A DIO2 missense mutation and its impact on fetal response to PRRSV infection.

BACKGROUND: Porcine reproductive and respiratory syndrome virus 2 (PRRSV-2) infection during late gestation substantially lowers fetal viability and survival. In a previous genome-wide association study, a single nucleotide polymorphism on chromosome 7 was significantly associated with probability of fetuses being viable in response to maternal PRRSV-2 infection at 21 days post maternal inoculation. The iodothyronine deiodinase 2 (DIO2) gene, located ~ 14 Kilobase downstream of this SNP, was selected as a priority candidate related to fetal susceptibility following maternal PRRSV-2 infection. Our objectives were to identify mutation(s) within the porcine DIO2 gene and to determine if they were associated with fetal outcomes after PRRSV-2 challenge. Sequencing of the DIO2, genotyping identified variants, and association of DIO2 genotypes with fetal phenotypes including DIO2 mRNA levels, viability, survival, viral loads, cortisol and thyroid hormone levels, and growth measurements were conducted. RESULTS: A missense variant (p.Asn91Ser) was identified in the parental populations from two independent PRRSV-2 challenge trials. This variant was further genotyped to determine association with fetal PRRS outcomes. DIO2 mRNA levels in fetal heart and kidney differed by the genotypes of Asn91Ser substitution with significantly greater DIO2 mRNA expression in heterozygotes compared with wild-type homozygotes (P < 0.001 for heart, P = 0.002 for kidney). While Asn91Ser did not significantly alter fetal viability and growth measurements, interaction effects of the variant with fetal sex or trial were identified for fetal viability or crown rump length, respectively. However, this mutation was not related to dysregulation of the hypothalamic-pituitary-adrenal and thyroid axis, indicated by no differences in circulating cortisol, T4, and T3 levels in fetuses of the opposing genotypes following PRRSV-2 infection. CONCLUSIONS: The present study suggests that a complex relationship among DIO2 genotype, DIO2 expression, fetal sex, and fetal viability may exist during the course of fetal PRRSV infection. Our study also proposes the increase in cortisol levels, indicative of fetal stress response, may lead to fetal complications, such as fetal compromise, fetal death, or premature farrowing, during PRRSV infection.

Compensatory mechanisms in response to induced hypothyroidism in the late gestation pig fetus†.

To understand the effect of fetal thyroid gland disruption on development in swine, we evaluated thyroid hormone levels, growth and developmental characteristics, and gene expression associated with thyroid hormone metabolism in late gestation fetuses exposed to methimazole (MMI). Pregnant gilts were given either oral MMI or equivalent sham from gestation day 85-106 (n = 4/group), followed by intensive phenotyping of all fetuses (n = 120). Samples of liver (LVR), kidney (KID), fetal placenta (PLC), and the corresponding maternal endometrium (END) were collected from a subset of fetuses (n = 32). Fetuses exposed to MMI in utero were confirmed hypothyroid, with a significant increase in thyroid gland size, goitrous thyroid histology, and dramatically suppressed thyroid hormone in serum. In dams, no differences in temporal measurements of average daily gain, thyroid hormone, or rectal temperatures relative to controls suggests that MMI had little effect on maternal physiology. However, fetuses from MMI-treated gilts exhibited significant increases in body mass, girth, and vital organ weights, but no differences in crown-rump length or bone measurements suggesting non-allometric growth. The PLC and END showed a compensatory decrease in expression of inactivating deiodinase (DIO3). Similar compensatory gene expression was observed in fetal KID and LVR with a downregulation of all deiodinases (DIO1, DIO2, DIO3). Minor alterations in the expression of thyroid hormone transporters (SLC16A2 and SLC16A10) were observed in PLC, KID, and LVR. Collectively, MMI crosses the PLC of the late gestation pig, resulting in congenital hypothyroidism, alterations in fetal growth, and compensatory responses within the maternal fetal interface.

Porcine reproductive and respiratory virus 2 infection of the fetus results in multi-organ cell cycle suppression.

Porcine reproductive and respiratory syndrome virus (PRRSV) infection during late gestation negatively affects fetal development. The objective of this study was to identify the fetal organs most severely impacted following infection, and evaluate the relationship between this response and fetal phenotypes. RNA was extracted from fetal heart, liver, lung, thymus, kidney, spleen, and loin muscle, collected following late gestation viral challenge of pregnant gilts. Initially, gene expression for three cell cycle promoters (CDK1, CDK2, CDK4) and one inhibitor (CDKN1A) were evaluated in biologically extreme phenotypic subsets including gestational age-matched controls (CON), uninfected (UNIF), high-viral load viable (HV-VIA), and high-viral load meconium-stained (HV-MEC) fetuses. There were no differences between CON and UNIF groups for any gene, indicating no impact of maternal infection alone. Relative to CON, high-viral load (HV-VIA, HV-MEC) fetuses showed significant downregulation of at least one CDK gene in all tissues except liver, while CDKN1A was upregulated in all tissues except muscle, with the heart and kidney most severely impacted. Subsequent evaluation of additional genes known to be upregulated following activation of P53 or TGFb/SMAD signaling cascades indicated neither pathway was responsible for the observed increase in CDKN1A. Finally, analysis of heart and kidney from a larger unselected population of infected fetuses from the same animal study showed that serum thyroxin and viral load were highly correlated with the expression of CDKN1A in both tissues. Collectively these results demonstrate the widespread suppression in cell division across all tissues in PRRSV infected fetuses and indicate a non-canonical regulatory mechanism.

