Mechanical unloading has deleterious effects on the musculoskeletal system and results in significant reductions in bone density, mass, and strength, which do not fully recover even years after returning to weightbearing. For example, the rate of bone loss in microgravity is 10-fold more rapid than the rate of loss seen in elderly Caucasian females, the population group most predisposed to osteoporosis. This raises concern with individuals who are exposed to multiple bed rest periods or crewmembers who make repeated missions. Exercise offers a way to reduce or reverse these effects. Dual-energy X-ray absorptiometry (DXA) densitometry and bone mineral density (BMD) alone are generally insufficient for capturing the complex changes in bone mass, structure, and integrity and not an accurate predictor of fracture risk. Therefore, it is essential to measure the mechanical properties of bone tissue directly using animal models. The hindlimb unloaded (HU) rat model is a well-established ground-based analog for studying bone response to disuse and effects of spaceflight. The current study is one of the very few that has measured longitudinally densitometric and mechanical properties of bone after repeated simulated microgravity and long-term recovery at multiple anatomic sites in skeletally mature rats. The specific aims were to characterize 1) loss and recovery dynamics of bone following a period of unloading, 2) bone response after a second exposure to 28 days of HU, following an initial 28 days of HU and a recovery period equal to twice the duration of initial exposure, and 3) effects of resistance exercise during recovery period following an initial HU exposure and its effects on a subsequent exposure. In general, our data showed that bone response to unloading and recovery is site-specific. More specifically, we found that: 1) the rat proximal tibia metaphysis modeled the loss and discordant recovery dynamics as seen in the International Space Station (ISS) crewmembers proximal femur better than the rat femoral neck; 2) the initial exposure to HU has minimal effect on the subsequent HU exposure, and detrimental effects of the second HU exposure were milder than the initial due to reduced mechanosensitivity of the bone; 3) exercise significantly enhanced recovery following the initial HU exposure, and losses during the second exposure were not affected by exercise in most cases.

A complex system exists to monitor the body’s energy status and regulate food intake and energy expenditure to maintain a constant body weight. However, this homeostatic system is not the sole system regulating appetite. The hedonic system comprised of the mesolimbic reward pathway influences motivation to eat and acts alongside the homeostatic system to control feeding behaviours. It is often assumed that the hedonic system promotes the consumption of palatable, energy-dense foods and this can disrupt homeostatic mechanisms regulating food intake, resulting in energy overconsumption and weight gain in the long term. Yet, it is unclear to what extent the homeostatic system can defend body weight in an environment rich in palatable, energy-dense foods. I hypothesised that the homeostatic system compensates for the energy in palatable foods by reducing subsequent energy consumption, defined as homeostatic caloric compensation. I investigated homeostatic caloric compensation in a rat model of restricted palatable, high-sugar food access. Rats were schedule-fed moderate amounts of sweetened condensed milk (SCM) daily in addition to ad lib bland diet access. Both male and female rats calorically compensated for the energy consumed from moderate amounts of SCM through a robust and accurate reduction in energy consumed from bland diet, resulting in no short-term changes in body weight gain. However, homeostatic responses were limited as male rats were unable to fully calorically compensate for the scheduled-feeding of large amounts of SCM, an apparent loss of homeostatic control. It was not investigated whether female rats are also unable to fully calorically compensate for large amounts of SCM. It is possible that male rats consume these large amounts of SCM due to hedonic drive but continue to eat bland diet to acquire nutrients that are not present in SCM. To determine whether male rats defend bland diet consumption due to nutrient requirements, rats were schedule-fed large amounts of SCM enriched with protein or fibre. However, male rats did not fully calorically compensate for the energy in large amounts of SCM when enriched with protein or fibre. Overall, these findings demonstrate that the homeostatic system is able to respond to the hedonic consumption of palatable food through caloric compensatory mechanisms to defend body weight. However, it appears that the homeostatic system is unable to effectively respond to excessive hedonic palatable food consumption through caloric compensation alone. To shed light on what homeostatic mechanisms may underlie this compensatory behaviour, I used expression of the immediate early gene c-Fos to investigate neuronal activity following the scheduled-feeding of moderate amounts of SCM in male rats. c-Fos expression was increased in the ventral tegmental area of the mesolimbic reward pathway and in the lateral hypothalamus. The lateral hypothalamus has been proposed to act as an interface between homeostatic and hedonic systems. Therefore, in response to the hedonic consumption of palatable food, the homeostatic system and reward pathway may interact. Additionally, c-Fos expression was increased in satiety mediating brain regions of the homeostatic system, including the nucleus of the solitary tract and dorsomedial hypothalamus. This suggests that the homeostatic system may compensate for the energy in the palatable food by reducing subsequent food intake through inducing satiety. Furthermore, following the consumption of SCM, c-Fos expression was increased in magnocellular oxytocin neurons of the hypothalamic supraoptic and paraventricular nucleus. I demonstrated that the oxytocin system was activated by gut-brain signalling potentially involving the nucleus of the solitary tract. Therefore, the oxytocin system may be involved in homeostatic compensatory mechanisms triggered in response to the hedonic consumption of SCM, as part of a pathway mediating satiety. Moreover, I showed that c-Fos expression was also increased in the hypothalamic supramammillary nucleus (SuM) following the consumption of SCM. It has been previously shown that the SuM is involved in reward-related motivated behaviours and was recently implicated in the motivation to acquire and consume palatable food rewards. I also demonstrated that c-Fos expression in the SuM might be specific to the motivated consumption of palatable food, consistent with the SuM being involved in reward-related motivated behaviours. Furthermore, there is additional evidence from these studies that the SuM may functionally communicate with brain regions in the homeostatic and hedonic systems, including the lateral hypothalamus, dorsomedial hypothalamus and ventral tegmental area. Finally, I explored whether the gut-secreted orexigenic hormone ghrelin activates the SuM, as ghrelin may act at the SuM to influence feeding motivation. However, systemic ghrelin administration did not influence SuM c-Fos expression. As the SuM is activated following the consumption of SCM and may act as an interface between the homeostatic and hedonic systems, it is possible that the SuM could be a key component in the regulation of hedonic feeding. Using a rat model, I have shown that homeostatic compensatory mechanisms are triggered in response to the hedonic consumption of palatable, high-sugar food to regulate energy intake. This response is likely to involve homeostatic satiety mechanisms and interactions between multiple brain regions involved in the homeostatic and hedonic control of food intake. Overall, these findings shed light on how the homeostatic system responds to hedonic energy consumption and highlights specific brain regions that may be involved in hedonic feeding or homeostatic compensatory responses.

A osteoporose, uma doença óssea progressiva, é considerada um grave problema de saúde pública, sendo uma das condições mais importantes associadas ao envelhecimento e que afeta milhões de pessoas no mundo. Esta doença multifatorial é caracterizada pela densidade óssea reduzida e deterioração da microarquitetura óssea. O objetivo deste trabalho foi investigar as mudanças comportamentais em células mesenquimais da medula óssea e células osteoblásticas da calvária de ratas induzidas à osteoporose. Após aprovação da Comissão de Ética no Uso de Animais, 18 ratas Wistar foram utilizadas e divididas em grupos controle e ovariectomizadas. Após 150 dias, as ratas de ambos os grupos foram sacrificadas para coleta dos fêmures e fragmentos da calvária. As células recolhidas a partir da medula óssea e calvária foram cultivadas em placas de 24 poços (n = 5) para avaliação da proliferação e viabilidade celular, atividade de fosfatase alcalina (ALP), detecção e quantificação de nódulos mineralizados e análise da expressão gênica por meio de PCR em tempo real. Os dados foram submetidos ao testes de Kruskal-Wallis e Mann-Whitney, com nível de significância de 5%. As