Diagnostic significance of octadeca-9,11-dienoic acid in cervical neoplasia

Fatty acid composition of clinically healthy and malignant oral epithelium

The fatty acid composition of epithelium from clinically healthy oral mucosa and or oral squamous cell carcinoma was analyzed by gas/liquid chromatography following extraction using a modified Folch technique and conversion of fatty acids to methyl esters. There were significant reductions in the relative proportions of palmitoleic and oleic acids and elevation of the relative proportions of palmitic, steric and arachidonic acids in samples from squamous cell carcinoma. These differences could reflect changes in cell membranes and/or fatty acid metabolism. Further studies are required to assess their functional, diagnostic and prognostic significance.

Studies on cervical intraepithelial neoplasia: the level of octadeca-9,11-dienoic acid and measurement of free radical content by electron spin resonance spectroscopy

The efficacy of electron spin resonance spectroscopy (a technique that measures free radicals) in detecting cervical intraepithelial neoplasia was evaluated in 68 women. In addition, electron spin resonance spectroscopic data were correlated with the phospholipid-esterified octadeca-9,11-dienoic acid (18:2(9,11]/octadeca-9,12-dienoic acid (18:2(9,12] molar ratio, a suggested marker of free radical damage to linoleic acid. Incubation of cervical epithelial cells with the spin-trap N-tert-butyl-alpha-phenylnitrone and subsequent examination by electron spin resonance spectroscopy gave signals from a nitroxide radical, which has been tentatively assigned to an adduct from either a carbon-centered lipid radical or a lipid alkoxyl radical; no significant differences in either the type of radical detected or the intensity of the signals was found between patients with cervical intraepithelial neoplasia and normal control subjects. There was no significant correlation between the intensity of the electron spin resonance signal and the phospholipid-esterified 18:2(9,11)/18:2(9,12) molar ratio. This finding provides no support for the classification of 18:2(9,11) as a "free radical product."

Inflammatory response, neutrophil activation, and free radical production after acute myocardial infarction: effect of thrombolytic treatment

Activated neutrophils releasing proteolytic enzymes and oxygen free radicals have been implicated in extending myocardial injury after myocardial infarction. Neutrophil elastase was used as a marker of neutrophil activation and the non-peroxide diene conjugate of linoleic acid was used as an indicator of free radical activity in 32 patients after acute myocardial infarction; 17 were treated by intravenous thrombolysis. Patients with acute myocardial infarction had higher plasma concentrations of neutrophil elastase and the non-peroxide diene conjugated isomer of linoleic acid than normal volunteers or patients with stable ischaemic heart disease. Patients treated by thrombolysis had an early peak of neutrophil elastase at eight hours while those who had not been treated by thrombolysis showed a later peak 40 hours after infarction. The plasma concentration of non-peroxide conjugated diene of linoleic acid was highest 16 hours after the infarction irrespective of treatment by thrombolysis. Quantitative imaging with single photon emission tomography showed decreased uptake of indium-111 labelled neutrophils in the infarcted myocardium (as judged from technetium-99m pyrophosphate) in those who had received thrombolysis, suggesting a decreased inflammatory response. The results indicate increased neutrophil activation and free radical production after myocardial infarction; they also suggest that thrombolysis does not amplify the inflammatory response and may indeed suppress it.

Octadeca-9,11-dienoic acid in cervical intraepithelial neoplasia: a colposcopic study

488 women were studied to evaluate the use of the molar ratio (%MR) of octadeca-9,11-dienoic acid (18:2(9, 11] to linoleic acid (18:2(9, 12] as a new screening method for cervical cancer and pre-cancer. A combination of Papanicolaou cytology, colposcopy and %MR 18:2(9, 11)/18:2(9, 12) were employed. 86 women (17.6%) were found to have histologically proven cervical intraepithelial neoplasia (CIN). The %MR was obtained in 452 cases (92%). There was no significant difference in %MR in cervical cell scrapes from women with or without CIN. The %MR of cervical scrapes in some women with anaerobic vaginosis was significantly elevated suggesting bacterial generation of 18:2(9, 11). The %MR of 18:2(9, 11)/18:2(9, 12) is unsuitable for the diagnosis of cervical intraepithelial neoplasia.

Identification of octadeca-9,11-dienoic acid and its significance in the diagnosis of cervical intraepithelial neoplasia

In 1987 it was claimed using high performance liquid chromatography (HPLC) that the molar ratio of octadeca-9,11-dienoic acid to its parent linoleic acid (18:2 (9,12)) was raised in malignant and premalignant conditions of the cervix. In this study based on a gas chromatographic procedure which prevents autoxidation and avoids the detection limitations of HPLC, we have shown that assay of these fatty acids has no role to play in the assessment of cervical neoplasia.

Increased levels of vaccenic acid in bronchogenic carcinoma tissue

Employing capillary gas liquid chromatography the levels of palmitic, palmitoleic, stearic, oleic, cis-vaccenic, linoleic, arachidonic and docosahexaenoic acids were measured in lung tissue and lung tumours from 28 patients undergoing surgery for bronchogenic carcinoma. There were significant increases in the majority of fatty acids in tumour tissue compared to normal tissue when the results were expressed in absolute units. However, when the relative changes in fatty acid concentration were studied, the most consistent findings were a significant rise in vaccenic acid and a fall in palmitic acid in tumour tissue compared to normal tissue. This change in the vaccenic:palmitic acid ratio may reflect specific changes in fatty acid metabolism in bronchogenic carcinoma tissue involving a delta-9 desaturase.