Assessment of Lung Nodule Detection and Lung CT Screening Reporting and Data System Classification Using Zero Echo Time Pulmonary MRI.

BACKGROUND: The detection rate of lung nodules has increased considerably with CT as the primary method of examination, and the repeated CT examinations at 3 months, 6 months or annually, based on nodule characteristics, have increased the radiation exposure of patients. So, it is urgent to explore a radiation-free MRI examination method that can effectively address the challenges posed by low proton density and magnetic field inhomogeneities. PURPOSE: To evaluate the potential of zero echo time (ZTE) MRI in lung nodule detection and lung CT screening reporting and data system (lung-RADS) classification, and to explore the value of ZTE-MRI in the assessment of lung nodules. STUDY TYPE: Prospective. POPULATION: 54 patients, including 21 men and 33 women. FIELD STRENGTH/SEQUENCE: Chest CT using a 16-slice scanner and ZTE-MRI at 3.0T based on fast gradient echo. ASSESSMENT: Nodule type (ground-glass nodules, part-solid nodules, and solid nodules), lung-RADS classification, and nodule diameter (manual measurement) on CT and ZTE-MRI images were recorded. STATISTICAL TESTS: The percent of concordant cases, Kappa value, intraclass correlation coefficient (ICC), Wilcoxon signed-rank test, Spearman's correlation, and Bland-Altman. The p-value <0.05 is considered significant. RESULTS: A total of 54 patients (age, 54.8 ± 11.9 years; 21 men) with 63 nodules were enrolled. Compared with CT, the total nodule detection rate of ZTE-MRI was 85.7%. The intermodality agreement of ZTE-MRI and CT lung nodules type evaluation was substantial (Kappa = 0.761), and the intermodality agreement of ZTE-MRI and CT lung-RADS classification was moderate (Kappa = 0.592). The diameter measurements between ZTE-MRI and CT showed no significant difference and demonstrated a high degree of interobserver (ICC = 0.997-0.999) and intermodality (ICC = 0.956-0.985) agreements. DATA CONCLUSION: The measurement of nodule diameter by pulmonary ZTE-MRI is similar to that by CT, but the ability of lung-RADS to classify nodes from MRI images still requires further research. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 2.

Spatial distribution, source apportionment and potential ecological risk assessment of suspended atmosphere microplastics in different underlying surfaces in Harbin.

Although suspended atmospheric microplastics (SAMPs) have been found to be ubiquitous and have potential impacts on human health, whereas studies related to source apportionment and potential ecological risk assessment in the atmospheric environment are still limited. This study investigated spatial distribution, source apportionment and potential ecological risk of SAMPs in six underlying surfaces of Harbin, China. The results show that all six underlying surfaces existed SAMPs, including polypropylene (PP), polyethylene terephthalate (PET) polyethylene (PE), polystyrene (PS) and polyvinyl chloride (PVC), with approximate 26.13 %, 24.10 %, 23.87 %, 13.51 %, and 12.39 %, respectively. SAMPs abundances from filtered air were relatively high and averaged 1.76 n/m3. The SAMPs mainly contained fibrous (59.01 %), fragmented (30.18 %), and granular (10.81 %) with transparent (62.39 %), black 13.74 %), red (7.43 %), white (6.53 %), blue, and yellow (3.60 %), and particle size ranged from 1.3 to 518 µm. In addition, source apportionment of SAMPs shows that SAMPs were originated from five emission sources including living source (19.53 %), construction source (12.08 %), transportation source (47.25 %), industrial source (5.11 %), and agricultural source (16.13 %) in Harbin. A significant correction was observed between SAMPs abundances and human activity (R = 0.68, P = 0.66), atmospheric humidity (R = -0.40, P = 0.02), and wind direction (R = 0.22, P = 0.04) in different underlying surface. Furthermore, potential ecological hazardous single index (EI) of PVC and PS were higher than PP, PET, and PS in the construction land, cultivated land, forest land, grassland, water area, and unused land. An estimation of the potential ecological risk index (RI) from SAMPs using Positive Matrix Factorization (PMF) model indicated that Harbin presented a minor ecological risk with average 16.59 of RI index of microplastics in environments. In conclusion, data in this study indicate that SAMPs are existed in atmospheric environments, which have possible risks for human health via inhalation.

