Background Recent studies suggest that circulating DNA may be a potential tumor marker for lung cancer, but most of these studies are conducted between healthy controls and lung cancer patients, with few or no benign...Background Recent studies suggest that circulating DNA may be a potential tumor marker for lung cancer, but most of these studies are conducted between healthy controls and lung cancer patients, with few or no benign lung disease patients included. The objective of this study was to evaluate the performance of plasma DNA quantification in discriminating lung cancer from the healthy and benign lung disease.Methods Plasma DNA was extracted with a QIAamp DNA Blood Midi kit and quantified by a PicoGreen dsDNA quantitation kit in 44 healthy individuals, 36 benign lung disease patients and 67 lung cancer patients. Discrimination power was evaluated by the receiver operating characteristic curve. Results Plasma DNA values were significantly increased in lung cancer patients, especially in those with metastases, and in benign lung disease patients compared with that in the healthy individuals (P<0.001, respectively). The values in lung cancer patients were significantly increased compared with that in the benign lung disease patients (P<0.001). The area under the curve was 0.96 [95% confidence interval (CI) 0.92-0.99] for the healthy versus lung cancer, 0.73 (95% CI 0.64-0.83) for lung cancer versus benign lung disease, and 0.86 (95% CI 0.80-0.91) for lung cancer versus the healthy and benign lung disease.Conclusions Plasma DNA quantification has a strong power to discriminate lung cancer from the healthy and from the healthy and benign lung disease, less power to discriminate lung cancer from benign lung disease. Plasma DNA quantification may be useful as a screening tool for lung cancer.展开更多
In this work, an electrochemical sensor was fabricated for determination of an anthracycline, doxorubicin(DOX) as a chemotherapy drug in plasma based on multi-walled carbon nanotubes modified platinum electrode(Pt/MWC...In this work, an electrochemical sensor was fabricated for determination of an anthracycline, doxorubicin(DOX) as a chemotherapy drug in plasma based on multi-walled carbon nanotubes modified platinum electrode(Pt/MWCNTs). DOX was effectively accumulated on the surface of modified electrode and generated a pair of redox peaks at around 0.522 and 0.647 V(vs. Ag/Ag Cl) in Britton Robinson(B-R) buffer(p H 4.0, 0.1 M). The electrochemical parameters including p H, type of buffer, accumulation time, amount of modifier and scan rate were optimized. Under the optimized conditions, there was a linear correlation between cathodic peak current and concentration of DOX in the range of 0.05–4.0 μg/m L with the detection limit of 0.002 μg/m L. The number of electron transfers(n) and electron transfer-coefficient(α) were estimated as 2.0 and 0.25, respectively. The constructed sensor displayed excellent precision, sensitivity, repeatability and selectivity in the determination of DOX in plasma. Moreover, cyclic voltammetry studies of DOX in the presence of DNA showed an intercalation mechanism with binding constant(K_b) of 1.12×10~5L/mol.展开更多
Nasopharyngeal carcinoma(NPC)is common in southern China and Southeast Asia.Epstein-Barr virus(EBV)infection is an important etiology for NPC,and EBV genome can be detected in almost all tumor tissues of NPC in this r...Nasopharyngeal carcinoma(NPC)is common in southern China and Southeast Asia.Epstein-Barr virus(EBV)infection is an important etiology for NPC,and EBV genome can be detected in almost all tumor tissues of NPC in this region.Plasma EBV DNA,when quantitatively analyzed using real-time polymerase chain reaction(PCR),has been developed as a biomarker for NPC.In this review,the different clinical applications of plasma EBV DNA in the management of NPC,including screening,monitoring,and prognostication,are discussed.In addition,the biological issues of circulating EBV DNA,including the molecular nature and clearance kinetics,are also explored.展开更多
