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.

Preconceptional and prenatal exposure to air pollutants and risk of gestational diabetes in the MADRES prospective pregnancy cohort study

Background

Air pollution has been associated with gestational diabetes mellitus (GDM). We aim to investigate susceptible windows of air pollution exposure and factors determining population vulnerability.

Methods

We ascertained GDM status in the prospective Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) pregnancy cohort from Los Angeles, California, USA. We calculated the relative risk of GDM by exposure to ambient particulate matter (PM10; PM2.5), nitrogen dioxide (NO2), and ozone (O3) in each week from 12 weeks before to 24 weeks after conception, adjusting for potential confounders, with distributed lag models to identify susceptible exposure windows. We examined effect modification by prenatal depression, median-split pre-pregnancy BMI (ppBMI) and age.

Findings

Sixty (9.7%) participants were diagnosed with GDM among 617 participants (mean age: 28.2 years, SD: 5.9; 78.6% Hispanic, 11.8% non-Hispanic Black). GDM risk increased with exposure to PM2.5, PM10, and NO2 in a periconceptional window ranging from 5 weeks before to 5 weeks after conception: interquartile-range increases in PM2.5, PM10, and NO2 during this window were associated with increased GDM risk by 5.7% (95% CI: 4.6-6.8), 8.9% (8.1-9.6), and 15.0% (13.9-16.2), respectively. These sensitive windows generally widened, with greater effects, among those with prenatal depression, with age ≥28 years, or with ppBMI ≥27.5 kg/m2, than their counterparts.

Interpretation

Preconception and early-pregnancy are susceptible windows of air pollutants exposure that increased GDM risk. Prenatal depression, higher age, or higher ppBMI may increase one's vulnerability to air pollution-associated GDM risk.

Funding

National Institutes of Health, Environmental Protection Agency.

Identifying pre-conception and pre-natal periods in which ambient air pollution exposure affects fetal growth in the predominately Hispanic MADRES cohort

BACKGROUND

It is well documented that persons of color experience disproportionate exposure to environmental contaminants, including air pollution, and have poorer pregnancy outcomes. This study assessed the critical windows of exposure to ambient air pollution on in utero fetal growth among structurally marginalized populations in urban Los Angeles.

METHODS

Participants (N = 281) from the larger ongoing MADRES pregnancy cohort study were included in this analysis. Fetal growth outcomes were measured on average at 32 [Formula: see text] 2 weeks of gestation by a certified sonographer and included estimated fetal weight, abdominal circumference, head circumference, biparietal diameter and femur length. Daily ambient air pollutant concentrations were estimated for four pollutants (particulate matter less than 2.5 µm (PM_2.5) and less than 10 µm (PM₁₀) in aerodynamic diameter, nitrogen dioxide (NO₂), and 8-h maximum ozone (O₃)) at participant residences using inverse-distance squared spatial interpolation from ambient monitoring data. Weekly gestational averages were calculated from 12 weeks prior to conception to 32 weeks of gestation (44 total weeks), and their associations with growth outcomes were modeled using adjusted distributed lag models (DLMs).

RESULTS

Participants were on average 29 years [Formula: see text] 6 old and predominately Hispanic (82%). We identified a significant sensitive window of PM_2.5 exposure (per IQR increase of 6 [Formula: see text]³) between gestational weeks 4-16 for lower estimated fetal weight [Formula: see text] _averaged4-16 = -8.7 g; 95% CI -16.7, -0.8). Exposure to PM_2.5 during gestational weeks 1-23 was also significantly associated with smaller fetal abdominal circumference ([Formula: see text] _averaged1-23 = -0.6 mm; 95% CI -1.1, -0.2). Additionally, prenatal exposure to PM₁₀ (per IQR increase of 13 [Formula: see text]³) between weeks 6-15 of pregnancy was significantly associated with smaller fetal abdominal circumference ([Formula: see text] _{averaged6-15 =} -0.4 mm; 95% CI -0.8, -0.1).

DISCUSSION

These results suggest that exposure to particulate matter in early to mid-pregnancy, but not preconception or late pregnancy, may have critical implications on fetal growth.

The impact of GPS-derived activity spaces on personal PM2.5 exposures in the MADRES cohort

BACKGROUND

In-utero exposure to particulate matter with aerodynamic diameter less than 2.5 μm (PM_2.5) is associated with low birth weight and health risks later in life. Pregnant women are mobile and locations they spend time in contribute to their personal PM_2.5 exposures. Therefore, it is important to understand how mobility and exposures encountered within activity spaces contribute to personal PM_2.5 exposures during pregnancy.

METHODS

We collected 48-h integrated personal PM_2.5 samples and continuous geolocation (GPS) data for 213 predominantly Hispanic/Latina pregnant women in their 3^rd trimester in Los Angeles, CA. We also collected questionnaires and modeled outdoor air pollution and meteorology in their residential neighborhood. We calculated three GPS-derived activity space measures of exposure to road networks, greenness (NDVI), parks, traffic volume, walkability, and outdoor PM_2.5 and temperature. We used bivariate analyses to screen variables (GPS-extracted exposures in activity spaces, individual characteristics, and residential neighborhood exposures) based on their relationship with personal, 48-h integrated PM_2.5 concentrations. We then built a generalized linear model to explain the variability in personal PM_2.5 exposure and identify key contributing factors.

RESULTS

Indoor PM_2.5 sources, parity, and home ventilation were significantly associated with personal exposure. Activity-space based exposure to roads was associated with significantly higher personal PM_2.5 exposure, while greenness was associated with lower personal PM_2.5 exposure (β = -3.09 μg/m³ per SD increase in NDVI, p-value = 0.018). The contribution of outdoor PM_2.5 to personal exposure was positive but relatively lower (β = 2.05 μg/m³ per SD increase, p-value = 0.016) than exposures in activity spaces and the indoor environment. The final model explained 34% of the variability in personal PM_2.5 concentrations.

CONCLUSIONS

Our findings highlight the importance of activity spaces and the indoor environment on personal PM_2.5 exposures of pregnant women living in Los Angeles, CA. This work also showcases the multiple, complex factors that contribute to total personal PM_2.5 exposure.

Risk factors for internet addiction among Croatian university students during the COVID-19 pandemic

Background

Following the increased internet use due to the COVID-19 pandemic there have been concerns regarding an elevated risk of developing internet addiction (IA). University students are especially prone to develop IA and risk factors for its development in this population during pandemics are not fully investigated nor understood. This study aimed to identify possible risk factors of IA in the studied population during the ongoing pandemic and to compare it with risk factors in pre-pandemic time.

