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1.
Circulation ; 146(7): 548-564, 2022 08 16.
Article in English | MEDLINE | ID: mdl-35758040

ABSTRACT

BACKGROUND: Ca2+ signals in smooth muscle cells (SMCs) contribute to vascular resistance and control blood pressure. Increased vascular resistance in hypertension has been attributed to impaired SMC Ca2+ signaling mechanisms. In this regard, transient receptor potential vanilloid 4 (TRPV4SMC) ion channels are a crucial Ca2+ entry pathway in SMCs. However, their role in blood pressure regulation has not been identified. METHODS: We used SMC-specific TRPV4-/- (TRPV4SMC-/-) mice to assess the role of TRPV4SMC channels in blood pressure regulation. We determined the contribution of TRPV4SMC channels to the constrictor effect of α1 adrenergic receptor (α1AR) stimulation and elevated intraluminal pressure: 2 main physiologic stimuli that constrict resistance-sized arteries. The contribution of spatially separated TRPV4SMC channel subpopulations to elevated blood pressure in hypertension was evaluated in angiotensin II-infused mice and patients with hypertension. RESULTS: We provide first evidence that TRPV4SMC channel activity elevates resting blood pressure in normal mice. α1AR stimulation activated TRPV4SMC channels through PKCα (protein kinase Cα) signaling, which contributed significantly to vasoconstriction and blood pressure elevation. Intraluminal pressure-induced TRPV4SMC channel activity opposed vasoconstriction through activation of Ca2+-sensitive K+ (BK) channels, indicating functionally opposite pools of TRPV4SMC channels. Superresolution imaging of SMCs revealed spatially separated α1AR:TRPV4 and TRPV4:BK nanodomains in SMCs. These data suggest that spatially separated α1AR-TRPV4SMC and intraluminal pressure-TRPV4SMC-BK channel signaling have opposite effects on blood pressure, with α1AR-TRPV4SMC signaling dominating under resting conditions. Furthermore, in patients with hypertension and a mouse model of hypertension, constrictor α1AR-PKCα-TRPV4 signaling was upregulated, whereas dilator pressure-TRPV4-BK channel signaling was disrupted, thereby increasing vasoconstriction and elevating blood pressure. CONCLUSIONS: Our data identify novel smooth muscle Ca2+-signaling nanodomains that regulate blood pressure and demonstrate their impairment in hypertension.


Subject(s)
Hypertension , TRPV Cation Channels , Animals , Blood Pressure/physiology , Calcium Signaling , Large-Conductance Calcium-Activated Potassium Channels/metabolism , Mice , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Protein Kinase C-alpha/genetics , Protein Kinase C-alpha/metabolism , Protein Kinase C-alpha/pharmacology , TRPV Cation Channels/genetics , TRPV Cation Channels/metabolism
2.
Pituitary ; 25(6): 988-996, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36261697

ABSTRACT

PURPOSE: Outcomes of patients with non-functioning pituitary adenomas categorized using the 2004 and 2017 WHO classification systems are understudied. We report outcomes from the University of Virginia of patients with non-functioning pituitary adenomas categorized using both systems. METHODS: We constructed a database from all 239 patients who underwent resection of a non-functioning pituitary adenoma between 2003 and 2015 and had at least 5 years of follow-up. Pathologic diagnosis was determined under both the 2004 and 2017 WHO classification systems. We compared the rates of recurrence and progression between subtypes using univariate and multivariate Cox regression analyses. RESULTS: Nearly 30% of the tumors in our database were classified as null cell adenomas under the 2004 classification system, whereas only 10% of the tumors were classified as null cell adenomas using the 2017 classification system. Most of these tumors were reclassified as either corticotroph or gonadotroph adenomas. Despite our relatively large cohort and average follow-up of nearly 9 years, we did not detect a significant difference in recurrence and progression between subtypes. CONCLUSIONS: The majority of null cell adenomas diagnosed under the 2004 WHO classification system are reclassified as gonadotroph or corticotroph adenomas under the 2017 WHO classification system. Rates of progression and recurrence between subtypes are not as different as previously believed at our institution and require a larger cohort to further investigate.


Subject(s)
ACTH-Secreting Pituitary Adenoma , Adenoma , Pituitary Neoplasms , Humans , Pituitary Neoplasms/surgery , Pituitary Neoplasms/pathology , Adenoma/surgery , Adenoma/pathology , ACTH-Secreting Pituitary Adenoma/pathology , World Health Organization
3.
Neurosurg Focus ; 52(3): E7, 2022 03.
Article in English | MEDLINE | ID: mdl-35231897

ABSTRACT

OBJECTIVE: In recent years, hyperoxemia in the intensive care unit has received attention as potentially contributing to negative outcomes in the setting of cardiac arrest, ischemic stroke, and traumatic brain injury. The authors sought to evaluate whether hyperoxemia contributes to worse outcomes in the setting of aneurysmal subarachnoid hemorrhage (aSAH) and to summarize suggested pathophysiological mechanisms. METHODS: A systematic literature review was conducted without date restrictions on the PubMed and Web of Science databases on September 15, 2021. All studies that assessed the relationship between patients treated for aSAH and hyperoxemia were eligible independent of the criteria used to define hyperoxemia. All nonclinical studies and studies that did not report outcome data specific to patients with aSAH were excluded. A total of 102 records were found and screened, resulting in assessment of 10 full-text studies, of which 7 met eligibility criteria. Risk of bias was assessed using the Downs and Black checklist. A meta-analysis on the pooled 2602 patients was performed, and forest plots were constructed. Additionally, a review of the literature was performed to summarize available data regarding the pathophysiology of hyperoxemia. RESULTS: The included studies demonstrated an association between hyperoxemia and increased morbidity and mortality following aSAH. The criteria used to determine hyperoxemia varied among studies. Pooling of univariate data showed hyperoxemia to be associated with poor neurological outcome (OR 2.26, 95% CI 1.66-3.07; p < 0.001), delayed cerebral ischemia (DCI) (OR 1.91, 95% CI 1.31-2.78; p < 0.001), and increased incidence of poor neurological outcome or mortality as a combined endpoint (OR 2.36, 95% CI 1.87-2.97; p < 0.001). Pooling of multivariable effect sizes showed the same relationship for poor neurological outcome (OR 1.28, 95% CI 1.07-1.55; p = 0.01) and poor neurological outcome and mortality as a combined endpoint (OR 1.17, 95% CI 1.11-1.23; p < 0.001). Additionally, review of preclinical studies underlined the contribution of oxidative stress due to hyperoxemia to acute secondary brain injury and DCI. CONCLUSIONS: Reported outcomes from the available studies have indicated that hyperoxemia is associated with worse neurological outcome, mortality, and DCI. These findings provide a general guideline toward avoiding hyperoxemia in the acute setting of aSAH. Further studies are needed to determine the optimal ventilation and oxygenation parameters for acute management of this patient population.


Subject(s)
Brain Ischemia , Subarachnoid Hemorrhage , Vasospasm, Intracranial , Brain Ischemia/etiology , Humans , Incidence , Subarachnoid Hemorrhage/complications , Subarachnoid Hemorrhage/drug therapy , Vasospasm, Intracranial/etiology
4.
Acta Neurochir (Wien) ; 164(5): 1293-1296, 2022 05.
Article in English | MEDLINE | ID: mdl-35137269

ABSTRACT

BACKGROUND: Classically, access for neuroendovascular procedures is facilitated via groin or wrist puncture, entering the femoral or radial artery, respectively. However, in some instances, adequate intracranial access is not obtainable with those approaches due to vessel tortuosity or unfavorable anatomy. We describe a thrombectomy for stroke that was complicated by inability to achieve intracranial access via standard approaches. METHOD: To circumvent difficulties obtaining intracranial access, we entered the arterial circulation via a direct carotid puncture. CONCLUSION: Direct carotid puncture is an alternative access route for neuroendovascular procedures when intracranial access is not achievable by femoral or radial approaches due to unfavorable vascular anatomy.


