Discrepancy between the survival rate and neuropsychological development in postsurgical extremely low-birth-weight infants: a retrospective study over two decades at a single institution.

PURPOSE: Necrotizing enterocolitis (NEC), focal intestinal perforation (FIP), and meconium-related ileus (MRI) are major diseases that cause gastrointestinal disorders in extremely low-birth-weight infants (ELBWIs). We conducted a review to compare the postoperative outcomes of ELBWIs with these diseases in our neonatal intensive-care unit. METHODS: A retrospective chart review of ELBWIs surgically treated for NEC (n = 31), FIP (n = 35), and MRI (n = 16) in 2001-2018 was undertaken. This period was divided into early (2001-2005), middle (2006-2010), and late (2011-2018) periods. Data were analyzed with the Cochran-Armitage test. Statistical significance was defined as p < 0.05. RESULTS: The survival rates in ELBWIs with NEC (early/middle/late: 36.4%/42.9%/61.5%; p = 0.212) and FIP (20%/50%/70.6%; p = 0.012) improved over time; all patients with MRI survived. The neuropsychological development of 24 cases was assessed with the Kyoto Scale of Psychological Development in the Postural-Motor, Cognitive-Adaptative, and Language-Social domains. The mean developmental quotient of all domains was 68.4 (range 18-95) at corrected 1.5 years of age and 69.1 (range 25-108) at chronological 3 years of age, both were considered as poor development. There was no improvement over time (p = 0.899). CONCLUSION: Ideal neuropsychological development was not observed with the improvement of survival rate. Less-invasive surgical intervention and adequate postoperative care are required to encourage further development.

Size-tunable MRI-visible nitroxide-based magnetic mixed micelles: preparation, stability, and theranostic application.

Metal-free magnetic mixed micelles (mean diameter: 16 nm) composed of biocompatible surfactant Tween 80 and hydrophobic pyrrolidine-N-oxyl radical were prepared by mixing them in phosphate-buffered saline. The magnetic mixed micelles were characterized by dynamic light scattering and small angle neutron scattering measurements. The stability of the micelles is found to depend on the length of alkyl side chain in the nitroxide compounds and degree of unsaturation in the hydrophobic chain in the surfactant. The size of the mixed micelle can be tuned by changing the molar ratio of Tween 80 and nitroxyl radical. In view of theranostic application of the micelle, the cytotoxicity and stability in a physiological environment was investigated; the mixed micelle exhibited no cytotoxicity, high colloidal stability and high resistance towards reduction by large excess ascorbic acid. The in vitro and in vivo magnetic resonance imaging (MRI) revealed sufficient contrast enhancement in the proton longitudinal relaxation time (T 1) weighted images. In addition, hydrophobic fluorophores and an anticancer drug are stably encapsulated in the mixed micelles and showed fluorescence (FL) upon reduction by ascorbic acid and cytotoxicity to cancer cells, respectively. For example, the paclitaxel-loaded mixed micelles efficiently suppressed cancer cell growth. Furthermore, they were found to give higher MRI contrast (higher r 1 value) in vitro than the micelles without paclitaxel. The magnetic mixed micelles presented here are promising theranostic agents in nanomedicine due to their high biocompatibility and high resistivity towards reduction as well as functioning as a drug carrier in therapy and MR or FL imaging probe in diagnosis.

Sensitive electrochemical measurement of hydroxyl radical generation induced by the xanthine-xanthine oxidase system.

A sensitive electrochemical measurement system for hydroxyl radical (OH) was developed using enzyme-catalyzed signal amplification. In the presence of 2,6-xylenol as a trapping agent, glucose as a substrate, and pyrroloquinoline quinone-dependent glucose dehydrogenase (PQQ-GDH) as a catalyst, the amperometric signal of the trapping adduct 2,6-dimethylhydroquinone (DMHQ) produced by the hydroxylation of 2,6-xylenol was able to be amplified and detected sensitively. The limit of detection (signal/noise [S/N]=3) for DMHQ was 1 nM. There was no significant interference from urate and other oxidizable compounds in the reaction mixture at the applied potential of 0V versus Ag/AgCl. This method was employed to observe the OH generation induced by the xanthine-xanthine oxidase (XO) system. The reaction rates of the DMHQ production induced from the xanthine-XO system in the presence and absence of various Fe(III) complexes and proteins were compared. Those with a free coordination site on the Fe atom effectively enhanced the OH generation.

