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.

An enriched environment ameliorates the reduction of parvalbumin-positive interneurons in the medial prefrontal cortex caused by maternal separation early in life

Early child maltreatment, such as child abuse and neglect, is well known to affect the development of social skills. However, the mechanisms by which such an adverse environment interrupts the development of social skills remain unelucidated. Identifying the period and brain regions that are susceptible to adverse environments can lead to appropriate developmental care later in life. We recently reported an excitatory/inhibitory imbalance and low activity during social behavior in the medial prefrontal cortex (mPFC) of the maternal separation (MS) animal model of early life neglect after maturation. Based on these results, in the present study, we investigated how MS disturbs factors related to excitatory and inhibitory neurons in the mPFC until the critical period of mPFC development. Additionally, we evaluated whether the effects of MS could be recovered in an enriched environment after MS exposure. Rat pups were separated from their dams on postnatal days (PDs) 2-20 (twice daily, 3 h each) and compared with the mother-reared control (MRC) group. Gene expression analysis revealed that various factors related to excitatory and inhibitory neurons were transiently disturbed in the mPFC during MS. A similar tendency was found in the sensory cortex; however, decreased parvalbumin (PV) expression persisted until PD 35 only in the mPFC. Moreover, the number of PV+ interneurons decreased in the ventromedial prefrontal cortex (vmPFC) on PD 35 in the MS group. Additionally, perineural net formation surrounding PV+ interneurons, which is an indicator of maturity and critical period closure, was unchanged, indicating that the decreased PV+ interneurons were not simply attributable to developmental delay. This reduction of PV+ interneurons improved to the level observed in the MRC group by the enriched environment from PD 21 after the MS period. These results suggest that an early adverse environment disturbs the development of the mPFC but that these abnormalities allow room for recovery depending on the subsequent environment. Considering that PV+ interneurons in the mPFC play an important role in social skills such as empathy, an early rearing environment is likely a very important factor in the subsequent acquisition of social skills.

Developmental changes in neonatal hemodynamics during tactile stimulation using whole-head functional near-infrared spectroscopy

Neural-activity-associated hemodynamic changes have been used to noninvasively measure brain function in the early developmental stages. However, the temporal changes in their hemodynamics are not always consistent with adults. Studies have not evaluated developmental changes for a long period using the same stimuli; therefore, this study examined the normalized relative changes in oxygenated hemoglobin (Δ[oxy-Hb]) in full-term infants and compared them with neonates up to 10 months of age during the administration of tactile vibration stimuli to their limbs using whole-head functional near-infrared spectroscopy. The time to peak of normalized Δ[oxy-Hb] was not affected by age. The amplitude of normalized Δ[oxy-Hb] showed an effect of age in broader areas, including sensorimotor-related but excluding supplementary motor area; the amplitude of normalized Δ[oxy-Hb] decreased the most in the 1-2-month-old group and later increased with development. We hypothesized that these results may reflect developmental changes in neural activity, vasculature, and blood oxygenation.

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.

Serum caffeine concentrations in preterm infants: a retrospective study

Therapeutic drug monitoring is generally unnecessary in caffeine treatment for apnea of prematurity, as serum caffeine concentrations in preterm infants are normally markedly lower than those at which caffeine intoxication occurs. However, several studies have reported preterm infants having developed toxicity. This retrospective observational study, conducted at a tertiary center in Kagawa, Japan, aimed to evaluate the correlation between the maintenance dose and serum caffeine concentrations and determine the maintenance dose leading to suggested toxic caffeine levels. We included 24 preterm infants (gestational age, 27 ± 2.9 weeks; body weight, 991 ± 297 g) who were treated with caffeine citrate for apnea of prematurity between 2018 and 2021, and 272 samples were analyzed. Our primary outcome measure was the maintenance dose leading to suggested toxic caffeine levels. We found a positive correlation between caffeine dose and serum caffeine concentrations (p < 0.05, r = 0.72). At doses of ≥ 8 mg/kg/day, 15% (16/109) of patients had serum caffeine concentrations above the suggested toxic levels. Patients who receive doses ≥ 8 mg/kg/day risk reaching the suggested toxic serum caffeine levels. It remains unclear whether suggested toxic caffeine concentrations are detrimental to neurological prognosis. Further investigation is required to understand the clinical effects/outcomes of high serum levels of caffeine and to obtain long-term neurodevelopmental follow-up data.

Developmental changes in visual-cognitive and attentional functions in infancy

BACKGROUND

Identifying developmental changes in visual-cognitive and attentional functions during infancy may lead to early diagnosis of neurodevelopmental disorders such as ASD and ADHD.

AIMS

To clarify the developmental changes in visual-cognitive and attentional functions during infancy (3-36 months of age).

STUDY DESIGN

Cross-sectional study.

SUBJECTS

We included 23, 24, 31, and 26 participants aged 3, 9, 18, and 36 months, respectively (full-term births). Fifteen children who cried intensely or whose data could not be accurately recorded were excluded.

OUTCOME MEASURES

Three activities were given to each child while they were seated in front of a gaze-tracking device to evaluate re-gaze, motion transparency, and color-motion integration. We analyzed whether the child's attention shifted to the new stimulus in their peripheral vision in the re-gaze task. In the motion transparency and color-motion integration tasks, two images were presented simultaneously on the screen. In the motion transparency task, participants preferred random dots moving in opposite directions; in the color-motion task, they preferred subjective contours from apparent motion stimuli consisting of random red and green dots with different luminance.

