Pharmacokinetics of Edaravone Oral Suspension in Patients With Amyotrophic Lateral Sclerosis

PURPOSE

Edaravone is a neuroprotective agent approved as an intravenous treatment for amyotrophic lateral sclerosis (ALS). The intravenous administration of edaravone places a burden on patients and there is a clinical need for oral agents for the treatment of ALS. This report aimed to assess the pharmacokinetics and safety of an edaravone oral suspension in patients with ALS after oral and percutaneous endoscopic gastrostomy (PEG) tube administration.

METHODS

Two single-dose, open-label phase 1 clinical studies were conducted. Edaravone oral suspension (105 mg of edaravone in 5 mL aqueous suspension) was administered orally and via PEG tube to 9 and 6 Japanese patients with ALS, respectively. Plasma and urinary pharmacokinetics of unchanged edaravone and its metabolites (sulfate and glucuronide conjugates) were determined. Safety was also evaluated.

FINDINGS

After reaching maximum plasma concentration, the mean plasma concentration-time of unchanged edaravone showed a triphasic elimination. Mean plasma concentration-time profiles of the metabolites were higher than those of unchanged edaravone. The mean urinary excretion ratios were higher for the glucuronide conjugate than for either unchanged edaravone or the sulfate conjugate. In patients administered edaravone orally, a single adverse event occurred (blood urine present), which was mild and improved without medical intervention. No adverse drug reactions or serious adverse events were reported. In patients administered edaravone via PEG tube, 5 treatment-emergent adverse events were reported in 3 patients; none were related to the study drug. No adverse drug reactions were reported.

IMPLICATIONS

In patients with ALS, a single dose of edaravone oral suspension was well absorbed and mainly eliminated in urine as the glucuronide conjugate. No safety concerns emerged. Pharmacokinetics were similar to those previously reported in healthy participants following oral administration. This indicates that effective drug concentrations were achieved and edaravone can be successfully administered both orally and via a PEG tube in patients with ALS.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT04176224 (oral administration) and NCT04254913 (PEG tube administration), www.

CLINICALTRIALS

gov.

Food Effect Study to Assess the Impact on Edaravone Pharmacokinetic Profiles in Healthy Participants

PURPOSE

The safety and efficacy of intravenous edaravone, a neuroprotectant used for the treatment of amyotrophic lateral sclerosis (ALS), have been shown in clinical trials. An oral suspension of edaravone has been developed, but the food effect on its pharmacokinetic profile has not been evaluated. This study aimed to assess the food effect on the pharmacokinetic profile of edaravone after oral administration and to investigate dosing regimens and administration instructions with different meal intake and timing.

METHODS

Data from 3 Phase I clinical studies were used to evaluate the effect of food on the pharmacokinetic profiles of a single dose of edaravone oral suspension. In all 3 studies, participants received a single dose of edaravone with various meal conditions. Healthy Japanese adult male participants (Studies 1, 2, and 3) or female participants (Study 3) aged 20 to 45 years at the time of informed consent were included.

FINDINGS

In Study 1, 6 participants were enrolled and 5 completed the study. Nine and 16 participants were treated in Studies 2 and 3, respectively, and all completed the study. The C_max and AUC_0-∞ of edaravone were lower when administered 30 minutes after a high-fat meal compared with those in a fasted condition (Study 1). Lower plasma edaravone concentrations (approximately within the first hour) and subsequent lower C_max and AUC_0-∞ were observed after administration of edaravone 4 hours after a high-fat meal (Study 2) or 2 hours after a low-fat meal (Study 3). The C_max and AUC_0-∞ of oral edaravone were generally similar and not affected when administered 8 hours after a high-fat meal, 4 hours after a low-fat meal, or 2 hours after a light meal relative to the fasted condition. Administration of edaravone 1 hour before a high-fat meal resulted in no effect on C_max or AUC_0-∞ relative to the fasted condition. Administration of edaravone in the fed or fasted conditions resulted in a similar urine pharmacokinetic profile.

IMPLICATIONS

Oral administration of edaravone with a meal decreased the plasma concentration of edaravone. Oral administration of edaravone 8 hours after a high-fat meal, 4 hours after a low-fat meal, 2 hours after a light meal, and 1 hour before a high-fat meal showed no effect of food on the PK profile of unchanged edaravone compared with that observed under a fasted condition.

CLINICALTRIALS

gov identifiers: NCT04481750, NCT04481789, and NCT05342597.

Evaluation of Pharmacokinetics, Safety, and Drug-Drug Interactions of an Oral Suspension of Edaravone in Healthy Adults

Intravenous (IV) edaravone is approved as an amyotrophic lateral sclerosis (ALS) treatment. Because IV administration places a burden on patients, development of orally administered ALS treatments is needed. Therefore, 2 phase 1 studies of oral formulations of edaravone in healthy subjects examined the pharmacokinetics (PK), safety, racial differences, and drug‐drug interactions (DDIs) and investigated the dose of the oral formulation considered to be bioequivalent to the approved dose of the IV formulation. Study 1 was a placebo‐controlled, randomized, single‐blind study of single‐ascending‐dose oral edaravone with the dose range of 30 to 300 mg (n = 56). Study 2 was conducted in 2 cohorts (n = 84); the first assessed DDIs with multiple‐dose edaravone 120 mg/day given over 5 or 8 days (coadministered with single‐dose rosuvastatin, sildenafil, or furosemide), and the second evaluated PK and racial (Japanese/White) differences in PK parameters with doses of 100‐mg edaravone. The oral formulation of edaravone was well absorbed, and plasma concentrations of unchanged edaravone increased more than dose proportionally within the dose range of 30 to 300 mg. No effect of race on oral edaravone PK and no notable DDI effects possibly caused by orally administered edaravone were observed. The oral edaravone formulations were safe and tolerable under the assessed conditions. Mathematical modeling determined that equivalent exposures in plasma with the approved dose of the IV edaravone formulation, as reported previously, could be achieved when the oral edaravone formulation was administered at a dose of  ≈100 mg, with an absolute bioavailability of ≈60%.

