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Objective: The objective of this study was to analyze and compare the effects of different urate-lowering agents on testicular functions in men with gout in a clinical setting. Methods: In this prospective cohort study (Clinical Trial Registration Number: NCT04213534), a total of 49 male patients aged 18–45 years with gout were enrolled. They were divided into three groups and received treatment with either allopurinol, febuxostat or benzbromarone for a duration of 3 months. Semen parameters, reproductive hormones and biochemical assessments were evaluated at baseline, month 1, and month 3. Results: Overall, 40 individuals (81.6%) completed the follow-up visits. In allopurinol group, there were no significant differences in semen parameters from baseline to month 3. Most of sperm parameters in febuxostat group did not show notable changes, except for a decrease in sperm motility at month 3(33.6%, [22.9–54.3] vs 48.4%, [27.4–67.6], p = 0.033). However, the total motile sperm count did not differ significantly after febuxostat treatment. Surprisingly, administration of benzbromarone resulted in improved sperm concentration (37.19 M/mL, [29.6–69.92] vs 58.5 M/mL, [49.8–116.6], p = 0.001). There were no significant changes observed in sperm DNA integrity and reproductive hormones in the three groups from baseline to month 3. The incidence of adverse events did not differ significantly among the three groups as well. Conclusion: This study is the first to demonstrate that urate-lowering agents, allopurinol and febuxostat, do not have clinically relevant negative effects on sperm quality and reproductive hormones in men with gout, and benzbromarone presents improving sperm concentration. Results provide important preliminary guidance for the development of reproductive health management guidelines for patients RCID with gout. [ABSTRACT FROM AUTHOR]

Rationale: Gypenosides have been reported to produce neuroprotective effects and increase monoamine neurotransmitter levels in the brain. Objective: Considering that depression is involved in monoamine reduction, this study evaluated the antidepressant-like effects of gypenosides in mice exposed to chronic unpredictable mild stress (CUMS). Methods: The sucrose preference test and forced swimming test were performed after administration of gypenosides (at 25, 50, or 100 mg/kg) for 4 weeks. Hippocampal brain-derived neurotrophic factor (BDNF) and its downstream targets were analyzed by western blot. Additionally, hippocampal neuronal proliferation was measured by immunohistochemistry. Results: Four-week treatment with fluoxetine (20 mg/kg) and gypenosides (at either 50 or 100 mg/kg) increased sucrose preference and decreased the immobility time in mice exposed to CUMS. In addition, gypenosides (at either 50 or 100 mg/kg) also increased BDNF expression and neuronal proliferation in the hippocampus of CUMS animals. Further, we showed that treating CUMS mice with K252a, which is an inhibitor of the BDNF receptor TrkB, blocked the effects of gypenosides (100 mg/kg), including behavioral improvements, neuronal proliferation, and up-regulation of p-TrkB, p-ERK, and p-Akt proteins. Conclusions: This study demonstrates that gypenosides exhibit antidepressant-like effects in mice, which may be mediated by activation of the BDNF-ERK/Akt signaling pathway in the hippocampus. [ABSTRACT FROM AUTHOR]

The sulfur-containing reagents dithizone, 2,3-dimercapto-1-propanol, 2-thenoyltrifluoroacetone, 1,3,4-thiadiazole-2,5-dithiol, and 1-(2-thiazolylazo)-2-naphthol (TAN) were first examined with respect to their stabilizing effect on CdTe nanocrystals. The indicator TAN was found to best passivate the surface of CdTe NCs if added during synthesis of the NCs at 100 °C. These NCs (referred to as NC-1) have an emission that peaks at 430 nm, and a quantum yield (QY) of 25 %. If, however, TAN-capped particles are prepared in presence of an ionic liquid at room temperature, the QY of such nanocrystals (referred to as NC-2) is increased by 80 % and the emission peak is shifted to 460 nm. The NC-1 particles bind Ag(I), Pb(II), Hg(II), Fe(III), Cr(III), and Cu(II) in phosphate buffer of pH 6.5 while NC-2 particles bind Cu(II) only. Binding of metal ions is associated with a drop in fluorescence intensity. In case of NC-1, quenching is observed in the 23.3 nM to 23.3 μM Cu(II) concentration range with detection limit of 0.5 nM. In case of NC-2, quenching occurs in the 233 nM to 233 μM Cu(II) concentration range with detection limit of 5.0 nM. The method was applied to the determination of Cu(II) in spiked biosamples, and recoveries of Cu(II) (at a 233 nM level) in BSA and fetal bovine serum using NC-2 are 95 % and 92 %. This is better than the recoveries from the same media with NC-1 (70 % and 32 %). These findings demonstrate that the NC-2 material is superior in terms of selectivity and stability but inferior in terms of detection limit. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

