Areal distribution of water-insoluble particles in snow covers of the central mountainous area, Japan

The vertical snow samples collected from 6 locations (Iou-zen: 800m A.M.S.L; the nearest site from the Sea of Japan, Kongoudou-zan: 1300m, Nishi-Hodaka-Dake: 2200m; the Northern Japan Alps, Hachimori-yama: 2100m, Kiriga-mine: 2000m, Yatsuga-take: 2200m; the most inlying site) in the central mountainous area, Japan, during early spring season 2004, were analyzed for size-separated concentrations of water-insoluble particles in snow layers to investigation of long-range transportation of chemical substances from the Asian continent to high mountainous areas in Japan. Most of particles are less than 30 μm in diameter, the greater part of particles observed at the 6 locations were considered to be transported from the Asian continent sources as Asian dust (KOSA). The variation patterns of the vertical profiles of particle concentrations in snow layers were corresponding among each location. The concentrations of particles with less than 30 μm was gradually increased with increasing distance from the Sea of Japan to the Japan Alps, although, sharply-decreased at 3 sites located the monsoon-leeward of the Japan Alps, suggesting that the particles transported with monsoon were gradually removed from air and deposited in snow cover when the air parcel pass through the Japan Alps

New approaches in the diagnosis and treatment of latent tuberculosis infection

With nearly 9 million new active disease cases and 2 million deaths occurring worldwide every year, tuberculosis continues to remain a major public health problem. Exposure to Mycobacterium tuberculosis leads to active disease in only ~10% people. An effective immune response in remaining individuals stops M. tuberculosis multiplication. However, the pathogen is completely eradicated in ~10% people while others only succeed in containment of infection as some bacilli escape killing and remain in non-replicating (dormant) state (latent tuberculosis infection) in old lesions. The dormant bacilli can resuscitate and cause active disease if a disruption of immune response occurs. Nearly one-third of world population is latently infected with M. tuberculosis and 5%-10% of infected individuals will develop active disease during their life time. However, the risk of developing active disease is greatly increased (5%-15% every year and ~50% over lifetime) by human immunodeficiency virus-coinfection. While active transmission is a significant contributor of active disease cases in high tuberculosis burden countries, most active disease cases in low tuberculosis incidence countries arise from this pool of latently infected individuals. A positive tuberculin skin test or a more recent and specific interferon-gamma release assay in a person without overt signs of active disease indicates latent tuberculosis infection. Two commercial interferon-gamma release assays, QFT-G-IT and T-SPOT.TB have been developed. The standard treatment for latent tuberculosis infection is daily therapy with isoniazid for nine months. Other options include therapy with rifampicin for 4 months or isoniazid + rifampicin for 3 months or rifampicin + pyrazinamide for 2 months or isoniazid + rifapentine for 3 months. Identification of latently infected individuals and their treatment has lowered tuberculosis incidence in rich, advanced countries. Similar approaches also hold great promise for other countries with low-intermediate rates of tuberculosis incidence