Two types of orthostatic dysregulation assessed by diameter of inferior vena cava.

AIMS: Orthostatic dysregulation (OD) is common in adolescents. This study was conducted to evaluate the usefulness of the measurement of the diameter of the inferior vena cava (IVC) for objective assessment of patients with OD. METHODS: Twenty children with OD (median 14 years, range 9-15 years) and 23 age-matched healthy children (median 12 years, range 10-15 years) were enrolled. A diameter of IVC was measured by an abdominal echogram before and after a head-up tilt table testing (HUT). Changes in IVC was assessed by an arbitrary parameter, collapse index (CI) as the following equation: [(maximal IVC diameter in the supine position - maximal IVC diameter in the standing position)/(maximal IVC diameter in the supine position)]× 100. CI was evaluated 4 weeks after treatment with an adrenergic agent. RESULTS: Children with OD demonstrated either higher CI or lower CI compared to that in control children: CI was more than 50 (range 50-71) in 12 patients with OD while that was equal to or less than 0 (range -225 to 0) in eight out of 20 patients. In contrast, CI was between 0 and 50 (range 1-26) in 23 healthy children. Pharmacological treatment induced the normalization in the CI in both higher and lower CI group. CONCLUSION: OD can be classified into two subtypes: by HUT, one is characterized by an increase of IVC diameter while another is characterized by its decrease. Measurement of IVC diameter by HUT is useful to understand the pathophysiology and to assess the efficacy of treatment.

Phagocytosis of heat-killed Staphylococcus aureus by eosinophils: comparison with neutrophils.

Eosinophils are characterized by several functional properties, such as chemotaxis, adhesion, superoxide anion production, and degranulation. In this article, we have studied the role of bacterial ingestion by eosinophils in comparison with that by neutrophils. Eosinophils and neutrophils were purified by using the Percoll gradient method followed by selection with CD16-coated immunomagnetic beads and centrifugation through a Ficoll-Hypaque gradient combined with dextran sedimentation, respectively. Both cells were preincubated with anti-FcgammaRIIa mAb (CD32 mAb), anti-FcgammaRIIIb mAb (CD16 mAb), anti-CR3 (CD11b mAb), or anti-CR1 (CD35 mAb) before being examined for phagocytosis of opsonized heat-killed Staphylococcus aureus (S. aureus). Phagocytosis and production of hydrogen peroxide were simultaneously measured by flow cytometry using S. aureus labeled with propidium iodide and stained with 2',7'-dichlorofluorescein diacetate. Eosinophils showed significantly lower activity than neutrophils in both phagocytosis and hydrogen peroxide production. Phagocytosis by both cells was decreased by heat-inactivated serum. Phagocytosis by neutrophils was significantly inhibited by CD16 mAb and CD32 mAb, whereas that by eosinophils was only inhibited by CD35 mAb. Whereas the mechanism of phagocytosis by neutrophils was mediated by CD16 and CD32, that of eosinophils was modulated by complement receptor 1 (CD35).

Mechanisms underlying acceleration of blood flow recovery in ischemic limbs by macrophage colony-stimulating factor.

Recently we reported that macrophage colony-stimulating factor (M-CSF) can mobilize endothelial progenitor cells (EPCs) from the bone marrow into the peripheral blood, resulting in an increase in the number of blood vessels and augmentation of blood flow in the ischemia-induced legs. M-CSF accelerates neovascularization of ischemic lesions resulting from the mobilization of EPCs. In the present paper, we analyze the mechanisms underling the mobilization of EPCs by M-CSF. M-CSF augments the production of vascular endothelial growth factor (VEGF) from the bone marrow cells, especially from myeloid lineage cells. In vivo administration of anti-VEGF antibody abrogates both the acceleration of the recovery of blood flow in the ischemia-induced limbs by M-CSF and the augmentation of the mobilization of EPCs induced by M-CSF. These results suggest that the M-CSF contributes to rapid recovery of blood flow in ischemic lesions by mobilization of EPCs from the bone marrow through augmentation of VEGF production in the bone marrow and that the VEGF is mainly produced by myeloid lineage cells.

Turner syndrome associated with ulcerative colitis.

UNLABELLED: We report the case of a 7-yr-old girl with Turner syndrome, ulcerative colitis (UC) and coarctation of the aorta. The diagnosis of Turner syndrome was made in early infancy (karyotype analysis 45, X). Growth hormone treatment was started at 3 yr and 2 mo of age. From the age of 4 yr and 5 mo, the patient suffered from persistent diarrhea with traces of blood and intermittent abdominal discomfort. As these symptoms gradually deteriorated, she was referred to our clinic at the age of 7 yr for further evaluation. Barium enema showed aphtha and loss of the fine network pattern in the descending colon and rectum. An endoscopic examination showed ulceration, edema, friability, and erythema beginning in the rectum and extending up to the splenic flexure of the descending colon. The histology of the descending colon area showed severe stromal infiltration of inflammatory cells. These endoscopic findings and the histological findings were consistent with UC. Thus, based on these findings, the patient was diagnosed as having UC. Mesalazine therapy was initiated at this time. The patient is currently being treated with mesalazine (1,000 mg/day) and abdominal symptoms and bloody diarrhea have disappeared. GH therapy was not interrupted during the therapy for UC. Retrospectively, growth hormone improved growth velocity (9 cm/year) during the first year of treatment, however from the age of 4 yr, growth velocity decreased (4-5 cm/yr) in spite of the GH treatment. CONCLUSION: Patients with Turner syndrome and gastrointestinal symptoms should be investigated for inflammatory bowel diseases. Growth velocity is useful for evaluating the presence of inflammatory bowel diseases and other systemic diseases.

Long-term follow-up of a girl with primary aldosteronism: effect of potassium supplement.

UNLABELLED: We followed up a girl with primary aldosteronism for 8 y, which was diagnosed at 6 y of age when she was referred to us for evaluation of heart murmur and growth failure. The diagnosis of bilateral adrenal hyperplasia was made by selective adrenal venous sampling. Following potassium supplement, her retarded growth was corrected dramatically, and she attained a normal adult height. Puberty developed normally and menarche occurred at 12 y of age. Blood pressure was also controlled adequately. Myocardial hypertrophy associated with aortic damage was noted at 13 y of age. Chronic renal failure developed with proteinuria and enlarged renal cysts. CONCLUSION: Serum electrolytes should be included in the evaluation of children with impaired growth. Although primary aldosteronism is a rare occurrence in children, the condition appears to deserve special attention not only from the viewpoint of growth failure and hypokalaemia but from the occurrence of late organ damage to the kidney and heart.

Variant clinical courses of 2 patients with neonatal intrahepatic cholestasis who have a novel mutation of SLC25A13.

Deficiency of citrin due to mutations of the SLC25A13 gene causes not only adult-onset type II citrullinemia, but also neonatal intrahepatic cholestasis. Neonatal intrahepatic cholestasis is a self-limiting condition and spontaneously disappears by 12 months of age without special treatment. The natural history of patients with SLC25A13 mutations is not clear. Two patients with infantile hepatic dysfunction were found to have a novel mutation of the SLC25A13 gene. DNA analyses of SLC25A13 disclosed that the first patient was a compound heterozygote for the Ex16+74_IVS17-32del516 (del516-Ex16/IVS17) and IVS11+1G-->A mutations and the second one a homozygote for the del516-Ex16/IVS17 mutation. It is predicted that the 516-base pair deletion mutation leads to a frameshift from codons 556 to 564, a premature termination at codon 565, and a truncated form of the citrin protein (normal, 675 amino acids). The first patient had disseminated intravascular coagulation associated with hepatic dysfunction in the neonatal period. The other patient had persistent cholestatic jaundice and underwent an operation to rule out bile duct atresia. Without specific treatment, both patients had a favorable clinical course. In conclusion, citrin deficiency resulting from the mutation of SLC25A13 presented variant clinical courses, followed by hypercitrullinemia and intrahepatic cholestasis in infancy. The conditions in the patients were self-limiting and spontaneously disappeared.

Polymorphism of Fc gamma RIIa may affect the efficacy of gamma-globulin therapy in Kawasaki disease.

We evaluated whether there is a possible relationship between the effectiveness of gamma-globulin treatment for patients with Kawasaki disease (KD) and the polymorphism of Fcgamma RIIa, IIIb, and IIIa. Genomic DNA was extracted from whole blood collected from 56 patients with KD who received gamma-globulin treatment. The genotypes for Fcgamma RIIIb-NA(1, 2), Fcgamma RIIa-H/R131, and FcgammaRIIIa-F/V158 were determined to investigate the association between these polymorphisms and the development of coronary lesions (CALs). Twenty-three percent of patients with the HH allele for the Fcgamma RIIa polymorphism progressed to CALs, compared with 60% with the HR and RR alleles. HR and RR alleles may be a predictor of the progression of CALs in KD before the initiation of gamma-globulin therapy.

The role of a mutation of the CXCR4 gene in WHIM syndrome.

We investigated the role of a mutation of the CXCR4 gene in 11-year-old twin sisters with WHIM syndrome. The mutated gene may result in production of the mutant CXCR4 protein causing abnormal apoptosis and migratory function, which are thought to be related to the cause of chronic neutropenia in WHIM syndrome.

Research on promotion of management of children with psychosomatic and psychosocial disorders in Japan.

BACKGROUND: The number of children with psychosomatic and psychosocial disorders has been increasing in Japan. There are, however, few trained pediatricians who have adequate knowledge of the treatment needed. The Research Group on the Promotion of Management of Children with Psychosomatic and Psychosocial Disorders carried out the present study to (i) disseminate knowledge about psychosomatic and psychosocial disorders of children; and (ii) establish a community-based network model to ensure effective communication among relevant institutions. METHODS: To disseminate knowledge of the psychosocial and psychosomatic disorders, the Research Group compiled the Handbook for Psychosomatic Disorders of Children and distributed it to pediatricians throughout Japan. A follow-up questionnaire survey was then carried out. Also, in order to examine the current status of the communication network between pediatricians and the related institutions, the Research Group conducted a questionnaire survey on general pediatricians. RESULTS: Sixty-five percent of the respondents indicated that they were actually using the Handbook. The topics in the Handbook that were most frequently referred to by the respondents were attention deficit hyperactivity disorders, school refusal, eating disorders, and orthostatic dysregulation. Thirty-seven percent of the participants indicated changes in their behavior towards psychosomatic and psychosocial problems. The results of the survey on communication networks found that the pediatricians generally collaborated with different institutions depending on the nature of the problems, such as school refusal and bullying, developmental disorders, child abuse and maltreatment, and others. CONCLUSION: Promotion of the Handbook would greatly contribute to improving the management of children with psychosomatic and psychosocial disorders, together with the construction of the basic network model for management of these children.

Relationship of intracellular magnesium of cord blood platelets to birth weight.

Magnesium (Mg(2+)) has an important role in insulin action, and insulin stimulates Mg(2+) uptake in insulin-sensitive tissues. Impaired biologic responses to insulin are referred to as insulin resistance. Diabetic patients and obese subjects are reported to have intracellular magnesium ([Mg(2+)](i)) deficiency. Many epidemiologic studies have disclosed that restricted fetal growth has been associated with increased risk of insulin resistance in adult life. We studied the relationship of [Mg(2+)](i) in cord blood platelets to birth weight. The subjects were 19 infants who were small for gestational age (SGA) and 45 who were appropriate for gestational age (AGA). By using a fluorescent probe, mag-fura-2, we examined the basal and insulin-stimulated [Mg(2+)](i) of platelets in the cord blood. Cord plasma insulin-like growth factor-1 (IGF-1)and leptin levels were determined with the use of enzyme-linked immunosorbent assay (ELISA). Birth weight was correlated with cord plasma IGF-1 (P < .001) and leptin (P < .005). Mean basal [Mg(2+)](i), but not plasma Mg(2+), was lower in the SGA than in the AGA group (291 +/- 149 micromol/L v 468 +/- 132 micromol/L, P < .001). The basal [Mg(2+)](i) was significantly correlated with the birth weight (P < .001) as well as birth length (P < .001). At 60 seconds after stimulation with insulin, there was no significant difference in stimulated [Mg(2+)](i) between the SGA and AGA groups. Although the SGA group had low [Mg(2+)](i), the platelets had good potentiality to compensate for low [Mg(2+)](i). [Mg(2+)](i) reflects the extent of fetal growth. Decreased [Mg(2+)](i) in SGA might underlie the initial pathophysiologic events leading to insulin resistance.

Intracellular magnesium and insulin resistance.

UNLABELLED: Magnesium, the second most abundant intracellular divalent cation, is a cofactor of many enzymes involved in glucose metabolism. Magnesium has an important role in insulin action, and insulin stimulates magnesium uptake in insulin-sensitive tissues. Impaired biological responses to insulin is referred to as insulin resistance. This review was designed to reach a better understanding of the mechanism involved in the correlation between magnesium and insulin resistance. Intracellular magnesium concentration is low in type 2 diabetes mellitus and in hypertensive patients. In patients with type 2 diabetes an inverse association exists between the plasma magnesium and insulin resistance due to intracellular changes. The suppressed intracellular magnesium concentration may result in defective tyrosine kinase activity and modify insulin sensitivity by influencing receptor activity after binding or by influencing intracellular signaling and processing. Intracellular magnesium deficiency may affect the development of insulin resistance and alter the glucose entry into the cell. CONCLUSIONS: Magnesium is required for both proper glucose utilization and insulin signaling. Metabolic alterations in cellular magnesium, which may play the role of a second messenger for insulin action, contribute to insulin resistance.

Influence of CD36 deficiency on heart disease in children.

BACKGROUND: The physiological role of the CD36 molecule in pediatric heart disease has not been fully investigated. METHODS AND RESULTS: The CD36 antigen in platelets and monocytes was measured by flow cytometry in 189 patients with various heart diseases; 15 (7.9%) had a diagnosis of CD36 deficiency (type I: 2[1 boy, 1 girl], type II: 13 [6 boys, 7 girls]). The prevalence in each heart disease was as follows: group A (congenital heart disease) 7.6% (9/118, type II: 9 [6 boys, 3 girls]); group B (myocardial disease) 20.0% (3/15, I: 1 girl, II: 2[1 boy, 1 girl]), group C (Kawasaki disease) 4.9% (2/41, II: 2 [1 boy, 1 girl]), group D (arrhythmia): 6.7% (1/15, I: 1 boy). Three patients in group B had transient myocardial damage, which was thought to be related to abnormal myocardial long-chain fatty acid metabolism. CONCLUSION: The frequency of CD36 deficiency in childhood heart disease was almost identical to that of healthy individuals. Some patients with CD36 deficiency may be susceptible to myocardial damage in the presence of disadvantageous conditions, such as serious infections or massive steroid therapy.

Measurement of inferior vena cava diameter for evaluation of venous return in subjects on day 10 of a bed-rest experiment.

We evaluated the usefulness of measurements of the inferior vena cava (IVC) diameters on abdominal echograms as an indicator of changes of venous return in subjects with orthostatic intolerance (OI) induced by simulated microgravity. We performed a standing test and recorded the IVC diameters on abdominal echograms in 12 subjects placed on a 20-day 6 degrees head-down-tilt bed-rest experiment. We found that different patterns of changes in IVC diameter occurred in the standing test on day 10 of the experiment; in five subjects with a marginal decrease in pulse pressure, IVC diameters in the upright position were markedly decreased compared with those in the supine position. In five subjects with feelings of discomfort, the IVC diameters in the upright position distended or did not decrease from those in the supine position. These results suggested that the changes in IVC diameter on the standing test indicated the presence of various types of hemodynamic responses of OI caused by simulated microgravity. In this study, we also evaluated changes in body-water compartments by conducting multifrequency bioelectrical impedance analysis. Longitudinal data analysis showed that the total body-water-to-fat-free mass and extracellular fluid-to-fat-free mass ratios decreased during the experimental period and recovered thereafter, and that the ratio of intracellular fluid to fat-free mass decreased during the experiment. No significant difference in changes in body-water compartments was seen among subjects with different patterns of changes in IVC diameters. Measurement of IVC diameter was useful to estimate hemodynamic changes in subjects with OI.