This study is aimed at comparing the efficacy and safety of loxoprofen sodium hydrogel patch (LX-P) with loxoprofen sodium tablet (LX-T) in patients with knee osteoarthritis (OA). One hundred sixty-nine patients were enrolled in a randomized, controlled, double-blind, double-dummy, multicenter, non-inferiority trial of LX-P. Patients were randomly assigned to either LX-P or LX-T groups for a 4-week treatment. The primary efficacy endpoint was the proportion of patients with an overall improvement of ≥50 %, and the secondary efficacy endpoint was the proportion of patients with an improvement of ≥25 % from baseline in each of the seven main symptoms. The non-inferiority trial was based on a power of 80 % and significance level of 2.5 % with a non-inferiority margin of −10 %. In both intention-to-treat (ITT) and per-protocol (PP) analyses, LX-P was as effective as LX-T in regard to the primary endpoint. In the ITT analysis, the difference between the two groups was 12.6 % [95 % confidence interval, −1.7 to 26.9 %]. No significant differences were found between the two groups in any of the secondary efficacy outcomes. A lower incidence of adverse events was observed in LX-P group; however, the difference was not statistically significant. No serious adverse events were reported in the LX-P group, whereas one case was reported in LX-T group. Based on the present study, topical loxoprofen patch was non-inferior to oral loxoprofen in patients with knee osteoarthritis. [ABSTRACT FROM AUTHOR]

CdTe quantum dots capped with thioglycolic acid (TGA) display a strong turn-on fluorescence response if exposed to solutions of cysteine (Cys). In order to exploit this effect, a molecularly imprinted polymer (MIP) for Cys was covalently linked to the QDs via allyl mercaptan. The resulting nanomaterials (QDs, MIP-coated QDs, and nonimprint-coated QDs) were characterized by FTIR and scanning electron microscopy. The adsorption of Cys was studied in phosphate buffer (pH 7.4) with respect to equilibration times (5, 15, and 40 min, respectively), binding constants [2.98, 2.42, and 0.96 (×10 M)], and Langmuir isotherms (R = 0.9995, 0.9999, and 0.9983) in the Cys concentration range between 3.33 μM to 500 μM. The method has a detection limit of 0.85 μM (3σ, blank, for n = 10). The selectivity of the MIP-coated QDs for Cys over 19 other amino acids is similar to that of bare QDs, but MIP-QDs afford better recoveries of Cys from solutions also containing bovine serum albumin (90 %) and fetal bovine serum (97 %), respectively, when compared to the recoveries that are obtained with bare (non-imprinted) QDs (135 % and 120 %). This is probably due to the fact that the outer MIP shell largely reduces protein wrapping, dot aggregation, and matrix inclusion. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A total sample-preparation and analysis time of 50 min is required for the high-throughput method of hair analysis proposed in this paper. The method is applicable to analysis of drugs commonly used in Asia, and their metabolites-methamphetamine (MA), amphetamine (AMP), methylenedioxymethamphetamine (MDMA), methylenedioxyamphetamine (MDA), ketamine (K), norketamine (NK), dehydronorketamine (DHNK), 6-acetylmorphine (6-AM), morphine (MOR), and codeine (COD). Cut and weighed hair (10 mg) was incubated for 3 min with methanol-trifluoroacetic acid (TFA) during microwave-assisted extraction (MAE) at 700 W. The incubation solution was evaporated, the residue was reconstituted in deionized water-methanol, 99:1 ( v/ v), and 20 μL was injected on to a core-shell column (50 × 4.6 mm, 2.6 μm particle size) for liquid chromatographic-tandem mass spectrometric (LC-MS-MS) analysis. Gradient elution separation was performed in 8 min at a flow rate of 1 mL min. No signal interfering with any of the analytes was found in fourteen blank hair samples from different sources. The limits of detection and quantification were 0.5 pg mg and 2.0 pg mg, respectively, for MA, AMP, MDMA, MDA, K, NK, and DHNK, and 2.0 pg mg and 5.0 pg mg, respectively, for 6-AM, MOR and COD. The linear range was between the LOQ and 1000 pg mg, and the correlation coefficients were all greater than 0.999. Investigation of matrix effects revealed that all the analytes were suppressed by less than 20 % and the standard deviation (SD) was always less than 7 %. Recovery was always greater than 90 % and the SD for each compound was less than 6 %. Precision and accuracy for each analyte were within 15 %. Eight authentic hair specimens from known drug abusers were successfully analyzed. Compared with traditional overnight incubation methods, the rapid 3-min extraction time achieved similar or greater extraction yields. Sample preparation by MAE was a reliable procedure for extraction of the analytes from hair but substantially simpler and faster than other methods. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The oxidation resistance of Ti–50Al intermetallics is improved bypreoxidation for 1, 4, or 16 hours in high-pressure, pure oxygen(≈3.9 atm) at 900°C. Specimens preoxidized for 1 hr exhibit betteroxidation resistance than others. Prolonged preoxidation time candeteriorate the oxidation resistance and reduce the parabolic-lineartransition time during subsequent cyclic oxidation in 800°C air. Theoxide-mound occurrence is an important factor for evaluating theeffectiveness of the preoxidation treatment in oxygen. The formationmechanism of Z-phase (Ti5Al3O2) in the Al-depleted layer beneath theflat oxide scale and that beneath the oxide mound are also proposed inthis study. [ABSTRACT FROM AUTHOR]

Studying the genetic diversity of nematode parasite populations is crucial to gaining insight into parasite infection dynamics and informing parasite phylogeography. Anisakiasis is a zoonotic disease caused by the consumption of infectious third-stage larvae (L3) of Anisakis spp. carried by marine fish. In the present study, a total of 206 mitochondrial DNA sequences (cytochrome c oxidase 2, cox2) were used to study the genetic diversity, genetic structure, and historical demography of twelve A. pegreffii populations from Trichiurus japonicas along the coast of mainland China and Taiwan. Two distinct evolutionary lineages of A. pegreffii and no significant genealogical structures corresponding to sampling localities suggested that isolation in the marginal seas shaped their patterns of phylogeographic distribution along the coast of mainland China and Taiwan during glaciation with lower sea levels. Furthermore, pairwise FST values and AMOVA did not indicate any significant genetic differentiation among groups with no relation to the geographic area, which might be attributed to fewer barriers to gene flow as well as large population sizes. The results of the neutrality test, mismatch distribution, and Bayesian skyline plot analyses showed that entire population underwent population expansion during the late Pleistocene. Analysis of the demographic history revealed that A. pegreffii underwent historical lineage diversification and admixture due to secondary contact based on ABC analysis. The present research represents the first definitive population structure and demographic history across sampling locations of A. pegreffii along the coast of mainland China and Taiwan. [ABSTRACT FROM AUTHOR]

Trichiurus nanhaiensis is one of the most important commercial fish species in the South China Sea. This study aimed to investigate the level of genetic variation and population genetic structure of T. nanhaiensis in the South China Sea for the first time, using 281 individuals collected from seven locations along the coast of mainland China, Taiwan, and Hainan Island. A high level of haplotype diversity and low nucleotide diversity were detected in the mitochondrial DNA cyt b gene and nuDNA RYR 3 gene. The overall expected heterozygosity (He = 0.693) among the seven populations ranged from 0.681 to 0.706 in microsatellite DNA data, which revealed high levels of genetic diversity. Significant genetic differentiation was found in Taidong populations in Taiwan, revealing the prevention of gene flow caused by the Kuroshio Current. Two major lineages based on the cyt b gene suggested that the Taiwan Strait acted as a geographic barrier for T. nanhaiensis during the glacier periods in the late Pleistocene. The Bayesian skyline plot also revealed that population demographic expansion of T. nanhaiensis was estimated to have occurred in 0.1 Mya. Our results indicated that all populations of T. nanhaiensis had experienced a recent genetic bottleneck following recent expansion based on ABC analysis. [ABSTRACT FROM AUTHOR]

