Acotiamide Hydrochloride, a Therapeutic Agent for Functional Dyspepsia, Enhances Acetylcholine-induced Contraction via Inhibition of Acetylcholinesterase Activity in Circular Muscle Strips of Guinea Pig Stomach

Acotiamide is a first-in-class prokinetic drug approved in Japan for the treatment of functional dyspepsia. Given that acotiamide enhances gastric motility in conscious dogs and rats, we assessed the in vitro effects of this drug on the contraction of guinea pig stomach strips and on acetylcholinesterase (AChE) activity in stomach homogenate following fundus removal. We also investigated the serotonin 5-HT4 receptor agonist mosapride, dopamine D2 receptor and AChE inhibitor itopride, and representative AChE inhibitor neostigmine. Acotiamide (0.3 and 1 μM) and itopride (1 and 3 μM) significantly enhanced the contraction of gastric body strips induced by electrical field stimulation (EFS), but mosapride (1 and 10 μM) did not. Acotiamide and itopride significantly enhanced the contraction of gastric body and antrum strips induced by acetylcholine (ACh), but not that induced by carbachol (CCh). Neostigmine also significantly enhanced the contraction of gastric body strips induced by ACh, but not that by CCh. In contrast, mosapride failed to enhance contractions induced by either ACh or CCh in gastric antrum strips. Acotiamide exerted mixed inhibition of AChE, and the percentage inhibition of acotiamide (100 μM) against AChE activity was markedly reduced after the reaction mixture was dialyzed. In contrast, itopride exerted noncompetitive inhibition on AChE activity. These results indicate that acotiamide enhances ACh-dependent contraction in gastric strips of guinea pigs via the inhibition of AChE activity, and that it exerts mixed and reversible inhibition of AChE derived from guinea pig stomach.

Variation in patient position and impact on carbon-ion scanning beam distribution during prostate treatment

OBJECTIVE

We assessed the impact of changes in patient position on carbon-ion scanning beam distribution during treatment for prostate cancer.

METHODS

68 patients were selected. Carbon-ion scanning dose was calculated. Two different planning target volumes (PTVs) were defined: PTV1 was the clinical target volume plus a set-up margin for the anterior/lateral sides and posterior side, while PTV2 was the same as PTV1 minus the posterior side. Total prescribed doses of 34.4 Gy [relative biological effectiveness (RBE)] and 17.2 Gy (RBE) were given to PTV1 and PTV2, respectively. To estimate the influence of geometric variations on dose distribution, the dose was recalculated on the rigidly shifted single planning CT based on two dimensional-three dimensional rigid registration of the orthogonal radiographs before and after treatment for the fraction of maximum positional changes.

RESULTS

Intrafractional patient positional change values averaged over all patients throughout the treatment course were less than the target registration error = 2.00 mm and angular error = 1.27°. However, these maximum positional errors did not occur in all 12 treatment fractions. Even though large positional changes occurred during irradiation in all treatment fractions, lowest dose encompassing 95% of the target (D95)-PTV1 was >98% of the prescribed dose.

CONCLUSION

Intrafractional patient positional changes occurred during treatment beam irradiation and degraded carbon-ion beam dose distribution. Our evaluation did not consider non-rigid deformations, however, dose distribution was still within clinically acceptable levels.

ADVANCES IN KNOWLEDGE

Inter- and intrafractional changes did not affect carbon-ion beam prostate treatment accuracy.

PRPF8 defects cause missplicing in myeloid malignancies

Mutations of spliceosome components are common in myeloid neoplasms. One of the affected genes, PRPF8, encodes the most evolutionarily conserved spliceosomal protein. We identified either recurrent somatic PRPF8 mutations or hemizygous deletions in 15/447 and 24/450 cases, respectively. 50% of PRPF8 mutant and del(17p) cases were found in AML and conveyed poor prognosis. PRPF8 defects correlated with increased myeloblasts and ring sideroblasts in cases without SF3B1 mutations. Knockdown of PRPF8 in K562 and CD34+ primary bone marrow cells increased proliferative capacity. Whole RNA deep sequencing of primary cells from patients with PRPF8 abnormalities demonstrated consistent missplicing defects. In yeast models, homologous mutations introduced into Prp8 abrogated a block experimentally produced in the second step of the RNA splicing process suggesting that the mutants have defects in proof-reading functions. In sum, the exploration of clinical and functional consequences suggests that PRPF8 is a novel leukemogenic gene in myeloid neoplasms with a distinct phenotype likely manifested through aberrant splicing.

Landscape of genetic lesions in 944 patients with myelodysplastic syndromes

High-throughput DNA sequencing significantly contributed to diagnosis and prognostication in patients with myelodysplastic syndromes (MDS). We determined the biological and prognostic significance of genetic aberrations in MDS. In total, 944 patients with various MDS subtypes were screened for known/putative mutations/deletions in 104 genes using targeted deep sequencing and array-based genomic hybridization. In total, 845/944 patients (89.5%) harbored at least one mutation (median, 3 per patient; range, 0-12). Forty-seven genes were significantly mutated with TET2, SF3B1, ASXL1, SRSF2, DNMT3A, and RUNX1 mutated in >10% of cases. Many mutations were associated with higher risk groups and/or blast elevation. Survival was investigated in 875 patients. By univariate analysis, 25/48 genes (resulting from 47 genes tested significantly plus PRPF8) affected survival (P<0.05). The status of 14 genes combined with conventional factors revealed a novel prognostic model ('Model-1') separating patients into four risk groups ('low', 'intermediate', 'high', 'very high risk') with 3-year survival of 95.2, 69.3, 32.8, and 5.3% (P<0.001). Subsequently, a 'gene-only model' ('Model-2') was constructed based on 14 genes also yielding four significant risk groups (P<0.001). Both models were reproducible in the validation cohort (n=175 patients; P<0.001 each). Thus, large-scale genetic and molecular profiling of multiple target genes is invaluable for subclassification and prognostication in MDS patients.

Peristaltic hemodynamics of a new pediatric circulatory assist system for Fontan circulation using shape memory alloy fibers

Fontan procedure is one of the common surgical treatments of congenital heart diseases. Patients with Fontan circulation have single ventricle in the systemic circulation with the total cavopulmonary connection. We have been developing a pulmonary circulatory assist device using shape memory alloy fibers for Fontan circulation with total cavopulmonary connection. It consisted of the shape memory alloy fibers, the diameter of which are 100 µm. The fibers could wrap the ePTFE conduit for Fontan TCPC connection from the outside. We designed the sequential motion control system for sophisticated pulmonary hemodynamics by the pulsatile flow generation. In order to achieve pulsatile flow assistance in pulmonary arterial system, we fabricated a mechanical structure by sequential contraction of shape memory alloy fibers. Then, we developed a sequential contraction controller for the assist system, which could reproduce the wall contractile velocity at 6.0 to 20.0 cm/sec. We examined hemodynamic characteristic of its function using a mock circulatory system, which consisted of two overflow tanks representing venous and pulmonary arterial pressures in Fontan circulation. As a result, the pulmonary circulation assist device with sequential contraction could achieve effective promotion of the pulsatility in pulmonary arterial flow.

Controlling methods of a newly developed extra aortic counter-pulsation device using shape memory alloy fibers

Diastolic counter-pulsation has been used to provide circulatory augmentation for short term cardiac support. The success of intra-aortic balloon pump (IABP) therapy has generated interest in long term counter-pulsation strategies to treat heart failure patients. The authors have been developing a totally implantable extra aortic pulsation device for the circulatory support of heart failure patients, using 150 µm Ni-Ti anisotropic shape memory alloy (SMA) fibers. These fibers contract by Joule heating with an electric current supply. The special features of our design are as follow: non blood contacting, extra aortic pulsation function synchronizing with the native heart, a wrapping mechanical structure for the aorta in order to achieve its assistance as the aortomyoplsty and the extra aortic balloon pump. The device consisted of rubber silicone wall plates, serially connected for radial contraction. We examined the contractile function of the device, as well as it controlling methods; the phase delay parameter and the pulse width modulation, in a systemic mock circulatory system, with a pneumatically driven silicone left ventricle model, arterial rubber tubing, a peripheral resistance unit, and a venous reservoir. The device was secured around the aortic tubing with a counter-pulsation mode of 1:4 against the heartbeat. Pressure and flow waveforms were measured at the aortic outflow, as well as its driving condition of the contraction phase width and the phase delay. The device achieved its variable phase control for co-pulsation or counter-pulsation modes by changing the phase delay of the SMA fibers. Peak diastolic pressure significantly augmented, mean flow increased (p<0.05) according to the pulse width modulation. Therefore the newly developed extra aortic counter-pulsation device using SMA fibers, through it controlling methods indicated its promising alternative extra aortic approach for non-blood contacting cardiovascular circulatory support.

