95th Percentile Research Articles

Transcriptomic Point of Departure (tPOD) of androstenedione in zebrafish embryos as a potential surrogate for chronic endpoints

The transcriptomic Point of Departure (tPOD) is increasingly used in ecotoxicology to derive quantitative endpoints from RNA sequencing studies. Utilizing transcriptomic data in zebrafish embryos as a New Approach Methodology (NAM) is beneficial due to its acknowledgment as an alternative to animal testing under EU Directive 2010/63/EU. Transcriptomic profiles are available in zebrafish for various modes of action (MoA). The limited literature available suggest that tPOD values from Fish Embryo Toxicity (FET) tests align with, but are generally lower than, No Observed Effect Concentrations (NOEC) from long-term chronic fish toxicity tests.In studies with the androgenic hormone androstenedione in a Fish Sexual Development Test (FSDT), a significant shift in the sex ratio towards males was noted at all test concentrations, making it impossible to determine a NOEC (NOEC <4.34 μg/L). To avoid additional animal testing in a repetition of the FSDT and adhere to the 3Rs principle (replacement, reduction, and refinement), a modified zebrafish FET (zFET) was conducted aiming to determine a regulatory acceptable effect threshold. This involved lower concentration ranges (20 to 6105 ng/L), overlapping with the masculinization-observed concentrations in the FSDT. The tPOD analysis in zFET showed consistent results with previous FSDT findings, observing strong expression changes in androgen-dependent genes at higher concentrations but not at lower ones, demonstrating a concentration-response relationship.The tPOD values for androstenedione were determined as 24 ng/L (10th percentile), 60 ng/L (20th gene), and 69 ng/L (1st peak). The 10th percentile tPOD value in zFET was 200 times lower than the lowest concentration in the FSDT. Comparing the tPOD values to literature suggests their potential to inform on the NOEC range in FSDT tests.

A time-stratified, case-crossover study of heat exposure and perinatal mortality from 16 hospitals in sub-Saharan Africa.

Growing evidence suggests that extreme heat events affect both pregnant women and their infants, but few studies are available from sub-Saharan Africa. Using data from 138,015 singleton births in 16 hospitals in Benin, Malawi, Tanzania and Uganda, we investigated the association between extreme heat and early perinatal deaths, including antepartum and intrapartum stillbirths, and deaths within 24 h after birth using a time-stratified case-crossover design. We observed an association between an increase from the 75th to the 99th percentile in mean temperature 1 week (lag 0-6 d) before childbirth and perinatal mortality (odds ratio (OR) = 1.34 (95% confidence interval (CI) 1.01-1.78)). The estimates for stillbirths were similarly positive, but CIs included unity: OR = 1.29 (95% CI 0.95-1.77) for all stillbirths, OR = 1.18 (95% CI 0.71-1.95) for antepartum stillbirths and OR = 1.64 (95% CI 0.74-3.63) for intrapartum stillbirths. The cumulative exposure-response curve suggested that the steepest slopes for heat for intrapartum stillbirths and associations were stronger during the hottest seasons. We conclude that short-term heat exposure may increase mortality risks, particularly for intrapartum stillbirths, raising the importance of improved intrapartum care.

Lung densitometry in postmortem computed tomography - comparison across different fatal asphyxia groups.

Asphyxia as a cause of death poses a diagnostic challenge in forensic medicine due to both the diversity of underlying mechanisms, and lack of specific markers. Acute emphysema or acute alveolar dilation have long been debated as potential findings in these asphyxia cases. To further explore the supplementary findings in our forensic asphyxia cases, this study applied lung densitometry to pulmonary postmortem computed tomography (PMCT) data. Twenty asphyxia cases (including hanging (n = 9), manual strangulation (n = 4), ligature strangulation (n = 1), smothering (n = 3), and choking (n = 3)) and 21 matched control cases were analysed using lung densitometry parameters - specifically quantification of low attenuation areas (LAA) and the 15th percentile point of lung density (Perc15). Our data revealed statistically significantly higher lung % volume falling within LAA at -950HU (p = 0.04) and - 910HU (p = 0.043) in the asphyxia cases compared to matched controls. The Perc15 values observed were trending towards a lower attenuation corresponding to a lower density in the asphyxia group, although this result was not statistically significant (p = 0.13). A subgroup analysis highlighted potential differences within the asphyxia categories, notably, higher Perc15 values were observed in the choking cases. In conclusion the results from the study support the existing evidence of low pulmonary density as a potential finding in asphyxia cases and demonstrate the potential of applying lung densitometry on pulmonary postmortem computed tomography data.

