Ahn To develop a high resolution HPLC method for the determination of ondansetron in human plasma and to study the pharmacokinetics of ondansetron in orally disintegrating tablets. Methods HPLC determination involved ...Ahn To develop a high resolution HPLC method for the determination of ondansetron in human plasma and to study the pharmacokinetics of ondansetron in orally disintegrating tablets. Methods HPLC determination involved liquid-liquid extraction, separation on a CN column and ultraviolet detection at 310 ran with granisetron as an internal standard. Pharmacokinetics and bioequivalence of ondansetron in orally disintegrating tablets by direct compression and conventional 8 mg tablets were evaluated and compared in 20 healthy human male volunteers after a single oral dose in a randomized cross-over study. Results The limit of quantification was 0.25 ng· mL^-1. The recovery was about 85 % or over for ondan setron and about 90% for internal standard. Linearity was good within the concentration range of 0.5 - 50 ng·mL^-1 with r^2 ranging from 0.997 1 to 0.999 9. Intra- and inter-assay coefficients of variation ranged from 1.78% to 2.38% and 3.88% -5.19%, respectively. Accuracies for spiked concentrations of 2.0, 10.0, and 30.0 ng·mL^-1 were 104.7% ±4.4%, 102.2% ± 1.1%, and99.51% ±2.34%, respectively. Pharmacokinetic parameters of AUCo-t, AUCo-∞ , Cmax, Tmax, and T1/2 were 230.2 ± 78.0 ng·h·L^-1 , 265.2± 101.5 ng·h·mL^-1, 35.67 ± 8.94 ng·mL^-l, 1.51 ±0.79 h, and 5.00± 1.41 h for orally disintegrating tablets, respectively. The analysis of variance did not show any significant difference between orally disintegrating tablets and conventional tablets, and 90% confidence intervals fell within the acceptable range for bioequivalence. Conclusion High resolution HPLC method has been set up and applied in pharmacokinetic evaluation of ondansetron in orally disintegrating tablets.展开更多
Bile acids are not only important for the absorption of dietary lipids and fat soluble vitamins but are signalling molecules with diverse endocrine and paracrine functions. Bile acids regulate bile acid, lipid and glu...Bile acids are not only important for the absorption of dietary lipids and fat soluble vitamins but are signalling molecules with diverse endocrine and paracrine functions. Bile acids regulate bile acid, lipid and glucose metabolism and modulate temperature and energy homeostasis. Furthermore, bile acids can not only promote cell proliferation and liver regeneration but can also induce programmed cell death. Bile acid functions are mediated through different pathways which comprise the activation of nuclear hormone receptors, of intracefular kinases and of the plasma membranebound, G-protein coupled bile acid receptor TGRS/Gpbar-1.展开更多
2-Methylisoborneol(2-MIB) is a cyanobacterial metabolite that is responsible for many taste and odor(T&O) complaints related to the aesthetics of drinking water and poses a problem for water authorities because it...2-Methylisoborneol(2-MIB) is a cyanobacterial metabolite that is responsible for many taste and odor(T&O) complaints related to the aesthetics of drinking water and poses a problem for water authorities because it is recalcitrant during conventional water treatment. A numerical model was developed to simulate 2-MIB in the Qingcaosha Reservoir, an estuarine drinking water resource in the Changjiang estuary with known 2-MIB episodes. The objective of this study was to numerically simulate the generation and release processes of 2-MIB in the reservoir and to provide useful information for better management of drinking water resources experiencing T&O problems caused by cyanobacteria. The simulation results from 2009 to 2013 showed that the simulated 2-MIB concentrations corresponded well to the observational data. 2-MIB was released mainly during periods of low dissolved oxygen(DO) levels with an adequate potential sediment source. The temporal and spatial variations in nutrients, chlorophyll-a(Chl-a), Cyanophyta and 2-MIB were presented and analyzed during 2009 to 2013. According to the study results, high-concentration areas and peak levels of 2-MIB can be controlled by inhibiting algal growth and increasing oxygen levels in the water, which can be achieved via adequate water exchange and oxygen exposure in the reservoir, respectively.展开更多
