Continuous monitoring using thermography can capture the heat oscillations maintaining body temperature in neonates.

The body temperature of infants at equilibrium with their surroundings is balanced between heat production from metabolism and the transfer of heat to the environment. Total heat production is related to body size, which is closely related to metabolic rate and oxygen consumption. Body temperature control is a crucial aspect of neonatal medicine but we have often struggled with temperature measures. Contactless infrared thermography (IRT) is useful for vulnerable neonates and may be able to assess their spontaneous thermal metabolism. The present study focused on heat oscillations and their cause. IRT was used to measure the skin temperature every 15 s of neonates in an incubator. We analyzed the thermal data of 27 neonates (32 measurements), calculated the average temperature within specified regions, and extracted two frequency components-Components A and B-using the Savitzky-Golay method. Furthermore, we derived an equation describing the cycle-named cycle T-for maintaining body temperature according to body weight. A positive correlation was observed between cycle T and Component B (median [IQR]: 368 [300-506] s). This study sheds light on the physiological thermoregulatory function of newborns and will lead to improved temperature management methods for newborns, particularly premature, low-birth-weight infants.

Improvement of point of care testing device for accurate whole blood glucose measurement in early neonates.

BACKGROUND: It is important that blood glucose concentrations be accurately and conveniently measured in infants. However, especially in the early neonatal period, point-of-care testing devices used for adults may not accurately measure blood glucose concentrations in neonates. METHODS: In Study 1, the accuracy of neonatal whole-blood glucose measurements was evaluated for the existing glucose analyser Glutest Mint® (hereinafter MINT1; Sanwa Kagaku Kenkyusho, Nagoya, Japan) by comparing the data with reference blood glucose concentrations. In Study 2, we used MINT2, which was modified based on the findings from Study 1, to measure whole-blood glucose concentrations in newborns, and the accuracy of the measurements was compared with that of MINT1. RESULTS: Blood glucose concentrations were measured in 100 infants each in Study 1 and 2. In Study 1, the whole-blood glucose concentrations measured using MINT1 were found to be significantly lower than the reference blood glucose concentrations in early neonates. The results of Study 1 suggested that characteristics of erythrocyte membranes in early neonates affected the measurements. Therefore, we conducted Study 2 using MINT2, which was modified to be less susceptible. MINT2 was found to accurately measure whole-blood glucose concentrations in the early neonatal period. CONCLUSION: The study showed that the point-of-care testing device could be improved to allow for accurate whole-blood glucose measurements in the early neonatal period.

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.

Conflicting findings on the effectiveness of hydrogen therapy for ameliorating vascular leakage in a 5-day post hypoxic-ischemic survival piglet model.

Neonatal hypoxic-ischemic encephalopathy (HIE) is a major cause of morbidity and mortality in newborns in both high- and low-income countries. The important determinants of its pathophysiology are neural cells and vascular components. In neonatal HIE, increased vascular permeability due to damage to the blood-brain barrier is associated with seizures and poor outcomes in both translational and clinical studies. In our previous studies, hydrogen gas (H2) improved the neurological outcome of HIE and ameliorated the cell death. In this study, we used albumin immunohistochemistry to assess if H2 inhalation effectively reduced the cerebral vascular leakage. Of 33 piglets subjected to a hypoxic-ischemic insult, 26 piglets were ultimately analyzed. After the insult, the piglets were grouped into normothermia (NT), H2 ventilation (H2), therapeutic hypothermia (TH), and H2 combined with TH (H2-TH) groups. The ratio of albumin stained to unstained areas was analyzed and found to be lower in the H2 group than in the other groups, although the difference was not statistically significant. In this study, H2 therapy did not significantly improve albumin leakage despite the histological images suggesting signs of improvement. Further investigations are warranted to study the efficacy of H2 gas for vascular leakage in neonatal HIE.

Quantitative effects of bilirubin structural photoisomers on the measurement of direct bilirubin via the vanadate oxidation method.

