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Biomedical subjects

H Guski

Publications and source records attributed to H Guski.

At least 19 recordsLinked to original sources
PubMed1995

Chromatin structure analysis based on a hierarchic texture model.

The quantification of chromatin structures is an important part of nuclear grading of malignant and premalignant lesions. In order to achieve high accuracy, computerized image analysis systems have been applied in this process. Chromatin texture analysis of cell nuclei requires a suitable texture model. A hierarchic model seemed to be most compatible for this purpose. It assumes that texture consists of homogeneous regions (textons). Based on this model, two approaches to texture segmentation and feature extraction were investigated using sections of cervical tissue. We examined the reproducibility of the measurement under changing optical conditions. The coefficients of variations of the texture features ranged from 2.1% to 16.9%. The features were tested for their discriminating capability in a pilot study including 30 cases of cervical dysplasia and carcinoma. The overall classification accuracy reached 65%. This study presents an automated technique for texture analysis that is similar to human perception.

Carcinoma in Situ↗
PubMed1994

Measuring of AgNORs using image analysis.

A method is presented for the measurement of AgNORs in histological section using an image analysis system. Measurements are performed at the highest magnification (objective 100x) using a CCD camera. In the first step the AgNORs are segmented, counted and measured. In the second step the AgNOR clusters are segmented. Several features for the description of the AgNORs, the AgNOR clusters and their spatial distribution throughout the nucleus are given. As an internal reference, lymphocytes are used and the size features are given relative to the mean size of AgNORs in the lymphocytes. The reproducibility of the features was tested on a series of astrocytomas. This should be carried out with at least 150 tumor cells and 20 reference cells in order for accurate measurements.

Astrocytoma↗
PubMed1993

Intracellular penetration of ruthenium red in embryonic nervous tissue.

Electron microscopic investigations, using ruthenium red revealed that dye is usually observed in immature neuronal cells in autonomic ganglia of rat embryos and fetuses. Ruthenium red does not penetrate undamaged neurons in mature ganglia. Ruthenium red positive material covers neuronal cell plasmalemma even in early primordial phases of autonomic ganglia. Plasmalemma of growth zones does not react with ruthenium red. Intracellular penetration of immature neurons by ruthenium red, according to expectation, depends on damage to cell membrane due to the fixation procedure, especially in the growth zones.

Animals↗
PubMed1992

Neurohistochemical and electron microscopic investigations of pathological and age-related changes in the cardiovascular system.

Neurohistochemical and electron microscopic investigations of the autonomic nervous system (ANS) of man and animals suggest that its ontogenesis can be divided into the premediatory, mediatory and postmediatory periods of development. The postmediatory period begins heterochronically in various ganglia of the ANS. A normal process of early cardiac desympathization usually occurs at the age of 35 to 60 years. Specific changes of preceding sudden cardiac death are elicited in different parts of the ANS and adrenal glands. This is accompanied by focal myocardial desympathization. Coronary vessels and conducting system which may influence myocardial hypersensitivity zones to catecholamines are involved in the process of destabilization of the cardiac function. Moreover, relationships are demonstrated which exist between the atherosclerotic lesions of the aortic wall and the status of its nerve plexuses.

Adult↗
PubMed1992

Coronary atherosclerosis and hair elements contents. A correlation study of 102 autopsy subjects using the energy dispersive X-ray fluorescence analysis and applying an atherometric system.

