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1.
PLoS One ; 19(4): e0292198, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38574116

RESUMO

The surgical sterilization of cats and dogs has been used to prevent their unwanted breeding for decades. However, this is an expensive and invasive procedure, and often impractical in wider contexts, for example the control of feral populations. A sterilization agent that could be administered in a single injection, would not only eliminate the risks imposed by surgery but also be a much more cost-effective solution to this worldwide problem. In this study, we sought to develop a targeting peptide that would selectively bind to Leydig cells of the testes. Subsequently, after covalently attaching a cell ablation agent, Auristatin, to this peptide we aimed to apply this conjugated product (LH2Auristatin) to adult male mice in vivo, both alone and together with a previously developed Sertoli cell targeting peptide (FSH2Menadione). The application of LH2Auristatin alone resulted in an increase in sperm DNA damage, reduced mean testes weights and mean seminiferous tubule size, along with extensive germ cell apoptosis and a reduction in litter sizes. Together with FSH2Menadione there was also an increase in embryo resorptions. These promising results were observed in around a third of all treated animals. Given this variability, we discuss how these reagents might be modified in order to increase target cell ablation and improve their efficacy as sterilization agents.


Assuntos
Células Intersticiais do Testículo , Testículo , Masculino , Camundongos , Animais , Gatos , Cães , Espermatogênese , Sêmen , Células de Sertoli/metabolismo , Peptídeos/metabolismo
2.
Sci Rep ; 12(1): 20847, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36522361

RESUMO

Long-duration spaceflight impacts human physiology, including well documented immune system dysregulation. The space food system has the potential to serve as a countermeasure to maladaptive physiological changes during spaceflight. However, the relationship between dietary requirements, the food system, and spaceflight adaptation requires further investigation to adequately define countermeasures and prioritize resources on future spaceflight missions. We evaluated the impact of an enhanced spaceflight diet, with increased quantity and variety of fruits, vegetables, fish, and other foods rich in flavonoids and omega-3 fatty acids, compared to a standard spaceflight diet on multiple health and performance outcomes in 16 subjects over four 45-day closed chamber missions in the NASA Human Exploration Research Analog (HERA). Subjects consuming the enhanced spaceflight diet had lower cholesterol levels, lower stress (i.e. cortisol levels), better cognitive speed, accuracy, and attention, and a more stable microbiome and metatranscriptome than subjects consuming the standard diet. Although no substantial changes were observed in the immune response, there were also no immune challenges, such as illness or infection, so the full benefits of the diet may not have been apparent in these analog missions. These results indicate that a spaceflight diet rich in fruits, vegetables, and omega-3 fatty acids produces significant health and performance benefits even over short durations. Further investigation is required to fully develop dietary countermeasures to physiological decrements observed during spaceflight. These results will have implications for food resource prioritization on spaceflight missions.


Assuntos
Ácidos Graxos Ômega-3 , Microbioma Gastrointestinal , Voo Espacial , Animais , Humanos , Dieta , Cognição , Imunidade
3.
Life Sci Space Res (Amst) ; 30: 72-81, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34281667

RESUMO

Long-duration space exploration missions will pose significant risks to the physical and behavioral health and performance of the crew. We documented the presence and frequency of (1) behavioral health and performance (BHP)-relevant symptoms for each condition in NASA's Exploration Medical Conditions List (EMCL), (2) the BHP-relevant effects of applicable medical treatments in the current International Space Station (ISS) On-Orbit Medication List, (3) the breadth of potential BHP impacts of spaceflight medical treatments, and (4) the likelihood of adverse BHP effects of treating spaceflight medical conditions. BHP symptoms and effects were categorized by the six neurobehavioral domains of the National Institute of Mental Health's Research Domain Criteria (RDoC) framework. Including the cognitive effects of acute and chronic pain (e.g., attention, memory), 94% of spaceflight medical conditions include symptoms relevant to Cognitive Systems (e.g., attention deficits, confusion, psychosis), 36% include symptoms relevant to Negative Valence Systems (e.g., anxiety), 32% include symptoms relevant to Arousal and Regulatory Systems (e.g., sleep disturbances), 22% include symptoms relevant to Sensorimotor Systems (e.g., dizziness), 19% include symptoms relevant to Positive Valence Systems (e.g., mania), and 11% include symptoms relevant to Social Processes (e.g., social withdrawal). Only 2% of spaceflight medical conditions have no documented BHP symptoms. Of the spaceflight medical treatments, 63% affect Arousal and Regulatory Systems, 60% affect Sensorimotor Systems, 59% affect Cognitive Systems, 53% affect Negative Valence Systems, 38% affect Positive Valence Systems, and 31% affect Social Processes. The breadth of potential BHP impacts was bimodal, in that 27% of spaceflight medical treatments had no documented BHP effects; however, 27% of treatments may produce adverse effects across all six neurobehavioral domains. Historical prevalence data on medical conditions, symptoms, and complaints from 14 years of International Space Station operations coupled with documented BHP effects of recommended treatments indicates the potential for up to 481 adverse BHP effects of spaceflight medical treatments per person-year. Assessing the potential BHP impacts of spaceflight medical conditions and their treatments highlights the interactive nature of operational risks, and can provide an enhanced evidence base to support integrated research and countermeasure development strategies for long-duration exploration missions.


