Diagnosis of cervical neoplasia by the estimation of octadeca-9,11-dienoic acid

Can flow cytometry reduce the workload for cervical screening? The results of a series of 622 specimens

A simple method permitting the flow cytometric examination of cervical specimens has been developed and an assessment made of the feasibility of relying on this method to screen women for cervical neoplasia. Examination of four flow cytometric parameters showed differences between morphologically normal and abnormal specimens and allowed identification of a proportion of the normal specimens. The system had a false negative rate of 8%. Our experience with cervical specimens has revealed a number of problems associated with their examination by flow cytometry and these are discussed.

Oxidative stress status and cancer: methodology applicable for human studies

There is convincing evidence to suggest that oxidative stress status might be involved in the etiology of cancer, but relatively little direct human data are available. The National Cancer Institute recently sponsored a workshop evaluating methodology for measuring oxidative stress status with potential application to human studies.

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.

Rationale for antioxidant therapy in pancreatitis and cystic fibrosis

The overlapping features of the acquired diseases acute pancreatitis and chronic pancreatitis on the one hand, and of chronic pancreatitis and pancreatic involvement in the congenital condition cystic fibrosis on the other, suggest that the basic mechanism of pancreatic injury may be the same in each illness. We propose that pancreatic oxidant stress is the common denominator and, furthermore, that this is facilitated by a shortfall of micronutrient antioxidants in the face of heightened free radical activity through different sources. If so antioxidant supplements should alleviate symptoms. This deduction was supported by an exploratory dose-seeking study that spanned five years in 20 patients with recurrent (non-gall stone) acute or chronic pancreatitis and confirmed by a 20-week double-blind placebo-controlled crossover trial of the successful combination (daily doses of 600 micrograms organic selenium, 0.54 g vitamin C, 9000 IU B-carotene, 270 IU vitamin E and 2 g methionine) in a further 20 cases. A randomised trial of glutathione precursors, given intravenously for 24 hours after admission in patients with a first attack of acute pancreatitis, is in progress. Long-term trials of oral antioxidant formulas are planned in patients with cystic fibrosis.

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.

Observer variability in histopathological reporting of cervical biopsy specimens

Sections from 100 cervical biopsy specimens were studied by 12 consultant histopathologists to determine the robustness of the existing pathology terminology and classification. Analysis by kappa statistics showed good agreement in the diagnosis of CIN 3 and squamous carcinoma but an inability to distinguish accurately between the lesser grades of CIN. It is recommended that the classification be changed to low grade (present CIN 1 and 2) and high grade (present CIN 3) categories alone. There was very poor agreement in the identification of cellular changes associated with human papilloma virus (HPV) infection.

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

The percentage molar ratio (%MR) of the 9,11 and 9,12 isomers of octadecadienoic acid was determined in cervical exfoliated cells from 148 subjects, of whom 27 had cytologically proven intraepithelial neoplasia and in cervical biopsy specimens from 43 subjects, of whom 24 had histologically diagnosed cervical intraepithelial neoplasia. The %MR in both cervical biopsy specimens and exfoliated cells did not significantly differ in subjects with or without cervical intraepithelial neoplasia. The measurement of the %MR of 9,11:9,12 octadecadienoic acid has no role in the detection of cervical intraepithelial neoplasia.

The experimental and clinical pathology of diene conjugation

The simple spectroscopic measurement of diene conjugation has long been an established but somewhat problematic marker of free-radical activity in biological systems. The main diene-conjugated compounds in human tissues and tissue fluids have now been identified as esters of octadeca-9,11-dienoic acid (18:2(9,11)), a non-peroxide isomer of linoleic acid (18:2(9,12)); and a range of high-performance liquid chromatographic methods has been developed for their detection and measurement. Significant abnormalities of phospholipid-esterified 18:2(9,11) have been found in the serum of chronic alcoholics and in paraquat poisoning and of non-esterified 18:2(9,11) in lipolytic states. The phospholipid-esterified 18:2(9,11) is increased in the bile of patients with pancreatic disease. In exfoliated cells from the cervix uteri an abnormal molar ratio between phospholipid-esterified 18:2(9,11) and 18:2(9,12) may prove to be the most sensitive biochemical marker of precancerous change.

Quantitative assessment of cervical neoplasia by hydrolysed DNA assay

A hydrolysed component of DNA was measured in cervical smears from 187 women. The results clearly distinguished patients with cervical intraepithelial neoplasia and invasive carcinoma from a control group. This method could be automated.