Noninvasive diagnosis of oral neoplasia based on fluorescence spectroscopy and native tissue autofluorescence.

OBJECTIVE: To evaluate the clinical potential of fluorescence spectroscopy (a noninvasive technique for assessing the chemical and morphologic composition of tissue) for in vivo detection of oral cavity neoplasia. DESIGN: A fluorescence spectroscopy system recorded spectra from oral cavity sites in 8 healthy volunteers and in 15 patients with premalignant or malignant oral cavity lesions at 337-, 365-, and 410-nm excitation wavelengths in the emission range of 350 to 700 nm. Fluorescence peak intensities and spectral line shapes were compared and diagnostic algorithms were developed to distinguish normal sites from abnormal sites. SETTING: The head and neck cancer clinic at a tertiary referral center in Houston, Tex. RESULTS: Differences were found in spectra from normal, dysplastic, and malignant oral mucosa. The fluorescence intensity of normal mucosa was greater than that of abnormal areas. In addition, the ratio of red region (635-nm) to blue region (455-490-nm) intensities was greater in abnormal areas. Diagnostic discrimination was achieved when test site spectra were compared with spectra from a normal site in the same patient. One diagnostic algorithm based on spectra at 337 nm gave a sensitivity of 88% and a specificity of 100%. CONCLUSIONS: Consistent differences exist between the fluorescence spectra of abnormal and normal oral mucosa. Therefore, fluorescence spectroscopy has the potential to improve the noninvasive diagnosis of oral cavity neoplasia. Further studies will better define the role of this technique in the detection of premalignant and early oral cancer lesions.

Effects of nicotine and nicotine/ethanol on human placental amino acids transfer.

Ethanol abuse and smoking during pregnancy both result in decreased offspring weight. One explanation for this may be impaired placental nutrient transport. This study assessed this possibility utilizing the 4-hr perfused human placental system and human placental vesicles exposed to "physiological," 0.2 microM and large (about 20 microM) nicotine concentrations alone, as well as nicotine combined with ethanol, 200 or 400 mg/ml, for up to 48 hr. Two nonmetabolizable amino acids, alpha-aminoisobutyric acid (AIB) and cycloleucine (CLEU) were used as probes. Nicotine was measured by gas chromatography in the placental perfusion system and vesicles and verified as to concentration. There was no statistically significant evidence of decreased transport of these amino acids with exposure to nicotine alone or nicotine and ethanol together in either test system. Thus, brief exposure to nicotine and ethanol does not impair amino acid transport by the human placenta.