Iron is an essential element for organisms, but its solubility in soil is often extremely low. Previously, plants were considered to take up iron only after its reduction to ferrous ions. Takagi reported that oat and rice secrete chelating substances that solubilize ferric iron in the rhizosphere for efficient iron uptake. In 1978, Takemoto et al. reported the chemical structure of an iron-chelating compound secreted from barley roots, designated as mugineic acid. Mugineic acid and its derivatives, collectively known as mugineic acid family phytosiderophores (MAs), chelate ferric iron using octahedral hexacoordination. The specific iron uptake system by MAs in graminaceous plants was later classified by Römheld and Marschner as Strategy II, in contrast to Strategy I for reduction-based iron uptake by non-graminaceous plants. Further studies on MAs by Japanese researchers led to the identification of their biosynthetic pathways, corresponding enzymes and encoding genes, their regulation mechanisms, and the production of iron deficiency-tolerant and iron-rich crops.

It is now accepted that the pathogenesis of type 2 diabetes in East Asians including Japanese differs distinctly from that in Caucasians. Many non-obese individuals in Japan develop type 2 diabetes and present clinically with insufficient insulin secretion rather than a large increase in the insulin resistance. To understand the pathophysiology of this non-obese diabetes, we studied Goto-Kakizaki rats, a unique model of spontaneous non-obese diabetes, and identified mitochondrial dysfunction in pancreatic β-cells as a factor in decreased insulin secretion. Looking for a clinical treatment option, we focused on the incretins because of their glucose-dependent insulin stimulatory effect. Our findings have contributed to the understanding of incretin action and the development of incretin-associated therapeutics and shed light on the nature of East Asian diabetes and its optimal clinical treatment.

Thrombomodulin (TM) is an important regulator of intravascular blood coagulation, fibrinolysis, and inflammation. TM inhibits the procoagulant and proinflammatory activities of thrombin and promotes the thrombin-induced activation of protein C (PC) bound to the endothelial PC receptor (EPCR). Activated PC (APC) inactivates coagulation factors Va and VIIIa, thereby inhibiting blood clotting. APC bound to EPCR exerts anti-inflammatory and cytoprotective effects on vascular endothelial cells. TM promotes the activation of thrombin-activatable fibrinolysis inhibitor, and also protects cells in blood vessels from inflammation caused by pathogen-associated and damaged cell-associated molecules. Excessive anticoagulant, fibrinolytic, anti-inflammatory, and tissue regenerative effects in the TM-PC pathway are controlled by PC inhibitor. A recombinant TM drug (TM), a soluble form of natural TM developed from the cloned human TM gene, has been evaluated for efficacy in many clinical trials and approved as a treatment for disseminated intravascular coagulation (DIC) caused by diseases such as sepsis, solid tumors, hematopoietic tumors, and trauma. It is currently widely used to treat DIC in Japan.

This study explored the relationship between fall patterns and fall-related fractures in older adults. A cross-sectional survey was conducted among community-dwelling older adults in Maibara City, Japan, focusing on falls over the past three years. Among the 1,695 reported falls, 176 fractures occurred in 120 individuals. Backward or straight-down and sideways falls were more likely to result in fractures compared to forward falls, with odds ratios (95％ confidence interval) of 3.23 (2.08-5.02) and 3.68 (2.35-5.76), respectively. Falls triggered by slipping or loss of balance had higher fracture rates than those triggered by tripping. Specific fall patterns were associated with particular fractures, such as forearm and patella fractures from forward falls, spine fractures from backward or straight-down falls, and hip fractures from sideways falls. We conclude that the fracture risk varies significantly based on fall patterns, providing insights for enhancing fall prevention strategies.