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J Xia

Publications and source records attributed to J Xia.

At least 73 records · Page 4Linked to original sources
PubMed2000

Characterization of the basis of lipoprotein [a] lysine-binding heterogeneity.

Although elevated plasma concentrations of lipoprotein [a] (Lp[a]) are considered to be a risk factor for atherosclerosis, the mechanisms by which Lp[a] mediates its pathogenic effects have not been conclusively determined. The apolipoprotein [a] (apo[a]) component of Lp[a] confers unique structural properties to this lipoprotein, including the ability to bind to lysine residues in biological substrates. It has been shown, however, that only a fraction of plasma Lp[a] (Lp[a]-Lys(+)) binds to lysine-Sepharose in vitro. The nature of the non-lysine-binding Lp[a] fraction in plasma (Lp[a]-Lys(-)) is currently unknown. In the present study, the Lp[a]-Lys(+) fraction was determined in the plasma of six unrelated individuals; the Lp[a]-Lys(+) fraction in these plasma samples ranged from approximately 37 to approximately 48%. Interestingly, purification of the Lp[a] by density gradient ultracentrifugation followed by gel filtration and ion-exchange chromatography resulted in progressive increases in the Lp[a]-Lys(+) fraction. Addition of either purified low density lipoprotein (LDL) or fibronectin to the purified Lp[a] at a 1:1 molar ratio reduced the Lp[a]-Lys(+) fraction (maximal decrease of 34 and 20%, respectively) whereas addition of both fibronectin and LDL to the purified Lp[a] resulted in a further decrease (45% maximally) in this fraction. Similar results were obtained by using a recombinant expression system for apo[a]: addition of a 4-fold molar excess of either LDL or fibronectin to conditioned medium containing metabolically labeled recombinant apo[a] reduced the Lys(+) fraction by 49 and 23%, respectively. Taken together, our data suggest that the lysine-binding heterogeneity of plasma Lp[a] is not primarily an intrinsic property of the lipoprotein, but rather results in large part from its ability to noncovalently associate with abundant plasma components such as LDL and fibronectin. These interactions appear to mask the lysine-binding site in apo[a] kringle IV type 10, which mediates the interaction of Lp[a] with lysine-Sepharose. The contribution of these interactions to the function of Lp[a] in vivo remains to be investigated.

Apolipoproteins A↗
PubMed2000

Computer-assisted three-dimensional surgical planing and simulation. 3D soft tissue planning and prediction.

The purpose of this paper is to report a new technique for three-dimensional facial soft-tissue-change prediction after simulated orthognathic surgical planning. A scheme for soft tissue deformation, "Computer-assisted three-dimensional virtual reality soft tissue planning and prediction for orthognathic surgery (CASP)", is presented. The surgical planning was based on three-dimensional reconstructed CT visualization. Soft tissue changes were predicted by two newly devised algorithms: Surface Normal-based Model Deformation Algorithm and Ray Projection-based Model Deformation Algorithm. A three-dimensional color facial texture-mapping technique was also used for generating the color photo-realistic facial model. As a final result, a predicted and simulated patient's color facial model can be visualized from arbitrary viewing points.

Algorithms↗
PubMed2000

Three-dimensional virtual reality surgical planning and simulation workbench for orthognathic surgery.

A new integrated computer system, the 3-dimensional (3D) virtual reality surgical planning and simulation workbench for orthognathic surgery (VRSP), is presented. Five major functions are implemented in this system: post-processing and reconstruction of computed tomographic (CT) data, transformation of 3D unique coordinate system geometry, generation of 3D color facial soft tissue models, virtual surgical planning and simulation, and presurgical prediction of soft tissue changes. The basic mensuration functions, such as linear and spatial measurements, are also included. The surgical planning and simulation are based on 3D CT reconstructions, whereas soft tissue prediction is based on an individualized, texture-mapped, color facial soft tissue model. The surgeon "enters" the virtual operatory with virtual reality equipment, "holds" a virtual scalpel, and "operates" on a virtual patient to accomplish actual surgical planning, simulation of the surgical procedure, and prediction of soft tissue changes before surgery. As a final result, a quantitative osteotomy-simulated bone model and predicted color facial model with photorealistic quality can be visualized from any arbitrary viewing point in a personal computer system. This system can be installed in any hospital for daily use.

Cephalometry↗
PubMed2000

[Appraisal of postoperative transcatheter arterial chemoembolization (TACE) for prevention and treatment of hepatocellular carcinoma recurrence].

