Alexander M. Trbovich

Hematological parameters' changes in mice subchronically exposed to static magnetic fields of different orientations.

Static magnetic fields (SMFs) are time independent fields whose intensity can be spatially dependent. This study investigates influence of subchronic continuous exposure to upward and downward directed SMF on hematological parameters and spleen cellularity in mice. The experiment is performed on the Northern hemisphere; consequently, the vertical component of geomagnetic field is directed downward. Male, Swiss-Webster, 6 weeks old mice were exposed to the vertically declining SMF. Mice were divided in three groups and continuously exposed or not exposed for 28 days to the SMF characterized by the averaged field of 16 mT and averaged field gradient of 10 mT/cm. Differently oriented SMF did not alter hemoglobin and hematocrit content among the groups. However, the groups exposed to the upward and downward fields had statistically significant higher levels of serum transferrin compared to the control. Moreover, spleen cellularity in animals in the downward group was significantly higher compared to the upward and control group. In addition, spleen lymphocytes in both of the exposed groups were significantly higher than in the control group. In contrast, spleen granulocytes in the exposed groups were significantly lower than in the control group. Significant decrease was also observed in brain and liver iron content with concomitant increase of iron in serum and spleen in exposed animals. Subchronic continuous exposure to 16 mT SMF caused lymphocyte and granulocyte redistribution between spleen and blood. This distribution is typical for stress induced hematological changes. These results suggest that observed changes were not due to an unspecific stress response, but that they were rather caused by specific adaptation to subchronic SMF exposure.

Mitochondrial impairment, apoptosis and autophagy in a rat brain as immediate and long-term effects of perinatal phencyclidine treatment — influence of restraint stress

Phencyclidine (PCP) acts as a non-competitive antagonist of glutamatergic N-methyl-d-aspartate receptor. Its perinatal administration to rats causes pathophysiological changes that mimick some pathological features of schizophrenia (SCH). Numerous data indicate that abnormalities in mitochondrial structure and function could be associated with the development of SCH. Mitochondrial dysfunction could result in the activation of apoptosis and/or autophagy. The aim of this study was to assess immediate and long-term effects of perinatal PCP administration and acute restraint stress on the activity of respiratory chain enzymes, expression of apoptosis and autophagy markers and ultrastructural changes in the cortex and hippocampus of the rat brain. Six groups of rats were subcutaneously treated on 2nd, 6th, 9th and 12th postnatal days (P), with either PCP (10mg/kg) or saline (0.9% NaCl). One NaCl and one PCP group were sacrificed on P13, while other two NaCl and PCP groups were sacrificed on P70. The remaining two NaCl and PCP groups were subjected to 1h restraint stress prior sacrifice on P70. Activities of respiratory chain enzymes were assessed spectrophotometrically. Expression of caspase 3 and AIF as markers of apoptosis and Beclin 1, p62 and LC3, as autophagy markers, was assessed by Western blot. Morphological changes of cortical and hippocampal ultrastructure were determined by transmission electron microscopy. Immediate effects of perinatal PCP administration at P13 were increased activities of complex I in the hippocampus and cytochrome c oxidase (COX) in the cortex and hippocampus implying mitochondrial dysfunction. These changes were followed by increased expression of apoptotic markers. However the measurement of autophagy markers at this time point has revealed decrease of this process in cortex and the absence of changes in hippocampus. At P70 the activity of complex I was unchanged while COX activity was significantly decreased in cortex and increased in the hippocampus. Expressions of apoptotic markers were still significantly higher in PCP perinatally treated rats in all investigated structures, but the changes of autophagy markers have indicated increased level of autophagy also in both structures. Restraint stress on P70 has caused increase of COX activity both in NaCl and PCP perinatally treated rats, but this increase was lower in PCP group. Also, restraint stress resulted in decrease of apoptotic and increase of autophagy processes especially in the hippocampus of PCP perinatally treated group. The presence of apoptosis and autophagy in the brain was confirmed by transmission electron microscopy. In this study we have demonstrated for the first time the presence of autophagy in PCP model of SCH. Also, we have shown increased sensitivity of PCP perinatally treated rats to restraint stress, manifested in alterations of apoptotic and autophagy markers. The future studies are necessary to elucidate the role of mitochondria in the pathophysiology of SCH and putative significance for development of novel therapeutic strategies.

Subchronic exposure to static magnetic field differently affects zinc and copper content in murine organs

Abstract Purpose Static magnetic fields (SMF) have been widely used in research, medicine and industry. Since zinc and copper play an important role in biological systems, we studied the effects of the subchronic continuous SMF exposure on their distribution in murine tissues. Materials and methods For 30 days, mice were exposed to inhomogeneous, vertical, downward or upward oriented SMF of 1 mT averaged intensity with spatial gradient in vertical direction. Results SMF decreased the amount of copper and zinc in liver. In brain, zinc levels were increased and copper levels were decreased. In spleen, zinc content was reduced, while copper amount remained unchanged. Conclusions Subchronic exposure to SMF differently affected copper and zinc content in examined organs, and the changes were more pronounced for the downward oriented field. The outcome could be attributed to the protective, rather than the harmful effect of SMF.

Toxoplasma gondii infection induces lipid metabolism alterations in the murine host

Host lipids have been implicated in the pathogenesis of Toxoplasma gondiiinfection. To determine if Toxoplasmainfection influences the lipid status in the normal host, we assessed serum lipids of Swiss-Webster mice during infection with the BGD-1 strain (type-2) at a series of time points. Mice were bled at days zero and 42 post-infection, and subgroups were additionally bled on alternating weeks (model 1), or sacrificed at days zero, 14 and 42 (model 2) for the measurement of total cholesterol (Chl), high density lipoproteins (HDL), low density lipoproteins (LDL) and triglycerides and adiponectin. At day 42, brains were harvested for cyst enumeration. A significant decrease (p = 0.02) in HDL and total Chl was first noted in infected vs. control mice at day 14 and persisted to day 42 (p = 0.013). Conversely, LDL was unaltered until day 42, when it increased (p = 0.043). Serum LDL levels at day 42 correlated only with cyst counts of above 300 (found in 44% mice), while the change in HDL between days zero and 42 correlated with both the overall mean cyst count (p = 0.041) and cyst counts above 300 (p = 0.044). Calculated per cyst, this decrease in HDL in individual animals ranged from 0.1-17 µmol/L, with a mean of 2.43 ± 4.14 µmol/L. Serum adiponectin levels remained similar between infected and control mice throughout the experiment.

Serum β2-Microglobulin as a Marker of Congenital Toxoplasmosis and Cytomegalovirus Infection in Preterm Neonates

Background: Fetal serum β2-microglobulin (β2M) has been reported as a reliable indicator of fetal infectious diseases. Objectives: To evaluate serum β2M as a marker of congenital toxoplasmosis or cytomegalovirus (CMV) infection in neonates. Methods: β2M was retrospectively measured in 72 neonatal serum samples from preterm neonates. Of these, 32 originated from neonates with serological evidence of congenital toxoplasmosis (n = 12) and CMV infection (n = 20), while 40 samples from neonates in which both infections were serologically excluded served as controls. β2M levels were compared between the infection and control groups. Results: Mean (±SEM) β2M levels were significantly higher in the groups of neonates infected with Toxoplasma (5.64 ± 0.61 mg/l) (p = 0.014) and CMV (6.06 ± 0.66 mg/l) (p < 0.0001) than in the control group (3.80 ± 0.2). Against the cut-off level of 5 mg/l, β2M was normal in 36 of the 40 uninfected neonates examined, indicating a specificity of 90%. In contrast, it was elevated in 66.7% (8/12) and 65% (13/20) of the Toxoplasma and CMV-infected neonates, respectively, indicating an overall sensitivity of 66%. Conclusions: In the absence of urogenital disorders, an increase in β2M in neonates is likely to be infection-induced. We showed that serum β2M is increased in congenital toxoplasmosis and CMV infection in the first weeks of life.

Quantification of structural changes in acute inflammation by fractal dimension, angular second moment and correlation.

The aim of the study was to examine alteration and possible application of fractal dimension, angular second moment, and correlation for quantification of structural changes in acutely inflamed tissue.

Analytical Description of Two-Dimensional Magnetic Arrays Suitable for Biomedical Applications

Two-dimensional magnetic arrays are used to generate a magnetic field that pervades a layer of volume above the arrays surface, often creating regions of high magnetic flux density gradients. We have recently employed an array with equally oriented magnetic moments of individual elements in several biomedical experiments. We have chosen this type of array because of the slowly decreasing magnetic field it produces, which extends far from the arrays surface and permeates the experimental volume. In order to fully define experimental conditions related to the applied magnetic field, we derive exact closed-form expressions for the magnetic flux density. Based on these analytical expressions and exploiting the array periodicity, a method is proposed for the approximate assessment of the main magnetic field parameters of interest-mean magnetic flux density and mean gradient of its component perpendicular to the arrays surface. The obtained approximate assessment can further serve as a tool for the design of arrays with the desired mean field parameters. All the results are verified and validated by comparison with the finite element modeling as well as measurements.

Evidence for host genetic regulation of altered lipid metabolism in experimental toxoplasmosis supported with gene data mining results

Toxoplasma gondii is one of the most successful parasites on Earth, infecting a wide array of mammals including one third of the global human population. The obligate intracellular protozoon is not capable of synthesizing cholesterol (Chl), and thus depends on uptake of host Chl for its own development. To explore the genetic regulation of previously observed lipid metabolism alterations during acute murine T. gondii infection, we here assessed total Chl and its fractions in serum and selected tissues at the pathophysiological and molecular level, and integrated the observed gene expression of selected molecules relevant for Chl metabolism, including its biosynthetic and export KEGG pathways, with the results of published transcriptomes obtained in similar murine models of T. gondii infection. The serum lipid status as well as the transcript levels of relevant genes in the brain and the liver were assessed in experimental models of acute and chronic toxoplasmosis in wild-type mice. The results showed that acute infection was associated with a decrease in Chl content in both the liver and periphery (brain, peripheral lymphocytes), and a decrease in Chl reverse transport. In contrast, in chronic infection, a return to normal levels of Chl metabolism has been noted. These changes corresponded to the brain and liver gene expression results as well as to data obtained via mining. We propose that the observed changes in Chl metabolism are part of the host defense response. Further insight into the lipid metabolism in T. gondii infection may provide novel targets for therapeutic agents.

Static magnetic field reduces blood pressure short-term variability and enhances baro-receptor reflex sensitivity in spontaneously hypertensive rats

Abstract Purpose: It has been shown that chronic exposure of young spontaneously hypertensive rats (SHR) to static magnetic field (SMF) delays the development of overt hypertension. Therefore the aim of the present work was to investigate the effects of SMF on autonomic cardiovascular control in adult spontaneously hypertensive rats. Materials and methods: Experiments were performed in freely moving spontaneously hypertensive rats equipped with femoral arterial catheter for blood pressure recording. Spontaneously hypertensive rats were exposed for 30 days to upward-oriented SMF (n = 17) or downward-oriented SMF (n = 17) of 16 mT intensity. A control group of spontaneously hypertensive rats (n = 17) was not exposed to SMF. Neurogenic cardiovascular control was evaluated by spectral analysis of arterial blood pressure and heart rate short-term variability and baro-receptor reflex sensitivity using the sequence method. Results: Exposure of spontaneously hypertensive rats to both upward- and downward-oriented SMF significantly reduced arterial blood pressure and enhanced baro-receptor reflex sensitivity. Downward-oriented SMF reduced heart rate, too. SMF of either orientation reduced systolic blood pressure variability in very low frequency domain while downward-oriented SMF also reduced low-frequency and increased high frequency domains. Conclusion: It follows that prolonged exposure to SMF is beneficial for neurogenic cardiovascular control in hypertension.

Effects of IL-33/ST2 pathway in acute inflammation on tissue damage, antioxidative parameters, magnesium concentration and cytokines profile

AIM The aim of this study was to examine the role of IL-33/ST2 pathway in a pathogenesis of acute inflammation and its effects on tissue damage, antioxidative capacity, magnesium concentration and cytokine profile in acutely inflamed tissue. MATERIAL AND METHODS Male mice were randomly divided in four groups: wild-type control group (WT-C), ST2 knockout control group (KO-C), wild-type inflammatory group (WT-I), and ST2 knockout inflammatory group (KO-I). Acute inflammation was induced in WT-I and KO-I by intramuscular injection of turpentine oil, while mice in WT-C and KO-C were treated with saline. After 12h, animals were euthanized, and blood was collected for determination of creatine kinase (CK) and aspartate transaminase (AST) activity. The treated tissue was used for histopathological analysis, determination of volume density of inflammatory infiltrate (Vdii) and necrotic fiber (Vdnf), gene expression of interleukin (IL)-33, ST2, tumor necrosis factor alpha (TNF-alpha), IL-6, IL-12p35, and transforming growth factor beta (TGF-beta), concentration of magnesium (Mg), copper (Cu), selenium (Se), manganese (Mn) and reduced glutathione (GSH), and superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity. RESULTS Presence of inflammatory infiltration and necrosis in the treated tissue was histopathologically confirmed in WT-I and KO-I. Vdii was significantly higher in WT-I when compared to KO-I, whereas Vdnf did not significantly differ between WT-I and KO-I. CK and AST significantly increased in both inflammatory groups when compared to corresponding control groups. However, the values of CK and AST were significantly higher in WT-I than in KO-I. Mg in the treated tissue was significantly lower in WT-I in comparison to WT-C and KO-I, while there was no significant difference between KO-C and KO-I. There was no significant difference in Cu, Se, and Mn in the treated tissue between WT-C, KO-C, WT-I and KO-I. Gene expression of IL-33 in the treated tissue increased in both inflammatory groups when compared to the corresponding control groups, but it was significantly higher in KO-I than in WT-I. Gene expression of ST2 in the treated tissue was significantly higher in WT-I than in WT-C. Gene expression of TNF-alpha, IL-6, and IL-12p35 in the treated tissue was significantly higher in WT-I and KO-I than in the corresponding control groups, and IL-6 was significantly higher in KO-C than in WT-C. TGF-beta gene expression in the treated tissue was significantly higher in KO-I when compared to WT-I, while there was no difference between WT-C and KO-C. SOD activity decreased at the site of acute inflammation in both inflammatory groups, while the GPx activity increased. GSH in the treated tissue was significantly higher in KO-I than in KO-C or WT-I. CONCLUSION The results of our study have indicated, to our knowledge for the first time, that IL-33/ST2 pathway plays a role in enhancing inflammation and tissue damage at the site of acute inflammation by affecting the concentration of magnesium and GSH, important for antioxidative capacity, as well as gene expression of anti-inflammatory cytokine TGF-beta.