Repositório Institucional - Unifesp :: Navegando por Palavras-chave "Fluorescence"

Navegando por Palavras-chave "Fluorescence"

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Acridone alkaloids from swinglea glutinosa (rutaceae) and their effects on photosynthesis
(Wiley-v c h verlag gmbh, 2016) Arato Ferreira, Pedro H. [UNIFESP]; dos Santos, Djalma A. P.; da Silva, Maria Fatima das G. F.; Vieira, Paulo C.; King-Diaz, Beatriz; Lotina-Hennsen, Blas; Veiga, Thiago A. M. [UNIFESP]
Continuing our search for herbicide models based on natural products, we investigated the action mechanisms of five alkaloids isolated from Swinglea glutinosa (Rutaceae): Citrusinine-I (1), glycocitrine-IV (2), 1,3,5-trihydroxy-10-methyl-2,8-bis(3-methylbut-2-en-1-yl)-9(10H)-acridinone (3), (2R)-2-tert-butyl-3,10-dihydro-4,9-dihydroxy-11-methoxy-10-methylfuro[3,2-b]acridin-5(2H)-one (4), and (3R)-2,3,4,7-tetrahydro-3,5,8-trihydroxy-6-methoxy-2,2,7-trimethyl-12H-pyrano[2,3-a]acridin-12-one (5) on several photosynthetic activities in an attempt to find new compounds that affect photosynthesis. Through polarographic techniques, the compounds inhibited the non-cyclic electron transport in the basal, phosphorylating, and uncoupled conditions from H2O to methylviologen (=MV). Therefore, they act as Hill reaction inhibitors. This approach still suggested that the compounds 4 and 5 had their interaction site located at photosystem I. Studies on fluorescence of chlorophyll a suggested that acridones (1-3) have different modes of interaction and inhibition sites on the photosystem II electron transport chain.
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Application of Fluorescence to the Study of Crude Petroleum
(Springer, 2011-05-01) Steffens, Juliana; Landulfo, Eduardo; Courrol, Lilia Coronato [UNIFESP]; Guardani, Roberto; Universidade de São Paulo (USP); Nucl & Energet Res Inst; Universidade Federal de São Paulo (UNIFESP)
Crude petroleum oils are complex mixtures of different compounds (mainly organic), which are obtained from an extensive range of different geological sources. the fluorescence of crude petroleum oils derives largely from the aromatic hydrocarbon fraction, and this fluorescence emission is strongly influenced by the chemical composition (e.g., fluorophore and quencher concentrations) and physical characteristics (e.g., viscosity and optical density) of the oil. the fluorescence spectroscopy (FS) is increasingly used in petroleum technology due the availability of better optical detection techniques, because FS offers high sensitivity, good diagnostic potential, and relatively simple instrumentation. in this work we analyzed crude petroleum at different dilution in Nujol, a transparent mineral oil. the main objective of this work was to verify the possibility to measure crude oil emission spectroscopic without use of volatile solvents. the mixtures of nujol with different -crude oil concentrations were measured with a 10 mm optical path cuvette thus simplifying the fluorescence spectroscopy signal detection. the emission spectra were obtained by exciting the samples with a 400 W Xenon lamp at 350 nm, 450 nm and 532 nm. the emissions of the samples were collected perpendicularly with the excitation axis.