An Open-label, Single-dose Study to Evaluate the Pharmacokinetic Variables of Edaravone in Subjects with Mild, Moderate, or No Renal Impairment

PURPOSE

The goal of this study was to compare edaravone pharmacokinetic (PK) variables and tolerability after a single intravenous (IV) infusion of 30 mg over 60 min in subjects with mild renal impairment (estimated glomerular filtration rate 60-89 mL/min/1.73 m²), moderate renal impairment (30-59 mL/min/1.73 m²), or normal renal function (≥90 mL/min/1.73 m²).

METHODS

This open-label, single-dose study was conducted in Japan. After a screening period of up to 3 weeks, all subjects received a single IV dose of edaravone 30 mg/h on day 1. Blood samples were collected for PK analysis of edaravone and its sulfate conjugate for up to 48 h postdose.

FINDINGS

Edaravone was administered to 30 subjects: 11 with mild (Group 1), 8 with moderate (Group 2), and 11 with no (Group 3) renal impairment. Although geometric least-squares mean values for C_max and AUC_0-∞ for unchanged edaravone were 1.15- and 1.20-fold greater in Group 1 than in Group 3, and were 1.25- and 1.30-fold greater in Group 2 than in Group 3, no statistically significant differences in exposure (C_max and AUC) to edaravone were noted between the 3 groups (P > 0.05). The geometric least-squares mean values for C_max and AUC_0-∞ for the sulfate conjugate were 1.41- and 1.50-fold greater in Group 1 than in Group 3, and 1.41- and 1.97-fold greater in Group 2 than in Group 3. Differences in exposure (C_max and AUC) to the sulfate conjugate of edaravone were statistically significant between the 3 study groups (P < 0.0001). A total of 5 treatment-emergent adverse events in 3 subjects in Group 1 were considered by the investigator to be reasonably related to edaravone: headache (2 events/2 subjects), vomiting (2 events/1 subjects), and increased blood bilirubin level (n = 1). These treatment-emergent adverse events were mild and recovered without sequelae.

IMPLICATIONS

Mild to moderate renal impairment had no clinically significant effects on the PK profile of edaravone in Japanese subjects, relative to individuals with normal renal function, and there were no significant safety concerns. Thus, edaravone dosage adjustments are unlikely to be needed in patients with mild to moderate renal impairment. Clinicaltrials.gov identifier: NCT03289208.

Open-label, Single-dose Studies of the Pharmacokinetics of Edaravone in Subjects with Mild, Moderate, or Severe Hepatic Impairment Compared to Subjects with Normal Hepatic Functioning

PURPOSE

Two studies were conducted to assess the pharmacokinetic (PK) properties and tolerability of edaravone in Japanese subjects with mild to moderate hepatic impairment or normal hepatic functioning (study 1), and in white subjects with severe hepatic impairment compared to subjects with normal hepatic functioning (study 2).

METHODS

Studies 1 and 2 were multicenter, open-label, single-dose studies that included subjects aged 18-75 years. In study 1, subjects were stratified into 3 different groups of hepatic functioning according to Child-Pugh score: mild hepatic impairment, score 5 or 6 (n = 8); moderate hepatic impairment, score 7-9 (n = 6); or normal hepatic functioning (n = 8). In study 2, subjects had severe hepatic impairment (Child-Pugh score 10-14; n = 6) or normal hepatic functioning (n = 6). In both studies, all subjects were given edaravone 30 mg IV infused over 60 min on the morning of day 1. Blood samples for use in PK analyses were collected from days 1-3. The PK properties (C_max, AUC_0-last, and AUC_0-∞) of edaravone and its sulfate conjugate metabolite were measured.

FINDINGS

In study 1, the geometric least-squares mean (GLSM) C_max and AUC_0-∞ of unchanged edaravone were 1.203- and 1.065-fold greater, respectively, in subjects with mild hepatic impairment versus normal hepatic functioning, and were 1.235- and 1.142-fold greater, respectively, in subjects with moderate hepatic impairment versus normal hepatic functioning. In study 2, GLSM C_max and AUC_0-∞ of unchanged edaravone were 1.203- and 1.190-fold greater, respectively, in subjects with severe hepatic impairment versus normal hepatic functioning. In both studies the AUC_0-last, AUC_0-∞, unbound AUC from time zero to infinity, and C_max of unchanged edaravone were increased slightly with increases in Child-Pugh classification. No adverse events considered related to edaravone were reported, except for 1 case of sinus bradycardia in a subject with normal hepatic functioning in study 2. The event was moderate in severity, considered as possibly related to edaravone, and resolved during the study.

IMPLICATIONS

Mild to moderate and severe hepatic impairment had no apparent clinically significant effects on the PK profile of edaravone in Japanese and white subjects, respectively, relative to individuals with normal hepatic functioning, and there were no notable tolerability concerns. Thus, edaravone dosage adjustments are unlikely to be needed in edaravone-treated patients with mild to moderate and severe hepatic impairment. ClinicalTrials.gov identifiers: NCT03289234 (mild to moderate hepatic impairment) and NCT03664544 (severe hepatic impairment).

