective method to enhance the stability, antigenicity and immunogenicity of expressed protein.
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Abstract
Gliomas are primary central nervous system tumors that arise from astrocytes, oligodendrocytes or their precursors. Gliomas can be classified into several groups according to their histologic characteristics, the most malignant of the gliomas is glioblastoma multiforme. In contrast to the long-standing and well-defined histopathology, the underlying molecular and genetic bases for gliomas are only just emerging. Many genetic alterations have been identified in human gliomas, however, establishing unequivocal correlation between these genetic alterations and gliomagenesis requires accurate animal models for this disease. Here we are reviewing the existing animal models for gliomas with different strategies and our current knowledge on the important issues about this disease, such as activation of signal transduction pathways, disruption of cell cycle arrest pathways, cell-of-origin of gliomas, and therapeutic strategies.
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Dai C, Liu Z, Zhou H, Li L. Monocyte chemoattractant protein-1 expression in renal tissue is associated with monocyte recruitment and tubulo-interstitial lesions in patients with lupus nephritis. Chin Med J (Engl) 2001; 114:864-8. [PMID: 11780369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
OBJECTIVE To investigate the pattern of monocyte chemoattractant prolein-1 (MCP-1) distribution in the renal interstitium and evaluate its pathogenic role in tubulo-interstitial lesions in patients with lupus nephritis, the distribution of MCP-1 in renal tissue was observed. METHODS Eighteen female patients with biopsy-proven lupus nephritis were enrolled in this study. No intensive immunosuppresive therapy was used in these patients during the 3 months prior to renal biopsy. The distribution of MCP-1, infiltration of CD68+ (macrophage/monocyte), CD4+ and CD8+ cells in the tubulo-interstitium of patients with lupus nephritis was detected using immunohistochemical staining with specific antibodies. Renal specimens from patients with minimal change glomerulonephritis were used as controls. RESULTS MCP-1 protein was widely distributed in the renal tissue of patients with lupus nephritis, mainly located at the baso-lateral surface of tubular epithelial cells (16/18 biopsies), and on the wall of interstitial blood vessels (9/18 biopsies). In contrast, tubular MCP-1 staining was weak and rare in renal tissue from controls (7.4 +/- 6.2% vs 26.7 +/- 22.8%, P < 0.01). Tubulo-interstitial infiltration of CD68+, CD4+ and CD8+ cells was markedly increased in patients with lupus nephritis as compared to controls. The tubular expression of MCP-1 was strongly associated with the amount of CD68+ cell infiltration in the interstitium (r = 0.5420, P < 0.05) and the extent of interstitial fibrosis. There was no correlation between MCP-1 production in tubules and the degree of urinary protein excretion in patients with lupus nephritis (r = 0.0547, P > 0.05). CONCLUSIONS The expression of MCP-1 in the renal tubules and vascular wall was markedly increased in patients with lupus nephritis. The overproduction of MCP-1 in renal tissue may contribute to monocyte recruitment in the interstitium and thus result in tubulo-interstitial damage in lupus nephritis.
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Dai C, Celestino JC, Okada Y, Louis DN, Fuller GN, Holland EC. PDGF autocrine stimulation dedifferentiates cultured astrocytes and induces oligodendrogliomas and oligoastrocytomas from neural progenitors and astrocytes in vivo. Genes Dev 2001; 15:1913-25. [PMID: 11485986 PMCID: PMC312748 DOI: 10.1101/gad.903001] [Citation(s) in RCA: 508] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We present evidence that some low-grade oligodendrogliomas may be comprised of proliferating glial progenitor cells that are blocked in their ability to differentiate, whereas malignant gliomas have additionally acquired other mutations such as disruption of cell cycle arrest pathways by loss of Ink4a-Arf. We have modeled these effects in cell culture and in mice by generating autocrine stimulation of glia through the platelet-derived growth factor receptor (PDGFR). In cell culture, PDGF signaling induces proliferation of glial precursors and blocks their differentiation into oligodendrocytes and astrocytes. In addition, coexpression of PDGF and PDGF receptors has been demonstrated in human gliomas, implying that autocrine stimulation may be involved in glioma formation. In this study, using somatic cell type-specific gene transfer we investigated the functions of PDGF autocrine signaling in gliomagenesis by transferring the overexpression of PDGF-B into either nestin-expressing neural progenitors or glial fibrillary acidic protein (GFAP)-expressing astrocytes both in cell culture and in vivo. In cultured astrocytes, overexpression of PDGF-B caused significant increase in proliferation rate of both astrocytes and neural progenitors. Furthermore, PDGF gene transfer converted cultured astrocytes into cells with morphologic and gene expression characteristics of glial precursors. In vivo, gene transfer of PDGF to neural progenitors induced the formation of oligodendrogliomas in about 60% of mice by 12 wk of age; PDGF transfer to astrocytes induced the formation of either oligodendrogliomas or mixed oligoastrocytomas in about 40% of mice in the same time period. Loss of Ink4a-Arf, a mutation frequently found in high-grade human gliomas, resulted in shortened latency and enhanced malignancy of gliomas. The highest percentage of PDGF-induced malignant gliomas arose from of Ink4a-Arf null progenitor cells. These data suggest that chronic autocrine PDGF signaling can promote a proliferating population of glial precursors and is potentially sufficient to induce gliomagenesis. Loss of Ink4a-Arf is not required for PDGF-induced glioma formation but promotes tumor progression toward a more malignant phenotype.
