Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
J Invertebr Pathol ; 169: 107303, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31812561

RESUMO

Nosema maddoxi Becnel, Solter, Hajek, Huang, Sanscrainte, & Estep, a microsporidian species native to the United States, has been found infecting the invasive brown marmorated stink bug, Halyomorpha halys (Stål). Microsporidian infections in insects often shorten lifespans, decrease fecundity, prolong development, and stunt growth. This study was conducted to determine the impact of N. maddoxi on H. halys fitness. Adult females (2 doses) and nymphs (1 dose) drank suspensions of N. maddoxi spores to promote infection. Adult females receiving a high dose died faster than the controls. Nosema maddoxi infections impacted female egg production and egg viability at both doses compared with the controls. Infections were transmitted to 34.9% of adult males caged with infected females. As the number of days after inoculation increased, infection intensity (# spores found within an infected individual) for both adult treatments transitioned from low-intensity to high-intensity. Infected nymphs died significantly sooner than the controls. Of the treated nymphs, 55.9% died before molting into the fourth instar and only 26.5% eclosed to adults. Nymphal development rate and size were not impacted by N. maddoxi infection. These results indicate that N. maddoxi infection can negatively impact the lifespan of adult females, female fecundity, egg viability, and nymphal survival, which we hypothesize would negatively impact H. halys population densities.


Assuntos
Heterópteros/parasitologia , Controle de Insetos , Nosema/fisiologia , Controle Biológico de Vetores , Animais , Feminino , Fertilidade , Heterópteros/crescimento & desenvolvimento , Longevidade , Masculino , Ninfa/crescimento & desenvolvimento , Ninfa/parasitologia
2.
J Nutr ; 149(3): 406-415, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30770543

RESUMO

BACKGROUND: It has been proposed that the fetus prioritizes iron for hemoglobin production over delivery to tissues. However, few studies have evaluated the interrelations between hemoglobin and multiple iron status biomarkers in umbilical cord blood. A full understanding is needed of how these parameters influence each other within cord blood to fully interpret iron and hematologic status at birth. OBJECTIVES: We evaluated the determinants of neonatal hemoglobin and assessed the interrelations between hemoglobin, serum iron status indicators, and serum iron regulatory hormones in healthy neonates. METHODS: This was an observational study that assessed umbilical cord hemoglobin (Hb), serum ferritin (SF), erythropoietin (EPO), soluble transferrin receptor (sTfR), serum iron, hepcidin, vitamin B-12, folate, IL-6, and CRP measured in 234 neonates born to adolescents or to women carrying multiples. Correlations between these indicators were evaluated and mediation models consistent with the observed significant determinants of cord Hb concentrations were developed. RESULTS: A highly significant inverse association was found between cord SF and Hb concentrations that was not attributable to neonatal or maternal inflammation (as measured by IL-6 and CRP). The inverse association was present in the combined cohort, as well as in the adolescent and multiples cohorts independently. Mediation analyses found that EPO and hepcidin had significant indirect effects on cord Hb, associations that are explicable by mediation through SF and sTfR. CONCLUSION: In contrast to observations made in older infants, a highly significant inverse association between Hb and SF, as well positive associations between Hb and both sTfR and EPO, were observed in umbilical cord blood from neonates born to adolescents or women carrying multiples. These findings, combined with review of the published literature, indicate a need for analysis of the relations between multiple parameters to assess iron and hematologic status at birth. These clinical trials were registered at clinicaltrials.gov as NCT01582802 (https://clinicaltrials.gov/ct2/show/NCT01582802) and NCT01019902 (https://clinicaltrials.gov/ct2/show/NCT01019902).


Assuntos
Ferritinas/sangue , Sangue Fetal/química , Hemoglobinas/metabolismo , Deficiências de Ferro , Gravidez Múltipla , Adolescente , Adulto , Biomarcadores/sangue , Feminino , Humanos , Recém-Nascido , Inflamação/sangue , Inflamação/metabolismo , Masculino , Gravidez
3.
J Surg Res ; 242: 264-269, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31108344

RESUMO

BACKGROUND: Resident work hour restrictions and required protected didactic time limit their ability to perform clinical duties and participate in structured education. Advanced practice providers (APPs) have previoulsy been shown to positively impact patients' outcomes and overall hospital costs. We describe a model in which nurse practitioners (NPs) improve resident education and American Board of Surgery In Training Examination (ABSITE) scores by providing support to our trauma and acute care surgery (ACS) service thereby protecting resident didactic time. MATERIALS AND METHODS: A new educational model aimed to improve ABSITE scores was created, increasing protected resident didactic time. The addition of three full-time NPs to the ACS service allowed implementation of this redesigned academic curriculum to be put into effect without neglecting patient or service-related responsibilities that were previously fulfilled by resident staff. Resident ABSITE results including standard score, percent correct, and percentile were compared before and after the educational changes were instituted. RESULTS: Eleven residents' scores were included. For each ABSITE score, we used a mixed model with time and postgraduate year (PGY) level as fixed effects and subject ID as a random effect. The interaction term between PGY level and time was not significant and removed from the model. A significant main effect of PGY level and of time was then observed. A statistically significant improvement in ABSITE scores after intervention was observed across all the PGY levels. Standard score increased 77.3 points (P-value = 0.001), percent correct increased 5.9% (P-value = 0.002), and percentile increased 23.8 (P-value = 0.02). Following the educational reform, no residents scored below the 35th percentile. CONCLUSIONS: Utilization of NPs on our ACS service provided adequate service coverage, allowing the implementation of an educational reform increasing protected resident education time and improved ABSITE scores.


