Liver Transplantation from Brain-Dead Donors with Hepatitis B or C in South Korea: A 2014-2020 Korean Organ Transplantation Registry Data Analysis.

BACKGROUND According to the current guidelines for liver transplantation (LT) of brain-dead donors with hepatitis B or C virus (HBV or HCV) in Korea, grafts from hepatitis B surface antigen (HBsAg)(+) or HCV antibody (anti-HCV)(+) donors must be transplanted only to HBsAg(+) or anti-HCV(+) recipients, respectively. We aimed to determine the current status and outcomes of brain-dead donor LT with HBV or HCV in Korea. MATERIAL AND METHODS This retrospective observational study included all LTs from brain-dead donors in the Korean Organ Transplantation Registry between April 2014 and December 2020. According to donor hepatitis status, 24 HBV(+), 1 HCV(+), and 1010 HBV(-)/HCV(-) donors were included. RESULTS Baseline/final model for end-stage liver disease score (MELD) for HBV(+), HCV(+), and HBV(-)/HCV(-) were 22.4±9.3/27.8±7.8, 16/11, and 33.0±15.4/35.5±7.1, respectively. MELD score of HBV (+) were lower than those of HBV(-)/HCV(-) (P<0.01). Five-year graft and patient survival rates of HBV(+) and HBV(-)/HCV(-) recipients were 81.7%/85.6%, and 76.6%/76.7%, respectively (P=0.73 and P=0.038). One-year graft and patient survival rates of HCV (+) graft recipients were both 100%. CONCLUSIONS No differences in graft and patient survival rates between HBV(+) and HBV(-)/HCV(-) groups were observed. Although accumulating the results of transplants from HBV (+) or HCV(+) grafts to HBV(-) or HCV(-) recipients is not possible owing to domestic regulations, Korea should conditionally permit transplantations from HBV(+) or HCV(+) grafts to HBV(-) or HCV(-) recipients by considering the risks and benefits based on foreign studies. Thereafter, we can accumulate the data from Korea and analyze the outcomes.

Kidney Transplantation From Brain-Dead Donors With Hepatitis B or C in South Korea: A 2015 to 2020 Korean Organ Transplantation Registry Data Analysis.

BACKGROUND: According to the current Center for Korean Network for Organ Sharing guidelines for kidney transplantation from brain-dead donors with hepatitis B or C infection, organs from hepatitis B surface antigen-positive (HbsAg+) or anti-hepatitis C virus-positive (HCV+) donors can only be transplanted into HBsAg+ or anti-HCV+ recipients. We aimed to confirm the status and the outcomes of kidney transplantation from brain-dead donors with hepatitis B or C virus in Korea. METHODS: This retrospective study included all kidney transplantations from brain-dead donors in the Korean Organ Transplantation Registry database between January 2015 and June 2020, divided into 3 groups according to donor hepatitis status. Finally, kidney transplantations from 80 HBV+, 12 HCV+, and 2013 HBV-/HCV- donors were included. RESULTS: No statistically significant differences were observed in the recipient characteristics and the transplant outcomes except the waiting time (HBV+ to HBV-/HCV-, P < .001; HCV+ to HBV-/HCV-, P = .10; HBV+ to HCV+P = .95). Five-year graft survival rates of the HBV+, HCV+, and HBV-/HCV- recipients were 95%, 83%, and 85%, respectively (HBV+ to HCV+, P = .22; HCV+ to HBV-/HCV-, P = .81; HBV+ to HBV-/HCV-, P = .02). Five-year patient survival rates of the HBV+, HCV+, and HBV-/HCV- recipients were 95%, 100%, and 76%, respectively (HBV+ to HCV+, P = .61; HCV+ to HBV-/HCV-, P = .13; HBV+ to HBV-/HCV-, P < .001). CONCLUSION: HBV+/HCV+ brain-dead donor kidney transplantation outcomes were comparable to HBV-/HCV-. South Korea should consider conditionally permitting transplantation from HBV+ or HCV+ donors to HBV- or HCV- recipients to accumulate new data and conduct further studies.

Cerebral perfusion simulation using realistically generated synthetic trees for healthy and stroke patients.

BACKGROUND AND OBJECTIVE: Cerebral vascular diseases are among the most burdensome diseases faced by society. However, investigating the pathophysiology of diseases as well as developing future treatments still relies heavily on expensive in-vivo and in-vitro studies. The generation of realistic, patient-specific models of the cerebrovascular system capable of simulating hemodynamics and perfusion promises the ability to simulate diseased states, therefore accelerating development cycles using in silico studies and opening opportunities for the individual assessment of diseased states, treatment planning, and the prediction of outcomes. By providing a patient-specific, anatomically detailed and validated model of the human cerebral vascular system, we aim to provide the basis for future in silico investigations of the cerebral physiology and pathology. METHODS: In this retrospective study, a processing pipeline for patient-specific quantification of cerebral perfusion was developed and applied to healthy individuals and a stroke patient. Major arteries are segmented from 3T MR angiography data. A synthetic tree generation algorithm titled tissue-growth based optimization (GBO)1 is used to extend vascular trees beyond the imaging resolution. To investigate the anatomical accuracy of the generated trees, morphological parameters are compared against those of 7 T MRI, 9.4 T MRI, and dissection data. Using the generated vessel model, hemodynamics and perfusion are simulated by solving one-dimensional blood flow equations combined with Darcy flow equations. RESULTS: Morphological data of three healthy individuals (mean age 47 years ± 15.9 [SD], 2 female) was analyzed. Bifurcation and physiological characteristics of the synthetically generated vessels are comparable to those of dissection data. The inability of MRI based segmentation to resolve small branches and the small volume investigated cause a mismatch in the comparison to MRI data. Cerebral perfusion was estimated for healthy individuals and a stroke patient. The simulated perfusion is compared against Arterial-Spin-Labeling MRI perfusion data. Good qualitative agreement is found between simulated and measured cerebral blood flow (CBF)2. Ischemic regions are predicted well, however ischemia severity is overestimated. CONCLUSIONS: GBO successfully generates detailed cerebral vascular models with realistic morphological parameters. Simulations based on the resulting networks predict perfusion territories and ischemic regions successfully.

Successfully Managing Severe Anemia in a Trauma Patient Who Refused Blood Transfusion: A Case Report.

BACKGROUND Surgical management in patients who undergo traumatic blood loss but who refuse blood transfusion can be challenging, but physicians and surgeons must comply with the wishes and beliefs of their patients. This report describes the management of severe anemia, with hemoglobin level of 2.5 g/dL, in a 71-year-old male Korean trauma patient who declined blood transfusion. CASE REPORT A 71-year-old man was admitted to hospital with severe blood loss following trauma. He declined blood transfusion due to his religious belief as a Jehovah's Witness. On day 4, the patient's hemoglobin level dropped from 7.7 to 3.9 g/dL. Despite the need for blood transfusion, the patient refused. Hence, therapeutic strategies, including crystalloid fluid resuscitation, bleeding control, vasopressor support, erythropoietin administration, supplementation with iron, folic acid, and vitamin B12, coagulopathy correction, oxygen consumption reduction, and mechanical ventilation were implemented. Following 16 days of supportive management, the hemoglobin reached 7.4 g/dL. However, it suddenly decreased on day 41 (2.5 g/dL) due to episodes of melena secondary to an actively bleeding gastric ulcer, which was successfully managed with endoscopic hemostasis. Despite increased vasopressor dosage and addition of vasopressin and hydrocortisone, the patient became unresponsive with persistent hypotension. Methylene blue was used as the final therapeutic agent. The patient responded well and subsequently recovered without blood transfusion. CONCLUSIONS This report has presented the clinical challenges of managing the case of a patient who requires but declines blood transfusion and has highlighted the approach to clinical care while respecting the wishes of the patient.

Hematic auto-management and extraction for arterial line (HAMEL), a blood-preserving arterial line system: an animal study.

Invasive arterial line insertion is a common procedure in the intensive care unit ICU; however, it can cause unnecessary blood loss while procuring blood for laboratory tests. To reduce blood loss resulting from flushing out the arterial line dead space, we developed a new blood-preserving arterial line system: Hematic Auto-Management & Extraction for arterial Line (HAMEL, MUNE Corp.). Five male three-way crossbred pigs were used to evaluate the necessary amount of blood to be withdrawn before sampling to produce accurate results. We then tested whether the traditional sampling method and the HAMEL system showed non-inferior results for blood tests. Blood gas (CG4 + cartridge) and chemistry (CHEM8 + cartridge) analyses were used for comparison. The total unnecessary blood loss in the traditional sampling group was 5 mL/sample. For HAMEL, withdrawing 3 mL of blood before sampling yielded hematocrit and hemoglobin results within 90% confidence interval of traditional sampling group. Most intra-class correlation coefficients between the traditional sampling and HAMEL system groups were > 0.90. When compared to the traditional sampling method, withdrawal of 3 mL with HAMEL was sufficient before blood sampling. Utilization of the HAMEL system was not inferior to the traditional hand-sampling method. In addition, no unnecessary blood loss occurred in the HAMEL system.

Mangiferin Ameliorates Obesity-Associated Inflammation and Autophagy in High-Fat-Diet-Fed Mice: In Silico and In Vivo Approaches.

Obesity-induced insulin resistance is the fundamental cause of metabolic syndrome. Accordingly, we evaluated the effect of mangiferin (MGF) on obesity and glucose metabolism focusing on inflammatory response and autophagy. First, an in silico study was conducted to analyze the mechanism of MGF in insulin resistance. Second, an in vivo experiment was conducted by administering MGF to C57BL/6 mice with high-fat-diet (HFD)-induced metabolic disorders. The in silico analysis revealed that MGF showed a high binding affinity with macrophage-related inflammatory cytokines and autophagy proteins. In the in vivo study, mice were divided into three groups: normal chow, HFD, and HFD + MGF 150 mg/kg. MGF administration to obese mice significantly improved the body weight, insulin-sensitive organs weights, glucose and lipid metabolism, fat accumulation in the liver, and adipocyte size compared to HFD alone. MGF significantly reduced the macrophages in adipose tissue and Kupffer cells, inhibited the gene expression ratio of tumor necrosis factor-α and F4/80 in adipose tissue, reduced the necrosis factor kappa B gene, and elevated autophagy-related gene 7 and fibroblast growth factor 21 gene expressions in the liver. Thus, MGF exerted a therapeutic effect on metabolic diseases by improving glucose and lipid metabolism through inhibition of the macrophage-mediated inflammatory responses and activation of autophagy.

Effects of Electric Cortical Stimulation (ECS) and Transcranial Direct Current Stimulation (tDCS) on Rats With a Traumatic Brain Injury.

OBJECTIVE: To evaluate the effects of electric cortical stimulation (ECS) and transcranial direct current stimulation (tDCS) on motor and cognitive function recovery and brain plasticity in focal traumatic brain injury (TBI) of rats model. METHODS: Forty rats were pre-trained to perform a single pellet reaching task (SPRT), rotarod test (RRT), and Y-maze test for 14 days, then a focal TBI was induced by a weight drop model on the motor cortex. All rats were randomly assigned to one of the three groups: anodal ECS (50 Hz and 194 µs) (ECS group), tDCS (0.1 mA, 50 Hz and 200 µs) (tDCS group), and no stimulation as a control group. Four-week stimulation, including rehabilitation, was started 3 days after the operation. SPRT, RRT, and Y-maze were measured from day 1 to day 28 after the TBI was induced. Histopathological and immunohistochemistry staining evaluations were performed at 4 weeks. RESULTS: SPRT was improved from day 7 to day 26 in ECS, and from day 8 to day 26 in tDCS compared to the control group (p<0.05). SPRT of ECS group was significantly improved on days 3, 8, 9, and 17 compared to the tDCS group. Y-maze was improved from day 8 to day 16 in ECS, and on days 6, 12, and 16 in the tDCS group compared to the control group (p<0.05). Y-maze of the ECS group was significantly improved on day 9 to day 15 compared to the tDCS group. The c-Fos protein expression was better in the ECS group and the tDCS group compared to the control group. CONCLUSION: Electric stimulation in rats modified with a focal TBI is effective for motor recovery and brain plasticity. ECS induced faster behavioral and cognitive improvements compared to tDCS during the recovery period of rats with a focal TBI.

Development of patient-controlled respiratory gating system based on visual guidance for magnetic-resonance image-guided radiation therapy.

PURPOSE: The aim of this study is to develop a visual guidance patient-controlled (VG-PC) respiratory gating system for respiratory-gated magnetic-resonance image-guided radiation therapy (MR-IGRT) and to evaluate the performance of the developed system. METHODS: The near-real-time cine planar MR image of a patient acquired during treatment was transmitted to a beam projector in the treatment room through an optical fiber cable. The beam projector projected the cine MR images inside the bore of the ViewRay system in order to be visible to a patient during treatment. With this visual information, patients voluntarily controlled their respiration to put the target volume into the gating boundary (gating window). The effect of the presence of the beam projector in the treatment room on the image quality of the MRI was investigated by evaluating the signal-to-noise ratio (SNR), uniformity, low-contrast detectability, high-contrast spatial resolution, and spatial integrity with the VG-PC gating system. To evaluate the performance of the developed system, we applied the VG-PC gating system to a total of seven patients; six patients received stereotactic ablative radiotherapy (SABR) and one patient received conventional fractionated radiation therapy. RESULTS: The projected cine MR images were visible even when the room light was on. No image data loss or additional time delay during delivery of image data were observed. Every indicator representing MRI quality, including SNR, uniformity, low-contrast detectability, high-contrast spatial resolution, and spatial integrity exhibited values higher than the tolerance levels of the manufacturer with the VG-PC gating system; therefore, the presence of the VG-PC gating system in the treatment room did not degrade the MR image quality. The average beam-off times due to respiratory gating with and without the VG-PC gating system were 830.3 ± 278.2 s and 1264.2 ± 302.1 s respectively (P = 0.005). Consequently, the total treatment times excluding the time for patient setup with and without the VG-PC gating system were 1453.3 ± 297.3 s and 1887.2 ± 469.6 s, respectively, on average (P = 0.005). The average number of beam-off events during whole treatment session was reduced from 457 ± 154 times to 195 ± 90 times by using the VG-PC gating system (P < 0.001). CONCLUSIONS: The developed system could improve treatment efficiency when performing respiratory-gated MR-IGRT. The VG-PC gating system could be applied to any kind of bore-type radiotherapy machine.

Estimation of stature from femur length measured using computed tomography after the analysis of three-dimensional characteristics of femur bone in Korean cadavers.

Estimation of stature is a basic and important forensic procedure in identifying decomposed or skeletonized bodies. Due to advances in radiologic equipment, forensic science frequently uses computed tomography (CT) and software to apply these findings to investigations. Technical developments have increased the accuracy of the measurement of various bones. However, there are still some inaccuracies, such as defining correct landmarks in three-dimensional (3D) images. Femur length is frequently used for calculation of stature, but because it is a 3D structure, the digital image may not always correlate with the femur length measured with an osteometric board. However, more studies are now showing that the maximum femur length calculated in 3D imagery is comparable to the maximum femur length calculated using an osteometric board. This study used digitalized data of the femur obtained from the CT image through the specialized software. The digitalized femur images were put on the virtual osteometric board, which helped us to understand the anatomic characteristics of the femur and to confirm that the maximum femur lengths calculated in 3D images are similar to the results obtained using an osteometric board. These data were used to obtain a stature estimation formula for the Korean population.

Differential regulation of the histone chaperone HIRA during muscle cell differentiation by a phosphorylation switch.

Replication-independent incorporation of variant histone H3.3 has a profound impact on chromatin function and numerous cellular processes, including the differentiation of muscle cells. The histone chaperone HIRA and H3.3 have essential roles in MyoD regulation during myoblast differentiation. However, the precise mechanism that determines the onset of H3.3 deposition in response to differentiation signals is unclear. Here we show that HIRA is phosphorylated by Akt kinase, an important signaling modulator in muscle cells. By generating a phosphospecific antibody, we found that a significant amount of HIRA was phosphorylated in myoblasts. The phosphorylation level of HIRA and the occupancy of phosphorylated protein on muscle genes gradually decreased during cellular differentiation. Remarkably, the forced expression of the phosphomimic form of HIRA resulted in reduced H3.3 deposition and suppressed the activation of muscle genes in myotubes. Our data show that HIRA phosphorylation limits the expression of myogenic genes, while the dephosphorylation of HIRA is required for proficient H3.3 deposition and gene activation, demonstrating that the phosphorylation switch is exploited to modulate HIRA/H3.3-mediated muscle gene regulation during myogenesis.

Efficient high-power frequency doubling of distributed Bragg reflector tapered laser radiation in a periodically poled MgO-doped lithium niobate planar waveguide.

We report on efficient single-pass, high-power second-harmonic generation in a periodically poled MgO-doped LiNbO3 planar waveguide using a distributed Bragg reflector tapered diode laser as a pump source. A coupling efficiency into the planar waveguide of 73% was realized, and 1.07 W of visible laser light at 532 nm was generated. Corresponding optical and electro-optical conversion efficiencies of 26% and 8.4%, respectively, were achieved. Good agreement between the experimental data and the theoretical predictions was observed.

Birefringent waveguide sensor using a polarizer rotating technique.

A birefringence measurement system is introduced to get high phase resolution for detection of low contents of biochemicals. By using a fixed quarter-wave plate and a rotating polarizer, the phase difference between two orthogonal polarizations is transformed into phase delay of output sinusoidal signal. Analyzing the output phase, birefringence change could be detected with a phase noise of 0.14 degrees. As well as the birefringence measurement system, an optical evanescent waveguide sensor was developed. A rib-type silica waveguide overlaid with TiO2 film was fabricated, and a developed birefringence measurement technique was employed in evaluating a refractive index change on waveguide surface. For the fabricated waveguide with a 40-nm-thick TiO2 film, experiment results showed that the minimum detectable index change was 5.9x10(-7).

Integrated optical modulator for signal up-conversion over radio-on-fiber link.

An integrated optical modulator, which consists of a dual-sideband suppressed carrier (DSB-SC) modulator cascaded with a single-sideband (SSB) modulator, is proposed for signal up-conversion over Radio-on-Fiber. Utilizing a single-drive domain inverted structure in both modulators, balanced modulations were obtained without complicated radio frequency (RF) driving circuits and delicate RF phase adjustments. Intermediate frequency (IF) band signal was up-conversed to 60GHz band by using the fabricated device and was transmitted over optical fiber. Experiment results show that the proposed device enables millimeter wave generation and signal transmission without any power penalty caused by chromatic dispersion.

Leaky modes of curved long-range surface plasmon-polariton waveguide.

A three-dimensional method for obtaining the bending losses and field distributions of bent surface plamon-polariton waveguides is presented. The method is based on a so called 'method of line', which discretises potential in the direction of the metal-widths, and leads to Airy-equations in the radial direction. From the results obtained. It is confirmed that thiner metal waveguide enable longer-ranging propagation of surface plasmon-polariton mode, but the weakened confinement requires larger bending radii on order to keep radiation loss.

Foliar spray of validamycin a or validoxylamine a controls tomato fusarium wilt.

ABSTRACT Tomato wilt, caused by the soilborne fungus Fusarium oxysporum f. sp. lycopersici, is effectively controlled by a foliar spray of validamycin A (VMA) or validoxylamine A (VAA) (>/=10 mug/ml); however, neither VMA nor VAA is antifungal in vitro. In pot tests, the effect of a foliar application of VMA or VAA at 100 mug/ml lasted for 64 days. Plants sprayed with VMA or VAA accumulated salicylic acid and had elevated expression of the systemic acquired resistance (SAR) marker genes P4 (PR-1), Tag (PR-2), and NP24 (PR-5). Foliar spray of VMA also controlled late blight and powdery mildew of tomato. The disease control by VMA and VAA lasted up to 64 days after treatment, was broad spectrum, and induced the expression of PR genes, all essential indicators of SAR, suggesting that VMA and VAA are plant activators. The foliar application of plant activators is a novel control method for soilborne diseases and may provide an economically feasible alternative to soil fumigants such as methyl bromide.

Wavelength selective single and dual-channel dropping in a periodically poled Ti:LiNbO(3) waveguide.

All-optical wavelength selective single and dual channel dropping by sum frequency generation has been demonstrated in a periodically poled Ti:LiNbO(3) waveguide, which has two second harmonic phase-matching peaks. Less than -17 dB of channel dropping extinction ratio was observed with coupled pump power of 325 mW.

Effects of parasitic modes in high-speed LiNbO(3) optical modulators.

The characteristics of RF parasitic modes and the methods to suppress leakage phenomena in LiNbO(3) optical modulators were studied. The high frequency RF power transmission characteristics were simulated and experimented in the respects of LiNbO(3) wafer thickness, the kind of material contacting the back surface of the modulator chip, the gap and width of the CPW (co-planar waveguide) electrodes. An appropriate RF electrode geometry, to minimize coupling efficiency between co-planar waveguide and substrate mode, is proposed. Experimental results prove that the approaches made in this work are effective for broadening of modulation bandwidth.