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1.
Food Res Int ; 179: 114017, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38342539

RESUMO

This study produced pH-sensing carboxymethyl cellulose (CMC) films functionalized with bioactive compounds obtained by pressurized liquid extraction (PLE) of grape peel to monitor the freshness of pork and milk. A semi-continuous PLE was conducted using hydroethanolic solution (70:30, v/v) at a flow rate of 5 mL/min, 15 MPa, and 60 °C. The films were produced by the casting technique using CMC (2.5 %, w/v), glycerol (1 %, v/v), and functionalized with 10, 30, and 50 % (v/v) grape peel extract. From the results obtained, LC-MS/MS revealed that PLE extracted twenty-seven phenolic compounds. The main phenolic compounds were kaempferol-3-glucoside (367.23 ± 25.88 µg/mL), prunin (270.23 ± 3.62 µg/mL), p-coumaric acid (236.43 ± 26.02 µg/mL), and procyanidin B1 (117.17 ± 7.29 µg/mL). The CMC films presented suitable color and mechanical properties for food packaging applications. The addition of grape peel extract promoted the pH-sensing property, showing the sensitivity of anthocyanins to pH changes. The films functionalized with grape peel extract presented good release control of bioactive compounds, making them suitable for food packaging applications. When applied to monitor the freshness of pork and milk, the films exhibited remarkable color changes associated with the pH of the food during storage. In conclusion, PLE is a sustainable approach to obtaining bioactive compounds from the grape peel, which can be applied in the formulation of pH-sensing films as a promising sustainable material to monitor food freshness during storage.


Assuntos
Carne de Porco , Carne Vermelha , Vitis , Animais , Suínos , Carboximetilcelulose Sódica/química , Carne Vermelha/análise , Leite , Antocianinas/química , Cromatografia Líquida , Concentração de Íons de Hidrogênio , Espectrometria de Massas em Tandem , Fenóis
2.
Int J Pharm ; 640: 123011, 2023 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-37146952

RESUMO

Melanoma is the most aggressive form of skin cancer, with increasing incidence and mortality rates. To overcome current treatment limitations, a hybrid molecule (HM) combining a triazene and a sulfur L-tyrosine analogue, was recently synthesized, incorporated in long blood circulating liposomes (LIP HM) and validated in an immunocompetent melanoma model. The present work constitutes a step forward in the therapeutic assessment of HM formulations. Here, human melanoma cells, A375 and MNT-1, were used and dacarbazine (DTIC), a triazene drug clinically available as first-line treatment for melanoma, constituted the positive control. In cell cycle analysis, A375 cells, after 24-h incubation with HM (60 µM) and DTIC (70 µM), resulted in a 1.2 fold increase (related to control) in the percentage of cells in G0/G1 phase. The therapeutic activity was evaluated in a human murine melanoma model (subcutaneously injected with A375 cells) to most closely resemble the human pathology. Animals treated with LIP HM exhibited the highest antimelanoma effect resulting in a 6-, 5- and 4-fold reduction on tumor volume compared to negative control, Free HM and DTIC groups, respectively. No toxic side effects were detected. Overall, these results constitute another step forward in the validation of the antimelanoma activity of LIP HM, using a murine model that more accurately simulates the pathology that occurs in human patients.


Assuntos
Melanoma , Neoplasias Cutâneas , Humanos , Animais , Camundongos , Nanomedicina , Melanoma/metabolismo , Dacarbazina , Neoplasias Cutâneas/patologia , Linhagem Celular Tumoral , Apoptose
3.
Biomed Pharmacother ; 157: 114021, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36399831

RESUMO

The aggressiveness of melanoma and lack of effective therapies incite the discovery of novel strategies. Recently, a new dual acting hybrid molecule (HM), combining a triazene and a ʟ-tyrosine analogue, was synthesized. HM was designed to specifically be activated by tyrosinase, the enzyme involved in melanin biosynthesis and overexpressed in melanoma. HM displayed remarkable superior antiproliferative activity towards various cancer cell lines compared with temozolomide (TMZ), a triazene drug in clinical use, that acts through DNA alkylation. In B16-F10 cells, HM induced a cell cycle arrest at phase G0/G1 with a 2.8-fold decrease in cell proliferation index. Also, compared to control cells, HM led to a concentration-dependent reduction in tyrosinase activity and increase in caspase 3/7 activity. To maximize the therapeutic performance of HM in vivo, its incorporation in long blood circulating liposomes, containing poly(ethylene glycol) (PEG) at their surface, was performed for passively targeting tumour sites. HM liposomes (LIP HM) exhibited high stability in biological fluids. Preclinical studies demonstrated its safety for systemic administration and in a subcutaneous murine melanoma model, significantly reduced tumour progression. In a metastatic murine melanoma model, a superior antitumour effect was also observed for mice receiving LIP HM, with markedly reduction of lung metastases compared to positive control group (TMZ). Biodistribution studies using 111In-labelled LIP HM demonstrated its ability for passively targeting tumour sites, thus correlating with the high therapeutic effect observed in the two experimental murine melanoma models. Overall, our proposed nanotherapeutic strategy was validated as an effective and safe alternative against melanoma.


Assuntos
Lipossomos , Melanoma Experimental , Camundongos , Animais , Lipossomos/farmacologia , Distribuição Tecidual , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/patologia , Temozolomida , Proliferação de Células , Linhagem Celular Tumoral
4.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 44(3): 264-270, May-June 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1374604

RESUMO

Objective: Adapt and validate the Mood Rhythm Instrument (MRhI), a self-reported questionnaire that assesses self-perceived rhythmicity of mood-related symptoms in adults, into a version that assesses and evaluates perceived mood-related symptoms in adolescents (MRhI-Y). Methods: Adaptation of the Brazilian Portuguese version of the MRhI for an adolescent population followed three steps: review by consultants, analysis by experts, and pilot testing through a visual analogue scale (VAS). The final questionnaire (MRhI-Y) was applied to 171 adolescents aged 12-17 years. Internal consistency was calculated using Cronbach's alpha and McDonald's omega. The psychometric properties of the MRhI-Y were evaluated using exploratory factor analysis (EFA). Results: The MRhI-Y was designed to use wording more appropriate for adolescents than that of the MRhI. Expert agreement about item quality ranged between 82 and 100%. Adolescents' VAS ratings indicated good comprehension of the items. Cronbach's alpha and McDonalds' omega coefficients were 0.71 and 0.74. The EFA resulted in a three-factor solution (affective, cognitive, and somatic). Younger adolescents (ages 12 to 13) reported lower rhythmicity scores than older groups (ages 14 to 15 and 16 to 17), even controlling for chronotype. Conclusions: The Brazilian Portuguese version of the MRhI-Y presented adequate comprehension by adolescents and good internal consistency. The MRhI-Y is a promising tool to improve our understanding of the underlying characteristics of mood fluctuation in adolescence.

5.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 44(2): 136-146, Apr. 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1374581

RESUMO

Objective: To assess the adherence to a set of evidence-based recommendations to support mental health during the coronavirus disease 2019 (COVID-19) pandemic and its association with depressive and anxiety symptoms. Methods: A team of health workers and researchers prepared the recommendations, formatted into three volumes (1: COVID-19 prevention; 2: Healthy habits; 3: Biological clock and sleep). Participants were randomized to receive only Volume 1 (control), Volumes 1 and 2, Volumes 1 and 3, or all volumes. We used a convenience sample of Portuguese-speaking participants over age 18 years. An online survey consisting of sociodemographic and behavioral questionnaires and mental health instruments (Patient Health Questionnaire-9 [PHQ-9] and Generalized Anxiety Disorder-7 [GAD-7]) was administered. At 14 and 28 days later, participants were invited to complete follow-up surveys, which also included questions regarding adherence to the recommendations. A total of 409 participants completed the study - mostly young adult women holding university degrees. Results: The set of recommendations contained in Volumes 2 and 3 was effective in protecting mental health, as suggested by significant associations of adherence with PHQ-9 and GAD-7 scores (reflecting anxiety and depression symptoms, respectively). Conclusion: The recommendations developed in this study could be useful to prevent negative mental health effects in the context of the pandemic and beyond.

6.
ACS Med Chem Lett ; 12(11): 1669-1677, 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34795855

RESUMO

Malignant melanoma is the major cause of death from skin cancer. Treatment of metastatic melanoma remains an enormous challenge. In this study we developed hybrid compounds and studied their potential use in malignant melanoma chemotherapy. They were designed to act by a double mechanism of action, being composed of two pharmacophores: the tyrosine sulfur analogue 4-S-cysteaminylphenol (4-S-CAP, 10), with immunomodulatory properties and specific melanocytotoxic activity, and triazene 4, with DNA alkylating properties. The design of these compounds aims to achieve selective activation by the enzyme tyrosinase overexpressed in melanoma cells. Compounds 11a-e, 13a, and 13b were found to be excellent tyrosinase substrates (0.5 min ≤ t 1/2 ≤ 3.7 min). Furthermore, derivatives 11 and 13 were evaluated for their molecular properties, hepatotoxicity, in vivo toxicity profile, and assessment of cytotoxic activity in melanoma and non-melanoma cell lines. The results were compared with those obtained for temozolomide, a triazene used in melanoma therapy. It was discovered that the hybrids are selective and effective drugs, representing a valuable model for the development of new multitarget melanoma therapy. In particular, compound 10 may be an important component for these strategies that use a metabolic pathway of melanin synthesis. Molecular hybridization of 10 with triazenes 4 renders the hybrids (11 and 13) unexpectedly devoid of hepatotoxicity while maintaining cytotoxic activity in malignant cells.

7.
Bioorg Med Chem ; 25(15): 3900-3910, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28602669

RESUMO

Metastatic melanoma still remains one the most difficult cancers to overcome. The aim of our research was the design of anti-tumour triazene compounds 3 for application to a melanoma-specific therapy. The strategy exploits the unique enzyme pathway of melanin biosynthesis for conversion of non-toxic prodrugs into toxic drugs in the melanoma cell. The compounds 3 were designed by coupling two active moieties, the alkylating triazenes and different tyrosinase substrates. All compounds 3 revealed to be chemically stable in isotonic phosphate buffer (PBS) at physiologic pH (t½≥48h), and most of them showed to be slowly hydrolysed in human plasma (1.5≤t½ (h)≤161). Compounds 3c-n revealed to be excellent tyrosinase substrates (0.74≤t½ (min)≤6) with the best tyrosinase substrate 3l releasing MMT 45s after tyrosinase activation. Structure-activity relationship studies allowed the identification of the better structural features for enzyme affinity. Furthermore, the derivatives 3l and 3m showed cell selectivity with significant cytotoxic effects (IC50 values of 46-65µM) against melanoma cell lines with tyrosinase overexpression MNT-1 and B16F10.


Assuntos
Antineoplásicos/farmacologia , Melanoma/patologia , Triazenos/farmacologia , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Dimerização , Ensaios de Seleção de Medicamentos Antitumorais , Meia-Vida , Humanos , Camundongos , Triazenos/química
8.
Curr Med Chem ; 24(42): 4873-4904, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27573064

RESUMO

Nucleic acids are prone to structural polymorphism and a number of structures may be formed in addition to the well-known DNA double helix. Among these is a family of nucleic acid four-stranded structures known as G-quadruplexes (G4). These quadruplex structures can be formed by sequences containing repetitive guanine-rich tracks and the analysis of Non-B-DNA database indicated an enrichment of these sequences in genomic regions controlling cellular proliferation, such as for example in the promoter regions of c- MYC, k-RAS, c-KIT, HSP90 and VEGF among others. The broad concept of G4 targeting with small molecules is now generally accepted as a promising novel approach to anticancer therapy and several small molecules with antiproliferative activity in cancer cell lines have also been shown to stabilize these DNA structures, thus suggesting a potential application of G4-interactive small molecules as new anticancer drugs. Herein we review, by targeted oncogene and main chemical scaffold, those G4-interactive small molecules with reported gene expression modulatory activity in cancer cell lines. The data obtained so far are encouraging but further efforts are needed to validate G4 as drug targets and optimize the structure of G4- interactive small molecules into new anticancer drugs.


Assuntos
Antineoplásicos/farmacologia , DNA de Neoplasias/efeitos dos fármacos , Quadruplex G/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Bibliotecas de Moléculas Pequenas/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , DNA de Neoplasias/genética , Humanos , Bibliotecas de Moléculas Pequenas/química
9.
São Paulo; s.n; 2017. 133 p.
Tese em Português | LILACS | ID: biblio-875665

RESUMO

Introdução: Dioxinas, furanos e bifenilas policloradas são poluentes tóxicos para a saúde humana incluindo riscos de incidência de cânceres, efeitos de neurodesenvolvimento, lesões dérmicas, cloroacne. Estes compostos são poluentes orgânicos persistentes (POPs) que podem ser transportados de longas distâncias da fonte de emissão e se bioacumular em ecossistemas. A atmosfera poluída foi recentemente classificada como carcinogênica para os seres humanos pela Organização Mundial da Saúde, mostrando a importância de sua caracterização, principalmente para compostos tóxicos. Entretanto, técnica de coleta ativa tem custo elevado para POPs, e existem poucos estudos de calibração que validem a substituição. Objetivos: Avaliar a toxicidade equivalente da atmosfera por dioxinas, furanos e bifenilas cloradas, utilizando técnicas de coleta ativa e passiva, e verificar gradiente de concentração nos ambientes urbano, urbano/industrial e de background. Método: Amostras de ar foram coletadas, utilizando coletores ativos e passivos, durante dois períodos consecutivos de quatro meses: de setembro a dezembro de 2014 (período 1) e de maio a agosto de 2015 (período 2) em três cidades de São Paulo, SP, em ambientes urbano, urbano/industrial e de background. Todas as amostras foram extraídas com solução de tolueno:acetona (9:1) em Soxhlet por 24 h e padrões marcados (13C12-PCDD/Fs e 13C12-PCBs) foram adicionados em cada amostra antes do processo de extração. Os extratos foram purificados em coluna de sílica mista (40 por cento H2SO4 e 10 por cento AgNO3) seguida por coluna de alumina. O procedimento analítico foi realizado utilizando HRGC/HRMS (High Resolution Gas Chromatograph/High Resolution Mass Spectrometer) operando em ionização de impacto de elétrons com energia de 35 eV no modo SIM (Select Ion Monitoring) e resolução de 10.000. Resultados mostraram que: (1) existe variação sazonal para concentrações de PCDD/Fs no ar entre os períodos 1 e 2 (p=0,03), enquanto as concentrações de dl-PCBs não foram estatisticamente diferentes nestes períodos (p=0,52); (2) existe gradiente de concentração de PCDD/Fs e dl- PCBs que aumenta na seguinte ordem: background


Introduction: Dioxins, furans and polychlorinated biphenyls are toxic pollutants for human health including risks of cancer incidence, neurodevelopmental effects, dermal lesions, chloracne. These compounds are persistent organic pollutants (POPs) that can be transported to long distances from the emission source and they are bioaccumulated in ecosystems. Recently, the outdoor air pollution were classified as carcinogenic to humans by the World Health Organization, showing the importance of its characterization for toxic compounds. However, active air monitoring has a high cost for POPs, and there is a few calibration studies which support that substitution. Objective: To assess the equivalent toxicity of the atmosphere regarding the measurement of dioxins, furans and polychlorinated biphenyls, using active and passive air samplers, and to evatuate the contrasting concentrations at urban, urban/industrial and background sites. Method: Air samples were collected, using active and passive samplers, over two consecutive periods of four months: from September to December 2014 (period 1) and from May to August 2015 (period 2) at three cities in São Paulo, SP, covering urban, urban/industrial and background sites. All samples were extracted with toluene:acetone (9:1) in a Soxhlet apparatus for 24 hours and surrogate standards (13C12-PCDD/F and 13C12-PCBs) were spiked on each sample media prior to extraction procedure. The extracts were purified on an silica column (40 per cent H2SO4 and 10 per cent AgNO3) followed by an alumina column. The analytical procedure was carried out using HRGC/HRMS (High Resolution Gas Chromatograph/High Resolution Mass Spectrometer) operating in electron impact ionization with an energy of 35 eV in SIM (selected ion monitoring) mode and 10.000 resolution power. Results show that (1) there are seasonal variations for PCDD/F concentrations in air between period 1 and 2 (p=0.03), whereas dl-PCB levels were not statistically different (p=0.52) in those periods. (2) PCDD/F and dl-PCB air levels are in the following order: background


Assuntos
Poluição do Ar , Coleta de Dados/métodos , Dioxinas/toxicidade , Furanos/toxicidade , Bifenilos Policlorados , Vazamento de Gases , Zonas Industriais , Compostos Orgânicos/toxicidade , Área Urbana
10.
Clin. biomed. res ; 37(1): 41-47, 2017. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-833290

RESUMO

Introduction: The Mood Rhythm Instrument (MRI) is a questionnaire developed to assess the circadian rhythm of mood-related behaviors. The aim of this study was to translate this instrument from Brazilian Portuguese into Spanish. Methods: The translation process consisted of forward translation, adjustment, back translation, back translation review and harmonization. Results: Comparing the initial Spanish translation and the final Spanish version, there were no semantic differences and the items were not changed. Conclusions: The Spanish version of the MRI is ready to be tested in a Spanish population. In the future, assessing and comparing mood-related behaviors in transcultural studies will be possible(AU)


Assuntos
Humanos , Ritmo Circadiano , Transtornos do Humor/diagnóstico , Inquéritos e Questionários , Tradução , Relógios Biológicos , Transtornos do Humor/fisiopatologia , Psicometria , Autorrelato
11.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 38(2): 148-153, Apr.-June 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-784305

RESUMO

Objective: To describe the initial steps in the development and validation of a new self-reported instrument designed to assess daily rhythms of mood symptoms, namely, the Mood Rhythm Instrument. Methods: A multidisciplinary group of experts took part in systematic meetings to plan the construction of the instrument. Clarity of items, their relevance to evaluation of mood states, and the consistency of findings in relation to the available evidence on the biological basis of mood disorders were investigated. The internal consistency of the questionnaire was evaluated through Cronbach’s alpha. Results: All of the items proposed in a first version were well rated in terms of clarity. The items more frequently rated as “rhythmic” were related to the somatic symptoms of mood. Their peaks in 24 hours were more frequent in the morning. The items associated with affective symptoms of mood were rated as less rhythmic, and their peak in 24 hours occurred more frequently in the afternoon and evening. Males and females behaved more similarly with respect to somatic than behavioral-affective items. The second version of the Mood Rhythm Instrument had a Cronbach’s alpha of 0.73. Conclusion: The proposed Mood Rhythm Instrument may be able to detect individual rhythms of cognitive and behavioral measures associated with mood states. Validation in larger samples and against objective measures of rhythms, such as actigraphy, is warranted.


