Biomedical subjects

C Xue

Publications and source records attributed to C Xue.

At least 19 recordsLinked to original sources

PubMed2006

A family-based association study of megsin A23167G polymorphism with susceptibility and progression of IgA nephropathy in a Chinese population.

AIMS: To investigate the association of megsin A23167G polymorphism with susceptibility and progression of IgA nephropathy in Chinese population. METHODS: 435 IgA nephropathy patients and their family members were recruited for a family-based association study. Genotypes of megsin A23167G were determined by direct sequencing. The results were analyzed by transmission disequilibrium test (TDT) and haplotype relative risk (HRR). Clinical data and histological scores of renal lesions were compared between patients with different genotypes. According to disease stability, IgA nephropathy patients were divided into progressive group and stable group. The distribution of genotype frequencies were compared between the 2 groups. RESULTS: TDT revealed that megsin 23167G alleles were transmitted more frequently from heterozygous parents to patients than expected (classical TDT: chi2 = 5.435, p = 0.020, extended TDT: chi2 = 5.017, p = 0.025). HRR analyses showed significant differences between transmitted and nontransmitted allele frequencies (chi2 = 7.006, p = 0.008, HRR = 1.762). The scores of glomerular index and glomerular sclerosis index were higher in GG genotype patients than those in other genotypes (F = 4.570, p = 0.033, F = 4.324, p = 0.038, respectively). The distribution frequency of GG genotype in the progressive group was higher than that of the stable group (chi2 = 4.370, p = 0.037). No statistical difference was found in tubulo-interstitial index, vascular index and clinical characteristics between the 2 groups. CONCLUSION: The polymorphism of megsin A23167G is associated with susceptibility and progression of IgA nephropathy in Chinese population. GG genotype is associated with severe histological lesions and progression of the disease.

Adult↗

PubMed2004

Induced current density in the foetus of pregnant workers in high magnetic field environments.

There are moves to limit by legislation the amount of electric and magnetic fields that workers and the general public are exposed to. In work locations near wiring, cables & equipment carrying high electric currents, there are situations in which the proposed magnetic field limits could be exceeded. Since the limits for the general public are more conservative than those for workers and since the foetus or a pregnant worker should be afforded the status of a member of the general public, it is important to assess a worst-case scenario for the purposes of a general code of practice. Three different magnetic field exposures are modelled, which include the worst case - the body of a pregnant woman at a smallest distance of 30 cm to the conductor. All computations were done by using Multiple Multipole Program (MMP), which is based on the Generalized Multipole Technique (GMT) from ETH (Swiss Federal Institute of Technology), Zurich, Switzerland. In a worst-case scenario the proposed basic restrictions would be exceeded slightly in both maternal and foetal tissue. With appropriate pre-placement assessment, these over-exposures can be avoided.

Algorithms↗

PubMed2001

Conditional abatement of tissue fibrosis using nucleoside analogs to selectively corrupt DNA replication in transgenic fibroblasts.

Progressive tissue fibrosis can compromise epithelial function resulting in organ failure. Appreciating evidence suggests that fibroblasts provide fibrogenic collagens during such injury. We further tested this notion by attempting to reduce the physiologic consequences of organ fibrosis through the selective killing of fibroblasts at sites of injury. Here, we report the conditional reduction of tissue fibroblasts using the coding sequence for herpesvirus thymidine kinase (DeltaTK) put under the control of a cell-specific promoter from the gene encoding fibroblast-specific protein 1 (FSP1). Transgenic fibroblasts from mice carrying FSP1.DeltaTK minigenes expressed thymidine kinase concordantly with native FSP1 and, compared to transgenic epithelium, were selectively susceptible to the lethal effects of nucleoside analogs either in culture or during experimental renal fibrosis. The numbers of fibroblasts in fibrogenic kidney tissue were reduced on exposure to nucleoside analogs as was the degree of type I collagen deposition and the extent of fibrosis. Fibroblast reduction following the stress of DNA chain termination highlights the important contribution of cell division during fibrogenesis. Our findings convey a proof of principle regarding the importance of FSP1(+) fibroblasts in fibrosis as well as providing a new approach to treating the relentless scarification of tissue.

Animals↗

PubMed2001

Neuronal nitric oxide synthase: expression in rat parietal cells.

Nitric oxide synthases (NOS) are enzymes that catalyze the generation of nitric oxide (NO) from L-arginine and require nicotinamide adenine dinucleotide phosphate (NADPH) as a cofactor. At least three isoforms of NOS have been identified: neuronal NOS (nNOS or NOS I), inducible NOS (iNOS or NOS II), and endothelial NOS (eNOS or NOS II). Recent studies implicate NO in the regulation of gastric acid secretion. The aim of the present study was to localize the cellular distribution and characterize the isoform of NOS present in oxyntic mucosa. Oxyntic mucosal segments from rat stomach were stained by the NADPH-diaphorase reaction and with isoform-specific NOS antibodies. The expression of NOS in isolated, highly enriched (>98%) rat parietal cells was examined by immunohistochemistry, Western blot analysis, and RT-PCR. In oxyntic mucosa, histochemical staining revealed NADPH-diaphorase and nNOS immunoreactivity in cells in the midportion of the glands, which were identified as parietal cells in hematoxylin and eosin-stained step sections. In isolated parietal cells, decisive evidence for nNOS expression was obtained by specific immunohistochemistry, Western blotting, and RT-PCR. Cloning and sequence analysis of the PCR product confirmed it to be nNOS (100% identity). Expression of nNOS in parietal cells suggests that endogenous NO, acting as an intracellular signaling molecule, may participate in the regulation of gastric acid secretion.

Animals↗

PubMed2001

[The package and identifying of hNT-3 recombinated retroviral vector].

hNT-3 was inserted into retroviral vector pLXSN to get pLXSN-NT3, and it was transfected into packaging cell line PA317 to form G418 resistant cell clones. The G418 resistant clones were titered and checked for the existence of replication viral. Genome DNA isolated from the cell clone of highest titeration showed the function gene, hNT-3 cDNA, had integrated into the genome of host cells verified by PCR. And bioassay of the clone's cell culture supernant exhibited that it can induce neurite over-growth in the primary culatures of rat spinal cord dorsal root ganglions as compared with controls.

Animals↗

PubMed2000

Determination of proteins at nanogram levels based on their enhancement effects of Rayleigh light scattering on dibromomethylchlorophosphonazo.

A new Rayleigh light scattering (RLS) assay of protein was conducted in this paper. At the optimum pH conditions, and in the presence of Tween-20, the weak RLS of dibromomethylchlorophosphonazo (DBM-CPA) can be enhanced greatly by the addition of proteins. Based on this, the reactions of DBM-CPA and proteins were studied. A new quantitative determination method for proteins has been developed. The method is simple, practical and relatively free from interference from coexisting substances, as well as much more sensitive (the dynamic ranges of 0.065-40.05 microg ml(-1) and detection limit of 30 ng ml(-1) for bovine serum albumin (BSA)) than most of the existing assays. The determination results of human body serum samples are identical to those by the CBB method, with relative S.D. of six determination of 0.5-2.2%.

Blood Proteins↗

PubMed2000

Isolated hepatic cholinergic denervation impairs glucose and glycogen metabolism.

BACKGROUND: Hepatic innervation plays an essential role in insulin extraction and glucose production, but the specific role of hepatic cholinergic innervation remains unclear. We sought to establish a model of isolated hepatic cholinergic denervation (IHCD), and to assess whether glycogen storage or the control of net hepatic glucose production (HGP) was altered by IHCD. MATERIALS AND METHODS: Sprague-Dawley rats underwent either hepatic vagotomy or sham operation. Liver tissue was stained for vesicular acetylcholine transporter (VAChT) and (nonspecific neural) protein gene product 9. 5 (PGP) for verification of IHCD. Liver glycogen content was quantified in fed and fasted IHCD or sham-operated animals. HGP was determined after single-pass isolated liver perfusion, during which a 30-min 12 ng/ml glucagon infusion was begun after equilibration, and after 10 min, a 200 microU/ml insulin infusion was added. RESULTS: Uniform staining of PGP and absence of VAChT staining in hepatic vagotomized rats demonstrated the validity of our model. Glycogen content of sham-operated livers (n = 8) increased from 6.0 +/- 1.7 in the fasting state to 10.6 +/- 1.8 mg/g liver, after feeding (P < 0.05). IHCD livers (n = 8) showed no comparable increase (3.5 +/- 0.6 to 4.0 +/- 0.7 mg/g liver). Perfusion with glucagon alone resulted in less HGP in IHCD livers (n = 12) compared with sham-operated livers (n = 10) (integrated HGP 3.3 +/- 0.3 mg/g liver min(-1) vs 5.1 +/- 0.5 mg/g liver min(-1), P < 0.05). Insulin infusion revealed impaired responsiveness to insulin after IHCD; the ratio of HGP in the final 10 min of perfusion (glucagon and insulin) to HGP in the initial 10 min (glucagon alone) was 90.3 +/- 2.4% for IHCD livers versus 68.1 +/- 4.4% for sham-operated controls, respectively (P = 0.0002). CONCLUSIONS: Our study shows that IHCD results in significant impairment in liver glycogen storage and impaired hepatic sensitivity to glucagon and, possibly, to insulin. We conclude that hepatic cholinergic integrity is essential to normal hepatic glucose metabolism.

