Naho Ikeda

Evaluation of kidney dysfunction and angiotensinogen as an early novel biomarker of intrauterine growth restricted offspring rats

Background:Few studies have addressed the growing concerns of chronic kidney diseases in children with intrauterine growth restriction (IUGR). Therefore, the purpose of this study was to evaluate long-term kidney dysfunction and determine if urinary angiotensinogen (AGT) was suitable as a novel early biomarker for kidney dysfunction in IUGR offspring.Methods:Pregnant rats underwent bilateral uterine artery ligation, and as a control group, sham surgeries were performed.Results:The birth weight was reduced, the urinary AGT to creatinine ratio was significantly higher at week 20, and urinary protein levels were significantly higher at week 32 in IUGR rats than in control rats. On the other hand, the histological findings at week 32 revealed long-term kidney dysfunction, more severe glomerulosclerosis, and greater glomerular diameters in IUGR rats. Moreover, AGT mRNA expression and immunohistological staining were significantly increased in IUGR rats; this suggests that the intrarenal renin–angiotensin system (RAS) contributes to renal dysfunction of IUGR offspring.Conclusion:Urinary AGT elevation prior to urinary protein levels suggests that AGT is an early biomarker. At week 32, kidney dysfunction was severe in IUGR rats and intrarenal RAS appeared to be one of the causes.

Effects of breastfeeding on the risk factors for metabolic syndrome in preterm infants.

Evidence suggests that breastfeeding during infancy lowers the risk of metabolic syndrome (MS) and its attendant risk factors in adult life. To investigate the influence of feeding type on the risk factors of MS, we assessed insulin sensitivity and lipid and apolipoprotein metabolism in preterm infants. Blood samples were collected from preterm infants at the time of discharge. Infants were separated into two groups: a breast milk (BM) group receiving ⩾90% of their intake from BM, and a mixed-fed (MF) group receiving ⩾50% of their intake from formula. The following indices were then compared between the two groups. Blood glucose and serum insulin levels were used to calculate the quantitative insulin sensitivity check index (QUICKI). We also measured serum total cholesterol (TC), low-density lipoprotein cholesterol (LDLc), high-density lipoprotein cholesterol (HDLc), apolipoprotein-A1 (apoA1) and apolipoprotein-B (apoB) levels, and the ratios of TC/HDLc, LDLc/HDLc and apoB/apoA1. The mean gestational age was 32.9 weeks at birth, and blood samples were collected at a mean corrected age of 37.4 weeks. There were 22 infants in the BM group and 19 in the MF group. QUICKI was significantly higher in the BM group. TC, HDLc and apoA1 were not significantly different between the groups, but LDLc and apoB levels were significantly higher in the BM group. The TC/HDLc, LDLc/HDLc and apoB/apoA1 ratios were significantly higher in the BM group. In preterm infants, the type of feeding exposure in the early postnatal period may influence glucose, lipid and apolipoprotein metabolism, and affect markers of MS.

Oxidative stress early in infancy and neurodevelopmental outcome in very low‐birthweight infants

Reactive oxygen species may be involved in serious diseases in premature infants. The objective of this study was to assess the relationship between neurodevelopmental outcome and oxidative stress marker level in the urine of very low‐birthweight (VLBW) infants.

Effect of insulin‐like growth factor‐I during the early postnatal period in intrauterine growth‐restricted rats

Insulin‐like growth factor‐I (IGF‐I) is essential for perinatal growth and development; low serum IGF‐I has been observed during intrauterine growth restriction (IUGR). We investigated the effects of recombinant human (rh) IGF‐I in IUGR rats during the early postnatal period.

