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1.
Nitric Oxide ; 147: 1-5, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38547960

RESUMO

Endotoxin tolerance (ET) is the hyporesponsiveness to lipopolysaccharide (LPS) after prior exposure. It is characterized by the downregulation of pro-inflammatory cytokine levels. Although ET protects against inflammation, its abolishment or recovery is critical for immunity. Nitric oxide (NO) plays various roles in the development of ET; however, its specific role in ET recovery remains unknown. To induce ET, RAW264.7 cells (a murine macrophage cell line) were pre-exposed to LPS (LPS1, 100 ng/mL for 24 h) and subsequently re-stimulated with LPS (LPS2, 100 ng/mL for 24 h). Expression of cytokines, NO, nitrite and inducible NO synthase (iNOS) were measured after 0, 12, 24, and 36 h of resting after LPS1 treatment with or without the iNOS-specific inhibitor, 1400W. LPS2-induced tumor necrosis factor-⍺ (TNF-⍺) and interleukin-6 (IL-6) were downregulated after LPS1 treatment, confirming the development of ET. Notably, TNF-⍺ and IL-6 levels spontaneously rebounded after 12-24 h of resting following LPS1 treatment. In contrast, levles of NO, nitrite and iNOS increased during ET development and decreased during ET recovery. Moreover, 1400W inhibited ET development and blocked the early production of NO (<12 h) during ET recovery. Our findings suggest a negative correlation between iNOS-induced NO and cytokine levels in the abolishment of ET.


Assuntos
Lipopolissacarídeos , Óxido Nítrico Sintase Tipo II , Óxido Nítrico , Fator de Necrose Tumoral alfa , Animais , Óxido Nítrico/metabolismo , Camundongos , Lipopolissacarídeos/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Células RAW 264.7 , Interleucina-6/metabolismo , Endotoxinas/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo
2.
Int J Mol Sci ; 25(16)2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39201534

RESUMO

The purpose of this study was to investigate whether and how albiflorin, a natural monoterpene glycoside, affects the release of glutamate, one of the most important neurotransmitters involved in neurotoxicity, from cerebrocortical nerve terminals (synaptosomes) in rats. The results showed that albiflorin reduced 4-aminopyridine (4-AP)-elicited glutamate release from synaptosomes, which was abrogated in the absence of extracellular Ca2+ or in the presence of the vesicular glutamate transporter inhibitor or a P/Q-type Ca2+ channel inhibitor, indicating a mechanism of action involving Ca2+-dependent depression of vesicular exocytotic glutamate release. Albiflorin failed to alter the increase in the fluorescence intensity of 3,3-diethylthiacarbocyanine iodide (DiSC3(5)), a membrane-potential-sensitive dye. In addition, the suppression of protein kinase A (PKA) abolished the effect of albiflorin on glutamate release. Albiflorin also reduced the phosphorylation of PKA and synaptosomal-associated protein of 25 kDa (SNAP-25) and synapsin I at PKA-specific residues, which correlated with decreased available synaptic vesicles. The results of transmission electron microscopy (TEM) also observed that albiflorin reduces the release competence of synaptic vesicles evoked by 4-AP in synaptosomes. In conclusion, by studying synaptosomally released glutamate, we suggested that albiflorin reduces vesicular exocytotic glutamate release by decreasing extracellular Ca2+ entry via P/Q-type Ca2+ channels and reducing PKA-mediated synapsin I and SNAP-25 phosphorylation.


Assuntos
Córtex Cerebral , Proteínas Quinases Dependentes de AMP Cíclico , Ácido Glutâmico , Sinaptossomos , Animais , Ácido Glutâmico/metabolismo , Sinaptossomos/metabolismo , Sinaptossomos/efeitos dos fármacos , Ratos , Córtex Cerebral/metabolismo , Córtex Cerebral/efeitos dos fármacos , Masculino , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Canais de Cálcio Tipo Q/metabolismo , Ratos Sprague-Dawley , Canais de Cálcio Tipo P/metabolismo , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Cálcio/metabolismo , Fosforilação/efeitos dos fármacos , Sinapsinas/metabolismo
3.
Klin Monbl Augenheilkd ; 241(9): 1062-1070, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38688324

