Mathematical birth of Early Afterdepolarizations in a cardiomyocyte model

Early Afterdepolarizations (EADs) are abnormal behaviors that can lead to cardiac failure and even cardiac death. In this paper we investigate the occurrence and development of these phenomena in a reduced Luo-Rudy cardiac model. Through a comprehensive dynamical analysis, we map out the distinct patterns observed in the parametric plane, differentiating between normal beats without EADs and pathological beats with EADs. By examining the bifurcation structure of the model, we elucidate the dynamical elements associated with these patterns and their transitions. Using a fast-slow analysis, we explore the emergence and evolution of EADs in the model. Notably, our approach combines the two commonly used fast-slow approaches (1-slow-2-fast and 2-slow-1-fast), and we show how both approaches together provide a more complete understanding of this phenomenon.

Neonatal Dermatologic Findings in Uruguay: Epidemiology and Predisposing Factors

BACKGROUND

The skin is a fundamental organ in the transition from intrauterine to extrauterine life. The newborn infant experiences physiological changes and often presents benign, transient skin characteristics that vary according to maternal, gestational, and neonatal factors.

OBJECTIVES

To estimate the frequency of various dermatologic findings during the first 72hours of life and to identify their association with maternal, gestational, or neonatal factors.

METHODS

Descriptive, observational, cross-sectional study from April to July 2015 and July to November 2017 in the maternity ward of Centro Hospitalario Pereira Rossell. We examined the skin of neonates within 72hours of birth. Proportions and 95% CI were calculated for all findings. Associations between findings and factors were analyzed.

RESULTS

A total of 2811 neonates were included. We observed at least one neonatal skin finding in all of the neonates and found a median (interquartile range) of 8 (6-9) findings (minimum-maximum, 1-16). We observed 42 of the 46 possible characteristics we looked for; 99.9% of the findings were benign and transient. Among the findings were lanugo (98%; 95% CI, 97.7%-98.7%), physiological scaling (79.7%; 95% CI: 78.2%-81.1%), and sebaceous hyperplasia (73.3%; 95% CI: 71.6%-74.9%). Lanugo (P=.001), physiological scaling (P<.001), and erythema toxicum (P=.001) were observed significantly more often in full- and late-term neonates. Sebaceous hyperplasia (P=.001) and transient hyperpigmentation (P<.001) were found more often in newborn males. Erythema toxicum was more common after vaginal births (P=.008). Transient hyperpigmentation (P<.001) and dermal melanocytosis (P<.001) were seen more often in neonates of African descent.

CONCLUSIONS

All neonates have skin characteristics that are part of their adaptation to extrauterine life. Most are benign and transient. Maternal age, type of delivery, and certain neonatal factors such as gestational age, birth weight, sex, and ethnicity are associated with specific findings.

Potential Of High-Resolution Mass Spectrometry For The Detection Of Drugs And Metabolites In Hair: Methoxetamine In A Real Forensic Case

The analysis of drugs of abuse in hair and other biological matrices of forensic interest requires great selectivity and sensitivity. This is done traditionally through target analysis, with one or more analytical methods, or with different and specific preanalytical phases, and complex procedures performed by the toxicological laboratories, and there is no exception with ketamine-like compounds, such as methoxetamine, a new psychoactive substance (NPS) whose use has increased in the last decades, and continues to grow quickly year by year. More validated methods of analysis are needed to detect these substances in low concentrations selectively. Reanalyzing the samples of a former case of a polydrug consumer accused of a crime against public health in Spain, five metabolites of methoxetamine (normethoxetamine, O-desmethylmethoxetamine, dehydromethoxetamine, dihydronormethoxetamine and hydroxynormethoxetamine) were tentatively detected using a high-resolution technique that is liquid chromatography coupled to high-resolution mass spectrometry (LC-HR-MS/MS). The most selective analytical LC-HR-MS/MS method together a universal and simpler pretreatment stages has demonstrated to allow faster analysis and more sensitivity than the one performed traditionally at the INTCF laboratories, which was gas chromatography coupled to mass spectrometry (GC-MS).

