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Biomedical subjects

J Y Zhang

Publications and source records attributed to J Y Zhang.

At least 19 recordsLinked to original sources
PubMed2003

Analysis of hepatitis B virus-immunoglobulin isotype complexes by a novel immuno-capture polymerase chain reaction method.

Hepatitis B virus (HBV) can be present in the circulating blood either as free virus or as a virion-immunoglobulin (Ig) complex. Presently, it remains unclear what specific role each Ig plays in the clearance of HBV. In this study, a novel method that combined immuno-capture and polymerase chain reaction (PCR) amplification was used for detecting and distinguishing different HBV-Ig complexes. Three isotypes of Ig (IgM, IgG and IgA) bound to HBV were detected in the four clinically defined stages of HBV infection in 108 patients. The results showed that all the three isotypes of Ig could bind to HBV, and the patterns of HBV-Ig complexes varied according to disease categories. Interestingly, the frequency of HBV DNA-Ig complexes in hepatitis B e antigen (HBeAg)-positive patients was significantly lower than that in HBeAg-negative patients. All the data suggest that the three isotypes of HBV DNA-Ig circulating immune complex (CIC) may have different biological meanings. In summary, HBV bound to an antibody is a common feature of hepatitis B, and immuno-capture PCR is a valuable method for the analysis of the composition of the immune complexes. The detection of HBV-Ig complexes may provide new and valuable insights into HBV pathogenesis.

Adolescent↗
PubMed2002

Analysis of HCV-immunoglobulin isotype complexes provide new insights into antibody response to HCV.

Hepatitis C virus (HCV) is known for its ability to establish persistent infection and cause chronic hepatitis in most infected individuals. The antibody response to HCV in HCV-circulating immune complexes (CIC) is unknown. In the present study, we have characterized distinct changes in patterns of HCV-immunoglobulin (Ig) constituents with disease category, viral mutation and clinical markers. The number of samples positive for single HCV-Ig, HCV-IgG and HCV-IgA, HCV-IgM and HCV-IgA, HCV-IgM and HCV-IgG, HCV-IgM, HCV-IgG and HCV-IgA in 47 samples tested were 8 (17%), 1 (2.1%), 9 (19.1%), 4 (8.5%) and 17 (36.2%), respectively. The occurrence of HCV-IgM and HCV-IgA in combination of two isotypes of HCV-Ig became predominant. These results show that defective IgG in HCV-CIC may contribute to long-term viremia. Further analysis indicated that the frequency of HCV RNA/IgA-CIC in the abnormal aspartic aminotransferase (AST) group was significantly higher than that of the normal AST group, and HCV RNA/IgA-CIC frequency in the abnormal alanine aminotransferase (ALT) group was slightly higher than that in the normal ALT group. IgA complexes may reflect the damage degree of liver function during the course of HCV infection. We also found that there were more mutations in supernatant than in other constituents from single-strand conformation polymorphism (SSCP) analysis. Our results suggest that Ig-complexed virions and free virions may have different biological consequences, with the latter being elusive to immunological elimination. The findings in this study may provide some new insights into antibody response to HCV.

Adolescent↗
PubMed2002

Analysis of complement-bound HCV complexes using a novel immuno-capture RT-PCR method.

Recently, more and more evidence has supported the hypothesis that liver cell injury was immune-mediated in patients with hepatitis C virus (HCV) infection, and that circulating immune complexes (CICs) might play a role in the pathogenesis of chronic hepatitis C (HC). In the present study, we have combined immuno-capture and reverse transcriptase-polymerase chain reaction (RT-PCR), and developed a quick method of high specificity for the detection of complement-bound HCV-CIC. We found that there were higher frequencies of HCV-C1q CIC than that of HCV-factor B, and there was a deviation of complement from immunoglobulin (Ig) in HCV-CIC. These findings suggest that immuno-capture RT-PCR (iRT-PCR) for the detection of HCV-bound CIC is a valuable method for the analysis of the composition of the immune complexes, and for the understanding of host immune response and immune pathogenesis in HCV-infected individuals.

Adolescent↗
PubMed2002

Cancer incidence and risk estimation among medical x-ray workers in China, 1950-1995.