Methods

In April 2016 and April 2022 a validated, anonymous questionnaire that contained questions regarding demographic data, as well as Young's Internet Addiction Test, was self-administered to a cross-faculty representative student sample of the University of Osijek, Croatia.

Results

The study included 1602 university students median age of 21 years (interquartile range 20-22), 34.5% males, and 65.5% females. There was no statistically significant difference in the median age between the two student samples (p = 0.234). The main reason for internet use (social networking and entertainment and online gaming) was considered the significant risk factor for IA in a studied population in pre-pandemic time (the year 2016) and pandemic time (the year 2022) (p < 0.001). In pre-pandemic time the IA was more frequent in males (p = 0.046) while the difference in IA prevalence between sexes did not exist during pandemics (p = 0.160). During pandemics, the students who did not work during their study had higher proportions of IA (p = 0.021) while there was no difference in IA prevalence among students regarding their working status during the study in pre-pandemic time (p = 0.251).

Conclusions

During the COVID-19 pandemic working status of students has been recognized as the new risk factor for IA in the Croatian university students population. Further studies are needed to identify other possible risk factors for IA in the studied population during pandemics.

Key messages

Ablation of residual potentials along the circumferential line reduces acute reconnection in patients undergoing pulmonary vein isolation

Introduction

Acute pulmonary vein (PV) reconnection is frequently encountered in patients with atrial fibrillation (AF) subjected to PV isolation (PVI).

Purpose

In this prospective, multicenter, randomized study, we investigated whether the identification and ablation of sites along the circumferential line with specific electrogram criteria indicative of nontrasmurality, after initial achievement of PVI, reduces acute PV reconnection rate.

Methods

Patients referred for AF ablation at five European centers were enrolled. PVI with antral circumferential isolation of ipsilateral PVs was performed using a contact force sensing ablation catheter delivering 35–40W at the anterior/superior and 30W at the posterior wall with target ablation index of 550 at the anterior wall/roof and 400 at the posterior/inferior segments. Following PVI, mapping with the ablation catheter was performed to identify residual potentials (RP) along the ablation line, defined as bipolar amplitude ≥0.2 mV or 0.1–0.19 mV combined with negative component of the unipolar electrogram as recorded by the 3D mapping system. Ipsilateral PV sets with RPs were randomized to either no further ablation (Group B) or to additional ablation of RPs (Group C). The primary study endpoint was defined as spontaneous or adenosine-mediated recovery of conduction after 30-minute waiting period which was also evaluated in ipsilateral PV sets without residual potentials (Group A).

Results

In total, 109 patients (59.3±10.6 years, 47% hypertension, 9.3% diabetes, left atrial diameter 39.1±4.6mm) were enrolled in the study. After initial isolation of 194 PV pairs, 98 PV pairs had no RPs (Group A) while the remaining 96 with RPs were randomized to either Group B or C (48 PV pairs each). The number of sites with RPs did not differ between groups B and C (4.1±2.5 vs 4.7±3.2, p=0.27). The occurrence of the primary endpoint in Group A was 7.1%. Ablation of residual potentials resulted in significant reduction of spontaneous or adenosine mediated reconnection (14.6% vs 47.9%, p&lt;0.001).

Conclusion

Following initial PVI achievement, ablation of RPs along the antral circumferential line reduces spontaneous or adenosine-mediated acute PV reconnection rate in patients undergoing first-time AF ablation. Therefore, scanning of the PVI line in search of weak links with specific electrogram criteria indicative of nontrasmurality, and subsequent deployment of bonus lesions, could represent a convenient and practical way to reduce acute PV reconnection. Further studies are required to assess long term effects on AF recurrence rates.

Funding Acknowledgement

Type of funding sources: None.

Association Between Ambient Air Pollution and Birth Weight by Maternal Individual- and Neighborhood-Level Stressors

IMPORTANCE

Fetal growth is precisely programmed and could be interrupted by environmental exposures during specific times during pregnancy. Insights on potential sensitive windows of air pollution exposure in association with birth weight are needed.

OBJECTIVE

To examine the association of sensitive windows of ambient air pollution exposure with birth weight and heterogeneity by individual- and neighborhood-level stressors.

DESIGN, SETTING, AND PARTICIPANTS

Data on a cohort of low-income Hispanic women with singleton term pregnancy were collected from 2015 to 2021 in the ongoing Maternal and Developmental Risks from Environmental and Social Stressors cohort in Los Angeles, California.

EXPOSURES

Daily ambient particulate matter with aerodynamic diameter less than 10 μm (PM10) and aerodynamic diameter less than 2.5 μm (PM2.5), nitrogen dioxide (NO2), and 8-hour maximum ozone were assigned to residential locations. Weekly averages from 12 weeks before conception to 36 gestational weeks were calculated. Individual-level psychological stressor was measured by the Perceived Stress Scale. Neighborhood-level stressor was measured by the CalEnviroScreen 4.0.

MAIN OUTCOMES AND MEASURES

Sex-specific birth weight for gestational age z score (BWZ). The associations between air pollutant and BWZ were estimated using distributed lag models to identify sensitive windows of exposure, adjusting for maternal and meteorologic factors. We stratified the analyses by Perceived Stress Scale and CalEnviroScreen 4.0. We converted the effect size estimation in BWZ to grams to facilitate interpretation.

RESULTS

The study included 628 pregnant women (mean [SD] age, 22.18 [5.92] years) and their newborns (mean [SD] BWZ, -0.08 [1.03]). On average, an interquartile range (IQR) increase in PM2.5 exposure during 4 to 22 gestational weeks was associated with a -9.5 g (95% CI, -10.4 to -8.6 g) change in birth weight. In stratified models, PM2.5 from 4 to 24 gestational weeks was associated with a -34.0 g (95% CI, -35.7 to -32.4 g) change in birth weight and PM10 from 9 to 14 gestational weeks was associated with a -39.4 g (95% CI, -45.4 to -33.4) change in birth weight in the subgroup with high Perceived Stress Scale and high CalEnviroScreen 4.0 scores. In this same group, NO2 from 9 to 14 gestational weeks was associated with a -40.4 g (95% CI, -47.4 to -33.3 g) change in birth weight and, from 33 to 36 gestational weeks, a -117.6 g (95% CI, -125.3 to -83.7 g) change in birth weight. Generally, there were no significant preconception windows for any air pollutants or ozone exposure with birth weight.

CONCLUSIONS AND RELEVANCE

In this cohort study, early pregnancy to midpregnancy exposures to PM2.5, PM10, and NO2 were associated with lower birth weight, particularly for mothers experiencing higher perceived stress and living in a neighborhood with a high level of stressors from environmental pollution.

Health Outcomes in Children Associated with Prenatal and Early-Life Exposures to Air Pollution: A Narrative Review

(1) Background: The developmental origins of health and disease (DOHaD) hypothesis links adverse fetal exposures with developmental mal-adaptations and morbidity later in life. Short- and long-term exposures to air pollutants are known contributors to health outcomes; however, the potential for developmental health effects of air pollution exposures during gestation or early-childhood have yet to be reviewed and synthesized from a DOHaD lens. The objective of this study is to summarize the literature on cardiovascular and metabolic, respiratory, allergic, and neuropsychological health outcomes, from prenatal development through early childhood, associated with early-life exposures to outdoor air pollutants, including traffic-related and wildfire-generated air pollutants. (2) Methods: We conducted a search using PubMed and the references of articles previously known to the authors. We selected papers that investigated health outcomes during fetal or childhood development in association with early-life ambient or source-specific air pollution exposure. (3) Results: The current literature reports that prenatal and early-childhood exposures to ambient and traffic-related air pollutants are associated with a range of adverse outcomes in early life, including cardiovascular and metabolic, respiratory and allergic, and neurodevelopmental outcomes. Very few studies have investigated associations between wildfire-related air pollution exposure and health outcomes during prenatal, postnatal, or childhood development. (4) Conclusion: Evidence from January 2000 to January 2022 supports a role for prenatal and early-childhood air pollution exposures adversely affecting health outcomes during development. Future studies are needed to identify both detrimental air pollutants from the exposure mixture and critical exposure time periods, investigate emerging exposure sources such as wildfire, and develop feasible interventional tools.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

In utero exposure to near-roadway air pollution and autism spectrum disorder in children

IMPORTANCE

Previous studies have reported associations between in utero exposure to regional air pollution and autism spectrum disorders (ASD). In utero exposure to components of near-roadway air pollution (NRAP) has been linked to adverse neurodevelopment in animal models, but few studies have investigated NRAP association with ASD risk.

OBJECTIVE

To identify ASD risk associated with in utero exposure to NRAP in a large, representative birth cohort.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective pregnancy cohort study included 314,391 mother-child pairs of singletons born between 2001 and 2014 at Kaiser Permanente Southern California (KPSC) hospitals. Maternal and child data were extracted from KPSC electronic medical records. Children were followed until: clinical diagnosis of ASD, non-KPSC membership, death, or December 31, 2019, whichever came first. Exposure to the complex NRAP mixture during pregnancy was assessed using line-source dispersion models to estimate fresh vehicle emissions from freeway and non-freeway sources at maternal addresses during pregnancy. Vehicular traffic load exposure was characterized using advanced telematic models combining traditional traffic counts and travel-demand models with cell phone and vehicle GPS data. Cox proportional-hazard models estimated hazard ratios (HR) of ASD associated with near-roadway traffic load and dispersion-modeled NRAP during pregnancy, adjusted for covariates. Non-freeway NRAP was analyzed using quintile distribution due to nonlinear associations with ASD.

EXPOSURES

Average NRAP and traffic load exposure during pregnancy at maternal residential addresses.

MAIN OUTCOMES

Clinical diagnosis of ASD.

RESULTS

A total of 6,291 children (5,114 boys, 1,177 girls) were diagnosed with ASD. The risk of ASD was associated with pregnancy-average exposure to total NRAP [HR(95% CI): 1.03(1.00,1.05) per 5 ppb increase in dispersion-modeled NOx] and to non-freeway NRAP [HR(95% CI) comparing the highest to the lowest quintile: 1.19(1.11, 1.27)]. Total NRAP had a stronger association in boys than in girls, but the association with non-freeway NRAP did not differ by sex. The association of freeway NRAP with ASD risk was not statistically significant. Non-freeway traffic load exposure demonstrated associations with ASD consistent with those of NRAP and ASD.

CONCLUSIONS

In utero exposure to near-roadway air pollution, particularly from non-freeway sources, may increase ASD risk in children.

Near-roadway air pollution associated with COVID-19 severity and mortality - Multiethnic cohort study in Southern California

BACKGROUND

Air pollution exposure has been associated with increased risk of COVID-19 incidence and mortality by ecological analyses. Few studies have investigated the specific effect of traffic-related air pollution on COVID-19 severity.

OBJECTIVE

To investigate the associations of near-roadway air pollution (NRAP) exposure with COVID-19 severity and mortality using individual-level exposure and outcome data.

METHODS

The retrospective cohort includes 75,010 individuals (mean age 42.5 years, 54% female, 66% Hispanic) diagnosed with COVID-19 at Kaiser Permanente Southern California between 3/1/2020-8/31/2020. NRAP exposures from both freeways and non-freeways during 1-year prior to the COVID-19 diagnosis date were estimated based on residential address history using the CALINE4 line source dispersion model. Primary outcomes include COVID-19 severity defined as COVID-19-related hospitalizations, intensive respiratory support (IRS), intensive care unit (ICU) admissions within 30 days, and mortality within 60 days after COVID-19 diagnosis. Covariates including socio-characteristics and comorbidities were adjusted for in the analysis.

RESULT

One standard deviation (SD) increase in 1-year-averaged non-freeway NRAP (0.5 ppb NO_x) was associated with increased odds of COVID-19-related IRS and ICU admission [OR (95% CI): 1.07 (1.01, 1.13) and 1.11 (1.04, 1.19) respectively] and increased risk of mortality (HR = 1.10, 95% CI = 1.03, 1.18). The associations of non-freeway NRAP with COVID-19 outcomes were largely independent of the effect of regional fine particulate matter and nitrogen dioxide exposures. These associations were generally consistent across age, sex, and race/ethnicity subgroups. The associations of freeway and total NRAP with COVID-19 severity and mortality were not statistically significant.

CONCLUSIONS

Data from this multiethnic cohort suggested that NRAP, particularly non-freeway exposure in Southern California, may be associated with increased risk of COVID-19 severity and mortality among COVID-19 infected patients. Future studies are needed to assess the impact of emerging COVID-19 variants and chemical components from freeway and non-freeway NRAP.

Antivaccination attitudes and intention to take COVID-19 vaccine in Croatian adult population

Background

COVID-19 vaccine is an effective choice to stop the pandemic. To improve COVID-19 vaccination coverage the better understanding of factors influencing individual intention of vaccination is needed. Antivaccination attitudes (AAs) are important predictors of vaccination behaviour. The aim of this study was to investigate the intention to take COVID-19 vaccine in Croatian adult population and to evaluate factors that influence such intention with emphasis on AAs.