RESUMO

This study aims to explore the associations and the underlying mechanism among dry eye disease (DED), air pollution, and meteorological conditions. DED is positively correlated with air pollutants (i.e., PM2.5, PM10, O3, NO2, CO, and SO2) and meteorological conditions (i.e., high altitude and wind speed), while negatively associated with relative humidity. Both low and high air temperatures effect DED. Atmospheric pollutants affect DED mainly through necroptosis or autophagy, inflammatory responses, and oxidative stress. Meteorological factors affect DED not only by their own affects but also by dispersing the concentration of air pollutants, and then reducing the negative exposure. In summary, this review may expand the understanding of the effects of air pollution and meteorological factors on DED and emphasize the importance of air environmental protection.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Síndromes do Olho Seco , Humanos , Poluição do Ar/efeitos adversos , Poluentes Atmosféricos/efeitos adversos , Síndromes do Olho Seco/etiologia , Conceitos Meteorológicos , Exposição Ambiental/efeitos adversos , Estresse Oxidativo , Fatores de Risco , Umidade , Material Particulado/efeitos adversos , Tempo (Meteorologia)
4.
Molecules ; 28(3)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36770979

RESUMO

Inhibiting the excessive release of glutamate in the brain is emerging as a promising therapeutic option and is efficient for treating neurodegenerative disorders. The aim of this study is to investigate the effect and mechanism of plantainoside D (PD), a phenylenthanoid glycoside isolated from Plantago asiatica L., on glutamate release in rat cerebral cortical nerve terminals (synaptosomes). We observed that PD inhibited the potassium channel blocker 4-aminopyridine (4-AP)-evoked release of glutamate and elevated concentration of cytosolic Ca2+. Using bafilomycin A1 to block glutamate uptake into synaptic vesicles and EDTA to chelate extracellular Ca2+, the inhibitory effect of PD on 4-AP-evoked glutamate release was prevented. In contrast, the action of PD on the 4-AP-evoked release of glutamate in the presence of dl-TBOA, a potent nontransportable inhibitor of glutamate transporters, was unaffected. PD does not alter the 4-AP-mediated depolarization of the synaptosomal membrane potential, suggesting that the inhibitory effect of PD on glutamate release is associated with voltage-dependent Ca2+ channels (VDCCs) but not the modulation of plasma membrane potential. Pretreatment with the Ca2+ channel blocker (N-type) ω-conotoxin GVIA abolished the inhibitory effect of PD on the evoked glutamate release, as did pretreatment with the protein kinase C inhibitor GF109203x. However, the PD-mediated inhibition of glutamate release was eliminated by applying the mitochondrial Na+/Ca2+ exchanger inhibitor CGP37157 or dantrolene, which inhibits Ca2+ release through ryanodine receptor channels. These data suggest that PD mediates the inhibition of evoked glutamate release from synaptosomes primarily by reducing the influx of Ca2+ through N-type Ca2+ channels, subsequently reducing the protein kinase C cascade.


Assuntos
4-Aminopiridina , Ácido Glutâmico , Ratos , Animais , Ácido Glutâmico/metabolismo , Ratos Sprague-Dawley , 4-Aminopiridina/farmacologia , Sinaptossomos/metabolismo , Sinalização do Cálcio , Proteína Quinase C/metabolismo , Córtex Cerebral/metabolismo , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia
5.
Klin Monbl Augenheilkd ; 240(2): 163-168, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36100251

RESUMO

BACKGROUND: This retrospective study aimed to evaluate the effect of intense pulsed light treatment (IPL) combined with meibomian gland expression (MGX) in treating meibomian gland dysfunction (MGD) related dry eye disease (DED) for the first time in Northeast China. METHODS: Thirty-one MGD-related dry eye patients were managed by IPL-MGX from October to December 2019 in The First Hospital of Jilin University. Those patients had single IPL-MGX treatment with one follow-up visit, and no topical eye drops used were included in the study. General checkup and data collection helped in determining the age, sex, diagnosis, status of the MG, first noninvasive tear break-up time (1st NIBUT), average NIBUT, the height of tear film, and additional medical history. RESULTS: There was an improvement in the function of the meibomian gland (MG), with a significant decrease in the MG dropouts in the upper eyelid (Rt eye, p = 0.0047; Lt eye, p = 0.0158) and lower eyelid (Rt eye, p = 0.0017; Lt eye, p = 0.0027) plus the average NIBUT (Rt eye, p = 0.0264) also showed improvement after the IPL-MGX treatment. Though no significant difference was reached with the average NIBUT of the Lt eye (p = 0.5256) and the NIBUT grade (Rt eye, p = 0.0578; Lt eye, p = 0.0588), there was an increased duration of the average NIBUT and improved NIBUT grading. The negative results may be because of the maximum severity of DED and the limited treatment times. CONCLUSIONS: The result suggests that IPL-MGX was effective in treating MGD-related DED.


