A study of the morphological parameters of cervical squamous epithelium

Medical Physics and Engineering, University of Sheffield, Floor I, Royal Hallamshire Hospital, Glossop Road, Sheffield S 10 2JF, UK.
Physiological Measurement (Impact Factor: 1.62). 03/2003; 24(1):121-35. DOI: 10.1088/0967-3334/24/1/309
Source: PubMed

ABSTRACT Electrical impedance spectroscopy is a technique that has been investigated as a potential method for the diagnosis of epithelial carcinomas. Finite element modelling can provide an insight into the patterns of current flow in normal and pathological epithelium and hence aid in the process of probe design optimization. In order to develop a finite element model of the structure of normal and precancerous cervical squamous epithelium, it was first necessary to obtain the mean values and ranges of a number of morphological tissue parameters. The most important parameters in discriminating normal from neoplastic tissue were identified as being cell size and shape distribution, nuclear-to-cytoplasmic volume ratio and volume of extracellular space. A survey of the literature revealed an absence of reliable quantitative data for these parameters. We therefore present the results of our own basic image analysis on normal and pathological tissue sections, which we hope will be of use to other workers wishing to model cervical squamous epithelium, or other similar tissue structures.

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Available from: Anthony D. Blackett, Aug 10, 2015
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    • "We are currently working on the separated calculation of these parameters using global optimization approaches. As a preliminary attempt to validate the findings of GSA we use the curves illustrated in fig. 2 and the information from [16], which correlates CIN grade and the number of neoplastic epithelial cell layers. The number of dysplastic layers are 1-4 for CIN I, 5-8 for CIN II and greater than 9 for CIN III. "
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    ABSTRACT: We present a method for detecting and studying neoplasia-specific functional and structural features through the combination of in vivo dynamic imaging, in silico modeling and global sensitivity analysis. We particularly present the case of cervical epithelium interacting with acetic acid solution, which is employed as an optical biomarker. The in vivo measured dynamic scattering characteristics are strongly correlated with the output of the biomarker's pharmacokinetic model that we have developed. Model global sensitivity analysis has shown that the measured/modeled bio-optical processes can be used for probing, in vivo, the number of neoplastic layers, the extracellular pH, the intracellular buffering efficiency and the size of the extracellular space.
    Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 08/2011; 2011:95-9. DOI:10.1109/IEMBS.2011.6089905
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    • "Implementing a generic mathematical model of the skin can (i) aid in the design and operation of the electrodes, (ii) increase the probability of extracting the most relevant signals and (iii) also be implemented to evaluate the feasibility of an impedance study. A generic model, however, that aims to capture all the physiochemical phenomena, tissue types and structures inside the various layers of the skin—hair follicles, pores (Tronstad et al 2008), sweat ducts (Tronstad et al 2008), pH gradients (Norlen et al 2008), diurnal variations (Tsukahara et al 2001) as well as a multitude of other factors—can easily lose tractability; therefore, simplifications in the mathematical formulation are usually invoked (Martinsen et al 1999, Walker et al 2003, 2002, 2005, Jones et al 2003, Keshtkar et al 2006, Hartinger et al 2010). It is further well known that the impedance of the skin is governed by the stratum corneum at lower frequencies whilst its influence decreases when the frequency increases (Ackmann and Seitz 1984). "
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    ABSTRACT: The functional integrity and pathology of the skin is reflected in its electrical impedance spectra. Non-invasive electrical impedance measurements of intact skin are dominated by the high impedic stratum corneum in low frequencies and with increasing frequency gradually comes to be dominated by viable skin. Models of this multi-layered organ can increase our understanding of the actual physical properties/dimensions and facilitate better diagnostics in certain applications. Therefore, a mathematical model considering conservation of charge in the various layers of the skin and adjacent electrodes is derived and validated with experimental findings; the latter was carried out on 60 young female subjects. The impact of the stratum corneum thickness, inundation, solvent and cohort size on the electrical properties is studied. Both model parameters and experimental conditions were adjusted for calibration and subsequent validation of the model with measurements. It is found that both the model's thickness of the stratum corneum as well as experimental soaking conditions (both time and saline concentration) affect the fit between the model and measurements. It is concluded that it is essential that the electrical properties of the skin are presented in the context of the ion concentration (if a moisturizer is employed) as well as the soaking time. Further refinements should be made to determine even more accurate dielectrical properties of the stratum corneum and viable skin layers by accounting for the true skin thickness and the heterogeneity of the skin layers-this would be useful in applications where subtle alterations in the skin are of interest.
    Physiological Measurement 01/2011; 32(1):1-18. DOI:10.1088/0967-3334/32/1/001 · 1.62 Impact Factor
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    • "are the lengths of the domain in the x and y directions (the mesh had a size of 150 Â 100 cell locations, approximately corresponding to the guinea-pig endocervix, given the size of the endocervix and the size of the epithelial cells; Walker, 2003) and f(x, y) was taken to be an initial randomly generated band of coverage of an initial challenge of 10 4 IFUs over a 100 Â 10 cell area (see Fig. 1). The periodic boundary condition (2) effectively ties the two sides of the domain together, forming a cylinder. "
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    ABSTRACT: Sexually transmitted chlamydial infection initially establishes in the endocervix in females, but if the infection ascends the genital tract, significant disease, including infertility, can result. Many of the mechanisms associated with chlamydial infection kinetics and disease ascension are unknown. We attempt to elucidate some of these processes by developing a novel mathematical model, using a cellular automata-partial differential equation model. We matched our model outputs to experimental data of chlamydial infection of the guinea-pig cervix and carried out sensitivity analyses to determine the relative influence of model parameters. We found that the rate of recruitment and action of innate immune cells to clear extracellular chlamydial particles and the rate of passive movement of chlamydial particles are the dominant factors in determining the early course of infection, magnitude of the peak chlamydial time course and the time of the peak. The rate of passive movement was found to be the most important factor in determining whether infection would ascend to the upper genital tract. This study highlights the importance of early innate immunity in the control of chlamydial infection and the significance of motility-diffusive properties and the adaptive immune response in the magnitude of infection and in its ascension.
    FEMS Immunology & Medical Microbiology 09/2009; 57(2):173-82. DOI:10.1111/j.1574-695X.2009.00596.x · 2.55 Impact Factor
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