Analysis of Heat Flu from Molten Polymers to Molds in Injection Molding Processes

The inverse analysis method is applied in the evaluation of heat flux at the interface between the molten polymer and the mold during the injection molding process. In addition, the dependence of cooling behavior on both the molding conditions and the material properties of the resin are investigated. During low-velocity polymer flow in the thick regions of the mold cavity, the heat flux in the later stage of the process evaluated through experiment correlates well with the theoretical results of equations describing heat conduction at the interface of two semi-infinite objects. In contrast, in the thin region of the mold cavity, the analyzed heat flux is greater than the theoretical result for high-velocity polymer flow, and the difference expands with an increase in the shear rate at the wall of the mold. Based on these results, a simple empirical equation applicable to a wide range of molding conditions is proposed for the estimation of heat flux at the polymer-mold interface.

Examination of mitral regurgitation with a goat heart model for the development of intelligent artificial papillary muscle

Annuloplasty for functional mitral or tricuspid regurgitation has been made for surgical restoration of valvular diseases. However, these major techniques may sometimes be ineffective because of chamber dilation and valve tethering. We have been developing a sophisticated intelligent artificial papillary muscle (PM) by using an anisotropic shape memory alloy fiber for an alternative surgical reconstruction of the continuity of the mitral structural apparatus and the left ventricular myocardium. This study exhibited the mitral regurgitation with regard to the reduction in the PM tension quantitatively with an originally developed ventricular simulator using isolated goat hearts for the sophisticated artificial PM. Aortic and mitral valves with left ventricular free wall portions of isolated goat hearts (n=9) were secured on the elastic plastic membrane and statically pressurized, which led to valvular leaflet-papillary muscle positional change and central mitral regurgitation. PMs were connected to the load cell, and the relationship between the tension of regurgitation and PM tension were measured. Then we connected the left ventricular specimen model to our hydraulic ventricular simulator and achieved hemodynamic simulation with the controlled tension of PMs.

A new control method depending on primary phase angle of transcutaneous energy transmission system for artificial heart

A new control method for stabilizing output voltage of the transcutaneous energy transmission system for artificial heart is proposed. This method is primary side, is outside of the body, which is not depending on a signal transmission system from the implanted device. The impedance observed from primary side changes from inductive to capacitive and the output voltage decreases drastically when the output current is large and the coupling factor is higher than that of the optimal condition. In this case, the driving frequency should be changed to higher so that the phase angle of the primary impedance is zero degree. The preliminary examination showed that this control method can enhance the output voltage limit to twice and the feasibility of the primary side control.

Elimination of Teicoplanin by Adsorption to the Filter Membrane during Haemodiafiltration: Screening Experiments for Linezolid, Teicoplanin and Vancomycin followed by in vitro Haemodiafiltration Models for Teicoplanin

Pharmaceutical agents directed against methicillin-resistant Staphylococcus aureus can be eliminated during haemodiafiltration, not only by diffusion and ultrafiltration, but also by adsorption onto haemofilters. The latter may be affected by the binding of agents to serum albumin. The present study therefore investigated the affinity of anti-methicillin-resistant Staphylococcus aureus agents (teicoplanin, linezolid, vancomycin) for haemofilters and the pharmacokinetic properties of teicoplanin during haemodiafiltration. Linezolid, teicoplanin and vancomycin were first screened for their in vitro affinity for three different kinds of filter membranes: polysulfone, polyacrylonitrile and polymethylmethacrylate. Only teicoplanin showed significant filter-binding activity. An in vitro haemodiafiltration circulation model was then developed that incorporated a one-litre beaker containing Krebs-Ringer's bicarbonate solution with/without human albumin (0 or 3 g/dl) as an artificial plasma. Teicoplanin (initial concentration 50 μg/ml, representing the maximum plasma concentration (Cmax) resulting from a typical clinical dosage) was circulated throughout the beaker. Teicoplanin concentrations in the ‘plasma’ and ultrafiltrate were determined by high performance liquid chromatography. In the screening experiment, teicoplanin was predominantly adsorbed onto polysulfone and polymethylmethacrylate membranes. Furthermore, teicoplanin was primarily eliminated by adsorption onto these filters during in vitro haemodiafiltration. Albumin significantly reduced both haemodiafiltration clearance and the adsorption-dependent elimination, although there were complex but significant interactions between albumin and the filter membrane. Elimination of teicoplanin in an in vitro haemodiafiltration model was largely due to adsorption onto polysulfone and polymethylmethacrylate haemofilters. Future clinical studies should likely be designed to evaluate present recommendations of teicoplanin dosages in patients on haemodiafiltration.

Template for preparation of papers for IEEE sponsored conferences & Symposia

Rotary blood pumps which have contact-less suspension are small, durable and widely used for left ventricular assist devices (LVADs). In order to design a total artificial heart (TAH) with rotary blood pumps, two pumps one for each ventricle, are controlled independently. Some of the challenges for the development of a TAH includes the requirement of a small size and the anatomical fitting of inlets and outlets which should be arranged closely on the circumference in the same direction. And they should be combined into a unit. In this paper, a helical flow total artificial heart (HFTAH) combing two centrifugal pumps with helical inlet in face is proposed in order to achieve a smaller TAH. To examine the pump performance, a preliminary test model for left ventricle was built, the size of the pump was 69.0mm in diameter and 45.0mm height. The size of the impeller was 44.0mm in diameter and 23.0mm height including a 15.0mm-height hydrodynamic bearing. The pump was externally driven by a direct current motor. 5.0L/min flow rate against 100mmHg pressure difference was obtained, where the total power consumption was 5.0W, the system efficiency was 23% with a rotational speed of 2070rpm. In this system, maximum pressure head, flow rate and efficiency were 420mmHg, 15.0L/min and 26%, respectively. In acute animal experiments with three healthy adult goats, the total biventricular bypass assist system using the pumps was able to maintain the maximum aortic flow at approximately 5.0L/min, and the pulmonary arterial flow at approximately 4.6L/min, the mean aorta pressure was 105mmHg, and the mean pulmonary artery pressure was 51mmHg. The development of the control method is undergoing, and a driving system and the pump aiming at the chronic animal experiments will be developed.

Structural design of a newly developed pediatric circulatory assist device for Fontan circulation by using shape memory alloy fiber

Total cavopulmonary connection (TCPC) is commonly applied for the surgical treatment of congenital heart disease such as single ventricle in pediatric patients. Patients with no ventricle in pulmonary circulation are treated along with Fontan algorithm, in which the systemic venous return is diverted directly to the pulmonary artery without passing through subpulmonary ventricle. In order to promote the pulmonary circulation after Fontan procedure, we developed a newly designed pulmonary circulatory assist device by using shape memory alloy fibers. We developed a pulmonary circulatory assist device as a non-blood contacting mechanical support system in pediatric patients with TCPC. The device has been designed to be installed like a cuff around the ePTFE TCPC conduit, which can contract from outside. We employed a covalent type functional anisotropic shape memory alloy fiber (Biometal, Toki Corporation, Tokyo Japan) as a servo actuator of the pulmonary circulatory assist device. The diameter of this fiber was 100 microns, and its contractile frequency was 2-3 Hz. Heat generation with electric current contracts these fibers and the conduit. The maximum contraction ratio of this fiber is about 7% in length. In order to extend its contractile ratio, we fabricated and installed mechanical structural units to control the length of fibers. In this study, we examined basic contractile functions of the device in the mock system. As a result, the internal pressure of the conduit increased to 63 mmHg by the mechanical contraction under the condition of 400 msec-current supply in the mock examination with the overflow tank of 10 mmHg loading.

Effects of combination therapy with montelukast and carbocysteine in allergen-induced airway hyperresponsiveness and airway inflammation

BACKGROUND AND PURPOSE

Montelukast and S-carbocysteine have been used in asthmatic patients as an anti-inflammatory or mucolytic agent respectively. S-carbocysteine also exhibits anti-inflammatory properties.

