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2.
Can Urol Assoc J ; 16(10): 334-339, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35621285

RESUMO

INTRODUCTION: During the first regional COVID-19 lockdown in March 2020, we conducted a study aimed at evaluating completeness of telemedicine consultation in urology. Of 1679 consultations, 67% were considered completely managed by phone. The aim of the present study was to assess patients' experience and satisfaction with telemedicine and to compare them with urologists' perceptions about quality and completeness of the telemedicine consultation. METHODS: We contacted a randomly selected sample of patients (n=356) from our previous study to enquire about their experience. We used a home patient experience questionnaire, inspired by the Patient Experiences Questionnaire for Out-of-Hours Care (PEQOHC) and the Consumer Assessment Health Profile Survey (CAHPS). RESULTS: Of 356 patients contacted, 315 agreed to complete the questionnaire. Urological consultations were for non-oncological (104), oncological (121), cancer suspicion (41), and pediatric (49) indications. Mean patient satisfaction score after telemedicine consultation was 8.8/10 (median 9/10) and 86.3% of patients rated the quality of the consultation as either excellent (54.6%) or very good (31.7%). Consultations regarding cancer suspicion had the lowest score (8.3/10). Overall, 46.7% of all patients would have preferred an in-person visit outside of the pandemic situation. Among patients whose consultations were rated suboptimal by urologists, almost a third more (31.2%) would have preferred an in-person visit (p=0.03). CONCLUSIONS: Despite high reported patient satisfaction rates with telemedicine, it is noteworthy that nearly half of the patients would have preferred an in-person visit. Post-pandemic, it will be important to incorporate telemedicine as an alternative, while retaining and offering in-person visits.

3.
Can Urol Assoc J ; 14(10): 319-321, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33275552

RESUMO

INTRODUCTION: The COVID-19 pandemic has accelerated the development of telemedicine due to confinement measures. However, the percentage of outpatient urological cases that could be managed completely by telemedicine outside of the COVID-19 pandemic remains to be determined. We conducted a prospective, multisite study involving all urologists working in the region of Quebec City. METHODS: During the first four weeks of the regional confinement, 18 pediatric and adult urologists were asked to determine, after each telemedicine appointment, if it translated into a complete (CCM), incomplete (ICM), or suboptimal case management (SCM, adequate only in the context of the pandemic). RESULTS: A total of 1679 appointments representing all urological areas were registered. Overall, 67.6% (95% confidence interval [CI] 65.3; 69.8), 27.1% (25.0; 29.3), and 4.3% (3.5; 5.4) were reported as CCM, SCM, and ICM, respectively. The CCM ratio varied according to the reason for consultation, with cancer suspicion (52.9% [42.9; 62.8]) and pediatric reasons (38.0% [30.0; 46.6]) showing the lowest CCM percentages. CCM percentages also varied significantly based on the setting where it was performed, ranging from 61.1% (private clinic) to 86.8% (endourology and general hospital). CONCLUSIONS: We show that two-thirds of all urological outpatient cases could be completely managed by telemedicine outside of the pandemic. After the pandemic, it will be important to incorporate telemedicine as an alternative for a patient's first or followup visit, especially those with geographical, pathological, and socioeconomic considerations.

4.
Methods Mol Biol ; 1943: 377-387, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30838630

RESUMO

Ultrasound-mediated gene delivery is an interesting approach, which could help in increasing gene transfer in deep tissues. Moreover, it allows for performing experiments guided by the image to determine which elements are required. Microbubbles complexed with a eukaryotic expression cassette are excellent agents as they are responsive to ultrasounds and, upon oscillation, can destabilize membranes to enhance gene transfer. Here, we describe the preparation of positively charged microbubbles, plasmid free of antibiotic resistance marker, their combination and the conditions of ultrasound-mediated liver transfection post-systemic administration in mice. This association allowed us to obtain a superior liver gene expression at least over 8 months after a single injection.