Cancer incidence (1950-1995) among 27,011 medical diagnostic x-ray workers was compared by means of O/E system with that of 25,782 other medical specialists employed between 1950 and 1980 to provide evidence of human malignant tumors produced by protracted and fractionated exposure to ionizing radiation and to assess resultant cancer risk. Significant cancer risk was seen among diagnostic x-ray workers (RR = 1.2, 95% CI: 1.1-1.3). Significantly elevated risks were found for leukemia and cancers of skin, female breast, lung, liver, bladder, and esophagus; the RRs were 2.2, 4.1, 1.3, 1.2, 1.2, 1.8, and 2.7, respectively. The patterns of risk associated with years since beginning x-ray work and with age and calendar year of initial employment suggest that the excesses of leukemia, skin cancer, and female breast cancer-and possibly thyroid cancer-were related to occupational exposure to x rays. Because of a lack of individual dosimetry for Chinese medical x-ray workers (CMXW) before 1985, the dose was reconstructed by physical and biological retrospective dosimetry methods. The cancer risk of CMXW was estimated based on the reconstructed dose. The average cumulative dose for the earlier cohort (employed before 1970) was 551 mGy, and for the later cohort (employed from 1970 to 1980) it was 82 mGy. The RRs of leukemia and solid cancer were significantly high for the earlier cohort: 2.4 for leukemia, 1.2 for solid cancer. But no significant increase of RR was evident for the later cohort. The RR of leukemia was 1.7 and 1.1 for solid cancer. This means a significant cancer risk can be induced by long term fractionated exposure to ionizing radiation when the cumulative dose reaches a certain level.

Adult↗
PubMed2001

Rat mitochondrial ATP synthase ATP5G3: cloning and upregulation in pancreas after chronic ethanol feeding.

Individuals with chronic excessive alcohol ingestion are put at the risk of acute and chronic pancreatitis. Underlying molecular mechanisms are unknown. Differential gene expression in the pancreas was profiled using mRNA differential display by comparison between control and ethanol-consuming rats. Male Wistar rats were fed with diets containing 6.7% (vol/vol) ethanol for 4 wk. A cDNA tag that was overexpressed in the pancreas of rats fed ethanol was isolated. A 723-bp cDNA was cloned from a rat pancreatic cDNA library, which encodes a novel rat mitochondrial ATP synthase subunit 9, isoform 3 (ATP5G3), which is homologous to a human ATP5G3 gene. Real-time PCR demonstrated that all three nuclear gene isoforms (ATP5G1, ATP5G2, and ATP5G3) were consistently upregulated in the pancreas of alcohol-consuming rats, parallel with mitochondrial injury. The cellular response to mitochondrial damage and metabolic stress may reflect an adaptive process for mitochondrial repair in pancreatic acinar cells during chronic ethanol ingestion.

Amino Acid Sequence↗
PubMed2001

Ionization mechanism of oligonucleotides in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

The ionization of nucleosides in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was systematically investigated using adenine (A), thymine (T), guanine (G) and cytosine (C) with several common matrices. Experimental results of the protonation and deprotonation of the bases of A, T, G and C in the matrices 2,5-dihydroxybenzoic acid (2,5-DHB), alpha-cyano-4-hydroxycinnamic acid (alpha-CHCA) and 3-hydroxypicolinic acid (3-HPA) provide an insight into the ionization mechanism of oligonucleotides in MALDI. It was found that the low ion signal from DNA in poly-G in MALDI as reported in earlier work could be attributed to the fact that the base of G is difficult to ionize. Our results suggest that the ionization of DNA in MALDI is dominated by the protonation and deprotonation of bases and it is basically independent of the backbone of DNA. Both the protonation and deprotonation are strongly structure dependent. The protonation is dominated by pre-protonation before laser ablation, while the deprotonation is controlled by the thermal reaction.

Coumaric Acids↗
PubMed2001

Autoimmune responses to mRNA binding proteins p62 and Koc in diverse malignancies.

