Pregnancy exposure to PM2.5 from wildland fire smoke and preterm birth in California

BACKGROUND

Wildfires in the Western United States are a growing and significant source of air pollution that is eroding decades of progress in air pollution reduction. The effects on preterm birth during critical periods of pregnancy are unknown.

METHODS

We assessed associations between prenatal exposure to wildland fire smoke and risk of preterm birth (gestational age < 37 weeks). We assigned smoke exposure to geocoded residence at birth for all live singleton births in California conceived 2007-2018, using weekly average concentrations of particulate matter ≤ 2.5 µm (PM2.5) attributable to wildland fires from United States Environmental Protection Agency's Community Multiscale Air Quality Model. Logistic regression yielded odds ratio (OR) for preterm birth in relation to increases in average exposure across the whole pregnancy, each trimester, and each week of pregnancy. Models adjusted for season, age, education, race/ethnicity, medical insurance, and smoking of the birthing parent.

RESULTS

For the 5,155,026 births, higher wildland fire PM2.5 exposure averaged across pregnancy, or any trimester, was associated with higher odds of preterm birth. The OR for an increase of 1 µg/m3 of average wildland fire PM2.5 during pregnancy was 1.013 (95 % CI:1.008,1.017). Wildland fire PM2.5 during most weeks of pregnancy was associated with higher odds. Strongest estimates were observed in weeks in the second and third trimesters. A 10 µg/m3 increase in average wildland fire PM2·5 in gestational week 23 was associated with OR = 1.034; 95 % CI: 1.019, 1.049 for preterm birth.

CONCLUSIONS

Preterm birth is sensitive to wildland fire PM2.5; therefore, we must reduce exposure during pregnancy.

Empirical nitrogen and sulfur critical loads of U.S. tree species and their uncertainties with machine learning

Critical loads (CLs) of atmospheric deposition for nitrogen (N) and sulfur (S) are used to support decision making related to air regulation and land management. Frequently, CLs are calculated using empirical methods, and the certainty of the results depends on accurate representation of underlying ecological processes. Machine learning (ML) models perform well in empirical modeling of processes with non-linear characteristics and significant variable interactions. We used bootstrap ensemble ML methods to develop CL estimates and assess uncertainties of CLs for the growth and survival of 108 tree species in the conterminous United States. We trained ML models to predict tree growth and survival and characterize the relationship between deposition and tree species response. Using four statistical methods, we quantified the uncertainty of CLs in 95 % confidence intervals (CI). At the lower bound of the CL uncertainty estimate, 80 % or more of tree species have been impacted by nitrogen deposition exceeding a CL for tree survival over >50 % of the species range, while at the upper bound the percentage is much lower (<20 % of tree species impacted across >60 % of the species range). Our analysis shows that bootstrap ensemble ML can be effectively used to quantify critical loads and their uncertainties. The range of the uncertainty we calculated is sufficiently large to warrant consideration in management and regulatory decision making with respect to atmospheric deposition.

[Lung transplantation for pulmonary alveolar proteinosis: a case report and literature review]

Objective: To observe the efficacy of lung transplantation for pulmonary alveolar proteinosis (PAP) patients and to improve the understanding of the therapy. Methods: The clinical data of a patient with autoimmune PAP treated with sequential homogenous bilateral lung transplantation were described and the literatures were reviewed. Results: This 55-year-old female patient was diagnosed with autoimmune PAP and had been treated with whole lung lavage for 19 times, but only achieved short-term symptomatic relief after each operation. Inhalation of granulocyte macrophage colony stimulating factor occurred allergic reactions. Lung transplantation was performed on February 15, 2022, and a significant improvement in oxygenation and clinical symptoms were observed. The patient remained stable during follow-up. Conclusion: Treatment with lung transplantation is safe and effective for end-stage patients with PAP in the early phase, but the long-term effect remains to be observed.

Daily Associations of Air Pollution and Pediatric Asthma Risk Using the Biomedical REAI-Time Health Evaluation (BREATHE) Kit

Background: Exposure to air pollution is associated with acute pediatric asthma exacerbations, including reduced lung function, rescue medication usage, and increased symptoms; however, most studies are limited in investigating longitudinal changes in these acute effects. This study aims to investigate the effects of daily air pollution exposure on acute pediatric asthma exacerbation risk using a repeated-measures design. Methods: We conducted a panel study of 40 children aged 8−16 years with moderate-to-severe asthma. We deployed the Biomedical REAI-Time Health Evaluation (BREATHE) Kit developed in the Los Angeles PRISMS Center to continuously monitor personal exposure to particulate matter of aerodynamic diameter < 2.5 µm (PM2.5), relative humidity and temperature, geolocation (GPS), and asthma outcomes including lung function, medication use, and symptoms for 14 days. Hourly ambient (PM2.5, nitrogen dioxide (NO2), ozone (O3)) and traffic-related (nitrogen oxides (NOx) and PM2.5) air pollution exposures were modeled based on location. We used mixed-effects models to examine the association of same day and lagged (up to 2 days) exposures with daily changes in % predicted forced expiratory volume in 1 s (FEV1) and % predicted peak expiratory flow (PEF), count of rescue inhaler puffs, and symptoms. Results: Participants were on average 12.0 years old (range: 8.4−16.8) with mean (SD) morning %predicted FEV1 of 67.9% (17.3%) and PEF of 69.1% (18.4%) and 1.4 (3.5) puffs per day of rescue inhaler use. Participants reported chest tightness, wheeze, trouble breathing, and cough symptoms on 36.4%, 17.5%, 32.3%, and 42.9%, respectively (n = 217 person-days). One SD increase in previous day O3 exposure was associated with reduced morning (beta [95% CI]: −4.11 [−6.86, −1.36]), evening (−2.65 [−5.19, −0.10]) and daily average %predicted FEV1 (−3.45 [−6.42, −0.47]). Daily (lag 0) exposure to traffic-related PM2.5 exposure was associated with reduced morning %predicted PEF (−3.97 [−7.69, −0.26]) and greater odds of “feeling scared of trouble breathing” symptom (odds ratio [95% CI]: 1.83 [1.03, 3.24]). Exposure to ambient O3, NOx, and NO was significantly associated with increased rescue inhaler use (rate ratio [95% CI]: O3 1.52 [1.02, 2.27], NOx 1.61 [1.23, 2.11], NO 1.80 [1.37, 2.35]). Conclusions: We found significant associations of air pollution exposure with lung function, rescue inhaler use, and “feeling scared of trouble breathing.” Our study demonstrates the potential of informatics and wearable sensor technologies at collecting highly resolved, contextual, and personal exposure data for understanding acute pediatric asthma triggers.

[Immunogenicity and safety of a boost dose of measles, mumps, and rubella combined vaccine for 4-6 years old children]

Objective: To investigate the immunogenicity and safety of a boost dose of measles, mumps, and rubella combined vaccine (MMR) for children 4 to 6 years old. Methods: Children, aged 4 to 6 years old, had vaccinated with 1 dose of measles and rubella combined vaccine(MR) at the age of 8 months and 1 dose of MMR vaccine at 18-months, were recruited in Shanxi, Inner Mongolia, and Beijing, respectively. All children were assigned into 4, 5 and 6-year-old group. The children who met inclusion and exclusion criteria were vaccinated with 1 dose MMR vaccine, and were collected blood samples before vaccination and 35 to 42 d after the vaccination. During the study period, adverse events were collected at 30 min, 1 d, 2 d, 3 d, 4-12 d, and 13 to 42 days after vaccination. Serum was tested for IgG antibodies against measles, mumps and rubella. Geometric mean concentrations (GMC) of measles, mumps, and rubella antibodies were compared among groups by analysis of variance or non-parametric test. Seropositive rates and adverse event rates were compared among groups by Chi-square test or Fisher exact test. Results: A total of 500 children were included in immunogenicity analysis and 535 children were included in safety analysis. The overall adverse event rate was 20.37%, the most of severity for adverse events was mild. The rates of local and systemic adverse events were 0.37% and 20.00%, respectively. Symptoms of local adverse events were redness. The main systemic adverse events were fever, followed by cough, rash and runny nose. Received a dose of MMR vaccine for booster immunization, the seropositive rates of measles antibody, mumps antibody and rubella antibody were above 99% for all 3 age groups, and there was no significant difference between groups. There were significant differences in mumps antibody GMC among groups (P=0.042), but no significant differences in measles and rubella antibodies GMC. Conclusion: The immunogenicity and safety of a boosted MMR vaccintion in children aged 4, 5 and 6 years were all similar good.

