A Study of Hormonal Effects in Cervical Smear Samples Using Raman Spectroscopy

Raman spectroscopy is a powerful tool that has the potential to be used as a screening method for cervical cancer. It is a label-free, low-cost method providing a biochemical fingerprint of a given sample. The objective of this study was to address patient-to-patient variability contributed by hormonal effects due to the menstrual cycle, the use of hormone-based contraceptives (HC) and the onset of menopause, and to determine if these changes would affect the ability to successfully identify dyskaryotic cells. Raman spectra were recorded from unstained ThinPrep cervical samples (45 cytology negative and 15 high-grade dyskaryosis (high-grade squamous intraepithelial lesion, HSIL) samples using a HORIBA Jobin Yvon XploRA system. HPV DNA testing was also performed. Clinical data collected included date of the last menstrual period, the use of HC and/or menopausal status. Spectral changes were observed depending on the day of the menstrual cycle and on the use of HC. Despite this, HSIL could be discriminated from normal cells regardless of the day on which the sample was taken or the use of HC

Improved Removal of Blood Contamination From ThinPrep Cervical Cytology Camples for Raman Spectroscopic Analysis

There is an unmet need for methods to help in the early detection of cervical precancer. Optical spectroscopy-based techniques, such as Raman spectroscopy, have shown great potential for diagnosis of different cancers, including cervical cancer. However, relatively few studies have been carried out on liquid-based cytology (LBC) pap test specimens and confounding factors, such as blood contamination, have been identified. Previous work reported a method to remove blood contamination before Raman spectroscopy by pretreatment of the slides with hydrogen peroxide. The aim of the present study was to extend this work to excessively bloody samples to see if these could be rendered suitable for Raman spectroscopy. LBC ThinPrep specimens were treated by adding hydrogen peroxide directly to the vial before slide preparation. Good quality Raman spectra were recorded from negative and high grade (HG) cytology samples with no blood contamination and with heavy blood contamination. Good classification between negative and HG cytology could be achieved for samples with no blood contamination (sensitivity 92%, specificity 93%) and heavy blood contamination (sensitivity 89%, specificity 88%) with poorer classification when samples were combined (sensitivity 82%, specificity 87%). This study demonstrates for the first time the improved potential of Raman spectroscopy for analysis of ThinPrep specimens regardless of blood contamination

The Potential of Biobanked Liquid Based Cytology Samples for Cervical Cancer Screening Using Raman Spectroscopy.

Patient samples are unique and often irreplaceable. This allows biobanks to be a valuable source of material. The aim of this study was to assess the ability of Raman spectroscopy to screen for histologically confirmed cases of Cervical Intraepithelial neoplasia (CIN) using biobanked liquid based cytology (LBC) samples. Two temperatures for long term storage were assessed; 80°C and -25°C. The utility of Raman spectroscopy for the detection of CIN was compared for fresh LBC samples and biobanked LBC samples. Two groups of samples were used for the study with one group associated with disease (CIN 3) and the other associated with no disease (cytology negative). The data indicates that samples stored at -80°C are not suitable for assessment by Raman spectroscopy due to a lack of cellular material and the presence of cellular debris. However, the technology can be applied to fresh LBC samples and those stored at -25°C and is, moreover, effective in the discrimination of negative samples from those where CIN 3 has been confirmed. Pooled fresh and biobanked samples are also amenable to the technology and achieve a similar sensitivity and specificity for CIN 3. This study demonstrates that cervical cytology samples stored within biobanks at temperatures that preclude cell lysis can act as a useful resource for Raman spectroscopy and will facilitate research and translational studies in this area

Raman Spectroscopic Detection of High-Grade Cervical Cytology: Using Morphologically Normal Appearing Cells

This study aims to detect high grade squamous intraepithelial cells (HSIL) by investigating HSIL associated biochemical changes in morphologically normal appearing intermediate and superficial cells using Raman spectroscopy. Raman spectra (n = 755) were measured from intermediate and superficial cells from negative cytology ThinPrep specimens (n = 18) and from morphologically normal appearing intermediate and superficial cells from HSIL cytology ThinPrep specimens (n = 17). The Raman data was subjected to multivariate algorithms including the standard principal component analysis (PCA)-linear discriminant analysis (LDA) and partial least squares discriminant analysis (PLS-DA) together with random subsets cross-validation for discriminating negative cytology from HSIL. The PCA-LDA method yielded sensitivities of 74.9%, 72.8%, and 75.6% and specificities of 89.9%, 81.9%, and 84.5%, for HSIL diagnosis based on the dataset obtained from intermediate, superficial and mixed intermediate/superficial cells, respectively. The PLS-DA method provided improved sensitivities of 95.5%, 95.2% and 96.1% and specificities of 92.7%, 94.7% and 93.5% compared to the PCA-LDA method. The results demonstrate that the biochemical signatures of morphologically normal appearing cells can be used to discriminate between negative and HSIL cytology. In addition, it was found that mixed intermediate and superficial cells could be used for HSIL diagnosis as the biochemical differences between negative and HSIL cytology were greater than the biochemical differences between intermediate and superficial cell types

Transplant Outcomes in Patients with Idiopathic Membranous Nephropathy

Background. The natural history of idiopathic membranous nephropathy and recurrent disease in transplants is variable. We performed a retrospective cohort study of renal transplant recipients with a primary diagnosis of idiopathic membranous nephropathy. We aimed to establish patterns of disease recurrence and to identify factors associated with disease recurrence. Methods. We accessed the Irish renal transplant database to identify patients with biopsy-proven idiopathic membranous nephropathy in receipt of a renal transplant between 1982 and 2010. A detailed medical chart review was performed in all cases, and a senior renal histopathologist reviewed all histology specimens. Results. The outcomes of 32 patients, in receipt of 36 grafts, are reported. There was a male preponderance ( = 29). Significant graft dysfunction, directly attributable to recurrent disease, was evident in 31% of cases at 10 years. There was no significant association between time on dialysis, HLA mismatch, occurrence of rejection, and the development of recurrent membranous disease. One patient was retransplanted twice; all three grafts were lost to aggressive recurrent membranous disease. Conclusions. It remains difficult to identify those that will develop recurrent membranous nephropathy. Almost one third of patients in this cohort developed clinically significant recurrent disease at 10 years

Development and Validation of a Raman Spectroscopic Classification Model for Cervical Intraepithelial Neoplasia (CIN)

The mortality associated with cervical cancer can be reduced if detected at the precancer stage, but current methods are limited in terms of subjectivity, cost and time. Optical spectroscopic methods such as Raman spectroscopy can provide a rapid, label-free and nondestructive measurement of the biochemical fingerprint of a cell, tissue or biofluid. Previous studies have shown the potential of Raman spectroscopy for cervical cancer diagnosis, but most were pilot studies with small sample sizes. The aim of this study is to show the clinical utility of Raman spectroscopy for identifying cervical precancer in a large sample set with validation in an independent test set. Liquid-based cervical cytology samples (n = 662) (326 negative, 200 cervical intraepithelial neoplasia (CIN)1 and 136 CIN2+) were obtained as a training set. Raman spectra were recorded from single-cell nuclei and subjected to a partial least squares discriminant analysis (PLSDA). In addition, the PLSDA classification model was validated using a blinded independent test set (n = 69). A classification accuracy of 91.3% was achieved with only six of the blinded samples misclassified. This study showed the potential clinical utility of Raman spectroscopy with a good classification of negative, CIN1 and CIN2+ achieved in an independent test set

Exact ground states for the four-electron problem in a Hubbard ladder

The exact ground state of four electrons in an arbitrary large two leg Hubbard ladder is deduced from nine analytic and explicit linear equations. The used procedure is described, and the properties of the ground state are analyzed. The method is based on the construction in r-space of the different type of orthogonal basis wave vectors which span the subspace of the Hilbert space containing the ground state. In order to do this, we start from the possible microconfigurations of the four particles within the system. These microconfigurations are then rotated, translated and spin-reversed in order to build up the basis vectors of the problem. A closed system of nine analytic linear equations is obtained whose secular equation, by its minimum energy solution, provides the ground state energy and the ground state wave function of the model.Comment: 10 pages, 7 figure

Exome Sequencing Identifies a Novel TRPV4 Mutation in a CMT2C Family

Molecular and Cellular Biolog