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Selected AbstractsHox genes and the regulation of movement in DrosophilaDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2008Richa Dixit Abstract Many animals show regionally specialized patterns of movement along the body axis. In vertebrates, spinal networks regulate locomotion, while the brainstem controls movements of respiration and feeding. Similarly, amongst invertebrates diversification of appendages along the body axis is tied to the performance of characteristically different movements such as those required for feeding, locomotion, and respiration. Such movements require locally specialized networks of nerves and muscles. Here we use the regionally differentiated movements of larval crawling in Drosophila to investigate how the formation of a locally specialized locomotor network is genetically determined. By loss and gain of function experiments we show that particular Hox gene functions are necessary and sufficient to dictate the formation of a neuromuscular network that orchestrates the movements of peristaltic locomotion. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2008 [source] The effect of food rations on tissue-specific copper accumulation patterns of sublethal waterborne exposure in Cyprinus carpioENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2007Shodja Hashemi Abstract Common carp (Cyprinus carpio) were fed to two different food rations, 0.5% body weight (low ration [LR]) and 5% body weight (high ration [HR]), and were exposed to sublethal (1 ,M) copper levels for 28 d in softened Antwerp (Belgium) city tap water (Ca2+, 79.3 mg/L; Mg2+, 7.4 mg/L; Na+, 27.8 mg/L; pH 7.5,8.0). Copper accumulations in the liver, gills, kidney, anterior intestine, posterior intestine, and muscle were determined. Copper accumulation in the gills, liver, and kidney of LR fish was significantly higher than in HR fish. The only time copper uptake in HR fish was significantly higher than in LR fish was in the posterior intestine after two weeks of exposure. No difference was found between the two rations in the anterior intestine. Copper accumulation in the liver of both feeding treatments occurred in a time-dependent manner and did not reach steady state in any treatment. On the contrary, copper concentration in the gills reached a steady state for both HR and LR fish within the first week of exposure. No copper accumulation was found in muscle tissues of either treatment. Copper concentration dropped to control levels in all tissues, except liver tissue, two weeks after the exposure ended. Our studies indicated that copper uptake was influenced by the food ration in carp. The difference in copper accumulation probably is related to the amount of dietary NaCl and different rates of metallothionein synthesis. Low food availability provides less Na+ influx and leads to increased brachial uptake of Na+ and copper. In addition, it has been shown that starved animals show increased levels of metallothionein, possibly causing higher copper accumulation. [source] Effects of Ethanol on Cytokine Production After Surgery in a Murine Model of Gram-Negative PneumoniaALCOHOLISM, Issue 2 2008Claudia D. Spies Background:, Both alcohol abuse and surgery have been shown to impair immune function. The frequency of postoperative infectious complications is 2- to 5-fold increased in long-term alcoholic patients, leading to prolonged hospital stay. Following surgery, an increase in interleukin (IL)-6 has been shown to be associated with increased tissue injury and interleukin 1-(IL-10) is known to represent an anti-inflammatory signal. The purpose of this study was to test the hypothesis that several days of excess alcohol consumption results in more pronounced immunosuppression. We assume that alcoholic animals show increased levels of IL-10 in response to infection and increased IL-6 due to a more pronounced lung pathology. Methods:, Thirty-two female Balb/c mice were pretreated with ethanol (EtOH) at a dose of (3.8 mg/g body weight) or saline (NaCl) for 8 days. At day 8 of the experiment all mice underwent a median laparotomy. Two days postsurgery mice were either applicated 104 CFU Klebsiella pneumoniae or received sham-infection with saline. A total number of 4 groups (EtOH/K. pneumoniae; NaCl/K. pneumoniae; EtOH/Sham-infection, NaCl/Sham-infection) was investigated and a clinical score evaluated. Twenty-four hours later mice were killed; lung, spleen, and liver were excised for protein isolation and histological assessment. IL-6 and IL-10 levels were detected by ELISA. Results:, Alcohol-exposed mice exhibited a worsened clinical appearance. The histological assessment demonstrated a distinct deterioration of the pulmonary structure in alcohol-treated animals. In the lung, IL-6 and IL-10 was significantly increased in alcohol-exposed infected mice compared to saline-treated infected mice. The clinical score correlated significantly with IL-6 (r = 0.71; p < 0.01) and IL-10 levels (r = 0.64; p < 0.01) in the lung. Conclusions:, Ethanol treatment in this surgical model led to a more severe pulmonary infection with K. pneumoniae which was associated with more tissue destruction and increased levels of IL-6 and IL-10 and a worsened clinical score. [source] Liver fat and lipid oxidation in humansLIVER INTERNATIONAL, Issue 9 2009Anna Kotronen Abstract Background: Studies in animals show that changes in hepatic fatty acid oxidation alter liver fat content. Human data regarding whole-body and hepatic lipid oxidation are controversial and based on studies of only a few subjects. Aims: We examined whether whole-body and hepatic lipid oxidation are altered in subjects with non-alcoholic fatty liver disease (NAFLD) compared with controls. Methods: In vivo measurements of rates of substrate oxidation and insulin sensitivity (using the euglycaemic hyperinsulinaemic clamp technique in combination with indirect calorimetry and infusion of [3- 3H]glucose) were performed in subjects with NAFLD [mean liver fat 14.0% (interquartile range 7.5,20.5%), n=29] and in control subjects [1.6% (1.0,3.0%), n=29]. Liver fat was measured using proton magnetic resonance spectroscopy. Plasma concentrations of 3-hydroxybutyrate (3-OHB) were measured as markers of hepatic lipid oxidation. Results: In the basal state, substrate oxidation rates and serum 3-OHB concentrations were comparable in subjects with and without NAFLD. Plasma 3-OHB concentrations were similarly suppressed by insulin in both the groups. During the insulin infusion, whole-body lipid oxidation was inversely correlated with insulin-stimulated glucose disposal (r=,0.48, P<0.0001), which was lower in subjects with NAFLD [3.7±0.2 mg/(kg fat-free mass min)] than in the control subjects [5.0±0.3 mg/(kg fat-free mass min), P=0.0008]. Conclusions: Hepatic lipid oxidation is unchanged in NAFLD. Whole-body lipid oxidation is increased because of peripheral insulin resistance. These data imply that alterations in hepatic fatty acid oxidation do not contribute to liver fat content in humans. [source] Immunocytochemical mapping and quantification of expression of a putative type 1 serotonin receptor in the crayfish nervous systemTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 3 2005Nadja Spitzer Abstract Serotonin is an important neurotransmitter that is involved in modulation of sensory, motor, and higher functions in many species. In the crayfish, which has been developed as a model for nervous system function for over a century, serotonin modulates several identified circuits. Although the cellular and circuit effects of serotonin have been extensively studied, little is known about the receptors that mediate these signals. Physiological data indicate that identified crustacean cells and circuits are modulated via several different serotonin receptors. We describe the detailed immunocytochemical localization of the crustacean type 1 serotonin receptor, 5-HT1crust, throughout the crayfish nerve cord and on abdominal superficial flexor muscles. 5-HT1crust is widely distributed in somata, including those of several identified neurons, and neuropil, suggesting both synaptic and neurohormonal roles. Individual animals show very different levels of 5-HT1crust immunoreactivity (5-HT1crustir) ranging from preparations with hundreds of labeled cells per ganglion to some containing only a handful of 5-HT1crustir cells in the entire nerve cord. The interanimal variability in 5-HT1crustir is great, but individual nerve cords show a consistent level of labeling between ganglia. Quantitative RT-PCR shows that 5-HT1crust mRNA levels between animals are also variable but do not directly correlate with 5-HT1crustir levels. Although there is no correlation of 5-HT1crust expression with gender, social status, molting or feeding, dominant animals show significantly greater variability than subordinates. Functional analysis of 5-HT1crust in combination with this immunocytochemical map will aid further understanding of this receptor's role in the actions of serotonin on identified circuits and cells. J. Comp. Neurol. 484:261,282, 2005. © 2005 Wiley-Liss, Inc. [source] Ongoing activation of p53 pathway responses is a long-term consequence of radiation exposure in vivo and associates with altered macrophage activities,THE JOURNAL OF PATHOLOGY, Issue 5 2008PJ Coates Abstract The major adverse consequences of radiation exposure, including the initiation of leukaemia and other malignancies, are generally attributed to effects in the cell nucleus at the time of irradiation. However, genomic damage as a longer term consequence of radiation exposure has more recently been demonstrated due to untargeted radiation effects including delayed chromosomal instability and bystander effects. These processes, mainly studied in vitro, are characterized by un-irradiated cells demonstrating effects as though they themselves had been irradiated and have been associated with altered oxidative processes. To investigate the potential for these untargeted effects of radiation to produce delayed damaging events in vivo, we studied a well-characterized model of radiation-induced acute myeloid leukaemia in CBA/Ca mice. Haemopoietic tissues of irradiated CBA/Ca mice exhibit enhanced levels of p53 stabilization, increased levels of p21waf1, and increased amounts of apoptosis, as expected, in the first few hours post-irradiation, but also at much later times: weeks and months after the initial exposure. Because these responses are seen in cells that were not themselves directly irradiated but are the descendants of irradiated cells, the data are consistent with an initial radiation exposure leading to persistently increased levels of ongoing DNA damage, analogous to radiation-induced chromosomal instability. To investigate the potential source of ongoing oxidative processes, we show increased levels of 3-nitrotyrosine, a marker of damaging nitrogen/oxygen species in macrophages. Not all animals show increased oxidative activity or p53 responses as long-term consequences of irradiation, but increased levels of p53, p21, and apoptosis are directly correlated with increased 3-nitrotyrosine in individual mice post-irradiation. The data implicate persistent activation of inflammatory-type responses in irradiated tissues as a contributory bystander mechanism for causing delayed DNA damage. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] | |||||||||||||