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1.
bioRxiv ; 2024 May 30.
Article in English | MEDLINE | ID: mdl-38853962

ABSTRACT

Lipoprotein kinetics are a crucial factor in understanding lipoprotein metabolism since a prolonged time in circulation can contribute to the atherogenic character of apolipoprotein-B (ApoB)-containing lipoproteins (B-lps). Here, we report a method to directly measure lipoprotein kinetics in live developing animals. We developed a zebrafish geneticly encoded reporter, LipoTimer, in which endogenous ApoBb.1 is fused to the photoconvertible fluorophore Dendra2 which shift its emission profile from green to red upon UV exposure. By quantifying the red population of ApoB-Dendra2 over time, we found that B-lp turnover in wild-type larvae becomes faster as development proceeds. Mutants with impaired B-lp uptake or lipolysis present with increased B-lp levels and half-life. In contrast, mutants with impaired B-lp triglyceride loading display slightly fewer and smaller-B-lps, which have a significantly shorter B-lp half-life. Further, we showed that chronic high-cholesterol feeding is associated with a longer B-lp half-life in wild-type juveniles but does not lead to changes in B-lp half-life in lipolysis deficient apoC2 mutants. These data support the hypothesis that B-lp lipolysis is suppressed by the flood of intestinal-derived B-lps that follow a high-fat meal.

2.
Forensic Sci Res ; 9(2): owae005, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38846987

ABSTRACT

Parasites are ubiquitous, diverse, and have close interactions with humans and other animals. Despite this, they have not garnered significant interest from forensic scientists, and their utility as indicators in criminal investigations has been largely overlooked. To foster the development of forensic parasitology we explore the utility of parasites as forensic indicators in five broad areas: (i) wildlife trafficking and exploitation, (ii) biological attacks, (iii) sex crimes, (iv) criminal neglect of humans and other animals, and (v) indicators of movement and travel. To encourage the development and growth of forensic parasitology as a field, we lay out a four-step roadmap to increase the use and utility of parasites in criminal investigations.

3.
Curr Opin Toxicol ; 382024 Jun.
Article in English | MEDLINE | ID: mdl-38846809

ABSTRACT

The utilization of transcriptomic studies identifying profiles of gene expression, especially in toxicogenomics, has catapulted next-generation sequencing to the forefront of reproductive toxicology. An innovative yet underutilized RNA sequencing technique emerging into this field is single-cell RNA sequencing (scRNA-seq), which provides sequencing at the individual cellular level of gonad tissue. ScRNA-seq provides a novel and unique perspective for identifying distinct cellular profiles, including identification of rare cell subtypes. The specificity of scRNA-seq is a powerful tool for reproductive toxicity research, especially for translational animal models including zebrafish. Studies to date not only have focused on 'tissue atlassing' or characterizing what cell types make up different tissues but have also begun to include toxicant exposure as a factor that this review aims to explore. Future scRNA-seq studies will contribute to understanding exposure-induced outcomes; however, the trade-offs with traditional methods need to be considered.

4.
Acta Trop ; 256: 107248, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38734359

ABSTRACT

Bats and ticks are important sources of zoonotic pathogens. Therefore, understanding the diversity, distribution, and ecology of both groups is crucial for public health preparedness. Soft ticks (Argasidae) are a major group of ectoparasites commonly associated with bats. The multi-host life cycle of many argasids make them important vectors of pathogens. Over nine years (2011-2020), surveillance was undertaken to identify the ticks associated with common bats in Singapore. During this period, the bat tick Ornithodoros batuensis was detected within populations of two cave roosting bat species: Eonycteris spelaea and Penthetor lucasi. We examined the relationship between bat species, roosting behaviour, and probability of O. batuensis infestation. We also estimated the relationship between bat life history variables (body condition index, sex, and age) on the probability of infestation and tick count. This represents the first detection of O. batuensis and the genus Ornithodoros within Singapore. We also provide evidence of the continued persistence of Argas pusillus in Singapore with the second local record.

