RESUMO
For nearly 50 years, the strategy of screening and the diagnostic criteria for gestational diabetes have been the subject of endless controversies. They differ between countries and from one center to another, mainly because of the lack of hard data allowing to define glycemic thresholds at which a therapeutic management is needed. Recently, a large observational study has demonstrated the existence of a robust relationship between maternal blood sugar and several fetomaternal perinatal complications. This relationship is linear, with no clear threshold that would define gestational diabetes unambiguously. Meanwhile, two randomized intervention trials have shown that the therapeutic management of mild gestational diabetes was associated with improved perinatal outcomes. Based on these data, the "International Association of Diabetes and Pregnancy Study Group" (IADPSG) released new recommendations on screening methods and diagnostic criteria for gestational diabetes. Although already endorsed by several international associations and implemented in some countries, these recommendations still raise questions and criticisms. This is why the "Groupement des Gynécologues Obstétriciens de Langue Française de Belgique" (GGOLFB) organized a meeting between diabetologists and gynecologists which allowed to reach a consensus on the strategy that we intend to implement in our respective centers. The purpose of this paper is to briefly overview the recent advances in gestational diabetes and more particularly to make our key conclusions known to the medical community. This will enable the standardization of the management of gestational diabetes in the French-speaking part of Belgium.
Assuntos
Diabetes Gestacional/diagnóstico , Conferências de Consenso como Assunto , Diabetes Gestacional/terapia , Feminino , Humanos , Programas de Rastreamento , Gravidez , Sociedades MédicasRESUMO
For nearly 50 years, the strategy of screening and the diagnostic criteria for gestational diabetes have been the subject of endless controversies. They differ between countries and from one center to another, mainly because of the lack of hard data allowing to define glycemic thresholds at which a therapeutic management is needed. Recently, a large observational study has demonstrated the existence of a robust relationship between maternal blood sugar and several fetomaternal perinatal complications. This relationship is linear, with no clear threshold that would define gestational diabetes unambiguously. Meanwhile, two randomized intervention trials have shown that the therapeutic management of mild gestational diabetes was associated with improved perinatal outcomes. Based on these data, the " International Association of Diabetes and Pregnancy Study Group "(IADPSG) released new recommendations on screening methods and diagnostic criteria for gestational diabetes. Although already endorsed by several international associations and implemented in some countries, these recommendations still raise questions and criticisms. This is why the "Groupement des Gynécologues Obstétriciens de Langue Française de Belgique " (GGOLFB) organized a meeting between diabetologists and gynecologists which allowed to reach a consensus on the strategy that we intend to implement in our respective centers. The purpose of this paper is to briefly overview the recent advances in gestational diabetes and more particularly to make our key conclusions known to the medical community. This will enable the standardization of the management of gestational diabetes in the French-speaking part of Belgium.
Assuntos
Diabetes Gestacional/diagnóstico , Conferências de Consenso como Assunto , Feminino , Humanos , Programas de Rastreamento , Gravidez , Resultado da GravidezRESUMO
Acromegaly is a rare hormonal disease related to excessive growth hormone secretion. It can result in a range of complications, including cardiovascular, respiratory, metabolic, articular and neoplastic disorders. Among patients with the condition, obstructive sleep apnea syndrome occurs frequently and the effect of treatment is inconstant: improvement, statu quo or deterioration can be observed. We here report three clinical cases, which illustrate the unpredictable evolution of this condition.
