Remote quantitation in the framework of telepathology.
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Journal Article↗
Biomedical subjects
M Oberholzer
Publications and source records attributed to M Oberholzer.
Altered expression of mdm-2 and its association with p53 protein status, tumor-cell-proliferation rate and prognosis in cervical neoplasia.
Recent results suggest that p53 inactivation is required for cervical-carcinoma development. The mdm-2 oncogene, which forms an auto-regulatory feedback loop with the normal p53 protein, has been found amplified in human carcinomas, thus abolishing the anti-proliferative function of p53. To investigate whether the mdm-2/p53 interaction plays a role in cervical neoplasms, we performed an immunohistochemical study in archival fixed, embedded specimens that included 178 pre-cancerous lesions (CIN) and invasive squamous-cell carcinomas of clinical stage IB. In addition to p53, we assessed the p53-associated protein, mdm-2, and the Ki-67 labelling index (LI). The presence of HPV was assessed by in situ DNA hybridization. Tumor expression of all nuclear proteins was scored as fraction of positive CIN or cancer nuclei. The analysis demonstrated a significant association of the Ki-67 LI with grade of atypia in cervical neoplasms. p53 accumulation and mdm-2 expression are higher in invasive carcinomas than in pre-cancerous lesions. No correlation was observed with HPV status. An inverse correlation was found between increased tumor-cell proliferation and mdm-2 expression in invasive carcinomas (p < 0.0001). mdm-2 expression was significantly associated with p53 accumulation (p < 0.02). However, the investigated nuclear proteins were not associated with overall survival in patients with invasive carcinomas. Cox stepwise-regression analysis revealed regional lymph node status and depth of invasion to be independent parameters.
Biomarkers, Tumor↗
Investigation of the Bcl-2 and C-myc expression in relationship to the Ki-67 labelling index in cervical intraepithelial neoplasia.
This is the investigation of the relationship between the neoplastic cell proliferation and the expression of bcl-2 and c-myc in human papillomavirus (HPV)-negative and HPV-positive cervical intraepithelial neoplasms (CIN). The expression of bcl-2 and c-myc was studied using quantitative immunohistochemistry in 20 specimens of normal cervical squamous epithelium and 73 specimens of CIN. To analyze the neoplastic cell proliferation rate, the Ki-67 labelling index was determined; the latter was significantly different between normal epithelium and various grades of CIN (p < 0.0001). The highest proliferation rate was found in high-grade CIN. In precancerous lesions, we found the number of bcl-2 positive cells lower than in normal epithelium, but with a significant difference between low-grade and high-grade CIN (p < 0.0001). The highest percentage of bcl-2 positive neoplastic cells was found in high-grade CIN. C-myc was rarely expressed in normal epithelium. Similar to the Ki-67 labelling index, c-myc immunostaining correlated with the histological grade of CIN, with the highest percentage of c-myc positive nuclei occurring in high-grade CIN (p < 0.0001). In contrast to bcl-2 immunoreactivity, the c-myc significantly was more expressed in high-risk HPV-positive than in HPV-negative lesions. The c-myc expression in CIN is closely related to the neoplastic cell proliferation rate. With progression of intraepithelial neoplasia, bcl-2 production in neoplastic cells increases with high co-expression of c-myc.
Female↗
[Frozen section diagnosis using telepathology].
DEFINITION: Since 1992 we transfer digitalized frozen section images by means of videomicroscope and a personal computer through the public telephone network (ISDN) to the Institut of Pathology at the University Hospital in Basel. The aim of this study is to determine whether the quality of frozen section diagnosis obtained by telepathology is comparable to the conventional one. METHOD: The frozen section diagnoses by telepathology from Oct. 1992 to May 1996 (n = 94) are compared to the paraffin sections performed in each case after the primary examination. The result is then compared to the well documented data of conventional frozen section diagnosis in the literature. RESULTS: From Oct. 1992 to May 1996 we performed 94 frozen sections. In 84 cases the diagnosis was correct compared to the paraffin section (89%). The sensitivity to detect a malignant tumor was 92%, the specifity 100%. Four examinations were not conclusive and one examination had to be canceled because of technical problems. DISCUSSION: In the literature, 92% of malignancy is diagnosed by conventional frozen section [1]. Telepathology gives the same result.