Sex-specific high-sensitivity troponin T cut-points have similar safety but lower efficacy than overall cut-points in a multisite U.S. cohort.

Data comparing the performance of sex-specific to overall (non-sex-specific) high-sensitivity cardiac troponin (hs-cTn) cut-points for diagnosing acute coronary syndrome (ACS) are limited. This study aims to compare the safety and efficacy of sex-specific versus overall 99th percentile high-sensitivity cardiac troponin T (hs-cTnT) cut-points. We conducted a secondary analysis of the STOP-CP cohort, which prospectively enrolled emergency department patients ≥ 21 years old with symptoms suggestive of ACS without ST-elevation on initial electrocardiogram across eight U.S. sites (January 25, 2017-September 6, 2018). Participants with both 0- and 1-h hs-cTnT measures less than or equal to the 99th percentile (sex-specific 22 ng/L for males, 14 ng/L for females; overall 19 ng/L) were classified into the rule-out group. The safety outcome was adjudicated cardiac death or myocardial infarction (MI) at 30 days. Efficacy was defined as the proportion classified to the rule-out group. McNemar's test and a generalized score statistic were used to compare rule-out and 30-day cardiac death or MI rates between strategies. Net reclassification improvement (NRI) index was used to further compare performance. This analysis included 1430 patients, of whom 45.8% (655/1430) were female; the mean ± SD age was 57.6 ± 12.8 years. At 30 days, cardiac death or MI occurred in 12.8% (183/1430). The rule-out rate was lower using sex-specific versus overall cut-points (70.6% [1010/1430] vs. 72.5% [1037/1430]; p = 0.003). Among rule-out patients, the 30-day cardiac death or MI rates were similar for sex-specific (2.4% [24/1010]) vs. overall (2.3% [24/1037]) strategies (p = 0.79). Among patients with cardiac death or MI, sex-specific versus overall cut-points correctly reclassified three females and incorrectly reclassified three males. The sex-specific strategy resulted in a net of 27 patients being incorrectly reclassified into the rule-in group. This led to an NRI of -2.2% (95% CI -5.1% to 0.8%). Sex-specific hs-cTnT cut-points resulted in fewer patients being ruled out without an improvement in safety compared to the overall cut-point strategy.

PREVENTION OF FETAL GROWTH RETARDATION

Fetal growth restriction (FGR) has been a frequently encountered pathology in obstetrics and affects 5-10% of pregnancies. It has been one of the three main causes of perinatal deaths, after premature births and fetal malformations. In approximately one third of cases with FGR, cause or pathology was not found, which made it difficult to prevent or treat them effectively. Mostly, FGR was a consequence of insufficiency of uteroplacental circulation, placental and fetoplacental function. The term SGA (small for gestational age) has to do with constitutional growth rates and the statistical determination within which the newborn is considered smaller for gestational age. Whereas the term FGR (fetal growth retardation) refers to delayed growth below the 10th percentile as a pathological phenomenon. The current management of FGR consists of fetal surveillance to detect a decline in the baby’s health and deliver when this can be safely done. Therefor Doppler ultrasound was considered the chosen technique. The use of low-dose aspirin for preventing FGR and preeclampsia (PE) has been one of the most important research topics for the last 10 years. Several national protocols recommend the treatment with low-dose aspirin (100-150mg daily) for high-risk pregnancies, starting around 12-16 weeks of gestation. It favors placentation by its proangiogenic, antithrombotic and anti-inflammatory effects.

The heat-mortality association in Jordan: Effect modification by greenness, population density and urbanization level

BackgroundThe Middle East is one of the most vulnerable regions to the impacts of climate change, yet evidence of the heat-related mortality remains limited in this area. Our present study investigated the heat-mortality association in Jordan and the potential modifying effect of greenness, population density and urbanization level on the association. MethodsFor each of the 42 included districts, daily meteorological and mortality data from 2000 to 2020 were obtained for the warmest months (May to September). First, a distributed lag non-linear model was applied to estimate the district level heat-mortality association, then the district specific estimates were pooled using multivariate meta-regression models to obtain an overall estimate. Last, the modifying effect of district level greenness, population density and urbanization level was examined through subgroup analysis. ResultsWhen compared to the minimum mortality temperature (MMT, percentile 0th, 22.20 °C), the 99th temperature percentile exhibited a relative risk (RR) of 1.34 (95 % CI 1.23, 1.45). Districts with low greenness had a higher heat-mortality risk (RR 1.39, 95 % CI 1.22, 1.58) when compared to the high greenness (RR 1.28, 95 % CI 1.13, 1.45). While heat-mortality risk did not significantly differ between population density subgroups, highly urbanized districts had a greater heat-mortality risk (RR 1.41, 95 % CI 1.23, 1.62) as compared to ones with low levels of urbanization (RR 1.32, 95 % CI 1.13, 1.55). Districts with high urbanization level had the highest heat-mortality risk if they were further categorized as having low greenness (RR 1.63, 95 % CI 1.30, 2.04). ConclusionExposure to heat was associated with increased mortality risk in Jordan. This risk was higher in districts with low greenness and high urbanization level. As climate change-related heat mortality will be on the rise, early warning systems in highly vulnerable communities in Jordan are required and greening initiatives should be pursued.