Influence of gestational age on serum incretin levels in preterm infants

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are the incretin hormones secreted from the intestine in response to enteral feeding to stimulate insulin secretion. We investigated the relationship serum GIP and GLP-1 levels with gestational age, and insulin secretion in preterm infants. Serum GIP and GLP-1 levels were measured at birth and at 1, 2 and 4 weeks after birth in 30 infants, including 12 born before 30th week of gestation (early group) and 18 born after 30th week of gestation (late group). Blood glucose and serum insulin levels were measured, and the quantitative insulin sensitivity check index (QUICKI) was also calculated. The levels of GLP-1 at 2 and 4 weeks were significantly higher in the early group than those in the late group. The levels of GIP were not significantly different between two groups. At 4 weeks, serum insulin level was significantly higher and QUICKI was significantly lower in the early group. Furthermore, GLP-1 levels were significantly correlated with QUICKI and the serum insulin levels in all infants at 4 weeks. In preterm infants, enteral feeding to premature intestine may be associated with GLP-1 secretion. GLP-1 is also related to stimulated insulin secretion in early postnatal period.

Measurement of cytokine levels in cerebrospinal fluid over time in neonatal Enterococcal meningitis

Enterococcus faecalis is rarely involved in neonatal meningitis. Several studies have indicated that the cytokines related to bacterial infection may induce nerve cell damage; therefore, the cytokine levels in cerebrospinal fluid (CSF) could represent a valuable hallmark for rapid recognition of the disease and evaluation of the degree of neurological involvement. We analyzed cytokine levels in the CSF of a neonate with E. faecalis meningitis over time. Tumor necrosis factor‐α (TNF‐α) tended to be elevated during the acute phase of infection, and then decreased during the convalescent stage after treatment. CSF inflammatory cytokine measurement may provide important clues for predicting the development of complications in the host because some of these cytokines, such as TNF‐α, can injure neurons.

Association of zinc and copper with clinical parameters in the preterm newborn

Given that preterm infants are born at a time of rapid fetal growth, they are at risk of deficiency of essential nutrients for brain development, including zinc (Zn) and copper (Cu). This study evaluate the relationship between serum Cu or Zn, gestational age (GA) and anthropometric parameters at birth in preterm infants.

A pilot study of the effect of human breast milk on urinary metabolome analysis in infants.

Abstract Background: This study aimed to examine the nutritional effect of breast feeding on healthy term infants by using urinary metabolome analysis. Methods: Urine samples were collected from 19 and 14 infants at 1 and 6 months, respectively. Infants were separated into two groups: the breast-fed group receiving <540 mL/week of their intake from formula (n=13 at 1 month; n=9 at 6 months); and the formula-fed group receiving no breast milk (BM) (n=6 at 1 month; n=5 at 6 months). Urinary metabolome analysis was performed using capillary electrophoresis-time-of-flight mass spectrometry (CE-TOF/MS). Results: A total of 29 metabolites were detected by CE-TOF/MS metabolome analysis in all samples. Urinary excretion of choline metabolites (choline base solution, N,N-dimethylglycine, sarcosine, and betaine) at 1 month were significantly (p<0.05) higher in breast-fed infants than in formula-fed infants. However, choline metabolites were not significantly different between the groups at 6 months. Urinary excretion of lactic acid in breast-fed infants at 1 and 6 months was significantly lower than that in formula-fed infants. Urinary l(−)-threonine and l-carnosine excretion at 1 month was significantly lower in breast-fed infants than in formula-fed infants, but it was not significantly different between the groups at 6 months. Conclusions: The type of feeding in early infancy affects choline metabolism, as well as lactate, threonine, and carnosine levels, in healthy term infants. Urinary metabolome analysis by the CE-TOF/MS method is useful for assessing nutritional metabolism in infants.

Fat emulsion given to very low-birthweight infants increases urinary l-FABP

In premature infants, many factors influence the function of renal tubules, such as asphyxia, respiratory disorders, use of high‐concentration oxygen, hypotension, and drug treatment. When tubular ischemia and oxidative stress develop due to renal microcirculatory pathology, urinary l‐type fatty acid‐binding protein (l‐FABP) level increases.

Influence of i.v. lipid emulsion on lipoprotein subclass in preterm infants

Lipid emulsions given i.v. are normally rapidly metabolized by apoprotein recruited from high‐density lipoprotein (HDL) particles in the blood. Very low‐birthweight infants (VLBWI), however, have a low rate of lipid clearance from the blood, and therefore lipid emulsions must be given carefully to minimize the risk of hyperlipidemia. The purpose of this study was to evaluate the influence of i.v. lipid emulsion on lipoprotein subclass profile in VLBWI during the early postnatal period.