P4384Noninvasive and novel method to evaluate left ventricular contractility using pressure-volume loop area obtained by 3-dimensional speckle tracking echocardiography

Introduction

Left ventricular (LV) pressure-volume (P-V) loop area reflects stroke work (SW), but clinical use of this index is limited by the need of invasive pressure measurement. A noninvasive method to obtain LV pressure-strain loop was recently introduced to assess myocardial work (MW). The minimum LV diastolic pressure (mLVP) was reported to have a strong correlation with Tau and we reported that Tau was noninvasively evaluated by speckle tracking echocardiography (STE).

Purpose

We sought to evaluate the impact of preload change by leg lifts on LV SW noninvasively obtained by the novel method and to examine the utility to assess LV contractility by SW and end-diastolic (ED) volume relation (SW-VED).

Methods

Thirty six controls (age 71±10) and 30 patients with heart failure with reduced ejection fraction (EF) <50% (HF) (age 73±6) were enrolled. LV pressure in a cardiac cycle was estimated using systolic blood pressure (SBP), minimum diastolic pressure (mDP) and ED pressure (EDP) by utilizing the profile of an empiric, normalized reference curve. The mDP and EDP were estimated as (Tau − 33.7)/2.06 and as 12.3 − 10.1 x Log (left atrial active emptying function/minimum volume) as we reported. LVSW was obtained by P-V loop by the combination of these pressures and LV volume using 3-D STE.

Results

LVEF and longitudinal strain in HF before leg up by 3D-STE were lower compared to normal (LVEF; normal: 58±5 vs HF: 39±10*% and strain; −12±3 vs −8±3%*, *p<0.05 vs normal). LVEF was increased after leg up by 7±6% in normal and by 8±8% in HF associated with increased LVED volume (normal: 84±24 to 90±24 and HF: 124±36* to 136±42*ml). LV MW and SW in HF before leg up were lower compared to normal (MW: 1790±412 vs 1002±432*mmHg% and SW: 3946±1682 vs 3352±1026mmHgml). LV SW increased after leg up by 26±19% in normal and by 25±20% in HF. LV SW-VED in normal was greater than HF (241±151 vs 90±54*).

Conclusion

LV SW noninvasively obtained by P-V loop area was increased after leg up in both normal and HF but SW-VED in HF was smaller than normal, indicating reduced contractility in HF. This noninvasive method may be a new echocardiographic approach for quantification of LV SW and contractility.

P3548Noninvasive estimation of left ventricular diastolic function in patients with hypertension and normal ejection fraction using 3-dimensional speckle tracking echocardiography

Background

Left ventricular (LV) relaxation (eTau) and pulmonary capillary wedge pressure (ePCWP) were reported to be estimated by speckle tracking echocardiography (STE). LV camber stiffness (e-c stiffness) may be estimated with the use of 2 diastolic pressure-volume coordinates. The minimum diastolic pressure (mP) is reported to have a strong correlation with Tau.

Purpose

We sought to examine the impact of hypertension on LV diastolic function and LA properties and to elucidate the feature of hypertensive heart failure with preserved EF (HFpEF).

Methods

The e', E/e', Tau, PCWP, LVEDP, LV stiffness, LAV, LA emptying function (LAEF) and LA strain were examined in 53 controls (age 66±11), 136 hypertensive patients (HTN) with normal EF (69±11) and 39 HFpEF (77±14). ePCWP and estimated EDP (eEDP) was calculated as previously reported. Tau was calculated as isovolumic relaxation time/(ln 0.9 x systolic blood pressure − ln PCWP). Myocardial stiffness (e-m stiffness) was estimated as LVED stress/LV strain. LV c-stiffness was calculated as LV pressure change (from mP to EDP) obtained by catheterization divided by LV volume change. Estimated LV c-stiffness (e-c-stiffness) was noninvasively obtained using e-mP and e-EDP. The eTau, eEDP and e-mP by STE were validated by catheterization (n=126).

Results

The mP had a good correlation with Tau (r=0.70, p<0.01). The eTau, eEDP and e-mP by STE had a good correlation with those by catheterization (r=0.75, 0.63 and 0.70, p<0.01). Multivariate analysis revealed that ePCWP and LA strain were independent predictors of HFpEF.

LV diastoric function Variables Control HTN HFpEF LVEF, % 68±6 68±8 63±9*+ LV longitudinal strain x (s–1) 19.1±3.0 16.8±4.3* 14.5±5.1*+ E/e' 9.2±2.6 11.6±4.5* 15.9±7.9*+ eTau, ms 35±12 48±17* 59±17*+ ePCWP, mmHg 7.3±2.7 8.3±4.3 15.0±4.4*+ eLVEDP, mmHg 9.4±2.2 10.4±3.5 15.9±3.7*+ LV e-myocardial stiffness, kdynes/cm 0.56±0.25 0.69±0.56 1.27±0.71*+ LV e-chamber stiffness, mmHg/ml 0.19±0.06 0.20±0.08 0.36±0.19*+ Maximum LAVI, ml/m2 42±15 50±21* 68±17*+ Total LAEF, % 55±7 51±11 36±12*+ LA peak strain 41±15 40±17 19±8*+ *p<0.05 vs Control, +p<0.05 vs HTN.

Conclusion

We demonstrated that LV diastolic function in HTN may be accurately and noninvasively evaluated by STE.

P2474Noninvasive estimation of pulmonary capillary wedge pressure by novel 3D speckle tracking echocardiography and validation study by cardiac catheterization

Background

We previously reported that pulmonary capillary wedge pressure (PCWP) was noninvasively evaluated by 2D speckle tracking echocardiography (STE). Recently, novel software was introduced to examine volume and function of left ventricular and left atrium (LA) by 3D-STE automatically.

Purpose

We sought to compare the PCWP estimated by conventional 2D-STE (2D-ePCWP) and by novel 3D-STE (3D-ePCWP), and validate those values by cardiac catheterization.

Methods

Echocardiography and catheterization were performed in 29 patients (age 72±2) (7 ischemic heart disease, 2 hypertensive heart disease, 5 dilated cardiomyopathy, 12 valvular heart disease and 3 primary pulmonary hypertension).The ePCWP (mmHg) is noninvasively obtained as 10.8 − 12.4 x Log (left atrial active emptying function/minimum volume) as we previously reported. Echocardiography was performed just before the catheterization and we analyzed the 2D and 3D data by novel off-line software. 3D data was automatically analyzed and the border settings were fixed at default (ES60, ED30) (Figure).

Results

2D-ePCWP and 3D-ePCWP had a good correlation with PCWP invasively obtained by catheterization (r=0.87 and 0.83, respectively, both p<0.001). There was an excellent correlation between 2D-ePCWP and 3D-ePCWP (r=0.94, p<0.001) and there was a good correlation between 2D-LA volume index and 3D- LA volume index (r=0.80, p<0.001). Bland-Altman analysis revealed a good agreement between 2D-ePCWP and 3D-ePCWP, and between 2D-ePCWP and 3D-ePCWP without fixed and proportional bias.

Conclusion

This study demonstrated that PCWP might be noninvasively assessed by not only 2D-STE but also 3D-STE with reasonable accuracy and 3D-STE might have utility and value in the routine clinical practice.

P4351Validation by cardiac catheterization of noninvasive evaluation of left ventricular chamber and myocardial stiffness as a diastolic function using speckle tracking echocardiography

Background

Left ventricular (LV) diastolic function is mainly composed of LV relaxation and LV stiffness. We reported that pulmonary capillary wedge pressure (ePCWP) and LV relaxation assessed by Tau (eTau) are noninvasively evaluated by speckle tracking echocardiography (STE). The minimum LV diastolic pressure (mLVP) was reported to have a strong correlation with Tau. Therefore, LV chamber stiffness (c-stiffness) may be assessed with the use of two LV diastolic pressure-volume coordinates: the mLVP and volume and the end-diastolic pressure (EDP) and volume.

Purpose

We sought to noninvasively assess LV stiffness using STE and validate the value by cardiac catheterization.

Methods

Echocardiography and catheterization were performed in 124 patients (age 72±8) (70 angina pectoris, 20 prior myocardial infarction, 19 hypertensive heart disease, 11 congestive heart failure and 4 paroxysmal atrial fibrillation). The ePCWP (mmHg) is noninvasively obtained as 10.8 − 12.4 × Log (left atrial active emptying function/minimum volume) and the eTau (ms) is obtained as isovolumic relaxation time/(ln 0.9 × systolic blood pressure − ln ePCWP) as previously reported. The mLVP (e-mLVP) was estimate using Tau. The estimated EDP (e-EDP) was calculated as 12.3 − 10.1 × Log (left atrial active emptying function / minimum volume). LV c-stiffness (mmHg/ml) was calculated as LV pressure change (from mLVP to EDP) obtained by catheterization divided by LV volume change during diastole which equals to stroke volume by echocardiography. Estimated c-stiffness (e-c-stiffness) was noninvasively obtained using e-mLVP and e-EDP. Furthermore, LV myocardial stiffness (m-stiffness) was calculated by LVED stress / LV longitudinal strain by STE, where LV stress (kdynes/cm2) was calculated as 0.334 × pressure × dimension / [thickness (1 + thickness/dimension)]. The estimated m-stiffness (e-m-stiffness) was calculated using e-EDP.

Results

The eTau and e-EDP estimated by STE had a good correlation with Tau and EDP invasively obtained by catheterization (r=0.75 and 0.63, respectively, both p<0.001). There was a good correlation between Tau and mLVP (Tau = 2.06 mLVP + 33.7, r=0.70). The estimated LVED stress had good correlation with ED stress obtained by catheterization (r=0.77, p<0.001). The e-c-stiffness and e-m-stiffness had a good correlation with those obtained by catheterization (e-c-stiffness; 0.116±0.07 and c-stiffness; 0.115±0.06, r=0.603, e-m-stiffness; 0.81±0.41 and m-stiffness; 0.85±0.45, r=0.89, respectively). Bland-Altman analysis revealed a good agreement between e-c-stiffness and c-stiffness, and between e-m-stiffness and m-stiffness without fixed and proportional bias.

Conclusion

This study demonstrated that LV stiffness may be noninvasively assessed by STE with reasonable accuracy and may have utility and value in the routine clinical practice for the diagnosis and treatment in patients with diastolic dysfunction.

Refractory Hypotension during Combined General and Epidural Anaesthesia in a Patient on Tricyclic Antidepressants

We report a case of refractory hypotension that occurred after epidural injection of local anaesthetic, in a patient who was receiving tricyclic antidepressant therapy and was under general anaesthesia. The patient failed to respond to repeated injections of appropriate doses of sympathomimetics, but did respond to high-dose catecholamine infusions. We suggest that epidural anaesthesia should be used with care when combined with general anaesthesia for patients on long-standing tricyclic antidepressant therapy. If refractory hypotension should occur in such patients, the use of direct-acting vasoconstrictors such as noradrenaline should be considered.

Changes in Muscle Strength and Six-Minute Walk Distance Before and After Living Donor Liver Transplantation

BACKGROUND

Impaired exercise capacity and muscle weakness are important characteristics of liver transplantation recipients. Perioperative rehabilitation has been introduced to promote early mobilization of patients and to prevent postoperative pulmonary complications. However, it is unknown how physical status recovers during the hospital stay after a liver transplant. The purpose of this study was to evaluate the changes in clinical indicators that represent the functional exercise capacity and muscle strength before and after living donor liver transplantation (LDLT).

METHODS

We retrospectively reviewed 21 consecutive patients who underwent LDLT with perioperative rehabilitation from April 2014 to December 2015. Twelve patients who were tested for 6-minute walk distance, hand-grip strength, and isometric knee extensor muscle strength before and 4 weeks after LDLT were enrolled.

RESULTS

At the preoperative baseline, the 6-minute walk distance significantly correlated with the Model for End-stage Liver Disease score and pulmonary functions (vital capacity, forced vital capacity, and forced expiratory volume in 1 second of predictive values). Comparisons between the preoperative and postoperative values revealed significant decreases in weight, Barthel Index, hand-grip strength, and isometric knee extensor muscle strength. Changes in hand-grip strength and isometric knee extensor muscle strength after LDLT correlated with the preoperative Model for End-stage Liver Disease score.

CONCLUSIONS

Physical functional status had not been fully recovered 4 weeks after LDLT. Further investigation regarding developing a strategy for prevention of muscle atrophy before LDLT and recovery of physical fitness after LDLT would be helpful.

An Effective New Cryopreservation Procedure for Pancreatic Islets Using Hollow Fiber Vitrification

The present study aimed at establishing a new cryopreservation method for mouse pancreatic islets by vitrification using hollow fibers as a container. A unique feature of the hollow fiber vitrification (HFV) method is that this method achieves stable vitrification using a minimum volume of cryoprotectant (CPA) solution, thereby ensuring high viability of the islets. The cytotoxicity, optimum composition, and concentration of the CPAs for vitrifying islets were examined. The viability, functional-integrity of vitrified islets were evaluated in comparison with those vitrified by conventional methods. Insulin secretion was measured in vitro by a static incubation assay and the metabolic functions was tested after transplantation into Streptozotocin-induced diabetic mice. The combination of 15% dimethyl sulfoxide+15% ethylene glycol resulted in the best CPA solution for the HFV of islets. HFV showed the highest viability in comparison to 2 vitrification methods, open pulled straws and vitrification with EDT324 solution. The vitrified islets stably expressed β-cells markers NeuroD, Pancreatic and duodenal homeobox-1, and MafA. Transplantation of the vitrified islets achieved euglycemia of the host diabetic mice and response to an intraperitoneal glucose tolerance test to a similar extent as non-vitrified transplanted islets. The HFV method allows for efficient long-term cryopreservation of islets.

31 PRODUCTION EFFICIENCY OF GENE KNOCKOUT PIGS USING GENOME EDITING AND SOMATIC CELL CLONING

Genome editing technologies have been used as a powerful strategy for the generation of genetically modified pigs. We previously developed genetically modified clone pigs with organogenesis-disabled phenotypes, as well as pigs exhibiting diseases with similar features to those of humans. Here, we report the production efficiency of various gene knockout cloned pigs from somatic cells that were genetically modified using zinc finger nucleases (ZFN) or transcription activator-like effector nucleases (TALEN). The ZFN- or TALEN-encoding mRNAs, which targeted 7 autosomal or X-linked genes, were introduced into porcine fetal fibroblast cells using electroporation. Clonal cell populations carrying induced mutations were selected after limiting dilution. The targeted portion of the genes was amplified using PCR, followed by sequencing and mutation analysis. Among the collected knockout cell colonies, cells showing good proliferation and morphology were selected and used for somatic cell nuclear transfer (SCNT). In vitro-matured oocytes were obtained from porcine cumulus-oocyte complexes cultured in NCSU23-based medium and were used to obtain recipient oocytes for SCNT after enucleation. SCNT was performed as reported previously (Matsunari et al. 2008). The cloned embryos were cultured for 7 days in porcine zygote medium (PZM)-5 to assess their developmental ability. Cloned embryos were transplanted into the oviduct or uterus of oestrus-synchronized recipient gilts to evaluate their competence to develop to fetuses or piglets. Cloned embryos reconstructed with 7 types of knockout cells showed equal development to blastocysts compared with those derived from the wild-type cells (54.5–83.3% v. 60.7%). Our data (Table 1) demonstrated that the reconstructed embryos derived from knockout cells could efficiently give rise to cloned offspring regardless of the type of genome editing methodology (i.e. ZFN or TALEN). Table 1.Production efficiency of gene knockout cloned pigs using genome editing This study was supported by JST, ERATO, the Nakauchi Stem Cell and Organ Regeneration Project, JST, CREST, Meiji University International Institute for Bio-Resource Research (MUIIBR), and JSPS KAKENHI Grant Number 26870630.

26 IN VIVO EXOGENIC ORGAN GENERATION WITH ORGANOGENESIS-DISABLED CLONED PIGS AS A PLATFORM

The generation of organs from pluripotent stem cells (PSC) is one of the ultimate goals of regenerative medicine. We have demonstrated that functional organs can be generated in vivo from xenogenic PSC in the body of organogenesis-disabled mice using blastocyst complementation. To apply this principle in generating human organs, a technical platform using large non-rodent mammals is essential. The aim of the present study was to establish a blastocyst complementation system using cloned pig embryos. We generated transgenic-cloned pigs with an apancreatic phenotype via the overexpression of Hes1 (hairy and enhancer of split-1) under the Pdx1 promoter (pancreatic and duodenal homeobox-1). Cloned embryos of apancreatic pigs (host embryos, male) were complemented (i.e. chimerized) by blastomeres of cloned embryos (donor cells, female) with normal developmental competence. Chimeric embryos were cultured for 1 or 2 days before being transferred into the uteri of oestrus-synchronized gilts. The complementation of 292 Pdx1-Hes1 cloned embryos gave rise to 260 (89.0%) blastocysts. The transfer of these blastocysts resulted in 5 male chimeric pigs. Chimerism was confirmed by the detection of host embryo-derived Pdx1-Hes1 and marker transgenes of the donor cells, such as humanized Kusabira-Orange (huKO) or Pdx1-Venus. Chimeric pigs possessed normally formed pancreata entirely derived from the exogenous donor cells. We thus established a blastocyst complementation system in the pig using cloned embryos that would otherwise give rise to apancreatic animals. Chimeric pigs obtained developed normally, maintaining normal serum glucose concentrations up to maturity, and became fertile boars. Mating the chimeric boars with 7 wild-type sows gave rise to 72 fetuses/piglets of which 37 (51.4%) exhibited the apancreatic phenotype. These results indicate that a missing organ can be generated from exogenous cells when functionally normal pluripotent cells chimerize with a cloned dysorganogenetic embryo. Blastocyst complementation using cloned porcine embryos may permit the use of a large animal for the generation of functional organs from xenogenic PSC, including human iPSC. The chimeric boar produced by blastocyst complementation sired fetuses/offspring with the apancreatic phenotype in a Mendelian fashion. Porcine fetuses with an organogenesis-disabled phenotype may provide a useful platform for organ regeneration research. Table 1.Production of chimeric pigs by complementation and of Pdx1-Hes1 cloned embryos

