Treatment Burden on Once-Weekly Omarigliptin Versus Daily Dipeptidyl Peptidase-4 Inhibitors in Patients with Type 2 Diabetes: Randomized Controlled Trial (ONWARD-DPP4 Study)

INTRODUCTION

Preference for quality of life is important in deciding the treatment strategy for patients with type 2 diabetes mellitus. This study aimed to assess the effect of omarigliptin on patients' psychological attitudes and responses compared with daily dipeptidyl peptidase-4 inhibitors (DPP4is) by measuring the burden of pharmacotherapy using the Diabetic Treatment Burden Questionnaire (DTBQ).

METHODS

Patients with type 2 diabetes mellitus who were taking daily DPP-4is were enrolled and randomized to a group that switched to omarigliptin or a group that continued daily DPP4is and were monitored for 12 weeks. The primary endpoint was the change in the DTBQ score from baseline to week 12. The secondary endpoints included changes in blood test results, medication preferences and medication adherence.

RESULTS

The DTBQ total score significantly decreased from baseline to week 12 in both groups; however, no significant intergroup differences were observed. The DTBQ subscale, implementation and flexibility burden scores significantly decreased in the group that switched to omarigliptin, although no significant intergroup difference in the change was observed. DTBQ scores and medication preferences were associated with improvements in the DTBQ scores.

CONCLUSION

Although this study failed to demonstrate the improvement of DTBQ total score by switching from daily DPP4is to omarigliptin compared with continuing the daily DPP4is, the DTBQ subscale score implementation and flexibility burden score were significantly improved only in the group that switched to omarigliptin, suggesting the possibility of switching from daily DPP4is to omarigliptin to decrease the patients' medication burden.

TRIAL REGISTRATION

jRCTs031200437.

Comparison of tofogliflozin versus glimepiride as the third oral agent added to metformin plus a dipeptidyl peptidase-4 inhibitor in Japanese patients with type 2 diabetes: A randomized, 24-week, open-label, controlled trial (STOP-OB)

Metformin plus a dipeptidyl peptidase-4 inhibitor (DPP-4i) is the most common therapy for Japanese patients with type 2 diabetes. This 24-week, multicentre, open-label, parallel-group trial randomized patients on dual therapy to add-on tofogliflozin (20 mg/day, n = 33) or glimepiride (0.5 mg/day, n = 31). The primary outcome was change in body fat percentage. The secondary outcomes included changes in HbA1c, fat mass, fat-free mass, liver function variables and uric acid. Tofogliflozin and glimepiride reduced HbA1c to a similar extent. Body fat percentage did not change from baseline in either group. Fat mass was reduced by tofogliflozin but was increased by glimepiride (by -2.0 ± 1.7 kg and +1.6 ± 1.6 kg, P = .002). Fat-free mass was also reduced by tofogliflozin and increased by glimepiride (by -1.3 ± 1.3 kg and +0.9 ± 2.0 kg, P < .001). Alanine aminotransferase and uric acid levels were reduced by tofogliflozin (P = .006 and P < .001, respectively). These data provide novel information useful for selecting the third oral agent for patients whose diabetes is inadequately controlled with metformin plus DPP-4i dual therapy.

Efficacy of dapagliflozin versus sitagliptin on cardiometabolic risk factors in Japanese patients with type 2 diabetes: a prospective, randomized study (DIVERSITY-CVR)

Background

Few prospective studies have compared the cardiovascular benefits of sodium-glucose cotransporter-2 (SGLT2) inhibitors and dipeptidyl peptidase 4 (DPP-4) inhibitors. We aimed to clarify the efficacy of dapagliflozin versus sitagliptin for modulating cardiometabolic risk factors including high glycated hemoglobin (HbA1c) levels, hypoglycemia, and body weight.

Methods

This prospective, randomized, open-label, blinded-endpoint, parallel-group trial enrolled 340 Japanese patients with early-stage type 2 diabetes receiving metformin alone or no glucose-lowering agents, who were randomized to receive dapagliflozin or sitagliptin for 24 weeks. The primary endpoint was the proportion of patients who achieved the composite endpoint of HbA1c level maintenance < 7.0% (53 mmol/mol), avoidance of hypoglycemia (maintenance of sensor glucose ≥ 3.0 mmol/L or ≥ 54 mg/dL), and ≥ 3.0% body weight loss from baseline. Secondary endpoints included components of the primary endpoint, other metabolic indices, and glucose variability indices measured using flash glucose monitoring.

Results

Clinical characteristics of patients were age, 58.1 ± 12.2 years; known duration of diabetes, 5.8 ± 6.1 years; body weight, 74.7 ± 14.2 kg; body mass index, 27.9 ± 4.1 kg/m²; and HbA1c level, 7.8 ± 0.8% at baseline. The achievement ratio of primary endpoint was significantly higher in the dapagliflozin group than in the sitagliptin group (24.4% vs. 13.8%, P < 0.05). While the rates of HbA1c level maintenance < 7.0% (53 mmol/mol) and avoidance of hypoglycemia were comparable between the groups (49.4 vs. 50.0% and 88.7 vs. 92.3% for dapagliflozin vs. sitagliptin, respectively), body weight loss of ≥ 3.0% was significantly achieved in the dapagliflozin group (54.4 vs. 19.6%, P < 0.001). Moreover, dapagliflozin was superior to sitagliptin regarding several secondary endpoints that modulate cardiometabolic risk, namely reducing fasting plasma glucose, insulin, uric acid, increasing high-density lipoprotein cholesterol, and suppressing the increase in serum creatinine and the decrease in estimated glomerular filtration rate. On the other hand, sitagliptin was superior to dapagliflozin in suppressing glucose variability.

Conclusions

Compared to sitagliptin, dapagliflozin was significantly more effective at improving cardiometabolic risk factors, suggesting that SGLT2 inhibitors might be more suitable than DPP-4 inhibitors for preventing cardiovascular events in patients with early-stage but inadequately controlled type 2 diabetes.

Trial registration Trial number, UMIN000028014; registered on June 30, 2017

Emicizumab, the bispecific antibody to factors IX/IXa and X/Xa, potentiates coagulation function in factor XI-deficient plasma in vitro

Essentials Emicizumab mimics factor (F)VIIIa cofactor function, augments the intrinsic tenase activity. We assessed the emicizumab-driven hemostatic function in FXI-deficient plasmas. Emicizumab improved the coagulation potentials in severe FXI-deficient plasma. Emicizumab may provide a possibility for clinical application in patients with FXI deficiency. SUMMARY: Background Patients with factor (F)XI deficiency commonly present with markedly prolonged activated partial thromboplastin times (APTT), although bleeding phenotypes are heterogeneous. Emicizumab, a bispecific monoclonal antibody to FIX/FIXa and FX/FXa, mimics FVIIIa cofactor function on phospholipid (PL) surfaces. Antibody reactions were designed, therefore, to augment mechanisms during the propagation phase of blood coagulation. Aim To assess emicizumab-driven hemostatic function in FXI-deficient plasmas. Methods and Results Standard ellagic acid (Elg)/PL-based APTTs of different FXI-deficient plasmas (n = 13; FXI activity, < 1 IU dl-1 ) were markedly shortened dose dependently by the presence of emicizumab. To further analyze the effects of emicizumab, clot waveform analysis (CWA) in FXI-deficient plasmas with emicizumab, triggered by tissue factor (TF)/Elg demonstrated improvements in both clot times, reflecting the initiation phase, and coagulation velocity, which represents the propagation phase. Emicizumab also enhanced the TF/Elg-triggered thrombin generation in FXI-deficient plasmas dose-dependently although the degree of enhancement varied in individual cases. Thrombin generation with either FVII-deficient plasma or FIX-deficient plasma treated with anti-FXI antibody showed little or no increase by the co-presence of emicizumab, suggesting that the accelerated thrombin generation in FXI-deficient plasmas by emicizumab should depend on the FIXa-involved coagulation propagation initially triggered by FVIIa/TF. The ex vivo addition of emicizumab to whole blood from three patients with severe FXI deficiency demonstrated modest, dose-dependent improvements in Ca2+ -triggered thromboelastograms (NATEM mode). Conclusion Emicizumab appeared to improve coagulation function in severe FXI-deficient plasma, and might provide possibilities for clinical application in patients with FXI deficiency.

