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排序方式: 共有307条查询结果,搜索用时 234 毫秒
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Helicobacter pylori in Barrett's esophagus. 总被引:2,自引:0,他引:2
J C Ferreres F Fernández A Rodríguez Vives I González-Rodilla I Ursúa R Ramos J F Val-Bernal 《Histology and histopathology》1991,6(3):403-408
Barrett's esophagus is an anatomicoclinical state in which, due to the prolonged action of gastroesophageal reflux, the squamous epithelium is replaced by columnar epithelium. Helicobacter pylori has been implicated in the pathogenesis of various gastrointestinal disorders and has occasionally been observed in Barrett's esophagus. The aim of this study is to determine the incidence of H. pylori in Barrett's esophagus and try to establish its role in the pathogenesis of this disorder. H. pylori was observed in 31 biopsies (44.3%) of the 70 studied, mainly when the epithelium is of the gastric atrophic-fundic type (p less than 0.01). Its presence shows no relation to the degree of inflammatory activity and does not seem, therefore, to play an important role in the pathogenesis of the lesion. 相似文献
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We have studied the structure of solid films obtained by x-ray diffraction, from several basic polypeptides with a defined sequence. The alterating polypeptides poly(Ala-Lys), poly(Leu-Lys), poly(Val-Lys), and poly(Arg-Leu) all show a cross-β-structure in which layers of hydrophilic side chains alternate with layers containing hydrophobic side chains. The other polypeptides studied are not in the β-conformation and appear to be in the α-helical conformation. The helices obtained from poly(Lys-Ala-Ala) and poly(Lys-Ala-Ala-Lys) appear to be packed in an unusual fashion, which favors interaction between alanine side chains. Such behavior is not found in poly(Lys-Leu-Ala). 相似文献
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Itziar Alkorta Carlos Garbisu María J. Llama Juan L. Serra 《Biotechnology Techniques》1995,9(2):95-100
Summary The extracellular pectin lyase (PNL, E.C. 4.2.2.10) from Penicillium italicum was utilized in batch and confined in a continuous-flow ultrafiltration membrane reactor. The enzyme catalyzed the decrease in viscosity of pectin solutions at pH 6.0 as well as of different fruit juices at their respective pH. PNL decreased the viscosity of pectin solutions in the membrane (60% after 30 min) more than in the batch (46% after 70 min) reactors, but similar viscosity reduction of fruit juices was achieved in both reactors. The enzyme decreased the viscosity of grape, peach and melon juices to different extents, but failed to do so with apple or pear juices. It can be concluded that the utilization of PNL in a membrane reactor appears of interest for the clarification of fruit juices. 相似文献
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Kazuhiro Tajima-Pozo Ana Montes-Montero Itziar Güemes Sara González-Vives Marina Díaz-Marsá José Luis Carrasco 《Endocrinología y nutrición》2013,60(7):396-403
Activity of the hypothalamic-pituitary-adrenal axis had been studied for the past half century, when some researchers noted that some patients with Cushing's syndrome and severe mood disorders had high baseline cortisol levels, which resulted in an inhibited response in the 1 mg dexamethasone suppression test. Altered dexamethasone suppression test results were subsequently found in many psychiatric diseases, including anorexia nervosa, obsessive-compulsive disorder, degenerative dementia, bipolar disorders, and schizophrenia. The relationship between high baseline cortisol levels and stress has also been studied. Some researches on the genesis of borderline personality disorder focused on traumatic childhood backgrounds. Other investigations aimed at elucidating the relationship between traumatic backgrounds and some psychiatric disorders noted that patients with post-traumatic stress disorder and borderline personality disorder showed an enhanced cortisol suppression with low cortisol doses (0.5 mg). Recent studies showed that use of an ultra-low dose of cortisol during the dexamethasone suppression test may be helpful for deteting disorders with hyperactivity of the hypothalamic-pituitary-adrenal axis.Recent advances in neuroimaging support the existence of hyperactivity of the hypothalamic-pituitary-adrenal axis in patients with borderline personality disorder, relating a decreased pituitary gland volume to major traumatic backgrounds and suicidal attempts. The purpose of this paper is to make a narrative review of research using dexamethasone suppression test in psychiatric disorders, in order to ascertain its value as a supplemental diagnostic test or as a prognostic marker. 相似文献
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Vivas Daniel Grau-Vorster Marta Oliver-Vila Irene García-López Joan Vives Joaquim 《Molecular biology reports》2020,47(7):5145-5154
Molecular Biology Reports - Proper bony tissue regeneration requires mechanical stabilization, an osteogenic biological activity and appropriate scaffolds. The latter two elements can be combined... 相似文献
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Maria Leticia Zarantonelli Anna Skoczynska Aude Antignac Meriem El Ghachi Ala-Eddine Deghmane Marek Szatanik Céline Mulet Catherine Werts Lucie Peduto Martine Fanton d’Andon Françoise Thouron Faridabano Nato Lionel LeBourhis Dana J. Philpott Stephen E. Girardin Francina Langa Vives Philippe Sansonetti Gérard Eberl Ivo G. Boneca 《Cell host & microbe》2013,13(6):735-745