Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
Biochim Biophys Acta Gen Subj ; 1861(7): 1676-1690, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28188858

RESUMO

BACKGROUND: Photodynamic therapy, using porphyrins as photosensitizers (PS), has been approved in treatment of several solid tumors. However, commonly used PS induce death but also resistance pathways in cancer cells and an alteration of surrounding normal tissues. Because polyamines (PA) are actively accumulated in cancer cells by the Polyamine Transport System (PTS), they may enable PS to specifically target cancer cells. Here, we investigated whether new protoporphyrin IX-polyamine derivatives were effective PS against prostate cancer and whether PA increased PDT specificity after 630nm irradiation. METHODS: CHO and CHO-MG cells (differing in their PTS activity) were used to assess efficacy of polyamine vectorization. MTT assays were performed on human prostate non-malignant (RWPE-1) and malignant (PC-3, DU 145 and LNCaP) cell lines to test PS phototoxicity. ROS generation, DNA fragmentation and cell signalling were assessed by ELISA/EIA, western-blots and gel shift assays. Finally, PS effects were studied on tumor growth in nude mice. RESULTS: Our PS were more effective on cancer cells compared to non-malignant cells and more effective than PpIX alone. PpIX-PA generated ROS production involved in induction of apoptotic intrinsic pathways. Different pathways involved in apoptosis resistance were studied: PS inhibited Bcl-2, Akt, and NF-κB but activated p38/COX-2/PGE2 pathways which were not implicated in apoptosis resistance in our model. In vivo experiments showed PpIX-PA efficacy was greater than results obtained with PpIX. CONCLUSIONS: All together, our results showed that PpIX-PA exerted its maximum effects without activating resistance pathways and appears to be a good candidate for prostate cancer PDT treatment.


Assuntos
Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Poliaminas/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Protoporfirinas/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Células CHO , Linhagem Celular Tumoral , Cricetulus , Humanos , Masculino , Poliaminas/farmacologia , Neoplasias da Próstata/patologia , Protoporfirinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Surg Endosc ; 30(7): 3152-9, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26487225

RESUMO

BACKGROUND AND AIMS: Good use of the submucosal space is key during endoscopic submucosal dissection (ESD). High-pressure injection of a long-lasting viscous solution using the HybridKnife water-jet system has been demonstrated to be feasible. We compared jet injection of glycerol and normal saline during pig gastric ESD and assessed its feasibility and efficiency during human ESD. MATERIALS AND METHODS: A blinded randomised controlled study of ESD with the HybridKnife injecting either a glycerol mixture or normal saline and a prospective human case series were performed. Twenty gastric pig dissections (10/group) and 38 human ESDs along the gastrointestinal tract were performed. Dissection speed, specimen size, procedure duration, rates of en bloc and R0 resection, and rates of bleeding and perforation were prospectively recorded. An evaluation of operator comfort and perceived safety (dissection score) was performed using a visual analogue scale with zero being the worst score and ten the best. RESULTS: Dissection was significantly more rapid (1.38-fold) with glycerol injection than with normal saline injection (28.94 vs. 20.91 mm(2)/min; p = 0.037). The dissection score was significantly higher in the glycerol group than in the normal saline group (7.3 vs. 4.7; p = 0.0064). No differences were observed in the rates of en bloc resection, bleeding, or perforation. The 38 human cases along the gastrointestinal tract revealed good results (en bloc resection rate = 100 %, R0 resection rate = 90 %) without any complications. CONCLUSION: High-pressure jet injection of glycerol with the HybridKnife for ESD increased the speed and operator comfort of the procedure compared with the use of normal saline, and the procedure was safe and efficient for human ESD. The advantages of using a combination of the HybridKnife system and a viscous glycerol solution will help to spread the use of the ESD technique, particularly in non-Asian countries.


