Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 53
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Craniofac Surg ; 35(4): 1096-1100, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38743277

RESUMO

The purpose of this study is to analyze the angular variations within Cupid's bow in patients with unoperated unilateral cleft lip (UCL). Angular features of Cupid's bow were quantified in standardized presurgical photographs of children with UCL by 5 medical professionals specializing in craniofacial anomalies. The peaks and valley of Cupid's bow were identified. A cleft side (CSA) and a noncleft side angle (NCSA) were delineated and measured by each expert. The data was pooled, and the angles were analyzed for symmetry. Cupid's bow asymmetry was defined as a difference between NCSA and CSA ≥3°. Of the 37 patients studied, 29 were found to have asymmetry of Cupid's bow with an average angle difference of 8.0° (95% CI: 6.6°-9.5°). Within this group,15 patients were found with acute asymmetry and 14 with obtuse asymmetry. Geometric analysis was performed on an example of a patient with acute asymmetry to demonstrate how correction of asymmetry can be considered during surgical repair. There is an asymmetry that exists in the Cupid's bow of a significant number of patients with unoperated UCL. This finding not only adds to our understanding of UCL but may also have important implications when selecting the method/technique of surgical repair.


Assuntos
Fenda Labial , Assimetria Facial , Fotografação , Humanos , Fenda Labial/cirurgia , Feminino , Masculino , Assimetria Facial/diagnóstico por imagem , Lactente , Criança , Pré-Escolar
2.
Prostate ; 82(7): 836-849, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35226381

RESUMO

BACKGROUND: Prostatic cancers include a diverse microenvironment of tumor cells, cancer-associated fibroblasts, and immune components. This tumor microenvironment (TME) is a known driving force of tumor survival after treatment, but the standard-of-care tissue freezing or fixation in pathology practice limit the use of available approaches/tools to study the TME's functionality in tumor resistance. Thus, there is a need for approaches that satisfy both clinical and laboratory endpoints for TME study. Here we present methods for clinical case identification, tissue processing, and analytical workflow that are compatible with standard histopathology while enabling molecular and functional interrogation of prostate TME components. METHODS: We first performed a small retrospective review to identify cases where submission of alternate prostate tissue slices and a parallel live tissue processing protocol complement traditional histopathology and enable viable multicompartment analysis of the TME. Then, we tested its compatibility with commonly employed methods to study the microenvironment including quantification of components both in situ and after tissue dissociation. We also evaluated tissue digestion conditions and cell isolation techniques to aid various molecular and functional endpoints. RESULTS: We identified Gleason Grade Group 3+ clinical cases where tumor volume was sufficient to allow slicing of unfixed tissue and distribution of alternating tissue slices to standard-of-care histopathology and viable multi-modal TME analyses. No single method was found that preserved cellular sub-types for all downstream readouts; instead, tissues were further divided so techniques could be catered to each endpoint. For instance, we show that incorporating the protease dispase into tissue dissociation improves viability for culture and functional analyses but hinders immune cell analysis by flow cytometry. We also found that flow activated cell sorting provides highly pure cell populations for quantitative reverse-transcription polymerase chain reaction and RNA-seq while isolation using antibody-labeled paramagnetic particles facilitated functional coculture experiments. CONCLUSIONS: The identification of candidate cases and use of these techniques enable translational research and the development of molecular and functional assays to facilitate prostate TME study without compromising standard-of-care histopathological diagnosis. This allows bridging clinical histopathology and further interrogation of the prostate TME and promises to advance our understanding of tumor biology and unveil new predictive and prognostic markers of prostate cancer progression.


Assuntos
Fibroblastos Associados a Câncer , Neoplasias da Próstata , Obtenção de Tecidos e Órgãos , Fibroblastos Associados a Câncer/patologia , Humanos , Masculino , Próstata/patologia , Neoplasias da Próstata/patologia , Microambiente Tumoral/fisiologia
3.
Am J Occup Ther ; 76(4)2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35671509