RESULTS

In the re-gaze task, fewer 3-month-olds gazed at the new target than other age groups participants. All ages showed preference for target stimuli in the motion transparency task, but 3-month-olds showed significantly lower preference in the color-motion integration task.

CONCLUSION

These tasks may be useful for measuring visual-cognitive and attentional functions in infants.

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.

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

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

The Trajectory of Expressed Colostrum Volume in the First 48 Hours Postpartum: An Observational Study

Objective: Colostrum, the first form of human milk, is strongly encouraged for infants due to its benefits. During the early postpartum (PP) period, the secreted colostrum volume can be minimal, causing concerns among mothers about sufficient milk supply. Few studies have examined temporal changes in the colostrum. This study aimed to elucidate the trajectory of expressed colostrum volume in the first 48 hours after delivery. Materials and Methods: This was a cross-sectional observational study performed at Kagawa National Children's Hospital. One hundred five mothers who did not directly breastfeed in the first 48 hours after delivery were enrolled in the study. Well-trained midwives instructed the mothers on how to express human milk, and mothers started to express as soon as possible after delivery. Mothers were advised to express human milk every 3 hours, and the milk volume was measured. Results: Within 3 hours PP, 60% of mothers expressed milk, and the median frequency of expression was 14 (interquartile range, 11-16) times in the first 48 hours. At 0-3 and 3-6 hours PP, the volume of initially expressed milk was 0.4 (0.0-2.0) mL and 1.0 (0.0-6.0) mL, respectively. Subsequently, milk volume decreased. The volume remained low until 30 hours PP and increased dramatically; this phenomenon is termed secretory activation, which began later in primiparous women than in multiparous women. Conclusion: The decline in expressed milk volume during the early PP period caused concern among mothers. Therefore, mothers should be informed of the PP trajectory of human milk volume.

Transcutaneous bilirubin-based screening reduces the need for blood exchange transfusion in Myanmar newborns: A single-center, retrospective study

BACKGROUND

Neonatal hyperbilirubinemia is a significant health problem in Myanmar. We introduced transcutaneous bilirubin (TcB) measurements in 2017 and developed an hour-specific TcB nomogram for early detection and treatment of hyperbilirubinemia in Myanmar neonates. This study aimed to evaluate whether our screening method for hyperbilirubinemia decreased the requirement of blood exchange therapy (ET).

METHODS

This retrospective cohort study was conducted at the Central Women's Hospital, Yangon. Two groups were included as follows: group 1 (control group; comprising infants born in 2016 and screened on the basis of Kramer's rule), and group 2 (intervention group; comprising infants born in 2019 and screened by TcB measurement using a nomogram). The number of ETs was analyzed based on causes of hyperbilirubinemia and number of days after birth.

RESULTS

Groups 1 and 2 comprised 12,968 and 10,090 infants, respectively. Forty-six and two infants in Groups 1 and 2, respectively, required an ET. The odds ratio for ET was 18.0 (Group 1 to Group 2; 95% confidence interval [CI]: 4.8-67.1; p = 0.000). Serum bilirubin values at the time ET was administered were significantly higher in Group 1 than those in Group 2 (median: 23.0 and 16.8, respectively).

CONCLUSION

The management of hyperbilirubinemia using our screening method (TcB Nomogram) can effectively reduce the need for ET in neonates in Myanmar.

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.

Fetal and neonatal bilirubin metabolism

Human fetal and neonatal bilirubin metabolism is centered on 4Z,15Z-bilirubin IXα (BR) due to the extremely low BR conjugating capacity of the liver. BR is a unique, highly lipophilic substance with physiological and toxic effects in the cell membranes of organs and body tissues. The fetus excretes BR through the placenta to the maternal circulation. After birth, BR is thought to act as an antioxidant against the increase in reactive oxygen species caused by the rapid increase in oxygen concentration during the adaptation process from in amniotic fluid to in air. However, bilirubin encephalopathy is a toxic effect of bilirubin. Due to the lipophilic nature of BR, it must be bound to a carrier to be distributed to various parts of the body by hydrophilic blood. This carrier of BR is human serum albumin (HSA). In humans, BR can be excreted efficiently after undergoing photochemical reactions upon high affinity binding to HSA. HSA also plays an important role in the prevention of bilirubin encephalopathy. This review focuses on the developmental and physiological role of bilirubin metabolism during the fetal and neonatal periods.

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.

Effects of bilirubin configurational photoisomers on the measurement of direct bilirubin by the vanadate oxidation method

BACKGROUND

Direct-reacting bilirubin concentrations measured using vanadate chemical oxidation method do not exactly match the conjugated bilirubin concentration. One of the causes is the effect of bilirubin photoisomers. However, the quantitative evaluation of the effects of these photoisomers has not been sufficiently conducted. In particular, the influence of bilirubin configurational isomers on direct bilirubin is the most critical factor.

METHODS

Sixteen residual serum samples were used. For quantitative analysis based on the change in direct bilirubin and bilirubin configurational isomer, samples were irradiated via blue light-emitting diodes to suppress the production of bilirubin structural isomers. Total bilirubin and direct bilirubin concentrations were measured using the vanadate chemical oxidation method. Concentrations of 4Z,15Z-bilirubin IXα and its photoisomers were measured using high-performance liquid chromatography. The sum of 4Z,15E-bilirubin IXα and 4E,15Z-bilirubin IXα was notated as bilirubin configurational isomer, and the differences between the measured values of the irradiated and non-irradiated samples were calculated and notated as ΔDB and ΔBCI.

RESULTS

In non-irradiated and irradiated samples, total bilirubin and direct bilirubin concentrations were 10.73 mg/dL with significant a decrease to 10.60 mg/dL and 0.69 mg/dL with a significant increase to 0.78 mg/dL, while bilirubin configurational isomer values were 1.00 mg/dL and 1.52 mg/dL, respectively. The linear regression equation revealed a significant positive correlation of Y = 0.187X-0.006 between ΔDB (Y) and ΔBCI (X).

CONCLUSION

Applying the vanadate chemical oxidation method affected approximately 19% of the bilirubin configurational isomer concentration for direct bilirubin. Extreme caution is necessary when interpreting the measured values of samples indicative of unconjugated hyperbilirubinaemia.

Do low birth weight infants not see eyes? Face recognition in infancy

BACKGROUND

Progress in neonatal medicine has dramatically improved the survival rate of preterm births, but the evidence suggests that these low-birth weight infants (LBWIs) go on to develop pervasive development disorders and attention deficit hyperactivity disorder (ADHD) at greater rates than the general population. Children with neurodevelopmental disorders are known to suffer from deficits in visual cognition, such as in face perception and attentional functions, the characteristics of which already manifest in early infancy.

PURPOSE

This study aimed to investigate visual cognition in LBWIs during infancy.

SUBJECTS

20 LBWIs and 20 normal-birth-weight infants (NBWIs: control) of age 9-10 months (corrected age was used for LBWIs).

METHOD

Children were held seated in front of an eye tracking system by a parent, and presented with facial photos as visual stimuli. During the familiarization phase, the child was presented with two images of the same human face (familiarization stimulus) on the left and right side of a display screen (5 × 10 s trials). Next, during the test phase, the child was presented with the same image on one side of the screen, and a photo of a different person's face (novel stimulus) on the other (2 × 5 s trials). Gaze behavior was assessed in terms of the total time spent looking at either facial stimulus, and specifically at the eyes of the stimuli, as well as the number of attentional shifts between stimuli, and novelty preference.

RESULTS/DISCUSSION

LBWIs spent significant less time looking at facial stimuli overall, and less time at the eye region, than NBWIs. These findings seem to evidence developmental differences in functions related to visual cognition.

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.

Effect of psychotropic drugs on fetal behavior in the third trimester of pregnancy

AIM

To assess the effect of psychotropic drugs on fetal behavior using four-dimensional (4D) ultrasound in the third trimester of pregnancy.

METHODS

Fetal behavior was assessed using Kurjak's antenatal neurodevelopmental test (KANET) using 4D ultrasound between 28 and 36 weeks of gestation. Thirty healthy (control group) and 10 psychotropic-drug-administered pregnant (case group) women were studied. The total value of the KANET score and values of each parameter (eight parameters) were compared between the two groups.

RESULTS

The total KANET score was normal (except for one fetus in the case group: total score of 9) in both groups, and there was no significant difference in the total KANET score. When individual KANET parameters were compared, no significant differences were noted in any of the eight parameters.

CONCLUSION

Our results showed that there is no difference in fetal behavior between fetuses of normal pregnant women and those of psychotropic-drug-administered pregnant women in the third trimester of pregnancy. These results suggest that psychotropic drugs may not affect fetal behavioral development in utero. However, the data and their interpretation in the present study should be taken with some degree of caution because of the small number of subjects studied. Further studies involving a larger sample size are needed to assess the effect of psychotropic drugs on fetal neurobehavior during pregnancy.

Prediction of postnatal developmental disabilities using the antenatal fetal neurodevelopmental test: KANET assessment

Objective To assess the usefulness of the antenatal fetal neurodevelopmental test for the prediction of postnatal developmental disabilities. Methods Fetal behavior was assessed with Kurjak's antenatal neurodevelopmental test (KANET) using four-dimensional ultrasound between 28 and 38 weeks of gestation. A score range of 0-5 was characterized as abnormal, from 6 to 9 was considered borderline, and 10-16 was normal. After birth, follow-up was conducted for at least 2 years in all fetuses. Results There were 337 normal (95.47%) and 16 borderline (4.53%) cases among the 353 cases studied, whereas there was no abnormal case. Five cases with postnatal developmental disabilities (one case of Werdig-Hoffmann disease diagnosed just after delivery, one case of autism spectrum disorder diagnosed at 24 months, one case of Ullrich congenital muscular dystrophy diagnosed at 9 months and two cases of developmental disorders diagnosed at age 3 and 18 months) were noted among the 337 normal cases (1.48%), whereas three cases with developmental disabilities (one case of motor development delay diagnosed at 6 months, one case of Duchenne muscular dystrophy diagnosed at 18 months and one case of autism spectrum disorder diagnosed at age 30 months) were found among the 16 borderline cases (18.75%). There was a significant difference in the prevalence of postnatal developmental disabilities between the normal and borderline KANET groups (P<0.001). Conclusion Our results suggest that the KANET assessment may be a useful diagnostic modality for the prediction of postnatal developmental disabilities.

