Biomedical subjects

Krzysztof Olszewski

Publications and source records attributed to Krzysztof Olszewski.

9 recordsLinked to original sources

PubMed2004

Successful treatment of giant right coronary artery aneurysm mimicking right atrium thrombus--a case report.

Coronary artery aneurysms are very rare abnormalities in patients undergoing coronary angiography. Clinical manifestation is usually that of coronary artery disease, and acute myocardial infarction. We present the case of a patient admitted to the Department of Cardiac Surgery due to coronary artery disease and the presence of thrombus in right atrium of the heart diagnosed by transthoracic echocardiography. Coronary angiography showed occlusion of the right coronary artery (RCA) in its middle portion, 20% stenosis of the stem of the left coronary artery in distal portion and occlusion of circumflex coronary artery (CX) and the second obtuse marginal branch (OM 2). During surgery no tumor was found within the right atrium, but right coronary artery giant aneurysm was revealed. The totally thrombosed aneurysm was removed with additional performance of two venous grafts to RCA and OM 2. The postoperative course was uneventful.

Coronary Aneurysm↗

PubMed2004

Myocardial revascularization for acute myocardial infarction.

UNLABELLED: Coronary artery bypass grafting (CABG) for acute myocardial infarction (AMI) is associated with increased morbidity and mortality compared with CABG in non-AMI patients. We describe the surgical results of these high-risk patients. Sixteen patients (nine male and seven female) underwent CABG after recent onset of acute myocardial infarction. The mean age was 64.7 (range: 51 to 78). Seven patients (43.8%) had at least one myocardial infarction in the past, three (18.8%)--diabetes mellitus, two (12.5%)--chronic renal failure after nephrectomy. Five patients (31.3%) were preoperatively in cardiogenic shock, and six patients (37.5%) required preoperative intraaortic balloon pump (IABP) for stabilization. Two patients (12.5%) had postinfarction ventricular septum perforation (VSD) and three patients (18.8%) hed left main artery trunk stenosis. Mean ejection fraction was 46%. During the first 24 hours six patients were operated, during the second day two, up to the seventh day five more and last three between 8th and 21st day after AMI. The operations were performed with extracorporal circulation in middle hypothermia (34 degrees C). The mean number of grafts per patient was 2.9, and the left internal thoracic artery was used in 11 patients (68.8%). In two patients VSD was closed with Dacron patch. All the patients needed longer time of reperfusion and inotropic drugs and eight (50%) of them mechanical support (IABP) during weaning from cardiopulmonary bypass. Three patients (18.8%) died (both with VSD) because of low output syndrome and multiorgan failure, all were over 70 years old (72, 73, 78). CONCLUSION: emergency coronary artery bypass grafting for acute myocardial infarction is associated with increased operative mortality and morbidity especially in the first 48 hours. The only risk factors for postoperative mortality in this group of patients are age over 70 years, cardiogenic shock, left main artery stenosis and the shortness of the interval between acute myocardial infarction onset and surgery.

Aged↗

PubMed2004

[Morphology of tick tarsus (Acari: Ixodida)--modifications connected with life cycle, behaviour, and habitat].

Ticks are ectoparasites of wide variety of vertebrates living in various types of environment all over the world. Morphological, biological, and physiological differences among tick species as well as among tick life stages are the result of tick adaptations to various life conditions. This paper presents morphological adaptations of tick tarsus to the hosts and the life conditions. The authors underline morphological differences of Haller's organ and pretarsus in four tick species: Argas reflexus (Fabricius, 1794), A. persicus (Oken, 1818), Dermacentor reticulatus (Fabricius, 1794), and Ixodes ricinus (Linnaeus, 1758).

Animals↗

PubMed2003

[The influence of prostaglandins on metastases development].

Arachidonic acid metabolites including prostaglandins (PG) participate in many biological processes and play regulatory functions. The significant role of PG in physiological and pathological process is well known and described by many authors. Prostaglandins were demonstrated to have local hormone properties and often exert an antagonist effect. Despite years of research the role of PG in cancer diseases development is still poorly understood. The article is focused on the influence of arachidonic acid metabolites and its analogs on tumor growth and metastases formation.

Humans↗

PubMed2002

Molsidomine potentiates the protective activity of GYKI 52466, a non-NMDA antagonist, MK-801, a non-competitive NMDA antagonist, and riluzole against electroconvulsions in mice.

The influence of molsidomine, a donor of nitric oxide (NO), L-arginine, a substrate for NO synthesis, and N(G)-nitro-L-arginine (NNA), an inhibitor of NO synthase, on the protective activity of CGP 40116, GYKI 52466, MK-801, and riluzole against electroconvulsions was studied in mice. Molsidomine (100 mg kg(-1); i.p.) potentiated the protective activity of GYKI 52466, MK-801, and riluzole but did not influence the protection offered by CGP 40116. In contrast to molsidomine, L-arginine (500 mg kg(-1); i.p.) did not impair the protective activity of any anticonvulsant. In a dose of 40 mg kg(-1), NNA administered i.p. did not affect the protection offered by any excitatory amino acid antagonists and riluzole. Combinations of molsidomine with either GYKI 52466 or MK-801 as well as riluzole did not cause a memory deficit in the passive avoidance task. However, the combined treatment of molsidomine with these anticonvulsants resulted in a motor impairment quantified by the chimney test. The lack of effect of L-arginine and NNA on the protective activity of excitatory amino acid antagonists suggests that molsidomine-evoked alterations in the protection provided by some excitatory amino acid antagonists against electroconvulsions are independent of the NO pathway.

Animals↗

PubMed2002

Functional annotation of proteomic sequences based on consensus of sequence and structural analysis.

To maximise the assignment of function of the proteins encoded by a genome and to aid the search for novel drug targets, there is an emerging need for sensitive methods of predicting protein function on a genome-wide basis. GeneAtlas is an automated, high-throughput pipeline for the prediction of protein structure and function using sequence similarity detection, homology modelling and fold recognition methods. GeneAtlas is described in detail here. To test GeneAtlas, a 'virtual' genome was used, a subset of PDB structures from the SCOP database, in which the functional relationships are known. GeneAtlas detects additional relationships by building 3D models in comparison with the sequence searching method PSI-BLAST. Functionally related proteins with sequence identity below the twilight zone can be recognised correctly.

Consensus Sequence↗

PubMedDate not supplied

Comparison of viability of B16 and Cl S91 cells in three cytotoxicity tests: cells counting, MTT and flow cytometry after cytostatic drug treatment.

In this study, results of three tests assessing viability of B16 and Cl S91 mouse melanoma cells after exposure to cytostatic drugs were compared: alive cell counting test after fixing with ethyl alcohol, MTT test and annexin V-FITC flow cytometry test. On the grounds of the obtained results the last mentioned method was recognized to be the most accurate and the least faulty. It was stated that mouse melanoma B16 cells are more sensitive to actinomycin D. cytosine arabinoside, cisplatin and dacarbazine than mouse melanoma Cl S91 cells. Mouse melanoma Cl S91 cells are more sensitive to vincristine than B16 cells.

Animals↗

PubMedDate not supplied

B16 and CLS91 mouse melanoma cells susceptibility to apoptosis after vincristin treatment in vitro.

Tumor cells' chemoresistance is related to the occurrence or lack of apoptosis. Considering the individual choice of cytostatic drugs for cancer patients and tumor cell resistance the research was undertaken. The viability of mouse melanoma B16 and ClS91 cells and apoptosis induction in vitro after treatment with vincristin was examined. In the future, this kind of study may play an important role in the efficient choice of drug dose and in limiting the side-effects in patients treated with vincristin. Determination of vincristin's influence on cell proliferation kinetics, cell cycle progression based on DNA content and percentage of apoptosis and necrosis in B16 and ClS91 cells, was the object of the present study. The number of viable B16 and ClS91 cells was estimated by flow cytometry analysis. Apoptotic cells were detected using the annexin V-FITC test. Flow cytometric measurement allowed for simultaneous quantitation analysis of four cell subpopulations in the investigated probes. The subpopulations were viable, apoptotic, secondary necrotic and necrotic cells. After adding vincristin into B16 and ClS91 cultures, it was revealed that about 94% ClS91 cells and 45% B16 cells died in the apoptotic way. ClS91 melanoma cells were more sensitive to vincristin treatment than the B16 cell line. The EC50 value for the B16 line was 39.8 microM and for ClS91 was 16.7 microM. Cell cycle was established on the basis of DNA cell content after staining cells with propidium iodide and analysed by flow cytometry. Vincristin induced both B16 and ClS91 cell lines arrest in G2/M cell cycle phase. It was found a correlation between apoptosis occurrence in the melanoma cells and vincristin resistance.

Animals↗

PubMedDate not supplied

Effect of adriblastin on viability, cell cycle and apoptosis in B16 and cloudman s91 mouse melanoma cells in vitro.

UNLABELLED: Recently, the oncologists have been increasingly interested in apoptosis. which is morphologically. biochemically and topographically different from necrosis. Apoptosis is probably a key point to understand the resistance of malignant cells to cytotoxic drug. The aim of this study was to determine the influence of adriblastin on morphology and kinetics of cell proliferation and evaluation of apoptosis and necrosis in B16 and Cl S91 mouse melanoma cells in vitro. Adriblastin induced morphological changes indicating occurrence of apoptosis and necrosis in B16 and Cl S91 mouse melanoma cells. The number of viable B16 and Cl S91 cells was estimated by flow cytometry analysis. Apoptotic cells were detected using the annexin V-FITC test. DNA content, after staining cells with propidium iodide, was analysed by flow cytometry. B16 cell line was more sensitive to adriblastin treatment than the CIS91 cell line. The adriblastin EC50, value estimated for the B16 line was 2.4 microM. while for Cl S91 line was 4.0 microM. It was revealed that about 59% Cl S91 cells and 65% B16 cells had died in the apoptotic way after adriblastin addition at EC50, concentration to B16 and Cl S91 cultures. Adriblastin induced cell arrest in G1 and S cell cycle phase in both B16 and Cl S91 cell lines. CONCLUSION: the new solutions to determinate cell chemosensitivity should be introduced into clinical practice.

Animals↗