Kaichi Kida

Renal Net Glucose Release In Vivo and Its Contribution to Blood Glucose in Rats

This study describes the contribution of de novo glucose synthesis by the kidney to blood glucose homeostasis in rats. The net glucose release by the kidney in vivo was measured by an isotope-dilution method, which calculated the extent of dilution of injected [(14)C]glucose by glucose newly synthesized in the kidney. The extent of dilution was determined from the difference between the decrease of the actual blood glucose concentration and that of the radioactivity of [(14)C]glucose, after injecting [(14)C]glucose into functionally hepatectomized rats. The results indicate that the net glucose release by the kidney in vivo in normal fed rats was 0.75+/-0.13 mg/dl per min, and that its contribution to blood glucose was 25.9+/-5.0%. When unilateral nephrectomy was performed, under the same conditions, renal net glucose release was one-half of that in rats with two intact kidneys, which indicates the quantitative accuracy of the isotope-dilution method employed in this study. In rats starved for 24 h, the renal net glucose release increased to 0.99+/-0.08 mg/dl per min. Diabetic rats showed a remarkably higher renal net glucose of 2.28+/-0.33 mg/dl per min, which was 360% of the normal level. Treatment of diabetic rats with insulin, restored the renal net glucose release to the normal level. In acidotic rats, renal net glucose release was as great as 1.03+/-0.15 mg/dl per min, which suggests that the acid-base balance participates in control of renal glucose output. Measurements every 6 h throughout the day showed that glucose was supplied from the kidney at a constant rate without any circadian rhythm. These data suggest that renal gluconeogenesis is of physiological importance in the maintenance of homeostasis of blood glucose.

Incidence of Type 1 diabetes mellitus in children aged 0–14 in Japan, 1986–1990, including an analysis for seasonality of onset and month of birth: JDS study

Aims To detect the incidence of childhood Type 1 diabetes mellitus (DM) (0–14 years) in Japan and to find out whether there is a seasonal pattern in the onset of disease and month of birth of children with diabetes.

Differences in the Contribution of HLA-DR and -DQ Haplotypes to Susceptibility to Adult- and Childhood-Onset Type 1 Diabetes in Japanese Patients

To clarify heterogeneity in Japanese adult-onset type 1 diabetes, we analyzed the HLA-DR and -DQ haplotypes, depending on the clinical phenotype, and compared them with those in childhood-onset type 1 diabetes (CO). The patients in a previously reported Ehime Study were divided into subgroups by the mode of onset of diabetes: 68 acute-onset type 1 diabetic patients (AO) and 28 slowly progressive type 1 diabetic patients (SO). HLA haplotypes were compared with those of 80 CO patients and 190 control subjects. Two major susceptible HLA haplotypes in the Japanese, DRB1*0405-DQB1*0401 (DR4) and DRB1*0901-DQB1*0303 (DR9), were significantly increased in the AO and CO groups, but only DR9 was increased in the SO group. AO subjects had a higher frequency of DR9 than CO subjects. Accordingly, the DR9:DR4 frequency increased with increasing age of onset. Another susceptible haplotype, DRB1*0802-DQB1*0302 (DR8), was involved only in the CO group. Analysis of haplotype combinations revealed that DR4 and DR9 had significant dosage effects on the AO and CO groups (P < 0.0001), but only DR9 had such an effect in the SO group (P < 0.03). These results suggest differences in the contribution of HLA class II haplotypes to susceptibility of type 1 diabetes depending on the clinical phenotype and also indicate that HLA class II haplotypes may be associated with the onset age of type 1 diabetes.

