How does symmetry impact the flexibility of proteins?

It is well known that (i) the flexibility and rigidity of proteins are central to their function, (ii) a number of oligomers with several copies of individual protein chains assemble with symmetry in the native state and (iii) added symmetry sometimes leads to added flexibility in structures. We observe that the most common symmetry classes of protein oligomers are also the symmetry classes that lead to increased flexibility in certain three-dimensional structures-and investigate the possible significance of this coincidence. This builds on the well-developed theory of generic rigidity of body-bar frameworks, which permits an analysis of the rigidity and flexibility of molecular structures such as proteins via fast combinatorial algorithms.

Molecular karyotyping as a relevant diagnostic tool in children with growth retardation with Silver-Russell features.

Objective: To determine the contribution of submicroscopic chromosomal imbalances to the etiology of Silver-Russell syndrome (SRS) and SRS-like phenotypes.

Study Design: We performed molecular karyotyping in 41 patients with SRS or SRS-like features without known chromosome 7 and 11 defects using the Affymetrix SNP Array 6.0 system (Affymetrix, High Wycombe, United Kingdom).

A promoter polymorphism of the alpha 8 integrin gene and the progression of autosomal-dominant polycystic kidney disease.

Background/aims: Dysregulation of integrins is a feature of tissue remodeling in autosomal-dominant polycystic kidney disease (ADPKD). The alpha 8 beta 1 integrin (alpha8beta1) affects kidney development and the susceptibility to renal injury in mice. We investigated whether the -414 T/C polymorphism in the promoter region of the alpha 8 integrin chain gene (ITGA8) is associated with the progression of renal disease in ADPKD.

Renal and cardiac effects of antihypertensive treatment with ramipril vs metoprolol in autosomal dominant polycystic kidney disease.

Background: Hypertension is a common complication in autosomal dominant polycystic kidney disease (ADPKD). This prospective randomized double-blind study was performed to compare the renal and cardiac effects of the ACE inhibitor ramipril and the beta-blocker metoprolol as first line therapy in ADPKD patients with hypertension.

Methods: Forty-six hypertensive ADPKD patients were randomized to either ramipril (n = 23) or metoprolol (n = 23).

[Urine diagnosis and leukocyturia].

The most common cause of leukocyturia is--in conjunction with bacteriuria--an infection of the urinary tract. In the sediment, leukocytes may be differentiated into neutrophil or eosinophil granulocytes or lymphocytes. When contamination has been excluded, leukocyturia in the absence of significant bacteriuria mandates a further diagnostic evaluation.

Intracranial aneurysms and dolichoectasia in autosomal dominant polycystic kidney disease.

Background: Intracranial saccular aneurysms (ICA) are a known extrarenal manifestation of autosomal dominant polycystic kidney disease (ADPKD). In order to facilitate the definition of subgroups who are at risk for ICA and to determine the prevalence of ICA in these subgroups we studied ADPKD patients with a positive family history for a cerebral event, including cerebral stroke (group I) and intracranial bleeding or known ICA (group II).

Methods: Within an enrolment period of 21 months, 43 ADPKD patients from our outpatient clinic and hospital were examined with cerebral magnetic resonance angiography (MRA).