Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
iScience ; 27(4): 109541, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38577108

RESUMO

As ectotherms, insects need heat-sensitive receptors to monitor environmental temperatures and facilitate thermoregulation. We show that TRPA5, a class of ankyrin transient receptor potential (TRP) channels absent in dipteran genomes, may function as insect heat receptors. In the triatomine bug Rhodnius prolixus (order: Hemiptera), a vector of Chagas disease, the channel RpTRPA5B displays a uniquely high thermosensitivity, with biophysical determinants including a large channel activation enthalpy change (72 kcal/mol), a high temperature coefficient (Q10 = 25), and in vitro temperature-induced currents from 53°C to 68°C (T0.5 = 58.6°C), similar to noxious TRPV receptors in mammals. Monomeric and tetrameric ion channel structure predictions show reliable parallels with fruit fly dTRPA1, with structural uniqueness in ankyrin repeat domains, the channel selectivity filter, and potential TRP functional modulator regions. Overall, the finding of a member of TRPA5 as a temperature-activated receptor illustrates the diversity of insect molecular heat detectors.

2.
Nat Nanotechnol ; 18(6): 580-588, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37157023

RESUMO

Metasurfaces have been rapidly advancing our command over the many degrees of freedom of light; however, so far, they have been mostly limited to manipulating light in free space. Metasurfaces integrated on top of guided-wave photonic systems have been explored to control the scattering of light off-chip with enhanced functionalities-namely, the point-by-point manipulation of amplitude, phase or polarization. However, these efforts have so far been limited to controlling one or two optical degrees of freedom at best, as well as device configurations much more complex compared with conventional grating couplers. Here we introduce leaky-wave metasurfaces, which are based on symmetry-broken photonic crystal slabs that support quasi-bound states in the continuum. This platform has a compact form factor equivalent to the one of grating couplers, but it provides full command over the amplitude, phase and polarization (four optical degrees of freedom) across large apertures. We present devices for phase and amplitude control at a fixed polarization state, and devices controlling all the four optical degrees of freedom for operation at a wavelength of 1.55 µm. Merging the fields of guided and free-space optics through the hybrid nature of quasi-bound states in the continuum, our leaky-wave metasurfaces may find applications in imaging, communications, augmented reality, quantum optics, LIDAR and integrated photonic systems.


Assuntos
Óptica e Fotônica , Fótons
3.
Antioxidants (Basel) ; 12(4)2023 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-37107178

RESUMO

L-theanine (LT), which is a major amino acid found in green tea, was shown to alleviate Vincristine (VCR)-induced peripheral neuropathy and associated neuronal functional changes in rats. To induce peripheral neuropathy, rats were administered VCR at a dose of 100 mg/kg/day intraperitoneally on days 1-5 and 8-12, while control rats received LT at doses of 30, 100, and 300 mg/kg/day intraperitoneally for 21 days or saline solution. Electrophysiological measurements were taken to evaluate the nerve functional loss and recovery through motor and sensory nerve conduction velocities. The sciatic nerve was examined for several biomarkers, including nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), total calcium, IL-6, IL-10, MPO, and caspase-3. The results showed that VCR caused significant hyperalgesia and allodynia in rats; decreased nerve conduction velocity; increased NO and MDA levels; and decreased GSH, SOD, CAT, and IL-10 levels. LT was found to significantly reduce VCR-induced nociceptive pain thresholds, decrease oxidative stress levels (NO, MDA), increase antioxidative strength (GSH, SOD, CAT), and reduce neuroinflammatory activity and apoptosis markers (caspase-3). LT's antioxidant, calcium homeostasis, anti-inflammatory, anti-apoptotic, and neuroprotective properties make it a potential adjuvant to conventional treatment in VCR-induced neuropathy in rats.

