Biomedical subjects

Zhao-hui Sun

Publications and source records attributed to Zhao-hui Sun.

16 recordsLinked to original sources

PubMed2006

MEK inhibitor PD98059 acutely inhibits synchronized spontaneous Ca2+ oscillations in cultured hippocampal networks.

AIM: To investigate the changes in synchronized spontaneous Ca2+ oscillations induced by mitogen-activated protein kinase kinase (MEK) inhibitor PD98059 at different concentrations in cultured hippocampal network. METHODS: Hippocampal neurons in culture for 1-2 weeks were used for this study. Spontaneous synaptic activities of these hippocampal neurons were examined by Ca2+ imaging using calcium-sensitive dye. MEK inhibitor PD98059 (10, 30, and 60 micromol/L) and SB202474 (10 and 60 micromol/L), a negative control for mitogen-activated protein kinase (MAPK) cascade study, were applied to the cells under the microscope while imaging was taking place. RESULTS: PD98059 at a lower concentration of 10 micromol/L had little effect on the Ca2+ oscillation. At the higher concentration of 30 micromol/L, 5 min after application of PD98059, the spike frequency was decreased to 25.38% +/-7.40% (mean+/-SEM, n=16, P<0.01 vs medium control) of that of the control period. At an even higher concentration of 60 micromol/L, 5 min after application of PD98059, the spike frequency was decreased to 14.53%+/-5.34% (mean+/-SEM, n=16, P< 0.01 vs medium control) of that of the control period. The spike amplitude underwent a corresponding decrease. However, the negative control SB202474 at concentrations of 10 and 60 micromol/L had little inhibition effect on the Ca2+ oscillation. CONCLUSION: These results indicate that PD98059 inhibits synchronized spontaneous Ca2+ oscillation through inhibition of MEK, which hints that the MAPK cascade is required to maintain synchronized spontaneous Ca2+ oscillation.

Animals↗

PubMed2005

Computer construction and analysis of protein models of the mutant gammaD-crystallin gene.

BACKGROUND: Gammad-crystallin plays an important role in human cataract formation. Being highly stable, gammaD-crystallin proteins are composed of two domains. In this study we constructed and analyzed protein models of the mutant gammaD-crystallin gene, which caused a special fasciculiform congenital cataract affecting a large Chinese family. METHODS: gammaD-crystallin protein structure was predicted by Swiss-Model software using bovine gammaD-crystallin as a template and Prospect software using human betab2-crystallin as a template. The models were observed with a Swiss-Pdb viewer. RESULTS: The mutant gammaD-crystallin structure predicted by the Swiss-Model software showed that proline23 was an exposed surface residue and P23T change made a decreased hydrogen bond distance between threonine23 and asparagine49. The mutant gammaD-crystallin structure predicted by the Prospect software showed that the P23T change exerted a significant effect on the protein's tertiary structure and yielded hydrogen bonds with aspartic acid21, asparagine24, asparagine49 and serine74. CONCLUSION: The mutant gammaD-crystallin gene has a significant effect on the protein's tertiary structure, supporting that alteration of gamma-crystallin plays an important role in human cataract formation.

Animals↗

PubMed2005

[The clinical application and research on vas deferens laser coagulation sterilization].

OBJECTIVE: To study the effect of Ar(+) laser on human vas deferens and to compare the effects of using different radiation levels with varying thickness of tissue and varying levels of injury. METHODS: After initial tests on animals, four human scrotums were opened and treated directly with Ar(+) laser radiation. Then 58 human individual scrotums were treated with radiation by the method of trans-skin puncture. The rate of sperm reduction and elimination was tested. RESULTS: In 60 cases, the sperms were found to be eliminated completely after six months of radiation treatment. In 2 cases the sperms were found not to be eliminated completely due to the insufficient radiation. CONCLUSION: Ar(+) laser is one of the best forms of radiation for coagulation of vas deferens. It can be used to coagulate vas deferens without any complications or sequelae.

Adult↗

PubMed2005

[Long-term follow-up of visual functions after pediatric cataract extraction and intraocular lens implantation].

