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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 285: 121804, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36122467

RESUMO

The spectra of the live tissue with blood flow measured with 785 nm-excitation light showed a very weak signal due to hemoglobin (Hb). It suggested the possibility to detect eosinophil accumulation in the tissue with the 785 nm-excitation light. The excitation wavelength of 633 nm induced strong fluorescence of sapphire glass that is a material of the ball lens of BHRP (Ball lens top hollow optical fiber Raman probe). On the other hand, the previous study suggested that eosinophil including eosinophil peroxidase (EPO) that showed a strong resonance Raman effect with 633 nm-excitation light. The purpose of the present study is to collect basic information and to evaluate the viability of Raman spectroscopic analysis for the detection of eosinophil accumulation in the live esophagus. BHRP with a sapphire ball lens with 500 µm diameter was applied for measurement of live esophagus tissue of a mouse. In this study, Raman spectra of eosinophil were measured with 633 and 785 nm-excitation. The Raman spectra of eosinophil showed a strong contribution of EPO, suggested that a heme chromophore in EPO had pre-resonance enhancement via Q band with the 785 nm-excitation light. Principal component analysis (PCA) is applied for the analysis of Raman spectra of eosinophil, erythrocyte and other granulocytes. Eosinophil was successfully discriminated from other blood cells in the PCA score plots built for the datasets of the spectra measured with 633 and 785 nm-excitation wavelengths. Consequently, our study demonstrates that Raman spectroscopy with 785 nm-excitation had high viability for in situ analysis of eosinophilic esophagitis (EoE).


Assuntos
Esofagite Eosinofílica , Camundongos , Animais , Esofagite Eosinofílica/diagnóstico , Eosinófilos , Análise Espectral Raman/métodos , Óxido de Alumínio
2.
Int J Mol Sci ; 22(14)2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34298998

RESUMO

The purpose of the present study was to investigate molecular compositions of lipid droplets changing in live hepatic cells stimulated with major fatty acids in the human body, i.e., palmitic, stearic, oleic, and linoleic acids. HepG2 cells were used as the model hepatic cells. Morphological changes of lipid droplets were observed by optical microscopy and transmission electron microscopy (TEM) during co-cultivation with fatty acids up to 5 days. The compositional changes in the fatty chains included in the lipid droplets were analyzed via Raman spectroscopy and chemometrics. The growth curves of the cells indicated that palmitic, stearic, and linoleic acids induced cell death in HepG2 cells, but oleic acid did not. Microscopic observations suggested that the rates of fat accumulation were high for oleic and linoleic acids, but low for palmitic and stearic acids. Raman analysis indicated that linoleic fatty chains taken into the cells are modified into oleic fatty chains. These results suggest that the signaling pathway of cell death is independent of fat stimulations. Moreover, these results suggest that hepatic cells have a high affinity for linoleic acid, but linoleic acid induces cell death in these cells. This may be one of the causes of inflammation in nonalcoholic fatty liver disease (NAFLD).


Assuntos
Morte Celular/efeitos dos fármacos , Meios de Cultura/química , Ácidos Graxos/efeitos adversos , Hepatócitos/metabolismo , Gotículas Lipídicas/química , Análise Espectral Raman , Ácidos Graxos/metabolismo , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Humanos , Ácido Linoleico/farmacologia , Ácido Linoleico/toxicidade , Gotículas Lipídicas/metabolismo , Metabolismo dos Lipídeos , Microscopia Eletrônica de Transmissão , Ácido Oleico/farmacologia , Ácido Palmítico/farmacologia , Ácido Palmítico/toxicidade , Transdução de Sinais/efeitos dos fármacos , Ácidos Esteáricos/farmacologia , Ácidos Esteáricos/toxicidade
3.
Appl Spectrosc ; 75(8): 988-993, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34041958

RESUMO

Coherent anti-Stokes Raman scattering (CARS) spectroscopy is a powerful tool for Raman imaging technology. In contrast, conventional spontaneous Raman spectroscopy is often used for biological analysis with multivariate analysis. This study develops a new type of CARS instrument with a double-wavelength-emission, background-free, electronically tuned Ti:sapphire laser (DW-ETL). DW-ETL generates two laser pulses with different wavelengths simultaneously within its single resonator. The pulse wavelength and buildup time are regulated by acousto-optical tunable filter in the resonator. The present DW-ETL CARS system is free from any mechanical movement to measure a CARS spectrum by controlling each laser pulse of the emission throughout the fingerprint region. Consequently, it is theoretically able to provide stable CARS spectra to apply multivariate analysis in biological applications. The present study demonstrates that the DW-ETL CARS system provides spectra of biomedical samples in the full finger-print region, and the stability and controllability of the system are evaluated.


Assuntos
Óxido de Alumínio , Análise Espectral Raman , Lasers , Titânio
4.
Appl Spectrosc ; 72(11): 1606-1612, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29756993

RESUMO

A technique for the analysis of saccharification reactions by a specific enzyme was developed on the basis of Raman spectroscopy using multivariate analysis. It is a microvolume, quantitative, and in situ technique, which can be used for studying saccharification processes in plant tissues. Prediction models for quantitative analysis of maltose, glucose, and starch were built with partial least squares regression (PLSR) analysis to monitor the saccharification process caused by α-amylase. We examined the reliability of the prediction models built using seven test samples. The spectral regions used to build the models were optimized for each sugar and were selected in such a manner that they did not overlap with strong protein and lipid bands that generally exist in plant tissues. The models were validated by monitoring the composition of reduced sugars and starch in a reactor and by comparing the results with those obtained by a conventional method. The results of Raman analysis and the conventional method showed good agreement for the reaction with α-amylase; however, it is not perfect for reactions with a different enzyme, especially ß-amylase. The results suggest that the present Raman technique is reliable and useful for sugar analysis. However, the prediction model built for a specific enzyme is valid only for that enzyme.


Assuntos
Aspergillus oryzae/enzimologia , Glucose/análise , Maltose/análise , Análise Espectral Raman/métodos , Amido/análise , alfa-Amilases/metabolismo , Aspergillus oryzae/química , Aspergillus oryzae/metabolismo , Ensaios Enzimáticos/métodos , Glucose/metabolismo , Análise dos Mínimos Quadrados , Maltose/metabolismo , Análise Multivariada , Amido/metabolismo
5.
Analyst ; 143(12): 2889-2894, 2018 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-29796444

RESUMO

We have succeeded in discriminating between intact excitatory and inhibitory neuronal cells with Raman analysis. Excitatory and inhibitory neurons have several differences in their electric activities, but it can be difficult to determine their types based only on visual appearances. As Raman spectroscopy does not require any staining or labeling, its use in live neuronal cells is possible. In the present study, we used primary neurons obtained from rat cerebral cortexes, which we cultured on a glial feeder layered culturing dish for 15 days. The Raman spectra of the intact neurons on the dish were obtained; the neurons were then immunostained and their types determined. Partial least squares regression-discriminant analysis (PLSR-DA) was employed for classification of the excitatory and inhibitory neurons. The results demonstrated a high feasibility for use of Raman spectroscopy for discrimination analysis of inhibitory and excitatory neurons in a nondestructive manner.


Assuntos
Análise Discriminante , Neurônios/citologia , Análise Espectral Raman , Animais , Córtex Cerebral/citologia , Análise dos Mínimos Quadrados , Cultura Primária de Células , Ratos , Ratos Wistar
6.
Analyst ; 142(19): 3680-3688, 2017 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-28837186

RESUMO

A miniaturized Raman endoscope (mRE) system was employed to study the effects of anticancer treatment on colorectal tumors in a live murine model. The endoscope is narrow enough to observe the inside of the mouse colon under anesthesia. It has a channel for a ball lens mounted on a hollow fiber Raman probe (BHRP) to measure any targeted point under the visual control of the endoscope. Colorectal cancer tissue was observed to study the alterations of the tissue in response to anticancer drug treatment. Three anticancer drugs, 5-fluorouracil (5-FU), cisplatin (CDDP), and docetaxel, were employed. Although no alteration was recognized in the endoscopic visual observations at 2 weeks after the drug treatment, the Raman spectra obtained in the live mouse colon indicated that molecular changes of lipids and proteins were observed. This study demonstrates that in situ Raman analysis is highly sensitive for detecting the effects of anticancer drugs.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Colorretais/diagnóstico por imagem , Neoplasias Colorretais/tratamento farmacológico , Endoscopia , Análise Espectral Raman , Animais , Cisplatino/farmacologia , Docetaxel/farmacologia , Fluoruracila/farmacologia , Camundongos , Camundongos Endogâmicos BALB C
7.
Sci Rep ; 6: 37068, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27845402

RESUMO

Subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and fat beneath the dermis layer were investigated using a ball lens top hollow optical fiber Raman probe (BHRP). Hamsters were fed with trilinolein (TL) and tricaprin (TC) for six weeks and measurements were carried out every two weeks. The BHRP with an 800 µm diameter fused-silica ball lens was able to obtain information on the subcutaneous fat in a totally non-invasive manner. Changes in the concentration of TL and TC during the treatment were analyzed, and the relationship between fat accumulation and dietary fat was studied. It was found that SAT had, in general, a higher degree of unsaturation than VAT. The accumulation rate of TC found in SAT and VAT was 0.52 ± 0.38 and 0.58 ± 0.4%, respectively, while the TL accumulation rate was 4.45 ± 1.6 and 4.37 ± 2.4%, respectively. The results suggest different metabolic pathways for TC, a typical medium-chain fatty acid, and TL, a long-chain unsaturated fatty acid. Raman subsurface spectra were successfully obtained and used to analyze the subcutaneous fat layer. The accumulation rates of TL and TC found in skin fat were 5.01 ± 3.53% and 0.45 ± 0.36%, respectively. The results demonstrate the high feasibility of Raman spectroscopy for non-invasive analysis of adipose tissue.


Assuntos
Análise Espectral Raman/métodos , Gordura Subcutânea/metabolismo , Animais , Mesocricetus , Gordura Subcutânea/citologia , Triglicerídeos/farmacologia
8.
Analyst ; 141(3): 1027-33, 2016 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-26694647

RESUMO

Esophageal cancer is a disease with high mortality. In order to improve the 5 year survival rate after cancer treatment, it is important to develop a method for early detection of the cancer and for therapy support. There is increasing evidence that Raman spectroscopy, in combination with chemometric analysis, is a powerful technique for discriminating pre-cancerous and cancerous biochemical changes. In the present study, we used Raman spectroscopy to examine early-stage (stages 0 and I) esophageal cancer samples ex vivo. Comparison between the Raman spectra of cancerous and normal samples using a t-test showed decreased concentrations of glycogen, collagen, and tryptophan in cancerous tissue. Partial least squares regression (PLSR) analysis and self-organization maps (SOMs) discriminated the datasets of cancerous and normal samples into two groups, but there was a relatively large overlap between them. Linear discriminant analysis (LDA) based on Raman bands found in the t-test was able to predict the tissue types with 81.0% sensitivity and 94.0% specificity.


Assuntos
Detecção Precoce de Câncer/métodos , Neoplasias Esofágicas/diagnóstico , Informática/métodos , Análise Espectral Raman/métodos , Humanos , Análise dos Mínimos Quadrados , Análise Multivariada , Curva ROC
9.
Analyst ; 140(12): 4238-44, 2015 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-25920444

RESUMO

Raman spectroscopy has previously been applied for studying lipid metabolism. In this study, a ball lens-installed hollow optical fiber Raman probe (BHRP) was used for the noninvasive measurement of skin lipids in hamsters. Our analysis suggested that multi-unsaturated lipids, once converted into a structure containing conjugated double bonds, were oxidized to form peroxides. These results were applied for analyzing lipid metabolism in adipose and skin tissues in hamsters fed tricaprin, saturated medium-chain triglyceride and trilinolein, unsaturated long-chain triglyceride fat diets. Unsaturated lipids formed conjugated structures in skin tissue but not in adipose tissue. Principal component analysis (PCA) revealed that the dietary fat intake correlated strongly with lipid composition in body and skin tissues. Hence, the present results successfully demonstrate that Raman spectroscopy with a BHRP can be a powerful tool for analyzing lipid metabolism.


Assuntos
Gorduras na Dieta/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/metabolismo , Análise Espectral Raman , Animais , Cricetinae , Estudos de Viabilidade , Peroxidação de Lipídeos/efeitos dos fármacos
10.
J Biomed Opt ; 19(6): 067003, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24898605

RESUMO

The present study demonstrates that Raman spectroscopy is a powerful tool for the detection of virus-infected cells. Adenovirus infection of human embryonic kidney 293 cells was successfully detected at 12, 24, and 48 h after initiating the infection. The score plot of principal component analysis discriminated the spectra of the infected cells from those of the control cells. The viral infection was confirmed by the conventional immunostaining method performed 24 h after the infection. The newly developed method provides a fast and label-free means for the detection of virus-infected cells.


Assuntos
Infecções por Adenoviridae/diagnóstico , Adenoviridae , Células HEK293/virologia , Análise Espectral Raman/métodos , Infecções por Adenoviridae/patologia , Humanos , Análise de Componente Principal , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador , Fatores de Tempo
11.
Analyst ; 138(14): 4183-90, 2013 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-23762892

RESUMO

The aim of the present study is to evaluate the capability of a miniaturized Raman endoscope (mRE) system to monitor the advancement of colorectal tumors in model mice as a method that is noninvasive to the tumor itself. Nevertheless, the endoscope is narrow enough to observe the inside of the mouse colon in such a way that is semi-noninvasive to the animal. However, the mRE system allowed the visualization and Raman spectral measurement of any targeted point within the colorectal tumor in model mice under anesthesia, without damaging the tissue (i.e., noninvasively). Continuous monitoring of the same tumor allowed the observation of alterations in its molecular composition and size, along with its advancement. The tumor lesion was discriminated from normal tissues of the control mouse with an accuracy of 86.8%. We succeeded in visualizing and performing Raman spectral observations on a shrinking polyp type tumor. The Raman analysis suggested that it was not cured but supposedly transformed to another tumor type.


Assuntos
Neoplasias do Colo/patologia , Modelos Animais de Doenças , Análise Espectral Raman/métodos , Fatores Etários , Animais , Azoximetano/toxicidade , Carcinógenos/toxicidade , Neoplasias do Colo/induzido quimicamente , Sulfato de Dextrana/toxicidade , Progressão da Doença , Camundongos , Camundongos Endogâmicos BALB C
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