4.
J Exp Biol ; 226(7)2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36967715

RESUMO

The Australian lycaenid butterfly Jalmenus evagoras has iridescent wings that are sexually dimorphic, spectrally and in their degree of polarization, suggesting that these properties are likely to be important in mate recognition. We first describe the results of a field experiment showing that free-flying individuals of J. evagoras discriminate between visual stimuli that vary in polarization content in blue wavelengths but not in others. We then present detailed reflectance spectrophotometry measurements of the polarization content of male and female wings, showing that female wings exhibit blue-shifted reflectance, with a lower degree of polarization relative to male wings. Finally, we describe a novel method for measuring alignment of ommatidial arrays: by measuring variation of depolarized eyeshine intensity from patches of ommatidia as a function of eye rotation, we show that (a) individual rhabdoms contain mutually perpendicular microvilli; (b) many rhabdoms in the array have their microvilli misaligned with respect to neighboring rhabdoms by as much as 45 deg; and (c) the misaligned ommatidia are useful for robust polarization detection. By mapping the distribution of the ommatidial misalignments in eye patches of J. evagoras, we show that males and females exhibit differences in the extent to which ommatidia are aligned. Both the number of misaligned ommatidia suitable for robust polarization detection and the number of aligned ommatidia suitable for edge detection vary with respect to both sex and eye patch elevation. Thus, J. evagoras exhibits finely tuned ommatidial arrays suitable for perception of polarized signals, likely to match sex-specific life history differences in the utility of polarized signals.


Assuntos
Borboletas , Animais , Masculino , Feminino , Humanos , Austrália , Visão Ocular , Células Fotorreceptoras de Invertebrados
5.
Commun Biol ; 5(1): 1318, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36456867

RESUMO

We present an economical imaging system with integrated hardware and software to capture multispectral images of Lepidoptera with high efficiency. This method facilitates the comparison of colors and shapes among species at fine and broad taxonomic scales and may be adapted for other insect orders with greater three-dimensionality. Our system can image both the dorsal and ventral sides of pinned specimens. Together with our processing pipeline, the descriptive data can be used to systematically investigate multispectral colors and shapes based on full-wing reconstruction and a universally applicable ground plan that objectively quantifies wing patterns for species with different wing shapes (including tails) and venation systems. Basic morphological measurements, such as body length, thorax width, and antenna size are automatically generated. This system can increase exponentially the amount and quality of trait data extracted from museum specimens.


Assuntos
Museus , Registros , Fenótipo , Software
6.
Integr Cancer Ther ; 21: 15347354221077682, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35168384

RESUMO

The efficacy of chemotherapeutic drugs for the treatment of brain metastasis may be compromised by the blood-brain barrier (BBB) and blood-tumor barrier (BTB). P-glycoprotein (P-gp) is a multidrug resistance protein that potentially limits the penetration of chemotherapeutics through the BBB and BTB. 5-Fluorouracil (5-FU) is widely used to treat cancer. Bioactive constituents of medicinal herbs, such as borneol and tetrandrine, potentially improve drug penetration through the BBB and BTB. We hypothesized that borneol and tetrandrine might modulate the BBB and BTB to enhance 5-FU penetration into the brain. To investigate this, in vitro and in vivo models were developed to explore the modulatory effects of borneol and tetrandrine on 5-FU penetration through the BBB and BTB. In the in vitro models, barrier integrity, cell viability, barrier penetration, P-gp activity, and NF-κB expression were assessed. In the in vivo brain metastasis models, cancer cells were injected into the internal carotid artery to evaluate tumor growth. The experimental results demonstrated that borneol and borneol + tetrandrine reduced BBB integrity. The efflux pump function of P-gp was partially inhibited by tetrandrine and borneol + tetrandrine. In the in vivo experiment, borneol + tetrandrine effectively prolonged survival without compromising body weight. In conclusion, BBB and BTB integrity was modulated by borneol and borneol + tetrandrine. The combination of borneol and tetrandrine could be used to improve the chemotherapeutic control of brain metastasis.


