Racial Disparities in Total Knee and Hip Arthroplasty in a Medically Underserved Community with a Diverse Population.

INTRODUCTION: Previous studies have demonstrated lower total joint arthroplasty utilization rates and worse postoperative outcomes among non-White patients. Our study examined whether these disparities exist in the setting of a diverse population. METHODS: This retrospective study included patients with a self-reported race who underwent total knee (TKA) or hip (THA) arthroplasty procedures in a racially diverse county. Patients who did not identify as White or Hispanic/Latino were excluded from the study due to small sample sizes. Demographic, intra and postoperative outcome differences were calculated. A multivariate logistic regression was developed to examine the association between patients' race and undesired postoperative outcomes. RESULTS: Five hundred fifty-five patients were included in our study with 490 identifying as non-Hispanic/Latino White (88.8%) and 65 as Hispanic/Latino (11.2%). Hispanic/Latino-identifying patients were significantly younger (61.9 ± 12.79 versus 68.58 ± 9.00 years), had lower Charlson Comorbidity Index scores, and were more likely to use non-Medicare/Medicaid insurance. We observed no differences between our cohorts in postoperative adverse events, emergency department visits, and hospital readmissions. Patients' self-identified race was not correlated with undesired postoperative outcomes. CONCLUSIONS: Although Hispanic/Latino-identifying patients constitute 50.2% of the county population of our study cohort, they accounted for only 11.2% of the patients in our study. This is noteworthy considering the lack of evidence suggesting a decreased prevalence of osteoarthritis among individuals of different races and ethnicities. Further, the demographic differences we observed suggest an exclusive Hispanic/Latino patient population utilizing TKA or THA procedures. Future studies controlling for risk factors and less invasive treatment options may explain these disparities.

Role of lncRNAs and circRNAs in Orofacial Clefts.

Different modes of gene regulation, such as histone modification, transcription factor binding, DNA methylation, and microRNA (miRNA) expression, are critical for the spatiotemporal expression of genes in developing orofacial tissues. Aberrant regulation in any of these modes may contribute to orofacial defects. Noncoding RNAs (ncRNAs), such as long ncRNAs (lncRNAs) and circular RNAs (circRNAs), have been shown to alter miRNA expression, and are thus emerging as novel contributors to gene regulation. Some of these appear to function as 'miRNA sponges', thereby diminishing the availability of these miRNAs to inhibit the expression of target genes. Such ncRNAs are also termed competitive endogenous RNAs (ceRNAs). Here, we examine emerging data that shed light on how lncRNAs and circRNAs may alter miRNA regulation, thus affecting orofacial development and potentially contributing to orofacial clefting.

MicroRNA-Mediated Regulation of BMP Signaling in the Developing Neural Tube.

BACKGROUND: Neural tube (NT) morphogenesis is reliant on the proper temporospatial expression of numerous genes and synchronized crosstalk between diverse signaling cascades and gene regulatory networks governing key cellular processes. MicroRNAs (miRNAs), a group of small non-coding regulatory RNAs, execute defining roles in directing key canonical pathways during embryogenesis. OBJECTIVE: In order to comprehend the mechanistic underpinnings of miRNA regulation of NT morphogenesis, we have identified in the current study various miRNAs and their target mRNAs associated with BMP signaling during critical stages of neurulation. METHODS: We previously demonstrated the expression of several miRNAs during the critical stages of neurulation (gestational days (GD) 8.5, 9.0, and 9.5) employing high-sensitivity, high-coverage microarrays. In the present study, bioinformatic analyses were used to identify miRNAs differentially expressed (DE) in the embryonic NT that target messenger RNAs (mRNAs) associated with the bone morphogenetic protein (BMP) signaling pathway. RNAs extracted from the developing NT were hybridized to both miRNA and mRNA arrays to evaluate miRNA-mRNA interactions. RESULTS: Bioinformatic analysis identified several DE miRNAs that targeted mRNAs encoding members of (and proteins associated with) the BMP signaling pathway - a signaling cascade central to normal NT development. CONCLUSION: Identification of the miRNAs and their mRNA targets associated with BMP signaling facilitates a better understanding of the crucial epigenetic mechanisms underlying normal NT development as well as the pathogenesis of NT defects. The current study supports the notion that miRNAs function as key regulators of neural tube morphogenesis via modulation of the BMP signaling cascade. Altered expression of these miRNAs during neurulation may therefore result in NT defects.

