Anatomical Levels (anatomical + level)

Distribution by Scientific Domains

Selected Abstracts

A mutation in the zebrafish Na,K-ATPase subunit atp1a1a.1 provides genetic evidence that the sodium potassium pump contributes to left-right asymmetry downstream or in parallel to nodal flow

Elin Ellertsdottir
Abstract While there is a good conceptual framework of dorsoventral and anterioposterior axes formation in most vertebrate groups, understanding of left-right axis initiation is fragmentary. Diverse mechanisms have been implied to contribute to the earliest steps of left-right asymmetry, including small molecule signals, gap junctional communication, membrane potential, and directional flow of extracellular liquid generated by monocilia in the node region. Here we demonstrate that a mutation in the zebrafish Na,K-ATPase subunit atp1a1a causes left-right defects including isomerism of internal organs at the anatomical level. The normally left-sided Nodal signal spaw as well as its inhibitor lefty are expressed bilaterally, while pitx2 may appear random or bilateral. Monocilia movement and fluid circulation in Kupffer's vesicle are normal in atp1a1am883 mutant embryos. Therefore, the Na,K-ATPase is required downstream or in parallel to monocilia function during initiation of left-right asymmetry in zebrafish. Developmental Dynamics 235:1794,1808, 2006. 2006 Wiley-Liss, Inc. [source]

Magnetic resonance imaging evaluation of 264 horses with foot pain: The podotrochlear apparatus, deep digital flexor tendon and collateral ligaments of the distal interphalangeal joint

Summary Reasons for performing study: To improve understanding of the interrelationships between injuries of the podotrochlear apparatus and deep digital flexor tendon (DDFT). Hypotheses: There is a difference in frequency of different types of lesions at different anatomical sites of the DDFT. Lesions of the collateral sesamoidean ligament (CSL), distal sesamoidean impar ligament (DSIL), distal interphalangeal (DIP) joint and navicular bursa are seen in association with lesions of the navicular bone. Methods: The magnetic resonance (MR) images of 264 horses with unilateral or bilateral foot pain were analysed and graded. Descriptive statistics were performed to establish the frequency of occurrence of DDFT lesion types at different anatomical levels, and lesions of the CSL, DSIL, navicular bursa, DIP joint and collateral ligaments (CLs) of the DIP joint. A Chi-square test was used to test for a difference in the proportion of navicular bone grades between limbs with and without DDFT lesions at each level, and to compare navicular bone grades for limbs with and without each of DSIL, CSL, navicular bursa or DIP joint lesions. Results: Lesions of the DDFT occurred in 82.6% of limbs, occurring most commonly at the level of the CSL (59.4%) and the navicular bone (59.0%). Core lesions predominated at the level of the proximal phalanx (90.3%), whereas at the level of the CSL and navicular bone core lesions, sagittal splits and dorsal abrasions were most common. There was a positive association between DDFT lesions and navicular bone pathology involving all aspects of the bone. Lesions of the DSIL (38.2% limbs) were more common than those of the CSL (10.5%), but the presence of either was associated with abnormalities of the navicular bone, especially involving the proximal or distal borders and the medulla. Conclusions and clinical relevance: There are close interactions between injuries of the components of the podotrochlear apparatus, the DDFT, the navicular bursa and the DIP joint. Further knowledge about the biomechanical risk factors for injury may have importance for both disease prevention and management. [source]

ORIGINAL ARTICLE: Ultrasonographic evaluation of the femoral vein in anaesthetised infants and young children

ANAESTHESIA, Issue 9 2010
E. H. Suk
Summary We investigated the cross-sectional area of the femoral vein and its relationship to the femoral artery at two anatomical levels, in infants and children. Sixty-six subjects were allocated to one of two groups: infants (< 1 year, n = 31) or children (1,6 years, n = 35). After induction of general anaesthesia, the femoral vein was evaluated by ultrasound with the patients' legs at 30 and 60 of abduction and their hips externally rotated. In each position, measurements were taken at the level of the inguinal crease and 1 cm below the crease. Hip rotation with 60 leg abduction decreased femoral artery overlap at the level of the inguinal crease in both infants (p = 0.013) and children (p = 0.003). Thus, the optimal place for femoral vein cannulation in paediatric patients seems to be at the level of the inguinal crease with 60 leg abduction and external hip rotation. [source]

Anaesthetics and postoperative cognitive dysfunction: a pathological mechanism mimicking Alzheimer's disease

ANAESTHESIA, Issue 4 2010
V. Fodale
Summary With longevity, postoperative cognitive decline in the elderly has emerged as a major health concern for which several factors have been implicated, one of the most recent being the role of anaesthetics. Interactions of anaesthetic agents and different targets have been studied at the molecular, cellular and structural anatomical levels. Recent in vitro nuclear magnetic resonance spectroscopy studies have shown that several anaesthetics act on the oligomerisation of amyloid , peptide. Uncontrolled production, oligomerisation and deposition of amyloid , peptide, with subsequent development of amyloid plaques, are fundamental steps in the generation of Alzheimer's disease. Amyloid , peptide is naturally present in the central nervous system, and is found at higher tissue concentrations in the elderly. We argue that administering certain general anaesthetics to elderly patients may worsen amyloid , peptide oligomerisation and deposition and thus increase the risk of developing postoperative cognitive dysfunction. The aim of this review is to highlight the clinical aspects of postoperative cognitive dysfunction and to find plausible links between possible anaesthetic effects and the molecular pathological mechanism of Alzheimer's disease. It is hoped that our hypothesis will stimulate further enquiry, especially triggering research into elucidating those anaesthetics that may be more suitable when cognitive dysfunction is a particular concern. [source]