We established a quick and reliable method for recovering cell-free seminal DNA （cfsDNA）, by using the binding-washing-elution procedure on the DNA purification column. Low variations （below 15%） among the triplic...We established a quick and reliable method for recovering cell-free seminal DNA （cfsDNA）, by using the binding-washing-elution procedure on the DNA purification column. Low variations （below 15%） among the triplicate values of cfsDNA quantity verified the reproducibility of our cfsDNA recovery method. Similar cfsDNA yield and size distribution between seminal plasma acquired by filtration and centrifugation confirmed the presence of cfsDNA. To investigate the general characterization of cfsDNA, the quantitation and size distribution of cfsDNA from normozoospermic and azoospermic semen were analyzed by real-time PCR and electrophoresis, respectively. CfsDNA concentration in semen with normozoospermia （n = 11） was 1.34 ± 0.65 μg ·mL^-1, whereas a higher cfsDNA concentration was observed in azoospermia （2.56 ± 1.43 μg ·mL^-1, n = 9）. The continuous distribution of DNA fragments ranging from -1 kb to 15 kb and a spectrum of multiples of 180-bp fragments were observed in each normozoospermic and azoospermic sample. Distinct characteristic DNA ladder fragmentations in some azoospermic samples implicated that cfsDNA originate partly from apoptotic cells. CfsDNAs of 36 selected azoospermic patients with known information of Y chromosome microdeletion were subjected to the same microdeletion analysis by multiplex PCR and PCR amplification of sY114 （1 450 bp）. All multiplex PCR reactions with cfsDNA amplified successfully and provided the same result as leukocyte DNA. PCR amplification of sY114 gave a 1 450-bp amplicon as expected. Our data suggested the potential use of cfsDNA in search of biomarker or diagnostic procedures.展开更多
Effect of plasma corona discharges on the pH, whole cell lipids and DNA of bacteria is investigated. Results showed an increase in the acidity levels of water due to plasma reactive species which, however, were not re...Effect of plasma corona discharges on the pH, whole cell lipids and DNA of bacteria is investigated. Results showed an increase in the acidity levels of water due to plasma reactive species which, however, were not responsible for bacterial cell death. No changes in the whole cell lipid contents were observed, while DNA after plasma treatment showed deterioration of the amplified sequences, indicating the possible occurrence of DNA degradation. In conclusion, reactive species produced by plasma discharges affects DNA, possibly contributing to cell death.展开更多
The diagnosis of postradiation nasopharyngeal skull base lesions in petients with nasopharyngeal carcinoma(NPC) is still a tough problem in clinical practice.An early and accurate diagnosis is important for subsequent...The diagnosis of postradiation nasopharyngeal skull base lesions in petients with nasopharyngeal carcinoma(NPC) is still a tough problem in clinical practice.An early and accurate diagnosis is important for subsequent management.We prospectively evaluated the diagnostic value of plasma Epstein-Barr virus(EBV) DNA in detecting postradiation nasopharyngeal skull base lesions in NPC patients.From July 2006 to September 2010,90 patients with postradiation NPC(34 women and 56 men;median age:42 years) met the selection criteria and were recruited in this study.All postradiation nasopharyngeal skull base lesions were found in the latest magnetic resonance imaging(MRI) examinations before endoscopic surgery,and the nasopharyngeal cavity was normal under flexible nasopharyngoscopy.Plasma EBV DNA detection was performed within 2 weeks before endoscopic surgery.A total of 90 endoscopic operations were successfully performed without any postoperative complications.Recurrences confirmed by postoperative pathology were found in 30 patients.The specificity,positive and negative predictive values of plasma EBV DNA detection were better than those of MRI.In addition,combining plasma EBV DNA detection with MRI improved the specificity and positive predictive values of MRI.Plasma EBV DNA detection followed by MRI would help to diagnose recurrence whereas MRI was unable.These results indicate that plasma EBV DNA is an effective and feasible biomarker for detecting postradiation nasopharyngeal skull base lesions in NPC patients.展开更多
