Akihiko Kinugasa

Fatty liver and its fibrous changes found in simple obesity of children.

Of 299 obese children who visited our obesity clinics, 36 were found to have elevated levels of serum transaminases by routine laboratory examination. Liver biopsy was carried out in 11 children. Based on the criteria of Adler and Schaffner (1979), the biopsy specimens were studied histologically. As a result, fatty liver (Group I) was observed in three patients, fatty hepatitis (Group II) in two, fatty fibrosis (Group III) in five, and fatty cirrhosis (Group IV) in one. The duration of obesity, but not its degree, was considered to be related to the extent of fibrosis. Accordingly, we concluded that the fatty liver of simple obesity in children may progress to liver cirrhosis and that childhood obesity should be treated as early as possible.

The Effect of Carnitine on Ketogenesis in Perfused Livers from Juvenile Visceral Steatosis Mice with Systemic Carnitine Deficiency

Juvenile visceral steatosis (JVS) mice have been reported to have systemic carnitine deficiency, and the carnitine concentration in the liver of JVS mice was markedly lower than that of controls (11.6 ± 2.6 versus 393.5 ± 56.4 nmol/g of wet liver). To evaluate the role of carnitine in mitochondrial β-oxidation in liver, we examined the effects of carnitine on ketogenesis in perfused liver from control and JVS mice. In control mice, ketogenesis was increased by the infusion of 0.3 mM oleate, but not by L-carnitine. In contrast, although ketogenesis in JVS mice was not increased by the infusion of oleate, it was increased 2.5-fold by the addition of 1000μM L-carnitine. Addition of 50, 100, and 200 μM L-carnitine increased ketogenesis in a dose-dependent manner. The infusion of 0.3 mM octanoate or butyrate increased ketogenesis in a carnitine-independent fashion in both control and JVS mice. These findings suggest that endogenous long chain fatty acids from accumulated triglycerides may be used as substrates in the presence of carnitine in JVS mice. The relationship between ketogenesis and free carnitine concentration was examined in livers from JVS mice. Ketogenesis increased as free carnitine levels increased until concentrations exceeded about 100 nmol/g of wet liver (340 μM). The free carnitine concentration required for half-maximal ketone body production in liver of JVS mice was 45μM (13 nmol/g of wet liver), which corresponds to a Km value of carnitine palmitoyltransferase I. We conclude that carnitine is a rate-limiting factor for β-oxidation in liver only when the carnitine level in liver is very low.

Molecular basis of intermittent maple syrup urine disease : novel mutations in the E2 gene of the branched-chain α-keto acid dehydrogenase complex

AbstractThe E2 gene of the branched-chain α-keto acid dehydrogenase (BCKDH) complex was studied at the molecular level in three patients with intermittent maple syrup urine disease (MSUD). All three patients had higher BCKDH activity than did those with the classical phenotype. In the first patient, a single base substitution from A to G in intron 8 created a new 5′ splice site and caused an insertion of 126 nucleotides between exons 8 and 9 by activating an upstream cryptic 3′ splice site in the same intron. The predicted mRNA encoded a truncated protein with 282 amino acids including 4 novel ones at the carboxyl terminus, compared with the normal protein with 421 amino acids. In vitro, the region from the patient but not from a normal control was recognized and was recovered as a novel exon, indicating that the single substitution was responsible for incorporation of the region into mRNA. This mutation probably supports an exon definition model in which the spliceosome recognizes a 3′ splice site and then scans downstream for an acceptable 5′ splice site, thereby defining an exon. The second patient was homozygous for a G to T transversion at nucleotide 1463 in exon 11, which predicted a substitution of the termination codon by a leucine residue and the addition of 7 extra amino acids at the carboxyl terminus. For each mutation, these two patients were homozygous and their parents were heterozygous. The third patient was a compound heterozygote for a C to G transversion at nucleotide 309 in exon 4 and a G to A transition at nucleotide 1165 in exon 9, causing an Ile-to-Met substitution at amino acid 37 and a Gly-to-Ser substitution at amino acid 323, respectively. Taken together, these results indicate that the molecular basis of intermittent phenotype MSUD in some patients can be due to mutations in the E2 gene, giving rise to a low but significant residual activity of the BCKDH complex.

The Japanese Study Group of Insulin Therapy for Childhood and Adolescent Diabetes (JSGIT): initial aims and impact of the family history of type 1 diabetes mellitus in Japanese children

Abstract: The Japanese Study Group of Insulin Therapy for Childhood and Adolescent Diabetes (JSGIT) was established in July 1994 with the chief aim to improve the quality of therapy for type 1 diabetes in children, an entity far less common in Japan than in Europe. We proposed four initial research topics: (i) to determine the current status of medical care and glycemic control in Japanese children with type 1 diabetes mellitus; (ii) to standardize the measurement of hemoglobin A1c; (iii) to establish a registry of a large cohort of patients in order to enable prospective studies to improve the quality of therapy for children with type 1 diabetes in Japan; and (iv) to enable participants of the JSGIT to hold a workshop twice annually.

Deficiency of glucose-6-phosphate dehydrogenase found in a case of hepatic fructose-1,6-diphosphatase deficiency.

Summary: The first case of fructose-1,6-diphosphatase (FDPase) deficiency in Japan showed a decreased activity of glucose-6-phos-phate dehydrogenase (G6PD) in the liver, white, and red blood cells. In the enzymatic study of G6PD which was partially purified from red cells, the following characteristics were observed in the enzyme of the patient. 1) The G6PD activity of the patient was reduced to 17% of normal, but no evidence of a hemolytic episode was found in his past and family history. 2) In the investigation of G6PD of the patient, no abnormalities were observed in its enzymatic parameters such as electrophoretic mobility, Km for G6P and NADP, Ki for NADPH, the utilization of 2-deoxy G6P and deamino NADP, heat-stability, and pH curves. 3) The dissociation constants of red blood cell G6PD for NADP and NADPH, which were obtained from the investigations on the reactivation of cold-inactivated G6PD at 37°C, were about 3 times higher in the patient as compared to the values of the normal controls.Based on these findings, it might be concluded that the G6PD deficiency found in the red blood cells of this case of a FDPase deficiency is a unique variant, which could not be characterized by using only the method recommended by a World Health Organization (WHO) scientific group. Considering that the abnormality observed in the G6PD of this patient was a decrease hi the affinity of the enzyme for its coenzymes, the dissociation constants for the coenzymes in reactivation process might be another important kinetic parameter in characterizing the G6PD deficiency.Speculation: The red cell G6PD of a case of FDPase deficiency showed a decreased enzymatic activity and a lowered affinity for its coenzymes in reactivation process. Although it is strongly suggested that these two rare enzyme deficiencies take place in an individual coincidentally, a possible relationship of the two enzyme deficiencies should be considered. Further studies on these enzyme deficiencies now appear necessary to learn more about this association.

Type I glycogen storage disease with vasoconstrictive pulmonary hypertension

SummaryA case of glycogen storage disease (GSD) type I with vasoconstrictive pulmonary hypertension is described.

Alloimmune Neonatal Neutropenia in Monozygous Twins: High‐dose Intravenous Gammaglobulin Therapy

ABSTRACT. An indirect immunofluorescence test using a flow cytometer (FACS420) was useful for detection of antineutrophil antibodies (anti‐NA2 antibodies) in a case of monozygous twins with alloimmune neonatal neutropenia. When high‐dose intravenous gammaglobulin (300 mg/kg for five consecutive days) was given to one twin, the increase in neutrophils was not obvious. Although neutropenia persisted for about three months, no infections were observed in either of the twins.

The Relationship in Japanese Infants between a Genetic Polymorphism in the Promoter Region of the Insulin-Like Growth Factor I Gene and the Plasma Level

Background: Evidence is accumulating that the promoter region of the insulin-like growth factor I (IGF-I) gene polymorphism and low levels of IGF-I are associated with type 2 diabetes, cardiovascular disease and birth weight; however, the number of wild-type alleles is different in each country. Objectives: This study aimed to examine the 737/738 marker, a cytosine–adenine repeat in the promoter region of the IGF-I gene polymorphism, and plasma IGF-I levels in Japanese infants and analyze the genetic background. Methods: Data were collected for 15 months in Kyoto Prefectural University of Medicine. The body composition parameters of all infants were determined at birth. At 5 days after birth, we took blood samples to measure the product size of the promoter region of the IGF-I gene polymorphism and plasma IGF-I. Results: In a population-based sample of 160 subjects, 6 different alleles and 16 genotypes were identified in the promoter region of the IGF-I gene polymorphism. The existence of a 196-bp allele has proved to result in a low plasma IGF-I level, a small head and chest circumference (p < 0.05) and no significant for premature birth, short-birth height and low-birth weight. Conclusions: This is the first study showing the role of the promoter region of the IGF-I gene polymorphism and the level of plasma IGF-I and body composition parameters in Japanese infants. Our results suggest genetical influence on prenatal growth and serum IGF-I levels.

Effect of sports activity on carnitine metabolism Measurement of free carnitine, γ-butyrobetaine and acylcarnitines by tandem mass spectrometry

The effects of sports activity on carnitine metabolism were studied using mass spectrometry. Serum levels of free carnitine, acylcarnitines (acetylcarnitine, propionylcarnitine, C4-, C5- and C8-acylcarnitine) and gamma-butyrobetaine, a carnitine precursor, were determined by tandem mass spectrometry in liquid secondary ion mass ionization mode. The coefficients of variation at three different concentrations were 2.8-7.9% for gamma-butyrobetaine, and 1.2 to approximately 6.7% for free carnitine. The recoveries added to serum were 109.1% for gamma-butyrobetaine, 89.3% for free carnitine. Sports activity caused increased serum levels of gamma-butyrobetaine, acetylcarnitine, C4- and C8-acylcarnitines and decreased serum levels of free carnitine. This method requires a small amount of sample volume (20 microl of serum) and short total instrumental time for the analysis (1 h for preparation, 2 min per sample for mass spectrometric analysis). Therefore, this method can be applied to study carnitine metabolism under various conditions that affect fatty acid oxidation.

Therapeutic effects of human leukocyte interferon on chronic active hepatitis B in children

Seven children with chronic active hepatitis (CAH) and one child with persistently abnormal results of liver function tests due to hepatitis B virus (HBV) infection were treated with human leukocyte interferon (Hu-IFN). Five of them were positive for eAg and two of the three who were measured for DNA polymerase (DNAP) activity in sera showed moderate elevations of its levels. Hu-IFN was injected intramuscularly daily or once weekly at doses of 0.05–1 x 106 IU. The total dose per patient varied from 10.5–54 x 106 IU. After administration of Hu-IFN, rapid loss of eAg was observed in two of the five eAg patients, and DNAP activity reverted to normal ranges in the two patients with moderate elevations of its levels. One of the patients who lost eAg has retained normal serum glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase levels for more than 2 years after therapy with Hu-IFN. Serial hepatic biopsies were performed in only one patient. In the second biopsy, 3 months after therapy with Hu-α-IFN, infiltration of inflammatory cells in the portal region was improved compared with earlier findings. Immediate and/or prolonged adverse side effects were not observed during or after administration of Hu-α-IFN. For the present, we propose these six conditions for use of Hu-α-IFN in children with HBV infection. Children should: (a) be more than 1 year old; (b) have abnormal liver function for more than 6 months; (c) have a liver biopsy demonstrating CAH; (d) have moderate elevation of DNAP activity; (e) be eAg positive; and (f) be unresponsive to other treatments.