Assessment of nebivolol efficacy in experimental models of toxoplasmosis: insights into parasite burden reduction and neuronal protection.

This study investigates the efficacy of nebivolol (NBV) in experimental models of toxoplasmosis, focusing on parasite burden reduction and neuronal protection. In the acute model of experimental toxoplasmosis, Swiss mice infected with RH strain tachyzoites received oral NBV chlorhydrate doses of 2 mg/kg/day and 4 mg/kg/day for 8 days. Treatment with NBV significantly reduced parasite burden compared to vehicle and standard drug (PYR) groups. In the chronic model of experimental toxoplasmosis, C57/BL6 mice infected with the ME49 strain received NBV chlorhydrate 41 days post-infection and were evaluated after 10 days of treatment. NBV chlorhydrate effectively reduced cyst number and area, as well as bradyzoite burden compared to controls. Histological analysis demonstrated that NBV chlorhydrate preserved neuronal count, with the 4 mg/kg/day dose yielding counts similar to non-infected mice. Statistical analysis confirmed significant differences compared to control groups. Furthermore, immunohistochemical analysis revealed a significant reduction in iNOS labeling in the brains of mice treated with NBV chlorhydrate, indicating a decrease in nitric oxide production compared to control groups. These findings suggest NBV's potential as a promising candidate for toxoplasmosis treatment, highlighting its ability to reduce parasite burden and protect neuronal integrity. Further research is warranted to elucidate NBV's mechanisms of action and its clinical application in managing toxoplasmosis.

Anti-Toxoplasma gondii screening of MMV pandemic response box and evaluation of RWJ-67657 efficacy in chronically infected mice.

Toxoplasmosis is a significant public health concern with limited therapeutic options. The medicines for malaria venture (MMV) developed the pandemic response box (PRB) containing 400 drug-like molecules with broad pathogen activity. The aim of this work is to evaluate PRB compounds for their anti-Toxoplasma gondii activity and identify promising candidates for further evaluation. Screening identified 42 selective compounds with half effective concentration (EC50) ranging from 2.4 to 913.1 nm and half cytotoxic concentration (CC50) ranging from 6 µm to >50 µm. Selectivity index (SI) values (CC50/EC50) ranged from 11 to 17 708. Based on its in silico and in vitro profile and its commercial availability, RWJ-67657 was selected for further studies. Molecular docking analysis showed RWJ-67657 is predicted to bind to T. gondii p38 mitogen-activated protein kinase (TgMAPK). Oral administration of RWJ-67657 (20 mg kg day−1/10 days) significantly reduced parasite burden in chronically infected mice compared to mock-treated group (P < 0.01). These findings highlight the PRB as a promising source for anti-T. gondii compounds, with several showing favourable drug properties, including MMV1634492, MMV002731, MMV1634491, MMV1581551, MMV011565, MMV1581558, MMV1578577, MMV233495 and MMV1580482, firstly described here as anti-T. gondii agents. RWJ-67657 emerges as a valuable drug candidate for experimental chronic cerebral toxoplasmosis therapy.

The association of prenatal phthalates, organophosphorous pesticides, and organophosphate esters with early child language ability in Norway.

BACKGROUND: Prenatal exposure to phthalates, organophosphate esters, and organophosphorous pesticides have been associated with neurodevelopmental deficits including language ability, however, few studies consider the effect of exposure mixtures and the potential longitudinal detriments over time. OBJECTIVE: This study examines the influence of prenatal exposure to phthalates, organophosphate esters, and organophosphorous pesticides, on children's language ability from toddlerhood to the preschool period. METHODS: This study includes 299 mother-child dyads from Norway in the Norwegian Mother, Father and Child Cohort Study (MoBa). Prenatal exposure to chemicals were assessed at 17 weeks' gestation, and child language skills were assessed at 18 months using the Ages and Stages Questionnaire communication subscale and at preschool age using the Child Development Inventory. We ran two structural equation models to examine the simultaneous influences of chemical exposures on parent-reported and teacher-reported child language ability. RESULTS: Prenatal organophosphorous pesticides were negatively associated with preschool language ability through language ability at 18 months. Additionally, there was a negative association between low molecular weight phthalates and teacher-reported preschool language ability. There was no effect of prenatal organophosphate esters on child language ability at either 18 months or preschool age. CONCLUSIONS: This study adds to the literature on prenatal exposure to chemicals and neurodevelopment and highlights the importance of developmental pathways in early childhood.

Design of orthogonal regulatory systems for modulating gene expression in plants.

