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1.
J. bras. nefrol ; 46(1): 99-106, Mar. 2024. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1534777

RESUMEN

ABSTRACT We present a case of a 69-year-old man who presented for routine check-up and was incidentally found to have kidney failure with an initially unrevealing history and bland urinary sediment. He was diagnosed with oxalate nephropathy in the setting of chronic turmeric supplementation and chronic antibiotic therapy with associated diarrhea. Our case provides several key insights into oxalate nephropathy. First, the diagnosis requires a high index of clinical suspicion. It is uncommonly suspected clinically unless there is an obvious clue in the history such as Roux-en-Y gastric bypass or ethylene glycol poisoning. Diagnosis can be confirmed by histopathologic findings and corroborated by serum levels of oxalate and 24-hour urinary excretion. Second, the diagnosis can often be missed by the pathologist because of the characteristics of the crystals unless the renal pathologist has made it a rule to examine routinely all H&E sections under polarized light. This must be done on H&E, as the other stains dissolve the crystals. Third, one oxalate crystal in a routine needle biopsy is considered pathologic and potentially contributing to the AKI or to the CKD in an important way. Fourth, secondary oxalosis can be largely mitigated or prevented in many cases, especially iatrogenic cases. This can come through the surgeon or the gastroenterologist providing proper instructions to patients on an oxalate-restricted diet or other specific dietary measures. Lastly, this case highlights the success that results from cooperation and communication between the pathologist and the treating physician.


RESUMO Relatamos o caso de um homem de 69 anos que se apresentou para exame de rotina e descobriu-se incidentalmente que ele tinha insuficiência renal, com histórico inicialmente não revelador e sedimento urinário brando. Ele foi diagnosticado com nefropatia por oxalato no contexto de suplementação crônica de cúrcuma e antibioticoterapia crônica com diarreia associada. Nosso caso fornece diversas sugestões importantes sobre nefropatia por oxalato. Primeiro, o diagnóstico requer elevado índice de suspeita clínica. A suspeita clínica é incomum, a menos que haja evidência óbvia no histórico, como bypass gástrico em Y de Roux ou envenenamento por etilenoglicol. O diagnóstico pode ser confirmado por achados histopatológicos e corroborado por níveis séricos de oxalato e excreção urinária de 24 horas. Segundo, o diagnóstico pode passar despercebido pelo patologista devido às características dos cristais, a menos que o patologista renal estabeleça como regra examinar rotineiramente todas as seções coradas com H&E sob luz polarizada. Isso deve ser feito com H&E, pois, outras colorações dissolvem os cristais. Em terceiro lugar, um cristal de oxalato em biópsia por agulha de rotina é considerado patológico, contribuindo potencialmente para LRA ou para DRC de maneira significativa. Em quarto lugar, a oxalose secundária pode ser amplamente mitigada ou prevenida em muitos casos, especialmente casos iatrogênicos. Isso pode ser feito pelo cirurgião ou pelo gastroenterologista, fornecendo instruções adequadas aos pacientes sobre uma dieta restrita em oxalato ou outras medidas dietéticas específicas. Por fim, esse caso destaca o sucesso que resulta da cooperação e comunicação entre o patologista e o médico assistente.

2.
J Bras Nefrol ; 46(1): 99-106, 2024.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-38427579

RESUMEN

We present a case of a 69-year-old man who presented for routine check-up and was incidentally found to have kidney failure with an initially unrevealing history and bland urinary sediment. He was diagnosed with oxalate nephropathy in the setting of chronic turmeric supplementation and chronic antibiotic therapy with associated diarrhea. Our case provides several key insights into oxalate nephropathy. First, the diagnosis requires a high index of clinical suspicion. It is uncommonly suspected clinically unless there is an obvious clue in the history such as Roux-en-Y gastric bypass or ethylene glycol poisoning. Diagnosis can be confirmed by histopathologic findings and corroborated by serum levels of oxalate and 24-hour urinary excretion. Second, the diagnosis can often be missed by the pathologist because of the characteristics of the crystals unless the renal pathologist has made it a rule to examine routinely all H&E sections under polarized light. This must be done on H&E, as the other stains dissolve the crystals. Third, one oxalate crystal in a routine needle biopsy is considered pathologic and potentially contributing to the AKI or to the CKD in an important way. Fourth, secondary oxalosis can be largely mitigated or prevented in many cases, especially iatrogenic cases. This can come through the surgeon or the gastroenterologist providing proper instructions to patients on an oxalate-restricted diet or other specific dietary measures. Lastly, this case highlights the success that results from cooperation and communication between the pathologist and the treating physician.


Asunto(s)
Hiperoxaluria , Insuficiencia Renal , Masculino , Humanos , Anciano , Curcuma , Hiperoxaluria/inducido químicamente , Hiperoxaluria/complicaciones , Insuficiencia Renal/complicaciones , Oxalatos , Suplementos Dietéticos/efectos adversos
3.
Cell Death Dis ; 15(2): 150, 2024 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-38368415

RESUMEN

Complex DNA damage (CDD), containing two or more DNA lesions within one or two DNA helical turns, is a signature of ionising radiation (IR) and contributes significantly to the therapeutic effect through cell killing. The levels and complexity of CDD increases with linear energy transfer (LET), however, the specific cellular response to this type of DNA damage and the critical proteins essential for repair of CDD is currently unclear. We performed an siRNA screen of ~240 DNA damage response proteins to identify those specifically involved in controlling cell survival in response to high-LET protons at the Bragg peak, compared to low-LET entrance dose protons which differ in the amount of CDD produced. From this, we subsequently validated that depletion of 8-oxoguanine DNA glycosylase (OGG1) and poly(ADP-ribose) glycohydrolase (PARG) in HeLa and head and neck cancer cells leads to significantly increased cellular radiosensitivity specifically following high-LET protons, whilst no effect was observed after low-LET protons and X-rays. We subsequently confirmed that OGG1 and PARG are both required for efficient CDD repair post-irradiation with high-LET protons. Importantly, these results were also recapitulated using specific inhibitors for OGG1 (TH5487) and PARG (PDD00017273). Our results suggest OGG1 and PARG play a fundamental role in the cellular response to CDD and indicate that targeting these enzymes could represent a promising therapeutic strategy for the treatment of head and neck cancers following high-LET radiation.


Asunto(s)
ADN Glicosilasas , Neoplasias de Cabeza y Cuello , Humanos , Protones , Transferencia Lineal de Energía , Daño del ADN , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/radioterapia , ADN Glicosilasas/genética , ADN Glicosilasas/metabolismo , Glicósido Hidrolasas/genética , Glicósido Hidrolasas/metabolismo
4.
Anal Chem ; 96(5): 2236-2243, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38277487

RESUMEN

AgCl-coated silver fabricated with the thermal-electrolytic method can be used to prepare more reproducible reference electrodes than Ag/AgCl prepared with alternative methods such as electrolytic and chemical AgCl deposition or thermal fabrication. However, thermal-electrolytic fabrication requires a scaffold material upon which to build the layers upon. Platinum and rhodium have been used for this purpose as they are mechanically strong and chemically inert, but their cost is prohibitive for wider application. Herein, we report the stability of Ag/AgCl reference electrodes built atop a titanium scaffold using the thermal-electrolytic method and the use of these Ti/Ag/AgCl constructs in capillary-based reference electrodes. Electrochemical characterization shows that the probable presence of small amounts of oxygen at the Ti/Ag interface does not affect the reference electrode performance; in particular, over a wide pH range, the half-cell potential is pH independent. The electrical resistance of the Ti/Ag/AgCl/KCl system is dominated by the charge transfer resistance at the interface of the AgCl to KCl solution but is kept very small by the large AgCl surface area and a high solution concentration of chloride. The resulting high exchange current minimizes the effect of system impurities on the reference half-cell potential. Capillary-based reference electrodes comprising Ti/Ag/AgCl show exceptionally low potential drifts (as low as 0.03 ± 2.01 µV/h) and standard deviations of the potential at or below ±0.5 mV over a 60 h period. These capillary-based reference electrodes are suitable for very small sample volumes while still providing a free-flowing liquid junction that prevents reference electrode contamination.

5.
J Homosex ; 71(4): 1003-1029, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-36625543

RESUMEN

There is ongoing debate regarding the culture of competitive women's sports. On one hand, women who participate in sports are viewed as adhering to and reinforcing heteronormative stereotypes and hegemonic masculinity. Conversely, women's sports are viewed as an inherently supportive environment for those involved. The current study explored the latter phenomena, specifically related to factors that promote an inclusive and empowering community for LGBTQ+ women. Eleven individual semi-structured interviews and one follow-up focus group with six participants were conducted with women from a collegiate women's rugby club team. All participants described their sexual identities as Lesbian, Gay, Bisexual, and/or Queer (LGBQ). A reflexive thematic analysis was used to analyze the data collectively. Participants described their collegiate rugby team as being one of their first encounters with a safe and inclusive LGBTQ+ environment. Membership on the team also was viewed as an important experience that helped participants come to terms with their sexual identity. Specifically, findings indicate the supportive actions of teammates, an inclusive team culture, and unique factors related to the sport of rugby helped promote an inclusive and empowering community for LGBTQ+ women. Indeed, from a critical positive youth development perspective, social justice life skills (e.g., allyship) provided actionable behaviors that promote an inclusive and empowering community for LGBTQ+ women. However, future research must seek to understand the lived experiences of all women's rugby participants, particularly transgender and athletes of color.


Asunto(s)
Homosexualidad Femenina , Minorías Sexuales y de Género , Masculino , Adolescente , Humanos , Femenino , Rugby , Atletas , Poder Psicológico
7.
Front Neuroimaging ; 2: 1129587, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37554654

RESUMEN

Introduction: Cannabis is the most widely used regulated substance by youth and adults. Cannabis use has been associated with psychosocial problems, which have been partly ascribed to neurobiological changes. Emerging evidence to date from diffusion-MRI studies shows that cannabis users compared to controls show poorer integrity of white matter fibre tracts, which structurally connect distinct brain regions to facilitate neural communication. However, the most recent evidence from diffusion-MRI studies thus far has yet to be integrated. Therefore, it is unclear if white matter differences in cannabis users are evident consistently in selected locations, in specific diffusion-MRI metrics, and whether these differences in metrics are associated with cannabis exposure levels. Methods: We systematically reviewed the results from diffusion-MRI imaging studies that compared white matter differences between cannabis users and controls. We also examined the associations between cannabis exposure and other behavioral variables due to changes in white matter. Our review was pre-registered in PROSPERO (ID: 258250; https://www.crd.york.ac.uk/prospero/). Results: We identified 30 diffusion-MRI studies including 1,457 cannabis users and 1,441 controls aged 16-to-45 years. All but 6 studies reported group differences in white matter integrity. The most consistent differences between cannabis users and controls were lower fractional anisotropy within the arcuate/superior longitudinal fasciculus (7 studies), and lower fractional anisotropy of the corpus callosum (6 studies) as well as higher mean diffusivity and trace (4 studies). Differences in fractional anisotropy were associated with cannabis use onset (4 studies), especially in the corpus callosum (3 studies). Discussion: The mechanisms underscoring white matter differences are unclear, and they may include effects of cannabis use onset during youth, neurotoxic effects or neuro adaptations from regular exposure to tetrahydrocannabinol (THC), which exerts its effects by binding to brain receptors, or a neurobiological vulnerability predating the onset of cannabis use. Future multimodal neuroimaging studies, including recently developed advanced diffusion-MRI metrics, can be used to track cannabis users over time and to define with precision when and which region of the brain the white matter changes commence in youth cannabis users, and whether cessation of use recovers white matter differences. Systematic review registration: www.crd.york.ac.uk/prospero/, identifier: 258250.

8.
LGBT Health ; 10(6): 429-438, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37126404

RESUMEN

Purpose: Patient empowerment is becoming increasingly important as health care moves toward more collaborative models of care. The goal of this study was to evaluate and characterize patient empowerment in a sample of transgender/gender-diverse/nonbinary (TGDNB) youth aged 14-24 who have had at least one conversation with a medical health care provider about gender-affirming care. Methods: We adapted a health care empowerment scale for use with TGDNB young people and collected patient empowerment and sociodemographic data among TGDNB youth in the United States over an 8-week period in the spring of 2022. Overall and domain-specific empowerment (including knowledge and understanding, control, identity, decision-making, and supporting others) were assessed on a four-point scale from a low of 1 to a high of 4. Results: A total of 177 youth completed the survey. Mean age was 18.4 ± 3.0 years, the sample was 39.5% gender-diverse/nonbinary, 16.4% transfemme, 44.1% transmasc, and 81.9% White. Average empowerment was 0.22 points higher in youth with supportive caregivers than those without (99% confidence interval [CI] 0.05-0.38, p < 0.001) and 0.20 points higher in youth who sought gender-affirming mental health support (99% CI 0.04-0.36, p = 0.001). Caregiver support increased youths' sense of control over their health/health care (estimated increase 0.29, 99% CI 0.09-0.50, p < 0.001), and mental health support increased youths' decision-making agency by 0.30 points (99% CI 0.06-0.53, p = 0.001). Conclusions: This is the first study to assess patient empowerment in TGDNB youth. Several sociodemographic factors were significantly associated with overall and domain-level empowerment. Further work in this area, both longitudinal and in larger samples, is warranted.


Asunto(s)
Personas Transgénero , Transexualidad , Humanos , Adolescente , Estados Unidos , Adulto Joven , Adulto , Personas Transgénero/psicología , Participación del Paciente , Identidad de Género , Encuestas y Cuestionarios
9.
Zoonoses Public Health ; 70(4): 294-303, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36628930

RESUMEN

Lyme disease risk areas have increased across Canada in recent decades with the ongoing range expansion of Ixodes scapularis and Borrelia burgdorferi. Different methodologies are used by federal and provincial governments to determine local Lyme disease risk, which can make comparisons between regions challenging. In this study, seven Canadian Lyme disease risk classification methodologies were compared with each other to highlight the strengths and limitations of how each definition measured I. scapularis and B. burgdorferi risk. Each methodology was applied to active surveillance data from Ontario, and per cent agreement and kappa statistics were calculated. The methodologies varied in their measurements of the risk of exposure to I. scapularis and B. burgdorferi based on their use of active surveillance techniques, multiple types of collected surveillance data and laboratory confirmation of B. burgdorferi. Most initial Lyme disease risk site classifications were maintained over time. Kappa and per cent agreement statistics highlighted large differences between 8 of the 15 methodology pairings, indicating the presence of inconsistencies between most methodologies. Accurate, consistent surveillance and assessment of the spread of I. scapularis and its pathogens will aid with communicating Lyme disease risk to the public and preventing tick-borne pathogen transmission.


Asunto(s)
Borrelia burgdorferi , Ixodes , Enfermedad de Lyme , Animales , Enfermedad de Lyme/epidemiología , Enfermedad de Lyme/veterinaria , Ontario/epidemiología , Recolección de Datos
10.
Proteins ; 91(1): 99-107, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-35988049

RESUMEN

Arrestins are important scaffolding proteins that are expressed in all vertebrate animals. They regulate cell-signaling events upon binding to active G-protein coupled receptors (GPCR) and trigger endocytosis of active GPCRs. While many of the functional sites on arrestins have been characterized, the question of how these sites interact is unanswered. We used anisotropic network modeling (ANM) together with our covariance compliment techniques to survey all the available structures of the nonvisual arrestins to map how structural changes and protein-binding affect their structural dynamics. We found that activation and clathrin binding have a marked effect on arrestin dynamics, and that these dynamics changes are localized to a small number of distant functional sites. These sites include α-helix 1, the lariat loop, nuclear localization domain, and the C-domain ß-sheets on the C-loop side. Our techniques suggest that clathrin binding and/or GPCR activation of arrestin perturb the dynamics of these sites independent of structural changes.


Asunto(s)
Arrestina , Arrestinas , Animales , Arrestinas/metabolismo , beta-Arrestinas/metabolismo , Arrestina/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Clatrina/metabolismo
11.
Hand (N Y) ; : 15589447221131847, 2022 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-36424817

RESUMEN

BACKGROUND: The purpose of this study was to assess the quality of evidence informing on common pharmacologic modalities used in upper extremity complex regional pain syndrome (CRPS). METHODS: A literature search was performed for primary prospective trials that reported on the pharmacologic treatment of CRPS type I and II specific to the upper extremity. Thirty-one trials were included and evaluated by 2 independent reviewers according to the Oxford Levels of Evidence (LOE), modified Coleman Methodology Score, and the revised Consolidated Standards of Reporting Trials (CONSORT) score. Cohen's kappa coefficient was calculated to measure interrater reliability. RESULTS: Twenty-two Oxford LOE I and 9 level II trials met the inclusion criteria. Overall, there was high interrater reliability in the Oxford LOE (100% agreement), modified Coleman Methodology Score (87% agreement), and CONSORT score (94% agreement). The pharmacologic interventions with the highest quality of evidence supporting use in treatment of upper extremity CRPS were bisphosphonates and ketamine. Interventions that lack high-quality evidence are tricyclic antidepressants (TCAs) and topical dimethyl sulfoxide (DMSO). Pharmacologic agents that remain inconclusive are calcitonin, gabapentin, mycophenolate, probiotics, steroids, nonsteroidal anti-inflammatory drugs, vitamin C, and N-acetylcysteine. Agents with limited benefit are mannitol, isosorbide dinitrate, guanethidine, and morphine. CONCLUSIONS: Based on the evidence evaluated in this study, bisphosphonates should be considered as a first-line medication in the treatment of CRPS. In patients presenting with chronic or refractory CRPS, strong consideration should be given for the use of ketamine. Adjunct treatment in the acute setting should include TCAs and/or topical DMSO.

13.
J Thorac Dis ; 14(9): 3304-3313, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36245601

RESUMEN

Background: The present study aims to report the early effect of the coronavirus disease 2019 (COVID-19) pandemic on the cardiothoracic surgery job market in North America. Methods: The Cardiothoracic Surgery Network (CTSNet) job market database was queried, and patterns from January to May for 2019 versus January to May 2020 were compared for trends in job postings and job seekers. Results: Our study is comprised of 395 cardiothoracic surgery job postings, of which 98% were positions located in North America and 63% were academic. The negative impact of the pandemic on the cardiothoracic surgery job market was greatest in the cardiothoracic/cardiovascular combined subspecialty, followed by congenital and adult cardiac surgery, whereas general thoracic surgery experienced an increase in proportion of jobs available. Despite an increase in views per job posted in 2020 vs. 2019 (532 vs. 290), employer views of job seeker curriculum vitae declined over the same time period in 2020 (January, 380 views/month to May, 3 views/month) compared to 2019 (January, 100 views/month to May, 54 views/month). Conclusions: An analysis of job postings from CTSNet suggests a decline in job availability in the North American cardiothoracic surgical job market following declaration of the pandemic with acknowledgement that there is month to month variability and a supply-demand mismatch. The COVID-19 pandemic has had an unprecedented impact on our field, and the ultimate consequences remain unknown.

14.
Cureus ; 14(8): e28549, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36185860

RESUMEN

Background and objective Athletics is the leading cause of pediatric concussion, and depression is a major comorbidity associated with concussion in the pediatric population. Prior studies have described the risk of depression after concussion in high school-, collegiate-, and elite-level athletes, but there is scarce data on younger athletes. Interpretation of existing research on the association of depression with concussions in youth athletes is complicated by diverse study designs, varying measures of depression, differing timelines for symptom development, and a lack of control groups. Furthermore, limited research exists on sex-related differences in the development of depressive symptoms following sports-related concussions (SRC) in younger athletes. This study used the Seattle Pediatric Concussion Research Collaborative (SPCRC) Data Repository to compare depressive symptoms between youth athletes at one month post-SRC and non-concussed age-matched controls by using a standardized measure of depressive symptoms: the Patient Health Questionnaire-9 (PHQ-9). The secondary goal was to compare PHQ-9 scores between males and females for both concussed and non-concussed groups. Methods This study entailed a secondary analysis of data collected as part of the SPCRC Data Repository. We conducted a retrospective subgroup analysis of PHQ-9 scores at one month post-concussion for concussed youth athletes. We compared the PHQ9 scores of concussed youth athletes with PHQ-9 scores collected at the time of enrollment for non-concussed youth athletes. Results After random age-matching, a cohort of 266 patients (133 in the concussed group and 133 in the non-concussed control group) was included in the final analysis. The mean age was 13.8 years (range: 5-18 years). For the concussed group, a history of SRC was associated with a higher mean total PHQ-9 score at one month post-concussion compared with the control group at the time of enrollment (6.14 ±5.46 versus 1.53 ±1.81, respectively, p<0.0001). All nine subdomains of the PHQ-9 showed significantly higher scores in the concussion group compared with the control group (p<0.0001). Significantly higher scores were observed when comparing mean total PHQ-9 scores for male athletes in the concussion group with male athletes in the control group (7.03 ±5.72 versus 1.59 ±1.66, p<0.0001) and for female athletes in the concussion group compared with female controls (5.28 ±5.10 versus 1.49 ±1.92, p<0.0001). No significant differences were observed between sexes for total PHQ-9 scores or PHQ-9 subscores. Conclusion At one month post concussion, youth with SRC demonstrated higher levels of depressive symptoms as measured by PHQ-9 compared with age-matched typically developing controls. No significant differences were identified in total PHQ-9 scores and subscores between male and female participants for either the concussion or control group. This study suggests that clinicians need to be vigilant and monitor for symptoms of depression in young athletes for at least one month post-concussion.

15.
J Microbiol Biol Educ ; 23(2)2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36061330

RESUMEN

Clicker questions are a commonly used active learning technique that stimulates student interactions to help advance understanding of key concepts. Clicker questions are often administered with an initial vote, peer discussion, and a second vote, followed by broader classroom explanation. While clickers can promote learning, some studies have questioned whether students maintain this performance on later exams, highlighting the need to further understand how student answer patterns relate to their understanding of the material and to identify ways for clickers to benefit a broader range of students. Systematic requizzing of concepts during at-home assignments represents a promising mechanism to improve student learning. Thus, we paired clicker questions with at-home follow-up reflections to help students articulate and synthesize their understandings. This pairing of clickers with homework allowed us to decipher how student answer patterns related to their underlying conceptions and to determine if revisiting concepts provided additional benefits. We found that students answering both clicker votes correctly performed better on isomorphic exam questions and that students who corrected their answers after the first vote did not show better homework or exam performance than students who maintained an incorrect answer across both votes. Furthermore, completing the follow-up homework assignment modestly boosted exam question performance. Our data suggest that longer-term benefits of clickers and associated homework may stem from students having repeated opportunities to retrieve, refine, and reinforce emerging conceptions.

16.
Pestic Biochem Physiol ; 187: 105173, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36127039

RESUMEN

Declines of the monarch butterfly population have prompted large-scale plantings of milkweed to restore the population. In North America, there are >73 species of milkweed to choose from for these nationwide plantings. However, it is unclear how different milkweed species affect monarch caterpillar physiology, particularly detoxification enzyme activity and gene expression, given the highly variable cardenolide composition across milkweed species. Here, we investigate the effects of a high cardenolide, tropical milkweed species and a low cardenolide, swamp milkweed species on pyrethroid sensitivity as well as detoxification enzyme activity and expression in monarch caterpillars. Caterpillars fed on each species through the fifth-instar stage and were topically treated with bifenthrin after reaching this final-instar stage. Esterase, glutathione S-transferase, and cytochrome P450 monooxygenase activities were quantified as well as the expression of selected esterase, glutathione S-transferase, ABC transporter, and cytochrome P450 monooxygenase transcripts. There were no significant differences in survival 24 h after treatment with bifenthrin. However, bifenthrin significantly increased glutathione S-transferase activity in caterpillars feeding on tropical milkweed and significantly decreased esterase activity in caterpillars feeding on tropical and swamp milkweed. Significant differential expression of ABC transporter, glutathione S-transferase, and esterase genes was observed for caterpillars feeding on tropical and swamp milkweed and not receiving bifenthrin treatment. Furthermore, significant differential expression of glutathione S-transferase and esterase genes was observed for bifenthrin-treated and -untreated caterpillars feeding on tropical milkweed relative to swamp milkweed. These results suggest that feeding on different milkweed species can affect detoxification and development mechanisms with which monarch caterpillars rely on to cope with their environment.


Asunto(s)
Asclepias , Mariposas Diurnas , Insecticidas , Piretrinas , Transportadoras de Casetes de Unión a ATP , Animales , Asclepias/metabolismo , Mariposas Diurnas/genética , Cardenólidos/metabolismo , Esterasas/genética , Esterasas/metabolismo , Glutatión Transferasa/genética , Glutatión Transferasa/metabolismo , Insecticidas/metabolismo , Insecticidas/toxicidad , Oxigenasas de Función Mixta/metabolismo , Piretrinas/metabolismo , Piretrinas/toxicidad
17.
J Econ Entomol ; 115(4): 1177-1190, 2022 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-35786723

RESUMEN

Relative to fallow-cash crop rotations, the addition of a cover crop can contribute to greater plant diversity and has the potential to conserve predatory arthropods. The transition of arthropods from a cover crop to a subsequent cash crop depends on several factors, such as cover crop biomass production and weather conditions. Information about the effect of cover crop planting and termination dates on arthropods in a subsequent corn system is limited. A two-year field study was conducted in Nebraska in 2018/2019 and 2019/2020 to evaluate the impact of cover crop planting and termination dates as a source for arthropods in the subsequent corn. A total of 38,074 and 50,626 arthropods were collected in the first and second year, respectively. In both years, adding a grass cover crop increased predatory arthropods but reduced yield in follow corn crop. Of the arthropods collected, Carabidae and Araneae had greater activity with cover crop biomass increments, whereas Collembola and Acari activity only increased in treatments with little or no cover crop biomass. Insect pest pressure was not significant in any treatment for either year. A cover crop planted in mid- or late-September and terminated at corn planting was identified as the best management strategy to maximize cover crop biomass, increase predator activity, and modify predator-prey dynamics. The results of this study provide growers with a cover crop management strategy to maximize cover crop biomass, beneficial arthropod activity, and potentially minimize insect pest problems; however, corn Zea Mays (L.) grain yield was reduced as cover crop biomass increased.


Asunto(s)
Artrópodos , Zea mays , Agricultura/métodos , Animales , Biomasa , Producción de Cultivos/métodos , Estaciones del Año
18.
Vector Borne Zoonotic Dis ; 22(7): 361-369, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35727121

RESUMEN

Range expansion of the vector tick species, Ixodes scapularis, has been detected in Ontario over the last two decades. This has led to elevated risk of exposure to Borrelia burgdorferi, the bacterium that causes Lyme disease. Previous research using passive surveillance data suggests that I. scapularis populations establish before the establishment of B. burgdorferi transmission cycles, with a delay of ∼5 years. The objectives of this research were to examine spatial and temporal patterns of I. scapularis and its pathogens from 2017 to 2019 in southwestern, eastern, and central Ontario, and to explore patterns of B. burgdorferi invasion. Over the 3-year study period, drag sampling was conducted at 48 sites across Ontario. I. scapularis ticks were tested for B. burgdorferi, Borrelia miyamotoi, Anaplasma phagocytophilum, and Babesia species, including Babesia microti and Babesia odocoilei, and Powassan virus. I. scapularis was detected at 30 sites overall, 22 of which had no history of previous tick detection. B. burgdorferi was detected at nine sites, eight of which tested positive for the first time during this study and five of which had B. burgdorferi detected concurrently with initial tick detection. Tick and pathogen hotspots were identified in eastern Ontario in 2017 and 2018, respectively. These findings provide additional evidence on the range expansion and population establishment of I. scapularis in Ontario and help generate hypotheses on the invasion of B. burgdorferi in Ontario. Ongoing public health surveillance is critical to monitor changes in I. scapularis and its pathogens in Ontario.


Asunto(s)
Vectores Arácnidos/fisiología , Borrelia burgdorferi/fisiología , Ixodes/fisiología , Enfermedad de Lyme/epidemiología , Anaplasma phagocytophilum/clasificación , Anaplasma phagocytophilum/aislamiento & purificación , Animales , Vectores Arácnidos/microbiología , Babesia/clasificación , Babesia/aislamiento & purificación , Virus de la Encefalitis Transmitidos por Garrapatas/aislamiento & purificación , Ixodes/microbiología , Enfermedad de Lyme/transmisión , Ontario/epidemiología
19.
PLoS One ; 17(5): e0268902, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35613094

RESUMEN

The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is an economically important pest of field corn (Zea mays L.) across the United States (U.S.) Corn Belt. Repeated use of transgenic hybrids expressing Bacillus thuringiensis (Bt) proteins has selected for field-evolved resistance to all current rootworm-active Bt proteins. The newest product available for WCR management is SmartStax® PRO, a rootworm-active pyramid containing Cry3Bb1, Cry34/35Ab1 [now reclassified as Gpp34Ab1/Tpp35Ab1] and a new mode of action, DvSnf7 dsRNA. Understanding the fitness of adult WCR after dietary exposure to SmartStax® PRO will identify potential impacts on WCR population dynamics and inform efforts to optimize resistance management strategies. Therefore, the objective of the present study was to characterize the effect of SmartStax® PRO dietary exposure on WCR life history traits. Adult WCR were collected during 2018 and 2019 from emergence tents placed over replicated field plots of SmartStax® PRO or non-rootworm Bt corn at a site with a history of rootworm-Bt trait use and suspected resistance to Cry3Bb1 and Cry34/35Ab1. Adult survival was reduced by 97.1-99.7% in SmartStax® PRO plots relative to the non-rootworm Bt corn plots during the study. Individual male/female pairs were fed different diets of ear tissue to simulate lifetime or adult exposure. Life history parameters measured included adult longevity, adult head capsule width, lifetime female egg production, and egg viability. Results indicate that lifetime or adult exposure to SmartStax® PRO significantly reduced adult longevity and lifetime egg production. Larval exposure to SmartStax® PRO significantly reduced WCR adult size. Results from this study collectively suggest that SmartStax® PRO may negatively impact WCR life history traits, which may lead to reduced population growth when deployed in an area with WCR resistance to Bt traits.


Asunto(s)
Bacillus thuringiensis , Escarabajos , Rasgos de la Historia de Vida , Animales , Bacillus thuringiensis/genética , Proteínas Bacterianas/genética , Escarabajos/genética , Exposición Dietética , Endotoxinas/genética , Femenino , Resistencia a los Insecticidas/genética , Larva , Control Biológico de Vectores , Plantas Modificadas Genéticamente/genética , Zea mays/genética
20.
Insects ; 13(4)2022 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-35447789

RESUMEN

Cover crops provide a habitat for pests and beneficial arthropods. Unexpected pest pressure in a cover-crop-to-corn system can occur and result in increased use of insecticides. Eight site-years of on-farm field studies were conducted in 2019, 2020, and 2021. The objective of the study was to evaluate the impact of insecticide timing relative to cover-crop termination on arthropod activity in a cover-crop-to-corn system. The treatments consisted of (i) glyphosate to terminate the cover crop, (ii) glyphosate and pyrethroid tank mix to terminate the cover crop, and (iii) glyphosate to terminate the cover crop and pyrethroid application 25 days after the termination. Arthropod activity was measured with pitfall traps before and at each treatment application. A total of 33,316 arthropods were collected. Total arthropods, Collembola, and Aphididae were the only taxa reduced with an insecticide application. The other arthropod taxa were mainly influenced by the sampling period. No significant pest pressure occurred at any site-year. Insecticide applications are not generally needed in a cover-crop-to-corn system. Scouting for pests and applying strategies only when necessary is crucial to conserve potentially beneficial arthropods in the system.

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