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Background: Energy-dense diets have been implicated as a driving force in the global obesity crisis. Sucrose derived from sugar cane (Saccharum officinarum) is a carbohydrate source at the centre of this discussion. However, sugar cane is... more
Background: Energy-dense diets have been implicated as a driving force in the global obesity crisis. Sucrose derived from sugar cane (Saccharum officinarum) is a carbohydrate source at the centre of this discussion. However, sugar cane is a complex plant containing a wide variety of phytochemicals that may have anti-obesity properties. The objective of this study was to assess if polyphenols extracted from sugar cane were capable of mitigating the progression of diet-induced obesity. Methods: Forty-five male, six-week-old C57BL/6J mice were divided into groups of 15 and fed a high-fat, high-carbohydrate diet supplemented with 0%, 2% or 4% polyphenol-rich sugarcane extract (PRSE) for twelve weeks. Body weight, food intake, water intake and faecal content were measured in addition to dual energy x-ray absorptiometry (DEXA) of the mice. Gene expression was also assessed for a range of key metabolic pathways in both blood and tissue samples in order to determine PRSE’s potential mechani...
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Image segmentation is a key process in analyzing biological images. However, it is difficult to detect the differences between foreground and background when the image is unevenly illuminated. The unambiguous segmenting of multi-well... more
Image segmentation is a key process in analyzing biological images. However, it is difficult to detect the differences between foreground and background when the image is unevenly illuminated. The unambiguous segmenting of multi-well plate microscopy images with various uneven illuminations is a challenging problem. Currently, no publicly available method adequately solves these various problems in bright-field multi-well plate images. Here, we propose a new method based on contrast values which removes the need for illumination correction. The presented method is effective enough to distinguish foreground and therefore a model organism (Caenorhabditis elegans) from an unevenly illuminated microscope image. In addition, the method also can solve a variety of problems caused by different uneven illumination scenarios. By applying this methodology across a wide range of multi-well plate microscopy images, we show that our approach can consistently analyze images with uneven illuminati...
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Traditional toxicological studies have relied heavily on various animal models to understand the effect of various compounds in a biological context. Considering the great cost, complexity and time involved in experiments using higher... more
Traditional toxicological studies have relied heavily on various animal models to understand the effect of various compounds in a biological context. Considering the great cost, complexity and time involved in experiments using higher order organisms. Researchers have been exploring alternative models that avoid these disadvantages. One example of such a model is the nematode Caenorhabditis elegans. There are some advantages of C. elegans, such as small size, short life cycle, well defined genome, ease of maintenance and efficient reproduction. As these benefits allow large scale studies to be initiated with relative ease, the problem of how to efficiently capture, organize and analyze the resulting large volumes of data must be addressed. We have developed a new method for quantitative screening of chemicals using C. elegans. 33 features were identified for each chemical treatment. The compounds with different toxicities were shown to alter the phenotypes of C. elegans in distinct ...
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Responses to exogenous growth hormone were measured in lactating dairy cows surgically prepared to allow measurement of nutrient exchanges across mammary and hind-limb muscle tissues. Cows were injected daily with either saline or growth... more
Responses to exogenous growth hormone were measured in lactating dairy cows surgically prepared to allow measurement of nutrient exchanges across mammary and hind-limb muscle tissues. Cows were injected daily with either saline or growth hormone, at a dose of 0�1 mg/kg liveweight, over periods of 6 days.
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Exosomes are extracellular vesicles secreted by multiple cell types into the extracellular space. They contain cell-state specific cargos which often reflects the (patho)physiological condition of the cells/organism. Milk contains high... more
Exosomes are extracellular vesicles secreted by multiple cell types into the extracellular space. They contain cell-state specific cargos which often reflects the (patho)physiological condition of the cells/organism. Milk contains high amounts of exosomes and it is unclear whether their cargo is altered based on the lactation stage of the organism. Here, we isolated exosomes from bovine milk that were obtained at various stages of lactation and examined the content by quantitative proteomics. Exosomes were isolated by OptiPrep density gradient centrifugation from milk obtained from cow after 24, 48 and 72 h post calving. As control, exosomes were also isolated from cows during mid-lactation period which has been referred to as mature milk (MM). Biochemical and biophysical characterization of exosomes revealed the high abundance of exosomes in colostrum and MM samples. Quantitative proteomics analysis highlighted the change in the proteomic cargo of exosomes based on the lactation st...