Air quality and source apportionment modeling of year 2017 ozone episodes in Albuquerque/Bernalillo County, New Mexico

Albuquerque/Bernalillo County, New Mexico, is currently in attainment of the 2015 National Ambient Air Quality Standard (NAAQS) for ozone (70 ppb), but its ozone design values have increased in recent years. Air quality and source apportionment modeling with the Comprehensive Air Quality Model with Extensions (CAMx) was conducted for Albuquerque/Bernalillo County to develop a refined understanding of ozone source apportionment in the region, estimate ozone concentrations in the year 2025 based on projected changes in anthropogenic emissions, and evaluate the sensitivity of future ozone concentrations to various changes in local and non-local emissions. The study focused on two ozone episodes during June and July 2017 when 8-hr average ozone concentrations were greater than 70 ppb. Based on the modeling results, ozone during the June 2017 episode was found to be driven largely by contributions from non-local and regional emissions, whereas ozone during the July 2017 episode was driven more strongly by local emissions from within Albuquerque/Bernalillo County. On high ozone days, anthropogenic emissions from within Albuquerque/Bernalillo County contributed between 8% and 19% (6-14 ppb) of total ozone. Half of this local ozone contribution was from on-road mobile sources. Fire emissions contributed as much as 2 ppb of ozone on a given day. Contributions from large power plants in New Mexico were as large as 1 ppb on a given day but less than 0.5 ppb on most days. Modeled ozone concentrations in Albuquerque/Bernalillo County were also sensitive to emissions from oil and gas emissions in New Mexico. If projected emission reductions by 2025 materialize, these reductions could reduce future peak 8-hr average ozone concentrations by as much as 3-4% compared to 2017 values. Implications: The results of this study have important implications for air quality management in Albuquerque/Bernalillo County. Ozone in Albuquerque/Bernalillo County is the result of local and non-local emissions, is impacted by wildfires, and is sensitive to statewide oil and gas emissions. The magnitude of modeled contributions from anthropogenic emissions within Albuquerque/Bernalillo County is strongly influenced by meteorological conditions, transport pathways, and the presence of wildfire. This modeling is important for understanding the potential effectiveness of local emission controls in Albuquerque/Bernalillo County, and can serve as a basis for testing future regional and local emission control options.

Fine-Scale Modeling of Individual Exposures to Ambient PM2.5, EC, NOx, CO for the Coronary Artery Disease and Environmental Exposure (CADEE) Study

Air pollution epidemiological studies often use outdoor concentrations from central-site monitors as exposure surrogates, which can induce measurement error. The goal of this study was to improve exposure assessments of ambient fine particulate matter (PM2.5), elemental carbon (EC), nitrogen oxides (NOx), and carbon monoxide (CO) for a repeated measurements study with 15 individuals with coronary artery disease in central North Carolina called the Coronary Artery Disease and Environmental Exposure (CADEE) Study. We developed a fine-scale exposure modeling approach to determine five tiers of individual-level exposure metrics for PM2.5, EC, NOx, CO using outdoor concentrations, on-road vehicle emissions, weather, home building characteristics, time-locations, and time-activities. We linked an urban-scale air quality model, residential air exchange rate model, building infiltration model, global positioning system (GPS)-based microenvironment model, and accelerometer-based inhaled ventilation model to determine residential outdoor concentrations (Cout_home, Tier 1), residential indoor concentrations (Cin_home, Tier 2), personal outdoor concentrations (Cout_personal, Tier 3), exposures (E, Tier 4), and inhaled doses (D, Tier 5). We applied the fine-scale exposure model to determine daily 24-h average PM2.5, EC, NOx, CO exposure metrics (Tiers 1-5) for 720 participant-days across the 25 months of CADEE. Daily modeled metrics showed considerable temporal and home-to-home variability of Cout_home and Cin_home (Tiers 1-2) and person-to-person variability of Cout_personal, E, and D (Tiers 3-5). Our study demonstrates the ability to apply an urban-scale air quality model with an individual-level exposure model to determine multiple tiers of exposure metrics for an epidemiological study, in support of improving health risk assessments.

[Characteristics of cardiovascular health of children and adolescents aged 6-16 years in Beijing during 2017-2018]

Objective: To describe the status of cardiovascular health (CVH) of children and adolescents aged 6-16 years in Beijing during 2017-2018. Methods: The school-based Cardiovascular and Bone Health Promotion Program(SCVBH) was conducted from November 2017 to January 2018. 15 391 children and adolescents aged 6-16 years were selected from grade 1 to 4 in 8 primary schools, grade 1 in 21 middle schools and senior grade 1 in one twelve-year education school in Dongcheng, Fangshan, Miyun and Haidian Districts of Beijing by using a cluster sampling method. Seven cardiovascular health indicators, including smoking, body mass index, dietary intake, physical activity, blood pressure, blood glucose, and total cholesterol, were categorized as poor, intermediate, and ideal according to American Heart Association (AHA) criteria. The status of CVH was evaluated according to the criteria of the ideal CVH related behaviors and factors defined by AHA. Results: The proportion of children and adolescents with an ideal smoking, dietary intake and physical activity indicators reached 99.2%(4 982/15 108), 19.7%(2 921/14 805), 17.8% (2 499/14 056), respectively. The proportion of children and adolescents with 7 and 4-5 ideal cardiovascular health indicators was 1.7%(209/12 560) and 65.1%(8 176/12 560). The proportion of children and adolescents with 4-7 ideal cardiovascular health indicators, 2-4 ideal health behavior indicators and 2-3 ideal health factors was significantly higher in urban than that in rural all P values<0.001. The proportion of females with 4-7 ideal cardiovascular health indicators, 2-4 ideal health behavior indicators and 2-3 ideal health factors was significantly higher than that in males (all P values<0.001). Conclusion: The prevalence of ideal cardiovascular health of children and adolescents aged 6-16 years in Beijing during 2017-2018 was very low, particularly for healthy dietary intake and physical activity. Effective public health interventions should be implemented to improve the status of cardiovascular health of them.

[The association between body fat distribution and calcaneal bone mineral density in children and adolescents aged 6-16 years in Beijing]

Objective: To understand the association between body fat distribution and calcaneal bone mineral density (BMD) in children and adolescents aged 6-16 years in Beijing. Methods: Children and adolescents were selected in 30 schools (8 primary schools, 21 middle schools and one 12-year education school) from Dongcheng, Tongzhou, Fangshan and Miyun districts of Beijing by using a stratified cluster sampling method from November 2017 to January 2018. A total of 15 030 students in grade 1 to 4 of primary school, grade 1 of junior and senior middle school were enrolled after excluding subjects who were not able to participate into this study due to trauma or other uncomfortable physical conditions or with missing key values or with diabetes and kidney diseases. Questionnaire survey, body composition and calcaneus bone mineral density were conducted. The relation of fat mass percentage (FMP), trunk to total fat ratio (TrTFR), trunk to limb fat ratio (TrLFR), limb to total fat ratio (LTFR) and viscera to total fat ratio (VTFR) with calcaneus BMD were assessed using the multivariate linear regression models after adjusting for possible confounding effects. The central fat distribution types were divided into 4 groups including type 1: both trunk fat and visceral fat greater than the sex-and age-specific internal P(75); type 2: barely trunk fat greater than P(75); type 3: barely visceral fat greater than P(75); type 4: both trunk fat and visceral fat greater than P(75). The central fat distribution types were included into the model in the form of dummy variables to analyze its relationship with calcaneal BMD. The sex-and age-specific z-scores of fat distribution indicators and BMD were calculated. Results: A total of 15 030 participants aged (11.4±3.3) years (50.2% boys) were involved in the analysis. In both genders, after adjusting for age, height, lean mass index, smoking, drinking, physical activity, milk intake, vitamin D and calcium supplementation, FMP, TrTFR, TrLFR and VTFR were negatively correlated with calcaneal BMD (all P value<0.05), while LTFR was positively associated with calcaneal BMD (all P values<0.05). Compared to the central fat distribution type 1, the regression coefficients (95% CI) of type 2, 3 and 4 were -0.253 (-0.418, -0.087), -0.385 (-0.567, -0.204) and -0.428 (-0.487, -0.369) in boys, respectively; the regression coefficients (95% CI) of type 3 and 4 were -0.158 (-0.301, -0.015) and -0.226 (-0.290, -0.163), respectively. Conclusion: Body fat distribution and central fat distribution in children and adolescents were correlated with calcaneus bone mineral density.

