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The present retrospective study evaluated intraocular pressure (IOP) and medication burden after bimatoprost sustained-release (bimatoprost SR, Durysta, Allergan) implantation in patients with glaucoma. A secondary objective was to examine an effect of bimatoprost SR in a subset of patients with prior minimally invasive and incisional glaucoma surgery. A retrospective chart review of 122 eyes that received bimatoprost SR by 6 glaucoma specialists at Wills Eye Hospital between March 2020 and September 2021 was performed. One hundred and eighteen eyes from 84 patients had a reduction in IOP (18.5±5.7mmHg vs. 16.0±5.4mmHg, P<0.01) and required fewer glaucoma medications (2.1±1.4 vs. 1.2±1.2, P<0.01) after bimatoprost SR implantation. In 41 eyes from 31 patients who previously underwent glaucoma surgery (including iStent, goniotomy, trabeculectomy, Xen Gel Stent, or tube shunt surgery), medication burden was decreased after bimatoprost SR implantation (1.9±1.3 vs. 1.0±1.0, P<0.001). These data suggest that bimatoprost SR is an efficacious treatment modality for glaucoma, even in post-surgical patients.
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Glaucoma , Pressão Intraocular , Humanos , Bimatoprost/efeitos adversos , Estudos Retrospectivos , Preparações de Ação Retardada/uso terapêutico , Glaucoma/tratamento farmacológico , Glaucoma/cirurgia , Glaucoma/induzido quimicamente , Resultado do TratamentoRESUMO
BACKGROUND: Sasanlimab is an antibody to the programmed cell death protein 1 receptor. We report updated data of subcutaneous sasanlimab in non-small-cell lung cancer (NSCLC) and urothelial carcinoma dose expansion cohorts from a first-in-human phase Ib/II study. PATIENTS AND METHODS: Patients were ≥18 years of age with NSCLC or urothelial carcinoma, and no prior immunotherapies, who progressed on or were intolerant to systemic therapy, or for whom systemic therapy was refused or unavailable. Patients received subcutaneous sasanlimab at 300 mg every 4 weeks (q4w). Primary objectives were to evaluate safety, tolerability, and clinical efficacy by objective response rate (ORR). RESULTS: Sixty-eight and 38 patients with NSCLC and urothelial carcinoma, respectively, received subcutaneous sasanlimab. Overall, sasanlimab was well tolerated; 13.2% of patients experienced grade ≥3 treatment-related adverse events. Confirmed ORR was 16.4% and 18.4% in the NSCLC and urothelial carcinoma cohorts, respectively. ORR was generally higher in patients with high programmed death-ligand 1 (PD-L1) expression (≥25%) and high tumor mutational burden (TMB; >75%). In the NSCLC and urothelial carcinoma cohorts, median progression-free survival (PFS) was 3.7 and 2.9 months, respectively; corresponding median overall survival (OS) was 14.7 and 10.9 months. Overall, longer median PFS and OS correlated with high PD-L1 expression and high TMB. Longer median PFS and OS were also associated with T-cell inflamed gene signature in the urothelial carcinoma cohort. CONCLUSIONS: Subcutaneous sasanlimab at 300 mg q4w was well tolerated with promising clinical efficacy observed. Phase II and III clinical trials of sasanlimab are ongoing to validate clinical benefit. Subcutaneous sasanlimab may be a potential treatment option for patients with NSCLC or urothelial carcinoma.