Assuntos
Síndromes do Olho Seco , Disfunção da Glândula Tarsal , Humanos , Disfunção da Glândula Tarsal/metabolismo , Disfunção da Glândula Tarsal/terapia , Estudos Retrospectivos , Glândulas Tarsais/metabolismo , Síndromes do Olho Seco/terapia , Fatores de Tempo , Lágrimas
6.
J Fluoresc ; 32(4): 1601-1610, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35587852

RESUMO

Four fluorimetric probes had been developed to rapidly detect 2,4,6-trinitrophenol (TNP). They were designed and synthesized on the basis of 1,3,4-thiadiazole framework combining calculation with experiment. Among them, SK-1 displayed strong blue emission with fluorescence quantum yield as high as 63.6% in solution. Further evaluation demonstrated that SK-1 displays good selectivity and high sensitivity for rapid and visual detection of TNP. It brought significant changes in both colour and fluorescence emission spectrum. The detection limit was as low as 38 nM. Quenching mechanism was confirmed as photo-induced electron transfer (PET) by nuclear magnetic titration and DFT calculations. What's more, application in real water samples and solid phase paper tests illustrated the practical significance of detection of TNP in both vapor and solution.


Assuntos
Espectrometria de Fluorescência , Teoria da Densidade Funcional , Picratos , Tiadiazóis
7.
J Craniofac Surg ; 33(5): 1300-1302, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36041138

RESUMO

ABSTRACT: To report 2 successfully managed cases of graft rejection with acellular porcine corneal stroma (APCS) transplantation in patients with fungal corneal ulcer. Two patients were diagnosed with fungal corneal ulcer and received APCS transplantation. Graft rejection developed due to the lost follow-up during the period of coronavirus disease 2019 outbreak. Amniotic membranes transplantation and cauterization of neovascularization was performed, respectively. The graft failure resolved successfully after the procedure. To the best of our knowledge, amniotic membranes transplantation and cauterization of new vessels are the firstly reported in treating APCS graft failure. Amniotic membranes transplantation or cauterization of neovascularization appear to be a safe and costeffective method for treating graft failure.


Assuntos
COVID-19 , Transplante de Córnea , Úlcera da Córnea , Animais , Substância Própria/transplante , Transplante de Córnea/métodos , Rejeição de Enxerto , Pandemias , Suínos
8.
Int J Mol Sci ; 23(15)2022 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-35955884

RESUMO

Excessive glutamate release is known to be involved in the pathogenesis of neurological diseases, and suppression of glutamate release from nerve terminals is considered to be a treatment strategy. In this study, we investigated whether isosaponarin, a flavone glycoside isolated from wasabi leaves, could affect glutamate release in rat cerebral cortex nerve terminals (synaptosomes). The release of glutamate was evoked by the K+ channel blocker 4-aminopyridine (4-AP) and measured by an online enzyme-coupled fluorimetric assay. Isosaponarin produced a concentration-dependent inhibition of 4-AP-evoked glutamate release with a half-maximum inhibition of release value of 22 µM. The inhibition caused by isosaponarin was prevented by eliminating extracellular Ca2+ or by using bafilomycin A1, an inhibitor of synaptic vesicle exocytosis. Isosaponarin decreased intrasynaptosomal rises in Ca2+ levels that were induced by 4-AP, without affecting the synaptosomal membrane potential. The isosaponarin-induced inhibition of glutamate release was significantly prevented in synaptosomes that were pretreated with a combination of the calcium channel blockers ω-conotoxin GVIA (N-type) and ω-agatoxin IVA (P/Q-types). The protein kinase C (PKC) pan-inhibitor GF109203X and the Ca2+-dependent PKC inhibitor Go6976 abolished the inhibition of glutamate release by isosaponarin, while the Ca2+-independent PKC inhibitor rottlerin did not show any effect. The results from immunoblotting assays also showed that isosaponarin lowered PKC, PKCα, synaptosomal-associated protein of 25 kDa (SNAP-25), and myristoylated alanine-rich C-kinase substrate (MARCKS) phosphorylation induced by 4-AP. In addition, FM1-43-labeled synaptic vesicles in synaptosomes showed that treatment with isosaponarin resulted in an attenuation of the 4-AP-induced decrease in fluorescence intensity that is consistent with glutamate release. Transmission electron microscopy of synaptosomes also provided evidence that isosaponarin altered the number of synaptic vesicles. These results indicate that isosaponarin suppresses the Ca2+-dependent PKC/SNAP-25 and MARCKS pathways in synaptosomes, causing a decrease in the number of available synaptic vesicles, which inhibits vesicular glutamate release from synaptosomes.


