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1.
Life (Basel) ; 13(8)2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37629557

RESUMO

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is defined as urologic pain or discomfort in the pelvic region, associated with urinary symptoms and/or sexual dysfunction, lasting for at least 3 of the previous 6 months. The rate of symptoms related to prostatitis has a mean prevalence of 8-8.2%. CP/CPPS is most frequent in men younger than 50 years, among whom it is the most common urologic diagnosis. In the last decades, many studies have been published on CP/CPPS and its association with male infertility. The pathophysiologic relation between CP/CPPS and male infertility involves several aspects, which are not well studied yet. A reduction in semen parameters has been demonstrated in patients with CP/CPPS, and several mechanisms have been proposed to represent putative pathophysiological links between CP/CPPS and infertility, including male accessory gland inflammation, metabolic syndrome, inflammatory bowel disease, HPV co-infection and autoimmunity. In light of this evidence, a multidisciplinary approach is advocated for patients with known CP/CPPS, and particular attention is needed for male patients of infertile couples in order to evaluate male accessory glands correctly. In addition, it is advisable that future studies dealing with the treatment of CP/CPPS take into consideration all the different pathophysiological aspects implicated.

2.
Potato Res ; 65(3): 503-547, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35106009

RESUMO

In Northwestern Europe, Germany, France, the Netherlands, the UK and Belgium constitute the biggest five potato producers, with total potato crop production around 60% of EU-28 production before Brexit. Soil and climate conditions are highly favourable for potato growth in this region. Production is under driving forces of (i) the potato processing industry, particularly in Belgium; (ii) the innovation for fresh potato in the UK, France and Germany; (iii) the leadership of Germany and the Netherlands for starch potato; and (iv) the dominance of the Netherlands for seed production. Based on an industrial agri-food production system, the region has the highest potato yield levels worldwide and developed relevant trade networks for export of seed, fresh and processed potato products in and outside Europe. Conventional and intensive potato production is widespread over the region, whilst organic production started to develop in Germany and France. Whether the coming decades will be as successful as the last ones for sustainable potato production will depend on how the sector and stakeholders of the whole potato value-chain will overcome new issues and challenges. These are mainly soil quality and health conservation, consequences of climate change, increasing bans on the use of plant protection products, tightening environmental standards, food waste reduction and increasing trade tensions hampering the flow of potatoes around the world. After a detailed description of the potato production in the region, this paper contains a SWOT analysis aiming to identify potential solutions to overcome environmental, technical, economic, political and societal issues in the region for sustainable potato production in the coming years and decades.

3.
Anal Chem ; 92(15): 10743-10750, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32598142

RESUMO

The improvement of separation efficiency for protein analysis in capillary electrophoresis (CE) is a challenging topic in which protein adsorption onto the capillary wall plays a crucial role. In this work, a simple method allowing the quantification of the adsorption of proteins onto the coated or untreated inner surface of the fused silica capillary was developed based on the determination of the retention factor by measuring separation efficiency of individual proteins at different separation voltages (i.e., different linear velocities). This approach was applied to the quantification of the residual adsorption of four test proteins on five-layer polyelectrolyte coatings and bare fused silica capillary. It allows to get a fair ranking of the coating performances toward protein adsorption, whatever their apparent electrophoretic mobilities (migration times) are. Due to the existence of (even low) residual adsorption, the electrophoretic operating conditions (electric field, capillary length, and internal diameter) can be optimized to improve the separation performances resulting in experimental separation efficiency up to ∼600 000 plates.m-1 in conditions compatible with MS coupling. This approach represents a crucial step in the course to get antifouling coatings for protein separation in CE. It can be used for the evaluation and ranking of virtually any coating (neutral or charged) in CE.


