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Alterations to gene transcription and DNA methylation are a feature of many liver diseases including fatty liver disease and liver cancer. However, it is unclear whether the DNA methylation changes are a cause or a consequence of the transcriptional changes. It is even possible that the methylation changes are not required for the transcriptional changes. If DNA methylation is just a minor player in, or a consequence of liver transcriptional change, then future studies in this area should focus on other systems such as histone tail modifications. To interrogate the importance of de novo DNA methylation, we generated mice that are homozygous mutants for both Dnmt3a and Dnmt3b in post-natal liver. These mice are viable and fertile with normal sized livers. Males, but not females, showed increased adipose depots, yet paradoxically, improved glucose tolerance on both control diet and high-fat diets (HFD). Comparison of the transcriptome and methylome with RNA sequencing and whole-genome bisulfite sequencing in adult hepatocytes revealed that widespread loss of methylation in CpG-rich regions in the mutant did not induce loss of homeostatic transcriptional regulation. Similarly, extensive transcriptional changes induced by HFD did not require de novo DNA methylation. The improved metabolic phenotype of the Dnmt3a/3b mutant mice may be mediated through the dysregulation of a subset of glucose and fat metabolism genes which increase both glucose uptake and lipid export by the liver. However, further work is needed to confirm this.
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DNA (Citosina-5-)-Metiltransferases , Metilação de DNA , DNA Metiltransferase 3A , DNA Metiltransferase 3B , Dieta Hiperlipídica , Intolerância à Glucose , Fígado , Animais , Masculino , Dieta Hiperlipídica/efeitos adversos , Fígado/metabolismo , Camundongos , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , DNA Metiltransferase 3A/metabolismo , Intolerância à Glucose/metabolismo , Intolerância à Glucose/genética , Feminino , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: We have shown previously in multivariable analysis that black men had 19% lower risk of death than white men with metastatic castration-resistant prostate cancer (mCRPC) treated with a docetaxel and prednisone (DP)-based regimen. The primary goal of this analysis was to compare progression-free survival (PFS), biochemical PFS, ≥50% decline in prostate-specific antigen (PSA) from baseline and objective response rate (ORR) in white, black and Asian men with mCRPC treated with a DP-based regimen. PATIENTS AND METHODS: Individual patient data from 8820 mCRPC men randomized on nine phase III trials to a DP-containing regimen were combined. Race used in the analysis was based on self-report. End points were PFS, biochemical PSA, ≥50% decline in PSA from baseline and ORR. The proportional hazards and the logistic regression models were employed to assess the prognostic importance of race in predicting outcomes adjusting for established prognostic factors. RESULTS: Of 8820 patients, 7528 (85%) were white, 500 (6%) were black, 424 were Asian (5%) and 368 (4%) had race unspecified. Median PFS were 8.3 [95% confidence interval (CI) 8.2-8.5], 8.2 (95% CI 7.4-8.8) and 8.3 (95% CI 7.6-8.8) months in white, black and Asian men, respectively. Median PSA PFS were 9.9 (95% CI 9.7-10.4), 8.5 (95% CI 8.0-10.3) and 11.1 (95% CI 9.9-12.5) months in white, black and Asian men, respectively. CONCLUSIONS: We observed no differences in clinical outcomes by race and ethnic groups in men with mCRPC enrolled on these phase III clinical trials with DP.
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Neoplasias de Próstata Resistentes à Castração , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Intervalo Livre de Doença , Docetaxel/uso terapêutico , Etnicidade , Humanos , Masculino , Prednisona/uso terapêutico , Antígeno Prostático Específico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Estudos Retrospectivos , Resultado do TratamentoRESUMO
The consolidation of long-term memory is influenced by various neuromodulators. One of these is estradiol, a steroid hormone that is synthesized both in peripheral endocrine tissue and in the brain, including the hippocampus. Here, we examine the evidence regarding the role of estradiol in the hippocampus, specifically, in memory formation and its effects on the molecular mechanisms underlying synaptic plasticity. We conclude that estradiol improves memory consolidation and, thereby, long-term memory. Previous studies have shown that it does this in three, interconnected ways: (1) via functional changes in excitatory activity, (2) signaling changes in calcium dynamics, protein phosphorylation and protein expression, and (3) structural changes to synaptic morphology. Through a functional network analysis of proteins affected by estradiol, we identify potential protein-protein interactions that further support a role for estradiol in modulating synaptic plasticity as well as highlight signaling pathways that may be involved in these changes within the hippocampus.
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Estradiol/fisiologia , Hipocampo/fisiologia , Memória/fisiologia , Plasticidade Neuronal/fisiologia , Adulto , Animais , Estradiol/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Feminino , Hipocampo/efeitos dos fármacos , Humanos , Masculino , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Fosforilação/fisiologia , Ratos , Receptores de Estrogênio/fisiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Potenciais Sinápticos/efeitos dos fármacos , Potenciais Sinápticos/fisiologiaRESUMO
AIMS: To examine incidence of complications associated with outpatient total hip arthroplasty (THA), and to see if medical comorbidities are associated with complications or extended length of stay. PATIENTS AND METHODS: From June 2013 to December 2016, 1279 patients underwent 1472 outpatient THAs at our free-standing ambulatory surgery centre. Records were reviewed to determine frequency of pre-operative medical comorbidities and post-operative need for overnight stay and complications which arose. RESULTS: In 87 procedures, the patient stayed overnight for 23-hour observation, with 39 for convenience reasons and 48 (3.3%) for medical observation, most frequently urinary retention (13), obstructive sleep apnoea (nine), emesis (four), hypoxia (four), and pain management (six). Five patients (0.3%) experienced major complications within 48 hours, including three transferred to an acute facility; there was one death. Overall complication rate requiring unplanned care was 2.2% (32/1472). One or more major comorbidities were present in 647 patients (44%), including previous coronary artery disease (CAD; 50), valvular disease (nine), arrhythmia (219), thromboembolism history (28), obstructive sleep apnoea (171), chronic obstructive pulmonary disease (COPD; 124), asthma (118), frequent urination or benign prostatic hypertrophy (BPH; 217), or mild chronic renal insufficiency (11). CONCLUSION: The presence of these comorbidities was not associated with medical or surgical complications. However, presence of one or more major comorbidity was associated with an increased risk of overnight observation. Specific comorbidities associated with increased risk were CAD, COPD, and frequent urination/BPH. Outpatient THA is safe for a large proportion of patients without the need for a standardised risk assessment score. Risk of complications is not associated with presence of medical comorbidities. Cite this article: Bone Joint J 2018;100-B(1 Supple A):31-5.
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Procedimentos Cirúrgicos Ambulatórios , Artroplastia de Quadril/métodos , Tempo de Internação , Complicações Pós-Operatórias/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Complicações Pós-Operatórias/epidemiologia , Fatores de RiscoRESUMO
BACKGROUND: Altered mitochondrial function and large-scale changes to DNA methylation patterns in the nuclear genome are both hallmarks of colorectal cancer (CRC). Mitochondria have multiple copies of a 16 kb circular genome that contains genes that are vital for their function. While DNA methylation is known to alter the nuclear genome in CRC, it is not clear whether it could have a similar influence in mtDNA; indeed, currently, the issue of whether mitochondrial genome (mtDNA) methylation occurs is controversial. Thus our goal here was to determine whether the methylation state of mtDNA is linked to mitochondrial gene transcription in colorectal adenomas, and to assess its suitability as a biomarker in CRC. METHODS: To investigate the relationship between DNA methylation and mitochondrial transcripts in adenomas, we performed RNA-sequencing and Whole Genome Bisulphite Sequencing (WGBS) of mtDNA-enriched DNA from normal mucosa and paired adenoma patient samples. RESULTS: Transcriptional profiling indicated that adenomas had reduced mitochondrial proton transport versus normal mucosa, consistent with altered mitochondrial function. The expression of 3 tRNAs that are transcribed from mtDNA were also decreased in adenoma. Overall methylation of CG dinucleotides in the nuclear genome was reduced in adenomas (68%) compared to normal mucosa (75%, P < 0.01). Methylation in mtDNA was low (1%) in both normal and adenoma tissue but we observed clusters of higher methylation at the ribosomal RNA genes. Levels of methylation within these regions did not differ between normal and adenoma tissue. CONCLUSIONS: We provide evidence that low-level methylation of specific sites does exist in the mitochondrial genome but that it is not associated with mitochondrial gene transcription changes in adenomas. Furthermore, as no large scale changes to mtDNA methylation were observed it is unlikely to be a suitable biomarker for early-stage CRC.
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STUDY QUESTION: Can maternal and offspring high-fat diet (HFD)-induced changes in mRNA expression levels in mice be ameliorated by interventions in female offspring? SUMMARY ANSWER: Our results indicate that exercise and nicotinamide mononucleotide (NMN) can ameliorate the negative effects of maternal and post-weaning HFD in female offspring. WHAT IS KNOWN ALREADY: Maternal and post-weaning HFD can perturb offspring developmental trajectories. As rates of maternal obesity are rising globally, there is a need for effective treatments in offspring to ameliorate the negative effects from a maternal obesogenic environment. Modulation of the nicotinamide adenine dinucleotide (NAD+) pathway by exercise and the NAD+ precursor NMN has previously been shown to reduce the effects of obesity. STUDY DESIGN SIZE DURATION: This study consisted of a multigenerational study using C57Bl6 mice. Mice were fed a control (chow) or HFD ad libitum throughout mating, pregnancy and lactation (n = 13-25). Female offspring (n = 72) were then also supplied either a chow or HFD post-weaning. At 9 weeks of age offspring from HFD dams were subjected to exercise on a treadmill for 9 weeks or at 16 weeks of age administered NMN (i.p.) for 2.5 weeks. At 18.5 weeks mice were euthanized and ovaries and cumulus-oocyte complexes (COC) were collected to examine the possibility of ameliorating the negative effects of maternal and post-weaning HFD. PARTICIPANTS/MATERIALS SETTING METHODS: Ovary and COC mRNA expression was analysed using RT-qPCR. An initial screen of candidate genes was developed to test which molecular pathways may be involved in generating adverse reproductive system effects. For histological analysis, ovarian tissue was fixed in paraformaldehyde and embedded in paraffin and stained with haematoxylin and eosin. The numbers of primordial, primary, secondary and antral follicles were counted. MAIN RESULTS AND THE ROLE OF CHANCE: In the offspring's COC, maternal obesity increased both growth differentiation factor 9 (Gdf9: 2-fold; P < 0.05, HFD versus chow) and bone morphogenetic protein 15 (Bmp15: 4-fold; P < 0.05, HFD versus chow) mRNA expression levels while exercise and NMN interventions did not regulate Gdf9 and Bmp15 in the same manner. In whole ovary, maternal diet programmed a 25-50% reduction in FSH receptor and sirtuin-3 mRNA expression levels in daughter ovaries (P < 0.05, HFD versus chow). There was a significant interaction between HFD and intervention on the proportion of large preantral and preovulatory follicles (P < 0.05). However, the increase in preovulatory follicles did not translate to increased oocyte yield. NMN administration resulted in reduced body weight in HFD-fed individuals. LIMITATIONS REASONS FOR CAUTION: It is unclear if the changes in oocyte mRNA expression levels reported here will impact oocyte quality and fertility in offspring. Offspring ovulation rate or fecundity could not be studied here and fertility trials are required to determine if the changes in gene expression do reduce fertility. WIDER IMPLICATIONS OF THE FINDINGS: Our results demonstrate that maternal and offspring HFD perturbs key signalling pathways that are known to regulate fertility in mice, highlighting the importance of interventions in helping to prevent the declining rates of fertility in the context of the current obesity epidemic. STUDY FUNDING/COMPETING INTERESTS: This work was supported by grants and fellowships from the National Health and Medical Research Council to R.B.G. (APP1023210, APP1062762, APP1117538) and to M.J.M. and D.A.S. (APP1044295). DAS is a consultant to and inventor on patents licenced to Ovascience, Metrobiotech and GlaxoSmithKline. The other authors declare that there is no conflict of interest.
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The western diet is known to have detrimental effects on cognition and the gut microbiota, but few studies have investigated how these may be related. Here, we examined whether a probiotic could prevent diet-induced memory deficits. Rats were pre-exposed to vehicle, low or high doses of VSL#3 for 2 weeks before half were switched from chow to a cafeteria diet (Caf) for 25 days; VSL#3 treatment continued until death. High-dose VSL#3 prevented the diet-induced memory deficits on the hippocampal-dependent place task, but the probiotic caused deficits on the perirhinal-dependent object task, irrespective of diet or dose. No differences were observed in anxiety-like behaviour on the elevated plus maze. Gut microbial diversity was dramatically decreased by Caf diet and here, VSL#3 was able to increase the abundance of some taxa contained in the probiotic such as Streptococcus and Lactobacillus and also other taxa including Butyrivibrio, which were decreased by the Caf diet. This affected the predicted profile of microbial metabolic pathways related to antioxidant and bile biosynthesis, and fat and carbohydrate metabolism. In the hippocampus, the Caf diet increased the expression of many genes related to neuroplasticity and serotonin receptor (5HT) 1A, which was normalised in Caf-High rats. Distance-based linear modelling showed that these genes were the best predictors of place memory, and related to microbiota principal component (PC) 1. Neuroplasticity genes in the perirhinal cortex were also affected and related to PC1 but object memory performance was correlated with perirhinal 5HT2C expression and microbiota PC3. These results show that probiotics can be beneficial in situations of gut dysbiosis where memory deficits are evident but may be detrimental in healthy subjects.
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Microbioma Gastrointestinal/efeitos dos fármacos , Memória/efeitos dos fármacos , Probióticos/farmacologia , Animais , Cognição/fisiologia , Dieta , Dieta Ocidental/efeitos adversos , Microbioma Gastrointestinal/fisiologia , Hipocampo , Masculino , Memória/fisiologia , Transtornos da Memória/microbiologia , Plasticidade Neuronal/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores de Serotonina/fisiologia , Serotonina/metabolismoRESUMO
Previous studies suggest lower concentrations of total and high-density lipoprotein (HDL) cholesterol to be predictive of depression. We therefore investigated the relationship of lipids and lipoprotein distribution with elevated depressive symptoms (EDS) in healthy men and women from the Multi-Ethnic Study of Atherosclerosis (MESA). Participants were followed up over a 9.5-year period. EDS were defined as a Center for Epidemiological Studies Depression (CES-D) score ⩾16 and/or use of antidepressant drugs. Lipoprotein distribution was determined from plasma using nuclear magnetic resonance spectroscopy. Among 4938 MESA participants (mean age=62 years) without EDS at baseline, 1178 (23.9%) developed EDS during follow-up. In multivariable Cox regression analyses, lower total, low-density lipoprotein (LDL) and non-HDL cholesterol concentrations at baseline were associated with incident EDS over 9.5 years (hazards ratio (HR)=1.11-1.12 per s.d. decrease, all P<0.01), after adjusting for demographic factors, traditional risk factors including LDL cholesterol, HDL cholesterol and triglycerides. Lipoprotein particle subclasses and sizes were not associated with incident EDS. Among participants without EDS at both baseline and visit 3, a smaller increase in total or non-HDL cholesterol between these visits was associated with lower risk of incident EDS after visit 3 (HR=0.88-0.90 per s.d. decrease, P<0.05). Lower baseline concentrations of total, LDL and non-HDL cholesterol were significantly associated with a higher risk of incident EDS. However, a short-term increase in cholesterol concentrations did not help to reduce the risk of EDS. Further studies are needed to replicate our findings in cohorts with younger participants.
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Aterosclerose/sangue , Aterosclerose/etnologia , Transtorno Depressivo/sangue , Transtorno Depressivo/etnologia , Lipídeos/sangue , Lipoproteínas/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos de Coortes , Feminino , Seguimentos , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Estatística como Assunto , Triglicerídeos/sangue , Estados UnidosRESUMO
Epidemiology formed the basis of 'the Barker hypothesis', the concept of 'developmental programming' and today's discipline of the Developmental Origins of Health and Disease (DOHaD). Animal experimentation provided proof of the underlying concepts, and continues to generate knowledge of underlying mechanisms. Interventions in humans, based on DOHaD principles, will be informed by experiments in animals. As knowledge in this discipline has accumulated, from studies of humans and other animals, the complexity of interactions between genome, environment and epigenetics, has been revealed. The vast nature of programming stimuli and breadth of effects is becoming known. As a result of our accumulating knowledge we now appreciate the impact of many variables that contribute to programmed outcomes. To guide further animal research in this field, the Australia and New Zealand DOHaD society (ANZ DOHaD) Animals Models of DOHaD Research Working Group convened at the 2nd Annual ANZ DOHaD Congress in Melbourne, Australia in April 2015. This review summarizes the contributions of animal research to the understanding of DOHaD, and makes recommendations for the design and conduct of animal experiments to maximize relevance, reproducibility and translation of knowledge into improving health and well-being.
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AIMS: Since redesign of the Oxford phase III mobile-bearing unicompartmental knee arthroplasty (UKA) femoral component to a twin-peg design, there has not been a direct comparison to total knee arthroplasty (TKA). Thus, we explored differences between the two cohorts. PATIENTS AND METHODS: A total of 168 patients (201 knees) underwent medial UKA with the Oxford Partial Knee Twin-Peg. These patients were compared with a randomly selected group of 177 patients (189 knees) with primary Vanguard TKA. Patient demographics, Knee Society (KS) scores and range of movement (ROM) were compared between the two cohorts. Additionally, revision, re-operation and manipulation under anaesthesia rates were analysed. RESULTS: The mean follow-up for UKA and TKA groups was 5.4 and 5.5 years, respectively. Six TKA (3.2%) versus three UKAs (1.5%) were revised which was not significant (p = 0.269). Manipulation was more frequent after TKA (16; 8.5%) versus none in the UKA group (p < 0.001). UKA patients had higher post-operative KS function scores versus TKA patients (78 versus 66, p < 0.001) with a trend toward greater improvement, but there was no difference in ROM and KS clinical improvement (p = 0.382 and 0.420, respectively). CONCLUSION: We found fewer manipulations, and higher functional outcomes for patients treated with medial mobile-bearing UKA compared with TKA. TKA had twice the revision rate as UKA although this did not reach statistical significance with the numbers available. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):28-33.
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Artroplastia do Joelho/instrumentação , Prótese do Joelho , Osteoartrite do Joelho/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Artroplastia do Joelho/métodos , Artroplastia do Joelho/reabilitação , Feminino , Humanos , Articulação do Joelho/fisiopatologia , Masculino , Pessoa de Meia-Idade , Medição da Dor/métodos , Desenho de Prótese , Falha de Prótese , Amplitude de Movimento Articular , Sistema de Registros , Reoperação/estatística & dados numéricos , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BACKGROUND: Magnetic resonance imaging (MRI) is not routinely performed before initiating radium-223 to document spinal epidural disease. However, radium-223 decays to form α-particles with very short path lengths that may not reach the epidural space. Herein, we investigate the impact of baseline spinal epidural disease on metastatic castration-resistant prostate cancer (mCRPC) patients treated with radium-223. METHODS: Between October 2013 to December 2014, 41 consecutive mCRPC patients at a large tertiary cancer center were prescribed radium-223 as part of standard of care. 29% of patients had pre-treatment epidural disease (posMRI), 27% had no epidural disease (negMRI), and 44% did not have a baseline MRI (noMRI). All patients had post-treatment spinal imaging. Actuarial survival times were calculated for overall survival (OS), spinal axis radiographic progression-free survival (spinePFS) and epidural progression-free survival (epiPFS) from time of first radium-223 treatment. RESULTS: For patients with posMRI (n=12), noMRI (n=18) and negMRI (n=11) cumulative rates of development or worsening of epidural disease and/or high-grade cord compression at time of last follow-up were 83%, 44% and 9%, respectively (P=0.001). For the posMRI, noMRI and negMRI groups the median OS was 6.3 months, 12.6 months and not reached (P=0.01), the median spinePFS was 3.2 months, 4.8 months and not reached (P=0.01), and the median epiPFS was 3.2 months, 10.4 months and not reached (P=0.001). Completing less than six cycles of radium-223 was significantly associated with worse OS (P<0.0001), spinePFS (P=0.007) and epiPFS (P=0.01). Greater than or equal to twenty osseous lesions pre-treatment was significantly associated with worse spinePFS (P=0.001) and epiPFS (P=0.03). CONCLUSIONS: In a heavily pre-treated small cohort, patients with baseline epidural disease frequently progressed to spinal cord compression and early cessation of radium-223 therapy. Studies are needed to determine the optimal timing of radium-223 with other mCRPC therapies given the predilection for epidural disease and treatment failure after multiple prior lines of mCRPC therapy.
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Braquiterapia , Neoplasias de Próstata Resistentes à Castração/mortalidade , Neoplasias de Próstata Resistentes à Castração/radioterapia , Rádio (Elemento)/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Progressão da Doença , Neoplasias Epidurais/diagnóstico , Neoplasias Epidurais/secundário , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Prognóstico , Neoplasias de Próstata Resistentes à Castração/diagnóstico , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Chronic high-energy diets are known to induce obesity and impair memory; these changes have been associated with inflammation in brain areas crucial for memory. In this study, we investigated whether inflammation could also be related to diet-induced memory deficits, prior to obesity. We exposed rats to chow, chow supplemented with a 10% sucrose solution (Sugar) or a diet high in fat and sugar (Caf+Sugar) and assessed hippocampal-dependent and perirhinal-dependent memory at 1 week. Both high-energy diet groups displayed similar, selective hippocampal-dependent memory deficits despite the Caf+Sugar rats consuming 4-5 times more energy, and weighing significantly more than the other groups. Extreme weight gain and excessive energy intake are therefore not necessary for deficits in memory. Weight gain across the diet period however, was correlated with the memory deficits, even in the Chow rats. The Sugar rats had elevated expression of a number of inflammatory genes in the hippocampus and WAT compared to Chow and Caf+Sugar rats but not in the perirhinal cortex or hypothalamus. Blood glucose concentrations were also elevated in the Sugar rats, and were correlated with the hippocampal inflammatory markers. Together, these results indicate that liquid sugar can rapidly elevate markers of central and peripheral inflammation, in association with hyperglycemia, and this may be related to the memory deficits in the Sugar rats.
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Dieta Hiperlipídica , Sacarose Alimentar/efeitos adversos , Hipocampo/efeitos dos fármacos , Inflamação/induzido quimicamente , Transtornos da Memória/induzido quimicamente , Animais , Peso Corporal/efeitos dos fármacos , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Citocinas/genética , Citocinas/metabolismo , Ingestão de Energia/fisiologia , Comportamento Alimentar , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/metabolismo , Inflamação/sangue , Insulina/sangue , Masculino , Transtornos da Memória/sangue , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Ratos , Ratos Sprague-Dawley , Reconhecimento Psicológico/efeitos dos fármacos , Reconhecimento Psicológico/fisiologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Triglicerídeos/sangueRESUMO
The prevalence of hedonic foods and associated advertising slogans has contributed to the rise of the obesity epidemic in the modern world. Research has shown that intake of these foods disrupt dopaminergic systems. It may be that a disruption of these circuits produces aberrant learning about food-cue relationships. We found that rodents given 28 days of intermittent access to sucrose exhibited a deficit in the ability to block learning about a stimulus when it is paired in compound with food and another stimulus that has already been established as predictive of the food outcome. This deficit was characterized by an approach to a cue signaling food delivery that is usually blocked by prior learning, an effect dependent on dopaminergic prediction-error signaling in the midbrain. Administering the D2 agonist quinpirole during learning restored blocking in animals with a prior history of sucrose exposure. Further, repeated central infusions of ghrelin produced a deficit in blocking in the same manner as sucrose exposure. We argue that changes in dopaminergic systems resulting from sucrose exposure are mediated by a disruption of ghrelin signaling as rodents come to anticipate delivery of the highly palatable sucrose outside of normal feeding schedules. This suggestion is supported by our finding that both sucrose and ghrelin treatments resulted in increases in amphetamine-induced locomotor responding. Thus, for the first time, we have provided evidence of a potential link between alterations in D2 receptors caused by the intake of hedonic foods and aberrant learning about cue-food relationships capable of promoting inappropriate feeding habits. In addition, we have found preliminary evidence to suggest that this is mediated by changes in ghrelin signaling, a finding that should stimulate further research into modulation of ghrelin activity to treat obesity.
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Aprendizagem por Associação/fisiologia , Sinais (Psicologia) , Alimentos , Grelina/fisiologia , Receptores de Dopamina D2/fisiologia , Sacarose/administração & dosagem , Anfetamina/administração & dosagem , Animais , Comportamento de Escolha , Agonistas de Dopamina/administração & dosagem , Grelina/administração & dosagem , Masculino , Atividade Motora/efeitos dos fármacos , Quimpirol/administração & dosagem , Ratos Sprague-Dawley , Receptores de Dopamina D2/agonistas , Transdução de Sinais , Edulcorantes/administração & dosagemRESUMO
Understanding the neurobiological substrates that encode learning about food-associated cues and how those signals are modulated is of great clinical importance especially in light of the worldwide obesity problem. Inappropriate or maladaptive responses to food-associated cues can promote over-consumption, leading to excessive energy intake and weight gain. Chronic exposure to foods rich in fat and sugar alters the reinforcing value of foods and weakens inhibitory neural control, triggering learned, but maladaptive, associations between environmental cues and food rewards. Thus, responses to food-associated cues can promote cravings and food-seeking by activating mesocorticolimbic dopamine neurocircuitry, and exert physiological effects including salivation. These responses may be analogous to the cravings experienced by abstaining drug addicts that can trigger relapse into drug self-administration. Preventing cue-triggered eating may therefore reduce the over-consumption seen in obesity and binge-eating disorder. In this review we discuss recent research examining how cues associated with palatable foods can promote reward-based feeding behaviours and the potential involvement of appetite-regulating peptides including leptin, ghrelin, orexin and melanin concentrating hormone. These peptide signals interface with mesolimbic dopaminergic regions including the ventral tegmental area to modulate reactivity to cues associated with palatable foods. Thus, a novel target for anti-obesity therapeutics is to reduce non-homeostatic, reward driven eating behaviour, which can be triggered by environmental cues associated with highly palatable, fat and sugar rich foods.
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Apetite/fisiologia , Comportamento Alimentar/fisiologia , Peptídeos/fisiologia , Recompensa , Animais , Sinais (Psicologia) , Alimentos , HumanosRESUMO
BACKGROUND AND AIMS: Growing evidence suggests maternal obesity leads to adverse outcomes for offspring, including increased cardiovascular disease (CVD). Alterations in taste preferences of offspring from mothers consuming a high fat diet (HFD) have also been reported. Given recent reports describing cardiac taste receptors, we examined whether the expression of umami and bitter taste receptors is modulated by maternal obesity, and compared this with the physiological challenge of maternal exercise. METHODS AND RESULTS: Female Sprague-Dawley rats were fed chow (C) or HFD (F) and half of each were provided with a running wheel to enable voluntary exercise (CE or FE), the others remaining sedentary (CS or FS). Two pups from each mother were killed at postnatal day 19. Both lean and obese dams undertook similar amounts of exercise (8.1 ± 2.4 vs 5.1 ± 1.5 km). Maternal obesity increased offspring body weight, adiposity, net and weight-corrected heart ventricle weight, with no effect of exercise. Maternal obesity also increased offspring plasma leptin concentrations, which were normalised by maternal exercise. Cardiac ventricle mRNA expression of bitter taste receptors, ß-adrenoceptor (Adrbk1) and angiotensin II receptor type 1a (Agtr1a) were significantly decreased in response to maternal obesity, with maternal exercise decreasing Agtr1a in FE offspring. No changes in umami receptors were observed. FTO mRNA expression was down-regulated by maternal HFD with an up-regulation in offspring of CE mothers. CONCLUSION: Maternal obesity affected the expression of bitter taste receptors and other genes in the heart ventricle, potentially implicating these genes in the development of CVD associated with maternal obesity.
Assuntos
Expressão Gênica , Ventrículos do Coração/metabolismo , Proteínas/genética , Adiposidade/fisiologia , Dioxigenase FTO Dependente de alfa-Cetoglutarato , Animais , Peso Corporal , Dieta , Dieta Hiperlipídica/efeitos adversos , Regulação para Baixo , Feminino , Leptina/sangue , Fenômenos Fisiológicos da Nutrição Materna , Obesidade , Condicionamento Físico Animal , Gravidez , Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Regulação para CimaRESUMO
Direct anterior approaches to the hip have gained popularity as a minimally invasive method when performing primary total hip replacement (THR). A retrospective review of a single institution joint registry was performed in order to compare patient outcomes after THR using the Anterior Supine Intermuscular (ASI) approach versus a more conventional direct lateral approach. An electronic database identified 1511 patients treated with 1690 primary THRs between January 2006 and December 2010. Our results represent a summary of findings from our previously published work. We found that patients that underwent an ASI approach had faster functional recovery and higher Harris hip scores in the early post-operative period when compared with patients who had a direct lateral approach The overall complication rate in our ASI group was relatively low (1.7%) compared with other series using the same approach. The most frequent complication was early periprosthetic femoral fractures (0.9%). The dislocation rate in our series was 0.4% and the prosthetic joint infection rate was 0.1%. We suggest that the ASI approach is acceptable and safe when performing THR and encourages early functional recovery of our patients.
Assuntos
Artroplastia de Quadril/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Osteoartrite do Quadril/cirurgia , Complicações Pós-Operatórias/epidemiologia , Adulto , Feminino , Seguimentos , Articulação do Quadril/fisiopatologia , Articulação do Quadril/cirurgia , Humanos , Incidência , Tempo de Internação/tendências , Masculino , Pessoa de Meia-Idade , Amplitude de Movimento Articular , Recuperação de Função Fisiológica , Estudos Retrospectivos , Resultado do Tratamento , Estados Unidos/epidemiologiaRESUMO
The present investigation aims to establish the reason(s) why dairy cows with high somatic cell counts (SCCs; >100,000 cells/ml) are less fertile than cows with low SCCs alone. The objective of Study One was to determine whether differences in steroid hormone profiles could explain the low incidence of ovulation in cows with combined High SCC and lameness. Between 30 and 80 days post-partum, animals were scored for SCC and lameness and three groups were formed: Healthy (n=22), High SCC alone (n=12) or High SCC + Lame (n=9). The ovarian follicular phases of all cows were synchronised by administering gonadotrophin releasing hormone (GnRH) followed seven days later by prostaglandin F2alpha (PG). Milk samples were collected daily throughout the entire study period; twice daily during the follicular phase, blood samples were taken and the ovaries were monitored using ultrasonography. Progesterone concentrations were similar in all three groups during each of five specific time periods, i.e. throughout the five days before PG injection, the peri-ovulatory period, on Day 5 and on Day 7, and during the mid luteal phase 12-17 days after ovulation (P>0.13). Mean plasma oestradiol concentrations monitored every 12h during the 36h period before ovulation were similar in all groups (Healthy, 2.80±0.30pg/ml; High SCC alone, 3.82±0.48pg/ml; High SCC+Lame 2.94±0.51pg/ml; P=0.175). The objective of Study Two was to establish whether cows with High SCC (scored and synchronised as above) display different behaviours, especially the intensity and timing of oestrus. Intervals from PG to the onset of oestrus or to the first stand-to-be-mounted (STBM) were longer for the High SCC cows than the Low SCC animals (n=8 and 20; P=0.011 and 0.002, respectively). Also, cows with High SCC tended to have a less intense oestrus and a lower maximum oestrus score per 30-min period than Low SCC cows (P=0.063 and 0.066, respectively). In conclusion, High SCC±lameness did not affect progesterone or twice daily oestradiol profiles but the onset of oestrus was delayed and oestrus tended to be less intense in cows with High SCC. These factors could explain low fertility associated with High SCC.
Assuntos
Doenças dos Bovinos/etiologia , Estro/fisiologia , Coxeadura Animal/complicações , Leite/citologia , Progesterona/sangue , Comportamento Sexual Animal/fisiologia , Animais , Bovinos , Doenças dos Bovinos/metabolismo , Indústria de Laticínios , Estradiol/sangue , FemininoRESUMO
Maternal overnutrition is implicated in the development of adult metabolic disease, and has been shown to alter the expression of genes involved in energy homeostasis. In the present study, we aimed to test whether a short period of voluntary exercise, followed by a sedentary period, would regulate hypothalamic markers involved in appetite. Adult female Sprague-Dawley rats were fed either normal chow or high-fat diet (HFD) ad lib. for 5 weeks, mated and continued on their assigned diet during gestation/lactation. At weaning males, were separated into chow or HFD groups; half were exercised (running wheels), whereas the remainder were sedentary. At week 10, wheels were removed and rats remained sedentary for 5 weeks, prior to tissue collection. Maternal obesity increased offspring adiposity at 15 weeks and this was exacerbated by postnatal HFD (P < 0.05). Body weight and fat mass were reduced in offspring of obese mothers if they exercised, and this was maintained even after 5 weeks without exercise. At 15 weeks, fasting plasma insulin, leptin and triglyceride concentrations were significantly reduced by exercise in offspring of lean and obese mothers consuming chow, with little benefit in those consuming HFD. Hypothalamic mRNA expression of pro-opiomelanocortin was increased by exercise but only in offspring of lean mothers. Exercise reduced hypothalamic FTO (fat mass and obesity associated) mRNA in offspring of lean dams regardless of diet. A short period of exercise early in life had lasting beneficial effects on body weight, adiposity and hormone profile of male offspring from obese and lean dams, despite being followed by a period of inactivity. The effects of exercise on hypothalamic appetite regulators were more marked in offspring of lean dams.
Assuntos
Regulação da Expressão Gênica , Hipotálamo/metabolismo , Exposição Materna , Obesidade/fisiopatologia , Condicionamento Físico Animal , Proteínas/genética , Adiposidade , Dioxigenase FTO Dependente de alfa-Cetoglutarato , Animais , Glicemia/metabolismo , Peso Corporal , Feminino , Obesidade/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
AIM: Physical exercise reduces obesity, insulin resistance and dyslipidemia. We previously found that maternal obesity alters central appetite circuits and contributes to increased adiposity, glucose intolerance and metabolic disease in offspring. Here we hypothesized that voluntary exercise would ameliorate the adverse metabolic effects of maternal obesity on offspring. METHODS AND RESULTS: Sprague-Dawley females fed chow (C) or high-fat diet HFD (H) were mated. Female offspring from C dams were weaned onto chow (CC); those from H dams recieved chow (HC) or HFD (HH). Half of each group was provided with running wheels (CC(EX), HC(EX), HH(EX); n=10-12). Maternal obesity increased body weight (12%), adiposity, plasma lipids and induced glucose intolerance (HC vs CC; P<0.05). These were exaggerated by postweaning HFD (HH vs HC; P<0.01), showed doubled energy intake, a 37% increase in body weight, insulin resistance and glucose intolerance (HH vs HC; P<0.01). Exercise reduced fat mass, plasma lipids, HOMA and fasting glucose in HC(EX) (vs HC; P<0.05) and HH(EX) (vs HH; P<0.01). Values in HC(EX) were indistinguishable from CC, however in HH(EX) these metabolic parameters remained higher than the sedentary HC and CC rats (P<0.01). mRNA expression of hypothalamic pro-opiomelanocortin, and adipose tumour necrosis factor α and 11ß-hydroxysteroid dehydrogenase type 1 were reduced by exercise in HH(EX) (vs HH; P<0.05). CONCLUSION: While voluntary exercise almost completely reversed the metabolic effects of maternal obesity in chow fed offspring, it did not fully attenuate the increased adiposity, glucose intolerance and insulin resistance in offspring weaned onto HFD.