Spontaneous Coronary Artery Dissection in a Male Patient With Fibromuscular Dysplasia.

A male patient presented with cardiac arrest attributed to anterior ST-segment elevation myocardial infarction from type 1 spontaneous coronary artery dissection. Subsequent imaging confirmed fibromuscular dysplasia in noncoronary arterial segments. The patient was started on guideline-directed medical therapy and referred to cardiac rehabilitation, showing substantial improvements in clinical status. With greater awareness and advancements in imaging, spontaneous coronary artery dissection has been more frequently recognized, and although as many as 81% to 92% of all cases occur in female patients, it can be seen among men, as well. Adjunctive imaging for arteriopathies may help establish the diagnosis for equivocal causes of acute coronary syndrome in women and men.

Deletion of the auxiliary α2δ1 voltage sensitive calcium channel subunit in osteocytes and late-stage osteoblasts impairs femur strength and load-induced bone formation in male mice.

Osteocytes sense and respond to mechanical force by controlling the activity of other bone cells. However, the mechanisms by which osteocytes sense mechanical input and transmit biological signals remain unclear. Voltage-sensitive calcium channels (VSCCs) regulate calcium (Ca2+) influx in response to external stimuli. Inhibition or deletion of VSCCs impairs osteogenesis and skeletal responses to mechanical loading. VSCC activity is influenced by its auxiliary subunits, which bind the channel's α1 pore-forming subunit to alter intracellular Ca2+ concentrations. The α2δ1 auxiliary subunit associates with the pore-forming subunit via a glycosylphosphatidylinositol anchor and regulates the channel's calcium-gating kinetics. Knockdown of α2δ1 in osteocytes impairs responses to membrane stretch, and global deletion of α2δ1 in mice results in osteopenia and impaired skeletal responses to loading in vivo. Therefore, we hypothesized that the α2δ1 subunit functions as a mechanotransducer, and its deletion in osteocytes would impair skeletal development and load-induced bone formation. Mice (C57BL/6) with LoxP sequences flanking Cacna2d1, the gene encoding α2δ1, were crossed with mice expressing Cre under the control of the Dmp1 promoter (10 kb). Deletion of α2δ1 in osteocytes and late-stage osteoblasts decreased femoral bone quantity (P < .05) by DXA, reduced relative osteoid surface (P < .05), and altered osteoblast and osteocyte regulatory gene expression (P < .01). Cacna2d1f/f, Cre + male mice displayed decreased femoral strength and lower 10-wk cancellous bone in vivo micro-computed tomography measurements at the proximal tibia (P < .01) compared to controls, whereas Cacna2d1f/f, Cre + female mice showed impaired 20-wk cancellous and cortical bone ex vivo micro-computed tomography measurements (P < .05) vs controls. Deletion of α2δ1 in osteocytes and late-stage osteoblasts suppressed load-induced calcium signaling in vivo and decreased anabolic responses to mechanical loading in male mice, demonstrating decreased mechanosensitivity. Collectively, the α2δ1 auxiliary subunit is essential for the regulation of osteoid-formation, femur strength, and load-induced bone formation in male mice.

The ability of bone to sense and respond to forces generated during daily physical activities is essential to skeletal health. Although several bone cell types contribute to the maintenance of bone health, osteocytes are thought to be the primary mechanosensitive cells; however, the mechanisms through which these cells perceive mechanical stimuli remains unclear. Previous work has shown that voltage sensitive calcium channels are necessary for bone to sense mechanical force; yet the means by which those channels translate the physical signal into a biochemical signal is unclear. Data within this manuscript demonstrate that the extracellular α2δ1 subunit of voltage sensitive calcium channels is necessary for load-induced bone formation as well as to enable calcium influx within osteocytes. As this subunit enables physical interactions of the channel pore with the extracellular matrix, our data demonstrate the need for the α2δ1 subunit for mechanically induced bone adaptation, thus serving as a physical conduit through which mechanical signals from the bone matrix are transduced into biochemical signals by enabling calcium influx into osteocytes.