Frozen Sections↗
Methods in quantitative image analysis.
The main steps of image analysis are image capturing, image storage (compression), correcting imaging defects (e.g. non-uniform illumination, electronic-noise, glare effect), image enhancement, segmentation of objects in the image and image measurements. Digitisation is made by a camera. The most modern types include a frame-grabber, converting the analog-to-digital signal into digital (numerical) information. The numerical information consists of the grey values describing the brightness of every point within the image, named a pixel. The information is stored in bits. Eight bits are summarised in one byte. Therefore, grey values can have a value between 0 and 256 (2(8)). The human eye seems to be quite content with a display of 5-bit images (corresponding to 64 different grey values). In a digitised image, the pixel grey values can vary within regions that are uniform in the original scene: the image is noisy. The noise is mainly manifested in the background of the image. For an optimal discrimination between different objects or features in an image, uniformity of illumination in the whole image is required. These defects can be minimised by shading correction [subtraction of a background (white) image from the original image, pixel per pixel, or division of the original image by the background image]. The brightness of an image represented by its grey values can be analysed for every single pixel or for a group of pixels. The most frequently used pixel-based image descriptors are optical density, integrated optical density, the histogram of the grey values, mean grey value and entropy. The distribution of the grey values existing within an image is one of the most important characteristics of the image. However, the histogram gives no information about the texture of the image. The simplest way to improve the contrast of an image is to expand the brightness scale by spreading the histogram out to the full available range. Rules for transforming the grey value histogram of an existing image (input image) into a new grey value histogram (output image) are most quickly handled by a look-up table (LUT). The histogram of an image can be influenced by gain, offset and gamma of the camera. Gain defines the voltage range, offset defines the reference voltage and gamma the slope of the regression line between the light intensity and the voltage of the camera. A very important descriptor of neighbourhood relations in an image is the co-occurrence matrix. The distance between the pixels (original pixel and its neighbouring pixel) can influence the various parameters calculated from the co-occurrence matrix. The main goals of image enhancement are elimination of surface roughness in an image (smoothing), correction of defects (e.g. noise), extraction of edges, identification of points, strengthening texture elements and improving contrast. In enhancement, two types of operations can be distinguished: pixel-based (point operations) and neighbourhood-based (matrix operations). The most important pixel-based operations are linear stretching of grey values, application of pre-stored LUTs and histogram equalisation. The neighbourhood-based operations work with so-called filters. These are organising elements with an original or initial point in their centre. Filters can be used to accentuate or to suppress specific structures within the image. Filters can work either in the spatial or in the frequency domain. The method used for analysing alterations of grey value intensities in the frequency domain is the Hartley transform. Filter operations in the spatial domain can be based on averaging or ranking the grey values occurring in the organising element. The most important filters, which are usually applied, are the Gaussian filter and the Laplace filter (both averaging filters), and the median filter, the top hat filter and the range operator (all ranking filters). Segmentation of objects is traditionally based on threshold grey values. (AB
Algorithms↗
Telepathology: frozen section diagnosis at a distance.
