ObjectiveTo establish multidrugresistance cell substrain of human hepatocellular carcinoma and to investigate its characteristics.MethodsSMMC7721 cell strain was cultured in Adriamycin(ADM). The multidrugresistance cell substrain SMMC7721/ADM was harvested after a long period of culture by gradually increasing the concentration of ADM and its characteristics were investigated. Results①The drug resistance of SMMC7721/ADM to ADM increased by 33.3 times, to Vincristine 16.8 times, to Diamminedichloroplatinum 2.8 times. ②The drug resistance cell substrain had almost the same growth velocity as its parental generation. The doubling time was 32.0 hours and 30.5 hours respectively. They had the analogous growth curves. ③The obvious difference between the drug resistance cell substrain and its parental generation was that the former’s microvilli became thick, short and scattered by scanning and transmitting electron microscopy. ④The multidrug resistance cell substrain kept the characteristics of hepatocellular carcinoma, it could be transplanted into the subcutaneous tissue of nude mice. ⑤The drug resistance of the cell substrain reduced to 28.0% and 9.2%after removal of the drug for 1 month and 2 months respectively, its drug resistance could remain stable (35.4 times) after 2 months of culture in ADM (0.04 μg/ml).ConclusionThe SMMC7721/ADM cell substrain has the stable fundamental characteristics of a drug resistance cell strain.
【Abstract】ObjectiveTo construct a mrp1 expression vector and investigate its biological characteristics in HepG2 cells in vitro. MethodsThe 6.5 kb multidrug resistanceassociated protein （MRP) cDNA obtained from plasmid pGEM-mrp1 was cloned into the pCI-neo mammalian expression vector, which was later transferred into human hepatocarcinoma cell line HepG2 by liposome. Then the HepG2 cells resisting G418 were clustered and proliferated, and the mrp1 mRNA and MRP in these HepG2 cells were detected by means of RT-PCR and FCM respectively. ResultsThe mrp1 expression vector was established successfully, and the stable MDR hepatocarcinoma cell line (HepG2/mrp1) was developed as well. The content of the specific fragment of mrp1 mRNA was (56.8±6.37)% and MRP was 7.89 in the HepG2/mrp1 cells, the corresponding value in HepG2 cells was (9.67±3.26)% and 0.79 respectively. The difference was statistically significant (P＜0.05). ConclusionIt is practicable to establish MDR hepatocarcinoma cell line by transferring mrp1 cDNA into HepG2 cells, which is useful in the research of MDR mechanism.
ObjectiveTo evaluate the effect of neoadjuvant chemotherapy and find the mechanism of multidrug resistance. MethodsTwenty patients with gastric cancer and 31 patients with colorectal cancer underwent neoadjuvant chemotherapy and then operations. The preoperative specimens were stained by immunohistochemical techniques for testing p53,multidrug resistanceassociated protein (MRP), glutathione S transferase（GST）, telomerase. Resection specimens were evaluated for chemotherapy effect by routine histology; at the same time, the postoperative morbidity and mortality were observed. ResultsIn 51 patients, the response rate of neoadjuvant chemotherapy was 27.45%(14/51),so multidrug resistance was a kind of common phenomena in gastrointestinal carcinomas. The postoperative morbidity was 15.69%(8/15), the main operation complication was infection,the mortality was 1.96%(1/51),only one person died from severe infection.The expression rate of p53, MRP, GST, telomerase was 58.0%,51.0%,66.7%,74.0%respectively, the location of p53 was at cell nucleus,location of MRP,GST was at cell memberane and cytoplasm,location of telomerase was at cytoplasm.The response rate had nothing to do with age, sex and metastasis. But it was related with p53 and telomerase expression. ConclusionNeoadjuvant chemotherapy is an effective, safe therapy. But the rate of drug resistance is high in gastrointestinal carcinomas, and the response rate is related to p53, telomerase expression.
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.
Objective To investigate the clinical characteristics and drug sensitivity of patients with Gram-negative bacilli infection, and evaluate the risk factors related to infection, so as to provide a theoretical basis for clinical prevention and treatment of hospital-acquired infection. Methods The complete medical records of 181 patients with Gram-negative bacilli infection in the Department of Respiratory and Critical Care Medicine of Beijing Anzhen Hospital from January 2018 to September 2021 were retrospectively collected. They were divided into a Carbapenem-resistant Gram-negative bacillus (CR-GNB) group and a Carbapenem-sensitive Gram-negative bacillus (CS-GNB) group according to their different sensitivities to carbapenems. Results A total of 238 strains of Gram-negative bacilli were detected, including 108 strains of CR-GNB and 130 strains of CS-GNB. Acinetobacter baumannii was the most common, followed by Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, Escherichia coli and Serratia marcescens. Univariate analysis showed that the risk factors of CR-GNB infection were heart disease and cerebrovascular disease, receiving invasive mechanical ventilation, deep venous catheterization and indwelling catheter, hypoproteinemia, renal insufficiency, pre-infection exposure to tigecycline, carbapenems, vancomycin, polymyxin, and combined use of antibiotics. Hypoproteinemia and deep venous catheterization were independent risk factors for CR-GNB infection. The resistance rates of CR-GNB to cefepime, ceftazidime, levofloxacin and ciprofloxacin were 88.0%, 88.0%, 86.1% and 75.0%, respectively. The resistance rate to cefuroxime, amika, ceftriaxone, gentamicin and cotrimoxazole was low, and the resistance rate to ceftazidime avibactam was the lowest (3.7%). Except tetracycline, tigecycline, cefuroxime, polymyxin, cefazolin and ampicillin, the drug resistance rates of CR-GNB group to other antibacterial drugs were higher than those of CS-GNB group, and the differences were statistically significant (P<0.05). The all-cause mortality in CR-GNB group (42.4%) was significantly higher than that in CS-GNB group (6.3%), and the difference was statistically significant (P<0.05). Conclusions The disease burden caused by CR-GNB infection is becoming heavier and heavier, which has a serious impact on the prognosis of hospitalized patients. The increase of antibiotic resistance leads to poor efficacy of antimicrobial therapy. Therefore, early identification of high-risk groups of infection and reasonable and prudent application of antimicrobial therapy can achieve the purpose of reducing the mortality of infection and improving the prognosis of hospitalized patients.
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.
Objective To investigate the detection of multidrug-resistant organisms (MDRO) by targeted monitoring in a tertiary hospital, and to understand the distribution of MDRO. Methods We retrospectively analyzed the detection and distribution of methicillin-resistantStaphylococcus aureus (MRSA), carbon black alkeneAcinetobacter baumannii (CRABA), carbapenem-resistantPseudomonas aeruginosa (CRPAE), vancomycin-resistantEnterococci (VRE) and carbapenem-resistantEnterobacter (CRE) in clinical samples collected from 2013 to 2015. Results A total of 990 multidrug-resistant bacteria strains were isolated from 2013 to 2015, of which 445 were MRSA (44.95%), 328 were CRABA (33.13%), 99 were CRPAE (10.00%), 12 were VRE (1.21%), and 106 were CRE (10.71%). They were mainly distributed in the Department of Burn, Comprehensive ICU, Department of Neurosurgery, Department of Respiratory Medicine and Department of Orthopedic Surgery. The detection rates of multidrug-resistant organisms of 2013-2015 were 10.85% (352/3 244), 9.20% (304/3 303), and 7.11% (334/4 699) respectively, which reduced year by year with significant difference (χ2= 34.42,P< 0.001). The detection rates of CRPAE, CRE and VRE all reduced with significant differences (P< 0.05). Conclusions The detection rate of multidrug-resistant organisms under targeted monitoring shows an obvious downward trend. MRSA and CRABA are still the major MDROs, which show no obvious change. The detection rates of CRPAE, VRE and CRE show obvious downward trend. Department of Burn, Comprehensive ICU, Department of Neurosurgery, Department of Respiratory Medicine and Department of Orthopedic Surgery have the highest risks of MDRO. In the future, we should strengthen the monitoring of high-risk departments, and focus on the reasonable choice of special antimicrobial agents to avoid special MDROs.
