Evaluation of the meropenem dosage and administration schedule in patients with bacteremia initial therapy.

BACKGROUND: The standard meropenem (MEPM) regimen allowed by insurance in Japan is 0.5 g two or three times a day. Differences in dosages and administration schedules in Japan were evaluated. METHODS: Patients with bacteremia for whom MEPM was used as the initial treatment at our institution between 2016 and 2021 were included. We retrospectively investigated patients classified into two groups: those treated according to severe infections (high-dose groupand others (low-dose group). After propensity score matching, we compared the probability of achieving free drug blood levels above the minimum inhibitory concentration (MIC) in 24 h (%fT > MIC) and outcomes. RESULTS: The probability of 100% fT > MIC was significantly higher in the high-dose group (96.4% vs 74.5%, odds ratio [OR] = 0.3, 95% confidence interval [CI] = 0.2-0.4, P = < 0.001). Regarding outcomes, the 30-day mortality rate was significantly lower in the high-dose group (1.4% vs. 11.4%, OR = 8.0, 95% CI = 1.5-43.7, P = 0.019). CONCLUSIONS: To improve outcomes in patients with bacteremia treated with MEPM, support for appropriate antimicrobial use is necessary for compliance with the dosage and administration schedule according to severe infections in initial treatment.

[Infection treatment caused by multiple-drug-resistant Pseudomonas aeruginosa in a patient undergoing allogeneic hematopoietic stem cell transplantation].

Infections caused by multiple-drug-resistant Pseudomonas aeruginosa (MDRP) are a clinically significant problem. We reported here the effective use of combination therapy in a patient with infection caused by MDRP according to an interventional treatment strategy suggested by a pharmacist. The patient was a 70-year-old male who underwent allogeneic hematopoietic stem cell transplantation. On day 45 after transplant, MDRP was newly isolated from urine, but the diagnosis at that time was colonization. On day 61, the patient developed a fever (> or =38.0 degrees C). In addition, laboratory data showed that C-reactive protein (CRP) was also increased. At the medical team conference, the pharmacist proposed the following treatment strategy for this infection. Aztreonam and amikacin were intravenously administered at doses of 2 g/day and 800 mg/day, respectively. The subsequent clinical course was well controlled, but the infection recurred and was aggravated. Aztreonam and ciprofloxacin were then intravenously administered at doses of 4 g/day and 600 mg/day, respectively, resulting in the alleviation of fever in the patient as well as a decrease in CRP and disappearance of MDRP isolates from urine on day 67; that is, MDRP infection was consequently well controlled. In conclusion, the combination therapy between aztreonam and amikacin, or ciprofloxacin may be clinically useful for severe infections of MDRP in compromised hosts.

Overexpression of plasma membrane-associated sialidase attenuates insulin signaling in transgenic mice.

Plasma membrane-associated sialidase is a key enzyme for ganglioside hydrolysis, thereby playing crucial roles in regulation of cell surface functions. Here we demonstrate that mice overexpressing the human ortholog (NEU3) develop diabetic phenotype by 18-22 weeks associated with hyperinsulinemia, islet hyperplasia, and increased beta-cell mass. As compared with the wild type, insulin-stimulated phosphorylation of the insulin receptor (IR) and insulin receptor substrate I was significantly reduced, and activities of phosphatidylinositol 3-kinase and glycogen synthase were low in transgenic muscle. IR phosphorylation was already attenuated in the younger mice before manifestation of hyperglycemia. Transient transfection of NEU3 into 3T3-L1 adipocytes and L6 myocytes caused a significant decrease in IR signaling. In response to insulin, NEU3 was found to undergo tyrosine phosphorylation and subsequent association with the Grb2 protein, thus being activated and causing negative regulation of insulin signaling. In fact, accumulation of GM1 and GM2, the possible sialidase products in transgenic tissues, caused inhibition of IR phosphorylation in vitro, and blocking of association with Grb2 resulted in reversion of impaired insulin signaling in L6 cells. The data indicate that NEU3 indeed participates in the control of insulin signaling, probably via modulation of gangliosides and interaction with Grb2, and that the mice can serve as a valuable model for human insulin-resistant diabetes.