Sulfide-containing waste streams are generated by a number of industries. It is emitted into the environment as dis- solved sulfide (S2- and HS-) in wastewaters and as H2S in waste gases. Due to its corrosive nature, ...Sulfide-containing waste streams are generated by a number of industries. It is emitted into the environment as dis- solved sulfide (S2- and HS-) in wastewaters and as H2S in waste gases. Due to its corrosive nature, biological hydrogen sulfide removal processes are being investigated to overcome the chemical and disposal costs associated with existing chemically based removal processes. The nitrogen and sulfur metabolism interacts at various levels of the wastewater treatment process. Hence, the sulfur cycle offers possibilities to integrate nitrogen removal in the treatment process, which needs to be further optimized by appropriate design of the reactor configuration, optimization of performance parameters, retention of biomass and optimization of biomass growth. The present paper reviews the biotechnological advances to remove sulfides from various environments.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
AimTo characterize the pharmacokinetics of 2 -amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuran osyl) purine (Cyclo-D4G) following intravenous administration and oral administ ration to rats. Methods...AimTo characterize the pharmacokinetics of 2 -amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuran osyl) purine (Cyclo-D4G) following intravenous administration and oral administ ration to rats. MethodsThe concentrations of Cyclo-D4G in rat (Sprague-Dawley male rats) plasma and urine were analyzed by high performance liquid chromatography (HPLC). ResultsFollowing intravenous adm inistration to rats, concentrations of Cyclo-D4G in plasma declined with a term inal phase half-life of 0 78±0 14 h (±s). Total clearance was 0 90±0 21 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximately 20% of total clearance. Steady state volume of distr ibution was 0 91±0 07 L·kg -1 . After oral administration to rats, conce ntrations of Cyclo-D4G in plasma declined with a terminal phase half-life of 0 83±0 13 h (±s). Total clearance was 3 81±2 03 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximat ely 9% of total clearance. Oral bioavailability of Cyclo-D4G in rat was 26 9%. ConclusionThe favorable pharmacokinetic profiles and lower to xicity provide support for further development of Cyclo-D4G clinical trials.展开更多
This review describes the present hot research areas of mangrove-associated fungi, including its biodiversity, ecological roles, novel metabolites productions and biotechnological potential. Mangrove-associated fungi ...This review describes the present hot research areas of mangrove-associated fungi, including its biodiversity, ecological roles, novel metabolites productions and biotechnological potential. Mangrove-associated fungi were divided into saprophytic, parasitic and true symbiotic fungi based on its ecological roles. Saprophytic fungi are fundamental to decomposition and energy flow of mangrove, additionally, their potential toxicity also exists. Pathogenic fungi have significant effects on mangrove survival, growth, and fitness. Endophytic fungi, the most prolific source of diverse bioactive compounds found among that of mangrove-associated fungi, are found in most species of mangroves. Although a significant number of reports focused on the antimicrobial, insecticidal and other bioactive metabolites as well as many novel enzymes isolatcd from mangrove-associated fungi, and many of those metabolites from endophytic fungi are suspected to be of significant to mangrove, only few studies have provided convincing evidence for symbiotic producers in mangrove. Hence, this paper discusses the present progress of molecular methods used to correlate the ecological roles of endophytic fungi with their bioactive metabolites;, meanwhile, the potential of using metabolic engineering and post-genomic approaches to isolate more novel enzymes and bioactive compounds and to make their possible commercial application was also discussed.展开更多
