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International Journal of Molecular... Jun 2024Canonical transient receptor potential channel 3 (TRPC3) is the most abundant TRPC channel in the brain and is highly expressed in all subfields of the hippocampus....
Canonical transient receptor potential channel 3 (TRPC3) is the most abundant TRPC channel in the brain and is highly expressed in all subfields of the hippocampus. Previous studies have suggested that TRPC3 channels may be involved in the hyperexcitability of hippocampal pyramidal neurons and seizures. Genetic ablation of TRPC3 channel expression reduced the intensity of pilocarpine-induced status epilepticus (SE). However, the underlying cellular mechanisms remain unexplored and the contribution of TRPC3 channels to SE-induced neurodegeneration is not determined. In this study, we investigated the contribution of TRPC3 channels to the electrophysiological properties of hippocampal pyramidal neurons and hippocampal synaptic plasticity, and the contribution of TRPC3 channels to seizure-induced neuronal cell death. We found that genetic ablation of TRPC3 expression did not alter basic electrophysiological properties of hippocampal pyramidal neurons and had a complex impact on epileptiform bursting in CA3. However, TRPC3 channels contribute significantly to long-term potentiation in CA1 and SE-induced neurodegeneration. Our results provided further support for therapeutic potential of TRPC3 inhibitors and raised new questions that need to be answered by future studies.
Topics: Animals; TRPC Cation Channels; Mice; Cell Death; Pyramidal Cells; Hippocampus; Seizures; Status Epilepticus; Male; Neurons; Pilocarpine; Long-Term Potentiation; Mice, Knockout; Mice, Inbred C57BL; Neuronal Plasticity
PubMed: 38892448
DOI: 10.3390/ijms25116260 -
Zhonghua Yi Xue Za Zhi Jun 2024The bronchial provocation test (BPT) is an important clinical examination to detect airway hyperresponsiveness, primarily in diagnosing asthma with FEV≥70% of...
The bronchial provocation test (BPT) is an important clinical examination to detect airway hyperresponsiveness, primarily in diagnosing asthma with FEV≥70% of predicted value, including typical asthma and atypical asthma such as cough variant asthma and chest tightness variant asthma. BPT is a valuable tool in differentiating asthma from other chronic airway diseases and assessing the efficacy of asthma treatment. Despite its clinical significance, BPT remains largely underused in clinical practice, primarily due to limited knowledge of its importance and inadequate availability of medical professionals, equipment and medications in primary care settings. In response to this gap, the China Asthma Group of Chinese Thoracic Society has drafted this expert consensus to enhance knowledge and application of BPT among clinical practitioners. This expert consensus specifically focuses on the classic direct provocation agent methacholine, covering general principles and classification of BPT; indications, contraindications, and clinical applications; result interpretation; analyzing potential reasons and coping strategies for false positive and false negative test results; and finally, providing safety precautions and emergency measures. The aim of this expert consensus is to promote the standardized application of BPT.
Topics: Humans; Asthma; Bronchial Provocation Tests; China; Consensus; Methacholine Chloride; East Asian People
PubMed: 38858213
DOI: 10.3760/cma.j.cn112137-20240202-00252 -
Journal of Pharmaceutical Sciences Jun 2024Exploiting a convenient and highly bioavailable ocular drug delivery approach is currently one of the hotspots in the pharmaceutical industry. Eyelid topical application...
Exploiting a convenient and highly bioavailable ocular drug delivery approach is currently one of the hotspots in the pharmaceutical industry. Eyelid topical application is seen to be a valuable strategy in the treatment of chronic ocular diseases. To further elucidate the feasibility of eyelid topical administration as an alternative route for ocular drug delivery, pharmacokinetic and pharmacodynamic studies of pilocarpine were conducted in rabbits. Besides, a novel physiologically based pharmacokinetic (PBPK) model describing eyelid transdermal absorption and ocular disposition was developed in rabbits. The PBPK model of rabbits was extrapolated to human by integrating the drug-specific permeability parameters and human physiological parameters to predict ocular pharmacokinetic in human. After eyelid topical application of pilocarpine, the concentration of pilocarpine in iris peaked at 2 h with the value of 18,724 ng/g and the concentration in aqueous humor peaked at 1 h with the value of 1,363 ng/mL. Significant miotic effect were observed from 0.5 h to 4.5 h after eyelid topical application of pilocarpine in rabbits, while that were observed from 0.5 h to 3.5 h after eyedrop instillation. The proposed eyelid PBPK model was capable of reasonably predicting ocular exposure of pilocarpine after application on the eyelid skin and based on the PBPK model, the human ocular concentration was predicted to be 10-fold lower than that in rabbits. And it was suggested that drugs applied on the eyelid skin could transfer into the eyeball through corneal pathway and scleral pathway. This work could provide pharmacokinetic and pharmacodynamic data for the development of eyelid drug delivery, as well as the reference for clinical applications.
