Nucleoside Research Articles

Application value of urine modified nucleoside's detection in prognosis of bladder transitional cell carcinoma

Objective To study the application value of modified urine nucleoside's detection in prognosis of patients with bladder cancer. Methods We enrolled 85 patients with bladder transitional cell carcinoma confirmed by pathological examination.The 85 patients fulfilled one-year follow-up visit after TUR-BT and were reviewed every three months.The 85 patients did not relapse in the first third month after operation.At the sixth month after operation,20 cases relapsed.18 cases and 19 cases relapsed at the ninth month and the twelfth month after operation.Patients with recurrence added up to 57 cases as the recurrent group.The remaining 28 cases did not relapse at one year after operation as the no recurrent group.Of the 85 cases,55 cases were in T(is) - T1,while 30 cases were in T2 - T4.Of the 85 cases,27 cases were with G1,40 cases were with G2 and 18 cases were with G3.In T(is) -T1,there were 35 cases in recurrent group,while there were 20 cases in the no recurrent group.In T2 -T4,there were 22 cases in recurrent group,while there were 8 cases in the no recurrent group.There were 50 normal people in the control group.Highperformance liquid chromatography/electrospray ionization-quadrupole-time-of-flight mass spectromerry was used to measure the levels of change of two urine modified nucleosides (M1A,1-MeI) which the patients with bladder cancer had different pathology grades,clinical stages,before or after operation and recurrence or no recurrence. Results The levels at third month after operation in no recurrent group ( M1A:3.24 ± 0.40,1 -MeI:5.73 ± 0.67 ) were significantly lower than that before operation ( M 1A:4.34 ± 0.98,1-MeI:14.22 ± 4.05,P ＜ 0.005 ),and remained in low status at another time points after operation.The levels at the third month after operation in recurrent group (M1A:3.31 ±0.33,1-MeI:5.67 ±0.55) were significantly lower than that before operation ( M1A:4.32 ± 1.19,1-MeI:14.31 ± 4.12,P ＜ 0.005 ),which was on the rise and indicating a high level approaching the condition before operation.According to the time point before the operation,recurrent group and no recurrent group were higher than control group (M1A:2.91 ±0.84,1-MeI:5.56 ± 1.25,P ＜ 0.01 ).The levels at the sixth month,ninth month and twelfth month after operation in recurrent group ( M 1A referring to 4.04 ± 0.48,4.11 ± 0.47,4.09 ± 0.53 ;1-MeI referring to1 1.46 ± 1.34,12.14 ± 1.22,12.33 ± 1.27) were the highest (P ＜ 0.01 ).The levels of change of two urine modified nucleosides between pathology grade and clinical stage had no statistical difference ( P ＞ 0.01 ).The levels in recurrence group in T(is) - T1 ( M1 A:5.92 ± 1.28,1-MeI:20.01 ± 8.53 )were higher than the levels in no recurrent group ( M1A:4.02 ±1.22,1 -MeI:11.21 ± 6.45,P ＜ 0.05 ),which was the same in T2 - T4. Conclusion Urine modified nucleosides detection offer a certain clinical value the prognostic of operated bladder cancer patients. Key words: Bladder neoplasms; Carcinoma; Modified nucleoside; Prognosis

SPARTAN: Two-Drug, NRTI-Sparing Regimens Continue to Disappoint

Current guidelines recommend that initial HIV treatment contain at least three antiretrovirals, including a pair of nucleoside reverse transcriptase

The impact of antiviral therapy on virus-specific T-cell reactivity in patients with chronic hepatitis B

