Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Filtros adicionais











País/Região como assunto
Intervalo de ano
1.
Int J Nanomedicine ; 14: 1489-1501, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30880960

RESUMO

Purpose: Antiangiogenic drugs usually have short-acting efficacy and poor treatment compliance. The purpose of this study was to determine whether mesoporous silica nanoparticles (MSNs) could be utilized as a nanodrug delivery system for improving antiangiogenic therapy. Materials and methods: MSN-encapsulated bevacizumab nanoparticles were prepared by the nanocasting strategy and characterized by Fourier transform infrared, transmission electron microscopy, and Brunauer-Emmett-Teller method. Encapsulation efficiency and drug loading efficiency of MSN-encapsulated bevacizumab nanoparticles were calculated. The pharmacokinetics, cytotoxicity, and tissue toxicity were evaluated in vitro and in vivo. The antiangiogenic effects of MSN-bevacizumab nanoparticles were evaluated in vitro and in vivo. Results: MSN encapsulation could prolong the residency of bevacizumab in vitreous/aqueous humor and maintain the long-lasting drug concentration. MSN-encapsulated bevacizumab nanoparticles did not show any obvious cytotoxicity and tissue toxicity. MSN-encapsulated bevacizumab nanoparticles were more effective than bevacizumab in suppressing vascular endothelial growth factor-induced endothelial cell proliferation, migration, and tube formation in vitro. MSN-encapsulated bevacizumab nanoparticles showed sustained inhibitory effects on corneal neovascularization and retinal neovascularization in vivo. Conclusion: This study provides a novel strategy of encapsulating bevacizumab to protect and deliver it, which could increase the time between administration and formulation shelf-life. MSN-encapsulated bevacizumab is a promising drug delivery alternative of antiangiogenic therapy.


Assuntos
Inibidores da Angiogênese/farmacologia , Bevacizumab/farmacologia , Neovascularização da Córnea/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Nanopartículas/administração & dosagem , Dióxido de Silício/química , Inibidores da Angiogênese/administração & dosagem , Animais , Bevacizumab/administração & dosagem , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Portadores de Fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/química , Porosidade
2.
Opt Express ; 26(20): 25602-25610, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30469659

RESUMO

Waveguide crossing is an important integrated photonic component that will be routinely used for high-density and large-scale photonic integrated circuits, such as optical switches and routers. Several techniques have been reported in achieving high performance waveguide crossings on a silicon-on-insulator photonic platform, i.e., low-loss and low-crosstalk waveguide crossings based on multimode interference, bi-layer tapering, optical transformation, metamaterials, and subwavelength gratings. Until recently, not much attention has been given to the reduction of the footprint of waveguide crossings. Here we experimentally demonstrate an ultra-compact waveguide crossing on silicon photonic platform with a footprint only ~1 × 1 µm2. Our simulations show that it has a low insertion loss (< 0.175 dB) and low crosstalk (< -37dB) across the whole C-band, while the fabricated one has an insertion loss < 0.28 dB and crosstalk around -30 dB for the C-band.

3.
Theranostics ; 8(17): 4695-4709, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30279732

RESUMO

VEGF binding to VEGFR2 leads to VEGFR2 endocytosis and downstream signaling activation to promote angiogenesis. Methods: Using genetic strategies, we tested the requirement of α subunits of heterotrimeric G proteins (Gαi1/3) in the process. Results: Gαi1/3 are located in the VEGFR2 endocytosis complex (VEGFR2-Ephrin-B2-Dab2-PAR-3), where they are required for VEGFR2 endocytosis and downstream signaling transduction. Gαi1/3 knockdown, knockout or dominant negative mutation inhibited VEGF-induced VEGFR2 endocytosis, and downstream Akt-mTOR and Erk-MAPK activation. Functional studies show that Gαi1/3 shRNA inhibited VEGF-induced proliferation, invasion, migration and vessel-like tube formation of HUVECs. In vivo, Gαi1/3 shRNA lentivirus inhibited alkali burn-induced neovascularization in mouse cornea. Further, oxygen-induced retinopathy (OIR)-induced retinal neovascularization was inhibited by intravitreal injection of Gαi1/3 shRNA lentivirus. Moreover, in vivo angiogenesis by alkali burn and OIR was significantly attenuated in Gαi1/3 double knockout mice. Significantly, Gαi1/3 proteins are upregulated in proliferative retinal tissues of proliferative diabetic retinopathy (PDR) patients. Conclusion: These results provide mechanistic insights into the critical role played by Gαi1/3 proteins in VEGF-induced VEGFR2 endocytosis, signaling and angiogenesis.