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Carcinoma Pulmonar de Células não Pequenas , Carcinoma de Células de Transição , Neoplasias Pulmonares , Neoplasias da Bexiga Urinária , Humanos , Antígeno B7-H1 , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma de Células de Transição/tratamento farmacológico , Inibidores de Checkpoint Imunológico/efeitos adversos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias da Bexiga Urinária/tratamento farmacológico , Adolescente , AdultoRESUMO
Background: Transgender healthcare is a rapidly evolving interdisciplinary field. In the last decade, there has been an unprecedented increase in the number and visibility of transgender and gender diverse (TGD) people seeking support and gender-affirming medical treatment in parallel with a significant rise in the scientific literature in this area. The World Professional Association for Transgender Health (WPATH) is an international, multidisciplinary, professional association whose mission is to promote evidence-based care, education, research, public policy, and respect in transgender health. One of the main functions of WPATH is to promote the highest standards of health care for TGD people through the Standards of Care (SOC). The SOC was initially developed in 1979 and the last version (SOC-7) was published in 2012. In view of the increasing scientific evidence, WPATH commissioned a new version of the Standards of Care, the SOC-8. Aim: The overall goal of SOC-8 is to provide health care professionals (HCPs) with clinical guidance to assist TGD people in accessing safe and effective pathways to achieving lasting personal comfort with their gendered selves with the aim of optimizing their overall physical health, psychological well-being, and self-fulfillment. Methods: The SOC-8 is based on the best available science and expert professional consensus in transgender health. International professionals and stakeholders were selected to serve on the SOC-8 committee. Recommendation statements were developed based on data derived from independent systematic literature reviews, where available, background reviews and expert opinions. Grading of recommendations was based on the available evidence supporting interventions, a discussion of risks and harms, as well as the feasibility and acceptability within different contexts and country settings. Results: A total of 18 chapters were developed as part of the SOC-8. They contain recommendations for health care professionals who provide care and treatment for TGD people. Each of the recommendations is followed by explanatory text with relevant references. General areas related to transgender health are covered in the chapters Terminology, Global Applicability, Population Estimates, and Education. The chapters developed for the diverse population of TGD people include Assessment of Adults, Adolescents, Children, Nonbinary, Eunuchs, and Intersex Individuals, and people living in Institutional Environments. Finally, the chapters related to gender-affirming treatment are Hormone Therapy, Surgery and Postoperative Care, Voice and Communication, Primary Care, Reproductive Health, Sexual Health, and Mental Health. Conclusions: The SOC-8 guidelines are intended to be flexible to meet the diverse health care needs of TGD people globally. While adaptable, they offer standards for promoting optimal health care and guidance for the treatment of people experiencing gender incongruence. As in all previous versions of the SOC, the criteria set forth in this document for gender-affirming medical interventions are clinical guidelines; individual health care professionals and programs may modify these in consultation with the TGD person.
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NYX-2925 [(2S,3R)-3-hydroxy-2-((R)-5-isobutyryl-1-oxo-2,5-diazaspiro[3.4]octan-2-yl)butanamide] is a novel N-methyl-d-aspartate (NMDA) receptor modulator that is currently being investigated in phase 2 clinical studies for the treatment of painful diabetic peripheral neuropathy and fibromyalgia. Previous studies demonstrated that NYX-2925 is a member of a novel class of NMDA receptor-specific modulators that affect synaptic plasticity processes associated with learning and memory. Studies here examined NYX-2925 administration in rat peripheral chronic constriction nerve injury (CCI) and streptozotocin-induced diabetic mechanical hypersensitivity. Additionally, NYX-2925 was examined in formalin-induced persistent pain model and the tail flick test of acute nociception. Oral administration of NYX-2925 resulted in rapid and long-lasting analgesia in both of the neuropathic pain models and formalin-induced persistent pain, but was ineffective in the tail flick model. The analgesic effects of NYX-2925 were blocked by the systemic administration of NMDA receptor antagonist 3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid. Microinjection of NYX-2925 into the medial prefrontal cortex of CCI rats resulted in analgesic effects similar to those observed following systemic administration, whereas intrathecal administration of NYX-2925 was ineffective. In CCI animals, NYX-2925 administration reversed deficits seen in a rat model of rough-and-tumble play. Thus, it appears that NYX-2925 may have therapeutic potential for the treatment of neuropathic pain, and the data presented here support the idea that NYX-2925 may act centrally to ameliorate pain and modulate negative affective states associated with chronic neuropathic pain.
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Analgésicos/farmacologia , Neuralgia/tratamento farmacológico , Neuralgia/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Compostos de Espiro/farmacologia , Analgésicos/uso terapêutico , Animais , Modelos Animais de Doenças , Masculino , Ratos , Ratos Sprague-Dawley , Compostos de Espiro/uso terapêutico , Vocalização Animal/efeitos dos fármacosRESUMO
BACKGROUND: The best outcomes following Acute Compartment Syndrome (ACS) are attributed to early diagnosis and treatment. National guidelines were issued in the United Kingdom in 2014 (BOAST 10) to standardise and improve management. We analysed standards of diagnosis and management before and after the introduction of the guidelines. METHODS: We retrospectively reviewed the data of all patients with ACS requiring fasciotomy between March 2010 and May 2015 across four Major Trauma Centres (MTCs) in the Northwest of England. We analysed the pooled data for variations between the centres and the effect of BOAST10 implementation. RESULTS: 75 fasciotomies were recorded, with trauma being the cause in 42 cases (56%). The commonest site was the leg (44, 59%) followed by the forearm (15, 20%). The median time from decision to operate to fasciotomy was 2â¯h (range 0-6) and thereafter a median of 2â¯days (1-7) until a second visit. The practice across the four centres was similar up to diagnosis and treatment, but there was significant variation in practice after fasciotomy. The BOAST guidelines did not improve the time to surgery, time to second visit nor the recording of clinical signs. 21 patients had severe complications, including one death and 4 amputations. CONCLUSIONS: There continues to be significant variability in the definitive management of ACS. National guidelines do not appear to make a discernible impact on practice, and additional methods of ensuring safe management of this critical condition seem warranted.
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Síndromes Compartimentais/terapia , Fasciotomia/métodos , Ferimentos e Lesões/fisiopatologia , Doença Aguda , Síndromes Compartimentais/etiologia , Síndromes Compartimentais/fisiopatologia , Humanos , Guias de Prática Clínica como Assunto , Estudos Retrospectivos , Ferimentos e Lesões/complicaçõesRESUMO
BACKGROUND: Substance use disorder (SUD) remains a significant public health issue. A greater understanding of how genes and environment interact to regulate phenotypes comprising SUD will facilitate directed treatments and prevention. METHODS: The literature studying the neurobiological correlates of SUD with a focus on the genetic and environmental influences underlying these mechanisms was reviewed. Results from twin/family, human genetic association, gene-environment interaction, epigenetic literature, phenome-wide association studies are summarized for alcohol, nicotine, cannabinoids, cocaine, and opioids. RESULTS: There are substantial genetic influences on SUD that are expected to influence multiple neurotransmission pathways, and these influences are particularly important within the dopaminergic system. Genetic influences involved in other aspects of SUD etiology including drug processing and metabolism are also identified. Studies of gene-environment interaction emphasize the importance of environmental context in SUD. Epigenetic studies indicate drug-specific changes in gene expression as well as differences in gene expression related to the use of multiple substances. Further, gene expression is expected to differ by stage of SUD such as substance initiation versus chronic substance use. While a substantial literature has developed for alcohol and nicotine use disorders, there is comparatively less information for other commonly abused substances. CONCLUSIONS: A better understanding of genetically-mediated mechanisms involved in the neurobiology of SUD provides increased opportunity to develop behavioral and biologically based treatment and prevention of SUD.
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Alcoolismo/epidemiologia , Epidemiologia Molecular , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Tabagismo/epidemiologia , Interação Gene-Ambiente , Humanos , Fenótipo , GêmeosRESUMO
Tobacco smoking remains the leading cause of preventable death worldwide and current smoking cessation medications have limited efficacy. Thus, there is a clear need for translational research focused on identifying novel pharmacotherapies for nicotine addiction. Our previous studies demonstrated that acute administration of an acetylcholinesterase inhibitor (AChEI) attenuates nicotine taking and seeking in rats and suggest that AChEIs could be repurposed for smoking cessation. Here, we expand upon these findings with experiments designed to determine the effects of repeated AChEI administration on voluntary nicotine taking in rats as well as smoking behavior in human smokers. Rats were trained to self-administer intravenous infusions of nicotine (0.03 mg kg(-1) per 0.59 ml) on a fixed-ratio-5 schedule of reinforcement. Once rats maintained stable nicotine taking, galantamine or donepezil was administered before 10 consecutive daily nicotine self-administration sessions. Repeated administration of 5.0 mg kg(-1) galantamine and 3.0 mg kg(-1) donepezil attenuated nicotine self-administration in rats. These effects were reinforcer-specific and not due to adverse malaise-like effects of drug treatment as repeated galantamine and donepezil administration had no effects on sucrose self-administration, ad libitum food intake and pica. The effects of repeated galantamine (versus placebo) on cigarette smoking were also tested in human treatment-seeking smokers. Two weeks of daily galantamine treatment (8.0 mg (week 1) and 16.0 mg (week 2)) significantly reduced smoking rate as well as smoking satisfaction and reward compared with placebo. This translational study indicates that repeated AChEI administration reduces nicotine reinforcement in rats and smoking behavior in humans at doses not associated with tolerance and/or adverse effects.