Subject(s)
Endovascular Procedures , Stroke , Endovascular Procedures/adverse effects , Humans , Punctures/adverse effects , Stroke/etiology , Thrombectomy/adverse effects , Treatment Outcome
5.
Circulation ; 141(16): 1318-1333, 2020 04 21.
Article in English | MEDLINE | ID: mdl-32008372

ABSTRACT

BACKGROUND: Impaired endothelium-dependent vasodilation is a hallmark of obesity-induced hypertension. The recognition that Ca2+ signaling in endothelial cells promotes vasodilation has led to the hypothesis that endothelial Ca2+ signaling is compromised during obesity, but the underlying abnormality is unknown. In this regard, transient receptor potential vanilloid 4 (TRPV4) ion channels are a major Ca2+ influx pathway in endothelial cells, and regulatory protein AKAP150 (A-kinase anchoring protein 150) enhances the activity of TRPV4 channels. METHODS: We used endothelium-specific knockout mice and high-fat diet-fed mice to assess the role of endothelial AKAP150-TRPV4 signaling in blood pressure regulation under normal and obese conditions. We further determined the role of peroxynitrite, an oxidant molecule generated from the reaction between nitric oxide and superoxide radicals, in impairing endothelial AKAP150-TRPV4 signaling in obesity and assessed the effectiveness of peroxynitrite inhibition in rescuing endothelial AKAP150-TRPV4 signaling in obesity. The clinical relevance of our findings was evaluated in arteries from nonobese and obese individuals. RESULTS: We show that Ca2+ influx through TRPV4 channels at myoendothelial projections to smooth muscle cells decreases resting blood pressure in nonobese mice, a response that is diminished in obese mice. Counterintuitively, release of the vasodilator molecule nitric oxide attenuated endothelial TRPV4 channel activity and vasodilation in obese animals. Increased activities of inducible nitric oxide synthase and NADPH oxidase 1 enzymes at myoendothelial projections in obese mice generated higher levels of nitric oxide and superoxide radicals, resulting in increased local peroxynitrite formation and subsequent oxidation of the regulatory protein AKAP150 at cysteine 36, to impair AKAP150-TRPV4 channel signaling at myoendothelial projections. Strategies that lowered peroxynitrite levels prevented cysteine 36 oxidation of AKAP150 and rescued endothelial AKAP150-TRPV4 signaling, vasodilation, and blood pressure in obesity. Peroxynitrite-dependent impairment of endothelial TRPV4 channel activity and vasodilation was also observed in the arteries from obese patients. CONCLUSIONS: These data suggest that a spatially restricted impairment of endothelial TRPV4 channels contributes to obesity-induced hypertension and imply that inhibiting peroxynitrite might represent a strategy for normalizing endothelial TRPV4 channel activity, vasodilation, and blood pressure in obesity.


Subject(s)
Blood Pressure , Diet, High-Fat/adverse effects , Endothelium, Vascular , Hypertension , Obesity , Peroxynitrous Acid/metabolism , TRPV Cation Channels/metabolism , A Kinase Anchor Proteins/genetics , A Kinase Anchor Proteins/metabolism , Animals , Calcium Signaling , Endothelium, Vascular/metabolism , Endothelium, Vascular/physiopathology , Heme Oxygenase-1/genetics , Heme Oxygenase-1/metabolism , Humans , Hypertension/genetics , Hypertension/metabolism , Hypertension/physiopathology , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Mice, Knockout , Obesity/genetics , Obesity/metabolism , Obesity/physiopathology , Peroxynitrous Acid/genetics , TRPV Cation Channels/genetics , Vasodilation
6.
Neurosurg Focus ; 48(4): E17, 2020 04 01.
Article in English | MEDLINE | ID: mdl-32234990

ABSTRACT

Arteriovenous malformation (AVM) presenting with epilepsy significantly impacts patient quality of life, and it should be considered very much a seizure disorder. Although hemorrhage prevention is the primary treatment aim of AVM surgery, seizure control should also be at the forefront of therapeutic management. Several hemodynamic and morphological characteristics of AVM have been identified to be associated with seizure presentation. This includes increased AVM flow, presence of long pial draining vein, venous outflow obstruction, and frontotemporal location, among other aspects. With the advent of high-throughput image processing and quantification methods, new radiographic attributes of AVM-related epilepsy have been identified. With respect to therapy, several treatment approaches are available, including conservative management or interventional modalities; this includes microsurgery, radiosurgery, and embolization or a combination thereof. Many studies, especially in the domain of microsurgery and radiosurgery, evaluate both techniques with respect to seizure outcomes. The advantage of microsurgery lies in superior AVM obliteration rates and swift seizure response. In addition, by incorporating electrophysiological monitoring during AVM resection, adjacent or even remote epileptogenic foci can be identified, leading to extended lesionectomy and improved seizure control. Radiosurgery, despite resulting in reduced AVM obliteration and prolonged time to seizure freedom, avoids the risks of surgery altogether and may provide seizure control through various antiepileptic mechanisms. Embolization continues to be used as an adjuvant for both microsurgery and radiosurgery. In this study, the authors review the latest imaging techniques in characterizing AVM-related epilepsy, in addition to reviewing each treatment modality.