NMR basis for interprotein electron transfer gating between cytochrome c and cytochrome c oxidase.

The final interprotein electron transfer (ET) in the mammalian respiratory chain, from cytochrome c (Cyt c) to cytochrome c oxidase (CcO) is investigated by (1)H-(15)N heteronuclear single quantum coherence spectral analysis. The chemical shift perturbation in isotope-labeled Cyt c induced by addition of unlabeled CcO indicates that the hydrophobic heme periphery and adjacent hydrophobic amino acid residues of Cyt c dominantly contribute to the complex formation, whereas charged residues near the hydrophobic core refine the orientation of Cyt c to provide well controlled ET. Upon oxidation of Cyt c, the specific line broadening of N-H signals disappeared and high field (1)H chemical shifts of the N-terminal helix were observed, suggesting that the interactions of the N-terminal helix with CcO are reduced by steric constraint in oxidized Cyt c, while the chemical shift perturbations in the C-terminal helix indicate notable interactions of oxidized Cyt c with CcO. These results suggest that the overall affinity of oxidized Cyt c for CcO is significantly, but not very much weaker than that of reduced Cyt c. Thus, electron transfer is gated by dissociation of oxidized Cyt c from CcO, the rate of which is controlled by the affinity of oxidized Cyt c to CcO for providing an appropriate electron transfer rate for the most effective energy coupling. The conformational changes in Lys13 upon CcO binding to oxidized Cyt c, shown by (1)H- and (1)H, (15)N-chemical shifts, are also expected to gate intraprotein ET by a polarity control of heme c environment.

Impact of endotoxin measured by an endotoxin activity assay during liver transplantation.

BACKGROUND: Endotoxin (Et) in the portal vein blood is processed by the hepatic reticuloendothelial system. Thus, it is possible that the Et kinetics of the peripheral venous blood may be useful as a biological index that can be used to evaluate liver function. In this study, we measured Et using the endotoxin activity assay in peripheral venous blood during living donor liver transplantation (LDLT), to study its clinical significance. METHODS: Subjects were 17 patients who underwent LDLT. In the perioperative peripheral venous blood, was measured Et activity (EA) using the endotoxin activity assay at 1 or 2 d before LT, and then on 1, 5, 7, 14, and 21 postoperative days. RESULTS: Patients with infections had significantly higher EA levels compared with those without complications before LDLT and 14 postoperative days (P = 0.038 and 0.027, respectively). The average EA level of patients with infections and without complications before LT was 0.22 and 0.08, respectively (P = 0.038). Patients with an EA level higher than 0.20 before LDLT had a significantly longer period of hospitalization compared with those without complications (P = 0.038). CONCLUSIONS: A preoperative EA level more than 0.20 is a high risk factor for post-transplant infection and a prolonged period of hospitalization.

Impact of enzyme activity assay on indication in liver transplantation for ornithine transcarbamylase deficiency.

There are no objective and concrete guidelines for the management of Ornithine transcarbamylase deficiency (OTCD). Based on previous findings, we hypothesized that patients with OTCD have a low Ornithine transcarbamylase (OTC) activity in the liver, and therefore it would be better to determine the appropriate indications and optimal timing for liver transplantation (LT) based on the OTC activity. However, few data have so far been accumulated on the OTC activity in cases that are indicated for LT. The purpose of the present study was to clarify the OTC activity in cases that were indicated for LT. This study involved thirteen children with OTCD (8 males and 5 females) who underwent LT, and two females with OTCD who did not require LT. The OTC activity of the neonatal onset type ranged from 0% to 7.2%, while that of the late onset type who underwent LT ranged from 4.4% to 18.7%. The OTC activity of the late onset type which did not require LT was 33-38% based on a preoperative needle liver biopsy. Some late onset patients that underwent LT, showed an activity that was as low as that observed in the neonatal onset cases. This is the first report to show the results of measuring the OTC activity for serial OTCD cases indicated for LT. OTC activity might be an indicator to determine the indications for and the timing of LT in the late onset type, however, further investigations are necessary.

Redox-controlled backbone dynamics of human cytochrome c revealed by 15N NMR relaxation measurements.

Redox-controlled backbone dynamics in cytochrome c (Cyt c) were revealed by 2D 15N NMR relaxation experiments. 15N T1 and T2 values and 1H-15N NOEs of uniformly 15N-labeled reduced and oxidized Cyt c were measured, and the generalized order parameters (S2), the effective correlation time for internal motion (taue), the 15N exchange broadening contributions (Rex) for each residue, and the overall correlation time (taum) were estimated by model-free dynamics formalism. These dynamic parameters clearly showed that the backbone dynamics of Cyt c are highly restricted due to the covalently bound heme that functions as the stable hydrophobic core. Upon oxidation of the heme iron in Cyt c, the average S2 value was increased from 0.88+/-0.01 to 0.92+/-0.01, demonstrating that the mobility of the backbone is further restricted in the oxidized form. Such increases in the S2 values were more prominent in the loop regions, including amino acid residues near the thioether bonds to the heme moiety and positively charged region around Lys87. Both of the regions are supposed to form the interaction site for cytochrome c oxidase (CcO) and the electron pathway from Cyt c to CcO. The redox-dependent mobility of the backbone in the interaction site for the electron transfer to CcO suggests an electron transfer mechanism regulated by the backbone dynamics in the Cyt c-CcO system.

Lymphocytotoxic crossmatch in pediatric living donor liver transplantation.

To investigate the relationship between the pretransplant LCT results and the outcome after pediatric LDLT in a single center. The clinical data of 76 children undergoing 79 LDLTs including three retransplantations from May 2001 to January 2006 were retrospectively analyzed. All of the children had end-stage liver disease, and their median age was 1.4 yr (range, six months to 16.5 yr). Immunosuppressive therapy consisted of cyclosporine- or FK-based regimens with steroids. The children were classified into two groups (positive or negative) according to the pretransplant LCT results. The incidences of post-transplant surgical complications and of rejection episodes were compared. The relationship between the pretransplant LCT results and patient and graft survival rates was also analyzed. Seventy-nine pretransplant crossmatch tests were done; 13 (16.5%) were positive, and 66 (83.5%) were negative. No significant difference was found in the pretransplant clinical factors between two crossmatch groups. There was no significant difference between the groups in the incidence of vascular and biliary tract complications, in the rate of early or steroid-resistant cellular rejections, or in one- and three-yr patient (91.7%, 91.7%, respectively, in the positive group, 93.5%, 93.5%, respectively, in the negative group, p = 0.80) and graft (92.3%, 92.3%, respectively, in the positive group, 88.8%, 86.4%, respectively, in the negative group, p = 0.63) survival. The present study demonstrates that there is no reason to do pretransplant LCT to select the living donor for pediatric LDLT.

Contribution of hydrolase and phosphatase domains in soluble epoxide hydrolase to vascular endothelial growth factor expression and cell growth.

Soluble epoxide hydrolase (sEH) is an important pharmacological target because it metabolizes potent bioactive substrates, epoxyeicosatrienoinc acids (EETs) and other lipid epoxide. EETs have a variety of biological functions including angiogenesis and cancer metastasis. However, the regulation and physiological function of sEH is not well understood. In this study, we found that hypoxia significantly suppressed the expression of sEH in mouse liver and a human hepatoma cell line, Hep3B. Hypoxia promotes the proliferation of vascular endothelial cells or carcinoma cells. Knockdown of sEH in Hep3B cells induced vascular endothelial growth factor (VEGF) mRNA and cell growth, both of which were suppressed by overexpression of sEH. sEH has phosphatase activity as well as epoxide hydrolase (EH) activity. We prepared mutant clones which lacking EH or phosphatase activity using the amino acid change Asp335Ser or Asp9Ala, respectively. The effects of WT sEH on cell growth were lost by mutation of either the EH domain or phosphatase domain. However, mutation of the phosphatase domain but not EH domain did not influence the expression of VEGF. These results suggest that sEH plays an important role in the physiology of cells including proliferation and that the epoxide hydrolase and phosphatase domains of sEH have different biological functions.

[Multidisciplinary treatment for severe syndromic craniosynostosis].

We describe the treatment of patients having syndromic craniosynostosis with severe craniofacial abnormality. One patient had Cruzon's syndrome, one had Beare-Stevenson cutis gyrata syndrome, and four had Pfeiffers syndrome. Anterior cranial deformity in all patients was treated using fronto-orbital advancement (FOA) by gradual distraction. Initially, the frontal and supraorbital bones were removed and remodeled. Next, the frontal bones were fixed loosely to the supraorbital bones with absorbable threads. Then, the supraorbital and temporal bones were connected using distraction devices on both sides. The temporal bones were thereafter reinforced with titanium plates. Distraction was started one week postoperation, and the mean amount of elongation was 28.9 mm. Distraction devices were removed one to five months after the operation. One case required FOA by the traditional method ten months after the initial operation. Local infection was observed in three cases, but there were no majors complications. Posterior cranial remodelings were performed in five cases, with one requiring a second operation. We chose the appropriate procedure according to the degree of cranial deformity and operative findings. We performed decompression of the foramen magnum in five cases and laminectomy of the atlas in two cases. Ventriculoperitoneal shunt for hydrocephalus and tracheotomy for airway obstruction were performed in all cases. Cranial remodeling for treating severe craniofacial abnormality requires careful inspection of abnormalities, proper timing, close attention to the procedure and adequate perioperative care. Multidisciplinary therapy is essential for treating severe syndromic craniosynostosis due to systematic osseocartilaginous aplasia.

The einkorn wheat (Triticum monococcum) mutant, maintained vegetative phase, is caused by a deletion in the VRN1 gene.

The einkorn wheat (Triticum monococcum) mutant, maintained vegetative phase (mvp), was induced by nitrogen ion-beam treatment and was identified by its inability to transit from the vegetative to reproductive phase. In our previous study, we showed that WAP1 (wheat APETALA1) is a key gene in the regulatory pathway that controls phase transition from vegetative to reproductive growth in common wheat. WAP1 is an ortholog of the VRN1 gene that is responsible for vernalization insensitivity in einkorn wheat. The mvp mutation resulted from deletion of the VRN1 coding and promoter regions, demonstrating that WAP1/VRN1 is an indispensable gene for phase transition in wheat. Expression analysis of flowering-related genes in mvp plants indicated that wheat GIGANTIA (GI), CONSTANS (CO) and SUPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) genes either act upstream of or in a different pathway to WAP1/VRN1.

Impact of hepatic clearance of endotoxin using endotoxin activity assay.

BACKGROUND: Endotoxin (Et) in the portal vein blood is processed by the hepatic reticuloendothelial system, and therefore, it is possible that the hepatic clearance of Et may become a biological index for liver function. In this study, Et levels of preoperative peripheral and portal vein blood at the time of liver transplantation (LT) were measured in order to study the meaning. METHODS: The study population comprised 19 patients in whom pediatric living donor LT was performed. In the preoperative peripheral and the portal vein blood at the time of LT, we measured Et activity (EA) by the Et activity assay (EAA) and the Limulus amebocyte lysate (LAL) method. RESULTS: The preoperative peripheral vein blood showed a low EA in all cases. In the EA of the peripheral and the portal vein blood, the latter showed a significantly high level (p = 0.049). With the LAL method, 5.3% (2/38) of patients were positive for Et. CONCLUSIONS: The EAA is considered to be superior to the LAL method for the detection of Et, even in low endotoxinemia, and is also capable of elucidating the Et kinetics by accurately reflecting hepatic clearance.

The role of operative intervention in management of congenital extrahepatic portosystemic shunt.

BACKGROUND AND AIMS: Congenital extrahepatic portosystemic shunt (CEPS) is a rare venous malformation in which mesenteric venous blood drains directly into the systemic circulation. It is still a matter of debate whether conservative or operative strategies should be used to treat symptomatic CEPS. The aim of this study was to evaluate the role of operative intervention in the management of CEPS. METHODS: Between June 2004 and August 2010, 6 consecutive patients with symptomatic CEPS were treated in our department. There were 3 male and 3 female patients, with a median age of 3.5 years (range, 1-8). Their demographic, clinical, and laboratory data were analyzed. All patients were scheduled to undergo shunt ligation or liver transplantation (LT). RESULTS: Living donor LT was carried out in 4 patients, and shunt ligation in 2. After a median follow-up of 25 months, all the patients are alive currently with marked relief of symptoms. CONCLUSION: Shunt ligation or LT for symptomatic CEPS is potentially curative.