Telepathology may be used to provide a frozen section service to hospitals without a department or institute of pathology. We have developed a telepathology system using the commercially available Integrated Services Digital Network (ISDN). The main software and hardware elements of our system are: Apple Macintosh workstations, a program for simultaneous transfer of image, voice and data, and a data bank for storage of patients' data and microscopic images. A picture instrument manager (PIM) makes remote control of microscopes or other instruments possible. The system connects the Department of Pathology of the University of Basel with the Regional Hospital of Samedan, 250 km away, and the Regional Hospital of Burgdorf, 100 km away. During a period of 20 months, frozen sections with the hospitals in Samedan and Burgdorf were performed in 53 patients. Between 54 and 58 s were required for the transfer of a diagnostic 8-bit grey level image containing 341 +/- 26.1 (standard error) kbytes (n = 13) or a diagnostic 24-bit colour image containing 165 +/- 16.9 kbytes (n = 40). Frozen section diagnosis was completed in 20-40 min. True-positive diagnoses of malignant tumours were achieved in 85.7% of cases (sensitivity = 0.857). No false-positive diagnosis was made. In 3 of the 53 cases telepathological diagnosis was not possible for technical reasons.
Frozen Sections↗
Karyomegalic interstitial nephritis: further support for a distinct entity and evidence for a genetic defect.
Karyomegalic interstitial nephritis was first described in 1979 by Mihatsch, who was reporting three such cases. We report here four additional cases as well as two family investigations. Our findings support the association of karyomegaly and interstitial nephritis as a distinct entity. Typical clinical features are asymptomatic progressive renal failure in the third decade of life and recurrent infections, mostly of the upper respiratory tract. Histologic alterations consist of markedly enlarged and hyperchromic nuclei in many tubular epithelial cells throughout the nephron accompanied by interstitial fibrosis in the surrounding atrophic tubules. Karyomegaly is not limited to the kidneys. In one case, autopsy revealed karyomegaly in epithelial and mesenchymal cells of many other organs. However, no association of karyomegaly with further histologic damage is evident except in the kidneys. Because of the familial clustering, karyomegalic interstitial nephritis seems to be an inherited disease. Examination of the nuclear proliferation-associated structures proliferating cell nuclear antigen/cyclin, Ki 67, and p53 suggests an inhibition of mitosis in karyomegalic cells. The finding of the same HLA haplotype, A9/B35, in four of six HLA-typed cases suggests the possibility of a genetic defect on chromosome 6, which is inherited and linked to the HLA locus.
Adult↗
Parathyroidectomy in primary hyperparathyroidism: preoperative localization and routine biopsy of unaltered glands are not necessary.
BACKGROUND: An assessment was made of operative risk and outcome after parathyroidectomy for primary hyperparathyroidism. METHODS: A retrospective study was conducted in a single center university hospital in Switzerland. The 173 patients (130 women and 43 men) ranged from 17 to 89 years of age (mean, 62.0 years). No routine preoperative localization methods were used for primary neck exploration. Parathyroidectomy was performed under general anesthesia. No routine use was made of intraoperative biopsy of glands whose macroscopic appearance was normal. The 173 patients underwent 179 operations (170 primary and 9 secondary interventions). Resection of a single gland was performed in 127 cases (73.4%) and of two glands in 36 cases (20.8%). Subtotal parathyroidectomy (3 1/2 glands) was performed in 10 cases (5.8%). RESULTS: Of 170 patients with primary intervention, 164 (96.5%) were normocalcemic after operation. Six of 170 patients (3.5%) underwent early reexploration. Three additional patients underwent late secondary procedures. These nine secondary operations were successful in seven patients (78%). At follow-up (mean, 24.7 months after operation) normocalcemia was noted in 163 of 171 patients (95.3%). Persistent and recurrent hyperparathyroidism occurred in 1.2% and 3.5% of patients, respectively. Permanent postoperative hypoparathyroidism was noted in 4% (six of seven patients underwent a subtotal parathyroidectomy for multiglandular hyperplasia). Operative morbidity and mortality were 2.3% and 0.6%, respectively. CONCLUSIONS: Our surgical strategy for treatment of primary hyperparathyroidism has proved to be safe with a favorable outcome in more than 95% of patients. This was possible without the routine use of preoperative localization studies and intraoperative biopsy of macroscopically normal glands. Routine biopsy of normal-appearing glands seems to be unnecessary and may increase the risk of hypoparathyroidism.
