Mechanisms of synapse-to-nucleus calcium signalling in striatal neurons and impairments in Huntington's disease.

Huntington's disease (HD) is a monogenic disorder with autosomal dominant inheritance. In HD patients, neurons in the striatum and cortex degenerate, leading to motor, psychiatric and cognitive disorders. Dysregulated synaptic function and calcium handling are common in many neurodegenerative diseases, including HD. N-methyl-D-aspartate (NMDA) receptor function is enhanced in HD at extrasynaptic sites, altering the balance of calcium-dependent neuronal survival versus death signalling pathways. Endoplasmic reticulum (ER) calcium handling is also abnormal in HD. The ER, which is continuous with the nuclear envelope, is purportedly involved in nuclear calcium signalling; based on this, we hypothesised that nuclear calcium signalling is altered in HD. We explored this hypothesis with calcium imaging techniques, including simultaneous epifluorescent imaging of cytosolic and nuclear calcium using jRCaMP1b and GCaMP3 sensors, respectively, in striatal spiny projection neurons in cortical-striatal co-cultures from the YAC128 mouse model of HD. Our data show contributions from a variety of calcium channels to nuclear calcium signalling. NMDA receptors (NMDARs) play an essential role in initiating action potential-dependent calcium signalling to the nucleus, and ryanodine receptors (RyR) contribute to both cytosolic and nuclear calcium signals. Unlike previous reports in glutamatergic hippocampal and cortical neurons, we found that in GABAergic striatal neurons, L-type voltage-gated calcium channels (CaV) contribute to cytosolic, but not nuclear calcium signalling. Calcium imaging also suggests impairments in nuclear calcium signalling in HD striatal neurons, where spontaneous action potential-dependent calcium transients in the nucleus were smaller in YAC128 striatal neurons compared to those of wild-type (WT). Our results elucidate mechanisms involved in action potential-dependent nuclear calcium signalling in GABAergic striatal neurons, and have revealed a clear deficit in this signalling in HD.

Deep behavioural phenotyping of the Q175 Huntington disease mouse model: effects of age, sex, and weight.

BACKGROUND: Huntington disease (HD) is a neurodegenerative disorder with complex motor and behavioural manifestations. The Q175 knock-in mouse model of HD has gained recent popularity as a genetically accurate model of the human disease. However, behavioural phenotypes are often subtle and progress slowly in this model. Here, we have implemented machine-learning algorithms to investigate behaviour in the Q175 model and compare differences between sexes and disease stages. We explore distinct behavioural patterns and motor functions in open field, rotarod, water T-maze, and home cage lever-pulling tasks. RESULTS: In the open field, we observed habituation deficits in two versions of the Q175 model (zQ175dn and Q175FDN, on two different background strains), and using B-SOiD, an advanced machine learning approach, we found altered performance of rearing in male manifest zQ175dn mice. Notably, we found that weight had a considerable effect on performance of accelerating rotarod and water T-maze tasks and controlled for this by normalizing for weight. Manifest zQ175dn mice displayed a deficit in accelerating rotarod (after weight normalization), as well as changes to paw kinematics specific to males. Our water T-maze experiments revealed response learning deficits in manifest zQ175dn mice and reversal learning deficits in premanifest male zQ175dn mice; further analysis using PyMouseTracks software allowed us to characterize new behavioural features in this task, including time at decision point and number of accelerations. In a home cage-based lever-pulling assessment, we found significant learning deficits in male manifest zQ175dn mice. A subset of mice also underwent electrophysiology slice experiments, revealing a reduced spontaneous excitatory event frequency in male manifest zQ175dn mice. CONCLUSIONS: Our study uncovered several behavioural changes in Q175 mice that differed by sex, age, and strain. Our results highlight the impact of weight and experimental protocol on behavioural results, and the utility of machine learning tools to examine behaviour in more detailed ways than was previously possible. Specifically, this work provides the field with an updated overview of behavioural impairments in this model of HD, as well as novel techniques for dissecting behaviour in the open field, accelerating rotarod, and T-maze tasks.

