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In vivo fluorescence methods are efficient tools for studying the distribution of phytoplankton in nature. Different algae species usually have different pigments with different ratios, which results in different fluorescence emission spectra. Based on multiple excitation wavelength fluorescence emission spectra, a discrimination technique is established in this study. The discrimination method, established by multivariate linear regression and weighted least-squares, was used to differentiate the samples cultured in the laboratory and collected from Jiaozhou Bay near Qingdao at the division level. The correctly discriminated samples were ≥ 86% for single algae samples, ≥ 88% for simulatively mixed ones, ≥ 91% for physically mixed ones and 100% for samples collected from Jiaozhou Bay. The result in this research is more definite for the physically mixed samples in the laboratory. The method described here can be employed to monitor the phytoplankton population in the marine environment.

Herein, we report on near-infrared (NIR) fluorescent nanoparticles generated from an emergent class of materials we refer to as a Group of Uniform Materials Based on Organic Salts (GUMBOS). GUMBOS are largely frozen ionic liquids, although the concept is more general and is also easily applied to solid ionic materials with melting points in excess of 100 degrees C. Nanoparticles based on GUMBOS (nanoGUMBOS) derived from a NIR fluorophore are prepared using a reprecipitation method and evaluated for in vivo fluorescence imaging. Due to their uniformity, single-step preparation, and composite nature, nanoGUMBOS help to resolve issues with dye leakage problems innate to alternate cellular stains and unlock a myriad of applications for these materials, highlighting exciting possibilities for multifunctional nanoGUMBOS.

The estimated apparent age (EAA) was estimated by a panel of trained experts, for the individuals in a cohort. Twelve independent clinical, biophysical and biochemical parameters measured on facial skin, have been identified by multiple regression analysis, which influence the EAA of a person of chronological age (CA) (under eye lines, clinically assessed crow’s feet, age spots, clinically evaluated firmness, forehead lines, pores, lip lines, instrumentally evaluated firmness, instrumentally evaluated crow feet, skin texture, in vivo fluorescence related to proliferation and glycation). An algorithm has been devised to obtain the calculated age score (CAS) in a cohort of 452 female volunteers, as $$ {\text{CAS}}(n )= \Upsigma C_{i} P_{i} (n)\quad (i = 1{-}13,n = 1{-}452\,{\text{and}}\,P_{13} = 1) $$ where the coefficients Ci are obtained by minimizing the difference EAA − CAS, and Pi(n) are the experimental values of the i-th parameter for the n-th volunteer. The determination of CAS before and after a specific cosmetic or pharmacological anti-aging treatment can be used to objectively assess the efficacy of the treatment. The comparison of EAA(n) and of CAS(n) with CA(n) allows one to predict the susceptibility of an individual’s face to undergo aging. It has been observed that the biophysical and biochemical parameters play a relevant role in the assessment of the predisposition of skin to undergo accelerated aging.

In vivo fluorescence imaging with near-infrared (NIR) light holds enormous potential for a wide variety of molecular diagnostic and therapeutic applications. Because of its quantitative sensitivity, inherent biological safety, and relative ease of use (i.e., with respect to cost, time, mobility, and its familiarity to a diverse population of investigators), fluorescence-based imaging techniques are being increasingly utilized in small-animal research. Moreover, there is substantial interest in the translation of novel optical techniques into the clinic, where they will prospectively aid in noninvasive and quantitative screening, disease diagnosis, and post-treatment monitoring of patients. Effective deep-tissue fluorescence imaging requires the application of exogenous NIR-emissive contrast agents. Currently, available probes fall into two major categories: organic and inorganic NIR fluorophores (NIRFs). In the studies reviewed herein, we utilized polymersomes (50 nm to 50 microm diameter polymer vesicles) for the incorporation and delivery of large numbers of highly emissive oligo (porphyrin)-based, organic NIRFs.

A 3-chip CCD imaging system has been developed for quantitative in vivo fluorescence imaging. This incorporates a ratiometric algorithm to correct for the effects of tissue optical absorption and scattering, imaging “geometry” and tissue autofluorescence background. The performance was characterized, and the algorithm was validated in tissue-simulating optical phantoms for quantitative measurement of the fluorescent molecule protoporphyrin IX (PpIX). The technical feasibility to use this system for fluorescence-guided surgical resection of malignant brain tumor tissue was assessed in an animal model in which PpIX was induced exogenously in the tumor cells by systemic administration of aminolevulinic acid (ALA).