Splenic irradiation for myelofibrosis prior to hematopoietic cell transplantation: A global collaborative analysis.

Splenomegaly is the clinical hallmark of myelofibrosis. Splenomegaly at the time of allogeneic hematopoietic cell transplantation (HCT) is associated with graft failure and poor graft function. Strategies to reduce spleen size before HCT especially after failure to Janus kinase (JAK) inhibition represent unmet clinical needs in the field. Here, we leveraged a global collaboration to investigate the safety and efficacy of splenic irradiation as part of the HCT platform for patients with myelofibrosis. We included 59 patients, receiving irradiation within a median of 2 weeks (range, 0.9-12 weeks) before HCT. Overall, the median spleen size prior to irradiation was 23 cm (range, 14-35). Splenic irradiation resulted in a significant and rapid spleen size reduction in 97% of patients (57/59), with a median decrease of 5.0 cm (95% confidence interval, 4.1-6.3 cm). The most frequent adverse event was thrombocytopenia, with no correlation between irradiation dose and hematological toxicities. The 3-year overall survival was 62% (95% CI, 48%-76%) and 1-year non-relapse mortality was 26% (95% CI, 14%-38%). Independent predictors for survival were severe thrombocytopenia and anemia before irradiation, transplant-specific risk score, higher-intensity conditioning, and present portal vein thrombosis. When using a propensity score matching adjusted for common confounders, splenic irradiation was associated with significantly reduced relapse (p = .01), showing a 3-year incidence of 12% for splenic irradiation versus 29% for patients with immediate HCT and 38% for patients receiving splenectomy. In conclusion, splenic irradiation immediately before HCT is a reasonable approach in patients experiencing JAK inhibition failure and is associated with a low incidence of relapse.

Hydroxychloroquine Induced Cardiotoxicity: A Case Series.

Hydroxychloroquine (HCQ) induced cardiotoxicity is a rare diagnosis and is often associated with chronic use of the medication. It has been shown that chronic HCQ use is associated with a drug-induced cardiomyopathy mainly driven by acquired lysosomal storage defects leading to hypertrophy and conduction abnormalities. As the only proven treatment is the discontinuation of the offending agent, prompt recognition is required to avoid further exposure to the drug and potential progression of disease. History, physical examination and advanced imaging modalities are useful diagnostic tools, but more invasive testing with an endomyocardial biopsy is required for definitive diagnosis. We present a descriptive case series of ten patients that were diagnosed with biopsy proven HCQ cardiotoxicity.

Impact of Professional Society Guideline Publications in Medicine Subspecialties From 2012 to 2022: Implications for Clinical Care and Health Policy.

Clinical guidelines have become an integral part of clinical care. We assessed professional society-based clinical guidelines from 2012 to 2022 to elucidate the trends in numbers of documents, recommendations, and classes of recommendations. Our results found that 40% of the guidelines do not follow all recommendations made by the Institute of Medicine for trustworthy documents. There has been a significant increase in documents in cardiology, gastroenterology, and hematology/oncology. In addition, of more than 20,000 recommendations, there was significant variability in recommendations made by different professional societies within a specialty. In documents from 11 of the 14 professional societies, more than 50% of the recommendations are supported with the lowest levels of evidence. In cardiology, in addition to the guideline documents, 140 nonguideline documents provide 1812 recommendations using the guideline verbiage, and 74% of the recommendations are supported by the lowest level of evidence. These data have important implications for health care because guidelines and guideline-like documents can be used for health policy issues such as assessment of quality of care, medical liability, education, and payment.

A Rare Case of Cardiac Tamponade in a Patient With Anti-RNA Polymerase III Scleroderma.

Scleroderma is a chronic, progressive autoimmune disease that often presents with multiorgan involvement. Cardiac manifestations are common and include microvascular coronary artery disease, conduction abnormalities, autonomic insufficiency, and pericardial effusions. Although rare, pericardial effusions may progress and lead to cardiac tamponade. Patients diagnosed with scleroderma can be further prognosticated based on the presence of serologic scleroderma-specific antibodies. The anti-RNA polymerase III autoantibody (anti-RNAP3) is associated with an aggressive subtype of scleroderma. Looking at the current literature, no association has been reported between anti-RNAP3 and the development of cardiac tamponade in patients with underlying scleroderma. We discuss a unique case of a patient with scleroderma who was found to be anti-RNAP3 positive and signs of cardiac tamponade. This case illustrates the importance of an expeditious diagnosis and timely interventions to treat cardiac tamponade. Additionally, we share a rare but important association between anti-RNAP3 and the formation of tamponade physiology in scleroderma.

FreiBox: A Versatile Open-Source Behavioral Setup for Investigating the Neuronal Correlates of Behavioral Flexibility via 1-Photon Imaging in Freely Moving Mice.

To survive in a complex and changing environment, animals must adapt their behavior. This ability is called behavioral flexibility and is classically evaluated by a reversal learning paradigm. During such a paradigm, the animals adapt their behavior according to a change of the reward contingencies. To study these complex cognitive functions (from outcome evaluation to motor adaptation), we developed a versatile, low-cost, open-source platform, allowing us to investigate the neuronal correlates of behavioral flexibility with 1-photon calcium imaging. This platform consists of FreiBox, a novel low-cost Arduino behavioral setup, as well as further open-source tools, which we developed and integrated into our framework. FreiBox is controlled by a custom Python interface and integrates a new licking sensor (strain gauge lickometer) for controlling spatial licking behavioral tasks. In addition to allowing both discriminative and serial reversal learning, the Arduino can track mouse licking behavior in real time to control task events in a submillisecond timescale. To complete our setup, we also developed and validated an affordable commutator, which is crucial for recording calcium imaging with the Miniscope V4 in freely moving mice. Further, we demonstrated that FreiBox can be associated with 1-photon imaging and other open-source initiatives (e.g., Open Ephys) to form a versatile platform for exploring the neuronal substrates of licking-based behavioral flexibility in mice. The combination of the FreiBox behavioral setup and our low-cost commutator represents a highly competitive and complementary addition to the recently emerging battery of open-source initiatives.

Conserved structures of neural activity in sensorimotor cortex of freely moving rats allow cross-subject decoding.

Our knowledge about neuronal activity in the sensorimotor cortex relies primarily on stereotyped movements that are strictly controlled in experimental settings. It remains unclear how results can be carried over to less constrained behavior like that of freely moving subjects. Toward this goal, we developed a self-paced behavioral paradigm that encouraged rats to engage in different movement types. We employed bilateral electrophysiological recordings across the entire sensorimotor cortex and simultaneous paw tracking. These techniques revealed behavioral coupling of neurons with lateralization and an anterior-posterior gradient from the premotor to the primary sensory cortex. The structure of population activity patterns was conserved across animals despite the severe under-sampling of the total number of neurons and variations in electrode positions across individuals. We demonstrated cross-subject and cross-session generalization in a decoding task through alignments of low-dimensional neural manifolds, providing evidence of a conserved neuronal code.

3D pose estimation enables virtual head fixation in freely moving rats.

The impact of spontaneous movements on neuronal activity has created the need to quantify behavior. We present a versatile framework to directly capture the 3D motion of freely definable body points in a marker-free manner with high precision and reliability. Combining the tracking with neural recordings revealed multiplexing of information in the motor cortex neurons of freely moving rats. By integrating multiple behavioral variables into a model of the neural response, we derived a virtual head fixation for which the influence of specific body movements was removed. This strategy enabled us to analyze the behavior of interest (e.g., front paw movements). Thus, we unveiled an unexpectedly large fraction of neurons in the motor cortex with tuning to the paw movements, which was previously masked by body posture tuning. Once established, our framework can be efficiently applied to large datasets while minimizing the experimental workload caused by animal training and manual labeling.

Multichannel optogenetics combined with laminar recordings for ultra-controlled neuronal interrogation.

Simultaneous large-scale recordings and optogenetic interventions may hold the key to deciphering the fast-paced and multifaceted dialogue between neurons that sustains brain function. Here we have taken advantage of thin, cell-sized, optical fibers for minimally invasive optogenetics and flexible implantations. We describe a simple procedure for making those fibers side-emitting with a Lambertian emission distribution. Here we combined those fibers with silicon probes to achieve high-quality recordings and ultrafast multichannel optogenetic inhibition. Furthermore, we developed a multi-channel optical commutator and general-purpose patch-cord for flexible experiments. We demonstrate that our framework allows to conduct simultaneous laminar recordings and multifiber stimulations, 3D optogenetic stimulation, connectivity inference, and behavioral quantification in freely moving animals. Our framework paves the way for large-scale photo tagging and controlled interrogation of rapid neuronal communication in any combination of brain areas.

Multifunctional optrode for opsin delivery, optical stimulation, and electrophysiological recordings in freely moving rats.

Objective. Optogenetics involves delivery of light-sensitive opsins to the target brain region, as well as introduction of optical and electrical devices to manipulate and record neural activity, respectively, from the targeted neural population. Combining these functionalities in a single implantable device is of great importance for a precise investigation of neural networks while minimizing tissue damage.Approach. We report on the development, characterization, andin vivovalidation of a multifunctional optrode that combines a silicon-based neural probe with an integrated microfluidic channel, and an optical glass fiber in a compact assembly. The silicon probe comprises an 11-µm-wide fluidic channel and 32 recording electrodes (diameter 30µm) on a tapered probe shank with a length, thickness, and maximum width of 7.5 mm, 50µm, and 150µm, respectively. The size and position of fluidic channels, electrodes, and optical fiber can be precisely tuned according to thein vivoapplication.Main results.With a total system weight of 0.97 g, our multifunctional optrode is suitable for chronicin vivoexperiments requiring simultaneous drug delivery, optical stimulation, and neural recording. We demonstrate the utility of our device in optogenetics by injecting a viral vector carrying a ChR2-construct in the prefrontal cortex and subsequent photostimulation of the transduced neurons while recording neural activity from both the target and adjacent regions in a freely moving rat for up to 9 weeks post-implantation. Additionally, we demonstrate a pharmacological application of our device by injecting GABA antagonist bicuculline in an anesthetized rat brain and simultaneously recording the electrophysiological response.Significance. Our triple-modality device enables a single-step optogenetic surgery. In comparison to conventional multi-step surgeries, our approach achieves higher spatial specificity while minimizing tissue damage.

Distinct dynamics of neuronal activity during concurrent motor planning and execution.

The smooth conduct of movements requires simultaneous motor planning and execution according to internal goals. So far it remains unknown how such movement plans are modified without interfering with ongoing movements. Previous studies have isolated planning and execution-related neuronal activity by separating behavioral planning and movement periods in time by sensory cues. Here, we separate continuous self-paced motor planning from motor execution statistically, by experimentally minimizing the repetitiveness of the movements. This approach shows that, in the rat sensorimotor cortex, neuronal motor planning processes evolve with slower dynamics than movement-related responses. Fast-evolving neuronal activity precees skilled forelimb movements and is nested within slower dynamics. We capture this effect via high-pass filtering and confirm the results with optogenetic stimulations. The various dynamics combined with adaptation-based high-pass filtering provide a simple principle for separating concurrent motor planning and execution.

Role of Bradykinin Type 2 Receptors in Human Sweat Secretion: Translational Evidence Does Not Support a Functional Relationship.

