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Biomedical subjects

H Guski

Publications and source records attributed to H Guski.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Stereotactic tumor biopsy and tumor excision].

Stereotactic procedures are indicated in nonpalpable breast lesions that are suspicious in mammography. Using the ABBI system all established procedures (stereotactic needle biopsy, fine needle biopsy, core needle biopsy) can be performed. Also the resection of cylindrical tissue specimen with a maximum diameter of 20 mm can be carried out, controlled by digital mammography. For the exact diagnosis of lesions with a diameter up to 15 mm, cylindrical extirpation is recommended. In several cases this can be considered as definitive lumpectomy. Neither lesions localized close to the thoracic wall nor retromamillary lesions can be treated by using the ABBI system. While digital mammography is the method of choice for the detection of microcalcifications, the visualization of opacifications may be difficult. Overall the ABBI system was used in 40.7% of our patients with nonpalpable breast lesions.

Biopsy, Needle↗
PubMed1997

Detection of malignant and benign breast lesions with an automated US system: results in 120 cases.

PURPOSE: To evaluate clinically an automated ultrasound (US) system for detecting benign and malignant breast lesions. MATERIALS AND METHODS: A prototype automated US system was used to examine 119 patients: 38 patients with 39 proved malignant breast lesions (7-50 mm), 41 patients with 41 proved benign breast lesions (8-40 mm), and 40 patients without breast lesions. The device yields a three-dimensional set of B-mode scans and reconstructed US images comparable to mammograms. All patients had undergone mammography. Four radiologists who had not performed the examinations independently assessed the mammograms and US images to detect benign and malignant breast lesions. RESULTS: Each of the four readers did not recognize one to three detectable malignant lesions on mammograms, one to two detectable malignant lesions on US images, two to four detectable benign lesions on mammograms, and five to seven detectable benign lesions on US images. All readers identified the 39 cancers with at least one of the modalities. The 40 cases without lesions were diagnosed correctly more frequently on the US images by three readers and on the mammograms by one reader. CONCLUSION: Depiction of breast lesions at automated US is reproducible. Automated US is complementary to mammography.

Breast Diseases↗
PubMed1997

[Minimal invasive surgery in clinically occult breast carcinoma].

The ABBI (Advanced Breast Biopsy Instrumentation) system is a new method of breast surgery of nonpalpable tumors which permits intraoperative mammography. In a pilot study it was shown that a small carcinoma can be removed by a mammographically and stereotactically controlled biopsy (20 mm maximum diameter). An indicated breast-conserving therapy can be carried out when using this method.

Biopsy↗
PubMed1996

A defined chromosome 6q fragment (at D6S310) harbors a putative tumor suppressor gene for breast cancer.

Recent evidence obtained by cytogenetic and molecular studies indicates that in breast cancer chromosome 6q is often affected by genetic changes suggesting the existence of putative tumor suppressor genes (TSGs). However the function of gene(s) on this chromosome in breast cancer suppression is not understood. To substantiate further the presence of breast cancer related TSGs at 6q and to define their location, we first performed microcell-mediated transfer of chromosome 6 to CAL51 breast cancer cells for studying possible suppression of malignant phenotype and secondly, we analysed DNAs from 46 primary breast cancers for loss of constitutive heterozygosity (LOH) using 24 poly-morphic microsatellite markers. The chromosome transfer resulted in loss of tumorigenicity and reversion of other neoplastic properties of the microcell hybrids. Polymorphism analysis of single hybrids revealed that they harbored only a small donor chromosome fragment defined by the marker D6S310 (6q23.3-q25) and flanked by D6S292 and D6S311. The LOH data suggest that four tumor suppressor gene loci mapped to the central and distal portion of 6q may be independently deleted in breast cancer. One of these regions corresponds to the region identified by chromosome transfer.

Breast Neoplasms↗
PubMed1996

Overexpression of the death-promoting gene bax-alpha which is downregulated in breast cancer restores sensitivity to different apoptotic stimuli and reduces tumor growth in SCID mice.

We have studied the expression of members of the bcl-2 family in human breast cancer. The expression pattern of these genes in breast cancer tissue samples was compared with the expression pattern in normal breast epithelium. No marked difference with regard to bcl-2 and bcl-xL expression was observed between normal breast epithelium and cancer tissue. In contrast, bax-alpha, a splice variant of bax, which promotes apoptosis, is expressed in high amounts in normal breast epithelium, whereas only weak or no expression could be detected in 39 out of 40 cancer tissue samples examined so far. Of interest, downregulation of bax-alpha was found in different histological subtypes. Furthermore, we transfected bax-alpha into breast cancer cell lines under the control of a tetracycline-dependent expression system. We were able to demonstrate for the first time that induction of bax expression in breast cancer cell lines restores sensitivity towards both serum starvation and APO-I/Fas-triggered apoptosis and significantly reduces tumor growth in SCID mice. Therefore, we propose that dysregulation of apoptosis might contribute to the pathogenesis of breast cancer at least in part due to an imbalance between members of the bcl-2 gene family.

Animals↗
PubMed1996

Neuroectodermal cyst may be a rare differential diagnosis of fetal sacrococcygeal teratoma: first case report of a prenatally observed neuroectodermal cyst.

In spite of the fact that most anomalies can be accurately diagnosed prenatally, one may be confronted with an extremely rare fetal abnormality that has never been described before. We report a case of a neuroectodermal cyst arising from the posterior neuropore. After 21 weeks of gestation a fetal anechoic intra- and extra-abdominal tumor was detected. The mass grew to 75 x 41 x 33 mm at 35 weeks. Initially it was believed to be a sacrococcygeal teratoma. Serial scans and Doppler ultrasound examinations were performed, which demonstrated fetal well-being. Color Doppler imaging failed to demonstrate increased tumoral perfusion. After elective Cesarean section, the tumor was excised. The postoperative course was complicated by recurrent infections of the urinary tract due to neurological damage to the bladder. There was also impaired function of the anal sphincter. The histological finding of a monolayer of neuroepithelial cells and melanocytes led to the diagnosis of a neuroectodermal cyst.

Adult↗
PubMed1996

[AgNOR analysis of astrocytoma in childhood].

To evaluate the malignant potential of a tumor, data about its proliferative rate are essential. In this study clinical data, histological grading and immunohistochemical marker PCNA were applied on astrocytomas in childhood and were correlated to number, size and distribution of AgNORs. Tumor material from 90 patients, aged 1 to 15 years, was available. Histological grading, immunohistochemistry and AgNOR staining were performed on paraffin sections. PCNA-positivity was evaluated semiquantitatively. The AgNORs were quantified on 100 nuclei/case with an image analysis system. With aggravating malignancy we could show a shorter anamnesis, a lower survival and a higher PCNA-reactivity. We found a strong correlation between several AgNOR-features and the grade of malignancy of the astrocytomas, especially for the number of the AgNORs (from grade I: 1.73 AgNORs/nucleus to grade IV: 4.56 AgNORs/nucleus), the size of the AgNORs and its area amount of the nucleus. There were correlations between AgNOR-number and PCNA-reactivity as well as AgNOR-number and survival. Analysis of AgNORs, consequently, should provide prognostically relevant information helpful in more effective grading of astrocytomas.

Adolescent↗
PubMed1996

[Surgery of breast carcinoma in the elderly woman].

From our experience the age of the patient does not seen to be a contraindication to surgical therapy of breast cancer. There was no statistically significant difference in the tumor staging between patients younger than 75 years and patients older than 74 years. Although radical surgery was not possible in all cases of patients older than 74 years because of general risk factors, there was not statistical difference in the survival rates of patients younger than 75 years.

Adult↗
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↗
PubMed1994

[Fibromatosis of the breast--a case report and review of the literature].

A case of fibromatosis of the breast mimics a carcinoma by its clinical and mammographic features. The morphological image of this rare disease of the breast is described. The fibromatosis of the breast has to be distinguished histologically from a fibroma and from a low-grade fibrosarcoma. The dignity of the lesion is confirmed by histological and immunohistochemical examination. The possibilities of therapy are discussed and compared with data of the literature.

Biopsy↗
PubMed1994

Inclusions similar to Hirano bodies in urinary bladder neurons of dogs.

Unusual intracytoplasmatic inclusions were found in urinary bladder neurons in dogs. The plate-like inclusions were composed of thin filaments, and when viewed en face, appeared as oval or angular bodies with regular lattice work array. When viewed in a transverse section, they were of rod-like shape and were composed of longitudinal filaments and transverse bars. The inclusions were observed in all ganglia of the urinary bladders studied. Three-dimensional reconstruction of the inclusions was made, using a tilting device. By means of this reconstruction, it could be demonstrated that their ultrastructure is similar to that of Hirano bodies which occur in human neurons of the central nervous system in cases of neurodegenerative diseases. The authors suggest that unusual intraneuronal inclusions represent a peculiarity in cytoskeletal protein assembly typical of canine urinary bladder neurons.

Animals↗
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↗
PubMed1993

Coronary atherosclerosis and chemical trace elements in the hair. A canonical correlation study of autopsy subjects, using an atherometric system and the X-ray fluorescence analysis.

An atherometric system (AS) was used to study coronary atherosclerotic lesions of a sample of 73 autopsy subjects. The content of nine chemical elements in the hair (K, Ca, Zn, Br, Sr, Pb, S, Cl, Cu) and the rates Zn/Cu and Ca/K were determined by energy dispersive X-ray fluorescence (EDXRF) analysis. Some canonical correlation analyses (CCA) were made of different combinations of chemical elements contents and of the following descriptive arterial variables of As: fatty streaks, fibrous plaques, severe (complicated plus calcified), plaques, and total atherosclerosis and the three weighted indices of AS, i.e. obstruction, stenosis and benignity. The arterial variables were obtained from the three major epicardial branches of the coronary arteries. Similar CCA analyses were performed to correlate chemical elements of the hair with some heart variables of AS, such as heart weight and estimated total volume of myocardium damaged by fibrosis and/or necrosis. The most remarkable results were as follows: Combinations of Pb, Ca/K, Zn/Cu and Fe, Ca/K, Zn/Cu were always strongly correlated with fatty streaks, fibrous plaques and severe plaques of the three coronary artery branches and the total coronary artery system, with the only exception of the left circumflex coronary artery when Fe was included. Similar results were recorded from obstruction, stenosis and benignity indices of AS. These two combinations of chemical elements were also correlated with the heart variables of AS. When the group of elements was integrated by Br, Ca/K, Zn/Cu, there were significant results with the heart variables, but not with the arterial variables of the AS.

Autopsy↗
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↗