Acesso aberto (Open Access)
Avaliação da eficácia do uso do Verde Indocianina associada à fluorescência na biópsia do linfonodo sentinela
(Universidade Federal de São Paulo, 2023-04-26) Sá, Rafael da Silva [UNIFESP]; Nazário, Afonso Celso Pinto [UNIFESP]; http://lattes.cnpq.br/0266384667983727; http://lattes.cnpq.br/4680174809264272
Introdução: A biópsia do linfonodo sentinela é a técnica consagrada no estadiamento axilar das pacientes portadoras de câncer de mama inicial sem comprometimento clínico axilar. Embora já seja uma técnica amplamente difundida, seu histórico é relativamente recente. Três técnicas são muito utilizadas globalmente para deteção do linfonodo sentinela: o azul patente; o radiofármaco tecnécio 99 com uso do gamma probe; e a combinação dessas duas técnicas. Objetivos: Avaliar a taxa de detecção do linfonodo sentinela com uma técnica inovadora: o verde de indocianina associado à fluorescência em pacientes com câncer de mama, sua comparação com os demais métodos (azul patente e braço combinado azul patente + verde indocianina) e os custos destes procedimentos. Métodos: Foram avaliadas 99 pacientes com idade média de 58,4 ± 13,3 anos subdivididas em três braços com 33 pacientes, sendo que em um braço foi submetido à técnica do linfonodo sentinela utilizando azul patente, em outro o verde indocianina e no terceiro a combinação dos dois corantes. A verde indocianina, marcador fluorescente que consiste na iluminação do linfonodo sentinela no comprimento de onda de excitação (750 a 800 nm), foi aplicado na dose de 5mg na região periareolar, sendo visualizado através do aparelho image1S® acoplado à fonte de luz D-light P® e câmera de laparoscopia. Pesquisa realizada no Hospital de Esperança de Presidente Prudente - SP em parceira com a Disciplina de Mastologia da Escola Paulista de Medicina da Universidade Federal de São Paulo no período de 02/08/2019 e 16/12/2021. Resultados: Os principais subtipos histológico e imunohistoquímico foram o carcinoma invasivo do tipo não especial em 92,9% e luminal em 84,9% dos casos, respectivamente. A taxa de acurácia na identificação do linfonodo sentinela foi de 78,8% com a utilização do azul patente, 93,9% com o verde indocianina e 100% com o azul patente + verde indocianina. O grupo combinado identificou principalmente dois linfonodos sentinelas (48,5%), entretanto os demais grupos identificaram mais comumente um linfonodo sentinela apenas. O tempo médio de identificação do linfonodo sentinela foi de 20,6 minutos entre as pacientes submetidas ao corante tradicional, 8,6 minutos no braço do verde indocianina e 10 minutos na associação dos dois métodos (P<0,001). O tempo cirúrgico médio foi de 69,4 minutos com o azul patente, 55,1 minutos com o verde indocianina e 69,4 minutos no combinado (P<0,001). O custo total da internação hospitalar nas pacientes que foram submetidas ao verde indocianina foi menor que as do azul patente (P=0,026) e que as do braço combinado (P=0,007). Conclusões: A taxa de detecção do linfonodo sentinela através da fluorescência com o uso do verde indocianina foi considerada eficaz. A comparação da taxa de detecção do linfonodo sentinela entre o uso do azul patente, verde indocianina e azul patente + verde indocianina (combinado) revelou diferenças estatisticamente significantes, sendo o método combinado o mais eficaz. O maior custo do corante verde indocianina não impactou na elevação do custo geral da internação hospitalar.
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Biocontrol of Fusarium species by a novel lectin with low ecotoxicity isolated from Sebastiania jacobinensis
(Elsevier B.V., 2010-04-15) Vaz, Antonio F. M.; Costa, Romero M. P. B.; Melo, Ana M. M. A.; Oliva, Maria L. V. [UNIFESP]; Santana, Lucimeire A. [UNIFESP]; Silva-Lucca, Rosemeire A. [UNIFESP]; Coelho, Luana C. B. B.; Correia, Maria T. S.; Universidade Federal de Pernambuco (UFPE); Universidade Federal de São Paulo (UNIFESP); State Univ Western Parana
A lectin from Sebastiania jacobinensis bark was isolated using a combination of acetone precipitation, ammonium sulphate fractionation, ion exchange and gel filtration chromatographies. the lectin purified, with a molecular mass of 52.0 kDa and composed of two subunits of 24 kDa, is a glycoprotein with a neutral carbohydrate content of 6.94%. the lectin shows maximum activity over the pH range 4.0-7.5 and heat stability up to 70 degrees C. Our results show that the lectin is an incompetitive inhibitor for trypsin, with a Ki of 0.39 +/- 0.02 mu M. Fluorescence spectroscopy indicated the existence of a hydrophobic surface. the percentages of secondary structure are 75% alpha-helix, 10% beta-sheet, 5% beta-turn and 10% unordered. Lectin inhibits the mycelial growth of Fusarium moniliforme and Fusarium oxysporum with an IC(50) value of 123 +/- 0.5 and 303 +/- 0.9 mu g, respectively. Artemia salina Leach and embryos of Biomphalaria glabrata are not affected by the lectin, indicating low environmental toxicity. Alternative viewpoints are presented that might hopefully help in future efforts to develop safer and more effective microbial control agents. (C) 2009 Elsevier B.V. All rights reserved.
