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Hypoxic exercise, which can induce arterial and tissue deoxygenation, promotes physiological adaptations. However, reduced oxygen availability can lower the absolute training intensity (i.e., mechanical stress). Adding normoxic recovery to sprint interval exercise (SIE) is one potential approach to strike a balance between providing a hypoxic stimulus and maintaining the absolute training intensity. However, the effects of adding normoxic recovery to SIE on performance and physiological responses are uncertain. We tested the hypothesis that hypoxic SIE with normoxic recovery enhances arterial deoxygenation and muscle deoxygenation levels without impeding performance compared to an entirely normoxic condition. On separate days, seven male sprinters performed 4 × 30‐s 'all‐out' cycle sprints with 4.5‐min recovery with hypoxic exposure (FiO2: 12.7%O2) applied continuously (hypoxia, HYP), intermittently during sprint periods only (intermittent, INT), or not at all (normoxia, NOR). Power output, oxygen saturation, muscle oxygenation, surface electromyography (EMG) activity, heart rate, blood lactate concentration, and ratings of perceived exertion were measured. The total work significantly decreased in HYP than NOR (p < 0.05) and INT (p < 0.01). The aTrterial oxygen saturation was lower during HYP than NOR (∼86% vs. ∼97%; p < 0.001), while lower values were also obtained for INT than NOR during sprint periods (∼85% vs. ∼97%; p < 0.001) but not during recovery periods (∼96% vs. ∼97%). The heart rate differed (p < 0.05) between conditions (NOR: ∼164 bpm; INT: ∼160 bpm; HYP: ∼156 bpm). No other variables demonstrated significant differences between conditions. Adding hypoxia during exercise while recovering in normoxia did not compromise exercise capacity during SIE, despite inducing larger arterial deoxygenation levels compared to normoxia. Highlights: Utilizing severe hypoxia during exercise and normoxia during recovery induces a substantial hypoxic stimulus while safeguarding mechanical performance in sprinters.This approach maintains neuromuscular, metabolic, and perceptual parameters without any detrimental effects, ensuring athletes can perform at their best.Alternating hypoxia and normoxia during active and passive phases shows potential for optimizing hypoxic training, striking an ideal balance between the hypoxic stimulus and training intensity and load. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigated the anti-glycolytic effects of evofosfamide (EVO) on three canine glioma (GL)-derived cell lines with activated hypoxia-inducible factor 1α (HIF-1α). Our clinical data showed that glycolytic activity was correlated with poorer outcomes in dogs with spontaneous GL. Our in vitro studies showed that EVO inhibited glycolytic metabolism by targeting HIF-1α-positive cells under hypoxic culture conditions, resulting in the suppression of cellular ATP production. Our in vivo studies showed that EVO significantly decreased tumor development compared to controls or temozolo-mid in orthotopic murine GL models. A metabolic analysis demonstrated that EVO suppressed glycolytic activity by eliminating HIF-1α-positive cells. Our findings suggest that EVO may improve cancer metabolism and restore the microenvironment for both canine and human GL. The transcription factor hypoxia-inducible factor 1α (HIF-1α) drives metabolic reprogramming in gliomas (GLs) under hypoxic conditions, promoting glycolysis for tumor development. Evofosfamide (EVO) releases a DNA-alkylating agent within hypoxic regions, indicating that it may serve as a hypoxia-targeted therapy. The aim of this study was to investigate the glycolytic metabolism and antitumor effects of EVO in a canine GL model. Our clinical data showed that overall survival was significantly decreased in GL dog patients with higher HIF-1α expression compared to that of those with lower HIF-1α expression, and there was a positive correlation between HIF-1α and pyruvate dehydrogenase kinase 1 (PDK1) expression, suggesting that glycolytic activity under hypoxia conditions may contribute to poor outcomes in canine GL. Our glycolysis assay tests showed that the glycolytic ATP level was higher than the mitochondrial ATP level in three types of canine GL cell lines by activating the HIF-1 signal pathway under hypoxia conditions, resulting in an overall increase in total cellular ATP production. However, treatment with EVO inhibited the glycolytic ATP level in the GL cell lines under hypoxia conditions by targeting HIF-1α-positive cells, leading to decrease in total cellular ATP production. Our in vivo tests showed that EVO significantly reduced tumor development compared to controls and temozolomide in murine GL models. A metabolic analysis demonstrated that EVO effectively suppressed glycolytic metabolism by eliminating HIF-1α-positive cells, suggesting that it may restore metabolism in canine GLs. The evidence presented here supports the favorable preclinical evaluation of EVO as a potential improvement in cancer metabolism. [ABSTRACT FROM AUTHOR]

Background: This study aimed to understand whether the one-time chair stand test (CS-1) is useful for predicting the severity of coronavirus disease (COVID-19) in 101 patients admitted to the hospital with acute respiratory failure. Methods: This single-centered, prospective observational cohort study enrolled 101 critically ill adult patients hospitalized with COVID-19 who underwent the CS-1 as a dynamic evaluation tool in clinical practice between late April 2020 and October 2021. Data on demographic characteristics, symptoms, laboratory values, computed tomography findings, and clinical course after admission were collected. Furthermore, the data was compared, and the association between the intubation and non-intubation groups was determined. We also calculated the cutoff point, area under the curve (AUC), and 95% confidence interval (CI) of the change in oxygen saturation (ΔSpO2) during the CS-1. Results: Thirty-three out of 101 patients (33%) were intubated during hospitalization. There was no significant difference in the resting SpO2 (93.3% versus 95.2%, P = 0.22), but there was a significant difference in ΔSpO2 during the CS-1 between the intubation and non-intubation groups (10.8% versus 5.5%, P < 0.01). In addition, there was a significant correlation between hospitalization and ΔSpO2 during the CS-1 (ρ = 0.60, P < 0.01). The generated cutoff point was calculated as 9.5% (AUC = 0.94, 95% CI = 0.88–1.00). Conclusion: For COVID-19 patients with acute respiratory failure, the CS-1 performed on admission was useful for predicting the severity of COVID-19. Furthermore, the CS-1 can be utilized as a remote and simple evaluation parameter. Thus, it could have potential clinical applications in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: The 6-min walk test (6MWT) is a common assessment of exercise-induced hypoxemia and exercise capacity used in patients with chronic fibrosing interstitial pneumonia (CFIP). However, whether the dynamic changes in SpO2 and heart rate during the 6MWT are associated with mortality in patients with CFIP has been undefined. METHODS: This retrospective study enrolled 63 subjects with mild to severe CFIP who underwent the 6MWT. Subjects with CFIP were divided into 2 groups according to disease severity: mild, diffusing capacity of the lungs for carbon monoxide percentage predicted (%DLCO) > 55% and %FVC > 75%; and severe, %DLCO ≤ 55% and/or %FVC ≤ 75%. This study aimed to evaluate dynamic changes in the 6MWT including 6-min walk distance, change in SpO2(ΔSpO2), SpO2 reduction time, SpO2 recovery time, change in heart rate (Δ heart rate), heart rate acceleration time, slope of heart rate acceleration, heart rate recovery at 1 min of rest after the 6MWT (HR-recovery), and dyspnea on exertion that are reflected by static pulmonary function and are related to exacerbation of CFIP and mortality. RESULTS: Compared with subjects with mild CFIP, subjects with severe CFIP had significantly larger ΔSpO2 and longer SpO2 reduction time and recovery time. The slope of heart rate, heart rate immediately after the 6MWT, and HR-recovery were lower in subjects with severe CFIP than in those with mild CFIP. In multiple regression analysis, percent vital capacity was significantly associated with SpO2 reduction time, and %DLCO was significantly associated with ΔSpO2 and SpO2 recovery time. Subjects with ΔSpO2 of > 10% and SpO2 recovery time of > 79 s had a significantly higher risk for exacerbation and mortality. CONCLUSIONS: Dynamic changes in SpO and heart rate during the 6MWT were associated with risk for exacerbation and mortality in subjects with CFIP. Impaired dynamic response of SpO2 could reflect likelihood of exacerbation and increased mortality in CFIP. [ABSTRACT FROM AUTHOR]

In Mikawa Bay, where hypoxia occurs in the bottom layer during summer, six shipboard observations were conducted from the mouth to the head of the bay from May to August 2014 to investigate the spatiotemporal variation in the bottom layer oxygen consumption rate (OCR). The OCR was determined from the dark incubation of sample waters using an optical oxygen sensor, which showed a range of 5.7–38.3 mmol m−3 days−1. A high OCR was observed at the inner-most station, where higher concentrations of nutrients and chlorophyll a (Chl a) than at the other stations were found, and bottom hypoxic water appeared during the observation period after late June. These OCRs can deplete the oxygen dissolved in water within a week. The OCR showed a highly significant positive correlation with particulate organic carbon concentrations in the bottom water. Considering the relatively low carbon-to-nitrogen mole ratio (~ 6.4–7.6) and high carbon isotope ratio (between approximately − 20.2 and − 18.8‰) of particulate organic matter at the stations, the supply of fresh organic matter produced in the bay as opposed to the land may have affected the OCR by acting as a substrate for microbial aerobic respiration. High temporal resolution data from two automated observation buoys near the bay mouth and the inner area captured increases in Chl a at both sites in response to typhoon events, along with the subsequent appearance of bottom hypoxic water at the inner site and its expansion at the mouth. This supports our hypothesis that enhanced organic matter production due to nutrient input to the surface layer through vertical mixing would increase the bottom OCR, resulting in hypoxia. The apparent oxygen decline in the bottom layer from the buoy data was consistent with incubation-based OCRs during the observation period. Therefore, it is essential to model the OCR in numerical simulations of hypoxia, to which the variability characteristics that we revealed made significant contributions. [ABSTRACT FROM AUTHOR]

Dissolved organic carbon (DOC) comprises nearly half of the riverine organic carbon flux into oceans. Although riverine DOC is involved in numerous important ecosystem functions, excessive labile DOC inputs from rivers may contribute to hypoxia in coastal systems. Furthermore, many aspects of the contribution of riverine DOC to hypoxia are unknown. The natural carbon stable isotope ratio (δ13C) in organic matter can be used to identify sources of organic carbon in coastal oceans. In this study, we analyzed the concentrations and δ13C values of DOC in the bottom layer of the northern Ariake Sea, Japan, in which hypoxic water develops during summer. Additionally, we compared the δ13C values of DOC at the beginning and end of an incubation experiment to determine the contribution of riverine DOC decomposition to hypoxia. The results of this study indicate that the bottom DOC concentration is influenced by both phytoplankton and river water, with the former likely having a stronger impact in the northwestern Ariake Sea in summer. Nevertheless, we also found major contributions (~ 49.7%) of DOC decomposition to total organic carbon decomposition at some stations. The initial δ13C value of DOC ranged from − 24.0 to − 22.2‰, and the DOC δ13C increased (from + 0.3 to + 0.8‰) in three of the five incubation bottles after incubation. This might be caused by selective decomposition of 13C-depleted organic matter. The decomposed DOC in those bottles must be mainly derived from terrestrial sources. This result implies that riverine DOC decomposition contributes to hypoxia formation in the bottom layer of the northern Ariake Sea. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to explore the global research status, hot topics, and future prospects in the field of the hypoxia inducible factor prolyl hydroxylase inhibitor (HIF-PHI) by bibliometric analysis. Methods: The literatures about HIF-PHI were downloaded from the Web of Science Core Collection and Pubmed database from inceptions to January.10th. 2022. The VOSviewer 1.6.18 was used to explore the bibliometric networks and research priorities of HIF-PHI. Results: A total of 409 papers about HIF-PHI were included, involving 1,674 authors from 548 institutions in 43 countries. The number of HIF-PHI literatures showed an upward trend, with steady growth from 2016 to 2020 and rapid growth in 2021. Tadao Akizawa, Masaomi Nangaku and Alexander R Cobitz published the most literatures. The United States, Japan and China contributed the most publications. The three most contributed institutions are Astellas Pharma Inc., the Showa University and Glaxosmithkline. Therapeutic Apheresis and Dialysis, American Journal of Nephrology and Clinical Pharmacology in Drug Development are the most productive journals. The main hot topics of HIF-PHI field are anemia, chronic kidney disease, hif-phi, epoetin and roxadustat. Conclusion: The United States and Japan are dominant in the field of HIF-PHI research. The discovery and clinical application of HIF-PHI is a great boon for patients with renal anemia. However, due to the short clinical application time of HIF-PHI, and its long-term efficacy and safety still need time to prove. In addition, more cooperation should be carried out between European and American countries and Asian countries to better prove the clinical value of HIF-PHI. [ABSTRACT FROM AUTHOR]

Silent hypoxia (SH) is common in patients with coronavirus disease (COVID-19) in Japan and other countries. Early identification of SH is important as more treatment options for COVID-19 have become available. This study aimed to identify predictors of SH using a nationwide COVID-19 registry of hospitalized patients. Adult patients who were admitted to hospital with COVID-19 between January 2020 and June 2021 and who were hypoxic on admission (SpO 2 : 70–93%), not transferred from another facility, and who did not have disturbance of consciousness, confusion, or dementia, were included. SH was defined as hypoxia in the absence of shortness of breath/dyspnea upon admission. Predictors of SH were identified using univariable and multivariable logistic regression. The study included 1904 patients, of whom 990 (52%) satisfied the criteria for SH. Compared to patients without SH, patients with SH were older, more likely to be female, and had a slightly higher SpO 2 on admission. Compared to patients without SH, patients with SH had a lower prevalence of chronic lung disease (CLD) other than chronic obstructive pulmonary disease (COPD), asthma, and obesity. Multivariable analysis revealed that the independent predictors of SH were older age, a shorter interval from symptom onset to admission, higher SpO 2 , and an absence of CLD or COPD. The absence of underlying lung disease and older age were important predictors of SH. The results of this study, which is the largest such study reported to date in Japan, may help clarify the mechanism of SH. [ABSTRACT FROM AUTHOR]

CDC37 is a key determinant of client kinase recruitment to the HSP90 chaperoning system. We hypothesized that kinase-specific dependency on CDC37 alters the efficacy of targeted therapies for metastatic colorectal cancer (mCRC). Two independent mCRC cohorts were analyzed to compare the survival outcomes between CDC37 -high and CDC37 -low patients (stratified by the median cutoff values): the CALGB/SWOG 80405 trial (226 and 207 patients receiving first-line bevacizumab- and cetuximab-containing chemotherapies, respectively) and Japanese retrospective (50 refractory patients receiving regorafenib) cohorts. A dataset of specimens submitted to a commercial CLIA-certified laboratory was utilized to characterize molecular profiles of CDC37 -high (top quartile, N = 5055) and CDC37 -low (bottom quartile, N = 5055) CRCs. In the bevacizumab-treated group, CDC37 -high patients showed significantly better progression-free survival (PFS) (median 13.3 vs 9.6 months, hazard ratio [HR] 0.59, 95% confidence interval [CI] 0.44–0.79, p < 0.01) than CDC37 -low patients. In the cetuximab-treated group, CDC37 -high and CDC37 -low patients had similar outcomes. In the regorafenib-treated group, CDC37 -high patients showed significantly better overall survival (median 11.3 vs 6.0 months, HR 0.24, 95% CI 0.11–0.54, p < 0.01) and PFS (median 3.5 vs 1.9 months, HR 0.51, 95% CI 0.28–0.94, p = 0.03). Comprehensive molecular profiling revealed that CDC37 -high CRCs were associated with higher VEGFA , FLT1 , and KDR expressions and activated hypoxia signature. CDC37 -high mCRC patients derived more benefit from anti-VEGF therapies, including bevacizumab and regorafenib, but not from cetuximab. Molecular profiles suggested that such tumors were dependent on angiogenesis-relating pathways. • We explored a novel predictive biomarker CDC37 expression in treatment of mCRC. • CDC37 -highly expressed mCRC derived more benefit from bevacizumab and regorafenib. • No significant associations between CDC37 expression and cetuximab efficacy were observed. • The angiogenesis-relating pathways were activated in CDC37 -highly expressed CRC. [ABSTRACT FROM AUTHOR]

Declining oxygen concentrations in aquatic habitats represent extreme conditions that threaten benthic life. Hypoxia has recently become an important research topic, as areas affected by these phenomena are spreading globally. Omura Bay is one of the most highly enclosed seas in Japan, and severely hypoxic conditions occur at the bottom every summer. We conducted a preliminary study in the center of the bay to evaluate how seasonal hypoxia affects the abundance and community composition of benthic meiofauna, with particular reference to copepods. The copepod densities and their nauplii differed significantly among seasonal categories (before, during, and after hypoxia). Furthermore, the degree of the seasonal decline in copepods during hypoxia seemed much more severe than that in nematodes, the most abundant meiofauna. The assemblages of adult copepods had the simplest composition during hypoxia, when harpacticoid copepods in the family Cletodidae, which have smaller and slender bodies, occurred at significantly higher frequencies (a contribution of 84% to the mean similarity among seasons). After hypoxia, the relative abundance of copepods in the families Ectinosomatidae and Longipediidae increased, which may likely be attributed to their higher swimming abilities and rapid recruitment via specific planktonic nauplius stages, respectively. High frequencies of copepods in the Cletodidae family have also been observed under hypoxic conditions in the Mediterranean Sea, suggesting that similar processes affect benthic copepod communities, which work to the advantage of cletodid species with small and slender forms in the subtidal sediment bottom under severe hypoxia in Omura Bay and other regions. [ABSTRACT FROM AUTHOR]

