Nuclear magnetic resonance measurements in dynamically controlled field pulse.

We present the architecture of the versatile nuclear magnetic resonance (NMR) spectrometer with software-defined radio technology and its application to the dynamically controlled pulsed magnetic fields. The pulse-field technology is the only solution to access magnetic fields greater than 50 T, but the NMR experiment in the pulsed magnetic field was difficult because of the continuously changing field strength. The dynamically controlled field pulse allows us to perform NMR experiment in a quasi-steady field condition by creating a constant magnetic field for a short time around the peak of the field pulse. We confirmed the reproducibility of the field pulses using the NMR spectroscopy as a high precision magnetometer. With the highly reproducible field strength, we succeeded in measuring the nuclear spin-lattice relaxation rate 1/T1, which had never been measured by the pulse-field NMR experiment without dynamic field control. We also implement the NMR spectrum measurement with both the frequency-sweep and field-sweep modes and discuss the appropriate choices of these modes depending on the magnetic properties of the sample to be measured. This development, with further improvement at a long-duration field pulse, will innovate the microscopic measurement in extremely high magnetic fields.

Transition of Spleen Volume Long After Pediatric Living Donor Liver Transplantation for Biliary Atresia.

PURPOSE: After undergoing the Kasai procedure for biliary atresia (BA), most patients develop severe splenomegaly that tends to be improved by liver transplantation. However, fluctuations in splenic volume long after transplantation remain to be elucidated. PATIENTS AND METHODS: Seventy-one consecutive patients who had undergone pediatric living donor liver transplantation (LDLT) for BA were followed up in our outpatient clinic for 5 years. They were classified into 3 groups according to their clinical outcomes: a good course group (GC, n = 41) who were maintained on only 1 or without an immunosuppressant, a liver dysfunction group (LD, n = 18) who were maintained on 2 or 3 types of immunosuppressants, and a vascular complication group (VC, n = 11). Splenic and hepatic volumes were calculated by computed tomography in 464 examinations and the values compared before and after the treatment, especially in the VC group. RESULTS: Splenic volume decreased exponentially in the GC group, with splenic volume to standard spleen volume ratio (SD) being 1.59 (0.33) 5 years after liver transplantation. Splenic volume to standard spleen volume ratios were greater in the VC and LD groups than in the GC group. Patients in the VC group with portal vein stenosis developed liver atrophy and splenomegaly, whereas those with hepatic vein stenosis developed hepatomegaly and splenomegaly. Interventional radiation therapy tended to improve the associated symptoms. CONCLUSIONS: Fluctuations in splenic volume long after pediatric LDLT for BA may reflect various clinical conditions. Evaluation of both splenic and hepatic volumes can facilitate understanding clinical conditions following pediatric LDLT.

Endotoxin Metabolism Reflects Hepatic Functional Reserve in End-Stage Liver Disease.

BACKGROUND: The hepatic clearance of endotoxin (Et) may reflect hepatic functional reserve and ischemic injury to hepatocytes. Therefore, we examined the relationships between Et activity (EA) and the metrics Pediatric End-Stage Liver Disease (PELD)/Model of End-Stage Liver Disease (MELD) score and alanine transaminase (ALT) levels in the postoperative period. METHODS: We performed 8 living-donor liver transplantations (LDLTs) for biliary atresia at our center from April 2012 to December 2012. EA was measured by means of an Et activity assay (EAA) in samples collected from a vein 1 day before LDLT, from the portal vein during the intraoperative anhepatic phase, from an artery 1 hour after reperfusion, from an artery on postoperative day (POD) 1, and from an artery or vein at PODs 7 and 14. RESULTS: EAs generally remained at low levels. EA at the reperfusion period was significantly lowest. The correlation coefficient for the preoperative MELD/PELD score and the EAA was 0.837, and the corresponding P value was .009; thus, there was a significant relationship between the preoperative MELD/PELD score and the EAA. The correlation coefficients for ALT at POD 1 and EA during the anhepatic phase, at 1 hour after reperfusion, and at POD 1 were 0.64, 0.43, and 0.38, respectively, and the P values for these correlations were .08, .67, and .34. Thus, we observed that ALT and EA generally tended to be somewhat directly correlated, but no significant relationships between these 2 metrics were observed. CONCLUSIONS: Endotoxin metabolism reflects the hepatic functional reserve capacity of end-stage liver disease.

Antibody Drug Treatment for Steroid-Resistant Rejection After Pediatric Living Donor Liver Transplantation: A Single-Center Experience.

BACKGROUND: Antibody drugs have been used to treat steroid-resistant rejection (SRR) after liver transplantation. Although anti-thymocyte globulin has been used for SRR after liver transplantation in place of muromonab-CD3 since 2011 in Japan, the effectiveness of anti-thymocyte globulin after pediatric living-donor liver transplantation (LDLT) has not yet been reported. The aim of this study was to evaluate the effectiveness of antibody drug treatment for SRR after pediatric LDLT in our single center. METHODS: Between May 2001 and December 2013, 220 pediatric LDLTs were performed. Initial immunosuppression after LDLT included tacrolimus and methylprednisolone therapy. Acute rejection was diagnosed by use of a liver biopsy and the administration of steroid pulse treatment, and SRR was defined as acute rejection refractory to the steroid pulse treatment. RESULTS: Acute rejection and SRR occurred in 74 (33.6%) and 16 patients (7.3%), respectively. The graft survival rates of non-SRR and SRR were 92.4% and 87.5%, respectively (P = .464). The median concentration of alanine aminotransferase before and after the administration of antibody drug was 193.5 mU/mL (range, 8-508) and 78 mU/mL (range, 9-655), respectively (P = .012). The median rejection activity index before and after the administration of antibody drugs was 5 (range, 2-9) and 1 (range, 0-9), respectively (P = .004). After antibody drug treatment, 12 patients had cytomegalovirus infections, 2 patients had Epstein-Barr virus infections, 3 patients had respiratory infections, and 1 patient had encephalitis. The cause of death in 1 patient with SRR was recurrence of infant fulminant hepatic failure. CONCLUSIONS: Antibody drug treatment for SRR after pediatric LDLT is safe and effective.

Relationship Between Graft Liver Function and the Change of Graft Liver and Spleen Volumes After Technical Variant Liver Transplantation.

BACKGROUND: Although there have been a few reports describing the changes of graft liver and spleen volumes after liver transplantation (LT), little is known about the relationship between graft liver function and the changes of these volumes after technical variant liver transplantation (TVLT). We therefore performed a retrospective study to investigate the relationship between graft liver function and these volumes after TVLT. METHODS: We retrospectively investigated the cases of 140 TVLT procedures that were performed in our department between July 1987 and October 2012 and in which follow-up was conducted at our department. We calculated the graft liver volume to standard liver volume (GV/SLV) ratio, the spleen volume to standard spleen volume (SV/SSV) ratio, and the spleen volume to graft liver volume (S/L) ratio by CT volumetry. We clarified the relationship between graft liver function (according to the pathological findings) and the graft liver and spleen volumes at 2, 5, and 10 years after TVLT. RESULTS: In the normal liver function group, the GV/SLV, SV/SSV, and S/L ratios decreased until 6 months after TVLT and then converged at 10 years after TVLT to 0.95, 1.27, and 0.27, respectively. In the graft liver failure group, the GV/SLV, SV/SSV, and S/L ratios at 10 years after TVLT were 0.67, 5.01, and 1.55, respectively. A significant correlation was observed between the GV/SLV ratio and the presence of mild liver fibrosis at 2 and 5 years after TVLT (P = .03 and P = .04, respectively). CONCLUSIONS: Post-transplant CT-volumetry is a noninvasive and effective means of evaluating graft liver status.

Complementary Indicators for Diagnosis of Hepatic Vein Stenosis After Pediatric Living-donor Liver Transplantation.