Assuntos
Barreira Hematoencefálica , Neoplasias Encefálicas , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Benzilisoquinolinas , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Canfanos , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Humanos
7.
J Formos Med Assoc ; 121(4): 802-814, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34531102

RESUMO

BACKGROUND/PURPOSE: We investigated the protective efficacy of l-theanine (LT), the major amino acid components of green tea, on chronic constriction injury (CCI) of sciatic nerve-induced neuropathic pain (NP) development and neuronal functional changes in rats. METHODS: Rats with NP induced by CCI of the left sciatic nerve and sham-operated rats received LT or saline solution, with pain sensitive tests of thermal hyperalgesia and mechanical allodynia. Motor and sensory nerve conduction velocities were measured after surgery. Subsequently, the rats were sacrificed; the sciatic nerve was excised, homogenized, prepared and subjected for estimation of nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), myeloperoxidase (MPO), and caspase-3. RESULTS: CCI produced a significant increase in hyperalgesia and allodynia, an increase in SFI, a decrease in nerve conduction velocity, increases in NO, MDA, TNF-α, IL-1ß, IL-6, MPO, and caspase-3 levels, as well as reduction of GSH, SOD, and CAT in the rat sciatic nerve. LT treatment significantly and dose-dependently alleviated CCI-induced nociceptive pain thresholds and ameliorated abnormal nerve conduction and functional loss in rats with CCI. Moreover, LT treatment reduced NO and MDA levels, increased antioxidative strength, and markedly suppressed the levels of neuroinflammatory and apoptotic markers in injured sciatic nerves. CONCLUSION: This is the first report on the ameliorative effect of LT in CCI-induced NP in rats. This effect might be attributed to its anti-oxidative, anti-inflammatory, anti-apoptotic, and neuroprotective, thus making it potentially useful as an adjuvant to conventional treatment.


Assuntos
Neuralgia , Fármacos Neuroprotetores , Animais , Constrição , Glutamatos , Humanos , Hiperalgesia/tratamento farmacológico , Hiperalgesia/patologia , Hiperalgesia/prevenção & controle , Neuralgia/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Ratos , Nervo Isquiático/lesões , Nervo Isquiático/patologia
8.
Medicine (Baltimore) ; 99(52): e23771, 2020 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-33350762

RESUMO

BACKGROUND: Lesional and symptomatic causes of epilepsy are the most common neurological disorders of the brain. Topiramate effectively controls newly diagnosed epilepsy and refractory focal seizures, but high-dose topiramate does not improve seizure control. This study aimed to evaluate the clinical efficacy and safety of dose-escalated topiramate as first-line monotherapy and add-on therapy in patients with neurosurgery-related epilepsy. MATERIAL AND METHODS: A total of 55 neurosurgical patients with epilepsy were divided into monotherapy and add-on therapy groups and both groups received topiramate via the dose-escalation method. The primary efficacy outcomes were seizure-free rate and seizure response rate. Adverse events and seizure frequency were recorded. RESULTS: The seizure response rate in the first month of monotherapy was significantly better than that of add-on therapy (89% vs 65%, P < .05), but no significant differences were found in seizure response rates between the 2 groups after 2 months of treatment. Both monotherapy and add-on therapy were effective in controlling seizures, with mean seizure frequency of 0.725 vs 0.536 and seizure-free rate of 88% vs 78.6%. Both treatments showed good improvement of seizure frequency in patients without tumor. The efficacy of monotherapy was better than that of add-on therapy (80% vs 29.2%) in patients with body mass index (BMI) ≤24. However, add-on therapy was better than monotherapy (76.7% vs 21.4%) in patients with BMI > 24. Dizziness (25.5%) and headache (16.4%) were the most common adverse events. No severe adverse event such as cognitive impairment was observed. CONCLUSIONS: Dose-escalated topiramate monotherapy and add-on therapy demonstrate good efficacy and safety, with fewer adverse events in seizure control in neurosurgical patients.