There are few reports on reticulocyte count during the early postnatal period, and its clinical significance is not well understood. To examine the relationships between neonatal reticulocyte count and other perinatal variables. We conducted a retrospective cohort study of neonatal infants who were admitted to the neonatal intensive care unit (NICU) of Ohta Nishinouchi Hospital, Japan, between April 1, 2016 and July 31, 2019. All blood samples were collected within 3 h after admission. Four hundred and twenty-eight infants were included, of whom 317 (74.1%) were preterm and 111 (25.9%) were term. Two hundred and ninety-nine infants (69.9%) were born by cesarean section. The median reticulocyte counts (‰) for all gestational ages (GAs) were as follows: 24–25 wks (n = 11), 124.1 (range: 106.3 to 148.6); 26–27 wks (n = 25), 111.1 (range: 55.5 to 144.3); 28–30 wks (n = 52), 81.9 (range: 35.6 to 131.5); 31–33 wks (n = 86), 71.6 (range: 28.3 to 116.6); 34–36 wks (n = 143); 59.6 (range: 30.2 to 110.9); and 37–41 wks (n = 111), 43.2 (range: 21.9 to 69.2). There were significant relationships between the neonatal reticulocyte count and gender [ p < 0.01, odds ratio (OR), 0.37; 95% confidence interval (CI), 0.21 to 0.64], GA (p < 0.01, OR, 0.92; 95% CI, 0.90 to 0.93), delivery type (p = 0.03, OR, 0.51; 95% CI, 0.28 to 0.95), maternal haemoglobin before delivery (p < 0.01, OR, 0.74; 95% CI, 0.60 to 0.91), tracheal intubation at resuscitation (p = 0.04, OR, 2.75; 95% CI, 1.04 to 7.32) and mean platelet volume (p < 0.01, OR, 0.51; 95% CI, 0.35 to 0.74). A higher neonatal reticulocyte count in NICU infants may be one of the physiological responses to a more rapid environmental change during the early postnatal period. [ABSTRACT FROM AUTHOR]

Physical processes associated with hypoxia events in a shallow lake, Lake Kasumigaura, Japan, are investigated with long-term mooring observations at the middle of the lake basin. Results show that strong stratification during the summer suppresses vertical mixing resulting in hypoxia in the bottom boundary layer. The dissolved oxygen decreases due to the limited oxygen supply under strongly stratified conditions. The intensity of the stratification is controlled by the ratio between surface wind stress and the surface incoming buoyancy flux. The Monin–Obukhov length scale explains the stratification and shows good agreement with the Froude number and Wedderburn number. The stratification is also enhanced by the heat flux towards the sediments, reaching O (100) W m−2, during the summer season. In addition to field observations, this study conducted numerical simulations to further investigate mixing structure. Results from numerical simulations indicate that the bottom sediment heat flux significantly contributes to mixing and stratification in the lake. This study suggests that mixing processes associated with winds and heat flux at surface and bottom sediments are the key to understanding hypoxia events in Lake Kasumigaura. [ABSTRACT FROM AUTHOR]

Objective: The goal of this study was to investigate the prognosis of infants with neonatal respiratory inhibition syndrome (NRIS).Methods: Infants with a gestational age of at least 36 weeks and a birth weight of at least 2000 g who were born at Nara Prefecture General Medical Center, in Nara, Japan, between March 2013 and June 2016 were screened for NRIS using our established method. NRIS was defined as severe hypoxemia caused by respiratory inhibition immediately after crying (RIAC) or gastroesophageal reflux (RIGER) or as a respiratory pause during feeding (feeding hypoxemia), accompanied clinically by central cyanosis and a decrease in SpO2 to less than 70%. All infants were monitored using pulse oximetry immediately after birth. Diagnosis of RIAC, feeding hypoxemia, and RIGER are based on observation by both parents and medical staff as well as on on-screen computer analysis using specific software. All infants were examined at a one-month check-up. Parents of the infants who experienced one or more episodes of NRIS accompanied by a decrease in SpO2 to less than 70% for more than approximately 60 s received a questionnaire by mail about their child's development. We conducted a logistic regression analysis with developmental problems as the dependent variable.Results: NRIS was observed in 362 (28.5%) infants; 216 (17.0%) infants showed RIAC, 254 (20.0%) infants showed feeding hypoxemia, and 54 (4.2%) infants showed RIGER. Although all infants were monitored in the maternity ward nursery, 184 (85.2%) infants with RIAC and 111 (43.7%) infants with feeding hypoxemia were overlooked. All infants with NRIS were found to have successfully recovered at one month after birth. Sixty-two cases were examined in the follow-up study by the mailed questionnaire. The median age of the subjects at time of study was 22 months. Fourteen cases (22.6%) exhibited developmental problems including delayed speech development, stereotyped interests and behaviors, sensory disturbance, hyperactivity, delayed motor development, and short stature. Developmental problems tended to relate to shorter gestational age (odds ratio, 0.622; p = .068; 95% CI, 0.373-1.036), smaller birth weight (odds ratio, 0.998; p = .069; 95% CI, 0.997-1.000), and maximum duration of SpO2 to less than 70% by RIAC (odds ratio, 1.009; p = .086; 95% CI, 0.999-1.020). All cases had experienced severe hypoxemia accompanied by a decrease in SpO2 to less than 60%. Seven cases had experienced prolonged hypoxemia accompanied by a decrease in SpO2 to less than 70% for at least 2 min. Among the subjects, 19 infants were examined closely, and their natural course of NRIS was observed in the neonatal intensive care unit. No cases demonstrated abnormal findings with blood examinations, chest-abdominal X-ray, echocardiogram, laryngoendoscopy, hearing loss screening, or mass screening. Only one case had a small intracranial hemorrhage as evidenced in a magnetic resonance imaging of the head.Conclusions: The infants with severe NRIS tended to have developmental problems. Spreading knowledge about NRIS worldwide is thought to be very important. [ABSTRACT FROM AUTHOR]

Background: The role of oxygen therapy in end-of-life care for patients with advanced cancer is incompletely understood. We aimed to evaluate the association between oxygen use and survival in patients with advanced cancer and low oxygen saturation in home care. Methods: We conducted a retrospective cohort study at a primary care practice in suburban Tokyo. Adult patients in home care with advanced cancer demonstrating first low oxygen saturation (less than 90%) detected in home visits were consecutively included in the study. Cox proportional hazards regression was used to investigate the effect of oxygen use on overall survival and survival at home, adjusted for systolic blood pressure, decreased level of consciousness, dyspnea, oral intake, performance status, and cardiopulmonary comorbidity. Results: Of 433 identified patients with advanced cancer, we enrolled 137 patients (oxygen use, n = 35; no oxygen use, n = 102) who developed low oxygen saturation. In multivariable analysis, the adjusted hazard ratio (HR) of oxygen use was 0.68 (95% confidence interval 0.39–1.17) for death and 0.70 (0.38–1.27) for death at home. In patients with dyspnea, the HR was 0.35 (0.13–0.89) for death and 0.33 (0.11–0.96) for death at home; without dyspnea, it was 1.03 (0.49–2.17) for death and 0.84 (0.36–1.96) for death at home. Conclusions: Oxygen use was not significantly associated with survival in patients with advanced cancer and low oxygen saturation, after adjusting for potential confounders. It may not be necessary to use oxygen for prolongation of survival in such patients, particularly in those without dyspnea. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 3-year-old boy with trisomy 13, who was admitted to the hospital because of fever, and hypoxemia, 2-year-old girl with central hypoventilation syndrome, who presented with fever and convulsions due to hyponatremia, and 17-year-old girl admitted to hypoxemia of surgery for congenital heart disease. Topics include the none of these patients came in contact with COVID-19 patients, and the SARS-CoV-2 on rapid antigen test results to be positive for SARS-CoV-2.

