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1.
Med Probl Perform Art ; 39(2): 56-63, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38814124

RESUMO

BACKGROUND: Developmental dysplasia of the hip (DDH) is common in performing artists and other young active individuals and involves abnormalities in bony morphology of the acetabulum and proximal femur that can negatively impact walking biomechanics, muscular strength, quality of life, and sleep. Rehabilitation for hip-related conditions should target known modifiable impairments such as hip muscle strength, though a reliable method of assessment in this population remains unclear. OBJECTIVE: To determine the inter- and intra-rater reliability of hip muscle strength assessments using handheld dynamometry (HHD) in young active circus artists with DDH. METHODS: Reliability of hip strength in all planes was assessed using HHD in 21 adult performing circus arts students (mean age 21.3 yrs [3.2]; 13 M, 5 F, 3 NB) with symptomatic radiologically and clinically diagnosed hip dysplasia. The reliability of average peak force and absolute peak force were expressed for each position tested. Reliability was assessed using intraclass correlation coefficients (ICC) with standard error of measurement (SEM) and minimal detectable change (MDC) values calculated to improve clinical interpretability. RESULTS: Good to excellent inter-rater reliability resulted for all hip muscle strength testing positions, ICC=0.88 (95%CI 0.70 to 0.95) to ICC=0.97 (0.92 to 0.99), except average peak hip flexion strength, ICC=0.71 (0.28 to 0.88). Absolute peak hip abduction, ICC=0.77 (0.16 to 0.94), and adduction strength, ICC=0.72 (-0.55 to 0.92), demonstrated the lowest intra-rater reliability. Transverse plane strength measures (rotation) produced the lowest SEM and MDC values followed by the frontal plane (abduction/adduction) and sagittal plane (flexion/extension). CONCLUSION: HHD is an appropriate and reliable method to assess hip muscle strength in circus artists with DDH.


Assuntos
Força Muscular , Humanos , Força Muscular/fisiologia , Reprodutibilidade dos Testes , Feminino , Masculino , Adulto Jovem , Articulação do Quadril/fisiopatologia , Dinamômetro de Força Muscular , Adulto , Displasia do Desenvolvimento do Quadril/fisiopatologia
2.
Phys Rev Lett ; 127(12): 125001, 2021 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-34597087

RESUMO

Inertial confinement fusion implosions designed to have minimal fluid motion at peak compression often show significant linear flows in the laboratory, attributable per simulations to percent-level imbalances in the laser drive illumination symmetry. We present experimental results which intentionally varied the mode 1 drive imbalance by up to 4% to test hydrodynamic predictions of flows and the resultant imploded core asymmetries and performance, as measured by a combination of DT neutron spectroscopy and high-resolution x-ray core imaging. Neutron yields decrease by up to 50%, and anisotropic neutron Doppler broadening increases by 20%, in agreement with simulations. Furthermore, a tracer jet from the capsule fill-tube perturbation that is entrained by the hot-spot flow confirms the average flow speeds deduced from neutron spectroscopy.

3.
Med Probl Perform Art ; 36(3): 163-175, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34464962

RESUMO

OBJECTIVE: To explore the subjective experiences of student circus arts performers with atraumatic shoulder instability undertaking a 12-week shoulder rehabilitation program during the COVID-19 pandemic lockdown, in Melbourne, Australia. METHODS: Using a qualitative design, 14 circus arts students from the National Institute of Circus Arts (Australia) were individually interviewed via teleconsultation. All interviews were recorded, transcribed, and analysed using inductive thematic analysis. RESULTS: Five overarching themes were identified: (i) impact (physical and mental), (ii) opportunity, (iii) developing routine, (iv) client-therapist relationship, and (v) transformation. All participants reported positive physical changes to their shoulder including increases in strength, stability, range of motion, less pain, "clicking" and "clunking," improved posture, muscle memory, as well as carry-over to functional circus activities. The pandemic's mental impact varied across the cohort, with positive and negative experiences described in relation to cognitive, social, and affective factors. Most performers felt the pandemic provided an opportunity to focus on rehabilitation of their shoulder. The program effects were also underpinned by positive client-therapist relationships and a progressive transformation of learning where students gained knowledge of their condition, developed tools to manage their current shoulder impairment, and learned how to apply this new knowledge to future management of their condition. CONCLUSION: A shoulder exercise intervention delivered via teleconsultation during the COVID-19 pandemic resulted in subjective reports of positive physical changes to the participants' shoulder health complaint. This was facilitated through client-physiotherapist relationships, providing structure during uncertain times, and by providing education to help in understanding their condition and its future management.