Reconstruction of phthalate exposure and DINCH metabolites from biomonitoring data from the EXHES cohort of Tarragona, Spain: A case study on estimated vs reconstructed DEHP using the PBPK model

Phthalates are known endocrine disruptors (EDs) and are associated with potential diseases, such as obesity and diabetes. In 2002, the plasticizer 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) was introduced as an alternative to phthalates in the European market. The objective of this study was to evaluate the total exposure to phthalate and DINCH metabolites from EXHES Tarragona, Spain cohort of pregnant women. On the one hand, the analytical determination of phthalate and DINCH metabolites in urine was carried out. On the other hand, the reconstructed exposure was calculated for phthalates and DINCH using their metabolites concentration measured in the urine. Thirteen different phthalate metabolites and two metabolites of DINCH were measured and detected in almost all pregnant women's urine samples (n = 60). There were significant correlations between metabolites of the same parent compounds, and also between DEHP and MBzP metabolites, DiNP and BBZP metabolites, and DEHP and DiNP metabolites respectively. The exposure of pregnant women to phthalate and DINCH parent compounds were also back calculated using the levels of each metabolite found in pregnant women urine (reconstructed exposure). Besides, to demonstrate the utility of this approach, the physiologically based pharmacokinetic (PBPK) model was used to predict the cumulative amount of MEHP (a principal metabolite of DEHP in urine). To proceed with that, DEHP reconstructed exposure and estimated exposure from the same cohort (previously studied by the same authors) were simulated using the PBPK model. Results showed that the reconstructed-PBPK simulation was closer to the 24 h biomonitoring data than the estimated PBPK-simulation., This clearly shows that the combination of reconstructed exposure with the PBPK model is a good tool to predict chemicals exposure. However, some discrepancies between simulated and biomonitored values were found. This can be associated with other sources that contribute to the total exposure and emphasises the need to consider multi-routes exposure for the widely distributed chemicals like phthalates and DINCH.

Active commuting is associated with a lower risk of obesity, diabetes and metabolic syndrome in Chilean adults

Background

There is limited evidence on how active commuting is associated with health benefits in developing countries. The aim of this study therefore was to investigate the associations between active commuting and markers of adiposity and cardiometabolic risk in the Chilean adult population.

Methods

In total, 5157 participants from the Chilean National Health Survey 2009-10 were included in this cross-sectional study. Active commuting was measured using the Global Physical Activity Questionnaire (GPAQ v2). Body mass index (BMI) and waist circumference (WC) were measured and used to define obesity and central obesity. Type 2 diabetes (T2D) and metabolic syndrome were determined using WHO and updated ATPIII-NCEP criteria, respectively.

Results

The main finding of this study is that a 30 min increase in active commuting is associated with lower odds for BMI > 25.0 kg m-2 (0.93 [95% CI: 0.88-0.98, P = 0.010]). Similarly, the odds for central obesity was 0.87 [0.82-0.92, P < 0.0001]. Similar associations were found for T2D (0.81 [0.75-0.88], P < 0.0001) and metabolic syndrome (OR: 0.86 [0.80-0.92], P < 0.0001).

Conclusion

Our findings show that active commuting is associated with lower adiposity and a healthier metabolic profile including lower risk for obesity, diabetes and metabolic syndrome.

Performance of Young Children in Rural Guatemala on the Mullen Scales of Early Learning

Objective

The literature supports using tests developed in high-income countries to assess children in low and lower-middle income countries (LMICs) when carefully translated, adapted, and applied (Holding et al., 2018; Mitchell et al., 2017). Research has shown the Mullen Scales of Early Learning (MSEL) to have adequate validity and sensitivity when used in LMICs (Bangirana et al., 2014; Koura et al., 2013), as well as equivalency to the American normative sample in lower risk populations (Bornman et al., 2010). Here, we describe the pattern of MSEL results in rural Guatemala.

Participants and Method

Children (n = 842; M enrollment age = 15.9 months; range 0-5 years) enrolled in an observational study of postnatal Zika exposure in rural Guatemala were administered an adapted and translated version of the MSEL (Connery et al., in press). To date, 352 children completed one, 393 children completed two, and 97 children completed three MSELs, for a total of 1,429 administrations.

