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INTRODUCTION: Augmentation cystoplasty (AC) is a surgical option to restore a good capacity bladder reservoir able to fill at low pressure. METHODS: The authors present the main principles for perioperative management for urologic nurses. RESULTS: AC is usually made with a piece of ileum patched to the bladder. Patient education programs are very important and are usually managed by urologic nurses. It begins in preoperative phase with the self-catheterization learning and continue in the postoperative phase with advises and prevention of the urinary mucus. CONCLUSION: AC are tricky surgeries but management and education of patients by urological nurses are key points to avoid chronic infection, stones or AC perforation.
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Enfermagem em Nefrologia/métodos , Assistência Perioperatória/enfermagem , Bexiga Urinária/cirurgia , Coletores de Urina , Humanos , Procedimentos Cirúrgicos Urológicos/métodosRESUMO
We experimentally determine the effective nonlinear second-order susceptibility of gold over the visible spectral range. To reach that goal, we probe by vibrational two-color sum-frequency generation spectroscopy the methyl stretching region of a dodecanethiol self-assembled monolayer adsorbed on a gold film. The sum-frequency generation spectra show a remarkable shape reversal when the visible probe wavelength is tuned from 435 to 705 nm. After correcting from Fresnel effects, the methyl stretching vibrations serve as an internal reference, allowing to extract the dispersion of the absolute phase and relative amplitude of the effective nonlinear optical response of gold in the visible range.
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Worldwide, one person dies every 40 seconds by suicide, a potentially preventable tragedy. A limiting step in our ability to intervene is the lack of objective, reliable predictors. We have previously provided proof of principle for the use of blood gene expression biomarkers to predict future hospitalizations due to suicidality, in male bipolar disorder participants. We now generalize the discovery, prioritization, validation, and testing of such markers across major psychiatric disorders (bipolar disorder, major depressive disorder, schizoaffective disorder, and schizophrenia) in male participants, to understand commonalities and differences. We used a powerful within-participant discovery approach to identify genes that change in expression between no suicidal ideation and high suicidal ideation states (n=37 participants out of a cohort of 217 psychiatric participants followed longitudinally). We then used a convergent functional genomics (CFG) approach with existing prior evidence in the field to prioritize the candidate biomarkers identified in the discovery step. Next, we validated the top biomarkers from the prioritization step for relevance to suicidal behavior, in a demographically matched cohort of suicide completers from the coroner's office (n=26). The biomarkers for suicidal ideation only are enriched for genes involved in neuronal connectivity and schizophrenia, the biomarkers also validated for suicidal behavior are enriched for genes involved in neuronal activity and mood. The 76 biomarkers that survived Bonferroni correction after validation for suicidal behavior map to biological pathways involved in immune and inflammatory response, mTOR signaling and growth factor regulation. mTOR signaling is necessary for the effects of the rapid-acting antidepressant agent ketamine, providing a novel biological rationale for its possible use in treating acute suicidality. Similarly, MAOB, a target of antidepressant inhibitors, was one of the increased biomarkers for suicidality. We also identified other potential therapeutic targets or biomarkers for drugs known to mitigate suicidality, such as omega-3 fatty acids, lithium and clozapine. Overall, 14% of the top candidate biomarkers also had evidence for involvement in psychological stress response, and 19% for involvement in programmed cell death/cellular suicide (apoptosis). It may be that in the face of adversity (stress), death mechanisms are turned on at a cellular (apoptosis) and organismal level. Finally, we tested the top increased and decreased biomarkers from the discovery for suicidal ideation (CADM1, CLIP4, DTNA, KIF2C), prioritization with CFG for prior evidence (SAT1, SKA2, SLC4A4), and validation for behavior in suicide completers (IL6, MBP, JUN, KLHDC3) steps in a completely independent test cohort of psychiatric participants for prediction of suicidal ideation (n=108), and in a future follow-up cohort of psychiatric participants (n=157) for prediction of psychiatric hospitalizations due to suicidality. The best individual biomarker across psychiatric diagnoses for predicting suicidal ideation was SLC4A4, with a receiver operating characteristic (ROC) area under the curve (AUC) of 72%. For bipolar disorder in particular, SLC4A4 predicted suicidal ideation with an AUC of 93%, and future hospitalizations with an AUC of 70%. SLC4A4 is involved in brain extracellular space pH regulation. Brain pH has been implicated in the pathophysiology of acute panic attacks. We also describe two new clinical information apps, one for affective state (simplified affective state scale, SASS) and one for suicide risk factors (Convergent Functional Information for Suicide, CFI-S), and how well they predict suicidal ideation across psychiatric diagnoses (AUC of 85% for SASS, AUC of 89% for CFI-S). We hypothesized a priori, based on our previous work, that the integration of the top biomarkers and the clinical information into a universal predictive measure (UP-Suicide) would show broad-spectrum predictive ability across psychiatric diagnoses. Indeed, the UP-Suicide was able to predict suicidal ideation across psychiatric diagnoses with an AUC of 92%. For bipolar disorder, it predicted suicidal ideation with an AUC of 98%, and future hospitalizations with an AUC of 94%. Of note, both types of tests we developed (blood biomarkers and clinical information apps) do not require asking the individual assessed if they have thoughts of suicide, as individuals who are truly suicidal often do not share that information with clinicians. We propose that the widespread use of such risk prediction tests as part of routine or targeted healthcare assessments will lead to early disease interception followed by preventive lifestyle modifications and proactive treatment.