Symptoms assessment and decision to treat patients with advanced Parkinson's disease based on wearables data.

Body-worn sensors (BWS) could provide valuable information in the management of Parkinson's disease and support therapeutic decisions based on objective monitoring. To study this pivotal step and better understand how relevant information is extracted from BWS results and translated into treatment adaptation, eight neurologists examined eight virtual cases composed of basic patient profiles and their BWS monitoring results. Sixty-four interpretations of monitoring results and the subsequent therapeutic decisions were collected. Relationship between interrater agreements in the BWS reading and the severity of symptoms were analyzed via correlation studies. Logistic regression was used to identify associations between the BWS parameters and suggested treatment modifications. Interrater agreements were high and significantly associated with the BWS scores. Summarized BWS scores reflecting bradykinesia, dyskinesia, and tremor predicted the direction of treatment modifications. Our results suggest that monitoring information is robustly linked to treatment adaptation and pave the way to loop systems able to automatically propose treatment modifications from BWS recordings information.

Comparison of the predictive value of intrinsic capacity and comorbidity on adverse health outcome in community-dwelling older adults.

OBJECTIVES: To compare the predictive value of intrinsic capacity (IC) and comorbidity on all-cause mortality and falls. METHODS: This prospective cohort study included 220 older adults (84.0±4.4 years) followed for 3 years in a community in Beijing. The methodology recommended by the World Health Organization was used to assess IC, and comorbidity was assessed by the Cumulative Illness Rating Scale for Geriatrics. RESULTS: The areas under the characteristic curve of IC and comorbidity were 0.78 vs. 0.67 (p=0.033), respectively, in predicting all-cause mortality, and 0.69 vs. 0.61 in predicting falls (p=0.032). The vitality domain impairment (odds ratio [OR]=3.28, p=0.013), and cognition domain impairment (OR=3.97, p=0.004) were significantly associated with all-cause mortality. Locomotion domain impairment (OR=2.35, p=0.010) was associated with higher fall risk. CONCLUSION: IC might be a better predictor than comorbidity in community-dwelling older adults, in which the vitality, locomotion and cognition domains should be given more attention.

Selective parenchymal clamping in open partial nephrectomy: Early experience with a low cost, reusable novel parenchymal clamp.

Objectives: The objective of this study is to present our initial experience with a novel parenchymal clamp (NPC) developed to allow partial nephrectomies (PN) to be performed without whole kidney ischaemia. We compare patients who underwent PN with the NPC with those undergoing standard PNs. Methods: The NPC applies pressure only to the portion of the parenchyma containing the small renal mass (≤3.5 cm) and interrupts regional blood flow.A retrospective analysis was conducted on patients that underwent open PN within our unit. Minimum follow-up was 12 months. Patient and disease characteristics, perioperative outcomes and renal function estimated Glomerular Filtration Rate (eGFR) were compared. Results: Data were collected on 63 patients, of whom 33 had their procedure performed with the NPC. Demographic characteristics and comorbidity profiles were not significantly different between groups (p between 1.0 and 0.08). RENAL nephrometry scores were 5.6 in the NPC group versus 6.2 in the standard PN group (p = 0.146).Perioperative, operative and postoperative data did not show significant differences. There was no difference in the rates of Clavien-Dindo III or above complications between the two groups (NPC 3/33 vs. standard PN 5/30, p = 0.416). There was also no statistically significant difference to changes in renal functional at 12 months (change -5.2 and -6.4, p = 0.712). Conclusions: Despite the limited sample size and follow-up, this study establishes the safety of the NPC. In the future, we intend to perform a prospective study on the laparoscopic version.

Atmospheric Particle Hygroscopicity and the Influence by Oxidation State of Organic Aerosols in Urban Beijing.