Assuntos
Eletroforese Capilar/métodos , Proteínas/química , Proteínas/isolamento & purificação , Adsorção , Condutividade Elétrica , Dióxido de Silício/química
5.
J Chromatogr A ; 1561: 67-75, 2018 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-29843944

RESUMO

To better understand the focusing process and to determine the focusing position (zfoc) in Asymmetrical Flow Field-Flow Fractionation (AF4), theoretical and experimental studies were performed. A new theoretical expression that allows the calculation of zfoc in AF4 channels of any shape having an axial plane of symmetry was established. The equation was then applied to the particular case of a trapezoidal AF4 channel with tapered ends. The applicability of this equation was verified by comparing the calculated results with the experimental measures of the focusing position obtained using blue dextran dye under different flow conditions. The calculated values and the experimental results were in good agreement. The total uncertainty associated with the calculated zfoc was evaluated and was lower than 10%. A good repeatability and reproducibility of the focusing position was obtained. Moreover, the effects of the sample-injection position, the spacer thickness, the membrane aging, and the nature of the injected sample on the focusing position were investigated: zfoc was not influenced by these parameters, proving the universal applicability of the equation given in this work for predicting the focusing position, when the assumption of constancy of the cross-flow velocity at the membrane, which underlies this equation, is fulfilled. Additionally, it is notable that this theoretical expression is suitable for different models of AF4 channel and not peculiar to specific suppliers.


Assuntos
Corantes/análise , Dextranos/análise , Fracionamento por Campo e Fluxo/métodos , Modelos Teóricos , Corantes/química , Dextranos/química
6.
Int J Radiat Oncol Biol Phys ; 99(3): 590-595, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-29280453

RESUMO

PURPOSE: Concomitant cetuximab and radiation therapy (RT) can induce severe radiodermatitis in patients with head and neck cancer (HNC). OTD70DERM, a regenerating agent (RGTA), is a structural and functional analogue of glycosaminoglycans. Preclinical studies have shown that topical RGTA can markedly reduce radiation-induced mucosal and cutaneous toxicities without tumor protection. The present study aimed to evaluate the effect of topical RGTA on radiodermatitis in patients with HNC undergoing RT and cetuximab, for whom RT-induced skin reactions are frequent and/or severe. The primary endpoint was the incidence of grade ≥2 radiodermatitis. METHODS AND MATERIALS: We performed a multicenter, randomized, double-blind, placebo-controlled trial of patients with newly diagnosed HNC undergoing conventionally fractionated RT (70 Gy in 35 fractions) and weekly cetuximab. Patients were randomized 1:1 to receive topical OTD70DERM or placebo on irradiated skin once daily. The National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0, was used to evaluate radiodermatitis (photographs of radiation zone). The Dermatology Life Quality Index score was also evaluated. All the skin reactions seen on the photographs were scored independently by 2 outside experts. RESULTS: Of the 76 randomized patients (38 in each arm), 72 were available for the final radiodermatitis evaluation (37 in the RGTA arm and 35 in the placebo arm). No significant difference was observed concerning the incidence or duration of grade ≥2 radiodermatitis between the 2 arms (81% for RGTA vs 80% for placebo; P=.9). Also, no significant difference was found between the 2 arms regarding grade ≥2 radiodermatitis evaluated by the 2 experts using the photographs of 68 patients (76% vs 74%; P=.78). Finally, no significant difference was found in the Dermatology Life Quality Index score (score >10, 15% vs 20%; P=.45). CONCLUSIONS: Despite the good preclinical rationale, RGTA did not reduce the incidence and severity of radiodermatitis in patients with HNC.