Results

MSEL composite scores were similar to the American normative sample in children &lt;12 months (M = 93.3, SD = 11.1), but lower for children ages 1-5 years (mean = 71.1, SD = 15.1, p &lt; 0.0001). Moreover, lower scores were observed in children ages 1-5 years for all MSEL subscales, with the largest differences observed in receptive language (&lt;12 years: mean = 47.8, SD = 7.1; 1-5 years: mean = 35.1, SD = 10.0, p &lt; 0.0001).

Conclusions

Results are consistent with research that demonstrates a widening gap in test performance over time between children from higher and lower risk communities (Fernald et al., 2011; Paxson et al., 2005; Schady et al., 2015). Although findings are not meant to diagnose individual children, they highlight population changes in neurodevelopmental skills and the need for a better understanding of developmental patterns in LMICs. Future analyses will evaluate the impact of developmental risk factors over time and the performance of the MSEL in this population.

References

Bangirana, P., Opoka, R. O., Boivin, M. J., Idro, R., Hodges, J. S., Romero, R. A., … John, C. C. (2014). Severe Malarial Anemia is Associated With Long-term Neurocognitive Impairment. Clinical Infectious Diseases, 59(3), 336–344. https://doi.org/10.1093/cid/ciu293. Bornman, J., Sevcik, R. A., Romski, M., & Pae, H. K. (2010). Successfully Translating Language and Culture when Adapting Assessment Measures, ppi_254 111.118. Retrieved from https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1741-1130.2010.00254.x. Fernald, L. C. H., Weber, A., Galasso, E., & Ratsifandrihamanana, L. (2011). Socioeconomic gradients and child development in a very low income population: Evidence from Madagascar. Developmental Science, 14(4), 832–847. https://doi.org/10.1111/j.1467-7687.2010.01032.x. Holding, P., Anum, A., van de Vijver, F. J. R., Vokhiwa, M., Bugase, N., Hossen, T., … Gomes, M. (2018). Can we measure cognitive constructs consistently within and across cultures? Evidence from a test battery in Bangladesh, Ghana, and Tanzania. Applied Neuropsychology: Child, 7(1), 1-13 https://doi.org/10.1080/21622965.2016.1206823. Koura, K. G., Boivin, M. J., Davidson, L. L., Ouédraogo, S., Zoumenou, R., Alao, M. J., … Bodeau-Livinec, F. (2013). Usefulness of child development assessments for low-resource settings in francophone Africa. Journal of Developmental and Behavioral Pediatrics : JDBP, 34(7), 486–93. https://doi.org/10.1097/DBP.0b013e31829d211c. Mitchell, J. M., Tomlinson, M., Bland, R. M., Houle, B., Stein, A., & Rochat, T. J. (2017). Confirmatory factor analysis of the Kaufman assessment battery in a sample of primary school-aged children in rural South Africa. South African Journal of Psychology, 1–19. https://doi.org/10.1177/0081246317741822. Paxson, C., Schady, N., Izquierdo, S., León, M., Lucio, R., Ponce, J., … Hall, W. (2005). Cognitive Development among Young Children in Ecuador The Roles of Wealth, Health, and Parenting. Retrieved from http://econ.worldbank.org. Schady, N., Behrman, J., Araujo, M. C., Azuero, R., Bernal, R., Bravo, D., … Vakis, R. (2015). Wealth gradients in early childhood cognitive development in five Latin American countries. The Journal of Human Resources, 50(2), 446–463. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/25983344.

Organochlorine pesticides air monitoring near a historical lindane production site in Spain