Methods

This cross-sectional questionnaire study was conducted during the June 2020 to December 2020 in convenient sample of adults from Split-Dalmatia County at the primary health care setting. Vaccination Attitudes Examination scale (VAX) was used to assess AAs.

Results

The study sample consisted of 632 subjects (52.7% males and 47.3% females). The median age of all subjects was 38.0 (interquartile range (IQR) 29.0 - 48.0) years. The overall prevalence of intention to take COVID-19 vaccine was 46.8%. Males and subjects living with the partner more frequently expressed intention to take COVID-19 vaccine (P = 0.001 and P = 0.015 respectively). The study revealed fair negative correlation between AAs and intention to take COVID-19 vaccine (rho=-0.453; P < 0.001). Subjects who did not intend to take COVID-19 vaccine demonstrated larger mistrust of vaccine benefits, more worries over unforeseen future effects, more concerns about commercial profit and larger preference for natural immunity (P < 0.0001, P < 0.0001, P < 0.0001, P < 0.0001, respectively).

Conclusions

The study showed fairly low proportion of subjects who intended to take COVID-19 vaccine. The study revealed that gender, marital status, and AAs are good predictors of intention to take COVID-19 vaccine in study population. The good predictors of intention to take COVID-19 vaccine in Croatian adult population should be considered during COVID-19 vaccination popularization strategies development.

Key messages

The structured communication campaigns on COVID-19 and COVID-19 vaccines should be developed and directed specifically to all target groups for vaccination.

Understanding the factors that could improve the acceptance of COVID-19 vaccination is crucial to design effective vaccination program.

Attitudes towards vaccination among Croatian high school students

Background

Due to the success of immunization, most of young people have little experience with vaccine preventable diseases. This inexperience may increase vaccine hesitancy in this population subgroup which can potentially jeopardize population vaccination coverage. Understanding young peoples' attitudes towards vaccination is important for vaccination uptake. The aim of this study was to evaluate attitudes towards vaccination among Croatian high school students.

Methods

This online cross-sectional questionnaire study was conducted during the January 2021 to April 2021 in convenient sample of high school students from north-western part of Croatia. Vaccination Attitudes Examination scale (VAX) was used to assess antivaccination attitudes in study population.

Results

The study included 1012 high school students; 29.2% males and 70.8% females; median age 17.0 (interquartile range (IQR) 17.0 - 18.0) years. Overall value of the VAX score in study sample was 50.4±11.1. Female students had more negative attitudes towards vaccination in comparison to male students (P = 0.001). When analysing differences between female and male students according to the VAX scale subcategories the study revealed that female students demonstrated more worries over unforeseen future effects of the vaccination (P &lt; 0.001) while there were no differences between females and males according to the mistrust of vaccine benefits, concerns about commercial profit and preference for natural immunity (P = 0.155, P = 0.157 and P = 0.142, respectively).

Conclusions

The study revealed rather high antivaccination attitudes among Croatian high school students as measured by VAX score. Further studies are needed to better understand factors that influence such attitudes in study population because programs directed towards changing antivaccination attitudes in order to be efficient need to successfully tackle all of those factors.

Key messages

Public health interventions directed towards suppression of antivaccination movement should more involve younger population subgroups, such as elementary and high school students. Positive attitudes towards vaccination in younger population subgroups are one of the crucial preconditions for adequate vaccination coverage.

Croatian blood collection system amid the COVID-19 pandemic

Background

Croatian blood collection system is based on voluntary donation, according to the recommendations of the World Health Organisation and the Council of Europe. The ongoing COVID-19 pandemic has influenced all the dimensions of human lives and the functional pattern of the health care systems in the whole world. The aim of this study was to investigate the influence of ongoing COVID-19 pandemic on Croatian blood collection system and to evaluate the main factors that influence voluntary blood donation practice in blood donors (BDs).

Methods

This cross-sectional questionnaire study was conducted in convenient sample of voluntary BDs from Split-Dalmatia County during the May 2020 to December 2020.

Results

The study sample consisted of 479 regular BDs, 88.5% males and 11.5% females, mean age 39.8±10.8 years. Majority of them had high school education and living with the partner (67.4% and 74.5%, respectively). During COVID-19 pandemic 71.0% of them continued with regular donations while 29% of them postponed their donation. According to the BDs knowledge regarding COVID-19 infection there were 88.9% of those with unsatisfactory and only 11.1% of those with satisfactory knowledge regarding this infection. The study revealed that females, BDs living alone and younger BDs (aged 18 to 43 years) had more frequently postponed blood donation during COVID-19 pandemic (P < 0.0001, P = 0.004 and P = 0.017, respectively). The study further showed that there was no correlation between BDs knowledge about COVID-19 infection and their blood donation practice during ongoing pandemic.

Conclusions

The study revealed that ongoing COVID-19 pandemic impacted the Croatian blood collection system via reduction in the practice of voluntary blood donations. Sociodemographic characteristics of BDs were the main factors that influence Croatian BDs voluntary blood donation practice during pandemic while their knowledge about COVID-19 infection was not correlated with their behaviour.

Key messages

The sustainability of the health care system during a pandemic depends significantly on the blood supply, which is why it is necessary to ensure that blood collection system is continually maintained.

The knowledge of blood donors about COVID-19 infection needs to be improved in order to prevent spreading of the infection generally and especially within this highly important population subgroup.

Adherence to the 4S-AF Scheme in the Balkan region: insights from the BALKAN-AF survey

Background

Current European Society of Cardiology guidelines on atrial fibrillation (AF) propose a structured characterization of AF in order to facilitate the evaluation of patients by physicians at all healthcare levels. The 4S-AF structured scheme includes four domains: stroke risk, symptoms, severity of AF burden and substrate severity.

Purpose

To evaluate the adherence to the 4S-AF scheme in patients with high risk of stroke (CHA2DS2-VASc score ≥3 in females or ≥2 in males) in the post-hoc analysis of the BALKAN-AF dataset.

Methods

Prospective enrolment of consecutive patients with electrocardiographically documented AF was conducted in seven Balkan countries.

Results

Of the 2,712 enrolled patients, 2,712 (100.0%) had data on CHA2DS2-VASc score. 162 (6.0%) had truly low risk of stroke (CHA2DS2-VASc score of 0 in males and 1 in females). 2099 (77.4%) of patients had high risk of stroke and 613 (22.6%) individuals had low or intermediate risk of stroke (CHA2DS2-VASc score &lt;3 in females or &lt;2 in males). 75 (46.3%) of patients with truly low stroke risk and 1555 (74.1%) of patients with high risk of stroke were offered oral anticoagulants (OAC).

