Views on the impact of the COVID-19 pandemic on health in people with Down syndrome from diverse backgrounds.

Down syndrome (DS) has a unique medical and psychological profile. To date, few studies have asked individuals with DS about their views of health, and fewer have explored the impact of COVID-19 on the health of individuals with DS and their families. We used a mixed methods approach including two studies on the health of individuals with DS and their parents conducted during the COVID-19 pandemic: (1) eight virtual focus groups, comprised of 20 parents and 8 individuals with DS to obtain participants' views of health, and (2) a 20-item questionnaire on health care experience of patients with DS who are African American or come from primarily Spanish-speaking homes. Focus group transcripts were coded using a hybrid inductive/deductive framework and thematically analyzed using the Framework Method. This questionnaire included questions regarding the impact of COVID-19 on caregivers and their loved ones with DS; responses to these questions were summarized using descriptive statistics. Individuals with DS discussed the impact of the COVID-19 pandemic on their physical and social health including masking, online learning, and online communication with friends and family. Parents of individuals with DS discussed how the COVID-19 pandemic negatively impacted their child's physical, social, and mental health, as a result of virtual schooling and decreased socialization. There were unexpected positives of the pandemic such as improved hygiene and eased scheduling with telehealth visits. Caregivers noted COVID-19 impacted their own anxiety, employment, and other domains that have potential ripple effects on the health of their children. The COVID-19 pandemic had a pervasive impact on the mental health and wellness of caregivers as well as the physical, social, and mental health of individuals with DS.

Healthcare experiences of patients with Down syndrome from primarily Spanish-speaking households.

We report on the health care experiences of individuals with Down syndrome (DS) from families who are primarily Spanish-speaking. Data were collected through three methods: (1) a nationally distributed, 20-item survey, (2) two focus groups with seven family caregivers of individuals with DS who self-identified as living in primarily Spanish speaking households, and (3) 20 interviews with primary care providers (PCPs) who care for patients who are underrepresented minorities. Standard summary statistics were used to analyze the quantitative survey results. Focus group and interview transcripts, as well as an open-ended response question in the survey, were analyzed using qualitative coding methods to identify key themes. Both caregivers and PCPs described how language barriers make giving and receiving quality care difficult. Caregivers additionally described condescending, discriminatory treatment within the medical system and shared feelings of caregiver stress and social isolation. Challenges to care experienced by families of individuals with DS are compounded for Spanish-speaking families, where the ability to build trust with providers and in the health care system may be compromised by cultural and language differences, systemic issues (lack of time or inability to craft more nuanced schedules so that patients with higher needs are offered more time), mistrust, and sometimes, overt racism. Building this trust is critical to improve access to information, care options, and research opportunities, especially for this community that depends on their clinicians and nonprofit groups as trusted messengers. More study is needed to understand how to better reach out to these communities through primary care clinician networks and nonprofit organizations.

Healthcare experiences of patients with Down syndrome who are Black, African American, of African descent, or of mixed race.

Scant research has explored the healthcare experiences of people with Down syndrome (DS) in the United States who are Black, African American, of African descent, or of mixed race. The purpose of this study was to identify and describe the barriers and facilitators that such patients and their caregivers face when accessing healthcare. We gathered data in three ways: focus groups with caregivers, a national survey completed by caregivers, and in-depth interviews with primary care providers. Many caregivers and primary care physicians felt that patients with DS who are Black, African American, of African descent, or of mixed race receive a lower quality of medical care than their white counterparts with DS. Caregivers mentioned feeling tired of being reminded by the medical community about their race and wanting acknowledgment that raising a child with DS can be hard at times. Many felt that the medical community's conscious and unconscious racial biases do negatively impact the care of their loved ones with DS. Caregivers desired more race concordant medical providers or, when not possible, medical providers who are willing to learn more about DS and build trusted, longitudinal relationships. Primary care providers discussed the need for funded resources and support services to effectively care for their patients with DS.

Solubility behavior and prediction for antihelmintics at several temperatures in aqueous and nonaqueous mixtures.

A model based on solubility parameters is proposed to predict the solubility curves of antihelmintic drugs at several temperatures, including aqueous and non-aqueous mixtures. The solubility of the drugs was measured in ethanol-water and ethanol-ethyl acetate mixtures at 15-35 degrees C (mebendazole) and at 25 degrees C (thiabendazole and metronidazole). The solid phases were analyzed by differential scanning calorimerty. The polymorphic form A of mebendazole was also characterized from infrared spectroscopy. Markedly different solubility profile shapes were obtained against the solubility parameter of the mixtures: two symmetrical peaks (metronidazole), two maxima of different height (mebendazole) and a single peak (thiabendazole). The solubility parameter of the drugs was related to the co-solvent action of both mixtures and to the solubility peaks. The single equation proposed was able to predict solubility profiles of different shape, including both mixtures and all temperatures, providing reasonable physical meaning for the regression coefficients. The model was successfully tested for its predictive capability using a limited number of experimental data. More than 100 solubilities were predicted at several temperatures using 20 data point for each drug.