Assuntos
Ácido Glutâmico , Sinaptossomos , Animais , Cálcio/metabolismo , Bloqueadores dos Canais de Cálcio/farmacologia , Córtex Cerebral/metabolismo , Ácido Glutâmico/metabolismo , Potenciais da Membrana , Terminações Nervosas/metabolismo , Ratos , Ratos Sprague-Dawley , Sinaptossomos/metabolismo
9.
Int J Mol Sci ; 23(21)2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36362193

RESUMO

The inhibition of synaptic glutamate release to maintain glutamate homeostasis contributes to the alleviation of neuronal cell injury, and accumulating evidence suggests that natural products can repress glutamate levels and associated excitotoxicity. In this study, we investigated whether eupatilin, a constituent of Artemisia argyi, affected glutamate release in rat cortical nerve terminals (synaptosomes). Additionally, we evaluated the effect of eupatilin in an animal model of kainic acid (KA) excitotoxicity, particularly on the levels of glutamate and N-methyl-D-aspartate (NMDA) receptor subunits (GluN2A and GluN2B). We found that eupatilin decreased depolarization-evoked glutamate release from rat cortical synaptosomes and that this effect was accompanied by a reduction in cytosolic Ca2+ elevation, inhibition of P/Q-type Ca2+ channels, decreased synapsin I Ca2+-dependent phosphorylation and no detectable effect on the membrane potential. In a KA-induced glutamate excitotoxicity rat model, the administration of eupatilin before KA administration prevented neuronal cell degeneration, glutamate elevation, glutamate-generating enzyme glutaminase increase, excitatory amino acid transporter (EAAT) decrease, GluN2A protein decrease and GluN2B protein increase in the rat cortex. Taken together, the results suggest that eupatilin depresses glutamate exocytosis from cerebrocortical synaptosomes by decreasing P/Q-type Ca2+ channels and synapsin I phosphorylation and alleviates glutamate excitotoxicity caused by KA by preventing glutamatergic alterations in the rat cortex. Thus, this study suggests that eupatilin can be considered a potential therapeutic agent in the treatment of brain impairment associated with glutamate excitotoxicity.


Assuntos
Artemisia , Síndromes Neurotóxicas , Ratos , Animais , Ácido Glutâmico/metabolismo , Sinapsinas/metabolismo , Artemisia/metabolismo , 4-Aminopiridina/farmacologia , Ratos Sprague-Dawley , Córtex Cerebral/metabolismo , Cálcio/metabolismo , Sinaptossomos/metabolismo , Exocitose , Ácido Caínico/farmacologia , Síndromes Neurotóxicas/metabolismo
10.
Int J Mol Sci ; 23(8)2022 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-35456948

RESUMO

Current anti-seizure drugs fail to control approximately 30% of epilepsies. Therefore, there is a need to develop more effective anti-seizure drugs, and medicinal plants provide an attractive source for new compounds. This study aimed to evaluate the possible anti-seizure and neuroprotective effects of neferine, an alkaloid from the lotus seed embryos of Nelumbo nucifera, in a kainic acid (KA)-induced seizure rat model and its underlying mechanisms. Rats were intraperitoneally (i.p.) administrated neferine (10 and 50 mg/kg) 30 min before KA injection (15 mg/kg, i.p.). Neferine pretreatment increased seizure latency and reduced seizure scores, prevented glutamate elevation and neuronal loss, and increased presynaptic protein synaptophysin and postsynaptic density protein 95 expression in the hippocampi of rats with KA. Neferine pretreatment also decreased glial cell activation and proinflammatory cytokine (interleukin-1ß, interleukin-6, tumor necrosis factor-α) expression in the hippocampi of rats with KA. In addition, NOD-like receptor 3 (NLRP3) inflammasome, caspase-1, and interleukin-18 expression levels were decreased in the hippocampi of seizure rats pretreated with neferine. These results indicated that neferine reduced seizure severity, exerted neuroprotective effects, and ameliorated neuroinflammation in the hippocampi of KA-treated rats, possibly by inhibiting NLRP3 inflammasome activation and decreasing inflammatory cytokine secretion. Our findings highlight the potential of neferine as a therapeutic option in the treatment of epilepsy.


Assuntos
Alcaloides , Antineoplásicos , Benzilisoquinolinas , Fármacos Neuroprotetores , Alcaloides/farmacologia , Alcaloides/uso terapêutico , Animais , Benzilisoquinolinas/farmacologia , Benzilisoquinolinas/uso terapêutico , Citocinas/metabolismo , Inflamassomos/metabolismo , Ácido Caínico/efeitos adversos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Ratos , Sementes/metabolismo , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico
11.
Int J Mol Sci ; 23(5)2022 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-35269784

RESUMO

The neurotransmitter glutamate plays an essential role in excitatory neurotransmission; however, excessive amounts of glutamate lead to excitotoxicity, which is the most common pathogenic feature of numerous brain disorders. This study aimed to investigate the role of butyl 2-[2-(2-fluorophenyl)acetamido]benzoate (HFP034), a synthesized anthranilate derivative, in the central glutamatergic system. We used rat cerebro-cortical synaptosomes to examine the effect of HFP034 on glutamate release. In addition, we used a rat model of kainic acid (KA)-induced glutamate excitotoxicity to evaluate the neuroprotective potential of HFP034. We showed that HFP034 inhibits 4-aminopyridine (4-AP)-induced glutamate release from synaptosomes, and this inhibition was absent in the absence of extracellular calcium. HFP034-mediated inhibition of glutamate release was associated with decreased 4-AP-evoked Ca2+ level elevation and had no effect on synaptosomal membrane potential. The inhibitory effect of HFP034 on evoked glutamate release was suppressed by blocking P/Q-type Ca2+ channels and protein kinase C (PKC). Furthermore, HFP034 inhibited the phosphorylation of PKC and its substrate, myristoylated alanine-rich C kinase substrate (MARCKS) in synaptosomes. We also observed that HFP034 pretreatment reduced neuronal death, glutamate concentration, glial activation, and the levels of endoplasmic reticulum stress-related proteins, calpains, glucose-regulated protein 78 (GRP 78), C/EBP homologous protein (CHOP), and caspase-12 in the hippocampus of KA-injected rats. We conclude that HFP034 is a neuroprotective agent that prevents glutamate excitotoxicity, and we suggest that this effect involves inhibition of presynaptic glutamate release through the suppression of P/Q-type Ca2+ channels and PKC/MARCKS pathways.


Assuntos
Ácido Glutâmico , Sinaptossomos , 4-Aminopiridina/farmacologia , Animais , Cálcio/metabolismo , Córtex Cerebral/metabolismo , Ácido Glutâmico/metabolismo , Ácido Caínico/farmacologia , Proteína Quinase C/metabolismo , Ratos , Ratos Sprague-Dawley , Sinaptossomos/metabolismo , ortoaminobenzoatos
12.
Molecules ; 27(3)2022 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-35164225

RESUMO

Excessive release of glutamate induces excitotoxicity and causes neuronal damage in several neurodegenerative diseases. Natural products have emerged as potential neuroprotective agents for preventing and treating neurological disorders. Dehydrocorydaline (DHC), an active alkaloid compound isolated from Corydalis yanhusuo, possesses neuroprotective capacity. The present study investigated the effect of DHC on glutamate release using a rat brain cortical synaptosome model. Our results indicate that DHC inhibited 4-aminopyridine (4-AP)-evoked glutamate release and elevated intrasynaptosomal calcium levels. The inhibitory effect of DHC on 4-AP-evoked glutamate release was prevented in the presence of the vesicular transporter inhibitor bafilomycin A1 and the N- and P/Q-type Ca2+ channel blocker ω-conotoxin MVIIC but not the intracellular inhibitor of Ca2+ release dantrolene or the mitochondrial Na+/Ca2+ exchanger inhibitor CGP37157. Moreover, the inhibitory effect of DHC on evoked glutamate release was prevented by the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) inhibitor PD98059. Western blotting data in synaptosomes also showed that DHC significantly decreased the level of ERK1/2 phosphorylation and synaptic vesicle-associated protein synapsin I, the main presynaptic target of ERK. Together, these results suggest that DHC inhibits presynaptic glutamate release from cerebrocortical synaptosomes by suppressing presynaptic voltage-dependent Ca2+ entry and the MAPK/ERK/synapsin I signaling pathway.


Assuntos
Alcaloides/farmacologia , Cálcio/metabolismo , Córtex Cerebral/efeitos dos fármacos , Corydalis/química , Ácido Glutâmico/metabolismo , Tecido Nervoso/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio/química , Córtex Cerebral/metabolismo , Masculino , Tecido Nervoso/metabolismo , Ratos , Ratos Sprague-Dawley
13.
Medicina (Kaunas) ; 58(3)2022 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-35334626

