The objective of this study was to assess the performance of cervical impedance spectroscopy in the detection of cervical intraepithelial neoplasia (CIN) using the new MKIII impedance probe. A prospective observational study recruited women referred to colposcopy with an abnormal Papanicolaou smear. A pencil probe incorporating four gold electrodes was used to measure electrical impedance spectra from cervical epithelium. Colposcopy examinations, including probe positioning, were video recorded to allow for correlation between results obtained from colposcopic impression, histopathologic examination of colposcopic punch biopsies, and impedance measurements. Cervical impedance-derived parameters R, S, R/S, C, and Fc were assessed to see if significant difference in values obtained in CIN and normal epithelium existed. The performance of the probe in identifying women with CIN was also assessed. One hundred seventy-six women were recruited and 1168 points analyzed. Parameters R, S, and Fc showed significant separation of CIN or squamous intraepithelial lesion (SIL) from squamous, mature metaplastic, and columnar epithelium. Sensitivities of 74% and specificity of 53% can be achieved in identifying CIN 2/3 (High-grade SIL) in screened women. We conclude that cervical impedance spectrometry provides a potentially promising real-time screening tool for CIN with similar sensitivity and specificity to currently used screening tests. Further research is ongoing to develop the probe for potential clinical use.

Objective To compare cervical impedance spectrometry in the cervical epithelium of women with cervical intraepithelial neoplasia (CIN) and normal epithelium. Design Prospective observational study.Setting Colposcopy clinic, Jessop Wing, Royal Hallamshire Hospital, Sheffield, UK.Population Eighty-seven women referred to colposcopy with a moderate or severely dyskaryotic smear.Methods A pencil probe incorporating four gold electrodes was used to measure an electrical impedance spectrum from cervical epithelium. Colposcopy examinations, including probe positioning, were recorded by video to allow for correlation between results obtained from colposcopic impression, histopathological examination of colposcopically directed punch biopsies and the impedance measurements. Main outcome measures Cervical impedance derived parameters R, S and C were assessed to see if there was a significant difference in values obtained in CIN and normal squamous epithelium. Analysis was based upon matching the electrical components measured to those identified by cellular modelling as being most sensitive for premalignancy. Results From normal epithelium through CIN 1 to CIN 2/3, R decreased by a factor of 4.5, S increased by a factor of 2.5 but C remained unchanged. Conclusions Cervical impedance spectrometry provides a potentially promising screening tool with similar sensitivity and specificity to currently used screening tests, but with the potential advantage of providing instant results. Further work is currently being undertaken to improve the probe in its clinical use.

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The use of reference genes is the most common method of controlling the variation in mRNA expression during quantitative polymerase chain reaction, although the use of traditional reference genes, such as β‑actin, glyceraldehyde‑3‑phosphate dehydrogenase or 18S ribosomal RNA, without validation occasionally leads to unreliable results. Therefore, the present study aimed to evaluate a set of five commonly used reference genes to determine the most suitable for gene expression studies in normal ovarian tissues, borderline ovarian and ovarian cancer tissues. The expression stabilities of these genes were ranked using two gene stability algorithms, geNorm and NormFinder. Using geNorm, the two best reference genes in ovarian cancer were β‑glucuronidase and β‑actin. Hypoxanthine phosphoribosyltransferase‑1 and β‑glucuronidase were the most stable in ovarian borderline tumours, and hypoxanthine phosphoribosyltransferase‑1 and glyceraldehyde‑3‑phosphate dehydrogenase were the most stable in normal ovarian tissues. NormFinder ranked β‑actin the most stable in ovarian cancer, and the best combination of two genes was β‑glucuronidase and β‑actin. In borderline tumours, hypoxanthine phosphoribosyltransferase‑1 was identified as the most stable, and the best combination was hypoxanthine phosphoribosyltransferase‑1 and β‑glucuronidase. In normal ovarian tissues, β‑glucuronidase was recommended as the optimum reference gene, and the most optimum pair of reference genes was hypoxanthine phosphoribosyltransferase‑1 and β‑actin. To the best of our knowledge, this is the first study to investigate the selection of a set of reference genes for normalisation in quantitative polymerase chain reactions in different ovarian tissues, and therefore it is recommended that β‑glucuronidase, β‑actin and hypoxanthine phosphoribosyltransferase‑1 are the most suitable reference genes for such analyses.

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