BACKGROUND: Exposing blood serum samples to ambient white light-emitting diode (WLED) light may accelerate bilirubin photoisomer production. We previously demonstrated the quantitative effect of bilirubin configurational isomers (BCI) on direct bilirubin (DB) value using the vanadate oxidation method. However, the effects of bilirubin structural photoisomers (BSI) remain unclear. METHODS: In Study 1, the relationship between WLED irradiation time and BSI production was examined. Serum samples from five neonates were irradiated with WLED light for 0, 10, 30, 60 and 180 min. Bilirubin isomer concentration and BSI production rates were calculated. In Study 2, we performed quantitative investigation of BSI effect on DB values: Differences in DB, BCI and BSI values before and after irradiation were calculated as ⊿DB, ⊿BCI and ⊿BSI, respectively. Assuming the coefficient of BCI affecting DB values was 'a', relational expression was ⊿DB = a*⊿BSI + 0.19*⊿BCI. Serum samples from 15 neonates were irradiated with green LED light for 10 and 30 s. The respective bilirubin isomer levels were measured, and the coefficient was derived. RESULTS: In Study 1, the median BSI production rate was 0.022 mg/dL per min in specimens with an unconjugated bilirubin concentration of 10.88 mg/dL. In Study 2, assuming that ⊿DB-0.19*⊿BCI was Y and ⊿BSI was X, the relational expression was Y = 0.34X-0.03 (R2 = 0.87; p < .01) and a = 0.34. CONCLUSIONS: Under ambient WLED light, serum sample generated 1.3 mg/dL BSIs in 1 h. Approximately 34% (0.44 mg/dL) of BSI concentrations was measured as DB when using the vanadate oxidation method according to the above equation.

Impact of hydrogen gas inhalation during therapeutic hypothermia on cerebral hemodynamics and oxygenation in the asphyxiated piglet.

We previously reported the neuroprotective potential of combined hydrogen (H2) gas ventilation therapy and therapeutic hypothermia (TH) by assessing the short-term neurological outcomes and histological findings of 5-day neonatal hypoxic-ischemic (HI) encephalopathy piglets. However, the effects of H2 gas on cerebral circulation and oxygen metabolism and on prognosis were unknown. Here, we used near-infrared time-resolved spectroscopy to compare combined H2 gas ventilation and TH with TH alone. Piglets were divided into three groups: HI insult with normothermia (NT, n = 10), HI insult with hypothermia (TH, 33.5 ± 0.5 °C, n = 8), and HI insult with hypothermia plus H2 ventilation (TH + H2, 2.1-2.7%, n = 8). H2 ventilation and TH were administered and the cerebral blood volume (CBV) and cerebral hemoglobin oxygen saturation (ScO2) were recorded for 24 h after the insult. CBV was significantly higher at 24 h after the insult in the TH + H2 group than in the other groups. ScO2 was significantly lower throughout the 24 h after the insult in the TH + H2 group than in the NT group. In conclusion, combined H2 gas ventilation and TH increased CBV and decreased ScO2, which may reflect elevated cerebral blood flow to meet greater oxygen demand for the surviving neurons, compared with TH alone.

Cerebral hemodynamic response during the resuscitation period after hypoxic-ischemic insult predicts brain injury on day 5 after insult in newborn piglets.

Perinatal hypoxic-ischemic brain injury of neonates remains a significant problem worldwide. During the resuscitation period, changes in cerebral hemoglobin oxygen saturation (ScO2) have been identified by near-infrared spectroscopy (NIRS). However, in asphyxiated neonates, the relationship between these changes and brain injury is not known. Three-wavelength near-infrared time-resolved spectroscopy, an advanced technology for NIRS, allows for the estimation of ScO2 and cerebral blood volume (CBV). Here, we studied changes in ScO2 and CBV during the resuscitation period after hypoxic-ischemic insult and the relationship between these changes after insult and histopathological brain injuries on day 5 after insult using an asphyxiated piglet model. Of 36 newborn piglets subjected to hypoxic-ischemic insult, 29 were analyzed. ScO2 and CBV were measured 0, 5, 10, 15, and 30 min after the insult. Brain tissue was histologically evaluated on day 5. ScO2 and CBV increased immediately after the insult, reached a peak, and then maintained a consistent value. The increase in CBV 5 to 30 min after the insult was significantly correlated with histopathological injury scores. However, there was no correlation with ScO2. In conclusion, an increase in CBV within 30 min after hypoxic-ischemic insult reflects the histopathological brain injury on day 5 after insult in a piglet model.