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Bioinspired water-soluble two-photon fluorophores
(Elsevier Sci Ltd, 2018) Rodrigues, Ana Clara Beltran; Mariz, Ines de Fatima Afonso; Macoas, Ermelinda Maria Sengo; Tonelli, Renata Rosito [UNIFESP]; Martinho, Jose Manuel Gaspar; Quina, Frank Herbert; Bastos, Erick Leite
The structural modification of plant pigments allows the development of new functional dyes with tailored photophysical properties. Two-photon excitation fluorescence microscopy has emerged as an important technique, but requires the use of fluorophores having large two-photon absorption cross-sections in water. This feature is rarely found in natural or artificial dyes, but betalains, the main pigments of beetroots and some species of fluorescent flowers, can be modified to produce water-soluble two-photon fluorophores. Herein we describe the semisynthesis and photophysical characterization of two water-soluble artificial coumarinic betalains. The excitation of these compounds in the near-infrared results in yellow fluorescence with two-photon cross-sections in water of 323 GM and 179 GM.
Acesso aberto (Open Access)
Comparative EPR and fluorescence conformational studies of fully active spin-labeled melanotropic peptides
(Elsevier B.V., 2001-05-25) Nakaie, Clovis Ryuichi [UNIFESP]; Barbosa, Simone Reis [UNIFESP]; Vieira, Renata de Freitas Fischer [UNIFESP]; Fernandez, Roberto Morato; Cilli, Eduardo Maffud [UNIFESP]; Castrucci, Ana Maria de Lauro; Visconti, Maria Aparecida; Ito, Amando Siuiti; Lamy, Maria Teresa; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
Similar to melanocyte stimulating hormone (alpha -MSH), its potent and long-acting analogue, [Nle(4), D-Phe(7)]alpha -MSH, when labeled with the paramagnetic amino acid probe 2,2,6,6-tetramethylpiperidine-N-oxyl-4-amino-4-carboxylic acid (Toac), maintains its full biological potency, thus validating any comparative structural investigations between the two labeled peptides, Correlation times, calculated from tire electron paramagnetic resonance signal of Toac bound to the peptides, and Toac-Trp distances, estimated from the Toac fluorescence quenching of the Trp residue present in the peptides, indicate a more rigid and folded structure for the potent analogue as compared to the hormone, in aqueous medium. (C) 2001 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.
Acesso aberto (Open Access)
Comparative spectroscopic studies between conventional and organic soybean oils
(IEEE, 2021-07-05) Lopes, Carla Regina Boorges [UNIFESP]; Courrol, Lilia Coronato [UNIFESP]; Silva, Heron Dominguez Torres [UNIFESP]; http://lattes.cnpq.br/2967116316160694
A healthy lifestyle based on an organic diet appears to be a growing trend among young adults. Organic soybean oils are an alternative to conventional oils, but they can be the subject of fraud that worries consumers, traders, and producers. The results obtained indicate that the combination of steady-state fluorescence techniques, considering mainly the characteristics of the spectra obtained with excitation at 320, 340 and 460 nm and time-resolved fluorescence with excitation around 403 nm, demonstrates the potential to differentiate oils conventional from organic soybeans oils.
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Correlation Between Autofluorescence Intensity and Tumor Area in Mice Bearing Renal Cell Carcinoma
(Springer, 2008-11-01) Bellini, Maria Helena [UNIFESP]; Coutinho, Enia Lucia [UNIFESP]; Courrol, Lilia Coronato [UNIFESP]; Silva, Flávia Rodrigues de Oliveira [UNIFESP]; Vieira, Nilson Dias; Schor, Nestor [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); IPEN CNEN SP; Universidade de São Paulo (USP)
Protoporphyrin IX (PpIX) is a porphyrin derivative that is accumulated in cancerous tissue in consequence of the tumor-specific metabolic alterations. the aim of this study was to evaluate the accumulation of PpIX in mice bearing renal cell carcinoma by spectroscopy analysis. A total of 24 male Balb/c mice, 6 weeks old, were divided into six groups: Normal (without inoculation of tumor cells) and 4, 8, 13, 16, and 20 days after inoculation of tumor cells. the orthotopic tumor model of renal cancer was used. Murine renal cell carcinoma (Renca cells) were inoculated into the subcapsular space of the kidney. Normal and tumor-bearing kidneys in different progression stages were removed and analyzed by ex-vivo spectroscopy and by microscopy, for tumor histometric analysis. Emission spectra were obtained by exciting the samples at 405 nm. Significant differences between normal and tumor-bearing kidneys in autofluorescence shape occurred in the 600-700 nm spectral region. A good correlation was found between emission band intensity at 635 nm and the tumor area.
