Thin-layer Specimens Research Articles

New pathways for improved quantification of energy-dispersive X-ray spectra of semiconductors with multiple X-ray lines from thin foils investigated in transmission electron microscopy.

Theoretical approaches to quantify the chemical composition of bulk and thin-layer specimens using energy-dispersive X-ray spectroscopy in a transmission electron microscope are compared to experiments investigating (In)GaAs and Si(Ge) semiconductors. Absorption correctors can be improved by varying the take-off angle to determine the depth of features within the foil or the samples thickness, or by definition of effective k-factors that can be obtained from plots of k-factors versus foil thickness or, preferably, versus the K/L intensity ratio for a suitable element. The latter procedure yields plots of self-consistent absorption corrections that can be used to determine the chemical composition, iteratively for SiGe using a set of calibration curves or directly from a single calibration curve for InGaAs, for single X-ray spectra without knowledge of sample thickness, density or mass absorption coefficients.

Working toward consensus among professionals in the identification of classical cervical cytomorphological characteristics in whole slide images

Introduction: Cervical cancer is one of the most common causes of death in women worldwide.[1] The introduction of cervical cytology in screening programs is an effective way for early detection and treatment of cervical precancerous lesions. Conventional screening of cervical cytology slides is still considered the current “gold standard” for the assessment of proficiency in becoming a cytotechnician, but diagnosis using digital whole slide images (WSI) may offer many advantages. Materials and Methods: In this study, we have used a selection of WSI from thin-layer specimens of the most common cervical infections and (pre) neoplastic lesions, and hypothesized that weekly WSI based case-meetings would help to obtain optimal acceptance of the new digital workflow in daily pathology practice. A questionnaire, before and after the test period was used to study the effect of our approach. Results: The participants clearly had to go through a learning curve to get accustomed to viewing WSI. In the beginning, there was a little self-confidence in recognizing classical cervical cytomorphological features in the WSI, and there were complaints about the speed of viewing and insufficient Z-resolution for cell groups. Adjusting the Z-stack settings resulted in better three-dimensional information due to better focusing options. Weekly meetings appeared to be instrumental in the implementation process, as participants had to select and present WSI from thematic cases themselves, and thereby, got used to viewing WSI. Some WSI were replaced by better ones until a final set of 45 representatives WSI remained. Eventually, the consensus was reached among all participants that cytomorphological features in WSI from thin-layers cervical specimens could comparably be appreciated in WSI as by conventional microscopy. The selection of 45 WSI was now used to create a digital WSI based reference atlas to support further studies. Conclusion: We have obtained consensus between professionals that WSI from cervical cytology can be used to identify cytomorphological features, necessary for diagnosis. In addition, we observed that active participation of professionals had a positive effect on the overall acceptance of WSI and was important in the change management.

Computer-assisted diagnostics in cervical cytology

Computer assistance has the ability to reduce screening errors. In cervical cytology only two systems are available: BD FocalPoint™ (BD) utilizes algorithms for image recognition to analyze thin-layer specimens (Surepath) and conventional slides. The ThinPrep® imaging system (Hologic) is based on the densitometric measurement of nuclei and requires a thin-layer preparation. The BD FocalPoint™ system assigns specimens according to declining probability of an abnormality to one of six groups. A further option is location-guided screening (LGS) where the 15 fields of view which are most relevant are presented on a computerized microscope. Several studies indicate that this mode is at least equivalent to manual screening with conventional and surepath (SP) slides. For the ThinPrep® imaging system which only uses the LGS mode the majority of available studies found a significantly higher sensitivity for histologically confirmed grade 2 cervical intraepithelial neoplasia (CIN 2 +). However, most were retrospective or parallel studies. Both systems allow a significantly higher productivity but require a higher technical expenditure.

Comparison of Self-Collected and Clinician-Collected Materials for Cervical Cytology and Human Papillomavirus Genotyping: Analysis by Linear Array Assay

Objective: This study compared the usefulness of self-collected (SC) and clinician-collected (CC) materials for cervical cytology and human papillomavirus (HPV) genotyping. Study Design: Fifty women with previous positive cytology and who were undergoing regular checkups were included in the study. CC samples were collected using a Cervex-Brush Combi with liquid-based cytology. One month later, SC material was acquired using the Rovers Viba-brush vaginal sampler, and fixed at home. Thin-layer specimens were prepared from both samples and HPV status was analyzed using a linear array. Results: A total of 37/50 CC (74%) and 41/50 SC (82%) cases were positive for HPV. Pap tests identified high-grade squamous intraepithelial lesions in 11 (22%) and seven (14%) patients, low-grade squamous intraepithelial lesions in 19 (38%) and 16 (32%), atypical squamous cells of undetermined significance in 2 (4%) and 0 patients, and NILM (negative for intraepithelial lesion or malignancy) in 18 (36%) and 27 (54%) patients in the CC and SC groups, respectively. Conclusions: SC material had a lower positive cytology rate, but a higher HPV-positive rate than CC material. These results suggest that a combination of Pap and HPV tests on SC material may provide a diagnostic strategy with high sensitivity and specificity.

Supplementary transfer function of the transport of hydrogen in self-stressed metals

It is well established that the transport of hydrogen dissolved in metals is non-Fickian. This results from a non-zero partial volume of such hydrogen. Consequently, any gradient of hydrogen concentration in a metal causes its self-stress. Till now, the proposed transport equations taking stress into account have found analytical solutions only for quasi-equilibrium cases, and the transfer function (TF) spectroscopy is advocated as a unique technique for modelling the transport in question, and, in this way, estimating from experimental data the parameters that determine the kinetics of this process. In this paper, an additional TF – completing the set of previously proposed TFs – is presented and its applicability for estimating the values of the above parameters is numerically analysed with comparison to other analogous TFs. Although this TF is unique – being outwardly applicable also to the cases of foil and thin-layer specimens – it describes properly the transport in question solely in the case of membrane specimen.

Predictive value of gain of 3q for cervical dysplasia and potential utility in the clinical management of LSIL

5583 Background: Physicians need better tools for determining whether an LSIL will progress to HSIL or regress. Research demonstrates that the chromosome 3q26 region is found to be amplified in patients with cervical cancer and that the frequency of this 3q gain increases with dysplasia severity. The objective of this study was to demonstrate that 3q can be used as a risk stratification tool to identify patients likely to regress/progress. Methods: Slide-based, archival thin-layer specimens and longitudinal follow-up data for 52 patients (47 usable cases) originally diagnosed as LSIL were obtained from independent cytopathology laboratories. Slides were destained, then hybridized with a single-copy probe for the chromosome 3q26 region and a probe for the centromeric alpha-repeat sequence of chromosome 7, using standard FISH methods. Results: Of the 47 cases analyzed, 30 showed a negative FISH test result for a sensitivity of 92% (95% CI of 64, 100), specificity of 85% (95% CI of 69, 95) and a negative predictive value of 97% (95% CI of 83, 100). In a subset of cases a biopsy was obtained. Of the 32 cases with tissue diagnosis, 11 women had progressed to CIN2+, of which 10 were FISH positive; and 18 of 21 women with tissue diagnosis of ≤CIN1 were FISH negative, for a sensitivity of 91% (95% CI of 59, 100), specificity of 86% (95% CI of 64, 97) and a negative predictive value of 95% (95% CI of 74, 100). If the analysis is confined to the 36 cases for which follow-up of at least 12 months after the index LSIL was available, 26 showed a negative FISH test result for a sensitivity of 100% (95% CI of 48, 100), specificity of 84% (95% CI of 66, 95) and a negative predictive value of 100% (95% CI of 87, 100). Of the 22 cases with tissue diagnosis, 4 women had progressed to CIN2+, all FISH positive; and 16 of 18 women with ≤CIN1 were FISH negative, for a sensitivity of 100% (95% CI of 40, 100), specificity of 89% (95% CI of 65, 99) and a negative predictive value of 100% (95% CI of 79, 100). Conclusions: Analysis of 47 specimens demonstrated the ability of 3q gain to predict disease progression/regression in cytology samples. 3q gain can serve as a risk stratification tool for LSIL cases. [Table: see text]

Diagnostic utility of phosphatase and tensin homolog, β-catenin, and p53 for endometrial carcinoma by thin-layer endometrial preparations

For the current report, the authors examined the characteristic features of morphology and molecular biology of phosphatase and tensin homolog (PTEN), beta-catenin, and p53 immunocytochemistry in endometrial carcinoma by using thin-layer cytologic preparations. During a 6-month period, 120 endometrial samples were collected directly by using the Uterobrush, and thin-layer specimens were prepared. Immunocytochemical expression levels of PTEN, beta-catenin, and p53 were investigated by using 40 specimens of endometrial carcinoma (EC), and 30 specimens each of proliferative endometrium, secretory endometrium, and atrophic endometrium. For PTEN immunoreactivity, the a cutoff value of 50% PTEN expression appeared to be useful for the correct diagnosis of EC in endometrial cytology. For beta-catenin immunoreactivity, an increase in cytoplasmic and nuclear beta-catenin expression and a loss of beta-catenin expression appeared to be useful for the correct diagnosis of EC in endometrial cytology and may aid in the stratification of EC into low grade and high grade EC. For p53 immunoreactivity, the application of a cutoff score >or=4 for nuclear p53 expression appeared to be useful for the diagnosis of high-grade EC in endometrial cytology. Immunocytochemical findings from a combination of PTEN, beta-catenin, and p53, in addition to cytomorphologic features, appeared to be useful for the more accurate diagnosis of EC in endometrial cytology.

Utility of thin‐layer preparations in endometrial cytology: Immunocytochemical expression of PTEN, beta‐catenin and p53 for benign endometrial lesions

This article focuses on the characteristic features of morphology and molecular biology of PTEN, beta-catenin, and p53 immunocytochemistry in normal endometrium (proliferative, secretory, and atrophic) and endometrial glandular and stromal breakdown (EGBD) using thin-layer specimens. During a 6-month period, 120 endometrial samples were collected directly using the Uterobrush and a thin-layer specimen was prepared. Immunocytochemical expression of PTEN, beta-catenin, and p53 were investigated using 30 cases each of proliferative endometrium (PE), secretory endometrium (SE), atrophic endometrium (AE), and EGBD.PTEN expression of normal endometrial glandular epithelial cells changes with the hormonal status; PE produce very high expression, SE creates attenuation or disappearance of PTEN expression and AE diminished more in comparison with SE. PTEN expression of EGBD showed a tendency towards attenuation compared with PE, but showed high expression in comparison with SE and AE. As for the immunoreactivity of beta-catenin, in all phases (PE, SE, AE, and EGBD), it was observed in the cytoplasm of glandular epithelial cells, but not nuclei, and showed strong membranous staining. As for the p53 immunoreactivity, p53 positivity was not observed in the glandular epithelial cells in all phases (PE, SE, AE, and EGBD) with the exception of some metaplastic cells. The presence of p53 immunoreactivity of a weak, low ratio in metaplastic cells was unexpected. In the current study, the expression manner of PTEN, beta-catenin, and p53 immunocytochemistry was observed in the normal endometrium (PE, SE, and AE) and EGBD.

Liquid‐based endometrial cytology: cyto‐histological correlation in a population of 917 women

Liquid-based cytology, because of its capacity to reduce the obscuring factors and to provide thin-layer specimens, represents an opportunity to reevaluate endometrial cytology. In order to assess the utility of the liquid-based method in endometrial diagnosis, we evaluated its accuracy in comparison with histology. Nine hundred and seventeen women scheduled for hysteroscopy were enrolled in the study. After providing informed consent, all the women proceeded sequentially to hysteroscopy, endometrial cytology and then biopsy endometrial sampling. Cyto-histological correlations were possible in 519 cases (57%): in 361 (39%) cases the biopsy was inadequate, in 15 (2%) the cytology was inadequate, and in 22 (2%) both were inadequate. At biopsy 25 (3%) women had adenocarcinoma, 5 (1%) had adenomatous atypical hyperplasia and 21 (2%) had simple non atypical hyperplasia. At cytology two adenocarcinomas and one adenomatous atypical hyperplasia were underrated as atypical hyperplasias and as non-atypical hyperplasia; two simple non-atypical hyperplasias were reported as negative; and eight cases were false positive (non-atypical hyperplasia at cytology, negative at biopsy). In our population, the cytology provided sufficient material more often than biopsy (P < 0.04). Sensitivity was estimated at 96%, specificity at 98%, positive predictive value at 86% and negative predictive value at 99%. We concluded that endometrial cytology may be an efficient diagnostic method. It could be applied to selected patients solely or in association with ultrasonography. The combination of these two noninvasive procedures may improve their diagnostic accuracy and reduce unnecessary hysteroscopies, thereby producing benefits for women and society.

Enhancing Recovery of Endocervical Component on Gynecologic Cytology Specimens Processed by Thin-Layer Technology

To address the causes and report the corrective measures required for resolving the initial problem of high rates of cervical vaginal cytology specimens reported as having no endocervical component on SurePath (AutoCyte, Inc., Burlington, North Carolina, U.S.A.) liquid-based, thin-layer technology at an academic center cytology laboratory. Analysis of 511 cases lacking endocervical/transformation zone component out of 9,221 SurePath thin-layer gynecologic specimens processed in a one-year period. The study encompassed a review of sample collection techniques by physicians and nurses, specimen processing, cytologic features of endocervical/squamous metaplastic cells processed by the SurePath method and statistical analysis of endocervical cell recovery rates after implementation of corrective measures. Absence of endocervical/transformation zone component varied from an initial 18% in the first month to an average of 5.3% after corrective actions were implemented. Current rates of SurePath thin-layer specimens having no endocervical component are lower than those for conventional smears. Since SurePath was only recently introduced to the market, there are no previously published data addressing how to optimize the recovery of endocervical component on liquid-based, thin-layer specimens processed by this methodology.

Characterization of soluble and insoluble components in PM 2.5 and PM 10 fractions of airborne particulate matter in Kofu city, Japan

A systematic method combining water and diluted-acid extractions has been developed for the manifold evaluation of soluble and insoluble fractions in ambient aerosol. The pre-washed regenerated cellulose membrane filter was used as a collection medium of a low-volume air sampler. The collection time of 7–14 days was required to obtain the sample amounts enough for the systematic analysis. Simple and efficient extraction procedures using the filtration of water and 0.1 M hydrochloric acid were recommended in order to obtain the information about the dissolution behaviors of various elements in the aerosol. Soluble components in both the extracts were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and ion chromatography (IC). These extraction procedures were also preferred to prepare thin-layer specimens suitable to the succeeding X-ray fluorescence spectrometry (XRF) for insoluble components. Elemental compositions of the extraction residues were conveniently determined by the XRF calibrated with thin-layer standard specimens prepared with activated carbon. The determination of the 17 representative elements (Na, Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Zn, Br, Pb) in these three fractions from an aerosol sample was performed rapidly within 4 h. The proposed systematic method was applied to PM 2.5 and PM 10 aerosol samples collected in Kofu City, Central Japan, and the enrichment behaviors of various elements and their source apportionment such as soil, anthropogenic substances and vehicle exhaust particulates could be demonstrated by the present method.

Multi-element analysis of environmental samples by X-ray fluorescence spectrometry using a simple thin-layer sample preparation technique

A simple and rapid method was developed for the simultaneous multi-element (Na, Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Cd and Pb) analysis of environmental samples, such as vehicle exhaust particulates and atmospheric dust, by X-ray fluorescence (XRF) spectrometry using a simple thin-layer sample preparation technique. A portion of vehicle exhaust particulates or atmospheric dust CRM was suspended in a small volume of a dispersant on a hydrophilized poly(tetrafluoroethylene) (PTFE) membrane filter, dispersed by air blown from a pump and dried by IR irradiation. The resulting filter was sandwiched between two PTFE rings and a polycarbonate–dichloromethane solution was dropped onto the filter to obtain good resistance to X-ray irradiation. The XRF measurements of the specimens gave reasonable reproducibilities. Calibration graphs of analyte elements were obtained from XRF measurements of thin-layer standard specimens, prepared by impregnating activated carbon powder with standard solutions of the elements and then drying the powder. Analytical results obtained without matrix correction were in good agreement with the certified values.

Magnetooptical effects in bismuth-containing ferrite-garnet films

We present results of magnetooptical investigations of bismuth-containing ferrite-garnet films with the easy axis of magnetization parallel to the specimen surface. Measurements were conducted for incident light with energies in the range 1.5–3.2 eV for transverse [equatorial Kerr effect (EKE)] and for longitudinal [meridional intensity effect (MIE)] magnetizations of thin-layer specimens. It is shown that the EKE differs from zero when the films are opaque, and it is established that the EKE peak in the region ħΩ ∼ 2.8 eV increases with increasing bismuth concentration. For longitudinal magnetization, conditions for observing magnetooptical interference were realized. The experimental curves agree well with the theoretical ones.

X-ray diffractometric determination of sub-milligram amounts of hematite by a suspension-filtration method with silicon as internal standard

Silicon powders of four particle-size ranges were prepared from reagent-grade silicon by the Andreasen pipet method and elutriation. Thin-layer specimens were prepared by a suspension-filtration method using membrane filters. Silicon powder of 1.0–2.5 μm diameter is recommended as internal standard from the study of particle-size effects. Stable suspensions of silicon and hematite were prepared with a 0.05% dextrin solution. Relative standard deviation for determinations by the internal-standard method were < 9% for 100 μg of hematite in a mixed powder sample of 600 μg and < 5% for 400 μg of hematite in mixed samples of 900–1400 μg. Absorption effects in mixed powders are discussed.