Spatiotemporal Expression and Functional Analysis of miRNA-22 in the Developing Secondary Palate.

OBJECTIVE: Normal development of the embryonic orofacial region requires precise spatiotemporal coordination between numerous genes. MicroRNAs represent small, single-stranded, non-coding molecules that regulate gene expression. This study examines the role of microRNA-22 (miR-22) in murine orofacial ontogeny. METHODS: Spatiotemporal and differential expression of miR-22 (mmu-miR-22-3p) within the developing secondary palate was determined by in situ hybridization and quantitative real-time PCR, respectively. Bioinformatic approaches were used to predict potential mRNA targets of miR-22 and analyze their association with cellular functions indispensable for normal orofacial ontogeny. An in vitro palate organ culture system was used to assess the role of miR-22 in secondary palate development. RESULTS: There was a progressive increase in miR-22 expression from GD12.5 to GD14.5 in palatal processes. On GD12.5 and GD13.5, miR-22 was expressed in the future oral, nasal, and medial edge epithelia. On GD14.5, miR-22 expression was observed in the residual midline epithelial seam (MES), the nasal epithelium and the mesenchyme, but not in the oral epithelium. Inhibition of miR-22 activity in palate organ cultures resulted in failure of MES removal. Bioinformatic analyses revealed potential mRNA targets of miR-22 that may play significant roles in regulating apoptosis, migration, and/or convergence/extrusion, developmental processes that modulate MES removal during palatogenesis. CONCLUSIONS: Results from the current study suggest a key role for miR-22 in the removal of the MES during palatogenesis and that miR-22 may represent a potential contributor to the etiology of cleft palate.

Dihydropyridine calcium blockers do not interfere with non-rapid eye movement sleep.

Non-rapid eye movement (NREM) sleep is tightly homeostatically regulated and essential for survival. In the electroencephalogram (EEG), oscillations in the delta (0.5-4 Hz) range are prominent during NREM sleep. These delta oscillations are, to date, the best indicator for homeostatic sleep regulation; they are increased after prolonged waking and fade during NREM sleep. The precise mechanisms underlying sleep homeostasis and the generation of EEG delta oscillations are still being investigated. Activity-dependent neuronal calcium influx has been hypothesized to play an important role in generating delta oscillations and might be involved in downstream signaling that mediates sleep function. Dihydropyridine blockers of L-type voltage-gated calcium channels (VGCCs) are in wide clinical use to treat hypertension and other cardiovascular disorders and are readily blood-brain-barrier penetrant. We therefore, wanted to investigate their potential effects on EEG delta oscillation and homeostatic NREM sleep regulation in freely behaving mice. In vivo two-photon imaging of cortical neurons showed larger spontaneous calcium transients in NREM sleep compared to waking. Application of the dihydropyridine calcium blocker nicardipine significantly reduced cortical calcium transients without affecting the generation of delta oscillations. Nicardipine also did not affect EEG delta oscillations over 24 h following application. The time spent in NREM sleep and NREM episode duration was also not affected. Thus, acute block of calcium entry through L-type VGCCs does not interfere with EEG delta oscillations or their homeostatic regulation, despite prior evidence from calcium channel knockout mice.

Arousal-Mediated Sleep Disturbance Persists During Cocaine Abstinence in Male Mice.