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Expressão Gênica/fisiologia , Genômica/métodos , Transtornos Mentais , Suicídio , Adulto , Biomarcadores , Estudos de Coortes , Bases de Dados Genéticas/estatística & dados numéricos , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Transtornos Mentais/genética , Transtornos Mentais/metabolismo , Transtornos Mentais/psicologia , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Valor Preditivo dos Testes , Escalas de Graduação Psiquiátrica , Medição de Risco , Fatores de Risco , Adulto JovemRESUMO
BACKGROUND: Besides diseases, the concept of quality of life is increasingly used to account for the consequences of other vulnerability situations that may be encountered by individuals, including young children. However, very few studies have examined children's perception of their quality of life in the context of child welfare and protection, and they yielded mixed results. OBJECTIVES: The objectives of this study were (1) to compare the subjective quality of life of children placed in institution with that of children living in their families, by controlling for child sex, age, socioeconomic and familial status, and (2) to examine its relations with their placement course in the child welfare system. METHOD: The sample of this study was composed of 56 children aged 6 to 11, 28 of which were placed in a child welfare institution. Information about the placement course of institutionalized children was given by their social workers and the quality of life of all participants was assessed with the AUQUEI questionnaire. This self-report, which is based on children's conception of their quality of life, allows assessment of four distinct dimensions in addition to the overall score: leisure, performances, relations and family life, and separation. RESULTS: According to the results, the quality of life of children placed in institutions did not differ from that of children living in their families. However, its perception was closely related to the placement course of institutionalized children in the child welfare system. Whereas maltreated children obtained lower overall and performance scores than their neglected peers, children placed in foster families before institution had a poorer perception of their quality of life in the domains of family life and separations. DISCUSSION: These results are interpreted in light of attachment research and theory. Indeed, the relations between children's quality of life and their placement course could be explained by their high level of attachment disorganization. Finally, the results of this study suggested that children were well aware of their difficulties and that they can easily be identified by directly assessing the children's quality of life.
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Proteção da Criança , Qualidade de Vida , Adolescente , Criança , Maus-Tratos Infantis/psicologia , Família , Feminino , Cuidados no Lar de Adoção , Humanos , Institucionalização , Atividades de Lazer , Masculino , Apego ao Objeto , Orfanatos , Psicologia da Criança , Instituições Residenciais , Autorrelato , Inquéritos e QuestionáriosRESUMO
Nonlinear optical Sum and Difference-Frequency spectroscopies are used to probe and model the surface of thiophenol-functionalised gold nanoparticles grafted on a Si(100) substrate through two different silanization procedures. By scanning the [980-1100 cm(-1)] infrared spectral range with the CLIO Free Electron Laser, ring deformation vibrations of adsorbed thiophenol are investigated. Quantitative data analysis addresses three levels of organization: microscopic, nanoscopic and molecular. Grafting with p-aminophenyl-trimethoxysilane shows an increase of around 40% in surface density of nanoparticles (N(s)) as compared to 3-aminopropyl-triethoxysilane. The relative amplitudes of the resonant and nonresonant contributions to the SFG and DFG spectra are discussed in terms of N(s), Fresnel reflectivity factors and local amplification of the nonlinear signals by coupling to the surface plasmon of the particles. They are shown to quantitatively scale with N(s), as measured by atomic force microscopy. Vibration mode assignment is performed through a critical analysis of literature data on IR and Raman spectroscopies coupled to DFT calculations, for which a methodology specific to molecules adsorbed on gold atoms is discussed.
