36 results on '"James, Anthony"'
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2. Correction: Double vision: 2D and 3D mosquito trajectories can be as valuable for behaviour analysis via machine learning
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Qureshi, Yasser Mehmood, Voloshin, Vitaly, Towers, Catherine Elizabeth, Covington, James Anthony, and Towers, David Peter
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- 2024
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3. Double vision: 2D and 3D mosquito trajectories can be as valuable for behaviour analysis via machine learning
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Qureshi, Yasser Mehmood, Voloshin, Vitaly, Towers, Catherine Elizabeth, Covington, James Anthony, and Towers, David Peter
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- 2024
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4. Considerations for first field trials of low-threshold gene drive for malaria vector control
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Connolly, John B., Burt, Austin, Christophides, George, Diabate, Abdoulaye, Habtewold, Tibebu, Hancock, Penelope A., James, Anthony A., Kayondo, Jonathan K., Lwetoijera, Dickson Wilson, Manjurano, Alphaxard, McKemey, Andrew R., Santos, Michael R., Windbichler, Nikolai, and Randazzo, Filippo
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- 2024
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5. The dynamics of deltamethrin resistance evolution in Aedes albopictus has an impact on fitness and dengue virus type-2 vectorial capacity
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Guo, Yijia, Hu, Ke, Zhou, Jingni, Xie, Zhensheng, Zhao, Yijie, Zhao, Siyu, Gu, Jinbao, Zhou, Xiaohong, Yan, Guiyun, James, Anthony A., and Chen, Xiao-Guang
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- 2023
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6. Author Correction: Hidden genomic features of an invasive malaria vector, Anopheles stephensi, revealed by a chromosome-level genome assembly
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Chakraborty, Mahul, Ramaiah, Arunachalam, Adolfi, Adriana, Halas, Paige, Kaduskar, Bhagyashree, Ngo, Luna Thanh, Jayaprasad, Suvratha, Paul, Kiran, Whadgar, Saurabh, Srinivasan, Subhashini, Subramani, Suresh, Bier, Ethan, James, Anthony A., and Emerson, J. J.
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- 2022
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7. Hidden genomic features of an invasive malaria vector, Anopheles stephensi, revealed by a chromosome-level genome assembly
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Chakraborty, Mahul, Ramaiah, Arunachalam, Adolfi, Adriana, Halas, Paige, Kaduskar, Bhagyashree, Ngo, Luna Thanh, Jayaprasad, Suvratha, Paul, Kiran, Whadgar, Saurabh, Srinivasan, Subhashini, Subramani, Suresh, Bier, Ethan, James, Anthony A., and Emerson, J. J.
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- 2021
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8. A randomised controlled crossover trial investigating the short-term effects of different types of vegetables on vascular and metabolic function in middle-aged and older adults with mildly elevated blood pressure: the VEgetableS for vaScular hEaLth (VESSEL) study protocol
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Connolly, Emma L., Bondonno, Catherine P., Sim, Marc, Radavelli-Bagatini, Simone, Croft, Kevin D., Boyce, Mary C., James, Anthony P., Clark, Karin, Anokye, Reindolf, Bondonno, Nicola P., Woodman, Richard J., Devine, Amanda, Gan, Seng Khee, Schultz, Carl J., Mithen, Richard F., Lewis, Joshua R., Hodgson, Jonathan M., and Blekkenhorst, Lauren C.
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- 2020
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9. Physical activity and nutrition intervention for Singaporean women aged 50 years and above: study protocol for a randomised controlled trial
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Wong, Elaine Yee-Sing, Lee, Andy H., James, Anthony P., and Jancey, Jonine
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- 2018
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10. Three-dimensional cell culture can be regulated by vibration: low-frequency vibration increases the size of olfactory ensheathing cell spheroids
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Jenny Ekberg, Marie-Laure Vial, Johana Tello Velasquez, Mo Chen, Lachlan J. Beckingham, Michael Todorovic, and James Anthony St John
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0301 basic medicine ,Environmental Engineering ,Cell ,Biomedical Engineering ,Liquid marble ,02 engineering and technology ,Amplitude ,03 medical and health sciences ,3D cell culture ,In vivo ,Glia ,medicine ,lcsh:QH301-705.5 ,Molecular Biology ,Migration ,Transplantation ,Chemistry ,Regeneration (biology) ,Research ,Spheroid ,Cell Biology ,Ensheathing cell ,021001 nanoscience & nanotechnology ,030104 developmental biology ,medicine.anatomical_structure ,lcsh:Biology (General) ,Cell culture ,embryonic structures ,Biophysics ,0210 nano-technology - Abstract
Background Olfactory ensheathing cell (OEC) transplantation is emerging as a promising therapy for spinal cord injuries. However, outcomes are inconsistent, and the method needs improvement. Currently, cells are injected into the injury site as a suspension, and often fail to form a three-dimensional (3D) network crucial for both survival of the transplanted cells, and for regeneration of severed axons. 3D culture systems are therefore likely to improve the method. Of the many 3D culture systems available, the spheroid-producing naked liquid marble (NLM) technique is particularly advantageous compared to other platforms as it rapidly generates cell spheroids which can easily be extracted for further handling. To improve production of the spheroids, we designed and tested a device which allows fine control over vibrational stimuli to liquid marble cell cultures. We applied vibrational frequencies of 20, 60, and 80 Hz with consistent amplitude to NLM containing OECs and assessed the size and number of the 3D cell spheroids generated as well as the migratory capacity of cells cultured in the vibrated spheroids. Results Vibrating the NLMs led to fewer and dramatically larger spheroids in comparison to non-vibrated NLMs. Of the frequencies tested, 60 Hz caused over 70-fold increase in spheroid volume. When transferred to a culture plate, the larger spheroids retained their structure after 72 h in culture, and cells that migrated out of the spheroids covered a significantly larger area compared to cells migrating out of spheroids formed at all the other frequencies tested. Conclusions We have shown that vibration can be used to regulate the formation of cell spheroids in NLM cultures. The ability to modulate the size of spheroids is useful for a range of 3D cell culture models and for preparing cells for in vivo transplantation.
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- 2019
11. Physical activity and nutrition behaviour outcomes of a cluster-randomized controlled trial for adults with metabolic syndrome in Vietnam.
