Isolated intestinal neuronal dysplasia Type B (IND-B) in Japan: results from a nationwide survey.

PURPOSE: Intestinal neuronal dysplasia Type B (IND-B) has been proposed to be an allied disorder of Hirschsprung's disease (ADHD). The original histological criteria included hyperganglionosis, giant ganglia, ectopic ganglion cells and an increased AChE activity in the lamina propria. The criteria for IND-B have been gradually revised. The present diagnostic criteria are [1] more than 20 % of the submucosal ganglia contain nine or more ganglion cells and [2] the patient is older than 1 year. To clarify the current status of IND-B in Japan, a nationwide retrospective cohort study was performed. METHODS: Questionnaires were sent to 161 major institutes of pediatric surgery and gastroenterology in Japan. RESULTS: A total of 355 cases of ADHD were collected, including 18 cases of IND-B (5 %). Based on original criteria, 13 out of 18 cases were diagnosed as IND-B. However, only four cases met the current criteria. Three of the four patients (75 %) required pull-through operation. All of the patients exhibited giant ganglia and ganglioneuromatosis-like hyperplasia of the myenteric plexus. CONCLUSIONS: IND-B cases matching the current criteria are thought to be quite rare and they are associated with marked hyperplasia of the myenteric plexus. "True" IND-B is a rare and intractable disease.

Effectiveness of endoscopic surgery training for medical students using a virtual reality simulator versus a box trainer: a randomized controlled trial.

BACKGROUND: The first step toward increasing the level of patient safety in endoscopic surgery is for all endoscopic surgeons to acquire fundamental skills, including psychomotor skills, in the preoperation stage of training. The current study aimed to evaluate the effectiveness of virtual reality (VR) simulator training and box training for training the fundamental skills of endoscopic surgery. METHODS: For this study, 35 medical students at Kyushu University were divided into three groups: simulator (SIM) group (n = 20), box trainer (BOX) group (n = 20), and control group (n = 15). None of the students had any experience assisting with endoscopic surgery or any previous training for endoscopic surgery. The students in the SIM group underwent training using a VR simulator, the Procedicus MIST, 2 h per day for 2 days. The students in the BOX group underwent training using a box trainer 2 h per day for 2 days. The students in the control group watched an educational video for 30 min. The endoscopic surgical skills of all the students were evaluated before and after training with a task of suturing and knot tying using a box trainer. RESULTS: Although no significant differences were found between the three groups in the total time taken to complete the evaluation task before training, there were significant improvements in the SIM and BOX groups after training compared with the control group. Box training increased errors during the task, but simulator training did not. CONCLUSION: The findings showed that box training and VR training have different outcomes. The authors expect that the best curriculum for their training center would involve a combination that uses the merits of both methods.

Estimation of the energy expenditure of grazing ruminants by incorporating dynamic body acceleration into a conventional energy requirement system.

The estimation of energy expenditure (EE) of grazing animals is of great importance for efficient animal management on pasture. In the present study, a method is proposed to estimate EE in grazing animals based on measurements of body acceleration of animals in combination with the conventional Agricultural and Food Research Council (AFRC) energy requirement system. Three-dimensional body acceleration and heart rate were recorded for tested animals under both grazing and housing management. An acceleration index, vectorial dynamic body acceleration (VeDBA), was used to calculate activity allowance (AC) during grazing and then incorporate it into the AFRC system to estimate the EE (EE derived from VeDBA [EE]) of the grazing animals. The method was applied to 3 farm ruminant species (7 cattle, 6 goats, and 4 sheep). Energy expenditure based on heart rate (EE) was also estimated as a reference. The result showed that larger VeDBA and heart rate values were obtained under grazing management, resulting in greater EE and EE under grazing management than under housing management. There were large differences between the EE estimated from the 2 methods, where EE values were greater than EE (averages of 163.4 and 142.5% for housing and grazing management, respectively); the EE was lower than the EE, whereas the increase in EE under grazing in comparison with housing conditions was larger than that in EE. These differences may have been due to the use of an equation for estimating EE derived under laboratory conditions and due to the presence of the effects of physiological, psychological, and environmental factors in addition to physical activity being included in measurements for the heart rate method. The present method allowed us to separate activity-specific EE (i.e., AC) from overall EE, and, in fact, AC under grazing management were about twice times as large as those under housing management for farm ruminant animals. There is evidence that the conventional energy system can predict fasting metabolism and the AC of housed animals based on accumulated research on energy metabolism and that VeDBA can quantify physical activity separately from other factors in animals on pasture. Therefore, the use of the VeDBA appears to be a precise way to predict activity-specific EE under grazing conditions, and the method incorporating acceleration index data with a conventional energy system can be a simple and useful method for estimation of EE in farm ruminants on pastures.

Interventional navigation for abdominal therapy based on simultaneous use of MRI and ultrasound.

