大橋 篤

Abstract Introduction Indoxyl sulfate (IS) is a protein‐bound uremic toxin that causes uremic sarcopenia. IS has poor dialysis clearance; however, the addition of a binding competitor improves its removal efficiency. Methods Dialysis experiments were performed using N‐acetyl‐l‐tryptophan (L‐NAT) instead of l‐tryptophan (Trp) using pooled sera obtained from dialysis patients. The molecular structures of L‐NAT and Trp were similar to that of IS. Therefore, we examined whether Trp and L‐NAT were involved in muscle atrophy in the same manner as IS by performing culture experiments using a human myotube cell line. Results The removal efficiency of L‐NAT was the same as that of Trp. However, L‐NAT concentrations in the pooled sera increased at the end of the experiment. Trp (1 mM) decreased the area of human myocytes, similar to IS, whereas L‐NAT did not. Conclusion L‐NAT is a binding competitor with the ability to remove protein‐bound IS while preventing sarcopenia.

Cell-free and concentrated ascites reinfusion therapy (CART) is performed by collecting the ascites from the patient, followed by filtration and concentration. Thereafter, concentrated cell-free ascites is reinfused into the patient intravenously. The new type of machine, Plasauto μ, for managing the process of CART was launched onto the market. We have evaluated the machine through postmarketing clinical study in 17 patients with malignant ascites. The amounts of original and concentrated ascites were 3673 ± 1920 g and 439 ± 228 g, respectively. Recovery rates were acceptable regarding values of total protein, albumin, and IgG that were 55.6% ± 17.3%, 60.2% ± 20.8%, and 58.2% ± 20.5%, respectively. Recovery rates were positively associated with amounts of original ascites and negatively associated with total protein concentration. No adverse events related to the machine were observed. The new type of machine showed preferable performance in processing malignant ascites.