Analysis of Head Movement in KPSIT Dummies and the Impact of Seats and Seat Belts during Low-Speed Collisions 20 km/h.

The aim of this study was to compare the head displacement of the KPSIT C50 dummy, representing a 50th percentile male, with the KPSIT C5 dummy, representing a 5th percentile female, during low-speed collisions. Low-speed collisions, such as those occurring in urban traffic jams, are increasingly common. The research was conducted on a dedicated educational workstation designed to measure forces in seat belts. This study is part of a comprehensive research project on crash tests involving both volunteers and physical KPSIT dummies. The tests were conducted at a speed of 20 km/h to simulate real-world low-speed collision scenarios. The findings demonstrate that using a sports bucket seat with four-point or five-point harnesses significantly reduces head displacement compared with standard car seats. Such seating configurations enhance safety by minimizing the risk of head injuries, which can occur when airbags do not deploy during low-speed collisions. Moreover, the study highlights that standard three-point seat belts allow for greater forward head movement, increasing the risk of head contact with the vehicle's interior during collisions at speeds too low to trigger airbag deployment.

Bioaccessibility of plastic-related compounds from polymeric particles in marine settings: Are microplastics the principal vector of phthalate ester congeners and bisphenol A towards marine vertebrates?

Marine vertebrates are known to ingest significant amounts of microplastics (MPs). Once ingested, MPs might cause gastrointestinal injuries and serve as a path of harmful plastic components, such as phthalate esters (PAEs) and bisphenol A (BPA) in the food chain. However, there is a lack of standardized in-vitro methods capable of simulating fish uptake of chemicals from MPs in the environment as potential vectors of such contaminants. In this work, leaching and in-vitro oral bioaccessibility testing of PAEs and BPA from MPs were conducted batchwise using artificial seawater and gut fluids mimicking gastric, intestinal, and gastrointestinal compartments of marine vertebrates at physiological temperature. The environmental and physiologically relevant extraction tests were applied to medium-density polyethylene (PE) and polyvinyl chloride (PVC) certified reference materials containing eight PAEs of varying hydrophobicity, namely, dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate, benzylbutyl phthalate, diethylhexyl phthalate, di-n-octyl phthalate, diisononyl phthalate and diisodecyl phthalate, and BPA (only in PE) as MP surrogates with realistic analyte concentrations for primary MPs. The analysis of the leachates/gut fluid extracts was performed via dilute-and-shoot by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Only the most hydrophilic compounds, i.e. DMP, DEP and BPA, were found to get released significantly in saline waters, and exhibited the highest oral bioaccessibility rates (34–83 %). Based on our results, a dual-compartment physiologically relevant gastrointestinal test is recommended for appropriate estimation of fish bioaccessibility. The fish daily intakes of DMP, DEP and BPA from MPs, and seawater ingestion as well were estimated using several contamination scenarios (10th percentile as low level, 50th percentile as medium level and 90th percentile as high level contamination) based on probabilistic distributions and cumulative probability curves of measured environmental concentrations of (i) MP in seawater throughout the world, (ii) DMP, DEP and BPA in beached MP and those sampled in the open ocean (including both incurred and adsorbed contaminants), and (iii) DMP, DEP and BPA in seawater as reported in recent literature. Under a medium-level concentration scenario (50th percentile) in marine settings, and taking the gastrointestinal bioaccessibility factor into account, the daily intake of DMP, DEP and BPA from MPs accounted for a mere 0.02 % of the waterborne contribution. Hence, the ingestion of MPs should not be considered the primary route of fish exposure to BPA and the most polar PAEs in marine environments. However, more studies on the local and global scales using the continuously available data in the literature for mass concentrations of MP and additives in marine settings are needed for further confirmation of our findings.

205 Hidden benefits in non-effective interventions: A subgroup analysis of associations between characteristics of study participants and changes in prolonged sedentary time using compositional data analysis

Abstract Purpose Interventions aiming to increase physical activity (PA) or reduce sedentary time (ST) often suffer from selection bias of highly active individuals. Subgroup analysis among most sedentary participants may reveal information about beneficial behaviour changes beyond non-significant intervention effects. We aimed to identify characteristics of participants of a non-effective intervention study associated with a reduction of time spent in prolonged sedentary bouts using compositional data analysis (CoDA) in a subsample of those with highest baseline bout levels. Methods Data was used from an intervention study aiming to increase PA and reduce ST via brief feedback letters among adults from the general population aged ≥65 years. Participants wore ActiGraph-accelerometers on the hip during waking hours for seven days at baseline and 12-months follow-up (N = 130). We conducted a subgroup analysis among participants of the upper half of the distribution of ST spent in &amp;gt; 30min-bouts (i.e., median split at 2.6h/day; n = 69). CoDA was used to build a z1 coordinate representing the change in ST spent in &amp;gt; 30min-bouts, relative to the change of time spent in PA and in ≤ 30min-ST-bouts. Quantile regressions were used to investigate associations of age, sex, partnership, baseline waist circumference (WC), and baseline &amp;gt;30min-ST-bouts with z1 on percentiles 25, 50, and 75 of the z1 distribution. Results Participants were aged 72±5.1 years, 61% were female, 74% lived with a partner, and baseline WC was 91±12.8 cm in women and 101±11.6 cm in men. At baseline (and follow-up), individuals spent 26% (25%) of time in &amp;gt; 30min-ST-bouts, 37% (38%) in PA, and 37% (37%) in ≤ 30min-ST-bouts. At the 25th percentile, female sex and higher WC were predictive for a higher reduction of &amp;gt; 30min-ST-bouts (ps&amp;lt;.05). Conclusions In a non-effective intervention, among those with highest baseline levels (&amp;gt;2.6h/day) and highest reduction of prolonged ST (25th percentile), females and those with higher baseline WC reduced prolonged ST more than males and those with lower baseline WC. Intervention studies without significant efficacy may yield valuable information about individuals who showed beneficial behaviour changes. Funding Source Federal Ministry of Education and Research (BMBF) as a site project of the German Centre for Cardiovascular Research (no. 81Z7400174)

Trends in extreme rainfall and their relationship to flooding episodes in Vhembe district, South Africa

Extreme weather events, such as heavy rainfall, are being increased by climate change in various regions, and such events often cause floods. This study examined the trends and variability of extreme rainfall indices using daily rainfall data (1981–2023) from three study sites at different socio-economic development spectra in Vhembe District, Limpopo Province, South Africa. The analyses focus on indices such as the annual total rainfall from wet days (PRCPTOT), the maximum number of consecutive dry days (CDD) and wet days (CWD), annual maximum 1-day and 5-day rainfall (RX1 day and RX5 day), the Simple Daily Intensity Index (SDII), the number of days exceeding varying amounts of precipitation (R10, R20, R40) and the annual number of wet days with rainfall greater than the 95th and 99th percentile (R95p and R99p) of the 1981–2023 daily rainfall. We discuss the observed trends in extreme rainfall indices in light of the actual flood occurrences to establish linkages. Several statistically significant and marginal changes in extreme rainfall trends were identified and provided key insights into reported flooding events in the district—flooding episodes were mainly attributed to the significant increases in total precipitation (PRCPTOT) and rainfall exceeding the 99th percentile of daily rainfall (R99p). Other significant contributors were declining CDD and increasing RX1day at Duthuni, increasing R40 at Musina as well as increasing R1 and declining CDD at Sane. However, the low altitude, urbanization, poor waste management and inadequate drainage systems were among the key non-climatic drivers of flood risk across the study sites, but these warrant further investigation. The complex interplay between climatic and non-climatic drivers of flood risk underscores the importance of localized climate studies and the need for adaptive strategies to minimize loss and damage. Overall, this research provides valuable insights into localized extreme rainfall trends, which are essential for developing site-specific flood mitigation and adaptation strategies. However, such initiatives require placing vulnerable communities at the centre in order to develop solutions that are locally led and relevant.