An interventional navigation system designed for percutaneous abdominal therapies was proposed, and a pilot study was carried out to assess the proposed system. Integration of US to MRI-based segmentation and 3D display of tumours can help physicians deal with instabilities such as respiratory motion and soft tissue shift that are inherent in abdominal interventions. In addition to the 3D display of the needle and tumours, we adapted the system for the abdominal applications and incorporated a process to correct the mismatch in needle path between MRI and US. The preliminary results of phantom and animal experiments indicated that the proposed method could combine the advantages of both MRI and US. The time required to determine the optimal needle insertion path by using this system was significantly less than that required when either US or MRI guidance alone was employed. The developed system was applied in two patients who underwent PEIT therapy, and its clinical feasibility was partially confirmed.

Development and testing of an endoscopic pseudo-viewpoint alternating system.

PURPOSE: An endoscopic system is needed that presents informative images irrespective of the surgical situation and the number of degrees of freedom in endoscopic manipulation. This goal may be achieved with a virtual reality view for a region of interest from an arbitrary viewpoint. An endoscopic pseudo-viewpoint alternation system for this purpose was developed and tested. METHOD: Surgical experts and trainees from an endoscopic surgery training course at the minimally invasive surgery training center of Kyushu University were enrolled in a trial of a virtual reality system. The initial viewpoint was positioned to approximate the horizontal view often seen in laparoscopic surgery, with [Formula: see text] between the optical axis of the endoscope and the task surface. A right-to-left suturing task with right hand, based on a task from the endoscopic surgery training course, was selected for testing. We compared task outcomes with and without use of a new virtual reality-viewing system. RESULT: There was a 0.37 mm reduction in total error ([Formula: see text]) with use of the proposed system. Error reduction was composed of 0.1 mm reduction on the y-axis and 0.27 mm reduction on the x-axis. Experts benefited more than novices from use of the proposed system. Most subjects worked at a pseudo-viewpoint of around 34[Formula: see text]. DISCUSSION: Suturing performance improved with the new virtual reality endoscopic display system. Viewpoint alternation resulted in an overview that improved depth perception and allowed subjects to better aim the marker. This suggests the proposed method offers users better visualization and control in endoscopic surgery.

Alteration of the [Ca(2+)](i)-force relationship during the vasorelaxation induced by a Ca(2+) channel blocker SR33805 in the porcine coronary artery.

The mechanism of vasorelaxation induced by SR33805 was investigated by simultaneously monitoring the cytosolic Ca(2+) concentration ([Ca(2+)](i)) and force, and by determining level of myosin light chain (MLC) phosphorylation in the medial strip of the porcine coronary artery. SR33805 inhibited the sustained increases in [Ca(2+)](i) and force (IC(50); 3.2+/-1.0 and 49.4+/-27.5 nM, respectively) induced by 118 mM K(+)-depolarization. There was about a 10 fold difference in the inhibitory potency between [Ca(2+)](i) and force. SR33805 completely inhibited the [Ca(2+)](i) elevation induced by a thromboxane A(2) analogue, U46619 and histamine, at concentrations (1 microM) higher than those required for the complete inhibition of K(+)-depolarization induced [Ca(2+)](i) elevation. SR33805 had no effect on the [Ca(2+)](i) elevation induced by histamine or caffeine in the absence of extracellular Ca(2+). SR33805 caused a leftward shift of the [Ca(2+)](i)-force relationship of the contraction induced by cumulative application of extracellular Ca(2+) during 118 mM K(+)-depolarization. The relationship between [Ca(2+)](i) and MLC phosphorylation also shifted to the left by SR33805, while the relationship between MLC phosphorylation and force remained unaffected. In conclusion, SR33805 caused an apparent leftward shift of the [Ca(2+)](i)-force relationship, accompanied by a greater degree of MLC phosphorylation for a given level of [Ca(2+)](i). The mechanism of this leftward shift, however, still remains to be elucidated.

The mechanism for the contraction induced by leukotriene C4 in guinea-pig taenia coli.

The mechanism underlying the LTC(4)-induced contraction of guinea-pig taenia coli was determined using the simultaneous measurements of [Ca(2+)](i) and force in whole muscle preparations. Additional experiments were performed in receptor coupled permeabilized preparation. For comparison purposes, the contraction which was induced by a typical G-protein mediated agonist, carbachol was also characterized. LTC(4) induced a contraction in the guinea-pig taenia coli in a concentration-dependent manner. The maximal response was obtained at 100 nM and the EC(50) value was 5.4+/-1.9 nM. Both LTC(4) and carbachol induced increases in [Ca(2+)](i) and force. The maximum force induced by 100 nM LTC(4) was significantly smaller than that induced by 10 microM carbachol, although an increase in [Ca(2+)](i) produced by both agonists was similar. In the permeabilized preparations, carbachol, but not LTC(4), induced an additional force development at a fixed Ca(2+) concentration. LTC(4) induced no increase in [Ca(2+)](i) and force in the Ca(2+)-free solution, while carbachol induced transient increases in both [Ca(2+)](i) and force in a Ca(2+)-free solution. Both diltiazem and SK&F 96365 significantly inhibited the LTC(4)- and carbachol-induced increases in [Ca(2+)](i) and force in normal PSS. The inhibitory pattern of [Ca(2+)](i) by these drugs was also similar. We thus conclude that LTC(4) induces the contraction of the guinea-pig taenia coli mainly through Ca(2+) influx via both the diltiazem-sensitive and SK&F 96365-sensitive Ca(2+) channels, without affecting either the Ca(2+)-sensitivity or the intracellular Ca(2+) release. These results indicated that the mechanism underlying the LTC(4)-induced contraction differs greatly from that for conventional G-protein mediated agonists, such as carbachol.

