The ATP-Binding Cassette Transporter-Mediated Efflux Transport of Ganciclovir at the Blood-Brain Barrier.

BACKGROUND AND OBJECTIVE: Recent studies have highlighted the key role of the ATP-binding cassette (ABC) transporters, including the P-glycoprotein (P-gp), the breast cancer resistance protein (BCRP), and the multi-drug resistance protein 4 (MRP4) in limiting the brain distribution of several antiviral agents. In this study, we investigated whether the inhibition of these transporters increases the permeability of the blood-brain barrier (BBB) to ganciclovir. METHODS: A microdialysis and high-performance liquid chromatographic method was developed to monitor the concentrations of unbound ganciclovir in the brain interstitial fluid and plasma, with and without the administration of ABC transporter inhibitors. Pharmacokinetic parameters, including the area under the plasma concentration-time curve from time 0 to time of the last measurable analyte concentration (AUC0-t,plasma), the area under the brain interstitial fluid concentration-time curve from time 0 to time of the last measurable analyte concentration (AUC0-t,brain), and the unbound brain-to-plasma concentration ratio (Kp,uu,brain) were calculated. RESULTS: The mean AUC0-t,plasma, AUC0-t,brain, and Kp,uu,brain in rats who received ganciclovir (30 mg/kg, intraperitoneal) alone were 1090 min·µg/mL, 150 min·µg/mL, and 14%, respectively. After the administration of tariquidar (inhibitor of P-gp), Ko143 (inhibitor of BCRP), or MK-571 (inhibitor of MRP4), the Kp,uu,brain of ganciclovir increased to 31 ± 2.1%, 26 ± 1.3%, and 32 ± 2.0%, respectively. CONCLUSIONS: The findings of this study suggest that ABC transporters P-gp, BCRP, and MRP4 mediate the efflux of ganciclovir at the BBB and that the inhibition of these transporters facilitates the penetration of the BBB by ganciclovir.

Effects of intravenous chemotherapy after TURBT for high-risk nonmuscle invasive bladder cancer: results of a retrospective study.

PURPOSE: This study compared the efficacy and safety of intravenous chemotherapy combined with intravesical chemotherapy versus intravesical chemotherapy alone for high-risk nonmuscle invasive bladder cancer (HRNMIBC) patients after transurethral resection of the bladder tumor (TURBT) surgery. METHODS: A retrospective analysis was performed on 349 HRNMIBC cases admitted to TangDu hospital between January 2014 and June 2019. After TURBT, 262 patients received intravesical chemotherapy alone, whereas 87 patients underwent intravesical chemotherapy in combination with intravenous chemotherapy. The recurrence rate and progression rate were assessed by Chi-square test, the prognostic factors for tumor recurrence were predicted by univariable and multivariable Cox hazards analyses, recurrence-free survival (RFS) and progression-free survival (PFS) were calculated using the Kaplan-Meier method. RESULTS: In this study, the recurrence rate was 24.7% (19/77) in the intravenous chemotherapy combined group and 41.6% (102/245) in the intravesical chemotherapy group, while the progression rate was 6.5% (5/77) and 14.3% (35/245) in the two groups respectively. The two groups differed significantly in recurrence rate (p = 0.007) while the progression rate did not show a significant difference (p = 0.071). Multivariable analyses revealed that additional intravenous chemotherapy treatment was an independent prognostic factor for tumor recurrence in the cohort (hazard ratio [HR], 0.495, 95% confidence interval [CI], 0.275-0.892, p = 0.019). Kaplan-Meier curves showed significant differences in RFS and PFS between the two groups, with a log-rank P value of p < 0.005 and p = 0.045, respectively. Grade 3/4 toxicity was reported in 2 of 77 patients in the intravenous chemotherapy combined group, including nausea/vomiting 1.3% (1/77) and hypoleukemia 1.3% (1/77). CONCLUSION: Intravenous chemotherapy of gemcitabine and cisplatin combined with intravesical chemotherapy after TURBT can effectively reduce the postoperative recurrence rate, most toxicities were minor and reversible, and it may be considered as a new choice for HRNMIBC patients.

