Search

Nitazoxanide (NTZ) is an effective antiparasitic drug with potent antiviral and antimicrobial activity. This randomized, open‐label, 2‐sequence, 2‐period crossover trial was designed to evaluate the bioequivalence (BE) of the NTZ dry suspension in healthy subjects and investigated the effect of food intake on the pharmacokinetic (PK) properties of tizoxanide (an active metabolite of NTZ, TIZ). Sixty healthy Chinese subjects were enrolled and received a single dose of 500 mg/25 mL of preparations on days 1 and 4 under overnight fasting or fed conditions, respectively. The plasma concentration of TIZ was determined using high‐performance liquid chromatography/tandem mass spectrometry. PK parameters were calculated using WinNonlin 8.2 and BE was evaluated using SAS 9.4. The 90% confidence intervals for the geometric mean ratio (test/reference) of maximum concentration (Cmax), the area under the curve from time 0 to the time of the last quantifiable concentration (AUC0‐t), and the area under the curve from time 0 to extrapolation to infinity (AUC0‐∞) were all within the equivalent interval of 80%‐125%, compliant with BE requirements. In comparison with fasting, on taking the reference and test preparations of the NTZ dry suspension after a meal, the AUC0‐t increased by 48.9% and 47.3%, respectively, the AUC0‐∞ increased by 48.4% and 48.3%, respectively, and the post‐meal Tmax was prolonged by 1.8‐2 hours. Our results demonstrate that the test and reference preparations were bioequivalent. High‐fat meals significantly improve the degree of drug absorption and delay the rate of drug absorption. [ABSTRACT FROM AUTHOR]

In this study, an ultra‐performance liquid chromatography–tandem mass spectrometry method was established for the development and validation of baloxavir acid (BXA) concentrations and the active ingredients of the antiviral drug baloxavir marboxil (BXM). Further, the method was applied to study the pharmacokinetics of BXA. BXA was determined by the electrospray ionization multiple reaction monitoring positive ion mode, and the mass‐to‐charge ratios (m/z) of BXA and internal standard baloxavir‐d4 were 484.2 → 247.2 and 488.1 → 247.2. An Oasis max online column (2.1 × 20 mm, 30 μm) was used with 1% formic acid in water (A) and 2% formic acid in acetonitrile (B) as mobile phases at a flow rate of 0.5 mL·min−1 for chromatographic separation. The linearity was good in the range of 3–200 ng·mL−1 (r = 0.9994), with 3.00 ng·mL−1 lower limit of quantification. The relative standard deviation of the inter‐assay precision was less than or equal to 6.51%, and the accuracy was in the range of 91.28%–104.29%. This method is suitable for the determination of BXA and for performing pharmacokinetic studies in clinical research. [ABSTRACT FROM AUTHOR]

Background: Janagliflozin is a novel sodium–glucose cotransport-2 inhibitor. Despite its remarkable effect in glycemic control, no systematic research has evaluated the effect of renal impairment (RI) on its pharmacokinetics and pharmacodynamics. Methods: Here, patients with T2DM (n = 30) were divided into normal renal function (eGFR ≥ 90 mL/min/1.73 m2), mild RI (eGFR between 60 and 89 mL/min/1.73 m2), moderate RI-I (eGFR between 45 and 59 mL/min/1.73 m2), and moderate RI-II (eGFR between 30 and 44 mL/min/1.73 m2) groups. They were administered 50 mg janagliflozin orally, and plasma and urine samples were collected for the determination of janagliflozin concentration. Results: Following oral administration, janagliflozin was rapidly absorbed, with the time to Cmax of 2–6 h for janagliflozin and 3–6 h for its metabolite XZP-5185. Plasma exposure levels were similar for janagliflozin in T2DM patients with or without RI but decreased for the metabolite XZP-5185 in T2DM patients with eGFR between 45 and 89 mL/min/1.73 m2. Janagliflozin significantly promoted the excretion of urinary glucose, even in patients with reduced eGFR. Janagliflozin was well tolerated in patients with T2DM with or without RI, and no serious adverse events (SAEs) occurred during this trial. Conclusions: The exposure levels of janagliflozin in T2DM patients were slightly increased with worsening of RI (i.e., 11% increase in the AUC in patients with moderate RI compared with the normal renal function group). Despite worsening of renal function, janagliflozin exerted a significant pharmacologic effect and was well tolerated, even in patients with moderate RI, implying a promising role in the treatment of patients with in T2DM. Registration: China Drug Trial register (http://www.chinadrugtrials.org.cn/I) identifier no.: CTR20192721. [ABSTRACT FROM AUTHOR]

