Immobilization osteoporosis (IOP)is a common complication in clinic and cosmonauts. It severely impaired the patients ant the cosmonauts. The causes of IOP are weightless,immoblization and bed rest.Excercise therapy is very important for IOP. The etiology andpathogenesis of IOP are introduced in this article. the effects, mechanism and methods of the exercise therapy for preventing and treating IOP arealso discussed.

Ichthyosis refers to a group of skin diseases characterized by abnormal keratinization of the epidermis,resulting in dryness,roughness and scale of the skin.A girl with ichthyosis,who presented with skin ulcers and infection of the right dorsal foot,was admitted to our department.An autologous razor-thin skin grafting procedure was performed to repair the skin ulcers after debridement and vacuum sealing drain.After 8 months of follow-up,both the donor and recipient site healed well and there were no newly formed ulcers or infections.Although the skin quality of ichthyosis is poor,the lesion area can still be used as donor or recipient cite.

Dihydrofolate reductase (DHFR), a housekeeping enzyme in primary metabolism, has been extensively studied as a model of acid-base catalysis and a clinic drug target. Herein, we investigated the enzymology of a DHFR-like protein SacH in safracin (SAC) biosynthesis, which reductively inactivates hemiaminal pharmacophore-containing biosynthetic intermediates and antibiotics for self-resistance. Furthermore, based on the crystal structure of SacH-NADPH-SAC-A ternary complexes and mutagenesis, we proposed a catalytic mechanism that is distinct from the previously characterized short-chain dehydrogenases/reductases-mediated inactivation of hemiaminal pharmacophore. These findings expand the functions of DHFR family proteins, reveal that the common reaction can be catalyzed by distinct family of enzymes, and imply the possibility for the discovery of novel antibiotics with hemiaminal pharmacophore.