Multiple drug transporters contribute to the brain transfer of levofloxacin.

AIMS: The aim of this study was to assess the influence of the major transporters at blood-brain barrier and blood-cerebrospinal fluid barrier on levofloxacin (LVFX) pharmacokinetics in rat. To explore the different effects of transporters on drug concentrations in cerebrospinal fluid (CSF) and brain extracellular fluid (ECF). METHODS: High-performance liquid chromatography coupled with microdialysis was used to continuously and synchronously measure unbound concentrations of LVFX in rat blood, hippocampal ECF, and lateral ventricle CSF for comprehensive characterization of brain pharmacokinetics. The role of transporters in the brain efflux mechanism of LVFX was analyzed in the absence and presence of various transporter inhibitors. RESULTS: Following LVFX (50 mg/kg) administration, the unbound partition coefficient of LVFX in brain ECF and CSF (Kp,uu,ECF and Kp,uu,CSF ) were 34.0 ± 1.7% and 41.2 ± 2.4%, respectively. When probenecid was coadministered with LVFX, the AUC and the mean residence time (MRT) in rat blood increased significantly (p < 0.05). After MK571 intervention, 1.35-fold and 1.16-fold increases in Kp,uu,ECF and Kp,uu,CSF were observed, respectively (p < 0.05). Treatment with Ko143 increased the levels of LVFX in brain ECF. The difference in LVFX concentration in brain ECF and CSF was <3-fold with or without treatment with transporter inhibitors. CONCLUSION: Efflux of LVFX from the central nervous system (CNS) involves multidrug resistance-associated proteins (MRPs), breast cancer resistance protein (BCRP), and organic anion transporters (OATs). MRPs play an important role in mediating the brain/CSF-to-blood efflux of LVFX. LVFX concentrations in CSF can be used as a surrogate to predict the concentrations inside brain parenchyma.

LINC01535 Attenuates ccRCC Progression through Regulation of the miR-146b-5p/TRIM2 Axis and Inactivation of the PI3K/Akt Pathway.

lncRNAs, a group of eukaryotic cell genome-encoded transcripts, have been demonstrated to exert a notable impact on tumorigenesis. LINC01535, belonging to the lncRNA family, was reported to have an aberrant expression in certain types of cancers and thus affect cancer progression. Nevertheless, the expression pattern and potential roles of LINC01535 in clear cell renal cell carcinoma (ccRCC) remain to be elucidated. Here, LINC01535 expression was detected in ccRCC by RT-qPCR, cell proliferation by CCK-8 assays, and invasion by transwell assays. Besides, effects of LINC01535 on in vivo tumor growth were investigated by xenograft tumor models. The miR-146b-5p/LINC01535/TRIM2 interaction was evaluated via luciferase reporter assays. This study showed downregulation of LINC01535 in ccRCC. Moreover, LINC01535 upregulation attenuated in vitro ccRCC development and hindered in vivo tumor growth. Furthermore, LINC01535 sponged miR-146b-5p which had a negative correlation with LINC01535, and TRIM2 was a direct target of miR-146b-5p and mediated by LINC01535. Mechanically, LINC01535/miR-146b-5p/TRIM2 axis affected ccRCC progression by mediating the PI3K/Akt signaling. All in all, our observations suggest the LINC01535/miR-146b-5p/TRIM2 axis as a crucial role in ccRCC.

Acyclovir Brain Disposition: Interactions with P-gp, Bcrp, Mrp2, and Oat3 at the Blood-Brain Barrier.

BACKGROUND AND OBJECTIVE: Acyclovir is effective in treating herpes simplex virus infections of the central nervous system. The purpose of this study was to investigate the interactions between acyclovir and the efflux pumps P-glycoprotein (P-gp), breast cancer resistance protein (Bcrp), multidrug resistance protein 2 (Mrp2), and organic anion transporter 3 (Oat3) at the blood-brain barrier (BBB). METHODS: Acyclovir concentrations in the blood and brain were evaluated by microdialysis and high-performance liquid chromatography. Acyclovir pharmacokinetic parameters, including the area under the unbound blood concentration-time curve (AUCu,blood), the area under the unbound brain concentration-time curve (AUCu,brain), and the ratio of AUCu,brain to AUCu,blood (Kp.uu.brain), were evaluated in the presence and absence of elacridar (P-gp/Bcrp inhibitor, 7.5 mg/kg), tariquidar (P-gp/Bcrp inhibitor, 7.5 mg/kg), MK571 (Mrp2 inhibitor, 7.5 mg/kg), cyclosporine (P-gp/Bcrp/Mrp2 inhibitor, 25 mg/kg), and probenecid (Oat3 inhibitor, 50 mg/kg). RESULTS: The average AUCu,blood, AUCu,brain, and Kp.uu.brain in rats who received acyclovir (25 mg/kg, intravenous) alone were 1377.7 min · µg/ml, 435.4 min · µg/ml, and 31.6%, respectively. Probenecid drastically increased the AUCu,blood of acyclovir 1.73-fold, whereas coadministration with elacridar, tariquidar, MK571, and cyclosporine did not alter the blood pharmacokinetic parameters of acyclovir. Elacridar, tariquidar, MK571, cyclosporine, and probenecid significantly increased the AUCu,brain of acyclovir 1.51-, 1.54-, 1.47-, 1.95-, and 2.34-fold, respectively. Additionally, the Kp.uu.brain of acyclovir markedly increased 1.48-, 1.63-, 1.39-, 1.90-, and 1.35-fold following elacridar, tariquidar, MK571, cyclosporine, and probenecid administration, respectively. CONCLUSION: The present study demonstrated that P-gp, Bcrp, Mrp2, and Oat3 inhibition increased the penetration of acyclovir across the BBB, supporting the hypothesis that these efflux pumps restrict the distribution of acyclovir in the brain.

Malignancy in dermatomyositis: A retrospective paired case-control study of 202 patients from Central China.

Dermatomyositis (DM) is an idiopathic inflammatory myopathy that is closely related to malignant diseases. Our study aims to investigate the incidence and predictive factors for occurrence of malignancy among DM patients from Central China.We performed a retrospective, paired, case-control study of 736 DM patients admitted to the First Affiliated Hospital of Zhengzhou University between 2010 and 2017. We paired the 65 patients with malignancy with age-matched and sex-matched patients without malignancy in a ratio of 1:2. Two hundred two patients were finally enrolled and their clinical and laboratory data were collected.The incidence of malignancy in DM patients was 8.83% (65/736). Most malignancies were detected in the most recent 1 year before (9/65, 13.85%) or within 3 years after (40/65, 61.54%) the onset of DM. Males (35/65, 53.85%) and patients aged between 50 and 69 years (43/65, 66.15%) were prone to develop malignancies. Lung cancer (n = 11, 31.43%) was the most common malignancy in male patients, while for females, thyroid, breast and cervical cancer (n = 4 each, 13.33%) were more prevalent. Adenocarcinoma and squamous cell carcinoma (both 18/65, 27.69%) were the top two most common pathological types. Univariate analysis demonstrated that Gottron's sign (P = .02), dysphagia (P = .04), albumin (ALB) reduction (P = .003), aspartate aminotransferase (AST, P = .03), creatine kinase-MB (P = .02), absence of fever (P = .02), arthralgia (P = .04) and interstitial lung disease (ILD, P = .05) were closely related to the occurrence of malignancy. Multivariate analysis revealed the independent risk factors of ALB reduction (odds ratio = 1.546, P = .04) and the protective factor of ILD (odds ratio = 0.349, P = .003). There was no significant difference in the follow-up period between patients with and without ILD (P = .38).ALB reduction and the absence of ILD were the risk factors for malignancy in DM patients. The protective mechanism of ILD for DM patients needs further study.

