Stage III Chorioamnionitis Is Associated with Reduced Risk of Severe Retinopathy of Prematurity

OBJECTIVE

To identify whether histologically confirmed chorioamnionitis (hCAM) is associated with development of retinopathy of prematurity (ROP).

STUDY DESIGN

We retrospectively analyzed two different cohorts. Cohort 1 was the national database of newborns in Japan born at ≤1500g or <32 weeks' gestation (January 2003 through April 2021, n=38,013). Cohort 2 was babies born at <1500g from a single institution in Tsuchiura, Japan, (April 2015 through March 2018, n=118).

RESULTS

For Cohort1, after adjusting for potential confounders, stage III CAM (n=5,554) was associated with lower odds of severe ROP (stage ≥3 or required peripheral retinal ablation) by 14% (odds ratio [OR]: 0.86; 95% confidence interval [CI]: 0.78-0.94]. CAM of stage I (n=3,277) and II (N=4,319) was not associated with the risk of ROP. For Cohort 2, the odds of severe ROP were significantly reduced in moderate to severe hCAM groups (stage II, OR: 0.06, 95% CI: 0.05-0.82; stage III, OR: 0.10, 95% CI: 0.01-0.84). Neonates with funisitis, comorbidity of hCAM, and a finding of fetal inflammatory response had lower odds of severe ROP (OR: 0.11; 95% CI: 0.01-0.93).

CONCLUSIONS

After adjusting for confounders, severe hCAM with fetal inflammatory response was associated with reduced risk of ROP.

Comparison of High-Frequency Oscillatory Ventilators

BACKGROUND

The performance of high-frequency oscillatory ventilators (HFOV) differs by the waveform generation mode and circuit characteristics. Few studies have described the performance of piston-type HFOV. The present study aimed to compare the amplitude required to reach the target high-frequency tidal volume ([Formula: see text]); determine the relationship between the settings and actual pressure in amplitude or mean airway pressure ([Formula: see text]); and describe the interaction among compliance, frequency, and endotracheal tube (ETT) inner diameter in 4 HFOV models, including Humming X, Vue (a piston type ventilator commonly used in Japan), VN500 (a diaphragm type), and SLE5000 (a reverse jet type).

METHODS

The oscillatory ventilators were evaluated by using a 50-mL test lung with 0.5 and 1.0 mL/cm H2O compliance, [Formula: see text] of 10 cm H2O, frequency of 12 and 15 Hz, and ETT inner diameters 2.0, 2.5, and 3.5 mm. At each permutation of compliance, frequency, and ETT, the target high-frequency [Formula: see text] was increased from 0.5 to 3.0 mL. The change in [Formula: see text] from the ventilator (ventilator [Formula: see text]) to Y-piece (Y [Formula: see text]) and alveolar pressure (alveolar [Formula: see text]) and the change in amplitude from the ventilator (ventilator amplitude) to Y-piece (Y amplitude) and alveolar pressure (alveolar amplitude) were determined at high-frequency [Formula: see text] of 1.0 and 3.0 mL.

RESULTS

To achieve the target high-frequency [Formula: see text], the Humming X and Vue required a higher amplitude than did the SLE5000, but the maximum amplitude in the VN500 was unable to attain a larger high-frequency [Formula: see text]. Ventilator [Formula: see text] and alveolar pressure decreased at the Y-piece with the Humming X and Vue but increased with the SLE5000. The ventilator [Formula: see text] in the VN500 decreased remarkably at a frequency of 15 Hz. The ventilator amplitude in all 4 ventilators decreased while temporarily increasing at the Y-piece in the VN500.

CONCLUSIONS

The actual measured value, such as alveolar [Formula: see text] and high-frequency [Formula: see text], varied according to the type of HFOV system and the inner diameter of the ETT, even with identical settings. Clinicians should therefore determine the setting appropriate to each HFOV model.

Impact of amino acid 233 in Tax on bovine leukemia virus infection in Japanese Black cattle

Bovine leukemia virus (BLV) is an economically important pathogen that both causes fatal enzootic bovine leukosis (EBL) and reduces lifetime milk production, reproductive efficiency, carcass weight, and longevity in dairy cows. The virus can be divided into two categories based on the amino acid at position 233 in Tax protein, which activates viral transcription and probably plays crucial roles in leukemogenesis. We recently reported that early-onset EBL in Japanese Black (JB) cattle was frequently caused by L233-Tax-carrying virus. This study examined the impact of BLV infection, the proviral load (PVL), and amino acid 233 in Tax on the outcomes of JB cattle. We measured PVL in cattle enrolled between February 2016 and December 2018, determined the Tax type of the isolates, and performed follow-up until March 2022. The results demonstrated that BLV infection increased the risk of involuntary culling and mortality in JB cattle in a PVL-dependent manner. Infection with L233-Tax-carrying virus increased the likelihood of mortality by 1.6-fold compared with the effects of P233-Tax-carrying virus infection. Intrauterine and perinatal infections were frequently caused by L233-Tax-carrying virus, and these infections were likely to influence the early onset of EBL in JB cattle. Conversely, breeding cows infected with P233-Tax-carrying virus were often eliminated by involuntary culling. These findings indicate that amino acid 233 in Tax has importance in terms of preventing economic loss attributable to EBL in JB cattle.

Neonatal asphyxia as an inflammatory disease: Reactive oxygen species and cytokines

Neonatologists resuscitate asphyxiated neonates by every available means, including positive ventilation, oxygen therapy, and drugs. Asphyxiated neonates sometimes present symptoms that mimic those of inflammation, such as fever and edema. The main pathophysiology of the asphyxia is inflammation caused by hypoxic-ischemic reperfusion. At birth or in the perinatal period, neonates may suffer several, hypoxic insults, which can activate inflammatory cells and inflammatory mediator production leading to the release of larger quantities of reactive oxygen species (ROS). This in turn triggers the production of oxygen stress-induced high mobility group box-1 (HMGB-1), an endogenous damage-associated molecular patterns (DAMPs) protein bound to toll-like receptor (TLR) -4, which activates nuclear factor-kappa B (NF-κB), resulting in the production of excess inflammatory mediators. ROS and inflammatory mediators are produced not only in activated inflammatory cells but also in non-immune cells, such as endothelial cells. Hypothermia inhibits pro-inflammatory mediators. A combination therapy of hypothermia and medications, such as erythropoietin and melatonin, is attracting attention now. These medications have both anti-oxidant and anti-inflammatory effects. As the inflammatory response and oxidative stress play a critical role in the pathophysiology of neonatal asphyxia, these drugs may contribute to improving patient outcomes.

Effects of ultra-pure soft water on the hands of nurses in a neonatal intensive care unit: A randomized crossover study

BACKGROUND

Healthcare workers (HCWs) wash their hands with tap water (TW) and soap. However, hard TW causes dermatitis.

OBJECTIVES

The present study aimed to compare the effects of ultra-pure soft water (UPSW) with those of TW on the hands of HWCs.

METHODS

The present study was a prospective randomized trial with a crossover design. All the nurses in the neonatal intensive care unit (NICU) at the study centre were divided into Sequence 1 (UPSW to TW) or 2 (TW to UPSW) and washed their hands with TW or UPSW in alternating 4-week periods with a 4-week washout period. Trans-epidermal water loss (TEWL) and stratum corneum hydration (SCH) were evaluated. Skin condition was self-assessed.

RESULTS

Twenty-one and 22 nurses were assigned to Sequence 1 and Sequence 2, respectively. USPW increased SCH to a significantly greater degree than TW (mean: 26.3 μS ± 12.3 SD; 95% confidence interval: 1.12-51.54; p = 0.041) although it did not affect TEWL. UPSW use significantly improved the subjects' skin condition, as reflected in an overall increase in the assessment scores.

CONCLUSIONS

UPSW improved SCH and the condition of hand skin. Prolonged USPW use may increase nurses' comfort during work and hand hygiene compliance.

Effect of the duration of previous osteoporosis treatment on the effect of romosozumab treatment

The effect of romosozumab is affected by previous osteoporosis treatment. Here we showed that the duration of the previous treatment just before romosozumab affects the therapeutic effect of romosozumab. Using denosumab and oral bisphosphonates for more than 1 year attenuates the effect of romosozumab.

INTRODUCTION

As an anti-sclerostin antibody, romosozumab suppresses bone resorption and stimulates bone formation. We investigated whether the effectiveness of 12 months of romosozumab treatment depended on the duration of previous treatment with teriparatide, denosumab, or oral bisphosphonates.

METHODS

In total, 259 osteoporosis patients received subcutaneous injections of romosozumab (210 mg) every 4 weeks during 2019 and 2020. This study was designed as a pre-post comparison. The end points were the percent changes of bone mineral density (BMD) after 12 months of romosozumab treatment. The patients were divided into seven groups depending on the type and duration of previous treatment before starting romosozumab as follows: non-previous treatment group, change from teriparatide used for 1 year or less/more than 1 year, change from denosumab used for 1 year or less/more than 1 year, and change from oral bisphosphonates used for 1 year or less/more than 1 year.

RESULTS

The effects of previous treatment with teriparatide on the effectiveness of 12-month romosozumab did not clearly depend on the duration of treatment (p > 0.05). In contrast, the effects of previous treatments with denosumab or oral bisphosphonates on the effectiveness of 12-month romosozumab depended on the previous treatment duration, which was reflected by the differences in percent change of the spine BMD (both p < 0.05), however, there were no significant differences in the percent change of the total hip BMD (both p > 0.05).

CONCLUSION

The duration of the previous treatment affected the effectiveness of romosozumab. Using denosumab and oral bisphosphonate for more than 1 year attenuated the effect of romosozumab.

Transcriptome analysis of umbilical cord mesenchymal stem cells revealed fetal programming due to chorioamnionitis

Although chorioamnionitis (CAM) has been demonstrated to be associated with numerous short- and long-term morbidities, the precise mechanisms remain unclear. One of the reasons for this is the lack of appropriate models for analyzing the relationship between the fetal environment and chorioamnionitis and fetal programming in humans. In this study, we aimed to clarify the fetal programming caused by CAM using the gene expression profiles of UCMSCs. From nine preterm neonates with CAM (n = 4) or without CAM (n = 5), we established UCMSCs. The gene expression profiles obtained by RNA-seq analysis revealed distinctive changes in the CAM group USMSCs. The UCMSCs in the CAM group had a myofibroblast-like phenotype with significantly increased expression levels of myofibroblast-related genes, including α-smooth muscle actin (p < 0.05). In the pathway analysis, the genes involved in DNA replication and G1 to S cell cycle control were remarkably decreased, suggesting that cellular proliferation was impaired, as confirmed by the cellular proliferation assay (p < 0.01–0.05). Pathway analysis revealed that genes related to white fat cell differentiation were significantly increased. Our results could explain the long-term outcomes of patients who were exposed to CAM and revealed that UCMSCs could be an in vitro model of fetal programming affected by CAM.

Assessment of the middle mesial canals of mandibular first molars using cone-beam computed tomography: an in vivo study

OBJECTIVE

For a successful root canal therapy, it is necessary to locate all the canals debride and seal them with an inert filling material. The clinician must be aware of the internal morphology and variations in a permanent tooth. Mandibular first molars are widely studied to identify variations in the anatomy of the pulp space. In this study, the primary objective was to measure the distance between the mesiobuccal (MB) and mesiolingual (ML) canals in patients with and without a middle mesial canal (MMC) using cone-beam computed tomography (CBCT). The secondary objectives were to assess the tapering degree of the mesial root and to measure the dentinal thickness in relation to the danger-zone area in patients with and without an MMC.

MATERIALS AND METHODS

A total of 200 CBCT scans were evaluated for the presence of an MMC. Two observers performed the observations, and the results obtained were subject to statistical analyses.

RESULTS

The results revealed the prevalence of MMC was 5%. The average distance between the MB and ML canals was higher when there was an MMC [M(SD) = 3.61 (0.6) vs. 2.69 (0.66)]. However, there were no differences between the groups in the distance to the danger-zone area and the tapering degree of the mesial root. On CBCT images, the MMC was clearly visible 3 mm apical to the level of the cementoenamel junction; beyond 3 mm, the MMC could not be traced.

CONCLUSIONS

Based upon the results of this study, the average distance between the MB and ML canals was higher when there was an MMC. A lesser degree of taper would be preferred to prepare the MMC than to prepare the other canals. It is recommended that careful examination of the canal 3 mm apical to the cementoenamel junction should be carried out when attempting to detect an MMC.

Evaluation of the accuracy of a non-invasive hemoglobin-monitoring device in schoolchildren

BACKGROUND

Iron deficiency anemia (IDA) is a public health problem in children and adolescents that is characterized by reduced hemoglobin (Hb) levels. Non-invasive monitoring devices can measure Hb levels continuously without pain or discomfort; however, little is known about their accuracy in children and adolescents. This study estimated the accuracy of a non-invasive Hb monitor in this age group.

