Influence of the aerobic fitness on time spent at high percentage of maximal oxygen uptake during a high-intensity intermittent running

This study aimed to evaluate absolute and relative (%V.O2max) oxygen uptake (total, during effort and pause), and time spent above 90% of V.O2max during high-intensity intermittent running in subjects with different training status. Fourteen males were evaluated and divided (moderate and high aerobic power) according to their V.O2max obtained in an incremental treadmill test to volitional exhaustion. They were then submitted to high-intensity intermittent aerobic exercise (1 min:1 min at maximum velocity attained during the treadmill test, totalling 4 km). A Student's t test for independent data was conducted to identify differences between groups. The moderate aerobic power group spent more time above 90% V.O2max compared to the high aerobic power group (30.2 ±9.1%; 7.3±6%, respectively, P=0.001). Moreover, the moderate aerobic power group presented lower V.O2total (P=0.011), V.O2effort (P=0.007), higher V.O2total (%V.O2), V.O2effort (P<0.001), V.O2pause (V.O2max%) (P=0.006) compared with the high aerobic power group. There was no difference in V.O2pause between groups (P=0.091), the difference between V.O2 effort and pause was greater for the high aerobic power group compared with the moderate group (4.4±2.1; 7.8±2 mL.kg-1.min-1; P=0.009) and the difference between V.O2 effort and pause (%V.O2max) was not different between groups. To conclude, these results demonstrated that individuals with better aerobic fitness spent less time above 90% of the V.O2max and that this response can be due to better capacity to recover during the pause.

Effect of atmospheric mixing layer depth variations on urban air quality and daily mortality during Saharan dust outbreaks

Several epidemiological studies have shown that the outbreaks of Saharan dust over southern European countries can cause negative health effects. The reasons for the increased toxicity of airborne particles during dust storms remain to be understood although the presence of biogenic factors carried by dust particles and the interaction between dust and man-made air pollution have been hypothesized as possible causes. Intriguingly, recent findings have also demonstrated that during Saharan dust outbreaks the local man-made particulates can have stronger effects on health than during days without outbreaks. We show that the thinning of the mixing layer (ML) during Saharan dust outbreaks, systematically described here for the first time, can trigger the observed higher toxicity of ambient local air. The mixing layer height (MLH) progressively reduced with increasing intensity of dust outbreaks thus causing a progressive accumulation of anthropogenic pollutants and favouring the formation of new fine particles or specific relevant species likely from condensation of accumulated gaseous precursors on dust particles surface. Overall, statistically significant associations of MLH with all-cause daily mortality were observed. Moreover, as the MLH reduced, the risk of mortality associated with the same concentration of particulate matter increased due to the observed pollutant accumulation. The association of MLH with daily mortality and the effect of ML thinning on particle toxicity exacerbated when Saharan dust outbreaks occurred suggesting a synergic effect of atmospheric pollutants on health which was amplified during dust outbreaks. Moreover, the results may reflect higher toxicity of primary particles which predominate on low MLH days.

From SARS in 2003 to H1N1 in 2009: lessons learned from Taiwan in preparation for the next pandemic

In anticipation of a future pandemic potentially arising from H5N1, H7N9 avian influenza or Middle East Respiratory Syndrome, and in large part in response to severe acute respiratory syndrome (SARS) in 2003, the city of Taipei, Taiwan, has developed extensive new strategies to manage pandemics. These strategies were tested during the 2009 H1N1 outbreak. This article assesses pandemic preparedness in Taipei in the wake of recent pandemic experiences in order to draw lessons relevant to the broader international public health community. Drawing on Taiwan and Taipei Centers for Disease Control data on pandemic response and control, we evaluated the effectiveness of the changes in pandemic response policies developed by these governments over time, emphasizing hospital and medical interventions with particular attention paid to Traffic Control Bundling. SARS and H1N1 2009 catalysed the Taiwan and Taipei CDCs to continuously improve and adjust their strategies for a future pandemic. These new strategies for pandemic response and control have been largely effective at providing interim pandemic containment and control, while development and implementation of an effective vaccination programme is underway. As Taipei's experiences with these cases illustrate, in mitigating moderate or severe pandemic influenza, a graduated process including Traffic Control Bundles accompanied by hospital and medical interventions, as well as school- and community-focused interventions, provides an effective interim response while awaiting vaccine development. Once a vaccine is developed, to maximize pandemic control effectiveness, it should be allocated with priority given to vulnerable groups, healthcare workers and school children.

Wellness coaching for obesity: a case report

D.S. presented to a medical and surgical weight-loss program to initiate bariatric surgery. He had made numerous attempts at weight loss to no avail and was taking steps toward bariatric surgery as a last viable option. D.S.'s health insurance provider required 3 months of supervised weight loss prior to approval for surgery, and this was initiated with a board-certified bariatrician (MD) and a registered dietitian nutritionist (RDN)/wellness coach.

D.S. presented with a body mass index (BMI) >40 and was classified as morbidly obese with comorbidities of high cholesterol and hyperglycemia and degenerative joint disease (DJD) of the knees. D.S. began the process outlined by his insurance company, meeting with the MD and RDN/wellness coach monthly. A plan was developed by D.S. and his RDN/wellness coach that alligned with his wellness vision, values, and lifestyle. D.S. ate meals and snacks at regular intervals throughout the day, consumed little to no red meat, increased his consumption of fruits and vegetables, and spent 1 hour daily in a swimming pool—walking, swimming, or both.

By the end of the 3-month period required by the insurance provider, D.S. had lost more than 30 lbs, improved his exercise capacity, no longer used a cane, and chose to continue with coaching rather than undergo bariatric surgery. D.S. continued to meet with the MD and RDN monthly for 1 year and averaged a 10-lb weight loss per month for a total of 120 lbs, normalizing his blood panels and improving his joint mobility. D.S. continued to meet with the RDN/wellness coach for a total of 10 visits during year 2 and quarterly visits through year 3. D.S. lost a total of 240 lbs, maintained the weight loss over the 3-year period, and achieved these results solely through lifestyle interventions.

Although bariatric surgery is a viable treatment option for class 2 and 3 obesity, many patients pursue this treatment option without the help of medical and commercial weight loss personnel to improve the likelihood of weight loss sustainability. The investment of lifestyle intervention in this circumstance was less than $5000 (exculsive of blood panels) compared with the $20 000 cost of bariatric surgery at the time of intervention.

Science and regulation. Probiotics: finding the right regulatory balance

Some products marketed as drugs should be excused from Phase I trials, but safety and efficacy claims for dietary supplements should be more tightly regulated.

Impact of transesophageal electrophysiologic study to elucidate the mechanism of arrhythmia on children with supraventricular tachycardia and no preexcitation

An electrophysiologic study (EPS) of children and teenagers with paroxysmal supraventricular tachycardia (SVT) and normal electrocardiography (ECG) in sinus rhythm was evaluated. Generally, EPS is performed only before paroxysmal SVT ablation in these patients. In this study, 140 patients (mean age, 15 ± 3 years) with normal ECG in sinus rhythm were studied for SVT by a transesophageal route in baseline state and after isoproterenol. Idiopathic left or right ventricular tachycardia was diagnosed in four patients (3 %). Anterograde conduction over an atrioventricular (AV) left lateral (n = 10) or septal (n = 9) accessory pathway (AP) was noted in 19 patients (13.5 %) at atrial pacing. Orthodromic AV reentrant tachycardia (AVRT) was induced in these children. Five of the patients had a high rate conducted over AP (>240 bpm in baseline state or >290 bpm after isoproterenol). Two of the patients (a 10-year-old girl with well-tolerated SVT and a 17-year-old with syncope-related SVT) had the criteria for a malignant form with the induction of atrial fibrillation conducted over AP at a rate exceeding 290 bpm in baseline state. Of the 140 patients, 74 (53 %) had typical AV node reentrant tachycardia (AVNRT), nine had atypical AVNRT (6 %), 1 had atrial tachycardia (0.7 %), and 33 (23.5 %) had AVRT related to a concealed AP with only retrograde conduction. Electrophysiologic study is recommended for children with paroxysmal SVT and normal ECG in sinus rhythm. The data are helpful for guiding the treatment. Ventricular tachycardia or atrial tachycardia can be misdiagnosed. Masked preexcitation syndrome with anterograde conduction through AP was present in 13.5 % of the patients, and 1.4 % had a malignant preexcitation syndrome.