Assuntos
Microbolhas , Transfecção/métodos , Ondas Ultrassônicas , Animais , Permeabilidade da Membrana Celular/efeitos da radiação , Terapia Genética/métodos , Células HeLa , Humanos , Fígado/citologia , Fígado/metabolismo , Fígado/efeitos da radiação , Camundongos , Camundongos Endogâmicos BALB C , Ácidos Nucleicos/genética
5.
J Control Release ; 262: 170-181, 2017 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-28710005

RESUMO

Despite the increasing number of clinical trials in gene therapy, no ideal methods still allow non-viral gene transfer in deep tissues such as the liver. We were interested in ultrasound (US)-mediated gene delivery to provide long term liver expression. For this purpose, new positively charged microbubbles were designed and complexed with pFAR4, a highly efficient small length miniplasmid DNA devoid of antibiotic resistance sequence. Sonoporation parameters, such as insonation time, acoustic pressure and duration of plasmid injection were controlled under ultrasound imaging guidance. The optimization of these various parameters was performed by bioluminescence optical imaging of luciferase reporter gene expression in the liver. Mice were injected with 50µg pFAR4-LUC either alone, or complexed with positively charged microbubbles, or co-injected with neutral MicroMarker™ microbubbles, followed by low ultrasound energy application to the liver. Injection of the pFAR4 encoding luciferase alone led to a transient transgene expression that lasted only for two days. The significant luciferase signal obtained with neutral microbubbles decreased over 2days and reached a plateau with a level around 1 log above the signal obtained with pFAR4 alone. With the newly designed positively charged microbubbles, we obtained a much stronger bioluminescence signal which increased over 2days. The 12-fold difference (p<0.05) between MicroMarker™ and our positively charged microbubbles was maintained over a period of 6months. Noteworthy, the positively charged microbubbles led to an improvement of 180-fold (p<0.001) as regard to free pDNA using unfocused ultrasound performed at clinically tolerated ultrasound amplitude. Transient liver damage was observed when using the cationic microbubble-pFAR4 complexes and the optimized sonoporation parameters. Immunohistochemistry analyses were performed to determine the nature of cells transfected. The pFAR4 miniplasmid complexed with cationic microbubbles allowed to transfect mostly hepatocytes compared to its co-injection with MicroMarker™ which transfected more preferentially endothelial cells.


Assuntos
DNA/administração & dosagem , Fígado/metabolismo , Microbolhas , Ondas Ultrassônicas , Animais , Técnicas de Transferência de Genes , Células HeLa , Humanos , Lipídeos/química , Fígado/diagnóstico por imagem , Luciferases/genética , Luciferases/metabolismo , Camundongos Endogâmicos BALB C , Plasmídeos , Transgenes , Ultrassonografia
6.
Can Urol Assoc J ; 11(6Suppl2): S125-S130, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28616110

RESUMO

Pelvic organ prolapse (POP) results from weakness or injury of the pelvic floor supports with resulting descent of one or more vaginal compartments (anterior, apical and/or posterior). Women typically become symptomatic from the bulging vaginal wall or related organ dysfunction once this descent reaches the introitus. POP is a common condition, affecting more than half of adult women. Many women presenting to an urologist for stress urinary incontinence or overactive bladder will have associated POP; therefore, it is important for urologists who treat these conditions to be familiar with its diagnosis and management. While POP is part of the core urology training curriculum in some jurisdictions, it is not in Canada.1 This article reviews the diagnosis of POP, including pertinent symptoms to query in the history, important facets of a systematic pelvic examination, and the appropriate use of ancillary tests. Treatment options are also discussed, including conservative measures, pessaries, and various reconstructive and obliterative techniques.