6.
Brain Behav Immun ; 119: 807-817, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38710339

ABSTRACT

Understanding the psychiatric symptoms of Alzheimer s disease (AD) is crucial for advancing precision medicine and therapeutic strategies. The relationship between AD behavioral symptoms and asymmetry in spatial tau PET patterns is not well-known. Braak tau progression implicates the temporal lobes early. However, the clinical and pathological implications of temporal tau laterality remain unexplored. This cross-sectional study investigated the correlation between temporal tau PET asymmetry and behavior assessed using the neuropsychiatric inventory and composite scores for memory, executive function, and language, using data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset. In the entire cohort, continuous right and left temporal tau contributions to behavior and cognition were evaluated, controlling for age, sex, education, and tau burden on the contralateral side. Additionally, a temporal tau laterality index was calculated to define "asymmetry-extreme" groups (individuals with laterality indices greater than two standard deviations from the mean). 695 individuals (age = 73.9 ± 7.6 years, 372 (53.5 %) females) were included, comprising 281 (40%) cognitively unimpaired (CU) amyloid negative, 185 (27%) CU amyloid positive, and 229 (33%) impaired (CI) amyloid positive participants. In the full cohort analysis, right temporal tau was associated with worse behavior (B = 8.14, p-value = 0.007), and left temporal tau was associated with worse language (B = 1.4, p-value < 0.001). Categorization into asymmetry-extreme groups revealed 20 right- and 27 left-asymmetric participants. Within these extreme groups, there was additional heterogeneity along the anterior-posterior dimension. Asymmetrical tau burden is associated with distinct behavioral and cognitive profiles. Wide multi-cultural implementation of social cognition measures is needed to understand right-sided asymmetry in AD.


Subject(s)
Alzheimer Disease , Language , Positron-Emission Tomography , Temporal Lobe , tau Proteins , Humans , Alzheimer Disease/metabolism , Alzheimer Disease/diagnostic imaging , Female , Male , Aged , tau Proteins/metabolism , Cross-Sectional Studies , Temporal Lobe/metabolism , Temporal Lobe/diagnostic imaging , Aged, 80 and over , Positron-Emission Tomography/methods , Neuropsychological Tests , Functional Laterality/physiology , Cognition/physiology , Executive Function/physiology , Memory/physiology
7.
Toxics ; 12(5)2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38787106

ABSTRACT

Bottlenose dolphins (Tursiops spp.) inhabit bays, sounds, and estuaries (BSEs) throughout the southeast region of the U.S.A. and are sentinel species for human and ecosystem-level health. Dolphins are vulnerable to the bioaccumulation of contaminants through the coastal food chain because they are high-level predators. Currently, there is limited information on the spatial dynamics of mercury accumulation in these dolphins. Total mercury (THg) was measured in dolphin skin from multiple populations across the U.S. Southeast Atlantic and Gulf of Mexico coasts, and the influence of geographic origin, sex, and age class was investigated. Mercury varied significantly among sampling sites and was greatest in dolphins in St. Joseph Bay, Florida Everglades, and Choctawhatchee Bay (14,193 ng/g ± 2196 ng/g, 10,916 ng/g ± 1532 ng/g, and 7333 ng/g ± 1405 ng/g wet mass (wm), respectively) and lowest in dolphins in Charleston and Skidaway River Estuary (509 ng/g ± 32.1 ng/g and 530 ng/g ± 58.4 ng/g wm, respectively). Spatial mercury patterns were consistent regardless of sex or age class. Bottlenose dolphin mercury exposure can effectively represent regional trends and reflect large-scale atmospheric mercury input and local biogeochemical processes. As a sentinel species, the bottlenose dolphin data presented here can direct future studies to evaluate mercury exposure to human residents in St. Joseph Bay, Choctawhatchee Bay, and Florida Coastal Everglades, as well as additional sites with similar geographical, oceanographic, or anthropogenic parameters. These data may also inform state and federal authorities that establish fish consumption advisories to determine if residents in these locales are at heightened risk for mercury toxicity.

8.
Int J Exerc Sci ; 17(1): 274-284, 2024.
Article in English | MEDLINE | ID: mdl-38665168

ABSTRACT

Myofascial release is a popular therapy technique used to manipulate connective muscle tissue to become more pliable. The maintenance of body posture relies on mechanoreceptors located in connective tissue, thus manipulation of connective tissue should affect postural control. The effects of this phenomenon have not been well studied, leaving room for this investigation. PURPOSE: To observe if postural sway scores changed before and after foam rolling proximal (quadriceps and hamstrings) in comparison to distal (calves) muscles. METHODS: Thirty-six, college-aged female athletes (age 20.39 ± 0.25 years, mass 68.70 ± 1.97 kg, height 170.18 ± 1.56 cm.) performed approximately two and one-half minutes of moderate intensity foam rolling to their calves (n = 19, Group A) or to their hamstrings and quadricep muscle (n = 17, Group B). Center of Pressure (CoP) and Limit of Stability (LoS) testing was assessed both pre- and post-foam rolling using a computerized posturography balance plate. CoP sway was measured under both eyes open (EO) and eye closed (EC) Conditions on both stable and unstable surfaces. LoS was measured in the Anterior, Posterior, Left, and Right Directions. Effects of foam rolling on CoP and LoS were assessed using a repeated-measures MANOVA (α = 0.05). RESULTS: Eyes Open Stable Surface had the lowest postural sway (p = 0.001). However, CoP did not differ for any condition either between Groups (p ≥ 0.6) or from pre- to post-foam rolling (p = 0.3). LoS significantly differed between Directions such that LoS was greater in the frontal plane than in the sagittal plane (p = 0.011). There was also a significant Time X Group X Direction interaction effect (p = 0.001) such that LoS for Group A decreased after foam rolling (mean change = -1.621 cm) but increased for Group B after foam rolling (mean change = + 0.878 cm). No differences were found for any other Direction (p ≥ 0.1). CONCLUSION: This study demonstrated CoP and LoS improvements between the two groups based on acute effects of foam rolling intervention. Further research is suggested to determine if long-term gains are observed within or between groups.

9.
Trauma Case Rep ; 51: 101007, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38590923

ABSTRACT

An 18-year-old female presented to the emergency department after a motor vehicle collision. Initial imaging revealed a liver laceration. Subsequent labs showed significantly elevated prothrombin time, international normalized ratio, and activated partial thromboplastin time. Thromboelastography demonstrated a flatline tracing. The patient denied use of anticoagulation but admitted to synthetic cannabinoid use. It was believed the patient had taken synthetic cannabinoid contaminated by brodifacoum. She was therefore given prothrombin complex concentrate and vitamin K with blood products. The patient underwent sequential embolization, laparotomy, thoracotomy, and repair of the vena cava with a shunt. Thirty minutes postoperatively, her coagulation tests and thromboelastography were much improved. Two and a half hours postoperatively, it was determined she had sustained non-survivable injuries. The patient experienced brain death due to prolonged hypotension as a result of hemorrhagic shock with bleeding exacerbated by brodifacoum. To our knowledge, this is the first case reported of a trauma-induced coagulopathy exacerbated by brodifacoum-contaminated synthetic cannabinoid. Her coagulopathy was clearly not due to trauma alone and contributed greatly to the difficulty in controlling hemorrhage. The synthetic cannabinoid-associated coagulopathy rendered her otherwise potentially survivable injuries fatal. Given the frequency of multiple trauma and the recent increase in the prevalence of synthetic cannabinoid, it can be expected that the incidence of trauma complicated by synthetic cannabinoid-associated coagulopathy will increase in the near future. For patients that present with prolonged prothrombin time and/or activated partial thromboplastin time, it is important to inquire about recent synthetic cannabinoid use.

10.
ACS Biomater Sci Eng ; 10(5): 3280-3292, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38608136

ABSTRACT

Hydrogels have gained significant popularity as model platforms to study reciprocal interactions between cells and their microenvironment. While hydrogel tools to probe many characteristics of the extracellular space have been developed, fabrication approaches remain challenging and time-consuming, limiting multiplexing or widespread adoption. Thus, we have developed a modular fabrication approach to generate distinct hydrogel microenvironments within the same 96-well plate for increased throughput of fabrication as well as integration with existing high-throughput assay technologies. This approach enables in situ hydrogel mechanical characterization and is used to generate both elastic and viscoelastic hydrogels across a range of stiffnesses. Additionally, this fabrication method enabled a 3-fold reduction in polymer and up to an 8-fold reduction in fabrication time required per hydrogel replicate. The feasibility of this platform for two-dimensional (2D) cell culture applications was demonstrated by measuring both population-level and single-cell-level metrics via microplate reader and high-content imaging. Finally, a 96-well hydrogel array was utilized for three-dimensional (3D) cell culture, demonstrating the ability to support high cell viability. Together, this work demonstrates a versatile and easily adaptable fabrication approach that can support the ever-expanding tool kit of hydrogel technologies for cell culture applications.


Subject(s)
Hydrogels , Hydrogels/chemistry , Humans , Cell Culture Techniques/methods , Cell Culture Techniques/instrumentation , Cell Survival , Cell Culture Techniques, Three Dimensional/methods , Cell Culture Techniques, Three Dimensional/instrumentation , Elasticity , Viscosity
11.
Pediatr Pulmonol ; 59(6): 1747-1756, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38558514

ABSTRACT

OBJECTIVES: In adults, an isolated low FEV1 pattern (an FEV1 below the lower limit of normal with a preserved FVC and FEV1/FVC) has been associated with the risk of developing airway obstruction. Our objective was to examine the prevalence, stability, and clinical significance of an isolated low FEV1 pattern in the pediatric population. METHODS: We conducted a retrospective study of spirometries from children ages 6-21 years and categorized tests into spirometry patterns according to published guidelines and recent literature. In a subgroup of tests with an isolated low FEV1 pattern, we evaluated spirometry technique. We also examined the association of having a test with an isolated low FEV1 pattern with clinical markers of disease severity in a subgroup of children with cystic fibrosis (CF). RESULTS: The isolated low FEV1 pattern was uncommon across the 29,979 tests included (n = 645 [2%]). In the 263 children with an isolated low FEV1 pattern who had a follow-up test performed, the most frequent spirometry pattern at last test was normal (n = 123 [47%]). A primary diagnosis of CF was associated with increased odds of having at least one test with an isolated low FEV1 pattern (OR = 8.37, 95% CI = 4.70-15.96, p < .001). The spirometry quality in a subgroup of tests with an isolated low FEV1 pattern (n = 50) was satisfactory. In the subgroup of children with CF (n = 102), those who had a test with an isolated low FEV1 pattern had higher odds of using oral antibiotics in the last 12 months than those who had a normal pattern (OR = 3.50, 95% CI = 1.15-10.63, p = .03). CONCLUSIONS: The isolated low FEV1 pattern can occur repeatedly over time, usually transitions to a normal pattern, is not due to a poor spirometry technique, and could be clinically relevant in children with chronic lung diseases.


Subject(s)
Cystic Fibrosis , Spirometry , Humans , Child , Adolescent , Retrospective Studies , Female , Male , Forced Expiratory Volume , Prevalence , Cystic Fibrosis/physiopathology , Young Adult , Vital Capacity , Airway Obstruction/physiopathology , Airway Obstruction/diagnosis , Airway Obstruction/epidemiology , Clinical Relevance
12.
Neurobiol Dis ; 196: 106511, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38670277

ABSTRACT

Emerging evidence indicates that high-fat, high carbohydrate diet (HFHC) impacts central pathological features of Alzheimer's disease (AD) across both human incidences and animal models. However, the mechanisms underlying this association are poorly understood. Here, we identify compartment-specific metabolic and inflammatory dysregulations that are induced by HFHC diet in the 5xFAD mouse model of AD pathology. We observe that both male and female 5xFAD mice display exacerbated adiposity, cholesterolemia, and dysregulated insulin signaling. Independent of biological sex, HFHC diet also resulted in altered inflammatory cytokine profiles across the gastrointestinal, circulating, and central nervous systems (CNS) compartments demonstrating region-specific impacts of metabolic inflammation. Interestingly, inhibiting the inflammatory cytokine, soluble tumor necrosis factor (TNF) with the brain-permeant soluble TNF inhibitor XPro1595 was able to restore aspects of HFHC-induced metabolic inflammation, but only in male mice. Targeted transcriptomics of CNS regions revealed that inhibition of soluble TNF was sufficient to alter expression of hippocampal and cortical genes associated with beneficial immune and metabolic responses. Collectively, these results suggest that HFHC diet impairs metabolic and inflammatory pathways in an AD-relevant genotype and that soluble TNF has sex-dependent roles in modulating these pathways across anatomical compartments. Modulation of energy homeostasis and inflammation may provide new therapeutic avenues for AD.


Subject(s)
Alzheimer Disease , Diet, High-Fat , Disease Models, Animal , Mice, Transgenic , Tumor Necrosis Factor-alpha , Animals , Alzheimer Disease/metabolism , Alzheimer Disease/immunology , Alzheimer Disease/pathology , Alzheimer Disease/genetics , Mice , Male , Female , Tumor Necrosis Factor-alpha/metabolism , Diet, High-Fat/adverse effects , Signal Transduction/physiology , Sex Characteristics , Inflammation/metabolism
13.
Science ; 383(6690): 1499-1504, 2024 Mar 29.
Article in English | MEDLINE | ID: mdl-38547284

ABSTRACT

Methane emissions from solid waste may represent a substantial fraction of the global anthropogenic budget, but few comprehensive studies exist to assess inventory assumptions. We quantified emissions at hundreds of large landfills across 18 states in the United States between 2016 and 2022 using airborne imaging spectrometers. Spanning 20% of open United States landfills, this represents the most systematic measurement-based study of methane point sources of the waste sector. We detected significant point source emissions at a majority (52%) of these sites, many with emissions persisting over multiple revisits (weeks to years). We compared these against independent contemporaneous in situ airborne observations at 15 landfills and established good agreement. Our findings indicate a need for long-term, synoptic-scale monitoring of landfill emissions in the context of climate change mitigation policy.

14.
Children (Basel) ; 11(3)2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38539397

ABSTRACT

While schools provide one opportunity to encourage physical activity, caregivers play an exceedingly important role in creating an environment conducive to preschool children's physical activity. Yet, little is known regarding the perceptions of caregivers, important choice agents for young children's physical activity behavior after participating in a motor skill program. The purpose of this study was to examine caregivers' perceptions of facilitators and barriers to children's physical activity at home among rural, low-income families who participated in a school-based early childhood physical activity program, SKIPping with PALS, designed to increase physical activity and improve motor development. Eleven caregivers consented to participate in a semi-structured interview regarding their perceptions of physical activity and their experience after six months of participation in the program. An inductive, naturalistic evaluation approach was utilized for qualitative data analysis, following the six recursive phases of thematic analysis. A review of the interview transcripts revealed that all caregivers valued physical activity and encouraged their children to be active. Four major facilitators, four major barriers, and an overarching theme of parental support for childhood physical activity were identified. These factors are largely circumstantial and attitudinal and, thus, are difficult to modify but are important to be cognizant of when designing interventions.

15.
bioRxiv ; 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38464096

ABSTRACT

Emerging evidence indicates that high-fat, high carbohydrate diet (HFHC) impacts central pathological features of Alzheimer's disease (AD) across both human incidences and animal models. However, the mechanisms underlying this association are poorly understood. Here, we identify compartment-specific metabolic and inflammatory dysregulations that are induced by HFHC diet in the 5xFAD mouse model of AD pathology. We observe that both male and female 5xFAD mice display exacerbated adiposity, cholesterolemia, and dysregulated insulin signaling. Independent of biological sex, HFHC diet also resulted in altered inflammatory cytokine profiles across the gastrointestinal, circulating, and central nervous systems (CNS) compartments demonstrating region-specific impacts of metabolic inflammation. In male mice, we note that HFHC triggered increases in amyloid beta, an observation not seen in female mice. Interestingly, inhibiting the inflammatory cytokine, soluble tumor necrosis factor (TNF) with the brain-permeant soluble TNF inhibitor XPro1595 was able to restore aspects of HFHC-induced metabolic inflammation, but only in male mice. Targeted transcriptomics of CNS regions revealed that inhibition of soluble TNF was sufficient to alter expression of hippocampal and cortical genes associated with beneficial immune and metabolic responses. Collectively, these results suggest that HFHC diet impairs metabolic and inflammatory pathways in an AD-relevant genotype and that soluble TNF has sex-dependent roles in modulating these pathways across anatomical compartments. Modulation of energy homeostasis and inflammation may provide new therapeutic avenues for AD.

16.
Pharmaceutics ; 16(2)2024 Jan 30.
Article in English | MEDLINE | ID: mdl-38399255

ABSTRACT

Long-acting injectable cabotegravir is more effective than daily oral PrEP at preventing HIV transmission due to improved adherence, but requires bi-monthly large-volume intramuscular injections. Subcutaneous (SC) contraceptive implants can be formulated with antiretrovirals for extended-duration HIV PrEP. Islatravir (ISL) is a first-in-class, investigational antiretroviral with pharmacologic properties well-suited for implant delivery. We performed preclinical studies for the development of a reservoir-style, poly(ε-caprolactone) ISL-eluting implant by conducting a single-dose SC ISL dose-ranging pharmacokinetic (PK) study of 0.1, 0.3, and 1 mg/kg in adult Wistar rats. Non-compartmental analysis was conducted, and dose proportionality assessed for ISL plasma and intracellular islatravir-triphosphate (ISL-tp). Population PK models estimated ISL's unit impulse response to deconvolve ISL-implant in vivo absorption rate (mg/day) and cumulative mass (mg) from published rat plasma PK (n = 10). Drug release was interpreted using four kinetic models. Dose proportionality was affirmed for ISL and ISL-tp. A first-order, two-compartment model fitted the SC ISL bolus data. Mean (SD) absorption rate from 0 to 154 days was 0.072 ± 0.024 mg/day, and cumulative mass at 154 days was 8.67 ± 3.22 mg. ISL absorption was well-described by zero-order (r2 = 0.95) and Ritger-Peppas (r2 = 0.98). Our zero-order ISL-release poly(ε-caprolactone) implant is projected to achieve clinical PK above ISL-tp's PrEP efficacy threshold. Continued development for HIV PrEP applications is warranted.

17.
J Affect Disord ; 351: 499-506, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38309481

ABSTRACT

Anxiety and fear are key characteristics of eating disorders (EDs). Exposure therapy is a specific type of intervention aimed at reducing fear and anxiety and is efficacious in treating a variety of anxiety and related disorders. A growing body of research suggests that exposure therapy is also efficacious for the treatment of EDs. However, there is currently little research investigating mechanisms of change during exposure therapy for EDs. The current study (N = 143) expanded on an open series trial of imaginal exposure for EDs that found significant reductions in ED symptoms and core ED fears. In the current study we investigated change in state drive for thinness, body dissatisfaction, and anxiety as mechanisms underpinning change in ED symptoms and core ED fears during four sessions of online imaginal exposure treatment for EDs. We found that state body dissatisfaction, but not state drive for thinness or anxiety, was a mechanism of change for ED symptoms and some core ED fears. Our findings suggest that body dissatisfaction may be a mechanism driving change during exposure therapy for EDs. Optimizing exposure treatments to focus on body dissatisfaction may improve treatment outcomes for EDs.


Subject(s)
Feeding and Eating Disorders , Thinness , Humans , Feeding and Eating Disorders/therapy , Fear , Anxiety/therapy , Anxiety Disorders/therapy
18.
Oncogene ; 43(11): 763-775, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38310162

ABSTRACT

Both breast cancer and obesity can regulate epigenetic changes or be regulated by epigenetic changes. Due to the well-established link between obesity and an increased risk of developing breast cancer, understanding how obesity-mediated epigenetic changes affect breast cancer pathogenesis is critical. Researchers have described how obesity and breast cancer modulate the epigenome individually and synergistically. In this review, the epigenetic alterations that occur in obesity, including DNA methylation, histone, and chromatin modification, accelerated epigenetic age, carcinogenesis, metastasis, and tumor microenvironment modulation, are discussed. Delineating the relationship between obesity and epigenetic regulation is vital to furthering our understanding of breast cancer pathogenesis.


Subject(s)
Breast Neoplasms , Epigenesis, Genetic , Humans , Female , Breast Neoplasms/genetics , Breast Neoplasms/pathology , DNA Methylation , Histones/metabolism , Obesity/complications , Obesity/genetics , Tumor Microenvironment/genetics
19.
Horm Behav ; 161: 105506, 2024 May.
Article in English | MEDLINE | ID: mdl-38387104

ABSTRACT

Estradiol and progesterone potentiate and attenuate reward processes, respectively. Despite these well-characterized effects, there is minimal research on the effects of synthetic estrogens (e.g., ethinyl estradiol, or EE) and progestins (e.g., levonorgestrel, or LEVO) contained in clinically-utilized hormonal contraceptives. The present study characterized the separate effects of repeated exposure to EE or LEVO on responding maintained by a reinforcing visual stimulus. Forty ovary-intact female Sprague-Dawley rats received either sesame oil vehicle (n = 16), 0.18 µg/day EE (n = 16), or 0.6 µg/day LEVO (n = 8) subcutaneous injections 30-min before daily one-hour sessions. Rats' responding was maintained by a 30-sec visual stimulus on a Variable Ratio-3 schedule of reinforcement. The day after rats' last session, we determined rats estrous cycle phase via vaginal cytology before sacrifice and subsequently weighing each rat's uterus to further verify the contraceptive hormone manipulation. The visual stimulus functioned as a reinforcer, but neither EE nor LEVO enhanced visual stimulus maintained responding. Estrous cytology was consistent with normal cycling in vehicle rats and halting of normal cycling in EE and LEVO rats. EE increased uterine weights consistent with typical uterotrophic effects observed with estrogens, further confirming the physiological impacts of our EE and LEVO doses. In conclusion, a physiologically effective dose of neither EE nor LEVO did not alter the reinforcing efficacy of a visual stimulus reinforcer. Future research should characterize the effects of hormonal contraceptives on responding maintained by other reinforcer types to determine the generality of the present findings.


Subject(s)
Ethinyl Estradiol , Levonorgestrel , Rats, Sprague-Dawley , Animals , Female , Ethinyl Estradiol/pharmacology , Ethinyl Estradiol/administration & dosage , Levonorgestrel/pharmacology , Levonorgestrel/administration & dosage , Rats , Reinforcement, Psychology , Photic Stimulation/methods , Ovary/drug effects , Estrous Cycle/drug effects
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