Time-resolved fluorescence polarization anisotropy and optical imaging of Cybesin in cancerous and normal prostate tissues

Time-resolved polarization-dependent fluorescence of Cybesin in solution and in cancerous and normal prostate tissues were measured. The polarization preservation property of Cybesin in tissue was observed. The fluorescence intensity emitted from a Cybesin-stained cancerous tissue area was found to be much stronger than that from a Cybesin-stained normal tissue area indicating that cancerous prostate tissue takes-up more Cybesin than normal tissue. The polarization anisotropy of Cybesin contained in cancerous prostate tissue was found to be larger than that of Cybesin in normal prostate tissue indicating that a larger degree of polarization was preserved in the Cybesin-stained cancerous tissue due to structures. A static anisotropy component from the emission of cell-bonded Cybesin molecules in tissue and a time-dependent anisotropy component from the emission of un-bonded Cybesin molecules were determined and discussed. The static anisotropy value of Cybesin in stained cancerous tissue was found to be much larger than that in stained normal tissue. The fluorescence polarization difference imaging technique based on the polarization preservation of Cybesin was used to enhance the image contrast between cancerous and normal prostate tissue areas.     

Polarized spectral features of human breast tissues through wavelet transform and principal component analysis

Fluorescence characteristics of human breast tissues are investigated through wavelet transform and principal component analysis (PCA). Wavelet transform of polarized fluorescence spectra of human breast tissues is found to localize spectral features that can reliably differentiate different tissue types. The emission range in the visible wavelength regime of 500–700 nm is analysed, with the excitation wavelength at 488 nm using laser as an excitation source, where flavin and porphyrin are some of the active fluorophores. A number of global and local parameters from principal component analysis of both high- and low-pass coefficients extracted in the wavelet domain, capturing spectral variations and subtle changes in the diseased tissues are clearly identifiable.     

应用光纤生物传感器测量肿瘤的自体荧光光谱

光纤生物传感器是现代生物传感技术中的一个非常重要的类别。当前,许多以荧光检测为手段的光纤生物传感器已经商品化了,但几乎都是依靠检测荧光指示剂的光强来获取生物信息,而直接利用生物样品的自体荧光光谱来获取生物信息的光纤传感系统却还未上市。利用自行研发的一套三维荧光光谱光纤传感系统对新鲜的人体乳腺组织切片进行了研究,实验结果表明乳腺癌变组织与正常组织的自体荧光光谱的峰位和峰强比值存在明显区别,这是因为癌变组织的生化成分发生了根本改变。尽管其间的规律还需进一步探索,但可以展望,自体荧光光谱技术与光纤生物传感技术的结合有潜力成为人体恶性肿瘤在线原位诊断的有利工具。     

Fluorescence Spectroscopy as Tool for Bone Development Monitoring in Newborn Rats

Autofluorescence of the mandible and femur bones taken from newborn rats (7-, 14- and 28-day old) was studied. Endogenous fluorophores were excited with 231 nm, 291 nm, 340 nm and 360 nm wavelengths. Modifications in content and microenvironment of both noncolagenous and collagenous constituents of bone tissue as well as metabolic coenzymes during the bone formation with age were reflected in fluorescence emission spectra. The increase of emission from peptide bonds and tryptophan residues was noted with rat age while for collagen and metabolic coenzymes at the first 2 weeks only. After maternal administration of indinavir the changes in fluorescence intensity and shifts in position of peak maximum were found. The distinct drop of emission from peptide bonds and tryptophan residues in studied bones was detected. In the case of collagen and metabolic coenzymes the red shift of peak maximum was revealed. Fluorescence spectroscopy could be used to follow bone development in newborn rats and effect of maternal indinavir administration on offspring.     

直肠组织的高分辨魔角旋转核磁共振波谱研究

文章对6例直肠癌变及正常组织进行高分辨魔角旋转核磁共振波谱研究,结果显示直肠癌变和正常组织的核磁共振氢谱存在明显差异。这可以通过特征峰面积与0.88处峰积分面积的比值上的差异看出：（1）在化学位移0.75～1.55之间,癌组织各种氨基酸[缬氨酸,异亮氨酸,亮氨酸]与脂肪酸甲基的比值（I₂/I₁）,癌组织乳酸盐与脂肪酸甲基的比值(I₄/I₁)都明显增大。（2）在化学位移1.55～2.90之间,癌变组织中亮氨酸、赖氨酸、异亮氨酸与脂肪酸甲基的比值（I₇/I₁）, 谷氨酸、谷氨酰胺、缬氨酸、琥珀酸与脂肪酸甲基的比值((I₉+I₁₁)/I₁)、天冬氨酸与脂肪酸甲基的比值((I₁₂+I₁₄)/I₁)都较正常组织明显增大。（3）在化学位移2.90～3.49之间,癌变组织氨基酸与脂肪酸甲基的比值（I₁₅/I₁）、胆碱类与脂肪酸甲基的比值((I₁₆+I₁₇)/I₁)、牛磺酸与脂肪酸甲基的比值((I₁₈+I₁₉)/I₁)都较正常组织明显增大。（4）在化学位移3.49～4.50之间,其他代谢物与脂肪酸甲基的比值（I₂₀/I₁）,以及甘油基与脂肪酸甲基的比值（I₂₂/I₁）在癌变组织中都有增大的趋势。（5）化学位移4.5～10之间,癌变组织的核苷酸发生了变化,癌变组织的不饱和脂肪酸与脂肪酸甲基的比值（I₂₄/I₁）明显减小。（6）在化学位移-8～0.75之间,癌变组织的谱峰有减少的趋势。通过上述分析可知,通过癌变与正常组织代谢物NMR谱峰的差异,可以区分癌变和正常组织。说明核磁共振波谱技术可能发展成为一种诊断直肠癌的新方法。     

Study of both fingerprint and high wavenumber Raman spectroscopy of pathological nasopharyngeal tissues

High wavenumber (HW) Raman spectroscopy has weaker fluorescence background compared with fingerprint (FP) region. This study aims to evaluate the discrimination feasibility of nasopharyngeal non‐cancerous and nasopharyngeal cancer (NPC) tissue with both FP and HW Raman spectroscopy. HW Raman spectra of nasopharyngeal tissue were obtained for the first time. Raman spectra were collected to differentiate nasopharyngeal non‐cancerous (n = 37) from NPC (n = 41) tissues in FP (800–1800cm⁻¹), HW (2700–3100cm⁻¹), and integrated FP/HW region. First, to assess the utility of this method, the averaged Raman spectral intensities and intensity ratios of corresponding Raman bands were analyzed in HW and FP regions, respectively. The results show that intensities as well as the ratios of specific Raman peaks might be helpful in distinguishing nasopharyngeal non‐cancerous from NPC tissue with the HW Raman spectroscopy, as with FP Raman reported before. The multivariate statistical method based on the combination of principal component analysis–liner discriminant analysis (PCA‐LDA), together with leave‐one‐patient‐out, cross‐validation diagnostic algorithm, was used for discriminating nasopharyngeal non‐cancerous from NPC tissue, generating sensitivities of 87.8%, 85.4%, and 95.1% and specificities of 86.5%, 91.9%, and 89.2%, respectively, with Raman spectroscopy in the FP, HW, and integrated FP/HW regions. The posterior probability of classification results and receiver operating characteristic curves were utilized to evaluate the discrimination of PCA‐LDA algorithm, verifying that HW Raman spectroscopy has a positive effect on the differentiation for the diagnosis of NPC tissue by integrated FP/HW Raman spectroscopy. What's more, the potential of Raman spectroscopy used for differentiating different pathology NPC tissues was also discussed. The results demonstrate that both FP and HW Raman spectroscopy have the potential for diagnosis and detection in early nasopharyngeal carcinoma, and HW Raman spectroscopy may improve the discrimination of NPC tissue compared with FP region alone, providing a promising diagnostic tool for the diagnosis of NPC tissue. Copyright © 2015 John Wiley & Sons, Ltd.     

Intrinsic Fluorescence of Protoporphyrin IX from Blood Samples Can Yield Information on the Growth of Prostate Tumours

Prostate cancer is one of the most common types of cancer in men, and unfortunately many prostate tumours remain asymptomatic until they reach advanced stages. Diagnosis is typically performed through Prostate-Specific Antigen (PSA) quantification, Digital Rectal Examination (DRE) and Transrectal Ultrasonography (TU). The antigen (PSA) is secreted by all prostatic epithelial cells and not exclusively by cancerous ones, so its concentration also increases in the presence of other prostatic diseases. DRE and TU are not reliable for early detection, when histological analysis of prostate tissue obtained from a biopsy is necessary. In this context, fluorescence techniques are very important for the diagnosis of cancer. In this paper we explore the potential of using endogenous phorphyrin blood fluorescence as tumour marker for prostate cancer. Substances such as porphyrin derivatives accumulate substantially more in tumours than in normal tissues; thus, measuring blood porphyrin concentration by autofluorescence intensity may provide a good parameter for determining tumour stage. In this study, the autofluorescence of blood porphyrin was analyzed using fluorescence and excitation spectroscopy on healthy male NUDE mice and in those with prostate cancer induced by inoculation of DU145 cells. A significant contrast between the blood of normal and cancer subjects could be established. Blood porphyrin fluorophore showed an enhancement on the fluorescence band around 632 nm following tumour growth. Fluorescence detection has advantages over other light-based investigation methods: high sensitivity, high speed and safety. However it does carry the drawback of low specificity of detection. The extraction of blood porphyrin using acetone can solve this problem, since optical excitation of further molecular species can be excluded, and light scattering from blood samples is negligible.     

风湿性关节炎动物模型中血啉甲醚荧光强度的同步检测研究

光动力疗法的疗效依赖于治疗过程中靶组织中光敏剂的含量或浓度 ,而药物在组织中的分布特性是受动物机体调控的 ,因此 ,同一个体不同组织对光敏剂吸收的时间特性需要同时进行检测才能排除个体之间的差异。建立了一套空间三通道激光诱导荧光同步检测装置 ,并用该装置研究了活体大耳白兔风湿性关节炎模型滑膜、软骨和皮肤对血啉甲醚吸收的时间特性。研究结果表明 ,炎性滑膜组织对血啉甲醚的吸收量远大于软骨和皮肤 ,这一差别在静脉给药即刻就很明显 ,在静脉给药后 2 0min内 ,滑膜中的光敏剂药物含量约为软骨和皮肤中的 6倍。因此 ,对于借助血啉甲醚 ,用光动力疗法治疗风湿性关节炎并采用体外照射治疗方案时 ,从注药即刻开始 ,前 2 0min左右进行光照治疗可能是较好的选择。     

The influence of exciton behavior on luminescent characteristics of organic light-emitting diodes

We used N,N′-bis-(1-naphthyl)-N,N′-1-diphenyl-1,1′-biphenyl-4,4′-diamine (NPB), 4,4′-N,N′-dicarbazole-biphenyl (CBP) and tris(8-hydroxyquinoline) aluminum (Alq₃) to fabricate tri-layer electroluminescent (EL) device (device structure: ITO/NPB/CBP/Alq₃/Al). In photoluminescence (PL) spectra of this device, the emission from NPB shifted to shorter wavelength accompanying with the decrease of its emission intensity and moreover the emission intensity of Alq₃ increased relatively with the increase of reverse bias voltage. The blue-shifted emission and the decrease in emission intensity of NPB were attributed to the polarization and dissociation of NPB excitons under reverse bias voltage. The increase of emission intensity of Alq₃ benefited from the recombination of electrons (produced by the dissociation of NPB exciton) and holes (injected from the Al cathode).     

Photoluminescence properties of powder and pulsed laser-deposited PbS nanoparticles in SiO2

Thin films of lead sulfide (PbS) nanoparticles embedded in an amorphous silica (SiO₂) host were grown on Si(1 0 0) substrates at different temperatures by the pulsed laser deposition (PLD) technique. Surface morphology and photoluminescence (PL) properties of samples were analyzed with scanning electron microscopy (SEM) and a 458 nm Ar⁺ laser, respectively. The PL data show a blue-shift from the normal emission at ∼3200 nm in PbS bulk to ∼560-700 nm in nanoparticulate PbS powders and thin films. Furthermore, the PL emission of the films was red-shifted from that of the powders at ∼560 to ∼660 nm. The blue-shifting of the emission wavelengths from 3200 to ∼560-700 nm is attributed to quantum confinement of charge carriers in the restricted volume of nanoparticles, while the red-shift between powders and thin-film PbS nanoparticles is speculated to be due to an increase in the defect concentration. The red-shift increased slightly with an increase in deposition temperature, which suggests that there has been a relative growth in particle sizes during the PLD of the films at higher temperatures. Generally, the PL emission of the powders was more intense than that of the films, although the intensity of some of the films was improved marginally by post-deposition annealing at 400 °C. This paper compares the PL properties of powder and pulsed laser-deposited thin films of PbS nanoparticles and the effects of deposition temperatures.     

Live Imaging of Glucose Homeostasis in Nuclei of COS-7 Cells

Measuring subcellular glucose levels deep in tissues can provide new insights into compartmentalization and specialization of glucose metabolism among different cells. As shown previously, a FRET-based glucose-sensor consisting of two GFP-variants and the Escherichia coli periplasmic glucose/galactose binding protein was successfully expressed in the cytosol of COS7-cells and used to determine cytosolic glucose levels. Recording cytosolic fluorescence intensities in cells located in deeper layers of tissues is often difficult due to loss of signal intensity caused by effects of other cell layers on excitation and emission light. These interfering effects may be reduced by restricting fluorophores to occupy only a fraction of the assayed tissue volume. This can be accomplished by confining fluorophores to a sub-compartment of each cell in the tissue, such as the nucleus. The glucose-sensor was targeted to nuclei of COS7-cells. To determine, whether nuclear glucose levels can be used to track cytosolic changes, nuclear glucose concentrations were quantified as the cells were challenged with external glucose over a range of 0.5 to 10 mM and compared to cytosolic levels. Internal glucose concentrations in both compartments were similar, corresponding to approximately 50% of the external concentration. Taken together, these results indicate that nuclear glucose levels can be used to determine cytosolic levels indirectly, permitting more reliable quantification of fluorescence intensities and providing a tool for measurements not only in cell cultures but also in tissues.     

Effects of light quenching on the emission spectra and intensity decays of fluorophore mixtures

We examined a series of fluorophore mixtures to determine the wavelength selectivity of light quenching and the effects of light quenching on the emission spectra and intensity decays. Light quenching can be accomplished using a single excitation pulse train and quenching wavelength (one-beam) or with longer-wavelength quenching pulses time-delayed relative to the excitation pulses (two-beam). Both one-beam and two-beam light quenching were found to alter the intensity decays of the mixtures. The frequency-domain intensity decay data were analyzed to reveal the fractional intensity of each fluorophore in the mixture and the effects of light quenching on the fractional contribution of each fluorophore to the total intensity. Fluorophores were selected to provide a range of decay times and emission wavelengths. The extent of quenching in the mixtures was dependent on which fluorophore had the higher radiative decay rate and emission intensity at the quenching wavelength. A general theory is presented which describes the intensity decays in terms of the extent of quenching of each fluorophore and the time delay between excitation and quenching pulses. The effects of light quenching on the fractional intensities of each fluorophore in the mixture, recovered from the intensity decay analysis, were found to be in quantitative agreement with that predicted from steady-state measurements of light quenching and from the spectral properties of the fluorophores. The data on light quenching of mixtures demonstrate that light quenching may be used for selective quenching of fluorophores and thus of potential value for studies of multichromophoric systems.     

结直肠组织中脂类的拉曼光谱研究

利用共聚焦显微拉曼光谱系统,检测了结直肠癌组织及邻近正常组织的拉曼光谱234例,从分子水平探讨结直肠癌变的原因。实验结果表明：在900～2 100 cm-1频移范围内,与正常组织比较,归属于结直肠癌组织中脂类伸缩振动的1 067和1 133 cm-1 拉曼峰强度相对较弱,扭转振动的1 299 cm-1与CH面内变形振动的1 264 cm-1拉曼峰的强度比值减少,应用SPSS16.0统计学软件进行平均值计算与比较,正常组织中的1 299和1 264 cm-1的强度比值平均值为3.17,癌变组织的为1.33; 二者的分界值为1.96,以此判别结直肠癌组织和正常组织符合率为94%。研究表明,结直肠癌组织中脂类的链内纵向有序性下降,不饱和度增加。可推测结直肠癌组织中脂类的能量储存增加是引起这些变化的原因,而这些变化将导致细胞膜的流动性增强,从而改变细胞膜的物质运输、能量传递和信号传导,终将引起DNA 结构的变化。因此,脂类的能量分布变化可能是导致细胞癌变的原因之一。     

Ex situ synthesis and optical properties of ZnO-PbS nanocomposites

Zinc oxide (ZnO) and lead sulphide (PbS) nanoparticles separately synthesized by a precipitation method were combined by an ex situ route to prepare ZnO-PbS nanocomposites with different molar ratios of ZnO and PbS. The structure and morphology of the ZnO, PbS and ZnO-PbS samples were analyzed with X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). A UV-vis spectrophotometer was used to collect the absorption and 325 nm He-Cd and 488 nm Ar lasers were used to collect the photoluminescence data from the samples. ZnO nanoparticles showed a broad and stable emission peak at ∼570 nm, while a strongly quantum confined emission from PbS nanoparticles was detected at ∼1344-1486 nm. The ZnO-PbS nanocomposites exhibited dual emission in the visible and near-infrared (NIR) regions that is associated with defects and recombination of excitonic centres in the ZnO and PbS nanoparticles, respectively. The PL intensity of the visible emission from the ZnO-PbS nanocomposite was shown to increase when the ZnO to PbS molar ratio was 5:1 and the emission was almost quenched at molar ratios of 1:1 and 1:5. For different molar ratios of ZnO to PbS, the PL intensity of the NIR emission from the ZnO-PbS nanocomposites was more intense than that of PbS nanoparticles.     

傅里叶变换红外光谱法研究肺组织切片

采用傅里叶变换红外光谱(FTIR)仪并借助OMNI采样器直接、快速地测定了正常肺组织及肺癌组织的红外光谱,通过研究表明,正常肺组织与肺癌组织样品的红外光谱在峰位、峰强及峰形等方面均存在明显而有规律的红外光谱差异,这反映了组织中的蛋白质、核酸和脂类等生物分子在不同性质的组织中含量上的差异。研究表明,FTIR可从分子水平上揭示正常肺组织和肺癌组织的特性,能对正常肺组织和肺癌组织的良、恶性的鉴别提供丰富而可靠的结构信息。     

Investigation of prostate cancer using diffusion-weighted intravoxel incoherent motion imaging

Purpose

The objective of this work was to evaluate the diagnostic performance of the intravoxel incoherent motion (IVIM) model to differentiate between healthy and malignant prostate tissue.

Materials and Methods

Regions of interest were drawn in healthy and cancerous tissue of 13 patients with histologically proven prostate carcinoma and fitted to a monoexponential model [yielding the apparent diffusion coefficient (ADC)] and the IVIM signal equation (yielding the perfusion fraction f, the diffusion constant D and the pseudodiffusion coefficient of perfusion D?). Parameter maps were calculated for all parameters.

Results

The ADC, D and f were significantly (P<.005) lowered in cancerous tissue (1.01±0.22 μm²/ms, 0.84±0.19 μm²/ms and 14.27±7.10%, respectively) compared to benign tissue (1.49±0.17 μm²/ms, 1.21±0.22 μm²/ms and 21.25±8.32%, respectively). Parameter maps of D and f allowed for a delineation of the tumor, but showed higher variations compared to the ADC map.

Conclusion

Apparent diffusion coefficient maps provide better diagnostic performance than IVIM maps for tumor detection. However, the results suggest that the reduction of the ADC in prostate cancer stems not only from changes in cellularity but also from perfusion effects. IVIM imaging might hold promise for the diagnosis of other prostatic lesions.     

Chemiluminescent properties of polyurethane fluorophores containing red and blue chromophore moieties

Polyurethane copolymer fluorophores-containing perylene tetracarboxylic diimide and diphenyl anthracene units were prepared to examine the chemiluminescent properties. The UV-VIS spectrophotometric, photoluminescent and chemiluminescent characteristics were investigated for the monomeric and polymeric fluorophores. The sodium salicylate-catalyzed reaction of bis(2-carbopentyloxy-3,5,6-trichlorophenyl)oxalate with hydrogen peroxide provided a strong chemiluminescent light emission from red to blue color according to the mixing ratio of two chromophore units as analogous to the photoluminescent spectra. Although the chemiluminescent intensity was found to decay biexponentially as a function of measuring time, the chemiluminescent glow lasted for more than 24 h and was visible with the naked eye.     

食管癌患者指甲的红外光谱研究

利用傅里叶红外光谱对正常人,食管癌患者,食管癌术后5个月者的指甲进行了研究。发现他们指甲的红外光谱在频率,强度,峰形等方面均有差异。主要表现在:食管癌患者νs(PO2-)和νas(PO2-)的振动峰均向高波数偏移,术后者回落;癌患者蛋白质C—O基团峰强度增强,术后者峰强度有所减弱,但仍比正常人强;癌患者角蛋白脂质CH2和CH3伸缩振动峰波数有所下降。术后者介于癌患者与正常人之间;食管癌患者角蛋白脂质CH2和CH3弯曲振动峰稍向高波数偏移,术后者恢复至正常人水平;癌患者酰氨Ⅰ带和Ⅱ带都向低波数偏移,术后者介于两者之间。这些差异是应用红外光谱诊断食管癌的基础,表明FTIR光谱在食管癌的早期诊断和快速诊断方面有着十分美好的前景。     

人肺组织与肺癌组织FTIR光谱的统计分析

本文应用统计方法分析了人肺正常组织和肺癌组织的FTIR光谱 ,选择光谱谱型参数 ;峰位、峰高、峰位差、峰高比进行比较分析 ,发现有多个变量可以显示两类光谱的差异 ,选择峰高比参数建立了Logistic预测方程为光谱的应用进行了探索。结果表明可以借助数学方法对组织光谱进行数据转换和分析 ,为了研究大量的组织光谱提供思路。     

Effects of water exchange on MRI-based determination of relative blood volume using an inversion-prepared gradient echo sequence and a blood pool contrast medium

A prostate tumor model in rats was used to compare histometric parameters of prostate cancer physiology with those obtained by magnetic resonance imaging (MRI). The study was focused on vascular physiology as reflected by relative blood volume v(b). Histometry and MRI showed a significant increase in mean v(b) in tumor compared to normal prostate tissue (histometry: normal tissue v(b)=0.69+/-0.19%, tumor tissue v(b)=1.10+/-0.31%, P<.001; MRI: normal tissue v(b)=0.67+/-0.23%, tumor tissue v(b)=1.77+/-0.67%, P<.001). The experimental work showed that MRI yielded a 60.9+/-0.76% higher v(b) than histometry in tumors, while no significant difference in v(b) was found between both methods in normal prostate tissue. Water exchange is known to affect signal intensity on contrast-enhanced MRI. This article investigated the influence of water exchange between intravascular and extravascular space to account for the discrepancy in the values of v(b) obtained with a dynamic inversion-prepared gradient echo MRI sequence and histometry in tumor and normal prostate tissue. The expected influence of water exchange on v(b) was modeled by a computer simulation of the MRI signal and compared with experimental results measured with MRI and histometry. The simulation was based on a two-compartment model indicating that v(b) may be overestimated by MRI. The magnitude of overestimation leads from 10% for the slow water exchange regime to 70% for fast water exchange. Since slow water exchange is probably predominant and even if the observed histological differences in tumor tissue are considered, an overestimation of only 15% due to water exchange is predicted by the simulation. Therefore the overestimation of tumor blood volume by MRI of 60.9% compared to histometry seems to be attributable to additional causes besides water exchange.