The diagnostic accuracy of acetabular labral tears using magnetic resonance imaging and magnetic resonance arthrography: a meta-analysis

Objectives  

Magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA) have been advocated for the diagnosis of acetabular labral tears. The purpose of this study was to determine the sensitivity and specificity of MRI and MRA in diagnosing acetabular labral tears using meta-analysis.     

Effect of vitamin A supplementation on measles-specific antibody levels in Guinea-Bissau

We have previously reported that vitamin A supplementation with measles vaccine at age 9 months increases measles-specific antibody concentrations in children at age 18 months compared with placebo. We examined these children when they reached age 6-8 years. Fewer vitamin A-supplemented children had non-protective antibody concentrations (p=0.0095); among children with protective antibody levels, vitamin A-supplemented children tended to have higher geometric mean antibody titres (p=0.09). Thus, simultaneous administration of vitamin A and measles vaccine at age 9 months had a long-term effect on measles-specific antibody levels and may contribute to improved measles control in less-developed countries.     

Schwannomas and Their Pathogenesis

Schwannomas may occur spontaneously, or in the context of a familial tumor syndrome such as neurofibromatosis type 2 (NF2), schwannomatosis and Carney's complex. Schwannomas have a variety of morphological appearances, but they behave as World Health Organization (WHO) grade I tumors, and only very rarely undergo malignant transformation. Central to the pathogenesis of these tumors is loss of function of merlin, either by direct genetic change involving the NF2 gene on chromosome 22 or secondarily to merlin inactivation. The genetic pathways and morphological features of schwannomas associated with different genetic syndromes will be discussed. Merlin has multiple functions, including within the nucleus and at the cell membrane, and this review summarizes our current understanding of the mechanisms by which merlin loss is involved in schwannoma pathogenesis, highlighting potential areas for therapeutic intervention.     

Safety of same day discharge radial PCI in patients under and over 75 years of age

To check the safety of same day discharge radial PCI in patients under or over 75 years of age. A total of 943 patients who had same day discharge radial PCI between April 1998 and March 2001 were contacted. Patient health status, entry site complications, and repeat interventions during the first month after the procedure were compared in patients under 75 years of age (< 75) with those 75 or over (> or = 75). Responses were received from 811 patients (694 aged < 75 and 117 aged > or = 75 years). Two hundred and thirty-eight patients (34.3%) aged < 75 years and 36 patients (30.7%) aged > or = 75years reported one or more access site complications during the first 24 hours postdischarge, and 105 (15.1%) and 12 patients (10.3%), respectively, during the first month, (P > 0.05). However, all complications in both groups were minor and none of the patients required admission to the hospital. During the first 24 hours postdischarge only one patient (0.1%) aged < 75 years had a repeat angiogram showing a normal patent vessel, while during the first month 4 patients (0.6%) aged < 75 years and none aged > or = 75 years had target vessel closure. Out of the 132 patients who did not respond to our questionnaire, 1 patient aged < 75 and 1 patient aged > or = 75 years had subacute stent thrombosis within a month and died. There were no major entry site complications, and target vessel closure (0.6% versus 0.7%) was similar in patients aged < 75 and > or = 75 years. Thus, same day discharge radial PCI is safe in patients 75 years old or over.     

Sequence of epicardial repolarisation and configuration of the T wave.

Epicardial activation and repolarisation sequences were investigated in patients with upright or inverted T waves in left ventricular leads of the surface electrocardiogram. Fifteen patients were studied: 10 were undergoing coronary artery bypass grafting (upright T waves) and five aortic valve replacement (four patients with T inversion). Monophasic action potentials were recorded intraoperatively from eight to 10 left ventricular sites in each patient. In patients with upright T waves there was an inverse relation between the duration of the monophasic action potential and the activation time (mean slope -1.44). As a consequence, activation and repolarisation proceeded in opposite directions. Dispersion of repolarisation time (14 ms) was less than dispersion of activation time (23 ms). In patients with T wave inversion caused by aortic stenosis there was no relation between the duration of action potential and activation time; the repolarisation sequence resembled the activation sequence, and the dispersion of repolarisation time was greater than the dispersion of activation time (31 and 26 ms respectively). These results show that there are epicardial repolarisation gradients in man and that these are related to the configuration of the T wave. In patients with upright T waves an inverse relation between the duration of the action potential and the activation time reduces the dispersion of the repolarisation time. When the T wave was inverted this relation was no longer found and the dispersion of repolarisation increased.     

Impact of crystallization firing process on the microstructure and flexural strength of zirconia-reinforced lithium silicate glass-ceramics

Objectives

The aim of this study was to characterize the microstructure of two zirconia-reinforced lithium silicate (ZLS) glass-ceramics and evaluate their mechanical properties before and after the crystallization firing process (CFP).

Fatigue failure load of two resin-bonded zirconia-reinforced lithium silicate glass-ceramics: Effect of ceramic thickness

Objectives

To evaluate the effect of ceramic thickness on the fatigue failure load of two zirconia-reinforced lithium silicate (ZLS) glass-ceramics, adhesively cemented to a dentin analogue material.