The concentration of thiobarbituric acid reactive substances (TBARS) and paraoxonase activity in blood of patients with osteoarthrosis after endoprosthesis implantation

Background

The aim of this study was to evaluate the concentration of malondialdehyde (MDA) in erythrocytes and in blood plasma and the activity of blood paraoxonase (PON1) of patients with osteoarthrosis (OA) submitted to endoprosthesis implantation for evaluating oxidative stress.

Material/Methods

Study was conducted on 55 patients with OA and on 54 total movement-efficient volunteers. The material for the study was venous blood plasma, serum and erythrocytes.

Results

Increased concentration of MDAe before surgery was observed in the group of men and in patients with a degenerative process affecting hip joints. After an implantation of endoprosthesis, MDAe decreased to the level observed in the control groups. In the study group MDA concentration in plasma was slightly lower before surgery, and after an operation it reached the value of the parameter of the reference groups. Regardless of sex or age, paraoxonase activity was almost twice as high in almost all subgroups as in the reference group. A positive correlation between PON 1 activity and MDAe concentration was demonstrated both before and after surgery in the group of men.

Conclusions

The increase of PON1 activity in patients’ serum in relation to the control groups indicates a probable pathogenic role of the increased formation of reactive oxygen species in the course of OA and may suggest acute inflammation of the synovial joint. The high level of PON 1 activity after endoprosthesis implantation indicates that surgical treatment may additionally stimulate ROS generation. MDAe concentration indicate more intensive process of lipid peroxidation in the elderly.

Lack of changes in the concentration of thiobarbituric acid-reactive substances (TBARS) and in the activities of erythrocyte antioxidant enzymes in alcohol-dependent patients after detoxification

BACKGROUND

Chronic alcohol consumption induces an increase in oxidative stress. There are studies that indicate changes in the activity of antioxidant enzymes and the concentration of lipid peroxidation products in the blood of organisms as a result of alcohol consumption, but published results are somewhat conflicting. The aim was to study the effect of alcohol withdrawal and detoxification on the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) in erythrocytes and on the concentration of thiobarbituric acid-reactive substances (TBARS) in the erythrocytes and blood plasma of alcohol-dependent patients.

MATERIAL/METHODS

The study group consisted of 42 alcohol-dependent men who underwent seven-day detoxification at an addiction treatment department. The control group consisted of 20 healthy male volunteers. Blood for analysis was taken from the antecubital vein before detoxification, after the first detoxification, and after several (> or =3) detoxifications.

RESULTS

Before detoxification, the concentration of TBARS in the men's blood plasma was 40% higher (p<0.001) than in the control group. After detoxification, the concentration of TBARS decreased, but remained higher than in the control group. The activities of SOD and GPx in erythrocytes of alcohol-dependent persons were statistically significantly lower than in the control group both before and after detoxification. However, after detoxification, a slight increase in the activity of SOD was observed compared to that before detoxification.

CONCLUSIONS

This study confirms that alcohol-dependency leads to oxidative stress in the peripheral blood. Seven-day alcohol withdrawal and detoxification has no effect on TBARS concentration and antioxidant enzyme activity.

Cell cycle, melanin contents and apoptosis processes in B16 and Cloudman S91 mouse melanoma cells after exposure to cytostatic drugs

Free radicals are generated in cells during many metabolic processes and eliminated from an organism by complex enzymatic and nonenzymatic systems. Many chemical compounds--among others melanin, reveal antioxidative properties. In this work the influence of some cytostatic drugs (at EC50) on melanin content and on the apoptotic processes in mouse melanoma B16 and Cloudman S91 cells in vitro were investigated. The cells were incubated with adriblastin, actinomycin D, cytosine arabinoside, cisplatin, dacarbazine and vincristine. The number of viable mouse melanoma B16 and Cloudman S91 cells was estimated by flow cytometry analysis and melanin content in colorimetric assays. Apoptotic cells were detected using the annexin V-FITC test. The majority of tested cytostatic drugs caused an increase of melanin content in the cells of both melanoma lines, except cisplatin and dacarbazine in the case of B16 cells and dacarbazine in the case of Cloudman S91. Adriblastin, actinomycin D and vincristine evoked apoptosis in the both tested cell lines. Slight increase of melanin content in melanoma cells can be a cell answer to free radicals generation by some cytostatic drugs like adriblastin, actinomycin D and vincristine.

Lack of local anesthetic properties of lidocaine gel in an experimental model

INTRODUCTION

Many reports negate the anesthetic properties of lidocaine gel placed in the urethra during catheterization. The anesthetic action of lidocaine is inseparably associated with the toxic action of this compound on cells.

MATERIALS AND METHODS

A primary rabbit urothelial cell culture (PRUCC) was previously established as a monolayer. The effect of 2% lidocaine gel on the viability of the PRUCC was assessed and compared with the cytotoxic effect of decreasing concentrations of lidocaine solution. Cell viability was evaluated after 1-hour exposure using the trypan blue exclusion test.

RESULTS

The 2% lidocaine gel did not show cytotoxic properties after 1 h of incubation on a PRUCC. The 2 and 1% lidocaine solutions induced statistically significant decreases in the viability of the PRUCC after 1 h of incubation.

CONCLUSIONS

Experimental tests evaluating the cytotoxicity of local anesthetics may prove to be an objective measure of the accessibility of these substances to cells and their anesthetic action.

[Changes in arylsulphatase activity in blood serum in patients with breast cancer before and after treatment]

We evaluated arylsulphatase activity in 52 women with breast cancer. In women with breast cancer this enzyme activity is 2,5-fold higher than in healthy women. After operation and chemiotherapy arylsulphatase activity decreased to normal values. There is correlation between enzyme activity and tumor size and number of metastases. In group with bigger tumor and higher number of metastases arylsulphatase activity is markedly higher.

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.

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.