A growth toxicity assay with mixed cultures of cyanobacteria and algae using in vivo fluorescence is presented. Test organisms (the green alga Pseudokirchneriella subcapitata and the cyanobacterium Aphanothece clathrata) growing alone and in a mixture were exposed to selected chemicals. P. subcapitata featured a higher sensitivity to toxicants in the presence of A. clathrata compared to the single species assay. On the other hand, growth of a cyanobacterium was not affected by the presence or absence of the green alga. The proposed method seems to be suitable for pre-screening studies of toxicants (algistatic agents, herbicides) applied into the aquatic environment and for the assessment of their impact on natural phytoplankton communities.

In situ photosynthetic fluorescence of the zooxanthellate Mediterranean coral Cladocora caespitosa (L.) was measured seasonally on colonies from 5 to 27 m depth using an INF-300 Integrating Natural Fluorometer (Biospherical Instrument Inc.). This oceanographic instrument, used to measure the in vivo phytoplankton chlorophyll a (Chl a) fluorescence, was adapted to record the natural fluorescence of C. caespitosa by SCUBA divers. The resulting curves of natural fluorescence of Chl a vs photosynthetically active radiation (PAR 400-700 nm) showed that: (1) natural fluorescence was limited by light availability in both deep and shallow colonies in all seasons; (2) photosynthesis occurred in C. caespitosa also in winter, when temperature is low and seawater turbidity contributes significantly to PAR attenuation; and (3) the efficiency of the Chl a fluorescence increased from summer to winter. This last finding outlines the winter coupling between zooxanthellae activity and calcification processes and is consistent with the formation of the high density band in the coral skeleton. La fluorescencia fotosintética in situ, de las zooxantelas del coral mediterraneo Cladocora caespitosa (L), se determinó estacionalmente sobre colonias desde 5 a 26 m de profundidad a través de un fluorimetro integrador INF-300 (Biospheral Instrument Inc.). Este instrumento oceanográfico, utilizado para medir la fluorescencia de la clorofilla a del fitoplancton in vivo, se ha adaptado para determinar la fluorescencia natural de C. caespitosa por los buceadores. Las curvas resultantes de la fluorescencia natural de la clorofila a vs la radiación (PAR 400-700 nm) fotosintéticamente activa mostraban que: la fluorescencia natural estaba limitada por la disponibilidad de luz en ambas colonias de profundidad y de aguas poco profundas en todas las estaciones del año, (2) la fotosíntensis producida en C. caespitosa tenia lugar también en invierno, cuando la temperatura es baja y la turbidez del agua contribuyen de forma significativa a la atenuación de PAR, (3) la eficiencia de la fluorescencia de la clorofila a incrementaba desde verano a invierno. Este último hallazgo pone de manifiesto el acoplamiento entre la actividad de las zooxantelas y los procesos de calcificación y es consistente con la formación de la banda de alta densidad en el esqueleto coralino.

In vivo fluorescence imaging uses a sensitive camera to detect fluorescence emission from fluorophores in whole-body living small animals. To overcome the photon attenuation in living tissue, fluorophores with long emission at the near-infrared (NIR) region are generally preferred, including widely used small indocarbocyanine dyes. The list of NIR probes continues to grow with the recent addition of fluorescent organic, inorganic and biological nanoparticles. Recent advances in imaging strategies and reporter techniques for in vivo fluorescence imaging include novel approaches to improve the specificity and affinity of the probes and to modulate and amplify the signal at target sites for enhanced sensitivity. Further emerging developments are aiming to achieve high-resolution, multimodality and lifetime-based in vivo fluorescence imaging.

The objective of lung gene therapy is to reach the respiratory epithelial cells in order to deliver a functional nucleic acid sequence. To improve the synthetic carrier’s efficacy, knowledge of their biodistribution and elimination pathways, as well as cellular barriers faced, depending on the administration route, is necessary. Indeed, the in vivo fate guides the adaptation of their chemical structure and formulation to increase their transfection capacity while maintaining their tolerance. With this goal, lipidic fluorescent probes were synthesized and formulated with cationic lipophosphoramidate KLN47 (KLN: Karine Le Ny). We found that such formulations present constant compaction properties and similar transfection results without inducing additional cytotoxicity. Next, biodistribution profiles of pegylated and unpegylated lipoplexes were compared after systemic injection in mice. Pegylation of complexes led to a prolonged circulation in the bloodstream, whereas their in vivo bioluminescent expression profiles were similar. Moreover, systemic administration of pegylated lipoplexes resulted in a transient liver toxicity. These results indicate that these new fluorescent compounds could be added into lipoplexes in small amounts without perturbing the transfection capacities of the formulations. Such additional properties allow exploration of the in vivo biodistribution profiles of synthetic carriers as well as the expression intensity of the reporter gene.

In vivo fluorescence imaging of β-amyloid (Aβ) plaques in the brain is expected to be used as a new method for detecting Alzheimer's disease (AD). We synthesized novel push–pull dimethylaminothiophenyl (DTM) derivatives and evaluated their utility as in vivo fluorescence imaging probes targeting Aβ plaques. As a result, we found that DTM-2 is a promising fluorescent probe for Aβ plaques in the AD brains.

This paper presents the characteristics of fluorescence for the Caribbean Sea. Hydrographic and fluorometric data were gathered at the upper mixed layer during an oceanographic campaign carried out in the summer of 2001, from the Yucatan Peninsula to Colombian waters. In vivo fluorescence profiles show a conspicuous subsurface chlorophyll maximum located at a depth of around 107 m. These profiles are characteristic of oligotrophic waters such as those of the western Caribbean Sea.

Made available in DSpace on 2015-10-21T20:48:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-03-01. Added 1 bitstream(s) on 2015-10-22T09:52:57Z : No. of bitstreams: 1 S1415-43662015000300273.pdf: 2147575 bytes, checksum: 9fb46d351a7d7824d44c931a826d02be (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Estudos e Pesquisas Agrícolas e Florestais (FEPAF) O florescimento de cianobactérias em águas continentais é um problema mundial que deve ser monitorado pelo potencial risco que representa à saúde humana. O objetivo deste estudo foi mapear a ocorrência de cianobactérias por meio da integração de medidas de fluorescência in vivo do pigmento ficocianina e da análise geoestatística. Os dados fluorimétricos foram coletados em 59 pontos de amostragem georreferenciados no reservatório de Nova Avanhandava, São Paulo, em dezembro de 2011. Analisaram-se, para caracterização do ambiente aquático, parâmetros limnológicos da água além da identificação dos grupos fitoplanctônicos constatando-se a presença de gêneros tóxicos de cianobactérias. Os valores de concentração de ficocianina variaram entre 1 a 10 μg L-1, sinalizando o potencial do método em detectar cianobactérias, mesmo em estágio inicial de florescimento. A análise geoestatística permitiu detectar a anisotropia dos dados de concentração de ficocianina, de modo que o modelo esférico se ajustou melhor para realizar a krigagem ordinária. A validação do modelo resultou em um erro médio quadrático de 0,98, além de permitir modelar a incerteza associada à inferência. Bloom of cyanobacteria in continental waters is a worldwide problem that should be monitored by the potential risk posed to human health. This study aimed to map the occurrence of cyanobacteria through integration of fluorimetric in vivo phycocyanin pigment method and geostatistical analysis. Fluorimetric data were collected from 59 georeferenced sampling points in New Avanhandava reservoir, Sao Paulo, in December 2011. In order to characterize aquatic environment, limnological parameters were analysed. Besides, phytoplankton groups identification were performed, noting the presence of toxic cyanobacterial genera. Values of phycocyanin concentration ranged between 1 to 10 mg L-1, indicating the potential of the method for cyanobacteria detection, even in early stages of bloom. Geostatistical analysis allowed detecting phycocyanin concentration anisotropy, which adjusted better in spherical model to perform ordinary kriging. Model validation resulted in Root Mean Square equal to 0.98, besides allows modeling the inference uncertainty. DEAM UFMT, Uberaba, MG, Brazil DCARTOG Unesp, Presidente Prudente, SP, Brazil DEST Unesp, Presidente Prudente, SP, Brazil Faculdade de Ciências e Tecnologia de Presidente Prudente, Departamento de Cartografia, Presidente Prudente, SP Faculdade de Ciências e Tecnologia de Presidente Prudente, Departamento de Estatística, Presidente Prudente, SP

Microscopic imaging techniques to visualize cellular behaviors in their natural environment play a pivotal role in biomedical research. Here, we review how recent technical advances in intravital microscopy have enabled unprecedented access to cellular physiology in various organs of mice in normal and diseased states.

The near-infrared fluorescence from AY-27 orthotopic rat bladder tumors after intravesical instillation of a 2-deoxy-D-glucose optical-probe was imaged in vivo from bisected bladder. Bladder specific fluorescence was compared against controls and tumors without the optical-probe.

