Biomedical subjects

I G Charlton

Publications and source records attributed to I G Charlton.

11 recordsLinked to original sources

PubMed1999

Discrimination between benign and malignant melanocytic skin lesions by multivariate analysis, quantitative S-100 immunohistochemistry, nuclear morphometry and DNA cytometry.

OBJECTIVE: To determine whether combined quantitative immunohistochemistry of S-100, nuclear morphometry and DNA image cytometry improves discrimination between benign and malignant melanocytic skin lesions (MSLs). STUDY DESIGN: S-100 protein expression was measured in tissue sections of MSLs using an image cytometry system. Localized areas of high S-100 expression were used to identify regions in sequential, facing sections in which morphometric and cytometric features of nuclei, including DNA ploidy, were also measured. RESULTS: Malignant cases had significantly higher S-100 protein staining intensity, larger nuclei and greater DNA content (P < .05). High staining intensity for S-100 protein weakly correlated with variation in size of the mean nuclear area (P = .04) and DNA content (P = .03). Combining the features of nuclear area and DNA integrated optical density in areas of high-intensity staining for S-100 protein discriminated more accurately between 12 benign and 16 malignant areas than any of the features along (P = .0003). CONCLUSION: Combined multivariate quantitative immunohistochemical, morphometric and DNA cytometric analysis greatly improves discrimination between benign MSLs and malignant melanoma. Larger test sets are required to confirm the promising results of this initial study.

Cell Nucleus↗

PubMed1999

Influence of section thickness, mean nuclear diameter and nuclear crowding on DNA ploidy in histologic sections of melanocytic skin lesions.

OBJECTIVE: To determine the influence of section thickness, nuclear diameter (MND) and area percentage of nuclei (a measure of nuclear crowding) on histologic DNA ploidy assessed by image cytometry (ICM) of primary melanocytic skin neoplasms (MSNs). STUDY DESIGN: Initially a feasibility study was performed to determine if comparable DNA ploidy histograms could be obtained from cell disaggregates and tissue sections. Following this, DNA ICM was performed on Feulgen-stained tissue sections (4, 6, 8 and 10 microns thick) from 30 primary MSNs (20 benign, 10 malignant) with nuclear diameters from 5.6 to 8.6 microns. Area percentage of nuclei was assessed in all cases at all section thicknesses. RESULTS: The feasibility study produced comparable results for cytocentrifuge and tissue section preparations. For sectioned MSNs, DNA ploidy histograms from 4-micron sections had a higher coefficient of variation of the 2c peak than those from 6-, 8- and 10-micron sections. Ten-micrometer sections had marked overlapping of nuclei, and only small numbers of cells could be measured, giving inadequate results. MND and area percentage of nuclei did not have an important influence on the results. CONCLUSION: Adequate DNA ploidy profiles can be obtained by DNA ICM on 6- and 8-micron-thick histologic sections of MSNs, provided that a strict measurement protocol is followed.

Cell Count↗

PubMed1999

DNA ploidy and nuclear morphometry for the classification of dysplastic nevi.

OBJECTIVE: To examine the diagnostic value of DNA ploidy and nuclear morphometric features in sporadic dysplastic nevi as compared to those in compound nevi and melanoma. STUDY DESIGN: DNA ploidy profiles plus seven direct and three derived nuclear features were obtained in a series of 120 melanocytic skin neoplasms (30 dysplastic nevi [DN], 30 melanomas [MM], 60 compound nevi [CN]) and the results compared. RESULTS: DNA ploidy separated melanomas from benign melanocytic skin neoplasms with 96.5% accuracy in classifying the grouped cases. The derived nuclear shape factor Form PE and nuclear axis ratio were the most successful discriminants separating DN from MM but allowed only 73.3% correct classification of cases. Separation of DN from CN was best achieved using Form PE and mean nuclear area (74.4% correctly classified). Results from compound nevi in subjects < 25 years of age fell between those for DN and MM. CONCLUSION: Quantitative nuclear cytologic characteristics in sporadic dysplastic nevi span a range seen in common nevi through to those in thin melanomas. Cytologic changes in sporadic dysplastic nevi overlap those seen in other melanocytic skin neoplasms. Therefore, other reproducible morphometric features need to be assessed in order to further refine the histopathologic diagnosis of this entity.

Adult↗

PubMed1997

Exploring the possibility of DNA ploidy measurements in tissue sections using liver as a model.

