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Biomedical subjects

B Siwek

Publications and source records attributed to B Siwek.

At least 19 recordsLinked to original sources
PubMed1999

Total serum sialic acid concentration as a supporting marker of malignancy in ovarian neoplasia.

The present study was undertaken to establish the diagnostic utility of total sialic acid (SA) determination in the serum of patient with ovarian neoplasia. In a group of 29 patients with histopathologically confirmed ovarian neoplasia, concentrations of total SA was determined. In addition, the two tumor markers: CA125 antigen level and lactic dehydrogenase (LDH) activity were determined. The mean value of serum total SA in patients (1.76 mmol/L) was significantly higher than in the control group of healthy women (1.52 mmol/L). The elevation of serum total SA was associated with the burden of the tumor: higher total SA levels were observed in the cases of more developed malignancies. A significant correlation has been found between serum total SA content and CA125 level in patients with undifferentiated ovarian cancers. It has been concluded that total serum sialic acid level reflects the development of malignancy and should be considered as a supporting tumor marker in ovarian cancer diagnosis.

Adult↗
PubMed1999

[The evaluation of nitrate and nitrite contents in diets of preschool children].

The contents of nitrites and nitrates in whole day's food of children at preschool age have been examined. Meals consisted of three dishes were taken from one of the day nurseries in Lódź in January 1996. In the evaluation of the degree of exposure the highest permissible daily intake was considered of nitrites (0.2 mg NaNO2) and nitrates (5 mg KNO3) for kg of body weight and assumed average body weight was 20 kg for children. The contents of nitrites and nitrates were determined spectrophotometrically on the basis of Griess reaction. Nitrates were reduced to nitrites passing anaquelos extract of the studied sample through a column filled with cadium dust. The range of quality of collected nitrates in meals in wide and the quantity oscillate between 8.9 and 127, mg KNO3, the average quantity is 55.01 mg KNO3. The quantity of collected nitrites is between 0.5 and 3.8 mg NaNO2 and the average quantity is 1.58 mg NaNO2.

Child↗
PubMed1999

[The evaluation of nitrates and nitrites in daily food intake of adults].

During the research work the contents of nitrates and nitrites in whole day's food of adults were examined. The study were carried out in February 1996. In the evaluation of the degree of exposure highest permissible daily intake was considered of nitrites (0.2 mg NaNO2) and nitrates (5 mg KNO3) for one kg of body weight, and the assumed average body weight was 60 kg for adults. The contents of nitrites and nitrates were determined spectrophotometrically of the basis of Griess reaction. Nitrate was determined colorimetrically using sulphanic acid and N-1-naphtyl-ethylene-diamine. The quantity of collected nitrates and nitrites in whole day's food oscillates between 69.5 and 737.5 mg KNO3 and the average quantity is 304.55 mg KNO3. The quantity of collected nitrites is in the average 1.8-8.4 mg NaNO2, and the average quantity is 4.39 mg NaNO2.

Adult↗
PubMed1998

Establishment and characterization of three new breast-cancer cell lines.

We have established and characterized 3 new breast-cancer cell lines from pleural effusions of patients with advanced breast cancer. All 3 cell lines, designated IBEP-1, IBEP-2 and IBEP-3, showed typical ultrastructural characteristics of epithelial mammary tumor cells. Electron microscopy showed, among other characteristics, the presence of numerous microvilli, desmosomal junctions, intracytoplasmic duct-like vacuoles, well-developed endoplasmic reticulum and large nuclei. Immunohistochemical and biochemical studies revealed that the 3 cell lines expressed cytokeratin, epithelial membrane antigen, CEA and CA 15-3, but all showed negative immunoreaction for vimentin. On the other hand, other antigens (LEU-M1, GCDFP 15, c-erbB-2) were expressed by some of the cell lines, but in a variable manner. Ploidy studies confirmed the neoplastic origin of the cell lines. The doubling times were 68 hr for IBEP-1, 29 hr for IBEP-2 and 39 hr for IBEP-3. Only IBEP-2 cells expressed estrogen receptors (ER+), which were down-regulated after preincubation with E2, but they did not express progesterone receptors (PgR-). IBEP-1 and IBEP-3 cells were ER- but expressed PgR (PgR+). In these 2 cell lines, PgR were down-regulated after pre-incubation of the cells with progesterone (10(-8) M) for 24 hr. Estradiol (E2) increased the proliferation rate of IBEP-2 cells and progesterone increased the proliferation of IBEP-I and -3 cell lines. S.C. injection of the 3 IBEP cell lines into nude mice resulted in the growth of solid tumors between 11 and 16 weeks after inoculation. These cell lines could thus be new models for studying various aspects of the biology and the tumorigenicity of breast-cancer cells. A major interest of these new cell lines is that 2 of them were ER- and PgR+, which is an exceptional phenotypic feature. These 2 cell lines could be interesting models for studying the regulation of PgR and the effects of progestins and antiprogestins independently of the presence of ER.

