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Biomedical subjects

S Polák

Publications and source records attributed to S Polák.

At least 19 recordsLinked to original sources
PubMed2000

[Detection of silicon in a human spleen using x-ray microanalysis].

There is a lack of information on x-ray microanalysis (XMA) of the human spleen. We have examined the spleen of a patient with autoimmune thrombocytopenic purpura. The specimens were fixed in glutaraldehyde and coated by copper. The XMA was performed by a Quantum detector and a Delta-Class analyzer. In addition to spectral lines of elements normally present in human tissues, we have demonstrated silicon. The presence of silicon in human spleen may be a consequence of the organ's cleansing function.

Adolescent↗
PubMed1996

[The spleen in hereditary spherocytosis].

Hereditary spherocytosis is the most common inherent, autosomal dominant hemolytic anemia. Mild splenomegaly, venostasis and common decrease of while pulp is characteristic for hereditary spherocytosis. Cords are filled with spherocytes, sinuses can be empty or squeezed. Both sinuses and veins include ghost erythrocytes that lost haemoglobin. They are seen light-microscopically in differential interferent contrast. Macrophages are numerous, sinus lining cells are hypertrophic. Erythrophagocytosis is hardly seen by electron microscope. Not all red blood cells are spherocytes. Spherocytes are seen well in electronmicroscopy. We did not observed transition of erythrocytes through sinus walls. In certain circumstances lots of ferritin is seen both intra and extracytoplasmically. Iron accumulation in cords can result in their fibrosis.

Humans↗
PubMed1996

[Chronic autoimmune thrombocytopenia in the spleen and microparticles as seen in scanning electron microscopy].

In chronic autoimmune thrombocytopenia numerous round formations in the sinus lining cells are observed by scanning electron microscopy. They occur sometimes on the surface of erythrocytes passing through the sinus wall. It is possible that they are not cytoplasmic processes but platelet microparticles sticking on the surfaces of various cells. These particles are too small in routine counting of blood platelets in the light microscopy and probably too fragile in examining in transmission electron microscopy.

Autoimmune Diseases↗
PubMed1996

[Dermoid cyst of the spleen].

The case report of a 14-year old girl is given. In her spleen of the weight of 1580 g an irregular cyst of glossy inner surface and with striking trabeculation developed. It was filled with clear greenish liquid. The wall was formed by hyalinised collagen tissue which was covered by epidermoid and cuboidal epithelium on the inner surface. Vessel conglomerates were frequent, some bleeding or mononuclear infiltrates, foci of giant cell granulation tissue, lymphoid or fatty tissue were present.

Adolescent↗
PubMed1992

[Structural basis of appendiceal function in rabbits].

Enzymo-, immuno- and lactin-histochemical methods were used to study the structure of the rabbit appendix wall. The value of some structural components in the function of this part of the intestine is discussed. Some findings were documented electronmicroscopically. In addition to its resorptive function, the rabbit appendix is equipped with a potent defense mechanism against adverse environmental effects of the appendix content. Individual structures of this defensive barrier are closely characterized with regard to cellular equipment and possibilities of its morphological identification.

Animals↗
PubMed1991

[Gastric and duodenal polyps in acromegaly].

Relationship between acromegaly and occurrence of colonic cancer and polyps is well-known. A rare case of gastric and duodenal polyps in a patient with hypophyseal adenoma is described. After selective hypophysectomy a regression of the polyps was observed. Probable mechanisms of the development and the regression of polyposis are explained. The diagnostic value of gastroscopy in the screening for polyps in patients with acromegaly is discussed.

Acromegaly↗
PubMed1990

Premature delivery and placenta. A morphological study.

A complex morphological examination of the placentas of the prematurely delivered newborns revealed that in a part of them there was a complex of changes detectable either by a naked eye immediately after delivery or by the use of light and electron microscope, respectively. The changes observed were characteristic of premature maturation of placenta, some changes, however, were similar to those present in the placentas of the term delivered intrauterine growth retarded newborns. The most important were the following changes: underweight of placenta, placental infarctions, capillary haemangioma, increased amount of fibrinoid, small and focal circulatory defects, reduction of the microvillous border and of the pinocytic activity of the syncytiotrophoblast, focal to diffuse thickening of the basal membrane with an increased number of collagen fibrils and fibroblasts in the stroma of terminal villi. These changes resulted in deterioration of the intrauterine state of the foetus and in premature delivery of frequently intrauterine growth retarded newborn. Such changes did not occur in all placentas under study. They indicate, however, the possibility of the occurrence of chronic placental insufficiency in a part of the pregnant women treated for the imminent premature delivery. From this follows the necessity of monitoring the placental functions and the state of the foetus with a subsequent differential approach to the therapy of such patients.

Female↗
PubMed1990

[A scanning electron microscopy study of the normal rabbit appendix].

The surface relief of the mucous membrane of the normal rabbit appendix was studied under scanning electron microscopy. Two different types of surface relief were identified. One consisted of relatively regular crests and grooves of the mucosa, the other one exhibited scattered crater-like openings into which "heads of lymphatic nodes" were inserted to varying extent and which were separated from the surface mucosa by broad alveolar cavities. Since adequate terminology has not yet been coined for the description of the observed structures, the authors use the terminology of classical histology and from analogous descriptions of other reliefs.

Animals↗
PubMed1990

[Primary adenocarcinoma of the esophagus].

The presented analysis of a patient treated at the 1st Surgical Department of the Teaching Hospital in Bratislava meets the criteria for being classified as primary adenocarcinoma of the esophagus, whose characteristics are described in the paper. Primary adenocarcinomas of the esophagus occur rarely and constitute only about 0.5% of large series of esophageal malignancies. The tumor is not connected with the gastric mucosa, being separated from it by the normal mucosa of the esophagus, and it is not a metastasis. The patients suffer from late not marked dysphagia. The endoscopic and histologic findings are frequently misleading since the mucosa above the tumor is usually intact.

Adenocarcinoma↗
PubMed1990

[Structural basis of the spleen in rats].

The basic function of the spleen in the rat, similarly as in man, is to cleanse the blood of damaged old particles of the body itself, but also of foreign particles. To fulfill this function, the spleen is equipped with the white and red pulp with a specific structure of blood circulation. In an open system of circulation, blood from the arterial terminals opens into the cords of the red pulp, where it is adequately processed. From the cords the blood gets through the walls of sinuses, acting as the last filtration barrier, into the lumen of sinuses and then into the venous circulation. Unlike the human spleen, this organ in the rat has a marked marginal sinus and channel systems bridging the marginal zone. The channels mediate the circulation of lymphocytes between the red white pulp.

Animals↗
PubMed1989

[A scanning electron microscopy study of the ependyma in the lateral cerebral ventricle in humans].

The apical surface of ependymal cells in the cornu anterius of the lateral ventricle of the brain was studied in man. The surface of ependymal cells displays varied differentiation, the cells have microvilli, spherical processes, and cilia. In the cornu anterius ependymal cells without cilia as well as with one cilium and even several cilia were observed. Different types of cells occur in groups forming so-called ependymal areas, which are constituents of the lining of the ventricular walls. Ependymal areas with a large number of cilia were recorded along with areas without cilia and so-called transitory ependymal areas with a small number of cilia. There are no sharp borderlines between the individual areas.

Aged↗
PubMed1988

Gastroprotective effect of pentacaine: role of mast cells.

Pentacaine was found to prevent the development of acute haemorrhagic lesions induced by ethanol in rats in a dose-dependent way. Electron microscopy in the untreated group showed extensive disruption of the surface epithelium and deep necrosis of the mucosa after ethanol exposure. Degranulation or even complete destruction of mast cells was observed. The microvasculature exhibited several signs of derangement. After pentacaine treatment, these signs were absent and no degranulation of mucosal mast cells was observed. The mast cell-mediated effect of pentacaine appears to be only one component of its gastroprotective action.

Animals↗
PubMed1984

Rhythmic changes of human female uroepithelial squamous cells during menstrual cycle. Transmission and scanning electron microscopic study.

The cellular component of the fluid of female urethral expulsions was analysed in two healthy women (37-year-old multipara and 27-year-old nullipara) on days 1, 10, 12, 14, 26 and 27 of their menstrual cycle. Transmission and scanning electron microscopy were used to determine standard values of uroepithelial squamous cells of the fluid of female urethral expulsions on different days of the menstrual cycle. In agreement with the known changes of these cells found in cytological smears during the cycle, electron microscopy confirmed characteristic changes in the appearance of the fine cell structure and the space configuration of the squamous cells. Changes in the desmosomal junctions among squamous cells during the cycle were found. Striking adherence of bacteria and mucosubstances to the squamous cell surfaces were observed in the first half of the menstrual cycle and at the time of ovulation.

Adult↗