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Biomedical subjects

A Pataki

Publications and source records attributed to A Pataki.

30 records · Page 2Linked to original sources
PubMed1980

[The influence of aging, post-mortem delay until isolation of the tissue and duration of agony on some glycolytic enzymes in human autoptic brain tissue (author's transl)].

The influence of aging and pre- and post-mortem conditions on the activities of glycolytic enzymes and of the ATPases was determined in samples of autoptic human cerebral cortex and putamen. These results were compared with results obtained from an aging collective of rats (four groups ranging from 20 to 120 weeks of age). The results revealed an interlinked significant age-related increase in soluble hexokinase (HK) and a significant decrease in phosphofructokinase (PFK) activity in human autoptic tissue, whereas no significant age-dependent differences could be observed in rat brain. Subdivision of the cases according to duration of agony and other pre-mortem conditions revealed reduced variance and therefore statistically more significant PFK age-dependence in cases with a short agony. All other cases are not dependent on age. In addition to the pre- and post-mortem effects, the age-dependence of PFK and soluble HK can be clearly demonstrated in human autoptic brain tissue.

Adenosine Triphosphatases↗
PubMed1979

Micropreparation techniques in quantitative histochemistry - density gradient centrifugation, manual microdissection and laser microbeam preparation of tissue.

Each quantitative histochemical problem needs its specific method for tissue preparation. In this connection two of the most important preparation methods, density gradient centrifugation and microdissection of freeze-dried tissue slices, are described. Density gradient centrifugation is a very effective procedure for preparative separation of cell particles such as cell nuclei. The details of the preparation of glial and neuronal cell nuclei are described. The in vitro phosphorylation of histone in the chromatin in relation to age is given as a practical example of the quantitative histochemical application to a preparation of cell nuclei. Other techniques of tissue preparation are the manual tissue microdissection according to Lowry and the Laser microbeam preparation. Advantages and disadvantages of both methods are compared. It is shown, that the introduction of Laser microbeam dissection technique, as alternative to manual microdissection, add new dimensions to Lowry's ultramicrochemical methods. One has greater freedom in the choice of the sample size and the number of samples dissected from the same slice. Furthermore, the need for a well-trained person for the preparation is eliminated. The preparation is also considerably less time consuming and easier to perform than the manual free hand preparation. Two quantitative histochemical methods used for the investigation of microdissected tissue samples are described: the gas-chromatography-massfragmentography (GC/MS)-method for determination of transmitters and its metabolites as well as the enzymatic cycling technique of Lowry. The GC/MS-method is explained with an example of noradrenaline and dopamine determination. The enzymatic cycling technique is demonstrated in combination with the Oil-Well-Technique for determination of the NADP-cycle.

Cell Fractionation↗
PubMed1977

Enzyme histochemistry of rat folic acid nephropathy.

One hour after a single i.v. dose of 250 mg/kg folic acid, the straight portion of distal tubules in the outer medulla of rat kidneys showed a distinct reduction in succinate dehydrogenase, NADH2-diaphorase, glutamate dehydrogenase, cytochrome oxydase, Na+/K+-ATPase, and acid phosphatase activity. In contrast, the proximal tubules exhibited only a reduction in glutamate dehydrogenase and alkaline phosphatase activity. At this time the straight portion of the distal tubules, whose enzyme activity had changed, showed partly regressive epithelial changes. 24 hours after folic acid administration an even greater reduction in enzyme activity had occurred in the straight portion of distal tubules; these structures also became dilated. The adjacent collecting tubules and the corresponding proximal tubules were also severely dilated, the proximal tubules showing a loss in enzyme acitivities similar to those observed in the distal tubules. 48 hours after folic acid administration the changes largely resembled those observed after 24 hours, but were more pronounced. At this time a tubular regeneration was observed. 72 hours after folic administration extensive normalization of the histological and histochemical changes had occured. It is postulated that a disturbance of the hairpin counter-current mechanism occurs as a result of a direct, concentration-dependent effect of folic acid on the enzymes of the energy supplying metabolism. A dilation in the region of the loop of Henle and the collecting tubules occurs subsequently.

Acid Phosphatase↗
PubMed1976

The relevance of drug-induced organ pigmentation in animals.

Postmortem examination of animals from long-term safety evaluation studies often reveals pigment deposition in tissues. A review of several such observations is given and the possible chemical backgrounds of their origin are described, in an attempt to aid the determination of relevance in individual cases. It is suggested that one may be fairly broad-minded in the interpretation of the relevance of such pigments, especially if they are found only in one species, and have no influence on the function of the organs involved. A final answer comes only after administration of the particular drug to man, although he is normally dosed at all events one should not overvalue the relevance of pigmentation found in long-term animal studies.

Animals↗
PubMed1976

The automation of microspectrophotometry of tissue sections.

A system for quantitative microspectrophotometry with automatic data acquisition is described. It is relatively simple and less expensive than presently-available equipment. Fitted with the appropriate software, the system permits various types of probe selection, with both selection and measurement made under individual optimal conditions.

Computers↗
PubMed1975

Histochemical study of monoamine oxidase latency in the liver of the rat.

In a histochemical test system with adrenaline as substrate and nitroblue tetrazolium (NBT) as electron acceptor, an increase of NBT reduction in rat liver sections was found microspectrophotometrically following short hypotonic treatment. Investigations with iproniazide, a monoamine oxidase inhibitor, and non-enzymatic NBT reduction showed that the increased formazan formation was related to the presence of monoamine oxidase. It is suggested that the reason for the observed increase of formazan formation is due to increased permeability of the inner mitochondrial membrane to NBT. Consequently, the increase of monoamine oxidase observed in the histochemical test system does not represent mobilization of a latent activity, but rather complete assessment of activity that is normally present.

Animals↗
PubMed1975

[Relevance of enzyme histochemistry of rat thyroid gland].

High doses of aniline analgesics produced increased lipofuscin accumulation in rats thyroid glands after 18 week's treatment. To assess the significance of this change histochemical, biochemical and functional tests have been performed. Increased benzidineperoxidase, decreased acid phosphatase and unchanged leucyl-beta-naphtylamidase activities have been found histochemically and partly confirmed by biochemical methods. 131I-uptake was unchanged and PBI-levels decreased. The selection of appropriate histochemical methods in combination with additional techniques is stressed.

Acetaminophen↗
PubMedDate not supplied

[Occurrence of pannus in arthrosis].

Eight human femoral heads, surgically removed from patients with the clinical diagnosis: coxarthrosis or necrosis, were examined. In six of these we found severe arthrosis combined with synovitis and pannus formation. The pannus appeared as granulation tissue or fibrous connective tissue covering the surface of the cartilage or growing into it. In most cases the pannus showed a destructive appearance, although newly formed cartilage repair tissue was also observed. There was no indication for a pannus originating from the bone marrow. We therefore assume that we are dealing with a pannus of synovial origin. The possibility of a local transformation of chondrocytes into fibroblasts, is also discussed. The earlier reports concerning the occurrence of arthrosis in combination with pannus, are contradictory. We suggest that coxarthrosis can occur both with and without pannus. These two possibilities may represent different forms of arthrosis.

Femur Head Necrosis↗