Broad expansion of optical frequency combs by self-Raman scattering in coupled-cavity self-mode-locked monolithic lasers.

Broad expansion of optical frequency comb (OFC) by the self-Raman scattering is numerically analyzed and experimentally accomplished in a coupled-cavity self-mode-locked (SML) monolithic Yb:KGW laser. The gain medium is coated to achieve the monolithic SML operation and a partially reflective mirror is further exploited to form the coupled cavity and to multiply the repetition rate up to 128.9 GHz. With a coupled reflectivity of 95%, it is experimentally found that not only the first-order but also second-order stimulated Raman scattering (SRS) can be efficiently generated. The mode-locked OFC can be consequently expanded to reach approximately 8.4 THz, leading the pulse width to be as narrow as 53 fs. At the pump power of 8.7 W, the total output power for the fundamental and the first- and second-Stokes waves can be maintained at 1.6 W. The present exploration provides a promising way to generate the ultrahigh-repetition-rate broadband OFC via the simultaneous SML and SRS processes.

Monolithic dual-polarization self-mode-locked Nd:YAG 946-nm lasers: controlling beat frequency and observation of temporal chaos.

The self-mode-locked (SML) operation at 946 nm can be achieved with a monolithic Nd:YAG crystal when the pump power is above the threshold of the multiple-longitudinal-mode generation. The SML output is further found to include two orthogonal polarization components with a beat frequency coming from the birefringence effect in the laser crystal. The beat frequency can be widely adjusted in the range of 5-220 MHz by controlling the cooling temperature. The present experiment also confirms the theoretical prediction that the two-mode operation generally exhibits the chaotic dynamics when the frequency difference is sufficiently close to the relaxation frequency.

Analysis of the optimal temperature for the cryogenic monolithic Nd:YAG laser at 946-nm.

The optimal temperature for the cryogenic monolithic Nd:YAG laser at 946-nm is theoretically and experimentally analyzed. It is clear that decreasing temperature can considerably eliminate the thermal population at the lower laser level to enhance the quantum efficiency. However, the narrowing of the absorption bandwidth for the gain medium leads to a reduction of the effective absorption efficiency as the temperature is decreased. Consequently, an optimal temperature for the maximum output power is found to be in the range of approximately 120 K to 140 K. It is experimentally verified that employing a pump source with a narrower emission spectrum linewidth contributes a more efficient output for the cryogenic laser.

Synchronized self-mode-locked 1061-nm and 1064-nm monolithic Nd:YAG laser at cryogenic temperatures with two orthogonally polarized emissions: generation of 670 GHz beating.

A dual-wavelength self-mode-locked monolithic Nd:YAG laser at 1061 and 1064 nm is realized at cryogenic temperatures. At an incident pump power of 5.5 W, the total output power can reach 2.5 W and the mode-locked pulse width is 29 ps at a pulse repetition rate of 7.75 GHz. The synchronization of the dual-wavelength emissions leads to a beat frequency of 670 GHz in the individual mode-locked pulse. It is further discovered that the laser output consists of two orthogonally polarized components with a central frequency difference of 127 MHz. The central frequency difference between two orthogonal polarizations mainly arises from the external mechanical stress introduced by the copper holder for the laser crystal.

Mitochondrial DNA variants as genetic risk factors for Parkinson disease.

