Nobuaki Matsunaga

Efficacy of bacterial ribosomal RNA-targeted reverse transcription-quantitative PCR for detecting neonatal sepsis: a case control study

BackgroundNeonatal sepsis is difficult to diagnose and pathogens cannot be detected from blood cultures in many cases. Development of a rapid and accurate method for detecting pathogens is thus essential. The main purpose of this study was to identify etiological agents in clinically diagnosed neonatal sepsis using bacterial ribosomal RNA-targeted reverse transcription-quantitative PCR (BrRNA-RT-qPCR) and to conduct comparisons with the results of conventional blood culture. Since BrRNA-RT-qPCR targets bacterial ribosomal RNA, detection rates using this approach may exceed those using conventional PCR.MethodsSubjects comprised 36 patients with 39 episodes of suspected neonatal sepsis who underwent BrRNA-RT-qPCR and conventional blood culture to diagnose sepsis. Blood samples were collected aseptically for BrRNA-RT-qPCR and blood culture at the time of initial sepsis evaluation by arterial puncture. BrRNA-RT-qPCR and blood culture were undertaken using identical blood samples, and BrRNA-RT-qPCR was performed using 12 primer sets.ResultsPositive rate was significantly higher for BrRNA-RT-qPCR (15/39, 38.5%) than for blood culture (6/39, 15.4%; p = 0.0039). BrRNA-RT-qPCR was able to identify all pathogens detected by blood culture. Furthermore, this method detected pathogens from neonates with clinical sepsis in whom pathogens was not detected by culture methods.ConclusionsThis RT-PCR technique is useful for sensitive detection of pathogens causing neonatal sepsis, even in cases with negative results by blood culture.

Glucose metabolism soon after birth in very premature infants with small- and appropriate-for-gestational-age birth weights

UNLABELLED The intrauterine environment affects the development of insulin resistance in adulthood. To determine the influence of foetal growth restriction on glucose metabolism, we assessed indices of insulin sensitivity soon after birth in very premature infants. Blood samples were collected at birth from 52 premature infants with a gestational age of ≤31 weeks, who were divided into a group whose birth weight was small for their gestational age (SGA group, n=19) and a group whose birth weight was appropriate for their gestational age (AGA group, n=33). Blood glucose, serum insulin and C-peptide immunoreactivity (CPR) levels were measured in both groups. Furthermore, the quantitative insulin check index (QUICKI) was also calculated. Correlations between these indices and glucose metabolism and the standard deviation (SD) score for birth weight were also determined. The levels of insulin and CPR were significantly (p<0.05) lower in the SGA group than in the AGA group. The QUICKI was significantly (p<0.05) higher in the SGA group compared with the AGA group. The SD score for birth weight was correlated with the QUICKI (p<0.01), the serum insulin level (p<0.05) and the CPR level (p<0.05) in all 52 infants. CONCLUSION In very premature infants, poor foetal growth may impair foetal insulin secretion and affect the QUICKI at birth.

The clinical utility of a near patient care rapid microarray-based diagnostic test for influenza and respiratory syncytial virus infections in the pediatric setting.

We evaluated the potential clinical utility of an automated near patient molecular assay Verigene Respiratory Virus Plus (RV+) and rapid immunochromatographic antigen tests (RIAT) in the pediatric setting for diagnosis of influenza and respiratory syncytial virus infections when testing was performed by the pediatrician seeing the patient. Overall, with respect to influenza virus, sensitivity and specificity for RIAT were 70.8% and 100%, respectively, compared to 100% and 96.2%, respectively, for RV+. For respiratory syncytial virus, sensitivity and specificity for RIAT were 78.9% and 100%, respectively, compared to 100% and 100%, respectively, for RV+. When RIAT and RV+ sensitivity for influenza virus was compared based on the time the patient presented after onset of fever, the sensitivity of RIAT at 6 hours was 37.5% compared to 100% for RV+. At 12 hours, RIAT improved to 60.9%. This study confirms the clinical utility of RV+ in the pediatric setting.

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.

The treatment with infliximab for pediatric Crohn's disease: Nationwide survey of Japan.

Childhood‐onset inflammatory bowel disease (IBD) is characterized by extensive intestinal involvement and rapid early progression. Infliximab (IFX), cyclosporin (CYA), and tacrolimus (FK506) are increasingly used to treat pediatric IBD; however, their long‐term effects and adverse events have not been properly investigated in pediatric patients. The aim of this study was to characterize the effects of these biologics and immunomodulators on pediatric IBD patients in Japan. Additionally, we assessed IFX use in pediatric patients with Crohns disease (CD).

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.

Lipid profile and atherogenic indices soon after birth in Japanese preterm infants.

The intra‐uterine environment affects the risk of development of cardiovascular disease in adulthood. The aim of this study was to determine the influence of prematurity and foetal growth restriction on lipid metabolism, by assessing atherogenic indices soon after birth in preterm infants.

An Investigation into the Vancomycin Concentration in the Cerebrospinal Fluid Due to Vancomycin Intraventricular Administration in Newborns: A Study of 13 Cases

AbstractTreatment against shunt infection by transvenous antimicrobial treatment is difficult, with a high risk of relapse. Consequently, to maintain a sufficient cerebrospinal fluid (CSF) concentration, intraventricular administration is utilized in combination with the transvenous administration of vancomycin (VCM). Few studies have so far investigated the optimum administration dose for newborns and the concentration in the CSF. Therefore, we chronologically measured the VCM concentration in the CSF after VCM intraventricular administration in newborns and attempted to elucidate the optimum administration method.The participants consisted of newborns admitted to Juntendo University Neonatal intensive care unit from March 2007 to June 2011 who underwent interventricular shunting placement. VCM was intraventricularly administered to 10 patients for a total of 13 cases. The CSF concentration of VCM was chronologically measured at 12 to 120 hours following the intraventricular administration of VCM.The intraventricular administration groups with VCM of 20 (n = 6) and 10 mg (n = 2) had a high concentration in the CSF at 24 hours following administration (95–168 mg/L), with the concentration remaining high at 72 hours (13.2–72 mg/L). At the same time, in the 5 mg group (n = 5), the concentration in the CSF 24 hours following VCM administration was sufficiently maintained (33.2–62.9 mg/L), with a sufficient trough concentration still maintained at 72 hours (11.7–16.5 mg/L).The concentration in the CSF is prolonged in newborns, thus allowing a sufficient therapeutic range to be maintained even at an intraventricular administration of 5 mg. It is therefore believed that the monitoring of the CSF is very important regarding the administration interval because the VCM concentration in the CSF differs depending on the case.