International consensus on the assessment of bruxism: Report of a work in progress

In 2013, consensus was obtained on a definition of bruxism as repetitive masticatory muscle activity characterised by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible and specified as either sleep bruxism or awake bruxism. In addition, a grading system was proposed to determine the likelihood that a certain assessment of bruxism actually yields a valid outcome. This study discusses the need for an updated consensus and has the following aims: (i) to further clarify the 2013 definition and to develop separate definitions for sleep and awake bruxism; (ii) to determine whether bruxism is a disorder rather than a behaviour that can be a risk factor for certain clinical conditions; (iii) to re-examine the 2013 grading system; and (iv) to develop a research agenda. It was concluded that: (i) sleep and awake bruxism are masticatory muscle activities that occur during sleep (characterised as rhythmic or non-rhythmic) and wakefulness (characterised by repetitive or sustained tooth contact and/or by bracing or thrusting of the mandible), respectively; (ii) in otherwise healthy individuals, bruxism should not be considered as a disorder, but rather as a behaviour that can be a risk (and/or protective) factor for certain clinical consequences; (iii) both non-instrumental approaches (notably self-report) and instrumental approaches (notably electromyography) can be employed to assess bruxism; and (iv) standard cut-off points for establishing the presence or absence of bruxism should not be used in otherwise healthy individuals; rather, bruxism-related masticatory muscle activities should be assessed in the behaviour's continuum.

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.

Bilirubin photoisomers in rhesus monkey serum

As rhesus monkeys exhibit physiological jaundice during the neonatal period, we used rhesus monkey serum to examine changes in bilirubin photoisomers. Bilirubin-rhesus monkey serum solution was irradiated with blue light-emitting diode, and changes in the absorbance and bilirubin fraction were compared with those in bilirubin- human serum albumin (HSA) and bilirubin-rat albumin solutions. The λ_max decreased with light irradiation. The mean production rate of cyclobilirubin IXα was 1.98, 199 and 0.76 × 10^-2/min in rhesus monkey serum, HSA and rat albumin, respectively. There was no significant difference between rhesus monkey serum and HSA. The (ZE)-bilirubin IXα/(ZZ)-bilirubin IXα ratio was 0.33, 0.45, and 0.10, respectively, differing significantly among the groups. The (EZ)-bilirubin IXα/(ZZ)-bilirubin IXα ratio was 0.020, 0.010, and 0.062, respectively, with no significant difference between rhesus monkey serum and HSA. The production rate of (EZ)-cyclobilirubin XIIIα(= (ZE)-cyclobilirubin XIIIα) was 0.73, 1.60, and 0.51 × 10^-2/min, respectively, with differing significantly among the groups. The (EZ)-bilirubin IIIα/(ZZ)-bilirubin IIIα ratio was significantly different among the groups at 0.20, 0.38, and 0.15, respectively. This is the first report demonstrating the photoisomerization of bilirubin in rhesus monkey serum and the animal with the same cyclobilirubin production rate as HSA.Rhesus monkeys may be used as an animal model for neonatal hyperbilirubinemia in humans to evaluate the efficacy of phototherapy.

Human tRNA-Derived Small RNAs Modulate Host-Oral Microbial Interactions

Coevolution of the human host and its associated microbiota has led to sophisticated interactions to maintain a delicate homeostasis. Emerging evidence suggests that in addition to small molecules, peptides, and proteins, small regulatory noncoding RNAs (sRNAs) might play an important role in cross-domain interactions. In this study, we revealed the presence of diverse host transfer RNA-derived small RNAs (tsRNAs) among human salivary sRNAs. We selected 2 tsRNAs (tsRNA-000794 and tsRNA-020498) for further study based on their high sequence similarity to specific tRNAs from a group of Gram-negative oral bacteria, including Fusobacterium nucleatum, a key oral commensal and opportunistic pathogen. We showed that the presence of F. nucleatum triggers exosome-mediated release of tsRNA-000794 and tsRNA-020498 by human normal oral keratinocyte cells. Furthermore, both tsRNA candidates exerted a growth inhibition effect on F. nucleatum, likely through interference with bacterial protein biosynthesis, but did not affect the growth of Streptococcus mitis, a health-associated oral Gram-positive bacterium whose genome does not carry sequences bearing high similarity to either tsRNA. Our data provide the first line of evidence for the modulatory role of host-derived tsRNAs in the microbial-host interaction.

Effects of bilirubin photoisomers on the measurement of direct bilirubin by the bilirubin oxidase method

Background

We occasionally encounter increases in direct bilirubin value on reanalysis of the surplus serum collected in the past from a neonate with indirect hyperbilirubinemia. But the details of this phenomenon are unclear. We evaluated the change of direct bilirubin and the relation of bilirubin photoisomer of the serum exposed to room light.

Methods

Surplus serum samples from neonates with indirect hyperbilirubinemia were exposed to room light for 24 h. The bilirubin fraction assay of samples was performed by the bilirubin oxidase method (Nescauto and Aqua-auto Kainos reagent) and high-performance liquid chromatography.

Results

Direct bilirubin increased significantly from 0.61 to 2.36 mg/dL. The respective ratios of bilirubin photoisomers before and after exposure were as follows: cyclobilirubin (0.007 to 0.29) and (EZ)-bilirubin (0.018 to 0.041) increased significantly, (ZZ)-bilirubin decreased 0.84 to 0.55 significantly. The difference of the cyclobilirubin concentration was most closely associated with those of the direct bilirubin concentration.

Conclusion

Direct bilirubin value was increased after exposure to the room light, and increase in direct bilirubin was significantly correlated by cyclobilirubin increase in the serum samples from neonates with indirect hyperbilirubinemia.

Antenatal diagnosis of idiopathic dilatation of pulmonary artery with 3D power doppler imaging

We present a case of antenatal diagnosis of idiopathic dilatation of the pulmonary artery by three-dimensional power Doppler imaging (HDliveFlow with silhouette mode). Two-dimensional sonography clearly demonstrated a 10.4-mm-diameter fetal pulmonary artery (PA), whereas the aorta (Ao) diameter was 5.04 mm. HDliveFlow clearly demonstrated the spatial relationships and different sizes of PA and Ao. The PA size returned to normal (8.0 mm) on the 11th day after birth (Ao: 9.0 mm). HDliveFlow may be an adjunctive tool to two-dimensional sonography to diagnose abnormalities of fetal great vessels. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:121-123, 2017.

Peripheral nerve crushing to relieve chronic pain in diabetic and ischaemic foot ulcers

OBJECTIVE

We retrospectively assessed the effectiveness of peripheral nerve crushing (Smithwick operation) in relieving intractable chronic pain associated with foot ulcers caused by diabetes mellitus (DM) or atherosclerosis.

METHOD

From April 2009 to April 2012, patients underwent peripheral nerve crushing in the leg affected by foot ulceration. The cause of ulceration was either DM alone, atherosclerosis alone, or both DM and atherosclerosis. Because sensation in the foot is associated with five nerves: the tibial, deep peroneal, superficial peroneal, sural, and saphenous, one or more of these nerves were crushed over a length of 1.5cm by using a 'pean' in the distal third of leg the where there are no major motor nerves.

RESULTS

There were 36 patients recruited with ulcers grade 3-5 according to the Wagner ulcer classification system that affected the toes, dorsum pedis, or any part of the plantar surface or the heel. The mean duration of foot ulcerations before the nerve crushing was 22.3±9.7 weeks. In all 36 patients, the nerve crushing was performed successfully without any perioperative surgical complication. Of the 36 patients, 34 (94.4%) had substantial pain relief immediately after nerve crushing. While the mean pain level before the procedure was 86.6±0.51mm on visual analogue scale (VAS), pain level dropped significantly after the operation to 18.6 ± 5.4mm at one week, 14.8±4.8mm at one month, 13.7±4.1mm at two months, 9.8±4.1mm at three months, 11.8±5.7mm at four months, 10.1±4.7mm at five months and 8.8±3.3mm at six months. The time to regeneration of the sensory nerves was 121±6.5 days (range: 80-181 days). The surgical complications were wound infection (6 patients) and temporary toe paralysis (three patients). The foot ulcers in 20 of the 36 patients (55.6%) were resolved by debridement or minor amputation. In seven patients (19.4%), a major amputation (five below and two above the knee) was required because of ischemia or infection. No patient died within 30 days of the operation, while nine patients died during the observation period because of comorbid conditions.

CONCLUSION

Peripheral nerve crushing could be the alternative procedure for achieving analgesia in patients with intractable chronic pain from foot ulcers caused by DM or atherosclerosis.

Hypoxic-Ischemic Encephalopathy-Associated Liver Fatty Degeneration and the Effects of Therapeutic Hypothermia in Newborn Piglets

BACKGROUND

Although liver can be injured under the hypoxic-ischemic encephalopathy (HIE) condition, there is currently no histopathological evidence. Therapeutic hypothermia is used to protect the brain; however, the therapeutic potential for concomitant liver injury is unknown.

OBJECTIVES

This study aimed to histopathologically prove HIE-associated liver injury and to investigate the influence of therapeutic hypothermia in a newborn piglet HIE model.

METHODS

Eighteen newborn piglets were divided into 3 groups: control (n = 4), HIE (n = 8), and therapeutic hypothermia (n = 6) groups. The hypoxic insult was induced by decreasing the fraction of inspiratory oxygen from 21 to 2-4% over 40 min while monitoring cerebral blood volume and cerebral hemoglobin oxygen saturation. For therapeutic hypothermia, whole-body cooling at 33-34°C was administered for 24 h after the hypoxic insult. We hematologically and histopathologically investigated the liver injury in all groups.

RESULTS

Alanine transaminase and lactate dehydrogenase levels in the HIE group were significantly elevated compared with those in the control group. Micro-lipid droplet accumulation in the periportal zone, but not in the perivenous zone, was significantly greater in the HIE group than in the control group and significantly smaller in the therapeutic hypothermia group than in the HIE group.

CONCLUSIONS

We demonstrated that micro-lipid droplet accumulation in the cytoplasm of hepatocytes in the periportal zone occurs under the HIE condition and that this accumulation is suppressed by therapeutic hypothermia.

Surgery for gastroesophageal reflux disease with Gaucher disease type 2

Gaucher disease, the most common lysosomal storage disease, is sometimes complicated with gastroesophageal reflux disease (GERD). The present patient was a 136-day-old Japanese boy with Gaucher disease type 2. Enzyme replacement therapy and chemical chaperone therapy were successful for the skin disorders, joint contractures, hepatosplenomegaly and thrombocytopenia, but he also had GERD. Accordingly, a Nissen fundoplication with gastrostomy was performed. There was no vulnerability of organs, easy bleeding or difficulty of maintaining the visual field because of hepatosplenomegaly during operation. In the perioperative period, there was no prolonged wound healing or infection. GERD was improved. In the near future, the number of long-term survivors of Gaucher disease will increase due to improvements in medical therapy. Therefore, it is expected that the number of patients requiring fundoplication will also increase. In patients with successful medical therapy, surgical fundoplication can be safely and effectively performed.

Simultaneous measurement of cerebral hemoglobin oxygen saturation and blood volume in asphyxiated neonates by near-infrared time-resolved spectroscopy

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) usually results in a poor clinical outcome even when treated with hypothermic therapy (HT). Early postnatal changes in cerebral blood oxygenation and hemodynamics may be critical determinants of brain injury and the efficacy of HT.

OBJECTIVES

We measured cerebral hemoglobin oxygen saturation (ScO2) and cerebral blood volume (CBV) by near-infrared time-resolved spectroscopy (TRS) in HT-treated and non-HT-treated neonatal HIE patients to assess the influence of these parameters on clinical outcome.

METHODS

We retrospectively compared ScO2, CBV, and clinical outcomes of 11 neonates with HIE: 5 were treated by HT (HT-treated; 33.5°C±0.5°C for 72h starting approximately 6h after delivery) and 6 were not (non-HT-treated). Both CBV and ScO2 were measured by TRS at 6, 24, 48, and 72h after birth. Magnetic resonance imaging (MRI) was performed 1-2weeks after birth to assess brain injury.

RESULTS

Five neonates had adverse outcomes (3 HT-treated, 2 non-HT-treated). Of these, 1 died within 3days of birth and 4 had abnormal MRI findings, including basal ganglia, white matter, and/or thalamic lesions. The other 6 neonates had normal MRI findings (favorable outcome). At 6h after birth, CBV was significantly higher in neonates with adverse outcomes compared with those with a favorable outcome. At 24h after birth, ScO2 was significantly higher in neonates with adverse outcomes. Furthermore, we found that combined CBV at 24h after birth plus ScO2 had the best predictive ability for neurological outcome: sensitivity, specificity, positive predictive value, and negative predictive value were all 100%.

CONCLUSION

Early postnatal CBV and ScO2 elevations were predictive of a poor outcome in HIE. Therefore, measuring combined CBV plus ScO2 at 24h after birth can allow more precise prediction of neurological outcome. Control of postnatal CBV and ScO2 is critical for effective HIE treatment.

Cerebral blood volume measurement using near-infrared time-resolved spectroscopy and histopathological evaluation after hypoxic-ischemic insult in newborn piglets

The aim of this study was to assess the relationship between the cerebral blood volume (CBV) measured by near-infrared time-resolved spectroscopy (TRS) and pathological change of the brain in a hypoxic-ischemic (HI) piglet model. Twenty-one anesthetized newborn piglets, including three sham controls, were studied. An HI event was induced by low inspired oxygen. CBV was measured using TRS (Hamamatsu TRS-10). Data were collected before, during, and 6h after the insult. CBV was calculated as the change from the end of the insult. The piglets were allowed to recover from anesthesia for 6h after the insult. At the age of 5 days, the brains of the piglets were perfusion-fixed, and histologic evaluations of brain tissue were performed. The extent of histopathological damage was graded in 0.5-unit intervals on a 9-step scale. CBV increments were well correlated with histopathological scores, especially at 1 and 3h after resuscitation. Spearman's rank-correlation coefficients at 1, 3, and 6h after resuscitation in the gray matter were 0.9016, 0.9127, and 0.6907, respectively. We conclude that an increased CBV after HI insult indicates more marked histological brain damage. CBV measurement immediately after resuscitation provides a more precise prediction of the histological outcome.

Occlusion on oral implants: current clinical guidelines

Proper implant occlusion is essential for adequate oral function and the prevention of adverse consequences, such as implant overloading. Dental implants are thought to be more prone to occlusal overloading than natural teeth because of the loss of the periodontal ligament, which provides shock absorption and periodontal mechanoreceptors, which provide tactile sensitivity and proprioceptive motion feedback. Although many guidelines and theories on implant occlusion have been proposed, few have provided strong supportive evidence. Thus, we performed a narrative literature review to ascertain the influence of implant occlusion on the occurrence of complications of implant treatment and discuss the clinical considerations focused on the overloading factors at present. The search terms were 'dental implant', 'dental implantation', 'dental occlusion' and 'dental prosthesis'. The inclusion criteria were literature published in English up to September 2013. Randomised controlled trials (RCTs), prospective cohort studies and case-control studies with at least 20 cases and 12 months follow-up interval were included. Based on the selected literature, this review explores factors related to the implant prosthesis (cantilever, crown/implant ratio, premature contact, occlusal scheme, implant-abutment connection, splinting implants and tooth-implant connection) and other considerations, such as the number, diameter, length and angulation of implants. Over 700 abstracts were reviewed, from which more than 30 manuscripts were included. We found insufficient evidence to establish firm clinical guidelines for implant occlusion. To discuss the ideal occlusion for implants, further well-designed RCTs are required in the future.

Relationship between early changes in cerebral blood volume and electrocortical activity after hypoxic-ischemic insult in newborn piglets

BACKGROUND

Early changes in cerebral hemodynamics and depressed electrocortical activity have been reported after a hypoxic-ischemic (HI) insult. However, the relationship between these two parameters is unclear. This study aimed to examine the relationship between changes in cerebral blood volume (CBV) and cerebral Hb oxygen saturation (ScO2) after a HI insult and the low amplitude-integrated electroencephalography (aEEG) duration concomitantly observed.

METHODS

Sixteen newborn piglets obtained within 24h of birth were used (n=3 controls). Thirteen piglets were subjected to a HI insult of 20-min low-amplitude aEEG (<5 μV, LAEEG), after which a low mean arterial blood pressure (<70% of baseline) was maintained for 10 min. We measured changes in CBV and ScO2 using near-infrared time-resolved spectroscopy (TRS) and cerebral electrocortical activities using aEEG until 6h after the insult.

RESULTS

A positive correlation was observed between the LAEEG duration and CBV increase, but not ScO2, after the insult.

CONCLUSION

These results suggest that a larger increase in CBV reflected a more severe failure in cerebral circulation to maintain cell membrane action potentials, which induced a more extended recovery period of electrocortical activity after the insult. We conclude that an early increase in CBV and longer LAEEG indicate severe brain injury.

HDlive imaging of fetal enteric duplication cyst

Enteric duplication cysts are rare congenital anomalies, but their antenatal diagnosis is becoming more common because of advances in ultrasonography. With the latest state-of-the-art technology, HDlive facilitates a more realistic anatomical visualization of different fetal organ structures, making diagnosis more precise. We present a case of antenatal HDlive imaging of an enteric duplication cyst. A 26-year-old pregnant Japanese woman was referred to our ultrasound clinic because of a fetal intra-abdominal cyst at 27 weeks of gestation. Two-dimensional (2D) ultrasound revealed a sonolucent, ellipsoid structure in the subhepatic area. Magnetic resonance imaging yielded the same findings. However, irregular internal echoes appeared at 33 weeks of gestation. There was no vascularity on color Doppler. HDlive clearly depicted a more realistic image of the circular mass, which was thick walled, with a large amount of debris inside, and showed no communication with adjacent structures. Careful monitoring was conducted for these unusual findings. A day after delivery, an emergency operation was performed because the infant had sudden signs and symptoms of obstruction. Intra-operative findings were ileus and a necrotic ileal duplication cyst confirmed by histopathologic studies. Complications of enteric duplication cyst can arise at any time of life, and so thorough monitoring may be recommended. The findings of irregular internal echoes and a large amount of debris inside the cyst are relatively characteristic features of a complicated cyst. HDlive gives us additional information on the actual appearance of a complicated cyst that may be difficult to obtain using conventional 2D sonography alone. HDlive can be very useful in the antenatal surveillance of enteric duplication cysts.

Cerebral blood volume combined with amplitude-integrated EEG can be a suitable guide to control hypoxic/ischemic insult in a piglet model

INTRODUCTION

The purposes of this study are to compare two hypoxic/ischemic (H/I) insults using amplitude-integrated EEG (aEEG), alone or combined with cerebral blood volume (CBV), as a guide to control hypoxia and to determine which protocol most effectively produces a consistent degree of survivable neuropathological damage in a newborn piglet model of perinatal asphyxia.

METHODS

Eighteen piglets were subjected to H/I insult of 20-min low aEEG (LAEEG). After the 20-min, the aEEG group was maintained with low mean arterial blood pressure for 10min. The procedure for the aEEG plus CBV group was stopped if CBV became the rated value after 20min of LAEEG. We measured changes in CBV using a near-infrared time-resolved spectroscopy (TRS) and cerebral electrocortical activity using aEEG until 6h post-insult. At 5days post insult, the piglets' brains were perfusion-fixed and stained with hematoxylin/eosin. Piglets were grouped as undamaged or damaged; piglets that did not survive to 5days were grouped separately as dead.

RESULTS

Among surviving piglets, CBV combined with aEEG resulted in significantly greater percentage of damaged piglets than aEEG alone.

CONCLUSIONS

We conclude that combining CBV with aEEG may be a more effective guide to control H/I insult in a newborn piglet model than aEEG alone.

Extrauterine environment influences spontaneous low-frequency oscillations in the preterm brain

Low-frequency oscillations in cerebral blood flow that are suggestive of resting-state brain activity have recently been reported, but no study on the development of resting-state brain activity in preterm infants has been performed. The objective of this study was to measure the cerebral blood flow oscillations, which are assumed to represent brain function in the resting state, in preterm and term infants of the same postconceptional age. The subjects were 9 preterm infants who had reached full term (gestational age (GA): 23-34 weeks, postconceptional age: 37-46 weeks) and 10 term infants (GA: 37-40 weeks, postconceptional age: 37-41 weeks). Their changes in concentration of oxyhemoglobin ([oxyHb]) and deoxyhemoglobin ([deoxyHb]) were measured in the parieto-temporal region during quiet sleep using multi-channel near-infrared spectroscopy, and the power spectral densities (PSD) of the oscillations in the concentrations of these molecules were analyzed and compared. The preterm infants displayed a higher proportion of 0.06-0.10 Hz low frequency oscillations of [oxyHb] and [deoxyHb] than the term infants, and the gestational age and the proportion of low frequency oscillations were inversely correlated. These findings suggest that resting-state cerebral blood flow oscillations differ between preterm and term infants, and that the development of circulatory regulation and nerve activity in preterm infants are influenced by the extrauterine environment.

Bruxism defined and graded: an international consensus

To date, there is no consensus about the definition and diagnostic grading of bruxism. A written consensus discussion was held among an international group of bruxism experts as to formulate a definition of bruxism and to suggest a grading system for its operationalisation. The expert group defined bruxism as a repetitive jaw-muscle activity characterised by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible. Bruxism has two distinct circadian manifestations: it can occur during sleep (indicated as sleep bruxism) or during wakefulness (indicated as awake bruxism). For the operationalisation of this definition, the expert group proposes a diagnostic grading system of 'possible', 'probable' and 'definite' sleep or awake bruxism. The proposed definition and grading system are suggested for clinical and research purposes in all relevant dental and medical domains.

Influence of bilirubin photoisomers on unbound bilirubin measurement in clinical settings

Background

Measured unbound bilirubin concentration is influenced by bilirubin photoisomers. Bilirubin photoisomers are produced even with only a slight light exposure, and clinical samples are inevitably exposed to light. The objective of the study was to evaluate the influence of bilirubin photoisomers on the measurement of unbound bilirubin using serum of jaundiced neonates during blue light phototherapy.

Methods

Five neonates treated with phototherapy for hyperbilirubinaemia were enrolled. The samples were taken 12 h after initiation of phototherapy. Samples were processed by irradiation with blue light, by indoor ceiling light, by both blue light and indoor ceiling light or shaded. Bilirubin subfractions, total bilirubin and unbound bilirubin were measured.

Results

Compared with the non-irradiated samples, the (EZ)-cyclobilirubin concentration and (ZE)-bilirubin/(ZZ)-bilirubin ratio significantly increased in the blue light-irradiated samples, the (ZE)-bilirubin/(ZZ)-bilirubin ratio significantly increased in the indoor ceiling light-irradiated samples, and the (EZ)-cyclobilirubin, (EZ)-bilirubin and (ZE)-bilirubin/(ZZ)-bilirubin ratio significantly increased in the samples irradiated with both lights. No change was noted in unbound bilirubin in any group.

Conclusions

We consider that changes in bilirubin photoisomers induced by light exposure during clinical practice do not influence the measured unbound bilirubin concentration.

Functional lateralization of sensorimotor cortex in infants measured using multichannel near-infrared spectroscopy

Multichannel near-infrared spectroscopy (MNIRS) was used for the functional imaging of the sensorimotor cortex of newborn infants during passive knee and elbow movement under sedated sleep. Contralateral knee and elbow movement caused a marked increase in the concentration of oxyhemoglobin ([oxyHb]) from the baseline values at site within the sensorimotor area in all infants. During ipsilateral knee and elbow movement, [oxyHb] showed smaller changes, equivalent to 64 ± 23 and 66 ± 28% of the changes that occurred with contralateral stimulation, respectively. The mean times corresponding to maximal changes in [oxyHb] were 16.1 ± 3.3 s for contralateral knee movement and 17.9 ± 5.7 s for contralateral elbow movement. No significant difference was noted between the mean latencies showing the maximal changes in [oxyHb] between contralateral and ipsilateral movement. There was a significant difference in the area and degree of response between the contralateral and ipsilateral movement. MNIRS could be a useful tool to understand the pathophysiology of the developing brain and monitor cortical responses in various clinical situations.

Assessment of bruxism in the clinic

Bruxism is a much-discussed clinical issue in dentistry. Although bruxism is not a life-threatening disorder, it can influence the quality of human life, especially through dental problems, such as tooth wear, frequent fractures of dental restorations and pain in the oro-facial region. Therefore, various clinical methods have been devised to assess bruxism over the last 70 years. This paper reviews the assessment of bruxism, provides information on various assessment methods which are available in clinical situations and discusses their effectiveness and usefulness. Currently, there is no definitive method for assessing bruxism clinically that has reasonable diagnostic and technical validity, affects therapeutic decisions and is cost effective. One future direction is to refine questionnaire items and clinical examination because they are the easiest to apply in everyday practice. Another possible direction is to establish a method that can measure actual bruxism activity directly using a device that can be applied to patients routinely. More clinical studies should examine the clinical impact of bruxism on oral structures, treatment success and the factors influencing the decision-making process in dental treatment.

Relationship between cerebral oxygenation and phosphorylation potential during secondary energy failure in hypoxic-ischemic newborn piglets

The aim of this study was to evaluate the hypothesis that cerebral hemoglobin (Hb) oxygenation is related to phosphorylation potential during primary and secondary cerebral energy failure in newborn infants who have experienced birth asphyxia. We subjected newborn piglets to severe transient cerebral hypoxic-ischemia followed by resuscitation and examined cerebral energy metabolism by 31P-magnetic resonance spectroscopy and evaluated changes in cerebral Hb oxygen saturation (ScO2) using full-spectrum near-infrared spectroscopy before, during, and up to 54 h after the hypoxic-ischemic insult. ScO2 was significantly decreased during the hypoxic-ischemic insult compared with baseline values. During secondary energy failure, piglets were separated based on the relationship between the ratio of phosphocreatine to inorganic phosphate and ScO2; those with a negative correlation were less injured than those with a positive correlation. These results indicate that changes in ScO2 as measured by near-infrared spectroscopy are related to phosphorylation potential during secondary energy failure in asphyxiated infants.