A hygroscopic tandem differential mobility analyser (H-TDMA) was used to observe the size-resolved hygroscopic characteristics of submicron particles in January and April 2018 in urban Beijing. The probability distribution of the hygroscopic growth factor (HGF-PDF) in winter and spring usually showed a bimodal pattern, with more hygroscopic mode (MH) being more dominant. The seasonal variation in particle hygroscopicity was related to the origin of air mass, which received polluted southerly air masses in spring and clean northwesterly air masses in winter. Particles showed stronger hygroscopic behaviour during heavy pollution episodes (HPEs) with elevated concentrations of secondary aerosols, especially higher mass fraction of nitrate, which were indicated using the PM2.5 (particulate matter with diameter below 2.5 µm) mass concentration normalised by CO mass concentration. The hygroscopic parameter (κ) values were calculated using H-TDMA (κhtdma) and chemical composition (κchem). The closure study showed that κchem was overestimated in winter afternoon when compared with κhtdma, because the organic particle hygroscopic parameter (κorg) was overestimated in the calculations. It was influenced by the presence of a high concentration of hydrocarbon-like organic aerosol (HOA) with a weak water uptake ability. A positive relationship was observed between κorg and the ratio of oxygenated organic aerosol (OOA) and HOA, thereby indicating that the strong oxidation state enhanced the hygroscopicity of the particles. This study revealed the effect of local emission sources and secondary aerosol formation processes on particle hygroscopicity, which is of great significance for understanding the pollution formation mechanism in the North China Plain.

Spatiotemporal Variations of Carbon Emissions and Their Driving Factors in the Yellow River Basin.

The Yellow River Basin (YRB) is a significant area of economic development and ecological protection in China. Scientifically clarifying the spatiotemporal patterns of carbon emissions and their driving factors is of great significance. Using the methods of spatial autocorrelation analysis, hot-spot analysis, and a geodetector, the analysis framework of spatiotemporal differentiation and the driving factors of carbon emissions in the YRB was constructed in this paper from three aspects: natural environment, social economy, and regional policy. Three main results were found: (1) The carbon emissions in the YRB increased gradually from 2000 to 2020, and the growth rates of carbon emissions in the different river reaches were upper reaches > middle reaches > lower reaches. (2) Carbon emissions have an obvious spatial clustering character from 2000-2020, when hot spots were concentrated in the transition area from the Inner Mongolia Plateau to the Loess Plateau. The cold spots of carbon emissions tended to be concentrated in the junction area of Qinghai, Gansu, and Shaanxi. (3) From 2000 to 2020, the driving factors of spatial differentiation of carbon emissions in the YRB and its different reaches tended to be diversified, so the impacts of socioeconomic factors increased, while the impacts of natural environmental factors decreased. The influence of the interactions of each driving factor showed double factor enhancement and nonlinear enhancement. This study will provide a scientific reference for green and low-carbon development, emphasizing the need to pay more attention to environmental protection, develop the green economy vigorously, and promote the economic cycle, so as to achieve green development and reduce carbon emissions.

A sustainable and economic strategy to reduce risk antibiotic resistance genes during poultry manure bioconversion by black soldier fly Hermetia illucens larvae: Larval density adjustment.

Black soldier fly (Hermetia illucens) larvae (BSFL) are common insects that are known for bioconversion of organic waste into a sustainable utilization resource. However, a strategy to increase antibiotic resistance gene (ARG) elimination in sustainable and economic ways through BSFL is lacking. In the present study, different larval densities were employed to assess the mcr-1 and tetX elimination abilities, and potential mechanisms were investigated. The application and economic value of each larval density were also analyzed. The results showed that the 100 larvae cultured in 100 g of manure group had the best density because the comprehensive disadvantage evaluation ratio was the lowest (14.97%, good bioconversion manure quality, low ARG deposition risk and reasonable larvae input cost). Further investigation showed that mcr-1 could be significantly decreased by BSFL bioconversion (4.42 ×107 copies/g reduced to 4.79 ×106-2.14 ×105 copies/g)(P＜0.05); however, mcr-1 was increasingly deposited in the larval gut with increasing larval density. The tetX abundance was stabilized by BSFL bioconversion, except that the abundance at the lowest larval density increased (1.22 ×1010 copies/g increase, 34-fold). Escherichia was the host of mcr-1 and tetX in all samples, especially in fresh manure; Alcaligenes was the host of tetX in bioconversion manure; and the abundance of Alcaligenes was highly correlated with the pH of bioconversion manure. The pH of bioconversion manure was extremely correlated with the density of larvae. Klebsiella and Providencia were both hosts of tetX in the BSF larval gut, and Providencia was also the host of mcr-1 in the BSF larval gut. The density of larvae influenced the bioconversion manure quality and caused the ARG host abundance to change to control the abundance of ARGs, suggesting that larval density adjustment was a useful strategy to manage the ARG risk during BSFL manure bioconversion.

Prevalence and Influencing Factors of Depression Self-Management Among Chinese Community Residents: A Cross-Sectional Study.

Objective: This study aimed to investigate the current status of depression self-management (DSM), and to identify influencing factors of DSM among Chinese community residents. Methods: Stratified random sampling methodology was adopted in this cross-sectional survey. Respondents completed a collection of self-administered questionnaires Results: The majority of participants were female (72.2%), having a mean age of 39 years (SD = 17.3). The total mean score on the DSSM was low (31.63 ± 4.69). Using multiple linear regression analysis, age ranging from 25 to 64 years old (Beta = -0.176, p = 0.008), having personal stigma (Beta = -0.143, p = 0.020) and perceived stigma (Beta = 0.127, p = 0.037), and having a nuclear family structure (Beta = -0.313, p = 0.046), good family function (Beta = 0.278, p < 0.001) and good help-seeking attitude (Beta = 0.159, p = 0.008) were associated with DSSM-knowledge. Older age (≥65 years) (Beta = -0.152, p = 0.034), higher CES-D scores (Beta = -0.162, p = 0.005), having a father with a bachelor's degree or higher level of education (Beta = -0.134, p = 0.047), being female (Beta = 0.147, p = 0.012), indicating a religious preference (Beta = 0.145, p = 0.017) and having good family function (Beta = 0.247, p = 0.001) were significantly associated with DSSM-activities. Conclusions: Reducing stigma related to depression and enhancing help-seeking attitudes may be potential strategies for managing depressive symptoms among Chinese community residents.

[Inpatient Care Expenditure of Terminally Ill Patients in the Geriatric Ward of Peking Union Medical College Hospital].

Objective To describe the inpatient care expenditure of the terminally ill patients in the geriatric ward of Peking Union Medical College Hospital and facilitate future research on the economic outcomes of hospice and palliative care.Methods The histories of patients admitted to the Department of Geriatrics of Peking Union Medical College Hospital during 2018 were reviewed by trained doctors.According to the diagnosis and overall health state,terminally ill patients were selected and enrolled in the study.Demographics,health and disease information,prescriptions,and expenditure details were retrieved from the HIS system.Results In 2018,35 patients were terminally ill and eligible for hospice care,including 20 males and 15 females,with the average age of(78±8)years(59-91 years),the average age-adjusted Charlson Comorbidity Index of 10±3,and the median Barthel index of 40(10,70).These patients had malignant tumor(23 cases),heart failure(4 cases),end-stage renal disease(1 case),end-stage liver disease(2 cases),dementia(4 cases)and other severe diseases(3 cases).The patients received standard care within the scope of internal medicine and geriatrics.Finally,8 patients died during hospitalization,and 27 were discharged alive.The 35 patients had the median length of stay of 15(12,23)days,the median inpatient expenditure of CNY 21 500(13 800,37 600),and the median daily expenditure of CNY 1425(970,2503).The percentage of expenditure was(28.5±12.3)% for medication,(33.2±18.0)% for tests and examinations,and 11.5%(6.4%,15.8%)for accommodation and medical services.The medications for symptom control costed CNY(77±58)per day on average,accounting for(5.2±3.5)% of the total expenditure.Conclusions The inpatient expenditure for terminally ill patients in the tertiary grade A hospital was higher than that reported in community hospitals providing hospice care.In terms of expenditure constitution,the money spent on medications and tests/examinations were similar,and the percentage of expenditure on medications for symptom control was low.There is a need for further research on the economic impact of hospice and palliative care among terminally ill patients in China.

Artificial Intelligence-Based Assessment of Indices of Right Ventricular Function.

OBJECTIVES: Echocardiographic assessment of right ventricular (RV) function is based largely on visual estimation of tricuspid annulus and motion of the free wall. Regional strain analysis has provided an objective measure of myocardial performance assessment, but is limited in use by vendor-specific software. The study was designed to investigate statistical correlation between RV region-specific strain and echocardiographic parameters of RV function using a vendor-neutral RV-specific strain assessment program. DESIGN: This is a retrospective study. SETTING: Tertiary hospital. PARTICIPANTS: One hundred seven patients undergoing coronary artery bypass graft, valve repair or replacement, or a combination of procedures. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: One hundred seven patients underwent comprehensive echocardiographic of RV function intraoperatively. Off-line analysis of global, longitudinal, and septal strain was performed using a vendor-neutral software. The 2 values were compared statistically. All pairs demonstrated strong statistical significance; the strongest relationships were between (1) RV fractional area change (FAC) (%)-RV longitudinal strain (r2 = 0.83, p < 0.001), and (2) tricuspid annular plane systolic excursion (mm)-lateral S' velocity (cm/s) (r2 = 0.80, p < 0.001). The weakest correlations were (1) RV FAC (%)-lateral S' velocity (cm/s) (r2 = 0.37, p < 0.001), and (2) lateral S' velocity (cm/s)-RV longitudinal strain (r2 = 0.40, p < 0.001). CONCLUSION: RV function can be assessed objectively by strain analyses across different platforms using the artificial intelligence-based vendor-neutral strain analysis software. There is a statistically significant correlation between strain values and conventional 2-dimensional echocardiographic parameters of RV function.

Assessment of O3-induced yield and economic losses for wheat in the North China Plain from 2014 to 2017, China.

Tropospheric ozone (O3) is a pollutant of widespread concern in the world and especially in China for its negative effects on agricultural crops. For the first time, yield and economic losses of wheat between 2014 and 2017 were estimated for the North China Plain (NCP) using observational hourly O3 data from 312 monitoring stations and exposure-response functions based on AOT40 index (accumulated hourly O3 concentration above 40 ppb) from a Chinese study. AOT40 values from 2014 to 2017 during the wheat growing seasons (75-days, 44 before and 30 after mid-anthesis) ranged from 3.1 to 14.9 ppm h, 4.9-17.5 ppm h, 7.3-17.6 ppm h, and 0.5-18.6 ppm h, respectively. The highest AOT40 values were observed in the Beijing-Tianjin-Hebei region. The values of relative yield losses from 2014 to 2017 were in the ranges of 6.4-30.5%, 10.0-35.8%, 14.9-34.1%, and 21.6-38.2%, respectively. The total wheat production losses in NCP for 2014-2017 accounted for 18.5%, 22.7%, 26.2% and 30.8% in the whole production, while the economic losses amounted to 6,292 million USD, 8,524 million USD, 10,068 million USD, and 12,404 million USD, respectively. The important impact of O3 in this area, which is of global importance, should be considered when assessing wheat yield production. Our results also show an increasing trend in AOT40, relative yield loss, total crop production loss and economic loss in the four consecutive years.

PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in Beijing: Seasonal variations, sources, and risk assessment.

Polycyclic aromatic hydrocarbons (PAHs) have been of health concern due to its carcinogenesis and mutagenesis. In this study, we aimed to assess the variations, sources, and lifetime excessive cancer risk (ECR) attributable to PAHs bound to ambient particulate matters with aerodynamic diameter less than 2.5µm (PM2.5) in metropolitan Beijing, China. We collected 24-hour integrated PM2.5 samples on daily basis between November 2014 and June 2015 across both central heating (cold months) and non-heating (warm months) seasons, and further analyzed the PAH components in these daily PM2.5 samples. Our results showed that total concentrations of PM2.5-bound PAHs varied between (88.6±75.4)ng/m3 in the cold months and (11.0±5.9)ng/m3 in the warm months. Benzo[a]pyrene (BaP), the carcinogenic marker of PAHs, averaged at 5.7 and 0.4ng/m3 in the cold and warm months, respectively. Source apportionment analyses illustrated that gasoline, biomass burning, diesel, coal combustion and cooking were the major contributors, accounting for 12.9%, 17.8%, 24.7%, 24.3% and 6.4% of PM2.5-bound PAHs, respectively. The BaP equivalent lifetime ECR from inhalation of PM2.5-bound PAHs was 16.2 cases per million habitants. Our results suggested that ambient particulate reduction from energy reconstruction and adaption of clean fuels would result in reductions PM2.5-bound PAHs and its associated cancer risks. However, as only particulate phased PAHs was analyzed in the present study, the concentration of ambient PAHs could be underestimated.

Are current Chinese national ambient air quality standards on 24-hour averages for particulate matter sufficient to protect public health?

With rapid economic development and urbanization in recent decades, China has experienced the worsening of ambient air quality. For better air quality management to protect human health, Chinese government revised national ambient air quality standards (NAAQS) for particulate matter (PM) in 2012 (GB3095-2012). To assess the effectiveness of current NAAQS for PM on public health in Chinese population, we conducted a meta-analysis on published studies examining the mortality risk of short-term exposure to PM with aerodynamic diameters less than 10 and 2.5µm (PM10 and PM2.5) in China. The reported 24-hour concentrations of PM10 and PM2.5 in studies ranged from 43.5 to 150.1µg/m3 and 37.5 to 176.7µg/m3. In the pooled excess, mortality risk estimates of short-term exposure to PM. In specific, per 10µg/m3 increase in PM10, we observed increases of 0.40% (95%CI: 0.33%, 0.47%), 0.57% (95%CI: 0.44%, 0.70%) and 0.49% (95%CI: 0.40%, 0.58%) in total, respiratory and cardiovascular mortality, per 10µg/m3 increase in PM2.5, we observed increases of 0.51% (95%CI: 0.38%, 0.63%), 0.62% (95%CI: 0.52%, 0.73%) and 0.75% (95%CI: 0.54%, 0.95%) in total, respiratory and cardiovascular mortality. Finally, we derived 125µg/m3 for PM10 and 62.5µg/m3 for PM2.5 as 24-hour recommendation values based on the pooled estimates. Our results indicated that current Chinese NAAQS for PM could be sufficient in mitigating the excess mortality risk from short-term exposure to ambient PM. However, future research on long-term exposure cohort studies in Chinese population is also essential in revising annual averages for PM in Chinese NAAQS.

[Pollution Assessment and Spatial Distribution Characteristics of Heavy Metals in Soils of Coal Mining Area in Longkou City].

The present paper takes the coal mining area of Longkou City as the research area. Thirty-six topsoil (0-20 cm) samples were collected and the contents of 5 kinds of heavy metals were determined, including Cd, As, Ni, Ph, Cr. Geo-statistics analysis was used to analyze the spatial distribution of heavy metals. Principal component analysis (PCA) was used to explore the pollution sources of heavy metals and the degree of heavy metals pollution was evaluated by weighted average comprehensive pollution evaluation method. The results showed that enrichment phenomenon was significant for the 5 kinds of heavy metals. Taking secondary standard of National Environment Quality Standard for Soil as the background value, their exceed standard rates were 72.22%, 100%, 100%, 91.67%, 100%, respectively. Average contents of heavy metals in the soil samples were all over the national standard level two and were 1.53, 11.86, 2.40, 1.31, 4.09 times of the background value. In addition, the average contents were much higher than the background value of the topsoil in the eastern part of Shandong Province and were 9.85, 39.98, 8.85, 4.29, 12.71 times of the background value. According to the semivariogram model, we obtained the nugget-effects of 5 kinds of heavy metals and their values were in the order of As (0.644) > Cd (0.627) > Cr (0.538) > Ni (0.411) > Pb (0.294), all belonging to moderate spatial correlation. On the whole, the central part of the Sangyuan Coal Mine and its surrounding areas were the most seriously polluted, while the pollution of heavy metals in the east and west of the study area was relatively light. Principal component analysis suggested that the enrichment of Cd, As, Ni, Cr was due to irrigation of wastewater, the discharge of industry and enterprise, and the industrial activity. Automobile exhaust and coal combustion were the main pollution sources of Pb. The single-factor assessment of heavy metals pollution showed that the degree of different heavy metals pollution was in the order of As > Cr > Ni > Cd > Pb. Simultaneously, comprehensive pollution evaluation showed that the degree of heavy metals pollution in the study area was very serious, with comprehensive pollution index ranging from 2.17 to 4.66, among which, the numbers of moderate and heavy pollution samples were 10 and 26, respectively. Areas with heavy pollution were mainly distributed in the Sangyuan Coal Mine, Beizao Coal Mine, Liuhai Coal Mine; and the areas with moderate pollution covered Wali Coal Mine, Liangjia Coal Mine, and other regions. The results of this paper will provide data reference and theoretical support for the study of ecological risk assessment in the study area.

