Exercise-induced asthma in a group of South African schoolchildren during physical education classes

Objectives. The study was conducted to ascertain whether physical education teachers, using a peak flow meter, could reliably screen for exercise-induced asthma (EIA) in children during free running.Design, setting and subjects. The study was conducted using a convenience sample of male pupils between the ages of 12 and 18 years. They were tested with a peak flow meter for peak expiratory flow rate (PEFR) and with a flow-volume curve for forced expiratory flow in 1 second (FEV1) before and 10 minutes after a self-paced free running test during physical education classes. Testing was undertaken by teachers using the peak flow meter and by a medical doctor using a flow-volume curve.Results. Using a 10% decrease in flow parameters (PEFR and FEV1), teachers detected EIA in 14.9% of pupils and the doctor detected EIA in 21.7% of pupils.Conclusion. We conclude that EIA is common and that teachers using a peak flow meter can detect EIA and thus screen for it; they do, however, underestimate the true magnitude of the problem

Ambulatory blood pressure monitoring - comparison with office blood pressure in patients on antihypertensive therapy in private practice

Introduction. Available data on the use of 24-hour ambulatory blood pressure recordings in private practice are limited. For this purpose we studied 39 consecutive hypertensive patients on treatment in a private practice.Method. Office blood pressure, 24-hour ambulatory blood pressure, daytime ambulatory blood pressure and M-mode echocardiography were undertaken in 39 consecutive hypertensive patients (21 men, 18 women) on treatment.Results. Mean 24-hour ambulatory blood pressure and mean daytime ambulatory blood pressure were lower than office blood pressure, similar to findings seen in academic settings. A blood pressure load of more than 50% was seen in 12 out of 39 patients (31 %). Left ventricular hypertrophy, assessed by means of Framingham criteria, was seen in 33% of patients. A white-coat effect was seen in 15.4% of patients.Conclusions. A large proportion (33%) of patients on treatment for hypertension had left ventricular hypertrophy, despite normal electrocardiograms. Ambulatory blood pressure measurements identified a blood pressure load of more than 50% in 31 % of patients on treatment for hypertension

Regulation of calcium homeostasis in activated human neutrophils - potential targets for anti-inflammatory therapeutic strategies

Objectives. The objectives of the current study were to: (i) present an integrated model for the restoration of calcium homeostasis in activated human neutrophils based on current knowledge and recent research; and (ii) identify potential targets for the modulation of calcium fluxes in activated neutrophils based on this model and to investigate the effects of intracellular probes which target key processes involved in calcium homeostasis and pro-inflammatory activity in these cells. Design and setting. Laboratory-based experimental research using purified human neutrophils from healthy, adult human volunteers. Outcome measures. Calcium metabolism and pro-inflammatory activity of neutrophils. Results. Modulation of calcium fluxes in activated human neutrophils can be achieved by cAMP-dependent upregulation of the activity of the endomembrane Ca2+-ATPase which resequesters cytosolic Ca2+. Formoterol, a long-acting b2-agonist, elevates intracellular cAMP levels, accelerates Ca2+ restoration in activated neutrophils and downregulates the pro-inflammatory responses of these cells. Alterations in the membrane potential of activated neutrophils may play a role in regulating calcium reuptake into the cells as attenuation of the membrane depolarisation response is associated with accelerated calcium influx. Conclusions. Modulation of the activity of the endomembrane Ca2+-ATPase in human neutrophils represents an important target for anti-inflammatory therapeutic strategies, while new insights into the role played by membrane depolarisation in regulating calcium fluxes in these cells may also facilitate development of novel anti-inflammatory agents directed against neutrophils. (South African Medical Journal: 2002 92(12): 990-996

Structural Causes of Right Bundle Branch Block—Time for a Closer Look?

Right bundle branch block is an electrocardiographic phenomenon with specific criteria

The accessory papillary muscle with inferior J-waves - peculiarity or hidden danger?

Originally described in 1953, today the so-called J-wave is the source of much controversy. As a marker of so-called "early repolarization", this variant has been regarded as a totally benign variant since the 1960's. However, since then a wealth of data have indicated that the J-wave may be a marker of a highly arrhythmogenic substrate with a resultant high risk of sudden cardiac death

High-k Dielectric Thickness and Halo Implant on Threshold Voltage Control

High-k dielectric oxides have been used to replace the widely used silicon dioxide (SiO2) gate dielectrics to overcome physical limits of transistor scaling. The thickness of high-k gate dielectric influences the threshold voltage (VTH) and off-state leakage current (IOFF). A device with high drive current (ION) and low IOFF gives a high on-off current ratio (ION/IOFF), which leads to a faster switching speed for the Ntype Metal Oxide Semiconductor Field Effect Transistor (NMOS). In order to achieve the best ION/IOFF ratio for a predetermined range of VTH, halo implant was used to adjust the threshold voltage. The finding shows that optimum VTH and ION/IOFF ratio can be achieved by selecting the most suitable halo implant dose in a virtually fabricated 14nm gate-length La2O3-based NMOS device with varying high-k dielectric oxide thickness