Systemic sclerosis (SSc) is a destructive connective tissue disease characterized by dysregulation of the immune system and fibrosis in the skin and internal organs. The pathogenesis of SSc is complex and remains to be determined. So far, limited specific disease-modifying treatments are available for the effective control of fibrosis in patients with SSc. Studies from the past few years hint at the importance of immune dysfunctions, including the dysregulation of innate and adaptive immune cells, as well as the aberrant secretion of inflammatory and fibrotic cytokines, in the pathogenesis of SSc fibrosis. In this Review, we summarize the most pertinent findings concerning the involvement of dysregulated immune responses in fibrosis of the skin and lungs in SSc and highlight the current and potential immune-based targets for SSc therapeutics. [ABSTRACT FROM AUTHOR]

This study aims to investigate the incidence of hepatitis B virus (HBV) reactivation in inflammatory arthritis (IA) patients with HBV infection using anti-tumor necrosis factor (TNF) agents and evaluate the efficacy of antiviral therapy in reducing the risk of viral reactivation in chronic HBV infection. IA patients using anti-TNF agents from six centers were enrolled. Their HBV infection conditions and ALT and HBV-DNA levels were monitored periodically. Among the six chronic hepatitis B patients, HBV reactivation was found in two patients without antivirus prophylaxis and no viral replication was detected in the other four patients with antivirus prophylaxis. In the 31 inactive carriers, the increase of viral load was detected in 6 of 22 (27.3 %) patients without antiviral prophylaxis, and there was no viral reactivation in the other 9 patients with antiviral prophylaxis. HBV reactivation was not found in the 50 patients with resolved HBV infection. It is suggested that anti-TNF therapy might increase the risk of HBV reactivation in patients with chronic HBV infection, and antiviral prophylaxis could effectively decrease the risk. Anti-TNF agents seem to be safe in patients with resolved HBV infection. [ABSTRACT FROM AUTHOR]

To investigate the clinical pattern, survival rate, causes of death and risk factors in a large cohort of Chinese Han patients with systemic sclerosis (SSc). Inpatients treated from 2002 to 2014 were included in this study. Patients were classified into diffuse cutaneous SSc (dcSSc), limited cutaneous SSc (lcSSc), and SSc-overlap syndrome groups. Data were analyzed using Chi-squared tests, Kaplan-Meier curves, log-rank tests, and Cox proportional hazards modeling. Among a total of 201 patients, dcSSc (50.2%) was the major subtype, followed by lcSSc (30.3%) and SSc-overlap (19.4%). Interstitial lung disease (ILD, 148/201, 74%) was the most frequent organ involvement. The overall survival rates were 98% and 95% at 5 and 10 years, respectively. The overall standard mortality ratio (SMR) was 2.22. The most common cause of death was ILD combined with infection (8/16, 50%), followed by kidney failure (2/16, 12.5%). On crude analysis, pulmonary hypertension, ILD, cardiac involvements, renal involvements, and digital ischemia were associated with poor prognosis. On multivariate analysis, pericardial effusion (p = 0.000) and digital ischemia (p = 0.016) were independent prognostic factors of death. The mortality rate of patients with SSc is mildly increased in comparison with the general population. ILD is the most common systemic involvement and the principal cause of death in SSc. Pericardial effusion and digital ischemia are independent factors associated with death. [ABSTRACT FROM AUTHOR]