[The association between blood lipids and calcaneus bone mineral density in children and adolescents aged 6-16 years in Beijing]

Objective: To investigate the association between blood lipid and calcaneus bone mineral density (BMD) in children and adolescents aged 6-16 years in Beijing. Methods: Children and adolescents were selected in 30 schools (8 primary schools, 21 middle schools and one 12-year education school) from Dongcheng, Tongzhou, Fangshan and Miyun districts of Beijing by using a stratified cluster sampling method from November 2017 to January 2018. A total of 14 303 students in grade 1 to 4 of primary school, grade 1 of junior and senior middle school were enrolled after excluding subjects who were not able to participate into this study due to trauma or other uncomfortable physical conditions or with missing key values or with diabetes and kidney diseases. Questionnaire survey, blood lipid and calcaneus BMD were conducted. Multivariate linear regression was applied to quantify the association between calcaneal BMD as a dependent variable and blood lipid level as an independent variable after adjusting for the potential confounding factors. Furthermore, quantile regression was used to analyze the association between blood lipid level and different percentiles (P(25), P(50) and P(75)) of ultrasonic velocity values of bone mineral density, and parallel test was conducted for regression coefficients of different percentiles. Results: A total of 14 303 participants aged (11.4±3.3) years (49.9% boys) were involved in the analysis. The mean age of 14 303 participants was (11.0±3.3) years. 7 142 boys accounted for 49.9%. The mean±SD of calcaneal BMD, total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), and high density lipoprotein-cholesterol (HDL-C) were (1 540.9±33.8) m/s, (3.90±0.76), (2.18±0.62), and (1.40±0.32) mmol/L, respectively. The P(5)0 (P(25), P(75)) of triglyceride (TG) was 0.69 (0.49-0.94) mmol/L. After the adjustment of age, height, smoking, drinking, vitamin D and calcium supplementation, dairy intake, physical activity, FMI, and MMI, a significantly inverse association (P<0.05) between TG level and calcaneus BMD was observed in both genders, which the regression coefficients (95%CI) in boys and girls were -0.064 (-0.085, -0.044) and -0.073 (-0.094, -0.053), respectively. Conclusion: The level of BMD was associated with TG in boys and girls. Therefore, it is important to prevent children from hypertriglyceridemia for the bone health promotion.

[The baseline characteristics of School-based Cardiovascular and Bone Health Promotion Program in Beijing]

Objective: To describe the baseline characteristics of School-based Cardiovascular and Bone Health Promotion Program(SCVBH) in Beijing. Methods: Children and adolescents were selected in 30 schools (8 primary schools, 21 middle schools and one 12-year education school) from Dongcheng, Tongzhou, Fangshan and Miyun districts of Beijing by using a stratified cluster sampling method. 15 391 students in grade 1 to 4 from primary schools, grade 1 from junior and senior high schools were enrolled in the investigation with an exclusion of students who were not able to participate due to trauma or other uncomfortable physical conditions. The baseline survey including a questionnaire survey, physical examination and blood biochemical test was conducted from September 2017 to January 2018. Obesity, blood pressure, fasting blood glucose, lipid, bone density and grip were evaluated. Results: The prevalence of obesity, hypertension, hyperglycemia (impaired fasting glucose and diabetes), dyslipidemia, lower bone density were 22.3%(3 394), 14.8%(2 248), 10.4%(1 490), 20.3%(2 919) and 2.1%(316) in total respectively, and 27.2%(2 081), 16.3%(1 244), 12.8%(922), 22.2%(1 595) and 1.2%(94) for boys, 17.3%(1 313), 13.3% (1 004), 7.9%(568), 18.4%(1 324) and 2.9%(229) for girls. Boys had higher prevalence of obesity, hypertension, hyperglycemia, and dyslipidemia and lower prevalence of low bone density than girls (all P values <0.05) The mean of body mass index, systolic blood pressure, fasting plasma glucose and grip of boys were significantly higher than that of girls (all P values <0.05).The mean of body mass index, systolic blood pressure, fasting plasma glucose and grip of boys were significantly higher than that of girls (all P values <0.05), the mean of fat mass percentage, total cholesterol, triglyceride, high density lipoprotein-cholesterol and low density lipoprotein-cholesterol of boys were significantly lower than those of girls (all P values <0.05). Conclusion: The prevalence of risk factors of chronic cardiovascular disease was high and the low bone density was appearing in children and adolescents in this study. The promotion of cardiovascular and bone health should be implemented in children and adolescents.

Finely Resolved On-Road PM2.5 and Estimated Premature Mortality in Central North Carolina

To quantify the on-road PM_2.5 -related premature mortality at a national scale, previous approaches to estimate concentrations at a 12-km × 12-km or larger grid cell resolution may not fully characterize concentration hotspots that occur near roadways and thus the areas of highest risk. Spatially resolved concentration estimates from on-road emissions to capture these hotspots may improve characterization of the associated risk, but are rarely used for estimating premature mortality. In this study, we compared the on-road PM_2.5 -related premature mortality in central North Carolina with two different concentration estimation approaches-(i) using the Community Multiscale Air Quality (CMAQ) model to model concentration at a coarser resolution of a 36-km × 36-km grid resolution, and (ii) using a hybrid of a Gaussian dispersion model, CMAQ, and a space-time interpolation technique to provide annual average PM_2.5 concentrations at a Census-block level (∼105,000 Census blocks). The hybrid modeling approach estimated 24% more on-road PM_2.5 -related premature mortality than CMAQ. The major difference is from the primary on-road PM_2.5 where the hybrid approach estimated 2.5 times more primary on-road PM_2.5 -related premature mortality than CMAQ due to predicted exposure hotspots near roadways that coincide with high population areas. The results show that 72% of primary on-road PM_2.5 premature mortality occurs within 1,000 m from roadways where 50% of the total population resides, highlighting the importance to characterize near-road primary PM_2.5 and suggesting that previous studies may have underestimated premature mortality due to PM_2.5 from traffic-related emissions.

Impact of virtual reality games on psychological well-being and upper limb performance in adults with physical disabilities: A pilot study

INTRODUCTION

There is limited information regarding the effects of interactive virtual reality (VR) games on psychological and physical well-being among adults with physical disabilities. We aimed to examine the impact of VR games on psychological well-being, upper limb motor function and reaction time in adults with physical disabilities.

METHODS

Fifteen participants completed the intervention using Wii VR games in this pilot study. Depressive, Anxiety and Stress Scales (DASS) and Capabilities of Upper Extremity (CUE) questionnaires were used to measure psychological well-being and upper limb motor function respectively. Upper limb reaction time was measured using reaction time test.

RESULTS

Results showed that there was a significant difference (p<0.05) in DASS questionnaire and average reaction time score after intervention.

CONCLUSION

There is a potential for using interactive VR games as an exercise tool to improve psychological wellbeing and upper limb reaction time among adults with disabilities.

Liver and Kidney on Chips: Microphysiological Models to Understand Transporter Function

Because of complex cellular microenvironments of both the liver and kidneys, accurate modeling of transport function has remained a challenge, leaving a dire need for models that can faithfully recapitulate both the architecture and cell-cell interactions observed in vivo. The study of hepatic and renal transport function is a fundamental component of understanding the metabolic fate of drugs and xenobiotics; however, there are few in vitro systems conducive for these types of studies. For both the hepatic and renal systems, we provide an overview of the location and function of the most significant phase I/II/III (transporter) of enzymes, and then review current in vitro systems for the suitability of a transporter function study and provide details on microphysiological systems that lead the field in these investigations. Microphysiological modeling of the liver and kidneys using "organ-on-a-chip" technologies is rapidly advancing in transport function assessment and has emerged as a promising method to evaluate drug and xenobiotic metabolism. Future directions for the field are also discussed along with technical challenges encountered in complex multiple-organs-on-chips development.

