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Biomedical subjects

N Kondo

Publications and source records attributed to N Kondo.

At least 199 records · Page 11Linked to original sources
PubMed1998

Reduced interferon gamma production by antigen-stimulated cord blood mononuclear cells is a risk factor of allergic disorders--6-year follow-up study.

BACKGROUND: It is not sufficient to predict 'high allergic risk newborns' on the basis of increased IgE concentrations of cord blood alone, because a raised cord blood IgE concentration is specific but not sensitive in the prediction of the development of allergic disorders. Warner et al. have reported that interferon gamma (IFN-gamma) production by allergen-triggered cord blood cells is a predictor of atopic eczema, based on the 1-year follow-up study. OBJECTIVE: We examined whether IFN-gamma production by antigen-stimulated cord blood mononuclear cells (CBMCs) is a risk factor of allergic disorders, based on the 6-year follow-up study. METHODS: The relationships among cord blood IgE concentrations, IFN-gamma and interleukin-2 (IL-2) productions by antigen-stimulated CBMCs, and the development of allergic disorders in 21 infants for 6 years were investigated. RESULTS: Atopic dermatitis, atopic dermatitis and allergic rhinitis, or atopic dermatitis and bronchial asthma developed in seven of 21 subjects. The maximal IFN-gamma concentration in culture supernatants of ovalbumin (OA) or bovine serum albumin (BSA) stimulated CBMCs in infants who developed allergic disorders was significantly lower (P < 0.01) than that in infants who did not develop any allergic disorders. In contrast, the maximal IL-2 concentration in culture supernatants of OA- or BSA-stimulated CBMCs in infants who developed allergic disorders was not lower than in infants who did not develop any allergic disorders. Moreover, the IFN-gamma concentrations were negatively correlated with cord blood IgE concentrations. CONCLUSION: Reduced IFN-gamma production by antigen-stimulated CBMCs is a risk factor of allergic disorders.

Antigens↗
PubMed1998

Expression of Pax5 gene in human haematopoietic cells and tissues: comparison with immunodeficient donors.

In mice, Pax5 gene is indispensable for B cell development. Pax5-deficient mice fail to produce mature B cells owing to complete arrest of B cell development at a precursor stage. However, the lineage and stage of human Pax5 gene expression have remained elusive. In this investigation expression of the human Pax5 gene was studied. Pax5 gene expression was detected in B cell lines but not in myeloma cell lines. CD19 expression was correlated with Pax5 gene expression. Adult spleen and bone marrow and fetal spleen and liver showed strong Pax5 gene expression, as did the corresponding mouse tissues, as reported previously. In common variable immunodeficiency (CVID) peripheral blood lymphocytes (PBL) with a decreased number of B cells, no Pax5 gene expression was detected. Some CVID PBL stimulated with IL-2, IL-10 and anti-CD40 monoclonal antibody, expressed the Pax5 gene. Defect of Pax5 gene expression in CVID may be caused by regulatory T cell disorder.

Adolescent↗
PubMed1998

Mutation in PEX16 is causal in the peroxisome-deficient Zellweger syndrome of complementation group D.

Peroxisome-biogenesis disorders (PBDs), including Zellweger syndrome (ZS), are autosomal recessive diseases caused by a deficiency in peroxisome assembly as well as by a malfunction of peroxisomes, among which>10 genotypes have been identified. We have isolated a human PEX16 cDNA (HsPEX16) by performing an expressed-sequence-tag homology search on a human DNA database, by using yeast PEX16 from Yarrowia lipolytica and then screening the human liver cDNA library. This cDNA encodes a peroxisomal protein (a peroxin Pex16p) made up of 336 amino acids. Among 13 peroxisome-deficiency complementation groups (CGs), HsPEX16 expression morphologically and biochemically restored peroxisome biogenesis only in fibroblasts from a CG-D patient with ZS in Japan (the same group as CG-IX in the United States). Pex16p was localized to peroxisomes through expression study of epitope-tagged Pex16p. One patient (PBDD-01) possessed a homozygous, inactivating nonsense mutation, C-->T at position 526 in a codon (CGA) for 176Arg, that resulted in a termination codon (TGA). This implies that the C-terminal half is required for the biological function of Pex16p. PBDD-01-derived PEX16 cDNA was defective in peroxisome-restoring activity when expressed in the patient's fibroblasts. These results demonstrate that mutation in PEX16 is the genetic cause of CG-D PBDs.

