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1.
Behav Sci (Basel) ; 13(9)2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37754044

RESUMO

Although preoperative anxiety affects up to 75% of children undergoing surgery each year and is associated with many adverse outcomes, we know relatively little about individual differences in how children respond to impending surgery. We examined whether patterns of anterior brain electrical activity (i.e., a neural correlate of anxious arousal) moderated the relation between children's shyness and preoperative anxiety on the day of surgery in 70 children (36 girls, Mage = 10.4 years, SDage = 1.7, years, range 8 to 13 years) undergoing elective surgery. Shyness was assessed using self-report approximately 1 week prior to surgery during a preoperative visit (Time 1), preoperative anxiety was assessed using self-report, and regional EEG (left and right frontal and temporal sites) was assessed using a dry sensory EEG headband on the day of surgery (Time 2). We found that overall frontal EEG alpha power moderated the relation between shyness and self-reported preoperative anxiety. Shyness was related to higher levels of self-reported anxiety on the day of surgery for children with lower average overall frontal alpha EEG power (i.e., higher cortical activity) but not for children with higher average overall frontal alpha EEG power (i.e., lower cortical activity). These results suggest that the pattern of frontal brain activity might amplify some shy children's affective responses to impending surgery. Findings also extend prior results linking children's shyness, frontal brain activity, and anxiety observed in the laboratory to a real-world, ecologically salient environment.

3.
eNeuro ; 3(6)2016.
Artigo em Inglês | MEDLINE | ID: mdl-27957533

RESUMO

For decades, electroencephalography (EEG) has been a useful tool for investigating the neural mechanisms underlying human psychological processes. However, the amount of time needed to gather EEG data means that most laboratory studies use relatively small sample sizes. Using the Muse, a portable and wireless four-channel EEG headband, we obtained EEG recordings from 6029 subjects 18-88 years in age while they completed a category exemplar task followed by a meditation exercise. Here, we report age-related changes in EEG power at a fine chronological scale for δ, θ, α, and ß bands, as well as peak α frequency and α asymmetry measures for both frontal and temporoparietal sites. We found that EEG power changed as a function of age, and that the age-related changes depended on sex and frequency band. We found an overall age-related shift in band power from lower to higher frequencies, especially for females. We also found a gradual, year-by-year slowing of the peak α frequency with increasing age. Finally, our analysis of α asymmetry revealed greater relative right frontal activity. Our results replicate several previous age- and sex-related findings and show how some previously observed changes during childhood extend throughout the lifespan. Unlike previous age-related EEG studies that were limited by sample size and restricted age ranges, our work highlights the advantage of using large, representative samples to address questions about developmental brain changes. We discuss our findings in terms of their relevance to attentional processes and brain-based models of emotional well-being and aging.


Assuntos
Envelhecimento/fisiologia , Encéfalo/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Ondas Encefálicas/fisiologia , Eletroencefalografia/instrumentação , Feminino , Humanos , Julgamento/fisiologia , Masculino , Meditação , Pessoa de Meia-Idade , Atenção Plena , Testes Neuropsicológicos , Caracteres Sexuais , Processamento de Sinais Assistido por Computador , Adulto Jovem
4.
BMC Psychol ; 4(1): 60, 2016 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-27894358

RESUMO

BACKGROUND: Mindfulness training (MT) programs represent an approach to attention training with well-validated mental health benefits. However, research supporting MT efficacy is based predominantly on weekly-meeting, facilitator-led, group-intervention formats. It is unknown whether participants might benefit from neurofeedback-assisted, technology-supported MT (N-tsMT), in which meditation is delivered individually, without the need for a facilitator, travel to a training site, or the presence of a supportive group environment. Mirroring the validation of group MT interventions, the first step in addressing this question requires identifying whether N-tsMT promotes measurable benefits. Here, we report on an initial investigation of a commercial N-tsMT system. METHODS: In a randomized, active control trial, community-dwelling healthy adult participants carried out 6 weeks of daily practice, receiving either N-tsMT (n = 13), or a control condition of daily online math training (n = 13). Training effects were assessed on target measures of attention and well-being. Participants also completed daily post-training surveys assessing effects on mood, body awareness, calm, effort, and stress. RESULTS: Analysis revealed training effects specific to N-tsMT, with attentional improvements in overall reaction time on a Stroop task, and well-being improvements via reduced somatic symptoms on the Brief Symptom Inventory. Attention and well-being improvements were correlated, and effects were greatest for the most neurotic participants. However, secondary, exploratory measures of attention and well-being did not show training-specific effects. N-tsMT was associated with greater body awareness and calm, and initially greater effort that later converged with effort in the control condition. CONCLUSIONS: Preliminary findings indicate that N-tsMT promotes modest benefits for attention and subjective well-being in a healthy community sample relative to an active control condition. However, the findings would benefit from replication in a larger sample, and more intensive practice or more comprehensive MT instruction might be required to promote the broader benefits typically reported in group format, facilitated MT. TRIAL REGISTRATION: Current Controlled Trials ISRCTN43629398 . Retrospectively registered on June 16, 2016.


