Klíšťata sají obrovské množství krve, která je jejich jediným zdrojem živin a energie. Přesný enzymatický mechanismus zpracování krve ve střevě klíšťat však kupodivu nebyl donedávna vůbec znám. Náš komplexní molekulární model trávení hostitelského hemoglobinu u klíštěte obecného (Ixodes ricinus) poprvé odhalil analogii enzymatického aparátu s krevsajícími ploštěnci a hlísticemi, a zároveň tato znalost představuje zásadní poznatek pro účinný boj s klíšťaty a jimi přenášenými patogeny., Ticks (in this case Ixodidae and Argasidae) feed on enormous amounts of host blood, which provides their ultimate source of energy and nutrients. There has been only limited evidence on the exact molecular mechanisms of blood digestion in ticks. For the first time, our complex enzymatic model of proteolytic digestion in the Common Tick (Ixodes ricinus) reveals the analogy of tick intestinal proteolysis with bloodfeeding platyhelminthes and nematodes and presents a future application potential in tick or tick-borne pathogen interventions., and Daniel Sojka.
The aim of this study was to find the principal parameters of surface tension of the blood and verify its possible correlation with some of the commonly assessed laboratory indicators that are affected by diseases with the expected possible changes in the surface tension of the blood. The surface tension of the blood was assessed in 150 patients. At the same time, the basic biochemical and hematological parameters were determined in these patients. The results have shown a close correlation between the surface blood tension and the activity of plasma gamma-glutamyltransferase. We assume that this relationship is based on the changes in concentration of bile acids in the blood during liver or bile duct afflictions., A. Kratochvíl, E. Hrnčíř., and Obsahuje bibliografii
Nitric oxide generated from L-arginine is a messenger for cell- to-cell communication. Abnormalities in nitric oxide release have been implicated in diseases ranging from hypertension and atherosclerosis to septic shock and rheumatoid arthritis. We report here the in vivo and in vitro measurements of nitric oxide in the cardiovascular system using a porphyrinic sensor specific for NO. The sensor has a detection limit 10“9 M, response time of 0.1-10 ms and diameter of 1-20 fi m. Protected by an intravenous catheter or Swan-Ganz catheter, the sensor can be implanted into tissues as well as into the blood stream. Nitric oxide concentrations were measured directly in the heart and also in veins and arteries, ranging in diameter from 100 nm to 5 mm. Nitric oxide production was induced by the action of different physical agents (shear stress, stretching) as well as various chemical substances agonists (bradykinin, acetylcholine, ATP).
Quinidine-like immunoreactivity (Abbott TDx Quinidine fluorescence polarization immunoassay) was measured in blood serum of control rats and rats exposed to hypoxia in a hypobaric chamber (7 500 m for one hour). The mean "quinidine" levels (mean±S.D.) were 0.159±0.058 and 0.260±0.110 («mol quinidinq/1 serum), respectively (p<0.01).
The effects of acute exposure to cadmium (Cd) on the blood antioxidant defense system, lipid peroxide concentration and hematological parameters, as well as the possible protective role of vitamin E were studied. Male Wistar albino rats (3 months old) were treated with cadmium (0.4 mg Cd/kg b.m., i.p., 24 h before the experiment) or with vitamin E + Cd (20 IU Vit E/kg b.m., i.m., 48 h + 0.4 mg Cd/kg b.m., i.p., 24 h before the experiment). The hematological parameters were assessed: red blood cell counts, hematocrit value and hemoglobin concentration were significantly decreased in the blood of Cd-treated rats. Intoxication with cadmium was also followed by significantly increased lipid peroxide concentrations. We also observed increased activity of antioxidant defense enzymes: copper zinc containing superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase as well as concentrations of non-enzymatic components of antioxidant defense system: reduced glutathione, vitamin C and vitamin E. Pretreatment with vitamin E exhibited a protective role on the toxic effects of cadmium on the hematological values, lipid peroxide concentration as well as on enzymatic and non-enzymatic components of antioxidant defense system., B. I. Ognjanović, S. Z. Pavlović, S. D. Maletić, R. V. Žikić, A. Š. Štajn, R. M. Radojičić, Z. S. Saičić, V. M. Petrović., and Obsahuje bibliografii
Steroids are important marker s in pregnancy. Although estimating their levels separately in umbilical arterial (UA) and venous blood (UV) enable more precise insights into the functioning fetoplacental unit compared to using mixed umbilical blood (UM), selective aspiration of UA and UV is technically more demanding than collecting UM. We measured the levels of 67 unconjugated steroids and steroid polar conjugates in UA and UV using GC-MS in 80 women giving birth within weeks 28 to 42 of gestation. The samples were sorted into three groups: women entering labor within weeks 28- 32 (group A, n=19), weeks 33-37 (group B, n=19), and weeks 38-42 (group C, n=42) of gestation, respectively. The preterm labo rs were due to pathologies unrelated to steroid status. Most unconjugated steroids exhibited pronounced arteriovenous differences (AVD). The AVD were less distinct in more stable steroid conjugates. Most steroids positively correlate with gestational age, but unconjugated 5 β -reduced pregnanes show negative correlations, as do testosterone and androstenediol, substrates for the placental synthesis of estrogens. Tight correlations be tween steroids in UA and UV indicate that steroid measurements in UA, UV and UM can be accurately derived from each other, which is important for the diagnostics of steroid related diseases in newborns., A. Pašková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The administration of creatine (5 g/day for one month) to 11 young active sportsmen affected their urinary excretion of creatine, creatinine, and thiodiglycolic acid (TDGA) as well as blood levels of homocysteine, vitamin B12 and folates. The probands were divided into four groups, according to the amount of creatine found in urine, and of folates and vitamin B12 determined in blood. The changes of folates and vitamin B12 were mutually reciprocal. Each group utilized CR as donor of one- and two-carbon (1C and 2C) units by means of homocysteine (HoCySH), folates, and vitamin B12, in different metabolic pathways. In 10 men the creatine administration was accompanied by an increase of HoCySH level in blood, while in the last man, with accidentally discovered hyperhomocysteinemia, the HoCySH level dropped by 50 %. Differences between initial and terminal TDGA levels indicate that creatine affects equilibria of redox processes. Creatinine excretion into urine changed in the dependence on the extent of metabolic disturbances., T. Navrátil ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy