A synergistic effect of P-glycoprotein (P-gp)/Abcb1a and breast cancer resistance protein (Bcrp)/Abcg2 was reported to limit the brain penetration of their common substrates. This study investigated this based on pharmacokinetics using Mdr1a/1b(Ϫ/Ϫ), Bcrp(Ϫ/Ϫ), and Mdr1a/1b(Ϫ/Ϫ)/ Bcrp(Ϫ/Ϫ) mice. Comparison of the brain-and testis-toplasma ratios (C brain /C plasma and C testis /C plasma , respectively) of the reference compounds quinidine and dantrolene for P-gp and Bcrp, respectively, indicates that impairment of either P-gp and Bcrp did not cause any change in the efflux activities of Bcrp or P-gp, respectively, at both the bloodbrain barrier (BBB) and blood-testis barrier (BTB). The C brain / C plasma and C testis /C plasma of the common substrates erlotinib, flavopiridol, and mitoxantrone were markedly increased in Mdr1a/1b(Ϫ/Ϫ)/Bcrp(Ϫ/Ϫ) mice even compared with Mdr1a/1b(Ϫ/Ϫ) and Bcrp(Ϫ/Ϫ) mice. Efflux activities by P-gp and Bcrp relative to passive diffusion at the BBB and BTB were separately evaluated based on the C brain /C plasma and C testis /C plasma in the knockout strains to the wild-type strain. P-gp made a larger contribution than Bcrp to the net efflux of the common substrates, but Bcrp activities were also significantly larger than passive diffusion. These parameters could reasonably account for the marked increase in C brain /C plasma and C testis /C plasma in the Mdr1a/1b(Ϫ/Ϫ)/ Bcrp(Ϫ/Ϫ) mice. In conclusion, the synergistic effect of P-gp and Bcrp on C brain /C plasma and C testis /C plasma can be explained by their contribution to the net efflux at the BBB and BTB without any interaction between P-gp and Bcrp.It is well accepted that the penetration of xenobiotic compounds into the brain and testis is restricted by the blood-brain barrier (BBB) and blood-testis barrier (BTB), respectively. The BBB is formed by brain capillary endothelial cells, whereas, in addition to endothelial cells, myoid and Sertoli cells form the BTB (Bart et al., 2002;Kusuhara and Sugiyama, 2005). Tight junctions between adjacent cells in the BBB and BTB are highly developed and limit the penetration of substances via the paracellular route. Moreover, drug transporters act as active barriers to limit the tissue penetration of substrates from the blood by extruding them back into the blood in the BBB and BTB and, thereby, modulating pharmacological or adverse reactions. It has been shown that ATP binding cassette (ABC) transporters, which are known to mediate resistance to anticancer drugs and antiviral drugs, are expressed in the BBB and BTB. These include P-glycoprotein (P-gp/MDR1/ABCB1), breast cancer resistance protein (BCRP/ABCG2), multidrug resistance-associated protein (MRP)-1/ABCC1, MRP2/ABCC2, MRP4/ABCC4, and MRP5/ABCC5 (Leggas et al., 2004;Zhang et al., 2004;Lee et al., 2005). In particular, P-gp is a well known transporter that plays a pivotal role in barrier function, and disruption of the Mdr1a gene, a predominant isoform expressed in the barriers, causes accumulation of a number of its substrates (S...

This study investigated the impact of the active efflux mediated by P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp) at the blood-brain barrier (BBB) on the predictability of the unbound brain concentration (C u,brain ) by the concentration in the cerebrospinal fluid (CSF) (C u,CSF ) in rats. C u,brain is obtained as the product of the total brain concentration and unbound fraction in the brain (f u,brain ) determined in vitro in brain slices. Twenty-five compounds, including P-gp and/or Bcrp substrates, were given a constant intravenous infusion, and their plasma, brain, and CSF concentrations were determined. P-gp and/or Bcrp substrates, such as verapamil, loperamide, flavopiridol, genistein, quinidine, dantrolene, daidzein, cimetidine, and pefloxacin, showed a higher CSF-to-brain unbound concentration ratio (K p,uu,CSF/brain ) compared with non-P-gp and non-Bcrp substrates. K p,uu,CSF/brain values of P-gp-specific (quinidine and verapamil) and Bcrp-specific (daidzein and genistein) substrates were significantly decreased in Mdr1a/ 1b(Ϫ/Ϫ) and Bcrp(Ϫ/Ϫ) mice, respectively. Furthermore, consistent with the contribution of P-gp and Bcrp to the net efflux at the BBB, K p,uu,CSF/brain values of the common substrates (flavopiridol and erlotinib) were markedly decreased in Mdr1a/ 1b(Ϫ/Ϫ)/Bcrp(Ϫ/Ϫ) mice, but only moderately or weakly in Mdr1a/1b(Ϫ/Ϫ) mice and negligibly in Bcrp(Ϫ/Ϫ) mice. In conclusion, predictability of C u,brain by C u,CSF decreases along with the net transport activities by P-gp and Bcrp at the BBB. C u,CSF of non-P-gp and non-Bcrp substrates can be a reliable surrogate of C u,brain for lipophilic compounds.

No abstract

We have developed a system to analyze the specific protein kinase activity of herpes simplex virus 1 Us3 in vitro and shown that Us3 directly phosphorylates viral proteins UL34, ICP22, and Us9 and the cellular protein Bad, previously reported to be putative substrates. Using this system, we determined the phosphorylation sites of UL34 and identified UL31 as a previously unreported, novel substrate of Us3. This system will be useful for further identification of Us3 substrates and their phosphorylation sites, clarification of the role of Us3 in viral replication, and identification of additional Us3 function(s).

ABSTRACT-Supplemental doses of antithrombin (AT) are widely used to treat sepsis-induced disseminated intravascular coagulation (DIC) in Japan. However, evidence on the benefits of ATsupplementation for DIC is insufficient. This multicenter retrospective observational study aimed to clarify the effect of AT supplementation on sepsis-induced DIC using propensity score analyses. Data from 3,195 consecutive adult patients admitted to 42 intensive care units for severe sepsis treatment were retrospectively analyzed; 1,784 patients were diagnosed with DIC (n ¼ 715, AT group; n ¼ 1,069, control group). Inverse probability of treatment-weighted propensity score analysis indicated a statistically significant association between AT supplementation and lower in-hospital all-cause mortality (n ¼ 1,784, odds ratio [95% confidence intervals]: 0.748 [0.572-0.978], P ¼ 0.034). However, quintile-stratified propensity score analysis (n ¼ 1,784, odds ratio: 0.823 [0.646-1.050], P ¼ 0.117) and propensity score matching analysis (461 matching pairs, odds ratio: 0.855 [0.649-1.125], P ¼ 0.263) did not show this association. In the early days after intensive care unit admission, the survival rate was statistically higher in the propensity score-matched AT group than in the propensity score-matched control group (P ¼ 0.007). In DIC patients without concomitant heparin administration, similar results were observed. In conclusion, AT supplementation may be associated with reduced in-hospital all-cause mortality in patients with sepsis-induced DIC. However, the statistical robustness of this connection was not strong. In addition, although the number of transfusions needed in patients with AT supplementation increased, severe bleeding complications did not.

SummaryTo clarify the role of c-Mpl ligand (thrombopoietin: TPO) in liver cirrhosis (LC), we examined serum TPO levels (sTPO) in patients with LG (N = 44), chronic hepatitis (CH; N = 13) and healthy controls (N = 41) by an enzyme-linked immunosorbent assay. Although platelet counts of all LC patients (89 ± 59 × 109/1; mean ± SD) were lower than those of controls and CH patients, sTPO levels in LC patients (1.23 ± 0.51 fmol/ml) were the same as those in controls (1.22 ± 0.37) and CH patients (1.18 ± 0.36). Platelet counts were significantly higher in splenectomized patients than in unsplenectomized patients, but the sTPO level did not differ between these two groups. In LC patients, the sTPO level was not correlated with the platelet count, but was correlated with prothrombin time, activated partial thromboplastin time, and total bilirubin, indicating that production of TPO in the liver decreases slightly with the development of liver dysfunction. Our findings suggest that production of TPO is maintained in LC patients and their thrombocytopenia is not due to a defect in platelet production.

No abstract

Severe sepsis is a major concern in the intensive care unit (ICU), although there is very little epidemiological information regarding severe sepsis in Japan. This study evaluated 3195 patients with severe sepsis in 42 ICUs throughout Japan. The patients with severe sepsis had a mean age of 70 ± 15 years and a mean Acute Physiology and Chronic Health Evaluation II score of 23 ± 9. The estimated survival rates at 28 and 90 days after ICU admission were 73.6 and 56.3 %, respectively.Electronic supplementary materialThe online version of this article (doi:10.1186/s40560-016-0169-9) contains supplementary material, which is available to authorized users.