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Résumé L'étude histologique et autoradiographique de glandes thyroïdes de Lérots à diverses périodes de l'année indique un fonctionnement réduit pendant la préhibernation et le maintien d'une certaine activité glandulaire en Décembre et Janvier, durant l'hibernation, s'accentuant fortement en Février et Mars avant le réveil et au cours de celui-ci; on note ultérieurement un retour à une activité modérée, cycle en accord avec les données biochimiques et isotopiques recueillies par Lachiver sur ces mêmes animaux.Cette stimulation liée à l'approche du réveil n'apparaît pas en Mars si l'hibernation est différée, l'animal étant maintenu en chambre froide jusqu'en Mai.L'aspect qualitatif de ces processus mérite aussi d'être envisagé: pendant l'hibernation et parfois avant celle-ci, on peut observer des autoradiogrammes avec un noircissement en anneau et non plus homogène, indiquant que seule la partie périphérique de la masse de thyroglobuline, en contact avec l'épithélium, participe au métabolisme des hormones, la zone centrale apparaissant peu active.Les cellules C sont toujours abondantes et volumineuses chez les Lérots en préhibernation et en hibernation; elles sont souvent dégranulées, parfois vacuolisées à la fin de celle-ci. Après le réveil et jusqu'en Juillet, elles deviennent plus petites, granulées et moins aisément identifiables avec certaines techniques. A une phase d'excrétion semble succéder une prépondérance des processus de synthèse et d'accumulation des granules.La mise en hypothermie profonde en Juillet induit leur réapparition en nombre élevé, leur hypertrophie et leur dégranulation partielle, des mitoses sont observées. De même, si l'hibernation est différée, ces cellules restent nombreuses et peu granulées jusqu'en Mai alors qu'elles régressent numériquement dès la fin Mars, quand le réveil a lieu.Deux espèces de Mammifères hibernants, originaires de Madagascar, ont aussi été étudiées: le Tenrec, qui est entré spontanément en léthargie en Juin-Juillet en France (hiver austral) et dont les cellules C sont extrêmement abondantes, volumineuses, peu granulées, et l'Ericulus, qui présente en Février, en France, des cellules C un peu moins nombreuses que le Tenrec, après une léthargie de plus courte durée. Un nombre élevé de cellules C actives s'observe dans la glande de Paraechinus en léthargie, en Février, l'animal provenant d'Afrique du Nord (région de Beni-Abbes).Chez la Marmotte, nous retrouvons une stimulation thyroïdienne lors du réveil, mais les cellules C ne sont jamais nombreuses dans la glande et les données actuelles ne permettent pas d'établir l'existence d'un cycle net.Les données bibliographiques sur les cellules C des hibernants sont comparées à celles recueillies sur le Lérot et discutées en fonction de l'état des glandes parathyroïdes et du métabolisme calcique au cours du cycle annuel. L'hypothèse d'une sécrétion de calcitonine par ces cellules semble probable, en liaison possible avec l'immobilité prolongée pendant le sommeil qui pourraît entraîner une décalcification osseuse.
Cytological and autoradiographic study of the thyroid gland in some hibernating mammals. Thyroid activity and presence of C cells (calcitonin cells)
Summary In the garden dormouse (Eliomys quercinus L.) a cyclic thyroid function was evidenced by histological and autoradiographic studies at various months of the year. The gland shows the maintenance of a low activity in December and January, before and during hibernation, greatly increased in February and March, preceding and accompanying the arousal; then, a slow return to a moderate activity is noted. This cycle is in agreement with biochemical data and radioiodine studies (Lachiver, 1952) on the same animals.When the hibernation is delayed and the animals are kept in a cold room until May, without food, the thyroid stimulation which naturally occurs at the time of arousal is simultaneously delayed.The qualitative aspect of these processes also needs to be investigated: during hibernation, and sometimes before it, the blackening of the photographic emulsion is not homogeneous above the colloid, the autoradiograms show several rings corresponding to the peripheral zone of the thyroglobulin at its junction with the epithelium. Only a thin rim seems to be participating in the hormonal metabolism, the central area being rather inactive.Abundant and large C cells, (calcitonin cells), always occur in the dormouse thyroid gland in prehibernation and hibernation, at the end of which they often appear degranulated, sometimes vacuolated. After the arousal, and until July, they become smaller, granulated, less easy to detect with light microscope only. After a period of excretion without storage during hibernation, a phase of synthesis and granule accumulation seems to occur.During experimental lethargy, with a low body temperature, induced in July, C cells reappear in large number; they are hypertrophied and partly degranulated, some mitoses are observed. Also, when hibernation is delayed, these cells remain numerous and lightly granulated until May, although normally their number is reduced by the end of March or the beginning of April, after dormouse arousal.Two hibernating mammals from Malghasia Republic were studied: 3 Tenrecs, Centetes ecaudatus, were spontaneously lethargic in July in France (austral winter). C cells were extremely abundant, voluminous, poorly granulated. In the Ericulus ericulus, from the same area, C cells were less numerous in February, in France, after a lethargy of a short duration. C cells appear numerous and active in the thyroid gland of a lethargic Paraechinus aethiopicus from North Africa (Beni-Abbes) in February.In the marmot (Marmota marmota) a thyroid stimulation also occurs around arousal, but C cells are not as numerous as in the other hibernating mammals, and a cyclic activity in the C cells seems difficult to demonstrate actually.Data from the literature on C cells of hibernating mammals are compared with results obtained on dormice and discussed in correlation with the condition of parathyroid glands and calcium metabolism during the annual cycle. The hypothesis of a secretion of calcitonin by C cells seems probable, perhaps in relation with a prolonged immobility during winter sleep which might induce a bone decalcification.
Nous adressons tous nos remerciements au Professeur M. Fontaine qui a bien voulu mettre à notre disposition ce matériel important et varié et Mr. F. Lachiver pour les documents qu'il nous a aimablement communiqués sur le comportement de ces animaux au Laboratoire de Physiologie du Muséum. Les espèces provenant de Madagascar et de Beni-Abbes ont été procurées au Pr Fontaine grâce à l'obligeance du Professeur F. Petter que nous remercions. Une partie du travail histologique a été réalisée avec la collaboration de Melle J. Olivereau, du CNRS, dont les excellentes techniques sont vivement appréciées.  相似文献   

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Les maladies auto-immunes thyro?diennes se présentent selon un large éventail de manifestations cliniques qui s’étend de l’hypothyro?die par atrophie thyro?dienne à l’hyperthyro?die par maladie de Basedow (tableau 1). Le but de cette revue est de préciser, à la lumière de données récentes, les indications et les méthodes des dosages utiles au diagnostic des maladies auto-immunes thyro?diennes.  相似文献   

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ObjectivesTo illustrate a case of intense uptake of 99mTc-MIBI on benign thyroid nodule and to recall the mechanisms of this uptake.Case presentationA patient of 25 years old had a parathyroid scintigraphy for suspected right lower parathyroid adenoma. The exam showed intense uptake of 99mTc-MIBI at the infero-lateral region of the right thyroid lobe. Low levels of PTH prompted to perform a thyroid scintigraphy for better diagnostic orientation. The scan revealed a large cold right basilobar thyroid nodule. The patient underwent a right loboisthmectomy. The histological analysis found a 3 cm diameter vesicular adenoma with oncocytic cells of the lower pole of right thyroid lobe.Discussion/conclusion99mTc-MIBI is used in the imaging of hyperparathyroidism. Radiotracer uptake is correlated to the parathyroid adenoma content in oxyphil cells. These cells are rich in mitochondria and retain the 99mTc-MIBI. This radiotracer can bind also on thyroid nodules. The specificity of this uptake for the diagnosis of malignancy is low. It is relevant to the nodule's wealth in oncocytic cells. These cells possess numerous mitochondria and can sequester 99mTc-MIBI like parathyroid oxyphil cells.  相似文献   

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《Médecine Nucléaire》2020,44(3):198-202
IntroductionThe Oncoflash® adaptive filtering algorithm is poorly validated in clinical practice. The objective of this study was to evaluate this algorithm efficacity in order to reduce injected activity or acquisition time on thyroid scintigraphy.MethodsOne hundred and five patients who received a thyroid scan have been tested. Three sets of images (conventional acquisition, gross half-time acquisition, post-processed half-time acquisition by Oncoflash®) were interpreted as open ultrasound and biological data without any view on their medical file and the patient's identity by 2 nuclear doctors. The concordance with the diagnosis retained in the medical file, the quality of the images and the inter-observer reproducibility were evaluated.ResultsNo significant differences were found in terms of agreement with the final diagnosis between post-processed Oncoflash® half-time images and conventional images (κ at 0.81 and 0.74 respectively). The quality of Oncoflash® half-time images was rated good or excellent in 90% of cases compared to 88.6% of cases for conventional acquisitions (P = 0.16). No significant difference in inter-observer agreement was found between the 3 sets of images compared two by two.ConclusionThese results suggest the possibility of using the Oncoflash® module in thyroid scintigraphy to reduce acquisition time or injected activity without impacting interpretation.  相似文献   

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Résumé On compare l'ultrastructure et la localisation des phosphatases acides au niveau des cellules hypophysaires delta et beta, chez des Cailles mâles thyroïdectomisées et maintenues en photopériode courte ou bien castrées, puis placées en photopériode longue. On étudie en outre, dans ces deux cas, les effets d'injections de doses croissantes de thyroxine.La thyroïdectomie provoque la transformation des cellules delta en cellules de thyroïdectomie groupées en îlots à la périphérie du lobe céphalique. Ces cellules sont pauvres en phosphatases acides. La thyroxine (10 g/j pendant 2 jours) provoque la régression de ces cellules et l'apparition de lysosomes. Les cellules beta ne sont pas modifiées par la thyroïdectomie.La castration-photostimulation stimule les cellules beta localisées dans le lobe céphalique. Elle provoque dans les deux lobes de la glande l'hypertrophie et la vacuolisation des cellules delta qui se distinguent des cellules de thyroïdectomie par la présence de nombreux lysosomes. La thyroxine freine simultanément l'activation des cellules delta et des cellules beta, en provoquant la formation de lysosomes, mais la dose efficace chez le mâle photostimulé (20 g et 60 g/j pendant 5 jours) est sans effet chez le castrat photostimulé (dose efficace 180 g/j).Pour interpréter ces faits, on admet que les cellules delta, thyréotropes et les cellules beta, gonadotropes, seraient simultanément soumises à un contrôle freinateur des hormones thyroïdiennes et des stéroïdes mâles.
Thyroidectomy cells and castration cells in the Japanese quail, Coturnix coturnix japonica Ultrastructure and cytoenzymology
Summary The ultrastructure and the localization of acid-phosphatase activity are compared in beta and delta pituitary cells of male Japanese quail, either thyroidectomized and maintained in short days, or castrated then put in long days. Moreover, in these two cases, the effects of brief treatments with increasing doses of thyroxine are studied.Thyroidectomy induces transformation of delta cells into thyroidectomy cells arranged in clumps at the periphery of the cephalic lobe. The acid-phosphatase activity of such cells is low. Thyroxine (10 g per day for two days) causes regression of these cells and the appearance of numerous lysosomes. Beta cells are not modified by thyroidectomy.Castration and exposure to long days stimulate beta cells, localized in the cephalic lobe. It induces, also, in both pituitary lobes, hypertrophy and vacuolization of delta cells which differ from thyroidectomy cells by the presence of numerous lysosomes.Thyroxine in photostimulated quail inhibits both delta- and beta-cell stimulation and increases the frequency of lysosomes but the effective doses on males (20 g or 60 g per day for five days) are inactive on castrates, the response of which is obtained with 180 g per day.In order to explain these data, a hypothesis is suggested: Thyrotropic delta cells and gonadotropic beta cells are both subject to a double inhibiting control by thyroid hormones and male steroids.
Nous remercions très vivement pour leur excellente collaboration technique Mme Renée Picart (préparation des tissus pour la microscopie électronique) et M. Claude Pennarun (photographe).  相似文献   

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Aromatase is the terminal enzyme responsible for estrogen biosynthesis; it is present in the endoplasmic reticulum membrane of steroidogenic cells in vertebrates. This enzyme functions with the ubiquitous reductase as the electron donor. The aromatase gene is unique and its expression is regulated in a tissue and more precisely in a cell-specific fashion via the alternative use of several promoters located in the first exons. This enzymatic complex is generally involved in development, reproduction, sexual differentiation and behaviour, but also in bone and lipid metabolism, brain functions and diseases such as breast and testicular tumors. The aromatase gene expression and its transduction in a fully active protein in testicular somatic cells and germ cells together with the widespread distribution of estrogen receptors (ERα & β) in the testis and the genital tract of the male, are clearly in favor of a physiological role for estrogens in the spermatogenesis processings especialy in sperm maturation. Therefore, we begin to understand the physiopathological roles of the estrogens in males indeed, the aromatase deficiency is associated, with severe bone maturation problems and sterility in man. Conversely, it is also obvious that estrogens in excess are responsible of the impaired spermatogenesis. These female hormones (or the ratio androgens/estrogens) do play a physiological role in the development and maintenance of male gonadal functions and obviously, several steps are concerned especially the sperm production and maturation.  相似文献   

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Differentiated thyroid cancer (DTC) is generally associated with a good prognosis. Local recurrences, mainly lymph-node involvement, account for 15–20% of cases and are surgically treated. Distant metastases, mostly in lungs and more rarely in bones, are present in 5% of patients. When iodine uptake is sufficient (in approximately 60% of patients), distant metastases can be destroyed by iterative activities of iodine 131. Serum thyroglobulin (Tg), which can be assessed either on hormonal treatment or on TSH stimulation is considered as the tumour marker in DTC. Functional (iodine 131 scintigraphy, FDG PET, bone scintigraphy) or anatomical (neck ultrasound, thoracic CT, bone MRI) imaging methods can be performed when Tg increases in order to show residual/recurrent disease. In recent years, new hybrid equipments integrating both a gamma camera and CT scan (SPECT/CT) have been commercialized while positron emission tomography cameras associated with CT (PET/CT) have been installed on the whole French territory. These equipments, which allow us to directly correlate functional and anatomical images, greatly improve the interpretation of planar scintigraphy or that of PET alone. Hybrid imaging enables us to precisely localize scintigraphic foci and most often, to immediately verify whether they correspond to tumour lesions. The aim of this article is to review the role of SPECT/CT and PET/CT in the management of patients with DTC in 2010.  相似文献   

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The role of reactive oxygen species in the physiopathology of human sperm function has been emphasized in recent years. Their production in semen has been associated with loss of motility, decreased capacity for spermoocyte fusion and loss of fertility. In semen preparations, there are two major sources of reactive oxygen species: leucocytes and spermatozoa themselve. It has been proposed that reactive oxygen species production by human spermatozoa was dependent upon a membrane-bound NADPH oxidase or a mitochondrial diaphorase. Hydrogen peroxide produced by the dismutation of superoxide anion has been recognized as the most toxic oxidizing species for human spermatozoa. Owing to their high content of polyunsaturated fatty acids, it has been proposed that lipid peroxidation of the sperm plasma membrane is largely responsible for defective sperm function. Reactive oxygen species also affect the sperm axoneme as a result of ATP depletion, inhibit mitochondrial functions, and synthesis of DNA, RNA and proteins, produce cytoskeletal modifications and inhibit sperm-oocyte fusion. Human spermatozoa possess enzymatic defence systems such as superoxide dismutase, glutathion peroxidas/reductase and catalase to counteract the toxic effects induced by reactive oxygen species. Correlations have been reported between their effectiveness and the duration of sperm motility. If the excessive production of reactive oxygen species is detrimental for human spermatozoa, they could also participate in the physiological function of the spermatozoa when present at low concentrations. Indeed, reactive oxygen species have been shown to be involved in the activation of several enzymes. Furthermore, sperm capacitation, acrosome reaction and sperm-zona interaction would be enhanced by reactive oxygen species.  相似文献   

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The differentiated thyroid carcinoma metastases concern habitually the lymphatic chains, the bone, the lung, and to a lesser degree the other organs. We report a rare case of gingival metastasis of differentiated thyroid carcinoma with bony invasion, in a 50 year-old patient, in whom the gingival metastasis revealed the thyroid carcinoma. Such extension follows a protracted course. Metastasis clinically appears years after the diagnostic of initial tumour. The lack of any specific sign, makes them to be mistaken for inflammatory or infectious pathologies. Their prognosis is in general good, if they are early and accurately diagnosed.  相似文献   

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Over the last fivty years, the risk factors for infertility have increased substantially, particularly those due to the environment. Spermatogenesis and spermatozoa can be affected by physical (ionizing radiation microwaves, heat, cryopreservation) or chemical agents (antimitotics drugs, antibiotics, tranquillizers, insecticides, pesticides, industrial solvants, some heavy metals, alcohol, cannabis etc.). Some natural factors, as stress or paternal age (ageing or very youthful age relatively to about thirty) also seems to affect spermatogenesis and, particularly, the age can be joined with the previous ones. On the whole, these factors are able to decrease the male fertility through some changes about the concentration, the motility or the morphology of spermatozoa and so it is possible to describe populations subject to the risk. Moreover, these spermatogenetic changes can lead abnormalities in progeny. For instance, some antimitotic drugs as cyclophosphamide, when administrated to the male rat, lead malformations or functional anomalies as behavioral troubles. The industrial solvents lead a decrease of the birth weight and the cannabis leads an increase of the ante-or post-natal death. Moreover, the change of the paternal spermatogenesis caused by cannabis can be found again in the male progeny. The problem is similar with the lead, the benzodiazepines and the alcohol. Concerning the physical factors, some authors have shown that the children born from radiation exposed fathers presented an increase of the probability of leukemia. In animal, the postimplantation loss is increased when the father is irradiated or subjected to heat before mating. Finally, the paternal ageing is responsible for new dominant autosomic mutations. Moreover, in animal and man, paternal ageing and, in man, very youthful age, also seems responsible for a gradual lowering in the level of progency cerebral functions. On the whole, these data should lead to an preventive attitude which would be more effective before about thirty years of age than after this period.  相似文献   

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D. Arsigny 《PSN》2008,6(4):205-214
This article aims to show that philosophy, particularly Epicureanism and Stoicism, had an essentially therapeutic role in antiquity — the various schools of philosophy dispensing specific teachings aimed at treating mental suffering, in a precise place (the scholé), with a master and a specified methodology. Of course, it may seem anachronistic to try and compare a modern, progressive and proven therapeutic method such as cognitive behavioural therapy (CBT, TCC in French) with a frequently dogmatic, 2000-year-old school of philosophy. And yet, the difference is not as clear-cut as we might think, since the two have much in common, such as similar kinds of suffering, a referent (or therapist), common methods (language, reasoning) and a common goal (peace of mind). We therefore intend to try and synthesise the meeting points and also the differences between two main schools of antique philosophy and CBT.  相似文献   

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Résumé La mesure précise in vivo de l'iode radioactif fixé par la thyroïde du Pigeon en fonction du temps après injection de 131I est délicate, en raison, d'une part, de la position anatomique de la thyroïde, d'autre part, de la masse des tissus juxtathyroïdiens, dont la radioactivité interfère avec celle de la glande.Nous avons conu un appareil de contention, qui, en immobilisant l'animal non anesthésié, permet de placer et de maintenir la glande dans une position identique par rapport au compteur, lors de chaque mesure.La radioactivité des tissus juxtathyroïdiens est évaluée à partir de celle d'une zone abdominale bien déterminée.La reproductibilité des mesures de radioactivité dans la zone thyroïdienne est comparable à celles d'autres méthodes d'étude in vivo chez les Mammifères. L'erreur effectuée sur la mesure de la radioactivité thyroïdienne, exprimée en % de la dose injectée, est en moyenne de 10%.  相似文献   

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