Hydrogen gas can ameliorate seizure burden during therapeutic hypothermia in asphyxiated newborn piglets

BACKGROUND

We previously reported that hydrogen (H2) gas combined with therapeutic hypothermia (TH) improved short-term neurological outcomes in asphyxiated piglets. However, the effect on seizure burden was unclear. Using amplitude-integrated electroencephalography (aEEG), we compared TH + H2 with TH alone in piglets 24 h after hypoxic-ischemic (HI) insult.

METHODS

After a 40-min insult and resuscitation, 36 piglets ≤24 h old were divided into three groups: normothermia (NT, n = 14), TH alone (33.5 ± 0.5 °C, 24 h, n = 13), and TH + H2 (2.1-2.7% H2 gas, 24 h, n = 9). aEEG was recorded for 24 h post-insult and its background pattern, status epilepticus (SE; recurrent seizures lasting >5 min), and seizure occurrence (Sz; occurring at least once but not fitting the definition of SE) were evaluated. Background findings with a continuous low voltage and burst suppression were considered abnormal.

RESULTS

The percentage of piglets with an abnormal aEEG background (aEEG-BG), abnormal aEEG-BG+Sz and SE was lower with TH + H2 than with TH at 24 h after HI insult. The duration of SE was shorter with TH + H2 and significantly shorter than with NT.

CONCLUSIONS

H2 gas combined with TH ameliorated seizure burden 24 h after HI insult.

IMPACT

In this asphyxiated piglet model, there was a high percentage of animals with an abnormal amplitude-integrated electroencephalography background (aEEG-BG) after hypoxic-ischemic (HI) insult, which may correspond to moderate and severe hypoxic-ischemic encephalopathy (HIE). Therapeutic hypothermia (TH) was associated with a low percentage of piglets with EEG abnormalities up to 6 h after HI insult but this percentage increased greatly after 12 h, and TH was not effective in attenuating seizure development. H2 gas combined with TH was associated with a low percentage of piglets with an abnormal aEEG-BG and with a shorter duration of status epilepticus at 24 h after HI insult.

Next-generation sequencing-based detection of Ureaplasma in the gastric fluid of neonates with respiratory distress and chorioamnionitis

BACKGROUND

Respiratory distress is common in neonates admitted to neonatal intensive care units. Additionally, infectious diseases such as intrauterine infections or vertical transmission are important underlying causes of respiratory failure. However, pathogens often cannot be identified in neonates, and there are many cases in which antibacterial drugs are empirically administered. Next-generation sequencing (NGS) is advantageous in that it can detect trace amounts of bacteria that cannot be detected by culturing or bacteria that are difficult to cultivate. However, there are few reports on the diagnosis of infectious diseases using NGS in the neonatal field, especially those targeting respiratory distress.

OBJECTIVE

The purpose of our study was to investigate the microorganisms associated with neonatal respiratory distress and to determine whether less invasive collection specimens such as plasma and gastric fluid are useful.

METHODS

Neonates were prospectively recruited between January and August 2020 from Nagoya University Hospital. The inclusion criteria were as follows: 1) admission to the neonatal intensive care unit; 2) respiratory distress presentation within 48 h of birth; and 3) suspected infection, collection of blood culture, and administration of antibiotics. Plasma samples and blood cultures were simultaneously collected. Gastric fluid samples were also collected if the patient was not started on enteral nutrition. Information on the patients and their mothers were collected from the medical records. DNA was extracted from 140 µL of plasma and gastric fluid samples. DNA sequencing libraries were prepared, and their quality was analyzed. DNA libraries were sequenced using high-throughput NGS. The NGS data of plasma and gastric fluid samples were analyzed using the metagenomic pipeline PATHDET, which calculated the number of reads assigned to microorganisms and their relative abundance. Putative pathogens were listed.

RESULTS

Overall, 30 plasma samples and 25 gastric fluid samples from 30 neonates were analyzed. Microorganism-derived reads of gastric fluid samples were significantly higher than those of plasma samples. Transient tachypnea of the newborn was the most common cause of respiratory distress with 13 cases (43%), followed by respiratory distress syndrome with 7 cases (23%). There were 8 cases (29%) of chorioamnionitis and 7 cases (25%) of funisitis pathologically diagnosed. All blood cultures were negative, and only two gastric fluid cultures were positive for group B Streptococcus (Patient 15) and Candida albicans (Patient 24). Putative pathogens that met the positive criteria for PATHET were detected in four gastric fluid samples, one of which was group B Streptococcus from Patient 15. In the gastric fluid sample of Patient 24, Candida albicans were detected by NGS but did not meet the positive criteria for PATHDET. Cluster analysis of the plasma samples divided them into two study groups, and the indicator genera of each cluster (Phormidium or Toxoplasma) are shown in Figure 1. Clinical findings did not show any significant differences between the two groups. Cluster analysis of the gastric fluid samples divided them into three study groups, and the indicator genera of each cluster (Ureaplasma, Nostoc, and Streptococcus) are shown in Figure 2. The incidence rate of chorioamnionitis was significantly higher in Ureaplasma group than in the other two groups.

CONCLUSION

Gastric fluid may be useful for assessing neonatal patients with respiratory distress. To the best of our knowledge, this was the first study to reveal that the presence of Ureaplasma in the gastric fluid of neonates with respiratory distress was associated with chorioamnionitis. The early diagnosis of intra-amniotic infections using gastric fluid and its treatment may change the treatment strategy for neonatal respiratory distress. Screening for Ureaplasma in neonates with respiratory distress may reduce the need for empirical antibiotic administration. Further research is required to confirm these findings.

Total Hydrocortisone Dosage in the Neonatal Period May Be Related to Low Developmental Quotient in Extremely Low Birth Weight Infants: A Retrospective Cohort Study

INTRODUCTION

The effects of hydrocortisone (HDC) administration to extremely low birth weight (ELBW) infants on later development remain unclear. This study examined the association between HDC dosage during neonatal period and neurodevelopmental outcomes in ELBW infants.

METHODS

This study was a retrospective cohort study conducted in eight centers in Japan. The subjects of this study were ELBW infants born between April 2015 and March 2017. The association between postnatal total HDC dosage up to 36 weeks postmenstrual age and the developmental quotient (DQ) at 3 years of age was examined. Multiple linear regression evaluated the association, adjusting for weeks of gestation, birth weight, and the presence of bronchopulmonary dysplasia, late-onset circulatory collapse, intracranial hemorrhage, necrotizing enterocolitis, and sepsis.