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Tran, Van Dinh, Lee, Andy H., Jancey, Jonine, James, Anthony P., Howat, Peter, Le Thi Phuong Mai, and Mai, Le Thi Phuong
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METABOLIC syndrome ,DIET in disease ,PHYSICAL activity ,NUTRITIONAL value ,NUTRITION - Abstract
Background: Metabolic syndrome is prevalent among Vietnamese adults, especially those aged 50-65 years. This study evaluated the effectiveness of a 6 month community-based lifestyle intervention to increase physical activity levels and improve dietary behaviours for adults with metabolic syndrome in Vietnam.Methods: Ten communes, involving participants aged 50-65 years with metabolic syndrome, were recruited from Hanam province in northern Vietnam. The communes were randomly allocated to either the intervention (five communes, n = 214) or the control group (five communes, n = 203). Intervention group participants received a health promotion package, consisting of an information booklet, education sessions, a walking group, and a resistance band. Control group participants received one session of standard advice during the 6 month period. Data were collected at baseline and after the intervention to evaluate programme effectiveness. The International Physical Activity Questionnaire - Short Form and a modified STEPS questionnaire were used to assess physical activity and dietary behaviours, respectively, in both groups. Pedometers were worn by the intervention participants only for 7 consecutive days at baseline and post-intervention testing. To accommodate the repeated measures and the clustering of individuals within communes, multilevel mixed regression models with random effects were fitted to determine the impacts of intervention on changes in outcome variables over time and between groups.Results: With a retention rate of 80.8%, the final sample comprised 175 intervention and 162 control participants. After controlling for demographic and other confounding factors, the intervention participants showed significant increases in moderate intensity activity (P = 0.018), walking (P < 0.001) and total physical activity (P = 0.001), as well as a decrease in mean sitting time (P < 0.001), relative to their control counterparts. Significant improvements in dietary behaviours were also observed, particularly reductions in intake of animal internal organs (P = 0.001) and in using cooking oil for daily meal preparation (P = 0.001).Conclusions: The prescribed community-based physical activity and nutrition intervention programme successfully improved physical activity and dietary behaviours for adults with metabolic syndrome in Vietnam.Trial Registration: Australian New Zealand Clinical Trials Registry, ACTRN12614000811606 . Registered on 31 July 2014. [ABSTRACT FROM AUTHOR]- Published
- 2017
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12. The chronic effects of fish oil with exercise on postprandial lipaemia and chylomicron homeostasis in insulin resistant viscerally obese men
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Slivkoff-Clark, Karin, James, Anthony, Mamo, John, Slivkoff-Clark, Karin, James, Anthony, and Mamo, John
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Background: Visceral obesity and insulin resistance are associated with a postprandial accumulation of atherogenic chylomicron remnants that is difficult to modulate with lipid-lowering therapies. Dietary fish oil and exercise are cardioprotective interventions that can significantly modify the metabolism of TAG-rich lipoproteins. In this study, we investigated whether chronic exercise and fish oil act in combination to affect chylomicron metabolism in obese men with moderate insulin resistance. Methods: The single blind study tested the effect of fish oil, exercise and the combined treatments on fasting and postprandial chylomicron metabolism. Twenty nine men with metabolic syndrome were randomly assigned to take fish oil or placebo for four weeks, before undertaking an additional 12 week walking program. At baseline and at the end of each treatment, subjects were tested for concentrations of fasting apo B48, plasma lipids and insulin. Postprandial apo B48 and TAG kinetics were also determined following ingestion of a fat enriched meal. Results: Combining fish oil and exercise resulted in a significant reduction in the fasting apo B48 concentration, concomitant with attenuation of fasting TAG concentrations and the postprandial TAGIAUC response (p < 0.05). Fish oil by itself reduced the postprandial TAG response (p < 0.05) but not postprandial apo B48 kinetics. Individual treatments of fish oil and exercise did not correspond with improvements in fasting plasma TAG and apo B48. Conclusion: Fish oil was shown to independently improve plasma TAG homeostasis but did not resolve hyper-chylomicronaemia. Instead, combining fish oil with chronic exercise reduced the plasma concentration of pro-atherogenic chylomicron remnants; in addition it reduced the fasting and postprandial TAG response in viscerally obese insulin resistant subjects.
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- 2012
13. Plasma triglyceride and high density lipoprotein cholesterol are poor surrogate markers of pro-atherogenic chylomicron remnant homeostasis in subjects with the metabolic syndrome.
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Irawati, Deasy, Mamo, John C. L., Dhaliwal, Satvinder S., Soares, Mario J., Slivkoff-Clark, Karin M., and James, Anthony P.
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METABOLIC syndrome ,TRIGLYCERIDES ,LIPOPROTEINS ,CHYLOMICRONS ,HOMEOSTASIS - Abstract
Background: Subjects with metabolic syndrome (MetS) exhibit impaired lipoprotein metabolism and have an increased risk of cardiovascular disease. Although the risk is attributed primarily to the risk associated with individual components, it is also likely affected by other associated metabolic defects. Remnants of postprandial lipoproteins show potent atherogenicity in cell and animal models of insulin resistance and in pre-diabetic subjects with postprandial dyslipidemia. However, few studies have considered regulation of chylomicron remnant homeostasis in MetS per se. This study measured the plasma concentration in Caucasian men and women of small dense chylomicrons following fasting and explored associations with metabolic and anthropometric measures. Methods: A total of 215 Australian Caucasian participants (median age 62 years) were investigated. Of them, 40 participants were classified as having MetS. Apolipoprotein (apo) B-48, an exclusive marker of chylomicrons, metabolic markers and anthropometric measures were determined following an overnight fast. Results: The fasting apo B-48 concentration was 40 % higher in subjects with MetS than those without MetS. In all subjects, triglyceride (r = 0.445, P < 0.0005), non-HDL cholesterol (r = 0.28, P < 0.0005) and HDL cholesterol concentration (r = -0.272, P < 0.0005) were weakly associated with apo B-48 concentration. In subjects with MetS, the association of apo B-48 with triglyceride and non-HDL cholesterol was enhanced, but neither were robust markers of elevated apo B-48 in MetS (r = 0.618 and r = 0.595 respectively). There was no association between apo B-48 and HDL cholesterol in subjects with MetS. Conclusion: This study demonstrates a substantial accumulation of pro-atherogenic remnants in subjects with MetS. We have shown that in a Caucasian cohort, the fasting plasma concentration of triglyceride or HDL/non-HDL cholesterol serves as poor surrogate markers of atherogenic chylomicron remnants. These findings suggest that subjects with MetS exhibit a chronic defect in chylomicron metabolism that is likely to contribute to their increased CV risk. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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14. Functional analysis of Orco and odorant receptors in odor recognition in Aedes albopictus.
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Hongmei Liu, Tong Liu, Lihua Xie, Xiaoming Wang, Yuhua Deng, Chun-Hong Chen, James, Anthony A., and Xiao-Guang Chen
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FUNCTIONAL analysis ,OLFACTORY receptors ,AEDES albopictus ,TISSUE-specific antigens ,RNA interference - Abstract
Background: Aedes albopictus is a globally invasive mosquito and a major vector of arboviruses, including dengue, Zika and Chikungunya. Olfactory-related behaviors, particularly host-seeking, offer opportunities to disrupt the disease-transmission process. A better understanding of odorant receptors (ORs) may assist in explaining host selection and location, and contribute to novel strategy of vector control. Methods: Based on previous prediction of 158 putative odorant receptors by Ae. albopictus genome analysis, 29 AalORs were selected for tissue-specific expression profiles in the present study. AalOrco (AalOR7), AalOR10 and AalOR88, highly expressed in female olfactory tissues, were chosen for further structure predictions as well as functional validation including calcium imaging assay in human embryonic kidney (HEK293) cells and RNA interference assay in Ae. albopictus. We also conducted electrophysiological and behavioral assays in mosquitoes after RNA interference of the three genes to determine their roles in host-seeking. Results: The results support previous conclusions that individual conventional (ORXs) and Orco can form heteromeric complexes to recognize odorants and respond to components of human volatiles in HEK293 cells. The reduction of AalOrco transcript levels led to a significant decrease in host-seeking and confusion in host preference. In contrast, AalOR10 and AalOR88 knockdown mosquitoes showed no significant behavioral differences compared with controls. The functions of conventional ORs at least AalOR10 and AalOR88 are abolished with inhibited expression of the Orco gene orthologs, along with the concomitant relevant olfactory behavior. Conclusions: Combining structural and functional data, we conclude that the product of the Orco gene in this mosquito is crucial for transmitting olfactory signaling and conventional ORs contribute directly to odorant recognition. Our results provide insight into the linkage between odorant receptors and host-seeking in this important vector species. [ABSTRACT FROM AUTHOR]
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- 2016
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15. Endogenously-expressed NH2-terminus of circumsporozoite protein interferes with sporozoite invasion of mosquito salivary glands.
