Hospital-based registry data, including patients’ information collected by academic societies or government based research groups, were previously used for clinical research in Japan. Now, real-world data routinely obtained in healthcare settings are being used in clinical epidemiology and pharmacoepidemiology. Real-world data include a database of claims originating from health insurance associations for reimbursement of medical fees, diagnosis procedure combinations databases for acute inpatient care in hospitals, a drug prescription database, and electronic medical records, including patients’ medical information obtained by doctors, derived from electronic records of hospitals. In the past ten years, much evidence of clinical epidemiology and pharmacoepidemiology studies using real-world data has been accumulated. The purpose of this review was to introduce clinical epidemiology and pharmacoepidemiology approaches and studies using real-world data in Japan.

A bacterium with a “mouth”-like pit structure isolated for the first time in the history of microbiology was a Gram-negative rod, containing glycosphingolipids in the cell envelope, and named Sphingomonas sp. strain A1. The pit was dynamic, with repetitive opening and closing during growth on alginate, and directly included alginate concentrated around the pit, particularly by flagellins, an alginate-binding protein localized on the cell surface. Alginate incorporated into the periplasm was subsequently transferred to the cytoplasm by cooperative interactions of periplasmic solute-binding proteins and an ATP-binding cassette transporter in the cytoplasmic membrane. The mechanisms of assembly, functions, and interactions between the above-mentioned molecules were clarified using structural biology. The pit was transplanted into other strains of sphingomonads, and the pitted recombinant cells were effectively applied to the production of bioethanol, bioremediation for dioxin removal, and other tasks. Studies of the function of the pit shed light on the biological significance of cell surface structures and macromolecule transport in bacteria.