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1.
Am J Primatol ; 77(3): 338-45, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25328141

RESUMEN

When confronted with tasks involving reasoning instead of simple learning through trial and error, lemurs appeared to be less competent than simians. Our study aims to investigate lemurs' capability for transitive inference, a form of deductive reasoning in which the subject deduces logical conclusions from preliminary information. Transitive inference may have an adaptative function, especially in species living in large, complex social groups and is proposed to play a major role in rank estimation and establishment of dominance hierarchies. We proposed to test the capacities of reasoning using transitive inference in two species of lemurs, the brown lemur (Eulemur fulvus) and the black lemur (Eulemur macaco), both living in multimale-multifemale societies. For that purpose, we designed an original setup providing, for the first time in this kind of cognitive task, pictures of conspecifics' faces as stimuli. Subjects were trained to differentiate six photographs of unknown conspecifics named randomly from A to F to establish the order A > B > C > D > E > F and select consistently the highest-ranking photograph in five adjacent pairs AB, BC, CD, DE, and EF. Then lemurs were presented with the same adjacent pairs and three new and non-adjacent pairs BD, BE, CE. The results showed that all subjects correctly selected the highest-ranking photograph in every non-adjacent pair, reflecting lemurs' capacity for transitive inference. Our results are discussed in the context of the still debated current theories about the mechanisms underlying this specific capacity.


Asunto(s)
Cognición/fisiología , Aprendizaje/fisiología , Lemur/fisiología , Animales , Femenino , Masculino , Especificidad de la Especie
2.
Nat Genet ; 3(2): 157-64, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7684647

RESUMEN

Severely reduced fertility is a common finding in cystic fibrosis (CF). We used in situ hybridization to examine the cell-specific expression of CFTR in the reproductive organs of rodents. In males CFTR mRNA is found in the round spermatids (spermatogenic stages V-X) and in the principal cells that line the initial segment of the epididymis. In both the testis and the epididymis, CFTR expression is developmentally regulated suggesting that the defect in the genital tract of male CF patients is of developmental origin. CFTR expression in the luminal and glandular epithelium of the uterus is regulated during the oestrous cycle and is maximal at pro-oestrus. Our results provide a biological rationale for the reduced fertility of CF patients, and suggest a possible cause for the comparatively poorer prognosis for women with CF.


Asunto(s)
Fibrosis Quística/genética , Infertilidad/genética , Proteínas de la Membrana/genética , Animales , Fibrosis Quística/complicaciones , Fibrosis Quística/fisiopatología , Regulador de Conductancia de Transmembrana de Fibrosis Quística , Epidídimo/fisiopatología , Estro/genética , Estro/fisiología , Femenino , Regulación de la Expresión Génica , Hibridación in Situ , Infertilidad/etiología , Infertilidad/fisiopatología , Masculino , Proteínas de la Membrana/fisiología , Ratones , Sondas Moleculares , Ratas , Ratas Wistar , Epitelio Seminífero/fisiopatología , Espermatogénesis/genética
3.
AJNR Am J Neuroradiol ; 42(5): 969-974, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33766829

RESUMEN

BACKGROUND AND PURPOSE: MR imaging has a key role in predicting neurodevelopmental outcomes following neonatal hypoxic-ischemic encephalopathy (HIE). A novel MR imaging scoring system for hypoxic-ischemic brain injury was used in our patient population with the aim of assessing interobserver variability and developing subcategories for the severity of brain injury. MATERIALS AND METHODS: We evaluated brain MR images of 252 infants who underwent hypothermia for HIE between 2014 and 2019. First, 40 infants were selected randomly to test interobserver variability. Discrepancies were identified during the assessment of the first 20 MR images. The remaining 20 MR images were scored after adjusting the scoring system. Second, we determined cutoff values for the severity of injury that were based on the percentiles of the total scores in the full cohort. RESULTS: The interobserver reliability showed excellent agreement for the total score both before (intraclass correlation coefficient = 0.96; 95% CI 0.89-0.99) and after the adjustment (intraclass correlation coefficient = 0.96; 95% CI, 0.89-0.98). The average of the differences and the agreement interval between the 2 readers decreased after the adjustment. Subcategories of brain injury were the following: We considered a total score of ≤4 (≤75%) as normal, 5-10 (76%-90%) as mild, 11-15 (91%-95%) as moderate, and >15 (>95%) as severe brain injury. The agreement on the classification of brain injury improved in the second epoch (weighted κ = 0.723 versus 0.887). CONCLUSIONS: The adjusted scoring system may lead to a higher degree of interrater agreement. The presented cutoff values may be used to determine the severity of brain injury in future clinical studies including infants with mild hypoxia-ischemia.