BACKGROUND AND PURPOSE: Investigation of the relationship between mitochondrial DNA (mtDNA) variants and Parkinson disease (PD) remains an issue awaiting more supportive evidence. Moreover, an affirming cellular model study is also lacking. METHODS: The index mtDNA variants and their defining mitochondrial haplogroup were determined in 725 PD patients and 744 non-PD controls. Full-length mtDNA sequences were also conducted in 110 cases harboring various haplogroups. Cybrid cellular models, composed by fusion of mitochondria-depleted rho-zero cells and donor mitochondria, were used for a rotenone-induced PD simulation study. RESULTS: Multivariate logistic regression analysis revealed that subjects harboring the mitochondrial haplogroup B5 have resistance against PD (odds ratio 0.50, 95% confidence interval 0.32-0.78; P = 0.002). Furthermore, a composite mtDNA variant group consisting of A10398G and G8584A at the coding region was found to have resistance against PD (odds ratio 0.50, 95% confidence interval 0.33-0.78; P = 0.001). In cellular studies, B4 and B5 cybrids were selected according to their higher resistance to rotenone, in comparison with cybrids harboring other haplogroups. The B5 cybrid, containing G8584A/A10398G variants, showed more resistance to rotenone than the B4 cybrid not harboring these variants. This is supported by findings of low reactive oxygen species generation and a low apoptosis rate in the B5 cybrid, whereas a higher expression of autophagy was observed in the B4 cybrid particularly under medium dosage and longer treatment time with rotenone. CONCLUSIONS: Our studies, offering positive results from clinical investigations and cybrid experiments, provide data supporting the role of variant mtDNA in the risk of PD.

Assessing dengue infection risk in the southern region of Taiwan: implications for control.

Dengue, one of the most important mosquito-borne diseases, is a major international public health concern. This study aimed to assess potential dengue infection risk from Aedes aegypti in Kaohsiung and the implications for vector control. Here we investigated the impact of dengue transmission on human infection risk using a well-established dengue-mosquito-human transmission dynamics model. A basic reproduction number (R 0)-based probabilistic risk model was also developed to estimate dengue infection risk. Our findings confirm that the effect of biting rate plays a crucial role in shaping R 0 estimates. We demonstrated that there was 50% risk probability for increased dengue incidence rates exceeding 0.5-0.8 wk-1 for temperatures ranging from 26°C to 32°C. We further demonstrated that the weekly increased dengue incidence rate can be decreased to zero if vector control efficiencies reach 30-80% at temperatures of 19-32°C. We conclude that our analysis on dengue infection risk and control implications in Kaohsiung provide crucial information for policy-making on disease control.

Abundance and diversity of sulfate-reducing bacteria in the sediment of the Zhou Cun drinking water reservoir in Eastern China.

Sulfate-reducing bacteria (SRB) play an important role in the sediments of bay areas, estuaries, and lakes. However, information regarding the genetic diversity of SRB in the sediments of drinking water reservoirs is scarce. In this study, we collected sediment samples from different sites in the Zhou Cun drinking water reservoir between April and June 2012. To explore the genetic diversity of SRB, we used the most-probable-number (MPN) method, polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), and a cloning approach. The average content of acid-volatile sulfide at the deepest sampling site was 205.87 µg/g sediment. This result is often associated with a large abundance of SRB in the associated sediment. The highest MPN estimate (1.15 x 10(5) cells/g sediment) was detected in May at the deepest sampling site. The PCR-DGGE fingerprints of SRB based on the dissimilatory sulfite reductase beta subunit (dsrB) gene varied according to the different sampling sites and dates. The highest abundance of SRB in the sediments was predominantly found at the deepest sampling sites, as expected from the acid-volatile sulfide content. The dominant species were Desulfobulbus sp, Desulfobacterium sp, and uncultured sulfate-reducing bacteria. Redundancy analysis revealed that organic matter and the concentrations of nitrogen and phosphorus in the sediments were significantly correlated with the diversity of SRB communities present. The results of this study provide a better understanding of the sulfate-reducing microbial species in the sediments of the Zhou Cun drinking water reservoir.

Nd:YLF laser at cryogenic temperature with orthogonally polarized simultaneous emission at 1047 nm and 1053 nm.

A Nd:YLF laser at cryogenic temperature is demonstrated for the first time with orthogonally polarized simultaneous emission at 1047 nm and 1053 nm. By exploring the temperature dependence of the fluorescence and the absorption spectra from the Nd:YLF crystal, the feasibility of simultaneous emission at low temperature is achieved. Due to the local heating from the pump absorption, the optimal temperature with respect to the pump power for balancing output powers of simultaneous emission is thoroughly explored. At the optimal temperature of 138 K, the total output power of the simultaneous emission can reach 3.1 W at an incident pump power of 7.9 W, corresponding to the optical to optical slope efficiency up to 43%.

[Tanshinone â ¡A activates PI3K/AKT signaling pathway to inhibit the apoptosis of mice cochlear pericytes induced by high glucose].

Objective: To investigate whether tanshinone ⅡA can protect the apoptosis of mice cochlear pericytes induced by high glucose and its specific protective mechanism, so as to provide experimental evidence for the prevention and treatment of diabetic hearing loss. Methods: C57BL/6J male mice were used to prepare type 2 diabetes model, which were divided into normal (NG) group, diabetic (DM) group, diabetic+tanshinone ⅡA (HG+tanshinone ⅡA) group and tanshinone ⅡA group. Each group had 10 animals. Primary cochlear pericytes were divided into NG group, HG group (high glucose 35 mmol/L), HG+tanshinone ⅡA (1, 3, 5 µmol/L) group, HG+Tanshinone ⅡA+LY294002 (PI3K/AKT pathway inhibitor) group, LY294002 group, tanshinone ⅡA group and DMSO group. Auditory brainstem response (ABR) was used to measure hearing threshold. Evans blue was used to detect the permeability of blood labyrinth barrier in each group. TBA methods were used to detect oxidative stress levels in various organs of mice. Morphological changes of stria vascularis were observed by hematoxylin-eosin staining (HE). Evans blue was used to detect the vascular labyrinth barrier permeability in cochlea. The expression of apoptosis protein in stria vascularis pericytes was observed by immunofluorescence. Pericytes apoptosis rate was observed by flow cytometry. DCFH-DA was combined with flow cytometry to detect intracellular ROS content, and Western blot was used to detect the expression of apoptotic proteins (Cleaved-caspase3, Bax), anti-apoptotic proteins (BCL-2) and pathway proteins (PI3K, p-PI3K, AKT, p-AKT). SPSS software was used for statistical analysis. Independent sample t test was performed, and P<0.05 was considered statistically significant. Results: Animal experiments: Tanshinone ⅡA decreased the hearing threshold of DM group [(35.0±3.5) dB SPL vs. (55.3±8.1) dB SPL] (t=4.899, P<0.01), decreased the oxidative stress level in cochlea (t=4.384, P<0.05), improved the structure disorder, atrophy of cochlea vascular lines, vacuole increased phenomenon. Tanshinone ⅡA alleviated the increased permeability of the blood labyrinth barrier [Evans blue leakage (6.84±0.27) AU vs. (8.59±0.85) AU] in the cochlea of DM mice (t=2.770, P<0.05), reversed the apoptotic protein: Caspase3 (t=4.956, P<0.01) and Bax (t=4.388, P<0.05) in cochlear vascularis. Cell experiments: Tanshinone ⅡA decreased intracellular ROS content in a concentration-dependent way (t=3.569, P<0.05; t=4.772, P<0.01; t=7.494, P<0.01); Tanshinone ⅡA decreased apoptosis rate and apoptotic protein, and increased the expression of anti-apoptotic protein, p-PI3K/PI3K and p-AKT/AKT in concentration-dependent manner (all P values<0.05); LY294002 reversed the protective effect of tanshinone ⅡA on pericytes apoptosis (all P values<0.05). Conclusion: Tanshinone ⅡA can inhibit the apoptosis of cochlear pericytes induced by high glucose by reducing oxidative stress level and activating PI3K/AKT signaling pathway under high glucose environment, thus playing a protective role in diabetic hearing loss.

[Effect of microvascular pericytes of cochlear stria vascularis on endothelial cell permeability in C57BL/6J mice].

Objective: To study the changes in the permeability of the blood labyrinth barrier of the aging cochlea in mice, and to establish a non-contact co-culture model of endothelial cells (EC) and pericytes (PC) to furtherly investigate the cochlear stria vascularis microvascular pericytes impact on the permeability of endothelial cells. Methods: C57BL/6J mice were divided into two groups, three months old as young group, 12 months old as senile group. Cell experiment was divided into four groups, EC group, EC+PC co-culture group, D-gal+EC group and D-gal+EC+PC co-culture group. Auditory brainstem response (auditory brain response, ABR) was used to detect the auditory function of the two groups of mice. Evans blue staining was applied to detect the permeability of the cochlear blood labyrinth barrier of the two groups of mice. Transmission electron microscopy was used to observe the ultrastructure of blood labyrinth barrier endothelial cells, pericytes and tight junctions in the two groups of mice. Immunohistochemistry was used to detect the expression levels of tight junction proteins in the stria vascularis of the cochlea of the two groups of mice. Transwell chamber was used to detect the permeability of endothelial cells. Western blot and immunofluorescence technology were used to detect the expression level of tight junction protein on endothelial cells. SPSS 20.0 software was used to analyze the data. Results: Compared with the young group, the ABR threshold of the aging group was significantly increased, the latency of wave I was prolonged (t=10.25, P<0.01;t=5.61, P<0.05), the permeability of the cochlear blood labyrinth barrier was increased and the expression of tight junction protein on the vascular stria was decreased (P<0.05). The cochlear ultrastructure showed that the cochlear vascular stria microvascular lumen was deformed, the basement membrane thickened and the tight junction gap between endothelium enlarged. The positive rate of ECs and PCs in primary culture was more than 95%. The cells induced by 15 g/L D-gal were determined to be senescent cells. Compared with EC group, the expression of tight junction protein in endothelial cells of D-gal+EC group decreased（t=7.42，P<0.01；t=13.19，P<0.05）and the permeability increased (t=11.17, P<0.01). In the co-culture group, the expression of tight junction protein between endothelial cells in EC+PC co-culture group and D-gal+EC+PC co-culture group increased and the permeability decreased. Conclusions: In aging mice, the permeability of cochlear blood labyrinth barrier will increase and the level of tight junction protein will decrease; in aging state, cochlear vascular stria microvascular pericytes may affect endothelial cell permeability by regulating the expression of tight junction protein.

Vascular stents in the management of portal venous complications in living donor liver transplantation.

To evaluate the efficacy of stent placement in the treatment of portal vein (PV) stenosis or occlusion in living donor liver transplant (LDLT) recipients, 468 LDLT records were reviewed. Sixteen (10 PV occlusions and 6 stenoses) recipients (age range, 8 months-59 years) were referred for possible interventional angioplasty (dilatation and/or stent) procedures. Stent placement was attempted in all. The approaches used were percutaneous transhepatic (n = 10), percutaneous transsplenic (n = 4), and intraoperative (n = 2). Technical success was achieved in 11 of 16 patients (68.8%). The sizes of the stents used varied from 7 mm to 10 mm in diameter. In the five unsuccessful patients, long-term complete occlusion of the PV with cavernous transformation precluded catherterization. The mean follow-up was 12 months (range, 3-24). The PV stent patency rate was 90.9% (10/11). Rethrombosis and occlusion of the stent and PV occurred in a single recipient who had a cryoperserved vascular graft to reconstruct the PV during the LDLT operation. PV occlusion of >1 year with cavernous transformation seemed to be a factor causing technical failure. In conclusion, early treatment of PV stenosis and occlusion by stenting is an effective treatment in LDLT. Percutaneous transhepatic and transsplenic, and intraoperative techniques are effective approaches depending on the situation.

Liver graft regeneration in right lobe adult living donor liver transplantation.

