Automated detection of cancer cells in effusion specimens by DNA karyometry

Background

The average sensitivity of conventional cytology for the identification of cancer cells in effusion specimens is only approximately 58%. DNA image cytometry (DNA‐ICM), which exploits the DNA content of morphologically suspicious nuclei measured on digital images, has a sensitivity of up to 91% for the detection of cancer cells. However, when performed manually, to our knowledge to date, an expert needs approximately 60 minutes for the analysis of a single slide.

Methods

In the current study, the authors present a novel method of supervised machine learning for the automated identification of morphologically suspicious mesothelial and epithelial nuclei in Feulgen‐stained effusion specimens. The authors compared this with manual DNA‐ICM and a gold standard cytological diagnosis for 121 cases. Furthermore, the authors retrospectively analyzed whether the amount of morphometrically abnormal mesothelial or epithelial nuclei detected by the digital classifier could be used as an additional diagnostic marker.

Results

The presented semiautomated DNA karyometric solution identified more diagnostically relevant abnormal nuclei compared with manual DNA‐ICM, which led to a higher sensitivity (76.4% vs 68.5%) at a specificity of 100%. The ratio between digitally abnormal and all mesothelial nuclei was found to identify cancer cell–positive slides at 100% sensitivity and 70% specificity. The time effort for an expert therefore is reduced to the verification of a few nuclei with exceeding DNA content, which to our knowledge can be accomplished within 5 minutes.

Conclusions

The authors have created and validated a computer‐assisted bimodal karyometric approach for which both nuclear morphology and DNA are quantified from a Feulgen‐stained slide. DNA karyometry thus increases the diagnostic accuracy and reduces the workload of an expert when compared with manual DNA‐ICM.

An automated procedure for the detection of cancer cells in effusion specimens is presented. It provides a sensitivity of 76.4% and a specificity of 100% at a time effort for clinicians of approximately 5 minutes per specimen.

High Proportion of Nuclear Phenotype Identifies Aggressive Cutaneous Squamous Cell Carcinoma

OBJECTIVE

To develop a quantitative histopathology algorithm to predict which patients with cutaneous squamous cell carcinoma (cSCC) were likely to experience recurrence or metastases.

STUDY DESIGN

This retrospective study of cSCC lesions compared patients with aggressive disease (n = 40) and those with nonaggressive disease (n = 35). Based on a previous study using nuclear karyometry, we determined that aggressive lesions had a high proportion of a specific nuclear phenotype. The proportion of those nuclei was used to derive an aggressiveness score for each lesion. The mean age of patients was similar in both groups, as were the locations of index lesions.

RESULTS

The mean aggressiveness scorefor cases with aggressive lesions was 0.60 ± 0.21 and was 0.28 ± 0.35 for those with nonaggressive lesions. The overall accuracy in properly characterizing lesions was 72%. The area under the receiver operating characteristic curve was 0.80 ± 0.05. In general, the aggressive nuclear phenotype is represented by elevated levels of chromatin clumps and short linear segments of dark chromatin/intense pixels.

CONCLUSION

These data suggest that discriminant functions may be utilized to distinguish between aggressive and nonaggressive lesions at the time of diagnosis.

[Basic aspects of medical genetics]

The human genome consists of 23 pairs of chromosomes that contain 20 000-25 000 genes. Genetic disorders can be caused by different mechanisms, and therefore the confirmation of a suspected diagnosis requires knowledge of the underlying defect, so that the correct test can be applied. Monogenic diseases are caused by disturbances in a single gene, and currently only targeted diagnostic testing is available following a specific clinical suspicion. Chromosomal disorders usually involve multiple genes, so that the symptoms are often less specific. Specialists in Medical Genetics FMH are trained in creating a clinical genetic differential diagnosis, requesting the according laboratory test, interpretating the results and providing expert genetic counseling in presymptomatic and prenatal diagnosis. In Switzerland, specific legal principles and ethical guidelines must be taken into account.

Evaluation of ICSI-Selected Epididymal Sperm Samples of Obstructive Azoospermic Males by the CKIA System

The objective of this study was to evaluate nuclear normality in intracytoplasmic sperm injection (ICSI)-selected epididymal sperm from obstructive azoospermic (OA) patients. We evaluated whether the selection criteria used in routine ICSI (morphology and motility at a magnification of 400x) is adequate for selecting "normal" sperm from epididymal samples. Surgically retrieved spermatozoa from the caput epididymis of 15 OA patients and ejaculated sperm samples from 9 normospermic donors were evaluated with a DNA-specific stain (Feulgen) and in combination with the computerized karyometric image analysis (CKIA) system. Original (unselected) samples and ICSI-selected sperm were compared in donor and patient samples. In the original fraction, a larger variation in almost all measured parameters was found in epididymal sperm than in ejaculated sperm. After sperm selection, the morphometry was comparable between epididymal and ejaculated sperm. However, for those parameters related to the DNA stainability and chromatin texture (nuclear condensation), significant differences between patients and donors were observed. This result suggests that the size and form of the sperm do not necessarily hold similar internal structures. Thus, the frequency of "normal" sperm significantly increased after ICSI selection, but the improvement was more marked in donor than in OA patients' samples. In conclusion, at least a twofold increase in the number of normal spermatozoa was achieved after ICSI selection. The heterogeneity in the stainability and chromatin condensation of epididymal samples from OA patients indicates that some of the selected spermatozoa have a hypocondensed or hypercondensed chromatin. Even in the best of donor cases, no more than 55% of the selected sperm scored normal with CKIA, indicating that the present routine ICSI selection criteria are not sufficient for selecting normal condensed nuclei.

Differential diagnosis of follicular tumor by expert systems based on a set of quantitative features of thyrocyte nuclei and aggregates

OBJECTIVE

To develop expert systems for classification of follicular thyroid tumor at a preoperative stage.

STUDY DESIGN

Fine needle aspiration biopsy of the thyroid gland with a histologic conclusion of follicular cancer and follicular adenoma were the object of the morphometric study. General sample size was 4500 nuclei and 3000 aggregates.

RESULTS

Quantitative regularities of pathologic changes in thyrocyte nuclei and aggregates in follicular cancer and follicular adenoma were revealed. Threshold values and weighting coefficients of quantitative features of thyrocyte nuclei and aggregates characterizing cancer made the basis of the two expert systems. Expert systems included standard 2-D S-matrix containing threshold values of nuclei and aggregates in cancer and their weighting coefficients as well as 1-D scientific X-matrix designed for filling with quantitative features of the studied object. The diagnosis was verified by the value of a diagnostic index by means of comparing feature values in the corresponding elements of S- and X-matrices. After that, a diagnostic index was calculated taking into account the features' weighting coefficient.

CONCLUSION

The developed expert systems based on a set of quantitative features of thyrocyte nuclei and aggregates will allow assessing the malignant potential of a follicular thyroid tumor at a preoperative stage.

Pivotal karyometric measurements in different types of cardiomyopathic morphology: study of hearts explanted from transplant recipients

BACKGROUND

Morphometric studies based on the measurement of cardiocyte nuclei have focused on progressive hypertrophy rather than shape, which is a deciding factor for the diagnosis of hypertrophy in myocardial diseases. The aim of this research was to demonstrate how the digital morphology of cardiocyte nuclei change correlated with the type of myocardial pathology.

MATERIALS AND METHODS

The study groups encompassed 7 hearts with dilated cardiomyopathy (DCM) and 8 hearts with ischemic heart disease (IHD) which were explanted. A comparative group consisting of myocardial hypertrophy was contrasted with a control group of donor heart fragments. Cardiocyte nuclei were evaluated morphometrically on histologic slides. We calculated the nuclear area, length, breadth, perimeter, roundness, elongation, fullness factors, and nuclear chromatin mean gray level. The results were subjected to discriminant analysis.

RESULTS

All karyometric measurements analyzed by backward discriminant analysis showed only 2 powerful factors: nuclear breadth and chromatin mean gray level. The Mahalanobis distance showed the proximity of control and hypertrophy groups, whereas differences between IHD and DCM were nonsignificant.

CONCLUSION

The lack of karyometric differences between IHD and DCM suggested a common morphologic response for long-lasting progressive injury. The main morphologic differences were dependent on nuclear chromatin activity/stainability and nuclear breadth, suggesting darker and thinned nuclei in normal and adaptative stages and irregular brighter nuclei in cardiomyopathies.

Karyometry: correction algorithm for differences in staining

OBJECTIVE

To describe an algorithm that allows the correction of differences in staining of histopathologic sections while preserving chromatin texture.

STUDY DESIGN

In order to preserve the texture of the nuclear chromatin in the corrected digital imagery, it is necessary to correct the images pixel for pixel. This is accomplished by mapping each pixel's value onto the cumulative frequency distribution of the data set to which the image belongs, to transfer to the cumulative frequency distribution of the data set serving as standard and to project the intersection down onto the pixel optical density scale for the corrected value.

RESULTS

Feature values in the corrected imagery, for the majority of features used in karyometry, are between < 1% and a few percent of the feature values in standard imagery. For some higher-order statistical features involving multiple pixels, sensitivity to a shift in the cumulative frequency distribution may exist, and a secondary small correction by a factor may be required.

CONCLUSION

The correction algorithm allows the elimination of the effects of small staining differences on karyometric analysis.

Automatic segmentation of cell nuclei in bladder and skin tissue for karyometric analysis

OBJECTIVE

To automatically segment cell nuclei in histology images of bladder and skin tissue for karyometric analysis.

STUDY DESIGN

The 4 main steps in the program were as follows: median filtering and thresholding, segmentation, categorizing and cusp correction. This robust segmentation technique used properties of the image histogram to optimally select a threshold and create closed 4-way chain code nuclear segmentations. Each cell nucleus segmentation was treated as an individual object of which the properties of segmentation quality were used for criteria to classify each nucleus as: throw away, salvageable or good. An erosion/dilation procedure and rethresholding were performed on salvageable nuclei to correct cusps.

RESULTS

Ten bladder histology images were segmented both by hand and using this automatic segmentation algorithm. The automatic segmentation resulted in a sensitivity of 76.4%, defined as the percentage of hand-segmented nuclei that were automatically segmented with good quality. The median proportional difference between hand and automatic segmentations over 42 nuclei each with 95 features used in karyometric analysis was 1.6%. The same procedure was performed on 10 skin histology images with a sensitivity of 83.0% and median proportional difference of 2.6%.

CONCLUSION

The close agreement in karyometric features with hand segmentation shows that automated segmentation can be used for analysis of bladder and skin histology images.

Progression of skin lesions from normal skin to squamous cell carcinoma

OBJECTIVE

To assess the changes in the nuclear chromatin pattern concomitant with progressive sun damage in skin biopsies ranging from sun-exposed, normal-appearing skin to squamous cell carcinoma (SCC).

STUDY DESIGN

Biopsies were taken from 140 cases with sun-exposed but histopathologically normal skin, from 20 cases visually assessed as pre-actinic keratosis (pre-AK) or early AK, from 30 cases of AK, and from 21 cases of SCC. A total of 21,094 nuclei were recorded from these biopsies. High-resolution digital imagery was recorded, and features descriptive of the nuclear chromatin pattern were computed. Both supervised learning and unsupervised learning algorithms were employed to derive progression plots.

RESULTS

With increased sun exposure, the proportion of nuclei exhibiting changes in the nuclear chromatin pattern rises notably. Using karyometry, no significant differences could be substantiated between nuclei collected from early AK sites and AK lesions. Cases of SCC fell into 2 distinct groups. A larger group (approximately 66.7% of cases) had characteristics similar to AK. A smaller group (approximately 33.3% of cases) represented much more progressed lesions.

CONCLUSION

Karyometric assessment can provide a numeric measure of progression for sun damage and of the deviation from normal in both AK and SCC lesions.

Limits of detection of chemopreventive efficacy: karyometry of skin biopsies

OBJECTIVE

This study was designed to establish estimates of the smallest effects due to chemopreventive intervention detectable by karyometry in skin biopsies.

METHODS

Estimates of the smallest change of statistical significance and estimates of the power of the test were derived for several key features descriptive of the distribution of nuclear chromatin. Results from triplicate biopsies from the same case were used to provide estimates of the within-case, biopsy-to-biopsy variance.

RESULTS

Generally, a change in feature value due to chemopreventive intervention can be statistically secured when it amounts to 5% to 10%. In clinical trials where matched baseline and end of study biopsies from the same cases are available, paired comparison ANOVA can detect a 2% change on samples of 25 cases. Establishing efficacy in individual cases requires a change in feature values on the order of 10% to 15%.

CONCLUSIONS

Karyometry provides a sensitive, quantitative method for the assessment of efficacy of chemoprevention. The effects of within-case, biopsy-to-biopsy variance need to be considered only in the evaluation of individual cases and are on the order of 5% in skin biopsies.

Potential role of nuclear appearance in pathologic recognition and delimitation of sessile serrated polyps of the colon: a karyometric study

OBJECTIVE

To estimate the extent to which surgical pathologists can rely on abnormal nuclear appearance to recognize sessile serrated adenoma (SSP) and to define its extent.

STUDY DESIGN

Digitized images of nuclei of superficial crypt cells from SSPs, banal hyperplastic polyps (BHPs), tubular adenomas (TAs) and normal colonic mucosa (N) in surgical pathology specimens were analyzed for size, shape, area, optical density (summed and average) and 22 Markovian texture characteristics.

RESULTS

Statistical classification functions correctly distinguished TA from N nuclear image profiles in 93.3% of cases, SSP from N in 70.0% and BHP from N in 74.1%. SSP nuclear feature vectors were less effectively separated from N than BHP and TA on discriminant analysis of the combined data set, and correct classification was achieved in 79.6% of TAs, 53.5% of SSPs and N and 64.2% of BHPs.

CONCLUSION

Karyometry distinguished stained nuclei of TAs, but had limited ability to separate nuclei of SSP from those of N and BHP. This suggests that the pathologist attempting to diagnose or delimit the margins of an SSP will find nuclear appearances less helpful than when examining a TA.

Chromatin phenotype karyometry can predict recurrence in papillary urothelial neoplasms of low malignant potential

BACKGROUND

A preceding exploratory study (J. Clin. Pathol. 57(2004), 1201-1207) had shown that a karyometric assessment of nuclei from papillary urothelial neoplasms of low malignant potential (PUNLMP) revealed subtle differences in phenotype which correlated with recurrence of disease.

AIM OF THE STUDY

To validate the results from the exploratory study on a larger sample size.

MATERIALS

93 karyometric features were analyzed on haematoxylin and eosin-stained sections from 85 cases of PUNLMP. 45 cases were from patients who had a solitary PUNLMP lesion and were disease-free during a follow-up period of at least 8 years. The other 40 were from patients with a unifocal PUNLMP, with one or more recurrences in the follow-up. A combination of the previously defined classification functions together with a new P-index derived classification method was used in an attempt to classify cases and identify a biomarker of recurrence in PUNLMP lesions.

RESULTS

Validation was pursued by a number of separate approaches. First, the exact procedure from the exploratory study was applied to the large validation set. Second, since the discriminant function 2 of the exploratory study had been based on a small sample size, a new discriminant function was derived. The case classification showed a correct classification of 61% for non-recurrent and 74% for recurrent cases, respectively. Greater success was obtained by applying unsupervised learning technologies to take advantage of phenotypical composition (correct classification of 92%). This approach was validated by dividing the data into training and test sets with 2/3 of the cases assigned to the training sets, and 1/3 to the test sets, on a rotating basis, and validation of the classification rate was thus tested on three separate data sets by a leave-k-out process. The average correct classification was 92.8% (training set) and 84.6% (test set).

CONCLUSIONS

Our validation study detected subvisual differences in chromatin organization state between non-recurrent and recurrent PUNLMP, thus allowing a very stable method of predicting recurrence of papillary urothelial neoplasms of low malignant potential by karyometry.

Karyometry of breast epithelial cells acquired by random periareolar fine needle aspiration in women at high risk for breast cancer

OBJECTIVE

To establish whether karyometry was likely to detect change in the proportion of abnormal cells in random periareolar fine needle aspiration (RPFNA) specimens from high-risk women in a 6-month prevention trial with an aromatase inhibitor.

STUDY DESIGN

Papanicolaou-stained ThinPrep slides of RPFNA samples from 11 of 42 women were digitally recorded at high resolution, with 200 cells measured per slide, at baseline (BL) and at the end of study (ES) after 6 months. The nuclear chromatin pattern characteristics were assessed by multivariate analytic techniques; determination of nuclear abnormalities was performed and cells that showed expression of abnormality were identified.

RESULTS

The BL FNA samples contain approximately 90% cells with a chromatin pattern as expected in a normal cell population. A small subpopulation of cells had deviations from normal. At ES the proportion of these cells was reduced, to a statistically significant degree,from < 10% to 2-5%.

CONCLUSION

Nuclear karyometry is a promising technique for characterizing the proportion of cells deviating from normal in cytologic specimens and should be explored further as an intermediate endpoint in prevention trials.

Accelerated nuclei preparation and methods for analysis of histone modifications in yeast

The continuing identification of new histone post-translational modifications and ongoing discovery of their roles in nuclear processes has increased the demand for quick, efficient, and precise methods for their analysis. In the budding yeast Saccharomyces cerevisiae, a variety of methods exist for the characterization of histone modifications on a global scale. However, a wide gap in preparation time and histone purity exists between the most widely used extraction methods, which include a simple whole cell extraction (WCE) and an intensive histone extraction. In this work we evaluate various published WCE buffers for their relative effectiveness in the detection of histone modifications by Western blot analysis. We also present a precise, yet time-efficient method for the detection of subtle changes in histone modification levels. Lastly, we present a protocol for the rapid small-scale purification of nuclei that improves the performance of antibodies that do not work efficiently in WCE. These new methods are ideal for the analysis of histone modifications and could be applied to the analysis and improved detection of other nuclear proteins.

Analysis of karyometric variables in spontaneously occurring canine mammary tumors

OBJECTIVE

To study alteration in karyometric variables to distinguish benign from malignant canine mammary tumors.

STUDY DESIGN

Formalin-fixed, paraffin-embedded tissue sections from 16 cases of canine mammary tumors were stained with hematoxylin-eosin and analyzed for mean nuclear area, mean nuclear perimeter and shape factor. The morphometric descriptors were then correlated with conventional histologic diagnosis.

RESULTS

On Mann-Whitney U-test, nuclear variables, that is, mean nuclear area and mean nuclear perimeter, revealed significant difference between malignant and benign groups (p < 0.01), while shape factor showed significant difference at p < 0.05. All morphometric descriptors showed significant correlation with each other and with histopathologic diagnosis. Contrary to expectations, shape factor was lower in benign compared to malignant tumors. In benign mammary tumors, the highest mean nuclear area and perimeter were 39.59 +/- 10.34 microm2 and 25.39 +/- 4.14 microm, respectively, for fibroadenoma; and in malignant tumors the highest mean nuclear area and perimeter were 48.44 +/- 12.89 microm2 and 27.36 +/- 4.31 microm, respectively, for papillary adenocarcinoma.

CONCLUSION

This study provides insight into the alterations in karyometric variables in canine mammary tumors. Mean nuclear area and perimeter appear to have potential to differentiate benign and malignant canine mammary tumors.

Subcortical nuclei volumetry in idiopathic generalized epilepsy

PURPOSE

The exact anatomic and neurophysiologic correlates of idiopathic generalized epilepsy (IGE) in humans are still not well understood, although the thalamus has frequently been invoked as the crucial structure in the generation of primary generalized seizures. The few in vivo magnetic resonance (MR)-based studies in IGE patients suggest an altered cortical/subcortical gray matter ratio, but with no evidence of structural alterations of the thalamus. In this study, we sought to determine the volumes of the other subcortical structures.

METHODS

The volumes of the caudate nucleus, putamen, pallidum as well as the thalamus were each determined in both hemispheres in 11 patients with various IGE syndromes, normalized for whole-brain volumes and then compared with 15 age-matched controls.

RESULTS

No differences were noted in thalamic volumes, confirming previous reports. However, smaller subcortical volumes were noted in the IGE patients (p < 0.009), mainly due to smaller putamen bilaterally (p < or = 0.015).

CONCLUSIONS

It is speculated that the presence of discrete frontal dysfunction, as noted in neuropsychological studies in IGE patients, indirectly supports our results because the putamen projects predominantly to the frontal cortex. Larger studies with more homogeneous patient populations are needed to determine the robustness of these findings and whether they are specific for particular IGE syndromes.

Karyometry in the early detection and chemoprevention of intraepithelial lesions

The ideal chemopreventive agent targets pre-neoplastic changes and intraepithelial neoplasia, preventing progression over time without notable side effects. Assessment of success of chemopreventive intervention in the short and medium term remains a challenge, and in this review the suggestion is investigated that karyometric measurements constitute suitable markers of chemopreventive efficacy. Karyometry provides the sensitivity required to detect small differences amidst relatively high biological variability. It can help establish progression curves of intraepithelial neoplasia (IEN) to invasive cancer, and thus detect chemopreventive effects. Such effects can be observed in two ways, at the group level (intervention vs. placebo), and at the case (or patient) level. The latter is more difficult to establish, necessitating the development of specialised statistical methods. Analysis of between-case and within-case heterogeneity can reveal useful information about cancer progression and prevention. We suggest that karyometry can objectively quantify IEN progression, providing a framework for statistically securing chemopreventive effects. It can act as an integrating biomarker by detecting chemopreventive activity even when the mechanism for a given progression pathway is unknown, or when multiple pathways exist. The sensitivity of karyometric detection can help optimise the design of clinical trials of novel chemopreventive agents by decreasing trial duration and/or sample size.

Karyometry of infiltrating breast lesions

OBJECTIVE

To characterize nuclei from well-differentiated, moderately differentiated and poorly differentiated lesions of invasive breast cancer by karyometry and to test the hypothesis that these diagnostic categories form homogeneous sets.

STUDY DESIGN

Histopathologic sections from 6 cases of well-differentiated, 11 cases of moderately differentiated and 17 cases of poorly differentiated ductal carcinomas were digitally recorded. From each case 100 nuclei were segmented and analyzed by karyometry. A discriminant analysis was performed, and nuclear and lesion signatures were computed. The nonsupervised learning algorithm P-index was applied. A progression curve per diagnostic category based on mean nuclear abnormality and a discriminant function score was derived.

RESULTS

The well-differentiated lesions formed a homogeneous set, but both the moderately and poorly differentiated lesions showed 2 significantly different subpopulations with nuclei of substantially different nuclear abnormality and progression.

CONCLUSION

The visual histopathologic diagnostic assessment of these lesions was based on an evaluation of both tissue architectural criteria and nuclear criteria. Here, only the pattern of nuclear chromatin was evaluated. Cases belonging to the same diagnostic category as assessed by their differentiation may be further characterized by the extent to which the nuclei deviate from normal. There was substantial case-to-case heterogeneity in these invasive lesions.

