Biomedical subjects

Ying Zhang

Publications and source records attributed to Ying Zhang.

At least 181 records · Page 10Linked to original sources

PubMed2006

[Regulation of nitric oxide-cyclic guanosine monophosphate pathway on cochlear sensitivity].

OBJECTIVE: To investigate the effect of nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway on cochlear sensitivity. Methods Ten groups of guinea pigs were treated with the following solutions by whole cochlear perfusion for 2 hours: (1) Artificial perilymph; (2) L-arginine; 93) Ca(2+)-ATPase inhibitor; (4) Ca(2+)-ATPase inhibitor + L-arginine; (5) Ca(2+)-ATPase inhibitor + cGMP; (6) Ca 2+ ATPase inhibitor + L-arginine + Non-selective NOS inhibitor; (7) eNOS inhibitor; (8) eNOS inhibitor + Ca(2+)-ATPase inhibitor; (9) eNOS inhibitor + Ca(2+)-ATPase inhibitor + L-arginine; (10) eNOS inhibitor + Ca(2+)-ATPase inhibitor + L-arginine + nNOS inhibitor. The compound action potential (CAP) and cochlea microphonics (CM) were measured to assess the changes of cochlear sensitivity. After the perfusion, the cochleae were harvested and prepared for transmission electron microscopy. RESULTS: The average threshold shift of CAP after perfusion Ca(2+)-ATPase inhibitor was 28.5 dB, and it was improved in group 4 with 9 dB by L-arginine, similar with group 5. The threshold shift of CAP in group 8 was 42.5 dB, and it decreased in group 9 by L-arginine, on this foundation nNOS inhibitor was added, increased threshold shift of CAP was 6.5 dB, similar with group 8. The results indicated that L-arginine could rivalry the role of Ca(2+)-ATPase inhibitor through the path of NO-cGMP. Transmission electron microscopy showed that Ca(2+)-ATPase inhibitor + L-arginine combined administration resulted in less vacuolization in out hair cell than that treated with Ca(2+)-ATPase inhibitor only. CONCLUSIONS: The NO-cGMP pathway could regulate cochlear sensitivity; L-arginine may improve the function of Corti's organ via nNOS, and they indicate an important role of supporting cells in the modulation of cochlear function.

Action Potentials↗

PubMed2006

[Two novel mutations in palmitoyl-protein thioesterase gene in two Chinese babies with infantile neuronal ceroid lipofuscinosis].

OBJECTIVE: To search for possible novel mutations in palmitoyl-protein thioesterase 1 (PPT1) gene in two Chinese babies with infantile neuronal ceroid lipofuscinosis (INCL). METHODS: Two probands with INCL, confirmed clinically and pathologically, were used for mutation search in PPT1 gene. Onset of the disease occurred before the age of 1 year and they mainly showed progressive mental and motor retardation. The 9 coding exons and their flanking intron sequences of palmitoyl-protein thioesterase 1 (PPT1) gene were amplified by using PCR and sequenced. The parents of proband 1 were also examined. RESULTS: One splicing mutation and two missense mutations were identified in the two probands: the proband 1 carrying a compound heterozygous mutation of a IVS1 + 1G-->A mutation in intron 1 and a c550G-->A mutation in exon 6 leading to the amino acid substitution of E184K. Additionally, the parents of the proband 1 also harbored one of the mutations of the patient, respectively. The proband 2 carrying a homozygous mutation of c272A-->C in exon 3, which resulted in the amino acid substitutions of Q91P. CONCLUSIONS: The IVS1 + 1G-->A mutation and Q91P mutation are novel mutations, which lead to INCL. The genetic abnormalities of PPT1 in Chinese patients may not be completely the same as those in the patients of other regions of the world.

Age of Onset↗

PubMed2006

[Research development of chemistry and bioactive activity of plant peptides].

As the technologies of separation, purification and determination develop rapidly, more and more peptide compounds, which have special bioactive and medical value, have been separated from natural plants, such as oligopeptides and cyclopeptides. The chemical structures and function of these plant peptides have been researched profoundly. This paper mainly reviews the composition, structure, bioactive function and medicine value of representative plant peptides in recent years, and can give some references about research and application of plant bioactive peptides.

