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1.
Biochem Biophys Res Commun ; 473(1): 133-139, 2016 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-26996127

RESUMO

Peri-prosthetic osteolysis and the consequent aseptic loosening constitute the most common reason for total joint arthroplasty failure and surgical revision. Although numerous studies suggest that pro-inflammatory cytokines induced by wear particles is involved in the pathological process of aseptic loosening, the underlying mechanism linking wear particles to pro-inflammatory cytokines remains to be illustrated. In the present study, we investigated the effect of autophagy on TNF-α secretion induced by TiAl6V4 particles (TiPs) in macrophages and in a calvarial resorption animal model. Our study demonstrated that TiPs activated autophage in macrophages and particle-induced osteolysis animal models as well as periprosthetic membranes of patients with aseptic loosening. The autophagy inhibitor 3-MA (3-methyladenine) could dramatically reduce TiPs-induced TNF-α expression both in macrophages and in membranes from animal models. Furthermore, inhibition of autophagy with 3-MA ameliorated the severity of osteolysis in PIO animal models. Collectively, these results suggest that autophagy plays a key role in TiPs-induced osteolysis by promoting TNF-α expression and that blocking autophagy may represent a potential therapeutic approach for treating particle-induced peri-implant osteolysis.


Assuntos
Autofagia , Macrófagos/metabolismo , Osteólise/induzido quimicamente , Titânio/química , Fator de Necrose Tumoral alfa/metabolismo , Adenina/análogos & derivados , Adenina/química , Idoso , Idoso de 80 Anos ou mais , Ligas , Animais , Modelos Animais de Doenças , Feminino , Humanos , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Falha de Prótese , Titânio/efeitos adversos , Regulação para Cima , Microtomografia por Raio-X , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
2.
Drug Dev Ind Pharm ; 40(7): 929-36, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23614872

RESUMO

In order to improve the in vitro dissolution rate and in vivo oral bioavailability of the poorly water soluble drug, felodipine (FELO), the wet-milling process was employed involving co-grinding with HPMC E5 and the in vitro release rate as investigated. After solidification by spray drying or freeze drying, the microsized powders were characterized in terms of their size, morphology, and in vitro dissolution rate. The oral bioavailability of this dry powder for suspension was evaluated in rats. After milling with 8% HPMC E5 and freeze drying, the powder mixture had an average particle size of 2.249 ± 1.497 µm and displayed an excellent dissolution rate of up to 93.2% within 10 minutes. DSC and PXRD investigations confirmed the absence of any crystal transformation during the wet-milling process. Using two different solidification methods, powders were stable for 6 months with regard to their in vitro dissolution rate. Significantly improved bioavailability was obtained for the wet-milled suspension before solidification and freeze dried powders with 6.8- (p < 0.001) and 3.6-fold (p < 0.01) increases, respectively, compared with that of the un-milled FELO. Also, no marked difference (p > 0.05) in bioavailability was seen for the spray dried powders. These effects suggest that the solidification method plays an important role in modifying the bioavailability of FELO after wet milling. Consequently, wet-milling is an effective technique to enhance the bioavailability of FELO and to maintain these benefits, freeze-drying is a feasible approach to solidifying the wet-milled suspension for industrial applications.


Assuntos
Bloqueadores dos Canais de Cálcio/química , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Felodipino/química , Derivados da Hipromelose/química , Animais , Disponibilidade Biológica , Bloqueadores dos Canais de Cálcio/administração & dosagem , Bloqueadores dos Canais de Cálcio/sangue , Bloqueadores dos Canais de Cálcio/farmacocinética , Varredura Diferencial de Calorimetria , Liberação Controlada de Fármacos , Felodipino/administração & dosagem , Felodipino/sangue , Felodipino/farmacocinética , Masculino , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Transição de Fase , Pós , Ratos , Solubilidade , Propriedades de Superfície , Difração de Raios X
3.
J Craniomaxillofac Surg ; 52(2): 222-227, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38195299

RESUMO

This study aims to compare the effects of mandibular distraction osteogenesis (MDO) and bone grafting on the facial symmetry of children with Pruzansky-Kaban type IIB and III craniofacial microsomia (CFM). Medical records and three-dimensional computed tomography (3D-CT) data of CFM patients who had primarily undergone MDO and bone grafting were collected. A retrospective analysis of pre-and post-operative 3D imaging data was conducted to compare the improvement rate in facial symmetry between the two groups based on occlusal cant, affected/unaffected ramus height ratio and chin point deviation. The data were tested for normality using the Shapiro-Wilk test. When the data followed a normal distribution, a paired sample t-test was employed for the comparison between preoperative and postoperative data. When the data did not follow a normal distribution, the Wilcoxon signed-rank test for paired samples was used for preoperative and postoperative comparison. The study included 18 children with type IIB and III CFM, 11 in the MDO group and 7 in the bone grafting group. In the MDO group, postoperative Gn-FH and Gn-Cor distances increased significantly, whereas the postoperative Gn-Mid distance decreased significantly. Occlusal cant decreased significantly and ramus height affected/unaffected ratio increased significantly after MDO. In the bone graft group, there was no statistically significant difference in the postoperative ratios of chin deviation, occlusal cant, and ramus height affected/unaffected compared to the preoperative values. Compared to bone grafting, MDO can significantly enhance ramus height ratio, level occlusal plane, and centralize the chin point among patients with CFM. Furthermore, MDO achieves superior enhancements in facial symmetry.


Assuntos
Síndrome de Goldenhar , Osteogênese por Distração , Humanos , Criança , Síndrome de Goldenhar/diagnóstico por imagem , Síndrome de Goldenhar/cirurgia , Osteogênese por Distração/métodos , Transplante Ósseo/métodos , Estudos Retrospectivos , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Tomografia Computadorizada por Raios X
4.
Analyst ; 138(9): 2613-9, 2013 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-23478568

RESUMO

In this work, we demonstrate the immunocapture and on-line fluorescence immunoassay of protein and virus based on porous polymer monoliths (PPM) in microfluidic devices. Poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) [poly(GMA-co-EGDMA)] monoliths were successfully synthesized in the polydimethylsiloxane (PDMS) microfluidic channels by in situ UV-initiated free radical polymerization. After surface modification, PPM provides a high-surface area and specific affinity 3D substrate for immunoassays. Combining with well controlled microfluidic devices, the direct immunoassay of IgG and sandwich immunoassay of inactivated H1N1 influenza virus using 5 µL sample has been accomplished, with detection limits of 4 ng mL(-1) and less than 10 pg mL(-1), respectively. The enhanced detection sensitivity is due to both high surface area of PPM and flow-through design. The detection time was obviously decreased mainly due to the shortened diffusion distance and improved convective mass transfer inside the monolith, which accelerates the reaction kinetics between antigen and antibody. This work provides a novel microfluidic immunoassay platform with high efficiency thereby enabling fast and sensitive immunoassay.


Assuntos
Dimetilpolisiloxanos/química , Imunoensaio/instrumentação , Imunoglobulina G/análise , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/virologia , Técnicas Analíticas Microfluídicas/instrumentação , Desenho de Equipamento , Etilenoglicóis , Humanos , Vírus da Influenza A Subtipo H1N1/imunologia , Metacrilatos/síntese química , Metacrilatos/química , Polimerização , Porosidade , Sensibilidade e Especificidade
5.
Bioresour Technol ; 380: 129074, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37088430

RESUMO

Using wastepaper as external carbon sources is an optional way to achieve total nitrogen removal faced with low carbon to nitrogen ratio municipal sewage. Most of studies have primarily focused on using cellulose-rich wastes establishing the separate denitrification units to achieve in-situ fermentation, which can cause blockages and prolong the process chain. In response, a novel in-situ fermentation wastepaper-flora slow-release carbon source (IF-WF) was proposed using in the original denitrification unit. IF-WF could be efficiently utilized in situ and the denitrification rate increased with the increase of nitrate nitrogen. The fermentation products were highly available, but internal acidification of IF-WF inhibited fermentation. Moreover, IF-WF limited the growth of polysaccharides in the extracellular polymeric substances of denitrified sludge. IF-WF finally formed the structure dominated by nitrate-reduction bacteria outside and cellulose-degrading bacteria inside. These results provide guidance for understanding the mechanism of IF-WF for in-situ fermentation to promote nitrogen removal.


