Hai-Shan Wu

Ovarian dysplasia in prophylactic oophorectomy specimens

Ovarian dysplasia, a potential precursor to ovarian carcinoma, has been described in ovarian tissue obtained by prophylactic oophorectomy and also adjacent to ovarian carcinoma. Women with a family history of ovarian carcinoma, especially those of Jewish Ashkenazi descent, often test positive for BRCA mutant genes. Prophylactically removed ovaries, generally described as normal on macroscopic examination, can exhibit a “preneoplastic phenotype” and unsuspected neoplasm.

A parametric fitting algorithm for segmentation of cell images

This paper presents a parametric fitting algorithm for segmentation of cervical and breast cell images from cytology smears. A parametric elliptical model for cells is introduced and the parameters adjusted to fit the cell shapes while minimizing a cost function. Segmentation results of noisy human cervical cell and textured breast cell images demonstrate that the proposed parametric fitting algorithm is very successful in segmentation of images of both nonoverlapped and overlapped elliptically shaped cells.

Fractal characterization of chromatin appearance for diagnosis in breast cytology

This study explores the use of fractal analysis in the numerical description of chromatin appearance in breast cytology. Images of nuclei from fine‐needle aspiration biopsies of the breast are characterized in terms of their Minkowski and spectral fractal dimensions, for 19 patients with benign epithelial cell lesions and 22 with invasive ductal carcinomas. Chromatin appearance in breast epithelial cell nuclear images is demonstrated to be fractal, suggesting that the three‐dimensional chromatin structure in these cells also has fractal properties. A statistically significant difference between the mean spectral dimensions of the benign and malignant cases is demonstrated. The two fractal dimensions are very weakly correlated. A statistically significant difference between the benign and malignant cases in lacunarity, a fractal property characterizing the size of holes or gaps in a texture, is found over a wide range of scales. These differences are particularly pronounced at the smallest and largest scales, corresponding respectively to fine‐scale texture, indicating whether chromatin is clumped or fine, and to large‐scale structures like nucleoli. Logistic regression and artificial neural network classification models are developed to classify unknown cases on the basis of fractal measures of chromatin texture. Using leave‐one‐out cross‐validation, the best logistic regression classifier correctly diagnoses 95·1 per cent of the cases. The best neural network model can correctly classify all of the cases, but it is unclear whether this is due to overtraining. Fractal dimensions and lacunarity are useful tools for the quantitative characterization of chromatin appearance, and can potentially be incorporated into image analysis devices to assure the quality and reproducibility of diagnosis by breast fine‐needle aspiration biopsy.

Iterative thresholding for segmentation of cells from noisy images

We introduce an iterative thresholding algorithm for the segmentation of cells from noisy cell images. The thresholding image, which is initially a constant, changes iteratively with both the previous segmentation and image local activity. Experimental results for both synthesized and real cell images are provided to demonstrate the performance of the algorithm.

Segmentation of intestinal gland images with iterative region growing

A region growing algorithm for segmentation of human intestinal gland images is presented. The initial seeding regions are identified based on the large vacant regions (lumen) inside the intestinal glands by fitting with a very large moving window. The seeding regions are then expanded by repetitive application of a morphological dilate operation with a much smaller round window structure set. False gland regions (nongland regions initially misclassified as gland regions) are removed based on either their excessive ages of active growth or inadequate thickness of dams formed by the strings of goblet cell nuclei sitting immediately outside the grown regions. The goblet cell nuclei are then identified and retained in the image. The gland contours are detected by applying a large moving round window fitting to the enormous empty exterior of the goblet cell nucleus chains in the image. The assumptions based on real intestinal gland images include the closed chain structured goblet cell nuclei that sit side‐by‐side with only small gaps between the neighbouring nuclei and that the lumens enclosed by the goblet cell nucleus chains are most vacant with only occasional run‐away nuclei. The method performs well for most normal and abnormal intestinal gland images although it is less applicable to cancer cases. The experimental results show that the segmentations of the real microscopic intestinal gland images are satisfactorily accurate based on the visual evaluations.

Regression of Hepatic Fibrosis After Intestinal Transplantation in Total Parenteral Nutrition Liver Disease

BACKGROUND & AIMS Hepatic fibrosis may occur in patients with intestinal failure requiring total parenteral nutrition, leading to liver dysfunction necessitating combined intestinal and liver transplantation. The decision to perform combined transplantation as opposed to an isolated intestinal transplant is based on the presence of hyperbilirubinemia, portal hypertension, and advanced hepatic fibrosis. METHODS We identified 4 patients who underwent isolated intestinal transplantation having significant liver fibrosis. A novel image analysis technique was applied to serial liver biopsies to more precisely quantitate posttransplantation fibrosis regression separately within both portal and centrilobular areas. RESULTS All patients were found to have significant portal and centrilobular fibrosis regression, which occurred more rapidly in the former. Two patients had improvement in fibrosis despite infections and continuation of total parenteral nutrition, suggesting that hepatic fibrosis associated with intestinal failure may in part be related to adequate anatomic and functional bowel length. CONCLUSIONS Significant hepatic fibrosis and liver dysfunction may regress after intestinal transplantation and fibrosis regresses more rapidly in portal areas. This suggests that some patients with intestinal failure and associated liver disease may safely undergo isolated intestinal transplant without the need for concurrent liver transplantation and its attendant higher morbidity and mortality.

Prognostic Value of Quantitative p63 Immunostaining in Adenoid Cystic Carcinoma of Salivary Gland Assessed by Computerized Image Analysis

In a long‐term retrospective immunohistochemical study of adenoid cystic carcinoma (ACC) of salivary gland, we investigated the relation of p63 immunodetection to prognosis. Although it is generally agreed that the solid pattern is the most aggressive pattern of growth, ACCs with predominantly cribriform or tubular patterns have an unpredictable clinical course, with a relatively favorable 5‐year survival but a low 20‐year survival.

The NF-κB pathway mediates lysophosphatidic acid (LPA)-induced VEGF signaling and cell invasion in epithelial ovarian cancer (EOC)

OBJECTIVES Our previous report has implicated the involvement of VEGF-VEGFR-2 h signaling in LPA-induced EOC invasion. However, the mechanism by which LPA regulates VEGF and VEGFR-2 expression remains to be elucidated. In the present study, we systematically examined the signal transduction pathways activated by LPA and further evaluated whether LPAs effect on VEGF-VEGFR-2 signaling and EOC invasion was mediated by the activation of NF-κB pathway. METHODS Using a signal transduction PathwayFinder PCR array, we examined the expression change of 86 key genes representing 18 signal transduction pathways in DOV13 and SKOV3 cells upon LPA (20 μM) treatment. We also used quantitative PCR, Western blotting and ELISA to evaluate the effect of NF-κB pathway inhibition on VEGF(121), VEGF(165) and VEGFR-2 mRNA and protein expression/secretion with or without the presence of LPA (20 μM) in SKOV3. Cell invasion under various treatment conditions was assessed by Matrigel invasion assay and MMP-2 secretion was detected by gelatin zymography. RESULTS Our results showed that in both DOV13 and SKOV3, several of the NF-κB pathway components, such as TNF, are consistently activated by LPA stimulation. In addition, treatment with an NF-κB pathway activation inhibitor, at 10 μM, significantly decreased LPA-induced VEGF(121), VEGF(165) and VEGFR-2 mRNA expression and VEGF secretion, as well as LPA-induced SKOV3 invasion (p<0.05). When combined with an EGFR inhibitor, NF-κB pathway inhibition exhibited a significantly stronger effect than used alone (p<0.05) on reducing LPA-induced VEGF secretion and cell invasion. Additionally, NF-κB inhibition also decreased LPA-induced MMP-2 secretion and MMP-1 expression (p<0.05). CONCLUSIONS These results suggest that the NF-κB pathway plays an important role in LPA-induced VEGF signaling and EOC invasion and targeting this pathway may reveal potential therapeutic options for metastatic EOC.

Applications of Image Analysis to Anatomic Pathology: Realities and Promises

Image Analysis in Pathology is viewed as an ancillary method meant to provide objective support in the resolution of difficult problems. Its Achilles heel is the process of nuclear segmetation (delimitation of the nuclear membrane) which is extremely difficult in pathology materials. Although interactive segmentation procedures are available no reliable fully automatic method has been described. The only application of image analysis that has truly succeeded in Pathology is DNA ploidy measurement. A very desirable application is the quantitation of immunohistochemical markers, which is technically challenging, has been resolved only in certain cases and is unlikely to have a general solution. Nuclear quantitation has repeatedly proven to be helpful in reaching differential diagnoses, in particular when based on size distributions of nuclear profiles rather than its average, but is hampered by the segmentation problem discussed above. Texture analysis of chromatin is an exciting, mathematically complex application likely to succeed, for which many approaches have been described. Finally a diagnosis (classification) can be obtained based on algorithms applied to multiple descriptors of tumor cells (for instance nuclear sizes, chromatin texture, shape, etc). The best classificatory approaches are neural networks (a form of artificial intelligence), multivariate analysis, and logistic regression (statistical).

Reproducibility and accuracy of interactive segmentation procedures for image analysis in cytology

The segmentation of nuclear images is a crucial step in the development of procedures using image analysis for the cytological diagnosis of cancer. The purpose of this study is to evaluate the reproducibility and accuracy of several interactive segmentation methods which can be used in this context. Four methods were studied: a thresholding‐based method enabling selection of intensity histogram contrast and brightness, manual tracing with a stylus, and arc‐ and ellipse‐fitting routines. Features of nuclear size and shape were derived from nuclei segmented on repeated occasions by several individuals. Variance component models provided a statistical framework for evaluating the intraobserver and interobserver variability of these measurements in terms of their intraclass correlation coefficients. Of the methods tested, the arc‐fitting segmentation method gave the most reproducible results, and thresholding the least. Reproducibility was generally very high both between individuals and for repeated segmentations by a single individual. Accuracies of area measurements for the various methods, as determined with respect to point counting, paralleled the reproducibilities of the methods. Sample size requirements were observed to be more dependent on the biological variability of the tissue sampled than on the particular segmentation method or on the number of individuals performing segmentation.