EXPERIMENTAL APPROACH

Ovalbumin (OVA) sensitized BALB/c mice were challenged with OVA for 3 days followed by single OVA re-challenge (secondary challenge) 2 weeks later. Forty-eight hours after secondary challenge, mice were assessed for airway hyperresponsiveness (AHR) and cell composition in bronchoalveolar lavage (BAL) fluid. Suboptimal doses of 10 mg.kg(-1) of S-carbocysteine by intraperitoneal injection (ip), 20 mg.kg(-1) of montelukast by gavage, the combination of S-carbocysteine and montelukast or 3 mg.kg(-1) of dexamethasone as a control were administered from 1 day before the secondary challenge to the last experimental day. Isolated lung cells were cultured with OVA and montelukast to determine the effects on cytokine production.

KEY RESULTS

Treatment with S-carbocysteine or montelukast reduced both AHR and the numbers of eosinophils in BAL fluid. Neutralizing IFN-gamma abolished the effects of S-carbocysteine on these airway responses. Combination of the two drugs showed further decreases in both AHR and eosinophils in the BAL fluid. Goblet cell metaplasia and Th2-type cytokines, interleukin (IL)-4, IL-5 and IL-13, in BAL fluid were decreased with montelukast treatment. Conversely, S-carbocysteine increased Th1-type cytokines, IFN-gamma and IL-12 in BAL fluid.

CONCLUSIONS AND IMPLICATIONS

The combination of two agents, montelukast and S-carbocysteine, demonstrated additive effects on AHR and airway inflammation in a secondary allergen model most likely through independent mechanisms of action.

[Thoracoplasty]

Thoracoplasty was at 1st invented for the treatment of pulmonary tuberculosis during the days when no effective chemotherapeutic drugs for tuberculosis were available. Removal of some portions of the ribs by thoracoplasty deforms the chest wall and compresses tuberculous cavities. Since the introduction of potent anti-tuberculous drugs, thoracoplasty for pulmonary tuberculosis has been obsolete. Currently, thoracoplasty is mainly applied to reduction of the volume of the pleural space in the treatment of post-resectional space problems and in the treatment of thoracic empyema. Well-planned and safe resections of the affected ribs hold the keys to successful thoracoplasty. The procedure is performed alone or with muscle flaps or with omental flap, depending on the extent of space and the presence of bronchopleural fistula. Thoracic surgeons should know the current application of thoracoplasty.

Clinical comparison of two different types of bifurcated graft for postoperative baPWV and ABI

AIM

A newly-designed bifurcated graft with the distal end larger than the conventional type has been developed. The purpose of this study was to evaluate the early results of graft replacement using this new graft, and to compare whether the new graft is more advantageous than the conventional graft in terms of peripheral blood flow and arterial stiffness.

METHODS

Records of 36 patients who underwent bifurcated graft replacement for infrarenal abdominal aortic aneurysm (AAA), from May 2003 to September 2006 were reviewed after excluding peripheral arterial disease (ABI > 0.9). Subjects were divided into two groups: group C (N.=20), with implantation of the conventional type and group N (N.=16), with implantation of the new type. We investigated changes in brachial-ankle pulse wave velocity (baPWV) and ankle-brachial pressure index (ABI), measurements being performed preoperatively and postoperatively.

RESULTS

baPWV in the postoperative group as a whole was significantly higher than in the preoperative group (P<0.05), while ABI in the postoperative group was lower than in the preoperative group (P<0.05). In group C, baPWV increased (P<0.05) and ABI decreased (P<0.05) after bifurcated graft replacement, whereas in group N, there were no significant differences in changes of baPWV and ABI.

CONCLUSIONS

This study shows that the new graft reduces the development of arterial stiffness postoperatively compared with the conventional type. These results may predict the new type graft decrease in the risk of morbidity and mortality caused by atherosclerotic disease.