The landfilling and dumping of persistent organic pollutants (POPs) and other persistent hazardous chemicals, such as hexachlorocyclohexane (HCH) isomers can have significantly adverse environmental consequences and cause contamination in soil, water, and atmosphere systems. Approximately 115,000 t of HCH wastes were generated by INQUINOSA Factory located in Sabiñánigo (Aragón, Spain) from 1975 to 1992, and were mainly dumped at Bailín and Sardas landfills. Under the frame of the project plan approved by the Government of Aragón, remediation and containment measures were implemented at the derelict production facility and landfill sites. To protect and assess the local environment, the concentrations of HCH isomers, pentachlorobenzene (PeCB) and hexachlorobenzene (HCB) in air were periodically monitored in the Sardas landfills and surroundings by passive sampling devices. The influence of meteorological parameters was evaluated, showing positive correlations between temperature and HCH and HCB concentrations. The highest HCH levels were detected in Sardas landfill and INQUINOSA Factory sites. PeCB values were statistically higher in Sardas landfill than in Sabiñánigo urban core, nevertheless, HCB concentrations were similar in both sampling points. Statistically positive correlations were found among HCH isomers in all sampling points, showing a major common source. The chlorobenzenes also correlated positively with each other. The α-/γ-HCH ratios were calculated (1.46 ± 1.25; mean ± S.D.), corroborating that concentrations detected were mainly originated from the historical production, storage and waste disposal of technical HCH.

[Risk of cognitive impairment among older people with diabetes or family history of the disease]

BACKGROUND

Although cardiovascular risk factors are associated with an impaired cognitive function, the impact of diabetes on cognitive function in Chilean adults is unknown.

AIM

To investigate the association of diabetes or family history of the disease with cognitive impairment in older adults.

MATERIALS AND METHODS

Data from the 2009-2010 Chilean National Health Survey including 1,384 participants aged ≥ 60 years were included in this study. A score below 13 points for the Mini Mental State Examination (MMSE) was considered an indication of cognitive impairment. Logistic regression analyses were performed to assess the association between MMSE, diabetes and family history of the disease.

RESULTS

Cognitive impairment increased with age (Odds ratio (OR): 1.83 [95% confidence intervals (CI): 1.53; 2.19], p < 0.01, per 5 years increment in age). This trend was greater in individuals with diabetes (OR: 2.37 [95% CI: 1.68; 3.35], p < 0.01) compared to those without the disease. A similar trend was identified among individuals with a family history of diabetes compared to those without.

CONCLUSIONS

Older adults with diabetes are more susceptible to develop cognitive impairment.

Comparing dietary and non-dietary source contribution of BPA and DEHP to prenatal exposure: A Catalonia (Spain) case study

Bisphenol A (BPA) and Di-(2-ethylhexyl) phthalate (DEHP) are two wide spread chemicals classified as endocrine disruptors (ED). The present study aims to estimate the non-dietary (dermal, non-dietary ingestion and inhalation) exposure to BPA and DEHP for a pregnant women cohort. In addition, to assess the prenatal exposure for the fetus, a physiologically based pharmacokinetic (PBPK) model was used. It was adapted for pregnancy in order to assess the internal dosimetry levels of EDs (BPA and DEHP) in the fetus. Estimates of exposure to BPA and DEHP from all pathways along with their relative importance were provided in order to establish which proportion of the total exposure came from diet and which came from non-dietary exposures. In this study, the different oral dosing scenarios (dietary and non-dietary) were considered keeping inhalation as a continuous exposure case. Total non-dietary mean values were 0.002 µg/kg_bw/day (0.000; 0.004 µg/kg_bw/day for 5th and 95th percentile, respectively) for BPA and 0.597 µg/kg_bw/day (0.116 µg/kg_bw/day and 1.506 µg/kg_bw/day for 5th and 95th percentile, respectively) for DEHP. Indoor environments and especially dust ingestion were the main non-dietary contributors to the total exposure of BPA and DEHP with 60% and 81%. However, as expected, diet showed the higher contribution to total exposure with > 99.9% for BPA and 63% for DEHP. Although diet was considered the primary source of exposure to BPA and phthalates, it must be taken into account that with non-dietary sources the first-pass metabolism is lacking, so these may be of equal or even higher toxicological relevance than dietary sources. The present study is in the framework of "Health and environmental-wide associations based on large population surveys" (HEALS) project (FP7-603946).

[Association of physical inactivity with obesity, diabetes, hypertension and metabolic syndrome in the chilean population]

BACKGROUND

Physical inactivity is an important cardiovascular risk factor.

AIM

To investigate the association of physical inactivity with obesity, metabolic markers, type 2 diabetes mellitus, hypertension and metabolic syndrome in Chilean adults.

MATERIAL AND METHODS

Participants from the National Health Survey 2009-10 (n = 5,157) were included in this study. Body mass index, waist circumference, metabolic markers (blood glucose, glycosylated hemoglobin and lipid profile) were the outcomes. Type 2 diabetes, hypertension and metabolic syndrome were determined using international criteria. Physical activity levels were determined using the Global Physical Activity Questionnaire and physical inactivity was defined as < 600 METs/minutes/week.

RESULTS

Compared to their physically active peers, inactive men and women had a higher odds ratio (OR) for obesity (OR: 1.77 [95% confidence intervals (CI): 1.29-2.42], p < 0.01 and 1.25 [95% CI: 102-1.54], p < 0.035, respectively), diabetes (OR: 2.47 [1.80-3.38], p < 0.01 and 1.72 [1.35-2.19], p = 0.002, respectively) and hypertension (OR: 1.66 [1.31-2.09], p < 0.01 and 1.83 [1.54-2.18] respectively. An association of physical inactivity with central obesity and metabolic syndrome was observed only in men (OR: 1.92 [1.42- 2.58], p < 0.01 and 1.74 [1.23-2.47], p < 0.01, respectively).

CONCLUSIONS

Not meeting the physical activity recommendations is associated with obesity, diabetes, hypertension and metabolic syndrome, which are important cardiovascular risk factors.

Traditional and novel halogenated flame retardants in urban ambient air: Gas-particle partitioning, size distribution and health implications

Urban ambient air samples, including gas-phase (PUF), total suspended particulates (TSP), PM₁₀, PM_2.5 and PM₁ airborne particle fractions were collected to evaluate gas-particle partitioning and size particle distribution of traditional and novel halogenated flame retardants. Simultaneously, passive air samplers (PAS) were deployed in the same location. Analytes included 33 polybrominated diphenyl ether (PBDE), 2,2',4,4',5,5'-hexabromobiphenyl (BB-153), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane (DBDPE), dechloranes (Dec 602, 603, 604, 605 or Dechorane plus (DP)) and chlordane plus (CP). Clausius-Clapeyron equation, gas-particle partition coefficient (K_p), fraction partitioned onto particles (φ) and human respiratory risk assessment were used to evaluate local or long-distance transport sources, gas-particle partitioning sorption mechanisms, and implications for health, respectively. PBDEs were the FR with the highest levels (13.9pgm^-3, median TSP+PUF), followed by DP (1.56pgm^-3), mirex (0.78pgm^-3), PBEB (0.05pgm^-3), and BB-153 (0.04pgm^-3). PBDE congener pattern in particulate matter was dominated by BDE-209, while the contribution of more volatile congeners, BDE-28, -47, -99, and -100 was higher in gas-phase. Congener contribution increases with particle size and bromination degree, being BDE-47 mostly bounded to particles≤PM₁, BDE-99 to > PM₁ and BDE-209 to > PM_2.5. No significant differences were found for PBDE and DP concentrations obtained with passive and active samplers, demonstrating the ability of the formers to collect particulate material. Deposition efficiencies and fluxes on inhaled PBDEs and DP in human respiratory tract were calculated. Contribution in respiratory track was dominated by head airway (2.16 and 0.26pgh^-1, for PBDE and DP), followed by tracheobronchial (0.12 and 0.02pgh^-1) and alveoli (0.01-0.002pgh^-1) regions. Finally, hazard quotient values on inhalation were proposed (6.3×10^-7 and 1.1×10^-8 for PBDEs and DP), reflecting a low cancer risk through inhalation.

HCH air levels derived from Bailín dumpsite dismantling (Sabiñánigo, Spain)

Remediation and management of dumpsites is a worldwide problem that must be addressed to protect human health and the environment. Aragon Government long-term objective is the control of air quality related to landfills used to dump organochlorine waste. The present study evaluated the influence of dismantling works performed in Bailín landfill, an hexachlorocyclohexane (1,2,3,4,5,6-hexaclorohexane; HCH) dumpsite located in the city of Sabiñánigo, Spain. A total of 65,000 t of HCH solid waste and 342,000 t of polluted soil were transferred to a new cell with additional isolating measures going beyond the Spanish legal requirements. To evaluate influence of excavation of the old cell, transfer of waste and the state once the works in Bailín area had finished, levels of α-, β-, γ-, δ- and ɛ- HCH isomers were analyzed in 112 air samples obtained from summer 2014 to autumn 2016 by using passive air samplers. Results showed that: i) the existence of the old landfill and/or the works performed during its dismantling were a source of HCH air contamination, ii) old landfill represented an HCH source even after dismantling work was completed, iii) other sources, tentatively associated to Sardas dumpsite and HCH production site (INQUINOSA Factory) were identified in the surroundings, where management should be addressed. Data comparison reflected a heavier contamination caused by the production, storage, and waste disposal than the corresponding to application of lindane and/or technical HCH in Spain. Meteorological dependence (temperature, solar radiation and relative humidity), α-/γ-HCH ratios and isomer profiles of HCH air concentrations were evaluated for temporal trends and geographic distribution.

[Correlates of sedentary behaviors in Chile: evidence from the National Health Survey 2009-2010]

BACKGROUND

Sedentary behaviors are one of the major risk factors for cardiovascular diseases.

AIM

To identify factors associated with high sedentary behaviors in the Chilean population.

MATERIAL AND METHODS

We included 5,040 participants from the Chilean National Health Survey 2009-2010. Physical activity level and sedentary behavior (sitting time) were measured using the Global Physical Activity Questionnaire (GPAQ v2). Highly sedentary behaviors were determined as > 4 hours per day of sitting time. Logistic regression was used to identify correlates of highly sedentary behavior.

RESULTS

Forty seven percent of the study population reported spending more than 4 hours per day sitting. The prevalence was higher in women. The main factors associated with high sedentary behavior were: high income levels (Odds ratio (OR):1.91 [95% Confidence intervals (CI:1.61-2.27]); being woman (OR:1.39 [95% CI:1.24-1.56]): having central obesity (OR:1.15 [95% CI:1.02-1.30]), being physically inactive (OR:2.35 [95% CI:2.06-2.68]), and living in an urban area (OR:1.92 [95% CI:1.63-2.26]). Other factors associates with high sedentary behavior were: being smoker, having a television set, computer and private car at their homes. Participants reporting a poor self-reported health and wellbeing and those with diabetes or metabolic syndrome were more likely to be highly sedentary.

CONCLUSIONS

The main factors associated with high levels of sedentary behavior are socio-demographic issues, lifestyles and health status.

Gas/particle partitioning and particle size distribution of PCDD/Fs and PCBs in urban ambient air

Urban ambient air samples, including gas-phase (PUF), total suspended particulates (TSP), PM₁₀, PM_2.5 and PM₁ airborne particle fractions were collected to evaluate gas-particle partitioning and size particle distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). Clausius-Clapeyron equation, regressions of logKp vs logP_L and logK_OA, and human respiratory risk assessment were used to evaluate local or long-distance transport sources, gas-particle partitioning sorption mechanisms, and implications for health. Total ambient air levels (gas phase+particulate phase) of TPCBs and TPCDD/Fs, were 437 and 0.07pgm^-3 (median), respectively. Levels of PCDD/F in the gas phase (0.004-0.14pgm^-3, range) were significantly (p<0.05) lower than those found in the particulate phase (0.02-0.34pgm^-3). The concentrations of PCDD/Fs were higher in winter. In contrast, PCBs were mainly associated to the gas phase, and displayed maximum levels in warm seasons, probably due to an increase in evaporation rates, supported by significant and strong positive dependence on temperature observed for several congeners. No significant differences in PCDD/Fs and PCBs concentrations were detected between the different particle size fractions considered (TSP, PM₁₀, PM_2.5 and PM₁), reflecting that these chemicals are mainly bounded to PM₁. The toxic content of samples was also evaluated. Total toxicity (PUF+TSP) attributable to dl-PCBs (13.4fg-TEQ₀₅ m^-3, median) was higher than those reported for PCDD/Fs (6.26fg-TEQ₀₅ m^-3). The inhalation risk assessment concluded that the inhalation of PCDD/Fs and dl-PCBs pose a low cancer risk in the studied area.