Sustained increase in annual transcranial Doppler screening rates in children with sickle cell disease: A quality improvement project.

INTRODUCTION: Individuals with sickle cell disease (SCD) at increased risk for stroke should undergo annual stroke risk assessment using transcranial Doppler (TCD) screening between the ages of 2 and 16. Though this screening can significantly reduce morbidity associated with SCD, screening rates at Boston Children's Hospital (and nationwide) remain below the recommended 100% screening adherence rates. METHODS: Three plan-do-study-act (PDSA) cycles were designed and implemented. The Specific, Measurable, Achievable, Relevant, and Time-Bound (SMART) aim of our quality improvement (QI) initiative was to sustainably increase the proportion of eligible patients receiving a TCD within 15 months of their last TCD to greater than 95%. An interrupted time series (ITS) analysis was performed, comparing TCD adherence rates from PDSA Cycle 1 to those from PDSA Cycles 2 and 3. RESULTS: Mean TCD adherence increased across all three PDSA cycles, from a baseline of 67% in the first cycle (January 2015 to September 2020) to 92% in the third cycle (May 2021 to March 2023). In the ITS analysis of TCD adherence rates, there was a significant difference in the final TCD adherence rate achieved compared to the rate predicted, with a total estimated increase in adherence of 17.9% being attributable to the interventions from PDSA Cycles 2 and 3. DISCUSSION: Although other QI initiatives had demonstrated ability to increase adherence to TCD screening for patients with SCD, this is the first QI project to collect data over such a prolonged period of time to demonstrate a sustained increase in screening rates throughout the intervention (an 8-year period).

Effects of a True Prophylactic Treatment on Hippocampal and Amygdala Synaptic Plasticity and Gene Expression in a Rodent Chronic Stress Model of Social Defeat.

Post-traumatic stress disorder (PTSD) is a complex stress-related disorder induced by exposure to traumatic stress that is characterized by symptoms of re-experiencing, avoidance, and hyper-arousal. While it is widely accepted that brain regions involved in emotional regulation and memory-e.g., the amygdala and hippocampus-are dysregulated in PTSD, the pathophysiology of the disorder is not well defined and therefore, pharmacological interventions are extremely limited. Because stress hormones norepinephrine and cortisol (corticosterone in rats) are heavily implicated in the disorder, we explored whether preemptively and systemically antagonizing ß-adrenergic and glucocorticoid receptors with propranolol and mifepristone are sufficient to mitigate pathological changes in synaptic plasticity, gene expression, and anxiety induced by a modified social defeat (SD) stress protocol. Young adult, male Sprague Dawley rats were initially pre-screened for anxiety. The rats were then exposed to SD and chronic light stress to induce anxiety-like symptoms. Drug-treated rats were administered propranolol and mifepristone injections prior to and continuing throughout SD stress. Using competitive ELISAs on plasma, field electrophysiology at CA1 of the ventral hippocampus (VH) and the basolateral amygdala (BLA), quantitative RT-PCR, and behavior assays, we demonstrate that our SD stress increased anxiety-like behavior, elevated long-term potentiation (LTP) in the VH and BLA, and altered the expression of mineralocorticoid, glucocorticoid, and glutamate receptors. These measures largely reverted to control levels with the administration of propranolol and mifepristone. Our findings indicate that SD stress increases LTP in the VH and BLA and that prophylactic treatment with propranolol and mifepristone may have the potential in mitigating these and other stress-induced effects.

Ethanol blocks a novel form of iLTD, but not iLTP of inhibitory inputs to VTA GABA neurons.

The ventral tegmental area (VTA) is an essential component of the mesocorticolimbic dopamine (DA) circuit that processes reward and motivated behaviors. The VTA contains DA neurons essential in this process, as well as GABAergic inhibitory cells that regulate DA cell activity. In response to drug exposure, synaptic connections of the VTA circuit can be rewired via synaptic plasticity-a phenomenon thought to be responsible for the pathology of drug dependence. While synaptic plasticity to VTA DA neurons as well as prefrontal cortex to nucleus accumbens GABA neurons are well studied, VTA GABA cell plasticity, specifically inhibitory inputs to VTA GABA neurons, is less understood. Therefore, we investigated the plasticity of these inhibitory inputs. Using whole cell electrophysiology in GAD67-GFP mice to identify GABA cells, we observed that these VTA GABA cells experience either inhibitory GABAergic long-term potentiation (iLTP) or inhibitory long-term depression (iLTD) in response to a 5 Hz stimulus. Paired pulse ratios, coefficient of variance, and failure rates suggest a presynaptic mechanism for both plasticity types, where iLTP is NMDA receptor-dependent and iLTD is GABAB receptor-dependent-this being the first report of iLTD onto VTA GABA cells. As illicit drug exposure can alter VTA plasticity, we employed chronic intermittent exposure (CIE) to ethanol (EtOH) vapor in male and female mice to examine its potential impact on VTA GABA input plasticity. Chronic EtOH vapor exposure produced measurable behavioral changes illustrating dependence and concomitantly prevented previously observed iLTD, which continued in air-exposed controls, illustrating the impact of EtOH on VTA neurocircuitry and suggesting physiologic mechanisms at play in alcohol use disorder and withdrawal states. Taken together, these novel findings of unique GABAergic synapses exhibiting either iLTP or iLTD within the mesolimbic circuit, and EtOH blockade specifically of iLTD, characterize inhibitory VTA plasticity as a malleable, experience-dependent system modified by EtOH.

A Novel Ketone-Supplemented Diet Improves Recognition Memory and Hippocampal Mitochondrial Efficiency in Healthy Adult Mice.

Mitochondrial dysfunction and cognitive impairment are common symptoms in many neurologic and psychiatric disorders, as well as nonpathological aging. Ketones have been suggested as therapeutic for their efficacy in epilepsy and other brain pathologies such as Alzheimer's disease and major depressive disorder. However, their effects on cognitive function in healthy individuals is less established. Here, we explored the mitochondrial and performative outcomes of a novel eight-week ketone-supplemented ketogenic (KETO) diet in healthy adult male and female mice. In a novel object recognition test, KETO mice spent more time with the novel, compared to familiar, object, indicating an improvement in recognition memory. High-resolution respirometry on permeabilized hippocampal tissue returned significant reductions in mitochondrial O2 consumption. No changes in ATP production were observed, yielding a significantly higher ATP:O2 ratio, a measure of mitochondrial efficiency. Together, these findings demonstrate the KETO diet improves hippocampal mitochondrial efficiency. They add to a growing body of evidence that suggests ketones and ketogenic diets are neuroprotective and metabolically and cognitively relevant, even in healthy adults. They also suggest that ketogenic lifestyle changes may be effective strategies for protecting against cognitive decline associated with aging and disease.

A Community-Based COVID-19 Vaccine Education Initiative.

Coronavirus disease 2019 (COVID-19) has had a disparate impact on Black and Latinx communities. Even before the COVID-19 pandemic, inaccessibility and distrust of the medical community rooted in historical oppression led to hesitancy about medical interventions. In Boston, COVID-19 vaccination rates of Black and Latinx adolescents lagged behind their white and Asian peers. In response, Boston Medical Center created community vaccine clinic sites across Suffolk County. Pediatric resident physicians subsequently partnered with Boston Medical Center to establish an accompanying education program entitled "Ask-a-Doc" to help improve health literacy and address vaccine hesitancy that focused on Black and Latinx adolescents. In partnership with multidisciplinary stakeholders, including Boston Public School leaders, Ask-a-Doc pediatric resident physicians staffed 46 community vaccine events in 15 zip codes. At these events, 1521 vaccine doses were administered, with most administered to Black and Latinx community members. As of January 1, 2022, 67% of 51 first-year pediatric resident physicians had participated. Ask-A-Doc is an example of a community-based intervention that directly targets health inequities and misinformation and demonstrates that pediatric resident physicians can meaningfully engage in community outreach with sufficient protected time, resources, and institutional support. The resulting connections may lead to greater trust and credibility within systematically oppressed communities.

Schooling amidst a pandemic in the United States: Parents' perceptions about reopening schools and anticipated challenges during COVID-19.

INTRODUCTION: During the COVID-19 pandemic, numerous states in the United States instituted measures to close schools or shift them to virtual platforms. Understanding parents' preferences for sending their children back to school, and their experiences with distance learning is critical for informing school reopening guidelines. This study characterizes parents' plans to return their children to school, and examines the challenges associated with school closures during the 2020-2021 academic year. METHODS: A national-level cross-sectional online survey was conducted in September 2020. Focusing on a subset of 510 respondents, who were parents of school-aged children, we examined variations in parents' plans for their children to return to school by their demographic and family characteristics, and challenges they anticipated during the school-year using multivariable logistic regressions. RESULTS: Fifty percent of respondents (n = 249) said that they would send their children back to school, 18% (n = 92) stated it would depend on what the district plans for school reopening, and 32% (n = 160) would not send their children back to school. No demographic characteristics were significantly associated with parents plans to not return their children to school. Overall, parents reported high-level of access to digital technology to support their child's learning needs (84%). However, those who reported challenges with distance learning due to a lack of childcare were less likely to not return their children to school (aOR = 0.33, 95% CI: 0.17, 0.64). Parents who reported requiring supervision after school had higher odds of having plans to not return their children to school (aOR = 1.97, 95% CI: 1.03, 3.79). Parents viewed COVID-19 vaccines and face-masks important for resuming in-person classes. DISCUSSION: About one-third of parents objected to their children returning to school despite facing challenges with distance learning. Besides access to vaccines and face-masks, our findings highlight the need to better equip parents to support remote learning, and childcare.

Chronic Δ9-tetrahydrocannabinol impact on plasticity, and differential activation requirement for CB1-dependent long-term depression in ventral tegmental area GABA neurons in adult versus young mice.

The ventral tegmental area (VTA) mediates incentive salience and reward prediction error through dopamine (DA) neurons that are regulated by local VTA GABA neurons. In young mice, VTA GABA cells exhibit a form of synaptic plasticity known as long-term depression (LTD) that is dependent on cannabinoid 1 (CB1) receptors preceded by metabotropic glutamate receptor 5 (mGluR5) signaling to induce endocannabinoid production. This LTD was eliminated following chronic (7-10 consecutive days) exposure to the marijuana derived cannabinoid Δ9 -tetrahydrocannabinol (THC). We now examine the mechanism behind THC-induced elimination of LTD in adolescents as well as plasticity induction ability in adult versus young male and female mice using whole-cell electrophysiology experiments of VTA GABA cells. Chronic THC injections in adolescents resulted in a loss of CB1 agonist-mediated depression, illustrating chronic THC likely desensitizes or removes synaptic CB1. We noted that seven days withdrawal from chronic THC restored LTD and CB1 agonist-induced depression, suggesting reversibility of THC-induced changes. Adult mice continue to express functional mGluR5 and CB1, but require a doubling of the synaptic stimulation compared to young mice to induce LTD, suggesting a quantitative difference in CB1-dependent plasticity between young and adult mice. One potential rationale for this difference is changes in AMPA and NMDA glutamate receptors. Indeed, AMPA/NMDA ratios were increased in in adults compared to young mice. Lastly, we performed quantitative reverse-transcription PCR and identified that CB1, DAGLα, and GluA1 levels increased following chronic THC exposure. Collectively, our data demonstrate the first age-dependent GABA neuron plasticity in the VTA, which could have implications for decreased THC dependence capacity in adults, as well as the mechanism behind chronic THC-induced synaptic alterations in young mice.

Health system and patient-level factors serving as facilitators and barriers to rheumatic heart disease care in Sudan.

BACKGROUND: Rheumatic heart disease (RHD) remains a leading cause of morbidity and mortality in Sub-Saharan Africa despite widely available preventive therapies such as prophylactic benzathine penicillin G (BPG). In this study, we sought to characterize facilitators and barriers to optimal RHD treatment with BPG in Sudan. METHODS: We conducted a mixed-methods study, collecting survey data from 397 patients who were enrolled in a national RHD registry between July and November 2017. The cross-sectional surveys included information on demographics, healthcare access, and patient perspectives on treatment barriers and facilitators. Factors associated with increased likelihood of RHD treatment adherence to prophylactic BPG were assessed by using adjusted logistic regression. These data were enhanced by focus group discussions with 20 participants, to further explore health system factors impacting RHD care. RESULTS: Our quantitative analysis revealed that only 32% of the study cohort reported optimal prophylaxis adherence. Younger age, reduced primary RHD healthcare facility wait time, perception of adequate health facility staffing, increased treatment costs, and high patient knowledge about RHD were significantly associated with increased odds of treatment adherence. Qualitative data revealed significant barriers to RHD treatment arising from health services factors at the health system level, including lack of access due to inadequate healthcare staffing, lack of faith in local healthcare systems, poor ancillary services, and patient lack of understanding of disease. Facilitators of RHD treatment included strong interpersonal support. CONCLUSIONS: Multiple patient and system-level barriers to RHD prophylaxis adherence were identified in Khartoum, Sudan. These included patient self-efficacy and participant perception of healthcare facility quality. Strengthening local health system infrastructure, while enhancing RHD patient education, may help to improve treatment adherence in this vulnerable population.

Neurology trial registrations on ClinicalTrials.gov between 2007 and 2018: A cross-sectional analysis of characteristics, early discontinuation, and results reporting.

BACKGROUND: Increasing neurological disease burden and advancing treatment options require clinical trials to expand the evidence base of clinical care. We aimed to characterize neurology clinical trials registered between October 2007 and April 2018 and identify features associated with early discontinuation and results reporting. METHODS: We compared 16,994 neurology (9.4%) and 163,714 non-neurology comparison trials registered to ClinicalTrials.gov. Trials therapeutic focus within neurology was assigned via combination programmatic and manual review. We performed descriptive analyses of trial characteristics, cox regression of early discontinuation, and multivariable logistic regression for results reporting within 3 years of completion. RESULTS: Most neurology trials were academic-funded (58.5%) followed by industry (31.9%) and US-government (9.6%). Neurology trials focused more on treatment than prevention compared to non-neurology studies. Of neurology trials, 11.3% discontinued early, and 32.2% of completed trials reported results by April 30, 2018. In multivariable analysis accounting for time-to-event, neurology trials were at lower risk of discontinuation than non-neurology trials (adjusted hazard 0.83, p < 0.0001). Both academic and government-funded trials had greater risk of discontinuation than industry (adjusted hazard 0.57 and 0.46, respectively). Among completed trials, government-funded studies (adjusted odds ratio 2.12, p < 0.0001) had highest odds of results reporting while academic trials reported less (adjusted odds ratio 0.51, p < 0.0001). CONCLUSIONS: Funding source is associated with trial characteristics and outcomes in neurology. Improvements in trial completion and timely dissemination of results remain urgent goals for the field.

Acute cocaine exposure occludes long-term depression in ventral tegmental area GABA neurons.

The ventral tegmental area (VTA) in the midbrain is essential in incentive salience of reward behavior. Drugs of abuse increase midbrain dopamine cell activity and/or dopamine levels, and can alter endogenous VTA glutamate plasticity, leading to addiction or dependence. VTA dopamine cells are regulated by local inhibitory GABA cells, which exhibit a form of pre-synaptic cannabinoid receptor 1-dependent long-term depression of their glutamatergic inputs. Our current aim was to determine cocaine's influence on VTA GABA cell glutamate plasticity and circuity. Using whole cell voltage-clamp electrophysiology in VTA slices of GAD67-GFP knock-in mice, we recorded excitatory inputs on VTA GABA cells. Acute and chronic injections of cocaine were sufficient to occlude long-term depression. The plasticity could be reversed to the naïve state however, as long-term depression was again observed following a 7-day abstinence from acute cocaine exposure. Furthermore, chronic cocaine decreased AMPA/NMDA ratios at glutamate synapses onto VTA GABA cells, compared to vehicle injection controls, the opposite change noted in dopamine cells. Collectively, our data suggest the cellular mechanism of cocaine-mediated synaptic modification that may result in dependence/withdrawal could involve changes in glutamate input to VTA GABA circuitry in addition to VTA dopamine cells. Therefore VTA GABA cells may also play a role, possibly in a synergistic manner with the dopamine circuit, in cocaine-induced changes to the VTA reward pathway than previously known.

Expression of type I mGluRs predicts plasticity in the hippocampal stratum radiatum interneurons.

