Search PubMed⌕ Search

Biomedical subjects

Jie Chen

Publications and source records attributed to Jie Chen.

At least 73 records · Page 4Linked to original sources
PubMed2006

Angiotensin receptor blockade decreases fibrosis and fibroblast expression in a rat model of unilateral ureteral obstruction.

PURPOSE: Unilateral ureteral obstruction is characterized by histopathological changes including interstitial fibrosis, fibroblast specific protein expression, tubular atrophy and apoptosis, and macrophage infiltration. Angiotensin II has been implicated in some of these changes. We examined the effect of angiotensin blockade on markers of renal injury, including fibroblast specific protein expression, fibrosis, apoptosis and macrophage infiltration. We used losartan, an angiotensin II antagonist, in a unilateral ureteral obstruction model and studied animals 3 weeks after unilateral ureteral obstruction, a time at which renal damage is well established. MATERIALS AND METHODS: Rats underwent unilateral ureteral obstruction and were given either drinking water or losartan for 21 days. Kidneys were harvested and examined for fibrosis (trichrome and the Sircol assay for collagen), apoptosis (TUNEL), and fibroblast specific protein expression and macrophage infiltration (immunohistochemistry). RESULTS: Unilateral ureteral obstruction was found to induce fibrosis, apoptosis, fibroblast expression and macrophage in the obstructed kidney. Losartan significantly decreased apoptosis and macrophage infiltration in the obstructed kidney. It also decreased fibrosis, as measured by either trichrome staining assessed by a pathologist, the Sircol assay for collagen or fibroblast specific protein expression. However, approximately 50% of the changes were not affected by the current treatment, suggesting that other factors contribute to renal damage in unilateral ureteral obstruction. CONCLUSIONS: We observed the direct contribution of angiotensin II to both apoptotic and cellular transition processes (epithelial mesenchymal transition) and fibrosis in unilateral ureteral obstruction. Because these processes are active not only in unilateral ureteral obstruction, but also in other renal diseases, the value of angiotensin II blockade as an important part of the antifibrotic armamentarium has been confirmed.

Angiotensin II Type 1 Receptor Blockers↗
PubMed2006

Self assembled magnetic PVP/PVA hydrogel microspheres; magnetic drug targeting of VX2 auricular tumours using pingyangmycin.

Chemotherapy in cancer treatment is associated with serious side effects and as a result there is great interest in research aimed at bringing down the level of systemic cytotoxicity. With advances in material science, magnetic drug targeting has emerged as one of the viable ways of attaining this. In this study, we used self assembled PVP/PVA magnetic hydrogel microspheres to deliver pingyangmycin (Bleomycin A5) to rabbit auricular VX2 tumours in the presence of a 0.5 T permanent magnet both during and 24 h after perfusion. A total of 22 New Zealand white rabbits ranging from 13 to 16 weeks and weighing 2.5-3.0 kg (2.46 +/- 0.2) successfully implanted with tumours 200-300 mm2 in size were used. In group D (1 mg pingyangmycin in 50 mg ferrofluid without a magnet) 2 weeks post treatment, there was statistically significant difference compared to the control (p = 0.05) in favor of group D. However, when compared to the group with 1 mg pingyangmycin(BLM) in 50 mg of ferrofluid and 0.5 mg (BLM) in 50 mg ferrofluid both with a permanent magnet in place for 24 h, the statistically significant difference was in favor of combined treatment, i.e. ferrofluid carrying drug in presence of a permanent magnet (p = 0.01). The microspheres in conjunction with the magnet did deliver pingyangmycin to the tumour and hence may be of use in future as far as magnetic drug targeting is concerned. However, more studies are still required to establish biodistribution and biostability not to forget drug release of ferrofluid of different chemotherapeutic agents available.

Animals↗
PubMed2006

Identification of valid housekeeping genes and antioxidant enzyme gene expression change in the aging rat liver.

