Here we report the case of a 31-year-old man admitted to our hospital with echocardiografic and Cardiac Magnetic Resonance signs of myocarditis complicated by ventricular tachycardia, initially resolved with direct current shock. After the recurrence of ventricular tachycardia the patient was submitted to electrophysiological study revealing a re-entrant circuit at the level of the medium segment of interventricular septum, successfully treated with transcatheter ablation. This case highlights how the presence of recurrent ventricular arrhythmias at the onset of acute myocarditis, suspected or proven, could be associated with a pre-existing arrhythmogenic substrate, therefore these patients should be submitted to electrophysiological study in order to rule out the presence of arrhythmogenic focuses that can be treated with transcatheter ablation., Emanuele Cecchi, Serena Fatucchi, Elena Crudeli, Cristina Giglioli, and Literatura 15
The kinin receptors are classically involved in inflammation, pain and sepsis. The effects of the kinin B1 receptor agonist des-Arg9 - bradykinin (DBK) and lipopolysaccharide (LPS) were investigated by comparing the membrane potential responses of aortic rings from transgenic rats overexpressing the kinin B1 receptor (B1R) in the endothelium (TGR(Tie2B1)) and Sprague Dawley (SD) rats. No difference in the resting membrane potential in the aorta’s smooth muscle from the transgenic and SD rats was observed. The aorta rings from SD rats hyperpolarized only to LPS but not to DBK, whereas the aorta rings from TGR(Tie2B1) responded by the administration of both drugs. DBK and LPS responses were inhibited by the B1 receptor antagonist R715 and by iberiotoxin in both cases. Thapsigargin induced a hyperpolarization in the smooth muscle of SD rats that was not reversed by R715, but was reversed by iberiotoxin and this hyperpolarization was further augmented by DBK administration. These results show that the model of overexpression of vascular B1 receptors in the TGR(Tie2B1) rats represent a good model to study the role of functional B1 receptors in the absence of any pathological stimulus. The data also show that KCa channels are the final mediators of the hyperpolarizing responses to DBK and LPS. In addition, we suggest an interaction between the B1R and TLR4, since the hyperpolarization induced by LPS could be abolished in the presence of R715.
The pathogenesis of arterial hypertension in autosomal dominant polycystic kidney disease (ADPKD) is complex and likely dependent on interaction of hemodynamic, endocrine and neurogenic factors. We decided to evaluate the role of endothelin (ET1) and nitric oxide (NO) in the regulation of arterial blood pressure (BP) and to determine plasma levels of ET1 and NO in the group of patients with ADPKD. The ADPKD group (18 patients, 6 men + 12 women, mean age 44.611.7 years, with creatinine clearancecorrig > 1.1 ml/s) was compared with a control group of 27 healthy volunteers of comparable age. Plasma levels of ET1 assessed by direct RIA determination in the group of ADPKD patients (11.03±1.8 fmol/ml) were significantly increased (p<0.001) in comparison with the control group (2.660.58 fmol/ml), while no significant differences were observed between normotensive and hypertensive patients in the ADPKD group. Serum levels of NO were evaluated according to the determination of serum levels of their metabolites - nitrites/nitrates. Serum levels of NO in the group of ADPKD patients (39.85±6.38 μmol/l) were significantly higher (p<0.05) in comparison with the control group (22.7±1.20 μmol/l), whereas in the ADPKD group no significant differences were observed between normotensive and hypertensive patients. Thus, our study supports the concept of complex alteration of both vasoconstrictor and vasodilator systems in the pathogenesis of arterial hypertension in ADPKD., M. Merta, J. Reiterová, R. Ryšavá, V. Tesař, M. Jáchymová., and Obsahuje bibliografii
A short review on the role of endothelium and nitric oxide (NO) in experimental hypertension is presented in the light of the literature and our own recent findings. Based on these data, it is concluded that even though there is a lot of evidence in favor of the primary and causal association of endothelial dysfunction and NO in experimental hypertension, it seems still more plausible that they are causative in some types of hypertension only. Our own experience rather speaks for a secondary but still an important participation of endothelium in the maintenance and further elevation of high blood pressure. Endothelium plays a key role in the development of organ damages in hypertension., H. Vapaatalo, E. Mervaala, M.-L. Nurminen., and Obsahuje bibliografii
The Kanzawa spider mite, Tetranychus kanzawai (Acari: Tetranychidae) constructs webs over leaf surfaces and usually lives under these webs. T. kanzawai produces two types of excreta, black and yellow pellets, and uses its webs as a place for excretion. T. kanzawai also uses its webs as a refuge when the predatory mite, Neoseiulus womersleyi (Acari: Phytoseiidae) is present. To clarify what factors deter N. womersleyi from foraging on T. kanzawai webs, I experimentally examined the effects of T. kanzawai excreta on its own fitness (fecundity) and the foraging behaviour of N. womersleyi. When the excreta of T. kanzawai was put on leaf surfaces, the fecundity of T. kanzawai adult females was reduced by the black but not the yellow faecal pellets. On the other hand, predation by N. womersleyi was reduced by the yellow but not the black pellets. Although this effect of the yellow pellets on N. womersleyi did not last on leaf surfaces, it deterred N. womersleyi from staying on the web regardless of its freshness. These results suggest that T. kanzawai deposits black pellets on webs to avoid its negative effect on their own fitness, and yellow pellets are deposited on webs to reduce the risk of predation.
Activation of calmodulin dependent protein kinase (CaMK)II by exercise is beneficial in controlling membrane lipids associated with type 2 diabetes and obesity. Regulation of lipid metabolism is crucial in the improvement of type 2 diabetes and obesity associated symptoms. The role of CaMKII in membrane associated lipid metabolism was the focus of this study. Five to six weeks old male Wistar rats were used in this study. GC×GC-TOFMS technique was used to determine the levels of polyunsaturated fatty acids (linoleic acid, arachidonic acid and 11,14-eicosadienoic acid). Carnitine palmitoyltransferase (Cpt-1) and acetyl-CoA carboxylase (Acc-1) genes expression were assessed using quantitative real time PCR (qPCR). From the results, CaMKII activation by exercise increased the levels of arachidonic acid and 11,14-eicosadienoic acid while a decrease in the level of linolenic acid was observed in the skeletal muscle. The results indicated that exercise-induced CaMKII activation increased CPT-1 expression and decreased ACC-1 expression in rat skeletal muscle. All the observed increases with activation of CaMKII by exercise were aborted when KN93, an inhibitor of CaMKII was injected in exercising rats. This study demonstrated that CaMKII activation by exercise regulated lipid metabolism. This study suggests that CaMKII can be a vital target of
therapeutic approach in the management of diseases such as type 2 diabetes and obesity that have increased to epidemic proportions recently.
Ghrelin, an endogenous ligand for growth hormone secretagogue receptor (GHS-R), has been id entified in the rat and human gastrointestinal tract. Ghrelin has been proposed to play a role in gastric acid secretion. Nitric oxide (NO) was shown as a mediator in the mechanism of ghrelin action on gastric acid secretory function. However, there is a little knowledge about this topic. We have investigated the role of ghrelin in gastric acid secretion and the role of NO as a mediator. Wistar albino rats were used in this study. The pyloric sphincter was ligated through a small midline incision. By the time, saline (0.5 ml, iv) was injected to the control group, ghrelin (20 μg/kg, iv) was injected to the first experimental group, ghrelin (20 μg/kg, iv) +L-NAME (70 mg/kg, sc) was injected to the second group and L-NAME (70 mg/kg, sc) was administered to the third group. The rats were killed 3 h after pylorus ligation; gastric acid secretion, mucus content and plasma nitrite levels were measured. Exogenous ghrelin administration increased gastric acid output, mucus content and total plasma nitrite levels, while these effects of ghrelin were inhibited by applying L-NAME. We can conclude that ghrelin participates in the regulation of gastric acid secretion through NO as a mediator., H. M. Bilgin, C. Tumer, H. Diken, M. Kelle, A. Sermet., and Obsahuje bibliografii a bibliografické odkazy
In Britain, grey squirrels (Sciurus curolinensis Gmelin) and pheasants (Phasianus colchicus Linnaeus) are important hosts of larvae and nymphs of Ixodes ricinus L., the principal F.uropean vector of the Lyme disease spirochaete, Borrelia burgdorferi sensu lalo, T о test whether squirrels are competent hosts of B. burgdorferi s. I., three females were trapped in the wild and then held in captivity. Following treatment, each animal was exposed to uninfected xenodiagnostic I. ricinus ticks. Squirrel A (an adult) which was inoculated experimentally with B. burgdorferi s.l., transmitted the infection to xenodiagnostic ticks. In contrast, squirrel В (a juvenile that was not inoculated)-showed no evidence of infection. Xenodiagnostic ticks that fed on control squirrel С (an adult) became infected and subsequently transmitted the infection experimentally to an uninfected hamster. The results indicated that squirrel С had a disseminated infection acquired in the wild and which persisted for at least 11 weeks. These data clearly demonstrate that grey squirrels are amplifying and reservoir hosts of B. burgdorferi s.l. The strain associated with squirrels was related to the B. afzelii genotype. Two observations implicated pheasants in a similar role; (i) a high prevalence of infection in engorged larvae collected from trapped pheasants, and (ii) the detection of B. burgdorferi s.l. (В. garinii genotype) in the wattle of 1/10 pheasants using PCR. Xenodiagnostic experiments similar to those undertaken with the squirrels are needed to confirm the role of pheasants in the transmission cycle of Lyme disease spirochaetes.
Liver haemodynamics were studied after warm (37 °C) ischaemia of isolated rat livers for periods of 30 s (Group 1), 30 min (Group 2), and 60 min (Group 3) using a constant pressure system with a recirculating blood-free perfusate. Portal flow recovered to basal values within 6 min in livers from Group 1, whereas it was significantly reduced in Group 2 during the initial 15 min and in Group 3 during the first 33 min of reperfusion. Thus, the recovery of liver flow was proportional to the duration of ischaemia. By using the same mode of liver perfusion, the effect of norepinephrine on portal resistance was also studied in normal livers. At the beginning of reperfusion, the values of portal resistance in ischaemic livers were comparable to the values of portal resistance mediated by norepinephrine at concentrations between 10“7 and 10"6 mol/1 in normal livers. The results suggest that vasoconstriction of the hepatovasculature may be a contributing factor to the reperfusion injury of the liver following warm ischaemia.
The prevalence of obesity is increasing worldwide at an alarming rate in both developed and developing countries. Obesity is a chronic complex disease of multifactorial origin resulting from a long-term positive energy balance, in which both genetic and environmental factors are involved. Genetically prone individuals are the first to accumulate fat in the present obesogenic environment. Obesity increases the risks of type 2 diabetes, hypertension, cardiovascular disease, dyslipidemia, arthritis, and several cancers and reduces the average life expectancy. Implementation of effective strategies in prevention and management of obesity should be come an important target in health care systems. Weight changes throughout life depend on the interaction of behavioral, genetic and environmental factors. Weight loss in response to weight management shows a wide range of interindividual variation which is largely influenced by genetic determinants. The strong control of weight loss by genotype was confirmed by twin and family studies. Recently, special attention has been paid to nutritional, hormonal, psychobehavioral and genetic factors which can predict the response to weight reduction programme. In this article currently available data on the role of obesity candidate gene polymorphisms in weight loss and maintenance are reviewed. It is believed that an elucidation of the genetic component in the prognosis of weight management could assist in the development of more effective and individually tailored therapeutic strategies., V. Hainer, H. Zamrazilová, J. Spálová, I. Hainerová, M. Kunešová, B. Aldhoon, B. Bendlová., and Obsahuje bibliografii a bibliografické odkazy