Compared to imaging in the visible and near-infrared regions below 900 nm, imaging in the second near-infrared window (NIR-II, 1000-1700 nm) is a promising method for deep-tissue high-resolution optical imaging in vivo mainly due to the reduced scattering of photons traversing through biological tissues. Herein, semiconducting single-walled carbon nanotubes with large diameters were used for in vivo fluorescence imaging in the long-wavelength NIR region (1500-1700 nm, NIR-IIb). With this imaging agent, 3-4 um wide capillary blood vessels at a depth of about 3 mm could be resolved. Meanwhile, the blood-flow speeds in multiple individual vessels could be mapped simultaneously. Furthermore, NIR-IIb tumor imaging of a live mouse was explored. NIR-IIb imaging can be generalized to a wide range of fluorophores emitting at up to 1700 nm for high-performance in vivo optical imaging., Comment: 29 pages, 5 main figures and 11 supplementary figures

Compact polymerized polydiacetylene-micelles with “stealth” zwitterionic surface coating were assembled and tested in a murine xenograft model of breast cancer. In vivo fluorescence imaging indicated accumulation in the tumor area and histological studies revealed predominant uptake of the micelles at the margins of the tumor, thereby allowing the delineation of its volume.

Four emulsion-filled gelatin gels varying in fat content (5 and 15%) and type of emulsifier (whey protein isolate: fat droplets bound to matrix; Tween 20: fat droplets unbound to matrix) were studied. We investigated (1) the formation and clearance dynamics of fat deposition on the tongue using in vivo fluorescence during oral processing; (2) influence of fat droplet characteristics on fat deposition on tongue and fatty mouthfeel; and (3) effect of follow-up consumption (water or gelatin gel) on the removal of fat deposition on the tongue. We conclude that fat fraction deposited on tongue and fatty perception increased with increasing mastication time, and decreased after expectoration with increasing clearance time. Fat fraction deposited on tongue and fatty perception are higher in gels with unbound droplets compared to bound droplets, as well as in gels with 15% fat compared to 5% fat. Water removed deposited fat from the tongue faster than gelatin gel.

Fluorescence imaging using fluorescent probes has demonstrated long-term stability and brightness suitable forin vivodeep-tissue imaging, but it also allows intense background fluorescence associated with food in the near-infrared (IR) range. We investigated effects of changing rodent diet on food autofluorescence, in the presence of quantum dots-conjugated magnetic nanospheres (QD-MNSs). Replacement of a regular rodent diet with a purified diet has great improvement in removing autofluorescence in the near-infrared range ideal forin vivofluorescence imaging. By feeding a purified diet for eliminating ingredients impairing desirable fluorescence signals in the near-IR range, food autofluorescence was clearly eliminated and fluorescence probes, QD-MNSs, introduced by i.v. injection were effectively traced in a mouse by a distinctive signal-to-noise ratio.

"This paper presents the characteristics of fluorescence for the Caribbean Sea. Hydrographic and fluorometric data were gathered at the upper mixed layer during an oceanographic campaign carried out in the summer of 2001, from the Yucatan Peninsula to Colombian waters. In vivo fluorescence profiles show a conspicuous subsurface chlorophyll maximum located at a depth of around 107 m. These profiles are characteristic of oligotrophic waters such as those of the western Caribbean Sea."

A fluorescence fiber optic microendoscope is integrated into a whole-animal imaging system to enhance the detection sensitivity for fluorescent bacteria in lung infections of live mice.

Quantitative in vivo measurements are essential for developing a predictive understanding of cellular behavior. Here we present a technique that converts observed fluorescence intensities into numbers of molecules. By transiently expressing a fluorescently tagged protein and then following its dilution during growth and division, we observe asymmetric partitioning of fluorescence between daughter cells at each division. Such partition asymmetries are set by the actual numbers of proteins present, and thus provide a means to quantify fluorescence levels. We present a Bayesian algorithm that infers from such data both the fluorescence conversion factor and an estimate of the measurement error. Our algorithm works for arbitrarily sized data sets and handles consistently any missing measurements. We verify the algorithm with extensive simulation and demonstrate its application to experimental data from Escherichia coli. Our technique should provide a quantitative internal calibration to systems biology studies of both synthetic and endogenous cellular networks.

Noninvasive in vivo imaging is a rapidly growing field with applications in basic biology, drug discovery and clinical medicine. Because of the high cost of magnetic resonance (MR)- and computed tomography (CT)-based systems, a great deal of effort has gone into developing optical imaging methods, which offer, in some modalities, the promise of high spatial resolution and the ability to detect multiple markers simultaneously However, the ability to image and quantitate fluorescently labeled tumors and other fluorescently labeled markers in vivo has generally been limited by the autofluorescence of the tissue, which reduces the sensitivity of detection and accuracy of quantitation of the labeled target. Multispectral imaging methodology, which spectrally characterizes and computationally eliminates autofluorescence, enhances signal-to-background dramatically, revealing otherwise invisible labeled targets. Signal-to-noise considerations can guide the choice of appropriate sensors for fluorescence-based imaging, which generally does not benefit from the use of highly cooled (and expensive) cameras. Effective use of spectral tools to remove autofluorescence signal requires accurate spectra of the individual components. Using manual and automated algorithms to generate these spectra, it is possible to detect as many as three fluorescent protein-labeled tumors and two separate autofluorescent signals in a single subject.

Summary Background Throughout life facial skin is exposed to a variety of adverse environmental conditions and is constantly required to repair itself. The rate of epidermal cell proliferation is indicative of the skin's repair rate and can be monitored noninvasively in vivo using skin intrinsic fluorescence markers. Objectives The goal of the present study was to assess the effects of ageing, geographical region, ethnic origin and season on the ability of facial skin to repair itself in the presence of chronic environmental insults using in vivo fluorescence spectroscopy. Methods Skin fluorescence emission was measured on the cheeks of 522 individuals in winter and repeated in summer in five different geographical locations in the Asia-Pacific region. Fluorescence emission was also measured from 80 caucasians of fair complexion in the United States (New Jersey area) on the face and on a relatively protected area (upper inner arm). The age range of the participants was 14–75 years. Results We found that epidermal proliferation rates decrease monotonically with age, while the fluorescence of collagen and elastin cross-links increases with age indicating accumulation of advanced glycation end-products. These trends were independent of geographical region, ethnic origin and season of measurement. Epidermal proliferation rates of facial skin were higher than those of unexposed sites; they may be 10 times higher in younger (second decade) than in older (seventh decade) individuals, and they decrease with age at rates 10 times faster compared with those of unexposed sites. Conclusions This is the first time that epidermal proliferation and its dependence on ageing have been measured noninvasively on the human face. The higher tryptophan fluorescence values on the face vs. the protected site are indicative of accelerated rates of epidermal proliferation in the presence of chronic environmental insults. The repair potential of facial skin, i.e. its ability to maintain high proliferation rates, is maximal in younger populations and gradually decreases with age.

Taking continuous spatiotemporal in situ measurements with multi-probes in fast-flowing waters/rivers can be problematic because the sensors may be damaged by high shear forces and flotsam. To protect the multi-probe and to enable easy access for the maintenance and calibration of the sensors, a special multi-probe holder fixed in a hydrographic slot was developed. The validation of the probe system revealed a “memory effect” at short time scales (< 10 s) within sharp gradients caused by the overflow container of the multi-probe rack keeping the sensors submerged in the sample water. Continuously recorded data (conductivity, temperature, pH, oxygen concentration and saturation, as well as in vivo fluorescence of chlorophyll-a) from a research cruise on board the RV ALBIS along the river Elbe (river km 309) and entering the river Saale are presented. This river stretch upstream of the city of Magdeburg to the mouth of the Saale tributary was found to have a complex physicochemical character, which is attributable to the long mixing process of water from the river Saale and the river Elbe. Kontinuierliche Multisondenmessungen in schnell stromendem Wasser mittels eines hydrographischen Schachts Kontinuierliche raumliche und zeitliche In-situ-Messungen mit Multisonden in schnell stromenden Gewassern/Flussen konnen problematisch sein, da hohe Scherkrafte und Treibgut die Sensoren beschadigen konnten. Um diese zerstorenden Effekte auf die Multisonde zu vermeiden und einen einfachen Zugang fur die Kalibrierung und Wartung der Sensoren zu erhalten, wurde eine spezielle Multisonden-Halterung, die in einem hydrographischen Schacht fixiert wird, entwickelt. Die Validierung des Sondensystems ergab fur kurze Zeitskalen (< 10 s) innerhalb starker Gradienten einen „Memory-Effekt”, der durch den Uberlaufbehalter des Multisondengestells, der die Sensoren im Probenwasser halt, hervorgerufen wird. Es werden kontinuierlich aufgenommene Daten (Leitfahigkeit, Temperatur, pH-Wert, Sauerstoffkonzentration und -sattigung sowie In-vivo-Fluoreszenz des Chlorophyll-a) von einer Untersuchungsfahrt mit dem Forschungsschiff FS „ALBIS” entlang der Elbe (Flusskilometer 309) bis in die Saale vorgestellt. Fur den Flussabschnitt oberhalb der Stadt Magdeburg bis zur Mundung des Nebenflusses Saale konnte eine komplexe physikochemische Situation nachgewiesen werden, die durch einen langen Vermischungsprozess von Elbe- und Saalewasser verursacht wird.

