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Biomedical subjects

N Kondo

Publications and source records attributed to N Kondo.

At least 253 records · Page 14Linked to original sources
PubMed1997

Genomic and mutational analysis of the mitochondrial trifunctional protein beta-subunit (HADHB) gene in patients with trifunctional protein deficiency.

Mitochondrial trifunctional protein (TP), an enzyme of beta-oxidation, is a multienzyme complex composed of four molecules of the alpha-subunit (HADHA) containing the enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase domains and four molecules of the beta-subunit (HADHB) containing the 3-ketoacyl-CoA thiolase domain. An inborn error of this enzyme complex can cause sudden infant death syndrome, acute hepatic encephalopathy or liver failure, skeletal myopathy, or hypertrophic cardiomyopathy. TP deficiency is classified into two different biochemical phenotypes: one represents the existence of both subunits and the lack of only the 3-hydroxyacyl-CoA dehydrogenase activity and the other represents the absence of both subunits and the lack of all three TP activities, although their clinical features are similar. We have identified two Japanese patients with this disorder. Three enzyme activities of TP were undetectable in fibroblasts from these two patients. We detected two mutations in the HADHB gene from two Japanese patients, an exonic single T insertion which created a new cryptic 5' splice site and a G1331A transition (R411 K). Patient 1 was a compound heterozygote, while patient 2 was a homozygote of a G1331A transition.

Animals↗
PubMed1997

Cloning of a cDNA for a 1-aminocyclopropane-1-carboxylate synthase that is expressed during development of female flowers at the apices of Cucumis sativus L.

In cucumber (Cucumis sativus L.) plants, it has been reported that a high correlation existed between the evolution of ethylene from the apices and the development of female flowers. We isolated three distinct cDNA encoding 1-aminocyclopropane-1-carboxylate (ACC) synthase from cucumber. Among of these, only CS-ACS2 mRNA was detected at the apices of gynoecious cucumber in which female flowers were developing. The expression of the CS-ACS2 gene was examined in the apices of three cucumber cultivars (Rensei, Ougonmegami 2-gou and Shimoshirazu) by RNA gel blot analysis. In these cultivars, both the timing and the levels of expression of the CS-ACS2 transcript were correlated with the development of female flowers at the nodes. Furthermore, the timing of the induction of expression of the CS-ACS2 gene at the apex corresponded to that of the action of ethylene in induction of the first female flower at the apex of gynoecious cucumber plants. These results suggest that the development of female flowers might be regulated by the level of CS-ACS2 mRNA at the apex.

Amino Acid Sequence↗
PubMed1997

Combined use of ribotyping, PFGE typing and IS431 typing in the discrimination of nosocomial strains of methicillin-resistant Staphylococcus aureus.

We have previously reported the phenotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) clinical strains isolated in Malaya University Hospital in the period 1987 to 1989 using antibiogram, coagulase typing, plasmid profiles, and phage typing. Here, we report the analysis of the same strains with three genotyping methods; ribotyping, pulsed-field gel electrophoresis (PFGE) typing, and IS431 typing (a restriction enzyme fragment length polymorphism analysis using an IS431 probe). Ribotyping could discriminate 46 clinical MRSA strains into 5 ribotypes, PFGE typing into 22 types, and IS431 typing into 15 types. Since the differences of the three genotyping patterns from strain to strain were quite independent from one another, the combined use of the three genotyping methods could discriminate 46 strains into 39 genotypes. Thus, the powerful discriminatory ability of the combination was demonstrated.

Bacterial Proteins↗
PubMed1997

Marinesco-Sjögren syndrome associated with acute myeloblastic leukemia.

Marinesco-Sjögren syndrome is a rare autosomal recessive disorder characterized by cerebellar atrophy, ataxia, cataracts, short stature and varying degrees of mental retardation. A high incidence of malignant disease associated with this syndrome has not so far been reported. We report the case of a 6-year-old girl affected with Marinesco-Sjögren syndrome, who developed acute myeloblastic leukemia (AML, M2), and whose karyotype was 46,XX,t(8;21),(q22;q22) in bone marrow blasts. This is the first report of Marinesco-Sjögren syndrome associated with malignant disorders.

Brain↗
PubMed1997

Two novel missense mutations in the ATP-binding domain of the adrenoleukodystrophy gene: immunoblotting and immunocytological study of two patients.

Two novel missense mutations, 1939G to A (R518Q) and 2017A to G (Q544R) were identified in Japanese patients with adrenoleukodystrophy (ALD). They are located in exon 6, which encodes part of the putative adenosine triphosphate binding domain of ALD protein. The ALD protein carrying the R518Q mutation was undetectable in fibroblasts, by immunoblot and immunofluorescence analysis, while the Q544R mutation had no apparent effect on the stability and localization of the ALD protein, but is expected to affect its function.

ATP Binding Cassette Transporter, Subfamily D, Mem↗
PubMed1997

Epilepsy in peroxisomal diseases.

PURPOSE: To clarify the electroclinical manifestation of epileptic seizures and the evolution of epilepsy in patients with peroxisomal diseases. METHODS: Retrospective review of the medical records and EEGs of 14 patients with peroxisomal diseases: seven with Zellweger syndrome (ZS), two with neonatal adrenoleukodystrophy (NALD), two with acyl-CoA oxidase deficiency (AOXD), two with bifunctional enzyme deficiency (BFED), and one with rhizomelic chondrodysplasia punctata (RCDP). The diagnoses were made by biochemical analysis and pathological examinations in our laboratory. RESULTS: Patients manifested serious neurologic deficits in the neonatal period or in early or late infancy. Patients with ZS or AOXD had partial motor seizures originating in the arms or legs or corners of the mouth. Their seizures did not culminate in generalized tonic-clonic seizures and were easily controlled by antiepileptic drugs (AEDs). Interictal EEGs of the patients with ZS showed infrequent bilateral independent multifocal spikes, predominantly in the frontal motor cortex and its surrounding regions. The EEGs of patients with AOXD showed interictal fast theta activity, predominantly in the frontocentral regions. Patients with BFED also had partial motor seizures in early infancy, but the seizures were intractable, evolving in one case to myoclonic seizures. Interictal EEGs of patients with BFED showed bilateral independent multifocal spikes that evolved to bilateral diffuse high-voltage slow waves in one case and to a hypsarythmic pattern in another case as the disease progressed. Patients with NALD had intractable tonic seizures or epileptic spasms. Interictal EEGs showed high-voltage slow waves and bilateral independent multifocal spikes, evolving in one patient to a flat pattern. The patient with RCDP, whose interictal EEGs showed frequent multifocal independent spikes, did not have epileptic seizures. CONCLUSIONS: The age of epilepsy onset or the duration of survival is related to the types of seizures occurring in patients with peroxisomal diseases. Neonates or young infants usually have partial motor seizures (facial twitching or clonic convulsions of the arms or legs) of various multifocal origins. Older infants may have generalized seizures at the onset of the disease or evolutionally. Seizure intractability is usually less severe in patients with ZS or AOXD than in patients with NALD or BFED. There is no relation between the electroclinical characteristics of epilepsy and the genetic complementation groups in peroxisomal diseases.

Acyl-CoA Oxidase↗
PubMed1997

Cerebral infarction in incontinentia pigmenti: the first report of a case evaluated by single photon emission computed tomography.

A 2-month-old girl with incontinentia pigmenti presented with acute-onset right-handed focalized seizures and subsequent seizure generalization. Computed tomography, magnetic resonance imaging and single photon emission computed tomography results indicated that she had multiple cerebral infarctions. These findings suggest that incontinentia pigmenti should be included among the neurocutaneous syndromes associated with ischemic strokes in childhood. This is the first report of a case with incontinentia pigmenti associated with cerebral infarction evaluated by single photon emission computed tomography.

Brain↗
PubMed1997

Effect of increased muscle temperature on oxygen uptake kinetics during exercise.

To test whether increased muscle temperature (Tm) would improve O2 uptake (VO2) kinetics, seven men performed transitions from rest to a moderate work rate [below the estimated lactate threshold (LTest)] and a heavy work rate (VO2 = 50% of the difference between LTest and peak VO2) under conditions of normal Tm (N) and increased Tm (H), produced by wearing hot water-perfused pants before exercise. Quadriceps Tm was significantly higher in H, but rectal temperature was similar for the two conditions. There were no significant differences in the amplitudes of the fast component of VO2 or in the time constants of the on and off transients for moderate and heavy exercise between the two conditions. The increment in VO2 between the 3rd and 6th min of heavy exercise was slightly but significantly smaller for H than for N. These data suggest that elevated Tm before exercise onset, which would have been expected to increase O2 delivery and off-loading to the muscle, had no appreciable effect on the fast exponential component of VO2 kinetics (invariant time constant). These data further suggest that elevated Tm does not contribute to the slow component of VO2 during heavy exercise.

Adult↗
PubMed1997

Combinations of IgE values and lymphocyte proliferative responses for consideration of the clinical course of infantile hen's-egg-sensitive atopic dermatitis.

We have attempted a new approach, using peripheral blood mononuclear cells (PBMCs), to predict the clinical course of infantile food-sensitive atopic dermatitis (AD). In this study, we investigated the relationships between the clinical course of infantile hen's-egg-sensitive AD and laboratory data obtained at the early stage of AD, particularly on combinations of specific IgE antibodies to hen's egg and proliferative responses of PBMCs to ovalbumin (OA). Total IgE concentrations, specific IgE antibodies to hen's egg and proliferative responses of PBMCs to OA were measured in 31 hen's-egg-sensitive AD patients within 6 months after development of AD symptoms. After the acquisition of laboratory data, the clinical courses of all patients were followed up for 1 year. The stimulation index of proliferative responses of PBMCs to OA in hen's-egg-sensitive AD patients whose symptoms did not improve was significantly (p < 0.05) higher than that in hen's-egg-sensitive AD patients whose symptoms improved. On the other hand, the radioallergosorbent test (RAST) scores for hen's egg were not statistically different between the two groups. The degree of refractoriness of AD symptoms tended to be higher in the patients who showed a higher total IgE concentration at the beginning of the clinical course than in those who showed a lower one. These results might be attributed to the underlying cause of AD, i.e., a cell-mediated and an IgE-mediated allergy. We concluded that, in addition to total IgE concentrations, combinations of RAST values and lymphocyte proliferative responses to OA are important to predict the clinical course of infantile hen's-egg-sensitive AD.

Allergens↗
PubMed1997

Identification of Dermatophagoides farinae-2-derived peptides and class II HLA molecules recognized by T cells from atopic individuals.

Der f2, the group 2 allergen of Dermatophagoides farinae, is one of the major inhalation allergens in Japan. Using the mixture of a panel of overlapping synthetic peptides that spread over the entire Der f2 molecule, we found that polyclonal Der f2-specific short-term T cell lines prepared from peripheral blood mononuclear cells of 5 individuals allergic to Der f who carry most of the common HLA haplotypes seen in the Japanese population can respond mainly to 7 different peptides. Distribution of the T cell epitopes on Der f2 was not identical with that on Der p2. Five of 7 peptides stimulated T cells of more than 2 donors, regardless of HLA types. Inhibition patterns by anti-HLA class II mAbs were heterogenous in proliferative responses of each cell line, three were mainly inhibited by anti-HLA-DR mAb, and the others were inhibited by anti-HLA-DQ mAb. One of these T cell lines, SM, of which the proliferative response was partially inhibited by anti-HLA-DQ mAb, was cloned. Indeed, the T cell clone SM4.6 was restricted by DQ6 molecules encoded for by an HLA-DRB1*1502-DRB5*0102-DQA1*0103-DQB1*0601 haplotype. These results indicate that patients' T cells recognize Der f2 in association with a variety of HLA-DR or HLA-DQ as antigen-presenting molecules. Thus, although some peptides do have a more potent T cell stimulatory activity than others, the TCR ligands formed with the Der f2 molecule are highly heterogeneous, a factor also noted in Der f1-specific T cell lines in our previous study.

Allergens↗
PubMed1997

Enzymes of ketone body utilization in human tissues: protein and messenger RNA levels of succinyl-coenzyme A (CoA):3-ketoacid CoA transferase and mitochondrial and cytosolic acetoacetyl-CoA thiolases.

We describe the distribution in human tissues of three enzymes of ketone body utilization: succinyl-CoA:3-ketoacid CoA transferase (SCOT), mitochondrial acetoacetyl-CoA thiolase (T2), and cytosolic acetoacetyl-CoA thiolase (CT). Hereditary deficiency of each of these enzymes has been associated with ketoacidosis. Physiologically the two mitochondrial enzymes have different roles: SCOT mediates energy production from ketone bodies (ketolysis), whereas T2 functions both in ketogenesis and ketolysis. In contrast, CT is implicated in cytosolic cholesterol synthesis. We investigated the tissue distribution of these enzymes in humans by quantitative immunoblots and by Northern blots. In most tissues, polypeptide and mRNA levels were proportional. CT and T2 proteins were detected in all tissues examined. CT levels were highest in liver, were 4-fold lower in adrenal glands, kidney, brain, and lung, and were lowest in skeletal and heart muscles. T2 was most abundant in liver but substantial amounts were present in kidney, heart, adrenal glands, and skeletal muscle. SCOT was detected in all tissues except liver: myocardium > brain, kidney and adrenal glands. The relative amounts of T2 and SCOT were similar in all tissues except for liver (T2 > > SCOT) and brain (SCOT > T2). The observed distribution of SCOT, T2, and CT is consistent with current views of their physiologic roles.

Acetyl-CoA C-Acetyltransferase↗
PubMed1997

Biochemical and immunocytochemical properties of peroxisomes and mitochondria in bovine chromaffin cells.

The biochemical and immunocytochemical properties of peroxisomal and mitochondrial beta-oxidation enzymes in bovine adrenal chromaffin cells were investigated. Peroxisomes were detectable by immunofluorescence staining using antibodies against acyl-CoA oxidase, peroxisomal 3-ketoacyl-CoA thiolase and catalase. The mitochondria were abundantly stained with antibody against mitochondrial 3-ketoacyl-CoA thiolase. The biosynthesis and intracellular processing of acyl-CoA oxidase and the peroxisomal 3-ketoacyl-CoA thiolase was slower than that in fibroblasts. The peroxisomal beta-oxidation activities shown by [1-14C] lignoceric acid oxidation were slightly lower than those in fibroblasts, whereas the mitochondrial beta-oxidation activities shown by [1-14C] palmitic acid oxidation were almost identical to those in fibroblasts. Adrenal chromaffin cells are useful materials for investigating the peroxisomal and mitochondrial metabolism of autonomic neurons and may contribute to the clarification of neuronal dysfunction in peroxisomal and mitochondrial disorders.

Acetyl-CoA C-Acyltransferase↗
PubMed1997

Effect of a new hypoglycemic agent, A-4166 [(-)-N-(trans-4-isopropylcyclohexanecarbonyl)-D-phenylalanine], on postprandial blood glucose excursion: comparison with voglibose and glibenclamide.

(-)-N-(trans-4-Isopropylcyclohexanecarbonyl)-D-phenylalanine (A-4166) is a new nonsulfonylurea hypoglycemic agent that lowers blood glucose by stimulating insulin release. In the present study, we examined the effects of A-4166, voglibose (an alpha-glucosidase inhibitor), and glibenclamide (a sulfonylurea) on the postprandial glycemic increase in rats with or without diabetes mellitus. Oral administration of A-4166 (25-100 mg/kg) dose-dependently decreased blood glucose with a rapid onset and short duration in normal rats. On the other hand, glibenclamide (1-4 mg/kg) showed a slower onset of its hypoglycemic action, and voglibose (0.2 mg/kg) had no effect. In the case of postprandial glucose excursion, the carbohydrate-induced increase in blood glucose was reduced by oral administration of either A-4166 or voglibose without causing sustained hypoglycemia in both normal and neonatal streptozotocin-induced diabetic rats. However, the efficacy of voglibose varied with the type of carbohydrate load. Glibenclamide produced a prolonged decrease in blood glucose without any appreciable effect on the initial glucose excursion. After sucrose loading, plasma insulin levels during the initial 1 h were significantly higher in A-4166-treated rats than in control rats, while voglibose completely inhibited the insulin response to sucrose. In glibenclamide-treated rats, an augmented insulin response was not seen. In conclusion, unlike other hypoglycemic agents, A-4166 suppresses postprandial glucose excursions by stimulating the early phase of insulin secretion.

Animals↗
PubMed1997

Two Japanese siblings with Bloom syndrome gene mutation and B-cell lymphoma.

Bloom syndrome (BS) is a rare autosomal recessive genetic disorder characterized by lupus-like erythematous telangiectasia of the face, sun sensitivity, infertility and stunted growth. Upper respiratory tract and gastrointestinal infections are commonly associated with the decreased immunoglobulin levels found in BS patients. Chromosomal abnormalities are hallmarks of the disorder, and high frequencies of sister chromatid exchanges and quadriradial configurations in lymphocytes and fibroblasts are virtually diagnostic. Recently, the causative gene for BS (BLM) has been identified. We encountered and defined a family with a nonsense mutation in BLM. The brother and sister were homozygous for the mutation and both developed B-cell malignant lymphoma in their twenties. These findings indicate the importance of prenatal diagnosis and the detection of BS carriers based on molecular genetic analysis.

Adenosine Triphosphatases↗