Adductomics is expected to be useful in the characterization of the exposome, which is a new paradigm for studying the sum of environmental causes of diseases. DNA adductomics is emerging as a powerful method for detecting DNA adducts, but reliable assays for its widespread, routine use are currently lacking. We propose a novel integrated strategy for the establishment of a DNA adductomic approach, using liquid chromatography-triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS), operating in constant neutral loss scan mode, screening for both known and unknown DNA adducts in a single injection. The LC-QqQ-MS/MS was optimized using a representative sample of 23 modified 2′-deoxyribonucleosides reflecting a range of biologically relevant DNA lesions. Six internal standards (ISTDs) were evaluated for their ability to normalize, and hence correct, possible variation in peak intensities arising from matrix effects, and the quantities of DNA injected. The results revealed that, with appropriate ISTDs adjustment, any bias can be dramatically reduced from 370 to 8.4%. Identification of the informative DNA adducts was achieved by triggering fragmentation spectra of target ions. The LC-QqQ-MS/MS method was successfully applied to in vitro and in vivo studies to screen for DNA adducts formed following representative environmental exposures: methyl methanesulfonate (MMS) and five N-nitrosamines. Interestingly, five new DNA adducts, induced by MMS, were discovered using our adductomic approach—an added strength. The proposed integrated strategy provides a path forward for DNA adductomics to become a standard method to discover differences in DNA adduct fingerprints between populations exposed to genotoxins, and facilitate the field of exposomics. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) hybridized poly(N-isopropylacrylamide)-co-acrylic acid (PNIPAM-co-AAc) hydrogel on thermoplastic polyurethane (TPU) were successfully prepared via photocatalytic polymerization technique. Low temperature plasma processing of HMDSZ and O plasma were deposition on substrate. The HA/hydrogel were stabilized by HA of which the wettability was modified by calcium nitrate and ammonium phosphate dibasic. The HA gradually increases with the increase of time cycles. The deposition of organic silicone group by the HMDSZ on the TPU substrate is hydrophobic surface. When deposition of O, the water contact angles (WCA) was changed to <10° and surface hydrophilicity. The materials were characterized by OM, SEM, FT-IR, XPS and XRD. The results showed that the NIPAM: AAc (1:1 mol) polymers possess macropores ranging from 2 to 20 μm, and their large numbers of carboxyl groups and hydroxyl groups result in a favorable adsorption capacity for HA. Swelling studies indicated that NIPAM: AAc (1:1 mol) was 446 ± 0.3%. This work provided a promising alternative method for the fabrication of polymer materials with tunable and interconnected pores structures for the HA. [ABSTRACT FROM AUTHOR]

Whether hyperuricemia is an independent risk factor for hypertension in adults is still under debate. To determine the association between serum uric acid and risk of hypertension in the Chinese population, we conducted a prospective study using the 'Kailuan Corporation cohort.' A total of 39,233 adult subjects with available data on serum uric acid were enrolled from 2006 to 2007. Subjects with established hypertension were excluded and were then grouped based on the gender and baseline quartile serum uric acid into F1-4 for women and M1-4 for men with F1 and M1 being the lowest quartiles. Incidence of newly described primary hypertension was reevaluated in 2010-2011. The median (interquantile range) baseline uric acid (UA) was 290 (243-344) μmol/L in men and 230 (194-274) μmol/L in women. During a 4-year follow-up period, 12,844 subjects (31.31 %) were newly diagnosed with hypertension. The incidence of hypertension was 14.36, 16.57, 19.06, and 22.35 % in F1 to F4 and 33.64, 33.97, 36.54, and 40.74 % in M1 to M4, respectively. Multiple logistic regression analysis showed that the odds ratios (ORs) of incident hypertension were 1.17 [95 % confidence interval (CI) 1.00-1.37, P = 0.055], 1.24 (95 % CI 1.06-1.45, P = 0.009), and 1.20 (95 % CI 1.02-1.41, P = 0.027) in F2 to F4 compared to the F1 and 0.98 (95 % CI 0.91-1.05, P = 0.534), 1.05 (95 % CI 0.98-1.13, P = 0.190), and 1.13 (95 % CI 1.05-1.22, P = 0.002) in M2 to M4 compared to the M1. Elevated level of serum uric acid is associated with an increased risk of hypertension in adults. [ABSTRACT FROM AUTHOR]

To evaluate the diagnosis value of antibodies to phosphatidylserine/prothrombin complex (aPS/PT) in patients with antiphospholipid syndrome (APS) and to determine the clinical features of APS patients with avidity of aPS/PT. Serum samples were collected from 108 APS patients. Sixty patients with pregnancy morbidity, 37 patients with thrombosis without a history of autoimmune diseases, and 89 healthy blood donors were included as the control group. The enzyme-linked immunosorbent assay (ELISA) test was performed to detect the concentration of aPS/PT, including IgG/M, IgG, and IgM forms, in the same serum sample. The chi-square (χ2) test was used to examine the difference of frequencies of antibodies in APS patients and patients with other diseases. Spearman correlation analysis was performed to investigate the relationship between aPS/PT and other clinical/laboratory parameters. aPS/PT was detectable in 68 (63.0%) of the 108 APS patients, 12 (13.2%) of the 91 disease control patients and 1 (1.1%) of the healthy controls. It was strongly correlated with the activity of lupus anticoagulant (LA) (OR 15.952, 95% CI 7.132-35.678; P < 0.001). The frequency of aPS/PT was 56.9% in anti-cardiolipid antibody (aCL)-negative, 60.5% anti-β2 glycoprotein I antibody (aβ2GPI)-negative, and 50.0% in both aCL and aβ2GPI negative APS patients. The IgG aPS/PT was significantly associated with arterial and venous thrombosis. The aPS/PT antibody could play an important role in the diagnosis of APS, especially in patients with negative aCL and aβ2GPI. It was positively related to thrombotic events in APS. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated that the mammalian target of rapamycin (mTOR) signaling pathway has an important role in ketamine-induced, rapid antidepressant effects despite the acute administration of fluoxetine not affecting mTOR phosphorylation in the brain. However, the effects of long-term fluoxetine treatment on mTOR modulation have not been assessed to date. In the present study, we examined whether fluoxetine, a type of commonly used antidepressant agent, alters mTOR signaling following chronic administration in different brain regions, including the frontal cortex, hippocampus, amygdala and hypothalamus. We also investigated whether fluoxetine enhanced synaptic protein levels in these regions via the activation of the mTOR signaling pathway and its downstream regulators, p70S6K and 4E-BP-1. The results indicated that chronic fluoxetine treatment attenuated the chronic, unpredictable, mild stress (CUMS)-induced mTOR phosphorylation reduction in the hippocampus and amygdala of mice but not in the frontal cortex or the hypothalamus. Moreover, the CUMS-decreased PSD-95 and synapsin I levels were reversed by fluoxetine, and these effects were blocked by rapamycin only in the hippocampus. In conclusion, our findings suggest that chronic treatment with fluoxetine can induce synaptic protein expression by activating the mTOR signaling pathway in a region-dependent manner and mainly in the hippocampus. [ABSTRACT FROM AUTHOR]

8-Oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodGuo) is the most investigated product of oxidatively damaged DNA lesion that has been associated with the development of aging, cancer and some degenerative diseases. Here, we present the first liquid chromatography-tandem mass spectrometry method that enables the simultaneous measurement of its repair products in plasma and saliva, namely 8-oxo-7,8-dihydroguanine (8-oxoGua) and 8-oxodGuo. Using this method, we investigated the underlying transport mechanism of the repair products of oxidatively damaged DNA between cellular compartments and biological matrices. Plasma, saliva and urine samples were collected concurrently from 57 healthy subjects. Various deproteinization methods were evaluated, and the precipitants acetonitrile and sodium hydroxide-methanol were, respectively, selected for plasma and saliva samples due to their effect on recovery efficiencies and chromatography. The mean baseline concentrations of 8-oxoGua and 8-oxodGuo in plasma were demonstrated to be 0.21 and 0.016 ng/mL, respectively, while in saliva they were 0.85 and 0.010 ng/mL, respectively. A relatively high concentration of 8-oxoGua was found in saliva with a concentration factor (CF, concentration ratio of saliva to plasma) of 4 as compared to that of 8-oxodGuo (CF: 0.6), implying that 8-oxoGua in plasma may be actively transported to saliva, whereas 8-oxodGuo was most dependent on a passive diffusion. Good correlations between urine and plasma concentrations were observed for 8-oxoGua and 8-oxodGuo, suggesting that blood was a suitable matrix in addition to urine. Significant correlation between 8-oxoGua and 8-oxodGuo in urine was only observed when the concentrations were not corrected for urinary creatinine, raising the issue of applicability of urinary creatinine to adjust 8-oxoGua concentrations. [ABSTRACT FROM AUTHOR]