PubMed: 38857643
DOI: 10.1016/j.xphs.2024.06.004 -
Respiratory Medicine 2024Salbutamol is a cornerstone for relieving acute asthma symptoms, typically administered through a pressurized metered-dose inhaler (pMDI). Dry powder inhalers (DPIs)... (Randomized Controlled Trial)
Randomized Controlled Trial Comparative Study
BACKGROUND
Salbutamol is a cornerstone for relieving acute asthma symptoms, typically administered through a pressurized metered-dose inhaler (pMDI). Dry powder inhalers (DPIs) offer an alternative, but concerns exist whether DPIs provide an effective relief during an obstructive event.
OBJECTIVE
We aimed to show non-inferiority of Salbutamol Easyhaler DPI compared to pMDI with spacer in treating methacholine-induced bronchoconstriction. Applicability of Budesonide-formoterol Easyhaler DPI as a reliever was also assessed.
METHODS
This was a randomized, parallel-group trial in subjects sent to methacholine challenge (MC) test for asthma diagnostics. Participants with at least 20 % decrease in forced expiratory volume in 1 s (FEV) were randomized to receive Salbutamol Easyhaler (2 × 200 μg), Ventoline Evohaler with spacer (4 × 100 μg) or Budesonide-formoterol Easyhaler (2 × 160/4.5 μg) as a reliever. The treatment was repeated if FEV did not recover to at least -10 % of baseline.
RESULTS
180 participants (69 % females, mean age 46 yrs [range 18-80], FEV%pred 89.5 [62-142] %) completed the trial. Salbutamol Easyhaler was non-inferior to pMDI with spacer in acute relief of bronchoconstriction showing a -0.083 (95 % LCL -0.146) L FEV difference after the first dose and -0.032 (-0.071) L after the last dose. The differences in FEV between Budesonide-formoterol Easyhaler and Salbutamol pMDI with spacer were -0.163 (-0.225) L after the first and -0.092 (-0.131) L after the last dose.
CONCLUSION
The study confirms non-inferiority of Salbutamol Easyhaler to Ventoline Evohaler with spacer in relieving acute bronchoconstriction, making Easyhaler a sustainable and safe reliever for MC test and supports its use during asthma attacks.
Topics: Humans; Methacholine Chloride; Female; Bronchoconstriction; Male; Adult; Asthma; Middle Aged; Albuterol; Dry Powder Inhalers; Forced Expiratory Volume; Bronchodilator Agents; Young Adult; Administration, Inhalation; Metered Dose Inhalers; Adolescent; Bronchial Provocation Tests; Treatment Outcome; Aged; Inhalation Spacers; Budesonide, Formoterol Fumarate Drug Combination
PubMed: 38851404
DOI: 10.1016/j.rmed.2024.107693 -
Turkish Journal of Medical Sciences 2023Propofol is a positive allosteric modulator of GABAA receptor (GABAAR) and has potent antioxidant activity. The aim of this study was to investigate the effect of...
Propofol mitigates brain injury and oxidative stress, and enhances GABAA receptor α1 subunit expression in a rat model of lithium chloride-pilocarpine induced status epilepticus.
BACKGROUND/AIM
Propofol is a positive allosteric modulator of GABAA receptor (GABAAR) and has potent antioxidant activity. The aim of this study was to investigate the effect of propofol on damage to the cerebral cortex and hippocampus in a lithium chloride (LiCl)-pilocarpine animal model of status epilepticus (SE).