An atherometric system (AS) was used to study the coronary atherosclerotic lesions of a consecutive series of 102 autopsies divided into two groups according to the principal cause of death, the myocardial infarction and the low atherosclerosis groups, respectively (MIG 67 cases, LAG 35 cases). The hair elements contents (K, Ca, Zn, Br, Sr, Pb, S, Cl, Cu, and their rates Ca/Sr, Zn/Cu and Ca/K) were determined by energy dispersive X-ray fluorescence (EDXRF) analysis. A PEARSON correlation analysis was done between each element and the following descriptive arterial variables of the AS: fatty streaks (X), fibrous plaques (Y), severe (complicated plus calcified) plaques (Z) and total atherosclerosis (sigma) and the three weighted indices of the AS: obstruction (omega), stenosis (P) and benignity (B). These variables were obtained from the three major epicardial branches of the coronary arteries (right RC, left anterior descending LAD and left circumflex LC). From a total of 189 possible correlations between the 9 elements and their 3 combinations and the 7 variables of the AS in the three coronary arteries, 86 (45.5%) were significant. The fatty streak was the best correlated variable. It correlated with all elements with the only exception of chloride. The fibrous plaque was poorly correlated. The severe plaques and total atherosclerosis correlated mainly with Zn and Pb in the MIG and Sr in the LAG. The weighted indices have the same behaviour. Also some correlations were found between K, Ca, Zn, Br, Sr, Pb, Ca/Sr, Zn/Cu and Ca/K ratios with some of the variables of the AS in each coronary artery.

Autopsy↗
PubMed1991

Morphometric, histochemical and autoradiographic studies on myocardial cells in experimental cardiac hypertrophy and ischemia.

Experimental studies were conducted into 170 adult male Wistar rats for the purpose of analysis of cellular adaptation processes of the myocardium to acute ischemia. One group of the animals were exposed to physical endurance training, i.e. 180 h of swimming exercises, up to 3 h daily. Positive verification of cardiac hypertrophy was considered a measure of accomplished cellular adaptation. Training-induced increase of relative and absolute heart weight was 25 and 30%, respectively. Acute myocardial ischemia had been produced by ligature of the left coronary artery. There were no significant differences between trained and untrained animals for incidence and size of infarction and postoperative lethality, while cardiac decompensation was less often recorded from trained animals. To study cellular adaptation as well as differences between trained and untrained animals, tissue samples were taken from the non-ischemic part of the left ventricle and checked by means of histology, electron microscopy, morphometry, quantitative histochemistry, and histo-autoradiography 1, 2, 4, 7, and 14 days after occlusion of the coronary artery. The studies have shown endurance training to result in unambiguous modification of structural as well as functional response of the nonischemic heart. Included in such structural modification at cellular level are significant changes in mitochondrial membranes, sarcoplasmic reticulum, and T-system. Structural modification was reflected in changes to the oxidative enzymes and DNA metabolism. Different patterns of cellular reaction could be positively verified up to 14 days after myocardial infarction.

Animals↗
PubMed1991

[Significance of interdisciplinary cooperation in surgical therapy of noninvasive breast carcinoma].

Non-invasive mammary carcinoma can be surgically treated with preservation of the breast even without adjuvant radiotherapy, if all necessary conditions are provided, such as accurate indication, absence of multicentricity, no involvement of mamillae except of Paget's disease, tumour diameter not more than 20 mm as well as efficient and systematic performance of intraoperative diagnostic histology. An analysis of the author's own surgical findings revealed multicentricity in 16% of all cases of intraductal carcinoma. Breast-preserving operations could be performed on 63% of the patients. Local recurrences were recorded from 13% of all cases reviewed. The rate of breast-preserving operations with lowest possible rate of recurrence, by all accounts of experience, can be enhanced only by close interdisciplinary cooperation among radiologists, surgeons, and pathologists.

Breast Neoplasms↗
PubMed1991

[Frequency distribution, microscopic image analysis and grading of mammary carcinoma].