Subject(s)
Epilepsy/diagnosis , Epilepsy/surgery , Intracranial Arteriovenous Malformations/surgery , Seizures/surgery , Embolization, Therapeutic/methods , Female , Humans , Intracranial Arteriovenous Malformations/diagnosis , Male , Quality of Life , Radiosurgery/methods , Retrospective Studies , Treatment Outcome
7.
Nature ; 497(7448): 263-7, 2013 May 09.
Article in English | MEDLINE | ID: mdl-23615608

ABSTRACT

Skeletal muscle arises from the fusion of precursor myoblasts into multinucleated myofibres. Although conserved transcription factors and signalling proteins involved in myogenesis have been identified, upstream regulators are less well understood. Here we report an unexpected discovery that the membrane protein BAI1, previously linked to recognition of apoptotic cells by phagocytes, promotes myoblast fusion. Endogenous BAI1 expression increased during myoblast fusion, and BAI1 overexpression enhanced myoblast fusion by means of signalling through ELMO/Dock180/Rac1 proteins. During myoblast fusion, a fraction of myoblasts within the population underwent apoptosis and exposed phosphatidylserine, an established ligand for BAI1 (ref. 3). Blocking apoptosis potently impaired myoblast fusion, and adding back apoptotic myoblasts restored fusion. Furthermore, primary human myoblasts could be induced to form myotubes by adding apoptotic myoblasts, even under normal growth conditions. Mechanistically, apoptotic cells did not directly fuse with the healthy myoblasts, rather the apoptotic cells induced a contact-dependent signalling with neighbours to promote fusion among the healthy myoblasts. In vivo, myofibres from Bai1(-/-) mice are smaller than those from wild-type littermates. Muscle regeneration after injury was also impaired in Bai1(-/-)mice, highlighting a role for BAI1 in mammalian myogenesis. Collectively, these data identify apoptotic cells as a new type of cue that induces signalling via the phosphatidylserine receptor BAI1 to promote fusion of healthy myoblasts, with important implications for muscle development and repair.


Subject(s)
Angiogenic Proteins/metabolism , Apoptosis/physiology , Cell Fusion , Muscle, Skeletal/cytology , Myoblasts/cytology , Receptors, Cell Surface/metabolism , Signal Transduction , Angiogenic Proteins/deficiency , Angiogenic Proteins/genetics , Animals , Apoptosis/drug effects , Cell Communication , Cell Differentiation , Cell Line , Humans , Male , Mice , Mice, Inbred C57BL , Muscle Development , Muscle Fibers, Skeletal/cytology , Muscle Fibers, Skeletal/metabolism , Muscle Fibers, Skeletal/pathology , Muscle, Skeletal/metabolism , Myoblasts/metabolism , Phosphatidylserines/metabolism , Receptors, Cell Surface/deficiency , Receptors, Cell Surface/genetics
8.
Spinal Cord ; 57(9): 729-738, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31358909

ABSTRACT

Enhanced recovery after surgery (ERAS) is an evidence-based approach developed to ameliorate the patient recovery process following surgical procedures. Employing a multimodal, multidisciplinary approach, ERAS implements strategies and treatment paradigms that have been shown to improve patient outcomes, reduce hospital length of stay, and ultimately reduce healthcare costs. With a substantial body of the literature supporting the implementation of ERAS in other surgical specialties, ERAS has only recently made its foray into spine surgery. Despite this, current studies are limited to spinal deformity and degenerative disease, with limited data regarding spinal cord surgery. This is due in part to the complex nature and rarity of spinal cord lesions, making the establishment of a formal ERAS protocol difficult. In developing an ERAS protocol, there must be a consensus on what factors are important to consider and implement. To address this, we reviewed the most recent advances in intramedullary and extramedullary spinal cord surgery in order to identify elements that influence patient outcomes. Using this information, the authors provide evidence-based recommendations with the intent of introducing a framework for future ERAS protocols with respect to treating spinal cord lesions.