Activin A targets extrasynaptic NMDA receptors to ameliorate neuronal and behavioral deficits in a mouse model of Huntington disease.

Cortical-striatal synaptic dysfunction, including enhanced toxic signaling by extrasynaptic N-methyl-d-aspartate receptors (eNMDARs), precedes neurodegeneration in Huntington disease (HD). A previous study showed Activin A, whose transcription is upregulated by calcium influx via synaptic NMDARs, suppresses eNMDAR signaling. Therefore, we examined the role of Activin A in the YAC128 HD mouse model, comparing it to wild-type controls. We found decreased Activin A secretion in YAC128 cortical-striatal co-cultures, while Activin A overexpression in this model rescued altered eNMDAR expression. Striatal overexpression of Activin A in vivo improved motor learning on the rotarod task, and normalized striatal neuronal eNMDAR-mediated currents, membrane capacitance and spontaneous excitatory postsynaptic current frequency in the YAC128 mice. These results support the therapeutic potential of Activin A signaling and targeting eNMDARs to restore striatal neuronal health and ameliorate behavioral deficits in HD.

Dimensions of beliefs without strong supporting evidence and reasons for holding them.

Beliefs without strong supporting evidence (BWSSE) are commonplace, such as religious beliefs and conspiracy theories. The goals of the current study were to identify dimensions of BWSSE in the general public and study how reasons for holding each dimension depend on the strength of the belief. Participants completed a BWSSE questionnaire online, and principal component analysis suggested that the questionnaire captured 6 dimensions of beliefs that range in strength: New Age Spiritual, Traditional Spiritual, Nonconformist, Science, Mythical, and Conspiracy Theory. Mixed-model analyses of variance showed that while high-strength believers in both New Age and Traditional Spiritual shifted their reasons-for-belief away from 'just believe' and towards personal experience, only Traditional Spiritual shifted away from 'just believe' to culture. In contrast, for Conspiracy Theory and Mythical, the dominant reason for belief was media, but for Conspiracy Theory only, there was a shift from media to education/personal research for high-strength believers. This demonstrates that although spiritual beliefs are strengthened by personal experience, conspiracy theory beliefs are strengthened by information gathering. Understanding the source of an existing belief is important for debiasing attempts to move people towards beliefs with strong supporting evidence, including greater acceptance of evidence provided by experts, a likely requirement for negotiating global humanitarian emergencies in the not-so-distant future. Statement of Relevance. Beliefs without strong supporting evidence (BWSSE) have been gaining attention in mainstream society; particularly, the sources of information that may contribute to their formation and resistance to correction. Understanding the source of an existing belief is important for debiasing attempts to move people towards beliefs with strong supporting evidence, including greater acceptance of evidence provided by experts, a likely requirement for negotiating global humanitarian emergencies in the not-so-distant future.

Sodium-Glucose Cotransporter 2 Inhibitors Among Heart Failure With Mildly Reduced and Preserved Ejection Fraction.

OBJECTIVE: Results from large placebo-controlled randomized trials in patients with heart failure with mid-range ejection fraction (HFmrEF) and HF with preserved EF (HFpEF) have become available recently. This article discusses results of these clinical trials. DATA SOURCES: Peer-reviewed articles were identified from MEDLINE (1966 to December 31, 2022) using search terms dapagliflozin, empagliflozin, SGLT-2Is, HFmrEF, and HFpEF. STUDY SELECTION AND DATA EXTRACTION: Eight completed, pertinent clinical trials were included. DATA SYNTHESIS: EMPEROR-Preserved, and DELIVER demonstrated that empagliflozin and dapagliflozin reduce CV death and heart failure hospitalization (HHF) in patients with HFmrEF and HFpEF, with/without diabetes when added to a standard heart failure (HF) regimen. The benefit is primarily due to reduction in HHF. Additional data from post hoc analyses of trials of dapagliflozin, ertugliflozin, and sotagliflozin suggest that these benefits may be a class effect. Benefits appear greatest in patients with left ventricular ejection fraction 41% up to about 65%. RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE: While many pharmacologic treatments have been proven to reduce mortality and improve cardiovascular (CV) outcomes in people with HFmrEF and HF with reduced EF (HFrEF), there are few therapy which improve CV outcome in people with HFpEF. SGLT-2I become one of the first class of pharmacologic agent that can be used to reduce HHF and CV mortality. CONCLUSION: Studies showed that empagliflozin and dapagliflozin reduce the combined risk of CV death or HHF in patients with HFmrEF and HFpEF when added to a standard HF regimen. Given that benefit has now been demonstrated across the spectrum of HF, SGLT-2Is should be considered one of the standard HF pharmacotherapy.

Early Changes in Striatal Activity and Motor Kinematics in a Huntington's Disease Mouse Model.

BACKGROUND: Huntington's disease is a progressive neurodegenerative disorder with no disease-modifying treatments. Patients experience motor, cognitive, and psychiatric disturbances, and the dorsal striatum is the main target of neurodegeneration. Mouse models of Huntington's disease show altered striatal synaptic signaling in vitro, but how these changes relate to behavioral deficits in vivo is unclear. OBJECTIVES: We aimed to investigate how striatal activity correlates with behavior in vivo during motor learning and spontaneous behavior in a Huntington's disease mouse model at two disease stages. METHODS: We used fiber photometry to record jGCaMP7f fluorescence, a read-out of neuronal activity, in the dorsal striatum of YAC128 (yeast artificial chromosome-128CAG) mice during accelerating rotarod and open-field behavior. RESULTS: Mice showed increased striatal activity on the rotarod, which diminished by late stages of learning, leading to an inverse correlation between latency to fall and striatal activity. The 2- to 3-month-old YAC128 mice did not show a deficit in latency to fall, but displayed significant differences in paw kinematics, including increased paw slip frequency and variability in paw height. These mice exhibited a weaker correlation between latency to fall and striatal activity and aberrant striatal activity during paw slips. At 6 to 7 months, the YAC128 mice showed significantly reduced latency to fall, impaired paw kinematics, and increased striatal activity while on the rotarod. In the open field, the YAC128 mice showed elevated neuronal activity at rest. CONCLUSIONS: We uncovered impaired motor coordination at a stage thought to be premotor manifest in YAC128 mice and aberrant striatal activity during the accelerating rotarod and open-field exploration. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Review of Lasers and Energy-Based Devices for Skin Rejuvenation and Scar Treatment With Histologic Correlations.

BACKGROUND: Lasers and energy-based devices (EBD) are popular treatments for skin rejuvenation and resurfacing. Achieving desired outcomes and avoiding complications require understanding the effects of these devices at a histologic level. Currently, no comprehensive review summarizing the histologic effects of laser and energy-based treatments exists. OBJECTIVE: To describe how lasers and EBD alter skin histology and improve the overall understanding of these devices. MATERIALS AND METHODS: A PubMed search was conducted for studies with histologic analysis of fractional picosecond laser, fractional radiofrequency microneedling, nonablative lasers, and ablative lasers. RESULTS: Fractional picosecond lasers induce intraepidermal and/or dermal vacuoles from laser-induced optical breakdown. Fractional radiofrequency microneedling delivers thermal energy to the dermis while sparing the epidermis, making it safer for patients with darker skin phototypes. Fractional nonablative lasers induce conical zones of coagulation of the epidermis and upper dermis. Ablative lasers vaporize the stratum corneum down to the dermis. Traditional ablative lasers cause diffuse vaporization while fractional ablative lasers generate columns of tissue ablation. CONCLUSION: Lasers and EBD are effective for skin resurfacing and rejuvenation and have different mechanisms with disparate targets in the skin. Safe and effective use of devices requires understanding the histologic laser-tissue interaction.

Focused Updates: SGLT2 Inhibitors in Patients With Heart Failure and/or Chronic Kidney Disease.

Sodium-glucose cotransporter (SGLT2) inhibitors have demonstrated cardiovascular (CV) benefits in large-scale clinical trials of people who have type 2 diabetes and either established CV disease or multiple CV risk factors. These studies also indicated early signals in benefiting heart failure (HF) patients and those with chronic kidney diseases. This article reviews recent and future clinical studies that focus on evaluation of the use of SGLT2 inhibitors in HF management and renal protection.

Electrolyte-Free Spectroscopy and Imaging of Graphite Intercalation.

Engineering electrode materials for optoelectronic and energy storage applications requires a fundamental understanding of intercalation using spatially-resolved techniques. However, spectroscopic methods can have limited spatial resolution and low intensity since the signal passes through electrolyte. Here, a device geometry is presented in which the electrolyte is laterally separated from the area probed spectroscopically, so that the signal does not pass through the electrolyte. This geometry enables us to visualize ion transport with optical microscopy and monitor charge transfer with Raman and visible reflectance spectroscopies. In addition, vibrational changes are probed in the mid-IR, a region previously difficult to access due to electrolyte absorption. This geometry will allow many layered electrodes to be probed in situ using time- and spatially-resolved techniques, including photon and electron spectroscopies.

Cardiovascular Pharmacology in the Time of COVID-19: A Focus on Angiotensin-Converting Enzyme 2.

Coronavirus disease-2019 (COVID-19) has emerged as a pandemic affecting millions of adults. Severe acute respiratory syndrome coronavirus-2019 (SARS-CoV-2), the causative virus of COVID-19, infects host cells through angiotensin-converting enzyme 2 (ACE2). Preclinical models suggest that ACE2 upregulation confers protective effects in acute lung injury. In addition, renin-angiotensin aldosterone system inhibitors reduce adverse atherosclerotic cardiovascular disease, heart failure, and chronic kidney disease outcomes, but may increase ACE2 levels. We review current knowledge of the role of ACE2 in cardiovascular physiology and SARS-CoV-2 virology, as well as clinical data to inform the management of patients with or at risk for COVID-19 who require renin-angiotensin-aldosterone system inhibitor therapy.

Factors Affecting Depth of Penetration in Microneedling- and Laser-Assisted Drug Delivery: The Importance of Timing of Topical Application.

BACKGROUND: Microneedling- and laser-assisted drug delivery are emerging techniques used to treat various conditions. However, key parameters affecting drug penetration remain unknown. OBJECTIVE: This study aims to investigate the importance of timing of topical application, needle length, and device type for drug delivery. MATERIALS AND METHODS: Skin harvested from cosmetic surgeries was treated with black ink applied before or after treatment with a microneedling pen (MP), roller, or fractional ablative CO2 laser, and incubated for different time intervals. Ink penetration was additionally tested using different needle lengths. Sandwich estimator was used for statistical analysis. RESULTS: Ink applied before MP penetrated deeper compared to ink applied afterward at 1 and 3 hours, and roller microneedling in both the ink-before and -after scenarios at 1, 3, and 6 hours (p < .05). Microneedling demonstrated lateral extension of ink beyond microchannels with increased ink penetration over time. CO2 laser demonstrated ink localization within microthermal zones without time-dependent increases in depth after 30 minutes. Ink penetration increases by 0.06 mm per 1 mm increase in needle length. CONCLUSION: Ink applied before MP results in the deepest penetration of ink. Microneedling offers unique advantages in transdermal delivery as its channels exhibit increasing penetration over time and lateral extension of product.

Comparison of Positive Inotropic Agents in the Management of Acute Decompensated Heart Failure.

