Teiko Toyoguchi

Histamine Release Induced by Antimicrobial Agents and Effects of Antimicrobial Agents on Vancomycin‐induced Histamine Release from Rat Peritoneal Mast Cells

Vancomycin and certain fungicides may cause anaphylactoid reactions. We investigated the effects of vancomycin, miconazole and fluconazole on histamine release in rat peritoneal mast cells. Vancomycin and miconazole provoked histamine release in a dose‐dependent manner. In contrast, fluconazole did not provoke histamine release at concentrations of 3 times 10−6 ‐ 3 times 10 −3 m.

Present Status of YU-AMS System

A new compact accelerator mass spectrometry (AMS) system has been installed in the Kaminoyama Research Institute at Yamagata University (YU). The AMS system is based on a 0.5MV Pelletron accelerator developed by the National Electrostatics Corporation. An automated acid-alkali-acid (AAA) treatment system and an automated graphitization line were also installed in the same facility for sample preparation. Performance tests of the YU-AMS system were carried out by measuring the C-series standard samples (C1–C8) and HOxII provided by IAEA and NIST, respectively. We evaluated the YU-AMS system by comparing the radiocarbon ages of Japanese tree rings with dendrochronologically determined calendar ages with calibration data. We also carried out some performance tests using a control serum and a 14 C-labeled drug (oxaliplatin).

Effects of Serum Sodium Concentrations on Nausea and Vomiting after Moderately Emetogenic Chemotherapy

 Chemotherapy-induced nausea and vomiting (CINV) is the most unbearable adverse effect of chemotherapy. The antiemesis guidelines of the National Comprehensive Cancer Network indicate that hyponatremia is a risk factor for CINV, although the relationship between the incidence of CINV and hyponatremia has not been sufficiently studied. This two-center prospective observational study evaluated whether low serum sodium concentrations were a risk factor for CINV. The study included 34 patients who were scheduled to receive first-line carboplatin- or oxaliplatin-based chemotherapy for gynecological or colorectal cancers. Patient diaries were used to record the daily incidences of CINV events during a 5-day period. The patients were divided based on the median serum sodium concentration into a low Na+ group (<141 mEq/L) and a high Na+ group (≥141 mEq/L). The incidences of delayed nausea were 27.8% in the high Na+ group and 62.5% in the low Na+ group (p=0.042), with complete control rates (no vomiting, rescue medication, or grade 2 nausea) of 77.8% and 43.8%, respectively (p=0.042). The time to complete control failure in each group was analyzed using the Kaplan-Meier method, which revealed a significantly shorter time in the low Na+ group (p=0.03). Therefore, these results indicate that low serum sodium concentrations may increase the risk of CINV.

Occurrence Rates of Gram-negative Bacteria after Treatment with Anti Methicillin-resistant Staphylococcm Aureus Agents

Methicillin-resistant Staphylococcus aureus (MRSA) is a gram-positive bacterium, and the treatment of patients with MRSA has induced microbial substitution. Regarding antibiotics used for treatment, vancomycin (VCM) has an antibacterial action only against gram-positive bacteria, while arbekacin (ABK) has an antibacterial action against both gram-positive and gram-negative bacteria. In view of this, we supposed that there would be a difference in gram-negative bacteria occurrence rates between patients administered VCM and those administered ABK and tested this supposition by comparing the appearance of gram-negative bacteria in these two patient groups. While gram-negative bacteria were newly detected in 45% of patients after receiving VCM, no patients receiving ABK showed any new gram-negative bacteria. On the other hand, gram-negative bacteria were still detected after administering ABK in patients who had gram-negative bacteria beforehand. This finding suggests that ABK may not be a superior agent when gram-negative bacteria are already present.

Pharmacokinetics of High Dose Methotrexate : 1 : In Acute Renal Failure

Acute renal failure developed in a 5 year-old girl during the fifth course of high dose methotrexate (MTX) treatment for osteosarcoma. She showed oliguria, and the serum MTX concentration, BUN and Scr were 461 μmoles/1, 50 mg/dl and 2.6 mg/dl, respectively, at 27 hr after infusion.Massive leucovorin calcium rescure, direct hemoperfusion, hemodialysis and plasma exchange therapies were successfully treated and she recovered gradually.Neither toxic bone marrow suppression nor side effect of massive leucovorin calcium appeared.The pharmacokinetic analysis of MTX during the renal failure and the dialysis treatment was investigated.

Dissolution rates and blood concentration of griseofulvin in rabbits.

Weight variation test, disintegration test, and dissolution test were made as quality tests for 6 different preparations of griseofulvin. In the dissolution test, water/ethanol (1: 2, v/v) mixture and double-layer solution of water/n-octanol (1:1), water/benzene (1: 1) or water/ethyl acetate (1: 1) were used as dissolution mediums. The absorption of griseofulvin was studied by measuring the blood concentration in rabbits.The dissolution rates and the parameters of the blood levels were different among the preparations. However, the correlation was observed between the. results of the dissolution test using the water/n-octanol solution as dissolution medium and the AUC-time curve calculated from the blood concentration in rabbits.