Objective: In our previous studies, we documented that threatened premature labor and asymmetrical intrauterine growth restriction were risk factors for respiratory inhibition. The goal of this study was to determine the cause of respiratory inhibition by considering perinatal risk factors.Methods: We examined 1497 infants with a gestational age of 36 weeks or greater. All infants were monitored using pulse oximetry and examined via cranial sonography. Respiratory inhibition was defined as severe hypoxemia caused by respiratory inhibition immediately after crying or gastroesophageal reflux or as a respiratory pause during feeding. We examined the relationships between respiratory inhibition and perinatal factors and speculated on the cause of respiratory inhibition.Results: The median gestational age, birth weight, Apgar score at 1 min, and Apgar score at 5 min of the subjects were 38.9 weeks, 2930 g, 8.0 points, and 9.0 points, respectively. Respiratory inhibition was observed in 422 infants. Lateral ventricle enlargement and increased echogenicity in the ganglionic eminence were observed in 417 and 516 infants, respectively. Respiratory inhibition was significantly correlated with shorter gestational periods, twin pregnancies, lateral ventricle enlargement, and increased echogenicity in the ganglionic eminence.Conclusions: We speculate that umbilical cord compression is a major cause of respiratory inhibition. [ABSTRACT FROM AUTHOR]

Objective: To analyze data from a registry of Japanese neonates with hypoxic respiratory failure associated with pulmonary hypertension (PH) to compare the effectiveness of inhaled nitric oxide (iNO) in neonates born <34 weeks vs. ≥34 weeks gestational age (GA). Materials and methods: iNO was administered according to approved Japanese product labeling. Study data were collected before iNO administration and at predefined intervals until discontinuation. Results: A total of 1,114 neonates were included (n=431, <34 weeks GA; n=675, ≥34 weeks GA; n=8, missing age data). Mean decrease from baseline oxygenation index (OI) was similar in both age groups. OI reduction was more pronounced in the <34 weeks subgroups with baseline OI ≥25. Survival rates were similar in the <34 weeks GA and ≥34 weeks GA groups stratified by baseline OI (OI<15, 89% vs. 93%; 15≤OI<25, 85% vs. 91%; 25≤OI≤40, 73% vs. 79%; OI>40, 64% vs. 66%). Conclusion: iNO improved oxygenation in preterm neonates as effectively as in late preterm and term neonates, without negative impact on survival. If clinically significant PH is present, as measured by pulse oximetry or echocardiography, a therapeutic trial of iNO might be indicated for preterm neonates. [ABSTRACT FROM AUTHOR]

We investigated the effects of resistance exercise under hypoxia on postexercise hemodynamics in eight healthy young males. The subjects belonged to a track & field club (sprinters, hurdlers, and long jumpers) and engage in regular physical training (1-2 h per day, 3-5 days per week). Each participant performed eight sets of bilateral leg squats with a one-minute interval under normoxia (room air) and hypoxia (13 % FiO2). During a 60-minute recovery, we set normoxic condition either after normoxic or hypoxic exercise. These two experimental protocols (normoxia and hypoxia) were performed in a random order with a one-week washout period. The leg squat exercise consists of 50 % 1-RM (14 repetitions) × 5 sets and 50% 1-RM (repetitions max; 7 repetitions) × 3 sets. The resting period between each set was 1 min, and a total of 91 repetitions were performed. Blood pressure, heart rate (HR), and several biomarkers were measured pre- and postexercise. The mean arterial pressure (MAP) significantly decreased after exercise compared to the pre-exercise values under both conditions (P < 0.05). The MAP at 20 and 30 min of recovery in hypoxia was significantly lower than in normoxia (P < 0.05, respectively). The antidiuretic hormone significantly increased after 60 min of recovery in both conditions; moreover, the values in hypoxia were significantly higher than those in normoxia (P < 0.05). The delta changes in MAP from baseline (pre-exercise) were significantly related to changes in HR from baseline in normoxia (r = 0.560, P < 0.001) but not in hypoxia. These results suggest that the hypoxic condition elicits greater hypotension after resistance exercise in comparison to normoxia. Moreover, the underlying mechanisms for the attenuation of hypotension after resistance exercise may differ between normoxia and hypoxia. [ABSTRACT FROM AUTHOR]

Hypoxia is associated with mass mortality in estuaries, but a direct causal relationship has not been proven to date. This study aimed to demonstrate this relationship and to evaluate how the duration of hypoxia affects the survival of ark shells ( Anadara kagoshimensis ) using mathematical modeling. The dissolved oxygen concentration was monitored at two stations in the innermost area of Ariake Bay, Japan, to calculate the duration of hypoxia. This was then included in a mathematical model to simulate the population density with sequential computation. The population density decreased with prolonged hypoxia, reaching a value close to the observed population density, indicating that hypoxia is the main cause of mass mortality in ark shells. Furthermore, the ark shell population disappeared in 8 days with constant hypoxia but persisted when hypoxia was alternated with normoxia every 6 h. Therefore, mass mortality is caused by the duration rather than the frequency of hypoxia. [ABSTRACT FROM AUTHOR]

A 48-year-old man developed general fatigue, dyspnea, and fever at an altitude of 1562 m from the morning of the first day of a 3-day hike. Despite pharyngeal discomfort and mild general fatigue, he felt that the symptoms were not sufficient to abandon his plan. He usually required 1.5 hours to reach Tokusawa (6.4 km from the starting point at an altitude of 1500 m), but this time he required 2.5 hours and slept briefly upon arrival at Tokusawa due to extreme fatigue and respiratory discomfort. His symptoms became aggravated, so he presented at a mountain clinic with oxygen saturation at 80% and body temperature of 37.6ºC. He was diagnosed with hypoxemia due to pneumonia and/or other disease(s) and was evacuated to a hospital where a chest computed tomography scan revealed ground glass opacity and infiltrative shadows. He was treated for pneumonia, but another doctor discovered during follow-up that the patient had sprayed 300 mL of a waterproofing aerosol on mountain equipment in a nonventilated, enclosed area of his home on the night before starting out on the hike. Therefore, waterproofing spray was considered to have caused pulmonary damage. Self-reporting or appropriate questionnaires are the only means of identifying this type of injury. The differential diagnosis of pulmonary problems in an outdoor setting should include toxic aerosol exposure from waterproofing spray. [ABSTRACT FROM AUTHOR]

The present study was designed to determine the effect of 5 consecutive days of repeated sprint training under hypoxia on anaerobic performance and energy substances. Nineteen male sprinters performed repeated sprints for 5 consecutive days under a hypoxic (HYPO; fraction of inspired oxygen [FiO2], 14.5 %) or normoxic (NOR; FiO2, 20.9 %) condition. Before and after the training period, 10-s maximal sprint, repeated sprint ability (5 x 6-s sprints), 30-s maximal sprint, and maximal oxygen uptake (VO2max) tests were conducted. Muscle glycogen and PCr contents were evaluated using carbon magnetic resonance spectroscopy (13C-MRS) and phosphorus magnetic resonance spectroscopy (31P-MRS), respectively. The HYPO group showed significant increases in power output during the 10-s maximal sprint (P = 0.004) and repeated sprint test (P = 0.004), whereas the NOR group showed no significant change after the training period. Muscle glycogen and PCr contents increased significantly in both groups (P < 0.05, respectively). However, relative increases were not significantly different between groups. These findings indicated that 5 consecutive days of repeated sprint training under hypoxic conditions increased maximal power output in competitive sprinters. Furthermore, short-term sprint training significantly augmented muscle glycogen and PCr contents with little added benefit from training in hypoxia. [ABSTRACT FROM AUTHOR]

Background: Sleep disordered breathing (SDB) is associated with decreased psychomotor vigilance (hereafter "vigilance") in clinical settings, but this association has yet to be confirmed in the general population. The aim of this study is to determine the associations between SDB and vigilance in a large sample of community-based participants.Methods: The study sample consisted of 1508 community-dwelling Japanese persons (age: 30-79 years, women: 62.7%, mean body mass index [BMI]: 23.1 kg/m2). Vigilance was measured by the psychomotor vigilance task (PVT), and SDB was measured by overnight pulse oximetry. We investigated odds ratios for "high mean reaction time (RT)" and "high number of lapses," which we defined as the 75th percentile of each value, across categories of oximetry values (three percent oxygen desaturation index [ODI], 4% ODI, average oxygen saturation, minimum oxygen saturation).Results: Multivariable-adjusted odds ratios of high mean RT and high number of lapses in severe SDB (3% ODI ≥ 30.0 events/h) were 3.0 (95% confidence interval: 1.0-8.9; P for trend = 0.03) and 3.3 (95% confidence interval: 1.2-9.2, P for trend = 0.03), respectively, compared to participants without SDB. Similar associations were observed between PVT metrics and four percent ODI. No significant associations between average oxygen saturation and PVT metrics were observed. Minimum oxygen saturation was significantly associated with the trend of high number of lapses (P for trend = 0.007), but not with high mean RT.Conclusions: The present study provides evidence that the intermittent hypoxia in SDB is significantly associated with the deterioration of PVT outcome metrics. [ABSTRACT FROM AUTHOR]

