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1.
Artif Organs ; 2024 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-38825886

RESUMO

BACKGROUND: Functional Electrical Stimulation (FES) represents a promising technique for promoting functional recovery in individuals with neuromuscular diseases. Traditionally, current pulses are delivered through self-adhesive hydrogel Ag/AgCl electrodes, which allow a good contact with the skin, are easy-to-use and have a moderate cost. However, skin adherence decreases after a few uses and skin irritations can originate. Recently, textile electrodes have become an attractive alternative as they assure increased durability, easy integration into clothes and can be conveniently cleaned, improving the wearability of FES. However, as various manufacture processes were attempted, their clear validation is lacking. This proof-of-concept study proposes a novel set of ink-based printed textile electrodes and compares them to adhesive hydrogel electrodes in terms of impedance, stimulation performance and perceived comfort. METHODS: The skin-electrode impedance was evaluated for both types of electrodes under different conditions. These electrodes were then used to deliver FES to the Rectus Femoris of 14 healthy subjects to induce its contraction in both isometric and dynamic conditions. This allowed to compare the two types of electrodes in terms of sensory, motor, maximum and pain thresholds, FES-induced range of motion during dynamic tests, FES-induced torque during isometric tests and perceived stimulation comfort. RESULTS: No statistically significant differences were found both in terms of stimulation performance (Wilcoxon test) and comfort (Generalized Linear Mixed Model). CONCLUSION: The results showed that the proposed ink-based printed textile electrodes can be effectively used as alternative to hydrogel ones. Further experiments are needed to evaluate their durability and their response to sterilizability and stretching tests.

2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 2865-2868, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30440999

RESUMO

Wearable systems are gaining broad acceptance for monitoring physiological parameters in several medical applications. Among a number of approaches, smart textiles have attracted interest because they are comfortable and do not impair patients' movements. In this article, we aim at developing a smart textile for respiratory monitoring based on a piezoresistive sensing element. Firstly, the calibration curve of the system and its hysteresis have been investigated. Then, the proposed system has been assessed on 6 healthy subjects. The volunteers were invited to wear the system to monitor their breathing rate. The results of the calibration show a good mean sensitivity (i.e., approximately 0.11V·%-1); although the hysteresis is not negligible, the system can follow the cycles also at high rates (up to 36 cycle·min-1). The feasibility assessment on 6 volunteers (two trials for each one) shows that the proposed system can estimate with good accuracy the breathing rate. Indeed, the results obtained by the proposed system were compared with the ones collected with a spirometer, used as reference. Considering all the experiments, a mean percentage error was approximately 2%. In conclusion, the proposed system has several valuable features (e.g., the sensing element is lightweight, the sensitivity is high, and it is possible to develop comfortable smart textile); in addition, the promising performances considering both metrological properties and assessment on volunteers foster future tests focused on: i) the possibility of developing and system embedding several sensing elements, and ii) to develop a wireless acquisition system, to allow comfortable and long-term acquisition in both patients and during sport activities.


Assuntos
Prata , Dispositivos Eletrônicos Vestíveis , Humanos , Monitorização Fisiológica , Taxa Respiratória , Têxteis
3.
Recent Pat Anticancer Drug Discov ; 12(2): 148-168, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28164756

RESUMO

BACKGROUND: Integrins are heterodimeric cell surface receptors that mediate cell-cell and cell-extracellular matrix adhesion. These molecules play a role in processes such as cell growth and proliferation, differentiation, migration, cell trafficking, besides contributing to angiogenesis and tumor development. Given their biological role, integrins have been proposed as amenable targets in medicinal chemistry. In particular, αvß3, αvß5, αvß6 and α5ß1, integrins involved in tumor angiogenesis and metastasis, have been the subject of studies aimed at the discovery of novel cancer therapeutics. A large number of peptides and peptidomimetics based on the RGD (Arg-Gly-Asp) recognition sequence were developed in the past two decades as integrin ligands. Though such ligands have not been satisfactory as anti-angiogenic agents, their use as tools to achieve selective tumor targeting of anticancer drugs has been explored. OBJECTIVE: In this review, we summarize recent literature and patent applications in which integrin peptidic and peptidomimetic ligands were conjugated to chemotherapeutic agents both with stable or cleavable bonds to achieve tumor targeted drug delivery. METHODS: Relevant recent patents and literature in this field have been considered spanning the search from 2000 to 2016. Literature and patents were examined according to the different classes of cytotoxic drug targeted to integrins. CONCLUSION: In spite of the promising features of the conjugates, none of them has entered clinical trials. New efforts are focused on innovative approaches in the field such as the synthesis of new integrin ligands able to target a single integrin type or the employment of nanoparticles based drug delivery systems.


Assuntos
Antineoplásicos/administração & dosagem , Integrinas/metabolismo , Neoplasias/tratamento farmacológico , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/química , Inibidores da Angiogênese/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Sistemas de Liberação de Medicamentos , Humanos , Nanopartículas , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/patologia , Patentes como Assunto , Peptídeos/administração & dosagem , Peptídeos/química , Peptidomiméticos/administração & dosagem , Peptidomiméticos/química
4.
Org Biomol Chem ; 13(27): 7530-41, 2015 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-26074454

RESUMO

Integrins are associated with tumour cell survival and progression, and their expression has been shown to be increased in tumours. Thus, four novel conjugates of the tripeptide integrin ligand Arg-Gly-Asp (RGD) and the cytotoxic agent paclitaxel (cRGD-PTX) were prepared to investigate the potential of the multivalent presentation of the RGD moiety in improving the antitumor efficacy of PTX by tumour targeting. PTX was conjugated to two or four integrin recognizing ligands. The influence of multivalent presentation on in vitro αvß3-receptor affinity was confirmed. For all the conjugates compared to the previously synthesized monovalent counterparts, an enhancement of the binding strength was observed; this behaviour was more pronounced when considering the tetravalent presented RGD-conjugate. Cell growth inhibition assays on a panel of human tumour cell lines showed remarkable cytotoxic activity for all conjugates with IC50 values in a nanomolar range. Among the four conjugates, the bivalent derivative 3b was selected for in vivo studies in an ovarian carcinoma cell model xenografted in immunodeficient mice. A marked antitumor activity was observed, similar to that of PTX, but with a much more favourable toxicity profile. Overall, the novel cRGD-PTX conjugates disclosed here represent promising candidates for further advancement in the domain of targeted anti-tumour therapy.


Assuntos
Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Paclitaxel/síntese química , Paclitaxel/farmacologia , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/farmacologia , Multimerização Proteica , Animais , Antineoplásicos/farmacologia , Biotinilação , Linhagem Celular Tumoral , Feminino , Humanos , Integrina alfaVbeta3/metabolismo , Camundongos Nus , Peptídeos Cíclicos/química , Vitronectina/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Ann Oncol ; 26(7): 1363-71, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25846551

RESUMO

BACKGROUND: The majority of patients with stage III-IV epithelial ovarian cancer (EOC) relapse after initially responding to platinum-based chemotherapy, and develop resistance. The genomic features involved in drug resistance are unknown. To unravel some of these features, we investigated the mutational profile of genes involved in pathways related to drug sensitivity in a cohort of matched tumors obtained at first surgery (Ft-S) and second surgery (Sd-S). PATIENTS AND METHODS: Matched biopsies (33) taken at Ft-S and Sd-S were selected from the 'Pandora' tumor tissue collection. DNA libraries for 65 genes were generated using the TruSeq Custom Amplicon kit and sequenced on MiSeq (Illumina). Data were analyzed using a high-performance cluster computing platform (Cloud4CARE project) and independently validated. RESULTS: A total of 2270 somatic mutations were identified (89.85% base substitutions 8.19% indels, and 1.92% unknown). Homologous recombination (HR) genes and TP53 were mutated in the majority of Ft-S, while ATM, ATR, TOP2A and TOP2B were mutated in the entire dataset. Only 2% of mutations were conserved between matched Ft-S and Sd-S. Mutations detected at second surgery clustered patients in two groups characterized by different mutational profiles in genes associated with HR, PI3K, miRNA biogenesis and signal transduction. CONCLUSIONS: There was a low level of concordance between Ft-S and Sd-S in terms of mutations in genes involved in key processes of tumor growth and drug resistance. This result suggests the importance of future longitudinal analyses to improve the clinical management of relapsed EOC.


Assuntos
Adenocarcinoma de Células Claras/genética , Adenocarcinoma Mucinoso/genética , Cistadenocarcinoma Seroso/genética , Neoplasias do Endométrio/genética , Genes Neoplásicos/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mutação/genética , Neoplasias Ovarianas/genética , Adenocarcinoma de Células Claras/mortalidade , Adenocarcinoma de Células Claras/secundário , Adenocarcinoma de Células Claras/terapia , Adenocarcinoma Mucinoso/mortalidade , Adenocarcinoma Mucinoso/secundário , Adenocarcinoma Mucinoso/terapia , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biópsia , Terapia Combinada , Cistadenocarcinoma Seroso/mortalidade , Cistadenocarcinoma Seroso/secundário , Cistadenocarcinoma Seroso/terapia , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias do Endométrio/mortalidade , Neoplasias do Endométrio/secundário , Neoplasias do Endométrio/terapia , Feminino , Seguimentos , Recombinação Homóloga , Humanos , Estudos Longitudinais , Metástase Linfática , Pessoa de Meia-Idade , Gradação de Tumores , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/terapia , Estadiamento de Neoplasias , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/terapia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
6.
J Pharmacol Exp Ther ; 348(3): 360-71, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24345465

RESUMO

Since response to platinum-based therapy in non-small-cell lung cancer (NSCLC) is poor, the present study was designed to rationally identify novel drug combinations in cell models including the A549 cell line and the cisplatin-resistant subline A549/Pt, characterized by reduced sensitivity to cisplatin-induced apoptosis and by upregulation of efflux transporters of the ATP binding cassette (ABC) superfamily. Given the molecular features of these cells, we focused on compounds triggering apoptosis through different mechanisms, such as the mitochondria-targeting drug arsenic trioxide and the phenanthridine analog sanguinarine, which induce apoptosis through the extrinsic pathway. Sanguinarine, not recognized by ABC transporters, could overcome cisplatin resistance and, when used in combination with arsenic trioxide, was synergistic in A549 and A549/Pt cells. The arsenic trioxide/sanguinarine cotreatment upregulated genes implicated in apoptosis activation through the extrinsic pathway. Drug combination experiments indicated that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) treatment improved arsenic trioxide/sanguinarine efficacy, a feature associated with a striking apoptosis induction, particularly in the cisplatin-resistant variant. Thus, a synergistic interaction between sanguinarine and arsenic trioxide could be obtained independent of relative cell sensitivity to arsenic trioxide, and an enhanced apoptosis induction could be achieved in combination with TRAIL through modulation of the extrinsic apoptotic pathway. Antitumor activity studies supported the interest of drug combinations including TRAIL in NSCLC, indicating that drug-resistant NSCLC cells can efficiently be killed by the combination of proapoptotic agents. Our results suggest that the molecular changes occurring in treated cells may be exploited to rationally hit surviving cells.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Arsenicais/farmacologia , Benzofenantridinas/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Isoquinolinas/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Óxidos/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Trióxido de Arsênio , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Cisplatino/farmacologia , Dano ao DNA , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia
7.
Cell Death Dis ; 4: e920, 2013 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-24232096

RESUMO

Smac mimetics (SMs) comprise a class of small molecules that target members of the inhibitor of apoptosis family of pro-survival proteins, whose expression in cancer cells hinders the action of conventional chemotherapeutics. Herein, we describe the activity of SM83, a newly synthesised dimeric SM, in two cancer ascites models: athymic nude mice injected intraperitoneally with IGROV-1 human ovarian carcinoma cells and immunocompetent BALB/c mice injected with murine Meth A sarcoma cells. SM83 rapidly killed ascitic IGROV-1 and Meth A cells in vivo (prolonging mouse survival), but was ineffective against the same cells in vitro. IGROV-1 cells in nude mice were killed within the ascites by a non-apoptotic, tumour necrosis factor (TNF)-dependent mechanism. SM83 administration triggered a rapid inflammatory event characterised by host secretion of TNF, interleukin-1ß and interferon-γ. This inflammatory response was associated with the reversion of the phenotype of tumour-associated macrophages from a pro-tumoural M2- to a pro-inflammatory M1-like state. SM83 treatment was also associated with a massive recruitment of neutrophils that, however, was not essential for the antitumoural activity of this compound. In BALB/c mice bearing Meth A ascites, SM83 treatment was in some cases curative, and these mice became resistant to a second injection of cancer cells, suggesting that they had developed an adaptive immune response. Altogether, these results indicate that, in vivo, SM83 modulates the immune system within the tumour microenvironment and, through its pro-inflammatory action, leads cancer cells to die by necrosis with the release of high-mobility group box-1. In conclusion, our work provides evidence that SMs could be more therapeutically active than expected by stimulating the immune system.


Assuntos
Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Necrose/induzido quimicamente , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Materiais Biomiméticos/uso terapêutico , Western Blotting , Linhagem Celular Tumoral , Células Cultivadas , Feminino , Células HCT116 , Humanos , Imunidade Inata/efeitos dos fármacos , Inflamação/induzido quimicamente , Proteínas Inibidoras de Apoptose , Camundongos , Camundongos Endogâmicos BALB C , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Curr Med Chem ; 20(12): 1541-65, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23432590

RESUMO

Poisoning of DNA topoisomerase I is the mechanism by which camptothecins interfere with tumor growth. Although the clinical use of camptothecins has had a significant impact on cancer therapy, de novo or acquired clinical resistance to these drugs is common. Clinical resistance to camptothecins is still a poorly understood phenomenon, likely involving pharmacological and tumor-related factors. Experimental models including yeast and mammalian cell cultures suggest three general mechanisms of camptothecin resistance: i) reduced cellular accumulation of drugs, ii) alteration in the structure/expression of topoisomerase I, and iii) alterations in the cellular response to camptothecin-DNA-ternary complex formation. Some lines of evidence have also suggested links between cellular camptothecin resistance, the existence of a subset of tumor-initiating cells and miRNA deregulation. In this regard, a better definition of the molecular events clarifying the regulation of tumorigenesis and gene expression might contribute to gain insight into the molecular mechanisms on the basis of camptothecin resistance of tumors and to identify new molecular tools for targeting cancer cells. The relevance of these mechanisms to clinical drug resistance has not yet been completely defined, but their evaluation in clinical specimens should help to define personalized treatments including camptothecins as single agents or in combination with other cytotoxic and target-specific anticancer agents. The present review focuses on the cellular/ molecular aspects involved in resistance of tumor cells to camptothecins, including the potential role of cancer stem cells and deregulated miRNAs, and on the approaches proposed for overcoming resistance.


Assuntos
Antineoplásicos/farmacologia , Camptotecina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Proteínas Sanguíneas/metabolismo , Camptotecina/química , Camptotecina/metabolismo , DNA/metabolismo , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo I/metabolismo , Regulação para Baixo , Humanos , MicroRNAs/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo
9.
Curr Med Chem ; 19(21): 3488-501, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22680917

RESUMO

Camptothecins are still among the most widely prescribed and effective anticancer drugs. Unfortunately, important drawbacks including water insolubility, lactone instability, reversibility of the drug-target interaction, drug resistance and toxicity are responsible for treatment failure and often require suspension of the drug administration itself. In order to overcome such drawbacks, several options in chemical manipulation of natural camptothecin have been explored, and effective compounds have been identified in a novel series of 7-oxyiminomethyl derivatives. Among the compounds of this series, the hydrophilic derivative namitecan (7 (2-aminoethoxy) iminomethyl camptothecin) has been selected for further development. The relevant features of namitecan are: 1) marked cytotoxic potency - likely related to multiple factors, including i) a potent inhibition of topoisomerase I, ii) a persistent stabilization of the cleavable complex, iii) an increased intracellular accumulation, and iv) a peculiar subcellular localization; 2) enhanced lactone stability and favorable pharmacokinetics; 3) remarkable antitumor efficacy in a large panel of human tumor xenografts (including tumor models relatively resistant to topotecan and irinotecan), particularly on squamous cell carcinomas. The clinical development of namitecan is currently ongoing. Namitecan exhibited an acceptable toxicity profile, with neutropenia being the dose-limiting toxic effect, and clinical benefit was appreciable in patients with different tumor types, particularly bladder and endometrium carcinomas. In this article, we review the relevant features of namitecan, with particular reference to its advantages compared with the two analogues (topotecan and irinotecan) approved for clinical use.