Animals↗

PubMed2006

Association between the polymorphism in the promoter region of dopamine D4 receptor gene and chronic tic disorder.

OBJECTIVE: To study a possible association between the three functional polymorphisms in the promoter region of dopamine D4 receptor (DRD4) gene and chronic tic disorder. METHODS: Genomic DNA was isolated from the venous blood leukocytes of 84 unrelated patients with chronic tic disorder (Study group) and 100 healthy unrelated individuals (Control group). Polymorphisms of DRD4, 1240L/S, 616C/G and 521C/T, were genotyped by the allele-specific primer (ASP) PCR. Genotype, allele and haplotype frequencies were analysed by SHEsis online. RESULTS: There were significant differences in both allele and genotype frequencies (chi(2) = 8.419, P < 0.01; chi(2) = 7.860, P < 0.05 respectively) of DRD4-616C/G between the Study and the Control groups. Haplotypic frequencies of LCT (1240L/S, 616C/G, 521C/T) in the Study group were noticeably higher than in the Control group (chi(2) = 6.371, P < 0.05). CONCLUSIONS: There is an association between the DRD4-616C/G polymorphism and chronic tic disorder. The individuals with haplotype LCT (1240L/S, 616C/G, 521C/T) are susceptible to this disorder.

Adolescent↗

PubMed2006

[Determination of metacycline in mixture sample by synchronous-derivative fluorimetry].

A new synchronous-derivative fluorimetric method for the determination of metacycline (MTC) in the presence of oxytetracycline (OTC) is proposed. The degradation products of MTC in 0.1 mol x L(-1) NaOH are strongly fluorescent. The addition of cetyltrimethylammonium bromide (CTMAB) enhances the fluorescence intensity 2-fold. The synchronous fluorescence spectra of MTC and OTC degradation products do not interfere with each other under the condition that deltalambda = 100 nm. MTC can be determined in the presence of OTC in the range of OTC+MTC ratio of 1+116-1+1. The recoveries of MTC in the mixture sample are in the range of 94%-102%.

Cetrimonium↗

PubMed2006

Rapid changes in liver lipid composition and pancreatic islet K+ handling and secretory behaviour provoked by the intravenous administration of a medium-chain triglyceride: fish oil emulsion to long-chain polyunsaturated omega3 fatty acid-depleted rats.

Second generation rats depleted in long-chain polyunsaturated omega3 fatty acids are currently used as an animal model for the insufficient dietary supply of such fatty acids often prevailing in Western populations. The present study deals mainly with the effects of a novel medium-chain triglyceride: fish oil emulsion (MCT:FO), as compared to a control medium-chain triglyceride:olive oil emulsion (MCT: OO), administered as an intravenous bolus to the omega3-depleted rats 60-120 min before sacrifice upon selected biochemical and biophysical variables. The major findings consisted of a severe decrease of the omega3 fatty acid content of liver lipids in non-injected omega3-depleted rats and its partial correction after injection of the MCT:FO emulsion. The omega3-depleted rats also displayed liver steatosis, increased incorporation of long-chain polyunsaturated omega6 fatty acids in liver phospholipids and increased activity of liver Delta9-desaturase. As judged from the effects of ouabain upon 86Rb net uptake by isolated pancreatic islets, the activity of Na+,K+-ATPase was virtually abolished in the omega3-depleted rats. The latter defect was corrected by prior intravenous injection of the MCT:FO emulsion, this coinciding with suppression of the excessive secretory response to a number of insulin secretagogues otherwise observed in the islets of omega3-depleted rats injected or not with the MCT:OO emulsion.

Animals↗

PubMed2006

Fatty acid content and pattern of epididymal and parametrial adipose tissue lipids in streptozotocin (type 1) and Goto-Kakizaki (type 2) diabetic rats.