7.
Clin Nutr ; 35(6): 1291-1300, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27161521

RESUMO

Immune-enhancing diet (IED) utilization in critically ill septic patients is still debated. A new concept of IED has been proposed combining extra glutamine sequentially with either antioxidants or other amino acids, in order to match patient requirements according to their response to injury. We evaluated whether this new IED elicits a more favorable response to stress when compared with two existing IEDs both enriched in arginine but with different levels of anti-oxidants, in a validated rat model combining head injury (HI) and infectious complications. Forty-eight HI rats were randomized into four groups (n = 11-13 per group) to receive, for 4 days, standard enteral nutrition (S), one of the two existing IEDs (IED1, IED2), or the new IED (IED3; providing glutamine and antioxidants for two days and glutamine and specific amino acids for two days). Two days after HI, the rats received an enteral bolus of luminescent Escherichia coli Xen14 to induce infection, and bacterial dissemination was evaluated. Body weight (BW) was recorded daily. Four days after HI, animals were euthanized; blood was sampled; organs were weighed; cumulated nitrogen balance (CNB) and nitrogen efficiency were determined. IED3 was more efficient than IED1 and IED2 in improving BW recovery from D3 (D3 vs. D1, p < 0.05) after HI. It significantly improved CNB and net protein utilization (IED3 vs. S, IED1, IED2, p < 0.05). An IED with sequential administration of anti-oxidants and glutamine may be better suited to meeting nutritional requirements in severe catabolic states.


Assuntos
Traumatismos Craniocerebrais/complicações , Dietoterapia/métodos , Imunidade/fisiologia , Infecções/complicações , Estudo de Prova de Conceito , Aminoácidos/administração & dosagem , Animais , Antioxidantes/administração & dosagem , Traumatismos Craniocerebrais/imunologia , Traumatismos Craniocerebrais/fisiopatologia , Modelos Animais de Doenças , Nutrição Enteral , Infecções por Escherichia coli/complicações , Infecções por Escherichia coli/prevenção & controle , Glutamina/administração & dosagem , Humanos , Controle de Infecções/métodos , Necessidades Nutricionais , Ratos
8.
Ultrasound Med Biol ; 42(2): 624-30, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26653937

RESUMO

Microbubbles are polydisperse microparticles. Their size distribution cannot be accurately measured from the current methods used, such as optical microscopy, electrical sensing or light scattering. Indeed, these techniques present some limitations when applied to microbubbles, which prompted us to investigate the use of an alternative technique: tunable resistive pulse sensing (TRPS). This technique is based on the principle of the Coulter counter with the advantage of being more flexible compared to other methods using this principle, since the flow rate, the potential difference and the pore size can be modulated. The main limitation of TRPS is that more than one size of nanopore membrane is required to obtain the full size distribution of polydisperse microparticles. To evaluate this technique, the concentration and the size distribution of positively charged microbubbles were studied using TRPS and compared to data obtained using optical microscopy. We describe herein the parameters required for the accurate measurement of microbubble concentration and size distribution by TRPS and present a statistical comparison of the data obtained by TRPS and optical microscopy.


Assuntos
Eletroquímica/métodos , Lipídeos/análise , Membranas Artificiais , Microbolhas , Nanoporos/ultraestrutura , Ultrafiltração/métodos , Campos Eletromagnéticos , Eletricidade Estática
9.
Can Urol Assoc J ; 9(9-10): E613-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26425223

RESUMO

INTRODUCTION: Ketamine is a common recreational drug. Severe lower urinary tract symptoms associated with its consumption have been reported, but little is known about the involved mechanisms. The effect of ketamine, which is excreted in urine, was evaluated by its application on an in vitro three-dimensional human tissue-engineered bladder model composed of an urothelium and a submucosa. METHODS: Human urothelial cells were cultured with medium containing various concentrations of ketamine and harvested at different times to obtain growth curves. Using this model, specific activity of caspase-3 was measured to assess the level of apoptosis induced by ketamine. Finally, a human tissue-engineered bladder model was used. Urothelial cells were plated on a stromal layer made of dermal fibroblasts and incubated at the air/liquid interface to allow their differentiation. Ketamine was then put on the mature urothelium using paper or agarose vectors for 48 hours. RESULTS: The presence of ketamine increased cells' doubling times from 1.26 days for control to 1.38 days (p = 0.14) and 1.78 days (p < 0.01) for the 0.5 mM and 1.5 mM concentrations, respectively. 5 mM and 10 mM of ketamine led to decline in the major cell population. Exposure to 5 mM ketamine induced apoptosis, confirmed by a 2.5-fold increase in capase-3 specific activity from control (p = 0.03). The structure and cellular cohesion of the urothelium on the three-dimensional model, especially in the intermediate layers, were severely affected in a concentration dependant fashion with both vectors. CONCLUSION: The presence of ketamine in the bladder directly damages the urothelium through the induction of apoptosis.

10.
Acta Neurol Belg ; 114(3): 167-78, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24915752

RESUMO

Natalizumab (Tysabri(®)) is highly efficacious in controlling disease activity in relapsing multiple sclerosis (MS) patients. As it is one of the more recent therapies for MS, there remains a need for long-term safety and efficacy data of natalizumab in a clinical practice setting. The Tysabri observational program (TOP) is an open-label, multicenter, multinational, prospective observational study, aiming to recruit up to 6,000 patients with relapsing-remitting MS from Europe, Canada and Australia. The objectives of this study are to collect long-term safety and efficacy data on disease activity and disability progression. We report here the interim results of the 563 patients included in TOP between December 2007 and 2012 from Belgium. This patient cohort was older at baseline, had longer disease duration, higher neurological impairment, and a higher baseline annualized relapse rate, when compared to patients included in the pivotal phase III AFFIRM trial. Nevertheless, the efficacy of natalizumab was comparable. The annualized relapse rate on treatment was reduced by 90.70 % (p < 0.0001) with a cumulative probability of relapse of 26.87 % at 24 months. The cumulative probabilities of sustained disability improvement and progression at 24 months were 25.68 and 9.01 %, respectively. There were no new safety concerns over the follow-up period. Two cases of progressive multifocal leukoencephalopathy were diagnosed. Our results are consistent with other observational studies in the post-marketing setting.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Fatores Imunológicos/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Adolescente , Adulto , Distribuição por Idade , Idoso , Bélgica/epidemiologia , Estudos de Coortes , Avaliação da Deficiência , Feminino , Humanos , Cooperação Internacional , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Natalizumab , Vigilância de Produtos Comercializados , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
11.
ACS Nano ; 7(6): 4954-66, 2013 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-23641799

RESUMO

Cell-released vesicles are natural carriers that circulate in body fluids and transport biological agents to distal cells. As nature uses vesicles in cell communication to promote tumor progression, we propose to harness their unique properties and exploit these biogenic carriers as Trojan horses to deliver therapeutic payloads to cancer cells. In a theranostic approach, cell-released vesicles were engineered by a top-down procedure from precursor cells, previously loaded with a photosensitizer and magnetic nanoparticles. The double exogenous cargo provided vesicles with magnetic and optical responsiveness allowing therapeutic and imaging functions. This new class of cell-derived smart nanovectors was named "theranosomes". Theranosomes enabled efficient photodynamic tumor therapy in a murine cancer model in vivo. Moreover the distribution of this biogenic vector could be monitored by dual-mode imaging, combining fluorescence and MRI. This study reports the first success in translating a cell communication mediator into a smart theranostic nanovector.


Assuntos
Portadores de Fármacos/química , Portadores de Fármacos/metabolismo , Imãs , Nanoestruturas , Neoplasias da Próstata/patologia , Neoplasias do Colo do Útero/patologia , Animais , Membrana Celular/metabolismo , Feminino , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imageamento por Ressonância Magnética , Masculino , Mesoporfirinas/química , Mesoporfirinas/uso terapêutico , Camundongos , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/uso terapêutico , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/terapia , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/terapia
12.
Sci Transl Med ; 5(172): 172ra20, 2013 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-23408053

RESUMO

Although many human cancers are located in mucosal sites, most cancer vaccines are tested against subcutaneous tumors in preclinical models. We therefore wondered whether mucosa-specific homing instructions to the immune system might influence mucosal tumor outgrowth. We showed that the growth of orthotopic head and neck or lung cancers was inhibited when a cancer vaccine was delivered by the intranasal mucosal route but not the intramuscular route. This antitumor effect was dependent on CD8⁺ T cells. Indeed, only intranasal vaccination elicited mucosal-specific CD8⁺ T cells expressing the mucosal integrin CD49a. Blockade of CD49a decreased intratumoral CD8⁺ T cell infiltration and the efficacy of cancer vaccine on mucosal tumor. We then showed that after intranasal vaccination, dendritic cells from lung parenchyma, but not those from spleen, induced the expression of CD49a on cocultured specific CD8⁺ T cells. Tumor-infiltrating lymphocytes from human mucosal lung cancer also expressed CD49a, which supports the relevance and possible extrapolation of these results in humans. We thus identified a link between the route of vaccination and the induction of a mucosal homing program on induced CD8⁺ T cells that controlled their trafficking. Immunization route directly affected the efficacy of the cancer vaccine to control mucosal tumors.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/administração & dosagem , Quimiotaxia de Leucócito , Neoplasias de Cabeça e Pescoço/terapia , Imunidade nas Mucosas , Neoplasias Pulmonares/terapia , Mucosa Nasal/imunologia , Vacinas contra Papillomavirus/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Administração Intranasal , Animais , Antígenos CD/metabolismo , Vacinas Anticâncer/imunologia , Proliferação de Células , Células Cultivadas , Células Dendríticas/imunologia , Feminino , Neoplasias de Cabeça e Pescoço/imunologia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Injeções Intramusculares , Cadeias alfa de Integrinas/metabolismo , Integrina alfa1/metabolismo , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Linfonodos/imunologia , Linfócitos do Interstício Tumoral/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Vacinas contra Papillomavirus/imunologia , Toxinas Shiga/administração & dosagem , Baço/imunologia , Carga Tumoral
13.
J Gene Med ; 14(3): 204-15, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22328073

RESUMO

BACKGROUND: Electrotransfer can be obtained by the successive delivery of a high voltage short duration pulse (HV) inducing membrane destabilization and then a low voltage long duration pulse (LV), allowing DNA electrophoresis (HVLV mode). Pluronic® L64 (L64) (Fluka, Sigma-Aldrich, L'Isle-d'Abeau Chesnes, Saint-Quentin Fallavier, France) has permeabilizing properties and amplifies the expression of DNA. We aimed to determine whether L64 could have an adjuvant effect on transfection by electrotransfer and whether the sequence L64 injection and then application of a LV pulse could induce transfection comparable to that observed with the HVLV mode. METHODS: In vitro, we used fluorescence-activated cell sorting to evaluate Chinese hamster ovary (CHO) cell transfection by a plasmid coding green fluorescent protein, and permeabilization to propidium iodide. In vivo, the transfection efficiency of mice tibial cranial muscle was evaluated by optical imaging using a plasmid DNA encoding luciferase. For the same animals, permeabilization indices were evaluated by magnetic resonance imaging from the uptake of a T(1) contrast agent. RESULTS: Using the HVLV mode, transfection efficiency was low in vitro on CHO cells but high for muscles in vivo. Pre-treatment by L64 increased the transfection efficiency of electrotransfer for CHO cells but not for muscle. In mice muscles, the L64 amplified the expression of DNA. Nevertheless, neither transgene expression, nor permeability indices were further amplified by subsequent delivery of one LV pulse. CONCLUSIONS: A major finding of the present study is that the nature of the membrane modification induced by electric pulses is not comparable to that mediated by L64. The electrophoretic LV pulse does not induce additive effects to that of L64 for transfection improvement.


Assuntos
Eletroporação/métodos , Músculo Esquelético/metabolismo , Permeabilidade , Poloxâmero/metabolismo , Transfecção/métodos , Animais , Células CHO , Cricetinae , Cricetulus , Eletroforese/métodos , Citometria de Fluxo , Proteínas de Fluorescência Verde/metabolismo , Técnicas In Vitro , Luciferases , Imageamento por Ressonância Magnética , Camundongos , Camundongos Endogâmicos BALB C , Plasmídeos/genética , Poloxâmero/química , Estatísticas não Paramétricas
14.
Crit Care Med ; 40(1): 278-80, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22179343