OBJECTIVE: To evaluate the effect of postoperative TACE for prevention and treatment of hepatocellular carcinoma (HCC) recurrence after radical resection. METHODS: From Jan. 1995 through March 1998, 109 HCC patients after radical resection were followed up with serum AFP, liver US and CT, chest X-ray film, hepatic artery angiography, etc. They were divided into 2 groups. Patients in group A (n = 68) with no residual tumor were given prophylactic TACE treatment, 1-2 times at the second and fifth month after operation. Patients in group B (n = 41) with residual tumor left were treated with regular TACE, once every 2 months. The 2 groups of patients were followed up for 6-45 months after operation. RESULTS: In group A, the real curative resection rate was 62.4%. Tumor recurrence was found in 10 of the 68 patients, with a total recurrence rate of 14.7% within 3 years after radical resection. The 1-, 2-, and 3-year cumulative recurrence rate was 7.4%, 13.2% and 14.7%, respectively. The 1-, 2-, and 3-year survival rate was 100%, 93.4% and 85.7%, respectively, while that in group B was 78.1%, 57.7% and 57.7%, respectively. The differences between the 2 groups of patients were statistically significant. The predictive pathological factors hampering completeness of tumor resection were: tumor size > 5 cm, more than 2 tumor nodules, the presence of satellite nodules, tumor with partial or without encapsulation and tumor thrombus in portal vein. Hepatic artery angiography with LP-CT and maintenance of high serum AFP level were the most sensitive methods for detecting residual tumor after operation. CONCLUSION: Post-operative TACE is very useful for prevention and treatment of HCC recurrence. It helps improve survival of surgically treated HCC patients.

Adolescent↗
PubMed2000

[Effect of yiqi yangyin huoxue recipe on endothelin and nitric oxide of type 2 diabetic patients with deficiency of both Qi-Yin and blood stasis syndrome].

OBJECTIVE: To study the effect of Yiqi Yangyin Huoxue recipe (YQYYHX) in treating type 2 diabetes mellitus (DM) patients with deficiency of both Qi-Yin (DQY) and blood stasis Syndrome. METHODS: Forty-one type 2 DM patients compared with those in the control group were observed. RESULTS: After treatment, the endothelin (ET) level of the treated group reduced significantly, and the total effective rate of blood sugar lowering were as follows: Fasting blood glucose (FBG) 87.80%, 2 hours postprandial plasma blood glucose (PBG) 90.24%. CONCLUSION: YQYYHX is effective in improving the patient's vascular endothelia cell functions by reducing the plasma ET level, clinical symptoms and blood sugar lowering.

Adult↗
PubMed2000

[Effect of Tripterygium polyglycoside on interleukin-6 in patients with Guillain-Barre syndrome].

OBJECTIVE: To study the action of interleukin-6(IL-6) in pathogenesis and effect of patients with Guillain-Barre syndrome (GBS). METHODS: Forty-three patients of GBS were selected according to Asbury's standard and divided into two groups on layer randomize principle, they were treated with adrenal corticosteroid and Tripterygium polyglycoside (TP) respectively. Serum and cerebrospinal fluid (CSF) content of IL-6 were measured by double antibody sandwich ELISA method. RESULTS: (1) The serum and CSF content of IL-6 in GBS group was higher than those in the normal control group significantly; (2) There was positive correlation between CSF IL-6 and clinical severity (P < 0.01) before treatment; (3) After treatment the clinical symptoms were improved in both groups, but the TP treated group showed better effect than the control group in improving symptoms and lowering serum IL-6 level (P < 0.05). CONCLUSION: CSF level of IL-6 could be taken as one of the criteria for severity evaluation of patient's condition. TP is superior in suppressing abnormal immune reaction to adrenal corticosteroid in GBS patients.

Adolescent↗
PubMed2000

[Cloning and expression analysis of human dystonia/deafness peptide like gene].

OBJECTIVE: To clone a new deafness associated gene. METHODS: Molecular database search, RACE and cDNA library screen were applied. RESULTS: A new gene, named dystonia/deafness peptide like (DDPL) (GeneBank Accession Number: DDPL2 AF165967) and mapped to 11q22.1-22.2, was cloned. DDPL had two different mRNA splicing types and accordingly encoded 83 and 51 amino acids. DDPL transcripts were detected in a range of adult and fetal tissues. A pseudogene of DDPL, named DDPLphi which was shown lying within Xq25-q26, showed 96.9% sequence identity with DDPL1 cDNA sequence across 382 bp. CONCLUSION: DDPL lies within the 5.2 Mb interval of 11q22.1-q22.2 between D11S939 and D11S1347, and has a high identity with the DFN-1/MTS associated gene-DDP.