Influence of a climatic gradient on genetic exchange between two oak species.

PREMISE: In plant groups with limited intrinsic barriers to gene flow, it is thought that environmental conditions can modulate interspecific genetic exchange. Oaks are known for limited barriers to gene flow among closely related species. Here, we use Quercus as a living laboratory in which to pursue a fundamental question in plant evolution: Do environmental gradients restrict or promote genetic exchange between species? METHODS: We focused on two North American oaks, the rare Quercus dumosa and the widespread Q. berberidifolia. We sampled intensively along a contact zone in California, USA. We sequenced restriction site-associated DNA markers and measured vegetative phenotype. We tested for genetic exchange, the association with climate, and the effect on phenotype. RESULTS: There is evidence for genetic exchange between the species. Admixed plants are found in areas of intermediate climate, while less admixed plants are found at the extremes of the climatic gradient. Genetic and phenotypic patterns are out of phase in the contact zone; some plants display the phenotype of one species but are genetically associated with another. CONCLUSIONS: Our results support the hypothesis that a strong climatic gradient can promote genetic exchange between species. The overall weak correlation between genotype and phenotype in the contact zone between the species suggests that genetic exchange can lead to the breakdown of trait combinations used to define species. This incongruency predicts ongoing problems for conservation of Q. dumosa, with implications for conservation of other oaks.

Planarians as models of cadmium-induced neoplasia provide measurable benchmarks for mechanistic studies.

Bioassays of planarian neoplasia highlight the potential of these organisms as useful standards to assess whether environmental toxins such as cadmium promote tumorigenesis. These studies complement other investigations into the exceptional healing and regeneration of planarians - processes that are driven by a population of active stem cells, or neoblasts, which are likely transformed during planarian tumor growth. Our goal was to determine if planarian tumorigenesis assays are amenable to mechanistic studies of cadmium carcinogenesis. To that end we demonstrate, by examining both counts of cell populations by size, and instances of mitosis, that the activity of the stem cell population can be monitored. We also provide evidence that specific biomodulators can affect the potential of planarian neoplastic growth, in that an inhibitor of metalloproteinases effectively blocked the development of the lesions. From these results, we infer that neoblast activity does respond to cadmium-induced tumor growth, and that metalloproteinases are required for the progression of cancer in the planarian.

Impact of methimazole-induced hypothyroidism on postnatal swine.

Thyroid hormones regulate metabolic rate, nutrient utilization, growth, and development. Swine are susceptible to thyroid suppression in response to disease or environmental conditions, but the physiological impact of such disruption has not been established. The objective of this study was to evaluate the impact of hypothyroidism induced with the antithyroid medication methimazole (MMI). 10 mg/kg MMI significantly decreased circulating triiodothyronine (T3) for the duration of treatment but had only a transient effect on circulating thyroxine (T4). Thyroid tissue weight was significantly increased by more than 3.5-fold in response to MMI treatment. Histologically, the eosinophilic colloid was largely absent from the thyroid follicle which displayed a disorganized columnar epithelium consistent with goiter. MMI induced hypothyroidism has no effect on growth rate over 28 days. Hepatic expression of genes associated with thyroid metabolism (DIO1, DIO2, and DIO3), lipid utilization (CD36, FASN, and ACACA), apoptosis (TP53, PERP, SIVA1, and SFN) and proliferation (CDK1, CDK2, CDK4, and CDKN1A) were unaffected by treatment. Collectively these results demonstrate that MMI induces mild systemic hypothyroidism and pronounced goiter, indicating a strong homeostatic central regulation within the hypothalamic pituitary thyroid axis. This combined with limited peripheral effects, indicates resilience to hypothyroidism in modern swine.

An Early Evaluation of Remote Site Visits for ACGME Program Applications.

Background: Prior to the COVID-19 pandemic, accreditation site visit interviews occurred in-person. In response to the pandemic, the Accreditation Council for Graduate Medical Education (ACGME) developed a remote site visit protocol. Objective: To perform an early assessment of the remote accreditation site visits for programs applying for initial ACGME accreditation. Methods: A cohort of residency and fellowship programs that had remote site visits was evaluated from June to August 2020. Surveys were sent to program personnel, ACGME accreditation field representatives, and executive directors following the site visits. Comparison of accreditation decisions (Initial Accreditation or Accreditation Withheld) was completed for matched residency or fellowship programs having in-person site visits in 2019. Results: Surveys were sent to all program personnel from the 58 residency and fellowship programs that had remote site visits for new program applications, as well as the accreditation field representatives who performed the remote visits. The survey response rate was 58% (352 of 607). Ninety-one percent of all respondents were extremely or very confident that remote site visits provided a thorough assessment of proposed residency or fellowship programs. Fifty-four programs having remote site visits were matched by specialty to programs having had in-person program application site visits in 2019. Forty-six programs that had remote site visits received Initial Accreditation, and 52 programs that had in-person site visits in 2019 received Initial Accreditation (P=.093, 95% CI 0.91-22.38). Conclusions: Most program personnel and accreditation field representatives were confident that remote site visits conducted for program applications provided fair and thorough assessments of the program.

Upgrade Rate of Pure Flat Epithelial Atypia Diagnosed at Core Needle Biopsy: A Systematic Review and Meta-Analysis.

Purpose: To perform a systematic review and meta-analysis to calculate the pooled upgrade rate of pure flat epithelial atypia (FEA) diagnosed at core needle biopsy (CNB). Materials and Methods: A PubMed and Embase database search was performed in December 2019. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Study quality and publication bias were assessed. The upgrade rate of pure FEA to cancer, invasive carcinoma, and ductal carcinoma in situ (DCIS), as well as the co-occurrence rate of atypical ductal hyperplasia (ADH), with 95% CIs were calculated. A random effect model was used to integrate the proportions and their corresponding 95% CI. Study heterogeneity was calculated using τ2 and I 2 . Results: A total of 2482 cases of pure FEA across 42 studies (mean age range, 46-59 years) met inclusion criteria to be analyzed. Significant study heterogeneity was identified (τ2 = 0.001, I 2 = 67%). The pooled upgrade rates reported for pure FEA were 5% (95% CI: 3%, 6%) for breast cancer, 1% (95% CI: 0%, 2%) for invasive carcinoma, and 2% (95% CI: 1%, 3%) for DCIS. When more than 90% of calcifications were removed at CNB, the pooled upgrade rate was 0% (95% CI: 0%, 2%). The pooled co-occurrence rate of ADH at surgical excision was 17% (95% CI: 12%, 21%). Study quality was medium to high with a risk of publication bias (P < .01). Conclusion: Pure FEA diagnosed at CNB should be surgically excised due to the pooled upgrade rate of 5% for breast cancer. If more than 90% of the targeted calcifications are removed by CNB for pure FEA, close imaging follow-up is recommended.Keywords: Biopsy/Needle Aspiration, Breast, MammographySupplemental material is available for this article.© RSNA, 2021.

The cognitive effects of chemotherapy in post-menopausal breast cancer patients: a controlled longitudinal study.

Studies suggest that adjuvant chemotherapy for early stage breast cancer (BC) is associated with cognitive impairment related to attention, memory, and visuospatial functioning. However, other studies have failed to confirm that relationship. We report one of the first longitudinal, controlled studies of cognitive effects of chemotherapy in older post-menopausal women. Sixty-one post-menopausal women with non-metastatic BC were administered neuropsychological tests before adjuvant therapy (Time1), six months after treatment (Time2), and at a final 6-month follow-up (Time3). Thirty women were treated with chemotherapy; thirty-one women who received no chemotherapy were controls. Cognitive domains measured included motor, language, attention/concentration/working memory, visuospatial, and memory (verbal and visual). Time-by-treatment interaction was significant in the motor domain (P = 0.007) with poorer performance in women treated with chemotherapy. For the other domains, scores did not significantly vary over time by group. In post-menopausal women, chemotherapy was not associated with changes in cognitive function in areas reported by BC survivors: attention, memory, and information processing. Motor slowing in women treated with chemotherapy could be secondary to peripheral neuropathy rather than an indication of more general declines in cognitive processing. Future studies should control for the independent effects of slowed motor functioning when looking to study possible chemotherapy related cognitive processing deficits.

Guarana provides additional stimulation over caffeine alone in the planarian model.

The stimulant effect of energy drinks is primarily attributed to the caffeine they contain. Many energy drinks also contain other ingredients that might enhance the tonic effects of these caffeinated beverages. One of these additives is guarana. Guarana is a climbing plant native to the Amazon whose seeds contain approximately four times the amount of caffeine found in coffee beans. The mix of other natural chemicals contained in guarana seeds is thought to heighten the stimulant effects of guarana over caffeine alone. Yet, despite the growing use of guarana as an additive in energy drinks, and a burgeoning market for it as a nutritional supplement, the science examining guarana and how it affects other dietary ingredients is lacking. To appreciate the stimulant effects of guarana and other natural products, a straightforward model to investigate their physiological properties is needed. The planarian provides such a system. The locomotor activity and convulsive response of planarians with substance exposure has been shown to provide an excellent system to measure the effects of drug stimulation, addiction and withdrawal. To gauge the stimulant effects of guarana we studied how it altered the locomotor activity of the planarian species Dugesia tigrina. We report evidence that guarana seeds provide additional stimulation over caffeine alone, and document the changes to this stimulation in the context of both caffeine and glucose.