Optimal portal flow is one of the essentials in adequate liver function, graft regeneration and outcome of the graft after right lobe adult living donor liver transplantation (ALDLT). The relations among factors that cause sufficient liver graft regeneration are still unclear. The aim of this study is to evaluate the potential predisposing factors that encourage liver graft regeneration after ALDLT. The study population consisted of right lobe ALDLT recipients from Chang Gung Memorial Hospital-Kaohsiung Medical Center, Taiwan. The records, preoperative images, postoperative Doppler ultrasound evaluation and computed tomography studies performed 6 months after transplant were reviewed. The volume of the graft 6 months after transplant divided by the standard liver volume was calculated as the regeneration ratio. The predisposing risk factors were compiled from statistical analyses and included age, recipient body weight, native liver disease, spleen size before transplant, patency of the hepatic venous graft, graft weight-to-recipient weight ratio (GRWR), posttransplant portal flow, vascular and biliary complications and rejection. One hundred forty-five recipients were enrolled in this study. The liver graft regeneration ratio was 91.2 +/- 12.6% (range, 58-151). The size of the spleen (p = 0.00015), total portal flow and GRWR (p = 0.005) were linearly correlated with the regeneration rate. Patency of the hepatic venous tributary reconstructed was positively correlated to graft regeneration and was statistically significant (p = 0.017). Splenic artery ligation was advantageous to promote liver regeneration in specific cases but splenectomy did not show any positive advantage. Spleen size is a major factor contributing to portal flow and may directly trigger regeneration after transplant. Control of sufficient portal flow and adequate hepatic outflow are important factors in graft regeneration.

LncRNA ANRIL impacts the progress of osteoarthritis via regulating proliferation and apoptosis of osteoarthritis synoviocytes.

OBJECTIVE: Long noncoding RNAs (lncRNAs) have been indicated to play an important role in many different diseases. Osteoarthritis (OA) is a disease which causes a change of morphology and function in articular cartilage and synovium, leading to cartilage degradation. Synovitis is a common pathological feature of OA, owing to the proliferation of synoviocytes. In this research, we want to verify the role of lncRNA ANRIL in osteoarthritis. PATIENTS AND METHODS: qRT-PCR was used to detect the expression of lncRNA ANRIL in normal synoviocytes and osteoarthritis synoviocytes. The cell proliferation in normal synoviocytes and osteoarthritis synoviocytes after transfection with lncRNA-NC or lncRNA-ANRIL were tested. The apoptosis rate and cell cycle in normal synoviocytes and osteoarthritis synoviocytes were detected by the Flow Cytometry analysis. Western blot was used to analyze the possible mechanism that ANRIL regulated the cells' proliferation in osteoarthritis. RESULTS: We indicated that the expression of ANRIL was significantly improved in OAS compared to NS. The expression of ANRIL was decreased and the cell proliferation was reduced in OAS after transfected with siRNA. And the cell cycle was suspended in G0/G1 phase and the cell apoptosis was improved in OAS after transfected with siRNA. Moreover, ANRIL could regulate the proliferation and apoptosis of OAS via miR-122-5p/DUSP4 axis. CONCLUSIONS: We suggest that lncRNA ANRIL was closely related to osteoarthritis. ANRIL may be involved in the development and progression of osteoarthritis and become a potential target for diagnosis and treatment in OA.

Knockdown of MiR-140-5 promotes osteogenesis of adipose-derived mesenchymal stem cells by targeting TLR4 and BMP2 and promoting fracture healing in the atrophic nonunion rat model.