Assuntos
Dissecação/métodos , Ressecção Endoscópica de Mucosa/métodos , Glicerol/administração & dosagem , Injeções a Jato/métodos , Estômago/cirurgia , Animais , Ressecção Endoscópica de Mucosa/instrumentação , Humanos , Estudos Prospectivos , Sus scrofa , Suínos
3.
Surg Endosc ; 29(11): 3382-5, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25631107

RESUMO

BACKGROUND AND AIMS: The HybridKnife water-jet system (ERBE, Tubingen, Germany) has been shown to increase dissection speed and decreased the risk of perforation during endoscopic submucosal dissection (ESD). Glycerol mixture is a viscous, long-lasting solution preferentially used by Japanese ESD experts. The combination of the HybridKnife system with a glycerol solution has not been evaluated to date. MATERIALS AND METHODS: A prospective non-randomised comparative study of ESD with HybridKnife injecting of either a glycerol mixture or normal saline was performed. Twenty dissections (ten per group) were performed on four anaesthetised domestic mini-pigs. Dissection speed (mm(2)/min), size of the specimen (mm(2)), duration (min), en bloc resection rate, and bleeding and perforation rates were prospectively recorded. An evaluation of operator comfort and perception of safety (dissection score) was performed using a visual analogue scale with 0 being the worst score and 10 the best. RESULTS: High-pressure injection of the glycerol mixture and dissection with the HybridKnife was feasible without complications. Dissection was significantly more rapid (1.67-fold) with glycerol injection than normal saline injection (27.44 vs. 16.44 mm(2)/min; p < 0.001). The dissection score was significantly higher in the glycerol group than in the normal saline group (5.9 vs. 2.9; p < 0.001). No differences were observed in the rates of en bloc resection, bleeding and perforation. Seven first human cases were also easy without need of preliminary incision and technical complication. CONCLUSION: High-pressure jet injection of glycerol with HybridKnife for ESD is feasible and increases the speed and safety of the procedure compared with use of normal saline.


Assuntos
Dissecação/instrumentação , Endoscopia Gastrointestinal/métodos , Glicerol/administração & dosagem , Solventes/administração & dosagem , Estômago/cirurgia , Animais , Dissecação/métodos , Endoscopia Gastrointestinal/instrumentação , Estudos de Viabilidade , Humanos , Injeções , Avaliação de Resultados em Cuidados de Saúde , Pressão , Estudos Prospectivos , Sus scrofa
4.
Front Microbiol ; 8: 1891, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29021787

RESUMO

Objectives: Dissemination of antimicrobial resistance (AMR) is a global issue that requires the adoption of a "One-Health" approach promoting integration of human and animal health. Besides culture-dependent techniques frequently used for AMR surveillance, cultivation-independent methods can give additional insights into the diversity and reservoir of AMR genetic determinants. Integrons are molecular markers that can provide overall and reliable estimation of AMR dissemination. In this study, considering the "One-Health" approach, we have analyzed the integron digestive carriage from stools of humans and cattle living in a same area and exposed to different antibiotic selection pressures. Methods: Three collections of human [general population (GP) and intensive care unit patients (ICUs)] and bovine (BOV) stool samples were analyzed. The three main classes of integrons were detected using a multiplex qPCR both from total DNA extracted from stools, and from Gram-negative bacteria obtained by culture after an enrichment step. Results: With the cultivation-independent approach, integron carriage was 43.8, 52.7, and 65.6% for GP, ICU, and BOV respectively, percentages being at least twofold higher to those obtained with the cultivation-dependent approach. Class 1 integrons were the most prevalent; class 2 integrons seemed more associated to cattle than to humans; no class 3 integron was detected. The integron carriage was not significantly different between GP and ICU populations according to the antibiotic consumption, whatever the approach. Conclusion: The cultivation-independent approach constitutes a complementary exploratory method to investigate the integron digestive carriage of humans and bovines, notably within subjects under antibiotic treatment. The high frequency of carriage of integrons in the gut is of clinical significance, integrons being able to easily acquire and exchange resistant genes under antibiotic selective pressure and so leading to the dissemination of resistant bacteria.