Sensorless control for a sophisticated artificial myocardial contraction by using shape memory alloy fibre

The authors have been developing an artificial myocardium, which is capable of supporting natural contractile function from the outside of the ventricle. The system was originally designed by using sophisticated covalent shape memory alloy fibres, and the surface did not implicate blood compatibility. The purpose of our study on the development of artificial myocardium was to achieve the assistance of myocardial functional reproduction by the integrative small mechanical elements without sensors, so that the effective circulatory support could be accomplished. In this study, the authors fabricated the prototype artificial myocardial assist unit composed of the sophisticated shape memory alloy fibre (Biometal), the diameter of which was 100 microns, and examined the mechanical response by using pulse width modulation (PWM) control method in each unit. Prior to the evaluation of dynamic characteristics, the relationship between strain and electric resistance and also the initial response of each unit were obtained. The component for the PWM control was designed in order to regulate the myocardial contractile function, which consisted of an originally-designed RISC microcomputer with the input of displacement, and its output signal was controlled by pulse wave modulation method. As a result, the optimal PWM parameters were confirmed and the fibrous displacement was successfully regulated under the different heat transfer conditions simulating internal body temperature as well as bias tensile loading. Then it was indicated that this control theory might be applied for more sophisticated ventricular passive or active restraint by the artificial myocardium on physiological demand.

Assessment of synchronization measures for effective ventricular support by using the shape memory alloy fibred artificial myocardium in goats

Thromboembolic and haemorrhagic complications are the primary causes of mortality and morbidity in patients with artificial hearts, which are known to be induced by the interactions between blood flow and artificial material surfaces. The authors have been developing a new mechanical artificial myocardial assist device by using a sophisticated shape memory alloy fibre in order to achieve the mechanical cardiac support from outside of the heart without a direct blood contacting surface. The original material employed as the actuator of artificial myocardial assist devices was 100um fibred-shaped, which was composed of covalent and metallic bonding structure and designed to generate 4-7 % shortening by Joule heating induced by the electric current input. In this study, we focused on the synchronization of the actuator with native cardiac function, and the phase delay parameter was examined in animal experiments using Saanen goats. Total weight of the device including the actuator was around 150g, and the electric power was supplied transcutaneously. The device could be successfully installed into thoracic cavity, which was able to be girdling the left ventricle. The contraction of the device could be controlled by the originally designed microcomputer. The mechanical contraction signal input had been transmitted with the phase delay of 50-200 msec after the R-wave of ECG, and hemodynamic changes were investigated. Cardiac output and systolic left ventricular pressure were elevated with 20% delay of cardiac cycle by 27% and 7%, respectively, although there was smaller difference under the condition of the delay of over 30%. Therefore, it was suggested that the synchronization measures should be examined in order to achieve sophisticated ventricular passive/active support on physiological demand.

[Locally advanced non-small cell lung cancer completely resected after induction therapy]

We analyzed 8 patients with unresectable locally advanced non-small cell lung cancer who responded to chemotherapy or chemoradiotherapy and underwent complete resection between June 2003 and June 2005. The patients were all male with a mean age of 61 years (range, 42 to 72 years). Histological subtypes included adenocarcinoma in 4 patients and squamous cell carcinoma in 4 patients. Clinical staging included T2N2M0 in 3 patients, T2N3M0 in 2 patients, and 1 patient each for T3N2M0, T4N2M0, and T4N3M0. Preoperative treatment included chemotherapy in 5 patients and chemoradiotherapy in 3 patients, all of whom had a partial response. Surgical procedures included lobectomy in 6 patients and pneumonectomy in 2 patients. In addition, all of the patients underwent mediastinal lymph node dissection (ND2a). Pathological effect included Ef. 0 in 1 patient, Ef. 1 in 2 patients, Ef. 2 in 2 patients, Ef. 3 in 3 patients. The median survival time from initial treatment (or surgery) was 16 (14) months in all cases, 22 (19) for ycN0, 12 (8) for ycN2, 31 (27) for Ef. 3, 13 (9) for Ef. 0-2, 27 (23) for pN0, 13 (9) for pN1-3, 31 (27) for chemoradiotherapy, 16 (13) for chemotherapy, 24 (21) for adenocarcinoma, and 15 (11) for squamous cell carcinoma. Multimodality treatment, including surgery, is beneficial for patients with unresectable locally advanced non-small cell lung cancer who respond to chemotherapy or chemoradiotherapy, especially those patients with ycN0 or pN0.