Monitoring urinary metabolites resulting from sulfur mustard exposure in rabbits, using highly sensitive isotope-dilution gas chromatography-mass spectrometry.

A highly sensitive method for the determination of sulfur mustard (SM) metabolites thiodiglycol (TDG) and thiodiglycol sulfoxide (TDGO) in urine was established and validated using isotope-dilution negative-ion chemical ionization (NICI) gas chromatography-mass spectrometry (GC-MS). TDGO in the samples was reduced with TiCl3, and then determined together with TDG as a single analyte. The sample preparation procedures, including two solid-phase-extraction (SPE) clean-up steps, were optimized to improve the sensitivity of the method. The limits of detection (LOD) for both TDG and TDG plus TDGO (TDG + TDGO) were 0.1 ng mL(-1), and the limits of quantitation (LOQ) for both were 0.3 ng mL(-1). The method was used in a rabbit cutaneous SM exposure model. Domestic rabbits were exposed to neat liquid SM at three dosage levels (0.02, 0.05, and 0.15 LD50), and the urinary excretion of four species of hydrolysis metabolites, namely free TDG, free plus conjugated TDG (total TDG), free TDG + TDGO, and free plus conjugated TDG + TDGO (total TDG + TDGO), was evaluated to investigate the metabolic processes. The total urinary excretion profiles of the metabolites, including the peak time, time window, and dose-response and time-response relationships, were clarified. The results revealed that the concentrations of TDG and TDG + TDGO in the urine increased quickly and then decreased rapidly in the first two days after SM exposure. The cumulative amount of total TDG + TDGO excreted in urine during the first five days accounted for 0.5-1% of the applied dose of SM. It is also concluded that TDG and TDGO in urine existed mainly in free form, the levels of glucuronide and of sulfate conjugates of TDG or TDGO were very low, and most hydrolysis metabolites were present in the oxidized form (TDGO). The study indicates that the abnormal increase of TDG and TDGO excretion levels can be used as a diagnostic indicator and establishes a reference time-window for retrospective analysis and sampling after SM exposure.

Neuroprotective effects of madecassoside against focal cerebral ischemia reperfusion injury in rats.

Madecassoside, a triterpenoid derivative isolated from Centella asiatica, exhibits anti-inflammatory and antioxidant activities. We investigated its neuroprotective effect against ischemia-reperfusion (I/R) injury in cerebral neurons in male Sprague-Dawley rats. Madecassoside (6, 12, or 24mg/kg, i.v.) was administered 1h after the start of reperfusion, and neurological deficit score and infarct volume were evaluated 24h later. Neuronal apoptosis was assessed by performing terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL) staining, and pathological brain damage was estimated by performing hematoxylin and eosin staining. Serum levels of malondialdehyde, superoxide dismutase activity, reduced glutathione levels, and nitric oxide levels were also determined. mRNA and protein expression of pro-inflammatory cytokines (Interleukin-1ß/6, and tumor necrosis factor-α) were measured by real-time RT-PCR and ELISA, respectively; NF-κB p65 expression was determined by western blotting. Madecassoside significantly reduced brain infarct area, resolved neurological deficit, and ameliorated neuronal apoptosis. It also significantly reduced the levels of malondialdehyde and nitric oxide, and augmented the antioxidant activity in rats subjected to cerebral I/R. Moreover, the levels of pro-inflammatory cytokines and NF-κB p65 significantly reduced after madecassoside treatment. These results indicate that madecassoside is neuroprotective and may be useful in reducing the damage caused by stroke.

Gas chromatographic-tandem mass spectrometric analysis of ß-lyase metabolites of sulfur mustard adducts with glutathione in urine and its use in a rabbit cutaneous exposure model.

A method for quantitation of ß-lyase metabolites of sulfur mustard (SM) adducts with glutathione has been developed and validated using gas chromatography-tandem mass spectrometry (GC-MS/MS). The linear range of quantitation was 0.1-1000ng/mL in urine with a method detection limit of 0.02ng/mL. The method was applied in a rabbit exposure model. Domestic rabbits were cutaneously exposed to neat liquid SM in three dosage levels, and the ß-lyase metabolites in urine were determined as 1,1'-sulfonylbis[2-(methylthio)ethane] (SBMTE). The study showed that even though more than 99% of the total amount of ß-lyase metabolites was excreted in the first week after exposure, the ß-lyase metabolites of SM adducts with glutathione could be detected in urine from rabbits for up to 3 or 4 weeks after the SM cutaneous exposure. For high dosage group (15mg/kg, 0.15 LD50), the mean concentration of SBMTE detected was 0.32ng/mL on day 28. For middle (5mg/kg, 0.05 LD50) and low (2mg/kg, 0.02 LD50) dosage groups, the mean concentrations of SBMTE were 0.07ng/mL and 0.02ng/mL on day 21, respectively. The data from this study indicate that the method is sensitive and provides a relatively long time frame for the retrospective detection of SM exposure.

Improvements in monitoring the N-terminal valine adduct in human globin after exposure to sulfur mustard and synthesis of reference chemicals.

The N-terminal valine adduct (HETE-Val) in globin is believed to behave as a long-lived biomarker after exposure to sulfur mustard (HD). Development of a highly sensitive method for monitoring HETE-Val, particularly at low HD exposure levels or for retrospective detection, would be a significant achievement. In this study, by improving the sample preparation method, a sensitive NCI-GC/MS method was established for the analysis of HETE-Val in globin after HD exposure. To optimize and investigate the sample preparation method, all the relevant HETE-Val chemicals were synthesized, purified, and characterized. By carrying out optimized solid phase extraction (SPE) cleanup followed by modified Edman degradation results in a low detection level and clean baseline. The minimum detectable exposure level of human blood (in vitro) to HD is 20 nmol/L (S/N>3). The interday and intraday precisions of the proposed method were found to be acceptable with less than a 15% relative standard deviation (RSD). A nearly linear dose-effect relationship was observed between HETE-Val and a HD exposure concentration range of 0.1-120 µmol/L. The percentage of HD that reacted with N-terminal valine in globin obtained from human blood (in vitro) was quantified using the proposed method.

[Predictive value of human fatty acid binding protein for myocardial ischemia and injury in perioperative period of cardiac surgery].

OBJECTIVE: To evaluate the value of human fatty acid binding protein (h-FABP) in predicting myocardial ischemia and injury in the perioperative period of cardiac surgery, we observed the dynamic changes of h-FABP in perioperative period of patients underwent coronary artery bypass grafting and ventricular septal defects repairing surgery, and evaluated the relationship of h-FABP and ischemia modified albumin (IMA), CK-MB, cTnI. METHODS: Patients underwent coronary artery bypass grafting (n=30) and ventricular septal defect repairing (n=30) surgery between February 2008 and December 2008 were included in this study. Venous blood sample was obtained at preoperative, aortic clamping, aortic unclamping of 10 min, 2 h, 6 h, 12 h, 24 h for the measurements of h-FABP, IMA, cTnI and CK-MB. RESULTS: h-FABP and IMA changed in the same way at various examined time points, h-FABP changes also paralleled cTnI and CK-MB changes, h-FABP peaked early during myocardial ischemia and injury and returned to baseline level at 2 h post myocardial ischemia and injury. Linear correlation analysis showed that the peak value of h-FABP was positively correlated with IMA, CK-MB and cTnI in both CABG group (r = 0.948, 0.964 and 0.961, P < 0.05) and in the VSD group (r = 0.986, 0.978 and 0.957). CONCLUSIONS: h-FABP is an early diagnostic parameter reflecting perioperative myocardial ischemia and injury in cardiac surgery. Quantitative h-FABP monitoring could predict the severity of myocardial ischemia and injury early during cardiac surgery.