Current guidelines recommend the consideration of positive inotropes in patients with acute decompensated heart failure (ADHF) who have low cardiac index and evidence of systemic hypoperfusion or congestion. However, there is no evidence detailing the first line agent for the management of ADHF. The purpose of this study was to compare the safety and efficacy of dobutamine to milrinone for the treatment of ADHF. This was a single-center, retrospective study at a tertiary academic medical center, approved by Partner's Health Care Institutional Review Board. Patients included in this study were those admitted with ADHF who received dobutamine or milrinone from June 2015 to July 2017. A total of 95 dobutamine and 40 milrinone patients were included in the analysis. Median hospital length of stay was 12 days in the dobutamine group versus 10 days in the milrinone group (P = 0.34). Rehospitalization within 30 days occurred in 29.5% of patients in the dobutamine group versus 17.5% of patients in the milrinone group (P = 0.15). Median intensive care unit length of stay was 4.5 days in the dobutamine group versus 10 days in the milrinone group (P < 0.01). All other minor end points including all-cause mortality, progression to renal failure within 72 hours, rehospitalization in 90 days, and urine output within 72 hours of therapy were not found to be statistically significant. In addition, a post hoc analysis compared major and minor outcomes between milrinone and dobutamine using linear and logistic regression with adjustment for baseline characteristics. There were not any statistically significant findings in the post hoc analysis. Overall, there were no statistically significant differences in outcomes between the 2 groups other than longer intensive care unit length of stay in the milrinone group.

Botulinum Toxin Injections for Leg Contouring in East Asians.

BACKGROUND: A common aesthetic concern among East Asian women is enlarged calves. Although surgical resection has been a traditional treatment option, botulinum toxin injections into the gastrocnemius muscle are an emerging, noninvasive alternative. OBJECTIVE: To perform a literature review on botulinum toxin injections for leg contouring. MATERIALS AND METHODS: A literature review was conducted using PubMed, Web of Science, Embase, and Cochrane's CENTRAL database to identify articles relating to combinations of the terms botulinum toxin, gastrocnemius, calves, and leg contouring. RESULTS: Based on the limited publications to date, the authors prepared a review on how to treat an enlarged calf with botulinum toxin including injection techniques, anticipated efficacy, outcome monitoring, and potential side effects. CONCLUSION: Botulinum toxin injections for calf reduction are an emerging, noninvasive treatment option. Studies to date suggest that it is an efficacious method with few immediate side effects. Future areas for investigation include defining the criteria for calf hypertrophy, minimum effective dosage of botulinum toxin, and the potential long-term effects of injections.

Characteristics of keratinocyte carcinomas in Hispanics compared to non-Hispanic whites: A retrospective 5-year study.

BACKGROUND: Hispanics are one of the fastest growing populations in the United States. Few studies have characterized the patterns of keratinocyte carcinoma presentation in Hispanics. OBJECTIVE: The study aimed to compare the clinical and histologic characteristics of keratinocyte carcinomas in Hispanics and non-Hispanic whites. MATERIALS AND METHODS: A five-year retrospective chart review was conducted at a single academic center to identify all histologically-confirmed cases of keratinocyte carcinomas. Tumor characteristics were then compared between Hispanics and non-Hispanic whites. RESULTS: A total of 197 tumors were identified of which 76% occurred in non-Hispanic whites and 24% in Hispanics. Tumor diameter was not larger and histologic subtype was not more aggressive in Hispanics compared to non-Hispanic whites. Age of diagnosis of basal cell carcinoma was younger among Hispanics compared to non-Hispanic whites (P < .05). CONCLUSION: Hispanics were not more likely to present with more high-risk keratinocyte carcinomas compared to non-Hispanic whites in terms of tumor diameter, differentiation and subtype.

Botulinum Toxin Injections for Masseter Reduction in East Asians.

BACKGROUND: Cultural ideals for a slimmer face have led to an upsurge in interest in facial contouring among East Asians. Although surgical resection has traditionally been the main treatment option, botulinum toxin injection is becoming a popular, noninvasive alternative. OBJECTIVE: To describe the use of botulinum toxin injection for masseter reduction in East Asians. METHODS: An electronic search of the PubMed database was performed for studies published from 2000 to 2017 that meet the word combination of botulinum toxin, masseter, hypertrophy, and/or lower face contouring. Only the studies conducted in East Asian countries were analyzed in this review, exception of one study from Thailand. RESULTS: A total of 12 publications were identified. Each study was reviewed to extract relevant information on patient selection, injection techniques, efficacy, dosage, frequency, and main side effects of treating masseters with botulinum toxin. CONCLUSION: Botulinum toxin injection for masseter reduction in East Asians is efficacious and generally considered safe with no significant side effects. Future areas for investigation include defining the criteria for benign masseteric hypertrophy, minimum effective dosage of botulinum toxin, and the potential long-term effects of the injection.

