Numerical analysis of a ground-source heat-pump system in traditional Japanese “Kyo-machiya” dwellings

Kyo-machiya, which is a traditional wooden dwelling in Kyoto, is generally equipped with a shallow well. The well water can be potentially utilized as a heat source with a geothermal heatpump system without incurring a high drilling cost. Hereby, more energy saving in the traditional dwelling can be realized with the heat-pump system. However, an appropriate technique to utilize geothermal heat from a shallow well has not been established yet in Japan. To promote the geothermal use, we have continued an experiment to evaluate the practicability of a simple geothermal heat-pump system installed in a shallow well since the winter of 2013. In this study, the condition of the water flow in the well was examined using the computational fluid dynamics (CFD) technique, and the velocity of flow of the groundwater into the well was also estimated. We show that constant buoyancy was generated because of the temperature difference due to the heat-pump operation. Based on the results, a three-dimensional heattransfer numerical analysis model, proposed in the previous study, was developed so that moisture transfer in the ground could be considered. Using the estimated buoyancy of the well water and the groundwater velocity, the calculated results seemed to reproduce the characteristic of the measured value. Furthermore, we show that the groundwater velocity has a large influence on the well water temperature

Precancerous Pyloric Gland Metaplasia in the Biliary Epithelium Associated with Congenital Biliary Dilatation in a Three-Month-Old Infant

Pyloric gland metaplasia in the biliary epithelium is a precancerous lesion and has been confirmed in patients with congenital biliary dilatation presenting with overt biliary tract cancer. A patient was found to have an intra-abdominal cyst on fetal ultrasonography and was born at 37 weeks of gestation with a body weight of 2,636 g. Abdominal distension and repeated vomiting appeared 2 days after birth. Congenital biliary dilatation was diagnosed by imaging, wherein the common bile duct was enlarged to 9–10 cm in size, and the surrounding organs were extensively compressed; however, there was no sign of pancreatitis or cholangitis. Biliary drainage was performed through the gallbladder at 6 days of age, but it was insufficient because of the narrow and twisted cystic duct and changed to common bile duct at 18 days to relieve the compression. Because the body weight gain was poor due to loss of large amount of bile, the dilated bile duct and gallbladder were resected and hepatic duct Roux-Y jejunostomy was performed at 115 days of age with 4,500 g of body weight. Intraoperative imaging showed a pancreaticobiliary maljunction, and the pancreatic enzyme activities of the bile in the biliary system were remarkably elevated. Histopathological examination revealed pyloric gland metaplasia in the gallbladder epithelium and cystic duct. The patient is now over 2 years old and has been doing well without any complications. Based on our experience, precancerous pyloric gland metaplasia of the biliary epithelium may already occur even in a 3-month-old infant presenting with congenital biliary dilatation

Comparisons of Postoperative Complications and Nutritional Status After Proximal Laparoscopic Gastrectomy with Esophagogastrostomy and Double-Tract Reconstruction

[Background] The purpose of this study was to compare postoperative complications and nutritional status between esophagogastrostomy and double-tract reconstruction in patients who underwent laparoscopic proximal gastrectomy, and assess the advantages of both surgical procedures. [Methods] Between 2010 and 2018, 47 cases underwent proximal gastrectomy with esophagogastrostomy (n = 23) or double-tract reconstruction (n = 24) at our institution for the treatment of clinical T1N0 adenocarcinoma located in the upper third of the stomach. Patient clinical characteristics, short-term outcomes, nutrition status, and skeletal muscle index were compared among the two groups. [Results] There was no significant difference between esophagogastrostomy and double-tract reconstruction in terms of operation time, blood loss, and length of postoperative hospital stay. Reflux symptoms and anastomotic stenosis were significantly higher in the esophagogastrostomy group compared with the double-tract reconstruction group (P < 0.001 and P = 0.004, respectively). There was no significant difference in anastomotic leakage, surgical site infection, and pancreatic fistula. For the nutritional status, the decrease rate of cholinesterase was significantly higher in the esophagogastrostomy group compared with the double-tract reconstruction group at 6 months (P = 0.008) There was no significant difference in the decrease rate of skeletal muscle mass index at 1 year after surgery. [Conclusion] Compared with esophagogastrostomy, double-tract reconstruction tends to have better short-term nutritional status and postoperative outcomes in terms of preventing the occurrence of gastroesophageal reflux and anastomosis stenosis. These findings suggest that double-tract reconstruction may be a useful method in laparoscopic proximal gastrectomy