Valid housekeeping genes (HKG) are a prerequisite for accurate gene quantification. We performed real-time reverse transcription-polymerase chain reaction to investigate the gene expression of five commonly used HKGs (beta-actin, glyceraldehyde-3-phosphate dehydrogenase [GAPDH], ubiquitin C [UBC], hypoxanthine phosphoribosyl-transferase [HPRT], and cyclophilin A [CYPa]) and antioxidant enzymes in the liver of young and old male Fischer rats. A wide variation in HKG expression existed during the aging process, and HPRT was identified as the most stable HKG in rat liver aging. When Cu/Zn-superoxide dismutase gene expression was normalized to HPRT, there was no detectable difference between young and old rats; however, a significant difference was seen when it was normalized to UBC. The variation of UBC caused the misinterpretation of Cu/Zn-superoxide dismutase expression. Catalase expression was significantly decreased, whereas glutathione peroxidase expression was not altered with age. We demonstrated that HPRT was an appropriate HKG, validation of HKGs was vital for accurate quantification, and decreased catalase expression might be involved in the decline of antioxidant defenses during rat liver aging.

Age Factors↗
PubMed2006

HIV prevalence among injection drug users in rural Guangxi China.

AIMS: To determine the HIV-1 seroprevalence, risk behaviors and demographic characteristics associated with HIV-1 infection among injection drug users (IDU) in rural Guangxi, China. DESIGN AND SETTING: Between July and November 2002, 702 IDU were screened for HIV-1 antibody through community outreach in rural Guangxi, China for enrollment in an HIV sero-incidence study. PARTICIPANTS: A total of 702 active high-risk IDU were screened. High-risk injection was defined as anyone who reported injecting drugs at least three times per week in the last month or injected drugs with shared equipment on at least three occasions in the last 3 months. MEASUREMENTS: HIV-1 antibody testing with confirmation by Western blot was performed on all subjects. Demographic and risk assessment survey data were collected at screening from everyone whose baseline HIV antibody status was known. FINDINGS: HIV-1 antibody prevalence among 702 IDU at baseline was 25% with a median age of 26.7 years (18.2-43.2). Based on a multivariate logistic regression model using risk factors identified in univariate analyses, the following risk factors were associated significantly with an increase in risk for HIV seropositivity: age > 26 years (OR 1.50; 95% CI 1.04, 2.17), sharing of rinse water (OR = 1.24; 95% CI 1.09, 1.40), not having sex in the last 6 months (OR = 1.62; 95% CI 1.08, 2.43). CONCLUSIONS: HIV infection among IDU in Guangxi, one of China's major HIV epidemic regions, is high and the infection occurs predominantly among older IDU males who share rinse water.

Adolescent↗
PubMed2006

Upregulation of 14-3-3 isoforms in acute rat myocardial injuries induced by burn and lipopolysaccharide.

1. Burn-induced myocardial injuries can be acute due to loss of body fluid and blood redistribution, and subacute due to pathogenic toxins of infecting bacteria. The goal of this study was to examine expression of 14-3-3 in the injured myocardium. 2. Myocardial injury models were created in vivo by subjecting rats to severe burn and administration of lipopolysaccharide. RT-PCR and Western blotting were employed to assess the expression of 14-3-3 proteins and messenger ribonucleic acid (mRNA) for 14-3-3eta and gamma in the myocardium, respectively. 3. In the two models, we found that 14-3-3 proteins were induced in a time-dependent fashion. Such a change is at least in part attributed to increases in mRNAs for 14-3-3gamma and eta. In contrast to 14-3-3xi, whose mRNA was not detectable in the heart, mRNA for 14-3-3gamma was found significantly elevated between 24-48 h after burn. 14-3-3eta mRNA exhibited a marked increase at 3 h continuing to 12 h and then decreased nearly to a normal level after 48 h. In lipopolysaccharide-treated intact rats, 14-3-3gamma mRNA in myocardium showed a significant increase, reaching a peak at 4 h, followed by a decrease at 6 h. In contrast, 14-3-3eta mRNA had a slight increase without significance. 4. Our results suggest that 14-3-3 may play a role in both acute and subacute (postburn infectious) phases of severe burn.

14-3-3 Proteins↗
PubMed2006

[The developmental patterns of GH-R, IGF-1 and IGF-IR gene expression in sheep skin].

Semi-quantitative RT-PCR was applied to investigate the developmental patterns of GH-R, IGF-1 and IGF-IR mRNA expression in skin of two sheep breeds. One breed was the first filial generation (F1) of Romilly Hillys x Merino of China (Xinjiang Agricultural Reclamation line) wool sheep, and the other was Kazak hair sheep. 18S rRNA was used as the internal standard. Sheep were weighed and wool and skin samples were collected at different times. Results showed that body weight increased rapidly during 30-135 days but slowed during 135-255 days. Wool growth increased gradually during 30-135 days, degreased till 180 days of age, but rebounded thereafter. Overall, body weight and developmental patterns of wool growth was not significant different between hair and wool sheep. GH-R mRNA expression in the skin of hair sheep increased significantly during 30-90 days, peaked at 90 days of age (P<0.05), then declined signifi cantly (P<0.05). GH-R mRNA expression in the skin of wool sheep increased significantly until 135 days of age (P<0.01) and then decreased significantly (P<0.01). The peak level was higher in the wool sheep than the hair sheep. The expression of cantly IGF-1 mRNA and IGF-IR mRNA in the skin of hair sheep increased during 30-90 days, then declined significantly (P<0.01). The expression of IGF-1 mRNA and IGF-IR mRNA in the skin of wool sheep were high at birth and then reduced gradually. The IGF-1 mRNA expression in the skin of hair sheep reached its peak at 90 days of age, and was significant higher than that of wool sheep. The expression of GH-R, IGF-1 and IGF-IR mRNA in skin of hair sheep was higher than that of wool sheep before 90 days of age, but was lower after that. The results suggest that GH-R, IGF-1 and IGF-IR mRNA expression in the skin of sheep follows specific developmental patterns, and different patterns exist between the two breeds.

Animals↗
PubMed2006

Bone marrow mesenchymal stem cell transplantation combined with perindopril treatment attenuates infarction remodelling in a rat model of acute myocardial infarction.

OBJECTIVE: This study was performed to evaluate whether implantation of mesenchymal stem cell (MSC) would reduce left ventricular remodelling from the molecular mechanisms compared with angiotensin-converting enzyme inhibitors (ACEIs) perindopril into ischemic myocardium after acute myocardial infarction. METHODS: Forty rats were divided into four groups: control, MSC, ACEI, MSC+ACEI groups. Bone marrow stem cell derived rat was injected immediately into a zone made ischemic by coronary artery ligation in MSC group and MSC+ACEI group. Phosphate-buffered saline (PBS) was injected into control group. Perindopril was administered p.o. to ACEI group and MSC+ACEI group. Six weeks after implantation, the rats were killed and heart sample was collected. Fibrillar collagen was observed by meliorative Masson's trichome stain. Western Blotting was employed to evaluate the protein expression of matrix metalloproteinase (MMP)-2, matrix metalloproteinase (MMP)-9 in infarction zone. The transcriptional level of MMP2, MMP9 and tissue inhibitor of matrix metalloproteinase (TIMP)-1 in infarction area was detected by reverse transcriptase PCR (RT-PCR) analysis. RESULTS: The fibrillar collagen area, the protein expression of MMP2, MMP9 and the transcriptional level of MMP2, MMP9 mRNA in infarction zone reduced in MSC group, ACEI group, and MSC+ACEI group. No significant difference was detected in the expression of TIMP1 mRNA among the 4 groups. CONCLUSION: Both MSC and ACEI could reduce infarction remodelling by altering collagen metabolism.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2006

The cardioprotective peptide, urocortin, activates cardiac KATP channels in adult rat.

Urocortin (UCN), an endogenous cardioprotective peptide, has been reported to activate several ion channels but its effects on the cardiac KATP channels are unknown. In this paper, we showed that adult rat cardiac myocytes had small KATP currents that could be increased 20-fold by pinacidil. UCN also concentration-dependently activated the KATP current and this effect was influenced by ATP and PKA inhibitor peptide, Rp-cAMPS.

Adenosine Triphosphate↗
PubMed2006

Induction of propranolol metabolism by Ginkgo biloba extract EGb 761 in rats.