RESUMO

IMPORTANCE: Few tools are available to assess bimanual deficits after stroke. OBJECTIVE: To develop the Bimanual Assessment Measure (BAM), which assesses a person's hand coordination in both preferred and prestroke roles (i.e., stabilizer or manipulator). DESIGN: Development and psychometric testing of the BAM. SETTING: Research laboratory. PARTICIPANTS: People with chronic stroke (n = 24), age-matched controls (n = 23), and occupational therapists (n = 40). OUTCOMES AND MEASURES: We assessed the BAM's internal consistency, reliability, and face and known-groups validity. RESULTS: Items were selected as meaningful tasks that represented a range of bimanual coordination requirements (e.g., symmetrical forces and timing, asymmetrical forces and timing, time-limited reactive movement). Focus groups of people with stroke and occupational therapists provided input into BAM development. The BAM was found to have excellent reliability and internal consistency and face and known-groups validity. CONCLUSIONS AND RELEVANCE: The BAM is a valid, reliable measure for people with chronic stroke that identifies bimanual coordination deficits beyond unimanual impairments and the potential capacity for people to return to prestroke hand roles (i.e., as a manipulator). What This Article Adds: This article introduces the BAM as a new assessment measure of bimanual functioning with the potential capacity to restore prestroke hand roles as either a manipulator or a stabilizer among people with chronic stroke.


Assuntos
Acidente Vascular Cerebral , Mãos , Humanos , Psicometria , Reprodutibilidade dos Testes , Extremidade Superior
4.
FASEB J ; 33(7): 8623-8633, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31002529

RESUMO

Aromatase inhibitors are the preferred treatment for certain women with estrogen receptor (ER)-positive breast cancer, but evidence suggests that women with obesity experience aromatase inhibitor resistance at higher rates. To compare how stromal cells derived from women who are lean or obese influence response to the aromatase inhibitor (anastrazole), we incorporated patient-derived stroma in a previously characterized MCF7-derived in vitro duct model. Coculture with adipose stromal cells enabled the metabolism of testosterone (T) to E2, which induced estrogen response element activity, epithelial proliferation, and hyperplasia in MCF7 cells. The effects of T were inhibited by the ER antagonist tamoxifen and aromatase inhibitor anastrazole and were increased by the aromatase inducer dexamethasone. Primary mammary adipose stromal cells derived from women with obesity displayed increased aromatase mRNA compared with lean controls. MCF7-derived ducts cocultured with obese stromal cells exhibited higher maximal aromatization-induced ER transactivation and reduced anastrazole sensitivity, a difference not seen in 2-dimensional coculture. Finally, tamoxifen was more effective than anastrazole at reducing aromatization-induced ER transactivation and proliferation. These findings suggest that patient-specific responses to hormone therapies can be modeled and studied organotypically in vitro and add to evidence advocating obesity as a parameter to consider when identifying treatments for patients with ER-positive breast cancer.-Morgan, M. M., Arendt, L. M., Alarid, E. T., Beebe, D. J., Johnson, B. P. Mammary adipose stromal cells derived from obese women reduce sensitivity to the aromatase inhibitor anastrazole in an organotypic breast model.


Assuntos
Adipócitos/efeitos dos fármacos , Anastrozol/farmacologia , Inibidores da Aromatase/farmacologia , Neoplasias da Mama/tratamento farmacológico , Mama/efeitos dos fármacos , Obesidade/metabolismo , Células Estromais/efeitos dos fármacos , Adipócitos/metabolismo , Mama/metabolismo , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Técnicas de Cocultura/métodos , Estrogênios/metabolismo , Feminino , Humanos , Células MCF-7 , Receptores de Estrogênio/metabolismo , Células Estromais/metabolismo , Tamoxifeno/farmacologia
5.
J Sleep Res ; 28(5): e12832, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30740838

RESUMO

Sleep is an important component of motor memory consolidation and learning, providing a critical tool to enhance training and rehabilitation. Following initial skill acquisition, memory consolidation is largely a result of non-rapid eye movement sleep over either a full night or a nap. Targeted memory reactivation is one method used to enhance this critical process, which involves the pairing of an external cue with task performance at the time of initial motor skill acquisition, followed by replay of the same cue during sleep. Application of targeted memory reactivation during sleep leads to increased functional connectivity within task-related brain networks and improved behavioural performance in healthy young adults. We have previously used targeted memory reactivation throughout the first two slow-wave sleep cycles of a full night of sleep to enhance non-dominant arm throwing accuracy in healthy young adults. Here, we aimed to determine whether application of targeted memory reactivation throughout a 1-hr daytime nap was sufficient to enhance performance on the same non-dominant arm throwing task in healthy young adults. Participants were allocated to either nap or no nap, and within those groups half received targeted memory reactivation throughout a 1-hr between-session period, leading to four groups. Only participants who slept between sessions while receiving targeted memory reactivation enhanced their throwing accuracy upon beginning the second session. Future studies will aim to use this technique as an adjunct to traditional physical rehabilitation with individuals with neurologic diagnoses such as stroke.


