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Biomedical subjects

L Malinovsky

Publications and source records attributed to L Malinovsky.

At least 19 recordsLinked to original sources
PubMed1999

Thymectomy and multiple sclerosis: ultrastructural study of an experimental model.

Transmission electron microscopy was performed on specimens of the thymus of rats induced for acute experimental allergic encephalomyelitis (EAE). The ultrastructural alterations of the thymus were progressive and correlated with EAE development. The thymic disorganization was due to a progressive degeneration of both epithelial cells and thymocytes. These data suggest a direct involvement of the epithelial thymic cells and thymocytes in EAE pathogenesis and may suggest the intriguing therapeutic concept of thymectomy in the management of multiple sclerosis.

Animals↗
PubMed1999

The Chievitz juxtaparotid organ.

The Chievitz juxtaparotid organ represents a macroscopic longitudinal formation, which is developed from oral cavity ectoderm in its lateral wall. As to its function, the organ probably represents a mechanosensor with different qualities of perception. The information coming from its sensors takes part in different activities of the lateral wall of oral cavity during sucking, swallowing, mastication, speech, protecting reflexes and wall tonus. The Chievitz juxtaparotid organ is not only a morphologically interesting structure, but is of great importance also for clinic and surgical pathology of the oral cavity.

Cheek↗
PubMed1998

Nerve fibers--mast cells correlation in the rat parietal pleura.

Our results show that a morphological correlation exists between catecholaminergic nerve fibers and mast cells in the rat parietal pleura. Mast cells are found in proximity to catecholaminergic nerve fibers. Moreover we have demonstrated that mast cells and nerve fibers in the perivascular areas of rat parietal pleura show the same formaldehyde fluorescence. In rats previously sympathectomized with neurotoxin 6-OHDA the nerve fibers appear disarranged and poorly fluorescent and related mast cells show a low fluorescence. The importance of this correlation and the possible role of mast cells are discussed.

Animals↗
PubMed1998

Venous drainage of the stomach in the golden hamster (Mesocricetus auratus) and the guinea pig (Cavia aperea f. porcellus).

Venous drainage patterns of the stomach were studied in 30 golden hamsters (Mesocricetus auratus) and in 30 guinea pigs (Cavia aperea f. porcellus). In golden hamsters the most frequent group had a v. gastroepiploica dextra (85.6% of cases). The v. gastroepiploica sinistra was found in 63.3% of cases. In the second group, the venous drainage pattern was without a v. gastroepiploica dextra (13.3% of cases). The only constant venous channel from the stomach was the v. gastrica sinistra. Other veins draining the stomach were vv. gastricae (tributaries of the v. lienalis) and interorgan venous anastomoses with neighbouring organs. A venous arch along the curvatura ventriculi major was not observed in any of the cases. In the guinea pig, the first group with a v. gastroepiploica dextra accounted for 90.0% of cases while the second group without this vein represented 10.0% of cases. The only constant venous channel was, once again, the v. gastrica sinistra. Other veins of the stomach were similar to those in the golden hamster. A venous arch along the curvatura ventriculi major was found in 76.6% of cases. Some differences in the venous pattern between the two animal species can be explained by zoological differences in these mammals. The results obtained also stimulate interest in the study of possible variations in venous patterns of the stomach in man.

Animals↗
PubMed1998

Venous drainage of the stomach in the domestic rabbit (Oryctolagus cuniculus f. domestica, breed large Chinchilla) and the domestic cat (Felis catus L. f. domestica).

Two basic patterns of venous drainage of the stomach were found in rabbits. In the first, which is highly prevalent (27 cases-90.0%), the v. gastroepiploica dextra is present while no such vein is present in the second one. Other venous channels are represented by the v. gastrica sinistra and by tributaries of the v. lienalis. In cats there are also two basic patterns of the stomach venous drainage. The first highly prevalent type without the v. gastroepiploica dextra was found in 23 cases (76.0%); in the second type this vein was present. In rabbits the v. gastroepiploica sinistra was observed in 25 cases (82.5%), in cats in only two cases (6.6%). The v. gastroepiploica dextra in the rabbit is usually a tributary of the v. portae, while in cats it is a tributary of the v. lienalis. In ten rabbits (33.3%) there was a venous arch around the curvatura ventriculi major, while in cats it was absent. The great difference in the stomach venous pattern in rabbits and cats can be explained by the different zoological position of these two kinds of animals.

Animals↗
PubMed1997

Venous drainage of the stomach in the laboratory mouse (Mus musculus v. alba) and the laboratory rat (Rattus norvegicus v. alba).

The authors studied the venous drainage pattern of the stomach in 30 adult laboratory mice (Mus musculus v. alba) and in 31 adult laboratory rats (Rattus norvegicus v. alba) of both sexes. In mice, two basic patterns of the venous drainage of the stomach have been found, the first one (50.0% of cases) with a vena gastroepiploica dextra, while in the second pattern (50.0% of cases) the vena gastroepiploica dextra is absent and the venous blood from the curvatura major ventriculi and fundus ventriculi is drained only via the v. lienalis. In rats, three basic patterns of venous drainage of the stomach were found, the first group (35.2%) with the v. gastroepiploica dextra, the second group (38.4%) with prevalence of the v. gastrica sinistra and the third group with various tributaries of the v. lienalis from the stomach (25.6%). The vena gastrica sinistra is the only constant venous channel in both animals examined. Between interorganic venous anastomoses in the mouse and the rat no great differences exist. In spite of the great variability of veins the results indicate that it is possible to differentiate some basic patterns of the venous drainage of the stomach in the animals studied.

Animals↗
PubMed1997

Evidence of a kallikrein inhibitor in human kidney. A new ring of the kallikrein-renin-angiotensin-aldosterone chain.

By means of immunohistochemical reactions, the authors proved the inhibitor II-related immunoreactivity in distal convoluted tubules of human kidney. A sharp inhibitor II-related immunoreactivity was also present in the blood vessels' wall. On the contrary, in the wall of proximal tubules and glomeruli only low reactivity was found. The demonstration of an inhibitor II-related immunoreactivity in the distal convoluted tubules and vessels of human kidney represents a strong evidence that an inhibitor of kallikrein exists and acts also in humans as an important key in the kallikrein-renin-angiotensin-aldosterone chain and hitherto confirms the experimental data of the literature. The proved inhibitor in the human kidney may intervene in the modulation of the kallikrein-kinin system and thus represents a key role in the intrarenal mechanisms related to the blood flow and arterial pressure regulation.

Blood Pressure↗
PubMed1997

[An explanation of the mechanism of attacks of atrial fibrillation in individuals without detectable heart disease].

The authors investigated 10 men aged 30 to 60 years who developed repeatedly attacks of atrial fibrillation. In all patients previous alcohol consumption was recorded in the case-history. In none of the patients organic heart disease was detected. In previous experiments the authors induced by alcohol administration to rats in the tracheal cells and paratracheal myelinated nerves an increased occurrence of lamellar bodies which is consistent with data in the literature which confirmed the presence of lamellar bodies in the human heart muscle in idiopathic cardiomyopathy. The authors assume therefore that alcohol induced increased presence of lamellar bodies in the myocardium which are formed during dystrophic changes, in particular from mitochondria, can lead due to reduced energy release to impaired conduction of excitation in the myocardium. This condition may be enhanced also by impaired calcium metabolism in alcoholic dystrophy.

Adult↗
PubMed1997

Angiomegaly.

The authors report a clinical and ultrastructural study on a group of patients with angiomegaly, a vascular disorder characterized by elongated and distended blood vessels affecting the arterial (arteriomegaly) and/or venous system (venomegaly). The arterial group, drawn from a large arteriographic series, focuses on a comparison between atherosclerotic arteriopathy and arteriomegaly. The venous group, drawn from a large ultrasound series of vein disorders, is made up of patients with venomegaly. Venomegaly gives rise to few or no symptoms and it appears to be less frequent than arteriomegaly but as the latter proved to be associated in the majority of cases studied. Based on ultrastructural findings, the chief abnormality of angiomegaly seems to lie in a specific alteration of the elastic component of the vessel wall. We found slightly osmiophil amorphous elastic material neighbouring the basement membrane of the myocytes of the vessel walls. In the superficial parts of these myocytes occurred a great number of pinocytotic vesicles indicating for a rich creation of the new elastic material. Middle or highly osmiophil thick elastic fibers with irregular side protrusions were also found among myocytes remembering the moth-eaten picture. Results from a large ultrasonographic study on patients' relatives suggest an inheritability of this vascular disorder.

Aged↗
PubMed1997

The immunolocalization of PGP 9.5 in normal human kidney and renal cell carcinoma.

The Authors studied the localization of protein gene product (PGP) 9.5-like immunoreactivity in normal human kidney tissue and compared the results with the same immunostaining in renal cell carcinoma. PGP 9.5-like immunoreactivity was found in cells of distal convoluted tubules and in some glomerular capillaries. The cells of proximal convoluted tubules did not show any immunostaining. Sections from renal cell carcinoma showed a very low immunostaining or were negative for PGP 9.5. As PGP 9.5 is a marker of the diffuse endocrine system, the Authors believe that the stained cells of distal tubules should be considered as neuroendocrine cells. The negative reaction to PGP 9.5 antibodies in renal cell carcinoma is rather surprising since not only tumours of neuroectodermal origin, but also tumours of other origin and tissues from some chronic degenerative diseases show a positive reaction. The explication of a negative reaction in renal cell carcinoma remains open: one of the possible explanations could be the specific histogenesis of this tumour.

