Exercise-induced potentiation of the acute hypoxic ventilatory response: Neural mechanisms and implications for cerebral blood flow.

A given dose of hypoxia causes a greater increase in pulmonary ventilation during physical exercise than during rest, representing an exercise-induced potentiation of the acute hypoxic ventilatory response (HVR). This phenomenon occurs independently from hypoxic blood entering the contracting skeletal muscle circulation or metabolic byproducts leaving skeletal muscles, supporting the contention that neural mechanisms per se can mediate the HVR when humoral mechanisms are not at play. However, multiple neural mechanisms might be interacting intricately.

Hemodynamic changes in the temporalis and masseter muscles during acute stress in healthy humans.

Purpose: Autonomic control of orofacial areas is an integral part of the stress response, controlling functions such as pupil dilatation, salivation, and skin blood flow. However, the specific control of blood flow in head muscles during stress is unknown. This study aims to investigate the hemodynamic response of temporalis and masseter muscles in response to five different stressors.

Hemodynamic monitoring in the human temporalis muscle using near-infrared spectroscopy.

. Altered temporal muscle perfusion is implicated in several painful disorders afflicting orofacial and head regions, including temporomandibular joint dysfunctions, bruxism, and headache. Knowledge about the regulation of blood supply to the temporalis muscle is limited, due to methodological difficulties.

Ventilatory response to peripheral chemoreflex and muscle metaboreflex during static handgrip in healthy humans: evidence of hyperadditive integration.

New Findings: What is the central question of this study? What is the effect of peripheral chemoreflex and muscle metaboreflex integration on ventilation regulation, and what is the effect of integration on breathing-related sensations and emotions? What is the main finding and its importance? Peripheral chemoreflex and muscle metaboreflex coactivation during isocapnic static handgrip exercise appeared to elicit a hyperadditive effect with regard to ventilation and an additive effect with regard to breathing-related sensations and emotions. These findings reveal the nature of the integration between two neural mechanisms that operate during small-muscle static exercise performed under hypoxia.

Abstract: Exercise augments the hypoxia-induced ventilatory response in an exercise intensity-dependent manner.

Results of Numerical Modeling of Blood Flow in the Internal Jugular Vein Exhibiting Different Types of Strictures.

The clinical relevance of nozzle-like strictures in upper parts of the internal jugular veins remains unclear. This study was aimed at understanding flow disturbances caused by such stenoses. Computational fluid dynamics software, COMSOL Multiphysics, was used.

Novel Eco-Friendly Stability Indicating Capillary Zone Electrophoresis Method for Determination of Aripiprazole in Tablet Dosage form: DoE Directed Optimization, Development and Method Validation.

In this work, a novel environment-friendly stability indicating capillary zone electrophoresis (CZE) method has been developed and validated for assaying the aripiprazole (ARP) in tablet dosage form. The separation of ARP from its degradation products and internal standard was achieved using a fused silica capillary column (30.2 cm x 75 μm ID), a background electrolyte containing 6 mmol L ammonium formate buffer (pH 3) with 5% methanol under a potential of 15 kV and detection at 214 nm.

Cerebrovascular reactivity during visual stimulation: Does hypnotizability matter?

Hypnotizability is a trait associated with several physiological correlates including cardiovascular control. The present study aimed to investigate the posterior cerebral artery flow velocity (PCAv) in basal closed eyes (B) and during visual stimulation (VS) conditions in med-highs and med-lows. Twenty-four healthy volunteers were submitted to the hypnotic assessment through the Stanford Hypnotic Susceptibility Scale, form A which classified 13 low-to-medium (med-lows) and 10 high-to-medium (med-highs) hypnotizable participants.

Does hypnotizability affect neurovascular coupling during cognitive tasks?

Susceptibility to hypnosis is a very pervasive psychophysiological trait characterized by different attentional abilities, information processing, and cardiovascular control. Since near infrared spectroscopy is a good index of neurovascular coupling, we used it during mental computation (MC) and trail making task (TMT) in 13 healthy low-to-medium (med-lows) and 10 healthy medium-to-high (med-highs) hypnotizable participants classified according to the Stanford Hypnotic Susceptibility Scale, form A, and characterized for the level of proneness to be deeply absorbed in related experiences by the Tellegen Absorption Scale. The med-highs reported greater absorption than med-lows.

Differential control of blood flow in masseter and biceps brachii muscles during stress.

Objective: The present study aimed to compare sympathetic hemodynamic effects in masticatory and limb muscles in response to different stressors.

Design: Twelve healthy participants were subjected to a randomized series of stressors, including cold pressor test (CPT), mental arithmetic test, apnea, isometric handgrip (IHG) and post-handgrip muscle ischemia (PHGMI), while in the supine position. Spatially-resolved near-infrared spectroscopy was used to measure relative changes in blood volume and oxygenation (TOI) of the resting masseter and biceps muscles.

Cerebral Blood Flow in Healthy Subjects with Different Hypnotizability Scores.

Hypnotizability is a cognitive trait associated with differences in the brachial artery flow-mediated dilatation of individuals with high hypnotizability (highs) and low hypnotizability scores (lows). The study investigated possible hypnotizability-related cerebrovascular differences. Among 24 healthy volunteers, the Stanford Hypnotic Susceptibility Scale Form A identified 13 medium-to-lows (med-lows), 11 medium-to-highs (med-highs), and 1 medium hypnotizable.

COVID-19-associated meningoencephalitis complicated with intracranial hemorrhage: a case report.

The coronavirus pandemic that started in December 2019 is mainly related to clinical pictures consistent with respiratory symptoms; nevertheless, reports about neurological complications have recently appeared in the medical literature. We describe a case of a 36-year-old coronavirus-positive patient that was admitted on emergency basis; his clinical presentation included neurological symptoms such as drowsiness and mild confusion. Imaging revealed findings consistent with meningoencephalitis complicated by intracerebral hematoma and subdural hematoma.

Solitary bone plasmacytoma: the unusual case of extra-cranial mini brain.

Solitary plasmacytoma is an uncommon tumor. We present a case in an unusually young patient demonstrating the mini brain sign that has been published in a couple of reports as a diagnostic radiological pattern produced by plasmacytoma. Identification of "mini brain appearance" on imaging can direct the radiologist and clinicians to the diagnosis of plasmacytoma and obviate the necessity of pre-operative biopsy.

Serum glial fibrillary acidic protein is related to focal brain injury and outcome after aneurysmal subarachnoid hemorrhage.

Background And Purpose: Aneurysmal subarachnoid hemorrhage (aSAH) stands out from other subtypes of stroke because of the high early mortality and the risk of complications. Serum glial fibrillary acidic protein (s-GFAP) concentrations are increased after stroke. The aim of this study was to investigate whether s-GFAP could be used as a marker of brain damage and outcome after aSAH.