5.
J Neurosurg ; 126(5): 1702-1713, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27203141

RESUMO

OBJECTIVE The outcome for jailing arterial branches that emerge near intracranial aneurysms during flow-diverting stent (FDS) deployment remains controversial. In this animal study, the authors aimed to elucidate the role of collateral supply with regard to the hemodynamic changes and neointimal modifications that occur from jailing arteries with FDSs. To serve this purpose, the authors sought to quantify 1) the hemodynamic changes that occur at the jailed arterial branches immediately after stent placement and 2) the ostia surface values at 3 months after stenting; both parameters were investigated in the presence or absence of collateral arterial flow. METHODS After an a priori power analysis, 2 groups (Group A and Group B) were created according to an animal flow model for terminal and anastomotic arterial circulation; each group contained 7 Large White swine. Group A animals possessed an anastomotic-type arterial configuration to supply the territory of the right ascending pharyngeal artery (APhA), while Group B animals possessed a terminal-type arterial configuration to supply the right APhA territory. Subsequently, all animals underwent FDS placement, thereby jailing the right APhAs. Mean flow rates and velocities inside the jailed branches were quantified using time-resolved 3D phase-contrast MR angiography before and after stenting. Three months after stent placement, the jailed ostia surface values were quantified on scanning electron micrographs. The data were analyzed using descriptive statistics and group comparisons with parametric and nonparametric tests. RESULTS The endovascular procedures were feasible, and there were no findings of in situ thrombus formation on postprocedural optical coherence tomography or ischemia on postprocedural diffusion-weighted imaging. In Group A, the mean flow rate values at the jailed right APhAs were reduced immediately following stent placement as compared with values obtained before stent placement (p = 0.02, power: 0.8). In contrast, the mean poststenting flow rates for Group B remained similar to those obtained before stent placement. Three months after stent placement, the mean ostia surface values were significantly higher for Group B (527,911 ± 306,229 µm2) than for Group A (89,329 ± 59,762 µm2; p < 0.01, power: 1.00), even though the initial dimensions of the jailed ostia were similar between groups. A statistically significant correlation was found between groups (A or B), mean flow rates after stent placement, and ostia surface values at 3 months. CONCLUSIONS When an important collateral supply was present, the jailing of side arteries with flow diverters resulted in an immediate and significant reduction in the flow rate inside these arteries as compared with the prestenting values. In contrast, when competitive flow was absent, jailing did not result in significant flow rate reductions inside the jailed arteries. Ostium surface values at 3 months after stent placement were significantly higher in the terminal group of jailed arteries (Group B) than in the anastomotic group (Group A) and strongly correlated with poststenting reductions in the velocity value.


Assuntos
Artéria Carótida Primitiva/fisiopatologia , Procedimentos Endovasculares , Aneurisma Intracraniano/fisiopatologia , Fluxo Sanguíneo Regional/fisiologia , Stents , Grau de Desobstrução Vascular/fisiologia , Anastomose Cirúrgica , Animais , Velocidade do Fluxo Sanguíneo , Artéria Carótida Primitiva/cirurgia , Circulação Colateral/fisiologia , Modelos Animais de Doenças , Aneurisma Intracraniano/etiologia , Aneurisma Intracraniano/cirurgia , Suínos
6.
J Neurosurg ; 125(4): 898-908, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26771853

RESUMO

OBJECTIVE The authors describe herein the creation of an animal model capable of producing quantifiable data regarding blood flow rate and velocity modifications in terminal and anastomotic types of cerebrofacial circulation. They also present the preliminary results of a translational study aimed at investigating the role of terminal and anastomotic types of circulation in arterial branches jailed by flow-diverting stents as factors contributing to arterial patency or occlusion. METHODS Two Large White swine were used to validate a terminal-type arterial model at the level of the right ascending pharyngeal artery (APhA), created exclusively by endovascular means. Subsequently 4 Large White swine, allocated to 2 groups corresponding to the presence (Group B) or absence (Group A) of terminal-type flow modification, underwent placement of flow-diverting stents. Blood flow rates and velocities were quantified using a dedicated time-resolved 3D phase-contrast MRA sequence before and after stenting. Three months after stent placement, the stented arteries were evaluated with digital subtraction angiography (DSA) and scanning electron microscopy (SEM). Patent (circulating) ostia quantification was performed on the SEM images. RESULTS Terminal-type flow modification was feasible; an increase of 75.8% in mean blood velocities was observed in the right APhAs. The mean blood flow rate for Group A was 0.31 ± 0.19 ml/sec (95% CI -1.39 to 2.01) before stenting and 0.21 ± 0.07 ml/sec (95% CI -0.45 to 0.87) after stenting. The mean blood flow rate for Group B was 0.87 ± 0.32 ml/sec (95% CI -1.98 to 3.73) before stenting and 0.76 ± 0.13 ml/sec (95% CI -0.41 to 1.93) after stenting. Mean flow rates after stenting showed a statistically significant difference between Groups A and B (Welch test). Mean and maximal blood velocities were reduced in Group A cases and did not decrease in Group B cases. Control DSA and SEM findings showed near occlusion of the jailed APhAs in both cases of anastomotic circulation (mean patent ostium surface 32,776 µm2) and patency in both cases of terminal-type circulation (mean patent ostium surface 422,334 µm2). CONCLUSIONS Terminal-type arterial modification in swine APhAs is feasible. Sufficient data were acquired to perform an a priori analysis for further research. Flow diversion at the level of the APhA ostium resulted in significant stenosis in cases of anastomotic circulation, while sufficient patency was observed in terminal-type circulation.