Acesso aberto (Open Access)
Desenvolvimento e resultados preliminares de um sistema cromático de iluminação para oftalmoscópios indiretos
(Conselho Brasileiro de Oftalmologia, 2009-04-01) Oliveira, Thiago Bellini; Trevelin, Luis Carlos; Araujo-Moreira, Fernando Manuel; Bagnato, Vanderlei Salvador; Schor, Paulo [UNIFESP]; Carvalho, Luis Alberto Vieira de [UNIFESP]; Universidade Federal de São Carlos Programa de Pós-graduação em Biotecnologia; Computing Lab da UniKent; UFSCAR Departamento de Biotecnologia; University of Maryland Center for Superconductivity Research; Massachusetts Institute of Technology; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
PURPOSE: Chromatic contrast is a technique used in some areas of medicine to provide better visualization of biological tissues. Based on principles of color composition, a new illumination system was constructed using colored emitting diodes to reproduce the spectral range of visible light. This technique was devised to be used in indirect ophthalmoscopes to improve the visualization of the posterior segment of the eye. METHODS: The original illumination system of a general purpose indirect ophthalmoscope was substituted by a system of color-emitting diodes. RESULTS: Using an electronic interface it was possible to control the intensity of the color lights and therefore generate different wavelengths in the visible spectrum of the light. Preliminary tests undertaken in a mechanical model of the human eye generated very clear and homogenous colors. However in vivo examinations with patients were performed in our laboratory at the IFSC-USP and UNIFESP, and obtained the preliminary results show the possibilities of the chromatic contrast technique, and may represent in the future a differential in the analyses of the posterior segment of the eye. CONCLUSION: The use of color-emitting diodes to reproduce the spectral range of the visible light in indirect ophthalmoscopes seems to be a promising technological advance in the fundoscopy of the eye. This is an innovation that can yield better quality examinations with indirect ophthalmoscopes.
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Determination of chicken meat contamination by porphyrin fluorescence
(Elsevier Science Bv, 2018) Courrol, Lilia Coronato [UNIFESP]; Samad, Ricardo Elgul
Meat quality is normally defined by a combination of factors such as visual appearance, smell, firmness, succulence, tenderness, and flavor. Contamination of poultry meat with pathogens remains an important public health issue since it can cause illnesses due to negligence in handling, cooking or post-cooking storage. Conventionally, meat quality tests are based on visual evaluation or chemical analysis, which have the disadvantages of being subjective and time-consuming. To improve the biological contamination detection accuracy and productivity, the evaluation of porphyrin contents in meat by fluorescence spectroscopy is proposed, considering that most microorganisms and animal cells excrete porphyrins. For this purpose, chicken meat was cut into small pieces and separated in three groups: a control group where the meat was conserved under refrigeration, and two experimental groups in which the pieces were kept for 24 and 30 h at room temperature. Porphyrin was extracted from the meat samples and the fluorescence was measured in the range 550-750 nm, under excitation around 400 nm. The fluorescence lifetime was also studied. To ensure porphyrin synthesis, a concentration of 9.3 mM of delta-Aminolevulinic acid (ALA) was added to each sample, 2 h before porphyrin extraction. The results show that, in meat kept at room temperature and incubated with ALA, the porphyrin fluorescence increased, and a short-lived component was enhanced due to the action of microorganisms, indicating a potential new method to test meat quality.
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Early Diagnosis of Prostate Cancer by Citrate Determination in Urine with Europium-Oxytetracycline Complex
(Soc Applied Spectroscopy, 2012-08-01) Silva, Flavia R. O. [UNIFESP]; Nabeshima, Camila Tiemi [UNIFESP]; Bellini, Maria H.; Courrol, Lilia C. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); IPEN CNEN SP
Normal prostate tissue contains high levels of citrate. in the presence of prostate cancer, the citrate level is diminished. in this paper we show that it is possible to use europium oxytetracycline complex as a citrate fluorescent probe and consequently as a prostate cancer probe. We analyzed normal nude male mice urine and urine from nude male mice in which prostate cancer was induced by intraprostatic inoculation of DU145 cells. the urine samples were collected from the animals at the 7th, 14th, 21st, and 35th days after the surgery procedures. the intensity of europium emission at 615 nm in europium oxytetracycline complex in the presence of citrate increases linearly. the citrate concentrations were determined from a calculated calibration curve. A concentration decrease in malignant prostate urine from the normal (PBS group) urine value from similar to 8.0 mM to similar to 2.4 mM (tumor group at 35th day) was found. the obtained results indicated that europium oxytetracycline provides a significant biomarker for prostate cancer detection with a direct, accurate, noninvasive, and non-enzymatic method for measurement of citrate in biological fluids.
Acesso aberto (Open Access)
O efeito da composição lipídica da membrana no estudo do mecanismo de ação do peptídeo antimicrobiano esculentina 1b (1-18)
(Universidade Federal de São Paulo (UNIFESP), 2019-09-26) Silva, Isabela Moreira [UNIFESP]; Perez, Katia Regina [UNIFESP]; http://lattes.cnpq.br/2250091739407083; http://lattes.cnpq.br/7641887893666670; Universidade Federal de São Paulo (UNIFESP)
The antimicrobial peptides are part of innate immune system of several organisms. They are characterized by the presence of cationic and hydrophobic amino acids that assists in the interaction with plasma membranes. Esculentin 1b (1-18) is an antimicrobial peptide containing 46 amino acids, whose region composed of the first 18 amino acids residues presents bactericidal activity as the whole peptide, without hemolytic activity. The mode of action of antimicrobial peptide Esc 1b (1-18) was studied using mimetic membranes composed of zwitterionic and anionic phospholipids in different physical states. Measurements of carboxyfluorescein leakage, isothermal titration calorimetry and interaction measures using Lagmuir monolayers were made to verify the effect of the peptide on model membranes. To observe the influence of Esc 1b (1-18) in the bilayer, measurements of differential scanning calorimetry and electron paramagnetic resonance were made, and the effect of aggregation caused by the peptide in the membranes was verified using measures of static and dynamic light scattering and Zeta potential. Measurements of circular dichroism and polarization modulation infrared reflection-absorption spectroscopy were made to determine the secondary structure of Esc 1b (1-18) in the presence of vesicles and monolayers, respectively. In general, the results of carboxyfluorescein leakage, isothermal titration calorimetry and maximum insertion pressure show that the peptide interacts mainly with negatively charged and fluid state membranes. Furthermore, it was observed that Esc 1b (1-18) causes a larger influence in the phase transition on DPPG membranes and the peptide inserts deeply on negatively charged membranes. Lastly, it was observed that the peptide presents α-helical secondary structure in the presence of charged membranes. Therefore, the antimicrobial peptide Esculentin 1b (1-18) interacts selectively with negatively charged membranes.
Acesso aberto (Open Access)
Efeito da funcionalização de lipossomas com polímero na eficiência de encapsulamento de clodronato e na estabilidade da vesícula
(Universidade Federal de São Paulo (UNIFESP), 2017-03-29) Ventura, Poliana de Oliveira [UNIFESP]; Daghastanli, Katia Regina Perez [UNIFESP]; http://lattes.cnpq.br/2250091739407083; http://lattes.cnpq.br/6073744163782240; Universidade Federal de São Paulo (UNIFESP)
Encapsulating a medicament can direct it to the targeted tissue, which enables the administration of smaller doses of a certain drug. The liposomes are safe and efficient carriers for the delivery of drugs. Although, due to their high biocompatibility, they are rapidly captured decreasing it’s delivery potential in the targeted tissue. An alternative aiming the avoidance of this effect is the functionalization of the liposomes with molecules that make the accession of immune system components and/or the nonspecific interaction with other tissues more difficult. Utilizing polymers in the surface of these carriers has resulted in an increase in their circulation time. Therefore, the manipulation of the physical-chemistry characteristics, like the kind of polymer, the size, the composition, the pH or temperature variances, of this system is important in the understanding and in the design of new drug-delivery carriers. The aim of the work was to study de physical-chemistry aspects involved in the functionalization of liposomes composed of stearoyl oleoyl phosphatidylcholine (SOPC) and polyethylene glycol 400 monolaurate (PEG400ML), which were obtained by extrusion. The vesicles stability was observed for three consecutive days through different techniques, such as dynamic light scattering measurements (DLS), monitoring their size, and zeta potential measurements, SOPC LUVs carboxyfluorescein leakage assays with different PEG400ML concentrations and comparing SOPC LUVs with cholesterol, already known and described in literature. The results obtained indicate that particles propensity increase and aggregate over the course of days. Although, the kinetic of leakage of carboxyfluorescein show that the vesicles of SOPC with 2,5 mol% of PEG400ML exhibit relatively stable during the tree days of experimente. Corroborate that the studys the measures of DSC showed that the best formulation to work and more stable for application as vehicle of drug delivery carrier has the formulation of SOPC with 2,5 mol% of PEG400ML.