Overexpression of CYP3A4, but not of CYP2D6, promotes hypoxic response and cell growth of Hep3B cells.

Cytochrome P450s (P450s) contribute to carcinogenesis by activating procarcinogens and also metabolize anti-cancer drugs. The activity and protein levels of P450s are important in cancer risk and in cancer therapy. In this study, we found that overexpression of CYP3A4 induced growth of a human hepatoma cell line, Hep3B. Overexpression of CYP2D6, by comparison, decreased cell growth. An inhibitor of CYP3A4, ketoconazole, significantly suppressed the growth of Hep3B cells overexpressing CYP3A4, but an inhibitor of CYP2D6, quinidine, did not restore Hep3B cell growth to baseline levels. Overexpression of CYP3A4 increased the production of reactive oxygen species, but this was not the cause of the CYP3A4-induced growth. Previously, we showed that CYP3A4 can produce epoxyeicosatrienoic acids (EETs) from arachidonic acid. The CYP3A4-enhanced cell growth was attenuated by a putative EET receptor antagonist, 14,15-EEZE. CYP3A4 promoted progression of the cell cycle from the G1 to the S phase. CYP3A4 also induced a hypoxic response of Hep3B cells, detected as enhanced erythropoietin gene expression (a typical hypoxic response). The cell growth promoted by CYP3A4 was inhibited by PI3K inhibitor LY294002. These results suggest that CYP3A4 plays an important role in tumor progression, independent of the activation of carcinogens and metabolism of anti-cancer drugs.

Probing phenylalanine environments in oligomeric structures with pentafluorophenylalanine and cyclohexylalanine.

Stabilization of protein structures and protein-protein interactions are critical in the engineering of industrially useful enzymes and in the design of pharmaceutically valuable ligands. Hydrophobic interactions involving phenylalanine residues play crucial roles in protein stability and protein-protein/peptide interactions. To establish an effective method to explore the hydrophobic environments of phenylalanine residues, we present a strategy that uses pentafluorophenylalanine (F5Phe) and cyclohexylalanine (Cha). In this study, substitution of F5Phe or Cha for three Phe residues at positions 328, 338, and 341 in the tetramerization domain of the tumor suppressor protein p53 was performed. These residues are located at the interfaces of p53-p53 interactions and are important in the stabilization of the tetrameric structure. The stability of the p53 tetrameric structure did not change significantly when F5Phe-containing peptides at positions Phe328 or Phe338 were used. In contrast, the substitution of Cha for Phe341 in the hydrophobic core enhanced the stability of the tetrameric structure with a T(m) value of 100 degrees C. Phe328 and Phe338 interact with each other through pi-interactions, whereas Phe341 is buried in the surrounding alkyl side-chains of the hydrophobic core of the p53 tetramerization domain. Furthermore, high pressure-assisted denaturation analysis indicated improvement in the occupancy of the hydrophobic core. Considerable stabilization of the p53 tetramer was achieved by filling the identified cavity in the hydrophobic core of the p53 tetramer. The results indicate the status of the Phe residues, indicating that the "pair substitution" of Cha and F5Phe is highly suitable for probing the environments of Phe residues.

Indication of liver transplantation for jaundice-free biliary atresia with portal hypertension.