Changes in synaptic strength between hippocampal CA1 pyramidal cell synapses are partly responsible for memory acquisition. This plasticity is modulated by feedforward inhibitory interneurons in the stratum radiatum. While radiatum interneurons experience either long-term depression (LTD), short-term depression (STD), or lack plasticity, it is unclear whether plasticity correlates to specific interneuron subtypes. Using whole-cell electrophysiology and real-time quantitative PCR, we characterized the plasticity expressed by different interneuron subtypes. We first analyzed calcium binding proteins and cholecystokinin mRNA expression patterns to determine cell subtype. We then assessed endocannabinoid (eCB) biosynthetic enzyme mRNA expression, including diacylglycerol lipase α, N-acyl-phosphatidylethanolamine phospholipase D, and 12-lipoxygenase, and metabotropic glutamate receptors that often mediate plasticity. Neurons exhibiting LTD tended to co-express mRNA for at least one eCB biosynthetic enzyme and the metabotropic glutamate receptor 5 (mGluR5). Conversely, mGluR5 was not expressed by neurons exhibiting STD or no plasticity. Neurons that exhibited STD tended to express mRNA for at least one eCB biosynthetic enzyme and mGluR1, but not mGluR5. This suggests that plasticity of stratum radiatum interneurons could be predicted based on type I mGluR expression.

Hippocampal Stratum Oriens Somatostatin-Positive Cells Undergo CB1-Dependent Long-Term Potentiation and Express Endocannabinoid Biosynthetic Enzymes.

The hippocampus is thought to encode information by altering synaptic strength via synaptic plasticity. Some forms of synaptic plasticity are induced by lipid-based endocannabinoid signaling molecules that act on cannabinoid receptors (CB1). Endocannabinoids modulate synaptic plasticity of hippocampal pyramidal cells and stratum radiatum interneurons; however, the role of endocannabinoids in mediating synaptic plasticity of stratum oriens interneurons is unclear. These feedback inhibitory interneurons exhibit presynaptic long-term potentiation (LTP), but the exact mechanism is not entirely understood. We examined whether oriens interneurons produce endocannabinoids, and whether endocannabinoids are involved in presynaptic LTP. Using patch-clamp electrodes to extract single cells, we analyzed the expression of endocannabinoid biosynthetic enzyme mRNA by reverse transcription and then real-time PCR (RT-PCR). The cellular expression of calcium-binding proteins and neuropeptides were used to identify interneuron subtype. RT-PCR results demonstrate that stratum oriens interneurons express mRNA for both endocannabinoid biosynthetic enzymes and the type I metabotropic glutamate receptors (mGluRs), necessary for endocannabinoid production. Immunohistochemical staining further confirmed the presence of diacylglycerol lipase alpha, an endocannabinoid-synthesizing enzyme, in oriens interneurons. To test the role of endocannabinoids in synaptic plasticity, we performed whole-cell experiments using high-frequency stimulation to induce long-term potentiation in somatostatin-positive cells. This plasticity was blocked by AM-251, demonstrating CB1-dependence. In addition, in the presence of a fatty acid amide hydrolase inhibitor (URB597; 1 µM) and MAG lipase inhibitor (JZL184; 1 µM) that increase endogenous anandamide and 2-arachidonyl glycerol, respectively, excitatory current responses were potentiated. URB597-induced potentiation was blocked by CB1 antagonist AM-251 (2 µM). Collectively, this suggests somatostatin-positive oriens interneuron LTP is CB1-dependent.

Running exercise mitigates the negative consequences of chronic stress on dorsal hippocampal long-term potentiation in male mice.

In the hippocampus, learning and memory are likely mediated by synaptic plasticity, known as long-term potentiation (LTP). While chronic intermittent stress is negatively correlated, and exercise positively correlated to LTP induction, we examined whether exercise could mitigate the negative consequences of stress on LTP when co-occurring with stress. Mice were divided into four groups: sedentary no stress, exercise no stress, exercise with stress, and sedentary with stress. Field electrophysiology performed on brain slices confirmed that stress alone significantly reduced dorsal CA1 hippocampal LTP and exercise alone increased LTP compared to controls. Exercise with stress mice exhibited LTP that was significantly greater than mice undergoing stress alone but were not different from sedentary no stress mice. An ELISA illustrated increased corticosterone in stressed mice compared to no stress mice. In addition, a radial arm maze was used to examine behavioral changes in memory during 6 weeks of stress and/or exercise. Exercised mice groups made fewer errors in week 2. RT-qPCR was used to examine the mRNA expression of components in the stress and exercise pathways in the four groups. Significant changes in the expression of the following targets were detected: BDNF, TrkB, glucocorticoid, mineralocorticoid, and dopamine 5 receptors. Collectively, exercise can mitigate some of the negative impact stress has on hippocampal function when both occur concurrently.

α6 subunit-containing nicotinic receptors mediate low-dose ethanol effects on ventral tegmental area neurons and ethanol reward.

Dopamine (DA) neuron excitability is regulated by inhibitory GABAergic synaptic transmission and modulated by nicotinic acetylcholine receptors (nAChRs). The aim of this study was to evaluate the role of α6 subunit-containing nAChRs (α6*-nAChRs) in acute ethanol effects on ventral tegmental area (VTA) GABA and DA neurons. α6*-nAChRs were visualized on GABA terminals on VTA GABA neurons, and α6*-nAChR transcripts were expressed in most DA neurons, but only a minority of VTA GABA neurons from GAD67 GFP mice. Low concentrations of ethanol (1-10 mM) enhanced GABAA receptor (GABAA R)-mediated spontaneous and evoked inhibition with blockade by selective α6*-nAChR antagonist α-conotoxins (α-Ctxs) and lowered sensitivity in α6 knock-out (KO) mice. Ethanol suppression of VTA GABA neuron firing rate in wild-type mice in vivo was significantly reduced in α6 KO mice. Ethanol (5-100 mM) had no effect on optically evoked GABAA R-mediated inhibition of DA neurons, and ethanol enhancement of VTA DA neuron firing rate at high concentrations was not affected by α-Ctxs. Ethanol conditioned place preference was reduced in α6 KO mice compared with wild-type controls. Taken together, these studies indicate that relatively low concentrations of ethanol act through α6*-nAChRs on GABA terminals to enhance GABA release onto VTA GABA neurons, in turn to reduce GABA neuron firing, which may lead to VTA DA neuron disinhibition, suggesting a possible mechanism of action of alcohol and nicotine co-abuse.

CB1-Dependent Long-Term Depression in Ventral Tegmental Area GABA Neurons: A Novel Target for Marijuana.

The VTA is necessary for reward behavior with dopamine cells critically involved in reward signaling. Dopamine cells in turn are innervated and regulated by neighboring inhibitory GABA cells. Using whole-cell electrophysiology in juvenile-adolescent GAD67-GFP male mice, we examined excitatory plasticity in fluorescent VTA GABA cells. A novel CB1-dependent LTD was induced in GABA cells that was dependent on metabotropic glutamate receptor 5, and cannabinoid receptor 1 (CB1). LTD was absent in CB1 knock-out mice but preserved in heterozygous littermates. Bath applied Δ9-tetrahydrocannabinol depressed GABA cell activity, therefore downstream dopamine cells will be disinhibited; and thus, this could potentially result in increased reward. Chronic injections of Δ9-tetrahydrocannabinol occluded LTD compared with vehicle injections; however, a single exposure was insufficient to do so. As synaptic modifications by drugs of abuse are often tied to addiction, these data suggest a possible mechanism for the addictive effects of Δ9-tetrahydrocannabinol in juvenile-adolescents, by potentially altering reward behavioral outcomes.SIGNIFICANCE STATEMENT The present study identifies a novel form of glutamatergic synaptic plasticity in VTA GABA neurons, a currently understudied cell type that is critical for the brain's reward circuit, and how Δ9-tetrahydrocannabinol occludes this plasticity. This study specifically addresses a potential unifying mechanism whereby marijuana could exert rewarding and addictive/withdrawal effects. Marijuana use and legalization are a pressing issue for many states in the United States. Although marijuana is the most commonly abused illicit drug, the implications of legalized, widespread, or continued usage are speculative. This study in juvenile-adolescent aged mice identifies a novel form of synaptic plasticity in VTA GABA cells, and the synaptic remodeling that can occur after Δ9-tetrahydrocannabinol use.