Clinical significance of measurement of resting energy expenditure in childhood

1. Biliary atresia (BA), as a common disease in Japan, and cystic fibrosis (CF), as an extremely uncommon disease in Japan, were selected to assess the clinical significance of measurement of energy expenditure (EE). 2. Energy expenditure was significantly higher in children with BA than in normal children. 3. Measurement of EE in BA lead to clues to resolving its mechanism by novel assessment of interleukin-6 and leptin. 4. Energy expenditure in children with CF is also higher, but this has been addressed by nutritional intervention with additional calories. 5. Individualization of EE measurement is necessary in the analysis of pathological mechanisms and nutritional management of patients with both common and uncommon diseases.     

Genetic mapping of genes regulating the thymus size in back-cross rats between the laboratory BUF/Mna strain and the MITE strain derived from the wild rat, Rattus norvegicus

The thymoma prone BUF/Mna (B) rat is a useful model for Studying the genes responsible for thymus enlargement during the stage of young growth. Among the strains of rats, B rats have the largest thymuses at al stages of life. A locus, Ten-1 , which contributes to thymus enlargement in back-cross (BC) rats between the B and WKY/NCrj (W) strains, was mapped on chromosome 1. To determine the precise location of the bus, (B×(B×MITE)F1) BC rats were generated by crossing the B strain with the Inbred MITE (M) strain, which was established from captured, Japanese wild rats, and were examined by linkage study using polymerase chain reaction with 67 microsatellite markers. Linkages with thymus enlargements were found In genotypes of seven markers, BSIS, LSN, MYL2, IGF2, PBPC2, D1Mgh11 , and D1Mit6 , by X^2-test and Student's t -test, which confirmed the presence of the genetic locus associated with thymus enlargement, Ten-1 , in this region. Paradoxically, a suppressive locus, Tsu-1 , to thymus enlargement was also found on chromosome 3, showing linkages of phenotype of the small thymus with genotypes of SCN2A, CAT D3Mit16 , and D3Mit13 . By analyses of mapmaker/exp and mapmaker/qtl, Ten-1 was mapped at 4.6 cM proximal from IGF2 locus on chromosome 1 and Tsu-1 at 4.0 cM proximal from CAT locus on chromosome 3, respectively.     

Calcineurin-mediated BAD Ser155 dephosphorylation in ammonia-induced apoptosis of cultured rat hippocampal neurons

We previously reported that ammonia induced apoptosis in cultured rat hippocampal neurons with moderate increases in the intracellular calcium concentration and decreases in phospho-BAD levels. Since this suggested the involvement of calcineurin in the apoptosis, the effects of calcineurin inhibitors, 1 microM cyclosporin A and 1 microM FK506, on the ammonia-induced neuronal apoptosis were tested. Both of the inhibitors abolished the neuronal apoptosis assessed by double staining with Hoechst 33258 and anti-neurofilament antibody, and the ammonia-induced decrease in phospho-BAD Ser(155) level. Thus, calcineurin appeared to be involved in the dephosphorylation of BAD at the sites including Ser(155) in ammonia-induced apoptosis.     

Masked excitatory action of noradrenaline on rat islet β-cells via activation of phospholipase C

The effect of noradrenaline (NE) on rat islet -cells was examined. NE reduced insulin secretion from rat islets exposed to extracellular solutions containing glucose at 5.5 or 16.6 mM. In islets treated with pertussis toxin (PTX), however, NE increased insulin secretion. The NE-induced augmentation of insulin secretion was inhibited by prazosin. In intact islets, NE increased phospholipase C (PLC) activity, an effect that was prevented by treatment of islets with U-73122. NE elevated intracellular [Ca²⁺] ([Ca²⁺]_i) in isolated -cells independently of PTX. Although this NE effect was inhibited by prazosin, phenylephrine did not mimic it. The [Ca²⁺]_i response to NE was also prevented by the treatment of cells with U-73122. NE produced depolarization of -cells followed by nifedipine-sensitive action potentials. NE reduced the whole-cell membrane currents through ATP-sensitive K⁺ channels (K_ATP), responsible for the depolarization. This NE effect was prevented by treatment of -cells with U-73122 or BAPTA/AM. Although at least some of our results imply the presence of ₁-adrenoceptors, -cells were not stained by a polyclonal IgG antibody recognizing all adrenergic ₁-receptor subtypes so far identified. These results suggest that an interaction of NE with an unknown type of receptor activates rat islet -cells via a PLC-dependent signal pathway. This effect is, however, masked by the inhibitory action via a PTX-sensitive pathway also activated by NE.     

Association between childhood oral allergy syndrome and sensitization against four major pollens (Japanese cedar, orchard grass, short ragweed, alder)]

BACKGROUND/AIM: Although OAS (oral allergy syndrome) during childhood is believed to be rare, it seems to be increasing these days. METHODS, SUBJECTS: We here report 16 cases of childhood OAS, which were diagnosed, in our division. In addition to these reports, we investigated the rate of sensitization against four major pollens (Japanese cedar, orchard grass, short ragweed, alder) among 1067 pediatric patients with allergic diseases (median age: 4 years old) in our division. The sensitization was examined by IgE CAPRAST and above class 2 was judged as positive sensitization. RESULTS: OAS in childhood differs from that in adulthood in some ways. One is that childhood OAS does not always accompany with pollinosis. The most frequent allergen in our study was kiwi fruits followed by tomato, orange and melon among these patients. The sensitization rate against alder was equivalent as that against orchard grass and short ragweed, but less than that against Japanese cedar. CONCLUSION: Childhood OAS may have different mechanisms from adulthood OAS which almost always accompanies with pollinosis or latex allergy.     

Morphometric analysis of the development of sexual dimorphism of the mouse pelvis

Sex differences in the innominate bone of C57BL/Tw mice were studied morphometrically from the day of birth to 120 days of age. In neonatal male and female mice, a small cartilaginous spine was found on the basal part of ischium. This process disappeared in males within 24 hours after birth, whereas in females it remained until at least 30 days. Other sexual differences in the pubis and the ischium appeared at 30 and 120 days, respectively. The pubis in female mice was longer and thinner than that in the males, and the ischium in male mice was shorter and thicker than that in the females. Thirty-day-old female mice treated neonatally with testosterone or 5 alpha-dihydrotestosterone possessed pubic bones shorter and thicker than those of the age-matched untreated females. Pubes in male mice castrated at the day of birth were thinner than those in intact males. These findings suggest that the shape of the innominate bone is transformed to the male type under the influence of early postnatal androgen.