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Journal Article↗
Biomedical subjects
Robert R Alfano
Publications and source records attributed to Robert R Alfano.
The fluorescence of thyroid tissue.
OBJECTIVE: To investigate the fluorescent characteristics of different thyroid tissues. STUDY DESIGN: Fresh ex vivo thyroid tissue was surfaced scanned with a fluorescence spectrophotometer. Resultant spectra were evaluated via interpeak ratios. RESULTS: Interpeak ratios of all histologies were found to be significantly different from each other (P < 0.001). The diagnostic sensitivity and specificity of fluorescent spectroscopy was 86% and 91% for thyroid nodule capsule, 78% and 59% for papillary thyroid carcinoma, and 82% and 63% for normal thyroid, respectively. CONCLUSION: Fluorescent spectroscopy can been used to identify significant differences in the fluorescent characteristics of various thyroid histologies. SIGNIFICANCE: This study is the first investigation of the fluorescence of thyroid tissue. The diagnostic ability of fluorescent spectrometry may allow it to be used as a localization aid for fine needle aspiration, using optical fiber probes. Further investigations may enhance the sensitivity and specificity of fluorescent spectrometry allowing it to replace or compliment fine needle aspiration. EBM RATING: B-3.
Adenocarcinoma, Papillary↗
Native fluorescence and excitation spectroscopic changes in Bacillus subtilis and Staphylococcus aureus bacteria subjected to conditions of starvation.
Fluorescence emission and excitation spectra were measured over a 7-day period for Bacillus subtilis (Bs), a spore-forming, and Staphylococcus aureus (Sa), a nonspore-forming bacteria subjected to conditions of starvation. Initially, the Bs fluorescence was predominantly due to the amino acid tryptophan. Later, a fluorescence band with an emission peak at 410 nm and excitation peak at 345 m, from dipicolinic acid, appeared. Dipicolinic acid is produced during spore formation and serves as a spectral signature for detection of spores. The intensity of the 410-nm band continued to increase over the next 3 days. The Sa fluorescence was predominantly from tryptophan and did not change over time. In 6 of the 17 Bs specimens studied, an additional band appeared with a weak emission peak at 460 cm and excitation peaks at 250, 270, and 400 nm. The addition of beta-hydroxybutyric acid to the Bs or the Sa cultures resulted in a two-order of magnitude increase in the 460-nm emission. The addition of Fe2+ quenched the 460 emission, indicating that a source of the 460-nm emission was a siderophore produced by the bacteria. We demonstrate that optical spectroscopy-based instrumentation can detect bacterial spores in real time.
3-Hydroxybutyric Acid↗
Detection of glutamate in the eye by Raman spectroscopy.
Raman spectroscopy is used to detect glutamate in the eye. Glutamate, a by-product of nerve cell death, is an indicator of glaucoma and diabetic retinopathy. The Raman spectra of ex vivo whole porcine eyes and individual components (lens, cornea, vitreous) are measured and characterized. Monosodium glutamate is injected into the eyes to simulate disease conditions, and the contribution to the Raman spectrum due to the presence of glutamate is identified. The Raman spectra from the native eye is dominated by vibrational modes from proteins in the lens. An optical system is designed to optimize collection of signal from the vitreous, where the glutamate is located, and reduce the Raman from the lens. Two vibrational fingerprints of monosodium glutamate are detected at 1369 and 1422 cm(-1), although the concentrations are much above physiological concentrations.
Animals↗