39 resultados para Disorders of the nervous system


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The mud crab, Scylla olivacea, is one of the most economically valuable marine species in Southeast Asian countries. However, commercial cultivation is disadvantaged by reduced reproductive capacity in captivity. Therefore, an understanding of the general and detailed anatomy of central nervous system (CNS) is required before investigating the distribution and functions of neurotransmitters, neurohormones, and other biomolecules, involved with reproduction. We found that the anatomical structure of the brain is similar to other crabs. However, the ventral nerve cord (VNC) is unlike other caridian and dendrobrachiate decapods, as the subesophageal (SEG), thoracic and abdominal ganglia are fused, due to the reduction of abdominal segments and the tail. Neurons in clusters within the CNS varied in sizes, and we found that there were five distinct size classes (i.e., very small globuli, small, medium, large, and giant). Clusters in the brain and SEG contained mainly very small globuli and small-sized neurons, whereas, the VNC contained small-, medium-, large-, and giant-sized neurons. We postulate that the different sized neurons are involved in different functions. Microsc. Res. Tech. 77:189–200, 2014. © 2013 Wiley Periodicals, Inc.

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Glutathione (GSH) has a crucial role in cellular signaling and antioxidant defenses either by reacting directly with reactive oxygen or nitrogen species or by acting as an essential cofactor for GSH S-transferases and glutathione peroxidases. GSH acting in concert with its dependent enzymes, known as the glutathione system, is responsible for the detoxification of reactive oxygen and nitrogen species (ROS/RNS) and electrophiles produced by xenobiotics. Adequate levels of GSH are essential for the optimal functioning of the immune system in general and T cell activation and differentiation in particular. GSH is a ubiquitous regulator of the cell cycle per se. GSH also has crucial functions in the brain as an antioxidant, neuromodulator, neurotransmitter, and enabler of neuron survival. Depletion of GSH leads to exacerbation of damage by oxidative and nitrosative stress; hypernitrosylation; increased levels of proinflammatory mediators and inflammatory potential; dysfunctions of intracellular signaling networks, e.g., p53, nuclear factor-κB, and Janus kinases; decreased cell proliferation and DNA synthesis; inactivation of complex I of the electron transport chain; activation of cytochrome c and the apoptotic machinery; blockade of the methionine cycle; and compromised epigenetic regulation of gene expression. As such, GSH depletion has marked consequences for the homeostatic control of the immune system, oxidative and nitrosative stress (O&NS) pathways, regulation of energy production, and mitochondrial survival as well. GSH depletion and concomitant increase in O&NS and mitochondrial dysfunctions play a role in the pathophysiology of diverse neuroimmune disorders, including depression, myalgic encephalomyelitis/chronic fatigue syndrome and Parkinson’s disease, suggesting that depleted GSH is an integral part of these diseases. Therapeutical interventions that aim to increase GSH concentrations in vivo include N-acetyl cysteine; Nrf-2 activation via hyperbaric oxygen therapy; dimethyl fumarate; phytochemicals, including curcumin, resveratrol, and cinnamon; and folate supplementation.

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Natriuretic peptides (NPs) are regulatory molecules that cause cGMP-mediated diuresis and natriuresis in mammals. Accordingly, it is interesting to consider their role in desert-adapted animals in which water is often limited. This study investigated the response of the natriuretic peptide (NP) system to varying periods of water deprivation (WD) in the Australian desert rodent species, Notomys alexis. It was hypothesised that the expression of the NP system will be down-regulated in water-deprived N. alexis compared to water-replete animals. The plasma levels of ANP were significantly reduced after 3 days of WD, but were unaffected by 7, 14 and 28 days of WD. Water deprivation for 3, 7, 14 days had a variable effect on the mRNA expression of ANP, CNP, NPR-A, NPR-B, and NPR-C, and a uniform down-regulation was not observed. However, after 28 days of WD, mRNA expression was similar to water-replete animals, except for NPR-A. Surprisingly, 7 and 14 days of WD caused an up-regulation in the ability of ANP to stimulate cGMP; this also occurred at 14 days for CNP. Taken together, the mRNA expression and peptide mediated guanylyl cyclase activity data after WD were in the opposite direction to what was predicted. Interestingly, after 28 days of WD, most parameters were similar to those of water-replete animals, which indicates that a down-regulation of the NP system is not part of the physiological response to an absence of free water in N. alexis.

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There is evidence that levels of adipose tissue can influence responses of the hypothalamopituitary-adrenal (HPA) axis to stress in humans and rats but this has not been explored in sheep. Also, little is known about the sympathoadrenal responses to stress in individuals with relatively different levels of adipose tissue. We tested the hypothesis that the stress-induced activation of the HPA axis and sympathoadrenal system is lower in ovariectomized ewes with low levels of body fat (lean) than ovariectomized ewes with high levels of body fat (fat). Ewes underwent dietary manipulation for 3 months to yield a group of lean ewes (n = 7) with a mean (±SEM) live weight of 39.1 ± 0.9 kg and body fat of 8.9 ± 0.6% and fat ewes (n = 7) with a mean (±SEM) live weight of 69.0 ± 1.8 kg and body fat of 31.7 ± 3.4%. Fat ewes also had higher circulating concentrations of leptin than lean ewes. Blood samples were collected every 15 min over 8 h when no stress was imposed (control day) and on a separate day when 4 h of isolation/restraint was imposed after 4 h of pretreatment sampling (stress day). Plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol, epinephrine and norepinephrine did not change significantly over the control day and did not differ between lean and fat ewes. Stress did not affect plasma leptin levels. All stress hormones increased significantly during isolation/restraint stress. The ACTH, cortisol and epinephrine responses were greater in fat ewes than lean ewes but norepinephrine responses were similar. Our results suggest that relative levels of adipose tissue influence the stress-induced activity of the hypothalamopituitary-adrenal axis and some aspects of the sympathoadrenal system with fat animals having higher responses than lean animals.

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Physical stressors such as infection, inflammation and tissue injury elicit activation of the hypofhalamic-pituitary-adrenal (HPA) axis. This response has significant implications for both immune and central nervous system function. Investigations in rats into the neural substrates responsible for HPA axis activation to an immune challenge have predominantly utilized an experimental paradigm involving the acute administration of the pro-inflammatory cytokine interleukin-1 β (IL-1β). It is well recognized that medial parvocellular corticotrophin-releasing factor cells of the paraventricular nucleus (mPVN CRF) are critical in generating HPA axis responses to an immune challenge but little is known about how peripheral immune signals can activate and/or modulate the mPVN CRF cells. Studies that have examined the afferent control of the mPVN CRF cell response to systemic IL-1β have centred largely on the inputs from brainstem catecholamine cells. However, other regulatory neuronal populations also merit attention and one such region is a component of the limbic system, the central nucleus of the amygdala (CeA). A large number of CeA cells are recruited following systemic IL-lβ administration and there is a significant body of work indicating that the CeA can influence HPA axis function. However, the contribution of the CeA to HPA axis responses to an immune challenge is only just beginning to be addressed. This review examines three aspects of HPA axis control by systemic IL-lβ; (i) whether the CeA has a role in generating HPA axis responses to systemic IL-1 β, (ii) the identity of the neural connections between the CeA and mPVN CRF cells that might be important to HPA axis responses and (iii) the mechanisms by which systemic IL-lβ triggers the recruitment of CeA cells.

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Metal homoeostasis in cyanobacteria is based on uptake and export systems that are controlled by their own regulators. This study characterises the zinc uptake (Znu) system in Nostoc punctiforme. The system was found to comprise of three subunits in an ACB operon: a Zn2+-binding protein (ZnuA18), a transmembrane domain (ZnuB) and an ATPase (ZnuC). These proteins are encoded within the znu operon regulated by a zinc uptake transcription repressor (Zur). Interestingly, a second Zn2+-binding protein (ZnuA08) was also identified at a distal genomic location. Interactions between components of the ZnuACB system were investigated using knockouts of the individual genes. The znuA08-, znuA18-, znuB- and znuC- mutants displayed overall reduced znuACB transcript levels, suggesting that all system components are required for normal expression of znu genes. Zinc uptake assays in the Zn2+-binding protein mutant strains showed that the disruption of znuA18 had a greater negative effect on zinc uptake than disruption of znuA08. Complementation studies in Escherichia coli indicated that both znuA08 and znuA18 were able to restore zinc uptake in a znuA- mutant, with znuA18 permitting the highest zinc uptake rate. The N. punctiforme zur was also able to complement the E. coli zur- mutant.

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Immobility plus preexisting chronic disease or acute trauma can activate the coagulation system, thus increasing the risk for thromboembolic events. The effects of long-term bed-rest immobility and microgravity on the coagulation system of healthy persons (e.g., during crewed Mars missions) have not yet been studied. The main objective of the second Berlin BedRest Study (BBR2-2) "Coagulation Part" was to investigate adaptations of the hemostatic system during long-term bed rest (60 days) under simulated microgravity (6° head-down-tilt [6°HDT]) and after mobilization in three different volunteer groups (randomly assigned to CTR= inactive control group; RE= resistive exercise only group; and RVE= resistive exercise with whole-body vibration group). In 24 males (aged 21-45 years), before, during, and after long-term bed rest, key parameters of coagulation were measured from venous blood samples: D-dimer (DD), thrombin-antithrombin III complex (TAT), and prothrombin fragment F1 + 2 (PT-F1 + 2). Additionally, modified rotational thrombelastometry (ROTEM (®) ) analysis was performed. Times of exploratory analyses were as follows: baseline data collection 2 days before bed rest (BDC-2); eight different days of 6°HDT bed rest (HDT1-HDT60), and two different days after reambulation (R + 3 and R + 6). We found significant changes in DD, TAT, and PT-F1 + 2 over the total time course, but no consistent effect of physical interventions (RE, RVE) on these parameters. Notably, no parameter reached levels indicative of intravascular thrombin formation. All ROTEM® parameters remained within the normal range and no pathological traces were found. Sixty days of 6°HDT bed rest are not associated with pronounced activation of the coagulation system indicative of intravascular thrombus formation in healthy volunteers independent of the training type during the bed rest.

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 This thesis provides evidence of central nervous system adaptations as well as reduced exercising haemodynamics and perceptual responses when light-load resistance exercise/training is performed with blood flow restriction. In addition, this type of training appears beneficial in order to target gains in strength and muscle mass in healthy young populations.

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Digestive juice from the herbivorous gecarcinid land crabs Gecarcoidea natalis and Discoplax hirtipes exhibited total cellulase activity and activities of two cellulase enzymes; endo-ß-1,4-glucanase and ß-1,4-glucosidase. These enzymes hydrolysed native cellulose to glucose. The digestive juice of both species also contained laminarinase, licheninase and xylanase, which hydrolysed laminarin, lichenin and xylan, respectively, to component sugars. The pH optima of ß-1,4-glucosidase, endo-ß-1,4-glucanase and total cellulase from G. natalis were 4–5.5, 5.5 and 5.5–7, respectively. In the digestive juice from D. hirtipes, the corresponding values were 4–7, 5.5–7 and 4–9, respectively. The pH of the digestive juice was 6.69±0.03 for G. natalis and 6.03±0.04 for D. hirtipes and it is likely that the cellulases operate near maximally in vivo. In G. natalis, total cellulase activity and endo-ß-1,4-glucanase activity were higher than in D. hirtipes, and the former species can thus hydrolyse cellulose more rapidly. ß-1,4-glucosidase from G. natalis was inhibited less by glucono-D-lactone (Ki=11.12 mmol l-1) than was the ß-1,4-glucosidase from D. hirtipes (Ki=4.53 mmol l-1). The greater resistance to inhibition by the ß-1,4-glucosidase from G. natalis may contribute to the efficiency of the cellulase system in vivo by counteracting the effects of product inhibition and possibly dietary tannins. The activity of ß-1,4-glucosidase in the digestive juice of D. hirtipes was higher than that of G. natalis.

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As obesity prevention becomes an increasing health priority in many countries, including Australia
and New Zealand, the challenge that governments are now facing is how to adopt a systematic
policy approach to increase healthy eating and regular physical activity. This article sets out a
structure for systematically identifying areas for obesity prevention policy action across the food
system and full range of physical activity environments. Areas amenable to policy intervention can
be systematically identified by considering policy opportunities for each level of governance (local,
state, national, international and organisational) in each sector of the food system (primary
production, food processing, distribution, marketing, retail, catering and food service) and each
sector that influences physical activity environments (infrastructure and planning, education,
employment, transport, sport and recreation). Analysis grids are used to illustrate, in a structured
fashion, the broad array of areas amenable to legal and regulatory intervention across all levels of
governance and all relevant sectors. In the Australian context, potential regulatory policy
intervention areas are widespread throughout the food system, e.g., land-use zoning (primary
production within local government), food safety (food processing within state government), food
labelling (retail within national government). Policy areas for influencing physical activity are
predominantly local and state government responsibilities including, for example, walking and
cycling environments (infrastructure and planning sector) and physical activity education in schools
(education sector). The analysis structure presented in this article provides a tool to systematically
identify policy gaps, barriers and opportunities for obesity prevention, as part of the process of
developing and implementing a comprehensive obesity prevention strategy. It also serves to
highlight the need for a coordinated approach to policy development and implementation across
all levels of government in order to ensure complementary policy action.

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Background There has been a Human Volunteer Programme at the British chemical weapons research facility at Porton Down since the First World War, in which some of the participants were exposed to chemical warfare agents.

Aim To identify any striking specific morbidity patterns in members of the Porton Down Veterans Support Group (PDVSG).

Methods A self-completed postal questionnaire was prepared including health immediately after the visits to Porton Down, subsequent diagnoses and hospital admissions, symptoms in, and after, the first 5 years after the visits, fatigue symptoms and current quality of life, measured using the SF-36.

Results Responses were received from 289 of 436 (66%). Results reported here relate to 269 male respondents of mean age 66.8 years. Sixty-six per cent reported their first visit to Porton Down in the 1950s. The most common diagnoses or hospital admissions reported were diseases of the circulatory system. In the first 5 years after their visits the most common symptoms were headache, irritability or outbursts of anger and feeling un-refreshed after sleep. In the later period, most common symptoms were fatigue, feeling un-refreshed after sleep and sleeping difficulties. Sixty-five per cent met the definition for a case of ‘fatigue’. Current quality of life dimensions were consistently lower than age-specific estimates from general population samples.

Conclusions Members of the PDVSG responding to this survey reported poorer quality of life than the general population. Despite there being no clear pattern of specific morbidities, we cannot rule out ill-health being potentially associated with past experience at Porton Down

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Research conducted in Australia and around the world in the last decade has shown that people with significant intellectual impairments are over-represented in all areas of the criminal justice system. They are particularly over-represented in remand populations appearing before court. Previous research has suggested that as many as one-quarter of offenders facing sentencing in court have difficulty in understanding court procedures and it is suspected that a majority of these individuals suffer a significant intellectual impairment. The purpose of this study was to establish whether remandees with significant intellectual impairments (IQ < 70) have an accurate understanding of the court system. Seventy-four remand prisoners took part in the study. Remandees with an IQ of less than 70 demonstrated a significantly poorer understanding of the court system than those remandees with an IQ of 70 and above. The implications of these results are discussed in relation to the need for law reform and diversionary practices for this population of remandees.

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The idea of combining photovoltaic and solar thermal collectors (PVT collectors) to provide electrical and heat energy is not new, however it is an area that has received only limited attention. With concern growing over energy sources and their usage, PVTs have become an area receiving more attention. Although PVTs are not as prevalent as solar thermal systems, the integration of photovoltaic and solar thermal collectors into the walls or roofing structure of a building could provide greater opportunity for the use of renewable solar energy technologies in domestic, commercial and industrial applications. As such, the design of a novel building integrated photovoltaic/thermal (BIPVT) solar collector is theoretically analysed through the use of a modified Hottel-Whillier model. The thermal and electrical efficiency under a range of conditions are subsequently determined and results showing how key design parameters influence the performance of the BIPVT system are presented.

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Computer simulations of Stockmayer fluids were performed to generate dipole time correlation functions (TCF) at three temperatures and three dipole moments in both the microcanonical and canonical ensembles. The effect of Nosé constant-temperature dynamics on time-dependent quantities is discussed, and empirical results are given to show that the choice of thermal inertia parameter influences the speed with which a system moves through its phase space. The time correlation functions from the simulations were analyzed in terms of current theories for dipolar systems. A functional form is proposed to cover both the longtime and short-time behavior of the time correlation functions of dipoles. The relationship between this functional form and the dielectric function of the Stockmayer system is also discussed.

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Lithostratigraphy, biostratigraphy of the Ordovician Xainza area, northern division and correlation divided of approximates of the early as of Ordovician of Tetragraptus (Paratetragraptus)-Didymograptus (Corymbograptus) deflexus combination of Middle Ordovician Michelinoceras elongatum- combination with Sinoceras chinese and the Late Ordovician Michelinoceras huangnigang-Columenoceras priscum combination band. Early Ordovician strata author from 2000 to 2001 making Xainza County Sheet 1:250000 regional geological survey newly discovered, is the oldest strata of reliable fossils based in northern Tibet. Especially Tetragraptus (Paratetragraptus) approximatus discovery, not only to expand the distribution of it in our geographic area Early Ordovician strata the similar stratigraphic correlation international biological basis.

The paper deals with the classification and correlation of lithostratigraphy and biostratigraphy of the Ordovician System in the Xainza region, North Tibet. Based on fossils, the Ordovician System is divided into several biozones as follows: Tetragraptus (Paratetragraptus) approximatus Didymograptus (Corymbograptus) deflexus graptolite assemblage of Early Ordovician, The sediments of Early Ordovician is discovered recently by authors during 2000~2001 when making the geological surveying 1:250000 scale of Xainza county, Which has been the oldest stratum based on fossils up to now in northern Tibet. What is more, the discovery of Tetragraptus (Paratetragraptus) approximatus enlarges its geographical distribution in our nation as well as provides biology evidence to international correlation of the Ordovician in Xainza county.