Simultaneous quantification of Lamivudine and Zidovudine in tablets by HPTLC method was developed and validated.The chromatograms were developed using a mobile phase of toluene:ethyl acetate:methanol (4:4:2,v/v/v) on ...Simultaneous quantification of Lamivudine and Zidovudine in tablets by HPTLC method was developed and validated.The chromatograms were developed using a mobile phase of toluene:ethyl acetate:methanol (4:4:2,v/v/v) on pre-coated plate of silica gel GF aluminum TLC plate and quantified by densitometric absorbance mode at 276 nm.The R f values were 0.4170.03 and 0.6070.04 for Lamivudine and Zidovudine,respectively.The linearity of the method was found to be within the concentration range of 50 250 ng/spot for Lamivudine and for Zidovudine,it was 100 500 ng/spot.The lower limits of detection and quantification were 2.23 ng/spot and 7.90 ng/spot for Lamivudine and 2.90 ng/spot and 8.85 ng/spot for Zidovudine.The method was also validated for precision,specificity and recovery.This developed method was used to analyze fixed-dose tablets (Duovir,Cipla Ltd) samples of Lamivudine and Zidovudine.展开更多
This paper describes a stripping method for the determination of zidovudine at the submicromolar concentration levels. This method is based on the controlled adsorptive accumulation of zidovudine at the thin-film merc...This paper describes a stripping method for the determination of zidovudine at the submicromolar concentration levels. This method is based on the controlled adsorptive accumulation of zidovudine at the thin-film mercury electrode, followed by a linear-sweep stripping voltammetry measurement of the surface species. Optimal experimental conditions include a NaOH solution of 2.0 × 10–3 mol●L–1 (sup-porting electrolyte), an accumulation potential of –0.30 V and a scan rate of 100 mV?s–1. The response of zidovudine is linear over the concentration range 0.01 - 0.08 ppm. After an accumulation time of 5 minutes, the detection limit was found to be 0.67 ppb (2.5 × 10–9 mol●L–1). More convenient methods to measure zidovudine concentration in the presence of the didanosine, acyclovir, nevirapine, lamivudine, and efavirenz, were also investigated. The presence of zidovudine together with ATP or ssDNA demonstrates the utility of this method.展开更多
Objective: The purpose of this study was to investigate whether switching HIV-infected patients stabilized on Trizivir (abacavir 300 mg/lamivudine 150 mg/zidovudine 300 mg) plus lopinavir/ritonavir 400 mg/100mg twice ...Objective: The purpose of this study was to investigate whether switching HIV-infected patients stabilized on Trizivir (abacavir 300 mg/lamivudine 150 mg/zidovudine 300 mg) plus lopinavir/ritonavir 400 mg/100mg twice daily to Trizivir alone affects clinical efficacy and tolerability. Methods: This phase 4, open-label, pilot study was conducted over 96 weeks in 23 antiretroviral-na?ve, HIV-infected patients. Initially, these patients received induction therapy with Trizivir plus lopinavir/ritonavir 400 mg/100mg twice daily. Patients who achieved a viral load 3. Nineteen patients completed induction;of the four who did not, three were lost to follow-up and one withdrew due to gastrointestinal adverse events. In 14 induction completers who had viral load measurements taken at week 48, intent-to-treat: observed analysis showed a week 48 viral load 3 higher than the baseline count. Twelve patients completed the subsequent 48-week Trizivir-alone maintenance phase, of whom 11 (92%) achieved viral loads of both 3 above baseline. Trizivir-only maintenance was associated with fewer adverse events than the Trizivir-lopinavir/ritonavir induction phase and with improvement in total cholesterol, LDL-cholesterol, and triglycerides. Conclusions: Trizivir-alone maintenance after Trizivir-lopinavir/ritonavir induction maintained virologic and CD4+ cell response, and was associated with an improved adverse event and lipid profile.展开更多
近几年的研究显示通过抑端粒酶活性,干预端粒酶的激活过程,阻断肿瘤细胞的亚性转化,在肿瘤治疗上有重要意义和巨大的潜力[1]。本研究通过端粒酶抑制剂3-叠氮脱氧胸苷（3-azido-deoxythymidine,AZT）作用于人胃癌细胞SGC7901,比较AZT作...近几年的研究显示通过抑端粒酶活性,干预端粒酶的激活过程,阻断肿瘤细胞的亚性转化,在肿瘤治疗上有重要意义和巨大的潜力[1]。本研究通过端粒酶抑制剂3-叠氮脱氧胸苷（3-azido-deoxythymidine,AZT）作用于人胃癌细胞SGC7901,比较AZT作用后癌细胞端粒酶活性的变化,并利用缺口末端标记技术【terminal deoxyribonucleotidyl transferse（TdT）-mediated biotin-16dUTP nick end labeling,TUNEL】和流式细胞术检测AZT作用后肿瘤作用后胃癌细胞SGC7901凋亡情况,进而探讨AZT抑制肿瘤细胞端粒酶可能的机制,为端粒酶抑制剂的临床应用奠定基础。展开更多
AIM: To investigate the synergistic effects of 3'-azido-3'-deoxythymidine (AZT) and FA-2-b-β extracted from Ling Jin mushroom on apoptosis of gastric cancer cells MKN45 in vitro. METHODS: MTT analysis was mad...AIM: To investigate the synergistic effects of 3'-azido-3'-deoxythymidine (AZT) and FA-2-b-β extracted from Ling Jin mushroom on apoptosis of gastric cancer cells MKN45 in vitro. METHODS: MTT analysis was made to examine the inhibition rate of MKN45 cells treated with AZT (2.5, 5, 10 and 20 mg/L) and FA-2-b-β (5, 10, 20 and 40 mg/L) singly and combinatively for 24, 48 and 72 h. Apoptotic effects were evaluated by morphological methods, DNA agarose gel electrophoresis and flow cytometry, respectively. Telomerase activity was estimated by TRAP-ELISA. The mRNA expression of caspase-3 and Bcl-2 were detected by RT-PCR. RESULTS: AZT and FA-2-b-β could signifi cantly inhibit MKN45 cell proliferation and induce its apoptosis. MKN45 cells were inhibited in dose-and time-dependent manner. The inhibition effect of AZT combined with FA-2-b-β was obviously better than that used singly (0.469 ± 0.022 vs 1.075 ± 0.055, P < 0.05, 0.325 ± 0.029 vs 0.469 ± 0.022 P < 0.01). AZT used singly and combination of FA-2-b-β could decrease the activity of tumor cell telomerase, and AZT has synergistic function with FA-2-b-β. A certain concentration of AZT could up-regulate the expression of caspase-3 mRNA (r = 0.9969, P < 0.01), which was positively related to apoptosis rate, and could down-regulate the expression of Bcl-2 mRNA, which was negatively related to apoptosis rate (r = 0.926, P < 0.01). Furthermore, the effect of AZT combined with FA-2-b-β was signifi cantly higher than that used singly.CONCLUSION: Combination of AZT and FA-2-b-β has an obviously synergetic effect in the gastric cancer cells MKN45, which has provided a new approach to the treatment of gastric cancer clinically.展开更多
文摘Simultaneous quantification of Lamivudine and Zidovudine in tablets by HPTLC method was developed and validated.The chromatograms were developed using a mobile phase of toluene:ethyl acetate:methanol (4:4:2,v/v/v) on pre-coated plate of silica gel GF aluminum TLC plate and quantified by densitometric absorbance mode at 276 nm.The R f values were 0.4170.03 and 0.6070.04 for Lamivudine and Zidovudine,respectively.The linearity of the method was found to be within the concentration range of 50 250 ng/spot for Lamivudine and for Zidovudine,it was 100 500 ng/spot.The lower limits of detection and quantification were 2.23 ng/spot and 7.90 ng/spot for Lamivudine and 2.90 ng/spot and 8.85 ng/spot for Zidovudine.The method was also validated for precision,specificity and recovery.This developed method was used to analyze fixed-dose tablets (Duovir,Cipla Ltd) samples of Lamivudine and Zidovudine.
文摘This paper describes a stripping method for the determination of zidovudine at the submicromolar concentration levels. This method is based on the controlled adsorptive accumulation of zidovudine at the thin-film mercury electrode, followed by a linear-sweep stripping voltammetry measurement of the surface species. Optimal experimental conditions include a NaOH solution of 2.0 × 10–3 mol●L–1 (sup-porting electrolyte), an accumulation potential of –0.30 V and a scan rate of 100 mV?s–1. The response of zidovudine is linear over the concentration range 0.01 - 0.08 ppm. After an accumulation time of 5 minutes, the detection limit was found to be 0.67 ppb (2.5 × 10–9 mol●L–1). More convenient methods to measure zidovudine concentration in the presence of the didanosine, acyclovir, nevirapine, lamivudine, and efavirenz, were also investigated. The presence of zidovudine together with ATP or ssDNA demonstrates the utility of this method.
文摘Objective: The purpose of this study was to investigate whether switching HIV-infected patients stabilized on Trizivir (abacavir 300 mg/lamivudine 150 mg/zidovudine 300 mg) plus lopinavir/ritonavir 400 mg/100mg twice daily to Trizivir alone affects clinical efficacy and tolerability. Methods: This phase 4, open-label, pilot study was conducted over 96 weeks in 23 antiretroviral-na?ve, HIV-infected patients. Initially, these patients received induction therapy with Trizivir plus lopinavir/ritonavir 400 mg/100mg twice daily. Patients who achieved a viral load 3. Nineteen patients completed induction;of the four who did not, three were lost to follow-up and one withdrew due to gastrointestinal adverse events. In 14 induction completers who had viral load measurements taken at week 48, intent-to-treat: observed analysis showed a week 48 viral load 3 higher than the baseline count. Twelve patients completed the subsequent 48-week Trizivir-alone maintenance phase, of whom 11 (92%) achieved viral loads of both 3 above baseline. Trizivir-only maintenance was associated with fewer adverse events than the Trizivir-lopinavir/ritonavir induction phase and with improvement in total cholesterol, LDL-cholesterol, and triglycerides. Conclusions: Trizivir-alone maintenance after Trizivir-lopinavir/ritonavir induction maintained virologic and CD4+ cell response, and was associated with an improved adverse event and lipid profile.
文摘近几年的研究显示通过抑端粒酶活性,干预端粒酶的激活过程,阻断肿瘤细胞的亚性转化,在肿瘤治疗上有重要意义和巨大的潜力[1]。本研究通过端粒酶抑制剂3-叠氮脱氧胸苷（3-azido-deoxythymidine,AZT）作用于人胃癌细胞SGC7901,比较AZT作用后癌细胞端粒酶活性的变化,并利用缺口末端标记技术【terminal deoxyribonucleotidyl transferse（TdT）-mediated biotin-16dUTP nick end labeling,TUNEL】和流式细胞术检测AZT作用后肿瘤作用后胃癌细胞SGC7901凋亡情况,进而探讨AZT抑制肿瘤细胞端粒酶可能的机制,为端粒酶抑制剂的临床应用奠定基础。
文摘AIM: To investigate the synergistic effects of 3'-azido-3'-deoxythymidine (AZT) and FA-2-b-β extracted from Ling Jin mushroom on apoptosis of gastric cancer cells MKN45 in vitro. METHODS: MTT analysis was made to examine the inhibition rate of MKN45 cells treated with AZT (2.5, 5, 10 and 20 mg/L) and FA-2-b-β (5, 10, 20 and 40 mg/L) singly and combinatively for 24, 48 and 72 h. Apoptotic effects were evaluated by morphological methods, DNA agarose gel electrophoresis and flow cytometry, respectively. Telomerase activity was estimated by TRAP-ELISA. The mRNA expression of caspase-3 and Bcl-2 were detected by RT-PCR. RESULTS: AZT and FA-2-b-β could signifi cantly inhibit MKN45 cell proliferation and induce its apoptosis. MKN45 cells were inhibited in dose-and time-dependent manner. The inhibition effect of AZT combined with FA-2-b-β was obviously better than that used singly (0.469 ± 0.022 vs 1.075 ± 0.055, P < 0.05, 0.325 ± 0.029 vs 0.469 ± 0.022 P < 0.01). AZT used singly and combination of FA-2-b-β could decrease the activity of tumor cell telomerase, and AZT has synergistic function with FA-2-b-β. A certain concentration of AZT could up-regulate the expression of caspase-3 mRNA (r = 0.9969, P < 0.01), which was positively related to apoptosis rate, and could down-regulate the expression of Bcl-2 mRNA, which was negatively related to apoptosis rate (r = 0.926, P < 0.01). Furthermore, the effect of AZT combined with FA-2-b-β was signifi cantly higher than that used singly.CONCLUSION: Combination of AZT and FA-2-b-β has an obviously synergetic effect in the gastric cancer cells MKN45, which has provided a new approach to the treatment of gastric cancer clinically.
