Aim To establish a new and sensitive HPLC-MS method for the determination ofzolmitriptan in human plasma and study the pharmacokinetics of zolmitriptan in healthy volunteers.Methods A single oral dose of 5 mg of zolmi...Aim To establish a new and sensitive HPLC-MS method for the determination ofzolmitriptan in human plasma and study the pharmacokinetics of zolmitriptan in healthy volunteers.Methods A single oral dose of 5 mg of zolmitriptan tablet was given to 20 healthy male volunteers.After dosing, blood samples were collected for a period of 24 h, and zolmitriptan concentration inplasma was analyzed by HPLC-MS. Results The plasma concentration-time course fitted well atwo-compartment open model with a lag time, giving the following pharmacokinetic parameters: T_(max)1.60 ± 0.24 h, C_(max) 9.73 ± 1.43 ng·mL^(-1). T_(1/2α)1.72±0.46 h, T_(1/2β) 4.52 + 0.97 h,and AUC_(0-t) 55.59 ± 5.12 ng·mL^(-1)·h. Conclusion The improved analytical method forzolmitriptan is rapid, sensitive and suitable for application to pharmacokinetic studies and routinedetermination of numerous samples.展开更多
Cetyl-chitosan, prepared by reacting chitosan with chlorocetane under alkaline condition, is soluble and spontaneously forms nanoparticles about 100 nm in diameter. Infrared spectra (IR) revealed that there was a subs...Cetyl-chitosan, prepared by reacting chitosan with chlorocetane under alkaline condition, is soluble and spontaneously forms nanoparticles about 100 nm in diameter. Infrared spectra (IR) revealed that there was a substitution reaction mainly on the amine groups of chitosan (CS). By using paracetamol (PCTM) as a model drug, the balanced release concentration of PCTM in phosphate buffer solution (pH=7.4) can be decreased with the increase of degree of substitution alkyl and can be reduced effectively even under a lower PCTM loading.展开更多
[Objective] The experiment aimed to explore release rule of water-soluble chitosan (WSC) in vitro. [Method]The bovine serum albumin(BSA) was taken as a model protein drug and some existing release models such as Kinet...[Objective] The experiment aimed to explore release rule of water-soluble chitosan (WSC) in vitro. [Method]The bovine serum albumin(BSA) was taken as a model protein drug and some existing release models such as Kinetics model, Gompertz model, Weibull model, Higuchi model and Logistic model were used to fit the BSA release profile from WSC carriers. [Result] Except Higuchi model and Logistic model, other models could fit BSA release profile better. [Conclusion] Gompertz two-order kinetics model could fit the release of WSC nano-particles better and model parameters had practical physical meaning.展开更多
Novel hollow Fe3O4 nanoparticles for drug delivery were synthesized via a one-step template- free approach. These nanoparticles were obtained by modifing the Fe3O4 nanoparticles with 3-aminopropyltrimethoxy silane, an...Novel hollow Fe3O4 nanoparticles for drug delivery were synthesized via a one-step template- free approach. These nanoparticles were obtained by modifing the Fe3O4 nanoparticles with 3-aminopropyltrimethoxy silane, and then grafting alginate onto the surface of amine magnetic. The hollow structure of Fe3O4 spheres was characterized by TEM, XRD, and XPS. The M-H hysteresis loop indicated that the magnetic spheres exhibit snperparamagnetic characteristics at room temperature. Daunorubicin acting as a model drug was loaded into the carrier, and the maximum percent of envelop and load were 28.4% and 14.2% respectively. The drug controlled releasing behaviors of the carriers were compared in different pH media.展开更多
Comparative genetic studies have shown that there are widespread synteny and colinearity of the genes among different species within grass family. Rice ( Oryza sativa L.) is a model plant, and analysis of its genome a...Comparative genetic studies have shown that there are widespread synteny and colinearity of the genes among different species within grass family. Rice ( Oryza sativa L.) is a model plant, and analysis of its genome allows us to reveal the common features and the evolutionary rules of the gramineous genomes and accumulate the data for establishment of a common genetic system in the Poaceae. In this study, a rice gene Pib ( 10.3 kb), a map-based cloned gene, and RFLP markers linked with it are used as the tested probes to investigate their homology and physical location among the tested species. Southern blotting analysis showed that there were sequences homologous to Pib in maize genome. Further, Pib was localized onto the chromosomes of O. sativa ssp. indica cv. Guangluai 4, O. officinalis Wall ex Watt and the inbred line of Zea mays cv. Huangzao 4. The results of fluorescence in situ hybridization (FISH) and double-color FISH indicated that a synteny of Pib and RFLP markers linked with Pib existed among the genomes of the three tested species.展开更多