Assuntos
Memória/fisiologia , Destreza Motora/fisiologia , Sono/fisiologia , Vigília/fisiologia , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Adulto Jovem
6.
Arch Phys Med Rehabil ; 99(2): 411-415, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28890381

RESUMO

The purpose of this article is 2-fold: first, to inform readers of the link between the loss of motor inhibition during rapid eye movement (REM) sleep dreaming, diagnosed as REM sleep behavior disorder, and the future onset of neurodegenerative disorders, such as Parkinson disease and dementia with Lewy bodies; it has been reported that motor disinhibition during REM sleep often precedes the onset of these disorders by years or even decades; second, to consider that the identification of REM sleep behavior disorder and the early involvement of rehabilitation and/or development of home exercise plans may aid in prolonging and even increasing function, independence, and quality of life, should such neurodegenerative disorders develop later in life.


Assuntos
Terapia Ocupacional , Doença de Parkinson/fisiopatologia , Doença de Parkinson/reabilitação , Modalidades de Fisioterapia , Transtorno do Comportamento do Sono REM/fisiopatologia , Transtorno do Comportamento do Sono REM/reabilitação , Progressão da Doença , Humanos
7.
Proc Natl Acad Sci U S A ; 111(39): 14295-300, 2014 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-25225411

RESUMO

The circadian clock plays a significant role in many aspects of female reproductive biology, including estrous cycling, ovulation, embryonic implantation, onset of puberty, and parturition. In an effort to link cell-specific circadian clocks to their specific roles in female reproduction, we used the promoter that controls expression of Steroidogenic Factor-1 (SF1) to drive Cre-recombinase-mediated deletion of the brain muscle arnt-like 1 (Bmal1) gene, known to encode an essential component of the circadian clock (SF1-Bmal1(-/-)). The resultant SF1-Bmal1(-/-) females display embryonic implantation failure, which is rescued by progesterone supplementation, or bilateral or unilateral transplantation of wild-type ovaries into SF1-Bmal1(-/-) dams. The observation that the central clock, and many other peripheral clocks, are fully functional in this model allows the assignment of the implantation phenotype to the clock in ovarian steroidogenic cells and distinguishes it from more general circadian related systemic pathology (e.g., early onset arthropathy, premature aging, ovulation, late onset of puberty, and abnormal estrous cycle). Our ovarian transcriptome analysis reveals that deletion of ovarian Bmal1 disrupts expression of transcripts associated with the circadian machinery and also genes critical for regulation of progesterone production, such as steroidogenic acute regulatory factor (Star). Overall, these data provide a powerful model to probe the interlocking and synergistic network of the circadian clock and reproductive systems.


Assuntos
Fatores de Transcrição ARNTL/deficiência , Fatores de Transcrição ARNTL/fisiologia , Implantação do Embrião/fisiologia , Ovário/citologia , Ovário/fisiologia , Esteroides/biossíntese , Fatores de Transcrição ARNTL/genética , Envelhecimento/genética , Envelhecimento/fisiologia , Animais , Ritmo Circadiano/genética , Ritmo Circadiano/fisiologia , Implantação do Embrião/efeitos dos fármacos , Implantação do Embrião/genética , Estro/genética , Estro/fisiologia , Feminino , Perfilação da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ovário/transplante , Gravidez , Progesterona/administração & dosagem , Regiões Promotoras Genéticas , Maturidade Sexual/genética , Maturidade Sexual/fisiologia , Fator Esteroidogênico 1/genética
8.
Proc Natl Acad Sci U S A ; 111(52): 18757-62, 2014 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-25512522

RESUMO

The diurnal variation in acetaminophen (APAP) hepatotoxicity (chronotoxicity) reportedly is driven by oscillations in metabolism that are influenced by the circadian phases of feeding and fasting. To determine the relative contributions of the central clock and the hepatocyte circadian clock in modulating the chronotoxicity of APAP, we used a conditional null allele of brain and muscle Arnt-like 1 (Bmal1, aka Mop3 or Arntl) allowing deletion of the clock from hepatocytes while keeping the central and other peripheral clocks (e.g., the clocks controlling food intake) intact. We show that deletion of the hepatocyte clock dramatically reduces APAP bioactivation and toxicity in vivo and in vitro because of a reduction in NADPH-cytochrome P450 oxidoreductase gene expression, protein, and activity.


