Traumatic haemarthrosis of the knee -- indication to acute arthroscopy.

BACKGROUND AND AIMS: The most common mechanisms of the knee injuries are distortions and contusions. Fairly often they will result in hemarthrosis. The purpose of this study was to evaluate the findings in patients with acute traumatic hemarthrosis of the knee and based on these findings estimate the necessity of acute artroscopic examination with therapeutic procedure. MATERIAL AND METHODS: In the years 2007 and 2009 a total of 266 patients underwent acute arthroscopic examination in Department of Traumatology the Faculty Hospital Brno after the acute knee trauma. Patients with other intraarticular bone fractures were excluded. RESULTS: The ruptures of the ACL were the most common findings (52 %), meniscal tear (27 %), dislocation of the patella (11 %) and chondral or subchondral fractures were (13 %). In 224 (84 %) cases was performed artroscopic therapeutic procedure and in only 43 (16 %) case was performed routine arthroscopic examination. CONCLUSIONS: Based on our findings we believe that arthroscopic examination is necessary in patients with acute traumatic haemarthrosis of the knee and it is better methods like NMR examination because is provided to execute therapeutic procedure (Tab. 1, Fig. 2, Ref. 8). Full Text in PDF www.elis.sk.

On the use of biochemical markers in diagnostics of sudden cardiac death.

INTRODUCTION: Medical examiners frequently examine victims of sudden death. Most often sudden deaths have a cardiovascular cause. determine the diagnosis of sudden cardiac death based only on morphological findings may be often very difficult. Measurement of blood concentrations of cardiac troponin I (cTnl) and atrial natriuretic peptide (pro-ANP) is now in clinical use in adult patients with heart failure caused by myocardial damage. AIM: The aim of the study was the estimation wheather cTnl and/or pro-ANP could be markers of sudden cardiac death. PATIENTS AND METHODS: The study was carried out on 89 necroptic cases, of which 53 were concluded as cardiac-related sudden death, and 36 cases were used as a control group being other than cardiac death cases. Concentrations of markers were determined in blood taken from the left cardiac ventricle and from the right femoral vein. The dependence between the results of biochemical studies and death causes, results of histopathological examination of myocardium, time interval between the death and taking of samples, and resuscitation data was investigated. RESULTS: Concentrations of cTnl as determined in blood samples from the left ventricle were in most cases very high, largely exceeding the cut-off level, and so were concentrations of pro-ANP. The values of both parameters were significantly lower in peripheral blood. No statistically significant dependences were found between the levels of the studied markers and the cause of death, myocardial histopathological findings, time interval between the death and taking of samples, and resuscitation data. CONCLUSION: Based on the results obtained, the study can be concluded that blood is not a suitable medium for determination of biochemical markers of cardial troponin I and atrial natriuretic peptide for post-mortem diagnostics of myocardial damage and for determining the diagnosis of sudden cardiac death in a manner similar to diagnostics of myocardium damage in living patients.

Optical sensors based on spectroscopy of localized surface plasmons on metallic nanoparticles: sensitivity considerations.

Surface plasmon resonance (SPR) sensors use two types of surface plasmons: (i) propagating along a metal-dielectric interface and (ii) localized on metallic nano-objects. This article presents theoretical analysis of sensitivity of SPR sensors based on spectroscopy of localized surface plasmons on metallic nanoparticles. Analytical formulas inter-relating bulk and surface refractive index sensitivity with main design parameters are derived using the electrostatic approximation. The effect of particle diameter is accounted for by means of Mie theory. Figures of merit for SPR sensors using localized and propagating surface plasmons are calculated and compared. Although sensors based on spectroscopy of localized surface plasmons on gold spherical particles show promise for detection of processes occurring in the close proximity of the particle surface, their performance is still inferior to that of SPR sensors based on spectroscopy of propagating surface plasmons.

The redox state of glutathione in erythrocytes of individuals with Down syndrome.

BACKGROUND: The redox state of glutathione has been used as indicator for the redox environment of the cell. OBJECTIVES: To investigate relationships between the redox environments, the SOD activity, total antioxidant status and the oxidation stress markers production (MDA and lipofuscin). METHODS: Individuals with Down syndrome and age-matched healthy controls were enrolled into a study. Some parameters of oxidative stress in serum were determined: reduced glutathione, oxidized glutathione, redox potential of this couple (Eh), activity of superoxide dismutase in the red blood cells as well as malondialdehyde and lipofuscin. RESULTS: In the group of persons with DS statistically significant decrease in the GSH concentration was found, however, no differences in the GSSG concentration versus controls was observed. The redox potential values for couple GSH/GSSG are a statistically significantly increased in DS individuals compared to controls. CONCLUSION: In this study we highlighted the different ways of view at the role of GSH in metabolism of persons with DS. It is useful to look at the GSH and GSSG concentrations separately as well as at redox potential value, which influence total redox state of organism (Tab. 2, Fig. 3, Ref. 30) Full Text (Free, PDF) www.bmj.sk.

Sensitisation for cisplatin-induced apoptosis by isothiocyanate E-4IB leads to signalling pathways alterations.

A new synthetic isothiocyanate (ITC) derivative, ethyl 4-isothiocyanatobutanoate (E-4IB), appeared to be an effective modulator of cellular proliferation and potent inducer of apoptosis. In cooperation with cisplatin, this compound exerted synergistic effects in human ovarian carcinoma A2780 cells. In the present study we investigated in more detail E4IB-sensitisation for cisplatin-induced apoptosis. Sequential administration of both cytostatic agents led to increased intracellular platinum accumulation, glutathione level depletion and mitochondrial membrane potential dissipation. These events were accompanied with poly (ADP-ribosyl) polymerase cleavage, stimulation of caspase-3 activity, upregulation of p53, FasL and Gadd45alpha, cyclin B1 downregulation and an increase in mitogen-activated protein kinases JNK, ERK and p38 phosphorylation as well as PI3K level alterations. The presented results might have implications for developing new strategies aimed at therapeutic benefit of natural or synthetic ITCs in cooperation with various anticancer drugs.

The response of Na+/K+ -ATPase of human erythrocytes to green laser light treatment.

The objective of this study was to investigate the response of Na(+)/K(+)-ATPase of human erythrocytes to green laser irradiation. Effects of green laser light of fluences 9.5-63.3 J.cm(-2) and merocyanine 540-mediated laser light treatment were studied. Isolated erythrocyte membranes (protein concentration of 1 mg/ml) were irradiated by Nd:YAG laser (532 nm, 30 mW) and then incubated in a medium with 2 mM ATP for 30 min. Activity of ATPase was determined colorimetrically by measuring the colored reaction product of liberated inorganic phosphate and malachite green at 640 nm. Contribution of Na(+)/K(+)-ATPase to overall phosphate production was determined using ouabain. A positive effect of green laser light on Na(+)/K(+)-ATPase activity was observed. The dependence of enzymatically liberated inorganic phosphate on light fluence showed a linear correlation (R(2)=0.96, P=0.0005) for all fluences applied (9.5-63.3 J.cm(-2)). On the other hand, MC 540-mediated phototreatment caused a suppression of enzyme activity.

Influence of 2,5-dihydroxybenzylidene aminoguanidine on lipid oxidative damage and on antioxidant levels in model diabetes mellitus.

2,5-Dihydroxybenzylidene aminoguanidine (BAG) is a structural analogue of the antidiabetic compound aminoguanidine, and is an example of a substance protecting diabetic rats from lipoprotein oxidation arising in oxidative stress conditions characteristic of diabetes mellitus. We found that administration of BAG to diabetic rats decreases their susceptibility to lipoprotein oxidation, decreases formation of conjugated dienes and 4-hydroxy-2-nonenal, and increases antioxidant potential of plasma. On the other hand, our results show that BAG has a negative influence on lipoprotein oxidation in control rats. Increased formation of 4-hydroxy-2-nonenal and conjugated dienes and a decrease in plasma antioxidant potential was observed when BAG was administered to control rats. It is therefore necessary to search for other structural modifications of this substance that would combine higher antidiabetic activity with less toxicity in healthy individuals.

Influence of age on activities of antioxidant enzymes and lipid peroxidation products in erythrocytes and neutrophils of Down syndrome patients.

Thirty-seven individuals with Down syndrome (DS) were divided into four age categories: (i) 1 to < 6 years, (ii) 6 to < 13 years, (iii) 13 to < 20 years, and (iv) over 20 years. Activities of antioxidant enzymes found in individual age categories were different, but the differences between age groups were not statistically significant. We confirmed significantly higher activities of Cu/Zn superoxide dismutase (SOD) and glutathione peroxidase (GPx) in blood cells of people with DS as compared to 35 controls, which consisted, for the first time, of siblings of children with DS. No significant differences were found in activities of catalase and glutathione reductase in DS vs. controls. A significant difference was observed in serum concentration of malondialdehyde (MDA) in DS vs. controls (8.39 +/- 0.34 micromol/l vs. 7.34 +/- 0.27 micromol/l; p = .021) and concentration of MDA in erythrocytes of individuals with DS between the third and fourth age group (p = .05). In DS persons, an elevated ratio of SOD to catalase plus GPx with respect to the controls in all age categories was found, suggesting oxidative imbalance, potentially contributing to accelerated aging observed in these persons.

Combined effect of lipoic acid and doxorubicin in murine leukemia.

Our experiments indicate that administration of a toxic drug with high rate of free-radical formation (doxorubicin, DOX) combined with an antioxidant (alpha-lipoic acid, LA) may lead to a decrease in drug-toxicity. However, the effects of antioxidant may be concentration-dependent and it is therefore crucial to choose its appropriate dosage. LA at a low concentration (1 micromol/l) acts as a growth factor and at a higher concentration (100 micromol/l) acts as an antiproliferation agent. Both concentrations of LA in combination with DOX were examined in cytotoxic and antitumor effects in L1210 mouse leukemia cells employing a MTT chemosensitivity assay. In most concentration combinations, DOX and LA effect were antagonistic and synergistic action was only found at the higher concentration of both agents (DOX 2.5 micromol/l and LA 100 micromol/l). Use of LA in doxorubicin therapy lead to an increase (though marginally significant) in survival of animals. Combined single-dose administration of DOX (5 mg/kg) and LA (16 mg/kg) lead to super-additive effect of the combination on survival of leukemic mice.

Binding of pyrene isothiocyanate to the E1ATP site makes the H4-H5 cytoplasmic loop of Na+/K+-ATPase rigid.

1-Pyreneisothiocyanate was shown to be an inhibitor of Na+/K+-ATPase. Reverse-phase HPLC and activity studies indicated binding of 1-pyreneisothiocyanate at the H4-H5 loop of the alpha subunit and competition with the fluorescein 5'-isothiocyanate for the E1ATP site. While fluorescein 5'-isothiocyanate, the fluorescent ATP pseudo-analog, was shown to be immobilized at the E1ATP site, there was no possibility to draw any conclusion about the flexibility of the E1ATP site due to its short lifetime. Employing 1-pyreneisothiocyanate as a long-lived fluorophore and a label for the E1ATP site, we found that the ATP-binding site of Na+/K+-ATPase and, in fact, the whole large intracellularly exposed H4-H5 loop of the catalytic alpha subunit is rigid and rotationally immobilized. This has important consequences for the molecular mechanism of the transport function.

Modifications induced by insulin-dependent diabetes mellitus on human placental Na+/K+-adenosine triphosphatase.

The causes of the reduced activity of Na+/K+-adenosine triphosphatase (ATPase) in human diabetes are still the object of controversy. The aim of this work was to investigate the mechanisms of inhibition by means of the study of the Na+/K+-ATPase purified from human placenta. We purified Na+/K+-ATPase from term placentas of six healthy women and six age-matched women with insulin-dependent diabetes mellitus (IDDM) in good metabolic control. The enzymatic activity was reduced in both the microsomal fraction and the purified Na+/K+-ATPase obtained from diabetic women, whereas no difference was found in the number of active molecules determined by anthroyl ouabain binding. The Na+/K+-ATPase purified from women with IDDM did not show any modification in the ouabain affinity or changes in the physicochemical structure of the ouabain binding site investigated by dynamic fluorescence or alterations in lateral diffusion. The activation energy of the enzyme was increased, whereas the tryptophan accessibility of the enzyme was lower in women with IDDM. The fluidity of the lipid anulus of the enzyme was higher in women with IDDM than in control women, as suggested by fluorescence polarization of 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene. The adenosine triphosphate-binding site, investigated by anisotropy decay studies of the fluorescent probe pyrene isothiocyanate, was modified in women with IDDM. It appears that the Na+/K+-ATPase of human placenta is altered in its disposition in IDDM.

Possible nystatin-protein interaction in yeast plasma membrane vesicles in the presence of ergosterol. A Förster energy transfer study.

The Förster energy transfer from tryptophan residues of membrane proteins to nystatin was measured in reconstituted yeast plasma membrane vesicles free of, or doped with, ergosterol. We wanted to elucidate whether the functional change of membrane transport proteins from H+ symporters to facilitators, observed in ergosterol-containing plasma membrane vesicles on addition of nystatin [Opekarová and Tanner (1994) FEBS Lett. 350, 46-50], is reflected in altered protein-nystatin relations within the membrane. Both frequency-domain and time-domain time-resolved fluorescence spectroscopy showed that in the presence of ergosterol nystatin is located much closer to membrane proteins than in its absence.

Night and day differences in the food-intake of laboratory rats Wistar and Koletsky strains.

BACKGROUND: Rats have an extraordinary expressive circadian organization and prefer the dark as the optimal condition of its life environment. During darkness, the rhythm of its several parameters reaches the acrophase. MAIN PURPOSE: The aim was to establish the differences in the level of food-intake of laboratory rats of the Wistar strain and in those of the spontaneously obese rats of the Koletsky strain by means of ad libitum feeding under natural light-dark conditions. METHODS: The levels of day and night food consumptions in both strains of rats, Wistar and the spontaneously obese Koletsky strain, were studied within the period from January 10th to 20th, (males), and from April 16 to 26, 1990, (females). The animals were fed by Larsen's diet under natural light conditions. The data were evaluated by means of the t-test. RESULTS: It was detected that during the period between 5 o'clock PM and 6 o'clock AM the male rats of the Wistar strain consumed 80% and the female rats 79% of their total daily amount of food. Food consumption of the Koletsky rats during the period from 5 o'clock PM to 6 o'clock AM in males reached the value of 72% and in females 74%. CONCLUSIONS: There were detected significant differences in circadian food-intake in both strains. Besides the nocturnal preference in food-intake of Wistar rats, which is in accordance with the data gained from literature, a similar food-intake with expressive diurnal-nocturnal differences exists also in the spontaneously obese Koletsky rats. Daily food consumption in these male rats was significantly higher when compared to the Wistar strain. (Tab. 1, Fig. 1, Ref. 5.).

The transmembrane gradient of the dielectric constant influences the DPH lifetime distribution.

The fluorescence lifetime distribution of 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH) in egg-phosphatidylcholine liposomes was measured in normal and heavy water. The lower dielectric constant (by approximately 12%) of heavy water compared with normal water was employed to provide direct evidence that the drop of the dielectric constant along the membrane normal shifts the centers of the distribution of both DPH and TMA-DPH to higher values and sharpens the widths of the distribution. The profile of the dielectric constant along the membrane normal was not found to be a linear gradient (in contrast to [1]) but a more complex function. Presence of cholesterol in liposomes further shifted the center of the distributions to higher value and sharpened them. In addition, it resulted in a more gradient-like profile of the dielectric constant (i.e. linearization) along the normal of the membrane. The effect of the change of dielectric constant on the membrane proteins is discussed.

Lateral mobility of plasma membrane proteins in dividing eggs of the loach (Misgurnus fossilis): Regional differences and changes during the cell cycle.

Regional differences in lateral diffusion rates of fluorescence-labeled proteins have been studied in the plasma membrane of dividing eggs of the loach (Misgurnus fossilis) by fluorescence recovery after photobleaching (FRAP). Apparent animal-vegetal differences in fluorescence intensity, lateral diffusion coefficients, and fractions of mobile proteins have been found, with all these quantities being higher in the animal pole region than in the yolk region. Cyclic changes in protein diffusion coefficients and mobile fractions during the first few cell cycles have also been recorded. Soon after the end of a cleavage, the diffusion coefficient reaches its minimal value and increases rapidly before the next cleavage.

Comparison of 9-aminoacridine and atebrine induced changes in optical, electrical and mechanical characteristics of lipid bilayers.

The effects of fluorescent probes 9-aminoacridine (9AA) and atebrine (AT) on physical properties of liposomes and planar bilayer lipid membranes (BLM) were studied. The method of fluorescence spectroscopy and the electrostriction method based on measurement of higher current harmonics were used. At low concentrations (10(-5)-5 x 10(-5) mol/l), 9AA increased fluorescence intensity, while in liposomes from soybean phosphatidylcholine fluorescence quenching occurred at higher probe concentration. Fluorescence quenching occurred over the entire concentration range tested (10(-5)-10(-4) mol/l) in liposomes made from a mixture of egg phosphatidylcholine and cardiolipin. In contrast to 9AA, AT, thanks to its hydrophobic chain, penetrates deeper into the hydrophobic membrane moiety; thus, immobilization of the molecule and an increase in fluorescence intensity was always observed. Probes adsorbed to membranes, leaving their electric capacitance effectively unchanged. Adsorption of charged dye particles induced small changes in transmembrane potential. In the presence of 10(-5) mol/l AT, the modulus of elasticity E perpendicular increased somewhat for soft membranes (E perpendicular approximately 2.5 x 10(7) Pa), whereas it decreased for hard membranes (E perpendicular approximately 5 x 10(7) Pa). pH gradient present on the membrane affected the ability of the dyes to incorporate into the membranes. Our results provide evidence against the proposed model of the quenching mechanism introduced by Rottenberg and Lee (1975).

Model of distribution of anticancer agents transplanted into the brain tissue using the random walk method.

A Monte-Carlo approach to analysis of dispersion in the tissue of a locally administered drug is presented. The distribution of a drug in the tissue is simulated as a distribution of randomly walking particles. The approach is demonstrated on a simple situation for which both experimental results and an analytical solution are known. The approach can be used in situations, where common numeric methods are difficult to use, especially for analyses of drug transport in an inhomogeneous space, and problems with complex boundary conditions, e.g. in analyses of dispersion of anticancer agents locally applied into tumours.