Clinicopathologic findings in congenital aneurysms of the great vessels

We describe the clinical, histopathologic, and angiographic findings in four children with congenital abnormalities of the great vessels of unknown cause, comprising either single or multiple arterial aneurysms, aortic/arterial dilatation, vessel tortuosity, or combinations of these abnormalities. Two children had early and severe respiratory distress due to aneurysmal compression of the trachea. All children had diffuse dilatation of several arteries, and two children also had tortuosity of multiple arteries. Progression of these abnormalities was clearly evident in one child, in whom diffuse vessel irregularity and tortuosity affected intra-abdominal, and intra and extra-cranial arteries. One child died at 5 years, while the other three have undergone successful surgical repair in the first 3 months of life and are now well, between age 2.5 and 7 years. The phenotype of each child appears unique but all have in common the rare finding of aneurysms of the aorta and main pulmonary artery. Congenital aortic aneurysms did not occur as an isolated finding in any of these children. © 1996 Wiley-Liss, Inc.     

Morphological skin ageing criteria by multiphoton laser scanning tomography: non-invasive in vivo scoring of the dermal fibre network

Background: Morphological changes in the dermal collagen and elastin fibre network are characteristic for skin ageing and for pathological skin conditions of the dermis. Objectives: To characterize pathological and physiological conditions by multiphoton laser scanning tomography (MLT) in vivo, it is necessary to investigate and identify morphological alterations related to ageing. Methods: In vivo MLT was used to image two‐photon excited autofluorescence (AF) and second harmonics generation (SHG) in human dermis of 18 volunteers of different ages. Criteria for the evaluation of age‐dependent morphological changes in MLT images were fibre tension and morphology, network pattern, clot formation and image homogeneity. These criteria were weighted and a score was calculated. Results: The resulting MLT‐based Dermis Morphology Score is correlated with age (R² = ?0.90) and with the previously published SHG to AF Ageing Index of Dermis (R² = 0.66). The two groups of young (age 21–38) and old (age 66–84) volunteers showed a significant difference in MLT score values (P < 0.001). Conclusions: We could demonstrate an in vivo relationship between morphological characteristics of human dermis assessed by MLT and age. The present score allows the semi‐quantitative evaluation of specific morphological changes of the dermal fibre network in ageing skin by in vivo AF and SHG imaging. This method will be useful for diagnostics of pathological conditions and their differentiation from ageing effects.     

Variants of the elastin (ELN) gene and susceptibility to intracranial aneurysm: a synthesis of genetic association studies using a genetic model-free approach

Background: The presence of an intracranial aneurysm (IA) is thought to have a genetic origin. The genetic association studies (GAS) that investigated the association between IA and elastin gene (ELN) variants have produced contradictory or inconclusive results. Materials and methods: In order to decrease the uncertainty of estimated genetic risk effects, a meta-analysis of published GAS-related variants in the ELN gene (ELN INT20 1315T > C, EX20 1264G > A, INT23 1501 + 24T > C and INT4 196 + 71G > A) with susceptibility to IA was conducted using a genetic model-free approach. The risk effects were estimated using the generalized odds ratio (ORG) metric. Results: The analysis showed significant association for the INT20 1315T > C variant [ORG = 0.66 (0.45–0.95)], indicating a protection effect. For the variants EX20 1264G > A, INT23 1501 + 24T > C and INT4 196 + 71G > A, no statistically significant association with IAs was found. Conclusion: There is evidence that the ELN variant INT20 1315T > C is implicated in the development of IA; however, the results should be interpreted with caution since the number of published studies is limited.     

Mechanical forces alter extracellular matrix synthesis by human periodontal ligament fibroblasts

Periodontal ligament fibroblasts (PDLFs) are a heterogeneous population of cells that are involved in the normal maintenance, repair and regeneration of both the ligament and adjacent hard tissues. Additionally, the ability of these cells to respond to mechanical stimulation suggests that they have a central role in mediating the osseous remodeling that underlies physiological and orthodontic tooth movement. To characterize their role further in this process, the current study evaluated the effect of tensional stress on the biosynthesis of extracellular matrix (ECM) proteins by human PDLFs. Cell strains were established from extracted human premolars and third molars. Cells exposed to 5% biaxial deformation (strain) at a frequency of 30 times/min for 24 hr exhibited statistically significant increases in type I collagen and fibronectin synthesis, and a statistically signficant decrease in tropoelastin production relative to unstretched controls. Cells exposed to 10% strain exhibited similar responses for fibronectin and tropoelastin while the amount of type I collagen synthesized by stretched cells did not differ from control levels. These results indicate that mechanical stimulation of PDLFs alters type I collagen, tropoelastin and fibronectin production and that these cells are differentially responsive to varying levels of mechanical stress. The ability of these cells to alter ECM protein synthesis in response to specific magnitudes of tensional stress may in part explain how PDLFs regulate ligament and hard tissue remodeling.