Acute cocaine disturbs sleep on a dose-dependent basis; however, the consequences of chronic cocaine remain unclear. While the arousal promotion following cocaine has been well-established, effects of cocaine on sleep after termination of chronic cocaine exposure appear variable in human subjects with few studies in non-human subjects. Here, a within-subjects design (outcomes normalized to baseline, undisturbed behavior) and between-subjects design (repeated experimenter-administered cocaine vs. experimenter-administered saline) was used to investigate sleep homeostasis and sleep/waking under repeated cocaine/saline exposure and prolonged forced abstinence conditions in mice. Overall, during the forced abstinence period increases in arousal, as determined by sleep latency and gamma energy, persisted for 2 weeks. However, the sleep response to externally enforced sleep deprivation was unchanged suggesting that sleep disruptions during the forced abstinence period were driven by enhancement of arousal in the absence of changes in sleep homeostatic responses.

MicroRNAs as epigenetic regulators of orofacial development.

Environmental and genetic factors contribute significantly to the etiology of orofacial clefting, which is one of the most common of human congenital craniofacial malformations. Current biological thought now recognizes that epigenetics represents a fundamental contributing process in embryogenesis. Indeed, many of the mechanisms whereby environmental insults affect key pathways crucial for proper embryonic growth and development are increasingly thought to be mediated via the epigenome. Epigenetic regulators, such as microRNAs (miRNAs), play vital roles in the ontogeny of the orofacial region. Evidence for this comes from conditional knockouts of Dicer or DGCR8, genes encoding key enzymes in the miRNA biosynthetic machinery, in neural crest cells. Such knockouts result in a range of craniofacial/orofacial anomalies, including cleft palate and cleft lip. Epigenetic pathways may thus represent key vehicles in the regulation, and misregulation, of gene expression during normal and abnormal orofacial embryogenesis. Significant strides have been made in the last decade in identifying miRNAs and their target genes involved in lip and palate morphogenesis. Such morphogenetic processes include apoptosis, cell proliferation, cell differentiation, and epithelial-mesenchymal transition (EMT). While some of the miRNA-target gene interactions have been functionally validated, many exhibit causal relationships that await functional confirmation. A plethora of genes associated with cleft palate/cleft lip have now been identified that provides a veritable treasure trove of information that could be harnessed to identify novel miRNA candidates for further analysis. In this review, we summarize studies identifying miRNAs involved in various aspects of lip and palate morphogenesis and whose aberrant expression may result in orofacial clefts.

MicroRNAs as Biomarkers for Birth Defects.

It is estimated that 2-4% of live births will have a birth defect (BD). The availability of biomarkers for the prenatal detection of BDs will facilitate early risk assessment, prompt medical intervention and ameliorating disease severity. miRNA expression levels are often found to be altered in many diseases. There is, thus, a growing interest in determining whether miRNAs, particularly extracellular miRNAs, can predict, diagnose, or monitor BDs. These miRNAs, typically encapsulated in exosomes, are released by cells (including those of the fetus and placenta) into the extracellular milieu, such as blood, urine, saliva and cerebrospinal fluid, thereby enabling interaction with target cells. Exosomal miRNAs are stable, protected from degradation, and retain functionality. The observation that placental and fetal miRNAs can be detected in maternal serum, provides a strong rationale for adopting miRNAs as noninvasive prenatal biomarkers for BDs. In this mini-review, we examine the current state of research involving the use of miRNAs as prognostic and diagnostic biomarkers for BD.

The Key Role of Patient Involvement in the Development of Core Outcome Sets in Prostate Cancer.

Patients are the stewards of their own care and hence their voice is important when designing and implementing research. Patients should be involved not only as participants in research that impacts their care, as the recipients of that care and any associated harms, but also as research collaborators in prioritising important questions from the patient perspective and designing the research and the ways in which is it most appropriate to involve patients. The PIONEER Consortium, an international multistakeholder collaboration lead by the European Association of Urology, has developed a core outcome set (COS) for localised and metastatic prostate cancer relevant to all stakeholders in particular patients. Throughout the work of PIONEER, patient representatives were involved as collaborators in setting the research agenda, and a wider group of patients was involved as participants in developing COSs, for instance in consensus meetings on choosing important outcomes and appropriate definitions. This publication showcases the process for COS development and highlights the most important recommendations to ultimately inform future research projects co-created between patients and other stakeholders. PATIENT SUMMARY: An important step in involving patients in the selection of outcomes for clinical trials, clinical audits, and real-world evidence is the development of a core outcome set (COS) that is relevant to all stakeholders. This report highlights the patient participation throughout our PIONEER COS development. TAKE HOME MESSAGE: An important step in involving patients in the selection of outcomes for clinical trials, clinical audits, and real-world evidence is to develop a core outcome set (COS) that is relevant to all stakeholders. As part of the work of the PIONEER Consortium, we aim to highlight the patient participation throughout our PIONEER COS development.

Interaction between cocaine use and sleep behavior: A comprehensive review of cocaine's disrupting influence on sleep behavior and sleep disruptions influence on reward seeking.

Dopamine, orexin (hypocretin), and adenosine systems have dual roles in reward and sleep/arousal suggesting possible mechanisms whereby drugs of abuse may influence both reward and sleep/arousal. While considerable variability exists across studies, drugs of abuse such as cocaine induce an acute sleep loss followed by an immediate recovery pattern that is consistent with a normal response to loss of sleep. Under more chronic cocaine exposure conditions, an abnormal recovery pattern is expressed that includes a retention of sleep disturbance under withdrawal and into abstinence conditions. Conversely, experimentally induced sleep disturbance can increase cocaine seeking. Thus, complementary, sleep-related therapeutic approaches may deserve further consideration along with development of non-human models to better characterize sleep disturbance-reward seeking interactions across drug experience.

Spoken narrative comprehension for young adult listeners: effects of competing voices and noise.

OBJECTIVE: To examine the influence of competing voices or noise on the comprehension of spoken narratives for young adults. DESIGN: First, an intelligibility assessment of the target narratives was conducted to establish a signal-to-noise ratio ensuring accurate initial speech recognition. Then, narrative comprehension for two target types (fixed and varied target talker) was measured in four listening conditions (quiet, one-talker speech, speech babble, speech-shaped noise). After hearing target narratives in each listening condition, participants completed a visual recognition memory task that assessed the comprehension of the narrative materials at three levels of representation (surface form, propositional, event model). STUDY SAMPLE: Seventy adults (18-32 years of age). RESULTS: Narrative comprehension results revealed a main effect of listening condition at the event model level, indicating poorer narrative memory of described situations for all noise conditions compared to quiet. Increased positive responses to thematically consistent but situationally "wrong" memory probes drove this effect. No other significant effects were observed. CONCLUSION: Despite near-perfect speech recognition, background noise negatively influenced aspects of spoken narrative comprehension and memory. Specifically, noise did not disrupt memory for what was said (surface form and propositional memory), but only memory for what was talked about (event model memory).

Norepinephrine transporter antagonism prevents dopamine-dependent synaptic plasticity in the mouse dorsal hippocampus.

The rodent dorsal hippocampus is essential for episodic memory consolidation, a process heavily modulated by dopamine D1-like receptor (D1/5R) activation. It was previously thought that the ventral tegmental area provided the only supply of dopamine release to dorsal hippocampus, but several recent studies have established the locus coeruleus (LC) as the major source for CA1. Here we show that selective blockade of the norepinephrine transporter (NET) prevents dopamine-dependent, late long-term synaptic potentiation (LTP) in dorsal CA1, a neural correlate of memory formation that relies on LC-mediated activation of D1/5Rs. Since dopamine activation of D1/5Rs by vesicular release is expected to be enhanced by NET antagonism, our data identify NET reversal as a plausible mechanism for LC-mediated DA release. We also show that genetic deletion of LC NMDA receptors (NMDARs) blocks D1R-mediated LTP, suggesting the requirement of both a functional NET and presynaptic NMDARs for this release. As LC activity is highly correlated with attentional processes and memory, these experiments provide insight into how selective attention influences memory formation at the synaptic and circuit levels.

Sleep Deprivation Enhances Cocaine Conditioned Place Preference in an Orexin Receptor-Modulated Manner.

Drug addiction and withdrawal are characterized by sleep disruption, but the effects of sleep disruption on these states are not well characterized. Sleep deprivation (SD) immediately before the cocaine conditioning trials enhanced cocaine conditioned place preference (CPP) in a dose-dependent manner (3, 8 mg/kg but not 15 mg/kg) in mice. SD immediately before the postconditioning test also enhanced cocaine CPP preference in a dose-dependent manner (8 mg/kg, but not 3, 15 mg/kg). Exposure to orexin-receptor antagonism (1 mg/kg SB 334867, an orexin 1 receptor antagonist; OX1R) just before cocaine-conditioning trials or the postconditioning test attenuated SD-enhanced preference. This suggests a potential therapeutic role for the manipulation of the orexin system to mitigate drug seeking, especially in the context of sleep loss before drug exposure.

Sleeping Sickness Disrupts the Sleep-Regulating Adenosine System.

Patients with sleeping sickness, caused by the parasite Trypanosoma brucei, have disruptions in both sleep timing and sleep architecture. However, the underlying cause of these sleep disturbances is not well understood. Here, we assessed the sleep architecture of male mice infected with T. brucei and found that infected mice had drastically altered sleep patterns. Interestingly, T. brucei-infected mice also had a reduced homeostatic sleep response to sleep deprivation, a response modulated by the adenosine system. We found that infected mice had a reduced electrophysiological response to an adenosine receptor antagonist and increased adenosine receptor gene expression. Although the mechanism by which T. brucei infection causes these changes remains to be determined, our findings suggest that the symptoms of sleeping sickness may be because of alterations in homeostatic adenosine signaling.SIGNIFICANCE STATEMENT Sleeping sickness is a fatal disease that disrupts the circadian clock, causes disordered temperature regulation, and induces sleep disturbance. To examine the neurologic effects of infection in the absence of other symptoms, in this study, we used a mouse model of sleeping sickness in which the acute infection was treated but brain infection remained. Using this model, we evaluated the effects of the sleeping sickness parasite, Trypanosoma brucei, on sleep patterns in mice, under both normal and sleep-deprived conditions. Our findings suggest that signaling of adenosine, a neuromodulator involved in mediating homeostatic sleep drive, may be reduced in infected mice.

An essential role for MEF2C in the cortical response to loss of sleep in mice.

Neuronal activity and gene expression in response to the loss of sleep can provide a window into the enigma of sleep function. Sleep loss is associated with brain differential gene expression, an increase in pyramidal cell mEPSC frequency and amplitude, and a characteristic rebound and resolution of slow wave sleep-slow wave activity (SWS-SWA). However, the molecular mechanism(s) mediating the sleep-loss response are not well understood. We show that sleep-loss regulates MEF2C phosphorylation, a key mechanism regulating MEF2C transcriptional activity, and that MEF2C function in postnatal excitatory forebrain neurons is required for the biological events in response to sleep loss in C57BL/6J mice. These include altered gene expression, the increase and recovery of synaptic strength, and the rebound and resolution of SWS-SWA, which implicate MEF2C as an essential regulator of sleep function.

Loss of Arc attenuates the behavioral and molecular responses for sleep homeostasis in mice.

The activity-regulated cytoskeleton-associated protein (Arc) gene is a neural immediate early gene that is involved in synaptic downscaling and is robustly induced by prolonged wakefulness in rodent brains. Converging evidence has led to the hypothesis that wakefulness potentiates, and sleep reduces, synaptic strengthening. This suggests a potential role for Arc in these and other sleep-related processes. However, the role of Arc in sleep remains unknown. Here, we demonstrated that Arc is important for the induction of multiple behavioral and molecular responses associated with sleep homeostasis. Arc knockout (KO) mice displayed increased time spent in rapid eye movement (REM) sleep under baseline conditions and marked attenuation of sleep rebound to both 4 h of total sleep deprivation (SD) and selective REM deprivation. At the molecular level, the following homeostatic sleep responses to 4-h SD were all blunted in Arc KO mice: increase of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor GluA1 and its phosphorylation in synaptoneurosomes; induction of a subset of SD-response genes; and suppression of the GluA1 messenger RNA in the cortex. In wild-type brains, SD increased Arc protein expression in multiple subcellular locations, including the nucleus, cytoplasm, and synapse, which is reversed in part by recovery sleep. Arc is critical for these behavioral and multiple molecular responses to SD, thus providing a multifunctional role for Arc in the maintenance of sleep homeostasis, which may be attributed by the sleep/wake-associated changes in subcellular location of Arc.

Structure of cortical network activity across natural wake and sleep states in mice.

Cortical neurons fire intermittently and synchronously during non-rapid eye movement sleep (NREMS), in which active and silent periods are referred to as ON and OFF periods, respectively. Neuronal firing rates during ON periods (NREMS-ON-activity) are similar to those of wakefulness (W-activity), raising the possibility that NREMS-ON neuronal-activity is fragmented W-activity. To test this, we investigated the patterning and organization of cortical spike trains and of spike ensembles in neuronal networks using extracellular recordings in mice. Firing rates of neurons during NREMS-ON and W were similar, but showed enhanced bursting in NREMS with no apparent preference in occurrence, relative to the beginning or end of the on-state. Additionally, there was an overall increase in the randomness of occurrence of sequences comprised of multi-neuron ensembles in NREMS recorded from tetrodes. In association with increased burst firing, somatic calcium transients were increased in NREMS. The increased calcium transients associated with bursting during NREM may activate calcium-dependent, cell-signaling pathways for sleep related cellular processes.

MicroRNA targeting of the non-canonical planar cell polarity pathway in the developing neural tube.

MicroRNAs (miRNAs) provide context-dependent transcriptional regulation of genes comprising signalling networks throughout the developing organism including morphogenesis of the embryonic neural tube (NT). Using a high-sensitivity, high-coverage microarray analysis platform, miRNA expression in the murine embryonic NT during the critical stages of its formation was examined. Analysis of a number of differentially expressed (DE) miRNAs enabled identification of several gene targets associated with cellular processes essential for normal NT development. Using computational pathway analysis, interactive biologic networks and functional relationships connecting DE miRNAs with their targeted messenger RNAs (mRNAs) were identified. Potential mRNA targets and a key signal transduction pathway governing critical cellular processes indispensable for normal mammalian neurulation were also identified. RNA preparations were also used to hybridize both miRNA arrays and mRNA arrays allowing miRNA-mRNA target analysis using data of DE miRNAs and DE mRNAs - co-expressed in the same developing NT tissue samples. Identification of these miRNA targets provides key insight into the epigenetic regulation of NT development as well as into potential mechanistic underpinning of NT defects. SIGNIFICANCE OF THE STUDY: This study underscores the premise that microRNAs are potential coordinators of normal neural tube (NT) formation, via regulation of the crucial, planar cell polarity pathway. Any alteration in their expression during neurulation would result in abnormal NT development.

Enhanced cortical responsiveness during natural sleep in freely behaving mice.

Cortical networks exhibit large shifts in spontaneous dynamics depending on the vigilance state. Waking and rapid eye movement (REM) sleep are characterized by ongoing irregular activity of cortical neurons while during slow wave sleep (SWS) these neurons show synchronous alterations between silent (OFF) and active (ON) periods. The network dynamics underlying these phenomena are not fully understood. Additional information about the state of cortical networks can be obtained by evaluating evoked cortical responses during the sleep-wake cycle. We measured local field potentials (LFP) and multi-unit activity (MUA) in the cortex in response to repeated brief optogenetic stimulation of thalamocortical afferents. Both LFP and MUA responses were considerably increased in sleep compared to waking, with larger responses during SWS than during REM sleep. The strongly increased cortical response in SWS is discussed within the context of SWS-associated neuro-modulatory tone that may reduce feedforward inhibition. Responses to stimuli were larger during SWS-OFF periods than during SWS-ON periods. SWS responses showed clear daily fluctuation correlated to light-dark cycle, but no reaction to increased sleep need following sleep deprivation. Potential homeostatic synaptic plasticity was either absent or masked by large vigilance-state effects.