Using splenic cells of BALB/c mice infected with Friend Leukemia Virus (FVA) as a model of erythroid cells, we investigated the action of dexamethasone (Dex) to induce apoptosis of the cells in the presence of erythro...Using splenic cells of BALB/c mice infected with Friend Leukemia Virus (FVA) as a model of erythroid cells, we investigated the action of dexamethasone (Dex) to induce apoptosis of the cells in the presence of erythropoietin (EPO)——an apoptotic inhibitor in developing erythroid cells. The result indicated that after treatment with a certain range of Dex concentrations and prolonged incubation, the cells were characterized by the occurrence of DNA ladders which appeared on agarose electrophoresis. Transmission electron microscopy showed that karyopyknosis, chromatin condensation, dilatation of the perinuclear space, karyorrhexis, cytoplasmic vacuolization and cell fragmentation appeared in the cells depending on the dose of Dex and the treatment time. These results suggest that Dex could induce apoptosis in the developing erythroid cells as in other cells so far reported.展开更多
Fe3O4 magnetic nanoparticles were prepared by the aqueous co-precipitation of FeCl3-6H2O and FeCl2-4H2O with addition of ammonium hydroxide. The conditions for the preparation of Fe3O4 magnetic nanoparticles were opti...Fe3O4 magnetic nanoparticles were prepared by the aqueous co-precipitation of FeCl3-6H2O and FeCl2-4H2O with addition of ammonium hydroxide. The conditions for the preparation of Fe3O4 magnetic nanoparticles were optimized, and Fe3O4 magnetic nanoparticles obtained were characterized systematically by means of transmission electron microscope （TEM）, dynamic laser scattering analyzer （DLS） and X-ray diffraction （XRD）. The results revealed that the magnetic nanoparticles were cubic shaped and dispersive, with narrow size distribution and average diameter of 11.4 nm. It was found that the homogeneous variation of pH value in the solution via the control on the dropping rate of aqueous ammonia played a critical role in size distribution. The magnetic response of the product in the magnetic field was also analyzed and evaluated carefully. A 32.6 mT magnetic field which is produced by four ferromagnets was found to be sufficient to excite the dipole moments of 0.05 g Fe3O4 powder 2 cm far away from the ferromagnets. In conclusion, the Fe3O4 magnetic nanoparticles with excellent properties were competent for the magnetic carders of targeted-drug in future application.展开更多
AIM: Predictive value of serum b2-microglobulin (b2m)levels for virological breakthrough (VB) in HBeAg-negative chronic hepatitis B (CHB) patients under long-term treatment schedules including lamivudine (LAM).METHODS...AIM: Predictive value of serum b2-microglobulin (b2m)levels for virological breakthrough (VB) in HBeAg-negative chronic hepatitis B (CHB) patients under long-term treatment schedules including lamivudine (LAM).METHODS: Serum b2m levels were calculated during treatment in 25 CHB patients under long-term LAM monotherapy (group A) and 12 patients under initial interferon plus LAM treatment followed by LAM monotherapy (group B), using the MEIA technology. We used Cox proportional hazard models in order to investigate the association between serum b2m levels and VB.RESULTS: Seven of 25 patients (28%), 9/25 (36%) and 14/25 (56%) from group A and 0/12, 2/12 (16.6%) and 3/12 (25%) from group B exhibited VB at months 12, 24 and 36 of treatment, respectively. All patients, from both groups, who did not show VB exhibited b2m elevation in mo 3. The duration of b2m elevation was significantly longer in the virological responder's subgroup from group A than the non-responder's one (7.3±2.6 vs 3.8±3.4 mo,P = 0.02). In comparison to group A patients whose b2m levels were increased at 3 mo, patients whose b2m levels were decreased had 4.6 times higher risk of experiencing VB (RR = 4.6, P = 0.024). When baseline variables were simultaneously included in the same Cox model, decreased b2m status was still associated with increased risk of VB (RR = 12.2, P = 0.03).CONCLUSION: In HBeAg-negative CHB patients under either long-term LAM monotherapy or initial combination treatment, serum b2m levels at 3 mo of treatment,compared to baseline ones, might be a predictor of risk for VB.展开更多
