Value Of Fluorescence Research Articles

Prospective evaluation of FISH for detecting upper tract urothelial carcinoma in voided urine specimens.

The aim of the present study was to estimate the diagnostic value of fluorescence in situ hybridization (FISH) analysis of tumor cells in voided urine specimens for detecting upper tract urothelial carcinoma (UTUC). Cytology and FISH analyses were conducted on voided urine collected in the morning from 125 patients with suspected UTUC. During follow-up, ureteroscopy with biopsy and histopathology were used to confirm the presence of tumors. The average follow-up time was 23.8 months (range, 6-36 months). A total of 8 patients who could not be contacted until the last follow-up were excluded from the study. Of the remaining 117 patients, 19 were histologically demonstrated to have UTUC, of whom, 3 patients had stage pTis disease, 6 had stage pTa disease, 5 had stage pT1 disease and 5 had stage pT2 disease (7 G1, 8 G2 and 4 G3). The overall sensitivity of FISH to detect UTUCs in voided urine specimens was 84.21% (16/19), whereas that of cytology was 42.11% (8/19) (P<0.05). The overall specificity of FISH to detect UTUCs in voided urine specimens was 89.80% (88/98), compared with 94.90% (93/98) of cytology (P>0.05). The positive predictive value (PPV) and negative predictive value of FISH were 80.00% (16/20) and 97.78% (88/90), respectively, whereas those of cytology were 100.00% (8/8) (P>0.05) and 90.29% (93/103) (P>0.05), respectively. The present data indicated that FISH was a method capable of detecting UTUCs in voided urine specimens with good sensitivity and specificity, although it exhibited a high rate of false positivity and low PPV.

Karyotype analysis and fluorescence in situ hybridization detection of 122 patients with myelodysplastic syndrome

To assess the value of karyotype analysis and fluorescence in situ hybridization(FISH) assay for the diagnosis of myelodysplastic syndrome (MDS). The karyotypes of 122 initially treated MDS patients were analyzed with conventional R-banding and FISH using probes including GLP CSF1R/D5S23, D5S721, GLP EGR1/D5S23, D5S721, GLP D7S486/CSP7, GLP D7S522/CSP7, GLP D20S108, CSP8 and CSP X/Y. The detection rate of chromosomal abnormalities was 54.9% for the 122 patients. Among these, those involving 3 or more chromosomes are most common (16.4%), followed by +8(14.8%), -7/7q-(7.4%), -5/5q-(5.7%), 20q-(2.5%), and -Y in male patients (5.0%). Two MDS-RAEB II patients detected with t(8;21) should be diagnosed with acute myelocytic leukemia. FISH analysis showed that 54 patients were positive (44.3%). Among these, 30.3% had CSP8 amplification, followed by GLP D7S486/CSP7 and GLP D7S522/CSP7 deletion (12.3%), GLP CSF1R/D5S23, D5S721 and GLP EGR1/D5S23, D5S721 deletion (9.8%), GLP D20S108 deletion (7.4%), and CSPX/Y deletion (5%). With a detection rate of 54.9%, R-banding still constitutes the basic examination for MDS. As detection of interstitial chromosomal abnormalities in MDS can be greatly enhanced by FISH, combined karyotype analysis and FISH can improve the diagnosis of MDS and facilitate assessment of its prognosis.

Using polyaspartic acid hydro-gel as water retaining agent and its effect on plants under drought stress.

Polyaspartic acid (PASP) hydrogel is an important and widely applied water-retaining agent, thanks to its special space network structure which contains a carboxyl group attached on the side chain. In this study, the PASP hydrogel with high water absorption rate (300–350 g H2O/g hydrogel) was developed and adopted to transplant Xanthoceras sorbifolia seedlings in the ecological restoration project of Mount Daqing National Nature Reserve. Transplantation experiments showed that the survival rate and leaf water content index for X. sorbifolia seedlings were increased by 8–12% and 4–16%, respectively. Additionally, compared with the counterpart without PASP hydrogel, the value of chlorophyll fluorescence that was considered as one of the most important indicators of plant physiology, was significantly improved with the addition of PASP hydrogel. The PASP hydrogel displays a promising future for the applications of increasing the survival rate and simultaneously alleviating the drought stress effects on the pioneer plants in arid and semi-arid areas.

Modification of collagen fiber after PDT in porcine skin models by two photons microscopy analysis

Modification of collagen fiber after PDT in porcine skin models by two photons microscopy analysis

Photodynamic therapy combined to optical clearing agents for melanoma treatment

Photodynamic therapy combined to optical clearing agents for melanoma treatment

Mean corpuscular volume of control red blood cells determines the interpretation of eosin-5'-maleimide (EMA) test result in infants aged less than 6 months.

Eosin-5′-maleimide (EMA) binding test is a flow cytometric test used to detect hereditary spherocytosis (HS). To perform the test sample from patients, 5–6 reference samples of red blood are needed. Our aim was to investigate how the mean corpuscular volume (MCV) of red blood cells influences on the value of fluorescence of bounded EMA dye and how the choice of reference samples affects the test result. EMA test was performed in peripheral blood from 404 individuals, including 31 children suffering from HS. Mean fluorescence channel of EMA-RBCs was measured with Cytomics FC500 flow cytometer. Mean corpuscular volume of RBCs was assessed with LH750 Beckman Coulter. Statistical analysis was performed using Graph Pad Prism. The correlation Spearman coefficient between mean channel of fluorescence of EMA-RBCs and MCV was r = 0.39, p < 0.0001. Interpretation of EMA test depends on MCV of the reference samples. If reference blood samples have lower MCV than the patients MCV, EMA test result might be negative. Due to different MCV values of RBCs in infancy and ca. Three months later, EMA test in neonates might be interpreted falsely negative. Samples from children younger than 3 months old had EMA test result 86.1 ± 11.7 %, whereas same samples that analyzed 4.1 ± 2.1 later had results of 75.4 ± 4.5 %, p < 0.05. Mean fluorescence of EMA-bound RBC depends on RBC’s volume. MCV of reference samples affects EMA test results; thus, we recommend selection of reference samples with MCV in range of ±2 fL compared to MCV of patient RBC’s.

Fluorescence diagnosis of pre-invasive cervical pathology

Results of local fluorescence spectroscopy in 185 women with underlying and pre-invasive disease of cervix and high-risk HPV infection are represented. Fluorescence study was performed 2h after intravenous injection of fotoditazin in a dose of 1 mg/kg (wavelength 636.5 nm). Accumulation of the photosensitizer was estimated by diagnostic parameter (DP) value, calculated as mean value of fluorescence scaled to each type of tissue. For normal tissues DP accounted for 0.6±0.4, showing accumulation of the photosensitizer. According to the study the medication did not also accumulate in retention cysts (DP 0.3±0.1), explaining low efficiency of photodynamic therapy for this pathology. The accumulation of fotoditazin depends significantly on type of pathologic tissue. In patients with inflammation, leukoplakia and CIN I accumulation of the photosensitizer in pathologic foci was negligible: DP accounted for 1.7±0.2, 1.8±0.2 and 2.1±0.3, respectively. In sites of endometriosis and CIN II DP was significantly higher and accounted for 8.3±2.1 and 14.1±4.1, respectively. The greatest accumulation of the photosensitizer was registered in sites of CIN III, squamous cell carcinoma and adenocarcinoma. Though DP value for these pathologies had almost no difference and accounted for 23.1±4.7, 22.7±1.8 and 23.3±1.4, respectively. For fluorescence diagnosis of severe dysplasia in 48% of patients borders of fluorescence regions were beyond lesions detected for extended colposcopy with additional areas of fluorescence. Targeted biopsy of these regions proved pathology in all patients: CIN II, CIN III, mild dysplasia or CIS. Thus, local spectroscopy allows to diagnosis multifocal lesions on cervix, to define correctly borders of lesion and consider excisional biopsy in-time.

A novel way to monitor urine concentration: fluorescent concentration matrices.

