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Biomedical subjects

M Zieliński

Publications and source records attributed to M Zieliński.

At least 19 recordsLinked to original sources
PubMed2006

Study of nickel nanoparticles supported on activated carbon prepared by aqueous hydrazine reduction.

Nickel nanoparticles were obtained by the reduction in hydrazine aqueous media of nickel acetate as a precursor supported on activated carbon of high surface area. Classical catalysts using nickel acetate or nitrate were prepared for comparison. The catalysts were characterized by N(2) physisorption, H(2)-TPR, H(2)-adsorption, TPD, TEM, and XRD, and tested in the gas phase hydrogenation of benzene. Hydrazine catalysts were found much more active in benzene hydrogenation than corresponding classically prepared catalysts. Remarkably, their reactivity is comparable (turn-over frequency of 0.2001-0.2539 s(-1) at 393 K) to that of Pt classical catalysts supported on activated carbon in the same conditions. Evidence is given for the existence of the hydrogen spillover effect in benzene hydrogenation, not reported before in the literature. As a result of the hydrogen spillover effect, catalysts performances can be explained by a combination of surface metal atom reactivity, metal-support interaction strength, and specific surface area extent. Maximum effect is observed with hydrazine preparation method, for 1% Ni content and nickel acetate as a precursor. Unexpectedly, it was also found that hydrazine preparation increases the specific area of the catalysts.

Journal Article↗
PubMed2003

Effects of atorvastatin, simvastatin, and fenofibrate therapy on monocyte chemoattractant protein-1 secretion in patients with hyperlipidemia.

OBJECTIVE: Monocytes that migrate into the arterial wall participate in the development and, eventually, rupture of the atherosclerotic plaque. The aim of this study was to evaluate the secretion of monocyte chemoattractant protein-1 (MCP-1) by monocytes from hyperlipidemic patients treated with hypolipidemic drugs, namely fenofibrate, simvastatin, or atorvastatin to determine what role is played by these drugs in the development and stabilization of the atherosclerotic plaque. METHODS: Fifty-four hyperlipidemic patients, who did not respond to a low-fat diet, were treated with fenofibrate, simvastatin, or atorvastatin (18 patients in each group) for 1 month. The control group included 18 normolipidemic, healthy, age-matched participants. Ten hyperlipidemic patients were effectively treated with hypolipidemic diet alone for 1 month. This group was compared with a control group of ten healthy subjects. To accurately evaluate the adhesion molecule levels, we excluded hyperlipidemic patients and control subjects with any inflammatory disease. Before and after treatment, monocytes were isolated from peripheral blood. After stimulation with lipopolysaccharide (LPS), MCP-1 secretion was measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: MCP-1 levels were significantly higher in hyperlipidemic patients than controls: 15.8+/-0.47, 16.7+/-0.23, and 14.9+/-0.45 compared with 12.36+/-0.42 ng/ml. Fenofibrate, atorvastatin, and simvastatin significantly decreased MCP-1 levels from 15.8+/-0.47 to 8.79+/-0.89, from 16.7+/-0.23 to 7.46+/-0.73, and from 14.9+/-0.45 to 10.3+/-0.8 ng/ml, respectively. In the diet-treated group of hyperlipidemic patients, the level of MCP-1 before therapy was significantly higher than in controls (16.89+/-0.31 vs 12.45+/-0.36 ng/ml). The diet therapy caused a significant decrease in levels of MCP-1 to 15.1+/-0.36 ng/ml. There was a correlation between the decreased levels of lipids and the decreased release of MCP-1 in the patients treated with hypolipemic drugs. CONCLUSION: The drug-induced decrease in MCP-1 secretion in hyperlipidemic patients suggests that, apart from acting on lipids, the hypolipidemic drugs studied may directly inhibit the activity of monocytes.

Atorvastatin↗
PubMed2002

Nitrogen-15 fractionation in the thermal decomposition of nitrous oxide of natural isotopic composition.