Two tumor-associated antigens, p62 and Koc, are insulin-like growth factor II (IGF-II) messenger RNA binding proteins. Autoantibodies to p62 have been detected in cancer sera but have not been reported for Koc. This study determined the extent and frequency of autoantibodies to p62 and Koc in diverse malignancies, the epitopes on the antigens, and the presence or absence of cross-reactive antibodies. Recombinant polypeptides were expressed from full-length and partial cDNA constructs and used as antigens in Western blotting, enzyme-linked immunoassay, and immunoprecipitation. After identifying the epitopes, cross-absorption with recombinant polypeptides was used to determine specificity. Sera from 777 patients with 10 different types of malignancy were analyzed. Autoantibodies to p62 were found in 11.6% and to Koc in 12.2% and cumulatively to both antigens in 20.5%, with significant difference from the control populations consisting of normal subjects and autoimmune disease patients (P < 0.01). The immunodominant epitopes were at the amino termini of both antigens and absorption studies showed that the majority of autoantibodies were not cross-reactive. Autoantibodies to p62 and Koc were present in approximately similar frequencies in a variety of malignancies and the immune responses appeared to be independent of each other. The immune responses might be related to overexpression or dysregulation of p62 and Koc in some tumors.

Antigens, Neoplasm↗
PubMed2001

Aberrant expression of fetal RNA-binding protein p62 in liver cancer and liver cirrhosis.

p62 is a RNA-binding protein that was isolated by immunoscreening a cDNA expression library with autoantibodies from patients with hepatocellular carcinoma (HCC). This autoantigen binds to mRNA encoding insulin-like growth factor II, which has been found to be overexpressed in HCC and is tumorigenic in transgenic animals. Immunohistochemical analysis of HCC liver showed that 33% (9 of 27) exhibited readily detectable staining of p62 protein in the cytoplasm of all malignant cells in cancer nodules, whereas it was undetectable in adjacent nonmalignant liver cells. In addition one of two patients with cholangiocarcinoma expressed p62 in malignant bile duct epithelial cells. p62 expression was also detected in scattered cells in cirrhotic nodules in contrast to uniform expression in all cells in HCC nodules. In HCC nodules, p62 mRNA was also detected by reverse transcriptase-polymerase chain reaction analysis. Nine normal adult livers did not contain detectable p62 mRNA or p62 protein whereas five fetal livers were all positive for mRNA and protein. The observations show that p62 is developmentally regulated, expressed in fetal, but not in adult liver, and aberrantly expressed in HCC and could be playing a role in abnormal cell proliferation in HCC and cirrhosis by modulating expression of growth factors such as insulin-like growth factor II.

Adult↗
PubMed2001

De-novo humoral immune responses to cancer-associated autoantigens during transition from chronic liver disease to hepatocellular carcinoma.

A feature of hepatocellular carcinoma (HCC) is that antecedent liver cirrhosis and chronic hepatitis are common precursor conditions and during transition to malignancy some patients develop autoantibodies which were not present during the preceding chronic liver disease phase. Serum samples from such patients can be used to immunoscreen cDNA expression libraries to identify genes encoding the new autoantigens. We demonstrate here the de novo appearance of antibodies to p62, a cytoplasmic protein which has been shown to bind to a developmentally regulated fetal species of insulin-like growth factor II (IGF-II) mRNA. Another antibody appearing during the transition period was against CENP-F, a cell cycle-related nuclear protein with maximum expression in the G2 and M phases of the cell cycle and previously shown to have a high association with malignancy. In three additional patients in whom serial serum samples were examined, new appearance of anti-p62 was detected in two patients and anti-CENP-F in one patient. This study demonstrates that transition to malignancy can be associated with autoantibody responses to certain cellular proteins which might have some role in tumorigenesis.

Antigens, Neoplasm↗
PubMed2001

Analysis of HCV-IG isotype complexes by a novel immuno-capture RT-PCR method.

HCV can be present in the circulating blood either as a free virus or as a virion-immunoglobulin (Ig) complex. All isotypes of Igs may form the virus complexes, but it remains unclear what specific role of each Ig plays in the clearance of HCV. In the present study, we have combined immuno-capture and RT-PCR, and developed a quick double-specificity method for detecting and distinguishing different HCV-Ig complexes. We compared our new method, the immuno-capture RT-PCR (iRT-PCR), with the conventional RT-PCR (cRT-PCR) for the sensitivity of detecting HCV in 35 clinically diagnosed patients with HCV infection. The results showed that 31 patients were detected to be positive by using iRT-PCR, whereas 16 patients were positive with the use of cRT-PCR. HCV-IgM, HCV-IgG, HCV-IgA could separately be detected by iRT-PCR and their positive rates were 66.7%, 51.0%, 62.7%, respectively. HCV bound to antibody was a common feature of hepatitis C (HC) and 86.3% of patients were positive at least by one of the HCV-Ig tests. The patterns of HCV RNA constituents varied according to disease categories. In summary, iRT-PCR is a valuable method for analysis of the composition of the immune complexes, which may provide new and valuable insights into HCV pathogenesis.