METHODS

Participants were outpatients visiting the Tokyo Metropolitan Children's Medical Center for blood tests between January and March 2019. Hb levels were measured using both non-invasive Astrim Fit monitoring devices and invasive blood collection followed by automated analysis. Bland-Altman analysis assessed the agreement between the two measurements.

RESULTS

Overall, 120 schoolchildren (9-15 years old, 51 % female) were enrolled. The non-invasive measuring device recorded Hb levels of 13.5 ± 1.6 g/dL (mean ± standard deviation [SD]), while the mean Hb level obtained from the collected blood was 13.7 ± 1.7 g/dL. Therefore, the mean difference of bias and SD of precision was 0.17 ± 1.95 g/dL. Values of lower and upper limits of agreement were -3.65 and 3.99, respectively. There was no systematic fixed or proportion bias. Fifty-nine participants (49 %) had a relative error of ± 0.10.

CONCLUSION

The Astrim Fit non-invasive Hb monitor can be used to evaluate Hb levels among schoolchildren for health promotion or research purposes because of its extremely low bias (or precision), no systematic biases (including fixed or proportion biases), and positive correlation between non-invasive monitoring and blood drawing. However, it is difficult to assess Hb levels in children and adolescents using the Astrim Fit device for diagnostic purposes.

Furosemide clearance in very preterm neonates early in life: A pilot study using scavenged samples

BACKGROUND

Furosemide is an off-label drug, frequently used as a diuretic in neonates with oliguria and/or edema. Its clearance in preterm neonates is lower than in term neonates or children. We aimed, herein, to clarify furosemide clearance (CL) in very preterm (VP) neonates (<28 weeks' gestation) within the first 2 weeks of life and identify the factors predictive of the pharmacokinetics (PK) parameters, such as CL.

METHODS

Furosemide was administered at 0.5 or 1 mg/kg in a 0.5-h infusion via a syringe pump; blood samples were drawn from an artery or vein after the intravenous injection. The serum furosemide concentration was measured using high-performance liquid chromatography. The PK parameters were then analyzed using Bayesian estimation.

RESULTS

Thirteen blood samples were obtained from 10 VP neonates after intravenous injection. The mean postconceptional age and mean postnatal days at exposure to furosemide were 26.9 weeks and 7.1 days, respectively. The estimated mean CL was 16.5 mL/kg/h. The mean distribution volume (Vd) and elimination half-life (t1/2) were 0.37 L/kg and 15.3 h, respectively. Furosemide CL was negatively associated with serum creatinine (SCr) [CL = 84.2 - 67.1 × SCr (mg/dL)].

CONCLUSIONS

Very preterm neonates within the first 2 weeks of life had a higher CL than subjects in other preterm neonatal studies. The SCr level was the sole parameter influencing furosemide CL and might serve as a good index for furosemide dosing in VP neonates.

Cytomegalovirus-related sepsis-like syndrome in very premature infants in Japan

BACKGROUND

Very premature infants are at high risk of developing a symptomatic postnatal cytomegalovirus (CMV) disease, such as CMV-related sepsis-like syndrome (CMV-SLS). To address the limited data regarding its clinical features, a nationwide survey of CMV-SLS was conducted.

METHODS

A questionnaire regarding CMV status and the clinical outcomes of CMV-SLS was sent to centers with reported cases of CMV-SLS.

RESULTS

Twelve CMV-SLS cases, nine confirmed and three probable cases, were reported during the 3-year survey period. The median gestational age and birthweight were 25 weeks and 547 g, respectively. At disease onset, the median age was 49 days, and the corrected age was 31 weeks. Untreated breast milk was given in four cases (33%), whereas frozen breast milk was given in nine (75%). No specific symptoms and laboratory data regarding CMV-SLS were found.

CONCLUSIONS

Very premature infants developed CMV-SLS after 1 month of age. There are no symptoms and signs specific for the diagnosis of CMV-SLS, so CMV-SLS should be considered as a differential diagnosis for premature infants who have unexplained sepsis-like symptoms during the convalescent phase.

Early clinical effects, safety, and predictors of the effects of romosozumab treatment in osteoporosis patients: one-year study

Romosozumab is an effective treatment for spine osteoporosis because it reduces the incidence of new fractures and significantly increases the percent change in the spine BMD at 12 months. The percent change in the spine BMD is higher in patients not previously treated with other anti-osteoporosis medications.

INTRODUCTION

Romosozumab appeared as a new osteoporosis medication in Japan in 2019. It is an anti-sclerostin antibody, which increases bone formation and suppresses bone resorption. The aim of our study was to elucidate the clinical effects, safety, and predictors of the effects of one-year romosozumab treatment.

METHODS

This study was an observational study designed as a pre-post study in 262 patients. Romosozumab (210 mg) was administered subcutaneously once every 4 weeks during 12 months. We focused on incidence of new fractures, safety, bone mineral density (BMD) at the spine and total hip, and bone metabolism markers.

RESULTS

There were five cases of new fractures during one-year romosozumab treatment. There were no fatal adverse events. Percent changes from baseline in the spine and total hip BMD after 12 months of romosozumab treatment were 10.67% and 2.04%, respectively. Romosozumab had better effects in cases of severe osteoporosis with low spine BMD, high TRACP-5b, and high iP1NP at the start of romosozumab treatment. The percent change in the spine BMD at 12 months was significantly lower in the group transitioning from bisphosphonates than in the group not previously treated with other anti-osteoporosis medications.

CONCLUSION

Romosozumab is an effective treatment for spine osteoporosis because it significantly increases the percent change in the spine BMD at 12 months. The percent change in the spine BMD is higher in patients not previously treated with other anti-osteoporosis medications.

Short-term outcomes in infants with mild neonatal encephalopathy: a retrospective, observational study

BACKGROUND

Neonatal encephalopathy due to acute perinatal asphyxia is a major cause of perinatal brain damage. Moderate to severe neonatal encephalopathy is associated with high mortality and morbidity rates. However, the neurodevelopmental outcomes in neonates with mild neonatal encephalopathy are unclear. The primary aim of this single-center observational study was to assess the short-term outcomes in term neonates with mild neonatal encephalopathy due to perinatal asphyxia. A secondary aim was to identify predictors of poor prognosis by identifying the characteristics of these infants according to their short-term outcomes.

METHODS

We retrospectively investigated all infants with perinatal asphyxia at Tokyo Metropolitan Children's Medical Center from January 2014 to December 2019. An abnormal short-term outcome was defined as any one of the following: seizures or abnormal electroencephalography, abnormal brain magnetic resonance imaging obtained within the first 4 weeks of life, and abnormal neurological examination findings at discharge.