4.
Biomed Pharmacother ; 107: 1056-1063, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30257317

RESUMO

Antibody-based therapy is an effective strategy for treating ocular angiogenesis. However, short-acting efficacy and poor treatment compliance usually occurs in clinical practices. Thus, it is required to develop a drug delivery system to improve the bioavailability and decrease the toxicity of anti-angiogenic antibody. Bevacizumab is a recombinant humanized monoclonal antibody against vascular endothelial growth factor (VEGF). In this study, bevacizumab was encapsulated into poly (lactide-co-glycolide) (PLGA) nanoparticles. PLGA encapsulation could prolong the residency of bevacizumab in the vitreous and aqueous humor and produce long-lasting drug concentrations. Bevacizumab-encapsulated PLGA had no significant cytotoxicity and tissue toxicity effect in vitro and in vivo. In vitro studies showed that bevacizumab-encapsulated PLGA was more effective than bevacizumab in inhibiting VEGF-mediated endothelial cell proliferation, migration and tube formation. In vivo studies showed that bevacizumab-encapsulated PLGA enhanced the anti-angiogenic efficiency of bevacizumab for treating corneal neovascularization and retinal neovascularization. Thus, bevacizumab-encapsulated PLGA could increase the bioavailability and decrease the toxicity of bevacizumab during ocular angiogenesis therapy.

5.
J Cardiovasc Nurs ; 33(6): 509-517, 2018 Nov/Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29901484

RESUMO

BACKGROUND AND OBJECTIVE: The health behaviors of hypertensive stroke patients in China are not satisfactory. In this study, we tested the effect of a Health Belief Model Comprehensive Reminder System on health behaviors and blood pressure control in hypertensive ischemic stroke patients after occurrence and hospital discharge. METHODS: A randomized, parallel-group, assessor-blinded experimental design yielded participation of 174 hospitalized hypertensive ischemic stroke patients. The intervention consisted of face-to-face and telephone health belief education, a patient calendar handbook, and weekly automated short-message services. Data were collected at baseline and 3 months after discharge. RESULTS: Three months after discharge, the intervention group showed statistically, significantly better health behaviors for physical activity, nutrition, low-salt diet, and medication adherence. The intervention group also had statistically, significantly decreased systolic blood pressure and increased blood pressure control rate. Smoking and alcohol use behaviors were not affected. CONCLUSION: At 3 months, use of the Comprehensive Reminder System based on the Health Belief Model, yielded improvement in most health behaviors and blood pressure control in hypertensive ischemic stroke patients. Continued implementation of this intervention protocol is warranted to determine the long-term effect. Smoking and alcohol use behaviors need to be targeted with a different intervention.

6.
Chin Med J (Engl) ; 131(8): 956-965, 2018 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-29664057

RESUMO

Background: Remote ischemic postconditioning (RIPostC) appears to protect distant organs from ischemia-reperfusion injury (IRI). However, cerebral protection results have remained inconclusive. In the present study, a meta-analysis was performed to compare stroke patients with and without RIPostC. Methods: CNKI, WanFang, VIP, CBM, PubMed, and Cochrane Library databases were searched up to July 2016. Data were analyzed using both fixed-effects and random-effects models by Review Manager. For each outcome, risk ratio (RR) and mean difference (MD) with 95% confidence interval (CI) were calculated. Results: A total of 13 randomized controlled trials that enrolled a total of 794 study participants who suffered from or are at risk for brain IRI were selected. Compared with controls, RIPostC significantly reduced the recurrence of stroke or transient ischemic attacks (RR = 0.37; 95% CI: 0.26-0.55; P < 0.00001). Moreover, it can reduce the levels of the National Institutes of Health Stroke Scale score (MD: 1.96; 95% CI: 2.18-1.75; P < 0.00001), modified Rankin Scale score (MD: 0.73; 95% CI: 1.20-0.25; P = 0.00300), and high-sensitivity C-reactive protein (MD: 4.17; 95% CI: 4.71-3.62; P < 0.00001) between the two groups. There was no side effect of RIPostC using tourniquet cuff around the limb on ischemic stroke treating based on different intervention duration. Conclusion: The present meta-analysis suggests that RIPostC might offer cerebral protection for stroke patients suffering from or are at risk of brain IRI.


Assuntos
Isquemia Encefálica/prevenção & controle , Pós-Condicionamento Isquêmico/métodos , Acidente Vascular Cerebral/prevenção & controle , Humanos , Ataque Isquêmico Transitório/prevenção & controle , Ataque Isquêmico Transitório/terapia , Ensaios Clínicos Controlados Aleatórios como Assunto
7.
FASEB J ; 32(7): 3782-3791, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29465315

RESUMO

VEGF-induced neovascularization plays a pivotal role in corneal neovascularization (CoNV). The current study investigated the potential effect of ginsenoside Rh2 (GRh2) on neovascularization. In HUVECs, pretreatment with GRh2 largely attenuated VEGF-induced cell proliferation, migration, and vessel-like tube formation in vitro. At the molecular level, GRh2 disrupted VEGF-induced VEGF receptor 2 (VEGFR2)-Grb-2-associated binder 1 (Gab1) association in HUVECs, causing inactivation of downstream AKT and ERK signaling. Gab1 knockdown (by targeted short hairpin RNA) similarly inhibited HUVEC proliferation and migration. Notably, GRh2 was ineffective against VEGF in Gab1-silenced HUVECs. In a mouse cornea alkali burn model, GRh2 eyedrops inhibited alkali-induced neovascularization and inflammatory cell infiltrations in the cornea. Furthermore, alkali-induced corneal expression of mRNAs/long noncoding RNAs in cornea were largely attenuated by GRh2. Overall, GRh2 inhibits VEGF-induced angiogenic effect via inhibiting VEGFR2-Gab1 signaling in vitro. It also alleviates angiogenic and inflammatory responses in alkali burn-treated mouse corneas.-Zhang, X.-P., Li, K.-R., Yu, Q., Yao, M.-D., Ge, H.-M., Li, X.-M., Jiang, Q., Yao, J., Cao, C. Ginsenoside Rh2 inhibits vascular endothelial growth factor-induced corneal neovascularization.

8.
Chin Med J (Engl) ; 130(6): 652-658, 2017 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-28303846

RESUMO

BACKGROUND: Renal function is associated with mortality and functional disabilities in stroke patients, and impaired autonomic function is common in stroke, but little is known regarding its effects on stroke patients with renal dysfunction. This study sought to evaluate the association between autonomic function and stroke in patients with renal dysfunction. METHODS: This study comprised 232 patients with acute ischemic stroke consecutively enrolled from February 2013 to November 2014 at Guangdong Provincial Hospital of Chinese Medicine in China. All patients recruited underwent laboratory evaluation and 24 h Holter electrocardiography (ECG). Autonomic function was measured based on the heart rate variability (HRV) using 24 h Holter ECG. Renal damage was assessed through the estimated glomerular filtration rate (eGFR), and stroke severity was rated according to the National Institutes of Health Stroke Scale (NIHSS). The Barthel index and modified Rankin score were also determined following admission. All the clinical covariates that could potentially affect autonomic outcome variables were adjusted with linear regression. RESULTS: In the patients with a mild or moderate decreased eGFR, the values for the standard deviation of the averaged normal-to-normal RR interval (SDANN) index (P = 0.022), very low frequency (VLF) (P = 0.043), low frequency (LF) (P = 0.023), and ratio of low-to-high frequency power (LF/HF) (P = 0.001) were significantly lower than those in the patients with a normal eGFR. A multinomial linear regression indicated that eGFR (t = 2.47, P = 0.014), gender (t = -3.60, P < 0.001), and a history of hypertension (t = -2.65, P = 0.008) were the risk factors of LF/HF; the NIHSS score (SDANN index: t = -3.83, P < 0.001; VLF: t = -3.07, P = 0.002; LF: t = -2.79, P = 0.006) and a history of diabetes (SDANN index: t = -3.58, P < 0.001; VLF: t = -2.54, P = 0.012; LF: t = -2.87, P = 0.004) were independent factors for the SDANN index, VLF, and LF; the Oxfordshire Community Stroke Project (t = -2.38, P = 0.018) was related to the SDANN index. CONCLUSIONS: Autonomic dysfunction is aggravated with the progression of eGFR stage in patients with acute ischemic stroke; the eGFR is an independent factor of LF/HF in the adjusted models. Stroke severity and a history of diabetes are more significantly associated with HRV in patients with acute ischemic stroke at different stages of renal dysfunction.