A continuous time series of high-resolution in vivo fluorescence measurements in coastal waters of the eastern English Channel over 4 tidal cycles investigated the potential influence of different turbulence intensities and advective tidal processes on small-scale phytoplankton patchi- ness. Although small-scale phytoplankton patchiness decreased with increasing turbulence intensity, phytoplankton distributions were never fully homogenised, and were more patchy during ebb than flood tides at turbulence intensities ranging from 10 -7 to 10 -4 m 2 s -3 . A combination of biologically and physically driven patchiness is suggested to be the cause of the observed patterns.

The laser-induced fluorescence (LIF) was tested as a means to detect the effects of a pink-pigmented facultative methylotrophic bacteria (Methylobacterium) in blue agave plants, and compared with conventional techniques of leaf tissue analysis. A He–Ne laser emitting at 632.8 nm was used as the excitation source. In vivo fluorescence emission spectra were recorded in the 660–790 nm range. Fluorescence maxima were at 690 and 740 nm. The inoculated plants showed a significant change in fluorescence as compared to that of non-inoculated plants. The ratios of fluorescence intensities F690/F740 were calculated for all treatments. A comparison between conventional techniques and this non-invasive method is presented. The results of this work showed that the beneficial effects of PPFM bacteria on agave plants are detectable by LIF.

The Saimaa lake complex (4460 km 2 ) is a mosaic of interconnected basins draining into the Gulf of Finland via Lake Ladoga. Limnologically, most of the basins are dysmesotrophic or oligotrophic, while some areas are markedly affected by nutrient loading. Aquatic research has been conducted in the Lake Saimaa area with the 27-metre research vessel R/V Muikku since 1989, and the laboratory and research facilities on the vessel have been built up and enhanced over this time to include temporally and spatially reliable automatic measuring systems such as CTD (ConductivityTemperatureDepth) probes and a continuous-flow in vivo fluorometer. This paper uses linear regression to compare vertical CTD measurements with standardised laboratory analyses of water temperature, O 2 concentration, conductivity and pH in different basins of the Lake Saimaa complex from data sets collected on board R/V Muikku in 2000-2001, and tests in vivo automatic fluorometer measurements of filtered and unfiltered discrete water samples from the Haukivesi basin of Lake Saimaa against in vitro chlorophyll-a concentrations. All the linear regressions showed a significant overall consistency between the CTD and fluorometer results and the laboratory analyses, but the pH comparisons showed some instability between methods. Clear spatial and vertical variations in conductivity and oxygen concentrations were apparent in the CTD results for three basins (Lakes Pyhaselka. Haukivesi and Etela-Saimaa), and there was also a significant linear relationship of unfiltered and filtered in vivo fluorescence to in vitro chlorophyll-a concentrations. The unfiltered fluorometer measurements were nevertheless markedly higher than those obtained from filtered water samples. Thus humic and other dissolved substances in lake water may be said to yield enhanced fluorometer readings independent of the chlorophyll-a concentrations, as has been noted earlier in similar studies.

In vivo fluorescence imaging has been a popular functional imaging modality in preclinical imaging. Near infrared probes used in fluorescence molecular tomography (FMT) are designed to localize in the targeted tissues, hence sparse solution to the FMT image reconstruction problem is preferred. Nonconvex regularization methods are reported to enhance sparsity in the fields of statistical learning, compressed sensing etc. We investigated such regularization methods in FMT for small animal imaging with numerical simulations and phantom experiments. We adopted a majorization-minimization algorithm for the iterative reconstruction process and compared the reconstructed images using our proposed nonconvex regularizations with those using the well known L1regularization. We found that the proposed nonconvex methods outperform L1regularization in accurately recovering sparse targets in FMT. © 2014 Institute of Physics and Engineering in Medicine.

© 2014 by the author. In vivo fluorescence molecular tomography (FMT) has been a popular functional imaging modality in research labs in the past two decades. One of the major difficulties of FMT lies in the ill-posed and ill-conditioned nature of the inverse problem in reconstructing the distribution of fluorophores inside objects. The popular regularization methods based on L2, L1and total variation (TV) norms have been applied in FMT reconstructions. The non-convex Lq(0 < q < 1) semi-norm and Log function have also been studied recently. In this paper, we adopt a uniform optimization transfer framework for these regularization methods in FMT and compare their individual, as well as the combined effects on both small, localized targets, such as tumors in the early stage, and large targets, such as liver. Numerical simulation studies and phantom experiments have been carried out, and we found that Lqwith q near 1/2 performs the best in reconstructing small targets, while joint L2and Log performs the best for large targets.

This review summarizes progress in the field of near-infrared (NIR) fluorophores achieved during the last decade from the viewpoint of chemistry. Those compounds are of wide interest in bioanalysis and bioimaging, such as in vivo fluorescence imaging. Particular focus is placed on the recent developments of BODIPY and rhodamine derivatives, which belong to the most evolved NIR fluorophores. The data compiled in this review, including the chemical structures and optical properties of all compounds introduced, provide readers of this article with an overview of the field of NIR fluorophores.

To monitor the biodistribution of IgG1 aggregates upon subcutaneous (SC) and intravenous (IV) administration in mice and measure their propensity to stimulate an early immune response.A human mAb (IgG1) was fluorescently labeled, aggregated by agitation stress and injected in SKH1 mice through SC and IV routes. The biodistribution of monomeric and aggregated formulations was monitored over 47 days by fluorescence imaging and the early immune response was measured by quantifying the level of relevant cytokines in serum using a Bio-plex assay.The aggregates remained at the SC injection site for a longer time than monomers but after entry into the systemic circulation disappeared faster than monomers. Upon IV administration, both monomers and aggregates spread rapidly throughout the circulation, and a strong accumulation in the liver was observed for both species. Subsequent removal from the circulation was faster for aggregates than monomers. No accumulation in lymph nodes was observed after SC or IV administration. Administration of monomers and aggregates induced similar cytokine levels, but SC injection resulted in higher cytokine levels than IV administration.These results show differences in biodistribution and residence time between IgG1 aggregates and monomers. The long residence time of aggregates at the SC injection site, in conjunction with elevated cytokine levels, may contribute to an enhanced immunogenicity risk of SC injected aggregates compared to that of monomers.

In this study we have shown that in-vivo fluorescence lifetime imaging can be used for monitoring the efficacy of targeted therapy with 17-DMAG on HER2 positive tumors.

One of the most versatile imaging methods is fluorescence imaging. Along with its sensitivity, the number of targeting platforms possible and the number of different fluorophores in combination with available innovative probes have contributed to the popularity of this technique when noninvasive applications have been the aim. Two-dimensional (2D) in vivo fluorescence imaging has played a steady role in preclinical small animal imaging for the last 20 years and has only recently been challenged by 3D fluorescence imaging.

We demonstrate the in vivo imaging of a mouse tumor using fluorescence optical diffusion tomography and the extraction of kinetic information from a compartment model, yielding the first folate drug release kinetics inside cancer cells.

We present theoretical and experimental methods for in vivo fluorescence lifetime multiplexing and validate the approach using implanted and organ targeted fluorophores in mice.

The goal is to develop an in situ gel system comprising anionic liposomes (AL) containing bleomycin A6 (BLM A6) dispersed within the thermosensitive in situ gel for sustained release. The results indicated that the gelation temperature decreased due to AL within gel. Similarly, viscosity and mechanical parameters, such as gel strength for gel, could be enhanced by inducing lipid material with negative charge (phosphatidylglycerol) at 37 °C, which provided against corrosion at physiological condition. The in vitro release experiments performed with a dialysis method revealed that in situ gel with AL exhibited the longer drug-release period compared to that with or without nonionic liposomes. An in vivo fluorescence imaging study suggested that the gel with AL loading FITC-BLM A6 stayed in administration site at least for five days. A thermosensitive in situ gel with anionic liposome was a promising carrier for hydrophilic BLM A6, to be used in parenteral delivery system for anti-tumor treatment.

Microbial ectoenzyme activities in aquatic environments are important agents of poly- mer hydrolysis and indicators of the state of microbial carbon, nitrogen, or phosphorus nutrition. However, like most other biochemical and molecular measurements, ectoenzyme activities have been limited to discrete water samples. We have developed a continuous underway method for measuring microbial enzyme activities using high-sensitivity fluorescent substrates. The system we developed consisted of a peristaltic proportioning pump, a temperature-controlled water bath, and a spectrofluorometer interfaced to a portable computer which controlled the fluorometer and logged the data. This method has been applied to alkaline phosphatase and to leucine aminopeptidase measurements in the surface waters of the Mississippi River plume and the Louisiana shelf, and alka- line phosphatase measurements in the surface waters of a Texas lake. This method will enable us to map the surface distributions of microbial enzyme activities on scales comparable to temperature, salinity, in vivo fluorescence, and other parameters which can be continuously mapped from a research ship while underway.

http://www.elsevier.com/locate/issn/09247963 The results of field studies of phytoplankton and dissolved organic matter DOM.in the Gulf of Riga in August-September 1993, June 1994 and April 1995 are presented. Actively excited fluorescence in UV- and visible spectral regions was used to investigate spatial distributions of DOM, Chl a, carotenoids and phycoerythrin in surface water. The fluorescent data were collected by means of laser remote sensing spectrometer LIDAR., spectrofluorometers in underway flow-through mode and in the measurements of the water samples. Pronounced variable spatial structures of phytoplankton were observed in spring 1995 and late summer 1993, while in early summer 1994 the pigment distribution was rather homogeneous. The spatial modulation of high-resolution profiles of phytoplankton with the period 3.5-5 km was detected across the gulf in all seasons probably caused by variability of hydrophysical conditions. A negative correlation of DOM concentration in surface waters and salinity was revealed in August-September 1993 and June 1994.

Keywords: Photomedicine group Reference LPAS-ARTICLE-1998-003View record in Web of Science Record created on 2007-07-20, modified on 2016-08-08

Background The photosensitizer, NPe6, was injected into mice previously transplanted with fibrosarcoma to study changes in ultrasmall lesions at an early stage of neoplasm.

Endoscopic probes have been incorporated into a fluorescent imaging system for the remote quantitation of tissue selective markers. Resolution at the level of 114 line pairs/mm allows visualization of regions that are approximately 6 mm wide. Tissue selective markers, based on polyazamacrocyclic chelates of terbium increase contrast and can be quantified in tissues at the sub-picomole level. Minimally invasive in vivo fluorescence imaging is demonstrated. The potential for application of the system to disease diagnosis and bone graft morphology quantitation is discussed.

Non-invasive fluorescence imaging has the potential to provide in vivo diagnostic information for many clinical specialities. Techniques have been developed over the years for simple ocular observations following UV excitation to sophisticated spectroscopic imaging using advanced equipment. Much of the impetus for research on fluorescence imaging for tissue diagnostics has come from parallel developments in photodynamic therapy of malignant lesions with fluorescent photosensitizers. However, the fluorescence of endogenous molecules (tissue autofluorescence) also plays an important role in most applications. In this paper, the possibilities of imaging tissues using fluorescence spectroscopy as a mean of tissue characterization are discussed. The various imaging techniques for extracting diagnostic information suggested in the literature are reviewed. The development of exogenous fluorophores for this purpose is also presented. Finally, the present status of clinical evaluation and future directions are discussed.

The fluorescence kinetics of protoporphyrin IX (PPIX) following intravesical instillation of 5-aminolaevulinic acid (5-ALA) have been studied in vivo in a rat bladder tumour model. 5-ALA dissolved in NaHCO3 was intravesically instilled for 60 min in tumour-bearing and normal bladders of Wistar rats. The fluorescence was excited with the violet lines of a Kr(+)-laser and recorded in vivo by means of a fibre coupled optical multichannel analyser. The fluorescence emission bands of PPIX at lambda = 636 nm and lambda = 708 nm were detected in normal and tumorous urothelium after only 30 min. The maximum fluorescence intensity was obtained in tumorous and normal urothelium 3-4 h after instillation. The ratio of the fluorescence intensity in tumorous to normal urothelium decreased continuously from four to about two during the time range of 6 h. PPIX fluorescence following 5-ALA instillation could also be observed in kidney and liver. Fluorescence from further porphyrin species with emission bands at lambda = 617 nm and lambda = 682 nm was detected in the bladder, indicating an efflux of hydrophilic porphyrins from the hepatic pathway.

Bone lead content of the mid-tibia was measured by in vivo fluorescence excitation in 90 females and 59 males aged between 6 and 81. The cross-sectionally derived rate of increase of tibia lead content was 0.24 +/- 0.03 microgram [g mineral]-1 yr-1. In 93 adult women, the corresponding rate of increase for calcaneus lead content was 0.12 +/- 0.11 microgram [g mineral]-1 yr-1. Comparison with European values show that, in Canada, the rates of lead accumulation are greater than those found in N. Sweden and Finland, similar to those of S. Sweden and less than values measured in England.