Adult↗
PubMed2000

[Anatomical basis of autonomic nerve-preserving radical resection for rectal cancer].

OBJECTIVE: To clarify anatomical basis of autonomic nerve-preserving radical resection for rectal cancer. METHOD: Of 10 cadavers, 4 were male and 2 female. Four had hemisected pelvis in the mid-sagittal plane without damaging the retrorectal anatomy. All stages of each dissection were recorded photographically. RESULTS: Hypogastric nerves were identified. The superior hypogastric plexus is the direct extension of the aortic plexus below the aortic bifurcation. It lies immediately behind the peritoneum and descends over the anterior surface of the 5th lumbar vertebra in the retroperitoneal tissue. The superior hypogastric plexus ends by bifurcating into the right and left hypogastric nerves. The two hypogastric nerves diverge from each other at about the level of the sacral promontory and run down and forward along the walls of the pelvis in the lamina of the pelvic fascia closest to the peritoneum. Both of them are strong fibres with white-grey and reticular appearance and well located just below and close to the aortic bifurcation. And after bifurcation each of them also gives rise to several branches. But it is difficult to identify the pelvic splanchnic nerves in complete samples. In mid-sagitted samples they take origin from the second to fourth sacral ventral rami just after the sacral nerves have emerged from the pelvic sacral foramina. They always form plexus at the lateral ligament and are crossed by middle rectal artery. CONCLUSIONS: It is not very difficult to preserve the hypogastric nerves to spare functions in resection for rectal cancer to the anatomical knowledge of the pelvic autonomic nerves. When the pelvic splanchnic nerves are to be preserved, dissection must be cautious at the level of the lateral ligment on the side of nerve-preservation. The operation should be performed near the rectum as close as possible to achieve functional preservation.

Autonomic Pathways↗
PubMed2000

[The changes in serum antibody level after immunization with HFRS vaccine].

OBJECTIVES: To observe the changes in serum antibody level after mass immunization with vaccine against hemorrhagic fever with renal syndrome (HFRS) and to evaluate its efficacy and effectiveness in the prevalent areas. METHODS: Healthy people aged 16 to 60 years in the villages were recruited as study subjects, excluding those suffered from HFRS previously, going out for more than nine months and those with contraindications, and were randomly allocated into immunization and control groups with 10,460 and 16,159 persons, respectively. Specific IgG antibody was determined with indirect immunofluorescent assay (IFA) and neutralizing antibody (NA) was determined with micro CPE method. RESULTS: Two weeks after the full-course immunization, sero-conversion rate for IFA reached 100% in those sero-negative before immunization, with a 95% confidence interval of 96.3 - 100.0%, and that for NA 44.4%, with a 95% CI of 22.0% - 69.0%. Geometric mean titer (GMT) were 72.1 and 4.6 for IFA and NA, respectively. Booster immunization was provided for them one year later. Positivity of IFA and NA was 28.6%, 83.3%, 75.0%, 53.1%, 22.6% and 14.8%, 55.6%, 35.0%, 31.3%, 26.0%, before booster immunization, two weeks, one year, one and a half years, two years after booster immunization, respectively. CONCLUSION: HFRS vaccine had good immunogenicity, but its duration of serum antibody sustenance was relatively short.

Adolescent↗
PubMed2000

[Mutations in the connexin 26 gene in patients with nonsyndromic hearing impairment].

OBJECTIVE: To determine the prevalence and characteristics of deafness-causing mutations in Connexin 26(Cx26, GJB2) gene in Chinese with nonsyndromic hearing impairment(NSHI). METHODS: Study subjects are all Chinese including 16 infants with sporadic congenital deaf-mutism, 39 patients with autosomal recessive hereditary hearing loss, 30 patients with autosomal dominant hereditary hearing loss and 100 normal adults. The subjects were screened for base variations by single-strand conformational polymorphism (SSCP) analysis of the amplified products of polymerase chain reaction (PCR). Those who were found have abnormal conformational band were sequenced. RESULTS: Five kinds of polymorphism were found in 15 cases of controls and six kinds of polymorphism in 10 patients. No mutation was found in Cx26 gene in Chinese with autosomal recessive NSHI. Heterozygous deletion AT at position 299-300 of Cx26 cDNA, which results in premature chain termination, was found in a pedigree with autosomal dominant hereditary nonsyndromic hearing loss. CONCLUSION: The prevalence of deafness-causing mutations in Cx26 gene in Chinese with autosomal recessive NSHI maybe is lower than that of other ethnic groups. Heterozygous deletion AT at position 299-300 of Cx26 cDNA can lead to autosomal dominant hereditary hearing loss (DFNA3).