A Randomized, Single-Blind, Placebo-Controlled, 3-Way Crossover Study to Evaluate the Effect of Therapeutic and Supratherapeutic Doses of Edaravone on QT/QTc Interval in Healthy Subjects

This randomized, single-blind, 3-way crossover study assessed the effect of edaravone on QT interval, including an exposure-response analysis. Twenty-seven healthy Japanese male volunteers, aged 20 to 49 years, were randomly assigned to receive a single intravenous dose of each treatment in 1 of 3 sequences (n = 9 each): ACB, BAC, and CBA, where A was edaravone 60 mg (therapeutic dose), B was edaravone 300 mg (supratherapeutic dose), and C was normal saline (placebo). Electrocardiographs were collected to assess treatment effects. In an exposure-response analysis, a linear model was determined to be valid and indicated no statistically significant positive slope for the relationship between change from baseline in QTcF (ΔQTcF) and edaravone concentration (0.000155 ms/(ng/mL); P = .1478); upper bounds of 2-sided 90% confidence intervals after placebo adjustment (ΔΔQTcF) were <10 milliseconds at the geometric mean maximum concentration for each edaravone dose. Overall estimated values by time point of ΔΔQTcF ≤0.9 milliseconds, no outlier values, and no morphologic changes suggestive of repolarization abnormalities were observed. Analysis of heart rate, PR interval, and QRS duration also revealed no adverse findings. These data indicate that edaravone, even at supratherapeutic doses, does not produce clinically meaningful QT prolongation and has no clinically relevant cardiac effects.

Allosteric pluripotency as revealed by protein kinase A

The functional response of a signaling system to an allosteric stimulus often depends on subcellular conditions, a phenomenon known as pluripotent allostery. For example, a single allosteric modulator, Rp-cAMPS, of the prototypical protein kinase A (PKA) switches from antagonist to agonist depending on MgATP levels. However, the mechanism underlying such pluripotent allostery has remained elusive for decades. Using nuclear magnetic resonance spectroscopy, ensemble models, kinase assays, and molecular dynamics simulations, we show that allosteric pluripotency arises from surprisingly divergent responses of highly homologous tandem domains. The differential responses perturb domain-domain interactions and remodel the free-energy landscape of inhibitory excited states sampled by the regulatory subunit of PKA. The resulting activation threshold values are comparable to the effective free energy of regulatory and catalytic subunit binding, which depends on metabolites, substrates, and mutations, explaining pluripotent allostery and warranting a general redefinition of allosteric targets to include specific subcellular environments.

Interleukin-33 enhances programmed oncosis of ST2L-positive low-metastatic cells in the tumour microenvironment of lung cancer

The proinflammatory interleukin-33 (IL-33) binds to its receptor ST2L on the surface of immune cells and stimulates the production of Th2 cytokines; however, the effects of IL-33 on tumour cells are poorly understood. Here we show that ST2 was significantly downregulated in human lung cancer tissues and cells compared with normal lung tissues and cells. IL-33 expression was also inversely correlated with the stages of human lung cancers. In accordance with this finding, low-metastatic cells but not high-metastatic cells derived from Lewis lung carcinoma expressed functional ST2L. IL-33 was abundantly present in the tumours established by the low-metastatic cells compared with those formed by the high-metastatic cells. Although the low-metastatic cells scarcely expressed IL-33 in vitro, these cells did expry 6ess this molecule in vivo, likely due to stimulation by intratumoural IL-1β and IL-33. Importantly, IL-33 enhanced the cell death of ST2L-positive low-metastatic cells, but not of ST2L-negative high-metastatic cells, under glucose-depleted, glutamine-depleted and hypoxic conditions through p38 MAPK and mTOR activation, and in a mitochondria-dependent manner. The cell death was characterised by cytoplasmic blisters and karyolysis, which are unique morphological features of oncosis. Inevitably, the low-metastatic cells, but not of the high-metastatic cells, grew faster in IL-33(-/-) mice than in wild-type mice. Furthermore, IL-33 selected for the ST2L-positive, oncosis-resistant high-metastatic cells under conditions mimicking the tumour microenvironment. These data suggest that IL-33 enhances lung cancer progression by selecting for more malignant cells in the tumour microenvironment.

Confirmatory double-blind, parallel-group, placebo-controlled study of efficacy and safety of edaravone (MCI-186) in amyotrophic lateral sclerosis patients

Our objective was to confirm the efficacy and safety of edaravone in amyotrophic lateral sclerosis (ALS) patients. We conducted a 36-week confirmatory study, consisting of 12-week pre-observation period followed by 24-week treatment period. Patients received placebo or edaravone i.v. infusion over 60 min for the first 14 days in cycle 1, and for 10 of the first 14 days during cycles 2 to 6. The efficacy primary endpoint was changed in the revised ALS functional rating scale (ALSFRS-R) scores during the 24-week treatment. Patients were treated with placebo (n = 104) and edaravone (n = 102). Changes in ALSFRS-R during the 24-week treatment were -6.35 ± 0.84 in the placebo group (n = 99) and -5.70 ± 0.85 in the edaravone group (n = 100), with a difference of 0.65 ± 0.78 (p = 0.411). Adverse events amounted to 88.5% (92/104) in the placebo group and 89.2% (91/102) in the edaravone group. In conclusion, the reduction of ALSFRS-R was smaller in the edaravone group than in the placebo group, but efficacy of edaravone for treatment of ALS was not demonstrated. Levels and frequencies of reported adverse events were similar in the two groups.