Research Interests: Biology, Proteomics, Cell Biology, Lactation, Medicine, and 3 moreImmune system, Colostrum, and Microvesicles
Glycine catabolism was studied in isolated rat liver mitochondria by measuring the release of 14CO2 from [1-14C]glycine. Mitochondria isolated from rats fed on a high-protein (60% casein) diet for 5 days showed an enhanced ability to... more
Glycine catabolism was studied in isolated rat liver mitochondria by measuring the release of 14CO2 from [1-14C]glycine. Mitochondria isolated from rats fed on a high-protein (60% casein) diet for 5 days showed an enhanced ability to catabolize glycine compared with mitochondria from rats fed on a normal-protein (15% casein) diet. Glycine catabolism was also stimulated in normal protein-fed rats if they ingested a single high-protein meal for 2 h before being killed, thus illustrating the rapid response of the glycine-cleavage system to protein intake. The stimulation of glycine catabolism in rats given a high-protein diet or meal was not evident if the mitochondria were incubated in the absence of P(i) (omitting ADP had no effect on the rate). Mitochondria from high-protein- and normal-protein-fed rats did not differ in their ability to accumulate glycine, a process which occurred far too rapidly to impose a limit on the rate of flux through the glycine-cleavage system. The stimula...
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1. The catabolism of glycine was studied in isolated rat liver mitochondria by measuring release of 14CO2 from [1-14C]-glycine. Incubation of mitochondria in a medium containing 0.5 microM free Ca2+ resulted in an 8-fold increase in the... more
1. The catabolism of glycine was studied in isolated rat liver mitochondria by measuring release of 14CO2 from [1-14C]-glycine. Incubation of mitochondria in a medium containing 0.5 microM free Ca2+ resulted in an 8-fold increase in the rate of degradation of glycine. Intraperitoneal injection of glucagon (33 or 100 micrograms/100 g body wt.) 25 min before killing of rats also resulted in a 3-fold or 10-fold (depending on dosage) increase in the rate of catabolism of glycine. 2. Both the stimulation by free Ca2+ and that by injection of glucagon in vivo were dependent on phosphate in the incubation medium. This requirement for phosphate was specific, as replacement of phosphate by other permeant anions such as thiocyanate and acetate did not permit the stimulation. The phosphate-dependent stimulation of glycine catabolism by Ca2+ was also evident when mitochondria were incubated in the absence of K+. 3. Mitochondria isolated from rats previously injected with glucagon showed elevate...
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The glycine cleavage enzyme system (GCS) is found in mitochondria. In liver it is activated by glucagon and other hormones but it is not known how the hormonal signal is transmitted to the mitochondria. We found that the cell-permeant... more
The glycine cleavage enzyme system (GCS) is found in mitochondria. In liver it is activated by glucagon and other hormones but it is not known how the hormonal signal is transmitted to the mitochondria. We found that the cell-permeant protein phosphatase inhibitor okadaic acid stimulated flux through GCS and could induce a significant increase in the sensitivity of GCS and of glycogenolysis to glucagon. Half-maximal stimulation of GCS by glucagon occurred at 3.2±0.6 nM, whereas it was fully activated at 0.3 nM in the presence of 1 μM okadaic acid. The protein kinase A agonist adenosine-3ʹ,5ʹ-cyclic monophosphorothioate, Sp isomer (10 μM) stimulated the GCS flux by approx. 100%. This stimulation was inhibited by the protein kinase A antagonist 8-bromoadenosine-3ʹ,5ʹ-cyclic monophosphorothioate, Rp isomer (Rp-8-Br-cAMPS). Although Rp-8-Br-cAMPS significantly inhibited glucagon-stimulated glycogenolysis it had no effect on the glucagon-stimulated GCS flux. These results indicate that a...
