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Ultraviolet (UV) irradiation is a major environmental hazard that leads to acute and chronic reactions in the skin. Chronic exposure to UV irradiation causes premature skin aging(photoaging), which is characterized clinically wrinkle, laxity, coarseness, mottled pigmentation, rough skin textures. The hairless mouse has been used as an experimental model of the effects of chronic UV irradiation that induce solar damage. Many investigators have reported qualitative and quantitative changes in vivo resembling the damage that occurs to human skin. Also, a number of genes have been reported to be involved in the response to UV irradiation and modulation of gene expression during photoaging is now quite documented. However, these data are concentrated on a limited number of well-known genes and consequently limited in scope. To identify differential immune related gene expressions in photoaging skin after UVB irradiation, SKH-1 hairless mice were irradiated topically with UVB and the irradiation dose was increased weekly by 1 MED (Minimal erythemal dose) to 4 MED, and then maintained at 3-4 MED until 15 weeks. cDNA microarray technology was utilized to examine transcriptional responses to UV irradiation in mice skin. Especially, there were significant changes of the gene expression in the MMP-13, laminin(beta), procollagen, ccl3, ccl4, cxcl10, ccl9, p16, caspase 9 etc in the skin irradiated with UVB. These results describe several biological processes previously not known to be affected by UV irradiation. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to compare the dimensional accuracy, translucency, and biaxial flexural strength of milled zirconia (MZ) versus 3D-printed zirconia (PZ) discs., Materials & Methods: A circular disc measuring 14.0 mm in diameter and 1.20 mm in thickness was designed using computer-aided design (CAD) software. The resulting standard tessellation language (STL) file was used both as a control and to fabricate 36 zirconia (3Y-TZP) disc specimens (n = 36): 18 were milled (group MZ) and 18 were 3D-printed (group PZ). The diameter and thickness of each disc were measured using a digital caliper. Translucency was evaluated using a calibrated dental colorimeter. The flexural strength was determined using the piston-on-three-ball biaxial flexure test. All measurements were done by one blinded examiner. The statistical significance level was set to α = 0.05., Results: The MZ discs had significantly more accurate dimensions than the PZ discs in both diameter and thickness when compared to the control CAD software-designed disc. The MZ discs exhibited significantly higher translucency (translucency parameter (TP) = 16.95 ±0.36 vs. 9.24 ±1.98) and biaxial flexural strength (996.16 ±137.37 MPa vs. 845.75 ±266.16 MPa) than the PZ discs. Finally, MZ possessed a significantly higher Weibull modulus relative to PZ., Conclusions: The results showed that the milled specimens achieved better dimensional accuracy and were more translucent, stronger, and less prone to failure than printed specimens., (© 2023 by the American College of Prosthodontists.)

Objective: To compare four different types of monolithic zirconia crowns in terms of survival rate and fracture resistance after thermocycling and/or thermo-mechanical loading in a chewing simulator., Methods: Partially stabilized zirconia (PSZ) crowns with fiber-reinforced resin die assemblies (n = 80) were fabricated using: multi-yttria-layered 5Y-PSZ/3Y-PSZ, multi-yttria-layered 5Y-PSZ/4Y-PSZ, monolithic 4Y-PSZ, and monolithic 3Y-PSZ as control (n = 20). Half of the samples in each group were subjected to thermo-mechanical loading under 110 N, 1.4 Hz, 1.2 million cycles with simultaneous thermocycling (10,000 cycles, 5-55°C). The other half were subjected to thermocycling alone. The samples were loaded to failure to measure their fracture resistance. The data were analyzed using by two-way ANOVA and Tukey's HSD post-hoc test (α = 0.05)., Results: All specimens survived the aging protocols. The yttria content significantly affected the fracture resistance of the crowns (p < 0.0001). The mean fracture resistance, from highest to lowest: 3Y-PSZ, 4Y-PSZ, followed by the two multi-yttria-layered systems. The mean difference between the two multi-yttria-layered systems were not statistically significant (p = 0.98). The mechanical loading protocol did not affect the mean fracture resistance within each group (p = 0.18)., Conclusions: Within each group, there was no difference in fracture resistance after thermocycling alone and thermo-mechanical loading. However, increasing the yttria concentration at the occlusal third of the crown decreased its fracture resistance., Clinical Significance: The term "monolithic zirconia" alone without specifying the actual yttria content is misleading. This term represents different materials with different mechanical properties. The yttria content has an inverse relationship with the fracture resistance of zirconia crowns. The fracture resistance of multi-layer zirconia crowns is determined by the amount of the weaker zirconia phase at the occlusal part of the restoration rather than enforced by the stronger zirconia at the cervical part of the crown., (© 2022 Wiley Periodicals LLC.)