PD-1/PD-L1 expression in human T-cell leukemia virus type 1 carriers and adult T-cell leukemia/lymphoma patients

Adult T-cell leukemia/lymphoma (ATLL) develops after infection with human T-cell leukemia virus-1 (HTLV-1) after a long latency period. The negative regulatory programmed death-1/programmed death-1 ligand 1 (PD-1/PD-L1) pathway has been implicated in the induction of cytotoxic T-lymphocyte (CTL) exhaustion during chronic viral infection along with tumor escape from host immunity. To determine whether the PD-1/PD-L1 pathway could be involved in the establishment of persistent HTLV-1 infections and immune evasion of ATLL cells in patients, we examined PD-1/PD-L1 expression on cells from 27 asymptomatic HTLV-1 carriers (ACs) and 27 ATLL patients in comparison with cells from 18 healthy donors. PD-1 expression on HTLV-1-specific CTLs from ACs and ATLL patients was dramatically elevated. In addition, PD-1 expression was significantly higher on CD8+ T cells along with cytomegalovirus (CMV)- and Epstein-Barr virus (EBV)-specific CTLs in ATLL patients compared with ACs and control individuals. Primary ATLL cells in 21.7% of ATLL patients expressed PD-L1, whereas elevated expression was not observed in cells from ACs. Finally, in functional studies, we observed that an anti-PD-L1 antagonistic antibody upregulated HTLV-1-specific CD8+T-cell response. These observations suggest that the PD-1/PD-L1 pathway plays a role in fostering persistent HTLV-1 infections, which may further ATLL development and facilitate immune evasion by ATLL cells.

Outcomes of 23- and 25-gauge transconjunctival sutureless vitrectomies for idiopathic macular holes

BACKGROUND/AIMS

To assess the outcomes of 23-gauge sutureless transconjunctival vitrectomies (TSV), as compared with 25-gauge TSV in macular hole surgeries.

METHODS

A retrospective, consecutive, interventional case series of 47 eyes with idiopathic macular holes treated by 23- or 25-gauge TSV were analysed.

RESULTS

The operative time was 37.2 (SD 8.9) min with 23-gauge TSV and 34.2 (8.7) min with 25-gauge TSV (p = 0.388). The anatomical success rate was 96% with 23-gauge TSV and 92% with 25-gauge TSV (p>0.999). The logarithm of the minimum angle of resolution of best-corrected visual acuity (BCVA) at the sixth postoperative month was 0.19 (0.16) with 23-gauge TSV and 0.19 (0.25) with 25-gauge TSV (p = 0.521). Postoperative improvement in BCVA was comparable between the two TSVs. IOP on postoperative day 1 was lower with 25-gauge TSV (12.3 (4.9) mm Hg) than with 23-gauge TSV (17.4 (5.8) mm Hg) (p = 0.036). Complications included retinal break, intraoperative bleeding and slippage of the infusion cannula with 23-gauge TSV, while retinal detachment and postoperative hypotony occurred in the 25-gauge TSV group (p = 0.570).

CONCLUSION

23-gauge TSV appears to be as safe and effective as 25-gauge TSV in macular hole surgery.

Identifying pathogenic genetic background of simplex or multiplex retinitis pigmentosa patients: a large scale mutation screening study

BACKGROUND AND PURPOSE

More than half of the retinitis pigmentosa (RP) cases are genetically simplex or multiplex. To date, 37 causative genes of RP have been identified; however, the elucidation of gene defects in simplex or multiplex RP patients/families remains problematic. The aim of our study was to identify the genetic causes of RP in patients with unknown or non-Mendelian inheritance.

METHODS AND RESULTS

Since 2003, 52 simplex RP patients, 151 patients from 141 multiplex RP families, and six sporadic patients with retinal degeneration were studied. A total of 108 exons of 30 RP-causing genes that harboured the reported mutations were screened by an efficient denaturing high performance liquid chromatography (dHPLC) based assay. Aberrant fragments were subsequently analysed by automatic sequencing. Twenty-six mutations, including two frameshift mutations, one single amino acid deletion, and 23 missense mutations, were identified in 28 probands (14.07%). Eighteen mutations have not been reported to date. Three pairs of combined mutations in different genes were identified in two sporadic cases and one multiplex family, indicating the possibility of novel digenic patterns. Of the 23 missense mutations, 21 were predicted as deleterious mutations by computational methods using PolyPhen, SIFT, PANTHER, and PMut programs.

CONCLUSION

We elucidated the mutation spectrum in Japanese RP patients and demonstrated the validity of the mutation detection system using dHPLC sequencing for genetic diagnosis in RP patients independent of familial incidence, which may provide a model strategy for identifying genetic causes in other diseases linked to a wide range of genes.

Retinal repair by transplantation of photoreceptor precursors

Photoreceptor loss causes irreversible blindness in many retinal diseases. Repair of such damage by cell transplantation is one of the most feasible types of central nervous system repair; photoreceptor degeneration initially leaves the inner retinal circuitry intact and new photoreceptors need only make single, short synaptic connections to contribute to the retinotopic map. So far, brain- and retina-derived stem cells transplanted into adult retina have shown little evidence of being able to integrate into the outer nuclear layer and differentiate into new photoreceptors. Furthermore, there has been no demonstration that transplanted cells form functional synaptic connections with other neurons in the recipient retina or restore visual function. This might be because the mature mammalian retina lacks the ability to accept and incorporate stem cells or to promote photoreceptor differentiation. We hypothesized that committed progenitor or precursor cells at later ontogenetic stages might have a higher probability of success upon transplantation. Here we show that donor cells can integrate into the adult or degenerating retina if they are taken from the developing retina at a time coincident with the peak of rod genesis. These transplanted cells integrate, differentiate into rod photoreceptors, form synaptic connections and improve visual function. Furthermore, we use genetically tagged post-mitotic rod precursors expressing the transcription factor Nrl (ref. 6) (neural retina leucine zipper) to show that successfully integrated rod photoreceptors are derived only from immature post-mitotic rod precursors and not from proliferating progenitor or stem cells. These findings define the ontogenetic stage of donor cells for successful rod photoreceptor transplantation.