Bradykinin increases skin blood flow via a cGMP mechanism but its role in sweating in vivo is unclear. There is a current need to translate cell culture and nonhuman paw pad studies into in vivo human preparations to test for therapeutic viability for disorders affecting sweat glands. Protocol 1: physiological sweating was induced in 10 healthy subjects via perfusing warm (46-48°C) water through a tube-lined suit while bradykinin type 2 receptor (B2R) antagonist (HOE-140; 40 µM) and only the vehicle (lactated Ringer's) were perfused intradermally via microdialysis. Heat stress increased sweat rate (HOE-140 = +0.79 ± 0.12 and vehicle = +0.64 ± 0.10 mg/cm2/min), but no differences were noted with B2R antagonism. Protocol 2: pharmacological sweating was induced in 6 healthy subjects via intradermally perfusing pilocarpine (1.67 mg/mL) followed by the same B2R antagonist approach. Pilocarpine increased sweating (HOE-140 = +0.38 ± 0.16 and vehicle = +0.32 ± 0.12 mg/cm2/min); again no differences were observed with B2R antagonism. Last, 5 additional subjects were recruited for various control experiments which identified that a functional dose of HOE-140 was utilized and it was not sudorific during normothermic conditions. These data indicate B2R antagonists do not modulate physiologically or pharmacologically induced eccrine secretion volumes. Thus, B2R agonist/antagonist development as a potential therapeutic target for hypo- and hyperhidrosis appears unwarranted.

Effects of Optogenetic Stimulation of Primary Somatosensory Cortex and Its Projections to Striatum on Vibrotactile Perception in Freely Moving Rats.

Tactile sensation is one of our primary means to collect information about the nearby environment and thus crucial for daily activities and survival. Therefore, it is of high importance to restore sensory feedback after sensory loss. Optogenetic manipulation allows local or pathway-specific write-in of information. However, it remains elusive whether optogenetic stimulation can be interpreted as tactile sensation to guide operant behavior and how it is integrated with tactile stimuli. To address these questions, we employed a vibrotactile detection task combined with optogenetic neuromodulation in freely moving rats. By bidirectionally manipulating the activity of neurons in primary somatosensory cortex (S1), we demonstrated that optical activation as well as inhibition of S1 reduced the detection rate for vibrotactile stimuli. Interestingly, activation of corticostriatal terminals improved the detection of tactile stimuli, while inhibition of corticostriatal terminals did not affect the performance. To manipulate the corticostriatal pathway more specifically, we employed a dual viral system. Activation of corticostriatal cell bodies disturbed the tactile perception while activation of corticostriatal terminals slightly facilitated the detection of vibrotactile stimuli. In the absence of tactile stimuli, both corticostriatal cell bodies as well as terminals caused a reaction. Taken together, our data confirmed the possibility to restore sensation using optogenetics and demonstrated that S1 and its descending projections to striatum play differential roles in the neural processing underlying vibrotactile detection.

Real-time detection of neural oscillation bursts allows behaviourally relevant neurofeedback.

Neural oscillations as important information carrier in the brain, are increasingly interpreted as transient bursts rather than as sustained oscillations. Short (<150 ms) bursts of beta-waves (15-30 Hz) have been documented in humans, monkeys and mice. These events were correlated with memory, movement and perception, and were even suggested as the primary ingredient of all beta-band activity. However, a method to measure these short-lived events in real-time and to investigate their impact on behaviour is missing. Here we present a real-time data analysis system, capable to detect short narrowband bursts, and demonstrate its usefulness to increase the beta-band burst-rate in rats. This neurofeedback training induced changes in overall oscillatory power, and bursts could be decoded from the movement of the rats, thus enabling future investigation of the role of oscillatory bursts.

A starting kit for training and establishing in vivo electrophysiology, intracranial pharmacology, and optogenetics.

BACKGROUND: In accordance with the three R principles of research, animal usage should be limited as much as possible. Especially for the training of entry-level scientists in surgical techniques underlying opto- and electrophysiology, alternative training tools are required before moving on to live animals. We have developed a cost-effective rat brain model for training a wide range of surgical techniques, including, but not limited to optogenetics, electrophysiology, and intracranial pharmacological treatments. RESULTS: Our brain model creates a realistic training experience in animal surgery. The success of the surgeries (e.g. implantation accuracy) is readily assessable in cross sections of the model brain. Moreover, the model allows practicing electrophysiological recordings as well as testing for movement or light related artefacts. COMPARISON WITH EXISTING METHOD(S): The surgery and recording experience in our model closely resembles that in an actual rat in terms of the necessary techniques, considerations and time span. A few differences to an actual rat brain slightly reduce the difficulty in our model compared to a live animal. Thus, entry level scientists can first learn basic techniques in our model before moving on to the slightly more complex procedures in live animals. CONCLUSIONS: Our brain model is a useful training tool to equip scientist who are new in the field of electrophysiology and optogenetic manipulations with a basic skill set before applying it in live animals. It can be adapted to fit the desired training content or even to serve in testing and optimizing new lab equipment for more senior scientists.

Silencing of TGFß signalling in microglia results in impaired homeostasis.

TGFß1 has been implicated in regulating functional aspects of several distinct immune cell populations including central nervous system (CNS) resident microglia. Activation and priming of microglia have been demonstrated to contribute to the progression of neurodegenerative diseases and, thus, underlie stringent control by endogenous regulatory factors including TGFß1. Here, we demonstrate that deletion of Tgfbr2 in adult postnatal microglia does neither result in impairment of the microglia-specific gene expression signatures, nor is microglial survival and maintenance affected. Tgfbr2-deficient microglia were characterised by distinct morphological changes and transcriptome analysis using RNAseq revealed that loss of TGFß signalling results in upregulation of microglia activation and priming markers. Moreover, protein arrays demonstrated increased secretion of CXCL10 and CCL2 accompanied by activation of immune cell signalling as evidenced by increased phosphorylation of TAK1. Together, these data underline the importance of microglial TGFß signalling to regulate microglia adaptive changes.

Synthetic cytokine receptors transmit biological signals using artificial ligands.

Cytokine-induced signal transduction is executed by natural biological switches, which among many others control immune-related processes. Here, we show that synthetic cytokine receptors (SyCyRs) can induce cytokine signaling using non-physiological ligands. High-affinity GFP- and mCherry-nanobodies were fused to transmembrane and intracellular domains of the IL-6/IL-11 and IL-23 cytokine receptors gp130 and IL-12Rß1/IL-23R, respectively. Homo- and heterodimeric GFP:mCherry fusion proteins as synthetic cytokine-like ligands were able to induce canonical signaling in vitro and in vivo. Using SyCyR ligands, we show that IL-23 receptor homodimerization results in its activation and IL-23-like signal transduction. Moreover, trimeric receptor assembly induces trans-phosphorylation among cytokine receptors with associated Janus kinases. The SyCyR technology allows biochemical analyses of transmembrane receptor signaling in vitro and in vivo, cell-specific activation through SyCyR ligands using transgenic animals and possible therapeutic regimes involving non-physiological targets during immunotherapy.

Improving the capacity of lithium-sulfur batteries by tailoring the polysulfide adsorption efficiency of hierarchical oxygen/nitrogen-functionalized carbon host materials.

The use of monolithic carbons with structural hierarchy and varying amounts of nitrogen and oxygen functionalities as sulfur host materials in high-loading lithium-sulfur cells is reported. The primary focus is on the strength of the polysulfide/carbon interaction with the goal of assessing the effect of (surface) dopant concentration on cathode performance. The adsorption capacity - which is a measure of the interaction strength between the intermediate lithium polysulfide species and the carbon - was found to scale almost linearly with the nitrogen level. Likewise, the discharge capacity of lithium-sulfur cells increased linearly. This positive correlation can be explained by the favorable effect of nitrogen on both the chemical and electronic properties of the carbon host. The incorporation of additional oxygen-containing surface groups into highly nitrogen-functionalized carbon helped to further enhance the polysulfide adsorption efficiency, and therefore the reversible cell capacity. Overall, the areal capacity could be increased by almost 70% to around 3 mA h cm-2. We believe that the design parameters described here provide a blueprint for future carbon-based nanocomposites for high-performance lithium-sulfur cells.