Aim We conducted a retrospective analysis of summary medical reports of children diagnosed with cerebral palsy (CP) to identify clinical features of antenatal onset of CP secondary to transient ischemia in utero. Methods The 658 brief summary reports available in the Japan Obstetric Compensation System for Cerebral Palsy were screened, and we identified cases of singleton pregnancy, delivered at gestational age ≥ 33 weeks and those with cord blood gas pH ≥ 7.20. Of the 137 cases identified, 84 were excluded for the following reasons: no evidence of ischemic brain lesion, clear post-natal causative factor of CP, presence of a congenital condition, and sentinel hypoxic event, such as uterine rupture. The demographic profiles of the 53 cases included in our analysis were compared to identify those with and without an abnormal variability in fetal heart rate. Results Between-group comparison identified an association between abnormal heart rate variability and a lower Apgar score at 1 min (2 vs 6; P < 0.001) and 5 min (5.5 vs 8; P = 0.002), and more frequent episodes of fetal movement loss (41% vs 10%; P = 0.027). An hypoxic event ≤ 1 week before delivery was more likely to be associated with abnormal heart rate variability (89%) and low Apgar score (82%), while events at > 1 week were associated with development of polyhydramnios (44%). Conclusion In utero transient ischemic events can contribute to term or near-term CP. Careful follow-up is recommended for fetuses with a history of fetal movement loss, abnormal variability in heart rate, and polyhydramnios of unknown causes. [ABSTRACT FROM AUTHOR]

Aims Exposure to high altitudes especially with rapid ascent may induce hypoxic pulmonary vasoconstriction ( HPV) and pulmonary hypertension ( PH) possibly leading to life-threatening high-altitude pulmonary edema ( HAPE). The aim of the study was to evaluate the incidence of PH on a 1-day rapid ascent up Mount Fuji (3775 m) in recreational climbers and also to determine the effectiveness of sildenafil for this rapid ascent-induced PH as measured by echocardiography. Methods and results Twenty-five subjects who climbed Mount Fuji showed significantly increased pulmonary artery systolic pressure ( PASP) from 22.3 ± 5.3 mmHg at sea level to 29.4 ± 8.7 mmHg at 3775 m. Five subjects showed PASP >35 mmHg (35.6-46.2 mmHg, average 42.0 ± 3.9 mmHg) and took oral sildenafil 50 mg after which PASP decreased significantly to 24.5 ± 4.6 mmHg (18.7-31.0 mmHg) after 30 minutes. Conclusions One-day rapid ascent of Mount Fuji may induce mild-to-moderate PH and intervention with sildenafil can reduce this PH, suggesting that the therapeutic use of sildenafil would be more reasonable for the relatively infrequent occurrence of altitude-induced PH than its prophylactic use. [ABSTRACT FROM AUTHOR]

Hypobaric hypoxic brain injury results in elevated peripheral S100B levels which may relate to blood-brain barrier (BBB) dysfunction. A period of acclimatisation or dexamethasone prevents altitude-related illnesses and this may involve attenuation of BBB compromise. We hypothesised that both treatments would diminish the S100B response (a measure of BBB dysfunction) on re-ascent to the hypobaric hypoxia of high altitude, in comparison to an identical ascent completed 48 h earlier by the same group. Twelve healthy volunteers, six of which were prescribed dexamethasone, ascended Mt Fuji (summit 3700 m) and serial plasma S100B levels measured. The S100B values reduced from a baseline 0.183 µg/l (95 % CI 0.083-0.283) to 0.145 µg/l (95 % CI 0.088-0.202) at high altitude for the dexamethasone group (n = 6) and from 0.147 µg/l (95 % CI 0.022-0.272) to 0.133 µg/l (95 % CI 0.085-0.182) for the non-treated group (n = 6) [not statistically significant (p = 0.43 and p = 0.82) for the treated and non-treated groups respectively]. [These results contrasted with the statistically significant increase during the first ascent, S100B increasing from 0.108 µg/l (95 % CI 0.092-0.125) to 0.216 µg/l (95 % CI 0.165-0.267) at high altitude]. In conclusion, an increase in plasma S100B was not observed in the second ascent and this may relate to the effect of acclimatisation (or hypoxic pre-conditioning) on the BBB. An exercise stimulated elevation of plasma S100B levels was also not observed during the second ascent. The small sample size and wide confidence intervals, however, precludes any statistically significant conclusions and a larger study would be required to confirm these findings. [ABSTRACT FROM AUTHOR]

To clarify effects of hypoxia on feeding and somatic condition of blackfin flounder Glyptocephalus stelleri, we studied the temporal relationship between hypoxia and feeding intensity as well as the condition of this species in May and August 2006-2012. Hypoxia occurred near the seafloor in August between 2010 and 2012 but not in May. Population densities of gammarid amphipods Ampelisca brevicornis and Melita sp., the main prey items of blackfin flounder, were consistently low; however, the somatic condition and feeding intensity of blackfin flounder increased during hypoxia. Such an increase was not detected in May 2012 under non-hypoxic conditions. These facts imply that the hypoxia increased prey availability for blackfin flounder through the increased exposure of the gammarids over the sea floor, and, thus, resulted in improved body condition in August 2011 and 2012. Hypoxia positively would influence the somatic condition and feeding intensity of blackfin flounder in Funka Bay in August 2011 and 2012; however, the somatic condition during this period did not reach the levels recorded in 1983, suggesting that habitat quality for blackfin flounder in Funka Bay in 2011 and 2012 was worse than that in 1983. [ABSTRACT FROM AUTHOR]

Aim The aim of this study was to determine perinatal factors associated with cerebral palsy ( CP) in infants treated with brain hypothermia ( BHT). Material and Methods We carried out a retrospective review of 23 infants with hypoxic ischemic encephalopathy in whom BHT was applied within 6 h after birth. Outcome regarding the presence or absence of CP was assessed at the age of 18 months. Oxygen extraction fraction ( OEF) was measured before, during and after BHT at the jugular sinus. Results Three infants died and 12 developed CP (poor outcome group). The remaining eight infants did not have CP at 18 months old (favorable outcome group). There were no differences in gestational age, birthweight, pH, base deficit, or lactate level between infants with favorable and poor outcomes. Infants with flat trace on electroencephalography on admission were less likely to have favorable outcome (0.0% [0/8] vs 53% [8/15], respectively, P = 0.02), while those with Apgar score at 10 min ≥5 (57% [8/14] vs 0.0% [0/9], P = 0.007) or ≥6 (70% [7/10] vs 7.7% [1/13], P = 0.002), OEF ≥ 13.3% during BHT (64% [7/11] vs 8.3% [1/12], P = 0.009), and OEF ≥ 18.5% after BHT (73% [8/11] vs 0.0% [0/12], P = 0.002) were more likely to have favorable outcome compared with those with counterpart characteristics. Conclusion Infants with an Apgar score at 10 min ≥5, activity on electroencephalography on admission, and higher OEF during and after BHT were likely to have a favorable outcome. [ABSTRACT FROM AUTHOR]

Yaks have adapted to high altitude and they do not develop hypoxic pulmonary hypertension. Although we previously identified the important role of augmented nitric oxide synthase activity in the yak pulmonary circulatory system, evidence of the direct involvement of Rho-kinase as a basal vascular tone regulator is lacking. Four domesticated male pure-bred yaks and four bulls that were born and raised at an altitude of 3000 m in the Tien-Shan mountains were studied at an altitude of 3,100 m. Mean pulmonary artery pressure (mPAP) was measured before and after fasudil (60 mg in 20 mL of saline) was intravenously administered using a Swan-Ganz catheter at a rate of 3.3 mL/min for 30 min. Fasudil decreased mPAP in bulls from 67.8±14.9 to 32.3±5.3 mmHg (P<0.05) after 15 min and the level was maintained for 30 min, but it merely blunted mPAP in yaks from 28.2±4.5 to 25.1±11.1 and 23.2±2.7 mmHg after 5 and 30 min, respectively. These findings comprise the first evidence of a modest role of Rho-kinase in the maintenance of pulmonary artery pressure in the yak. [ABSTRACT FROM AUTHOR]