Cyclooxygenase-2 expression and relationship to tumour progression in human renal cell carcinoma

AIMS

Cyclooxygenase (COX), which catalyses the synthesis of prostaglandins from arachidonic acid, has two isoforms; COX-1 and COX-2. There is ample evidence to suggest an important role for COX-2 in cancer. The aim of this study was to evaluate the clinical significance of COX-2 expression and its localization in the development and progression of human renal cell carcinoma (RCC).

METHODS AND RESULTS

The expression and localization of COX-2 were evaluated in human RCC tissues from 75 patients by immunohistochemistry. Immunoreactive COX-2 protein was observed in all cases of RCC, and the levels of COX-2 expression were correlated with tumour grade and pathological stage. Expression of COX-2 was higher in the granular cell subtype than in the clear cell subtype of RCC. Immunoelectron microscopy revealed that COX-2 was expressed in the nuclear membrane, rough endoplasmic reticulum, Golgi complex and mitochondrial membrane of RCC cells.

CONCLUSION

COX-2 overexpression within these intracellular organelles in RCC may be associated with renal cell carcinogenesis and COX-2 may be a useful biomarker in RCC.

Hepatocyte growth factor as an enhancer of nmda currents and synaptic plasticity in the hippocampus

Hepatocyte growth factor (HGF) promotes the survival and migration of immature neurons, but its role in the mature brain has remained elusive. In the hippocampus of juvenile rats, we found that the HGF receptor c-Met was expressed in neurons. Furthermore, it was highly Tyr-phosphorylated, more so than in the liver under normal conditions, suggesting that the receptor is activated and that HGF may act continuously in the intact brain. Exogenously applied HGF enhanced synaptic long-term potentiation (LTP) in the CA1 region of hippocampus, but did not affect long-term depression. We further found that HGF augmented N-methyl-D-aspartate receptor-mediated currents in both slices and dissociated neurons. This augmentation is likely to underlie the enhancement of LTP. Considering that the expression of both HGF and c-Met are known to be induced by ischemic stimuli, this modulation would provide a novel understanding of a neuronal regulatory systems shared with pathogenic ischemic states.

S-oxidation of S-methyl-esonarimod by flavin-containing monooxygenases in human liver microsomes

1. Studies using human liver microsomes and recombinant human cytochrome P450 (CYP) and flavin-containing monooxygenase (FMO) were performed to identify the enzymes responsible for the metabolism of S-methyl-esonarimod (M2), an active metabolite of esonarimod (KE-298, a novel antirheumatic drug). 2. S-oxidative activities of M2 significantly correlated with those of methyl p-tolyl sulfide, a specific substrate of FMOs, as tested using 10 different human liver microsomes (r(2) = 0.539, p<0.05). Thermal treatment of microsomes reduced the S-oxidative activity in the absence of the NADPH-generating system at 45 degrees C for 5 min. However, methimazole, a known competitive substrate of FMOs, was a weak inhibitor of the S-oxidation in liver microsomes. 3. Recombinant human FMO1 and FMO5 produced M3 in greater quantities than recombinant human FMO3. The S-oxidation of M2 by recombinant human FMO5 was not appreciably inhibited in the presence of methimazole. In contrast, methimazole was effective in suppressing the catalytic activity of recombinant human FMO1 and FMO3. 4. The apparent K(m) (K(m app)) for the S-oxidation of M2 in human recombinant FMO5 (2.71 microM) was similar to that obtained using human liver microsomes (2.43 microM). 5. The present results suggest that the S-oxidation of S-methyl esonarimod reflects FMO5 activity in the human liver because the recombinant FMO5 data match well with the human liver microsomal experiments.

New morphological changes induced by FK506 in a short period in the rat kidney and the effect of superoxide dismutase and OKY-046 on THEM: the relationship of FK506 nephrotoxicity to lipid peroxidation and change in production of thromboxane A2 in the kidney

Juxtaglomerular (JG) hyperplasia and tubular damage along with a decrease in the urine creatinine level induced by FK506 in rat kidney have already been reported in previous paper by us. In this paper, we document the relationship of FK506 nephrotoxicity to the change in the production of thromboxane (Tx) A2 and the lipid peroxidation of the cellular membrane in the rat kidney in order to clarify its morphogenesis. The urinary excretion of TxB2 increased with FK506 administration even on day 1 (P < 0.02). Histologically, OKY-046 (thromboxane synthetase inhibitor) decreased tubular damage, although JG hyperplasia was not eradicated, while biochemically the excretion of TxB2 decreased significantly (P < 0.02), and both the decrease in the urine creatinine level and the increase in the N-acetyl-beta,D-glucosaminidase (NAG) index were relatively smaller. Although the FK506-induced morphological and biochemical changes could not be prevented by the continuous administration of superoxide dismutase (SOD) 30,000 U/kg daily, the malondialdehyde content in renal tissue removed 1 h after FK506 administration had increased. These data suggest that FK506 nephrotoxicity is related to the change in the production of TxA2 and lipid peroxidation of the cellular membrane. However, other mechanisms such as the involvement of sympathomimetic effects of FK506 and other vasoconstrictive factors cannot be ruled out.