RESUMO

OBJECTIVES: The benefit of arginine in intensive care unit patients with severe sepsis is still controversial. An excessive supply of arginine could lead to an overproduction of nitric oxide and could be responsible for septic shock and multiorgan failure. However, this claim is not supported by any experimental or clinical data. We set out to determine whether an enteral supply of arginine would modulate bacterial invasion in rats with head injury. METHODS: Male Sprague-Dawley rats with head injury were randomized into two groups. Group 1 included rats with head injury fed a standard enteral nutrition (Sondalis HP, n = 10) and group 2 included rats with head injury fed the standard enteral nutrition plus arginine (4 g/kg/d, n = 11). Two days after head injury, the rats received a single enteral bolus of luminescent Escherichia coli Xen 14. Bacterial proliferation was evaluated in vivo at time + 2 hrs and time + 6 hrs after E. coli challenge. Four days after head injury, blood was sampled for arginine and fibrinogen assay. Muscles, intestine, spleen, and thymus were removed and weighed. RESULTS: There was no mortality in either group. The luminescence signal was similar in the two groups at time +2 hrs (group 1: 414 [5-823] vs. group 2: 496 [0.1-993] (median value[min-max]; not significant) and was significantly lower at time +6 hrs in group 2 (group 1: 71 [0-142] vs. group 2: 8.5 [0-17]; p = .026). Arginine treatment did not improve any nutritional parameters. CONCLUSIONS: Arginine was not responsible for mortality in rats with head injury with infectious complications and reduced the intensity of bacterial invasion.


Assuntos
Arginina/uso terapêutico , Infecções Bacterianas/prevenção & controle , Traumatismos Craniocerebrais/tratamento farmacológico , Animais , Traumatismos Craniocerebrais/complicações , Traumatismos Craniocerebrais/microbiologia , Nutrição Enteral/métodos , Medições Luminescentes , Masculino , Ratos , Ratos Sprague-Dawley , Sepse/prevenção & controle
15.
J Neurotrauma ; 29(2): 335-42, 2012 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-21806472

RESUMO

Infectious complications are responsible for 10-25% of mortality in head-injured patients. In the present work we developed a model of infectious complications in head-injury rats using Escherichia coli (E. coli) with a stable copy of the lux operon, and monitored the infection in vivo by optical imaging. Rats were randomized into three groups: AL (healthy rats), HI (head-injury rats), and HI-EC (HI rats+single enteral bolus of E. coli, 1.3×10(9)/rat given 2 days after HI). Infection was evaluated with a camera at 2 and 6 h after E. coli challenge. Blood and organs were sampled to assess biological parameters. HI was associated with body weight loss, muscle atrophy, and plasma amino acid disturbances, in particular glutamine depletion (AL 919±37 versus HI 647±25 and HI-EC 717±20 µmol/L; p<0.05). In the HI-EC rats, the luminescence signal was observed at T+2 (mean [range]: 34,778 cpm [1617-2,918,810]), and was significantly decreased at T+6 (0 cpm [0-847,922]; p<0.05). Bacterial challenge was associated with a specific body weight loss and a decrease in gastrocnemius protein content, in alanine (AL 512±41 versus HI-EC 395±29 µmol/L; p<0.05), and in sulfur plasma amino acids. In conclusion, we propose a controlled model of HI with infectious complications characterized by specific metabolic alterations. Combined with the in vivo monitoring of the infection by bioluminescence, this model offers a valuable tool to evaluate specific strategies for HI patients.


Assuntos
Lesões Encefálicas/complicações , Lesões Encefálicas/microbiologia , Traumatismos Craniocerebrais/complicações , Traumatismos Craniocerebrais/microbiologia , Modelos Animais de Doenças , Medições Luminescentes/métodos , Sepse/etiologia , Animais , Progressão da Doença , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/patogenicidade , Infecções por Escherichia coli/etiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/fisiopatologia , Medições Luminescentes/tendências , Masculino , Ratos , Ratos Sprague-Dawley , Sepse/diagnóstico , Sepse/microbiologia , Sepse/fisiopatologia
16.
J Control Release ; 151(1): 57-64, 2011 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-21241749

RESUMO

Poloxamers are triblock copolymers made of poly(ethylene glycol)-(poly(propylene glycol))-poly(ethylene glycol). They have been shown to enhance gene transfer in the muscle, and co-administration of polymers and DNA appeared to be crucial to obtain this effect. It is questionable then if some interaction occurs between polymers and DNA. Polymer interaction with membranes represents a second crucial point due to the central hydrophobic part of the triblock copolymers. Besides, the question of the polymer spanning or adsorbing to the surface has not been solved by now. We addressed these issues by means of sensitive techniques that allowed working in diluted conditions and gaining in comprehension of gene transfection. By means of simultaneous time-correlated single-photon counting and fluorescence correlation spectroscopy, we have shown that the diffusion time of a single DNA molecule and PicoGreen lifetime was not altered in the presence of the triblock copolymer L64. Polypropylene (glycol) interactions with dodecylphosphocholine micelles were shown to occur at a deep level by (1)H NMR using doxyl probes located at the head or the lipid extremity of the micelles. The polypropylene (glycol) also interacted with lipid bilayers in a manner dependent on the cholesterol content, as shown by differential scanning calorimetry using liposomes. This interaction destabilised the membrane and allowed the release of small molecules. Finally, molecular dynamic simulation of the copolymer L64 in the presence of dodecylphosphocholine showed that the hydrophobic core of the polymer formed an extremely tight cluster, whose dimensions excluded the possibility of polymer spanning across the lipidic micelles. The simulation positively correlated with the destabilising effect observed on the liposomal membrane models.


Assuntos
DNA/química , Bicamadas Lipídicas/química , Lipossomos/química , Poloxâmero/química , Varredura Diferencial de Calorimetria , Espectroscopia de Ressonância Magnética , Simulação de Dinâmica Molecular
17.
J Gene Med ; 12(6): 491-500, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20527042

RESUMO

BACKGROUND: Nonviral gene therapy still suffers from low efficiency. Methods that would lead to higher gene expression level of longer duration would be a major advance in this field. Lipidic vectors and physical methods have been investigated separately, and both induced gene expression improvement. METHODS: We sought to combine both chemical and physical methods. Cationic or anionic lipids can potentially destabilize the cell membrane and could consequently enhance gene delivery by a physical method such as electrotransfer. A plasmid model encoding luciferase was used, either free or associated with differently-charged lipoplexes before electrotransfer. RESULTS: Electrotransfer alone strongly enhanced gene expression after intramuscular and intradermal injection of naked DNA. On the other hand, cationic and anionic lipoplex formulations decreased gene expression after electrotransfer, whereas poorly-charged thiourea-based complexes, brought no benefit. Pre-injection of the lipids, followed by administration of naked DNA, did not modified gene expression induced by electroporation in the skin. CONCLUSIONS: The results obtained in the present study suggest that packing of DNA plasmid in lipoplexes strongly decreases the efficiency of gene electrotransfer, independently of the lipoplex charge. Non-aggregating complexes, such as poorly-charged thiourea-based complexes, should be preferred to increase DNA release.


Assuntos
Cátions/química , Eletroporação/métodos , Técnicas de Transferência de Genes , Lipossomos/química , Transfecção , Animais , Células CHO , Cátions/metabolismo , Cricetinae , Cricetulus , DNA/química , Feminino , Lipossomos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Músculo Esquelético/citologia , Músculo Esquelético/fisiologia , Plasmídeos/química , Plasmídeos/genética , Pele/citologia , Pele/metabolismo
18.
Biochim Biophys Acta ; 1800(5): 537-43, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20153812