Rationale and Design of the STOP-OB Study for Evaluating the Effects of Tofogliflozin and Glimepiride on Fat Deposition in Type 2 Diabetes Patients Treated with Metformin/DPP-4 Inhibitor Dual Therapy

BACKGROUND

The global pandemic of type 2 diabetes mellitus (T2DM) is an enormous clinical and socioeconomic burden. Biguanides and DPP-4 inhibitors (DPP-4i) are the most commonly used therapies in Japanese T2DM patients. When glycemic control is not adequate despite combination of these drugs, there is no consensus on the next step drug. Systematic reviews and meta-analyses of previous trials have indicated that glycemic control with triple combination therapies yields similar results. Thus, beneficial effects on cardiovascular risk factors may be important. The present study was designed to evaluate body fat percentage and several insulin resistance parameters after addition of tofogliflozin or glimepiride to the regimens of patients being treated with metformin and a DPP-4 inhibitor but failing to attain adequate blood glucose control.

METHODS

Sodium glucose cotransporter-2 inhibitor, tofogliflozin versus glimepiride, comparative trial in patients with type 2 diabetes on body composition is an ongoing, multicenter, prospective, randomized, open-label, parallel-group trial. T2DM patients treated with metformin/DPP-4 inhibitor dual therapy have been recruited and randomly assigned to 20 mg/day tofogliflozin (n = 32) or 0.5 mg/day glimepiride (n = 32) groups, with either of these drugs being added to pre-existing regimens for 24 weeks.

PLANNED OUTCOMES

The primary endpoint is the change in body fat percentage from baseline to 24 weeks. The secondary outcomes are changes in body composition other than fat percentage, body weight, parameters related to glycemic control and β-cell function, parameters related to lipids and arteriosclerosis, parameters related to liver function, parameters related to diabetic nephropathy, and uric acid levels. Safety parameters will also be analyzed. This is the first trial comparing the effects and safety of adding an SGLT2i and a sulfonylurea as the third-line oral agent to metformin/DPP-4i dual therapy. The results will provide valuable information for choosing third-line oral agents.

TRIAL REGISTRATION

UMIN000026161.

FUNDING

Kowa Co. Ltd. and Kowa Pharmaceutical Co. Ltd., Tokyo, Japan.

Routine measurements of factor VIII activity and inhibitor titer in the presence of emicizumab utilizing anti-idiotype monoclonal antibodies

Essentials Emicizumab (Emi) affects the APTT-based assays of factor (F)VIII activity and inhibitor titer. A mixture of two anti-Emi monoclonal antibodies (mAb) effectively neutralized the Emi activity. Anti-Emi mAbs completely eliminated the influence of Emi on FVIII activity and inhibitor titer. The inclusion of anti-Emi mAbs in routine FVIII assays would be useful for Emi-treated patients.

SUMMARY

Background Emicizumab is an anti-factor (F)IXa/X bispecific monoclonal antibody (mAb), mimicking the factor (F)VIIIa cofactor activity. Emicizumab does not require activation by thrombin and its shortening effect on the activated partial prothrombin time (APTT) is more pronounced than that of factor (F)VIII. APTT-based FVIII activity (FVIII:C) and FVIII inhibiter titer measurements are influenced by the presence of emicizumab. Aim To establish a reliable APTT-based assay to measure FVIII in the presence of emicizumab. Methods Plasmas from hemophilia A (HA) patients without or with inhibitors were studied using one-stage FVIII:C and Bethesda inhibitor assays. Two recombinant anti-idiotype mAbs to emicizumab (anti-emicizumab mAbs) were prepared, rcAQ8 to anti-FIXa-Fab and rcAJ540 to anti-FX-Fab. Results The combined anti-idiotype mAbs (2000 nm each) eliminated the effects of emicizumab on APTTs of HA plasmas without or with inhibitor by competitive inhibition of antibody binding to FIX(a)/FX(a). Measurements of FVIII coagulation activity in HA plasmas without inhibitor were overestimated in the presence of emicizumab (1 μm = ~150 μg mL-1 ) at all reference levels of FVIII. The addition of anti-emicizumab mAbs to the assay mixtures completely neutralized the emicizumab and facilitated accurate determination of FVIII:C. Anti-FVIII inhibitor titers were undetectable in the presence of emicizumab in HA plasmas with inhibitor or normal plasmas mixed with anti-FVIII neutralizing antibodies. These effects of emicizumab were completely counteracted by the addition of the anti-idiotype mAbs, allowing accurate assessment of inhibitor titers. Conclusion The in vitro inclusion of anti-emicizumab mAbs in the standard one-stage coagulation assays prevented interference by emicizumab and enabled accurate measurements of FVIII:C and inhibitor titers.

Modified clot waveform analysis to measure plasma coagulation potential in the presence of the anti-factor IXa/factor X bispecific antibody emicizumab

Essentials The activated partial prothrombin time (aPTT) cannot predict the activity of emicizumab (Emi). Adjusted clot waveform analyses using a prothrombin time (PT)/aPTT initiator were developed. Activity of Emi in the co-presence of factor VIII or bypassing agents was quantified. This assay is useful for assessing coagulation potential in Emi-treated hemophilia A.

SUMMARY

Background Emicizumab is an anti-activated factor IX/FX bispecific antibody that mimics activated FVIII cofactor function. Emicizumab does not require activation by thrombin, and its effect on shortening the activated partial thromboplastin time (APTT) is much greater than that of FVIII. Therefore, the APTT has limited utility in hemophilia A (HA) patients treated with emicizumab. Aim To evaluate the global coagulation potential of emicizumab. Methods Clot waveform analysis (CWA) with prothrombin time (PT)/APTT mixed reagents was used to define hemostatic monitoring protocols in HA patients. A modified parameter, adjusted-|min1| (Ad|min1|), was developed. Maximum and minimum percentage transmittance were defined as 100% and 0% in the precoagulation and postcoagulation phases, respectively. Ad|min1| was calculated as an index of the maximum velocity of the coagulation process. Results Ad|min1| obtained with mixed-trigger reagent (PT/APTT/buffer, 1 : 15 : 135) in the presence of emicizumab optimally corresponded to the conversion rate estimated in animals; 0.2-0.4 IU dL-1 equivalent FVIII per 1 μg mL-1 emicizumab). Ex vivo addition of emicizumab to HA plasma with or without inhibitors resulted in concentration-dependent increases in Ad|min1|, with some individual variations. The addition of various concentrations of FVIII to HA plasma mixed with emicizumab resulted in dose-dependent increases in Ad|min1|. Similarly, mixtures of activated prothrombin complex concentrate and emicizumab added to HA plasma resulted in dose-dependent increases in Ad|min1|. In contrast, enhanced coagulation potential appeared to be better defined by the clot time than by Ad|min1| in experiments using recombinant activated FVII. Conclusion The PT/APTT reagent-triggered adjusted CWA could provide a useful means of assessing global coagulation potential in emicizumab-treated HA patients, with enhanced activity neither masking nor being masked by FVIII or bypassing agents.

