RESUMO
Transparent materials are widely used in industries, everyday life, and scientific activities. The development of new, lightweight, and durable artificial transparent materials is a challenge in synthetic chemistry. In this study, a supramolecular approach is conceived to construct transparent glass. Cyclodextrins are selected as the building blocks for the fabrication of supramolecular glass via noncovalent polymerization. The newly formed glass displays several attractive advantages, including good thermal processability, high mechanical strength and dielectric constant, excellent visible light transparency, and good adhesion performance. Importantly, the structural characteristics of long-range disorder and short-range order are observed in cyclodextrin glass. Here a new strategy is presented for the preparation and functionalization of low-molecular-weight transparent materials.
RESUMO
Adhesive materials have played an essential role in the history of humanity. Natural adhesives composed of low-molecular-weight monomers have been overshadowed by modern petroleum-based glues. With the development of green economy, the demand for eco-friendly materials has increased. Herein, two natural biocompatible compounds, namely thioctic acid (TA) and malic acid (MA), are selected to prepare a high-performance pressure-sensitive adhesive poly[TA-MA]. This adhesive can be quantitatively obtained via a simple mixing and heating process. Poly[TA-MA] shows interesting and useful properties, including reversible flexibility, high elongation, and good self-healing, owing to its dynamic polymerization pattern and reversible cross-linking behavior. Poly[TA-MA] exhibits excellent adhesion performance under various extreme conditions, such as at low temperatures and in hot water. High values of shear strength (3.86 MPa), peel strength (7.90 N cm-1), loop tack (10.60 N cm-1), tensile strength (1.02 MPa), and shear resistance (1628 h) demonstrate the strong adhesive effect of poly[TA-MA]. Additionally, TA can be regenerated in the monomer forms from poly[TA-MA] with high recovery rate (>90%). Meanwhile, strong anti-bacterial behavior of poly[TA-MA] is recorded. This study not only reported a new pressure-sensitive adhesive but also fully displayed the feasibility of using natural small molecules to achieve robust surface adhesion.
RESUMO
Psychological stress is strain affecting the intangible self, caused by problems in adaptation, perception, and emotions. Previous studies have demonstrated that arginine vasopressin (AVP) plays an important role in psychological stress. The goal of present study was to investigate the interaction between AVP release and cardiovascular functions by measuring AVP concentration and recording blood pressure or heart rate during psychological stress in human. The results showed that (1) psychological stress not only increased the systolic blood pressure, diastolic blood pressure and heart rate, but also elevated the cortisol and AVP concentration in both plasma and CSF in a stress level-dependent manner; (2) there was a positive relationship between plasma AVP concentration and systolic blood pressure, diastolic blood pressure, heart rate or plasma cortisol concentration; (3) there was also a positive relationship between AVP concentrations in plasma and CSF AVP. The data suggested that plasma AVP, which might come from the central nervous system, might influence the cardiovascular functions during psychological stress in human.
Assuntos
Arginina Vasopressina/sangue , Arginina Vasopressina/líquido cefalorraquidiano , Estresse Psicológico/sangue , Estresse Psicológico/líquido cefalorraquidiano , Adolescente , Adulto , Pressão Sanguínea , Feminino , Frequência Cardíaca , Humanos , Hidrocortisona/sangue , Hidrocortisona/líquido cefalorraquidiano , Masculino , Adulto JovemRESUMO
Oxytocin (OXT), a nonapeptide hormone of posterior pituitary, reaches the central nervous system from systemic blood circulation with a difficulty because of the blood-brain barrier (BBB). The interest has been expressed in the use of the nasal route for delivery of OXT to the brain directly, exploiting the olfactory pathway. Our previous study has demonstrated that OXT in the central nervous system rather than the blood circulation plays an important role in rat pain modulation. The communication tried to investigate the interaction between the OXT and pain modulation in Chinese patients with headache to understand the OXT effect on human pain modulation. The results showed that (1) intranasal OXT could relieve the human headache in a dose-dependent manner; (2) OXT concentration in both plasma and cerebrospinal fluid (CSF) increased significantly in headache patients in relation with the pain level; and (3) there was a positive relationship between plasma and CSF OXT concentration in headache patients. The data suggested that intranasal OXT, which was delivered to the central nervous system through olfactory region, could treat human headache and OXT might be a potential drug of headache relief by intranasal administration.