Assuntos
Relação Dose-Resposta a Droga , Quimioterapia Combinada/métodos , Epilepsia , Procedimentos Neurocirúrgicos/efeitos adversos , Complicações Pós-Operatórias , Topiramato , Adulto , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/efeitos adversos , Monitoramento de Medicamentos/métodos , Epilepsia/diagnóstico , Epilepsia/tratamento farmacológico , Epilepsia/etiologia , Feminino , Humanos , Masculino , Avaliação de Processos e Resultados em Cuidados de Saúde , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/tratamento farmacológico , Topiramato/administração & dosagem , Topiramato/efeitos adversos , Resultado do Tratamento
9.
Diabetes Metab Syndr Obes ; 13: 2269-2277, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32636661

RESUMO

BACKGROUND: Adropin is a secreted polypeptide that has been demonstrated to play an important role in energy homeostasis and lipid metabolism. Signal transducer and activator of transcription 3 (STAT3) may promote the transcription of target genes including adropin. In the current study, we investigated the effect of adropin on glucose metabolism in diabetic rats and the mechanism that governs this effect was subsequently assessed. MATERIALS AND METHODS: Rats received a single injection of streptozotocin to induce type 1 diabetes. The diabetic rats were treated with insulin or phloridzin, another antidiabetic agent through inhibition of glucose reabsorption, for 7 days. Plasma glucose levels and adropin levels were measured. The interaction between STAT3 and adropin was evaluated using the human hepatoma HepG2 cell line. HepG2 cells were pretreated with the specific antagonist Stattic or with STAT3-specific siRNAs to knockout STAT3. Changes in energy homeostasis-associated gene expression were measured using real-time PCR. The protein expression levels of pSTAT3 and STAT3 were measured using Western blotting. RESULTS: In diabetic rats, the serum concentrations of adropin were increased in the vehicle-treated group and decreased in the insulin- or phloridzin-treated group. In liver tissues, the Enho expression level and the activity of STAT3 also showed similar tendencies. After HepG2 cells were treated with medium containing high glucose, the ratio of p-STAT3 to STAT3, Enho mRNA levels and reactive oxygen species expression levels in HepG2 cells were significantly increased in conjunction with increased glucose levels. The effect was inhibited after pretreatment with Stattic or knockdown with STAT3-specific siRNAs. CONCLUSION: STAT3 is involved in the genetic regulation of adropin, increasing the levels of circulating adropin and promoting Enho expression in the livers of diabetic rats.

11.
Sci Adv ; 6(17): eaaz5413, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32426464

RESUMO

Solar reflective and thermally emissive surfaces offer a sustainable way to cool objects under sunlight. However, white or silvery reflectance of these surfaces does not satisfy the need for color. Here, we present a paintable bilayer coating that simultaneously achieves color and radiative cooling. The bilayer comprises a thin, visible-absorptive layer atop a nonabsorptive, solar-scattering underlayer. The top layer absorbs appropriate visible wavelengths to show specific colors, while the underlayer maximizes the reflection of near-to-short wavelength infrared (NSWIR) light to reduce solar heating. Consequently, the bilayer attains higher NSWIR reflectance (by 0.1 to 0.51) compared with commercial paint monolayers of the same color and stays cooler by as much as 3.0° to 15.6°C under strong sunlight. High NSWIR reflectance of 0.89 is realized in the blue bilayer. The performances show that the bilayer paint design can achieve both color and efficient radiative cooling in a simple, inexpensive, and scalable manner.

12.
J Healthc Eng ; 2020: 1323270, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32076494

RESUMO

Recent years have seen a rapidly rising number of oxygenated water brands that claim to impart health benefits and increase athletic performance by improving oxygen availability in the body. Drinks with higher dissolved oxygen concentrations have in recent times gained popularity as potential ergogenic aids, despite the lack of evidence regarding their efficacy. The aim of this study was to characterize oxygenated water and assess the improvement in uric acid metabolism while identifying performance enhancements in animals administered oxygenated water. Oxygenated water was characterized by hydrogen and oxygen nuclear magnetic resonance (NMR) spectroscopy. Hyperuricemia in rats was induced by treatment with oxonic acid potassium salt, and the animals were given oxygenated drinking water before, during, or after oxonic acid treatment. Serum uric acid was measured to confirm the effects on uric acid metabolism. Following oxygenation, the full width at half maximum (FWHM) was reduced to 11.56 Hz and 64.16 Hz in the hydrogen and oxygen NMR spectra, respectively. Oxygenated water molecule clusters were reduced in size due to the reduction in FWHM. Oxygen concentration did not vary significantly with increased temperature. However, standing time played a critical role in the amount of oxygen dissolved in the water. The rat studies indicated that oxygenated water reduced serum uric acid levels and their rate of increase and enhanced uric acid metabolism. A significant improvement in uric acid metabolism and rate of increase in serum uric acid concentration was observed in hyperuricemic rats administered oxygenated water compared to that in rats administered regular water. High oxygen concentrations enhanced the rate of oxygen absorption, leading to increased glycolysis and mitochondrial protein synthesis. Therefore, oxygenated water is a potential adjuvant therapy or health food for treatment of hyperuricemia.


Assuntos
Água Potável , Hiperuricemia/metabolismo , Oxigênio/administração & dosagem , Oxigênio/metabolismo , Animais , Hiperuricemia/sangue , Modelos Animais , Ratos
13.
Nat Commun ; 11(1): 551, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992708

RESUMO

The wings of Lepidoptera contain a matrix of living cells whose function requires appropriate temperatures. However, given their small thermal capacity, wings can overheat rapidly in the sun. Here we analyze butterfly wings across a wide range of simulated environmental conditions, and find that regions containing living cells are maintained at cooler temperatures. Diverse scale nanostructures and non-uniform cuticle thicknesses create a heterogeneous distribution of radiative cooling that selectively reduces the temperature of structures such as wing veins and androconial organs. These tissues are supplied by circulatory, neural and tracheal systems throughout the adult lifetime, indicating that the insect wing is a dynamic, living structure. Behavioral assays show that butterflies use wings to sense visible and infrared radiation, responding with specialized behaviors to prevent overheating of their wings. Our work highlights the physiological importance of wing temperature and how it is exquisitely regulated by structural and behavioral adaptations.


Assuntos
Adaptação Fisiológica/fisiologia , Comportamento Animal , Borboletas/fisiologia , Termotolerância/fisiologia , Asas de Animais/fisiologia , Animais , Metabolismo Energético/fisiologia , Hemolinfa/fisiologia , Raios Infravermelhos , Modelos Biológicos , Nanoestruturas , Energia Solar , Temperatura , Termodinâmica , Sensação Térmica , Asas de Animais/anatomia & histologia , Asas de Animais/citologia , Asas de Animais/efeitos da radiação
14.
Polymers (Basel) ; 12(1)2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31963243

RESUMO

Dental caries (tooth decay) is the most frequent oral disease in humans. Filling cavities with a dental restorative material is the most common treatment, and glass ionomer cements are the main fluoride ion release restorative materials. The goal of this study was to develop a restorative compound with superior fluoride ion release and recharge abilities. Previously developed fluorinated bentolite and hydrophobized 3YSZ were used as two different inorganic fillers mixed in a bisphenol A-glycidyl methacrylate (Bis-GMA) matrix. XRD, FTIR, and TGA were used to determine the hydrophobic modification of these two inorganic fillers. In mechanical tests, including diameter tensile strength, flexural strength, and wear resistance, the developed composite resin was significantly superior to the commercial control. A WST-1 assay was used to confirm that the material displayed good biocompatibility. Furthermore, the simulation of the oral environment confirmed that the composite resin had good fluoride ion release and reloading abilities. Thus, the composite resin developed in this study may reduce secondary caries and provide a new choice for future clinical treatments.

