Classification of pseudohypoaldosteronism type II as type IV renal tubular acidosis: results of a literature review.

Pseudohypoaldosteronism (PHA) type II (PHA2) is a genetic disorder that leads to volume overload and hyperkalemic metabolic acidosis. PHA2 and PHA type I (PHA1) have been considered to be genetic and pediatric counterparts to type IV renal tubular acidosis (RTA). Type IV RTA is frequently found in adults with chronic kidney disease and is characterized by hyperchloremic hyperkalemic acidosis with normal anion gap (AG). However, we recently observed that PHA1 was not always identical to type IV RTA. In this study, we focused on the acid-base balance in PHA2. Through a literature search published between 2008-2020, 46 molecularly diagnosed cases with PHA2 were identified (median age of 14 years). They comprised 11 sets of familial and 16 sporadic cases and the pathology was associated with mutations in WNK 4 (n = 1), KLHL3 (n = 17), and CUL3 (n = 9). The mean potassium (K+) level was 6.2 ± 0.9 mEq/L (n = 46, range 4.0-8.6 mEq/L), whereas that of chloride (Cl-) was 110 ± 3.5 mEq/L (n = 41, 100-119 mEq/L), with 28 of 41 cases identified as hyperchloremic. More than half of the cases (18/35) presented with metabolic acidosis. Although AG data was obtained only in 16 cases, all but one cases were within normal AG range. Both Cl- and HCO3- levels showed significant correlations with K+ levels, which suggested that the degree of hyperchloremia and acidosis reflect the clinical severity, and is closely related to the fundamental pathophysiology of PHA2. In conclusion, our study confirmed that PHA2 is compatible with type IV RTA based on laboratory findings.

Microbiota in human breast milk: Noninfectious mastitis versus without mastitis.

BACKGROUND: Long-term breastfeeding is beneficial for both mothers and infants and mastitis is associated with the premature interruption of breastfeeding. Mastitis can be infectious or noninfectious. However, the effect of noninfectious mastitis on milk microbiota is not well-understood. In this study, we aimed to clarify the relationship between noninfectious mastitis and the microbiota by conducting breast milk culture tests. METHODS: We compared the milk microbiota between women with noninfectious mastitis and without mastitis. Bacterial cultures were compared in 143 milk samples from January to November 2022, and bacterial diversity was evaluated based on the total number of bacterial species and bacterial species found per specimen. RESULTS: Women with noninfectious mastitis provided samples at a significantly later stage postpartum (p < 0.01). The total bacterial count was significantly lower in samples from participants with noninfectious mastitis (p < 0.01). The bacterial diversity of milk from participants with noninfectious mastitis was lower than that without mastitis: nine bacterial species identified in the former and 21 in the latter. The number of Rothia spp. was significantly higher, whereas the number of Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas fluorescens was significantly lower in samples from women with mastitis. There was no correlation between postpartum week and the number of bacterial species or presence of Rothia spp. CONCLUSIONS: Noninfectious mastitis is associated with a decrease in the diversity of human milk microbiota, indicating impaired immune, metabolic, and neuroendocrine development functions in infants. Rothia spp. may also be associated with noninfectious mastitis, suggesting a possible target for future research.

Mortality and morbidity of extremely low birth weight infants in Japan, 2015.

BACKGROUND: In Japan, the mortality rate of extremely low birth weight (ELBW) infants is notably low in comparison with other developed countries, but the prevalence of chronic lung disease (CLD) and retinopathy of prematurity (ROP) is relatively high. This study aimed to estimate the mortality and morbidity of ELBW infants born in 2015 who were admitted to neonatal intensive care units (NICUs) in Japan and to examine the factors that affected the short-term outcomes of these infants. We also compared the mortality of ELBW infants born in 2005, 2010, and 2015. METHODS: We analyzed the mortality, morbidity, and factors related to short-term outcomes of ELBW infants, using data from 2782 infants born in 2015 and registered at NICUs in Japan. RESULTS: The mortality rates during NICU stays were 17.0%, 12.0%, and 9.8% for ELBW infants born in 2005, 2010, and 2015, respectively. Among ELBW infants born in 2015, multiple logistic regression analysis showed that short gestational age and low birthweight Z-score contributed to the increased risk of death. Births by cesarean section and antenatal corticosteroid administration were significantly associated with a reduced risk of death. Among infants who survived, CLD was observed in 53.1% and ROP requiring treatment was observed in 30.4%. CONCLUSIONS: Mortality in ELBW infants decreased significantly from 2005 to 2015. As CLD and ROP may affect quality of life and long-term outcomes of infants who survived, prevention strategies and management for these complications are critical issues in neonatal care in Japan.

