Magnetized plasma implosion in a snail target driven by a moderate-intensity laser pulse.

Optical generation of compact magnetized plasma structures is studied in the moderate intensity domain. A sub-ns laser beam irradiated snail-shaped targets with the intensity of about 1016 W/cm2. With a neat optical diagnostics, a sub-megagauss magnetized plasmoid is traced inside the target. On the observed hydrodynamic time scale, the hot plasma formation achieves a theta-pinch-like density and magnetic field distribution, which implodes into the target interior. This simple and elegant plasma magnetization scheme in the moderate-intensity domain is of particular interest for fundamental astrophysical-related studies and for development of future technologies.

Synchronizing single-shot high-energy iodine photodissociation laser PALS and high-repetition-rate femtosecond Ti:sapphire laser system.

A system of precise pulse synchronization between a single-shot large-scale laser exploiting an acousto-optical modulator and a femtosecond high repetition rate laser is reported in this article. This opto-electronical system has been developed for synchronization of the sub-nanosecond kJ-class iodine photodissociation laser system (Prague Asterix Laser System-PALS) with the femtosecond 25-TW Ti:sapphire (Ti:Sa) laser operating at a repetition rate 1 kHz or 10 Hz depending on the required energy level of output pulses. At 1 kHz synchronization regime, a single femtosecond pulse of duration about 45 fs and a small energy less than 1 mJ are exploited as a probe beam for irradiation of a three-frame interferometer, while at 10 Hz repetition rate a single femtosecond pulse with higher energy about 7-10 mJ is exploited as a probe beam for irradiation of a two-channel polaro-interferometer. The synchronization accuracy ±100 ps between the PALS and the Ti:Sa laser pulses has been achieved in both regimes of synchronization. The femtosecond interferograms of laser-produced plasmas obtained by the three-frame interferometer and the femtosecond polarimetric images obtained by the two-frame polaro-interferometer confirm the full usefulness and correct functionality of the proposed method of synchronization.

Gender differences in tumor necrosis factor alpha and leptin secretion from subcutaneous and visceral fat tissue.

Tumor necrosis factor alpha (TNFalpha) and leptin concentrations were determined in the abdominal subcutaneous and visceral (omental) adipose tissue of patients undergoing elective open-abdominal surgery and compared with their body mass index. The concentration of leptin did not differ significantly between women and men, being high in subcutaneous fat tissue and low in visceral fat tissue. TNFalpha concentration in subcutaneous fat tissue was approximately the same in both genders, but it was significantly lower in visceral fat tissue of women and unchanged in visceral fat tissue of men. A significant correlation between BMI and leptin was found in the two fat tissue compartments of both genders, but the correlation between BMI and TNFalpha was found only in subcutaneous fat tissue of women.

[PPARs: the role in glucose and lipid homeostasis, insulin resistance and atherosclerosis]. / PPAR: úloha v homeostáze glukózy a lipidu, v inzulínové rezistenci a v ateroskleróze.

This review deals with general mechanisms of peroxisome proliferator-activated receptors (PPARs) functions, describes the mode of action of various PPAR subtypes in different tissues and their participation in transcription of genes governing lipid and glucose homeostasis. The hypothetic role of free fatty acids in mediating metabolic effects of PPARs, their role in insulin resistance and genetic studies highlighting the ligand-independent activation and post-translational modification of PPARgamma are disscussed in details. A possible role for PPARs in atherosclerosis, especially in connection with macrophage function in this process, is also explained.

[Tumor necrosis factor alfa (TNFalpha) and insulin resistance]. / Tumor nekrotický faktor alfa (TNFalpha) a inzulinová rezistence.

Obesity and diabetes mellitus type 2 belong among the most frequent illnesses and are categorized among the dominant risk factors for cardiovascular disease in all developed countries. There is a causal relation between insulin resistance and the origin of these risk factors of the cardiovascular morbidity and mortality. Numerous studies have attemted to identify the mechanisms linking obesity with insulin resistance and type 2 diabetes. Numbers of factors have been suggested as having a role in pathogenesis of obesity-related insulin resistance. One of these factors is tumor necrosis factor alfa (TNFalpha).

Serum leptin and leptin receptors in healthy prepubertal children: relations to insulin resistance and lipid parameters, body mass index (BMI), tumor necrosis factor alpha (TNF alpha), heart fatty acid binding protein (hFABP), and IgG anticardiolipin (ACL-IgG).

In a group of randomly selected 29 healthy prepubertal children (16 boys, mean age 9.56 +/- 0.7 years, 13 girls, mean age 9.96 +/- 0.9 years) fasting serum leptin and leptin receptor concentrations were measured by ELISA and compared with insulin parameters (homeostatic model of assessment insulin resistance = HOMA IR, insulin, intact proinsulin, C-peptide) and some metabolic parameters and factors that contribute to insulin resistance: triacylglycerols, high density lipoprotein cholesterol (HDL cholesterol), low density lipoprotein cholesterol, body mass index, tumor necrosis factor, heart fatty acid binding protein, and IgG fraction of anticardiolipin. Statistical analysis was performed using SAS/STAT software and included analysis of normality, analysis of variance, Spearman's correlations, linear and multiple regression analysis with insulin parameters as dependent variables. The subgroups of boys and girls did not differ significantly in any of parameters studied. Serum concentrations of insulin, intact proinsulin, HOMA IR, C-peptide and triacylglycerols appeared to be primarily influenced by serum leptin concentration. Serum leptin concentrations were tightly correlated with body mass indexes and negatively correlated with leptin receptor concentrations, probably as a manifestation of down regulation. The role of other factors studied appeared to be complementary or less significant (hFABP, ACL IgG), or absent (TNF alpha). We concluded that in healthy prepubertal children of both genders serum leptin concentration contributes to insulin resistance and to insulin resistance-related metabolic changes.

[Leptin in persons with simple obesity]. / Leptin u osob s prostou obezitou.

Obesity is a disease with distinct genetic determination and its phenotype is defined by the still unknown number of genes whose expression can be influenced by environmental factors. Several years ago, "obesity gene" was isolated in animals. This gene, coding protein which consists of 165 amino acids, is called leptin. Leptin is supposed to be a key substance controlling homeostasis of body weight and energy balance; it is produced by adipocytes and its value correlates highly significantly with anthropometric parameters that characterize physical constitution and amount of subcutaneous fatty tissue. The obese individuals often display hyperleptinemia which is frequently caused by a postreceptor disorder; sporadically, a different leptin structure or hypoleptinemia (caused by genetic anomaly) are reported. It is supposed that either absolute or relative leptin deficiency in obese persons are associated with causal obesity (e.g. appetite stimulation). Leptinemia values correlate with percentage of subcutaneous fatty tissue, insulinemia and sometimes with glycemia. In our study we examined 200 probands, patients of the Metabolic and Diabetologic Out-Patient Department, Hospital in Sternberk. A very close correlation between the amount of subcutaneous fatty tissue (measured by a caliper in 10 skinfolds) and the leptine serum concentration was found. The values of leptinemia in men of normal constitution ranged within 1-11 ng/ml, non-obese women had 3-4 times higher values. Leptinemia in some obese individuals reached up to 70 ng/ml. However, the currently calculated and reported parameters of physical constitution (BMI, WHR, Grant index) did not correlate significantly with leptinemia. Similarly, biochemical parameters considered as general markers of insulin resistance (often associated with obesity) did not correlate significantly with leptinemia. This finding indicates that some calculated parameters, quantifying and gualifying physical constitution, may be ambiguous and leptinemia was found to give more detailed information about the amount of subcutaneous fatty tissue than WHR or BMI. An accidental finding was an important positive correlation between myoglobin concentration and creatinemia. At monitoring the effect of hypolipidemic agents we use the myoglobin examination and therefore we consider this correlation to be very important and every physician performing this analysis should be informed about it. The present study thus confirmed that a more accurate quantification of subcutaneous fatty tissue is required. On the other hand, we believe that examination of leptinemia can contribute significantly to stratification of patients into risk groups (with respect to clinical, economic and time differentiation) and subsequently to the treatment of these patients. In future, criteria for quantification of leptinemia and leptine resistance should be defined precisely.

[Personal experience in the diagnosis and monitoring of therapy in metabolic disorders with risk of crystallization in patients with recurrent urolithiasis]. / Nase zkusenosti s diagnostikou a monitorováním lécby metabolických poruch a rizik krystalizace u pacientu s recidivující urolitiázou.

A ten-year experience with diagnosis and therapy of metabolic abnormalities and crystallization risks in patients with recurrent urolithiasis is presented. Since 1985, more than 900 persons with recurrent urolithiasis have been examined at the Metabolic Centre of the Hospital in Sternberk. The patients were examined routinely at ambulance or during hospitalization; the examination consisted of repeated urine and blood collections after the diet with various content of calcium and salt. All initial data (case history, physical finding, biochemistry, radiodiagnostics) were processed by a semi-expert computing program SOFT which was also used for monitoring of the therapy. Then the patients were divided into individual risk groups (Pak). Of all probands, the group of 130 patients (satisfying the strict criteria of the study) was selected and the data obtained was processed statistically. The group of 130 patients with recurrent urolithiasis (all of them were drug-treated) was compared to the group of 50 individuals with urolithiasis treated by diet and regimen measures. The patients given drugs showed a significantly increased crystallization inhibitors concentration in urine and reduced crystallization promotors, or relative saturation of some lithiatic substances. The paper analyzes the effect of the mostly administered drugs on crystallization risks and some less known "metabolic" indications of application of some drugs are recommended. It is concluded that the dietary, drinking and regime measures are basic for a good therapy of patients with urolithiasis, but patients with recurrent urolithiasis should be applied a selective metaphylaxis of drugs after routine metabolic examination. This finding is supported by a low number of recurrent urolithiasis.

[Use of etofyllinclofibrate (Duolip Forte) in combined hyperlipidemia]. / Zkusenosti s aplikací etofylinklofibrátu (Duolip forte) u kombinovaných hyperlipidémií.

BACKGROUND: Duolip forte (ethophyllinclofibrate) is a lipid lowering drug, the effect of which was not yet adequately verified in our conditions, namely from the point of its effect on various types of hyperlipoproteinaemias. METHOD AND RESULTS: The therapy was applied on 45 patients with combined hyperlipidaemia, 25 men and 20 women, mean age 53.8 years (age range 41-65). About one half of patients were treated for hypertension, almost one quart of them manifested ischemic heart disease, 13% had a history of myocardial infarction and the same percentage suffered from associated diabetes type 2. Duolip forte was administered perorally in a dose of 500 mg once daily for 12-16 weeks to the patients who had complied with the prescribed diet (weight loss, improvement of lipid levels) during three-month preliminary period, but did not reach desirable parameters. After the therapy, the whole group studied manifested a significant decrease of total cholesterol (-10.8%), LDL-cholesterol (-13%), triglycerides (-40.8%) and free fatty acids (-20.6%), while the increase of HDL-cholesterol and its fractions was not significant. In hyperlipoproteinaemias of IIa type (n = 15), only a significant decrease of LDL-cholesterol appeared, in hyperlipoproteinaemias of IIb type (n = 15), a significant decrease was evidenced only in triglycerides (-33.9%). In hyperlipoproteineaemias of IV type (n = 15), a significant decrease was observed in triglycerides (-50.3%), while HDL-2 cholesterol values increased (+32.3%). A slight decrease of uric acid level and of body mass index observed in all groups was statistically not significant, as well as a slight increase of glycaemia and changes of serum transaminases. No unwanted side effects of Duolip were found. CONCLUSIONS: Ethophyllinclofibrate has proved as effective namely at hypertriglyceridemic primary hyperlipidaemias. Besides decreasing triglycerides, it increases significantly HDL-2 cholesterol. A convenient dosage, small lithogenic effect and minimum of side effects make it a drug of choice for some groups of elderly high-risk patients.

Serum lipoprotein fatty acid patterns in various types of familiar combined hyperlipidemia.

The relative content of various fatty acids in serum lipoproteins was determined in patients with type IIa (38), IIb (49) and IV (77) of hyperlipoproteinemia and compared with 52 controls. Significant changes were found in hyperlipoproteinemia associated with hypertriglyceridemia (type IV) but not in "pure" hypercholesterolemia (type IIa). In all lipoprotein fractions (VLDL, LDL, HDL) in type IV of hyperlipoproteinemia the increased oleic and linolenic acid proportions were found, while proportions of linoleic, arachidonic and docosahexaenoic acids were decreased. The saturated fatty acids (myristic, palmitic and stearic) were found increased in LDL. Linear regression analysis has shown positive correlation between the content of arachidonic and docosahexaenoic acids in HDL and LDL and the serum levels of total HDL-cholesterol, HDL2-cholesterol, HDL3-cholesterol and ApoA1, while a negative correlation between these fatty acids and serum triglycerides level appeared. These findings can be explained partly by increased content of triglycerides and free fatty acids in lipoproteins. Possible differences concerning mechanisms of accelaration of atherogenesis in various types of hyperlipidemia are discussed.

Unsaturated fatty acids incorporated in HDL in hypo- and hyperalphalipoproteinemia--relation to the HDL-cholesterol level.

Proportions of unsaturated fatty acids of high density lipoprotein (HDL) lipids and their relationships to the HDL-cholesterol level were compared in hypo- and hyperalphalipoproteinemic subjects. Both groups did not differ in the level of serum cholesterol. However, hypoalphalipoproteinemia was associated with hypertriglyceridemia, higher HDL-triacylglycerol level, and higher proportion of HDL-18:1 (oleic acid) and lower proportions of HDL-18:2 (linoleic acid) and 20:4 (arachidonic acid) than hyperalphalipoproteinemia. The HDL-20:4 was the only fatty acid correlating (negatively) with HDL-cholesterol. However, HDL-18:1 correlated positively and HDL-18:2 negatively with HDL-triacylglycerols, lipids related to the fall of HDL-cholesterol. These results suggest 1) an antagonism of 20:4 and 18:2 as structural components of HDL lipids in relation to the HDL-cholesterol level, and 2) an association of replacement of HDL 18:2 by 18:1 with the disorder of plasma triacylglycerol metabolism.

Fatty acids in lipids of nasoethmoidal polyps.

In 29 samples of recurrent nasoethmoidal polyps removed from 11 patients, the relative fatty acids composition was established by means of gas chromatography. Four samples of nasal mucosa of patients without polyps were subjected to the same procedure. A significant increase in the content of linoleic acid (18:2, n-6) as well as in the index "linoleic acid/oleic acid" was found. Proportion of arachidonic acid was high both in polyps and in control samples of nasal mucosa. An orientation examination of fatty acids in individual fractions of lipids, compared to serum values, showed that the main source of arachidonic acid appears to be phospholipids.