Intrinsic short Marine Heatwaves from the perspective of sea surface temperature and height

Marine heatwaves (MHWs) have recently been recognized as extreme climate events considering their devastating impacts on marine ecosystems. Our study explored the spatial and temporal variability of short (duration < 10 days) and long MHWs in nine sub-regions around the Australian coastal region using the original (5-day) and an updated longer duration (10-day) criteria for MHW identification based on gap-free Sea Surface Temperature (SST) analyses from 1981 to 2020. By quantitatively investigating the contribution of ocean warming to short MHWs, we could consider most of the short events as background signals of a dynamic ocean surface over the Australian region. The application of the updated definition highlights areas that are more sensitive to local internal forcings, especially over the main flow of the East Australian Current. Furthermore, the Great Barrier Reef exhibit a larger increasing trend of MHW areas after excluding the short events. By numerically and graphically evaluating the relationship between the sea level anomaly (SLA) and SST metrics over two coastal regions of Australia, it is found that longer MHWs exhibiting two variation trends of large SLA metrics are ENSO dominant in the northwest coastal region (NW), and less ENSO-dominant but geographically-impacted in the southeast coastal region (SETS). However, it is possible that most short events in these two regions are a result of local and intrinsic variability or ocean warming of the water columns rather than the remote modulation of climate modes. Moreover, SLA over the 90th percentile, which successfully observed a subsurface MHW event over the NW region in 2008, has the potential to help identify subsurface MHWs, although limited by application area. Further investigation into the applicability of these, or other similar, updates to the MHW definitions may be warranted, to draw a broadly applicable conclusion to benefit detection and prediction of strong sub-surface MHWs impacting commercial and environmental activities.

Healthcare Policy and Arthroscopic Rotator Cuff Repair Prices in the United States

BackgroundArthroscopic rotator cuff repair (ARCR) is one of the most common orthopedic procedures in the general population. Despite its prevalence, the price of ARCR varies significantly across regions, hospital models, and settings. The purpose of this study was to examine the effect of Geographic Region, Certificate of Need (CON) laws, and Medicaid expansion on ARCR pricing. MethodsThis cross-sectional observational study utilized hospital payer-specific ARCR prices from the Turquoise Health Database using CPT code 29827. These prices are negotiated rates or charges that hospitals establish with various payers, including insurance companies, Medicare, Medicaid, and self-pay patients, for medical services and treatments provided. Outliers below the 10th percentile and above the 90th percentile were excluded. State policies, including CON status and Medicaid expansion, were obtained from public sources, while additional socioeconomic and demographic data were sourced from the US Census. The state's region classification was determined based on one of four Geographic Regions defined by the US Census Bureau. A detailed analysis was also conducted for North Carolina, examining county-level data on urbanization and the Area Deprivation Index (ADI). ResultsThere were 57,270 ARCR prices from 2,503 hospitals across the United States, with a median interquartile range (IQR) listed price of $6,428.17 (IQR: $2,886.88). States with CON regulations had significantly lower ARCR prices compared to those without ($6,500 vs. $8,000, p<0.0001). Multivariable analysis indicated that hospitals in the Northeast and West Regions listed significantly higher prices for ARCR compared to those in the Midwest Region (p<0.0001). In contrast, hospitals in the South Region listed lower prices for ARCR compared to those in the Midwest Region (p<0.0001). Medicaid expansion was associated with increased ARCR prices (p<0.0001), while CON laws were linked to reduced prices (p< .0001). In North Carolina, ADI and urbanization status did not significantly affect ARCR prices. ConclusionThe prices listed for ARCR varied significantly depending on the Geographic Region where hospitals were located. Additionally, CON laws were associated with reduced ARCR prices, while Medicaid expansion correlated with increased prices. These findings highlight the complex interplay between healthcare policy, regulatory frameworks, and socioeconomic factors in determining surgical prices.

Differentiation of solid and friable tumour thrombus in patients with renal cell carcinoma: The role of MRI apparent diffusion coefficient

PurposeInferior vena cava (IVC) involvement by renal cell carcinoma (RCC) is associated with a higher disease stage and is considered a risk factor for poor prognosis. This study aimed to investigate the role of the apparent diffusion coefficient (ADC) of MRI 3D texture analysis in the differentiation of solid and friable tumour thrombus in patients with RCC. Materials and methodsThe study involved 27 patients with RCC with tumour thrombus in the renal vein or IVC, surgically treated with nephrectomy and thrombectomy and in whom preoperatively abdominal MRI including the DWI sequence was conducted. For 3D texture analysis, the ADC map was used, and the first-order radiomic features were calculated from the whole volume of the thrombus. All tumour thrombi were histologically classified as solid or friable. ResultsThe solid and friable thrombus was detected in 51.9 ​% and 48.1 ​% of patients, respectively. No differences in mean values of range, 90th percentile, interquartile range, kurtosis, uniformity and variance were found between groups. Equal sensitivity and specificity (93 ​% and 69 ​%, respectively) of ADC mean, median and entropy in differentiation between solid and friable tumour thrombus, with the highest AUC for entropy (0.808), were observed. Applying the skewness threshold value of 0.09 allowed us to achieve a sensitivity of 86 ​% and a specificity of 92 ​%. ConclusionsIn patients with RCC and tumour thrombus in the renal vein or IVC, the 3D texture analysis based on ADC-map allows for precise differentiation of a solid from a friable thrombus.