células da medula óssea do grupo controle (MC) mostraram uma diminuição significativa na proliferação quando comparado com as células do grupo controle da calvária (CC) em todos os períodos (p < 0,05). Por outro lado, as células da medula óssea de ratas com osteoporose (MO) revelaram um aumento significativo na taxa de proliferação após 7 e 10 dias (p < 0,01) em comparação às células da calvária de ratas ovariectomizadas (CO). A viabilidade celular foi maior em todos os períodos estudados dos grupos CC e CO em relação aos grupos MC e MO (p < 0,05). A atividade de fosfatase alcalina não foi significativamente diferente após 7 dias de cultura entre os grupos estudados; por outro lado, após 10 e 14 dias, observou-se uma diminuição da sua atividade no grupo MC quando comparado ao grupo CC (p < 0,01). Nas ratas com osteoporose, as células da medula óssea mostraram um aumento desta atividade quando comparada às células de calvária (p < 0,01). A análise dos nódulos mineralizados após 14 e 21 dias revelou que os grupos controle CC e MC não apresentaram diferenças significativas, ao passo que no grupo MO observou-se um aumento da mineralização quando comparado ao grupo CO nos mesmos períodos experimentais. Os resultados obtidos na análise de expressão gênica mostraram que para os genes Runx2, Oc, Alpl, Rank-l e Er&alpha; a expressão no grupo MO foi maior que no grupo MC (p < 0,05), enquanto que para as células da calvária, CC teve maior expressão gênica que CO (p < 0,05). Os genes Opg e Er&beta; apresentaram variações de acordo com o grupo avaliado. Frente aos resultados obtidos, sugere-se que existam alterações no metabolismo das células progenitoras e células diferenciadas após a indução da osteoporose e que as células da medula óssea apresentam um aumento da sua função como uma resposta compensatória neste modelo animal ovariectomizado. / Osteoporosis, a progressive bone disease, is considered a serious public health problem, being one of the most important conditions associated with aging, affecting millions of people worldwide. This multifactorial disease is characterized by reduced bone density and deterioration of bone microarchitecture. The objective of this work was to investigate the behavioral changes in mesenchymal cells from bone marrow and osteoblastic cells from calvaria bone of female rats induced to osteoporosis. After institutional review board approval, 18 Wistar female rats were used and divided into control and ovariectomized groups. After 150 days, the rats of both groups were sacrificed for collection of femurs and calvariae fragments. The cells collected from bone marrow and calvaria were cultured in 24-well plates (n=5) for the assessment of cell proliferation and viability, alkaline phosphatase (ALP) activity and detection and quantification of mineralized nodules. The data were submitted to Kruskal-Wallis and Mann-Whitney tests, with significance level set at 5%. The cells from bone marrow control group (MC) showed a significantly decrease in proliferation when compared to the cells from calvaria bone control group (CC) in all periods evaluated (p < 0,05). On the other hand, bone marrow cells from osteoporotic rats (MO) revealed a significant increase in their proliferation rate after 7 and 10 days (p < 0,01) compared to calvaria cells from ovariectomized rats (CO). Cell viability was higher in all investigated periods of CC and CO groups compared to MC and MO groups (p < 0,05). Alkaline phosphatase activity was not significantly different after 7 days of culture among the studied groups; in spite of that, after 10 and 14 days, there was a decrease in its activity in MC group when compared to CC (p < 0,01). In the osteoporotic rats, bone marrow cells showed an increase in this activity when compared to calvaria cells (p < 0,01). The analysis of mineralized nodules after 14 and 21 days revealed that control groups (CC and MC) did not have significant differences, whereas it was observed in MO group an increase in the mineralization when compared to CO in the same experimental periods. The data obtained in the analysis of gene expression showed that for Runx2, Oc, Alpl, Rank-l and Er&alpha; genes, the expression in MO group was higher than in MC (p < 0,05), whereas for the calvaria cells, CC group had higher gene expression than CO group (p < 0,05). The Opg and Er&beta; genes showed variations according to the evaluated group. Thus, it is suggested that there are changes in the metabolism of progenitor and differentiated cells after osteoporosis induction and that bone marrow cells present an enhancement of their function as a compensatory response in this ovariectomized rat model.

Ethyl glucuronide (EtG) is a minor ethanol metabolite that confirms the absorption and metabolism of ethanol after oral or dermal exposure. Human data suggest that maximum blood EtG (BEtG) concentrations are reached between 3.5 and 5.5. h after ethanol administration. This study was undertaken to determine if the Sprague-Dawley (SD) rat biotransforms ethanol to EtG after a single high oral dose of ethanol. SD rats (male, n=6) were gavaged with a single ethanol dose (4g/kg), and urine was collected for 3. h in metabolic cages, followed by euthanization and collection of heart blood. Blood and urine were analyzed for ethanol and EtG by gas chromatography and enzyme immunoassay. Blood and urine ethanol concentrations were 195 ± 23 and 218 ± 19. mg/dL, whereas BEtG and urine EtG (UEtG) concentrations were 1,363 ± 98. ng equivalents/mL and 210 ± 0.29. mg equivalents/dL (X̄±standarderrorofthemean[S.E.M.]).Sixty-six male SD rats were gavaged ethanol (4. g/kg) and placed in metabolic cages to determine the extent and duration of ethanol to EtG biotransformation and urinary excretion. Blood and urine were collected up to 24. h after administration for ethanol and EtG analysis. Maximum blood ethanol, urine ethanol, and UEtG were reached within 4. h, whereas maximum BEtG was reached 6. h after administration. Maximum concentrations were blood ethanol, 213 ± 20. mg/dL; urine ethanol, 308 ± 34. mg/dL; BEtG, 2,683 ± 145. ng equivalents/mL; UEtG, 1.2 ± 0.06. mg equivalents/mL (X̄±S.E.M.). Areas under the concentration-time curve were blood ethanol, 1,578. h*mg/dL; urine ethanol, 3,096. h*mg/dL; BEtG, 18,284. h*ng equivalents/mL; and UEtG, 850. h*mg equivalents/dL. Blood ethanol and BEtG levels were reduced to below limits of detection (LODs) within 12 and 18. h after ethanol administration. Urine ethanols were below LOD at 18. h, but UEtG was still detectable at 24. h after administration. Our data prove that the SD rat biotransforms ethanol to EtG and excretes both in the urine and suggest that it is similar to that of the human.

Indiana University-Purdue University Indianapolis (IUPUI) / In present study, single quantum (SQ) and triple quantum filtered (TQF) 23Na magnetic resonance imaging (MRI) was used to monitor the severity and progression of CCl4 induced acute and chronic liver damage in rat model. SQ 23Na MRI was proposed to measure the 23Na signal intensity (SI) of total tissue sodium ions, and TQF 23Na MRI was proposed to measure the SI of intracellular sodium ions. In addition, shift reagent aided 23Na and 31P magnetic resonance spectroscopy (MRS) was used to measure in vivo intracellular sodium concentration ([Na+i]), total tissue sodium concentration ([Na+t]) and relative extracellular space (rECS) of liver in the same model. In acute high dose CCl4 intoxication, 24 hours after single dose of CCl4 in 5ml per kg body weight of mixture of CCl4 and oil in 1:1 ratio, SQ 23Na SI increased by 83% and TQF 23Na SI increased by 174% compared to the baseline level. According to SR-aided 23Na and 31P MRS, [Na+i] increased by 188% and [Na+t] increased by 43%. In addition, there was significant decrease in cellular energetic level, represented by ATP/Pi ratio. Histology examination showed pronounced inflammatory response in centrilobular regions, with neutrophiles infiltration, fatty accumulation and swollen hepatocytes. In chronic 8-week experiment, chronic damage was induced by biweekly administration of CCl4 in a dosage of 0.5 ml per kg body weight. From week 1 to week 6, SQ 23Na SI remained relatively constant, and then increased by 15% from week 6 to week 8. TQF 23Na SI progressively increased from week 1 to week 8, totally by 56%. Both SQ and TQF 23Na SI showed significant difference between treated group and control at every week. SR-aided 23Na and 31P MRS experiment showed that, at the end of 8-week CCl4 intoxication, both [Na+t] and rECS were higher than control, by 49% and 47% respectively; however, there was no significant difference for [Na+i] between two groups. Histology examination showed excessive deposition of extracellular matrix. In conclusion, SQ and TQF 23Na MRI appears valuable in the functional assessment of liver in noninvasive approach, and could be a promising diagnostic modality for liver diseases in clinical area.