Asunto(s)
Hipoxia-Isquemia Encefálica/diagnóstico por imagen , Hipoxia-Isquemia Encefálica/patología , Imagen por Resonancia Magnética/métodos , Estudios de Cohortes , Femenino , Humanos , Hipotermia Inducida , Hipoxia-Isquemia Encefálica/terapia , Recién Nacido , Masculino , Variaciones Dependientes del Observador , Pronóstico , Reproducibilidad de los Resultados
4.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 6553-6556, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31947343

RESUMEN

Magnetic Resonance Imaging (MRI) can provide 3D morphological information on brain structures. Such information is particularly relevant for carrying out morphometric brain analysis, especially in the newborn and in the case of prematurity. However, 3D neonatal MRI acquired in clinical environments are low-resolution, anisotropic images, making segmentation a challenging task. In this context, preprocessing techniques aim to increase the image resolution. Interpolation techniques were classically used; super-resolution (SR) techniques have recently appeared as an emerging alternative. In this paper, we evaluate the performance of different SR methods against the classical interpolation in the application of neonatal cortex segmentation. Additionally, we assess the robustness of different segmentation methods for each estimation of high resolution MRI input. Results are evaluated both qualitatively and quantitatively with neonatal clinical MRI.


Asunto(s)
Algoritmos , Imagen por Resonancia Magnética , Anisotropía , Encéfalo , Humanos , Recién Nacido , Manejo de Especímenes
5.
Behav Processes ; 77(3): 320-6, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17766057

RESUMEN

Self-medicative behaviours have been largely documented in vertebrates and, in particular, the use of plants for pharmacological purposes has been mainly reported in primates. White-faced capuchins are known to rub specifically chosen plants and other substances on their fur. To better understand the mechanisms underlying this phenomenon and investigate the influence of different plant resources on the form of fur rubbing activity, we conducted experiments using different randomly selected plant items: oranges and onions. We found that (1) capuchins showed different degrees of interest in the materials used to fur rub; (2) the mean group dynamics differ drastically according to the resource supplied; and (3) individuals present strong differences in their social behaviour, i.e. they spent more or less time fur rubbing in spatial proximity of conspecifics according to the material used for fur rubbing. We propose hypotheses on possible proximal causes for these differences and highlight that some precautions have to be taken in behavioural studies including only one resource type.


Asunto(s)
Cebus/psicología , Conducta de Elección , Aseo Animal , Conducta Social , Animales , Baños , Citrus , Conducta Exploratoria , Femenino , Masculino , Cebollas , Plantas Medicinales , Automedicación , Medio Social , Estadísticas no Paramétricas
6.
Mol Endocrinol ; 1(8): 561-8, 1987 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-3153478

RESUMEN

Inhibin is a gonadal protein hormone that suppresses the secretion of FSH from pituitary gonadotrophs. It has previously been characterized as a heterodimer of two dissimilar subunits (alpha, 18 kilodaltons and beta, 14 kilodaltons) the smaller of which exists in two forms (beta A and beta B) and can form dimers that stimulate the secretion of FSH. In the present work, cDNA clones encoding the inhibin alpha- and beta A-subunits have been isolated from rat ovary and characterized. The alpha-inhibin cDNA predicts a precursor protein of 366 amino acids containing the 133 amino acid mature alpha-subunit at its COOH-terminus. The beta A-inhibin cDNA predicts a precursor protein of 424 amino acids containing the 116 amino acid beta A-subunit at its COOH-terminus. Analysis of rat ovarian RNA indicates that alpha-inhibin mRNA levels are stimulated by PMSG treatment in vivo. In cultured granulosa cells, FSH also stimulates alpha-inhibin mRNA, and the FSH effect is suppressed by cotreatment with GnRH. Hybridization in situ to rat ovarian tissue demonstrates that both the alpha-inhibin and beta A-inhibin mRNAs are specifically expressed in granulosa cells of the developing follicles.


Asunto(s)
Células de la Granulosa/metabolismo , Inhibinas/genética , Fragmentos de Péptidos/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Células Cultivadas , Clonación Molecular , ADN/genética , Femenino , Datos de Secuencia Molecular , ARN Mensajero/biosíntesis , Ratas , Ratas Endogámicas
7.
Mol Endocrinol ; 3(12): 2062-9, 1989 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2628740

RESUMEN

Immature female rats were treated with PMSG and human CG to induce ovulation. Sequential treatment with these hormones allowed us to investigate variations in the production of inhibin subunits shortly before ovulation and during the induced luteal phase. Using this model, we found that expression patterns for the alpha-, beta A-, and beta B-subunits were similar to those observed in mature cycling animals: administration of PMSG (to mimic the gonadotropin surge) led to a sharp increase in the expression of all three subunits in large preovulatory follicles whereas injection with human CG (to induce ovulation) caused a decrease in the levels of the respective mRNAs. In contrast to mature females, shortly before ovulation, levels of inhibin alpha-subunit mRNA were low in small antral follicles (approximately 350 microns). In addition, at that time, inhibin beta A- and beta B-subunits mRNAs were present in several large follicles (greater than 500 microns). More than 2 days after ovulation, inhibin beta A- and beta B-subunit mRNAs could not be detected in small antral size follicles (approximately 350 microns) of hormonally induced females. On the other hand, hybridization signals for the inhibin alpha-subunit were observed in some small antral and preantral size follicles, while signals were very low or undetectable in a large number of atretic follicles. Using this synchronized ovulation model, hybridization patterns for inhibin beta A-subunit mRNA was observed in interstitial cells, 8-10 h after ovulation.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Gonadotropinas/farmacología , Inhibinas/genética , Folículo Ovárico/metabolismo , Ovulación , Animales , Gonadotropina Coriónica/farmacología , Femenino , Expresión Génica , Gonadotropinas Equinas/farmacología , Fase Luteínica , Modelos Biológicos , Folículo Ovárico/efectos de los fármacos , Conformación Proteica , ARN Mensajero/metabolismo , Ratas
8.
Mol Endocrinol ; 2(12): 1352-63, 1988 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3146021

RESUMEN

Distributions of inhibin alpha-, beta A-, and beta B-subunits in different ovarian compartments were studied in cycling female rats by in situ hybridization with complementary RNA probes and using immunohistochemical localization with antibodies selective for each inhibin subunit. Consistent with earlier studies showing inhibin production by granulosa cells of maturing follicles, we also detected mRNAs for inhibin alpha-, beta A-, and beta B-subunits in granulosa cells of these follicles. However, based on immunohistochemistry and in situ hybridization, we found that inhibin alpha- is not only expressed in granulosa cells of mature follicles but in follicles at all stages of maturation, including primary to tertiary follicles. A number of primordial follicles also contained alpha mRNA and immunodetectable alpha-subunit. Interestingly, theca interna and interstitial gland cells contained inhibin alpha mRNA and alpha-subunit. Low levels of inhibin alpha immunoreactivity as well as specific hybridization to the complementary inhibin alpha mRNA probe were observed in newly formed luteal tissue. beta-Subunits, on the other hand, were detected exclusively in granulosa cells of healthy tertiary follicles. The changes in expression of inhibin alpha-, beta A-, and beta B-subunits were more pronounced during the follicular phase of the cycle: inhibin alpha reached its highest level in granulosa cells, theca interna, and interstitial gland cells a few hours after the LH/FSH surge, while at the same time the beta-subunits decreased dramatically in granulosa cells of mature follicles. Immediately before ovulation (estrus 0200 h), the alpha-subunit sharply declined in preovulatory follicles and was present mainly in granulosa cells from nonovulatory follicles at various stages of maturation. At that time, the beta A- and beta B-subunits could not be detected in preovulatory follicles but were localized mainly in small tertiary follicles (less than 300 microns). Unlike for the alpha- and beta B-subunits, beta A mRNA and immunoreactivity was present in large tertiary follicles (approximately 600 microns) immediately before ovulation. The present findings support the hypothesis that a decrease in inhibin production could be responsible for the secondary FSH surge observed early on estrus. This could be initiated by a change in the ratios of activin-inhibin production by decreasing first, the levels of beta-subunits, second, the levels of alpha-subunit, and third, by a resurgence of activin A produced mainly by granulosa cells from large tertiary follicles.(ABSTRACT TRUNCATED AT 400 WORDS)


Asunto(s)
Estro/fisiología , Inhibinas/genética , Ovario/citología , Animales , Femenino , Hormona Folículo Estimulante/metabolismo , Regulación de la Expresión Génica , Inmunohistoquímica , Inhibinas/análisis , Inhibinas/metabolismo , Ovario/análisis , Ovario/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas
9.
Endocrinology ; 111(3): 857-62, 1982 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6179767

RESUMEN

When present alone for 4 or 8 days, 5 alpha-dihydrotestosterone (DHT) or the pure progestin R5020 (17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione) inhibits spontaneous PRL release by 33--50% in rat anterior pituitary cells in primary culture. This inhibitory effect of DHT and R5020 can only be partially reversed by 17 beta-estradiol (E alpha). DHT and R5020 inhibit spontaneous PRL release in E2-primed cells at ED50 values of 0.5 and 3 nM, respectively. While E2 diminishes by 30--60% the maximal inhibitory effect of dopamine on PRL release and increases by 10-fold the ED50 value of dopamine action, DHT and R5020 can prevent by 30--60% the action of E2 and thus increase the potency of dopamine to inhibit PRL release. The inhibitory action of DHT and R5020 as well as the stimulatory action of E2 on spontaneous PRL release are similarly expressed on TRH- and 3-isobutyl-1-methylxanthine-induced PRL release, thus suggesting that at least part of the highly effective modulatory effects of sex steroids are exerted at a step after cAMP formation.


Asunto(s)
1-Metil-3-Isobutilxantina/farmacología , Dopamina/farmacología , Hormonas Esteroides Gonadales/farmacología , Adenohipófisis/metabolismo , Prolactina/metabolismo , Teofilina/análogos & derivados , Hormona Liberadora de Tirotropina/farmacología , Animales , Dihidrotestosterona/farmacología , Interacciones Farmacológicas , Estradiol/farmacología , Femenino , Adenohipófisis/efectos de los fármacos , Promegestona/farmacología , Ratas
10.
Endocrinology ; 125(5): 2350-9, 1989 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-2676482

RESUMEN

The distributions of the alpha-, beta A-, and beta B subunits of inhibin/activin polypeptides were studied in the testis of adult (60-day-old) and immature (12-day-old) rats. Immunohistochemical techniques using antisera selective for each subunit were used to localize the polypeptide chains. In situ hybridization using radiolabeled complementary RNA probes enabled localization of the messenger RNAs (mRNAs) encoding these subunits. In 12-day-old rats, immunostaining and mRNA signal for the alpha-subunit was found in Leydig cell clusters. The beta A- and beta B-subunit staining and beta A-subunit message were detectable in isolated interstitial cells, but the clusters appeared to lack these subunits. Positive immunostaining for each subunit was localized in a Sertoli cell-like pattern in seminiferous tubules, as was a positive mRNA signal for the alpha- and beta B-subunit over regions containing these cell types. Treatment with human CG (hCG) and PMSG greatly enhanced the production of the alpha-subunit in the Leydig cell clusters, but not within the tubules, of these young rats. In adult rats, alpha- and beta B-subunit staining, and alpha-subunit mRNA signal, was observed in the interstitial cells. As in the immature animals, all three subunits were localized in a Sertoli cell-like pattern in the tubules, and a positive mRNA signal for the alpha- and beta B-subunits was found over these cells. There was, however, no obvious change in the expression of the subunits in the testis of adult rats after gonadotropin treatment. The present findings suggest that: 1) in the rat testis, both Sertoli and interstitial cells produce inhibin/activin subunits; 2) the alpha- and beta-subunits are produced by different types of interstitial cells in immature rats; and 3) the production of the alpha-subunit in the Leydig cells of immature rats is regulated by LH-like hormones.


Asunto(s)
Regulación de la Expresión Génica , Inhibinas/biosíntesis , Testículo/crecimiento & desarrollo , Animales , Técnica del Anticuerpo Fluorescente , Sueros Inmunes , Inhibinas/genética , Células Intersticiales del Testículo/metabolismo , Sustancias Macromoleculares , Masculino , Hibridación de Ácido Nucleico , ARN Mensajero/análisis , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Ratas , Ratas Endogámicas , Células de Sertoli/metabolismo , Maduración Sexual , Testículo/citología , Testículo/metabolismo
11.
Endocrinology ; 124(1): 552-4, 1989 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-2535814

RESUMEN

Two related proteins, inhibin and activin, are produced and secreted by the gonads and act at the pituitary to regulate FSH secretion. In the present study, the alpha and beta B, but not the beta A, polypeptide subunits of inhibin were localized in the cytoplasm of FSH- and LH-immunoreactive (ir) gonadotropes. Ovariectomy (OVX) increased the size and number of cells immunoreactive for inhibin-alpha and -beta B as well as the mRNAs encoding these subunits. Treatment with estrogen prevented these effects. These results suggest that pituitary gonadotropes are sources, as well as targets, of inhibin-related peptides, whose expression in the pituitary is modulated by ovarian factors.


Asunto(s)
Hormona Folículo Estimulante/metabolismo , Inhibinas/biosíntesis , Hormona Luteinizante/metabolismo , Adenohipófisis/metabolismo , Animales , Citoplasma/metabolismo , Endonucleasas , Femenino , Técnica del Anticuerpo Fluorescente , Inhibinas/genética , Sustancias Macromoleculares , Masculino , Orquiectomía , Ovariectomía , ARN Mensajero/metabolismo , Ratas , Ratas Endogámicas , Endonucleasas Específicas del ADN y ARN con un Solo Filamento
12.
J Clin Endocrinol Metab ; 71(2): 487-92, 1990 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2199480

RESUMEN

A growing number of studies provided the evidence that human decidua is a pregnancy-related tissue capable of hormone production and metabolism. The aim of the present study was to evaluate the possible presence of inhibin subunits in human decidua. Tissue samples were collected in pregnant women during the first (8 weeks) and second trimester (18 weeks) of gestation and at term (40 weeks). Immunohistochemical data were obtained using affinity purified polyclonal antisera raised in rabbit against porcine alpha, beta A, or beta B subunits. Levels of the respective inhibin subunits were evaluated by Northern blot analysis using cDNA probes encoding sequences corresponding to each subunit. The present results indicated that human decidua contains and synthesizes inhibin alpha, beta A, and beta B subunits. The immunohistochemical data showed that decidual cells were stained with both inhibin alpha and beta B antisera, showing a similar localization. On the other hand, cells stained with inhibin beta A antisera were sparse and followed a distribution pattern different from that of cells stained with alpha or beta B antisera. The first inhibin alpha and beta B subunit mRNAs were both expressed in first trimester of pregnancy, and those mRNA levels showed a gestational related increase. The beta A subunit mRNA was expressed at very low levels at term and could not be detected earlier during pregnancy. The present data showed that human decidua actively produces inhibin subunits with a gestational-related profile. The results suggest that decidua may be a further source of inhibin-related proteins during pregnancy and emphasize the endocrine competence of human decidua.


Asunto(s)
Decidua/metabolismo , Inhibinas/análisis , Aborto Espontáneo , Northern Blotting , Cesárea , Decidua/citología , Femenino , Técnica del Anticuerpo Fluorescente , Expresión Génica , Humanos , Inhibinas/biosíntesis , Inhibinas/genética , Sustancias Macromoleculares , Embarazo , Primer Trimestre del Embarazo , ARN Mensajero/análisis , ARN Mensajero/genética , Valores de Referencia
13.
J Comp Neurol ; 364(3): 473-493, 1996 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-8820878

RESUMEN

Inhibin and activin are best known as gonadal glycoprotein hormones but have a broad anatomical distribution. We previously described the central distribution ofinhibin/activin beta A- and beta B-subunit proteins in some neuronal cell bodies, fibers, and nuclei of the rat brain and reported a possible role for central activin in suckling-induced oxytocin secretion and corticotropin releasing factor release. In the present report, we mapped the detailed immunohistochemical localization of inhibin/activin alpha-, beta A-, and beta B-subunits throughout the rat brain to further clarify their central distribution. In addition, the localization and distribution of their corresponding mRNAs was assessed. The results are summarized as follows: 1) Both beta A- and beta B-subunit immunoreactivity are found in neuronal cell bodies in the nucleus of the solitary tract and the dorsal and ventral medullary reticular nuclei, and in fibers and terminals of known projection sites for these nuclei. 2) beta B-subunit immunoreactivity is localized in a group of perifornical neurons in the hypothalamus. 3) beta A-subunit immunoreactivity is present in discrete populations of neuronal cell nuclei scattered throughout the CNS. 4) mRNAs encoding each of the inhibin/activin subunits are expressed in all major brain regions as determined by S1 nuclease assay and in a variety of specific neuroanatomical sites as shown by in situ hybridization. The results suggest that central inhibin and activin proteins are produced in the brain where they may potentially serve inter- and intracellular functions in multiple systems.


Asunto(s)
Química Encefálica/fisiología , Inhibinas/metabolismo , ARN Mensajero/metabolismo , Activinas , Animales , Encéfalo/anatomía & histología , Femenino , Inmunohistoquímica , Hibridación in Situ , Masculino , Sondas ARN , Ratas , Ratas Sprague-Dawley , Endonucleasas Específicas del ADN y ARN con un Solo Filamento/análisis
14.
J Nucl Med ; 21(9): 844-5, 1980 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-6967958

RESUMEN

The site of active intermittent gastrointestinal (GI) bleeding could not be found in a patient until abdominal scintigrams with indium-111-labeled red cells suggested that the bleeding was in the ascending colon. Right hemicolectomy abolished the hemorrhages. The binding of In-111 to the red cell is such that vascular activity could be clearly seen over a 5-day period. Indium-111-labeled red cells might provide an excellent tracer to locate intermittent active GI bleeding.


Asunto(s)
Eritrocitos , Hemorragia Gastrointestinal/diagnóstico por imagen , Indio , Radioisótopos , Anciano , Enfermedades del Colon/diagnóstico por imagen , Semivida , Humanos , Marcaje Isotópico , Masculino , Cintigrafía
15.
Mol Cell Endocrinol ; 30(3): 347-51, 1983 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-6602723

RESUMEN

Ovine corticotropin-releasing factor (CRF) stimulates adenylate cyclase activity in homogenate of the intermediate lobe of the bovine pituitary gland at an ED50 value of 150 nM. GTP increases the stimulatory effect induced by CRF as well as by the beta-adrenergic agonist isoproterenol on [32P]cyclic AMP formation in rat pars intermedia homogenate. In addition, GTP is required for inhibition by dopamine of the stimulatory action of both CRF and isoproterenol. The present data show that CRF stimulates adenylate cyclase activity in the intermediate lobe of the pituitary gland at least partly through a GTP-dependent mechanism. Moreover, dopamine can interfere with the action of CRF as well as that of isoproterenol, thus indicating that the neurohormone could be involved, in addition to beta-adrenergic agents, as stimulator of pars intermedia cell activity.


Asunto(s)
Adenilil Ciclasas/análisis , Hormona Liberadora de Corticotropina/farmacología , Hipófisis/enzimología , Animales , Bovinos , Guanosina Trifosfato/farmacología , Isoproterenol/farmacología
16.
Eur J Pharmacol ; 81(3): 411-20, 1982 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-6288411

RESUMEN

Changes of cyclic AMP levels were used to assess the specificity of the beta-adrenergic receptor in primary cultures of cells prepared from the intermediate lobe of rat pituitary gland. During a 4 min incubation, beta-adrenergic agonists led to a 4 to 6 fold stimulation of cyclic AMP concentration with the following order of potency (Kd values): zinterol (0.75 nM) greater than hydroxybenzylisoproterenol (1.0 nM) greater than (--)-isoproterenol (4.6 nM) greater than soterenol greater than (7.7 nM) greater than (--)-epinephrine (10 nM) greater than OPC 2009 (procaterol, 11 nM) much greater than (--)-norepinephrine (300 nM). The potent antagonists cyanopindolol, (--)-propranolol and hydroxybenzylpindolol reversed the stimulatory effect of (--)-isoproterenol at Kd values of 0.4-0.6 nM. Other beta-adrenergic antagonists had the following order of potency: pindolol = (--)-alprenolol = timolol (0.9-1.0 mM) much greater than metoprolol (100 nM) greater than dichloroisoproterenol (300 nM) greater than butoxamine (1100 nM). The beta 1-selective antagonist practolol had a low potency at 700 nM. The stereoselectivity of the receptor is indicated by the 400 to 70 fold higher potency of the (--)-isomers of isoproterenol, epinephrine and propranolol as compared to their (+)-stereoisomers. The data show that the beta-adrenergic receptor in the intermediate lobe of the rat pituitary gland is mainly of the bet 2-subtype. Study of this pure population of postsynaptic beta-adrenergic receptors where binding could be correlated with other parameters of cellular activity (cyclic AMP formation and alpha-MSH secretion) should yield useful information about the less accessible adrenergic systems of the brain.


Asunto(s)
AMP Cíclico/metabolismo , Hipófisis/metabolismo , Receptores Adrenérgicos beta/metabolismo , Receptores Adrenérgicos/metabolismo , Animales , Epinefrina/farmacología , Femenino , Isoproterenol/farmacología , Hormonas Estimuladoras de los Melanocitos/sangre , Norepinefrina/farmacología , Propranolol/farmacología , Ratas , Ratas Endogámicas , Factores de Tiempo
17.
Artículo en Inglés | MEDLINE | ID: mdl-6298887

RESUMEN

1. A pure population of pars intermedia cells in primary culture was used to study changes in alpha-MSH secretion and cyclic AMP accumulation. 2. Beta-adrenergic agonists and CRF (corticotropin-releasing factor) stimulate alpha-MSH secretion and cyclic AMP accumulation. 3. Dopaminergic agonists inhibit basal as well as (-)isoproterenol- and CRF-induced alpha-MSH secretion and cyclic AMP accumulation. 4. Beta-adrenergic, dopaminergic and CRF receptors regulate pars intermedia cell activity probably through the adenylate cyclase system.


Asunto(s)
Hormona Adrenocorticotrópica/fisiología , Hormonas Estimuladoras de los Melanocitos/metabolismo , Fragmentos de Péptidos/fisiología , Hipófisis/fisiología , Receptores Adrenérgicos beta/fisiología , Receptores Adrenérgicos/fisiología , Receptores Dopaminérgicos/fisiología , Animales , Péptido de la Porción Intermedia de la Adenohipófisis Similar a la Corticotropina , Técnicas de Cultivo , AMP Cíclico/metabolismo , Femenino , Ratas , Ratas Endogámicas
18.
Life Sci ; 30(11): 963-8, 1982 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-6122149

RESUMEN

The potency of a series of drugs to inhibit cyclic AMP accumulation in cells of the intermediate lobe of the rat pituitary gland in culture is typically dopaminergic. Dopaminergic antagonists reverse the inhibition of cyclic AMP levels according to their known pharmacological activity. The present data show that activation of the dopamine receptor in pars intermedia cells leads to inhibition of basal cyclic AMP accumulation and thus suggest that this receptor is negatively coupled to adenylate cyclase.


Asunto(s)
Adenilil Ciclasas/fisiología , Hipófisis/fisiología , Receptores Dopaminérgicos/fisiología , Animales , Antipsicóticos/farmacología , AMP Cíclico/análisis , Dopamina/farmacología , Femenino , Hormonas Estimuladoras de los Melanocitos/metabolismo , Ratas , Ratas Endogámicas
19.
Clin Exp Rheumatol ; 5(2): 143-6, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3301124

RESUMEN

Thirteen cases of pustulotic arthro-osteitis are reported: 3 children and 10 adults. The clinical and radiological aspects of this rare entity are discussed as well as the classification of this disease in the context of seronegative spondyloarthropathies.


Asunto(s)
Artritis/diagnóstico por imagen , Infecciones Bacterianas/etiología , Osteítis/diagnóstico por imagen , Enfermedades Cutáneas Vesiculoampollosas/etiología , Adulto , Artritis/complicaciones , Niño , Dermatosis del Pie/etiología , Dermatosis de la Mano/etiología , Humanos , Osteítis/complicaciones , Osteomielitis/complicaciones , Osteomielitis/diagnóstico por imagen , Radiografía , Supuración/etiología , Síndrome
20.
Radiat Prot Dosimetry ; 99(1-4): 47-8, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12194356

RESUMEN

The structure of the survival curve of melanoma cells irradiated by 14 MeV neutrons displays unusual features at very low dose rate where a marked increase in cell killings at 0.05 Gy is followed by a plateau for survival from 0.1 to 0.32 Gy. In parallel a simulation code was constructed for the interaction of 14 MeV neutrons with cellular cultures. The code describes the interaction of the neutrons with the atomic nuclei of the cellular medium and of the external medium (flask culture and culture medium), and is used to compute the deposited energy into the cell volume. It was found that the large energy transfer events associated with heavy charged recoils can occur and that a large part of the energy deposition events are due to recoil protons emitted from the external medium. It is suggested that such events could partially explain the experimental results.


Asunto(s)
Supervivencia Celular/efectos de la radiación , Neutrones , Simulación por Computador , Relación Dosis-Respuesta en la Radiación , Humanos , Melanoma , Radiometría/métodos , Dispersión de Radiación , Células Tumorales Cultivadas
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