Subject(s)
Enhanced Recovery After Surgery/standards , Perioperative Care/standards , Spinal Cord Diseases/diagnostic imaging , Spinal Cord Diseases/surgery , Humans , Perioperative Care/methods , Spinal Cord Neoplasms/diagnostic imaging , Spinal Cord Neoplasms/surgery
9.
Neurosurg Focus ; 46(4): E3, 2019 04 01.
Article in English | MEDLINE | ID: mdl-30933920

ABSTRACT

OBJECTIVEEnhanced recovery after surgery (ERAS) is a multidimensional approach to improving the care of surgical patients using subspecialty- and procedure-specific evidence-based protocols. The literature provides evidence of the benefits of ERAS implementation, which include expedited functional recovery, decreased postoperative morbidity, reduced costs, and improved subjective patient experience. Although extensively examined in other surgical areas, ERAS principles have been applied to spine surgery only in recent years. The authors examine studies investigating the application of ERAS programs to patients undergoing spine surgery.METHODSThe authors conducted a systematic review of the PubMed and MEDLINE databases up to November 20, 2018.RESULTSTwenty full-text articles were included in the qualitative analysis. The majority of studies were retrospective reviews of nonrandomized data sets or qualitative investigations lacking formal control groups; there was 1 protocol for a future randomized controlled trial. Most studies demonstrated reduced lengths of stay and no increase in rates of readmissions or complications after introduction of an ERAS pathway.CONCLUSIONSThese introductory studies demonstrate the potential of ERAS protocols, when applied to spine procedures, to reduce lengths of stay, accelerate return of function, minimize postoperative pain, and save costs.


Subject(s)
Enhanced Recovery After Surgery , Neurosurgical Procedures/methods , Spine/surgery , Humans , Spinal Fusion
10.
Neurosurg Focus ; 46(2): E2, 2019 02 01.
Article in English | MEDLINE | ID: mdl-30717070

ABSTRACT

While the majority of cerebral revascularization advancements were made in the last century, it is worth noting the humble beginnings of vascular surgery throughout history to appreciate its progression and application to neurovascular pathology in the modern era. Nearly 5000 years of basic human inquiry into the vasculature and its role in neurological disease has resulted in the complex neurosurgical procedures used today to save and improve lives. This paper explores the story of the extracranial-intracranial approach to cerebral revascularization.


Subject(s)
Cerebral Revascularization/history , Nervous System Diseases/history , Neurosurgical Procedures/history , Circle of Willis/anatomy & histology , Circle of Willis/surgery , History, 19th Century , History, 20th Century , History, 21st Century , History, Ancient , History, Medieval , Humans , Nervous System Diseases/surgery
11.
Neurosurg Focus ; 47(6): E8, 2019 12 01.
Article in English | MEDLINE | ID: mdl-31786558

ABSTRACT

Contrast-enhanced ultrasound (CEUS) is a relatively new imaging modality in the realm of neurosurgical disease. CEUS permits the examination of blood flow through arteries, veins, and capillaries via intravascular contrast agents and allows vascular architectural mapping with extreme sensitivity and specificity. While it has established utility in other organ systems such as the liver and kidneys, CEUS has not been studied extensively in the brain. This report presents a review of the literature on the neurosurgical applications of CEUS and provides an outline of the imaging modality's role in the diagnosis, evaluation, and treatment of neurosurgical disease.