Fibrinogen concentrates are used widely as a sealant during and after surgery to reduce blood loss. Commercially available fibrin sealants are made from pooled human blood, which carries the risk of blood-borne diseases, and are expensive. These concerns have brought to focus the need for autologous fibrinogen concentrates. This need has been addressed by utilizing a unique approach in which fibrinogen is precipitated from plasma with protamine. The physical properties of fibrin sealant prepared from fibrinogen precipitated with protamine were evaluated. The optimal precipitation conditions included a plasma protamine concentration of 10 mg/mL at room temperature. Under these conditions 96% ± 4% of the fibrinogen present in the plasma was precipitated and 98% ± 0.9% of the precipitated fibrinogen was clottable. In addition, it was shown that almost 50% of the factor XIII in the plasma was also precipitated along with the fibrinogen. The tensile and adhesion strengths and kinetics of fibrin sealant prepared from protamine-fibrinogen concentrate were evaluated. Tensile strength and adhesion strength both increased with increasing fibrinogen concentration. Addition of calcium chloride significantly increased the tensile and adhesion strengths. The addition of aprotinin and ε-aminocaproic acid (used to inhibit natural fibrinolysis) to the fibrinogen concentrate was shown to have no effect on the mechanical properties of the sealant. Kinetic experiments showed that the clotting time decreased as the thrombin and fibrinogen concentrations were increased. A rat model with controlled renal incisions was employed to evaluate the hemostatic efficacy of the fibrin sealant made from the protamine-fibrinogen concentrate. The fibrin sealant significantly reduced the blood loss and bleeding time when compared with controls (no sealant, plasma, and a commercial product). The sealant also significantly reduced blood loss and bleeding time in rats that were anticoagulated with heparin. A mathematical model based on tensile strength and adhesion strength was developed to predict the bleeding time in the animal wound. Model predictions showed that the ability of the fibrin sealant to reduce bleeding time, and therefore blood loss, was limited by the adhesion strength.

Chemotherapy is one of the most successful cancer treatments used today. Unfortunately, the amount of chemotherapy a patient can receive is limited by the associated negative side effects, such as cardiotoxicity, immune system suppression, and nephrotoxicity. Encapsulation of these drugs, Doxorubicin (DOX) in particular, in stabilized Pluronic micelles (Plurogel TM) shows success in limiting these harmful side effects. In previous studies, low-frequency ultrasound (US) has been shown, in vitro, to locally release DOX from these micelles. In this study, a novel drug delivery system involving the encapsulation of DOX in Plurogel and the release of the drug at the tumor site using ultrasound was studied in vivo using rats. These studies determined the effect of ultrasonically released drugs on tumor growth rate and drug delivery to the tumor tissue. Concurrently, different frequencies (20 kHz, 500 kHz) were tested for the same effects. Treatments consisted of micelle-encapsulated doxorubicin injected intravenously followed by ultrasound application to one of the two bilateral tumors. Also, in different experiments, pharmacokinetic studies of the drug in the heart, liver, leg muscle, and tumors were performed up to a period of one week after treatment. Results showed that tumors treated with ultrasound displayed, on average, slower growth rates than non-insonated tumors (P = 0.0047). Also, insonated tumors displayed a weak increased concentration of DOX than non-insonated tumors within the first eight hours after treatment (P = 0.064). However, comparison between tumors which received 20 kHz and 500 kHz ultrasound treatment showed no statistical difference (P = 0.9275) in tumor growth rate or DOX concentration. It is noteworthy that the insonated tumor has slower growth even though the amount of DOX was not that much greater in the non-insonated tumor. This suggests that US also affects the uptake and/or processing of the DOX by the tumor cells, and that the therapeutic effect may not be attributed solely to a higher concentration of drug released by insonation. Pharmacokinetic studies showed significant drug accumulation in the heart but no accumulation in the liver, skeletal leg muscle, or tumors over the course of four weeks of consecutive weekly injections of DOX-encapsulated Plurogel. After 24 hours, DOX concentration remains the greatest in the tumors, regardless of whether they received ultrasound or not.

No description available.

Yes / In this study the effects of photoperiod and diet, and their interaction, were examined for their effects on growth and body composition in juvenile F344 rats over a 4-week period. On long (16L:8D), relative to short (8L:16D), photoperiod food intake and growth rate were increased, but percentage adiposity remained constant (ca 3-4%). On a high fat diet (HFD), containing 22.8% fat (45% energy as fat), food intake was reduced, but energy intake increased on both photoperiods. This led to a small increase in adiposity (up to 10%) without overt change in body weight. These changes were also reflected in plasma leptin and lipid levels. Importantly while both lean and adipose tissue were strongly regulated by photoperiod on a chow diet, this regulation was lost for adipose, but not lean tissue, on HFD. This implies that a primary effect of photoperiod is the regulation of growth and lean mass accretion. Consistent with this both hypothalamic GHRH gene expression and serum IGF-1 levels were photoperiod dependent. As for other animals and humans, there was evidence of central hyposomatotropism in response to obesity, as GHRH gene expression was suppressed by the HFD. Gene expression of hypothalamic AgRP and CRH, but not NPY nor POMC, accorded with the energy balance status on long and short photoperiod. However, there was a general dissociation between plasma leptin levels and expression of these hypothalamic energy balance genes. Similarly there was no interaction between the HFD and photoperiod at the level of the genes involved in thyroid hormone metabolism (Dio2, Dio3, TSHβ or NMU), which are important mediators of the photoperiodic response. These data suggest that photoperiod and HFD influence body weight and body composition through independent mechanisms but in each case the role of the hypothalamic energy balance genes is not predictable based on their known function. / Scottish Government (Rural and Environment Science and Analytical Services Division, http://www.scotland.gov.uk/), AWR LR LMT PJM and the BBSRC, (http://www.bbsrc.ac.uk/home/home.aspx, grant BB/K001043/1), AWR GH PJM

No / Recent studies have gained positive results using nanoparticles (NPs) in treating atherosclerosis on animals. But their toxicity and application in treating other heart diseases such as heart failure and endocarditis still need proper investigation. Gold nanoparticles (Au-NPs) were chosen as model substances as they have been successfully used in treating cancer. In this study, we use both H9C2 myoblasts and rat peripheral blood mononuclear cells to determine the influence of Au-NP size on their cytotoxicity and cell apoptosis. H9C2 cells were treated with Au-NPs of a diameter of 5, 20, 40 and 100nmfor 24 hrs before their cell viabilities tested by MTT assay, cell apoptosis measured by flow cytometry, and the generation of reactive oxygen species (ROS) detected by Fluorometric Intracellular ROS Kit. Distribution of the Au-NPs and their effects on the structure of mitochondria and lysosome were detected by electron microscopy. In addition, we obtained rat peripheral blood mononuclear cells and treated them with Au-NPs same with H9C2 cell line. Our results showed NPs of 5, 40, and 100 nm reduced cell viabilities on H9C2 cells while20nm showed no change on cell viability (Ctrl: 100±8.2 vs 20nm: 95.39±9.13, P>0.05, n=6) and some protect effect on ISO induced H9C2 cells apoptosis (ISO: 100±13.5 vs 20nm: 80.19±17.36, P>0.05, n=6). All size of Au-NPs reduced cell viabilities on rat peripheral blood mononuclear cells while 40nm showed the least reduction on cell viability (Ctrl: 100.0±3.0 vs 40nm: 76.31±3.68, P<0.001, n=6) and significant protect effect on ISO-induced rat peripheral monocytes apoptosis (ISO: 100±1.86 vs 40nm: 45.34±10.32, P<0.05, n=6). In addition, 20nm Au-NP showed some protect effect on ROS generation on ISO-induced H9C2 cells (ISO: 100±3.79 vs 20nm: 94.84±4.98, P>0.05, n=6), while 40nm produced more ROS (ISO: 100±3.79 vs 40nm: 141.63±42.81, P>0.05, n=6). Electron microscopy detection showed correlated results in structure. These results on H9C2 cell line are basically in agreeable to our animal study. The protective effect of 20nm may due to its ability to protect ISO-induced ROS generation. The results on rat peripheral monocytes are slightly different to those on H9C2 cells. Further investigation need to focus on the role of NPs size on cell apoptosis by detecting autophagy specific protein through western blotting. / Abstract of conference paper.