20 GENERATION AND CHARACTERIZATION OF TRANSGENIC-CLONED PIGS EXPRESSING THE FAR-RED FLUORESCENT PROTEIN MONOMERIC PLUM

Transgenic (Tg) pigs expressing a fluorescent protein are extremely useful for research into transplantation and regenerative medicine. This study aimed to create Tg pigs expressing monomeric Plum (mPlum), a far-red fluorescent protein with a longer wavelength than enhanced green fluorescent protein (EGFP) and humanized Kusabira Orange (huKO), the two fluorescent proteins that have been used previously for Tg pig production. A linearized CAG-mPlum transgene construct was transferred into porcine fetal fibroblasts (PFF) by electroporation. mPlum fluorescence-positive cells were collected using a cell sorter and used as nuclear donors (mPlum-PFF) for somatic cell nuclear transfer (SCNT). In vitro-matured oocytes were obtained from porcine cumulus–oocyte complexes cultured in NCSU23-based medium and were used to obtain recipient oocytes for SCNT after enucleation. Then, SCNT was performed as reported previously (Matsunari et al., 2008). The reconstructed embryos were cultured for 7 days in porcine zygote medium-5 (PZM-5). mPlum fluorescence expression was screened during the early development of the embryos. After 5 or 6 days of culture, the SCNT embryos were surgically transferred to the uterus of a recipient gilt. We first obtained fetuses on Day 36 or 37 of gestation by Caesarean section and the PFF were retrieved from their skin. Fluorescence expression was analysed using fluorescence microscope, and the number of transgene copies in each fetus was determined by Southern blot analysis. We also analysed whether unique spectral properties of mPlum are suitable for multicolor imaging using confocal microscope and flow cytometer. The identification of mPlum-expressing PFF under the mixed culture of PFF expressing EGFP and huKO was examined. The 2 cell lines of PFF expressing EGFP and huKO were previously generated in our laboratory. Rates of normal cleavage and blastocyst formation occurred in the SCNT embryos generated with mPlum-PFF (mPlum embryos) were equivalent to those of SCNT embryos derived from nontransgenic PFF (34/42, 81.0%; 33/42, 78.6% v. 37/40, 92.5%; 30/40, 75.0%). Total cell numbers in mPlum and control blastocysts did not differ significantly (88.3 ± 6.0 v. 99.9 ± 8.8). Fluorescence expression in the mPlum embryos began at the 8-cell stage and became brighter from the morula stage. The gilt into which 103 mPlum embryos were transferred produced 3 fetuses. These fetuses expressed mPlum fluorescence systemically and had 1 to 5 copies of the transgene. Multicolor fluorescence imaging and flow cytometric analyses of a mixed culture of mPlum PFF and PFF expressing EGFP and huKO showed that clear identification and isolation of cells displaying each of the 3 fluorescence signals was possible. These observations demonstrate that the transfer of CAG-mPlum did not interfere with the development of porcine SCNT embryos and resulted in the successful generation of Tg cloned pigs that systemically expressed mPlum. This work was supported by JSPS KAKENHI Grant Number 25293279.

Advancing pig cloning technologies towards application in regenerative medicine

Regenerative medicine is expected to make a significant contribution by development of novel therapeutic treatments for intractable diseases and for improving the quality of life of patients. Many advances in regenerative medicine, including basic and translational research, have been developed and tested in experimental animals; pigs have played an important role in various aspects of this work. The value of pigs as a model species is being enhanced by the generation of specially designed animals through cloning and genetic modifications, enabling more sophisticated research to be performed and thus accelerating the clinical application of regenerative medicine. This article reviews the significant aspects of the creation and application of cloned and genetically modified pigs in regenerative medicine research and considers the possible future directions of the technology. We also discuss the importance of reproductive biology as an interface between basic science and clinical medicine.

297 PRODUCTION OF CHIMERIC PORCINE FETUSES BY AGGREGATION METHOD USING PARTHENOGENETIC EMBRYOS

Porcine induced pluripotent stem (iPS) cells are considered to be an invaluable research tool in translational research with pigs as a large animal model. Pluripotency of the iPS cells needs to be verified by their competence to contribute to chimera formation. The aim of the present study is to establish feasible system to create chimeric pig fetuses using parthenogenetic embryos. In Experiment 1, inner cell mass (ICM) was isolated by immunosurgery from Day 6 blastocysts obtained by parthenogenetic activation of in vitro matured (IVM) oocytes. Isolated ICM were used as the donor cells after staining with fluorescent carbocyanine dye (DiI). Using parthenogenetic morulae or 4- to 8-cell embryos as the host embryos, chimeric embryos were prepared by injection or aggregation method. Injection of ICM was performed by micromanipulation: a single ICM was directly injected into the centre portion of the host morulae. In the aggregation method, a single ICM was aggregated with blastomeres isolated from 2 host embryos at the morula or 4- to 8-cell stage in a micro-well (400 µm diameter, 300 µm deep). The chimeric embryos were cultured in PZM-5 (Yoshioka et al. 2008) for 2 to 3 days to examine development to blastocysts and incorporation of donor ICM cells into the resultant blastocysts ICM (ICM chimerism). In Experiment 2, donor blastomeres isolated from a parthenogenetic morula or 4- to 8-cell embryo were stained by DiI and aggregated with a parthenogenetic host embryo at the morula or 4- to 8-cell stage, and the in vitro development to the blastocyst stage and the ICM chimerism were examined. In Experiment 3, ICM isolated from IVF blastocysts harboring humanized Kusabira-Orange (huKO) gene were used as donor cells. Donor ICM were aggregated with the host embryos at the morula or 4- to 8-cell stage, and the resultant blastocysts were transferred to 4 recipient gilts to collect fetuses on Day 18. Results of Experiments 1 and 2 are summarised in Table 1. Combination of the donor ICM and host morulae yielded high rates of blastocyst formation (~95%) and ICM chimerism (~85%), regardless of the method used (injection or aggregation). Transfer of 73 blastocysts developed from host morulae to 2 recipients (Experiment 3) gave rise to 25 (34.2%) fetuses, of which 6 (24.0%) were confirmed to be chimeric by their clear orange fluorescence and immunostaining by anti-huKO antibody. Of 22 (40.7%) fetuses obtained after transfer of 54 blastocysts derived from 4- to 8-cell host embryos to 2 recipients, 3 (13.6%) were chimeric. Contribution of the donor cells in the tissues of the chimeric fetuses measured by image analysis software (ImageJ, NIH, Bethesda, MD, USA) ranged between 16.1 and 65.2%. These results demonstrate that the aggregation method using parthenogenetic host embryos is an efficient means to produce chimeric pig fetuses, and thereby feasible for verification of pluripotent cells such as iPS cells. Table 1.In vitro development of injected or aggregated porcine embryos