Asian People↗
PubMed1999

Duplication of 7p21.2-->pter due to maternal 7p;21q translocation: implications for critical segment assignment in the 7p duplication syndrome.

We describe a 1-year-old boy with mental and physical retardation, a large anterior fontanel, brachycephaly with flat occiput, short and stubby fingers, generalized hypotonia, ocular hypertelorism, low-nasal bridge, long philtrum, high-narrow palate, apparently low-set ears, and a small mandible. Cytogenetic analysis utilizing high resolution chromosome banding technique showed an unbalanced karyotype consisting of 46,XY,add(21)(q22.3) that originated from maternal balanced translocation between chromosomes 7 and 21. Fluorescence in situ hybridization (FISH) using micro-dissected library probe pool from chromosome 7 confirmed the additional material on 21q was derived from chromosome 7. Our results indicated that the patient had an unbalanced translocation, 46,XY, der(21)t(7;21)(p21.2;q22.3)mat, which resulted in duplication for distal 7p. Our patient is similar to reported cases with a 7p15-->pter or larger duplication of 7p, suggesting that the critical segment causing the characteristic phenotype of 7p duplication syndrome, including large anterior fontanel, exists at 7p21.2 or 7p21.2-->pter.

Abnormalities, Multiple↗
PubMed1999

Failure of measles virus to activate nuclear factor-kappa B in neuronal cells: implications on the immune response to viral infections in the central nervous system.

Neurons are postmitotic cells that foster virus persistence. These cells lack the HLA class I molecules required for clearance of infected cells. Previously, we showed that HLA class I is induced by measles virus (MV) on glial cells, which is primarily mediated by IFN-beta. In contrast, MV was unable to induce HLA class I or IFN-beta in neuronal cells. This failure was associated with lack of NF-kappa B binding to the positive regulatory domain II element of the IFN-beta promoter, which is essential for virus-induced IFN-beta gene activity. In this study, we demonstrate that the failure to activate NF-kappa B in neuronal cells is due to the inability of MV to induce phosphorylation and degradation of I kappa B, the inhibitor of NF-kappa B. In contrast, TNF-alpha induced degradation of I kappa B alpha in the neuronal cells, suggesting that failure to induce I kappa B alpha degradation is likely due to a defect in virus-mediated signaling rather than to a defect involving neuronal I kappa B alpha. Like MV, mumps virus and dsRNA failed to induce I kappa B alpha degradation in the neuronal cells, suggesting that this defect may be specific to viruses. Autophosphorylation of the dsRNA-dependent protein kinase, a kinase possibly involved in virus-mediated I kappa B alpha phosphorylation, was intact in both cell types. The failure of virus to induce I kappa B alpha phosphorylation and consequently to activate NF-kappa B in neuronal cells could explain the repression of IFN-beta and class I gene expression in virus-infected cells. These findings provide a potential mechanism for the ability of virus to persist in neurons and to escape immune surveillance.

DNA-Binding Proteins↗
PubMed1999

[Clinical application of chromosome haplotype analysis and mutation analysis to the diagnosis of Wilson's disease].

OBJECTIVE: To set up the method of gene diagnosis of Wilson's disease (WD) by chromosome haplotype analysis and mutation detection. METHODS: This study selected 3 (CA)n repeat genetic markers,D13S316, D13S133 and D13S314 to construct the chromosome haplotype within 8 Han WD families. PCR-SSCP was used to reconfirm the diagnosis of the siblings of the probands in the families where in the disease-causing mutation had been detected. RESULTS: One asymptomatic WD patient and 5 heterozygotes were detected. CONCLUSION: In the WD families, the analysis of chromosome haplotype helps to make the diagnosis of siblings of the probands;for the WD families in which the disease-causing mutation has been ascertained, mutation analysis can provide direct and definite evidence for diagnosis. The combination of these two methods can provide more evidences for diagnosis.

Genetic Markers↗
PubMed1999

Cloning and characterization of two cytoplasmic dynein intermediate chain genes in mouse and human.