MATERIALS AND METHODS
Adult male Sprague Dawley rats were injected with LiCl-pilocarpine to induce SE. They were then randomized and injected 30 min later with vehicle saline (SE+saline), propofol (SE+PPF, 50 mg/kg), Diazepam (SE+DZP, 10 mg/kg), Scopolamine (SE+SCOP, 10 mg/kg), or MK-801 (SE+MK-801, 2 mg/kg). Another group of rats received saline only and served as the naïve control (BLK). The levels of superoxide dismutase (SOD), glutathione (GSH) and malondialdehyde (MDA) in the serum, cortex and hippocampus were analyzed 2 and 24 h posttreatment. The degree of tissue damage in the cortex and hippocampus of individual rats was assessed 24 h posttreatment, together with expression of the GABAAR α1 subunit.
RESULTS
The propofol group showed reduced levels of tissue damage in the cerebral cortex and hippocampus, decreased levels of MDA, and increased levels of GSH compared to the SE+saline group. No changes in SOD level were observed in serum and tissue samples from the cortex and hippocampus of SE+saline rats. Immunohistochemistry and Western blot assays showed that propofol treatment significantly increased the expression of GABAR α1 subunit in the cortical and hippocampal tissues of SE rats.
CONCLUSION
Propofol treatment protected against SE-induced tissue injury in the cortex and hippocampus of rats. This was due at least in part to its antioxidant activity and to its induction of GABAAR α1 subunit expression in the brain.
Topics: Animals; Propofol; Receptors, GABA-A; Status Epilepticus; Pilocarpine; Male; Rats, Sprague-Dawley; Lithium Chloride; Oxidative Stress; Rats; Disease Models, Animal; Hippocampus; Brain Injuries; Malondialdehyde; Cerebral Cortex
PubMed: 38813010
DOI: 10.55730/1300-0144.5670 -
Ocular Immunology and Inflammation May 2024To report a case of significant postoperative cystoid macular edema (CME) in a patient with no prior history of uveitis or systemic inflammatory disease, in which a...
AIM
To report a case of significant postoperative cystoid macular edema (CME) in a patient with no prior history of uveitis or systemic inflammatory disease, in which a suprachoroidal (SC) triamcinolone acetonide injectable suspension resulted in complete resolution of CME.
DESIGN
Case report.
METHODS
An 81-year-old man presented with a complex, dense brunescent cataract, floppy iris, and miotic pupil in the left eye. Six weeks following cataract extraction, the intraocular lens (IOL) was dislocated completely from the visual axis. He underwent a pars plana vitrectomy and IOL exchange with an anterior chamber IOL due to a three-piece IOL dislocation. Following the operation, the patient began treatment with prednisolone acetate and ketorolac. However, 2 weeks later, he was noted to be a steroid responder and glaucoma suspect. Therefore, the decision was made to taper and discontinue topical steroids. At 6 months postoperatively, ranibizumab was injected for persistent CME. However, following injection, there was intraocular pressure (IOP) elevation and increased CME. IOP improved 1 month later with dorzolamide hydrochloride and timolol maleate. At 8 months post-operation, there was persistent CME. The patient was then treated with an SC triamcinolone acetonide injection. There was complete resolution of CME by 14 weeks later, with improvement in visual acuity. Despite the patient's known steroid response with topical steroids, IOP remained within normal limits during the entire follow-up period after injection.
CONCLUSION
SC triamcinolone acetonide injection is indicated for macular edema associated with uveitis; however, treatment for postoperative macular edema with this novel suprachoroidal injection may be considered.
PubMed: 38781576
DOI: 10.1080/09273948.2024.2356723 -
Scientific Reports May 2024We studied the inhibitory actions of docosahexaenoic acid (DHA) on the contractions induced by carbachol (CCh), angiotensin II (Ang II), and bradykinin (BK) in guinea...