RESUMO

A thyroid storm is an extreme manifestation of thyrotoxicosis, and is life threatening without an early diagnosis. Pregnancy or childbirth may worsen maternal hyperthyroidism or induce the development of a thyroid storm. Gestational hypertension, a disorder defined as new-onset hypertension, develops after 20 weeks of gestation and shares symptoms with a thyroid storm. The diagnosis of a thyroid storm may be challenging in patients with gestational hypertension. To highlight the significance of early thyrotoxicosis-related gastrointestinal symptoms, we report a case of a 38-year-old woman with a twin pregnancy, who was diagnosed with gestational hypertension, and then developed a thyroid storm during the peripartum period. She complained of nausea and abdominal pain, followed by tachycardia, hypertension, and a disturbance of consciousness with desaturation. After emergency caesarean section, fever, diarrhea, and high-output heart failure, with pulmonary edema, were noted during the postoperative period in the intensive care unit. The diagnosis of a thyroid storm was confirmed using the Burch-Wartofsky point scale, which was 75 points. In this patient, the uncommon gastrointestinal symptoms, as initial manifestations of thyrotoxicosis, indicated the development of a thyroid storm. The distinguished presentation of thyrotoxicosis-induced cardiomyopathy and peripartum cardiomyopathy also helped in the differential diagnosis between a thyroid storm and gestational hypertension. Aggressive treatment for thyrotoxicosis should not be delayed because of a missed diagnosis.


Assuntos
Cardiomiopatias , Hipertensão Induzida pela Gravidez , Crise Tireóidea , Tireotoxicose , Adulto , Cardiomiopatias/complicações , Cesárea/efeitos adversos , Feminino , Humanos , Gravidez , Crise Tireóidea/complicações , Crise Tireóidea/diagnóstico , Tireotoxicose/complicações
14.
Chem Res Toxicol ; 34(5): 1286-1295, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-33621091

RESUMO

Glutamate is the major excitatory neurotransmitter in the brain and is involved in many brain functions. In this study, we investigated whether typhaneoside, a flavonoid from Typhae angustifolia pollen, affects endogenous glutamate release from rat cortical synaptosomes. Using a one-line enzyme-coupled fluorometric assay, glutamate release stimulated by the K+ channel blocker 4-aminopyridine was monitored to explore the possible underlying mechanisms. The vesicular transporter inhibitor bafilomycin A1 and chelation of extracellular Ca2+ ions with EGTA suppressed the effect of typhaneoside on the induced glutamate release. Nevertheless, the typhaneoside activity has not been affected by the glutamate transporter inhibitor dl-threo-beta-benzyloxyaspartate. The synaptosomal plasma membrane potential was assayed using a membrane potential-sensitive dye DiSC3(5), and cytosolic Ca2+ concentrations ([Ca2+]C) was monitored by a Ca2+ indicator Fura-2. Results showed that typhaneoside did not alter the synaptosomal membrane potential but lowered 4-aminopyridine-induced increases in [Ca2+]C. Furthermore, the Cav2.2 (N-type) channel blocker ω-conotoxin GVIA blocked Ca2+ entry and inhibited the effect of typhaneoside on 4-aminopyridine-induced glutamate release. However, the inhibitor of intracellular Ca2+ release dantrolene and the mitochondrial Na+/Ca2+ exchanger blocker 7-chloro-5-(2-chloropheny)-1,5-dihydro-4,1-benzothiazepin-2(3H)-one have no effect on the suppression of glutamate release mediated by typhaneoside. Moreover, inhibition of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) prevented the inhibitory effect of typhaneoside on induced glutamate release. Typhaneoside reduced 4-aminopyridine-induced phosphorylation of ERK1/2 and the major presynaptic ERK target synapsin I, which is a synaptic vesicle-associated protein. In conclusion, these findings suggest a role for typhaneoside in modulating glutamate release by suppressing voltage-dependent Ca2+ channel mediated presynaptic Ca2+ influx and the MAPK/ERK/synapsin I signaling cascade.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo N/metabolismo , Córtex Cerebral/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Glicosídeos/farmacologia , Animais , Córtex Cerebral/metabolismo , Masculino , Potenciais da Membrana/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismo
15.
Nitric Oxide ; 109-110: 33-41, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33667621

RESUMO

INTRODUCTION: THP-1 cells, a human leukemia monocytic cell line, differentiated by phorbol myristate acetate (PMA) are widely used as surrogate of human macrophages. Differentiated THP-1 cells acquire macrophage-like characteristics including more adherence and altered cell function. Nitric oxide (NO), an intracellular messenger, is critical in regulating cell differentiation. Here we elucidated whether NO relates to PMA-induced monocyte-to-macrophage differentiation of THP-1 cells. The mutual regulation of calcium and NO was also investigated. MATERIAL & METHODS: THP-1 cells were incubated with PMA for 24 h, followed by assay of adherence, morphological change, migration or IL-1ß release. L-NG-Nitroarginine methyl ester (l-NAME, a nitric oxide synthase inhibitor) or BAPTA-AM (a calcium chelator) was added before PMA stimulation, and levels of calcium and NO were measured. Furthermore, a selective inhibitor of inducible nitric oxide synthase (iNOS) activity was employed to study the role of iNOS. RESULTS AND DISCUSSION: Effects of PMA on upregulation of adherence, lipopolysaccharide-triggered IL-1ß, and migration ability of THP-1 cells were consistent with NO concentrations. Both l-NAME and BAPTA-AM mitigated effects of PMA on THP-1 cells differentiation. BAPTA-AM decreased levels of NO, while l-NAME had no effect on calcium levels. Of note, inhibition of iNOS activity decreased PMA-triggered upregulation of NO. CONCLUSION: PMA induced differentiation of THP-1 cells partially in a NO-dependent manner. The calcium signaling may mediate PMA-triggered upregulation of NO.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Óxido Nítrico/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Humanos , Macrófagos/metabolismo , Monócitos/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/metabolismo , Células THP-1 , Regulação para Cima/efeitos dos fármacos
16.
Prev Med ; 153: 106787, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34506818

RESUMO

A retrospective cohort study was conducted using claims data from Taiwan's National Health Insurance program to assess the effect of diabetic pay-for-performance (P4P) program on major adverse limb events (MALE) and major adverse cardiovascular events (MACE) in patients with type 2 diabetes mellitus (T2DM). This study included patients with T2DM who had completed or not completed a 1-year P4P program from 2002 to 2013. Propensity-score matching was used to balance the baseline characteristics between groups. The Cox proportional-hazard model and Fine and Gray subdistribution hazard model were used to examine the association between P4P and the risks of MALE, MACE, systemic thromboembolism (ST), heart failure (HF) hospitalization, and all-cause mortality. Patients who underwent the P4P program had a significantly decreased incidence of MALE (2.0% vs. 2.6%, subdistribution hazard ratio [SHR] 0.73, 95% CI 0.71-0.76). Regarding the individual components, the P4P group demonstrated lower risks for foot ulcer (1.1% vs 1.3%, SHR 0.80, 95% CI 0.77-0.84), gangrene (0.57% vs 0.93%, SHR 0.59, 95% CI 0.56-0.63), percutaneous transluminal angioplasty (0.61% vs 0.79%, SHR 0.72, 95% CI 0.68-0.77), and amputation (0.46% vs 0.75%, SHR 0.58, 95% CI 0.55-0.62). In addition, the risks of MACE, ST, HF hospitalization, and all-cause mortality were remarkably lower in the P4P group. The P4P program might significantly reduce critical events of MALE, MACE, ST, HF, and mortality in the diabetic population.


Assuntos
Diabetes Mellitus Tipo 2 , Reembolso de Incentivo , Estudos de Coortes , Diabetes Mellitus Tipo 2/epidemiologia , Humanos , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Taiwan/epidemiologia
17.
Can J Physiol Pharmacol ; 99(7): 737-743, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33175564

RESUMO

Oxycodone, a semisynthetic opioid analgesic with actions similar to morphine, is extensively prescribed for treatment of moderate to severe acute pain. Given that glutamate plays a crucial role in mediating pain transmission, the purpose of this study was to investigate the effect of oxycodone on glutamatergic synaptic transmission in rat hippocampal CA3 area, which is associated with the modulation of nociceptive perception. Whole-cell patch-clamp recordings revealed that oxycodone effectively reduced presynaptic glutamate release, as detected by decreased frequencies of spontaneous excitatory postsynaptic currents (sEPSCs) and miniature EPSCs (mEPSCs), without eliciting significant changes in the amplitudes of sEPSCs and mEPSCs and glutamate-evoked inward currents. The inhibitory effect of oxycodone on the frequency of sEPSCs was blocked by the nonselective opioid receptor antagonist naloxone. In addition, oxycodone suppressed burst firing induced by 4-aminopyridine and tonic repetitive firing evoked by the applied depolarizing current. These results suggest that oxycodone inhibits spontaneous presynaptic glutamate release possibly by activating opioid receptors and consequently suppressing the neuronal excitability of hippocampal CA3 neurons.