To investigated the impact of viral load decline on virus-specific T-cell reactivity on patients with chronic hepatitis B. 23 cases of patients with chronic hepatitis B were recruited randomized to therapy with nucleoside analogue or alpha interferon from January 2009 to April 2010. Peripheral blood mononuclear cells (PBMCs) were collected longitudinally at baseline and the time of HBV DNA undetected. T-cell reactivity to HBV core antigens were tested using Elispot assays and Luminex. (1) The frequency of T cell reactivity induced by HBcAg in patients with chronic hepatitis B were 91.3% at the time of HBV DNA undetected, which significantly higher than The frequency of 69.6% at baseline. The frequency between nucleoside analogue treatment group and alpha interferon treatment group was no significant difference. (2) The average response magnitude was expressed as spot forming unit (SFU) per million input cells. SFU of T cell responses to HBcAg was 120 SFU/10(6) PBMCs at baseline, much lower than SFU of 1060 SFU/10(6) PBMCs at the time of HBV DNA undetected. No significant difference between patients with negative T cell reactivity at baseline and patients with positive T cell reactivity at baseline was found. In patients with initial virological response (IVR) to therapy and patients with early virological response (EVR), no significant difference was found in the magnitude at baseline as well as at the time of HBV DNA undetected. (3) The average response magnitude of nucleoside analogue treatment group was 1713 SFU/10(6) PBMCs at the time the time of HBV DNA undetected, higher than 189 SFU/10(6) PBMCs at baseline. But in interferon treatment group, the average response magnitude was no significant difference, 120 SFU/10(6) PBMCs at the baseline and 305 SFU/10(6) PBMCs at the time the time of HBV DNA undetected respectively. The average response magnitude in nucleoside analogue treatment group was greater than that in interferon treatment group. (4) As to compare difference of IFN-γ concentration in supernatant of T cell culture solution stimulated by HBcAg, IFN-γ secreted by T cell at the time of HBV DNA undetected was clearly higher than IFN-γ secreted at baseline, (38 ± 9) ng/L and (90 ± 9) ng/L respectively. Antiviral therapy made profit to improve virus-specific T-cell reactivity in patients with chronic hepatitis B, suggesting the importance to investigate HBV specific T cell responses.

Study on HIV-1 drug resistance profile of 257 AIDS patients with failure on the first-line antiretroviral treatment in Henan

To understand the current situation related to genotypic resistance in patients receiving the first-line antiretroviral treatment, but with with virologic failure, in Henan province and to compare the patterns of drug resistance in patients from different areas. 276 patients with virologic failure on first-line antiretroviral treatment were selected in three different areas of Henan, in 2010. CD4(+)T cells, virus load and genotypic resistance were measured and tested. Prevalence and mutations related to drug-resistant were analyzed. The overall prevalence of drug-resistance was 68.48% in 257 patients, with non-nucleoside reverse transcriptase inhibitor (NNRTIs) as 67.70%. Rate of nucleoside reverse transcriptase inhibitor (NRTIs) was 54.09%, and protease inhibitors (PIs) was 1.18%. The prevalence rates of drug-resistance in A, B and C groups were 82.35%, 97.47% and 52.80%, respectively, and withs significant differences (χ2=50.624, P=0.000). The Prevalence rates related to resistance of NNRTIs and NRTIs were also significantly different (χ2=48.771, P=0.000 and χ2=33.912, P=0.000). 26.46% of the samples had M184V/I mutation which was the highest NRTIs mutation among the 257 patients. The prevalence rates on resistance of A and B were 47.06% and 49.37%, higher than that of C (13.04%, χ2=39.905, P=0.000) followed by TAMs, TAMs-1 and TAMs-2 which were 8.56% and 4.28%. C had the lower prevalence of TAMs-1 than A and B (χ2=13.499, P=0.001). 40.47% of the samples harbored≥1 TAM, with T215Y/F having the most, as 33.85%. 31.13% of 257 patients appeared most NNRTIs mutation K103N in this study, with the prevalence rates also significant different (χ2=14.213, P=0.001) in the three areas. Two PIs mutations were detected in 257 patients: M46I/L, (1.17%) and V82F (0.39%). However, none was detected in area A. Different patterns of drug resistance were found in different areas of Henan province and should be treated differently. The work related to AIDS second-line antiretroviral therapy in Henan should be more opportune, rigorous and standardized.

Clinical analysis of HBsAg clearance in ten chronic hepatitis B patients treated with nucleoside analogs

本研究对10例用核苷(酸)类似物(NUCs)治疗出现HBsAg阴转或血清学转换的病例资料进行了回顾性分析,现报道如下.一、资料与方法1.病例资料:收集2005年2月至2010年8月于沈阳市第六人民医院入院的10例慢性乙型肝炎(CHB)患者应用NUCs治疗出现HBsAg阴转或血清学转换的患者资料.临床诊断符合2005年慢性乙型肝炎防治指南[11标准. 关键词：肝炎;乙型;慢性;核苷(酸)类似物;治疗;抗病毒

Fluorescence and Electrochemical Recognition of Nucleosides and DNA by A Novel Luminescent Bioprobe Eu(lll) -TNB

The luminescence arising from lanthanide cations offers several advantages over organic fluorescent molecules: sharp, distinctive emission bands allow for easy resolution between multiple lanthanide signals; long emission lifetimes (μs -ms) make them excellent candidates for time-resolved measurements; and high resistance to photo bleaching allow for long or repeated experiments. A method is presented for determination of nucleosides using the effect of enhancement of fluorescence of the easily accessible europium(III)-TNB in presence of different nucleosides. The latter coordinates to Eu(III) -TNB and enhances its luminescence intensity as a result of the displacement of water from the inner coordination sphere of the central metal. A similar method for the determination of DNA based on the quenching of Eu(III)-TNB has been established. The interaction of Eu(III)-4,4,4 trifluoro-1-(2-naphthyl)1,3-butanedione (TNB) complex with nucleosides (NS) (guanosine, adenosine, cytidine, inosine) and DNA has been studied using normal and time-resolved luminescence techniques. Binding constants were determined at 293 K, 298 K, 303 K, 308 K and 313 K by using Benesi-Hildebrand equation. A thermodynamic analysis showed that the reaction is spontaneous with ΔG being negative. The enthalpy ΔH and the entropy ΔS of reactions were all determined. The formation of binary and ternary complexes of Eu(III) with nucleosides and TNB has been studied potentiometrically at (25.0 ± 0.1) °C and ionic strength I = 0.1 mol.dm(-3) (KNO3) . The formation of the 1:1 binary and 1:1:1 ternary complexes are inferred from the corresponding titration curves. Initial estimates of the formation constants of the resulting species and the protonation constants of the different ligands used have been refined with the HYPERQUAD computer program. Electrochemical investigations for the systems under investigations have been carried out using cyclic voltammetry (CV), differential pulse polarography (DPP), and square wave voltammetry (SWV) on a glassy carbon electrode in I = 0.1 mol/L p-toluenesulfonate as supporting electrolyte.

Identification of diverse carbon utilization pathways in Shewanella oneidensis MR-1 via expression profiling.

To identify pathways of carbon utilization in the metal-reducing marine bacterium Shewanella oneidensis MR-1, we assayed the expression of cells grown with various carbon sources using a high-density oligonucleotide Affymetrix microarray. Our expression profiles reveal genes and regulatory mechanisms which govern the sensing, import, and utilization of the nucleoside inosine, the chitin monomer N-acetylglucosamine, and a casein-derived mixture of amino acids. Our analysis suggests a prominent role for the pentose-phosphate and Entner-Doudoroff pathways in energy metabolism, and regulatory coupling between carbon catabolism and electron acceptor pathways. In sum, these results indicate that S. oneidensis possesses a broader capacity for carbon utilization than previously reported, a view with implications for optimizing its role in microbial fuel cell and bioremediative applications.

HIV Metabolic Disease: The Mitochondria–Adipocyte Connection

HIV metabolic disease in lipodystropic patients includes changes in fat tissue that are associated with insulin resistance, hypertriglyceridemia, and increased cardiovascular risk. Nucleoside reverse transcriptase inhibitors (NRTIs) have been shown to contribute to lipodystrophy by inhibiting mitochondrial DNA replication and transcription in fat tissue and adipocytes. Novel data from two recent studies show that immune activation and protease inhibitors (PIs) can also affect mitochondrial function. In a cross-sectional study aimed at characterizing the effects of HIV infection and antiretroviral therapy (ART) in adipose tissue, muscle, and peripheral blood mononuclear cells (PBMCs), Morse and colleagues compared mitochondrial DNA (mtDNA) …

Liver histological changes in chronic hepatitis B patients with alanine aminotransferase lower than two times the upper limit of normal

Objective To assess the liver histopathological characteristics of chronic hepatitis B (CHB) patients with alanine aminotransferase(ALT)lower than 2 times the upper limit of normal (ULN) through liver biopsy, and try to provide subjective evidence for clinical anti-viral treatment.Methods From October 2005 to August 2010, patients accepted liver biopsy in department of infectious disease, Sichuan provincial people's hospital were enrolled. The criteria for liver biopsy was as follow, (1) HBsAg-positive for more than 6 months, (2) HBeAg-positive patients with HBV DNA ≥103 copies/ml or HBeAg-negative patients with HBV DNA≥ 104copies/ml, (3) ALT was lower than 2 times ULN for more than 6 months,and without any hepatic protectants, (4) never accepted any antiviral treatment before, including IFN or nucleoside analogues, (5) willing to accept liver biopsy. Before liver biopsy, routine blood test, prothrombin time, liver function test, hepatitis B antigen and antibody test, HBV DNA quantification were examined. The biopsy position was located under routine ultrasound, liver biopsy were performed to assess the grading of inflammation and necrosis and the degree of fibrosis. The correlation between all the factors and liver inflammation and fibrosis were analyzed. Results Totally 383 cases (240 males and 143 females) met the diagnostic criteria, aged from 16 to 59 years old and the mean age was 28.0 years old. Cases of liver inflammation in G0, G1, G2, G3andG4 grade was 2 cases (0.5％), 165 cases (43.1％), 191 cases (49.9％), 25 cases (6.5 ％ ) and 0 cases (0 ％ ) respectively, cases≥G2 grade accounted 56.4 ％ of total. Meanwhile,stage of fibrosis in S0, S1, S2, S3 and S4 was 103 cases (26.9％), 265 cases (69. 2％), 13 cases (3.4％), 2 cases (0.5％) and 0 cases (0％) respectively, percentage of liver fibrosis in S2stage and over was only 3.9％. The occurrence of serious liver inflammation was associated with age, ALT levels, HBV DNA levels and HBeAg status (P＜0.05). There was no obvious association between HBV DNA level and liver fibrosis (P＞0.05). Conclusions There were obvious liver inflammation and different degree of liver fibrosis in CHB patients with alanine aminotransferase(ALT)lower than 2 times ULN. The degree of liver injury assessed by liver biopsys is recommended as an evaluation for the necessary of anti-viral therapy. Key words: Hepatitis B, chronic; Alanine transaminase; Inflammation; Liver cirrhosis; Biopsy

Clinical study on viral hepatitis combined with aplastic anemia

To study the clinical features, outcomes and treatments of viral hepatitis combined with aplastic anemia. 25 cases diagnosed as viral hepatits combined with aplastic anemia in Beijing Ditan Hsopital between April 2004 and September 2009 were retrospectively analyzed. In this group of patients aplastic anemia was finally diagnosed by bone marrow aspiration. We collected clinical data of these patients, including a history of liver disease, drug allergies, hospital medication history, laboratory data, and then performed descriptive analysis. 25 patients with viral hepatitis were diagnosed as complicated with aplastic anemia by histopathological data. Among these patients, 17 were male and 8 were women. Viral hepatitis included: chronic hepatitis B (12 cases), chronic hepatitis C (4 cases), acute hepatits E (1 case), hepatitis caused by CMV infection (1 case), and unclassified hepatitis (7 cases). Among these patients, 7 were diagnosed as severe hepatits. Considering previous history, only 3 patients had history of short term interferon therapy before hospitalization, and the remaining patients did not use drug that affects blood system. Treatments were as followings: using colony stimulating factor in 6 patients, gamma globulin in 9 patients, glucocorticoids in 3 patients, erythropoietin in 1 patient, only oral drug to raise erythrocytes in 2 patients, red blood cells transfusion in 6 patients, platelets transfusion in 2 patients. As for clinical outcomes, 20 patients acquired improved condition and were dicharged, 3 patients were discharged voluntarily and 2 patients died of severe hepatits combined with other complications. Main treatments of viral hepatitis combined with aplastic anemia were to treat primary hepatopathy and nucleoside analogue-based antiviral therapy, to provide symptomatic and supportive treatment for blood diseases. Blood diseases would recover simultaneously while liver disease was improved, and the prognosis was good.

Synthesis of 4′-Ethynyl-2′-deoxy-4′-thioribonucleosides and Discovery of a Highly Potent and Less Toxic NRTI

The synthesis of 4'-ethynyl-2'-deoxy-4'-thioribonucleosides was carried out utilizing an electrophilic glycosidation in which 4-ethynyl-4-thiofuranoid glycal 16 served as a glycosyl donor. Electrophilic glycosidation between 16 and the silylated nucleobases (N4-acetylcytosine, N6-benzoyladenine and N2-acetyl-O6-diphenylcarbamoylguanine) was carried out in the presence of N-iodosuccinimide (NIS) leading to the exclusive formation of the desired β-anomers 29, 33 and 36. Anti-HIV studies demonstrated that these 4'-thio nucleosides were less cytotoxic to T-lymphocyte (i.e. MT-4 cells) than the corresponding 4'-ethynyl derivatives of 2'-deoxycytidine (44), 2'-deoxyadenosine (45) and 2'-deoxyguanosine (46). Comparison of the selectivity indices (SI) was made between 4'-thionucleosides (32, 41 and 43) and the corresponding 4'-oxygen analogues 44-46 by using the reported CC50 and EC50 values. In the case of cytosine and adenine nucleosides, comparable SI values were obtained: 32 (545) and 45 (458); 41 (>230) and 45 (1,630). In contrast, 4'-ethynyl-2'-deoxy-4'-thioguanosine 43 was found to possess a SI value of >18,200, which is twenty times better than that of 46 (933).

Association between the change regularity of peripheral blood mononuclear cell mitochondrial deoxyribonucleic acid content and human immunodeficiency virus-related lipodystrophy

To investigate the change regularity of peripheral blood mononuclear cell (PBMC) mtDNA (mitochondrial deoxyribonucleic acid) content and its association with HIV-LD (human immunodeficiency virus-related lipodystrophy) in HAART (highly active antiretroviral therapy). At baseline, Months 6 and 24 of therapy, the cryopreserved PBMC were collected from 33 patients on a regular follow-up at our clinic. Among them, 17 had HIV-LD. Then total DNA was extracted and mtDNA content quantified by real-time PCR (polymerase chain reaction). The HIV/AIDS patients had a lower content of PBMC mtDNA (2(-ΔΔCt)) than the healthy controls at baseline (9.578 vs 17.195, P < 0.01). The mtDNA content was lower in the HIV-LD group than that in the no LD (NLD) group at each time point of therapy (13.619 vs 5.775, 6.360 vs 1.387, 7.170 vs 1.266, all P < 0.05). In the HIV-LD group, the half- and 2-year PBMC mtDNA content was markedly lower than those at baseline (both P < 0.05). And the change of mtDNA content (within half a year) was earlier than the onset of clinical HIV-LD at one year later. In the NLD group, the PBMC mtDNA content have an insignificant change after therapy. The mtDNA content decreased significantly in stavudine (d4T)-containing regimen group after treatment (P < 0.01), but showed no significant change in zidovudine (AZT)-containing regimen group after therapy. The decreased content of PBMC mtDNA after HIV infection and during HAART therapy is associated with HIV-LD. Nucleoside reverse transcriptase inhibitor, especially d4T, plays an important role in the progression of HIV-LD.

Genotypic resistance mutations to antiretroviral drugs in newly confirmed human immunodeficiency virus infectors in Beijing

To examine the prevalence of drug resistance mutations among the treatment-naive HIV (human immunodeficiency virus) infectors living in Beijing so as to provide the basal information for clinical antiviral treatment. HIV pol genes from plasma samples of 150 treatment-naive HIV-infected patients were amplified, sequenced and phylogenetically analyzed. And the drug-resistance associated mutations in protease and reverse transcriptase regions were analyzed with Stanford University HIV Drug Resistance Database. A total of 111 pol gene sequences were obtained. The overall prevalence of drug resistance was 8.1% (9/111), corresponding to 3.6% (4/111) for protease inhibitors, 1.8% (2/111) for nucleoside reverse transcriptase inhibitors and 3.6% (4/111) for non-nucleoside reverse transcriptase inhibitors. No drug resistance mutation was identified in 17 intravenous drug users. The prevalence of drug resistance is relatively high in the newly confirmed HIV infectors in Beijing. Regular surveillance and monitoring of drug-resistant HIV should be implemented.

Nucleoside triphosphate diphosphohydrolases (NTPDase) inhibitory activity of some medicinal plants.

Nucleoside triphosphate diphosphohydrolasess (NTPDases, EC 3.6.1.5) are well characterized ectoenzymes which are involved in the hydrolysis of ATP and ADP resulting in the formation of nucleoside monophosphates and orthophosphate. By hydrolyzing circulating ATP to ADP to AMP, NTPDases play a crucial role in preventing the activation of platelets and their aggregation. NTPDase inhibitors therefore are currently target for various cardiovascular diseases and some types of cancer. In search for new enzyme inhibitors of therapeutic importance, the present study was conducted to find out the inhibitors of NTPDase from methanolic extracts of 50 medicinal plants used in folk medicine. Data shows that only 6 plants exhibited anti-NTPDase activity above 50% with crude enzyme preparation of chicken liver at 125 μg plant extract. These plants included, Cymbopogan jawarancusa, (51.16±4.81%), Asparagus officinalis (58.24±0.93%), Tribulus terrestris (50.84±6.19%), Rubia cordizolla (53.11±3.49%), Echimops echimatus (51.48±6.29%) Portulaca oleracea (52.79±0.10%). These studies are priliminary findings and further work is required to explore these plants using purified enzyme preparations. Keywords: Nucleoside triphosphate diphosphohydrolases, NTPDases, medicinal plants.

Synthesis of Modified Nucleosides

Synthesis of Modified Nucleosides

Do Nucleosides Improve Outcomes in Salvage HIV Treatment

Assembling a suppressive antiretroviral regimen for patients with multiclass drug resistance is challenging. Treatment guidelines suggest the use of

Investigation of nucleoside therapy in patients with chronic hepatitis B knowledge needs

Objective To improve the compliance of nucleoside drugs in patients with chronic hepatitis B drug compliance to achieve the maintenance of a stable condition. Methods From February to June 2010,hospitalized in our department using nucleoside therapy in patients with chronic hepatitis B conducted a questionnaire survey, including: general information, medical and medication needs guidance, psychological guidance and mission mode. Results 106 patients, 73% of patients on drug-related knowledge, high demand,27% of patients on the medication knowledge of the higher demand. Patients also understand the requirements of mission mode. Conclusions The use of nucleoside drugs to the drug treatment of chronic hepatitis B patients are very strong demand for knowledge, nurses can be carried out according to the needs of patients with targeted,a variety of health drug guide, guide to health content and form of medication real implementation into practice,help patients with chronic hepatitis B using nucleoside drugs to improve treatment compliance. Key words: Chronic hepatitis B; Nucleoside drugs; Knowledge needs; Compliance

Thymidine-Sparing Regimens and Lipodystrophy

Thymidine-analogue nucleoside reverse transcriptase inhibitors (NRTIs) are the biggest culprits when it comes to lipodystrophy induced by antiretroviral therapy. However, patients on various thymidine-sparing regimens can also develop the condition, with risks and patterns of illness that are quite unpredictable. Seeking to clarify this murky area, researchers conducted a substudy within ACTG 5202, a clinical trial in which antiretroviral-naive HIV-infected adults were randomized to one …

Interaction of Silver Nanoparticles with DNA Building Blocks

The interaction of DNA bases and corresponding nucleotides with silver nanoparticles (AgNPs) biofunctionalized by tryptophan, has been investigated by absorption spectroscopy and dynamic light scattering. Aggregation of AgNPs was observed in the presence of ATP and GTP, in contrast to nucleoside. This is due to change in pH of the medium in the presence of triphosphates. Aggregation due to ATP was found to be greater than that of GTP, which is due to the interaction between adeninium ion and tryptophanyl residue on the surface of nanoparticle. There is a direct relationship between ATP concentration and aggregation of AgNPs, which in future might assist in developing new protocols for sensing of adenine nucleotides.

Why We Do the Things We Do: ACTG 5202 and Our Choice of NRTIs

Initial antiretroviral therapy (ART) almost always consists of two nucleoside reverse transcriptase inhibitors (NRTIs) plus a third drug. For the NRTI backbone, current guidelines indicate a strong preference for tenofovir/FTC over abacavir/3TC, mainly because of virologic efficacy differences previously demonstrated in the ACTG 5202 study. In that 96-week trial, treatment-naive patients were stratified by viral load (< or ≥100,000 copies/mL) and randomized to receive either tenofovir/FTC or abacavir/3TC, each in combination with efavirenz or ritonavir-boosted atazanavir. Midway through the …