Animals↗

PubMed2000

[Study on antagonistic effects of selenium and zinc on the renal impairments induced by fluoride in rats].

Wistar rats were provided with distilled water containing NaF(100 mg/L), and were administered through gavage with Na2SeO3[0.1 mg/(kgBW.d)] and/or ZnSO4[14.8 mg/(kg BW.d)]. The results of biochemical, pathological and ultrastructural examinations showed that fluoride could cause serious renal impairments. The major damage induced by fluoride was epithelia of proximal renal tubules. The lipid peroxidation might be one of the mechanisms of fluoride toxicity. Na2SeO3 and ZnSO4 could antagonize the renal impairments induced by fluoride through their antioxidation. The cooperative effect of Na2SeO3 and ZnSO4 was more powerful than either Na2SeO3 or ZnSO4 alone.

Animals↗

PubMed2000

Microdetermination of proteins using m-carboxychlorophosphonazo as detection probe by enhanced resonance light scattering spectroscopy.

Proteins can be determined using a common spectrofluorometer to detect the intensity of resonance light scattering (RLS). Under acidic conditions, the reaction between m-carboxychlorophosphonazo (CPA-mK) and proteins enhances the weak light scattering of CPA-mK drastically. This enhanced intensity is proportional to the concentration of proteins. The linear ranges for human serum albumin are 0.5-35.0 microg/mL, with detection limits of 0.104 microg/mL. The method yields results comparable to those of the calorimetric method using Coomassie Brilliant Blue G-250 (CBB) with relative standard deviations of 0.72-2.10% (n = 10). There is almost no interference by amino acids and most of the metal ions.

Algorithms↗

PubMed2000

The high-sensitivity determination of protein concentrations by the enhancement of Rayleigh light scattering of Arsenazo-DBN.

A new Rayleigh light scattering (RLS) assay of protein is presented in this paper. At the optimum pH 4.10, the weak RLS of Arsenazo-DBN can be greatly enhanced by the addition of proteins due to the interaction between protein and Arsenazo-DBN. Based on this, the reactions of Arsenazo-DBN and proteins, including bovine serum albumin, human serum album, gamma-globulin, egg albumin, lysozyme and trypsin, were studied. A new quantitative determination method for proteins has been developed. The linear range for human serum albumin, for example, is 0.085-34.62 micrograms mL-1 with a detection limit of 44.8 ng mL-1. Besides high sensitivity, the method is characterized by good reproducibility, rapidity of reaction, good stability, and few interfering substances. The determination of the proteins in human serum and urine samples by this method give results very close to those obtained using Coomassie Brilliant Blue G-250 colorimetry, with relative standard deviations of 0.7-2.5%.

Arsenazo III↗

PubMed1999

Isolation and characterization of SYN1, a RAD21-like gene essential for meiosis in Arabidopsis.

The proper pairing, recombination, and segregation of chromosomes are central to meiosis and sexual reproduction. The syn1 mutation was previously identified as a synaptic mutant in a T-DNA-tagged population of plants. SYN1 has been isolated and found to exhibit similarity to Schizosaccharomyces pombe RAD21 and RAD21-like proteins, which are required for chromosome condensation and sister chromatid cohesion during mitosis. Plants homozygous for syn1 are male and female sterile and show defects in chromosome condensation and pairing beginning at leptonema of meiosis I. Fragmentation of the chromosomes was observed at metaphase I. Alternative promoters produced two SYN1 transcripts. One transcript was expressed at low levels in most tissues, whereas the other was expressed only in prebolting buds. DNA blot analyses suggest that Arabidopsis contains a small RAD21 gene family. Consistent with the DNA blot data, a second Arabidopsis RAD21-like gene has been identified. These results suggest that different RAD21-like proteins play essential roles in chromosome condensation and pairing during both meiosis and mitosis.

Amino Acid Sequence↗

PubMed1999

Developmental expression of protein phosphatase 2A in the kidney.

Although a number of growth and transcription factors are known to regulate renal growth and development, the signal transduction molecules necessary to mediate these developmental signals are relatively unknown. Therefore, the activity and mRNA and protein expression of the signal transduction molecule protein phosphatase 2A (PP2A) were examined during rat kidney development. Northern analysis of total kidney RNA or Western analysis of kidney protein homogenates from embryonic day 15 to 90-d-old adults demonstrated developmental regulation of the catalytic, major 55-kD B regulatory subunit and A structural subunit with the highest levels of expression in late embryonic and newborn kidneys. Similarly, okadaic acid-inhibitable phosphatase enzyme activity was highest in the embryonic and newborn kidney. To map cell-specific expression of PP2A in the developing kidney, in situ hybridization with a catalytic subunit digoxigenin-labeled cRNA was performed on embryonic day 20 and newborn kidneys. PP2A was found predominately in the nephrogenic cortex and particularly in the developing glomeruli and non-brush border tubules in the embryonic day 20 and newborn kidneys. Similarly, immunocytochemistry with a specific PP2A catalytic subunit polyclonal anti-peptide antibody demonstrated catalytic subunit protein particularly concentrated in the podocytes of glomeruli in the newborn kidney. In the adult kidney, PP2A protein was no longer detectable except in the nuclei of distal tubular cells. Therefore, the developmental regulation of PP2A activity and protein during kidney development and its mapping to the nephrogenic cortex, developing glomeruli, and tubules suggests a role for PP2A in the regulation of nephron growth and differentiation.

Aging↗

PubMed1999

[Detection of lipoarabinomannan-IgG in cerebrospinal fluid with enzyme-linked immunosorbent assay for diagnosis of tuberculous meningitis].

OBJECTIVE: To ascertain the value of lipoarabinomannan-IgG (LAM-IgG) determination in the diagnosis of tuberculous meningitis. METHODS: LAM-IgG in cerebrospinal fluid was detected with enzyme-linked immunosorbent assay. RESULTS: The positive rate of LAM-IgG in 73 patients with tuberculous meningitis was 51%, 36 control cases were all negative. The specificity was 100%. CONCLUSIONS: Detection of LAM-IgG in cerebrospinal fluid is a useful tool for diagnosis of tuberculous meningitis.

Antibodies, Bacterial↗

PubMed1999

[Studies on the feasibility of detecting circulating antibodies in saliva of Schistosoma japonicum infected rabbits].

AIM: To investigate the feasibility of detecting anti-Schistosoma japonicum antibodies in saliva. METHODS: Saliva and serum samples of 5 infected, 7 reinfected and 8 treated rabbits were collected at different times periods. The CAb in saliva and serum was detected by using ELISA. RESULTS: The sensitivity of ELISA was 94.7% for saliva and 100% for serum. The specificity of ELISA was 100% for both saliva and serum. CONCLUSION: Saliva can be used to detect circulating antibodies for the diagnosis of schistosomiasis japonica.

Animals↗

PubMed1999

[Establishment of a multiplex PCR system to detect plasmodium].

AIM: To establish a simple, rapid and practical multiplex PCR system to detect Plasmodium vivax(P. v) and Plasmodium falciparum(P. f). METHODS: A common upper primer S1 and two species-specific lower primers of P. v and P. f, S2, S3 were designed according to the sequences of the small subunit ribosomal DNA (SSUrDNA) fragments of the two Plasmodium species. Using these three oligonucleotide primers, the two-temperature-point multiplex PCR system was established and applied to detect P. v and P. f in the stock blood samples of clinically confirmed patients. RESULTS: DNA fragments of about 705 and 575 base pairs were successfully amplified by multiplex PCR from the genomic DNA of P. v and P. f, but no fragments were obtained from that of P. knowlesi, P. cynomolgi and blood of healthy persons. By means of restriction endonuclease digestion, the amplified fragments were confirmed to be the SSUrDNA fragments of P. v and P. f as expected. This method was successfully used in detecting parasitemia 2-10 parasite/microliter whole blood. Of 104 samples tested by this system, 81 were coincident with microscopic examination. The multiplex PCR system also found 17 samples of mixed infection, which were not detected microscopically. Another 2 samples detected as P. v by microscopic examination were verified to be P. f infection by the multiplex PCR. CONCLUSION: The ease of operation together with high sensitivity and specificity, particularly the sensitive detection for mixed infection in a single run of amplification suggests that the multiplex PCR system might be a useful tool for malaria diagnosis.

Animals↗

PubMed1999

[Determination of circulating antigen in urine of rabbits infected with Schistosoma japonicum].

AIM: To develop an immunoassay for the detection of circulating schistosome antigen (CSA) in host urine. METHODS: CSA extracted from the urine of the rabbits infected with Schistosoma japonicum was used for preparing and selecting specific monoclonal antibody. A one-step dot-ELISA using this specific McAb and a 2nd antibody was used for detection of circulating schistosome antigen in the urine of infected rabbits. RESULTS: No CSA was detected in urine from all of 22 rabbits before infection. The positive rate of CSA in infected rabbits was correlated with the intensity of infection and the time of infection. No CSA was detected in the urine rabbits of 3 weeks after infection with 25 cercariae while the positive rate of CSA in the urine from rabbits infected with 200 cercariae was 40% and 100% after 3 and 6 weeks, respectively. A combination of CSA detection in both urine and serum may increase the detectability. CONCLUSION: The specific McAb prepared by urine CSA of Schistosoma japonicum-infected rabbits can be used as a probe for detecting CSA in the urine of infected rabbits.

Animals↗

PubMed1999

[Establishment and application of dipstick sandwich colloidal dye immunoassay for circulating antigen detection in schistosomiasis patients].

AIM: To set up a simple immunoassay for the detection of circulating antigens in host serum. METHODS: A kind of colloidal pale purple dye (HFRL) used as a staining reagent for immunoassay was first selected from the dyes produced in China and an optimum condition for labelling the dye onto the combined IgM antibodies was explored. A dipstick sandwich colloidal dye immunoassay (DS-DIA) for the detection of circulating antigens in host sera was established. RESULTS: The minimal concentration of SEA detected was 5 ng/ml by DS-DIA. Serum circulating antigen detection in 14 cases of acute schistosomiasis japonica, 113 chronic cases and in 113 healthy controls revealed that the sensitivity was 100% in acute cases, 52.2% in chronic cases and the specificity was 92.9% for uninfected students. The sensitivity and specificity of DIA were similar to those of dot-ELISA. A certain degree of diagnostic complementarity up to 76.1% in sera from these patients was seen when DS-DIA and dot-ELISA were used in paralle. CONCLUSION: DS-DIA is a simple, economical and reliable method for detecting circulating antigens of Schistosoma japonicum, having a wide potential value especially for field use.

Adult↗

PubMed1999

[Preparation of monoclonal antibodies by intrasplenic immunization of mice with urine circulating antigen from patients infected with Schistosoma japonicum].

AIM: To explore an efficient method for preparing monoclonal antibodies against circulating antigen of S. japonicum in the urine of schistosomiasis patients. METHODS: The urine of schistosomasis patients were precipitated with 5% trichloroacetic acid, and then used to immunize the BALB/c mice by intrasplenic immunization to prepare McAb. RESULTS: Two monoclonal cell lines against the CAg in the urine of schistosomiasis patients have been established. The immunoglobulin subclass of the 2 McAbs (2E6 and 2B11) were identified as IgM. The titres of 2E6 and 2B11 were 2.56 x 10(5) and 6.4 x 10(4). On immunodiffusion, McAb 2E6 showed one precipitation line with IHU-CAg, however, both McAbs did not react with NHU-CAg. Using ascitic fluid of 2B11 and 2E6 as capture antibody separately, and HRP-H11 as labelled antibody to detect the urine of 12 acute schistosomasis patients, 2B11 2E6 gave 6 and 3 positive, respectively, whereas 8 normal urine were all negative. CONCLUSION: It is feasible to use CAg from schistosomasis patients' urine to prepare anti-CAg McAb by intrasplenic immunization in mice.

Animals↗