Objective. The plasmid‐encoded adhesin YadA confers pathogenic functions on Yersinia enterocolitica, a microorganism associated with reactive arthritis. While emerging evidence has indicated that the ...persistence of the bacteria in individuals with reactive arthritis is a prerequisite for the development of the disease, the tissue specificity of this immunologic disease sequela remains elusive. The present study was undertaken to investigate YadA‐mediated binding of Y enterocolitica to the most abundant collagens in joints, types I and II collagen.
Methods. Binding studies were performed with recombinant Y enterocolitica strains and highly purified type II collagen and the α1(I) chain of type I collagen, or fragments of these collagens generated by various enzymatic and nonenzymatic cleavage procedures. Interactions of bacteria with the proteins were determined in binding assays with radiolabeled proteins.
Results. Binding regions for YadA were identified at the 181–amino acid fragment α1(I)78CBN of type I collagen and the CB10 fragment of type II collagen. From binding and blocking experiments with α1(I) fragments, cyanogen bromide–derived or mammalian collagenase–derived type II collagen fragments, and synthetic peptides with collagen‐like structures, it was concluded that the binding site for YadA on collagen is determined by a restricted amino acid sequence and is defined within a highly homologous 134–amino acid region. Furthermore, the binding site is not affected by mammalian collagenase digest. Binding of YadA‐positive yersiniae to collagen could be inhibited by an antiserum specific for YadA.
Conclusion. This study provides the first evidence of a binding site for bacterial proteins on collagens which is not determined by the repetitive sequence Gly‐X‐Y of collagens. We speculate that the binding region is conserved between types I and II collagen, the most abundant collagens in the joints. Specific binding of Yersinia products to joint collagens might contribute to the arthritogenic potential of enteropathogenic yersiniae.
During the last years, the validity of classic case control studies in psychiatric genetic research has been increasingly under question due to the risk of population stratification problems inherent ...to this type of association study. By consequence, the application of family-based association studies using parent-offspring trios has been strongly advocated. Recently, however, in a study comparing clinical characteristics between index patients from parent-offspring trios and singleton patients with bipolar affective disorder, the question was raised whether a systematic neglect of case control association studies could lead to a selection bias of susceptibility genes. In a similar approach, we compared demographic and clinical characteristics of 122 singleton bipolar patients with those of 54 bipolar patients derived from parent-offspring trios. The singleton patients did not only present with a higher age of onset, but also with a higher frequency of suicidal behavior and a higher familial loading for suicidality. These findings suggest that the genetic mechanism for disease might be different between trio-based and classic case control samples, where patients are examined whose parents are not available for genetic studies. Thus, giving up case control designs for the sake of family-based association studies could be at the risk of selecting against several genetically determined factors.
Es wird über 2 Patienten mit einer extrakraniellen angiomatösen Gefäßbildung berichtet, die von der A. carotis externa versorgt wird. Sicht- und tastbare Knäuel erweiterter und pulsierender Gefäße in ...der Kopfschwarte oder Halsgegend sowie Gefäßgeräusche sind für die klinische Diagnose wichtig. Die Angiographie objektiviert die Strömungsverhältnisse und sollte zum Ausschluß kombinierter extra- und intrakranieller Gefäßmißbildungen immer durchgeführt werden. Сообщается о 2-х больных с экстракраниальными ангиоматозными пороками развития, которые снабжаются наружной сонной артерией. Видимые и прощупываемые клубки расширенных и пульсирующих сосудов в апоневрозе головы или в области шеи, а также сосудистые шумы важны для клинического диагноза. Ангиография объективирует потоковые соотношения и должна всегда производиться для исключения комбинированных экстра- и интракраниальных сосудистых пороков развития. This article reports two cases of extracranial angiomatous vascular malformation, with blood being conveyed thereto by the external carotid artery. Visible and palpable clusters of dilated and pulsating vessels in the scalp or jugular region as well as vascular murmur are of major importance for clinical diagnosis. Conditions of flow may be objectified with the use of angiography. Therefore, the radiography of vessels should always be used to reliably determine the absence of combined extra- and intracranial vascular malformations.
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