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1.
Cell ; 181(2): 306-324.e28, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32302570

RESUMO

Liquid-liquid phase separation (LLPS) mediates formation of membraneless condensates such as those associated with RNA processing, but the rules that dictate their assembly, substructure, and coexistence with other liquid-like compartments remain elusive. Here, we address the biophysical mechanism of this multiphase organization using quantitative reconstitution of cytoplasmic stress granules (SGs) with attached P-bodies in human cells. Protein-interaction networks can be viewed as interconnected complexes (nodes) of RNA-binding domains (RBDs), whose integrated RNA-binding capacity determines whether LLPS occurs upon RNA influx. Surprisingly, both RBD-RNA specificity and disordered segments of key proteins are non-essential, but modulate multiphase condensation. Instead, stoichiometry-dependent competition between protein networks for connecting nodes determines SG and P-body composition and miscibility, while competitive binding of unconnected proteins disengages networks and prevents LLPS. Inspired by patchy colloid theory, we propose a general framework by which competing networks give rise to compositionally specific and tunable condensates, while relative linkage between nodes underlies multiphase organization.


Assuntos
Grânulos Citoplasmáticos/fisiologia , Estruturas Citoplasmáticas/fisiologia , Mapas de Interação de Proteínas/fisiologia , Fenômenos Biofísicos , Linhagem Celular Tumoral , Citoplasma/metabolismo , Humanos , Proteínas Intrinsicamente Desordenadas/genética , Extração Líquido-Líquido/métodos , Organelas/química , RNA/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/fisiologia
2.
J Pharm Technol ; 34(5): 216-230, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34860982

RESUMO

Objective: Prescription drug use is on the rise, and the use of dietary supplementation remains common. In the United States, more than half of all adults take a dietary supplement in any given month. As a result, drug-nutrient interactions are becoming an important consideration when pharmacists counsel patients about their drug regimens. We reviewed the literature to identify common and/or clinically relevant drug-nutrient interactions that pharmacists may encounter in practice. Data Sources: A MEDLINE search for English-language publications from 1970 through March 2017 was performed using search terms (and variations) related to drugs, medications, micronutrients, and interactions. Study Selection and Data Extraction: Relevant studies, case reports, and reviews describing drug-nutrient interactions were selected for inclusion. Data Synthesis: Some drug-nutrient interactions may result in micronutrient insufficiencies or even frank deficiencies, thereby necessitating augmentation with multivitamin/minerals or individual vitamin/mineral dietary supplements. This most often occurs with long-term therapy for chronic conditions, such as treatment with proton-pump inhibitors and histamine-2 receptor antagonists. In addition, some chronic diseases themselves, such as diabetes, may predispose patients to micronutrient insufficiencies, and dietary supplementation may be advisable. Conclusions: Drug-nutrient interactions can often be resolved through specific dosing strategies to ensure that the full effect of the medication or the dietary supplement is not compromised by the other. In rare cases, the dietary supplement may need to be discontinued or monitored during treatment. Pharmacists are in a key position to identify and discuss these drug-nutrient interactions with patients and the health care team.

3.
Crit Rev Food Sci Nutr ; 55(14): 1968-91, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24941429

RESUMO

We reviewed recent scientific evidence regarding the effects of multivitamin/mineral (MVM) supplements on risk of chronic diseases, including cancer, cardiovascular disease, and age-related eye diseases. Data from randomized controlled trials (RCTs) and observational, prospective cohort studies were examined. The majority of scientific studies investigating the use of MVM supplements in chronic disease risk reduction reported no significant effect. However, the largest and longest RCT of MVM supplements conducted to date, the Physicians' Health Study II (PHS II), found a modest and significant reduction in total and epithelial cancer incidence in male physicians, consistent with the Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) trial. In addition, PHS II found a modest and significant reduction in the incidence of nuclear cataract, in agreement with several other RCTs and observational, prospective cohort studies. The effects of MVM use on other subtypes of cataract and age-related macular degeneration remain unclear. Neither RCTs nor prospective cohort studies are without their limitations. The placebo-controlled trial design of RCTs may be inadequate for nutrient interventions, and residual confounding, measurement error, and the possibility of reverse causality are inherent to any observational study. National surveys show that micronutrient inadequacies are widespread in the US and that dietary supplements, of which MVMs are the most common type, help fulfill micronutrient requirements in adults and children.


