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N Kondo

Publications and source records attributed to N Kondo.

At least 163 records · Page 9Linked to original sources
PubMed1999

Isolation, characterization and mutation analysis of PEX13-defective Chinese hamster ovary cell mutants.

We isolated peroxisome biogenesis mutants ZP128 and ZP150 from rat PEX2 -transformed Chinese hamster ovary (CHO) cells, by the 9-(1'-pyrene)nonanol/ultraviolet method. The mutants lacked morphologically recognizable peroxisomes and showed a typical peroxisome assembly-defective phenotype such as a high sensitivity to 12-(1'-pyrene)dodecanoic acid/UV treatment. By means of PEX cDNA transfection and cell fusion, ZP128 and ZP150 were found to belong to a recently identified complementation group H. Expression of human PEX13 cDNA restored peroxisome assembly in ZP128 and ZP150. CHO cell PEX13 was isolated; its deduced sequence comprises 405 amino acids with 93% identity to human Pex13p. Mutation in PEX13 of mutant ZP150 was determined by RT-PCR: G to A transition resulted in one amino acid substitution, Ser319Asn, in one allele and truncation of a 42 amino acid sequence from Asp265 to Lys306 in another allele. Therefore, ZP128 and ZP150 are CHO cell lines with a phenotype of impaired PEX13.

Amino Acid Sequence↗
PubMed1999

Molecular analysis of the gene encoding a novel transglycosylative enzyme from Alteromonas sp. strain O-7 and its physiological role in the chitinolytic system.

We purified from the culture supernatant of Alteromonas sp. strain O-7 and characterized a transglycosylating enzyme which synthesized beta-(1-->6)-(GlcNAc)2, 2-acetamido-6-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-2- deoxyglucopyranose from beta-(1-->4)-(GlcNAc)2. The gene encoding a novel transglycosylating enzyme was cloned into Escherichia coli, and its nucleotide sequence was determined. The molecular mass of the deduced amino acid sequence of the mature protein was determined to be 99,560 Da which corresponds very closely with the molecular mass of the cloned enzyme determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular mass of the cloned enzyme was much larger than that of enzyme (70 kDa) purified from the supernatant of this strain. These results suggest that the native enzyme was the result of partial proteolysis occurring in the N-terminal region. The enzyme showed significant sequence homology with several bacterial beta-N-acetylhexosaminidases which belong to family 20 glycosyl hydrolases. However, this novel enzyme differs from all reported beta-N-acetylhexosaminidases in its substrate specificity. To clarify the role of the enzyme in the chitinolytic system of the strain, the effect of beta-(1-->6)-(GlcNAc)2 on the induction of chitinase was investigated. beta-(1-->6)-(GlcNAc)2 induced a level of production of chitinase similar to that induced by the medium containing chitin. On the other hand, GlcNAc, (GlcNAc)2, and (GlcNAc)3 conversely repressed the production of chitinase to below the basal level of chitinase activity produced constitutively in medium without a carbon source.

Amino Acid Sequence↗
PubMed1999

Defective PEX gene products correlate with the protein import, biochemical abnormalities, and phenotypic heterogeneity in peroxisome biogenesis disorders.

Peroxisome biogenesis disorders (PBD) comprise three phenotypes including Zellweger syndrome (ZS) (the most severe), neonatal adrenoleucodystrophy, and infantile Refsum disease (IRD) (the most mild), and can be classified into at least 12 genetic complementation groups, which are not predictive of the phenotypes. Several pathogenic genes for PBD groups have been identified, but the relationship between the defective gene products and phenotypic heterogeneity has remained unclear. We identified a mutation in the PEX2 gene in an IRD patient with compound heterozygosity for a missense mutation and the known nonsense mutation detected in ZS patients. In transfection experiments using the peroxisome deficient CHO mutant, Z65 with a nonsense mutation in the PEX2 gene, we noted the E55K mutation had mosaic activities of peroxisomal protein import machinery and residual activities of peroxisomal functions, including dihydroxyacetone phosphate acyltransferase and beta oxidation of very long chain fatty acids. The nonsense mutation severely affects these peroxisomal functions as well as the protein import. These data suggest that allelic heterogeneity of the PEX gene affects the peroxisomal protein import and functions and regulates the clinical severity in PBD.

