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1.
Article in Chinese | WPRIM | ID: wpr-879157

ABSTRACT

A comprehensive analytical method based on ultra-fast liquid chromatography coupled with triple quadrupole/linear ion trap tandem mass spectrometry(UFLC-QTRAP-MS/MS) was established for simultaneous determination of the content of 38 active components in Abelmoschi Corolla, including flavonoids, organic acids, nucleosides and amino acids, so as to investigate the effects of different harvesting and processing methods on multi-active components in Abelmoschi Corolla. The chromatographic separation was performed on a XBridg®C_(18) column(4.6 mm×100 mm, 3.5 μm) with(0.1% formic acid water) methanol-acetonitrile(1∶1) as the mobile phase for gradient elution at 30 ℃. The flow rate was 0.5 mL·min~(-1). The components were detected in a multiple-reaction monitoring(MRM) mode. The gray relational analysis(GRA) was used to comprehensively evaluate the multiple active components of Abelmoschi Corolla at different harvesting times and drying temperatures. The results showed that 38 components had a good linearity with correlation coefficients all above 0.999 0. The method featured a good precision, repeatability and stability with the relative stan-dard deviations(RSDs) of less than 5.0%. Recoveries ranged from 98.06% to 104.4% with RSD between 0.22% and 4.9%. The results of GRA indicated that a better quality in the samples collected on September 9 th. Samples dried at 90 ℃ had a better quality. The established method is accurate and reliable, and can be used to assess the internal quality of Abelmoschi Corolla. This study can provide basic materials for determining appropriate harvesting time and processing method of Abelmoschi Corolla.


Subject(s)
Amino Acids , Chromatography, High Pressure Liquid , Chromatography, Liquid , Nucleosides , Tandem Mass Spectrometry
2.
Article in Chinese | WPRIM | ID: wpr-828370

ABSTRACT

By using multivariate statistical analysis to evaluate essential quality, and provide scientific basis for their comprehensive utilization, we established an UHPLC-QTRAP-MS/MS method for the fast, precise, efficient determination of 21 kinds of amino acids and 10 kinds of nucleosides in different species of Dendrobium. The analysis was performed on a Waters XBridge Amide column(2.1 mm×100 mm,3.5 μm) with elution by mobile phase of 0.2% formic acid in water-0.2% formic acid in acetonitrile at a flow rate of 0.2 mL·min~(-1) with the column temperature at 30 ℃. The target compounds were analyzed by the positive ion multiple reaction monitoring(MRM) mode. The comprehensive evaluation of different species of Dendrobium was carried out by PCA and TOPSIS analysis. All 21 kinds of amino acids and 10 nucleosides showed good linearity among certain concentration range(r>0.999), the RSDs of the stability, precision, and repeatability tests were less than 3.0%. The recovery rate was in the range from 93.31% to 107.5%, and RSD was in the range of 1.1%-3.7%. The comprehensive evaluation index obtained with PCA showed that D. huoshanense was significantly higher than others regarding amino acids and D. officinale has higher nucleosides than other species. The biggest C_i difference of TOPSIS was 68.7%, and comprehensive evaluation showed that D. huoshanense produced the highest comprehensive quality. The method is precise, fast and efficient and can provide reliable basis for further researches and intrinsic quality control of Dendrobium.


Subject(s)
Amino Acids , Chromatography, High Pressure Liquid , Dendrobium , Nucleosides , Tandem Mass Spectrometry
3.
Article in Chinese | WPRIM | ID: wpr-773140

ABSTRACT

The aim of this paper was to compare the influence of freeze-drying and sun-drying on six main nucleosides and nucleobases of Cordyceps sinensis by HPLC. Hypoxanthine,xanthine,uridine,inosine,guanosine and adenosine were reference substances. HPLC analysis was performed on a GL Inertsustain AQ-C_(18) column( 4. 6 mm×250 mm,5 μm),with mobile phase consisting of water( A)-acetonitrile( B) at the flow rate of 1. 0 mL·min~(-1)( 0-10 min,0-1% B; 10-65 min,1%-3% B). The detection wavelength was 260 nm,the column temperature was controlled at 30 ℃,and the injection volume was 5 μL. The linear ranges of hypoxanthine,xanthine,uridine,inosine,guanosine and adenosine were 1. 025-20. 50( r = 0. 999 8),0. 545-10. 90( r = 0. 999 9),4. 051-81. 02( r = 0. 999 8),4. 044-80. 88( r= 0. 999 9),2. 075-41. 50( r= 0. 999 9),4. 032-80. 64( r = 0. 999 9) mg·L~(-1),respectively. The average recoveries of them( n = 6)were as follows: 102. 3%( RSD 2. 1%),101. 1%( RSD 2. 4%),97. 80%( RSD 1. 7%),101. 8%( RSD 1. 8%),98. 90%( RSD2. 0%) and 98. 10%( RSD 1. 4%),respectively. Each sample was processed by freeze-drying and sun-drying so as to compare the difference between the two drying methods. The contents of six index ingredients were significantly different between freeze-drying and sun-drying sample of C. sinensis. The total contents of six index ingredients in sun-drying sample were higher than that in the corresponding freeze-drying sample. This research results provide the scientific basis for the drying methods and quality evaluation of C. sinensis.


Subject(s)
Chromatography, High Pressure Liquid , Cordyceps , Chemistry , Desiccation , Freeze Drying , Nucleosides
4.
Article in Chinese | WPRIM | ID: wpr-773139

ABSTRACT

Online gradient extraction-high performance liquid chromatography( HPLC) method was developed for simultaneous determination of high and low polar components in Cordyceps. The sample powder of Cordyceps was uniformly mixed with diatomaceous earth,packed into extraction tank,and installed into the HPLC system. Online gradient extraction was conducted with mobile phase at 70 ℃. The separation was performed on Zorbax SB-AQ( 4. 6 mm×150 mm,5 μm) column with 0. 1% formic acid solution-methanol as the mobile phase for gradient elution at 1. 0 mL·min~(-1). The column temperature was 30 ℃,and detection wavelength was set at 260 nm. The results showed that the high and low polar components in Cordyceps could be simultaneously extracted and separated by the developed method. Meanwhile,six high polar compounds( uracil,uridine,thymine,inosine,guanosine and adenosine) and one low polar compound( ergosterol) were identified by comparison with the reference peaks. The established method is rapid,stable and environment friendly,which is helpful to improve the quality evaluation level for Cordyceps.


Subject(s)
Chromatography, High Pressure Liquid , Cordyceps , Chemistry , Ergosterol , Nucleosides
5.
Chinese Journal of Hepatology ; (12): 343-346, 2019.
Article in Chinese | WPRIM | ID: wpr-773067

ABSTRACT

Oral nucleos(t)ide analogues (NAs) is one of the main and efficient way for the treatment of chronic hepatitis B (CHB). Considering the antiviral potency and drug resistance of domestic and foreign guidelines, NAs are divided into first-line and non-first-line drugs. "An Expert Consensus for the Adjustment of Treatment Strategies in Patients with Chronic Hepatitis B Treated with Non-first-line Nucleos(t)ide Analogues," is mainly aimed at those patients who are currently using non-first-line NAs drugs. In addition, how to standardize the adjustment to first-line NAs drugs of choice, which can strengthen the effectiveness of initial antiviral treatment to obtain better antiviral efficacy, and improve patient compliance, coinciding with the avoidance of occurrence of serious drug adverse reactions in patients with CHB is presented.


Subject(s)
Antiviral Agents , Therapeutic Uses , Consensus , Guidelines as Topic , Reference Standards , Hepatitis B virus , Hepatitis B, Chronic , Drug Therapy , Humans , Nucleosides , Therapeutic Uses , Outcome Assessment, Health Care , Methods , Practice Guidelines as Topic , Treatment Outcome
6.
Article in English | AIM | ID: biblio-1270077

ABSTRACT

In managing HIV/AIDS with highly active antiretroviral agents, the historical therapeutic aim remains to maintain the plasma concentrations at a level above the half maximal inhibitory concentration (IC50) required for 50% inhibition in viral replication.Concentration dependent toxicity is often observed in patients with elevated drug exposure and high peak plasma levels in lieu of accurately calculated drug dosages. Similarly lowplasmaconcentrationsarefrequently witnessed in individuals receiving adequate dosage regimens. Pharmacogenetic variations in drug metabolizing enzymes may contribute to this phenomenon.Over the last decade, knowledge about the role of pharmacogenetics in the treatment and prediction of ARV plasma levels have increased significantly. However, the extent of these genetic variations remain largely unknown in the South African population,which has sparked a renewed enthusiasm forlocalpharmacogenetic studies


Subject(s)
Delavirdine , Nucleosides , Polymorphism, Genetic , Protease Inhibitors , Reverse Transcriptase Inhibitors
7.
Article in Chinese | WPRIM | ID: wpr-775347

ABSTRACT

A method, for determination of saponins, amino acids and nucleosides in Panacis Japonici Rhizoma of ultra fast liquid chromatography with triple quadrupole linear ion trap mass spectrometry (UFLC-QTRAP-MS/MS), was established to investigate the effect of different processing methods on the target components of Panacis Japonici Rhizoma. The chromatographic separation was performed on a XBridgeC₁₈(4.6 mm×100 mm, 3.5 μm) at 30 °C with a gradient elution of 0.1% formic acid solution-0.1% formic acid acetonitrile, and the flow rate was 0.8 mL·min⁻¹, using multiple-reaction monitoring (MRM) mode. The grey relational analysis was adopted for the analysis of different processing samples. The results showed that the thirty-three constituents were in a good linear range and the correlation coefficient was greater than 0.999 0; the precision, repeatability and stability were good; the average recovery rates were between 95.33% and 101.8%, and the relative standard deviations were less than 5%. The result of grey relational analysis showed that the complete rhizomes without peeling, which were adopted for the microwave dried method, had the best quality. The established method was accurate and reliable, which could be used to appraise the quality of Panacis Japonici Rhizoma. Our study may lay the way for the processing method of Panacis Japonici Rhizoma in optimization,normalization and standardization.


Subject(s)
Amino Acids , Chromatography, High Pressure Liquid , Chromatography, Liquid , Nucleosides , Panax , Chemistry , Phytochemicals , Rhizome , Chemistry , Saponins , Tandem Mass Spectrometry
8.
Braz. j. med. biol. res ; 50(3): e5796, 2017. tab
Article in English | LILACS | ID: biblio-839267

ABSTRACT

We aimed to investigate the influence of regulatory T cells including CD4+CD25+, CD8+CD28- and hepatitis B virus (HBV) genotype on sustained virological response and tolerance of nucleoside drugs. One hundred and thirty-seven patients were enrolled. Lamivudine was administered to 84 patients. Entecavir was administered to the other 53 patients. Before treatment, biochemical tests, HBV DNA load, HBV serum level, HBV genotype, PB CD3+, CD4+, CD8+, CD4+CD25+/CD3+, and CD8+CD28-/CD3+ frequencies were measured. Based on HBV DNA loads after 4 weeks of therapy, patients were divided into response group and suboptimal response group. The lamivudine group received treatment continuously, and then patients were categorized into non-resistance group and resistance group. Compared with the suboptimal response and resistance groups for lamivudine, CD4+CD25+/CD3+ levels were higher in the response and non-resistance groups (t=4.372, P=0.046; t=7.262, P=0.017). In the non-resistance group, CD8+CD28-/CD3+ frequency was lower than in the resistance group (t=5.527, P=0.037). Virus load and hepatitis B E antigen (HBeAg)-positive rate were significantly lower than in the response and resistance group (t=2.164, P=0.038; X2=4.239, P=0.040; t=2.015, P=0.044; X2=16.2, P=0.000). Incidence of drug resistance was high in patients with virogene type C. For the virological response to entecavir, CD8+CD28-/CD3+ level was significantly lower than that of the suboptimal response group (t=6.283, P=0.036). Response and suboptimal response groups were compared in CD3+, CD4+, CD8+, CD4+CD25+/CD3+ and virus genotype, and differences were not statistically significant (P>0.05). Baseline regulatory T cells including CD4+CD25+/CD3+ and CD8+CD28-/CD3+ frequencies have a relationship with the incidence of rapid virological response and the resistance to nucleoside drugs. Patients with HBV genotype C receiving lamivudine more often underwent drug resistance. Antiviral efficacy and the resistance to lamivudine were closely correlated with baseline factors; the same cannot be found for entecavir.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Antiviral Agents/therapeutic use , Guanine/analogs & derivatives , Hepatitis B virus/immunology , Hepatitis B, Chronic/drug therapy , Lamivudine/therapeutic use , Nucleosides/therapeutic use , T-Lymphocytes, Regulatory , Drug Resistance , Genotype , Guanine/therapeutic use , Hepatitis B virus/drug effects , Hepatitis B, Chronic/virology , Sustained Virologic Response , T-Lymphocytes, Regulatory/immunology , Time Factors
9.
Chinese Journal of Hepatology ; (12): 143-146, 2016.
Article in Chinese | WPRIM | ID: wpr-314646

ABSTRACT

A high maternal viral load is the most important factor affecting immunoprophylaxis against mother-infant transmission of HBV. The application of antiviral drugs in pregnant women with a high serum HBV DNA level (>10(6)~10(7) IU/ml) during the second and third trimesters can reduce the prenatal serum HBV DNA level and significantly increase the success rate of blocking mother-infant transmission in neonates. This article interprets the contents related to antiviral therapy for pregnant women carrying HBV with the purpose of blocking mother-infant transmission of HBV in the guidelines published by Asian Pacific Association for the Study of the Liver, European Association for the Study of the Liver, National Institute for Health and Care Excellence, Korean Association for the Study of the Liver, and World Health Organization.


Subject(s)
Antiviral Agents , Therapeutic Uses , DNA, Viral , Blood , Female , Hepatitis B , Drug Therapy , Humans , Infant, Newborn , Infectious Disease Transmission, Vertical , Nucleosides , Therapeutic Uses , Nucleotides , Therapeutic Uses , Practice Guidelines as Topic , Pregnancy , Pregnancy Complications, Infectious , Virology , Viral Load
10.
Article in Chinese | WPRIM | ID: wpr-284805

ABSTRACT

The concentration of 5 nucleosides, uracil, uridine, guanidine, adenine and adenosine in culture of Paecilomyces hepialid was determined by the developed method of HPLC. The HPLC method was performed on a Waters SunFire C18 (4.6 mm x 250 mm, 5 μm) column with methanol-water gradient elution as the mobile phase. The detection wavelength was 260 nm and the colunmn temperature was controlled at 30 °C. The linear range was 10.00-200.00 mg · L(-1) (r = 0.9994) for uracil, 10.10-202.00 mg · L(-1) (r = 0.9992) for uridine, 10.00-200.00 mg · L(-1) (r = 0.9991) for guanidine, 10.30-206.00 mg · L(-1) (r = 0.9992) for adenine and 10.45-209.00 mg · L(-1) (r = 0.9991) for adenosine, respectively. The RSD of precision was 0.032%, 0.035%, 0.039%, 0.049%, 0.00080%, respectively. The average recoveries of uracil, guanidine, adenine, and adenosine were 97.34%, 99.10%, 101.6%, 98.61% and 100.2% with RSD of 1.3%, 2.1%, 0.96%, 0.95%, and 1.3% respectively. The method showed high sensitivity, good selectivity, linearity and repeatability, which was suitable for the content analysis of 5 nucleosides components in P. hepialid and its extracts.


Subject(s)
Chromatography, High Pressure Liquid , Methods , Nucleosides , Paecilomyces , Chemistry
11.
Article in Korean | WPRIM | ID: wpr-208447

ABSTRACT

BACKGROUND/AIMS: Tenofovir disoproxil fumarate (TDF) plays a pivotal role in the management of drug-resistant chronic hepatitis B. However, it remains unclear whether TDF-nucleoside analogue combination therapy provides better outcomes than TDF monotherapy. This study aimed to compare the efficacy of TDF monotherapy with that of TDF-nucleoside analogue combination therapy in patients with drug-resistant chronic hepatitis B. METHODS: This retrospective cohort study included 76 patients receiving TDF-based rescue therapy for more than 12 months. Suboptimal response was defined as serum HBV-DNA level of >60 IU/mL during prior rescue therapy. Multi-drug resistance was defined as the presence of two or more drug resistance-related mutations confirmed by mutation detection assay. The relationship between baseline characteristics and virologic response (HBV DNA <20 IU/mL) at 12 months were evaluated using logistic regression analysis. RESULTS: Fifty-five patients (72.4%) were suboptimal responders to prior rescue therapy, and 26 (34.2%) had multi-drug resistance. Forty-two patients (55.3%) received combination therapy with nucleoside analogues. Virologic response at 12 months was not significantly different between the TDF monotherapy group and TDF-nucleoside analogue combination therapy group (p=0.098). The serum HBV DNA level was reduced to -4.49+/-1.67 log10 IU/mL in the TDF monotherapy group and to -3.97+/-1.69 log10 IU/mL in the TDF-nucleoside analogue combination therapy group at 12 months (p=0.18). In multivariate analysis, female sex (p=0.032), low baseline HBV-DNA level (p=0.013), and TDF monotherapy (p=0.046) were predictive factors for virologic response at 12 months. CONCLUSIONS: TDF monotherapy showed similar efficacy to that of TDF-nucleoside analogue combination therapy in patients with drug-resistant chronic hepatitis B.


Subject(s)
Adult , Aged , Antiviral Agents/pharmacology , Cohort Studies , DNA, Viral/blood , Drug Resistance, Viral , Drug Therapy, Combination , Female , Hepatitis B virus/drug effects , Hepatitis B, Chronic/drug therapy , Humans , Logistic Models , Male , Middle Aged , Multivariate Analysis , Nucleosides/chemistry , Retrospective Studies , Sex Factors , Tenofovir/therapeutic use , Treatment Outcome , Young Adult
12.
Chinese Journal of Hepatology ; (12): 826-831, 2015.
Article in Chinese | WPRIM | ID: wpr-303223

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the efficacy and related factors of pegylated-interferon alpha-2a (PEG-IFN-2a) treatment in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) who achieved partial viral response with nucleoside analogue (NA) therapy.</p><p><b>METHODS</b>Patients with HBeAg-positive CHB and partial viral response to NA treatment were administered a PEG-IFN-2a therapy regimen of 180 g subcutaneous injection once weekly for a personlized duration of time. The existing NA therapy was continued in combination with the new PEG-IFN-2a treatment for 12 weeks. Measurements of serum HBV DNA load, hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), HBeAg and hepatitis B e antibody (anti-HBe) were taken at baseline (prior to addition of the PEG-IFN-2a therapy) and every 3 months afterwards.For determining response to treatment, primary efficacy was defined as undetectable HBsAg and seroconversion, and secondary efficacy was defined as HBsAg less than 10 IU/mL and HBeAg seroconversion.Statistical analysis was carried out using SPSS statistical software.</p><p><b>RESULTS</b>A total of 81 consecutive patients with an average of 12.0 months (range: 6.0-24.0 months) of NA therapy were included in the study and received an average of 19.6 months (range: 15.5-33.3 months) of PEG-IFN-2a treatment. At the end of PEG-IFN-2a therapy, 7 (8.6%) of the patients achieved undetectable HBsAg and seroconversion, and 14 (17.3%) showed HBsAg less than 10IU/mL. In addition, 40.7% achieved undetectable HBeAg and seroconversion, a rate that was slightly higher than that (38.3%) seen in treatment-naive patients who received PEG-IFN-2a. Statistical analyses suggest that baseline level of HBsAg at less than 1500 IU/mL may predict end of PEG-IFN-2a treatment response for HBsAg less than 10 IU/mL, as evidenced by the area under the curve measure of 0.747, sensitivity measure of 87.3%, specificity measure of 33.3%, positive predictive value of 82.1% and negative predictive value of 42.8%.</p><p><b>CONCLUSION</b>Patients with HBeAg-positive CHB and partial viral response to NA therapy can achieve undetectable HBsAg and HBeAg seroconversion after switching to PEG-IFN-2a treatment. Baseline HBsAg level may be predictive of response to this therapeutic strategy.</p>


Subject(s)
Antiviral Agents , Therapeutic Uses , DNA, Viral , Blood , Hepatitis B Antibodies , Blood , Hepatitis B Surface Antigens , Blood , Hepatitis B e Antigens , Blood , Hepatitis B, Chronic , Drug Therapy , Humans , Interferon-alpha , Therapeutic Uses , Nucleosides , Therapeutic Uses , Polyethylene Glycols , Therapeutic Uses , Recombinant Proteins , Therapeutic Uses , Sensitivity and Specificity , Treatment Outcome , Viral Load
13.
Article in English | WPRIM | ID: wpr-32659

ABSTRACT

In a continuation of our studies to discover bioactive secondary metabolites from marine sources, we further investigated samples from a tryptamine and phenyl-alkane producing sponge, which resulted in the isolation of four uncommon small molecules and five nucleosides. Their structures were determined to be 7,8-dihydroimidazo[1,5-c]pyrimidin-5(6H)-one (1), 5-chlorocavernicolin (2), maleimide-5-oxime (3), 3-methylmaleimide-5-oxime (4), uridine (5), 2'-deoxyuridine (6), thymidine (7), adenine (8), and adenosine (9) by spectroscopic analyses. The isolated compounds were evaluated for inhibitory activity against soluble epoxide hydrolase (sEH) as well as the Wnt/beta-catenine signaling pathway.


Subject(s)
Adenine , Adenosine , Nucleosides , Oximes , Porifera , Thymidine , Uridine
15.
Mycobiology ; : 353-360, 2014.
Article in English | WPRIM | ID: wpr-729768

ABSTRACT

Makgeolli is a traditional Korean alcoholic beverage. The flavor of makgeolli is primarily determined by metabolic products such as free sugars, amino acids, organic acids, and aromatic compounds, which are produced during the fermentation of raw materials by molds and yeasts present in nuruk, a Korean fermentation starter. In this study, makgeolli was brewed using the wild yeast strain Saccharomyces cerevisiae Y98-5, and temporal changes in the metabolites during fermentation were analyzed by ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry. The resultant data were analyzed by partial least squares-discriminant analysis (PLS-DA). Various metabolites, including amino acids, organic acids, sugar alcohols, small peptides, and nucleosides, were obviously altered by increasing the fermentation period. Changes in these metabolites allowed us to distinguish among makgeolli samples with different fermentation periods (1, 2, 3, 6, 7, and 8 days) on a PLS-DA score plot. In the makgeolli brewed in this study, the amounts of tyrosine (463.13 microg/mL) and leucine (362.77 microg/mL) were high. Therefore, our results indicate that monitoring the changes in metabolites during makgeolli fermentation might be important for brewing makgeolli with good nutritional quality.


Subject(s)
Alcoholic Beverages , Amino Acids , Amino Sugars , Fermentation , Fungi , Leucine , Mass Spectrometry , Nucleosides , Nutritive Value , Peptides , Saccharomyces cerevisiae , Sugar Acids , Tyrosine , Yeasts
16.
São Paulo; s.n; s.n; 2014. 149 p. tab, graf, ilus.
Thesis in Portuguese | LILACS | ID: biblio-847664

ABSTRACT

Neste trabalho, 2 diferentes procedimentosforam utilizados para a extração de lignina a partir do licor negro, caracterizando-se quimicamente as amostras de lignina obtidas em relação a umalignina comercial, visando a aplicação no desenvolvimento de sensores voltamétricos. A análise elementar, espectroscopia na região do infravermelho, análise térmica e caracterização eletroquímica do material mostraram que, tanto a origem da lignina quanto a metodologia de obtenção da mesma, a partir do licor negro, podem fornecer materiais com propriedades químicas distintas, embora possuam comportamento eletroquímico similar. Observou-se, também, que a lignina só pode ser armazenada na forma sólida,devido à oxidação pelo oxigênio dissolvidodurante o tempo em que a solução mãe é armazenada.No entanto, a oxidação dalignina é necessária quando se tem por objetivo o desenvolvimento de sensores voltamétricos, devido a predominância de carbonos sp2na estrutura químicaoxidada, condição em que se obtém maior condutividade. Constatou-se também a necessidade de utilizar um transdutor metálico para o desenvolvimento de eletrodos qumicamente modificados com este material, visto que os eletrodos de carbono modificados com lignina oxidada ou não oxidada não apresentaram atividade eletroquímica. Devido à pequena porcentagem de enxofre existente na estrutura química, a lignina oxidada tende a se organizar pelos grupamentos SH quando na presença de ouro, expondo os grupamentos quinônicos eletroativos. A lignina oxidada ainda foi utilizada no preparo de eletrodo de pasta de carbono com nanopartículas de ouro, na qual a lignina oxidada impregnada no grafite atua como redutor "in-situ" do ouro, permitindo o preparo de um sensor voltamétrico versátil, capaz de realizar a determinação de ácido ascórbico, dopamina, nitrito e iodato. No que tange ao comportamento eletroquímico de fármacos e estudos de interação fármaco-DNA, eletrodos de carbono foram modificados com DNAdupla fita com a finalidade de monitorar a interação DNA-Gemcitabina.O fármaco não apresentou atividade eletroquímica tanto na região positiva quanto na região negativa de potencial. A interação do mesmo com o DNA promove a condensação/agregação das duplas fitas do DNA em uma primeiraetapa, seguida da clivagem do nucleosídeo guanosina, formando guanina livre. O comportamento eletroquímico de leflunomida e sulfasalazina, dois fármacos aplicados ao tratamento da artrite reumatóide, foi estudado e mecanismos de oxidação foram propostos para cada fármaco


The chemical properties of samples of lignin, which were precipitated from black liquor using two different methodologies (precipitation with CO2 and H2SO4), were studied and the results compared to those obtained from a commercial lignin sample in order to prepare voltammetric sensors. The elementary analysis, infrared spectroscopy, thermal analysis and electrochemical characterization of the material demonstrated that both, the source of lignin and the precipitation method from the black liquor, can provide lignin samples with different chemical properties, although the electrochemical behavior of all samples has been the same. Lignin could only be stored in solid form as lignin in the black liquor is slowly and quantitatively oxidized by dissolved oxygen, preventing the extraction procedures. However, the lignin as extracted from black liquor cannot be used to modify solid electrodes due its high resistivity. The previous oxidation of the all material was necessary when the aim was its application on the sensors development. The electrical conductivity in the oxidized lignin was achieved, probably due to the predominance of sp2 hybridized carbon atoms, which improved orbital overlapping in the material. In addition, it was necessary to use a metallic transducer to produce electrodes modified with films of lignin with good electrochemical activity. The films drying time was also important parameter, which suggested a specific organization of lignin macromolecules over the electrode surface. Due to the small percentage of sulfur in the material, the oxidized lignin tended to be organized by the SH groups in the presence of metallic substrates, exposing its electroactive quinone groups. The oxidized lignin was further used to prepare carbon paste electrodes modified with gold nanoparticles, in which the impregnated oxidized lignin on graphite acted as an "in situ" reducing agent towards HAuCl4.The resulting composite allowed the preparation of a versatile voltammetric sensor, capable of detecting ascorbic acid, dopamine, nitrite and iodate. Regarding the electrochemical behavior and drug interaction studies DNA-molecule, carbon electrodes were modified with double strand DNA with the purpose of monitoring Gemcitabine-DNA interaction. The drug showed no electrochemical activity both, in the positive and the negative potential. The Gemcitabine-DNA interaction promoted condensation / aggregation of the double strand DNA in a first step, followed by cleavage of the nucleoside guanosine in the form of free guanine. In addition, the electrochemical behavior of sulfasalazine and leflunomide, two pharmacological compounds applied to the treatment of rheumathoid arthritis, were studied and their oxidation mechanisms were proposed


Subject(s)
DNA , Lignin/analysis , DNA Cleavage , Nucleosides , Sulfasalazine/administration & dosage
17.
Chinese Journal of Hepatology ; (12): 884-890, 2014.
Article in Chinese | WPRIM | ID: wpr-337044

ABSTRACT

Nucleoside and nucleotide analogs (NAs) have been successfully used for treatment of chronic hepatitis B. Hepatitis B virus (HBV) replication is now recognized as the key driver of liver injury and disease progression, so the primary aim of treatment for chronic HBV infection is to maximize sustained suppression of HBV replication to undetectable levels. The long-term treatment has also been shown to achieve substantial histological improvement and regression of liver fibrosis or cirrhosis, and reduction of hepatocellular carcinoma. This paper has reviewed the necessity, clinical benefits, and the management of long-term treatment for chronic hepatitis B.


Subject(s)
Antiviral Agents , Carcinoma, Hepatocellular , Hepatitis B virus , Hepatitis B, Chronic , Humans , Liver Cirrhosis , Nucleosides , Virus Replication
18.
Article in Chinese | WPRIM | ID: wpr-310986

ABSTRACT

This study aims to establish an HPLC method for simultaneous determination of gastrodin and eight nucleosides and nucleobases components in Gastrodia elata. The separation was carried out on an Agilent Zorbax Bonus-RP (4.6 mm x 250 mm, 5 μm) column with a methanol-(0.04% acetic acid) water solution gradient elution program at a flow rate of 1.0 mL x min(-1). The column temperature was 36 degrees C, and the detection wavelength was 254 nm. The volume of injection was 20 μL. The nine components including gastrodin, cytosine, uracil, cytosine, adenine, thymine, uridine, guanosine and adenosine were well separated. The calibration curve was well linear in the range of 2.04-262.00 mg x L(-1), 0.20-24.67 mg x L(-1), 0.18-23.75 mg x L(-1), 0.20-25.83 mg x L(-1), 0.20-26.67 mg x L(-1), 0.16-20.00 mg x L(-1), 0.22-27.71 mg x L(-1), 0.20-24.29 mg x L(-1), 0.24-30.58 mg x L(-1), respectively, and the correlation coefficient was between 0.998 9-0.999 9. The average recovery of gastrodin and eight nucleosides and nucleobases were 96.4%-99.6%, RSD less than 2.7% (n = 6). The contents of gastrodin in all the seven Tibet cultured Gastrodia elata samples were over 2 mg x g(-1). Further, all samples contain higher contents of adenosine, guanosine, uridine and cytidine compared to low contents of cytosine, uracil, adenine and thymine. The established method is accurate, reproducible and suitable for the determination of gastrodin and eight nucleosides and nucleobases comppnents in Gastrodia elata.


Subject(s)
Benzyl Alcohols , Chromatography, High Pressure Liquid , Methods , Drugs, Chinese Herbal , Gastrodia , Chemistry , Glucosides , Nucleosides , Nucleotides
19.
JPMI-Journal of Postgraduate Medical Institute. 2013; 27 (1): 38-41
in English | IMEMR | ID: emr-130425

ABSTRACT

To study the effect of Telbuvidine [LDT] mono therapy in the treatment of HBeAg positive Chronic Hepatitis B infection [CHB] with normal ALT levels. Ninety HBe antigen [HBeAg] positive CHB infection patients were enrolled and followed between June 2008 and June 2011. All of them had ALT levels less than twice the upper normal limit [Mean 36.9 SD 19.9]. All patients were HBeAg positive, had serum DNA level >10[4] copies/ml and never had previously received anti HBV treatment. All patients were given LDT 600mg daily as initial antiviral treatment for two years. Out of 83 patients who continued the treatment as per protocol, 59 were males and 24 were females between ages of 21 and 50 years. Baseline HBV DNA levels were 7.82x10[7] copies/ml [Range 4.8x10[4]-8.3x10[9] copies/ml]. By the end of first year [52 weeks] the mean decrease in serum HBV DNA levels was 7.88 log[10] copies/ml and the proportion of patients having undetectable HBV DNA levels was 73%. At the end of second year of therapy [96 weeks] the percentage of undetectable HBV DNA levels increased to 86%. At the end of 1[st] [52 weeks] and 2[nd] [96 weeks] HBeAg seroconversion rates were 62% and 86% while HBsAg seroconversion was 8% and 13% respectively. LDT is a reasonable cost effective therapy for HBeAg reactive CHB patients with normal baseline ALT levels resulting in a significant serological and virological response and was well tolerated in our population of Khyber Pukhtunkhwa


Subject(s)
Humans , Female , Male , Nucleosides/agonists , Hepatitis B e Antigens , Prospective Studies , Chronic Disease , Treatment Outcome
20.
Chinese Journal of Hepatology ; (12): 825-828, 2013.
Article in Chinese | WPRIM | ID: wpr-277989

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the clinical characteristics of and factors related to relapse in chronic hepatitis B (CHB) patients who had previously achieved cessation criteria and had been withdrawn from nucleoside analogues treatment.</p><p><b>METHODS</b>Sixty CHB patients who experienced relapse after nucleoside analogues withdrawal based on cessation criteria were enrolled in the study retrospectively. Each patient's data on biochemical, serological and viral characteristics corresponding to baseline (treatment initiation), withdrawal and relapse were collected. COX proportional hazard modeling was used to evaluate the factors related to relapse.</p><p><b>RESULTS</b>The hepatitis B e antigen (HBeAg)-positive and -negative patients had similar median antiviral treatment times (38 months (range: 24 - 80) vs. 35 months (30 - 60); Z = -1.313, P more than 0.05). For all patients, the median follow-up time was 12 months (2 - 72), during which 49 (81.7%) patients developed virological breakthrough and 17 (28.3%) developed HBeAg recurrence. The patients who experienced virological breakthrough or HBeAg recurrence had significantly higher baseline levels of HBV DNA than those patients who remained disease-free (t = 2.15 and -2.54 respectively; P less than 0.05). The median relapse time of the HBeAg-positive patients was significantly longer than that of the HBeAg-negative patients (14 months (3 - 72) vs. 6 months (3 - 36); Chi-square test = 7.045, P less than 0.01). HBeAg status at baseline was identified as an independent factor associated with relapse (relative risk = 1.937, 95% confidence interval = 1.14-3.28, P less than 0.05).</p><p><b>CONCLUSION</b>HBeAg-positive and-negative patients showed distinct clinical characteristics of relapse, with the latter being more prone to relapse soon after nucleoside analogues withdrawal. Prolonging the treatment course may be beneficial to HBeAg-negative patients, even if cessation criteria are achieved.</p>


Subject(s)
Adult , Antiviral Agents , Therapeutic Uses , DNA, Viral , Blood , Female , Hepatitis B e Antigens , Blood , Hepatitis B, Chronic , Drug Therapy , Humans , Male , Middle Aged , Nucleosides , Therapeutic Uses , Recurrence , Retrospective Studies , Treatment Outcome
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