Assuntos
Acromegalia/terapia , Síndromes da Apneia do Sono/reabilitação , Acromegalia/complicações , Adenoma/complicações , Adenoma/cirurgia , Adulto , Ritmo Circadiano , Pressão Positiva Contínua nas Vias Aéreas , Feminino , Adenoma Hipofisário Secretor de Hormônio do Crescimento/complicações , Adenoma Hipofisário Secretor de Hormônio do Crescimento/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Polissonografia , Síndromes da Apneia do Sono/complicações , Resultado do TratamentoRESUMO
Delayed morphological changes induced in mouse hyperplastic thyroid by refeeding iodine were analyzed by light and electron microscopy, stereology, and autoradiography. Thyroid hyperplasia was induced by a low iodine diet supplemented with 0.25% propylthiouracil for 10 days. Involution was obtained by discontinuing the propylthiouracil and returning either to a moderate iodine diet [(MID) 1 microgram I/day] or to an iodine-rich diet [(HID) 10 micrograms I/day] for 40 days. In other experiments, three cycles of hyperplasia (8 days) and subsequent involution (8 days) with MID or HID were brought about. Control animals were fed MID or HID. All animals were killed when 12-14 weeks old after injection of 10-50 microCi 125I. Double labeling, with repeated injections of [3H]thymidine from day 0 to day 7 of involution followed by 125I injection 4 h before killing, was also performed. When involutions were performed with MID, most morphological variables returned to control values. However, when involution was brought about with HID, the glandular weight, the number of follicles, and the relative volume of follicular lumina remained larger than in controls. Moreover, the 125I-labeling pattern of the follicles was altered. The proportions of unlabeled, and unevenly or partly labeled, follicles, which were fewer than 5% in control groups, represented 25-35% of all follicles after involution with HID, whereas they were unchanged with MID. In unlabeled follicles the epithelium was flattened, with a reduced number of microvilli. Partly labeled follicles were of two types. In some follicles a persistent ring reaction was observed, suggesting an abnormally slow mixing of thyroglobulin. In others, the 125I labeling was restricted to areas adjacent to the apex of a reduced number of cells, suggesting that some cells were iodinating thyroglobulin, whereas others were not. There was no relationship between the follicular 125I labeling and the frequency of [3H]thymidine-labeled cells. These results indicate that refeeding iodine excess after hyperplasia leads to the formation of a colloid goiter with new follicles, and to an increased heterogeneity of iodine metabolism among follicles and among cells.
Assuntos
Bócio/patologia , Iodo/farmacologia , Glândula Tireoide/patologia , Animais , Citoplasma/patologia , Retículo Endoplasmático/patologia , Epitélio/patologia , Feminino , Bócio/etiologia , Bócio/metabolismo , Hiperplasia , Iodo/administração & dosagem , Iodo/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Microscopia Eletrônica , Microvilosidades/patologia , Tamanho do Órgão , Propiltiouracila , Glândula Tireoide/metabolismoRESUMO
Involution of thyroid hyperplasia was induced in C3H mice by discontinuing a goitrogenic treatment (low iodine diet supplemented with 0.25% propylthiouracil) and refeeding a normal iodine diet. Thyroid involution was studied by morphological, histochemical, autoradiographic, and stereological methods. The onset of the involution was characterized by an early accumulation of colloid, the presence of necrotic cells in the follicular lumina, and the appearance of homogeneous microcavities in the epithelial layers. The intraepithelial microcavities had the same morphological and functional properties as the follicular lumina. They were limited by a membrane covered with microvilli; polysaccharides and peroxidase activity were detected on their membranes, and 125I-labeling was marked in their lumina. Thin serial sections demonstrated that the microlumens originated from the intercellular space; plasma membranes differentiated into junctional complexes, and a narrow lumen limited by a membrane covered with short microvilli was formed in the intercellular space between the junctions. Later on, the newly formed microlumens fused to form new follicles with a cloverleaf pattern. As a consequence of the folliculogenesis, the total number of follicles doubled after 8 days of involution. This increase in number was mainly due to the presence of a population of small follicles. The folliculogenesis was associated in the first 4 days of involution with an active cellular multiplication which compensated for the early cell necrosis and led to a doubled number of epithelial cells. The increase in the total number of follicles and cells could partially explain the persistence of a relatively high thyroid weight after involution of hyperplasia.
Assuntos
Glândula Tireoide/patologia , Animais , Feminino , Hiperplasia , Iodo/deficiência , Camundongos , Camundongos Endogâmicos C3H , Propiltiouracila/farmacologia , Glândula Tireoide/efeitos dos fármacos , Fatores de TempoRESUMO
Snell-type dwarf mice were injected with TSH, GH, or both hormones together for 6 days. GH induced an increase in body weight but not in the weight of the thyroid gland itself; on the contrary, TSH caused an increase in the weight of the thyroid but no increase in body weight. After TSH injection, the relative volume of the thyroid parenchyme was enhanced by 45% compared to that in untreated dwarf mice, and the radius of the follicles and follicular lumina increased by 50% and 48%, respectively. The major effect of TSH was an increase in cellular volume (+93%), and the mean number of cells in the average follicle was doubled, without a reduction in the number of follicles. GH had almost the same effect as TSH on the relative volume of the parenchyme and caused the radius of follicles and of the follicular lumina to increase by 61% and 69%, respectively. However, GH did not influence cellular volume. Its primary effect was to stimulate cellular division (cells were increased about 5 times in the average follicle) and to reduce the number of follicles. The nucleo-cytoplasmic ratio increased with GH but decreased with TSH. T4 serum levels increased to a much lesser extent with GH than with TSH, while normal values were obtained with both hormones together. At a morphological level, the combined administration of TSH and GH produced the same qualitative effects as separate administration, inducing an increase in cell volume and number which was less than the sum of the effects of each hormone administered separately.
Assuntos
Nanismo/fisiopatologia , Hormônio do Crescimento/farmacologia , Glândula Tireoide/fisiopatologia , Tireotropina/farmacologia , Animais , Bioensaio , Nanismo/genética , Nanismo/patologia , Feminino , Heterozigoto , Masculino , Camundongos , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/patologia , Tiroxina/sangueRESUMO
Involution of thyroid hyperplasia was induced in mice by discontinuing a goitrogenic treatment (low iodine diet plus 0.25% propylthiouracil for 10 days) and returning either to a moderate iodine diet (MID; 1 microgram I/day) alone or associated with T3 administration (1 microgram/day) or to a high iodine diet (HID; 10 micrograms I/day) alone or associated with T3 treatment. Thyroid involution was studied by morphological, stereological, and biochemical methods after 2, 4, 6, and 8 days of involution. Age-paired, HID-fed animals were used as controls. When the involution was induced by MID, the glands resumed a normal morphological aspect. The synthesis and secretion of T3 were highly stimulated on day 2, but decreased thereafter. Plasma T4 levels reached a plateau at 50% of the control value from days 2-8. The administration of T3 together with MID accelerated the involution of hyperplasia and colloid accumulation in the follicular lumina. The synthesis and secretion of T3 and T4 remained lower than those in controls. When the involution was induced by HID, the thyroid weight remained higher than that in controls or in any involuting groups. The number of follicles and epithelial cells as well as the glandular thyroglobulin content were twice the control values. A Wolff-Chaikoff effect was evident on day 4, and hypothyroidism persisted. When HID was supplemented with T3 treatment, glandular weight and morphology were normal, but the Wolff-Chaikoff effect occurred earlier. In conclusion, the iodine dose given after a goitrogenic treatment must be carefully controlled; a high but physiological dose can have deleterious effects, whereas a small dose is beneficial. T3 prevents the deleterious effects of HID, but the thyroid enters a resting state.
Assuntos
Iodo/farmacologia , Glândula Tireoide/patologia , Tri-Iodotironina/farmacologia , Animais , Dieta , Feminino , Hiperplasia/induzido quimicamente , Camundongos , Camundongos Endogâmicos C3H , Glândula Tireoide/efeitos dos fármacos , Tiroxina/sangueRESUMO
The effects of iodide and thyroxine (T4) on female mice fed a low iodine diet (LID) for 8 weeks were analysed by morphological, stereological and biochemical methods. Iodide was given at a dose of 10 micrograms/day (HID) or 1 microgram/day (MID), either alone or together with daily injections of 1 microgram T4 for 8 or 40 days. With HID, the thyroid weight and the numbers of follicles and cells remained higher than in controls, although cell necrosis occurred. Colloid volume increased and iodine was stored within the gland: a colloid goitre with non-functioning follicles was produced. With MID, the glands resumed an almost normal appearance. With T4 and LID, progressive normalization occurred, but after 40 days thyroid weight and numbers of follicles and cells remained higher than in controls. Glandular iodine content slowly increased and reached control value. The proportions of 125I-labelled tri-iodothyronine (T3) and T4 in thyroglobulin were reduced. With T4 and HID, the glands resumed a normal appearance. Neither necrosis nor folliculoneogenesis was noted. The proportions of 125I-labelled T3 and T4 in thyroglobulin were reduced, but T3 and T4 serum levels were higher than with HID. With T4 and MID, a normal state was obtained as early as day 8. After 40 days the gland was morphologically and functionally inactive. In conclusion, the association of T4 and iodide seems to be the best way to obtain a rapid and complete involution of thyroid hyperplasia. The administration of T4 prevents the deleterious effects of an excess of iodine on follicular cells, and causes the gland to enter a slow-functioning state.
Assuntos
Iodetos/farmacologia , Iodo/deficiência , Glândula Tireoide/efeitos dos fármacos , Tiroxina/farmacologia , Animais , Dieta , Feminino , Bócio/patologia , Bócio/fisiopatologia , Iodo/administração & dosagem , Camundongos , Camundongos Endogâmicos ICR , Glândula Tireoide/patologia , Glândula Tireoide/fisiopatologiaRESUMO
Nuclear pore complexes were analyzed in freeze-fractured replicas of thyroid follicular cells of C3H mice in different physiological states. Thyroid stimulation induced a rapid and simultaneous increase of the nuclear surface and volume and of the total number of pore complexes. The numerical density (Na) of pore complexes increased at the 6th day of stimulation, but after that time the proportion of cells with an increased Na was always higher than the proportion of 3H-labelled nuclei. During thyroid involution, all the nuclear parameters, including the Na, returned to normal values. These results indicate that the total number of pore complexes and their Na are correlated with the cellular activity rather than with the cell cycle. They also suggest that 2 different mechanisms are involved in the generation of pore complexes: first, an addition of new membranes with a low density of pore complexes; later, a formation of new pore complexes in preexisting membranes. However, during involution, parts of the nuclear membranes and pore complexes in the remaining parts disappear synchronously. In freeze-fractured thyroid nuclear membranes, 2 neighbouring pore complexes were always separated by a distance of 105 nm. Clusters of pore complexes were not observed. A comparison of the distances between pore complexes and between randomly generated points never showed any significant differences indicating that pore complexes were randomly distributed.
Assuntos
Membrana Nuclear/ultraestrutura , Glândula Tireoide/ultraestrutura , Animais , Feminino , Hiperplasia , Iodo/farmacologia , Camundongos , Camundongos Endogâmicos C3H , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/fisiologiaRESUMO
At one month, the thymus weight of NMRI mice heterozygous for the Nu gene was lower than that of the wild type. However, the thymic structure was normal and no significant anomalies at the ultrastructurallevel could be found either in epithelial cells or in thymocytes. Stereologic data showed that the loss of weight was only due to a decrease of the lymphoid population, whereas the absolute number of epithelial cells was unmodified. Several hypotheses that could explain the reduced number of thymocytes were discussed.
Assuntos
Camundongos Nus/genética , Timo/anatomia & histologia , Animais , Feminino , Heterozigoto , Masculino , Camundongos , Camundongos Nus/anatomia & histologia , Tamanho do Órgão , Timo/ultraestruturaRESUMO
A case of a crown dilaceration in an upper permanent incisor of a 6-year-old child is described. Microradiographs of sagittal sections demonstrated that enamel was broken into fragments which differed on the vestibular and palatal sides. A study of the structural lines in the dentin layer and the disposition of the enamel fragments permits consideration of the lesion as a consolidated fracture.
Assuntos
Incisivo/anormalidades , Odontogênese , Criança , Esmalte Dentário/anormalidades , Cavidade Pulpar/anormalidades , Cavidade Pulpar/diagnóstico por imagem , Dentina/anormalidades , Humanos , Incisivo/diagnóstico por imagem , Incisivo/cirurgia , Masculino , Microrradiografia , Extração DentáriaRESUMO
The formation of ciliary necklaces during ciliogenesis in a thymic cyst was observed in freeze-etched replicas. The necklaces first appear as clusters of particles arranged in concentric circles on a flat area of the cell membrane. As soon as the cilium begins to grow, the particles move to the periphery.
Assuntos
Cílios/ultraestrutura , Timo/ultraestrutura , Animais , Técnica de Fratura por Congelamento , CamundongosRESUMO
Goitrogenesis induced in mice by iodine deficiency took place in two distinct phases. The first phase lasted four weeks and was characterized histologically by the classic signs of hyperplasia: colloid resorption, increase in the height of the epithelium and enlargment of the capillaries. After the fourth week, the morphological changes in the thyroid were different in males and females. In the male, pluristratified follicles, secondary follicular cavities and papillary projections were observed. In the female, most of the follicles retained their hyperplastic appearance, while papillary projections were observed in very few follicles.
Assuntos
Iodo/deficiência , Glândula Tireoide/patologia , Animais , Feminino , Hiperplasia , Masculino , Camundongos , Microscopia Eletrônica , Fatores Sexuais , Glândula Tireoide/ultraestruturaRESUMO
The histogenesis of the mouse thymus was studied by means of light and electron microscopy in an attempt to clarify the simultaneous development of stromal and lymphoid cell populations. On the twelfth day of embryonic life, the thymus primordium was composed principally of undifferentiated epithelial cells and some lymphoblasts. In the developing cortical regions, lymphoblasts accumulated rapidly, stretching the epithelial cells which became stellate in shape. The latter contained multivesicular bodies and, from the sixteenth day on, also typical clear vacuoles. Medullary regions were prefigurated as soon as day 13 by several areas wherein lymphoblasts were sparse and epithelial cells were closely associated, with numerous desmosomes and abundant tonofilaments. On the sixteenth day, some epithelial cells in these regions were differentiated into globular cells, or formed Hassall's corpuscles and intra- or extracellular cysts. On the seventeenth day, the presence of interdigitating cells in the medullary areas completed cortico-medullary differentiation. On the eighteenth day, small cortical thymocytes differentiated and the thymus possessed all characteristics of an adult thymus. Thus, at birth, the histogenesis of the mouse thymus was achieved and the only further modification consisted in a gain of weight.
Assuntos
Camundongos Endogâmicos C3H/embriologia , Timo/embriologia , Fatores Etários , Animais , Animais Recém-Nascidos , Autorradiografia , Células Epiteliais , Feminino , Masculino , Camundongos , Núcleos Septais/citologia , Linfócitos T/citologia , Timo/citologia , Timo/fisiologiaRESUMO
Thymic nurse cells (TNC), which are multicellular complexes composed of epithelial cells and thymocytes, were obtained from C3H-mice thymuses. They were described by means of light and electron microscopy. The morphology of epithelial cells forming isolated TNC compared to that of small tissue fragments obtained by enzymatic digestion revealed that TNC could be derived from all parts of the thymus: cortex, corticomedullary junction and medulla, the cortex being their principal source. This variety of origin, the presence of several epithelial cells inside a single TNC, the presence of non-lymphoid cells, and the various locations of cleaved desmosomes confirmed that their aspect "in vitro" as round and sealed structures can be considered to be an artifact due to the isolation technique used. Indeed, during this procedure, they are formed by a process of wrapping of the epithelial cytoplasm around the tightly associated thymocytes. All three epithelial cell types: cortical reticular cells, medullary reticular cells, and medullary globular cells can form TNC.
Assuntos
Timo/citologia , Animais , Comunicação Celular/fisiologia , Separação Celular/métodos , Células Epiteliais , Epitélio/fisiologia , Epitélio/ultraestrutura , Feminino , Camundongos , Microscopia Eletrônica , Timo/fisiologia , Timo/ultraestruturaRESUMO
Murine thymic macrophages and interdigitating cells, also called thymic accessory cells, were characterized by means of light- and electron microscopy. The cells were studied in suspension, during isolation by enzymatic digestion and in vivo. They were observed as isolated cells or as components of multicellular complexes, some of which were rosettes and were composed of lymphoid cells centered on each type of accessory cell. We also noted other cell complexes including macrophages that resembled classical epithelial nurse cells. We consider that multicellular complexes represent lymphostromal associations already existing in vivo, because we observed them at the periphery of thymic pieces undergoing enzymatic treatment. The heterogeneity of macrophages that we observed in vitro was also noted in vivo. In vivo macrophages were of three types: classical phagocytic cells distributed throughout the gland, cortical elongated cells in close contact with lymphoid blast cells, and atypical nurse cells containing mitotic cells and located in the inner cortex. The morphological aspects of the latter two cell types suggest that cortical macrophages in vivo have other roles: they can be interpreted as images of positive or negative cell selection. We also believe that rosettes are formed by elongated cortical macrophages when they are enzymatically isolated from the thymus.