Subject(s)
Brain Diseases/diagnostic imaging , Contrast Media , Microbubbles , Neuroimaging/methods , Ultrasonography/methods , Brain Diseases/surgery , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/surgery , Carotid Artery Diseases/diagnostic imaging , Carotid Artery Diseases/surgery , Cerebrovascular Disorders/diagnostic imaging , Cerebrovascular Disorders/surgery , Forecasting , Humans , Ultrasonography, Interventional/methods
12.
Neurosurg Focus ; 47(1): E11, 2019 07 01.
Article in English | MEDLINE | ID: mdl-31261115

ABSTRACT

The pathogenesis of intracranial aneurysms remains complex and multifactorial. While vascular, genetic, and epidemiological factors play a role, nascent aneurysm formation is believed to be induced by hemodynamic forces. Hemodynamic stresses and vascular insults lead to additional aneurysm and vessel remodeling. Advanced imaging techniques allow us to better define the roles of aneurysm and vessel morphology and hemodynamic parameters, such as wall shear stress, oscillatory shear index, and patterns of flow on aneurysm formation, growth, and rupture. While a complete understanding of the interplay between these hemodynamic variables remains elusive, the authors review the efforts that have been made over the past several decades in an attempt to elucidate the physical and biological interactions that govern aneurysm pathophysiology. Furthermore, the current clinical utility of hemodynamics in predicting aneurysm rupture is discussed.


Subject(s)
Aneurysm, Ruptured/physiopathology , Biophysics , Hemodynamics , Intracranial Aneurysm/physiopathology , Animals , Disease Progression , Humans , Stress, Physiological
13.
Neurosurg Focus ; 47(6): E5, 2019 12 01.
Article in English | MEDLINE | ID: mdl-31786550

ABSTRACT

Neuroimaging is an indispensable tool in the workup and management of patients with neurological disorders. Arterial spin labeling (ASL) is an imaging modality that permits the examination of blood flow and perfusion without the need for contrast injection. Noninvasive in nature, ASL provides a feasible alternative to existing vascular imaging techniques, including angiography and perfusion imaging. While promising, ASL has yet to be fully incorporated into the diagnosis and management of neurological disorders. This article presents a review of the most recent literature on ASL, with a special focus on its use in moyamoya disease, brain neoplasms, seizures, and migraines and a commentary on recent advances in ASL that make the imaging technique more attractive as a clinically useful tool.


Subject(s)
Brain Diseases/diagnostic imaging , Cerebral Angiography/methods , Cerebral Arteries/diagnostic imaging , Magnetic Resonance Angiography/methods , Magnetic Resonance Imaging/methods , Neuroimaging/methods , Brain Neoplasms/diagnostic imaging , Cerebrovascular Circulation , Glioma/diagnostic imaging , Meningeal Neoplasms/diagnostic imaging , Meningioma/diagnostic imaging , Migraine Disorders/diagnostic imaging , Moyamoya Disease/diagnostic imaging , Protons , Radio Waves , Seizures/diagnostic imaging , Water
14.
Synapse ; 72(1)2018 01.
Article in English | MEDLINE | ID: mdl-28960461

ABSTRACT

The dismantling and elimination of excess neurons and their connections (pruning) is essential for brain development and may be aberrantly reactivated in some neurodegenerative diseases. Growing evidence implicates caspase-mediated apoptotic and nonapoptotic cascades in the dysfunction and death of neurons in neurodegenerative disorders such as Alzheimer's, Parkinson, and Huntington's diseases. It is the cleaved caspase substrates that are the effectors of synapse elimination. However, their identities, specific cleavage sites, and functional consequences of cleavage are largely unknown. An important gap in our knowledge is a comprehensive catalog of synapse-specific or synapse-enriched caspase targets. Traditional biochemical approaches have revealed only a small number of neuronal caspase targets. Instead, we utilized a gel-based proteomics approach to enable the first global analysis of caspase-mediated cleavage events in mammalian brain synapses, employing both an in vitro system with recombinant activated caspases and an in vivo model of ethanol-induced neuronal apoptosis. Of the more than 70 putative cleavage substrates that were identified, 22 were previously known caspase substrates. Among the novel targets identified and validated by Western blot were the proton pump ATPase subunit ATP6V1B2 and the N-ethylmaleimide-sensitive fusion protein (NSF). Our work represents the first comprehensive, proteome-wide screen for proteolytic targets of caspases in neuronal synapses. Our discoveries will have significance for both furthering basic understanding of roles of caspases in synaptic plasticity and synaptic loss in neurodegeneration, and on a more immediately practical level, may provide candidate biomarkers for measuring synapse loss in human disease states.


Subject(s)
Caspases/metabolism , Proteome , Synapses/metabolism , Animals , Apoptosis/drug effects , Apoptosis/physiology , Blotting, Western , Brain/drug effects , Brain/metabolism , Caspases/administration & dosage , Ethanol/toxicity , Humans , Immunohistochemistry , Male , Mass Spectrometry , Mice, Inbred C57BL , N-Ethylmaleimide-Sensitive Proteins/metabolism , Proteomics , Recombinant Proteins/administration & dosage , Recombinant Proteins/metabolism , Synapses/drug effects , Vacuolar Proton-Translocating ATPases/metabolism
15.
Acta Neurochir (Wien) ; 158(9): 1697-700, 2016 09.
Article in English | MEDLINE | ID: mdl-27435739

ABSTRACT

Treating pituitary adenomas in the infundibulum with stereotactic radiosurgery (SRS), achieving tumor volume control while preserving pituitary endocrine function and visual function, is challenging. We present a case of a recurrent remnant infundibular lesion treated with Gamma Knife surgery (GKS). The mass was treated with microsurgical resection twice, and the residual stalk lesion was treated with single-session SRS employing a margin dose of 15 Gy to the infundibulum. Five years after GKS, tumor regression persists without visual dysfunction or hypopituitarism. Radiosurgical doses of 30 Gy to the pituitary stalk may be tolerated by patients while maintaining endocrine function.


Subject(s)
Adenoma/surgery , Pituitary Gland, Anterior/surgery , Pituitary Neoplasms/surgery , Radiosurgery/methods , Humans , Male , Middle Aged , Pituitary Gland, Anterior/pathology , Postoperative Complications/etiology , Postoperative Complications/prevention & control , Radiosurgery/adverse effects
16.
J Clin Med ; 12(11)2023 May 30.
Article in English | MEDLINE | ID: mdl-37297949

ABSTRACT

Stroke is an emergency in which delays in treatment can lead to significant loss of neurological function and be fatal. Technologies that increase the speed and accuracy of stroke diagnosis or assist in post-stroke rehabilitation can improve patient outcomes. No resource exists that comprehensively assesses artificial intelligence/machine learning (AI/ML)-enabled technologies indicated for the management of ischemic and hemorrhagic stroke. We queried a United States Food and Drug Administration (FDA) database, along with PubMed and private company websites, to identify the recent literature assessing the clinical performance of FDA-approved AI/ML-enabled technologies. The FDA has approved 22 AI/ML-enabled technologies that triage brain imaging for more immediate diagnosis or promote post-stroke neurological/functional recovery. Technologies that assist with diagnosis predominantly use convolutional neural networks to identify abnormal brain images (e.g., CT perfusion). These technologies perform comparably to neuroradiologists, improve clinical workflows (e.g., time from scan acquisition to reading), and improve patient outcomes (e.g., days spent in the neurological ICU). Two devices are indicated for post-stroke rehabilitation by leveraging neuromodulation techniques. Multiple FDA-approved technologies exist that can help clinicians better diagnose and manage stroke. This review summarizes the most up-to-date literature regarding the functionality, performance, and utility of these technologies so clinicians can make informed decisions when using them in practice.

17.
Front Neurol ; 14: 1170675, 2023.
Article in English | MEDLINE | ID: mdl-37409019

ABSTRACT

Stroke remains a major burden on patients, families, and healthcare professionals, despite major advances in prevention, acute treatment, and rehabilitation. Preclinical basic research can help to better define mechanisms contributing to stroke pathology, and identify therapeutic interventions that can decrease ischemic injury and improve outcomes. Animal models play an essential role in this process, and mouse models are particularly well-suited due to their genetic accessibility and relatively low cost. Here, we review the focal cerebral ischemia models with an emphasis on the middle cerebral artery occlusion technique, a "gold standard" in surgical ischemic stroke models. Also, we highlight several histologic, genetic, and in vivo imaging approaches, including mouse stroke MRI techniques, that have the potential to enhance the rigor of preclinical stroke evaluation. Together, these efforts will pave the way for clinical interventions that can mitigate the negative impact of this devastating disease.

