Barbara Nowak

Antioxidants activities and concentration of selenium, zinc and copper in preterm and IUGR human placentas

The aim of this study was to examine changes in activities of cytochrome c oxidase (CCO), glucose-6-phosphate dehydrogenase (G6PDH), Cu-Zn superoxide dismutase (Cu-Zn SOD), glutathione peroxidase (GSH-Px), glutathione (GSH) levels and copper (Cu), zinc (Zn) and selenium (Se) concentrations, and to assess the possible differences between preterm placentas, placentas from term pregnancies complicated by intrauterine growth restriction (IUGR) and full-term control placentas. The enzyme activities and the level of GSH decreased in IUGR and preterm placentas in comparison with the control group. CCO activity and GSH level in preterm placentas were markedly lower compared with the IUGR (P<0.01; P<0.05) and control (P<0.01; P<0.05) placentas, respectively. In IUGR placentas the level of Cu was reduced by 23% (P<0.05) and Zn by 37%. In preterm placentas the level of Cu was reduced by 19% and Zn by 42%. Se level in IUGR and preterm placentas was higher (P<0.05) by 28% and 32% than in control group, respectively. The strong relation was observed between birth weight and CCO activity, birth weight and Cu-Zn SOD activity, and a low level of Zn and Cu influenced the birth weight especially in IUGR cases. Moreover, the strong inverse correlation between Se level and birth weight, Se level and placental weight and Se level and CCO activity are new findings.

Alterations in hippocampal calcium-binding neurons induced by stress models of depression: a preliminary assessment

In this study, the neuropathological changes induced by chronic unpredictable stress (CUS) and chronic mild stress (CMS) in calbindin D-28K (CB) and parvalbumin (PV) immunoreactive neurons in the rat hippocampus were demonstrated. We used immunohistochemical techniques to quantify the numerical density and morphological changes of PV immunoreactive and CB immunoreactive neurons in the dentate gyrus (DG) and the CA1 and CA3 regions of the hippocampus. We also assessed cell proliferation (Ki-67) and apoptotic processes (active caspase-3) in the DG. We found a significant decrease (16.6% for CUS and 13.3% for CMS) in the numerical density of granule cells (GC), alterations in the CB immunoreactive cells of the GC in the DG and an impairment of mossy fiber CB immunolabelling in the CA3. These changes were not accompanied by a decrease in Ki-67 labeling or the level of caspase-3 in the DG. These data indicate a stress-induced reduction of calcium binding neuron parameters, which may be related to the behavioral paradigms exhibited in these models.

Different pattern of changes in calcium binding proteins immunoreactivity in the medial prefrontal cortex of rats exposed to stress models of depression

Reductions in the number and size of neurons in the medial prefrontal cortex (mPFC) have been documented in many post-mortem studies of depressed patients and animals exposed to stress. Here, we examined the effect of chronic unpredictable stress (CUS) and chronic mild stress (CMS) on specific populations of neurons in the rat mPFC. Antibodies directed against parvalbumin (PV), calbindin D-28K (CB) and active caspase-3 have been used to quantify the numerical density of PV-immunoreactive (PV-ir), CB-ir and active caspase-3-ir cells, and to measure the relative optical density of neuropil. CUS decreased the density of CB-ir neurons and the optical density of CB-ir neuropil. In turn, CMS increased the densities of both CB-ir neurons and neuropil, while PV-ir neurons and PV-ir neuropil were not changed. The frequency distribution of neuronal surface areas was significantly different only for PV-ir neurons, and only between the control and CUS group. CMS reduced the density of active caspase-3-ir cells while CUS did not. We concluded that the mPFC reveals a different pattern of changes in neurons containing calcium binding proteins and active caspase-3 immunoreactivity in response to CUS and CMS.

Neocortical injuries at different developmental stages determine different susceptibility to seizures induced in adulthood

Gliosis, axonal sprouting and remodelling of nerve connections in the injured brain have been regarded as epileptogenic processes dependent on the age when the injury was inflicted. The present study examines whether brains injured at different developmental stages may acquire different susceptibility to experimental status epilepticus induced in adulthood. In 6- and 30-day-old Wistar rats (P6s and P30s, respectively), a mechanical injury was performed in the left cerebral hemisphere. On postnatal day 60, all the animals and controls received single injections of kainic acid to evoke status epilepticus. During a 6-h period following the injection, the animals were observed continuously and motor symptoms of seizure activity were recorded and rated. P6s showed significantly lower intensity of kainic acid-induced epileptic symptoms and significantly longer survival than controls or P30s. In P30s, no significant change was detected. The data provide evidence that the developmental stage when the brain is injured determines epileptogenecity of the lesion. However, a considerable discrepancy between these data and those obtained previously following pilocarpine administration in the same experimental models of brain injury shows that each of the two models of epilepsy may display different aspects of the same age-dependent process triggered by the brain injury.

3-[4-(3-Trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one and pregabalin attenuate tactile allodynia in the mouse model of chronic constriction injury

Abstract Purpose: There is a strong medical demand to search for novel, more efficacious and safer than available, analgesics for the treatment of neuropathic pain. This study investigated antinociceptive activity of intraperitoneally administered 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one (LPP1) and pregabalin in the chronic constriction injury (CCI) model of neuropathic pain in mice and evaluated these drugs’ influence on motor coordination. In addition, microscopic examinations of the sciatic nerve were performed to assess, if a surgical method or drug treatment caused changes in the structure of this nerve. Moreover, the alterations of nerve growth factor (NGF) content after drug treatment were assessed. Methods: Antiallodynic and antihyperalgesic activities of LPP1 and pregabalin were assessed in the von Frey and hot plate tests. Motor-impairing properties were evaluated in the rotarod test. Microscopic examinations of the sciatic nerve were performed using electron microscope. In immunohistochemical assays the content of NGF in the sciatic nerve after single or repeated administration of test drugs was assessed. Results: Microscopic examinations of the sciatic nerve revealed ultrastructural changes in nerve fibers indicating for neurodegenerative processes induced by CCI. Seven days after CCI surgery LPP1 and pregabalin reduced tactile allodynia in von Frey test (ED50 values were 1.5 and 15.4 mg/kg, respectively). None of the test drugs at dose range 0.5–100 mg/kg induced motor deficits in the rotarod test. In immunohistochemical assays repeated doses of pregabalin and LPP1 elevated NGF content. Conclusions: LPP1 has antiallodynic properties and is an interesting lead structure in the search for novel analgesics used in neuropathic pain.

Human Placenta as a Biomarker of Environmental Toxins Exposure – Long-Term Morphochemical Monitoring

A healthy lifestyle, concerning the choice of diet and physical activity, has become increasingly important to human choice. However, even with the best of intentions and the best individual lifestyle choices, unfortunately we are not able to control all of the factors affecting our body, even in the simplest terms of chemical and physical pollutants of the ambient environment. Biomonitoring is the sphere of human interest regarding how a variety of environmental factors affect living organisms. In practice this means most frequently the elucidation of the adverse effects of environmental pollution, and looking for meaningful markers of such effects, which demonstrate not only the causal relationship with the agent but also a doseproportionality of the causative agent. The efforts related to the monitoring make sense here, and can ultimately lead to the elimination of negative acting stimuli. In a large number of cases this is possible. Choice of human placenta for monitoring pollutants proven to be detrimental to human health has enabled us to lead real-time monitoring and long-term monitoring. With the exception of hair and placenta, ie transient organ which serves the needs of developing embryo and fetus, the other specimens used for real time monitoring require invasive procedures, or are obtained post-mortem.