Factors associated with changes in tacrolimus blood concentration after food initiation in patients with ulcerative colitis.

The therapeutic effect of tacrolimus against ulcerative colitis (UC) is correlated with its trough blood concentration. Conventionally, oral tacrolimus for the treatment of UC is initiated under fasting conditions; once the symptoms improve, food intake is resumed. Tacrolimus blood concentration decreases with food intake compared with that under fasting conditions. The aim of this study was to explore the characteristics of patients with UC whose tacrolimus blood concentrations tended to decrease after food initiation. Medical data of 13 patients with UC and treated with tacrolimus were retrospectively obtained. The participant characteristics associated with the changes in tacrolimus blood concentrations after food initiation were analyzed using regression analysis based on the rate of decrease in the concentration/dose (C/D) ratio after food initiation. Single regression analysis showed that the number of days required from tacrolimus initiation to food resumption (P = 0.0071) and individual differences in the increase in tacrolimus blood concentration after administration (P = 0.0247) were significantly associated with the rate of decrease in the C/D ratio after food initiation. Furthermore, multiple regression analysis showed a significant effect of the number of days to food resumption (P = 0.0004) and individual differences in the increase in tacrolimus blood concentration after administration (P = 0.0012). The results suggest that the degree of change in blood tacrolimus concentration after food initiation may be related to the severity of the symptoms and pathology of UC. Early identification of participant characteristics may help control tacrolimus blood concentration fluctuations after food initiation.

High intensity vanadium beam for synthesis of new superheavy elements with well-controlled emittance by using "slit triplet".

To provide a very powerful vanadium (V) beam with an intensity of at least 6 particle µA for synthesizing a new superheavy element (SHE) with atomic number Z = 119, we have developed a high-temperature oven (HTO) system to evaporate the metallic V powder inside the new superconducting (SC) electron cyclotron ion source. We successfully extracted a V13+ beam with a maximum beam intensity of 600 eµA with 2.8-kW microwave power and 900-W heating power of the HTO. Furthermore, from a systematic study of the dependence of the beam intensity on the microwave power and the HTO power, we successfully produced a V13+ beam of 300 eµA at a consumption rate of 3 mg/h, allowing a one-month duration continuous beam to carry out the SHE synthesis. In addition, to avoid serious damage to newly introduced SC acceleration cavities by beam losses, the beam should be transported with a well-controlled emittance. To efficiently limit the beam emittance, we employed a slit triplet consisting of three pairs of slits installed around the focus point of the low-energy beam transport. The first result of the emittance reduction was observed by a pepper-pot type emittance meter as a function of the acceptance of the slit triplet.

Control system for the new RIKEN 28-GHz superconducting electron cyclotron resonance ion source for SRILAC.

A new RIKEN 28-GHz superconducting electron cyclotron resonance ion source (SC-ECRIS) has been installed for the superconducting RIKEN linear accelerator (SRILAC). The new SC-ECRIS control system mainly consists of programmable logic controllers (PLCs) embedded with the Experimental Physics and Industrial Control System. To improve the reliability as compared with previous control systems, two types of PLC central processing units, sequential and Linux, have been installed in the same unit. Past experience has shown that new types of designs that can rapidly respond to system scalability are key. By connecting PLC stations using star-topology field buses, their rapid and cost-effective response to system changes is realized for the new devices. Furthermore, a unique data acquisition system employing a 920-MHz-band radio was developed to measure analog data such as the temperature at the high-voltage stage.

Development of a pepper-pot emittance meter for diagnostics of low-energy multiply charged heavy ion beams extracted from an ECR ion source.

Several fluorescent materials were tested for use in the imaging screen of a pepper-pot emittance meter that is suitable for investigating the beam dynamics of multiply charged heavy ions extracted from an ECR ion source. SiO2 (quartz), KBr, Eu-doped CaF2, and Tl-doped CsI crystals were first irradiated with 6.52-keV protons to determine the effects of radiation damage on their fluorescence emission properties. For such a low-energy proton beam, only the quartz was found to be a suitable fluorescent material, since the other materials suffered a decay in fluorescence intensity with irradiation time. Subsequently, quartz was irradiated with heavy (12)C(4+), (16)O(4+), and (40)Ar(11+) ions, but it was found that the fluorescence intensity decreased too rapidly to measure the emittance of these heavy-ion beams. These results suggest that a different energy loss mechanism occurs for heavier ions and for protons.

In-beam Mössbauer spectroscopy of (57)Fe/(57)Mn in MgO and NaF at Heavy-Ion Medical Accelerator in Chiba.

Development of efficient ion supply of (58)Fe from (58)Fe(C5H5)2, and quick switching between therapy and material science at the Heavy-Ion Medical Accelerator in Chiba realized a new (57)Mn in-beam emission Mössbauer spectroscopy measurement system. Application to simple binary chemical compounds, MgO and NaF, proved the usefulness of the system to probe chemical and physical behaviors of trace impurities in solids. Annealing of lattice defects produced by the implantation and ß-decay of (57)Mn and/or γ-ray emission recoil was observed by a local probe.

Ghrelin potentiates miniature excitatory postsynaptic currents in supraoptic magnocellular neurones.

Ghrelin is an orexigenic peptide discovered in the stomach as a ligand of the orphan G-protein coupled receptor, and participates in the regulation of growth hormone (GH) release. Previous studies have demonstrated that ghrelin suppressed water intake and stimulated the secretion of arginine vasopressin in rats. We examined the effect of ghrelin on the excitatory synaptic inputs to the magnocellular neurosecretory cells (MNCs) in the supraoptic nucleus (SON) using whole-cell patch-clamp recordings in in vitro rat and mouse brain slice preparations. The application of ghrelin (10(-7) approximately 10(-6) m) caused a significant increase in the frequency of the miniature excitatory postsynaptic currents (mEPSCs) in a dose-related manner without affecting the amplitude. The increased frequency of the spontaneous EPSCs persisted in the presence of tetrodotoxin (1 microM). Des-n-octanoyl ghrelin (10(-6) m) did not have a significant effect on the mEPSCs. The ghrelin-induced potentiation of the mEPSCs was significantly suppressed by previous exposure to the transient receptor potential vanilloid (TRPV) blocker, ruthenium red (10 microM) and GH secretagougue type 1a receptor selective antagonist, BIM28163 (10 microM). The effects of ghrelin on the supraoptic MNCs in trpv1 knockout mice were significantly attenuated compared to those in wild-type mice counterparts. These results suggest that ghrelin participates in the regulation of synaptic inputs to the MNCs in the SON via interaction with the GH secretagogue type 1a receptor, and that the TRPV1 channel may be involved in ghrelin-induced potentiation of mEPSCs to the MNCs in the SON.

Coexistence of hERG current block and disruption of protein trafficking in ketoconazole-induced long QT syndrome.

BACKGROUND AND PURPOSE: Many drugs associated with acquired long QT syndrome (LQTS) directly block human ether-a-go-go-related gene (hERG) K(+) channels. Recently, disrupted trafficking of the hERG channel protein was proposed as a new mechanism underlying LQTS, but whether this defect coexists with the hERG current block remains unclear. This study investigated how ketoconazole, a direct hERG current inhibitor, affects the trafficking of hERG channel protein. EXPERIMENTAL APPROACH: Wild-type hERG and SCN5A/hNa(v) 1.5 Na(+) channels or the Y652A and F656C mutated forms of the hERG were stably expressed in HEK293 cells. The K(+) and Na(+) currents were recorded in these cells by using the whole-cell patch-clamp technique (23 degrees C). Protein trafficking of the hERG was evaluated by Western blot analysis and flow cytometry. KEY RESULTS: Ketoconazole directly blocked the hERG channel current and reduced the amount of hERG channel protein trafficked to the cell surface in a concentration-dependent manner. Current density of the hERG channels but not of the hNa(v) 1.5 channels was reduced after 48 h of incubation with ketoconazole, with preservation of the acute direct effect on hERG current. Mutations in drug-binding sites (F656C or Y652A) of the hERG channel significantly attenuated the hERG current blockade by ketoconazole, but did not affect the disruption of trafficking. CONCLUSIONS AND IMPLICATIONS: Our findings indicate that ketoconazole might cause acquired LQTS via a direct inhibition of current through the hERG channel and by disrupting hERG protein trafficking within therapeutic concentrations. These findings should be considered when evaluating new drugs.

Microarray analysis of human milk cells: persistent high expression of osteopontin during the lactation period.

To continue the search for immunological roles of breast milk, cDNA microarray analysis on cytokines and growth factors was performed for human milk cells. Among the 240 cytokine-related genes, osteopontin (OPN) gene ranked top of the expression. Real-time PCR revealed that the OPN mRNA levels in colostrum cells were approximately 100 times higher than those in PHA-stimulated peripheral blood mononuclear cells (PBMNCs), and 10 000 times higher than those in PB CD14(+) cells. The median levels of OPN mRNA in early milk or mature milk cells were more than three times higher than those in colostrum cells. Western blot analysis of human milk showed appreciable expression of full-length and short form proteins of OPN. The concentrations of full-length OPN in early milk or mature milk whey continued to be higher than those in colostrum whey and plasma as assessed by ELISA. The early milk (3-7 days postpartum) contained the highest concentrations of OPN protein, while the late mature milk cells (1 years postpartum) had the highest expression of OPN mRNA of all the lactating periods. The results of immunohistochemical and immunocytochemical staining indicated that OPN-producing epithelial cells and macrophages are found in actively lactating mammary glands. These results suggest that the persistently and extraordinarily high expression of OPN in human milk cells plays a potential role in the immunological development of breast-fed infants.

Binding affinity of a newly synthesized 5-HT2 antagonist, AT-1015 (N-[2-[4-(5H-Dibenzo[a,d]cyclohepten-5-ylidene)-piperidino]ethyl]-1-formyl-4-piperidinecarboxamide monohydrochloride monohydrate), in the rabbit platelet membrane.

The object of this study was to investigate the binding affinity of a newly synthesized 5-HT2 antagonist, (N-[2-[4-(5H-dibenzo[a,d]cyclohepten-5-ylidene)-piperidino]ethyl]-1-formyl-4-piperidinecarboxamide monohydrochloride monohydrate) (AT-1015), in the rabbit platelet membrane using [3H]-ketanserin by radioligand binding assay method and to compare the results with other selective 5-HT2 antagonists. The results showed that AT-1015 displayed high affinity to 5-HT2 receptors in rabbit platelet membranes. The pKi value of AT-1015 was 7.40, which is slightly lower than that of ketanserin, but higher than that of cyproheptadine. On the other hand, the displacement potency of AT-1015 for 5-HT2 receptors in rabbit platelets was similar to those of sarpogrelate and ritanserin. This is the first report of the high affinity of AT-1015 in rabbit platelets.

Beta-adrenoceptors: three-dimensional structures and binding sites for ligands.

Recent progress in analyzing the structures and functions of G-protein coupled receptors (GPCRs) including beta-adrenoceptors (beta-ARs) has been made by pharmacological, physiological and molecular biological techniques. The three-dimensional (3D) structures, interaction sites with ligands and conformational changes of these receptor subtypes due to ligand binding are now better understood by the simulation of these receptors using computer-aided molecular modeling. Based on these techniques, numbers and conformations of amino acid sequences of each subtype (beta1-, beta2- and beta3-ARs) were defined and also interaction sites or modes of interaction between ligands and beta-ARs could be analyzed three-dimensionally. In addition, simulation of 3D structures of beta-ARs by molecular modeling could clearly determine the limited size, space or pocket for fitting with ligands. These studies will give some clues for the clarification of other GPCRs. Thus, this review summarizes current findings on chemical structures of ligands, amino acid sequences, 3D structures and important amino acids of beta-AR subtypes for interacting with ligands obtained from mutagenesis, chimeric studies and molecular modeling techniques.

Bopindolol: pharmacological basis and clinical implications.

Bopindolol, a non-selective antagonist of beta 1- and beta 2-adrenoceptors (ARs), has been found by pharmacological, molecular biological techniques and molecular modeling to have several unique properties. Bopindolol produces sustained blockade of beta 1- and beta 2-ARs, has intrinsic sympathomimetic as well as membrane stabilizing actions, inhibits renin secretion, and interacts with 5-HT receptors. Also, our recent molecular modeling studies identified possible interaction sites between bopindolol and beta-AR subtypes. The reviewed studies support our findings that bopindolol is non-selective for beta 1- and beta 2-ARs, has low affinity for beta 3-AR subtype and has pharmacological properties that are likely to be beneficial in the treatment of cardiovascular diseases.

Successful treatment with an implantable cardioverter defibrillator for spontaneous ventricular fibrillation in dilated cardiomyopathy with very high defibrillation thresholds.

A 72-year-old male patient with idiopathic dilated cardiomyopathy who had shown recurrent episodes of drug refractory ventricular fibrillation underwent implantation of a transvenous implantable cardioverter defibrillator (ICD). Ventricular fibrillation (VF) was induced by a T wave shock at the implantation. However, the ICD device with a maximum energy of 30 J failed to terminate the VF. Reversing defibrillation polarity and/or adding a defibrillation electrode lead at the site of a high superior vena cava were also ineffective. The ICD was programmed to a maximum energy of 30 J when the device sensed spontaneous VF. During the follow-up period of 5 months, two episodes of spontaneous VF were recorded from ICD telemetry, and the ICD device terminated VF successfully with the first therapy shock in both episodes. No previous reports have shown failure to terminate induced VF at implantation of the ICD with successful termination of spontaneous VF during follow-up. Careful follow-up is needed in ICD patients, especially those with very high defibrillation thresholds.

A novel 5-HT(2) antagonist, sarpogrelate hydrochloride, shows inhibitory effects on both contraction and relaxation mediated by 5-HT receptor subtypes in porcine coronary arteries.

In isolated porcine coronary arteries, concentrations of 5-HT (10(-8) to 3x10(-5) mol/l), alpha-methylserotonin (alpha-Me-5-HT, 10(-8) to 3x10(-5) mol/l) and ergonovine (10(-9) to 3x10(-4) mol/l) produced contraction, whereas high concentrations (10(-5) to 10(-4) mol/l) of these drugs produced relaxation. Both sarpogrelate and ketanserin produced rightward shifts of contraction concentration-response curves induced by 5-HT and alpha-Me-5-HT at the concentration from 10(-9) to 3x10(-5) mol/l, and only sarpogrelate inhibited the relaxation at high concentrations of 5-HT and displayed 155% of maximal contraction at 10(-4) mol/l 5-HT. On the other hand, sarpogrelate and ketanserin did not show any inhibitory effects on the relaxation induced by high concentrations of ergonovine. These results suggested that sarpogrelate and ketanserin show different inhibitory effects on the relaxation induced by high concentrations of 5-HT, indicating that these two drugs may have different affinities to 5-HT receptor subtypes that may be involved in relaxation.

Effect of a single oral dose of pilsicainide on pacing thresholds in pacemaker patients with and without paroxysmal atrial fibrillation.

A single oral dose of pilsicainide, a class 1c antiarrhythmic drug, is effective in terminating acute-onset atrial fibrillation (AF), but its effect on pacing thresholds in pacemaker patients is unknown. The present study measured atrial and ventricular pacing thresholds after a single oral dose of pilsicainide in patients with and without AF. Twelve patients with dual-chamber pacemakers were evaluated. Pacing thresholds as well as plasma pilsicainide concentration were measured prior to and then at 30, 60, 90, 120 and 180 min and 24h following a single oral dose of pilsicainide (150 mg). Six patients had paroxysmal AF and the remaining 6 did not. Pacing thresholds increased significantly (134+/-8%) in the atrium (p<0.05) and in the ventricle (155+/-11%; p<0.001) following pilsicainide administration in all 12 patients. Plasma concentrations of pilsicainide showed a positive liner correlation with pacing thresholds (R=0.62, p<0.0001 in the atrium; R=0.74, p<0.0001 in the ventricle). Atrial pacing thresholds in the patients with AF showed a significant increase at 90, 120 and 180 min compared with the patients without AF (p<0.05). There was no significant difference in either the ventricular pacing threshold or the plasma pilsicainide concentration in the patients with and without AF. It was concluded that a single oral dose of pilsicainide increases the pacing thresholds in both the atrium and ventricle in a selected group of pacemaker-implanted patients; that is, those who are aged and with AF. Thus, careful attention should be paid to pacemaker-dependent patients, particularly those with paroxysmal AF, when administering pilsicainide.

Paradoxical AV delay shortening of a pacemaker.

Paradoxical shortening of the paced AV delay (atrial paced-ventricular paced or Ap-Vp interval) was observed at rest in the DDD and DDDR modes in three patients with implanted CPI Vigor DR pacemakers programmed with a long AV delay and a relatively narrow difference between the lower and upper rates. This behavior is related to the VA extension algorithm designed to prevent the sensor-driven atrial pacing rate from exceeding the programmed upper rate whenever a sensed conducted QRS complex continually follows an atrial stimulus. We found that this algorithm also becomes manifest at rest and may cause shortening of the Ap-Vp intervals. The VA extension algorithm is best conceptualized in terms of a separate atrial upper rate that functions on exercise and at rest. The atrial and ventricular upper rates are equal but the atrial upper rate is initiated by an atrial-paced or sensed event and the ventricular upper rate is initiated by a paced or sensed ventricular event. Under certain circumstances delay in the release of the atrial stimulus Ap to conform to the atrial upper rate interval produces variable abbreviation of the paced AV (Ap-Vp) delays with resultant variation in the duration of the atrial escape intervals despite fundamental ventricular-based lower rate timing.

Ventricular pacing failure after a single oral dose of pilsicainide in a patient with a permanent pacemaker and paroxysmal atrial fibrillation.

A single oral dose of pilsicainide, a Class Ic antiarrhythmic drug, is a widely used and highly effective therapy for termination of recent onset atrial fibrillation. We report on a patient in which ventricular pacing failure occurred immediately after a single oral dose of pilsicainide. It did not exhibit a parallel relationship between the change in the pacing threshold and plasma concentration of pilsicainide, and the recovery period for the ventricular pacing threshold was longer than that of the plasma concentration of pilsicainide in this patient. Careful attention should be paid when a single oral dose of pilsicainide for termination of recent onset atrial fibrillation is used in patients with permanent pacemakers.

Inhibitory effects of a newly synthesized 5-HT2 receptor antagonist, AT-1015 (N-[2-[4-(5H-dibenzo[a,d]cyclohepten-5-ylidene)piperidino]-ethyl]-1-for myl-4-piperidinecarboxamide monohydrochloride monohydrate), on contraction and relaxation of pig coronary arteries induced by 5-HT and alpha-methylserotonin: comparison with ketanserin.

Inhibitory effects of a newly synthesized 5-HT2 receptor antagonist, AT-1015 (N-[2-[4-(5H-dibenzo[a,d]cyclohepten-5-ylidene)piperidinolethyl ]-1-formyl-4-piperidinecarboxamide monohydrochloride monohydrate) on contraction and relaxation of coronary arteries of pig hearts mediated by 5-HT2 subtypes were evaluated and these results were compared with those of ketanserin. Contraction and relaxation were determined by adding 5-HT or alpha-methylserotonin (alpha-Me-5-HT) as agonists. Although ketanserin induced rightward shifts of contraction, AT-1015 inhibited the maximal response. In addition, ketanserin inhibited relaxation induced by high concentration of agonists, but there were no inhibitory effects of AT-1015 on relaxation. Thus, these results suggest that AT-1015 is a strong non-competitive 5-HT2 antagonist in porcine coronary arteries and that this drug clearly exhibited different effects on the contraction and relaxation of coronary arteries of pig hearts from those of ketanserin.

Recent advances in structure, binding sites with ligands and pharmacological function of beta-adrenoceptors obtained by molecular biology and molecular modeling.

The structure, binding sites interacting with ligands and the physiological functions of G-protein coupled beta-adrenoceptors (beta-ARs) are being elucidated by molecular biology and molecular modeling studies. The definition given amino acid sequences of beta-ARs in molecular biology and the analysis of three-dimensional and functional binding sites interacting with ligands by molecular modeling may be important for identifying other functional beta-ARs in various tissues and discovering new drugs. Thus, this review focuses on the interaction sites for receptor-ligand and roles of functional beta-ARs as studied by molecular biology and molecular modeling.