Attention was recently drawn to differences in the fatty acid pattern of liver phospholipids and triglycerides in animal models of type 1 and type 2 diabetes. The present study extends this knowledge to epididymal or parametrial adipose tissue lipids. The fatty acid pattern of such lipids was established in four fed female normal rats, four overnight fasted female normal rats, six fed female rats rendered diabetic by an injection of streptozotocin 3 days before sacrifice (STZ rats), and four female and four male Goto-Kakizaki rats (GK rats) also examined in the fed or fasted state. In addition to the fasting-induced and diabetes-related changes in plasma D-glucose and insulin concentrations, differences in either the weight percentage of fatty acids or the paired ratio between distinct fatty acids were often encountered. For instance, in the GK rats, gender differences were observed in the weight percentage of C18:2omega6, as well as C18:2omega6/C18:3omega6, C18:3omega6/C20:4omega6, C20:5omega3/C22:5omega3 and C22:5omega3/C22:6omega3 ratios. When compared to normal rats, the activity of Delta9-desaturase was markedly increased in GK rats and, to a lesser extent, in STZ rats. Starvation also increased to some extent the activity of Delta9-desaturase. The relative content of C22:6omega3 was also higher in diabetic than in normal rats. Further differences between GK and STZ rats concerned the generation of C18:3omega6 from C18:2omega6, C20:4omega6 from C18:3omega6, and C20:5omega3 from C18:3omega3. Several differences found in the adipose tissue of GK versus STZ rats were reminiscent of those recently identified in the liver triglycerides of these two types of diabetic animals, suggesting a common regulatory mechanism, possibly linked to the higher insulinemia of GK rats versus STZ rats.

Adipose Tissue↗

PubMed2006

Infection of Epstein-Barr virus in colorectal cancer in Chinese.

BACKGROUND & OBJECTIVE: Except for the tight correlation to nasopharyngeal carcinoma, accumulating evidences show that Epstein-Barr virus (EBV) is correlated to other carcinomas. This study was to investigate the correlation of EBV to colorectal carcinoma in Chinese. METHODS: EBV DNA was detected by polymerase chain reaction (PCR) in 90 specimens of primary colorectal carcinoma and 25 specimens of corresponding adjacent non-cancerous tissue, with the primers covering 2 different regions of EBV genome, BamH I W fragment and latent membrane protein 1 (LMP1) exon 3. The expression of EBV nuclear antigen 1 (EBNA1) and LMP1 were determined by immunohistochemistry, and the expression of EBV-encoded RNAs (EBERs) was detected by in situ hybridization. RESULTS: EBV LMP1 exon 3 and W fragment were detected in 27.7% and 32.2% of the 90 colorectal carcinoma specimens, which were significantly higher than the positive rate of EBV gene in the 25 adjacent non-cancerous tissues (4.0%, P<0.001). Of the 29 W fragment-positive tumors, 23 (79.3%) were EBNA1-positive, 1 (3.4%) was EBERs-positive; most EBNA1-positive cells were tumor cells with positive signals gathered in the nuclei. No expression of EBNA1 and EBERs were detected in the 8 W fragment-negative tumors. No expression of LMP1 was detected in all tumor specimens. CONCLUSION: EBV infection might be associated with colorectal carcinoma in Chinese.

Asian People↗

PubMed2006

[An improved motion estimation of medical image series via wavelet transform].

The compression of medical image series is very important in telemedicine. The motion estimation plays a key role in the video sequence compression. In this paper, an improved square-diamond search (SDS) algorithm is proposed for the motion estimation of medical image series. The improved SDS algorithm reduces the number of the searched points. This improved SDS algorithm is used in wavelet transformation field to estimate the motion of medical image series. A simulation experiment for digital subtraction angiography (DSA) is made. The experiment results show that the algorithm accuracy is higher than that of other algorithms in the motion estimation of medical image series.

Algorithms↗

PubMed2006

[Long-term follow-up study of moderate chronic obstructive pulmonary disease in elderly patients].