Ginkgo biloba is one of the most popular herbal medicines in the world, due to its purported pharmacological effects, including memory-enhancing, cognition-improving, and antiplatelet effects. When used in the elderly, Ginkgo has a high potential for interactions with cardiovascular drugs. This study aimed to investigate the effects of the standard Ginkgo biloba extract (EGB 761) treatment on the pharmacokinetics of propranolol and its metabolism to form N-desisopropylpropranolol (NDP) in rats. We also examined the activity and expression of cytochrome P450 (CYP) 1A and other CYPs in rats treated with EGb 761 at 10 and 100 mg/kg/day for 10 days. A single oral dose of propranolol (10 mg/kg) was administered on day 11 and the concentrations of both propranolol and NDP were determined using validated liquid chromatography-mass spectrometry (LC-MS) methods. The levels of mRNA and protein of various CYPs were determined by RT-PCR and Western blotting analysis, respectively. Pretreatment of EGb 761 at 100 mg/kg, but not 10 mg/kg, for 10 days significantly reduced the area under the plasma concentration-time curve (AUC) and maximum plasma concentration (Cmax) of propranolol, whereas those values of NDP were significantly increased. CYP1A1, 1A2, 2B1/2, and 3A1 activities and gene expression in the rat liver were significantly increased in a dose-dependent manner by pretreatment with EGb 761. The ex-vivo formation of NDP in liver microsomes from rats pretreated with EGb 761 was markedly enhanced. The formation of NDP from propranolol in liver microsomes was significantly inhibited by alpha-naphthoflavone (ANF, a selective CYP1A2 inhibitor), but not by quinidine (a CYP2D inhibitor). These results indicated that EGb 761 pretreatment decreased the plasma concentrations of propranolol by accelerated conversion of parental drug to NDP due to induction of CYP1A2. EGb 761 pretreatment also significantly induced CYP2B1/2 and CYP3A1, suggesting potential interactions with substrate drugs for these two enzymes. Further study is needed to explore the potential for gingko-drug interactions and the clinical impact.

Animals↗
PubMed2006

[Viraemia and extraintestinal involvement after rotavirus infection].

OBJECTIVE: To study the incidence of viraemia and extraintestinal organ damage in children with acute rotavirus (RV) gastroenteritis. METHODS: Eighty-three children with acute rotavirus gastroenteritis were hospitalized from October 2002 to March 2003, whose blood and fecal samples were obtained on admission. Rotavirus RNA (encoding the VP7 outer capsid protein) were detected in blood and fecal samples by nest reverse transcription-polymerase chain reaction (RT-PCR). According to the result of blood RV-RNA, the patients were divided into RV-RNA positive group and RV-RNA negative group. The differences between these two groups in the severity of gastroenteritis and extraintestinal organ damage were analyzed. RESULTS: Eighty-two of 83 stool samples from the children with rotavirus infection were positive for rotavirus RNA. Sixteen of 83 blood samples were positive for rotavirus RNA with a positive rate of 19.3%. The nucleotide sequence of cloned cDNAs, resembling part of the VP7 gene, was identical from paired blood and fecal samples. There were no significant differences between blood RV-RNA positive group and blood RV-RNA negative group in the rate and degree of fever, diarrhea, dehydration, metabolic acidosis, hypokalemia and myocardial damage (P>0.05); while the incidences of liver damage, rash, lower respiratory tract infection and the central nervous system involvement in the blood RV-RNA positive group were significantly higher than those in the blood RV-RNA negative group (P<0.05). CONCLUSION: Viraemia is present in the children with acute rotavirus gastroenteritis. Viraemia might be an important mechanism by which rotavirus spread to the extraintestinal sites resulting in organs damage.

Base Sequence↗
PubMed2006

Clinical significance of immunohistochemical expression of hypoxia-inducible factor-1alpha as a prognostic marker in rectal adenocarcinoma.

BACKGROUND: Hypoxia-inducible factor-1alpha (HIF-1alpha), a subunit of hypoxia-inducible factor-1 (HIF-1), furnishes tumor cells with the means of adapting to stress parameters, such as tumor hypoxia, and promotes critical steps in tumor progression and aggressiveness by inducing angiogenesis and regulating energy metabolism. In this study, we investigated the relationship between HIF-1alpha and vascular endothelial growth factor (VEGF) and clinicopathologic characteristics, and evaluated the role of HIF-1alpha expression in patients with rectal adenocarcinoma. PATIENTS AND METHODS: The immunohistochemical expression of HIF-1alpha and VEGF was evaluated in 30 formalin-fixed, paraffin-embedded postoperative rectal adenocarcinoma tissue samples. Correlations with clinicopathologic characteristics were determined by cross-tabulations. The impact of the immunoreactivity of HIF-1alpha with regard to the overall survival and local control endpoints was determined by univariate analyses. RESULTS: Increased HIF-1alpha expression was strongly associated with VEGF positivity (P = 0.002), Dukes stage (P = 0.017), and lymph node metastasis (P = 0.001). No correlation was found between the level of HIF-1alpha expression and histologic grade (P = 0.63). The Kaplan-Meier curves showed a significantly shorter overall survival (P = 0.0087) and local control (P = 0.0438) for patients with high HIF-1alpha expression. CONCLUSION: These results show that HIF-1alpha might represent an important biologic marker evaluating the prognosis of patients with rectal adenocarcinoma.

Adenocarcinoma↗
PubMed2006

[Linkage analysis of five genes in pigs using radiation hybrid clone panel].

RH (radiation hybrid) has proved to be an effective method in constructing human genome maps (including ESTs, STSs and microsatellites). In this study, based on the information of five human genes (FMR1, IDS, FATE, BGN, F8A) on the X chromosome, the linkage relationship of these five genes in pigs were analyzed by a panel of 96 radiation hybrid cell lines. The results showed that FMR1, IDS, FATE, BGN, F8A were in the same linkage group, when LOD was set at 4. When LOD was set at 5, FMR1 and IDS were in the one group, FATE and BGN in the other group, and F8A was in a group by itself.

Animals↗
PubMed2006

[Effects of rare earth elements on soil fauna community structure and their ecotoxicity to Holotrichia parallela].

By the method of OECD filter paper contact, this paper studied the effects of applied rare earth elements on soil fauna community structure and their ecological toxicity to Holotrichia parallela in bean field. The results showed that there were no significant differences between the treatments and the control in soil fauna species, quantity of main species, and diversity index. Urgent and chronic toxic test showed that the differences between the treatments and the control were not significant. It was suggested that within the range of test dosages, rare earth elements had little ecological toxicity to Holotrichia parallela, and did not change the soil fauna community structure.

Animals↗
PubMed2006

[The preventive effectiveness in reducing tooth decay and decalcification of different concentration of fluoride toothpaste for orthodontic patients].

OBJECTIVE: To investigate the preventive effectiveness in reducing tooth decay and decalcification of different concentration of fluoride toothpaste for orthodontic patients. METHODS: 86 patients were divided into the first test group and the second test group. The patients of the first test group brushed tooth with 1.1% sodium fluoride and acidulated phosphate gel. The patients of the second test group brushed tooth with 0.243% sodium fluoride in a silica base. The extent of facial tooth decay and decalcification of the twelve upper and lower teeth from right cuspid to left cuspid was scored blindly and independently by four observers after 12 months of product use. The scores were rated either one (having tooth cavity/decalcification) or zero (no tooth cavity/decalcification). Four observer's readings were averaged per tooth, and then per patient for the two treatment groups. RESULTS: After 12 months of product use, the mean caries score of the first test group was 0.326, and the mean caries score of the second test group was 0.490. There was significant difference between them. CONCLUSION: A gel system containing 1.1% sodium fluoride and acidulated phosphate provides a clinically better efficacy in reducing tooth decay and decalcification than does a toothpaste containing 0.243% sodium fluoride in a silica base under and adjacent to orthodontic brackets used in orthodontic therapy.

Dental Caries↗
PubMed2006

[Expression of glutathione S-transferase zeta class genes in Saccharomyces cerevisiae].

