PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 9511801

Laser-based spectroscopic methods in tissue characterization.

K Svanberg·C af Klinteberg·A Nilsson·I Wang·S Andersson-Engels·S Svanberg
View original source ↗Export metadata ↓

Abstract

Laser-based spectroscopic techniques were developed for tumor tissue characterization utilizing different tumor-localizing substances. In particular, sensitization with the heme precursor delta-amino levulinic acid (ALA) administered topically, orally or intravenously was used for the induction of protoporphyrin IX (PpIX). The autofluorescence as well as the PpIX-related fluorescence signals were monitored, and tumor demarcation functions were calculated for different human malignant tumors, such as tumors in the urinary bladder and the prostatic gland, in the head and neck region, in the breast and in the gastrointestinal tract. In the gastrointestinal tract, colon tumors were examined as well as tumors and dysplastic lesions in the esophagus, where patients with Barrett's esophagus were examined. Time-integrated laser-induced fluorescence measurements utilizing a point monitoring fluorosensor and a multicolor fluorescence imaging system were performed in vivo in patients in different clinical specialities.

Explore related subjects

FluorescenceHead and Neck NeoplasmsHumansLasersSkin NeoplasmsSpectrum AnalysisUrinary Bladder NeoplasmsJournal ArticleReview

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

K Svanberg, C af Klinteberg, A Nilsson, I Wang, S Andersson-Engels, S Svanberg. 1998-02-09. Laser-based spectroscopic methods in tissue characterization.. https://doi.org/10.1111/j.1749-6632.1998.tb08193.x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2001

Fluorescence of fungi in superficial and deep fungal infections.

BACKGROUND: Fluorescence of many fungi is noted when H&E stained sections are examined under a fluorescent microscope. In theory, this phenomenon could aid in the diagnosis of cutaneous and disseminated fungal infections without the delay associated with special stains. Seventy-six cases of superficial and deep fungal infections and 3 cases of protothecosis were studied to determine the clinical usefulness of this technique. RESULTS: In most cases, fluorescence was noted, but was not intense. Fluorescence of fungi did not correlate with the age of the specimen. In most cases, organisms in H&E stained sections were more easily identified with routine light microscopy than with fluorescent microscopy. CONCLUSION: This report suggests that in H&E stained skin specimens, fluorescent microscopy is of little benefit in the identification of fungal organisms.

Fluorescence↗
PubMed2001

Use of a green fluorescent protein gene as a reporter in Zymomonas mobilis and Halomonas elongata.

We investigated the applicability of the green fluorescent protein of Aequorea victoria as a reporter for gene expression in the strictly fermentative Gram-negative ethanologenic bacterium Zymomonas mobilis and in the moderately halophilic bacterium Halomonas elongata. We have succeeded to express a mutated gene of green fluorescent protein under the control of different promoters in Z. mobilis and H. elongata grown under various glucose or salt concentrations, respectively. Our results demonstrate that gfp can serve as an easily assayable reporter gene in both organisms. Maximum fluorescence was obtained in Z. mobilis grown aerobically and in H. elongata grown under elevated salt concentration in solid medium. For both bacteria the fluorescence obtained was higher when the gfp gene was placed under the control of a native promoter.

Fluorescence↗
PubMed2001

A fluorescence-based assay for transcription using a novel fluorescent GTP analogue.

A new fluorescent analogue of GTP (Cm-GTP) was synthesized, which contained a coumarin fluorophore attached to the gamma phosphorus. This compound was tested in transcription assays using T7 RNA polymerase as a model system. The fluorescent nucleotide was incorporated specifically at the 5' end of nascent RNA synthesized in two different modes of transcription initiation. In the first mode, with only Cm-GTP (+GTP), reiterative slippage synthesis occurred and poly rG ladders of up to 14 nucleotides were synthesized. In the second mode, with Cm-GTP (+GTP)+ATP+CTP, abortive transcripts of up to seven or eight nucleotides were synthesized. The fluorescence properties of the two types of RNA were studied in detail. There was greater reduction in fluorescence intensity in G-ladders than in abortive transcripts. Steady-state anisotropy and anisotropy decay indicated that the fluorophore motion was constrained in G-ladder RNAs as compared to abortive RNAs. Quenching experiments by using extraneous quenchers showed that the excited state of fluorophore at the 5' end of G-ladder RNA was less efficiently quenched as compared to the free fluorophore. These studies suggested that the fluorescent GTP analogue sensed the structural features that distinguished G-ladder RNAs from abortive RNAs. The results suggested that G-ladder RNAs adapt unusual conformations such as G-quartets. Thus, the new fluorescent probe can be useful for structural studies on RNA.

Fluorescence↗