Assuntos
Frequência Cardíaca/fisiologia , Rim/patologia , Acidente Vascular Cerebral/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Taxa de Filtração Glomerular/fisiologia , Humanos , Rim/fisiopatologia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Estudos Observacionais como Assunto
9.
J Adv Nurs ; 72(12): 3195-3206, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27508314

RESUMO

AIM: The aim of this study was to determine whether the Comprehensive Reminder System based on the Health Belief Model improves health belief, health behaviours, medication adherence and blood pressure control as a means of decreasing the rate of stroke recurrence among hypertensive ischaemic stroke. BACKGROUND: Hypertensive patients having experienced recent ischaemic strokes are at high risk for stroke recurrence. Several trials attempted to improve secondary stroke prevention via patient education, however, patient outcomes remained poor. Long-term follow-up studies regarding secondary stroke prevention are limited. DESIGN: A multi-centre, 12-month, assessor-blinded, parallel-group, randomized controlled longitudinal trial. METHODS: Hypertensive patients having experienced an ischaemic stroke are the target population. The intervention consists of health belief education, a calendar handbook, a weekly automated short-message service and four telephone follow-up interviews. Outcomes will be assessed at baseline and at 3, 6 and 12 months following discharge. The primary outcome is blood pressure control. The secondary outcomes include health belief, health behaviours and medication adherence. The clinical endpoint is the rate of stroke recurrence. DISCUSSION: Although many efforts to improve secondary stroke prevention have been undertaken, research indicates that improvements remain possible and warranted. This research protocol based on the Health Belief Model will improve our understanding of stroke education and transitional care needed in China and with the world-wide target population.


Assuntos
Hipertensão/complicações , Sistemas de Alerta , Prevenção Secundária , Acidente Vascular Cerebral/prevenção & controle , China , Protocolos Clínicos , Humanos
10.
J Stroke Cerebrovasc Dis ; 25(9): 2259-70, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27371106

RESUMO

BACKGROUND: Adopting healthy behaviors is critical for secondary stroke prevention, but many patients fail to follow national guidelines regarding diet, exercise, and abstinence from risk factors. Compliance often decreases with time after hospital discharge, yet few studies have examined programs promoting long-term adherence to health behaviors. Goal setting and telephone follow-up have been proven to be effective in other areas of medicine, so this study evaluated the effectiveness of a guideline-based, goal-setting telephone follow-up program for patients with ischemic stroke. METHODS: This was a multicenter, assessor-blinded, parallel-group, randomized controlled trial. Ninety-one stroke patients were randomized to either a control group or an intervention group. Intervention consisted of predischarge education and 3 goal-setting follow-up sessions conducted by phone. Data were collected at baseline and during the third and sixth months after hospital discharge. RESULTS: Six months after discharge, patients in the intervention group exhibited significantly higher medication adherence than patients in the control group. There were no statistically significant differences in physical activity, nutrition, low-salt diet adherence, blood pressure monitoring, smoking abstinence, unhealthy use of alcohol, and modified Rankin Scale (mRS) scores between the 2 groups. CONCLUSIONS: Goal-setting telephone follow-up intervention for ischemic stroke patients is feasible and leads to improved medication adherence. However, the lack of group differences in other health behavior subcategories and in themRS score indicates a need for more effective intervention strategies to help patients reach guideline-recommended targets.


Assuntos
Metas , Comportamentos Relacionados com a Saúde , Acidente Vascular Cerebral/psicologia , Acidente Vascular Cerebral/terapia , Atividades Cotidianas , Adulto , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Seguimentos , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Neuroimagem , Avaliação de Resultados (Cuidados de Saúde) , Cooperação do Paciente , Fatores de Risco , Telefone
11.
J Cardiovasc Nurs ; 29(2): E1-9, 2014 Mar-Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23388703

RESUMO

BACKGROUND AND OBJECTIVES: Individuals with hypertension are at risk of stroke, and patients with stroke histories are at risk of experiencing another stroke. At this time, however, only a few studies have reported on stroke prevention knowledge and health behaviors among hypertensive patients who have had an initial stroke. The purpose of this study was to determine stroke prevention knowledge and health behaviors and to analyze the association between these 2 variables among hypertensive stroke patients who have had an initial stroke. SUBJECTS AND METHODS: With the use of a descriptive correlational design, a sample of 112 hypertensive stroke patients was recruited from the departments of neurology of 3 hospitals in Guangzhou, China. Each patient completed 2 reliable, validated questionnaires, the Stroke Prevention Knowledge Questionnaire and the Health Promoting Lifestyle Profile II. Data were collected during patients' hospital admission for stroke, within 2 days of stroke onset, and before they received stroke education. Pearson correlation coefficient was used to examine the correlations between the study variables. Multiple stepwise regression analysis was used to predict both the level of knowledge relating to stroke prevention and health behaviors. RESULTS AND CONCLUSIONS: The participants showed a relatively low level of stroke prevention knowledge and a moderate level of engagement in healthy behaviors. Pearson correlation coefficient between these 2 variables was 0.423 (P < .001). The results of multiple regression analysis showed that stroke prevention knowledge was positively influenced by education level; health behaviors were positively influenced by both gender and stroke prevention knowledge. Findings suggest that male hypertensive patients and those with a lower education level need targeted stroke education. Because knowledge was unrelated to behavior with respect to smoking, alcohol use, and low-salt diet, behavioral interventions should be explored to address these important risk factors among patients at risk for stroke.


Assuntos
Comportamentos Relacionados com a Saúde , Conhecimentos, Atitudes e Prática em Saúde , Acidente Vascular Cerebral/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , China , Feminino , Promoção da Saúde , Humanos , Hipertensão/complicações , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/complicações
12.
Ying Yong Sheng Tai Xue Bao ; 24(4): 915-20, 2013 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-23898645

RESUMO

Aiming at the delayed sowing of winter wheat induced by the drought and water logging often occurred in Huanghuai Plains of China, six sowing dates (15 October, normal sowing; 30 October, moderate delay; 15 November, delay; 30 November, seriously delay; 15 February, early spring sowing; and 1 March, spring sowing) were designed to investigate the effects of different sowing dates on the shoot type morphology and growth characteristics of winter wheat. With the delay of sowing date, the winter wheat grew and developed faster, and the growing period of the wheat sown in early spring and spring was 115-130 days shorter than that with normal sowing. As compared with those of the wheat with normal sowing, the shoot height, spike number per unit area, and productive spikelets per unit ear of the wheat sown delayed had a decrease, leaf position and canopy moved down, and leaf area reduced. When the sowing was delayed from the date 15 October (normal sowing) to 1 March (spring sowing), the harvest index increased from 0.46 to 0.53. Delaying sowing date also resulted in the significant reduction of grain yield, with the maximum decrement as high as 43. 6%. The spring-sown winter wheat not going through vernalization could still form yield.


Assuntos
Agricultura/métodos , Biomassa , Brotos de Planta/crescimento & desenvolvimento , Triticum/crescimento & desenvolvimento , China , Estações do Ano , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA