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find Keyword "resistance" 189 results
  • A New Tool for Medical Research ——ATP-Binding Cassette Transporter Families

    Objective  To review the application advancements of ATP-binding cassette (ABC) transporter in medical research.Methods  Relevant literatures about the applications of ABC families in medical research were reviewed. Results  ABC families mainly took roles in transporting substances across cell membrane. Some of them were useful for the prediction of drug resistance and the prognosis of malignant tumors. Others were target s for molecular researches. Their expressions or mutations might be related with the occurrence of diseases. Conclusion ABC families are very important in the diagnosis and therapy for diseases. Thus they are very promising tools for future medical research.

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  • Effects of resveratrol on multidrug resistance in human retinoblastoma cells

    Objective To observe the effect of resveratrol on multidrug resistance (MDR) in human retinoblastoma cells treated. Methods RB cells in logarithmic growth phase were divided into experimental group and control group. RB cells in experimental group were cultured with different concentrations of resveratrol (6.25, 12.50, 25.00, 50.00, 100.00 mu;mol/L) for 24 and 48 hours. The proliferation (absorbance value) was assayed using methyl thiazolyl tetrazolium (MTT). RB cells were cultured with 50.00 mu;mol/L resveratrol for 48 hours. The expressions of MDR-1, cyclooxygenase-2 (COX-2)、multidrug resistance-associated protein-1 (MRP-1), glutathione-S-transferases-pi; (GST-pi;) were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. The RB cells of the control group were cultured with 0.5% dimethyl sulfoxide. Results Compared with the control group, the absorbance value decreased in experimental groups (6.25, 12.50, 25.00, 50.00 mu;mol/L) in a dose dependent manner (F=4.782,P<0.05). The difference of absorbance value between 50.00 and 100.00 mu;mol/L experimental groups was not significant (F=6.351,P>0.05). Compared with the control group, the mRNA (t=9.170, 5.758, 4.152, 4.638) and protein (t=3.848, 5.955, 4.541, 3.514) expression levels of MDR-1, MRP1, COX-2, and GST-pi; decreased in the experimental group (P<0.05). Conclusion Resveratrol can down-regulate the expression of MDR in RB cells.

    Release date:2016-09-02 05:26 Export PDF Favorites Scan
  • Analysis on Preoperative Evaluation of the Operability of Chronic Thromboembolic Pulmonary Hypertension

    Abstract: Objective To analyze the results of preoperative evaluation of the operability of chronic thromboembolic pulmonary hypertension (CTEPH), and to find parameters to define the inconsistency between the operable lesions of CTEPH and pulmonary vascular resistance (PVR). Methods A total of 133 patients with CTEPH admitted into Anzhen Hospital were enrolled for preoperative assessment of operability from March 2002 to May 2010. There were 86 males and 47 females with an age of 49.10±22.70 years. The patients were divided into operable group (group A, n=82,age of 47.80±21.60 years) and inoperable group (group B, n=51, age of 50.30±23.40 years) according to the assessment suggestion. We evaluated the occluded pulmonary segment(OPS) of all the patients through pulmonary ventilation/perfusion scintigraphy, and measured the plasma aminoterminal Btype natriuretic peptide (NT-pro BNP) and PVR. Then the ratio of NT-pro BNP to OPS and PVR to OPS were calculated. [CM(159mm]Results Out of the 82 patients with CTEPH in group A, 81 were positive in the anesthesia test and were subject to pulmonary thromboendarterectomy(PTE). In the whole cohorts of operated patients, there was one early death due to persistent pulmonary hypertension and right heart failure. The specificity of the anesthesia test was 98.78%. Eighty patients (98.77%) were followed up in this group for a period of 1 to 95 months (42.70±28.40 months). During the followup, there was one late death due to pulmonary artery hypertension crisis. Among the 51 patients with CTEPH in group B, there were 32 patients (62.75%) with surgically inaccessible lesions, 13 patients (25.49%) with surgical accessible CTEPH concomitant with severe diseases, and 6 patients (11.76%) with inconsistency between the surgical accessible lesion and high PVR. The ratio of NT-pro BNP to OPS and PVR to OPS for the 81 positive patients in group A was in the range of 80-150 pg·ml-1/OPS and 50-100 dyn·s·cm-5/OPS, respectively. The ratio of NT-pro BNP to OPS (315.00±83.00 pg·ml-1/OPS vs. 115.60±40.50 pg·ml-1/OPS, P=0.000) and PVR to OPS (190.00±57.00 dyn·s·cm-5/OPS vs. 76.40±26.30 dyn·s·cm-5/OPS, P=0.000) for the 6 patients with incosistency between the surgical accessible lesion and high PVR in group B were significantly higher than that for the 81 positive patients in group A. Conclusion Surgically inaccessible CTEPH lesions, CTEPH concomitant with severe diseases, and inconsistency between surgical accessible lesion and high PVR are the three most frequent reasons for denying PTE procedure. The ratio of NTpro BNP to OPS and PVR to OPS may serve as the parameters to define the inconsistency between the surgical accessible lesion and high PVR. Anesthesia test before the PTE procedure may serve as the last evaluation method for the assessment of the operability of CTEPH.

