Flyways and migratory behaviour of the Vega gull (Larus vegae), a little-known Arctic endemic.

Large gulls are generalist predators that play an important role in Arctic food webs. Describing the migratory patterns and phenology of these predators is essential to understanding how Arctic ecosystems function. However, from all six large Arctic gull taxa, including three long-distance migrants, to date seasonal movements have been studied only in three and with small sample sizes. To document the flyways and migratory behaviour of the Vega gull, a widespread but little-studied Siberian migrant, we monitored 28 individuals with GPS loggers over a mean period of 383 days. Birds used similar routes in spring and autumn, preferring coastal to inland or offshore routes, and travelled 4000-5500 km between their breeding (Siberia) and wintering grounds (mainly the Republic of Korea and Japan). Spring migration mainly occurred in May, and was twice as fast and more synchronized among individuals than autumn migration. Migration bouts mainly occurred during the day and twilight, but rates of travel were always higher during the few night flights. Flight altitudes were nearly always higher during migration bouts than during other bouts, and lower during twilight than during night or day. Altitudes above 2000m were recorded during migrations, when birds made non-stop inland flights over mountain ranges and vast stretches of the boreal forest. Individuals showed high inter-annual consistency in their movements in winter and summer, indicating strong site fidelity to their breeding and wintering sites. Within-individual variation was similar in spring and autumn, but between individual variation was higher in autumn than in spring. Compared to previous studies, our results suggest that the timing of spring migration in large Arctic gulls is likely constrained by snowmelt at breeding grounds, while the duration of migration windows could be related to the proportion of inland versus coastal habitats found along their flyways ('fly-and-forage' strategy). Ongoing environmental changes are hence likely in short term to alter the timing of their migration, and in long term possibly affect the duration if e.g. the resource availability along the route changes in the future.

Tetralogy of Fallot associated with a rare type partially anomalous pulmonary venous connection and levoatrial cardinal vein.

Tetralogy of Fallot is rarely associated with partially anomalous pulmonary venous connection. Unidentified partially anomalous pulmonary venous connection, however, might increase the risk of pulmonary valve replacement in repaired tetralogy of Fallot patients. Here, we present a case of a 19-year-old male who received a correction of tetralogy of Fallot 18 years ago and a rare type of partially anomalous pulmonary venous connection with levoatrial cardinal vein was identified during the follow-up period. The anomalous pulmonary veins were connected to the left hepatic vein and the right superior caval vein. Performing a pulmonary valve replacement, partially anomalous pulmonary venous connection was also corrected with a new approach using the venous plexus between the hepatic veins.

Short-term modulation of the ventilatory response to exercise is preserved in obstructive sleep apnea.

BACKGROUND: The ventilatory response to exercise can be transiently adjusted in response to environmentally (e.g., breathing apparatus) or physiologically altered conditions (e.g., respiratory disease), maintaining constant relative arterial PCO2 regulation from rest to exercise (Mitchell and Babb, 2006); this augmentation is called short-term modulation (STM) of the exercise ventilatory response. Obesity and/or obstructive sleep apnea could affect the exercise ventilatory response and the capacity for STM due to chronically increased mechanical and/or ventilatory loads on the respiratory system, and/or recurrent (chronic) intermittent hypoxia experienced during sleep. We hypothesized that: (1) the exercise ventilatory response is augmented in obese OSA patients compared with obese non-OSA adults, and (2) the capacity for STM with added dead space is diminished in obese OSA patients. METHODS: Nine obese adults with OSA (age: 39±6 yr, BMI: 40±5kg/m2, AHI: 25±24 events/h [range 6-73], mean±SD) and 8 obese adults without OSA (age: 38±10 yr, BMI: 37±6kg/m2, AHI: 1±2) completed three, 20-min bouts of constant-load submaximal cycling exercise (8min rest, 6min at 10 and 30W) with or without added external dead space (200 or 400mL; 20min rest between bouts). Steady-state measurements were made of ventilation (V˙E), oxygen consumption V˙O2), carbon dioxide production (V˙CO2), and end-tidal PCO2 (PETCO2). The exercise ventilatory response was defined as the slope of the V˙E-V˙CO2 relationship (ΔV˙E/ΔV˙CO2). RESULTS: In control (i.e. no added dead space), the exercise ventilatory response was not significantly different between non-OSA and OSA groups (ΔV˙E/ΔV˙CO2 slope: 30.5±4.2 vs 30.5±3.8, p>0.05); PETCO2 regulation from rest to exercise did not differ between groups (p>0.05). In trials with added external dead space, ΔV˙E/ΔV˙CO2 increased with increased dead space (p < 0.05) and the PETCO2 change from rest to exercise remained small (<2mmHg) in both groups, demonstrating STM. There were no significant differences between groups. CONCLUSIONS: Contrary to our hypotheses: (1) the exercise ventilatory response is not increased in obese OSA patients compared with obese non-OSA adults, and (2) the capacity for STM with added dead space is preserved in obese OSA and non-OSA adults.

Antibacterial and antioxidant activities and chemical compositions of volatile oils extracted from Schisandra chinensis Baill. seeds using simultaneous distillation extraction method, and comparison with Soxhlet and microwave-assisted extraction.

The volatile oils were isolated from dried Schisandra chinensis Baill. seeds by Soxhlet extraction (SE), microwave-assisted extraction (MAE), and simultaneous distillation extraction (SDE), and fractions were identified by gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). The essential oils were assessed for their antioxidant and antibacterial activities. GC-MS results also revealed that the major ingredients in the oil extracted by SDE were terpenoids compounds such as ylangene (15.01%), α-phellandrene (8.23%), ß-himachalene (6.95%), and cuparene (6.74), and the oil extracts of MAE and SE mainly contained aromatics such as schizandrins, wuweizisu C, and gomisin A. HPLC analysis results confirmed that more schizandrin was obtained through extraction by MAE (996.64 µg/g) and SE (722.13 µg/g). SDE oil extract showed more significant antioxidant activity than MAE or SE oil. Only volatile oil from SDE showed good antibacterial activity against all tested strains.

A novel expression of exercise induced pulmonary hypertension in human immunodeficiency virus patients: a pilot study.

BACKGROUND: Patients with the human immunodeficiency virus (HIV) are at risk for multiple pulmonary complications including pulmonary hypertension. Exercise induced pulmonary hypertension (EIPH) has been previously described in patients with scleroderma, sickle cell disease and chronic obstructive pulmonary disease, yet has not been associated with the HIV population. METHODS: A prospective case-control study design was implemented. Four HIV patients with unexplained dyspnea and four healthy controls underwent symptom-limited stationary bicycle exercise. Transthoracic Doppler Echocardiography was used to measure tricuspid regurgitation velocity which was used to calculate the right ventricular to right atrial pressure (RV-RA) gradient at rest and at peak exercise using the simplified Bernoulli's equation. Change in RV-RA gradient between rest and peak exercise was calculated and considered to represent change in pulmonary arterial systolic pressure. RESULTS: The mean age was 41.25 years (±8.7) for patients and 33.5 years (±6.0) for controls. The mean CD4 count of patients was 191.5 cells/µL (±136.2). Patients had a significantly higher increase in RV-RA gradient as compared to controls (180.2% vs. 27.5%, p = 0.03). DISCUSSION: This pilot study suggests that it is feasible to use recumbent bicycle and transthoracic Doppler echocardiography for the evaluation of EIPH among HIV patients with dyspnea of unknown etiology. The study is too small to draw any broad conclusion. Further evaluation of this concept with a larger study is warranted.

Impact of buffering hypercapnic acidosis on cell wounding in ventilator-injured rat lungs.

We measured the effects of raising perfusate pH on ventilator-induced cell wounding and repair in ex vivo mechanically ventilated hypercapnic rat lungs. Lungs were randomized to one of three perfusate groups: 1) unbuffered hypercapnic acidosis, 2) bicarbonate-buffered hypercapnia, or 3) tris-hydroxymethyl aminomethane (THAM)-buffered hypercapnia. The membrane-impermeant label propidium iodide was added to the perfusate either during or after injurious ventilation providing a means to subsequently identify transiently wounded and permanently wounded cells in optical sections of subpleural alveoli. Normalizing perfusate pH in hypercapnic preparations attenuated ventilator-induced cell injury, particularly in THAM-buffered preparations. This was observed despite greater amounts of edema and impaired lung mechanics compared with other treatment groups. Protective effects of buffering of hypercapnic acidosis on injury and repair were subsequently confirmed in a cell scratch model. We conclude that buffering of hypercapnic acidosis attenuates plasma cell injury induced by mechanical hyperinflation.

Diagnosis and management of obesity hypoventilation syndrome in the ICU.

Obesity hypoventilation syndrome (OHS) is characterized by obesity, daytime hypercapnia, and sleep-disordered breathing in the absence of other known causes of hypercapnia. Because of the global obesity epidemic and the high prevalence of obstructive sleep apnea in the general population, critical care physicians are likely to encounter patients who have acute-on-chronic respiratory failure attributable to OHS in their clinical practice. In this article we define the clinical characteristics of OHS, review its pathophysiology, and discuss the morbidity and mortality associated with OHS. Finally, we offer treatment strategies during ICU management using noninvasive positive pressure ventilation that may guide the physician in the care of these challenging patients.