Automated screening system for purine and pyrimidine metabolism disorders using high-performance liquid chromatography

An automated screening system for purine and pyrimidine metabolism disorders using high-performance liquid chromatography (HPLC) with column switching is described. The system consists of a reversed-phase column, a cation-exchange column, a column switch, four sets of ultraviolet absorbance detectors, a microcomputer and other conventional equipment. As this system permits the simultaneous determination of urinary orotic acid, uracil, dihydrouracil, pseudouridine, xanthine, 2,8-dihydroxyadenine and succinyladenosine, it offers a useful method for the detection of orotic aciduria, dihydropyrimidine dehydrogenase deficiency, diphydropyrimidinuria, xanthinuria, adenine phosphoribosyltransferase deficiency and adenylosuccinase deficiency.     

Transient expression of bile-duct-specific cytokeratin in fetal mouse hepatocytes

The differentiation of hepatocytes and biliary epithelial cells has been histochemically analyzed with anti-calf cytokeratin antiserum in the fetal mouse liver. Almost all young fetal hepatocytes transiently express bile-duct-specific cytokeratin; subsequently, the strong staining of the cytokeratin is confined to progenitor cells of intrahepatic biliary epithelial cells around portal veins. These results suggest that all fetal hepatocytes are bi-potent in terms of the differentiation of mature hepatocytes and intrahepatic bile-duct cells, and that the microenvironment around portal veins plays an important role in bile-duct differentiation. Large periportal hepatocytes continue to stain weakly for cytokeratin until 2 weeks after birth, although the number of positive hepatocytes decreases with development. The differentiation of bile ducts from periportal hepatocytes may continue for 2 weeks after birth.     

The development of emotion regulation ability between the ages of 13 and 18 months in Japanese infants during the strange situation as a function of mothers' styles of emotion expression

The purposes of this study were two-fold. First, it compared Japanese infants' (N=129) abilities to regulate emotions at 13 months and 18 months of age, using the Strange Situation procedure. Second, it examined the relationship between the development of emotion regulation and the mother's emotion expression style as assessed by the Emotion Expression Style Questionnaire (EESQ). The total number of subjects who successfully completed all 8 episodes of the Strange Situation procedure increased significantly during the aging between 13 and 18 months of age, indicating that as a group these infants increased their ability to cope with stressful situations. However, infants who had mothers with negative emotion expression styles did not show greater capacity for emotion regulation at 18 months. These findings suggest that the development of emotion regulation is mediated by the mother's emotion expression style.     

Molecular phytogeny of conifers using RFLP analysis of PCR-amplified specific chloroplast genes

We investigated the molecular phylogeny of conifers using restriction endonuclease fragment length polymorphism of six polymerase chain reaction-amplified chloroplast genes — frxC, rbcL, psbA, psbD, trnK, and 16S. We detected 227 total site changes among species, representing 23, 26, 38, 48, 67, and 25 site changes in frxC, psbA, psbD, rbcL, trnK and 16S, respectively. The mean nucleotide substitution was 10.75% (SD 0.573) among species in five families. Forty maximally parsimonious trees were obtained using the Wagner parsimony method, and a 50% majority-rule consensus tree was obtained from them. Data analysis produced similar basic patterns when both the Wagner parsimony and the neighbor-joining methods were applied, and the main lineages were clearly separated. Taxaceae and Cephalotaxaceae species were used as the out-groups when applying Wagner parsimony methods. With the Wagner method, the consistency index was 0.510, the retention index was 0.879, and tree length was 435 steps. Our results indicated that Cupressaceae and Taxodiaceae are closely related families and that Sciadopitys verticillata is the basal lineage of Cupressaceae and Taxodiaceae. The neighbor-joining tree is similar to the 50% majority-rule consensus of the 40 Wagner parsimony trees except for the position of Keteleeria daversifolia, the Picea and Cedrus group, and the divergence within Cupressaceae.     

