Anna Kádár

Changes of Cell Adhesion and Extracellular Matrix (ECM) Components in Cervical Intraepithelial Neoplasia

Cell-cell and cell-extracellular matrix interaction is crucial in tumor progression. Tight junction (TJ) proteins as occludin and claudins (CLDNs) play important role in this process together with several extracellular matrix components, as syndecan. Our previous work suggested significant changes in the expression of claudins even in the early stages of cervical carcinogenesis. The aim of our present work was to study the expression of occludin and syndecan-1, as compared to CLDNs, in early phases of cervical carcinogenesis. Paraffin sections of 50 samples were studied by immunohistochemistry, including cervical intraepithelial neoplasias (CIN-I-II-III), in situ carcinomas (CIS) and normal cervical samples. Occludin and CLDN-2 were found colocalized in the basal layer, while syndecan-1 and CLDN-1, -4 and -7 were coexpressed in the parabasal and intermedier layers in normal epithelia. Intensity of occludin staining decreased in CIN/CIS lesions, although it was more extended towards the upper epithelial layers with inverse relation with grades, as seen in the case of CLDN -2 expression. CLDN -1, -2, -4 and -7 were detected in the entire epithelium in CIN, showing decrease in CIS. The progression of CIN was associated with reduced syndecan-1 expression, in contrast to CLDN -1, -4 and -7 which increased toward CIS. The obtained data suggest that significant changes occur in the composition of cell adhesion complexes even in early stages of cervical carcinogenesis. The pattern of expression is characteristic for the alteration, the changes in the different components, however, are not parallel with each other.

Tenascin expression and angiogenesis in breast cancers.

The expression and the distribution of tenascin as well as the extent of blood vessel formation (angiogenesis) were investigated in 70 invasive human breast carcinomas. Formalin-fixed, paraffin-embedded specimens were stained with monoclonal antibody against tenascin-C (DAKO and Biogenex). Anti-CD31 antibody (Biogenex), an acknowledged marker of stromal angiogenesis, was used to detect endothelial cells. Tenascin immunostaining was positive in the tumours around the persisting normal ducts, around tumour-cell nests, in the neostroma, in some tumour cells, and it was found in or around vascular channels. Tumour vascularity was assessed by quantitative vascular grading (Chalkley point count) and was related to the localization and intensity of tenascin immunoreactivity. 19 tumours (27.1%) were scored as low, 35 (50%) as medium, and 16 (22.9%) as having a high vascular grade. The positive correlation between the vascular grade and the tenascin immunopositivity in tumour stroma was observed. Our results suggest that tenascin expression may be associated with endothelial cell activation and may play an important role in tumour angiogenesis.

URINARY EXCRETION OF INDIVIDUAL 17-KETOSTEROIDS BY NORMAL CHILDREN.

Our knowledge of the functions of the normal and diseased adrenal cortex in adults is still slight and we know even less about it in newborn babies and in children. In the past few years an increasing number of methods for examining adrenal function have been described. In addition to the determination of the total amount of 17-ketosteroids (17-KS) and of 17-hydroxycorticoids (17-OH) excreted in urine, various methods for fractionating these compounds have been used, which are more suitable for studying normal function and various pathological mechanisms of the adrenal gland and of the gonads. Although data on adults exist, there is little information available on the determination of individual 17-KS from the urine of children. Therefore, it seemed to us useful to determine the urinary steroids in healthy children of various ages.

Arterial remodeling following mechanical injury: The role and nature of smooth muscle cells

The main feature of an atherosclerotic plaque is the formation of a new tissue in the arteries. In this respect atherosclerosis is similar to other conditions where non-neoplastic tissue formation occurs like in embryogenesis, in healing or in repair processes. A progressive intimal thickening occurs in the early phase of human atherosclerotic lesions and also in certain experimental models. Long-standing aortic intimal thickening could be induced by mechanical injury to the inner surface of the aorta with a microsurgical instrument, which causes controlled endothelial denudation. The injury is followed by an arterial remodeling. The latter process is caused by the development of an intimal plaque which consists of two main components: the smooth muscle cell (SMC) and the intercellular matrix. The matrix components are mostly synthetized by the SMC. Two distinct SMC populations could be distinguished by morphological means in the intimal proliferation: the synthetizing type and the proliferating type. Their role will be discussed and their morphological appearance will be compared with SMC present in other lesions.

Chlamydia pneumoniae in different coronary artery segments in the young.

UNLABELLED Chlamydia pneumoniae has emerged as the most likely pathogen to have a causative role in the development and/or for progression of atherosclerosis. Evidence for this is based on epidemiological and pathological studies. In an effort to better understand the significance of finding C. pneumoniae in atheromata, we examined coronary artery segments of young adults (15-34 years) with and without atherosclerosis. Left anterior descending coronary arteries (LAD) of 74 young adults who died suddenly were examined histologically and for the presence of C. pneumoniae by immunohistochemistry. C. pneumoniae was identified in advanced lesions (Stary types III to VI) in 17 of 32 cases (53%), and in early lesions (Stary type I-II) in 8 of 37 cases (21%), mainly at the proximal segments of the LAD. C. pneumoniae was not found in the intimal and medial layer of normal-appearing coronary arteries. C. pneumoniae was detected in the adventitia in 51 (67%) coronary arteries: in 27 of normal arteries and early lesions (64%), and in 24 of atherosclerotic lesions (75%). C. pneumoniae was found most often in macrophages, less offen in smooth muscle cells. We also observed a correlation between C. pneumoniae positivity and cigarette smoking. IN CONCLUSION C. pneumoniae may relate to the severity of atherosclerosis in young people, and it may thus initiate atherosclerotic injury or facilitate its progression with other risk factors.

Formation of Collagen-Like Fibrils from α-Elastin

Collagen-like structures were formed in solutions of alpha-elastin after heating to 57 degrees C and after treatment with absolute ethanol. A complex between acetyl-alpha-elastin and cetyltrimethylammonium bromide showed a similar structure. Thick fibrils (diameter approximately 100 nm), resembling those described by Volpin, et al.12 revealed transversal banding with periodicity of 39 to 62 nm. A possible mechanism for the formation of these fibers is suggested based on hydrophobic interactions.

Development of present and future of telepathology in Hungary

Pathologists in Hungary evaluate several hundred thousand histological specimens yearly, and a second opinion is requested in 5–10 percent of cases. Application of multimedia systems (i.e. telepathology) is convenient and efficient to establish a correct diagnosis in such cases. The first telepathology connection in Hungary has been established between the 1st Department of Pathology and Experimental Cancer Research, Semmelweis University and the Department of Pathology, Central Hospital of the Ministry of the Interior. Further development occurred in the course of various projects, supported by the EU (Interpath, Retransplant, BePro): new stations were established in three university institutes and six county hospitals. Electronic fixation of the images and their transmission by telephone line (ISDN) is easily available and an important feature of the multimedia system applied in telepathology. The system used by us is suited to evaluate frozen or paraffin-embedded histologic sections, as well as immunohistochemical and cytologic specimens, if necessary supplemented with transmission of macroscopic pictures. Our experience with bilateral consultations has proven the importance of telepathology. The telepathology system established in Hungary is now ready to join the telepathology network of the EU.

Ultrastructural investigations of finger pulp biopsies: a study of 31 patients with Raynaud's syndrome.

Finger pulp biopsies of 31 patients suffering from Raynauds syndrome (RS) were investigated by light and electron microscopy. The patients suffered from various underlying diseases. Interest was focused on the vascular changes and nerve and connective tissue alterations, especially the elastic fiber changes. In the dermal capillaries, endothelial swelling, narrowing of the lumen, increased numbers of intracytoplasmic filaments and Weibel-Palade bodies, and various types of basement membrane alterations were observed. The basement membrane of the unmyelinated nerves showed similar alterations to the capillary basement membrane. Severe degenerative changes were found in the myelin sheath of the myelinated axons. In the dermal connective tissue, severe elastotic degeneration and alterations of the collagen fibers were observed. The data probably represent the ultrastructural picture of the end stage of this syndrome.

Early Atherosclerosis and Chlamydia Pneumoniae Infection in the Coronary Arteries

In non-atheromatous segments of coronary arteries a sequence of preatherosclerotic changes was identified which consisted of medial thickening followed by intimal thickening. More recently, Chlamydia pneumoniae seropositivity was associated with enhanced intima-media thickness of arteries. In the present study the intimal and medial thickness of coronary artery of young adults were measured, and were correlated with the presence of Chlamydia pneumoniae antigens. Proximal and distal segments of the left anterior descending coronaries (LAD) obtained at autopsy from young adults (15–34 years) were studied. The thickness and cellular density of the intima and of the media without clear-cut atherosclerotic changes were measured by image analysis. The hypertrophy index was calculated as the ratio of cell density and the thickness of the respective layer. Atherosclerotic lesions occurring elsewhere in the same coronary were noted and graded by severity. The presence of Chlamydia pneumoniae verified by immunohistochemistry was correlated with the severity of lesions and with the hypertrophy index. In the proximal segments, atherosclerosis of LAD was associated with the widening of both the intima and the media of lesion free-sites. In the distal coronary segments the proportion of the intimal thickening had a significant association with atherosclerosis. Compared to non-infected arteries, Chlamydia pneumoniae infection was associated with higher hypertrophy index in the intima as well as in the media. The rate of Chlamydia pneumoniae positivity increased with the severity of lesions. As a conclusion: in the LAD coronary, the intimal thickening is the main preatherosclerotic change. Chlamydia pneumoniae may favour arterial wall hypertrophy and plays a role in lesion progression.

Connexin 43 expression in rat aortic smooth muscle after ovariectomy and hormonal replacement.

The purpose of this study was to determine the effects of ovariectomy and long-term combined sexual hormone replacement on the gap junctional protein, connexin 43 (Cx43) of aortic medial smooth muscle cells in rats. Twenty non-pregnant mature Wistar female rats were divided into five groups (four animals in each group). Group A underwent ovariectomy, Group B underwent ovariectomy and received estradiol propionate, Group C underwent ovariectomy and received medroxyprogesterone acetate and Group D underwent ovariectomy and received both hormones. Group E was sham-operated and used as control. After 15 weeks of treatment, thoracic aortas were removed and immunohistochemistry was carried out using a specific fluorescent antibody against Cx43. Tissue sections were examined by confocal laser scanning microscopy and analysed by the Scion Image program. All five different groups had the same distribution and extent of Cx43 in the aorta. Neither the ovariectomy nor the hormone replacement had any effect on the Cx43 expression of aortic smooth muscle cells in rats as compared to control animals. These results indicate that sexual steroids do not influence the gap junctional protein Cx43 of the medial layer of aorta in rats. They may suggest that the beneficial effects of estrogen are not mediated via gap junctions in the human aorta either.