Assuntos
Fármacos Dermatológicos/administração & dosagem , Glicosaminoglicanos/administração & dosagem , Neoplasias de Cabeça e Pescoço/radioterapia , Substâncias Protetoras/administração & dosagem , Radiodermite/tratamento farmacológico , Administração Tópica , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Imunológicos/administração & dosagem , Cetuximab/administração & dosagem , Fracionamento da Dose de Radiação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Protetores contra Radiação/administração & dosagem , Radiodermite/prevenção & controle
7.
Anal Chem ; 89(24): 13487-13493, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29120620

RESUMO

Taylor dispersion analysis (TDA) is an absolute method (no calibration needed) for the determination of the molecular diffusion coefficient (D) based on the band broadening of a solute in a laminar flow. TDA is virtually applicable to any solute with size ranging from angstrom to sub-micrometer. The higher sizing limit is restricted by the occurrence of possibly two regimes: convective and hydrodynamic chromatography (HDC) regimes, which have different physical origins that should not be confused. This work aims at clearly defining the experimental conditions for which these two regimes can play a role, alone or concomitantly. It also calculates the relative error on D due to the HDC regime according to the solute to capillary size ratio. It is demonstrated in this work that HDC does not significantly affect the TDA measurement as long as the hydrodynamic radius of the solute is lower than 0.0051 times the capillary radius. Experimental illustrations of the occurrence of the two regimes are given taking polystyrene nanoparticles as model solutes. Finally, application of TDA to the sizing of large real-life solutes is proposed, taking cubosomes as new drug nanocarriers of potential interest for drug delivery purposes.


Assuntos
Hidrodinâmica , Nanopartículas/química , Fosfatidilgliceróis/química , Poloxâmero/química , Cromatografia , Difusão , Tamanho da Partícula , Propriedades de Superfície
8.
Anal Chem ; 89(12): 6543-6550, 2017 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-28513151

RESUMO

In the separation sciences, sample species are separated according to their physicochemical properties, the nature of the selective field, and, if present, the properties of the medium in which they are dissolved or suspended. Separations may be carried out on a continuous basis in microfluidic devices or split-flow thin channel (SPLITT) devices by selectively transporting species in a direction transverse to the direction of flow of the suspending fluid. Separation is achieved in the so-called transport mode according to relative differences in mobility of the species under the influence of the applied field. Gravitational, centrifugal, thermal gradient, magnetic, electric, and dielectric fields may all be used for continuous SPLITT fractionation. We present here the theory for optimizing the operation of the relatively new technique of acoustic SPLITT fractionation for the continuous separation of non-Brownian materials. The theory is based on a quantitatively defined acoustophoretic mobility that is consistent with the generalized concept of mobility proposed by Giddings. Until now, acoustophoretic mobility has almost exclusively been used as a qualitative descriptor for velocity induced by an acoustic field. The quantitative definition presented here will contribute to the advancement of all forms of acoustofluidic separations.

9.
Immunol Res ; 65(1): 375-385, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27561787

RESUMO

Pulmonary hyalinizing granuloma (PHG) is a rare disease characterized by single or multiple benign lung nodules mimicking lung neoplasma. Histologic analysis reveals homogenous hyaline lamellae, usually surrounded by collection of plasma cells, lymphocytes and histiocytes in a perivascular distribution. The clinical and radiological findings have been described in small series, but the long-term outcomes have rarely been reported. The objectives were to describe the clinical, radiological and outcomes of PHG in new cases and through a literature review. Patients with PHG were found by a multicenter search among French departments of internal medicine, pulmonology and anatomo-pathology. Review of the literature was made through the National Library of Medicine's MEDLINE database using keywords "hyalinizing granuloma." Five news cases and 135 cases of the literature were found. There were 82 men and 57 women, mean age at the diagnosis 44.6 years (15-83). Patients were frequently asymptomatic (n = 39, 27.4 %). The nodule was unique in 37 cases (28.9 %) and multiple in 91 cases (71.1 %). 18FDG PET scan revealed hypermetabolism of the nodule in 9/15 cases (60 %). A systemic disease was associated in 65 cases (mainly mediastinal and retroperitoneal fibrosis, autoimmune, tumoral or infectious disease or thromboembolism). The outcomes were evaluated in 73 patients when follow-up was available: 14 patients had a surgical resection of the nodule. Forty-five patients did not receive any immunosuppressive drug. Among these patients, 2 improved, 29 were stable and 14 worsened. Corticosteroids were used as a monotherapy in 19 patients and led to radiological improvement in 8 cases, stabilization in 8 cases and worsening in 3 cases. Five patients were treated with corticosteroids and at least one immunosuppressive drug and 4 patients improved. PHG is a rare benign disease, mimicking lung neoplasma, frequently associated with systemic diseases.


Assuntos
Granuloma , Pneumopatias , Adolescente , Corticosteroides/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Granuloma/diagnóstico por imagem , Granuloma/tratamento farmacológico , Humanos , Hialina , Imunossupressores/uso terapêutico , Pulmão/diagnóstico por imagem , Pulmão/efeitos dos fármacos , Pulmão/patologia , Pneumopatias/diagnóstico por imagem , Pneumopatias/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios X , Adulto Jovem
10.
Anal Chem ; 87(16): 8489-96, 2015 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-26243023

RESUMO

Taylor dispersion analysis is an absolute and straightforward characterization method that allows determining the diffusion coefficient, or equivalently the hydrodynamic radius, from angstroms to submicron size range. In this work, we investigated the use of the Constrained Regularized Linear Inversion approach as a new data processing method to extract the probability density functions of the diffusion coefficient (or hydrodynamic radius) from experimental taylorgrams. This new approach can be applied to arbitrary polydisperse samples and gives access to the whole diffusion coefficient distributions, thereby significantly enhancing the potentiality of Taylor dispersion analysis. The method was successfully applied to both simulated and real experimental data for solutions of moderately polydisperse polymers and their binary and ternary mixtures. Distributions of diffusion coefficients obtained by this method were favorably compared with those derived from size exclusion chromatography. The influence of the noise of the simulated taylorgrams on the data processing is discussed. Finally, we discuss the ability of the method to correctly resolve bimodal distributions as a function of the relative separation between the two constituent species.


Assuntos
Difusão , Nanoestruturas/química , Polímeros/química , Algoritmos , Cromatografia em Gel , Hidrodinâmica , Modelos Teóricos
11.
Anal Chem ; 87(2): 1050-7, 2015 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-25569334

RESUMO

Quantitative analysis in capillary electrophoresis based on time-scale electropherograms generally uses time-corrected peak areas to account for the differences in apparent velocities between solutes. However, it could be convenient and much more relevant to change the time-scale electropherograms into mass relative distribution of the effective mobility or any other characteristic parameter (molar mass, chemical composition, charge density, ...). In this study, the theoretical background required to perform the variable change on the electropherogram was developed with an emphasis on the fact that both x and y axes should be changed when the time scale electropherograms are modified to get the distributions. Applications to the characterization of polymers and copolymers by different modes of capillary electrophoresis (CE) are presented, including the molar mass distribution of poly-L-lysine oligomers by capillary gel electrophoresis (CGE), molar mass distribution of end-charged poly-l-alanine by free solution CE, molar mass distribution of evenly charged polyelectrolytes by CGE, and charge density distribution of variously charged polyelectrolytes by free solution CE.


Assuntos
Eletroforese Capilar/métodos , Polilisina/análise , Polímeros/química , Modelos Teóricos
12.
Rev Prat ; 64(6): 802-6, 2014 Jun.
Artigo em Francês | MEDLINE | ID: mdl-25090765

RESUMO

The treatment of uterine cervical cancer evolved the last past twenty years. The management of early stages cervical cancer is based on surgery +/- after an initial brachytherapy in order to increase loco-regional control. A conservative treatment preserving uterine and ovarian functions is sometimes possible for young patients < 40 years old wishing to conceive. This strategy allows pregnancies with low recurrence rate. Finally, the use of the sentinel lymph node staging should be validated within the next few years. The treatment of locally advanced stages is based on concomitant chemoradiation therapy, which allows obtaining an important complete tumour response rate (90%). Thereafter, the irradiation modalities will depend on the para-aortic lymph nodes status diagnosed by PET-computed tomography +/- staging laparoscopic para-aortic lymphadenectomy. The use of completion surgery may be indicated in case of cervical residual disease and has to be balanced with its specific morbidity. All the decisions are made during a multidisciplinary tumour board.