OBJECTIVE: To assess the visual acuity and binocular function of children after pediatric cataract extraction and intraocular lens implantation. METHODS: 47 children with 68 eyes (< 13 years old) were included in the study: 12 children with monolateral traumatic cataract, 14 children with monolateral congenital cataract and 21 children with bilateral congenital cataract. Cataract type, cataract extent, age at surgery and presence of strabismus and nystagmus and the best corrected distant visual acuity (BCDVA) before surgery were recorded and as well. In addition, the best corrected near visual acuity (BCNVA) and binocular function were followed up for an average of (41.3 +/- 12.3) months. Statistical analysis was used to define factors that correlated with achieving good visual acuity and binocular function. RESULTS: BCDVA and BCNVA were 0.5 or better in 34 eyes (50.0%) and a good binocular function was achieved in 18 children (38.3%). Age at surgery, extent of cataract, absence of strabismus and nystagmus were significant for good BCDVA. Age at surgery, absence of strabismus and nystagmus, good BCDVA were significant for good binocular function. CONCLUSIONS: Good visual acuity and binocular function can be achieved after pediatric cataract extraction and intraocular lens implantation. Multiple factors correlated with achieving good visual function such as timing of surgery, type and extent of cataract, absence of strabismus and nystagmus etal.

Adolescent↗

PubMed2005

[Research of restriction display technique in cDNA microarrays preparation for detecting of HCV].

The cDNA microarrays for HCV detection was prepared. With the restriction display technique (RD), restriction enzyme Sau3A I was chosen to digest the full-length HCV cDNAs. The products were classified and amplified by RD-PCR. We separated the differential genes through polyacrylamide gel electrophoresis and sliver staining. Single bands were isolated which were cut out from the polyacrylamide gel. The third-round PCR could be performed by using the single bands as PCR template. The RD-PCR fragments were purified and cloned into the pMD18-T vectors. The recombinant plasmids were extracted from positive clones and the target gene fragments were sequenced. The cDNA microarray was prepared by spotting PCR products to the surface of amido modified glass slides by the robotics. We validated the detection of microarray by the hybridization and the results of sequence analysis. A total of 24 different cDNA fragments ranging from 200 to 800 bp were isolated and sequenced, which were the specific gene fragments of HCV. These fragments could be further used as probes in the microarray preparations. From the results of hybridization and sequence date analysis, the specificity, sensitivity, accuracy, reproducibility and linearity in detecting HCV RNA were satisfactory. RD technique is of great value in obtaining a large number of size-comparable gene probes, which provide a swift protocol in generating probes for the preparation of microarrays, and the optimized microarray is sensitive and effective in clinical diagnosis of HCV.

DNA Probes↗

PubMed2005

[Reform and application of the vas deferens puncture tube needle via skin].

The article gives a detailed introduction of the process of marking flat tube needle for vas deferens puncture and a brief explanation of its application. This kind of tube needle can be easily made of readily available material, convenient to be cleaned and sterilized, with high success rate of puncturing and good effect. Other tube needles can be made by imitating it.

Equipment Design↗

PubMed2004

Expression and proteolytic activity of calpain in lens epithelial cells of oxidative cataract.

OBJECTIVE: To study the role of calpain in the mechanism of oxidative cataract through detecting the level of intracellular free Ca(2+), the expression and proteolytic activity of calpain in the lens epithelial cells (LECs) of H(2)O(2)-induced cataract. METHODS: Rat lenses were cultured in vitro and cataract was induced by H(2)O(2). The level of intracellular free Ca(2+) was measured by fluorescence determination with fura-2/AM. The expression of m-calpain protein in LECs was detected with immunohistochemical method. The proteolytic activity in LECs was measured using a fluorogenic synthetic substrate. RESULTS: There were significant differences of the level of intracellular free Ca(2+) (P=0.001, 0.000, 0.000), the expression of m-calpain (P=0.001, 0.000, 0.000) and the proteolytic activity of calpain (P=0.001, 0.000, 0.000) between H(2)O(2)-induced and control group at 6, 12 and 24 h, respectively. CONCLUSIONS: H(2)O(2) can increase intracellular free Ca(2+), then enhance the expression and proteolytic activity of calpain which may play a role in the mechanism of oxidative cataract of rat.

Animals↗

PubMed2004

GDNF augments survival and differentiation of TH-positive neurons in neural progenitor cells.

GDNF plays an important role in the survival and differentiation of primary dopaminergic neurons, but it requires multiple factors for its entire range of activities. This study investigated the effects of GDNF and its cofactors on the development of bFGF-responsive neural progenitor cells (NPCs), mesencephalic and cortical progenitor cells (MP and CP). Various factors were found to have significant inductive effects on the survival and maintenance of these cells in late developmental stages. MP had greater potential than CP to differentiate into dopaminergic neurons. Treatment of NPCs with GDNF and its cofactors enhanced MAP-2 and TH expression, particularly the latter. These findings suggest that NPCs, particularly MP, could develop into more specific neurons if the appropriate factors were applied during the final cell fate specification. They might thus become beneficial sources of donor cells in the treatment of neurological disorders.

Animals↗

PubMed2004

[Preparation of the microarray for detecting hepatitis D virus].

OBJECTIVE: To prepare the microarray for detection of hepatitis D virus (HDV). METHOD: Several pairs of specific PCR primers were designed according to the conserved region of HDV genome. The DNA microarray were prepared by blotting the PCR products onto the surface of glass slides with the use of robotics, and restriction display PCR (RD-PCR) was employed to label the samples. RESULT: Sequences analysis showed that the products of PCR amplification were the specific gene fragments of HDV. Hybridization signals on the gene chip demonstrated good specificity and sensitivity of the microarray for HDV detection. CONCLUSION: Microarray-based clinical HDV detection can be sensitive and effective.

Base Sequence↗

PubMed2004

[Study on ultrastructure changes and the genetic locus for a special phenotype cataract].

OBJECTIVE: To report the ultrastructure changes and map the genetic locus for a special phenotype autosomal dominant congenital cataract (ADCC) in a large Chinese family. METHODS: A large four-generation Chinese family affected by this special phenotype ADCC was analyzed. Clinical examinations, light and transmission electron microscopy analysis of the removed lens tissue were performed. Blood samples were taken for DNA extraction and two-point linkage analyses between the polymorphisms of microsatellite markers near the gamma-crystallin gene (CRYG) and the disease-associated locus was also determined. RESULTS: The lens fiber cells displayed abnormal inter- and intracellular alterations, including irregular refractivity, focal degeneration and irregular and enlarged intracellular spaces. Linkage analysis showed that there was linkage between the ADCC disease-associated locus and D2S2208, D2S2382 and D2S164. CONCLUSIONS: There were characteristic alterations to the lens fiber cells of this special phenotype ADCC and the CRYGD gene might be the disease-associated.

Cataract↗

PubMed2003

Rapid preparation of DNA microarray using PCR for hepatitis B and D virus detection.

OBJECTIVE: To prepare DNA microarray for detecting both hepatitis B and D virus as (HBV and HDV). METHODS: With the assistance of Oligo6.4 software, specific PCR primers targeting the conserved region of HBV and HDV were designed. The PCR products were purified and cloned into the pMD18-T vectors, followed by rapid identification. The recombinant plasmids were then extracted from positive clones and the target gene fragments underwent sequence analysis. RESULTS: The gene fragments of HBV and HDV were obtained by PCR, which were confirmed by sequence analysis to be specific gene fragments of HBV and HDV. CONCLUSION: Using PCR amplification products to prepare the DNA microarray is quick, simple and effective.

Hepatitis B virus↗

PubMed2003

[Preparation of gene chip probes for Bacillus anthracis protective antigen].

OBJECTIVE: To study the method for rapid preparation of the gene chip probes for Bacillus anthracis protective antigen (pag). METHODS: According to the sequences of pag published on PubMed, a pair of primers was designed to amplify the PA gene of Bacillus anthracis. Restriction enzyme digestion and AT clone were employed to rapidly screen out the recons of PA segments for the preparation of the gene chip probes. The DNA sequences of these segments were determined with 377 DNA Sequencer, and the resultant sequences analyzed with Bioinformatic software. RESULTS: With the designed primers, the pag 2,205 bp in length was amplified. After enzyme digestion and AT clone, 7 fragments of varied lengths were screened, which underwent analysis with the basic local alignment sequence tool (BLAST) and 377 DNA Sequencer. BLAST analysis showed that all the fragments cloned belonged to Bacillus anthracis. CONCLUSION: PCR in conjunction with restriction enzyme digestion and AT clone is rapid and simple to prepare the desired gene chip probes.

Antigens, Bacterial↗

PubMed2003

[Prevention of oxidative cataract by PD150606 - an inhibitor of calpains].

OBJECTIVE: To observe oxidative cataract inhibition of PD150606 by studying the opacity of the lens, the variation of protein and cells, and by further studying the role of calpains in the mechanism of oxidative cataract. METHODS: Rat lenses were cultured in vitro with H(2)O(2) and PD150606. The lenses were observed under the microscope. Simultaneously, photograph analysis was performed in order to detect the variation of opacity; the proportion of WSP was determined by the method of Lowry; the number of apoptotic lens epithelial cells (LEC) was measured by flow cytometry; the expression of Caspase 3 in LEC was determined by SAS-PAGE electrophoresis and immunoblotting. RESULTS: Opacity of lens was enhanced in 24 hours when cultured with H(2)O(2) and PD150606. There were significant differences of relative gray scale between H(2)O(2)-induced and control group at 6, 12 and 24 hours (P < 0.05), significant differences of the proportion of WSP between H(2)O(2)-induced and control group at 12 and 24 hours (P < 0.01), significant differences of the number of apoptotic LEC at 6, 12 and 24 hours (P < 0.01) and significant differences of expression of Caspase 3 at 6, 12 and 24 hours (P = 0.000, 0.005, 0.004). CONCLUSION: PD150606, an inhibitor of calpain, can inhibit H(2)O(2)-induced opacity of lens, proteolysis and apoptosis of LEC partially. The activated calpains can induce degradation of crystallins and apoptosis of LEC, which may play a role in the mechanism of oxidative cataract. Caspase 3-dependent pathway may contribute to apoptosis of LEC induced by calpains.