Assuntos
Acetaminofen/farmacocinética , Analgésicos não Narcóticos/farmacocinética , Ritmo Circadiano , Sistema Enzimático do Citocromo P-450/biossíntese , Regulação da Expressão Gênica no Desenvolvimento , Hepatócitos/enzimologia , Acetaminofen/efeitos adversos , Acetaminofen/farmacologia , Analgésicos não Narcóticos/efeitos adversos , Analgésicos não Narcóticos/farmacologia , Animais , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/genética , Peptídeos e Proteínas de Sinalização do Ritmo Circadiano/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Hepatócitos/patologia , Camundongos , Camundongos Transgênicos
9.
Angew Chem Int Ed Engl ; 55(47): 14833-14837, 2016 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-27781348

RESUMO

The cyclo-P4 complexes [CpR Ta(CO)2 (η4 -P4 )] (CpR : Cp''=1,3-C5 H3 tBu2 , Cp'''=1,2,4-C5 H2 tBu3 ) turned out to be predestined for the formation of hollow spherical supramolecules with non-classical fullerene-like topology. The resulting assemblies constructed with CuX (X=Cl, Br) showed a highly symmetric 32-vertex core of solely four- and six-membered rings. In some supramolecules, the inner cavity was occupied by an additional CuX unit. On the other hand, using CuI, two different supramolecules with either peanut- or pear-like shapes and outer diameters in the range of 2-2.5 nm were isolated. Furthermore, the spherical supramolecules containing Cp''' ligands at tantalum are soluble in CH2 Cl2 . NMR spectroscopic investigations in solution revealed the formation of isomeric supramolecules owing to the steric hindrance caused by the third tBu group on the Cp''' ligand. In addition, a 2D coordination polymer was obtained and structurally characterized.

10.
Chem Rec ; 15(6): 1165-74, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26745261

RESUMO

Bonding beyond Borders is a fitting title to the Nozoe Autograph Books project, as the books and their publication involved innumerable contributors from around the globe all in the spirit of personal collaboration. The editors of this project share details of how the project came into being and give their own personal assessment of what it has become and what it means.

11.
Chem Rec ; 15(1): 412-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25690992

RESUMO

All are welcome! This issue contains the final of the 15 segments of the original Nozoe Autograph Books. But this project couldn't just stop here. A modern extension of the autograph books-a 16(th) segment-will be published and will include signatures from around today's chemistry community. All are welcome to participate and add their mark on the legacy of the Nozoe Autograph Books. See the Essay for details. This Essay and the interactive website that accompanies the Nozoe Autograph Book project are available free-access for at least a three-year period at http://www.tcr.wiley-vch.de/nozoe.

12.
bioRxiv ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38187691

RESUMO

Plasma thyroid hormone (TH) binding proteins (THBPs), including thyroxine-binding globulin (TBG), transthyretin (TTR), and albumin (ALB), carry THs to extrathyroidal sites, where THs are unloaded locally and then taken up via membrane transporters into the tissue proper. The respective roles of THBPs in supplying THs for tissue uptake are not completely understood. To investigate this, we developed a spatial human physiologically based kinetic (PBK) model of THs, which produces several novel findings. (1) Contrary to postulations that TTR and/or ALB are the major local T4 contributors, the three THBPs may unload comparable amounts of T4 in Liver, a rapidly perfused organ; however, their contributions in slowly perfused tissues follow the order of abundances of T4TBG, T4TTR, and T4ALB. The T3 amounts unloaded from or loaded onto THBPs in a tissue acting as a T3 sink or source respectively follow the order of abundance of T3TBG, T3ALB, and T3TTR regardless of perfusion rate. (2) Any THBP alone is sufficient to maintain spatially uniform TH tissue distributions. (3) The TH amounts unloaded by each THBP species are spatially dependent and nonlinear in a tissue, with ALB being the dominant contributor near the arterial end but conceding to TBG near the venous end. (4) Spatial gradients of TH transporters and metabolic enzymes may modulate these contributions, producing spatially invariant or heterogeneous TH tissue concentrations depending on whether the blood-tissue TH exchange operates in near-equilibrium mode. In summary, our modeling provides novel insights into the differential roles of THBPs in local TH tissue distribution.