Assuntos
Neoplasias do Colo do Útero/terapia , Colo do Útero/cirurgia , Quimiorradioterapia , Árvores de Decisões , Feminino , Humanos , Excisão de Linfonodo , Radioterapia Adjuvante , Neoplasias do Colo do Útero/patologia
13.
Anal Chem ; 86(13): 6471-8, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24937011

RESUMO

Taylor dispersion analysis is an increasingly popular characterization method that measures the diffusion coefficient, and hence the hydrodynamic radius, of (bio)polymers, nanoparticles, or even small molecules. In this work, we describe an extension to current data analysis schemes that allows size polydispersity to be quantified for an arbitrary sample, thereby significantly enhancing the potentiality of Taylor dispersion analysis. The method is based on a cumulant development similar to that used for the analysis of dynamic light scattering data. Specific challenges posed by the cumulant analysis of Taylor dispersion data are discussed, and practical ways to address them are proposed. We successfully test this new method by analyzing both simulated and experimental data for solutions of moderately polydisperse polymers and polymer mixtures.

14.
BMC Cancer ; 14: 427, 2014 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-24923533

RESUMO

BACKGROUND: Survival is poorer in elderly patients with head and neck squamous cell carcinomas [HNSCCs] than in younger patients. Possible explanations include a contribution of co-morbidities to mortality, frequent refusal of standard therapy, and the use of suboptimal treatments due to concern about toxicities. The Comprehensive Geriatric Assessment [CGA] is a multidimensional assessment of general health that can help to customise treatment and follow-up plans. The CGA has been proven effective in several health settings but has not been evaluated in randomised studies of patients with cancer. Our aim here was to assess the impact of the CGA on overall survival, function, and nutritional status of elderly patients with HNSCC. METHODS/DESIGN: EGeSOR is an open-label, multicentre, randomised, controlled, parallel-group trial in patients aged 70 years or older and receiving standard care for HNSCC. The intervention includes four components: the CGA conducted by a geriatrician before cancer treatment, participation of the same geriatrician in cancer treatment selection, a standardised geriatric therapeutic intervention designed by the same geriatrician; and geriatric follow-up for 24 months. The primary endpoint, assessed after 6 months, is a composite criterion including death, functional impairment [Activities of Daily Living score decrease ≥ 2], and weight loss ≥ 10%. Secondary endpoints include progression-free survival, unscheduled admissions, quality of life, treatment toxicities, costs, and completion of the planned cancer treatment. A centralised online system is used to perform 1:1 randomisation with a minimisation algorithm for centre, age, T and N stages, and tumour site [oral, oropharyngeal, hypopharyngeal, or laryngeal]. The estimated sample size is 704 patients, who are being recruited by 14 centres in 9 French cities. DISCUSSION: EGeSOR is the first randomised trial of the CGA in elderly cancer patients. We expect the CGA to have direct clinical benefits on the management of elderly patients with HNSCC. If this expectation is fulfilled, the trial may lead to modifications of the management model for elderly patients with cancer. TRIAL REGISTRATION: Trial registration: NCT02025062.


Assuntos
Protocolos Clínicos , Avaliação Geriátrica , Neoplasias de Cabeça e Pescoço/epidemiologia , Mortalidade , Estado Nutricional , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Humanos
15.
Analyst ; 139(14): 3552-62, 2014 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-24867264