Assuntos
Neurônios , Animais , Potenciais Pós-Sinápticos Excitadores , Oxicodona , Ratos
18.
Int J Mol Sci ; 22(23)2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34884781

RESUMO

This study investigated the effects of enmein, an active constituent of Isodon japonicus Hara, on glutamate release in rat cerebrocortical nerve terminals (synaptosomes) and evaluated its neuroprotective potential in a rat model of kainic acid (KA)-induced glutamate excitotoxicity. Enmein inhibited depolarization-induced glutamate release, FM1-43 release, and Ca2+ elevation in cortical nerve terminals but had no effect on the membrane potential. Removing extracellular Ca2+ and blocking vesicular glutamate transporters, N- and P/Q-type Ca2+ channels, or protein kinase C (PKC) prevented the inhibition of glutamate release by enmein. Enmein also decreased the phosphorylation of PKC, PKC-α, and myristoylated alanine-rich C kinase substrates in synaptosomes. In the KA rat model, intraperitoneal administration of enmein 30 min before intraperitoneal injection of KA reduced neuronal cell death, glial cell activation, and glutamate elevation in the hippocampus. Furthermore, in the hippocampi of KA rats, enmein increased the expression of synaptic markers (synaptophysin and postsynaptic density protein 95) and excitatory amino acid transporters 2 and 3, which are responsible for glutamate clearance, whereas enmein decreased the expression of glial fibrillary acidic protein (GFAP) and CD11b. These results indicate that enmein not only inhibited glutamate release from cortical synaptosomes by suppressing Ca2+ influx and PKC but also increased KA-induced hippocampal neuronal death by suppressing gliosis and decreasing glutamate levels by increasing glutamate uptake.


Assuntos
Apoptose/efeitos dos fármacos , Lesões Encefálicas/prevenção & controle , Diterpenos/farmacologia , Ácido Glutâmico/metabolismo , Fármacos Neuroprotetores/farmacologia , Sinaptossomos/metabolismo , Sistema X-AG de Transporte de Aminoácidos/metabolismo , Animais , Lesões Encefálicas/induzido quimicamente , Antígeno CD11b/metabolismo , Cálcio/metabolismo , Proteína 4 Homóloga a Disks-Large/metabolismo , Transportador 2 de Aminoácido Excitatório/metabolismo , Transportador 3 de Aminoácido Excitatório/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Hipocampo/metabolismo , Ácido Caínico/toxicidade , Masculino , Potenciais da Membrana/efeitos dos fármacos , Neuroglia/metabolismo , Proteína Quinase C/metabolismo , Ratos , Ratos Sprague-Dawley , Sinaptofisina/metabolismo
19.
Angew Chem Int Ed Engl ; 60(32): 17701-17706, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34192402

RESUMO

The integration of Li2 S6 within a poly(ethylene oxide) (PEO)-based polymer electrolyte is demonstrated to improve the polymer electrolyte's ionic conductivity because the strong interplay between O2- (PEO) and Li+ from Li2 S6 reduces the crystalline volume within the PEO. The Li/electrolyte interface is stabilized by the in situ formation of an ultra-thin Li2 S/Li2 S2 layer via the reaction between Li2 S6 and lithium metal, which increases the ionic transport at the interface and suppresses lithium dendrite growth. A symmetric Li/Li cell with the Li2 S6 -integrated composite electrolyte has excellent cyclability and a high critical current density of 0.9 mA cm-2 at 40 °C. Impressive electrochemical performance is demonstrated with all-solid-state Li/LiFePO4 and high-voltage Li/LiNi0.8 Mn0.1 Co0.1 O2 cells at 40 °C.

20.
Environ Sci Technol ; 54(4): 2539-2547, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-31985212

RESUMO

Development of low-cost, high-efficiency, and environmentally benign adsorbents for mercury removal is of significant importance for environmental remediation. Herein, we report a novel porous puffed rice carbon (PRC) with co-implanted metal iron and sulfur, forming a high-quality PRC/Fe@S composite as a high-efficiency adsorbent for mercury removal from aqueous solution. The in situ-formed Fe nanoparticles in PRC are strongly coupled with sulfur via a supercritical CO2 fluid approach and dispersed homogeneously in the cross-linked hierarchical porous architecture. The pore formation mechanism of Fe on PRC is also proposed. The optimized PRC/Fe@S composite offers superior selective affinity, high removal efficiency, and ultrahigh adsorption capacity of up to 738.0 mg g-1. It is demonstrated that the hierarchical porous carbon in the PRC/Fe@S composite not only acts as a framework to stabilize and disperse Fe nanoparticles but also provides abundant pores and voids for absorbing Hg(II) from aqueous solution. More importantly, the absorbed Hg(II) can be reduced to Hg(0) by Fe and further chemically immobilized by sulfur. The enhanced coupled effect is discussed and proposed. Therefore, an innovative adsorption mechanism of adsorption-reduction-immobilization is proposed, which offers a new prospect in developing high-efficiency carbon-based adsorbents in environmental remediation.


Assuntos
Mercúrio , Oryza , Adsorção , Carbono , Ferro , Enxofre
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