Catheter-related bloodstream infection due to Rhodotorula mucilaginosa with normal serum (1→3)-β-D-glucan level

Rhodotorula species are environmental basidiomycete yeasts that have emerged as a cause of fungemia in immunocompromised hosts. The insertion of a central venous catheter was identified as a major risk factor for Rhodotorula fungemia. Few cases reports have reported (1→3)-β-D-glucan testing at the onset of Rhodotorula mucilaginosa fungemia. We report a case of catheter-related bloodstream infection due to R. mucilaginosa. Serum β-D-glucan level was normal at the onset of the bloodstream infection. It took 5 days to culture the isolate. The patient's fever persisted after empiric treatment with micafungin, and a switch to oral voriconazole immediately resolved the fungemia.

Neuropeptide Y (NPY) inhibits spontaneous contraction of the mouse atrium by possible activation of the NPY1 receptor

Neuropeptide Y (NPY) causes various central and peripheral actions through activation of G-protein-coupled NPY receptors. Although a species-dependent difference in cardiac actions of NPY has been reported, the responses to NPY have not been examined in mice, widely used experimental animals. This study aimed to clarify the responses to NPY and the receptor subtype involved in the responses in mouse atrium. Neuropeptide Y caused negative inotropic and negative chronotropic actions in spontaneous beating right atria. Negative inotropic actions were more marked than negative chronotropic actions. Therefore, negative inotropic actions were studied in detail for evaluation of the NPY-induced cardiac actions in mouse atrium. Neuropeptide Y-induced negative inotropic actions were not affected by atropine but were abolished in the atria from pertussis toxin-treated mice. In isolated atrial preparations from reserpine-treated mice, NPY-induced negative inotropic actions were significantly attenuated. [Leu31, Pro34]-NPY, but not peptide YY, was effective in decreasing spontaneous contraction in atrial preparations. Although Y₁ , Y₂ , Y₄ and Y₅ receptor mRNAs were expressed almost equally in the brain, NPY₁ receptor mRNA was dominantly expressed in the atrium. In conclusion, NPY caused negative inotropic and chronotropic actions through activation of the Y₁ receptor in the mouse atrium. A high expression level of Y₁ mRNA in the atrium suggests a functional role of NPY in the regulation of mouse cardiac contraction.

Combination therapy of glucagon-like peptide-1 receptor agonists and insulin for patients who developed diabetes after partial pancreatectomy

Aims/Introduction

It is known that after pancreatectomy, patients experience hyposecretion of endogenous insulin and frequently develop diabetes. However, it has been unclear whether combination therapy with glucagon‐like peptide‐1 receptor agonists and basal insulin is effective for such patients. In the present study, we evaluated the efficacy and safety of combination therapy with long‐acting insulin glargine and the glucagon‐like peptide‐1 receptor agonist lixisenatide in patients who developed diabetes after pancreatectomy.

Materials and Methods

Japanese patients who developed diabetes after pancreatectomy were eligible for this study. Participants were treated with combination therapy of glargine and lixisenatide for 12 weeks. Fasting and postprandial plasma glucose, C‐peptide immunoreactivity, glycated hemoglobin, bodyweight, visceral fat and subcutaneous fat were measured.

Results

At 12 weeks after initiation of lixisenatide, glycated hemoglobin levels decreased from 8.46 ± 1.64% to 6.81 ± 1.15%. In addition, 1‐h postprandial plasma glucose and 2‐h postprandial plasma glucose levels significantly decreased from 222.9 ± 56.2 mg/dL to 125.1 ± 37.5 mg/dL (P < 0.001) and from 247.5 ± 56.8 mg/dL to 115.1 ± 29.0 mg/dL (P < 0.001), respectively. Neither hypoglycemia nor clinically relevant adverse events occurred during this study.

Conclusions

The present study shows that combination therapy with basal insulin and glucagon‐like peptide‐1 receptor agonists after partial pancreatectomy can be a useful therapeutic option for providing effective glycemic control with a reduced risk of hypoglycemia.

Anti-factor IXa/X bispecific antibody (ACE910): hemostatic potency against ongoing bleeds in a hemophilia A model and the possibility of routine supplementation

BACKGROUND

We previously reported that a humanized anti-factor IXa/X bispecific antibody, hBS23, mimics the function of FVIII even in the presence of FVIII inhibitors, and has preventive hemostatic activity against bleeding in an animal model of acquired hemophilia A. After further molecular engineering of hBS23, we recently identified an improved humanized bispecific antibody, ACE910, for clinical investigation.

OBJECTIVES

To elucidate the in vivo hemostatic potency of ACE910 by examining its effect against ongoing bleeds, and to determine its pharmacokinetic parameters for discussion of its potency for prophylactic use.

METHODS

A non-human primate model of acquired hemophilia A was established by injecting anti-primate FVIII neutralizing antibody. When bleeds emerged following an artificial bleed-inducing procedure, either ACE910 or recombinant porcine FVIII (rpoFVIII) was intravenously administered. rpoFVIII was additionally administered twice daily on the following 2 days. Bleeding symptoms were monitored for 3 days. A pharmacokinetic study and multiple-dosing simulations of ACE910 were also performed.

RESULTS

A single bolus of 1 or 3 mg kg-1 ACE910 showed hemostatic activity comparable to that of 10 U kg-1 (twice daily) rpoFVIII against ongoing bleeds. The determined ACE910 pharmacokinetic parameters included a long half-life (3 weeks) and high subcutaneous bioavailability (nearly 100%). The simulation results based on pharmacokinetic parameters indicated that the above hemostatic level could be maintained with once-weekly subcutaneous administration of ACE910, suggesting the possibility of more effective prophylaxis.

CONCLUSIONS

ACE910 may offer an alternative on-demand treatment option for patients with hemophilia A, as well as user-friendly and aggressive routine supplementation.

Anti-factor IXa/X bispecific antibody (ACE910): hemostatic potency against ongoing bleeds in a hemophilia A model and the possibility of routine supplementation

BACKGROUND

We previously reported that a humanized anti-factor IXa/X bispecific antibody, hBS23, mimics the function of FVIII even in the presence of FVIII inhibitors, and has preventive hemostatic activity against bleeding in an animal model of acquired hemophilia A. After further molecular engineering of hBS23, we recently identified an improved humanized bispecific antibody, ACE910, for clinical investigation.

OBJECTIVES

To elucidate the in vivo hemostatic potency of ACE910 by examining its effect against ongoing bleeds, and to determine its pharmacokinetic parameters for discussion of its potency for prophylactic use.

METHODS

A nonhuman primate model of acquired hemophilia A was established by injecting anti-primate FVIII neutralizing antibody. When bleeds emerged following an artificial bleed-inducing procedure, either ACE910 or recombinant porcine FVIII (rpoFVIII) was intravenously administered. rpoFVIII was additionally administered twice daily on the following 2 days. Bleeding symptoms were monitored for 3 days. A pharmacokinetic study and multiple-dosing simulations of ACE910 were also performed.

RESULTS

A single bolus of 1 or 3 mg kg⁻¹ ACE910 showed hemostatic activity comparable to that of 10 U kg⁻¹ (twice daily) rpoFVIII against ongoing bleeds. The determined ACE910 pharmacokinetic parameters included a long half-life (3 weeks) and high subcutaneous bioavailability (nearly 100%). The simulation results based on pharmacokinetic parameters indicated that the above hemostatic level could be maintained with once-weekly subcutaneous administration of ACE910, suggesting the possibility of more effective prophylaxis.

CONCLUSIONS

ACE910 may offer an alternative on-demand treatment option for patients with hemophilia A, as well as user-friendly and aggressive routine supplementation.

RESEARCH (Recognized effect of Statin and ezetimibe therapy for achieving LDL-C Goal), a randomized, doctor-oriented, multicenter trial to compare the effects of higher-dose statin versus ezetimibe-plus-statin on the serum LDL-C concentration of Japanese type-2 diabetes patients design and rationale

Aims

Hypercholesterolemia coexisting with diabetes still requires clinical intervention to manage the high risk of cardiovascular disease it poses. No second-step strategy is established, however, for cases where strong statins fail to bring cholesterol down to target levels. In this study we seek to demonstrate the superior effect of ezetimibe in combination with strong statins to reduce LDL-C in Japanese patients suffering from both T2DM and hyper LDL-cholesterolemia.

Methods

T2DM outpatients (109 patients from 16 institutes) who failed to achieve the target LDL-C value were recruited and randomly assigned to two groups, a double-dose-statin group and ezetimibe-plus-statin group. Follow-ups were scheduled at 0, 12, 26, and 52 weeks. The primary endpoint was the percentage change in the level of LDL-C from baseline to 12 weeks.

Interim results

We could successfully create randomized (gender, age, LDL-C, HbA1c, etc.) two groups except for slight differences in apolipoprotein-B and sd-LDL.

Conclusions

RESEARCH is the first prospective, parallel-group, multicenter study comparing a double dose of strong statin with ezetimibe plus strong statin for T2DM patients. The RESEARCH study will provide reliable evidence with which to establish a clinical strategy for diabetics who fail to achieve the target LDL-C value.

Roles of M2 and M3 muscarinic receptors in the generation of rhythmic motor activity in mouse small intestine

BACKGROUND

The roles of M2 and M3 muscarinic receptor subtypes in the regulation of gut motor activity were investigated.

METHODS

We simultaneously recorded changes in the intraluminal pressure (IP) and longitudinal tension (LT) in small intestinal segments from M2 or M3 receptor knockout (KO) and wild-type (WT) mice.

KEY RESULTS

In the WT preparations, luminal distension induced a continuous rhythmic contractile activity that was characterized by synchronous rises in IP and LT, occurring periodically at a constant interval. Tetrodotoxin completely abolished the response, whereas atropine either abolished or attenuated it. In the majority of the M2 KO preparations, however, no rhythmic activity was observed in response to the luminal distention, even though networks of enteric neurons and interstitial cells of Cajal (ICC) seemed to be intact. Where rhythmic activity did occur in M2 KO preparations, it was atropine resistant. In the M3 KO preparations, the IP and LT were synchronously changed by the luminal distention, but the changes occurred at irregular intervals. The W/W(v) mutant preparations, which lack ICC in the myenteric plexus (ICC-MY), showed results similar to those of the M3 KO preparations. In some of the M2 /M3 double-KO preparations, rhythmic activity was not observed, but in the others, an atropine-resistant rhythmicity appeared.

CONCLUSIONS & INFERENCES

These results suggest that M2 and M3 muscarinic receptors differentially regulate the intestinal motor activity: M2 receptors play an essential role in the generation of rhythmic motor activity, and M3 receptors have a modulatory role in controlling the periodicity of the rhythmic activity together with the ICC-MY.

Comparison between sitagliptin and nateglinide on postprandial lipid levels: The STANDARD study

AIM: To assess the effects of sitagliptin and nateglinide on lipid metabolism.

METHODS: In a parallel group comparative open trial, patients with type 2 diabetes mellitus under treatment at the Japanese Red Cross Medical Center were randomly assigned to receive either sitagliptin (50 mg once daily) or nateglinide (90 mg three times daily before meals). Eligible patients met the following criteria: age ≥ 20 years; hemoglobin A_1c (HbA_1c) > 6.5% despite diet and exercise; HbA_1c between 6.5% and 8.0%; fasting glucose < 7.77 mmol/L; diet and exercise therapy for more than 3 mo; and ability to read and understand the information for written informed consent. Exclusion criteria were contraindications to sitagliptin, contraindications to nateglinide, pregnancy or possible pregnancy, and severe liver/renal failure. Patients who were considered to be unsuitable by the attending physician for other reasons were also excluded. Blood samples were collected at one and three hours after intake of a test meal. The primary outcome measure was the area under the curve (AUC) of apolipoprotein (Apo) B48 at three hours postprandially.

RESULTS: Twenty patients were randomly assigned to the sitagliptin group and sixteen patients were randomized to the nateglinide group. All 36 patients took the medication as directed by the physician in both groups, and they all were analyzed. Apart from antidiabetic drugs, there was no difference between the two groups with respect to the frequency of combined use of lipid-lowering, antihypertensive, and/or antiplatelet drugs. The doses of these medications were maintained during 12 wk of treatment. Detailed dietary advice, together with adequate exercise therapy, was given to the patients so that other factors apart from the two test drugs were similar in the two groups. There were no significant differences of the baseline characteristics between the two groups, except for body mass index (the sitagliptin group: 25.14 ± 3.05 kg/m²; the nateglinide group: 21.39 ± 2.24 kg/m²). Fasting levels of HbA_1c, glycated albumin, 1.5-anhydroglucitol, and blood glucose, as well as the blood glucose levels at one and three hours postprandially, improved in both groups after 12 wk of treatment, and there were no significant differences between the two groups. However, the glucagon level at one hour postprandially (P = 0.040) and the diastolic blood pressure (P < 0.01) only showed a significant decrease in the sitagliptin group. In the nateglinide group, there was no significant change in the AUC of Apo B48, the glucagon level at one hour postprandially, the fasting triglyceride level, or the diastolic blood pressure. Body weight was unchanged in both groups. However, the AUC of Apo B48 at three hours postprandially showed a significant decrease in the sitagliptin group from 2.48 ± 0.11 at baseline to 1.94 ± 0.78 g/L per hour after 12 wk (P = 0.019). The fasting triglyceride level also decreased significantly in the sitagliptin group (P = 0.035). With regard to lipid-related markers other than Apo B48 and fasting triglycerides, no significant changes were observed with respect to Apo A1, Apo B, or Apo C3 in either group. No adverse events occurred in either group.

CONCLUSION: Sitagliptin significantly improves some lipid parameters while having a comparable effect on blood glucose to nateglinide. A large-scale prospective study of sitagliptin therapy is warranted.

Colon-specific contractile responses to tetrodotoxin in the isolated mouse gastrointestinal tract

1 Tetrodotoxin (TTX) is a useful pharmacological tool for distinguishing neural and myogenic responses of isolated visceral organs to drugs. Although TTX does not generally affect smooth muscle tonus, in this study, we have found that TTX causes contraction of the mouse colon. The aim of this study was to characterize this TTX-induced contraction in the mouse gastrointestinal tract. 2 Longitudinal and circular muscle strips from the stomach and small intestine were less sensitive to TTX. However, TTX contracted both smooth muscle strips from the proximal colon and distal colon. 3 Pretreatment with TTX, Nω -nitro-L-arginine methyl ester (L-NAME), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and apamin inhibited the TTX-induced contraction. L-NAME, ODQ or apamin itself caused contraction in the colon but not in the gastric and small intestinal strips. Region dependency of L-NAME, ODQ and apamin-induced contraction correlated with that of TTX-induced contraction. 4 L-arginine but not D-arginine inhibited contractility of the colonic strips without affecting the contractility of muscle strips from other regions. Sodium nitroprusside caused strong relaxation of the colonic strips. 5 1,1-dimethyl-4-phenylpiperazinium (DMPP) caused relaxation of proximal and distal colons, which was significantly decreased by L-NAME or apamin. 6 In conclusion, among mouse gastrointestinal preparations, TTX induces contraction of colonic strips preferentially through blockade of potent tonic inhibitory neural outflow, which involves nitrergic and apamin-sensitive pathways. Colon-specific responses to L-arginine, L-NAME, ODQ and apamin support the hypothesis that there is a continuous suppression of colonic motility by enteric inhibitory neurons.

