Dose optimization for MORAb-202, an antibody-drug conjugate (ADC) highly selective for folate receptor-alpha (FRα), using population pharmacokinetic (PPK) and exposure-response (E-R) efficacy and safety analyses

3090

Background: MORAb-202 is an ADC consisting of farletuzumab (an antibody that binds to FRα) paired with eribulin mesylate (a microtubule dynamics inhibitor) conjugated via a cathepsin B-cleavable linker. A phase 1 dose-escalation and expansion study in patients with advanced solid tumors evaluated MORAb-202 doses ranging from 0.3 mg/kg to 1.2 mg/kg IV every 3 weeks (Shimizu 2021, CCR). The dose-expansion part included starting doses of 0.9 mg/kg and 1.2 mg/kg in an ovarian cancer (OC) cohort. Objective response rates (ORR) by investigator per RECIST v1.1 and rates of all-grade interstitial lung disease (ILD), an adverse event of interest, were lower at the 0.9 mg/kg dose vs the 1.2 mg/kg dose. To support dose optimization for clinical benefit while reducing the risk of ILD, a MORAb-202 PPK model was developed to characterize the pharmacokinetics and to obtain model-predicted exposure measures. Methods: Exposure was predicted for different dosing scenarios: flat dosing, bodyweight (BW)-based dosing with or without a dose cap, adjusted ideal BW dosing, and body surface area (BSA)-based dosing. E-R analyses for efficacy (ie, ORR) and safety (ie, ILD by expert review) were conducted using logistic-regression analysis. Simulations (N = 1000) were performed using a BW distribution from a previous phase 3 farletuzumab study in OC (Vergote 2016, JCO) to predict the probability of ORR and ILD in patients treated with MORAb-202. Results: MORAb-202 exposures were dose proportional, and the pharmacokinetics were described by a 2-compartment model with zero-order IV infusion and first-order elimination. Patients with higher BW had less-than-proportional increases in clearance (allometric exponent [AE] 0.571) and distribution volume (AE 0.524). MORAb-202 demonstrated a positive exposure (based on area under the curve [AUC]) dependence to ORR and ILD. The probability of achieving a tumor response was higher with higher AUC (odds ratio [OR] for an AUC unit change of 1000 µg•h/mL: 1.73 [95% CI 1.06–3.11]). The probability of an ILD event was higher with higher AUC (OR for an AUC unit change of 1000 µg•h/mL: 3.50 [95% CI 1.89–7.81]). Simulations across BW ranges (34.2–144 kg) indicated that BSA-based dosing (33 mg/m2), compared with BW-based dosing (0.9 mg/kg), yielded similar predicted median (90% prediction interval) rates for ORR (33.7% [19.3–62.2] vs 37.9% [20.6–67.5]) and all-grade ILD (46.8% [18.2–88.2] vs 55.1% [20.7–91.9]). However, BSA-based dosing is predicted to reduce ILD in the highest BW quartile (> 80–144 kg) by approximately 35% compared with BW-based dosing. Conclusions: Based on this assessment, BSA-based dosing is predicted to lower the exposure-dependent ILD risk in patients with higher BW and is being further evaluated in ongoing clinical studies. Clinical trial information: NCT03386942.

Safety and efficacy of MORAb-202 in patients (pts) with platinum-resistant ovarian cancer (PROC): Results from the expansion part of a phase 1 trial

5513

Background: MORAb-202 is an antibody-drug conjugate consisting of farletuzumab (an antibody that binds to folate receptor alpha [FRα]) paired with eribulin mesylate (a microtubule dynamics inhibitor) conjugated via a cathepsin-B–cleavable linker. The dose-escalation part of this phase 1 study confirmed antitumor activity in pts with ovarian cancer (Shimizu 2021, CCR); based on efficacy and safety, MORAb-202 0.9 mg/kg and 1.2 mg/kg Q3W were chosen as doses for the expansion part of this study in pts with PROC. Methods: The primary objective for the expansion part of this phase 1 study conducted in Japan was to define the safety and tolerability of MORAb-202. Secondary objectives included PK characterization and efficacy assessment (best overall response, objective response rate, progression-free survival, and overall survival). Eligible pts included those who had received ≤2 regimens of chemotherapy after diagnosis of PROC, had measurable disease per RECIST v1.1, and an ECOG PS of ≤1. Pts (except those with high grade serous histology) in the expansion phase were required to be FRα positive. The expansion phase began at the 0.9 mg/kg dose (Cohort 1); Cohort 2 (1.2 mg/kg) was initiated after safety assessment of Cohort 1 was completed. Tumor responses were assessed per RECIST v1.1 by investigator. Results: Twenty-four pts were treated in Cohort 1 and 21 pts were treated in Cohort 2. Grade ≥3 TEAEs occurred in 33.3% of pts in Cohort 1 and 28.6% of pts in Cohort 2. The most common TEAE was interstitial lung disease (ILD)/pneumonitis at both dose levels (Cohort 1: 37.5% [n=9; 8 with grade 1, 1 with grade 2]; Cohort 2: 66.7% [n=14; 6 with grade 1, 7 with grade 2, 1 with grade 3]). Other common TEAEs of any grade were nausea (25.0%; 33.3%), pyrexia (33.3%; 42.9%), malaise (16.7%; 28.6%), and headache (12.5%; 47.6%), in Cohorts 1 and 2, respectively. ORR was 25.0% and 52.4% in Cohorts 1 and 2, respectively (Table). Antitumor activity was observed across FRα-expression levels (<50% and ≥50%) and will be presented. Conclusions: In the PROC population, antitumor activity was seen with both the MORAb-202 0.9 mg/kg and 1.2 mg/kg doses. While pt numbers were small, efficacy was observed irrespective of FRα-expression levels. ILD/pneumonitis was the most common TEAE and was low grade in most pts. Dose optimization is ongoing to maximize the benefit/risk profile of MORAb-202. Clinical trial information: NCT03386942. [Table: see text]

Prognostic impact of heart mate risk score among elderly heart failure patients with non-responder for cardiac resynchronization therapy

Background

For patients with severe heart failure (HF) who are not eligible for transplantation, there is destination therapy (DT) that uses a continuous flow left ventricular assist device (LVAD). Implantation of LVAD improves HF and can be expected to improve the prognosis of life. Elderly refractory HF patients with non-responders for cardiac resynchronization therapy (CRT) may benefit from LVAD as DT. In considering indications of LVAD as DT for the elderly in Japan, conditions such as a low risk of Heart Mate Risk Score (HMRS) have been raised. HMRS has been shown to correlate with mortality in the cohort of LVAD patients enrolled in the Heartmate II trials.

Purpose

Because elderly CRT non-responder refractory HF patients are not indicated for transplantation and may benefit from LVAD as DT in Japan, we aimed to investigate the HMRS and prognosis among elderly CRT non-responders.

Methods

Of 467 patients underwent CRT implantation between 2000 and 2015, 157 were aged 65–75 years old. Of which 59 patients who could be determined to be non-responders based on echocardiographic data were included in this study. The primary endpoint was all-cause mortality, the secondary was readmission for HF and appropriate implantable cardioverter defibrillator (ICD) therapy.

Results

The patients' mean age was 68 years, males were 71%. The mean serum creatinine value was 1.1 mg/dl, albumin was 3.8 mg/dl, and BNP was 383 pg/ml. The mean left ventricular ejection fraction (LVEF) was 26%. The subjects were divided into 3 groups according to HMRS. The average of HMRS was 2.2, the low-risk group included 17 (29%) patients, the medium was 22 (37%), and the high was 20 (34%). There was no significant difference in age, LVEF, BNP, and NYHA functional classification at the time of CRT implantation between three groups. In the low-risk group, creatinine and INR were significantly lower, and albumin was significantly higher compared to the high-risk group. BNP tended to be lower in the low-risk group, but there was no significant difference. The mortality rate by HMRS was 12% in the low-risk group, 36% in the medium-risk group, and 50% in the high-risk group. On the Kaplan-Meier analysis, the low-risk group had a significantly lower mortality rate than the high-risk group (Figure). Furthermore, focusing on HF readmission, the rate of readmission was 59% in the low-risk group, 86% in the medium -risk group, and 65% in the high-risk group, and there was no significant difference between three groups. There was also no significant difference in appropriate ICD therapy between three groups.

Conclusion

Approximately 30% of elderly non-responders of CRT are in the low-risk group by HMRS and their mortality was lower than that of the other two groups. These elderly CRT non-responder patients might be considered a candidate for DT in Japan.

Funding Acknowledgement

Type of funding sources: None.

First-in-Human Phase 1 Study of MORAb-202, an Antibody-Drug Conjugate Comprising Farletuzumab Linked to Eribulin Mesylate, in Patients with Folate Receptor-α-Positive Advanced Solid Tumors

PURPOSE

MORAb-202, an antibody-drug conjugate containing farletuzumab and eribulin with a cathepsin-B cleavable linker, targets folate receptor α (FRα)-expressing tumor cells. The primary objective of this first-in-human study was to evaluate the safety and tolerability of MORAb-202 in patients with solid tumors.

PATIENTS AND METHODS

Patients ≥20 years with adequate organ function and FRα-positive solid tumors who failed to respond to standard therapy were eligible. Patients received MORAb-202 intravenously at doses of 0.3 to 1.2 mg/kg once every three weeks. Endpoints included dose-limiting toxicities, safety, tumor responses, pharmacokinetics, and pharmacodynamics.

TRIAL REGISTRATION NUMBER

NCT03386942 (ClinicalTrials.gov).

RESULTS

Between November 28, 2017 and June 4, 2019, 22 patients (median age, 58.0 years) with advanced solid tumors were enrolled. Treatment-emergent adverse events occurred in 21 (95%) patients, with leukopenia and neutropenia in 10 (45%) patients each. One patient (0.9 mg/kg cohort) experienced two grade 3 dose-limiting toxicities: serum alanine aminotransferase and γ-glutamyl transferase increases. Following review by an independent adjudication committee, grade 1/2 interstitial lung disease thought to be related to MORAb-202 was identified in five (23%) patients. Complete response, partial response, and stable disease were observed in one, nine, and eight patients, respectively. The normalized predose serum FRα tended to be positively correlated with the maximum tumor shrinkage (R ² = 0.2379; P = 0.0291).

CONCLUSIONS

The MTD of MORAb-202 was not reached. MORAb-202 demonstrated promising antitumor activity in FRα-positive solid tumors and was generally well-tolerated at the tested doses. Further investigations are required to establish appropriate dosage and clinical utility of MORAb-202.

P44 Impact of the distal radial artery approach in nursing service

Background

The distal transradial approach (dTRA) is a newly developed technique expected to reduce bleeding and other complications, such as occlusions, arising from the nature of the puncture site during transradial access. However, there is a paucity of data with regard to the nursing workload during or after achieving hemostasis. The present study aimed to evaluate the workload of the nursing service associated with dTRA in patients undergoing diagnostic coronary angiography (CAG).

Methods

 Two-hundred patients who underwent CAG using a 4-Fr sheath system in our hospital between October 2017 and September 2018 were enrolled in the study. Of the total, 100 patients underwent dTRA for CAG (dTRA group), and the other 100 patients underwent the conventional transradial approach (TRA) for CAG (TRA group). After CAG, continuous compression was performed for 3 hours in the TRA group using a TR Band™, which is a hemostasis device for TRA, to remove 2 ccs and 3 ccs of air at 30 and 120 minutes, respectively. If bleeding occurred, 1 to 2 ccs were replaced using the band, followed by a wait time of 15 minutes. Similarly, continuous compression was performed in the dTRA group usingSTEPTY™, a compression tape with a 6-mm-thick pad at the central portion, and the patient’s arm was wrapped in an elastic bandage for 2 hours after CAG. We compared the dTRA and TRA groups in terms of nursing workload associated with the achievement of hemostasis and the complications related to the puncture site.

Results

The nursing-service workload associated with the management of hemostasis, including the nursing hours, the time taken to measure vitals, and the recording times were found to be significantly shorter for the dTRA group compared to that of the TRA group (2.1 ± 0.5 vs 4.1 ± 0.7 times, p &lt; 0.001; 2.1 ± 0.4 vs 4.1 ± 0.7 times, p &lt; 0.001; 2.1 ± 0.4 vs 4.1 ± 0.6 times, p &lt; 0.001, respectively). Further, the number of cases requiring treatment for bleeding was fewer in the dTRA group than in the TRA group (3 vs 12 cases, p &lt; 0.05).

Conclusions

The workload of the nursing service associated with achieving hemostasis in the dTRA group was significantly lower compared to that in the TRA group. The introduction of dTRA for routine coronary catheterization possibly help in reducing the complications and the nursing workload in daily nursing practices.

First-in-human (FIH) phase 1 (Ph1) study of MORAb-202 in patients (pts) with advanced folate receptor alpha (FRA)-positive solid tumors

5544

Background: MORAb-202 is an antibody drug conjugate consisting of farletuzumab (a humanized monoclonal antibody that binds to FRA) paired with a cathepsin B-cleavable linker to eribulin mesylate (a microtubule dynamics inhibitor). We report preliminary results from a FIH Ph1 study of MORAb-202 in pts with FRA-positive solid tumors. Methods: This open-label, ongoing, FIH study evaluated the safety, tolerability, pharmacokinetics, pharmacodynamics, maximum tolerated dose, and/or the recommended dose of MORAb-202 (Part 1: Dose finding part with accelerated modified toxicity probability interval design; Part 2: Expansion part). Eligible pts had FRA-positive solid tumors who failed standard therapy and an ECOG PS of ≤1. MORAb-202 was administered by intravenous injection once every 3 weeks and dose-limiting toxicities (DLTs) were assessed during the first 21-day cycle. Efficacy endpoints were assessed with RECIST v1.1 by investigator assessment. Results: As of Nov 16, 2018, 16 pts with confirmed FRA-positive tumors were enrolled and treated with MORAb-202 across 4 dose levels in Part 1 (0.3mg/kg: n = 3 [2 endometrial and 1 ovarian], 0.45mg/kg: n = 3 [3 ovarian], 0.68mg/kg: n = 3 [1 NSCLC, 1 ovarian, and 1 TNBC], 0.9mg/kg: n = 7 [4 ovarian, 1 endometrial, 1 NSCLC, and 1 TNBC]); all completed > 1 cycle. One pt in the 0.9mg/kg cohort experienced DLTs of alanine aminotransferase increased (grade 3) and gamma-glutamyl transferase increased (grade 3). Treatment-emergent adverse events (TEAEs) occurred in 15 pts (93.8%). The most common TEAEs were leukopenia and neutropenia (50% each). The objective response rate based on RECIST v1.1 was 37.5% (6/16 pts) in Part 1 with 1 complete response (ovarian) at 0.9mg/kg and 5 partial responses including 2 pts (both ovarian) at 0.9mg/kg, 1 pt (endometrial) at 0.3mg/kg, and 2 pts (1 TNBC and 1 NSCLC) at 0.68mg/kg. The disease control rate was 75% (12/16 pts). Exposure to MORAb-202 was dose proportional across the dose range investigated. Conclusions: MORAb-202 escalation to 0.9mg/kg was manageable with encouraging initial antitumor activity in pts with FRA-positive solid tumors. Clinical trial information: NCT03386942.

Population Pharmacokinetic/Pharmacodynamic Analyses of Avatrombopag in Patients With Chronic Liver Disease and Optimal Dose Adjustment Guide With Concomitantly Administered CYP3A and CYP2C9 Inhibitors

Avatrombopag, a c-Mpl agonist, has been developed to provide an alternative therapy to standard platelet transfusion care for the treatment of thrombocytopenia. The main objectives of this article were to describe the pharmacokinetics (PK) of avatrombopag, to characterize the pharmacokinetic/pharmacodynamic (PK/PD) relationship between plasma avatrombopag concentrations and platelet count, and to identify potential intrinsic and extrinsic factors affecting PK or PK/PD in patients with chronic liver disease (CLD). Platelet count following avatrombopag administration with and without concomitant medication was further simulated using the final population PK/PD model to explore potential dose adjustments. Avatrombopag PK was described by a 1-compartment model with combined first- and zero-order absorption and linear elimination. The relationship between the plasma avatrombopag concentrations and platelet count was well described by a 6-compartment life-span model with a linear drug effect. The final PK and PK/PD models included statistically significant but not clinically relevant effects of body weight and CLD on apparent volume distribution and East Asian ethnicity, albumin, and thrombopoietin level on the slope parameter in the PK/PD relationship. PK/PD simulations showed comparable elevation in platelet count with and without concomitant cytochrome P450 (CYP) 3A and CYP2C9 inhibitors for the dosing regimens of 40 and 60 mg for 5 days, with predictions of <10% of CLD patients exceeding platelet count >200 × 10⁹ /L. Dose adjustment is therefore not necessary with concomitant use of CYP3A and CYP2C9 interacting drugs considering the limited treatment duration (ie, 5 days) and lack of significant safety concerns in CLD patients.

Pharmacokinetic/pharmacodynamic drug-drug interactions of avatrombopag when coadministered with dual or selective CYP2C9 and CYP3A interacting drugs

AIMS

Avatrombopag, a thrombopoietin receptor agonist, is a substrate of cytochrome P450 (CYP) 2C9 and CYP3A. We assessed three drug-drug interactions of avatrombopag as a victim with dual or selective CYP2C9/3A inhibitors and inducers.

METHODS

This was a three-part, open-label study. Forty-eight healthy subjects received single 20 mg doses of avatrombopag alone or with one of 3 CYP2C9/3A inhibitors or inducers: fluconazole 400 mg once daily for 16 days, itraconazole 200 mg twice daily on Day 1 and 200 mg once daily on Days 2-16, or rifampicin 600 mg once daily for 16 days. Pharmacokinetics, pharmacodynamics (platelet count) and safety of avatrombopag were evaluated.

RESULTS

Coadministration of a single 20-mg dose of avatrombopag with fluconazole at steady-state resulted in 2.16-fold increase of AUC of avatrombopag, prolonged terminal elimination phase half-life (from 19.7 h to 39.9 h) and led to a clinically significant increase in maximum platelet count (1.66-fold). Itraconazole had a mild increase on both avatrombopag pharmacokinetics and pharmacodynamics compared to fluconazole. Coadministration of rifampicin caused a 0.5-fold decrease in AUC and shortened terminal elimination phase half-life (from 20.3 h to 9.84 h), but has no impact on maximum platelet count. Coadministration with interacting drugs was found to be generally safe and well-tolerated.

CONCLUSIONS

The results from coadministration of fluconazole or itraconazole suggest that CYP2C9 plays a more predominant role in metabolic clearance of avatrombopag than CYP3A. To achieve comparable platelet count increases when avatrombopag is coadministered with CYP3A and CYP2C9 inhibitors, an adjustment in the dose or duration of treatment is recommended, while coadministration with strong inducers is not currently recommended.

Pharmacokinetics, Pharmacodynamics, Pharmacogenomics, Safety, and Tolerability of Avatrombopag in Healthy Japanese and White Subjects

Avatrombopag, an orally administered, small-molecule thrombopoietin receptor (c-Mpl) agonist, is currently in clinical development for the potential treatment of severe thrombocytopenia in patients with chronic liver disease undergoing an elective procedure. The objectives of this study were to characterize and compare the pharmacokinetics (including the food effect) and pharmacodynamics (platelet count) of avatrombopag following single doses in Japanese and white subjects. Following single dosing under fasted and fed conditions, mean peak concentrations occurred at 5 to 8 hours and subsequently declined with a half-life of 16 to 18 hours in Japanese and white subjects. Administration with food did not alter the rate or extent of avatrombopag absorption but substantially reduced pharmacokinetic variability relative to the fasted state. CYP2C9 polymorphism (*2, *3) was associated with higher pharmacokinetic variability but not with any clinically important effect on variability in platelet response. Plasma exposures of avatrombopag increased in a dose-proportional manner over the dose range tested. After a single dose, platelet count increased in a dose-related manner, reaching a maximum by day 11 and returning to baseline levels by day 27. No clinically important differences were found when avatrombopag pharmacokinetics and pharmacodynamics were compared between Japanese and white subjects. Administration of avatrombopag was generally well tolerated.

Safety, tolerability and pharmacokinetics of a novel phosphodiesterase inhibitor, E6005 ointment, in healthy volunteers and in patients with atopic dermatitis

OBJECTIVES

The purpose of the present studies was to assess the safety, tolerability and pharmacokinetics of topical application of a novel phosphodiesterase inhibitor, E6005, in healthy volunteers and in patients with atopic dermatitis (AD).

METHODS

In two randomized, investigator-blind, vehicle-controlled studies, we evaluated the topical application of E6005 ointment at concentrations ranging from 0.01% to 0.2% in healthy volunteers (Study 001) and in patients with AD (Study 101).

RESULTS

Thirty-six subjects were enrolled in Study 001 and 40 in Study 101. Neither skin irritation nor photosensitization was observed with application of E6005 in Study 001. Four subjects receiving E6005 in Study 001 experienced a treatment-emergent adverse event (application site edema, increased alanine aminotransferase or erythema); three of these subjects discontinued the study. Two subjects receiving E6005 in Study 101 experienced an adverse event (gout or enterocolitis); one discontinued the study. Plasma concentrations of E6005 were below the limit of quantification (1 ng/ml) in both studies.

CONCLUSION

E6005 ointment exhibited acceptable safety and tolerability. Topical application of E6005 ointment resulted in very low systemic exposure to E6005 in healthy volunteers and in patients with AD.

Curcumin ameliorates streptozotocin-induced liver damage through modulation of endoplasmic reticulum stress-mediated apoptosis in diabetic rats

We investigated the effect of curcumin on liver injury in diabetic rats induced by streptozotocin (STZ) through modulation of endoplasmic reticulum stress (ERS) and unfolded protein response (UPR). Experimental diabetes was induced by a single intraperitoneal injection of STZ (55 mg/kg), and curcumin was given at 100 mg/kg by gavage for 56 days. We observed that curcumin improved the morphological and histopathological changes, significantly decreased hepatic ERS marker protein: glucose-regulated protein 78, and improved liver function in diabetic rats. Moreover, treatment with curcumin markedly decreased the sub-arm of the UPR signaling protein such as phospho-double-stranded RNA-dependent protein kinase-like ER kinase, CCAAT/enhancer-binding protein homologous protein, tumor necrosis factor receptor-associated factor 2, and inositol-requiring enzyme1α; and inhibited tumor necrosis factor α, interleukin 1β, phospho-p38 mitogen-activated protein kinase, and apoptosis signal-regulating kinase 1 in liver tissues of diabetic rats. Apoptotic and anti-apoptotic signaling proteins, such as cleaved caspase-3 and B-cell lymphoma 2, were significantly increased and decreased, respectively in diabetic rats; curcumin treatment prevented all of these alterations. In summary, our results indicate that curcumin has the potential to protect the diabetic liver by modulating hepatic ERS-mediated apoptosis, and provides a novel therapeutic strategy for the diabetic liver damage.

Zonisamide up-regulated the mRNAs encoding astrocytic anti-oxidative and neurotrophic factors

Zonisamide has been proven as an effective drug for the recovery of degenerating dopaminergic neurons in the animal models of Parkinson's disease. However, several lines of evidence have questioned the neuroprotective capacity of zonisamide in animal models of Parkinson's disease. Although it suppresses dopaminergic neurodegeneration in animal models, the cellular and molecular mechanisms underlying the effectiveness of zonisamide are not fully understood. The current study demonstrates the effects of zonisamide on astrocyte cultures and two 6-hydroxydopamine-induced models of Parkinson's disease. Using primary astrocyte cultures, we showed that zonisamide up-regulated the expression of mRNA encoding mesencephalic astrocyte-derived neurotrophic factor, vascular endothelial growth factor, proliferating cell nuclear antigen, metallothionein-2, copper/zinc superoxide dismutase, and manganese superoxide dismutase. Similar responses to zonisamide were found in substantia nigra where the rats were pre-treated with 6-hydroxydopamine. Notably, pharmacological inhibition of 6-hydroxydopamine-induced toxicity by zonisamide pre-treatment was also confirmed using rat mesencephalic organotypic slice cultures of substantia nigra. In addition to this, zonisamide post-treatment also attenuated the nigral tyrosine hydroxylase-positive neuronal loss induced by 6-hydroxydopamine. Taken together, these studies demonstrate that zonisamide protected dopamine neurons in two Parkinson's disease models through a novel mechanism, namely increasing the expression of some important astrocyte-mediated neurotrophic and anti-oxidative factors.

Promoter CpG methylation in cancer cells contributes to the regulation of MUC4

Mucin 4 (MUC4) is a high molecular weight transmembrane mucin that is overexpressed in many carcinomas and is a risk factor associated with a poor prognosis. In this study, we show that the DNA methylation pattern is intimately correlated with MUC4 expression in breast, lung, pancreas and colon cancer cell lines. We mapped the DNA methylation status of 94 CpG sites from −3622 to +29 using MassARRAY analysis that utilises base-specific cleavage of nucleic acids. MUC4-negative cancer cell lines and those with low MUC4 expression (eg, A427) were highly methylated near the transcriptional start site, whereas MUC4-positive cell lines (eg, NCI-H292) had low methylation levels. Moreover, 5-aza-2′-deoxycytidine and trichostatin A treatment of MUC4-negative cells or those with low MUC4 expression caused elevation of MUC4 mRNA. Our results suggest that DNA methylation in the 5′ flanking region play an important role in MUC4 gene expression in carcinomas of various organs. An understanding of epigenetic changes in MUC4 may contribute to the diagnosis of carcinogenic risk and prediction of outcome in patients with cancer.

Plasma amantadine concentrations in patients with Parkinson's disease

We determined plasma amantadine concentrations in patients with Parkinson's disease (PD) in daily clinical practice and investigated the relationship between plasma concentration and adverse reactions to clarify the safe therapeutic range. Seventy-eight consecutive PD patients on stable amantadine treatment were recruited. Plasma concentration of amantadine was measured 3h after the administration of morning amantadine dose. Serum creatinine was measured to estimate renal function. The mean daily dose of amantadine was 135.1+/-62.3mg/day, and the mean plasma amantadine concentration was 812.5+/-839.5 ng/ml (range, 91-4400 ng/ml). Plasma amantadine concentration increased according to increasing renal dysfunction. Three patients exhibited adverse reactions, such as myoclonus, hallucinations, and delirium, and all of them showed plasma amantadine concentration >3000 ng/ml. None of the three cases had previously shown such side effects. PD patients who have not developed any psychiatric symptoms as adverse reactions to the treatment may develop myoclonus, hallucination, or delirium when the plasma concentration of amantadine exceeds 3000 ng/ml. It is therefore recommended to use amantadine at the plasma concentration of less than 3000 ng/ml in the treatment of Parkinson's disease, especially in elderly patients.

Delayed L-DOPA-induced hyperalgesia

Previously we reported on L-DOPA's antinociceptive effect on substance P-induced nociceptive behaviors in mice [Shimizu T, Iwata S, Morioka H, Masuyama T, Fukuda T, Nomoto M. Antinociceptive mechanism of L-DOPA. Pain 2004;110;246-9.]. Since significant hyperalgesia was noted following antinociception, our study was designed to investigate the mechanism of this hyperalgesia. Nociceptive behaviors were enhanced 2 h after L-DOPA administration. L-DOPA induced hyperalgesia occurred after conversion to dopamine because co-administration of benserazide, a DOPA decarboxylase inhibitor, completely abolished the L-DOPA-induced hyperalgesia. The D2 receptor agonist, quinpirole, depressed these behaviors entirely, while the D1 antagonist, SCH23390, inhibited the enhancement of these behaviors by L-DOPA. The D2 receptor antagonist, sulpiride, which induced hyperalgesia of the substance P-induced behaviors in naive mice, did not have any effects on L-DOPA-induced hyperalgesia. Spinal cord dopamine content increased rapidly after L-DOPA administration, exhibiting levels 100 times greater than baseline, and then returned to control after 1 h. These results suggested that the dopaminergic inhibitory system for pain sensation was temporarily impaired by excess amounts of exogenous dopamine that were derived from L-DOPA and both D1 and D2 receptors were involved in L-DOPA-induced hyperalgesia.

Expression of mucins (MUC1, MUC2, MUC5AC and MUC6) in mucinous carcinoma of the breast: comparison with invasive ductal carcinoma

AIMS

Mucinous carcinoma of the breast usually shows less frequent lymph node metastasis and more favourable outcome compared with invasive ductal carcinoma. The aim of this study is to compare the expression profiles of several mucins in mucinous carcinomas and invasive ductal carcinomas to gain insight into the relationship between the less aggressive biological nature of mucinous carcinoma and the role of mucins.

METHODS AND RESULTS

We examined the expression profiles of MUC1 (membrane-bound mucin) of different glycoforms (from non-glycosylated form to fully glycosylated form), MUC2 (intestinal type secretory mucin), MUC5AC (gastric surface type secretory mucin) and MUC6 (gastric pyloric gland type secretory mucin) in 17 mucinous carcinomas and 46 invasive ductal carcinomas using immunohistochemistry. Various glycoforms of MUC1 were expressed frequently in both mucinous carcinomas (65-100%) and invasive ductal carcinomas (92-100%), although non-glycosylated MUC1 (MUC1/CORE) and fully glycosylated MUC1 (MUC1/HMFG-1) showed significantly lower expression rates in mucinous carcinomas compared with those in invasive ductal carcinomas. The expression rates of MUC2 (94%) and MUC6 (71%) in mucinous carcinomas were significantly higher than those of MUC2 (15%) and MUC6 (15%) in invasive ductal carcinomas. There was no significant difference in the expression rate of MUC5AC in mucinous carcinomas (12%) and that in invasive ductal carcinomas (4%).

CONCLUSIONS

The expression rate of MUC1/CORE and MUC1/HMFG-1, which is related to poor prognosis in the gastric and colorectal cancers, is low in mucinous carcinomas. The high expression rate of gel-forming secretory mucins (MUC2 and MUC6) in mucinous carcinoma suggests that high production of these types of mucins may act as a barrier to cancerous extension resulting in their less aggressive biological behaviour.

Circulating immunoglobulin-bound transforming growth factor beta at a late tumour-bearing stage impairs antigen-specific responses of CD4+ T cells

In order to elucidate the mechanisms by which tumour-specific CD4+ T-cell responses are impaired during tumour development, an attempt was made to identify factors which impair CD4+ T-cell responses at a late tumour-bearing stage. Plasma from mice bearing B16 melanoma for 30 days (plasma d30) showed a more profound immunosuppressive effect on the in vitro proliferation of unrelated antigen-specific CD4+ T cells in the presence of both antigen and antigen-presenting cells (APC) than plasma from naïve mice. The level of plasma transforming growth factor (TGF)- was elevated in mice bearing B16 melanoma for 30 days compared with naïve mice, and the suppressive effect of plasma d30 was partially diminished by the neutralization of TGF-. Interestingly, immunoglobulin (IgG)-bound TGF-, but not IgG-unbound TGF-, in plasma d30 was suggested to be responsible for the immunosuppressive activity. In addition, no suppressive effect of plasma d30 was observed when antigen was added as a class II peptide, thus suggesting that the impaired proliferation of CD4+ T cells in the presence of plasma d30 was due to a dysfunction of antigen uptake/processing by APC. Furthermore, dissociation between IgG and TGF- resulted in a loss of the suppressive activity of plasma d30. Taken together, these results suggest that circulating IgG-bound TGF- is, at least in part, responsible for the impaired responses of CD4+ T cells at the late tumour-bearing stage by suppressing antigen uptake/ processing by APC.

Chronic estrogen treatment replaces striatal dopaminergic function in ovariectomized rats

Eight-week-old female Sprague-Dawley rats were divided into three groups: ovariectomized rats (OVX); ovariectomized rats treated with estradiol valerate (E2), 20 microg subcutaneously (s.c.) twice weekly for 12 weeks (OVX+E2 group); and sham-operated control rats treated with vehicle alone (controls). Spontaneous locomotor activity was measured for 24 h, and then again after the administration of methamphetamine (1 mg/kg, i.p.). In addition, striatal contents of dopamine (DA) and its metabolites were measured. Using an in vivo microdialysis technique, changes in extracellular striatal dopamine concentration were studied in a separate set of similarly treated rats after the administration of methamphetamine (0.2 mg/kg, i.p.). Spontaneous locomotor activity decreased in the OVX group, and estradiol replacement reversed this decreased activity. No significant differences were observed in the contents of DA and its metabolites at the striatum among the three groups. The basal output of DA at the striatum was lower in the OVX group than in those of the other two groups. Extracellular DA concentration following methamphetamine administration was also lower in the rats of OVX group. These results indicate that ovariectomy decreases spontaneous locomotor activity, response to methamphetamine, and striatal DA release in the female rats. Chronic replacement of estrogen reversed spontaneous locomotor activity and DA release by the striatum. These results suggest that chronic administration of estrogen may be beneficial in the treatment of female menopausal patients with Parkinson's disease.

Expression of UDP-GalNAc: polypeptide N-acetylgalactosaminyltransferase isozymes T1 and T2 in human colorectal cancer

Uridine diphosphate (UDP)-GalNAc: polypeptide N-acetylgalactosaminyltransferase (GalNAc transferase) catalyzes the initial step in mucin type O-glycosylation, and its expression has been assumed to be altered between normal epithelial cells and cancer cells. We studied the alteration of GalNAc transferase expression during the carcinogenesis of human colorectal epithelial cells. We produced polyclonal antibodies against synthetic polypeptides with specific sequence to two GalNAc transferase isozymes, T1 and T2. Surgically resected specimens from 50 patients with colorectal cancer were immunohistochemically stained, and the staining grade (percentage of positively stained cells) was compared between cancer and its normal counterpart in the same specimen. Significant signals for both T1 and T2 expression were seen in the supranuclear region of normal and cancer cells, indicating the subcellular localization of the enzymes in the Golgi apparatus. The prevalence of positive staining for T1 and T2 expression in colorectal cancer was significantly higher than that in normal epithelium (P < 0.05). However, the difference in staining grades between cancer and normal tissues varied in each patient. These results indicate that there is variability in the expression patterns of GalNAc transferase isozymes in normal and cancerous cells colorectal among individuals.

Interaction with p53 enhances binding of cisplatin-modified DNA by high mobility group 1 protein

A nonhistone chromosomal protein, high mobility group (HMG) 1, is ubiquitous in higher eukaryotic cells and binds preferentially to cisplatin-modified DNA. HMG1 also functions as a coactivator of p53, a tumor suppressor protein. We investigated physical interactions between HMG1 and p53 and the influence of p53 on the ability of HMG1 to recognize damaged DNA. Using immunochemical coprecipitation, we observed binding of HMG1 and p53. Interaction between HMG1 and p53 required the HMG A box of HMG1 and amino acids 363-376 of p53. Cisplatin-modified DNA binding by HMG1 was significantly enhanced by p53. An HMG1-specific antibody that recognized the A box of this protein also stimulated cisplatin-modified DNA binding. These data suggest that an interaction with either p53 or antibody may induce conformational change in the HMG1 A box that optimizes DNA binding by HMG1. Interaction of p53 with HMG1 after DNA damage may promote activation of specific HMG1 binding to damaged DNA in vivo and provide a molecular link between DNA damage and p53-mediated DNA repair.

Y box-binding protein-1 binds preferentially to single-stranded nucleic acids and exhibits 3'-->5' exonuclease activity

We have previously shown that Y box-binding protein-1 (YB-1) binds preferentially to cisplatin-modified Y box sequences. Based on structural and biochemical data, we predicted that this protein binds single-stranded nucleic acids. In the present study we confirmed the prediction and also discovered some unexpected functional features of YB-1. We found that the cold shock domain of the protein is necessary but not sufficient for double-stranded DNA binding while the C-tail domain interacts with both single-stranded DNA and RNA independently of the cold shock domain. In an in vitro translation system the C-tail domain of the protein inhibited translation but the cold shock domain did not. Both in vitro pull-down and in vivo co-immunoprecipitation assays revealed that YB-1 can form a homodimer. Deletion analysis mapped the C-tail domain of the protein as the region of homodimerization. We also characterized an intrinsic 3'-->5' DNA exonuclease activity of the protein. The region between residues 51 and 205 of its 324-amino acid extent is required for full exonuclease activity. Our findings suggest that YB-1 functions in regulating DNA/RNA transactions and that these actions involve different domains.

Transcriptional activation of the human HMG1 gene in cisplatin-resistant human cancer cells

The nonhistone chromosomal protein, high mobility group 1 (HMG1), which is ubiquitously expressed in higher eukaryotic cells, preferentially binds to cisplatin-modified DNA. The observation that HMG1 is overexpressed in cisplatin-resistant human cancer cells suggests that cisplatin resistance may be closely associated with HMG1. To decipher the mechanism of HMG1 overexpression in cisplatin-resistant cells, we isolated two overlapping genomic DNA clones containing the entire human HMG1 gene. These clones, which span approximately 15 kb of contiguous DNA, include 5 kb of the 5' flanking region as well as the entire coding sequence. We sequenced 1500 bp upstream of the first exon. The segment proximal to the transcription initiation site did not contain a TATA box but did possess an activating transcription factor site, an activator protein-2 site, one CCAAT box, and two CCAAT-binding transcription factor/nuclear factor-1 (CTF/NF-1) sites. HMG1 promoter activity was 3-10-fold higher in cisplatin-resistant KB-CP20 cells than in parental KB cells. An in vivo footprint experiment showed several differences of dimethyl sulfate modifications between KB and KB-CP20 cells in the area around the CTF/NF-1 sites. In addition, electrophoretic gel mobility shift assays showed that binding of a nuclear factor from cisplatin-resistant cells to the CTF/NF-1 site was significantly higher than the binding of the same factor from parental cells. Semiquantitative reverse transcription-PCR and Western blot analysis also showed that expression of CTF/NF-1 was 3-20-fold higher in the resistant cell line than in its parental counterpart. These findings suggest that, in cisplatin-resistant cells, the expression of HMG1 gene product is enhanced at the transcriptional level and that this probably occurs through the enhanced expression of the CCAAT binding factor, CTF/NF-1.

[Pharmacological treatments of Parkinson's disease]

Antiparkinsonian agents applied or under the investigation for the treatment of patients with Parkinson's disease were reviewed. Tremor, akinesia, rigidity and postual instability are key signs of Parkinson's disease. The most important one is akinesia, which includes decreased spontaneous locomotor activity, slowness of movement, awkwardness and freezing. The main pathophysiology of Parkinson's disease is neurodegeneration of nigrostriatal dopaminergic neurons. Neurotoxins or oxidative stress to the dopaminergic neurons have been discussed as one of the etiologies of degeneration. Antioxidant or neuroprotective agents will be the future drugs for Parkinson's disease. At present, supplement of dopamine by levodopa administration, retarding the metabolism of levodopa or dopamine by a dopa decarboxylase inhibitor (DCI), MAO-B (monoamine oxidase inhibitor type B) inhibitor or catechol-O-methyltransferase (COMT) inhibitor, dopamine receptor agonists, anticholinergic agents, dopamine release enhancer/uptake inhibitor, N-methyl-D-aspartate (NMDA) receptor antagonists are applied for the treatment of Parkinson's disease. New agents such as adenosine receptor antagonists, serotonergic agents and nicotinic receptor agonists are under investigation. Agents to facilitate the growth of nerves or to inhibit degeneration of nerves are also studied and will be developed for the treatment of Parkinson's disease in the future. In the case of familial Parkinson's disease, abnormal genes were identified. Gene therapy might be another future treatment for these cases.

Mucosal damage and recovery of the intestine after prolonged preservation and transplantation in dogs

BACKGROUND

Although much is known about the mucosal damage that occurs after intestinal warm ischemia and reperfusion and its recovery, little is known about the effect of cold preservation and transplantation on the mucosa. We studied the electrophysiological, biochemical, and histological changes of the intestinal mucosa after preservation for 24 hr and subsequent transplantation.

METHODS

The small intestines from adult mongrel dogs were harvested. The intestines were orthotopically autotransplanted immediately (control group) or after preservation for 24 hr (preservation group). Jejunal and ileal tissues were taken before harvesting, at the end of preservation, 1 hr after reperfusion, and on postoperative days 3, 7, 14, and 28. The Ussing chamber method was used to study the electrophysiologic changes. Tissue maltase, diamine oxidase, and ornithine decarboxylase were measured. A histological analysis was also performed.

RESULTS

Control group grafts showed no evident deterioration in electrophysiology, biochemistry, or morphology. In contrast, preservation group grafts exhibited electrophysiological and biochemical degradation, complete denudation of the villi, and crypt injury (especially in the ileum) after reperfusion. Electrophysiologic function and the mucosa biochemical marker recovered within 3 days in the jejunum and within 7-14 days in the ileum; however, histological recovery of mucosal injury required 28 days in the jejunum and more than 28 days in the ileum.

CONCLUSIONS

Our study showed that despite severe destruction of mucosal integrity by prolonged preservation and transplantation, the intestinal mucosa has an enormous regenerative capacity. Our study also showed that regeneration was more pronounced in the jejunum than in the ileum.

Persistent infection with Listeria monocytogenes in the kidney induces anti-inflammatory invariant fetal-type gammadelta T cells

After intraperitoneal inoculation with Listeria monocytogenes, gammadelta T cells appear in the peritoneal cavity preceding the appearance of alphabeta T cells. Such gammadelta T cells predominantly express T-cell receptor (TCR)Vgamma1/Vdelta6, develop through an extrathymic pathway, and contribute to host defence against the bacteria. We have observed a gradual increase in gammadelta T cells in kidneys of mice after intrarenal inoculation with L. monocytogenes, which resulted in an unusually long-lasting local infection. In this study, we examined the characteristics and the roles of the gammadelta T cells induced in this model. It was found that these gammadelta T cells predominantly expressed TCRVgamma6/Vdelta1 with canonical junctional sequences identical to those expressed on fetal thymocytes. Although depletion of such gammadelta T cells in vivo did not affect the number of bacteria, it resulted in histologically exacerbated inflammation in the kidneys. These results indicate that a persistent infection with L. monocytogenes in kidneys induces a different kind of gammadelta T cell from that induced after intraperitoneal infection. The former expresses invariant fetal-type Vgamma6/Vdelta1+TCR and plays a regulatory role in resolution of inflammation.

Regulation of GAP-43 protein and mRNA in nigrostriatal dopaminergic neurons after the partial destruction of dopaminergic terminals with intrastriatal 6-hydroxydopamine

Changes in the level of GAP-43 and its mRNA in nigrostriatal dopaminergic neurons in an animal model of the presymptomatic period of Parkinson's disease were measured to find the characteristic features of GAP-43 in nigrostriatal dopaminergic neurons. Since the dopaminergic neurons possess a relatively large amount of GAP-43 protein and mRNA, the dopaminergic neurons must be endowed with specific functions related to those of GAP-43. In this study, dopaminergic axon terminals were partially destroyed by intrastriatal 6-hydroxydopamine (6-OHDA). Rats were decapitated 3, 14, and 56 days following treatment. Levels of GAP-43 and tyrosine hydroxylase (TH) in the striatum were detected by immunoblotting and quantified. The number of GAP-43 mRNA-positive neurons and that of TH mRNA-positive neurons in the substantia nigra pars compacta (SNc) were detected by in situ hybridization using alkaline phosphatase (ALP)-labeled probes. Levels of GAP-43 in the striatum showed no significant alteration during the period of the experiment, although levels of TH were gradually restored. The number of GAP-43 mRNA-positive neurons as well as that of TH mRNA-positive neurons in the SNc decreased. These results suggests that dopaminergic neurons restore their axon terminals with little change in GAP-43, and that transcription and/or stability of GAP-43 mRNA in the dopaminergic neurons are susceptible to the toxin, although the dopaminergic neurons can maintain the translational product in the terminals. This feature may be related with a degeneration of dopaminergic neurons in Parkinson's disease.

TH protein and mRNA in nigrostriatal dopaminergic neurons are down-regulated by continuous but not intermittent apomorphine

Levels of tyrosine hydroxylase (TH) and TH mRNA were measured after administration of dopamine agonists for a long period of time to elucidate the long-term feedback inhibition of dopamine synthesis in nigrostriatal dopaminergic neurons. Continuous infusion, which desensitized presynaptic dopamine receptors, but not repeated administration, down-regulated TH and TH mRNA levels. This suggests levels of TH protein and mRNA are only feedback inhibited by the continuous stimulation of postsynaptic dopamine receptors.

Structural effects of O-glycosylation on a 15-residue peptide from the mucin (MUC1) core protein

To study the effect of O-glycosylation on the conformational propensities of a peptide backbone, the 15-residue peptide PPAHGVTSAPDTRPA (PPA15) from the MUC1 protein core and its analogue PPA15(T7), glycosylated with alpha-N-acetylgalactosamine on Thr7, were prepared and investigated by NMR spectroscopy. The peptide contains both the GVTSAP sequence, which is an effective substrate for GalNAc-T1 and -T3 transferases, and the PDTRP fragment, which is a well-known immunodominant epitope recognized by several anti-MUC1 monoclonal antibodies. Useful structural results were obtained in water upon decreasing the temperature to 5-10 degrees C. The sugar attachment slightly affected the conformational equilibrium of the peptide backbone near the glycosylated Thr7 residue. The clustering of low-energy conformations for both PPA15 and PPA15(T7) within the GVTSAP and APDTRP fragments revealed structural similarities between glycosylated and nonglycosylated peptides. For the GVTSAP region, minor but distinct clusters formed by either PPA15 or PPA15(T7) conformers showed distinct structural propensities of the peptide backbone specific for either the nonglycosylated or the glycosylated peptide. The peptide backbone of the APDTRP fragment, which is a well-known immunodominant region, resembled an S-shaped bend. A similar structural motif was found in the GVTSAP fragment. The S-shaped structure of the peptide backbone is formed by consecutive inverse gamma-turn conformations partially stabilized by hydrogen bonding. A comparison of the solution structure of the APDTRP fragment with a crystal structure of the MUC1 peptide antigen bound to the breast tumor-specific antibody SM3 demonstrated significant structural similarities in the general shape.

[Functions and metabolic rates of transmitters in the basal ganglia]

The caudate nucleus and putamen showed different neuronal circuits with the cerebral cortex and different functions in motor control. The dopamine content was same in the caudate nucleus and putamen, however, the turnover ratio was higher in the putamen than in the caudate nucleus, when it was studied in the control or MPTP-treated marmosets. The dopaminergic neurons projecting to the putamen seemed to show higher activity than those projecting to the caudate nucleus. The caudate nucleus is long in the shape and the dopamine turnover ratio was higher in the former part than in the latter part in normal marmosets. Administration of fluvoxamine increased akinesia in MPTP-treated common marmosets, and systemic administration of 8-OHDPAT, a 5-HT1A receptor or autoreceptor agonist reversed parkinsonism in MPTP-treated common marmosets. These results indicated that serotonergic neurons potentiated hypoactivity in parkinsonism and suppression of serotonergic function may contribute to the remission of parkinsonism.

Structure and functional analysis of the human STAT3 gene promoter: alteration of chromatin structure as a possible mechanism for the upregulation in cisplatin-resistant cells

STAT3 is involved in the signal transduction activated by various cytokines and growth factors. We found that the STAT3 gene is overexpressed in cisplatin-resistant cells. We isolated a genomic fragment containing the 5'-portion of the human STAT3 gene using a bubble PCR method. Using the bubble PCR product as a probe, one genomic clone was isolated. The nucleotide sequence of the first exon and the 1800 base pairs (bps) preceding it was determined. The promoter region of the human STAT3 gene is highly homologous to the corresponding region of the mouse STAT3 gene; several potential factor binding sites such as CRE/ATF, SBE, and GC boxes are also well conserved between human and mouse. A transient expression assay using the luciferase reporter gene showed that the sequence from -403 to +102 possesses maximal promoter activity, and transcription of the STAT3 gene was significantly higher in cisplatin-resistant cells than in parental cisplatin-sensitive cells. Deletion of the region between -261 and -167 resulted in significant loss of promoter activity in both parental and cisplatin-resistant cells. In vivo footprint analysis revealed several protein bindings; however, no significant differences were observed between drug-sensitive and drug-resistant cells. MNase digestion revealed that several open or active nucleosomes were only detected in cisplatin-resistant cells. These results suggest that STAT3 promoter function in a highly structured chromatin environment requires a complex interaction of several transcriptional factors.

Improvement of intestinal absorption of peptides: adsorption of B1-Phe monoglucosylated insulin to rat intestinal brush-border membrane vesicles

In a previous study we glycosylated insulin to improve its intestinal absorption. When the glycosylated product, p-(succinylamido)-phenyl-alpha-D-glucopyranoside (SAPG)-substituted insulin (SAPG-INS), was administered intra-intestinally to rats, it showed a greater hypoglycemic effect than native bovine insulin. The enhanced hypoglycemic effect of SAPG-INS was considered to be due to an increase in membrane permeability as well as an increase in resistance to enzymatic degradation. In particular, membrane permeability may be related to an interaction with the Na(+)-dependent D-glucose transporter (SGLT-1) which is located in the brush-border membrane of epithelial cells. The insulin product used in the previous study, however, comprised a mixture of mono-, di- and tri-SAPG-substituted insulin. In this study SAPG-INS with a defined substitution number and position was synthesized to examine the interaction between the transporter and glycosylated insulin in more detail. The new product was mono-SAPG-substituted insulin substituted at the B1-phenylalanine position (B1-SAPG-INS) and was selectively synthesized after protection of the A1-glycine and varepsilonB29-lysine amino acids. The hypoglycemic effect of B1-SAPG-INS in rats after an intravenous dose of 71 microg/kg was almost the same as that of native bovine insulin at a dose of 1 U/kg and B1-SAPG-INS retained about 60% of the immunoreactivity of native bovine insulin. The interaction of B1-SAPG-INS with the intestinal transporter was examined by a rapid filtration technique using (125)I-labeled B1-SAPG-INS and brush-border membrane vesicles (BBMVs) which were prepared from rat small intestine by the Mg-precipitation method. The amount of B1-SAPG-INS adsorbed or absorbed by BBMVs in the presence of an inward Na(+)-gradient into BBMVs was greater than that of native bovine insulin. This adsorption/absorption was significantly inhibited by the presence of 1 mM phloridzin. A similar inhibition was observed when Na(+) was replaced with K(+) and when B1-SAPG-INS was incubated with BBMVs at 4 degrees C. From the effect of osmolarity on the extent of adsorption/absorption, it was considered that B1-SAPG-INS was not taken up into the intravesicular space but adsorbed onto the external membrane surface of BBMVs. These findings suggested that B1-SAPG-INS was adsorbed specifically onto the transporter. The hypoglycemic effect of insulin was enhanced by glycosylation at the B1 position in in situ experiments using normal and diabetic rats. Consequently, it is suggested that B1-SAPG-INS was adsorbed specifically onto the glucose transporter of intestinal BBM. This specific adsorption may be involved in the mechanism of the enhanced hypoglycemic effect of B1-SAPG-INS both in normal and diabetic rats.

The metabolic rate and vulnerability of dopaminergic neurons, and adenosine dynamics in the cerebral cortex, nucleus accumbens, caudate nucleus, and putamen of the common marmoset

The pathophysiology of the striatum and cerebral cortex were studied from the pharmacological aspect. Investigation of the dopamine content in the cerebral cortex revealed that the premotor and motor area showed the highest level (61+/-6.2 ng/g). Intravenous injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) at a dose of 10 mg/kg reduced the dopamine content in the caudate nucleus and putamen to 2-3% of the control level in common marmosets, while it fell to 60% in the nucleus accumbens. There was no alteration of the dopamine content in the cerebral cortex. Immunohistochemical staining for tyrosine hydroxylase in the midbrains of MPTP-treated marmosets showed almost complete disappearance of dopaminergic cells from the substantia nigra and good preservation of cells in the ventrotegmental area. Dopaminergic cells projecting to the caudate/putamen, nucleus accumbens, and cerebral cortex showed marked, moderate, and no vulnerability to MPTP, respectively. After systemic administration of MPTP, dopaminergic neurons projecting to the caudate nucleus and putamen were damaged equally. However, the compensatory increase of dopamine turnover was more prominent in the putamen than in the caudate nucleus. Thus, nigroputaminal dopaminergic neurons may have a higher level of activity than neurons in the caudate. The neural connections and functions of the caudate nucleus and putamen have already been differentiated anatomically or physiologically. This compensatory increase of the dopamine turnover rate is another aspect of functional differences between the caudate nucleus and putamen. Investigation of the dopamine content in the head, body, and tail of the caudate nucleus showed no differences in the concentration of dopamine. However, a study of the metabolic rate of dopamine using alpha-methyl-p-tyrosine, a tyrosine hydoxylase inhibitor, showed higher metabolism of dopamine in the head of the caudate nucleus in common marmosets. Thus, dopaminergic neurons projecting to the caudate nucleus may show topographical differences in their firing rates. A microdialysis study indicated an increase in the metabolism of adenosine in the striatum of MPTP-treated animals. Cholinergic neurons are interneurons and are one of the main sources of adenosine in the striatum. Dopaminergic input from the substantia nigra acting on cholinergic neurons was decreased following MPTP treatment. The increase of adenosine metabolism suggested that cholinergic neurons in the striatum receive inhibitory inputs from nigrostriatal dopaminergic neurons.

Alcoholic fatty liver differentially induces a neutrophil-chemokine and hepatic necrosis after ischemia-reperfusion in rat

Primary graft nonfunction of steatotic liver allograft is one of the factors causing shortage of donor livers. Ischemia/reperfusion (I/R) injury is an important contributory factor to primary graft nonfunction. In this study, we investigated the complex chain of events from transcription factor activation to necrosis through cytokine induction and apoptosis in steatotic rat liver after warm I/R. Rats with alcoholic or nonalcoholic fatty liver were subjected to hepatic warm I/R and compared with control rats. Rats fed an ethanol diet for 6 to 8 weeks developed severe hepatic necrosis accompanied by increased neutrophil recruitment after I/R, compared with rats with nonalcoholic fatty liver or control. Hepatic apoptosis as assessed by DNA fragmentation at 4 hours after I/R, however, increased to a similar degree in each of the 2 fatty liver models compared with the control. Alcoholic fatty liver exposed to I/R showed a rapid increase in nuclear factor-kappaB (NF-kappaB) binding activity at 1 hour after I/R, which preceded an increased expression of tumor necrosis factor alpha (TNF-alpha) and cytokine-induced neutrophil chemoattractant-1 (CINC-1). In contrast, nonalcoholic fatty liver did not show such potentiation of either NF-kappaB activation or cytokine induction after I/R. Our results have indicated that alcoholic fatty liver may differentially induce CINC-1 production and hepatic necrosis after I/R. Furthermore, our results suggest that apoptosis per se does not always lead to necrosis in the liver following I/R.

Quantitative evaluation of genomic instability as a possible predictor for development of hepatocellular carcinoma: comparison of loss of heterozygosity and replication error

Both loss of heterozygosity (LOH) and replication error (RER) are considered to be phenotypes of genomic instability. To unveil the role of the genomic instability in hepatocarcinogenesis, frequencies of LOH and RER were simultaneously determined in 15 hepatocellular carcinomas (HCCs), surrounding nontumorous liver tissues (SL), and 13 liver tissues with chronic viral hepatitis void of cancer (NC) by referencing peripheral blood leukocytes (PBLs) from the corresponding donor using 18 microsatellite markers spread throughout the genome. LOH was significantly frequent in HCC compared with that in SL or NC (P =.005, P =.0003, respectively) and observed preferentially at particular microsatellite loci, D1S204, D2S123, D8S1106, D9S266, D16S748, and D19S601. Although the higher prevalence of RER was also significant in HCC compared with that in NC (P =.03), in most cases the errors were detected at very low frequencies and random loci. Both LOH and RER tended to appear more prevalently in SL than in NC. The occurrence rate of LOH was higher in the tissues associated with hepatitis B virus (HBV) than with hepatitis C virus (HCV) infection especially in HCC (P =.03). When referencing SL instead of PBLs, the prevalence of LOH and RER in HCC significantly decreased (P =.02 and P =.03, respectively). These results suggest that LOH is closely associated with multistep hepatocarcinogenesis especially under HBV infection, but RER is imperceptibly associated. The quantitative evaluation of the frequency of LOH by referencing PBLs may be a useful predictor for HCC development in chronic liver diseases.

A novel PTEN mutation in a Japanese patient with Cowden disease

Cowden disease (CD) is an autosomal dominant syndrome characterized by multiple hamartomatous lesions and an increased risk for malignancies. Recent evidence has indicated that the PTEN gene, encoding a protein tyrosine phosphatase, is the CD susceptibility gene. However, another line of evidence has suggested that CD might be genetically heterogeneous. Clinical features of CD are variable, and there are interfamilial differences in the expression of skin lesions. Therefore, information on PTEN mutations in CD patients should be accumulated to clarify the genotype-phenotype correlation. In the present study, we found heterozygous germline mutations of PTEN in all of three Japanese patients with CD examined, indicating no genetic heterogeneity among our patients. The mutations included two non-sense mutations of R335X and R130X, and a mis-sense mutation of C136R. To the best of our knowledge, the C136R mutation has not previously been reported in CD patients. This novel mutation was located outside the core motif of the phosphatase domain of PTEN protein, where most of the missense mutations previously reported in CD patients were clustered. Mucocutaneous manifestations were far fewer in the patient with this mutation than in the patients with nonsense mutations. Whether the phenotypic difference in mucocutaneous features was due to the different mutations remains unclear.