INTRODUCTION: Although hepatic vein stenosis after liver transplantation is a rare complication, the complication rate of 1% to 6% is higher in pediatric living-donor liver transplantation than that in other liver transplantation cases. Diagnosis is very important because this complication can cause hepatic congestion that develops to liver cirrhosis, graft loss, and patient loss. However, this is unlikely in cases where there are no ascites or hypoalbuminemia. OBJECTIVES: Eleven of 167 patients who had undergone pediatric living-donor liver transplantation were identified in the outpatient clinic at Jichi Medical University as having suffered from hepatic vein stenosis, and were enrolled in the study. METHODS: We conducted a retrospective study in which we reviewed historical patient records to investigate the parameters for diagnosis and examine treatment methods and outcomes. RESULTS: The 11 patients were treated with 16 episodes of balloon dilatation. Three among these received retransplantation and another 2 cases required the placement of a metallic stent at the stenosis. Histological examination revealed severe fibrosis in four of nine patients who had a liver biopsy, with mild fibrosis revealed in the other five grafts. Furthermore, hepatomegaly and splenomegaly diagnosed by computed tomography, elevated levels of hyarulonic acid, and/or a decrease in calcineurin inhibitor clearance were found to be pathognomonic at diagnosis, and tended to improve after treatment. CONCLUSIONS: Diagnosis of hepatic vein stenosis after liver transplantation can be difficult, so careful observation is crucial to avoid the risk of acute liver dysfunction. Comprehensive assessment using volumetry of the liver and spleen and monitoring of hyarulonic acid levels and/or calcineurin inhibitor clearance, in addition to some form of imaging examination, is important for diagnosis and evaluation of the effectiveness of therapy.

Living-Donor Liver Transplantation Using Segment 2 Monosegment Graft: A Single-Center Experience.

BACKGROUND: In small infants, left lateral segment grafts are sometimes too large to overcome the problems of large-for-size grafts in the abdominal compartment. To address this problem, we have developed a safe living donor graftectomy for neonates, a so-called "S2 monosegment graft" to minimize graft thickness. We reviewed our single-center experience to evaluate the feasibility of this technique for reducing graft size. METHODS: Eleven living-donor liver transplants using S2 monosegment grafts were performed between October 2008 and September 2014 at our institution. Medical records of both donors and recipients were reviewed and data collected retrospectively. RESULTS: The mean age of recipients at the time of transplantation was 125.3 days, including 3 neonates. The average S2 monosegment graft weight was 127.4 g, and the graft-to-recipient body weight ratio was successfully reduced to 3.5%. The graft livers were reduced to 4.1 cm in thickness. Two recipients with grafts larger than 5 cm could not undergo primary abdominal closure. Portal vein stenosis and biliary stenosis was observed in 1 recipient, and hepatic artery complications were seen in 2 recipients; the clinical course for all donors were uneventful. Liver regeneration was seen in every patient. The graft and patient 1-year survival rate was 100%. CONCLUSIONS: Living-donor liver transplantation using S2 monosegment grafts offers a safe and useful option for treating smaller infants. Here, we introduce our method of S2 monosegment graft emphasizing the donor harvest and graft thickness.

A novel split liver protocol using the subnormothermic oxygenated circuit system in a porcine model of a marginal donor procedure.

BACKGROUND: A merit of subnormothermic perfusion has been reported to preserve grafts from ischemic injury in animal models. The split liver technique is commonly performed to solve the shortage of liver grafts. However, there has been no study showing the effect of a split liver graft on subnormothermic perfusion. We herein investigated the split liver protocol using a subnormothermic oxygenated circuit system (SOCS). METHODS: Auxiliary liver transplantation was performed in a porcine marginal donor model by using a SOCS. In the SOCS group, the portal vein and hepatic artery of the graft were cannulated, and the graft was perfused by SOCS. In the cold storage (CS) group, the graft was placed in cold preservation solution. In the preservation phase, the graft was split. RESULTS: There were no significant differences in the biochemical markers between the SOCS and CS groups. In terms of the histology, the sinusoidal spaces were widened in the CS group 12 hours after implantation. CONCLUSION: We have demonstrated a possibility to use SOCS with the split liver protocol by using a porcine model. This split liver protocol using SOCS will extend the split liver criteria and rescue more patients from hepatic failure, including pediatric patients.

Risk factors of cytomegalovirus infection after pediatric liver transplantation.