Amino Acid Sequence↗
PubMed1998

Temperature-sensitive mutation in PEX1 moderates the phenotypes of peroxisome deficiency disorders.

The peroxisome biogenesis disorders (PBDs), including Zellweger syndrome (ZS), neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD), are autosomal recessive diseases caused by deficiency of peroxisome assembly as well as malfunction of peroxisomes, where >10 genotypes have been reported. ZS patients manifest the most severe clinical and biochemical abnormalities, while those with NALD and IRD show the least severity and the mildest features, respectively. PEX1 is the causative gene for PBDs of complementation group I (CG1), the highest incidence PBD, and encodes the peroxin, Pex1p, a member of the AAA ATPase family. In the present work, we found that peroxisomes were morphologically and biochemically formed at 30 but not 37 degrees C, in the fibroblasts from all CG1 IRD patients examined, whereas almost no peroxisomes were seen in ZS and NALD cells, even at 30 degrees C. A point missense mutation, G843D, was identified in the PEX1 allele of most CG1 IRD patients. The mutant PEX1, termed HsPEX1G843D, gave rise to the same temperature-sensitive phenotype on CG1 CHO cell mutants upon transfection. Collectively, these results demonstrate temperature-sensitive peroxisome assembly to be responsible for the mildness of the clinical features of PEX1 -defective IRD of CG1.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1998

Mutations in PEX10 is the cause of Zellweger peroxisome deficiency syndrome of complementation group B.

Peroxisome biogenesis disorders (PBD), such as Zellweger syndrome, are autosomal recessive diseases caused by a deficiency in peroxisome assembly as well as a malfunction of the peroxisomes, where at least 10 genotypes have been reported. We have isolated a human PEX10 cDNA (HsPEX10) by an expressed sequence tag homology search on a human DNA database using yeast PEX10 from Hansenula polymorpha, followed by screening of a human liver cDNA library. This cDNA encodes a peroxisomal protein (a peroxin Pex10p) comprising 326 amino acids, with two putative transmembrane segments and a C3HC4zinc finger RING motif. Both the N- and C-terminal regions of Pex10p are exposed to the cytosol, as assessed by an expression study of epitope-tagged Pex10p. HsPEX10 expression morphologically and biochemically restored peroxisome biogenesis in fibroblasts from Zellweger patients of complementation group B in Japan (complementation group VII in the USA). One patient (PBDB-01) possessed a homozygous, inactivating mutation, a 2 bp deletion immediately upstream of the RING motif, which resulted in a frameshift, altering 65 amino acids from the normal. This implies that the C-terminal part, including the RING finger, is required for biological function of Pex10p. PEX10 cDNA derived from patient PBDB-01 was defective in peroxisome-restoring activity when expressed in patient fibroblasts. These results demonstrate that mutation in PEX10 is the genetic cause of complementation group B PBD.

Amino Acid Sequence↗
PubMed1998

Increase in glutamine-non-amidated muropeptides in the peptidoglycan of vancomycin-resistant Staphylococcus aureus strain Mu50.

The peptidoglycan compositions of vancomycin-resistant Staphylococcus aureus (VRSA) strain Mu50 (MIC 8 mg/L) and hetero-VRSA strain Mu3 (MIC 3 mg/L) were compared in order to understand the mechanism of vancomycin resistance. As compared with Mu3, the cell wall of Mu50 had increased amounts of glutamine-non-amidated muropeptides and decreased cross-linking of peptidoglycan with a greatly decreased dimer/monomer ratio of muropeptides. In agreement with this observation, the peptidoglycan of Mu50 bound 1.4 times more vancomycin than that of Mu3. The increase in non-amidated muropeptides and the reduced cross-linking of the cell-wall peptidoglycan may contribute to the vancomycin resistance by increasing the consumption of vancomycin by the pre-existing cell wall of Mu50 and reducing the amount of vancomycin reaching the cytoplasmic membrane where the vital targets of the antibiotic are situated.

Amino Acids↗
PubMed1998

Dynamic organization of microtubules in guard cells of Vicia faba L. with diurnal cycle.