What Is Known and Objective. Pyrotinib maleate, also known as pyrotinib, is an irreversible dual receptor tyrosine kinase inhibitor that primarily targets the epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2). Cytochrome P450 3A4 (CYP3A4) enzyme mainly catalyzes pyrotinib, and its metabolism is influenced apparently by CYP3A4 strong inhibitor, but the effect of CYP3A4 moderate inhibitor is still unclear as a moderate inhibitor of CYP3A4 enzyme. This study evaluated the effect of fluconazole, a widespread antifungal medication, on the pharmacokinetics and safety tolerance of pyrotinib. Methods. This study was an open, single-dose, and self-controlled clinical trial. Eighteen healthy Chinese participants were enrolled in this study. All participants were administered fluconazole on days 6–18 and pyrotinib on days 1 and 9. The maximum plasma concentration (Cmax), time to Cmax (Tmax), area under the concentration–time curve from time 0 to the last measurable concentration (AUC0−t), area under the concentration–time curve from time 0 extrapolated to infinity (AUC0−∞), terminal elimination half-life (t1/2), apparent volume of distribution (Vz/F), and apparent clearance (CL/F) were calculated using WinNonlin software (version 8.1). Safety tolerance was assessed throughout the process. Results and Discussion. Compared with the single administration of pyrotinib, the exposure level was enhanced significantly after the coadministration of pyrotinib and fluconazole. The geometric mean ratios (pyrotinib + fluconazole/pyrotinib alone) of Cmax, AUC0−t, and AUC0−∞ were 2.16, 3.6, and 3.5, respectively. The parameter of t1/2 is 14.16 h and 24.03 h, and CL/F is 275.06 L/h and 78.42 L/h, for pyrotinib alone and with fluconazole. No serious adverse events were reported in this trial, and no participant withdrew from the trial because of adverse events. What Is New and Conclusion. The PK profile of pyrotinib, a CYP3A4 substrate, was significantly influenced by fluconazole, with increased exposure levels and prolonged t1/2. Dosage adjustment is suggested for the clinical application of pyrotinib when coadministered with fluconazole or other CYP3A4 inhibitors/inducers. [ABSTRACT FROM AUTHOR]

Famitinib is a tyrosine kinase inhibitor under clinical investigation for the treatment of solid tumors. Here, a 3‐period crossover trial investigated the effect of high‐fat or low‐fat food intake on the single‐dose pharmacokinetic properties of oral famitinib. Twenty‐four healthy Chinese participants were enrolled and received a single 25‐mg dose of famitinib malate capsule following a high‐fat or low‐fat breakfast before dosing. Blood samples were collected before dosing (0 hour) to 192 hours after dosing, and famitinib concentrations in plasma were determined with validated liquid chromatography–tandem mass spectrometry. Compared with the fasting condition, the geometric mean ratios for low‐fat/fasting were 98.6%, 107.7%, and 107.5% for maximum plasma concentration, area under the plasma concentration–time curve (AUC) over the dosing interval, and AUC from time 0 to infinity, respectively. Those for high‐fat/fasting were 84.4%, 105.0%, and 105.1% for maximum plasma concentration, AUC over the dosing interval, and AUC from time 0 to infinity, respectively. There was no significant difference in adverse events between fasting and fed conditions, and no serious adverse events occurred during the trial. In conclusion, oral famitinib bioavailability is not affected by food intake, implying that patients with cancer do not need to consider dietary status when using famitinib. This is considered important for convenience and treatment compliance. [ABSTRACT FROM AUTHOR]

Macrophages are important effector cells in tumor progression and immune regulation. Previously, we demonstrated that the transcription suppressor homeobox containing 1(HMBOX1) exhibits immunosuppressive activity in LPS-induced acute liver injury by impeding macrophage infiltration and activation. We also observed a lower proliferation in HMBOX1-overexpressed RAW264.7 cells. However, the specific mechanism was unclear. Here, a work was performed to characterize HMBOX1 function related to cell proliferation from a metabolomics standpoint by comparing the metabolic profiles of HMBOX1-overexpressed RAW264.7 cells to those of the controls. Firstly, we assessed HMBOX1 anti-proliferation activity in RAW264.7 cells with CCK8 assay and clone formation. Then, we performed metabolomic analyses by ultra-liquid chromatography coupled with mass spectrometry to explore the potential mechanisms. Our results indicated that HMBOX1 inhibited the macrophage growth curve and clone formation ability. Metabolomic analyses showed significant changes in HMBOX1-overexpressed RAW264.7 metabolites. A total of 1312 metabolites were detected, and 185 differential metabolites were identified based on the criterion of OPLS-DA VIP > 1 and p value < 0.05. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that the elevated HMBOX1 in RAW264.7 inhibited the pathways of amino acid and nucleotide metabolism. Glutamine concentrations decreased significantly in HMBOX1-overexpressed macrophages, and glutamine-related transporter SLC1A5 was also downregulated. Furthermore, SLC1A5 overexpression reversed HMBOX1 inhibition of macrophage proliferation. This study demonstrated the potential mechanism of the HMBOX1/SLC1A5 pathway in cell proliferation by regulating glutamine transportation. The results may help provide a new direction for therapeutic interventions in macrophage-related inflammatory diseases. [ABSTRACT FROM AUTHOR]

Recent breakthrough experiments revealed the iso-reticular Zr-MOFs, MIL-140B and MIL-140C, as promising sorbents for the separation of C6 isomers. Interestingly while the ultra-small pore MIL-140B exhibited hexane isomer sorption hierarchy according to the normal boiling point order (n-C6 > 3MP (3-methyl pentane)), an uncommon shift in the elution order was observed in the larger pore MIL-140C. It was only speculated that the flexibility of the MOFs might be the origin of this intriguing behavior. Herein, flexible force field hybrid osmotic Monte Carlo combined with molecular dynamics simulations were carried out to unravel the microscopic mechanism of the adsorption and dynamics of both C6 isomers in MIL140B and MIL140C. Thermodynamically preferred adsorption of n-C6 over 3MP was predicted for MIL-140B and to a slightly less extent for MIL-140C. Interestingly while the mobility of n-C6 was found to remain higher than that of 3MP in the whole range of loading for MIL-140B, 3MP becomes more mobile than n-C6 at saturation in MIL-140C. This suggests that this kinetics order is most probably the origin of the inversion of the elution order observed experimentally for MIL-140C. The translational and rotational dynamics of the two guests in MIL-140B and MIL-140C was further understood in-depth. [ABSTRACT FROM AUTHOR]

Insufficient remyelination due to impaired oligodendrocyte precursor cell (OPC) differentiation and maturation is strongly associated with irreversible white matter injury (WMI) and neurological deficits. We analyzed whole transcriptome expression to elucidate the potential role and underlying mechanism of action of lipocalin-2 (LCN2) in OPC differentiation and WMI and identified the receptor SCL22A17 and downstream transcription factor early growth response protein 1 (EGR1) as the key signals contributing to LCN2-mediated insufficient OPC remyelination. In LCN-knockdown and OPC EGR1 conditional-knockout mice, we discovered enhanced OPC differentiation in developing and injured white matter (WM); consistent with this, the specific inactivation of LCN2/SCl22A17/EGR1 signaling promoted remyelination and neurological recovery in both atypical, acute WMI due to subarachnoid hemorrhage and typical, chronic WMI due to multiple sclerosis. This potentially represents a novel strategy to enhance differentiation and remyelination in patients with white matter injury. [ABSTRACT FROM AUTHOR]

Background: No effective therapeutic agents for calcific aortic valve disease (CAVD) are available currently. Dietary supplementation has been proposed as a novel treatment modality for various diseases. As a flavanone, hesperetin is widely abundant in citrus fruits and has been proven to exert protective effects in multiple diseases. However, the role of hesperetin in CAVD remains unclear. Methods: Human aortic valve interstitial cells (VICs) were isolated from aortic valve leaflets. A mouse model of aortic valve stenosis was constructed by direct wire injury (DWI). Immunoblotting, immunofluorescence staining, and flow cytometry were used to investigate the roles of sirtuin 7 (Sirt7) and nuclear factor erythroid 2-related factor 2 (Nrf2) in hesperetin-mediated protective effects in VICs. Results: Hesperetin supplementation protected the mice from wire-injury-induced aortic valve stenosis; in vitro, hesperetin inhibited the lipopolysaccharide (LPS)-induced activation of NF-κB inflammatory cytokine secretion and osteogenic factors expression, reduced ROS production and apoptosis, and abrogated LPS-mediated injury to the mitochondrial membrane potential and the decline in the antioxidant levels in VICs. These benefits of hesperetin may have been obtained by activating Nrf2–ARE signaling, which corrected the dysfunctional mitochondria. Furthermore, we found that hesperetin could directly bind to Sirt7 and that the silencing of Sirt7 decreased the effects of hesperetin in VICs and potently abolished the ability of hesperetin to increase Nrf2 transcriptional activation. Conclusions: Our work demonstrates that hesperetin plays protective roles in the aortic valve through the Sirt7–Nrf2–ARE axis; thus, hesperetin might be a potential dietary supplement that could prevent the development of CAVD. [ABSTRACT FROM AUTHOR]

In this work, the relationship between the water flux through nanoporous two-dimensional hexagonal Boron Nitride (h-BN) and surface tension was investigated from equilibrium and pressure-driven molecular dynamics simulations by considering the most popular rigid water models. From the surface tension calculation, the contact angle was evaluated and compared with the experiment. We exhibit a correlation between the water flux through nanoporous h-BN predicted by the various water models and the surface tension as a result of the difference in the interfacial energy. [ABSTRACT FROM AUTHOR]

The dynamic hysteresis scaling behaviors of a [001]c poled Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 (PMN-0.28PT) single crystal have been explored as a function of amplitude E0 and frequency f of the external electric field in a temperature region from 298 K to 388 K. The various scaling properties for hysteresis parameters such as area , coercive field Ec, saturation polarization Ps vs temperature T, amplitude E0 and frequency f were characterized among different temperature region. It was discovered that temperature has a critical influence on the polarization dynamic hysteresis and phase transformation characteristics of the PMN-0.28PT single crystal, and especially it was noticed that the discrepancy of the scaling relation between ln and lnE0 in low-field and high-field ranges decreases with increasing temperature. Meanwhile, the slope k in the linear equation ln = klnE0 + b increases while intercept b decreases with T in the temperature region of rhombohedral or tetragonal phase. In addition, temperature has a significant effect on the exponent α in the power law ∝ f α and the appearance of peak value in the relation between ln and lnf can be mainly contributed to the frequency dependence of Ec. [ABSTRACT FROM AUTHOR]

What is known and objective: Nalbuphine is a mu (μ) receptor partial antagonist/kappa (κ) receptor agonist analgesic and can be administered as a single injection or using patient‐controlled analgesia (PCA) in the clinical setting. However, differences in the pharmacokinetics of the two administration methods are unclear. Here, a clinical trial was performed to compare the pharmacokinetic characteristics and superiority of nalbuphine with a single‐injection or PCA‐mimic method to provide a reference for the selection of an appropriate administration method. Methods: Twenty healthy individuals were divided into two groups and injected with 10 mg nalbuphine intravenously using a single‐injection or a PCA‐mimic method (2 mg once for five times with a 30‐min interval). Blood samples were collected, and safety was investigated. The liquid chromatography‐tandem mass spectrometry was adopted to determine the concentration of nalbuphine in plasma. Results and discussion: The maximum concentration (Cmax) and area under concentration‐time curve (AUC0‐t) values of nalbuphine in the single‐injection and PCA groups were as follows: Cmax, 81.3 ± 24.7 and 39.8 ± 6.4 ng/ml, respectively; moreover, AUC0‐t, 110.3 ± 19.5 and 128.3 ± 23.0 h ng/ml, respectively. The effective analgesic concentration durations (EACDs) for the two administration methods were 1.39 ± 0.64 and 1.96 ± 0.91 h, respectively. Nalbuphine was well tolerated, and improvements were observed in the PCA group. What is new and conclusion: Compared with those in the single‐injection group, the AUC0‐t and EACDs in the PCA group were similar, whereas Cmax was decreased significantly. Therefore, the PCA method was more suitable for the clinical application of nalbuphine injection owing to the superiority of lower concentration fluctuation and the improved safety profile. [ABSTRACT FROM AUTHOR]

A series of isoreticular Zr carboxylate MOFs, MIL-140A, B and C, exhibiting 1D microporous triangular shaped channels and based on different aromatic dicarboxylate ligands (1,4-BDC, 2,6-NDC and 4,4′-BPDC, respectively), were investigated by chromatographic breakthrough experiments regarding their ability to separate hexane isomers (nC6/2MP/3MP/23DMB/22DMB). Both single and equimolar multicomponent experiments were performed at the temperatures 343, 373, and 423 K and a total hydrocarbon pressure up to 50.0 kPa using the MIL-140B form. The elution order is similar to that of the normal boiling point of the compounds nC6 > 2MP > 3MP > 23DMB > 22DMB. It is noteworthy that this material enables separation of the hexane isomers by class, linear > mono-branched > di-branched, with a selectivity (linear + mono-branched isomers/di-branched isomers) up to 10 at 343 K, decreasing, however, as the temperature increases. Grand canonical Monte Carlo simulations were further performed to gain insight into the adsorption/separation mechanisms, highlighting the crucial need to consider a tiny tilting of the organic linkers for capturing the experimental observations. The impact of the pore size was finally assessed through the comparison with MIL-140A and MIL-140C, respectively, based on multicomponent experiments at 343 K. We evidenced a significant decrease of the selectivity (about 2) in both cases while the loadings were decreased or increased for MIL-140A and MIL-140C, respectively. Additionally, MIL-140C was demonstrated to exhibit an uncommon shift in the elution order occurring between nC6 and 3MP, 3MP being the last compound to saturate in the column. [ABSTRACT FROM AUTHOR]

Objective: The potential roles and mechanisms of pericytes in maintaining blood-brain barrier (BBB) integrity, which would be helpful for the development of therapeutic strategies for subarachnoid hemorrhage (SAH), remain unclear. We sought to provide evidence on the potential role of pericytes in BBB disruption and possible involvement and mechanism of CypA signaling in both cultured pericytes and SAH models.Methods: Three hundred fifty-three adult male C57B6J mice weighing 22 to 30 g, 29 CypA-/- mice, 30 CypA+/+ (flox/flox) mice, and 30 male neonatal C57B6J mice were used to investigate the time course of CypA expression in pericytes after SAH, the intrinsic function and mechanism of CypA in pericytes, and whether the known receptor CD147 mediates these effects.Results: Our data demonstrated both intracellular CypA and CypA secretion increased after SAH and could activate CD147 receptor and downstream NF-κB pathway to induce MMP9 expression and proteolytic functions for degradation of endothelium tight junction proteins and basal membranes. CypA served as autocrine or paracrine ligand for its receptor, CD147. Although CypA could be endocytosed by pericytes, specific endocytosis inhibitor chlorpromazine did not have any effect on MMP9 activation. However, specific knockdown of CD147 could reverse the harmful effects of CypA expression in pericytes on the BBB integrity after SAH.Conclusions: This study demonstrated for the first time that CypA mediated the harmful effects of pericytes on BBB disruption after SAH, which potentially mediated by CD147/NF-κB/MMP9 signal, and junction protein degradation in the brain. By targeting CypA and pericytes, this study may provide new insights on the management of SAH patients. [ABSTRACT FROM AUTHOR]

Background. Mammalian sterile 20-like kinase 1 (MST1), the key component of the Hippo-YAP pathway, exhibits an important role in the pathophysiological process of various neurological disorders, including ischemic stroke and spinal cord injury. However, during subarachnoid hemorrhage, the involvement of MST1 in the pathophysiology of early brain injury remains unknown. Methods. We employed intravascular filament perforation to establish the subarachnoid hemorrhage (SAH) mouse model. The MST1 inhibitor XMU-MP-1 was intraperitoneally injected at 1 h after SAH, followed by daily injections. MST1 in vivo knockdown was performed 3 weeks prior to SAH via intracerebroventricular injection of adeno-associated virus (AAV) packaged with MST1 shRNA. The SAH grade, behavioral deficits, TUNEL staining, Evans blue dye extravasation and fluorescence, brain water content, protein and cytokine expressions by Western blotting, immunofluorescence, and proteome cytokine array were evaluated. Results. Following SAH, the phosphorylation level of MST1 was upregulated at 12 h, with a peak at 72 h after SAH. It was colocalized with the microglial marker Iba1. Both XMU-MP-1 and MST1 shRNA alleviated the neurological deficits, blood-brain barrier (BBB) disruption, brain edema, neuroinflammation, and white matter injury, which were induced by SAH in association with nuclear factor- (NF-) κB p65 and matrix metallopeptidase-9 (MMP-9) activation and downregulated endothelial junction protein expression. Conclusions. The current findings indicate that MST1 participates in SAH-induced BBB disruption and white matter fiber damage via the downstream NF-κB-MMP-9 signaling pathway. Therefore, MST1 antagonists may serve as a novel therapeutic target to prevent early brain injury in SAH patients. [ABSTRACT FROM AUTHOR]

Progressive white matter (WM) impairments caused by subarachnoid hemorrhage (SAH) contribute to cognitive deficits and poor clinical prognoses; however, their pathogenetic mechanisms are poorly understood. We investigated the role of nexilin and oligodendrocyte progenitor cell (OPC)-mediated repair in a mouse model of experimental SAH generated via left endovascular perforation. Nexilin expression was enhanced by the elevated migration of OPCs after SAH. Knocking down nexilin by siRNA reduced OPC migration both in vitro and in vivo and abridged WM repair. In contrast, the protease-activated receptor 1 (PAR1), Ras-proximate-1 (RAP1) and phosphorylated RAP1 (pRAP1) levels in WM were elevated after SAH. The genetic inhibition of PAR1 reduced RAP1 and pRAP1 expression, further enhancing nexilin expression. When delivered at an early stage at a concentration of 25 μg/kg, thrombin receptor antagonist peptide along with PAR1 knockdown rescued the down-regulation of myelin basic protein and improved remyelination at the later stage of SAH. Our results suggest that nexilin is required for OPC migration and remyelination following SAH, as it negatively regulates PAR1/RAP1 signaling, thus providing a promising therapeutic target in WM repair and functional recovery. [ABSTRACT FROM AUTHOR]

Intracerebral hemorrhage (ICH) initiates a neuroinflammatory cascade that contributes to substantial neuronal damage and neurological deterioration. Taurine, an abundant amino acid in the nervous system, is reported to reduce inflammatory injury in various central nervous system diseases, but its role and the possible underlying mechanisms in the pathology following ICH remains unclear. This study was designed to evaluate the effect of taurine supplementation on neurological deficits, acute inflammatory responses and white matter injury in a model of ICH in rats. Adult male Sprague-Dawley (SD) rats subjected to collagenase-induced ICH injury were injected intravenously with different concentrations of taurine or vehicle 10 min after ICH and subsequently daily for 3 days. Behavioral studies, brain water content, and assessments of hemorrhagic lesion volume were quantified at day 1 and day 3 post-ICH. Neuronal damage, peri-hematomal inflammatory responses, and white matter injury were determined at 24 h, meanwhile, the content of hydrogen sulfide (H2S) along with the expression of cystathionine-β-synthase (CBS) and P2X7 receptor (P2X7R) in peri-hematomal tissues was analyzed to investigate the possible anti-inflammatory mechanism of taurine. Treatment with a high dosage of taurine (50 mg/kg) significantly attenuated functional deficits and reduced brain edema and hemorrhagic lesion volume after ICH. Taurine administration also resulted in significant amelioration of neuronal damage and white matter injury. These changes were associated with marked reductions in neutrophil infiltration, glial activation, and expression levels of inflammatory mediators. Moreover, the anti-inflammatory effect of taurine was accompanied by increased H2S content, enhanced CBS expression, and less expression of P2X7R. Our study demonstrated that the high dosage of taurine supplementation effectively mitigated the severity of pathological inflammation and white matter injury after ICH, and the mechanism may be related to upregulation of H2S content and reduced P2X7R expression. [ABSTRACT FROM AUTHOR]

Blood--brain barrier (BBB) disruption and subsequent brain edema play important roles in the secondary neuronal death and neurological dysfunction that are observed following intracerebral hemorrhage (ICH). In previous studies, transient receptor potential vanilloid 4 (TRPV4), a calcium-permeable mechanosensitive channel, was shown to induce cytotoxicity in many types of cells and to play a role in orchestrating barrier functions. In the present study, we explored the role of TRPV4 in ICH-induced brain injury, specifically investigating its effect on BBB disruption. Autologous arterial blood was injected into the basal ganglia of rats to mimic ICH. Adult male Sprague Dawley rats were randomly assigned to sham and experimental groups for studies on the time course of TRPV4 expression after ICH. The selective TRPV4 antagonist HC- 067047 and TRPV4 siRNA were administered to evaluate the effects of TRPV4 inhibition. GSK1016790A, a TRPV4 agonist, was administered to naive rats to verify the involvement of TRPV4-induced BBB disruption. A PKC inhibitor, dihydrochloride (H7), and a selective RhoA inhibitor, C3 transferase, were administered to clarify the involvement of the PKCa/RhoA/MLC2 pathway following ICH. Post-ICH assessments including functional tests, brain edema measurements, Evans blue extravasation, western blotting and immunohistochemical assays were performed. TRPV4 inhibition remarkably ameliorated neurological symptoms, brain edema, and neuronal death, as well as BBB disruption, 24--72 h following ICH. Meanwhile, TRPV4 blockade preserved the expression of adherens and tight junction proteins, as well as BBB integrity, by inhibiting stress fiber formation, which might be correlated with the regulation of components of the PKCa/RhoA/MLC2 pathway. Furthermore, adherens and tight junction protein degradation induced by GSK1016790A treatment in naive rats was also related to PKCa/RhoA/MLC2-pathway-mediated stress fiber formation. Based on these findings, therapeutic interventions targeting TRPV4 may represent a novel approach to ameliorate secondary brain injury following ICH. [ABSTRACT FROM AUTHOR]

Localized magnetic fields (MFs) could easily penetrate the scalp, skull, and meninges, thus inducing an electrical current in both the central and peripheral nervous systems, which is primarily used in transcranial magnetic stimulation (TMS) for inducing specific effects on different regions or cells that play roles in various brain activities. Studies of repetitive transcranial magnetic stimulation (rTMS) have led to novel attractive therapeutic approaches. Neural stem cells (NSCs) in adult human brain are able to self-renew and possess multidifferential ability to maintain homeostasis and repair damage after acute central nervous system. In the present review, we summarized the electrical activity of NSCs and the fundamental mechanism of electromagnetic fields and their effects on regulating NSC proliferation, differentiation, migration, and maturation. Although it was authorized for the rTMS use in resistant depression patients by US FDA, there are still unveiling mechanism and limitations for rTMS in clinical applications of acute central nervous system injury, especially on NSC regulation as a rehabilitation strategy. More in-depth studies should be performed to provide detailed parameters and mechanisms of rTMS in further studies, making it a powerful tool to treat people who are surviving with acute central nervous system injuries. [ABSTRACT FROM AUTHOR]

Background: Emerging studies have demonstrated the important physiological and pathophysiological roles of hydrogen sulphide (H2S) as a gasotransmitter for NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome-associated neuroinflammation in the central nervous system. However, the effects of H2S on neuroinflammation after intracerebral haemorrhage (ICH), especially on the NLRP3 inflammasome, remain unknown.Methods: We employed a Sprague-Dawley rat of collagenase-induced ICH in the present study. The time course of H2S content and the spatial expression of cystathionine-β-synthase (CBS) after ICH, the effects of endogenous and exogenous H2S after ICH, the effects of endogenous and exogenous H2S on NLRP3 inflammasome activation under P2X7 receptor (P2X7R) overexpression after ICH, and the involvement of the P2X7R in the mechanism by which microglia-derived H2S prevented NLRP3 inflammasome activation were investigated.Results: We found ICH induced significant downregulation of endogenous H2S production in the brain, which may be the result of decreasing in CBS, the predominant cerebral H2S-generating enzyme. Administration of S-adenosyl-L-methionine (SAM), a CBS-specific agonist, or sodium hydrosulfide (NaHS), a classical exogenous H2S donor, not only restored brain and plasma H2S content but also attenuated brain oedema, microglial accumulation and neurological deficits at 1 day post-ICH by inhibiting the P2X7R/NLRP3 inflammasome cascade. Endogenous H2S production, which was derived mainly by microglia and above treatments, was verified by adenovirus-overexpressed P2X7R and in vitro primary microglia studies.Conclusions: These results indicated endogenous H2S synthesis was impaired after ICH, which plays a pivotal role in the P2X7R/NLRP3 inflammasome-associated neuroinflammatory response in the pathogenesis of secondary brain injury. Maintaining appropriate H2S concentrations in the central nervous system may represent a potential therapeutic strategy for managing post-ICH secondary brain injury and associated neurological deficits. [ABSTRACT FROM AUTHOR]

A robust and sensitive high-performance liquid chromatographic-tandem mass spectrometric (HPLC-MS/MS) assay for the high-throughput quantification of the antihypertensive drug azelnidipine in human plasma was developed and validated following bioanalytical validation guidelines. Azelnidipine and internal standard (IS), telmisartan, were extracted from human plasma by precipitation protein and separated on a C18 column using acetonitrile-methanol-ammonium formate with 0.1% formic acid as mobile phase. Detection was performed on a turbo-spray ionization source (ESI) and mass spectrometric positive multiple reaction monitoring mode (+MRM) using the respective transitions m/ z 583.3 → 167.2 for azelnidipine and m/ z 515.3 → 497.2 for IS. The method has a wide analytical measuring range from 0.0125 to 25 ng/mL. For the lowest limit of quantitation, low, medium and high quality controls, intra- and interassay precisions (relative standard deviation) were 3.30-7.01% and 1.78-8.09%, respectively. The drug was sufficiently stable under all relevant analytical conditions. The main metabolite of azelnidipine, M-1 (aromatized form), was monitored semiquantitatively using the typical transition m/ z 581.3 → 167.2. Finally, the method was successfully applied to a clinical pharmacokinetic study in human after a single oral administration of azelnidipine 8 mg. The assay meets criteria for the analysis of samples from large research trials. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]