15.
Neurotox Res ; 37(3): 669-682, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31811588

RESUMO

Rotenone (ROT)-induced neurotoxicity has been used for decades as an animal model of Parkinson's disease (PD) in humans. This model exhibits pathophysiological features similar to those reported in patients with PD, namely, striatal nitrosative and oxidative stress, mitochondrial dysfunction, and neural cytoarchitecture alteration. (-)Epigallocatechin-3-gallate (EGCG), the most abundant and potent green tea catechin, has notable anti-oxidative, anti-inflammatory, and neuroprotective effects. The objective of the present study was to investigate the potential protective effects of EGCG on ROT-induced motor and neurochemical dysfunctions in rats. Furthermore, we also aimed to study the neuroprotective mechanisms underlying these effects. ROT treatment (0.5 mg/kg s.c., 21 days) reduced body weight and induced significant motor impairments as assessed using an open-field test, rotarod test, grip strength measurement, and beam-crossing task. EGCG treatment (100 or 300 mg/kg i.p., 60 min prior to ROT administration, 21 days) prevented most of the ROT-induced motor impairments. Moreover, EGCG treatment reduced ROT-induced nitric oxide (NO) level and lipid peroxidation (LPO) production; increased the activity of succinate dehydrogenase (SDH), ATPase, and ETC enzymes and the levels of catecholamines in the striatum; and reduced the levels of neuroinflammatory and apoptotic markers. These results demonstrate the possible neuroprotective effects of EGCG against ROT-induced motor impairments, including anti-oxidatory effect, prevention of mitochondrial dysfunction, prevention of neurochemical deficiency, anti-neuroinflammatory effect, and anti-apoptotic effect. This is the first report about the neuroprotective effect of EGCG against ROT-induced motor impairments, and the above evidence provides a potential clinically relevant role for EGCG in delaying or treating human PD.


Assuntos
Catequina/análogos & derivados , Corpo Estriado/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Transtornos Parkinsonianos/prevenção & controle , Rotenona/toxicidade , Animais , Apoptose/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Catequina/administração & dosagem , Corpo Estriado/metabolismo , Modelos Animais de Doenças , Encefalite/induzido quimicamente , Mediadores da Inflamação/metabolismo , Masculino , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/metabolismo , Ratos Wistar
16.
J Formos Med Assoc ; 119(9): 1405-1414, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31812333

RESUMO

BACKGROUND/PURPOSE: Spinal cord injury (SCI) is a devastating medical condition for which no effective pharmacological interventions exist. l-Theanine (LT), a major amino acid component of green tea, exhibits potent antioxidative and anti-inflammatory activities and protects against various neural injuries. Here, we evaluated the potential therapeutic effects of LT on the recovery of behavioral motor functions after SCI in rats and the underlying neuroprotective mechanisms. METHODS: SCI was induced by applying vascular clips to the dura through a four-level T5-T8 laminectomy, and saline or LT (10/30 mg/kg) was intrathecally administered at 1-, 6-, and 24-h post-SCI. At 72-h post-SCI, half of the rats from each group for each parameter were sacrificed, and their spinal cord was excised for measurement of malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase, catalase, tumor necrosis factor-α, interleukin-1ß/-6, myeloperoxidase, and caspase-3. The remaining rats from each group were subjected to Bresnahan locomotor-rating scale (BBB), inclined-plane, toe-spread, and hindfoot bar-grab tests at 1-, 4-, 7-, 10-, and 14-days post-SCI. RESULTS: LT treatment reduced NO and MDA levels, increased antioxidative strength, and markedly suppressed the levels of neuroinflammatory and apoptotic markers in the spinal cord after SCI. Moreover, LT treatment drastically promoted the recovery of behavioral motor functions post-SCI. CONCLUSION: Our findings revealed that LT can enhance the recovery of behavioral motor functions after SCI in rats, which related to the suppression of post-traumatic oxidative response, neural inflammation, and apoptosis. This evidence indicates that LT holds considerable potential for use in the clinical treatment/prevention of SCI-induced motor dysfunction.