Assuntos
Suplementos Nutricionais/estatística & dados numéricos , Estudos Observacionais como Assunto/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Oligoelementos/uso terapêutico , Vitaminas/uso terapêutico , Envelhecimento , Doenças Cardiovasculares/prevenção & controle , Doença Crônica , Oftalmopatias/prevenção & controle , Feminino , Humanos , Masculino , Neoplasias/prevenção & controle , Estudos Prospectivos , Oligoelementos/administração & dosagem , Resultado do Tratamento , Vitaminas/administração & dosagem
4.
Adv Nutr ; 14(5): 948-958, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37270030

RESUMO

Achieving optimal health is an aspirational goal for the population, yet the definition of health remains unclear. The role of nutrition in health has evolved beyond correcting malnutrition and specific deficiencies and has begun to focus more on achieving and maintaining 'optimal' health through nutrition. As such, the Council for Responsible Nutrition held its October 2022 Science in Session conference to advance this concept. Here, we summarize and discuss the findings of their Optimizing Health through Nutrition - Opportunities and Challenges workshop, including several gaps that need to be addressed to advance progress in the field. Defining and evaluating various indices of optimal health will require overcoming these key gaps. For example, there is a strong need to develop better biomarkers of nutrient status, including more accurate markers of food intake, as well as biomarkers of optimal health that account for maintaining resilience-the ability to recover from or respond to stressors without loss to physical and cognitive performance. In addition, there is a need to identify factors that drive individualized responses to nutrition, including genotype, metabotypes, and the gut microbiome, and to realize the opportunity of precision nutrition for optimal health. This review outlines hallmarks of resilience, provides current examples of nutritional factors to optimize cognitive and performance resilience, and gives an overview of various genetic, metabolic, and microbiome determinants of individualized responses.


Assuntos
Microbioma Gastrointestinal , Ciências da Nutrição , Humanos , Estado Nutricional , Biomarcadores
5.
Mitochondrial DNA B Resour ; 6(7): 1947-1948, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34179476

RESUMO

The chocolate chip sea cucumber, Isostichopus badionotus (Selenka 1867), is an ecologically and biomedically important species. In this study, we report the complete mitogenome sequence of the sea cucumber, I. badionotus (Echinodermata: Holothuroidea). The mitochondrial genome consisted of 16,319 bp, with 13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes. The total nucleotide composition consisted of 31.61% A, 29.20% T, 23.48% C, 15.71% G, with a high A + T content of 60.81%. Phylogenetic analysis using the complete mitochondrial genome of I. badionotus is helpful in studying the evolution of beneficial adaptations to aid in bioremediation and biomedical research and development.

6.
J Obstet Gynecol Neonatal Nurs ; 48(2): 176-188, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30721652

RESUMO

OBJECTIVE: To evaluate the effect of the Premature Infant Oral Motor Intervention (PIOMI) on preterm newborns' feeding efficiency and rates of improvement across Days 1, 3, and 5 of oral feeding in a Thai NICU. DESIGN: Randomized controlled trial. SETTING: A 20-bed special neonatal ward and 8-bed NICU in urban Thailand. PARTICIPANTS: Stable newborns (N = 30) born between 26 and 34 weeks postmenstrual age (PMA) without comorbidities. METHODS: After they reached 32 to 34 weeks PMA, participants were randomly assigned to groups. The experimental group (n = 15) received the PIOMI once daily for 7 consecutive days, and the control group (n = 15) received routine care only. After oral feedings were initiated, the mean volume (MV) of oral intake of two consecutive oral feedings was calculated on Days 1, 3, and 5 to assess feeding efficiency and compare the groups. RESULTS: The MV of oral intake (percentage of prescribed feeding) was significantly greater in the experimental group versus the control group on all days of measurement. The MV consumed on Day 1 of oral feeding was 44.9% ± 7.33% in the experimental group versus 29.7% ± 9.55% in the control group (P < .001), 53.9% ± 8.01% versus 30.4% ± 11.07% on Day 3 (P < .001), and 61.7% ± 7.44% versus 34.8% ± 8.76 on Day 5 (P < .001). The rate of improvement was also accelerated in the intervention group. CONCLUSION: The improved feeding efficiency that we found in our participants is consistent with results from other published studies and supports the use of the PIOMI as an effective oral motor therapy for newborns ages 32 to 34 weeks PMA.


Assuntos
Recém-Nascido Prematuro , Destreza Motora/fisiologia , Terapia Miofuncional/métodos , Comportamento de Sucção/fisiologia , Desenvolvimento Infantil , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro/crescimento & desenvolvimento , Recém-Nascido Prematuro/fisiologia , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Masculino , Estimulação Física/métodos , Tailândia , Resultado do Tratamento , Aumento de Peso
7.
Environ Health Perspect ; 114(6): 842-7, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16759982

RESUMO

It is controversial whether trichloroethylene (TCE) is a cardiac teratogen. We exposed chick embryos to 0, 0.4, 8, or 400 ppb TCE/egg during the period of cardiac valvuloseptal morphogenesis (2-3.3 days' incubation) . Embryo survival, valvuloseptal cellularity, and cardiac hemodynamics were evaluated at times thereafter. TCE at 8 and 400 ppb/egg reduced embryo survival to day 6.25 incubation by 40-50%. At day 4.25, increased proliferation and hypercellularity were observed within the atrioventricular and outflow tract primordia after 8 and 400 ppb TCE. Doppler ultrasound revealed that the dorsal aortic and atrioventricular blood flows were reduced by 23% and 30%, respectively, after exposure to 8 ppb TCE. Equimolar trichloroacetic acid (TCA) was more potent than TCE with respect to increasing mortality and causing valvuloseptal hypercellularity. These results independently confirm that TCE disrupts cardiac development of the chick embryo and identifies valvuloseptal development as a period of sensitivity. The hypercellular valvuloseptal profile is consistent with valvuloseptal heart defects associated with TCE exposure. This is the first report that TCA is a cardioteratogen for the chick and the first report that TCE exposure depresses cardiac function. Valvuloseptal hypercellularity may narrow the cardiac orifices, which reduces blood flow through the heart, thereby compromising cardiac output and contributing to increased mortality. The altered valvuloseptal formation and reduced hemodynamics seen here are consistent with such an outcome. Notably, these effects were observed at a TCE exposure (8 ppb) that is only slightly higher than the U.S. Environmental Protection Agency maximum containment level for drinking water (5 ppb) .


Assuntos
Septos Cardíacos/efeitos dos fármacos , Hemodinâmica , Morfogênese , Tricloroetileno/farmacologia , Animais , Apoptose , Embrião de Galinha , Septos Cardíacos/embriologia , Septos Cardíacos/fisiopatologia
8.
Toxicol Sci ; 94(1): 153-62, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16917067

RESUMO

Trichloroethylene (TCE) and its metabolite trichloroacetic acid (TCA) are common drinking water contaminants in the United States. Both chemicals have been implicated in causing congenital heart defects (CHD) in human epidemiological and animal model studies. However, the latter studies have primarily focused on assessment of cardiac morphology at late embryonic stages. Here, we tested whether treating avian embryos with TCE or TCA during an exposure window encompassing cardiac specification (Hamburger-Hamilton [HH] 3+) until the onset of chambering (HH 17) informs the etiology of CHD at later stages of development. Embryos were exposed to TCE or TCA via direct injection into the yolk, over a range of doses that included each compound's maximum contaminant level as established by the U.S. Environmental Protection Agency. A modified TUNEL (Terminal deoxynucleotide transferase mediated dUTP-biotin Nick-End Labeling) assay indicated that neither compound induced apoptotic cell death in ventricular myocytes or endocardiocytes at HH 18. However, mid-range dosages of TCE increased myocyte and endocardiocyte proliferation by this time, as determined by monitoring BrdU incorporation; in contrast, an intermediate dose of TCA inhibited proliferation in endocardiocytes. These cellular changes had no apparent functional consequences because all measured hemodynamic parameters were normal for TCE- and TCA-exposed embryos at HH 18, HH 21, and HH 23. In summary, TCE or TCA exposure during the cardiac specification window has only minimal effects on the developing avian heart. These results sharply contrast with our previously reported observations following administration of equivalent doses during a window of valvuloseptal morphogenesis. Taken together, these findings indicate that, as for other teratogens, sensitivity is dictated by the embryo's stage of development.


Assuntos
Coração/efeitos dos fármacos , Coração/embriologia , Ácido Tricloroacético/toxicidade , Tricloroetileno/toxicidade , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Embrião de Galinha , Relação Dose-Resposta a Droga , Endocárdio/citologia , Endocárdio/efeitos dos fármacos , Endocárdio/embriologia , Defeitos dos Septos Cardíacos/induzido quimicamente , Defeitos dos Septos Cardíacos/embriologia , Doenças das Valvas Cardíacas/induzido quimicamente , Doenças das Valvas Cardíacas/embriologia , Ventrículos do Coração/citologia , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/embriologia , Marcação In Situ das Extremidades Cortadas , Miócitos Cardíacos/efeitos dos fármacos , Teratogênicos/toxicidade , Fatores de Tempo
9.
J Gastrointest Surg ; 10(7): 1033-7, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16843874

RESUMO

Few data exist concerning preoperative nutritional status in patients undergoing bariatric surgery. We retrospectively analyzed the preoperative values of serum albumin, calcium, 25-OH vitamin D, iron, ferritin, hemoglobin, vitamin B12, and thiamine in 379 consecutive patients (320 women and 59 men; mean body mass index 51.8 +/- 10.6 kg/m2; 25.8% white, 28.4% African American, 45.8% Hispanic) undergoing bariatric surgery between 2002 and 2004. Preoperative deficiencies were noted for iron (43.9%), ferritin (8.4%), hemoglobin (22%; women 19.1%, men 40.7%), thiamine (29%), and 25-OH vitamin D (68.1%). Low ferritin levels were more prevalent in females (9.9% vs. 0%; P = 0.01); however, anemia was more prevalent in males (19.1% vs. 40.7%; P < 0.005). Patients younger than 25 years were more likely to be anemic than patients over 60 years (46% vs. 15%; P < 0.005). This correlated with iron deficiency, which was more prevalent in younger patients (79.2% vs. 41.7%; P < 0.005). Whites (78.8%) and African Americans (70.4%) had a higher prevalence of vitamin D deficiency than Hispanics (56.4%), P = 0.01. Whites were the least likely group to be thiamine deficient (6.8% vs 31.0% African Americans and 47.2% Hispanics; P < 0.005). Nutritional deficiencies are common in patients undergoing Roux-en-Y gastric bypass, and these deficiencies should be detected and corrected early to avoid postoperative complications.


Assuntos
Derivação Gástrica , Estado Nutricional , Obesidade Mórbida/metabolismo , Obesidade Mórbida/cirurgia , Adulto , Anemia Ferropriva/diagnóstico , Deficiência de Vitaminas/diagnóstico , Cálcio/deficiência , Feminino , Ferritinas/deficiência , Hemoglobinas/deficiência , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Albumina Sérica/metabolismo , Vitaminas/metabolismo
10.
FASEB J ; 17(15): 2293-5, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14500545

RESUMO

A decline in stress tolerance is a hallmark of aging. For instance, older organisms showed extensive hepatic damage, along with increased morbidity and mortality, after environmental heating. We hypothesized that hyperthermic challenge would produce exaggerated oxidative stress in old animals, leading to increased hepatic injury. After a heat-stress protocol, time-course changes in reactive oxygen species (ROS) levels, oxidative damage markers, glutathione (GSH)/glutathione disulfide (GSSG) ratios, and activation of stress-response transcription factors (AP-1 and NF-kappaB) were measured in young and old rats. A small, transient increase in hepatic oxidative damage, with minimal injury, was observed in young rats. However, old rats showed widespread hepatic injury that was manifested over a 24 h period after heating. This pathology was preceded by elevated steady-state levels of ROS, along with large increases in lipid peroxidation products, prolonged hepatic DNA oxidation damage, aberrant GSH/GSSG profiles, and altered activation patterns for AP-1. These data indicate that young animals have an effective oxidation-reduction buffering system in the liver that provides protection from oxidative damage to intracellular macromolecules under stress conditions. In sharp contrast, an environmental challenge in older animals produces exaggerated oxidative stress and alterations in signal transduction pathways, which can contribute to cellular dysfunction and age-related reductions in stress tolerance.


Assuntos
Envelhecimento , Temperatura Alta , Hepatopatias/etiologia , Estresse Oxidativo , Fatores de Transcrição/metabolismo , Animais , DNA/metabolismo , Peroxidação de Lipídeos , Fígado/metabolismo , Hepatopatias/metabolismo , Modelos Biológicos , NF-kappa B/metabolismo , Oxirredução , Ratos , Ratos Endogâmicos F344 , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição AP-1/metabolismo
12.
Surg Obes Relat Dis ; 1(2): 73-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16925217

RESUMO

BACKGROUND: Performance of bariatric surgery in patients with human immunodeficiency virus (HIV) infection is controversial. The advent of highly active antiretroviral treatment (HAART) has dramatically reduced the progression of HIV/AIDS, so that these individuals live longer, with nearly undetectable viral loads, and thus may develop obesity and similar obesity-related comorbidity as occurs in the general population. However, HAART also causes lipodystrophy, placing these patients at increased risk for coronary artery disease. METHODS: This was a retrospective study of 6 patients from a prospectively maintained database of 892 patients (0.71%) undergoing bariatric surgery between June 1999 and December 2003. RESULTS: Six HIV-infected patients (4 women, 2 men; mean age, 43 years [range, 28-56 years]; mean preoperative weight, 142 kg [range, 110-174 kg]; mean preoperative body mass index, 50 [range, 42-59) underwent Roux-en-Y gastric bypass (RYGB). The mean duration of HIV infection was 9 years; 33% were receiving HAART at the time of surgery, which was discontinued perioperatively for 2-3 days. Average CD4 cell count was 619 cells/mm3 (range, 361-1096 cells/mm3). Preoperative comorbidities included type 2 diabetes mellitus/impaired glucose tolerance (3 cases), hypertension (2 cases), dyslipidemia (2 cases), coronary artery disease/chronic heart failure (1 case), sleep apnea (4 cases), asthma (2 cases), gastroesophageal reflux disease (3 cases), arthritis (5 cases), and depression (3 cases). Average preoperative length of hospital stay was 4.2 days (range, 3-5 days). There were no deaths or postoperative infectious complications. Mean percent excess body weight loss was 33% at 3 months, 47% at 6 months, and 61% at 12 months. Mean percent initial body weight lost was 19% at 3 months, 26% at 6 months, and 33% at 12 months. CONCLUSION: RYGB can be safely performed in HIV-infected individuals. Initial results appear to be comparable to those in noninfected controls. Well-controlled HIV infection should not be an absolute contraindication to bariatric surgery.


Assuntos
Cirurgia Bariátrica/métodos , Soropositividade para HIV , Obesidade Mórbida/cirurgia , Adulto , Anastomose em-Y de Roux , Índice de Massa Corporal , Contagem de Linfócito CD4 , Comorbidade , Feminino , Derivação Gástrica , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Redução de Peso
13.
Obes Surg ; 13(1): 23-8, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12630609

RESUMO

BACKGROUND: Inadequate protein intake is a concern following Roux-en-Y gastric bypass (RYGBP). The small gastric pouch and bypass restrict energy intake and may lead to insufficient protein intake and absorption, and excess loss of lean tissue. METHODS: We evaluated protein intake in 93 (77 F, 16 M) morbidly obese individuals (BMI = 52.0 +/- 12.9 [SD]) who underwent RYGBP at our medical center. Participants completed 24-hr food recalls and received nutritional counseling at 3, 6, and 12 months following surgery. RESULTS: Daily energy intake (kcal/day) increased from 849 +/- 329 (SD) at 3 months to 1,101 +/- 400 at 12 months (P = .009). Protein intake also increased (g/day) from 45.6 +/- 14.2 at 3 months to 58.5 +/- 17.1 at 12 months (P = .04), and as a percentage of goal protein intake from 55.1% +/- 23.0 at 3 months to 73.5% +/- 38.0 at 12 months (P = .02). Although energy and protein intake increased significantly over the 12-month period, protein intake at 12 months remained significantly lower (P = .01) than the daily recommended guidelines (1.5 g/kg IBW) for a low-energy restrictive diet. Energy intake did not differ in those who reported food intolerances at 3 months (P = .77) or 6 months (P = .65), but was lower in them at 12 months (trend, P = .06). Also at 12 months, protein intake (P = .02) and percentage of protein intake goal (P = .04) were significantly lower in those with protein intolerance. CONCLUSIONS: These results suggest that postoperative patients consume insufficient amounts of protein, possibly mediated by protein intolerance. Protein supplementation following RYGBP deserves further consideration.


Assuntos
Proteínas Alimentares/administração & dosagem , Derivação Gástrica , Obesidade Mórbida/metabolismo , Adulto , Ingestão de Energia , Humanos , Pessoa de Meia-Idade , Avaliação Nutricional , Período Pós-Operatório
14.
J Appl Physiol (1985) ; 92(4): 1762-9; discussion 1749, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11896047

RESUMO

Aging is associated with a reduced capacity to cope with physiological stress. To study the molecular mechanisms associated with the decline in stress tolerance that accompanies aging, differences in gene expression between young and old Fischer 344 rats under euthermic control conditions or in response to hyperthermic challenge were evaluated using a cDNA array containing 207 stress-related genes. In the nonstressed control condition, aging resulted in selective upregulation of stress protein genes and transcripts involved in cell growth, death, and signaling, along with a downregulation of genes involved in antioxidant defenses and drug metabolism. Heat stress resulted in a broad induction of genes in the antioxidant and drug metabolism categories and transcripts involved in DNA, RNA, and protein synthesis for both age groups. Old animals had a robust upregulation of genes involved in cell growth, death, and signaling after heat challenge, along with a blunted expression of stress-response genes. In contrast, young animals had a strong induction of stress-response genes after hyperthermic challenge. Changes in expression of selected genes were confirmed by RT-PCR analysis. These findings suggest that aging results in altered gene expression in response to heat stress that is indicative of decreased stress protein transcription and increased expression of oxidative stress-related genes. Thus our findings support the postulate that transcriptional changes in response to a physiological challenge such as hyperthermia contribute to the loss of stress tolerance in older organisms.


Assuntos
Envelhecimento/metabolismo , Febre/genética , Febre/fisiopatologia , Transtornos de Estresse por Calor/genética , Transtornos de Estresse por Calor/fisiopatologia , Animais , Antioxidantes/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica/fisiologia , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Ratos , Ratos Endogâmicos F344 , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas
16.
Toxicol Sci ; 113(2): 444-52, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19910388

RESUMO

Trichloroethylene (TCE) is the most frequently reported organic groundwater contaminant in the United States. It is controversial whether gestational TCE exposure causes congenital heart defects. The basis for TCE's proposed cardiac teratogenicity is not well understood. We previously showed that chick embryos exposed to 8 ppb TCE during cardiac morphogenesis have reduced cardiac output and increased mortality. To further investigate TCE's cardioteratogenic potential, we exposed in ovo chick embryos to TCE and evaluated the heart thereafter. Significant mortality was observed following TCE exposures of 8-400 ppb during a narrow developmental period (Hamburger-Hamilton [HH] stages 15-20, embryo day ED2.3-3.5) that is characterized by myocardial expansion, secondary heart looping, and endocardial cushion formation. Of the embryos that died, most did so between ED5.5 and ED6.5. Echocardiography of embryos at ED5.5 found that TCE-exposed hearts displayed significant functional and morphological heterogeneity affecting heart rate, left ventricular mass, and wall thickness. Individual embryos were identified with cardiac hypertrophy as well as with hypoplasia. Chick embryos exposed to 8 ppb TCE at HH17 that survived to hatch exhibited a high incidence (38%, p < 0.01, n = 16) of muscular ventricular septal defects (VSDs) as detected by echocardiography and confirmed by gross dissection; no VSDs were found in controls (n = 14). The TCE-induced VSDs may be secondary to functional impairments that alter cardiac hemodynamics and subsequent ventricular foramen closure, an interpretation consistent with recent demonstrations that TCE impairs calcium handling in cardiomyocytes. These data demonstrate that TCE is a cardiac teratogen for chick.


Assuntos
Poluentes Ambientais/toxicidade , Comunicação Interventricular/induzido quimicamente , Coração/efeitos dos fármacos , Tricloroetileno/toxicidade , Animais , Embrião de Galinha , Coração/embriologia , Comunicação Interventricular/embriologia , Comunicação Interventricular/patologia , Testes de Toxicidade
17.
Birth Defects Res A Clin Mol Teratol ; 76(1): 66-71, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16333841

RESUMO

BACKGROUND: Teratology studies must be carefully designed to minimize potential secondary effects of vehicle and delivery routes. A systematic method to evaluate chick models of early embryogenesis is lacking. METHODS: We investigated 3 experimental approaches that are popular for studies of early avian development, in terms of their utility for teratogen assessment starting at gastrulation. These included in vitro embryo culture, egg windowing followed by direct application of a carrier vehicle to the embryo, and injection of a carrier vehicle into the egg yolk. We also developed a morphologically based scoring system to assess development of the early embryo. RESULTS: The in vitro culture and egg windowing approaches both caused an unacceptably high incidence of central nervous system and cardiac abnormalities in vehicle-treated embryos, which made it difficult to identify teratogen-specific defects. In contrast, exposing chick embryos to vehicle via direct egg yolk injection did not induce developmental anomalies. CONCLUSIONS: Optimization of the exposure route of potential toxicants to the embryo is critical because control treatments can cause developmental anomalies. In ovo yolk injection minimizes perturbation of young embryos and may be appropriate for teratogen delivery.


Assuntos
Embrião de Galinha/anormalidades , Embrião de Galinha/efeitos dos fármacos , Gástrula , Teratogênicos/toxicidade , Teratologia/métodos , Animais , Avaliação Pré-Clínica de Medicamentos/métodos , Modelos Biológicos
18.
J Virol ; 76(1): 355-63, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11739700

RESUMO

Adenovirus gene therapy is a promising tool in the clinical treatment of many genetic and acquired diseases. However, it has also caused pathogenic effects in organs such as the liver. The redox-sensitive transcription factors AP-1 and NF-kappaB have been implicated in these effects. To study the mechanisms of adenovirus-mediated AP-1 and NF-kappaB activation and the possible involvement of oxidative stress in adenovirus transduction, rats were injected with either replication-defective recombinant adenovirus with DNA containing the cytomegalovirus promoter region only (AdCMV), adenovirus containing human manganese-containing superoxide dismutase (MnSOD) cDNA (AdMnSOD), or vehicle. Compared to vehicle and AdCMV transduction, MnSOD gene transfer yielded a fivefold increase in liver MnSOD activity 7 days postinjection. Gel shift assay showed that AdCMV transduction induced DNA binding activity for AP-1 but not NF-kappaB. MnSOD overexpression abolished this activation. Western blotting analysis of c-Fos and c-Jun suggested that up-regulation of c-fos and c-jun gene expression does not directly contribute to the induction of AP-1 activation. Glutathione/glutathione disulfide ratios were decreased by adenovirus transduction and restored by MnSOD overexpression. The AP-1 binding activity that was induced by AdCMV was decreased by immunoprecipitation of Ref-1 protein. Ref-1 involvement was confirmed by restoration of AP-1 binding activity after the immunoprecipitated Ref-1 protein had been added back. AP-1 DNA binding activity was also elevated in control and AdMnSOD-injected rats after addition of the immunoprecipitated Ref-1 protein. These data indicate that cellular transduction by recombinant adenovirus stimulates AP-1 DNA binding activity. Furthermore, our results suggest that MnSOD overexpression decreases AP-1 DNA binding activity by regulating intracellular redox status, with the possible involvement of Ref-1 in this redox-sensitive pathway.


Assuntos
Adenoviridae/metabolismo , DNA Liase (Sítios Apurínicos ou Apirimidínicos) , Superóxido Dismutase/metabolismo , Fator de Transcrição AP-1/metabolismo , Adenoviridae/genética , Animais , Carbono-Oxigênio Liases/metabolismo , Proteínas de Ligação a DNA/metabolismo , Vetores Genéticos , Fígado/metabolismo , Masculino , Oxirredução , Ratos , Ratos Endogâmicos F344 , Recombinação Genética , Superóxido Dismutase/análise
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