    Release date:2016-08-30 05:57 Export PDF Favorites Scan
  • Research progress and prospects of exosomal microRNAs in bone malignancies

    Bone malignancies exhibit the characteristics of high incidence, poor prognosis, and strong chemoresistance. Exosomal microRNAs can regulate the proliferation of bone malignant cells, improve chemoresistance, influence cell communication and the microenvironment, and have significant potential in the diagnosis and treatment of bone malignancies. Due to their stability, exosomal microRNAs can serve as non-invasive biomarkers for diagnosis and prognosis. However, their widespread application in clinical settings requires standardized research. This review summarizes the progress of exosomal microRNA research in various bone malignancies including osteosarcoma, chondrosarcoma, Ewing sarcoma, and fibrosarcoma, to provide new theoretical foundations and perspectives for the field.

    Release date:2024-12-27 02:33 Export PDF Favorites Scan
  • THE ROLE OF MULTIDRUG RESISTANCE-ASSOCIATED PROTEIN IN THE FORMATION OF ADRIAMYCININDUCED MULTIDRUG RESISTANCE TO HEPATOCELLULAR CANCER CELL SMMC-7721 IN HUMAN HEPATOCELLULAR CARCINOMA

    Objective To dynamically study the formation of multidrug resistance(MDR) of human hepatocellular carcinoma cell SMMC-7721 induced by Adriamycin (ADM) and the role of multidrug resistance-associated protein(MRP) in its mechanisms.Methods Hepatocellular carcinoma cell SMMC-7721 was cultured in RPMI-1640 medium containing ADM with progressively increased concentration or directly cultured in medium containing different concentrations of ADM. Resistant index of drug-resistant variants of SMMC-7721 cell was determined by drawing cell dosage-reaction curves.Levels of MRP mRNA expression were detected by reverse transcription-polymerase chain reaction(RTPCR). Intracellular rubidomycin(DNR) concentration was examined by flow cytometry(FCM).Results With progressive increasing of ADM concentration in medium resistant index and levels of MRP mRNA expression were correspondingly increased but intracellular DNR concentration was markly reduced. When parental cells were directly cultured in medium containing different concentrations of ADM, the higher the ADM concentration, the higher the level of MRP mRNA expression, but intracellular DNR concentration was kept at the similar high level and most cells died. Conclusion ADM may progressively induce SMMC-7721 cell resistant to multiple chemotherapeutic drugs with reduced intracellular DNR accumulation associated with the overexpression of MRP gene.

    Release date:2016-08-28 05:29 Export PDF Favorites Scan
  • Relation between Diabetes and Pedopathy of Type II Diabetes and Insulin Resistance

    摘要:目的:探讨2型糖尿病合并糖尿病足患者与胰岛素抵抗的关系。方法:205例2型糖尿病患伴糖尿病足患者作为观察组,无足部病变的糖尿病患者作为对照组,观察其体重指数、空腹血糖、胰岛素、血脂等指标,两组间进行比较并相关性分析、多元回归分析。胰岛素抵抗指数(HOMAIR)=FPG×FIns/22.5。结果:糖尿病足患者的HOMAIR显著高于无糖尿病的患者(Plt;0.05)。多元回归分析显示糖尿病病程、LDL及BMI是影响2型糖尿病足患者胰岛素抵抗的主要危险因素。结论:糖尿病足患者存在着更严重的胰岛素抵抗。Abstract: Objective: To discuss the relationship between diabetes and pedopathy of type II diabetes and insulin resistance. Methods:The diabetes type II patients were divided into group A (combined with pedopathy) and group B (without pedopathy). The blood glucose and insulin of empty stomach, BMI,Alc and lipid were detected. The insulin resistance index (HOMAIR) was calculated and compared between two groups. Results:The HOMAIR was higher in group A than that in group B (Plt;0.05).The duration of disease,LDL and BMI was positive related with diabetes pedopathy. Conclusion:The insulin resistance was more worse in pedopathy of Type II diabetes.

    Release date:2016-09-08 10:12 Export PDF Favorites Scan
  • The Relation Between Preoperative Pulmonary Artery Pressure and Postoperative Complications in Heart Transplantation Patients and the Prevention and Treatment to Postoperative Complications

    Objective To analyze the relation between preoperative pulmonary artery pressure(PAP) and postoperative complications in heart transplant patients, and summarize the experience of perioperative management of pulmonary hypertension (PH), to facilitate the early period heart function recovery of postoperative heart transplant patients. Methods A total of 125 orthotopic heart transplant patients were divided into two groups according to preoperative pulmonary arterial systolic pressure(PASP) and pulmonary vascular resistance(PVR), pulmonary [CM(1583mm]hypertension group (n=56): preoperativePASPgt;50 mm Hg or PVRgt;5 Wood·U; control group (n=69): preoperative PASP≤50 mmHg and PVR≤5 Wood·U. Hemodynamics index including preoperative cardiac index (CI),preoperative and postoperative PVR and PAP were collected by SwanGanz catheter and compared. The extent of postoperative tricuspid regurgitation was evaluated by echocardiography. Postoperative pulmonary hypertension was treated by diuresis,nitrogen oxide inhaling,nitroglycerin and prostacyclin infusion, continuous renal replacement therapy(CRRT)and extracorporeal membrane oxygenation(ECMO). Results All patients survived except one patient in pulmonary hypertension group died of multiorgan failure and severe infection postoperatively in hospital. Acute right ventricular failure occurred postoperatively in 23 patients, 10 patients used ECMO support, 10 patients with acute renal insufficiency were treated with CRRT. 124 patients were followed up for 2.59 months,7 patients died of multiple organ failure, infection and acute rejection in follow-up period, the survivals in both groups have normal PAP, no significant tricuspid regurgitation. No significant difference in cold ischemia time of donor heart, cardiopulmonary bypass(CPB) and circulation support time between both groups; but the patients of pulmonary hypertension group had longer tracheal intubation time in comparison with the patients of control group (65±119 h vs. 32±38 h, t=2.17,P=0.028). Preoperative PASP,mean pulmonary artery pressure(MPAP) and PVR in pulmonary hypertension group were significantly higher than those in control group, CI was lower in pulmonary hypertension group [PASP 64.30±11.50 mm Hg vs. 35.60±10.20 mm Hg; MPAP 43.20±8.50 mm Hg vs. 24.20±7.20 mm Hg; PVR 4.72±2.26 Wood·U vs. 2.27±1.24 Wood·U; CI 1.93±0.62 L/(min·m2) vs. 2.33±0.56 L/(min·m2); Plt;0.05]. Postoperative early PASP, MPAP and PVR in pulmonary hypertension group were significantly higher than those in control group (PASP 35.40±5.60 mm Hg vs. 31.10±5.70 mm Hg, MPAP 23.10±3.60 mm Hg vs. 21.00±4.00 mm Hg, PVR 2.46±0.78 Wood·U vs. 1.79±0.62 Wood·U; Plt;0.05). Conclusion Postoperative right heart insuficiency is related to preoperative pulmonary hypertension in heart transplant patients. Donor heart can quickly rehabilitate postoperatively by effectively controlling perioperative pulmonary hypertension with good follow-up results.

    Release date:2016-08-30 06:06 Export PDF Favorites Scan
  • The economic evaluation of antibacterial drugs and externalities from antibacterial drug uses: a systematic review

    ObjectiveTo systematically review the health economic evaluation studies in which externalities of antibacterial drug uses were identified.MethodsPubMed, EMbase, The Cochrane Library, CNKI, WanFang Data and VIP databases were electronically searched to collect health economic evaluation studies in which externalities of antibacterial drug uses were identified from inception to December 31st, 2020. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Descriptive analysis was then performed.ResultsA total of 14 studies were included. Negative externalities and their impacts on costs and/or effectiveness were examined in 13 literature, and positive externalities in terms of an improvement in disease control were included in only one study. No study was found in which both negative and positive externalities were included. The methods used to quantify negative externalities included: only costs associated with drug resistance per prescription or per unit were calculated; both costs and health impacts associated with the second/third line treatments followed a treatment failure (due to drug resistance) were calculated using a decision tree. In one study in which positive externalities were measured, both health gain and cost reduction from an improvement in disease control (as a benefit of antibacterial drug uses) were calculated by constructing a dynamic model at the population level.ConclusionsWe propose that both the positive and negative externalities should be included in health economic evaluation. This can be achieved by measuring the relevant costs and health impacts in a broader perspective, using a disease-transmission dynamic model. In addition, to achieve an improved health utility measurement, disability-adjusted-life years rather than quality-adjusted-life years should be encouraged for use. Finally, both costs and effectiveness should be discounted.

    Release date:2021-07-22 06:18 Export PDF Favorites Scan
  • Research on Relevance Between Mitochondrial ATP Synthase and Malignant Tumor

    Mitochondrial adenosine triphosphate (ATP) synthase is the key enzyme of mitochondrial oxidative phosphorylation reaction.The down-regulation of the mitochondrial ATP synthase is a hallmark of most human carcinomas, which is the embodiment of the bioenergetic signature of cancer in the performance of the decreased oxidative phosphorylation and increased aerobic glycolysis. Combining with the bioenergetic signature of cancer, studies showed that mitochondrial ATP synthase and multidrug resistance and adverse prognosis of tumor were closely related. Its mechanisms are related to post-transcriptional regulation of the ATP synthase,the hypermethylation of the ATP synthase gene and the inhibitor peptide of the mitochondrial ATP synthase, called ATP synthase inhibitory factor 1(IF1). In this review, we stress the biological characteristics of mitochondrial ATP synthase and the relationship between ATP synthase and multidrug resistance and prognosis of Malignant tumor, in order to find a new way for tumor therapy.

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  • OVEREXPRESSION OF THE MDRl GENE EXPRESSION IN HUMAN PRIMARY HEPATOCELLU-LAR CARCINOMAS

    We have devised a highly sensitive, specific, and quantitative assay for multidrug resistance (mdr1) mRNA expression based on the reverse transcription-polymerase chain reaction (RT-PCR). mdr1 mRNA levels were detected in 30 human primary hepatocellular carcinoma (PHC) tissue and adjacent liver tissue. Five of the patients had received chemotherapy before hepatectomy. The results show that the level of expression of mdr1 gene is higher in tumor tissue than in adjacent liver tissue. mdr1 gene is overexpressed in PHC after chemotherapy. Furthermore, mdr1 gene expression in the treated tumor adjacent liver tissue is higher than that in untreated tumor adjacent liver tissue. Our results indicated that overexpression of mdr1 gene may be responsible for the intrinsic and acquired drug resistance of PHC.

    Release date:2016-08-29 03:25 Export PDF Favorites Scan
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