Alison Malkin

A comparative study: conventional preparation and ThinPrep® 2000 in respiratory cytology

A comparative study: conventional preparation and ThinPrep 2000 in respiratory cytology

Comparison of DNA Extraction from Cervical Cells Collected in PreservCyt Solution for the Amplification of Chlamydia Trachomatis

Objective:  The aim of this study was to compare and evaluate three methods of DNA extraction for the amplification of Chlamydia trachomatis in uterine cervical samples collected in PreservCyt solution. ThinPrep is the trade name for the slide preparation.

Current Advances in the Application of Raman Spectroscopy for Molecular Diagnosis of Cervical Cancer

Raman spectroscopy provides a unique biochemical fingerprint capable of identifying and characterizing the structure of molecules, cells, and tissues. In cervical cancer, it is acknowledged as a promising biochemical tool due to its ability to detect premalignancy and early malignancy stages. This review summarizes the key research in the area and the evidence compiled is very encouraging for ongoing and further research. In addition to the diagnostic potential, promising results for HPV detection and monitoring treatment response suggest more than just a diagnosis prospective. A greater body of evidence is however necessary before Raman spectroscopy is fully validated for clinical use and larger comprehensive studies are required to fully establish the role of Raman spectroscopy in the molecular diagnostics of cervical cancer.

Evaluation of liquid‐based cytology in cervical screening of high‐risk populations: a split study of colposcopy and genito‐urinary medicine populations

A split study evaluated the ThinPrep® PapTest™ (TP; Cytyc Corp., Boxborough, MA) compared with current methodologies of cervical cytology in two high‐risk cohorts. One thousand, three hundred cases from a colposcopy clinic and a genito‐urinary medicine outpatient clinic were examined. The TP reported increased detection of all grades of dyskaryosis (mild, moderate and severe; + 4.5%) and a decrease in borderline and unsuitable cases (− 4.9%). Four cases of high‐grade dyskaryosis (moderate or severe) were detected only using the TP, while an additional four cases classified as high‐grade dyskaryosis with the TP were reported as borderline by our conventional methods. The split‐study finding of increased sensitivity with the TP provides for improved clinical management of patients in our high‐risk cohorts.

Human Papillomavirus Prevalence and Genotypes in an Opportunistically Screened Irish Female Population

Abstract This study aims to evaluate human papillomavirus (HPV) prevalence and predominating genotypes in liquid-based cervical cytology samples from an Irish urban female population. In addition to use of routine cervical cytology testing, women are screened for HPV using the MY09/11 primers for the HPV L1 gene and primers for β-globin amplification in a multiplex format. Overall, 996 women between the ages of 16 and 72 years (average age: 35) are included in the study and HPV prevalence was 19.8%. Cytology results showed that 88.9% were normal, 9% borderline or mild dyskaryosis, 1.1% moderate dyskaryosis and 0.9% severe dyskaryosis. Human papillomavirus prevalence in women under 25 was 31%, reducing to 23% in women in the 25–35 age group and to 11% in women over 35. Human papillomavirus prevalence increased with grade of cytology from 11.4% (normal) through 85.4% (borderline), 84% (mild), 100% (moderate) to 100% (severe dyskaryosis). HPV 16 (20%) and 18 (12%) were the most common high-risk types detected in the study. Other common high-risk types were (in descending order) HPV 66, 33, 53, 31 and 58. HPV 66 was associated with the detection of borderline abnormalities by cytology. This is the first population-based study of HPV prevalence in the normal healthy cervical screening population in the Republic of Ireland.

Methodologies for bladder cancer detection with Raman based urine cytology

Bladder cancer has the highest recurrence rate of any cancer. The American Urological Association recommends cystoscopic surveillance every 3–6 months for 3 years, and at least once a year thereafter, particularly for high-risk patients; however, cystoscopy is invasive, expensive, and is not without insignificant morbidity for the patient. Urine cytology is often used as an adjunct to cystoscopy; however, it has a low sensitivity in detecting low grade bladder cancers. Recent studies have investigated the application of Raman micro-spectroscopy for the detection of bladder cancer via urine cytology, and it has been demonstrated to significantly improve the diagnostic sensitivity of urine cytology for low grade bladder cancer under ideal experimental conditions. In this paper we attempt to move Raman micro-spectroscopy a step closer to the clinic by systematically examining the potential of this technology to classify low and high grade bladder cancer cell lines under the stringent clinical conditions that can be expected in the standard pathology laboratory, in terms of consumables, protocols, and instrumentation. We show that the use of glass slides, traditional fixing agents, lengthy exposure to urine, red blood cell lysing agents, as well as common cell deposition methods, do not significantly impact on the diagnostic potential of Raman based urine cytology. This study suggests that urine samples prepared with the ThinPrep® UroCyte™ method and analysed with Raman micro-spectroscopy could provide a useful alternative to cystoscopy for long term bladder cancer surveillance.

Chlamydia trachomatis detection in cervical PreservCyt specimens from an Irish urban female population.

Objective:  The aim of this study was to determine the prevalence of cervical Chlamydia trachomatis infection by polymerase chain reaction (PCR) in urban women undergoing routine cervical cytological screening and to investigate the relationship with age, cytology, smoking status and concurrent human papillomavirus (HPV) infection.

Development of Methodology for Raman Microspectroscopic Analysis of Oral Exfoliated Cells

Oral squamous cell carcinoma ranks as the 15th most common cancer worldwide. The present study was undertaken to standardise a protocol for the analysis of oral exfoliated cells using Raman microspectroscopy. For this purpose, samples were obtained from two different sites, based on prevalence of disease (ventral side of the tongue and buccal mucosa). Different oral rinsing agents were employed and it was concluded that non-alcoholic mouthwash adequately removes food debris. Samples were collected using various collection tools and compared. It was observed that endo-cervical brushes yielded cells from deeper layers of the epithelium. Furthermore, monolayer formation of cells was carried out adopting cytospin and ThinPrep techniques and only the ThinPrep method provided flat and separated cells on the glass slide. Raman spectra were acquired from the nuclear and cytoplasmic regions of the cell using an XploRA confocal Raman instrument (HORIBA Jobin Yvon) with a 532 nm laser as the source. Glass spectral contamination was removed using non negatively constrained least squares (NNLS) algorithms. Corrected spectra were subjected to principal components analysis (PCA) which was able to differentiate the nucleus and cytoplasm regions of the cell; based on nucleic acid and protein features, respectively. However, no classification of the two anatomically different sites was observed according to PCA or PCA–LDA (linear discriminant analysis) using either the nuclear or cytoplasmic spectra. Nevertheless, the study has developed a standardised protocol for sample collection, sample preparation, spectral acquisition and data processing for future studies of oral exfoliated cells based on Raman microspectroscopy.

Raman spectroscopy for the preoperative diagnosis of thyroid cancer and its subtypes: An in vitro proof-of-concept study

In 2016, there were an estimated 56 870 new cases of thyroid cancer (TC) in the USA. Fine needle aspiration cytology (FNAC) is the most safe, accurate and cost‐effective method for the initial investigation of thyroid nodules. FNAC is limited by the inability to diagnose malignancy in follicular‐patterned lesions accurately and, as a result, 20%‐30% of cases under investigation for TC are classified as cytologically indeterminate, illustrating a problem with current FNAC procedure. Raman spectroscopy has shown promising results for the detection of many cancers; however, to date there has been no report on the performance of Raman spectroscopy on thyroid cytological samples. The aim of this study was to examine whether Raman spectroscopy could be used to correctly classify cell lines representing benign thyroid cells and various subtypes of TC.