We studied the inhibitory actions of docosahexaenoic acid (DHA) on the contractions induced by carbachol (CCh), angiotensin II (Ang II), and bradykinin (BK) in guinea pig (GP) gastric fundus smooth muscle (GFSM), particularly focusing on the possible inhibition of store-operated Ca channels (SOCCs). DHA significantly suppressed the contractions induced by CCh, Ang II, and BK; the inhibition of BK-induced contractions was the strongest. Although all contractions were greatly dependent on external Ca, more than 80% of BK-induced contractions remained even in the presence of verapamil, a voltage-dependent Ca channel inhibitor. BK-induced contractions in the presence of verapamil were not suppressed by LOE-908 (a receptor-operated Ca channel (ROCC) inhibitor) but were suppressed by SKF-96365 (an SOCC and ROCC inhibitor). BK-induced contractions in the presence of verapamil plus LOE-908 were strongly inhibited by DHA. Furthermore, DHA inhibited GFSM contractions induced by cyclopiazonic acid (CPA) in the presence of verapamil plus LOE-908 and inhibited the intracellular Ca increase due to Ca addition in CPA-treated 293T cells. These findings indicate that Ca influx through SOCCs plays a crucial role in BK-induced contraction in GP GFSM and that this inhibition by DHA is a new mechanism by which this fatty acid inhibits GFSM contractions.
Topics: Animals; Guinea Pigs; Docosahexaenoic Acids; Bradykinin; Muscle, Smooth; Carbachol; Muscle Contraction; Angiotensin II; Gastric Fundus; Verapamil; Calcium; Male; Humans; Calcium Channels; HEK293 Cells; Calcium Channel Blockers; Imidazoles
PubMed: 38778154
DOI: 10.1038/s41598-024-62578-y -
Molecular and Cellular Endocrinology Sep 2024High serum estrogen concentrations are associated with asthma development and severity, suggesting a link between estradiol and airway hyperresponsiveness (AHR)....
High serum estrogen concentrations are associated with asthma development and severity, suggesting a link between estradiol and airway hyperresponsiveness (AHR). 17β-estradiol (E2) has non-genomic effects via Ca regulatory mechanisms; however, its effect on the plasma membrane Ca-ATPases (PMCA1 and 4) and sarcoplasmic reticulum Ca-ATPase (SERCA) is unknown. Hence, in the present study, we aim to demonstrate if E2 favors AHR by increasing intracellular Ca concentrations in guinea pig airway smooth muscle (ASM) through a mechanism involving Ca-ATPases. In guinea pig ASM, Ca microfluorometry, muscle contraction, and Western blot were evaluated. Then, we performed molecular docking analysis between the estrogens and Ca ATPases. In tracheal rings, E2 produced AHR to carbachol. In guinea pig myocytes, acute exposure to physiological levels of E2 modified the transient Ca peak induced by caffeine to a Ca plateau. The incubation with PMCA inhibitors (lanthanum and carboxyeosin, CE) partially reversed the E2-induced sustained plateau in the caffeine response. In contrast, cyclopiazonic acid (SERCA inhibitor), U-0126 (an inhibitor of ERK 1/2), and choline chloride did not modify the Ca plateau produced by E2. The mitochondrial uniporter activity and the capacitative Ca entry were unaffected by E2. In guinea pig ASM, Western blot analysis demonstrated PMCA1 and PMCA4 expression. The results from the docking modeling demonstrate that E2 binds to both plasma membrane ATPases. In guinea pig tracheal smooth muscle, inhibiting the PMCA with CE, induced hyperresponsiveness to carbachol. 17β-estradiol produces hyperresponsiveness by inhibiting the PMCA in the ASM and could be one of the mechanisms responsible for the increase in asthmatic crisis in women.
Topics: Animals; Guinea Pigs; Estradiol; Plasma Membrane Calcium-Transporting ATPases; Molecular Docking Simulation; Calcium; Muscle, Smooth; Sarcoplasmic Reticulum Calcium-Transporting ATPases; Male; Trachea; Muscle Contraction; Respiratory Hypersensitivity; Cell Membrane; Carbachol; Myocytes, Smooth Muscle
PubMed: 38763427
DOI: 10.1016/j.mce.2024.112273 -
Crack cocaine inhalation increases seizure susceptibility by reducing acetylcholinesterase activity.Epilepsy & Behavior : E&B Jul 2024Crack cocaine is a highly addictive and potent stimulant drug. Animal studies have shown that the cholinergic system plays a role in neurotoxicity induced by cocaine or...