Geriatric conditions and invasive management in frail patients with NSTEMI. A subgroup analysis of a randomized clinical trial

Introduction and objectivesInvasive management in frail patients with non–ST-segment elevation myocardial infarction (NSTEMI) remains controversial. We investigated the impact of various geriatric conditions. MethodsThe MOSCA-FRAIL trial included 167 adults aged ≥ 70 years with frailty (Clinical Frailty Scale [CFS] ≥ 4 points) and NSTEMI, who were randomized to either an invasive (n=84) or conservative (n=83) strategy. In addition to frailty, we measured activities of daily living (Barthel index), cognitive impairment (Pfeiffer test), and comorbidities (Charlson index). The primary endpoint was the difference (invasive minus conservative) in restricted mean survival time (RMST) for all-cause mortality at a median follow-up of 3.9 years. ResultsA total of 93 patients died. The RMST difference favored invasive management at the CFS 25th percentile (CFS=4; 157 days, 95%CI, 18-295; P=.027), which changed to a nonsignificant effect at the 50th and 75th percentiles. The RMST difference remained nonsignificant, irrespective of the severity of other geriatric assessments. In time-to-event analysis, invasive management was associated with an initially lower life expectancy, peaking at around 1 year, among all subgroups. However, patients with CFS=4 experienced a benefit at the end of follow-up (181 days, 95%CI, 19-343), whereas those with CFS >4 did not (−16 days, 95%CI, −217 to 186; interaction P=.16). Subgroups defined by other geriatric markers showed a similar time-dependent trend, albeit with weaker statistical interaction. ConclusionsAmong adults with frailty and NSTEMI, the CFS might be useful for evaluating the relative risks and benefits of invasive management. A CFS >4 could serve as a valuable threshold for decision-making.

Associations between single and combined exposures to environmental phenols and ulcerative colitis in American adults

ObjectiveThe etiology of ulcerative colitis (UC) is complex and involves multiple factors, with exposure to environmental toxins potentially contributing greatly to its pathogenesis. Therefore, this study was carried out with the purpose of delving into the associations between single and combined exposures to environmental phenols and UC among American adults. MethodsSurvey data from the 2009–2010 National Health and Nutrition Examination Survey were selected for our research. The associations between single and combined exposures to environmental phenols and the prevalence of UC were analyzed using weighted multivariate logistic regression models as well as Bayesian kernel machine regression (BKMR). ResultsA total of 1,422 adults aged 20 years old and above were included in this study, 17 of whom had UC. The correlation matrix showed strong associations between 2,4-dichlorophenol (2,4-DCP) and 2,5-dichlorophenol (2,5-DCP) (R = 0.81), as well as between 2,4,5-trichlorophenol (2,4,5-TCP) and 2,4,6-trichlorophenol (2,4,6-TCP) (R = 0.73). The logistic regression model revealed that, after adjusting for confounders, exposure to environmental phenols was positively associated with the prevalence of UC, with 2,4,6-TCP showing a significant association (OR = 2.37, 95% CI = 1.10, 5.09, P = 0.037). The BKMR analysis indicated an upward trend in the overall effect of combined exposures to environmental phenols on UC. All five phenols contributed to this effect, with 2,4,6-TCP exhibiting the most pronounced effect. When other compounds were fixed at the 50th percentile, the impact of the five phenols on UC demonstrated a positive association, without any noteworthy interaction among the compounds. ConclusionOur findings suggested that exposure to environmental phenols may contribute to the occurrence of UC among American adults.

Estimating the validity of Tanaka–Johnston and Moyer’s analysis of a Saudi sample

OBJECTIVES: Accurate estimation of unerupted permanent canines and premolars is a crucial step for effective orthodontic treatment planning during mixed dentition. This study aimed to evaluate the validity of Moyers’ charts and the Tanaka–Johnston equation in predicting tooth sizes in a sample of the Madina population in Saudi Arabia and propose a new regression equation. METHODS: Dental casts from 219 subjects (113 males and 106 females) were analyzed. Actual mesiodistal tooth widths were measured using digital calipers with an accuracy of 0.01 mm. Moyers’ and Tanaka–Johnston predictions were compared with actual measurements, and a new set of prediction equations was developed. RESULTS: Tanaka–Johnston predictions consistently overestimated the actual measurements, exhibiting a difference of 1.20 mm for maxillary canines and premolars and a difference of 1.25 mm for mandibular teeth. The Moyers chart showed gender-specific variations with males aligning with the 50th percentile and females aligning with the 65th percentile for upper arches and the 50th percentile for lower arches. Newly derived linear regression equations were established for predicting the sum of upper and lower canines and premolars for the Madina population. CONCLUSION: The study highlights limitations in the Moyers and Tanaka–Johnston methods used for the current sample as both methods overestimated tooth sizes. New regression equations were developed to offer a more accurate approach for predicting tooth sizes for the study sample.

Study on the characteristics of urban background ozone pollution based on long-term observations from mountain sites in China during 2015–2022

In recent years, Chinese cities have faced persistent O3 pollution challenges. O3 concentrations at urban mountain sites, serving as proxies for urban background O3 levels, can help address data gaps in O3 research in China. This study, for the first time, analyzed O3 data from ten urban mountain sites during 2015–2022 using statistical methods like the Mann-Kendall test, Theil-Sen slope estimation, and Pearson correlation analysis to reveal characteristics and trends in urban background O3 and proposed a metric for assessing mountain sites as urban background stations. Results indicate that O3 at mountain sites were generally higher than at plain sites, regardless of mean, 10th percentile, or 90th percentile the average maximum daily 8-h average (MDA8) O3. Although mountain sites exhibited similar annual and diurnal variations as plain sites, their amplitudes were significantly lower. Significant upward trends (P < 0.05) in MDA8 O3 were observed mainly at plain sites, whereas trends at mountain sites were insignificant (P > 0.05) during 2015–2022. The increase in urban ground-level O3 was largely due to changes in VOCs and NOx emission structures, which reduce nighttime titration effects while enhancing daytime O3 production. The insignificant trends observed at mountain sites suggest that these mountain sites may be in NOx-limited or transitional regimes rather than VOCs-limited regimes, which is also associated with their lower NOx concentrations compared to plain sites. These findings suggest that if China continues to prioritize the reduction of NOx emissions, urban ground-level O3 could further increase and approach the O3 at mountain sites. Finally, this study proposes that the correlation in nighttime O3 concentrations between mountain and plain stations can serve as a valuable indicator for evaluating the suitability of mountain stations as regional background stations in urban areas. It recommends mountain sites in cities such as Changji, Nanping for urban background O3 monitoring stations.

Blood Pressure Control in Pregnant Patients with Chronic Hypertension and Diabetes: Should

BackgroundThe Chronic Hypertension and Pregnancy Study (CHAP) demonstrated that a target blood pressure of <140/90 mm Hg during pregnancy is associated with improved perinatal outcomes. Outside of pregnancy, pharmacologic therapy for patients with diabetes and hypertension is adjusted to a target blood pressure of <130/80 mm Hg. During pregnancy, patients with both diabetes and chronic hypertension may also benefit from tighter control with a target blood pressure (BP) <130/80 mm Hg. ObjectiveWe compared perinatal outcomes in patients with hypertension and diabetes who achieved BP <130/80 versus 130-139/80-89 mm Hg. Study DesignThis was a secondary analysis of a multi-center randomized controlled trial. Participants were included in this secondary analysis if they had diabetes diagnosed prior to pregnancy or at <20 weeks’ gestation and at least two recorded BP measurements prior to delivery. Average systolic and diastolic BP were calculated using ambulatory antenatal BPs. The primary composite outcome was preeclampsia with severe features, indicated preterm birth <35 weeks, or placental abruption. Secondary outcomes were components of the primary outcome, cesarean delivery, fetal or neonatal death, neonatal intensive care unit (NICU) admission, and small for gestational age (SGA). Comparisons were made between those with an average systolic BP <130 mm Hg and average diastolic BP <80 mm Hg and those with an average systolic blood pressure 130-139 mm Hg or diastolic blood pressure 80-89 mm Hg using Student’s t-test and chi-squared tests. Multivariable log-binomial regression models were used to evaluate risk ratios between blood pressure groups for dichotomous outcomes while accounting for baseline covariates. ResultsOf 434 participants included, 150 (34.6%) had an average blood pressure less than 130/80 mm Hg. Participants with an average blood pressure less than 130/80 were more likely to be on antihypertensive medications at the start of pregnancy and more likely to have newly diagnosed DM prior to 20 weeks. Participants with an average blood pressure less than 130/80 mm Hg were less likely to have the primary adverse perinatal outcome (19.3% vs 46.5%, adjusted relative risk (aRR) 0.43, 95% CI 0.30-0.61, p<0.01), with decreased risks specifically of preeclampsia with severe features (aRR 0.35, 95% CI 0.23-0.54) and indicated preterm birth prior to 35 weeks (aRR 0.44, 95% CI 0.24-0.79). The risk of NICU admission was lower in the lower blood pressure group (aRR 0.74, 95% CI 0.59-0.94). No differences were noted in cesarean delivery (aRR 1.04, 95% CI 0.90-1.20), fetal or neonatal death (aRR 0.59, 95% CI 0.12-2.92). SGA less than the 10th percentile was lower in the lower blood pressure group (aRR 0.37, 95% CI 0.14-0.96). ConclusionIn those with chronic hypertension and diabetes prior to 20 weeks, achieving an average goal blood pressure of <130/80 mm Hg may be associated with improved perinatal outcomes.