Development of a colon endoscope robot that adjusts its locomotion through the use of reinforcement learning.

PURPOSE: Fibre optic colonoscopy is usually performed with manual introduction and advancement of the endoscope, but there is potential for a robot capable of locomoting autonomously from the rectum to the caecum. A prototype robot was designed and tested. METHODS: The robot colonic endoscope consists in a front body with clockwise helical fin and a rear body with anticlockwise one, both connected via a DC motor. Input voltage is adjusted automatically by the robot, through the use of reinforcement learning, determining speed and direction (forward or backward). RESULTS: Experiments were performed both in-vitro and in-vivo, showing the feasibility of the robot. The device is capable of moving in a slippery environment, and reinforcement learning algorithms such as Q-learning and SARSA can obtain better results than simply applying full tension to the robot. CONCLUSIONS: This self-propelled robotic endoscope has potential as an alternative to current fibre optic colonoscopy examination methods, especially with the addition of new sensors under development.

Development of a robotic endoscope that locomotes in the colon with flexible helical fins.

The purpose of this study was to develop a robotic endoscope that is low invasive, easy to operate and capable of locomotion from the rectum to the appendix in the human body. We believe that it would contribute to relieving pain in patients. We therefore developed a robotic endoscope that consists of a front and rear body with clockwise and anticlockwise helical fins, respectively. The front and rear bodies are connected via a DC motor. This robot moves forward in the colon by rotating the front body in the clockwise direction and the rear body in the anticlockwise direction. In addition, the radius of each helical fin can be changed by blowing air into a balloon implemented under each fin using an air compressor. Before experiments with animals, we performed experiments to evaluate the mechanical performance and safety of the robot. We confirmed that the maximum radius of the fins was less than the maximum radius of the colon by blowing air continuously into the balloons. We then confirmed that the robot can locomote in the colon without invasion of scratch and make short hole by performing an in-vivo experiment in live swine.

A case of an inflammatory myofibroblastic tumor in the lung which expressed TPM3-ALK gene fusion.

We herein describe a 4-year-old boy who after being treated for pneumonia showed an abnormal shadow at the hilus of the right lung on chest X-rays with continued inflammatory findings in his laboratory data. CT and MR investigations suggested the existence of a neoplasm at that site. An open biopsy was thus performed for a definite diagnosis. The histological findings and the expression of TPM3-ALK fusion gene confirmed a diagnosis of an inflammatory myofibroblastic tumor. A right upper and middle lobectomy including the tumor was thus performed for a complete resection. In addition to the histological diagnosis, the detection of the tumor specific fusion gene provided objective evidence in making a diagnosis.

Robotic laparoscopic distal gastrectomy: a comparison of the da Vinci and Zeus systems.

BACKGROUND: The robotic surgical systems working on a master-slave principle have been developed and used in the worldwide in cardiac, urologic, and general surgery. METHODS: The two robotic systems, the da Vinci and the Zeus Robotic Surgical System (Intuitive Surgical, Calif., USA), were compared with the aim of evaluating operative feasibility and technical efficacy in distal gastrectomy. RESULTS: During laparoscopic gastrectomy, the da Vinci System (n = 2) had a shorter total operative time (445 versus 656 minutes; p = 0.09) and less blood loss (65 versus 277 mL; p = 0.08) compared with the Zeus System (n = 3). The articulated instruments of both systems were useful in lymph node dissection, isolation of vessels in fat tissue, ligation of vessels, and intraabdominal anastomosis of the gastrointestinal tract. Robotic laparoscopic procedures can be performed effectively using either the da Vinci or Zeus System. CONCLUSION: In this limited study, the robotic instruments, especially those of da Vinci system, made it easier to complete tissue dissection including lymph nodes, complicated endoscopic anastomoses, and ligatures in a closed cavity.

Synthesis for an electrooptic light scanner with an arbitrary beam shape.

Two methods are described for synthesizing the electrooptic light scanner with an arbitrarily prescribed one-dimensional spatial distribution of the light beam. The electrooptic light scanner is constructed by a series of cascaded stages, each stage containing a natural-birefringent electrooptic crystal with an inclination angle between opposite faces. One method is realized by a set of cascaded stages, each of which contains a polarizer, electrooptic crystal, optical compensator, and analyzer; and the other method by a multistage construction that is inserted between the input and output polarizers, each stage being composed of only an electrooptic crystal and optical compensator. Two examples for each method are given to illustrate the synthesis procedures.