Assuntos
Artérias/fisiopatologia , Circulação Colateral/fisiologia , Stents , Doenças Vasculares/fisiopatologia , Grau de Desobstrução Vascular , Animais , Velocidade do Fluxo Sanguíneo , Modelos Animais de Doenças , Feminino , Masculino , Modelos Animais , Suínos
7.
Endosc Int Open ; 4(7): E796-9, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27556100

RESUMO

INTRODUCTION: Gastroparesis, or delayed gastric emptying, can be diagnosed with gastric emptying scintigraphy. Manometric studies of patients with gastroparesis show increased pyloric tone (pylorospasm). Among the recent endoscopic therapies for pylorospasm is peroral endoscopic pylorotomy (POP). In this study, we explored the effect of POP on gastric emptying in healthy pigs. MATERIAL AND METHODS: Four mini-pigs underwent POP following general anaesthesia. The mucosal entrance was situated 5 cm above the pylorus. POP was performed through a submucosal tunnel dissection. The duration of gastric emptying was assessed by scintigraphy before and after the procedure. The pigs were then euthanised for necropsy and pathologic assessment of the pylorus. RESULTS: The mean duration of the procedure was 55 (±â€Š4 SD) min. All surgeries were performed in their entirety with 100 % feasibility. There were no cases of bleeding. The one case of perforation had no clinical significance. The duration of gastric emptying was 2.22-fold shorter after POP compared with before POP (T½ post-POP = 84.5 [±â€Š35.7 SD] min vs. T½ pre-POP = 188.4 [±â€Š87.3 SD] min; P = 0.029). In agreement with the endoscopic observations, sectioning of the pyloric muscle in each pig was histologically complete. CONCLUSION: The efficacy of the procedure provides indirect proof of the involvement of the pyloric ring in delayed gastric emptying and suggests new therapies for patients with gastroparesis. Our protocol combining gastric emptying scintigraphy and POP validated the use of anaesthetised mini-pigs as a learning and training model for POP or other endoscopic/surgical procedures related to gastric emptying.

8.
Dig Liver Dis ; 48(12): 1457-1462, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27590842

RESUMO

BACKGROUND AND AIMS: The high specific skill needed by ESD limit its widespread use in Europe and animal training is recommended in Europe to improve the results of ESD that are far from Japanese at present. We create a local training program using live pigs as models, along with our human cases, to provide continuous exposure to the technique. METHODS: Between February 2013 and December 2015, two young operators performed 55 pig gastric ESDs in parallel with 62 human cases for large superficial cancerous lesions. The number and training dates of pig cases were adapted to those of the human cases to achieve continuous exposure to ESD cases. RESULTS: The en bloc, R0, and curative resection rates were 100%, 85.5% (53/62), and 77.5% (48/62), respectively with no recurrence observed during the one year follow up. There was no statistically significant difference in terms of the R0 or curative resection rates among ESDs performed during 2013-2015 (R0: 80% vs. 86.6% vs. 86.4%; Curative: 80% vs. 86.6% vs. 73%). CONCLUSION: A local structured training program using live pig models was used to train endoscopists for ESD in humans with high safety and efficiency, similar to results published by Japanese experts.


Assuntos
Dissecação/métodos , Educação , Endoscopia/educação , Mucosa Intestinal/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Competência Clínica , França , Humanos , Mucosa Intestinal/patologia , Curva de Aprendizado , Pessoa de Meia-Idade , Modelos Animais , Sus scrofa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA