Screening Level of PAHs in Sediment Core from Lake Hongfeng, Southwest China

Using data from a 25-year retrospective of polycyclic aromatic hydrocarbons (PAHs) in sediment core from Lake Hongfeng, Southwest China, their possible sources and potential toxicologic significance were investigated. The total PAH concentrations (16 priority PAHs as proposed by the United States Environmental Protection Agency) in sediments ranged from 2936.1 to 5282.3 ng/g and gradually increased from the analyzed deeper sediments to surface sediments. PAHs were dominated by low molecular-weight components, especially phenanthrene (PHEN) and fluorene (FLU). However, a significantly increased number of high molecular-weight (HMW) PAHs was found in upper segments. The temporal trends of individual PAH species suggest that there may have been a change in energy use from low- to high-temperature combustion, especially after approximately 2001. PAH input to Lake Hongfeng originated mainly from domestic coal combustion and biomass burning, whereas fuel combustion characteristics have also been found in recent years. Sediment-quality assessment implied that potential adverse biologic impact could be a probability for most low-ring PAHs (including naphthalene, acenaphthylene, acenaphthylene, FLU, PHEN, and anthracene). Nevertheless, more concern should be paid to HMW PAHs in the future due to their rapidly increasing trends in upper sediments. Because only one core was analyzed in this study, more work is needed to confirm the sources and toxicity of PAHs in Lake Hongfeng

Target Deletion of the Cytoskeleton-Associated Protein Palladin Does Not Impair Neurite Outgrowth in Mice

Palladin is an actin cytoskeleton–associated protein which is crucial for cell morphogenesis and motility. Previous studies have shown that palladin is localized to the axonal growth cone in neurons and may play an important role in axonal extension. Previously, we have generated palladin knockout mice which display cranial neural tube closure defect and embryonic lethality before embryonic day 15.5 (E15.5). To further study the role of palladin in the developing nervous system, we examined the innervation of palladin-deficient mouse embryos since the 200 kd, 140 kd, 90–92 kd and 50 kd palladin isoforms were undetectable in the mutant mouse embryo brain. Contrary to the results of previous studies, we found no inhibition of the axonal extension in palladin-deficient mouse embryos. The cortical neurons derived from palladin-deficient mice also showed no significant difference in neurite outgrowth as compared with those from wild-type mice. Moreover, no difference was found in neurite outgrowth of neural stem cell derived-neurons between palladin-deficient mice and wild-type mice. In conclusion, these results suggest that palladin is dispensable for normal neurite outgrowth in mice

The evaluation of risk for obstructive sleep apnea in patients with type 2 diabetes

Cilj istraživanja je procijeniti rizik za opstrukcijsku apneju tijekom spavanja (engl. Obstructive sleep apnea, OSA) u bolesnika sa šećernom bolešću tipa 2, s pomoću STOP upitnika (engl. Snoring, Tiredness, Observed, Pressure; STOP). S pomoću Epworthove ljestvice pospanosti (ESS) procijenjena je prekomjerna dnevna pospanost i ispitana povezanost pospanosti i rizika za OSA-u u bolesnika sa šećernom bolešću tipa 2. Dosadašnja istraživanja pokazala su da oštećena tolerancije glukoze i šećerna bolest tipa 2 predstavljaju čimbenik rizika za OSA-u, ali i da OSA predstavlja čimbenik rizika za šećernu bolest tipa 2. U našem istraživanju sudjelovala su 252 ispitanika sa šećernom bolešću tipa 2, koji su bili anketirani za vrijeme redovitih pregleda u Kliničkom bolničkom centru Split. Rezultati našeg istraživanja pokazali su da je 156 ispitanika (61,9%) imalo povećan rizik za OSA-u prema rezultatima STOP upitnika. Nadalje, ispitanici koji su imali povećani rizik u odnosu na ispitanike koji nisu imali rizik za OSA-u bili su stariji (65 vs. 61 godina, p < 0,05), imali viši indeks tjelesne mase (28,6 ± 5,1 vs. 26,5 ± 4,1, p < 0,001), veći opseg vrata (41,5 ± 4,7 vs. 39,6 ± 6,2, p < 0,009) i bili pospaniji prema rezultatima ESS (5,3 ± 3,1 vs. 3,9 ± 2,5, p < 0,001). Uz šećernu bolest, većina ispitanika imala je i pridružene bolesti: arterijska hipertenzija (46%), gastroezofagealna refluksna bolest (28%), depresija (10%) i astma (8%). OSA je dio širokoga spektra poremećaja disanja tijekom spavanja koja se dovodi u vezu s metaboličkim poremećajima poput šećerne bolesti tipa 2, a epidemiološki podaci o zastupljenosti OSA u Hrvatskoj su nedostatni. Ovo istraživanje ukazuje na potrebu provođenja probira za OSA u bolesnika sa šećernom bolešću tipa 2, koristeći STOP upitnik.The aim of this study was to evaluate the risk for obstructive sleep apnea (OSA) in patients with type 2 diabetes using the STOP questionnaire (Snoring, Tiredness, Observed, Pressure; STOP). Excessive daytime sleepiness was evaluated with the Epworth sleepiness scale (ESS). Previous studies support the idea that glucose intolerance and type 2 diabetes might represent risk factors for OSA, as well as the idea of OSA being the risk factor for type 2 diabetes. A total of 252 patients with type 2 diabetes were surveyed during the regular follow-up in the Regional Centre for Diabetes, Endocrinology and Metabolic Diseases of Split University Hospital. The results of our study indicate that 156 patients (61.9%) had increased risk for OSA according to STOP questionnaire score. In addition, those at high risk for OSA were older (65 vs. 61 years of age, p < 0.05), had higher body mass index (BMI, 28.6 ± 5.1 vs. 26.5 ± 4.1, p < 0.001), higher neck circumference (41.5 ± 4.7 vs. 39.6 ± 6.2, p < 0.009), and had excessive daytime sleepiness according to the ESS score (5.3 ± 3.1 vs. 3.9 ± 2.5, p < 0.001). Individuals with type 2 diabetes reported to have comorbidities, mainly hypertension (46%), gastroesophageal reflux disease (28%), depression (10%), and asthma (8%). Based on current evidence from literature, OSA could be related to clinical conditions such as diabetes and essential hypertension. More epidemiological data are needed to establish the prevalence of OSA in Croatian patients with type 2 diabetes. Our findings indicate the relevance of STOP questionnaire use as a screening tool for obstructive sleep apnea in patients with type 2 diabetes in Croatia

Evaluation and intercomparison of global atmospheric transport models using Rn-222 and other short-lived tracers

Simulations of Rn-222 and other short-lived tracers are used to evaluate and intercompare the representations of convective and synoptic processes in 20 global atmospheric transport models. Results show that most established three-dimensional models simulate vertical mixing in the troposphere to within the constraints offered by the observed mean Rn-222 concentrations and that subgrid parameterization of convection is essential for this purpose. However, none of the models captures the observed variability of Rn-222 concentrations in the upper troposphere, and none reproduces the high Rn-222 concentrations measured at 200 hPa over Hawaii. The established three-dimensional models reproduce the frequency and magnitude of high- Rn-222 episodes observed at Crozet Island in the Indian Ocean, demonstrating that they can resolve the synoptic-scale transport of continental plumes with no significant numerical diffusion. Large differences between models are found in the rates of meridional transport in the upper troposphere (interhemispheric exchange, exchange between tropics and high latitudes). The four two-dimensional models which participated in the intercomparison tend to underestimate the rate of vertical transport from the lower to the upper troposphere but show concentrations of Rn-222 in the lower troposphere that are comparable to the zonal mean values in the three-dimensional models