OBJECTIVE: This study aims to assess the effect and mechanism of genetically modified adipose-derived mesenchymal stem cells (ASCs) with recombinant lentiviruses mediated knockdown of miR-140-5p in ASCs' osteogenesis in vitro and atrophic nonunion rat model. MATERIALS AND METHODS: This study included 36 male adult Sprague-Dawley (SD) rats weighing 400 g to 450 g from the experimental animal facility of our university. Approval was obtained from the University Animal Care Committee before the study. Rats' ASCs were prepared and genetically modified with lentivirus (Lv)-empty (NC) or Lv-miR-140-5p-TuD (inhibitors). After that, the expressions of RUNX2 and osteocalcin (OCN) were detected in the ASCs. To confirm the mechanisms of miR-140-5p in ASCs, we predicted the target genes by bioinformatics analysis and then the target genes were verified by luciferase reporting assay. The artificial atrophic nonunion was created in the rat's femoral bone. Animals were randomly divided into three groups according to the material implanted into bone defects space: AT scaffolds (AT group, n=12), AT scaffold with Lv-NC modified (AT+ASCs+Lv-NC group, n=12), AT scaffold with the Lv-miR-140-5p-TuD modified ASCs (AT+ASCs+Lv-miR-140-5p-TuD group, n=12). After four weeks, the rats were euthanized for the following radiographic examination, histologic study and biomechanical testing. RESULTS: MiR-140-5p was down-regulated during osteogenic differentiation of ASCs, and inhibition of MiR-140-5p promoted osteogenesis of ASCs in vitro. Inhibition of MiR-140-5p promoted osteogenesis of ASCs and enhanced fracture in the atrophic nonunion rat model: AT+ASCs+Lv-NC group, AT+ASCs+Lv-miR-140-5p-TuD group resulted in a better bone formation and higher BMD and BMC than AT group, while excellent bone formation and the highest BMD and BMC were observed in AT+ASCs+Lv-miR-140-5p-TuD group. Both AT+ASCs+Lv-NC group and AT+ASCs+Lv-miR-140-5p-TuD group presented more mature characteristics in the micro-architecture than AT group, whereas AT+ASCs+Lv-miR-140-5p-TuD group presented the highest BV/TV, Tb.Th and Tb.N as well as the lowest Tb.Sp. The peak load of the operated femur increased by 94.43% AT+ASCs+Lv-miR-140-5p-TuD group, 50.68% in AT+ASCs+Lv-NC group compared to the control AT group, respectively. The result of luciferase reporting assay showed that miR-140-5p could directly target TLR4 and BMP2. CONCLUSIONS: This study demonstrates that lentiviruses-mediated knockdown of miR-140-5p can significantly promote osteogenesis of ACSs by directly regulating its' target genes, TLR4 and BMP2, and that combined adipose scaffold with genetically modified ASCs can significantly enhance fracture-healing and bone formation in the atrophic nonunion rat model.

Preoperative imaging evaluation of potential living liver donors: reasons for exclusion from donation in adult living donor liver transplantation.

Accurate pretransplant evaluation of a potential donor in living donor liver transplantation (LDLT) is essential in preventing postoperative liver failure and optimizing safety. The aim of this study was to investigate the reasons for exclusion from donation of potential donors in adult LDLT. From September 2003 to June 2006, 266 potential donors were evaluated for 215 recipients: 220 potential donors for 176 adult recipients; 46 for 39 pediatric recipients. Imaging modalities including Doppler ultrasound, computerized tomography (CT), and magnetic resonance (MR) angiography provided vascular evaluation and MR cholangiopancreatography to evaluate biliary anatomy. Calculation of liver volume and assessment of steatosis were performed by enhanced and nonenhanced CT, respectively. In the adult group, only 83 (37.7%) potential donors were considered suitable for LDLT. Of the 137 unsuitable potential donors, 36 (26.2%) candidates were canceled because of recipient issues that included death of 15 recipients (10.9%), main portal vein thrombosis (8%), recipient condition beyond surgery (5%), and no indication for liver transplantation due to disease improvement (2%). The remaining 101 (73.8%) candidates who were excluded included steatosis (27.7%), an inadequate remnant volume (57.4%), small-for-size graft (8.9%), HLA-homozygous donor leading to one-way donor-recipient HLA match (3%), psychosocial problems (4%), as well as variations of hepatic artery (4%), portal vein (1%), and biliary system anatomy (5%). Anatomic considerations were not the main reason for exclusion of potential donors. An inadequate remnant liver volume (< 30%) is the crucial point for the adult LDLT decision.

Preoperative vascular evaluation in living donor liver transplantation for biliary atresia.