RESULTS

In total, 110 term infants with perinatal asphyxia during the study period were screened and 61 were diagnosed with mild neonatal encephalopathy. Eleven (18 %) of these infants had an abnormal short-term outcome. The median Thompson score at admission was significantly higher in infants with abnormal short-term outcomes than in those with normal short-term outcomes (5 [interquartile range, 4-5.5] vs. 2 [interquartile range, 1-3], p < 0.01). Receiver operating characteristic curve analysis showed that a cutoff value of 4 had high sensitivity and specificity (90.9 and 83.0 %, respectively) for prediction of an abnormal short-term outcome.

CONCLUSIONS

18 % of infants with mild encephalopathy had an abnormal short-term outcome, such as abnormal brain magnetic resonance imaging findings. The Thompson score at admission may be a useful predictor of an abnormal short-term outcome in infants with mild neonatal encephalopathy.

Maternal mesalazine-induced neonatal gastrointestinal bleeding

Ulcerative colitis often develops in the reproductive age women and can cause exacerbation by pregnancy. Mesalazine (5-aminosalicylic acid) is recommended as a safe anti-inflammatory drug during pregnancy. However, maternal mesalazine is transferred to the fetus through the placenta and may cause allergic events. A pregnant woman with severe ulcerative colitis was treated with a dose of mesalazine 4,000 mg/day from early gestation to delivery. Immediately after birth, the preterm neonate vomited bloody contents and discharged massive gross haematochezia. Serum concentrations of mesalazine and its main metabolite were high in the mother and the umbilical cord. Faecal eosinophils and drug-induced lymphocyte stimulation test suggested possibility that sensitisation with mesalazine in utero caused allergic enterocolitis like food protein-induced allergic proctocolitis. Maternal mesalazine has a potential of fetal sensitisation and cause allergic disease.

Early clinical effects, safety, and appropriate selection of bone markers in romosozumab treatment for osteoporosis patients: a 6-month study

Our 6-month study showed the usefulness of romosozumab for preventing fractures and its safety. It was effective in patients with low baseline spine BMD, high TRACP-5b, and high iP1NP. Percent change from baseline of TRACP-5b and iP1NP after 1 month correlated with that from baseline of BMD after four to 6-month treatment.

INTRODUCTION

Romosozumab appeared as a new osteoporosis medication in Japan in 2019. It is an anti-sclerostin antibody which increases bone formation and suppresses bone resorption. In this study, we analyzed the actual clinical effects, adverse effects, and the optimal way to evaluate the treatment.

METHODS

Romosozumab was administered as subcutaneous injection of 210 mg once every 4 weeks. We conducted pre-post study in 185 patients treated for 6 months. We focused on the incidence of new vertebral fractures, safety, bone mineral density (BMD) at the spine and total hip, and bone metabolism markers. We evaluated BMD before romosozumab treatment and after 4 to 6 months and performed the serum analysis before romosozumab treatment, after 1, 3, and 6 months.

RESULTS

There was no new fracture during treatment, and there was no fatal adverse event including cardiovascular disease. Since percent changes from baseline of the spine and total hip BMD were 6.34% and 1.53% after 4- to 6-month treatment, the treatment was effective for spine osteoporosis. Tartrate-resistant acid phosphatase 5b (TRACP-5b) and intact type I procollagen N-terminal propeptide (iP1NP) had significant changes during romosozumab treatment (p < 0.05). Percent change from baseline of TRACP-5b and iP1NP after 1 month correlated with percent change from baseline of BMD after 4 to 6 months of treatment.

CONCLUSION

Romosozumab is effective in preventing fractures and useful for increasing the spine BMD. Also, romosozumab is relatively safe to use. It is especially effective in patients with low baseline spine BMD, high TRACP-5b, and high iP1NP.

Randomized Controlled Trial of High-Flow Nasal Cannula in Preterm Infants After Extubation

OBJECTIVES

Our aim is to compare the efficacy and safety of high-flow nasal cannula (HFNC) against those of nasal continuous positive airway pressure (NCPAP) or nasal intermittent positive-pressure ventilation (NIPPV) after extubation in preterm infants.

METHODS

This prospective, randomized, noninferiority trial was conducted in 6 tertiary NICUs. Infants born at <34 weeks who needed noninvasive ventilation after extubation were enrolled. We randomly assigned infants to an HFNC group when HFNC was used or to an NCPAP/NIPPV group when NCPAP or NIPPV was used. The primary outcome was treatment failure within 7 days after extubation. We then examined clinical aspects of treatment failure with HFNC use.

RESULTS

In total, 176 and 196 infants were assigned to the HFNC and NCPAP/NIPPV groups, respectively. The HFNC group showed a significantly higher rate of treatment failure than that of the NCPAP/NIPPV group, with treatment failure occurring in 54 infants (31%) compared with 31 infants (16%) in the NCPAP/NIPPV group (risk difference, 14.9 percentage points; 95% confidence interval, 6.2-23.2). Histologic chorioamnionitis (P = .02), treated patent ductus arteriosus (P = .001), and corrected gestational age at the start of treatment (P = .007) were factors independently related to treatment failure with HFNC use.

CONCLUSIONS

We found HFNC revealed a significantly higher rate of treatment failure than NCPAP or NIPPV after extubation in preterm infants. The independent factors associated with treatment failure with HFNC use were histologic chorioamnionitis, treated patent ductus arteriosus, and a younger corrected gestational age at the start of treatment.

Combination Therapy with Etilefrine and Pleurodesis for Refractory Congenital Chylothorax

Etilefrine, a sympathomimetic agent, is reportedly effective against postoperative chylothorax. However, its effectiveness in treating congenital chylothorax was unknown. We report herein a case of refractory congenital chylothorax treated with etilefrine in a late preterm neonate with massive fetal chylous pleural effusion. The chylothorax was unresponsive to previous treatments, including dietary and pharmacological treatment and thoracic duct ligation. The pleural effusion decreased after intravenous etilefrine was begun on day of life (DOL) 84 and resolved after the addition of chemical pleurodesis with OK-432 on DOL 90. This combination therapy may be a viable treatment option for cases of congenital chylothorax that are unresponsive to other treatments.

Devil's staircase transition of the electronic structures in CeSb

Solids with competing interactions often undergo complex phase transitions with a variety of long-periodic modulations. Among such transition, devil's staircase is the most complex phenomenon, and for it, CeSb is the most famous material, where a number of the distinct phases with long-periodic magnetostructures sequentially appear below the Néel temperature. An evolution of the low-energy electronic structure going through the devil's staircase is of special interest, which has, however, been elusive so far despite 40 years of intense research. Here, we use bulk-sensitive angle-resolved photoemission spectroscopy and reveal the devil's staircase transition of the electronic structures. The magnetic reconstruction dramatically alters the band dispersions at each transition. Moreover, we find that the well-defined band picture largely collapses around the Fermi energy under the long-periodic modulation of the transitional phase, while it recovers at the transition into the lowest-temperature ground state. Our data provide the first direct evidence for a significant reorganization of the electronic structures and spectral functions occurring during the devil's staircase.

Risk model for severe postoperative complications after total pancreatectomy based on a nationwide clinical database

BACKGROUND

Total pancreatectomy is required to completely clear tumours that are locally advanced or located in the centre of the pancreas. However, reports describing clinical outcomes after total pancreatectomy are rare. The aim of this retrospective observational study was to assess clinical outcomes following total pancreatectomy using a nationwide registry and to create a risk model for severe postoperative complications.

METHODS

Patients who underwent total pancreatectomy from 2013 to 2017, and who were recorded in the Japan Society of Gastroenterological Surgery and Japanese Society of Hepato-Biliary-Pancreatic Surgery database, were included. Severe complications at 30 days were defined as those with a Clavien-Dindo grade III needing reoperation, or grade IV-V. Occurrence of severe complications was modelled using data from patients treated from 2013 to 2016, and the accuracy of the model tested among patients from 2017 using c-statistics and a calibration plot.

RESULTS

A total of 2167 patients undergoing total pancreatectomy were included. Postoperative 30-day and in-hospital mortality rates were 1·0 per cent (22 of 2167 patients) and 2·7 per cent (58 of 167) respectively, and severe complications developed in 6·0 per cent (131 of 2167). Factors showing a strong positive association with outcome in this risk model were the ASA performance status grade and combined arterial resection. In the test cohort, the c-statistic of the model was 0·70 (95 per cent c.i. 0·59 to 0·81).

CONCLUSION

The risk model may be used to predict severe complications after total pancreatectomy.

P1520 Aortic flow reversal caused by aortic regurgitation deteriorates renal function

Background

Chronic kidney disease is a growing public health problem. Renal dysfunction is known as a strong risk factor for cardiovascular disease and end-stage renal failure. The presence of pan-diastolic flow reversal in the abdominal aorta is a very specific sign of severe aortic regurgitation (AR). A higher aortic reverse/forward flow ratio is associated with lower intrarenal forward flow. However, the influence of AR on renal function has been poorly understood. We hypothesized that the aortic flow reversal reduces the renal artery forward flow and accordingly leads to renal dysfunction in patients with severe AR.

Methods

The study consisted of 21 consecutive patients (mean age 69 ± 11 years) with severe AR who underwent aortic valve replacement (AVR). We compared echocardiographic indices and the glomerular filtration rate (GFR) before and 603 ± 541 days after AVR.

Results

Blood pressure was 122 ± 16/54 ± 8 mmHg before AVR and 123 ± 16/76 ± 11 mmHg after AVR. After AVR, left ventricular (LV) end-diastolic dimension decreased from 57 ± 9 to 44 ± 5 mm and LV ejection fraction increased from 58 ± 12 to 60 ± 11 %. Estimated GFR significantly increased from 62.9 ± 18.9 to 71.8 ± 18.1 mL/min per 1.73 m2 after AVR (p = 0.003).

Conclusions An increase in aortic flow reversal caused by severe AR reduces forward flow into the kidney and thereby deteriorates renal function. This study demonstrated a key mediating role of central hemodynamic factors, particularly an exaggerated aortic flow reversal in renal dysfunction and severe AR.

Direct observation of imploded core heating via fast electrons with super-penetration scheme

Fast ignition (FI) is a promising approach for high-energy-gain inertial confinement fusion in the laboratory. To achieve ignition, the energy of a short-pulse laser is required to be delivered efficiently to the pre-compressed fuel core via a high-energy electron beam. Therefore, understanding the transport and energy deposition of this electron beam inside the pre-compressed core is the key for FI. Here we report on the direct observation of the electron beam transport and deposition in a compressed core through the stimulated Cu Kα emission in the super-penetration scheme. Simulations reproducing the experimental measurements indicate that, at the time of peak compression, about 1% of the short-pulse energy is coupled to a relatively low-density core with a radius of 70 μm. Analysis with the support of 2D particle-in-cell simulations uncovers the key factors improving this coupling efficiency. Our findings are of critical importance for optimizing FI experiments in a super-penetration scheme.

Band-dependent superconducting gap in SrFe2(As0.65P0.35)2 studied by angle-resolved photoemission spectroscopy

The isovalent-substituted iron pnictide compound SrFe₂(As_1−xP_x)₂ exhibits multiple evidence for nodal superconductivity via various experimental probes, such as the penetration depth, nuclear magnetic resonance and specific heat measurements. The direct identification of the nodal superconducting (SC) gap structure is challenging, partly because the presence of nodes is not protected by symmetry but instead caused by an accidental sign change of the order parameter, and also because of the three-dimensionality of the electronic structure. We have studied the SC gaps of SrFe₂(As_0.65P_0.35)₂ in three-dimensional momentum space by synchrotron and laser-based angle-resolved photoemission spectroscopy. The three hole Fermi surfaces (FSs) at the zone center have SC gaps with different magnitudes, whereas the SC gaps of the electron FSs at the zone corner are almost isotropic and k_z-independent. As a possible nodal SC gap structure, we propose that the SC gap of the outer hole FS changes sign around the Z-X [(0, 0, 2π) − (π, π, 2π)] direction.

A Pilot Study of Soluble Form of LOX-1 as a Novel Biomarker for Neonatal Hypoxic-Ischemic Encephalopathy

OBJECTIVE

To evaluate the soluble form of lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) as a biomarker of severity staging and prognosis in neonatal hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

We performed an observational study enrolling 27 infants with HIE and 45 control infants of gestational age ≥36 weeks and birth weight ≥1800 g. The HIE criteria were pH ≤7.0 or a base deficit ≥16 mmol/L within 60 minutes after birth, and a 10-minute Apgar score ≤5 or resuscitation time ≥10 minutes. HIE severity was evaluated using modified Sarnat staging. We measured plasma sLOX-1 level and assessed general and neurologic signs at discharge, and classified infants with no neurosensory impairments as intact survival.