Abstract: Background: There are few articles on mortality and morbidity of adult patients with Eisenmenger's syndrome (ES) in the current era when disease targeting therapy (DTT) has been available. Methods and results: 198 patients (a median age 35years, 64% female) with ES who visited the 16 participating institutes in Japan and Korea from 1998 to 2009 were enrolled. Clinical data during adulthood were collected from each institutional chart and analyzed centrally. During a median follow-up of 8years, 30 patients died including 14 sudden deaths. 89 patients took oral medication of DTT and clinical improvement was observed in 54 of them. However, survival rate in patients taking DTT was not different from those without (87% vs 84%, p=0.55). When the clinical data in between first and last clinic visits were compared in 85 patients, the patients with NYHA ≧ III increased from 24% to 48% (p<0.001), SpO2 decreased from 89% to 85% (p=0.008) and hematocrit increased from 51.4% to 52.9% (p=0.04). Non-survivors had poorer NYHA function class, lower body weight (BW), lower body mass index (BMI), and higher serum level of Cr at the first visits than survivors. Conclusions: Long term survival and clinical status of adult patients with ES remains unsatisfactory even in the current era of DTT. Poor NYHA functional class, low BW, low BMI and high serum level of Cr were related to mortality. DTT therapy improved clinical status in many patients with Eisenmenger's syndrome, but no significant impact on survival could be shown. [Copyright &y& Elsevier]

Monitoring sediment microbial community metabolism and structure is instrumental to understanding biogeochemical processes in and ecological impacts on bottom environments. The aim of this study was to determine potential community respiration and to reveal community dynamics of the microorganisms in the dead zone sediments of Omura Bay, Japan. The bay is highly enclosed and develops severe hypoxia in the central regions every summer. We collected sediment core samples from the center of the bay during hypoxia, estimated sediment oxygen consumption by using an adapted in vivo electron transport system activity (in vivo ETSA) assay, enumerated abundance of bacteria, and analyzed bacterial community structure by automated ribosomal intergenic spacer analysis. Higher ETSA and bacterial diversity were found in upper sediments (within 3 cm depth) from the center than the fringe of the bay. Sediment bacterial community structure of the bay center was distinct from that of the fringe. From these results, upper sediment in the dead zone of Omura Bay was characterized by (1) greater community respiration and (2) greater diversity of bacterial components compared with the non-hypoxic sediment of the bay fringe. These characteristics have important implications for understanding the interaction between microbial communities and the development of hypoxia in Omura Bay. [ABSTRACT FROM AUTHOR]

Abstract: In order to infer the late Late Permian to early Early Triassic environmental changes in a pelagic realm of the Panthalassic Ocean, the stratigraphic variations of TOC (wt.%) and δ13Corg (‰) of the PTB siliceous rock section (~3.5m in thickness) were examined. The study section crops out in the Mino terrane, central Japan, and consists of the upper Upper Permian chert (Changhsingian) and lower Lower Triassic (Induan) black claystone intermittently with thin chert beds. The succession is reconstructed as sediments on the lower slope of a mid-Panthalassic seamount. The major extinction event of Permian radiolarians (MEE) occurs at the top of the Changhsingian chert. Our analysis shows that the TOC content is markedly higher in the Induan black claystone than the Changhsingian chert. TOC values rapidly increase across the PTB. The onset of the increase in TOC values corresponds to MEE. The rapid and profound increase in TOC values implies the sudden onset of oceanic anoxia as well as the rapid increase in primary production at the PTB. δ13Corg values are generally higher in the Changhsingian chert than the Induan claystone and chert. The stepwise drop of δ13Corg values characterizes their excursion of the study section. The largest-scale drop occurs prior to MEE. The minimum δ13Corg value is recorded at the base of the Induan claystone. The flux of δ13C-depleted gasses related to the Siberian Traps could have significantly contributed to the marked drop of δ13Corg values. Due to the weakened ocean circulation under the predominant condition of global warming, oceanic anoxia suddenly took place at the end of the Permian. The anoxic condition in the surface layer was the most likely kill-mechanism for Permian radiolarians. The anoxic condition persisted into the Induan, but was intermittently weakened. The episodic relaxation of the anoxic condition in the Induan resulted in intermittent and transient blooming of radiolarians and deposition of radiolarian chert with lowered TOC values. These biotic and depositional records of the study section imply the mid-Panthalassic Ocean was under the more hospitable conditions favored by the earlier recovery of radiolarians, relative to the Tethys Ocean and Pangean marginal seas. [Copyright &y& Elsevier]

Abstract: This paper proposes a method of evaluating the occurrence of hypoxia or anoxia in bottom water of Tokyo Bay, which is typical of enclosed bays in Japan. In Tokyo Bay, the exchange of seawater with the ocean has previously been found to be dominantly controlled by estuarine circulation. Thus, one would expect the concentrations of dissolved oxygen (DO) in the bay head to be influenced mainly by estuarine circulation, which changes according to wind strength and river discharges. We investigated the effects of wind and river discharge on DO concentration around the bay head using a three-dimensional ecological model. To evaluate the occurrence of hypoxic or anoxic water, we developed a conceptual DO model, which was verified through the good agreement with the results from a three-dimensional ecological model. We conclude that the conceptual DO model has good potential for evaluating the factors leading to hypoxic or anoxic water around the bay head. Modeling suggested that, on average, wind effects were the dominant factor in the variation of bottom DO concentrations. However, we found that the contribution of extreme events, such as floods and strong winds exceeding 10 m s−1, was 50% or more. This suggests that extreme events play an important role in controlling the variation in DO concentration at the bottom of Tokyo Bay. [Copyright &y& Elsevier]

Background: The aim of this study was to clarify the timing of injuries in utero that cause respiratory inhibition after crying (RIAC). We evaluated infants with cranial ultrasound abnormalities diagnosed during hospitalization. Methods: We retrospectively examined the medical records of preterm infants who were treated in the neonatal intensive care unit at Nara Prefectural Hospital in Nara, Japan from January 2006 through December 2010. Inclusion criterion was gestational age less than 34 weeks. We evaluated the perinatal factors and cranial ultrasound abnormalities associated with RIAC, feeding hypoxemia, and prolonged apnea. We also evaluated the timing of appearance of cranial ultrasound abnormalities. Results: A total of 125 infants were examined. Mean gestational age was 30.6 ± 2.4 weeks and mean birthweight was 1465 ± 454 g. The numbers of infants who showed RIAC, feeding hypoxemia, and prolonged apnea were 44, 48, and 63, respectively. Among 91 infants who showed cranial ultrasound abnormalities, 67 had increased echogenicity in the ganglionic eminence (GE). There was a significant correlation between increased echogenicity and RIAC ( P < 0.001). Of the infants who showed increased echogenicity in the GE, 19 had this finding during the course of hospitalization. In these 19 infants, however, gestational age of those with RIAC was less than 31 weeks. Conclusion: We speculate that the timing of intrauterine injury resulting in RIAC in infants is less than 31 gestational weeks. [ABSTRACT FROM AUTHOR]

The article reports on research which was conducted to investigate the effects low-intensity resistance exercise under acute systemic hypoxia had on hormonal responses in athletes. Researchers evaluated eight male subjects. They found that low-intensity resistance exercise in the hypoxic condition caused greater metabolic and hormonal responses than that in the normoxic condition and that coaches should consider this type of exercise for athletes who need to maintain muscle mass and strength.

To clarify the mechanism of hypoxia in the western interior parts of the Ariake Sea (WIAS), field observation data collected in the period of 1972-2004 were analyzed using a two-layer box model. Monthly averages of advection velocity, vertical diffusion coefficient ( K), and biochemical oxygen consumption rate ( R) in WIAS were evaluated quantitatively during the above period. The estimated advection velocity comparatively corresponded to the observed residual flow pattern of bay head in summer and winter. The estimated K was relatively high (0.6-5.3 cm s) from September to March but lower (0.2-0.4 cm s) from April to August. The estimated R ranged from 0.30 to 0.46 mg L day during May to August. In summer, the temporal variation of dissolved oxygen (DO) concentration in the lower layer was controlled largely by K and R. Monthly variations of K, R, and degree of density stratification ( P) in the 1970s, the 1980s, and the 1990s-early 2000s were analyzed. P, K, and R were not significantly different among the calculated periods ( p = 0.93, 0.23, and 0.49). However, the variations of R in summer between the 1970s and the other calculated periods changed. DO consumption period was longer in the 1980s and the 1990s-early 2000s than in the 1970s. R in the 1980s was highest among the calculated periods. The increase in R in the 1980s was caused by the increase in organic matter load originating from red tide phytoplankton due to a decrease in the suspension feeders. [ABSTRACT FROM AUTHOR]

Abstract: Terrigenous loading into enclosed water bodies has been blamed for eutrophic conditions marked by massive algal growth and subsequent hypoxia due to decomposition of dead algal cells. This study aims to describe the eutrophication and hypoxia processes in a semi-enclosed water body lying near a big metropolis. Phosphorus mass balance in a small inlet, Ohko Inlet, located at the head of Hiroshima Bay, Japan, was quantified using a numerical model. Dissolved inorganic phosphorous inflow from Kaita Bay next to the inlet was five times higher than that from terrigenous load, which may cause an enhancement of primary production. Therefore, it was concluded that not only the reduction of material load from the land and the suppression of benthic flux are needed, but also reducing the inflow of high phosphorus and oxygen depleted water from Kaita Bay will form a collective alternative measure to remediate the environmental condition of the inlet. [Copyright &y& Elsevier]

The article discusses a study by Akihiko Hiyama and colleagues which examined whether hypoxia regulates Notch signaling or not, and the role of Notch in intervertebral disc cell proliferation, to understand its implications for degenerative disc disease. It is inferred that Notch signaling plays a vital role, thereby offering a therapeutic target for the restoration of cell numbers during degenerative disc disease.

In order to establish an effective screening method for respiratory inhibition after crying (RIAC), we prospectively studied the correlations between infant RIAC and perinatal factors. We monitored infants ( n = 141) born from May through July 2009 with polygraphy and evaluated the presence of RIAC and respiratory pause that occurred when feeding was initiated immediately after crying with a decrease in oxygen saturation (SpO) to <60%. The infants were screened for increased echogenicity, a cyst in the ganglionic eminence (GE), or a subependymal cyst by cranial ultrasound. Furthermore, we evaluated the correlations between RIAC and perinatal factors. Eleven infants displayed RIAC and 31 experienced respiratory pause during feeding with a decrease in SpO to <60%. There were no significant correlations between RIAC and perinatal factors. Forty infants had ultrasound abnormalities (increased echogenicity in the GE, 26; cyst in the GE, nine; and subependymal cyst, seven). Sensitivity, specificity, and efficiency of abnormal cranial ultrasound findings for RIAC were 1.00, 0.777, and 0.794, respectively. The odds ratio, sensitivity, specificity, and efficiency of the combination of abnormal cranial ultrasound findings and respiratory pause during feeding with a decrease in SpO to <60% and RIAC were 35.9 ( P < 0.001), 0.727, 0.931, and 0.915, respectively. The combination of abnormal cranial ultrasound findings and respiratory pause during feeding with a decrease in SpO appears to be an effective method of screening for RIAC. [ABSTRACT FROM AUTHOR]

To clarify the effects of altitude acclimatization on postural instability at altitudes, six female climbers stood with their eyes open or closed on a force-measuring platform under normoxia (NC) and hypobaric hypoxia, equivalent to a 5,000 m altitude (HC), before and after an expedition to Mt. Cho-Oyu (8,201 m). The expedition extended over 84 days. We recorded sways in the center of foot pressure, electromyograms (EMGs) of lower-leg muscles, blood components and arterial oxygen saturation (SpO(2)). Before the expedition, the maximum amplitude of sway with the eyes open and integrated EMG from the medial gastrocnemius increased for HC. After the expedition, red blood cell (from 423.4 ± 15.4 to 498.0 ± 24.5 × 10(4) μl(-1)), hemoglobin content (from 12.6 ± 0.32 to 14.5 ± 1.00 g/dl) and 2,3-diphosphoglycerate (from 1.93 ± 0.21 to 2.24 ± 0.34 μmol/ml) increased. The SpO(2) under HC increased from 69.2 ± 9.6 to 77.2 ± 10.0%. The maximum amplitude of sway with the eyes open decreased for HC. No difference in the sway path length and integrated EMGs was observed between NC and HC. These results suggest that acclimatization can improve the impaired postural stability on initial arrival at altitudes. However, it is still unclear how long acclimatization period is needed. Further studies are needed to reveal this point. [ABSTRACT FROM AUTHOR]

Important crustacean fisheries occur in semi-enclosed seas. These fisheries can be strongly affected by intense exploitation and episodic anthropogenic and climatic events, but the effects of such events remain largely uninvestigated. To assess the influence of such factors, we examined dredge catch data on the gazami crab Portunus trituberculatus in Osaka Bay, Japan from 1984 to 2008 and investigated various associated environmental factors. There were five peak monthly catches during the study period, which typically occurred in August or November. Relative abundance (measured as catch per unit effort) in August was positively associated with previous recruitments to the fishery, typhoon frequency, and dissolved oxygen saturation during the juvenile period. In comparison, relative abundance in November was strongly correlated with the number of typhoons and was also positively associated with dissolved oxygen levels in the bottom water. The results of our multi-decadal study suggest that hypoxia is a principal agent of mortality for juvenile crabs and that normoxia in the nursery habitats is a necessary condition for the successful recruitment of individuals into the adult population. The positive influence of typhoons on recruitment is probably due increased mixing in stratified coastal waters, which disrupts the persistent hypoxia in bottom waters, but other unknown processes may also contribute to favorable recruitments. [ABSTRACT FROM AUTHOR]

Application of a mechanical circulator was considered to reduce hypoxia and anoxia in an estuarine trench by numerical examination in terms of the required flow rate and direction along with the physical mechanism of its effectiveness. We then developed a prototype of the circulator, generating downward flow by an impeller attached to the main body of the circulator floating on the surface, in which the surface water is being transported to the bottom through a flexible draft tube connected to the floating body. The effectiveness of the proposed mechanical circulator was verified by performing field tests in a dredged trench in Tokyo Port of Tokyo Bay, while monitoring current and water and sediment quality. The field test results showed that the mechanical circulator achieved the desired effects, including reduction in hypoxia and improvement of water and sediment quality in the trench. We also applied a primitive equation model and found that the model can successfully reproduce the field test results. The present study shows the availability of a mechanical circulator and an effective application methodology in the field. [ABSTRACT FROM AUTHOR]

Aim: The number of alpine accidents has been increasing among trekkers in Japan. Some of the alpine accidents have been related to acute mountain sickness (AMS). At present, the mechanism of AMS is poorly clarified, however, it is well known that hypoxia at high altitudes plays an important role. A good relation exists between proteinuria, altitude and hypoxia. However, no reports are available concerned with the risk factors of proteinuria for trekkers at high altitudes. Methods: The authors evaluated 41 trekkers and 13 highlanders (cabin employees) through physical examinations and interviews held in a mountain cabin (2300 m above sea level) located in a mountain (2926 m above sea level) in the Japanese Alps. First, urine samples were collected and urinalysis was performed. Second, non-invasive blood pressure, heart rate, and arterial oxygen saturation (SpO2) were measured using a portable life monitor. Results: Proteinuria was present in 20 (49%) participants. Past history of hyperlipidaemia, amount of sleep, and smoking history are independently associated with proteinuria. Among the physiological examinations conducted at the cabin, only systolic blood pressure demonstrated strong association with proteinuria. Receiver operating characteristic curve analysis using a score combining past history of hyperlipidaemia, amount of sleep and smoking history revealed that the diagnostic accuracy of proteinuria at the cut-off score of 2 was 80%. Conclusions: This study indicated that these three variables were significantly and independently correlated with proteinuria: hyperlipidaemia, amount of sleep (night before) and smoking history. Improvement of these three variables might decrease the risk of alpine accidents including AMS. [ABSTRACT FROM AUTHOR]

Effects of hypoxia on the principal prey and growth of flathead flounder Hippoglossoides dubius were studied in Funka Bay. Of the three dominant year-classes that occurred in recent years, the 1995 year-class was small in total length at age ≥ 3 and low in condition factor at age ≥ 2. Ophiuroids (almost Ophiura sarsi), which were the dominant prey in the 1980s, were of little importance and instead, crustaceans such as mysids, natant decapods and pelagic amphipods, bivalves and fish were important prey items for H. dubius in 2000–2001. In addition, the feeding intensity of H. dubius in 2000–2001 was lower than that in the 1980s. These facts are closely related to a reduction of prey abundance, particularly ophiuroids. It seems that the hypoxia that occurred in the central part of the bay during the summer and autumn of 1995–1997 caused the poor food supply and low growth rate at ages 2–4 of the 1995 year-class. [ABSTRACT FROM AUTHOR]

Objective: To clarify the clinical features and pathogenesis of intussusception in neonates. Methods: Fourteen neonates were diagnosed with intussusception between June 1974 and January 2001. Patients were divided into two groups according to whether or not signs were present on the first day of life. The clinical features were interrelated with the pathological findings. Results: All six patients in the group whose signs were present on the first day of life also had intestinal atresia or malrotation. Among patients whose signs began less than 24 h after birth, five of eight patients suffered hypoxia. Moreover, it was very difficult to establish the diagnosis of intussusception, particularly in the group of late-onset type intussusception. Conclusions: Hypoxic events may play a crucial aetiologic role in the pathogenesis of late-onset neonatal intussusception. [ABSTRACT FROM AUTHOR]

Low oxygen concentration or hypoxia plays a crucial role in the diagnosis and treatment of tumours and cancer. Although there are some existing techniques, such as proton magnetic resonance imaging (MRI), for the detection of molecular oxygen in tissues, new non-invasive techniques for directly measuring the extent and spatial distribution of hypoxia in cancerous or tumorous tissues are still needed. In this study, we propose a new non-invasive method using muons that are available in accelerator facilities, such as the Japan Proton Accelerator Research Complex in Japan and the Rutherford Appleton Laboratory in the UK. Unlike existing MRI methods, the proposed muon-based method can be applied without any external magnetic field. With the help of muonium response in solutions, we measured oxygen concentration in the aqueous solutions of various biological materials, such as haemoglobin, albumin, serum, and tris-buffered saline, under controlled molecular oxygen concentrations. The observed relaxation rate pattern of muonium through a fixed oxygen concentration sample and that with a sample concentration of less than 1% oxygen shows that this method may be applicable in detecting molecular oxygen levels in various tissues of the human body. Based on our experimental results, we have estimated the expected muonium spectra in normal physiological concentrations of haemoglobin in blood. Further systematic studies on other biological solutions are required before a potential clinical application of the method is devised. [ABSTRACT FROM AUTHOR]

The Early Triassic experienced one of the most extensive episodes of oceanic oxygen depletion in the Phanerozoic, which was considered to be reflected in the deposition of black organic-rich claystone and general absence of radiolarian chert in pelagic deep-water areas of Panthalassa. However, while studies of peri-continental sections demonstrate that oceanic anoxia repeatedly occurred throughout the Early Triassic, black claystone deposition was thought to be restricted to earliest Triassic times. In this paper, the lithostratigraphy, conodont biostratigraphy and chemical composition are investigated at two Olenekian–Anisian sections in Japan, deposited in pelagic deep-water areas of Panthalassa. Sedimentation rates and major element compositions support published findings that the absence of chert is a consequence of increased clastic input and not radiolarian extinction due to oceanic anoxia. Biostratigraphic correlation with previously described sections reveals that the deposition of extensive black claystone occurred in the Induan, early Spathian (early late Olenekian) and across the Olenekian–Anisian boundary. The three black claystone lithofacies are associated with sedimentary and geochemical evidence of anoxia in the water column and bottom waters. Organic-rich deposition is generally coeval with episodes of expanded anoxic seafloor as indicated by uranium isotopes, although they are decoupled in Smithian (early Olenekian) times. Black claystone of end-Olenekian to early Anisian age represents the first finding of a laterally extensive deposit associated with oceanic anoxia during this time interval. Results imply that the deposition of black organic-rich claystone in pelagic deep Panthalassa reflects global trends in the spatial extent of bottom water anoxia during the Early Triassic, probably controlled mainly by nutrient input to the oceans. Unlabelled Image • Newly described sections of Lower Triassic pelagic Panthalassic deep-sea claystone. • Upper Olenekian to lower Anisian deep-sea claystone records increased clastic inputs. • Three episodes of organic-rich deposition in the Early Triassic pelagic Panthalassa • The organic-rich deposition mostly coincided with global oceanic anoxia. • First discovery of laterally extensive anoxic deposits of end-Early Triassic age [ABSTRACT FROM AUTHOR]

• The sensitivity to hypoxia differs between life stages of pen shell. • Pen shell adapt hypoxic tolerance as they grow from juvenile to 1-year-old. • 2-year-old pen shells were more susceptible than 1-year-old shells to hypoxia. • The environmental tolerance of bivalves does not depend on body size as they grow. • Reproductive status might be associated with reduced hypoxic tolerance. Pen shell (Atrina cf. japonica) resources have been devastated in Ariake Bay, Japan, and to facilitate the recovery of this species, there is an urgent need to fully understand the factors contributing to its high levels of mortality. Pen shells living in natural waters grow through successive life stages, and environmental factors may affect these bivalves differently at different stages. Accordingly, to elucidate the causes of mortality in natural waters, it is necessary to gain an understanding of the quantitative effects of environmental factors on bivalves at each life stage. In this study, we sought to determine the differential effects of hypoxic conditions on 1-year-old (average shell length: 93.9 mm) and 2-year-old (146.5 mm) pen shells bred under artificial conditions. We exposed shells of each age group to six different dissolved oxygen (DO) concentrations for 96 h and monitored their behavior and survival rate. Based on the survival status, we estimated the lethal DO concentrations that induced 50%, 95%, and 5% mortality (LC 50 , LC 95 , and LC 5 , respectively) at each age. We found that for 1-year-old shells, the LC 50 values at 48, 72, and 96 h were 0.51, 0.74, and 0.84 mg/L, respectively, whereas the corresponding values for 2-year-old shells were 0.74, 1.27, and 1.80 mg/L. Furthermore, we found that for 1- and 2-year-old shells, the estimated ranges from LC 95 to LC 5 at 48, 72, and 96 h were 0.39–0.68, 0.62–0.88, and 0.64–1.12 mg/L, and 0.31–1.75, 0.77–2.09, and 1.29–2.53 mg/L, respectively. Under low DO concentrations (0.47 to 1.93 mg/L and 0.49 to 3.30 mg/L for 1- and 2-year-old shells, respectively), we observed pen shells with more than half of their shell length protruding above the substrate. In addition to age and body size, the 1- and 2-year-old pen shells used in the present study also differed with respect to reproductive status, with 7.6% of 1-year-old and 96.7% of 2-year-old shells considered to be fully ripe. Collectively, our observations indicate that 2-year-old pen shells are less tolerant to hypoxic conditions than are 1-year-old pen shells, and we suspect that the differences in hypoxic tolerance could be attributable to differences in the physiological status of the pen shells during gonadal development. We believe the findings of this study will make an important contribution to enhancing our understanding of the effects of hypoxia on the viability of A. cf. japonica in natural waters. [ABSTRACT FROM AUTHOR]

Purpose: The Japanese Society of Anesthesiologists (JSA) has conducted surveys on life-threatening accidental events during anesthesia and reported results since 1992. This report describes the incidence of these life-threatening accidental events in the survey period between 2012 and 2016., Methods: JSA conducts an annual survey on accidental events. Each participating facility reports life-threatening accidental events that occurred each year. Facilities accredited by the JSA can electronically report events using the JSA Perioperative Information Management System (JSA-PIMS) software program that interfaces with the electronic anesthesia record system., Results: The number of cardiac arrest events per 10,000 anesthesia cases gradually decreased from 2.97 in 2012 to 2.30 in 2016 (odds ratio OR 0.77 95% CI 0.68-0.88). The number of severe hypotension events per 10,000 anesthesia cases gradually decreased from 4.63 in 2012 to 4.24 in 2016 (OR 0.92, 95% CI 0.83-1.01). The number of severe hypoxia events per 10,000 anesthesia cases gradually decreased from 2.01 in 2012 to 1.59 in 2016 (OR 0.79, 95% CI 0.68-0.92). The number of life-threatening arrhythmia events per 10,000 anesthesia cases was 1.14 in 2012. Thereafter, it tended to decrease slightly to 0.88 in 2016 (OR 0.77, 95% CI 0.63-0.95)., Conclusion: The incidence of cardiac arrest during this period was 2.63/10,000, which was lower the incidence reported in other countries. While no change was observed in the incidence of severe hypotension over the survey period, the incidence of severe hypoxia and life-threatening arrhythmia decreased by 20-25% during those 5 years.

The article presents a case study of a 20-month-old girl who was admitted to the hospital with compensated shock and hypoxia along with dyspnea and deteriorated respiration. It talks about the girl being diagnosed with non-typeable Haemophilus influenzae pericarditis which was detected through chest radiography.