Assuntos
Cefaleia/tratamento farmacológico , Ocitocina/uso terapêutico , Dor/tratamento farmacológico , Administração Intranasal , Adulto , Povo Asiático , Relação Dose-Resposta a Droga , Feminino , Cefaleia/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Ocitocina/sangue , Ocitocina/líquido cefalorraquidiano , Dor/fisiopatologia , Medição da Dor/efeitos dos fármacos , Adulto JovemRESUMO
Arginine vasopressin (AVP), a nonapeptide posterior hormone of the pituitary, is mainly synthesized and secreted in the hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON). Large numbers of studies have reported that AVP plays a role in depression. The present study was to investigate by which level, brain or periphery, AVP affects the behavioral activity in the behavior despair depression rat model. The results showed that (1) either forced swimming or tail suspension significantly increased AVP concentration not only in the brain (PVN, SON, frontal of cortex, hippocampus, amygdala, lumber spinal cord) but also in the periphery (posterior pituitary and serum); (2) intraventricular injection (icv) of AVP decreased the animal immobility time, whereas V1 receptor antagonist d(CH2)5Tyr(Me)AVP (icv) increased the animal immobility time in a dose-dependent manner not only in FST but also in TST, but the V2 receptor antagonist d(CH2)5[D-Ile, Ile, Ala-NH9]AVP did not change the animal immobility time in FST or TST; (3) V1, not V2 receptor antagonist could inhibit the animal immobility time decrease induced by AVP (icv); (4) neither AVP nor its receptor antagonist (including V1 and V2 receptor antagonist) influenced the animal immobility time in both FST and TST. The data suggested that AVP in the brain rather than the periphery played a role in the behavior despair depression by V1, not V2 receptors, which behavior despair might have a positive feedback effect on central AVP and blood AVP might have a negative feedback on central AVP in the depressive process.
Assuntos
Arginina Vasopressina/farmacologia , Comportamento Animal/efeitos dos fármacos , Depressão/psicologia , Animais , Antagonistas dos Receptores de Hormônios Antidiuréticos , Arginina Vasopressina/sangue , Desamparo Aprendido , Elevação dos Membros Posteriores , Injeções Intravenosas , Injeções Intraventriculares , Masculino , Hipófise/efeitos dos fármacos , Hipófise/metabolismo , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo , Natação/psicologiaRESUMO
Arginine vasopressin (AVP), a nonapeptide hormone of posterior pituitary, reaches the central nervous system from systemic blood circulation with a difficulty because of the blood-brain barrier (BBB). The interest has been expressed in the use of the nasal route for delivery of AVP to the brain directly, exploiting the olfactory pathway. Our previous study has demonstrated that AVP in the brain rather than the spinal cord and blood circulation plays an important role in rat pain modulation. For understanding the role of AVP on pain modulation in human, the communication tried to investigate the effect of intranasal AVP on human headache. The results showed that (1) AVP concentration in both plasma and cerebrospinal fluid (CSF) increased significantly in headache patients, who related with the headache level; (2) there was a positive relationship between plasma and CSF AVP concentration in headache patients; and (3) intranasal AVP could relieve the human headache in a dose-dependent manner. The data suggested that intranasal AVP, which was delivered to the brain through olfactory region, could treat human headache and AVP might be a potential drug of pain relief by intranasal administration.
Assuntos
Arginina Vasopressina/administração & dosagem , Arginina Vasopressina/uso terapêutico , Cefaleia/tratamento farmacológico , Administração Intranasal , Adulto , Arginina Vasopressina/sangue , Arginina Vasopressina/líquido cefalorraquidiano , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto JovemRESUMO
Periaqueductal gray (PAG) plays a very important role in pain modulation through endogenous opiate peptides including leucine-enkephalin (L-Ek), methionine-enkephalin (M-Ek), ß-endorphin (ß-Ep) and dynorphin A(1-13) (DynA(1-13)). Our pervious study has demonstrated that intra-PAG injection of oxytocin (OXT) increases the pain threshold, and local administration of OXT receptor antagonist decreases the pain threshold, in which the antinociceptive role of OXT can be reversed by pre-PAG administration of OXT receptor antagonist. The experiment was designed to investigate the effect of OXT on endogenous opiate peptides in the rat PAG during the pain process. The results showed that (1) the concentrations of OXT, L-Ek, M-Ek and ß-Ep, not DynA(1-13) in the PAG perfusion liquid were increased after the pain stimulation; (2) the concentrations of L-Ek, M-Ek and ß-Ep, not DynA(1-13) in the PAG perfusion liquid were decreased by the OXT receptor antagonist; (3) the increased pain threshold induced by the OXT was attenuated by naloxone, an opiate receptor antagonist; and (4) the concentrations of L-Ek, M-Ek and ß-Ep, not DynA(1-13) in the PAG perfusion liquid were increased by exogenous OXT administration. The data suggested that OXT in the PAG could influence the L-Ek, M-Ek and ß-Ep rather than DynA(1-13) to participate in pain modulation, i.e. OXT in the PAG participate in pain modulation by influencing the L-Ek, M-Ek and ß-Ep rather than DynA(1-13).
Assuntos
Microinjeções/métodos , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Ocitocina/farmacologia , Limiar da Dor/efeitos dos fármacos , Substância Cinzenta Periaquedutal , Animais , Cateterismo , Dinorfinas/análise , Dinorfinas/biossíntese , Encefalina Leucina/análise , Encefalina Leucina/biossíntese , Encefalina Metionina/análise , Encefalina Metionina/biossíntese , Dor , Medição da Dor , Limiar da Dor/fisiologia , Fragmentos de Peptídeos/análise , Fragmentos de Peptídeos/biossíntese , Substância Cinzenta Periaquedutal/efeitos dos fármacos , Substância Cinzenta Periaquedutal/metabolismo , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , beta-Endorfina/análise , beta-Endorfina/biossínteseRESUMO
Our previous study has demonstrated that the hypothalamic supraoptic nucleus (SON) plays a role in pain modulation. Oxytocin (OXT) and arginine vasopressin (AVP) are the important hormones synthesized and secreted by the SON. The experiment was designed to investigate which hormone was relating with the antinociceptive role of the SON in the rat. The results showed that (1) microinjection of L-glutamate sodium into the SON increased OXT and AVP concentrations in the SON perfusion liquid, (2) pain stimulation induces OXT, but not AVP release in the SON, and (3) intraventricular injection (pre-treatment) with OXT antiserum could inhibit the pain threshold increase induced by SON injection of L-glutamate sodium, but administration of AVP antiserum did not influence the antinociceptive role of SON stimulation. The data suggested that the antinociceptive role of the SON relates to OXT rather than AVP.
Assuntos
Analgésicos/farmacologia , Arginina Vasopressina/metabolismo , Hipotálamo/efeitos dos fármacos , Ocitocina/metabolismo , Dor/metabolismo , Núcleo Supraóptico/efeitos dos fármacos , Núcleo Supraóptico/metabolismo , Animais , Ácido Glutâmico/farmacologia , Injeções Intraventriculares , Masculino , Radioimunoensaio , Ratos , Ratos Sprague-DawleyRESUMO
Arginine vasopressin (AVP), which is synthesized and secreted in the hypothalamic paraventricular nucleus (PVN), is the most important bioactive substance in the pain modulation. Our pervious study had shown that AVP plays an important role in pain modulation in caudate nucleus (CdN). The experiment was designed to investigate the source of AVP in CdN by the nucleus push-pull perfusion and radioimmunoassay. The results showed that: (1) pain stimulation increased the AVP concentration in the CdN perfusion liquid, (2) PVN decreased the effect of pain stimulation which was stronger in both sides than in one side of PVN cauterization; and (3) L-glutamate sodium would excited the PVN neurons by the PVN microinjection that could increase the AVP concentration in the CdN perfusion liquid. The data suggested that AVP in the CdN might come from the PVN in the pain process, i.e., AVP in the PVN might be transferred to the CdN to participate in the pain modulation.
Assuntos
Arginina Vasopressina/metabolismo , Núcleo Caudado/metabolismo , Dor/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Animais , Arginina Vasopressina/farmacologia , Núcleo Caudado/efeitos dos fármacos , Masculino , Dor/fisiopatologia , Medição da Dor , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Ratos , Ratos Sprague-DawleyRESUMO
Our previous studies have demonstrated that oxytocin (OXT) in the central nervous system plays a role in pain modulation. Many studies have found that caudate nucleus (CdN) enriches OXT and OXT receptors by the methods of historadioautograph and gene expression. The communication was designed to investigate OXT effect in the rat CdN on pain modulation. The results showed that (1) intra-CdN microinjection of OXT receptor antagonist, desGly-NH(2), d(CH(2))(5)[D-Tyr(2), Thr-sup-4]OVT decreased the pain threshold, whereas the local administration of OXT increased the pain threshold in a dose-dependent manner; (2) OXT receptor antagonist can attenuate the analgesic role induced intra-CdN administration of OXT; and (3) pain stimulation could increase OXT concentration in the CdN perfusion liquid. The data suggested that OXT in the CdN was involved in this pain process via OXT receptors.
Assuntos
Núcleo Caudado/efeitos dos fármacos , Ocitocina/farmacologia , Limiar da Dor/efeitos dos fármacos , Dor/metabolismo , Analgésicos/farmacologia , Animais , Núcleo Caudado/fisiologia , Masculino , Microinjeções , Medição da Dor , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , Receptores de Ocitocina/antagonistas & inibidores , Receptores de Ocitocina/metabolismoRESUMO
Studies have demonstrated that oxytocin (OXT) plays important roles in pain modulation in the central nervous system, and there are OXT receptors in the periaqueductal grey (PAG). The experiment was designed to investigate the effect of OXT in the PAG on antinociception. The results showed that (1) intra-PAG injection of OXT increased the pain threshold, whereas the local administration of the high specific OXT receptor antagonist, desGly-NH(2), d(CH(2))(5)[D-Tyr(2), Thr-sup-4]OVT decreased the pain threshold in a dose-dependent manner; (2) Pain stimulation could elevate OXT concentration in the PAG perfusion liquid. The data suggested that OXT in the PAG was involved in the antinociceptive process through the OXT receptor.
Assuntos
Ocitocina/fisiologia , Dor/metabolismo , Substância Cinzenta Periaquedutal/metabolismo , Animais , Masculino , Microinjeções , Ornipressina/análogos & derivados , Ornipressina/farmacologia , Ocitocina/metabolismo , Dor/fisiopatologia , Medição da Dor , Limiar da Dor , Ratos , Ratos Sprague-Dawley , Receptores de Ocitocina/antagonistas & inibidoresRESUMO
The pharmacokinetics (PK) of ordinary tablets and sustained release capsules of diltiazem hydrochloride in human clinical trials had been studied. The PK of diltiazem hydrochloride delay-onset sustained-release pellet capsules, a new dosage form, has not been reported, although it is very important to clinical use. In this paper, we investigated the PK of diltiazem hydrochloride delay-onset sustained-release pellet capsules and the food influence in Chinese healthy volunteers. The PK parameters indicated that the diltiazem hydrochloride delay-onset sustained-release pellet capsules appeared marked characteristics of delayed and controlled release. An opened-label, randomized and parallel clinical trial was conducted in 36 Chinese healthy volunteers with single oral dose (90 mg, 180 mg or 270 mg) and a multiple oral dose (90 mg d-1×6 d) administration. The effect of food on the PK of one single oral dose (360 mg) was investigated in 24 healthy Chinese volunteers. Plasma diltiazem concentration was determined by reversed-phase high-performance liquid chromatography (RP-HPLC) and the main pharmacokinetic parameters were analyzed by PKSolver (Ver 2.0). All clinical studies were conducted in the Clinical Pharmacological Center (No. JDX1999064) of Xiangya Hospital Affiliated Central South University, China. The PK parameters suggested that the new formulation had marked characteristics of delayed and controlled release of diltiazem, and food intake did not alter significantly diltiazem pharmacokinetic parameters.
Embora a farmacocinética (PK) do cloridrato de diltiazem nas formas de comprimidos de liberação imediata e cápsulas de liberação modificada em ensaios clínicos já tenha sido relatada, a pesquisa da PK do cloridrato de diltiazem na forma de cápsulas com peletes de liberação retardada e sustentada ainda é muito importante. Neste trabalho, propusemos avaliar a farmacocinética do cloridrato de diltiazem administrado através desta nova forma farmacêutica em voluntários chineses sadios, assim como a influência da ingestão de alimentos neste perfil farmacocinético. Foi realizado um ensaio clínico aberto, randomizado e paralelo em 36 voluntários, que receberam dose oral única de 90 mg, 180 mg ou 270 mg e dose múltiplas (90 mg/d × 6 d) pela mesma via de administração. Para avaliar o efeito da ingestão de alimentos sobre a PK do diltiazem foi realizada a administração de dose única (360 mg) em 24 voluntários chineses sadios. A concentração plasmática do diltiazem foi determinada por Cromatografia Liquida de Alta Eficiência em fase reversa (CLAE-FR) e os principais parâmetros farmacocinéticos foram analisados através do emprego do software PKSolver (Ver 2.0). O ensaio de farmacocinética clínica foi conduzido na clínica Pharmacological Center (No.JDX1999064) do Hospital de Xiangya, Central South University, China. Os parâmetros PK obtidos indicaram que a nova formulação de cápsulas de liberação retardada e sustentada de cloridrato de diltiazem possue marcantes características de liberação retardada e controlada do fármaco.