OBJECTIVE: To investigate the prognosis of moderate chronic obstructive pulmonary disease (COPD) in the elderly patients, and to evaluate the factors for long term survival. METHODS: From May 1993, a prospective cohort study was carried out, in which 191 elderly patients with moderate COPD were recruited in Shougang communities, Shijingshan District, Beijing. The general health state, arterial blood gas, pulmonary function test, electrocardiograph, chest X-ray and 6-minute-walk test (6MWT) were recorded. The patients were followed for 12 years. Univariate analysis of survival rate was performed by Kaplan-Meier method. The significance test was done by Log-rank method, and the baseline factors were analyzed using the COX regression model multiplicity. RESULTS: During the 12 years of follow-up, 10 patients were lost because of migration. Twenty-six patients died of non-COPD diseases, while 52 died of COPD. The survival rate was 81.7% (156/191) in 5 years, and 56.9% (103/181) in 12 years. The result with COX multiplicity showed that the important factors for prognosis of the patients were body mass index [BMI, relative risk (RR) = 0.916, 95% confidence intervals (95% CI) = 0.841 - 0.996], forced expired volume in one second (FEV(1), RR = 0.999, 95% CI = 0.998 - 1.000), arterial partial pressure of oxygen (PaO(2), RR = 0.929, 95% CI = 0.892 - 0.967), 6MWT (RR = 0.997, 95% CI = 0.995 - 1.000) and P pulmonale of ECG (RR = 4.081, 95% CI = 1.567 - 10.624). CONCLUSION: The important factors for prognosis of moderate COPD in elderly patients included BMI, FEV(1), PaO(2), 6MWT and P pulmonale in ECG.

Aged↗

PubMed2006

[Change in serum basic fibroblast growth factor level and its relationship to pulmonary arterial pressure in patients with acute exacerbation of chronic cor pulmonale on plateau].

OBJECTIVE: To assess the role of serum basic fibroblast growth factor (bFGF) in the development of hypoxic pulmonary hypertension in the patients with chronic cor pulmonale on highland (HACCP). METHODS: The levels of bFGF in serum of 38 patients with HACCP in the acute exacerbation stage, 30 patients with chronic obstructive pulmonary disease (COPD) in the remission stage and 30 normal control subjects were measured by sandwich enzyme-linked immunoadsorbent assay (ELISA). The mean pulmonary arterial pressure (MPAP) was measured by echocardiography. The partial pressure of oxygen in artery blood (PaO(2)) was measured by blood gas analyzer. RESULTS: The level of serum bFGF [(87.54+/-12.15) ng/L] and MPAP [(45.86+/-5.63)mm Hg (1 mm Hg=0.133 kPa)] in the patients with HACCP were significantly higher than those in the patients with COPD [(55.72+/-9.08) ng/L, (22.95+/-2.56)mm Hg, respectively, both P<0.01], those of the patients with COPD were both significantly higher than those of the normal control subjects [(49.83+/-8.78)ng/L, (20.34+/-2.23)mm Hg, respectively, both P<0.05]. The PaO(2) [(38.79+/-4.56)mm Hg] in the patients with HACCP was significantly lower than those in patients with COPD and normal subjects [(58.22+/-6.18) mmHg and (66.57+/-5.48)mm Hg, respectively, all P<0.01]. The level of serum bFGF in the patients with HACCP and the patients with COPD was positively correlated with MPAP (cor pulmonale group r=0.788, P<0.01; COPD group r=0.674, P<0.01)],negatively correlated with PaO(2) (cor pulmonale group r=-0.735, P<0.01; COPD group r=-0.587, P<0.01)). CONCLUSION: The level of serum bFGF in patients with HACCP is significantly increased; it may play an important role in the process of sustained hypoxic pulmonary hypertension in patients with HACCP.

Aged↗

PubMed2006

[The analysis of plasma homocysteine among 1020 residents in community].

OBJECTIVE: To study the plasma homocysteine (Hcy) distributive characteristics in different sex and age groups of the community residents in Guangdong, and to analyze its associated factors as well as its effects on cerebral artery stenosis. METHODS: In this study, we presented data concerning 2500 residents who had undergone a systematic health checkup,including clinical and biologic examinations. Plasma was saved from 1020 residents who were asymptomatic but having TCD examination. Hcy concentration was measured by fluorescence ration biochemical assay kit. RESULTS: The average plasma Hcy levels of males (15.0 micromol/L+/-5.8 micromol/L) were significantly higher than those of females (12.4 micromol/L-I 3.9 micromol/L, P< 0.05). Hcy level increased parallel with age. The prevalence rate of hyperhomocysteinemia in males (47.2%) was higher than in females (23.2%). Hcy levels in MCA stenosis group (18.3 micromol/L+ 5.3 micromol/L) were significantly higher than that in control group (12.9 micromol/L+/- 4.6 micromol/L, P< 0.05). Based on logistic regression analysis, Hcy was only associated with sex and age, but not with blood lipids etc. CONCLUSION: Hcy levels were different in sex and age groups which emerged as independent predictors of hyperhomocysteinemia but had no association with blood lipids in the community residents, suggesting that hyperhomocysteinemia might worsen cerebral artery stenosis.

China↗

PubMed2006

[Characteristics of T cell receptors recognizing antiphospholipid syndrome associated antigens].

To understand the characteristics of T cell receptors recognizing antiphospholipid syndrome associated antigen, the characteristics of T cells were analyzed using T cell receptor beta variable region (TCRbetaV) gene spectrotyping in a case of antiphospholipid syndrome (APS). The results indicated that in the case of APS there were 2 dominant T cell clones. The TCRbetaVs sequences of the 2 T cell clones showed the TCRbetaVs belonged to 8 and 23 gene families respectively. The peptides of third complementarity-determining regions (CDR3) in the TCRbetaVs were CASSLLVAGGPRAYNEQFFGPG and CASSLAGFGQPQHFGDG. Comparing the motifs in CDR3 with another autoimmune disease, the motif YNEQFFGPG in TCRbetaV8 and motif QHFGDG in TCRbetaV23 were identical with that of idiopathic thrombocytopenic purpura and systemic lupus erythematosus reported before. In conclusion, some T cell clones proliferating in these autoimmune diseases may recognize the same antigens.

Adult↗

PubMed2005

Bi-directional regulation of emodin and quercetin on smooth muscle myosin of gizzard.

This study is to reveal the characteristics of bidirectional regulation of emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) and quercetin on gizzard smooth muscle myosin. Our results indicate that: (a) emodin demonstrates stimulatory effects, and quercetin produces inhibitory effects on myosin phosphorylation and Mg(2+)-ATPase activities of Ca(2+)/calmodulin-dependent phosphorylated myosin in a dose-dependent manner; (b) a combination of emodin and quercetin enhances phosphorylation and Mg(2+)-ATPase activities for partially phosphorylated myosin and inhibits those activities for fully phosphorylated myosin; (c) 1-(5-Chloronaphthalene-1-sulfonyl)-1H2-hexahydro-1,4-diazepine inhibits myosin phosphorylation in the presence of emodin and/or quercetin. A combination of emodin and quercetin indicates its potential for modulating gastric-intestinal smooth muscle.

Animals↗

PubMed2005

Hypomethylation-linked activation of PAX2 mediates tamoxifen-stimulated endometrial carcinogenesis.

Tamoxifen, a selective oestrogen receptor modulator, has been used in the treatment of all stages of hormone-responsive breast cancer. However, tamoxifen shows partial oestrogenic activity in the uterus and its use has been associated with an increased incidence of endometrial cancer. The molecular explanation for these observations is not known. Here we show that tamoxifen and oestrogen have distinct but overlapping target gene profiles. Among the overlapping target genes, we identify a paired-box gene, PAX2, that is crucially involved in cell proliferation and carcinogenesis in the endometrium. Our experiments show that PAX2 is activated by oestrogen and tamoxifen in endometrial carcinomas but not in normal endometrium, and that this activation is associated with cancer-linked hypomethylation of the PAX2 promoter.

Animals↗

PubMed2005

Spin polarization dependence of carrier effective mass in semiconductor structures: spintronic effective mass.

We introduce the concept of a spintronic effective mass for spin-polarized carriers in semiconductor structures, which arises from the strong spin-polarization dependence of the renormalized effective mass in an interacting spin-polarized electron system. The majority-spin many-body effective mass renormalization differs by more than a factor of 2 at r(s) = 5 between the unpolarized and the fully polarized two-dimensional system, whereas the polarization dependence (approximately 15%) is more modest in three dimensions around metallic densities (r(s) approximately 5). The spin-polarization dependence of the carrier effective mass is of significance in various spintronic applications.

Journal Article↗

PubMed2005

Aggregation behavior of heteroleptic tris(phthalocyaninato) dysprosium complexes with different alkoxy chains in monolayer or multilayer solid films.

Three heteroleptic tris(phathlocyaninato) dysprosium triple-decker complexes with different alkoxy groups at the peripheral positions of the medium phthalocyanine ligand (Pc)Dy[Pc(OCnH(2n+1))8]Dy(Pc) (n = 4, 8, 16) (I-III) {Pc = unsubstituted phthalocyaninate; Pc(OC4H9)8 = 2,3,9,10,16,17,23,24-octakis(butyloxy)phthalocyaninate; Pc(OC8H17)8 = 2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninate; Pc(OC16H33)8 = 2,3,9,10,16,17,23,24-octakis(hexadecyloxy)phthalocyaninate} have been synthesized, and their aggregate behaviors in monolayer and multilayer solid films have been comparatively studied. The pure compounds and their 1:4 mixtures with stearic acid (SA) have been found to form a stable monolayer at the air/water interface with a tilted edge-on orientation of (Pc)Dy[Pc(OCnH(2n+1))8]Dy(Pc) molecules. In the pure monolayers of the three triple-decker compounds, wirelike molecular aggregates were observed by high-resolution transmission electron microscopy (HRTEM). Adding SA has been found to prevent triple-decker compounds (Pc)Dy[Pc(OC4H9)8]Dy(Pc) (I) and (Pc)Dy[Pc(OC8H17)8]Dy(Pc) (II) from forming large aggregates, and small domains with a diameter of ca. 10 nm were observed in the mixed monolayers. HRTEM studies revealed that two crystalline phases with rectangular and hexagonal lattice structure are present in the small domains. However, both pi-A isotherms and HRTEM studies indicated that the mixed monolayer of compound (Pc)Dy[Pc(OC16H33)8]Dy(Pc) (III) with SA did not show a difference from the corresponding pure monolayer. The SA molecules were pressed into the cavity above the phthalocyanine ring formed by the eight long hexadecyloxy side chains of the medium macrocycle ligand in III. The multilayer LB films of all of these triple deckers fabricated by the vertical dipping method showed very good layered structure as revealed by the multiple-order diffraction peaks in low-angle X-ray diffraction (LAXRD) patterns.

Journal Article↗

PubMed2005

Development of a quantitative method for determination of acrylamide in infant powdered milk and baby foods in jars using isotope dilution liquid chromatography/electrospray ionization tandem mass spectrometry.

An improved method has been developed for the determination of acrylamide in infant powdered milk and baby foods in jars, a particular class of foodstuffs which represent an important source of nutrition for young infants and babies. This method uses isotope dilution liquid chromatography coupled to a tandem mass spectrometer with electrospray ionization and is significantly more sensitive than previous published methods with a limit of quantification estimated at 1 microg kg(-1). The new method offers effective sample preparation procedures including defatting with petroleum ether, extraction with aqueous solution of sodium chloride, further liquid-liquid extraction with ethyl acetate and clean-up by solid-phase extraction (SPE) with HLB 200 mg cartridges. The analytical method was well validated and good results were obtained with respect to repeatability (RSD < 5%) and recovery (86-97%) which fulfilled the requirements defined by European Union (EU) legislation. The acrylamide level in infant powdered milk and baby foods in jars were 3.01-9.06 microg kg(-1) and 6.80-124.93 microg kg(-1), respectively. Especially, this new method is successfully applied to the trace quantification of acrylamide in infant/baby foods, the content of which is less than 10 microg kg(-1).

Acrylamide↗