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Biomedical subjects

V Rychterová

Publications and source records attributed to V Rychterová.

At least 19 recordsLinked to original sources

Protracted infection of pacemaker leads with development of large vegetations: three years follow up. Case report.

A case history of a patient with permanent pacemaker reports inaccurate diagnosis of inflammation at the site of operation wound and a protracted infection of pacemaker leads. Inadequate therapy led to protracted inflammation with the leads fixed in the superior vena cava and the development of large vegetations in the right heart. Finally, the condition was resolved by surgical explantation and long-term antibiotic therapy. This case history describes infectious complications related to the implantation of a permanent pacemaker and the role of echocardiography in diagnosis of vegetations and points out the surgical treatment as a method of choice.

Aged↗

Marjolin's ulcer.

In 1828 John Nicolas Marjolini characterized ulcer with malignant degeneration which developed in scars after burns, but it occurs under varying clinical conditions. Typical feature is the latent period (on average 30 years). It is encountered in 2 forms: a shallow ulcer or exophytic tumour, most frequently on the lower extremities. At the Prague Burn Centre 11 patients were treated since 1978 till 1998. A unique case was a man suffering from congenital form of epidermolysis bullosa who developed Marjolin's ulcer on his foot (histological examination confirmed well differentiated squamous cell carcinoma). After 4 years he died with extreme cachexia and metastatic spread of the tumour, because he refused repeatedly amputation and lymph nodes dissection. To prevent Marjolin's ulcer several recommendations are presented.

Adult↗

Clear cell malignant myoepithelioma of the salivary glands.

Previous reports of monomorphic clear cell carcinoma of the salivary glands have shown inconsistent results with immunohistochemistry, especially for S-100 protein, and this has led to uncertainty about the nature of these tumours. We believe that much can be explained by considering this group as comprising not one but two separate neoplasms, one epithelial and the other myoepithelial. The former has been described as hyalinizing clear cell carcinoma--it generally occurs in the minor salivary glands, and strongly expresses cytokeratins but not S-100 protein or alpha smooth muscle actin. In contrast, this study presents five primary malignant tumours of the major salivary glands also composed largely of a single population of clear cells, but displaying histological and immunohistochemical features of myoepithelial differentiation, such as the formation of collagenous spherules and expression of S-100 protein and actin. A small number of similar tumours have been reported previously. We, therefore, believe that these neoplasms represent a clear cell variant of malignant myoepithelioma (myoepithelial carcinoma).

Actins↗

Formation of the heart loop and proliferation structure of its wall as a base for ventricular septation.

Controversial criteria for definition and classification of univentricular hearts are discussed from the point of view of proliferation pattern in the wall of heart tube and heart loop stage. The persistence of the primitive diffuse proliferation structure is the condition for the development of univentricular heart in which the morphogenetic mechanism forming the ventricular septum does not operate. Pseudouniventricular heart, i.e. the heart with the large main chamber accompanied by a small accessory cavity, is the result of total or partial right or left hypoplasia in which the extent of operation of the above mentioned mechanism is determined by the degree of ventricular hypoplasy. The morphogenesis of the heart wall structure and relief including the atrioventricular and arterial valves is a secondary feature, mostly dependent on the changed hemodynamic conditions.

Diagnosis, Differential↗

Isoproterenol-induced necrotic lesions of embryonic heart tissue.

Chick embryos were used for analyzing the effect of isoproterenol on the embryonic heart. Isoproterenol (2 x 80 mg/kg in 48 hrs) was injected into the amniotic sac from the 5th embryonic day to the time of hatching. From the 5th to the 7th embryonic day (ed), transposition of great vessels occurs. From the 7th to the 14th ed, blockade of development of coronary vascularization was regularly observed, particularly in the ventral wall of the right ventricle. This effect is always associated with persistence of intertrabecular spaces in the nonvascularized area and with a higher water content in the heart. From the 10th to the 12th ed, degenerative changes of the cardiac musculature can be observed. Lesions were characterized by typical myolysis; capillaries in the affected area were dilated and blocked with packed erythrocytes. Necrotic changes were localized only in those parts of the ventricular walls where the vascular bed and myoarchitecture were normally developed. In comparison with similar changes in adult specimens, inflammatory cellularization is lacking.

Animals↗

Ultrastructure of pulmonary macrophagic system.

A mature AMF, ready for phagocytosis, is a relatively large cell with an oval nucleus, with indentations of a nuclear envelope of varying depth. Evenly distributed chromatin forms beneath the nuclear envelope a rim of heterochromatin. There is a prominent nucleus with a distinct nucleolonemma. The cytoplasm is differentiated into a continuous ectoplasmic zone with numberous finger-like processes and pseudopodia. The organelles are formed by scattered round or oval mitochondria, a description is given of the Golgi apparatus in the juxtanuclear position, in certain sites multifocal in form, of the centriolar apparatus, scarce profiles of endoplasmic granular reticulum, dispersed free polyribosomes and microfilaments in varying amounts. The most outstanding feature is the rich lysosomal apparatus of varying structure depending on the functional state. Dynamics of the maturation of AMF was studied in intermediate phases, described here. The peribronchovascular connective tissue is the seat of free macrophages of a structure analogous with that of AMF. Fixed macrophages are anchored in the loose connective tissue by processes of different shape and length. The prevailing component of the cytoplasm are numerous vesicular structures and vacuoles as well as a marked lysosomal apparatus. Fixed macrophages phagocytize foreign material in situ. The septal cell exists in normal state as an element with numerous intricated processes pervading the fibrillar substrate. Numerous free polyribosomes and vacuoles are its most marked component. Activation of septal cells was demonstrated under experimental conditions. Their transformation into free macrophages is probable. In the pulmonary intersitium, in the perivascular loose connective tissue particularly free cells of a similar structure as blood monocytes were shown in normal state. Under experimental conditions an increased number of monocytes is present in pulmonary capillaries, e.g. 24 hours after an intratracheal instillation of India ink colloid solution. At the same interval a number of free cells of the monocyte structure was found in the perivascular connective tissue and also in the alveolar lumen, with phagocytized carbon. An increased number of monocytes transforming into macrophagic cells was visualized in this localization as late as 14 days after the instillation of India ink colloid solution. The experimental study with an intratracheal instillation of India ink colloid solution in the mouse gave evidence of a high readiness of AMF. The carbon particles were seen phagocytized at an interval of 5 minutes after instillation. In all intervals during which free carbon particles were present in the alveolar epithelium mature AMF were observed with no or very low phagocytic activity, their lysosomal apparatus being prominent. On the contrary, in the phagocytizing AMF, the lysosomal apparatus disappeared in the greatest part of the cytoplasm. The clearance of AMF occurs predominantly by the air route...

Animals↗