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1.
Clin Endocrinol (Oxf) ; 79(6): 760-9, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23941570

RESUMEN

Headache is very common in pituitary disease and is reported to be present in more than a third of all patients with pituitary adenomas. Tumour size, cavernous sinus invasion, traction or displacement of intracranial pain-sensitive structures such as blood vessels, cranial nerves and dura mater, and hormonal hypersecretion are implicated causes. The present review attempts to systematically review the literature for any combination of headache and pituitary or hormone overproduction or deficiency. Most data available are retrospective and/or not based on the International Headache Society (IHS) classification. Whereas in pituitary apoplexy a mechanical component explains the almost universal association of the condition with headaches, this correlation is less clear in other forms of pituitary disease and a positive impact of surgery on headaches is not guaranteed. Similarly, invasion into the cavernous sinus or local inflammatory changes have been linked to headaches without convincing evidence. Some studies suggest that oversecretion of GH and prolactin may be important for the development of headaches, and treatment, particularly with somatostatin analogues, has been shown to improve symptoms in these patients. Otherwise, treatment rests on general treatment options for headaches based on an accurate clinical history and a precise classification which includes assessment of the patient's psychosocial risk factors.


Asunto(s)
Cefalea/etiología , Enfermedades de la Hipófisis/complicaciones , Adenoma/complicaciones , Adenoma/fisiopatología , Adenoma/cirugía , Fenómenos Biomecánicos , Agonistas de Dopamina/uso terapéutico , Cefalea/tratamiento farmacológico , Cefalea/fisiopatología , Hormona de Crecimiento Humana/metabolismo , Humanos , Apoplejia Hipofisaria/complicaciones , Apoplejia Hipofisaria/fisiopatología , Enfermedades de la Hipófisis/fisiopatología , Enfermedades de la Hipófisis/terapia , Neoplasias Hipofisarias/complicaciones , Neoplasias Hipofisarias/fisiopatología , Neoplasias Hipofisarias/cirugía , Prolactina/metabolismo , Somatostatina/análogos & derivados , Somatostatina/uso terapéutico
2.
Ultramicroscopy ; 111(8): 1043-54, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21740867

RESUMEN

A new simultaneous autofocus and twofold astigmatism correction method is proposed for High Angle Annular Dark Field Scanning Transmission Electron Microscopy (HAADF-STEM). The method makes use of a modification of image variance, which has already been used before as an image quality measure for different types of microscopy, but its use is often justified on heuristic grounds. In this paper we show numerically that the variance reaches its maximum at Scherzer defocus and zero astigmatism. In order to find this maximum a simultaneous optimization of three parameters (focus, x- and y-stigmators) is necessary. This is implemented and tested on a FEI Tecnai F20. It successfully finds the optimal defocus and astigmatism with time and accuracy, compared to a human operator.

3.
J Microsc ; 240(1): 38-49, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21050212

RESUMEN

Fast and reliable autofocus techniques are an important topic for automated scanning electron microscopy. In this paper, different autofocus techniques are discussed and applied to a variety of experimental through-focus series of scanning electron microscopy images with different geometries. The procedure of quality evaluation is described, and for a variety of scanning electron microscope samples it is demonstrated that techniques based on image derivatives and Fourier transforms are in general better than statistical, intensity and histogram-based techniques. Further, it is shown that varying of an extra parameter can dramatically increase quality of an autofocus technique.

4.
J Clin Endocrinol Metab ; 93(5): 1758-66, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18319317

RESUMEN

CONTEXT: Pancreas grafts can be drained through the iliac vein (systemic drainage) or the portal vein. OBJECTIVE: We hypothesized that normalization of portal insulin in patients with portal pancreas graft drainage stimulates the GH/IGF-I axis and thereby contributes to glucose control. METHODS: We compared patients after combined kidney and pancreas transplantation with portal drainage (n = 7) to patients with systemic drainage of the pancreas graft (n = 8) and nondiabetic controls (n = 8). Overnight fasting sera were analyzed for free and total IGF-I and IGF-binding proteins. Glucose regulatory hormones were examined after an oral glucose tolerance test and GH after stimulation with GHRH. RESULTS: Systemic drainage led to higher basal and stimulated insulin levels than portal drainage (P < 0.05), but increments in response to oral glucose were reduced in both transplanted groups (P < 0.05 vs. controls). However, glucose tolerance was similar in all groups. Circulating free and total IGF-I and IGF-binding protein-3 were similar to control levels in the systemic drainage group but elevated in the portal drainage group (P < 0.05). Consistently, the GH response was reduced in the portal drainage group (P < 0.05 vs. controls) and correlated inversely with free IGF-I (r = -0.63, P < 0.05). CONCLUSION: Portal drainage of pancreatic endocrine secretion in pancreas graft recipients raises IGF-I and lowers GH secretion. These changes might explain that glucose regulation is maintained despite lower peripheral insulin levels, compared with patients with systemic graft drainage and nondiabetic control subjects.


Asunto(s)
Diabetes Mellitus Tipo 1/cirugía , Hormona de Crecimiento Humana/fisiología , Factor I del Crecimiento Similar a la Insulina/fisiología , Trasplante de Páncreas , Adulto , Péptido C/análisis , Diabetes Mellitus Tipo 1/fisiopatología , Drenaje , Femenino , Glucagón/sangre , Prueba de Tolerancia a la Glucosa , Hormona de Crecimiento Humana/metabolismo , Humanos , Insulina/sangre , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Masculino , Persona de Mediana Edad , Vena Porta/fisiología
5.
Eur J Cell Biol ; 80(9): 580-5, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11675933

RESUMEN

The E-cadherin/catenin complex is a powerful invasion suppressor in epithelial cells. It is expressed in the human MCF-7 breast cancer cell line family, but functionally defective in the invasive MCF-7/6 variant. Previous experiments have shown that IGF-I, tamoxifen, retinoic acid and tangeretin are able to upregulate the function of this complex in MCF-7/6 cells. We investigated the effect of 8-prenylnaringenin (8-PN), the phytoestrogen present in hops and beer, on aggregation, growth and invasion in MCF-7/6 cells. 8-PN was found to stimulate E-cadherin-dependent aggregation and growth of MCF-7/6 cells in suspension. These effects could be inhibited by the pure anti-estrogen ICI 182,780. 8-PN did not affect invasion of MCF-7/6 cells in the chick heart assay in vitro. In all these aspects 8-PN mimics the effects of 17beta-estradiol on MCF-7/6 cells.


Asunto(s)
Cerveza , Cadherinas/metabolismo , Adhesión Celular/efectos de los fármacos , Agregación Celular/efectos de los fármacos , Estrógenos no Esteroides/farmacología , Flavanonas , Flavonoides/farmacología , Humulus/química , Isoflavonas , Neoplasias de la Mama , Femenino , Humanos , Fitoestrógenos , Preparaciones de Plantas , Células Tumorales Cultivadas , Ensayo de Tumor de Célula Madre , Regulación hacia Arriba
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