Piotr Kuropka

Homologous Lactoferrin Triggers Mobilization of the Myelocytic Lineage of Bone Marrow in Experimental Mice

The effects of lactoferrin (LF), an iron binding protein, on myelopoiesis have been studied extensively in vitro and in vivo in human and murine models over the past three decades. Due to the lack of high-quality homologous LFs, however, the conclusions are still unequivocal. Recently, both human and murine LFs have become available as recombinant products expressed in Chinese hamster ovary (CHO) cell lines showing mammalian type of glycosylation, thus apparently species compatible. In this study, we present the effects of homologous recombinant mouse LF (rmLF) on myelopoiesis in CBA mice. The myelocytic lineage has been assessed by their appearance in circulating blood and bone marrow, and induction of relevant mediators of inflammation. Intravenous injection of rmLF (100 μg/mouse) resulted in a significantly increased number of myelocytic cells in the circulating blood after 24 h. Mouse serum transferrin, used as a control protein, showed no stimulatory effect. The increase in output of neutrophil precursors, neutrophils, and eosinophils was correlated with a twofold increase of leukocyte concentrations. The analysis of the bone marrow sections confirmed increased myelopoiesis. The alterations in the bone marrow cell composition were statistically significant regarding mature neutrophils (10.8% vs. 27.7%), metamyelocytes (11.4% vs. 16.0%), and myelocytes (2.4% vs. 4.0%). The mobilization of the myelocytic cells in the bone marrow and the increased output of these cells into circulation were accompanied by elevated serum concentrations of interleukin-6 at 6 h and haptoglobin at 24 h following administration of rmLF. In conclusion, the homologous LF elicits significant and transient myelopoiesis in experimental mice.

Topically applied azaphenothiazines inhibit experimental psoriasis in mice

ABSTRACT The therapeutic efficacy of topically applied azaphenothiazine derivatives: 9‐chloro‐6‐acetylaminobutylquinobenzo[3,2‐b][1,4]thiazine (compound 4) and 6‐chloroethylureidoethyldiquino[3,2‐b;2′;3′‐e][1,4]thiazine (compound 5) in the amelioration of inflammatory symptoms of imiquimod‐induced psoriasis in mice was investigated. Clobederm®, containing clobetasol propioniate, served as a reference drug. The application of the compounds led to thinning of the epidermis and reduction of the cell layers. The suppressive actions of the compounds were even stronger with regard to pathological changes of the dermis. The compounds also exerted generalized, anti‐inflammatory effects by decreasing the number of circulating leukocytes, lowering subiliac lymph node weight and partially normalizing an altered blood cell composition. The changes in the composition of main cell types in the epidermis and dermis were less affected by the compounds. In addition, both compounds inhibited to a similar degree production of tumor necrosis factor &agr; (TNF &agr;) in human whole blood cell culture. Whereas compound 5 strongly inhibited IL‐8 and CXCL10 chemokines in human keratinocytes – KERTr cell line, transfected with poly(I:C), the suppressive action of compound 4 in this model was weak. In addition, compound 5, but not compound 4, exhibited at low doses proapoptotic properties with regard to colonic cell lines. In summary, we demonstrated the therapeutic potential of two selected azaphenotiazines in the amelioration of the skin pathology elicited in a mouse experimental model of psoriasis. HIGHLIGHTSTopical azaphenothiazines inhibit pathological skin changes in psoriatic mice.Azaphenothiazines suppress generalized cellular changes in lymphoid organs and circulating blood of psoriatic mice.Azaphenothiazines do not show side‐effects in psoriatic mice in contrast to the reference drug Clobederm®.Azaphenothiazines inhibit production of chemokines by a keratinocyte cell line.

Modulating effect of selected pharmaceuticals on bone in female rats exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

This paper discusses the problems connected with the influence of TCDD on the mechanical properties and structure of the bone tissue in female rats treated with the dioxin. Moreover an analysis of the protective role of tocopherol, acetylsalicylic acid, dexamethazone and levamisol was performed. Rat tibiae were assessed by mechanical testing, and histological and trace element analysis. It was proved that TCDD has negative effect on bone mechanical properties, histological microstructure and trace element content. The results indicate that usage of both steroid and non-steroid anti-inflammatory medicaments, along with tocopherol and levamisol, modulating their activity, can reduce the negative effect of dioxin activity on the bone tissue of female rats intoxicated with TCDD.

Influence of surface modifications of a nanostructured implant on osseointegration capacity – preliminary in vivo study

In response to the need for implant materials characterized by high biocompatibility a new type of nanostructured Ti6Al7Nb implants for osseous tissue regeneration have been fabricated. The nanostructured cylindrical implants were manufactured in accordance with 3D CAD data using the Selective Laser Melting (SLM) method. Implants were subjected to chemical polishing using a mixture of nitric acid and fluoride (test group) as well as cleaned in distilled water and isopropyl alcohol (control group). The structural and morphological properties of the obtained samples were determined by using XRD (X-ray powder diffraction), TEM (transmission electron microscopy) and SEM (scanning electron microscopy) techniques. The particle size was verified and calculated by Rietveld method to be in the range of 25–90 nm. In the present study, experimental in vivo tests concerning implants fabricated from a nanostructured Ti6Al7Nb alloy, which may substitute bone tissue, were discussed in detail. The control group and test group were used in the study. The animal model was New Zealand rabbit. The implants were implanted into skull fornix and observed after 1, 2 and 3 months. The results of macroscopic and microscopic analysis proved better osseointegration of chemically modified implants.