BACKGROUND: At the present time, indications of liver transplantation (LT) for jaundice-free biliary atresia (BA) patients include intractable cholangitis, portal hypertension and pulmonary vascular disorders. However, the timing of LT remains unclear. In the current study, we describe the therapeutic strategies for jaundice-free BA patients. MATERIAL/METHODS: 129 BA patients were undergone LDLT between May, 2001 and April, 2010 in the Department of Transplant Surgery, Jichi Medical University, Japan. RESULTS: The indications of LDLT for jaundice-free BA patients was 30 patients (30/129, 23%), and included portal hypertension (16 patients, 53%). Among the 16 patients with portal hypertension, there were 7 patients (7/16, 23%) in which uncontrollable gastrointestinal bleeding was an indication of LDLT. There were 5 patients (5/7; 71%) in which bleeding sites were not identified, and 3 patients (3/7; 43%) in which supportive treatments against collateral vessels were performed as a previous treatment. CONCLUSIONS: Even in jaundice-free BA patients, after supportive treatments for portal hypertension are performed, it is necessary to assess the esophageal and gastrointestinal varices regularly and to also prepare for LT simultaneously because there is a probability of the complication of uncontrollable gastrointestinal bleeding.

Growth curves of pediatric patients with biliary atresia following living donor liver transplantation: factors that influence post-transplantation growth.

We evaluated the growth curves of children with BA after LDLT, and identified factors influencing growth velocity one-yr after LDLT (DeltaZ). The clinical data of 51 children with BA, who had an LDLT at our center from 2001 to 2005, were retrospectively reviewed. The Z scores for height and weight, and DeltaZ were studied. The correlation between DeltaZ and various clinical factors was evaluated statistically. Multivariate stepwise analyses were performed for DeltaZ. The average height and weight Z scores at the time of LDLT were -1.34 +/- 1.36 (+/-s.d.) and -0.78 +/- 1.15, respectively. Among 30 BA recipients with stable liver function after transplant, weight returned to normal one-yr post-transplantation. However, height did not return to normal even by the third post-transplantation year. On multivariate analyses, 73% of the variance in height DeltaZ could be accounted for by factors such as standardized height at the time of LDLT (proportion of variance: 38%), number of steroid pulse treatments (17%), donor age (10%), and the presence of HVS (9%). Fifty-four percentage of the variance in weight DeltaZ could be accounted for by factors such as standardized weight at the time of LDLT (37%) and the total steroid dose given (17%). Height and weight status at the time of LDLT likely have the strongest impact on DeltaZ. Additional factors include steroid exposure, age of the living donor, and presence of HVS, all of which should be considered to improve post-transplantation growth.

Successful pediatric living donor liver transplantation from carrier to carrier of hereditary butyrylcholinesterase variant.

Hypocholinesterasemia is often observed clinically, especially in various liver diseases. Not well known, however, is the fact that some patients have a hereditary BChE variant. Little has been reported on liver transplants associated with this hereditary BChE variant. Furthermore, no cases have been reported of a LDLT involving hereditary BChE variant that had been diagnosed preoperatively. A 23-month-old girl who had had a failed Kasai operation for biliary atresia underwent a liver transplant using as a graft her father's lateral segment. Preoperatively, she had been diagnosed with hypocholinesterasemia. As the donor, her father had undergone a preoperative examination, during which he was found to also have hypocholinesterasemia. DNA sequencing revealed that both had the hereditary BChE variant. The unique mutation caused a frame-shift mutation. Variant K was also detected. The patient was discharged 143 days after the operation and has had no problems with immunosuppression since. In conclusion, we report that the hereditary BChE variant is not a contraindication for either transplantation or living liver donation.

Dehydration in the folding of reduced cytochrome c revealed by the electron-transfer-triggered folding under high pressure.

We determined the activation volume associated with protein folding of reduced cytochrome c from the collapsed intermediate to the native state. The folding rate was followed by a change in the absorption (420 nm) at various pressures between 0.1 and 200 MPa and at various concentrations of denaturant (guanidine hydrochloride) between 3.2 and 4.0 M. Dependence of the folding rate on both these factors revealed that the activation volume at ambient pressure in the absence of denaturant is negative (DeltaVf0 = -14 (+/-8) cm3.mol-1). Such a negative activation volume can be accounted for by a decrease in volume resulting from the dehydration of hydrophobic groups, primarily the heme group. Dehydration, which increases the entropy of the protein system, compensates for a decrease in the entropy accompanying the formation of the more compact and ordered transition state. We, therefore, propose that the positive change in the activation entropy for the folding reaction is due to the dehydration of hydrophobic groups. Furthermore, dehydration entropically promotes the protein folding reaction.