13.
Brain Sci ; 14(1)2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38248280

RESUMO

Motor memories can be strengthened through online practice and offline consolidation. Offline consolidation involves the stabilization of memory traces in post-practice periods. Following initial consolidation of a motor memory, subsequent practice of the motor skill can lead to reactivation and reconsolidation of the memory trace. The length of motor memory reactivation may influence motor learning outcomes; for example, brief, as opposed to long, practice of a previously learned motor skill appears to optimize intermanual transfer in healthy young adults. However, the influence of aging on reactivation-based motor learning has been scarcely explored. Here, the effects of brief and long motor memory reactivation schedules on the retention and intermanual transfer of a visuomotor tracing task are explored in healthy older adults. Forty older adults practiced a virtual star-tracing task either three ("brief reactivation") or ten ("long reactivation") times per session over a two-week period. Comparison with a previously reported group of younger adults revealed significant age-related differences in the effect of the motor memory reactivation schedule on the intermanual transfer of the motor task. In older adults, unlike younger adults, no significant between-group differences were found by practice condition in the speed, accuracy, or skill of intermanual task transfer. That is, motor task transfer in healthy younger, but not older, adults appears to benefit from brief memory reactivation. These results support the use of age-specific motor training approaches and may inform motor practice scheduling, with possible implications for physical rehabilitation, sport, and music.

14.
Chem Rec ; 18(1): 2-3, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29314559
15.
BMC Geriatr ; 13: 39, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23635315

RESUMO

BACKGROUND: Regional variation in the intensity of end-of-life care contributes significantly to the overall cost of health care. The interpretation of patterns of regional variation hinges, in part, on appropriate adjustment for regional variation in demographic variables such as age, race, sex, and rural vs. urban residence. This study examined regional variation in discontinuation of dialysis prior to death in the US, after adjustment for key demographic variables. METHODS: In this retrospective cohort study of the 2009 United States Renal Data System (USRDS) database we examined discontinuation of dialysis prior to death among deceased adult patients with end-stage renal disease (ESRD) from the 50 states and the District of Columbia. The discontinuation of dialysis prior to death was ascertained from the Centers for Medicare & Medicaid Services form 2746 (ESRD Death Notification form). We used logistic regression to estimate the log-odds of discontinuation of dialysis with ESRD network as independent variable adjusted for urban-rural status, demographic and treatment variables. RESULTS: The study cohort included 715,605 deceased ESRD patients; for 176,021 of whom (24.6%) dialysis was discontinued prior to death. Dialysis was discontinued at higher rates for women than for men (26.3% vs. 23.0%, p < 0.001) and for whites than for blacks (29.5% vs. 14.7%, p < 0.001). Significant regional variation in dialysis discontinuation prior to death was noted after adjustment for age, race and rural-urban status: rates of discontinuation in the Upper Midwest and Mountain regions were more than double the rates in Southern and Coastal regions. This pattern parallels the regional pattern of end-of-life health service utilization documented in the Dartmouth Atlas and other studies. CONCLUSIONS: Discontinuation of dialysis prior to death was common in the US between 1995 and 2009. The deaths of nearly one quarter of chronic dialysis patients followed a decision to discontinue dialysis. Significant regional variation in discontinuation rates exists after adjusting for age, race, sex, and rural-urban status. Further research and analysis is needed on the cultural and economic factors that affect regional variation in health services utilization, especially in regard to the use of expensive medical services near the end of life.


Assuntos
Falência Renal Crônica/etnologia , Falência Renal Crônica/terapia , Diálise Renal/tendências , Assistência Terminal/tendências , Suspensão de Tratamento/tendências , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Bases de Dados Factuais/tendências , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Grupos Raciais/etnologia , Sistema de Registros , Diálise Renal/métodos , Estudos Retrospectivos , População Rural/tendências , Assistência Terminal/métodos , Estados Unidos/etnologia , População Urbana/tendências
16.
Minn Med ; 96(7): 45-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24133890

RESUMO

This article describes an intervention for breast cancer survivors called Journal of My Medical Experiences in which participants engaged in reflective writing over six weeks. The 107 participants were encouraged to explore concerns and issues in a safe online environment. About half of the women posted writings to a website once a week or more; others logged on solely to read what others had written. A number of themes emerged as the women explored their feelings. We share some of those.