OBJECTIVE: To evaluate DNA image cytometry (ICM) in tissue sections, human and rat liver was used as a model. These tissues have distinct DNA ploidy histograms of mainly diploid (human) and predominantly tetraploid (rat) plus octaploid nuclei. STUDY DESIGN: Section thickness varied from 4 to 12 microns in rat liver and 4 to 10 microns in human liver, in steps of 2 microns. The measurements were made using a commercially available ICM system, strictly following a measurement protocol. RESULTS: Four-micrometer-thick sections gave very broad histograms. Six-micrometer-thick sections gave better results, but with increasing DNA PLOIDY (> 4c), modal peaks were broad and increasingly shifted to the left. Sections of 8-10 microns gave linear results of the 2c, 4c and 8c peaks and also the narrowest peaks. The 12-micron sections of rat liver were more difficult to measure, and the results were not improved. CONCLUSION: The 8-micron sections gave the best results and were easiest to measure. These results are promising, but since liver is a fairly simple model, further studies are required to elucidate whether DNA ploidy measurements can be performed reliably on tissue sections of human tumors.

Animals↗

PubMed1996

Further testing of the value of a measurement protocol for DNA ploidy studies using image cytometry. Comparison of results obtained from cytologic and paraffin section preparations.

OBJECTIVE: To apply DNA image cytometry (ICM) to 53 tissue sections of breast cancer and skin melanomas. STUDY DESIGN: DNA ICM was performed on 6-microns-thick sections with a commercially available ICM system, strictly following a previously developed measurement protocol. The histograms were classified according to Auer. RESULTS: In 48 of the 53 cases (90.6%, kappa = .84) there was complete agreement in the Auer class. Discrepancies were one class 1-2 and one class 1-3 shifts (cytocentrifuge samples class 1); one case was class 2 in the section and class 3 in the cytocentrifuge sample, and two cases were class 4 in the cytologic and class 3 in the histologic specimen. CONCLUSION: By paying careful attention to the measurement protocol and technical quality of the material, for certain tumors with relatively small nuclei and limited nuclear overlap, reliable DNA ICM results can be obtained in most cases from 6-microns-thick tissue sections that are comparable to those from single-cell preparations.

Breast Neoplasms↗

PubMed1996

Testing the value of a measurement protocol for DNA image cytometry and comparing different cytologic preparations.

OBJECTIVE: To analyze the influence of measuring parameters on the quality of DNA histograms, and to compare the results of DNA image cytometry (ICM) and flow cytometry (FCM). STUDY DESIGN: Material from 20 breast cancer cases was analyzed. The protocol for ICM analyzed (1) measuring system and image analysis parameters, (2) the quality of fixation, and (3) the presence of cytoplasm around nuclei. In Feulgen-stained slides (both fresh imprints and cytocentrifuge preparations) at least 200 nuclei were examined using a commercially available ICM system. DNA FCM on disaggregates was performed, also. RESULTS: Strict adherence to the protocol gave reliable DNA ploidy profile results. In contrast, deviations from the protocol gave very broad histograms. With the protocol, similar results were found for imprints and cytocentrifuge samples. Duplicate "blind" assessments were highly reproducible. DNA indices measured by FCM and ICM (on cytocentrifuge samples) correlated highly as well. CONCLUSION: With the protocol used, DNA ploidy profiles obtained by ICM from fresh imprints and cytocentrifuge disaggregate cell preparations were comparable.

Breast Neoplasms↗

PubMed1995

Image analysis DNA densitometry measurements on complete and partial hydatidiform mole and nonmolar products of conception.

Most spontaneous first trimester abortions have an abnormal karyotype, some being triploid; the latter are said to show characteristic histological changes, including focal villous hydropic change, focal trophoblast hyperplasia, cisternal cavitation of larger villi, irregular outline to villi, and trophoblast inclusions. To date, DNA-ploidy profiles have been derived from flow cytometry and cytogenetic karyotyping, both methods being time-consuming and expensive. This study has assessed DNA ploidy on products of conception using a simple video image analysis system. It is concluded that diploid, triploid, aneuploid, and hyperdiploid states can be ascertained on archival paraffin-embedded material using interactive image analysis morphometry. However, the stated histological criteria for triploidy (which has previously been equated with partial mole) appear to be unreliable, with only three of eight histological partial moles having this DNA pattern. In addition, there were six diploid, five triploid, seven hyperdiploid, and two aneuploid DNA ploidy profiles in the spontaneous nonmolar pregnancies. We found that of the 11 complete moles, five were aneuploid and six were hyperdiploid, with none being either diploid or triploid. This finding is contrary to the commonly held view that all complete moles have a diploid DNA profile.

Abortion, Missed↗

PubMed1993

Malignant potential of aneuploid pancreatic endocrine tumours.

Evaluation of the malignant potential of pancreatic endocrine tumours is difficult by histological criteria alone. Nuclear deoxyribonucleic acid (DNA) cytometric analysis can provide significant prognostic and biological information in a number of solid human tumours. Thus, the DNA profiles and nuclear parameters of 39 patients with pancreatic endocrine tumours diagnosed from 1969 to 1989 were studied, using computerized video image analysis. Of the 39 patients with tumours, 27 cases did not have evidence of metastatic disease at the time of investigation. The majority of these (N = 21) showed a diploid profile. Five were aneuploid and one was tetraploid. In the 12 tumours that proved malignant, three had tissue of both primary tumour and the metastases analysed; six had material only from the primary tumour, although metastatic disease was established clinically; and another three only had tissue from the secondary tumour studied. The majority of the malignant cases were aneuploid (N = 7); three were diploid; one showed a diploid primary but an aneuploid secondary, and one showed a hyperdiploid pattern. The percentage of nuclei with a DNA content greater than 5N (5CER) did not seem to contribute further to the assessment nor did the means of the nuclear areas and shape factors. It appears that ploidy studies may be useful in predicting malignant potential of pancreatic endocrine tumours. There is a high rate of immunostaining for insulin by benign pancreatic endocrine tumours and this may be a useful adjunct to distinguish them from their malignant counterparts. However, there is no statistically significant correlation between the expression of various hormones and the DNA ploidy of tumour cells.

Aneuploidy↗

PubMed1991

Nuclear DNA profiles in primary melanomas and their metastases.

DNA-aneuploid primary melanomas are said to show a greater propensity to metastasize than those without an aneuploid profile. A higher aneuploid rate has also been reported in metastatic melanomas than in primary lesions. The ploidy profile was determined of 26 primary melanomas and their first subsequent secondaries on Feulgen-stained sections from routinely processed material using a computerized video image-analysis system. In 18 of 26 cases, both primary and secondary tumor showed similar corresponding DNA patterns. These were aneuploid in 13 of 18 of the cases. A hyperdiploid pattern was present in one case in both the primary and its metastasis, and a diploid pattern was seen in four cases. There were only eight cases in which a disparity between the nuclear ploidy profile in the primary and secondary tumor was evident. Although the results suggest that ploidy studies are not useful for predicting the metastatic potential of a primary melanoma, the maintenance of similar DNA profiles in the metastases in most of these cases was interesting in regard to tumor biology.

Aneuploidy↗

PubMed1991

Comparative ploidy studies using cytological and paraffin section preparations.

The ploidy profiles of benign and malignant tumours can be obtained using image analysis. However, the results of ploidy studies have varied according to the type of specimen used. We compared the ploidy profiles of paraffin embedded thin sections, cytospin preparations of disaggregated cells, and cytological smears from the same specimen as defined by image analysis. Ten benign breast lesions, 10 breast carcinomas and 10 malignant melanomas were investigated in this way. Preparations stained by the Feulgen technique were examined using the MD20 video image analysis densitometry system. Ploidy profiles were obtained by measuring the integrated optical density of at least 200 nuclei. By paying proper attention to the quality of fixation and presence or absence of cytoplasm around cells, comparable results were found for all preparations in each case. We therefore conclude that if careful attention is paid to the technical quality of the material, reliable ploidy results can be obtained by image analysis.

Aneuploidy↗

PubMed1991

Nuclear ploidy in neuroendocrine neoplasms of the larynx.

Seventeen neuroendocrine neoplasms of the larynx were examined for DNA ploidy. Twelve tumours were atypical carcinoids, four paragangliomas and one a small cell neuroendocrine carcinoma. Seven atypical carcinoids were aneuploid, one diploid and one tetraploid, with metastasis being aneuploid. In three cases only skin metastases were available for study, which were aneuploid. The small cell neuroendocrine carcinoma was aneuploid. Two of the paragangliomas were aneuploid and two diploid. Like other sites, neuroendocrine neoplasms of the larynx have a high rate of aneuploidy. Determination of DNA ploidy did not provide useful diagnostic or prognostic information.

Aged↗