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We analysed the effects of [(D-Ala⁶, Pro⁹NEt)-mGnRH+metoclopramide] i.e. Ovopel at the dose of 0.5 granule kg⁻¹ of body weight (b.w.), [(D-Arg⁶, Pro⁹NEt)-sGnRH+domperidone] i.e. Ovaprim at the dose of 0.25 ml kg⁻¹ b.w., luteinizing hormone releasing hormone (LHRHa) at the dose of 50 μg kg⁻¹ b.w. and carp pituitary extract (CPE) at the dose of 2 mg kg⁻¹ b.w. on the total volume of milt (TVM, ml), volume of milt per kg of body weight (VOM, kg⁻¹ b.w.), spermatozoa motility [%], osmolality of seminal plasma (mOsm kg⁻¹), spermatozoa concentration (×10⁹ ml⁻¹), total sperm produced (TSP, ×10⁹) and total number of spermatozoa per kg of b.w. (TNS, ×10⁹ kg⁻¹ b.w.) in the chub Leuciscus cephalus (L.). Milt was collected 24 hours after injection from individuals (n=9) belonging to each group. The control group (control, n=9) consisted of the males which were given 0.9% NaCl at 0.5 ml kg⁻¹ b.w. The highest values of TVM and VOM were observed after Ovaprim (5.88±1.62 ml and 19.24±3.56 ml kg⁻¹ b.w. respectively) and CPE stimulation (5.39±1.19 ml and 19.61±3.32 ml kg⁻¹ b.w. respectively). The lowest TVM and VOM values were observed after LHRHa injection (2.46±0.89 ml and 8.95±3.13 ml kg⁻¹ b.w. respectively) and those values were statistically different from values recorded after Ovopel (P<0.05), Ovaprim (P<0.001) and CPE (P<0.001). A significant increase in spermatozoa motility (P<0.05) was observed following hormonal stimulation as compared to the control, regardless of the type of hormonal agent applied. The values of osmolality were similar in all the groups with no significant differences between them (288–300 mOsm kg⁻¹, P>0.05). The highest spermatozoa concentrations in the control were 10.26±1.70 · 10⁹ ml⁻¹, and the lowest values were 5.47±0.99 · 10⁹ ml⁻¹, P<0.001, observed after Ovaprim stimulation. The highest TSP and TNS values were recorded after CPE injection (42.84±11.72 · 10⁹ and 160.4±65.67 · 10⁹ kg⁻¹ b.w. respectively), while the lowest were obtained following stimulation with LHRHa (23.57±8.56 · 10⁹ and 85.72±30.56 · 10⁹ kg⁻¹ b.w. respectively). Those differences were statistically significant (P<0.05). Considering the large volume of milt (TVM and VOM) and the large number of spermatozoa (TSP and TNS), chub spermation can be successfully stimulated with Ovaprim or CPE injections.
Respiratory failure coincides frequently with the occurrence of gastric ulceration. In advanced respiratory insufficiency hypoxemia is often accompanied by hypercapnia, which is the stimulus for central chemoreceptors as well as for carotid body chemoreceptors. The purpose of the work was to investigate the reflex effect of stimulation of central chemoreceptors on gastric mucosal blood flow (GMBF) in the rat. Central chemoreceptors were stimulated by a gas mixture composed of 10% carbon dioxide, 50% oxide and 40% nitrogen. In artificially ventilated and spontaneously breathing animals, the stimulation of central chemoreceptors caused a significant increase in gastric mucosal vascular resistance, accompanied by a marked decline in blood flow. We hypothesize that in patients with respiratory insufficiency accompanied by hypercapnia, the reflex impairment of GMBF may contribute to gastric ulceration.
Previous neuroimaging studies have shown that executive processes requiring planning and set-shifting [e.g. Montreal card sorting task (MCST)] may engage the dorsolateral prefrontal cortex (DLPFC) while inducing dopamine (DA) release in the striatum. However, functional imaging studies can only provide neuronal correlates of cognitive performance and cannot establish a causal relation between observed brain activity and task performance. In order to investigate the contribution of the DLPFC during set-shifting and its effect on the striatal DAergic system, we applied continuous theta burst stimulation (cTBS) to left and right DLPFC. Our aim was to transiently disrupt its function and to measure MCST performance and striatal DA release during [11C]raclopride PET. cTBS of the left DLPFC impaired MCST performance and DA release in the ipsilateral caudate–anterior putamen and contralateral caudate, as compared to cTBS of the vertex (control). These effects were limited only to left DLPFC stimulation but not right DLPFC. This is the fi rst study showing that cTBS, by disrupting left DLPFC function, may indirectly affect striatal DA release during performance of executive tasks. This cTBS-induced regional prefrontal effect and modulation of the frontostriatal network may be important for understanding the contribution of hemisphere laterality and its neural bases with regard to executive functions, as well as for revealing the neurochemical substrate underlying cognitive defi cits.
This study investigated the effects of systemic alcohol injections on respiratory activity and short-term potentiation (STP) of the phrenic nerve and hypoglossal nerve activities, evoked by electrical stimulation of the superior laryngeal nerve (SLN), in anesthetized, paralyzed, and artificially ventilated rabbits. Alcohol, in a dose of 500 mg/kg, given singly or in cumulative fractions of 100mg/kg, depressed hypoglossal activity with little or no effect on phrenic activity. SLN stimulation inhibited both phrenic and hypoglossal activities and this effect remained unchanged by either way of alcohol administration. After cessation of stimulation, hypoglossal activity increased above the control level and slowly declined to the baseline, showing signs of STP. The amplitude and duration of the hypoglossal STP decreased following a single dose of alcohol. Cumulative fractions of the alcohol dose evoked a biphasic effect on the respiratory STP. In a lower range, alcohol enhanced the hypoglossal STP and tended to increase the duration of the phrenic STP. This effect gradually declined with increasing cumulative dose of alcohol and finally reversed to the inhibition of the STP of both nerves. The results demonstrate a dose-dependent biphasic effect of alcohol on the induction and maintaining of the hypoglossal STP. A reduction in STP, together with hypoglossal activity depression following alcohol accumulation, may contribute to the facilitation of upper airway obstruction by alcohol.
Epstein-Barr virus (EBV) establishes latency in the resting memory B-cell compartment. It has been recently suggested that maintenance of chronic infection is dependent on periodic reactivation. Although the stimuli for EBV reactivation in vivo during natural infections are largely unknown, there is evidence indicating that heterologous infections could trigger herpesviruses reactivation. The purpose of this work was to identify the influence of Toll-like receptors stimulation on EBV replication in EBV latently infected Burkitt lymphoma cells (P3HR-1, Raji and Namalwa). The cells were stimulated with Pam3CSK4 (synthetic triacylated lipoprotein), PolyI:C (synthetic analog of dsRNA), LPS (lipopolysaccharide from E.coli), measles virus (MeV) and PMA (phorbol myristate acetate). Non-stimulated cells (NS) served as control. EBV expression was investigated at mRNA level for three viral lytic genes: BZLF1 (immediate early, ZEBRA), BALF2 (early, EA) and BcLF1 (late, VCA). Additionally, the effect of stimulation on NF-kBp65 and inflammatory cytokines (IL-1b, IL-6, IL-8, IL-10, IL-12p70, and TNF) was investigated. Stimulation of TLRs led to limited changes in EBV expression manifesting as increase of ZEBRA at mRNA level in cells treated with PolyI:C and Pam3CSK4. Stimulation with PolyI:C, Pam3CSK4 and LPS also lead to considerable increase of NF-kBp65, while increased levels of inflammatory cytokines were observed for IL-8, TNF and IL-6 in cells treated with PMA and MeV. In conclusion, the results of our experiments support the suggestion that TLRs stimulation with microbial ligands influences EBV virus replication.
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