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Enhancement on the Europium emission band of Europium chlortetracycline complex in the presence of LDL
(Elsevier B.V., 2010-05-01) Teixeira, Luciane dos Santos; Grasso, Andrea Nastri; Monteiro, Andrea Moreira; Figueiredo Neto, A. M.; Vieira, Nilson Dias; Gidlund, Magnus; Courrol, Lilia Coronato [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); IPEN CNEN; Universidade de São Paulo (USP)
Low-density lipoprotein (LDL) particles are the major cholesterol-carrying lipoprotein in the human circulation from the liver to peripheral tissues. High levels of LDL-Cholesterol (LDL-C) are known risk factor for the development of coronary artery disease (CAD). the most common approach to determine the LDLC in the clinical laboratory involves the Friedewald formula. However, in certain situations, this approach is inadequate. in this paper we report on the enhancement on the Europium emission band of Europium chlortetracycline complex (CTEu) in the presence of LDL. the emission intensity at 615 nm of the CTEu increases with increasing amounts of LDL. This phenomenon allowed us to propose a method to determine the LDL concentration in a sample composed by an aqueous solution of LDL. With this result we obtained LDL calibration curve, LOD (limit of detection) of 0.49 mg/mL and SD (standard deviation) of 0.003. We observed that CTEu complex provides a wider dynamic concentration-range for LDL determination than that from Eu-tetracycline previously. the averaged emission lifetimes of the CTEu and CTEu with LDL (1.5 mg/mL) complexes were measured as 15 and 46 Its, respectively. Study with some metallic interferents is presented. (C) 2010 Elsevier Inc. All rights reserved.
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Erythrocyte Protoporphyrin Fluorescence as a Biomarker for Monitoring Antiangiogenic Cancer Therapy
(Springer, 2010-11-01) Goes Rocha, Flavia Gomes de [UNIFESP]; Barbosa Chaves, Karen Cristina [UNIFESP]; Gomes, Cinthia Zanini; Campanharo, Camila Barricheli [UNIFESP]; Courrol, Lilia Coronato [UNIFESP]; Schor, Nestor [UNIFESP]; Bellini, Maria Helena [UNIFESP]; IPEN CNEN SP; Universidade Federal de São Paulo (UNIFESP)
Renal cell carcinoma (RCC) remains one of the greatest challenges of urological oncology and is the third leading cause of death in genitourinary cancers. RCCs are highly vascularized and are amenable to antiangiogenic therapy. Endostatin (ES) is a fragment of collagen XVIII that possesses antiangiogenic activity. in this study, we examined the potential of erythrocyte PpIX fluorescence spectroscopy for monitoring the efficacy of antiangiogenic therapy in metastatic renal cell carcinoma (mRCC), using an orthotopic metastatic mouse model. Balb/C-bearing Renca cells were treated with NIH/3T3-LendSN cells. Lung weight, nodule area, microvascular area (MVA), and erythrocyte PpIX fluorescence were evaluated. Emission spectra were obtained by exciting the samples at 405 nm. There was a significant decrease in lung wet weight, lung nodule area and MVA in the treated group compared to the control group (P < 0.001). Significant differences in autofluorescence shape were observed in the 620-650 nm spectral region. the most intense fluorescence peak was observed at similar to 632 nm. the autofluorescence of the control samples was about 53% higher than that of normal blood (P < 0.05). in the group treated with ES, the autofluorescence was about 54% lower than in the control group (P < 0.05). Fluorescence intensity was positively correlated with the nodule area (R (2) = 0.8859; P < 0.001) and MVA (R (2) = 0.9431; P < 0.001) in the ES-treated group. These results demonstrate that the spectroscopic analysis method allows a selective detection of tumor masses. This preliminary study suggests that PpIX fluorescence may be useful as a biomarker for antiangiogenic cancer therapy.
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Erythrocyte Protoporphyrin Fluorescence as a Potential Marker of Diabetes
(Soc Applied Spectroscopy, 2010-04-01) Fauaz, Grasiele [UNIFESP]; Miranda, Adriana Regina; Gomes, Cinthia Zanini; Courrol, Lilia Coronato [UNIFESP]; Silva, Flavia Rodrigues de Oliveira [UNIFESP]; Rocha, Flavia Gomes de Goes [UNIFESP]; Schor, Nestor [UNIFESP]; Bellini, Maria Helena [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); IPEN CNEN SP
Protoporphyrin (PpIX), a porphyrin derivative, is the intermediate metabolic precursor of the heme molecule. Abnormal metabolism of total erythrocyte PpIX has been observed in diseases such as cancer, lead poisoning, psoriasis, iron deficiency anemia and acute porphyries. Diabetes mellitus (DM) is a complex metabolic syndrome in which hyperglycemia is the primary clinical manifestation and contributes to the diabetic complications. The aim of this study was to evaluate the utility of fluorescence spectroscopy of erythrocyte PpIX for monitoring the early stages of diabetes. A total of 14 male C 57BL mice, 6 weeks old, were divided into two groups: diabetic and non-diabetic. Diabetes was induced by intraperitoneal injection of streptozotocin (SZT). Blood cells were cultured with standard and 50 mM supplemented RPMI medium. Blood smears were prepared and stained for qualitative morphology analysis under optical microscopy. Blood porphyrin autofluorescence was analyzed by fluorescence spectroscopy. Characteristic PpIX emission spectra were obtained by exciting the samples at 405 nm. Average blood glucose was lower in the control group than in the diabetic group (156.50 +/- 8.11 mg/dL vs. 371.10 +/- 14.43 mg/dL P < 0.05). Both diabetic and glucose-cultured erythroblasts showed a significant decrease (around 30.5% and 40%, respectively) in the emission band intensity at 635 nm. Our results indicate that the erythrocyte PpIX profile could be used as a biological monitor for diabetes.
Acesso aberto (Open Access)
Estudo da protoporfirina IX como marcador fluorescente da aterosclerose
(Universidade Federal de São Paulo, 2014-12-17) Silva, Monica Nascimento da [UNIFESP]; Courrol, Lilia Coronato [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
Atherosclerosis is a chronic degenerative disease characterized by the presence of injuries with aspects of plaques or atheromas in arteries of medium and great caliber. It is the primary cause of cardiovascular disease and stroke, that in turn represent the main cause of death for disease in the world. This study searches a potential atherosclerosis biomarker that it can make possible a minimum invasive diagnostics method and of low cost. In this study 29 rabbits of the race New Zeland had been separate in two main groups: the Control Group, where the animals had received normal diet and the Experimental Group, where the animals had received hypercholesterolemic diet (1% of cholesterol). In a first study blood was collected and liver and arteries were extracted. A metabolic profile of rabbits was made after 22, 43 and 64 days of the beginning of the diet. The excised arteries had been analyzed by microscopy for verification of the installation of the atherosclerotic process in the rabbits of 0 the 64 days. In a second experiment the rabbits had been followed up to 89 days after the beginning of the diet. In this study the blood was collected each 20 days and excrements weekly. Our objective was to verify of the variations of the amount of porphyrin extracted with acetone, in the blood and excrements, with the atherosclerosis stage. With excrements a calibration curve for the determination of the best amount of fecal mass for optimum volume of acetone was gotten, for the extraction of the coproporphyrin. Optimum result was gotten with 0,10 g of fecal mass for 400 µL of acetone. For the group 89 days it had the administration of amminolevulinic acid, or ALA, before and after the blood collection. The study with ALA was continued in one third and last experiment with rabbits. The study of the porphyrin extraction showed the increase of porphyrin fluorescence as in the blood as in excrements in the group of the hypercholesterolemic diet induction, following the increase of the values of LDL (lipoprotein of low density) and the increase of the atheroma. Already the use of the ALA, resulted in an increase in the of the protoporphyrin IX (PPIX) emission signal in the blood of the experimental group in relation to the control group. This study identified a potential marker of atherosclerosis.
Acesso aberto (Open Access)
Estudo de interações biomoleculares de nanopartículas de ouro ultrapequenas com α- trombina
(Universidade Federal de São Paulo (UNIFESP), 2018-02-22) Silva, Andre Luis Lira da [UNIFESP]; Sousa, Alioscka Augusto Caldeira Araujo [UNIFESP]; http://lattes.cnpq.br/1447746283394507; Universidade Federal de São Paulo (UNIFESP)
Nanopartículas de ouro (NPs) possuem diversas aplicações na área biomédica, podendo ser utilizadas como biosensores para diagnósticos de doenças in vitro, ou ainda como plataformas para novas terapias e diagnósticos por imagem in vivo. Quando imersas em fluido biológico, as NPs podem ser recobertas por proteínas e outras biomoléculas presentes no meio, e essa adsorção não-específicas pode acarretar em alterações indesejadas na estrutura e atividade biológica. Portanto, a compreensão dos mecanismos de interação das NPs com proteínas serve como ponto de partida para entender, ou até mesmo prever, seus efeitos biológicos. Dessa forma, este trabalho teve como objetivo caracterizar as interações moleculares entre NPs ultrapequenas de carga negativa e a α-trombina humana (utilizada como enzima modelo), e estudar as consequências dessas interações na estrutura e atividade enzimática da proteína. Os estudos utilizaram uma combinação de ferramentas biofísicas e bioquímicas, tais como fluorescência, ressonância plasmônica de superfície, e diversos ensaios enzimáticos. Os resultados demonstraram que as NPs interagem preferencialmente em regiões de carga positiva na trombina, denominadas exosítios 1 e 2. A ligação é de caráter eletrostático e possui constate de afinidade KD ≅ 44 nM. As NPs induzem modificações na estrutura secundária da trombina e também alterações estruturais na região do sítio ativo. A ligação das NPs foi capaz de inibir parcialmente a atividade enzimática da trombina (atividade residual de ~ 40%), apresentando características de inibição parcial mista. Esta resposta de inibição parcial por mecanismo alostérico não havia sido descrita anteriormente nas interações de NPs sintéticas com enzimas.
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Evaluation of europium-doped HA/beta-TCP ratio fluorescence in biphasic calcium phosphate nanocomposites controlled by the pH value during the synthesis
(Elsevier Science Bv, 2016) Silva, Flavia R. O.; Lima, Nelson B.; Guilhen, Sabine N.; Courrol, Lilia Coronato [UNIFESP]; Bressiani, Ana Helena A.
Europium-doped hydroxyapatite (HA), beta-tricalcium phosphate (beta-TCP) and biphasic phosphate nanopowders were synthesized by co-precipitation method and their crystal structures and fluorescence properties were investigated depending on the pH of the starting solution. In the range of pH 6-10, HA and beta-TCP phases coexist The beta-TCP proportion increased as the pH of the solution decreased, while HA yields decreased. At pH below 6, monophasic beta-TCP powder was obtained after thermal treatment. In particular, HA and beta-TCP can be used as luminescent materials when activated by Eu3+ ions in substitution of Ca2+ ions. Herein, the Eu3+ ions doped HA and beta-TCP phase composition were analyzed in order to investigate the fluorescence emission of the HA, beta-TCP and biphasic compounds. Eu-doped HA exhibited a red-orange emission at 575 nm with several minor peaks at 610-640 nm, while Eu-doped beta-TCP had an unexpected strong red emission at 610-620 nm and a secondary band at 590-600 nm. In fact, the Eu:beta-TCP integrated emission area is almost 20-fold higher than Eu:HA for the same europium ion concentration. These results demonstrate the potential of Eu:beta-TCP as biomarker for medical applications, as drug release and targeting based on their luminescent properties. (C) 2016 Elsevier B.V. All rights reserved.
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Fluorescence analysis of iodinated acetophenone derivatives
(Elsevier B.V., 2015-03-15) Crivelaro, F.; Oliveira, M. R. S.; Lima, S. M.; Andrade, L. H. C.; Casagrande, G. A.; Raminelli, C. [UNIFESP]; Caires, A. R. L.; Fundacao Univ Fed Grande Dourados; Universidade Estadual de Mato Grosso do Sul (UEMS); Universidade Federal de Mato Grosso do Sul (UFMS); Universidade Federal de São Paulo (UNIFESP)
In the present paper the synthesis and optical characterization of iodinated acetophenone, 4-hydroxy-3-iodoacetophenone and 4-hydroxy-3,5-diiodoacetophenone obtained from 4-hydroxyacetophenone, were carried out. the optical features of iodinated molecules were determined by performing the UV-Vis absorption, fluorescence and thermal lens spectroscopies. the results showed that the optical properties of the 4-hydroxyacetophenone is altered when the iodine atom is inserted, as substituent, in the aromatic ring. Although it was determined that the optical feature was changed when one iodine atom was inserted in the aromatic ring (4-hydroxy-3-iodoacetophenone), the results revealed that emission behavior was strongly altered when two iodine atoms (4-hydroxy-3,5-diiodoacetophenone) were acting as substituents: the fluorescence quantum efficiency increases approximately 60%. (C) 2014 Elsevier B.V. All rights reserved.

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