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Kojin, Bianca B., Costa-da-Silva, André Luis, Maciel, Ceres, Henriques, Dayane Alves, Carvalho, Danilo O., Martin, Kelcie, Marinotti, Osvaldo, James, Anthony A., Bonaldo, Myrna C., and Capurro, Margareth Lara
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CIRCUMSPOROZOITE protein ,SPOROZOITES ,MALARIA ,POLYPEPTIDES ,SALIVARY glands ,PLASMODIUM gallinaceum - Abstract
Background: The circumsporozoite protein is the most abundant polypeptide expressed by sporozoites, the malaria parasite stage capable of infecting humans. Sporozoite invasion of mosquito salivary glands prior to transmission is likely mediated by a receptor/ligand-like interaction of the parasites with the target tissues, and the amino (NH
2 )-terminal portion of CSP is involved in this interaction but not the TSR region on the carboxyl (C)-terminus. Peptides based on the NH2 -terminal domain could compete with the parasites for the salivary gland receptors and thus inhibit penetration. Methods: Peptides based on the NH2 -terminus and TSR domains of the CSP from avian or human malaria parasites, Plasmodium gallinaceum and Plasmodium falciparum, respectively, were expressed endogenously in mosquito haemolymph using a transient (Sindbis virus-mediated) or stable (piggyBac-mediated transgenesis) system. Results: Transient endogenous expression of partial NH2 -terminus peptide from P. falciparum CSP in P. gallinaceum-infected Aedes aegypti resulted in a reduced number of sporozoites in the salivary glands. When a transgenic approach was used to express a partial CSP NH2 -terminal domain from P. gallinaceum the number of sporozoites in the salivary glands did not show a difference when compared to controls. However, a significant difference could be observed when mosquitoes with a lower infection were analysed. The same result could not be observed with mosquitoes endogenously expressing peptides based on the TSR domain from either P. gallinaceum or P. falciparum. Conclusion: These results support the conclusion that CSP partial NH2 -terminal domain can be endogenously expressed to promote a competition for the receptor used by sporozoites to invade salivary glands, and they could be used to block this interaction and reduce parasite transmission. The same effect cannot be obtained with peptides based on the TSR domain. [ABSTRACT FROM AUTHOR]- Published
- 2016
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16. Effects of a home-based intervention on diet and physical activity behaviours for rural adults with or at risk of metabolic syndrome: a randomised controlled trial.
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Blackford, Krysten, Jancey, Jonine, Lee, Andy H., James, Anthony, Howat, Peter, and Waddell, Tracy
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METABOLIC syndrome ,METABOLIC syndrome risk factors ,BEHAVIOR modification ,FOOD habits ,HEALTH behavior ,PROBABILITY theory ,QUESTIONNAIRES ,HOME environment ,RANDOMIZED controlled trials ,MOTIVATIONAL interviewing ,PHYSICAL activity ,DESCRIPTIVE statistics ,PREVENTION - Abstract
Background: This study aimed to determine whether a home-based 6-month lifestyle intervention program complemented by motivational interviewing could improve diet and physical activity behaviours in 50-69 year olds with or at risk of metabolic syndrome, residing in a disadvantaged rural Western Australian community. Methods: Participants from the City of Albany and surrounding towns (n = 401) were recruited into a 6 month randomised controlled trial. They were screened for metabolic syndrome and randomly allocated to intervention (n = 201) or control group (n = 200). Baseline and post-test data collection for both groups included a self-report questionnaire which incorporated the Fat and Fibre Barometer and the International Physical Activity Questionnaire Short Form. The intervention group received the program materials at baseline and the control group was waitlisted. Generalised estimating equation models assessed repeated outcome measures over time. Results: A total of 151 (75.1 %) intervention and 159 (79.5 %) control group participants completed post-test and were included in the analysis. After controlling for confounders, the intervention group achieved a marginally significant increase in their metabolic equivalent (MET) minutes of moderate intensity physical activity per week (p = 0.049), and significantly improved fibre intake (p < 0.001), fat intake (p = 0.003), and vegetable serves per day (p = 0.002) from baseline to post-test relative to the control group. Conclusion: A home-based, low-cost intervention with motivational support can effectively improve the physical activity and dietary behaviours of adults aged 50-69 years with or at risk of metabolic syndrome residing in a disadvantaged rural area. Trial registration: Anzctr.org.au Identifier: ACTRN12614000512628 [ABSTRACT FROM AUTHOR]
- Published
- 2016
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17. A randomised controlled trial of a physical activity and nutrition program targeting middle-aged adults at risk of metabolic syndrome in a disadvantaged rural community.
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Blackford, Krysten, Jancey, Jonine, Lee, Andy H., James, Anthony P., Howat, Peter, Hills, Andrew P., and Anderson, Annie
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LIFESTYLES & health ,METABOLIC syndrome ,TYPE 2 diabetes prevention ,CARDIOVASCULAR disease prevention ,PHYSICAL activity ,GERIATRIC nutrition ,PREVENTION - Abstract
Background: Approximately 70% of Australian adults aged over 50 are overweight or obese, with the prevalence significantly higher in regional/remote areas compared to cities. This study aims to determine if a low-cost, accessible lifestyle program targeting insufficiently active adults aged 50-69 y can be successfully implemented in a rural location, and whether its implementation will contribute to the reduction/prevention of metabolic syndrome, or other risk factors for type 2 diabetes, and cardiovascular disease. Methods/Design: This 6-month randomised controlled trial will consist of a nutrition, physical activity, and healthy weight intervention for 50-69 year-olds from a disadvantaged rural community. Five hundred participants with central obesity and at risk of metabolic syndrome will be recruited from Albany and surrounding areas in Western Australia (within a 50 kilometre radius of the town). They will be randomly assigned to either the intervention (n = 250) or wait-listed control group (n = 250). The theoretical concepts in the study utilise the Self-Determination Theory, complemented by Motivational Interviewing. The intervention will include a custom-designed booklet and interactive website that provides information, and encourages physical activity and nutrition goal setting, and healthy weight management. The booklet and website will be supplemented by an exercise chart, calendar, newsletters, resistance bands, accelerometers, and phone and email contact from program staff. Data will be collected at baseline and post-intervention. Discussion: This study aims to contribute to the prevention of metabolic syndrome and inter- related chronic illnesses: type 2 diabetes mellitus, cardiovascular disease, and some cancers; which are associated with overweight/ obesity, physical inactivity, and poor diet. This large rural community-based trial will provide guidelines for recruitment, program development, implementation, and evaluation, and has the potential to translate findings into practice by expanding the program to other regional areas in Australia. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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18. Molecular epidemiology of Plasmodium vivax and Plasmodium falciparum malaria among Duffy-positive and Duffy-negative populations in Ethiopia.
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Eugenia Lo, Yewhalaw, Delenasaw, Zhong, Daibin, Zemene, Endalew, Degefa, Teshome, Tushune, Kora, Ha, Margaret, Ming-Chieh Lee, James, Anthony A., and Yan, Guiyun
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PLASMODIUM vivax ,PLASMODIUM falciparum ,MOLECULAR epidemiology ,PUBLIC health ,CHEMOKINE receptors ,COMMUNICABLE disease diagnosis ,RIBOSOMAL RNA ,MALARIA treatment ,DIAGNOSIS - Abstract
Background: Malaria is the most prevalent communicable disease in Ethiopia, with 75% of the country's landmass classified as endemic for malaria. Accurate information on the distribution and clinical prevalence of Plasmodium vivax and Plasmodium falciparum malaria in endemic areas, as well as in Duffy-negative populations, is essential to develop integrated control strategies. Methods: A total of 390 and 416 community and clinical samples, respectively, representing different localities and age groups across Ethiopia were examined. Malaria prevalence was estimated using nested PCR of the 18S rRNA region. Parasite gene copy number was measured by quantitative real-time PCR and compared between symptomatic and asymptomatic samples, as well as between children/adolescents and adults from the local community. An approximately 500-bp segment of the human DARC gene was amplified and sequenced to identify Duffy genotype at the -33rd nucleotide position for all the clinical and community samples. Results: Plasmodium vivax prevalence was higher in the south while P. falciparum was higher in the north. The prevalence of P. vivax and P. falciparum malaria is the highest in children compared to adolescents and adults. Four P. vivax infections were detected among the Duffy-negative samples. Samples from asymptomatic individuals show a significantly lower parasite gene copy number than those from symptomatic infections for P. vivax and P. falciparum. Conclusions: Geographical and age differences influence the distribution of P. vivax and P. falciparum malaria in Ethiopia. These findings offer evidence-based guidelines in targeting malaria control efforts in the country. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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19. Integrated proteomic and transcriptomic analysis of the Aedes aegypti eggshell.
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Marinotti, Osvaldo, Tuan Ngo, Kojin, Bianca B., Shao-Pei Chou, Brian Nguyen, Juhn, Jennifer, Carballar-Lejarazú, Rebeca, Marinotti, Pedro N., Jiang, Xiaofang, Walter, Marika F., Zhijian Tu, Gershon, Paul D., and James, Anthony A.
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AEDES aegypti ,PROTEOMICS ,IN situ hybridization ,MEMBRANE proteins ,PROTEIN crosslinking - Abstract
Background Mosquito eggshells show remarkable diversity in physical properties and structure consistent with adaptations to the wide variety of environments exploited by these insects. We applied proteomic, transcriptomic, and hybridization in situ techniques to identify gene products and pathways that participate in the assembly of the Aedes aegypti eggshell. Aedes aegypti population density is low during cold and dry seasons and increases immediately after rainfall. The survival of embryos through unfavorable periods is a key factor in the persistence of their populations. The work described here supports integrated vector control approaches that target eggshell formation and result in Ae. aegypti drought-intolerant phenotypes for public health initiatives directed to reduce mosquito-borne diseases. Results A total of 130 proteins were identified from the combined mass spectrometric analyses of eggshell preparations. Conclusions Classification of proteins according to their known and putative functions revealed the complexity of the eggshell structure. Three novel Ae. aegypti vitelline membrane proteins were discovered. Odorant-binding and cysteine-rich proteins that may be structural components of the eggshell were identified. Enzymes with peroxidase, laccase and phenoloxidase activities also were identified, and their likely involvements in cross-linking reactions that stabilize the eggshell structure are discussed. [ABSTRACT FROM AUTHOR]
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- 2014
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20. Probing functional polymorphisms in the dengue vector, Aedes aegypti.
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Bonizzoni, Mariangela, Britton, Monica, Marinotti, Osvaldo, Dunn, William Augustine, Fass, Joseph, and James, Anthony A.
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GENETIC polymorphisms ,ARBOVIRUS diseases ,AEDES aegypti ,MOSQUITOES ,SINGLE nucleotide polymorphisms ,PEPTIDOGLYCANS - Abstract
Background Dengue is the most prevalent arboviral disease world-wide and its primary vector is the mosquito Aedes aegypti. The current lack of commercially-available vaccines makes control of vector populations the only effective strategy to prevent dengue transmission. Aedes aegypti geographic populations exhibit great variability in insecticide resistance and susceptibility to dengue infection. The characterization of single nucleotide polymorphisms (SNPs) as molecular markers to study quantitatively this variation is needed greatly because this species has a low abundance of microsatellite markers and limited known restriction fragments length polymorphisms (RFLPs) and single-strand conformation polymorphism (SSCP) markers. Results We used RNA-seq to characterize SNPs in three Ae. aegypti strains, including the Liverpool (LVP) strain, from which the current genome annotation is derived. We identified 131,764 unique genome locations with at least one alternative nucleotide to what is reported in the reference annotation. These comprised changes in both open-reading frames (ORFs) and untranslated regions (UTRs) of transcripts. An in depth-look at sequence variation in immunity genes revealed that those associated with autophagy, MD2-like receptors and Peptidoglycan Recognition Proteins had more sequence variation in their 3'UTRs than mutations associated with non-synonymous changes. This supports the conclusion that these genes had maintained their functional specificity while being adapted to different regulatory domains. In contrast, a number of peroxidases, serpins and Clip-domain serine proteases exhibited conservation of putative UTR regulatory sequences while displaying diversification of the ORFs. Transcriptome evidence also was found for ~2800 novel transcriptional units (NTUs) not annotated in the reference genome. Conclusions The transcriptome-wide assessment of within and inter-strain polymorphisms in Ae. aegypti adds considerably to the number of molecular markers available for genetic studies in this mosquito. Additionally, data supporting NTU discovery emphasizes the need for continuous amendments of the reference genome annotation. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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21. Development of a population suppression strain of the human malaria vector mosquito, Anopheles stephensi.
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Marinotti, Osvaldo, Jasinskiene, Nijole, Fazekas, Aniko, Scaife, Sarah, Fu, Guoliang, Mattingly, Stefanie T., Chow, Karissa, Brown, David M, Alphey, Luke, and James, Anthony A.
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MOSQUITOES ,DENGUE ,MALARIA ,INFECTIOUS disease transmission ,ANOPHELES stephensi - Abstract
Background: Transgenic mosquito strains are being developed to contribute to the control of dengue and malaria transmission. One approach uses genetic manipulation to confer conditional, female-specific dominant lethality phenotypes. Engineering of a female-specific flightless phenotype provides a sexing mechanism essential for male-only mosquito, release approaches that result in population suppression of target vector species. Methods: An approach that uses a female-specific gene promoter and antibiotic-repressible lethal factor to produce a sex-specific flightless phenotype was adapted to the human malaria vector, Anopheles stephensi. Transposon- and site-specific recombination-mediated technologies were used to generate a number of transgenic An. stephensi lines that when combined through mating produced the phenotype of flight-inhibited females and flight-capable males. Results: The data shown here demonstrate the successful engineering of a female-specific flightless phenotype in a malaria vector. The flightless phenotype was repressible by the addition of tetracycline to the larval diet. This conditional phenotype allows the rearing of the strains under routine laboratory conditions. The minimal level of tetracycline that rescues the flightless phenotype is higher than that found as an environmental contaminant in circumstances where there is intensive use of antibiotics. Conclusions: These studies support the further development of flightless female technology for applications in malaria control programmes that target the vectors. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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22. Expression and accumulation of the two-domain odorant-binding protein AaegOBP45 in the ovaries of blood-fed Aedes aegypti.
