Biomedical subjects

Yong Jiang

Publications and source records attributed to Yong Jiang.

At least 91 records · Page 5Linked to original sources

PubMed2004

Effect of cold-ischemia time on nuclear factor-kappaB activation and inflammatory response in graft after orthotopic liver transplantation in rats.

AIM: To study the mechanism and effect of nuclear factor-kappaB (NF-kappaB) activation and inflammatory response on the extended cold-preserved graft injury after orthotopic liver transplantation (OLT). METHODS: OLT was performed in rats with varying time of cold ischemia grafts (6, 18 and 24 h in University Wisconsin solution at 4 degrees ). We determined the time of NF-kappaB activation and expression of tumor necrosis factor-alpha (TNF-alpha), cytokine-inducible neutrophil chemoattractant (CINC), and intercellular adhesion molecule-1 (ICAM-1) within 6 h after reperfusion. Serum alarming aminotransferase (ALT), neutrophil sequestration, circulating neutrophil CD11b and L- selectin expression were also evaluated. RESULTS: The accumulation of neutrophils in the graft was significantly increased in the 18 h and 24 h cold-ischemia groups within 0.5 h after reperfusion, compared with the 6 h group. But the strongly activated neutrophils was slightly increased at 2 h after reperfusion and remained at high levels 4 h after reperfusion, which was synchronized with the common situation of recipients after transplantation. Prolonged cold-preservation did not affect neutrophil accumulation and activation. NF-kappaB activation preceded the expression of TNF-alpha, CINC, and ICAM-1 in the liver, which was significantly increased with prolonged cold preservation. In prolonged cold preserved grafts, prominently elevated NF-kappaB activation occurred at 0.5 h and 1 h, compared with that at 2 h after reperfusion, which was consistent with greatly increased intrahepatic TNF-alpha response. CONCLUSION: NF-kappaB activation is correlated with the expression of TNF-alpha, CINC, and ICAM-1 in vivo in OLT rats. Extended cold preservation of grafts might up-regulate TNF-alpha, CINC, and ICAM-1 expression in the grafts, most probably through elevated NF-kappaB activation, and might contribute to neutrophil infiltration in the grafts after reperfusion. Elevated NF-kappaB activity is harmful to inflammatory response in the grafts, and inhibited NF-kappaB activity might protect against early graft injury after liver transplantation.

Animals↗

PubMed2004

The effect of C-terminal fragment of JNK2 on the stability of p53 and cell proliferation.

The basal activity of JNK is low in normal growing cells and inactivated JNK targets p53 for ubiquitination. To elucidate if the C-terminal part of JNK is responsible for its binding to p53, the low background tet-off inducible NIH3T3 cell line was selected by luciferase reporter gene and a double stable C-JNK Aa (203-424) cell line was established. After withdrawing tetracycline, the C-JNK fragment expression was induced and cell growth was dramatically inhibited 24 h later. However, the expression of p53 was found to be increased after the induction of C-JNK fragment, evaluated by transfecting p21waf-luciferase reporter genes. Our further studies showed that C-JNK fragment could form complex with p53 both in vivo and in vitro. Induction of C-JNK fragment in vivo can increase p53 stability by inhibiting p53 ubiquitination.

3T3 Cells↗

PubMed2004

Pharmacodynamic study of polyethylene glycol conjugated bovine hemoglobin (PEG-bHb) in rats.

The purpose of this study was to determine the pharmacodynamics of polyethylene glycol (PEG) conjugation on stroma-free bovine hemoglobin, hemorrhage shock, and exchange transfusion rat models were used. In both rat models, blood pressure increased in 6% PEG-bHb treated animals was significantly higher than dextran 70, even than whole blood (isovolume of hemorrhage) transfusion. Six percent PEG-BHb could ameliorate the micro-circulation of the experimental animals markedly, including reducing the blood viscosity and improving the blood flow. This effect of PEG-bHb was superior to autogenous blood which only recovered 50% blood flow, and there's no effect on blood flow when used isovolumic dextran 70. Tissue oxygenations of rats were evaluated by the oxygen dependent quenching of phosphorescence using an Oxyspot phosphorimeter, and the results showed that capability of oxygen-delivery of PEG-bHb was close to autogenous blood and superior to dextran 70. Based on these effects, the survival rates of animals treated with PEG-bHb were close to that of the whole blood transfusion. And data suggested that half of the hemorrhage transfusion is the reasonable therapeutic dosage. In conclusion, PEG-bHb is an effective blood substitute with powerful tissue oxygenation and blood volume expansion.

Animals↗

PubMed2004

Lung, spleen, and kidney are the major places for inducible nitric oxide synthase expression in endotoxic shock: role of p38 mitogen-activated protein kinase in signal transduction of inducible nitric oxide synthase expression.

Bacterial lipopolysaccharide (LPS) is known to induce endotoxic shock with inducible nitric oxide (NO) synthase (iNOS) expression and NO production. However, the major place for NO production in shock remains unclear. Although there is some literature about p38 mitogen-activated protein kinase (MAPK) in regulating LPS-induced iNOS expression, the results are contradictory. To interpret the precise cell mechanism and the role of p38 MAPK in the expression of iNOS during endotoxic shock, we carried out the following investigations. A severe endotoxic shock model was reproduced in mice 6 h after LPS injection. The plasma NO level was increased in a dose- and time-dependent manner after LPS stimulation and was suppressed by administration of SB203580 [4-(4-fluorophenyl)-2-4-methylsulfonylphenyl-5-(4-pyridyl) imidazole], a highly specific inhibitor of p38 MAPK. The iNOS expression was increased in many organs, including heart, liver, spleen, lung, gut, and kidney in endotoxic shock. Among them, the highest expression of iNOS mRNA and protein was in the lung, moderate expression was in the spleen and kidney, and the lowest expression was in the heart, gut, and liver. The level of expression in lung was 5.5 times that of iNOS mRNA and was 3.1 times that of iNOS protein than in heart, and 1.6 and 1.8 times that of iNOS mRNA and 1.7 and 1.4 times that of iNOS protein than in spleen and kidney, respectively. The p38 MAPK activity increased after LPS injection, and SB203580 markedly reduced LPS-induced expressions of iNOS protein and mRNA in the lung. The results indicates that lung, spleen, and kidney are the major places for iNOS expression in endotoxic shock and are important therapeutic target organs for attenuating NO production in shock treatment.

Animals↗

PubMed2004

[A study on relationship of purple tongue and its regional blood flow].

OBJECTIVE: To study the relationship of purple tongue and its regional blood flow. METHODS: Laser-Doppler flow meter was employed to test the volume and velocity of blood flow at different sites of purple tongue (56 cases) and normal tongue (54 cases), and the test results were analyzed. RESULTS: The volume of blood flow of purple tongue was significantly lower than that of the normal tongue (P<0.01), while the velocity was significantly higher (P<0.01). The volume and velocity of blood flow at different sites of the tongue were similar without significant difference. CONCLUSION: The volume of blood flow of purple tongue is decreased and the velocity increased. Purple tongue may be caused by dysfunction of the microcirculation of the tongue.

Adult↗

PubMed2004

[Structural characteristics and spectroscopic profiles of xanthones from Polygala].

Through studies of xanthones from Polygla tenuifolia, one of the main medicinal plants of Polygala, the structural characteristics and spectroscopic rules (including IR, UV, (1)H NMR and (13)C NMR data) of xanthones from Polygala were summarized, combined with the reference reports of this type of compounds from the other plants of Polygala. It is helpful to the structure elucidation of xanthones.

Magnetic Resonance Spectroscopy↗

PubMed2004

[Phase I clinical trial evaluation of capecitabine in concurrent combination of radiotherapy in nasopharyngeal carcinoma].

BACKGROUND & OBJECTIVE: Capecitabine is an oral fluoropyrimidine, which is converted to fluorouracil (5-FU) by exploiting the comparatively higher activity of thymidine phosphorylase (TP) in tumor tissue. This study was designed to measure the maximum tolerated dose (MTD) of capecitabine in the patients with nasopharyngeal carcinoma. METHODS: Medical records of 36 patients with nasopharyngeal carcinoma treated with radiation and capecitabine were reviewed. The median dose of capecitabine was 1 600 mgx(m(2)xd)(-1) [700-2 500 mgx(m(2)xd)(-1)] orally for 2 weeks followed 1 week of rest and then another cycle. All the patients received a total dose ranging from 66 Gy to 74 Gy over 6-7.4 weeks. RESULTS: In the 2 300 mgx(m(2)xd)(-1) group, Grade III toxicities observed were hang-foot syndrome (1 patient) and diarrhea (1 patient). CONCLUSION: Concurrent administration of capecitabine and radiation were tolerable in the patients with nasopharyngeal carcinoma. The maximum tolerated dose is 2 300 mgx(m(2)xd)(-1), The recommended phase II dose is 1 700 mgx(m(2)xd)(-1) daily administered by this intermittent schedule.

Adult↗

PubMed2004

[Construction and expression of the fusion vector of His-tagged human ARPC2 gene].

OBJECTIVE: To construct the expression vector of His-ARPC2 fusion protein and obtain its expression and purification in E. coli. METHODS: ARPC2 cDNA codon region was amplified by PCR from human liver cDNA library and cloned into pET-14b vector following the routine procedures. After identification by enzyme digestion, PCR and sequencing, the positive clones were transformed into BL21 (DE3) competent cells, and the expression of His-ARPC2 fusion protein was induced with IPTG and further purified by Ni-NTA affinity chromatography. RESULTS: The constructed His-ARPC2 fusion protein vector was highly efficiently expressed in E. coli. With Ni-NTA affinity chromatography, a purified His fusion protein with relative molecular mass of approximately 36 000 was obtained. CONCLUSION: The expression vector of His-ARPC2 fusion protein is constructed, expressed and purified under non-denaturing conditions, which may significantly facilitate future study of the physiological functions of ARPC2 and characterization of its interaction proteins.

Actin-Related Protein 2↗

PubMed2004

Pyrrolidine dithiocarbamate added to University of Wisconsin solution inhibits reperfusion injury after orthotopic liver transplantation in rats.

This study investigated the effects of pyrrolidine dithiocarbamate (PDTC), a novel NF-kappaB inhibitor, on the expression of multiple inflammatory mediators and on neutrophilic inflammation of the graft in rats following liver transplantation. Orthotopic liver transplantation (OLT) was performed after 24 hr of cold storage using University of Wisconsin (UW) solution that contained various concentrations of PDTC. We determined the time course of NF-kappaB activation and of the expression of multiple inflammatory signals: tumor necrosis factor-alpha (TNF-alpha), cytokine-inducible neutrophil chemoattractant (CINC), and intercellular adhesion molecule-1 (ICAM)-1. Serum alanine aminotransferase (ALT), intrahepatic myeloperoxidase (MPO/WBC ratio, a measure of neutrophil accumulation), and Mac-1 expression (CD11b/CD18, a measure of circulating neutrophil activity) were also evaluated. The results showed that PDTC decreased OLT-induced NF-kappaB activation in a dose-dependent manner (from 20 mmol/L to 60 mmol/L), diminished TNF-alpha, CINC, and ICAM-1 protein levels in the graft, and reduced the OLT-induced increase of serum TNF-alpha level. Pretreatment with PDTC significantly suppressed OLT-induced neutrophilic inflammation of the graft. The PDTC-exposed livers (PDTC, 40 mmol/L), in comparison with the control livers, had a significant reduction of MPO/WBC ratio (7.04+/-0.97 vs 14.07+/-1.31) and Mac-1 expression (181+/-11.3% vs 281+/-13.2%) at 6 hr after reperfusion. Furthermore, PDTC inhibited the increase of serum ALT levels after liver transplantation. In conclusion, PDTC inhibited NF-kappaB activation and the expression of the inflammatory mediators. These effects were associated with improved graft viability through inhibited intrahepatic neutrophilic inflammation. A therapeutic strategy directed at inhibition of NF-kappaB activation within the transplanted liver might be effective in reducing intrahepatic neutrophilic inflammation, and be beneficial to prolonged graft storage.

Adenosine↗

PubMed2004

[Dynamics of organic C in black soil of Northeast China, simulated by CENTURY model I. Accumulation of soil organic carbon under natural conditions].

By using CENTURY model, this paper simulated the dynamics of organic carbon and its fractions, including active, slow and passive pools, in black soils under natural condition at Nenjiang, Beian, Hailun and Harbin in Heilongjiang Province and at Gongzhuling in Jilin Province. The results showed that soil organic carbon had increased for a long time, and tended to reach the steady state. In the steady state, soil organic carbon reached 7914.72-11672.78 g x m(-2), which decreased from north to south in geperal. The active, slow and passive fractions were 3.36%-4.62%, 50.54%-55.47% and 36.47%-41.95% of soil organic carbon pool, respectively, which indicated that slow and passive fraction were the main body of soil organic carbon in native ecosystem. The simulated results were in agreement with some observed results, which can be used as the original data in the study on the dynamics of soil organic matter after cultivation.

Biodegradation, Environmental↗

PubMed2004

[Chemical mechanism of exotic weed invasion].

The ecological and economic impacts of exotic invasive weeds have been followed with interest. A successful invasion of exotic weeds depends not only on their bio-ecological traits, but also on some specific mechanisms of invasion. The clarification of the invasive mechanism of exotic weeds will be beneficial to predict and manage on them. In the process of establishment, reproduction and spreading, an exotic species has to become dominant in the interactions with native ones at new habitats, and then invades successfully. Among invasive mechanisms, the chemical interaction between exotic and native weeds should not be neglected. Previous studies showed that allelopathy plays an important role in exotic weed invasion. In fact, plants are able to defend or inhibit animals, plants and microbes from new habitats by using some specific chemicals. The chemical mechanism of exotic weed invasion might involve each aspect of plant chemical ecology. Therefore, chemical ecological characteristics of exotic weeds should be regarded as one of the most significant factors on predicting invasive species. The studies on chemical mechanism of exotic weed invasion will be one of the important aspects in future.

Biodiversity↗

PubMed2004

[Effect of astrocyte-conditioned medium on tert-butyl hydroperoxide-induced apoptosis of PC12 cells].

OBJECTIVE: To investigate the effect of astrocyte-conditioned medium (ACM) on PC12 cell apoptosis induced by reactive oxygen species tert-butyl hydroperoxide (tbOOH). METHODS: PC12 cells attacked by tbOOH were cultured with Sprague Dawley rat cerebral cortex ACM, and the cell apoptosis was observed by fluorescent microscopy and transmission electron microscopy. The cell apoptosis rate was evaluated by flow cytometry and malondialdehyde (MDA) concentration measured using thiobarbituric acid (TBA)-reacting substances (TRABS). RESULT: TbOOH induced PC12 cell apoptosis, and ACM significantly decreased the apoptosis rate and MDA concentration in tbOOH-treated cells. CONCLUSION: ACM may increase the anti-oxidation capacity of PC12 cells and inhibit cell apoptosis induced by tbOOH.

Animals↗

PubMed2004

Protective effect of tubuloside B on TNFalpha-induced apoptosis in neuronal cells.

AIM: To investigate the neuroprotective effect of tubuloside B, one of the phenylethanoids isolated from the stems of Cistanche salsa, on tumor necrosis factor-alpha (TNFalpha)-induced apoptosis in SH-SY5Y neuronal cells. METHODS: Cell viability was analyzed using MTT assay. Apoptotic cells were detected using Hoechst33342 staining, and confirmed by DNA fragmentation and flow cytometric analysis. The activity of caspase-3 was measured with special assay kit. The concentration of free intracellular calcium was determined with the probe Indo-1 by spectrometer. The level of intracellular reactive oxygen species and the potential of mitochondrial membrane were determined by laser scanning confocal microscopy (LSCM) combined with fluorescence probe H2DCFDA or JC-1 respectively. RESULTS: SH-SY5Y cells treated with TNFalpha 100 microg/L for 36 h showed typical morphological changes of apoptosis. DNA ladder could be observed by agarose gel electrophoresis. The highest percentage of apoptotic cells accumulated to 37.5 %. Following 36 h treatment with TNFalpha, accumulation of intracellular ROS and [Ca2+]i and decrease in mitochondrial membrane potential were observed, and caspase-3 activity increased by about five-fold compared with controls. However, pretreatment with tubuloside B (1, 10, or 100 mg/L) for 2 h attenuated the TNFalpha-mediated apoptosis. The antiapoptotic action of tubuloside B was partially dependent on an anti-oxidative stress effects, maintain of mitochondria function, decrease of concentration of free intracellular calcium and inhibition of caspase-3 activity. CONCLUSION: Tubuloside B has the neuroprotective capacity to antagonize TNFalpha-induced apoptosis in SH-SY5Y cells and may be useful in treating some neurodegenerative diseases.

Apoptosis↗

PubMed2004

[Effect of total Panax notoginseng saponins on the activity of human endothelial nitric oxide synthase gene promoter].

OBJECTIVE: To study the mechanism of total Panax notoginseng saponin (tPNS) in regulating the transcription activity of human endothelial nitric oxide synthase (heNOS) gene promoter. METHODS: With gene recombination technique, we subcloned the heNOS gene promoter sequence (from -1 to -1 600 bp) into the BglII/HindIII sites of the firefly luciferase reporter gene vector, pGL2-Basic (Promega), to yield the recombinant plasmid designated as peNOS-Luc. With lipofectamine- mediated co-transfection technique, peNOS-Luc, pGL2-Basic and pCMV-beta were cotransfected into NIH3T3 cells, which were treated with lipopolysaccharide (LPS), tPNS and transforming growth factor beta1 (TGFbeta1) respectively. The relative activities (Luc/beta-gal) were subsequently determined in the cell lysates to evaluate the effects of these 3 factors on the activity of heNOS gene promoter. RESULTS: Double restriction enzyme digestion and sequencing both confirmed that the recombinant plasmid, peNOS-Luc, was constructed correctly, which could be effectively expressed in NIH3T3 cells. Upon LPS stimulation, the luciferase activity was obviously decreased, contrary to the results of tPNS and TGFbeta1 treatment, and between the latter two agents, TGFbeta1 produced higher transcription activity. CONCLUSIONS: A firefly luciferase reporter gene vector containing heNOS gene promoter sequence has been constructed correctly. tPNS can up-regulate the activity of heNOS gene promoter in NIH3T3 cells.

Animals↗

PubMed2004

[Interobserver reproducibility in the pathologic diagnosis of borderline ductal proliferative breast diseases].

OBJECTIVE: The aim of this study involving general pathologists was to assess interobserver reproducibility in the pathologic diagnosis of borderline ductal proliferative breast diseases. METHODS: Ten general pathologists independently reviewed 43 specimens chosen to represent the spectrum of borderline ductal proliferative breast lesions. All slides were blindly reviewed without given standardized criteria, and were classified as either mild usual hyperplasia, moderate-severe usual hyperplasia, mild atypical hyperplasia, moderate-severe atypical hyperplasia, ductal carcinoma in situ, or ductal carcinoma in situ with invasion. According to the years of training, these 10 general pathologists were divided into the experienced group and the less trained group. Interobserver agreement was statistically analyzed using Kappa statistic. Then, by comparing all the diagnoses of individual pathologist with the consensus opinion confirmed by two breast pathologists in terms of Page standard, we acquired the diagnostic accuracy and ascertained the undue diagnosis. RESULTS: The ten general pathologists' interobserver reproducibility in the diagnosis of borderline ductal proliferative breast diseases was rather low, especially that in their diagnosis of atypical hyperplasia. The reproducibility and accuracy were slightly higher in the experienced pathologists than in the less trained pathologists. Some pathologists made over-diagnosis or under-diagnosis of the lesions to different degrees. However, when the categories of diagnostic terms were simplified, the interobserver reproducibility increased. CONCLUSION: The use of standardized criteria is an important approach to increasing the diagnostic reproducibility and accuracy.

Adult↗

PubMed2004

[Influence of temperature and light on the growth and development of Tenodera angustipennis and related preying functional responses].

Tenodera angustipennis was raised under laboratory conditions to study the influence of temperature and light on the growth and development of its nymphs. The functional responses of T. angustipennis to Plutella xylostella (L.) larvae and adults and to Lipaphis erysimi (Kaltenbach) were also studied. The results showed that temperature remarkably affected the growth and development of T. angustipennis, but light did not. The Holling models could well describe the functional responses of T. angustipennis to P. xylostella and L. erysimi.

Animals↗

PubMed2004

[Effects of urease/nitrification inhibitors on soil available N and microbial biomass N and on N uptake of wheat].

With an aquic brown earth as test soil, this paper studied the effects of urease inhibitor (NBPT), nitrification inhibitor (DCD) and their combinations on the dynamics of soil available N and microbial biomass N. The results showed that the treatments of inhibitors, especially the combined application of NBPT and DCD, could increase soil NH4+-N by 2%-53%, inhibit NH4+ oxidation, decrease soil NO3(-)-N concentration, increase soil total available N by 34%-44%, and increase wheat N uptake by 0.26%-6.79%. The best treatment was urease inhibitor combined with nitrification inhibitor. The application of inhibitors increased soil microbial biomass N immobilization at the early growth stage of wheat, and promoted soil N mineralization at filling stage.

Ammonia↗

PubMed2004

[Effects of water managements on soil nematode communities in a paddy field].

This paper studied the effect of water managements on the abundance, trophic groups and community composition of soil nematodes in a paddy field in the Lower Reaches of Liaohe Plain at the depths of 0-10 cm, 10-20 cm and 20-30 cm during rice (Oryza sativa L.) growth season. The total number of nematodes at 0-10 cm soil depth was lower in percolation-controlling treatments than in control during pre-tillage and yellow ripeness stage. No significant difference was found in the total number of nematodes at 10-20 cm soil depth during the study period, but significant difference was observed in 20-30 cm soil depth during pre-tillage and yellow ripeness stage. Sixteen families and 22 genera were observed, and Plectus, Tylenchus and Monhystera were the dominant genera. Plectus and Tylenchus were sensitive to different water managements. Significant difference was found in the number of bacterivores at 0-10 cm soil depth during pre-tillage and yellow ripeness stage in percolation-controlling treatments, which exhibited a similar trend with the total number of nematodes. Bacterivores and plant-parasites were the most abundant trophic groups in all plots and at all soil depths during the study period, averaging 60.8% and 33.8% of the nematode communities, respectively, and omnivores-predators were the least abundant groups.

Animals↗