Biomedical subjects

Ji Zhang

Publications and source records attributed to Ji Zhang.

At least 73 records · Page 4Linked to original sources

PubMed2004

Requirement of protein phosphatase 5 in DNA-damage-induced ATM activation.

The checkpoint kinase ATM is centrally involved in the cellular response to DNA double-strand breaks. However, the mechanism of ATM activation during genotoxic stress is only partially understood. Here we report a direct regulatory linkage between the protein serine-threonine phosphatase 5 (PP5) and ATM. PP5 interacts with ATM in a DNA-damage-inducible manner. Reduced expression of PP5 attenuated DNA-damage-induced activation of ATM. Expression of a catalytically inactive PP5 mutant inhibited the phosphorylation of ATM substrates and the autophosphorylation of ATM on Ser 1981, and caused an S-phase checkpoint defect in DNA-damaged cells. Together our findings indicate that PP5 plays an essential role in the activation and checkpoint signaling functions of ATM in cells that have suffered DNA double-strand breaks.

Ataxia Telangiectasia Mutated Proteins↗

PubMed2004

[Homocysteine-induced apoptosis of endothelial cell and its antagonism by folic acid--the roles of caspase3, c-IAP1 and c-IAP2].

OBJECTIVE: The present study addresses the question how Hcy induces endothelial apoptosis and how folic acid antagonizes the proapoptotic effects of Hcy. METHODS: Human umbilical vein endothelial cells (HUVEC) were treated with Hcy, with or without folic acid, for 24 hours. Cell apoptosis was evaluated by Annexin V staining and flow cytometery, as well as agarose gel analysis for genomic DNA ladder. The mRNA and protein levels of caspase3, c-IAP1, and c-IAP2 were analyzed by RT-PCR and Western blot, respectively. RESULTS: Treatment with both low (0.3 mmol/L) and high (3.0 mmol/L) concentrations of Hcy induced HUVEC apoptosis, with higher apoptotic rate at the latter case. Hcy-induced HUVEC apoptosis was accompanied by an increased level of caspase3 expression and activation, together with decreased c-IAP2 level. Folic acid upregulated c-IAP2 expression while attenuating Hcy-induced apoptosis and caspase3 activation. CONCLUSION: Hcy may induce HUVEC apoptosis via a pathway involving caspase3, which can be partially antagonized by folic acid, possibly through upregulated c-IAP2 expression.

Apoptosis↗

PubMed2004

[Genetic polymorphisms of three STR loci on chromosome X and their forensic application in a Chinese Han population].

OBJECTIVE: To understand the allele structure and genetic polymorphism at three STR loci on chromosome X in Chinese Han population and make an evalution of their forensic application. METHODS: EDTA-blood samples were collected from the unrelated individuals in Chengdu, China. After being extracted with Chelex method, the DNA samples were amplified by PCR technique. The PCR products were analyzed by PAG electrophoresis and the approach of automated fluorescence detection. Hardy-Weinberg equilibrium of females was tested and every forensic interested value was calculated. RESULTS: The polymorphisms of all 3 STR loci were obtained from 100 unrelated females and 120 unrelated males from Chinese Han ethnic group. Chi-square tests on the genotype frequencies in females did not reveal deviations from Hardy-Weinberg equilibrium. CONCLUSION: The obtained data are beneficial to understanding the population genetics of the three STR loci in Chinese Han population. For forensic genetics, the obtained data can be used to calculate the probabilities dealing with the paternity test and the individual identification.

China↗

PubMed2004

[Increased atria expression of receptor activity-modifying proteins in heart failure patients].

OBJECTIVE: Receptor activity-modifying proteins (RAMPs) determine the ligand specificity of the calcitonin receptor-like receptor (CRLR); co-expression of RAMP1 and CRLR results in a calcitonin gene related peptide (CGRP) receptor, whereas the association of RAMP2 or RAMP3 with CRLR gives an adrenomedullin(ADM) receptor. As CGRP and ADM may play a beneficial role in heart failure, this study aimed at the question whether RAMPs mRNAs are changed in heart failure. METHODS: Semi-quantitative reverse transcription-PCR (RT-PCR) was used to detect and quantify the mRNAs of RAMP1 and RAMP3 in the atria of heart failing patients. RESULTS: It was found that the expressions of RAMP1, RAMP2 and RAMP3 mRNAs increased with the worsening of heart function, but the expressions of RAMP1 and RAMP2 mRNA decreased at level IV of heart failure. CONCLUSION: The above results demonstrated in the atria of heart failure patients an up-regulation of CGRP receptor by an increase of RAMP1 in association with CRLR and an up-regulation of ADM receptor by an increase of RAMP2 expression in association with CRLR, thus suggesting that CGRP and ADM receptors be playing a functional role in compensating the chronic heart failure in human.

Adult↗

PubMed2004

[Identification on Chinese materia medica liquoric root by X-ray diffraction Fourier fingerprint pattern method].

OBJECTIVE: To develop a new identification and analysis method of Chinese medicinal materia Liquoric Root. METHODS: Powder X-ray diffraction Fourier fingerprint pattern. RESULTS: Experiments and analysis were carried out on ten samples. The standard X-ray diffraction Fourier fingerprint pattern and characteristic diffraction peaks of Liquoric Root were obtained. CONCLUSION: This method can be used for identification of Chinese medicinal materia Liquoric Root.

Drugs, Chinese Herbal↗

PubMed2004

[Establishment of CPP-SOM integrated cDNA microarray technology].

OBJECTIVE: To get an insight into the molecular mechanisms of diseases development and targeted therapy at the transcriptome level and search for potential therapeutic targets. METHODS: The present researchers established a cDNA microarray platform and applied component plane presentation integrated self-organizing map (CPP-SOM) to the microarray data obtained from a differentiation model, all trans retinoic acid-induced differentiation in NB4 cells. RESULTS: The platform included 12630 unique clones, including 9436 known genes. By CPP-SOM, the researchers were able to not only well classify the regulated genes into functionally distinct categories but also depict transcriptional changes throughout the process of the development of diseases or drug treatment. CONCLUSION: The platform has proven to be steady and reliable, and the CPP-SOM could serve as an important and good tool for analysis of microarray data.

Cell Line, Tumor↗

PubMed2004

[Genetic polymorphism of 3 STR loci on chromosome X and its forensic application in Chinese population].

To investigate the genetic polymorphisms of three short tandem repeats loci of chromosome X in Chinese Han population in Chengdu area and its use in forensic science. Three X-chromosome linked short tandem repeat loci were analyzed by PCR followed by polyacrylamide gel electrophoresis. Hardy-Weinberg equilibrium was tested and forensic interested value was calculated . The power of exclution of DXS6804, DXS9896 and GATA144D04 is 0.5990, 0.6220, 0.4280, respectively. The result showed that all the three STR loci were polymorphic among 100 unrelated females and 120 unrelated males from Chinese Han population. Chi(2) tests demonstrated that genotype frequencies in females did not depart from Hardy-Weinberg equilibrium. Three X-chromosome linked short tandem repeat loci have high polymorphism, they can be applied to forensic medicine and population genetics.

Alleles↗

PubMed2003

Further utilization of mucohalic acids: palladium-free, regioselective etherification and amination of alpha,beta-dihalo gamma-methoxycarbonyloxy and gamma-acetoxy butenolides.

Palladium-free etherification and amination of mucohalic acid methyl carbonates 1e (3,4-dichloro-5-methoxycarbonyloxy-5H-furan-2-one) and 1f (3,4-dibromo-5-methoxycarbonyloxy-5H-furan-2-one) and mucochloric acid acetate 1h (3,4-dichloro-5-acetoxy-5H-furan-2-one) was achieved to afford gamma-functionalized alpha,beta-unsaturated gamma-butyrolactones in good to excellent yield. [reaction: see text]

Journal Article↗

PubMed2003

Phylogenetic changes in the expression of delta opioid receptors in spinal cord and dorsal root ganglia.

To assess the validity of rodent models for investigating the role of delta opioid receptors (DOR) in analgesia, the distribution of DOR binding and mRNA were compared between rodent and primate spinal cord and dorsal root ganglia (DRG), using receptor autoradiography and in situ hybridization, respectively. In mouse and rat spinal cord, [(125)I]-deltorphin-labeled DOR binding sites were detected throughout the gray matter. In contrast, in primate and particularly in human spinal cord, DOR binding was mainly present in laminae I-II, with little to no binding in deeper layers. Accordingly, in rodent spinal cord, DOR mRNA was expressed by a large number of neurons distributed throughout the ventral and dorsal horns, whereas in the primate, DOR expression was significantly lower, as evidenced by a moderate number of labeled cells throughout the gray matter in monkey and by only few labeled cells in human, mainly in Clarke's column and lamina IX. Major species differences in DOR expression were also observed in primary afferent cells bodies. In rat DRG, intense DOR mRNA hybridization was primarily observed over large ganglion cells immunopositive for neurofilament 200. In contrast, in monkey and human DRG, DOR mRNA was primarily detected over small and medium-sized ganglion cells. These results demonstrate major differences in the expression and distribution of DOR in the spinal cord and DRG between mammalian species. Specifically, they point to a progressive specialization of DOR toward the regulation of primary somatosensory, namely nociceptive, inputs during phylogeny and suggest that the effects of DOR agonists in rodents may not be entirely predictive of their action in humans.

Animals↗

PubMed2003

Estimate of standard deviation for a log-transformed variable using arithmetic means and standard deviations.

Analyses of study variables are frequently based on log transformations. To calculate the power for detecting the between-treatment difference in the log scale, we need an estimate of the standard deviation of the log-transformed variable. However, in many situations a literature search only provides the arithmetic means and the corresponding standard deviations. Without individual log-transformed data to directly calculate the sample standard deviation, we need alternative methods to estimate it. This paper presents methods for estimating and constructing confidence intervals for the standard deviation of a log-transformed variable given the mean and standard deviation of the untransformed variable. It also presents methods for estimating the standard deviation of change from baseline in the log scale given the means and standard deviations of the untransformed baseline value, on-treatment value and change from baseline. Simulations and examples are provided to assess the performance of these estimates.

Confidence Intervals↗

PubMed2003

Component plane presentation integrated self-organizing map for microarray data analysis.

We describe a powerful approach, component plane presentation integrated self-organizing map (SOM), for the analysis of microarray data. This approach allows the display of multi-dimensional SOM outputs of microarray data in multiple sample specific presentations, providing distinct advantages in visual inspection of biological significances of genes clustered in each map unit with respect to each RNA sample. Beneficial potentials of the approach are highlighted by processing microarray data from yeast cells as well as human breast malignancies.

Gene Expression Profiling↗

PubMed2003

First direct reductive amination of mucochloric acid: a simple and efficient method for preparing highly functionalized alpha,beta-unsaturated gamma-butyrolactams.

[reaction: see text] The first direct reductive amination of mucochloric acid (1) has been accomplished. Reaction of 1 with various alkyl, aryl, and benzylamines, followed by reduction in the same pot, provides an efficient method of obtaining N-benzyl-3,4-dichloro-1,5-dihydro-pyrrol-2-one and N-aryl (or alkyl)-3,4-dichloro-1,5-dihydro-pyrrol-2-ones.

Amination↗

PubMed2003

Induction of CB2 receptor expression in the rat spinal cord of neuropathic but not inflammatory chronic pain models.

Cannabinoids have been considered for some time as potent therapeutic agents in chronic pain management. Central and systemic administration of natural, synthetic and endogenous cannabinoids produce antinociceptive and antihyperalgesic effects in both acute and chronic animal pain models. Although much of the existing data suggest that the analgesic effects of cannabinoids are mediated via neuronal CB1 receptors, there is increasing evidence to support a role for peripheral CB2 receptors, which are expressed preferentially on immune cells. As yet, little is known about the central contribution of CB2 in neuropathic pain states. We report here that chronic pain models associated with peripheral nerve injury, but not peripheral inflammation, induce CB2 receptor expression in a highly restricted and specific manner within the lumbar spinal cord. Moreover, the appearance of CB2 expression coincides with the appearance of activated microglia.

Animals↗

PubMed2003

Is survival possible without arachidonate metabolites in the brain during systemic infection?

The central nervous system mediates a coordinated set of biological responses during systemic immune stimuli. These responses are essential for the organism to eliminate invading pathogens and restore health. Coincidentally, centrally produced prostaglandins play a determinant role in activating the neuronal circuits involved in the control of autonomic functions.

Arachidonic Acid↗

PubMed2003

Effect of body mass index on adenocarcinoma of gastric cardia.

AIM: Obesity has been proved as one of the main risk factors for gastric cardia adenocarcinoma (GCA) in the West. The objective of our research was to evaluate the relationship between obesity and the risk of GCA in people from North China. METHODS: A total of 300 patients who had been diagnosed as GCA and had accepted surgical operation at Beijing Cancer Hospital from 1995 to 2002 were enrolled. Data were collected from pathology materials and hospital records. Two hundred and fifty-eight healthy people who had accepted health examination at the same hospital during the same period were enrolled as controls. Height, weight and gender of them at the time of examination were also collected. Obesity was estimated by body mass index (BMI), computed as weight in kilograms per square surface area (Kg/m2). The degree of obesity was determined by using BMI< or =18.5, 24-27.9 and > or =28 (Kg/m2) as the cut-off points for underweight/normal, overweight and obesity, respectively. Associations with obesity were estimated by odds ratios (ORs) and 95 % confidence intervals (CIs). All ORs were adjusted for age and sex. RESULTS: The mean level of BMI was significantly lower in the patient group than that in the control group. The ORs for obesity in age groups 30-59 and 60-79 were 1.15 (95% CI=0.37-3.65) and 0.16 (95% CI=0.05-0.44) for males and 0.78 (95% CI=0.26-2.36) and 0.28 (95% CI=0.04-2.05) for females, respectively. The ORs for underweight were 2.42 (95% CI=0.56-10.53) and 4.68 (95% CI=1.13-19.40) for males in age subgroups 30-59 and 60-79 and 40.7 (95% CI=9.32-177.92) for females older than 60 yrs. BMI was significantly associated with GCA (P<0.01). Underweight people were at high risk for GCA. CONCLUSION: BMI is an independent risk factor for GCA. Underweight is positively associated with GCA.

Adenocarcinoma↗

PubMed2003

[Quantitative analysis of mixed hematopoietic chimersim based short tandem repeats loci after nonmyeloablative stem cell transplantation].

OBJECTIVE: To establish a method for quantitative analysis of mixed hematopoietic chimerism (MC) based on STR loci. METHODS: Using STR technique combined with PCR, we analyzed the peripheral blood samples collected from 3 nonmyeloablative stem cell transplantation recipients every 15 days after transplantation. RESULTS: The quantitative results coincided with the qualitative results of DNA electrophoresis and with the clinical outcomes. When the result of electrophoresis showed only donor's allele type we could still find out the recipient's specific allele. CONCLUSION: The quantitative analysis using STR-PCR can detect more subtle changes in the evidence of engraftment. It is a more efficient method for detect the hematopoietic chimerism post transplantation.

Chimera↗

PubMed2003

[Correlation between mutation of GyrA and ParC genes and quinolone resistance in Neisseria gonorrhoeae].

OBJECTIVES: To investigate the correlation between mutation of GyrA and ParC genes and quinolone resistance in Neisseria Gonorrhoeae. METHODS: The gene fragments of quinolone resistance-determining region (QRDR) in GyrA and ParC genes in 20 Neisseria gonorrhoeae strains clinically isolated in Wuxi, China, were sequenced, and the susceptibility of the 20 strains to quinolone was examined by agar diffusion method. RESULTS: The mutations at the Asp95 point in GyrA gene were found in 20 strains. Of the 19 stains examined, 16 had mutations at the 86, 87, 88, 91 points in ParC genes. CONCLUSIONS: The mutations of Asp95 in GyrA gene and Asp86, Ser87, Ser88, Glu91 in ParC gene contribute to quinolone resistance in Neisseria Gonorrhoeae.

Base Sequence↗

PubMed2002

Reinvestigation of mucohalic acids, versatile and useful building blocks for highly functionalized alpha,beta-unsaturated gamma-butyrolactones.

[reaction: see text] Mucohalic acids (mucochloric acid (1, 3,4-dichloro-5-hydroxy-5H-furan-2-one) and mucobromic acid (2, 3,4-dibromo-5-hydroxy-5H-furan-2-one)) are inexpensive, commercially available starting materials with multiple functional groups. These compounds have been modified by way of reduction followed by Suzuki cross-coupling reactions involving arylboronic acids to afford highly functionalized alpha,beta-unsaturated gamma-butyrolactones in excellent yield. The synthetic utility of these building blocks was effectively demonstrated through preparation of the antiinflammatory drug Vioxx.

4-Butyrolactone↗