The frequency of diagnoses of breast diseases in 1685 patients was examined on the basis of biopsy material at the Institute of Pathology of Charité Hospital in Berlin, during 1984-1987, with particular consideration of histological types of mammary carcinomas. Breast cancer was detected in 562 patients of whom 429 had undergone operations according to standardized recommendations by the Charité Department of Surgery. Histological tumor classification, postoperative staging and, in cases of invasive ductal carcinoma, also histological grading were part of the pathologico-anatomic investigation. Reproducibility of grading was 72.7% for intra-observer examination and 63.3% for evaluation by different pathologists. A group of 20 premenopausal patients with tumors staged as pT1, pN0 was selected for morphometric studies and objectivation of tumor grading. HE-stained paraffin sections were made for conventional grading according to Bloom and Richardson (1957), whereas Feulgen reaction in 4 microns thick sections was used for quantitative examination by means of a microscopic image analysis system (Robotron A6471 with AMBA/R software). The measuring program used was based mainly on evaluation of karyometric features. Measurements were concentrated on analysis of the chromatin structure of tumor cell nuclei. Correlations with histological grading were found to exist for 16 features out of 28 parameters selected for statistical analysis. Some new parameters of the texture of tumor cells nuclei were demonstrated to be strongly correlated with the degree of tumor differentiation. The prognostic significance of nuclear texture features has to be proved by further studies in which clinical data of the course of the tumor disease must be included.

Adult↗
PubMed1991

Atherosclerosis in diabetes and hypertension. A comparative morphometric study of their progression using an atherometric system.

The three major epicardial coronary arteries of a set of 472 autopsy cases divided into four groups: a) non-diabetics and non-hypertensive, 322 subjects; b) hypertensive, 75 subjects; c) diabetics, 57 subjects and d) hypertensive and diabetic, 17 subjects, were studied. Classical pathomorphological procedures and an atherometric system (AS), suitable to characterize the atherosclerotic lesions, was used searching for differences between the level of atherosclerosis into these four groups and its eventual progression according to the time of evolution of these diseases. Raw data processing was full automated and some univariate and multivariate statistical procedures (means, standard deviations, ANOVA, MANOVA and principal components analysis) were performed using two commercial statistical packages: "NCSS" and "SYSTAT". The most remarkable findings were the following: Diabetes and hypertension have both strong impact upon the rate at which the atherosclerotic process takes place in subjects affected by these diseases. The time of evolution of both diseases correlates positively and independently of age with the velocity of the atherosclerotic process at the three coronary arteries. The impact of diabetes seems to be stronger and is particularly expressed by the severe plaques (Z) while the effect of hypertension is specially observable at the fibrous plaques (Y). There seems to be no significant interaction (synergism) between the two risk factors upon the measurement of the atherosclerotic lesions, that is, they have an additive effect. Two simple underlying factors can be used to account for interindividual differences. These two factors are "dominated", respectively, by fibrous (Y) and severe plaques (Z).

Analysis of Variance↗
PubMed1991

Atherosclerotic lesion of the circle of Willis: its study applying an atherometric system using multivariate statistical techniques.

In 2043 autopsies divided into the high (HAG) and low (LAG) atherosclerosis group a set of variables of a new atherometric system (AS) was used to characterize the atherosclerotic lesion (AL) in the circle of Willis arteries: fatty streaks (X), fibrous plaques (Y), severe plaques (Z), index of stenosis (P) and index of benignity (B). Principal component analysis identified a first component of severity (Y, P and Z) and a second component of benignity (X and B). Fibrous plaques play the main role in the severity of AL in the circle of Willis. The new AS proved its usefulness in characterizing the state of AL, whereas discriminant analysis and AS distinguished between the HAG and the LAG. The classification was correct in 74.5% and 76.5% when using three (X, Y, Z) and five (X, Y, Z, P, B) variables, respectively.

Arteriosclerosis↗
PubMed1990

[Histotopographic and morphometric studies of the intramural coronary arteries in the trabecula septomarginalis of swine and pigmy goats].

Up to six arteries traverse from the interventricular septum to the M. papillaris magnus in the trabecula septomarginalis (moderator band) of swine and pygmy goat. Musculo-elastic intimal thickenings, many of them quite extensive, are recordable from along the entire length of all these intramural coronary arteries which are between 50 microns and 300 microns in diameter. The conclusion may be drawn from the results of morphometric analysis that coronary arteries undergo enlargement in response to increased intimal thickening and that such enlargement does not lead to narrowing of the lumen. Peculiarities in wall structure of the arteries in the trabecula septomarginalis are interpreted as adaptive processes of the vascular wall to the extraordinary stress on those vessels.

Animals↗
PubMed1989

[Lumpectomy with axillary lymph node excision and subsequent irradiation of the small breast cancer].

The technique of lumpectomy with axillary lymphonodectomy and postoperative irradiation is discussed in this paper and is compared to quadrantectomy or bilaterally restricted subcutaneous mastectomy in cases of small-size mammary carcinoma. A critical appraisal is made of the authors' own concept of indication, with reference being also made to the problem of the non-invasive form.

Breast Neoplasms↗
PubMed1989

[Automated microscopic image analysis and the prognosis of preneoplasms and carcinomas of the mammary gland].

Studies of preneoplasias and carcinomas of the mammary gland have been conducted by means of automated microscopic image analysis, on the basis of previous results as well as with references to the international literature, for 2 purposes: 1. Determination in the context of a clinical follow-up study of the individual carcinoma risk for patients with proliferative fibrocystic breast disease (mastopathy) and 2. Preparation of an objective automated grading of ductal breast carcinomas for better assessment of prognosis. Against the background of the assumption that the majority of carcinomas and precancerous lesions of the breast originate from the terminal ductal lobular unit, an effort is made to determine, independent severity of the mastopathy, the biological valence of solid, cribriform, and papillary ductal epithelial proliferations (no, possible or inevitable preneoplasia). Proliferation patterns without and with atypical features are checked for their similarity with intraductal and invasive carcinomas (similarity principle) and are additionally examined for differences, depending on localization and distance from tumour (topological principle). Automated histological tumour grading is to distinguish with greater subtlety within the large heterogeneous group of moderately differentiated carcinomas and is to objectify and thus facilitate the difficult task of delimitation of moderately and poorly differentiated carcinomas. Nuclear grading will be the major basis for classification along these lines. Objectified and reproducible tumour grading is believed to be extremely helpful in better prognostication of breast cancer.

Breast Neoplasms↗
PubMed1989

The PARTICLE expert system for tumor grading by automated image analysis.

While automated microscopic image analysis of histologic sections has been helpful in objectivizing histologic tumor grading and investigating the relationships between grading and prognosis, expert systems have the potential of linking image analysis and other data for statistical analysis and application to a wider range of tumors. One such expert system is PARTICLE, whose development was based on many years of experience in resolving histologic problems by image analysis. This paper discusses the philosophy of expert system for tumor grading and describes its implementation in the PARTICLE system. The system's structure, operations and applications are briefly presented. PARTICLE is essentially based on the evaluation of karyometric data.

Cell Nucleus↗
PubMed1989

Comparison of conventional morphometry and image analysis for the solution of histomorphometric problems.

The main differences between conventional morphometry and image analysis for their application in histopathology are pointed out. Conventional morphometry allows the use of contextural informations and a priori knowledge in a convenient manner. This is the most complicated thing in image analysis. The solution of this problem lies on the field of artificial intelligence. On the other hand, image analysis is able to measure densitometrical and textural features, to determine arbitrary quantiles and moments of feature distributions, to match scenes. Therefore the descriptive power of image analysis is much higher than the power of conventional morphometry.

Humans↗
PubMed1989

Coronary atherosclerosis in sudden death: a comparative study applying an atherometric system.

Coronary arteries affected by atherosclerosis and its myocardial related damage in cardiac and non-cardiac sudden death subjects (152 and 98, respectively) including a low atherosclerosis group (250 subjects) were studied in autopsy material applying a new well standardized atherometric system. A high statistical significance of all variables of this system was found between the groups studied.

Adult↗