Assuntos
COVID-19 , Instabilidade Articular , Articulação do Ombro , Telemedicina , Controle de Doenças Transmissíveis , Humanos , Pandemias , Encaminhamento e Consulta , SARS-CoV-2 , Ombro , Estudantes
4.
Radiography (Lond) ; 30(2): 468-473, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38215682

RESUMO

INTRODUCTION: Patients suffering from head and neck (HN) cancer undergoing Radiotherapy (RT) suffer from various debilitating side effects that greatly hinder their eating ability. This leads to patients having a poor nutritional status causing weight loss. This study aimed to assess if an e-Delphi method variation allowed efficiently developing dietary advice leaflets addressing these side effects and achieving a consensus among healthcare professionals. METHODS: An e-Delphi style approach was used. Six participants representing the professions working with HN patients were asked to give feedback on four symptom-specific dietary leaflets. These leaflets were designed based on a previous extensive literature review. After each round, the participants' suggested changes were applied. Before applying major changes to the leaflet, the participants were asked to vote if they agreed with each major change. RESULTS: Overall consensus was reached after three rounds since all participants voted "highly likely" to use it in their clinical practice. Most suggestions by the participants agreed with the existing literature. The only change (accepted as a result of voting) that contradicted the literature was concerning sugar intake. CONCLUSION: The participants reached consensus and developed leaflets that were based on literature recommendations for use for patients that, in their opinion, were acceptable for clinical use. This e-Delphi variation proved to be efficient to achieve consensus among healthcare professionals regarding patient information tools. IMPLICATIONS FOR PRACTICE: This eDelphi method is an efficient and effective way to revise and achieve consensus regarding the development of patient information material.


Assuntos
Neoplasias de Cabeça e Pescoço , Humanos , Consenso , Neoplasias de Cabeça e Pescoço/radioterapia
5.
Phys Rev Lett ; 108(21): 215004, 2012 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-23003273

RESUMO

Ignition implosions on the National Ignition Facility [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)] are underway with the goal of compressing deuterium-tritium fuel to a sufficiently high areal density (ρR) to sustain a self-propagating burn wave required for fusion power gain greater than unity. These implosions are driven with a very carefully tailored sequence of four shock waves that must be timed to very high precision to keep the fuel entropy and adiabat low and ρR high. The first series of precision tuning experiments on the National Ignition Facility, which use optical diagnostics to directly measure the strength and timing of all four shocks inside a hohlraum-driven, cryogenic liquid-deuterium-filled capsule interior have now been performed. The results of these experiments are presented demonstrating a significant decrease in adiabat over previously untuned implosions. The impact of the improved shock timing is confirmed in related deuterium-tritium layered capsule implosions, which show the highest fuel compression (ρR~1.0 g/cm(2)) measured to date, exceeding the previous record [V. Goncharov et al., Phys. Rev. Lett. 104, 165001 (2010)] by more than a factor of 3. The experiments also clearly reveal an issue with the 4th shock velocity, which is observed to be 20% slower than predictions from numerical simulation.

6.
Rev Sci Instrum ; 92(4): 043512, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243456

RESUMO

Nuclear diagnostics provide measurements of inertial confinement fusion implosions used as metrics of performance for the shot. The interpretation of these measurements for shots with low mode asymmetries requires a way of combining the data to produce a "sky map" where the individual line-of-sight values are used to interpolate to other positions in the sky. These interpolations can provide information regarding the orientation of the low mode asymmetries. We describe the interpolation method, associated uncertainties, and correlations between different metrics, e.g., Tion, down scatter ratio, and hot-spot velocity direction. This work is also related to recently reported studies [H. G. Rinderknecht et al., Phys. Rev. Lett. 124, 145002 (2020) and K. M. Woo et al., Phys. Plasmas 27, 062702 (2020)] of low mode asymmetries. We report an analysis that makes use of a newly commissioned line of sight, a scheme for incorporating multiple neutron spectrum measurement types, and recent work on the sources of implosion asymmetry to provide a more complete picture of implosion performance.