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and its urinary metabolite, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), are the most investigated carcinogenic biomarkers of tobacco-specific nitrosamines. Here, we report the development of a sensitive and selective assay based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) to simultaneously measure urinary NNK and NNAL. With the use of isotope internal standards and online solid-phase extraction, urine samples were directly analyzed without prior sample purification. The detection limits of this method were 0.13 and 0.19 pg on column for NNK and NNAL, respectively. Inter- and intra-day imprecision was <10 %. Mean recovery of NNK and NNAL in urine was 99-100 %. This method was applied to measure urinary NNK and NNAL in 101 smokers and 40 nonsmokers to assess tobacco exposure. Urinary nicotine, cotinine, N3-methyladenine (N3-MeA), and N7-methylguanine (N7-MeG) were also measured by isotope-dilution LC-MS/MS methods. The results showed that urinary NNK was not observed in all smokers. Urinary free NNAL (0.10 ± 0.09 ng/mg creatinine) and total NNAL (0.17 ± 0.14 ng/mg creatinine) were detected in all smokers. Urinary concentrations of NNAL were significantly correlated with nicotine, cotinine, N3-MeA, and N7-MeG in smokers ( P < 0.001). This method enables the direct and simultaneous measurement of NNK and NNAL in urine using only 50 μL of urine. This study first demonstrated in human that urinary tobacco-specific nitrosamines metabolite (NNAL) are highly correlated with their resulting methylated DNA lesions in urine, which may help to substantiate an increased cancer risk associated with tobacco smoke exposure. [ABSTRACT FROM AUTHOR]

Global analyses of DNA methylation contribute important insights into biology and the wide-ranging role of DNA methylation. We describe the use of online solid-phase extraction and isotope-dilution liquid chromatography/tandem mass spectrometry (LC-MS/MS) for the simultaneous measurement of 5-methyl-2′-deoxycytidine (5-medC) and 2′-deoxycytidine (dC) in DNA. With the incorporation of isotope internal standards and online enrichment techniques, the detection limit of this method was estimated to be as low as 0.065 pg which enables human global DNA methylation detection using only picogram amounts of DNA. This method was applied to assess the optimal amounts of enzymes required for DNA digestion regarding an accurate global DNA methylation determination and completeness of digestion and to determine global methylation in human tumor adjacent lung tissue of 79 lung cancer patients. We further determined methylated ( N7-methylguanine ( N7-meG), O-methylguanine ( O-meG), and N3-methyladenine ( N3-meA)) and oxidized DNA lesions (8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG)) in lung cancer patients by LC-MS/MS. Optimization experiments revealed that dC was liberated from DNA much more readily than 5-medC by nuclease P1 and alkaline phosphatase (AP) in DNA, which could lead to an error in the global DNA methylation measurement following digestion with insufficient enzymes. Nuclease P1 showed more differential activity for 5-medC and dC than AP. Global DNA methylation levels in adenocarcinoma and squamous cell carcinoma patients were similar in the range of 3.16-4.01 %. Global DNA methylation levels were not affected by smoking and gender and were not correlated with N7-meG or 8-oxodG in lung cancer patients. Levels of O-meG and N3-meA were however found to be undetectable in all lung tissue samples. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Since methylation at the N-7 and O positions of guanine and the N-3 position of adenine in DNA are the predominant reaction sites, N -methylguanine ( N -MeG), O -methylguanine ( O -MeG), and N -methyladenine ( N -MeA) have been suggested as good biomarkers for assessing exposure to methylating agents. Here, we report the development of a sensitive and selective assay based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) to simultaneously measure N -MeG, O -MeG, and N -MeA in DNA hydrolysates. With the use of isotope internal standards (N- N -MeG, d - O -MeG, and d - N -MeA) and online solid-phase extraction, DNA hydrolysates can be directly analyzed within 12 min without prior sample purification. The limits of detection were 0.02, 0.002, and 0.01 ng/mL on-column (6.1, 0.6, and 3.4 fmol) for N -MeG, O -MeG, and N -MeA, respectively. Inter- and intraday imprecision (CV) were 3.6-9.6% and 2.7-13.6%, respectively. Mean recoveries were 96-109%. This method was then applied to quantitate the amounts of methylated purines in calf thymus DNA treated with methyl methanesulfonate (MMS). The levels of N -MeG, O -MeG, and N -MeA in calf thymus DNA increase with MMS concentration and incubation time. The ratio of relative yields of N -MeG, O -MeG, and N -MeA in MMS-treated DNA was found to be 1.00:0.0032:0.119, respectively. This LC-MS/MS assay provides the sensitivity and high throughput required to evaluate the extent of methylated lesions in DNA induced by methylating agents. [ABSTRACT FROM AUTHOR]

The mobile incoherent Doppler lidar (MIDL), which was jointly developed by State Key Laboratory of Severe Weather (LaSW) of the Chinese Academy of Meteorological Sciences (CAMS) and Ocean University of China, provided meteorological services during the Olympic sailing events in Qingdao in 2008. In this study, two experiments were performed based on these measurements. First, the capabilities of MIDL detection of sea-surface winds were investigated by comparing its radial velocities with those from a sea buoy. MIDL radial velocity was almost consistent with sea-buoy data; both reflected the changes in wind with time. However, the MIDL data was 0.5 m s lower on average than the sea-buoy data due to differences in detection principle, sample volume, sample interval, spatial and temporal resolution. Second, the wind fields during the Olympic sailing events were calculated using a four-dimensional variation data assimilation (4DVAR) algorithm and were evaluated by comparing them with data from a sea buoy. The results show that the calculations made with the 4DVAR wind retrieval method are able to simulate the fine retrieval of sea-surface wind data-the retrieved wind fields were consistent with those of sea-buoy data. Overall, the correlation coefficient of wind direction was 0.93, and the correlation coefficient of wind speed was 0.70. The distribution of retrieval wind fields was consistent with that of MIDL radial velocity; the root-mean-square error between them had an average of only 1.52 m s. [ABSTRACT FROM AUTHOR]

Betel quid chewing has been associated with several human cancers. However, the role of betel quid in carcinogenesis remains uncertain. Piper betle contains high concentrations of safrole (an inducer of DNA oxidative damage). Safrole may be metabolized by hepatic sulfotransferase 1A1 (SULT1A1), or glutathione S-transferases (GSTM1, GSTT1, and GSTP1). Thus, we investigated the association of genetic polymorphisms of SULT1A1, GSTM1, GSTT1, and GSTP1 with DNA oxidative damage among betel quid chewers. A biomarker for oxidative stress, urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) level, was analyzed using isotope-dilution LC–MS/MS in 64 betel quid chewers and 129 non-betel quid chewers. Data on demographics and habits (smoking, alcohol drinking, and betel quid chewing) were obtained from questionnaires. Our results revealed that urinary 8-OHdG level was higher in chewers with SULT1A1 Arg-His genotype than in chewers with SULT1A1 Arg-Arg genotype. Urinary 8-OHdG level was also higher in chewers with GSTP1 Ile-Ile genotype. Furthermore, the combined effect of SULT1A1 and GSTP1 genotypes on urinary 8-OHdG was evaluated. Non-chewers with both SULT1A1 Arg-Arg and GSTP1 Val-Val/Ile-Val (reference group) had the lowest mean level (3.6 ng/mg creatinine), whereas chewers with either SULT1A1 Arg-His or GSTP1 Ile-Ile had the highest 8-OHdG mean level (6.2 ng/mg creatinine; vs. reference group, P = 0.04). Chewers with both of SULT1A1 Arg-Arg and GSTP1 Val-Val/Ile-Val (4.6 ng/mg creatinine), and non-chewers with either SULT1A1 Arg-His or GSTP1 Ile-Ile (4.7 ng/mg creatinine) had a moderately increased 8-OHdG level. Thus, the susceptible SULT1A1 and GSTP1 genotypes may modulate increased DNA oxidative stress elicited by betel-quid chewing. [ABSTRACT FROM AUTHOR]

Stress among university faculty has received considerable treatment in research literature in the past decade in higher education, but very little study has been undertaken from a comparative perspective. This paper reports the results of a comparative study in measuring stress among university faculty in China and Japan using a questionnaire survey. It analyzes the relationship between stress and health in different age groups of the faculty and the differences in the nature and structure of the stress between China and Japan. The research suggests that stress of Chinese and Japanese university faculty can be described as ``social-transformation stress'' and ``direction-conflict stress'', respectively. [ABSTRACT FROM AUTHOR]