Bariatric surgery is an effective treatment for morbid obesity and its metabolic related comorbidities; type 2 diabetes, hypertension and hyperlipidaemia. 1 However, the literature is scarce regarding the long-term outcome after bariatric surgery, especially among multi-ethnic Asian populations. Considering the growing number of bariatric metabolic surgeries in Asia, we have attempted to provide a regional perspective on 5-year long-term clinical outcomes post bariatric surgery in Singapore. Between 2010 and 2016, all bariatric operative cases were included, and these comprised: laparoscopic sleeve gastrectomy (LSG), 393; laparoscopic Roux-En-Y gastric bypass (RYGB), 125; laparoscopic mini-gastric bypass (MGB), 43. The primary outcome measure was the percentage of excess weight loss (% EWL) at 6 months, 1, 2, 3, 4 and 5 years, with % remission of type 2 diabetes mellitus (T2DM) at 1 year following LSG (49.7%, 61.2%, 56.1%, 47.8%, 40.8% and 47.3%; 82.2%), RYGB (60.2%, 62.1%, 57.6%, 50.1%, 48.7% and 47.7%; 86.9%) and MGB (58%, 68.1%, 62.7%, 66.2%, 64.0%, 65.2%; 71.9%). In conclusion, MGB and RYGB showed the greatest % EWL at 5 years and are recommended for moderate T2DM. LSG is an effective bariatric operation with a high % EWL up to 2 years, and a high remission rate of mild T2DM. The remission rate of T2DM was equally high in all 3 surgical groups, independent of ethnic differences., (© 2018 John Wiley & Sons Ltd.)

Although major progress has been achieved in research and development of antipsychotic medications for bipolar disorder (BPD), knowledge of the molecular mechanisms underlying this disorder and the action of atypical antipsychotics remains incomplete. The levels of microRNAs (miRNAs)-small non-coding RNA molecules that regulate gene expression, including genes involved in neuronal function and plasticity-are frequently altered in psychiatric disorders. This study aimed to examine changes in miRNA expression in bipolar mania patients after treatment with asenapine and risperidone. Using a miRNA microarray, we analyzed miRNA expression in the blood of 10 bipolar mania patients following 12 weeks of treatment with asenapine or risperidone. Selected miRNAs were validated by using real-time PCR. A total of 16 miRNAs were differentially expressed after treatment in the asenapine group, 14 of which were significantly upregulated and the other two significantly downregulated. However, all three differentially expressed miRNAs in the risperidone group were downregulated. MiRNA target gene prediction and gene ontology analysis revealed significant enrichment for pathways associated with immune system response and regulation of programmed cell death and transcription. Our results suggest that candidate miRNAs may be involved in the mechanism of action of both antipsychotics in bipolar mania. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Stents are promising medical devices widely used in the prevention of cerebral aneurysm rupture. As the performance of stents depends on their mechanical properties and cell configuration, the aim of this study was to optimize the stent design and test the hemodynamic properties by using computational solid mechanics and computational fluid dynamics. In order to test their performance, computer-based cerebral aneurysm models that mimic the conditions present after implantation into the human brain were tested. The strut configuration selected was the closed-cell type, and nitinol was chosen as the material for stent manufacture because the innate characteristics of this material increase stent flexibility. Three ideal sample stent types with different cell configurations were manufactured. Computational solid mechanics analysis of the sample stents showed over 30% difference in flexibility between stents. Furthermore, using a cerebral aneurysm model simulation, we found that the stents eased the hemodynamic factors of the cerebral aneurysm and lessened the flow velocity influx into the sac. A decrease in flow velocity led to a 50-60% reduction in wall shear stress, which is expected to prevent aneurysm rupture under clinical conditions. Stent design optimization was carried out by simulation and electropolishing. Corrosion resistance and surface roughness were evaluated after electropolishing performed under variable conditions, but 40 V and 10 s were the most optimal., (Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

The aim of this meta-analysis was to determine whether pulsatile perfusion during cardiac surgery has a lesser effect on renal dysfunction than nonpulsatile perfusion after cardiac surgery in randomized controlled trials. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were used to identify available articles published before April 25, 2014. Meta-analysis was conducted to determine the effects of pulsatile perfusion on postoperative renal functions, as determined by creatinine clearance (CrCl), serum creatinine (Cr), urinary neutrophil gelatinase-associated lipocalin (NGAL), and the incidences of acute renal insufficiency (ARI) and acute renal failure (ARF). Nine studies involving 674 patients that received pulsatile perfusion and 698 patients that received nonpulsatile perfusion during cardiopulmonary bypass (CPB) were considered in the meta-analysis. Stratified analysis was performed according to effective pulsatility or unclear pulsatility of the pulsatile perfusion method in the presence of heterogeneity. NGAL levels were not significantly different between the pulsatile and nonpulsatile groups. However, patients in the pulsatile group had a significantly higher CrCl and lower Cr levels when the analysis was restricted to studies on effective pulsatile flow (P < 0.00001, respectively). The incidence of ARI was significantly lower in the pulsatile group (P < 0.00001), but incidences of ARF were similar. In conclusion, the meta-analysis suggests that the use of pulsatile flow during CPB results in better postoperative renal function., (Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

The aim of this study was to determine whether pulsatile or nonpulsatile perfusion had a greater effect on pulmonary dysfunction in randomized controlled trials. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were used to identify available articles published before April 13, 2013. A meta-analysis was conducted on the effects of pulsatile perfusion on postoperative pulmonary function, intubation time, and the lengths of intensive care unit (ICU) and hospital stays. Eight studies involving 474 patients who received pulsatile perfusion and 496 patients who received nonpulsatile perfusion during cardiopulmonary bypass (CPB) were considered in the meta-analysis. Patients receiving pulsatile perfusion had a significantly greater PaO2 /FiO2 ratio 24 h and 48 h post-operation (P < 0.00001, both) and significantly lower chest radiograph scores at 24 h and 48 h post-operation (P < 0.00001 and P = 0.001, respectively) compared with patients receiving nonpulsatile perfusion. The incidence of noninvasive ventilation for acute respiratory insufficiency was significantly lower (P < 0.00001), and intubation time and ICU and hospital stays were shorter (P = 0.004, P < 0.00001, and P < 0.00001, respectively) in patients receiving pulsatile perfusion during CPB compared with patients receiving nonpulsatile perfusion. In conclusion, our meta-analysis suggests that the use of pulsatile flow during CPB results in better postoperative pulmonary function and shorter ICU and hospital stays., (Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

Background: Although endoscopic resection is widely accepted as the curative treatment modality for early gastric cancer, secondary metachronous cancer may subsequently develop in the residual gastric mucosa. The preventive effect of Helicobacter pylori eradication on the development of metachronous gastric cancer in such cases remains controversial. The aim of this study was to determine the effect of H. pylori eradication on the development of metachronous gastric cancer after endoscopic resection of gastric neoplasm by a meta-analysis of all relevant studies., Materials and Methods: We performed a systematic literature search of PubMed, EMBASE, Google Scholar, and the Cochrane Library without language restrictions through March 31, 2014. We included all relevant articles, including prospective, observational, and retrospective studies. Pooled estimates (odds ratios with 95% confidence intervals) were obtained using a random effects model., Results: Thirteen studies were considered to be appropriate for this meta-analysis. Compared with the control group, the pooled odds ratio in the eradication group was 0.42 (95% confidence interval, 0.32-0.56), and there was no heterogeneity across the studies (p = .853, I(2) = 0%). Subgroup analysis of three prospective trials also showed a lower incidence of metachronous cancer in the eradication group (odds ratio, 0.39; 95% confidence interval, 0.20-0.75). There was no evidence of publication bias in this meta-analysis., Conclusion: Helicobacter pylori eradication reduces the occurrence of metachronous gastric cancer in patients who have undergone endoscopic resection., (© 2014 John Wiley & Sons Ltd.)

We investigated global and regional effects of myocardial transplantation of human induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) in infarcted myocardium. Acute myocardial infarction (MI) was induced by ligation of left coronary artery of severe combined immunodeficient mice before 2 × 10(5) iMSCs or cell-free saline were injected into peri-infarcted anterior free wall. Sham-operated animals received no injection. Global and regional myocardial function was assessed serially at 1-week and 8-week by segmental strain analysis by using two dimensional (2D) speckle tracking echocardiography. Early myocardial remodelling was observed at 1-week and persisted to 8-week with global contractility of ejection fraction and fractional area change in saline- (32.96 ± 14.23%; 21.50 ± 10.07%) and iMSC-injected (32.95 ± 10.31%; 21.00 ± 7.11%) groups significantly depressed as compared to sham control (51.17 ± 11.69%, P < 0.05; 34.86 ± 9.82%, P < 0.05). However, myocardial dilatation was observed in saline-injected animals (4.40 ± 0.62 mm, P < 0.05), but not iMSCs (4.29 ± 0.57 mm), when compared to sham control (3.74 ± 0.32 mm). Furthermore, strain analysis showed significant improved basal anterior wall strain (28.86 ± 8.16%, P < 0.05) in the iMSC group, but not saline-injected (15.81 ± 13.92%), when compared to sham control (22.18 ± 4.13%). This was corroborated by multi-segments deterioration of radial strain only in saline-injected (21.50 ± 5.31%, P < 0.05), but not iMSC (25.67 ± 12.53%), when compared to sham control (34.88 ± 5.77%). Improvements of the myocardial strain coincided with the presence of interconnecting telocytes in interstitial space of the infarcted anterior segment of the heart. Our results show that localized injection of iMSCs alleviates ventricular remodelling, sustains global and regional myocardial strain by paracrine-driven effect on neoangiogenesis and myocardial deformation/compliance via parenchymal and interstitial cell interactions in the infarcted myocardium., (© 2014 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Recent advances in medical and device therapies in heart failure have improved the survival of patients with heart failure. However, due to the limited availability of suitable heart donors, left ventricular assist devices (LVADs) have become an important tool as a bridge-to-heart transplantation for patients with refractory heart failure in Singapore. We report our experience with the HeartMate II (HMII) LVAD (Thoratec Corporation, Pleasanton, CA, USA) as a bridge-to-heart transplant in our center from 2009 to 2012. This was a retrospective review of 23 consecutive patients who underwent HMII LVAD implantation in our center between May 2009 and December 2012. All patients were classified as Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) levels 1 to 3 and underwent LVAD implantation as a bridge-to-heart transplant. There were 17 male and 6 female patients. The mean age was 43.6 years old (range 14 to 64). The etiologies of heart failure included ischemic heart disease [8], idiopathic dilated cardiomyopathy [11], viral myocarditis [2], and chemotherapy-induced cardiomyopathy [2]. Nine patients were INTERMACS level 1, 12 patients level 2, and two patients level 3. All patients successfully underwent HMII LVAD implantation. There was no mortality within the first 30 postoperative days. Postoperative complications included stroke with full neurological recovery (21.7%), mediastinal infection (21.7%), cardiac tamponade or mediastinal collection requiring reopening of the chest (39.1%), cardiac arrhythmia (13.0%), and pump thrombosis with pump replacement (4.3%). All patients were discharged from hospital after LVAD implantation. Three patients experienced driveline infections during outpatient follow-up. There were 19 readmissions due to the following conditions: sub-therapeutic anticoagulation (13.0%), gastrointestinal bleeding (13.0%), suspected pump thrombosis (13.0%), transient ischemic attack (8.7%), arrhythmia (8.7%), congestive cardiac failure due to severe aortic regurgitation (8.7%), right ventricular failure (4.3%), rhabdomyolysis (4.3%), and hematuria (4.3%). Post-LVAD implantation, 20 patients were functionally New York Heart Association (NYHA) class I, while 3 reported NYHA III symptoms. Three patients were successfully bridged to heart transplantation. One patient was successfully explanted 11 months after LVAD implantation. There were two mortalities during the follow-up period. The average duration of LVAD support was 522 days (range 47 to 1316 days). The HeartMate II LVAD has proven to be effective in our Asian population. Driveline infection rate remains low even in the tropical hot, humid climate in Singapore. With more patients ending up on extended periods of LVAD support, increased emphasis in the detection and management of long-term complications of ventricular assist devices will be needed., (Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

This study seeks to improve the mechanical performance of stents by conducting reliability performance testing and finite element method (FEM)-based simulations for coronary stents. Three commercially available stent designs and our own new design were tested to measure the factors affecting performance, specifically foreshortening, recoil, radial force, and flexibility. The stents used in the present experiments were 3 mm in working diameter and 18 mm of working length. The results of the experiments indicate that the foreshortening of stents A, B, C, and our new design, D, was equivalent to 2.25, 0.67, 0.46, and 0.41%, respectively. The recoil of stents A, B, C, and D was 6.00, 4.35, 3.50, and 4.36%, respectively. Parallel plate radial force measurements were A, 3.72 ± 0.28 N; B, 3.81 ± 0.32 N; C, 4.35 ± 0.18 N; and D, 4.02 ± 0.24 N. Radial forces determined by applying uniform pressure in the circumferential direction were A, 28.749 ± 0.81 N; B, 32.231 ± 1.80 N; C, 34.522 ± 3.06 N; and D, 42.183 ± 2.84 N. The maximum force of crimped stent at 2.2-mm deflection was 1.01 ± 0.08 N, 0.82 ± 0.08 N, 0.92 ± 0.12 N, and 0.68 ± 0.07 N for each of stents A, B, C and D. The results of this study enabled us to identify several factors to enhance the performance of stents. In comparing these stents, we found that our design, stent D, which was designed by a collaborative team from seven universities, performed better than the commercial stents across all parameter of foreshortening, recoil, radial force, and flexibility., (© 2013, Copyright the Authors. Artificial Organs © 2013, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

The inhibitory effect of propofol on platelet aggregation remains unclear, and studies on the subject disagree. Furthermore, although propofol infusions are widely used for general anesthesia and as sedatives for patients in intensive care units, little information is available on its concentration- and time-related effects on platelet aggregation. Here, the authors investigated the in vitro effect of propofol, at concentrations required for sedation and general anesthesia, on platelet aggregation after 1, 2, or 3 h. Blood from healthy volunteers (n = 9) was incubated at propofol plasma concentrations of 0, 2, 4, and 10 μg/mL in a water bath at 37°C. Platelet aggregation was measured using a platelet function analyzer (PFA-100) after 1, 2, or 3 h of incubation. Times to occlude collagen/epinephrine (CEPI) or collagen/adenosine 5'-diphosphate (CADP)-coated membranes (closure times, CTs) were measured. The CEPI and CADP CTs of non-incubated blood were 125.6 ± 19.5 s and 93.0 ± 12.2 s, respectively, and no significant difference in CEPI CTs was observed at propofol plasma concentrations of 0, 2, 4, and 10 μg/mL after incubation for 1, 2, or 3 h. CADP CTs were comparable at propofol concentrations of 0, 2, 4, and 10 μg/mL at each incubation time. These findings suggest that propofol at concentrations required for sedation and general anesthesia has no inhibitory effect on platelet aggregation after 3 h of incubation., (© 2012, Copyright the Authors. Artificial Organs © 2012, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

In 2002, the paracorporeal pulsatile electro-mechanical pneumatic ventricular assist device (VAD) began to be developed by the Korea Artificial Organ Center at Korea University under a Health & Medical Technology Research and Development program which finished in 2008. In vitro durability testing was conducted on the paracorporeal pulsatile pneumatic VAD to determine device durability and to evaluate device failures. The 1- and 2-year reliability of the paracorporeal pulsatile pneumatic VAD was shown to be 91.2% and 54.9%, respectively, with an 80% confidence level. Failure modes were analyzed using fault tree analysis, with customized software continuously acquiring data during the test period. After this period, 21 in vivo animal tests were done, with 14 cases of left atrium to left ventricle (LV) inflow cannulation (36Fr)/outflow grafting to descending aorta, and seven cases of apex cannulation of LV to descending aorta (12 mm). The longest postoperative day (182 days) in Korea was recently recorded in in vivo animal testing (bovine, 90 kg, male, 3.5-4.0 L/min flow rate, and 55 bpm)., (© 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.)

In this study, we investigated the differences between pulsatile cardiopulmonary bypass (CPB) procedure and nonpulsatile CPB procedure in terms of their effects on hemolysis and deformability of red blood cells (RBCs) under various shear stress conditions. In order to research the effects on hemolysis and deformability, four parameters--free hemoglobin (fHb) concentration, normalized index of hemolysis (NIH), deformability index (DI) of RBCs, and elongation index of RBCs--have been deeply investigated. For these investigations, two randomly assigned adult mongrel dog groups-nonpulsatile group (NP, n = 6) and pulsatile group (P, n = 6)--were examined. According to our results, both types of perfusion did not show any statistical differences in terms of the concentrations of fHb as well as NIH. In addition, there were no significant differences in RBC deformability between perfusion types within an operation time of 3 h. Therefore, our studies suggest that pulsatile perfusion has no significant difference from nonpulsatile perfusion in terms of hemolysis and deformability of RBCs.

The nonpulsatile blood flow obtained using standard cardiopulmonary bypass (CPB) circuits is still generally considered an acceptable, nonphysiologic compromise with few disadvantages. However, numerous reports have concluded that pulsatile perfusion during CPB achieves better multiorgan response postoperatively. Furthermore, pulsatile flow during CPB has been consistently recommended in pediatric and high-risk patients. However, most (80%) of the total hemodynamic energy generated by a pulsatile pump is absorbed by the components of the extracorporeal circuit and only a small portion of the pulsatile energy is delivered to the patient. Therefore, we considered that optimizations of CPB unit and extracorporeal life support (ECLS) system circuit components were needed to deliver sufficient pulsatile flow. In addition, energy equivalent pressure, surplus hemodynamic energy, and total hemodynamic energy, calculated using pressure and flow waveforms, were used to evaluate the pulsatilities of pulsatile CPB and ECLS systems.

The bellows-type pneumatic ventricular assist device (VAD) generates pneumatic pressure with compression of bellows instead of using an air compressor. This VAD driver has a small volume that is suitable for portable devices. However, improper pneumatic pressure setup can not only cause a lack of adequate flow generation, but also cause durability problems. In this study, a pneumatic pressure regulation system for optimal operation of the bellows-type VAD has been developed. The optimal pneumatic pressure conditions according to various afterload conditions aiming for optimal flow rates were investigated, and an afterload estimation algorithm was developed. The developed regulation system, which consists of a pressure sensor and a two-way solenoid valve, estimates the current afterload and regulates the pneumatic pressure to the optimal point for the current afterload condition. Experiments were performed in a mock circulation system. The afterload estimation algorithm showed sufficient performance with the standard deviation of error, 8.8 mm Hg. The flow rate could be stably regulated with a developed system under various afterload conditions. The shortcoming of a bellows-type VAD could be handled with this simple pressure regulation system.

In this study, we developed a small pneumatic actuator that can be used as an extracorporeal biventricular assist device. It incorporated a bellows-transforming mechanism to generate blood-pumping pressure. The cylindrical unit is 88 +/- 0.1 mm high, has a diameter of 150 +/- 0.1 mm, and weighs 2.4 +/- 0.01 kg. In vitro, maximal outflow at the highest pumping rate (PR) exceeded 8 L/min when two 55 mL blood sacs were used under an afterload pressure of 100 mm Hg. At a pumping rate of 100 beats per minute (bpm), maximal hydraulic efficiency was 9.34% when the unit supported a single ventricle and 13.8% when it supported both ventricles. Moreover, pneumatic efficiencies of the actuator were 17.3% and 33.1% for LVAD and BVAD applications, respectively. The energy equivalent pressure was 62.78 approximately 208.10 mm Hg at a PR of 60 approximately 100 bpm, and the maximal value of dP/dt during systole was 1269 mm Hg/s at a PR of 60 bpm and 979 mm Hg/s at a PR of 100 bpm. When the unit was applied to 15 calves, it stably pumped 3 approximately 4 L/min of blood at 60 bpm, and no mechanical malfunction was experienced over 125 days of operation. We conclude that the presently developed pneumatic actuator can be utilized as an extracorporeal biventricular assist device.

Background: Dramatic changes in the prevalence and pattern of gastrointestinal disease has taken place in Asia in recent years., Aim: To compare the prevalence of duodenal (DU) and gastric ulcers (GU), erosive oesophagitis (EO), gastric cancer (GCA) and oesophageal cancer (OCA) and Helicobacter pylori infection over a 10-year interval of time in a multiracial South-East Asian population., Methods: Endoscopy records of first time gastroscopy in the University of Malaya Medical Centre, Kuala Lumpur, Malaysia were reviewed for 1989/1990 and 1999/2000., Results: In the period of 1989-1990, 3252 records and in 1999-2000, 4615 records were analysed. Both DU (21.1-9.5%) and GU (11.9-9.4%) had decreased significantly (P < 0.001). EO had increased significantly from 2.0% to 8.4% (P < 0.001). Both GCA and OCA had declined in the 10-year interval. Helicobacter pylori prevalence had decreased from 51.7% to 30.3% (P < 0.001).The decrease in DU and GU was seen in all racial groups. The increase in EO was most marked in Indians and the decrease in GCA in Chinese. The proportion of H. pylori-associated DU and GU had also decreased with time., Conclusions: Peptic ulcers and H. pylori infection had declined over a 10-year period of time and showed an opposing time trend with EO, which had increased dramatically. Both GCA and OCA had declined in prevalence.

Spontaneous retinal activity has been implicated in the development of the topographic map in the superior colliculus (SC) but a direct demonstration that it reaches the colliculus is lacking. Here we investigate when the retinocollicular projection is capable of transmitting information from the retina in a marsupial mammal, the wallaby (Macropus eugenii). The projection develops postnatally, allowing in vivo analysis throughout development. Quantification of retinocollicular synaptogenesis has been combined with electrophysiology of the development and characteristics of retinocollicular transmission, including in vivo and in vitro recording in the same animals. Prior to postnatal day (P) 12-14 in vitro recording detected only presynaptic activity in retinal axons in the colliculus, in response to stimulation of the optic nerve. Postsynaptic responses, comprising both N-methyl-d-aspartate (NMDA) and non-NMDA responses, were first detected in vitro at P12-14 and retinal synapses were identified. In contrast, postsynaptic responses to optic nerve stimulation could not be detected in vivo until P39, around the time that retinal axons begin arborizing. Around this age density and numbers of total synapses began increasing in the retinorecipient layers of the colliculus. By P55-64, the numbers of retinal synapses had increased significantly and density and numbers of retinal and total synapses continued to increase up to P94-99. During this time the map is undergoing refinement and degenerating axons and synapses were present. The discrepancy between in vitro and in vivo onset of functional connections raises the question of when retinal activity reaches collicular cells in the intact, unanaesthetized animal and this will require investigation.

Aim: The role of high cholesterol-containing microdomains in the signal transduction cascade leading to the activation of volume-regulated anion channels (VRACs) was studied., Methods: Osmotic cell swelling-induced efflux of 125I- was determined in human epithelial Intestine 407 cells and in skin fibroblasts obtained from healthy controls or Niemann-Pick type C (NPC) patients. Cellular cholesterol content was modulated by pre-incubation with 2-hydroxypropyl-beta-cyclodextrin in the presence of acceptor lipid vesicles., Results: Osmotic cell swelling of human Intestine 407 cells leads to the rapid activation of a compensatory anion conductance. Treatment of the cells with cyclodextrin enhanced the response to submaximal hypotonic stimulation by approx. twofold, but did not further increase the efflux elicited by a saturating stimulus. In contrast, the volume-sensitive anion efflux was markedly inhibited when cholesterol-loaded cyclodextrin was used. Potentiation of the response by cholesterol depletion was maintained in caveolin-1 deficient Caco-2 colonocytes as well as in sphingomyelinase-treated Intestine 407 cells, indicating that cholesterol-rich microdomains are not crucially involved. However, treatment of the cells with progesterone, an inhibitor of NPC1-dependent endosomal cholesterol trafficking, not only markedly reduced the hypotonicity-provoked anion efflux, but also prevented its potentiation by cyclodextrin. In addition, the volume-sensitive anion efflux from human NPC skin fibroblasts was significantly smaller when compared with control fibroblasts., Conclusions: The results support a model of regulatory volume decrease involving recruitment of volume-sensitive anion channels from intracellular compartments to the plasma membrane.