326 GENERATION OF A DOUBLE-TRANSGENIC PIG WITH PANCREAS-SPECIFIC GREEN AND LIVER-SPECIFIC RED FLUORESCENCE

Transgenic (Tg) pigs with organ/tissue-specific fluorescence expression provide invaluable research tools for many types of studies, such as organogenesis analysis, in vitro tissue generation from pluripotent cells, and progenitor/stem cell transplantation therapy. We aimed to develop a Tg pig characterised by pancreas- and liver-specific fluorescence expression. A 8.4 kb transgene construct expressing Venus (green fluorescence) under the control of the mouse Pdx1 (pancreatic duodenal homeobox-1) promoter and a BAC-derived construct (170 kb) consisting of the whole-length porcine albumin (Alb) promoter and humanized Kusabira-Orange (huKO, red fluorescence) was introduced into porcine in vitro-matured oocytes using the intracytoplasmic sperm injection (ICSI)-mediated gene transfer method. Injected embryos were transferred to the oviducts of oestrus-synchronized recipients after culture for 1 to 3 days. The transfer of 370 Pdx1-Venus embryos into 4 recipients produce 22 (5.9%) fetuses/piglets, and 9 (40.9%) Tg pigs exhibited pancreas-specific Venus expression. Two (1 male and 1 female) founder Pdx1-Venus-Tg pigs were mated with wild-type (WT) pigs and produced 32 offspring in 3 litters, of which 16 (50.0%) were transgenic. Pancreas-specific Venus expression was inherited in these Tg offspring. The transfer of 523 Alb-huKO embryos into 4 recipients resulted in 19 (3.6%) piglets including a Tg female, which showed liver-specific huKO fluorescent expression. Expression of huKO was detected by RT-PCR exclusively in liver, but not in 7 other organs/tissues examined, including heart, lung, stomach, small intestine, spleen, kidney and skin. This founder Tg female produced a total of 12 non-Tg and 5 Tg offspring (in 2 litters) after mating with a WT boar. Liver-specific huKO expression was inherited in these Tg offspring. Furthermore, the mating of a female Pdx1-Venus pig with an Alb-huKO boar yielded 7 non-Tg and 10 Tg pigs. Four of these Tg pigs carrying both of the transgenes exhibited both pancreas-specific Venus and liver-specific huKO expression in single individuals. Double-Tg pigs with pancreas-specific green fluorescence and liver-specific red fluorescence grew normally, and tests of their reproduction ability are currently underway. These data demonstrate that transgene introduction by ICSI-mediated gene transfer into in vitro-matured oocytes is a feasible option for generating pigs expressing fluorescent proteins in a tissue-specific manner.

Single pancreatic beta cells co-express multiple islet hormone genes in mice

AIMS/HYPOTHESIS

It is widely accepted that production of insulin, glucagon, somatostatin and pancreatic polypeptide in islet cells is specific to beta, alpha, delta and pancreatic polypeptide cells, respectively. We examined whether beta cells express other genes encoding islet hormones.

METHODS

Nested RT-PCR was performed on single beta cells of transgenic mice with green fluorescent protein (GFP) driven by mouse insulin I promoter (MIP-GFP).

RESULTS

Only 55% of adult beta cells expressed the insulin gene alone, while others expressed two or more islet hormone genes; 4% expressed all four hormone genes. In embryonic and neonatal cells, 60% to 80% of GFP(+) cells co-expressed pancreatic polypeptide and insulin genes in contrast to 29% in adult. To clarify cell fate, we conducted lineage tracing using rat insulin II promoter-cre mice crossed with reporter mice Gt(ROSA)26Sor-loxP-flanked STOP-cassette-GFP. All GFP(+) cells expressed insulin I and II genes, and showed similar heterogeneity of co-expression to that seen in MIP-GFP mice. Although we report expression of other hormone genes in a significant proportion of beta cells, our lineage tracing results demonstrate that after inducing InsII (also known as Ins2) expression, beta cell progenitors do not redifferentiate to non-beta cells.

CONCLUSIONS/INTERPRETATION

This study shows co-expression of multiple hormone genes in beta cells of adult mice as well as in embryos and neonates. This finding could: (1) represent residual expression from beta cell precursors; (2) result from alternative developmental pathways for beta cells; or (3) denote the differentiation potential of these cells. It may be linked to functional heterogeneity. This heterogeneity in gene expression may provide a means to characterise the functional, cellular and developmental heterogeneity seen in beta cells.

Colonisation on the tongue surface by respiratory pathogens in residents of a nursing home--a pilot study

OBJECTIVE

The morbidity and mortality of the dependent elderly that result from aspiration pneumonia have been recognised as a major geriatric health problem. The tongue has an extremely large surface area and due to its papillary structure can retain considerable quantities of food, and thus can support and harbour a large bacterial population. The purpose of this study was to gain more information on the microflora of the tongue surface and to assess the existence of oral infectious pathogens potentially causing respiratory disease in nursing home residents.

SUBJECTS AND METHODS

The tongue bacterial flora of 69 nursing home residents were examined to identify microorganisms by the culture method.

RESULTS

Thirteen species of microorganisms were detected from the tongue in this study. In 41 of 69 subjects (59%), potential respiratory pathogens, had colonised the tongue surface.

CONCLUSION

The results of the present study revealed that bacteria that commonly cause respiratory infection colonised the tongue of nursing home residents, suggesting that it may function as a reservoir of potential respiratory pathogens to facilitate colonisation on the oropharynx.

Evaluation of Thermoreversible Gelation Polymer for Regeneration of Focal Liver Injury

Liver injuries are often associated with complications including infection of the dead space, bleeding, leakage of bile and so on. We have recently developed a thermoreversible gelation polymer (TGP) which provides a good healing environment for wounds and possibly reduces complications. The purpose of this study was to evaluate whether adequate regeneration occurred with a liver defect by using TGP. The sol-gel transition of TGP is reversibly controlled by temperature; TGP is soluble below a lower critical solution temperature (LCST) of 22 degrees C, and becomes solid above the LCST. Soluble TGP can reach anywhere, and gelation of TGP occurs at the wound surface by body temperature to fill the wound/cavity. A section of median part of the left lobe comprising 3% (2 x 2 cm wide and 1 cm deep) of the liver was resected, and the Beagle dogs were assigned to three groups: 'resection alone group', 'resection + fibrin glue (FG) group' and 'resection + TGP group'. The resection alone group and the resection + FG group showed severe fibrosis at week 12, and a scarring was clearly visible. The resection + TGP group showed almost complete healing by week 4, with no adhesion and recession of the wound; the resection site was completely filled with TGP, liver-like capsule organoids emerged to cover the wound and neovascularization was observed within the organoids. Furthermore, the resected liver regenerated completely by week 12, TGP was replaced by hepatocytes, and the presence of hepatic lobules confirmed structural reorganization. The number of RCA-1-positive macrophages accumulating around the wound was significantly reduced in the resection + TGP group compared to the other two groups. In the early stage of liver resection and regeneration, TGP seemed to suppress the accumulation of macrophages and stellate cells. In the late stage, when massive inflammatory cell accumulation had subsided, TGP was degraded, that may contribute to avoid unnecessary inhibition of the liver regeneration process. Collectively, TGP may induce efficient regeneration by reducing the fibrosis and enhancing proliferation, even with a minor liver defect. Because TGP has good biocompatibility, it may become useful as an ideal biomaterial for the treatment of liver injuries.

