Liver fat metabolism, obesity and diabetes in Psammomys obesis

Defects in fat metabolism are central to the aetiology and pathogenesis of obesity and type II diabetes. The liver plays a central role in these disease states via its regulation of glucose and fat metabolism. In addition, accumulation of fat within the liver has been associated with changes in key pathways of carbohydrate and fat metabolism. However a number of questions remain. It is hypothesised that fat accumulation within the liver is a primary defect in the aetiology and pathogenesis of obesity and type II diabetes. Fat accumulating in the liver is the result of changes in the gene expression of key enzymes and proteins involved with fat uptake, fat transport, fat oxidation, fat re-esterification or storage and export of fat from the liver and these changes are regulated by key lipid responsive transcription factors. To study these questions Psammomys obesus was utilised. This polygenic rodent model of obesity and type II diabetes develops obesity and diabetes in a similar pattern to susceptible human populations. In addition dietary and environmental changes to Psammomys obesus were employed to create different states of energy balance, which allowed the regulation of liver fat gene expression to be examined. These investigations include: 1) Measurement of fat accumulation and fatty acid binding proteins in lean, obese and diabetic Psammomys obesus. 2) Characterisation of hepatic lipid enzymes, transport protein and lipid responsive transcription factor gene expression in lean, obese and diabetic Paammomys obesus. 3) The effect of acute and chronic energy restriction on hepatic lipid metabolism in Psammomys obesus. 4) The effect of sucrose feeding on the development of obesity and type II diabetes in Psammomys obesus. 5) The effect of nicotine treatment in lean and obese Psammomys obesus, 6) The effect of high dose leptin administration on hepatic fat metabolism in Psammomys obesus. The results of these studies demonstrated that fat accumulation within the liver was not a primary defect in the aetiology and pathogenesis of obesity and type II diabetes. Fat accumulating in the liver was not the result of changes in the gene expression of key enzymes and proteins involved in hepatic fat metabolism. However changes in the mRNA level of the transcription factors PPAR∝ and SREBP-1C was associated with the development of diabetes and the gene expression of these two transcription factors was associated with changes in diabetic status

Transcriptional regulation of sonic hedgehog target genes in the mammalian limb

The Hedgehog (HH) family of secreted proteins are critical regulators of embryonic development. Dysregulation of the HH pathway results in a large class of developmental defects as well as several types of cancer. HH signaling elicits a transcriptional response by regulating GLI transcription factors. The mechanisms by which GLIs activate and sustain gene expression in response to HH are not well understood. To address this in the limb, we undertook a systems level analysis to determine the spatiotemporal kinetics of the GLI transcriptional response. In addition, we focus on the regulation of a single GLI-bound cis-regulatory module (CRM) associated with the GLI target gene, Gremlin. And lastly, we establish a primary limb cell culture method that can be utilized in a medium throughput manner to manipulate gene expression and test the activity of DNA elements. This work provides the first characterization of the spatiotemporal response of a large group of GLI target genes. Furthermore, this work lays the foundation for a systems-level understanding of the gene regulatory networks underlying SHH-mediated limb patterning.Cellular and Molecular Biolog

Rapid bioassay-guided screening of toxic substances in vegetable oils that shorten the life of SHRSP rats

It has been consistently reported that vegetable oils including canola oil have a life shortening effect in Stroke-Prone Spontaneously Hypertensive Rats (SHRSP) and this toxic effect is not due to the fatty acid composition of the oil. Although it is possible that the phytosterol content or type of phytosterol present in vegetable oils may play some role in the life shortening effect observed in SHRSP rats this is still not completely resolved. Furthermore supercritical CO2 fractionation of canola oil with subsequent testing in SHRSP rats identified safe and toxic fractions however, the compounds responsible for life shortening effect were not characterised. The conventional approach to screen toxic substances in oils using rats takes more than six months and involves large number of animals. In this article we describe how rapid bioassay-guided screening could be used to identify toxic substances derived from vegetable oils and/or processed foods fortified with vegetable oils. The technique incorporates sequential fractionation of oils/processed foods and subsequent treatment of human cell lines that can be used in place of animal studies to determine cytotoxicity of the fractions with structural elucidation of compounds of interest determined via HPLC-MS and GC-MS. The rapid bioassay-guided screening proposed would require two weeks to test multiple fractions from oils, compared with six months if animal experiments were used to screen toxic effects. Fractionation of oil before bio-assay enhances the effectiveness of the detection of active compounds as fractionation increases the relative concentration of minor components

Eicosapentaenoic acid and oxypurinol in the treatment of muscle wasting in a mouse model of cancer cachexia

Cancer cachexia is a wasting condition, driven by systemic inflammation and oxidative stress. This study investigated eicosapentaenoic acid (EPA) in combination with oxypurinol as a treatment in a mouse model of cancer cachexia. Mice with cancer cachexia were randomized into 4 treatment groups (EPA (0.4 g/kg/day), oxypurinol (1 mmol/L ad-lib), combination, or control), and euthanized after 29 days. Analysis of oxidative damage to DNA, mRNA analysis of pro-oxidant, antioxidant and proteolytic pathway components, along with enzyme activity of pro- and antioxidants were completed on gastrocnemius muscle. The control group displayed earlier onset of tumor compared to EPA and oxypurinol groups (P&lt;0.001). The EPA group maintained body weight for an extended duration (20 days) compared to the oxypurinol (5 days) and combination (8 days) groups (P&lt;0.05). EPA (18.2&plusmn;3.2 pg/ml) and combination (18.4&plusmn;3.7 pg/ml) groups had significantly higher 8-OH-dG levels than the control group (12.9&plusmn;1.4 pg/ml, P&le;0.05) indicating increased oxidative damage to DNA. mRNA levels of GPx1, MURF1 and MAFbx were higher following EPA treatment compared to control (P&le;0.05). Whereas oxypurinol was associated with higher GPx1, MnSOD, CAT, XDH, MURF1, MAFbx and UbB mRNA compared to control (P&le;0.05). Activity of total SOD was higher in the oxypurinol group (32.2&plusmn;1.5 U/ml) compared to control (27.0&plusmn;1.3 U/ml, P&lt;0.01), GPx activity was lower in the EPA group (8.76&plusmn;2.0 U/ml) compared to control (14.0&plusmn;1.9 U/ml, P&lt;0.05), and catalase activity was lower in the combination group (14.4&plusmn;2.8 U/ml) compared to control (20.9&plusmn;2.0 U/ml, P&lt;0.01). There was no change in XO activity. The increased rate of weight decline in mice treated with oxypurinol indicates that XO may play a protective role during the progression of cancer cachexia, and its inhibition is detrimental to outcomes. In combination with EPA, there was little significant improvement from control, indicating oxypurinol is unlikely to be a viable treatment compound in cancer cachexia.<br /

CoQ10 conveys protection from oxidative stress in plasma but not skeletal muscle

Coenzyme Q10 (CoQ10) is commonly consumed as an antiaging supplement at doses of 30&ndash;210 mg/day. The aim of the study was to determine if CoQ10 alters markers of antioxidant status, oxidative damage, and gene expression in aging skeletal muscle. Female guinea pigs aged 26 months were supplemented for 6 weeks with CoQ10 at a human equivalent dose of 10 mg/kg/day. Body weight, plasma CoQ10 concentration, and WBC DNA abasic sites were measured at weeks 0, 2, 4, and 6 of the supplementation period. At the end of supplementation, concentrations of skeletal muscle CoQ10, glutathione, malondialdehyde, protein carbonyls, DNA abasic sites, activities of catalase and glutathione peroxidase, and the gene expression of cyctochrome c oxidase subunits were measured. Dietary supplementation with CoQ10 elevated plasma CoQ10 levels (pre 73 &plusmn; 3 nmol/L, post 581 &plusmn; 15 nmol/L, P &lt; 0.05) and decreased abasic sites in WBC DNA (pre 16.8 &plusmn; 0.5 Ap/100000 bp, post 9.7 &plusmn; 0.4 Ap/100000 bp, P &lt; 0.05). In contrast, all of the measures made in skeletal muscle were not different between groups (P &gt; 0.05). These results indicate that dietary supplementation with CoQ10 at a dose of 10 mg/kg/day may be capable of increasing antioxidant protection and reducing oxidative damage in the plasma, but may have no effect in skeletal muscle.<br /

Cholinesterase Research Outreach Project (CROP): measuring cholinesterase activity and pesticide use in an agricultural community

BACKGROUND: Australian farmers and their workers are exposed to a wide variety of pesticides. Organophosphate (OP) insecticides are a widely used class of pesticide used for animal husbandry practices (Naphthalophos for sheep dipping, jetting and drench), crop production for pest control (Dimethoate) and in public health (Maldison for head lice). Acute poisonings with this class of insecticide are reported among agricultural workers and children around the globe, due to the inhibition of acetylcholinesterase (AChE). Less is known about chronic exposures. Regular monitoring of erythrocyte AChE will enable farmers to identify potential exposure to organophosphate insecticides and take action to reduce exposures and improve their health and safety practices. This study aims to assess and improve the integration of AChE monitoring into routine point of care health clinics, and provide farming and non-farming people with a link between their AChE activity and their household chemical and agrichemical use. METHODS/DESIGN: The research will target individuals who work on mixed farming enterprises and routinely using OPs (n&thinsp;=&thinsp;50) and non-farmers (n&thinsp;=&thinsp;30). Baseline data are collected regarding demographic, health conditions and behaviours, Kessler 10 (K10) scores, chemical use and personal protection. Baseline anthropometric measures include height, weight, hip and waist circumference, body fat analysis and, biochemical analysis of fasted total serum cholesterol, triglycerides, low-density cholesterol (LDL), high-density cholesterol (HDL) and blood glucose. Analysis of erythrocyte cholinesterase (EAChE) activity is also conducted using a finger prick test. Testing of EAChE is then repeated in all participants every 3&nbsp;weeks for a maximum of three times over a period 10&nbsp;weeks. Participants are provided with full feedback and counselling about their EAChE activity after each reading and a detailed summary provided to all participants at the completion of the study. Data will be analysed using repeated measures within a general linear model. DISCUSSION: This work will provide an evidence base and recommendations for the integration of EAChE monitoring into Australian rural health clinics, leading to research which will further quantify pesticide exposure both on the farm and in the home, highlighting the importance of sustaining and providing a safe work and home environment for farming communities. TRIAL REGISTRATION: ACTRN12613001256763

Stirling System Modeling for Space Nuclear Power Systems

A dynamic model of a high-power Stirling convertor has been developed for space nuclear power systems modeling. The model is based on the Component Test Power Convertor (CTPC), a 12.5-kWe free-piston Stirling convertor. The model includes the fluid heat source, the Stirling convertor, output power and heat rejection. The Stirling convertor model includes the Stirling cycle thermodynamics, heat flow, mechanical mass-spring damper systems, and the linear alternator. The model was validated against test data. Both nonlinear and linear versions of the model were developed. The linear version algebraically couples two separate linear dynamic models; one model of the Stirling cycle and one model of the thermal system, through the pressure factors. Future possible uses of the Stirling system dynamic model are discussed. A pair of commercially available 1-kWe Stirling convertors is being purchased by NASA Glenn Research Center. The specifications of those convertors may eventually be incorporated into the dynamic model and analysis compared to the convertor test data. Subsequent potential testing could include integrating the convertors into a pumped liquid metal hot-end interface. This test would provide more data for comparison to the dynamic model analysis

The effect of short-term canola oil ingestion on oxidative stress in the vasculature of stroke-prone spontaneously hypertensive rats

Background: This study aimed to determine if 25 days of canola oil intake in the absence of excess dietary salt or together with salt loading affects antioxidant and oxidative stress markers in the circulation. A further aim was to determine the mRNA expression of NADPH oxidase subunits and superoxide dismutase (SOD) isoforms in the aorta of stroke-prone spontaneously hypertensive (SHRSP) rats.Methods: Male SHRSP rats, were fed a defatted control diet containing 10% wt/wt soybean oil or a defatted treatment diet containing 10% wt/wt canola oil, and given tap water or water containing 1% NaCl. Blood was collected at the end of study for analysis of red blood cell (RBC) antioxidant enzymes, RBC and plasma malondialdehyde (MDA), plasma 8-isoprostane and plasma lipids. The aorta was removed and the mRNA expression of NOX2, p22phox, CuZn-SOD, Mn-SOD and EC-SOD were determined.Results: In the absence of salt, canola oil reduced RBC SOD and glutathione peroxidase, and increased total cholesterol and LDL cholesterol compared with soybean oil. RBC glutathione peroxidase activity was significantly lower in both the salt loaded groups compared to the soybean oil only group. In addition, RBC MDA and plasma HDL cholesterol were significantly higher in both the salt loaded groups compared to the no salt groups. Plasma MDA concentration was higher and LDL cholesterol concentration lower in the canola oil group loaded with salt compared to the canola oil group without salt. The mRNA expression of NADPH oxidase subunits and SOD isoforms were significantly reduced in the canola oil group with salt compared to canola oil group without salt.Conclusion: In conclusion, these results indicate that canola oil reduces antioxidant status and increases plasma lipids, which are risk factors for cardiovascular disease. However, canola oil in combination with salt intake increased MDA, a marker of lipid peroxidation and decreased NAPDH oxidase subunits and aortic SOD gene expression.<br /

Question Answering with distilled BERT models: A case study for Biomedical Data

In the healthcare industry today, 80% of data is unstructured (Razzak et al., 2019). The challenge this imposes on healthcare providers is that they rely on unstructured data to inform their decision-making. Although Electronic Health Records (EHRs) exist to integrate patient data, healthcare providers are still challenged with searching for information and answers contained within unstructured data. Prior NLP and Deep Learning research has shown that these methods can improve information extraction on unstructured medical documents. This research expands upon those studies by developing a Question Answering system using distilled BERT models. Healthcare providers can use this system on their local computers to search for and receive answers to specific questions about patients. This paper’s best TinyBERT and TinyBioBERT models had Mean Reciprocal Rank (MRRs) of 0.522 and 0.284 respectively. Based on these findings this paper concludes that TinyBERT performed better than TinyBioBERT on BioASQ task 9b data