Kyohei Miyazaki

Influenza Viral Load and Peramivir Kinetics after Single Administration and Proposal of Regimens for Peramivir Administration against Resistant Variants

ABSTRACT We estimated the efficacy of the current single administration of peramivir on the basis of peramivir pharmacokinetics in the upper respiratory tract (URT) and determined the predictive peramivir concentration-time curve to assess its efficacy against viruses with decreased susceptibility to neuraminidase inhibitors. Serum, nasal swab, or aspiration samples were collected from 28 patients treated with 10 mg/kg body weight peramivir. The sequential influenza viral RNA load and susceptibility after peramivir administration were measured using a quantitative real-time reverse transcription-PCR and neuraminidase inhibition assay. The peramivir concentrations in the serum and URT after a single administration at 10 mg/kg were measured, and the predictive blood and URT peramivir concentration-time curves were determined to assess various administration regimens against resistant variants. The peramivir concentration decreased to <0.1% of the maximum concentration of drug in serum (Cmax) at 24 h after administration. Rapid elimination of peramivir from the URT by 48 h after administration may contribute to an increase in the influenza A viral load after day 3 but not to a decrease in the influenza B viral load, despite the absence of a decrease in the susceptibility to peramivir. A longer maintenance of a high level of peramivir in the URT is expected by divided administration rather than once-daily administration. When no clinical improvement is observed in patients with normal susceptibility influenza A and B, peramivir readministration should be considered. In severe cases caused by resistant variants, better inhibitory effectiveness and less frequent adverse events are expected by divided administration rather than once-daily administration with an increased dosage.

Resistance factors for the treatment of immunoglobulin A nephropathy with diffuse mesangial proliferation.

Some patients with severe immunoglobulin A nephropathy (IgAN) are resistant to multi‐drug combination therapy; however, there have been few reports on the risk factors for non‐responsiveness to treatment for severe IgAN. We, therefore, evaluated the risk factors for non‐responsiveness to treatment in cases of severe IgAN.

The efficacy of recombinant human soluble thrombomodulin for the treatment of shiga toxin associated hemolytic uremic syndrome model mice

BACKGROUND Recombinant human soluble thrombomodulin (rhTM) is a promising therapeutic natural anticoagulant that is comparable to antithrombin, tissue factor pathway inhibitor and activated protein C. In order to clarify the efficacy of rhTM for the treatment of typical hemolytic uremic syndrome (t-HUS), we examined changes in renal damage in t-HUS mice treated with rhTM or vehicle alone. METHODS We used severe and moderate t-HUS mice injected with shiga toxin (Stx) and lipopolysaccharide (LPS). The severe t-HUS mice were divided into two subgroups [an rhTM subgroup (Group A) and a saline subgroup (Group B)] along with the moderate t-HUS mice [an rhTM subgroup (Group C) and a saline subgroup (Group D)]. Groups E and F were healthy mice treated with rhTM or saline, respectively. RESULTS All mice in Group B died at 80-90 h post-administration of Stx2 and LPS whereas all mice in Group A remained alive. Loss of body weight, serum creatinine level, endothelial injury and mesangiolysis scores at 24 h after administration in the t-HUS mice treated with rhTM were lower than those in t-HUS mice treated with saline. The levels of hemoglobin at 6 h and platelet counts at 24 h after administration in Group A were higher than those in Group B. Serum interleukin (IL)-6, IL-1β and tumor necrotic factor (TNF)-α levels at 24 h after administration in Group A were lower than those in Group B. Serum C5b-9 levels at 24 h after the administration and serum fibrinogen degradation product (FDP) at 72 h after the administration of Stx2 and LPS were lower in Group A than in Group B. CONCLUSIONS These results indicate that rhTM might afford an efficacious treatment for t-HUS model mice via the inhibition of further thrombin formation and amelioration of hypercoagulant status.

Rituximab and low-dose cyclosporine combination therapy for steroid-resistant focal segmental glomerulosclerosis.

We investigated the efficacy of rituximab and low‐dose cyclosporine combination therapy for focal segmental glomerulosclerosis (FSGS) in children with steroid‐resistant nephrotic syndrome (SRNS).

Establishment of a method for evaluating endothelial cell injury by TNF-[alpha] in vitro for clarifying the pathophysiology of virus-associated acute encephalopathy

Background:Virus-associated acute encephalopathy (VAE) is a severe central nervous system complication caused by common viral infections in children. The pathophysiology of VAE is thought to be endothelial injury. This study was designed to establish an in vitro VAE model for evaluating endothelial injury caused by the proinflammatory cytokine TNF-α.Methods:Transwell-grown human umbilical vein endothelial cells (HUVECs) monolayers were incubated with serially diluted TNF-α. Transendothelial electrical resistance (TER) was measured using impedance spectroscopy. Permeability changes of HUVECs after TNF-α treatment were determined by fluorescein isothiocyanate (FITC)-conjugated dextran. Moreover, TNF-α-induced morphological changes in claudin-5 and apoptosis were observed by immunofluorescent staining.Results:The decrease in TER, time of TER recovery to baseline, and increase in permeability were all dependent on TNF-α concentration. Immunofluorescent staining showed that claudin-5 was delocalized after TNF-α treatment in a dose-dependent manner. In addition, some apoptotic cells were observed at high TNF-α concentrations.Conclusion:TER measurement combined with a permeability assay could be useful for evaluating vascular endothelial cell permeability in an in vitro model. These evaluation methods will contribute to both the development of specific treatments focusing on vascular permeability, and the search for a novel therapeutic strategy in VAE treatment.

Rituximab and low‐dose cyclosporine combination therapy for steroid‐resistant FSGS

We investigated the efficacy of rituximab and low‐dose cyclosporine combination therapy for focal segmental glomerulosclerosis (FSGS) in children with steroid‐resistant nephrotic syndrome (SRNS).

Incidence and prognosis of systemic lupus erythematosus in a 35 year period in Fukushima, Japan

We examined the epidemiology, clinical manifestations, and prognosis of pediatric systemic lupus erythematosus (SLE) in Fukushima Prefecture, Japan over a 35 year period.

Quantitative analysis of influenza A (H3N2) E119V and R292K variants in clinical specimens by real-time reverse transcription polymerase chain reaction.

BACKGROUND Because influenza virus isolates after cell culture are required to determine their susceptibility to neuraminidase inhibitors, the differences in normal or low-susceptibility variant population frequencies between clinical samples and isolates have not been considered. OBJECTIVES To identify variations in low-susceptibility populations in clinical samples after initiation of oseltamivir and zanamivir therapy by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). STUDY DESIGN We measured the populations of the low-susceptibility influenza A H3N2 variants E119V and R292K by qRT-PCR using 305 nasal aspiration samples collected over time from 13, 16, and 11 patients treated with no neuraminidase inhibitors, oseltamivir, and zanamivir, respectively. The variant population in the isolates was also determined when the population of low-susceptibility variants in the clinical samples increased following treatment. Moreover, the susceptibility of all isolates was measured. RESULTS The E119V variant was detected in only one patient during oseltamivir therapy, exhibiting decreased susceptibility to oseltamivir. Prior to treatment, R292K variants were detected in all clinical samples; however, they comprised only a small fraction of the total population. The proportion of the R292K variant in clinical samples increased for 6/27 (22.2%) patients treated with oseltamivir or zanamivir, whereas an increase in the proportion of the R292K variant in virus isolates was observed in only one patient. CONCLUSIONS Discrepancies in the proportion of R292K variants between clinical samples and isolates should be suspected in clinical settings. qRT-PCR is useful for quantitative analysis of drug-resistant influenza virus and for immediate notification of the result.