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Exosomes are membranous vesicles that are released by a variety of cells into the extracellular microenvironment and are implicated in intercellular communication. As exosomes contain RNA, proteins and lipids, there is a significant... more
Exosomes are membranous vesicles that are released by a variety of cells into the extracellular microenvironment and are implicated in intercellular communication. As exosomes contain RNA, proteins and lipids, there is a significant interest in characterizing the molecular cargo of exosomes. Here, we describe ExoCarta (http://www.exocarta.org), a manually curated web-based compendium of exosomal proteins, RNAs and lipids. Since its inception, the database has been highly accessed (>54,000 visitors from 135 countries). The current version of ExoCarta hosts 41,860 proteins, >7,540 RNA and 1,116 lipid molecules from more than 286 exosomal studies annotated with ISEV minimal experimental requirements for definition of extracellular vesicles. Besides, ExoCarta features dynamic protein-protein interaction networks and biological pathways of exosomal proteins. Users can download most often identified exosomal proteins based on the number of studies. The downloaded files can further b...
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ScopeThis study shows the effect of bovine milk derived extracellular vesicles (BMEVs) on spontaneous polyarthritis in IL‐1Ra‐deficient mice and collagen‐induced arthritis.Methods and resultsBMEVs were isolated from semi‐skimmed milk by... more
ScopeThis study shows the effect of bovine milk derived extracellular vesicles (BMEVs) on spontaneous polyarthritis in IL‐1Ra‐deficient mice and collagen‐induced arthritis.Methods and resultsBMEVs were isolated from semi‐skimmed milk by ultracentrifugation and the particle size was around 100 nm by dynamic light scattering and electron microscopy. BMEVs expressed exosome marker CD63, immunoregulatory microRNA's (miR‐30a, ‐223, ‐92a), and milk‐specific beta‐casein and beta‐lactoglobulin mRNA. In vitro, PKH‐67‐labeled BMEVs were taken up by RAW264.7, splenocytes, and intestinal cells as determined by flow cytometry and confocal microscopy. IL‐1Ra−/− mice received BMEVs by daily oral gavage starting at wk 5 till 15 after birth and collagen‐induced arthritis mice via their drinking water starting 1 wk before immunization till day 40. Macroscopically, BMEV treatment delayed the onset of arthritis and histology showed diminished cartilage pathology and bone marrow inflammation in both...
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There are a myriad of proteins responsible for modulation of expenditure of energy. Angiotensin II (Ang II) is a vital component of renin-angiotensin system that affects blood pressure and also linked to both cachexia and obesity via fat... more
There are a myriad of proteins responsible for modulation of expenditure of energy. Angiotensin II (Ang II) is a vital component of renin-angiotensin system that affects blood pressure and also linked to both cachexia and obesity via fat and muscle metabolism. Previous research suggests that the direct action of Ang II is on the brain, via angiotensin II type 1 receptor protein, affecting food intake and energy expenditure. The objective of the study is to investigate the effect of 1-sarcosine (SAR)-Ang II infusion on energy expenditure and metabolism in a rat model of congestive heart failure cachexia. Adult female rats of the Sprague Dawley strain (n = 33) were used (11 pair-fed control, 12 ad libitum and 10, 1-sarcosine-angiotensin II-infused rats). Body weight, faecal excretion, feed intake (in grams), water intake (in milliliters) and urine excreted were recorded daily. The measurements were recorded in three different periods (4 days prior to surgery, "pre-infusion";...
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SELENIUM DEFICIENCY INCREASED THE HYPERTENSIVE EFFECT OF AN OMEGA-3 FATTY ACID DEFICIENT DIET Ahmad Hafandia,e, Shirmila D. Premaratnaa, Denovan P. Begga,c, Michael L. Mathaid, Andrew J. Sinclairc, Diana Joy Reymentb, Mark Joisb & Richard... more
SELENIUM DEFICIENCY INCREASED THE HYPERTENSIVE EFFECT OF AN OMEGA-3 FATTY ACID DEFICIENT DIET Ahmad Hafandia,e, Shirmila D. Premaratnaa, Denovan P. Begga,c, Michael L. Mathaid, Andrew J. Sinclairc, Diana Joy Reymentb, Mark Joisb & Richard S. Weisingera a School of Psychological Science, La Trobe University, Victoria 3086, Australia; b Department of Agriculture, La Trobe University, Victoria 3086, Australia; c School of Exercise and Nutrition Sciences, Deakin University, Victoria 3125, Australia; d Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Victoria 3010, Australia; e Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia. Increased oxidative stress has been suggested to contribute to hypertension. Although omega-3 (ω-3) fatty acid deficiency has been shown to increase oxidative stress, development of hypertension has been inconsistent. The aim of the...
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The uptake and metabolism of propionate in the isolated perfused caudal lobe of the liver and in isolated hepatocytes were examined following treatment of sheep with glucagon or saline. Glucagon or sterile saline was infused at 9·8 µg/min... more
The uptake and metabolism of propionate in the isolated perfused caudal lobe of the liver and in isolated hepatocytes were examined following treatment of sheep with glucagon or saline. Glucagon or sterile saline was infused at 9·8 µg/min for 3 h into the jugular vein and then the caudal lobe of the liver was removed surgically under anaesthesia. The caudal lobe was used either to prepare hepatocytes or in a non-recirculating perfusion experiment. Uptake and metabolism of propionate were studied using [2-14C]propionate. In studies using the non-recirculation perfusion of the caudal lobe of the sheep liver it was shown that the treatment of sheep with glucagon resulted in an increased rate of gluconeogenesis from propionate and in an increased net uptake of propionate by the caudal lobe. The uptake of propionate into the hepatocytes was saturable, concentrative and exhibited a Kmfor propionate of 0·24 (SE 0·07) mM and a maximal rate of uptake (Vmax) of 6·7 (SE 0·6) nmol/mg dry cells ...
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In addition to its role in the storage of fat, adipose tissue acts as an endocrine organ, and it contains a functional renin-angiotensin system (RAS). Angiotensin-converting enzyme (ACE) plays a key role in the RAS by converting... more
In addition to its role in the storage of fat, adipose tissue acts as an endocrine organ, and it contains a functional renin-angiotensin system (RAS). Angiotensin-converting enzyme (ACE) plays a key role in the RAS by converting angiotensin I to the bioactive peptide angiotensin II (Ang II). In the present study, the effect of targeting the RAS in body energy homeostasis and glucose tolerance was determined in homozygous mice in which the gene for ACE had been deleted (ACE −/− ) and compared with wild-type littermates. Compared with wild-type littermates, ACE −/− mice had lower body weight and a lower proportion of body fat, especially in the abdomen. ACE −/− mice had greater fed-state total energy expenditure (TEE) and resting energy expenditure (REE) than wild-type littermates. There were pronounced increases in gene expression of enzymes related to lipolysis and fatty acid oxidation (lipoprotein lipase, carnitine palmitoyl transferase, long-chain acetyl CoA dehydrogenase) in the ...
Research Interests: Endocrinology, Chemistry, Biology, Energy Metabolism, Biological Sciences, and 15 moreAdipose tissue, Animals, Body Composition, Energy Expenditure, Enzyme, Fat Mass, Fatty Acid, Body Weight, Drinking, Abdominal Fat, Body Fat, Calorimetry, Angiotensin Converting Enzyme, Angiotensin II, and Fatty acid metabolism
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BACKGROUND Acute coronary syndrome (ACS) activates neurohormonal pathways, including elevations in circulating aldosterone, with deleterious cardiovascular effects. We aimed to determine if early, more complete... more
BACKGROUND Acute coronary syndrome (ACS) activates neurohormonal pathways, including elevations in circulating aldosterone, with deleterious cardiovascular effects. We aimed to determine if early, more complete renin-angiotensin-aldosterone system inhibition (RAASI) in post-ACS patients without ventricular dysfunction or heart failure would result in a graded reduction in aldosterone concentrations. METHODS We performed serial measurement of serum aldosterone within the Aliskiren and Valsartan to Reduce NT-proBNP via Renin-Angiotensin-Aldosterone-System Blockade (AVANT GARDE)–Thrombolysis in Myocardial Infarction (TIMI) 43 trial, a randomized double-blind, placebo controlled trial of RAASI by valsartan, aliskiren, or both in post-ACS patients with preserved ventricular function but increased natriuretic peptides. Aldosterone was measured at randomization and week 8. RESULTS Median aldosterone concentrations were comparable across treatment arms at baseline (9.26 ng/dL; interquartile...
Research Interests: Cardiology, Medicine, Clinical Chemistry, Humans, Internal Medicine, and 15 morePlacebo, Medical Biotechnology, Aldosterone, Female, Male, Clinical Sciences, Middle Aged, Acute Coronary Syndrome, Amides, Myocardial Infarction, Retrospective Studies, Angiotensin Converting Enzyme Inhibitors, Tetrazoles, Valine, and Medical biochemistry and metabolomics
Captopril, given for 5 days to normotensive healthy subjects caused a significant fall in blood pressure. The fall in mean supine blood pressure was greater on a low sodium diet (10 mmols/day) - 19.6% and was less on a high sodium diet... more
Captopril, given for 5 days to normotensive healthy subjects caused a significant fall in blood pressure. The fall in mean supine blood pressure was greater on a low sodium diet (10 mmols/day) - 19.6% and was less on a high sodium diet (350 mmols/day) - 11% compared to the normal sodium intake (120 mmols/day) when the fall in blood pressure was 16.5%. Patients with essential hypertension who were studied on their normal diet had a similar fall in blood pressure for a given plasma renin activity. It seems likely that the predominant mechanism whereby captopril lowers blood pressure is through the inhibition of the formation of angiotensin II. If this is so, our results suggest that the renin system is an important control of both normal and high blood pressure when on a normal sodium intake.
Research Interests: Endocrinology, Medicine, Humans, Internal Medicine, Hypertension, and 15 moreBlood Pressure, Aldosterone, Renin Angiotensin Aldosterone System, Clinical, Male, Clinical Sciences, Adult, Sodium, Time Factors, Angiotensin Converting Enzyme, Angiotensin II, Angiotensin Converting Enzyme Inhibitors, Captopril, supine position, and Renin
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The purpose of the study was to investigate the rôle of novel mitochondrial uncoupling proteins UCP2 and UCP3 in the poor efficiency of energy utilization observed in piglets offered a low protein diet. Eight male piglets (Landrace ×... more
The purpose of the study was to investigate the rôle of novel mitochondrial uncoupling proteins UCP2 and UCP3 in the poor efficiency of energy utilization observed in piglets offered a low protein diet. Eight male piglets (Landrace × Large White) from different litters were allocated randomly to one of two groups; a high protein group (HP) was given restricted amounts of a diet containing 270 g/kg of crude protein whereas the low protein group (LP) was offered ad libitum a diet containing 27 g/kg of crude protein. The experimental period extended over 4 weeks, including an initial period of 1 week for adaptation. Live weights were recorded weekly and food residues were weighed daily. During the 2nd and 3rd weeks, faeces were collected for measurement of digestible energy intake. Over the last 2 weeks whole body oxygen consumption was measured by indirect calorimetry before, 1·5 h after and 3·5 h after the start of feeding. The piglets were killed at the end of week 4 and tissue expr...
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Context Lamb loss and dyctocia are two major challenges in extensive farming systems. While visual observation can be impractical due to the large sizes of paddocks, number of animals and high labour cost, wearable sensors can be used to... more
Context Lamb loss and dyctocia are two major challenges in extensive farming systems. While visual observation can be impractical due to the large sizes of paddocks, number of animals and high labour cost, wearable sensors can be used to monitor the behaviour of ewes as there might be changes in their activities prior to lambing. This provides sufficient time for the farm manager to nurse those ewes that are at risk of dyctocia. Aim The objective of this study was to determine whether the behaviour of a pregnant ewe could predict the time of parturition. Methods Two separate trials were conducted: the first trial (T1), with 32 ewes, included human/video observations, and the second trial (T2), with 165 ewes, conducted with no humans present, to emulate real extensive farming settings. The ewes were fitted with tri-axial accelerometer sensors by means of halters. Three-dimensional movement data were collected for a period of at least 7 and 14 days in T1 and T2 respectively. The senso...
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BACKGROUND: Cocoa, a significant contributor of polyphenols to the western diet has been shown to be effective against Aβ induced toxicity in vitro. However, the effects of long-term cocoa supplementation on Aβ induced behavioural... more
BACKGROUND: Cocoa, a significant contributor of polyphenols to the western diet has been shown to be effective against Aβ induced toxicity in vitro. However, the effects of long-term cocoa supplementation on Aβ induced behavioural deficits, particularly on the short-term memory loss observed in human AD are not well defined. OBJECTIVE: This study characterized the phenotype of a pan-neuronal Aβ expressing C. elegans strain and investigated the effects of long-term cocoa supplementation on Aβ induced behavioural deficits including short-term memory loss and lifespan. METHODS: Cocoa powder was supplemented to the E. coli OP50 diet of C. elegans starting from L1 stage until they die. Neuronally controlled processes including locomotion, learning and memory were studied at different stages of the lifespan. In addition, lifespan was evaluated with different cocoa doses. Aβ fibril levels were determined with Thioflavin T. RESULTS: Aβ expressing worms showed a reduced growth, a reduced max...
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BACKGROUND: Cocoa, one of the richest dietary sources of polyphenols has been studied for its health promoting effects, but how long-term consumption of cocoa affects age-associated health and lifespan is not well defined. OBJECTIVE: The... more
BACKGROUND: Cocoa, one of the richest dietary sources of polyphenols has been studied for its health promoting effects, but how long-term consumption of cocoa affects age-associated health and lifespan is not well defined. OBJECTIVE: The objective of this study was to determine the effects of long-term cocoa consumption on age-associated health and lifespan in C. elegans METHODS: The standard E. coli OP50 diet of wild type C. elegans was supplemented with cocoa powder starting from L1 stage until they die. Body length and area were measured as indicators of worm nutrition. Age associated health was determined at different stages of life as day 4, day 8 and day 12 using worm locomotion, thermotolerance, cognition and mitochondrial function. In addition, lifespan was evaluated. RESULTS: Cocoa improved age-associated decline in neuromuscular function. Both mean and median lifespan were extended by cocoa supplementation. However, maximum lifespan was not affected. Cocoa showed beneficia...
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Research Interests: Endocrinology, Chemistry, Carbon Dioxide, Kinetics, Biological Chemistry, and 15 moreBiological Sciences, Internal Medicine, Glucagon, cyclic AMP, Animals, Enzyme, CHEMICAL SCIENCES, Dose Response Relationship, Gluconeogenesis, Chemical Reaction, Glycine, Cysteamine, Decarboxylation, Intracellular, and Bucladesine
Research Interests: Psychology and Medicine
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Myostatin is a negative regulator of skeletal muscle growth. Muscle tissue is the largest tissue in the body and influences body growth. Commercial Avian broiler chickens are selected for high growth rate and muscularity. Daweishan mini... more
Myostatin is a negative regulator of skeletal muscle growth. Muscle tissue is the largest tissue in the body and influences body growth. Commercial Avian broiler chickens are selected for high growth rate and muscularity. Daweishan mini chickens are a slow growing small-sized chicken breed. We investigated the relations between muscle (breast and leg) myostatin mRNA expression and body and muscle growth. Twenty chickens per breed were slaughtered at 0, 30, 60, 90, 120, and 150 days of age. Body and muscle weights were higher at all times in Avian chickens. Breast muscle myostatin expression was higher in Avian chickens than in Daweishan mini chickens at day 30. Myostatin expression peaked at day 60 in Daweishan mini chickens and expression remained higher in breast muscle. Daweishan mini chickens myostatin expression correlated positively with carcass weight, breast and leg muscle weight from day 0 to 60, and correlated negatively with body weight from day 90 to 150, while myostatin...
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Feed nitrogen (N) intakes in Australian grazing systems average 545 g cow day, indicating that urinary N is likely to be the dominant form excreted. Grazing animals spend disproportionate amounts of time in places on dairy farms where N... more
Feed nitrogen (N) intakes in Australian grazing systems average 545 g cow day, indicating that urinary N is likely to be the dominant form excreted. Grazing animals spend disproportionate amounts of time in places on dairy farms where N accumulation is likely to occur. We attached to grazing cows sensors that measure urine volume and N concentration, as well as global positioning systems sensors used to monitor the times the cows spent in different places on a farm and the location of urination events. The cows were monitored for up to 72 h in each of two seasons. More urination events and greater urine volumes per event were recorded in spring 2014 (3.1 L) compared with winter 2015 (1.4 L), most likely influenced by environmental conditions and the greater spring rainfall observed. Mean (range) N concentration (0.71%; 0.02 to 1.52%) and N load (12.8 g cow event; 0.3 to 64.5 g cow event) did not differ over the two monitoring periods. However, mean (range) daily N load was greater i...
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Caenorhabditis elegans are typically cultured in a monoxenic medium consisting of live bacteria. However, this introduces a secondary organism to experiments and restricts the manipulation of the nutritional environment. Due to the... more
Caenorhabditis elegans are typically cultured in a monoxenic medium consisting of live bacteria. However, this introduces a secondary organism to experiments and restricts the manipulation of the nutritional environment. Due to the intricate link between genes and environment, greater control and understanding of nutritional factors are required to push the C. elegans field into new areas. For decades, attempts to develop a chemically defined, axenic medium as an alternative for culturing C. elegans have been made. However, the mechanism by which the filter feeder C. elegans obtain nutrients from these liquid media is not known. Using a fluorescence-activated cell sorting based approach, we demonstrate growth in all past axenic C. elegans media to be dependent on the presence of previously unknown particles. This particle requirement of C. elegans led to development of liposome-based, nanoparticle culturing that allows full control of nutrients delivered to C. elegans.
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Background: We previously showed that cocoa, a rich source of polyphenols improved the age-associated health and extended the lifespan in C. elegans when supplemented starting from L1 stage. Aim: In this study, we aimed to find out the... more
Background: We previously showed that cocoa, a rich source of polyphenols improved the age-associated health and extended the lifespan in C. elegans when supplemented starting from L1 stage. Aim: In this study, we aimed to find out the effects of timing of cocoa exposure on longevity improving effects and the mechanisms and pathways involved in lifespan extension in C. elegans. Methods: The standard E. coli OP50 diet of wild type C. elegans was supplemented with cocoa powder starting from different larval stages (L1, L2, L3, and L4) till the death, from L1 to adult day 1 and from adult day 1 till the death. For mechanistic studies, different mutant strains of C. elegans were supplemented with cocoa starting from L1 stage till the death. Survival curves were plotted, and mean lifespan was reported. Results: Cocoa exposure starting from L1 stage till the death and till adult day 1 significantly extended the lifespan of worms. However, cocoa supplementation at other larval stages as we...