Ghrelin stimulates gastric motility of the guinea pig through activation of a capsaicin-sensitive neural pathway: in vivo and in vitro functional studies

BACKGROUND

Ghrelin stimulates gastric motility in rats, mice and humans. Although ghrelin and the ghrelin receptor are known to be expressed in the guinea-pig gastrointestinal tract, the effects of ghrelin on gastric motility have not been examined. Aim of the present study was to clarify the motor-stimulating action of ghrelin in the guinea-pig stomach.

METHODS

Gastric motility was measured as intraluminal pressure changes using a balloon inserted in the stomach of urethane-anaesthetized guinea pigs. The effects of ghrelin on gastric muscle contraction and [(3)H]-efflux from [(3)H]-choline-loaded strips were investigated in vitro.

KEY RESULTS

Ghrelin (0.3-30 microg kg(-1), i.v.) increased gastric motility in a dose-dependent manner but des-acyl ghrelin was ineffective. The action of ghrelin was completely inhibited by hexamethonium and D-Lys(3)-growth-hormone releasing peptide-6. Atropine partially decreased the stimulatory action of ghrelin. In capsaicin-pretreated guinea pigs, the ghrelin-induced response was markedly decreased. Ghrelin (1 micromol L(-1)) did not affect [(3)H]-efflux in non-stimulated preparations but significantly decreased electrical field stimulation (EFS)-induced [(3)H]-efflux. L-Nitro arginine methylester (L-NAME) attenuated the inhibition of [(3)H]-efflux by ghrelin. Ghrelin did not cause any mechanical changes in gastric strips. Electrical field stimulation caused relaxation of gastric strips, which changed to atropine-sensitive contraction in the presence of L-NAME. Relaxation induced by EFS was slightly potentiated, but the EFS-induced contraction was not affected by ghrelin.

CONCLUSIONS & INFERENCES

Ghrelin stimulates gastric motility of the guinea pig through activation of capsaicin-sensitive vago-vagal reflex pathway including efferent cholinergic neurons. Peripheral ghrelin receptors on enteric nitrergic nerves might affect the ghrelin-induced gastric action by releasing nitric oxide.

Pharmacological characterization of 5-hydroxytryptamine-induced contraction in the chicken gastrointestinal tract

5-Hydroxytryptamine (5-HT) receptor subtypes involved in 5-HT-induced contraction of the chicken gastrointestinal tract were characterized pharmacologically using subtype-selective agonists and antagonists. The proventriculus (area of stomach adjacent to the oesophagus) and ileum are examined. 5-HT applied cumulatively caused sustained contraction of the proventriculus that was not decreased by tetrodotoxin, atropine or l-nitro-arginine methylester (l-NAME). alpha-Methyl-5-HT showed the same potency as that of 5-HT, indicating the involvement of the 5-HT(2) receptor. (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-amino-propane (DOI), 5-methoxytryptamine and 1-(3-chlorophenyl)piperazine hydrochloride (mCPP) were potent, and 2-methyl-5-HT, 5-carboxamidotryptamine, BW723C86 and 6-chloro-2-(1-piperazinyl)pyrazine hydrochloride (MK212) were moderate, but (+/-)-8-hydroxy-2-dipropylaminotetralin hydrobromide (8-OH-DPAT), [endo-N-8-methyl-8-azabicyclo-(3,2,1)oct-3-yl]-2,3-dihydro-(1-methyl)ethyl-2-oxo-1H-benzimidazol-1-carboxamide (BIMU-8) and cisapride were weak agonists. Correlation of pEC(50) values of these agonists with documented pEC(50) values for 5-HT(2C) receptor was higher than 5-HT(2A) and 5-HT(2B). Cinanserin, ketanserin, methiothepin, methysergide, mianserin, (8-[5-(2,4-dimethoxy-5-(4-trifluoromethylphenylsulphonamido)phenyl-5-oxopentyl)-1,3,8-triazaspiro[4,5]decane-2,4-dione hydrochloride (RS102221), N-(1-methyl-1H-indolyl-5-yl)-N'-(3-methyl-5-isothiazolyl)urea (SB204741), spiperone and N-desmethylclozapine concentration-dependently inhibited the contractile responses to 5-HT. Correlation of pK(b)/pA(2) of antagonists with documented pK(i) for 5-HT(2C) receptor was highest among 5-HT(2) receptor subtypes. In the methysergide- and ketanserin-treated proventriculus, 5-HT, 2-methyl-5-HT and cisapride did not enhance the electrical field stimulation (5 Hz)-induced cholinergic contractions. 5-HT applied non-cumulatively caused transient contraction of ileum, and the responses were partly decreased by atropine or tetrodotoxin. 5-Methoxytryptamine, alpha-methyl-5-HT, 5-carboxamidotryptamine, L692,247 and DOI were potent agonists. However, 2-methyl-5-HT, cisapride, BW723C86, 8-OH-DPAT and 5-nonyloxytryptamine, mCPP and MK212 were less effective. Ketanserin and methysergide decreased the 5-HT-induced ileal contraction, but neither GR113808 nor SB269970 inhibited the responses. In conclusion, 5-HT causes contraction of the proventriculus via 5-HT(2C)-like receptors present on smooth muscle. 5-HT also causes contraction of the ileum, but the underlying mechanisms are complex, involving neural and smooth muscle components, and both 5-HT(1)- and 5-HT(2)-like receptors. Neural 5-HT receptors similar to 5-HT(3)/5-HT(4) receptors were not found in the chicken proventriculus and ileum.

A new method for detecting the abomasal position and characteristics of movement at the onset of the left displacement of the abomasum in cows

A new method has been developed by us to observe the movements of the abomasum by using a magnet and digital magnetometer. Four cows with left displacement of the abomasum underwent conventional correction by rolling without tacking. A doughnut-type magnet was sutured to the pyloric region in a routine operation. The same was done in three control cows. The position of the pyloric region was observed with a digital magnetometer from outside the cow's body. The magnets in the pyloric region of the control cows were located at the right side of the abdominal cavity at 10-30 cm anterior to the udder base, and moved slightly in various directions within the span of a day. On the other hand, the magnets in the pyloric region of cows with abomasal displacement moved widely in the abdominal cavity from the normal right side to the abnormal left front side. A large movement of the magnet from the normal right side to the abnormal left side of the abdominal cavity was observed within 12 h of the onset of abomasal displacement.

Factor XI contributes to thrombus propagation on injured neointima of the rabbit iliac artery

BACKGROUND

Thrombus formation through the activation of tissue factor (TF) and factor (F) XI is a critical event in the onset of cardiovascular disease. TF expressed in atherosclerotic plaques and circulating blood is an important determinant of thrombogenicity that contributes to fibrin-rich thrombus formation after plaque disruption. However, the contribution of FXI to thrombus formation on disrupted plaques remains unclear.