Assuntos
Cirurgia Geral/educação , Internato e Residência/métodos , Modelos Educacionais , Profissionais de Enfermagem/organização & administração , Carga de Trabalho/normas , Avaliação Educacional/estatística & dados numéricos , Hospitais de Ensino/organização & administração , Hospitais de Ensino/normas , Humanos , Internato e Residência/normas , Internato e Residência/estatística & dados numéricos , Designação de Pessoal/organização & administração , Estudos Retrospectivos , Fatores de Tempo , Centros de Traumatologia/organização & administração , Centros de Traumatologia/normas , Estados Unidos
4.
J Nutr ; 148(11): 1716-1722, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30247706

RESUMO

Background: Hepcidin is a systemic regulator of iron homeostasis. Little is known about the relative role of maternal compared with cord hepcidin on neonatal iron homeostasis. Objective: This study was undertaken to evaluate inter- and intrauterine variance in neonatal iron status, vitamin B-12, folate, and inflammatory markers in a cohort of twins (n = 50), triplets (n = 14), and quadruplets (n = 1) born to 65 women. Methods: Umbilical cord blood was obtained from 144 neonates born at 34.8 ± 2.7 wk of gestation with a mean birth weight of 2236 ± 551 g (means ± SDs). Cord hemoglobin and cord serum measures of ferritin (SF), soluble transferrin receptor (sTfR), hepcidin, erythropoietin (EPO), iron, vitamin B-12, folate, interleukin 6, and C-reactive protein were evaluated. Results: Intraclass correlation coefficient (ICC) analyses were used to examine inter- and intrauterine variance in neonatal iron indicators. A greater variability in cord hepcidin (ICC = 0.39) was found between siblings. Cord hepcidin had the greatest association with cord iron indicators because cord hepcidin alone captured 63.8%, 48.4%, 44.4%, and 31.3% of the intrauterine variance in cord hemoglobin, SF, sTfR, and EPO, respectively, whereas maternal hepcidin had no effect on cord iron indicators. Significantly greater differences in cord SF (P = 0.03), sTfR (P = 0.03), hepcidin (P = 0.0003), and EPO (P = 0.03) were found between di- and trichorionic siblings than between monochorionic siblings. In contrast, cord folate (ICC = 0.79) and vitamin B-12 (ICC = 0.74) exhibited a greater variability between unrelated neonates. Conclusions: In summary, fetally derived hepcidin might have more control on intrauterine variance in iron indicators than maternal hepcidin and appears to be capable of regulating fetal iron status independently of maternal hepcidin. The use of a multiple-birth model provides a unique way to identify factors that may contribute to placental nutrient transport and iron stores at birth.


Assuntos
Sangue Fetal , Hepcidinas/sangue , Ferro/sangue , Prole de Múltiplos Nascimentos , Adulto , Feminino , Humanos , Recém-Nascido , Masculino , Estado Nutricional , Gravidez
5.
J Nutr ; 148(6): 868-875, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29796622

RESUMO

Background: Interpretation of serum vitamin D biomarkers across pregnancy is complex due to limited understanding of pregnancy adaptations in vitamin D metabolism. During pregnancy, both gestational age and serum 25-hydroxyvitamin D [25(OH)D] concentrations may influence the concentrations of 1,25-dihydroxyvitamin D [1,25(OH)2D], 24,25-dihydroxyvitamin D [24,25(OH)2D], and parathyroid hormone (PTH). Objective: We aimed to identify predictors of change in serum 25(OH)D across gestation in pregnant adolescents and to assess the contribution made by cholecalciferol (vitamin D3) supplementation. We sought to determine whether gestational age and 25(OH)D concentration interacted to affect serum 1,25(OH)2D, 24,25(OH)2D, or PTH. Methods: Pregnant adolescents (n = 78, 59% African American, mean ± SD age: 17 ± 1 y) living in Rochester, NY (latitude 43°N) were supplemented with 200 IU or 2000 IU vitamin D3/d and allowed to continue their daily prenatal supplement that contained 400 IU vitamin D3. Serum was collected at study entry (18 ± 5 wk of gestation), halfway through study participation, and at delivery (40 ± 2 wk). Serum concentrations of the biochemical markers were modeled with linear mixed-effects regression models. Results: Vitamin D3 supplement intake and season of delivery determined change in 25(OH)D across pregnancy. Fall-winter delivery was associated with a decline in 25(OH)D unless vitamin D3 supplement intake was >872 IU/d. The interaction of gestational age and 25(OH)D affected 24,25(OH)2D concentrations. For a given 25(OH)D concentration, model-predicted serum 24,25(OH)2D increased across gestation except when 25(OH)D was <13 ng/mL. Below this threshold, 24,25(OH)2D was predicted to decline over time. Mean serum 1,25(OH)2D was elevated (>100 pg/mL) throughout the study. Conclusion: Our results suggest that when maternal serum 25(OH)D was low, its catabolism into 24,25(OH)2D decreased or remained stable as pregnancy progressed in order to maintain persistently elevated serum 1,25(OH)2D. Furthermore, in adolescents living at latitude 43°N, standard prenatal supplementation did not prevent a seasonal decline in 25(OH)D during pregnancy. This study was registered at clinicaltrials.gov as NCT01815047.


Assuntos
Colecalciferol/administração & dosagem , Colecalciferol/farmacologia , Idade Gestacional , Vitamina D/análogos & derivados , Adolescente , Biomarcadores , Relação Dose-Resposta a Droga , Feminino , Humanos , Gravidez , Vitamina D/sangue
6.
J Nutr ; 148(2): 259-266, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29490102

RESUMO

Background: Although self-efficacy is a potential determinant of feeding and care behaviors, there is limited empirical analysis of the role of maternal self-efficacy in low- and middle-income countries. In the context of behavior change interventions (BCIs) addressing complementary feeding (CF), it is possible that maternal self-efficacy can mediate or enhance intervention impacts. Objective: In the context of a BCI in Bangladesh, we studied the role of maternal self-efficacy for CF (MSE-CF) for 2 CF behaviors with the use of a theoretically grounded empirical model of determinants to illustrate the potential roles of MSE-CF. Methods: We developed and tested a locally relevant scale for MSE-CF and included it in a survey (n = 457 mothers of children aged 6-24 mo) conducted as part of a cluster-randomized evaluation. Qualitative research was used to inform the selection of 2 intervention-targeted behaviors: feeding green leafy vegetables in the last 24 h (GLV) and on-time introduction of egg (EGG) between 6 and 8 mo of age. We then examined direct, mediated, and potentiated paths of MSE-CF in relation to the impacts of the BCI on these behaviors with the use of regression and structural equation modeling. Results: GLV and EGG were higher in the intensive group than in the nonintensive control group (16.0 percentage points for GLV; P < 0.001; 11.2 percentage points for EGG; P = 0.037). For GLV, MSE-CF mediated (ß = 0.345, P = 0.010) and potentiated (ß = 0.390, P = 0.038) the effect of the intensive group. In contrast, MSE-CF did not mediate or potentiate the effect of the intervention on EGG. Conclusions: MSE-CF was a significant mediator and potentiator for GLV but not for EGG. The divergent findings highlight the complex determinants of individual specific infant and young child feeding behaviors. The study shows the value of measuring behavioral determinants, such as MSE-CF, that affect a caregiver's capability to adopt intervention-targeted behaviors.


Assuntos
Fenômenos Fisiológicos da Nutrição do Lactente , Comportamento Materno/psicologia , Autoeficácia , Adulto , Bangladesh , Terapia Comportamental , Pré-Escolar , Estudos Transversais , Ovos , Comportamento Alimentar , Feminino , Humanos , Renda , Lactente , Masculino , Mães , Pobreza , Verduras
7.
BMC Pregnancy Childbirth ; 17(1): 361, 2017 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-29037190

RESUMO

BACKGROUND: Antenatal care (ANC) is an important health service for women in developing countries, with numerous proven benefits. Global coverage of ANC has steadily increased over the past 30 years, in part due to increased community-based outreach. However, commensurate improvements in health outcomes such as reductions in the prevalence of maternal anemia and infants born small-for-gestational age have not been achieved, even with increased coverage, indicating that quality of care may be inadequate. Mobile clinics are one community-based strategy used to further improve coverage of ANC, but their quality of care delivery has rarely been evaluated. METHODS: To determine the quality of care of ANC in central Haiti, we compared adherence to national guidelines between fixed and mobile clinics by performing direct observations of antenatal care consultations and exit interviews with recipients of care using a multi-stage random sampling procedure. Outcome variables were eight components of care, and women's knowledge and perception of care quality. RESULTS: There were significant differences in the predicted proportion or probability of recommended services for four of eight care components, including intake, laboratory examinations, infection control, and supplies, iron folic acid supplements and Tetanus Toxoid vaccine provided to women. These care components were more likely performed in fixed clinics, except for distribution of supplies, iron-folic acid supplements, and Tetanus Toxoid vaccine, more likely provided in mobile clinics. There were no differences between clinic type for the proportion of total physical exam procedures performed, health and communication messages delivered, provider communication or documentation. Women's knowledge about educational topics was poor, but women perceived extremely high quality of care in both clinic models. CONCLUSIONS: Although adherence to guidelines differed by clinic type for half of the care components, both clinics had a low percentage of overall services delivered. Efforts to improve provider performance and quality are therefore needed in both models. Mobile clinics must deliver high-quality ANC to improve health and nutrition outcomes.


Assuntos
Instituições de Assistência Ambulatorial/normas , Atenção à Saúde/normas , Unidades Móveis de Saúde/normas , Cuidado Pré-Natal/normas , Qualidade da Assistência à Saúde , Atenção à Saúde/métodos , Feminino , Fidelidade a Diretrizes/estatística & dados numéricos , Haiti , Humanos , Gravidez
8.
J Public Health (Oxf) ; 39(4): 863-873, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-28069993

RESUMO

Background: Understanding health beliefs and how they influence willingness will enable the development of targeted curricula that maximize public engagement in Alzheimer's disease (AD) risk reduction behaviors. Methods: Literature on behavioral theory and community input was used to develop and validate a health beliefs survey about AD risk reduction among 428 community-dwelling adults. Principal component analysis was performed to assess internal consistency. Linear regression was performed to identify key predictors of Willingness to engage in AD risk reduction behaviors. Results: The measure as well as the individual scales (Benefits, Barriers, Severity, Susceptibility and Social Norm) were found to be internally consistent. Overall, as Benefits and Barriers scores increased, Willingness scores also increased. Those without prior AD experience or family history had lower willingness scores. Finally, we observed an interaction between age and norms, suggesting that social factors related to AD prevention may differentially affect people of different ages. Conclusions: The Alzheimer Prevention Beliefs Measure provides assessment of several health belief factors related to AD prevention. Age, Family History, Logistical Barriers and total Benefits are significant determinants of willingness to engage in AD risk reduction behaviors, such as seeing a doctor or making a lifestyle change.


Assuntos
Doença de Alzheimer/prevenção & controle , Doença de Alzheimer/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Medição de Risco/métodos , Medição de Risco/normas , Inquéritos e Questionários/normas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Pesquisa Participativa Baseada na Comunidade , Etnicidade , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal , Comportamento de Redução do Risco , Autorrelato/normas , Adulto Jovem
9.
J Am Coll Nutr ; 34(3): 199-204, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25751019

RESUMO

OBJECTIVES: If being weighed impacts perceptions of eating behavior, it is important that the order of questionnaires and weighing be considered in research and practice. A quasi-experimental study was performed to examine whether being weighed immediately prior to completing a questionnaire affects responses to eating behavior questions. It was hypothesized that being weighed would serve as a priming stimulus and increase measures of dietary restraint, disinhibition, and hunger. METHODS: Trained researchers collected a sample of volunteers (n = 355) in 8 locations in the United States on two Saturdays in the summer of 2011. Half of the participants were weighed immediately prior to completing the Three Factor Eating Questionnaire (TFEQ), with the remaining half weighed immediately after TFEQ completion. RESULTS: A priori hypotheses were not supported despite replicating known relationships between weight, dietary restraint and disinhibition. Results indicated that being weighed first produced a difference in differences on disinhibition scores between low restraint score (95% CI = 4.65-6.02) and high restraint score (95% CI = 6.11-7.57) compared to being weighed after questionnaire completion (p = 0.003). However, this relationship was not significant when modeling restraint as a continuous variable, questioning the use of dichotomization. CONCLUSIONS: Being weighed is unlikely to be a strong enough prime to significantly change scores on eating behavior questionnaires for everyone, but may allow differences in restraint status to become more evident. Researchers assessing dietary restraint should be wary of the possibility of producing different results when treating restraint as continuous or dichotomous, which could lead to different interpretations.


Assuntos
Peso Corporal , Comportamento Alimentar/psicologia , Inquéritos e Questionários , Adulto , Feminino , Humanos , Fome , Inibição Psicológica , Masculino , Percepção , Autorrelato , Fatores de Tempo , Estados Unidos
10.
FASEB J ; 27(3): 1245-53, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23195033

RESUMO

This study investigated the influence of maternal choline intake on the human placental transcriptome, with a special interest in its role in modulating placental vascular function. Healthy pregnant women (n=26, wk 26-29 gestation) were randomized to 480 mg choline/d, an intake level approximating the adequate intake of 450 mg/d, or 930 mg/d for 12 wk. Maternal blood and placental samples were retrieved at delivery. Whole genome expression microarrays were used to identify placental genes and biological processes impacted by maternal choline intake. Maternal choline intake influenced a wide array of genes (n=166) and biological processes (n=197), including those related to vascular function. Of special interest was the 30% down-regulation (P=0.05) of the antiangiogenic factor and preeclampsia risk marker fms-like tyrosine kinase-1 (sFLT1) in the placenta tissues obtained from the 930 vs. 480 mg/d choline intake group. Similar decreases (P=0.04) were detected in maternal blood sFLT1 protein concentrations. The down-regulation of sFLT1 by choline treatment was confirmed in a human trophoblast cell culture model and may be related to enhanced acetylcholine signaling. These findings indicate that supplementing the maternal diet with extra choline may improve placental angiogenesis and mitigate some of the pathological antecedents of preeclampsia.


Assuntos
Inibidores da Angiogênese/sangue , Colina/administração & dosagem , Suplementos Nutricionais , Neovascularização Fisiológica/fisiologia , Terceiro Trimestre da Gravidez/sangue , Gravidez/sangue , Trofoblastos/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/sangue , Acetilcolina/sangue , Adulto , Biomarcadores/sangue , Células Cultivadas , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/fisiologia , Estudo de Associação Genômica Ampla , Humanos , Neovascularização Fisiológica/efeitos dos fármacos , Pré-Eclâmpsia/sangue , Fatores de Risco , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Nascimento a Termo/sangue , Transcriptoma/efeitos dos fármacos , Transcriptoma/fisiologia , Trofoblastos/citologia
11.
FASEB J ; 26(8): 3563-74, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22549509

RESUMO

The in utero availability of methyl donors, such as choline, may modify fetal epigenetic marks and lead to sustainable functional alterations throughout the life course. The hypothalamic-pituitary-adrenal (HPA) axis regulates cortisol production and is sensitive to perinatal epigenetic programming. As an extension of a 12-wk dose-response choline feeding study conducted in third-trimester pregnant women, we investigated the effect of maternal choline intake (930 vs. 480 mg/d) on the epigenetic state of cortisol-regulating genes, and their expression, in placenta and cord venous blood. The higher maternal choline intake yielded higher placental promoter methylation of the cortisol-regulating genes, corticotropin releasing hormone (CRH; P=0.05) and glucocorticoid receptor (NR3C1; P=0.002); lower placental CRH transcript abundance (P=0.04); lower cord blood leukocyte promoter methylation of CRH (P=0.05) and NR3C1 (P=0.04); and 33% lower (P=0.07) cord plasma cortisol. In addition, placental global DNA methylation and dimethylated histone H3 at lysine 9 (H3K9me2) were higher (P=0.02) in the 930 mg choline/d group, as was the expression of select placental methyltransferases. These data collectively suggest that maternal choline intake in humans modulates the epigenetic state of genes that regulate fetal HPA axis reactivity as well as the epigenomic status of fetal derived tissues.


Assuntos
Colina/administração & dosagem , Epigênese Genética/efeitos dos fármacos , Hidrocortisona/biossíntese , Fenômenos Fisiológicos da Nutrição Materna/fisiologia , Adulto , Hormônio Liberador da Corticotropina/metabolismo , Metilação de DNA , Feminino , Sangue Fetal/metabolismo , Humanos , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/fisiologia , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/fisiologia , Placenta/metabolismo , Gravidez , Terceiro Trimestre da Gravidez , Receptores de Glucocorticoides/metabolismo
12.
J Exp Biol ; 216(Pt 2): 218-23, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22996441

RESUMO

Associative learning has been shown in a variety of insects, including the mosquitoes Culex quinquefasciatus and Anopheles gambiae. This study demonstrates associative learning for the first time in Aedes aegypti, an important vector of dengue, yellow fever and chikungunya viruses. This species prefers to rest on dark surfaces and is attracted to the odor of 1-octen-3-ol. After training in which a dark surface alone or a dark surface with odor was paired with electric shock, mosquitoes avoided the previously attractive area. The association was stronger when odor was included in training, was retained for at least 60 min but not for 24 h, and was equal for males and females. These results demonstrate the utility of a bulk-training paradigm for mosquitoes similar to that used with Drosophila melanogaster.


Assuntos
Aedes/fisiologia , Cor , Insetos Vetores/fisiologia , Octanóis/metabolismo , Animais , Aprendizagem da Esquiva , Condicionamento Operante , Dengue/transmissão , Eletrochoque , Feminino , Humanos , Masculino , Odorantes/análise , Propriedades de Superfície
13.
Am J Psychol ; 126(3): 335-54, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24027947

RESUMO

College students were presented with 4 events to be explained. Each event was accompanied by either a target explanation or a target and an alternative, and all explanations were causal mechanistic. For each event, participants were also presented with 12 pieces of information. Four of the 12 pieces were causally consistent with the target, 4 with the alternative, and 4 were neutral. Participants were assigned to one of 3 strategy conditions, depending on what they were explicitly told to do: confirm, disconfirm, or evaluate the target explanation. People told to disconfirm were more likely than people in the other conditions to cite, as strategy appropriate, information that was in fact neutral. In addition, across strategy conditions, the presence of an alternative decreased the likelihood of identifying, as appropriate to the strategy, information that was strategy inappropriate. Results are discussed in terms of inference to the best explanation and in terms of confirmation bias.


Assuntos
Cognição/fisiologia , Lógica , Resolução de Problemas/fisiologia , Adolescente , Feminino , Humanos , Masculino , Adulto Jovem
14.
Am J Clin Nutr ; 114(1): 330-337, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33829247

RESUMO

BACKGROUND: Heavy parasitic loads increase the risk of iron (Fe) deficiency anemia, which remains prevalent globally. Where parasites are common, understanding the influence of parasitic infections on Fe incorporation and erythropoiesis in toddlers is especially important. OBJECTIVES: The aim of this study was to identify the impacts of malarial and helminth infections on red blood cell (RBC) Fe incorporation and subsequent changes in RBC Fe isotope enrichment for 84 days postdosing in toddlers at high risk for parasitic infections. METHODS: Fe incorporation was measured in a group of Zanzibari toddlers (n = 71; 16-25 months) using a stable Fe isotopic method. At study entry, an oral stable Fe isotope was administered. Blood was collected 14 (D14) and 84 (D84) days postdosing for the assessment of Fe status indicators and RBC isotopic enrichment. Blood and stool samples were collected and screened for malaria and helminth parasites. Factors associated with changes in RBC Fe isotope enrichment were identified using regression models. RESULTS: Toddlers who had larger weight-for-age z-scores, lower total body Fe, and helminth infections (n = 26) exhibited higher RBC Fe incorporation. RBC Fe isotope enrichment decreased from D14 to D84 by -2.75 percentage points (P < 0.0001; n = 66). Greater loss in RBC Fe isotope enrichment from D14 to D84 was observed in those who received Fe supplementation, those with either helminths or both malarial and helminth infections, and in those with greater RBC Fe incorporation on D14. CONCLUSIONS: Toddlers who received Fe supplementation exhibited significantly greater losses of RBC Fe isotope enrichment over time. We speculate this greater loss of RBC Fe enrichment is indicative of increased erythropoiesis due to the provision of Fe among anemic or helminth-infected toddlers.


Assuntos
Anemia Ferropriva/prevenção & controle , Suplementos Nutricionais , Eritrócitos/química , Ferro/administração & dosagem , Ferro/metabolismo , Anemia Ferropriva/etiologia , Peso Corporal , Pré-Escolar , Eritrócitos/metabolismo , Eritrócitos/parasitologia , Feminino , Helmintíase/complicações , Humanos , Lactente , Isótopos de Ferro , Malária/complicações , Masculino , Parasitemia , Tanzânia/epidemiologia
15.
J Nutr ; 140(5): 975-80, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20220206

RESUMO

Severe choline deficiency adversely affects cellular methylation and DNA integrity, with potentially serious implications for disease risk. As part of a 12-wk controlled choline intervention study conducted in folate-compromised Mexican-American men (n = 60; 18-55 y) differing in the methylenetetrahydrofolate reductase (MTHFR) C677T genotype (21 677CC, 29 677TT), this study evaluated the effects of varied choline intakes (300, 550, 1100, and 2200 mg/d) on the change (i.e. wk 12-0) in markers of cellular methylation and DNA integrity. Choline intake affected the change in plasma S-adenosylmethionine (P = 0.044), with decreases tending to be greater (P < or = 0.08) in the 300 and 550 mg/d groups than in the 2200 mg/d group. Choline intake also interacted with the MTHFR C677T genotype to affect the change in genomic DNA methylation and DNA damage. In men with the MTHFR 677CC genotype, choline intake affected (P = 0.007) the change in DNA methylation, with a greater decrease (P < 0.02) in the 300 mg/d group than in the 1100 and 2200 mg/d groups. In men with the MTHFR 677CC genotype, choline intake also affected (P = 0.047) the change in DNA damage, with the increase tending to be greater (P = 0.07) in the 550 mg/d group than in the 2200 mg/d group. Choline intake did not affect these variables in men with the MTHFR 677TT genotype. Overall, these data suggest that choline intake exceeding current dietary recommendations preserves markers of cellular methylation and attenuates DNA damage in a genetic subgroup of folate-compromised men.


Assuntos
Deficiência de Colina/genética , Colina/uso terapêutico , Dano ao DNA/efeitos dos fármacos , Metilação de DNA/efeitos dos fármacos , Deficiência de Ácido Fólico/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo Genético , Adolescente , Adulto , Colina/administração & dosagem , Colina/farmacologia , Deficiência de Colina/complicações , Dieta , Relação Dose-Resposta a Droga , Deficiência de Ácido Fólico/dietoterapia , Marcadores Genéticos , Genótipo , Humanos , Masculino , Americanos Mexicanos , Pessoa de Meia-Idade , Política Nutricional , Necessidades Nutricionais , S-Adenosilmetionina/sangue , Adulto Jovem
16.
Am J Clin Nutr ; 112(5): 1358-1367, 2020 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-32766885

RESUMO

BACKGROUND: Histidine is an essential amino acid with health benefits that may warrant histidine supplementation; however, the clinical safety of histidine intake above the average dietary intake (1.52-5.20 g/d) needs to be vetted. OBJECTIVES: We aimed to determine the tolerance to graded dosages of histidine in a healthy adult population. METHODS: Healthy adults aged 21-50 y completed graded dosages of histidine supplement (4, 8, and 12 g/d, Study 1) (n = 20 men and n = 20 women) and/or a 16-g/d dosage of histidine (Study 2, n = 21 men and n = 19 women); 27 participants (n = 12 men and n = 15 women) completed both studies. After study enrollment and baseline measures, participants consumed encapsulated histidine for 4 wk followed by a 3-wk recovery period. Primary outcomes included vitals, select biochemical analytes, anthropometry, serum zinc, and body composition (via DXA). RESULTS: No changes in vitals or body composition occurred with histidine supplementation in either study. Plasma histidine (measured in subjects who completed all dosages for Studies 1 and 2) was elevated at the 12- and 16-g/d dosages (compared with 0-8 g/d, P < 0.05) and blood urea nitrogen increased with dosage (P = 0.013) and time (P < 0.001) in Study 1 and with time in Study 2 (P < 0.001). In Study 1, mean ferritin concentrations were lower in 12 g/d (46.0 ng/mL; 95% CI: 34.8, 60.9 ng/mL) than in 4 g/d (51.6 ng/mL; 95% CI: 39.0, 68.4 ng/mL; P = 0.038). In Study 2, 16 g/d increased mean aspartate aminotransferase from baseline (19 U/L; 95% CI: 17, 22 U/L) to week 4 (24 U/L; 95% CI: 21, 27 U/L; P < 0.001) and mean serum zinc decreased from baseline (0.75 µg/dL; 95% CI: 0.71, 0.80 µg/dL) to week 4 (0.70 µg/dL; 95% CI: 0.66, 0.74 µg/dL; P = 0.011). CONCLUSIONS: Although values remained within the normal reference ranges for all analytes measured, in all dosages tested, the human no-observed adverse effect level was determined to be 8 g/d owing to changes in blood parameters at the 12-g/d dosage.This trial was registered at clinicaltrials.gov as NCT04142294.


Assuntos
Histidina/farmacologia , Adulto , Glicemia/efeitos dos fármacos , Proteína C-Reativa , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Histidina/administração & dosagem , Histidina/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
J Nutr ; 139(4): 727-33, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19211833

RESUMO

We previously showed that provision of the folate recommended dietary allowance and either 300, 550, 1100, or 2200 mg/d choline for 12 wk resulted in diminished folate status and a tripling of plasma total homocysteine (tHcy) in men with the methylenetetrahydrofolate reductase (MTHFR) 677TT genotype. However, the substantial variation in tHcy within the 677TT genotype at wk 12 implied that several factors were interacting with this genotype to affect homocysteine. As an extension of this work, the present study sought to identify the main predictors of wk-12 plasma tHcy, alone and together with the MTHFR C677T genotype (29 TT, 31 CC), using linear regression analysis. A basic model explaining 82.5% of the variation (i.e. adjusted R(2) = 0.825) was constructed. However, the effects of the variables within this model were dependent upon the MTHFR C677T genotype (P for interaction < or = 0.021). Within the 677TT genotype, serum folate (P = 0.005) and plasma riboflavin (P = 0.002) were strong negative predictors (inversely related) explaining 12 and 15%, respectively, of the variation in tHcy, whereas choline intake (P = 0.003) and serum creatinine (P < 0.001) were strong positive predictors, explaining 19 and 25% of the variation. None of these variables, except creatinine (P = 0.021), correlated with tHcy within the 677CC genotype. Of the 8 additional polymorphisms tested, none appeared to influence tHcy. However, when creatinine was not in the model, the phosphatidylethanolamine N-methyltransferase 5465G-->A variant predicted lower tHcy (P < 0.001); an effect confined to the MTHFR 677TT genotype. Thus, in folate-deplete men, several factors with roles in 1-carbon metabolism interact with the MTHFR C677T genotype to affect plasma tHcy.


Assuntos
Ácido Fólico/farmacologia , Homocisteína/sangue , Metilenotetra-Hidrofolato Redutase (NADPH2)/metabolismo , Americanos Mexicanos/genética , Fosfatidiletanolamina N-Metiltransferase/metabolismo , Riboflavina/sangue , Adolescente , Adulto , Genótipo , Humanos , Masculino , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Americanos Mexicanos/etnologia , Pessoa de Meia-Idade , Mutação/genética , Fosfatidiletanolamina N-Metiltransferase/genética
18.
Am J Clin Nutr ; 109(3): 648-655, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30831597

RESUMO

BACKGROUND: Dietary choline is a precursor of trimethylamine N-oxide (TMAO), a metabolite that has been associated with an increased risk of cardiovascular disease. The mechanism underlying this association is unknown, but may include TMAO effects on blood pressure (BP). OBJECTIVES: This study assessed the association of choline intake with hypertension and BP in US adults through the use of NHANES 2007-2010 data. METHODS: This cross-sectional study was conducted in nonpregnant individuals aged ≥20 y. Choline intake was assessed with the use of two 24-h recalls. Outcomes were BP and hypertension status, which was assessed through the use of questionnaires and BP measurements. Modifying factors (e.g., sex, race/ethnicity) and dietary compared with supplemental sources of choline intake were also investigated. RESULTS: The associations of total (dietary + supplemental) and dietary choline intake with the prevalence odds of hypertension differed by sex (n = 9227; P-interaction = 0.04 and 0.03, respectively). In women, both total and dietary choline intake tended to be inversely associated with hypertension (n = 4748; prevalence OR per 100 mg of choline intake: 0.89; 95% CI: 0.77, 1.02; P < 0.10 for both total and dietary choline). No association was observed in men (n = 4479; P = 0.54 and 0.49 for total choline and dietary choline, respectively). Use of choline supplements was inversely associated with hypertension in both sexes (user compared with nonuser; OR: 0.68; 95% CI: 0.49, 0.92; P = 0.01). There was little to no association of total, dietary, or supplemental choline intake with systolic or diastolic BP (n = 6,554; the mean ± SEM change in BP associated with a 100-mg difference in total choline was -0.26 ± 0.22 mm Hg for systolic BP and -0.29 ± 0.19 mm Hg for diastolic BP). CONCLUSIONS: Cross-sectional NHANES data do not support the hypothesis of a positive association between choline intake and BP.


Assuntos
Pressão Sanguínea , Colina/metabolismo , Hipertensão/fisiopatologia , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Hipertensão/epidemiologia , Hipertensão/metabolismo , Masculino , Metilaminas/metabolismo , Pessoa de Meia-Idade , Inquéritos Nutricionais , Fatores Sexuais , Estados Unidos/epidemiologia , Adulto Jovem
19.
Endocr Connect ; 7(9): 975-982, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30300537

RESUMO

Objective: We sought to discover secreted biomarkers to monitor the recovery of physiological adiponectin levels with metabolic surgery, focusing on epigenetic changes that might predict adiponectin function. Design: We conducted a prospective observational study of patients undergoing metabolic surgery by Roux-en-Y Gastric Bypass (RYGB) for weight loss in a single center (IRB GHS # 1207-27). Methods: All patients (n = 33; 27 females; 6 males) signed informed consent. Metabolites, adiponectin and MIR148A were measured in fasting plasma. We followed MIQE for transcript profiles. Results: Patients lost on average 47 ± 12% excess BMI (%EBMI) after 12 weeks. Adiponectin pre, post or delta (post minus pre) did not correlate with %EBMIL. A decrease in adiponectin following weight loss surgery was observed in a subset of patients, chi-square test of independence rejects the null hypotheses that the liver DNA methyltransferase 1 (DNMT1) and delta adiponectin are independent (chi-square statistics χ2 = 6.9205, P = 0.00852, n = 33), as well as MIR148A and delta adiponectin are independent (chi-square statistics χ2 = 9.6823, P = 0.00186, n = 33). The presence of plasma MIR148A allows identification of patients that appear to be adiponectin insensitive at baseline. Conclusion: We combined the presence of plasma MIR148A, the concentration of total adiponectin and the expression of DNA methyltransferase 1 (DNMT1) in liver biopsy tissue to identify patients with non-physiological adiponectin. Weight loss and physical activity interventions complemented with the new method presented here could serve to monitor the physiological levels of adiponectin, thought to be important for long-term weight loss maintenance.

20.
Traffic Inj Prev ; 19(sup2): S167-S168, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30841799

RESUMO

OBJECTIVE: This study aims to identify the association, if any, between prehospital scene time, prehospital transport time, and Injury Severity Score (ISS) with in-hospital mortality. METHODS: A retrospective analysis was performed on patients at least 18 years of age who arrived to the hospital alive via emergency medical services (EMS) after a motor vehicle collision (MVC) between 1992 and 2016. These patients were divided into groups based on minutes spent at the scene and in transport. The ISS of the in-hospital mortalities, as well as the entire patient sample for each time frame, was collected. Patients without documented scene time, transport time, or ISS were excluded. RESULTS: Four thousand one hundred ninety-four patients were captured when analyzing scene time, though only 3,980 met inclusion criteria. In addition, 4,177 patients were captured when analyzing transport time, though only 3,979 met inclusion criteria. Scene time and transport time were not statistically significant predictors of in-hospital mortality (P = .31 and P = .458, respectively). ISS was found to be a statistically significant predictor of in-hospital mortality (P < .001). CONCLUSIONS: ISS predicts mortality independent of scene time or transport time for patients who arrive to the hospital alive following an MVC at Guthrie Robert Packer Hospital. Limitations of our study include inability to capture prehospital deaths and inability to correlate ISS with prehospital injury severity scores.


Assuntos
Acidentes de Trânsito/mortalidade , Serviços Médicos de Emergência/estatística & dados numéricos , Mortalidade Hospitalar , Escala de Gravidade do Ferimento , Ferimentos e Lesões/mortalidade , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Veículos Automotores , Estudos Retrospectivos , Fatores de Tempo , Ferimentos não Penetrantes/mortalidade , Ferimentos Penetrantes/mortalidade , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA