T. Cichocki

Output of Peritoneal Cells into Peritoneal Dialysate

The quantitative and qualitative characteristics of cells in the peritoneal dialysate from 12 patients were examined. The number of cells in each subsequent fraction of dialysate decreased, while the

Calcification of aortic wall in cholesterol-fed rabbits

Development of the mineralization process in the course of atherogenesis was studied using the cholesterol-fed rabbit model. The aorta samples were investigated by means of proton and electron microprobes, infrared spectroscopy and X-ray diffraction as well as selected histochemical staining. Blood serum was analysed every 2 weeks to determine the content of cholesterol, triglycerides, inorganic phosphorus, ionized calcium, elemental composition as well as activity of alkaline phosphatase. It was found that the administered diet did not disturb the calcium and phosphorus homeostasis. Histochemical findings confirmed the formation of lipid-rich lesions blocking the lumen of the vessel. The dystrophic calcification was observed only in the atheroma, while in the tunica media a slight mineralization similar to that found in controls was observed after 210 days of the diet. In the atheroma the only phase detected was a defective hydroxyapatite. The perfection of the crystals, as well as the diameter of the deposits, increased during the course of the diet reaching about 2 microns after 210 days. The crystals were not contaminated with carbonate groups regardless of the duration of the diet.

Elemental composition of the human atherosclerotic artery wall.

SummaryThe elemental composition of the human atheroselerotic popliteal artery was examined using the proton-induced X-ray-emission (PIXE) method. The application of a narrow proton beam (3×10 μm2) enabled us to determine not only the concentrations of Cl, K, Ca, Fe, Cu, Zn, Br and Pb, but also their localization in different artery-wall regions. The highest mean concentrations of Cl, K, Zn and Br were found in the tunica media. In the investigated sections the distribution of Ca and Fe varied: sometimes, these elements were prevalent in the tunica intima, whereas in other cases, the highest concentrations were observed in the tunica media or tunica adventitia. The concentration profiles of each element were characterized by many sharp, narrow peaks. The highest concentrations of Ca and Fe showed such high levels that only one explanation is possible, i.e. the presence of crystals. The correlation of Ca peaks with those of Zn and Fe is discussed. The usefulness of the micro-PIXE method for the investigation of biomedical materials is also considered.

Some Aspects of Cellular Immunity in Untreated and Maintenance Hemodialysis Patients

The cellular pattern of skin exudate in untreated uremic patients differed from that in healthy persons. The skin exudate composition in patients on maintenance hemodialysis approached normal values. Such normalization was, however, static: after sensitization with dinitrochlorobenzene--contrary to the control--both treated and untreated patients exhibited no changes in the cellular pattern of exudate. The activity of acid phosphatase in the cells of exudate was highly positive in control, almost normal in dialyzed, but weak in untreated uremic patients. Our investigations confirmed that cellular immunity in untreated and in maintenance hemodialysis patients is suppressed.

Proton microbeam study of calcium-phosphate complexes in human arteries

Abstract The proton microprobe was used for the determination of the elemental composition of Ca-P deposits in 3 types of human arteries (abdominal aorta, coronary artery, circle of Willis). The techniques used for the elemental analyses were PIXE and RBS. The distribution of concentrations of C, N, O, P, S, Cl, K, Ca, Fe, Cu, Zn, Br, Sr and Pb were measured. The chemical structure of the Ca-P deposits as well as the role of certain elements in the calcification process were considered. A comparison between different investigated arteries was also made.

The analysis of mineral deposits and proteoglycans content in the cartilage of mouse trachea using PIXE in combination with proton microprobe

The tracheal cartilage of mature mice have been investigated using PIXE (proton induced X-ray emission) in combination with a proton microprobe on snap frozen cryosectioned material. The localization and quantitative measurements of P, S, Cl, K, Ca, Fe, and Zn concentrations as well as direct and indirect assessment of glycosaminoglycans by measurement of S content and measurement of bound colloidal iron at pH = 1.8 has been performed. Adjacent sections were stained with the Hale method in Müller modifications and the v. Koss method for sulphated mucins and inorganic deposits respectively. It has been found that hyaline cartilage in trachea contains mineral deposits and that P + Ca amounts up to 22% of cartilage dry mass. The Ca/P ratio approaches 2 what indicates hydroxyapatite type crystals. The cartilage contains substantial amounts of S reflecting the presence of sulphate groups. It was found that the cartilage binds also colloidal iron at low pH. There is a good correlation between places with high amount of bound colloidal iron assessed by PIXE and places showing strong Prussian Blue staining. The Fe/S ratio was, however, much lower in the cartilage than in other tissues what indicates that the colloidal iron method does not give quantitative results. There were no regions showing substantial decrease in Fe/S ratio which we found previously as typical for degenerating and calcifying growth plate cartilage. This may be connected with a relatively low degree of calcification degree of the tracheal cartilage.

Measurement of colloidal iron binding at low pH in cartilage using the proton microprobe

SummaryQuantitative micro-PIXE analysis was performed on mouse embryo epiphyseal cartilage and on the rib cartilage of mature animals after incubation of sections with colloidal iron at pH 1.8. The iron content as well as that of sulphur and phosphorus and Fe/S, Fe/P ratios were determined. It was found that colloidal iron content was higher in the cartilage than in other tissues. The cartilage also displayed the highest content of sulphur. The Fe/S ratio was however not constant, being highest in the degeneration zone close to the mineralization front, where the binding of iron was strongest while the amount of sulphur decreased. This indicates that factors other than number of sulphate groups influence the binding of positively charged molecules to glycosaminoglycans. This is confirmed by differences in the results obtained for embryonic and mature rib cartilage.

Dialysis for psoriasis —Preliminary remarks concerning mode of action

SummaryIn one patient treated by peritoneal dialysis for psoriasis the skin lesions cleared completely. In two persons hemodialysis gave unsatisfactory results.In treated and another three untreated patients cellular immunity was evidently suppressed. This phenomenon is similar to the immunologic changes in persons with uremia.Solutes in middle molecular weight range (SMMWR) suppress cellular immunity. These compounds were therefore investigated in psoriatics. The level of SMMWR was lower before than after each dialysis, although their concentration increased slightly during the dialytic treatment.This suggests that solutes in middle molecular weight are fixed in the epidermis and/or in the walls of the skin capillaries and that dialysis liberates them from these places.Peritoneal dialysis seems to be a more effective method of treating psoriasis than hemodialysis. Solutes in middle molecular weight range might play an important role in the pathomechanisms of this multifactorial disease.ZusammenfassungBei einem Patienten, der mit der peritonealen Dialyse behandelt wurde, heilten die psoriatischen Herde völlig ab. Bei zwei weiteren Patienten waren die Resultate nicht befriedigend. Bei den behandelten und den drei nicht behandelten Patienten war die celluläre Immunität augenscheinlich unterdrückt. Dieses Phänomen ist mit den immunologischen Veränderungen bei Personen mit einer Urämie zu vergleichen. Organische Verbindungen von mittlerem Molekulargewicht, wozu auch die Gruppe der urämischen Toxine gehört, unterdrücken die celluläre Immunität. Deshalb wurden diese Verbindungen bei Psoriatikern untersucht. Der Spiegel der SMMWR war vor jeder Dialyse tiefer als danach, obwohl deren Konzentration während der Dialysebehandlung leicht anstieg. Dies läßt vermuten, daß diese SMMWR-Substanzen in der Epidermis fixiert sind oder im Bereiche der Capillaren vorliegen und dementsprechend während der Dialyse von diesen Orten freigesetzt werden.Die Peritonealdialyse scheint mehr eine wirksamere Behandlungsmethode der Psoriasis zu sein als die Hämodialyse. SMMWR-Substanzen können eine wichtige Rolle in dem Pathomechanismus der multifaktoriellen Erkrankung darstellen.

Experimental comparison of micro-PIXE with other methods utilized for biomineralization studies

Abstract The present study deals with the investigation of arterial wall mineralization i.e. of inorganic compound development within artery wall under normal or pathologic conditions. Autopsy samples of human aorta as well as fragments of aorta obtained from hypercholesterolemic rabbits were used for the experiments. The samples were investigated using micro-PIXE, PIXE and PIGE techniques, infrared and Raman spectroscopy, X-ray powder diffraction and a variety of histochemical methods in order to compare the techniques based on a proton microprobe with the other methods which aimed at the investigation of inorganic deposits. Proton microprobe measurements confirm the different composition of mineral deposits found in rabbit and human aorta samples. In the case of animal aorta the apatite crystals constitute the mineral form of deposits while for human samples we deal with a mixture of different compounds. Moreover, for rabbit aorta samples the deposits were found always in the atheromas, while in human aorta sections the mineral deposits were localized in the media of the aortic wall. The proton microprobe can be considered to be a valuable addition to the experimental methods that have been applied in the study of the biomineralization process. It permits a qualitative determination of mineral deposits in situ while infrared and Raman spectroscopy as well as X-ray powder diffraction measurements may be performed only for ashed aorta samples. The possibility of in situ measurements and high detection sensitivity seem to be the most significant advantages of a proton microprobe in the study of artery wall mineralization.

Intramembranaceous ossification analyses by a proton microprobe.

SummaryThe proton induced X-ray emission method in combination with a proton microprobe was applied to study the intramembranaceous ossification. As material sections of mouse embryo skulls from the 17th and 19th day of gestation were used. The morphology of the sample was examined by routine histochemical procedure performed on the sections adjacent to that irradiated by the proton microprobe. The measurements were made in line scan and raster scan mode. The concentrations of P, S, Cl, K, Ca, Fe and Zn were determined at each irradiated point. The average element concentrations were calculated for four parts of each section (bone, cartilage, mesenchymal tissue close to the bone and mesenchymal tissue in other places). The distributions of Ca and P (less markedly than Ca) concentrations almost exclusively correlate with localization of the bone while S, Cl and K concentrations show preference to the cartilage. The amount of inorganic material in flat bones of the 17-day embryo amounts to 14% of the dry mass. The material is characterized by a Ca/P ratio of bout 1.6 In the embryo 2 days older the amount of the inorganic phase is practically the same (15%) while the Ca/P ratio approaches 2. This suggests the presence of the precursor phase in the flat bone calcification. It is possible that octacalcium phosphate (Ca/P ratio equals to 1.72) is formed at the onset of the flat bone mineralization which transforms rapidly (in 2 days) to a more stable mineral (defective hydroxyapatite).