Crack cocaine is a highly addictive and potent stimulant drug. Animal studies have shown that the cholinergic system plays a role in neurotoxicity induced by cocaine or its active metabolites inhalation. Behavioral alterations associated with crack cocaine use include hyperactivity, depressed mood, and decreased seizure threshold. Here we evaluate the acetylcholinesterase (AChE) and reactive oxygen species (ROS) activity, behavioral profile, and the threshold for epileptic seizures in rats that received intrahippocampal pilocarpine (H-PILO) followed by exposure to crack cocaine (H-PILO + CRACK). Animals exposed to H-PILO + CRACK demonstrated increased severity and frequency of limbic seizures. The AChE activity was reduced in the groups exposed to crack cocaine alone (CRACK) and H-PILO + CRACK, whereas levels of ROS remained unchanged. In addition, crack cocaine exposure increased vertical locomotor activity, without changing water and sucrose intake. Short-term memory consolidation remained unchanged after H-PILO, H-PILO + CRACK, and CRACK administration. Overall, our data suggest that crack cocaine inhalation reduced the threshold for epileptic seizures in rats submitted to low doses of pilocarpine through the inhibition of AChE. Taken together, our findings can be useful in the development of effective strategies for preventing and treating the harmful effects of cocaine and crack cocaine on the central nervous system.
Topics: Animals; Male; Crack Cocaine; Acetylcholinesterase; Rats; Pilocarpine; Seizures; Rats, Wistar; Administration, Inhalation; Disease Models, Animal; Reactive Oxygen Species; Motor Activity; Hippocampus
PubMed: 38761450
DOI: 10.1016/j.yebeh.2024.109832 -
Biomedical Physics & Engineering Express Jun 2024Detection of the epileptogenic zone is critical, especially for patients with drug-resistant epilepsy. Accurately mapping cortical regions exhibiting high activity...
Detection of the epileptogenic zone is critical, especially for patients with drug-resistant epilepsy. Accurately mapping cortical regions exhibiting high activity during spontaneous seizure events while detecting neural activity up to 500 Hz can assist clinicians' surgical decisions and improve patient outcomes.We designed, fabricated, and tested a novel hybrid, multi-scale micro-electrocorticography (micro-ECoG) array with a unique embedded configuration. This array was compared to a commercially available microelectrode array (Neuronexus) for recording neural activity in rodent sensory cortex elicited by somatosensory evoked potentials and pilocarpine-induced seizures.Evoked potentials and spatial maps recorded by the multi-scale array ('micros', 'mesos', and 'macros' refering to the relative electrode sizes, 40 micron, 1 mm, and 4 mm respectively) were comparable to the Neuronexus array. The SSEPs recorded with the micros had higher peak amplitudes and greater signal power than those recorded by the larger mesos and macro. Seizure onset events and high-frequency oscillations (∼450 Hz) were detected on the multi-scale, similar to the commercially available array. The micros had greater SNR than the mesos and macro over the 5-1000 Hz frequency range during seizure monitoring. During cortical stimulation experimentation, the mesos successfully elicited motor effects.Previous studies have compared macro- and microelectrodes for localizing seizure activity in adjacent regions. The multi-scale design validated here is the first to simultaneously measure macro- and microelectrode signals from the same overlapping cortical area. This enables direct comparison of microelectrode recordings to the macroelectrode recordings used in standard neurosurgical practice. Previous studies have also shown that cortical regions generating high-frequency oscillations are at an increased risk for becoming epileptogenic zones. More accurate mapping of these micro seizures may improve surgical outcomes for epilepsy patients.
Topics: Microelectrodes; Electrocorticography; Animals; Seizures; Rats; Evoked Potentials, Somatosensory; Male; Electrodes, Implanted; Somatosensory Cortex; Equipment Design; Rats, Sprague-Dawley; Brain Mapping; Pilocarpine; Epilepsy
PubMed: 38744259
DOI: 10.1088/2057-1976/ad4b1c