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Biomedical subjects

J Navrátil

Publications and source records attributed to J Navrátil.

At least 19 recordsLinked to original sources
PubMed1992

Fatty acids in lipids of nasoethmoidal polyps.

In 29 samples of recurrent nasoethmoidal polyps removed from 11 patients, the relative fatty acids composition was established by means of gas chromatography. Four samples of nasal mucosa of patients without polyps were subjected to the same procedure. A significant increase in the content of linoleic acid (18:2, n-6) as well as in the index "linoleic acid/oleic acid" was found. Proportion of arachidonic acid was high both in polyps and in control samples of nasal mucosa. An orientation examination of fatty acids in individual fractions of lipids, compared to serum values, showed that the main source of arachidonic acid appears to be phospholipids.

Adult↗
PubMed1991

[Disorders of the heart conduction system].

Disorders of the genesis and conduction of impulses in different parts of the cardiac conduction system are the result of functional or morphological damage of parts of the conduction system. Pathological processes which affect the cardiac conduction system are practically always comprehensive and ensue from the character of the basic disease. Previous embryological and histological investigations provide evidence of developmental and structural similarity of all portions of the cardiac conduction system. On this fact the assumption of a similar reaction of the conduction system to the acting pathological process is based. In a group of 127 patients with a positive finding, on invasive examination of the conduction system in 57 (45%) a pathological process was detected at several levels of the conduction system. This finding is consistent with experience reported in the literature and supports the justification of the term "disease of the cardiac conduction system" when there is evidence of multi-focal damage of the conduction system.

Adolescent↗
PubMed1990

Interaction of egg-white glycoproteins and their oligosaccharides with the monomer and the hexamer of chicken liver lectin. A multivalent oligosaccharide-combining site exists within the carbohydrate-recognition domain.

Binding of egg-white glycoproteins and their oligosaccharides to hexameric solubilized form of the chicken hepatic lectin and the monomeric soluble fragment containing the carbohydrate-recognition domain has been investigated by several techniques. Ligand blotting revealed significant differences in binding to two forms of the lectin only for glycoproteins bearing multiple N-linked oligosaccharide moieties in their molecule (riboflavin-binding glycoprotein, avidin or ovomucoid). Inhibition studies indicated that inhibitory potency in a series of linear and branched N-acetyl-D-glucosamine-terminated oligosaccharides is critically dependent on the number and spatial arrangement of the terminal monosaccharide residues for both forms of the lectin. Direct binding of 4-hydroxyphenyl-derivatized radioiodinated oligosaccharides measured by equilibrium dialysis and frontal affinity chromatography points to the existence of two N-acetyl-D-glucosamine-combining sites per one subunit of the lectin, as has been recently reported for the rabbit and rat liver lectin [Lee & Lee (1988) Biochem. Biophys. Res. Commun. 155, 1444-1452]. Highly branch (penta-antennary) oligosaccharides interact with more than one subunit of the hexameric form of the lectin and thus resemble the more complex interaction of the whole glycoprotein.

Animals↗
PubMed1990

Protective effect of cinnarizine against convulsive elevation of nonesterified fatty acids in CNS.

In the brain tissue there exists a highly active "pool" of nonesterified fatty acids (NEFA). The greatest part of NEFA comes from the fraction of nerve endings. It was evidenced that the model convulsive activity provoked by Bemegrid increased NEFA in the brain cortex, hypothalamus and brain stem. Cinnarizine (StugeronR) markedly decreases the convulsive increase of NEFA. The greatest inhibitory effect was observed in the brain cortex. Cinnarizine has an objective stabilizing and anticonvulsive effect on the brain tissue.

Animals↗
PubMed1990

The labilizing and stabilizing effect of physostigmine on CNS.

The authors observed biphasic changes of dopamine, norepinephrine and serotonin in the rat brain stem after a single application of physostigmine (1 mg/kg of body weight). The results confirm the hypothesis of "labilization and stabilization" of membranes.

Animals↗
PubMed1989

[Possibilities of using biophysical methods of investigation (superweak radiation of tissues) in the ORL area].

Modern biophysical methods allow an insight into the cell metabolism in healthy and in pathological states. With the help of special instruments for measurements of superweak, spontaneous metabolic radiation, we have measured the bioluminiscence of various tissue samples from the ORL region. The energy for superweak radiation is provided by the process of non-fermentative oxidation of tissue lipids, the intensity of superweak radiation is directly related to the intensity of oxidation. Superweak radiation is inherent to all the tissues of the organism but it does not show a direct relationship to the intensity of cell division. The wave lengths of superweak radiation are 360-800 nm on the visible range of the electromagnetic spectrum. We found that the intensity of radiation differs with the various types of pathological changes in tissues. On the basis of the results of our studies, we tried to determine the partical utilization of measurements of superweak radiation of tissue samples from the ORL region. The measurements will be useful to make the indication for tonsillectomy more precise and to determine the biological activity of malignomas.

Humans↗
PubMed1989

The effect of phospholipase A2 and cyclooxygenase inhibition on free fatty acids in the brain.

The levels of NEFA (oleic acid, palmitic acid, stearic acid, arachidonic acid) were studied in the brain cortex, hypothalamus and the brain stem of rat brain. Inhibition of phospholipase A2 by Delagil (Mepacrinium dichloratum CsL 3) decreased statistically significantly the values of arachidonic aci (-5.5%) in the brain cortex and the values of stearic acid (-11.2%) in the hypothalamua. The cyclooxygenase inhibition by aspirin led to a significant increase of palmitic acid (+12.7%), oleic acid (+18.7%) and arachidonic acid (+14.3%) in the hypothalamus. Total NEFA increased by 11.2%. A significant increase of palmitic acid (+26.9%), arachidonic acid (+33.9%) and of total NEFA (+22.9%) was evidenced in the brain stem. Delagil administered in combination with acetylsalicylic acid suppressed the NEFA increase observed after the application of acetylsalicylic acid alone. A statistically significant decrease was found in stearic acid (-12.6%) in the hypothalamus and in all studied NEFA in the brain stem (palmitic acid, -14.2% stearic acid -11.7%, oleic acid -3.8%, arachidonic acid -16.6% and total NEFA -11.8%).

Animals↗
PubMed1989

Mechanism of psychotropic effect of toluene.

An acute 30 min exposure to toluene vapours (0.32 mmol/l of the air) provoked in the rat brain a decrease of total nonesterified fatty acids (arachidonic acid -21.7%, oleic acid -18.3%, stearic acid -7.9% in the brain cortex and arachidonic acid -6.8% in the hypothalamus). The results are in harmony with the hypothesis of the NEFA decreasing effect of the inhibitory substances in the brain.

Animals↗
PubMed1989

Perspectives of physostigmine as antidote by toluene intoxication.

The administration of physostigmine (0.3 mg/kg s.c.) compensated toluene intoxication in rats together with NEFA return toward the normal values. This interaction of toluene and physostigmine supports the hypothesis of NEFA functioning as moderators of the cerebral activity.

Animals↗
PubMed1989

The effect of delta-9-tetrahydrocannabinol (delta-9-THC) on the release of nonesterified fatty acids in various brain structures.

There was studied the effect of repeated administration of delta-9-THC (10 mg/kg per os for two days) on the level of nonesterified fatty acids (NEFA) in the brain structures of laboratory rats. Palmitic acid, stearic acid, oleic acid and arachidonic acid were estimated with the help of gas chromatography after preliminary separation by TLC. After administration of delta-9-THC, the levels of NEFA decreased in the brain cortex, the brain stem and most in the hypothalamus. The NEFA decrease after delta-9-THC administration is in harmony with the functional inhibition of CNS, provoked by this substance.

Animals↗
PubMed1989

[Fixation of the malleus and incus].

During the past five years at the ENT Clinic in Olomouc 15 incudomallear synostoses of inflammatory aetiology were observed; 10 times tympanotomy was found, performed in patients without an inflammatory history, fixation of the malleus, or fixation of the malleus and incus or fixation of the stapes and malleus. The authors demonstrate three typical cases, incl. preoperative and postoperative audiograms. As during operation the ossicles are mobilized and left in situ et in function or removed by milling and destroyed and replaced by a reconstruction, the authors demonstrate a primarily fixed malleus found accidentally in the skull from medieval excavations, and histological preparations of primary incudomallear synostosis from a macerated skull in the anatomical museum.

Ear Diseases↗
PubMed1989

[Congenital nasal cysts and fistulae].

Congenital nasal cysts and fistulae are relatively rare. Their localization is usually medial, sometimes lateral at sites of facial junctions during the embryonic period, either above or below the nasal bones. In a group of 16 children operated in the course of 25 years on account of a congenital nasal fistula or cyst the authors encountered in two instances junction of the fistula with the dura mater. According to the histological examination dermoids or epidermoids were involved. As the pressure of the cyst may cause usuration of bone and distension of the osseous nasal skeleton, it is recommended to operate as soon as possible.

Adolescent↗