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Atomic force microscopy (AFM) is used to describe the formation process of polymer/DNA complexes. Two main objectives of this research are presented. The first one is to apply AFM as an effective tool to analyse DNA molecules and different polycation/DNA complexes in order to evaluate their degree of condensation (size and shape). The other one is to search for a relationship between the condensation state of DNA and its transfection efficiency. In this study, linear methacrylate based polymers and globular SuperFect polymers are used in order to induce DNA condensation. Ternary complexes, composed of methacrylate based polymers and polyethylene glycol (PEG)-based copolymers, are also investigated. AFM allows us to confirm good condensation conditions and relate them (or not) to transfection efficiencies. These AFM results (obtained after drying in air) are compared with measurements deduced from Dynamic Light Scattering (DLS) experiments performed in water. This comparison allowed us to identify the structural modifications resulting from deposition on the mica surface.
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DNA/genética , Microscopia de Força Atômica/métodos , Espalhamento de Radiação , Transfecção/métodos , Animais , Células COS , Chlorocebus aethiops , DNA/química , Luz , Metacrilatos/química , Plasmídeos/química , Plasmídeos/genética , Polietilenoglicóis/química , Polímeros/químicaRESUMO
A serotonin-like substance in the organ of Bellonci in the eyestalks of embryos, larvae, and adults of the prawn Palaemon serratus was visualized by the use of two specific antisera against serotonin (5-hydroxytryptamine; 5-HT) in combination with peroxidase-antiperoxidase (PAP). The organ of Bellonci, characterized by compact onion bodies distally and degenerating onion bodies proximally, was the only site of the serotonin-like substance in adults, as well as during development in embryos and larvae. Variations in the content of the 5-HT analogue in the adult were detected during the molting cycle. There was more immunoreactivity in specimens fixed at night than in those fixed in daytime. Likewise, colchicine and nialamide injections enhanced the immunoreactivity of the serotonin-like substance. Extirpations of the medulla externa X organ (MEX), a neurosecretory cell group of the optic ganglion medulla externa, produced the same effect.
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Olho/imunologia , Palaemonidae/imunologia , Serotonina/imunologia , Animais , Ritmo Circadiano , Colchicina/farmacologia , Olho/anatomia & histologia , Imunoquímica , Sistemas Neurossecretores/fisiologia , Nialamida/farmacologia , Fenômenos Fisiológicos Oculares , Palaemonidae/anatomia & histologia , Palaemonidae/fisiologia , Distribuição TecidualRESUMO
The introduction of the confocal laser scanning microscope makes it possible to acquire fluorescent specimens in 3D. We present basic image processing tools to enhance the data and to quantitate the morphology and topography of the intravolume elements. The tools were applied to the description of the spatial distribution of DNA replication sites in mammalian cell nuclei as an example.
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Processamento de Imagem Assistida por Computador/métodos , Lasers , Microscopia Eletrônica/métodos , Microscopia de Fluorescência/métodos , Ultrassonografia , Algoritmos , Artefatos , Linhagem Celular , Núcleo Celular/ultraestrutura , Sistemas Computacionais , DNA/ultraestrutura , Replicação do DNA , Sistemas de Gerenciamento de Base de Dados , Fibroblastos/citologia , Humanos , Aumento da Imagem/métodos , Fase S/genéticaRESUMO
The authors report the first case of arrhythmogenic right ventricular dysplasia presenting with a sudden death due to primary ventricular fibrillation (ventricular fibrillation not preceded by ventricular tachycardia) recorded by the Holter method. The patient was a 56 year old man whose only complaint was near syncopal case is the fact that it is the first documented case of ventricular fibrillation revealing arrhythmogenic right ventricular dysplasia, the diagnosis of which was made at autopsy. In addition, the Holter recording showed the factors which triggered the arrhythmia: the "trigger" of 4 monomorphic ventricular extrasystoles during the minute preceding the ventricular fibrillation; the arrhythmogenic substrate giving rise to late ventricular potentials and, finally, the analysis of the R-R intervals suggesting a role of the sympathetic and parasympathetic nervous systems. Holter recordings could help identify subjects at high risk of severe ventricular arrhythmias.