RESUMO

In this work, we investigate the possibility of optimizing the operating conditions, namely mobilizing pressure, capillary length and capillary radius, for performing Taylor dispersion analysis on solutes having hydrodynamic diameter, 2Rh, between 1 and 100 nm. Optimizing Taylor dispersion analysis means finding the set of operating conditions that verify the conditions of validity of this method, and finding the most appropriate conditions that may enhance or maximize the separation performances. Our conclusion is that the performances of Taylor dispersion analysis are independent of the operating conditions, as far as the conditions of validity of the method are verified. The inequalities defining the set of acceptable operating conditions are given in this work as a function of the maximal relative error on the diffusion coefficient, D, fixed by the user. These inequalities define operating zones that were represented for three typical capillary diameters (25, 50 and 100 µm). Within these zones, all experiments should lead to similar results on D (or Rh) and similar separation performances. It was concluded that assuming a 3% relative error on the determination of D, a 60 cm × 50 µm i.d. capillary can be used by default for performing TDA of analytes in the 1-100 nm diameter range with mobilizing pressure in the 50-100 mbar range.


Assuntos
Eletroforese Capilar/métodos , Algoritmos , Difusão , Eletroforese Capilar/instrumentação , Pressão
16.
Analyst ; 139(1): 116-27, 2014 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-24162070

RESUMO

A theoretical and experimental study of continuous two-dimensional thermal field-flow fractionation (2D-ThFFF) is presented. Separation takes place in radial flow between two closely spaced discs, one of which is heated and the other cooled in order to maintain a temperature gradient across the channel. The cooled disc, which serves as the accumulation wall, is rotated relative to the other to create a shear component to the fluid flow. Under the influence of the thermal gradient and flow components, the sample components spiral outwards along different paths to the outer rim of the channel to be collected. The general principle of operation is described and an approximate theoretical model formulated for predicting the outlet position for the path of each sample component. The influence of the principal operational parameters, such as radial and angular flow rates and thermal gradient, on the deflection angle of the sample trajectory is investigated. Fractionation is demonstrated for polystyrene polymer standards in a binary solvent consisting of cyclohexane and ethylbenzene. Experimental results are compared with theoretical predictions.

17.
J Chromatogr A ; 1297: 46-55, 2013 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-23688684

RESUMO

In chromatographic columns, when the eluting strength of the sample solvent is larger than that of the carrier liquid, a deformation of the analyte zone occurs because its frontal part moves at a relatively high velocity due to a low retention factor in the sample solvent while the rear part of the analyte zone is more retained in the carrier liquid and hence moves at a lower velocity. The influence of this solvent strength effect on the separation of analytes is studied here theoretically using a mass balance model describing the spatio-temporal evolution of the eluent, the sample solvent and the analyte. The viscosity of the sample solvent and carrier fluid is supposed to be the same (i.e. no viscous fingering effects are taken into account). A linear isotherm adsorption with a retention factor depending upon the local concentration of the liquid phase is considered. The governing equations are numerically solved by using a Fourier spectral method and parametric studies are performed to analyze the effect of various governing parameters on the dispersion and skewness of the analyte zone. The distortion of this zone is found to depend strongly on the difference in eluting strength between the mobile phase and the sample solvent as well as on the sample volume.


Assuntos
Cromatografia Líquida/instrumentação , Cromatografia Líquida/métodos , Modelos Teóricos , Solventes/química , Adsorção , Viscosidade
18.
J Phys Chem A ; 116(25): 6540-51, 2012 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-22506593

RESUMO

A simple theoretical model for the size selectivity, S(d), in the lift mode of retention in field-flow fractionation (FFF) is developed on the basis of the near-wall lift force expression. S(d) is made up of two contributions: the flow contribution, S(d,f), arising from the variation of the flow velocity at center of particle due to a change in particle position with particle size, and a slip contribution, S(d,s), arising from the concomitant change in the extent of retardation due to the presence of a nearby channel wall. The slip contribution is minor, but not negligible, and amounts to 10-20% of the overall size selectivity. It contributes to reduce S(d) in sedimentation FFF but to enhance it in flow FFF. S(d) would steadily increase with particle size if the flow profile was linear (Couette flow). Because of the curvature of the flow profile encountered in the classical Poiseuille flow, S(d) exhibits a maximum at some specific particle size. The model predicts a significant difference in S(d) between sedimentation FFF and flow FFF, arising from the different functional dependences of the field force with particle size between these two methods. The predictions are in good agreement with the various S(d) values reported in the literature in both sedimentation and flow FFF. On the basis of the model, guidelines are given for adjusting the operating parameters (carrier flow rate and field strength) to optimize the size selectivity. Finally, it is found that S(d) generally decreases with decreasing channel thickness.

19.
Blood ; 118(26): 6860-70, 2011 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-22045983

RESUMO

Mammalian target of rapamycin (mTOR) is a downstream serine/threonine kinase of the PI3K/Akt pathway that integrates signals from the tumor microenvironment to regulate multiple cellular processes. Rapamycin and its analogs have not shown significant activity in multiple myeloma (MM), likely because of the lack of inhibition of TORC2. In the present study, we investigated the baseline activity of the PI3K/Akt/mTOR pathway TORC1/2 in MM cell lines with different genetic abnormalities. TORC1/2 knock-down led to significant inhibition of the proliferation of MM cells, even in the presence of BM stromal cells. We also tested INK128, a dual TORC1/2 inhibitor, as a new therapeutic agent against these MM cell lines. We showed that dual TORC1/2 inhibition is much more active than TORC1 inhibition alone (rapamycin), even in the presence of cytokines or stromal cells. In vitro and in vivo studies showed that p-4EBP1 and p-Akt inhibition could be predictive markers of TORC2 inhibition in MM cell lines. Dual TORC1/2 inhibition showed better inhibition of adhesion to BM microenvironmental cells and inhibition of homing in vivo. These studies form the basis for further clinical testing of TORC1/2 inhibitors in MM.


Assuntos
Mieloma Múltiplo/metabolismo , Proteínas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Camundongos SCID , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/patologia , Complexos Multiproteicos , Fosfatidilinositol 3-Quinases/metabolismo , Fosfoproteínas/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas/antagonistas & inibidores , Proteínas/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , Proteína Companheira de mTOR Insensível à Rapamicina , Proteína Regulatória Associada a mTOR , Transdução de Sinais/efeitos dos fármacos , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
20.
J Chromatogr A ; 1218(27): 4117-25, 2011 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-21256498

RESUMO

Elution time measurements of colloidal particles injected in a symmetrical flow field-flow fractionation (flow FFF) system when the inlet and outlet cross-flow connections are closed have been performed. This no-field method has been proposed earlier for void time (and void volume) determination in flow FFF Giddings et al. (1977). The elution times observed were much larger than expected on the basis of the channel geometrical volume and the flow rate. In order to explain these discrepancies, a flow model allowing the carrier liquid to flow through the porous walls toward the reservoirs located behind the porous elements and along these reservoirs was developed. The ratio between the observed elution time and expected one is found to depend only on a parameter which is a function of the effective permeability and thickness of the porous elements and of the channel thickness and length. The permeabilities of the frits used in the system were measured. Their values lead to predicted elution times in reasonable agreement with experimental ones, taking into account likely membrane protrusion inside the channel on system assembly. They comfort the basic feature of the flow model, in the no-field case. The carrier liquid mostly bypasses the channel to flow along the system mainly in the reservoir. It flows through the porous walls toward the reservoirs near channel inlet and again through the porous walls from the reservoirs to the channel near channel outlet before exiting the system. In order to estimate the extent of this bypassing process, it is desirable that the hydrodynamic characteristics of the permeable elements (permeability and thickness) are provided by flow FFF manufacturers. The model applies to symmetrical as well as asymmetrical flow FFF systems.


Assuntos
Fracionamento por Campo e Fluxo/métodos , Modelos Químicos , Coloides/química , Fracionamento por Campo e Fluxo/instrumentação , Permeabilidade , Porosidade , Pressão , Fatores de Tempo
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