The purpose of this research was to study the pharmacokinetics and the bioavailability of recombinant human parathyroid hormone [rhPTH （1-34）] in Rhesus monkeys after single and multiple subcutaneous administration....The purpose of this research was to study the pharmacokinetics and the bioavailability of recombinant human parathyroid hormone [rhPTH （1-34）] in Rhesus monkeys after single and multiple subcutaneous administration. An immunoradiometric assay （IRMA） was used to determine the plasma drug concentration of rhFFH （1-34） after giving single dose of 10, 20 and 40 ug/kg and daily dose of 40 ug/kg for 7 d by subcutaneous administration, and intravenous injection of 20 ug/kg in Rhesus monkeys. The pharmacokinetic parameters were calculated by noncompartmental analysis. The drug plasma level quantitation range was from 0.027 to 2.22 ng/mL. The intra- and inter-assay precision （CV） of analysis were less than 15%, and the average recovery was about 93.0% ± 8.6% - 116.5% ± 14.0%. After subcutaneous administration of rhPTH（1-34） at dose of 10, 20 and 40 ug/kg, the average Tmax was 0.67, 0.5 and 0.83 h, Cmax were 1.85 ± 0.05, 3.23 ± 0.25 and 7.15 ± 1.19 ng/mL, the AUC（0-∞） were 3.4 ± 0.6, 10.7 ± 1.3 and 12.6 ± 1.5 ng/h/mL, and terminal-phase elimination T1/2 were 0.72 ± 0.10, 1.15 ± 0.10 and 1.03 ± 0.06 h, respectively. The absolute bioavailability of rhPTH （1-34） was 46.96% after subcutaneous administration of 20 ug/kg. There was no evidence of accumulation during systemic exposure of rhPTH （1-34） upon multiple dosing in Rhesus monkeys. The IRMA assay method provide reasonable sensitivity and specificity for the pharrnacokinetic study of rhPTH （1-34） after subcutaneous or intravenous administration in Rhesus monkeys. The pharmacokinetic characteristic of rhPTH （1-34） in monkeys shows linear relationship with the dose administered subcutaneously.展开更多
AIM： To investigate the relationship between the superoxide dismutase （SOD）, malondialdehyde （MDA） metabolic changes and the gastric carcinogenesis.METHODS： The SOD activity and MDA content were measured in the ...AIM： To investigate the relationship between the superoxide dismutase （SOD）, malondialdehyde （MDA） metabolic changes and the gastric carcinogenesis.METHODS： The SOD activity and MDA content were measured in the gastric tissues from the focus center, peripheral and far-end areas of gastric carcinoma （n = 52） arid gastric ulcer （n = 10）. All the tissues were subjected to routine histological examinations and classifications.RESULTS： The SOD activity was greatly reduced but the MDA content was markedly increased in the center areas of the non-mucous gastric carcinoma （non-MGC）; and the poorly differentiated gastric carcinoma varied. The SOD activity was gradually decreased and the MDA content was gradually increased in the tissues from the focus far-end, peripheral to center areas of non-MGC. Both of the SOD activity and the MDA content were significantly declined and were respectively at same low level in the tissues from the focus center, peripheral, and far-end area with the mucous gastric carcinoma （MGC）. In contrast to the gastric ulcer and grade I or II of non-MGC, the same level of the SOD activity and the MDA content were found in the focus center areas. Between non-MGC （groups A-D） and gastric ulcer （group F）, the differences of SOD activity and MDA content were very noticeable in the gastric tissues from the focus peripheral and far-end areas, in which the SOD activity showed noticeable increase and the MDA content showed noticeable decreasein the gastric ulcer.CONCLUSION： The active free radical reaction in the gastric tissues can induce the carcinogenesis of non-MGC. The utmost low ability of antioxidation in the gastric tissues can induce the carcinogenesis of MGC. The metabolic change of the free radicals centralized mostly in the center of ulcerated lesions only, which suggested the ability of antioxidation was declined only in these lesions. However, the metabolism of free radicals varied significantly and the ability of antioxidation declined not only in the local focus area but also in the abroad gastric tissues with gastric carcinoma.展开更多
AIM： To investigate the effect of release behavior of sustained-release dosage forms of sinomenine hydrochloride （SM·HCl） on its pharmacokinetics in beagle dogs. METHODS： The in vitro release behavior of two ...AIM： To investigate the effect of release behavior of sustained-release dosage forms of sinomenine hydrochloride （SM·HCl） on its pharmacokinetics in beagle dogs. METHODS： The in vitro release behavior of two SM·HCl dosage forms, including commercial 12-h sustained-release tablets and 24-h sustained-release pellets prepared in our laboratory, was examined. The two dosage forms were orally administrated to beagle dogs, and then the in vivo SM.HCI pharmacokinetics was investigated and compared. RESULTS： The optimal SM·HCl sustained-release formulation was achieved by mixing slow- and rapidrelease pellets （9：1, w/w）. The SM·HCl release profiles of the sustained-release pellets were scarcely influenced by the pH of the dissolution medium. Release from the 12-h sustained-release tablets was markedly quicker than that from the 24-h sustained-release pellets, the cumulative release up to 12-h was 99.9% vs68.7%. From a pharmacokinetic standpoint, the 24-h SM.HCI sustainedrelease pellets had longer tmax and lower Cmax compared to the 12-h sustained-release tablets, the tmax being 2.67±0.52 h vs 9.83±0.98 h and the Cmax being 1334.45±368.76 ng/mL vs 893.12±292.55 ng/mL, respectively. However, the AUC0-tn of two SM·HCl dosage forms was comparable and both preparations were statistically bioequivalent. Furthermore, the two preparations had good correlations between SM·HCl percentage absorption in vivoand the cumulative percentage release in vitro. CONCLUSION： The in vitro release properties of the dosage forms strongly affect their pharmacokinetic behavior in vivo. Therefore, managing the in vitro release behavior of dosage forms is a promising strategy for obtaining the optimal in vivo pharmacokinetic characteristics and safe therapeutic drug concentration-time curves.展开更多
Natural cocoa butter is expensive but a major ingredient used for the manufacture of chocolate. The search for alternative cheaper cocoa butter substitute with the similar physical properties, fatty acid and triglycer...Natural cocoa butter is expensive but a major ingredient used for the manufacture of chocolate. The search for alternative cheaper cocoa butter substitute with the similar physical properties, fatty acid and triglyceride content has been proposed. The objective of this study was to evaluate the potential ofcbeaper and processed （fractionated- or deodorized-） shea butter （FSB or DSB） to partly substitute 5% and 7.5% cocoa butter in chocolate production. The proximate composition, microbiological and sensory qualities, as well as estimated cost of the formulated chocolate products were determined and compared with that of the 100% cocoa butter chocolate as control. Results showed that all the shea butter substituted chocolate samples varying in percentages of incorporation had acceptable proximate composition and microbial quality according to the international standards. Also, there were no significant differences （P 〉 0.05） among all the five samples in terms of flavour, after-taste and texture except for the 7.5% FSB substituted chocolate which differed significantly （P 〈 0.05） from the other samples in terms of overall acceptability, thus 7.5% FSB was less preferred by consumers. FSB is cheaper than DSB based on the world market price quotes. Thus the current study recommends the use of FSB for chocolate confectioneries at 5% substitution rate for cocoa butter could help reduce the cost of chocolate production and increase turnovers.展开更多
文摘Ahn To develop a high resolution HPLC method for the determination of ondansetron in human plasma and to study the pharmacokinetics of ondansetron in orally disintegrating tablets. Methods HPLC determination involved liquid-liquid extraction, separation on a CN column and ultraviolet detection at 310 ran with granisetron as an internal standard. Pharmacokinetics and bioequivalence of ondansetron in orally disintegrating tablets by direct compression and conventional 8 mg tablets were evaluated and compared in 20 healthy human male volunteers after a single oral dose in a randomized cross-over study. Results The limit of quantification was 0.25 ng· mL^-1. The recovery was about 85 % or over for ondan setron and about 90% for internal standard. Linearity was good within the concentration range of 0.5 - 50 ng·mL^-1 with r^2 ranging from 0.997 1 to 0.999 9. Intra- and inter-assay coefficients of variation ranged from 1.78% to 2.38% and 3.88% -5.19%, respectively. Accuracies for spiked concentrations of 2.0, 10.0, and 30.0 ng·mL^-1 were 104.7% ±4.4%, 102.2% ± 1.1%, and99.51% ±2.34%, respectively. Pharmacokinetic parameters of AUCo-t, AUCo-∞ , Cmax, Tmax, and T1/2 were 230.2 ± 78.0 ng·h·L^-1 , 265.2± 101.5 ng·h·mL^-1, 35.67 ± 8.94 ng·mL^-l, 1.51 ±0.79 h, and 5.00± 1.41 h for orally disintegrating tablets, respectively. The analysis of variance did not show any significant difference between orally disintegrating tablets and conventional tablets, and 90% confidence intervals fell within the acceptable range for bioequivalence. Conclusion High resolution HPLC method has been set up and applied in pharmacokinetic evaluation of ondansetron in orally disintegrating tablets.
文摘Bile acids are not only important for the absorption of dietary lipids and fat soluble vitamins but are signalling molecules with diverse endocrine and paracrine functions. Bile acids regulate bile acid, lipid and glucose metabolism and modulate temperature and energy homeostasis. Furthermore, bile acids can not only promote cell proliferation and liver regeneration but can also induce programmed cell death. Bile acid functions are mediated through different pathways which comprise the activation of nuclear hormone receptors, of intracefular kinases and of the plasma membranebound, G-protein coupled bile acid receptor TGRS/Gpbar-1.
基金Supported by the National Key R&D Program of China(No.2017YFC0405400)the Shanghai Municipal Science and Technology Commission,China(Nos.12231201603,15YF1409900)the Hangzhou Science and Technology Guidance Project in 2016(No.20163501Y54)
文摘2-Methylisoborneol(2-MIB) is a cyanobacterial metabolite that is responsible for many taste and odor(T&O) complaints related to the aesthetics of drinking water and poses a problem for water authorities because it is recalcitrant during conventional water treatment. A numerical model was developed to simulate 2-MIB in the Qingcaosha Reservoir, an estuarine drinking water resource in the Changjiang estuary with known 2-MIB episodes. The objective of this study was to numerically simulate the generation and release processes of 2-MIB in the reservoir and to provide useful information for better management of drinking water resources experiencing T&O problems caused by cyanobacteria. The simulation results from 2009 to 2013 showed that the simulated 2-MIB concentrations corresponded well to the observational data. 2-MIB was released mainly during periods of low dissolved oxygen(DO) levels with an adequate potential sediment source. The temporal and spatial variations in nutrients, chlorophyll-a(Chl-a), Cyanophyta and 2-MIB were presented and analyzed during 2009 to 2013. According to the study results, high-concentration areas and peak levels of 2-MIB can be controlled by inhibiting algal growth and increasing oxygen levels in the water, which can be achieved via adequate water exchange and oxygen exposure in the reservoir, respectively.
基金Project supported by the National Natural Science Foundation ofChina (No. 30070017)the Science and Technology Foundationfor Key Project of Zhejiang Province (No. 2003C13005), China
文摘Sulfide-containing waste streams are generated by a number of industries. It is emitted into the environment as dis- solved sulfide (S2- and HS-) in wastewaters and as H2S in waste gases. Due to its corrosive nature, biological hydrogen sulfide removal processes are being investigated to overcome the chemical and disposal costs associated with existing chemically based removal processes. The nitrogen and sulfur metabolism interacts at various levels of the wastewater treatment process. Hence, the sulfur cycle offers possibilities to integrate nitrogen removal in the treatment process, which needs to be further optimized by appropriate design of the reactor configuration, optimization of performance parameters, retention of biomass and optimization of biomass growth. The present paper reviews the biotechnological advances to remove sulfides from various environments.
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AimTo characterize the pharmacokinetics of 2 -amino-6-cyclopropylamino-9-(2,3-dideoxy-β-D-glyceropent-2-enofuran osyl) purine (Cyclo-D4G) following intravenous administration and oral administ ration to rats. MethodsThe concentrations of Cyclo-D4G in rat (Sprague-Dawley male rats) plasma and urine were analyzed by high performance liquid chromatography (HPLC). ResultsFollowing intravenous adm inistration to rats, concentrations of Cyclo-D4G in plasma declined with a term inal phase half-life of 0 78±0 14 h (±s). Total clearance was 0 90±0 21 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximately 20% of total clearance. Steady state volume of distr ibution was 0 91±0 07 L·kg -1 . After oral administration to rats, conce ntrations of Cyclo-D4G in plasma declined with a terminal phase half-life of 0 83±0 13 h (±s). Total clearance was 3 81±2 03 L·h -1 ·kg -1 . Renal excretion of unchanged Cyclo-D4G accounted for approximat ely 9% of total clearance. Oral bioavailability of Cyclo-D4G in rat was 26 9%. ConclusionThe favorable pharmacokinetic profiles and lower to xicity provide support for further development of Cyclo-D4G clinical trials.
基金Foundation project： This work was supported partly by the Guangzhou Natural Science Foundation （Grant No. 2007Z3-EO581）, the Guangdong Provincial Natural Science Foundation （Grant No. 2007A0200300001-7 05003268）, the Chinese High-Tech 863 Project （Grant No. 2006AA09Z422）, and the National Natural Science Foundation of China （Grant No. 20572136）.
文摘This review describes the present hot research areas of mangrove-associated fungi, including its biodiversity, ecological roles, novel metabolites productions and biotechnological potential. Mangrove-associated fungi were divided into saprophytic, parasitic and true symbiotic fungi based on its ecological roles. Saprophytic fungi are fundamental to decomposition and energy flow of mangrove, additionally, their potential toxicity also exists. Pathogenic fungi have significant effects on mangrove survival, growth, and fitness. Endophytic fungi, the most prolific source of diverse bioactive compounds found among that of mangrove-associated fungi, are found in most species of mangroves. Although a significant number of reports focused on the antimicrobial, insecticidal and other bioactive metabolites as well as many novel enzymes isolatcd from mangrove-associated fungi, and many of those metabolites from endophytic fungi are suspected to be of significant to mangrove, only few studies have provided convincing evidence for symbiotic producers in mangrove. Hence, this paper discusses the present progress of molecular methods used to correlate the ecological roles of endophytic fungi with their bioactive metabolites;, meanwhile, the potential of using metabolic engineering and post-genomic approaches to isolate more novel enzymes and bioactive compounds and to make their possible commercial application was also discussed.
文摘The purpose of this research was to study the pharmacokinetics and the bioavailability of recombinant human parathyroid hormone [rhPTH （1-34）] in Rhesus monkeys after single and multiple subcutaneous administration. An immunoradiometric assay （IRMA） was used to determine the plasma drug concentration of rhFFH （1-34） after giving single dose of 10, 20 and 40 ug/kg and daily dose of 40 ug/kg for 7 d by subcutaneous administration, and intravenous injection of 20 ug/kg in Rhesus monkeys. The pharmacokinetic parameters were calculated by noncompartmental analysis. The drug plasma level quantitation range was from 0.027 to 2.22 ng/mL. The intra- and inter-assay precision （CV） of analysis were less than 15%, and the average recovery was about 93.0% ± 8.6% - 116.5% ± 14.0%. After subcutaneous administration of rhPTH（1-34） at dose of 10, 20 and 40 ug/kg, the average Tmax was 0.67, 0.5 and 0.83 h, Cmax were 1.85 ± 0.05, 3.23 ± 0.25 and 7.15 ± 1.19 ng/mL, the AUC（0-∞） were 3.4 ± 0.6, 10.7 ± 1.3 and 12.6 ± 1.5 ng/h/mL, and terminal-phase elimination T1/2 were 0.72 ± 0.10, 1.15 ± 0.10 and 1.03 ± 0.06 h, respectively. The absolute bioavailability of rhPTH （1-34） was 46.96% after subcutaneous administration of 20 ug/kg. There was no evidence of accumulation during systemic exposure of rhPTH （1-34） upon multiple dosing in Rhesus monkeys. The IRMA assay method provide reasonable sensitivity and specificity for the pharrnacokinetic study of rhPTH （1-34） after subcutaneous or intravenous administration in Rhesus monkeys. The pharmacokinetic characteristic of rhPTH （1-34） in monkeys shows linear relationship with the dose administered subcutaneously.
基金Supported by the Youth Science Fund of Guangdong Province Medicine and Hygiene, No. B19960095
文摘AIM： To investigate the relationship between the superoxide dismutase （SOD）, malondialdehyde （MDA） metabolic changes and the gastric carcinogenesis.METHODS： The SOD activity and MDA content were measured in the gastric tissues from the focus center, peripheral and far-end areas of gastric carcinoma （n = 52） arid gastric ulcer （n = 10）. All the tissues were subjected to routine histological examinations and classifications.RESULTS： The SOD activity was greatly reduced but the MDA content was markedly increased in the center areas of the non-mucous gastric carcinoma （non-MGC）; and the poorly differentiated gastric carcinoma varied. The SOD activity was gradually decreased and the MDA content was gradually increased in the tissues from the focus far-end, peripheral to center areas of non-MGC. Both of the SOD activity and the MDA content were significantly declined and were respectively at same low level in the tissues from the focus center, peripheral, and far-end area with the mucous gastric carcinoma （MGC）. In contrast to the gastric ulcer and grade I or II of non-MGC, the same level of the SOD activity and the MDA content were found in the focus center areas. Between non-MGC （groups A-D） and gastric ulcer （group F）, the differences of SOD activity and MDA content were very noticeable in the gastric tissues from the focus peripheral and far-end areas, in which the SOD activity showed noticeable increase and the MDA content showed noticeable decreasein the gastric ulcer.CONCLUSION： The active free radical reaction in the gastric tissues can induce the carcinogenesis of non-MGC. The utmost low ability of antioxidation in the gastric tissues can induce the carcinogenesis of MGC. The metabolic change of the free radicals centralized mostly in the center of ulcerated lesions only, which suggested the ability of antioxidation was declined only in these lesions. However, the metabolism of free radicals varied significantly and the ability of antioxidation declined not only in the local focus area but also in the abroad gastric tissues with gastric carcinoma.
文摘AIM： To investigate the effect of release behavior of sustained-release dosage forms of sinomenine hydrochloride （SM·HCl） on its pharmacokinetics in beagle dogs. METHODS： The in vitro release behavior of two SM·HCl dosage forms, including commercial 12-h sustained-release tablets and 24-h sustained-release pellets prepared in our laboratory, was examined. The two dosage forms were orally administrated to beagle dogs, and then the in vivo SM.HCI pharmacokinetics was investigated and compared. RESULTS： The optimal SM·HCl sustained-release formulation was achieved by mixing slow- and rapidrelease pellets （9：1, w/w）. The SM·HCl release profiles of the sustained-release pellets were scarcely influenced by the pH of the dissolution medium. Release from the 12-h sustained-release tablets was markedly quicker than that from the 24-h sustained-release pellets, the cumulative release up to 12-h was 99.9% vs68.7%. From a pharmacokinetic standpoint, the 24-h SM.HCI sustainedrelease pellets had longer tmax and lower Cmax compared to the 12-h sustained-release tablets, the tmax being 2.67±0.52 h vs 9.83±0.98 h and the Cmax being 1334.45±368.76 ng/mL vs 893.12±292.55 ng/mL, respectively. However, the AUC0-tn of two SM·HCl dosage forms was comparable and both preparations were statistically bioequivalent. Furthermore, the two preparations had good correlations between SM·HCl percentage absorption in vivoand the cumulative percentage release in vitro. CONCLUSION： The in vitro release properties of the dosage forms strongly affect their pharmacokinetic behavior in vivo. Therefore, managing the in vitro release behavior of dosage forms is a promising strategy for obtaining the optimal in vivo pharmacokinetic characteristics and safe therapeutic drug concentration-time curves.
文摘Natural cocoa butter is expensive but a major ingredient used for the manufacture of chocolate. The search for alternative cheaper cocoa butter substitute with the similar physical properties, fatty acid and triglyceride content has been proposed. The objective of this study was to evaluate the potential ofcbeaper and processed （fractionated- or deodorized-） shea butter （FSB or DSB） to partly substitute 5% and 7.5% cocoa butter in chocolate production. The proximate composition, microbiological and sensory qualities, as well as estimated cost of the formulated chocolate products were determined and compared with that of the 100% cocoa butter chocolate as control. Results showed that all the shea butter substituted chocolate samples varying in percentages of incorporation had acceptable proximate composition and microbial quality according to the international standards. Also, there were no significant differences （P 〉 0.05） among all the five samples in terms of flavour, after-taste and texture except for the 7.5% FSB substituted chocolate which differed significantly （P 〈 0.05） from the other samples in terms of overall acceptability, thus 7.5% FSB was less preferred by consumers. FSB is cheaper than DSB based on the world market price quotes. Thus the current study recommends the use of FSB for chocolate confectioneries at 5% substitution rate for cocoa butter could help reduce the cost of chocolate production and increase turnovers.