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MESH Headings
- Animals
- Animals, Newborn
- Astrocytes/cytology
- Astrocytes/drug effects
- Astrocytoma/genetics
- Astrocytoma/pathology
- Becaplermin
- Brain/cytology
- Brain Neoplasms/genetics
- Brain Neoplasms/pathology
- Cell Cycle/drug effects
- Cell Cycle/physiology
- Cell Differentiation/drug effects
- Cell Division
- Cell Transformation, Neoplastic
- Cells, Cultured
- Glial Fibrillary Acidic Protein/analysis
- Glial Fibrillary Acidic Protein/genetics
- Humans
- In Situ Hybridization, Fluorescence
- Intermediate Filament Proteins/genetics
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred Strains
- Mice, Transgenic
- Nerve Tissue Proteins
- Nestin
- Oligodendroglioma/genetics
- Oligodendroglioma/pathology
- Platelet-Derived Growth Factor/pharmacology
- Promoter Regions, Genetic
- Proto-Oncogene Proteins c-sis
- Receptors, Platelet-Derived Growth Factor/physiology
- Recombinant Proteins/pharmacology
- Stem Cells/cytology
- Stem Cells/drug effects
- Transfection
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Abstract
The retinoblastoma (Rb), cyclin-dependent kinase (CDK), and CDK inhibitor genes regulate cell generation, and deregulation can produce increased cell growth and tumorigenesis. Polycythemia vera (PV) is a clonal myeloproliferative disease where the mechanism producing increased hematopoiesis is still unknown. To investigate possible defects in cell-cycle regulation in PV, the expression of Rb and CDK inhibitor gene messenger RNAs (mRNAs) in highly purified human erythroid colony-forming cells (ECFCs) was screened using an RNase protection assay (RPA) and 11 gene probes. It was found that RNA representing exon 2 of p16INK4a and p14ARF was enhanced by 2.8- to 15.9-fold in 11 patients with PV. No increase of exon 2 mRNA was evident in the T cells of patients with PV, or in the ECFCs and T cells from patients with secondary polycythemia. p27 also had elevated mRNA expression in PV ECFCs, but to a lesser degree. Because the INK4a/ARF locus encodes 2 tumor suppressors, p16INK4a and p14ARF with the same exon 2 sequence, the increased mRNA fragment could represent either one. To clarify this, mRNA representing the unique first exons of INK4a and ARF were analyzed by semiquantitative reverse transcription–polymerase chain reaction. This demonstrated that mRNAs from the first exons of both genes were increased in erythroid and granulocyte-macrophage cells and Western blot analysis showed that the INK4a protein (p16INK4a) was increased in PV ECFCs. Sequencing revealed no mutations of INK4a or ARF in 10 patients with PV. p16INK4a is an important negative cell-cycle regulator, but in contrast with a wide range of malignancies where inactivation of theINK4a gene is one of the most common carcinogenetic events, in PV p16 INK4a expression was dramatically increased without a significant change in ECFC cell cycle compared with normal ECFCs. It is quite likely that p16INK4a and p14ARF are not the pathogenetic cause of PV, but instead represent a cellular response to an abnormality of a downstream regulator of proliferation such as cyclin D, CDK4/CDK6, Rb, or E2F. Further work to delineate the function of these genes in PV is in progress.
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Wang Z, Dai C, Zhang Y. Experimental study on facial nerve regeneration with or without geniculate ganglionectomy. ARCHIVES OF OTOLARYNGOLOGY--HEAD & NECK SURGERY 2001; 127:422-5. [PMID: 11296052 DOI: 10.1001/archotol.127.4.422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To investigate regeneration of the distal facial nerve following nerve grafting within the tympanic segment with geniculate ganglion preservation or dissection. DESIGN Randomized controlled trial. SUBJECTS Twenty-three adult New Zealand albino rabbits were used in this study. INTERVENTIONS A 2-mm tympanic segment of the facial nerve was removed, and the greater auricular nerve was harvested for grafting in all animals. In group 1 (10 rabbits), the geniculate ganglion was preserved. In group 2 (13 rabbits), the geniculate ganglion was dissected. Mastoidal and extratemporal segments of the facial nerve were harvested 3 months postoperatively for histological examination by electron microscopy. RESULTS The number of myelinated axons in normal facial nerves was 1819.6 +/- 535.6. In group 1, the number of myelinated axons was 123.6 +/- 31.1, and, compared with normal facial nerves, the diameter of the regenerative axons was decreased and the sheath thickness in the regenerative fiber was diminished. In group 2, the number of myelinated axons was 515.1 +/- 103.1, while the myelin sheath thickness was proportionate to axon diameter. (Data are given as mean +/- SD.) CONCLUSION Geniculate ganglionectomy may improve motor axon regeneration.
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Dai C, Fu GC. The first general method for palladium-catalyzed Negishi cross-coupling of aryl and vinyl chlorides: use of commercially available Pd(P(t-Bu)(3))(2) as a catalyst. J Am Chem Soc 2001; 123:2719-24. [PMID: 11456957 DOI: 10.1021/ja003954y] [Citation(s) in RCA: 349] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
With a single protocol, commercially available Pd(P(t-Bu)(3))(2) can effect the Negishi cross-coupling of a wide range of aryl and vinyl chlorides with aryl- and alkylzinc reagents. The process tolerates nitro groups, and it efficiently generates sterically hindered biaryls. In addition, a high turnover number (>3000) can be achieved.
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Wang J, Dai C, Liu S, Wang S, Dong H, Xie K. [Effects of blood transfusion on cellular immuno-function in patients with laryngeal carcinoma]. LIN CHUANG ER BI YAN HOU KE ZA ZHI = JOURNAL OF CLINICAL OTORHINOLARYNGOLOGY 2001; 15:103-5. [PMID: 12541675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To explore the influence of blood transfusion on cellular immunofunction in patient with laryngeal carcinoma. METHOD EPICS-XL flow cytometry was used to measure T cell subgroup, NK cell and CD28 in 36 patients with laryngeal carcinoma pre-operation and 2 weeks post-operation. Patients were divided into allotransfusion group and non-transfusion group. Comparison was conducted between the 2 groups. RESULT 1. Comparison with normal population, decreasing of CD3, CD4, NK cell and CD28 in the 36 patients pre-operation was statistically significant (P < 0.01). 2. Decreasing of CD3, CD4, NK cell and CD28 was statistically significant post-operation (P < 0.05). 3. In the non-transfusion group change of CD3, CD4, CD8, NK cell and CD28 post-operation was statistically insignificant (P > 0.05). CONCLUSION While cellular immunofunction is generally low in patients with laryngeal carcinoma, allotransfusion will reduce further. It makes contribution to spreading and metastasis of carcinoma easier.
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Dai C, Huang X, Zhao H, Wang Z, Li K. [Expression of bcl-2 in facial motoneurons and its ultrastructural localization following facial nerve injury]. ZHONGHUA ER BI YAN HOU KE ZA ZHI 2001; 36:10-3. [PMID: 12761898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
OBJECTIVE To explore the expression of bcl-2 in facial motoneurons and its subcellular distribution. METHODS Wistar rats were used in this study. Facial nerve transection was performed at stylomastoid foramen or internal acoustic meatus. Facial nerve crush was made at stylomastiod foramen. The animal survived for 1, 3, 7, 15, 30 and 60 days respectively. Facial nucleus was treated with bcl-2 monoclonal antibody or bcl-2 DIG-labelling probe and studied with immunohistochemistry and in situ hybridization. The bcl-2 positive motoneuron was investigated with immuno-electron microscope. RESULTS It was demonstrated that bcl-2 protein level was corresponded with bcl-2 mRNA expression. The level of bcl-2 expression in facial motoneurons was high in normal facial nerve. It increased on the first day and declined on the third day post-transection in facial motoneuron. It reached the lowest level on the 15th days following facial nerve injury (P < 0.05). The expression recovered to normal level in two months (P > 0.05). After facial nerve transected, the reduction of bcl-2 expression was more significant when facial nerve transected close to facial nucleus than that far from facial nucleus (P < 0.05). Comparing to facial nerve transection in stylomastoid foramen, there was more intensive bcl-2 expression following facial nerve crush (P < 0.05). Further study showed that bcl-2 primarily resided in the nuclear envelop, endoplasmic reticulum and mitochondrial membrane. CONCLUSIONS These data indicated that high level bcl-2 protein may prevent facial motoneuron death following facial nerve injury. It is suggested that overexpression bcl-2 by transgene may prevent facial motoneurons death.
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Dai C, Yuan S, Li X, Liu J, Xing D, Lu L. [The effect of culture conditions on the fatty acid composition in the mycelium of the Cephalosporium sp]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 2001; 41:87-93. [PMID: 12549195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
The optimal condition of Cephalosporium sp. to culture mycelia and accumulate polyunsaturated fatty acid (PUFA) was researched. The optimal culture condition to get mycelium productivity was: maltose 60 g/L, KNO3 3 g/L, initial pH 6.0, 100 mL medium in 500 mL flask, seeding 25% (v/v), 25 degrees C culture it for 10 days. The optimal condition to accumulation PUFA proportion to total fatty acid was: glucose 10-20 g/L, NH4Cl or (NH4)2SO4 3 g/L, initial pH 4.0, 100 mL medium in 500 mL falsk, seeding 10-20% (v/v) and lighted it when it was cultured. It was suggested that two step could be used in the producing progress. A proposal was put forward that the oileic acid transformed to linoleic acid was the key step to produce PUFA. This proposal gave a base to research the optimal culture condition and enzyme regulation.
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Huang X, Dai C, Wang Z. [Facial paralysis in temporal bone trauma]. ZHONGHUA ER BI YAN HOU KE ZA ZHI 2001; 36:34-7. [PMID: 12761905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
OBJECTIVE To study the cause and treatment of facial paralysis in temporal bone trauma. METHODS A retrospective review of 28 patients with facial paralysis resulting from temporal bone trauma was conducted, House-Brackmann(H-B) system was used to evaluate the recovery of facial nerve function, U test was employed for statistic analysis. RESULTS Twenty-six cases underwent following up facial nerve function of all patients was recovery partly after surgery, 46% cases reached H-B II, 84% cases reached H-B III, comparing facial nerve decompression within 4 months of injury to beyond 4 months of injury, recovery to H-B II or more of facial nerve function was 60% and 0%, respectively. The difference was significant(P < 0.05). CONCLUSION Surgery decompression is effective on facial nerve palsy caused by temporal bone trauma. It is recommended that surgery decompression be carried out as soon as possible since a better prognosis is obtained if it is performed within four months after injury.
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Li J, Zhou X, Dai C, Zhang P. [Establishment of a GC and GC/MS method for analysis of fatty acids in human dental plaque]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2000; 18:386-8. [PMID: 12539466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To study the composition of fatty acids in human dental plaque, a Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GC/MS) method was developed. METHODS The C17:0 was internal standard and the C16:0 was test standard. Samples of plaque were methanolysis to be fatty acids methyl ester before detection. GC with OV-1 separated the sample for a quantitative analysis. The column size was 25 m x 25 mm. The temperature program was from 80 degrees C to 260 degrees C with 12 degrees C/min. The sample separation was carried out at fused silica capillary column with OV-1 for qualitative analysis by GC/MS. The column size was 23 m x 0.23 mm. The temperature program was from 40 degrees C to 240 degrees C at 6 degrees C/min. RESULTS The linear regression equation was y = 0.0138X-0.1182, r = 0.9945, recovery was 90.18%-103.6%, CV intro-day was 2.60, 1.61, 2.20; CV inter-day was; 2.71, 1.69, 1.61. The lowest limit of detection was 0.6 ug. The GC and GC/MS diagram showed that internal standard and fatty acids of plaque have good separation. CONCLUSION The method is simple, rapid accurate, and is useful to carry out qualitative and quantitative analyses of fatty acids in dental plaque.
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Tang H, Ma Y, Li C, Du R, Le G, Zhuang J, Liu Y, Sun M, Dai C. [Construction of plasmids expressing hepatitis E virus antigen fragments and their combinations]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 2000; 22:562-5. [PMID: 12903405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
OBJECTIVE Several different regions of the HEV antigen were expressed in Escherichia coli and their immunological characteristics were simply evaluated. METHODS Three coding sequences of immunodominant antigenic regions in structural protein of the hepatitis E virus (ORF2.1: 6287-6403nt, ORF2.2: 6743-7126nt, ORF3: full length of ORF3) were amplified by RT-PCR from the fecal supernatants of macaques experimentally infected with HEV. These three fragments were inserted into the pThioHisC expression vector separately or fused in line by (Gly)n short arms. After identified by DNA sequence analysis, these six recombinant plasmids were transformed into Escherichia coli, and immunology characteristics of expressed antigen fragments were evaluated by Western blotting. RESULTS All six genes were successfully expressed in Escherichia coli. Western blotting assay showed that the recombinant proteins specifically reacted with the serum antibody from hepatitis E patient in various degrees. CONCLUSION Artificial antigen based on strung epitopes provides a promising strategy for detection and prevention of HEV infection.
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Dai C, Liu X. [Effects of epidermal growth factor on wound healing of penetrating keratoplasty in rabbits]. YAN KE XUE BAO = EYE SCIENCE 2000; 16:228-30, 223. [PMID: 12579775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To observe the effects of epidermal growth factor (EGF) on wound healing of the penetrating keratoplasty(PKP) in rabbits. METHODS Twelve rabbits (24 eyes) were stratified randomly divided into 6 groups and underwent penetrating keratic autoplasy. Liquid scintillation counter was used to measure the incorporation rate of 3H-TdR. Pressure-detector was used to survey the intensity of keratic wound healing. AgNORs staining was used to count the fibroblast cells at keratic wound. HE staining, VG staining, AgNORs staining and transmission electron microscopy were used to observe the morphological changes of keratic wound. RESULTS 1 The intensity of EGF group on 8 days, 14 days and 21 days after PKP was significantly higher than that of the control group(P < 0.01). 2. The incorporation rate of 3H-TdR in wound healing the EGF group on 14 days and 21 days was obviously higher than that of the control group(P = 0.01). 3. The number of fibroblast cells of EGF were more than that of the control group(P < 0.01) in 8 days. CONCLUSION EGF can promote the wound healing in rabbits after PKP.
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Holland EC, Li Y, Celestino J, Dai C, Schaefer L, Sawaya RA, Fuller GN. Astrocytes give rise to oligodendrogliomas and astrocytomas after gene transfer of polyoma virus middle T antigen in vivo. THE AMERICAN JOURNAL OF PATHOLOGY 2000; 157:1031-7. [PMID: 10980141 PMCID: PMC1885688 DOI: 10.1016/s0002-9440(10)64615-9] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The cells of origin for oligodendrogliomas and astrocytomas are not known but are presumed to be oligodendrocyte and astrocyte precursors, respectively. In this paper we report the generation of mixed gliomas from in vivo transformation of glial fibrillary acidic protein (GFAP)-positive cells (differentiated astrocytes) with polyoma virus middle T antigen (MTA). MTA is a powerful oncogene that activates a number of signal transduction pathways, including those proposed to be involved in gliomagenesis, and has been shown to induce tumors in many cell types. We have achieved transfer of MTA expression specifically to GFAP(+) cells in vivo using somatic cell gene transfer, and find resultant formation of anaplastic gliomas with mixed astrocytoma and oligodendroglioma morphological features. We conclude that GFAP- expressing astrocytes, with appropriate signaling abnormalities, can serve as the cell of origin for oligodendrogliomas, astrocytomas, or mixed gliomas.
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