Assuntos
Reatores Biológicos , Desnitrificação , Fermentação , Eliminação de Resíduos Líquidos , Nitratos , Carbono , Esgotos/química , Compostos Orgânicos , Nitrogênio , Celulose
6.
J Knee Surg ; 35(14): 1577-1586, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33992032

RESUMO

Pneumatic tourniquets are used in total knee arthroplasty (TKA) for surgical field visualization and improved cementation; however, their use is controversial. This study aimed to assess the effects of tourniquet application on faster recovery post-TKA. Our hypothesis was that inflammation and limb function would be similar with different tourniquet applications. A prospective randomized double-blinded trial assessed tourniquets effects on postoperative pain, swelling, and early outcome in TKA. In present study, 50 TKAs were enrolled in each group as follows: full course (FC), cementation through closure (CTC), and no tourniquet (NT), CTC as treatment group while FC and NT as control groups. Topical blood samples of 3 mL from the joint cavity and drainage bags were obtained at special time point. At last, all samples such as tumor necrosis factor-a (TNF-a), C-C motif chemokine ligand 2 (CCL2), pentraxin 3 (PTX3), prostaglandin E2 (PGE2), superoxide dismutase 1 (SOD1), and myoglobin (Mb) were detected by ELISA. Active and passive range of motion (ROM) values, pain score by the visual analog scale (VAS), change of thigh circumference were recorded at special time point as well. In topical blood, the change of inflammatory factors, such as TNF-a, PTX3, CCL2, PGE2, SOD1, and Mb, was lower in CTC and NT groups than in FC group (p < 0.01 and 0.05). Although VAS and ROM were comparable preoperatively in three groups (p > 0.05), the perimeter growth rate was lower, pain scores (VAS) were reduced, and ROM values were improved in CTC and NT groups compared with FC group at T4, T5, and T6 postoperatively (p < 0.01 and 0.05). Improved therapeutic outcome was observed in the CTC group, indicating patients should routinely undergo TKA with cementation through closure tourniquet application.


Assuntos
Artroplastia do Joelho , Humanos , Cimentação , Estudos Prospectivos , Dinoprostona , Superóxido Dismutase-1 , Perda Sanguínea Cirúrgica , Dor Pós-Operatória/etiologia , Isquemia , Reperfusão , Torniquetes , Amplitude de Movimento Articular
7.
J Control Release ; 333: 269-282, 2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-33798664

RESUMO

Periodontitis is a chronic inflammation of the soft tissue surrounding and supporting the teeth, which causes periodontal structural damage, alveolar bone resorption, and even tooth loss. Its prevalence is very high, with nearly 60% of the global population affected. Hence, periodontitis is an important public health concern, and the development of effective healing treatments for oral diseases is a major target of the health sciences. Currently, the application of local drug delivery systems (LDDS) as an adjunctive therapy to scaling and root planning (SRP) in periodontitis is a promising strategy, giving higher efficacy and fewer side effects by controlling drug release. The cornerstone of successful periodontitis therapy is to select an appropriate bioactive agent and route of administration. In this context, this review highlights applications of LDDS with different properties in the treatment of periodontitis with or without systemic diseases, in order to reveal existing challenges and future research directions.


Assuntos
Periodontite , Sistemas de Liberação de Medicamentos , Humanos , Periodontite/tratamento farmacológico
8.
Shanghai Kou Qiang Yi Xue ; 29(3): 293-297, 2020 Jun.
Artigo em Zh | MEDLINE | ID: mdl-33043347

RESUMO

PURPOSE: To explore the efficacy and safety of ornidazole combined with periodontal tissue regeneration in the treatment of periodontitis. METHODS: From March 2018 to March 2019, 100 patients with periodontitis who received treatment in the Stomatological Hospital Affiliated to the School of Medicine of Nanjing University were selected and randomly divided into the regeneration group and combined treatment group with 50 patients in each group. Patients in the regeneration group received periodontal tissue regeneration treatment, while patients in the combined treatment group received ornidazole combined periodontal tissue regeneration treatment. Related periodontal indexes including periodontal probing depth(PPD), periodontal attachment level(PAL), tooth mobility degree(MD) were measured, serum malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (gsh-px) and interleukin 10 (IL-10) and interleukin 4 (IL-4), c-reactive protein(CRP) level and immune globulin level were detected before and after treatment, the therapeutic effects and complications were recorded and compared. SPSS 21.0 software package was used for statistical analysis of the data. RESULTS: After treatment, PPD, PAL and MD levels in the combined treatment groups were significantly lower than those in the regenerative group (P<0.05). Serum MDA level in the combined treatment group was significantly lower than that in the regenerative group, SOD and gsh-px levels were significantly higher than that in the regenerative group(P<0.05). The serum levels of IgA, IgM, IgG, IgE, IL-10, IL-4 and CRP in the combined treatment group were significantly lower than those in the regenerative treatment group (P<0.05). The total effective rate of the combined treatment group was significantly higher than that of the regenerative treatment group, and the incidence of complications was significantly lower than that of the regenerative group(P<0.05). CONCLUSIONS: Ornidazole combined with periodontal tissue regeneration can improve the level of periodontal index, alleviate oxidative stress injury, improve immune function, inhibit inflammation, and has a significant therapeutic effect with high safety.


Assuntos
Metronidazol , Periodontite , Terapia Combinada , Humanos , Metronidazol/efeitos adversos , Índice Periodontal , Periodontite/tratamento farmacológico , Periodonto
9.
Drug Deliv ; 27(1): 938-952, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32611270

RESUMO

The present study sought to investigate the effect of non-mitogenic acidic fibroblast growth factor (NM-aFGF) loaded PEGylated nanoliposomes (NM-aFGF-PEG-lips) combined with the ultrasound-targeted microbubble destruction (UTMD) technique on modulating diabetic cardiomyopathy (DCM)and the mechanism involved. Animal studies showed that the diabetes mellitus (DM) group exhibited typical myocardial structural and functional changes of DCM. The indexes from the transthoracic echocardiography showed that the left ventricular function in the NM-aFGF-PEG-lips + UTMD group was significantly improved compared with the DM group. Histopathological observation further confirmed that the cardiomyocyte structural abnormalities and mitochondria ultrastructural changes were also significantly improved in the NM-aFGF-PEG-lips + UTMD group compared with DM group. The cardiac volume fraction (CVF) and apoptosis index in the NM-aFGF-PEG-lips + UTMD group decreased to 10.31 ± 0.76% and 2.16 ± 0.34, respectively, compared with those in the DM group (CVF = 21.4 ± 2.32, apoptosis index = 11.51 ± 1.24%). Moreover, we also found significantly increased superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) activity as well as clearly decreased lipid hydroperoxide levels and malondialdehyde (MDA) activity in the NM-aFGF-PEG-lips + UTMD group compared with those in the DM group (p < .05). Western blot analysis further revealed the highest level of NM-aFGF, p-AKT, p-GSK-3ß1, Nrf-2, SOD2 and NQO1 in the NM-aFGF-PEG-lips + UTMD group. This study confirmed using PEGylated nanoliposomes combined with the UTMD technique can effectively deliver NM-aFGF to the cardiac tissue of diabetic rats. The NM-aFGF can then inhibit myocardial oxidative stress damage due to DM by activating the AKT/GSK/Nrf-2 signaling pathway, which ultimately improved the myocardial structural and functional lesions in diabetic rats.


Assuntos
Cardiomiopatias Diabéticas/tratamento farmacológico , Fator 1 de Crescimento de Fibroblastos/administração & dosagem , Lipossomos/química , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Ultrassom/métodos , Animais , Química Farmacêutica/métodos , Glutationa Peroxidase/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Microbolhas , Polietilenoglicóis/química , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/efeitos dos fármacos
10.
Chem Commun (Camb) ; 53(92): 12438-12441, 2017 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-29099532

RESUMO

We report a photochemical reaction-induced antagonism between the photodynamic agent (PS) and anti-cancer drugs during combined therapy. The annihilation of singlet oxygen and alkene-containing drugs into inactive drug hydroperoxides is responsible for the antagonism, and results in decreased efficacy against several cancer cell lines. Experimental and simulation results reveal that the annihilation abates with increasing distance between the PS and drugs via confining the PS and drugs into separated vehicles. As a result, antagonism can be switched to synergism in treating both drug sensitive and resistant cancer cells.


Assuntos
Antineoplásicos/efeitos da radiação , Fármacos Fotossensibilizantes/efeitos da radiação , Porfirinas/efeitos da radiação , 1,2-Dipalmitoilfosfatidilcolina/química , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Incompatibilidade de Medicamentos , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Humanos , Luz , Lipossomos/química , Peróxidos/síntese química , Fármacos Fotossensibilizantes/administração & dosagem , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/administração & dosagem , Porfirinas/química , Porfirinas/farmacologia , Oxigênio Singlete/química
11.
Biomaterials ; 144: 60-72, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28823844

RESUMO

Preoperative chemotherapy is effective in improving the prognosis of patients, but its efficacy is impeded by cancer associated fibroblasts (CAFs) that enhance the survival, growth, and metastasis of cancer cells. To inhibit the activity of CAFs, prolonged and localized drug exposure is necessary. Here, we report on the rational design, screening, and evaluation of an injectable peptide hydrogel as a local losartan depot aiming to inhibit CAFs and potentiate chemotherapy. We synthesized a set of peptide derivatives and found that C16-GNNQQNYKD-OH (C16-N) surpassed the others in hydrogel formation and drug encapsulation, due to its flexible hydrocarbon tail and interpeptide hydrogen bonding that allowed supramolecular self-assembly into long filaments with hydrophobic cores. C16-N co-assembled with losartan to form hydrogel from which losartan was sustainably released over 9 days. After intratumoral injection, the hydrogel could be retained in the tumor for more than 9 days, significantly inhibited the CAFs and collagen synthesis in orthotopic 4T1 tumors, and enhanced the efficacy of PEGylated doxorubicin-loaded liposomes (Dox-L) in inhibiting the tumor growth (64% vs. Dox-L alone) and lung metastasis (80% vs. Dox-L alone). These results provide important guiding principles for the rational design of injectable peptide hydrogels aiming to regulate CAFs and improve chemotherapy.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Fibroblastos Associados a Câncer/efeitos dos fármacos , Preparações de Ação Retardada/química , Losartan/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Peptídeos/química , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Animais , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/uso terapêutico , Fibroblastos Associados a Câncer/patologia , Proliferação de Células/efeitos dos fármacos , Doxorrubicina/administração & dosagem , Doxorrubicina/análogos & derivados , Doxorrubicina/uso terapêutico , Sistemas de Liberação de Medicamentos/métodos , Feminino , Hidrogéis/química , Injeções , Losartan/uso terapêutico , Neoplasias Pulmonares/patologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/uso terapêutico , Neoplasias de Mama Triplo Negativas/patologia
12.
ACS Appl Mater Interfaces ; 7(45): 25147-61, 2015 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-26501354