Stomatal movement is regulated by changes in the volume of guard cells, thought to be mainly controlled by an osmo-regulatory system. In the present study, we examined the additional involvement of cytoskeletal events in the regulation of stomatal movement. Microtubules (MTs) in guard cells of Vicia faba L., grown under sunlight, were observed during the day and night by immunofluorescence microscopy. Cortical MTs began to be organized in a radial array at dawn and increased in numbers in the morning following the increase in the stomatal aperture size. Thereafter, MTs became localized near the nucleus and began to be destroyed from the evening to midnight, following the decrease in stomatal aperture size. These diurnal changes in MT organization were observed even two days after transfer from natural light condition to total darkness, and were accompanied by corresponding changes in stomatal aperture. The increase in stomatal aperture size in the early morning was inhibited by 50 microM propyzamide, which destroys cortical MTs in guard cells, whereas the decrease in aperture size in the evening was suppressed by 10 microM taxol, which stabilizes cortical MTs. These results suggest that radially-organized cortical MTs of guard cells may control diurnal stomatal movement.

Benzamides↗
PubMed1998

Brother/sister siblings affected with Hunter disease: evidence for skewed X chromosome inactivation.

Hunter disease is an X-linked recessive disorder caused by a deficiency of iduronate-2-sulfatase activity. We describe a pair of brother/sister siblings with a typical feature of Hunter disease (mucopolysaccharidosis type II). They had normal karyotypes but a marked deficiency of iduronate-2-sulfatase activity in both lymphocytes and fibroblasts. The molecular analysis of the iduronate-2-sulfatase gene revealed the R468L(G1403-->T) substitution in their genes. Although the sister's genomic DNA was heterozygous for the mutant allele, the sister's cDNA was found to be homogeneous for this mutation. The mother was found to be a heterozygote. The analysis of X chromosome inactivation by comparison of the methylation patterns of the androgen-receptor (AR) gene which was isolated from the sister's fibroblasts and leucocytes revealed a skewed X chromosome inactivation of the paternal allele. These findings indicate that a skewed X chromosome inactivation of the paternal gene and a point mutation in the maternal gene were responsible for the lack of iduronate-2-sulfatase activity in the sister.

Binding Sites↗
PubMed1998

Magnetic resonance imaging of acute cerebellar ataxia: report of a case with gadolinium enhancement and review of the literature.

A 10-year-old girl exhibited severe cerebellar ataxia following acute enterocolitis, and was diagnosed as having acute cerebellar ataxia (ACA). MRI of the brain in the acute stage revealed moderate swelling of the cerebellum and abnormal signal intensity enhanced with gadolinium in the cerebellar hemisphere. This is the first report of an ACA case with positive gadolinium enhancement. Cases of ACA with MRI abnormalities are reviewed and the clinical entity of ACA is discussed in association with autoimmune encephalitis.

Acute Disease↗
PubMed1998

PEX12, the pathogenic gene of group III Zellweger syndrome: cDNA cloning by functional complementation on a CHO cell mutant, patient analysis, and characterization of PEX12p.

Rat PEX12 cDNA was isolated by functional complementation of peroxisome deficiency of a mutant CHO cell line, ZP109 (K. Okumoto, A. Bogaki, K. Tateishi, T. Tsukamoto, T. Osumi, N. Shimozawa, Y. Suzuki, T. Orii, and Y. Fujiki, Exp. Cell Res. 233:11-20, 1997), using a transient transfection assay and an ectopic, readily visible marker, green fluorescent protein. This cDNA encodes a 359-amino-acid membrane protein of peroxisomes with two transmembrane segments and a cysteine-rich zinc finger, the RING motif. A stable transformant of ZP109 with the PEX12 was morphologically and biochemically restored for peroxisome biogenesis. Pex12p was shown by expression of bona fide as well as epitope-tagged Pex12p to expose both N- and C-terminal regions to the cytosol. Fibroblasts derived from patients with the peroxisome deficiency Zellweger syndrome of complementation group III (CG-III) were also complemented for peroxisome biogenesis with PEX12. Two unrelated patients of this group manifesting peroxisome deficiency disorders possessed homozygous, inactivating PEX12 mutations: in one, Arg180Thr by one point mutation, and in the other, deletion of two nucleotides in codons for 291Asn and 292Ser, creating an apparently unchanged codon for Asn and a codon 292 for termination. These results indicate that the gene encoding peroxisome assembly factor Pex12p is a pathogenic gene of CG-III peroxisome deficiency. Moreover, truncation and site mutation studies, including patient PEX12 analysis, demonstrated that the cytoplasmically oriented N- and C-terminal parts of Pex12p are essential for biological function.

Amino Acid Sequence↗
PubMed1998

Continuous measurement of tympanic temperature with a new infrared method using an optical fiber.

The purpose of this study was to investigate the utility of an infrared tympanic thermometry by using an optical fiber for measuring tympanic temperature (Tty). In the head cooling and facial fanning tests during normothermia, right Tty measured by this method (infrared-Tty) and esophageal temperature (Tes) were not affected by decreased temple and forehead skin temperatures, suggesting that the infrared sensor in this system measured the infrared radiation from the tympanic membrane selectively. Eight male subjects took part in passive-heat-stress and progressive-exercise tests. No significant differences among infrared-Tty, the left Tty measured by thermistor (contact-Tty), and Tes were observed at rest or at the end of each experiment, and there was no significant difference in the increase in these core temperatures from rest to the end. Furthermore, there were no significant differences in the core temperature threshold at the onset of sweating and slope (the relationship of sweating rate vs. infrared-Tty and vs. contact-Tty). These results suggest that this method makes it possible to measure Tty accurately, continuously, and more safely.

Adult↗
PubMed1998

Control of circadian variation in skin blood flow response to heat stress.

Six male subjects had their lower legs immersed in water at 42 degrees C for 60 min at 4 different times of the day to study whether the skin blood flow response to passive heat stress shows circadian variation in the relationship between skin blood flow and local sweating rate. When skin blood flow was plotted against local sweating rate, three distinct phases were observed. Phase A, an increase in skin blood flow without sweating was maximal at night. But the slope of the regression line did not change over the day in Phase C. These findings suggest that there is circadian variation in the skin blood flow response before onset of sweating during passive heat stress. This variation might be related, in part, to the circadian rhythm in vasoconstrictor activity.

Adult↗
PubMed1998

[Magnetic resonance images of hematospermia].

BACKGROUND: We performed MRI (magnetic resonance imaging) in the pelvic region of 70 cases with hematospermia and conducted a study on the abnormal MRI findings to which hematospermia could be attributed. METHODS: We conducted a study on the morphological anomaly and change in the signal intensity in the prostate gland and of the seminal vesicle as well as on the presence or absence of dilation in the plexus venous surrounding the deferent duct or the prostate gland out of the abnormal MRI findings. As for the seminal vesicle, the patients whose seminal vesicle was seen in higher intensity than the prostate gland in T1 weighted images were diagnosed as having hemorrhagic focus and the patients whose seminal vesicle was seen in low intensity both in T1 and T2 weighted images were diagnosed as having fibrosis caused by chronic inflammation. RESULTS: Abnormal MRI findings were seen in 40 out of the 70 cases (57%). Anomaly in the prostate gland was indicated in 6 (9%) cases. Abnormality in the seminal vesicle was indicated in 30 cases (43%) including hemorrhage of seminal vesicle in 25 cases, chronic inflammation in five cases and cyst of seminal vesicle in one case. CONCLUSION: In conducting an examination of the patients with hematospermia, MRI is the noninvasive and reproducible method and it is possible to identify the hemorrhagic region. Therefore, MRI is thought to be useful to identify the causal organs of hematospermia.

Adult↗
PubMed1998

[A case of Poland's syndrome with giant bulla resected by using autologous fascia lata].

We reported a case of giant bulla with Poland's syndrome, only left pectoral major and minor muscles defect. A 58-year-old man was admitted to our hospital with shortness of breath on exertion. Computed tomographic scan revealed right giant bulla in emphysematous lung. The giant bulla was resected by linear stapler with autologous fascia lata. Though minor air leakage persisted for 5 postoperative days, the postoperative course was uneventful. It could be effective to reinforce staple line by using autologous fascia lata in emphysematous bulla without any infectious problem.

Fascia Lata↗
PubMed1998

[Two cases of two-year-old girls with hypoxic ischemic encephalopathy induced by convulsive status].

We reported two cases of two-year-old girls with hypoxic ischemic encephalopathy. Their symptom was coma induced by seizures with respective factors. CT image on subacute stage showed the decreased density of the whole brain except for the primary sensorimotor cortex and the occipital lobe. MRI and CT images on chronic stage revealed generalized atrophy with no abnormal density areas. 99mTc-ECD SPECT on chronic stage showed low perfusion in the whole brain except for the primary sensorimotor cortex and the occipital lobe, in which areas brain tissue is considered to be injured easily in hypoxic ischemic encephalopathy. The paradoxical distribution of abnormal cerebral perfusion areas in our cases was reported in this paper.

Brain↗