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Cardiomiopatias/complicações , Morte Súbita Cardíaca/etiologia , Eletrocardiografia Ambulatorial , Ventrículos do Coração/patologia , Fibrilação Ventricular/complicações , Tecido Adiposo/patologia , Arritmias Cardíacas/complicações , Arritmias Cardíacas/diagnóstico , Cardiomiopatias/patologia , Morte Súbita Cardíaca/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fibrilação Ventricular/diagnóstico , Função Ventricular DireitaRESUMO
We report 6 cases of corticotroph macroadenomas which show heterogeneity of clinical and biological features (from Cushing's syndrome to silent adenoma) and heterogeneity of immunocytochemical staining. One patient reported on had skin hyperpigmentation and ACTH hypersecretion without clear abnormal adrenocortical function; we believe that this patient's plasma contained ACTH with very low bioactivity.
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Adenoma/diagnóstico , Hormônio Adrenocorticotrópico/metabolismo , Neoplasias Hipofisárias/diagnóstico , Adenoma/metabolismo , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/metabolismoAssuntos
Síndrome da Imunodeficiência Adquirida/complicações , Calcinose/diagnóstico , Nefropatias/diagnóstico , Adulto , Calcinose/patologia , Feminino , Humanos , Córtex Renal/patologia , Nefropatias/etiologia , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , UltrassonografiaRESUMO
The observation of BrdUrd staining in the nuclei of cells from exponentially growing populations reveals different typical replicating patterns. We propose a methodological approach to order and characterize BrdUrd intranuclear distributions. First, visual ordering of the patterns is assessed using a spectral analysis coupled to a k-nearest neighbors clustering technique. Subsequently, nine topographical features are introduced to characterize the spatial distribution of BrdUrd-tagged fluorescence in the nuclei of proliferating cells. These topographical features are based on a structural approach. The localization of fluorescence spots is expressed in terms of the normalized distance from the nuclear border and its standard deviation. These topographical features are simple to calculate and easy to relate to visual experience.
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Bromodesoxiuridina/análise , Núcleo Celular/ultraestrutura , DNA/análise , Processamento de Imagem Assistida por Computador , Algoritmos , Conversão Análogo-Digital , Núcleo Celular/química , Células Cultivadas , Replicação do DNA , Fibroblastos/ultraestrutura , Imunofluorescência , Análise de Fourier , Humanos , Pulmão , Masculino , Microscopia de FluorescênciaRESUMO
This paper describes the relationship between the BrdUrd replicating pattern of a cell and its localization within the S phase by means of topographical features and DNA content measurement. The present study follows an objective ranking of the BrdUrd patterns obtained from a spectral analysis of the BrdUrd images. The pattern ranking was consistent with the DNA content increase throughout the S phase. Five texture groups were arbitrarily set up for the purpose of multivariate analysis. Nine topographical parameters were computed for each BrdUrd-labelled nucleus. The descriptive quality of these parameters was assessed by means of factorial discriminant analysis. These parameters made it possible to characterize objectively the known pattern distributions of replication sites qualitatively described in the literature.
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Replicação do DNA , Células Eucarióticas/citologia , Processamento de Imagem Assistida por Computador , Bromodesoxiuridina , Núcleo Celular/química , Núcleo Celular/ultraestrutura , DNA/análise , Fibroblastos/ultraestrutura , Imunofluorescência , Análise de Fourier , Humanos , Pulmão , Masculino , Microscopia de Fluorescência , Análise MultivariadaRESUMO
This paper addresses the problem of detecting weak incorporation of BrdUrd and the related efficiency of the denaturation protocols used to unmask this thymidine analog. Evidence is presented that measuring the distribution of BrdUrd-tagged fluorescence intensities by image cytometry generates a standard deviation threshold that discriminates between positive and negative MRC5 cells in vitro. A comparison of the thresholding by standard deviation (SDT) with the usual thresholding by the nuclear total fluorescence intensity (FIT) demonstrated that SDT has a significantly higher sensitivity (99.4-100%, depending on the denaturation protocols) than FIT (94.7 and 74.3%, respectively), although both tests have a high specificity (93% and 100%, respectively) for detecting S cells. Since detecting the S cells is not only dependent on the test used, but also on the denaturation protocols, a quality index (QI) was derived from the standard deviation and the mean value of the non-specific fluorescence of negative cell population versus BrdUrd fluorescence of positive cell population. The following DNA denaturation protocols have been assessed according to QI: acidic denaturation, thermal denaturation in formamide, and thermal denaturation in distilled water. Each denaturation procedure was preceded or not by incubation in either proteinase K or Triton X-100. The results showed that thermal denaturation in formamide, especially when preceded by proteinase K incubation, revealed the largest difference between negative and positive cells. This work also demonstrated that image cytometry of BrdUrd-labelled cells can be suitable for clinical application because of the high sensitivity provided and the small samples needed.
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Bromodesoxiuridina , DNA/análise , Processamento de Imagem Assistida por Computador , Interfase , Desnaturação de Ácido Nucleico , Células Cultivadas , Imunofluorescência , Formamidas , HumanosRESUMO
The intranuclear distribution of newly replicated DNA and of the proliferating cell nuclear antigen (PCNA) was mapped by confocal laser scanning microscopy after simultaneous immunofluorescent labelling of incorporated bromodeoxyuridine (BrdUrd) and PCNA. A mild hydrolysis with HCl followed by an enzymic digestion of DNA was used to produce single-stranded DNA required for BrdUrd immunorevelation, since this procedure preserves PCNA antigenicity. Optical sections obtained with a laser scanning microscope clearly showed a similar distribution of PCNA and BrdUrd within the nuclei, thus confirming previous observations on parallel labelled synchronized cultures. The intranuclear distribution of PCNA and BrdUrd varies concomitantly during the S phase of MCF-7 cells.
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Núcleo Celular/metabolismo , DNA/metabolismo , Proteínas Nucleares/metabolismo , Autoantígenos/metabolismo , Bromodesoxiuridina/metabolismo , Linhagem Celular , Núcleo Celular/imunologia , Replicação do DNA , Imunofluorescência , Humanos , Proteínas Nucleares/imunologia , Antígeno Nuclear de Célula em Proliferação , Fase SRESUMO
The dynamics of microtubular cytoskeleton were studied in tobacco (Nicotiana tabacum cv Xanthi) cells in response to two different plant defense elicitors: cryptogein, a protein secreted by Phytophthora cryptogea and oligogalacturonides (OGs), derived from the plant cell wall. In tobacco plants cryptogein triggers a hypersensitive-like response and induces systemic resistance against a broad spectrum of pathogens, whereas OGs induce defense responses, but fail to trigger cell death. The comparison of the microtubule (MT) dynamics in response to cryptogein and OGs in tobacco cells indicates that MTs appear unaffected in OG-treated cells, whereas cryptogein treatment caused a rapid and severe disruption of microtubular network. When hyperstabilized by the MT depolymerization inhibitor, taxol, the MT network was still disrupted by cryptogein treatment. On the other hand, the MT-depolymerizing agent oryzalin and cryptogein had different and complementary effects. In addition to MT destabilization, cryptogein induced the death of tobacco cells, whereas OG-treated cells did not die. We demonstrated that MT destabilization and cell death induced by cryptogein depend on calcium influx and that MT destabilization occurs independently of active oxygen species production. The molecular basis of cryptogein-induced MT disruption and its potential significance with respect to cell death are discussed.
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Proteínas de Algas/farmacologia , Citoesqueleto/ultraestrutura , Microtúbulos/ultraestrutura , Nicotiana/ultraestrutura , Cálcio/fisiologia , Bloqueadores dos Canais de Cálcio/farmacologia , Células Cultivadas , Citoesqueleto/efeitos dos fármacos , Ácido Egtázico/farmacologia , Proteínas Fúngicas , Microtúbulos/efeitos dos fármacos , Nicotiana/efeitos dos fármacos , Nicotiana/fisiologiaRESUMO
The proliferation of GM16 and 4CDT ras-transformed newborn rat adrenocortical (RTAC) cells and Y1 mouse adrenal tumor cells was inhibited by beticolins, the fungal toxins extracted from Cercospora beticola, at submicromolar concentrations in a dose-dependent manner. Inhibitory concentrations for half the maximum inhibition were 150, 75 and 25 nM for beticolin-1 and 230, 150 and 50 nM for beticolin-2 in GM16, 4CDT and Y1 cells respectively. Beticolins strongly inhibited the production of 11 beta-hydroxysteroids on the second and third days of treatment in a dose-dependent manner between 0.1 and 1 microM. Beticolins were shown by confocal microscopy to be localized in cytoplasmic organelles about 30-40 min after treatment. This finding favors a direct action of beticolins on mitochondrial steroid 11 beta-hydroxylase albeit another less direct mechanism involving a cytoplasmic signaling pathway cannot be excluded.
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Córtex Suprarrenal/efeitos dos fármacos , Neoplasias das Glândulas Suprarrenais/patologia , Genes ras , Inibidores do Crescimento/farmacologia , Hidroxiesteroides/metabolismo , Micotoxinas/farmacologia , Proteínas de Neoplasias/antagonistas & inibidores , Esteroide 11-beta-Hidroxilase/antagonistas & inibidores , Córtex Suprarrenal/metabolismo , Neoplasias das Glândulas Suprarrenais/metabolismo , Animais , Animais Recém-Nascidos , Divisão Celular/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Células Cultivadas , Relação Dose-Resposta a Droga , Compostos Heterocíclicos de 4 ou mais Anéis , Camundongos , Microscopia Confocal , Proteínas de Neoplasias/metabolismo , Ratos , Esteroide 11-beta-Hidroxilase/metabolismo , Relação Estrutura-Atividade , Transfecção , Células Tumorais CultivadasRESUMO
AIM: To explore different effects of 12 beticolins, Cercospora beticola toxins, on ras-transformed adrenocortical cell growth inhibition and their functional mechanism. METHODS: Beticolin-induced inhibition was measured with survival cell number determined by an automated photocolorimetric method. The penetration of beticolin was examined by confocal microscopy. Ras protein determined by Lowry method were separated by 14 % SDS-PAGE and electroblotted to Immobilon-P transfer membrane and detected with pan-Ras (Ab-3) monoclonal antibody. The Ca2+ chelation by beticolin was investigated using a calcium ionophore. RESULTS: Cell growth inhibition was found dose- and time-dependently at submicromolar level for beticolin-1, -2, and -13 (IC50 = 250 nmol/L) and for beticolin-0, 6, and -11 (400 nmol/L < IC50 = 500 nmol/L). The inhibition by beticolin-1 was immediate, independent of cell culture step and not reversible for 3-day treatment. Beticolin-3 and -4 were slightly active (1 micromol/L < IC50 = 2 micromol/L) and beticolin-7, -9, -12, and -5 were inactive at micromolar level. The beticolin-induced cell growth inhibition was correlated with the hydrophobicity of these compounds. Beticolin-1 fluorescence in RTAC cells was detected by confocal microscopy whereas beticolin-3 and -12 were not even after a 24 h incubation period. Beticolin-1-induced cell growth inhibition was partially reverted by calcium ionophore suggesting a role of intracellular Ca2+ chelation by beticolin-1 on cell growth inhibition. Furthermore, beticolin-1 blocked up Ras p21 translocation to membrane and induced accumulation of Ras in the cytosol as an inactive form by different ways. CONCLUSION: Beticolins with high hydrophobicity inhibit tumorigenic cell proliferation by different ways.
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Córtex Suprarrenal/metabolismo , Fungos/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Micotoxinas/farmacologia , Córtex Suprarrenal/citologia , Animais , Animais Recém-Nascidos , Cálcio/metabolismo , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Compostos Heterocíclicos de 4 ou mais Anéis , Proteínas Proto-Oncogênicas p21(ras)/genética , Ratos , Translocação GenéticaRESUMO
Two-color sum-frequency generation spectroscopy (2C-SFG) is used to probe the molecular and electronic properties of an adsorbed layer of the green fluorescent protein mutant 2 (GFPmut2) on a platinum (111) substrate. First, the spectroscopic measurements, performed under different polarization combinations, and atomic force microscopy (AFM) show that the GFPmut2 proteins form a fairly ordered monolayer on the platinum surface. Next, the nonlinear spectroscopic data provide evidence of particular coupling phenomena between the GFPmut2 vibrational and electronic properties. This is revealed by the occurrence of two doubly resonant sum-frequency generation processes for molecules having both their Raman and infrared transition moments in a direction perpendicular to the sample plane. Finally, our 2C-SFG analysis reveals two electronic transitions corresponding to the absorption and fluorescence energy levels which are related to two different GFPmut2 conformations: the B (anionic) and I forms, respectively. Their observation and wavelength positions attest the keeping of the GFPmut2 electronic properties upon adsorption on the metallic surface.