Questionnaire survey on donor human milk programs targeting NICUs in Japan.

BACKGROUND: Since 2019, neonatal intensive care units (NICUs) with access to human milk banks (HMBs) have increased in Japan. In this study, using a questionnaire survey, we explored an understanding of the purpose, status, and problems of donor human milk (DHM) use and the status of enteral nutrition (EN) in very-low-birthweight infants (VLBWIs) in NICUs with access to HMBs. METHODS: A questionnaire was sent to 47 NICUs that had access to HMBs. Participants were surveyed from the begining of January to the end of February 2022. RESULTS: In total, 37 of 47 (78.9%) NICUs responded to the questionnaire. The most common indications for DHM were gestational age of less than 28 weeks (78.3%) and birthweight of less than 1500 g (100%). Informed consent was obtained from the physicians and most parents accepted DHM. All NICUs responded that EN for VLBWIs should start ideally within 24 h of birth, but in reality, nine NICUs (25%) and 18 NICUs (50%) began EN within 12 and 24 h of birth, respectively. Additionally, seven of the nine NICUs that started EN within 12 h after birth routinely used DHM for VLBWIs. For infants with birthweights of 1000-1499 g, it was not uncommon to start EN within 24 h of birth with formula milk. CONCLUSION: All NICUs responded that the indication for DHM was very-low birthweight and that such infants would receive health benefits from DHM. In Japan, there is a trend of starting EN early in VLBWIs. Accessibility to HMB may be important for starting EN within 24 h of birth.

Medical care of newborns born to mothers with confirmed or suspected severe acute respiratory syndrome coronavirus 2 infections in Japan.

BACKGROUND: There are currently no definitive guidelines regarding newborns born to mothers with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to investigate the medical care and management that provided or would provide for such newborns. METHODS: A web survey was conducted between September and October 2020. A total of 624 hospitals, which generally accept pregnant women for delivery, were involved in this study. The survey included the number of newborns born to mothers with confirmed SARS-CoV-2 infection and evaluated policies regarding the medical care and management of newborns born to mothers with confirmed or suspected SARS-CoV-2 infection. RESULTS: Pregnant women with confirmed or suspected SARS-CoV-2 infection were accepted or planned to be accepted in 54% (334) of the hospitals. Out of 52 newborns born to mothers with confirmed SARS-CoV-2 infection, SARS-CoV-2 RNA was detected from the nasopharyngeal swab of one newborn shortly after birth. The types of personal protective equipment during the delivery, the separation of the newborns from the mothers, the SARS-CoV-2 testing methods, and the use of incubators during the quarantine period were uniformly provided. However, the methods of ventilator treatment in the event of respiratory disorders, feeding during maternal isolation, and de-quarantine and discharge criteria varied. CONCLUSIONS: This survey demonstrated that one newborn detected a SARS-CoV-2 RNA shortly after birth out of 52 newborns who were born to mothers with confirmed SARS-CoV-2 infection. The policies regarding medical care and management for these newborns in Japan were provided.

Experience using donor human milk: A single-center cohort study in Japan.

BACKGROUND: Donor human milk (DHM) became available in Japan when the first human milk bank was established in 2017. This study investigated the effects of DHM on enteral nutrition (EN) in very low birth weight (VLBW) infants in the single center in Japan. METHODS: Seventy-six VLBW infants hospitalized between April 2017 and March 2020 at Showa University Hospital were included in the study. We retrospectively evaluated age (hours) at which EN was initiated and age (days) until complete feeding (EN > 100 mL/kg/day) was achieved. We compared the DHM and non-DHM groups, or the early human milk (EHM) and non-EHM groups. The EHM group was defined as those in which EN was initiated with the mother's own milk or DHM within 12 h of birth. RESULTS: In 30 extremely low birth weight (ELBW) infants, EN was initiated at significantly earlier postnatal hours in the DHM group compared to those in the non-DHM group. Complete feeding was achieved at significantly earlier ages in the EHM group after adjusting for gastrointestinal complications and gestational age. Additionally, the changes in body weight z-scores from birth to term-equivalent age were significantly greater in the EHM group after adjusting for exclusive breastfeeding and small for gestational age, compared to the non-EHM group. Statistical significance was not noted in 46 subjects (birth weight, 1000-1500 g). CONCLUSION: The use of DHM may contribute to earlier initiation and achievement of EN, resulting in greater early postnatal growth in ELBW infants in Japan.

Birth Weight Standard Deviation Score is a Significant Determinant of Serum Urotensin-II Levels at Term-Equivalent Age in Preterm Infants.

OBJECTIVE: Urotensin II (U-II) is a potent vasoconstrictor peptide, and increased U-II levels are associated with atherosclerosis and hypertension in adults. Low birth weight (LBW) infants have higher risks of such diseases in the future. A small number of nephrons is one of possible mechanism underlying these risks in LBW infants, while vascular elasticity and cardiac function might be another important factor. The objective of this study is to evaluate U-II levels in preterm LBW infants at an early stage of life and determine perinatal factors associated with U-II levels. STUDY DESIGN: The study population consisted of 57 preterm LBW infants (26 males and 31 females), including 49 appropriate for gestational age (AGA) and 8 small for gestational age (SGA) infants, born at a gestational age of ≤34 weeks with a mean birth weight of 1,589 g. Serum U-II levels were measured at term-equivalent age to evaluate perinatal factors related to serum U-II levels. RESULTS: Preterm SGA infants had significantly higher serum U-II levels than preterm AGA infants at term-equivalent age (p = 0.019). Serum U-II levels in preterm LBW infants at term-equivalent age were inversely correlated with birth weight standard deviation (SD) score in a simple regression analysis (r = - 0.395, p = 0,002) and the correlation was maintained in the multiple regression analysis. CONCLUSION: Our results indicate that birth weight SD score might be associated with serum U-II levels in preterm LBW infants at term-equivalent age. Further studies are required to determine whether U-II levels at an early stage of life might influence the risk of atherosclerosis and hypertension. KEY POINTS: · U-II is a potent vasoconstrictor.. · We evaluated serum U-II levels in preterm infants.. · Fetal growth is negatively related to serum U-II levels..

Distribution of serum adiponectin isoforms in pediatric patients with steroid-sensitive nephrotic syndrome.

BACKGROUND: Serum adiponectin circulates in three multimeric isoforms: high-molecular-weight (HMW), middle-molecular-weight (MMW), and low-molecular-weight (LMW) isoforms. Potential change in the circulating adiponectin levels in patients with nephrotic syndrome (NS) remain unknown. This study aimed to assess the levels of total adiponectin and the distribution of its isoforms in pediatric patients with NS. METHODS: We sequentially measured total adiponectin and each adiponectin isoform levels at the onset of NS, initial remission, and during the remission period of the disease in 31 NS patients. We also calculated the ratios of HMW (%HMW), MMW (%MMW), and LMW (%LMW) to total adiponectin incuding 51 control subjects. RESULTS: The median of total serum adiponectin levels in patients were 36.7, 36.7, and 20.2 µg/mL at the onset, at initial remission, and during the remission period of NS, respectively. These values were significantly higher than those in control subjects. The median values of %HMW, %MMW, and %LMW values were 56.9/27.0/14.1 at the onset, 62.0/21.8/13.4 at the initial remission, and 58.1/21.7/17.5 at during the remission period of NS, respectively. Compared with control subjects, %HMW at initial remission and %MMW at the onset were high, and the %LMW values at the onset and at initial remission were low. CONCLUSIONS: In patients with NS, total serum adiponectin levels increase at the onset of the disease, and the ratio of adiponectin isoforms changes during the course of the disease. Further studies are needed to delineate the mechanisms between proteinuria and adiponectin isoforms change.

Survey of a nutrition management method for very low birthweight infants: Status before wide use of breast milk banks in Japan.

BACKGROUND: The importance of breast-feeding for very low birthweight (VLBW) infants has been pointed out. Some overseas studies suggested that the standardization of enteral nutrition (EN) leads to improved prognosis in VLBW infants. In Japan, however, physicians in charge of infants are responsible for making nutrition management decisions on an individual basis. We conducted an online survey to clarify the course of nutrition management of VLBW infants currently implemented in Japan. METHODS: We mailed a notice to 300 representative neonatologists throughout Japan requesting their participation in the online survey. On the survey website, neonatologists responded to questions regarding the nutritional strategy for five birthweight groups (less than 500 g, 500-749 g, 750-999 g, 1,000-1,249 g and 1,250-1,499 g). RESULTS: Responses were recieved from 137 neonatologists. The first choice for EN up to 1 week after birth was breast milk regardless of birthweight (92.0% for 1,250-1,499 g to 95.6% for 500-999 g). More than 30% of the respondents answered that they fast infants who weigh <750 g at birth or feed them with other mothers' breast milk until their own mother's milk becomes available. The lower the birthweight, the later EN is started, and the greater the number of days to establish EN. CONCLUSION: The lower the birthweight, the more difficult it is to feed infants their own mother's milk and the later the EN is started. If donor milk is supplied in a stable manner, it takes fewer days to establish EN.