Assuntos
Astronautas , Voo Espacial , Humanos , Fatores de Tempo
4.
Mol Cell Endocrinol ; 526: 111193, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33610643

RESUMO

Evidence is presented for expression of the insulin receptor on the surface of mammalian spermatozoa as well as transcripts for the receptor substrate adaptor proteins (IRS1-4) needed to mediate insulin action. Exposure to this hormone resulted in insulin receptor phosphorylation (pTyr972), activation of AKT (pSer473) and the stimulation of sperm motility. Intriguingly, the male germ line is also shown to be capable of generating insulin, possessing the relevant mRNA transcript and expressing strong immunocytochemical signals for both insulin and C-peptide. Insulin could be released from the spermatozoa by sonication in a concentration-dependent manner but was not secreted in response to glucose, fructose or stimulation with progesterone. However, insulin release could be induced by factors present in human uterine lavages. Furthermore, the endometrium was also shown to possess the machinery for insulin production and action (mRNA, insulin, C-peptide, proprotein convertase and insulin receptor), releasing insulin into the uterine lumen prior to ovulation. These studies emphasize the fundamental importance of extra-pancreatic insulin in regulating the reproductive process, particularly in the support of spermatozoa on their perilous voyage to the site of fertilization.


Assuntos
Insulina/biossíntese , Pâncreas/metabolismo , Espermatozoides/citologia , Espermatozoides/metabolismo , Animais , Peptídeo C/metabolismo , Sobrevivência Celular , Endométrio/metabolismo , Epitélio/metabolismo , Feminino , Células Germinativas/metabolismo , Humanos , Proteínas Substratos do Receptor de Insulina/metabolismo , Secreção de Insulina , Masculino , Mamíferos/metabolismo , Camundongos , Isoformas de Proteínas/metabolismo , Ratos , Receptor de Insulina/metabolismo , Útero/metabolismo
5.
Free Radic Biol Med ; 164: 410-416, 2021 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-33482333

RESUMO

Oxidative stress generates a large amount of reactive oxygen species (ROS) and affects sperm quality via damaging sperm DNA and compromising the intracellular homeostasis in human spermatozoa. In assisted reproductive technology (ART), it is substantial to prevent spermatozoa from ROS attack. The pineal hormone melatonin has the natural antioxidant capacity and can scavenge ROS. To the best of our knowledge, however, there are presently no studies investigating if melatonin can protect human spermatozoa from heat-induced oxidative damage. Herein, we induced oxidative stress in human spermatozoa with heat treatment, and determined that melatonin could protect human spermatozoa from heat-induced oxidative stress. We first confirmed that heat stress-induced oxidative stress damaged human spermatozoa by decreasing sperm motility and viability. Furthermore, the pretreatment of human spermatozoa by melatonin was able to alleviate such damage by suppressing sperm mitochondrial ROS generation, increasing mitochondrial membrane potential, reducing the formation of the lipid peroxidation product, 4-HNE, and reducing sperm DNA damage and apoptosis. Collectively, these findings suggest that melatonin is useful as a potential treatment option for male infertility caused by heat-induced oxidative stress.


Assuntos
Melatonina , Apoptose , Resposta ao Choque Térmico , Humanos , Peroxidação de Lipídeos , Masculino , Melatonina/metabolismo , Melatonina/farmacologia , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Motilidade dos Espermatozoides , Espermatozoides/metabolismo
6.
Mutat Res ; 821: 111722, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32920458

RESUMO

DNA damage is a common feature of human spermatozoa associated with an impaired capacity to fertilize the oocyte and an increased mutational load in the offspring. However, the etiology of this damage remains poorly defined. In this study we demonstrate that a major pathway for the induction of DNA damage in mammalian spermatozoa is triggered by exposure to exogenous cell free DNA (cfDNA). Exposure of human and mouse spermatozoa to cfDNA (calf thymus, mouse liver and salmon testes) in vitro induced a dose-dependent increase in sperm DNA damage that could be effectively suppressed by the concomitant presence of DNase. The induction of such damage was not accompanied by any concomitant change in sperm motility or vitality and was not directly associated with the induction of oxidative stress. In vivo the injection of exogenous DNA again precipitated an increase in sperm DNA fragmentation that could be reversed by the prior administration of DNase. Similarly, the induction of a transient unilateral testicular ischemia induced an increase in DNA fragmentation that was evident within 24 h and sustained for at least 14 days via mechanisms that could be completely suppressed by the prior administration of DNase. We conclude that exogenous cfDNA activates a defensive response in human spermatozoa associated with the nuclease-mediated induction of DNA fragmentation, possibly involving the participation of TLR9 and CD4. These novel insights have significant implications for our understanding of DNA fragmentation in the male germ line and open up new pathways for the remediation of this condition.


Assuntos
Ácidos Nucleicos Livres/farmacologia , Dano ao DNA , Fertilidade/efeitos dos fármacos , Estresse Oxidativo , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/patologia , Animais , Feminino , Humanos , Masculino , Camundongos , Espermatozoides/efeitos dos fármacos
7.
Reproduction ; 158(2): 169-179, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31226694

RESUMO

Male fertility and sperm quality are negatively impacted by obesity. Furthermore, recent evidence has shown that male offspring from obese rat mothers also have reduced sperm quality and fertility. Here, we extend work in this area by comparing the effects of both maternal obesity and offspring post-weaning diet-induced obesity, as well as their combination, on sperm quality in mice. We additionally tested whether administration of the NAD+-booster nicotinamide mononucleotide (NMN) can ameliorate the negative effects of obesity and maternal obesity on sperm quality. We previously showed that intraperitoneal (i.p.) injection of NMN can reduce the metabolic deficits induced by maternal obesity or post-weaning dietary obesity in mice. In this study, female mice were fed a high-fat diet (HFD) for 6 weeks until they were 18% heavier than a control diet group. Thereafter, HFD and control female mice were mated with control diet males, and male offspring were weaned into groups receiving control or HFD. At 30 weeks of age, mice received 500 mg/kg body weight NMN or vehicle PBS i.p. for 21 days. As expected, adiposity was increased by both maternal and post-weaning HFD but reduced by NMN supplementation. Post-weaning HFD reduced sperm count and motility, while maternal HFD increased offspring sperm DNA fragmentation and levels of aberrant sperm chromatin. There was no evidence that the combination of post-weaning and maternal HFD exacerbated the impacts in sperm quality suggesting that they impact spermatogenesis through different mechanisms. Surprisingly NMN reduced sperm count, vitality and increased sperm oxidative DNA damage, which was associated with increased NAD+ in testes. A subsequent experiment using oral NMN at 400 mg/kg body weight was not associated with reduced sperm viability, oxidative stress, mitochondrial dysfunction or increased NAD+ in testes, suggesting that the negative impacts on sperm could be dependent on dose or mode of administration.


Assuntos
Infertilidade Masculina/etiologia , Mononucleotídeo de Nicotinamida/farmacologia , Obesidade Materna , Efeitos Tardios da Exposição Pré-Natal , Espermatozoides/efeitos dos fármacos , Animais , Feminino , Masculino , Camundongos Endogâmicos C57BL , Gravidez
8.
Clin Neuropsychol ; 33(5): 890-904, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30698067

RESUMO

Objective: Complete prenatal cerebellar infarction is rare and few reports exist documenting developmental outcomes. We report outcome data on a child who sustained a stroke to the bilateral cerebellar hemispheres at 25 weeks gestation, and was subsequently seen for follow-up neuropsychological evaluations at ages 5 years, 5 months and 7 years, 9 months. Method: Retrospective chart review. Results: Findings from the initial evaluation at age 5 were consistent with a diagnosis of intellectual disability based on developmental testing and parent-reported adaptive behavior. Deficits in social communication, relatedness, and reciprocity were identified, though diagnosis of an autism-spectrum disorder (ASD) was deferred given the difficulty of interpreting these findings in the context of his physical and cognitive disabilities. Re-assessment at age 7 included comprehensive autism assessment, and a diagnosis of ASD was confirmed. Neuropsychological testing revealed minimal developmental skill progression over the assessment interval. Conclusions: These findings add to growing evidence that the cerebellum plays an important role in social development, and that early cerebellar injury may represent an acquired pathway for ASD. Complex medical histories may obscure or delay diagnosis of ASD, highlighting the importance of early evaluation using a multidisciplinary approach.


Assuntos
Infarto Encefálico/complicações , Encéfalo/patologia , Testes Neuropsicológicos/normas , Comportamento Social , Criança , Pré-Escolar , Humanos , Masculino , Estudos Retrospectivos
9.
Sci Total Environ ; 607-608: 829-837, 2017 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-28711844

RESUMO

Insecticide indoxacarb metabolites JT333 and MP819 were used as model compounds to assess the utilization of kinetic modeling to elucidate metabolic pathways, determine degradation kinetics of non-extractable residues (NER) and predict the accumulation potential of the released NER in soil. Soil adsorption coefficients and degradation product formation were determined in different soils in laboratory. Inverse kinetic modeling was applied to explore the dynamics of dissipation of parent (P), formation of extractable metabolites (MET), NER and CO2, and to identify their routes of degradation in soil. These two compounds share similar structural characteristics, have high affinity to soil (Koc>5000L/kg), short half-life (DT50 of 4-9days), and significant CO2 formation in soil. However, kinetic modeling showed that they degraded via different pathways. The P-MET-CO2 conversion route was the major degradation pathway for JT333 in aerobic soil. Multiple pathways were involved in MP819 degradation, while the formation of NER was predominant. The time-exposure area under the curves (AUC) for the MET or NER in soils were derived from the time-%concentration plots for the evaluation of rate limiting steps in their degradation pathways. In P-MET-CO2 pathway the MET-CO2 conversion is the rate limiting step for both compounds. Higher P-MET conversion/MET-CO2 conversion rate constant ratio resulted in larger MET AUC. The rate of NER degradation appeared much slower compared to the rates of P-MET and MET-CO2 conversions, likely due to the rate-limiting step of NER release from the bound-state, indicating that in this situation the free-state NER would be unlikely to accumulate in soil. The study reported here demonstrates the utility of kinetic modeling to quantify the dynamics of NER formation/dissipation vs. P-MET-CO2 conversion, and the application of kinetic modeling to predict the possibility of free-sate NER accumulation in soil, therefore, reveals the potential for the quantitative NER environmental risk assessment.


Assuntos
Oxazinas/química , Poluentes do Solo/química , Solo/química , Cinética , Modelos Químicos
10.
Fam Syst Health ; 34(2): 166-71, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26963775

RESUMO

INTRODUCTION: Caring for children with oncological and hematological disorders may lead to caregiver emotional distress and caregiver burden; however, little work has examined the relationship between children's symptoms and caregiver's distress and burden. METHOD: This study used self-report survey data from caregivers (N = 96) and a cross-sectional design to examine correlates of caregiver emotional distress and burden. Data collected included caregiver and child demographic data, child symptoms (i.e., sleep problems, pain, and emotional/behavioral problems), caregiver emotional distress, and caregiver burden. RESULTS: Multiple linear regression found that parent reported financial difficulty (ß = 0.29, t = 3.13, p = .003), greater child sleep problems (ß = 0.29 t = 2.81, p = .007), greater child pain (ß = 0.33 t = 3.48, p = .001), and greater child emotional/behavioral problems (ß = 0.27, t = 2.71, p = .009) were all related to higher levels of caregiver emotional distress. Only financial difficulties (ß = -0.35, t = -2.03, p = .04) and child pain (ß = -0.30, t = -2.33, p = .02) were related to caregiver burden. DISCUSSION: Child symptoms may play an important role in the development of caregiver distress and caregiver burden; future research should utilize longitudinal designs to examine temporal and casual relationships. (PsycINFO Database Record


Assuntos
Adaptação Psicológica , Cuidadores/psicologia , Saúde da Criança , Estresse Psicológico/etiologia , Adolescente , Adulto , Criança , Pré-Escolar , Efeitos Psicossociais da Doença , Estudos Transversais , Feminino , Doenças Hematológicas/psicologia , Doenças Hematológicas/terapia , Humanos , Lactente , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Neoplasias/psicologia , Neoplasias/terapia , Relações Pais-Filho , Pais/psicologia , Estresse Psicológico/psicologia , Inquéritos e Questionários
11.
Mol Hum Reprod ; 21(6): 502-15, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25837702

RESUMO

Oxidative stress is known to compromise human sperm function and to activate the intrinsic apoptotic cascade in these cells. One of the key features of oxidatively stressed spermatozoa is the induction of a lipid peroxidation process that results in the formation of aldehydes potentially capable of disrupting sperm function through the formation of adducts with DNA and key proteins. In this study, we have examined the impact of a range of small molecular mass aldehydes generated as a consequence of lipid peroxidation on human sperm function and also compared the two most commonly formed compounds, 4-hydroxynonenal (4HNE) and malondialdehyde (MDA), for their relative ability to reflect a state of oxidative stress in these cells. Dramatic differences in the bioactivity of individual aldehydes were observed, that generally correlated with the second order rate constants describing their interaction with the model nucleophile, glutathione. Our results demonstrate that acrolein and 4HNE were the most reactive lipid aldehydes, inhibiting sperm motility while augmenting reactive oxygen species production, lipid peroxidation, oxidative DNA damage and caspase activation, in a dose-dependent manner (P < 0.001). In contrast, a variety of saturated aldehydes and the well-known marker of oxidative stress, MDA, were without effect on this cell type. While MDA was not cytotoxic per se, its generation did reflect the induction of oxidative stress in vivo and in vitro in a manner that was highly correlated with the bioactive lipid aldehyde, 4HNE. Despite such overall correlations, individual patient samples were observed in which either MDA or 4HNE predominated. Given the relative cytotoxicity of 4HNE, we propose that this aldehyde should be the preferred criterion for diagnosing oxidative stress in the male germ line.


Assuntos
Peroxidação de Lipídeos , Estresse Oxidativo , Espermatozoides/metabolismo , Aldeídos/metabolismo , Apoptose , Dano ao DNA , Humanos , Masculino , Malondialdeído/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Motilidade dos Espermatozoides , Espermatozoides/fisiologia
12.
Free Radic Biol Med ; 81: 69-76, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25640728

RESUMO

Human spermatozoa are compromised by production of reactive oxygen species (ROS), and detection of ROS in spermatozoa is important for the diagnosis of male infertility. The probes 2',7'-dichlorohydrofluorescein diacetate (DCFH), dihydroethidium (DHE), and MitoSOX red (MSR) are commonly used for detecting ROS by flow cytometry; however, these probes lack sensitivity to hydrogen peroxide (H2O2), which is particularly damaging to mammalian sperm cells. This study reports the synthesis and use of three aryl boronate probes, peroxyfluor-1 (PF1), carboxyperoxyfluor-1, and a novel probe, 2-(2-ethoxyethoxy)ethoxyperoxyfluor-1 (EEPF1), in human spermatozoa. PF1 and EEPF1 were effective at detecting H2O2 and peroxynitrite (ONOO(-)) produced by spermatozoa when stimulated with menadione or 4-hydroxynonenal. EEPF1 was more effective at detection of ROS in spermatozoa than DCFH, DHE, or MSR; furthermore it distinguished poorly motile sperm as shown by greater ROS production. EEPF1 should therefore have a significant role in the diagnosis of oxidative stress in male infertility, cryopreservation, age, lifestyle, and exposure to environmental toxicants.


Assuntos
Ácidos Borônicos/química , Fluoresceínas/química , Corantes Fluorescentes/química , Sondas Moleculares/química , Espermatozoides/efeitos dos fármacos , Aldeídos/farmacologia , Ácidos Borônicos/síntese química , Células Cultivadas , Etídio/análogos & derivados , Etídio/química , Fluoresceínas/síntese química , Corantes Fluorescentes/síntese química , Humanos , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/metabolismo , Masculino , Sondas Moleculares/síntese química , Compostos Organofosforados/química , Ácido Peroxinitroso/análise , Ácido Peroxinitroso/metabolismo , Fenantridinas/química , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/citologia , Espermatozoides/metabolismo , Vitamina K 3/farmacologia
13.
Arch Environ Contam Toxicol ; 68(4): 745-56, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25608617

RESUMO

A method was developed for the extraction and analysis of 2 organophosphate, 8 pyrethroid, and 5 neonicotinoid insecticides from the same water sample. A salted liquid-liquid extraction (LLE) was optimized with a solid-phase extraction (SPE) step that separated the organophosphates (OPs) and pyrethroids from the neonicotinoids. Factors that were optimized included volume of solvent and amount of salt used in the LLE, homogenization time for the LLE, and type and volume of eluting solvent used for the SPE. The OPs and pyrethroids were quantified using gas chromatography-mass spectrometry, and the neonicotinoids were quantified using liquid chromatography-diode array detector. Results showed that the optimized method was accurate, precise, reproducible, and robust; recoveries in river water spiked with 100 ng L(-1) of each of the insecticides were all between 86 and 114 % with RSDs between 2 and 8 %. The method was also sensitive with method detection limits ranging from 0.1 to 27.2 ng L(-1) depending on compounds and matrices. The optimized method was thus appropriate for the simultaneous extraction of 15 widely applied insecticides from three different classes and was shown to provide valuable information on their environmental fate from field-collected aqueous samples.


Assuntos
Inseticidas/análise , Organofosfatos/análise , Piretrinas/análise , Extração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , Cromatografia Líquida , Água Doce/química , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção
14.
Integr Environ Assess Manag ; 11(3): 445-58, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25557061

RESUMO

A site-specific ecological risk assessment (ERA) was conducted to examine the simultaneous use of genetically modified corn (Bt corn) with a neonicotinoid seed coating, clothianidin, and use of a granular insecticide, tefluthrin, to protect crops from pest damage. A field study was conducted on site, and exposure data from the literature were summarized to determine the matrices and exposure concentrations that nontarget species could typically experience within an agricultural ecosystem. To determine ecological effects on nontarget species, acute toxicity bioassays were conducted on earthworms (Eisenia fetida), amphipods (Hyalella azteca), and Elmid riffle beetle larvae (Ancyronyx spp.) in which the test species were exposed to single insecticides as well as the mixture of the 3 insecticides. In the risk characterization section of the ERA, stressor-response profiles for each species tested were compared with field distributions of the insecticides, and a margin of safety at the 10th percentile (MOS10) was calculated to estimate risk. No acute toxicity was observed in any of the 3 nontarget species after exposure to senescent Bt corn leaf tissue. Large MOS10 values were calculated for clothianidin to the nontarget species. When bioassays were compared with tefluthrin field distributions, very low MOS10 values were calculated for earthworms (0.06) and H. azteca (0.08) because the environmental concentrations often exceeded the stressor-response profile. No increased toxicity was observed when nontarget species were exposed to a mixture of the 3 insecticides. In summary, the genetically modified corn insecticidal proteins and clothianidin were not found at environmental concentrations exceeding benchmark values for ecological effects, but tefluthrin was consistently detected in the environment at levels that could be causing toxicity to nontarget species, especially if this pyrethroid is able to travel off site.


Assuntos
Agricultura , Monitoramento Ambiental , Poluentes Ambientais/toxicidade , Inseticidas/toxicidade , Zea mays/crescimento & desenvolvimento , Anfípodes , Animais , Besouros , Produtos Agrícolas/crescimento & desenvolvimento , Ecossistema , Poluentes Ambientais/análise , Inseticidas/análise , Oligoquetos , Medição de Risco
15.
Arch Environ Contam Toxicol ; 68(2): 354-61, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25298152

RESUMO

Two species, the fathead minnow Pimephales promelas and the amphipod Hyalella azteca, were tested to examine acute toxicity to two insecticides, cyfluthrin and imidacloprid individually and as a mixture. Cyfluthrin was acutely toxic to P. promelas and H. azteca with EC50 values and 95 % confidence intervals of 0.31 µg L(-1) (0.26-0.35 µg L(-1)) and 0.0015 µg L(-1) (0.0011-0.0018 µg L(-1)), respectively. Imidacloprid was not acutely toxic to P. promelas at water concentrations ranging from 1 to 5000 µg L(-1), whereas it was toxic to H. azteca with a EC50 value of 33.5 µg L(-1) (23.3-47.4 µg L(-1)). For the P. promelas mixture test, imidacloprid was added at a single concentration to a geometric series of cyfluthrin concentrations bracketing the EC50 value. A synergistic ratio (SR) of 1.9 was found for P. promelas, which was calculated using the cyfluthrin-only exposure and mixture-exposure data. Because cyfluthrin and imidacloprid were toxic to H. azteca, the mixture test was designed based on an equipotent toxic unit method. Results from the mixture test indicated a model deviation ratio (MDR) of 1.7 or 2.7 depending on the model. Mixture test results from the simultaneous exposure to cyfluthrin and imidacloprid with both species indicated a greater than expected toxic response because the SR or MDR values were >1. Because these two insecticides are commonly used together in the same product formulations, nontarget species could be more affected due to their greater-than-additive toxicity observed in the current study.


Assuntos
Imidazóis/toxicidade , Inseticidas/toxicidade , Nitrilas/toxicidade , Nitrocompostos/toxicidade , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Anfípodes , Animais , Cyprinidae , Dose Letal Mediana , Neonicotinoides , Testes de Toxicidade Aguda
16.
Sci Total Environ ; 497-498: 534-542, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25163650

RESUMO

A mixture of insecticides used in corn production was monitored over a three-year period in a field study to determine how long each persists in the environment, where each insecticide travels within the corn field, and the efficacy of using soil-applied insecticides with genetically modified corn. The genetically modified corn contained the insecticidal Cry1Ab and Cry3Bb1 proteins (Bt corn) and the Cry1Ab protein was found to persist only during the corn growing season in soil, runoff water, and runoff sediment with highest concentrations measured during pollination. Very low concentrations of Cry1Ab proteins were measured in soil collected in the non-Bt corn field, and no Cry1Ab proteins were detected in shallow groundwater or soil pore water. Clothianidin, a neonicotinoid insecticide used as a seed coating, was detected in all matrices and remained persistent throughout the year in soil pore water. Tefluthrin, a pyrethroid insecticide applied at planting to control corn rootworm larvae (Diabrotica spp., Coleoptera: Chrysomelidae) populations, was consistently detected in soil, runoff water, and runoff sediment during the corn growing season, but was not detected in groundwater or soil pore water. Tefluthrin did not have an effect on root damage from corn rootworm larvae feeding to Bt corn, but did prevent damage to non-Bt corn. A slight reduction in grain yield was observed in the non-Bt, no tefluthrin treatment when compared to all other treatments, but no significant difference in grain yield was observed among Bt corn treatments regardless of soil insecticide application. In the current study, the use of tefluthrin on Bt corn did not significantly affect crop damage or yield, and tefluthrin may travel off-site in runoff water and sediment.


Assuntos
Proteínas de Bactérias/toxicidade , Endotoxinas/toxicidade , Monitoramento Ambiental , Proteínas Hemolisinas/toxicidade , Inseticidas/toxicidade , Animais , Bacillus thuringiensis , Toxinas de Bacillus thuringiensis , Besouros/efeitos dos fármacos , Meio Ambiente , Larva/efeitos dos fármacos , Plantas Geneticamente Modificadas , Estações do Ano , Zea mays/genética
17.
Talanta ; 128: 109-16, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25059137

RESUMO

The widespread planting of crops expressing insecticidal proteins derived from the soil bacterium Bacillus thuringiensis (Bt) has given rise to concerns regarding potential exposure to non-target species. These proteins are released from the plant throughout the growing season into soil and surface runoff and may enter adjacent waterways as runoff, erosion, aerial deposition of particulates, or plant debris. It is crucial to be able to accurately quantify Bt protein concentrations in the environment to aid in risk analyses and decision making. Enzyme-linked immunosorbent assay (ELISA) is commonly used for quantitation of Bt proteins in the environment; however, there are no published methods detailing and validating the extraction and quantitation of Bt proteins in water. The objective of the current study was to optimize the extraction of a Bt protein, Cry1Ab, from three water matrices and validate the ELISA method for specificity, precision, accuracy, stability, and sensitivity. Recovery of the Cry1Ab protein was matrix-dependent and ranged from 40 to 88% in the validated matrices, with an overall method detection limit of 2.1 ng/L. Precision among two plates and within a single plate was confirmed with a coefficient of variation less than 20%. The ELISA method was verified in field and laboratory samples, demonstrating the utility of the validated method. The implementation of a validated extraction and quantitation protocol adds consistency and reliability to field-collected data regarding transgenic products.


Assuntos
Proteínas de Bactérias/análise , Produtos Agrícolas/metabolismo , Endotoxinas/análise , Proteínas Hemolisinas/análise , Recursos Hídricos/análise , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Produtos Agrícolas/genética , Endotoxinas/genética , Endotoxinas/isolamento & purificação , Monitoramento Ambiental/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Água Subterrânea/análise , Água Subterrânea/química , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/isolamento & purificação , Plantas Geneticamente Modificadas , Estabilidade Proteica , Reprodutibilidade dos Testes , Rios/química , Solo/química , Temperatura , Poluentes da Água/análise , Abastecimento de Água/análise
18.
J Health Psychol ; 19(11): 1400-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23818506

RESUMO

This study (n = 304) examined the relationship between somatic symptoms and social anxiety. Significant differences in the experience of somatic symptoms were found among four groups (i.e. performance anxious, interaction anxious, generalized socially anxious, and controls). Post hoc analyses revealed that those who exceeded the clinical cutoff for generalized social anxiety exhibited more somatic symptoms than those who exceeded the clinical cutoff in the other two social anxiety domains or controls. Individuals in each group exhibited more somatic symptoms than controls, but subtypes did not differ in the amount of somatic symptoms experienced. Additionally, regression analyses revealed that type of somatic symptoms experienced varied depending on subtype.


Assuntos
Transtornos Fóbicos/complicações , Transtornos Somatoformes/complicações , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Inquéritos e Questionários , Adulto Jovem
19.
J Clin Psychol ; 70(3): 260-72, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23843207

RESUMO

OBJECTIVES: Intolerance of uncertainty (IU) is thought to underlie several internalizing disorders; however, it has only begun to be explored within social anxiety (SA). This study extends previous findings by examining IU's relation to performance and interaction SA subtypes and by accounting for obsessive-compulsive symptoms. METHODS: A total of 472 undergraduates completed measures of IU, SA, perfectionism, worry, obsessions/compulsions, and fear of negative evaluation (FNE). RESULTS: IU and obsessions/compulsions predicted performance SA beyond FNE. IU predicted interaction SA beyond FNE. Inhibitory anxiety IU contributed to both SA types but contributed more to performance SA. Prospective anxiety IU was negatively related to performance SA and unrelated to interaction SA, though a trend emerged. Contrasts between those high in one SA type, both, or neither revealed IU was highest when both types were present. CONCLUSIONS: Inhibitory IU plays a significant role in both SA subtypes and may play a slightly greater role in performance SA.


Assuntos
Relações Interpessoais , Transtorno Obsessivo-Compulsivo/psicologia , Ansiedade de Desempenho/psicologia , Transtornos Fóbicos/psicologia , Incerteza , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Adulto Jovem
20.
Cogn Behav Ther ; 43(2): 111-21, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24365129

RESUMO

Social phobia is a frequent co-occurring diagnosis with obsessive-compulsive disorder (OCD); however, co-occurring OCD in those with social phobia is less common. Genetic, environmental, and cognitive traits are common risk factors for anxiety disorders broadly. It is plausible that shared variables related to OCD and/or social phobia could provide insight into the co-occurrence of these two disorders. The current study explored differences in fear of negative evaluation (FNE) and perfectionism among four groups: those with (1) elevated social phobia symptoms, (2) elevated OCD symptoms, (3) elevated symptoms of OCD and social phobia, and those who were (4) asymptomatic as a control group. A non-clinical sample of 196 participants completed several online questionnaires about social phobia and OCD symptomology. Results identified three cognitive variables (i.e., FNE, total perfectionism, and concern over mistakes) as differential variables in comorbid symptom presentation of OCD and social phobia. A fourth variable (i.e., doubts about actions) was identified as a potential dual risk factor, and four subsequent variables (i.e., parental criticism, personal standards, parental expectations, and organization) were not implicated in differential symptom presentation. Given the different rates of OCD and social phobia co-occurrence, identification of differentiating variables could aid in better understanding of potential risk factors, which may enhance preventative and therapeutic techniques. Study implications, limitations, and future recommendations are discussed.


Assuntos
Transtorno Obsessivo-Compulsivo/diagnóstico , Transtornos Fóbicos/diagnóstico , Adolescente , Adulto , Idoso , Autoavaliação Diagnóstica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtorno Obsessivo-Compulsivo/complicações , Transtorno Obsessivo-Compulsivo/psicologia , Transtornos Fóbicos/complicações , Transtornos Fóbicos/psicologia , Avaliação de Sintomas , Adulto Jovem
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