RESULTS

This study included 218 ELBW infants, of whom 144 underwent a developmental test at 3 years of age. Simple linear regression analysis revealed a significant association between total HDC dosage and DQ at 3 years of age (coefficients: -2.65, 95% CI: -3.73, -1.57). Multiple linear regression analysis adjusted for the presence of bronchopulmonary dysplasia and late-onset circulatory collapse also revealed a significant association between total HDC dosage and DQ at 3 years of age (coefficients: -2.66, 95% CI: -3.89, -1.42).

CONCLUSION

Higher total HDC dosage up to 36 weeks postmenstrual age in ELBW infants was associated with impaired neurodevelopmental outcomes. Although HDC is often needed in the treatment of ELBW infants, clinicians should be aware that an increased dose of HDC may be associated with impaired neurodevelopmental outcomes.

Prolonged requirements for mechanical ventilation and tube feeding support predicted 18-month outcomes for neonatal encephalopathy

AIM

We evaluated the predictive ability of prolonged requirements for mechanical ventilation or tube feeding support for 18-month composite outcomes in infants with hypoxic-ischaemic encephalopathy treated with hypothermia.

METHODS

This retrospective, nationwide, observational study focused on newborn infants registered in Japan's Baby Cooling Registry between 1 January 2012 and 31 December 2016. The adverse outcomes were defined as death or survival with cerebral palsy, visual or auditory impairment or the requirement for mechanical ventilation or tube feeding at 18 months of age.

RESULTS

Adverse outcomes occurred in 165 (28%) of the 591 children in the final cohort. These were predicted by prolonged dependence on mechanical ventilation or tube feeding for more than seven and more than 14 days. The respective values were positive predictive value 0.34 (95% CI 0.33-0.34) and 0.60 (95% CI 0.56-0.62), negative predictive value 0.97 (95% CI 0.91-0.99) and 0.93 (95% CI 0.90-0.95) and area under the curve 0.59 (95% CI 0.54-0.64) and 0.81 (95% CI 0.77-0.85).

CONCLUSION

Prolonged dependence on mechanical ventilation or tube feeding for more than 14 days may be useful in predicting 18-month outcomes in newborn infants who have received therapeutic hypothermia.

Gait performance and dual-task costs in school-aged children with Down syndrome

OBJECTIVE

This cross-sectional observational study aimed to assess gait performance, its correlation with physical functions, and its dual-task costs in children with Down syndrome (DS), to investigate their gait adaptations.

METHODS

Gait performance with or without movie-watching tasks was evaluated in 17 children with DS (age, 6-12 years) and 51 age- and sex-matched controls, using three-dimensional gait analysis. We compared participants' demographics, physical functions, and gait performance without tasks between the two groups. In the DS group, correlations between physical functions, the intelligence quotient, and gait variables were assessed. Dual-task costs for gait variables were also compared between the two groups.

RESULTS

Children with DS showed poorer balance function and muscle strength and lower gait quality than the control group. In the DS group, there was a significant positive correlation between gait speed, step length, and intelligence quotient. There were no correlations between the balance function, muscle strength, intelligence quotient, and gait quality. Dual-task costs for gait speed, step length, and cadence were greater in the DS group; however, there was no significant difference in dual-task costs for gait quality between the two groups.

CONCLUSION

These findings highlight the importance of providing appropriate interventions for motor functions in school-aged children with DS based on their gait performance in single- and dual-task conditions, as well as on their intelligence quotient.

Predictive value of the Thompson score for short-term adverse outcomes in neonatal encephalopathy

BACKGROUND

To explore the predictive value of the Thompson score during the first 4 days of life for estimating short-term adverse outcomes in neonatal encephalopathy.

METHODS

This observational study evaluated infants with neonatal encephalopathy (≥36 weeks of gestation) registered in a multicenter cohort of cooled infants in Japan. The Thompson score was evaluated at 0-24, 24-48, 48-72, and 72-90 h of age. Adverse outcomes included death, survival with respiratory impairment (requiring tracheostomy), or survival with feeding impairment (requiring gavage feeding) at discharge.

RESULTS

Of the 632 infants, 21 (3.3%) died, 59 (9.3%) survived with respiratory impairment, and 113 (17.9%) survived with feeding impairment. The Thompson score throughout the first 4 days accurately predicted death, respiratory impairment, or feeding impairment. The 72-90 h score showed the highest accuracy. A cutoff of ≥15 had a sensitivity of 0.85 and specificity of 0.92 for death or respiratory impairment, while a cutoff of ≥14 had a sensitivity of 0.71 and a specificity of 0.92 for death, respiratory or feeding impairment.

CONCLUSION

A high Thompson score during the first 4 days of life, especially at 72-90 h could thus be useful for estimating the need for prolonged life support.

IMPACT

The Thompson score on days 1-4 of age was useful in predicting death and respiratory or feeding impairments. The 72-90 h Thompson score showed the highest predictive capability. Owing to the rarity of withdrawal of life-sustaining treatment in Japan, 43% of infants with persistent severe encephalopathy with a Thompson score of ≥15 at 72-90 h of age could regain spontaneous breathing, be extubated, and survive without tracheostomy. Meanwhile, approximately 50% of infants who survived without tracheostomy required gavage feeding. Our results could provide useful information for clinical decision making regarding infants with persistent severe encephalopathy.

Determinants for residual symptoms in chronic thromboembolic pulmonary hypertension patients with mean pulmonary arterial pressure <25 mmHg after balloon pulmonary angioplasty

Background

Balloon pulmonary angioplasty (BPA) improves hemodynamics and exercise capacity in inoperable patients with chronic thromboembolic pulmonary hypertension (CTEPH). However, some symptoms, such as dyspnea on exertion, had remained in more than half of the patients even after BPA could decrease mean pulmonary artery pressure (PAP) <25 mmHg in a Japanese multicenter registry. In addition, previous report indicated that impaired exercise capacity was observed in about half of the patients with CTEPH who achieved mean PAP <25 mmHg at rest after BPA. Lowering mean PAP alone would not be sufficient as a treatment goal of BPA to eliminate residual symptoms in the patients.

Purpose

The purpose of this study was to elucidate the determinants of residual symptom in patients who had achieved mean PAP <25 mmHg after BPA.

Methods

Among 310 CTEPH patients who received BPA in our center, 217 patients (70.0%) could achieve mean PAP <25mmHg at six months after the final BPA were enrolled in this study. The patients were divided into two groups based on the necessity of additional BPA due to residual symptoms; additional BPA group and non-additional BPA group. Clinical parameters including resting hemodynamics at 6 months follow up were retrospectively investigated between the two groups.

Results

Additional BPA had been underwent in 67 patients (30.9%). No significant differences in mean PAP were identified between the additional and non-additional BPA groups (20.4±2.5 mmHg vs. 19.7±2.7 mmHg, p=0.106). In additional BPA group, cardiac index (CI), heart rate (HR) and percutaneous oxygen saturation (SpO2) was lower than non-additional BPA group, and pulmonary vascular resistance (PVR) was higher than non-additional BPA group (CI, 2.51±0.41 L/min/m2 vs. 2.72±0.56 L/min/m2, p=0.016, HR, 62.9±9.7 bpm vs. 67.8±10.8 bpm, p=0.003, SpO2, 94.3±3.7% vs. 95.9±3.5%, p<0.001, PVR, 3.67±1.18 W.U. vs. 3.11±1.09 W.U. p=0.001). In a multivariate analysis, CI, SpO2 and PVR were associated with residual symptoms requiring additional treatment in patients with mean PAP <25mmHg after BPA (95% confidence interval: CI; 0.221–0.900, SpO2; 0.825–0.976, PVR; 1.000–1.785).

Conclusion

Low CI and SpO2 and High PVR were determinants for residual symptoms in CTEPH patients who could achieve mean PAP <25 mmHg after BPA. To eliminate the residual symptoms, treatment goals of BPA in inoperable CTEPH patients should be increasing CI and SpO2 and lowering PVR in addition to normalizing mean PAP.

Funding Acknowledgement

Type of funding sources: None.

High incidence of pulmonary artery thrombosis after balloon pulmonary angioplasty in CTEPH patients receiving direct oral anticoagulants

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) requires life-long anticoagulant therapy, whereas limited data exist on the safety and efficacy of direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) along with balloon pulmonary angioplasty (BPA).

Objectives

To evaluate outcomes and complications in CTEPH following BPA for individuals receiving DOACs or VKAs.

Methods

Consecutive CTEPH patients underwent BPA from September 2014 to August 2021 were included in a retrospective analysis. Complications during BPA, post-BPA hemodynamics and bleeding events were obtained from patient's medical records. Our routine follow-up “selective” pulmonary angiography, to evaluate all segmental pulmonary arteries one by one at six months and every year after final BPA session, was performed to elucidate the incidence of in-situ fresh floating thrombus.

Results

Of total 250 individuals, 104 were treated with DOACs and 146 with VKAs following BPA. Mean observation period was 905 (SD ± 660) days. Total 1278 BPA sessions were performed among the period in which 409 sessions were treated with DOACs and 869 sessions with VKAs. Significant improvements in hemodynamics and functional status were observed in both groups following BPA. There was no significant difference of hemoptysis during BPA between DOACs and VKAs (7.1% vs 10.1%, P=0.131). Major bleeding events during observation period were equivalent in those treated with DOACs and VKAs. No significant re-elevation of pulmonary artery pressure was observed in both groups after BPA. Follow-up selective pulmonary angiography identified in-situ fresh floating thrombus in pulmonary artery in 22 cases of total 769 follow-up sessions. The occurrence of fresh thrombus was significantly higher in those receiving DOACs than VKAs in therapeutic range of PT-INR >1.8 (3.9% vs 1.2%, P=0.023) whereas no significant difference between DOACs and overall VKAs (3.9% vs 2.4%, P=0.177)

Conclusions

Post-BPA hemodynamic outcomes and bleeding events appear unaffected by choice of anticoagulant. However, the incidence of in-situ pulmonary thrombosis detected by selective pulmonary angiography was significantly higher in those receiving DOACs than VKAs in therapeutic range, suggesting inadequate anticoagulation under current dose of DOACs. Our study provides a rationale for further examination to evaluate the efficacy of DOACs in CTEPH.

Funding Acknowledgement

Type of funding sources: None.

Physical functions and gait performance in school-aged children born late preterm

BACKGROUND

Children born late preterm (LP) have an increased risk of poor developmental motor outcomes.

AIMS

This study aimed to assess physical functions and gait performance in school-aged children born LP.

STUDY DESIGN

Cross-sectional study.

SUBJECTS

Physical functions and gait performance were evaluated in 277 children aged 6-10 years born LP (n = 22) and full-term (FT) (n = 255).

OUTCOME MEASURES

Physical function tests consisted of five times sit-to-stand test (FTSST), one-leg standing time, and grip strength. FTSST was used to assess the functional muscle strength of the lower limbs and dynamic balance function. Gait performance tests included gait quality, spatiotemporal gait parameters, and gait variability. Clinical data, physical functions, and gait performance were compared between two groups. Furthermore, logistic regression analysis was performed to assess the association between all variables and LP birth.

RESULTS

In physical function tests, children born LP showed poorer FTSST than those born FT (p = 0.039). No significant difference in gait performance tests were identified between the two groups. Logistic regression analysis of FTSST for LP (adjusted for age at assessment) revealed that FTSST was significantly associated with LP birth (p = 0.004, odds ratio = 1.579, 95% confidence interval = 1.160-2.149).

CONCLUSIONS

We demonstrated the physical functions and gait performance in school-aged children born LP. Our findings indicate that it is important to focus on the decreased functional muscle strength of the lower limbs and reduced dynamic balance function related to LP birth to improve functional mobility in children born LP.

Study of the K_{L}→π^{0}νν[over ¯] Decay at the J-PARC KOTO Experiment

The rare decay K_{L}→π^{0}νν[over ¯] was studied with the dataset taken at the J-PARC KOTO experiment in 2016, 2017, and 2018. With a single event sensitivity of (7.20±0.05_{stat}±0.66_{syst})×10^{-10}, three candidate events were observed in the signal region. After unveiling them, contaminations from K^{±} and scattered K_{L} decays were studied, and the total number of background events was estimated to be 1.22±0.26. We conclude that the number of observed events is statistically consistent with the background expectation. For this dataset, we set an upper limit of 4.9×10^{-9} on the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level.

Design of a prospective multicenter randomized controlled trial evaluating the effects of gastric lavage on coffee-ground emesis in neonates: study protocol

Neonates who swallow a considerable amount of maternal blood may exhibit vomiting and suckling disorder during the first few days of the postnatal period. Some clinicians treat these neonates with gastric lavage (GL) to prevent vomiting and the establishment of enteral feeding empirically, but there was no study assessing the effect of GL for neonates with coffee-ground emesis. We designed a multicenter randomized controlled trial to evaluate the efficacy and safety of GL in neonates with coffee-ground emesis. Vigorous neonates with birth weight ranging from 2500 g to 3999 g and gestational age between 37w0d and 41w6d who presented with coffee-ground emesis on more than twice and diagnosed as false melena, were divided into two groups using computerized randomization. We defined feeding intolerance (FI) as (1) ≥2 vomiting episodes in 4h or ≥3 episodes in 24h and/or (2) feeding failure on at least two occasions because of retching or poor sucking. Primary outcome is percentage of infants who present FI within 24 hours from admission. We also assessed the residual volumes, number of vomiting episodes, percentage of weight reduction at postnatal day 4, rates of body weight gain at 1 month of age, and peak serum total bilirubin value before discharge. To our knowledge, this is the first study to evaluate the safety and efficacy of GL for neonates with coffee-ground emesis. This trial is registered at UMIN Clinical Trials Registry as UMIN000026483.

P1607Epigenetic modifications via histone acetylation by p300 are changed during the transition from cardiac hypertrophy to heart failure

Background

An intrinsic histone acetyltransferase (HAT), p300, is required for acetylation and the transcriptional activity of GATA4, as well as pathological left ventricular hypertrophy (LVH) and the development of heart failure (HF) in vivo. Recently, studies of histone modification have been performed within the flexible tails, such as H3K9 and H3K14. Although most previously studied histone modifications are within the flexible tails of histones, H3K122 is reportedly a novel site of the histone globular domain acetylated by p300, and its acetylation activates gene transcriptions by destabilizing histone-DNA binding and increasing the accessibility of transactional factors to DNA. However, little is known about the extent histone modifications directly affect LVH and HF.

Hypothesis

We hypothesized that p300 could induce epigenetic changes by acetylation of the globular domain as well as tail domain of histone during the development of LVH and HF.

Methods

First, to investigate whether the acetylation of H3K122 in the globular domain of histones as well as those of H3K9 and H3K14 in the tail domain of histones increased in cardiomyocytes hypertrophy, western blotting and chromatin-immunoprecipitation (ChIP) assays were performed using neonatal rat cultured cardiomyocytes with phenylephrine (PE) stimulus. Second, neonatal rat cultured cardiomyocytes were treated with p300 knockdown by siRNA or curcumin, a p300-specific HAT inhibitor. Third, to investigate the role of p300 HAT activity in histone acetylation in vivo, we utilized mice overexpressing p300 in the heart, which induced LVH. Final, to investigate whether these acetylation changes during the development of LVH and HF, in vivo ChIP assay was performed using hypertensive heart disease model of Dahl salt-sensitive rats.

Results

Western blotting indicated that treatment with PE increased the acetylation of H3K122 as well as those of H3K9 and H3K14 in cardiomyocytes hypertrophy. ChIP assay demonstrated that PE increased the recruitment of acetylated H3K122 and H3K9 onto ANF and BNP promoters containing the GATA element and peaks of acetylation of these domains were 4 hours after PE stimulation. Next, these acetylations were significantly inhibited by p300 knockdown by siRNA or treatment with curcumin. Conversely, in vivo ChIP assays in mice overexpressing p300 indicated that p300 overexpression increased recruitment of acetylated H3K122 and H3K9 onto ANF and BNP promoters containing the GATA element. Next, in hypertensive heart disease model of Dahl salt-sensitive rats, in vivo ChIP assays reviled that acetylation of H3K9 was increased around ANF and BNP promoters containing the GATA element at the LVH stage but that of H3K122 was increased at the HF stage.

Conclusion

Our data indicate that acetylation of H3K122 in globular domain of histones by p300 is the key event of the transition from LVH to HF.

Findings of amplitude-integrated electroencephalogram recordings and serum vitamin B6 metabolites in perinatal lethal hypophosphatasia during enzyme replacement therapy

Hypophosphatasia (HPP) is a rare disorder caused by low serum tissue non-specific alkaline phosphatase (ALP) activity due to hypomorphic mutations in the ALPL gene. HPP is characterized by defective bone mineralization. It frequently accompanies pyridoxine-responsive seizures. Because alkaline phosphatase change pyridoxal 5' phosphate (PLP) into pyridoxal (PL), which can cross the blood brain barrier and regulates inhibitory neurotransmitter gamma-aminobutyric acid. The female patient was born at a gestational age of 37 weeks 2 days. She presented severe respiratory disorder due to extreme thoracic hypoplasia. With the extremely low serum ALP value (14 IU/L), she was clinically diagnosed as HPP. The diagnosis was confirmed with genetic testing. On day1, the subclinical seizures were detected by aEEG. Together with enzyme replacement therapy by asfotase alfa, pyridoxine hydrochloride was administered, then the seizures were rapidly controlled. While confirming that there was no seizure by aEEG monitoring, pyridoxine hydrochloride was gradually discontinued after 1 month. Before administration of pyridoxine hydrochloride, PL was extremely low (4.7 nM) and PLP was increased (1083 nM). After the withdrawal, PL was increased to 84.9 nM only by enzyme replacement. Monitoring with aEEG enabled early intervention for pyridoxine responsive seizures. Confirming increased serum PL concentration is a prudent step in determining when to reduce or discontinue pyridoxine hydrochloride during enzyme replacement therapy.

Effects of pharmacological lesion of the nucleus retroambiguus region on the pharyngeal phase of swallowing

Pharyngeal swallowing is controlled by synaptic interactions within a swallowing central pattern generator (sw-CPG) that is composed of a dorsal and a ventral swallowing group (VSG). Here, we used electrical stimulation (10 s) of the superior laryngeal nerve (SLN; 20 Hz; pulse width: 100 μs) to explore the role of the VSG in an arterially-perfused brainstem preparation of rats. To investigate the effects of pharmacological lesion (local microinjection of an GABA(A)-R agonist) of the nucleus retroambiguus (NRA), a designated component of the VSG, we recorded phrenic (PNA) and vagal nerve (VNA) activities. Control SLN stimulation with stepwise increasing stimulus intensities (from 20 μA to 160 μA) elicited robust suppression of PNA and evoked sequential swallowing activity in the VNA. Lesioning of the NRA had no effect on the pattern of pharyngeal swallowing, but significantly increased the sensory gating of SLN inputs. We conclude that the NRA is not part of the VSG, but appears to have important roles for the central gating of swallowing.

Comparison of Clinical Characteristics of Human Metapneumovirus and Respiratory Syncytial Virus Infections in Hospitalized Young Children

Human metapneumovirus (HMPV) and respiratory syncytial virus (RSV) are the leading causes of acute respiratory tract infection in children, and clinical manifestations of these virus infections are considered similar. To investigate the differences in clinical characteristics between HMPV and RSV infections in young children, we prospectively enrolled children ＜ 3 years old who required hospitalization with acute respiratory tract infection due to HMPV or RSV at 10 hospitals in Japan. We enrolled 48 children with HMPV infection and 141 with RSV infection. Patients with HMPV infection were older than those with RSV infection. High-grade fever was more frequently observed in patients with HMPV infection, whereas no significant differences in respiratory symptoms were apparent. Abnormal serum lactate dehydrogenase values and consolidation shadows on chest X-ray were more frequently observed in patients with HMPV infection. During hospitalization, nasal mucus suction was more frequently required in patients with RSV infection. On the other hand, β2-adrenergic agonists, corticosteroids, and leukotriene receptor antagonists were more frequently used in patients with HMPV infection. These findings suggest that HMPV and RSV infections show similar respiratory symptoms, but HMPV infection is more likely to lead to the development of pneumonia, at least among hospitalized young children.

Search for K_{L}→π^{0}νν[over ¯] and K_{L}→π^{0}X^{0} Decays at the J-PARC KOTO Experiment

A search for the rare decay K_{L}→π^{0}νν[over ¯] was performed. With the data collected in 2015, corresponding to 2.2×10^{19} protons on target, a single event sensitivity of (1.30±0.01_{stat}±0.14_{syst})×10^{-9} was achieved and no candidate events were observed. We set an upper limit of 3.0×10^{-9} for the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level (C.L.), which improved the previous limit by almost an order of magnitude. An upper limit for K_{L}→π^{0}X^{0} was also set as 2.4×10^{-9} at the 90% C.L., where X^{0} is an invisible boson with a mass of 135  MeV/c^{2}.

Administration of Bone Marrow-Derived Mononuclear Cells Contributed to the Reduction of Hypoxic-Ischemic Brain Injury in Neonatal Rats

Background/Objective: Perinatal hypoxic-ischemia (HI) causes neonatal death and permanent neurological deficits. Cell therapy using various cell sources has been recently identified as a novel therapy for perinatal HI. Among the available types of cell sources, bone marrow-derived mononuclear cells (BMMNCs) have unique features for clinical application. For example, stem cells can be collected after admission, thus enabling us to perform autologous transplantation. This study aimed to investigate whether the administration of BMMNCs ameliorated HI brain injury in a neonatal rat model. Methods: Seven-day-old rats underwent left carotid artery ligation and were exposed to 8% oxygen for 60 min. BMMNCs were collected from the femurs and tibias of juvenile rats using the Ficoll-Hypaque technique and injected intravenously 24 h after the insult (1 × 10⁵ cells). Active caspase-3, as an apoptosis marker, and ED1, as an activated microglia/macrophage marker, were evaluated immunohistochemically 48 h after the insult (vehicle, n = 9; BMMNC, n = 10). Behavioral assessments using the rotarod treadmill, gait analysis, and active avoidance tests were initiated 3 weeks after the insult (sham, n = 9, vehicle, n = 8; BMMNC, n = 8). After these behavioral tests (6 weeks after the insult), we evaluated the volumes of their hippocampi, cortices, thalami, striata, and globus pallidus. Results: The mean cell densities of the sum of four parts that were positive for active caspase-3 significantly decreased in the BMMNC group (p < 0.05), whereas in the hippocampi, cortices, thalami, and striata cell densities decreased by 42, 60, 56, and 47%, respectively, although statistical significance was not attained. The number of ED1 positive cells for the sum of the four parts also significantly decreased in the BMMNC group compared to the vehicle group (p < 0.05), whereas in each of the four parts the decrease was 35, 39, 47, and 36%, respectively, although statistical significance was not attained. In gait analysis, the BMMNC normalized the contact area of the affected hind paw widened by HI. The volumes of the affected striata and globus pallidus were significantly larger in the BMMNC group than in the control group. Conclusion: These results indicated that the injection of BMMNCs ameliorated HI brain injury in a neonatal rat model.

Intravenous Administration of Bone Marrow-Derived Mesenchymal Stem Cell, but not Adipose Tissue-Derived Stem Cell, Ameliorated the Neonatal Hypoxic-Ischemic Brain Injury by Changing Cerebral Inflammatory State in Rat

Perinatal hypoxic-ischemic (HI) brain injury occurs in 1 in 1,000 live births and remains the main cause of neurological disability and death in term infants. Cytotherapy has recently emerged as a novel treatment for tissue injury. In particular, mesenchymal stem cells (MSCs) are thought to have therapeutic potential, but little is known about the differences according to their origin. In the current study, we investigated the therapeutic effects and safety of intravenous injection of allogeneic bone marrow-derived MSCs (BM-MSCs) and adipose-derived stem cells (ADSCs) in a rat model of HI brain injury. HI models were generated by ligating the left carotid artery of postnatal day 7 Wistar/ST rats and exposing them to 8% hypoxia for 60 min. Bone marrow and adipose tissue were harvested from adult green fluorescent protein transgenic Wistar rats, and cells were isolated and cultured to develop BM-MSCs and ADSCs. At passaging stages 2–3, 1 × 10⁵ cells were intravenously injected into the external right jugular vein of the HI rats at 4 or 24 h after hypoxia. Brain damage was evaluated by counting the number of cells positive for active caspase-3 in the entire dentate gyrus. Microglial isotypes and serum cytokines/chemokines were also evaluated. Distribution of each cell type after intravenous injection was investigated pathologically and bio-optically by ex vivo imaging (IVIS®) with a fluorescent lipophilic tracer DiR. The mortality rate was higher in the ADSC group compared to the BM-MSC group, in pups injected with cells 4 h after hypoxia. The number of active caspase-3-positive cells significantly decreased in the BM-MSC group, and the percentage of M1 microglia (a proinflammatory isotype) was also lower in the BM-MSC vs control group in the penumbra of the cortex. Moreover, BM-MSC administration increased anti-inflammatory cytokine and growth factor levels, while ADSCs did not. Each injected cell type was mainly distributed in the lungs and liver, but ADSCs remained in the lungs longer. Pathologically, pulmonary embolisms and diffuse alveolar hemorrhages were seen in the ADSC group. These results indicated that injection of allogeneic BM-MSCs ameliorated neonatal HI brain injury, whereas ADSCs induced severe lung hemorrhage and higher mortality.

Pyridoxal 5'-phosphate and related metabolites in hypophosphatasia: Effects of enzyme replacement therapy

OBJECTIVE

To investigate the utility of serum pyridoxal 5'-phosphate (PLP), pyridoxal (PL), and 4-pyridoxic acid (PA) as a diagnostic marker of hypophosphatasia (HPP) and an indicator of the effect of, and patient compliance with, enzyme replacement therapy (ERT), we measured PLP, PL, and PA concentrations in serum samples from HPP patients with and without ERT.

METHODS

Blood samples were collected from HPP patients and serum was frozen as soon as possible (mostly within one hour). PLP, PL, and PA concentrations were analyzed using high-performance liquid chromatography with fluorescence detection after pre-column derivatization by semicarbazide. We investigated which metabolites are associated with clinical phenotypes and how these metabolites change with ERT.

RESULTS

Serum samples from 20 HPP patients were analyzed. The PLP-to-PL ratio and PLP concentration were elevated in all HPP patients. They correlated negatively with serum alkaline phosphatase (ALP) activity and showed higher values in more severe phenotypes (perinatal severe and infantile HPP) compared with other phenotypes. PL concentration was reduced only in perinatal severe HPP. ERT reduced the PLP-to-PL ratio to mildly reduced or low-normal levels and the PLP concentration was reduced to normal or mildly elevated levels. Urine phosphoethanolamine (PEA) concentration did not return to normal levels with ERT in most patients.

CONCLUSIONS

The serum PLP-to-PL ratio is a better indicator of the effect of ERT for HPP than serum PLP and urine PEA concentrations, and a PLP-to-PL ratio of <4.0 is a good indicator of the effect of, and patient compliance with, ERT.

Magnetic resonance spectroscopy in preterm infants: association with neurodevelopmental outcomes

OBJECTIVE

To compare magnetic resonance spectroscopy (MRS) metabolite ratios in preterm infants at term-equivalent age with those in term infants and to evaluate the association between MRS metabolites and neurodevelopmental outcomes at 18 months corrected age in preterm infants.

DESIGN

We studied infants born at a gestational age <37 weeks and weighing <1500 g during 2009-2013 using MRS at term-equivalent age. Infants with major brain abnormalities were excluded. The ratios of N-acetylaspartate (NAA) to creatine (Cre), NAA to choline-containing compounds (Cho) and Cho to Cre in the frontal white matter and thalamus were measured using multivoxel point-resolved proton spectroscopy sequence. Neurodevelopmental outcomes were assessed at 18 months corrected age.

RESULTS

Thirty-three preterm infants and 16 term infants were enrolled in this study. Preterm infants with normal development at 18 months showed significantly lower NAA/Cho ratios in the frontal white matter than term infants. There were no differences in the Cre/Cho ratios between preterm and term infants. At 18 months corrected age, 9 preterm infants with a mild developmental delay showed significantly lower NAA/Cho ratios in the thalamus than 24 preterm infants with normal development.

CONCLUSIONS

Preterm infants at term-equivalent age showed reduced MRS metabolites (NAA/Cho) compared with term infants. Decreased NAA/Cho ratios in the thalamus were associated with neurodevelopmental delay at 18 months corrected age in preterm infants.

Reconstruction of Anal Function by Transposed Gracilis Muscle with Electral Stimulation: Rabbit Model

For the reconstruction of anal function for fecally incontinent patients, it could be practicable to transpose the gracilis muscle around the anal canal, with electrical stimulation to maintain contraction. It is necessary to keep continuous tonus, so tetanic contraction or “summation” would be essential for fecal continence, with a stimulation which permits prolonged contraction. Transposition of the gracilis muscle around the rectum was performed in thirteen Japanese white male rabbits. The muscles of the conditioning group (n=8) were stimulated at 10 Hz for 6 weeks before the procedure. By stimulation at 15 Hz, a low frequency to permit prolonged contraction, the neoanal pressure increased maximally to 134.2 ± 55.6 cmH2O (mean ± s.d.) in the conditioning group, and to 115.0 ± 37.1 cmH2O in the non-conditionin group (n=5) (N.S.). But, the basal pressure with stimulation rose 82.3 ± 12.4% (mean ± s.d.) of the increase in the conditioning group, while that of the non-conditioning group remained at resting pressure (p<0.001). The conditioning made it possible for the rabbit's gracilis muscle to create anal pressure with a sufficient rise in the basal pressure at a frequency permitting prolonged contraction.

Treatment with silver nitrate versus topical steroid treatment for umbilical granuloma: A non-inferiority randomized control trial

Objective

The aim of this prospective multicenter randomized controlled trial was to compare the efficacy of silver nitrate cauterization against that of topical steroid ointment in the treatment of neonatal umbilical granuloma.

Methods

An open-label, non-inferiority randomized controlled trial was conducted from January 2013 to January 2016. The primary endpoint for the silver nitrate cauterization and topical steroid ointment groups was the healing rate after 2 weeks of treatment, applying a non-inferiority margin of 10%. The healing rate was evaluated until completion of 3 weeks of treatment.

Results

Participants comprised 207 neonates with newly diagnosed umbilical granuloma, randomized to receive silver nitrate cauterization (n = 104) or topical steroid ointment (n = 103). Healing rates after 2 weeks of treatment were 87.5% (91/104) in the silver nitrate cauterization and 82% (82/100) in the topical steroid ointment group group. The difference between groups was -5.5% (95% confidence interval, -19.1%, 8.4%), indicating that the non-inferiority criterion was not met. After 3 weeks of treatment, the healing rate with topical steroid ointment treatment was almost identical to that of silver nitrate cauterization (94/104 [90.4%] vs. 91/100 [91.0%]; 0.6% [-13.2 to 14.3]). No major complications occurred in either group.

Conclusions

This study did not establish non-inferiority of topical steroid ointment treatment relative to silver nitrate cauterization, presumably due to lower healing rates than expected leading to an underpowered trial. However, considering that silver nitrate cauterization carries a distinct risk of chemical burns and that the overall efficacy of topical steroid ointment treatment is similar to that of silver nitrate cauterization, topical steroid ointment might be considered as a good alternative in the treatment of neonatal umbilical granuloma due to its safety and simplicity. To clarify non-inferiority, a larger study is needed.

Dedifferentiated Fat Cells as a Novel Source for Cell Therapy to Target Neonatal Hypoxic-Ischemic Encephalopathy

Neonatal hypoxic-ischemic (HI) encephalopathy (HIE) remains a major cause of mortality and persistent neurological disabilities in affected individuals. At present, hypothermia is considered to be the only applicable treatment option, although growing evidence suggests that cell-based therapy might achieve better outcomes. Dedifferentiated fat (DFAT) cells are derived from mature adipocytes via a dedifferentiation strategy called ceiling culture. Their abundance and ready availability might make them an ideal therapeutic tool for the treatment of HIE. In the present study, we aimed to determine whether the outcome of HIE can be improved by DFAT cell treatment. HI injury was achieved by ligating the left common carotid artery in 7-day-old rat pups, followed by 1-h exposure to 8% O2. Subsequently, the severity of damage was assessed by diffusion-weighted magnetic resonance imaging to assign animals to equivalent groups. 24 h after hypoxia, DFAT cells were injected at 105 cells/pup into the right external jugular vein. To evaluate brain damage in the acute phase, a group of animals was sacrificed 48 h after the insult, and paraffin sections of the brain were stained to assess several acute injury markers. In the chronic phase, the behavioral outcome was measured by performing a series of behavioral tests. From the 24th day of age, the sensorimotor function was examined by evaluating the initial forepaw placement on a cylinder wall and the latency to falling from a rotarod treadmill. The cognitive function was tested with the novel object recognition (NOR) test. In vitro conditioned medium (CM) prepared from cultured DFAT cells was added at various concentrations to neuronal cell cultures, which were then exposed to oxygen-glucose deprivation (OGD). The number of cells that stained positive for the apoptosis marker active caspase-3 decreased by 73 and 52% in the hippocampus and temporal cortex areas of the brain, respectively, in the DFAT-treated pups. Similarly, the numbers of ED-1-positive cells (activated microglia) decreased by 66 and 44%, respectively, in the same areas in the DFAT-treated group. The number of cells positive for the oxidative stress marker 4-hydroxyl-2-nonenal decreased by 68 and 50% in the hippocampus and the parietal cortex areas, respectively, in the DFAT-treated group. The HI insult led to a motor deficit according to the rotarod treadmill and cylinder test, where it significantly affected the vehicle group, whereas no difference was confirmed between the DFAT and sham groups. However, the NOR test indicated no significant differences between any of the groups. DFAT treatment did not reduce the infarct volume, which was confirmed immunohistochemically. According to in vitro experiments, the cell death rates in the DFAT-CM-treated cells were significantly lower than those in the controls when DFAT-CM was added 48 h prior to OGD. The treatment effect of adding DFAT-CM 24 h prior to OGD was also significant. Our results indicate that intravenous injection with DFAT cells is effective for ameliorating HI brain injury, possibly via paracrine effects.

Quantitative Analyses of Hepatic OATP-Mediated Interactions Between Statins and Inhibitors Using PBPK Modeling With a Parameter Optimization Method

This study aimed to construct a widely applicable method for quantitative analyses of drug-drug interactions (DDIs) caused by the inhibition of hepatic organic anion transporting polypeptides (OATPs) using physiologically based pharmacokinetic (PBPK) modeling. Models were constructed for pitavastatin, fluvastatin, and pravastatin as substrates and cyclosporin A (CsA) and rifampicin (RIF) as inhibitors, where enterohepatic circulations (EHC) of statins were incorporated. By fitting to clinical data, parameters that described absorption, hepatic elimination, and EHC processes were optimized, and the extent of these DDIs was explained satisfactorily. Similar in vivo inhibition constant (K_i ) values of each inhibitor against OATPs were obtained, regardless of the substrates. Estimated K_i values of CsA were comparable to reported in vitro values with the preincubation of CsA, while those of RIF were smaller than reported in vitro values (coincubation). In conclusion, this study proposes a method to optimize in vivo PBPK parameters in hepatic uptake transporter-mediated DDIs.

Gli2 protein expression level is a feasible marker of ligand-dependent hedgehog activation in pancreatic neoplasms

The hedgehog pathway is known to promote proliferation of pancreatic ductal adenocarcinoma (PDA) and has been shown to restrain tumor progression. To understand how hedgehog causes these effects, we sought to carefully examine protein expression of hedgehog signaling components during different tumor stages. Genetically engineered mice, Pdx1-Cre;LSL-KrasG12D and Pdx1-Cre;LSL-KrasG12D;p53lox/+, were utilized to model distinct phases of tumorigenesis, pancreatic intraepithelial neoplasm (PanIN) and PDA. Human pancreatic specimens of intraductal papillary mucinous neoplasm (IPMN) and PDA were also employed. PanIN and IPMN lesions highly express Sonic Hedgehog, at a level that is slightly higher than that observed in PDA. GLI2 protein is also expressed in both PanIN/IPMN and PDA. Although there was no difference in the nuclear staining, the cytoplasmic GLI2 level in PDA was modest in comparison to that in PanIN/IPMN. Hedgehog interacting protein was strongly expressed in the precursors, whereas the level in PDA was significantly attenuated. There were no differences in expression of Patched1 at early and late stages. Finally, a strong correlation between Sonic Hedgehog and GLI2 staining was found in both human and murine pancreatic tumors. The results indicate that the GLI2 protein level could serve as a feasible marker of ligand-dependent hedgehog activation in pancreatic neoplasms.

Organ Impairment-Drug-Drug Interaction Database: A Tool for Evaluating the Impact of Renal or Hepatic Impairment and Pharmacologic Inhibition on the Systemic Exposure of Drugs

The organ impairment and drug–drug interaction (OI-DDI) database is the first rigorously assembled database of pharmacokinetic drug exposure data from publicly available renal and hepatic impairment studies presented together with the maximum change in drug exposure from drug interaction inhibition studies. The database was used to conduct a systematic comparison of the effect of renal/hepatic impairment and pharmacologic inhibition on drug exposure. Additional applications are feasible with the public availability of this database.

Thorough debridement and immediate primary wound closure for animal bite injuries of the upper limbs

PURPOSE

Animal bite injuries are often encountered in daily practice. In particular, these injuries of the upper limbs can result in severe functional impairment. We have performed early debridement of contaminated tissue and primary closure for these injuries.

METHODS

The subjects consisted of 15 patients (6 males and 9 females) aged 1-91 years (mean 53.6 years) who visited our hospital due to animal bite injuries (dog in 9 patients, cat in 6). The bite site was the forearm in 5 patients and the hand in 10. In the operating room, contaminated tissue was removed, and primary wound closure was performed after irrigation.

RESULTS

The bite penetrated to the muscle layer in 6 patients, tendon sheath in 5, joint in 1, bone in 1, and involved only the subcutaneous tissue in 3 patients. The mean period until the completion of wound treatment was 19.8 ± 8.4 days. As complications, numbness of finger, metaphalangeal joint contracture and superficial radial nerve injury were observed in each one case. In a patient with bite injury of the palmar and dorsal sides of the thumb reaching the bone, additional debridement was necessary. At the final observation, the visual analog scale was 1.2 ± 1.4, and the Quick Disabilities of the Arm, Shoulder, and Hand score was 9.7 ± 12.2.

CONCLUSIONS

Debridement to achieve wound closure is indispensable in patients with animal bite injuries of the upper limbs. The results of our study suggest that thorough debridement allows primary closure, even for animal bite injuries.

Administration of umbilical cord blood cells transiently decreased hypoxic-ischemic brain injury in neonatal rats

This study aimed to investigate whether the administration of mononuclear cells derived from human umbilical cord blood cells (UCBCs) could ameliorate hypoxic-ischemic brain injury in a neonatal rat model. The left carotid arteries of 7-day-old rats were ligated, and the rats were then exposed to 8% oxygen for 60 min. Mononuclear cells derived from UCBCs using the Ficoll-Hypaque technique were injected intraperitoneally 6 h after the insult (1.0 × 10(7) cells). Twenty-four hours after the insult, the number of cells positive for the oxidative stress markers 4-hydroxy-2-nonenal and nitrotyrosine, in the dentate gyrus of the hippocampus in the UCBC-treated group, decreased by 36 and 42%, respectively, compared with those in the control group. In addition, the number of cells positive for the apoptosis markers active caspase-3 and apoptosis-inducing factor decreased by 53 and 58%, respectively. The number of activated microglia (ED1-positive cells) was 51% lower in the UCBC group compared with the control group. In a gait analysis performed 2 weeks after the insult, there were no significant differences among the sham-operated, control and UCBC groups. An active avoidance test using a shuttle box the following week also revealed no significant differences among the groups. Neither the volumes of the hippocampi, corpus callosum and cortices nor the numbers of neurons in the hippocampus were different between the UCBC and control groups. In summary, a single intraperitoneal injection of UCBC-derived mononuclear cells 6 h after an ischemic insult was associated with a transient reduction in numbers of apoptosis and oxidative stress marker-positive cells, but it did not induce long-term morphological or functional protection. Repeated administration or a combination treatment may be required to achieve sustained protection.

Severe Re-expansion Pulmonary Edema Induced by One-Lung Ventilation

We present 2 cases of severe re-expansion pulmonary edema (RPE) after one-lung ventilation (OLV) for thoracic surgery. A 32-y-old woman with multiple lung metastases developed severe RPE after OLV during lung resection surgery. A 37-y-old man with infective endocarditis also developed severe RPE after OLV for mitral valve plasty with minimally invasive cardiac surgery. In both cases, results of a preoperative pulmonary function test and oxygenation were almost normal, and pleural effusion or pulmonary congestion was not detected in preoperative computed tomography; however, there was a possibility that subclinical lung injury existed before surgery. The levels of interleukin-8 and monocyte chemotactic protein-1, which are thought to play important roles in the development of lung injury, in bronchial secretions were extremely high after the onset of RPE. These results suggest that the pathogenesis of RPE shares, at least in part, a common pathophysiology of acute lung injury.

Paradoxical downward seizure pattern on amplitude-integrated electroencephalogram

The use of amplitude-integrated electroencephalography (aEEG) to assess brain function and detect seizures has been increasing worldwide. Results from previous studies have demonstrated that seizure patterns can be recognized as transient rises on aEEG traces. We report here a case of an infant with neonatal seizures that showed paradoxical transient drops on aEEG traces. The ictal EEG showed initial low-amplitude fast rhythmic activity followed by epileptic recruiting rhythms and high-voltage slow waves. Therefore, downward patterns on aEEG traces should be recognized as suspected seizure patterns.

Kinetic Interpretation of the Importance of OATP1B3 and MRP2 in Docetaxel-Induced Hematopoietic Toxicity

Neutropenia is a lethal dose-limiting toxicity of docetaxel. Our previous report indicated that the prevalence of severe docetaxel-induced neutropenia is significantly associated with genetic polymorphisms in solute carrier organic anion transporter 1B3 (SLCO1B3) (encoding organic anion–transporting polypeptide 1B3 (OATP1B3)) and ATP-binding cassette subfamily C2 (ABCC2) (encoding multidrug-resistant–associated protein 2 (MRP2)). Therefore, we investigated their significance in docetaxel-induced neutropenia. In vitro experiments suggested their possible involvement in the hepatic uptake of docetaxel and its efflux from bone marrow cells. To further characterize a quantitative impact of OATP1B3 and MRP2 on neutropenia, we used an in silico simulation of the neutrophil count in docetaxel-treated subjects with functional changes in OATP1B3 and MRP2 in a pharmacokinetic/pharmacodynamic model. The clinically reported odds ratios for docetaxel-induced neutropenia risk were explained by the decreased function of OATP1B3 and MRP2 to 41 and 32%, respectively. These results suggest that reduced activities of OATP1B3 and MRP2 associated with systemic exposure and local accumulation in bone marrow cells, respectively, account for the docetaxel-induced neutropenia observed clinically.

Interactions between lens epithelial and fiber cells reveal an intrinsic self-assembly mechanism

How tissues and organs develop and maintain their characteristic three-dimensional cellular architecture is often a poorly understood part of their developmental program; yet, as is clearly the case for the eye lens, precise regulation of these features can be critical for function. During lens morphogenesis cells become organized into a polarized, spheroidal structure with a monolayer of epithelial cells overlying the apical tips of elongated fiber cells. Epithelial cells proliferate and progeny that shift below the lens equator differentiate into new fibers that are progressively added to the fiber mass. It is now known that FGF induces epithelial to fiber differentiation; however, it is not fully understood how these two forms of cells assemble into their characteristic polarized arrangement. Here we show that in FGF-treated epithelial explants, elongating fibers become polarized/oriented towards islands of epithelial cells and mimic their polarized arrangement in vivo. Epithelial explants secrete Wnt5 into the culture medium and we show that Wnt5 can promote directed behavior of lens cells. We also show that these explants replicate aspects of the Notch/Jagged signaling activity that has been shown to regulate proliferation of epithelial cells in vivo. Thus, our in vitro study identifies a novel mechanism, intrinsic to the two forms of lens cells, that facilitates self-assembly into the polarized arrangement characteristic of the lens in vivo. In this way the lens, with its relatively simple cellular composition, serves as a useful model to highlight the importance of such intrinsic self-assembly mechanisms in tissue developmental and regenerative processes.

A new objective histological scale for studying human photoaged skin

BACKGROUND

A quantitative understanding of the histological alteration of the skin is important for assessing the severity of photoaging.

METHODS

We performed Elastica-van Gieson staining and immunohistochemistry for decorin on 34 facial skin sections. We evaluated the alteration of collagen fibers and decorin (a modulator for collagen fibrillogenesis), according to the 5 grades of morphological change in elastic fibers that was established by Kligman (1969). The objectivity of a stage (Stages I-VI), which was established in this study, was evaluated using weighted kappa statistical analysis based on the degree of agreement in stage determination by 11 observers using a blind procedure. Correlation between the crow's-feet-area wrinkles grades of another 26 women and stages was also analyzed.

RESULTS

The initial alteration of elastic fibers was observed in the deep dermis. Decorin was not detected in very severely altered skin. Based on the combination of changes in the elastic fibers, collagenic fibers, and decorin, skin tissues were categorized into 6 stages according to severity. The statistical analysis showed almost perfect agreement between observers. Significant positive correlation between stages and wrinkle scores was found.

CONCLUSIONS

We propose a new objective histological scale that is useful for assessing the severity of photoaging.