Relationship of the fistulas to the rectum and genitourinary tract in mouse fetuses with high anorectal malformations induced by all-trans retinoic acid

Since high anorectal malformations with fistulae in human embryos and fetuses of successive developmental stages have not been reported, the embryologic relationship between the rectal fistula (RF) and the genitourinary tract (GUT) in high anorectal agenesis (ARA) remains to be elucidated. This study investigates the developmental relationship between the RF and the GUT in male and female fetuses with high ARA using our established model for high ARA with fistula in mice. Pregnant mice received all-trans retinoic acid suspended in corn oil (5 mg/ml) 100 mg/kg i.p. on day 9 of pregnancy. All fetuses were removed from the uterus on a single day from days 12 to 18 of pregnancy. The caudal regions were analyzed histologically with hematoxylin and eosin staining. All fetuses examined had high ARA with fistula. On day 12 of pregnancy, an anomalous communication was seen between the urogenital sinus (UGS) and the rectum. In the affected female fetuses, on day 14 of pregnancy the paramesonephric (müllerian) ducts and müllerian tubercle were located above the rectocloacal fistula (RCF), and on day 18 of pregnancy the uterovaginal canal was located between the cloaca and the RCF. In the male fetuses, on day 14 of pregnancy the junction between the mesonephric (wolffian) duct and the UGS was located away from the junction between the rectum and the UGS. On day 18 of pregnancy the ejaculatory duct was located between the urinary bladder and the rectourethral fistula. The results of our experiment clearly show the embryologic relationship between the RF and the GUT with high ARA. The anomalous communication between the UGS and the rectum may interfere with normal caudal migration along the dorsal wall of the UGS at the junction between the UGS and the mesonephric or paramesonephric duct.

Late infantile Hirschsprung disease-mental retardation syndrome with a 3-bp deletion in ZFHX1B

A 48-year-old woman with late infantile onset mental retardation developed megacolon. Although the patient had no typical clinical features of Hirschsprung disease-mental retardation syndrome, a new 3-base pair deletion, eliminating an Asn, was identified in the responsible gene ZFHX1B. This suggests that screening for ZFHX1B mutations is warranted even in the absence of typical clinical features of the syndrome.

Attitudes to oral care among caregivers in Japanese nursing homes

OBJECTIVES

The purpose of this study is to investigate oral care practice and awareness of it among caregivers in Japanese nursing homes.

METHODS

Caregivers were surveyed by means of a self-administered questionnaire designed to elicit the following information: awareness of oral care, its importance, the burden involved in oral care, and systematization of oral care.

RESULTS

The results showed that most caregivers are adequately informed of the importance of oral care, but are inadequately educated in oral care and have little training in systematic oral care.

CONCLUSION

The importance of providing appropriate and systematic oral care training must be stressed among caregivers along with the need to develop equipment to simplify and support oral care.

Mutations in SIP1, encoding Smad interacting protein-1, cause a form of Hirschsprung disease

Hirschsprung disease (HSCR) is sometimes associated with a set of characteristics including mental retardation, microcephaly, and distinct facial features, but the gene mutated in this condition has not yet been identified. Here we report that mutations in SIP1, encoding Smad interacting protein-1, cause disease in a series of cases. SIP1 is located in the deleted segment at 2q22 from a patient with a de novo t(2;13)(q22;q22) translocation. SIP1 seems to have crucial roles in normal embryonic neural and neural crest development.

Extracorporeal membrane oxygenation for newborns with gastric rupture

Extracorporeal membrane oxygenation (ECMO) has been recognized to be beneficial to overcome not only persistent pulmonary hypertension of the newborn, but also cardiopulmonary distress due to neonatal sepsis. However, few papers have reported on the efficacy of ECMO for surgical sepsis in neonates with underlying diseases. This paper reports our experience with ECMO in three newborns with gastric rupture, one of the most serious causes of surgical sepsis in the neonatal period. Over the past 12 years, 14 newborns had gastric rupture; 3 developed lethal cardiopulmonary distress that conservative strategies, including aggressive intensive care, failed to manage, and were selected for ECMO. The clinical data of these patients were retrospectively analyzed. The onset time and duration of ECMO varied from 23 to 143 h of age and 72 to 294 h, respectively. In case 3, complicated by massive intra-abdominal hemorrhage during ECMO, anticoagulants were changed from heparin alone to combined use with nafamostat mesilate, a thrombin inhibitor with a very short half-life. Ultrafiltration or hemodialysis was added in two cases to regulate massive volume overload associated with renal failure. Despite major hemorrhagic complications in two cases, all patients survived. Thus, ECMO may be beneficial in managing neonates with therapy-resistant gastric rupture.

Lordosis of lumbar vertebrae in omphalocele: an important factor in regulating abdominal cavity capacity

PURPOSE

Although it is well known that the tiny abdominal cavity associated with larger omphalocele enlarges rapidly after surgery, the responsible mechanism remains obscure. The authors have studied the curve of lumbar vertebrae and established a hypothesis in which lordosis of lumbar vertebrae plays a major role in changing the capacity of the abdominal cavity.

METHODS

Fifty-three patients with intact omphalocele and 10 normal newborns as the control were studied. The size of omphalocele was determined from the mean value of the length and breadth of the sac. The curve of lumbar vertebrae (lordotic angle) was measured using Cobb's technique on the lateral radiograph serially taken in the supine position.

RESULTS

The mean lordotic angle of 53 patients was 22.2 degrees (range, 0 to 65), which was significantly greater than 11.0 degrees of the control (P <.012). The individual lordotic angle before surgery was significantly correlated with the size of omphalocele (r = 0.668, P <.0001). In serial studies carried out in 15 patients with larger omphalocele, the mean lordotic angle was decreased significantly from 30.5 degrees to 20.0 degrees (P <.009) on the first postoperative day and returned to the control level within a few weeks.

CONCLUSIONS

These results suggest that severe lumbar lordosis may well become an alternative factor to produce visceroabdominal disproportion observed before surgery, and its correction after surgery may well induce the abdominal cavity to rapidly enlarge. It may be speculated that the dehiscence of abdominal rectus muscles associated with omphalocele causes the tension of ventral muscles to decline, and, then, imbalance in tension between ventral (abdominal) and dorsal (back) muscles causes the lumbar lordosis to increase. Accordingly, at the staged procedure, the prosthetic sheet should be attached under moderate tension, and its plication should be carried out at regular intervals to maintain the tension of abdominal rectus muscles.