Karyometry detects subvisual differences in chromatin organisation state between non-recurrent and recurrent papillary urothelial neoplasms of low malignant potential

AIM

To analyse nuclear chromatin texture in non-recurrent and recurrent papillary urothelial neoplasms of low malignant potential (PUNLMPs).

MATERIALS

Ninety three karyometric features were analysed on haematoxylin and eosin stained sections from 20 PUNLMP cases: 10 from patients with a solitary PUNLMP lesion, who were disease free during at least eight years' follow up, and 10 from patients with unifocal PUNLMP, one or more recurrences being seen during follow up.

RESULTS

Kruskal-Wallis analysis was used to search for features showing significant differences between recurrent and non-recurrent cases. Significance was better than p<0.005 for more than 20 features. Based on significance, six texture features were selected for discriminant analysis. Stepwise linear discriminant analysis reduced Wilk's lambda to 0.87, indicating a highly significant difference between the two multivariate data sets, but only modest ability to discriminate (70% correct case classification). A box sequential classifier was used based on data derived from discriminant analysis. The classifier took three classification steps and classified 19 of the 20 cases correctly (95% correct case classification). To determine whether significant case grouping could also be obtained based on an objective criterion, the merged data sets of non-recurrent and recurrent cases were submitted to the unsupervised learning algorithm P-index. Two clusters were formed with significant differences. The subsequent application of a Cooley/Lohnes classifier resulted in an overall correct case classification rate of 85%.

CONCLUSIONS

Karyometry and multivariate analyses detect subvisual differences in chromatin organisation state between non-recurrent and recurrent PUNLMPs, thus allowing identification of lesions that do or do not recur.

Karyometry detects subvisual differences in chromatin organization state between cribriform and flat high-grade prostatic intraepithelial neoplasia

This digital texture analysis-based study evaluates the chromatin organization state in flat and cribriform high-grade prostatic intraepithelial neoplasia (PIN), in the adjacent normal looking secretory epithelium and in the co-occurring adenocarcinoma. Digital texture analysis (karyometry) was carried out on hematoxylin and eosin-stained sections from 24 radical prostatectomy specimens with high-grade PIN (12 with flat and 12 with cribriform architectural pattern, respectively) and cancer. Quantification was also conducted on the normal looking secretory epithelium. Discriminant analysis and the nonsupervised learning algorithm P-index were used to identify suitable subsets of features useful for the discrimination and classification of pathological groups and to explore multivariate data structure in the pathological subgroups. The average nuclear abnormality increases monotonically from the histologically normal appearing secretory epithelium to high-grade PIN and to adenocarcinoma. The nuclei from the so-called perimeter compartment of the flat high-grade PIN lesions show a higher nuclear abnormality compared to the nuclei of the cribriform high-grade PINs. Discriminant analysis shows that flat and cribriform high-grade PINs fall into two populations. Processing by the nonsupervised learning algorithm P-index revealed the existence of three well-defined, distinct subpopulations of nuclei of different chromatin phenotype. In the flat high-grade PIN lesions the proportions of nuclei in the three subpopulations are 16.5% (low abnormality), 25.0% (mid abnormality) and 58.5% (high abnormality), respectively. In the cribriform high-grade PIN lesions, 100% of the nuclei are in the mid-abnormality subpopulation. These differences are also discernible in the co-occurring adenocarcinoma and the histologically normal appearing secretory epithelium. To conclude, karyometry and statistical analysis detect the existence of distinct cell subpopulations of different chromatin packaging and phenotype, with the nuclei from the flat high-grade PIN lesions, adjacent normal looking epithelium and co-occurring adenocarcinoma expressing a greater nuclear abnormality than in the specimens with cribriform high-grade PIN.

Application of multilevel models to morphometric data. Part 1. Linear models and hypothesis testing

Morphometric data usually have a hierarchical structure (i.e., cells are nested within patients), which should be taken into consideration in the analysis. In the recent years, special methods of handling hierarchical data, called multilevel models (MM), as well as corresponding software have received considerable development. However, there has been no application of these methods to morphometric data yet. In this paper we report our first experience of analyzing karyometric data by means of MLwiN – a dedicated program for multilevel modeling. Our data were obtained from 34 follicular adenomas and 44 follicular carcinomas of the thyroid. We show examples of fitting and interpreting MM of different complexity, and draw a number of interesting conclusions about the differences in nuclear morphology between follicular thyroid adenomas and carcinomas. We also demonstrate substantial advantages of multilevel models over conventional, single‐level statistics, which have been adopted previously to analyze karyometric data. In addition, some theoretical issues related to MM as well as major statistical software for MM are briefly reviewed.

Application of multilevel models to morphometric data. Part 2. Correlations

Multilevel organization of morphometric data (cells are "nested" within patients) requires special methods for studying correlations between karyometric features. The most distinct feature of these methods is that separate correlation (covariance) matrices are produced for every level in the hierarchy. In karyometric research, the cell-level (i.e., within-tumor) correlations seem to be of major interest. Beside their biological importance, these correlation coefficients (CC) are compulsory when dimensionality reduction is required. Using MLwiN, a dedicated program for multilevel modeling, we show how to use multivariate multilevel models (MMM) to obtain and interpret CC in each of the levels. A comparison with two usual, "single-level" statistics shows that MMM represent the only way to obtain correct cell-level correlation coefficients. The summary statistics method (take average values across each patient) produces patient-level CC only, and the "pooling" method (merge all cells together and ignore patients as units of analysis) yields incorrect CC at all. We conclude that multilevel modeling is an indispensable tool for studying correlations between morphometric variables.

Dynamics of homologous chromosome pairing during meiotic prophase in fission yeast

Pairing of homologous chromosomes is important for homologous recombination and correct chromosome segregation during meiosis. It has been proposed that telomere clustering, nuclear oscillation, and recombination during meiotic prophase facilitate homologous chromosome pairing in fission yeast. Here we examined the contributions of these chromosomal events to homologous chromosome pairing, by directly observing the dynamics of chromosomal loci in living cells of fission yeast. Homologous loci exhibited a dynamic process of association and dissociation during the time course of meiotic prophase. Lack of nuclear oscillation reduced association frequency for both centromeric and arm regions of the chromosome. Lack of telomere clustering or recombination reduced association frequency at arm regions, but not significantly at centromeric regions. Our results indicate that homologous chromosomes are spatially aligned by oscillation of telomere-bundled chromosomes and physically linked by recombination at chromosome arm regions; this recombination is not required for association of homologous centromeres.

Comparative karyometric study of the glandular epithelium of normal nasal mucosa and rhinosinus polyposis

BACKGROUND

Rhinosinus polyposis, characterized by a degeneration of the nasal mucosa of the middle meatus, is poorly understood but probably is correlated with several clinical and etiopathogenic entities. Although not definitely characterized, infectious, atopic, inflammatory, genetic, and other factors are involved. The occurrence of malignant degeneration also has been suggested.

METHODS

To contribute to the elucidation of the etiopathogenicity of rhinosinus polyps, we performed a karyometric analysis of their glandular mucosa compared with the normal mucosa.

RESULTS

A significant increase in nuclear volume was observed, which was not accompanied by changes in shape.

CONCLUSION

The results suggest that nuclear alterations may contribute to the pathogenicity of this condition.

Digital karyometry in pancreatic adenocarcinoma

OBJECTIVE

To characterize nuclei from pancreatic adenocarcinoma and nonneoplastic pancreatic tissue by digital karyometry, demonstrating specific nuclear signatures for each of them.

STUDY DESIGN

Of cells from malignant and nonmalignant pancreatic tissue, 1,300 nuclei were assessed by digital karyometry from paraffin blocks stored at the Pathology Service of Hospital de Clinicas de Porto Alegre. A set of 40 features descriptive of the spatial and statistical distribution of nuclear chromatin was computed for each nucleus. Signatures were created for both types of tissue, and a distance metric from "normal" was defined and calculated for them.

RESULTS

There were significant differences in 11 features between the 2 groups, allowing the creation of digital signatures.

CONCLUSION

Nuclear chromatin texture signature can offer a specific digital characterization for both pancreatic adenocarcinoma and nonmalignant pancreatic tissue. Several isolated nuclear features serve as markers for the diagnosis of pancreatic adenocarcinoma. The present karyometric study of normal and malignant pancreatic tissue may be of use as a continuing tool to early diagnosis of pancreatic adenocarcinoma as it can be applied to cytologic specimens, also. In the future, studies using this technique should assess the chemopreventive potential of different agents as well as prognosis and treatment options for pancreatic adenocarcinoma.

[Nuclear shape assessment of the cells in precancerous lesions and laryngeal cancer]

The authors assessed morphometrically the nuclei shape of the normal mucosa, precancerous lesions (dysplasia, keratosis) and laryngeal cancer in the postoperative samples of 12 patients treated in the Laryngology Department Silesian Medical Academy in Zabrze. Five slides from the same patient, each 4 um thick were assessed. The histologic samples were measured by system Quantimet 500 + Color Option with magnification 2100x. Roundness, aspect ratio and fullness ratio were evaluated. The relationship among the morphologic lesions using shape descriptors was assessed. In some cases there were no significant differences between the nuclei of mild dysplasia cells and the cells of the normal epithelium. The results indicate significant karyometric shape differences of the normal mucosa, precancerous lesions and cancer of the larynx.

Karyometric features differentiate early invasive cervical squamous cell carcinoma from preinvasive carcinoma

The aim of the study was to investigate whether karyometric features reflect phenotypic change from preinvasive to early invasive squamous cell carcinoma of the cervix uteri. The material for the study was obtained from 12 patients diagnosed in the Chair of Pathomorphology. Each specimen contained both preinvasive and microinvasive lesions. The system of image acquisition and analysis consisted of a microscope coupled with a CCD camera and a PC computer. The software based on AnalySIS 3.0 system (Soft Imaging Systems GmbH) automatically detected cell nuclei and measured the preselected parameters. In each case 250 cell nuceli from both preinvasive and invasive components were analyzed. Significant differences in basic karyometric parameters were found both within individual cases and especially between groups studied. The present findings confirm the presence of early cytological changes at the onset of invasion. From the practical viewpoint the results suggest that karyometric features measured by image analysis might be used as a diagnostic tool, especially in cases where the diagnosis of microinvasion is difficult.

A phylogenetic analysis of cordyliformes (Reptilia: Squamata): comparison of molecular and karyological data

A karyological study and the analysis of two mitochondrial genes were conducted in several species of cordyliformes from Madagascar. Both studies confirmed the monophyly of cordyliformes. The karyological conservatism and small genetic distance among mitochondrial genes observed in these species are in line with the hypothesis that all cordyliformes should be included in a single family. The two studies yielded contrasting results with regard to the relationships between the Malagasy species and the Cordylidae and Gerrhosauridae. Nonetheless, the consistency between the data from mitochondrial gene analysis and those of taxonomic studies based on morphological characters is more in favor of an affinity between Malagasy Zonosaurinae and Gerrhosauridae and suggests that the karyological similarities between the former and the Cordylidae may be due to plesiomorphy. Interesting, though not conclusive, data were also obtained on interspecific relationships among Zono-

[The analysis of the relationship between integrated grade of the gray and other karyometric parameters in the precancerous lesions and laryngeal cancer]

The authors assessed morphometrically the parameters describing nuclei of the normal epithelium (superficial and basal layers), precancerous lesions (dysplasia and keratosis) and laryngeal cancer in the postoperative samples of 12 patients treated in the II Laryngology Clinic Silesian Medical Academy in Zabrze. Then the relationship between the integrated grade of grey (the index of changes in DNA structure) and the others kariometric parameters was evaluated. The value of the integrated grade of grey was the smallest in the superficial layers nuclei and the biggest in the laryngeal cancer one. The evaluation of the relationship was made by using the Spearman Rang Test. The integrated grade of grey was correlated with others quantitative nuclear measurements, though the correlation power was differ in the individual morphometrical stages.

[The analysis of cellular nuclei of the normal epithelium, precancerous lesions and cancer of the larynx]

The aim of the study was to relationship analysis between the karyometrical parameters of the laryngeal mucosa and the morphometrical states as well as the morphometrical comparison among the normal epithelium, precancerous lesions and cancer of the larynx. The following nuclear parameters were assessed: area, equivalent diameter, length, width, perimeter, convex area and perimeter, roundness, elongation and fulfillment. The relationship between karyometrical parameters and morphometrical lesions were found to be statistically significant. In some cases of the measurements there was no significant difference between the mild dysplasia cells and the superficial layers of the normal epithelium.

[Morphometric analysis of cell nuclei and regional lymph node status with patients suffering from laryngeal carcinoma]

We analysed 61 patients suffering from squamous cell carcinoma of larynx, who were treated in the Department of Otolaryngology, Collegium Medicum, Jagiellonian University, Cracow. Seven parameters of the cell nuclei and their variance were studied with the aid of a computer-assisted system of image analysis. The slides were viewed with a high-resolution black and white camera (Mintron) connected to the computer with the frame graber card (512 x 512 pixels with 256 gray levels, Vist software) at x630 magnification with an Axiophot microscope. It was established that high values of nuclear area, perimeter, density, long or shot nuclear axis carry an increased risk of metastases to regional lymph nodes.

Nuclear cytometric changes in breast carcinogenesis

Breast cancer is thought to originate through progressively aberrant precursor lesions, paralleled by increasing morphological changes. The aim of this study was to quantify nuclear features by image cytometry in invasive breast cancer and its early (hyperplasia) and late (ductal carcinoma in situ) precursor lesions, in order to objectively describe nuclear changes in the spectrum of proliferative intraductal and invasive breast lesions. Image cytometry was performed on tissue sections of 20 samples of normal breast tissue, 71 of usual ductal hyperplasia (UDH), nine of atypical ductal hyperplasia (ADH), and 11 of well-differentiated and 13 of poorly differentiated ductal carcinoma in situ (DCIS) lesions. The invasive breast carcinomas consisted of 19 well-differentiated and 24 poorly differentiated lesions. Through the spectrum from normal breast tissue to invasive carcinoma, progressive changes in many nuclear features were measured. Significant differences were found between nuclei of florid ductal hyperplasia compared with mild and moderate ductal hyperplastic lesions, suggesting that florid ductal hyperplasia may be a more advanced lesion than assumed and may contain cancer precursor cells. No differences were found between ADH and well-differentiated DCIS, suggesting that these lesions are closely related. Feature values of well-differentiated DCIS were comparable to values found in well-differentiated invasive carcinoma and the same applied to poorly differentiated DCIS and invasive lesions. These results support the hypothesis that breast cancer develops through different routes of progression, one leading to well-differentiated invasive cancer through well-differentiated DCIS, and one leading to poorly differentiated invasive cancer through poorly differentiated DCIS. In conclusion, image cytometry reveals progressive changes in nuclear morphological and subvisual chromatin distribution features in the spectrum from intraductal proliferations to invasive breast cancer. This provides evidence for a progression from usual to atypical ductal hyperplasia and then to invasive cancer, through different routes for well-differentiated and poorly differentiated lesions.

Nuclear morphometry for the prediction of regional lymph nodes metastases in patients with cancer of the larynx

The changes in cell nuclei reflect their activity. Quantitative morphometric analyses of tumor nuclei could be instrumental in providing prognostic information. We studied whether, and if so, which specific nuclear parameters and histoclinical factors in patients with cancer of the larynx could be related to the lymph node metastases. Specimens were taken from 61 patients surgically treated in the Department of Otolaryngology, Jagiellonian University, Cracow, Poland, between 1987 and 1988. The period between the onset of the first symptoms and the actual commencement of the treatment spanned no more than 9 months. The follow-up period was no shorter than 5 years. Histologically confirmed metastases in the regional lymph nodes were found in 16 patients. The histologic grading and tumor front grading was pursued in all cases. Fourteen parameters of the nuclei were studied with the aid of a computer-assisted system of image analysis. The morphometric parameters and the histoclinical factors were analyzed by the chi(2) test and the stepwise logistic regression. It was established that nuclear area > or =66 microm (P = 0.042), perimeter > or =32 microm (P = 0.087), optical density > or =22,500 (P = 0.027), long axis > or =10.15 microm (P = 0.025), short axis > or =7.3 microm (P = 0.003), TFG assessed (> or =15 points) and tumor advancement (T3, T4) were related to more frequent metastases to the lymph nodes. The morphometric parameters of the greatest significance were short axis and optical density. The quantitative morphometric analysis could prove a useful tool in predicting metastases to the lymph nodes.

Nuclear profiles of cancer cells reveal the metastatic potential of gastric cancer

Nuclear profiles have been reported as useful prognostic predictors in various cancers. Data from computerized morphometry are objective and can be quickly derived using conventional microscopic analysis, but image analysis of nuclear features has only rarely been applied to investigations of gastric cancer. The aim of this study was to evaluate the correlation between one of these morphological nuclear features and the clinicopathological parameters in patients with gastric cancer. The morphometric nuclear feature (nuclear area) was analysed in 400 patients with gastric cancer. In each case, 300 cancer nuclei on routine haematoxylin and eosin-stained slides were analysed through the use of a computer-assisted image analysis system which traced the nuclear profiles (magnificationx400) on a computer monitor. The morphometric data were compared with the patients' clinicopathological status and survival rate. The mean nuclear area (NA) of cancer cells from 400 cases of gastric cancer was 47.2 microm(2). The NAs of cancer cells from tumours with microvessel invasion (lymphatic or venous invasion), lymph node metastasis or hepatic metastasis at the time of operation were significantly larger than those of cancer cells from tumours without such invasion or metastases. Cytokeratin (CK) immunostaining was performed on 2577 lymph nodes from 91 patients with advanced gastric cancer (pT3, pN0, pM0, stage II) to detect micrometastases. CK-positive lymph nodes were detected in 350 of 2577 lymph nodes (13. 6%) and in 62 of 91 patients (68.1%). The mean NA of cancer cells from 62 tumours with micrometastases (44 microm(2)) was larger than that of cancer cells from 29 tumours without micrometastases (38.8 microm(2), p=0.043), and a significant positive correlation was detected between the NAs of cancer cells from 91 tumours and the number of micrometastatic lymph nodes of 91 patients (rho=0.278, p=0. 008). Cancer cells with large NA correlated strongly with haematogenous and lymph node recurrence or relapse after gastrectomy and the NA of cancer cells was identified as an independent prognostic factor in gastric cancer. Nuclear morphometry is an objective, reproducible, and technically uncomplicated procedure. The NA of cancer cells correlates closely with the metastatic potential of gastric cancer. Nuclear morphometry may therefore be useful for the selection of patients who are at risk of haematogenous or lymph node metastatic recurrence after surgery.

Multivariate karyometric approach in differential diagnosis of follicular thyroid neoplasms. A study of 31 cases

A retrospective analysis of 19 follicular adenomas, 12 minimally invasive follicular carcinomas and 3 widely invasive follicular carcinomas of the thyroid was performed on 5-microm-thick Feulgen-stained paraffin sections by means of a semiautomatic system for picture analysis. The major aim was to assess the potential of multiparameter karyometry for separation of the first two tumour types. Sixteen planimetric and densitometric features were defined in each case on 200-300 randomly selected nuclei and processed by a number of uni- and multivariate statistical methods. Despite predominantly significant ANOVA results a substantial overlap between tumour groups limited the practical usefulness of any karyometric feature alone. Factor and cluster analyses indicated independence of planimetric and densitometric parameters from each other, which was of crucial importance in finding an optimal subset of variables for discriminant analysis. The classification rule derived from the latter procedure was checked by the "jack-knife" method, by classification of 3 widely invasive cancers and by hierarchical tumour clustering. Sensitivity and specificity of the model for detection of malignancy were 100% and 94.7%, respectively. A multivariate karyometric approach, when applied correctly, can be a useful tool for differentiation between follicular adenomas and minimally invasive follicular carcinomas of the thyroid.

Detection of hyperdiploid karyotypes (>50 chromosomes) in childhood acute lymphoblastic leukemia (ALL) using fluorescence in situ hybridization (FISH)

ALL patients with a hyperdiploid karyotype of more than 50 chromosomes (high hyperdiploidy) carry a better prognosis in contrast to patients presenting with other cytogenetic features, and an appropriate less intensive therapy protocol should be developed for these patients. For this reason it is desirable to have a quick screening method identifying those with this type of hyperdiploidy. We therefore studied the bone marrow and/or blood cells of 278 children with ALL using double target fluorescence in situ hybridization (FISH) on interphase. A combination of DNA probes (repetitive, centromere specific) was applied detecting chromosomes which are most frequently overrepresented in patients with hyperdiploidy (>50), at chromosomes 6, 10, 17 and 18. All patients showing hybridization signals differing from the normal signal distribution of two spots for each tested chromosome were analyzed cytogenetically as well. 102 children (102/278; 36.7%) were found to have a clone with aberrant FISH results. In 80 patients (80/278, 28.8%) the cytogenetic analysis detected a hyperdiploid karyotype >50 chromosomes, whereas the remaining patients (n=12) could be related to other ploidy subgroups, ie hyperdiploidy with 47-50 chromosomes, haploidy, triploidy/tetraploidy. Comparison of the FISH results with the measurements of the DNA content showed good agreement for 88.8% (208/234) of the investigated patients. The detected rate of 28.8% patients with a high hyperdiploid karyotype in our investigated cohort is comparable to the frequency of other studies. Only one patient was not identified as having a hyperdiploid karyotype with our combination of DNA probes. Our results indicate that FISH is a feasible and quick screening method for the detection of hyperdiploid karyotypes (>50 chromosomes) and other ploidy subgroups.

Reverse transcription polymerase chain reaction is a reliable assay for detecting leukemic colonies generated by chronic myelogenous leukemia cells

Single-colony karyotyping (SCK) and reverse-transcription polymerase chain reaction (RT-PCR) are two increasingly used techniques for the quantification of leukemic colonies generated by chronic myelogenous leukemia (CML) cell fractions purged or selected in vitro. Recently, the existence of Philadelphia (Ph) chromosome positive progenitors with a silent BCR-ABL gene has been reported, thus raising concerns on the use of RT-PCR for detecting BCR-ABL positive progenitors. In order to investigate this issue further, colonies (n = 204) generated by mononuclear (MNC) or CD34+ CML cells were individually harvested, divided into two aliquots and analyzed both at the cytogenetic level to detect the Ph chromosome, and the molecular level to detect BCR-ABL transcripts. The mean (+/- s.d.) percentages of colonies analyzable by either SCK or RT-PCR were 74 +/- 16% and 86 +/- 16%, respectively. A significant percentage of colonies (67 +/- 19%) could be successfully analyzed by both SCK and RT-PCR. Although the majority of these colonies (97 +/- 5%) were Ph-positive and BCR-ABL-positive, a negligible percentage (4%) of progenitors were Ph-positive but BCR-ABL-negative. In order to test the influence of colony size on the outcome of molecular analysis, the efficiency of our RT-PCR assay in detecting BCR-ABL transcripts was investigated by means of experiments in which the number of cells used to start RNA extraction was serially reduced. These experiments showed that at least 150 cells were necessary to achieve a reproducible amplification of BCR-ABL transcripts. By correlating the size of harvested colonies with the outcome of molecular analysis, it was evident that BCR-ABL-negative but Ph-positive colonies represented false negative results occurring when a number of leukemic cells below the detection limit of our RT-PCR assay was analyzed. In conclusion, our data demonstrate that individual CML colonies grown in semisolid culture assays can be indifferently analyzed by SCK or RT-PCR, and support an extensive use of a carefully standardized RT-PCR assay to estimate the leukemic burden within samples which have been purged and selected in vitro.

The reproducibility of nuclear morphometric measurements in invasive breast carcinoma

The intraobserver and interobserver reproducibility of computerized nuclear morphometry was determined in repeated measurements of 212 samples of invasive breast cancer. The influence of biological variation and the selection of the measurement area was also tested. Morphometrically determined mean nuclear profile area (Pearson's r 0.89, grading efficiency (GE) 0.95) and standard deviation (SD) of nuclear profile area (Pearson's r 0.84, GE 0.89) showed high reproducibility. In this respect, nuclear morphometry equals with other established methods of quantitative pathology and exceeds the results of subjective grading of nuclear atypia in invasive breast cancer. A training period of eight days was sufficient to produce clear improvement in consistency of nuclear morphometry results. By estimating the sources of variation it could be shown that the variation associated with the measurement procedure itself is small. Instead, sample associated variation is responsible for the majority of variation in the measurements (82.9% in mean nuclear profile area and 65.9% in SD of nuclear profile area). This study points out that when standardized methods are applied computerized morphometry is a reproducible and reliable method of assessing nuclear atypia in invasive breast cancer. For further improvement special emphasize should be put on sampling rules of selecting the microscope fields and measurement areas.

Nuclear morphometry in node-negative breast carcinoma

OBJECTIVE

To determine whether nuclear morphometry can confirm or add useful information to classic clinicopathological prognosticators to identify the subpopulation of breast carcinoma patients with node-negative (N-) disease, at high risk of disease relapse.

STUDY DESIGN

On the basis of results obtained by clinicopathologic evaluation of a group of patients with N- breast cancer, on a test group of 56 cases (32 patients disease free and 24 with relapse), we performed a morphometric analytical study of nuclei using the Shape Analytical Morphometry (SAM) software system; 20 nuclei for each case and 17 morphometric parameters for each nucleus were analyzed.

RESULTS

The SAM system allowed us to quantify shape differences in nuclei in terms of contour irregularities and asymmetries along with evaluation of nuclear dimensions. Dimensional and analytic parameters were subjected to univariate (Student's t test) and multivariate (Hotelling's test) analysis. Multivariate discriminant analysis showed that an exact forecast of disease relapse could be made in 77% of patients with N- breast cancer by using a set of six both analytic and dimensional parameters.

CONCLUSION

These results confirm that nuclear pleomorphism is the result of both contour irregularities and shape asymmetries and that even though they should be considered preliminary results, they stress the importance of quantitative shape evaluation.

Grading of precancerous laryngeal lesions by multiparameter image analysis at separate epithelial layers

In order to detect early precancerous changes which do not involve the whole thickness of the epithelium, we used a novel image analysing program based on an IBAS system (Kontron, Germany) to determine nuclear DNA content (NC) as well as average nuclear area (NA) and variation of nuclear area (VA), in the entire epithelium and in three sublayers, parabasal, intermediate, and superficial. DNA aneuploidy was found in only half of the cases classified as 'high-grade' (HG) lesions, comprising carcinoma in situ (CIS) and severe epithelial dysplasias (EDIII), and was chiefly demonstrable in the parabasal third of the epithelium. The other lesions were DNA euploid. HG lesions showed highly significant increases of NA and VA at the lower levels of the epithelium when compared with 'low-grade' (LG) lesions comprising moderate and mild epithelial dysplasias (EDII and EDI). Our data show that the combination of multiparameter image analysis with conventional morphology assists in the objective grading of precancerous lesions and permits the reliable detection of high-grade lesions.

Estimates of nuclear volume in plaque and tumor-stage mycosis fungoides. A new prognostic indicator

It is well documented that mycosis fungoides (MF), a cutaneous T-cell lymphoma, has a variable clinical course. Unbiased stereological estimates of three-dimensional volume-weighted mean nuclear size (nucl vV) of mycosis cells were obtained in a retrospective study of 18 patients with a total of 34 biopsies of cutaneous plaque and tumor-stage MF. The value of nucl vV in the first sampled biopsy, as well as the average and highest values, were determined in biopsies from each patient. The patients were divided into two groups, either above or below the group median. There was a strong positive correlation between shorter survival and an average value of nucl vV > 104 microns 3 or a highest value of nucl vV > 126 microns 3 (2p = 0.002 and 0.003, respectively). A nucl vV > 91.6 microns 3 in the first biopsy was also suggestive of a shorter survival (2p = 0.07). There was no clear pattern of nucl vV evolution in the patients with multiple biopsies, but the impact of various therapeutic regimens cannot be assessed. Certain estimates of nucl vV appear to be good prognostic indicators in plaque and tumor-stage MF, but further study of a larger series of patients is needed to corroborate these results and assess the impact of differing therapeutic regimes.

Myocyte nuclear and possible cellular hyperplasia contribute to ventricular remodeling in the hypertrophic senescent heart in humans

OBJECTIVES

The present investigation was designed to evaluate the growth reserve capacity of the aged and senescent myocardium.

BACKGROUND

Aging affects the ability of the heart to sustain alterations in ventricular loading, and this phenomenon may be coupled with attenuation of the hypertrophic reaction of the myocardium. However, because myocyte cellular hyperplasia has been documented experimentally in the old heart, a similar adaptation may also occur in humans and play a role in this process.

METHODS

The changes in number and size of ventricular myocytes were measured quantitatively in pathologic hearts of elderly subjects. Morphometric methodologies were applied to the analysis of 13 hypertrophic hearts obtained at autopsy from patients 80 +/- 4 (mean +/- SD) years old. An identical number of nonhypertrophic hearts collected from subjects 76 +/- 7 years old were used as control hearts.

RESULTS

A 71% increase in left ventricular weight was associated with a 33% increase in average myocyte cell volume per nucleus and a 36% augmentation in the total number of myocyte nuclei in the ventricular myocardium. However, a 55% increase in right ventricular weight was the result of a 59% increase in the aggregate number of myocyte nuclei, with no change in myocyte cell volume. These cellular processes were associated with a 95% and 83% enlargement of the myocardial interstitium in the left and right ventricle, respectively.

CONCLUSIONS

Myocyte nuclear and possibly cellular hyperplasia appear to be the prevailing growth mechanism of the overloaded aging myocardium. Proliferation of myocyte nuclei and connective tissue accumulation are the major determinants of ventricular remodeling in the hypertrophic senescent heart.

Measurement and characterization of micronuclei in exfoliated human cells by fluorescence in situ hybridization with a centromeric probe

The micronucleus (MN) assay in human exfoliated cells has been widely used to detect the genotoxic effects of environmental mutagens, infectious agents and hereditary diseases. Substantial variability characterizes the MN frequencies reported by different research groups. One reason for this may be the restricted resolution power of the Feulgen-Fast-Green staining that is routinely used. Here we describe a new version of the MN assay that employs fluorescent propidium iodide staining along with fluorescence in situ hybridization (FISH) with a centromeric probe. Buccal and urothelial cells were collected from 5 healthy unexposed female volunteers and 55,000 cells analyzed for MN frequency and abnormal nuclear events. The Feulgen-Fast-Green and the new fluorescent staining produced very similar results. The frequency of MN in buccal cells was 0.145 +/- 0.118% and in urothelial cells 0.083 +/- 0.074%. No correlation was found between the frequencies of MN in the two types of exfoliated cells. FISH with a centromeric probe allowed MN containing whole chromosomes with a centromere to be differentiated from those containing only acentric fragments. The former appear as a result of chromosome lagging in mitosis, while those without a centromere are due to chromosome breakage. In urothelial cells 43% of MN were centromere-negative and in buccal cells -44%. Fluorescent staining provided more accurate scoring of degenerative cells than standard Feulgen-Fast-Green staining. The combined frequency of pycnotic cells, "broken eggs" and cells with fragmented nuclei did not exceed 2%, while that of karyorrhexis and karyolysis together was as high as 21%. Significant interindividual variability was found in the frequency of cells with karyolysis and karyorrhexis. Thus, the new version of micronucleus assay allows for MN to be scored more precisely, the mechanism of MN formation to be determined and abnormal nuclear events to be readily identified in exfoliated human cells. It is therefore ideal for studying genotoxicity in human populations using exfoliated cells from the mouth, bladder and nose.

[The circadian evolution of the karyometric indices of the inner hair cells. A statistical analysis]

We have realized a statistic study about "Karyometric Index" in the hair cells of the Corti organ of the albino Wistar rat [correction of guinea pig] in thirty of these animals; after in vivo fixation. The Karyometric Index variations are a good indicator of the cellular basic functional activity. Therefore we tried to clarify if the their cells are or not resembling to other cellular types with the functional circadian circles as well as if they present it or not in their basic functionalism, as they are also included in the "Endocrine Difusse System" and the "Paraneuron" concepts.

[Estimation of nuclear volume of nontumorous bladder mucosa in patients with bladder tumor--measurement by vertical section]

The mean nuclear volume (MNV) of non-tumorous bladder mucosa in 27 patients with a bladder tumor was estimated by using a new stereological method, "vertical section". Eighty four specimens were obtained by punch biopsy from preselected sites of urinary bladder. Thirteen specimens (10 patients) out of 84 were histologically diagnosed as carcinoma in situ (CIS). Bladder mucosa of 24 patients with various benign diseases were also measured as normal controls. The MNV of the normal control group was 127.1 +/- 19.6 microns 3 (mean +/- standard error) and that of the specimens diagnosed with CIS was 279.6 +/- 69.0 microns 3. There was no overlap between the two groups. Out of 71 specimens diagnosed as having no malignancy, 30 (42.3%) exhibited significantly increased MNV. Estimation of the MNV of non-tumorous bladder mucosa may be useful for standardization of CIS. Further studies are needed to investigate the role of the increased MNV in histologically normal mucosa in the course of a bladder tumor.

[Results of the cytogenetic prenatal diagnosis in the first and second trimesters of pregnancy]

The authors analyze the results of prenatal diagnosis carried out in women during the first and second pregnancy trimesters. Cytogenetic screening was carried out in risk-group pregnant women, i.e. in women aged over 36, in cases with family history of chromosome mutation or a previous child with chromosome aberration, or a sex-linked disease in one of family members, etc. Chromosome preparations from amniotic fluid cell cultures and 'direct' chromosome preparations from chorionic villi were analyzed. The authors discuss the efficacy of prenatal diagnosis in various pregnancy periods, fetal tissue collection methods and quantities necessary for the examination.

Nuclear shape analysis for assessment of prognosis in renal cell carcinoma

Clinically localized renal cell carcinoma is cured by radical nephrectomy in 47% [stage T3a (II)] to 65% [stage T1, T2 (I)] of the patients. Local recurrence and metastatic disease probably result from undetectable microscopic metastases present at operation. Chemotherapy and immunotherapy may improve cure rates if administered adjuvantly. The outcome of individual patients who share surgical stage cannot be predicted reliably by tumor histology, pathological and/or nuclear deoxyribonucleic acid analysis. Two groups of 10 patients with clinically localized renal cell carcinoma were similar by sex distribution (5 men and 5 women), surgical stage (stages T1 in 1, T2 in 6 and T3a in 3 patients) and age (54.3 +/- 15.2 standard deviation versus 55.8 +/- 8.7 years). Group 1 had no recurrences with a minimum followup of 5 years and a mean followup of 10 years. Group 2 died of metastatic renal cell carcinoma after a mean of 5 years. All neoplastic areas of each paraffin-embedded operative specimen were randomly sampled and the nuclear perimeter of 150 cancerous cells was digitized. There were 25 shape descriptors calculated for each nucleus. All shape descriptors for each patient were described by 19 statistical tests. Nuclear perimeter and area as well as mean nuclear roundness factor failed to separate the 2 groups. Range median quartiles of ellipticities by Fourier analysis, coefficients of variation of chain code minimums and relative means of largest 10 convexity values produced greatest separation (Mann-Whitney-Wilcoxon test p less than 0.001, and variance normalized difference 3.21, 3.29 and 2.83, respectively). These descriptors normalized and summed provided near perfect separation (Mann-Whitney-Wilcoxon test p less than 0.001 and variance normalized difference 3.59). We developed a quantitative nuclear morphometric analysis system that permitted the correct assignment of outcome in 19 of 20 patients. Accurate prediction of prognosis in patients with clinically localized renal cell carcinoma by nuclear shape analysis may allow for selection of patients for adjuvant therapy who have clinically undetectable metastatic disease.

Computerized interactive morphometry. An expert system for the diagnosis of lymphoid-rich effusions

The authors present experimental techniques for the diagnosis of malignant lymphoma and benign lymphocytosis in lymphoid-rich effusions with the use of an inexpensive microcomputer-based video system for computerized interactive morphometry (CIM). Lymphoid cells were randomly selected by a trained observer from real-time images of Papanicolaou-fixed and -stained cytospin smears prepared from pleural, peritoneal, or pericardial effusions. The lymphoid cells were classified by the instrument, based on the size and shape of their nuclear profiles. The morphometric data collected by the instrument were interpreted by a simple rule-based expert system that classified the smears as benign or malignant. One hundred four cases, including 28 malignant lymphomas, 63 benign lymphocytoses, 8 chronic lymphocytic leukemias, and 5 cases with incomplete immunopathologic data, were studied retrospectively. Sixty-three of these effusions had been stained to detect light chain monoclonality. Ninety-one effusions were correctly classified by the expert system. There were four potential false negative diagnoses and one potential false positive diagnosis by the CIM system. Eight effusions from patients with chronic lymphocytic leukemia (CLL) were consistently classified as benign. Although the author's series of patients with a history of CLL is small, their results suggest that CIM is unsuitable for the diagnosis of malignancy in these effusions. If only those effusions from patients with a history of CLL are excluded, the predictive value of a diagnosis of malignant lymphoma was 96.5%, whereas the predictive value of a diagnosis of benign lymphocytosis was 94.0%.

Morphometric analysis of the homogeneity of lymphoid cell populations in fine-needle aspiration cytology smears

Quantitative morphometry was used to evaluate the homogeneity of lymphoid cell populations in fine-needle aspiration cytology smears of lymph nodes from eight non-Hodgkin's lymphomas and four benign lymphoid proliferations. Using the standard deviation of log-transformed nuclear areas as the measure of lymphoid cell homogeneity, diffuse small cell lymphomas were found to be significantly more homogeneous than diffuse large cell lymphomas or benign lymphoid proliferations, but there was no significant difference in the homogeneity of the latter two groups. Two of four large cell lymphomas showed a bimodal distribution of nuclear areas. Methodologic issues--including the random selection of cells, the number of cells that should be counted in each case, the significance of microscopic field-to-field variation in this setting, and the significance of drift in observations during the examination of individual cases--are discussed.