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Biomedical subjects

A Veselá

Publications and source records attributed to A Veselá.

7 recordsLinked to original sources
PubMed1998

[Effect of pilocarpine in tissue structures of the anterior eye segment from the aspect of its interaction with free amino acids].

On the basis of the proofs of pilocarpine interaction with free amino acids, the mechanism of this alkaloid effect in the tissue structures of the eye anterior segment is explained. Differences of colour reactions of amino acids mixtures with pilocarpine, decrease of radioactivity of Na[I125]tyrosine mixture with pilocarpine, unsteadiness of radioactivity of Na[I125]protein A mixture with pilocarpine and rise of 16 radioactivity fractions after adding pilocarpine to Na[I125]proteins A a) show the specificity of interaction of each amino acid with pilocarpine; b) give evidence of a strong covalent bond between pilocarpine and free amino acid and give rise to new biologically active metabolite; c) show non-cholinergic pathway of pilocarpine effect; d) for ophthalmo-physiological practice it is said that with respect to the rate between pilocarpine quantity and concentration and free amino acid quantity and concentration requested therapeutical effect by lower pilocarpine dose in glaucoma disease treatment might be achieved. Thus free amino acids being reactants can be identified as mechanism by which pilocarpine becomes biologically active.

Anterior Eye Segment↗
PubMed1990

Bioaccumulation of metals from nickel smelter waste in P and F1 generation of exposed animals. Part III. Morphological responses.

Inhalation exposure experiments were conducted on a group of female adult Chinchilla rabbits placed in a field biomonitoring station located downwind from dumped nickel refinery wastes. Their F1 generation offsprings were exposed prenatally and 6 weeks postnatally. After termination of exposure, both P and F1 generation rabbits were sacrificed, their organs removed and subjected to a histologic examination using light and electron microscopy techniques. The histological responses were most marked in P generation female rabbits, namely hypertrophy of the muscle layer of pulmonary artery walls and foci of atelactasis. Electron microscopic examinations of the myocardium of chamber-exposed rats revealed evidence of muscle fibre lesions at sites of intercalary discs and changes in mitochondrial structure as a result of accumulated Ni, Cr and/or other metals. Histologically remarkable was interstitial accumulation of an unidentified electron-dense crystalloid substance situated near blood capillaries and between myofibrils and collagenous fibres; this substance is believed to be a result of metal-protein interaction. The rats injected intravenously with a suspension of metal waste displayed mitochondrial lesions analogous to those observed after inhalation exposure, but no presence of the electron-dence substance could be noted. It is concluded that chronic exposure to metal waste may give rise to cardiovascular lesions.

Animals↗
PubMed1980

[Quantitative morphologic studies on the myocardium in early stages of ontogenesis and after application of various cardioactive agents].

The authors have morphometrically studied the differentiation of the myocardium in dynamic phases of the embryonic and postnatal development in chickens and Syrian Hamsters. Moreover, they investigated the action of the beta-adrenalytic substances Practolol and Trimepranol on ultrastructure of the cardiac muscle in adult animals. The volume of mitochondria in myocardial cells in 6-day old chicken embryos amounts to 5.65% of the total cell volume, in 12-day old embryos 14.35%, in 18-day old embryos 19.60%, in 1-day old chickens 23.24% which is nearly as much as in adult animals. The volume of myofibrils in 6-day old embryos is about 3.2%, in 12-day old embryos about 7.4%, in 18-day old embryos about 16.4% and in 1-day old chickens about 21.2%. The differences between individual groups are statistically significant. The dynamics of differentiation of the myocardium in Syrian Hamsters was studied in 5 phases, namely in 14-day old embryos and in postnatal phases on the 2nd, 5th, 14th and 21st days after birth. Most cells in 14-day old embryos are rather immature. Participation of the volume of mitochondria, myofibrils, equipment of mitochondria with cristae etc. considerably increase in postnatal phases. These findings suggest that the heart of mammals is rather immature at birth and will differentiate mainly in the postnatal developmental phases. Many morphometric findings, as regards the action of beta-adrenalytic drugs on the ultrastructure of the myocardium in adult rabbits, point to the fact that application of these substances will give rise to degenerative alterations in approximately 10% of myocardial cells. Theoretical explantation of these mechanisms is being discussed.

Animals↗