Effect of swallowing training on swallowing disorders in Parkinson's disease

The purpose of the present study was to determine whether swallowing training improves swallowing function in patients with Parkinson's disease. Ten patients (5 males, 5 females) who had symptoms of dysphagia and 12 healthy volunteers were studied. The initiation time of the swallowing reflex, the "premotor time" (PMT), was calculated from an electromyogram of the submental muscles before and after swallowing training. Patients with Parkinson's disease had a significantly longer PMT (p = 0.0014) than did healthy controls. There was no correlation between PMT and the duration of the disease (r = -0.146; p = 0.6867) or the patient's age (r = 0.602; p = 0.0653). After swallowing training, the patients' PMTs decreased significantly (p = 0.0051).

Late versus early surgical correction for congenital diaphragmatic hernia in newborn infants

BACKGROUND

Congenital diaphragmatic hernia, although rare (1 per 2-4,000 births), is associated with high mortality and cost. Opinion regarding the timing of surgical repair has gradually shifted from emergent repair to a policy of stabilization using a variety of ventilatory strategies prior to operation. Whether delayed surgery is beneficial remains controversial.

OBJECTIVES

To summarize the available data regarding whether surgical repair in the first 24 hours after birth rather than later than 24 hours of age improves survival to hospital discharge in infants with congenital diaphragmatic hernia who are symptomatic at or immediately after birth.

SEARCH STRATEGY

Search of Medline (1966-1999), Embase (1978-1999) and the Cochrane databases using the terms "congenital diaphragmatic hernia" and "surg*"; citations search, and contact with experts in the field to locate other published and unpublished studies.

SELECTION CRITERIA

Studies were eligible for inclusion if they were randomized or quasi-randomized trials that addressed infants with CDH who were symptomatic at or shortly after birth, comparing early (<24 hours) vs late (>24 hours) surgical intervention, and evaluated mortality as the primary outcome.

DATA COLLECTION AND ANALYSIS

Data were collected regarding study methods and outcomes including mortality, need for ECMO and duration of ventilation, both from the study reports and from personal communication with investigators. Analysis was performed in accordance with the standards of the Cochrane Neonatal Review Group.

MAIN RESULTS

Two trials met the pre-specified inclusion criteria for this review. Both were small trials (total n<90) and neither showed any significant difference between groups in mortality. Meta-analysis was not performed because of significant clinical heterogeneity between the trials.

REVIEWER'S CONCLUSIONS

There is no clear support for either immediate (within 24 hours of birth) or delayed (until stabilized) repair of congenital diaphragmatic hernia, but a substantial advantage to either one cannot be ruled out. A large, multicenter randomized trial would be needed to answer this question.

Selective expression of the large neutral amino acid transporter at the blood-brain barrier

Amino acid supply in brain is regulated by the activity of the large neutral amino acid transporter (LAT) at the brain capillary endothelial cell, which forms the blood-brain barrier (BBB) in vivo. Bovine BBB poly(A)(+) RNA was isolated from 2.0 kg of fresh bovine brain and size fractionated on a sucrose density gradient, and a size-fractionated bovine BBB cDNA library in the pSPORT vector was prepared. The full-length cDNA encoding the bovine BBB LAT was isolated from this library, and the predicted amino acid sequence was 89-92% identical to the LAT1 isoform. The bovine BBB LAT1 mRNA produced a 10-fold enhancement in tryptophan transport into frog oocytes coinjected with bovine BBB LAT1 mRNA and the mRNA for 4F2hc, which encodes the heavy chain of the heterodimer. Tryptophan transport into the mRNA-injected oocytes was sodium independent and was specifically inhibited by other large neutral amino acids, and the K(m) of tryptophan transport was 31.5 +/- 5.5 microM. Northern blotting with the bovine BBB LAT1 cDNA showed that the LAT1 mRNA is 100-fold higher in isolated bovine brain capillaries compared with C6 rat glioma cells or rat brain, and the LAT1 mRNA was not detected in rat liver, heart, lung, or kidney. These studies show that the LAT1 transcript is selectively expressed at the BBB compared with other tissues, and the abundance of the LAT1 mRNA at the BBB is manyfold higher than that of transcripts such as the 4F2hc antigen, actin, or the Glut1 glucose transporter.

Secondary excision of choledochal cysts after previous cyst-enterostomies

BACKGROUND/AIMS

Patients with a choledochal cyst previously treated by internal drainage should undergo secondary cyst excision. The results of such secondary excisions have not yet been reported.

METHODOLOGY

Over a 27-year period, 121 patients underwent excision of a choledochal cyst at our hospitals. Of these, 14 patients underwent secondary cyst excision following internal drainage. These patients were compared retrospectively with the remaining 107 patients who underwent primary cyst excision.

RESULTS

Blood loss and operative time were greater, and early and late post-operative complications were significantly more frequent in the secondary excision group. Wound infection (early complication), pancreatic stones (late complication), and hepatolithiasis (late complication) were significantly more common in the secondary excision group. Histologically, inflammation and biliary glands were more frequently seen in the resected bile ducts in the secondary excision group.

CONCLUSIONS

The long-term results of secondary excision of choledochal cysts are worse than after primary excision. The frequent late complications may be related to the development of biliary glands as a consequence of cyst-enterostomy.

A novel nonsense mutation of the PEX7 gene in a patient with rhizomelic chondrodysplasia punctata

Mutations in the PEX7 gene encoding a peroxisome targeting signal 2 (PTS2) were identified in two patients with rhizomelic chondrodysplasia punctata (RCDP). A 7-year-old girl, the first Japanese individual to be diagnosed biochemically as a case of RCDP, had a novel nonsense mutation, R232ter, in the PEX7 gene, which had been inherited from her consanguineous parents. Another patient, a Chilean boy with RCDP, had compound heterozygous mutations of PEX7, L292ter and A218V, both of which have been documented. R232ter, which deletes all of the last two WP40 repeats in the PEX7 gene, is sufficient to inactivate functions of the PEX7 gene.

Comparison of venoarterial versus venovenous access in the cerebral circulation of newborns undergoing extracorporeal membrane oxygenation

This study was designed to compare venoarterial (VA) with venovenous (VV) access in the cerebral circulation of newborn infants during extracorporeal membrane oxygenation (ECMO). Among 14 infants with VA ECMO, 7 had no intracranial complications (group 1), while the others (group 2) developed intracranial hemorrhage (ICH). In contrast, among 19 infants with VV ECMO, only 1 developed ICH. Serial echocardiograms were performed before and after 1, 6, 12, and 24 h and 2 and 3 days of ECMO. The mean cerebral blood flow (CBF) velocities were measured in the anterior cerebral artery (ACA), right and left internal carotid arteries (Rt, Lt-ICA), basilar artery (BA), and right and left middle cerebral arteries (Rt, Lt-MCA). Ejection fraction (EF), cardiac output (CO), and stroke volume (SV) were also measured using standard echography. The velocity levels in the ACA, Rt-MCA, and Lt-MCA in VA ECMO were lower than those in VV ECMO, while those in the Lt-ICA and BA in VA ECMO were higher than those in VV ECMO. The EF, CO, and SV were lower in cases of VA ECMO than in VV ECMO. In cases of VA ECMO, there were no differences between groups 1 and 2 in velocities in the ACA, Rt-ICA, or Lt-ICA. However the velocities in group 2 in the BA, Rt-MCA, and Lt-MCA were lower than those in group 1 before and during ECMO. Similarly, the EF, CO, and SV were lower in group 2 (12.0%-31.0%, 0. 10-0.32 l/min, and 0.66-1.55 ml, respectively) than in group 1 (29. 5%-49.3%, 0.25-0.63 l/min, and 2.15-3.85 ml) during ECMO. However, in the infants on VV ECMO the CBF was either maintained or gradually increased before and during ECMO. Their cardiac parameters were: EF 46.1%-53.0%, CO 0.43-0.52 l/min, and SV 2.72-3.84 ml during ECMO. It is concluded that in VA ECMO CBF velocities, particularly in infants who developed ICH, decreased after the onset of ECMO in association with poor cardiac function, while in VV ECMO they were stable, probably due to normal systemic hemodynamics and cardiac function.

[Present situation and future subjects of N.SAS study--based on experience of managing data center]

The "National Surgical Adjuvant Study" (N-SAS) was established as a study group on carcinostatics on the market as part of the Ministry of Health and Welfare's 1995/1996 consignment project. Patient registration started in October 1996, and later it was restructured as a consignment study by Taiho Pharmaceutical Co., Ltd. in April 1997. It still continues to date. EPS Co., Ltd. has operated the "N.SAS Data Center" to conduct three clinical trials of N.SAS study. In the following, we analyse the current situation and subjects of N.SAS study from the viewpoint of the data center, recognising the necessity of infrastructure at medical institutions while complying with enforcement of newly GCP and GPMSP. First, the organization and function of N.SAS, and the role and position of data center on N.SAS study, are explained. Some notes are introduced from conducting In-house Monitoring on N.SAS, especially methods and formation of communicating information between N.SAS Data Center and institutions. We also propose an infrastructure which will be essential for smooth promotion of long-term and large-scale trials like the N.SAS study.

Analysis of patients with congenital diaphragmatic hernia requiring pre-operative extracorporeal membrane oxygenation (ECMO)

The purpose of this report was to analyze the patients requiring preoperative extracorporeal membrane oxygenation (ECMO) as the most critical group of patients with congenital diaphragmatic hernia (CDH) and to identify any special features. Over the past 11 years, out of 72 neonates with CDH admitted before 24 h of age, 40 (56%) could be managed with conventional therapies while the other 32 (44%) required ECMO. Seventeen infants requiring preoperative ECMO were classified as group 1, and the 15 with postoperative ECMO as group 2 (controls). The records of patients in both groups were analyzed. Patients in group 1 were not only severely hypoxic, but also significantly hypercapneic on admission, and in 14 (82%) the diaphragmatic defect was so large or totally agenetic that a prosthetic patch was necessary. The average age at onset of ECMO in group 1 was 13.1 h, and the average duration was 159 h. Major hemorrhagic complications including intracranial hemorrhage occurred with a significantly higher frequency in group 1. The survival rate in group 1 was 41%, compared with 73% in group 2 and 85% in non-ECMO patients. Four infants in group 1 with extremely hypoplastic lungs could not be weaned from ECMO, and died without undergoing an operation. Moreover, 4 of the 7 survivors in group 1 required prolonged (105-658 days) ventilator care with a tracheostomy after weaning from ECMO, and were frequently hospitalized thereafter. The pulmonary function of these patients remained severely underdeveloped for a long time; indeed, the average pulmonary perfusion ratio of the affected side remained at only 40% of the contralateral side in group 1, although the volume ratio reached 85%. These findings may suggest that the main pathology of the patients requiring preoperative ECMO was a high degree of pulmonary hypoplasia, and that there will be limitations to management using ECMO.

Venovenous extracorporeal membrane oxygenation in newborn infants using the umbilical vein as a reinfusion route

PURPOSE

The authors report on four neonates treated with venovenous (VV) extracorporeal membrane oxygenation (ECMO) using the umbilical vein as a reinfusion route.

METHODS

From 1994 to 1997, 26 instances VV-ECMO in neonates have been carried out at our neonatal center for the treatment of severe respiratory and cardiac failure. Among them, 22 patients could be treated with VV-ECMO mainly using 15F double-lumen catheter (DLC), adding the cephalic drainage using another catheter. In the remaining four cases, however, attempts to insert the DLC into the right internal jugular vein failed because the vein was too small or technical problems. For such instances, two catheters were cannulated into the right atrium and the cephalic portion of the right internal jugular vein, respectively. These two venous catheters were connected to the drainage route of ECMO circuit with a "Y" connector. Then, the umbilical vein was cannulated with 10F or 8F catheter, which was connected to the reinfusion route of ECMO to return the oxygenated blood to the infant.

RESULTS

The median age at which ECMO was initiated was 18 hours, and the median ECMO course was 72 hours. The liver function tests were slightly and transiently worsened in two patients during VV perfusion, (in one patient serum glutamic-oxaloacetic transaminase [SGOT] elevated to 76 IU/L and serum glutamic-pyruvic transaminase [SGPT] to 49 IU/L, and in another patient SGOT elevated to 56 IU/L and SGPT remained in normal range). Preumbilical cannula pressures were measured in two patients. In a patient who used 10F umbilical cannula, the preumbilical maximum pressure was 43 mm Hg at 250 mL/min of ECMO flow. In another with an 8F catheter, it was 72 mm Hg at 180 mL/min of ECMO flow. All of the patients survived without any neurological complications.

CONCLUSIONS

If the right internal jugular vein would not accommodate the DLC, VV-ECMO using the umbilical vein as a infusion route could be selected.