Isolation of cDNA for a Plasma Membrane H+-ATPase from Guard Cells of Vicia faba L.

cDNA encoding the plasma membrane H⁺-ATPase of guard cells ofVicia faba L. was isolated. The clone encoded a 105-kDa polypeptide(956 amino acids) that was 79–85% identical in terms ofamino acid sequence to other plant H⁺-ATPases. High levels ofmRNA explain the high H⁺-ATPase activity of these plasma membranes. (Received December 24, 1994; Accepted April 12, 1995)     

Protective Effects of Pyridoxal Phosphate Against Glucose Deprivation-Induced Damage in Cultured Hippocampal Neurons

Abstract: When hippocampal cultures were deprived of glucose, massive release of lactate dehydrogenase (LDH), an indicator of neuronal death, occurred via NMDA receptor activation. Addition of pyridoxal phosphate (PLP; 1 and 10 µ M ) inhibited this LDH release in a concentration-dependent manner. Prior exposure to PLP evoked more potent inhibitory effects on LDH release compared with those treated at the onset of glucose deprivation. Furthermore, PLP inhibited the reduction of intracellular content of pyruvate induced by glucose deprivation, which was accompanied by the reversal of intracellular ATP depletion. A noteworthy elevation of extracellular glutamate in response to glucose deprivation was completely reversed by addition of PLP. Aminooxyacetic acid, a potent inhibitor of PLP-dependent enzymes, antagonized the effects of PLP on LDH release, pyruvate production, and ATP formation. These results suggest that PLP protects neurons from glucose deprivation-induced damage by enhancing the formation of energy-yielding products and relieving extracellular load of glutamate. The observed phenomena further indicate that PLP might be used prophylactically against neuronal death induced by metabolic disorders.     

Novel mutation at the initiation codon in the Norrie disease gene in two Japanese families

We have identified a new mutation of Norrie disease (ND) gene in two Japanese males from unrelated families; they showed typical ocular features of ND but no mental retardation or hearing impairment. A mutation was found in both patients at the initation codon of exon 2 of the ND gene (ATG to GTG), with otherwise normal nucleotide sequences. Their mothers had the normal and mutant types of the gene, which was expected for heterozygotes of the disease. The mutation of the initiation codon would cause the failure of ND gene expression or a defect in translation thereby truncating the amino terminus of ND protein. In view of the rarity and marked heterogeneity of mutations in the ND gene, the present apparently unrelated Japanese families who have lived in the same area for over two centuries presumably share the origin of the mutation.     

Strategic differences in thermal adaptation between two Drosophila species,D. virilis and D. immigrans

Summary Preadult viability and developmental time at four different temperatures, heat and cold resistances of adult flies, effects of acclimatization on heat resistance, and preferred temperature of adult flies were compared between two species of Drosophila, D. virilis and D. immigrans. Four Japanese local populations were surveyed for each species. As compared with immigrans, virilis was higher in its ability to tolerate both heat and cold stresses and was viable over a broader temperature range. On the other hand, immigrans revealed a superior ability to acclimatize and a rigid preference for gradually changing thermal environment. Differences between geographical populations are remarkable for heat tolerance in virilis and cold tolerance in immigrans. In conclusion, thermal adaptation of virilis seems to be based on the high tolerance to extreme temperatures and that of immigrans mainly on the behavioural preference for viable temperatures.     

Spontaneous occurrence of heat-stable somatic antigen variants in Bacillus thuringiensis

Heat-stable somatic antigen (HSSA) variants were isolated from Bacillus thuringiensis strain T84A1-A by antiserum-mediated selection. Substantial differences in HSSAs were clearly shown between variants and the parent strain by HSSA agglutination tests, Ouchterlony tests and precipitin-halo-formation (PHF) tests of extracellular HSSAs, although a 'one way'cross-reaction was evident. The frequency of HSSA variants in the population was < 10^-4, as determined by PHF tests on antiserum-agar plates. Heat-stable somatic antigen variants showed no alteration in flagellar antigenic structure and in 30 phenotypic characteristics. The insecticidal activity of HSSA variants was on the level with that of the parent strain, when tested with larvae of three lepidopterous species.