Motoki Bonno

Cerebral oxygenation responses during kangaroo care in low birth weight infants.

BackgroundKangaroo care (KC) has been widely using to improve the care of low birth weight infants. However, very little is known about cerebral hemodynamics responses in low birth weight infants during KC intervention. The objective of this study was to elucidate the response of cerebral hemodynamics during KC in low birth weight infants.MethodsNear infrared spectroscopy measured regional cerebral oxygenation (rSO2), heart rate (HR), respiration rate (RR) measured by electrocardiogram, and percentages of oxygen saturation (SpO2) measured by pulse oxymetry was monitored in 16 preterm infants (< 1600 g) in three sessions: before, during, and after KC. Using power spectral analysis, total power (TP), low-frequency (LF, 0.02–0.20 Hz) and high-frequency (HF, 0.20–0.50 Hz) bands, the ratio of LF/HF were calculated and normalized as %LF or %HF = LF or HF/TP × 100 (%).ResultsSignificant differences were not observed in the mean rSO2, HR, and SpO2 throughout sessions; however, the TP of these parameters was significantly decreased during KC and increased after KC (p < 0.001). The %LF of LrSO2 and RrSO2 was decreased during KC (p < 0.05) with decreased %HF in RrSO2 (p < 0.05). The %LF of HR was significantly increased during KC while %HF was decreased (p < 0.05). Mean and TP of RR was increased during KC (p < 0.01 respectively) with the increase of quiet sleep state (p < 0.05) and decreased after KC (p < 0.01). The %LF of RR was increased after KC (p < 0.05) with decreased %HF (p < 0.05); however, significant changes were not observed during KC.ConclusionKC intervention appears to have influence on cerebral hemodynamics as well as cardiorespiratory parameters. The results of rSO2 and HR might be associated with quiet sleep states. The results of this study may indicate the contribution of KC intervention to the activation of central nervous system and brain function. Further study is needed to determine the underlying physiology responsible for these differences.

Mite-specific induction of interleukin-2 receptor on T lymphocytes from children with mite-sensitive asthma: Modified immune response with immunotherapy

BACKGROUND The efficacy of immunotherapy is still controversial. To elucidate the mechanisms of immunotherapy, we studied mite-specific induction of IL-2 receptor (IL-2R) expression on T lymphocytes from children with mite-sensitive asthma. METHODS Peripheral blood mononuclear cells were obtained from 28 children with mite-sensitive asthma: 13 had never received house dust immunotherapy (nonimmunotherapy group), 15 had been receiving house dust immunotherapy at the time of the study (immunotherapy group). After a 6-day culture with or without Dermatophagoides farinae (Df) antigen, the expression of IL-2Rp55 (CD25) and p75 on CD4+ or CD8+ T lymphocytes was measured by flow cytometry. RESULTS The nonimmunotherapy group showed significant Df-specific CD25 induction on CD4+ T lymphocytes (delta CD4+ CD25+) but little induction on CD8+ T lymphocytes (delta CD8+ CD25+). delta CD4+ CD25+ was correlated with the severity of the disease. In the immunotherapy group delta CD8+ CD25+ was significantly higher than in the nonimmunotherapy group or in normal subjects and correlated with Df-specific IgG4 and cumulative doses of house dust extract, whereas delta CD4+ CD25+ was similar in the nonimmunotherapy and the immunotherapy groups. IL-2Rp75 was not induced either on CD4+ or CD8+ T lymphocytes. CONCLUSIONS Our data suggest that house dust immunotherapy may have induced Df-specific CD8+ T lymphocytes in patients with mite-sensitive asthma and that the efficacy of immunotherapy may be attributed to the generation of Df-specific CD8+ T lymphocytes.

Acute myositis with transient decrease of albumin, immunoglobulin, and complement following rotavirus gastroenteritis

A 2‐year‐old boy developed acute myositis associated with rotavirus gastroenteritis. He had remarkable swelling and subcutaneous edema, mostly in the legs, 4 days after the onset of gastroenteritis. Marked elevation of creatine kinase was observed while serum albumin, immunoglobulin, and complement were decreased.

Thrombopoietin level is inversely related to blast count, not platelet number, in Down syndrome neonates with transient myeloproliferative disorder

Transient myeloproliferative disorder (TMD) in neonates with Down syndrome is characterized by increased megakaryoblastic cells in the peripheral blood. Despite their spontaneous regression in weeks, prognosis is not always favorable because of fatal hepatic fibrosis. In this study, blood thrombopoietin (TPO) levels were measured by ELISA in six TMD patients and the expression of c‐Mpl, a ligand for TPO, was examined on the blast cells from four patients by flow cytometer. At the onset, TPO level was undetectable in one patient and significantly lower in five patients than six neonatal controls (mean 0.52 fmol/ml, range 0.30–0.93 vs. 3.70, 1.38–8.33, P < 0.001), although platelet counts were similar (mean 321 × 109/l, range 42–1,040 vs. 253 × 109/l, 124–381). Two patients died of hepatic failure. TPO levels were measured in five patients after regression of the blast cells. With regression of blast cells, TPO levels were remarkably increased in four survived patients. In one patient with hepatic failure, TPO level was poorly elevated and relatively lower compared to the others. TPO levels were inversely correlated with blast numbers (r = −0.85, P < 0.001), but not with platelet counts (r = 0.426). Blast cells from four patients were all positive for c‐Mpl. Our findings suggest that megakaryocyte mass is a major regulator of TPO levels and hepatic failure may affect the TPO level because liver is a major source of TPO production. Am. J. Hematol. 58:267–272, 1998.

Emergence of physiological rhythmicity in term and preterm neonates in a neonatal intensive care unit

Background Biological rhythmicity, particularly circadian rhythmicity, is considered to be a key mechanism in the maintenance of physiological function. Very little is known, however, about biological rhythmicity pattern in preterm and term neonates in neonatal intensive care units (NICU). In this study, we investigated whether term and preterm neonates admitted to NICU exhibit biological rhythmicity during the neonatal period. Methods Twenty-four-hour continuous recording of four physiological variables (heart rate: HR recorded by electrocardiogram; pulse rate: PR recorded by pulse oxymetry; respiratory rate: RR; and oxygen saturation of pulse oxymetry: SpO2) was conducted on 187 neonates in NICU during 0–21 days of postnatal age (PNA). Rhythmicity was analyzed by spectral analysis (SPSS procedure Spectra). The Fisher test was performed to test the statistical significance of the cycles. The cycle with the largest peak of the periodogram intensities was determined as dominant cycle and confirmed by Fourier analysis. The amplitudes and amplitude indexes for each dominant cycle were calculated. Results Circadian cycles were observed among 23.8% neonates in HR, 20% in PR, 27.8% in RR and 16% in SpO2 in 0–3 days of PNA. Percentages of circadian cycles were the highest (40%) at <28 wks of gestational age (GA), decreasing with GA, and the lowest (14.3%) at >= 37 wks GA within 3 days of PNA in PR and were decreased in the later PNA. An increase of the amplitude with GA was observed in PR, and significant group differences were present in all periods. Amplitudes and amplitude indexes were positively correlated with postconceptional age (PCA) in PR (p < 0.001). Among clinical parameters, oxygen administration showed significant association (p < 0.05) with circadian rhythms of PR in the first 3 days of life. Conclusion Whereas circadian rhythmicity in neonates may result from maternal influence, the increase of amplitude indexes in PR with PCA may be related to physiological maturity. Further studies are needed to elucidate the effect of oxygenation on physiological rhythmicity in neonates.

SUCCESSFUL IMMUNIZATION FOLLOWING CORD BLOOD TRANSPLANTATION IN A CHILD WITH DIAMOND-BLACKFAN ANEMIA

Cord blood transplantation (CBT) has been increasingly used to treat patients with hematological diseases, but active immunizations for patients have not been described. Patients certainly need immunizations following CBT, since transplanted cord blood is naive. The authors previously reported successful hematopoietic reconstitution following cord blood transplantation from an HLA-matched sibling in a transfusion-dependent child with Diamond-Blackfan anemia. No graft-versus-host disease, either acute or chronic, has been observed so far. Here, the authors report that immunological recovery of the patient has been rapid shortly after CBT and immunization has been done successfully. Vaccines (diphtheria, pertussis, tetanus, rubella, measles, and BCG) were administered during 22-34 months post-transplant. Seroconversion to these vaccines was excellent without significant adverse effects. These results indicate that both toxoid and live vaccines have been safely administered in the patient who underwent related cord blood transplantation.

Cord blood CD4(+)CD25(+) regulatory T cells fail to inhibit cord blood NK cell functions due to insufficient production and expression of TGF-beta1.

Although CD4(+)CD25(+) Treg (Treg) cells are known to modulate NK cell functions, the modulation mechanism of these cells in cord blood has not been fully clarified. The purpose of this study was to clarify the mechanism whereby cord blood Treg cells modulate cord NK cells. By performing various cultures of purified NK cells with or without autologous Treg cells, diminished inhibitory effects of cord Treg cells towards cord NK cell functions, including activation, cytokine production, and cytotoxicity, were observed. We also observed lower secretion of sTGF-beta1 and lower expression of mTGF-beta1 by cord Treg cells than by adult Treg cells. These data revealed the capability of adult Treg cells to suppress rhIL-2-stimulated NK cell function by TGF-beta1, both membrane-bound and soluble types. The reduced inhibitory capabilities of cord Treg cells compared with adult Treg cells is thought to be due to insufficient expression of TGF-beta1.

Reading difficulty in school-aged very low birth weight infants in Japan

OBJECTIVE To investigate the prevalence of and the perinatal risk factors related to reading difficulty in school-aged very low birth weight infants (VLBWI) with normal intelligence. METHODS Subjects were 79 Japanese children in the second to fourth grade of elementary school who had been born at very low birth weight and who regularly visited a follow-up clinic at one of four hospitals. All members had a full-scale IQ score of 80 or higher. Perinatal information was obtained retrospectively from medical records. Each subject underwent four reading tasks, testing monomoratic syllable reading, word reading, non-word reading and short sentence reading. Subjects with an SD reading time score greater than 2.0 in two or more tasks were considered to have reading difficulty (RD). Furthermore we investigated the relations between RD and perinatal factors using logistic regression analysis adjusted for potential confounding factors. RESULTS Twenty-five (31.6%) out of 79 subjects had RD. We discovered that treated retinopathy of prematurity (tRoP) was a significant risk factor (adjusted OR=5.80, 95% confidence interval=1.51-22.33). CONCLUSION The rate of RD in school-aged VLBWI was higher than the estimated prevalence of dyslexia in Japan. Even in children with normal intelligence, long-term developmental follow-up including support for reading skills is necessary for VLBWI. Further investigation is desired to elucidate the relations between visual problems and RD in school-aged children.

Blunted heart rate circadian rhythms in small for gestational age infants during the early neonatal period.

Infants born with intrauterine growth restriction are at increased risk for adverse cardiovascular outcomes in neonatal and later life. Although circadian rhythm is a prognostic marker of cardiovascular health, the concern over the circadian rhythm of these infants is rarely observed. To determine the influence of intrauterine growth retardation on the pattern of circadian rhythm, heart rate (HR) circadian rhythmicity was analyzed in 39 small for gestational age (SGA; birth weight and height below <-2.0 standard deviation score [SDS]) and 117 appropriate for gestational age (AGA; >-1.5 to <1.5 SDS) infants within 72 hours of birth using spectral analysis and cosinor analysis. Amplitude, midline estimating statistic of rhythm, and acrophase calculated from circadian rhythm were analyzed with clinical variables. A significant HR circadian rhythm was observed in 23.1% of the SGA and 24.8% of the AGA group without significant differences; however, SGA infants exhibited remarkable smaller amplitudes compared with AGA in all gestational age (GA) groups (p < 0.001). Amplitudes in AGA infants were positively correlated with the GA or body composition relevant variables (p < 0.001, respectively), but not SGA infants. The blunted HR circadian rhythmicity in SGA infants showed in this study might indicate the vulnerability to pathophysiological condition and could potentially refer to cardiovascular disease in later life.

Mission in Sukusuku Cohort, Mie: Focusing on the Feasibility and Validity of Methods for Enrolling and Retaining Participants

Background We investigated the feasibility and validity of and systematized the methods used to enroll and retain participants requiring long-term interdisciplinary collaborations. We carried out this study in the Sukusuku cohort, Mie (SCM), as one of the regional research site of Japan Children’s Study (JCS). Methods A total of 467 families who were screened between December 1, 2004 and December 31, 2005, in the Mie-chuo Medical Center and 2 other hospitals; these families were deemed eligible for the study. Of these, a total of 185 families (39.6%) participated in the 4-month observation. Of these families, 5 dropped out at month 9 of the observation; 9, at month 18; 17, at month 30; and 5, at month 42. The retention rates at 9, 18, 30, and 42 months of observation were 97.3%, 92.4%, 83.2%, and 80.5%, respectively. Reinstatement to a previous job was the most common reason for dropouts. Results We observed that informative consultation notes during observation were beneficial for the retention of participants, and these notes also helped in improving communication between the study subjects and the evaluators during subsequent visits. Conclusions In this study, we did not perform the standard checks for child development alone but also investigated the motivating influence of research partnerships with participants. Further, these visits help maintain the motivation levels of the participants and encourage them to contribute for social causes. The results present integration models that can be applied in future relevant longitudinal cohort studies in Japan.