Kidins220/ARMS downregulation by excitotoxic activation of NMDARs reveals its involvement in neuronal survival and death pathways.

Functional and protein interactions between the N-methyl-D-aspartate type of glutamate receptor (NMDAR) and neurotrophin or ephrin receptors play essential roles in neuronal survival and differentiation. A shared downstream effector for neurotrophin- and ephrin-receptor signaling is kinase D-interacting substrate of 220 kDa (Kidins220), also known as ankyrin repeat-rich membrane spanning (ARMS). Because this molecule is obligatory for neurotrophin-induced differentiation, we investigated whether Kidins220/ARMS and NMDAR functions were related. Here, we identify an association between these proteins and discover that excitotoxicity, a specific form of neuronal death induced by NMDAR overstimulation, dramatically decreases Kidins220/ARMS levels in cortical neurons and in a model of cerebral ischemia. Kidins220/ARMS downregulation is triggered by overactivation of NMDARs containing NR2B subunits and subsequent Ca(2+) influx, and involves a dual mechanism: rapid cleavage by the Ca(2+)-dependent protease calpain and calpain-independent silencing of Kidins220/Arms gene transcription. Additionally, Kidins220/ARMS knockdown decreases ERK activation and basal neuronal viability, and enhances neuronal death under excitotoxic conditions. Our results demonstrate Kidins220/ARMS participation in neuronal life and death pathways, and constitute the first report of its regulation under pathological conditions.

Transcription of the NR1 subunit of the N-methyl-D-aspartate receptor is down-regulated by excitotoxic stimulation and cerebral ischemia.

The N-methyl-D-aspartate (NMDA) type of glutamate receptor (NMDAR) plays central roles in normal and pathological neuronal functioning. We have examined the regulation of the NR1 subunit of the NMDAR in response to excessive activation of this receptor in in vitro and in vivo models of excitotoxicity. NR1 protein expression in cultured cortical neurons was specifically reduced by stimulation with 100 microM NMDA or glutamate. NMDA decreased NR1 protein amounts by 71% after 8 h. Low NMDA concentrations (< or = 10 microM) had no effect. NR1 down-regulation was inhibited by the general NMDAR antagonist DL-AP5 and also by ifenprodil, which specifically antagonizes NMDARs containing NR2B subunits. Arrest of NMDAR signaling with DL-AP5 after brief exposure to NMDA did not prevent subsequent NR1 decrease. Down-regulation of NR1 did not involve calpain cleavage but resulted from a decrease in de novo synthesis consequence of reduced mRNA amounts. In contrast, NMDA did not alter the expression of NR2A mRNA or newly synthesized protein. In neurons transiently transfected with an NR1 promoter/luciferase reporter construct, promoter activity was reduced by 68% after 2 h of stimulation with NMDA, and its inhibition required extracellular calcium. A similar mechanism of autoregulation of the receptor probably operates during cerebral ischemia, because NR1 mRNA and protein were strongly decreased at early stages of blood reperfusion in the infarcted brains of rats subjected to occlusion of the middle cerebral artery. Because NR1 is the obligatory subunit of NMDARs, this regulatory mechanism will be fundamental to NMDAR functioning.

What are the effects of maternal and pre-adult environments on ageing in humans, and are there lessons from animal models?

An open issue in research on ageing is the extent to which responses to the environment during development can influence variability in life span in animals, and the health profile of the elderly in human populations. Both affluence and adversity in human societies have profound impacts on survivorship curves, and some of this effect may be traceable to effects in utero or in infancy. The Barker Hypothesis that links caloric restriction in very early life to disruptions of glucose-insulin metabolism in later life has attracted much attention, as well as some controversy, in medical circles. It is only rarely considered by evolutionary biologists working on phenotypic plasticity, or by biogerontologists studying model organisms such as C. elegans or Drosophila. One crucial mechanism by which animals can respond in an adaptive manner to adverse conditions, for example in nutrition or infection, during development is phenotypic plasticity. Here we begin with a discussion of adaptive plasticity in animals before asking what such phenomena may reveal of relevance to rates of ageing in animals, and in humans. We survey the evidence for effects on adult ageing of environmental conditions during development across mammalian and invertebrate model organisms, and ask whether evolutionary conserved mechanisms might be involved. We conclude that the Barker Hypothesis is poorly supported and argue that more work in human populations should be integrated with multi-disciplinary studies of ageing-related phenomena in experimental populations of different model species that are subjected to nutritional challenges or infections during pre-adult development.

Unliganded thyroid hormone receptor beta1 inhibits proliferation of murine fibroblasts by delaying the onset of the G1 cell-cycle signals.

Thyroid hormone receptors (TRs) are members of the ligand-inducible transcription factor superfamily. The two major functional TRs (alpha1 and beta1) have different spatial and temporal expression patterns and specific physiological functions for these isoforms are now starting to emerge. By expressing these TR isoforms individually in Swiss 3T3 fibroblasts, we found that TRbeta1 expression, in the absence of hormone, provokes a proliferation arrest in G0/G1, lengthening the cycling time. Upon serum stimulation TRbeta1-expressing cells showed a marked delay in the induction of cyclins D and E, in the phosphorylation of retinoblastoma protein, and in the activation of cyclin-dependent kinase 2, accompanied by increased levels of cyclin-dependent kinase inhibitor p27Kip1. Accordingly, serum-stimulated E2F-1 transcriptional activity was repressed by TRbeta1 in transient transfection experiments. Analysis of the receptor domains required for this effect confirmed that there is no need for a functional ligand-binding domain while the DNA-binding domain is essential. In this work, we demonstrate for the first time that TRbeta1 participates in the molecular mechanisms that control cell proliferation. The unliganded TRbeta1 impairs the normal induction of the G1/S cycle regulators preventing progression into the S phase.

Expression of the neurotrophin receptor trkB is regulated by the cAMP/CREB pathway in neurons.

trkB as receptor for neurotrophins brain-derived neurotrophic factor (BDNF)/neurotrophin (NT)-4/5 plays a crucial role during development, maintenance of the adult brain, and its adaptation to injury or pathological conditions. In spite of this, very little is known about the mechanisms that regulate its expression. Here, we show that forskolin (Fk) rapidly stimulates the expression of both the full-length and truncated trkB isoforms in primary cultures of cortical neurons. Gel shift assays and transient transfection experiments demonstrate that this activation occurs via a protein kinase A (PKA)/cyclic AMP-responsive element-binding protein (CREB)-dependent mechanism. Activated CREB binds to the second cyclic AMP (cAMP)-responsive element (CRE) of the two CRE sites located within the P2 promoter of the trkB gene, which is able to confer cAMP responsiveness to a heterologous promoter. Our results illustrate that the trkB gene is a target for CREB regulation and explain the increase of trkB expression produced in different adaptative responses of the nervous system where CREB is participating.

Expression of thyroid hormone receptor isoforms in the oligodendrocyte lineage.

Thyroid hormone (T3) regulates brain development and function and in particular ensures normal myelination. Animal models and in vitro systems have been employed to demonstrate the effects of T3, which acts via nuclear hormone receptors. T3 receptors (TRs) are transcription factors that activate or suppress target gene expression, such as myelin basic protein (MBP), in a hormone-dependent or -independent fashion. Two distinct genes, TR alpha and TR beta, encode several receptor isoforms with specific functions. This overview summarizes current knowledge on the cellular expression and the role of these isoforms and also examines the action of T3 on oligodendrocyte lineage cell types at defined developmental stages. Re-expression of TRs and also that of other transcription factors in oligodendrocytes may constitute some of the metabolic changes required for succesfull remyelination in the adult central nervous system after demyelinating lesions.

Thyroid hormone increases transcription of GA-binding protein/nuclear respiratory factor-2 alpha-subunit in rat liver.

Thyroid hormone (TH) regulates mitochondrial respiratory rate by activating coordinated transcription in the nucleus and mitochondria. Whereas TH activates transcription of mitochondrial genes directly, the activation of nuclear-encoded mitochondrial genes is probably executed by indirect unknown mechanisms. Nuclear respiratory factors (NRF)-1 and GA-binding protein (BP)/NRF-2 may function as transacting genes, but regulation of these genes by TH is not demonstrated. We show that TH administration to hypothyroid rats promptly increases GABP/NRF-2 alpha-subunit mRNA levels in the liver, without significant changes in beta, gamma subunits. In run-on and time-course experiments, the transcription rate and protein levels increased three-fold in response to TH, indicating GABP/NRF-2 transcriptional regulation. The results also support the notion that ATP synthase beta-subunit is regulated by TH through the indirect activation of GABP/NRF-2.

Coexpression of thyroid hormone receptor isoforms in mouse oligodendrocytes.

Double and triple immunocytochemistry with stage-specific markers and specific antireceptor antibodies was used to study expression of nuclear thyroid hormone receptor (TR) isoforms in cultured mouse oligodendrocytes. To evaluate the coexpression of each TR isoform, antibodies were raised in rabbits and mice against specific regions of alpha1-TR and alpha2-TR common to both alpha isoforms and beta1-TR. Their specificities were assessed by Western blotting and by immunocytochemistry on rat hepatocytes. Oligodendrocyte subpopulations were found to coexpress the alpha- and beta1-TR epitopes at defined developmental stages. Both alpha- and beta1-TR isoforms are colocalized in oligodendrocytes during an early stage identified by the marker OL-1, before 2',3'-cyclic nucleotide 3'-phosphohydrolase is expressed. Expression of beta1-TR varies during maturation, and that of alpha-TR decreases during terminal maturation.