METHODS

A mouse monoclonal antibody against FXI and activated FXI (FXIa) (XI-5108) was generated by immunization with activated human FXI. Prothrombin time (PT), activated partial thromboplastin time (APTT), bleeding time, and ex vivo platelet aggregation in rabbits were measured before and after an intravenous bolus injection of XI-5108. We investigated the role of FXI upon arterial thrombus growth in the rabbit iliac artery in the presence of repeated balloon injury.

RESULTS

The XI-5108 antibody reacted to the light chain of human and rabbit FXI/FXIa, and inhibited FXIa-initiated FXa and FXIa generation. Fibrin-rich thrombi developed on the injured neointima that was obviously immunopositive for glycoprotein IIb-IIIa, fibrin, TF, and FXI. Intravenous administration of XI-5108 (3.0 mg kg(-1)) remarkably reduced thrombus growth, and the APTT was significantly prolonged. However, PT, bleeding time and platelet aggregation were not affected.

CONCLUSIONS

These results indicate that plasma FXI plays a potent role in thrombus growth on the injured neointima. Inhibition of plasma FXI activity might help to reduce thrombus growth on ruptured plaques without prolonging bleeding time.

Gastric motor effects of peptide and non-peptide ghrelin agonists in mice in vivo and in vitro

BACKGROUND AND AIMS

The gastroprokinetic activities of ghrelin, the natural ligand of the growth hormone secretagogue receptor (GHS-R), prompted us to compare the effect of ghrelin with that of synthetic peptide (growth hormone releasing peptide 6 (GHRP-6)) and non-peptide (capromorelin) GHS-R agonists both in vivo and in vitro.

METHODS

In vivo, the dose dependent effects (1-150 nmol/kg) of ghrelin, GHRP-6, and capromorelin on gastric emptying were measured by the 14C octanoic breath test which was adapted for use in mice. The effect of atropine, N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME), or D-Lys3-GHRP-6 (GHS-R antagonist) on the gastroprokinetic effect of capromorelin was also investigated. In vitro, the effect of the GHS-R agonists (1 microM) on electrical field stimulation (EFS) induced responses was studied in fundic strips in the absence and presence of L-NAME.

RESULTS

Ghrelin, GHRP-6, and capromorelin accelerated gastric emptying in an equipotent manner, with bell-shaped dose-response relationships. In the presence of atropine or l-NAME, which delayed gastric emptying, capromorelin failed to accelerate gastric emptying. D-Lys3-GHRP-6 also delayed gastric emptying but did not effectively block the action of the GHS-R agonists, but this may be related to interactions with other receptors. EFS of fundic strips caused frequency dependent relaxations that were not modified by the GHS-R agonists. L-NAME turned EFS induced relaxations into cholinergic contractions that were enhanced by ghrelin, GHRP-6, and capromorelin.

CONCLUSION

The 14C octanoic breath test is a valuable technique to evaluate drug induced effects on gastric emptying in mice. Peptide and non-peptide GHS-R agonists accelerate gastric emptying of solids in an equipotent manner through activation of GHS receptors, possibly located on local cholinergic enteric nerves.

Classification of abomasal displacement in cows according to histopathology of the liver and clinical chemistry

Histopathological features of livers and blood chemical values in cows with abomasal displacement were investigated. Liver biopsy samples were collected during redressment operations in 92 cows with abomasal displacement, and the samples were stained with haematoxylin and eosin or periodic acid Schiff (PAS). Blood was collected for chemical tests. Livers were histopathologically divided into the following four types: normal histology cases (21%), fatty degeneration cases (36%), cloudy swelling cases (19%) and fatty degeneration cases with cloudy swelling (24%). The number of PAS-positive samples was significantly higher in the normal histology group and significantly lower in the severe fatty degeneration group and severe cloudy swelling group. Cows with fatty degeneration had significantly higher levels of serum 3-hydroxybutyric acid, non-esterified fatty acid and aspartate aminotransferase than did those with cloudy swelling or normal histology. The results indicate that the morbid conditions of cows with abomasal displacement can be classified into four types.

False positive uptake of metaiodobenzylguanidine in hepatocellular carcinoma

We present the case of a patient who showed increased accumulation of (123)I-metaiodobenzylguanidine (MIBG) in hepatocellular carcinoma, leading to a false presumptive diagnosis of intrahepatic neuroendocrine tumour. The increase in uptake was not seen on images obtained 4 h after tracer injection but was evident on those taken after 24 h, suggesting slower washout from the liver tumour than from non-tumoural liver parenchyma. Our observations indicate that a non-neuroendocrine malignant tumour may exhibit high accumulation of MIBG associated with prolonged retention.

Potentiation of motilin-induced contraction by nitric oxide synthase inhibition in the isolated chicken gastrointestinal tract

The present experiments were designed to determine whether or not endogenous nitric oxide (NO) modifies the contractile response to chicken motilin (ch-MT) in the gastrointestinal (GI) tract (proventriculus and small intestine) of the chicken. ch-MT (1 nmol L(-1)-1 micromol L(-1)) caused contractions of longitudinal muscle strips of the proventriculus through both myogenic and neurogenic (mostly cholinergic) mechanisms. On the other hand, ch-MT (0.1 nmol L(-1)-100 nmol L(-1)) contracted the small intestine (duodenum, jejunum and ileum) only through a myogenic mechanism. L-Nitroarginine methylester (L-NAME) potentiated, and L-arginine inhibited, the ch-MT- induced contraction without affecting the responsiveness of acetylcholine (ACh) or 5-hydroxytryptamine in the proventriculus. Electrical field stimulation (EFS)- and 1,1-dimethyl-4-phenylpiperazinium (DMPP)- induced contractions were also potentiated by L-NAME. The potentiation by L-NAME was prevented by L-arginine but not by D-arginine. However, in the presence of atropine or tetrodotoxin, neither L-NAME nor L-arginine modified the responses to ch-MT and DMPP. In contrast to the proventriculus, L-NAME and L-arginine were both ineffective in modifying the ch-MT-induced contraction in the small intestine. These results indicate that NO synthase inhibition potentiates the contractile response of ch-MT, EFS and DMPP in the chicken proventriculus through reduction of endogenous NO-mediated presynaptic inhibition on neural ACh release. However, NOS inhibition did not modify the myogenic (direct) action of ch-MT in gastric and intestinal smooth muscles of the chicken.

5-HT(7) receptor and beta(2)-adrenoceptor share in the inhibition of porcine uterine contractility in a muscle layer-dependent manner