Catalase↗
PubMed1999

Kinetics of oxygen uptake during supine and upright heavy exercise.

It is presently unclear how the fast and slow components of pulmonary oxygen uptake (VO(2)) kinetics would be altered by body posture during heavy exercise [i.e., above the lactate threshold (LT)]. Nine subjects performed transitions from unloaded cycling to work rates representing moderate (below the estimated LT) and heavy exercise (VO(2) equal to 50% of the difference between LT and peak VO(2)) under conditions of upright and supine positions. During moderate exercise, the steady-state increase in VO(2) was similar in the two positions, but VO(2) kinetics were slower in the supine position. During heavy exercise, the rate of adjustment of VO(2) to the 6-min value was also slower in the supine position but was characterized by a significant reduction in the amplitude of the fast component of VO(2), without a significant slowing of the phase 2 time constant. However, the amplitude of the slow component was significantly increased, such that the end-exercise VO(2) was the same in the two positions. The changes in VO(2) kinetics for the supine vs. upright position were paralleled by a blunted response of heart rate at 2 min into exercise during supine compared with upright heavy exercise. Thus the supine position was associated with not only a greater amplitude of the slow component for VO(2) but also, concomitantly, with a reduced amplitude of the fast component; this latter effect may be due, at least in part, to an attenuated early rise in heart rate in the supine position.

Adult↗
PubMed1999

A simple technique for anatomical slow pathway ablation in atrioventricular nodal reentrant tachycardia.

The slow pathway potential or the slow potential serves as a useful marker in catheter ablation of the slow pathway. However, an anatomical approach without recording of these potentials is also an effective way to cure atrioventricular nodal reentrant tachycardia (AVNRT). Moreover, the origin of these potentials is a matter of controversy. We compared 2 approaches to ascertain whether or not recording of these potentials is necessary in eliminating the slow pathway and to estimate the usefulness of the simple anatomical approach. The study population consisted of 24 patients with a conventional approach (Group P) and 19 patients with an anatomical approach (Group A). In group A, the ablation site was determined by fluoroscopy, which was the lowest one-third of the area between the His bundle electrogram recorded position and the coronary sinus orifice at the right anterior oblique view, and just in front of and above the coronary sinus orifice also posterior to the His catheter at the left anterior oblique view where the His catheter was seen tangentially. The slow pathway was successfully ablated in all patients without any complications, including more than first-degree AV block. Although there were no significant differences in total energy or number of applications between the 2 groups, the procedure time was significantly shorter in group A (p < 0.01). In conclusion, recording of the slow pathway potential or the slow potential is not always necessary for slow pathway ablation in the treatment of AVNRT. Because our anatomical approach was performed simply, effectively and safely, it is recommended for the slow pathway ablation of AVNRT.

Adolescent↗
PubMed1999

[Renal angiomyolipoma with a tumor thrombus extending into the right atrium--a case report].

We present a case of spontaneous rupture of renal angiomyolipoma with a tumor thrombus extending from the right renal vein and inferior vena cava to the right atrium. A 41-year-old woman, previously in good health, was referred to our hospital with right flank pain. Computed tomography showed fat densities in both tumor and thrombus. Other imaging examinations also demonstrated a large right renal mass (18 cm in diameter), a long tumor thrombus (13 cm in length) and a small left renal tumor (1.5 cm in diameter). Right nephrectomy and en-bloc removal of the intra caval and intracardiac tumor thrombus were performed on cardiopulmonary bypass. It was pathologically diagnosed as an angiomyolipoma without tuberous sclerosis. At present, three years after surgery the patient is doing well, showing neither metastasis nor increase of the left renal angiomyolipoma. To our knowledge, our case seems to be the 3rd case report of renal angiomyolipoma with a tumor thrombus extending to the right atrium. We conclude that renal angiomyolipoma even with an intra cardiac tumor thrombus can be resected safely and successfully.

Adult↗
PubMed1999

[Public health nurses' disaster responses for intractable neurological patients at home].