Adolescent↗
Diagnostic tools for differentiating between pleural mesothelioma and lung adenocarcinoma in paraffin embedded tissue. Part I: Immunohistochemical findings.
Specimens of 27 histologically definite mesotheliomas and 34 proven adenocarcinomas were examined with a panel of 14 antibodies: pan-epithelial antibody Lu-5, anti-keratin-18, anti-keratin-7, Ber-EP4, anti-Leu-M1, HEA-125, anti-carcino-embryonic antigen (CEA), anti-blood group-related antigens (anti-BGR A, B, H), B72.3, anti-placental alkaline phosphatase (PLAP), anti-vimentin and BMA-120 used to determine their value in the differentiation between pleural mesothelioma and lung adenocarcinoma. Lu-5, anti-cytokeratin-7 and -18, B 72.3 and PLAP reacted in a high percentage of cases with both mesothelioma and adenocarcinoma. Anti-CEA and anti-Leu-M1 did not react with any of the 27 mesotheliomas tested but showed a reaction in 75% (anti-CEA) and 66% (anti-Leu-M1) of the lung adenocarcinomas. Seventeen percent of the adenocarcinomas and 96% of the mesotheliomas showed a positive reaction with anti-vimentin. Ber-EP4 was demonstrated in all lung adenocarcinomas, but only in 2 mesotheliomas in a focal manner (7%). HEA-125 and anti-BGR A, B, H reacted with 83% (HEA-125) and 75% (anti-BGR A, B, H) of the lung adenocarcinomas. The statistical parameters, sensitivity and efficiency were estimated and a normogram for judging the diagnostic power of a single antibody for the differential diagnosis of mesothelioma versus adenocarcinoma was developed. According to this, Ber-EP4, HEA-125, anti-BGR A, B, H and anti-CEA were, in descending order, the most powerful discriminatory antibodies.
Adenocarcinoma↗
Diagnostic tools for differentiating pleural mesothelioma from lung adenocarcinoma in paraffin embedded tissue. II. Design of an expert system and its application to the diagnosis of mesothelioma.
A panel of 14 antibodies (panepithelial antibody Lu-5, anti-keratin-18, anti-keratin-7, Ber-EP4, anti-Leu-M1, HEA-125, anti-carcinoembryonic antigen, anti-blood group-related antigens A, B, H, B72.3, anti-placental alkaline phosphatase, anti-vimentin and BMA-120), which have been evaluated for use in differentiating mesothelioma from lung adenocarcinoma, was applied to a group of 24 suspected mesotheliomas. Using the established qualitative, descriptive criteria derived from monovariate statistical analysis of the tumour control groups (definite mesotheliomas, adenocarcinomas), a definitive allocation was possible in only 25% of suspected cases. We therefore constructed two "expert systems", based on multivariate discriminant analysis with either the ALLOC 80 program for ordinal data or a newly developed analysis program for binomial data. With these two systems diagnostic allocation of suspected mesotheliomas was improved to 75% and 79%. The use of binomial data ("positive" versus "negative") in conjunction with the probability-based test system is of particular interest because the primary data are easy to record and the test results have a higher statistical probability.
Adenocarcinoma↗
Telepathology with an integrated services digital network--a new tool for image transfer in surgical pathology: a preliminary report.
We describe a low-cost telepathology system working via a commercial integrated services digital network (ISDN) and consisting of modular software and hardware elements. The main elements are Apple Macintosh workstations; a software program for the simultaneous transfer of pictures, voice, and data; and procedures for image processing and general administration of all the information generated. Additionally, the system allows remote control of any peripheral instruments by a "picture-instrument manager." The transfer rate is currently 64 kbit/s; it will be extended to 128 kbit/s (ISDN basic rate) in the near future and to 2 Mbit/s (ISDN primary rate) in the next 2 years. The system was tested by the regional hospital in Samedan, Switzerland, and the Department of Pathology, University of Basel, Basel, Switzerland, a distance of 250 km, by offering a remote frozen section service to the regional hospital in 16 cases. Fifty-four to 58 seconds were needed for the transfer of a diagnostic 8-bit grey-level image containing 341 (median value) +/- 26.1 (standard error) kbytes (n = 13) or a diagnostic 24-bit color image containing 165 (median value) +/- 16.9 (standard error) kbytes (n = 3). The time required for a diagnostic session was between 25 and 35 minutes.
Adult↗
[Effect of various cytologic preparation techniques on form, texture and densitometric nuclear parameters of normal and dysplastic bladder urothelial cells].
An important prerequisite for densitometric and morphometric measurements on cytological specimens is the standardized cell preparation. Optimal results can only be achieved when the analyses are carried out on a regular monolayer of cell nuclei. Comparing the conventional cytological smear with a new centrifugation technique we demonstrate statistically significant differences of the two methods in texture, size and parameters describing the DNA content of normal and dysplastic urothelial cells.
Cell Nucleus↗
[Cytology and cytometry of breast cancer].
The cells of mammary carcinoma are obtained by means of fine-needle aspiration (FNA) and assessed by light microscopy. The cytologic diagnosis is supplemented by a steadily increasing series of various cytologic methods such as cytometry (morphometry and flow cytometry) as well as immunocytochemistry. This article deals with the basic principles of a correct FNA technique, its sources of error, and the pitfalls of cytologic differential diagnosis. The additive methods and some of their applications are presented briefly.
Biopsy, Needle↗
Densitometric and morphometric study of immunocytochemical estrogen receptors detection in breast carcinomas.
Immunohistochemical quantitative evaluation of estrogen receptors (ER) detected in tissue sections from 30 breast tumors by monoclonal antibody was performed using a densitometric method. In particular, ER concentration was calculated by nuclear mean optical density (nMOD), while heterogeneity in ER content was calculated by the coefficient of variation (CV) of the nuclear optical density histogram. Tumors which showed more than 60% of positive cells had a mean value of ER-nMOD of 0.116 +/- 0.002 a.u. and of ER-CV of 33.74 +/- 0.68. Tumors which showed 30% to 60% of positive cells had a mean value of ER-nMOD of 0.082 +/- 0.006 a.u. (arbitrary units) and of ER-CV of 36.25 +/- 3.44. Tumors showing less than 30% of positive cells had ER-nMOD of 0.052 +/- 0.009 a.u. and ER-CV of 48.49 +/- 5.61. These results indicate that the greater the concentration the lower the ER heterogeneity within the tumor sample. No significant differences between ER-ICA results, nuclear size and form factors were found.
Breast Neoplasms↗
Cytometry in histological sections of colon carcinoma.
A short description of a project of cytometry in histological sections of colon carcinoma is given with emphasis on the methodical aspects. Possible strategies of cytometric measurement and problems related to it (focus, overlap, segmentation of objects) are described. The main effort concerns interactive selection of tumor cells and the segmentation in cases of densely distributed and overlapping nuclei. All other succeeding processing steps are performed fully automatically. The resulting quantitative features are stored together with the original images on an optical disk for further examinations and reexaminations, allowing the direct relation of feature values to visual image content. The evaluation of the features as well as their interpretation is only at the beginning. Especially the problem of relating section information with true 3-dimensional information is not described here and necessitates further research. In a first investigation only a few tumors without and with metastases were analyzed. The preliminary results correspond with findings of Kunze et al.
Cell Nucleus↗
Age-related modification of average volume and anisotropy of vascular smooth muscle cells.
The aim of this study was to determine what changes in the arterial wall are related to age. In two groups of rabbits, one young and one adult, the aorta and carotid were studied using a morphometric approach based on stereological axioms and planimetric morphometry. The problem of anisotropy of smooth muscle cells is discussed in detail. Two forms of anisotropy must be distinguished, that of single cell and that due to the histological pattern of the smooth muscle cells in the arterial wall. Our results show in adult animals, as compared to the young ones, statistically significant decrease in anisotropy of the cell pattern which tends to become more regular. Moreover, in aorta and carotid of young and adult animals there is an increment of 95.39% and 80% of the absolute cell volume, respectively. We suggest that there may be a direct relationship between aging and phenotypical modulation of the smooth muscle cells and that the modification of the architectural cell pattern with age may represent an adaptive event related to the change in forces acting upon the arterial wall.
Aging↗
Morphological, immunohistochemical, stereological and nuclear shape characteristics of proliferative Leydig cell alterations in rats.
Proliferative Leydig cell (LC) alterations (hyperplasia, adenoma) of laboratory rats often pose diagnostic problems because the progression from normal to hyperplasia to neoplasia is continuous. The LC compartments of 130 Wistar rats (kfm: WIST strain) of approximately 2 years of age were examined. Ten typical cases conventionally classified as being normal or as showing diffuse or focal hyperplasia or small or large adenomata were investigated in more detail. In large adenomata, areas with large and small LC nuclei were identified. Immunohistochemical characterization, EM examination, as well as stereologic and planimetric investigations were performed. Hyperplastic and neoplastic LC essentially retained their normal appearance and immunohistochemical characteristics, but were found to contain more lipid droplets, fibroblast-like cells and patches of collagen than normal LC at the EM level. LC proliferation was accompanied by significant LC hypertrophy. LC nuclei of hyperplastic LC compartments were slightly larger while those of LC adenoma were markedly larger than nuclei of normal LC. The values for circle-related and ellipticity factors indicated that the nuclei of normal and hyperplastic LC were more markedly oval than nuclei of neoplastic LC. Concavity factor and bending energy measurements revealed that the small and oval nuclei of normal and hyperplastic LC had significantly more and deeper indentations than the larger and somewhat rounder nuclei of neoplastic LC. It is concluded that LC proliferations conventionally diagnosed as hyperplasia or adenoma on the basis of their size were composed of cytologically different LC populations.
Adenoma↗
The efficacy and tolerability of cyclosporine G in human kidney transplant recipients.
Twelve consecutive first cadaveric kidney transplant recipients received cyclosporine G (CsG)(initial dose 12 mg/kg per day) as basic immunosuppressive treatment along with prednisone (initial dose 0.5 mg/kg per day) for the first three months after transplantation. Thereafter CsG was replaced by Sandimmun (cyclosporine, CsA). Evaluation of the immunosuppressive efficacy and assessment of possible side effects of CsG was made and compared with the results in 38 historical control patients starting with the same dose of CsA as part of the same immunosuppressive dosage schedule. Statistically, there was no difference in patient survival at three (91% in CsG group versus 95% in CsA group) and twelve months (91% in CsG group versus 92% in CsA group), or in graft survival at three (75% in CsG group versus 89% in CsA group) and twelve months (75% in CsG group versus 84% in the CsA group). At equivalent oral doses of CsG and CsA significantly higher blood levels of CsG were observed (2P less than 0.05). Nephrotoxicity assessed by graft biopsy could be demonstrated to a similar extent in both groups, whereas hepatotoxicity was more pronounced during CsG treatment. Sequential measurements of bilirubin revealed a significant increase in all patients but median values were significantly higher in the CsG patients. A pronounced and concordant elevation of liver enzymes occurred during CsG treatment in three out of 12 patients. Liver biopsies performed in these patients revealed histological alterations consistent with toxic liver injury. Thus, in human kidney transplant recipients CsG and CsA appeared to be equally immunosuppressive and nephrotoxic but more hepatotoxic. On the basis of this limited experience we conclude that in human kidney transplant recipients CsG has no advantage over CsA.
Adult↗