Fundamental differences between Arctic and Antarctic ozone depletion

Antarctic ozone depletion is associated with enhanced chlorine from anthropogenic chlorofluorocarbons and heterogeneous chemistry under cold conditions. The deep Antarctic “hole” contrasts with the generally weaker depletions observed in the warmer Arctic. An unusually cold Arctic stratospheric season occurred in 2011, raising the question of how the Arctic ozone chemistry in that year compares with others. We show that the averaged depletions near 20 km across the cold part of each pole are deeper in Antarctica than in the Arctic for all years, although 2011 Arctic values do rival those seen in less-depleted years in Antarctica. We focus not only on averages but also on extremes, to address whether or not Arctic ozone depletion can be as extreme as that observed in the Antarctic. This information provides unique insights into the contrasts between Arctic and Antarctic ozone chemistry. We show that extreme Antarctic ozone minima fall to or below 0.1 parts per million by volume (ppmv) at 18 and 20 km (about 70 and 50 mbar) whereas the lowest Arctic ozone values are about 0.5 ppmv at these altitudes. At a higher altitude of 24 km (30-mbar level), no Arctic data below about 2 ppmv have been observed, including in 2011, in contrast to values more than an order of magnitude lower in Antarctica. The data show that the lowest ozone values are associated with temperatures below −80 °C to −85 °C depending upon altitude, and are closely associated with reduced gaseous nitric acid concentrations due to uptake and/or sedimentation in polar stratospheric cloud particles

Patients with clinically metabolically healthy obesity are not necessarily healthy subclinically: further support for bariatric surgery in patients without metabolic disease?

Background: Nonalcoholic fatty liver disease (NAFLD) increases the risk of liver cirrhosis and hepatocellular carcinoma and is also strongly correlated with extrahepatic diseases, including cardiovascular disease and type 2 diabetes. This risk of NAFLD among obese individuals who are otherwise metabolically healthy is not well characterized. Objectives: To determine the prevalence and characteristics of NAFLD in individuals with metabolically healthy obesity. Setting: A tertiary, academic, referral hospital. Methods: All patients who underwent bariatric surgery with intraoperative liver biopsy from 2008 to 2015 were identified. Patients with preoperative hypertension, dyslipidemia, or prediabetes/diabetes were excluded to identify a cohort of metabolically healthy obesity patients. Liver biopsy reports were reviewed to determine the prevalence of NAFLD. Results: A total of 270 patients (7.0% of the total bariatric surgery patients) met the strict inclusion criteria for metabolically healthy obesity. The average age was 38 ± 10 years and the average body mass index was 47 ± 7 kg/m2. Abnormal alanine aminotransferase (>45 U/L) and asparate aminotransferase levels (>40 U/L) were observed in 28 (10.4%) and 18 (6.7%) patients, respectively. A total of 96 (35.5%) patients had NAFLD with NALFD Activity Scores 0 to 2 (n = 61), 3 to 4 (n = 25), and 5 to 8 (n = 10). A total of 62 (23%) patients had lobular inflammation, 23 (8.5%) had hepatocyte ballooning, 22 (8.2%) had steatohepatitis, and 12 (4.4%) had liver fibrosis. Conclusion: Even with the use of strict criteria to eliminate all patients with any metabolic problems, a significant proportion of metabolically healthy patients had unsuspected NAFLD. The need and clinical utility of routine screening of obese patients for fatty liver disease and the role of bariatric surgery in the management of NAFLD warrants further investigation

Comparative outcomes of bariatric surgery in patients with impaired mobility and ambulatory population

Purpose: This study aims to characterize complications, metabolic improvement, and change in ambulation status for patients with impaired mobility undergoing bariatric surgery. Material and methods: Individuals undergoing primary sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) from February 2008 to December 2015 were included. Impaired mobility (WC) was defined as using a wheelchair or motorized scooter for at least part of a typical day. The WC group was propensity score matched to ambulatory patients (1:5 ratio). Comparisons were made for 30-day morbidity and mortality and 1-year improvement in weight-related comorbidities. Results: There were 93 patients in the WC group matched to 465 ambulatory controls. The median operative time (180 vs 159 min, p = 0.003) and postoperative length of stay (4 vs 3 days, p ≤ 0.001) was higher in the WC group. There were no differences in readmission or all-cause morbidity within 30 days. The median percent excess weight loss (%EWL) at 1 year was similar (WC group, 65% available, 53% EWL vs AMB group, 73% available, 54% EWL); however, patients with impaired mobility were less likely to experience improvement in diabetes (76 vs 90%, p = 0.046), hypertension (63 vs 82%, p < 0.005), and obstructive sleep apnea (53 vs 71%, p < 0.001). Within the WC group, 62% had improvement in their mobility status, eliminating dependence on wheelchair or scooter assistance. Conclusion: Patients with both obesity and impaired mobility experience similar rates of perioperative morbidity and weight loss at 1 year compared to ambulatory controls. However, improvement in weight-related comorbidities may be less likely with impaired mobility

Median arcuate ligament syndrome in athletes

© 2016, Springer Science+Business Media New York. Background: Exercise-related transient abdominal pain (ETAP) is a common entity in young athletes. Most occurrences are due to a “cramp” or “stitch,” but an uncommon, and often overlooked, etiology of ETAP is median arcuate ligament syndrome (MALS). The initial presentation of MALS typically includes postprandial nausea, bloating, abdominal pain, and diarrhea, but in athletes, the initial presentation may be ETAP. Methods: We present a case series of three athletes who presented with exercise-related transient abdominal pain and were ultimately diagnosed and treated for MALS. Unlike other patients with median arcuate ligament syndrome, these athletes presented with exercise-induced pain, rather than the common postprandial symptoms. These symptoms persisted despite conservative measures. Work-up of patients with suspected MALS include a computed tomography or magnetic resonance angiography showing compression of the celiac artery with post-stenotic dilation, or a celiac artery ultrasound demonstrating increased velocities (\u3e200 cm/s2) with deep exhalation. Results: All patients underwent a laparoscopic median arcuate ligament release. Postoperatively, there were no complications, and all were discharged home on postoperative day #2. All patients have subsequently returned to athletics with resolution of their symptoms. Conclusion: ETAP is common in athletes and often resolves with preventative or conservative strategies. When ETAP persists despite these methods, alternative causes, including MALS, should be considered. A combination of a thorough history and physical exam, as well as radiographic data, is essential to make the appropriate diagnosis and treatment strategy

Exercise-related transient abdominal pain secondary to median arcuate ligament syndrome: a case report

© 2015 Taylor & Francis. Exercise-related transient abdominal pain is a common entity in young athletes. An uncommon aetiology of this type of pain is median arcuate ligament syndrome. This article details an 18-year-old field hockey player who presented with a 1-year history of exercise-related transient abdominal pain. Despite a trial of preventative strategies, the patient’s pain persisted, prompting surgical intervention. Following a laparoscopic median arcuate ligament release, the patient’s symptoms resolved. Therefore, when exercise-related transient abdominal pain persists despite precautionary measures, median arcuate ligament syndrome should be considered

Median arcuate ligament syndrome in athletes

© 2016, Springer Science+Business Media New York. Background: Exercise-related transient abdominal pain (ETAP) is a common entity in young athletes. Most occurrences are due to a “cramp” or “stitch,” but an uncommon, and often overlooked, etiology of ETAP is median arcuate ligament syndrome (MALS). The initial presentation of MALS typically includes postprandial nausea, bloating, abdominal pain, and diarrhea, but in athletes, the initial presentation may be ETAP. Methods: We present a case series of three athletes who presented with exercise-related transient abdominal pain and were ultimately diagnosed and treated for MALS. Unlike other patients with median arcuate ligament syndrome, these athletes presented with exercise-induced pain, rather than the common postprandial symptoms. These symptoms persisted despite conservative measures. Work-up of patients with suspected MALS include a computed tomography or magnetic resonance angiography showing compression of the celiac artery with post-stenotic dilation, or a celiac artery ultrasound demonstrating increased velocities (\u3e200 cm/s2) with deep exhalation. Results: All patients underwent a laparoscopic median arcuate ligament release. Postoperatively, there were no complications, and all were discharged home on postoperative day #2. All patients have subsequently returned to athletics with resolution of their symptoms. Conclusion: ETAP is common in athletes and often resolves with preventative or conservative strategies. When ETAP persists despite these methods, alternative causes, including MALS, should be considered. A combination of a thorough history and physical exam, as well as radiographic data, is essential to make the appropriate diagnosis and treatment strategy