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Biomedical subjects

Hui Yang

Publications and source records attributed to Hui Yang.

At least 109 records · Page 6Linked to original sources
PubMed2004

[Gene therapy of tyrosine hydroxylase, aromatic L-amino acid decarboxylase, and GTP cyclohydrolase genes in rat model of Parkinson's disease].

OBJECTIVE: To detect the expression and function of enzyme genes involved in biosynthetic pathway for dopamine in vitro and assess their effect in rat model of Parkinson's disease. METHODS: Cos7 cells were transfected with separate adeno-associated virus (AAV) expressing tyrosine hydroxylase (TH) gene, aromatic L-amino acid decarboxylase (AADC) gene and GTP cyclohydrolase I (GCH-I) gene. The expression and function of the three genes were detected by methods of immunohistochemistry, in situ hybridization and high performance liquid chromatograph and electrochemical detection (HPLC-ECD). Gene engineered cells were sequentially transplanted into the striatum of 6-hydroxy-dopamine-leisioned Parkinsonian rat by stereotaxic instrastriatal injection. The asymmetric rotations of these rats after apomorphine administration were detected every week after transplantation. 10 weeks after grafting, the animals were sacrificed and the dopamine produced in the striatum was detected by HPLC-ECD. RESULTS: In vitro experiments showed that the three genes were high expressed in Cos7 cells. When Cos7 cells expressing TH, AADC and GCH-I were cocultured, they produced large amount of dopamine in the condition of existance of L-tyrosine. Furthermore, triple genes therapy resulted in greater dopamine production in the striatum of Parkinsonian rats and improved the rotational behavior of the rats more efficiently than did single gene therapy. However, the production of dopamine in the rats with triple genes therapy is no more than double genes therapy. CONCLUSION: For gene therapy in Parkinson's disease, the amount of target genes to be used should be determined by the level of doperminergic neurons damaged. In the present study, the efficiency of multiple genes therapy is significantly better than that of single gene therapy.

Animals↗
PubMed2004

Antisense Noggin oligodeoxynucleotide administration decreases cell proliferation in the dentate gyrus of adult rats.

The dentate gyrus of the hippocampus is one of few regions in the adult mammalian brain characterized by ongoing neurogenesis. It has been demonstrated that Noggin antagonizes bone morphogenetic protein-4 (BMP4) to create a niche for subventricular zone neurogenesis. We previously demonstrated that Noggin and BMP4 showed strong expression in the proliferative subgranular layer of the dentate gyrus in adult rats. To examine the action of Noggin on cell proliferation in the dentate gyrus of adult rats, we administered antisense oligodeoxynucleotide (ASODN) to Noggin by continuous infusion into the lateral ventricle of rats. Antisense-infused rats displayed significant reduction in number of bromodeoxyuridine (BrdU) labeled cells in the dentate gyrus. This indicated that endogenous Noggin activity is important for naturally occurring cell proliferation in the dentate gyrus, and perhaps neurogenesis, and is one of the many factors involved in its regulation.

Animals↗
PubMed2004

Investigation of compaction and sintering behavior of SiC powder after ultra-fine treatment.

Silicon carbide ceramics were prepared with SiC powder treated by the fluidized bed opposed jet mill as raw materials, and the effects of the ultra-fine treatment mechanism on the compaction and sintering behavior of SiC ceramics were investigated. The results showed that the compacts had higher density and microstructure homogeneity when the sintering temperature of the compact was decreased; and that the surface microstructure, densification and mechanical properties of the sintered body could be ameliorated obviously.

Carbon Compounds, Inorganic↗
PubMed2004

SVZa neural stem cells differentiate into distinct lineages in response to BMP4.

Neural stem cells (NSCs) reside in the anterior portion of the forebrain subventricular zone (SVZa) and generate the progenitors which will differentiate into neurons, and via a tangential migratory pathway, known as the rostral migratory stream (RMS), migrate to the olfactory bulbs (OB). Bone morphogenetic proteins (BMPs) play significant roles in neural development at different stages and locations, but their roles have not been determined in the SVZa. To explore possible roles of BMPs in SVZa NSCs, BMP4 at various concentrations were tested for their capacity to induce SVZa NSCs. The expression of BMP4 was also examined in living cells using a reportor vector, in which the BMP4 promotor was conjugated with red fluorescent protein (RFP). In the meantime, the differentiation of SVZa NSCs was dynamically monitored by using reportor vectors of the Nestin enhancer and the promoters of TH and GFAP. In the OB, high expression of BMP4 was found using both promoter activity analysis and in situ hybridization. However, low BMP4 expression was found in the RMS and only moderate expression of BMP4 was displayed in the SVZa. The results also demonstrated that low concentrations (1-5 ng/ml) of BMP4 promoted the proliferation of SVZa NSCs but high concentrations (10-100 ng/ml) of BMP4 inhibited this proliferation. BMP4 enhanced neuron commitment before 4 days but inhibited it after 4 days. As the antagonist of BMP4, Noggin almost completely blocked all these BMP4 responses. Thus, our findings indicate that BMP4 promotes the exit from the cell cycle and triggers the differentiation of neuron progenitors in the OB. BMP4 also promotes the proliferation of the committed neuron progenitors in the RMS, but in the SVZa, BMP4 may facilitate the commitment of NSCs into astrocytes.

Animals↗
PubMed2004

China's evolving health care market: how doctors feel and what they think.

This paper reports on a questionnaire survey and 12 focus groups conducted among doctors in three provinces of China, namely Guangdong, Shanxi, and Sichuan. The survey (N = 720) and focus group participants were drawn from both rural and urban areas, as well as public and private sectors, in equal numbers The aim was to gauge how Chinese doctors feel about themselves and what they think of the Chinese health care system. We found low satisfaction levels with own income (8%), job (27%), skill (30%), and other important aspects of their professional life. The health care system received only 32% approval rating. Quality of care and patient safety issues were major concerns, especially in the growing but poorly regulated private sector. The public sector came under criticism for its high fees and bad service quality. The feedback point to the need for an appropriate regulatory framework to guide the development of China's evolving health care market. A revitalized medical profession that is fully engaged in the reform process could also significantly impact the success of ongoing health care reform efforts.

Attitude of Health Personnel↗
PubMed2004

Expression and regulation of neuropilins and VEGF receptors by TNF-alpha in human endothelial cells.

BACKGROUND: Recently, neuropilins (NRPs) were identified as new VEGF receptors (VEGFRs) and VEGFR-3 was revealed to be implicated in angiogenesis besides in lymphangiogenesis. However, quantitative expression and regulation of NRPs and VEGFRs remain unclear. The objective of this study was to compare the expression of NRPs and VEGFRs and investigate their regulation by tumor necrosis factor (TNF-alpha) in human endothelial cells (ECs) as well as their roles in VEGF(165)-induced EC proliferation. MATERIALS AND METHODS: Human umbilical vein ECs (HUVECs) were treated with TNF-alpha (2 ng/ml) or PBS for 24 h. The mRNA and protein levels of NRP-1, NRP-2, VEGFR-1, VEGFR-2, and VEGFR-3 were semiquantitatively determined by real-time PCR and Western blot, respectively. Real-time PCR data were presented as the difference of reaction cycle thresholds (Ct) between beta-actin and each of the genes of interest (2(-DeltaCt)). EC proliferation in response to VEGF(165) (10 ng/ml) with or without anti-VEGFR-2 neutralization antibody pretreatment was analyzed by [(3)H]thymidine incorporation. RESULTS: In PBS-treated HUVECs, mRNA levels of NRPs and VEGFRs were NRP-1 (0.013), NRP-2 (0.007), VEGFR-2 (0.006), VEGFR-1 (0.0024), and VEGFR-3 (0.0009). After TNF-alpha treatment, mRNA levels of VEGFR-2, VEGFR-3, and NRP-1 were significantly reduced by 72, 65, and 53%, respectively (P < 0.05). The protein expression of all NRPs and VEGFRs were also detected by Western blot. TNF-alpha significantly reduced protein levels of VEGFR-2, VEGFR-3, and NRP-1 by 59, 35, and 22%, respectively. However, both mRNA and protein levels of VEGFR-1 and NRP-2 were not affected by TNF-alpha. Furthermore, TNF-alpha treatment significantly reduced EC proliferation in response to VEGF(165) by 67%. After blocking VEGFR-2 with neutralization antibody, TNF-alpha treatment elicited a 30% reduction of EC proliferation in response to VEGF(165). CONCLUSIONS: These data demonstrate that HUVECs express higher mRNA levels of NRP-1 and NRP-2 than those of VEGFRs, and TNF-alpha treatment significantly decreases the expression of VEGFR-2, VEGFR-3, and NRP-1, which may be responsible for TNF-alpha-induced reduction of EC proliferation in response to VEGF(165).

Cell Division↗
PubMed2004

[Clinical analysis of diplopia in 68 cases with orbital fractures].

PURPOSE: To explore the cause of orbital fracture associated with diplopia by summarizing 68 cases,in order to offer reference for clinical treatment. METHODS: 68 cases of orbital fracture associated with diplopia were examined by maxillofacial surgeon and oculist,by analyzing the CT and X-ray films of whom to make clear the reasons of diplopia. RESULTS: Of the 68 cases,male was more than female,vertical diplopia was dominant,and generally with the changes of the orbital structure. CONCLUSION: The main cause of diplopia is for the changes of orbital structures. The doctors must take it seriously and give the patients timely treatment.

Adolescent↗
PubMed2004

[Childhood and adolescent thyroid carcinoma: a clinical analysis of 86 cases].

OBJECTIVE: To investigate the clinico-pathologic characteristics, treatment and prognosis of thyroid carcinoma in childhood and adolescents. METHODS: From 1984 to 1997, 86 cases with thyroid carcinoma in childhood and adolescent treated were summarized. RESULTS: All cases underwent operation with adjuvant therapy. Pathologically, papillary carcinoma was diagnosed in 73 (84.9%), follicular carcinoma in 6 (7%), papillary-follicular carcinoma in 4 (4.7%) and medullary carcinoma in 3 (3.5%). Cervical lymph node metastasis was found in 59 cases (68.6%), 16 of which with both thyroid carcinoma and bilateral cervical lymph node metastasis (27.1%). Lung metastasis was found in 11 cases. Recurrence occurred in 6 cases after operation. Compared with the thyroid carcinoma in adult patients, cervical lymph node metastasis, bilateral involvement of the thyroid gland with bilateral cervical nodes and lung metastasis rate were more commonly seen in childhood and adolescence. All but 2 patients had been followed up for more than 5 years, 41 patients for more than 10 years. The 5-year and 10-year survival rate was 95.3% (82/86) and 87.8% (36/41), respectively. CONCLUSION: The clinical manifestations of childhood and adolescent thyroid cancer are generally not pathognostic which may lead to misdiagnosis. Surgery is the main method in the comprehensive treatment with a good prognosis. The therapy with (131)I after operation was beneficial for some patients accompanied with lung metastasis.

Adolescent↗
PubMed2004

[Detection of GABAA alpha 2 mRNA in rat cochlear spiral neuron with in situ hybridization].

OBJECTIVE: To investigate the expression of gamma-aminobutyric acid (GABA)A receptor alpha 2 subunit mRNA on rat cochlear spiral neurons and its' significance. METHODS: In the rat cochlear paraffin slides, the GABAA alpha 2 receptor in spiral ganglion neuron was detected with in situ hybridization. Digoxigenin-GABAA alpha 2 cDNA probe (549 base pair), anti-digoxigenin-AP(Fab fragments) and BM purple substrate(precipitating) were used. RESULTS: Positive signals(GABAA alpha 2 mRNA) were seen in all cochlear spiral neurons and their nerves. GABAA alpha 2 mRNA was not found in other structure such as bony spiral lamina. As a positive control, GABAA alpha 2 mRNA was seen in Purkinje cells, granule cells and their axons in rat's cerebellum. GABAA alpha 2 mRNA was not found in OMP cDNA probe (olfactory membrane estrogen receptor probe) negative control, non-probe negative control and non-anti-digoxingenin control in cochlear spiral neuron and cerebellum. CONCLUSION: GABAA alpha 2 receptor has been found in type I spiral neurons and their nerves. It strongly indicates that GABA as a nerve transmitter plays an important role in inhibiting the excessive stimulation transmission of the inner hair cells.

Animals↗
PubMed2004

[A study on the relationship between polymorphism of human NAD(P)H: quinone oxidoreductase and Parkinson's disease in Chinese].

OBJECTIVE: To detect the putative association between the polymorphism of human NAD(P)H: quinone oxidoreductase (NQO1) gene and Parkinson's disease(PD). METHODS: Polymerase chain reaction-denaturing high performance liquid chromatography (PCR-DHPLC) was used to detect the polymorphism of monoamine NQO1 gene cDNA 609 site(C-->T). The frequencies of alleles and genotypes in different PD groups were compared with those of the control group. RESULTS: It was found that the frequencies of TT genotype in the patients with PD and in the controls were 0.226 and 0.118 respectively (P=0.004), i.e., TT genotype increased the risk of PD by 2.186-fold (P=0.005). When the patients with PD were divided into two groups by the age at onset, significant difference in the genotypic frequencies was observed only between late-onset PD group and control group (the frequencies of TT genotype being 0.260 and 0.118, P=0.001) and TT genotype increased the risk of late-onset PD by 2.627-fold(P=0.001). There were no significant differences in frequencies of alleles between different PD groups and control group. CONCLUSION: This study revealed significant differences in genotypic frequencies between PD group and control group. The findings supported the hypothesis about an association between NQO1 gene and PD, suggesting that the age at onset of PD might be related to the putative association, and NQO1 cDNA C609T site be a risk factor for PD.

Adolescent↗
PubMed2004

[Changes of intestinal mucosal lymphocyte homing in rats with multiple organ dysfunction syndromes].

OBJECTIVE: To observe the changes of intestinal mucosal lymphocyte homing in rats with multiple organ dysfunction syndromes (MODS) and study the role of intestinal mucosal lymphocyte play in MODS. METHODS: A rat model of MODS was reproduced by occluding the superior mesenteric artery for 45 minutes followed by reperfusion for 6 hours. From the fifth hour after reperfusion, intestinal lymph of rats (MODS group 1, n=10) was collected for 1 hour. Intestinal lymph was also collected from rats of control group 1 (n=6). The population of lymphocytes and the percentage of T and B cells were measured in both groups. From the third hour after reperfusion, intestinal lymph of rats (MODS group 2, n=6) was collected for 2 hours. Then, intestinal lymphocytes were labeled with (51)Cr and were infused into blood circulation again at the sixth hour of reperfusion. Various organs were taken out 1 hour later for measurement of (51)Cr-lymphocytes distribution in organs by gamma-counter. Intestinal lymph of control rats (group 2, n=6) was collected. Labeled lymphocytes were also infused into blood circulation of rats again. RESULTS: The number of lymphocytes from intestinal mucosa migrated into blood circulation was decreased, the counts were (0.28+/-0.15)X10(7)/h and (2.69+/-0.61)X10(7)/h respectively, while 51 Cr-intestinal lymphocytes homed to intestinal mucosa were increased in MODS induced by intestine ischemia/reperfusion. At the same time, the levels of endotoxin and tumor necrosis factor-alpha (TNF-alpha) in intestinal lymph were also elevated. CONCLUSION: Increased homing of intestinal mucosal lymphocyte is involved in MODS of rats.

Animals↗
PubMed2004

[The influence of abnormally higher WBC on hemoglobin determination and its redress].

OBJECTIVE: To discuss the influence of abnormally higher white blood cell (WBC) on hemoglobin (Hb) determination and work for its redress. METHODS: High WBC concentration suspensions of 48 concentration gradients were prepared to be determined in the pre-dilution pattern of automated hematology analyzer while the changes of Hb concentration before and after removal of WBC being observed. At the same time, a regression equation was set up to correct errors and redress the Hb concentration. Then, the data from 14 whole blood samples with abnormally higher WBC were used in this regression equation to verify its utility. RESULTS: The Hb concentration of samples with abnormally higher WBC was higher than that of samples where WBC was removed (P<0.001). While WBC count > or = 40.0 x 10(9)/L, there was logarithmic linear correlation between Hb concentration difference and WBC count (r=0.9526). Using the regression equation Y (Hb difference) = -25.09 + 21.89 x lg[WBC (x 10(9)/L)], we found that there was no significant difference (P>0.05) between the "practically detected Hb difference" and the "theoretically adjusted Hb difference" in the whole blood samples with abnormally higher WBC. CONCLUSION: Abnormally higher WBC may lead to increase of error in the detection of Hb concentration; the ultimate result in close proximity to true Hb concentration of whole blood samples with abnormally higher WBC can be acquired through the linear regression equation.

False Positive Reactions↗
PubMed2004

[Effect of the combination of cadmium and UV-B radiation on soybean growth].

This paper studied the characteristics of soybean growth under the stress of Cd, UV-B radiation and their combination. The results showed that UV-B radiation gave a more pronounced inhibition on soybean growth than cadmium. Under UV-B radiation, the internode differentiation and elongation were inhibited, the internode and plant height were reduced, and the activities of SOD and POD had an apparent increase. Cd2+ could antagonize the effect of UV-B radiation on POD activity, and inhibit indole-3-acetic acid (IAA) oxidase activity. A significant decrease of POD and IAA oxidase activities in soybean was detected when exposed to combined UV-B and Cd2+, compared with UV-B radiation only. The decrease of POD and IAA oxidase activities was related to the increase of IAA contents and photosynthetic activity, which might account for the increases of biomass and plant height. Moreover, the combined stress enhanced the inhibition of root growth, and significantly decreased root length. The IAA oxidase and POD activities and photosynthesis rate might be the crucial factors determining the pattern of soybean growth under the stress of Cd2+ in combination with UV-B radiation.

Cadmium↗
PubMed2004

[Soluble expression of recombinant immunotoxin against human bladder carcinoma and its anti-tumor activity].

AIM: To construct soluble expression vector of the recombinant immunotoxin against human bladder carcinoma and express and purify the immunotoxin with high biological activity. METHODS: The gene fragment of the immunotoxin containing the genes encoding the humanized single-chain antibody against human bladder carcinoma and the truncated and modified form of Pseudomonas exotoxin(PE) named PE38/KDEL was digested from the plasmid pABDIT and inserted into the expression vector pTMFK containing the FkpA gene. The recombinant plasmid was used to transform the E.coli strain BL21(DE3)-Star and the immunotoxin was co-expressed with the FkpA which served as the folding assistant factor. The immunotoxin was purified through Ni-NTA agarose and anti-PEAb Sepharose 4B columns. The binding activity of the immunotoxin to the antigen on BIU-87 cells was detected by ELISA. The specific cytotoxic effect of the immunotoxin against BIU-87 cells was assessed by MTT colorimetry. RESULTS: The immunotoxin was over-expressed in soluble form in E.coli. The immunotoxin showed good binding activity to the membrane antigen on BIU-87 cells. The result of MTT assay demonstrated that purified recombinant immunotoxin could specifically kill BIU-87 cells. CONCLUSION: The immunotoxin was obtained with specific cytotoxicity to human bladder cancer cells, which lays the foundation for the further application of the immunotoxin in the target therapy of human bladder carcinoma.

ADP Ribose Transferases↗
PubMed2004

[Construction of tyrosine hydroxylase gene modified mesencephalic astrocytes].

OBJECTIVE: To construct tyrosine hydroxylase(TH) gene expressing mesencephalic astrocytes for the experiment of gene therapy for Parkinson's disease (PD). METHODS: The recombinant retroviral vector pN2ATH was constructed and transferred into PA317 pakaging cells by electroporation method. Resistant clones were obtained with G418 selective culture, and the virus supernatants were harvested. The mesencephalic astrocytes were cultured with the pN2ATH viral supernants. After 7-9 days culture, TH expression in the infected astrocytes were detected by immunohistochemistry. RESULTS: After G418 selection, high titer PA317/pN2ATH cells were obtained. The mesencephalic astrocytes transfected with pN2ATH succesfully expressed TH. CONCLUSION: Mesencephalic astrocytes transfected with pN2ATH can efficently express TH,which may provide a basis for further studies on gene therapy of PD in animals.

Animals↗
PubMed2004

[Expression pattern of profilin homologue in embryogenesis of amphioxus].

The expression pattern of profilin homologue in embryogenesis of amphioxus was characterized by whole-mount in situ hybridization combined serial histological sections and Northern blot. The results revealed that the dynamic expression pattern of the profilin homologue just accorded with muscle differentiating in this animal. It was most possibly involved in the development of muscle in amphioxus. The result of Southern blot supported that there was only one copy of profilin homologue in the genome of Qingdao amphioxus. It may be good for explaining the molecular mechanism of muscle differentiation in amphioxus.

Animals↗