The amount of water found in urine is important diagnostic information; nevertheless it is not yet directly determined. Indirectly, the water content in urine is expressed by its density (specific gravity). However, without the diuresis value it is not possible to determine whether the increase in density of urine is due to a decrease in water secretion or an increase in the concentration of secreted substances. This problem can be solved by the use of fluorescent concentration 3D-matrices which characterise urine concentration through the pφ (or -logφ) value of the first fluorescence centre. The urine fluorescent concentration 3D-matrix was created by the alignment of the synchronous spectra of the dilution series of urine starting from undiluted (pφ = 0) to 1000-fold diluted urine (pφ = 3). Using the fluorescence concentration 3D-matrix analysis of the urine samples from healthy individuals, a reference range was established for the value pφ, determining the normal, concentrated or diluted type of urine. The diagnostic potential of this approach was tested on urine samples from two patients with a chronic glomerulonephritis. The pφ value of the urine fluorescence concentration 3D-matrix analysis determines whether the urine sample falls within the normal, concentrated or diluted type of urine. This parameter can be directly utilised in sportsmen's hydration state monitoring, as well as in the diagnosis and treatment of serious diseases. An important advantage of this novel diagnostic approach is that a 12/24 h urine collection is not required, which predetermines it for use especially within paediatrics.

Diagnostic accuracy of bronchial brush cytology and the added value of immunohistochemistry and fluorescence in situ hybridization of pulmonary neuroendocrine tumors.

Background:Bronchial brush (BB) cytology carries low sensitivity for detecting neuroendocrine carcinomas (NECs), including typical carcinoid (TC) tumors of the lung. We aimed to investigate the detection of neuroendocrine tumors including TC through BB routine cytology cell block (CB), immunohistochemistry (IHC), and fluorescence in situ hybridization (FISH).Materials and Methods:A SNOMED search showed 187 lung biopsy or resection specimens from 2008 through 2011 containing neuroendocrine or carcinoid in the diagnosis. Residual BB specimens retained in PreservCyt were used to prepare a ThinPrep slide for FISH analysis. CBs were stained with H and E and IHC for chromogranin and synaptophysin.Results:Of the 187 cases, 16 had residual BB material available within 1 year of diagnosis and were used in CB preparation for IHC and FISH slides. Cytologic evaluation determined 1 case positive for malignancy (small cell lung carcinoma [SCLC]), 1 suspicious for adenocarcinoma, and 14 negative for malignancy. On the basis of histologic diagnosis, FISH was performed. SCLC showed polysomy (86% abnormal cells); 2 TC tumors showed a gain of 7p12 (15% abnormal cells) and a gain of 5q15 (72% abnormal cells), respectively. Two cases had CBs with positive immunoreactivity for chromogranin and synaptophysin. The sensitivity for detection of NEC was 18.8%, 15.4%, and 25% for cytologic evaluation, CB, and FISH, respectively.Conclusion:Neuroendocrine tumors, including TC are difficult to detect with BB cytologic evaluation, most likely because tumor cells lack in the specimen. Assessment of further studies is needed to explore the role of cytology and ancillary methods for detection of these tumors.

The utility of fluorescence in situ hybridization for diagnosis and surveillance of bladder urothelial carcinoma.

To evaluate the clinical value of fluorescence in situ hybridization (FISH) for diagnosis and surveillance of bladder urothelial carcinoma (BUC). Between November 2010 and December 2013, patients suspected of having BUC were examined using urine cytology and FISH assay. Based on histopathological examination results, FISH results were com­pared with urine cytology. In addition, patients with a history of non-muscle invasive BUC were also examined using urine cytology and FISH assay at the first time of visit and then monitored with cystoscopy during follow-up period. A total of 162 patients included in this study and 12 patients were excluded due to uninformative FISH assays. The remaining 150 patients consisted of 108 patients suspected for BUC and 42 patients with a history of non-muscle invasive BUC. The sensitivities of FISH analysis and urine cytology were 72.8% and 27.2%, respectively, and the difference was statistically significant (P <.05). Difference between specificity of urine cytology (100%) and FISH assay (85%) was not statistically significant (P >.05). At the first visit, of 42 patients, one patient had positive cystoscopy, and FISH assay was positive in 26 of 41 patients with negative cystoscopy. During the follow-up period (mean, 29.5 months), 18 of 26 patients developed recurrence, and recurrence occurred in only one of 15 patients with negative FISH analysis. Our results suggest that FISH analysis can be used as a non-invasive diagnostic tool for patients suspect­ed of having new BUC. In addition, FISH analysis may provide important prognostic information to better define the individual risk for BUC recurrence.& nbsp;

Recurrence and progression in patients with non-muscle invasive bladder cancer: prognostic models including multicolor fluorescence in situ hybridization molecular grading.

To test the prognostic value of multicolor fluorescence in situ hybridization analyses of tumor cells in urine for prediction of the recurrence and progression of tumor in patients with intermediate risk non-muscle invasive bladder cancer. A total of 168 patients with non-muscle invasive bladder cancer were included in the study. Fluorescence in situ hybridization was carried out on the bladder wash urine collected before resection. Tumors were classified as low molecular grading if they had a diploid chromosomal pattern or only a loss of p16 or ch3 aneuploidy, and as high molecular grading if they showed aneuploidy of ch7 or 17. Cox regression models assessed the added prognostic value of fluorescence in situ hybridization for primary tumor recurrence or progression, respectively. Median follow up was 67 months. A total of 57% of tumors were classified as low molecular grading. The 2- and 5-year recurrence-free survival was 68% and 49% for low molecular grading, and 47% and 30% for high molecular grading, respectively. The 2- and 5-year progression-free survival was 95% and 84% for low molecular grading, and 79% and 58% for high molecular grading tumor patients, respectively. Molecular grading (hazard ratio 1.60; P = 0.03) was associated with recurrence, when also accounting for histopathology and a patient's characteristics. Both cancer severity score (hazard ratio 1.51; P < 0.01) and molecular grading (hazard ratio 2.53; P < 0.01) independently and positively predicted progression in multivariable models. The C-index for predicting recurrence increased from 0.58 to 0.61 when molecular grading fluorescence in situ hybridization was included in the model, and from 0.68 to 0.72 when predicting progression. Fluorescence in situ hybridization-based molecular grading increases the accuracy of a prognostic model, predicting both recurrence and progression in patients with intermediate risk non-muscle invasive bladder cancer.

Extraction of intrinsic fluorescence from single fiber fluorescence measurements on a turbid medium: experimental validation.

The detailed mechanisms associated with the influence of scattering and absorption properties on the fluorescence intensity sampled by a single optical fiber have recently been elucidated based on Monte Carlo simulated data. Here we develop an experimental single fiber fluorescence (SFF) spectroscopy setup and validate the Monte Carlo data and semi-empirical model equation that describes the SFF signal as a function of scattering. We present a calibration procedure that corrects the SFF signal for all system-related, wavelength dependent transmission efficiencies to yield an absolute value of intrinsic fluorescence. The validity of the Monte Carlo data and semi-empirical model is demonstrated using a set of fluorescent phantoms with varying concentrations of Intralipid to vary the scattering properties, yielding a wide range of reduced scattering coefficients (μ's = 0-7 mm (-1)). We also introduce a small modification to the model to account for the case of μ's = 0 mm (-1) and show its relation to the experimental, simulated and theoretically calculated value of SFF intensity in the absence of scattering. Finally, we show that our method is also accurate in the presence of absorbers by performing measurements on phantoms containing red blood cells and correcting for their absorption properties.

Chlorophyll fluorescence induction, chlorophyll content, and chromaticity characteristics of leaves as indicators of photosynthetic apparatus senescence in arboreous plants.

Parameters of chlorophyll fluorescence induction (CFI) are widely used for assessment of the physiological state of higher plant leaves in biochemical, physiological, and ecological studies and in agricultural applications. In this work we have analyzed data on variability of some CFI parameters - ΦPSII(max)= Fv/Fm (relative value of variable fluorescence), qNPQ (non-photochemical quenching coefficient), RFd ("vitality index") - in autumnal leaves of ten arboreous plant species of the temperate climatic zone. The correlation between the chlorophyll content in the leaves and fluorescence parameters characterizing photosynthetic activity is shown for two representative species, the small-leaved linden Tilia cordata and the rowan tree Sorbus aucuparia. During the period of mass yellowing of the leaves, the ΦPSII(max) value can be used as an adequate characteristic of their photochemical activity, while in summer the qNPQ or RFd values are more informative. We have established a correlation between the ΦPSII(max) value, which characterizes the maximal photochemical activity of the photosystem II, and "chromaticity coordinates" of a leaf characterizing its color features. The chromaticity coordinates determined from the optical reflection spectra of the leaves serve as a quantitative measure of their hues, and this creates certain prerequisites for a visual expert assessment of the physiological state of the leaves.

Early monitoring drug-resistance of patients with BCR/ABL(+) ALL by DCDF-FISH

This study was aimed to investigate the application value of the dual color dual fusion fluorescence in situ hybridization (DCDF-FISH) in BCR/ABL (+) acute lymphoblastic leukemia patients with complex chromosomal translocation. The clinical presentations of a patient with ALL were monitored regularly by bone marrow cell morphology test, chromosome analysis, flow cytometry and DCDF-FISH technique, and the reaction of patients to treatment and disease progression were dynamically observed by DCDF-FISH. The results indicated that the patient showed the typical presentation of B lineage acute lymphoblastic leukemia (B-ALL) with expression of CD10, CD19 and CD34; the chromosome analysis showed 46,XY, i(8), ider(9)t (9; 22) [23]/47, idem, +der(22) t (9;22) [7] karyotype in the bone marrow cells, FISH showed that 83% cells contained BCR/ABL fusion gene in the patient's bone marrow, among which 5% cells showed 1R1G2F signalling model, 14% cells showed 1R1G3F, and 64% cells showed 1R1G4F. The patient got complete remission when the imatinib chemotherapy combined with VTLP was carried out, and the tumor cells decreased to 19%, but the cells with 1R1G2F signal model increased to 18%. The 1R1G2F cell signal model increased up to 38% when patient relapsed. The patient died of the drug-resistance. It is concluded that the BCR/ABL (+) leukemia patient with complex translocation has multiple tumor cell subsets, and the responses of different cell subsets to the treatment are different, therefore the response to therapy and drug resistance of patient can be monitored early by the signal model of DCDF-FISH and the observation of dynamical changes of different cell subset.

A cancer cell-activatable aptamer-reporter system for one-step assay of circulating tumor cells.

The current antibody-mediated numeration assays of circulating tumor cells (CTCs) require multiple steps and are time-consuming. To overcome these technical limitations, a cancer cell-activatable aptamer-reporter was formulated by conjugating a biomarker-specific aptamer sequence with paired fluorochrome-quencher molecules. In contrast to the antibody probes, the intact aptamer-reporter was optically silent in the absence of cells of interest. However, when used in an assay, the aptamer selectively targeted cancer cells through interaction with a specific surface biomarker, which triggered internalization of the aptamer-reporter and, subsequently, into cell lysosomes. Rapid lysosomal degradation of the aptamer-reporter resulted in separation of the paired fluorochrome-quencher molecules. The released fluorochrome emitted bright fluorescent signals exclusively within the targeted cancer cells, with no background noise in the assay. Thus, the assays could be completed in a single step within minutes. By using this one-step assay, CTCs in whole blood and marrow aspirate samples of patients with lymphoma tumors were selectively highlighted and rapidly detected with no off-target signals from background blood cells. The development of the cancer cell-activatable aptamer-reporter system allows for the possibility of a simple and robust point-of-care test for CTC detection, which is currently unavailable.

Optimization of resazurin-based viability staining for quantification of microbial biofilms

The resazurin-based viability staining is often used to quantify viable biofilm cells grown in microtiter plates (MTP). The non-fluorescent resazurin is reduced by metabolically active cells to resorufin which is fluorescent. The amount of fluorescence generated is related to the number of viable cells present. Unfortunately, the linear range of the method is restricted and the lower limit of quantification is approximately 106 colony forming units (CFU) per biofilm. The goal of the present study was to optimize this method to broaden its applicability. We added fresh growth medium and resazurin to mature Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia cenocepacia and Candida albicans biofilms formed in MTP. Subsequently, the increase in resazurin-based fluorescence was followed over time and we determined the time needed to reach a specific value of fluorescence as well as the time to reach the maximum fluorescence. These time points correlate with the number of viable cells that were initially present and results were compared to plate counts. Using these alternative read-outs, we were able to extend the linear range from 106–108 to 103–108 CFU per biofilm, meaning that lower numbers of viable cells can be measured and the effect of anti-biofilm treatments can be quantified more accurately. Moreover, this approach is less expensive and less laborious than conventional plating techniques.

5-Aminolevulinic Acid Induced Fluorescence Is a Powerful Intraoperative Marker for Precise Histopathological Grading of Gliomas with Non-Significant Contrast-Enhancement

BackgroundIntraoperative identification of anaplastic foci in diffusely infiltrating gliomas (DIG) with non-significant contrast-enhancement on MRI is indispensible to avoid histopathological undergrading and subsequent treatment failure. Recently, we found that 5-aminolevulinic acid (5-ALA) induced protoporphyrin IX (PpIX) fluorescence can visualize areas with increased proliferative and metabolic activity in such gliomas intraoperatively. As treatment of DIG is predominantely based on histopathological World Health Organisation (WHO) parameters, we analyzed whether PpIX fluorescence can detect anaplastic foci according to these criteria.MethodsWe prospectively included DIG patients with non-significant contrast-enhancement that received 5-ALA prior to resection. Intraoperatively, multiple samples from PpIX positive and negative intratumoral areas were collected using a modified neurosurgical microscope. In all samples, histopathological WHO criteria and proliferation rate were assessed and correlated to the PpIX fluorescence status.ResultsA total of 215 tumor specimens were collected in 59 patients. Of 26 WHO grade III gliomas, 23 cases (85%) showed focal PpIX fluorescence, whereas 29 (91%) of 33 WHO grade II gliomas were PpIX negative. In intratumoral areas with focal PpIX fluorescence, mitotic rate, cell density, nuclear pleomorphism, and proliferation rate were significantly higher than in non-fluorescing areas. The positive predictive value of focal PpIX fluorescence for WHO grade III histology was 85%.ConclusionsOur study indicates that 5-ALA induced PpIX fluorescence is a powerful marker for intraoperative identification of anaplastic foci according to the histopathological WHO criteria in DIG with non-significant contrast-enhancement. Therefore, application of 5-ALA optimizes tissue sampling for precise histopathological diagnosis independent of brain-shift.

Clinical application of BCR/ABL probes in myeloproliferative disorders

This study was purposed to explore the application value of fluorescence in situ hybridization (FISH) detection in differential diagnosis of chronic myeloproliferative disorders (CMPD) and Ph(+) acute lymphoblastic leukemia (Ph(+) ALL), as well as in dynamic monitoring of minimal residual disease (MRD) after treatment. The BCR/ABL fusion gene of newly diagnosed and treated cases was detected by using BCR/ABL (ES) probe and BCR/ABL (DF) probe respectively. The results showed that among 49 newly diagnosed cases considered as CMPD, 28 cases met the criterion of CML morphologically, out of them 23 cases were eventually diagnosed to be CML and with morphological consistent rate 82.1% (23/28), the sensitivity and specificity all were 100% (23/23). The BCR/ABL positive rate of eventually diagnosed cases was 81.3% ± 17.7%. Among 13 cases received allogeneic haemopoietic stem cell transplantation (allo-HSCT), 9 cases achieved long-term disease-free survival and 4 cases relapsed, the several monitoring for whom after donor lymphocyte infusion (DLI) and imatinib treatment or allo-HSCT showed BCR/ABL negative. Among 16 cases treated with imatinib, 11 cases remained BCR/ABL negative after 1 year; 5 cases showed BCR/ABL positive during 6, 7 and 10 years after treatment, respectively, but out of them BCR/ABL positive in 1 case turned negative after allo-HSCT. It is concluded that the FISH is sensitive and specific diagnostic technique, the detection of BCR/ABL fusion gene in newly diagnosed and treated cases by using 2 different probes can help to fast and accurately determine the differential diagnosis for CML and Ph(+) ALL, and dynamically monitor the MRD after treatment with imatinib and allo-HSCT.

Fluorescein for vascular and oncological neurosurgery

Dear Sir: With interest, we have read the article by Roberto Rey-Dios and Aaron A. Cohen-Gadol: Technical principles and neurosurgical applications of fluorescein fluorescence using a microscope-integrated fluorescence module (Acta Neurochir. [2013] 155:701–706). The authors explore new technology proffered by the Zeiss company, the YELLOW 560 system for neurosurgery using fluorescein. The images obtained for vascular surgery appear impressive. In contrast to the Zeiss INFRARED 800 or FLOW 800 systems, which use indocyanine green (ICG), fluorescein is directly visible within the vessels, which the surgeon can inspect and directly manipulate. FLOW 800, on the other hand, gives an image only available on the screen of the microscope, but has the advantage of giving semi-quantitative information that has been explored by our and other groups [2, 3]. Years ago, before we had access to the INFRARED 800 system, we used fluorescein for vascular surgery with the Zeiss Blue 400 system. This system gives violet blue illumination light (375–440 nm), and thus covers part of the excitation spectrum of fluorescein. The BLUE 400 emission filter effectively allows visualization of fluorescein, thus giving similar information to the YELLOW 560 system without additional costs to neurosurgeons with access to BLUE 400 technology (Fig. 1). Although the background is blue, the fluorescence is very vivid and the contrast of vasculature to brain very high, providing all the information one requires in vascular surgery. Surgeons may wish to explore this possibility. Fig. 1 Top: intra-operative imaging of anterior communicating artery aneurysm clipped via a left transorbital keyhole approach [1] (ICA internal carotid artery; A1, A2 A1 and A2-segments of the anterior cerebral arteries; ON optic nerve). Bottom: Same intra-operative ... On the other hand, we are somewhat worried about the reintroduction of fluorescein for oncological surgery, which our group abandoned many years ago, prior to the development of 5-ALA. The first description was in 1948 by Moore [4], who already commented that “edematous tissue does fluoresce, but to a lesser degree “. Fluorescein enters the tumor via a broken down blood–brain barrier and is unspecific. Wherever there is blood there will be fluorescein, especially in the zone of edema or in any areas of the brain with surgical injury. This is actually well illustrated by the authors’ own images, 1 d and 1 e, and we wonder why these images are not commented on to this end. The image was obtained during surgery for a metastasis and clearly shows that fluorescence marks a much larger area of cortex adjacent to the metastasis in image 1 e after surgical intervention, than in image 1 d, and it appears this is related to surgical trauma. This was our personal experience many years ago. We acknowledge greater ease of application of fluorescein, which needs only be injected, but if researchers would like to again follow this path, much work needs to be done regarding timing, dose, and most importantly, the positive predictive value of fluorescence. The investigation of the positive predictive value of fluorescence should focus on the end of surgery. At this stage, the most unspecific fluorescence will be expected as a consequence of tissue injury and leakage of fluorescein into adjacent tissue. Sincerely, Walter Stummer, Munster

Analysis of Binding Properties Between β-Cyclodextrin Bipyridine-ruthenium Derivative and Vitamins by Their Fluorescence Spectra

This paper presents a research of the binding interaction of a new synthetized β-cyclodextrin bipyridine-ruthenium derivative[β-CD-Ru(bpy)3] with a series of vitamins using fluorescent spectrometry.The performance of fluorescence emission of β-CD-Ru(bpy)3 was excellent due to the existence of the center of bipyridine-ruthenium.Based on the effect of molecular recognition between β-cyclodextrin and guest molecule,the fluorescence quenching occured because of the energy transfer between the β-CD-Ru(bpy)3 and the vitamin when a kind of vitamin was added.According to the quantitative value of fluorescence quenching,the binding constants of the new derivative with respect to various vitamins were determined by Benesi-Hildebrand Equation.The results show that the binding capacities of the vitamins with β-CD-Ru(bpy)3 were in a descending sequence of VB12VK3VCVA.