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Biomedical subjects

M Dabrowska

Publications and source records attributed to M Dabrowska.

At least 19 recordsLinked to original sources
PubMed2006

Effect of IFN-gamma stimulation on expression of intercellular adhesion molecule-1 (ICAM-1) on alveolar macrophages in patients with non-small cell lung cancer.

An impairment of in vitro cytotoxicity and tumoricidal function of alveolar macrophages (AMs) in patients with lung cancer was reported in a number of studies. The aim of our study was to evaluate the expression of intercellular adhesion molecule-1 (ICAM-1) on AMs after stimulation with interferon-gamma (IFN-gamma) in patients with non-small cell lung cancer (NSCLC). The study was performed in 13 patients with NSCLC, 6 patients with various nonmalignant pulmonary diseases, and 6 healthy volunteers. AMs were isolated from bronchoalveolar lavage fluid (BALF) by adherence and then cultured with or without IFN-gamma for 24 h. The expression of ICAM-1 on AMs was analyzed by flow cytometry. Stimulation with IFN-gamma caused increased expression of ICAM-1 on AMs in all studied groups (p < 0.05). The degree of the increase in ICAM-1 expression on AMs after IFN-gamma stimulation was significantly lower in patients with NSCLC compared with healthy volunteers (p = 0.002) or the other patients (p = 0.022). The results suggest impaired reactivity of ICAM-1 expression on AMs after stimulation with IFN-gamma in patients with NSCLC, which might be involved in functional defects of AMs in patients with NSCLC.

Adult↗
PubMed2004

Trichinella spiralis thymidylate synthase: cDNA cloning and sequencing, and developmental pattern of mRNA expression.

The persistent expression of thymidylate synthase activity has previously been demonstrated not only in adult forms, but also in non-developing muscle larvae of Trichinella spiralis and T. pseudospiralis, pointing to an unusual pattern of cell cycle regulation, and prompting further studies on the developmental pattern of T. spiralis thymidylate synthase gene expression. The enzyme cDNA was cloned and sequenced, allowing the characterization of a single open reading frame of 307 amino acids coding for a putative protein of 35,582 Da molecular weight. The amino acid sequence of the parasite enzyme was analysed, the consensus phylogenetic tree built and its stability assessed. The aa sequence identity with thymidylate synthase was confirmed by the enzymatic activity of the recombinant protein expressed in E. coli. As compared with the enzyme purified from muscle larvae, it showed apparently similar Vmax value, but higher Km(app) values desscribing interactions with dUMP (28.8 microM vs. 3.9 microM) and (6RS,alphaS)-N(5,10)-methylenetetrahydrofolate (383 microM vs. 54.7 microM). With the coding region used as a probe, thymidylate synthase mRNA levels, relative to 18S rRNA, were found to be similar in muscle larvae, adult forms and newborn larvae, in agreement with muscle larvae cells being arrested in the cell cycle.

Amino Acid Sequence↗
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 rate of apoptosis and expression of Bcl-2 and Bax in leukocytes of acute myeloblastic leukemia patients.

The rate of apoptosis as well as expression of Bcl-2 and Bax was evaluated before and after induction therapy in leukocytes of 70 patients with acute myeloblastic leukemia (AML), retrospectively divided into group A (with longer survival) and group B (with shorter survival). We found, that leukocytes of untreated AML patients showed susceptibility to apoptosis similar to control cells. Marked increase in percentage of apoptotic leukocytes was observed after induction therapy exclusively in patients with longer survival, which was accompanied by better normalization of routine hematological parameters. In this group, the Bcl-2/Bax ratio was similar to the control and remained unchanged after treatment. In AML patients with shorter survival, a twofold increase in this ratio was observed both before and after the completion of induction therapy. In both groups of untreated patients, western blot analysis revealed the presence of prominent additional bands reacting with anti-Bcl-2 or anti-Bax antibody, which were undetectable in control leukocytes. After the therapy, these bands disappeared, especially in patients from group A. In conclusion, the lack of therapy-induced enhancement in leukocyte apoptosis, an increased ratio of Bcl-2/Bax as well as persistent presence of abnormal Bcl-2 and Bax protein bands after induction therapy in AML patients may be considered as factors associated with unfavorable clinical outcome.

Adult↗
PubMed2003

Effects of ebelactone B on cathepsin A activity in intact platelets and on platelet activation.

PURPOSE: Previous in vitro studies have demonstrated that a potent antihypertensive agent ebelactone B inhibits cathepsin A/deamidase activity. The aim of our studies was to assess the effects of this inhibitor on cathepsin A activity in intact platelets and on platelet activation events. MATERIAL AND METHODS: PRP or washed human platelets from healthy volunteers were pre-incubated with different concentrations of ebelactone B (1-10 microM) for 10-60 min. Cathepsin A activity in platelets was assayed colorimetrically using Cbz-Phe-Ala at pH 5.5. Expression of platelet activation markers GpIIb/IIIa and P-selectin on non-activated or agonist-activated platelets (ADP, TRAP) was measured by flow cytometry. RESULTS: Pre-treatment of platelets for up to 60 minutes with 10 mumol/l ebelactone B, that effectively inhibits cathepsin A activity in platelet lysate, did not affect this activity in intact platelets. Exposure of PRP to 10 mumol/l ebelactone B alone, or before platelet activation with ADP or TRAP caused only a small but non-significant increase in P-selectin and GpIIb/IIIa expression on the platelet surface, as demonstrated by flow cytometry analysis. CONCLUSIONS: The lack of cathepsin A inhibition by ebelactone B in intact platelets indicates that this inhibitor does not enter cells. Therefore, a potential antihypertensive significance of this compound may be through the inhibition of cathepsin A/deamidase released from activated or damaged cells. In vitro ebelactone B seems to exert no effect on platelet activation. Further studies are underway to determine whether ebelactone B administration affects platelet activation events in experimental model of hypertension in rats.

Antihypertensive Agents↗
PubMed2002

Reactivity of alveolar macrophages in lung cancer patients and healthy subjects: surface ICAM-1 after INF-gamma stimulation in vitro.

The linearity of ICAM- I expression on alveolar macrophages (AM) before and after INF-gamma stimulation in healthy and lung cancer subjects were compared. AM were collected by bronchoalveolar lavage and incubated with/without INF-gamma according to standard procedures. The harvested cells were analyzed by flow cytometry using monoclonal antibodies against leucocytes and macrophages. Only viable cells were analyzed. Stimulation with INF-gamma revealed two AM subpopulations of similar size differentiated in the intensity of ICAM-1 expression. They were not distinctly marked in every studied case. Our preliminary results did not confirm the previously reported decreasing reactivity of AMs after INF-gamma stimulation in lung cancer patients.

Antineoplastic Agents↗
PubMed2002

Protein kinase C involvement in proliferation and survival of breast cancer cells.

Members of protein kinase C (PKC) family have been widely implicated in the regulation of cell proliferation, differentiation and survival. Increased protein C activity in malignant breast tissue and in most aggressive breast cancer cell lines suggests possible role of PKC in the development and progression of breast cancer. PKC may be therefore a target for breast cancer treatment. In our study we attempted to investigate the effect of: phorbol ester (PMA)-PKC activator, and bisindolylmaleimide II (GF II), a highly selective PKC inhibitor, on the proliferation as well as induction of apoptosis and necrosis in breast cancer cell line MDA-MB-231. Our results provide evidence for multidirectional effects of PKC on the proliferation of this type of breast cancer cells. The effects of both compounds were different after short time of exposition (1-3 h). PMA induced proliferation, while GF II showed an opposite effect. After 24 h, however, both compounds exhibited relatively high inhibitory effect on the proliferation and proved to be effective in induction of necrosis and apoptosis.

Apoptosis↗
PubMed2001

Potential role of beta 1 integrin and collagen biosynthesis in estrogen-dependent reduction of apoptosis in tamoxifen-treated breast cancer cells.

It was found that 10 microM tamoxifen induced apoptosis and a significant (approximately 50%) depletion of beta 1 integrin levels in human breast cancer cells. Estradiol-treated MCF-7 cells exhibited exceptional viability and adherence, high levels of beta 1 integrin and increased (by 100%) collagen biosynthesis. Pretreatment of MCF-7 cells with 1 nM estradiol prevented tamoxifen-induced cell death, loss of cell adherence and decrease in beta 1 integrin level. Tamoxifen and estradiol had an opposite effect on the beta 1 integrin level and adherence in breast cancer cells, suggesting that the decrease in the beta 1 integrin level may be an early event during tamoxifen-induced apoptosis in breast cancer cells.

Apoptosis↗
PubMed2001

13-cis retinoic acid and all-trans retinoic acid in the regulation of the proliferation and survival of human breast cancer cell line MCF-7.

Retinoids are a group of compounds which inhibit cell proliferation and induce cellular differentiation. The aim of this study was to compare the antiproliferative activity of various concentrations of 13-cis retinoic acid (isotretinoin) and all-trans retinoic acid (tretinoin) in a culture of the estrogen-sensitive human breast cancer cell line MCF-7. Evaluation was based on [3H]thymidine incorporation into the cancer cells and through immunocytochemical analysis of cell cycle-associated PCNA and Ki-67 protein expression. Both retinoids inhibited [3H]thymidine incorporation into the cancer cells most effectively at a concentration of 3x10(-3) M. Two basic substances used for line MCF-7 culture experiments, one stimulating - estradiol - and the other inhibiting - tamoxifen - were applied. Estradiol added to a culture containing decreasing concentrations of isotretinoin (from 3x10(-3) to 3x10(-8) M) caused a statistically significant reduction in the percentage of [3H]thymidine incorporation into the cancer cell line MCF-7, compared to the 17 beta estradiol group (189.25%+/-62.64, control=100%, p<0.05). In the group of decreasing tretinoin concentrations, statistically significant differences were found only at 3x10(-3), 3x10(-4) and 3x10(-8) M. Following culture supplementation with tamoxifen (1 microM), statistically significant differences were observed only at the highest concentrations of both retinoids (3x10(-3) and 3x10(-4) M). The evaluation of breast carcinoma cells with a positive immunocytochemical reaction to PCNA and Ki-67 has revealed that isotretinoin reduces their percentage in the most determined and statistically significant way (38.00%+/-2.58 and 39.25%+/-3.09), compared to the control group (86.50%+/-9.20 and 100%+/-3.87, p<0.001 and p<0.0001) and to the estradiol group (87.00%+/-6.79 and 86.10%+/-7.0, p<0.001). Apart from their blocking effect on the cell cycle, retinoids also induce the apoptotic pathway.

Antineoplastic Agents↗
PubMed2001

[Pseudolymphoma in patients with primary Sjogren's syndrome].

Sjögren's syndrome is an inflammatory autoimmune disease affecting primarily the exocrine glands. In the abscence of other autoimmune diseases it is classified as primary Sjögren's syndrome. Patients with primary syndrome have about 40 times higher relative risk of developing lymphoma then normal population, which offers a possibility to study malignant transformation's mechanisms in these patients. In the study we report a case of a woman with pseudolymphoma. The clinical diagnose used to be based on symptoms of proliferate disease, quetionnable histological evaluation and good response to steroids. Nowadays, applying advanced molecular techniques make it possible to diagnose lymphoma in labial salivary biopsy much earlier. It allows recognizing an incipient lymphoma in a group of patients with primary Sjögren's syndrome. Therefore so-called pseudolymphoma can usually be diagnosed as either benign or malignant lymphoproliferative lesions.

Adult↗
PubMed2001

[The routine coagulation tests along with activated protein C resistance (APC-R) in population of women applying for oral contraceptives].

The routine coagulation tests along with activated protein C resistance (APC-R) were studied in North-Eastern Poland women, applying for oral contraceptives. The APTT, PT and fibrinogen concentration were evaluated in 128 women, aged 20-40 years, by means of nephelometric method. For estimation of APC-R, Coatest APC Resistance V test was used. The abnormalities in routine coagulation test were found in 13.3% of studied women. The resistance to activated protein C was observed among 4.3% of women with normal results of routine coagulation tests. The thrombotic event occurred in one of five APC-R positive woman. There was no correlation between APC-V ratio and APTT, PT or fibrinogen values.

Activated Protein C Resistance↗
PubMed2000

Expression and purification of mammalian calreticulin in Pichia pastoris.

Calreticulin is a 46-kDa Ca(2+)-binding chaperone of the endoplasmic reticulum membranes. The protein binds Ca(2+) with high capacity, affects intracellular Ca(2+) homeostasis, and functions as a lectin-like chaperone. In this study, we describe expression and purification procedures for the isolation of recombinant rabbit calreticulin. The calreticulin was expressed in Pichia pastoris and purified to homogeneity by DEAE-Sepharose and Resource Q FPLC chromatography. The protein was not retained in the endoplasmic reticulum of Pichia pastoris but instead it was secreted into the external media. The purification procedures reported here for recombinant calreticulin yield homogeneous preparations of the protein by SDS-PAGE and mass spectroscopy analysis. Purified calreticulin was identified by its NH(2)-terminal amino acid sequences, by its Ca(2+) binding, and by its reactivity with anti-calreticulin antibodies. The protein contained one disulfide bond between (88)Cys and (120)Cys. CD spectral analysis and Ca(2+)-binding properties of the recombinant protein indicated that it was correctly folded.

Amino Acid Sequence↗
PubMed2000

Trichinella spiralis and Trichinella pseudospiralis: developmental patterns of enzymes involved in thymidylate biosynthesis and pyrimidine salvage.

Thymidylate synthase, dihydrofolate reductase and dUTPase specific activities were found to remain at a high and constant level in crude extracts from adult worms of Trichinella spiralis, as well as from muscle larvae of both Trichinella spiralis (isolated 1-24 months after infection) and Trichinella pseudospiralis (isolated 5.5-13 months after infection). The results obtained with Trichinella pseudospiralis muscle larvae isolated with the use of pepsin did not differ from those obtained when pepsin was not used. No thymidine kinase activity could be detected in muscle larvae of either species and thymidine phosphorylase could be found only in T. pseudospiralis larvae isolated without the use of pepsin. Muscle larvae of both species contained orotidylate phosphoribosyl transferase activity, pointing to a possibility of 5-fluorouracil activation. Uridine phosphorylase, another enzyme involved in 5-fluorouracil anabolism, was also present in T. pseudospiralis muscle larvae. Results of comparative studies on inhibition of purified T. spiralis and rat thymidylate synthases by substrate (4-thio-5-fluoro-dUMP, 2-thio-5-fluoro-dCMP and N4-hydroxy-dCMP) and cofactor (ZD 9331) analogues indicated only dUMP analogues to show feeble selectivity towards the parasite enzyme. A hypothesis is discussed, assuming high expression of thymidylate synthase in muscle larvae to be connected with their cells being arrested in the cell cycle.

Animals↗
PubMed2000

Reactive oxygen species activate mitogen-activated protein kinases in pancreatic acinar cells.

It has been recently reported that kinases that belong to the mitogen-activated protein kinase (MAPK) family are rapidly activated by cholecystokinin (CCK) in rat pancreas both in vitro and in vivo. It is known that reactive oxygen species (ROS) play an important role in the pathogenesis of acute pancreatitis induced by supraphysiologic stimulation with CCK analogue, cerulein. The aim of our study was to evaluate whether MAPKs are activated by ROS in pancreatic acini. The activity of MAPK, c-Jun amino-terminal kinase (JNK), and p38 MAPK was determined in isolated rat pancreatic acinar cells by means of Western blotting, with the use of specific antibody that recognizes active, dually phosphorylated kinases. Incubation of acini with ROS donors, hydrogen peroxide (H2O2) and/or menadione (MND), strongly activated all three kinases. Activation of these kinases by ROS, but not by CCK, was substantially inhibited by pretreatment of acini with antioxidant N-acetylo-L-cysteine (NAC). Whereas CCK-induced activation of MAPK or JNK was totally or partially blocked by protein kinase C (PKC) inhibitor GF-109203X, ROS-induced activation of MAPK, JNK, and p38 MAPK was PKC independent. In conclusion, ROS strongly activate MAPK, JNK, and p38 MAPK in pancreatic acinar cells. It may be of importance in acute pancreatitis, because ROS are involved in the pathogenesis of this disease.