- Author
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Costa-da-Silva, André Luis, Kojin, Bianca B., Marinotti, Osvaldo, James, Anthony A., and Capurro, Margareth Lara
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GENE expression ,CARRIER proteins ,MOSQUITO vectors ,DENGUE ,DISEASE prevalence ,AEDES aegypti - Abstract
Background Aedes aegypti mosquitoes are the main vectors of dengue viruses. Despite global efforts to reduce the prevalence of dengue using integrated vector management strategies, innovative alternatives are necessary to help prevent virus transmission. Detailed characterizations of Ae. aegypti genes and their products provide information about the biology of mosquitoes and may serve as foundations for the design of new vector control methods. Findings We studied the Ae. aegypti gene, AAEL010714, that encodes a two-domain odorant-binding protein, AaegOBP45. The predicted gene structure and sequence were validated, although single nucleotide polymorphisms were observed. Transcriptional and translational products accumulate in the ovaries of blood fed females and are not detected or are at low abundance in other tissues. Conclusions We validated the Ae. aegypti AAEL010714 gene sequence and characterized the expression profile of a two-domain OBP expressed in ovaries. We propose that AaegOBP45 function as a component of the mosquito eggshell. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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23. RNA-seq analyses of blood-induced changes in gene expression in the mosquito vector species, Aedes aegypti.
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Bonizzoni, Mariangela, Dunn, W. Augustine, Campbell, Corey L., Olson, Ken E., Dimon, Michelle T., Marinotti, Osvaldo, and James, Anthony A.
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AEDES aegypti ,GENE expression ,VIRUSES ,MOSQUITO vectors ,NATURAL immunity - Abstract
Background: Hematophagy is a common trait of insect vectors of disease. Extensive genome-wide transcriptional changes occur in mosquitoes after blood meals, and these are related to digestive and reproductive processes, among others. Studies of these changes are expected to reveal molecular targets for novel vector control and pathogen transmission-blocking strategies. The mosquito Aedes aegypti (Diptera, Culicidae), a vector of Dengue viruses, Yellow Fever Virus (YFV) and Chikungunya virus (CV), is the subject of this study to look at genome-wide changes in gene expression following a blood meal. Results: Transcriptional changes that follow a blood meal in Ae. aegypti females were explored using RNA-seq technology. Over 30% of more than 18,000 investigated transcripts accumulate differentially in mosquitoes at five hours after a blood meal when compared to those fed only on sugar. Forty transcripts accumulate only in bloodfed mosquitoes. The list of regulated transcripts correlates with an enhancement of digestive activity and a suppression of environmental stimuli perception and innate immunity. The alignment of more than 65 million high-quality short reads to the Ae. aegypti reference genome permitted the refinement of the current annotation of transcript boundaries, as well as the discovery of novel transcripts, exons and splicing variants. Cis-regulatory elements (CRE) and cis-regulatory modules (CRM) enriched significantly at the 5'end flanking sequences of blood meal-regulated genes were identified. Conclusions: This study provides the first global view of the changes in transcript accumulation elicited by a blood meal in Ae. aegypti females. This information permitted the identification of classes of potentially coregulated genes and a description of biochemical and physiological events that occur immediately after blood feeding. The data presented here serve as a basis for novel vector control and pathogen transmission-blocking strategies including those in which the vectors are modified genetically to express anti-pathogen effector molecules. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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24. Spatial mapping of gene expression in the salivary glands of the dengue vector mosquito, aedes aegypti.
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Juhn, Jennifer, Naeem-Ullah, Unsar, Guedes, Bruno Augusto Maciel, Majid, Asif, Coleman, Judy, Pimenta, Paulo Filemon Paolucci, Akram, Waseem, James, Anthony Amade, and Marinotti, Osvaldo
- Subjects
GENE expression ,SALIVARY glands ,AEDES aegypti ,DENGUE ,GENES - Abstract
Background: Aedes aegypti mosquitoes are the main vectors of dengue viruses to humans. Understanding their biology and interactions with the pathogen are prerequisites for development of dengue transmission control strategies. Mosquito salivary glands are organs involved directly in pathogen transmission to vertebrate hosts. Information on the spatial distribution of gene expression in these organs is expected to assist in the development of novel disease control strategies, including those that entail the release of transgenic mosquitoes with impaired vector competence. Results: We report here the hybridization in situ patterns of 30 transcripts expressed in the salivary glands of adult Ae. aegypti females. Distinct spatial accumulation patterns were identified. The products of twelve genes are localized exclusively in the proximal-lateral lobes. Among these, three accumulate preferentially in the most anterior portion of the proximal-lateral lobe. This pattern revealed a salivary gland cell type previously undescribed in Ae. aegypti, which was validated by transmission electron microscopy. Five distinct gene products accumulate in the distal-lateral lobes and another five localize in the medial lobe. Seven transcripts are found in the distal-lateral and medial lobes. The transcriptional product of one gene accumulates in proximal- and distal-lateral lobes. Seven genes analyzed by quantitative PCR are expressed constitutively. The most abundant salivary gland transcripts are those localized within the proximal-lateral lobes, while previous work has shown that the distal-lateral lobes are the most active in protein synthesis. This incongruity suggests a role for translational regulation in mosquito saliva production. Conclusions: Transgenic mosquitoes with reduced vector competence have been proposed as tools for the control of dengue virus transmission. Expression of anti-dengue effector molecules in the distal-lateral lobes of Ae. aegypti salivary glands has been shown to reduce prevalence and mean intensities of viral infection. We anticipate greater efficiency of viral suppression if effector genes are expressed in all lobes of the salivary glands. Based on our data, a minimum of two promoters is necessary to drive the expression of one or more anti-dengue genes in all cells of the female salivary glands. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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25. aeGEPUCI: a database of gene expression in the dengue vector mosquito, Aedes aegypti.
- Author
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Dissanayake, Sumudu N., Ribeiro, Jose M. C., Mei-Hui Wang, Dunn, William A., Guiyun Yan, James, Anthony A., and Marinotti, Osvaldo
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AEDES aegypti ,DENGUE ,YELLOW fever ,VIRUSES ,GENOMES ,GENE expression ,MOSQUITOES ,DATA mining - Abstract
Background: Aedes aegypti is the principal vector of dengue and yellow fever viruses. The availability of the sequenced and annotated genome enables genome-wide analyses of gene expression in this mosquito. The large amount of data resulting from these analyses requires efficient cataloguing before it becomes useful as the basis for new insights into gene expression patterns and studies of the underlying molecular mechanisms for generating these patterns. Findings: We provide a publicly-accessible database and data-mining tool, aeGEPUCI, that integrates 1) microarray analyses of sex- and stage-specific gene expression in Ae. aegypti, 2) functional gene annotation, 3) genomic sequence data, and 4) computational sequence analysis tools. The database can be used to identify genes expressed in particular stages and patterns of interest, and to analyze putative cis-regulatory elements (CREs) that may play a role in coordinating these patterns. The database is accessible from the address http://www.aegep.bio. uci.edu. Conclusions: The combination of gene expression, function and sequence data coupled with integrated sequence analysis tools allows for identification of expression patterns and streamlines the development of CRE predictions and experiments to assess how patterns of expression are coordinated at the molecular level. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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26. Complete mtDNA genomes of Anopheles darlingi and an approach to anopheline divergence time.
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Moreno, Marta, Marinotti, Osvaldo, Krzywinski, Jaroslaw, Tadei, Wanderli P., James, Anthony A., Achee, Nicole L., and Conn, Jan E.
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ANOPHELES ,MALARIA ,PUBLIC health ,DNA - Abstract
Background: The complete sequences of the mitochondrial genomes (mtDNA) of members of the northern and southern genotypes of Anopheles (Nyssorhynchus) darlingi were used for comparative studies to estimate the time to the most recent common ancestor for modern anophelines, to evaluate differentiation within this taxon, and to seek evidence of incipient speciation. Methods: The mtDNAs were sequenced from mosquitoes from Belize and Brazil and comparative analyses of structure and base composition, among others, were performed. A maximum likelihood approach linked with phylogenetic information was employed to detect evidence of selection and a Bayesian approach was used to date the split between the subgenus Nyssorhynchus and other Anopheles subgenera. Results: The comparison of mtDNA sequences within the Anopheles darlingi taxon does not provide sufficient resolution to establish different units of speciation within the species. In addition, no evidence of positive selection in any protein-coding gene of the mtDNA was detected, and purifying selection likely is the basis for this lack of diversity. Bayesian analysis supports the conclusion that the most recent ancestor of Nyssorhynchus and Anopheles+Cellia was extant ∼94 million years ago. Conclusion: Analyses of mtDNA genomes of Anopheles darlingi do not provide support for speciation in the taxon. The dates estimated for divergence among the anopheline groups tested is in agreement with the geological split of western Gondwana (95 mya), and provides additional support for explaining the absence of Cellia in the New World, and Nyssorhynchus in the Afro-Eurasian continents. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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27. Prior exercise does not affect chylomicron particle number following a mixed meal of moderate fat content.
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James, Anthony P., Slivkoff-Clark, Karin, and Mamo, John C. L.
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- *
FASTING , *EXERCISE , *FEMALES , *FAT , *CARBOHYDRATES , *INGESTION - Abstract
Background: A single session of exercise has been reported to reduce fasting and postprandial triacylglycerol concentrations on the subsequent day. It is possible that exercise also reduces chylomicron particle number, which may underlie the observed reduction in postprandial triacylglycerol concentration. In the present study we aimed to determine whether a single session of exercise reduces fasting and postprandial chylomicron particle number on the subsequent day. In a randomised crossover design eight lean and healthy male and female subjects attended two postprandial testing days. On the previous day the subjects either performed 90 minutes of moderate intensity exercise or did not perform any exercise. Fasting blood samples were then collected prior to ingestion of a moderate fat mixed meal (0.44 g fat, 0.94 g carbohydrate, 0.27 g protein/kg body weight), blood was then collected after 1 h, 2 h, 4 h, 6 h, and 8 h. Results: The fasting and postprandial apolipoprotein B48 concentration (marker of chylomicron particle number) was not affected by prior exercise. However exercise reduced fasting triacylglycerol concentration by 16% (P < 0.05) and there was a trend towards a reduction in the total area under the postprandial triacylglycerol curve (23%; P = 0.053). However when corrected for baseline concentration postprandial triacylglycerol concentration was not affected by prior exercise. Conclusion: A single session of exercise of moderate intensity and 90 minutes duration reduces fasting triacylglycerol levels, however fasting and postprandial chylomicron particle number was unaffected. Furthermore it appears that previously observed reductions in postprandial triacylglycerol levels following exercise are only mediated following consumption of high, nonphysiologically relevant doses of fat. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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28. Comparison of isocaloric very low carbohydrate/high saturated fat and high carbohydrate/low saturated fat diets on body composition and cardiovascular risk.
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Noakes, Manny, Foster, Paul R., Keogh, Jennifer B., James, Anthony P., Mamo, John C., and Clifton, Peter M.
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LOW-carbohydrate diet ,CARDIOVASCULAR diseases ,BODY composition ,WEIGHT loss ,NUTRITION - Abstract
Background: It is speculated that high saturated fat very low carbohydrate diets (VLCARB) have adverse effects on cardiovascular risk but evidence for this in controlled studies is lacking. The objective of this study was to compare, under isocaloric conditions, the effects of a VLCARB to 2 low saturated fat high carbohydrate diets on body composition and cardiovascular risk. Methods: Eighty three subjects, 48 ± 8 y, total cholesterol 5.9 ± 1.0 mmol/L, BMI 33 ± 3 kg/m² were randomly allocated to one of 3 isocaloric weight loss diets (6 MJ) for 8 weeks and on the same diets in energy balance for 4 weeks: Very Low Fat (VLF) (CHO:Fat:Protein; %SF = 70:10:20; 3%), High Unsaturated Fat (HUF) = (50:30:20; 6%), VLCARB (4:61:35; 20%) Results: Percent fat mass loss was not different between diets VLCARB -4.5 ± 0.5, VLF-4.0 ± 0.5, HUF -4.4 ± 0.6 kg). Lean mass loss was 32-31% on VLCARB and VLF compared to HUF (21%) (P < 0.05). LDL-C increased significantly only on VLCARB by 7% (p < 0.001 compared with the other diets) but apoB was unchanged on this diet and HDL-C increased relative to the other 2 diets. Triacylglycerol was lowered by 0.73 ± 0.12 mmol/L on VLCARB compared to -0.15 ± 0.07 mmol/L on HUF and -0.06 ± 0.13 mmol/L on VLF (P < 0.001). Plasma homocysteine increased 6.6% only on VLCARB (P = 0.026). VLCARB lowered fasting insulin 33% compared to a 19% fall on HUF and no change on VLF (P < 0.001). The VLCARB meal also provoked significantly lower post prandial glucose and insulin responses than the VLF and HUF meals. All diets decreased fasting glucose, blood pressure and CRP (P < 0.05). Conclusion: Isocaloric VLCARB results in similar fat loss than diets low in saturated fat, but are more effective in improving triacylglycerols, HDL-C, fasting and post prandial glucose and insulin concentrations. VLCARB may be useful in the short-term management of subjects with insulin resistance and hypertriacylglycerolemia. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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29. The MB2 gene family of Plasmodium species has a unique combination of S1 and GTP-binding domains.
- Author
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Romero, Lisa C., Nguyen, Thanh V., Deville, Benoit, Ogunjumo, Oluwasanmi, and James, Anthony A.
- Subjects
PLASMODIUM falciparum genetics ,GUANOSINE triphosphate ,BINDING sites ,AMINO acids ,ANTIMALARIALS ,DRUG development - Abstract
Background: Identification and characterization of novel Plasmodium gene families is necessary for developing new anti-malarial therapeutics. The products of the Plasmodium falciparum gene, MB2, were shown previously to have a stage-specific pattern of subcellular localization and proteolytic processing. Results: Genes homologous to MB2 were identified in five additional parasite species, P. knowlesi, P. gallinaceum, P. berghei, P. yoelii, and P. chabaudi. Sequence comparisons among the MB2 gene products reveal amino acid conservation of structural features, including putative S1 and GTP-binding domains, and putative signal peptides and nuclear localization signals. Conclusions: The combination of domains is unique to this gene family and indicates that MB2 genes comprise a novel family and therefore may be a good target for drug development. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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30. Disrupted connectivity in schizophrenia: modelling the impact of structural connectivity changes on the dynamics of spontaneous functional networks.
- Author
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Cabral, Joana, Fernandes, Henrique, Hartevelt, Tim Van, James, Anthony, Kringelbach, Morten L., and Deco, Gustavo
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SCHIZOPHRENIA ,BIOLOGICAL neural networks - Abstract
An abstract of the article "Disrupted connectivity in schizophrenia: Modelling the impact of structural connectivity changes on the dynamics of spontaneous functional networks" by Joana Cabra and colleagues is presented.
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- 2013
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31. Functional analysis of Orco and odorant receptors in odor recognition in Aedes albopictus.
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Liu H, Liu T, Xie L, Wang X, Deng Y, Chen CH, James AA, and Chen XG
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- Animals, Behavior, Animal, Electrophysiological Phenomena, Female, Gene Expression Regulation physiology, HEK293 Cells, Humans, Insect Proteins genetics, Phylogeny, RNA Interference, Receptors, Odorant genetics, Aedes physiology, Insect Proteins metabolism, Odorants, Receptors, Odorant metabolism
- Abstract
Background: Aedes albopictus is a globally invasive mosquito and a major vector of arboviruses, including dengue, Zika and Chikungunya. Olfactory-related behaviors, particularly host-seeking, offer opportunities to disrupt the disease-transmission process. A better understanding of odorant receptors (ORs) may assist in explaining host selection and location, and contribute to novel strategy of vector control., Methods: Based on previous prediction of 158 putative odorant receptors by Ae. albopictus genome analysis, 29 AalORs were selected for tissue-specific expression profiles in the present study. AalOrco (AalOR7), AalOR10 and AalOR88, highly expressed in female olfactory tissues, were chosen for further structure predictions as well as functional validation including calcium imaging assay in human embryonic kidney (HEK293) cells and RNA interference assay in Ae. albopictus. We also conducted electrophysiological and behavioral assays in mosquitoes after RNA interference of the three genes to determine their roles in host-seeking., Results: The results support previous conclusions that individual conventional (ORXs) and Orco can form heteromeric complexes to recognize odorants and respond to components of human volatiles in HEK293 cells. The reduction of AalOrco transcript levels led to a significant decrease in host-seeking and confusion in host preference. In contrast, AalOR10 and AalOR88 knockdown mosquitoes showed no significant behavioral differences compared with controls. The functions of conventional ORs at least AalOR10 and AalOR88 are abolished with inhibited expression of the Orco gene orthologs, along with the concomitant relevant olfactory behavior., Conclusions: Combining structural and functional data, we conclude that the product of the Orco gene in this mosquito is crucial for transmitting olfactory signaling and conventional ORs contribute directly to odorant recognition. Our results provide insight into the linkage between odorant receptors and host-seeking in this important vector species.
- Published
- 2016
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32. Endogenously-expressed NH2-terminus of circumsporozoite protein interferes with sporozoite invasion of mosquito salivary glands.
- Author
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Kojin BB, Costa-da-Silva AL, Maciel C, Henriques DA, Carvalho DO, Martin K, Marinotti O, James AA, Bonaldo MC, and Capurro ML
- Subjects
- Aedes genetics, Animals, Female, Gene Expression, Protozoan Proteins genetics, Salivary Glands parasitology, Transgenes, Aedes parasitology, Cell Adhesion, Plasmodium falciparum physiology, Plasmodium gallinaceum physiology, Protozoan Proteins metabolism, Sporozoites physiology
- Abstract
Background: The circumsporozoite protein is the most abundant polypeptide expressed by sporozoites, the malaria parasite stage capable of infecting humans. Sporozoite invasion of mosquito salivary glands prior to transmission is likely mediated by a receptor/ligand-like interaction of the parasites with the target tissues, and the amino (NH2)-terminal portion of CSP is involved in this interaction but not the TSR region on the carboxyl (C)-terminus. Peptides based on the NH2-terminal domain could compete with the parasites for the salivary gland receptors and thus inhibit penetration., Methods: Peptides based on the NH2-terminus and TSR domains of the CSP from avian or human malaria parasites, Plasmodium gallinaceum and Plasmodium falciparum, respectively, were expressed endogenously in mosquito haemolymph using a transient (Sindbis virus-mediated) or stable (piggyBac-mediated transgenesis) system., Results: Transient endogenous expression of partial NH2-terminus peptide from P. falciparum CSP in P. gallinaceum-infected Aedes aegypti resulted in a reduced number of sporozoites in the salivary glands. When a transgenic approach was used to express a partial CSP NH2-terminal domain from P. gallinaceum the number of sporozoites in the salivary glands did not show a difference when compared to controls. However, a significant difference could be observed when mosquitoes with a lower infection were analysed. The same result could not be observed with mosquitoes endogenously expressing peptides based on the TSR domain from either P. gallinaceum or P. falciparum., Conclusion: These results support the conclusion that CSP partial NH2-terminal domain can be endogenously expressed to promote a competition for the receptor used by sporozoites to invade salivary glands, and they could be used to block this interaction and reduce parasite transmission. The same effect cannot be obtained with peptides based on the TSR domain.
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- 2016
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33. Molecular epidemiology of Plasmodium vivax and Plasmodium falciparum malaria among Duffy-positive and Duffy-negative populations in Ethiopia.
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Lo E, Yewhalaw D, Zhong D, Zemene E, Degefa T, Tushune K, Ha M, Lee MC, James AA, and Yan G
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- Adolescent, Child, Child, Preschool, Cross-Sectional Studies, Humans, Infant, Infant, Newborn, Molecular Epidemiology, Polymerase Chain Reaction, Prevalence, Duffy Blood-Group System genetics, Malaria, Falciparum epidemiology, Malaria, Falciparum genetics, Malaria, Falciparum parasitology, Malaria, Vivax epidemiology, Malaria, Vivax genetics, Malaria, Vivax parasitology, Plasmodium falciparum genetics, Plasmodium vivax genetics, Receptors, Cell Surface genetics
- Abstract
Background: Malaria is the most prevalent communicable disease in Ethiopia, with 75% of the country's landmass classified as endemic for malaria. Accurate information on the distribution and clinical prevalence of Plasmodium vivax and Plasmodium falciparum malaria in endemic areas, as well as in Duffy-negative populations, is essential to develop integrated control strategies., Methods: A total of 390 and 416 community and clinical samples, respectively, representing different localities and age groups across Ethiopia were examined. Malaria prevalence was estimated using nested PCR of the 18S rRNA region. Parasite gene copy number was measured by quantitative real-time PCR and compared between symptomatic and asymptomatic samples, as well as between children/adolescents and adults from the local community. An approximately 500-bp segment of the human DARC gene was amplified and sequenced to identify Duffy genotype at the -33rd nucleotide position for all the clinical and community samples., Results: Plasmodium vivax prevalence was higher in the south while P. falciparum was higher in the north. The prevalence of P. vivax and P. falciparum malaria is the highest in children compared to adolescents and adults. Four P. vivax infections were detected among the Duffy-negative samples. Samples from asymptomatic individuals show a significantly lower parasite gene copy number than those from symptomatic infections for P. vivax and P. falciparum., Conclusions: Geographical and age differences influence the distribution of P. vivax and P. falciparum malaria in Ethiopia. These findings offer evidence-based guidelines in targeting malaria control efforts in the country.
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- 2015
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34. The chronic effects of fish oil with exercise on postprandial lipaemia and chylomicron homeostasis in insulin resistant viscerally obese men.
- Author
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Slivkoff-Clark KM, James AP, and Mamo JC
- Abstract
Background: Visceral obesity and insulin resistance are associated with a postprandial accumulation of atherogenic chylomicron remnants that is difficult to modulate with lipid-lowering therapies. Dietary fish oil and exercise are cardioprotective interventions that can significantly modify the metabolism of TAG-rich lipoproteins. In this study, we investigated whether chronic exercise and fish oil act in combination to affect chylomicron metabolism in obese men with moderate insulin resistance., Methods: The single blind study tested the effect of fish oil, exercise and the combined treatments on fasting and postprandial chylomicron metabolism. Twenty nine men with metabolic syndrome were randomly assigned to take fish oil or placebo for four weeks, before undertaking an additional 12 week walking program. At baseline and at the end of each treatment, subjects were tested for concentrations of fasting apo B48, plasma lipids and insulin. Postprandial apo B48 and TAG kinetics were also determined following ingestion of a fat enriched meal., Results: Combining fish oil and exercise resulted in a significant reduction in the fasting apo B48 concentration, concomitant with attenuation of fasting TAG concentrations and the postprandial TAGIAUC response (p < 0.05). Fish oil by itself reduced the postprandial TAG response (p < 0.05) but not postprandial apo B48 kinetics. Individual treatments of fish oil and exercise did not correspond with improvements in fasting plasma TAG and apo B48., Conclusion: Fish oil was shown to independently improve plasma TAG homeostasis but did not resolve hyper-chylomicronaemia. Instead, combining fish oil with chronic exercise reduced the plasma concentration of pro-atherogenic chylomicron remnants; in addition it reduced the fasting and postprandial TAG response in viscerally obese insulin resistant subjects.
- Published
- 2012
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35. Characterization of immunoglobulin G antibodies to Plasmodium falciparum sporozoite surface antigen MB2 in malaria exposed individuals.
- Author
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Nguyen TV, Sacci JB Jr, de la Vega P, John CC, James AA, and Kang AS
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- Animals, Humans, Immunoblotting methods, Kenya, Antibodies, Protozoan blood, Antigens, Protozoan immunology, Immunoglobulin G blood, Malaria, Falciparum immunology, Plasmodium falciparum immunology, Protozoan Proteins immunology, Sporozoites immunology
- Abstract
Background: MB2 protein is a sporozoite surface antigen on the human malaria parasite Plasmodium falciparum. MB2 was identified by screening a P. falciparum sporozoite cDNA expression library using immune sera from a protected donor immunized via the bites of P. falciparum-infected irradiated mosquitoes. It is not known whether natural exposure to P. falciparum also induces the anti-MB2 response and if this response differs from that in protected individuals immunized via the bites of P. falciparum infected irradiated mosquitoes. The anti-MB2 antibody response may be part of a robust protective response against the sporozoite., Methods: Fragments of polypeptide regions of MB2 were constructed as recombinant fusions sandwiched between glutathione S-transferase and a hexa histidine tag for bacterial expression. The hexa histidine tag affinity purified proteins were used to immunize rabbits and the polyclonal sera evaluated in an in vitro inhibition of sporozoite invasion assay. The proteins were also used in immunoblots with sera from a limited number of donors immunized via the bites of P. falciparum infected irradiated mosquitoes and plasma and serum obtained from naturally exposed individuals in Kenya., Results: Rabbit polyclonal antibodies targeting the non-repeat region of the basic domain of MB2 inhibited sporozoites entry into HepG2-A16 cells in vitro. Analysis of serum from five human volunteers that were immunized via the bites of P. falciparum infected irradiated mosquitoes that developed immunity and were completely protected against subsequent challenge with non-irradiated parasite also had detectable levels of antibody against MB2 basic domain. In contrast, in three volunteers not protected, anti-MB2 antibodies were below the level of detection. Sera from protected volunteers preferentially recognized a non-repeat region of the basic domain of MB2, whereas plasma from naturally-infected individuals also had antibodies that recognize regions of MB2 that contain a repeat motif in immunoblots. Sequence analysis of eleven field isolates and four laboratory strains showed that these antigenic regions of the basic domain of the MB2 gene are highly conserved in parasites obtained from different parts of the world. Moreover, anti-MB2 antibodies also were detected in the plasma of 83% of the individuals living in a malaria endemic area of Kenya (n = 41)., Conclusion: A preliminary analysis of the human humoral response against MB2 indicates that it may be an additional highly conserved target for immune intervention at the pre-erythrocytic stage of P. falciparum life cycle.
- Published
- 2009
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36. angaGEDUCI: Anopheles gambiae gene expression database with integrated comparative algorithms for identifying conserved DNA motifs in promoter sequences.
- Author
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Dissanayake SN, Marinotti O, Ribeiro JM, and James AA
- Subjects
- Animals, Binding Sites genetics, Genes, Insect genetics, Molecular Sequence Data, RNA, Messenger genetics, RNA, Messenger metabolism, Transcription Factors metabolism, User-Computer Interface, Algorithms, Anopheles genetics, Conserved Sequence genetics, Databases, Genetic, Gene Expression Profiling, Promoter Regions, Genetic genetics, Regulatory Sequences, Nucleic Acid genetics
- Abstract
Background: The completed sequence of the Anopheles gambiae genome has enabled genome-wide analyses of gene expression and regulation in this principal vector of human malaria. These investigations have created a demand for efficient methods of cataloguing and analyzing the large quantities of data that have been produced. The organization of genome-wide data into one unified database makes possible the efficient identification of spatial and temporal patterns of gene expression, and by pairing these findings with comparative algorithms, may offer a tool to gain insight into the molecular mechanisms that regulate these expression patterns., Description: We provide a publicly-accessible database and integrated data-mining tool, angaGEDUCI, that unifies 1) stage- and tissue-specific microarray analyses of gene expression in An. gambiae at different developmental stages and temporal separations following a bloodmeal, 2) functional gene annotation, 3) genomic sequence data, and 4) promoter sequence comparison algorithms. The database can be used to study genes expressed in particular stages, tissues, and patterns of interest, and to identify conserved promoter sequence motifs that may play a role in the regulation of such expression. The database is accessible from the address http://www.angaged.bio.uci.edu., Conclusion: By combining gene expression, function, and sequence data with integrated sequence comparison algorithms, angaGEDUCI streamlines spatial and temporal pattern-finding and produces a straightforward means of developing predictions and designing experiments to assess how gene expression may be controlled at the molecular level.
- Published
- 2006
- Full Text
- View/download PDF
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