Aged↗
PubMed1998

Production and regulation of interleukin-11 by breast cancer cells.

We have studied the production of interleukin-11 (Il-11) in 13 breast cancer cell (BCC) lines. Two of these cell lines (MDA-MB-231 and Hs578T) expressed the cytokine at both the protein and mRNA levels. Il-11 did not modulate the growth of five BCC lines examined, including the two cytokine-producing BCC lines. The production of Il-11 was increased by transforming growth factor-beta1 in a dose-dependent manner with a rapid (2 h) and transient (24 h) mRNA induction, but not by epidermal growth factor, insulin-like growth factor-I and -II, basic fibroblast growth factor, platelet-derived growth factor or parathyroid hormone. The cyclic AMP inducer, forskolin, and the activator of protein kinase C, phorbol 12-myristate 13-acetate, also stimulated the production of Il-11. Besides Il-11, MDA-MB-231 and Hs578T were the only BCC lines to produce interleukin-6 (Il-6) protein and mRNA. Since Il-11 and Il-6 are potent stimulators of osteoclast development and bone is a major source of TGF-beta1, our data suggest that Il-11, together with Il-6, contributes to the high bone destructive capacity of MDA-MB-231 cells and could play a role in breast cancer-induced osteolysis.

Breast Neoplasms↗
PubMed1998

Breast cancer cell response to calcitonin: modulation by growth-regulating agents.

Calcitonin may induce cyclic AMP production by breast cancer cells and inhibit their growth. The molecular complex leading to cyclic AMP production in response to calcitonin is made of the calcitonin receptor coupled to the adenylate cyclase by at least one guanine nucleotide-binding protein (G-protein, of the Gs type). Our aim was to determine whether and how the responses of cells to calcitonin were modulated by growth-regulating agents not directly acting through the cyclic AMP pathway. We found that the cyclic AMP response to calcitonin was reduced after preincubation of cells with the mitogens 17beta-estradiol and epidermal growth factor (EGF), while it was enhanced after preincubation with the growth inhibitors tamoxifen and 1,25(OH)2D3, as well as with an antisense oligonucleotide to the proto-oncogene c-myc. Scatchard-plots revealed no significant change in the calcitonin receptor number or affinity. On the other hand, the cyclic AMP production of cells in response to activators unrelated to calcitonin, such as forskolin, a direct adenylate cyclase effector, and isoproterenol, a beta-adrenergic receptor agonist, was modulated only weakly or not at all by the growth-regulating agents. This suggested that the effects observed were essentially calcitonin-specific and associated with events located between the calcitonin receptor and the adenylate cyclase. Since a Go- or Gi-protein has been previously implicated in the calcitonin signal transduction, we tested the action of pertussis toxin, a specific inhibitor of these G-proteins. Pertussis toxin produced a general increase in the cyclic AMP response of cells to calcitonin; moreover, the toxin almost abolished the effect of mitogens and antimitogens on that parameter. We conclude that in breast cancer cells, the calcitonin receptor and the adenylate cyclase are coupled by at least one Go/Gi-protein sensitive to growth-regulating agents; this results in a modulation of the cyclic AMP response to calcitonin by these agents. On the other hand, the growth-inhibitory effect of calcitonin on breast cancer cells was reduced by 17beta-estradiol and enhanced by tamoxifen. We suggest that this could be a consequence of changes in cyclic AMP levels and deserves further investigation.