Comparison of stepwise and simultaneous estimations of population pharmacokinetics and pharmacodynamics of TS-943

The prediction performances of population pharmacokinetic-pharmacodynamic analysis of the two methods (a stepwise and a simultaneous estimations) were evaluated with respect to their accuracies and precisions. A study was designed to investigate the safety and efficacy of TS-943 by a 4 hours constant infusion in 36 healthy male subjects. Population analysis was performed using pharmacokinetic and pharmacodynamic models with NONMEM. The mean of the prediction error (MPE) and the root mean squared error (RMSE) served as a measure of accuracy and precision. In addition, a bootstrap validation was also performed. The results indicate that those population pharmacokinetic-pharmacodynamic parameters for the two methods were comparable. The results of simultaneous estimations are similar to those obtained using a stepwise estimation. The mean parameter estimates obtained with the additional 200 bootstrap replicates of data were within 15% of those obtained with the final model in both methods. The present results demonstrated that the accuracy of pharmacodynamic evaluations using a stepwise end a simultaneous estimations was comparable.

Electromyography of male rat perineal musculature during copulatory behavior

Electromyogram (EMG) recordings were made from the bulbospongiosus (BS) and ischiocavernosus (IC) muscles of the awake male rat in order to evaluate the roles played by these muscles in the implementation of penile intromission during a copulatory encounter. Male rats with bipolar wire electrodes implanted chronically in the BS and IC muscles were mated with sexually receptive females. Concurrent videotape recordings established a relationship between EMG and components of male rat copulatory behavior, i.e. mount, intromission and ejaculation. On EMGs recorded from the IC muscle, the initial low-amplitude phase at the initiation of each behavioral component was distinguished from the late high-amplitude phase whenever the male accomplished mounting or intromission. In the BS muscle, the late high-amplitude phase was observed only when the male accomplished intromission. Power spectrum analysis by fast Fourier transformation revealed that in the IC muscle the two phases differed at an overall range of 100-1,000 Hz. In the BS muscle, however, the spectra of the two phases differed at a specific range of 400-600 Hz. Recruitment of additional motor units would culminate in such a characteristic rise in the power spectrum. The results suggest that somatosensory inputs contingent on the intromission cause such recruitment in the BS to regulate penile cups and other movements.

Pharmacokinetic and pharmacodynamic analysis of TS-943, a selective non-peptide platelet glycoprotein-IIb/IIIa (GPIIb/IIIa) receptor antagonist, using a nonlinear mixed effect model in dogs

A simultaneous analysis of the pharmacokinetics and pharmacodynamics of TS-943, a selective nonpeptide platelet glycoprotein-IIb/IIIa (GPIIb/IIIa) receptor antagonist, was made in dogs using a nonlinear mixed effect model. Plasma concentrations of TS-943 were determined after bolus intravenous injection, constant infusion and bolus plus constant infusion. Pharmacokinetic/pharmacodynamic data were fitted using NONMEM software. The pharmacokinetics of TS-943 fitted a two-compartment open model with first-order elimination. The pharmacodynamic model that best fitted platelet aggregation was an inhibitory sigmoid Emax model. The final estimates for E0 (baseline effect), Emax (maximum effect), IC50 (50% inhibitory concentration) and gamma (Hill coefficient) were 66.3%, 64.3%, 104 ng mL(-1) and 1.37, respectively. Correlations between TS-943 plasma concentration and extension of template bleeding time were examined by fitting with an exponential model. The TS-943 plasma concentration necessary to double bleeding time (C2-BTE) was approximately 209 ng mL(-1). The model estimated that the C2-BTE/IC50 (inhibition of platelet aggregation) ratio was approximately 2.0-fold in dogs. Our results suggest that the ratio values for dogs and man are comparable. A nonlinear mixed effect model was a useful tool for exploring the concentration-effect relationship for both efficacy and safety of TS-943 in dogs and man. In this study, the dog was found to be a useful model for screening of efficacy and safety of TS-943 in man.

A new delivery system for 5-fluorouracil using prodrug and converting enzyme

AIMS

To evaluate a new delivery system of 5-fluorouracil (5-FU) using 5-fluorocytosine (5-FC) as a prodrug and cytosine deaminase induced in vitro and in vivo.

METHODS

Fibroblastic cells from rabbit Tenon's capsule were cultured. The cells were exposed to 5-FU and 5-FC with or without cytosine deaminase induced by recombinant adenovirus. In the in vitro study, cell proliferation and DNA synthesis were assessed by MTS, BrdU assay. The effect of 5-FC removal after the treatment of 5-FC and cytosine deaminase induction was also assayed. In the in vivo study cells with or without cytosine deaminase induction were transplanted into the subconjunctival space of mice, followed by eye drops of 1000 microg/ml of 5-FC three times a day. The mice were sacrificed at days 1, 5, and 10, then the cells transplanted were evaluated.

RESULTS

Cell proliferation was inhibited by exposure to 5-FU in a dose dependent manner; however, up to 1000 microg/ml of 5-FC did not affect cell proliferation. Cell proliferation was inhibited by exposure to 5-FC in a time dependent manner with induction of cytosine deaminase following infection of recombinant adenovirus. When 5-FC was removed 3 or 6 days after the treatment, the cells grew again. The effect was reproduced in the in vivo model of subconjunctival cellular proliferation although 5-FC was administrated as eye drops. There were no cases with corneal erosion.

CONCLUSION

Cell proliferation was inhibited by co-exposure of 5-FC and cytosine deaminase. This new delivery system may merit controlled delivery of 5-FU after filtering surgery.

Impaired blood rheology by remnant-like lipoprotein particles: studies in patients with fatty liver disease

Fatty liver disease (FLD) characterised by a high plasma levels of lipoproteins and remnant-like lipoproteins (RLP) is a risk factor for impaired microvascular blood flow, endothelial cell dysfunction and atherosclerosis. Using an immunoseparation technique with a gel mixture containing human monoclonal antibodies to apo A-I and apo B-100, we separated and measured RLP cholesterol (RLP-C) levels which reflect RLP in patients with FLD (n=20). Whole blood transit time (TT) was determined by a microchannel method (MC-FAN) which allows blood flow to be viewed via a microscope connected to an image display unit. RLP-C levels were higher (P<0.01) in FLD, 15.6 +/- 1.0 mg/dl compared with 4.8 +/- 0.5 mg/dl for controls (n=20). Similarly, TT was longer (P<0.01) in FLD, 284.5 +/- 26.1 sec/100 microl compared with 82.8 +/- 1.0 sec/100 microl for controls. Since the liver is a major site for RLP formation and degradation, it is affected to a greater extent in patients with FLD. It is likely that high levels of RLP can impair microvascular perfusion in the liver tissue and contribute to the development and progression of FLD.

Definition of a 1-Mb homozygous deletion at 9q32-q33 in a human bladder-cancer cell line

We performed detailed molecular analyses of a suspected homozygous deletion on chromosome 9q32-q33 in a bladder-cancer cell line (KYBTDS) derived from a superficial papillary transitional cell carcinoma (TCC). We examined 13 sequence-tagged site (STS) markers mapped along 9q32-q33 by polymerase chain reaction (PCR), and used 13 bacterial artificial chromosome (BAC)/bacteriophage P1-derived artificial chromosome (PAC) genomic clone probes representing these STS markers as probes for dual-color fluorescence in situ hybridization (FISH) analyses to define the deleted region cytogenetically and at the molecular level. Southern blotting confirmed the findings. This combination of techniques revealed that the homozygous deletion in the KYBTDS cell line involved less than 1 megabase of DNA, flanked by markers A003P42 and SGC33380. This interval overlaps part of a common region of deletion observed in a number of primary bladder cancers; moreover, the DNA sequence within the 1-Mb segment corresponds to part of a YAC genomic clone that encompasses a putative tumor suppressor gene, DBCCR1.

Content analysis of group work sessions in the context of an educational program for inpatient diabetes patients

This study investigated the changes in emotions and attitudes of diabetic patients as observed in group work sessions linked to an inpatient diabetic educational program. Using content analysis of transcripts from Sessions 1 and 3 of 8 selected groups (40 patients), in Session 1 negative emotions or attitudes such as anxiety, remorse, or self-blame, a lack of understanding of diabetes, along with a willingness to undertake self-care were frequently expressed. In Session 3, more positive emotions and attitudes towards self-care (willingness, specific plans, and resolutions), satisfaction, and relief or hope were frequently expressed. These results suggest that the patients participating in the group work sessions moved toward adaptation to diabetes, although the effects of the group work were not separated from those of the inpatient educational program.

[Evaluation of endoscopic papillary balloon dilation (EPBD) using one-step catheter for removal of common bile duct stones]

We compared the results of EPBD in 18 patients using one-step catheter (one-step group) with those in 46 patients using usual two-step catheter (two-step group). The frequency of endoscopy and bile duct clearance were the equal in both groups. Pancreatitis occurred in only one patient of two-step group. Elevations of the amylase values were the equal in both groups. Amylase values after EPBD tended to decrease in 11 patients whose amylase values were above 500 IU/l before EPBD. Using one-step catheter in EPBD was useful for removing common bile duct stones easily and safety.

Suicide gene therapy for chemically induced rat bladder tumor entailing instillation of adenoviral vectors

The efficacy of an in vivo gene therapy protocol making use of an adenoviral vector in the treatment of bladder cancer was examined. Bladder tumors were induced in rats by oral administration of BBN (N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine). Histologically, such tumors resemble those seen in human bladder cancer, and the cells can be selectively transduced using adenoviral vectors. The therapeutic protocol thus entailed instillation of an adenoviral vector containing the HSV‐tk suicide gene into rat bladder followed by a regimen of intraperitoneal ganciclovir (GCV) injections. Histological examination after a short‐term GCV regimen (3 days) revealed marked vacuolization of the tumor cells. Moreover, TUNEL assays showed that the cytotoxic reaction was mediated by apopto‐sis. Following a long‐term GCV regimen (14 days), tumor growth was significantly inhibited and glandular metaplasia was observed. This is the first report demonstrating the efficacy of in vivo suicide gene therapy in a chemically induced transitional cell carcinoma like that seen in most human bladder cancer. Intravesical instillation is already a well established clinical technique. Our findings indicate that now there is a strong potential for its incorporation into new and useful gene therapies aimed at the treatment of human bladder cancer.

Evaluation of the retinal nerve fiber layer thickness in eyes with idiopathic macular holes

PURPOSE

To compare the retinal nerve fiber layer thickness in eyes with idiopathic macular holes and age-matched normal controls using scanning laser polarimeter.

METHODS

The retinal nerve fiber layer thickness was measured in 40 eyes of 40 consecutive patients with idiopathic macular hole (stage 1, 10 eyes; stage 2, eight eyes; stage 3, 15 eyes; stage 4, seven eyes) and 40 eyes of 40 age-matched normal controls with a scanning laser polarimeter. The retinal nerve fiber layer thickness within a 10-pixel-wide ellipse located concentrically with the disk and located 1.5-disk diameters from the center of the disk was measured. The mean overall retinal nerve fiber layer thickness of the peripapillary retina, four 90-degree quadrants, and 16 equal sectors of every 22.5 degrees was calculated for both groups. The retinal nerve fiber layer thickness in the two groups was statistically compared.

RESULTS

The mean retinal nerve fiber layer thickness measurement for the overall peripapillary retina and for three of the four 90-degree quadrants was not significantly different between the two groups. However, the temporal 90-degree quadrant was significantly thinner in the macular hole group (47.2 versus 54.6 microm, P =.026). For the 16 sectors of 22.5 degrees, the lower three sectors of the four sectors in the temporal quadrant were thinner in the macular hole group (P <.05).

