Expression of the P53 Protein and Morphological Changes in Neurons in the Pyramidal Layer of the Hippocampus After Simulation of Surgical Interventions in the Nasal Cavity in Rats.

BACKGROUND/AIMS: To determine the role of surgical stress on the formation of p53-positive and dark neurons (DN) in the hippocampus, and to examine the parallelism of their formation in the pyramidal layer of the hippocampus. METHODS: Simulated septoplasty was performed on 20 Wistar rats. The hippocampus and dentate gyrus (DG) were examined, in which the number of DN and p53-positive neurons was determined at 2, 4 and 6 days after surgery. In each rat, 10 brain slices were stained with antibodies to p53 protein with Meyer's haematoxylin and 10 slices were stained with Nissl toluidine blue. Hippocampal subfields CA1, CA2, CA3 and DG were studied. In the pyramidal subfield layer, the absolute number of neurons that were nuclear antibody-positive to p53 protein was counted, as well as the number of dark neurons. The counting area in each subfield was 20934±1260 µm2. Neurons are counted using the Aperio ImageScope program. For the histological specimen analysis, the ImageJ software was used. The data obtained using cell counting methods were presented as mean ± SE. Then, they were compared between both groups using a t-test SPSS 21software. RESULTS: Compared with the control group (n = 5), the number of DN and p53-positive neurons increased in experimental animals at all periods. A direct relationship was obtained between the increase in the number of DN and p53-positive neurons in the hippocampal formation. Septoplasty simulation in rats results in the pathogenetic cascades onset, which, in its turn, changes the morpho-functional properties of neurons of the pyramidal layer of the hippocampus and contributes to their neuroplasticity. Activation of NMDS receptors of neurons during stress apparently, initiates two ways of neuron life - the beginning of p53 protein expression and the DN formation. Both ways can finally lead to apoptosis. CONCLUSION: The formation of dark neurons and the expression of the p53 protein in them are most likely to be interconnected and can probably provide neuroprotective mechanisms.

Dose-dependent effects of perfluorocarbon-based blood substitute on cardiac function in myocardial ischemia-reperfusion injury.

The main goal of this study was to investigate the cardioprotective properties in terms of effects on cardiodynamics of perfluorocarbon emulsion (PFE) in ex vivo-induced ischemia-reperfusion injury of an isolated rat heart. The first part of the study aimed to determine the dose of 10% perfluoroemulsion (PFE) that would show the best cardioprotective effect in rats on ex vivo-induced ischemia-reperfusion injury of an isolated rat heart. Depending on whether the animals received saline or PFE, the animals were divided into a control or experimental group. They were also grouped depending on the applied dose (8, 12, 16 ml/kg body weight) of saline or PFE. We observed the huge changes in almost all parameters in the PFE groups in comparison with IR group without any pre-treatment. Calculated in percent, dp/dt max was the most changed parameter in group treated with 8 mg/kg, while the dp/dt min, SLVP, DLVP, HR, and CF were the most changed in group treated with 16 mg/kg 10 h before ischemia. The effects of 10% PFE are more pronounced if there is a longer period of time from application to ischemia, i.e., immediate application of PFE before ischemia (1 h) gave the weakest effects on the change of cardiodynamics of isolated rat heart. Therefore, the future of PFE use is in new indications and application methods, and PFE can also be referred to as antihypoxic and antiischemic blood substitute with mild membranotropic effects.

Acute Effects of Partial Range of Motion Resistance Training and Increases in Blood Lactate Impact Accuracy of Penalty Kicks in Soccer Players.

The purpose of this investigation was to assess the acute effects of partial range of motion (pROM) exercises, on the accuracy of soccer penalty kicks on goal. This method limits the joint from moving through the complete length of a motion, creates an occlusion effect, and thus causes the type 1 muscle fibers to work anaerobically. Thirty-six soccer players, with 5-8 years of soccer playing experience, were pretested for accuracy then retested (rtt = 0.92) and divided into random groups from the Associação Banco do Brasil Futebol Clube-Group A, Paraná Futebol Clube-Group P, and Coritiba Futebol Clube-Group C. Groups were composed of 12 people performing full range of motion (fROM) exercises or pROM exercises. Both groups performed 5 sets of back squats at 50% of body weight in sets of 40 seconds with metronome tempo of 56 bpm for an average of 10-12 repetitions per 40-second set. Blood samples were collected post-warm-up, after the 3rd set, and following the 5th set for both groups, within 3-5 minutes of cessation of exercise. Athletes performing fROM exercises showed increased blood lactate from 2.69 ± 0.2 to 4.0 ± 1.2 mmol/L (p < 0.05), and in pROM, blood lactate increased from 2.48 ± 0.42 to 10.29 ± 1.3 mmol/L (p < 0.001). In fROM, accuracy decreased from 42.96 ± 13.39% to 41.37 ± 17.25% (p > 0.1), a slight decrease, while in the pROM groups, accuracy decreased from 45.42 ± 14.93% to 24.53 ± 10.2% (p < 0.001). The calculations demonstrating average percentages of accuracy are presented in the tables. These findings support that pROM exercises significantly increase blood lactate resulting in a reduction in soccer kick accuracy. This decrease in accuracy directly correlates to the accumulation of lactic acid and hydrogen ions (H+) and demonstrates that pROM strength training should not be utilized prior to a sport-specific session in order to avoid interference with the development of special skills.