PURPOSE: Cytomegalovirus (CMV) infection is known to be the most frequently viral infection among patients after liver transplantation. This is especially true in pediatric living-donor liver transplantation because the recipients have often not been infected with CMV and postoperative primary infection with CMV frequently occurs. PATIENTS AND METHODS: Of 93 patients who underwent pediatric liver transplantation at our department, 33 patients (36.3%) were diagnosed with CMV infection using the antigenemia method (C7-HRP). Retrospective review and statistical analysis were conducted to confirm risk factors of post-transplantation CMV infection. RESULT: Positive lymphocytes were diagnosed between postoperative days 8 and 111 after transplantation. Ganciclovir or foscavir were administrated to 21 patients. The other 10 patients who had one positive lymphocyte were observed and the cell disappeared on follow-up examination. We did not observe any cases of positive lymphocytes with C7-HRP in patients who received a graft from a CMV antibody-negative donor. Independent predictors associated with CMV infection in the multivariable analysis were administration of OKT3 and grafts from CMV antibody-positive donors. CONCLUSION: In CMV infection after pediatric liver transplantation, cases with CMV antibody-positive donors and with OKT3 administration for acute rejection are considered high risk, and cases with CMV antibody-negative donors are considered low risk.

Acoustic characteristics of voluntary expiratory sounds after swallow for detecting dysphagia.

This research was designed to investigate the acoustic characteristics of voluntary expiratory sounds after swallow for detecting dysphagia. Forty-nine patients with complaints of swallow difficulty received a videofluorographic (VF) examination. They were divided into three groups: nine who did not have any apparent disease (Group N), 22 patients with head and neck cancer (Group H&N) and 18 patients with other diseases including cerebrovascular disease (Group OD). After liquid barium swallows, they exhaled voluntarily without voicing. Videofluorographic findings were classified into four groups: normal (Normal), acceptable swallow (Acceptable), swallow with residue (Resid) and swallows with penetration or aspiration (Pen/Asp). The duration of expiratory sounds was measured on the time waveform. Frequency characteristics of expiratory sounds were obtained using one-third octave band analysis ranging from 62·5 to 2000·0 Hz of central frequency. The averaged level of the 1000·0-Hz band was chosen as the reference band level (RB level). The revised averaged level of each band was obtained by subtracting the RB level from the averaged level of each band. Zero decibel of the revised magnitude of the 125·0-Hz band was set as the critical value to differentiate dysphagia (Resid or Pen/Asp) from no dysphagia (Normal or Acceptable). Comparison of this assessment with VF findings showed a significant percentage agreement (85·4%). These results suggest that frequency characteristics of post-swallow expiratory sounds can differentiate dysphagia from no dysphagia among multiple dysphagic patient groups.

Iron overload after pediatric liver transplantation: a case report.

Iron is an essential nutrient for living cells; however, an excessive accumulation of iron leads to organ damage and directly affects systemic immunity. Iron overload is clinically classified as hereditary or secondary. Most of secondary iron overload is caused by frequent blood transfusions because there is no active mechanism to excrete iron from the body. As recommended in various guidelines, chelation therapy is effective for reducing iron burden and improving organ function. There have been few reports on iron overload through blood transfusion during the perioperative period of liver transplantation. This report presents a case of iron overload due to repeated transfusions after pediatric liver transplantation managed by chelation therapy. The patient, an 11-month-old female with biliary atresia, underwent living donor liver transplantation. She revealed refractory anemia and required frequent blood transfusion. Both serum ferritin and transferrin saturation tended to increase after repeated transfusions, leading to secondary iron overload. Iron chelation therapy was started to prevent progression to organ failure and infection due to iron overload, and yielded a favorable outcome. It is crucial to consider the possibility of secondary iron overload and to achieve early detection and treatment to avoid progression to irreversible organ damage.

Successful treatment of severe anastomotic stricture of a choledochojejunostomy after living donor liver transplantation with transhepatic cholangioscopy-guided balloon dilatation.

Anastomotic stricture of the choledochojejunostomy is a common complication after living donor liver transplantation. Most anastomotic strictures can be treated by percutaneous transhepatic cholangiodrainage and/or double balloon endoscopy. However, in severe cases and/or in small infants, neither of these is possible. Our new technique, cholangiography accompanied by cholangioscopy, enabled successful guidewire placement and balloon dilatation in cases with severe anastomotic stricture.

Genes associated with the progression of neurofibrillary tangles in Alzheimer's disease.

The spreading of neurofibrillary tangles (NFTs), intraneuronal aggregates of highly phosphorylated microtubule-associated protein tau, across the human brain is correlated with the cognitive severity of Alzheimer's disease (AD). To identify genes relevant to NFT expansion defined by the Braak stage, we conducted whole-genome exon array analysis with an exploratory sample set consisting of 213 human post-mortem brain tissue specimens from the entorinal, temporal and frontal cortices of 71 brain-donor subjects: Braak NFT stages 0 (N=13), I-II (N=20), III-IV (N=19) and V-VI (N=19). We identified eight genes, RELN, PTGS2, MYO5C, TRIL, DCHS2, GRB14, NPAS4 and PHYHD1, associated with the Braak stage. The expression levels of three genes, PHYHD1, MYO5C and GRB14, exhibited reproducible association on real-time quantitative PCR analysis. In another sample set, including control subjects (N=30), and in patients with late-onset AD (N=37), dementia with Lewy bodies (N=17) and Parkinson disease (N=36), the expression levels of two genes, PHYHD1 and MYO5C, were obviously associated with late-onset AD. Protein-protein interaction network analysis with a public database revealed that PHYHD1 interacts with MYO5C via POT1, and PHYHD1 directly interacts with amyloid beta-peptide 42. It is thus likely that functional failure of PHYHD1 and MYO5C could lead to AD development.

A comparison of open surgery and endovascular intervention for hepatic artery complications after pediatric liver transplantation.

There are currently 2 major therapeutic options for the treatment of hepatic artery complications: endovascular intervention and open surgery. We herein report a retrospective analysis of 14 pediatric patients with hepatic artery complications after pediatric living donor liver transplantation (LDLT) at our institution. We divided them into an open surgery group and an endovascular intervention group based on their primary treatment, and compared the results and outcomes. We then evaluated which procedure is more effective and less invasive. In the open surgery group, recurrent stenosis or spasm of the hepatic artery occurred in 3 of the 8 patients (37.5%). In the endovascular intervention group, 5 of the 6 patients were technically successfully treated by only endovascular treatment. Of the 5 successfully treated patients, 3 developed recurrent stenosis (60%). There were significant differences in the mean length of the operation for the first treatment of hepatic artery complications (open surgery, 428 minutes vs endovascular intervention, 160 minutes; P = .01) and in the mean value of the posttreatment aspartate aminotransferase (AST)/alanine aminotransferase (ALT) (open surgery > endovascular intervention; P = .04/.05). Although endovascular intervention needs to be examined in further studies to reduce the rate of relapse, it is a less invasive method for the patient and graft than open surgery.

Prediction of acute cellular rejection by peripheral blood eosinophilia in pediatric living donor liver transplantation.

BACKGROUND: Acute cellular rejection (ACR) is a common cause of morbidity following liver transplantation. Several reports have evaluated the predictive value of peripheral blood eosinophilia as a simple noninvasive diagnostic marker for ACR. This study examined whether the relative eosinophil counts (REC) predicted ACR in pediatric living donor liver transplantation (LDLT). METHODS: One hundred three patients underwent LDLT between May 2001 and December 2007. ACR were diagnosed based on the pathological findings. RESULTS: The incidence of ACR was 46.6% (48/103); ACR was diagnosed an average of 13.5 days after LDLT. The average REC at 4 and 2 days before the onset ACR (n = 39) within 30 postoperative day (POD) was 4.3% and 7.3%, respectively, and 9.0% at the onset. Patients with ACR showed significantly higher levels of REC compared with those free of ACR (P = .039). REC thresholds of 10% at POD 7 displayed a sensitivity and specificity of ACR detection of 80% and 75%, respectively. Moreover, the accumulated morbidity ratio of ACR within 30 POD was significantly higher with REC >10% at POD 7 (P = .007). CONCLUSION: ACR within POD 30 should be considered when REC is >10% at POD 7 after LDLT.

Living donor liver transplantation from an asymptomatic mother who was a carrier for ornithine transcarbamylase deficiency.

Liver transplantation (LT) has been adopted as a radical treatment for ornithine transcarbamylase deficiency (OTCD), yielding favorable outcomes. Despite the fact that it is an inheritable disease, a blood relative who is heterozygous for the disorder must sometimes be used as a liver donor for living donor LT. There is ongoing discussion regarding the use of heterozygous donors, however, to our knowledge, no cases where donation was determined based on the Ornithine transcarbamylase (OTC) activity before LT have been reported. Between May 2001 and April 2011, 17 patients were indicated for living donor LT because of OTCD at our facility. There were three cases with heterozygous donor candidate (17.6%). All heterozygous candidates underwent a liver biopsy to measure their OTC activity before LT and made efforts to secure the safety of the both donor and recipient. Two of 3 candidates had headaches sometimes, and their activity was less than 40%, and thus they were not employed as the donor. One candidate with 104.4% activity was employed, yielding favorable outcomes. Our current experience supported the effectiveness of our donation criteria, however it is necessary to collect sufficient data on a large number of patients to confirm the safety of the procedure.

Varicella zoster virus disease after pediatric living donor liver transplantation: is it serious?

OBJECTIVES: The aim of this study was to evaluate patients who developed varicella zoster virus (VZV) disease after pediatric living donor liver transplantation (PLDLT). METHODS: Two hundred fifty-five patients who underwent PLDLT between 1995 and 2010 were included in this study. Pretransplantation vaccination of VZV was performed for all recipients except emergency PLDLTs. Posttransplantation VZV vaccination was administered to the patients with a low VZV antibody titer 2 years or more after transplantation. The clinical course and outcomes of VZV disease in cases were reviewed with the transplant database and hospital medical records. RESULTS: Sixty-three patients developed VZV disease (chicken pox in 61, herpes zoster in 2) at a median onset of 36 months after PLDLT and at a median age of 4 years old, with a cumulative incidence of 25%. All chicken pox occurred in VZV antibody-negative patients. The onset of herpes zoster in the two patients occurred within 3 months after PLDLT; in addition, these patients were VZV antibody-positive patients. The clinical presentations of most patients were not serious and there were no disseminated infections. Although only 3 patients (5%) were hospitalized, the other 60 patients (95%) all showed a good response to oral antiviral therapy. CONCLUSIONS: Although VZV disease is an infectious disease with a high morbidity rate after PLDLT, it can normally be successfully managed on an outpatient basis at home. Pre- and posttransplantation vaccinations are effective for delaying the onset of chicken pox after PLDLT and to prevent it from developing into a serious illness.

Veno-occlusive disease/sinusoidal obstruction syndrome associated with potential antibody-mediated rejection after pediatric living donor liver transplantation: a case report.

A 9-month-old girl with biliary atresia underwent successful living donor liver transplantation from her 42-year-old ABO blood-type incompatible mother. The postoperative course was uneventful until postoperative day (POD) 13 when the recipient displayed an increased volume of drained ascites and decreased her platelet count showing low-velocity portal venous inflow without hepatic venous outflow obstruction. We suspected potential veno-occlusive disease/sinusoidal obstruction syndrome (vod/sos) due to an acute cellular rejection (ACR) episode and performed a liver biopsy (LB). We diagnosed severe episode (Rejection Activity Index Score; P3V3B1 = 7) and started steroid pulse therapy. We performed a second LB on POD 27 because the patient showed weight gain and tender hepatomegaly, diagnosing moderate ACR (P1V3B1 = 5). We started a second course of steroid pulse therapy, but the patient's clinical findings did not improve. On POD 43, her third LB finding showed P1V1B1 with improved processes from ACR, but still displaying severe congestion and fibrotic obliteration of small hepatic veins. We suspected that her immunologic responses were associated with antibody-mediated rejection (AMR) because her anti-HLA class I and class II antibodies were positive by flow panel-reactive antibody method and donor-specific antigen class II and C4d staining were also positive. We added mycophenolate mofetil and administered high-dose intravenous immunoglobulin to control the AMR, and anticoagulant therapy for the VOD/SOS. Her clinical findings and graft venous abnormalities finally improved; she was eventually discharged without sequelae on POD 72.

Superconductivity induced by longitudinal ferromagnetic fluctuations in UCoGe.

From detailed angle-resolved NMR and Meissner measurements on a ferromagnetic (FM) superconductor UCoGe (T(Curie)∼2.5 K and T(SC)∼0.6 K), we show that superconductivity in UCoGe is tightly coupled with longitudinal FM spin fluctuations along the c axis. We found that magnetic fields along the c axis (H∥c) strongly suppress the FM fluctuations and that the superconductivity is observed in the limited magnetic-field region where the longitudinal FM spin fluctuations are active. These results, combined with model calculations, strongly suggest that the longitudinal FM spin fluctuations tuned by H∥c induce the unique spin-triplet superconductivity in UCoGe. This is the first clear example that FM fluctuations are intimately related with superconductivity.