Cerebral hemoglobin oxygenation in children with congenital heart disease.

BACKGROUND: It is important to identify the pathological characteristics of cerebral circulation and oxygen metabolism at the bedside in children with congenital heart disease (CHD) to prevent neurodevelopmental impairments. The brain regional oxygen saturation index (rSO2 ) can be easily obtained at the bedside with near-infrared spectroscopy and has been widely used in the management of children with CHD in recent years. METHODS: To determine if the rSO2 before or after CHD surgery is a good predictor of cerebral oxygen metabolism, we investigated the impact of different clinical variables on the correlation between rSO2 and reference values under steady ratios of hemoglobin oxygen saturation in the internal jugular vein (SjvO2 ) or femoral artery (SaO2 ) (0.75:0.25, 0.66:0.34, and 0.50:0.50) in 186 children with CHD undergoing cardiac catheterization. RESULTS: In three patient groups-double ventricles before surgery, double ventricles after surgery, and single ventricle before surgery-there were significant relationships between rSO2 and the reference values of SO2 under all three steady ratios of SjvO2 and SaO2 . No relationship with the reference values was found for the single ventricle after surgery group. CONCLUSIONS: Regional oxygen saturation index is useful for assessing cerebral oxygenation in children with CHD, but knowledge of the underlying cardiac pathology in CHD, especially in the case of a single ventricle after surgery, is important for the correct interpretation of rSO2 measurements obtained using near-infrared spectroscopy.

Hypothermia cannot ameliorate renal fibrosis after asphyxia in the newborn piglet.

BACKGROUND: The effects of therapeutic hypothermia (TH) on renal function are not widely reported, especially in longer term animal models. The hypothesis of this study was that TH of the kidneys of hypoxic-ischemic newborn piglets would reduce pathological renal fibrosis. METHODS: Twenty-five newborn piglets obtained within 24 h of birth were classified into a control group (n = 5), an hypoxic insult with normothermia (HI-NT) group (n = 12), and an hypoxic insult with TH (HI-TH) group (33.5 °C ± 0.5 °C for 24 h; n = 8). Five days after the insult, all piglets were sacrificed under deep anesthesia by isoflurane inhalation. The kidneys were perfused with phosphate-buffered paraformaldehyde and immersed in formalin buffer. Territory fibrosis was studied and scored in the renal medulla using Azan staining. RESULTS: Fibrosis area scores (means ± standard deviations) based on Azan staining were 1.00 ± 0.46 in the control group, 2.85 ± 0.93 in the HI-NT group, and 3.58 ± 1.14 in the HI-TH group. The fibrosis area of the HI-NT and HI-TH groups was larger than that of the control. The HI-NT and HI-TH groups were not statistically different. CONCLUSIONS: Renal fibrosis is affected by perinatal asphyxia and cannot be prevented by TH, based on histopathological findings.

Cerebral hemodynamics during neonatal transition according to mode of delivery.

Cerebral haemodynamics during the immediate transition period in neonates may differ depending on whether delivery is vaginal or by caesarean section. However, these differences have never been confirmed by near-infrared time-resolved spectroscopy (TRS). Therefore, the purpose of this study was to compare cerebral blood volume (CBV) and cerebral haemoglobin oxygen saturation (ScO2) between healthy term neonates by mode of delivery. Subjects were 31 healthy term neonates who did not require resuscitation. Thirteen neonates were delivered vaginally (VD group) and 18 were delivered by elective caesarean section (CS group). Absolute oxyhaemoglobin, deoxyhaemoglobin, and total haemoglobin concentrations were measured continuously by TRS; oxyHb × 100/totalHb (ScO2) (%) and CBV (mL/100 g brain tissue) were also calculated. Measurements were started as soon as possible after birth, obtained from 1 to 2 min after birth, and continued until 15 min after birth. CBV was significantly higher in the VD group than in the CS group in the 4 min after birth but not thereafter. There were no significant between-group differences in ScO2 and SpO2. These findings indicate that there is a difference in cerebral haemodynamic patterns in the first 4 min after delivery between term neonates by mode of delivery when CBV is monitored by TRS.

Cerebral blood volume increment after resuscitation measured by near-infrared time-resolved spectroscopy can estimate degree of hypoxic-ischemic insult in newborn piglets.

Neonatal hypoxic-ischemic encephalopathy is a notable cause of neonatal death and developmental disabilities. To achieve better outcomes, it is important in treatment strategy selection to categorize the degree of hypoxia ischemia and evaluate dose response. In an asphyxia piglet model with histopathological brain injuries that we previously developed, animals survived 5 days after insult and showed changes in cerebral blood volume (CBV) that reflected the severity of injuries. However, little is known about the relationship between changes in CBV during and after insult. In this study, an HI event was induced by varying the amount and timing of inspired oxygen in 20 anesthetized piglets. CBV was measured using near-infrared time-resolved spectroscopy before, during, and 6 h after insult. Change in CBV was calculated as the difference between the peak CBV value during insult and the value at the end of insult. The decrease in CBV during insult was found to correlate with the increase in CBV within 6 h after insult. Heart rate exhibited a similar tendency to CBV, but blood pressure did not. Because the decrement in CBV was larger in severe HI, the CBV increment immediately after insult is considered useful for assessing degree of HI insult.

Intravenous Edaravone plus Therapeutic Hypothermia Offers Limited Neuroprotection in the Hypoxic-Ischaemic Newborn Piglet.

BACKGROUND: Therapeutic hypothermia (TH) is a standard therapy for neonatal hypoxic-ischaemic encephalopathy. One potential additional therapy is the free radical scavenger edaravone (EV; 3-methyl-1-phenyl-2-pyrazolin-5-one). OBJECTIVES AND METHODS: This study aimed to compare the neuroprotective effects of edaravone plus therapeutic hypothermia (TH + EV) with those of TH alone after a hypoxic-ischaemic insult in the newborn piglet. Anaesthetized piglets were subjected to 40 min of hypoxia (3-5% inspired oxygen), and cerebral ischaemia was assessed using cerebral blood volume. Body temperature was maintained at 39.0 ± 0.5°C in the normothermia group (NT, n = 8) and at 33.5 ± 0.5°C (24 h after the insult) in the TH (n = 7) and TH + EV (3 mg/kg intravenous every 12 h for 3 days after the insult; n = 6) groups under mechanical ventilation. RESULTS: Five days after the insult, the mean (standard deviation) neurological scores were 10.9 (5.7) in the NT group, 17.0 (0.4) in the TH group (p = 0.025 vs. NT), and 15.0 (3.9) in the TH + EV group. The histopathological score of the TH + EV group showed no significant improvement compared with that of the other groups. CONCLUSION: TH + EV had no additive neuroprotective effects after hypoxia-ischaemia in neurological and histopathological assessments.

Hydrogen ventilation combined with mild hypothermia improves short-term neurological outcomes in a 5-day neonatal hypoxia-ischaemia piglet model.

Despite its poor outcomes, therapeutic hypothermia (TH) is the current standard treatment for neonatal hypoxic-ischaemic encephalopathy (HIE). In this study, due to its antioxidant, anti-inflammatory, and antiapoptotic properties, the effectiveness of molecular hydrogen (H2) combined with TH was evaluated by means of neurological and histological assessments. Piglets were divided into three groups: hypoxic-ischaemic insult with normothermia (NT), insult with hypothermia (TH, 33.5 ± 0.5 °C), and insult with hypothermia with H2 ventilation (TH-H2, 2.1-2.7%). H2 ventilation and TH were administered for 24 h. After ventilator weaning, neurological assessment was performed every 6 h for 5 days. On day 5, the brains of the piglets were harvested for histopathological analysis. Regarding the neurological score, the piglets in the TH-H2 group consistently had the highest score from day 2 to 5 and showed a significantly higher neurological score from day 3 compared with the NT group. Most piglets in the TH-H2 group could walk at day 3 of recovery, whereas walking ability was delayed in the two other groups. The histological results revealed that TH-H2 tended to improve the status of cortical gray matter and subcortical white matter, with a considerable reduction in cell death. In this study, the combination of TH and H2 improved short-term neurological outcomes in neonatal hypoxic-ischaemic piglets.

Relationship between prolonged neural suppression and cerebral hemodynamic dysfunction during hypothermia in asphyxiated piglets.

OBJECTIVES: Hypothermia (HT) improves the outcome of neonatal hypoxic-ischemic encephalopathy. Here, we investigated changes during HT in cortical electrical activity using amplitude-integrated electroencephalography (aEEG) and in cerebral blood volume (CBV) and cerebral hemoglobin oxygen saturation using near-infrared time-resolved spectroscopy (TRS) and compared the results with those obtained during normothermia (NT) after a hypoxic-ischemic (HI) insult in a piglet model of asphyxia. We previously reported that a greater increase in CBV can indicate greater pressure-passive cerebral perfusion due to more severe brain injury and correlates with prolonged neural suppression during NT. We hypothesized that when energy metabolism is suppressed during HT, the cerebral hemodynamics of brains with severe injury would be suppressed to a greater extent, resulting in a greater decrease in CBV during HT that would correlate with prolonged neural suppression after insult. METHODS: Twenty-six piglets were divided into four groups: control with NT (C-NT, n = 3), control with HT (C-HT, n = 3), HI insult with NT (HI-NT, n = 10), and HI insult with HT (HI-HT, n = 10). TRS and aEEG were performed in all groups until 24 h after the insult. Piglets in the HI-HT group were maintained in a hypothermic state for 24 h after the insult. RESULTS: There was a positive linear correlation between changes in CBV at 1, 3, 6, and 12 h after the insult and low-amplitude aEEG (<5 µV) duration after insult in the HI-NT group, but a negative linear correlation between these two parameters at 6 and 12 h after the insult in the HI-HT group. The aEEG background score and low-amplitude EEG duration after the insult did not differ between these two groups. DISCUSSION AND CONCLUSION: A longer low-amplitude EEG duration after insult was associated with a greater CBV decrease during HT in the HI-HT group, suggesting that brains with more severe neural suppression could be more prone to HT-induced suppression of cerebral metabolism and circulation.

Amounts and compositional analysis of glycosaminoglycans in the tissue of fish.

We isolated GAGs from the inedible parts; head, skin, internal organs, fins, scales and spine, of atlantic mackerel (Scomber scombrus), japanese jack mackerel (Trachurus japonicus), pacific bluefin tuna (Thunnus orientalis), yellowfin sole (Limanda aspera), broadbanded thornyhead (Sebastolobus macrochir), golden threadfin bream (Nemipterus virgatus), and nile tilapia (Oreochromis niloticus). We also investigated deep-sea fish, eelpouts (Bothrocara hollandi, Lycodes toyamensis, and Lycodes nakamurae), rough snailfish (Careproctus trachysoma), and squids (Watasenia scintillans, Enoploteuthis chunii, and Berryteuthis magister). Enzymatic digestion of the GAGs enabled a compositional analysis of CS, DS, and HA including the sulfation patterns of CS and DS, as well as the amount of each GAG. The molecular weights and distributions of these GAGs were also examined. The amounts of GAGs contained in the tissues and CS/DS ratios differed remarkably among the fish. The dorsal fin of the yellowfin sole contained more than 1300mg of CS-DS per 100g of defatted-dry tissue. Although the fish generally contained A-type rich CS-DS, bottom fish and deep-sea fish often possessed C-type CS-DS in larger ratios. Squid characteristically had E-type CS-DS which was normally less common in fish except in cartilaginous fish. These analytical results had no relation to the biological classification.

Synthesis and interaction with midkine of biotinylated chondroitin sulfate tetrasaccharides.

Regiospecifically sulfated chondroitin sulfate repeating tetrasaccharides, CS-OO, GlcAß-GalNAcß-GlcAß-GalNAcß;CS-EE, GlcAß-GalNAc(4S6S)ß-GlcAß-GalNAc(4S6S)ß; and CS-AA, GlcAß-GalNAc(4S)ß-GlcAß-GalNAc(4S)ß, having biotin linked with a hydrophilic linker at the reducing terminal were synthesized effectively by a coupling of the corresponding disaccharide units and regioselective sulfation. CS-EE showed greater affinity for midkine than CS-AA and CS-OO.