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M Wójcik

Publications and source records attributed to M Wójcik.

At least 19 recordsLinked to original sources
PubMed2004

Assessment of neutrophil components as markers of lung injury in the course of bovine respiratory tract infections.

To define the role of activated neutrophils in lung injury during bovine respiratory tract infections (BRTI) their in vitro function was investigated. As a means to achieve this goal the comparison of secretory action between neutrophils from the BRTI group and control was made on the basis of elastase, myeloperoxidase (MPO), alkaline phosphatase (ALK-P) release, and nitric oxide production. We noted that there is an interdependence between secretory response of neutrophils and clinical severity of BRTI. The release of elastase was greater in the BRTI group than in the control group (49.17+/-4.41 versus 46.43+/-4.95% of the total content). Neutrophils from infected heifers exhibited a significantly (p<0.05) higher value of MPO release than from healthy heifers and reached 39.23+/-10.18 versus 25.54+/-8.41% of the total content. ALK-P containing granules released significantly (p<0.001) more enzyme in the group with BRTI than in the control group (22.42+/-6.27 versus 13.74+/-2.01% of the total enzyme content). The level of nitrite accumulation rose in the culture of cells isolated from heifers with BRTI from 4+/-0.53 microM after 0.5h to 6.9+/-0.52 microM after 72 h. Our data suggest that during BRTI the increase of neutrophil secretory action results in augmentation of enzyme release including elastase, MPO and ALK-P, and the nitrite production. During an excessive secretory response of neutrophils all these factors contribute to lung injury and worsen the course of a disease and might be recognised as markers of lung injury. Moreover, such a destructive action of neutrophils must be taken into account during the introduction of new methods of BRTI treatment.

Alkaline Phosphatase↗
PubMed2004

Assessment of prognostic significance of cytoplasmic survivin expression in advanced oesophageal cancer.

Survivin is a member of the family of proteins, which inhibit apoptosis (inhibitor of apoptosis proteins - IAP). Expression of survivin was found in colorectal cancer, neuroblastoma, bladder cancer, non-small cell lung cancer, and breast cancer. There is some recent data indicating the correlation of poor prognosis and worse response to chemotherapy in patients with oesophageal squamous cell carcinoma (OSCC) expressing survivin. The aim of the present study was to assess survivin expression in cancerous tissue of patients with advanced OSCC and to test the potential correlation between survivin expression and clinicopathological data. Forty two patients (mean age 58.36+/-8.97 yrs), who were oesophagectomised due to squamous cell carcinoma of the thoracic oesophagus between 1998 and 2000, were retrospectively analysed. Cytoplasmic survivin expression, examined immunohistochemically, was found in 35 (83.33%) cases. No statistically significant correlation between survivin expression in the tumour and patients' gender, TNM stage, or vascular involvement was noted. The mean survival of patients with cytoplasmic survivin expression (17.81+/-5.51 months) was not statistically different to those with negative survivin staining (16+/-6.28 months) as assessed by Mantel-Cox test (p=0.49). Univariate regression analysis revealed UICC staging as the only predictor of survival in the analysed group (p<0.05). These results indicate that the cytoplasmic survivin expression does not seem to be the prognostic factor in advanced cases of OSCC.

Adult↗
PubMed2003

The response of bile secretion and ubiquinone Q10 to hyperglycaemia in sheep.

The aim of these investigations was to establish the secretion of ubiquinone Q10 (UQ10) in bile of sheep under glucose-induced cholestasis. Experiments were performed on 9 cannulated sheep divided into three groups: I-infused with sodium taurocholate, II-with Na-taurocholate plus glucose, III-with Na-taurocholate and glucose plus propranolol, phentolamine and atropine. Infusion of glucose increased plasma glucose concentration from 3.89 +/- 0.593 mM/l to 12.69 +/- 0.852 mM/l in 90 min and produced elevation of plasma insulin from 124.68 +/- 1.984 to 839.54 +/- 29.212 pM/l. Employment of blocking agents reduced insulin release to maximum 685.71 +/- 50.087 pM/l in 90 min. Under infusion of Na-taurocholate, bile flow averaged 14.016 +/- 0.706 microl/min/kg b wt. In the second group, bile flow decreased to 7.08 +/- 0.59 microl/min/kg b wt. in 90 min, and reached 11.25 +/- 0.25 microl/min/kg b wt in 240 min. Addition of the blocking agents in the third group, resulted in a significant (p < 0.05) decrease in bile flow to 3.733 +/- 0.680 microl/min/kg b wt in 105 min. This reduction of bile flow occurred with significant (p < 0.05) reduction of bile acids secretion that averaged 0.032 +/- 0.087 mM/min/kg in the first hour after glucose infusion and was maintained to the end of the experiment. Marked (p < 0.05) increase in UQ10 secretion was observed in both experimental groups. Maximum values of UQ10 secretion were obtained during the second hour of the experiment and averaged 0.449 +/- 0.196ng/min/kg b wt in the second, and 0.338 +/- 0.184ng/min/kg b wt in the third group of animals. Because at the end of the experiment UQ10 secretion gradually decreased we have concluded that free radicals generated during cholestasis lead to reduction of endogenous antioxidant capacity.

Animals↗
PubMed2001

Antisense hairpin loop oligonucleotides as inhibitors of expression of multidrug resistance-associated protein 1: their stability in fetal calf serum and human plasma.

Multidrug resistance-associated protein (MRP1) is a transmembrane pump protein responsible for the efflux of chemotherapeutic drugs, an important cause of anticancer treatment failure. Trying to circumvent MRP-mediated resistance we designed and synthesized hairpin loops forming antisense oligodeoxyribonucleotides (ODNs), both phosphodiesters (PO-ODNs) and their phosphorothioate analogues (PS-ODNs), to reduce the protein expression by targeting its mRNA in a sequence specific manner. Melting temperature measurements as well as polyacrylamide gel electrophoresis supported the preferential formation of a secondary structure, which was expected to protect ODNs against 3'-exonuclease degradation. ODNs and PS-ODNs designed in this work were successfully tested as antisense inhibitors of the expression of MRP1 in the leukaemia HL60/ADR cell line. Foreseeing the necessity to perform clinical studies with such ODNs we investigated their stability against the 3'-exonuclease activity of fetal calf serum and human plasma. Under the conditions, corresponding to physiological ones, we observed high stability of hairpin loop forming ODNs, especially those containing longer (e.g. 7 base pair) stems. Comparative studies on the stability of chemically unmodified hairpin loop forming ODNs and their PS-counterparts indicated that endonuclease activity did not play any important role in the process of their nucleolytic degradation. Our studies provide strong evidence for high stability of chemically unmodified hairpin loop ODNs, making them an attractive alternative to phosphorothioate analogues commonly used in antisense strategy.

Animals↗
PubMed2000

p53 protein detection by the western blotting technique in normal and neoplastic specimens of human endometrium.

The aim of the study was to investigate p53 protein expression by the Western blotting technique (estimated by integrated optical density - IOD) in normal (n = 13) and neoplastic (n = 40) human endometrial tissues as well as in a case of uterine carcinosarcoma and in a specimen of the botryoid sarcoma of the uterine cervix. p53 protein levels were correlated with patients' age as well as with conventionally used clinicopathological features of the endometrial neoplasm. A statistically significant difference was noted in p53 levels in the nuclear, but not in the cytoplasmatic, fraction between the normal endometria and endometrial cancer tissues (P < 0.0001). In the neoplastic endometria, nuclear p53 protein expression was higher than in cytoplasmatic fraction, and the difference was significant (P < 0.05). Higher nuclear p53 protein levels correlated with advanced histological grading of endometrioid endometrial carcinomas, but no relationship was noted between p53 protein expression and patients' age, clinical stage, histological type or depth of myometrial invasion. A case of uterine carcinosarcoma and a specimen of a botryoid sarcoma of the uterine cervix expressed nuclear p53 oncoprotein (57 IOD and 89 IOD, respectively). In conclusion, we found a statistically higher nuclear p53 levels in malignant as compared to normal human endometrial specimens by the Western blotting technique. Although there were no significant differences between p53 expression and clinicopathological features of the neoplasm (except poor histological grading), further studies are necessary to evaluate the influence of p53 nuclear/cytoplasmatic levels on the clinical outcome of Polish patients suffering from endometrial cancer.

Age Factors↗
PubMed2000

Effect of ethanol on ATP-induced phospholipases C and D and serine base exchange in glioma C6 cells.

The effect of extracellular ATP, a nucleotide receptor agonist in the central nervous system, was investigated in glioma C6 cells on the intracellular Ca2+ level and the formation of phosphatidylethanol and phosphatidic acid in the presence and absence of ethanol (150 mM). In the cells prelabeled with [14C]palmitic acid, 100 microM ATP induced both the hydrolysis and the transphosphatidylation reactions leading to the formation of [14C]phosphatidic acid; addition of ethanol generated [14C]phosphatidylethanol. However, ATP-mediated increase in the level of [14C]phosphatidic acid was not inhibited by ethanol. Furthermore, ethanol augmented ATP-induced transient and sustained increase in the intracellular Ca2+ concentration, whereas ethanol alone did not produce any change in the intracellular Ca2+ level. These results indicate that in glioma C6 cells, ATP induces activation of polyphosphoinositide-specific phospholipase C and phospholipase D and that ethanol enhances this effect. In the present investigation we have also shown that long-term (2 days) ethanol treatment, at concentration relevant to chronic alcoholism (100 mM), decreased the incorporation of [14C]serine into phosphatidylserine. Since the effect of ethanol on ATP-induced activities of phospholipase C and phospholipase D and on serine base-exchange in glioma C6 cells differs significantly from that in cultured neuronal cells, these results may contribute to a better understanding of the mechanisms of ethanol action in cells of glial origin.

