Hubert van den Bergh

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We describe a new fluorescence imaging device for clin. cancer photodetection in hollow organs in which the tumor/normal tissue contrast is derived from the fluorescence lifetime of endogenous or exogenous fluorochromes. This fluorescence lifetime contrast ...

The Jungfraujoch Research Station (46.55 degrees N, 7.98 degrees E, 3580 m above sea level) for decades has contributed in a significant manner to the systematic observation of the Earth's atmosphere both with in situ measurements and with trace gas column detection. We report on the development of a lidar system that improves the measurement potential of highly resolved atmospheric parameters in both time and space, with the goal of achieving long-term monitoring of atmospheric aerosol optical properties a

The early detection and localization of bronchial cancer remains a challenging task. Autofluorescence bronchoscopy is emerging as a useful diagnostic tool with improved sensitivity and specificity. Evidence exists that the native fluorescence or autofluorescence of bronchial tissues changes when they turn dysplastic or to carcinoma in situ (CIS). Early lesions in the bronchi tend to show a decrease in autofluorescence in the green region of the spectrum when excited with violet light and a relative increase

To understand the effects of substitution patterns on photosensitizing the ability of boron dipyrromethene (BODIPY), two structural variations that either investigate the effectiveness of various iodinated derivatives to maximize the "heavy atom effect" or ...

An instrumentation is being developed to draw a fluorescence life-time map of tissue endoscopically. This fluorescence life-time of an endogenous or exogenous fluorochrome gives information about the physico-chemical environment which is thought to vary between normal and diseased tissue. The excitation light from a cw laser is modulated in amplitude at high frequencies by an electro-optic modulator and delivered to the endoscopic site through an optical fiber. The image of the tissue is spectrally split in

Background: In specific conditions, photodynamic therapy (PDT) can enhance the distribution of macromolecules across the endothelial barrier in solid tumors. It was recently postulated that tumor neovessels were more responsive to PDT than the normal vascu ...

The angiogenesis inhibitor sunitinib is a tyrosine kinase inhibitor that acts mainly on the VEGF and PDGF pathways. We have previously shown that sunitinib is sequestered in the lysosomes of exposed tumor and endothelial cells. This phenomenon is part of t ...

Visudyne®-mediated photodynamic therapy (PDT) at low drug/light conditions has shown to selectively enhance the uptake of liposomal doxorubicin in subpleural localized sarcoma tumors grown on rodent lungs without causing morphological alterations of the lu ...

The fluorescence lifetime of living tissues is, in certain cases, related to their pathol. state and is therefore of interest for cancer detection. Measuring fluorescence lifetime in vivo during an endoscopic examn. has thus been a challenging objective fo ...

The objective of this study was to evaluate the ability of meso-tetra(hydroxyphenyl)chlorin (m-THPC) encapsulated into liposomal formulations to occlude neovascularization. Two m-THPC formulations including conventional or plain liposomes (Foslip) based on ...

An optical method based on fluorescence spectroscopy was developed for in-situ non-destructive, real time, org. pollutant detection and quantification in soil. Optical fiber-based light-induced fluorescence probes allowing in-situ specific chem. detection were constructed. Pyranine was chosen as a model fluorescent polycyclic arom. hydrocarbon (PAH). The effect of sand particles on fluorescence measurements was established: the fluorescence intensity in water-satd. sand was 8 times lower than in aq. solns.,

In vivo spectrofluorometric analysis during photodynamic therapy (PDT) is a tool to obtain information about fluorophore bleaching kinetics in tissue. Using a cylindrical esophageal light distributor for PDT with an integrated sensing fiber, together with a fluorescence detection setup, we can obtain tissue fluorescence spectra endoscopically in a clinical environment. This study was performed on patients with early squamous cell carcinomas in the esophagus. Patients were injected intravenously with 0.15 mg

Background. To optimize photodynamic therapy (PDT) and photodetection of cancer, two important variables that must be considered are the uptake of the dye and the dye contrast between normal and neoplastic tissue after injection. Methods. To study these va ...

A common method to induce enhanced short-term endogenous porphyrin synthesis and accumulation in cell is the topical, systemic application of 5-aminolevulinic acid or one of its derivatives. This circumvents the intravenous administration of photosensitizers normally used for photodynamic therapy (PDT) of fluorescence photodetection. However, in the majority of potential medical indications, optimal conditions with respect to the porphyrin precursor or its pharmaceutical formulation have not yet been found.

An argon laser is used to induce Laser Chem. Vapor Deposition (LCVD) of platinum using platinum bihexafluoroacetylacetonate as precursor. The process can be photolytic or pyrolytic depending on the laser power used. These processes are studied by recording the laser light transmitted through deposit and substrate. Photolytic deposition takes place either in the adsorbed phase or in the gaseous phase depending on the temp. induced by radiation absorption. The induced-temp. calcn. using a model developed by t

NOVELTY - The device has a carrier (1) which is provided with micro-cavity (2) for containing medium in direct contact with the object on which the medium is to be applied. Other carrier is provided with ring to protect the medium from environment when the ...

Head and neck (H&N) cancer patients have a high incidence of second primary tumors in the tracheobronchial tree. Diagnostic autofluorescence endoscopy (DAFE) has shown promising results in the detection of early neoplastic and pre-neoplastic changes in the bronchi. We have investigated the medical impact of DAFE in a population of H&N cancer patients. The bronchoscopies were performed using a modified commercially available DAFE system, allowing both white light (WL) and autofluorescence (AF) bronchoscopy.

Measuring tissue oxygenation in vivo is of interest in fundamental biological as well as medical applications. One minimally invasive approach to assess the oxygen partial pressure in tissue (pO(2)) is to measure the oxygen-dependent luminescence lifetime ...

Numerical simulations compared with field measurements are used to explain the effect of sea breezes on photochemical smog episodes in Athens during the Mediterranean Campaign of Photochemical Tracers on 12-14 September 1994. The numerical simulations, performed using a nonhydrostatic vorticity mesoscale model coupled to the Lurmann-Carter-Coyner photochemical module, are compared with ground-based lidar and aircraft measurements. The current analysis shows that the three selected days include the two main

The chicken embryo's chorioallantoic membrane (CAM) is widely used as an in vivo model to study the vascular effects induced by agents administrated topically or intravenously. Hence, in the vascular plexus of this respiratory membrane, angiogenic and anti-angiogenic agents, as well as phototoxic effects have been studied. The main goal of this study was to characterize the capillary network of the CAM after topical administration of dimethyl sulfoxid (DMSO), a frequently used solvent of lipophylic drugs, i

Hubert van den Bergh

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Frequency-domain fluorescence lifetime imaging for endoscopic clinical cancer photodetection: Apparatus design and preliminary results

Development of a multiwavelength aerosol and water-vapor lidar at the Jungfraujoch Alpine Station (3580 m above sea level) in Switzerland

Optimization of the spectral design used to detect early carcinoma in the human tracheo-bronchial tree by autofluorescence imaging

In vitro and in vivo photocytotoxicity of boron dipyrromethene derivatives for photodynamic therapy

Endoscopic tissue fluorescence life-time imaging by frequency domain light-induced fluorescence

Photodynamic Therapy Selectively Enhances Liposomal Doxorubicin Uptake in Sarcoma Tumors to Rodent Lungs

Photoactivation of lysosomally sequestered sunitinib after angiostatic treatment causes vascular occlusion and enhances tumor growth inhibition

Photodynamic induced uptake of liposomal doxorubicin to rat lung tumors parallels tumor vascular density

Instrumentation for real-time fluorescence lifetime imaging in endoscopy

Photothrombic activity of m-THPC-loaded liposomal formulations: pre-clinical assessment on chick chorioallantoic membrane model

Development of an optical fiber fluorescence setup for in-situ PAHs detection in porous media. Application to pyranine transport in sand columns

In-vivo measurement of fluorescence bleaching of meso-tetra hydroxy phenyl chlorin (mTHPC) in the esophagus and the oral cavity

Clinical pharmacokinetic studies of photofrin by fluorescence spectroscopy in the oral cavity, the esophagus, and the bronchi

Routine experimental system for defining conditions used in photodynamic therapy and fluorescence photodetection of (non-) neoplastic epithelia

Temperature effect on the photolytic deposition of platinum ohmic contacts and Schottky diodes

Device for application of medium to human tissue or animal body such as eye, has carrier which is provided with micro-cavity for containing medium in direct contact with object on which medium is to be applied

Detection of early bronchial cancer by autofluorescence: Results in patients with H&N cancer

In vivo measurement of tissue oxygenation by time-resolved luminescence spectroscopy: advantageous properties of dichlorotris(1, 10-phenanthroline)-ruthenium(II) hydrate

Effect of sea breeze on air pollution in the greater Athens area. Part I: Numerical simulations and field observations

Vascular effects induced by anti-VEGF agents in the CAM model: Effect of the DMSO