Publications by authors named "Franco Fusi"

23 Publications

  • Page 1 of 1

Validation of a secondary dose check tool against Monte Carlo and analytical clinical dose calculation algorithms in VMAT.

J Appl Clin Med Phys 2021 Mar 18. Epub 2021 Mar 18.

Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.

Purpose: Patient-specific quality assurance (QA) is very important in radiotherapy, especially for patients with highly conformed treatment plans like VMAT plans. Traditional QA protocols for these plans are time-consuming reducing considerably the time available for patient treatments. In this work, a new MC-based secondary dose check software (SciMoCa) is evaluated and benchmarked against well-established TPS (Monaco and Pinnacle ) by means of treatment plans and dose measurements.

Methods: Fifty VMAT plans have been computed using same calculation parameters with SciMoCa and the two primary TPSs. Plans were validated with measurements performed with a 3D diode detector (ArcCHECK) by translating patient plans to phantom geometry. Calculation accuracy was assessed by measuring point dose differences and gamma passing rates (GPR) from a 3D gamma analysis with 3%-2 mm criteria. Comparison between SciMoCa and primary TPS calculations was made using the same estimators and using both patient and phantom geometry plans.

Results: TPS and SciMoCa calculations were found to be in very good agreement with validation measurements with average point dose differences of 0.7 ± 1.7% and -0.2 ± 1.6% for SciMoCa and two TPSs, respectively. Comparison between SciMoCa calculations and the two primary TPS plans did not show any statistically significant difference with average point dose differences compatible with zero within error for both patient and phantom geometry plans and GPR (98.0 ± 3.0% and 99.0 ± 3.0% respectively) well in excess of the typical clinical tolerance threshold.

Conclusion: This work presents results obtained with a significantly larger sample than other similar analyses and, to the authors' knowledge, compares SciMoCa with a MC-based TPS for the first time. Results show that a MC-based secondary patient-specific QA is a clinically viable, reliable, and promising technique, that potentially allows significant time saving that can be used for patient treatment and a per-plan basis QA that effectively complements traditional commissioning and calibration protocols.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/acm2.13209DOI Listing
March 2021

Crosslinked Hyaluronic Acid with Liposomes and Crocin Confers Cytoprotection in an Experimental Model of Dry Eye.

Molecules 2021 Feb 6;26(4). Epub 2021 Feb 6.

Department of Medicine and Health Sciences "V. Tiberio", University of Molise, 86100 Campobasso, Italy.

Dry eye disease (DED) is a multifactorial condition caused by tear deficiency and accompanied by ocular surface damage. Recent data support a key role of oxidative and inflammatory processes in the pathogenesis of DED. Hyaluronic acid (HA) is widely used in artificial tears to treat DED by improving ocular hydration and reducing surface friction. Crocin (Cr), the main constituent of saffron, is a renowned compound that exhibits potent antioxidant and anti-inflammatory effects. The present study was undertaken to assess the viscosity and muco-adhesiveness of a photoactivated formulation with crosslinked HA (cHA), Cr, and liposomes (cHA-Cr-L). Our aim was also to evaluate whether cHA-Cr-L may exert cytoprotective effects against oxidative and inflammatory processes in human corneal epithelial cells (HCECs). Viscosity was measured using a rotational rheometer, and then the muco-adhesiveness was evaluated. Under hyperosmolarity (450 mOsm), the HCECs were treated with cHA-Cr-L. Interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα) were quantified by quantitative real-time polymerase chain reaction (RT-qPCR). The levels of reactive oxygen species (ROS) were measured using the DCF assay. The combined action of cHA-Cr-L produced a higher viscosity and muco-adhesiveness compared to the control. The anti-inflammatory effect of cHA-Cr-L was achieved through a significant reduction of IL-1β and TNFα ( < 0.001). The results also showed that cHA-Cr-L reduces ROS production under conditions of hyperosmolarity ( < 0.001). We conclude that cHA-Cr-L has potential as a therapeutic agent in DED, which should be further investigated.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/molecules26040849DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7915152PMC
February 2021

Shedding light on the restart.

Phys Med 2020 09 5;77:18-20. Epub 2020 Aug 5.

Medical Physics Unit, Department of Experimental and Clinical Biomedical Sciences "Mario Serio" Viale G. Pieraccini 6, I-50139 Florence, University of Florence, Italy. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmp.2020.07.018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7403859PMC
September 2020

Comprehensive Analysis of Radiomic Datasets by RadAR.

Cancer Res 2020 08 15;80(15):3170-3174. Epub 2020 Jun 15.

Department of Experimental and Clinical Biomedical Sciences, "Mario Serio", University of Florence, Florence, Italy.

Quantitative analysis of biomedical images, referred to as radiomics, is emerging as a promising approach to facilitate clinical decisions and improve patient stratification. The typical radiomic workflow includes image acquisition, segmentation, feature extraction, and analysis of high-dimensional datasets. While procedures for primary radiomic analyses have been established in recent years, processing the resulting radiomic datasets remains a challenge due to the lack of specific tools for doing so. Here we present RadAR (Radiomics Analysis with R), a new software to perform comprehensive analysis of radiomic features. RadAR allows users to process radiomic datasets in their entirety, from data import to feature processing and visualization, and implements multiple statistical methods for analysis of these data. We used RadAR to analyze the radiomic profiles of more than 850 patients with cancer from publicly available datasets and showed that it was able to recapitulate expected results. These results demonstrate RadAR as a reliable and valuable tool for the radiomics community. SIGNIFICANCE: A new computational tool performs comprehensive analysis of high-dimensional radiomic datasets, recapitulating expected results in the analysis of radiomic profiles of >850 patients with cancer from independent datasets.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/0008-5472.CAN-20-0332DOI Listing
August 2020

Synergistic effect of photodynamic therapy at 400 nm and doxycycline against .

Future Microbiol 2019 09;14:1199-1205

Department of Experimental & Clinical Medicine, University of Florence, Florence, Italy.

The objective of this study was to investigate the possible synergy between doxycycline and photodynamic therapy against and to evaluate the possible side effects on adenocarcinoma gastric cells with and without protoporphyrin IX. Three strains (ATCC 700392, 43504 and 49503) were grown on solid medium either with, or without, doxycycline at subinhibitory concentrations, and irradiated for 10, 20 and 30 minutes with a 400 nm-peaked light source. The phototoxicity tests on AGS cells were evaluated by MTT assay. The photodynamic therapy and doxycycline combination showed an antibacterial synergistic effect with no significant toxicities. The synergistic treatment could be considered as an interesting therapeutic option.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2217/fmb-2019-0129DOI Listing
September 2019

A multiparametric method to assess the MIM deformable image registration algorithm.

J Appl Clin Med Phys 2019 Apr 28;20(4):75-82. Epub 2019 Mar 28.

Department of Clinical and Experimental Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy.

A quantitative evaluation of the performances of the deformable image registration (DIR) algorithm implemented in MIM-Maestro was performed using multiple similarity indices. Two phantoms, capable of mimicking different anatomical bending and tumor shrinking were built and computed tomography (CT) studies were acquired after applying different deformations. Three different contrast levels between internal structures were artificially created modifying the original CT values of one dataset. DIR algorithm was applied between datasets with increasing deformations and different contrast levels and manually refined with the Reg Refine tool. DIR algorithm ability in reproducing positions, volumes, and shapes of deformed structures was evaluated using similarity indices such as: landmark distances, Dice coefficients, Hausdorff distances, and maximum diameter differences between segmented structures. Similarity indices values worsen with increasing bending and volume difference between reference and target image sets. Registrations between images with low contrast (40 HU) obtain scores lower than those between images with high contrast (970 HU). The use of Reg Refine tool leads generally to an improvement of similarity parameters values, but the advantage is generally less evident for images with low contrast or when structures with large volume differences are involved. The dependence of DIR algorithm on image deformation extent and different contrast levels is well characterized through the combined use of multiple similarity indices.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/acm2.12564DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6448167PMC
April 2019

Unstained cell imaging: Morphological insights from coupled fixation and darkfield microscopy.

Acta Histochem 2019 Feb 24;121(2):248-252. Epub 2018 Nov 24.

Department of Experimental and Clinical Biomedical Sciences "Mario Serio", Viale Pieraccini 6, 50139, Florence, Italy.

Cell staining techniques are well established in cell biology and associated with a broad range of dedicated dyes; however, they are accompanied by non-negligible costs, preparation time and unavoidable alterations of the sample with foreign molecules. In this context, we point out and propose the use of darkfield microscopy (DM) combined with different fixation protocols (to be used anyway) to enhance the different cell structures and districts as a timesaving and inexpensive support to the techniques that need staining or immuno-staining protocols and products. In a first step, we have analysed the effect of different fixation protocols on DM images for various human cellular lines. The presented imaging study shows that cell morphology actually changes with the fixation protocols that enhance, through contrast and luminosity variations, different shapes and patterns and thus structures of the cells. The different chemical action of various fixations, in fact, modifies the local scattering coefficient, thus affecting in a different way the morphology shown by DM images. As a second step we have compared the observed DM morphologies to those of selective fluorescent staining being therefore able to associate them to specific cell districts (e.g. nucleus, membrane or cytoskeleton). The obtained results indicate that this common microscopy technique can give images with particular cellular structures or districts enhanced more than others depending on the choice of fixation protocol. Therefore Darkfield Microscopy can be considered as a simpler, cheaper and faster method to provide morphological indications, respect to staining techniques, even at low and medium magnifications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.acthis.2018.11.006DOI Listing
February 2019

Side effects of intra-gastric photodynamic therapy: an in vitro study.

J Photochem Photobiol B 2018 Sep 12;186:107-115. Epub 2018 Jul 12.

Department of Experimental and Clinical Biomedical Sciences "Mario Serio", Viale Pieraccini 6, I-50139 Florence, University of Florence, Italy.

Since many years it has been acknowledged that some bacterial species, among which H. pylori, P. aeruginosa, P. acnes accumulate endogenous photosensitizers (PS) in the form of porphyrins. This makes antibacterial photodynamic therapy (PDT) easier to perform due to the possible avoidance of external PS. In this study, we focus on gastric infections associated with the presence of Helicobacter pylori (H. pylori), known to accumulate and release both protoporphyrin IX (PPIX) and coproporphyrins. PDT versus H. pylori can be carried out by modified endoscopes or by new ingestible luminous devices under development. In both cases of in vitro and in vivo applications, either for therapy (PDT) or diagnosis, scientific literature lacks studies on the possible side-effects of light treatments on the surrounding tissues. To this aim we evaluated in vitro side-effects due to a possible intrinsic photosensitivity of gastric mucosa or to a photosensitization by the PS released from the bacterium itself. Photo-toxicity studies were conducted on the AGS cell line (ATCC® CRL-1739™), commonly used as a model for the stomach mucosa tissue, considering PPIX as the photosensitizing agent. After first evaluations of PPIX dark toxicity, its uptake and accumulation sites, photo-toxicity tests were conducted using a LED light source peaked at 400 nm, by varying both PPIX concentration (50 nM - 2 μM) and light dose in the range 0.6-13 J/cm, representing different treatment procedures found in literature. The oxidative stress consequent to irradiation was investigated both in terms of ROS production and assessment of the activity of enzymes involved in ROS-related biological mechanisms. A significant phototoxic effect was found only for PPIX concentration > 100 nM for all tested light doses. This indicates that the evaluated photo-treatments do not cause side effects even with the sensitization due to PPIX released by the bacteria.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jphotobiol.2018.07.010DOI Listing
September 2018

Statistical detection of nanoparticles in cells by darkfield microscopy.

Phys Med 2016 Jul 2;32(7):938-43. Epub 2016 Jul 2.

Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, viale Pieraccini 6, I-50139 Florence, Italy.

In the fields of nanomedicine, biophotonics and radiation therapy, nanoparticle (NP) detection in cell models often represents a fundamental step for many in vivo studies. One common question is whether NPs have or have not interacted with cells. In this context, we propose an imaging based technique to detect the presence of NPs in eukaryotic cells. Darkfield images of cell cultures at low magnification (10×) are acquired in different spectral ranges and recombined so as to enhance the contrast due to the presence of NPs. Image analysis is applied to extract cell-based parameters (i.e. mean intensity), which are further analyzed by statistical tests (Student's t-test, permutation test) in order to obtain a robust detection method. By means of a statistical sample size analysis, the sensitivity of the whole methodology is quantified in terms of the minimum cell number that is needed to identify the presence of NPs. The method is presented in the case of HeLa cells incubated with gold nanorods labeled with anti-CA125 antibodies, which exploits the overexpression of CA125 in ovarian cancers. Control cases are considered as well, including PEG-coated NPs and HeLa cells without NPs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmp.2016.06.007DOI Listing
July 2016

In vitro assessment of antibody-conjugated gold nanorods for systemic injections.

J Nanobiotechnology 2014 Dec 5;12:55. Epub 2014 Dec 5.

Istituto di Fisica Applicata 'Nello Carrara', Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, 50019, Sesto Fiorentino, Italy.

Background: The interest for gold nanorods in biomedical optics is driven by their intense absorbance of near infrared light, their biocompatibility and their potential to reach tumors after systemic administration. Examples of applications include the photoacoustic imaging and the photothermal ablation of cancer. In spite of great current efforts, the selective delivery of gold nanorods to tumors through the bloodstream remains a formidable challenge. Their bio-conjugation with targeting units, and in particular with antibodies, is perceived as a hopeful solution, but the complexity of living organisms complicates the identification of possible obstacles along the way to tumors.

Results: Here, we present a new model of gold nanorods conjugated with anti-cancer antigen 125 (CA125) antibodies, which exhibit high specificity for ovarian cancer cells. We implement a battery of tests in vitro, in order to simulate major nuisances and predict the feasibility of these particles for intravenous injections. We show that parameters like the competition of free CA125 in the bloodstream, which could saturate the probe before arriving at the tumors, the matrix effect and the interference with erythrocytes and phagocytes are uncritical.

Conclusions: Although some deterioration is detectable, anti-CA125-conjugated gold nanorods retain their functional features after interaction with blood tissue and so represent a powerful candidate to hit ovarian cancer cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12951-014-0055-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4266900PMC
December 2014

Size dependent biological profiles of PEGylated gold nanorods.

J Mater Chem B 2014 Sep 7;2(36):6072-6080. Epub 2014 Aug 7.

Institute of Applied Physics "Nello Carrara", National Research Council, Via Madonna del Piano 10, Sesto Fiorentino, 50019 Italy.

The perspective of introducing plasmonic particles for applications in biomedical optics is receiving much interest. However, their translation into clinical practices is delayed by various factors, which include a poor definition of their biological interactions. Here, we describe the preparation and the biological profiles of gold nanorods belonging to five different size classes with average effective radii between ∼5 and 20 nm and coated with polyethylene glycol (PEG). All these particles exhibit decent stability in the presence of representative proteins, low cytotoxicity and satisfactory compatibility with intravenous administration, in terms of their interference with blood tissue. However, the suspension begins to become unstable after a few days of exposure to blood proteins. Moreover, the cytotoxicity is a little worse for smaller particles, probably because their purification is more critical, while undesirable interactions with the mononuclear phagocyte system are minimal in the intermediate size range. Overall, these findings hold implications of practical relevance and suggest that PEGylated gold nanorods may be a versatile platform for a variety of biomedical applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c4tb00991fDOI Listing
September 2014

A simple method to disentangle nanoparticle optical properties by darkfield microspectroscopy.

Microsc Res Tech 2014 Nov 28;77(11):886-95. Epub 2014 Jul 28.

Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, I-50139, Florence, Italy.

We present a darkfield optical microspectroscopy technique devoted to the disentangled measurement of the absorption and scattering cross sections of nanoparticle (NP) samples with variable concentration. The robustness of the method, including the needed instrumental calibrations, is examined in detail by analyzing and quantifying the major sources of statistic and systematic errors. As an exemplary case, results are presented on a gold NP colloid. The technique takes advantage of a simple inverted microscope, coupled with a spectrograph and equipped with a darkfield condenser and a variable numerical aperture objective to obtain spectra either in darkfield or brightfield optical configurations. By adopting the Lambert-Beer (LB) equation modeling, we were able to disentangle and measure with a single setup the absorption, scattering, and extinction coefficients of the same sample by combining three spectra, obtained by opportunely varying the objective numerical aperture. Typical plasmonic resonances were recognized at approximately 520 and 750 nm. Optical coefficients were measured as a function of particle number density (0.04-3.94 µm(-3), corresponding to 40 µM-4 mM nominal Au concentration) and good linearity was verified up to ∼1.5 µm(-3) (∼1 mM Au). Moreover, extinction and scattering cross sections were quantified and the validity of the LB approximation was reviewed. Besides its applications to plasmonic NPs, this method may be appropriate for any colloid, provided there exists a characteristic spectral feature in the ultraviolet-visible-near infrared range. This technique may be exploited to localize NPs in biological samples.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jemt.22411DOI Listing
November 2014

Quantitative readout of optically encoded gold nanorods using an ordinary dark-field microscope.

Nanoscale 2013 Oct;5(20):9645-50

INO-CNR, National Institute of Optics-CNR, Largo E. Fermi 6, Florence, Italy.

In this paper we report on a new use for dark-field microscopy in order to retrieve two-dimensional maps of optical parameters of a thin sample such as a cryptograph, a histological section, or a cell monolayer. In particular, we discuss the construction of quantitative charts of light absorbance and scattering coefficients of a polyvinyl alcohol film that was embedded with gold nanorods and then etched using a focused mode-locked Ti:Sapphire oscillator. Individual pulses from this laser excite plasmonic oscillations of the gold nanorods, thus triggering plastic deformations of the particles and their environment, which are confined within a few hundred nm of the light focus. In turn, these deformations modify the light absorbance and scattering landscape, which can be measured with optical resolution in a dark-field microscope equipped with an objective of tuneable numerical aperture. This technique may prove to be valuable for various applications, such as the fast readout of optically encoded data or to model functional interactions between light and biological tissue at the level of cellular organelles, including the photothermolysis of cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/c3nr00726jDOI Listing
October 2013

Colorimetric comparison of light-filtering intraocular lenses and human crystalline lenses at various ages.

J Cataract Refract Surg 2011 Apr;37(4):758-62

Department of Clinical Physiopathology, University of Florence, Florence, Italy.

Purpose: To perform colorimetric characterization of 2 blue light-filtering intraocular lens (IOL) models and an IOL that filters ultraviolet-violet (UV-v) light and compare the charactizations with those of a standard UV light-filtering IOL and the human crystalline lens at various ages.

Setting: Department of Clinical Physiopathology, University of Florence, and National Institute of Applied Optics, CNR, Florence, Italy.

Design: Experimental study.

Methods: Three IOLs of each model with different dioptric powers (16.0, 21.0, and 26.0 diopters) were analyzed. The colorimetric coordinates of the IOLs were calculated by measuring their transmission spectra using a microspectroscopy technique. Subsequently, a parameter (ΔE) that was proportional to the perceived color differences was defined. The results of the IOLs and of the human crystalline lens at different ages (4, 22, 41, 53, and 72 years; values taken from the literature) were compared. The colorimetric analysis was performed using Commission Internationale de l'Éclairage standards.

Results: The maximum ΔE value was with the standard UV light-filtering IOL at any crystalline lens age and was greatest with a 72-year-old human lens. The minimum ΔE value was obtained for both blue light-filtering IOLs with middle-aged human lenses.

Conclusions: None of the analyzed IOLs had the same colorimetric performance of the human crystalline lens. The 2 blue light-filtering IOLs best reproduced yellowing of the human lens at 40 to 50 years of age.

Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcrs.2010.10.053DOI Listing
April 2011

Fibroblast autofluorescence in connective tissue disorders: a future tool for clinical and differential diagnosis?

J Biomed Opt 2008 Sep-Oct;13(5):054025

University of Florence, Department of Clinical Physiopathology, ASAcampus, ASA Research Division, Florence, Italy.

Marfan syndrome (MFS) is an inherited disorder of connective tissue due to mutations in FBN1 (90%) and TGFBR1 and TGFBR2 (5 to 10%) genes. Clinical and differential diagnosis is difficult because of the inter- and intrafamiliar marked heterogeneity and the variable onset age of clinical manifestations. Among the disorders, in differential diagnosis, thoracic aortic aneurysm (TAA) and Ullrich scleroatonic muscular dystrophy (UCMD) are reported. We evaluate the possibility of utilizing autofluorescence (AF) analysis as a diagnostic tool in the clinical and/or differential diagnosis of MFS and related disorders and in the investigation of the molecular mechanisms involved. Both multispectral imaging autofluorescence microscopy (MIAM) and autofluorescence microspectroscopy (AMS) have been used to characterize AF emission of fibroblasts from patients affected by inherited connective tissue disorders. Our preliminary results show significant differences in AF emission between normal and pathological fibroblasts, suggesting possible improvement in diagnostics of connective tissue disorders by AF analysis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1117/1.2982533DOI Listing
February 2009

A new method based on contact surface profilometry for quantitative measurement of resorbed bone volume.

Phys Med 2005 January - March;21(1):41-6

Dept. of Clinical Physiopathology, Medical Physics Sect. University of Florence, Viale Pieraccini 6, I 50139 Florence (Italy).

Bone is a dynamic tissue. Its continuous remodeling depends on the balance between bone formation and bone resorption. These two processes are carried out by specialized cells called osteoblast and ostreoclast respectively. The osteoclastic bone resorption consists in degradation of the mineral and collagen components of bone. The study of bone turnover requires accurate assessment of osteoclastic bone resorption, that becomes even more important in pathologic bone loss due to the uncoupling between bone formation and bone resorption. Osteoclastic activity is diffucult to measure. Many techniques, generally based on the detection of the resorbing lacunae (lacunae (pits) due to the bone degradation, allow to estimate bone resorption, but none of them quantitatively and directly measures the volume of resorbed bone. We propose a reliable and relatively simple method, based on contact surfact profilometry, to evaluate directly and quantitatively the volume of resorbed bone. The method has the following advantages:
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/S1120-1797(05)80018-3DOI Listing
October 2012

Multispectral imaging autofluorescence microscopy in colonic and gastric cancer metastatic lymph nodes.

Clin Gastroenterol Hepatol 2007 Feb;5(2):230-6

Department of Critical Medicine and Surgery, University of Florence, Florence, Italy.

Background & Aims: The lymphadenectomy and extended lymphadenectomy procedures have been points of controversy in surgical oncology. The methods available for the detection of metastatic lymph nodes are numerous. These include lymphoscintigraphy and radiolabeled antibody detection, but in most cancers the currently used technique is sentinel lymph node identification, performed primarily through the use of immunohistochemistry. We propose the application of autofluorescence (AF)-based techniques for lymph node evaluation in colorectal and gastric tumors.

Methods: We studied 30 clinical cases: 15 colorectal cancers and 15 gastric cancers. All of the patients were in the advanced stages of the disease and were candidates for adjuvant therapy. Autofluorescence microspectroscopy and multispectral imaging autofluorescence microscopy have been used to analyze the AF emission of metastatic lymph node sections, excited with 365-nm wavelength radiation. The AF spectra were recorded in the range of 400-700 nm. Monochrome AF images were acquired sequentially through interference filters peaked at 450, 550, and 650 nm, and then combined together in a single red-green-blue image. The AF pattern and the emission spectrum of metastatic lymph nodes have unique characteristics that can be used to distinguish them from the normal ones.

Results: The results, compared with standard histopathologic procedures and with specific staining methods, supplied a satisfactory validation of the proposed technique, revealing the possibility of improving the actual diagnostic procedures for malignant lymph node alterations.

Conclusions: With the development of appropriate instrumentation, the proposed technique could be particularly suitable in intrasurgical diagnosis of metastatic lymph nodes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cgh.2006.11.013DOI Listing
February 2007

AcrySof Natural intraocular lens optical characteristics during and after different doses of ultraviolet-visible light illumination.

J Cataract Refract Surg 2006 Nov;32(11):1961-5

Department of Oto-Neuro-Ophthalmological Surgical Sciences-Eye Clinic, University of Florence, Italy.

Purpose: To determine the optical transmission properties of a recently introduced intraocular lens (IOL) (AcrySof Natural SN60AT, Alcon Laboratories) and compare them with those of a conventional IOL (AcrySof SA60AT, Alcon Laboratories) after ultraviolet (UV)-visible light irradiation.

Setting: Eye Clinic and Department of Clinical Physiopathology, University of Florence, and the National Institute of Applied Optics, Florence, Italy.

Methods: Two IOLs, the AcrySof Natural with a UV and blue-light filter and the AcrySof without a blue-light filter, were studied. Three IOLs of each model with different dioptric powers were examined in two experimental setups. The samples were stressed with very high irradiance to reproduce light aging, and the transmission properties of the IOLs were studied.

Results: No significant decrease in transmission was found at a UV-visible light dose equivalent to 100 years of light aging.

Conclusion: The AcrySof Natural IOL has stable optical characteristics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jcrs.2006.06.024DOI Listing
November 2006

Modeled gravitational unloading triggers differentiation and apoptosis in preosteoclastic cells.

J Cell Biochem 2006 May;98(1):65-80

CEO--Center of Excellence in Optronics, L. Enrico Fermi 6, I-50125 Florence, Italy.

Gravity acts permanently on organisms as either static or dynamic stimulation. Understanding the influence of gravitational and mechanical stimuli on biological systems is an intriguing scientific problem. More than two decades of life science studies in low g, either real or modeled by clinostats, as well as experimentation with devices simulating different types of controlled mechanical stimuli, have shown that important biological functions are altered at the single cell level. Here, we show that the human leukemic line FLG 29.1, characterized as an osteoclastic precursor model, is directly sensitive to gravitational unloading, modeled by a random positioning machine (RPM). The phenotypic expression of cytoskeletal proteins, osteoclastic markers, and factors regulating apoptosis was investigated using histochemical and immunohistochemical methods, while the expression of the corresponding genes was analyzed using RT-PCR. A quantitative bone resorption assay was performed. Autofluorescence spectroscopy and imaging were applied to gain information on cell metabolism. The results show that modeled hypogravity may trigger both differentiation and apoptosis in FLG 29.1 cells. Indeed, when comparing RPM versus 1 x g cultures, in the former we found cytoskeletal alterations and a marked increase in apoptosis, but the surviving cells showed an osteoclastic-like morphology, overexpression of osteoclastic markers and the ability to resorb bone. In particular, the overexpression of both RANK and its ligand RANKL, maintained even after return to 1 x g conditions, is consistent with the firing of a differentiation process via a paracrine/autocrine mechanism.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jcb.20747DOI Listing
May 2006

Simulated hypogravity impairs the angiogenic response of endothelium by up-regulating apoptotic signals.

Biochem Biophys Res Commun 2005 Aug;334(2):491-9

Section of Pharmacology, Department of Molecular Biology and C.R.I.S.M.A., University of Siena, Siena, Italy.

Health hazards in astronauts are represented by cardiovascular problems and impaired bone healing. These disturbances are characterized by a common event, the loss of function by vascular endothelium, leading to impaired angiogenesis. We investigated whether the exposure of cultured endothelial cells to hypogravity condition could affect their behaviour in terms of functional activity, biochemical responses, morphology, and gene expression. Simulated hypogravity conditions for 72 h produced a reduction of cell number. Genomic analysis of endothelial cells exposed to hypogravity revealed that proapoptotic signals increased, while antiapoptotic and proliferation/survival genes were down-regulated by modelled low gravity. Activation of apoptosis was accompanied by morphological changes with mitochondrial disassembly and organelles/cytoplasmic NAD(P)H redistribution, as evidenced by autofluorescence analysis. In this condition cells were not able to respond to angiogenic stimuli in terms of migration and proliferation. Our study documents functional, morphological, and transcription alterations in vascular endothelium exposed to simulated low gravity conditions, thus providing insights on the occurrence of vascular tissue dysregulation in crewmen during prolonged space flights. Moreover, the alteration of vascular endothelium can intervene as a concause in other systemic effects, like bone remodelling, observed in weightlessness.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbrc.2005.06.124DOI Listing
August 2005

Optical characterization of a radiochromic film by total reflectance and transmittance measurements.

Med Phys 2004 Jul;31(7):2147-54

Laser Center for Medical Application-CEO, Department of Clinical Physiopathology, University of Florence, and Sezione A INFM, Viale G. Pieraccini 6, 50139 Florence, Italy.

The GafChromic film (GCF) MD-55-2, a radiochromic material, was examined for its optical properties through total reflectance and transmittance measurements in visible spectrum (400-700 nm). By using a multilayer model of the film and Kubelka-Munk's (KM) theory, absorption and scattering coefficients of the film sensitive layer (K and S, respectively) were obtained from measurements of irradiated and nonirradiated slides. This has allowed calculation of the absorbance A(KM) of the sensitive layer of the GCF. The model easily splits scattering from absorption. Unlike absorption, scattering is essentially insensitive to irradiation dose and decreases slowly as the wavelength increases. The scattering effect is predominant over absorption in the 400-500 nm range, while beyond 600 nm absorption prevails. The A(KM) absorbance of the sensitive layer was calculated using the K coefficient and compared with the optical densities (OD) measured considering only ballistic photons (as in a standard spectrophotometer) as well as the optical densities measured collecting all the transmitted photons (as in many densitometers). The values of A(KM) found were always lower than OD measured by the other methods and they had the best linearity on the whole visible range. These data support the hypothesis that the sensitive layer reacts to irradiation more linearly than that shown by measurements using standard commercial devices. However, in the 600-680 nm range, correction is not very important because absorption is predominant over scattering. When GCF is used for imaging, scattering produces a loss of spatial information. Consequently, it is necessary to collect only ballistic photons and to correct absorbance by K and S coefficients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1118/1.1764701DOI Listing
July 2004

Dependence of leukemic cell autofluorescence patterns on the degree of differentiation.

Photochem Photobiol Sci 2003 Oct;2(10):981-7

Centre of Excellence in Optronics, Largo Enrico Fermi, 6, 50125 Florence, Italy.

The characterisation of leukemic cell autofluorescence during differentiation, induced by 12-O-tetradecanoylphorbol 13-acetate and all-trans retinoic acid, was performed by autofluorescence microspectroscopy and multispectral imaging autofluorescence microscopy. We have found that a dependence exists between the cell autofluorescence pattern and the degree of cell differentiation. When cells differentiate, their autofluorescence emission changes, following the morphological and functional rearrangement of cell structures. A decrease in emission intensity and a different distribution of endogenous fluorophores are observed. Thus, autofluorescence monitoring on living cells is a potentially useful tool for in vitro study of the differentiation processes. Furthermore, different maturation steps can be distinguished on the basis of the cell fluorescence pattern, leading the way to future application of the technique in diagnostics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1039/b306276gDOI Listing
October 2003

Changes in skin temperature of hyperbilirubinemic newborns under phototherapy: conventional versus fiberoptic device.

Am J Perinatol 2002 Nov;19(8):439-44

Department of Critical Care Medicine Section of Neonatology University of Firenze, Italy.

The purpose of this study is to determine the changes in skin temperature of hyperbilirubinemic term newborns under conventional and fiberoptic phototherapy. The study included a group of 41 hyperbilirubinemic, but otherwise healthy, term infants, all of appropriate size for gestational age. The study was devised to include two separate groups: group 1 of 21 infants (51.2%) received conventional phototherapy, and group 2 of 20 infants (48.8%) received fiberoptic phototherapy. In both groups the surface temperature on the forehead, abdomen, left leg and back was calculated by infrared radiation thermometer (Cyclops Compac 3, Minolta, Land, England). A "Photo-Therapie 800 Heraeus" unit (Drager, Lübeck, Germany) was used for conventional phototherapy (CPT). A "Biliblanket PT system" (Ohmeda, Louisville, KY) was used for fiberoptic phototherapy (FO-PT). In our study we did not find significant differences of skin temperature in the four areas examined in the two groups prior to phototherapy. During conventional phototherapy, mean values of skin temperature were found to be significantly higher than those found before phototherapy. During fibreoptic phototherapy no statistically significant temperature differences were found on the forehead, abdomen, leg, and back before and during phototherapy. Furthermore, a statistically significant increase in skin temperature was found during phototherapy on the forehead, abdomen, leg, and back in patients of group 1 with respect to patients of group 2. We demonstrated that fibreoptic phototherapy, in contrast to conventional phototherapy, does not induce a significant increase in skin temperature.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/s-2002-36839DOI Listing
November 2002