Effects of embryonic ethanol exposure at low doses on neuronal development, voluntary ethanol consumption and related behaviors in larval and adult zebrafish: Role of hypothalamic orexigenic peptides

Embryonic exposure to ethanol is known to affect neurochemical systems in rodents and increase alcohol drinking and related behaviors in humans and rodents. With zebrafish emerging as a powerful tool for uncovering neural mechanisms of numerous diseases and exhibiting similarities to rodents, the present report building on our rat studies examined in zebrafish the effects of embryonic ethanol exposure on hypothalamic neurogenesis, expression of orexigenic neuropeptides, and voluntary ethanol consumption and locomotor behaviors in larval and adult zebrafish, and also effects of central neuropeptide injections on these behaviors affected by ethanol. At 24h post-fertilization, zebrafish embryos were exposed for 2h to ethanol, at low concentrations of 0.25% and 0.5%, in the tank water. Embryonic ethanol compared to control dose-dependently increased hypothalamic neurogenesis and the proliferation and expression of the orexigenic peptides, galanin (GAL) and orexin (OX), in the anterior hypothalamus. These changes in hypothalamic peptide neurons were accompanied by an increase in voluntary consumption of 10% ethanol-gelatin and in novelty-induced locomotor and exploratory behavior in adult zebrafish and locomotor activity in larvae. After intracerebroventricular injection, these peptides compared to vehicle had specific effects on these behaviors altered by ethanol, with GAL stimulating consumption of 10% ethanol-gelatin more than plain gelatin food and OX stimulating novelty-induced locomotor behavior while increasing intake of food and ethanol equally. These results, similar to those obtained in rats, suggest that the ethanol-induced increase in genesis and expression of these hypothalamic peptide neurons contribute to the behavioral changes induced by embryonic exposure to ethanol.

A modeling framework for characterizing near-road air pollutant concentration at community scales

In this study, we combine information from transportation network, traffic emissions, and dispersion model to develop a framework to inform exposure estimates for traffic-related air pollutants (TRAPs) with a high spatial resolution. A Research LINE source dispersion model (R-LINE) is used to model multiple TRAPs from roadways at Census-block level for two U.S. regions. We used a novel Space/Time Ordinary Kriging (STOK) approach that uses data from monitoring networks to provide urban background concentrations. To reduce the computational burden, we developed and applied the METeorologically-weighted Averaging for Risk and Exposure (METARE) approach with R-LINE, where a set of selected meteorological data and annual average daily traffic (AADT) are used to obtain annual averages. Compared with explicit modeling, using METARE reduces CPU-time by 88-fold (46.8h versus 32min), while still retaining accuracy of exposure estimates. We show two examples in the Piedmont region in North Carolina (~105,000 receptors) and Portland, Maine (~7000 receptors) to characterize near-road air quality. Concentrations for NOx, PM2.5, and benzene in Portland drop by over 40% within 200m away from the roadway. The concentration drop in North Carolina is less than that in Portland, as previously shown in an observation-based study, showing the robustness of our approach. Heavy-duty diesel vehicles (HDDV) contribute over 55% of NOx and PM2.5 near interstate highways, while light-duty gasoline vehicles (LDGV) contribute over 50% of benzene to urban areas where multiple roadways intersect. Normalized mean error (NME) between explicit modeling and METARE in Portland ranges from 12.6 to 14.5% and normalized mean bias (NMB) ranges from -12.9 to -11.2%. When considering a static emission rate (i.e. the emission does not have temporal variability), both NME and NMB improved (10.5% and -9.5%). Modeled concentrations in Detroit, Michigan at an array of near-road monitors are within a factor of 2 of observed values for CO but not NOx.

Evaluation of FRNA coliphages as indicators of human enteric viruses in a tropical urban freshwater catchment

This study aimed to evaluate the relationship between FRNA coliphages (FRNA GI to GIV) and human enteric viruses (human adenoviruses, HAdV, astroviruses, AstV, noroviruses, NoV, and rotaviruses, RoV) in a tropical urban freshwater catchment. Positive associations between human-specific coliphages and human viral pathogens substantiate their use as viral indicators and in microbial source tracking. Reverse transcription qPCR was used to measure the concentrations of viruses and FRNA coliphages in concentrated water samples. Environmental water samples were also analyzed for male-specific (F+) and somatic (Som) coliphages using plaque assay. The most abundant enteric virus was NoV (55%) followed by HAdV (33%), RoV (33%), and AstV (23%), while the most abundant FRNA genogroup was GI (85%) followed by GII (48%), GIV (8%) and GIII (7%). Concentrations of human-specific coliphages FRNA GII were positively correlated with NoV, HAdV, RoV, AstV, F+ and Som (τ = 0.5 to 0.3, P < 0.05) while concentrations of animal-specific coliphages FRNA GI were negatively correlated with HAdV and RoV (τ = -0.2, P < 0.05). This study demonstrates statistical relationships between human-specific coliphages and a suite of human enteric viruses in the environment.

Microporous Ti implant compact coated with hydroxyapatite produced by electro-discharge-sintering and electrostatic-spray-deposition

A single pulse of 1.5 kJ/0.7 g of atomized spherical Ti powder from 300 μF capacitor was applied to produce the porous-surfaced Ti implant compact by electro-discharge-sintering (EDS). A solid core surrounded by porous layer was self-consolidated by a discharge in the middle of the compact in 122 μsec. Average pore size, porosity, and compressive yield strength of EDS Ti compact were estimated to be about 68.2 μm, 25.5%, and 266.4 MPa, respectively. Coatings with hydroxyapatite (HAp) on the Ti compact were conducted by electrostatic-spray-deposition (ESD) method. As-deposited HAp coating was in the form of porous structure and consisted of HAp particles which were uniformly distributed on the Ti porous structure. By heat-treatment at 700 degrees C, HAp particles were agglomerated each other and melted to form a highly smooth and homogeneous HAp thin film consisted of equiaxed nano-scaled grains. Porous-surfaced Ti implant compacts coated with highly crystalline apatite phase were successfully obtained by using the EDS and ESD techniques.

Predictors of bloodstream infection associated with permanently implantable venous port in solid cancer patients

BACKGROUND

The purpose of this study is to characterize the risk factors of bloodstream infection (BSI) associated with the use of permanent implantable venous ports (Port-A) in solid cancer patients.

METHODS

Solid cancer patients implanted with a Port-A were prospectively observed for the occurrence of Port-A-associated BSI (PABSI), defined as BSI without other identifiable infection foci. A PABSI risk score was developed using the Cox proportional hazards model.

RESULTS

A total of 415 patients were registered; 88 PABSI episodes occurred in 58 patients (incidence1.05 per 1000 catheter-days). All but one patient had stage IV cancer. Independent predictors of PABSI occurrence included neutropenia, total parenteral nutrition (TPN), chronic steroid use, invasive procedures, postoperative antibiotics, and preoperative antibiotics. A PABSI risk score with a cut-off value of 0 (sensitivity 88.5%, specificity 64.3%) was defined for stage IV cancer patients as follows: neutropenia, +1.350; TPN, +1.256; chronic steroid use, +1.947; preoperative antibiotics, -0.970; postoperative antibiotics, +0.959; and invasive procedures, +1.098. The median PABSI-free survival was 4.47 months for patients with scores ≥ 0 but not reached for patients with scores <0 (P < 0.0001).

CONCLUSION

The PABSI risk score can assist in identifying high-risk solid cancer patients and may assist in designing future preventive strategies.

Laser Vaporization/Ionization Interface for Capillary Electrophoresis-Time-of-Flight Mass Spectrometry

Mass spectrometry (MS) is usually coupled on-line with capillary electrophoresis (CE) to analyze biomolecules by using electrospray ionization or continuous-flow fast-atom bombardment. We present a new design for laser vaporization/ionization time-of-flight mass spectrometry. CE, with its low flow rate (<1 μL/min), is highly compatible with MS, even if the total column effluent is introduced directly. A UV laser is used to vaporize and ionize the solution eluting from the column. There is no need to have a makeup solvent. Using this system, we have analyzed a group of amines and peptides. The concentration detection limit of serotonin is in the 10(-)(7) M level. The separation and identification of an amine mixture by CE/MS demonstrates the complementary nature of the information.

Pharmacokinetics of muraglitazar (BMS-298585), a dual peroxisome proliferator-activated receptors (PPAR) α and γ activator, in mice, rats, dogs, and monkeys

The pharmacokinetic parameters of muraglitazar, a novel dual-activator of the peroxisome proliferator-activated receptors (PPAR) alpha and gamma, were determined in mice, rats, dogs, and monkeys after intravenous and oral administration. In the mouse, rat, and monkey the absolute oral bioavailability of muraglitazar ranged from 64 to 88%, and in the dog oral bioavailability was approximately 18%. The systemic clearance values of muraglitazar in the mouse, rat, dog, and cynomolgus monkey were 1.2, 3.0, 12.3 and 1.2 ml min-1 kg-1, respectively. The terminal elimination half-life was 2.4 h in dogs and 7.3 h in rats. The terminal elimination half-life could not be determined in the mouse and monkey because the sampling interval did not adequately cover the terminal elimination phase. Muraglitazar appears to be distributed outside of the vasculature, with the steady-state volume of distribution being approximately twofold that of the vascular volume in rats and dogs, and approximately twofold that of the total body water in mice. The systemic plasma clearance of muraglitazar in humans was predicted to be approximately 12-14 ml min-1 kg-1 based on allometry or by scaling of in vitro clearance parameters. Overall, the pharmacokinetic parameters of muraglitazar in preclinical species were acceptable for the advancement of the compound as a clinical candidate.

MODULATION OF MDR-1 GENE BY MIF AND GSTpi WITH DRUG RESISTANCE GENERATION IN HORMONE INDEPENDENT PROSTATE CANCER

The expression of MIF and GSTpi were upregulated in prostate cancer cells with mulitdrug resistant phenotype. The aim of this study is to determine the relationship between these genes and multidrug resistance (mdr-1) gene in acquired multidrug resistance of prostate cancer. The expression of MIF, GSTpi and gp-170 in multidrug resistant (MDR) subline or native cells were determined using flow cytometry and western blotting. The mRNA level of various genes was analyzed with RT-PCR method. The chemosensitivity of tumor cells and stable transfectants to paclitaxel was measured using MTT (tetrazolium bromide) assay. The protein levels of MIF, GSTpi and gp-170 increased in MDR sublines of prostate cancer when compared with their parental cells. The MIF and GSTpi stable transfectants expressed higher MIF and GSTpi protein levels than their parental cells in western blotting analysis, respectively. The expression of mdr-1 gene and the production of pg-170 were also increased in either MIF or GSTpi stable transfectants when compared with vector control by using RT-PCR and flow cytometric analysis. The MTT results demonstrated that the increased chemoresistance was correlated with the increased production of gp-170 protein in either MIF or GSTpi transfectants. The upregulation of MIF and GSTpi during the development of acquired drug resistance of hormone independent prostate cancer may simultaneously and partially modulate the activation of gp-170.

Development of LiF:Mg,Cu,Si TL material (new KLT-300) with a low-residual signal and high-thermal stability

LiF-based thermoluminescence (TL) materials have been widely used for radiation dosimetry due to their attractive features. LiF:Mg,Cu,P is one of the most sensitive tissue-equivalent TL materials, approximately 40 times more sensitive than LiF:Mg,Ti (TLD-100), but it has two main drawbacks: a thermal loss of the TL sensitivity when annealed at temperatures>240 degrees C, and a relatively high-residual signal. Recently, LiF:Mg,Cu,Na,Si TL material was developed to overcome these drawbacks at the Korea Atomic Energy Research Institute, but it provided only marginal improvements in reducing the residual signal. The newly developed LiF:Mg,Cu,Si TL material has a significantly lower residual signal and a better stability to thermal treatments. In this article, the preparation method and some dosimetric properties (sensitivity and residual signal) of the new LiF:Mg,Cu,Si TL material are presented. At the end of the preparation procedures, a dual-step annealing method is introduced and this has proved as a very efficient method to reduce the high-temperature peak and is the cause of residual signal. Therefore, the high-temperature peak in the glow curve was significantly reduced. The sensitivity is approximately 20 times higher than that of TLD-100 and the residual signal was estimated to be approximately 0.04%.

Healthy-side dominance of middle- and long-latency neuromagnetic fields in idiopathic sudden sensorineural hearing loss

Any lesion along the neural axis may induce a subsequent functional reorganization at the level above. The present study used magnetoencephalography to investigate auditory-evoked magnetic fields [a component of the middle-latency auditory evoked fields peaking at approximately 50 ms (P50m) and a component of the long-latency auditory evoked fields peaking at approximately 100 ms (N100m)] on stimulation of both healthy and affected ears in patients with acute unilateral idiopathic sudden sensorineural hearing loss (ISSNHL) of moderate degree in order to elucidate the functional plasticity of the auditory system. Sixteen right-handed, previously untreated adult patients with acute unilateral left (n = 8) or right (n = 8) ISSNHL of moderate degree were studied. Sixteen right-handed healthy volunteers with normal hearing served as control. Auditory neuromagnetic responses, measured by a whole-head 306-channel neuromagnetometer, were detected by monaural tone stimulation applied to affected and healthy ears, respectively, in different sessions. Intragroup and intergroup interhemispheric differences of peak dipole strengths and latencies of P50m and N100m, respectively, to monaural tones were evaluated. Healthy-side amplitude dominance of both P50m and N100m was found in ISSNHL, i.e. contralateral dominance was preserved on affected-ear stimulation but ipsilateral dominance was seen on healthy-ear stimulation. The phenomena could be attributed to the combined contralateral attenuation and ipsilateral enhancement of P50m and N100m activity in response to healthy-ear stimulation. Our findings confirmed that functional modulation can occur within the first few tens of milliseconds of evoked response at the auditory cortex in ISSNHL. The mechanisms of healthy-side dominance might be ascribed to a functional retune of auditory pathways, i.e. conjoined contralateral inhibition and ipsilateral excitation of the auditory pathway in response to healthy-ear stimulation. The effect could be registered in cortical responses.

Increasing expression of GST-pi MIF, and ID1 genes in chemoresistant prostate cancer cells

The differential expression of genes and related proteins of multidrug resistance in chemoresistant prostate cancer cell lines were elucidated in this study. RNA extracted from doxorubicin-resistant rat prostate cancer (PCa) cells (AT3/ADR1000) and native PCa cells was hybridized to expression arrays containing cDNAs from 588 known genes. Differential expression of selected genes was confirmed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) analysis. Protein contents were measured by fluorescent flow cytometry and immunoblotting. Localization of selected proteins in cells was observed by immunocytochemical staining. Up-regulation of eleven genes and down-regulation of one single gene were displayed in the chemoresistant prostate cancer cells. Overexpression of mRNAs in macrophage migration inhibitory factor (MIF), DNA binding protein inhibitor 1 (ID1), and glutathione S-transferase-pi (GST-pi) were confirmed by gene-specific RT-PCR. Protein over-expression of GST-pi, MIF, and ID1 in resistant cells were 3.3-, 1.5-, and 1.5-fold to native cells, respectively. Immunocytochemistry revealed that GST-pi, MIF, and ID1 were present primarily in the cytoplasm of tumor cells, but ID1 also could be found in the nucleus. AT3/ADR1000 drug-resistant PCa cells displayed significantly increased expression of GST-pi, MIF, and ID1 proteins when compared with native PCa cells. It indicates these genes may play a role in drug resistance of prostate cancer.

Redistribution of androgen receptors in acquired hormone-refractory prostate cancer cells

The dynamic translocation of androgen receptors (ARs) in prostate cancer cells after hormone conversion was studied. The prostate cancer cell line LNCaP was converted into androgen-independent sublines after long-term treatment with 5alpha-reductase inhibitor and steroid-depleted medium. Immunohistochemical, immunofluorescent staining and laser scanning microscopy were used to observe the redistribution and serial translocation of ARs in these tumor cells. The androgen-independent tumor cells (LNCaP/Fin and LNCaP/HR) grew slower than native cells with fibroblastic-like characteristics. On immunohistochemical and immunofluorescent double staining, translocation and exocytosis of ARs were noted in androgen- independent tumor cells much more markedly than in native cells. Furthermore, laser-scanning microscopy revealed serial image changes of AR vesicle shifting and exocytosis in androgen-converted tumor cells. Translocation and exocytosis processes were observed in androgen-independent prostate cancer cells. ARs lose partly normal cellular biologic role during hormone manipulation.

Energy responses of the LiF series TL pellets to high-energy photons in the energy range from 1.25 to 21 MV

The energy responses for the KLT-300(LiF:Mg,Cu,Na,Si, Korea), GR-200(LiF:Mg,Cu,P, China) and MCP-N(LiF:Mg,Cu,P, Poland) thermoluminescence(TL) pellets were studied for a photon radiation with energies from 1.25 MeV(60Co) to 21 MV (Microtron) to verify the usefulness of the calibration for the radiotherapy beams. The International Atomic Energy Agency (IAEA) and the World Health Organization (WHO) have performed thermoluminescence dosimetry (TLD) audits to verify the calibration of the beams by TL powder, but TL pellets were used in this study because the element correction factor (ECF), defined as the factor to correct the variations that all TL dosemeters cannot be manufactured to have exactly the same TL efficiency, for each TL pellet could be accurately derived and be handled conveniently when compared with the powder. Also several works for the energy response of the TLDs were done for the low-energy photon beams up to 60Co, but they will be extended in this experiment to the high photon energies (up to 20 MV), which are widely used in the therapy level of a radiation. The PTW 30006 ionisation chamber was calibrated by the Korea primary standards to establish the air-kerma rates and the TL pellets were irradiated in a specially designed waterproof pellet holder in a water phantom (30 x 30 x 30 cm3) just like the IAEA postal audits programme. This result was compared with that of another type of phantom [10 (W) x 10 (L) x 10 (H) cm3 PMMA Perspex phantom for the 60Co and 6 MV photon, and 10 x 10 x 20 (H) cm3 for the 10 and 21 MV photon] for its convenient use and easy handling and installation in a hospital. The results show that the differences of the responses for the water phantom and PMMA Perspex phantom were negligible, which is contrary to the general conception that a big difference would be expected. For an application of these results to verify the therapy beams, an appropriate energy correction factor should be applied to the energies and phantom types in use.

Monte Carlo simulation of the photon beam characteristics from medical linear accelerators

The MCNPX code has been employed on a personal computer to calculate the dosimetric characteristics of the photon beams from the 6 MV Siemens MX2 and the 10 MV Varian Clinac 2100C linear accelerators. A model of the treatment head includes the major geometric structure within the beam path. The model was used to calculate the energy spectra of the photon beam, percentage depth dose and the dose profiles. The accuracy of the calculated results is examined by comparing them with the measured dose distributions for the two machines. The computed and measured depth dose curves agree to within 2% for all the depths beyond the build-up region for both treatment machines. The calculations agree to within 2% of the measured profiles within the 100-50% dose level. It has been found that the MCNPX code is an effective tool for simulating the clinical photon beam.

Thermoluminescence emission spectra for the LiF:Mg,Cu,Na,Si thermoluminescent materials with various concentrations of the dopants (3-D measurement)

The thermoluminescence (TL) emission spectra from LiF TL materials, called KLT-300 (LiF:Mg,Cu,Na,Si) with various dopant concentrations are measured and analysed. These KLT-300 materials were developed by the Korea Atomic Energy Research Institute (KAERI) to achieve an enhancement of the thermal stability in TL readings. Six types of samples are prepared with different dopant concentrations in the following ranges; Mg (0-0.20 mol%), Cu (0-0.05 mol%), Na and Si (0-0.9 mol%). The spectra measurements are carried out for the six types of samples using a TL emission spectra measurement device. The spectra measurement device consists of a monochromator, photomultiplier tube and temperature control unit to thermally stimulate the samples. The measured data shows the light emission during heating of the sample as a function of temperature and wavelength (three-dimensional TL spectra). The spectra were analysed using a method of deconvolution based on gaussian curve. The wavelength of a main peak of the emission spectra changes depending on the existence of the Cu dopant, while intensity of the spectra rapidly changes with the Cu dopant concentrations. The 385 nm emission is mainly observed in all the spectra from the samples with the Cu dopant, but in those from the samples without the Cu dopant a very weak 401 nm emission is mainly observed. However, any change in the wavelength at a main peak of the TL emission spectra from the sample materials with Na and Si dopants is not observed but that in the intensity at a peak of the spectra is observed.

Ground-state properties of Fermi gases in the strongly interacting regime

The ground-state energies and pairing gaps in dilute superfluid Fermi gases have now been calculated with the quantum Monte Carlo method without detailed knowledge of their wave functions. However, such knowledge is essential to predict other properties of these gases such as density matrices and pair distribution functions. We present a new and simple method to optimize the wave functions of quantum fluids using the Green's function Monte Carlo method. It is used to calculate the pair distribution functions and potential energies of Fermi gases over the entire regime from atomic Bardeen-Cooper-Schrieffer superfluid to molecular Bose-Einstein condensation, spanned as the interaction strength is varied.

Dosimetric properties of the newly developed KLT-300 (LiF:Mg,Cu,Na,Si) TL detector

The dosimetric properties of the newly developed KLT-300 (KAERI LiF:Mg,Cu,Na,Si TL detector) in KAERI (Korea Atomic Energy Research Institute) were investigated. The sensitivity of the TL detector was about 30 times higher than that of the TLD-100 by light integration. In the study of the dose linearity of the detector, the dose response was very linear up to 10 Gy and a sublinear response was observed at higher doses. The energy response of the detector was studied for photon energies from 20 to 662 keV. The results show that a maximum response of 1.004 at 53 keV and a minimum response of 0.825 at 20 keV were observed. The reproducibility study for the TL detector was also carried out. The coefficients of variation for each detector separately did not exceed 0.016, and for all the 10 detectors collectively it was 0.0054. IEC Standard requires that the coefficient of variation shall not exceed 0.075. So, the reproducibility of this new TL detector sufficiently satisfied the IEC requirements. A detection threshold of the detector was investigated and found to be 70 nGy by Harshaw 4500 TLD Reader.

On the roles of the dopants in LiF: Mg,Cu,Na,Si thermoluminescent material

In this paper, some results of the study on the roles of the dopants in the LiF:Mg,Cu,Na,Si thermoluminescent (TL) material that was developed at the Korea Atomic Energy Research Institute for radiation protection are presented. Although there have been many studies to investigate the roles of the dopants in LiF:Mg,Cu,P TL material in the TL process, there are some discrepancies in the understanding of the roles of Cu and P between various researchers. In case of LiF:Mg,Cu,Na,Si TL material, there are a few studies on the roles of the dopants. Three kinds of samples in each of which one dopant is excluded, and the optimised sample, were prepared for this study. The measurements and analysis of the three-dimensional TL spectra, based on the temperature, wavelength and intensity, and the glow curves for those samples are used in this study. The results show that Mg plays a role in the trapping of the charge carriers and Cu plays a role in the luminescence recombination process; however, the effect of Na and Si on the glow curve structure and the TL emission spectra is much less than that of Mg and Cu. It is considered that Na and Si each plays a role in the improvement of the luminescence efficiency.

A computer program for the deconvolution of thermoluminescence glow curves

A quick and efficient computer program was developed in order to resolve the peaks from the thermoluminescence (TL) glow curve. The program was designed to be easily used on any MS Windows-based computer with a graphical user interface. In this program, a new method based on the general one-trap TL equation was adopted to analyse the TL glow curve with the traditional first-order, second-order and general-order kinetics model. The method described here, general approximation, generates TL glow peaks and interpolates the relevant TL parameters from the glow data. The program was tested with simulated and experimental TL glow data and the results were found to be adequate and reliable.

Pharmacokinetics of desflurane uptake into the brain and body

The aim of this study was to investigate the pharmacokinetics of desflurane uptake into the brain and body by comparing desflurane concentrations in internal jugular-bulb blood (Jdes), arterial blood (Ades) and pulmonary arterial blood (PAdes) at a fixed inspired desflurane concentration. Thirteen patients (aged 42-72 years) undergoing coronary artery bypass grafting surgery were enrolled in this study. They were anaesthetised using a constant 5% inspired desflurane concentration (CIdes) during the first hour of anaesthesia. Under constant volume-controlled ventilation, CIdes and end-tidal desflurane (CEdes) were measured with an infrared analyser. The desflurane concentration in the blood was analysed using gas chromatography, and cardiac output was measured using an Opti-Q pulmonary artery catheter. It took 24 min for the Jdes to equilibrate with Ades. Both CIdes-CEdes and Ades-PAdes gradients persisted during the study period. There was no further uptake of desflurane into the brain after 24 min but there was near-constant uptake into the body.

Developments in the synthesis of LiF:Mg,Cu,Na,Si TL material

A procedure for synthesis of the highly sensitive pellet-type LiF:Mg,Cu,Na,Si thermoluminescent (TL) detector has been newly developed. It was found that the optimum concentrations of dopants for a pellet-type LiF:Mg,Cu,Na,Si TL detector were found to be Mg: 0.2 mol %, Cu: 0.05 mol %, Na: 0.9 mol%, and Si: 0.9 mol%. The TL sensitivity of this new detector was about 30 times higher than that of the TLD-100 by light integration measurements. Reusability study of the detector was carried out for 10 cycles. The results show that the coefficients of variation for each detector separately did not exceed 0.016, and that for all 10 detectors collectively was 0.0054.

Measurement of the neutron fluence and dose spectra using an extended bonner sphere and a tissue-equivalent proportional counter

A conventional Bonner Sphere (BS) set consisting of six polyethylene spheres was modified to enhance its response to a high-energy neutron by putting a lead shell inside a polyethylene moderator. The response matrix of an extended BS was calculated using the MCNPX code and calibrated using a 252Cf neutron source. In order to survey the unknown photon and neutron mixed field, a spherical tissue equivalent proportional counter (TEPC) was constructed and assembled as a portable measurement system. The extended BS and the self-constructed TEPC were employed to determine the dosimetric quantities of the neutron field produced from the thick lead target bombarded by the 2.5 GeV electron beam of Pohang Accelerator Laboratory (PAL) and the neutron calibration field of Korea Atomic Energy Research Institute (KAERI).

Human immunodeficiency virus type 1 subtype C molecular phylogeny: consensus sequence for an AIDS vaccine design?

An evolving dominance of human immunodeficiency virus type 1 subtype C (HIV-1C) in the AIDS epidemic has been associated with a high prevalence of HIV-1C infection in the southern African countries and with an expanding epidemic in India and China. Understanding the molecular phylogeny and genetic diversity of HIV-1C viruses may be important for the design and evaluation of an HIV vaccine for ultimate use in the developing world. In this study we analyzed the phylogenetic relationships (i) between 73 non-recombinant HIV-1C near-full-length genome sequences, including 51 isolates from Botswana; (ii) between HIV-1C consensus sequences that represent different geographic subsets; and (iii) between specific isolates and consensus sequences. Based on the phylogenetic analyses of 73 near-full-length genomes, 16 "lineages" (a term that is used hereafter for discussion purposes and does not imply taxonomic standing) were identified within HIV-1C. The lineages were supported by high bootstrap values in maximum-parsimony and neighbor-joining analyses and were confirmed by the maximum-likelihood method. The nucleotide diversity between the 73 HIV-1C isolates (mean value of 8.93%; range, 2.9 to 11.7%) was significantly higher than the diversity of the samples to the consensus sequence (mean value of 4.86%; range, 3.3 to 7.2%, P < 0.0001). The translated amino acid distances to the consensus sequence were significantly lower than distances between samples within all HIV-1C proteins. The consensus sequences of HIV-1C proteins accompanied by amino acid frequencies were presented (that of Gag is presented in this work; those of Pol, Vif, Vpr, Tat, Rev, Vpu, Env, and Nef are presented elsewhere [http://www.aids.harvard.edu/lab_research/concensus_sequence.htm]). Additionally, in the promoter region three NF-kappa B sites (GGGRNNYYCC) were identified within the consensus sequences of the entire set or any subset of HIV-1C isolates. This study suggests that the consensus sequence approach could overcome the high genetic diversity of HIV-1C and facilitate an AIDS vaccine design, particularly if the assumption that an HIV-1C antigen with a more extensive match to the circulating viruses is likely to be more efficacious is proven in efficacy trials.

ADP-ribosylating binary toxin genes of Clostridium difficile strain CCUG 20309

The cdt genes that encode a binary ADP-ribosylating toxin in Clostridium difficile were first characterized from a toxigenic C. difficile strain CD196 in 1997. We report here C. difficile strain CCUG 20309 (ATCC 8864), a strain that produces toxin B but not toxin A, also carry a complete set of cdtA and cdtB genes. These genes were sequenced by cycle sequencing method. The 2 ORFs and the intergenic sequences of these 2 strains have a homology of 99.6%. Interestingly, 9 extra bases were found within the cdtA gene of strain CCUG 20309 which do not affect the downstream region of the ORF. Using the same homologous primers, the highly toxigenic reference strain VPI 10463 was found to carry only parts of the 2 ORFs while a nontoxigenic strain ATCC 8884 does not carry any of the cdt genes. Though it remains to be determined whether these genes are expressed, it is significant that strain CCUG 20309 contains the complete set of cdt genes. We speculate that the putative expressed proteins may contribute to pathogenesis, for example, enterotoxicity, of this unique strain of bacteria.

Aggressive angiomyxoma of the scrotum

Aggressive angiomyxoma is a rare and nonmetastasizing soft tissue tumor of the pelvis and perineum and occurs almost exclusively in adult females. It infiltrates locally and has a high risk of local recurrence. Recommended treatment of the symptomatic patient is wide excision with tumor-free margins and close postoperative monitoring. Herein, a case of aggressive angiomyxoma in an adult male is described, which arose in the scrotum over 12 months. The tumor showed an intermediate signal on T1-weighted MRI images. Contrast-enhanced T1-weighted images showed good enhancement. Wide excision of the tumor was performed. The surgical specimen measured 7 x 5 x 5 cm in size and weighed 80 g. The tumor's surface was smooth and had a gelatinous cut surface. Grossly, it was encapsulated with a pleura-like membrane and had a finger-like projection. Microscopically, sections showed many walled vessels of various sizes, collagen fibrils, a loose myxoid background. and spindle stroma cells. MRI and CT showed the angiomatous and myxomatous nature of the tumor wall. To the authors' knowledge, this is the first report to describe MRI findings in scrotal angiomyxoma.

Thermoluminescence characteristics of teflon embedded CaSO4:Dy TLD

The Korea Atomic Energy Research Institute (KAERI) is manufacturing CaSO4:Dy Teflon TL pellets which have more sensitivity and stability than commercial TLD. A method is presented of preparing the CaSO4:Dy phosphor-embedded Teflon powder, which is then compressed to a thin pellet form used as the TLD element. Investigations are made to determine optimum preparation conditions and dosimetric characteristics of the CaSO4:Dy Teflon pellet such as the sensitivity, energy response, dose response, fading, re-usability, and lowest level of detection. The results show that the sensitivity of the CaSO4:Dy pellet is 2 times higher than that of the commercial Teledyne CaSO4:Dy pellet. A dose-response was observed to be linear in the range from 10(-5) to 10 Gy. The relative energy response in the low energy region was 9.6 (normalised to the 137Cs gamma source), and the fading rate was about 10% for five months. The re-usability was estimated to be more than 60 cycles, and the low level of detection dose was 22 microGy. From the results, the CaSO4:Dy pellet developed in KAERI can be successfully used in personal dosemeters through appropriate filter design for compensating the energy response.

Comparison of TLD algorithms for monochromatic fluorescent radiation and continuous spectrum X rays

A personal dosimetry system is required to measure the personal dose equivalent accurately in a wide range of radiation fields. However, the dose evaluation algorithm at the Korea Atomic Energy Research Institute (KAERI) has been developed with the spectral X ray fields described in the American National Standards Institute (ANSI) Standard N13.11 and the actual fields to be monitored may be significantly different from these. To evaluate the dose more accurately when workers are exposed to non-ANSI N13.11 radiation fields, a dose evaluation algorithm using monochromatic radiation (monochromatic algorithm) was developed using the experimental data of the energy responses of CaSO4:Dy thermoluminescent materials irradiated by monochromatic fluorescent X ray fields recently established at KAERI; this was compared with another algorithm developed on the basis of the ANSI N13.11 continuous spectrum X ray fields (spectrum algorithm). The paper concludes with discussions about some results of the algorithm test, including mixed field irradiation and angular response, conducted in an International Atomic Energy Authority/Regional Cooperation of Asia (IAEA/RCA) intercomparison study.

Analysis of the glow curves obtained from LiF:Mg,Cu,Na,Si TL material using the general order kinetics model

Three-dimensional thermoluminescence (TL) spectra based on temperature, wavelength and intensity for newly developed LiF:Mg,Cu,Na,Si TL material at the Korea Atomic Energy Research Institute (KAERI) were measured and analysed. The glow curves were obtained by integration of luminescence intensity over all wavelengths at each temperature, and various trapping parameters related to the traps were determined by analysing these curves. A computerised glow curve deconvolution (CGCD) method which was based on the general order kinetics (GOK) model was used for the glow curve analysis. The glow curves of LiF:Mg,Cu,Na,Si TL material were deconvoluted to six isolated glow curves which have peak temperatures at 333, 374, 426, 466, 483 and 516 K. The main glow peak of peak temperature at 466 K had activation energy of 2.06 eV and a kinetic order of 1.05. This TL material was also found to have three recombination centres, 1.80 eV, 2.88 eV and 3.27 eV by analysis of the TL spectra.

The application of intramolecular radical cyclizations of acylsilanes in the regiospecific formation of cyclic silyl enol ethers

Acylsilanes with terminal alpha-stannyl bromide or xanthate functionalities are prepared. Alpha-stannyl radicals generated from these acylsilanes undergo intramolecular cyclizations to give cyclic silyl enol ethers regiospecifically. The radical processes involve radical cyclization, Brook rearrangement, and beta-fragmentation in sequence. A tributylstannyl group serves as the radical leaving group. The newly formed sigma-bond and pi-bond are located between the same two carbon atoms. This approach is limited to the formation of five-membered rings. In another route, omega-bromo-alpha-phenylsulfonylacylsilanes are synthesized. The radical cyclizations of these alpha-sulfonylacylsilanes also give cyclic silyl enol ethers. The phenylsulfonyl moiety is the radical leaving group in this system. Furthermore, the newly formed sigma-bond and pi-bond are located at adjacent positions sharing a single carbon atom. The latter approach is effective for both five- and six-membered ring formation.

Definition and measurement of child malnutrition

Child Malnutrition has been defined or described in many ways. To summarize the common points, child malnutrition may be defined as a pathological state resulting from inadequate nutrition, including undernutrition (protein-energy malnutrition) due to insufficient intake of energy and other nutrients; overnutrition (overweight and obesity) due to excessive consumption of energy and other nutrients; deficiency diseases due to insufficient intake of one or more specific nutrients such as vitamins or minerals. In the assessment of child malnutrition, a large number of measures are available. Among these measuring methods, Z-score, growth charts, weight-for-length index (WLI), height standard weight, body mass index, skin fold thickness and clinical grading diagnosis standard for child malnutrition are selected for discussion. The same set of anthropometry data of a group of preschool children was analyzed by using different methods. The results showed that it was very difficult to determine the nutritional state of children using a single index. For a given group of children, Z-score method is recommended to observe their height, weight and weight for height at the same time in order to have a comprehensive understanding.

Dietary intake of some essential micronutrients in China

OBJECTIVE

Based on the data collected in the 1992 national nutrition survey in China, the food consumption and nutrients intake were calculated, and the consumption of some micronutrients was evaluated.

METHOD

Dietary data were obtained by using a three days' inventory change plus food weighing in combination with 24 hours recall method for three consecutive days. The food consumption and nutrients intake were calculated in accordance with the Chinese food composition table. The consumption of some micronutrients was evaluated in reference to the Chinese RDAs.

RESULTS

The average intakes of niacin, ascorbic acid and vitamin E were sufficient, whereas that of zinc, selenium and thiamin were between 80% and 90% RDAs. The consumption of calcium, retinol equivalent and riboflavin was low compared with the Chinese RDAs. Calcium was the most insufficient nutrient in Chinese diet.

CONCLUSION

Food fortification seems necessary for improving the nutritional status of some micronutrients in China.

Refolding and characterization of a yeast dehydrodolichyl diphosphate synthase overexpressed in Escherichia coli

Dehydrodolichyl diphosphate synthase (DDPPs) catalyzes the sequential condensation of isopentenyl diphosphate with farnesyl diphosphate to synthesize long-chain dehydrodolichyl diphosphate, which serves as a precursor of glycosyl carrier in glycoprotein biosynthesis in eukaryotes. To perform kinetic and structural studies of DDPPs, we have expressed yeast DDPPs using Escherichia coli as the host cell. Thioredoxin and His tag were utilized to increase the solubility of the recombinant protein and facilitate its purification using Ni-nitrilotriacetic acid (NTA) column. The protein was overexpressed in E. coli but mostly existed in pellet in the absence of detergent. The low quantity of soluble DDPPs was purified using Ni-NTA, Mono Q anion-exchange, and size-column chromatographies. The protein in the pellet was solubilized with 7 M urea and purified using Ni-NTA under denaturing condition. The protein refolding was achieved via the stepwise dialysis to remove the denaturant in the presence of 6 mM beta-mercaptoethanol. Detergent n-octyl-beta-d-glucopyranoside and Triton X-100 increased the solubility of the DDPPs so that refolding can be performed at higher protein concentration. Alternatively, on-column refolding was carried out in a single step to obtain the active protein in large quantities. beta-Mercaptoethanol and Triton were both required in this quick refolding process. The kinetic studies indicated that the soluble and refolded DDPPs have comparable activities (k(cat) = 2 x 10(-4) s(-1)). Unlike its bacterial homologue, undecaprenyl diphosphate synthase, yeast DDPPs activity was not enhanced by Triton.

Isolated craniosynostosis: prenatal ultrasound of scaphocephaly with polyhydramnios

Craniosynostosis is an abnormal shape or dimension of the skull caused by premature closure of one or more skull sutures. It includes scaphocephaly, brachycephaly, oxycephaly, plagiocephaly, trigonocephaly, turricephaly, and a cloverleaf-shaped head. The only cases of craniosynostosis that have been reported concern fetuses with complex and marked craniosynostosis syndromes such as acrocraniofacial dysostosis, Apert's syndrome, Beare-Stevenson cutis gyratum syndrome, Calabro's syndrome, etc. Isolated or simple craniosynostosis, however, is a developmental anomaly rarely found on routine ultrasound examination. We present a case that was diagnosed as scaphocephaly with moderate polyhydramnios by prenatal ultrasound. No other structural anomaly was detected, and the karyotyping was normal. So isolated sagittal craniosynostosis was diagnosed prenatally and was confirmed by postnatal skull radiography as well as 3-dimensional computed tomography. The infant underwent bilateral parietal craniectomy at the age of 3 months. He obtained a good result with no mental problems 4 years after the operation. To our knowledge, this is the second report on the prenatal detection of an isolated form of craniosynostosis.

Associations of CCR5, CCR2, and stromal cell-derived factor 1 genotypes with human immunodeficiency virus disease progression in patients receiving nucleoside therapy

Genotype data for CCR5, CCR2, and stromal cell-derived factor 1 (SDF-1) were obtained from 354 human immunodeficiency virus type 1 (HIV-1)-positive subjects who were being treated with nucleosides. Associations with HIV-1 load, HIV syncytium-inducing (SI) phenotype, CD4 cell count, and disease progression were analyzed. No differences in HIV-1 load or CD4 cell count were observed between wild type (+) and variant genotypes. Changes from non-SI to SI viral phenotype were more frequent in heterozygotes with a 32-bp deletion (Delta32) in the CCR5 gene than in + homozygotes (40% vs. 7%; P=.01). In a multivariate analysis, heterozygous CCR5 Delta32 was associated with reduced hazard of progression (hazard ratio, 0.32; P=.02). Subjects homozygous for the SDF-1 3'A variant had more-rapid disease progression (P=.008). The SDF-1 homozygous 3'A variant was related to more-rapid disease progression, and CCR5 Delta32 was associated with reduced rates of hazard for disease progression in nucleoside-treated subjects.