https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:15167 Wed 11 Apr 2018 16:01:18 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:13941 Wed 11 Apr 2018 12:46:06 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34069 in vivo preparation and patch-clamp electrophysiology to test whether the synaptic and intrinsic properties of superficial dorsal horn (SDH) neurons are altered 5 days after the induction of mild colitis in adult male mice (i.e. during acute inflammation of the colon). Whole-cell recordings were made from lumbosacral (L6-S1) superficial dorsal horn neurons (SDH), in animals under isoflurane anesthesia. Noxious colorectal distension (CRD) was used to identify SDH neurons with colonic inputs, while stimulation of the hind paw and tail was employed to assess convergent cutaneous input. Following inflammation, a significantly increased proportion of SDH neurons received both colonic and cutaneous inputs, compared to neurons in naïve animals. In addition, the nature and magnitude of responses to CRD and cutaneous stimulation differed in inflamed animals, as was spontaneous excitatory synaptic drive. Conversely, several measures of intrinsic excitability were altered in a manner that would decrease SDH network excitability following colitis. We propose that during inflammation, sensitization of colonic afferents results in increased signaling to the SDH. This is accompanied by plasticity in SDH neurons whereby their intrinsic properties are changed to compensate for altered afferent activity.]]> Wed 06 Feb 2019 09:51:23 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:38579 in vitro lovastatin release from the alginate/chitosan/lovastatin nanoparticles under different conditions, including different alginate/chitosan ratios, different solution pH values and different lovastatin contents, were carried out by ultraviolet-visible spectroscopy. The rate of drug release from the nanoparticles is proportional to the increase in the solution pH and inversely proportional to the content of the loaded lovastatin. The drug release process is divided into two stages: a rapid stage over the first 10 hr, then the release becomes gradual and stable. The Korsmeyer-Peppas model is most suitable for the lovastatin release process from the alginate/chitosan/lovastatin nanoparticles in the first stage, and then the drug release complies with other models depending on solution pH in the slow release stage. In addition, the toxicity of alginate/chitosan/lovastatin (abbreviated ACL) nanoparticles was sufficiently low in mice in the acute toxicity test. The LD₅₀ of the drug was higher than 5000 mg/kg, while in the subchronic toxicity test with treatments of 100 mg/kg and 300 mg/kg ACL nanoparticles, there were no abnormal signs, mortality, or toxicity in general to the function or structure of the crucial organs. The results show that the ACL nanoparticles are safe in mice and that these composite nanoparticles might be useful as a new drug carrier.]]> Tue 09 Nov 2021 15:27:06 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34599 Tue 02 Apr 2019 11:41:10 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:643 Thu 25 Jul 2013 09:10:36 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20802 h1 differentiator and leukocyte activator. Ample studies showed suppression of IL-12 production by numerous stress factors, including prostaglandins, catecholamines, glucocorticoids, and opioids, but did so in vitro and in the context of artificial leukocyte activation, not simulating the in vivo setting. In a recent study we reported in vivo suppression of plasma IL-12 levels by behavioral stress and surgery. The current study aims to elucidate neuroendocrine mechanisms underlying this phenomenon in naïve F344 rats. To this end, both adrenalectomy and administration of specific antagonists were used, targeting the aforementioned stress factors. The results indicated that corticosterone and prostaglandins are prominent mediators of the IL-12-suppressing effects of stress and surgery, apparently through directly suppressing leukocyte IL-12 production. Following surgery, endogenous prostaglandins exerted their effects mainly through elevating corticosterone levels. Importantly, stress-induced release of epinephrine or opioids had no impact on plasma IL-12 levels, while pharmacological administration of epinephrine reduced plasma IL-12 levels by elevating corticosterone levels. Last, a whole blood in vitro study indicated that prostaglandins and corticosterone, but not epinephrine, suppressed IL-12 production in non-stimulated leukocytes, and only corticosterone did so in the context of CpG-C-induced IL-12 production. Overall, the findings reiterate the notion that results from in vitro or pharmacological in vivo studies cannot indicate the effects of endogenously released stress hormones under stress/surgery conditions. Herein, corticosterone and prostaglandins, but not catecholamines or opioids, were key mediators of the suppressive effect of stress and surgery on in vivo plasma IL-12 levels in otherwise naïve animals.]]> Sat 24 Mar 2018 08:05:52 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27553 Sat 24 Mar 2018 07:33:15 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:28008 Sat 24 Mar 2018 07:27:19 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27596 Sat 24 Mar 2018 07:25:16 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:23659 Sat 24 Mar 2018 07:16:51 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22170 H1 differentiation. In vitro studies indicated suppression of IL-12 production by several stress-related factors, but no effects of behavioral stress were shown on plasma IL-12 levels. Therefore, in the current study we (i) examined the in vivo effects of various behavioral and pharmacological stress paradigms on baseline plasma IL-12 levels; (ii) compared these in vivo findings to those obtained following in vitro stimulation of leukocytes from the same rats; and (iii) assessed potential sexual dimorphism in these outcomes. The findings indicated that plasma IL-12 levels were significantly reduced by social confrontation, wet-cage exposure, surgery, and the administration of corticosterone, epinephrine, or prostaglandin-E₂. Notably, most in vivo impacts on plasma levels were not evident when assessed in vitro. The IL-12-reducing effects of wet-cage exposure, and of corticosterone and epinephrine administration, were significantly greater in males than in females, although females exhibited greater total corticosterone levels following stress. The duration of acute stressors predicted the degree of IL-12 reduction, but more prolonged stressors did not. Furthermore, seven days of alternating behavioral stressors reduced plasma IL-12 levels more than 14 days. These findings suggest animals’ behavioral habituation to stress conditions, or a specific immune mechanism restricting the duration of IL-12 reduction. Overall, our findings indicate a generic and robust stress-induced reduction in plasma IL-12 levels, and suggest epinephrine, corticosterone, and prostaglandin-E₂, as potential mediators that should be scrutinized in vivo in the context of natural physiological stress responses.]]> Sat 24 Mar 2018 07:14:58 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:43031 Mon 12 Sep 2022 11:35:20 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:30630 1H-MRS) and localization techniques principles, different fast MRSI techniques will be discussed from their initial development to the recent innovations with particular emphasis on their capacity to record neurochemical changes in the brain in a variety of pathologies. The clinical applications of whole brain fast spectroscopic techniques, can assist in the assessment of neurochemical changes in the human brain and help in understanding the roles they play in disease. To give a good example of the utilities of these techniques in clinical context, MRSI application in multiple sclerosis was chosen. The available up to date and relevant literature is discussed and an outline of future research is presented.]]> Mon 11 Mar 2019 12:08:59 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:36204 Mon 02 Mar 2020 13:51:01 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46117 10,000 mg/kg. The comparison of Pb minerals prior to and after in vitro extractions demonstrated that the relatively soluble forms of Pb (PbSO4, PbO2 and MgO Pb) start to dissolve than other forms of Pb minerals, suggesting there was no difference in Pb2+ release between chemical-based (RBALP) and physiologically-based (UBM) models. The identification of the Pb minerals of Pb5(PO4)3Cl and organically-complexed Pb in mice excreta demonstrated that a portion of Pb2+ combined with food and humic acid to generate organically-complexed Pb in mice excreta, and that Pb5(PO4)3Cl is not bioavailable.]]> Fri 11 Nov 2022 14:46:52 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35882 Fri 10 Jan 2020 10:06:23 AEDT ]]>