The 15N fractionation in the thermal decomposition of nitrous oxide (N2O) of natural isotopic composition has been investigated in quartz reaction vessel in the temperature interval 888-1073 K. The formulas relating the observed experimentally 15N fractionations with the primary 15N kinetic isotope effect, (k14/k15)p for 14N15N16O, and secondary 15N kinetic isotope effect, (k14/k15)s for 15N14N16O, have been derived. The experimentally estimated 15N kinetic isotope effects have been compared with the primary and secondary 15N kinetic isotope effects calculated with the absolute rate theory formulations applied to linear three atom molecules. A good agreement was found for the primary 15N kinetic isotope effect, (k14/k15)p, in the temperature interval 888-1007 K. But at 1073 K the decompositions of N2O, accompanied by NO (nitric oxide) formation proceed with a twice times smaller primary kinetic isotope effect, (k14/k15)p of 1.0251 +/- 0.0009, only, suggesting the nonlinear transition state structures with participation of the fourth external atom at high temperature decompositions of nitrous oxide. The nitrogen isotope effects determined in this study correlate well with nitrogen isotope fractionations observed in the natural biological, earth and atmospheric processes.

Atmosphere↗
PubMed2002

Plasma cytokines as predictors of coronary heart disease.

BACKGROUND AND OBJECTIVE: Growing body of evidence explicitly suggests the significant role of inflammatory processes in vascular diseases related to atherosclerosis. Monocytes, present in every phase of atherogenesis, are the principal cells accumulating in atherosclerotic plaque. Monocyte Chemotactic Protein 1 (MCP-1) seems to influence firm adherence of rolling monocytes and infiltration into the artery wall. Although the significant meaning of inflammation in atherogenesis has been proved, potential role of antiinflammatory cytokines remains unknown. Interleukin 10 (IL-10) is a major cytokine of pleiotropic antiinflammatory function known to exert inhibitory effects on monocytes. Recent data emerging from clinical and pathological studies suggest important role of thrombosis and fibrinolytic disorders in atherosclerosis complications especially in coronary heart disease (CHD). Individuals with greater Plasminogen Activator Inhibitor 1 (PAI-1) level are believed to be more susceptible to cardiovascular disease. METHODS: In our study we measured the plasma levels of MCP-1, IL-10 and PAI-1 in 10 patients with stable angina and 10 healthy subjects. We also estimated its mutual correlations. The plasma levels of MCP-1, IL-10 and PAI-1 were determined with R&D kits (ELISA). RESULTS: Plasma levels of MCP-1 were significantly higher (261.5+/-40.7 pg/mL vs 73.3+/-3.05 pg/mL; p<0.0002) and also levels of PAI-1 were higher (79.36+/-5.8 ng/mL vs 35.88+/-1.38 ng/mL; p<0.0001) in patients with SA compared with the healthy control subjects. Whereas plasma levels of IL-10 were lower (11.6+/-0.5 pg/mL vs 16.5+/-0.4 pg/mL; p<0.0001) compared with control group and correlated with both MCP-1 plasma level (r=-0.67; p<0.0015) and PAI-1 concentration (r=-0.69; p<0.0008). CONCLUSION: The data obtained confirm the predictive role of cytokines in patients with stable coronary heart disease. The negative correlation of anti-inflammatory IL-10 and PAI-1 was also found.

Adult↗
PubMed2001

Carbon isotope fractionation in the decarboxylation of phenylpropiolic acid in hydrogen donating media.

13C kinetic isotope effect (KIE) in the decarboxylation of phenylpropiolic acid (PPA) in tetralin medium (Tn) has been determined at 409-432 K and found to be of magnitude similar to the 13C KIE observed in the decarboxylation of malonic acid where the rupture of the C-C bond is the rate determining step. 13C KIE equals 1.0318/at 136 degrees C in the decarboxylation of PPA in Tn medium. Intramolecular 13C KIE in the decarboxylation of malonic acid equals 1.0316 at this temperature. Thus it has been shown that the nearly "full" 13C KIE can be achieved by providing the excess hydrogen to Calpha of PPA (or to triple acetylene bond) using not only strong mineral acids as the source of protons but also by carrying out the decarboxylation in organic medium like tetralin. A mechanism of decarboxylation of PPA in Tn is suggested.

Carbon Isotopes↗
PubMed2001

[Two cases of malignant mesothelioma of the pleura within one family].

The two patients (brothers) had in their early childhood contact with asbestos (asbestos blanket). Because of various degree of disease advancement, various methods of treatment were used. One brother was treated with radical surgery followed by radiotherapy; the other brother with more advanced disease underwent palliative treatment using chemotherapy. The patient who underwent surgery has been living for three years now free of tumour relapse, where's in the patient treated with chemotherapy, after partial remission of the disease, a relapse of tumor was observed. Currently, he undergoes symptomatic treatment. The cases above have been presented because the familial occurrence of this neoplasm is extremely rare and to show the possibility of radical surgical treatment of this type of neoplasm which has poor prognosis.

Adult↗
PubMed2001

[Experimental closure of bronchial stump after pneumonectomy with the greater omentum].

Authors present their results with experimental closure of bronchial stump after pneumonectomy with pedicled flaps of the greater omentum in sheep. In the experimental group left thoracotomy and laparotomy was performed. The left lung was resected and the bronchial stump was closed with the pedicled flap of the greater omentum. In controls standard left pneumonectomy was performed. After different periods of time (1-12 weeks) the animals were sacrificed, the bronchial stumps were excised and submitted to pathological studies. In none case bronchial fistula occurred. Pathological studies showed that the omentum at the base of the bronchial stump was transformed in the fibrous tissue. The bronchial epithelium begins to cover the omentum in 4 weeks after the operation and this process is finished in 12 weeks after the operation. Pedicled flap of the greater omentum seems to be useful in surgical treatment of bronchial fistulas.

Animals↗
PubMed2000

Technique of transcervical--subxiphoid-vats "maximal" thymectomy in treatment of myasthenia gravis.

Operative technique of transcervical-subxiphoid-VATS thymectomy is described. Total sternotomy is avoided which makes the procedure less invasive without compromising its radicality. The operation is performed with aid of special device with two sternal retractors elevating the sternum from above and below and facilitating access to the mediastinum. The mediastinal pleura is incised bilaterally and exenteration of the mediastinal fat is done under control of video camera inserted through the thoracoscopic ports. Two team approach is proposed: one team, called "the cervical" team performs dissection of the neck and the superior mediastinum; the "subxiphoid" team removes the fat tissue of the anterior mediastinum. This approach makes possible reduction of the operative time to 1.5-2 h. No complications were noted in the group of 8 patients operated on by the moment of submission of the abstract.

Humans↗
PubMed1998

[Levels of tumor necrosis factor alpha in serum of patients with hyperlipoproteinemia IIB before and after micronized fenofibrate therapy].

UNLABELLED: Tumor necrosis factor alpha (TNF alpha) secreted by activated macrophages stimulates proliferation and migration of vascular smooth muscle in atherogenesis. Up to now, the effect of fibrates on concentration of TNF-alpha has not been investigated. The aim of this study was to estimate TNF-alpha plasma concentration in healthy subjects before and after fenofibrate therapy in patients with hyperlipoproteinaemia IIb and to correlate their levels with plasma concentration of total cholesterol (TC), low density lipoproteins (LDL) and apolipoprotein B (ApoB). METHODS: 10 patients with hyperlipoproteinaemia IIb were treated with micronized fenofibrate (Lipanthyl 200 m-Fournier) for 1 month. Cytokines levels before and after therapy was measured by the ELISA method with Genzyme kits. RESULTS: The levels of lipid parameters at the onset study were as follows: TC: 265.4 +/- 9.4 mg%, TG: 344 +/- 53 mg%, LDL: 167.2 +/- 4.7 mg%, and ApoB: 1.62 +/- 0.05 g/l. After 1-month therapy with Lipanthyl 200 m the parameters decreased: TC 206 +/- 16 mg% (p < 0.05), TG: 194 +/- 30 mg% (p < 0.05), ApoB: 1.43 +/- 0.04 g/l (p < 0.01), and LDL: 144.4 +/- 12.9 mg% (ns). The decreased level of TC, TG and LDL correlated with the decreased concentration of TNF alpha. Before treatment the TNF concentration was 19.2 +/- 1.6 pg/ml and was higher than the concentration of control subjects (9.9 +/- 1.1 pg/ml, p < 0.01). After 1-month therapy the level of TNF alpha in blood from patient was 9.2 +/- 1.0 pg/ml (p < 0.01). The results of this study indicate that the concentrations of TNF alpha in plasma from hyperlipidemic patients are higher than concentrations of healthy subjects. Fenofibrate decreased the levels of this cytokine. This effect may be of significance for the treatment of HLPIIb and of atherosclerosis prevention.

Adult↗
PubMed1997

The influence of partial gastrectomy on the ultrastructural changes in the liver--an experimental animal model.

The aim of our studies was to evaluate the ultrastructural changes in the liver in rats after partial gastrectomy. The studied group consisted of 19 Wistar strain rats. In 15 animals partial gastrectomy was done. The control group underwent laparotomy, only. All tissue material was fixed and then prepared in a routinous way for histological and electron microscopy studies. During histological examinations no abnormalities were found. On the ultrastructural level (in tissue samples taken from animals, no more then 4 months after gastrectomy) we found mitochondrial degeneration, vacuolization of cytoplasm, abnormalities in the nuclei and increased activity of B-K cells. The focal necrosis of the hepatocytes was also observed. In tissue samples from animals after 4 to 12 months after primary operation we found increasing number and size of lipid vacuoles in the cytoplasm of hepatocytes The number of Ito cells increased, also. The gastrectomy caused only minimal ultrastructural changes in the liver tissue within the period of observation. Those changes described above may result from numerous metabolic derangements found after gastrectomy.

Animals↗
PubMed1996

[Cholesterol level as related to physical constitution and lifestyle of vocational school students].

In a group of 153 vocational school students aged between 16 to 19 years, somatic tests and determinations of selected hemodynamic parameters (total cholesterol together with HDL fraction, physical efficiency) (Ruffier-Dickson test and the classic "step-test") were carried out. At a detailed interview it was attempted to establish the lifestyle of the tested students and also their parents state of health. J.P. Guilford's interpretation was applied to these factors.

Adolescent↗
PubMed1994

[Influence of evening primrose oil on blood pressure and the pressor response to angiotensin II in pregnant and non-pregnant rabbits].

Evening primrose oil was given through a intragastric catheter in dose of 50 mg/kg day for 10 days to pregnant (8 animals) and nonpregnant (8 animals) rabbits. Control groups contained 8 pregnant and 8 nonpregnant animals. In the acute experiment we estimated directly (intraarterially) basal blood pressure and pressor response to angiotensin II (A II). The systolic and diastolic response to A II was significantly lower in pregnant rabbits which received evening primrose oil compared to control group. No significant effect was found in the nonpregnant groups. Basal (before A II) systolic and diastolic blood pressure did not differ between the treated and untreated subject in each group.

Angiotensin II↗
PubMed1993

[Non-malignant esophago-bronchial fistulas].

Pathogenesis, diagnosis and treatment of non-malignant esophago-bronchial fistulas is discussed. A case report of a 60 year old woman with such a disorder is presented. Surgical treatment completely cured this patient.

Bronchial Fistula↗