Agricultural biotechnology strategies often require the precise regulation of multiple genes to effectively modify complex plant traits. However, most efforts are hindered by a lack of characterized tools that allow for reliable and targeted expression of transgenes. We have successfully engineered a library of synthetic transcriptional regulators that modulate expression strength in planta. By leveraging orthogonal regulatory systems from Saccharomyces spp., we have developed a strategy for the design of synthetic activators, synthetic repressors, and synthetic promoters and have validated their use in Nicotiana benthamiana and Arabidopsis thaliana. This characterization of contributing genetic elements that dictate gene expression represents a foundation for the rational design of refined synthetic regulators. Our findings demonstrate that these tools provide variation in transcriptional output while enabling the concerted expression of multiple genes in a tissue-specific and environmentally responsive manner, providing a basis for generating complex genetic circuits that process endogenous and environmental stimuli.

Prenatal organophosphorus pesticide exposure and executive function in preschool-aged children in the Norwegian Mother, Father and Child Cohort Study (MoBa).

INTRODUCTION: Prenatal exposure to organophosphorus pesticides (OPPs) has been associated with neurodevelopmental deficits in children, however evidence linking OPPs with specific cognitive mechanisms, such as executive function (EF), is limited. OBJECTIVE: This study aims to evaluate the association between prenatal exposure to OPPs with multiple measures of EF in preschool-aged children, while considering the role of variant alleles in OPP metabolism genes. METHODS: We included 262 children with preschool attention-deficit/hyperactivity disorder (ADHD), and 78 typically developing children, from the Preschool ADHD substudy of the Norwegian, Mother, Father, and Child Cohort Study. Participants who gave birth between 2004 and 2008 were invited to participate in an on-site clinical assessment when the child was approximately 3.5 years; measurements of EF included parent and teacher rating on Behavior Rating Inventory of Executive Function-Preschool (BRIEF-P), and three performance-based assessments. We measured OPP metabolites in maternal urines collected at ∼17 weeks' gestation to calculate total dimethyl- (ΣDMP) and diethyl phosphate (ΣDEP) metabolite concentrations. We estimated multivariable adjusted ß's and 95% confidence intervals (CIs) corresponding to a change in z-score per unit increase in log-ΣDMP/DEP. We further characterized gene-OPP interactions for maternal variants in PON1 (Q192R, M55L), CYP1A2 (1548T > C), CYP1A1 (IntG > A) and CYP2A6 (-47A > C). RESULTS: Prenatal OPP metabolite concentrations were associated with worse parent and teacher ratings of emotional control, inhibition, and working memory. A one log-∑DMP increase was associated with poorer teacher ratings of EF on the BRIEF-P (e.g. emotional control domain: ß = 0.55, 95% CI: 0.35, 0.74), when weighted to account for sampling procedures. We found less consistent associations with performance-based EF assessments. We found some evidence of modification for PON1 Q192R and CYP2A6 -47A > C. Association with other variants were inconsistent. CONCLUSIONS: Biomarkers of prenatal OPP exposure were associated with more adverse teacher and parent ratings of EF in preschool-aged children.

The role of child negative emotionality in parenting and child adjustment: Gene-environment interplay.

BACKGROUND: Evocative gene-environment correlation (rGE) describes a process through which children's heritable characteristics influence their rearing environments. The current study examined whether heritable influences on parenting and children's behavioural outcomes operate through child negative emotionality. METHOD: Using data from the Early Growth and Development Study, we examined associations among adoptive parent reports of child anger and sadness at 4.5 years, adoptive parents' hostile and warm parenting at 6 years and child behavioural problems and social competence at age 7. Birth parent temperament was included to test whether child effects on parents reflect evocative gene-environment correlation (rGE). RESULTS: Child anger at 4.5 years evoked hostile parenting from adoptive parents at 6 years, which was subsequently related to child problem behaviours at 7 years. Evocative rGE effects were identified for adoptive parents' hostile parenting. CONCLUSIONS: By employing a genetically informed design, we found that birth parent temperament was related to child negative emotionality. Adoptive parents were sensitive to child negative emotionality, and this sensitivity was linked to the child's later adjustment.

Psychopathology Symptoms are Associated with Prenatal Health Practices in Pregnant Women with Heavy Smoking Levels.

PURPOSE: Smoking during pregnancy may be linked to other problematic prenatal health behaviors in women. We examined interrelationships among prenatal smoking, prenatal health behaviors and mental health. The objective of this study was to examine factors that may contribute to variations in prenatal health practices among women who smoke during pregnancy. METHODS: Birth mothers from an adoption study (N = 912) were interviewed about prenatal smoking, health behaviors, and mental health symptoms at 5 months postpartum. RESULTS: One-quarter of participants (N = 222) reported smoking 6 or more cigarettes daily for at least 1 trimester. For mothers who smoked more than 6 cigarettes daily, higher levels of antisocial behaviors (ß = - .14, p = .03) and depressive symptoms (ß = - .17, p = .03) were associated with less frequent prenatal folate use; antisocial behaviors and depressive symptoms were not associated for prenatal folate use among women who did not smoke more than 6 cigarettes daily. For mothers who did not smoke more than 6 cigarettes daily, more depressive symptoms were associated with fewer prenatal care visits (ß = .12, p = .01). Antisocial behaviors and anxiety symptoms were not associated with prenatal care visits in either group of mothers. CONCLUSIONS FOR PRACTICE: Maternal antisocial behaviors and depressive symptoms during pregnancy may be markers for poorer adherence to recommendations for folate supplementation among women who smoke 6 or more cigarettes daily during pregnancy, independent of adequacy of prenatal care.

The intergenerational transmission of mathematics achievement in middle childhood: A prospective adoption design.

The present study uses a parent-offspring adoption design to examine the dual roles of heritable and environmental influences on children's mathematics achievement. Linked sets (N = 195) of adopted children, adoptive parents, and birth parents each completed a measure of mathematics fluency (i.e., simple computational operations). Birth parent mathematics achievement and adoptive father mathematics achievement positively correlated with child achievement scores at age 7, whereas adoptive mother and adopted child mathematics achievement scores were not significantly associated with one another. Additionally, findings demonstrated no significant effects of gene-environment interactions on child mathematics achievement at age 7. These results indicate that both heritable and rearing environmental factors contribute to children's mathematics achievement and identify unique influences of the paternal rearing environment on mathematics achievement in middle childhood.

Use of ablation and ultrasonic aspiration at primary debulking surgery in advanced stage ovarian, fallopian tube, and primary peritoneal cancer.

OBJECTIVES: Ovarian cancer patients with miliary disease have the lowest rates of complete surgical resection and poorest survival. Adjunct surgical techniques may potentially increase rates of complete surgical resection. No studies have evaluated the use of these techniques in primary debulking surgery for ovarian cancer patients with miliary disease. The aim of this study was to examine the use of adjunct surgical techniques during primary debulking surgery for patients with advanced epithelial ovarian, fallopian tube, and primary peritoneal cancer with miliary disease. METHODS: Medical records of patients with International Federation of Gynecology and Obstetrics (FIGO) stages IIIC-IVB epithelial ovarian, fallopian tube, or primary peritoneal cancer with miliary disease undergoing primary debulking surgery from January 2010 to December 2014 were reviewed. Adjunct surgical techniques were defined as ultrasonic surgical aspiration, argon enhanced electrocautery, thermal plasma energy, and traditional electrocautery ablation. Patients undergoing surgery with and without these devices were compared with respect to demographics, operative characteristics, postoperative complications, residual disease, progression free survival and overall survival. RESULTS: A total of 135 patients with miliary disease underwent primary debulking surgery, of which 30 (22.2%) patients used adjunct surgical techniques. The most common devices were ultrasonic surgical aspiration (40%) and argon enhanced electrocautery (36.7%). The most common sites of use were diaphragm (63.3%), pelvic peritoneum (30%), bowel mesentery (20%), and large bowel serosa (20%). There were no differences in age, stage, primary site, histology, operative time, surgical complexity, or postoperative complications for patients operated on with or without these devices. Volume of residual disease was similar (0.1-1 cm: 60% with adjunct techniques versus 68.6% without; complete surgical resection: 16.7% with adjunct techniques versus 13.3% without; p=0.67). For patients with ≤1 cm residual disease, median progression free survival (15 versus 15 months, p=0.65) and median overall survival (40 versus 55 months, p=0.38) were also similar. CONCLUSION: Adjunct surgical techniques may be incorporated during primary debulking surgery for patients with advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer with miliary disease; however, these do not improve the rate of optimal cytoreduction.

Did I Inherit My Moral Compass? Examining Socialization and Evocative Mechanisms for Virtuous Character Development.

Virtuous character development in children is correlated with parenting behavior, but the role of genetic influences in this association has not been examined. Using a longitudinal twin/sibling study (N = 720; Time 1 (T1) Mage = 12-14 years, Time 3 (T3) Mage = 25-27 years), the current report examines associations among parental negativity/positivity and offspring responsibility during adolescence, and subsequent young adult conscientiousness. Findings indicate that associations among parental negativity and offspring virtuous character during adolescence and young adulthood are due primarily to heritable influences. In contrast, the association between concurrent parental positivity and adolescent responsibility was due primarily to heritable and shared environmental influences. These findings underscore the contributions of heritable influences to the associations between parenting and virtuous character that have previously been assumed to be only environmentally influenced, emphasizing the complexity of mechanisms involved in the development of virtuous character.

Exploring the promise of assessing dynamic characteristics of the family for predicting adolescent risk outcomes.

BACKGROUND: Family-based assessments of risk factors for adolescent emotional, behavioral, and substance use problems can be used to identify adolescents who are at risk and intervene before problems cause clinically significant impairment. Expanding traditional methods for assessing risk, this study evaluates whether lability, referring to the degree to which parent-adolescent relationships and parenting fluctuate from day to day, might offer additional value to assessment protocols aimed at identifying precursor risk factors. METHODS: This study sampled 151 adolescents and caregivers, collecting data at a baseline assessment, a 21-day daily diary protocol, and a 12-month follow-up assessment. Daily diary data were used to calculate within-family lability scores in parenting practices, parent-adolescent connectedness, and parent-adolescent conflict. RESULTS: Regression analyses evaluated whether lability predicted adolescent's depression, anxiety, antisocial behavior (ASB), drunkenness, and marijuana use at 12-month follow-up. Lability in parent-adolescent connectedness, accounting for baseline levels, gender, age, and initial levels of outcomes, was associated with risk for depression, anxiety, ASB, drunkenness, and marijuana use. Lability in parenting practices also was associated with risk for depression, anxiety, and drunkenness. Baseline levels moderated some of these effects. Parent-adolescent conflict lability was only associated with depression. CONCLUSIONS: These findings provide evidence for substantial value added when including dynamic assessments of family lability in predicting long-term adolescent risk outcomes and call for integration of dynamic methods into assessment practices.

The Pennsylvania Longitudinal Study of Parents and Children (PALSPAC) Twin Registry.

The Pennsylvania Longitudinal Study of Parents and Children Twin Registry was developed to capture a representative sample of multiple births and their parents in the state of Pennsylvania. The registry has two main efforts. The first began in 2012 through recruitment of adolescents in Pennsylvania schools. The second effort began in January 2019 in partnership with the Pennsylvania Department of Health to capture the birth cohort of twins born from 2007 to 2017. Study recruitment, sample demographics, focus and measures are provided, as well as future directions.

Polymorphisms and expression of inflammasome genes are associated with the development and severity of rheumatoid arthritis in Brazilian patients.

OBJECTIVE: In the present study, we analyzed the possible association of inflammasome gene variants and expression to rheumatoid arthritis (RA)'s development and severity in the Brazilian population. MATERIALS AND METHODS: Thirteen single nucleotide polymorphisms within six inflammasome genes (NLRP1, NLRP3, NLRC4, AIM2, CARD8, CASP1) as well as IL1B and IL18 genes in two different Brazilian populations (from Northeast and Southeast Brazil) were analyzed. We also evaluated inflammasome gene expression profile in resting and LPS + ATP-treated monocytes from RA patients and healthy individuals. For genetic association study, 218 patients and 307 healthy controls were genotyped. For gene expression study, inflammasome genes mRNA levels of 12 patients and ten healthy individuals were assessed by qPCR. RESULTS: Our results showed that rs10754558 NLRP3 and rs2043211 CARD8 polymorphisms are associated with RA development (p value = 0.044, OR = 1.77, statistical power = 0.999) and severity measured by Health Assessment Questionnaire (HAQ) (p value = 0.03), respectively. Gene expression analyses showed that RA patients display activation of CASP1, IL1B and IL1R genes independently of LPS + ATP activation. In LPS + ATP-treated monocytes, NLRP3 and NLRC4 expressions were also significantly higher in patients compared with controls. CONCLUSIONS: The first reported results in Brazilian populations support the role of inflammasome in the development of RA.

Promoter Variant Alters Expression of the Autophagic BECN1 Gene: Implications for Clinical Manifestations of Machado-Joseph Disease.

Autophagy is especially important in disorders where accumulation of the mutant protein is a hallmark, such as the Machado-Joseph disease/spinocerebellar ataxia type 3 (MJD/SCA3). We analyzed the promoter of the BECN1 gene, whose overexpression has been reported to exert neuroprotective effects in MJD, with the aim of finding variants that could be associated with expression levels of beclin-1 and could be tested as modifiers of onset and disease severity. A fragment encompassing the BECN1 promoter was sequenced in 95 MJD subjects and 120 controls. The impact of the variation detected on transcription factors (TFs) binding affinity was evaluated in silico and inferences concerning levels of expression were confirmed by fluorescence-based quantitative real-time PCR in a subset of 28 MJD subjects and 26 controls. Four previously described (rs60221525, rs116943570, rs34882610, and rs34037822) and one novel (c.-933delG) variants were identified. In silico analysis performed for the most frequent variants-rs60221525 C allele and rs116943570 T allele-predicted an impact of the presence of these alleles on TF binding affinity. BECN1 expression levels were in agreement with the in silico predictions, showing a tendency for decreased levels in samples with the rs60221525 C allele and for increased levels in samples with the rs116943570 T allele. MJD patients carrying the rs60221525 C allele presented a tendency for earlier estimated age at onset. Moreover, patients with the rs60221525 C allele presented a more severe clinical picture, compared to patients without this allele. The analysis of a larger number of patients from different cohorts, currently unavailable, would be required to confirm these results.

Effect of prior silane application on the bond strength of a universal adhesive to a lithium disilicate ceramic.

STATEMENT OF PROBLEM: Universal adhesives combine silane and various monomers in a single bottle to make them more versatile. Their adhesive performance is unclear. PURPOSE: The purpose of this in vitro study was to assess the effects of an additional silane application before using a universal adhesive on the adhesion between a disilicate glass ceramic and a composite resin by using a microshear bond strength test (µSBS) and fracture analysis immediately and after thermocycling. MATERIAL AND METHODS: One hundred lithium disilicate glass ceramic disks were divided into 10 groups for bond strength testing according to the following 3 surface treatments: silane application (built-in universal adhesive or with additional application), adhesive (Adper Single Bond Plus [SB, 3M ESPE], Scotchbond Universal Adhesive [U, 3M ESPE], and mixed U with Dual Cure Activator [DCA, 3M ESPE]); or thermocycling (half of the specimens were thermocycled 10000 times). After surface treatment, 5 resin cylinders were bonded to each disk and submitted to a µSBS test. The failure mode was analyzed under a stereomicroscope and evaluated by scanning electron microscope and energy-dispersive x-ray spectroscopy. Data from the µSBS test were analyzed by 3-way ANOVA followed by the Tukey HSD post hoc test (α=.05). RESULTS: An additional silane application resulted in a higher µSBS result for all adhesive groups (P<.05). CONCLUSIONS: Ceramic surface treatment influenced the performance of adhesives, which may be improved with an additional silane application.

Novel candidate blood-based transcriptional biomarkers of Machado-Joseph disease.

BACKGROUND: Machado-Joseph disease (or spinocerebellar ataxia type 3) is a late-onset polyglutamine neurodegenerative disorder caused by a mutation in the ATXN3 gene, which encodes for the ubiquitously expressed protein ataxin-3. Previous studies on cell and animal models have suggested that mutated ataxin-3 is involved in transcriptional dysregulation. Starting with a whole-transcriptome profiling of peripheral blood samples from patients and controls, we aimed to confirm abnormal expression profiles in Machado-Joseph disease and to identify promising up-regulated genes as potential candidate biomarkers of disease status. METHODS: The Illumina Human V4-HT12 array was used to measure transcriptome-wide gene expression in peripheral blood samples from 12 patients and 12 controls. Technical validation and validation in an independent set of samples were performed by quantitative real-time polymerase chain reaction (PCR). RESULTS: Based on the results from the microarray, twenty six genes, found to be up-regulated in patients, were selected for technical validation by quantitative real-time PCR (validation rate of 81% for the up-regulation trend). Fourteen of these were further tested in an independent set of 42 patients and 35 controls; 10 genes maintained the up-regulation trend (FCGR3B, CSR2RA, CLC, TNFSF14, SLA, P2RY13, FPR2, SELPLG, YIPF6, and GPR96); FCGR3B, P2RY13, and SELPLG were significantly up-regulated in patients when compared with controls. CONCLUSIONS: Our findings support the hypothesis that mutated ataxin-3 is associated with transcription dysregulation, detectable in peripheral blood cells. Furthermore, this is the first report suggesting a pool of up-regulated genes in Machado-Joseph disease that may have the potential to be used for fine phenotyping of this disease. © 2015 International Parkinson and Movement Disorder Society.

Mitochondrial DNA and Y-chromosome structure at the Mediterranean and Atlantic façades of the Iberian Peninsula.

OBJECTIVES: The aim of this study is to analyze mitochondrial DNA and Y-chromosome lineages in a range of Atlantic and Mediterranean populations of the Iberian Peninsula in search of genetic differences between both façades and to uncover the most probable geographic origin and coalescence ages of lineages. METHODS: The control region of mitochondrial DNA and haplogroup diagnostic positions were analyzed in 575 subjects and Y-chromosome markers were typed in 260 unrelated males. Moreover, previously published data were compiled and used in the analyses. RESULTS: The level of genetic structure deduced from uniparental markers for the Iberian Peninsula was weak, with stronger Atlantic versus Mediterranean than North to South differentiation and larger diversities in the South. In general, mitochondrial DNA haplogroups had mainly Paleolithic and Mesolithic coalescences in Europe, although some of them, ruling out drift effects, seem to have younger implantation in Central Europe and the Atlantic areas than in the Mediterranean (I, J, J2a, T1, and W) while others as N1 and X could have reached the Iberian Peninsula at the Neolithic transition. On the other hand, younger coalescence ages are being proposed for the arriving or spread of the bulk of Y-chromosome lineages in Europe. CONCLUSIONS: The major haplotypic affinities found for all the Iberian Peninsula regions were always with North Africa and the Atlantic Islands. These results draw an Atlantic network that clearly resembles those of the Megalithic Copper and Bronze cultures at this part of Europe.

Comparative analysis electroencephalographic of alpha, Beta and gamma bands of a healthy individual and one with hemiparesis.

[Purpose] The study analyzed the electroencephalographic (EEG) data of the central cortical areas, during execution of the motor gestures of feeding, activation of the system of mirror neurons, and imagery between a right hemiparetic volunteer (RHV) and a healthy volunteer (HV). [Subjects and Methods] The volunteers' EEG data were recorded with their eyes open for 4 minutes while they performed five experimental tasks. [Results] The alpha band, absolute power value of HV was lower than that of RHV. In the beta band, during the practice condition, there was an increase in the magnitude of the absolute power value of HV at T3, possibly because T3 is representative of secondary motor areas that work with cortical neurons related to planning and organizing sequence of movements performed by the hands. The gamma band is related to the state of preparation for movement and memory. The results of this study indicate that there was increased activation of the gamma frequency band of HV. [Conclusion] The findings of this study have revealed the changes in pattern characteristics of each band which may be associated with the brain injury of the hemiparetic patient.

Maternal smoking during pregnancy is associated with DNA methylation in early adolescence: A sibling comparison design.

Maternal smoking during pregnancy (MSDP) may impact offspring biological (e.g., deoxyribonucleic acid methylation [DNAm]) and behavioral (e.g., attention-deficit/hyperactivity disorder hyperactive/impulsive [ADHD-HI] symptoms) development. There has been consistency in findings of differential methylation in global DNAm, and the specific genes AHRR, CYP1A1, CNTNAP2, MYO1G, and GFI1 in relation to MSDP. The current study aims to (a) replicate the associations of MSDP and DNAm in prior literature in middle childhood-adolescence (cross-sectionally) using a sibling-comparison design where siblings were discordant for MSDP (n = 328 families; Mage Sibling 1 = 13.02; Sibling 2 = 10.20), adjusting for prenatal and postnatal covariates in order to isolate the MSDP exposure on DNAm. We also (b) cross-sectionally explored the role of DNAm in the most robust MSDP-ADHD associations (i.e., with ADHD-HI) previously found in this sample. We quantified smoking exposure severity for each sibling reflecting time and quantity of MSDP, centered relative to the sibling pair's average (i.e., within-family centered, indicating child-specific effects attributable MSDP exposure) and controlling for the sibling average MSDP (i.e., between-family component, indicating familial confounding related to MSDP). We found that child-specific MSDP was associated with global DNAm, and CNTNAP2, CYP1A1, and MYO1G methylation after covariate adjustment, corroborating emerging evidence for a potentially causal pathway between MSDP and DNAm. There was some evidence that child-specific CNTNAP2 and MYO1G methylation partially explained associations between MSDP and ADHD-HI symptoms, though only on one measure (of two). Future studies focused on replication of these findings in a longitudinal genetic design could further solidify the associations found in the current study. (PsycInfo Database Record (c) 2024 APA, all rights reserved).