The zeta class of glutathione S-transferase (GSTZs), which is an important multifunctional enzyme, relates to the cell metabolism and contamination elimination. The GSTZ genes from Arabidopsis thaliana L. and Brassica napus L. cv. Shan 2B and Ken C1 were cloned into the multi-cloning site of the shuttle expression vector pYES2. After the recombinants were obtained, the recombinant plasmids were isolated and introduced into the defective mutant INCSc1 of Saccharomyces cerevisiae. Then the recombinant strains Y2At, Y2BnB and Y2BnC were obtained after cultured on SC-U selective plates. When induced in the medium containing galactose and maltose, the recombinant yeast expressed as active GSTZs showing the dichloroacetic acid dechlorinating activity, which existed in the yeast cell as a soluble state. The comparison of different carbon sources showed that sucrose and glucose significantly exhibited the expression of GSTZ gene; glycerol somewhat affected the growth of yeast but increased the specific activity of GSTZ by 17%; and galactose slightly affected the yeast growth with no affection to the activity of GSTZ. Zero to ninety-six hrs induction experiments showed that specific activity of GSTZ in recombinant yeast reached highest when induced for 36 hours. The specific activity of AtGSTZ, BnGSTZ-B and BnGSTZ-C was 5.3 U/mg, 4.3 U/mg and 0.3 U/mg, respectively. The values are lower than that expressed in the E. coli and wheat-sperm cell-free protein synthesis system. However, the relative activity of three sources was similar in E. coli and wheat cell free system. The Km value of GSTZ genes from different sources was 0.59 mmol/L and 0.79 mmol/L for AtGSTZ and BnGSTZ-B, respectively, suggesting the GSTZ enzyme from Abrabidopsis thaliana has higher affinity to DCA than that from Brassica napus.

Arabidopsis↗
PubMed2006

[Comparison of mini-probe endoscopic ultrasonography with computed tomography in preoperative staging of esophageal cancer].

OBJECTIVE: To compare mini-probe endoscopic ultrasonography (MCUS) with computed tomography (CT) in preoperative T and N staging of esophageal cancer, and to find out the MCUS parameters to judge lymph node metastasis for esophageal cancer. METHODS: Thirty-five patients received both MCUS and CT preoperatively, on both of which the T and N stages were determined. The accuracy, sensitivity, specificity, positive predicting value and negative predicting value were compared with the postoperative pathological results. RESULTS: The accuracy of MCUS was 85.7% in T staging and 85.7% and 80.0% in N staging by the two different methods, which were 45.7% and 74.3%, respectively, by CT. CONCLUSION: MCUS is better than CT in preoperative staging for esophageal cancer. The ratio of short to long axis (S/L) combined with short axis is a useful way to determine lymph node metastasis.

Adult↗
PubMed2006

[Efficacy, influencing factors and safety of PEG-INF alpha-2a (PEG-INF-2a) in the treatment of chronic hepatitis C: analysis of 89 patients].

BACKGROUND: To investigate the efficacy, influencing factors and safety of PEG-INF alpha-2a (PEG-INF-2a) in the treatment of hepatitis C. METHODS: Totally 89 patients with hepatitis C were included in this study and 46 patients were treated with PEG-INF-2a (180 microg or 135 microg/week) and RBV 900 mg/d, 43 patients were treated with IFNalpha-2a (5 MIU/qod) and RBV 900 mg/d. The time of treatment was 48 weeks, and all the patients were visited 24 weeks after treatment. There were no significant differences between the two groups in pretreatment HCV-RNA, HCV genotype and other clinical data. The main parameters to evaluate the efficacy were virological and biochemical responses. The side effects were intensively observed. RESULTS: Sustained virological response (SVR) rate in PEG-IFNalpha-2a group was significantly higher than that in IFNalpha-2a group (56.5% and 19.5% respectively, P<0.001). As the patients were divided according to HCV genotype 1 and high virus load, the SVR rate of PEG-INF alpha-2a group was higher than IFNalpha-2a group (P<0.001). However, there was no significant difference between two groups in the patients with non-genotype 1 and low viral load (P=0.664, 0.116). Similar side-effects were observed in PEG-IFNalpha-2a group and IFNalpha-2a group, but the rate of weight decline and the degree of leukocyte decrease were more significant in PEG-INF alpha-2a group than in IFNalpha-2a group (P=0.001). CONCLUSION: The efficacy of PEG-INF alpha-2a in the treatment of chronic hepatitis C is superior to that of conventional IFNalpha-2a, PEG-INF alpha-2a had good tolerance and safety profiles.

Adult↗