Adolescent↗
PubMed2001

Chronic ethanol consumption induces gene expression of pancreatic monitor peptide, but not SPINK1/PSTI-56, in rats.

The primary factors that predispose humans to the development of alcoholic pancreatitis are unknown. One of the earliest observations in humans in whom this disease develops is pancreatic hypersecretion caused by unknown mechanisms. Messenger RNA (mRNA) differential display was performed in a rat model to investigate the molecular mechanisms associated with ethanol-induced pancreatic hypersecretion. Male Wistar rats were pair-fed Lieber-DeCarli diets with or without ethanol for 7 days or 4 weeks. Total RNA was extracted from the pancreas and its neurohormonal control sites. Differentially expressed complementary DNA (cDNA) tags were isolated, cloned, and sequenced. One 248-bp cDNA was consistently and strongly induced in the pancreata of rats fed ethanol for 4 weeks. The sequence was highly homologous to both rat pancreatic monitor peptide (MP) and pancreatic secretory trypsin inhibitor (PSTI-56), also known as serine protease inhibitor, Kazal type 1 (SPINK1). Confirmatory reverse-transcription-polymerase chain reaction showed that PSTI-56 expression remained unchanged, whereas MP mRNA levels were elevated more than four times in the pancreata of ethanol-fed rats. These results indicate that long-term ethanol ingestion increases MP mRNA levels in the rat pancreas. Because MP stimulates cholecystokinin release and cholecystokinin is an important stimulant of pancreatic secretion, the enhanced MP gene expression may contribute to pancreatic hypersecretion.

Alcoholism↗
PubMed2001

Optimization of control parameters for petroleum waste composting.

Composting is being widely employed in the treatment of petroleum waste. The purpose of this study was to find the optimum control parameters for petroleum waste in-vessel composting. Various physical and chemical parameters were monitored to evaluate their influence on the microbial communities present in composting. The CO2 evolution and the number of microorganisms were measured as the activity of composting. The results demonstrated that the optimum temperature, pH and moisture content were 56.5-59.5 degrees C, 7.0-8.5 and 55%-60%, respectively. Under the optimum conditions, the removal efficiency of petroleum hydrocarbon reached 83.29% after 30 days composting.

Bacteria↗
PubMed2001

[Quantitative analysis of sparfloxacin injection by high performance liquid chromatography].

Analytical method of the quantitative determination of sparfloxacin injection by HPLC is described. The analytical conditions were as follows. A Waters Symmetry C18(5 microns, 150 mm x 3.9 mm i.d.) column was used as the analytical column. The detection wavelength was UV-298.8 nm. The column temperature was 30 degrees C. The mobile phase was 0.2% KH2PO4 buffer (pH 3.2)-CH3CN-CH3OH (80:15:5, volume ratio) and the flow-rate was 1.0 mL/min. The injection volume was 10 microL. The linear range (the peak area vs. the mass concentration of sparfloxacin) was from 39.94 mg/L to 199.68 mg/L, and the correlation coefficient was 0.9999. The average recovery of sparfloxacin was 100.1% (n = 5), and its RSD was 0.72%. The RSDs of continuous injections, within day injections per 2 hours and between day injections in three days were 0.19%, 0.14% and 0.13% respectively. The above analytical results show that this method has good precision and stability. It is a rapid, sensitive and accurate method for the analysis of sparfloxacin.

Antitubercular Agents↗
PubMed2001

[Human T cell and monocyte modulating activity of Rhizoma typhonii in vitro].

OBJECTIVE: To study the immunological modulating activity of Rhizoma typhonii (RT) on lymphocytes in vitro. METHODS: Effect of RT extract (RTE) on mice spleen cells and human lymphocytes proliferation was detected by sheep erythrocytes rosette forming test after lymphocytes had been isolated and purified. The activity of human killer cells and natrral killer (NK) cells was tested using 51 Cr free test. The production of cytokine of macrophages was examined using ELISA test and biological test and the phagocytic function of macrophage on tumor cell was determined using 3H incorporation assay. The chemical ingredients of RT were analyzed using chromatography and the molecular weight of their active principle was determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis technique (SDS-PAGE) method. RESULTS: RTE could markedly stimulate the mice spleen cells and human lymphocytes to proliferate in a dose-effect dependent manner; the effector cell of RTE is T cells. RTE enhanced human killer cell, the allo-antigen specific cytotoxic T lymphocytes (CTL) activity and the nonspecific activity of NK cells. Furthermore, RTE stimulated macrophage to produce tumor necrosis factor (TNF-alpha) and interleukin-1 (IL-1), and enhanced phagocytic activity of macrophage to tumor cells. The elution of RTE from chromatography showed that the active principle of RT was glycoproteins in nature and had an apparent molecular weight of 66 kDa. CONCLUSION: RTE has immunoenhancing activity to human T cell and macrophage, through stimulating the killer cell and phagocytosis of tumor cell and allo-antigen, which could be used clinically for modulating immune responses and for treating tumor and other diseases.