OBJECTIVE: This paper describes the 1995 Hanshin-Awaji Earthquake experience of the local public health nurses. The purpose of the study was to identify problems regarding assistance of intractable neurological patients at home during and after the earthquake and to discuss ways to improve future local disaster responses by public health nurses for those patients. METHODS: Approximately 2 hours of a group interview of public health nurses from 2 public health centers in Kobe City was conducted in August, 1996. Interview data was collected via audio-tape and transcribed. The data was organized according to phases of the earthquake. The acute phase of the earthquake disaster ended within 72 hours. The data was then analyzed to identify problems in assisting intractable neurological home patients in order to discuss disaster responses by public health nurses. RESULTS: There was a delay in confirming the safety of and providing needed assistance for intractable neurological patients at home by public health nurses. During the first 3 days after the earthquake, the majority of public health nurses were unable to commute to work due to the shutdown of transportation systems. In addition, nurses, who were able to come to work, were preoccupied with treating earthquake casualties and distributing medical supplies. Other factors associated with the delay included the following: lack of a registration list for intractable neurological patients at home; lack of close contacts between public health nurses and patients, and between public health nurses and patient support groups; and sparing nurses for guiding volunteers and for coordinating between shelters and hospitals. CONCLUSION: Measures to improve future disaster responses are as follows: a) teaching patients and their families how to safeguard against disaster; b) preparing registration lists; c) establishing support networks and cooperating with network members; and d) upon disaster, assigning some nurses to assess the needs of patients.

Disaster Planning↗
PubMed1999

[Development and evaluation of parent-related quality of life questionnaires for asthmatic children and their parents or caregivers--evaluation of treatment process with sustained-release theophylline dry syrup].

A quality of life (QOL) questionnaire for asthmatic children and their parents or caregivers was shown to exhibit reliability, factorial validity and possibility for application study in our previous report. The aim of this study was to examine longitudinal study of the questionnaires, including changes of QOL, responsibility to asthmatic symptoms, consistency with conventional asthma scores and clinical outcomes during treatment with theophylline dry syrup for about three months. Overall QOL scores increased significantly (p < 0.01) with improvement in clinical outcomes. Longitudinal changes of QOL were compared with differences (after-before) and changes of ratio [(after-before/before)] in QOL by correlation analysis between differences of asthma scores. Changes of ratio in QOL were reflected by the clinical outcomes. Results of investigation of correlation between differences in asthma scores and changes of ratio in QOL domains were considered as follows. Physical domain was correlated with asthma symptoms, given the moderate correlation (rho = 0.497). Social and family domains showed fair correlation (rho = 0.382 - 0.384 respectively), both domains were hard to correlate with differences in asthma scores. Emotional domain showed fair correlation (rho = 0.264) for reflecting family's emotion. Poor correlation (rho = 0.071) was observed in individual growth domain which was necessary to evaluate for longer term. Changes of ratio in QOL responded significantly (p < 0.01) to improved and worst-unchanged groups which were categorized by the differences in asthma scores. In conclusion, QOL questionnaires showed longitudinal validity for clinical outcomes and responsibility to asthmatic symptoms. It yields useful information for understanding how asthmatic symptoms affect parents or caregivers and investigating what treatments should be prescribed for the patients with asthma.

Administration, Oral↗
PubMed1999

[Development of parent-rated quality of life questionnaire for asthmatic children and their parents or caregivers--reliability and factorial validity].

We developed a questionnaire form on quality of life (QOL) designed for data entry by parents or caregivers of asthmatic children, which consisted of five domains: physical, social, family, emotional, and individual growth domains. QOL scores were determined according to the five-point scale by which one point was given for maximal impairment and five points for no impairment. The form included 23 questions for children under the age of four and 31 questions for children over the age of four. This study examined reproducibility, reliability, and factorial validity of the form. The numbers of asthmatic children, whose symptoms of asthma attacks had been stable for the 2 weeks before this study, were as follows: eight children under the age of four; and 26 children over the age of four. The intra-class correlation coefficients for these two categories of children were 0.879 and 0.793, respectively; therefore, reproducibility was shown. The values of Cronbach's alfa for the total scores of QOL were 0.6329 to 0.8829 in 102 asthmatic children, 40 healthy children, and 12 non-asthmatic children, e.g., children affected by cold. Therefore, internal consistency was shown. The rank-orders of the replies to the questions associated with the physical, social, family, and emotional domains other than the individual growth domain decreased significantly (p < 0.05) in asthmatic children as compared with healthy or non-asthmatic children. Factor analysis confirmed the five established domains and each facets therein at the cumulative variance of 60% or higher. In conclusion, this questionnaire form on QOL of asthmatic children was considered to have reproducibility, constitutional reliability, and factorial validity, to be applicable at the time of medication, and to be useful in investigating approaches for the management of bronchial asthma and the targeting of treatment.

Asthma↗
PubMed1999

[A case of metastatic liver tumors from prostatic cancer responding to intra-arterial infusion chemotherapy with CDDP and ifosfamide using implantable port].

A 65-year-old man was admitted to our hospital complaining of upper abdominal pain, nausea and appetite loss during the treatment for the prostatic carcinoma. Computed tomography revealed multiple liver metastases. The patient was treated by intra-arterial infusion chemotherapy with, cisplatinum (CDDP) and Ifosfamide using an implantable port. The metastatic lesions were significantly decreased in size and number but CR was not achieved. CDDP was ceased at the total dose of 960 mg. The patient died due to brain metastases 20 months after the start of intra-arterial chemotherapy.

Adenocarcinoma↗
PubMed1998

Increased activity of oleate-dependent type phospholipase D during actinomycin D-induced apoptosis in Jurkat T cells.

Apoptosis is an active form of cell death that can be induced by a wide variety of agents and conditions. In response to actinomycin D, hydrogen peroxide (H2O2), or TNF-alpha, Jurkat T cells underwent typical apoptosis. Phospholipase D (PLD) activity in intact cells determined by phosphatidylbutanol generation was up-regulated by these agents. The PLD activation was in a time-dependent manner during apoptosis. It was also shown that the PLD activity measured by using exogenous substrate in the lysate from apoptotic cells was higher than that in the lysate from control untreated cells. The PLD activity in lysate from control untreated cells was stimulated by unsaturated fatty acids (UFA), but not by guanosine 5'-O-(3-thiotriphosphate). However, the PLD activity in the apoptotic cell lysate was no longer enhanced by the addition of oleate, suggesting that the increased PLD activity during apoptosis was attributed to the PLD of UFA-dependent type, but not the small G protein-dependent one. In fact, the release of free UFA was increased during apoptosis. The caspase inhibitors, z-DEVD and z-VAD, effectively suppressed PLD activation and apoptosis, but UFA release was unaffected. These results suggest the possibility that UFA-dependent type PLD may be implicated in apoptotic process in Jurkat T cells. This is the first demonstration that the PLD of UFA-dependent type would be involved in cellular responses.

Apoptosis↗
PubMed1998

Newly identified Chinese hamster ovary cell mutants are defective in biogenesis of peroxisomal membrane vesicles (Peroxisomal ghosts), representing a novel complementation group in mammals.

We isolated peroxisome biogenesis-defective mutants from Chinese hamster ovary cells by the 9-(1'-pyrene)nonanol/ultraviolet (P9OH/UV) method. Seven cell mutants, ZP116, ZP119, ZP160, ZP161, ZP162, ZP164, and ZP165, of 11 P9OH/UV-resistant cell clones showed cytosolic localization of catalase, a peroxisomal matrix enzyme, apparently indicating a defect of peroxisome biogenesis. By transfection of PEX cDNAs and cell fusion analysis, mutants ZP119 and ZP165 were found to belong to a novel complementation group (CG), distinct from earlier mutants. CG analysis by cell fusion with fibroblasts from patients with peroxisome biogenesis disorders such as Zellweger syndrome indicated that ZP119 and ZP165 were in the same CG as the most recently identified human CG-J. The peroxisomal matrix proteins examined, including PTS1 proteins as well as a PTS2 protein, 3-ketoacyl-CoA thiolase, were also found in the cytosol in ZP119 and ZP165. Furthermore, these mutants showed typical peroxisome assembly-defective phenotype such as severe loss of resistance to 12-(1'-pyrene)dodecanoic acid/UV treatment. Most strikingly, peroxisomal reminiscent vesicular structures, so-called peroxisomal ghosts noted in all CGs of earlier Chinese hamster ovary cell mutants as well as in eight CGs of patients' fibroblasts, were not discernible in ZP119 and ZP165, despite normal synthesis of peroxisomal membrane proteins. Accordingly, ZP119 and ZP165 are the first cell mutants defective in import of both soluble and membrane proteins, representing the 14th peroxisome-deficient CG in mammals, including humans.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1998

Human PEX1 cloned by functional complementation on a CHO cell mutant is responsible for peroxisome-deficient Zellweger syndrome of complementation group I.

The peroxisome biogenesis disorders (PBDs), including Zellweger syndrome (ZS) and neonatal adrenoleukodystrophy (NALD), are autosomal recessive diseases caused by defects in peroxisome assembly, for which at least 10 complementation groups have been reported. We have isolated a human PEX1 cDNA (HsPEX1) by functional complementation of peroxisome deficiency of a mutant Chinese hamster ovary (CHO) cell line, ZP107, transformed with peroxisome targeting signal type 1-tagged "enhanced" green fluorescent protein. This cDNA encodes a hydrophilic protein (Pex1p) comprising 1,283 amino acids, with high homology to the AAA-type ATPase family. A stable transformant of ZP107 with HsPEX1 was morphologically and biochemically restored for peroxisome biogenesis. HsPEX1 expression restored peroxisomal protein import in fibroblasts from three patients with ZS and NALD of complementation group I (CG-I), which is the highest-incidence PBD. A CG-I ZS patient (PBDE-04) possessed compound heterozygous, inactivating mutations: a missense point mutation resulting in Leu-664 --> Pro and a deletion of the sequence from Gly-634 to His-690 presumably caused by missplicing (splice site mutation). Both PBDE-04 PEX1 cDNAs were defective in peroxisome-restoring activity when expressed in the patient fibroblasts as well as in ZP107 cells. These results demonstrate that PEX1 is the causative gene for CG-I peroxisomal disorders.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1998

Peroxisome biogenesis disorders: identification of a new complementation group distinct from peroxisome-deficient CHO mutants and not complemented by human PEX 13.

Ten complementation groups of generalized peroxisome biogenesis disorders (PBD), (excluding rhizomelic chondrodysplasia punctata) have been identified using complementation analysis. Four of the genes involved have been identified using two different methods of (1) genetic functional complementation of peroxisome deficient CHO cell mutants and (2) homology searches for human dbEST, based on yeast genes involved in peroxisome biogenesis (PEX genes). We report here the first identification of a new complementation group which is genetically different from peroxisome deficient CHO mutants. There were no complementations by the human PEX 13 gene. The nature of the related gene is being investigated.

Animals↗
PubMed1998

Molecular basis of selective IgG2 deficiency. The mutated membrane-bound form of gamma2 heavy chain caused complete IGG2 deficiency in two Japanese siblings.

Patients with IgG2 deficiency have recurrent sinopulmonary infections caused by Pneumococcus and Hemophilus. Hereditary and selective IgG2 deficiency was suspected in two Japanese siblings whose serum IgG2 levels were under detection limits, while other serum levels of immunoglobulin subclasses were within normal ranges. Expression level of spontaneous germline Cgamma2 transcript was normal, but that of the spontaneous mature Cgamma2 transcript was greatly decreased in the patients' PBMCs, suggesting the presence of a defect at or after the class switch to Cgamma2. We sequenced the Cgamma2 gene region, and in both patients a homozygous one-base insertion (1793insG) was present in exon 4 of the Cgamma2 gene, just upstream from the alternative splice site for M exons. The mutant membrane-bound gamma2 heavy chain loses the transmembrane domain and the evolutionarily conserved cytoplasmic domain. Considering several lines of evidence showing that intact expression of the membrane-bound heavy chain is essential for a normal response of B cells and production of secreted immunoglobulin in mice, we concluded that 1793insG is responsible for selective and complete IgG2 deficiency in these two siblings. This is the first documentation of a mutation in human selective IgG2 deficiency.

Amino Acid Sequence↗