Assuntos
Afeto , Atenção , Eletroencefalografia , Atenção Plena/instrumentação , Atenção Plena/métodos , Neurorretroalimentação/instrumentação , Neurorretroalimentação/métodos , Adulto , Feminino , Humanos , Masculino , Qualidade de Vida , Tempo de Reação , Estresse Psicológico/prevenção & controle , Teste de Stroop , Resultado do Tratamento
5.
Reprod Toxicol ; 59: 22-30, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26854737

RESUMO

Small molecule pharmaceutical products are assumed to reach concentrations in semen similar to those in blood plasma. Exposure modeling for these small-molecule products in humans assumes a daily dose of 5mL of semen and 100% absorption from the vagina with distribution to the conceptus through the maternal systemic circulation. Monoclonal antibody drugs are present in semen at concentrations about 2% or less of those in blood, and the modeling used for small molecules will over-estimate the possibility of conceptus exposure to immunoglobulins. It is not known whether peptide products reach semen, but in general peptide medications are destroyed by vaginal peptidases, and conceptus exposure is predicted to be minimal. Theoretical exposure routes to pharmaceuticals that might result in exposure of the conceptus greater than that of maternal systemic exposures include direct access through the cervical canal, adsorption to sperm for carriage into the oocyte, and direct delivery from the vaginal veins or lymphatics to the uterine artery. There is some evidence for direct access to the uterus for progesterone, terbutaline, and danazol, but the evidence does not involve exposures during pregnancy in most instances. Studies in mice, rats, rabbits, and monkeys do not suggest that exposure to small molecule pharmaceuticals in semen imposes risks to the conceptus beyond those that can be predicted using modeling of systemic maternal exposure. Monoclonal antibody and peptide exposure in semen does not pose a significant risk to the conceptus.


Assuntos
Anticorpos Monoclonais/metabolismo , Embrião de Mamíferos/metabolismo , Feto/metabolismo , Peptídeos/metabolismo , Preparações Farmacêuticas/metabolismo , Sêmen/metabolismo , Vagina/metabolismo , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/química , Anticorpos Monoclonais/toxicidade , Transporte Biológico , Embrião de Mamíferos/efeitos dos fármacos , Feminino , Feto/efeitos dos fármacos , Haplorrinos , Humanos , Masculino , Exposição Materna , Camundongos , Modelos Animais , Modelos Biológicos , Exposição Paterna , Peptídeos/química , Peptídeos/toxicidade , Permeabilidade , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/química , Coelhos , Medição de Risco , Absorção Vaginal
6.
Reprod Toxicol ; 59: 17-21, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26524246

RESUMO

Given concern about potential embryo-fetal harm following seminal exposure to drugs with teratogenic potential, pharmaceutical companies use theoretical calculations to estimate seminal concentrations, maternal exposure, and distribution across the placenta to the embryo-fetal compartment for risk assessment. However, it is plausible that there are additional mechanisms whereby the conceptus is exposed. In order to determine if theoretical calculations are sufficiently conservative to predict embryo-fetal exposure from drugs in semen, pregnant cynomolgus monkeys were given a vaginal dose of metronidazole during the early fetal period and cesarean-sectioned. Maternal, fetal, and amniotic fluid samples were analyzed for metronidazole and 2-hydroxymetronidazole. Exposure to metronidazole and its metabolite were comparable in all matrices. These data demonstrated no preferential transfer mechanism to conceptus following intravaginal administration of a small molecule drug; and therefore, suggest that traditional modeling for embryo-fetal exposure to drugs in semen in support of risk assessment for pharmaceutical agents is sufficiently conservative.


Assuntos
Líquido Amniótico/metabolismo , Anti-Infecciosos/administração & dosagem , Feto/metabolismo , Exposição Materna , Metronidazol/administração & dosagem , Vagina/metabolismo , Administração Intravaginal , Animais , Anti-Infecciosos/sangue , Anti-Infecciosos/toxicidade , Biotransformação , Feminino , Feto/efeitos dos fármacos , Macaca fascicularis , Exposição Materna/efeitos adversos , Metronidazol/análogos & derivados , Metronidazol/sangue , Metronidazol/metabolismo , Metronidazol/toxicidade , Permeabilidade , Gravidez , Medição de Risco
7.
Br J Clin Pharmacol ; 81(2): 362-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26447647

RESUMO

AIMS: Denosumab is a fully human monoclonal immunoglobulin G2 antibody that inhibits bone resorption and increases bone mass and strength. The present clinical study assessed serum and seminal fluid pharmacokinetics following a single denosumab dose in healthy men, and evaluated whether denosumab in seminal fluid poses any risk to a fetus in the event of unprotected sexual intercourse with a pregnant partner. METHODS: An open-label, single-dose study in 12 healthy men was conducted over a 106-day period. Subjects received a single subcutaneous dose of 60-mg denosumab on day 1. Serum and seminal fluid samples were collected at specified time points to assess denosumab pharmacokinetics. Adverse events were recorded. RESULTS: Denosumab was measurable at low concentrations in seminal fluid (~2% of serum concentrations). The mean [standard deviation (SD)] maximum observed drug concentration (Cmax ) was 6170 (2070) ng ml(-1) (serum) and 100 (81.9) ng ml(-1) (seminal fluid). The median time to Cmax (tmax ) was 8 days (serum) and 21 days (seminal fluid). The mean (SD) area under the plasma concentration-time curve (AUC) from time zero to the time of the last quantifiable concentration (AUClast ) was 333 000 (122 000) day•ng ml(-1) (serum) and 5220 (4880) day•ng ml(-1) (seminal fluid). The mean (SD) Cmax and AUC ratios between seminal fluid and serum were 0.0217 (0.0154) and 0.0170 (0.0148), respectively. Using conservative assumptions for ejaculate volume (6 ml), vaginal absorption (100%) and placental transfer (100%), the measured mean denosumab seminal fluid Cmax would result in fetal exposure that was more than 110 times below the preclinically derived 'no effect level' for denosumab. CONCLUSIONS: These results indicate a negligible risk to a fetus exposed to denosumab via seminal fluid transfer to a pregnant partner.


Assuntos
Conservadores da Densidade Óssea/farmacocinética , Denosumab/farmacocinética , Troca Materno-Fetal , Sêmen/metabolismo , Vagina/metabolismo , Adulto , Idoso , Conservadores da Densidade Óssea/administração & dosagem , Conservadores da Densidade Óssea/sangue , Denosumab/administração & dosagem , Denosumab/sangue , Feminino , Voluntários Saudáveis , Humanos , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Gravidez , Risco
8.
Reprod Toxicol ; 58: 213-21, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26545974

RESUMO

Small molecule pharmaceutical products are assumed to reach concentrations in semen similar to those in blood plasma. Exposure modeling for these small-molecule products in humans assumes a daily dose of 5mL of semen and 100% absorption from the vagina with distribution to the conceptus through the maternal systemic circulation. Monoclonal antibody drugs are present in semen at concentrations about 2% or less of those in blood, and the modeling used for small molecules will over-estimate the possibility of conceptus exposure to immunoglobulins. It is not known whether peptide products reach semen, but in general peptide medications are destroyed by vaginal peptidases, and conceptus exposure is predicted to be minimal. Theoretical exposure routes to pharmaceuticals that might result in exposure of the conceptus greater than that of maternal systemic exposures include direct access through the cervical canal, adsorption to sperm for carriage into the oocyte, and direct delivery from the vaginal veins or lymphatics to the uterine artery. There is some evidence for direct access to the uterus for progesterone, terbutaline, and danazol, but the evidence does not involve exposures during pregnancy in most instances. Studies in mice, rats, rabbits, and monkeys do not suggest that exposure to small molecule pharmaceuticals in semen imposes risks to the conceptus beyond those that can be predicted using modeling of systemic maternal exposure. Monoclonal antibody and peptide exposure in semen does not pose a significant risk to the conceptus.


Assuntos
Anticorpos Monoclonais/metabolismo , Colo do Útero/metabolismo , Embrião de Mamíferos/metabolismo , Preparações Farmacêuticas/metabolismo , Proteínas/metabolismo , Sêmen/metabolismo , Vagina/metabolismo , Animais , Anticorpos Monoclonais/efeitos adversos , Transporte Biológico , Colo do Útero/efeitos dos fármacos , Embrião de Mamíferos/efeitos dos fármacos , Feminino , Humanos , Masculino , Modelos Biológicos , Gravidez , Proteínas/efeitos adversos , Medição de Risco , Fatores de Risco , Especificidade da Espécie , Vagina/efeitos dos fármacos
9.
Front Psychol ; 6: 903, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26191019

RESUMO

It is well known that, although psychophysical scaling produces good qualitative agreement between experiments, precise quantitative agreement between experimental results, such as that routinely achieved in physics or biology, is rarely or never attained. A particularly galling example of this is the fact that power function exponents for the same psychological continuum, measured in different laboratories but ostensibly using the same scaling method, magnitude estimation, can vary by a factor of three. Constrained scaling (CS), in which observers first learn a standardized meaning for a set of numerical responses relative to a standard sensory continuum and then make magnitude judgments of other sensations using the learned response scale, has produced excellent quantitative agreement between individual observers' psychophysical functions. Theoretically it could do the same for across-laboratory comparisons, although this needs to be tested directly. We compared nine different experiments from four different laboratories as an example of the level of across experiment and across-laboratory agreement achievable using CS. In general, we found across experiment and across-laboratory agreement using CS to be significantly superior to that typically obtained with conventional magnitude estimation techniques, although some of its potential remains to be realized.

10.
Reprod Toxicol ; 48: 132-7, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24859271

RESUMO

To assess the potential for male-mediated drug transfer to their female partner and/or developing conceptus, vaginal uptake of a monoclonal antibody (mAb) biotherapeutic was assessed in cynomolgus monkeys. A human IgG2 mAb (IgG2X; bound human and cynomolgus monkey neonatal Fc-receptor, FcRn, with similar high affinity) was administered intravaginally (IvG; 100mg/dose) to 5 pregnant cynomolgus monkeys biweekly from gestation day (gd) 21 to gd133. In all maternal samples collected before gd119, IgG2X plasma concentrations were below the limit of quantification (BLQ; <25ng/mL). After dosing on gd119 and 133, maternal IgG2X plasma concentrations remained BLQ in 3/5 monkeys and were very low in 2/5 (up to 116ng/mL; ∼0.01% of the IvG dose). IgG2X was BLQ in all fetal plasma samples. These data indicate that male-mediated mAb drug transfer via seminal fluid does not present a health risk to the female partner and is not bioavailable to the developing conceptus.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/farmacocinética , Sangue Fetal/metabolismo , Imunoglobulina G/administração & dosagem , Imunoglobulina G/farmacologia , Administração Intravaginal , Animais , Anticorpos Monoclonais/sangue , Feminino , Imunoglobulina G/sangue , Macaca fascicularis , Masculino , Exposição Materna , Troca Materno-Fetal , Gravidez , Sêmen/metabolismo
12.
Birth Defects Res B Dev Reprod Toxicol ; 101(2): 178-88, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24753333

RESUMO

Understanding species differences in the placental transfer of monoclonal antibodies is important to inform species selection for nonclinical safety assessment, interpret embryo-fetal changes observed in these studies, and extrapolate their human relevance. Data presented here for a fully human immunoglobulin G2 monoclonal antibody (IgG2X) revealed that, during organogenesis, in both the cynomolgus monkey (gestation day 35 [gd35]) and the rat (gd10) the extent of IgG2X placental transfer (approximately 0.5% maternal plasma concentration, MPC) was similar to the limited published human data for endogenous IgG. At this early gestational stage, IgG2X placental transfer was approximately 6-fold higher in the rabbit (gd10). By the end of organogenesis, rat embryonic plasma concentrations (gd16) exceeded those in the cynomolgus monkey (gd50) by approximately 3-fold. These data suggest that relative to the cynomolgus monkey, the rabbit (and to a lesser extent the rat) may overestimate potential harmful effects to the human embryo during this critical period of development. Beyond organogenesis, fetal IgG2X plasma concentrations increased approximately 10-fold early in the second trimester (gd50-70) in the cynomolgus monkey and remained relatively unchanged thereafter (at approximately 5% MPC). Late gestational assessment was precluded in rabbits due to immunogenicity, but in rats, fetal IgG2X plasma concentrations increased more than 6-fold from gd16 to gd21 (reaching approximately 15% MPC). In rats, maternal exposure consistent with that achieved by ICH S6(R1) high-dose selection criteria resulted in embryonic plasma concentrations, reaching pharmacologically relevant levels during organogenesis. Furthermore, dose proportional exposure in both mothers and embryos indicated that this was unlikely to occur at the lower therapeutic dose levels used in humans.


Assuntos
Anticorpos Monoclonais/farmacocinética , Troca Materno-Fetal , Organogênese/efeitos dos fármacos , Placenta/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Embrião de Mamíferos/efeitos dos fármacos , Feminino , Feto/efeitos dos fármacos , Feto/embriologia , Idade Gestacional , Imunoglobulina G/metabolismo , Macaca fascicularis , Exposição Materna , Placenta/metabolismo , Gravidez , Coelhos , Ratos , Ratos Sprague-Dawley
13.
Regul Toxicol Pharmacol ; 66(3): 269-78, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23680404

RESUMO

According to ICH S6(R1), mating studies are not practical for assessing effects on female fertility of biopharmaceuticals that are pharmacologically active only in non-human primates (NHPs). Instead, fertility should be assessed by evaluating histopathology and organ weights of the reproductive tract in studies of at least 3 months dosing duration using sexually mature NHPs. An assessment of the menstrual cycle in females can be included if there is cause for concern based on pharmacological mode of action or relevant findings in previous studies. However, many factors unrelated to the molecule under evaluation can impact cycle length and thus affect data interpretation. Assessment of a monoclonal antibody in a 6 month repeat dose toxicity study is used as an example in this manuscript to review potential sources of background variability, identify strategies to minimize its impact and recommend optimal ways to collect, present and analyze menstrual cycle data. Experimental variables include the amount of time required for menses to normalize following the transport of animals to the testing facility, stress-related effects on the cycle length due to socialization issues with new cagemates, and the normal background irregularity of cycle length in NHPs. Study related procedures (i.e., animal handling for dosing, blood draws, body weights, ECGs, etc.) did not affect cycle lengths in this study. We show that introducing a number of key experimental control procedures to minimize cycle variability can enable a robust assessment of the effects of a biotherapeutic on menstrual cycling within a chronic toxicity study in NHPs.


Assuntos
Anticorpos Monoclonais Humanizados/toxicidade , Biofarmácia/métodos , Determinação de Ponto Final , Fertilidade/efeitos dos fármacos , Ciclo Menstrual/efeitos dos fármacos , Testes de Toxicidade Subcrônica/métodos , Animais , Biofarmácia/normas , Feminino , Macaca fascicularis , Medição de Risco , Fatores de Tempo , Testes de Toxicidade Subcrônica/normas
14.
Birth Defects Res B Dev Reprod Toxicol ; 98(6): 459-85, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24391099

RESUMO

BACKGROUND: Understanding species differences in placental transfer of Fc-containing biopharmaceuticals (particularly monoclonal antibodies) will improve human risk extrapolation from nonclinical embryo-fetal development toxicity data. METHODS: Maternal and fetal concentration data from 10, 15, 8, and 34 Fc-containing biopharmaceuticals in the rabbit, rat, mouse, and cynomolgus monkey, respectively, from an industry survey were analyzed for trends in placental transfer. RESULTS AND CONCLUSIONS: Embryonic (before the end of organogenesis) exposure was assessed in one molecule each in rabbit, rat, and mouse, but detectable levels were present only in rodents. In rodents, fetal levels remained relatively constant from gestation day (GD) 16 and 17 until the end of gestation, while maternal levels decreased or remained constant in rat and decreased in mice. In rabbits, following a last dose on GD 19, fetal levels increased markedly in late gestation while maternal levels decreased. In the cynomolgus monkey, fetal levels increased substantially from GD 50 to 100 and were maintained relatively constant through parturition (approximately GD 165). Based on available data of both the monkey and rabbit, IgG1 molecules appeared to transfer more readily than other isotypes in late gestation. Across all species, there was no differential transfer based on pharmacologic target being soluble or membrane bound. Within each species there was a correlation between maternal and fetal exposure, suggesting it may be possible to predict fetal exposures from maternal exposure data. These nonclinical data (both temporal and quantitative aspects) are discussed in a comparative context relative to our understanding of IgG placental transfer in humans.


Assuntos
Anticorpos Monoclonais/farmacologia , Fragmentos Fc das Imunoglobulinas/farmacologia , Troca Materno-Fetal , Animais , Anticorpos Monoclonais/sangue , Anticorpos Monoclonais/imunologia , Embrião de Mamíferos/efeitos dos fármacos , Embrião de Mamíferos/imunologia , Feminino , Humanos , Fragmentos Fc das Imunoglobulinas/sangue , Fragmentos Fc das Imunoglobulinas/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Macaca fascicularis , Camundongos , Organogênese , Placenta , Gravidez , Coelhos , Ratos , Especificidade da Espécie
15.
J Assoc Res Otolaryngol ; 9(4): 417-35, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18712566

RESUMO

Animals exposed to noise trauma show augmented synchronous neural activity in tonotopically reorganized primary auditory cortex consequent on hearing loss. Diminished intracortical inhibition in the reorganized region appears to enable synchronous network activity that develops when deafferented neurons begin to respond to input via their lateral connections. In humans with tinnitus accompanied by hearing loss, this process may generate a phantom sound that is perceived in accordance with the location of the affected neurons in the cortical place map. The neural synchrony hypothesis predicts that tinnitus spectra, and heretofore unmeasured "residual inhibition functions" that relate residual tinnitus suppression to the center frequency of masking sounds, should cover the region of hearing loss in the audiogram. We confirmed these predictions in two independent cohorts totaling 90 tinnitus subjects, using computer-based tools designed to assess the psychoacoustic properties of tinnitus. Tinnitus spectra and residual inhibition functions for depth and duration increased with the amount of threshold shift over the region of hearing impairment. Residual inhibition depth was shallower when the masking sounds that were used to induce residual inhibition showed decreased correspondence with the frequency spectrum and bandwidth of the tinnitus. These findings suggest that tinnitus and its suppression in residual inhibition depend on processes that span the region of hearing impairment and not on mechanisms that enhance cortical representations for sound frequencies at the audiometric edge. Hearing thresholds measured in age-matched control subjects without tinnitus implicated hearing loss as a factor in tinnitus, although elevated thresholds alone were not sufficient to cause tinnitus.


Assuntos
Limiar Auditivo/fisiologia , Perda Auditiva Bilateral/fisiopatologia , Perda Auditiva Unilateral/fisiopatologia , Inibição Neural/fisiologia , Zumbido/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Audiometria , Córtex Auditivo/fisiologia , Feminino , Perda Auditiva Bilateral/complicações , Perda Auditiva Bilateral/diagnóstico , Perda Auditiva Unilateral/complicações , Perda Auditiva Unilateral/diagnóstico , Humanos , Percepção Sonora/fisiologia , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Zumbido/complicações , Zumbido/diagnóstico , Adulto Jovem
16.
Acta Otolaryngol Suppl ; (556): 27-33, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17114139

RESUMO

CONCLUSIONS: Psychoacoustic functions relating the depth and duration of tinnitus suppression ('residual inhibition') to the center frequency of band-passed noise masking sounds appear to span the region of hearing loss, as do psychoacoustic measurements of the tinnitus spectrum. The results (1) suggest that cortical map reorganization induced by hearing loss is not the principal source of the tinnitus sensation and (2) provide a necessary baseline for optimizing residual inhibition in individual cases. OBJECTIVE: To measure residual inhibition functions and tinnitus spectra using sounds spanning the region of hearing loss. MATERIALS AND METHODS: Three subject-driven, computer-based tools were developed and applied to measure psychoacoustic properties of tinnitus and residual inhibition in 32 subjects with chronic tonal, ringing, or hissing tinnitus. Residual inhibition functions were measured with band-passed noise sounds varying in center frequency up to 12.0 kHz. RESULTS: The depth and duration of residual inhibition increased with the center frequency of the band-passed noise stimuli. Near-elimination of tinnitus for up to 45 s was reported by 8/24 (33%) subjects at center frequencies above 3 kHz (these cases distributed across tinnitus types). Tinnitus spectra covered the region of hearing loss with no preponderance of frequencies near the audiometric edge of normal hearing.


Assuntos
Limiar Auditivo/fisiologia , Inibição Neural/fisiologia , Zumbido/diagnóstico , Zumbido/fisiopatologia , Adulto , Idoso , Audiometria , Doença Crônica , Diagnóstico por Computador , Feminino , Transtornos da Audição/diagnóstico , Transtornos da Audição/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Ruído , Mascaramento Perceptivo/fisiologia , Percepção da Altura Sonora/fisiologia , Psicoacústica , Índice de Gravidade de Doença , Som , Zumbido/classificação
18.
Biochem J ; 365(Pt 2): 405-16, 2002 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11991805

RESUMO

Mice that lack the Nrf2 basic-region leucine-zipper transcription factor are more sensitive than wild-type (WT) animals to the cytotoxic and genotoxic effects of foreign chemicals and oxidants. To determine the basis for the decrease in tolerance of the Nrf2 homozygous null mice to xenobiotics, enzyme assay, Western blotting and gene-specific real-time PCR (TaqMan) have been used to examine the extent to which hepatic expression of GSH-dependent enzymes is influenced by the transcription factor. The amounts of protein and mRNA for class Alpha, Mu and Pi glutathione S-transferases were compared between WT and Nrf2 knockout (KO) mice of both sexes under both constitutive and inducible conditions. Among the class Alpha and class Mu transferases, constitutive expression of Gsta1, Gsta2, Gstm1, Gstm2, Gstm3, Gstm4 and Gstm6 subunits was reduced in the livers of Nrf2 mutant mice to between 3% and 60% of that observed in WT mice. Induction of these subunits by butylated hydroxyanisole (BHA) was more marked in WT female mice than in WT male mice. TaqMan analyses showed the increase in transferase mRNA caused by BHA was attenuated in Nrf2(-/-) mice, with the effect being most apparent in the case of Gsta1, Gstm1 and Gstm3. Amongst class Pi transferase subunits, the constitutive hepatic level of mRNA for Gstp1 and Gstp2 was not substantially affected in the KO mice, but their induction by BHA was dependent on Nrf2; this was more obvious in female mutant mice than in male mice. Nrf2 KO mice exhibited reduced constitutive expression of the glutamate cysteine ligase catalytic subunit, and, to a lesser extent, the expression of glutamate cysteine ligase modifier subunit. Little variation was observed in the levels of glutathione synthase in the different mouse lines. Thus the increased sensitivity of Nrf2(-/-) mice to xenobiotics can be partly attributed to a loss in constitutive expression of multiple GSH-dependent enzymes, which causes a reduction in intrinsic detoxification capacity in the KO animal. These data also indicate that attenuated induction of GSH-dependent enzymes in Nrf2(-/-) mice probably accounts for their failure to adapt to chronic exposure to chemical and oxidative stress.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Glutationa Transferase/genética , Fígado/enzimologia , Transativadores/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Clonagem Molecular , Primers do DNA , Sondas de DNA , Proteínas de Ligação a DNA/genética , Feminino , Glutationa Transferase/química , Glutationa Transferase/metabolismo , Masculino , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Fator 2 Relacionado a NF-E2 , RNA Mensageiro/genética , Homologia de Sequência de Aminoácidos , Transativadores/genética
19.
Environ Health Perspect ; 110(5): 533-6, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12003759

RESUMO

In this study we found that the ultraviolet sunscreen component 3-(4-methylbenzylidine)camphor (4MBC) is uterotrophic in immature rats when administered by either subcutaneous injection or oral gavage. These data confirm earlier reports of uterotrophic activity for this agent when administered to immature rats in the diet or by whole-body immersion; however, they are in contrast to negative unpublished immature rat uterotrophic assay results. Data also indicate that 4MBC binds to isolated rat uterine estrogen receptors and shows activity in a human estrogen receptor yeast transactivation assay; however, we considered both of these effects equivocal. In this study, we confirmed the original observation that 4MBC was active as a mitogen to MCF-7 breast cancer cells. We evaluated and discounted the possibility that the estrogenic activity of 4MBC is related to its bulky camphor group, which is of similar molecular dimensions to that of the weak estrogen kepone. Uncertainty remains regarding the mechanism of the uterotrophic activity of 4MBC.


Assuntos
Cânfora/efeitos adversos , Divisão Celular/efeitos dos fármacos , Receptores de Estrogênio/efeitos dos fármacos , Protetores Solares/efeitos adversos , Útero/efeitos dos fármacos , Administração Oral , Animais , Cânfora/administração & dosagem , Cânfora/análogos & derivados , Feminino , Injeções Subcutâneas , Ratos , Ratos Wistar , Relação Estrutura-Atividade , Protetores Solares/administração & dosagem , Útero/citologia
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