Acrylates↗

PubMed2003

Quick preparations of human parvovirus B19 microarray probes using PCR.

OBJECTIVE: To prepare DNA microarray probes for the detection of human parvovirus B19. Method Specific PCR primers were designed with the Primer Premier 5.0 to amplify the conserved regions of human parvovirus B19 genome. The PCR products were cloned into the pMD-18 T vector. METHOD: Sequences analysis showed the PCR products conformed to the sequences contained in the genome of human parvovirus B19. RESULT: Sequences analysis showed the PCR products conformed to the sequences contained in the genome of human parvovirus B19. CONCLUSION: PCR amplification of the conserved and specific human parvovirus B19 genes is simple and effective to prepare the desired probes.

DNA Probes↗

PubMed2003

[Expression and modulation of basic fibroblast growth factor in bovine lens epithelial cells].

OBJECTIVE: To evaluate the expression of basic fibroblast growth factor (bFGF) in bovine lens epithelial cells (BLEC), the effects of fetal bovine serum on the expression of bFGF and to explore the effect of breakdown of blood-aqueous barrier on the expression of bFGF after cataract surgery. METHODS: BLEC were isolated and cultured. Western blot and immunohistochemistry method were used to determine the expression of bFGF in these cells. The dose effects (0.2%, 1.0%, 10.0% fetal bovine serum) and time effects (4, 8, 12, 24 h) of 10.0% fetal bovine serum on the expression of bFGF in BLEC were estimated by Western blot analysis. RESULTS: Immunocytochemical study revealed that the cytoplasm of BLEC could be stained positively by the anti-bFGF antibodies. Western blot analysis revealed the presence of bFGF with a molecular weight of 18 000. The expression of bFGF was upregulated in a dose-dependent and time-dependent manner by fetal bovine serum. There was statistically significant difference among the control group and the fetal bovine serum treated group (P < 0.05). CONCLUSIONS: BLEC express relatively low molecular weight bFGF. Fetal bovine serum can upregulate the expression of bFGF in the BLEC. Breakdown of blood-aqueous barrier after cataract surgery can stimulate the expression of bFGF in lens epithelial cells through increasing the serum level in the aqueous humor.

Animals↗

PubMed2003

[Effect of N-acetyl-L-cysteine and catalase on apoptosis of lens epithelial cell and the activity of caspase-3].

OBJECTIVE: To investigate the effect of antioxidants N-acetyl-L-cysteine and catalase on H(2)O(2)-induced apoptosis of lens epithelial cells and the activity of caspase-3. METHODS: Rat lenses were incubated in MEM with 2 mmol/L H(2)O(2) (H(2)O(2) groups) or without H(2)O(2) (control groups), antioxidants 100 micromol/L N-acetyl-L-cysteine and 900 U/ml catalase were used to block the oxidative injury of lens epithelial cells respectively. Lens opacification and apoptosis of lens epithelial cells were detected using transmission electron microscope and AnnexinV-PI staining after 24 hours incubation. The activity of caspase-3 was analyzed by Western blot at the same time. RESULTS: The observations revealed that 2 mmol/L H(2)O(2) could apparently induce lens opacification and lens epithelial cell apoptosis in vitro, the apoptosis rate increased to (31.20 +/- 3.31)% after 24 hours incubation, which is also the time caspase-3 was activated. Treatment with N-acetyl-L-cysteine and catalase could inhibit lens opacification, apoptosis and caspase-3 activation induced by H(2)O(2). The apoptosis rate decreased to (20.90 +/- 3.16)% and (15.02 +/- 2.41)% respectively (P < 0.01). CONCLUSION: These data indicate that antioxidants N-acetyl-L-cysteine and catalase, possibly through regulation of the activity of caspase-3, can prevent lens opacification and apoptosis of lens epithelial cells.

Acetylcysteine↗