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Inibidores da Colinesterase/farmacologia , Nicotina/administração & dosagem , Prevenção do Hábito de Fumar , Adolescente , Adulto , Animais , Inibidores da Colinesterase/administração & dosagem , Donepezila , Feminino , Galantamina/administração & dosagem , Galantamina/farmacologia , Humanos , Indanos/administração & dosagem , Indanos/farmacologia , Masculino , Pessoa de Meia-Idade , Piperidinas/administração & dosagem , Piperidinas/farmacologia , Ratos , Adulto JovemRESUMO
RATIONALE: N-acetylcysteine can increase extrasynaptic glutamate and reduce nicotine self-administration in rats and smoking rates in humans. OBJECTIVES: The aim of this study was to determine if N-acetylcysteine modulates the development of nicotine place conditioning and withdrawal in mice. METHODS: N-acetylcysteine was given to nicotine-treated male ICR mice. Experiment 1: reward-like behavior. N-acetylcysteine (0, 5, 15, 30, or 60 mg/kg, i.p.) was given 15 min before nicotine (0.5 mg/kg, s.c.) or saline (10 ml/kg, s.c.) in an unbiased conditioned place preference (CPP) paradigm. Conditioning for highly palatable food served as control. Experiment 2: spontaneous withdrawal. The effect of N-acetylcysteine (0, 15, 30, 120 mg/kg, i.p.) on anxiety-like behavior, somatic signs, and hyperalgesia was measured 18-24 h after continuous nicotine (24 mg/kg/day, 14 days). Experiment 3: mecamylamine-precipitated, withdrawal-induced aversion. The effect of N-acetylcysteine (0, 15, 30, 120 mg/kg, i.p.) on mecamylamine (3.5 mg/kg, i.p.)-precipitated withdrawal was determined after continuous nicotine (24 mg/kg, i.p., 28 days) using the conditioned place aversion (CPA) paradigm. RESULTS: Dose-related reductions in the development of nicotine CPP, somatic withdrawal signs, hyperalgesia, and CPA were observed after N-acetylcysteine pretreatment. No effect of N-acetylcysteine was found on palatable food CPP, anxiety-like behavior, or motoric capacity (crosses between plus maze arms). Finally, N-acetylcysteine did not affect any measure in saline-treated mice at doses effective in nicotine-treated mice. CONCLUSIONS: These are the first data suggesting that N-acetylcysteine blocks specific mouse behaviors associated with nicotine reward and withdrawal, which adds to the growing appreciation that N-acetylcysteine may have high clinical utility in combating nicotine dependence.
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Acetilcisteína/farmacologia , Aprendizagem por Associação/efeitos dos fármacos , Nicotina/efeitos adversos , Recompensa , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Acetilcisteína/uso terapêutico , Animais , Relação Dose-Resposta a Droga , Masculino , Mecamilamina/farmacologia , Camundongos , Camundongos Endogâmicos ICR , Tabagismo/tratamento farmacológicoRESUMO
Cross-sex hormone treatment of transsexual people may be associated with the induction and growth stimulation of hormone-related malignancies. We report here five cases of breast cancer, three in female-to-male (FtoM) transsexual subjects and two in male-to-female (MtoF) transsexual subjects. In the general population the incidence of breast cancer increases with age and with duration of exposure to sex hormones. This pattern was not recognised in these five transsexual subjects. Tumours occurred at a relatively young age (respectively, 48, 41, 41, 52 and 46 years old) and mostly after a relatively short span of time of cross-sex hormone treatment (9, 9-10 but in one after 30 years). Occurrence of breast cancer was rare. As has been reported earlier, breast tumours may occur in residual mammary tissue after breast ablation in FtoM transsexual people. For adequate treatment and decisions on further cross-sex hormone treatment it is important to have information on the staging and histology of the breast tumour (type, grade and receptor status), with an upcoming role for the androgen receptor status, especially in FtoM transsexual subjects with breast cancer who receive testosterone administration. This information should be taken into account when considering further cross-sex hormone treatment.
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Neoplasias da Mama/epidemiologia , Pessoas Transgênero , Adulto , Neoplasias da Mama/etiologia , Feminino , Hormônios Esteroides Gonadais/efeitos adversos , Hormônios Esteroides Gonadais/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos de Readequação Sexual/efeitos adversosRESUMO
Mesolimbic α6* nicotinic acetylcholine receptors (nAChRs) are thought to have an important role in nicotine behavioral effects. However, little is known about the role of the various α6*-nAChRs subtypes in the rewarding effects of nicotine. In this report, we investigated and compared the role of α6*-nAChRs subtypes and their neuro-anatomical locus in nicotine and cocaine reward-like effects in the conditioned place preference (CPP) paradigm, using pharmacological antagonism of α6ß2* nAChRs and genetic deletion of the α6 or α4 subunits in mice. We found that α6 KO mice exhibited a rightward shift in the nicotine dose-response curve compared with WT littermates but that α4 KO failed to show nicotine preference, suggesting that α6α4ß2*-nAChRs are involved. Furthermore, α6ß2* nAChRs in nucleus accumbens were found to have an important role in nicotine-conditioned reward as the intra-accumbal injection of the selective α6ß2* α-conotoxin MII [H9A; L15A], blocked nicotine CPP. In contrast to nicotine, α6 KO failed to condition to cocaine, but cocaine CPP in the α4 KO was preserved. Intriguingly, α-conotoxin MII [H9A; L15A], blocked cocaine conditioning in α4 KO mice, implicating α6ß2* nAChRs in cocaine reward. Importantly, these effects did not generalize as α6 KO showed both a conditioned place aversion to lithium chloride as well as CPP to palatable food. Finally, dopamine uptake was not different between the α6 KO or WT mice. These data illustrate that the subjective rewarding effects of both nicotine and cocaine may be mediated by mesolimbic α6ß2* nAChRs and that antagonists of these receptor subtypes may exhibit therapeutic potential.
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Cocaína/farmacologia , Inibidores da Captação de Dopamina/farmacologia , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Receptores Nicotínicos/metabolismo , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Aprendizagem da Esquiva/fisiologia , Condicionamento Psicológico/efeitos dos fármacos , Condicionamento Psicológico/fisiologia , Conotoxinas/farmacologia , Dopamina/metabolismo , Relação Dose-Resposta a Droga , Alimentos , Cloreto de Lítio/administração & dosagem , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Antagonistas Nicotínicos/farmacologia , Recompensa , Comportamento Espacial/efeitos dos fármacos , Comportamento Espacial/fisiologiaRESUMO
RATIONALE: Several studies suggest that repeated nicotine administration causes alterations in glutaminergic transmission that may play an important role in developing and maintaining nicotine addiction. Chronic nicotine administration in rats decreases the expression of the glutamate transporter-1 (GLT-1) and cysteine-glutamate exchanger (system xC-) in the nucleus accumbens. We hypothesized that ceftriaxone, a GLT-1 and system xC- activator, would decrease murine behavioral aspects of nicotine dependence. OBJECTIVE: This study aimed to investigate the effect of repeated ceftriaxone administration on the behavioral effects of nicotine using mouse models of conditioned reward and withdrawal. METHOD: Using male ICR mice, the ability of repeated ceftriaxone injections to modulate the development and reinstatement of a nicotine-conditioned place preference (CPP) was evaluated. Additionally, nicotine withdrawal-associated signs were assessed. These included both physical (somatic signs and hyperalgesia) and affective (anxiety-related behaviors) withdrawal signs in mice. Finally, the effects of ceftriaxone on nicotine-induced antinociception and hypothermia after acute nicotine injection were measured. RESULT: Ceftriaxone had no effect on the development of nicotine preference but significantly attenuated nicotine-induced reinstatement of CPP. Furthermore, ceftriaxone reversed all nicotine withdrawal signs measured in mice. CONCLUSION: Altogether, these findings show that a ß-lactam antibiotic reduces nicotine withdrawal and nicotine-seeking behavior. Our results suggest that the documented efficacy of ceftriaxone against cocaine and morphine dependence-related behaviors effects extends to nicotine.
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Antibacterianos/farmacologia , Ceftriaxona/farmacologia , Nicotina/efeitos adversos , Reforço Psicológico , Síndrome de Abstinência a Substâncias/prevenção & controle , Tabagismo/psicologia , Sistemas de Transporte de Aminoácidos/agonistas , Sistemas de Transporte de Aminoácidos/antagonistas & inibidores , Animais , Antibacterianos/uso terapêutico , Ceftriaxona/uso terapêutico , Condicionamento Psicológico/efeitos dos fármacos , Cisteína/metabolismo , Transportador 2 de Aminoácido Excitatório/agonistas , Transportador 2 de Aminoácido Excitatório/antagonistas & inibidores , Extinção Psicológica , Ácido Glutâmico/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Recompensa , Síndrome de Abstinência a Substâncias/metabolismo , Síndrome de Abstinência a Substâncias/psicologia , Tabagismo/metabolismoRESUMO
BACKGROUND: Environmental tobacco smoke (ETS) exposure is linked to developmental deficits and disorders with known cerebellar involvement. However, direct biological effects and underlying neurochemical mechanisms remain unclear. OBJECTIVES: We sought to identify and evaluate underlying neurochemical change in the rat cerebellum with ETS exposure during critical period development. METHODS: We exposed rats to daily ETS (300, 100, and 0 µg/m3 total suspended particulate) from postnatal day 8 (PD8) to PD23 and then assayed the response at the behavioral, neuroproteomic, and cellular levels. RESULTS: Postnatal ETS exposure induced heightened locomotor response in a novel environment on par initially with amphetamine stimulation. The cerebellar mitochondrial subproteome was significantly perturbed in the ETS-exposed rats. Findings revealed a dose-dependent up-regulation of aerobic processes through the modification and increased translocation of Hk1 to the mitochondrion with corresponding heightened ATP synthase expression. ETS exposure also induced a dose-dependent increase in total Dnm1l mitochondrial fission factor; although more active membrane-bound Dnm1l was found at the lower dose. Dnm1l activation was associated with greater mitochondrial staining, particularly in the molecular layer, which was independent of stress-induced Bcl-2 family dynamics. Further, electron microscopy associated Dnm1l-mediated mitochondrial fission with increased biogenesis, rather than fragmentation. CONCLUSIONS: The critical postnatal period of cerebellar development is vulnerable to the effects of ETS exposure, resulting in altered behavior. The biological effect of ETS is underlain in part by a Dnm1l-mediated mitochondrial energetic response at a time of normally tight control. These findings represent a novel mechanism by which environmental exposure can impact neurodevelopment and function.
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Poluentes Atmosféricos/toxicidade , Cerebelo/efeitos dos fármacos , Exposição Ambiental , Mitocôndrias/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Poluição por Fumaça de Tabaco/efeitos adversos , Animais , Animais Recém-Nascidos , Cerebelo/crescimento & desenvolvimento , Cerebelo/fisiologia , Cromatografia Líquida , Relação Dose-Resposta a Droga , Dinaminas/metabolismo , Hexoquinase/metabolismo , Immunoblotting , Masculino , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Mitocôndrias/fisiologia , Dinâmica Mitocondrial/efeitos dos fármacos , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Proteoma/metabolismo , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em TandemRESUMO
Herbivores with polyphagous feeding habits must cope with a diet that varies in quality. One of the most important sources of this variation in host plant suitability is plant secondary chemistry. We examined how feeding on plants containing one such group of compounds, the iridoid glycosides, might affect the growth and enzymatic activity in a polyphagous caterpillar that feeds on over 80 plant species in 50 different families. Larvae of the polyphagous arctiid, Grammia incorrupta, were reared exclusively on one of two plant species, one of which contains iridoid glycosides (Plantago lanceolata, Plantaginaceae) while the other does not (Taraxacum officinale, Asteraceae). Larval weight was measured on the two host plants, and midgut homogenates of last instar larvae were then assayed for activity and kinetic properties of ß-glucosidases, using both a standard substrate, 4-nitrophenyl-ß-D-glucose (NPßGlc), and the iridoid glycoside aucubin, one of the two main iridoid glycosides in P. lanceolata. Larvae feeding on P. lanceolata weighed significantly less and developed more slowly compared to larvae on T. officinale. While the larval midgut ß-glucosidase activity determined with NPßGlc was significantly decreased when fed on P. lanceolata, aucubin was substantially hydrolyzed and the larval ß-glucosidase activity towards both substrates correlated negatively with larval weight. Our results demonstrate that host plants containing high concentrations of iridoid glycosides have a negative impact on larval development of this generalist insect herbivore. This is most likely due to the hydrolysis of plant glycosides in the larval midgut which results in the release of toxic aglycones. Linking the reduced larval weight to the toxin-releasing action of an iridoid glycoside cleaving ß-glucosidase, our results thus support the detoxification limitation hypothesis, suggesting fitness costs for the larvae feeding solely on P. lanceolata. Thus, in addition to the adaptive regulation of midgut ß-glucosidase activity, host plant switching as a behavioral adaptation might be a prerequisite for generalist herbivores that allows them to circumvent the negative effects of plant secondary compounds.
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Interações Hospedeiro-Parasita , Glicosídeos Iridoides/metabolismo , Mariposas/enzimologia , beta-Glucosidase/metabolismo , Animais , Feminino , Trato Gastrointestinal/enzimologia , Glucosídeos/metabolismo , Herbivoria , Glucosídeos Iridoides/metabolismo , Larva/enzimologia , Larva/crescimento & desenvolvimento , Mariposas/crescimento & desenvolvimento , Plantago/química , Plantago/parasitologia , Taraxacum/química , Taraxacum/parasitologiaRESUMO
This study compared different methods of tissue preparation for extraction of iridoid glycosides sequestered by three species of lepidopteran larvae. Junonia coenia is a specialist on plant species that produce iridoid glycosides, while the arctiids Estigmene acrea and Spilosoma congrua are both polyphagous and will eat plants that produce iridoid glycosides. Larvae of all three species were reared on leaves of Plantago lanceolata, which produces two primary iridoid glycosides, aucubin and catalpol. Three methods of preparing the specimens before extraction in methanol were compared in all three species: 1) larvae were flash-frozen in liquid nitrogen, 2) larvae were macerated fresh in boiling methanol, or 3) larvae were macerated fresh in room temperature methanol. A set of J. coenia larvae was oven-dried before maceration as an additional treatment for this species only. Junonia coenia sequestered the most iridoid glycosides, while E. acrea sequestered the least, and S. congrua was intermediate. Estigmene acrea was poor at sequestering catalpol. Tissue preparation method only significantly influenced iridoid glycoside recovery from S. congrua, with maceration in room-temperature methanol being the most effective of the three methods. This study shows that treatment of insects prior to iridoid glycoside extraction can influence recovery of the compounds, and that the effects of treatment may vary among different species.
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Glicosídeos Iridoides/isolamento & purificação , Larva/química , Lepidópteros/química , Animais , Folhas de Planta/parasitologia , Plantago/parasitologiaRESUMO
We considered the effects of plant secondary metabolites on the immune response, a key physiological defense of herbivores against pathogens and parasitoids. We tested the effect of host plant species and ingested iridoid glycosides on the immune response of the grazing, polyphagous caterpillar, Grammia incorrupta (Arctiidae). Individuals of G. incorrupta were fed either one of three plant diets with varying secondary metabolites, or an artificial diet with high or low concentrations of iridoid glycosides. An immune challenge was presented, followed by measurement of the encapsulation response. We failed to detect a significant difference in the immune response of G. incorrupta feeding on diets with varying concentrations of iridoid glycosides, or feeding on different host plants. However, the immune response was lower in caterpillars consuming the artificial diet compared to those consuming the plant diets. When caterpillar performance was measured, pupal weights were lower when caterpillars ingested high concentrations of iridoid glycosides due to a decrease in feeding efficiency. Overall, individuals of G. incorrupta that consumed different plant diets exhibited a high immune response with low variation. We conclude that the immune response of G. incorrupta is adapted to feeding on a variety of plants, which may contribute to the maintenance of this caterpillar's polyphagous habit.
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Borboletas/imunologia , Glicosídeos Iridoides/farmacologia , Adaptação Fisiológica , Animais , Borboletas/crescimento & desenvolvimento , Comportamento Alimentar , Larva/imunologia , Larva/fisiologia , Melaninas/metabolismo , Folhas de Planta/química , Plantago/químicaRESUMO
We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 µm diameter hot core.
RESUMO
The effect of diet on sequestration of iridoid glycosides was examined in larvae of three lepidopteran species. Larvae were reared upon Plantago major, or P. lanceolata, or switched from one to the other in the penultimate instar. Junonia coenia is a specialist on iridoid glycoside-producing plants, whereas the arctiids, Spilosoma congrua and Estigmene acrea, are both polyphagous and eat iridoid-producing plants. All species sequestered iridoids. The specialist J. coenia sequestered from three to seven times the amounts sequestered by the two generalist species. Junonia coenia iridoid glycoside content depended on diet, and they sequestered from 5 to 15% dry weight iridoid glycosides. Estigmene acrea iridoid glycoside sequestration was relatively low, around 2% dry weight and did not vary with diet. Spilosoma congrua sequestration varied with diet and ranged from approximately 3 to 6% dry weight.
Assuntos
Comportamento Alimentar/efeitos dos fármacos , Glicosídeos Iridoides/farmacologia , Lepidópteros/efeitos dos fármacos , Plantago/efeitos dos fármacos , Animais , Comportamento Alimentar/fisiologia , Interações Hospedeiro-Parasita , Larva/efeitos dos fármacos , Larva/fisiologia , Lepidópteros/química , Lepidópteros/classificação , Lepidópteros/fisiologia , Plantago/química , Plantago/fisiologia , Plantas Comestíveis , Especificidade da EspécieRESUMO
Iridoid glycosides are secondary plant compounds that have deterrent, growth reducing or even toxic effects on non-adapted herbivorous insects. To investigate the effects of iridoid glycoside containing plants on the digestive metabolism of a generalist herbivore, larvae of Spilosoma virginica (Lepidoptera: Arctiidae) were reared on three plant species that differ in their secondary plant chemistry: Taraxacum officinale (no iridoid glycosides), Plantago major (low iridoid glycoside content), and P. lanceolata (high iridoid glycoside content). Midguts of fifth instar larvae were assayed for the activity and kinetic properties of ß-glucosidase using different substrates. Compared to the larvae on T. officinale, the ß-glucosidase activity of larvae feeding on P. lanceolata was significantly lower measured with 4-nitrophenyl-ß-d-glucopyranoside. Using the iridoid glycoside aucubin as a substrate, we did not find differences in the ß-glucosidase activity of the larvae reared on the three plants. Heat inactivation experiments revealed the existence of a heat-labile and a more heat-stable ß-glucosidase with similar Michaelis constants for 4-nitrophenyl-ß-d-glucopyranoside. We discuss possible mechanisms leading to the observed decrease of ß-glucosidase activity for larvae reared on P. lanceolata and its relevance for generalist herbivores in adapting to iridoid glycoside containing plant species and their use as potential host plants.
Assuntos
Sistema Digestório/metabolismo , Glicosídeos Iridoides/metabolismo , Lepidópteros/enzimologia , Plantago/química , beta-Glucosidase/metabolismo , Animais , Sistema Digestório/enzimologia , Cinética , Larva/enzimologia , Estatísticas não ParamétricasRESUMO
OBJECTIVE: To test the hypothesis that replacing the antiscatter grid with an air gap will reduce patient radiation exposure without significant compromise of image quality. METHODS: 457 patients having either uncomplicated diagnostic studies or a single vessel angioplasty (percutaneous transluminal coronary angioplasty (PTCA)) on a flat plate system (GE Innova) were studied. For two months their total dose-area product score was recorded on standard gridded images and then for two months on images made with the grid out, with an air gap used to reduce scatter. Detector magnification was reduced one step when an air gap was used to achieve the same final image size. A sample set of studies was reviewed blind by five observers, who scored sharpness and contrast on a non-linear scale. RESULTS: The average dose-area product was significantly reduced, both in the diagnostic group (n = 276), from a mean (SD) of 26.2 (14.7) Gy.cm2 with the grid in to 16.1 (12) Gy.cm2 with the grid out (p = 0.01), and in the PTCA group (n = 181), from 48.2 (36.2) to 37 (27.5) (p = 0.01). The mean image quality scores of the gridless cohort were not significantly different from those of the gridded cohort. CONCLUSION: With the use of a flat plate detector, air gap gridless angiography reduces the radiation dose to the patient and, in consequence, to the operator without significantly affecting image quality. It is proposed that gridless imaging should be the default technique for adults and children and in most installations.