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Biomedical subjects

R Pawlicki

Publications and source records attributed to R Pawlicki.

At least 19 recordsLinked to original sources
PubMed2005

Loss of interstitial cells of Cajal after pulsating electromagnetic field (PEMF) in gastrointestinal tract of the rats.

Exposure to the magnetic field has remarkably increased lately due to fast urbanization and widely available magnetic field in diagnosis and treatment. However, biological effects of the magnetic field are not well recognized. The myoelectric activity recorded from the gastrointestinal and urinary systems is generated by specialized electrically active cells called interstitial cells of Cajal (ICCs). Thus it seems rational that ICC have significant vulnerability to physical factors like an electromagnetic field. The aim of this study was to evaluate the influence of pulsating electromagnetic field (PEMF) (frequency 10 kHz, 30ms, 300 muT burst, with frequency 1Hz) on ICCs density in the rat gastrointestinal tract. Rats were divided into two groups (n=32). The first group was exposed to PEMF continuously for 1, 2, 3, and 4 weeks (n = 16), and the second group (n=16) served as a control. Tissue samples of the rat stomach, duodenum and proximal colon were fixed and paraffin embedded. The tangential sections of 5 microm thickness were stained immunohistochemically with anti-c-Kit (sc-168) antibody and visualized finally by DAB as chromogen (brown end product). C-Kit positive branched ICC-like cells were detected under the light microscope, distinguished from the c-kit-negative non-branched smooth muscle cells and from the c-kit positive but non-branched mast cells and quantitatively analyzed by MultiScan computer program. Apoptosis detection was performed with rabbit anti-Bax polyclonal antibody (Calbiochem, Germany) and LSAB 2 visualization system. The surface of c-Kit immunopositive cells decreased after exposure to PEMF in each part of the gastrointestinal tract. Reduced density of ICCs was related to exposure time. The most sensitive to PEMF were ICCs in the fundus of the stomach and in the duodenum, less sensitive were ICCs in the colon and pacemaker areas of the stomach. No marked changes in ICC density in the pyloric part of the stomach were observed. We demonstrate that the PEMF induced apoptosis dependent decrease in ICC expression.

Animals↗
PubMed1998

Blood vessels and red blood cells preserved in dinosaur bones.

Dinosaur bones, 80 million years old, were studied in the scanning electron microscope, and subjected to X-ray microanalysis. Samples for the investigations were prepared according to specially elaborated, and simultaneously described methods. Analysed were (a) the morphological structure of the blood vessels and (b) the remains of their contents. The walls of the blood vessels were found to be morphologically identical with those in present-day reptiles. Bodies were found at several places inside the vessels which strongly remind one of erythrocytes in modern bones. X-ray microanalysis of places where these bodies were accumulated revealed much higher levels of iron, than at any other regions of the blood-vessel wall. Further analysis of the "dinosaur erythrocyte" iron content could be a starting point for the possible determination of oxygen in the earth's atmosphere, 80 million years ago.

Animals↗
PubMed1997

[Electromyographic and histologic evaluation of intestinal viability].

Myoelectrical small bowel activity was measured intraoperatively with two serosal electrodes in two groups of patients. 16 patients operated electively for other indications than bowel ischaemia and 10 with small bowel ileus with symptoms of ischaemia. In later cases necrotic bowel was resected. Resected ischaemic bowel was submitted to histological examination and changes in intramural neurones were assessed. Areas of mild, moderate and severe ischaemia were compared to unchanged bowel. Both amplitude and frequency of slow waves in ischaemic bowel was markedly diminished corresponding well with changes in bowel histology. Intraoperative measurements of intestine myoelectrical activity might help a surgeon to estimate a bowel viability.

Aged↗
PubMed1997

The use of congo red as a lyotropic liquid crystal to carry stains in a model immunotargeting system--microscopic studies.

The lyotropic liquid crystal dye-Congo Red was used as a carrier in a model immunotargeting system constructed from sheep red blood cells (SRBC) representing the antigen target and rabbit IgG anti-SRBC as the specific driving immunoglobulin. Rhodamine B and Hemin stains were chosen as example chemicals carried to the target. The carried stains were introduced to the micellar organization of Congo Red by intercalation. Preserving its supramolecular organization, Congo Red binds spontaneously and selectively to antibodies that have altered structure extorted by interaction with the antigen in the immune complex. The functionality of the studied immunotargeting model was verified by fluorescence and electron microscopy. The results indicate that the supramolecular nature of protein ligands offers new ligation capabilities possibly useful for carrying stains or drugs in immune-oriented systems.

Animals↗
PubMed1995

Histochemical demonstration of DNA in osteocytes from dinosaur bones.

Osteocytes were isolated from bones of dinosaur, Tarbosaurus bataar, aged approximately 80 million years. About 10% of sections of such osteocytes revealed the presence of DNA, the latter being demonstrated histochemically using Feulgen's method and staining with ethidium bromide. An attempt was made to explain why DNA remnants could be detected only in sectioned osteocytes which all originated from bones of two (out of ten) specimens. Scanning electron micrographs showed that while in the majority of osteocytes the metaloorganic sheath developed during fossilization was damaged and porous, in some it was well preserved and intact. It is suggested that an intact cell sheath enabled the preservation of DNA, though it simultaneously prevented the penetration of reagents and dyes into the cells in unsectioned material. In osteocytes with porous sheaths, the preservation of nucleic acids until today would not be possible.

Animals↗
PubMed1994

Bis azo dye liquid crystalline micelles as possible drug carriers in immunotargeting technique.

Lyotropic liquid crystal mesophases, represented in this work by Congo Red bis azo dye solution, were proposed as systems to carry drugs to immuno-selected targets. The possible use of Congo Red for this aim arises from its liquid crystalline features, enabling it to attach to immune complexes as polymolecular, ordered conglomerates and simultaneously to incorporate many organic compounds into its mesophase, largely independent of the water with a specific but adaptive molecular organization. Molecules with planar rigid structure, and/or large hydrophobic fragments, especially those with a positively charged group in the molecule, are found to be incorporated best. Rhodamine B, Rhodamine 6G and adriamycine, which have the assumed binding features, were tested as model compounds and were found to be readily engaged into Congo Red mesophase. The effect of hydrophobicity on ligand binding was evaluated following the incorporation of homologic 10, 12, 14, 16 carbon chain organic acids and the effect of charge using small mobile tandem molecules of pI differing by a few pH units (lysine-norleucine, tyrosine-tyramine). Positive charge seems to affect binding especially by influencing the organization of molecules and the shape of the micelle simultaneously. Congo Red immobilized to heat-aggregated immunoglobulins and antibodies in the immune complex was found to retain its binding ability, confirming its possible usefulness for drug transport.

Antibodies↗
PubMed1993

Mast cells in elastic cartilage of the human epiglottis.

Light and transmission electron microscopy revealed in the elastic cartilage of the human epiglottis the presence of mast cells. Cytoplasmic granules of these cells contain characteristic cylindrical bodies, whose texture is different from that found in cytoplasmic granules of mast cells from other sites. The presence of mast cells in elastic cartilage, described for the first time, and the different substructure of their cytoplasmic granules, is considered as another proof of the heterogeneity of that cell type.

Adolescent↗
PubMed1993

Bis azo dyes--studies on the mechanism of complex formation with IgG modulated by heating or antigen binding.

The mechanism of binding of azo dyes (bis azo) to immunoglobulin G of altered conformation, induced by heating or interaction with antigen was analysed in this work. Azo dyes: Congo Red, Evans Blue and Trypan Blue were selected for these studies. The molecules of Congo Red and Evans Blue associate readily in water and exist as polymolecular micellar species of liquid crystalline organization. Such organization of molecules appeared necessary for these dyes to interact with antibodies and to affect the formation of immune complex. It was proved by studying the properties of isomeric dyes Evans Blue and Trypan Blue, whose ability to form polymolecular conglomerates in water differs, being high for Evans Blue and low for Trypan Blue. The dyes seem to influence the formation of the immune complex generally by interacting with individual immunoglobulin molecules. The rate of exchange of dye molecules in conglomerate bound to protein varies and is the lowest for the portion of molecules which are engaged directly in the complex with protein. Electron microscopic studies also confirmed the polymolecular form of the dye in the dye-protein complex. The computational simulation of dye-dye and dye-protein interaction was performed in a model system. The micelle in the system was represented by three molecules of Congo Red. The peptide loop composed of amino acids 68-88 originating from VL IgG domain, was selected to represent protein. Amino acid side chains of this fragment were reduced to C beta. The best fitness was found for peptide chains of twisted beta conformation and independently optimized conformation of the dye in a form of "twisted ribbon" micelle. It was concluded that the IgG domains become accessible for penetration of the dye after being relaxed in the result of heating or interaction with the antigen.

Agglutination Tests↗
PubMed1992

Disturbances of mineral metabolism in teeth of rats receiving corticosteroids for 3 generations.

Distribution of calcium and phosphorus was investigated with quantitative and qualitative methods in teeth of rats chronically treated with low doses of corticosteroids for 3 generations. In animals from 2nd and 3rd generation, scanning electron microscopy revealed focal lesions in enamel and dentin. The disturbances of the mineral metabolism in teeth of corticosteroid-treated rats were also reflected by abnormal calcium and phosphorus content in enamel and dentin, as assessed by X-ray microanalysis.

Adrenal Cortex Hormones↗
PubMed1991

X-ray microanalysis of fossil dinosaur bone: age differences in lead, iron, and magnesium content.

Bones of dinosaurs, Gallimimus bullatus, belonging to selected age groups, were studied using an X-ray microanalyser. The content of lead, iron, and magnesium, as well as the distribution of those elements in the investigated bone areas were determined. The results showed, that bones of old animals contained the highest level of lead and iron, whereas in young dinosaurs the respective values were lowest. The obtained data were compared with the results of X-ray microanalysis of the contemporary bone.

Aging↗
PubMed1991

Ultrastructural study of human macrophages from peritoneal dialysate.

Peritoneal macrophages obtained from 30 patients with end-stage kidney treated by intermittent peritoneal dialysis and from 30 subjects with normal renal function (relative control) were investigated by light microscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Two populations of peritoneal macrophages were distinguished in both dialysed and control patients. In the former group, the main population consisted of macrophages similar to monocytes from peripheral blood, while the majority of macrophages in control patients showed larger size, more prominent vacuolization of the cytoplasm and stronger spreading on glass surface.

Adolescent↗
PubMed1990

Peroxidase activity in peritoneal macrophages of patients with terminal renal failure treated by intermittent peritoneal dialysis.

Peroxidase activity was assessed cytochemically in macrophages from peritoneal dialysate of 50 patients with terminal renal failure treated by intermittent peritoneal dialysis. In 22 patients cells were harvested for the second time after development of peritonitis as the complication of the treatment. The obtained results were compared with those of the control group consisting of 30 patients with normal renal function. Patients treated with peritoneal dialysis showed both in complication-free period and during the course of peritonitis significantly higher peroxidase activity in macrophages as revealed by the semiquantitative score test. In the course of peritonitis, peroxidase activity in macrophages was significantly lower than in complication-free period. Electron-microscopic cytochemistry demonstrated that in macrophages obtained from both control and dialyzed patients the peroxidase activity was located exclusively in cytoplasmic granules, suggesting a similarity of the studied cells and exudative macrophages.

Adolescent↗
PubMed1990

[Deciduous teeth with fluorosis from a morphological and microanalytical point of view].

Deciduous teeth with enamel fluorosis obtained from a 7 year-old child and normal deciduous teeth were studied by light microscopy and X-ray microanalysis. In the fluorotic teeth, altered architecture of enamel prisms and marked damage of enamel were observed. X-ray microanalysis revealed disturbances in the mineral metabolism of the fluorotic tooth tissues: as compared with normal teeth, an increase in calcium, phosphorus and magnesium content as well as lowered calcium/phosphorus ratio were found in the enamel prisms, interprismatic substance, dentinal tubules and intertubular dentin.

Child↗
PubMed1989

[Hyperplasia of gingivae in the course of incomplete form of Melkersson-Rosenthal syndrome].

A case of incomplete Melkersson-Rosenthal (s. M-R) syndrome manifesting itself by the lower lip and cheeks' mucous membrane oedema and hyperplasia of gingivae has been described. Histopathological examination of the cheeks has demonstrated disseminated, perivascular inflammatory infiltrations of sarcoid type, whereas massive infiltration composed nearly exclusively of plasmatic cell has dominated in segments of gingivae. Electron microscopic examination has demonstrated increased migration of the cells resembling lymphocytes through the epithelium towards the surface and progressive morphological changes leading to the disintegration both lymphocytar cells and plasmatic ones and symptoms of interstitium fibrotic processes.

Cell Movement↗
PubMed1988

Structural and microanalytical changes in dentition after radiotherapy applied in cases of tumour in the oral cavity region.

Morphological observations by means of the scanning electron and optical microscopes as well as microanalytical qualitative and quantitative tests concerning content and distribution of calcium, phosphorus and magnesium in the teeth being in irradiation field were made in patients treated for larynx cancer by methods of radiotherapy. The teeth enamel was in some places thinner and in some others it was lacking. The characteristic defects took place in the form of notches, cracks and of superficial destruction. In X-ray microanalyser the enamel showed some features of demineralization. In dentine, features of demineralization and on the other hand features of remineralization were seen. The root dentin, in which destructive processes but also reparation processes developed by root cement could be seen, was rather characteristic. Clear structural changes and disturbances of mineralization in hard tooth tissues being under therapeutic X-ray irradiation were observed.

Adult↗
PubMed1987

Human placental trophoblast in regions of high and low environmental pollution. A histochemical and morphological study.

The authors demonstrate the dependence of development of a uniform layer of syncytiotrophoblast with good cytochrome oxidase activity in placental villi on the absence of noxious industrial by-products in the environment of the pregnant woman. The degree of deviation from the developmental norm observed in regions free from industrial pollution can serve as measure of the degree of that pollution in urban-industrial regions.

Electron Transport Complex IV↗