RESUMO

Disulfiram, which exhibits marked tumor inhibition mediated by copper, was encapsulated in lipid nanocapsules modified with TAT peptide (TATp) and pH-triggered sheddable PEG to target cancer cells on the basis of tumor environmental specificity. PEG-shedding lipid nanocapsules (S-LNCs) were fabricated from LNCs by decorating short PEG chains with TATp (HS-PEG(1k)-TATp) to form TATp-LNCs and then covered by pH-sensitive graft copolymers of long PEG chains (PGA-g-PEG(2k)). The DSF-S-LNCs had sizes in the range of 60-90 nm and were stable in the presence of 50% plasma. DSF-S-LNCs exhibited higher intracellular uptake and antitumor activity at pH 6.5 than at pH 7.4. The preincubation of Cu showed that the DSF cytotoxicity was based on the accumulation of Cu in Hep G2 cells. Pharmacokinetic studies showed the markedly improved pharmacokinetic profiles of DSF-S-LNCs (AUC= 3921.391 µg/L·h, t(1/2z) = 1.294 h) compared with free DSF (AUC = 907.724 µg/L·h, t(1/2z) = 0.252 h). The in vivo distribution of S-LNCs was investigated using Cy5.5 as a fluorescent probe. In tumor-bearing mice, the delivery efficiency of S-LNCs was found to be 496.5% higher than that of free Cy5.5 and 74.5% higher than that of LNCs in tumors. In conclusion, DSF-S-LNCs increased both the stability and tumor internalization and further increased the cytotoxicity because of the higher copper content.


Assuntos
Cobre/química , Dissulfiram/uso terapêutico , Lipídeos/química , Nanocápsulas/química , Neoplasias/tratamento farmacológico , Polietilenoglicóis/química , Produtos do Gene tat do Vírus da Imunodeficiência Humana/química , Animais , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dissulfiram/farmacocinética , Dissulfiram/farmacologia , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Espectrometria de Massas , Camundongos Endogâmicos BALB C , Camundongos Nus , Tamanho da Partícula , Polietilenoglicóis/síntese química , Polissorbatos/química , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Luz Próxima ao Infravermelho , Eletricidade Estática , Distribuição Tecidual/efeitos dos fármacos
13.
J Vasc Access ; 16(4): 275-84, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25684581

RESUMO

PURPOSE: To investigate the role of wall shear stress in aspects of the formation of fibrin sheath and intimal thickening in a dog model. METHODS: Tunneled silicone 14.5-F catheters were inserted into the left internal jugular vein in eight dogs. The dogs were separated into two groups according to catheter indwelling time of 14 and 28 days. All dogs underwent extracorporeal circulation three times a week. Multidetector computed tomography venography (MDCTV) examination was used to examine the catheter tip thrombus. After the animals were sacrificed, histological and immunohistochemistry evaluations were performed to confirm specific cell populations. We used computer modeling to generate wall shear stress profiles for the blood flow through the catheter. RESULTS: Catheter-related sheaths were identified in all catheter specimens, but there was no fibrin sheath around the catheter tip. There were also differences in wall shear stress between the different venous wall sites. Differences in vein wall thickening at different sites have been found at both 14 days (intima to media (I/M) ratio S1 vs S2: p = 0.01, S3 vs S4: p<0.01) and 28 days (I/M ratio S1 vs S2: p<0.01, S3 vs S4: p<0.05). CONCLUSIONS: After catheter placement, fibrin sheath formation partially covered the catheter. Meanwhile, focal areas of intimal thickening were also seen in the venous wall adjacent to the sites of high wall shear stress. These findings indicate an important role of wall shear stress profiles in fibrin sheath formation and intimal thickening.


Assuntos
Obstrução do Cateter/etiologia , Cateterismo Venoso Central/efeitos adversos , Cateteres Venosos Centrais/efeitos adversos , Fibrina/metabolismo , Hemodinâmica , Veias Jugulares/fisiopatologia , Neointima , Animais , Cateterismo Venoso Central/instrumentação , Simulação por Computador , Cães , Desenho de Equipamento , Veias Jugulares/diagnóstico por imagem , Veias Jugulares/metabolismo , Modelos Animais , Modelos Cardiovasculares , Tomografia Computadorizada Multidetectores , Flebografia/métodos , Silicones , Estresse Mecânico , Fatores de Tempo
14.
PLoS One ; 9(1): e85570, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24409332

RESUMO

With the trend of an increasing aged population worldwide, Alzheimer's disease (AD), an age-related neurodegenerative disorder, as one of the major causes of dementia in elderly people is of growing concern. Despite the many hard efforts attempted during the past several decades in trying to elucidate the pathological mechanisms underlying AD and putting forward potential therapeutic strategies, there is still a lack of effective treatments for AD. The efficacy of many potential therapeutic drugs for AD is of main concern in clinical practice. For example, large bodies of evidence show that the anti-tumor histone deacetylase (HDAC) inhibitor, suberoylanilidehydroxamic acid (SAHA), may be of benefit for the treatment of AD; however, its extensive inhibition of HDACs makes it a poor therapeutic. Moreover, the natural flavonoid, curcumin, may also have a potential therapeutic benefit against AD; however, it is plagued by low bioavailability. Therefore, the integrative effects of SAHA and curcumin were investigated as a protection against amyloid-beta neurotoxicity in vitro. We hypothesized that at low doses their synergistic effect would improve therapeutic selectivity, based on experiments that showed that at low concentrations SAHA and curcumin could provide comprehensive protection against Aß25-35-induced neuronal damage in PC12 cells, strongly implying potent synergism. Furthermore, network analysis suggested that the possible mechanism underlying their synergistic action might be derived from restoration of the damaged functional link between Akt and the CBP/p300 pathway, which plays a crucial role in the pathological development of AD. Thus, our findings provided a feasible avenue for the application of a synergistic drug combination, SAHA and curcumin, in the treatment of AD.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Curcumina/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Fármacos Neuroprotetores/farmacologia , Nylons/farmacologia , Pirróis/farmacologia , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Apoptose/efeitos dos fármacos , Proteína de Ligação a CREB/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Progressão da Doença , Sinergismo Farmacológico , Proteína p300 Associada a E1A/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Redes Reguladoras de Genes , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Células PC12 , Ratos
15.
Int J Pharm ; 406(1-2): 84-90, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21219996

RESUMO

The purpose of the present study was to prepare matrix extended release pellets of diclofenac potassium using low amount of release-modifying agents and, to compare its performance in vivo with coated pellets and matrix tablets. Coated pellets were prepared by extrusion-spheronization, followed by double layer coating using different polymers separately. Matrix pellets with different release rate in vitro were prepared by extrusion-spheronization with different kinds of retarding materials. Bioavailability study of different coated pellets revealed that the drug concentration in plasma of beagle dogs was too low to be detected and, implied that the drug was nearly not released from the preparations before reaching colon due to the appearance of lag time in the dissolution process. The phenomenon indicated that slow-release pellets of diclofenac potassium perhaps should not be developed as double membrane-controlled type. The AUC((0 → 24)) of the immediate release pellets, the two matrix pellets and the reference were 304.4, 87.7, 204.1 and 179.1 µg h/ml, respectively. The C(max) of the formulations mentioned above were 46.3, 13.0, 33.6 and 32.1 µg/ml, respectively. All the matrix formulations, including the reference, exhibited incomplete absorption due to the short small intestine transit time and termination of the drug release in the colon because of its limited solubility. The matrix pellets were bioequivalent with the commercially available tablet (Voltaren(®)) although the drug release in vitro of the former was much faster, while the bioavailability of the matrix pellets with similar in vitro drug release to the reference (Voltaren(®)) was much lower than the latter. The results perhaps was caused by lacking of physical robustness in the waxy tablet formulation, resulted in low wet strength and easily destroyed by the mechanical destructive forces and finally introduced faster drug release rate in vivo. It is apparent that preparations with similar performance in vitro may differ a lot in vivo because of the differences in drug release rate in vivo owing to various wet strengths of excipients contained, especially for sustained release products.


Assuntos
Diclofenaco , Polímeros/química , Animais , Disponibilidade Biológica , Química Farmacêutica , Diclofenaco/administração & dosagem , Diclofenaco/sangue , Diclofenaco/química , Cães , Solubilidade , Comprimidos com Revestimento Entérico
16.
Int J Pharm ; 375(1-2): 16-21, 2009 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-19504748

RESUMO

The aim of this investigation was to prepare ergoloid mesylate submicron emulsions (EMSEs) for enhancing nasal absorption of drug and reducing nasal ciliotoxicity. Following intranasal administrations of EMSE and ergoloid mesylate solution (EMS) and intravenous administration of EMS to rats separately at the dose of 2 mg kg(-1), the levels of EM in blood and the cerebrospinal fluid (CSF) were evaluated by microdialysis method. The nasal ciliotoxicity was evaluated by using in situ toad palate model. The absolute bioavailability and the AUC in the CSF following intranasal administration of EMSE (56.3 +/- 5.3%, AUC(CSF) 28,594 +/- 5680 ng ml(-1) min) were statistically higher than those after intranasal administration of EMS (47.4 +/- 3.5%, AUC(CSF) 19,870 +/- 2247 ng ml(-1) min). No significant difference was found for the value of the brain drug direct transport percentage (DTP%) or the drug targeting efficiency (DTE) between the group receiving EMSE and the group receiving EMS. In conclusion, EMSE exhibited higher nasal absorption of EM in rats and significantly lower nasal ciliotoxicity whereas no greater brain-targeting efficiency in comparison with EMS.


Assuntos
Sistemas de Liberação de Medicamentos , Mesilatos Ergoloides/farmacocinética , Mucosa Nasal/efeitos dos fármacos , Administração Intranasal , Animais , Anuros , Área Sob a Curva , Disponibilidade Biológica , Transporte Biológico , Encéfalo/metabolismo , Cílios/efeitos dos fármacos , Cílios/metabolismo , Emulsões , Mesilatos Ergoloides/administração & dosagem , Masculino , Microdiálise , Mucosa Nasal/metabolismo , Palato/efeitos dos fármacos , Palato/metabolismo , Ratos , Ratos Sprague-Dawley , Testes de Toxicidade
17.
Drug Dev Ind Pharm ; 34(1): 83-9, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18214759

RESUMO

Hot-melt extruded tablets with enteric and sustained-release properties were prepared using ketoprofen as a model drug and Eudragit L100 as the carrier. Ketoprofen, with a similar solubility parameter to Eudragit L100, was homogeneously dispersed in the polymer matrix in a non-crystalline state, and was identified by differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy analysis. To compare the enteric and sustained-release characteristics, tablets of physical mixtures and comminuted extrudates were also produced with a tensile strength of 5.0 kg/cm2. The drug release percentage was below 3% in 0.1 M HCl and a sustained release for 6 to 12 hours was obtained with the tablets prepared by direct cutting of the extrudates and by compressing the pulverized extrudates, while no enteric and sustained-release properties were exhibited by the physical mixture tablets. The release mechanisms of the two types of tablets from their extrudates were different only because of their porosity. For the cut tablets, the drug was released according to the erosion mechanism, whereas in the extruded tablets the release property was controlled by erosion and diffusion mechanisms simultaneously.


Assuntos
Anti-Inflamatórios não Esteroides/química , Cetoprofeno/química , Ácidos Polimetacrílicos/química , Anti-Inflamatórios não Esteroides/administração & dosagem , Preparações de Ação Retardada , Cetoprofeno/administração & dosagem , Microscopia Eletrônica de Varredura , Ácidos Ftálicos/química , Plastificantes/química , Solubilidade , Comprimidos com Revestimento Entérico , Tecnologia Farmacêutica , Resistência à Tração , Difração de Raios X
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