Breast Neoplasms↗
PubMed1997

NOTE

The adsorption kinetics of negatively charged polystyrene latex at mica surface precovered with smaller sized (submicrometer) latex particles was investigated experimentally. The direct microscope observation method combined with the impinging jet technique was used in this study. Experimental results were presented concerning the initial flux and adsorption kinetics of larger particles at surfaces partially covered with smaller sized latex particles. The experimental results were interpreted in terms of the Monte Carlo simulations performed using the random sequential adsorption (RSA) model. Limiting analytical solutions for predicting the initial flux and adsorption kinetics were also formulated. It was found that the experimental results were in good agreement with theoretical predictions (derived for hard particle interaction potential). This confirmed the hypothesis that small colloid particles present in low concentration at surfaces considerably diminish adsorption rates of larger particles. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Characterization of non pigmented B16 melanoma cell-derived cytotoxic factors.

We analyzed and tried to characterize substance(s) responsible for cytotoxic activities detected in culture media conditioned by non pigmented B16 melanoma cells (NPB16). The different cytological tests used showed that ultrafiltrated conditioned media (CM U1 fraction) contained several cytotoxic factors with a Mw lower than 1000 Da. These factors seemed to act either directly or indirectly on cell membranes, mitochondria, on the cell cycle and on protein and DNA synthesis. A cytotoxic activity could be found even after high dilution of CM U1. These cytotoxic factors were rapidly released by B16 cells in culture, independently of cell confluence. Their activities in the treated cells were also very fast and the cytotoxic effects were irreversible after only a few hours of treatment. These factors were not intermediate products during melanogenesis, neither polyamines, nor proteases. At least one of them seemed to be a small acidic and basic stable peptide without disulfide bounds but not heat stable. The synthesis of at least one of these cytotoxic factors was inhibited by cycloheximide and the cytotoxic activity was partially destroyed by pronase and trypsin, but not by pepsin. The cytotoxicity was not modified by copper complexants or free radical inhibitors (bovine serum albumin (BSA), tyrosine, superoxyde dismutase (SOD), catalase, vitamin E). Furthermore the levels of glutathione peroxydase activity and reduced glutathione did not change after treatment by CM U1 as compared to controls.

Animals↗
PubMed1997

Influence of Polydispersity on Random Sequential Adsorption of Spherical Particles

Random sequential adsorption (RSA) of polydisperse mixtures of hard and interacting spherical particles was analyzed. Theoretical results were derived by performing numerical MC simulations both for Gaussian and for continuous distributions of particle sizes characterized by standard deviations below 20%. Adsorption kinetics of these mixtures was determined for a broad range of times showing that for tau < 5 the influence of polydispersity was rather minor for both Gauss and continuous particle size distributions. More significant deviations were predicted for the asymptotic adsorption regime close to jamming. In the case of continuous distributions this limiting kinetics could be described by the power law dependence thetainfinity - theta approximately tau-1/3 in accordance with the predictions of G. Tarjus and J. Talbot (1991, J. Phys. Math Gen. 24, L913). The jamming concentration thetainfinity for hard (noninteracting) particles was found to increase proportionally to sigma;. It was also shown that the polydispersity of particle mixtures can exert an effect on the structure of the adsorption layer (characterized in terms of the pair correlation function). The broadening of this function was confirmed experimentally by using colloid suspensions of spherical particles (polystyrene latex) characterized by sigma; = 6-10%.

Journal Article↗
PubMed1997

Secretory products of breast cancer cells specifically affect human osteoblastic cells: partial characterization of active factors.