Carcinoma, Renal Cell↗
PubMed1997

Vascular anastomoses among abdominal organs in laboratory animals.

Vascular anastomoses among abdominal organs were studied in 289 laboratory mammals. Arterial anastomoses joining the wall or the parenchyma of the abdominal organs were studied in 108 animals and were found among the stomach, the spleen and the pancreas. In the cat, such anastomoses occur in 86.7% of cases, in the guinea pig in 73.3%, in the hedgehog in 61.1%, in the rabbit in 3.3%. The highest mean value was found in the cat: 3.1 anastomoses. Venous anastomoses were studied in 181 animals and were found among the stomach, the spleen and the pancreas, too. With the exception of the guinea pig (found in 89.1% of cases), these anastomoses were found almost in all cases of other five examined species. They mostly occur between the stomach and the spleen, and between the spleen and the pancreas with some differences in the guinea pig and the cat. The highest mean value was found in the rat: 6.1 anastomoses. For the present, it is not possible to state any significant differences among orders and species examined. As these vascular anastomoses occur also in man, we believe that they should be preserved during surgical procedures.

Animals↗
PubMed1995

Immunohistochemical localization of laminin and type IV collagen in human cutaneous sensory nerve formations.

We used immunohistochemical techniques and monoclonal antibodies to localize two basement membrane components (laminin and type IV collagen) in the nerves and sensory nerve formations, or corpuscles, supplying human digital skin. Furthermore, neurofilament proteins, S-100 protein and epithelial membrane antigen were studied in parallel. In dermal nerve trunks, immunostaining for laminin and type IV collagen was found to be co-localized in the perineurium and the Schwann cells, the stronger immunoreactivity being at the external surface of the cells. In the Meissner digital corpuscles, the immunoreactivity for laminin and type IV collagen was mainly observed underlying the cell surface of lamellar cells, while the cytoplasm was weakly immunolabelled or unlabelled. Finally, within Pacinian corpuscles co-localization of the two basement membrane molecules was encountered in the inner core, intermediate layer, outer core and capsule. Laminin and type IV collagen immunoreactivities were also found in blood vessels and sweat glands, apparently labelling basement membrane structures. The present results provide evidence for the presence of basement membrane in all periaxonic cells forming human cutaneous sensory nerve formations, and suggest that all of them are able to synthesize and release some basement membrane components, such as laminin and type IV collagen. The possible role of laminin in sensory nerve formations is discussed.

Adolescent↗
PubMed1995

Ultrastructure of lamellar complexes in glomerular Krause spherical corpuscles.

The authors compared the ultrastructure of lamellar complexes in the penis skin of the green monkey and in the woman's clitoris skin. In the green monkey the lamellar complexes consist of a maximum of 5 lamellae of Schwann cells, their greatest width is about 4.5 microm. The interlamellar spaces are filled with fine filamentous material. In the woman the lamellar complexes consist of a maximum of 7 lamellae, the interlamellar spaces are narrower than in the first case and filled with collagenous fibrils. Their maximum width is about 6.5 microm. The findings thus support the view that the lamellar complexes of glomerular corpuscles are morphologically and functionally similar to other simple lamellar corpuscles. The glomerular corpuscles contain also some non myelinated thin nerve fibers. Therefore for these corpuscles an additional (unclear) function can be considered.

Animals↗
PubMed1994

Immunohistochemical localization of calcium-binding proteins in the human cutaneous sensory corpuscles.

The localization of the calcium-binding proteins (CaBP) calbindin-D28k (CB), parvalbumin (PV) and S-100 protein (S100P) in the human cutaneous sensory corpuscles was studied by immunohistochemical procedure using monoclonal antibodies. Occurrence of CB, PV and S100P immunoreactivity (IR) was observed in the lamellar cells of Meissner's corpuscles. In the pacinian corpuscles, S100P IR was restricted to the inner-core cells whereas CB and PV IR were found labelling the axon, inner core, outer core and capsule. At the light-microscope level of resolution, the presence of IR in the axon of Meissner's corpuscles cannot be ensured. Since calcium ions (Ca2+) seem to participate in the mechanoreceptor electrogenesis, present results suggest that CaBP could be involved in buffering and/or transport of Ca2+ within the specialized cells surrounding the axon tips of sensory corpuscles, thus, maintaining the periaxonal microenvironment.

Adult↗