Assuntos
Glutamatos/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Estresse Oxidativo , Traumatismos da Medula Espinal , Animais , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal/tratamento farmacológico
17.
Sci Rep ; 9(1): 18390, 2019 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-31804535

RESUMO

Oxytocin (OT) has been reported to have a protective effect in lipopolysaccharide-induced experimental acute lung injury (ALI). However, its role in heat stroke-related ALI has never been investigated. Herein, we aimed to explore the therapeutic effects and potential mechanism of action of OT on heat-induced ALI. Rats were treated with OT 60 min before the start of heat stress (42 °C for 80 min). Twenty minutes after the termination of heat stress, the effects of OT on lung histopathological changes, edema, acute pleurisy and the bronchoalveolar fluid levels of inflammatory cytokines and indicators of ischemia, cellular damage, and oxidative damage were assessed. We also evaluated the influence of OT pretreatment on heat-induced hypotension, hyperthermia, ALI score, and death in a rat model of heat stroke. The results showed that OT significantly reduced heat-induced lung edema, neutrophil infiltration, hemorrhage score, myeloperoxidase activity, ischemia, and the levels of inflammatory and oxidative damage markers in bronchoalveolar lavage fluid. The survival assessment confirmed the pathophysiological and biochemical results. An OT receptor antagonist (L-368,899) was administered 10 min before the OT injection to further demonstrate the role of OT in heat-induced ALI. The results showed that OT could not protect against the aforementioned heat stroke responses in rats treated with L-368,899. Interestingly, OT treatment 80 min after the start of heat shock did not affect survival. In conclusion, our data indicate that OT pretreatment can reduce the ischemic, inflammatory and oxidative responses related to heat-induced ALI in rats.


Assuntos
Lesão Pulmonar Aguda/prevenção & controle , Febre/tratamento farmacológico , Golpe de Calor/prevenção & controle , Hipotensão/prevenção & controle , Ocitocina/farmacologia , Substâncias Protetoras/farmacologia , Edema Pulmonar/prevenção & controle , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/mortalidade , Lesão Pulmonar Aguda/patologia , Animais , Líquido da Lavagem Broncoalveolar/química , Canfanos/farmacologia , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Febre/metabolismo , Febre/mortalidade , Febre/patologia , Golpe de Calor/metabolismo , Golpe de Calor/mortalidade , Golpe de Calor/patologia , Resposta ao Choque Térmico , Hipotensão/metabolismo , Hipotensão/mortalidade , Hipotensão/patologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Infiltração de Neutrófilos , Peroxidase/genética , Peroxidase/metabolismo , Piperazinas/farmacologia , Edema Pulmonar/metabolismo , Edema Pulmonar/mortalidade , Edema Pulmonar/patologia , Ratos , Ratos Sprague-Dawley , Receptores de Ocitocina/antagonistas & inibidores , Receptores de Ocitocina/genética , Receptores de Ocitocina/metabolismo , Análise de Sobrevida
18.
Polymers (Basel) ; 11(10)2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31547022

RESUMO

Molar pits and fissures tend to be affected by caries due to cleaning difficulties. As such, the filling of pits and cracks with sealants is common to deter the onset of caries. However, current clinical practices rely on sealants that lack the ability to release and recharge fluoride ions. Thus, we herein report the development of a fluoride-montmorillonite nanocomposite resin that has the potential to provide sustained release of fluoride due to the strong adsorption of fluoride by montmorillonite. X-ray diffractometry, thermogravimetric analysis, and Fourier-transform infrared spectroscopy were employed to confirm the successful insertion of the polymer into the interlayer structure. The mechanical properties (viscosity, hardening depth, hardness, diametral tensile strength, flexural strength, and wear resistance) of the developed composite resin were then examined, and simulation of the oral environment demonstrated a good fluoride ion release and recharge ability for the effective prevention of dental caries. Finally, we demonstrated the non-cytotoxic nature of this material using the water-soluble tetrazolium salt (WST-1) test. We expect that the described fluoride-containing composite resin may become a new clinical option in the near future.

19.
Chin J Physiol ; 62(1): 17-26, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30942195

RESUMO

Having powerful antioxidative properties, L-theanine (LT), one of the major amino acid components in green tea, has potent anti-oxidative and neuroprotective effects. In this study, we examined the potential protective effects of LT on haloperidol (HAL)-induced orofacial dyskinesia (OD) in rats. HAL treatment (1 mg/kg intraperitoneally for 21 days) induced OD; significant increases (P < 0.001) in the frequency of vacuous chewing movement and tongue protrusion as well as the duration of facial twitching. LT treatment (100 mg/kg orally for 35 days, starting 14 days before HAL injection) was able to prevent most of the HAL-induced OD. LT treatment was also able to reduce the lipid peroxidation production and nitric oxide (NO) level, and enhance the antioxidation power in striatum from rats with HAL treatment. In order to examine the implication of NO pathway activity in HAL treatment, either NO precursor (L-arginine) or NO synthase inhibitor (L-NAME) was co-pretreated with LT; NO precursor treatment eliminated the protective effect of LT, in contrast to that NO synthase inhibitor treatment significantly potentiated the LT effects on behavioral and biochemical protection in HAL-treated rats. These results suggested that the NO pathway was implicated, at least in part, in the HAL-induced OD, as well as in the protective effect of LT in treating HAL-induced OD. The above evidence provides a clinically relevant value for LT in delaying or treating tardive dyskinesia.


Assuntos
Discinesias , Animais , Antipsicóticos , Glutamatos , Haloperidol , Óxido Nítrico , Ratos , Ratos Wistar
20.
J Food Drug Anal ; 27(1): 355-364, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30648591

RESUMO

Cardiac hypertrophy is widely diagnosed in clinical cardiac disorders. The pathophysiology of hypertrophy is complex and multifactorial, a series of molecular and cellular changes are participated, such as activation of different signaling pathways, a switch of fetal gene program in the myocardium, and apoptosis. Some biomarkers have been applied to assess cardiac hypertrophy including atrial natriuretic peptides (ANP), brain/B-type natriuretic peptides (BNP), and α- or ß- Myosin Heavy Chain (MHC) in addition to others. Recently, ubiquitin-protein ligase E3A (UBE3A) has been observed to increase in cardiac hypertrophy. Therefore, UBE3A as a new biomarker seems valuable in the clinic. The cardiac hypertrophy is induced in rat-derived heart cell line H9c2 cells by potassium bromate (KBrO3), high glucose (HG), or isoproterenol (Iso), respectively. As an oxidizing agent, KBrO3 increased cell size at concentrations less than 250 µM. Similarly, HG and Iso also induced cardiac hypertrophy in H9c2 cells. Interestingly, each kind of the cell models promoted the gene expression of the well-known biomarkers of cardiac hypertrophy including atrial natriuretic peptides (ANP) and brain/B-type natriuretic peptides (BNP). Additionally, UBE3A is also raised with the signals involved in cardiac hypertrophy such as calcineurin and nuclear factor of activated T-cells (NFAT) determined using Western blots. KBrO3 increased the protein levels of these signals and the specific inhibitor, such as cyclosporine A and tacrolimus, attenuated the signaling in H9c2 cells at concentrations sufficient to inhibit calcineurin in addition to the reduction of mRNA levels of UBE3A, similar to ANP or BNP. Moreover, HG or Iso also significantly increased protein levels of UBE3A in H9c2 cells. Taken together, we provided a new view that UBE3A is markedly raised in cardiac hypertrophy using various cell models, mainly through the activation of the calcineurin/NFAT signaling pathway in H9c2 cells. Therefore, UBE3A could be developed as a new biomarker in the diagnosis of cardiac hypertrophy.


Assuntos
Cardiomegalia/enzimologia , Miócitos Cardíacos/enzimologia , Ubiquitina-Proteína Ligases/metabolismo , Animais , Fator Natriurético Atrial/metabolismo , Biomarcadores/metabolismo , Calcineurina/genética , Calcineurina/metabolismo , Cardiomegalia/genética , Cardiomegalia/metabolismo , Linhagem Celular , Humanos , Modelos Biológicos , Miócitos Cardíacos/metabolismo , Fatores de Transcrição NFATC/genética , Fatores de Transcrição NFATC/metabolismo , Peptídeo Natriurético Encefálico/metabolismo , Ratos , Ubiquitina-Proteína Ligases/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA