Takashi Sakano

Mizoribine in steroid-dependent nephrotic syndrome of childhood.

Abstract. We evaluated a 1-year course of a newly developed immunosuppressant, mizoribine (at a dosage of 3 mg/kg body weight per day), in nine children with steroid-dependent nephrotic syndrome. Steroid treatment could be discontinued in two patients and the maintenance dosage of steroid could be reduced to less than half of that given before mizoribine therapy in a third. There were no beneficial effects in the remaining six patients. No adverse effects of mizoribine were observed during the course of therapy.

Intracellular Ca2+ mobilization in immature and more mature U937 induced to differentiate by dimethyl sulfoxide or phorbol myristate acetate

Intracellular Ca2+ mobilization in U937 cells was studied. Stimulation of immature U937 cells with leukotriene B4 (LTB4) increased intracellular Ca2+ levels, whereas stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP) failed to increase intracellular Ca2+ levels. U937 cells cultured with 1.5% dimethyl sulfoxide (DMSO) for 4 days (DMSO-U937 cells) responded to LTB4 and possessed the ability to respond to fMLP. U937 cells cultured with 1 ng/ml phorbol myristate acetate (PMA) for 4 days (PMA-U937 cells) lost the ability to respond to LTB4, although they responded to fMLP. Treatment of DMSO-U937 cells with 100 ng/ml PMA for 3 min suppressed intracellular Ca2+ increase induced by LTB4 and fMLP. The fMLP-induced Ca2+ rise in PMA-U937 cells was not suppressed by a further treatment with 100 ng/ml PMA. DMSO-U937 cells responded to inositol 1,4,5-trisphosphate (IP3), indicating that IP3 functions as a messenger of intracellular Ca2+ mobilization from endoplasmic reticulum in U937. The magnitude and duration of the rise in Ca2+ induced by IP3 in DMSO-U937 cells treated with 100 ng/ml PMA for 3 min were similar to those of the controls. When DMSO-U937 cells were Ca2+-depleted, addition of Ca2+ resulted in a transient overshoot of Ca2+ influx. However, the transient overshoot was not observed, when PMA-U937 cells were tested. These results indicate that Ca2+ efflux in PMA-U937 cells is increased by an activated exit pump, which may be directly or indirectly related to the functional state of PMA-U937 cells.

Superoxide dismutase activity of T lymphocytes and non-T lymphocytes

Superoxide dismutase (SOD, EC 1.15.1. l), which catalyzes the dismutation of superoxide anion, O;-, to less toxic hydrogen peroxide and molecular oxygen, is an ubiquitous enzyme in oxygen-metabolizing cells and serves to protect them from the potentially harmful effects of this reactive free radical [ 11. Clinically, SOD activity has been extensively determined in peripheral blood cells in various conditions [2-71. It was reported that peripheral lymphocytes of human blood have higher SOD activity than do granulocytes [g-lo]. The purpose of this study is to extend this observation and to differentiate between the SOD activities of T and non-T lymphocytes.

Serum concentrations of cortisone and cortisol in premature infants

To determine the relationship between biological active cortisol and its inert metabolite cortisone accurately in premature infants, serum cortisone and cortisol concentrations were measured by reversed-phase high-performance liquid chromatography (HPLC) in a group of 232 premature infants and in a control group of 127 children and 88 adults. In the control group, serum cortisone concentrations were greater than serum cortisol levels during the first 2 months after birth; cortisol levels were higher than cortisone levels after 2 months of age. However, in premature infants, serum cortisone concentrations were greater than serum cortisol levels even after the first 2 months, and total concentrations of cortisone and cortisol were equal to those in controls. Results were then analyzed according to the equivalent gestational age of premature infants. Cortisone was predominant in premature infants older than 32 weeks of equivalent gestational age, but cortisol was higher than cortisone from equivalent gestational age 24 to 31 weeks. These findings suggest that the ability of premature infants to secrete glucocorticoids resembled that of normal controls. Also, the fetal zone of the cortex, which is associated with a predominance of cortisone, remained functional in premature infants for a longer time than in control infants. Our findings that in premature infants cortisone was predominant compared with cortisol and the sum of cortisone and cortisol was equal to that in the controls indicate that cortisone cannot be disregarded whenever the cortisol level is estimated, although cortisone itself is recognized to be biologically inactive. Simultaneous measurement of serum cortisone and cortisol concentrations is important when adrenocortical function is being determined, especially in premature infants.

Leukotriene B4 metabolism in neutrophils of patients with chronic granulomatous disease: phorbol myristate acetate decreases endogenous leukotriene B4via NADPH oxidase-dependent mechanism

Abstract. We studied the effect of phorbol myristate acetate (PMA) on endogenous leukotriene B4 (LTB4) metabolism of calcium ionophore A23187‐stimulated human neutrophils. Preincubation of normal neutrophils with PMA significantly suppressed the recovery of endogenous LTB4 induced by A23187. PMA did not suppress the recovery of LTB4 produced by neutrophils from patients with chronic granulomatous disease (CGD), which is known to be defective in NADPH oxidase activation to produce reactive oxygen species (ROS). PMA inhibited the formation of ω‐oxidation products of LTB4, but enhanced arachidonic acid release in normal and CGD neutrophils. Furthermore, 5‐lipoxygenase activity of 10000 times g supernatants from normal neutrophils pretreated with PMA was equivalent to that of the controls. Decrease in LTB4 recovery was not attributed to the suppression of the intracellular Ca2+ increase. Thus, it is suggested that reactive oxygen species (ROS) produced by PMA may directly affect endogenous LTB4 and convert it into metabolite(s) distinct from ω‐oxidation products.

A case of carbamoyl phosphate synthetase 1 deficiency presenting symptoms at one month of age

Carbamoyl phosphate synthetase 1 deficiency (CPS1D) is an autosomal recessive disorder of the urea cycle which causes hyperammonemia. Two forms of CPS1D are recognized: a lethal neonatal type and a less severe, delayed onset type. Neonatal CPS1D cases often present their symptoms within the first days of life. Delayed onset type were adolescents or adults, and infantile cases were rare. We report a case of CPS1D in a boy who developed symptoms at one month of age. He showed excellent response to treatments including continuous hemodialysis, drugs and a low-protein diet. His development and weight gain were good at the last follow-up at 1 year and three months of age. Molecular assay of the CPS1 gene demonstrated that the patient was heterozygous for c.2407C>G (R803G: maternal) in exon 20 and c.3784C>T (R1262X: paternal) in exon 32. Our clinical experience suggests that CPS1D could be one of the causes of hyperammonemia in early infantile cases.

VACCINE-ASSOCIATED POLIOMYELITIS IN AN INFANT WITH AGAMMAGLO BULINEMIA

Abstract. Sakano, T., Kittaka, E., Tanaka, Y., Yamaoka, H., Kobayashi, Y. and Usui, T. (Department of Paediatrics, Hiroshima University Hospital and Hiroshima City Hospital, Hiroshima, Japan). Vaccine‐associated poliomyelitis in an infant with agammagiobulinemia. Acta Paediatr Scand, 69:549, 1980.—We describe a female infant with agammaglobulinemia who contracted vaccine‐associated poliomyelitis. Poliovirus type 2 was isolated from the initial stool specimen. In our patient, temporary changes in the cerebrospinal fluid resembled those in patients without immunodeficiencies, although gammaglobulin therapy had not yet been started. Pleocytosis was observed for a short time after viremia, but soon there was a return to normal without antibody production.

本邦において初めて流行が確認された小児のhuman metapneumovirus感染症の臨床的, 疫学的解析

Human metapneumovirus (hMPV) was newly discovered as a pathogen in 2001 and is thought to be associated with respiratory disease. To elucidate the prevalence and clinical significance of hMPV among children, we investigated the positive cases of hMPV-RNA by reverse transcription-polymerase chain reaction (RT-PCR) in their nasopharyngeal specimens collected from January to August 2003 in Hiroshima Prefecture, Japan. Our prospective study revealed 77 hMPV-positive cases among 377 children with acute respiratory diseases. Clinical diagnoses of 77 hMPV-positive cases were as follows; bronchitis (33.8%), pneumonia (24.7%), acute respiratory illness (19.5%), asthmatic bronchitis (11.7%) and bronchiolitis (5.2%). The most common symptoms were cough (97.4%), high fever (94.8%) and rhinorrhea (76.6%). Most of the hMPV-positive cases were identified in the spring (between March and May), indicating the presence of an epidemic of hMPV infection in Hiroshima Prefecture. Phylogenetic analysis of the amplified F gene of hMPV isolates revealed that hMPV strains were divided into two genotypes and that their simultaneous circulation occurred within the same epidemic area of Hiroshima Prefecture.

A case of Menkes syndrome with cataracts

A 2-year and 9-month-old boy with Menkes syndrome is reported. In addition to the typical features of this syndrome our patient had bilateral cataracts. The relation between abnormal copper metabolism and cataract is discussed.

Neonatal pertussis presenting as acute bronchiolitis: direct detection of the Bordetella pertussis genome using loop-mediated isothermal amplification

We report a 28-day-old female infant with pertussis presenting as severe acute bronchiolitis with cyanosis. On admission, the patient’s symptoms were similar to those of acute bronchiolitis. However, occasional apneic episodes with cyanosis and peripheral lymphocytosis suggested neonatal pertussis and prompted us to examine the presence of Bordetella pertussis using loop-mediated isothermal amplification (LAMP) based on the insertion sequence IS481. LAMP of the nasopharyngeal and intratracheal aspirates was positive for B. pertussis and a diagnosis of neonatal pertussis was made. As the clinical features of pertussis in neonates and early infancy are not characteristic, LAMP is a useful tool for rapid diagnosis of B. pertussis infection.