Cytoplasmic dynein is a large multisubunit microtubule-based motor protein, which mediates movement of numerous intracellular organelles. We report here the identification of the human homologue of cytoplasmic dynein intermediate chain 1 gene (DNCI1) located on human chromosome 7q21.3-q22.1. The mouse orthologue (Dnci1) was identified along with another highly related gene, Dnci2, and their RNA in situ expression patterns were examined during mouse embryogenesis. Dnci1 was found to have a highly restricted expression domain in the developing forebrain as well as the peripheral nervous system (PNS), while Dnci2 displayed a broad expression profile throughout the entire central nervous system and most of the PNS. A dynamic expression profile was also found for Dnci2 in the developing mouse limb bud. The data presented here provide a framework for the further analysis of the functional role of Dnci1 and Dnci2 in mouse and DNCI1 in human.

Amino Acid Sequence↗
PubMed1999

Grape polyphenols protect neurodegenerative changes induced by chronic ethanol administration.

Increased oxidative stress in the brain due to chronic ethanol consumption is known to result in a number of neurodegenerative changes. This study was designed to test whether dietary supplementation of grape polyphenols (GP) can offer protection to the neurodegenerative changes resulting from chronic ethanol consumption. Sprague-Dawley rats were fed a Leiber-DeCarli liquid diet with ethanol or isocaloric amount of maltose, and with or without GP for 2 months. Chronic ethanol caused significant decreases in synaptosomal Na,K-ATPase (20.5%) and dopamine uptake (22.8%) activities compared with pair-fed controls. Although GP alone did not alter activities of these membrane-bound proteins, GP supplementation was able to completely protect the decrease in synaptic protein function elicited by chronic ethanol consumption.

Alcoholism↗
PubMed1999

Light scattering, CD, and ligand binding studies of ferrihemoglobin-polyelectrolyte complexes.

Quasi-elastic light scattering (QELS), electrophoretic light scattering (ELS), CD spectroscopy, and azide binding titrations were used to study the complexation at pH 6.8 between ferrihemoglobin and three polyelectrolytes that varied in charge density and sign. Both QELS and ELS show that the structure of the soluble complex formed between ferrihemoglobin and poly(diallyldimethylammonium chloride) [PDADMAC] varies with protein concentration. At fixed 1.0 mg/mL polyelectrolyte concentration, protein addition increases complex size and decreases complex mobility in a tightly correlated manner. At 1.0 mg/mL of greater protein concentration, a stable complex is formed between one polyelectrolyte chain and many protein molecules (i.e., an intrapolymer complex) with apparent diameter approximately 2.5 times that of the protein-free polyelectrolyte. Under conditions of excess polyelectrolyte, each of the three ferrihemoglobin-polyelectrolyte solutions exhibits a single diffusion mode in QELS, which indicates that all protein molecules are complexed. CD spectra suggest little or no structural disruption of ferrihemoglobin upon complexation. Azide binding to the ferrihemoglobin-poly(2-acrylamide-2-methylpropanesulfonate) [PAMPS] complex is substantially altered relative to the polyelectrolyte-free protein, but minimal change in induced by complexation with an AMPS-based copolymer of reduced linear charge density. The change in azide binding induced by PDADMAC is intermediate between that of PAMPS and its copolymer.

Animals↗
PubMed1999

A type 2 diabetes-associated polymorphic ARE motif affecting expression of PPP1R3 is involved in RNA-protein interactions.

We have previously described a polymorphism in the 3' untranslated region (UTR) of the PPP1R3 gene that encodes the muscle-specific glycogen-targeting regulatory PP1 subunit. This polymorphism alters the distance between two putative mRNA-destabilizing ATTTA (AUUUA) motifs and is distinguished by a 10-nucleotide (allele ARE1) vs a 2-nucleotide interval (allele ARE2). ARE2 is associated with insulin resistance as well as increased prevalence of type 2 diabetes in the Pima Indians, and correlates with reduced expression of this subunit in vivo, causing a 10-fold half-life reduction of reporter mRNA in NIH3T3 cells. Gel shift assays, Northwestern blotting, and RNA-protein UV crosslinking revealed three proteins (43, 80, and 139 kDa) binding to the polymorphic ARE region in these cells. The interactions are sequence specific, and can be suppressed by an unlabeled competitor in a dose-dependent manner. The less stable ARE2 allele shows at least 2-fold higher relative protein binding, indicating that the polymorphic ARE region has a mRNA-destabilizing role. We suggest that the increased protein binding to ARE2 contributes to a faster degradation of PPP1R3 mRNA carrying this allele, and the resulting lower concentration of the protein contributes to insulin resistance, thus increasing the risk for development of type 2 diabetes.

3' Untranslated Regions↗