Adenosine Triphosphate↗
PubMed2000

Solvation of Cr3+ cation in water-acetonitrile mixture studied by IR spectroscopy: molecular penetration into the solvation shells.

Infrared spectra of mixtures of water and deuteroacetonitrile containing the Cr3+ cation have been studied as a function of concentration, time and temperature. The CN stretching vibration of CD3CN molecules has been used as a probe of the structural environments. The CN band in the spectra of the solutions is a superposition of four subbands, which may be attributed to CD3CN bound in the first, second, and third solvation shells of the cation and to non-bound CD3CN. The character of changes of the integral intensities of the subbands with time for various H2O:Cr3+ molar ratios are explained by suggesting mechanisms of molecular replacement within the solvation shells of Cr3+.

Acetonitriles↗
PubMed2000

Multidrug resistance-associated protein--reduction of expression in human leukaemia cells by antisense phosphorothioate olignucleotides.

Multidrug resistance-associated protein (MRP1) causes cellular drug resistance in several cancer cell lines. In this paper we show that antisense oligonucleotides decrease MRP1 expression in human leukaemia cells. We investigated biological activity of a series of 12 linear phosphorothioate oligonucleotides, complementary to several regions of MRP1 mRNA. The oligonucleotides were administered to leukaemia HL60/ADR cells overexpressing MRP1 protein. Then, the level of MRP1 mRNA was determined by means of semiquantitative RT-PCR and the protein level by reaction with specific monoclonal antibodies. Some of the investigated antisense oligonucleotides decrease the expression level of the MRP1 protein by 46% and its mRNA level by 76%.

DNA-Binding Proteins↗
PubMed1999

Sphingosine, sphingosylphosphorylcholine and sphingosine 1-phosphate modulate phosphatidylserine homeostasis in glioma C6 cells.

The effect of sphingosine, sphingosylphosphorylcholine and sphingosine 1-phosphate on L-[U-14C]serine incorporation into phosphatidylserine and phosphatidylserine-derived phosphatidylethanolamine was investigated in intact glioma C6 cells. Sphingosine, sphingosylphosphorylcholine and sphingosine 1-phosphate are potent signalling molecules which, due to their physicochemical features, may function as amphiphilic compounds. It has been found that sphingosine and sphingosylphosphorylcholine (amphiphilic cations) significantly increase [14C]phosphatidylserine synthesis and decrease the amount of 14C-labeled phosphatidylethanolamine. Sphingosine 1-phosphate (an amphiphilic anion) was without effect on phosphatidylserine synthesis but, similarly as sphingosine and sphingosylphosphorylcholine, reduced the conversion of phosphatidylserine to phosphatidylethanolamine. These results strongly suggest that sphingosine, sphingosylphosphorylcholine and sphingosine 1-phosphate can modulate cellular phospholipid homeostasis by stimulation of phosphatidylserine synthesis and an interference with phosphatidylserine decarboxylase.

Brain Neoplasms↗
PubMed1999

[Non Hodgkin's lymphoma--treatment of choice and the role of high dose chemotherapy].

Non Hodgkin's Lymphomas protocols currently used at the CMUJ Department of Haematology in Cracow based on updated results of randomised trials are summarised. High dose chemotherapy with hematopoietic blood stem cell support is only one of the elements of modern NHL therapy; it's effectiveness depends on optimal indications and timing of the procedure.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

[Supportive therapy in patients with autologous hemopoietic stem cell transplantation].

Infectious complications remain one of the most serious diagnostic and therapeutic problems in modern hematology and are the major cause of morbidity and mortality following stem cell transplantation. Myeloablative therapy supported by haemopoietic stem cell transplantation remains standard policy in the treatment of certain haematological malignancies and solid tumors. Proper preventive strategies for patients in deep immunosuppression including prompt diagnosis and treatment of infections correlate with favourable prognosis and survival. Prophylaxis and therapy of bacterial, fungal and viral infections in neutropenic patients following myeloablative chemotherapy have been submitted in this article. Our guidelines are based on European Group for Bone and Marrow Transplantation recommendations and some European transplantological centres protocols. These standards were adapted to Polish conditions and now are used at Bone Marrow Transplantation Ward at Haematology Department at the Jagiellonian University.

Bacterial Infections↗
PubMed1999

Inhibition of plasminogen activator inhibitor release in endothelial cell cultures by antisense oligodeoxyribonucleotides with a 5'-end lipophilic modification.

A series of conjugates containing residues of lipophilic alcohols covalently bound to 5' end of oligodeoxyribonucleotides targeted against human plasminogen activator inhibitor (PAI-1) mRNA was synthesized via the oxathiaphospholane approach. The highest anti-PAI-1 activity in EA.hy 926 endothelial cell cultures was found for conjugates containing menthyl or heptadecanyl groups linked with an oligonucleotide complementary to a segment of human PAI-1 mRNA. The phosphodiester antisense oligonucleotides, which otherwise exhibit only limited anti-PAI-1 activity, were found to be more active than phosphorothioate oligonucleotides when conjugated to lipophilic alcohol residues. For menthyl conjugates an evidence of antisense mechanism of inhibition was found.

Base Sequence↗
PubMed1998

Novel internucleotide 3'-NH-P(CH3)(O)-O-5' linkage. Oligo(deoxyribonucleoside methanephosphonamidates); synthesis, structure and hybridization properties.

Diastereomeric dithymidine methanephosphonamidates (TnpmT) were synthesized by reaction of 3'-amino-3'-deoxythymidine with 3'- O -acetylthymidin-5-yl-methanephosphonochloridate. Separated dinucleotide TnpmT(fast) and TnpmT(slow) diastereomers were used as building blocks to prepare chimeric dodecathy-midylates, possessing one to four modified linkages, by means of phosphoramidite automated solid phase synthesis. As expected, the methanephosphonamidate internucleotide linkage is resistant to nuclease P1, snake venom PDE and 3'-exonuclease from human plasma. Degradation of dodecathymidylates possessing modified internucleotide linkages in alternate positions proved the 'hopping' properties of 3'-exonuclease. Oligo(deoxyribonucleotide methanephosphonamidates) were tested for their binding affinity to complementary oligomers in thermal denaturation experiments. All the oligomers showed lower binding affinity to DNA and RNA targets, however, oligomers originating from the TnpmT(fast) dimeric unit exhibited better hybridization properties than their diastereomeric TnpmT(slow) counterparts. A lowering of T m of approximately 2.4 degrees C (1.0-1.8 degrees C) was observed for each introduced TnpmT(fast) modification and 6.0 degrees C (4.2-5.0 degrees C) for each TnpmT(slow) modification in duplexes of modified dodecathymidylates with dA12(A12) oligomers. The oligo(deoxyribonucleoside methanephosphonamidate) designated F4, possessing four modified methanephosphonate linkages originating from the TnpmT(fast) diastereomeric unit, exhibits a tendency for triplex formation, as was demonstrated in thermal denaturation experiments with the d(A21C4T21) hairpin oligomer.

Animals↗
PubMed1998

Synthesis, biochemical and biological studies on oligonucleotides bearing a lipophilic dimethoxytrityl group.

Dimethoxytritylphosphono-oligonucleotide conjugates have been prepared. They are totally resistant to nucleases present in human serum and do not affect cleavage of a complementary oligoribonucleotide by RNase H. Conjugates possessing a phosphate backbone gave better antisense inhibition of expression of plasminogen activator inhibitor type-1 within endothelial cells as compared with unconjugated oligonucleotides.

Cells, Cultured↗
PubMed1997

Stability of stereoregular oligo(nucleoside phosphorothioate)s in human plasma: diastereoselectivity of plasma 3'-exonuclease.

The stability of stereoregular oligo(nucleoside phosphorothioate)s (PS-oligos) in human plasma has been studied. 3'-Exonuclease present in human plasma appeared to be RP specific, that is, it cleaves internucleotide phosphorothioate linkages of [RP]-configuration and not those of [SP]-configuration. Therefore, PS-oligos containing all phosphorothioate internucleotide linkages of [RP]-configuration [RP-PS-oligos]) are more effectively degraded by the enzyme than PS-oligos prepared via nonstereo-controlled methods (so-called random mixture of diastereomers [Mix-PS-oligos]), whereas oligo(nucleoside phosphorothioate)s of [S(P)]-configuration remain intact. The enzyme activity depends on the sequence of nucleobases. The presence of deoxycytidine units (three or more residues) at the 3'-end of PS-oligo substrate significantly inhibits the enzyme activity.

Drug Stability↗