Assuntos
Antineoplásicos/farmacologia , Camptotecina/análogos & derivados , Inibidores Enzimáticos/farmacologia , Animais , Antineoplásicos/química , Camptotecina/química , Camptotecina/farmacologia , Proliferação de Células/efeitos dos fármacos , DNA Topoisomerases Tipo I/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/química , Humanos , Modelos Moleculares , Relação Estrutura-Atividade
10.
Curr Med Chem ; 19(8): 1238-57, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22204335

RESUMO

DNA topoisomerase I is required for DNA relaxation during a variety of cellular functions. The identification of camptothecins as specific enzyme poisons and their clinical efficacy have stimulated extensive efforts to exploit topoisomerase I as a therapeutic target for cancer. However, several limitations of camptothecins, such as low solubility and stability, high toxicity, and the occurrence of resistance, have encouraged the development of non-camptothecin topoisomerase I inhibitors. Different natural and synthetic compounds (e.g., indolocarbazoles, dibenzonaphthyridine and indenoisoquinoline) have been extensively studied as alternatives to camptothecins and have been proved to be promising therapeutic agents. In this review, we comparatively evaluate the preclinical results obtained with the different non-camptothecin poisons proposed thus far as topoisomerase I inhibitors, with special reference to cellular pharmacology, and discuss the perspective for their use in the clinical setting.


Assuntos
DNA Topoisomerases Tipo I/metabolismo , Inibidores da Topoisomerase/farmacologia , Animais , Humanos , Estrutura Molecular , Inibidores da Topoisomerase/química
11.
Curr Med Chem ; 18(27): 4237-49, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21838682

RESUMO

ATP-binding cassette (ABC) transporters are a large family of proteins implicated in physiological cellular functions. Selected components of the family play a well-recognized role in extruding conventional cytotoxic antitumor agents and molecularly targeted drugs from cells. Some lines of evidence also suggest links between transporters and tumor cell survival, in part unrelated to efflux. However, the study of the precise mechanisms regulating the function of drug transporters (e.g., posttranslational modifications such as glycosylation) is still in its infancy. A better definition of the molecular events clarifying the regulation of transporter levels including regulation by microRNAs may contribute to provide new molecular tools to target such a family of transporters. The present review focuses on the biological aspects that implicate ABC transporters in resistance of tumor cells, including cancer stem cells. Molecular analysis of well-known preclinical systems as well as of cancer stem cell models supports the notion that ABC transporters represent amenable targets for modulation of the efficacy of antitumor agents endowed with different molecular features. Recent achievements regarding tumor cell biology are expected to provide a rationale for developing novel inhibitors that target ABC transporters implicated in drug resistance.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/metabolismo , Terapia de Alvo Molecular/métodos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Humanos , Neoplasias/genética , Neoplasias/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Transdução de Sinais/efeitos dos fármacos
12.
J Neurosci Methods ; 201(1): 239-50, 2011 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-21816172

RESUMO

Brain-Computer Interfaces (BCIs) are systems which can provide communication and environmental control to people with severe neuromuscular diseases. The current study proposes a new BCI-based method for psychometric assessment when traditional or computerized testing cannot be used owing to the subject's output impairment. This administration protocol was based on, and validated against, a widely used clinical test (Raven Colored Progressive Matrix) in order to verify whether BCI affects the brain in terms of cognitive resource with a misstatement result. The operating protocol was structured into two phases: phase 1 was aimed at configuring the BCI system on the subject's features and train him/her to use it; during phase 2 the BCI system was reconfigured and the test performed. A step-by-step checking procedure was adopted to verify progressive inclusion/exclusion criteria and the underpinning variables. The protocol was validated on 19 healthy subjects and the BCI-based administration was compared with a paper-based administration. The results obtained by both methods were correlated as known for traditional assessment of a similarly culture free and reasoning based test. Although our findings need to be validated on pathological participants, in our healthy population the BCI-based administration did not affect performance and added a further control of the response due to the several variables included and analyzed by the computerized task.


Assuntos
Encéfalo/fisiologia , Cognição/fisiologia , Testes Neuropsicológicos/normas , Desempenho Psicomotor/fisiologia , Interface Usuário-Computador , Adolescente , Adulto , Humanos , Masculino , Adulto Jovem
13.
Biotechnol Prog ; 27(1): 95-103, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21312359

RESUMO

The influence of four variables, specifically PEG molar mass (400, 1,000, and 8,000 g/mol), concentrations of PEG and phosphate salts (15, 20, and 25% for both), and agitation intensity (110, 150, and 200 rpm), on clavulanic acid (CA) extraction by extractive fermentation with PEG/phosphate salts aqueous two-phase system was investigated in shaken flasks using a 2(4-1) -fractional factorial design. After selection of the two most significant variables (agitation intensity and PEG molar mass), an optimization study conducted according to a 2(2) -central composite design revealed that 25% PEG 8,000 g/mol and phosphate salts at 240 rpm (run 6) were the best conditions for the extractive fermentation, leading to the best results in terms of partition coefficient (k = 8.2), yield of CA in the PEG-rich phase (η(T) = 93%) and productivity (P = 5.3 mg/Lh). As a first attempt to make a scale-up of these results, the effectiveness of the extractive fermentation was then checked in a bench-scale bioreactor under conditions as close as possible to the optimum ones determined in flasks. The highest CA concentration obtained in the PEG-rich phase (691 mg/L) was 30% higher than in flasks, thus demonstrating the potential of such a new process, integrating the production and extraction steps, as a promising, low-cost tool to obtain high yields of this and similar products.


Assuntos
Ácido Clavulânico/metabolismo , Streptomyces/metabolismo , Fermentação , Polietilenoglicóis/química , Água
14.
Artigo em Inglês | MEDLINE | ID: mdl-22255924

RESUMO

Fetal heart rate monitoring is fundamental to infer information about fetal health state during pregnancy. The cardiotocography (CTG) is the most common antepartum monitoring technique. Abdominal ECG recording represents the most valuable alternative to cardiotocography, as it allows passive, non invasive and long term fetal monitoring. Unluckily fetal ECG has low SNR and needs to be extracted from abdominal recordings using ad hoc algorithms. This work describes a prototype of a wearable fetal ECG electrocardiograph. The system has flat band frequency response between 1-60 Hz and guarantees good signal quality. It was tested on pregnant women between the 30(th) and 34(th) gestational week. Several electrodes configurations were tested, in order to identify the best solution. Implementation of a simple algorithm for FECG extraction permitted the reliable detection of maternal and fetal QRS complexes. The system will allow continuative and deep screening of fetal heart rate, introducing the possibility of home fetal monitoring.


Assuntos
Eletrocardiografia/métodos , Monitorização Fetal/instrumentação , Monitorização Fetal/métodos , Algoritmos , Eletrodos , Desenho de Equipamento , Feminino , Frequência Cardíaca Fetal , Humanos , Modelos Estatísticos , Gravidez , Terceiro Trimestre da Gravidez , Processamento de Sinais Assistido por Computador , Razão Sinal-Ruído , Telemedicina/métodos , Interface Usuário-Computador
15.
Braz. j. microbiol ; 41(3): 519-530, Oct. 2010. ilus, tab
Artigo em Inglês | LILACS | ID: lil-549393

RESUMO

This review aims at providing an overview on the microbial production of vanillin, a new alternative method for the production of this important flavor of the food industry, which has the potential to become economically competitive in the next future. After a brief description of the applications of vanillin in different industrial sectors and of its physicochemical properties, we described the traditional ways of providing vanillin, specifically extraction and chemical synthesis (mainly oxidation) and compared them with the new biotechnological options, i.e., biotransformations of caffeic acid, veratraldehyde and mainly ferulic acid. In the second part of the review, emphasis has been addressed to the factors most influencing the bioproduction of vanillin, specifically the age of inoculum, pH, temperature, type of co-substrate, as well as the inhibitory effects exerted either by excess substrate or product. The final part of the work summarized the downstream processes and the related unit operations involved in the recovery of vanillin from the bioconversion medium.


Assuntos
Oxidação Química , Produção de Alimentos , Propriedade Intelectual , Fenômenos Químicos , Vanilla , Vanilla/microbiologia , Biodegradação Ambiental , Amostras de Alimentos , Métodos , Métodos
16.
Curr Med Chem ; 17(15): 1500-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20166932

RESUMO

The targeting of specific DNA repair mechanisms may be a promising strategy to improve the efficacy of antitumor therapy. The cytotoxic effects of the clinically relevant topoisomerase 1 (Top1) poison camptothecins are related to the generation of DNA lesions and tumor cells may be resistant to DNA damaging agents due to increased repair. Tyrosyl- DNA phosphodiesterase 1 (TDP1) is implicated in the repair of strand breaks by removing abortive Top1/DNA complexes. Thus, a role for TDP1 in counteracting DNA damage induced by camptothecins has been proposed. Here, we review the role of TDP1 in DNA repair with particular reference to TDP1 function, its cooperation with other pathways and the development of pharmacological inhibitors.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/química , Camptotecina/uso terapêutico , Inibidores de Fosfodiesterase/química , Diester Fosfórico Hidrolases/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Dano ao DNA , Reparo do DNA , DNA Topoisomerases Tipo I/metabolismo , Humanos , Doenças do Sistema Nervoso/tratamento farmacológico , Inibidores de Fosfodiesterase/uso terapêutico , Diester Fosfórico Hidrolases/química
17.
Braz J Microbiol ; 41(3): 519-30, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24031526

RESUMO

This review aims at providing an overview on the microbial production of vanillin, a new alternative method for the production of this important flavor of the food industry, which has the potential to become economically competitive in the next future. After a brief description of the applications of vanillin in different industrial sectors and of its physicochemical properties, we described the traditional ways of providing vanillin, specifically extraction and chemical synthesis (mainly oxidation) and compared them with the new biotechnological options, i.e., biotransformations of caffeic acid, veratraldehyde and mainly ferulic acid. In the second part of the review, emphasis has been addressed to the factors most influencing the bioproduction of vanillin, specifically the age of inoculum, pH, temperature, type of co-substrate, as well as the inhibitory effects exerted either by excess substrate or product. The final part of the work summarized the downstream processes and the related unit operations involved in the recovery of vanillin from the bioconversion medium.

18.
Mini Rev Med Chem ; 9(9): 1102-12, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19689406

RESUMO

ATP binding cassette transporters are implicated in multidrug resistant phenotypes of tumor cells and may be cancer stem cell markers. Inhibitors of drug efflux pumps represent an emerging group of potentially useful agents for the improvement of antitumor therapy. Here we provide an overview of drug transporter functions and modulation.


Assuntos
Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Transportadores de Cassetes de Ligação de ATP/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Animais , Humanos
20.
BJOG ; 116(1): 114-8, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19087082

RESUMO

We conducted a prospective study of conservative treatment in 21 young nulliparous women with grade (G)1 endometrial cancer stage IA (11) or atypical complex hyperplasia (10). All were treated with a low-dose cyclic natural progestin therapy (200 mg/day from day 14-25) and encouraged to attempt pregnancy immediately. No adverse therapy-related effects were recorded. Overall response rate to progestin therapy was 57%. Nine women conceived (43%). There were 13 pregnancies, of which 13 were spontaneous and 8 were in women with persistent disease or partial response to hormonal treatment. Three additional complete responses were observed after delivery. Only women with known primary infertility or severe polycystic ovary syndrome showed inadequate pregnancy rate. Fifteen women underwent definitive surgery after enrolment (median 27 months, range 3-56 months). All 21 women are alive and disease free after a median follow up of 98 months.


Assuntos
Carcinoma Endometrioide/tratamento farmacológico , Hiperplasia Endometrial/tratamento farmacológico , Neoplasias do Endométrio/tratamento farmacológico , Fertilidade/efeitos dos fármacos , Complicações Neoplásicas na Gravidez/tratamento farmacológico , Adulto , Antineoplásicos Hormonais/administração & dosagem , Métodos Epidemiológicos , Feminino , Humanos , Gravidez , Progestinas/administração & dosagem , Adulto Jovem
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