Comprehensive Assessment of Oxidatively Induced Modifications of DNA in a Rat Model of Human Wilson's Disease.

Defective copper excretion from hepatocytes in Wilson's disease causes accumulation of copper ions with increased generation of reactive oxygen species via the Fenton-type reaction. Here we developed a nanoflow liquid chromatography-nanoelectrospray ionization-tandem mass spectrometry coupled with the isotope-dilution method for the simultaneous quantification of oxidatively induced DNA modifications. This method enabled measurement, in microgram quantities of DNA, of four oxidative stress-induced lesions, including direct ROS-induced purine cyclonucleosides (cPus) and two exocyclic adducts induced by byproducts of lipid peroxidation, i.e. 1,N(6)-etheno-2'-deoxyadenosine (εdA) and 1,N(2)-etheno-2'-deoxyguanosine (εdG). Analysis of liver tissues of Long-Evans Cinnamon rats, which constitute an animal model of human Wilson's disease, and their healthy counterparts [i.e. Long-Evans Agouti rats] showed significantly higher levels of all four DNA lesions in Long-Evans Cinnamon than Long-Evans Agouti rats. Moreover, cPus were present at much higher levels than εdA and εdG lesions. In contrast, the level of 5-hydroxymethyl-2'-deoxycytidine (5-HmdC), an oxidation product of 5-methyl-2'-deoxycytidine (5-mdC), was markedly lower in the liver tissues of Long-Evans Cinnamon than Long-Evans Agouti rats, though no differences were observed for the levels of 5-mdC. In vitro biochemical assay showed that Cu(2+) ions could directly inhibit the activity of Tet enzymes. Together, these results suggest that aberrant copper accumulation may perturb genomic stability by elevating oxidatively induced DNA lesions, and by altering epigenetic pathways of gene regulation.

[Phytoplankton Community Structure and Water Quality Assessment in Jialing River After the Impoundment of Caojie Reservoir].

The variation of phytoplankton community and the water quality in Jialing River after the impoundment of Caojie Reservoir was studied in this paper. There were 145 species of phytoplankton under the membership of 8 divisions and 74 genera. Bacillariophyta was the first dominant division, with a total of 57 species of 23 genera, accounted for 39. 3% of total phytoplankton species, followed by Chlorophyta, with 53 species of 28 genera and accounted for 36. 6%. Only 35 species of 23 genera belonged to Euglenphyta, Cryptophyta, Pyrrophyta, Chrysophyta, and Cyanophyta. The average phytoplankton abundance was 1. 82 x 10(5)cell . L-1, and the top three taxon of most abundant were Bacillariophyta, Cryptophyta and Pyrrophyta, accounted for 39. 2%, 29. 9%, and 24. 5% of total abundance, respectively. The cell abundance in spring was significantly higher than those in other seasons. The dominant species included Aulacoseria granulata, Melosira varians, Peridiniopsis niei, Komma caudata, Cryptomonas erosa etc., indicated by the dominant index. Excluded by cluster analysis, the influence on phytoplankton had initially emerged after the impoundment of Caojie Reservoir. The reservoir area could be divided into different ecological regions longitudinally after Caojie Reservoir impoundment, which had an important impact on the phytoplankton. Meanwhile, the phytoplankton and flow velocity between upstream and downstream of the dam significantly varied. Shannon-Wiener species diversity index, Margalef species richness index and Pielous evenness index ranged 2. 06 - 3. 55, 0. 76 - 1. 90 and 0. 50 - 0. 78, respectively. The evaluation results of phytoplankton community structure showed that the eutrophic state was at medium eutrophication level, while diversity analysis results indicated light to moderate pollution.

Mass spectrometry for the assessment of the occurrence and biological consequences of DNA adducts.

Exogenous and endogenous sources of chemical species can react, directly or after metabolic activation, with DNA to yield DNA adducts. If not repaired, DNA adducts may compromise cellular functions by blocking DNA replication and/or inducing mutations. Unambiguous identification of the structures and accurate measurements of the levels of DNA adducts in cellular and tissue DNA constitute the first and important step towards understanding the biological consequences of these adducts. The advances in mass spectrometry (MS) instrumentation in the past 2-3 decades have rendered MS an important tool for structure elucidation, quantification, and revelation of the biological consequences of DNA adducts. In this review, we summarized the development of MS techniques on these fronts for DNA adduct analysis. We placed our emphasis of discussion on sample preparation, the combination of MS with gas chromatography- or liquid chromatography (LC)-based separation techniques for the quantitative measurement of DNA adducts, and the use of LC-MS along with molecular biology tools for understanding the human health consequences of DNA adducts. The applications of mass spectrometry-based DNA adduct analysis for predicting the therapeutic outcome of anti-cancer agents, for monitoring the human exposure to endogenous and environmental genotoxic agents, and for DNA repair studies were also discussed.

A simple and reliable health monitoring system for shoulder health: proposal.

BACKGROUND: The current health care system is complex and inefficient. A simple and reliable health monitoring system that can help patients perform medical self-diagnosis is seldom readily available. Because the medical system is vast and complex, it has hampered or delayed patients in seeking medical advice or treatment in a timely manner, which may potentially affect the patient's chances of recovery, especially those with severe sicknesses such as cancer, and heart disease. OBJECTIVE: The purpose of this paper is to propose a methodology in designing a simple, low cost, Internet-based health-screening platform. METHODS: This health-screening platform will enable patients to perform medical self-diagnosis over the Internet. Historical data has shown the importance of early detection to ensure patients receive proper treatment and speedy recovery. RESULTS: The platform is designed with special emphasis on the user interface. Standard Web-based user-interface design is adopted so the user feels ease to operate in a familiar Web environment. In addition, graphics such as charts and graphs are used generously to help users visualize and understand the result of the diagnostic. The system is developed using hypertext preprocessor (PHP) programming language. One important feature of this system platform is that it is built to be a stand-alone platform, which tends to have better user privacy security. The prototype system platform was developed by the National Cheng Kung University Ergonomic and Design Laboratory. CONCLUSIONS: The completed prototype of this system platform was submitted to the Taiwan Medical Institute for evaluation. The evaluation of 120 participants showed that this platform system is a highly effective tool in health-screening applications, and has great potential for improving the medical care quality for the general public.

Quantitative assessment of Tet-induced oxidation products of 5-methylcytosine in cellular and tissue DNA.

Recent studies showed that Ten-eleven translocation (Tet) family dioxygenases can oxidize 5-methyl-2'-deoxycytidine (5-mdC) in DNA to yield the 5-hydroxymethyl, 5-formyl and 5-carboxyl derivatives of 2'-deoxycytidine (5-HmdC, 5-FodC and 5-CadC). 5-HmdC in DNA may be enzymatically deaminated to yield 5-hydroxymethyl-2'-deoxyuridine (5-HmdU). After their formation at CpG dinucleotide sites, these oxidized pyrimidine nucleosides, particularly 5-FodC, 5-CadC, and 5-HmdU, may be cleaved from DNA by thymine DNA glycosylase, and subsequent action of base-excision repair machinery restores unmethylated cytosine. These processes are proposed to be important in active DNA cytosine demethylation in mammals. Here we used a reversed-phase HPLC coupled with tandem mass spectrometry (LC-MS/MS/MS) method, along with the use of stable isotope-labeled standards, for accurate measurements of 5-HmdC, 5-FodC, 5-CadC and 5-HmdU in genomic DNA of cultured human cells and multiple mammalian tissues. We found that overexpression of the catalytic domain of human Tet1 led to marked increases in the levels of 5-HmdC, 5-FodC and 5-CadC, but only a modest increase in 5-HmdU, in genomic DNA of HEK293T cells. Moreover, 5-HmdC is present at a level that is approximately 2-3 and 3-4 orders of magnitude greater than 5-FodC and 5-CadC, respectively, and 35-400 times greater than 5-HmdU in the mouse brain and skin, and human brain. The robust analytical method built a solid foundation for dissecting the molecular mechanisms of active cytosine demethylation, for measuring these 5-mdC derivatives and assessing their involvement in epigenetic regulation in other organisms and for examining whether these 5-mdC derivatives can be used as biomarkers for human diseases.