Of the 2,712 patients, 2,677 (98.7%) had data on European Heart Rhythm Association (EHRA) symptom score. Among 2,099 patients with high risk of stroke, 703 (33.4%) individuals had EHRA symptom score of 3 or 4. 207 (29.4%) of patients with EHRA symptom score of 3 or 4 and high risk of stroke were offered rhythm control strategy.

620 (55.2%) of patients with first diagnosed AF or paroxysmal AF with high risk of stroke were offered rhythm control strategy.

1927 (91.8%) of patients with high risk of stroke had ≥2 comorbidities. Mean left atrial diameter in patients with high risk of stroke was 46.5±7.8 mm.

Conclusions

OAC overuse was seen in patients with truly low stroke risk, whist OAC underuse was evident in patients with high risk of stroke. The proportion of highly symptomatic patients (EHRA 3 or 4) with high risk of stroke who were offered rhythm control strategy was low. The proportion of patients with first diagnosed AF or paroxysmal AF with high risk of stroke who received rhythm control was small. The majority of AF patients with high risk of stroke had ≥2 comorbidities. Overall, treatment decision-making was not based on the 4S-AF scheme.

Funding Acknowledgement

Type of funding sources: None.

Impact of initial rhythm control with cryoballoon ablation versus drug therapy on atrial fibrillation recurrence and quality of life: results from the Cryo-FIRST study

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Medtronic

OnBehalf

The Cryo-FIRST Investigators

Background

Cryoballoon ablation (CBA) as a first-line rhythm control strategy is superior to antiarrhythmic drugs (AADs) for preventing atrial arrhythmia recurrence; however, the impact of first-line CBA specifically on atrial fibrillation (AF) recurrence and quality of life (QoL) has not been well characterized.

Purpose

To compare AF recurrence and QoL following first-line CBA vs. AAD therapy in patients with paroxysmal AF within the CryoFIRST trial (NCT01803438).

Methods

Patients with recurrent symptomatic paroxysmal AF who had not been administered class I or III AAD therapy for &gt;48 hours were enrolled at 18 sites in 9 countries. Patients were randomized (1:1) to CBA or AAD treatment (Class I or III). Subjects were followed by 7-day Holter at 1, 3, 6, 9, and 12 months. Time-to-first AF recurrence outside of a 90-day blanking period was estimated by Kaplan-Meier analysis.  QoL was evaluated using the Atrial Fibrillation Effect on Quality of Life (AFEQT) and 36-Item Short Form Health Survey (SF-36) v2 questionnaires.

Results

Of the 218 randomized subjects, 187 (86%) completed the 12-month follow-up. By intention-to-treat (ITT) analysis, freedom from AF after blanking was achieved in 86.6% in the CBA and 74.5% in the AAD group (p = 0.023).  There was no difference in the time-to-first serious adverse event between groups. In total, 84.3% of patients in the CBA vs. 75.0% of patients in the AAD arm had a clinically important improvement (≥5 points) in the AFEQT summary score.  The adjusted mean difference in the AFEQT summary score at 12 months was 9.9 points higher in the CBA group (95% CI: 5.5-14.2; P &lt; 0.001).  All AFEQT subscale scores were more favorable in the CBA vs. AAD group at 12 months.  There were no significant group differences in any of the SF-36 health domain scores at 12 months in the ITT analysis.  In the per-protocol analysis, clinically important and significant group differences in favor of CBA were observed at 12 months for 3 of 8 SF-36 health domain scores (physical functioning, general health and social functioning).

Conclusion

CBA is superior to AAD for preventing AF recurrence and improving AF-specific QoL in patients with paroxysmal AF. AFEQT Scores at Baseline and 12 MonthsAFEQT Score, Mean ± Standard DeviationCBAAADAdjusted Mean Difference at 12 Months (CBA vs. AAD)p-valueBaseline12 MonthsBaseline12 MonthsDaily Activities65.3 ± 25.887.8 ± 17.161.0 ± 27.976.6 ± 25.48.9 (3.2-14.6)0.002Symptoms59.9 ± 24.888.8 ± 15.658.4 ± 25.280.9 ± 22.27.1 (1.5-12.7)0.014Treatment Concern59.9 ± 23.189.8 ± 14.060.4 ± 24.577.7 ± 22.212.7 (7.9-17.5)&lt;0.001AFEQT, Atrial Fibrillation Effect on Quality of Life questionnaire. CBA, cryoballoon ablation. AAD antiarrhythmic drug.Abstract Figure. Freedom From Atrial Fibrillation

Ensemble-based deep learning for estimating PM2.5 over California with multisource big data including wildfire smoke

INTRODUCTION

Estimating PM2.5 concentrations and their prediction uncertainties at a high spatiotemporal resolution is important for air pollution health effect studies. This is particularly challenging for California, which has high variability in natural (e.g, wildfires, dust) and anthropogenic emissions, meteorology, topography (e.g. desert surfaces, mountains, snow cover) and land use.

METHODS

Using ensemble-based deep learning with big data fused from multiple sources we developed a PM2.5 prediction model with uncertainty estimates at a high spatial (1 km × 1 km) and temporal (weekly) resolution for a 10-year time span (2008-2017). We leveraged autoencoder-based full residual deep networks to model complex nonlinear interrelationships among PM2.5 emission, transport and dispersion factors and other influential features. These included remote sensing data (MAIAC aerosol optical depth (AOD), normalized difference vegetation index, impervious surface), MERRA-2 GMI Replay Simulation (M2GMI) output, wildfire smoke plume dispersion, meteorology, land cover, traffic, elevation, and spatiotemporal trends (geo-coordinates, temporal basis functions, time index). As one of the primary predictors of interest with substantial missing data in California related to bright surfaces, cloud cover and other known interferences, missing MAIAC AOD observations were imputed and adjusted for relative humidity and vertical distribution. Wildfire smoke contribution to PM2.5 was also calculated through HYSPLIT dispersion modeling of smoke emissions derived from MODIS fire radiative power using the Fire Energetics and Emissions Research version 1.0 model.

RESULTS

Ensemble deep learning to predict PM2.5 achieved an overall mean training RMSE of 1.54 μg/m3 (R2: 0.94) and test RMSE of 2.29 μg/m3 (R2: 0.87). The top predictors included M2GMI carbon monoxide mixing ratio in the bottom layer, temporal basis functions, spatial location, air temperature, MAIAC AOD, and PM2.5 sea salt mass concentration. In an independent test using three long-term AQS sites and one short-term non-AQS site, our model achieved a high correlation (>0.8) and a low RMSE (<3 μg/m3). Statewide predictions indicated that our model can capture the spatial distribution and temporal peaks in wildfire-related PM2.5. The coefficient of variation indicated highest uncertainty over deciduous and mixed forests and open water land covers.

CONCLUSION

Our method can be generalized to other regions, including those having a mix of major urban areas, deserts, intensive smoke events, snow cover and complex terrains, where PM2.5 has previously been challenging to predict. Prediction uncertainty estimates can also inform further model development and measurement error evaluations in exposure and health studies.

Quality of life measured in first-line therapy during the Cryo-FIRST study: a comparison between cryoballoon catheter ablation versus antiarrhythmic drug therapy

Background

By consensus statements, catheter ablation is a recommended treatment for patients with symptomatic drug-refractory paroxysmal atrial fibrillation (AF), as patients try to alleviate the burdensome AF symptoms that reduce the Quality of Life (QoL). Yet, first-line treatment of symptomatic patients via catheter ablation prior to initiation of antiarrhythmic drugs (AADs) is only a reasonable alternative (Class IIa). Clearly, more clinical data is necessary that compares catheter ablation to AAD therapy in treatment naïve patients.

Purpose

The Cryo-FIRST trial was designed to compare AAD treatment against pulmonary vein isolation (PVI) while using a cryoballoon catheter (Arctic Front Advance; Medtronic, Inc.). This current data analysis examines the QoL endpoints when comparing AADs to cryoballoon ablation in patients with symptomatic treatment naïve paroxysmal AF.

Methods

This randomized multicenter trial enrolled 220 patients from 18 sites in 9 countries (Europe, Australia, and Latin America) in a prospective open-blinded endpoint study design. Patients had not been administered a class I or III AAD for longer than 48 hours for inclusion into the study. Subjects were randomized (1:1) into a cohort that was administered AAD therapy or a cohort that received PVI via cryoablation. The prespecified QoL endpoint at 12 months was measured using the Atrial Fibrillation Effect on Quality of Life (AFEQT) scores, and QoL recordings were taken at baseline, 1, 3, 6, 9, and 12 months following the index treatment.

Results

Of the 218 patients randomized (age 52±13 years, 68% male) 86% completed the 12-month follow-up. Crossovers occurred in 9% of subjects (N=20), including: 1 subject in the cryoablation arm and 19 subjects in the AAD arm. At 12 months, 86.5% of the patients in the cryoablation arm and 70.4% of the patients in the AAD arm where without symptoms (EHRA score 1). The mean AFEQT summary score was more favorable in the catheter ablation group compared to the drug therapy group at 12 months (88.9 vs. 78.1 points, respectively). The adjusted difference was 9.9 points (95% CI: 5.5–14.2; P&lt;0.0001).

Conclusions

Cryoballoon ablation resulted in a significant improvement in QoL at 12 months compared to AAD therapy in treatment naïve patients with first-line symptomatic paroxysmal AF.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Medtronic International Trading Sàrl

The Comprehensive Fire Information Reconciled Emissions (CFIRE) inventory: Wildland fire emissions developed for the 2011 and 2014 U.S. National Emissions Inventory

Wildland fire emissions from both wildfires and prescribed fires represent a major component of overall U.S. emissions. Obtaining an accurate, time-resolved inventory of these emissions is important for many purposes, including to account for emissions of greenhouse gases and short-lived climate forcers, as well as to model air quality for health, regulatory, and planning purposes. For the U.S. Environmental Protection Agency's 2011 and 2014 National Emissions Inventories, a new methodology was developed to reconcile the wide range of available fire information sources into a single coherent inventory. The Comprehensive Fire Information Reconciled Emissions (CFIRE) inventory effort utilized satellite fire detections as well as a large number of national, state, tribal, and local databases. The methodology and results for CONUS and Alaska were documented and compared against other fire emissions databases, and the efficacy of the overall effort was evaluated. Results show the overall spatial pattern differences and relative seasonality of wildfires and prescribed fires across the country. Prescribed burn emissions occurred primarily in non-summer months were concentrated in the Southeast, Northwest, and lower Midwest, and were relatively consistent year to year. Wildfire emissions were much more variable but occurred primarily in the summer and fall. Overall, CFIRE represents a third of total emitted PM2.5 across all sources in the National Emissions Inventory, with prescribed fires accounting for nearly half of all CFIRE emissions. Compared with other wildland fire emissions inventories derived solely from satellite detections, the CFIRE inventory shows markedly increased emissions, reflecting the importance of the multiple national and regional databases included in CFIRE in capturing small fires and prescribed fires in particular. Implications: Wildland fire emissions inventories need to incorporate multiple sources of fire information in order to better represent the full range of fire activity, including prescribed burns and smaller fires. For the 2011 and 2014 U.S. National Emissions Inventory, a methodology was developed to collect, associate, and reconcile fire information from satellite data as well as a large number of national, regional, state, local, and tribal fire information databases across the country. The resulting emissions inventory shows the importance of this type of integration and reconciliation when compared against other emissions inventories for the same period.

P993Incidence of atrial fibrillation early after cavotricuspid isthmus ablation

Background

Atrial fibrillation (AF) is a common finding in patients undergoing cavotricuspid isthmus ablation for isthmus dependent right atrial flutter (RAF). Little is known about the time of its occurrence.

Purpose

We aimed to investigate the incidence of AF early after RAF ablation in a well-defined, prospective cohort.

Methods

A total of 255 participants with RAF ablation from 5 centers and at least one completed follow-up were included. Structured clinical follow-up was performed at 3, 6 and 12 months including a 24 hour Holter-ECG. The endpoint was incidence of AF detected clinically or by Holter-ECG. Risk factors associated with the occurrence of AF were assessed using separate, univariate Cox proportional-hazards models.

Results

Mean age was 67 years, 80% were male and previous episodes of AF were known in 40%. Over a mean follow-up of 7.4 (±4.4) months AF was detected in 35 (13.7%) participants after RAF ablation (Figure A). After 3, 6 and 12 months AF was detected in 18 (7.1%), 30 (11.7%) and 34 (13.3%) patients. No difference in the incidence of AF after RAF ablation was found comparing patients with and without a history of AF (log-rank p value = 0.44) (Figure B). Comparing patients with and without AF during follow-up, there was no difference in age (68 vs 66 years, p = 0.36), sex (69 vs 81% male, p = 0.08), prior heart failure (29 vs 19%, p = 0.20), hypertension (43 vs 38%, p = 0.56) or left atrial volume (46.6 vs 39.6 ml, p = 0.10), but patients with previous AF had a lower left ventricular ejection fraction (LVEF) (45.7 vs 52.3%, p = 0.02). In separate, univariate Cox proportional-hazards models only increasing LVEF (Hazard ratio 0.97, 95% confidence interval (0.95; 0.99, p = 0.02)) was associated with a lower risk of incident AF after RAF ablation, but no other risk factor.