Non-invasive prenatal gene diagnosis has been developed rapidly in the recent years, and numerous medical researchers are focusing on it. Such techniques could not only achieve prenatal diagnosis accurately, but also ...Non-invasive prenatal gene diagnosis has been developed rapidly in the recent years, and numerous medical researchers are focusing on it. Such techniques could not only achieve prenatal diagnosis accurately, but also prevent tangential illness in fetuses and thus, reduce the incidence of diseases. Moreover, it is non-invasive prenatal gene diagnosis that prevents potential threaten and danger to both mothers and fetuses. Therefore, it is welcomed by clinical gynecologist and obstetrian, researchers of medical genetics, and especially, pregnancies. This review article touches briefly on the advanced development of using cell-free DNA, RNA in maternal plasma and urine for non-invasive prenatal gene diagnosis.展开更多
文摘Background Recent studies suggest that circulating DNA may be a potential tumor marker for lung cancer, but most of these studies are conducted between healthy controls and lung cancer patients, with few or no benign lung disease patients included. The objective of this study was to evaluate the performance of plasma DNA quantification in discriminating lung cancer from the healthy and benign lung disease.Methods Plasma DNA was extracted with a QIAamp DNA Blood Midi kit and quantified by a PicoGreen dsDNA quantitation kit in 44 healthy individuals, 36 benign lung disease patients and 67 lung cancer patients. Discrimination power was evaluated by the receiver operating characteristic curve. Results Plasma DNA values were significantly increased in lung cancer patients, especially in those with metastases, and in benign lung disease patients compared with that in the healthy individuals (P<0.001, respectively). The values in lung cancer patients were significantly increased compared with that in the benign lung disease patients (P<0.001). The area under the curve was 0.96 [95% confidence interval (CI) 0.92-0.99] for the healthy versus lung cancer, 0.73 (95% CI 0.64-0.83) for lung cancer versus benign lung disease, and 0.86 (95% CI 0.80-0.91) for lung cancer versus the healthy and benign lung disease.Conclusions Plasma DNA quantification has a strong power to discriminate lung cancer from the healthy and from the healthy and benign lung disease, less power to discriminate lung cancer from benign lung disease. Plasma DNA quantification may be useful as a screening tool for lung cancer.
基金the research council of Gachsaran Branch, Islamic Azad University, Iran for supporting this project under Grant no. 25518
文摘In this work, an electrochemical sensor was fabricated for determination of an anthracycline, doxorubicin(DOX) as a chemotherapy drug in plasma based on multi-walled carbon nanotubes modified platinum electrode(Pt/MWCNTs). DOX was effectively accumulated on the surface of modified electrode and generated a pair of redox peaks at around 0.522 and 0.647 V(vs. Ag/Ag Cl) in Britton Robinson(B-R) buffer(p H 4.0, 0.1 M). The electrochemical parameters including p H, type of buffer, accumulation time, amount of modifier and scan rate were optimized. Under the optimized conditions, there was a linear correlation between cathodic peak current and concentration of DOX in the range of 0.05–4.0 μg/m L with the detection limit of 0.002 μg/m L. The number of electron transfers(n) and electron transfer-coefficient(α) were estimated as 2.0 and 0.25, respectively. The constructed sensor displayed excellent precision, sensitivity, repeatability and selectivity in the determination of DOX in plasma. Moreover, cyclic voltammetry studies of DOX in the presence of DNA showed an intercalation mechanism with binding constant(K_b) of 1.12×10~5L/mol.
文摘Nasopharyngeal carcinoma(NPC)is common in southern China and Southeast Asia.Epstein-Barr virus(EBV)infection is an important etiology for NPC,and EBV genome can be detected in almost all tumor tissues of NPC in this region.Plasma EBV DNA,when quantitatively analyzed using real-time polymerase chain reaction(PCR),has been developed as a biomarker for NPC.In this review,the different clinical applications of plasma EBV DNA in the management of NPC,including screening,monitoring,and prognostication,are discussed.In addition,the biological issues of circulating EBV DNA,including the molecular nature and clearance kinetics,are also explored.
基金Acknowledgment The investigation was supported by grants from the National Natural Science Foundation of China （No. 30801144）, by the Specialized Research Fund for the Doctoral Program of Higher Education （No. 200804871092） and by the National Key Technology Research and Development Program for the 10th Five- Year Plan, China （No. 2004BA720A33-01）.