7.
Rev Sci Instrum ; 92(2): 023513, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33648112

RESUMO

The measurement of plasma hotspot velocity provides an important diagnostic of implosion performance for inertial confinement fusion experiments at the National Ignition Facility. The shift of the fusion product neutron mean kinetic energy as measured along multiple line-of-sight time-of-flight spectrometers provides velocity vector components from which the hotspot velocity is inferred. Multiple measurements improve the hotspot velocity inference; however, practical considerations of available space, operational overhead, and instrumentation costs limit the number of possible line-of-sight measurements. We propose a solution to this classical "experiment design" problem that optimizes the precision of the velocity inference for a limited number of measurements.

8.
J Cell Biol ; 65(2): 428-38, 1975 May.
Artigo em Inglês | MEDLINE | ID: mdl-1127018

RESUMO

Methods of tissue dissociation and cell separation have been modified to obtain highly enriched fractions of mouse gastric parietal cells. Suspension of gastric mucosal cells are prepared by pronase digestion of the glandular portion of the stomach from adult mice. By utilizing the velocity sedimentation technique to separate cells of different sizes it is possible to recovery parietal cells, which are larger than the other cell types, in fractions with purity of 75-95%. The homogeneity of cell fractions has been assessed by light and electron microscopy. The ability of the isolated cells to exclude the dye trypan blue, to incorporate labeled substrate, to consume oxygen, and to retain their structural integrity indicates that they are viable and still capable of functional activity.


Assuntos
Separação Celular/métodos , Mucosa Gástrica/citologia , Animais , Centrifugação com Gradiente de Concentração , Grânulos Citoplasmáticos/ultraestrutura , Mucosa Gástrica/ultraestrutura , Camundongos , Microscopia Eletrônica , Microscopia de Interferência , Organoides/ultraestrutura , Consumo de Oxigênio , Pronase/metabolismo
10.
Ecology ; 89(12): 3306-16, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19137938

RESUMO

Torpor is a reversible reduction in endotherm body temperature and metabolic rate. Because torpid endotherms can attain lower body temperatures in colder environments, minimum torpor metabolism generally increases with rising air temperature whereas euthermic metabolism generally declines with rising air temperature. As a result, the fundamental metabolic niche of endotherms that express torpor should be driven by climate and should be broadest in colder environments. On the other hand, if torpor serves primarily as an energy conservation strategy and its expression is influenced by energy availability, then the realized metabolic niche should be defined by resources. To evaluate the influence of resource and climate on torpor use and metabolism of hibernating mammals, we monitored the torpor expression of free-ranging eastern chipmunks (Tamias striatus) over two winters of varying resource abundance. In the low-food year, soil temperature constrained maximum torpor expression but was too invariant across small spatial scales to explain individual variation in torpor expression. In the high-food year, torpor was drastically reduced, and local density of seed-producing trees predicted fine-scale spatial variation in torpor expression. Thus, the fundamental metabolic niche of hibernating chipmunks in cold environments is broad and constrained by climate, whereas the realized metabolic niche is highly variable among individuals and years and is determined primarily by local resource abundance.


Assuntos
Clima , Metabolismo Energético/fisiologia , Abastecimento de Alimentos , Hibernação/fisiologia , Sciuridae/fisiologia , Análise de Variância , Animais , Temperatura Corporal/fisiologia , Feminino , Privação de Alimentos/fisiologia , Masculino , Sciuridae/metabolismo , Telemetria
11.
J Clin Invest ; 72(4): 1352-6, 1983 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6138363

RESUMO

Studies were carried out with the serum IgG from a mother and her two children who developed neonatal Graves' disease several weeks after birth. The maternal IgG: (a) stimulated the human thyroid in vitro, but maximal stimulation was found only with dilution of the IgG; (b) was very potent in the long-acting thyroid stimulator (LATS)-protector assay, but only when an inhibitor of the system was diluted out; (c) inhibited a standard preparation of LATS in the mouse bioassay; (d) was biphasic in the thyrotropin-binding inhibition (TBI) assay, i.e., enhanced binding at low concentrations of IgG and inhibited binding at high levels. Enhancement in the TBI assay was found only with particulate preparations of human thyroid membranes as receptor and not when that material was solubilized, nor with guinea pig fat cell membranes as receptor. Serial blood samples from the second child were obtained at birth and until 3 mo of age. In the thyroid slice (cyclic AMP) assay system there was a negative dose-response relationship in testing IgG until age 45 d when it became positive, coinciding with the clinical recognition that hyperthyroidism had developed. The data are compatible with a concept that this mother's IgG contained thyroid-stimulating antibody (TSAb) and another moiety that inhibited TSAb through an action on the thyroid cell membrane, thus delaying the onset of hyperthyroidism in the neonate until the inhibiting IgG was metabolically cleared to an ineffective concentration.


Assuntos
Doença de Graves/imunologia , Imunoglobulina G/fisiologia , Animais , Anticorpos/análise , Ligação Competitiva , Feminino , Doença de Graves/congênito , Doença de Graves/diagnóstico , Humanos , Imunoglobulina G/análise , Imunoglobulinas Estimuladoras da Glândula Tireoide , Lactente , Recém-Nascido , Estimulador Tireóideo de Ação Prolongada/análise , Membranas/metabolismo , Camundongos , Glândula Tireoide , Hormônio Liberador de Tireotropina/metabolismo
12.
Rev Sci Instrum ; 87(11): 11E715, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27910388

RESUMO

The Neutron Imaging System at the National Ignition Facility is used to observe the primary ∼14 MeV neutrons from the hotspot and down-scattered neutrons (6-12 MeV) from the assembled shell. Due to the strong spatial dependence of the primary neutron fluence through the dense shell, the down-scattered image is convolved with the primary-neutron fluence much like a backlighter profile. Using a characteristic scattering angle assumption, we estimate the primary neutron fluence and compensate the down-scattered image, which reveals information about asymmetry that is otherwise difficult to extract without invoking complicated models.

13.
Rev Sci Instrum ; 87(11): 11D841, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27910423

RESUMO

A common analysis procedure minimizes the ln-likelihood that a set of experimental observables matches a parameterized model of the observation. The model includes a description of the underlying physical process as well as the instrument response function (IRF). In the case investigated here, the National Ignition Facility (NIF) neutron time-of-flight (nTOF) spectrometers, the IRF is constructed from measurements and models. IRF measurements have a finite precision that can make significant contributions to determine the uncertainty estimate of the physical model's parameters. We apply a Bayesian analysis to properly account for IRF uncertainties in calculating the ln-likelihood function used to find the optimum physical parameters.

14.
Phys Rev E ; 94(2-1): 021202, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27627237

RESUMO

An accurate understanding of burn dynamics in implosions of cryogenically layered deuterium (D) and tritium (T) filled capsules, obtained partly through precision diagnosis of these experiments, is essential for assessing the impediments to achieving ignition at the National Ignition Facility. We present measurements of neutrons from such implosions. The apparent ion temperatures T_{ion} are inferred from the variance of the primary neutron spectrum. Consistently higher DT than DD T_{ion} are observed and the difference is seen to increase with increasing apparent DT T_{ion}. The line-of-sight rms variations of both DD and DT T_{ion} are small, ∼150eV, indicating an isotropic source. The DD neutron yields are consistently high relative to the DT neutron yields given the observed T_{ion}. Spatial and temporal variations of the DT temperature and density, DD-DT differential attenuation in the surrounding DT fuel, and fluid motion variations contribute to a DT T_{ion} greater than the DD T_{ion}, but are in a one-dimensional model insufficient to explain the data. We hypothesize that in a three-dimensional interpretation, these effects combined could explain the results.

15.
Biochim Biophys Acta ; 379(1): 239-46, 1975 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-1115798

RESUMO

Both the long-acting thyroid stimulator and the long-acting thyroid stimulator protector are associated with the immunoglobulin G fraction of human serum proteins. Fractionation of globulins by (NH4)2SO4 precipitation and DEAE-cellulose chromatography showed that the protector activity was associated with subfractions of differing electrophoretic mobility. Attempts to concentrate the protector in immunochemically pure immunoglobulin G prepared in this way may fail because of loss of protector activity with other immunoglobulin G fractions. Gel filtration on Sephadex G-150 indicated that protector activity was associated with 7-S proteins.