Immunogenetics of early-onset insulin-dependent diabetes mellitus among the Japanese: HLA, Gm, BF, GLO, and organ-specific autoantibodies — the J.D.S. study

The Japan Diabetes Society (JDS) conducted a multicenter study on the immunogenetics of early-onset insulin-dependent diabetes mellitus (IDDM) of the Japanese. Human leukocyte antigen (HLA), properdin factor B (BF), immunoglobulin heavy-chain complex (Gm), and glyoxalase of erythrocytes (GLO) were typed, and organ-specific autoantibodies, including islet cell antibody (ICA), were assayed in 159 Japanese IDDM patients and their family members and in 258 healthy Japanese controls. The HLA-DRw9 phenotype and HLA-Bw61/DRw9 haplotype were significantly increased among the patients with autoantibodies other than ICA but with no autoimmune diseases (RR = 5.84, cP less than 0.001; and RR = 7.45, P less than 0.001), whereas the HLA-DR4 phenotype and HLA-Bw54/DR4 haplotype were significantly increased in those without either the autoantibodies or autoimmune diseases (RR = 2.64, cP less than 0.001; and RR = 4.55, P less than 0.001). The HLA-DR4 phenotype was significantly increased in the patients with autoimmune thyroid diseases (RR = 6.21, cP less than 0.05). In all groups of patients, the HLA-DR2 phenotype was significantly decreased, and the relative risk of the HLA-DRw9/DR4 genotype was highest among all HLA-DR genotypes. No significant association was found between HLA type and the duration or incidence of ICA. Gm types of g and gft were significantly increased in the patients with the autoantibodies (RR = 2.11, P less than 0.05; and RR = 34.11, P less than 0.05), whereas the BF-F phenotype was significantly decreased in the patients either with or without autoantibodies (RR = 0.43, P less than 0.05; and RR = 0.46, P less than 0.05). There was no association between IDDM and GLO type. These data indicate that immunogenetic bases underlying IDDM of the Japanese are heterogeneous, as are those in Caucasians.

Synergism in insulin-like effects of molybdate plus H2O2 or tungstate plus H2O2 on glucose transport by isolated rat adipocytes

The effect of molybdate, tungstate, molybdate plus H2O2 or tungstate plus H2O2 on 3-O-methylglucose (3-O-MG) uptake was studied in isolated rat adipocytes to investigate whether these agents possess an insulin-like action. High concentrations (10-30 mM) of molybdate or tungstate significantly stimulated the uptake of 3-O-MG while 1 mM of the metaloxides did not. The combination of 1 mM molybdate and 1 mM H2O2, or 1 mM tungstate and 1 mM H2O2 induced striking stimulation of the uptake of 3-O-MG in a synergistic manner, whereas 1 mM H2O2 alone showed only a small effect. The effect of metaloxides plus H2O2 (1 mM) and the effect of insulin (20 nM) were not additive, and both effects were ATP or energy dependent based on experiments using KCN. These results indicate that a weak insulin-like effect of molybdate or tungstate is potentiated synergistically with H2O2, presumably by producing peroxocompounds. Based on the present findings, these new agents may be useful for investigating the mechanism of insulin action and may indicate a new class of drugs for diabetes mellitus.

Clinical study of epilepsy with severe febrile seizures and seizures induced by hot water bath.

We followed five cases with severe febrile seizures (FS) with early onset and seizures induced by hot water bath, indicating severe myoclonic epilepsy in infancy (SME) or the peripheral form of SME. These cases, however, had far better clinical courses than that of SME or the peripheral form of SME. These cases were characterized by: (a) severe FS with early onset and seizures induced by hot water bath; (b) a lack of myoclonic seizures; (c) no psychomotor deterioration; (d) no underlying disorders or signs of brain insult on neurologic and laboratory examination; (e) relatively successful seizure control; (f) none of the severe EEG abnormalities seen in SME and the peripheral form of SME; and (g) a positive family history of convulsive disorders.

The pathogenic role of the NMDA receptor in hyperthermia-induced seizures in developing rats

Hyperthermia-induced seizures (HS) in rats have been used as a model of febrile seizures. Activation of the N-methyl-D-aspartate (NMDA) receptor by increased extracellular glutamate (Glu) in the cortex during hyperthermia may be involved in the induction of HS and HS kindling. To confirm this hypothesis, the effects of a potent blocker of the NMDA receptor, MK-801, on the threshold and pattern of HS were evaluated. The threshold temperatures for rats given 0.1 (low dose) and 0.5 (high dose) mg/kg MK-801 (i.p.) for the first time were 41.6 degrees C (39.7-42) (median, range) and 42.0 (41.2-42.0), respectively, which were significantly higher than the 40.5 (39.4-41.2) for rats without MK-801 administration (P < 0.01). The recurrent occurrence of HS suppressed the increase in the threshold temperature with age, and changed the seizure from partial to generalized seizures (HS kindling), whereas these effects of recurrent HS on the threshold and pattern of HS were inhibited by the high dose (0.5 mg/kg) of MK-801. MK-801 blocks HS and HS kindling. The activation of the NMDA receptor during hyperthermia plays an important role in the induction of HS and HS kindling.

A case of Kabuki make-up syndrome with central diabetes insipidus and growth hormone neurosecretory dysfunction

A case of a 6 year old boy with Kabuki make‐up syndrome with central diabetes insipidus and growth hormone neurosecretory dysfunction is reported. Magnetic resonance imaging revealed abnormal findings of the pituitary gland and stalk. Good catch‐up growth was obtained by treatment with growth hormone. These findings suggest that hypothalamic‐pituitary dysfunction might be involved in Kabuki make‐up syndrome.

Insulin-like growth factor I (IGF-I) delays the onset of diabetes in non-obese diabetic (NOD) mice

It has been shown that prophylactic exogenous insulin treatment prevents the development of insulin-dependent diabetes mellitus (IDDM) in animal models and humans. In this study, we examined whether the development of diabetes and insulitis in female non-obese diabetic (NOD) mice could be affected by prophylactic administration of insulin-like growth factor I (IGF-I), which shares structural homology with insulin and has insulin-like metabolic effects. Two experiments which differed in duration and dosage of IGF-I treatment were carried out. In the first experiment, animals were treated from 4 to 9 weeks of age with IGF-I (17.9 nmol/day at 4-5 weeks of age and 35.9 nmol/day at 6-9 weeks of age) and observed up to 34 weeks of age. In the second experiment, the animals were treated from 4 to 34 weeks of age with IGF-I (1.79 nmol/day at 4-5 weeks of age, 3.59 nmol/day at 6-9 weeks of age, and 5.38 nmol/day at 10-34 weeks of age). The former treatment could significantly delay the onset of diabetes (P < 0.05) and decrease the insulitis score at 10 weeks of age (P < 0.01). On the other hand, the latter treatment did not affect the incidence of diabetes, the age at onset or the insulitis score. Our results suggest that the IGF-I treatment at the early age may provide protection against autoimmune beta-cell destruction in NOD mice.

The influence of blood gas changes on hyperthermia-induced seizures in developing rats

Fever induces seizures in infants with febrile convulsions or epilepsy. Hyperpnea induced by fever may contribute to the induction of these seizures. In order to examine this possibility, we evaluated the effect of changes in arterial blood gas tension on hyperthermia-induced seizures in developing rats. Electrical seizure discharges were induced by application of infra-red rays on the skull of rats under mechanical ventilation with different respiratory conditions. There was positive correlation between pCO(2) and the seizure threshold (ST) defined as a latency from the start of hyperthermia to the occurrence of seizures: ST (seconds, s) = 2.36 pCO(2) + 0.05 (R(2) = 0.80, P < 0.001). Seizure duration (SD) was longer at lower pCO(2) level: 18 (6-33) (median, range) s at pCO(2) ranging from 23 to 26 mmHg vs. 0 (0-7) s at pCO(2) ranging from 35 to 57 mmHg (P < 0.01). Hypoxia significantly increased ST: 84 (61-100) s at P0(2) ranging from 53 to 76 mmHg vs. 60 (51-72) s at P0(2) ranging from 87 to 131 mmHg (P < 0.01). Hyperoxia prolonged SD: 27 (10-30) s at P02 ranging from 100 to 170 mmHg vs. 9 (0-23) at P0(2) ranging from 53 to 93 mmHg (P < 0.02). Hypocarbia caused by fever-induced hyperpnea probably contributes to the generation of fever-induced seizures.