文摘We established a quick and reliable method for recovering cell-free seminal DNA （cfsDNA）, by using the binding-washing-elution procedure on the DNA purification column. Low variations （below 15%） among the triplicate values of cfsDNA quantity verified the reproducibility of our cfsDNA recovery method. Similar cfsDNA yield and size distribution between seminal plasma acquired by filtration and centrifugation confirmed the presence of cfsDNA. To investigate the general characterization of cfsDNA, the quantitation and size distribution of cfsDNA from normozoospermic and azoospermic semen were analyzed by real-time PCR and electrophoresis, respectively. CfsDNA concentration in semen with normozoospermia （n = 11） was 1.34 ± 0.65 μg ·mL^-1, whereas a higher cfsDNA concentration was observed in azoospermia （2.56 ± 1.43 μg ·mL^-1, n = 9）. The continuous distribution of DNA fragments ranging from -1 kb to 15 kb and a spectrum of multiples of 180-bp fragments were observed in each normozoospermic and azoospermic sample. Distinct characteristic DNA ladder fragmentations in some azoospermic samples implicated that cfsDNA originate partly from apoptotic cells. CfsDNAs of 36 selected azoospermic patients with known information of Y chromosome microdeletion were subjected to the same microdeletion analysis by multiplex PCR and PCR amplification of sY114 （1 450 bp）. All multiplex PCR reactions with cfsDNA amplified successfully and provided the same result as leukocyte DNA. PCR amplification of sY114 gave a 1 450-bp amplicon as expected. Our data suggested the potential use of cfsDNA in search of biomarker or diagnostic procedures.
文摘Effect of plasma corona discharges on the pH, whole cell lipids and DNA of bacteria is investigated. Results showed an increase in the acidity levels of water due to plasma reactive species which, however, were not responsible for bacterial cell death. No changes in the whole cell lipid contents were observed, while DNA after plasma treatment showed deterioration of the amplified sequences, indicating the possible occurrence of DNA degradation. In conclusion, reactive species produced by plasma discharges affects DNA, possibly contributing to cell death.
文摘The diagnosis of postradiation nasopharyngeal skull base lesions in petients with nasopharyngeal carcinoma(NPC) is still a tough problem in clinical practice.An early and accurate diagnosis is important for subsequent management.We prospectively evaluated the diagnostic value of plasma Epstein-Barr virus(EBV) DNA in detecting postradiation nasopharyngeal skull base lesions in NPC patients.From July 2006 to September 2010,90 patients with postradiation NPC(34 women and 56 men;median age:42 years) met the selection criteria and were recruited in this study.All postradiation nasopharyngeal skull base lesions were found in the latest magnetic resonance imaging(MRI) examinations before endoscopic surgery,and the nasopharyngeal cavity was normal under flexible nasopharyngoscopy.Plasma EBV DNA detection was performed within 2 weeks before endoscopic surgery.A total of 90 endoscopic operations were successfully performed without any postoperative complications.Recurrences confirmed by postoperative pathology were found in 30 patients.The specificity,positive and negative predictive values of plasma EBV DNA detection were better than those of MRI.In addition,combining plasma EBV DNA detection with MRI improved the specificity and positive predictive values of MRI.Plasma EBV DNA detection followed by MRI would help to diagnose recurrence whereas MRI was unable.These results indicate that plasma EBV DNA is an effective and feasible biomarker for detecting postradiation nasopharyngeal skull base lesions in NPC patients.
文摘Non-invasive prenatal gene diagnosis has been developed rapidly in the recent years, and numerous medical researchers are focusing on it. Such techniques could not only achieve prenatal diagnosis accurately, but also prevent tangential illness in fetuses and thus, reduce the incidence of diseases. Moreover, it is non-invasive prenatal gene diagnosis that prevents potential threaten and danger to both mothers and fetuses. Therefore, it is welcomed by clinical gynecologist and obstetrian, researchers of medical genetics, and especially, pregnancies. This review article touches briefly on the advanced development of using cell-free DNA, RNA in maternal plasma and urine for non-invasive prenatal gene diagnosis.
