Electronic cigarettes and awareness of their health effects -- Metachronous lung cancer: clinical characteristics and effects of surgical treatment -- Healthcare professionals' knowledge of influenza and influenza vaccination: results of a National Survey in Poland -- Benign acute childhood myositis during influenza B outbreak -- Serum diamine oxidase in pseudoallergy in the pediatric population -- Spontaneous elimination of hepatiits C virus infection -- Clinical manifestations of huge diaphragmatic hernias -- The diagnostics of human steroid hormone disorders -- Discriminant analysis of intracranial volumetric variables in patients with normal pressure hydrocephalus and brain atrophy -- Hoffa's fat pad abnormality in the development of knee osteoarthritis -- Index.