Assuntos
Neoplasias da Mama/psicologia , Criatividade , Medicina na Literatura , Cura Mental/psicologia , Sobreviventes/psicologia , Redação , Adaptação Psicológica , Feminino , Humanos , Minnesota
17.
Handb Clin Neurol ; 196: 599-609, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37620093

RESUMO

Various levels of somatotopic organization are present throughout the human nervous system. However, this organization can change when needed based on environmental demands, a phenomenon known as neuroplasticity. Neuroplasticity can occur when learning a new motor skill, adjusting to life after blindness, or following a stroke. Following an injury, these neuroplastic changes can be adaptive or maladaptive, and often occur regardless of whether rehabilitation occurs or not. But not all movements produce neuroplasticity, nor do all rehabilitation interventions. Here, we focus on research regarding how to maximize adaptive neuroplasticity while also minimizing maladaptive plasticity, known as applied neuroplasticity. Emphasis is placed on research exploring how best to apply neuroplastic principles to training environments and rehabilitation protocols. By studying and applying these principles in research and clinical practice, it is hoped that learning of skills and regaining of function and independence can be optimized.


Assuntos
Aprendizagem , Destreza Motora , Humanos , Movimento , Plasticidade Neuronal , Procedimentos Neurocirúrgicos
18.
Front Endocrinol (Lausanne) ; 14: 1168663, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37305053

RESUMO

The thyroid hormones (THs), thyroxine (T4) and triiodothyronine (T3), are under homeostatic control by the hypothalamic-pituitary-thyroid axis and plasma TH binding proteins (THBPs), including thyroxine-binding globulin (TBG), transthyretin (TTR), and albumin (ALB). THBPs buffer free THs against transient perturbations and distribute THs to tissues. TH binding to THBPs can be perturbed by structurally similar endocrine-disrupting chemicals (EDCs), yet their impact on circulating THs and health risks are unclear. In the present study, we constructed a human physiologically based kinetic (PBK) model of THs and explored the potential effects of THBP-binding EDCs. The model describes the production, distribution, and metabolism of T4 and T3 in the Body Blood, Thyroid, Liver, and Rest-of-Body (RB) compartments, with explicit consideration of the reversible binding between plasma THs and THBPs. Rigorously parameterized based on literature data, the model recapitulates key quantitative TH kinetic characteristics, including free, THBP-bound, and total T4 and T3 concentrations, TH productions, distributions, metabolisms, clearance, and half-lives. Moreover, the model produces several novel findings. (1) The blood-tissue TH exchanges are fast and nearly at equilibrium especially for T4, providing intrinsic robustness against local metabolic perturbations. (2) Tissue influx is limiting for transient tissue uptake of THs when THBPs are present. (3) Continuous exposure to THBP-binding EDCs does not alter the steady-state levels of THs, while intermittent daily exposure to rapidly metabolized TBG-binding EDCs can cause much greater disruptions to plasma and tissue THs. In summary, the PBK model provides novel insights into TH kinetics and the homeostatic roles of THBPs against thyroid disrupting chemicals.


Assuntos
Plasma , Hormônios Tireóideos , Humanos , Cinética , Tiroxina , Tri-Iodotironina
19.
Chem Rec ; 17(1): 2-3, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28075063
20.
J Immunol ; 185(6): 3190-8, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20720200

RESUMO

The aryl hydrocarbon receptor (AHR) has been known to cause immunosuppression after binding dioxin. It has recently been discovered that the receptor may be central to T cell differentiation into FoxP3(+) regulatory T cells (Tregs) versus Th17 cells. In this paper, we demonstrate that kynurenine, the first breakdown product in the IDO-dependent tryptophan degradation pathway, activates the AHR. We furthermore show that this activation leads to AHR-dependent Treg generation. We additionally investigate the dependence of TGF-beta on the AHR for optimal Treg generation, which may be secondary to the upregulation of this receptor that is seen in T cells postexposure to TGF-beta. These results shed light on the relationship of IDO to the generation of Tregs, in addition to highlighting the central importance of the AHR in T cell differentiation. All tissues and cells were derived from mice.


Assuntos
Diferenciação Celular/imunologia , Cinurenina/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , Animais , Diferenciação Celular/genética , Linhagem Celular Tumoral , Células Cultivadas , Técnicas de Cocultura , Células Dendríticas/enzimologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Relação Dose-Resposta Imunológica , Indolamina-Pirrol 2,3,-Dioxigenase/química , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/fisiologia , Cinurenina/química , Cinurenina/fisiologia , Ligantes , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Hidrocarboneto Arílico/deficiência , Receptores de Hidrocarboneto Arílico/fisiologia , Transdução de Sinais/imunologia , Linfócitos T Reguladores/metabolismo , Fator de Crescimento Transformador beta/fisiologia , Triptofano/química , Triptofano/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA