High myopia at high altitudes

Background: Optic nerve sheath diameter (ONSD) increases significantly at high altitudes, and is associated with the presence and severity of acute mountain sickness (AMS). Exposure to hypobaria, hypoxia, and coldness when hiking also impacts intraocular pressure (IOP). To date, little is known about ocular physiological responses in trekkers with myopia at high altitudes. This study aimed to determine changes in the ONSD and IOP between participants with and without high myopia (HM) during hiking and to test whether these changes could predict symptoms of AMS.Methods: Nine participants with HM and 18 without HM participated in a 3-day trek of Xue Mountain. The ONSD, IOP, and questionnaires were examined before and during the trek of Xue Mountain.Results: The ONSD values increased significantly in both HM (p = 0.005) and non-HM trekkers (p = 0.018) at an altitude of 1,700 m. In the HM group, IOP levels were greater than those in the non-HM group (p = 0.034) on the first day of trekking (altitude: 3,150 m). No statistically significant difference was observed between the two groups for the values of ONSD. Fractional changes in ONSD at an altitude of 1,700 m were related to the development of AMS (rpb = 0.448, p = 0.019) and the presence of headache symptoms (rpb = 0.542, p = 0.004). The area under the ROC curve for the diagnostic performance of ONSD fractional changes at an altitude of 1,700 m was 0.859 for predicting the development of AMS and 0.803 for predicting the presence of headache symptoms.Conclusion: Analysis of changes in ONSD at moderate altitude could predict AMS symptoms before an ascent to high altitude. Myopia may impact physiological accommodation at high altitudes, and HM trekkers potentially demonstrate suboptimal regulation of aqueous humor in such environments

Oct-4 Expression Maintained Cancer Stem-Like Properties in Lung Cancer-Derived CD133-Positive Cells

CD133 (prominin-1), a 5-transmembrane glycoprotein, has recently been considered to be an important marker that represents the subset population of cancer stem-like cells. Herein we report the isolation of CD133-positive cells (LC-CD133+) and CD133-negative cells (LC-CD133−) from tissue samples of ten patients with non-small cell lung cancer (LC) and five LC cell lines. LC-CD133+ displayed higher Oct-4 expressions with the ability to self-renew and may represent a reservoir with proliferative potential for generating lung cancer cells. Furthermore, LC-CD133+, unlike LC-CD133−, highly co-expressed the multiple drug-resistant marker ABCG2 and showed significant resistance to chemotherapy agents (i.e., cisplatin, etoposide, doxorubicin, and paclitaxel) and radiotherapy. The treatment of Oct-4 siRNA with lentiviral vector can specifically block the capability of LC-CD133+ to form spheres and can further facilitate LC-CD133+ to differentiate into LC-CD133−. In addition, knock-down of Oct-4 expression in LC-CD133+ can significantly inhibit the abilities of tumor invasion and colony formation, and increase apoptotic activities of caspase 3 and poly (ADP-ribose) polymerase (PARP). Finally, in vitro and in vivo studies further confirm that the treatment effect of chemoradiotherapy for LC-CD133+ can be improved by the treatment of Oct-4 siRNA. In conclusion, we demonstrated that Oct-4 expression plays a crucial role in maintaining the self-renewing, cancer stem-like, and chemoradioresistant properties of LC-CD133+. Future research is warranted regarding the up-regulated expression of Oct-4 in LC-CD133+ and malignant lung cancer

Abstract 17321: Long-Term Exposures to Air Pollutants and Risk of Peripheral Arterial Occlusive Disease, a Nationwide 10-Year Follow-Up Cohort Study in Taiwan

Objective: Many studies had reported the association between air pollution and cardiovascular diseases. In this current study, we aimed to evaluate the risk of long-term exposure to air pollution (PM2.5, CO and NO2) to the development of PAOD. Methods: We linked two nation-scale databases, the national health insurance database and the air quality-monitoring database of Taiwan to conduct this cohort study between 2003 and 2013. Cox proportional regression with time-dependent model was used to evaluate the hazard ratio (HR) of air pollutants to PAOD. The residential areas were divided into four categories according to the daily average concentration of air pollutants, Q1 to Q4 (Q4 = the worst). The cumulative incidence of PAOD was examined by the Kaplain-Meier analysis with log-rank test. Results: A total of 1,598 PAOD cases were identified during the follow-up period with 98,540 non-PAOD ones (demographic characteristics were showed in Table 1). In the multivariate analysis, after adjusting for age, gender, urbanization level, residential area, baseline comorbidities, and drug use, the adjusted HRs were that PM2.5 = 1.14 (95% CI 1.13-1.16), NO2 = 1.03 (95% CI 1.02-1.04), and CO = 2.35 (95% CI 1.95-2.84), respectively (Table 2). The Kaplain-Meier analysis showed that CO concentration was strongly associated with cumulative incidence rate of PAOD during the follow-up period (Figure 1). Conclusion: Besides of well-known risk factors, air pollutants may also play a potential role in PAOD pathogenesis. </jats:p