Conclusions

AF occurred in 13.7% of patients early after cavotricuspid isthmus ablation for RAF. There was no difference in the occurrence of AF between patients with and without previously known episodes of AF. Only impaired LVEF was associated with AF occurrence.

Abstract Figure

Spatiotemporal Imputation of MAIAC AOD Using Deep Learning with Downscaling

Aerosols have adverse health effects and play a significant role in the climate as well. The Multiangle Implementation of Atmospheric Correction (MAIAC) provides Aerosol Optical Depth (AOD) at high temporal (daily) and spatial (1 km) resolution, making it particularly useful to infer and characterize spatiotemporal variability of aerosols at a fine spatial scale for exposure assessment and health studies. However, clouds and conditions of high surface reflectance result in a significant proportion of missing MAIAC AOD. To fill these gaps, we present an imputation approach using deep learning with downscaling. Using a baseline autoencoder, we leverage residual connections in deep neural networks to boost learning and parameter sharing to reduce overfitting, and conduct bagging to reduce error variance in the imputations. Downscaled through a similar auto-encoder based deep residual network, Modern-Era Retrospective analysis for Research and Applications Version 2 (MERRA-2) GMI Replay Simulation (M2GMI) data were introduced to the network as an important gap-filling feature that varies in space to be used for missingness imputations. Imputing weekly MAIAC AOD from 2000 to 2016 over California, a state with considerable geographic heterogeneity, our full (non-full) residual network achieved mean R2 = 0.94 (0.86) [RMSE = 0.007 (0.01)] in an independent test, showing considerably better performance than a regular neural network or non-linear generalized additive model (mean R2 = 0.78-0.81; mean RMSE = 0.013-0.015). The adjusted imputed as well as combined imputed and observed MAIAC AOD showed strong correlation with Aerosol Robotic Network (AERONET) AOD (R = 0.83; R2 = 0.69, RMSE = 0.04). Our results show that we can generate reliable imputations of missing AOD through a deep learning approach, having important downstream air quality modeling applications.

Tool for decision-making regarding general evacuation during a rapid river flood

OBJECTIVES

To propose a simple and effective tool for decision-making regarding general evacuation during a rapid river flood.

STUDY DESIGN

Virtual testing of a tool in a real event.

METHOD

A four-component tool was applied to build an alternative scenario of the catastrophic river flood in Obrenovac, Serbia, on May 2014. The components of this tool are: (1) the amount of precipitation above the 95th percentile of all previous measurements; (2) upstream river discharge above the 95th percentile of all previous measurements; (3) upstream river level above the 95th percentile of all previous measurements; and (4) worsening of the hydrometeorological situation in the following 48 h.

RESULTS

In the early morning of 16 May 2014, a rapid river wave flooded 80% of the Obrenovac territory. There were 13 deaths due to drowning. Application of the study tool shows that these lives could have been saved, as the score to recommend general evacuation was reached 1 day before the flooding. The application of this tool to two previous great floods in Serbia shows that the score to recommend general evacuation was reached either 1 day before or on the onset of flash flooding.

CONCLUSIONS

Due to its simplicity, this tool is universally applicable to facilitate decision-making regarding general evacuation during a rapid river flood, and it should be further tested in future similar catastrophes.

Docking-based preliminary study on the interactions of bile acids with drugs at the transporter level in intestinal bacteria

OBJECTIVE

The aim of this study was to estimate the binding-affinities of different bile acids towards drug transporters in Lactobacillus acidophilus and Bifidobacterium longum in order to predict the influence of bile acids and probiotics interactions on drug pharmacokinetics.

MATERIALS AND METHODS

In order to study interactions of bile acids with transporters of intestinal bacteria, molecular-docking step was performed, using SwissDock web-service. For the purpose of comparison, two natural bile acids, cholic acid (CA) and deoxycholic acid (DCA), and one semi-synthetic bile acid, 12-monoketocholic acid (MKC), were studied in parallel. The free-binding energy was used as the main criterion for ranking ligands.

RESULTS

Studied bile acids exhibited different binding affinities towards bacterial transporters with MKC showing the most prominent effect. For the majority of studied transporters, the estimated affinities of bile acids decreased in the following order: MKC-CA-DCA. Namely, 38.7% of examined transport proteins gave the lowest free-binding energy with MKC. The weak inverse relationship between number of hydrogen bonds and estimated free-binding energies was revealed.

CONCLUSIONS

The predominant effect of MKC for the majority of studied transport proteins suggests that keto group at carbon 12 of the steroid core has a significant influence on the properties of MKC and consequently, on interactions with membrane transporters. Present findings might have a role in the prediction of potential influence of bile acids and probiotics on drug pharmacokinetics.

Analgesic effects of rosemary essential oil and its interactions with codeine and paracetamol in mice

OBJECTIVE

The use of herbal medicinal products in the management of pain has been increasing steadily in recent years, often in combination with conventional analgesics, which can induce significant interactions. In traditional medicine, rosemary was used as mild analgesic, for relieving renal colic pain and dysmenorrhea. The aim of our study was to examine analgesic effects of rosemary essential oil and its pharmacodynamic interactions with codeine and paracetamol in mice.

MATERIALS AND METHODS

The identification and quantification of chemical constituents of the essential oil isolated from air-dried aerial parts of rosemary were carried out by GC/FID and GC/MS. The hot plate test was performed on NMRI mice by placing them individually on hot plate and assessing their response to the thermal stimulus.

RESULTS

In this research, we identified 29 chemical compounds of the studied rosemary essential oil, and the main constituents were 1,8-cineole, camphor, and α-pinene. Administration of investigated essential oil increased significantly the latency time of animal response to heat-induced pain between 20th and 50th minute of the test, when compared to saline-treated group. Rosemary essential oil in the dose of 20 mg/kg was shown to be more efficient than in the dose of 10 mg/kg, in combinations with both codeine and paracetamol.

CONCLUSIONS

Our findings support the use of rosemary in the management of pain and indicate a therapeutic potential of rosemary essential oil in combination with analgesic drugs. The mechanisms involved in analgesic effects of rosemary essential oil and the potential influence on cytochromes and drug metabolism should be more in-depth investigated.