CONCLUSIONS

The retinal nerve fiber layer thickness of the papillomacular area is thinner in eyes with idiopathic macular hole than that in normal eyes. The progressive thinning of the retinal nerve fiber layer thickness as the stage of the macular hole advances may suggest that surgery should be done at the earliest stage.

Adenovirus-mediated ex vivo gene transfer of basic fibroblast growth factor promotes collateral development in a rabbit model of hind limb ischemia

Adenovirus-mediated ex vivo gene transfer of basic fibroblast growth factor (bFGF), a new strategy for the treatment of chronic vascular occlusive disease, was examined in a rabbit model of hind limb ischemia. The left femoral artery was completely excised to induce an ischemic state in the hind limb of male rabbits. Simultaneously, a skin section was resected from the wound, and host fibroblasts were cultured. The cultured fibroblasts were infected with adenovirus vector containing modified human bFGF cDNA with the secretory signal sequence (AxCAMAssbFGF) or LacZ cDNA (AxCALacZ). At 21 days after femoral artery excision, the gene-transduced fibroblasts were administered through the left internal iliac artery. The fibroblasts significantly accumulated in the ischemic hind limb, and the AxCAMAssbFGF-treated cells secreted bFGF for less than 14 days without elevation of systemic bFGF level. At 28 days after cell administration, calf blood pressure ratio, angiographic score, capillary density of muscle tissue and blood flow of the left internal iliac artery were determined, and animals with AxCAMAssbFGF-treated cells showed significantly greater development of collateral vessels, as compared with those with AxCALacZ-treated cells. These findings suggest that adenovirus-mediated ex vivo gene transfer of bFGF was effective for improvement of chronic limb ischemia.

[Usefulness of power Doppler ultrasound in a patient with renal cell carcinoma in the wall of a simple renal cyst]

We present a case of renal cell carcinoma in the wall of a simple renal cyst. A 54-year-old man visited our hospital with a complaint of right back pain. Ultrasound study revealed right hydronephrosis, a ureteral stone, and a 9 x 8 cm renal cyst, with a tumor, 2 cm in diameter, in the cyst wall. Power Doppler Ultrasound and enhanced computed tomography demonstrated hypervascularity of the tumor. Clinically, he was diagnosed as renal cell carcinoma and nephrectomy was performed. Pathological findings of the tumor showed clear cell carcinoma in the wall of a simple renal cyst. Twelve months after the nephrectomy, he was free from recurrence.

The short-term effects of terazosin in Japanese men with benign prostatic hyperplasia

We evaluated the short-term efficacy of terazosin for treating symptomatic benign prostatic hyperplasia (BPH). Thirty men, aged 52 to 83 years (mean: 69.2 years) complaining of obstructive urinary symptoms due to BPH who had not received any prior treatment for their symptoms were orally administered 2 mg/day of terazosin. Symptoms (the total IPSS and the obstructive and irritative symptom scores) and objective parameters (peak flow rate [Qmax] and prostatic volume) were evaluated before treatment and after 1, 2, and 4 weeks of treatment. The mean total IPSS and the mean symptom scores for weak stream and nocturia were significantly decreased after only 1 week of treatment, while the mean scores for emptying, frequency, and urgency were significantly decreased after 2 weeks of treatment. However, the mean scores for intermittency and hesitancy did not decrease significantly at any time during treatment. Regarding objective parameters, the mean Qmax was significantly improved after 1 week of treatment, but the mean prostatic volume remained almost unchanged after 4 weeks. In conclusion, short-term terazosin therapy not only improved Qmax but also alleviated symptoms including irritative symptoms.

Urothelial mucosal concentration of levofloxacin administered before transurethral resection: Is the mucosal concentration predictable?

BACKGROUND

Although it is an established surgical technique, transurethral resection (TUR) is associated with a certain incidence of postoperative bacteriuria. Assessment was made whether the urothelial mucosal concentration of an antibiotic administered before TUR was high enough to decrease the incidence of urinary tract infection (UTI). Also investigated were factors predicting the organ concentration.

METHODS

Forty-nine patients (45 men and four women aged 51-79 years with a median age of 70 years) who underwent TUR between August 1996 and September 1997 were enrolled in the study. Each patient received 200 mg of levofloxacin (LVFX) about two hours before surgery. Blood and bladder urine were collected and urothelial mucosa was harvested at the time of TUR. Then the LVFX concentration in these samples was measured using high-performance liquid chromatography. The association between drug levels, or the ratio to the serum concentration, and factors likely to affect the vascular system that delivers the drug (age, bodyweight, blood pressure, pulse rate, total cholesterol and diabetes mellitus) were investigated.

RESULTS

The mean serum drug level was 2.4 microg/mL, and it was 206.4 microg/mL in the urine and 5.7 microg/mL in the urothelial mucosa. The mean ratio of the mucosal to serum concentrations was 2.6. The urinary drug concentration showed no association with any of the factors assessed, while the serum concentration decreased with increasing bodyweight (P = 0.03). As the diastolic blood pressure increased, both the mucosal drug concentration and the mucosa/serum ratio decreased (P < 0.01). When the relationship between the serum and mucosal concentrations was investigated, no correlation was found. However, the mucosa/serum ratio (indicating the transfer of LVFX from the blood) was positively correlated with the mucosal concentration.

CONCLUSION

Preoperative administration of LVFX was demonstrated to have potential value for the prophylaxis of UTI after TUR. Both the mucosal concentration and the mucosa/serum ratio were correlated with the diastolic blood pressure. As the diastolic blood pressure seems to be an indicator of the tissue concentration of LVFX, it may be possible to set the optimum dose based on the diastolic pressure.