In vivo visualization of kidney and liver damage by Magnetic Resonance Imaging (MRI) may offer an advantage when there is a need for a simple, non-invasive and rapid method for screening of the effects of potential nephrotoxic and hepatotoxic substances in chronic experiments. Here, we used MRI for monitoring chronic intoxication with microcystins (MCs) in rat. Male adult Wistar rats were treated every other day for eight months, either with MC-LR (10 g/kg i.p.) or MC-YR (10 g/kg i.p.). Control groups were treated with vehicle solutions. T1-weighted MR-images were acquired before and at the end of the eight months experimental period. Kidney injury induced by the MCs presented with the increased intensity of T1-weighted MR-signal of the kidneys and liver as compared to these organs from the control animals treated for eight months, either with the vehicle solution or with saline. The intensification of the T1-weighted MR-signal correlated with the increased volume density of heavily injured tubuli (R2 = 0.77), with heavily damaged glomeruli (R2 = 0.84) and with volume density of connective tissue (R2 = 0.72). The changes in the MR signal intensity probably reflect the presence of an abundant proteinaceous material within the dilated nephrons and proliferation of the connective tissue. T1-weighted MRI-is a valuable method for the in vivo screening of kidney and liver damage in rat models of intoxication with hepatotoxic and nephrotoxic agents, such as microcystins.
COBISS.SI-ID: 30744025
Free radical damage is linked to formation of many degenerative diseases, including cancer, cardiovascular disease, cataracts, and aging. Excessive reactive oxygen species (ROS) formation can induce oxidative stress, leading to cell damage that can culminate in cell death. Therefore, cells have antioxidant networks to scavenge excessively produced ROS. The balance between the production and scavenging of ROS leads to homeostasis in general; however, the balance is somehow shifted towards the formation of free radicals, which results in accumulated cell damage in time. Antioxidants can attenuate the damaging effects of ROS in vitro and delay many events that contribute to cellular aging. The use of multivitamin/mineral supplements (MVMs) has grown rapidly over the past decades. Some recent studies demonstrated no effect of antioxidant therapy; sometimes the intake of antioxidants even increased mortality. Oxidative stress is damaging and beneficial for the organism, as some ROS are signaling molecules in cellular signaling pathways. Lowering the levels of oxidative stress by antioxidant supplements is not beneficial in such cases. The balance between ROS and antioxidants is optimal, as both extremes, oxidative and antioxidative stress, are damaging. Therefore, there is a need for accurate determination of individual's oxidative stress levels before prescribing the supplement antioxidants.
COBISS.SI-ID: 4541547
BackgroundVasoactive intestinal polypeptide (VIP) is released from intracardiac neurons during vagal stimulation, ischemia and heart failure which are associated with increased vulnerability to atrial fibrillation (AF). VIP shortens atrial effective refractory periods in dogs. Endogenous VIP contributes to vagally mediated acceleration of atrial electrical remodeling. VIP is also shown to prolong the duration of acetylcholine-induced AF. However, the ionic mechanisms underlying VIP effects are largely unknown. Methods and ResultsVIP's effects on transmembrane ion channels were studied in canine atrial cardiomyocytes using patch-clamp techniques. VIP increased delayed rectifier K+ current and L-type calcium current but decreased the transient outward K+ current and sodium current. Optical mapping technique was used to assess VIP's effects on action potential durations (APD) in isolated canine left atria. VIP shortened APD and slowed conduction velocity (CV) in a dose-dependent manner. Furthermore, VIP increased spatial heterogeneity of APD and CV, as assessed by the standard deviations of APD and CV, and AF inducibility. ConclusionsThrough its diverse effects on ion channels, VIP shortens APD with increased APD spatial heterogeneity and decreases intra-atrial conduction velocity, which may play an important role in the pathogenesis of atrial arrhythmias in scenarios where VIP release is increased.
COBISS.SI-ID: 1125804
The authors were the first or tamong the first authors who found small ammount of pleural fluid in healthy subjects during US examination. Studies by other authors confirmed this finding alo by use of other modalities of medical imaging, such as CT and MRI. Here we describe the physiology of pleural fluid formation ad reabsorption. A clear distinction should be made when reporting the presence of small amounts of pleural fluid between the pathological finding (suggested report by a radiologist: pleural effusion) and physiological presence of the fluid (suggested reporting: pleural fluid). such naming of two conditions may prevent unnecesary additional radiologic investigation.
COBISS.SI-ID: 31021273
The purpose of the study was to establish the effects of training on Wii balance board (WBB) after posterior cruciate ligament (PCL) reconstruction on balance. Training on WBB was performed 4 weeks, 6 times per week, 30-45 min per day. Center of pressure (CoP) sway during parallel and one-leg stance, and body weight distribution in parallel stance were measured. Additionally, measurements of joint range of motion and limb circumferences were taken before and after training. After training, the body weight was almost equally distributed on both legs. Decrease in CoP sway was most significant for one-leg stance with each leg on compliant surface with eyes open and closed. The knee joint range of motion increased and limb circumferences decreased. The result allow the conclusion that WBB for balance training after PCL reconstruction might be recommended.
COBISS.SI-ID: 4534635