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Biomedical subjects

J Kotz

Publications and source records attributed to J Kotz.

At least 19 recordsLinked to original sources
PubMed1997

Polyelectrolyte Complex Formation in Lamellar Liquid Crystalline Systems

The influence of polyelectrolytes on structure formation in liquid crystalline Na-dodecylsulfate/decanol/water systems was investigated by means of small angle X-ray diffraction, rheology, NMR spectroscopy, and microscopy. By adding Na-polyacrylate (PAA) into the mesophase, the one-phase region is left and phenomena of phase separation into a solvent-rich and a polymer/surfactant-rich phase occurs. By incorporating an anionic and cationic polyelectrolyte step by step the tendency of phase separation is increased drastically. The self-organization process can be regulated directly by varying the water content of the system. However, at a water content of 30% the properties of the resulting liquid crystal were changed drastically. X-ray diffraction shows a multitude of Bragg peaks, NMR shows a peak-splitting, and rheology shows a change from non-Newtonian to Newtonian-flow behavior. On the basis of the experimental results an ordered multilayer associate structure can be assumed.

Journal Article↗
PubMed1992

Studies on effect of pesticide Chlorfenwinfos on mouse immune system.

The effect of organophosphate pesticide--Chlorfenwinfos on the selected parameters of humoral and cellular immunologic response in mice was investigated. Hematologic and histologic examinations were run parallelly. The animals were treated with pesticide p.o. during 90 days in doses 1/100, 1/50 and 1/25 of LD50. It was found that Chlorfenwinfos exerts immunotropic effect. After high doses the strong suppressive effect in PFC and EA rosettes was observed. Significant involution of thymus was noted. Il-1 activity, DTH reaction (24 h after challenge) and endogenous and exogenous spleen colonies were stimulated. It seems that immunotropic effect of this pesticide is reversible. Three weeks after the exposure to this compound had been stopped, PFC, IgG and IgM level came back to the normal value.

Animals↗
PubMed1989

[Morphologic studies of the reaction of the subcutaneous connective tissue in rats to implantation of porous ceramics].

In the authors carried out testing of the porous ceramics Al2O3 biocompatibility. Comminuted ceramics with an average graining 3.5 were inserted subcutaneously in suspension of physiological salt in rats. The animals were killed after 7, 15, 30, 60 and 180 days. Histologic testing of the skin together with the subcutis in the place of the ceramics' powder injection as well as testing of the internal organs was carried out. It was observed that already after 30 days the connective tissue reaction became stable and did not change until the end of the experiment. A connective tissular capsule 120-160 mu depth of collagenous fibre and some fibroblasts of the correct structure came into existence around the inserted ceramics' powder. In the course of the whole experiment neither macrophages nor great foreign bodies were observed. Accumulation of the ceramics' molecules and RES reactions were not observed in the internal organs. The tested ceramics in characterized by high tissular biocompatibility.

Adaptation, Physiological↗
PubMed1988

Application of porous bioceramic in experimental therapy of bone injuries. I. Morphological and histochemical studies in the control animals.

The process of healing of the rabbits' bone tissue after mechanical injury was studied. The femoral bone was injured by means of oscillating saw. The animals were killed 3, 6, 9, 14, 18 and 30 days after operation and the callus with the surrounding periosteum was taken for morphological examination. Besides, acid mucopolysaccharides level and aminopeptidase activity in the callus (up to the 18th day of healing) were determined. The time of total bone union was established for 30 days.

Aminopeptidases↗
PubMed1988

Application of porous bioceramic in experimental therapy of bone injuries. III. Dynamics of the callus development at the site of porous bioceramic implantation. Morphological, histochemical and histoenzymological studies.

In this work the biocompatibility of porous bioceramic implanted to the rabbit femoral bone was studied. The animals were killed 3, 6, 9, 14, 18 and 30 days after implantation and the callus with surrounding periosteum from the site of implant was taken for the studies. Morphological investigations of the callus were carried out up to the 30th day of healing of the bone tissue. Moreover, acid mucopolysaccharides level and activity of enzymes (acid and alkaline phosphatase, aminopeptidase, non-specific alpha-esterase, adenosine triphosphatase and succinate dehydrogenase) were studied up to the 18 day of the callus development. The results show that after bioceramic implantation, morphology of particular stages of the callus development, behaviour of acid mucopolysaccharides as well as localization and activity of enzymes are the same as in the normal healing process of the injured bone tissue. After 30 days total union of the mature bone tissue with bioceramic was established. We conclude that porous bioceramic satisfies the requirements for biomedical materials and may be safely used in the treatment of certain bone system diseases in humans.

Alkaline Phosphatase↗
PubMed1983

Morphological and biochemical studies on experimental allergic encephalomyelitis in inbred lines of chickens.

An attempt to establish the relation between morphological and biochemical indices determining the inflammatory state in brain after induction of allergic encephalomyelitis in chickens was taken up. Symptoms of encephalomyelitis were accompanied by the changes within T and B lymphocyte population and by distinct increase of activity of trypsin inhibitor and content of sialic acid in blood serum.

Animals↗
PubMed1983

Morphological changes in organs of mice induced by the combination of adriamycin and pustulan.

In CDF1 mice treated with the combination of pustulan (50 mg/kg) and a low dose of adriamycin (10 mg/kg), the profound changes were noted in the liver. They included both destructive lesions in hepatocytes and the proliferation of the RES. Similar morphological changes, though generally less pronounced, were observed in mice treated with a high dose of adriamycin (20 mg/kg). The myocardial lesions were found in mice treated with the high dose of adriamycin or the combination of pustulan with the low dose of adriamycin. Morphological changes in the myocardium, as opposed to those in the liver were not reversible. No considerable changes were seen in organs of mice treated with pustulan at a dose of 50 mg/kg.

Animals↗