RESULTS

sLOX-1 level within 6 hours after birth was correlated with the severity of HIE. sLOX-1 differentiated moderate-severe HIE (median, 1017 pg/mL; IQR, 553-1890 pg/mL) from mild HIE (median, 339 pg/mL; IQR, 288-595 pg/mL; P = .007). The sensitivity and specificity of the differentiation with a cutoff value of ≥550 pg/mL were 80.0% and 83.3%, respectively. In 19 infants with therapeutic hypothermia, a sLOX-1 cutoff value of <1000 pg/mL differentiated intact survival (median, 761 pg/mL; IQR, 533-1610 pg/mL) from death or neurosensory impairment (median, 1947 pg/mL; IQR, 1325-2506 pg/mL; P = .019) with 100% specificity and a positive predictive value.

CONCLUSION

sLOX-1 may be a useful biomarker of neonatal HIE for severity staging and outcome prediction. Further investigations will facilitate its clinical use.

First report on USA300 outbreak in a neonatal intensive care unit detected by polymerase chain reaction-based open reading frame typing in Japan

Outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) in the neonatal intensive care unit (NICU) have been reported worldwide. Some outbreaks were caused by USA300, which is a community-associated MRSA clone. In 2011, polymerase chain reaction-based open reading frame typing (POT) for the initial MRSA isolates from all inpatients was started at the Tokyo Metropolitan Children's Medical Center. From March 2014 to April 2015, a total of 131 MRSA strains were isolated, 104 of which were analyzed as healthcare-associated MRSA. Thirteen stains (12.5%) had a POT number of 106-9-93, which strongly suggested USA300; these included 6 from nasal swabs, 6 from blood cultures and 1 from subcutaneous pus. All the MRSA strains were isolated from patients in the NICU; were typed as sequence type 8, spa type t008, and staphylococcal cassette chromosome type mec IVa; and possessed the lukS-lukF and arginine catabolic mobile element-arcA gene. Pulsed-field gel electrophoresis of all the strains, with USA300-0114 as a reference, showed indistinguishable banding pattern. Based on these results, POT was useful in recognizing this first MRSA outbreak of USA300 in a Japanese NICU and was advantageous in terms of swiftness, less cost and monitoring change of the epidemic MRSA lineage.

Comparison of USA300 with non-USA300 methicillin-resistant Staphylococcus aureus in a neonatal intensive care unit

OBJECTIVES

Reports of USA300 methicillin-resistant Staphylococcus aureus (MRSA) strain were still scarce in neonatal intensive care units (NICUs) and the relationship of USA300 MRSA to clinical infections is still controversial. The primary outcome was the incidence of MRSA infections caused by the USA300 and non-USA300 strains at a NICU in Japan.

METHODS

This retrospective cohort study was conducted between November 2011 and October 2016 at Tokyo Metropolitan Children's Medical Center in Japan. All MRSA isolated after 48h of hospitalization were included for analysis by pulsed-field gel electrophoresis (PFGE) using the standard USA300 strain. Genes were tested for Panton-Valentine leukocidin (PVL) and arginine catabolic mobile element (ACME). A whole genome sequence was performed for representative isolates of USA300.

RESULTS

In total, 109 MRSA isolates were included for analysis. PFGE classified 34 and 75 isolates of USA300 and non-USA300 MRSA, respectively. Both PVL and ACME genes were detected in USA300 and non-USA300 strains at rate of 100% (34/34) and 5.3% (4/75), respectively (P<0.05). There was no statistically significant difference in the proportion of clinical diseases between USA- 300 and non-USA 300 strains.

CONCLUSIONS

Infants with USA300 MRSA infection did not differ significantly from those with non-USA300 MRSA infection.

Antimicrobial Stewardship Program in a Pediatric Intensive Care Unit

We conducted an antimicrobial stewardship program in a pediatric intensive care unit. An interrupted time-series analysis revealed a significant reduction in level and trend of days of therapy per 1000 patient-days for antipseudomonal agents. No increase in adverse patient outcomes was found.

Variable tibiofemoral articular contact stress in fixed-bearing total knee arthroplasties

BACKGROUND

Rotational allowance at the tibiofemoral joint would be required during deep flexion. However, the amount of flexion and rotation has not been investigated in modern total knee arthroplasty (TKA) designs. The present study aimed to determine the contact stress in five posterior-stabilized fixed-bearing TKA designs.

HYPOTHESIS

We hypothesized that the contact area and stresses at the tibiofemoral articular surfaces vary according to the type of implant design and tested condition.

MATERIALS AND METHODS

The contact area and mean and peak contact stresses at the tibiofemoral articular surfaces were determined when a compressive load of 1200N was applied to a NexGen LPS Flex, Scorpio NRG, Genesis II, PFC Sigma, and Foundation implant. Measurements were performed at 0° and 45° flexion with 0°, 5°, 10°, and 15° rotation, and at 90° and 135° flexion with 0, 5°, 10°, 15°, and 20° rotation.

RESULTS

The LPS Flex showed that the femoral component could not achieve 20° rotation at 135° flexion. The Scorpio NRG showed less than 20MPa of contact stress at all conditions. The Genesis II showed higher contact stress than 20MPa at 135° flexion with 20° rotation. The PFC Sigma showed that the femoral component could not achieve >10° rotation at any flexion angle. The Foundation showed more than 20MPa of contact stress at 90° flexion with 20° rotation and at 135° flexion with 10°, 15°, and 20° rotation.

DISCUSSION

Surgeons should be more aware of the variable contact conditions of the tibiofemoral articular surfaces in individual TKA designs.

LEVEL OF EVIDENCE

Level IV, basic science study.

Sibling visits and viral infection in the neonatal intensive care unit

BACKGROUND

Sibling visits to the neonatal intensive care unit (NICU) are a part of family-centered care, which is now being increasingly endorsed as a positive development in patient care. Sibling visits, however, pose a risk of viral infection, and hence many NICU in Japan impose strict limits on the practice. The aim of this study was therefore to assess whether sibling visits to the NICU are related to an increase in the nosocomial viral infection rate.

METHODS

This retrospective study was conducted between April 2012 and March 2017 at Tokyo Metropolitan Children's Medical Center in Japan. Sibling visits were implemented after screening for symptoms of viral illness. Symptomatic patients in the NICU were tested for common viruses on rapid antigen test and polymerase chain reaction. The number of sibling visits and the rate of nosocomial viral infections were examined on Spearman's correlation test.

RESULTS

The total number of sibling visits and rate of nosocomial viral infection in the NICU was 102 and 0.068 per 1,000 patient-days during the study period, respectively. The number of enterovirus, respiratory syncytial virus, human metapneumovirus, influenza virus A, and Herpes simplex virus infections was 3, 2, 1, 1, 1, and 1, respectively. No infections were identified after sibling visits. The number of sibling visits and the rate of nosocomial viral infections were not correlated (correlation coefficient, -0.1; P = 0.873).

CONCLUSION

Sibling visits to the NICU did not result in an increase in the nosocomial viral infection rate.

Sustained pediatric antimicrobial stewardship program with consultation to infectious diseases reduced carbapenem resistance and infection-related mortality

OBJECTIVE

The impact of pediatric antimicrobial stewardship programs (ASP) on antimicrobial resistance (AMR) remains largely unknown. This study aimed to evaluate the AMR for carbapenem of Gram-negative bacilli (GNB) and carbapenem use with infectious diseases consultation after the implementation of an ASP.

METHODS

This quasi-experimental study was conducted at Tokyo Metropolitan Children's Medical Center in Japan. The pre- and post-intervention periods were April 2010 to September 2011 and October 2011 to March 2017, respectively. The pre-intervention phase consisted of consultations with the infectious diseases service alone. The ASP was implemented during the post-intervention phase. The carbapenem resistance rates of GNB were calculated. The correlation between carbapenem resistance rates and carbapenem day of therapy (DOT) was examined. The outcome metrics were compared by average length of hospitalization, all-cause mortality, and infection-related mortality.

RESULTS

A positive correlation was observed between the carbapenem resistance rate in Pseudomonas aeruginosa and DOT (0.76, p=0.04). The carbapenem resistance rate in P. aeruginosa (p<0.01) and DOT (p<0.01) decreased significantly in the post-intervention period. The length of hospitalization (p<0.01) and infection-related mortality (p=0.05) decreased in the post-intervention period.

CONCLUSIONS

A sustained ASP with additional consultation with the infectious disease service reduced carbapenem use and resistance in P. aeruginosa, leading to favorable outcomes in terms of length of hospitalization and infection-related mortality.

A Case of Congenital Folliculitis Caused by Pseudomonas aeruginosa in a Preterm Neonate

Intrauterine infections are associated with life-threatening neonatal conditions such as sepsis, intracranial hemorrhage, and chronic lung disease. Herein we present a case of generalized congenital folliculitis caused by Pseudomonas aeruginosa in a preterm neonate of 27 weeks gestational age successfully treated with antibiotics. Folliculitis is an important manifestation of intrauterine P. aeruginosa infection, and prompt, effective treatment is crucial to ensuring a good prognosis.

Characterisation of osteophytes as an autologous bone graft source: An experimental study in vivo and in vitro

Objectives

Osteophytes are products of active endochondral and intramembranous ossification, and therefore could theoretically provide significant efficacy as bone grafts. In this study, we compared the bone mineralisation effectiveness of osteophytes and cancellous bone, including their effects on secretion of growth factors and anabolic effects on osteoblasts.

Methods

Osteophytes and cancellous bone obtained from human patients were transplanted onto the calvaria of severe combined immunodeficient mice, with Calcein administered intra-peritoneally for fluorescent labelling of bone mineralisation. Conditioned media were prepared using osteophytes and cancellous bone, and growth factor concentration and effects of each graft on proliferation, differentiation and migration of osteoblastic cells were assessed using enzyme-linked immunosorbent assays, MTS ((3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium)) assays, quantitative real-time polymerase chain reaction, and migration assays.

Results

After six weeks, the area of mineralisation was significantly higher for the transplanted osteophytes than for the cancellous bone (43803 μm₂, sd 14660 versus 9421 μm₂, sd 5032, p = 0.0184, one-way analysis of variance). Compared with cancellous bone, the conditioned medium prepared using osteophytes contained a significantly higher amounts of transforming growth factor (TGF)-β1 (471 pg/ml versus 333 pg/ml, p = 0.0001, Wilcoxon rank sum test), bone morphogenetic protein (BMP)-2 (47.75 pg/ml versus 32 pg/ml, p = 0.0214, Wilcoxon rank sum test) and insulin-like growth factor (IGF)-1 (314.5 pg/ml versus 191 pg/ml, p = 0.0418, Wilcoxon rank sum test). The stronger effects of osteophytes towards osteoblasts in terms of a higher proliferation rate, upregulation of gene expression of differentiation markers such as alpha-1 type-1 collagen and alkaline phosphate, and higher migration, compared with cancellous bone, was confirmed.

Conclusion

We provide evidence of favourable features of osteophytes for bone mineralisation through a direct effect on osteoblasts. The acceleration in metabolic activity of the osteophyte provides justification for future studies evaluating the clinical use of osteophytes as autologous bone grafts.

Cite this article: K. Ishihara, K. Okazaki, T. Akiyama, Y. Akasaki, Y. Nakashima. Characterisation of osteophytes as an autologous bone graft source: An experimental study in vivo and in vitro. Bone Joint Res 2017;6:73–81. DOI: 10.1302/2046-3758.62.BJR-2016-0199.R1.

Serous cystic neoplasm of the pancreas: a multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)

OBJECTIVES

Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality.

DESIGN

Retrospective multinational study including SCN diagnosed between 1990 and 2014.

RESULTS

2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58 years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40 mm (2-200)), 9% had resection beyond 1 year of follow-up (3 years (1-20), size at diagnosis: 25 mm (4-140)) and 39% had no surgery (3.6 years (1-23), 25.5 mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1 year (n=1271), size increased in 37% (growth rate: 4 mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1).

CONCLUSIONS

After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN.

TRIAL REGISTRATION NUMBER

IRB 00006477.

Correction of coronal alignment correlates with reconstruction of joint height in unicompartmental knee arthroplasty

OBJECTIVES

Because there have been no standard methods to determine pre-operatively the thickness of resection of the proximal tibia in unicompartmental knee arthroplasty (UKA), information about the relationship between the change of limb alignment and the joint line elevation would be useful for pre-operative planning. The purpose of this study was to clarify the correlation between the change of limb alignment and the change of joint line height at the medial compartment after UKA.

METHODS

A consecutive series of 42 medial UKAs was reviewed retrospectively. These patients were assessed radiographically both pre- and post-operatively with standing anteroposterior radiographs. The thickness of bone resection at the proximal tibia and the distal femur was measured radiographically. The relationship between the change of femorotibial angle (δFTA) and the change of joint line height, was analysed.

RESULTS

The mean pre- and post-operative FTA was 180.5° (172.2° to 184.8°) and 175.0° (168.5° to 178.9°), respectively. The mean δFTA was 5.5° (2.3° to 10.1°). The joint line elevation of the tibia (JLET) was 4.4 mm (2.1 to 7.8). The δFTA was correlated with the JLET (correlation coefficient 0.494, p = 0.0009).

CONCLUSIONS

This study indicated that there is a significant correlation between the change of limb alignment and joint line elevation. This observation suggests that it is possible to know the requirement of elevation of the joint line to obtain the desired correction of limb alignment, and to predict the requirement of bone resection of the proximal tibia pre-operatively. Cite this article: Bone Joint Res 2015;4:128-133.

Correction of coronal alignment correlates with reconstruction of joint height in unicompartmental knee arthroplasty

Objectives

Because there have been no standard methods to determine pre-operatively the thickness of resection of the proximal tibia in unicompartmental knee arthroplasty (UKA), information about the relationship between the change of limb alignment and the joint line elevation would be useful for pre-operative planning. The purpose of this study was to clarify the correlation between the change of limb alignment and the change of joint line height at the medial compartment after UKA.

Methods

A consecutive series of 42 medial UKAs was reviewed retrospectively. These patients were assessed radiographically both pre- and post-operatively with standing anteroposterior radiographs. The thickness of bone resection at the proximal tibia and the distal femur was measured radiographically. The relationship between the change of femorotibial angle (δFTA) and the change of joint line height, was analysed.

Results

The mean pre- and post-operative FTA was 180.5° (172.2° to 184.8°) and 175.0° (168.5° to 178.9°), respectively. The mean δFTA was 5.5° (2.3° to 10.1°). The joint line elevation of the tibia (JLET) was 4.4 mm (2.1 to 7.8). The δFTA was correlated with the JLET (correlation coefficient 0.494, p = 0.0009).

Conclusions

This study indicated that there is a significant correlation between the change of limb alignment and joint line elevation. This observation suggests that it is possible to know the requirement of elevation of the joint line to obtain the desired correction of limb alignment, and to predict the requirement of bone resection of the proximal tibia pre-operatively. Cite this article: Bone Joint Res 2015;4:128–133

Congenital dacryocystoceles controlled by nCPAP via nasal mask in a neonate

Congenital dacryocystocele is a relatively rare type of nasolacrimal duct obstruction that may induce respiratory distress during the early neonatal period. We encountered a case of bilateral congenital dacryocystoceles with intranasal cysts in a premature infant delivered at 34 weeks of gestation. The patient developed symptoms of respiratory failure immediately after birth, but no ophthalmologic symptoms. Treatment with nasal continuous positive airway pressure via a nasal mask, instead of a nasal prong, effectively relieved the symptoms. Early diagnosis and appropriate treatment are critical for infants with nasal obstruction.

Histidine-rich protein as a possible origin of free amino acids of stratum corneum

The origin of free amino acids and/or their metabolites of the stratum corneum was investigated by pulse-chase experiments using hairless mice. Two, 24, 48, and 72 hrs after the animals were pulse-chased with 3H-histidine or 3H-arginine, radioactivity was determined in the following three fractions of the epidermis: the 0.1 N HClO4 soluble, ethanol soluble fraction (Fr. I); the 0.1N NClO4 soluble, ethanol insoluble fraction (Fr. II); and the 0.1 N HClO4 insoluble, 8M urea soluble fraction (Fr. III). Radioactivity of the epidermal proteins was also determined in SDS-PAGE gels by the gel slicing method. At first, 3H-histidine and/or 3H-arginine were predominantly incorporated into Fr. III, especially into a certain epidermal protein which showed little mobility on SDS-PAGE. Subsequently, 3H, once incorporated into Fr. III, appeared to shift from Fr. III to Fr. II and, simultaneously, from the top band(s) to a band of 32,000 daltons. As a result of amino acid analysis, a protein of Fr. II was considered a histidine-rich protein corresponding to HRP-II of the new born rats of Ball et al. After 48 hrs, as the radioactivities of Fr. III and Fr. II decreased remarkably, Fr. I gradually increased in radioactivity. The major radioactive substances in Fr. I at 72 hrs were identified as 3H-histidine and 3H-urocanic acid when 3H-histidine was used as a tracer, and as 3H-arginine, 3H-ornithine, and 3H-citrulline in the case of 3H-arginine. The amino acid composition of the histidine-rich protein was very similar to that of the free amino acids of the stratum corneum in the hairless mouse, in which some amino acid metabolites were considered as their precursor amino acids. These results strongly suggest that the free amino acids and/or their metabolites of the stratum corneum might be the final products of a degradation of the histidine-rich protein.

Phosphorylation of Smad2/3 at the specific linker threonine residue indicates slow-cycling esophageal stem-like cells before re-entry to the cell cycle

The stem cell compartment in the esophageal epithelium is possibly located in the basal layer. We have identified significant expression of Smad2/3, phosphorylated at specific linker threonine residues (pSmad2/3L-Thr), in the epithelial cells of murine stomach and intestine, and have suggested that these cells are epithelial stem cells. In this study, we explore whether pSmad2/3L-Thr could serve as a biomarker for esophageal stem cells. We examined esophageal tissues from normal C57BL/6 mice and those with esophagitis. Double immunofluorescent staining of pSmad2/3L-Thr with Ki67, CDK4, p63, or CK14 was performed. After immunofluorescent staining, we stained the same sections with hematoxylin-eosin and observed these cells under a light microscope. We used the 5-bromo-2-deoxyuridine (BrdU) labeling assay to examine label retention of pSmad2/3L-Thr immunostaining-positive cells. We collected specimens 5, 10, 15 and 20 days after repeated BrdU administrations and observed double immunofluorescent staining of pSmad2/3L-Thr with BrdU. In the esophagus, pSmad2/3L-Thr immunostaining-positive cells were detected in the basal layer. These cells were detected between Ki67 immunostaining-positive cells, but they were not co-localized with Ki67. pSmad2/3L-Thr immunostaining-positive cells showed co-localization with CDK4, p63, and CK14. Under a light microscope, pSmad2/3L-Thr immunostaining-positive cells indicated undifferentiated morphological features. Until 20 days follow-up period, pSmad2/3L-Thr immunostaining-positive cells were co-localized with BrdU. pSmad2/3L-Thr immunostaining-positive cells significantly increased in the regeneration phase of esophagitis mucosae, as compared with control mice (esophagitis vs.

CONTROL

6.889 ± 0.676/cm vs. 4.293 ± 0.659/cm; P < 0.001). We have identified significant expression of pSmad2/3L-Thr in the specific epithelial cells of murine esophagi. We suggest that these cells are slow-cycling epithelial stem-like cells before re-entry to the cell cycle.