Balkan Endemic Nephropathy Risk Associates to the hs1.2 Ig Enhancer Polymorphism

Balkan Endemic Nephropathy (BEN) is a kidney degenerative disease with a high incidence in the valleys of the Danube and tributary rivers. Many studies describe it as a multifactorial disease. Environmental as well immuno-inflammatory and genetic cofactors have been suggested to trigger the onset of the disease. Recently, high levels of C-reactive protein were demonstrated in BEN patients. We performed this study to evaluate the possible correlation of BEN with the polymorphism of the Ig heavy chain 3'Regulatory Region enhancer hsl.2 that is related to changes of consensus for trans activators binding within the DNA sequence and probably consequently autoimmune and inflammatory diseases. Therefore, we studied three cohorts: 1) 111 control subjects, 2) 95 BEN patients in dialysis therapy and 3) 133 components of a large family “J” in the same geographical area. The allelic frequencies of hsl.2 of BEN patients and family “J” components had similar decrease frequency of allele *1 and increase of allele *2 in respect to the controls. This trend suggests the association of allele *1 as a protective and allele *2 as a risk component for the disease. The presence of a consensus sequence for NF-Kb in the allele *2 may link the polymorphism to the inflammatory activity of BEN. This study supports the presence of an inflammatory pathway in BEN through the involvement of polymorphic enhancer hsl.2 influencing differently binding complexes and consequently the 3D structure of 3' Regulatory Region of IgH. Our work is the first study that clearly links BEN to a gene involved in the regulation of immune response.

[Diurnal fluctuations of protein contents and the pH dependence of beta2-microglobulin stability in urine]

Diurnal fluctuations of protein excretion into urine and the effect of urinary pH on the urinary protein concentrations were studied in patients with various kidney diseases. The diurnal kinetics of gamma-immunoglobulin, transferrin, albumin, alpha1-microglobulin, gamma-immunoglobulin light chains, and the retinol-binding protein proved to positively correlate with the diurnal fluctuations of proteinuria and to negatively correlate with urinary pH. Diurnal changes in urinary beta2-microglobulin content did not correlate with those of any other protein. Oral bicarbonate intake alkalinized the urine, increased the urinary beta2-microglobulin content, and led to a direct correlation between beta2-microglobulin excretion and excretion of other low-molecular proteins. Thus, proteinuria, single protein excretion, and urinary pH displayed diurnal rhythmicity in the patients; beta2-microglobulin was unstable in acid urine and its urinary level depended on the urinary pH.

Green fluorescent protein-tagged sarco(endo)plasmic reticulum Ca2+-ATPase overexpression in Paramecium cells: isoforms, subcellular localization, biogenesis of cortical calcium stores and functional aspects

We have followed the time-dependent transfection of Paramecium cells with a vector containing the gene of green fluorescent protein (GFP) attached to the C-terminus of the PtSERCA1 gene. The outlines of alveolar sacs (ASs) are labelled, as is the endoplasmic reticulum (ER) throughout the cell. When GFP fluorescence is compared with previous anti-PtSERCA1 antibody labelling, the much wider distribution of GFP (ER+ASs) indicates that only a small amount of SERCA molecules is normally retained in the ER. A second isoform, PtSERCA2, also occurs and its C-terminal GFP-tagging results in the same distribution pattern. However, when GFP is inserted in the major cytoplasmic loop, PtSERCA1 and two fusion proteins are mostly retained in the ER, probably because of the presence of the overt C-terminal KKXX ER-retention signal and/or masking of a signal for transfer into ASs. On the overall cell surface, new SERCA molecules seem to be permanently delivered from the ER to ASs by vesicle transport, whereas in the fission zone of dividing cells ASs may form anew. In cells overexpressing PtSERCA1 (with C-terminal GFP) in ASs, [Ca2+]i regulation during exocytosis is not significantly different from controls, probably because their Ca2+ pump has to mediate only slow reuptake.

Microdomain arrangement of the SERCA-type Ca2+ pump (Ca2+-ATPase) in subplasmalemmal calcium stores of paramecium cells

We localized SERCA pumps to the inner region of alveolar sac membranes, facing the cell interior, by combining ultrastructural and biochemical methods. Immunogold labeling largely predominated in the inner alveolar sac region which displayed aggregates of intramembrane particles (IMPs). On image analysis, these represented oligomeric arrangements of approximately 8-nm large IMP subunits, suggesting formation of SERCA aggregates (as known from sarcoplasmic reticulum). We found not only monomers of typical molecular size ( approximately 106 kD) but also oligomeric forms on Western blots (using anti-SERCA antibodies, also against endogenous SERCA from alveolar sacs) and on electrophoresis gelautoradiographs of 32P-labeled phosphoenzyme intermediates. Selective enrichment of SERCA-pump molecules in the inner alveolar sac membrane region may eliminate Ca2+ after centripetal spread observed during exocytosis activation, while the plasmalemmal Ca2+ pump may maintain or reestablish [Ca2+] in the narrow subplasmalemmal space between the outer alveolar sac membrane region and the cell membrane. We show for the first time the microzonal arrangement of SERCA molecules in a Ca2+ store of a secretory system, an intensely discussed issue in stimulus-secretion coupling research.

Molecular characterization of a sarco(endo)plasmic reticulum Ca2+-ATPase gene from Paramecium tetraurelia and localization of its gene product to sub-plasmalemmal calcium stores

A cDNA encoding the gene for a sarco(endo)plasmic reticulum-type Ca2+-ATPase (SERCA) was isolated from a cDNA library of Paramecium tetraurelia by using degenerated primers according to conserved domains of SERCA-type ATPases. The identified nucleotide sequence (PtSERCA) is 3114 nucleotides in length with an open reading frame of 1037 amino acids. An intron of only 22 nucleotides occurs. Homology searches for the deduced amino acid sequence revealed 38-49% similarity to SERCA-type ATPases from organisms ranging from protozoans to mammals, with no more similarity to some parasitic protozoa of the same phylum. The calculated molecular mass of the encoded protein is 114.7 kDa. It contains the typical 10 transmembrane domains of SERCA-type ATPases and other conserved domains, such as the phosphorylation site and the ATP binding site. However, there are no binding sites for phospholamban and thapsigargin present in the PtSERCA. Antibodies raised against a cytoplasmic loop peptide between the phosphorylation site and the ATP binding site recognize on Western blots a protein of 106 kDa, exclusively in the fraction of sub-plasmalemmal calcium stores ('alveolar sacs'). In immunofluorescence studies the antibodies show labelling exclusively in the cell cortex of permeabilized cells in a pattern characteristic of the arrangement of alveolar sacs. When alveolar sacs where tested for phosphoenzyme-intermediate formation a phosphoprotein of the same molecular mass (106 kDa) could be identified.