BACKGROUND: Liver transplantation is an important treatment option in the management of end-stage liver disease. Preoperative vascular evaluation plays an important role for a safe and successful operation, especially in pediatric patients undergoing living donor liver transplantation (LDLT). PURPOSE: The purpose of this study is to assess the usefulness and accuracy of Doppler ultrasound (US), computed tomographic angiography (CTA), and magnetic resonance angiography (MRA) in evaluating vascular anomalies in patients with biliary atresia (BA) undergoing LDLT. METHODS AND MATERIALS: Images of Doppler US, CTA, and MRA for preoperative vascular evaluation in 55 patients with BA undergoing LDLT were reviewed with the operative findings. RESULTS: All patients underwent preoperative US, CTA, and MRA. Pathologic portal vein (n = 18), interruption of the retrohepatic vena cava (n = 1), and aberrant right hepatic artery from the superior mesenteric artery (n = 2) were confirmed during the transplantation. The success rates of CTA and MRA in identifying vascular anomalies were 96% and 82%, respectively (P = .01). The sensitivity, specificity, and accuracy of Doppler US were 89%, 94%, and 92%, respectively. For CTA, it was 94%, 97%, and 96%, respectively; for MRA (including technical failure), it was 75%, 97%, and 89%, respectively. CONCLUSION: Doppler US serves as an initial assessment for vascular evaluation and has the advantage in determining vascular flow quantities. CTA and MRA are used for precise surgical planning. However, MRA has lower success and accuracy rates when compared with CTA (P = .01). Doppler US with CTA can provide accurate preoperative vascular imaging in patients with BA undergoing LDLT.

Correlation between hepatic steatosis, hepatic volume, and spleen volume in live liver donors.

INTRODUCTION: The purpose of this study was to evaluate the changes in liver fatty content and the volumes of liver and spleen after body weight reduction in potential living liver donors. MATERIALS AND METHODS: Twenty-three potential living donors had fatty livers at pretransplantation sonography and computed tomography (CT). All were advised to undergo body weight reduction by exercise and diet control. A percutaneous core liver biopsy was performed in segment 5 of the liver in 22 donors to evaluate the hepatic fat content before and after body weight reduction. We compared the changes in the liver CT attenuation values and volume changes in the left and right lobes of the liver and the spleen before and after body weight reduction. RESULTS: The mean (SD) body weight, body mass index, and fatty content of the liver biopsy specimens were 73 (17) kg, 26.8 (4.4), and 16.9% (12.7%), respectively, before body weight reduction and 70 (15) kg, 25.3 (3.8), and 6.6% (3.7%), respectively, thereafter. These changes were significant. The CT attenuation values of the left and right lobes of the liver and spleen were 54 (11), 51 (11), and 52 (5) HU, respectively, before body weight reduction and 60 (8), 58 (6), and 53 (5) HU, respectively, thereafter. The mean CT attenuation value of the left lateral segment was greater than that of the right lobe both before and after body weight reduction. The volume of the left and right lobes and spleen changed from 497 (129) cm3 to 452 (99) cm3, 927 (237) cm3 to 846 (173) cm3, and 185 (65) cm3 to 186 (63) cm3, respectively, thereafter. The right and left lobe volume change ratios were 7.0% (10.6%) and 7.6% (11.1%), respectively, but showed no significant difference. Twenty of the 23 candidates were able to donate part of their liver. CONCLUSION: Body weight reduction by exercise and diet control in potential living liver donors is effective to reduce the fatty content of the liver. Reversed percentage of the fatty content and volume of the liver was observed in these donors. The volumes of the right and left lobes of liver decreased significantly after body weight reduction. The volume changes were proportional.

Significance of portosystemic shunt on graft survival in liver transplantation: a rat model.

AIMS: Distal splenorenal shunt effectively controls bleeding from esophageal and gastric varices but has a different effect on liver transplantation. This study sought to develop an animal model in rats to mimic the recipient with a portosystemic shunt and to investigate its hemodynamic consequences on liver transplantation. METHODS: We prepared 5 groups of allogeneic or syngeneic rat liver transplantation models with versus without portosystemic shunt, to investigate its effects on graft survival and portal flow. To explore the effects of excessive portal flow on graft survival in small-for-size liver transplantation, we transplanted partial liver grafts into syngeneic recipients. RESULTS: In allogeneic combinations, graft survival among the shunt group was shortened compared with their control counterparts. The graft survival of the large shunt group was significantly lower than that of a small shunt or without shunt group in a syngeneic liver transplantation model. Portal blood pressure of the large shunt group was significantly lower than that of the small shunt group. In contrast, excessive portal flow resulted in dysfunction of liver graft in small-for-size liver transplantation. CONCLUSIONS: These results suggested that reduction in portal flow by portosystemic shunt lead to an acceleration of acute rejection and subsequent liver graft dysfunction, but it may be applicable to regulate the excessive portal flow in small-for-size transplantations. This study showed a valuable model mimicking the recipient with a portosystemic shunt.

Diagnosis and interventional radiological treatment of vascular and biliary complications after liver transplantation in children with biliary atresia.

OBJECTIVE: Early diagnosis and appropriate management of vascular and biliary complications after living donor liver transplantation (LDLT) result in longer survival. We report our institutional experience regarding radiological management of these complications among patients with biliary atresia (BA) who underwent LDLT. METHODS: We analyzed the records of 116 children. All patients underwent Doppler ultrasound (US) at operation, daily for the first 2 postoperative weeks, and when necessary thereafter. After primary evaluation using US, the definite diagnosis of postoperative complication was confirmed using computed tomography, magnetic resonance imaging, and/or operation. RESULTS: There were 61 boys and 55 girls. The overall mean age was 2.69 years. The overall mean preoperative weight and height were 13.06 kg and 83.79 cm, respectively. There were 28 (24.13%) biliary and vascular complications. These were cases of biliary stricture (n = 5), bile leakage (n = 3), hepatic artery stenosis (n = 6), hepatic vein stenosis (n = 4), and portal vein thrombosis (n = 17). The diagnostic accuracy of US in detecting biliary complication, hepatic artery stenosis, hepatic venous stenosis, and portal vein thrombosis was 95.69%, 97.41%, 100%, and 100%, respectively. US in combination with multiple imaging modalities and clinical suspicion resulted in 100% diagnostic accuracy. Percutaneous transhepatic cholangiography, thrombolysis, balloon angioplasty, and stent placement were performed for the complications noted. There was an early mortality due to multiple-organ failure after failed radiological invention and subsequent surgical management. CONCLUSIONS: Doppler US is accurate in detecting postoperative complications after pediatric LDLT for BA. Radiological interventions for vascular and biliary complications are effective and safe alternatives to reconstructive surgery.

Effects of different operating room temperatures on the body temperature undergoing live liver donor hepatectomy.

OBJECTIVE: We sought to compare the effects of operation room temperature (ORT) at typical ambient environment (19-21 degrees C) and ORT at 24 degrees C on the core temperature of patients undergoing living donor hepatectomy. METHODS AND PATIENTS: Sixty-two patients undergoing living donor hepatectomy were divided into 2 groups. In group I (n = 31), surgery was performed at typical ambient ORT, and in group II (n = 31) in ORT at 24 degrees C. Anesthesia and measures to prevent heat loss, except ORT, were all the same. Nasopharyngeal temperature (NT) was recorded after anesthesia induction, then hourly until completion of the operation. Changes in NTs were analyzed as well as patient age, weight, anesthetic duration, blood loss, intravenous fluids, total urine output, and pre- and postoperative hemoglobin and hematocrit values. The Mann-Whitney U test was used for comparisons between groups. RESULTS: The patient's characteristics between groups were not statistically different. However, a significantly higher core temperature was noted in group II compared with group I. Increased ORT from 19 to 21 degrees C to 24 degrees C resulted in an increased core temperature of at least 0.5 degrees C during living donor hepatectomy.