RESUMO

BACKGROUND: Muscle transfection by electrotranfer is an efficient currently used procedure. Recently, the block copolymer pluronic L64 has been reported to improve muscle transfection. Both procedures are known to permeabilize muscle fibres. Relation between muscle transfection and permeabilization by electrotransfer and L64 was investigated herein. METHODS: Muscle transfection was evaluated by optical detection of the luciferase reporter gene activity. Muscle permeabilization was evaluated by the uptake of the T1 contrast agent gadolinium-Dotarem (Gd-DOTA) using Magnetic resonance imaging (MRI). Histological examination of muscle sections was also performed. RESULTS: Electrotransfer and L64 (at a 0.25% concentration) similarly improved muscle transfection, although the interindividual variability was higher for pluronic. On the same animals, the permeabilized volume to the Gd-DOTA was significantly increased after electrotransfer, and L64 from 0.1% to 1%. The concentration of the Gd-DOTA in the permeabilized volume was significantly increased after electrotransfer and L64 at 0.5% and 1%. By histological observation, the inflammation was maximum at day 3 after electrotransfer or L64 injection, and mostly reversed after 7 days. The permeabilized volume and the transfection level correlated for the set of all the conditions tested. However, no significant correlation was observed between Gd-DOTA concentration and transfection. GENERAL SIGNIFICANCE: It is possible to use successively on the same animals MRI and optical imaging for paired studies of muscle transfection and permeabilization. Permeabilization is possibly not related to gene transfer but it indicates membrane modification related to transfection by the electrotransfer or co-injection of DNA with the L64.


Assuntos
Meios de Contraste/farmacologia , Eletroporação/métodos , Compostos Heterocíclicos/farmacologia , Luciferases/biossíntese , Imageamento por Ressonância Magnética/métodos , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/metabolismo , Compostos Organometálicos/farmacologia , Poloxâmero/farmacologia , Animais , Feminino , Genes Reporter , Camundongos , Camundongos Endogâmicos BALB C , Fatores de Tempo
19.
Ultrasonics ; 50(2): 269-72, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19857885

RESUMO

Our study aimed at evaluating the use of ultrasound-assisted microbubbles gene transfer in mice Achilles tendons. Using a plasmid encoding luciferase gene, it was found that an efficient and stable gene expression for more than two weeks was obtained when tendons were injected with 10 microg of plasmid in the presence of 5x10(5) BR14 microbubbles with the following acoustic parameters: 1 MHz, 200 kPa, 40% duty cycle and 10 min of exposure time. The rate of gene expression was 100-fold higher than that obtained with naked plasmid injected alone without ultrasound or with ultrasound in absence of microbubbles. The long term expression of transgene makes ultrasound-assisted microbubble a suitable method for gene therapy in tendons.


Assuntos
Tendão do Calcâneo , Meios de Contraste/química , Fluorocarbonos/química , Expressão Gênica , Técnicas de Transferência de Genes , Terapia Genética/métodos , Microbolhas , Fosfolipídeos/química , Ultrassom , Animais , Desenho de Equipamento , Luciferases de Vaga-Lume/genética , Camundongos , Plasmídeos/administração & dosagem , Estatísticas não Paramétricas , Transfecção
20.
J Control Release ; 124(1-2): 81-7, 2007 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-17854939

RESUMO

The development of DNA vaccines requires appropriate delivery technologies. Electrotransfer is one of the most efficient methods of non-viral gene transfer. In the present study, intradermal DNA electrotransfer was first optimised. Strong effects of the injection method and the dose of DNA on luciferase expression were demonstrated. Pre-treatments were evaluated to enhance DNA diffusion in the skin but neither hyaluronidase injection nor iontophoresis improved efficiency of intradermal DNA electrotransfer. Then, DNA immunisation with a weakly immunogenic model antigen, luciferase, was investigated. After intradermal injection of the plasmid encoding luciferase, electrotransfer (HV 700 V/cm 100 micros, LV 200 V/cm 400 ms) was required to induce immune response. The response was Th1-shifted compared to immunisation with the luciferase recombinant protein. Finally, DNA electrotransfer in the skin, the muscle or the ear pinna was compared. Muscle DNA electrotransfer resulted in the highest luciferase expression and the best IgG response. Nevertheless electrotransfer into the skin, the muscle and the ear pinna all resulted in IFN-gamma secretion by luciferase-stimulated splenocytes suggesting that an efficient Th1 response was induced in all case.


Assuntos
Eletroporação/métodos , Pele/metabolismo , Vacinas de DNA/administração & dosagem , Animais , Citomegalovirus/genética , DNA/genética , Feminino , Expressão Gênica , Vetores Genéticos , Injeções Intradérmicas , Luciferases/genética , Camundongos , Camundongos Endogâmicos BALB C , Plasmídeos/genética , Vacinação
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