Assuntos
Hipertireoidismo/imunologia , Imunoglobulina G , Estimulador Tireóideo de Ação Prolongada , Animais , Sítios de Ligação , Bioensaio , Cromatografia DEAE-Celulose , Cromatografia em Gel , Humanos , Imunoglobulina G/isolamento & purificação , Camundongos , Ligação Proteica
16.
Cell Calcium ; 15(5): 369-80, 1994 May.
Artigo em Inglês | MEDLINE | ID: mdl-8033195

RESUMO

Cyclopiazonic acid (CPA) has been reported to inhibit the Ca(2+)-ATPase of the sarcoplasmic reticulum (SR) in skeletal and smooth muscle. In the present study the effect of CPA on [Ca2+]i and force in rat urinary bladder smooth muscle was examined. The fluorescent Ca2+ indicator Fura-2 was used to monitor intracellular Ca2+, simultaneously with isometric force production. Addition of CPA to unstimulated muscles bathed in 2.5 mM Ca2+ containing Krebs solution resulted in a significant and sustained increase in [Ca2+]i from 99 +/- 7 to 273 +/- 51 nM. This increase in [Ca2+]i was dependent upon the presence of extracellular Ca2+ since when CPA was added to muscles in Ca(2+)-free media it produced only a small, transient increase in [Ca2+]i that was not sustained. Peak force levels produced by transmural stimulation, carbachol and high KCl solution were not altered by the presence of CPA, however, the increase in [Ca2+]i associated with these contractions was larger when CPA was present. In response to transmural stimulation, the times taken for both force and [Ca2+]i to rise to 50% of their peak values were attenuated in the presence of CPA. Conversely, there was no effect of CPA on the times taken for force or [Ca2+]i to fall to 50% of their stimulated values upon the cessation of stimulation. Under control conditions both carbachol and high KCl could initiate transient increases in [Ca2+]i and force in the absence of extracellular Ca2+. In the presence of CPA, the response to carbachol was virtually completely inhibited, however, the response to high KCl was only partially inhibited. The ability of CPA to inhibit the carbachol response in Ca(2+)-free media suggests that this response is due to release of Ca2+ from the SR. The incomplete inhibition of the response to KCl indicates other Ca2+ storage sites may also be mobilised by sarcolemmal depolarisation. Although the mechanism whereby CPA induces a large, sustained rise in [Ca2+]i remains unknown, the data lend support to the suggestion that depletion of intracellular Ca2+ storage sites may activate a Ca2+ entry pathway across the sarcolemma.


Assuntos
Cálcio/fisiologia , Indóis/farmacologia , Músculo Liso/fisiologia , Animais , Carbacol/farmacologia , Técnicas In Vitro , Masculino , Contração Muscular/efeitos dos fármacos , Contração Muscular/fisiologia , Ratos , Ratos Sprague-Dawley , Retículo Sarcoplasmático/fisiologia , Bexiga Urinária/fisiologia
17.
J Endocrinol ; 95(2): 237-44, 1982 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-6294208

RESUMO

We have described a system for the maintenance in culture of isolated human thyroid cells from both thyrotoxic tissue and non-toxic goitres. The cells isolated from the two thyroid tissue types showed similar cyclic AMP response characteristics to TSH with large increases in intracellular and extracellular cyclic AMP after 20-min incubations. Maximal responses were obtained with 50 mu. TSH/ml and half-maximal responses at 1.0 mu. TSH/ml. With cell passage the cyclic AMP responses to TSH decreased in magnitude and sensitivity. As with other thyroid cultures, growth of the cells with TSH induced arrangement into follicular structures, whereas cells grown in the absence of TSH remained as a monolayer. Basal intracellular cyclic AMP levels were increased in a dose-related fashion in cells grown in the presence of graded concentrations of TSH and the maximal response to further additions of TSH was not greater than in control cultures.


Assuntos
AMP Cíclico/metabolismo , Bócio/metabolismo , Hipertireoidismo/metabolismo , Glândula Tireoide/metabolismo , Tireotropina/farmacologia , Células Cultivadas , Feminino , Humanos , Masculino , Glândula Tireoide/efeitos dos fármacos , Fatores de Tempo
18.
J Endocrinol ; 93(3): 371-80, 1982 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6123540

RESUMO

A detailed comparison between the use of human and porcine thyroid membranes for the radioreceptor assay (RRA) of bovine TSH (bTSH) and thyrotrophin-binding inhibiting immunoglobulins (TBIIg) is reported. Bovine thyroid membranes were also investigated but were found to be far less satisfactory than either human or porcine thyroid membranes. The affinity constant (ka) of the interaction of bTSH with porcine thyroid membranes (Ka = 3.3 X 10(9) l/mol) measured b Scatchard analysis was higher than with human thyroid membranes (Ka = 2.1 X 10(8) l/mol). Porcine thyroid membranes were more sensitive for the assay of bTSH (detection limit 30 microunits, half-maximal inhibition 0.3 microunit) than human thyroid membranes (detection limit 200 microunits, half-maximal inhibition 7.4 mu.). Preincubation of membranes from either species with immunoglobulin rich in long-acting thyroid stimulator (LATS) inhibited the saturable binding of 125I-labelled TSH to a greater extent than did normal immunoglobulin. The binding of 125I-labelled TSH to porcine membranes was more sensitive to the inhibitory effect of LATS-immunoglobulin and was also less affected by normal immunoglobulin than was binding to human thyroid membranes. When assayed with each type of membrane preparation there was good correlation between the RRA of immunoglobulins prepared from patients with Grave's disease and from normal subjects (n = 18) (r = 0.85, P less than 0.001, n = 73). The incidence of positive TBIIg in untreated Grave's disease was greater for porcine than for human thyroid membranes.


Assuntos
Imunoglobulina G/análise , Glândula Tireoide/metabolismo , Tireotropina/análise , Animais , Bovinos , Membrana Celular/metabolismo , Doença de Graves/metabolismo , Humanos , Imunoglobulinas Estimuladoras da Glândula Tireoide , Estimulador Tireóideo de Ação Prolongada/metabolismo , Ensaio Radioligante , Suínos
19.
J Endocrinol ; 108(3): 393-8, 1986 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3486241

RESUMO

Subconfluent human thyroid cells in monolayer, isolated from thyrotoxic tissue or non-toxic goitres obtained at surgery, responded to the addition of epidermal growth factor (EGF) with an increase in cell growth as measured by increased incorporation of [3H]thymidine into trichloroacetic acid-precipitable material. The growth response to EGF was concentration-dependent and the characteristics of the responses were the same using EGF from murine or human sources. With concentrations which stimulated growth, EGF was found to inhibit human thyroid cell function as measured by the release of radioimmunoassayable tri-iodothyronine into the incubation medium. Thyrotrophin (TSH) was also found to stimulate human thyroid cell growth but at concentrations far lower than those used to stimulate thyroid cell function in this system. The effect of EGF on the differentiating action of TSH on human thyroid cells in culture was also investigated; the association of thyroid cells into two-dimensional follicular structures produced by the incubation of thyroid cells at a high cell density with TSH was found to be inhibited by the addition of EGF.


Assuntos
Hipertireoidismo/patologia , Glândula Tireoide/patologia , Células Cultivadas , Fator de Crescimento Epidérmico/farmacologia , Bócio/patologia , Bócio/fisiopatologia , Humanos , Hipertireoidismo/fisiopatologia , Estimulação Química , Timidina/metabolismo , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/fisiopatologia , Tireotropina/farmacologia , Tri-Iodotironina/metabolismo
20.
J Endocrinol ; 123(3): 495-500, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2607258

RESUMO

Human thyroid epithelial cells in monolayer culture were found to release radioimmunoassayable insulin-like growth factor-I (IGF-I) over a 48-h culture period in serum-free medium. In the presence of supraphysiological concentrations of TSH (1-100 mU/ml) known to be inhibitory to DNA synthesis by human thyroid cells, the release of IGF-I was found to be inhibited in six thyroid cultures studied. In only one out of the six was IGF-I release increased in the presence of physiological mitogenic concentrations of TSH (0.1-100 microU/ml). Human thyroid fibroblasts, established by long-term culture of thyroid epithelial cells under fibroblast-selective conditions, also secreted IGF-I which was unaffected by the presence of TSH at both low and high concentrations. Using a monoclonal antibody against human IGF-I, monolayer cultures of both human thyroid epithelial cells and human thyroid fibroblasts showed positive immunocytochemical staining for IGF peptide. However, fixed sections of intact thyroid tissue only showed positive staining for IGF peptide associated with the fibrous layers surrounding the thyroid follicle, with no staining of the follicular epithelial cells. The growth of human thyroid epithelial cells was also found to be increased by IGF-I (25-100 ng/ml) added in medium plus 1% fetal calf serum as assessed by the incorporation of [3H]thymidine into DNA. In the presence of a monoclonal antibody to IGF-I the increase in [3H]thymidine uptake in response to IGF-I was abolished as was that seen in response to TSH.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Fator de Crescimento Insulin-Like I/fisiologia , Somatomedinas/fisiologia , Glândula Tireoide/citologia , Tireotropina/farmacologia , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Células Epiteliais , Epitélio/efeitos dos fármacos , Humanos , Glândula Tireoide/efeitos dos fármacos
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