Clinically, developmental exposure to the endocrine disrupting chemical, diethylstilboestrol (DES), results in long-term male and female infertility. Experimentally, developmental exposure to DES ...results in abnormal reproductive tract phenotypes in male and female mice. Previously, we reported that neonatal DES exposure causes ERα-mediated aberrations in the transcriptome and in DNA methylation in seminal vesicles (SVs) of adult mice. However, only a subset of DES-altered genes could be explained by changes in DNA methylation. We hypothesized that alterations in histone modification may also contribute to the altered transcriptome during SV development. To test this idea, we performed a series of genome-wide analyses of mouse SVs at pubertal and adult developmental stages in control and DES-exposed wild-type and ERα knockout mice. Neonatal DES exposure altered ERα-mediated mRNA and lncRNA expression in adult SV, including genes encoding chromatin-modifying proteins that can impact histone H3K27ac modification. H3K27ac patterns, particularly at enhancers, and DNA methylation were reprogrammed over time during normal SV development and after DES exposure. Some of these reprogramming changes were ERα-dependent, but others were ERα-independent. A substantial number of DES-altered genes had differential H3K27ac peaks at nearby enhancers. Comparison of gene expression changes, H3K27ac marks and DNA methylation marks between adult SV and adult uterine tissue from ovariectomized mice neonatally exposed to DES revealed that most of the epigenetic changes and altered genes were distinct in the two tissues. These findings indicate that the effects of developmental DES exposure cause reprogramming of reproductive tract tissue differentiation through multiple epigenetic mechanisms.
Abstract
Estrogen insensitivity syndrome (EIS) arises from rare mutations in estrogen receptor-α (ERα, encoded by ESR1 gene) resulting in the inability of estrogen to exert its biological effects. ...Due to its rarity, mutations in ESR1 gene and the underlying molecular mechanisms of EIS have not been thoroughly studied. Here, we investigate known ESR1 mutants, Q375H and R394H, associated with EIS patients using in vitro and in vivo systems. Comparison of the transcriptome and deoxyribonucleic acid methylome from stable cell lines of both Q375H and R394H clinical mutants shows a differential profile compared with wild-type ERα, resulting in loss of estrogen responsiveness. Molecular dynamic simulation shows that both ESR1 mutations change the ERα conformation of the ligand-receptor complexes. Furthermore, we generated a mouse model Esr1-Q harboring the human mutation using CRISPR/Cas9 genome editing. Female and male Esr1-Q mice are infertile and have similar phenotypes to αERKO mice. Overall phenotypes of the Esr1-Q mice correspond to those observed in the patient with Q375H. Finally, we explore the effects of a synthetic progestogen and a gonadotropin-releasing hormone inhibitor in the Esr1-Q mice for potentially reversing the impaired female reproductive tract function. These findings provide an important basis for understanding the molecular mechanistic consequences associated with EIS.
A homozygous missense mutation in the gene encoding the estrogen receptor α (ERα) was previously identified in a female patient with estrogen insensitivity syndrome. We investigated the molecular ...features underlying the impaired transcriptional response of this mutant (ERα-Q375H) and four other missense mutations at this position designed to query alternative mechanisms. The identity of residue 375 greatly affected the sensitivity of the receptor to agonists without changing the ligand binding affinity. Instead, the mutations caused changes in the affinity of coactivator binding and alterations in the balance of coactivator and corepressor recruitment. Comparisons among the transcriptional regulatory responses of these six ERα genotypes to a set of ER agonists showed that both steric and electrostatic factors contributed to the functional deficits in gene regulatory activity of the mutant ERα proteins. ERα-coregulator peptide binding in vitro and RIME (rapid immunoprecipitation mass spectrometry of endogenous) analysis in cells showed that the degree of functional impairment paralleled changes in receptor-coregulator binding interactions. These findings uncover coupling between ligand binding and coregulator recruitment that affects the potency rather than the efficacy of the receptor response without substantially altering ligand binding affinity. This highlights a molecular mechanism for estrogen insensitivity syndrome involving mutations that perturb a bidirectional allosteric coupling between ligand binding and coregulator binding that determines receptor transcriptional output.
The important value of the X-ray topography (XRT) technique for the investigation of III–V strained-layer relaxation processes is described. In addition to post-growth ex-situ XRT studies, a unique ...combined XRT/MBE growth facility has been constructed which allows the generation, motion and interaction of misfit dislocations to be monitored in-situ during epilayer growth, for the first time. The in-situ data already obtained for (100) InGaAs strained-layer growth on both Czochralski- and vertical-gradient freeze-grown GaAs substrates indicates technologically important differences in the initial relaxation process, including, in the latter case, the observation of a previously unreported secondary relaxation phase. Initial results relating to the influence of both post-growth annealing and the subsequent cool-down process are also described.
Abstract
Background
The Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P) Epidemiology, Surveillance and Preparedness of the Novel SARS-CoV-2 Epidemic (RESPONSE) ...seroprevalence study conducted monthly cross-sectional testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in blood donors in 6 US metropolitan regions to estimate the extent of SARS-CoV-2 infections over time.
Methods
During March–August 2020, approximately ≥1000 serum specimens were collected monthly from each region and tested for SARS-CoV-2 antibodies using a well-validated algorithm. Regional seroprevalence estimates were weighted based on demographic differences compared with the general population. Seroprevalence was compared with reported coronavirus disease 2019 (COVID-19) case rates over time.
Results
For all regions, seroprevalence was <1.0% in March 2020. New York, New York, experienced the biggest increase (peak seroprevalence, 15.8% in May). All other regions experienced modest increases in seroprevalence (1%–2% in May–June to 2%–4% in July–August). Seroprevalence was higher in younger, non-Hispanic black, and Hispanic donors. Temporal increases in donor seroprevalence correlated with reported case rates in each region. In August, 1.3–5.6 estimated cumulative infections (based on seroprevalence data) per COVID-19 case were reported to the Centers for Disease Control and Prevention.
Conclusions
Increases in seroprevalence were found in all regions, with the largest increase in New York. Seroprevalence was higher in non-Hispanic black and Hispanic than in non-Hispanic white blood donors. SARS-CoV-2 antibody testing of blood donor samples can be used to estimate the seroprevalence in the general population by region and demographic group. The methods derived from the RESPONSE seroprevalence study served as the basis for expanding SARS-CoV-2 seroprevalence surveillance to all 50 states and Puerto Rico.
SARS-CoV-2 serosurveillance of blood donors in 6 US regions enabled population weighted seroprevalence estimates. Seroprevelance rates were higher in younger, non-Hispanic Black, and Hispanic donors and correlated with regional case rates. The study has expanded to a national serosurveillance program.
The Single-Incision Power Optimizing Cost-Effective Repair (SPOC) method reattaches the distal biceps tendon to its original posterior anatomic footprint and utilizes the anterior cortex of the ...supinated radius for fixation. The purpose of the study was to define the long-term complications and durability of the SPOC method.
Two hundred and eighteen patients underwent the SPOC repair of distal biceps ruptures from 2008 to 2020, with 185 having at least 1-year follow-up data. The average follow-up was 50.1 months. Information regarding smoking, body mass index, interval between injury and surgery, peripheral nerve injury, heterotopic ossification, vascular injury, re-rupture, chronic regional pain syndrome, fracture of the radius, loss of motion, pain with use, and deformity were acquired.
No complication occurred beyond the third postoperative month. No patient complained of severe lateral antebrachial cutaneous nerve-related symptoms. Major complications exclusive of re-rupture occurred include 1 case of heterotopic ossification and 1 deep infection. Major complications with re-ruptures occurred in 9 patients (4.8%). Seven of the re-ruptures (78%) were associated with an unexpected forceful contraction within the first 4 weeks postop. All complications aside from 1 minor complication occurred in the chronic group. Long term follow-up revealed no re-ruptures and high satisfaction rate with return of strength, motion, and biceps profile.
The safety profile of the SPOC repair is consistent with those of other published repairs. Major complications were associated with prolonged intervals between injury and reconstruction. Re-ruptures were associated with worker’s compensation status and patient noncompliance with postoperative protocols.
For children with asthma, access to quick-relief medications is critical to minimizing morbidity and mortality. An innovative and practical approach to ensure access at school is to maintain a supply ...of stock albuterol that can be used by any student who experiences respiratory distress. To make this possible, state laws allowing for stock albuterol are needed to improve medication access.
To provide policy recommendations and outline steps for passing and implementing stock albuterol laws.
We assembled a diverse stakeholder group and reviewed guidelines, literature, statutes, regulations, and implementation documents related to school-based medication access. Stakeholders were divided into two groups-legislation and implementation-on the basis of expertise. Each group met virtually to review documents and draft recommendations. Recommendations were compiled and revised in iterative remote meetings with all stakeholders.
We offer several recommendations for crafting state legislation and facilitating program implementation.
) Create a coalition of stakeholders to champion legislation and implement stock albuterol programs. The coalition should include school administrators, school nurses and health personnel, parents, or caregivers of children with asthma, pediatric primary care and subspecialty providers (e.g., pulmonologists/allergists), pharmacists, health department staff, and local/regional/national advocacy organizations.
) Legislative components critical for effective implementation of stock albuterol programs include specifying that medication can be administered in good faith to any child in respiratory distress, establishing training requirements for school staff, providing immunity from civil liability for staff and prescribers, ensuring pharmacy laws allow prescriptions to be dispensed to schools, and suggesting inhalers with valved holding chambers/spacers for administration.
) Select an experienced and committed legislator to sponsor legislation and guide revisions as needed during passage and implementation. This person should be from the majority party and serve on the legislature's health or education committee.
) Develop plans to disseminate legislation and regulations/policies to affected groups, including school administrators, school nurses, pharmacists, emergency responders, and primary/subspecialty clinicians. Periodically evaluate implementation effectiveness and need for adjustments.
Stock albuterol in schools is a safe, practical, and potentially life-saving option for children with asthma, whether asthma is diagnosed or undiagnosed, who lack access to their personal quick-relief medication. Legislation is imperative for aiding in the adoption and implementation of school stock albuterol policies, and key policy inclusions can lay the groundwork for success. Future work should focus on passing legislation in all states, implementing policy in schools, and evaluating the impact of such programs on academic and health outcomes.
Antigenic drift, the gradual accumulation of amino acid substitutions in the influenza virus hemagglutinin (HA) receptor protein, enables viral immune evasion. Antibodies (Abs) specific for the ...drift-resistant HA stem region are a promising universal influenza vaccine target. Although anti-stem Abs are not believed to block viral attachment, here we show that complement component 1q (C1q), a 460-kilodalton protein with six Ab Fc-binding domains, confers attachment inhibition to anti-stem Abs and enhances their fusion and neuraminidase inhibition. As a result, virus neutralization activity in vitro is boosted up to 30-fold, and in vivo protection from influenza PR8 infection in mice is enhanced. These effects reflect increased steric hindrance and not increased Ab avidity. C1q greatly expands the anti-stem Ab viral escape repertoire to include residues throughout the HA, some of which cause antigenic alterations in the globular region or modulate HA receptor avidity. We also show that C1q enhances the neutralization activity of non-receptor binding domain anti-SARS-CoV-2 spike Abs, an effect dependent on spike density on the virion surface. These findings demonstrate that C1q can greatly expand Ab function and thereby contribute to viral evolution and immune escape.
Ambient concentrations of the hydroxyl (OH), hydroperoxyl (HO2), and total peroxy (ΣRO2) radicals were measured as part of the Tropospheric OH Photochemistry Experiment at Idaho Hill, Colorado, ...during August and September of 1993. OH radicals were measured using ion‐assisted mass spectroscopy and low‐pressure laser‐induced fluorescence (LIF) detection techniques. HO2 was measured using chemical conversion and LIF detection of OH. ΣRO2 radicals were measured using a chemical amplifier technique. The simultaneous measurements of these key species provide an opportunity to test our present understanding of the fast photochemistry of the troposphere. Measured HO2/OH ratios were typically between 15 and 80, and agreed well with predictions under conditions where NO mixing ratios were greater than 100 pptv. However, under clean conditions the measured ratio was a factor of 3–4 lower than predicted. The RO2/HO2 ratio was typically a factor of 4–15 larger than predicted by present theories of tropospheric chemistry. A steady state model was used in an attempt to analyze the discrepancies between the measured HO2/OH and RO2/HO2 ratios with present theories of hydrocarbon oxidation in the troposphere.
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