AIM: To investigate the safety and efficacy of long-term combination therapy with alpha interferon and lamivudine in non-responsive patients with anti-HBe-positive chronic hepatitis B.METHODS: 34 patients received com...AIM: To investigate the safety and efficacy of long-term combination therapy with alpha interferon and lamivudine in non-responsive patients with anti-HBe-positive chronic hepatitis B.METHODS: 34 patients received combination treatment (1 month lamivudine, 12 month lamivudine+interferon, 6month lamivudine), 24 received lamivudine (12 months),24 received interferon (12 months). Interferon was administered at 6 MU tiw and lamivudine at 100 mg orally once daily. Patients were followed up for 6 months after treatment.RESULTS: At the end of treatment, HBV DNA negativity rates were 88 % with lamivudine+interferon, 99 % with lamivudine and 55 % with interferon, (P=0.004, combination therapy vs. interferon, and P=0.001 lamivudine vs.interferon), and serum transaminase normalization rates were 84 %, 91% and 53 % (P=0.01 combination therapy vs. interferon, and P=0.012 lamivudine vs. interferon). Six months later, HBV DNA negativity rates were 44 % with lamivudine+interferon, 33 % with lamivudine and 25 % with interferon, and serum transaminase normalization rates were 61%, 42 % and 45 %, respectively, without statistical significance. No YMDD variants were observed with lamivudine+interferon (vs. 12 % with lamivudine). The combination therapy appeared to be safe. CONCLUSION: Although viral clearance and transaminase normalization are slower with long-term lamivudine+interferon than that with lamivudine alone, the combination regimen seems to provide more lasting benefits and to protect against the appearance of YMDD variants. Studies with other regimens regarding sequence and duration are needed.展开更多
The effect of cimetidine on the elimination of praziquantel(PQT)in rats was studied. The results showed that cimetidine 100 mg/kg,ip 2 reduced the clearances of intravenous and oral PQT by 60 and 69 percent respective...The effect of cimetidine on the elimination of praziquantel(PQT)in rats was studied. The results showed that cimetidine 100 mg/kg,ip 2 reduced the clearances of intravenous and oral PQT by 60 and 69 percent respectively.Cimetidine also markedly reduced liver blood flow of rats(a reduction of 58%)and inhibited PQT metabolism in hepatic microsomes of rats(an inhibition of 55%). The reduction in clearance of intravenous PQT could be attributed to the result of cimetidine lowering liver blood flow,whereas the reduction in clearance of oral PQT might be related mainly to the inhibition of cimetidine on the activity of hepatic drug-metabolizing enzymes.展开更多
To approach the mechanism of lipopolysaccharide (LPS) in causing acute lung injury (ALI) and the protective effect of rhubarb and dexamethasone, lung specimens were examined with macroscopy, microscopy, electron micro...To approach the mechanism of lipopolysaccharide (LPS) in causing acute lung injury (ALI) and the protective effect of rhubarb and dexamethasone, lung specimens were examined with macroscopy, microscopy, electron microscopy and the biological markers of ALI including lung wet/dry weight, the rate of neutrophils and protein content in the pulmonary alveolar lavage fluid, pulmonary capillary permeability and pulmonary alveolar permeability index were observed. The mechanism of the ALI is mainly due to direct injury of alveolar epithelium and pulmonary vascular endothelium. Rhubarb and dexamethasone could significantly reduce the edema of the lung tissue, decrease the red blood cell exudation, neutrophil infiltration and plasma protein exudation in the alveoli and all the biological markers in comparison with the ALI model rats, indicating they have protective action on vascular endothelium and alveolar epithelium.展开更多
We present a case of fetal liver failure caused by the activation of larnivudine-resistant hepatitis B virus （HBV） nine months after lamivudine treatment. A 57-year old man visited our hospital for the treatment of ...We present a case of fetal liver failure caused by the activation of larnivudine-resistant hepatitis B virus （HBV） nine months after lamivudine treatment. A 57-year old man visited our hospital for the treatment of decornpensated chronic hepatitis B. Lamivudine was started in December 2001. Subsequently, serum HBV was negative for HBV DNA with seroconversion from HBeAg to anti-HBe and improvement of liver function. However, HBV DNA and HBeAg were again detected in September 2002. He was complicated by breakthrough hepatitis and admitted to our hospital in November for severely impaired liver function. Vidarabine treatment was started and serum HBV DNA and alanine aminotransferase （ALT） decreased transiently. However, after the start of m-interferon treatment, HBV DNA level increased and liver function deteriorated. He died 1 mo after admission. An analysis of amino acid sequences in the polymerase region revealed that rtM204I/V with rtLSOI/V occurred at the time of viral breakthrough. After the start of antiviral treatment, rtL180M was detected in addition to rtM204I/V and rtLSOI/V, and became predominant in the terminal stage of the disease. HBV clone with a high replication capacity may be produced by antiviral treatment leading to the worsening of liver function. Antiviral therapy for patients with breakthrough hepatitis in advanced liver disease should be carefully performed.展开更多
文摘Aim To establish a new and sensitive HPLC-MS method for the determination ofzolmitriptan in human plasma and study the pharmacokinetics of zolmitriptan in healthy volunteers.Methods A single oral dose of 5 mg of zolmitriptan tablet was given to 20 healthy male volunteers.After dosing, blood samples were collected for a period of 24 h, and zolmitriptan concentration inplasma was analyzed by HPLC-MS. Results The plasma concentration-time course fitted well atwo-compartment open model with a lag time, giving the following pharmacokinetic parameters: T_(max)1.60 ± 0.24 h, C_(max) 9.73 ± 1.43 ng·mL^(-1). T_(1/2α)1.72±0.46 h, T_(1/2β) 4.52 + 0.97 h,and AUC_(0-t) 55.59 ± 5.12 ng·mL^(-1)·h. Conclusion The improved analytical method forzolmitriptan is rapid, sensitive and suitable for application to pharmacokinetic studies and routinedetermination of numerous samples.
文摘Cetyl-chitosan, prepared by reacting chitosan with chlorocetane under alkaline condition, is soluble and spontaneously forms nanoparticles about 100 nm in diameter. Infrared spectra (IR) revealed that there was a substitution reaction mainly on the amine groups of chitosan (CS). By using paracetamol (PCTM) as a model drug, the balanced release concentration of PCTM in phosphate buffer solution (pH=7.4) can be decreased with the increase of degree of substitution alkyl and can be reduced effectively even under a lower PCTM loading.
基金Supported by the National Natural Science Foundation of China(20776054)~~
文摘[Objective] The experiment aimed to explore release rule of water-soluble chitosan (WSC) in vitro. [Method]The bovine serum albumin(BSA) was taken as a model protein drug and some existing release models such as Kinetics model, Gompertz model, Weibull model, Higuchi model and Logistic model were used to fit the BSA release profile from WSC carriers. [Result] Except Higuchi model and Logistic model, other models could fit BSA release profile better. [Conclusion] Gompertz two-order kinetics model could fit the release of WSC nano-particles better and model parameters had practical physical meaning.
文摘Novel hollow Fe3O4 nanoparticles for drug delivery were synthesized via a one-step template- free approach. These nanoparticles were obtained by modifing the Fe3O4 nanoparticles with 3-aminopropyltrimethoxy silane, and then grafting alginate onto the surface of amine magnetic. The hollow structure of Fe3O4 spheres was characterized by TEM, XRD, and XPS. The M-H hysteresis loop indicated that the magnetic spheres exhibit snperparamagnetic characteristics at room temperature. Daunorubicin acting as a model drug was loaded into the carrier, and the maximum percent of envelop and load were 28.4% and 14.2% respectively. The drug controlled releasing behaviors of the carriers were compared in different pH media.
文摘Comparative genetic studies have shown that there are widespread synteny and colinearity of the genes among different species within grass family. Rice ( Oryza sativa L.) is a model plant, and analysis of its genome allows us to reveal the common features and the evolutionary rules of the gramineous genomes and accumulate the data for establishment of a common genetic system in the Poaceae. In this study, a rice gene Pib ( 10.3 kb), a map-based cloned gene, and RFLP markers linked with it are used as the tested probes to investigate their homology and physical location among the tested species. Southern blotting analysis showed that there were sequences homologous to Pib in maize genome. Further, Pib was localized onto the chromosomes of O. sativa ssp. indica cv. Guangluai 4, O. officinalis Wall ex Watt and the inbred line of Zea mays cv. Huangzao 4. The results of fluorescence in situ hybridization (FISH) and double-color FISH indicated that a synteny of Pib and RFLP markers linked with Pib existed among the genomes of the three tested species.
文摘Using splenic cells of BALB/c mice infected with Friend Leukemia Virus (FVA) as a model of erythroid cells, we investigated the action of dexamethasone (Dex) to induce apoptosis of the cells in the presence of erythropoietin (EPO)——an apoptotic inhibitor in developing erythroid cells. The result indicated that after treatment with a certain range of Dex concentrations and prolonged incubation, the cells were characterized by the occurrence of DNA ladders which appeared on agarose electrophoresis. Transmission electron microscopy showed that karyopyknosis, chromatin condensation, dilatation of the perinuclear space, karyorrhexis, cytoplasmic vacuolization and cell fragmentation appeared in the cells depending on the dose of Dex and the treatment time. These results suggest that Dex could induce apoptosis in the developing erythroid cells as in other cells so far reported.
基金the Technology Project of Jiangxi Provincial Education DepartmentJiangxi Provincial Science Department
文摘Fe3O4 magnetic nanoparticles were prepared by the aqueous co-precipitation of FeCl3-6H2O and FeCl2-4H2O with addition of ammonium hydroxide. The conditions for the preparation of Fe3O4 magnetic nanoparticles were optimized, and Fe3O4 magnetic nanoparticles obtained were characterized systematically by means of transmission electron microscope （TEM）, dynamic laser scattering analyzer （DLS） and X-ray diffraction （XRD）. The results revealed that the magnetic nanoparticles were cubic shaped and dispersive, with narrow size distribution and average diameter of 11.4 nm. It was found that the homogeneous variation of pH value in the solution via the control on the dropping rate of aqueous ammonia played a critical role in size distribution. The magnetic response of the product in the magnetic field was also analyzed and evaluated carefully. A 32.6 mT magnetic field which is produced by four ferromagnets was found to be sufficient to excite the dipole moments of 0.05 g Fe3O4 powder 2 cm far away from the ferromagnets. In conclusion, the Fe3O4 magnetic nanoparticles with excellent properties were competent for the magnetic carders of targeted-drug in future application.
文摘AIM: Predictive value of serum b2-microglobulin (b2m)levels for virological breakthrough (VB) in HBeAg-negative chronic hepatitis B (CHB) patients under long-term treatment schedules including lamivudine (LAM).METHODS: Serum b2m levels were calculated during treatment in 25 CHB patients under long-term LAM monotherapy (group A) and 12 patients under initial interferon plus LAM treatment followed by LAM monotherapy (group B), using the MEIA technology. We used Cox proportional hazard models in order to investigate the association between serum b2m levels and VB.RESULTS: Seven of 25 patients (28%), 9/25 (36%) and 14/25 (56%) from group A and 0/12, 2/12 (16.6%) and 3/12 (25%) from group B exhibited VB at months 12, 24 and 36 of treatment, respectively. All patients, from both groups, who did not show VB exhibited b2m elevation in mo 3. The duration of b2m elevation was significantly longer in the virological responder's subgroup from group A than the non-responder's one (7.3±2.6 vs 3.8±3.4 mo,P = 0.02). In comparison to group A patients whose b2m levels were increased at 3 mo, patients whose b2m levels were decreased had 4.6 times higher risk of experiencing VB (RR = 4.6, P = 0.024). When baseline variables were simultaneously included in the same Cox model, decreased b2m status was still associated with increased risk of VB (RR = 12.2, P = 0.03).CONCLUSION: In HBeAg-negative CHB patients under either long-term LAM monotherapy or initial combination treatment, serum b2m levels at 3 mo of treatment,compared to baseline ones, might be a predictor of risk for VB.
文摘AIM: To investigate the safety and efficacy of long-term combination therapy with alpha interferon and lamivudine in non-responsive patients with anti-HBe-positive chronic hepatitis B.METHODS: 34 patients received combination treatment (1 month lamivudine, 12 month lamivudine+interferon, 6month lamivudine), 24 received lamivudine (12 months),24 received interferon (12 months). Interferon was administered at 6 MU tiw and lamivudine at 100 mg orally once daily. Patients were followed up for 6 months after treatment.RESULTS: At the end of treatment, HBV DNA negativity rates were 88 % with lamivudine+interferon, 99 % with lamivudine and 55 % with interferon, (P=0.004, combination therapy vs. interferon, and P=0.001 lamivudine vs.interferon), and serum transaminase normalization rates were 84 %, 91% and 53 % (P=0.01 combination therapy vs. interferon, and P=0.012 lamivudine vs. interferon). Six months later, HBV DNA negativity rates were 44 % with lamivudine+interferon, 33 % with lamivudine and 25 % with interferon, and serum transaminase normalization rates were 61%, 42 % and 45 %, respectively, without statistical significance. No YMDD variants were observed with lamivudine+interferon (vs. 12 % with lamivudine). The combination therapy appeared to be safe. CONCLUSION: Although viral clearance and transaminase normalization are slower with long-term lamivudine+interferon than that with lamivudine alone, the combination regimen seems to provide more lasting benefits and to protect against the appearance of YMDD variants. Studies with other regimens regarding sequence and duration are needed.
文摘The effect of cimetidine on the elimination of praziquantel(PQT)in rats was studied. The results showed that cimetidine 100 mg/kg,ip 2 reduced the clearances of intravenous and oral PQT by 60 and 69 percent respectively.Cimetidine also markedly reduced liver blood flow of rats(a reduction of 58%)and inhibited PQT metabolism in hepatic microsomes of rats(an inhibition of 55%). The reduction in clearance of intravenous PQT could be attributed to the result of cimetidine lowering liver blood flow,whereas the reduction in clearance of oral PQT might be related mainly to the inhibition of cimetidine on the activity of hepatic drug-metabolizing enzymes.
文摘To approach the mechanism of lipopolysaccharide (LPS) in causing acute lung injury (ALI) and the protective effect of rhubarb and dexamethasone, lung specimens were examined with macroscopy, microscopy, electron microscopy and the biological markers of ALI including lung wet/dry weight, the rate of neutrophils and protein content in the pulmonary alveolar lavage fluid, pulmonary capillary permeability and pulmonary alveolar permeability index were observed. The mechanism of the ALI is mainly due to direct injury of alveolar epithelium and pulmonary vascular endothelium. Rhubarb and dexamethasone could significantly reduce the edema of the lung tissue, decrease the red blood cell exudation, neutrophil infiltration and plasma protein exudation in the alveoli and all the biological markers in comparison with the ALI model rats, indicating they have protective action on vascular endothelium and alveolar epithelium.
文摘We present a case of fetal liver failure caused by the activation of larnivudine-resistant hepatitis B virus （HBV） nine months after lamivudine treatment. A 57-year old man visited our hospital for the treatment of decornpensated chronic hepatitis B. Lamivudine was started in December 2001. Subsequently, serum HBV was negative for HBV DNA with seroconversion from HBeAg to anti-HBe and improvement of liver function. However, HBV DNA and HBeAg were again detected in September 2002. He was complicated by breakthrough hepatitis and admitted to our hospital in November for severely impaired liver function. Vidarabine treatment was started and serum HBV DNA and alanine aminotransferase （ALT） decreased transiently. However, after the start of m-interferon treatment, HBV DNA level increased and liver function deteriorated. He died 1 mo after admission. An analysis of amino acid sequences in the polymerase region revealed that rtM204I/V with rtLSOI/V occurred at the time of viral breakthrough. After the start of antiviral treatment, rtL180M was detected in addition to rtM204I/V and rtLSOI/V, and became predominant in the terminal stage of the disease. HBV clone with a high replication capacity may be produced by antiviral treatment leading to the worsening of liver function. Antiviral therapy for patients with breakthrough hepatitis in advanced liver disease should be carefully performed.