Assuntos
Humanos , Masculino , Feminino , Adulto , Adulto Jovem , Periodicidade , Inquéritos e Questionários , Transtornos do Humor/fisiopatologia , Afeto/fisiologia , Autorrelato , Transtornos do Humor/diagnóstico , Consenso , Autoavaliação Diagnóstica , Pessoa de Meia-Idade
12.
PLoS One ; 10(5): e0126891, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26024321

RESUMO

BACKGROUND: A guanine-rich strand within the promoter of the KRAS gene can fold into an intra-molecular G-quadruplex structure (G4), which has an important role in the regulation of KRAS transcription. We have previously identified indolo[3,2-b]quinolines with a 7-carboxylate group and three alkylamine side chains (IQ3A) as effective G4 stabilizers and promising selective anticancer leads. Herein we investigated the anticancer mechanism of action of these compounds, which we hypothesized due to stabilization of the G4 sequence in the KRAS promoter and subsequent down-regulation of gene expression. METHODOLOGY/PRINCIPAL FINDINGS: IQ3A compounds showed greater stabilization of G4 compared to duplex DNA structures and reduced KRAS promoter activity in a dual luciferase reporter assay. Moreover, IQ3A compounds showed high anti-proliferative activity in HCT116 and SW620 colon cancer cells (IC50 < 2.69 µM), without eliciting cell death in non-malignant HEK293T human embryonic kidney, and human colon fibroblasts CCD18co. IQ3A compounds significantly reduced KRAS mRNA and protein steady-state levels at IC50 concentrations, and increased p53 protein steady-state levels and cell death by apoptosis in HCT116 cells (mut KRAS, wt p53). Furthermore, KRAS silencing in HCT116 p53 wild-type (p53(+/+)) and null (p53(-/-)) isogenic cell lines induced a higher level of cell death, and a higher IQ3A-induced cell death in HCT116 p53(+/+) compared to HCT116 p53(-/-). CONCLUSIONS: Herein we provide evidence that G4 ligands such as IQ3A compounds can target G4 motifs present in KRAS promoter, down-regulate the expression of the mutant KRAS gene through inhibition of transcription and translation, and induce cell death by apoptosis in colon cancer cell lines. Thus, targeting KRAS at the genomic level with G4 ligands may be a new anticancer therapy strategy for colon cancer.


Assuntos
Neoplasias do Colo/tratamento farmacológico , Quadruplex G/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Quinolinas/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/genética , Genes ras , Células HCT116 , Células HEK293 , Humanos , Regiões Promotoras Genéticas , Quinolinas/química
13.
Eur J Med Chem ; 70: 1-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24125877

RESUMO

In this research work we report the synthesis of a new series of triazene prodrugs designed for Melanocyte-Directed Enzyme Prodrug Therapy (MDEPT). These compounds are derived from the N-acyltyrosine amino acid - a good enzyme substrate for the tyrosinase enzyme, which is significantly overexpressed in melanoma cells. We analysed their chemical stability and plasma enzymatic hydrolysis, and we also evaluated the release of the antitumoral drug in the presence of the tyrosinase. Subsequently, we performed the evaluation of the prodrug cytotoxicity in melanoma cell lines with different levels of tyrosinase activity. Prodrug 5c showed the highest cytotoxicity against melanoma cell lines, and this effect correlated well with the tyrosinase activity suggesting that prodrug cytotoxicity is tyrosinase-dependent.


Assuntos
Aminoácidos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Monofenol Mono-Oxigenase/metabolismo , Pró-Fármacos/metabolismo , Triazenos/química , Triazenos/síntese química , Triazenos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Melanoma/enzimologia , Estrutura Molecular , Pró-Fármacos/síntese química , Pró-Fármacos/química , Pró-Fármacos/farmacologia , Relação Estrutura-Atividade , Triazenos/metabolismo
14.
ChemMedChem ; 8(11): 1751-65, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23956078

RESUMO

Malignant metastatic melanoma is one of the oncologic diseases with the worst clinical prognosis, due primarily to resistance phenomena against chemotherapeutic agents in current use. However, over the last few years, characterization of the molecular mechanisms involved in the development and progression of the disease has contributed to elucidation of the main pathways by which tissue invasion and metastasis can occur. More importantly, the identification of abnormalities in signaling cascades in melanoma cells has facilitated new therapeutic approaches against malignant melanoma through the design of highly potent and selective drugs with low associated toxicity. Ultimately, recognition of the restricted applicability of new chemotherapies in certain genetic contexts has led to significant improvements in the results of clinical trials, anticipating the existing need for investment in personalized therapies, and taking into account the molecular alterations observed in tumors. Although significant advances have been made in terms of extending the median overall survival rate and improving the quality of life for patients, the mechanisms that compromise in vivo drug efficacy remain poorly understood, particularly those concerning therapeutic resistance phenomena. This review summarizes recently validated targets from the perspective of the medicinal chemistry carried out in the design of the most promising structures.


Assuntos
Antineoplásicos/uso terapêutico , Sistemas de Liberação de Medicamentos , Melanoma/tratamento farmacológico , Química Farmacêutica/tendências , Sistemas de Liberação de Medicamentos/tendências , Humanos , Melanoma/fisiopatologia , Estrutura Molecular , Segunda Neoplasia Primária , Transdução de Sinais
15.
São Paulo; s.n; 2012. 208 p. tab, ilus, graf.
Tese em Português | LILACS | ID: lil-713104

RESUMO

Objetivo: Avaliar a influência da atividade canavieira nas concentrações de ozônio troposférico em área urbana de Araraquara, SP. Método: Foram realizadas coletas passiva de ozônio e COV (Compostos Orgânicos Voláteis), na safra e entressafra de cana-de-açúcar 2011 2012, em 6 locais na área urbana, com exposição de 5 dias. Coleta ativa de COV foi realizada na área central durante 6 dias, não consecutivos, utilizando 24 coletores por dia com exposição de 1 hora cada um, totalizando 144 amostras. Coletas passivas de COV também foram realizadas em 3 situações: durante e após a queima de canavial e em área urbana, durante 1 hora cada, totalizando 9 amostras. A quali e quantificação dos COV foram realizadas por cromatografia gasosa, utilizando como pré-tratamento da amostra dessorvedor térmico e criogenia. A determinação de ozônio foi feita por cromatografia iônica com a quantificação de íons nitrato, produto da reação do ozônio com o absorvente químico. Além disso, foi realizada estimativa de emissões atmosféricas da atividade canavieira e urbanas para avaliar a participação dessas fontes de poluição na emissão de precursores de ozônio. Resultados: Concentrações médias de ozônio estiveram na faixa de 42,50±7,48 a 66,62±10,07 µg m-3, com média de 52,93±12,39 µg m-3, durante a safra de cana, e de 26,51±2,53 a 77,78±11,04 µg m-3, com média de 52,61±25,65 µg m-3, na entressafra. Os 11 COV identificados na atmosfera urbana de Araraquara estão associados à combustão de veículos automotores, com exceção do d-limoneno. Tolueno e d-limoneno foram os COV mais abundantes atingindo concentrações de 0,40 e 0,50 ppb, respectivamente. Detectaram-se diversos COV nas amostras coletadas nos canaviais durante a queima, destacando-se: eteno (51,59 por cento ), etano (11,14 por cento ), propeno (10,64 por cento ), butano (4,97 por cento ), tolueno (3,39 por cento ) e propano (2,21 por cento ). O eteno foi utilizado para caracterizar a emissão da queima de cana, sendo encontrado na atmosfera urbana na proporção de 13,31 por cento . Estimativa de emissão da agroindústria canavieira mostrou que a queima da palha contribuiu com cerca de 44 por cento de HCNM (Hidrocarbonetos Não-Metânicos) e os veículos pesados, a queima do bagaço e da palha corresponderam a 27 por cento da emissão de NOx (óxidos de nitrogênio). As emissões da frota veicular de Araraquara em 2011 contribuíram com 52,85 por cento e 65,55 por cento , respectivamente, para emissões de HCNM e NOx.


Assuntos
Poluentes Atmosféricos , Ozônio/análise , Saccharum , Atmosfera , Poluição do Ar , Brasil , Produtos Agrícolas , Compostos Orgânicos Voláteis/análise , Área Urbana
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