The pathogenesis of tumor-induced osteolysis (TIO) following breast cancer metastases in bone remains unclear. We postulated that osteoblasts could be target cells for the secretory products of breast cancer cells. We previously showed that serum-free conditioned medium (CM) of the breast cancer cell line MCF-7 inhibits DNA synthesis by 75% of control values in osteoblast-like cells SaOS-2 and that this effect is only in a minor part due to transforming growth factor beta secretion. To establish the specificity of our observations and to look for other biologically active factors, we have tested the effects of medium conditioned by several cancer and noncancer cell lines (breast, colon, placenta, or fibrosarcoma) on the proliferation of osteoblast-like cells (SaOS-2, MG-63), normal human osteoblasts, human fibrosarcoma cells, and normal human fibroblasts. Culture medium (1:2) of the breast cancer cell lines MCF-7, T-47D, MDA-MB-231, and SK-BR-3 inhibited by 25-50% the proliferation of osteoblast-like cells SaOS-2, MG-63, and normal osteoblasts as evaluated by the MTT survival test or [3H]thymidine incorporation. MCF-7 cells completely inhibited the proliferation of normal human osteoblasts in coculture. This inhibitory effect was reversible and not due to cytotoxicity. Moreover, the cyclic adenosine monophosphate (cAMP) response to parathyroid hormone (PTH) of osteoblast-like cells SaOS-2 was also increased by 100-240% by the same CM. Such activities were, however, not detected in medium from the breast noncancer cell line HBL-100 or in the medium conditioned by non-breast cancer cell lines (COLO 320DM, HT-29, JAR, or HT-1080). Medium from the breast cancer cells had no effect on normal human fibroblasts or fibrosarcoma cells (HT-1080), suggesting the specificity of their action on human osteoblasts. After partial purification by ultrafiltration and size-exclusion chromatography, we found that medium of T-47D cells contained at least three nonprostanoid factors of low molecular weights (apparent MW of 700, 1500, and 4000 D) which affected human osteoblast-like cells. These factors were heat stable and could be peptides without disulfide bonds. In summary, our data show that human breast cancer cells release soluble factors that inhibit osteoblast proliferation and increase their cAMP response to PTH, indicating that osteoblasts could be important target cells for breast cancer cells and could be involved in the process of TIO.

Breast Neoplasms↗
PubMed1996

Effects of secretory products of breast cancer cells on osteoblast-like cells.

The pathogenesis of breast cancer-induced osteolysis remains largely unknown. To evaluate the potential role of osteoblasts as target cells during this process, we incubated SaOS-2 human osteoblast-like cells (OBL) with culture media conditioned by proliferative (PM, 'Proliferation Media') or confluent (CfM, 'Confluence Media') MCF-7 human breast cancer cells. CfM decreased the growth of OBL by 26% (P < 0.01) while PM was without significant effect on this parameter. In contrast, both PM and CfM obtained from MCF-7 cultures increased the cyclic AMP (cAMP) response of OBL to the osteolytic agents PTH (10(-8) M) and PTH-related peptide (PTHrP, 10(-8) M) by a factor of about 3 (P < 0.001), and to prostaglandin E(2) (PGE(2),10(-6) M) by a factor of about 2 (P < 0.01). No significant modulation of OBL growth or sensitivity to PTH, PTHrP, or PGE2 was induced by media obtained from HBL-100 non-malignant immortalized breast epithelial cell cultures. 17betaestradiol (E(2), 10(-8) M) and the antiestrogen tamoxifen (Tam, 10(-7) M) added for 48 h to MCF-7 cultures before collecting conditioned media attenuated and potentiated, respectively, the PM- but not the CfM-induced increase in the response of OBL to PTH or PTHrP Along the same line, the addition to MCF-7 conditioned media of a polyclonal anti-transforming growth factor-beta (TGF-beta) antibody attenuated by about 25% (P < 0.01) the PM-induced increase in OBL response to PTH and PTHrP while abrogating the modulatory effects of E(2) and Tam on that response. Together, our results indicate that MCF-7 breast cancer cells secrete factors which inhibit the growth of OBL and increase their sensitivity to various osteolytic agents. TGF-beta was only partly responsible for these effects, and accounts for their modulation by E(2) and Tam. The identification of other osteoblast-modulatory factor(s) should contribute to a better understanding and treatment of breast cancer-induced osteolysis.

Adenocarcinoma↗
PubMed1995

[Content estimation of nitrates and nitrites in vegetables from the province of Lodz].

The contents of nitrates and nitrites in selected vegetables reaped in summer and autumn in 1993 were investigated. The samples of vegetables were collected directly from the producers from area of Lódź and from outside of the city. Nitrates were reduced on a cadmium column to nitrites, where-upon they were determined colorimetrically using sulfanilic acid and N-1-Naphthylethylenediamine. It has been found that the contents of nitrates in tested vegetables are mostly higher than the allowable values published in the Ordinance of Minister of Health and Social Welfare from 8th of October 1993. The average contents of nitrates and nitrites in most of tested vegetables were higher in the vegetables from the outskirts of the city than in ones from outside of the city in the province.

Colorimetry↗
PubMed1995

[Studies on the contents of nitrates and nitrites in selected fresh and heat processed vegetables].

The levels of nitrates and nitrites were determined in fresh vegetables and the same products subjected to culinary processing such as boiling. Nitrates were reduced on a cadmium column to nitrites, where upon they were determined colorimetrically using sulfanilic acid and N-1-naphthyl-ethylenediamine. Thermal processing of these vegetables reduced the level of nitrates by about 50% and the nitrites loss reached even 100%.

Colorimetry↗
PubMed1994

Effect of selenium compounds on murine B16 melanoma cells and pigmented cloned pB16 cells.

The effects of selenium compounds such as sodium selenite, sodium selenate, seleno-DL-cystine and seleno-DL-methionine (100 microM and 10 microM) on B16 and pigmented cloned pB16 murine melanoma cells were investigated in vitro. At the tested concentrations, B16 cells showed a greater sensitivity to the toxic effects of sodium selenite and seleno-DL-cystine than pB16 cells, whereas no decrease of B16 and pB16 cell number was observed after incubation with sodium selenate or seleno-DL-methionine. Glutathione (GSH) percentages were strongly decreased only by selenite and seleno-DL-cystine; it was marked more in B16 than in pB16 cells. The pretreatment of B16 cells with a GSH depleting agent (10 microM buthionine-[S,R]-sulfoximine) did not significantly influence the cytotoxic effects of selenite and seleno-DL-cystine. On both cell populations, GSH preincubation (50 microM) enhanced the cytotoxicity of selenite whereas the survival of seleno-DL-cystine treated cells was increased. Glutathione peroxidase (GSH-Px) activity in B16 cells was more sensitive than in pB16 cells to the activating effect of selenite, and particularly of seleno-DL-cystine: however, cell-free controls indicated that activation was mainly due to glutathione reductase. The rate of 75Se (as sodium selenite) uptake in both cell populations was maximal within the first hour of incubation, with a preferential accumulation in the cytosol; after 24 h of incubation, the amount of 75Se in cytosol and pellet was approximately the same.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Effects of trace metals on mouse B16 melanoma cells in culture.

The effects of fourteen metal ions (As3+, As5+, Cd2+, Co2+, Cr3+, Cr6+, Hg2+, Li+, Mg2+, Mn2+, Ni2+, Se4+, V5+, VO2+) on the proliferation and differentiation in mouse B16 melanoma cells cultivated in vitro were analyzed. Cell number assays, melanin, and protein measurements, a 3(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide reduction test (MTT survival test), and a clonal growth assay were performed. At 10(-4)M, metal ions such as As3+, As5+, Cd2+, Cr6+, Se4+, V5+, VO2+, and, to a minor extent, Li+, Hg2+, and Co2+ significantly reduced the number of the B16 melanoma cells. For the same molar concentration, the order of the levels of cell toxicity of the metal compounds to B16 cells as measured by the MTT test was as follows: Hg2+ > Cr6+ = Cd2+ > As3+, As5+, > V5+, VO2+ > Se4+ = Ni2+ = Co2+ = Li+. An increased synthesis of melanin in B16 cells was noted after incubation with Co2+, Ni2+, Cd2+, and Li+, whereas Se4+ had, on the contrary, an inhibiting effect on melanogenesis.

Animals↗
PubMed1993

[A case of uterine foreign body present for many years].

A clinical case of a perennial presence of fragments of fetus skull is presented in the article. Patient was treated symptomatically for 5 years for irregular menstrual cycles. Only USG examination and a probationary biopsy explained the exciting cause. It became evident that a perennial presence of a foreign body in uterus need not induce dramatic clinical symptoms.

Adult↗
PubMed1988

The relative importance of Escherichia coli exonuclease III and endonuclease IV for the hydrolysis of 3'-phosphoglycolate ends in polydeoxynucleotides.

In vitro, in the presence of Mg++, the 3'-phosphoglycolatase activity of endonuclease IV is about 4-times smaller than that of exonuclease III for the same AP endonuclease activity. It thus seems that endonuclease IV has only a minor role in the repair of strand breaks limited by 3'-phosphoglycolate ends in Escherichia coli even after the amount of enzyme has been increased by induction with O2 -generating agents.

Bacterial Proteins↗