ObjectiveTo investigate the value of serum soluble CD146 (sCD146) in determining acquired epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) resistance in lung adenocarcinoma.MethodsA total of 144 lung adenocarcinoma EGFR sensitive patients in People’s Hospital of Zhengzhou University diagnosed from January 2016 to December 2016 were recruited in the study. According to the different time of taking drugs, the patients were divided into a non-medication group (31 cases), a 1 to 3 month treatment group (25 cases), a 4 to 6 month treatment group (19 cases), a 7 to 12 month treatment group (25 cases), a drug-resistant group (24 cases), and a nonresistant group up to 1 year of treatment (20 cases). The serum levels of sCD146, carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE) were measured by ELISA and chemiluminescence and compared between different period of medication. The relationship of serum sCD146 with tumor markers (CEA, NSE) and tumor related clinical parameters (age, gender, tumor stage, metastasis, tumor diameter, number of the lesions) were analyzed.ResultsThe serum sCD146 level was minimum in the non-medication group that did not receive pioglitazone treatment, highest in the 1 to 3 month treatment group (early treatment period), and declined with duration of medication until resistance occurred without significant difference (P>0.05). The level of sCD146 of the drug-resistant group was significantly lower than that of all nonresistant groups, with significant difference (allP<0.05), but still higher than that of the non-medication group (P<0.05). The serum sCD146 levels in the nonresistant patients with medication over 1 year and within 1 year were similar (P>0.05), and significantly higher than the non-medication group and drug-resistance group (allP<0.05). The serum CEA levels did not differ significantly between 6 groups (P>0.05). The serum NSE level of the 4 to 6 month treatment group was lower than that of the 7 to 12 month treatment group (P<0.05), but both in the normal reference range. The NSE levels did not differ in any other groups (P>0.05). Serum sCD146 was associated with metastasis (P<0.05), but not associated with serum CEA or NSE, nor with sex, age, tumor staging, tumor diameter or lesion number (allP>0.05).ConclusionsCD146 may be involved in the mechanism of TKI killing tumor cells and the mechanism of TKI resistance, and may be a serological marker for monitoring the efficacy of TKI and judging the resistance of TKI.
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(RTPCR). 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.
Objective To investigate nosocomial non-fermented bacterial infection in lower respiratory tract and the risk factors for multi-drug resistant bacterial infection. Methods 229 patients with nosocomial nonfermented bacterial infection in lower respiratory tract from January to December in 2007 in Xiangya Hospital were analyzed retrospectively. The distribution and drug sensitivity of pathogens were recorded. Of those 229 patients,183 cases were infected by non-fermented multi-drug resistant bacteria( MDRB) . The risk factors for non-fermented MDRB infection in lower respiratory tract were analyzed by multi-factor logistic multiple regression analysis.Results The top four non-fermented bacteria isolated were Pseudomonas aeruginosa( 47.6%) , Acinetobacter baumannii( 36. 3% ) , Acinetobacter spp( 8. 6% ) , and Stenotrophomonas maltophilia( 5. 1%) . Higher isolatated rate was found in neurosurgery ( 25. 7% ) and central ICU( 22. 9% ) . The isolated non-fermented bacteria except Stenotrophomonas maltophilia were resistant to all antibiotics except cefoperazone-sulbactam and meropenem. ICU stay( P lt; 0. 001) , tracheotomy or tracheal intubation( P = 0. 001) , and previous use of carbapenemantibiotics( P =0. 032) were independent risk factors for non-fermented MDRB infection. Conclusion Non-fermented bacillus were important pathogens of nosocomial infection in lower respiratory tract with high rates of antibiotic resistance. It is important to prevent non-fermented MDRB infection by strict limitation on the indication of ICU stay,tracheotomy and use of carbapenem.