18.
Article in English | MEDLINE | ID: mdl-37545759

ABSTRACT

Background-: Transplantation of autologous mitochondria into ischemic tissue may mitigate injury caused by ischemia and reperfusion. Methods-: Using murine stroke models of middle cerebral artery occlusion, we sought to evaluate feasibility of delivery of viable mitochondria to ischemic brain parenchyma. We evaluated the effects of concurrent focused ultrasound activation of microbubbles, which serves to open the blood-brain barrier, on efficacy of delivery of mitochondria. Results-: Following intra-arterial delivery, mitochondria distribute through the stroked hemisphere and integrate into neural and glial cells in the brain parenchyma. Consistent with functional integration in the ischemic tissue, the transplanted mitochondria elevate concentration of adenosine triphosphate in the stroked hemisphere, reduce infarct volume and increase cell viability. Additional of focused ultrasound leads to improved blood brain barrier opening without hemorrhagic complications. Conclusions-: Our results have implications for the development of interventional strategies after ischemic stroke and suggest a novel potential modality of therapy after mechanical thrombectomy.

19.
Am J Pathol ; 178(4): 1416-28, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21435432

ABSTRACT

The cellular and molecular mechanisms of phagocytic clearance of apoptotic cells and debris have been intensely studied in invertebrate model organisms and in the mammalian immune system. This evolutionarily conserved process serves multiple purposes. Uncleared debris from dying cells or aggregated proteins can be toxic and may trigger exaggerated inflammatory responses. Even though apoptotic cell death and debris accumulation are key features of neurodegenerative diseases, relatively little attention has been paid to this important homeostatic function in the central nervous system (CNS). This review attempts to summarize our knowledge of phagocytic clearance in the CNS, with a focus on retinal degeneration, forms of which are caused by mutations in genes within known phagocytic pathways, and on Alzheimer's disease (AD). Interest in phagocytic clearance mechanisms in AD was stimulated by the discovery that immunization could promote phagocytic clearance of amyloid-ß; however, much less is known about clearance of neuronal and synaptic corpses in AD and other neurodegenerative diseases. Because the regulation of phagocytic activity is intertwined with cytokine signaling, this review also addresses the relationships among CNS inflammation, glial responses, and phagocytic clearance.


Subject(s)
Nerve Degeneration/immunology , Phagocytes/cytology , Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Animals , Central Nervous System/pathology , Complement System Proteins , Humans , Inflammation , Molecular Chaperones/metabolism , Nerve Degeneration/metabolism , Neurodegenerative Diseases/immunology , Neurodegenerative Diseases/metabolism , Neuroglia/metabolism , Phagocytosis , Synapses/metabolism
20.
Surg Neurol Int ; 13: 367, 2022.
Article in English | MEDLINE | ID: mdl-36128166

ABSTRACT

Background: Drugs of abuse have been associated with ischemic stroke; however, the clinical presentation, outcomes, and treatment data in this population are limited. The overall safety and efficacy of thrombolytic therapy and thrombectomy in these patients remain unclear. This scoping review summarizes published complications and clinical outcomes in patients with recent abuse of cocaine, methamphetamine (MA), cannabis, decongestant, opioids, alcohol, and 3,4-methylenedioxymethamphetamine (MDMA) presenting with acute ischemic stroke. Methods: We conducted a scoping review of the primary literature that assessed outcomes data of thrombolytic therapy or thrombectomy in drug users with acute ischemic stroke. We searched PubMed, Ovid Medline, and Web of Science. Demographic and stroke characteristics, treatment, complications, and clinical outcomes at last follow-up were collected and summarized. Results: We identified 51 studies in this review. Drugs of abuse of interest were cocaine (14 studies), MDMA (one study), MA (eight studies), cannabis (23 studies), alcohol (two studies), decongestants (one study), and opioids (two studies). Clinical presentation and stroke presentation were most commonly described features. Thrombectomy outcomes were reported for four patients total (two studies), all with history of cocaine use. Thrombolysis treatment and outcomes were reported for 8851 patients (five studies) with history of cocaine, alcohol, or cannabis. Both treatments were pursued in three patients (three studies). Treatment complications included intracerebral hemorrhage, vasospasm, and cerebral edema. Conclusion: Evidence for thrombolytic and thrombectomy treatment in drug users remains limited. Controlled studies are needed to examine complication profile and outcomes following thrombolytic and thrombectomy treatment in this population.

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