Only limited data are available on body surface potential distribution during atrial activation. The aim of this study was to establish the distributions and to analyze chosen quantitative parameters of atrial isointegral maps recorded using a limited 24-lead system in a young healthy population. A total of 166 subjects underwent a procedure of body surface potential mapping. Isointegral maps during the P wave were constructed and qualitatively and quantitatively evaluated. Three types of atrial activation in individual maps were found according to the different shape of the zero isointegral line and to mutual positions of extrema. The most frequently occurring type resembled the group mean maps and was in good agreement with published data obtained from full lead systems. The highest extrema were found in the young men group, while, surprisingly, the lowest values in the young women group. All minima and the majority of maxima were recorded outside the ranges of standard chest leads. The usefulness of the limited lead system to record isointegral P wave maps was shown and new data were presented that can be useful in noninvasive evaluation of atrial pathologies., K. Kozlíková., and Obsahuje bibliografii
Animal models are important for the investigation of mechanisms and therapeutic approaches in various human diseases, including schizophrenia. Recently, two neurodevelopmental rat models of this psychosis were developed based upon the use of subunit selective N-methyl-D-aspartate receptor agonists - quinolinic acid (QUIN) and N-acetyl-aspartyl-glutamate (NAAG). The aim of this study was to evaluate pain perception in these models. QUIN or NAAG was infused into lateral cerebral ventricles neonatally. In the adulthood, the pain perception was examined. The rats with neonatal brain lesions did not show any significant differences in acute mechanical nociception and in formalin test compared to controls. However, the neonatally lesioned rats exhibited significantly higher pain thresholds in thermal nociception. Increased levels of mechanical hyperalgesia, accompanying the sciatic nerve constriction (neuropathic pain), were also observed in lesioned rats. Although hyperalgesia was more pronounced in QUIN-treated animals, the number of c-Fos-immunoreactive neurons of the lumbar spinal cord was similar in experimental and control rats. We conclude that neonatal brain lesions attenuated the thermal perception in both nociceptive and neuropathic pain whereas mechanical pain was increased in the model of neuropathic pain only. Thus, nociceptive and neuropathic pain belongs - in addition to behavioral changes - among the parameters which are affected in described animal models of schizophrenia., M. Franěk ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Recent studies demonstrated remote effects of renal ischemia/reperfusion (I/R) injury on some organs such as brain, liver, and lungs. We investigated the effects of renal I-R injury on function, histology and oxidative stress state of pancreas. Twenty -four male adult Sprague-Dawley rats were divided equally into 2 groups; sham group: rats underwent midline laparotomy and dissection of renal pedicles without renal ischemia, and ischemic group: rats underwent bilateral renal ischemia for 45 min. Renal functions (serum creatinine and BUN), pancreatic functions (serum amylase, lipase and insulin) and fasting blood glucose were measured at 2 h, 1 day, 3 days and 7 days after ischemia. Also, pancreatic histology and malondialdehyde (MDA), catalase and reduced glutathione (GSH) were examined at 2 h and 7 days after ischemia. The ischemic rats showed significant increase in serum creatinine and BUN with significant increase in serum amylase and lipase at 2 h, 1 day and 3 days after ischemia. Blood glucose and fasting insulin showed no significant change apart from significant increase in insulin in sham group at 1 day after ischemia. Pancreas isolated from ischemic rats showed significant increase in histopathological damage score and significant increase in MDA and catalase enzyme with decrease in GSH. In conclusion, bilateral renal ischemia for 45 min caused significant impairment of pancreatic functions and histology. This might be due to deficiency of antioxidant and increased lipid peroxidations in pancreatic tissues., A. M. Hussein ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Paraoxonase 1 (PON1), an antioxidant enzyme closely associated with HDL (high-density lipoproteins), preserves LDL (low-density lipoproteins) against oxidation. Less protection may be therefore supposed by decreased PON1 activity. This study was undertaken to investigate the association of PON1 gene polymorphisms with diabetic angiopathy and to evaluate the relationship of these polymorphisms with PON1 activity. Total of 86 Type 1 (T1DM) and 246 Type 2 (T2DM) diabetic patients together with 110 healthy subjects were examined. DNA isolated from leukocytes was amplified with polymerase chain reaction (PCR) followed by restriction enzyme digestion. The products were analyzed for L55M and Q192R polymorphisms in coding region and for –107 C/T and –907 G/C in promotor sequence of PON1. Serum enzyme activity was measured spectrophotometrically. Significant differences were found between T1DM or T2DM and control persons in L55M polymorphism (allele M more frequent in T1DM and T2DM vs. controls, p<0.05) and Q192R polymorphism (R allele less frequent in T1DM and T2DM vs. controls, p<0.01) of the PON1 gene. Serum PON1 activity was significantly decreased in T1DM (110±68 nmol/ml/min) and T2DM patients (118±69 nmol/ml/min) compared to the control persons (203±58 nmol/ml/min), both p<0.01. The presence of MM and QQ genotypes was accompanied by lower PON1 activity than of LL and RR genotypes (p<0.05), respectively. Better diabetes control was found in patients with LL than with MM genotypes and similarly in RR genotype than QQ genotype with p<0.05. Significantly different allele frequencies were found in diabetic patients with macroangiopathy than in those without it (M: 0.59 vs. 0.44. R: 0.12 vs. 0.19, p<0.01). The association of PON1 polymorphisms, lower PON1 activity and poorer diabetes control found in patients with macroangiopathy further support the idea of genetic factors contributing to the development of vascular disorders in diabetes., M. Flekač, J. Škrha, K. Zídková, Z, Lacinová, J. Hilgertová., and Obsahuje bibliografii a biblografické odkazy
Secondary hyperparathyroidism (SHPT) may contribute to the systemic illness that accompanies chronic heart failure (CHF). Healthy elderly with vitamin D deficiency who did not develop hyperparathyroidism (functional hypoparathyroidism, FHPT) had lower mortality than those who di d. This study was designed to examine determinants of the PTH response in the vitamin D insufficient CHF patients. Sixty five vitamin D insufficient males with NYHA class II and III and 20 control subjects age ≥ 55 years were recruited. Echocardiography, physical performance, NT-pro-BNP, PTH, 25-hydroxyvitamin D (25(OH)D), adiponectin and bone activity surrogat e markers (OPG, RANKL, OC, β-CTx) were assessed. Increased NYHA cl ass was associated with SHPT, while physical performance was inferior compared to FHPT. SHPT was associated with lower left ventricular ejection fraction (LVEF) and flow mediated dilatation, but with higher left heart dimensions, left ventricular mass index and right ventricular systolic pressure. CHF patients with SHPT had increased NT-pro-BNP, adiponectin and bone markers, but decreased 25(OH)D compared to those with FHPT. Independent determinants for SHPT in CHF patients with vitamin D insufficiency were LVEF, adiponectin and β-CTx, irrespective of renal function and serum vitamin D levels. In conclusion, increased PTH levels, but not low vitamin D, demonstrated close relation to CHF severity., B. Bozic ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Parathyroid hormone (PTH) increases the release of serum calcium through osteoclasts, which leads to bone resorption. Primary, PTH stimulates osteoblasts leading to increase RANKL (receptor activator for nuclear factor kappa-B ligand) expression and thus differentiation of osteoclasts. In kidneys, PTH increases calcium and decrease phosphate reabsorption. In kidneys, PTH stimulates 1alpha-hydroxylase to synthesize active vitamin D. Primary hyperparathyroidism (PHPT) is characterized by skeletal or renal complications. Nowadays, the classical form of PHPT is less seen and asymptomatic or subclinical (oligo symptomatic) forms are more frequent. Previously, it was thought that cortical bone is preferably affected by PHPT and that predispose bones to fracture at sites with a higher amount of cortical bone. However, an increased risk of vertebral fractures has been found by most of the studies showing that also trabecular bone is affected. Bone Mass measurement (BMD) at all skeletal sites is advised, but another specific tool for fracture assessment is needed. Trabecular bone score (TBS), an indirect measure of trabecular bone, maybe a useful method to estimate fracture risk. TBS is associated with vertebral fractures in PHPT regardless of BMD, age, BMI and gender. Furthermore, there is an association between TBS and high resolution peripheral quantitative computed tomography (HR-pQCT) parameters in the trabecular and cortical compartment. However, studies considering the effect of PHPT treatment on TBS are more conflicting. Secondary hyperparathyroidism caused by vitamin D deficiency was associated with impaired bone microarchitecture in all age categories, as measured by TBS and Hr-pQCT with further improvement after treatment with vitamin D. and Martin Kužma, Peter Jackuliak, Zdenko Killinger, Juraj Payer.
Repeated administration of partial agonist of benzodiazepine receptors Ro 19-8022 (a derivative of quinolizine class) does not elicit withdrawal in adult rats. Our older data demonstrated that single injection of Ro 19-2088 to immature rats induces increased sensitivity to convulsant action of pentylenetetrazol as a withdrawal phenomenon. To know if repeated administration of the partial agonist has the same effect we injected rats at postnatal days 7 to 11 with an anticonvulsant dose of Ro 19-2088 (0.5 mg/kg i.p.) and tested them 24 h, 48 h and 4 days after the last injection. Repeated administration of Ro 19-8022 resulted also in an increased sensitivity to convulsant action of pentylenetetrazol in immature rats (higher incidence and severity of seizures). This effect was significant 24 h after the last injection but only outlined 48 h after administration. No signs of hypersensitivity were seen at 4-day interval. There is a difference between immature and adult brain in an appearance of withdrawal symptom after administration of the partial agonist of benzodiazepine receptors Ro 19-2088., H. Kubová, P. Mareš., and Obsahuje seznam literatury
The freely diffusible radical, nitric oxide (NO), has been assumed to act as a retrograde signaling molecule that modulates transmitter release. Acetylcholine (ACh) is known to function as a typical neurotransmitter. In the present work we have examined the presence of both transmitters (NO and ACh) and their possible relations in the rabbit spinal cord. In our experiments we have used histochemical methods for the visualization of acetylcholinesterase (AChE) and NADPH diaphorase (NADPH-d) which label neurons that express nitric oxide synthase (NOS). Both histochemical methods were performed separately or together on the same sections of the thoracic spinal cord. NADPH-d positive dark blue stained neurons were seen mostly in superficial and deep layers of the dorsal horn, preganglionic autonomic neurons and pericentral area. The presence of AChE positive amber yellow neurons was confirmed mostly in motoneurons located in the ventral horns and in neurons of the pericentral and intermediate zone. Besides the above mentioned neurons, also double-labeled neurons were found which contained both the yellow and dark blue histochemical product. Their presence was confirmed in the intermediate zone and in the pericentral area. Thus, the co-existence of NADPH-d and AChE occurred in the location of interneurons. Our observations suggest that NO may play a role in the control of cholinergic neuronal activity and that NO can be involved in the modulation of synaptic transmission., D. Kluchová, K. Schmidtová, S. Rybárová, K, Lovásová, M. Pomfy, T. Prosbová, A. Vatľak., and Obsahuje bibliografii
The effect of Na+-K+-ATPase inhibitor ouabain on the resting membrane potential (Vm) was studied by glass microelectrodes in isolated somatic longitudinal muscles of the earthworm Lumbricus terrestris and compared with frog sartorius muscle. In earthworm muscle, Vm was -49 mV (inside negative) in a reference external solution with 4 mmol/l K+. The electrogenic participation of Na+-K+-ATPase was absent in solutions with very low concentrations of 0.01 mmol/l K+, higher in 4 and 8 mmol/l K+ (4-5 mV) and maximal (13 mV) in solutions containing 12 mmol/l K+ where Vm was -46 mV in the absence and -33 mV in the presence of 1x10-4 M ouabain. The electrogenic participation of Na+-K+-ATPase was much smaller in m. sartorius of the frog Rana temporaria bathed in 8 and 12 mmol/l K+. The results indicate that the Na+-K+-ATPase is an important electrogenic factor in earthworm longitudinal muscle fibres and that its contribution to Vm depends directly on the concentration of K+ in the bathing solution., E. M. Volkov, L. F. Nurullin, I. Švandová, E. E. Nikolsky, F. Vyskočil., and Obsahuje bibliografii
This review concerns the role of nitric oxide (NO) in the pathogenesis of different models of experimental hypertension (NO-deficient, genetic, salt-dependent), which are characterized by a wide range of etiology. Although the contribution of NO may vary between different models of hypertension, a unifying characteristic of these models is the presence of oxidative stress that participates in the maintenance of elevated arterial pressure and seems to be a common denominator underlying endothelial dysfunction in various forms of experimental hypertension. Besides the imbalance between the endothelial production of vasorelaxing and vasoconstricting compounds as well as the relative insufficiency of vasodilator systems to compensate augmented vasoconstrictor systems, there were found numerous structural and functional abnormalities in blood vessels and heart of hypertensive animals. The administration of antihypertensive drugs, antioxidants and NO donors is capable to attenuate blood pressure elevation and to improve morphological and functional changes of cardiovascular system in some but not all hypertensive models. The failure to correct spontaneous hypertension by NO donor administration reflects the fact that sympathetic overactivity plays a key role in this form of hypertension, while NO production in spontaneously hypertensive rats might be enhanced to compensate increased blood pressure. A special attention should be paid to the modulation of sympathetic nervous activity in central and peripheral nervous system. These results extend our knowledge on the control of the balance between NO and reactive oxygen species production and are likely to be a basis for the development of new approaches to the therapy of diseases associated with NO deficiency., J. Török., and Obsahuje bibliografii a bibliografické odkazy