Aconitum↗
PubMed2001

[Immunomodulatory activity and anti-tumor activity of Oldenlandia diffusa in vitro].

OBJECTIVE: To study the effect of Oldenlandia diffusa (OD) on lymphocytes and tumor cells in vitro. METHODS: Effects of OD extract (ODE) on proliferation of spleen cells of mice and the phagocytosis of monocytes to tumor cells using 3H incorporation were analysed, and effect on specific activity of natural killer (NK) cells to human and mice's tumor cells was determined using free 51 Cr experiments, effects on B cells' antibody production and cytokine of monocyte production were investigated by ELISA and biological method, the chemical composition of OD was analyzed by chromatography, protease digestion and sugar decomposition (NaIO4) test. RESULTS: ODE could vigorously promote the proliferative activity of spleen cells in mice, specific lethal activity of human and mice's NK cell to tumor cells, B cells' antibody production, monocytes' cytokine production and its phagocytosis to remove the tumor cells. By means of chromatography, protease E digestion and NaIO4 treatment, the result of chemical composition analysis showed that the component of OD was 90 kDa glycoprotein. CONCLUSION: ODE has immuno-modulating activity and anti-tumor activity in vitro through stimulating the immune system to kill or engulf tumor cells, which could be used clinically for immune function modulation and to treat tumor and other diseases.

Adjuvants, Immunologic↗
PubMed2000

Assessing climate impacts.

Assessing climate impacts involves identifying sources and characteristics of climate variability, and mitigating potential negative impacts of that variability. Associated research focuses on climate driving mechanisms, biosphere-hydrosphere responses and mediation, and human responses. Examples of climate impacts come from 1998 flooding in the Yangtze River Basin and hurricanes in the Caribbean and Central America. Although we have limited understanding of the fundamental driving-response interactions associated with climate variability, increasingly powerful measurement and modeling techniques make assessing climate impacts a rapidly developing frontier of science.

Journal Article↗
PubMed2000

Origins of cholinergic inputs to the cell bodies of intestinofugal neurons in the guinea pig distal colon.

Integration of function between gut regions is mediated by means of hormones and long neuronal reflex pathways. Intestinofugal neurons, which participate in one of these pathways, have cell bodies within the myenteric plexus and project their axons from the gut with the mesenteric nerves. They form excitatory synapses on neurons in prevertebral ganglia that in turn innervate other gut regions. The aim of the present study was to characterise immunohistochemically the synaptic input to intestinofugal neurons. The cell bodies of intestinofugal neurons that project from the distal colon were labelled with Fast Blue that was injected into the inferior mesenteric ganglia. Varicosities surrounding Fast Blue-labelled neurons were analysed for immunoreactivity for the vesicular acetylcholine transporter, vasoactive intestinal peptide, and bombesin. Most intestinofugal neurons were surrounded by nerve terminals immunoreactive for the vesicular acetylcholine transporter; many of these terminals also contained vasoactive intestinal peptide and bombesin immunoreactivity. This combination of markers occurs in axons of descending interneurons. Extrinsic denervation had no effect on the distribution of cholinergic terminals around intestinofugal neurons. A decrease in the number of vesicular acetylcholine transporter and vasoactive intestinal peptide immunoreactive terminals occurred around nerve cells immediately anal, but not oral, to myotomy operations. Consistent with previous physiological studies, it is concluded that intestinofugal neurons receive cholinergic synaptic input from other myenteric neurons, including cholinergic descending interneurons. Thus, intestinofugal neurons are second, or higher, order neurons in reflex pathways, although physiological data indicate that they also respond directly to distension of the gut wall.

Afferent Pathways↗