To compare the inhibition of uterine contractility mediated by beta-adrenoceptors and 5-HT(7) receptors, the effects of catecholamines and 5-HT on spontaneous contractions were examined in longitudinal and circular muscles isolated from three different regions (cornu, corpus and cervix) of the non-pregnant proestrus porcine uterus. In addition, the distribution of beta-adrenoceptors between muscle layers was characterized by means of adenylate cyclase activity assay, cyclic AMP assay and [(3)H]dihydroalprenolol binding studies. In the cornu, isoprenaline, adrenaline and noradrenaline inhibited the spontaneous contraction of longitudinal and circular muscles but longitudinal muscle was more sensitive to catecholamines than was circular muscle. The inhibitory response to isoprenaline was antagonized by propranolol (300 nM) or (+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol (ICI 118,551; 100 nM). The rank order of potency was isoprenaline > or =adrenaline > noradrenaline. The beta(2)-adrenoceptor-selective agonist, clenbuterol, was more potent than xamoterol (beta(1)-selective) and (+/-)-4-[2-[(2-(3-chlorophenyl)-2-hydroxyethyl)amino]propyl]phenoxyacetic acid (BRL 37344; beta(3)-selective) to inhibit the spontaneous contraction of longitudinal muscles. Isoprenaline increased adenylate cyclase activity in both muscle layers, but the activity in the longitudinal muscle was greater than that in the circular muscle. Cyclic AMP production by isoprenaline was also more conspicuous in the longitudinal muscle than in the circular muscle. Although both muscle layers contained a single class of [3H]dihydroalprenolol binding sites with similar K(d) values (longitudinal muscle, 3.1+/-0.94 nM, n=4; circular muscle, 2.4+/-0.73 nM, n=4), B(max) in the longitudinal muscle (175.7+/-32.8 fmol/mg protein, n=4) was significantly higher than that in the circular muscle (53.1+/-5.1 fmol/mg protein, n=4). As previously reported [Br. J. Pharmacol. 130 (2000) 79], 5-HT also inhibited the spontaneous contraction of both muscle layers from the cornu and the 5-HT(7) receptor antagonist, 2a-[4-(4-phenyl-1,2,3,6-tetrahydropyridyl)butyl]-2a,3,4,5-tetrahydro-benzo[cd]indol-2(1H)-one (DR4004; 100 nM, n=4) blocked the 5-HT-induced inhibition of spontaneous contractions in the circular muscles, and reversed the less marked inhibition in the longitudinal muscles. In other regions of the uterus (corpus and cervix), 5-HT inhibited the spontaneous contraction of the circular muscles but contracted the longitudinal muscle strips. On the other hand, isoprenaline caused muscle layer-dependent inhibition (longitudinal muscle > circular muscle) in both regions, and the responsiveness tended to increase toward the cervix. In conclusion, beta(2)-adrenoceptors are present heterogeneously in the porcine uterus (longitudinal muscle > circular muscle) and share the inhibition of uterine contractility with 5-HT(7) receptors in a layer-dependent manner (longitudinal muscle: beta(2)-adrenoceptors, circular muscle: 5-HT(7) receptors).

Expression of CPI-17 and myosin phosphatase correlates with Ca(2+) sensitivity of protein kinase C-induced contraction in rabbit smooth muscle

1. Various smooth muscles have unique contractile characteristics, such as the degree of Ca(2+) sensitivity induced by physiological and pharmacological agents. Here we evaluated six different rabbit smooth muscle tissues for protein kinase C (PKC)-induced Ca(2+) sensitization. We also examined the expression levels of myosin light chain phosphatase (MLCP), the MLCP inhibitor phosphoprotein CPI-17, and the thin filament regulator h-calponin. 2. Immunohistochemical and Western blot analyses indicated that CPI-17 was found primarily in smooth muscle, although expression varied among different tissues. Vascular muscles contained more CPI-17 than visceral muscles, with further distinction existing between tonic and phasic subtypes. For example, the tonic femoral artery possessed approximately 8 times the cellular CPI-17 concentration of the phasic vas deferens. 3. In contrast to CPI-17 expression patterns, phasic muscles contained more MLCP myosin-targeting subunit than tonic tissues. Calponin expression was not statistically different. 4. Addition of phorbol ester to alpha-toxin-permeabilized smooth muscle caused an increase in contraction and phosphorylation of both CPI-17 and myosin light chain (MLC) at submaximal [Ca(2+)]i. These responses were several-fold greater in femoral artery as compared to vas deferens. 5. We conclude that the expression ratio of CPI-17 to MLCP correlates with the Ca(2+) sensitivities of contraction induced by a PKC activator. PKC stimulation of arterial smooth muscle with a high CPI-17 and low MLCP expression generated greater force and MLC phosphorylation than stimulation of visceral muscle with a relatively low CPI-17 and high MLCP content. This implicates CPI-17 inhibition of MLCP as an important component in modulating vascular muscle tone.

Histamine-induced vasoconstriction involves phosphorylation of a specific inhibitor protein for myosin phosphatase by protein kinase C alpha and delta isoforms

Histamine stimulus triggers inhibition of myosin phosphatase-enhanced phosphorylation of myosin and contraction of vascular smooth muscle. In response to histamine stimulation of intact femoral artery, a smooth muscle-specific protein called CPI-17 (for protein kinase C-potentiated inhibitory protein for heterotrimeric myosin light chain phosphatase of 17 kDa) is phosphorylated and converted to a potent inhibitor for myosin phosphatase. Phosphorylation of CPI-17 is diminished by pretreatment with either or GF109203x, suggesting involvement of multiple kinases (Kitazawa, T., Eto, M., Woodsome, T. P., and Brautigan, D. L. (2000) J. Biol. Chem. 275, 9897--9900). Here we purified and identified CPI-17 kinases endogenous to pig artery that phosphorylate CPI-17. DEAE-Toyopearl column chromatography of aorta extracts separated two CPI-17 kinases. One kinase was protein kinase C (PKC) alpha, and the second kinase was purified to homogeneity as a 45-kDa protein, and identified by sequencing as PKC delta. Purified PKC delta was 3-fold more reactive with CPI-17 compared with myelin basic protein, whereas purified PKC alpha and recombinant RhoA-activated kinases (Rho-associated coiled-coil forming protein Ser/Thr kinase and protein kinase N) showed equal activity with CPI-17 and myelin basic protein. inhibited CPI-17 phosphorylation by purified PKC delta with IC(50) of 0.6 microm (in the presence of 0.1 mm ATP) or 14 microm (2.0 mm ATP). significantly suppressed CPI-17 phosphorylation in smooth muscle cells, and the contraction of permeabilized rabbit femoral artery induced by stimulation with phorbol ester. GF109203x inhibited phorbol ester-induced contraction of rabbit femoral artery by 80%, whereas a PKC alpha/beta inhibitor, Go6976, reduced contraction by 47%. The results imply that histamine stimulation elicits contraction of vascular smooth muscle through activation of PKC alpha and especially PKC delta to phosphorylate CPI-17.

Clinical factors of recurrent chronic subdural hematoma

The clinical, radiological, and operative factors of recurrent chronic subdural hematoma (CSDH) were retrospectively analyzed in 116 patients with CSDH in 134 hemispheres, treated by one burr hole surgery. The correlation of recurrence was evaluated with personal and clinical factors such as age, sex, history of head injury, and interval from onset of initial symptoms to hospitalization; laboratory findings such as bleeding tendency and liver function; computed tomography (CT) findings such as hematoma density and brain atrophy; and operative findings such as additional procedures and postoperative residual air. The recurrence group (RG) included 10 hemispheres (7.5%) in 10 patients (8.6%). The interval from onset of symptoms to hospitalization was significantly shorter in the RG than in the nonrecurrence group (NRG). Headache was more frequently seen in the RG than in the NRG. Density of hematoma on CT was classified into five types: Low, iso, and high density, niveau, and mixed, and the incidence of recurrence was 0%, 2.3%, 17.2%, 12.5%, and 6.5%, respectively. Larger amounts of residual air in the postoperative hematoma cavity were associated with recurrence of CSDH. CSDH that progresses rapidly in the acute stage and appears as high density on preoperative CT is associated with a high incidence of recurrence. Intraoperative air invasion to the hematoma cavity should be avoided to prevent recurrence.

[An attempt to estimate geographical accessibility to day service facilities among the elderly with a geographical information system]

OBJECTIVE

The objective of this study was to assess inequality in geographical accessibility to day service among the elderly in a municipality using a geographical information system (GIS). We also examined problems in measuring geographical accessibility and ways to validate results.

METHODS

The target was Hachioji City. The following two data sets were constructed: a data set for day service facilities for all of Hachioji City and a data set for the people aged 65 and over, living within 1 km meshes in Hachioji City. These were integrated and displayed on a digital map with GIS software. Geographical accessibility was estimated by measuring the shortest road distance from the center point of each mesh to day service facilities.

RESULTS

There were 47 day service facilities serving Hachioji City in October, 2000 and 139 meshes that had elderly residents. Their center points were all located within Hachioji City, which was estimated to have 73,760 elderly in 2000. The mean distance from the center point of each mesh to the nearest day service facility was 1.99 km (SD = 1.75, max = 9.21, min = 0.03). The proportions of the elderly who had 5 or more facilities within 3 km and 5 km from their residence were estimated to be 57.3% and 96.4%, respectively.

CONCLUSIONS

The results of this study suggest that there is variation in geographical accessibility to day service facilities among the elderly living in a relatively large municipality. It is now necessary to examine whether the difference in geographical accessibility to day service affects the service utilization.

Muscle layer- and region-dependent distributions of oxytocin receptors in the porcine myometrium

The aim of the present study was to clarify smooth muscle- and region-dependent distributions of the oxytocin receptor that mediates oxytocin-induced contraction in the nonpregnant porcine myometrium by means of mechanical and radioligand ([3H]-oxytocin) binding studies. In Krebs solution, oxytocin (0.1-300 nM) caused concentration-dependent contractions of the cornual myometrium, and the longitudinal muscle was more sensitive than the circular muscle. [Arg8]-vasopressin and [deamino-Cys1, D-Arg8]-vasopressin also contracted the myometrium, and the order of the potency was oxytocin > [Arg8]-vasopressin > [deamino-Cys(1), D-Arg(8)]-vasopressin. Treatment with a high concentration of oxytocin selectively inhibited the contraction of oxytocin and [Arg8]-vasopressin without affecting the responses of acetylcholine and high-K+. Selective cross inhibition was also observed in the presence of a high concentration of [Arg(8)]-vasopressin. The oxytocin-induced contraction was resistant to tetrodotoxin and atropine, but was reduced by verapamil or by the removal of external Ca2+, indicating that oxytocin has a direct action on smooth muscle cells and that extracellular Ca2+ plays an important role for the contraction. In Kumagai solution, oxytocin caused contraction of the cornual longitudinal muscle (-logEC50 = 8.5) but not the circular muscle. Longitudinal muscles of other regions (corpus and cervix) were also responsive to oxytocin, but the -logEC50 value differed from region to region (cornua > corpus = cervix). On the other hand, oxytocin failed to cause contraction of the corpus and cervical circular muscles. 3H-Oxytocin bound to crude membrane preparations of the myometrium in a concentration-dependent (0.084-2.7 nM) saturable manner. Scatchard analysis of equilibrium binding data revealed the presence of a single class of binding site with an apparent dissociation constant (Kd, 1.1-1.5 nM), but receptor density (Bmax) differed in the two muscle layer types (longitudinal muscle: circular muscle = 5:1) and tended to decrease from the cornua to the cervix. In conclusion, the receptor specific for oxytocin is present in the porcine myometrium and mediates the contractile responses of both oxytocin and [Arg8]-vasopressin. The distribution of the oxytocin receptors differs according to the type of muscle layer (longitudinal muscle > circular muscle) and the region of the uterus.

Characterization of the amino acid transport of new immortalized choroid plexus epithelial cell lines: a novel in vitro system for investigating transport functions at the blood-cerebrospinal fluid barrier

PURPOSE

To establish and characterize a choroid plexus epithelial cell line (TR-CSFB) from a new type of transgenic rat harboring the temperature-sensitive simian virus 40 (ts SV 40) large T-antigen gene (Tg rat).

METHODS

Choroid plexus epithelial cells were isolated from the Tg rat and cultured on a collagen-coated dish at 37 degrees C during the first period of 3 days. Cells were subsequently cultured at 33 degrees C to activate large T-antigen. At the third passage, cells were cloned by colony formation and isolated from other cells using a penicillin cup.

RESULTS

Five immortalized cell lines of choroid plexus epithelial cells (TR-CSFB 1 approximately 5) were obtained from two Tg rats. These cell lines had a polygonal cell morphology, expressed the typical choroid plexus epithelial cell marker, transthyretin, and possessed Na+, K+-ATPase on their apical side. TR-CSFBs cells expressed a large T-antigen and grew well at 33 degrees C with a doubling-time of 35 approximately 40 hr. [3H]-L-Proline uptake by TR-CSFB cells took place in an Na+-dependent, ouabain-sensitive, energy-dependent, and concentration-dependent manner. It was also inhibited by alpha-methylaminoisobutylic acid, suggesting that system A for amino acids operates in TR-CSFB cells. When [3H]-L-proline uptake was measured using the Transwell device, the L-proline uptake rate following application to the apical side was five-fold greater than that following application to the basal side. In addition, both Na+-dependent and Na+-independent L-glutamic acid (L-Glu) uptake processes were present in TR-CSFB cells.

CONCLUSIONS

Immortalized choroid plexus epithelial cell lines were successfully established from Tg rats and have the properties of choroid plexus epithelial cells, and amino acid transport activity was observed in vivo.

Hapten-specific tolerance promoted by calcitonin gene-related peptide

Calcitonin gene-related peptide has been shown to modulate inflammatory and immune responses in various systems. Recent studies in our laboratory and colleagues have shown that intracutaneously injected calcitonin gene-related peptide impairs the induction of contact hypersensitivity in mice, and participates in the pathogenesis of failed contact hypersensitivity induction after acute, low-dose ultraviolet B radiation. In this study we investigated the ability of calcitonin gene-related peptide to induce tolerance in normal and mast cell deficient mice and we examined the extent to which calcitonin gene-related peptide contributes to the tolerance induced by acute, low-dose ultraviolet B radiation. Calcitonin gene-related peptide was injected intradermally followed by application of 2,4-dinitro-1-fluorobenzene to the injected skin surface. Tolerance was assessed by re-exposing the mice 2 wk later to a second, sensitizing dose of 2, 4-dinitro-1-fluorobenzene on uninjected skin. We found that calcitonin gene-related peptide induced tolerance to 2, 4-dinitro-1-fluorobenzene in both normal and mast cell deficient mice. Calcitonin gene-related peptide-induced tolerance was blocked by intradermal injection of a calcitonin gene-related peptide antagonist [CGRP-(8-37)] that selectively blocks the calcitonin gene-related peptide receptor. Tolerance was also abolished by intraperitoneally injected anti-interleukin-10, but not anti-tumor necrosis factor alpha, antibodies. When 2,4-dinitro-1-fluorobenzene was painted on skin into which splenic dendritic cells pretreated with calcitonin gene-related peptide had been injected, tolerance was observed. Calcitonin gene-related peptide- treated dendritic cells mixed with anti-interleukin-10 antibody prior to intradermal injection failed to promote tolerance. Finally, injection of CGRP-(8-37) into skin that was subsequently exposed to acute, low-dose ultraviolet B radiation partially prevented tolerance induced by local application of 2,4-dinitro-1-fluorobenzene. These results indicate that calcitonin gene-related peptide has the capacity to promote cutaneous tolerance through an interleukin-10-dependent mechanism. This mechanism, which does not require the participation of mast cells, contributes to the tolerance promoted by acute, low-dose ultraviolet B radiation. Thus, calcitonin gene-related peptide from cutaneous nerve endings plays a key role in the local immune aberrations caused by ultraviolet B radiation.