Does decreased fetal growth estimation in the appropriate for gestational age range affect delivery outcomes?

To study the effect of decreased estimated fetal weight (EFW) percentiles in appropriate for gestational age fetuses. This retrospective cohort study included women who had second and third trimester ultrasound examinations. Delivery and neonatal outcomes of pregnancies with decreased EFW of ≥ 30 percentiles in EFW between ultrasound examinations (decreased growth group) and those without such a decrease (control group) were compared. Deliveries with EFW or birthweight below the 10th percentile were excluded. Among 1610 deliveries, 57 were in the decreased growth group and 1553 in the control group. Maternal characteristics did not differ between the groups except for higher rate of nulliparity in the decreased growth group. We found similar rates of Category II/III monitoring, cesarean deliveries due to non-reassuring fetal heart rate and adverse neonatal outcomes. Neonatal birthweight was lower in the decreased growth group as compared to controls. This study did not find association between the group of appropriate for gestational age fetuses with decreased growth, with adverse outcomes.

Maternal morbidity in postpartum severe preeclampsia by obstetric delivery volume

BackgroundPre-eclampsia is a leading cause of maternal morbidity and mortality in the United States. Emerging data suggests that postpartum pre-eclampsia may be associated with a higher incidence of maternal morbidity compared to hypertensive disorders of pregnancy (HDP) diagnosed antenatally. Understanding postpartum maternal risk across facilities with a spectrum of obstetric services is critical with the rising rates of pre-eclampsia in all healthcare settings. ObjectiveWe investigated the relationship between facility delivery volume and rates of nontransfusion severe maternal morbidity (SMM) among patients readmitted postpartum for pre-eclampsia with severe features. Study DesignThis is a retrospective cohort study using the Nationwide Readmissions Database (2015–2019) of postpartum patients readmitted for pre-eclampsia with severe features. Our primary outcome was nontransfusion SMM during readmission, defined per U.S. Centers for Disease Control and Prevention criteria. We also evaluated SMM, cardiac SMM, and individual morbidities. The exposure variable was the number of annual deliveries at the readmitting facility. Restricted cubic splines with 4 knots were used to assess the functional form of the relationship between obstetric delivery volume and nontransfusion SMM; a linear relationship was identified as optimal. Logistic regression was used to estimate adjusted odds ratios (aOR) which controlled for maternal age, nontransfusion SMM at delivery, expanded obstetric comorbidity index, and HDP during delivery. ResultsThe cohort included 29,472 patients readmitted with postpartum pre-eclampsia with severe features. The primary payer was 55% private and 42% governmental. Median age was 31.4 years. Most patients did not have prior HDP (65%) or chronic hypertension (86%) diagnosis antenatally. The median interval from delivery hospitalization to readmission was 3.9 days (25th percentile–75th percentile: 2.2–6.5). Nontransfusion SMM occurred in 7% of patients readmitted to facilities with >2000 deliveries compared to 9% with 1 to 2000 deliveries, and 52% without any delivery hospitalizations. The most common SMM was pulmonary edema and heart failure, observed in 4% of readmissions. We observed that for every increase in 1000 deliveries, the odds of a nontransfusion SMM at readmission decreased by 3.5% (aOR: 0.965; 95% confidence interval: 0.94, 0.99). ConclusionNontransfusion SMM for postpartum readmissions with pre-eclampsia with severe features was inversely associated with readmitting hospital delivery volume. This information may guide risk-reducing initiatives for identifying strategies to optimize postpartum care at facilities with lower or no delivery volume.