Policy statement of enteral nutrition for preterm and very low birthweight infants.

For preterm and very low birthweight infants, the mother's own milk is the best nutrition. Based on the latest information for mothers who give birth to preterm and very low birthweight infants, medical staff should encourage and assist mothers to pump or express and provide their own milk whenever possible. If the supply of maternal milk is insufficient even though they receive adequate support, or the mother's own milk cannot be given to her infant for any reason, donor human milk should be used. Donors who donate their breast milk need to meet the Guideline of the Japan Human Milk Bank Association. Donor human milk should be provided according to the medical needs of preterm and very low birthweight infants, regardless of their family's financial status. In the future, it will be necessary to create a system to supply an exclusive human milk-based diet (EHMD), consisting of human milk with the addition of a human milk-derived human milk fortifier, to preterm and very low birthweight infants.

Microwave treatment of breast milk for prevention of cytomegalovirus infection.

BACKGROUND: Breast milk (BM) is the best nutrition for very preterm infants (VPI), except when provided by human cytomegalovirus (HCMV)-seropositive mothers. Given that VPI are at high risk of developing a sepsis-like syndrome or cholestasis, methods for prevention of HCMV infection via BM have been investigated. Although Holder pasteurization (HP) is the gold standard, HP needs special instruments. Microwave (MW) is available anywhere, therefore, we performed this study to determine whether MW can be used for HCMV prevention. METHODS: Human cytomegalovirus Towne strain was added to formula, followed by heating procedure using HP or MW (at 500 W for 20, 30, 40, or 60 s). HFL-III cells were seeded in culture dishes. Aliquots of HCMV-milk samples after heating were inoculated onto susceptible cell monolayers. The number of plaques was counted to determine the viral titer. The determination of HCMV-DNA copies was also performed. RESULTS: Addition of HCMV for a viral load of 5.0 × 103 plaque-forming units (p.f.u.)/mL achieved 772 p.f.u./mL at baseline, with a decrease to 257 p.f.u./mL after MW radiation for 20 s. No plaque was detected after HP or MW for 30, 40, and 60 s. The temperature of the breast milk reached 60°C after MW radiation for 40 s. The number of HCMV-DNA copies did not change with MW. CONCLUSIONS: Microwave at 500 W for 40 s can be used as a prevention strategy for HCMV transmission. Further research including the loss of bioactive properties in BM is required prior to clinical application.

Germline gain-of-function mutations in RAF1 cause Noonan syndrome.

Noonan syndrome is characterized by short stature, facial dysmorphia and a wide spectrum of congenital heart defects. Mutations of PTPN11, KRAS and SOS1 in the RAS-MAPK pathway cause approximately 60% of cases of Noonan syndrome. However, the gene(s) responsible for the remainder are unknown. We have identified five different mutations in RAF1 in ten individuals with Noonan syndrome; those with any of four mutations causing changes in the CR2 domain of RAF1 had hypertrophic cardiomyopathy (HCM), whereas affected individuals with mutations leading to changes in the CR3 domain did not. Cells transfected with constructs containing Noonan syndrome-associated RAF1 mutations showed increased in vitro kinase and ERK activation, and zebrafish embryos with morpholino knockdown of raf1 demonstrated the need for raf1 for the development of normal myocardial structure and function. Thus, our findings implicate RAF1 gain-of-function mutations as a causative agent of a human developmental disorder, representing a new genetic mechanism for the activation of the MAPK pathway.

Necessity of human milk banking in Japan: Questionnaire survey of neonatologists.

BACKGROUND: If their own mother's milk (OMM) is not available, another mother's milk may be used for extremely low-birthweight (ELBW) infants. Human milk is a bodily fluid, however, therefore we have assumed that other mother's milk is currently seldom given to infants despite its superiority to formula. Although the World Health Organization and the American Academy of Pediatrics have recommended using donor human milk (DHM) from a human milk bank (HMB) in the case that OMM is not available, there is no HMB in Japan. To assess whether other mother's milk is used for ELBW infants and whether an HMB is necessary in Japan, we surveyed neonatal intensive care units (NICU) via questionnaire. METHODS: The questionnaire was sent by email to members of the Japanese Neonatologist Association who are responsible for NICU. RESULTS: In total, 126 completed questionnaires (70.7%) were returned and analyzed. One-fourth of NICU give other mother's milk to ELBW infants. The first choice of nutrition is OMM, but other mother's milk or formula is given to infants at 19% of NICU if OMM is unavailable. Approximately three-fourths of NICU would like an HMB. CONCLUSION: Although human milk contains contagious agents and authorities do not recommend giving other mother's milk as a substitute for OMM, other mother's milk is still a choice in NICU in Japan. Many neonatologists, however, would prefer a safer alternative, that is, DHM obtained from an accredited HMB. A well-regulated HMB should be established and safe DHM should be available for all preterm infants if necessary.

Is fat content of human milk decreased by infusion?

BACKGROUND: Human milk (HM) is the optimum nutrition for preterm infants. Previous studies showed that tube infusion decreased the fat content in thawed HM. The aim of this study was to determine if freezing­thawing is the main reason for decrease of fat content. In neonatal intensive care units, thawed HM is used in general, therefore the aim of this study was to investigate fat loss during tube infusion with regard to changes in tube size, material, and infusion rate. METHODS: First, pre-infusion and post-infusion fat content was measured in 15 fresh HM, 10 thawed HM and 6 formula samples. We compared post-infusion and pre-infusion fat content as well as the percent decrease in fat concentration among fresh HM, thawed HM and formula samples. Second, we measured the fat content of 160 thawed HM samples infused via four different diameters (3­6 Fr), two types of material (DEHP-free and PVC-free), and two infusion rates (30 or 60 min). We compared the percent decrease in fat concentration among four different tube sizes, between DEHP-free and PVC-free tubes, and between 30 and 60 min infusion durations. RESULTS: Post-infusion fat content was significantly decreased compared to before infusion in thawed HM and fresh HM but not in formula. Given that thawed HM resulted in larger decrease in fat content, we performed a second experiment and found no difference regarding differing size, materials or infusion rate. CONCLUSIONS: There was a far greater decrease in the post-infusion fat content of thawed HM compared to fresh HM under all test conditions.

Abdominal aortic intima-media thickness in preschool children born preterm.

Recently aortic intima-media thickness (IMT) has been used as an earlier marker of preclinical atherosclerosis in high-risk children, such as those with type 1 diabetes mellitus and hypercholesterolemia. Children who were born preterm have an early elevation in insulin resistance, which may be a risk factor for metabolic syndrome in adulthood. However, there is no optimal marker of subsequent cardiovascular disease for children born preterm. In this study, we aimed to evaluate the effect of preterm birth on aortic IMT during the preschool period. Mean aortic IMT was measured by ultrasound in 26 subjects born preterm (gestational age <37 weeks [preterm group]) and 11 control subjects born at term (term group). The mean aortic IMT of the preterm group was significantly thicker than that of the term group (preterm group: median 577 µm, interquartile range (524-599) versus term group: 517 µm (442-544); p = 0.003). Mean aortic IMT may be one of the earlier markers of subclinical vasculopathy in preschool children who were born preterm.

Evaluating milk flow patterns using the high flow rate period during breast pumping.

PROBLEM: Breast pumping practices have scope for improvement. BACKGROUND: Breast milk weight measurement can be used to evaluate milk flow pattern dynamics during breast pumping. AIM: To determine inter-individual differences in milk flow patterns and their practical implications based on high milk flow rate period (HFP) data among Japanese women expressing breast milk using an electric pump. METHODS: This cross-sectional, observational study analysed data from 19 women (33.0 ± 3.9 years) nursing 1-6-month-old infants and with previous breast milk expression experience. Breast milk was weighed continuously during a 15-min single-breast electric pumping session. The HFP features and flow rate time (≥0.1 g/s) were analysed to determine each individual's milk flow pattern. FINDINGS: The total expressed breast milk was 69.8 ± 42.5 g with a maximum individual flow rate of 0.5 ± 0.2 g/s. The breast milk yielded during the HFPs was 43.1 (34.4-81.3) g, accounting for 82.5 % (69.9-89.5 %) of the total expressed breast milk. HFP occurred 0-3 times during the 15-min session. Multiple discrete and continuous milk flow patterns were observed. Among those with discrete HFP, the HFP interval was 221 (68-371) s. Breast milk fat content changes and subjective residual milk measurements implied sufficient milk removal. A strong positive correlation was noted between HFP length and total breast milk expression volume. DISCUSSION: Individual differences in milk flow patterns were observed among the women using HFP. Milk flow patterns were consistent with previous reports. CONCLUSION: Milk flow pattern data can be used to guide individualised lactation support.