Effect of stimuli on sun protective habits: A randomized double-blind controlled study.

BACKGROUND: Visual imagery has been shown to improve adherence to health messages but has scarcely been investigated in sun protection campaigns. OBJECTIVE: To determine the effectiveness of pictorial- and textual-based sun protective messages in a largely Hispanic population. METHODS: One hundred and forty-five participants received standard of care (SOC) as defined as sun protective counseling and were then randomized to receive either (a) images of sun damage, (b) a textual pamphlet about sun damage, or (c) no further messages. Analysis-of-variance tests for repeated measures were used to estimate the effects of the different stimuli on participants' knowledge and intention to sun protect. RESULTS: All stimulus groups demonstrated an improvement in perceived effectiveness of sun protective habits (p < 0.05). However, pictorial and textual stimuli were both more effective than SOC in improving intentions to sun protect (p < 0.05), but there was no differential effect between the two. CONCLUSIONS: Both pictorial and textual stimuli were more effective than SOC in improving intentions to sun protect, but there was no differential effect between the two.

Appearance-based vs health-based sun protective messages: A randomized, double-blind controlled study.

BACKGROUND: Appearance-based messages have shown promise in improving sun protection habits among Caucasians but have scarcely been investigated in Hispanic populations. OBJECTIVE: To compare the effectiveness of appearance-based vs health-based messages in an ethnic patient population, where hyperpigmentation disorders are prevalent and often cosmetically concerning. METHODS: One hundred thirty-seven patients were randomized to receive images of (a) skin cancer, (b) hyperpigmentation, or (c) wrinkles. Analysis of variance tests for repeated measures were used to estimate the effects of the different stimuli on participants' knowledge and intention to sun protect. RESULTS: Appearance-based interventions were more effective in improving intentions to sun protect among both Hispanics and non-Hispanic Whites (P < 0.05). They were furthermore more effective among younger patient populations (≤40 years old) and patients who thought that a tanned appearance is attractive (P < 0.05). CONCLUSIONS: Appearance-based photos of sun damage were more effective than health-based messages among Hispanics, younger patient populations, and those who find tanned appearances to be attractive.

Managing Diabetes and Preventing Heart Disease: Have We Found a Safe and Effective Agent?

OBJECTIVE: While improving glycemic control with antihyperglycemics has been demonstrated to reduce microvascular complications, the benefits of reduction in cardiovascular diseases (CVDs) have not been demonstrated with older agents. This article reviews current evidence of the CV outcomes of newer antihyperglycemics approved since 2008. DATA SOURCES: Peer-reviewed articles were identified from MEDLINE (1966 to October 31, 2018) using search terms exenatide, liraglutide, lixisenatide, dulaglutide, semaglutide, alogliptin, linagliptin, saxagliptin, sitagliptin, canagliflozin, dapagliflozin, empagliflozin, mortality, myocardial infarction (MI), heart failure (HF), and stroke. STUDY SELECTION AND DATA EXTRACTION: A total of 12 pertinent double-blinded randomized controlled trials were included. DATA SYNTHESIS: Liraglutide, empagliflozin, and canagliflozin have been shown in patients with CV diseases and high risk of developing CV disease to be superior to placebo in improving CV outcomes. Saxagliptin and alogliptin have both been demonstrated to increase HF hospitalization, whereas sitagliptin has not. Relevance to Patient Care and Clinical Practice: In contrast to older-generation antihyperglycemics, selected new antihyperglycemic agents have been shown to be superior to placebo in improving CV outcomes. Clinicians may now be able to provide high-risk patients agents that not only help in providing glycemic control, but also prevent both macrovascular and microvascular complications. CONCLUSION: Liraglutide, empagliflozin, and canagliflozin have been shown to be superior to placebo in improving CV outcomes. However, there are differences among agents in terms of HF and peripheral arterial disease outcomes. Future studies should focus on evaluating other clinical CV outcomes in patients without existing CVD and perhaps single drug regimens for diabetes.