The Combination of Prognostic Nutritional Indicator and Serum Carcinoembryonic Antigen is Useful in Predicting Postoperative Recurrence in Stage II Colorectal Cancer

[Background] The efficacy of adjuvant chemotherapy in stage II colorectal cancer (CRC) patients has not been clearly demonstrated. Therefore, identification of robust prognostic factors is crucial for the assessment of recurrence risk in stage II CRC and appropriate adjuvant treatment, in clinical practice. [Methods] We enrolled 135 colorectal adenocarcinoma patients who underwent proctocolectomies and had histologically diagnosed stage II CRC. [Results] Receiver operating characteristic (ROC) analysis, to evaluate the predictive ability of certain serum factors for CRC recurrence, indicated that the prognostic nutritional indicator (PNI), followed by serum carcinoembryonic antigen (CEA) level, were the strongest predictive metrics. Based on cutoff values from ROC analyses, patients were divided as follows; CEAHigh (≥ 4.55 ng/mL), CEALow (< 4.55 ng/mL), PNIHigh (≥ 47.72), and PNILow (< 47.72). The recurrence rates of patients with CEAHigh and PNILow, CEAHigh and PNIHigh, CEALow and PNILow, and CEALow and PNIHigh were 34.3%, 0%, 6.8%, and 2.6%, respectively (a significant difference at P < 0.0001). Logistic regression analysis revealed that the combination of serum CEA level and PNI was an independent predictive indicator of tumor recurrence after operation in stage II CRC patients. The 5-year disease specific survival rates of patients with CEALowPNIHigh, CEAHighPNIHigh, CEALowPNILow, CEAHighPNILow were 100%, 100%, 97.4%, and 77.5%, respectively (P < 0.0001). [Conclusion] The combination of CEA and PNI was useful in predicting postoperative recurrence in stage II CRC patients

Comparative Study of Complications in CV Catheter Insertion for Pediatric Patients: Real-time Ultrasound-guided Versus Venography-guided Approach

[Background]Tunneled central venous catheters (CVC), called Broviac/Hickman catheter, are widely used in the long-term treatment of pediatric patients. Recently, the percutaneous approach for CVC insertion has become dominant as a less invasive intervention. In this study, we reviewed the mechanical and delayed complications according to different procedures of CVC insertion and assessed the risk factors for complications in CVC insertions for pediatric patients. [Methods]A total of 159 pediatric patients (85 males and 74 females) were included in this study. Primary reasons for indication of CVC settlement were hemato-oncologic disorders (66 cases, 42%), malignant solid tumors (30, 19%) and other benign diseases (63, 40%). CVC insertion was performed with surgical venous cutdown (CD) in 51 patients (32%), with real-time ultrasound-guided puncture (RTUS) in 57 (36%), and venography-guided puncture (VG) in 49 (31%). [Results]CD was dominantly selected and the frequency of venipuncture increased respective to the increased age of patients. RTUS was dominantly selected for one to four year old patients and VG was dominant in 5 to 15 year old patients. Some types of mechanical complication were observed in 4 of 159 (2.5%) and some delayed types were observed in 66 of 159 cases (42%). No mechanical complications occurred in cases with CD and RTUS; on the other hand, 3 (6%) of 49 insertions with VG were observed. However, we could not show any significant risk factors for the mechanical complications. In the meantime, delayed complications and premature removal were significantly observed in patients under 5 years old. [Conclusion]RTUS is superior to our conventional VG considering less frequent mechanical complications. High frequent delayed complication and premature removal should be considered, especially for patients under 5 years old

Structures and mechanisms of actin ATP hydrolysis

The major cytoskeleton protein actin undergoes cyclic transitions between the monomeric G-form and the filamentous F-form, which drive organelle transport and cell motility. This mechanical work is driven by the ATPase activity at the catalytic site in the F-form. For deeper understanding of the actin cellular functions, the reaction mechanism must be elucidated. Here, we show that a single actin molecule is trapped in the F-form by fragmin domain-1 binding and present their crystal structures in the ATP analog-, ADP-Pi-, and ADP-bound forms, at 1.15-Å resolutions. The G-to-F conformational transition shifts the side chains of Gln137 and His161, which relocate four water molecules including W1 (attacking water) and W2 (helping water) to facilitate the hydrolysis. By applying quantum mechanics/molecular mechanics calculations to the structures, we have revealed a consistent and comprehensive reaction path of ATP hydrolysis by the F-form actin. The reaction path consists of four steps: 1) W1 and W2 rotations; 2) PG–O3B bond cleavage; 3) four concomitant events: W1–PO3− formation, OH− and proton cleavage, nucleophilic attack by the OH− against PG, and the abstracted proton transfer; and 4) proton relocation that stabilizes the ADP-Pi–bound F-form actin. The mechanism explains the slow rate of ATP hydrolysis by actin and the irreversibility of the hydrolysis reaction. While the catalytic strategy of actin ATP hydrolysis is essentially the same as those of motor proteins like myosin, the process after the hydrolysis is distinct and discussed in terms of Pi release, F-form destabilization, and global conformational changes

Ruptured Small Intestinal Stromal Tumor Causing Concurrent Gastrointestinal and Intra-Abdominal Hemorrhage: A Case Report

Gastrointestinal stromal tumors (GISTs) originate from mesenchymal cells throughout the gastrointestinal tract. A common symptom is gastrointestinal hemorrhage; intra-abdominal hemorrhage is relatively rare. There are few reports of GIST presenting with both types of hemorrhage concurrently. A 77-year-old man was admitted to our hospital because of melena and anemia (Hb: 4.7 g/dL). Computed tomography revealed a small bowel tumor and high-density fluid in both the small intestine and the pelvic floor. We diagnosed a small intestinal tumor with concurrent gastrointestinal and intra-abdominal hemorrhage, and performed emergency surgery. The tumor arose from the small intestine and was ruptured. We found hemorrhage in the pelvic cavity and performed partial small intestine resection. Pathological findings revealed that the tumor was positive for c-Kit protein and was diagnosed as GIST. The patient was discharged from the hospital on postoperative day 9 and received imatinib 1 month postoperatively. We experienced a very rare case of ruptured GIST originating from the small intestine associated with both gastrointestinal and intra-abdominal hemorrhage. We also reviewed the relevant literature

Clinical Significance of Serum Antithrombin III Activity After Hepatectomy for Hepatocellular Carcinoma

[Background] As antithrombin III (AT-III) is produced in the hepatocytes, its serum activity decreases at the time of liver failure, in addition to ischemia reperfusion injury, vascular endothelial dysfunction, and disseminated intravascular coagulation (DIC). Here, we examined whether the serum AT-III value after hepatectomy could be a prognostic factor for hepatocellular carcinoma (HCC). [Methods] Of 141 patients who underwent hepatectomy for HCC, data for 101 patients in whom serum AT-III activity was measured on the first postoperative day were extracted. Patients with serum AT-III activity > 50% and ? 50% were assigned to high value (72 cases) and low value (29 cases) groups, respectively. We examined the clinical and prognostic differences between these two groups. [Results] The average age of enrolled patients (83 men and 18 women) was 68.0 years. The 5-year overall survival rate was 88% and 60% in the high and low value groups, respectively (P < 0.01). Furthermore, the 2-year relapse-free survival rate was 71% and 54% in the high and low value groups, respectively (P = 0.03). [Conclusion] This is the first study to demonstrate that serum AT-III levels on the first postoperative day may serve as a prognostic factor in HCC patients