Acetylcysteine↗
PubMed2000

[The phenotype characteristics of cord blood lymphocytes in premature neonates].

It has been observed high risk of infections in neonates as a result from lymphocytes immaturity. It is connected to phenotype differences of lymphocytes between neonates and adults. This high susceptibility to infections is especially high in premature neonates. With the use of flow cytometry we have evaluated the phenotype of cord blood lymphocytes in premature neonates. In comparison to results of healthy newborns we have observed significant decrease in CD7+, CD3+, CD4+, CD25+, CD57+ lymphocytes an increase in total number of CD8+ cells as well as alteration in CD4/CD8 ratio. Our results suggest deeply damage of cellular immunity in preterm infants.

Antibodies, Monoclonal↗
PubMed2000

alpha1-microglobulin as a marker of proximal tubular damage in urinary tract infection in children.

The urinary alpha1-microglobulin (alpha1-M) as a marker of proximal tubular damage was measured in 86 children, aged 3/12 to 12 years, with a diagnosis of urinary tract infection (UTI) and fever. All patients had normal glomerular filtration rates (GFR). They were divided into 2 groups: A: with UTI and etiological factor E. coli, B: with UTI and etiological factor Proteus sp. Similar measurements of alpha1-M were obtained for a control group of healthy children. An increased mean level serum alpha1-M was observed in patients with UTI and fever compared to control group (p < 0.001). Urinary alpha1-M as the alpha1-microglobulin/creatinine ratio was higher in both tested group of patients with UTI and fever. Those found in group A1 and B1 before treatment were the highest and statistically significantly elevated after treatment (group A2 and B2: p < 0.001). Our results indicate the usefulness of the urinary alpha-microglobulin/creatinine ratio as a marker of proximal kidney tubule damage in children with E. coli and Proteus sp. infections. Additionally, it seems to be associated with the humoral and cellular immune response.

Alpha-Globulins↗
PubMed2000

Influence of estrogen, antiestrogen and UV-light on the balance between proliferation and apoptosis in MCF-7 breast adenocarcinoma cells culture.

Studies of the mechanism of actions of estrogen, antiestrogen and physical factors may provide clues to an understanding of breast cancer growth and/or regression regulation and thus identify novel targets for therapeutic intervention. Defective control of apoptosis appears to play a central role in the pathogenesis of neoplasia. Conversely, cancer therapy and ionizing radiation can induce cancer cell death by apoptosis and/or necrosis. bcl-2 gene and p-53 gene products have been both linked to programmed cell death pathways. We have analyzed the effect of estradiol, tamoxifen and UV exposure on the induction of apoptosis, expression of p53 and bcl-2 gene products as well as the proliferative activity (expressed as [3H]thymidine incorporation and PCNA and MPM2 antigens involvement) in MCF7. It has been found that estradiol increases the speed of cell cycle in MCF7 and acts as antiapoptotic factor. Tamoxifen has multiple influence on the rate of growth of cancer cells: depends on estrogen receptor (ER), conducts reduction of proliferation rate; depends on ER and other mechanisms conducts to suppressions of Bcl-2 protein expression and induction of cell death through apoptotic pathway. Estradiol prevents the apoptotic influence of tamoxifen probably by enhancement of Bcl-2 protein expression and does not prevent the inhibition of proliferation rate. The irradiation with UV induces apoptosis by over-expression of p53 and down-regulation of bcl-2 gene.

Adenocarcinoma↗