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Biomedical subjects

A Ishiguro

Publications and source records attributed to A Ishiguro.

At least 19 recordsLinked to original sources
PubMed2003

Transient elevation of interleukin-16 levels at the initial stage of meningitis in children.

IL-16 is an immunomodulatory cytokine that is characterized by chemotactic activity and stimulation of proinflammatory cytokine expression in monocytic cells. We studied IL-16 using ELISA in children with meningitis. When meningeal symptoms existed, IL-16 levels were high in the cerebrospinal fluid (CSF) of both bacterial (939 +/- 877 ng/l, n = 20) and aseptic (341 +/- 371 ng/l, n = 23) meningitis. The values in the CSF were significantly higher than those in non-meningitis controls (29 +/- 8 ng/l, n = 22, P < 0.0001). After meningeal symptoms disappeared, IL-16 levels in bacterial (191 +/- 149 ng/l, n = 10, P = 0.0042) and aseptic (159 +/- 188 ng/l, n = 13, P = 0.0118) meningitis were lower than those during the symptomatic stage. IL-16 levels were the highest before day 5 of the illness and then gradually fell. Significant correlations were found between IL-16 levels and both G-CSF levels (r = 0.783, n = 11, p = 0.0029) and IL-6 levels (r = 0.818, n = 12, P = 0.0005) in the CSF of bacterial and aseptic meningitis. IL-16 levels in all CSF samples from non-meningitis controls were lower than those in serum. In contrast, IL-16 levels in the CSF in six of 16 samples from bacterial meningitis and two of 18 samples from aseptic meningitis were higher than those in serum. Serum levels of IL-16 did not fluctuate throughout the course of meningitis. These data indicate that IL-16 levels rise transiently in CSF at the initial stage of meningitis. We speculate that IL-16 may promote inflammatory responses during meningitis in concert with other proinflammatory cytokines.

Child↗
PubMed2001

An increase in circulating mast cell colony-forming cells in asthma.

We compared a potential to generate mast cells among various sources of CD34(+) peripheral blood (PB) cells in the presence of stem cell factor (SCF) with or without thrombopoietin (TPO), using a serum-deprived liquid culture system. From the time course of relative numbers of tryptase-positive and chymase-positive cells in the cultured cells grown by CD34(+) PB cells of nonasthmatic healthy individuals treated with G-CSF, TPO appears to potentiate the SCF-dependent growth of mast cells without influencing the differentiation into mast cell lineage. CD34(+) PB cells from asthmatic patients in a stable condition generated significantly more mast cells under stimulation with SCF alone or SCF+TPO at 6 wk of culture than did steady-state CD34(+) PB cells of normal controls. Single-cell culture studies showed a substantial difference in the number of SCF-responsive or SCF+TPO-responsive mast cell progenitors in CD34(+) PB cells between the two groups. In the presence of TPO, CD34(+) PB cells from asthmatic children could respond to a suboptimal concentration of SCF to a greater extent, compared with the values obtained by those of normal controls. Six-week cultured mast cells of asthmatic subjects had maturation properties (intracellular histamine content and tryptase/chymase enzymatic activities) similar to those derived from mobilized CD34(+) PB cells of nonasthmatic subjects. An increase in a potential of circulating hemopoietic progenitors to differentiate into mast cell lineage may contribute to the recruitment of mast cells toward sites of asthmatic mucosal inflammation.

Adolescent↗
PubMed2001

H+-ATPase defect in Corynebacterium glutamicum abolishes glutamic acid production with enhancement of glucose consumption rate.

A mutant of Corynebacterim glutamicum ('Brevibacterium flayum') ATCC14067 with a reduced H+-ATPase activity, F172-8, was obtained as a spontaneous neomycin-resistant mutant. The ATPase activity of strain F172-8 was reduced to about 25% of that of the parental strain. Strain F172-8 was cultured in a glutamic-acid fermentation medium containing 100 g/l of glucose using ajar fermentor. It was found that glucose consumption per cell during the exponential phase was higher by 70% in the mutant than in the parent. The respiration rate per cell of the mutant also increased to twice as much as that of the parent. However, the growth rate of the mutant was lower than that of the parent. Under those conditions, the parent produced more than 40 g/l glutamic acid, while the mutant hardly produced any glutamic acid. Instead the mutant produced 24.6 g/l lactic acid as the main metabolite of glucose. Remarkably, the accumulation of pyruvate and pyruvate-family amino acids, i.e., alanine and valine, was detected in the mutant. On the other hand, the parent accumulated alpha-ketoglutaric acid and a glutamate-family amino acid, proline, as major by-products. It was concluded that the decrease in the H+-ATPase activity caused the above-mentioned metabolic changes in strain F172-8, because a revertant of strain F172-8, R2-1, with a H+-ATPase activity of 70% of that of strain ATCC14067, showed a fermentation profile similar to that of the parent. Sequence analyses of the atp operon genes of these strains identified one point mutation in the gamma subunit in strain F172-8.

Corynebacterium↗
PubMed2001

Antigenic components of Malassezia species for immunoglobulin E antibodies in sera of patients with atopic dermatitis.

Antigenic components of Malassezia furfur, M. globosa, M. restricta, M. slooffiae, and M. sympodialis were studied for immunoglobulin E antibodies in sera of patients with atopic dermatitis (AD). Antigenic components were extracted from Malassezia cells by treatment with beta-mercaptoethanol, referred to as 2-ME extract. CBB staining and lectin blots using Con A, LCA, PHA-E4, PNA or RCA120 showed that the 2-ME extracts contained several species-dependent components that differed quantitatively and qualitatively among the Malassezia species at the protein level. In the Western blot with the 2-ME extracts, of 54 sera of the patients with AD (54 patients), the patients' IgE antibodies most frequently recognized components showing molecular weights of 43-46 kDa for M. slooffiae, 12-22 kDa for M. sympodialis, 35-40 kDa for M. restricta, 45-50 kDa for M. globosa, and of 67-72 kDa for M. furfur, respectively. In the correlative study, in which the total band intensities generated for each extract in Western blot were compared among the Malassezia species, the intensity for M. globosa was well correlated with that for M. sympodialis (r=0.756). In the Western blot inhibition test, the 2-ME extract of M. globosa partially inhibited the reaction of the antigenic components of other Malassezia species with the patient's IgE antibodies. These results indicated that Malassezia species contained both species-specific and common antigenic components at the IgE antibody level.

Adolescent↗
PubMed2001

Early elevation of serum thrombopoietin levels and subsequent thrombocytosis in healthy preterm infants.

To verify pathophysiological mechanisms underlying thrombocytosis in low-birth-weight (LBW) preterm babies, we evaluated kinetic changes in platelet counts and thrombopoietic cytokines including thrombopoietin (TPO), interleukin 6 (IL-6) and IL-11 in 24 uncomplicated preterm infants. Platelet counts in cord blood (CB) (265 +/- 64 x 10(9)/l) were similar to adult levels, increased by d 14 (473 +/- 140 x 10(9)/l), and then remained fairly constant. Thrombocytosis (> 500 x 10(9)/l) was observed in 9/24 (38%) subjects. Mean TPO level in CB was 5.11 +/- 1.51 fmol/ml, peaked at d 2 (7.64 +/- 3.28 fmol/ml), decreased at d 5 (3.93 +/- 1.67 fmol/ml), and thereafter kept fairly constant during the remaining neonatal period. Compared with term infants, mean TPO levels of preterm infants in CB and at d 2 were significantly higher (P < 0.01). There was an inverse correlation between platelet counts and TPO levels (r = 0.45, P < 0.001, n = 88). Preterm neonates with thrombocytosis had significantly higher TPO values in CB than those without thrombocytosis (P < 0.05). There was no significant relationship between platelet counts and IL-6. IL-11 was not detectable. These results suggest that an early elevation of serum TPO levels is related to the subsequent thrombocytosis in LBW preterm infants.

Biomarkers↗
PubMed2001

Antioxidant activities of buckwheat hull extract toward various oxidative stress in vitro and in vivo.

We have undertaken four basic in vitro studies and an animal experiment to obtain information about the antioxidant activities of buckwheat hull extract (BWHE). In the in vitro studies, BWHE scavenged super oxide anion produced in the xanthine/xanthine oxidase system (IC50=11.4 microg phenolic compound/ml), and strongly inhibited autoxidation of linoleic acid (IC50=6.2 microg phenolic compound/ml). Low-density lipoprotein (LDL) oxidation induced by Cu2+ ion was also protected by BWHE. In the animal experiment, ddY mice were fed a standard diet supplemented with 0.75% BWHE for 14 d. In blood, liver and brain of the mice TBARS and fluorescent substance concentration were significantly decreased compared with those of non-treated mice. SOD like activity in serum also significantly rose by BWHE treatment. BWHE was shown to be effective for protecting biological systems against various oxidative stresses in vitro, and to have antioxidant activity in vivo.

Animals↗
PubMed2001

[Association of idiopathic thrombocytopenic purpura and type 1 diabetes mellitus in a patient with sarcoidosis].

Occurrence of autoimmune diseases with sarcoidosis is well known. However, a case in which more than one of these diseases coexist with sarcoidosis is rare. We present a young man with suspected sarcoidosis, complicated by idiopathic thrombocytopenic purpura (ITP) and type 1 A diabetes mellitus (DM). A 21-year-old man was admitted to our hospital because of thrombocytopenia, hyperglycemia, and bilateral hilar lymphadenopathy (BHL). Although a histological proof could not be obtained, the patient was considered to have sarcoidosis because 67-gallium scintigraphy disclosed "Lambda" and "Panda" signs which are highly specific for sarcoidosis. Type 1 A DM was also diagnosed as the patient had antiglutamic acid decarboxylase antibodies. The patient disclosed no hepatosplenomegaly or no lymphadenopathy and diagnosis of ITP was confirmed by bone marrow examination. High dose steroid was started as the thrombocytopenia progressed. The platelet number increased satisfactorily and shrinkage of BHL was also observed with the therapy.

Adult↗
PubMed2000

Stressful delivery influences circulating thrombopoietin (TPO) levels in newborns: possible role for cortisol in TPO-mpl binding.

The regulation mechanism of circulating thrombopoietin (TPO) level in human newborns remains unknown. In the present study, we examined whether the TPO concentrations in cord blood were influenced by the difference in the delivery method and the presence or absence of maternal/fetal complications. Cortisol levels were simultaneously measured to assess the adrenal response of fetuses. Both the TPO level and the cortisol level were substantially greater in the neonates delivered vaginally with and without the complications than in those delivered by cesarean section without the complications. The binding assay showed that the incubation of mpl(+)/BaF3 cells with cortisol gave rise to a significant decrease in the binding sites of TPO. These results suggest that the stress to the fetuses near the time of delivery affects the cord blood TPO levels, which may be mediated in part by the action of cortisol on the TPO-mpl binding system.

Binding Sites↗
PubMed2000

Isolation and characterization of a major antigenic component of Malassezia globosa to IgE antibodies in sera of patients with atopic dermatitis.

Three major components of Malassezia globosa were isolated from 2-ME extracts of this fungus by ion-exchange column chromatography and are referred to as Malg46a, Malg46b and Malg67, respectively. IgE antibodies to these components in the sera of patients with AD were detected by immunoblots. In Western blot, IgE antibodies to Malg46b were most frequently detected in the sera of AD patients. Dot blot with the Malg46b-containing fraction immunologically reacted with 69% of the sera of the patients, and with 83% of the sera of the patients who were positive for IgE antibodies to the 2-ME extract of M. globosa in the Western blot. The intensities generated for each dot correlated well with the total intensities generated for the 2-ME extract of M. globosa in the Western blot (r=0.763). In the lectin blot, Con A reacted with both Malg46a and Malg46b but not with Malg67. The polyclonal antibody to Malg46b reacted strongly only with the 2-ME extract of M. globosa and reacted slightly with M. restricta. In conclusion, a glycoprotein, Malg46b of M. globosa, is dominantly expressed in this fungus and is a possible major antigen for IgE antibodies in patients with AD.

Antigens, Fungal↗
PubMed2000

The Rpb6 subunit of fission yeast RNA polymerase II is a contact target of the transcription elongation factor TFIIS.

The Rpb6 subunit of RNA polymerase II is one of the five subunits common to three forms of eukaryotic RNA polymerase. Deletion and truncation analyses of the rpb6 gene in the fission yeast Schizosaccharomyces pombe indicated that Rpb6, consisting of 142 amino acid residues, is an essential protein for cell viability, and the essential region is located in the C-terminal half between residues 61 and 139. After random mutagenesis, a total of 14 temperature-sensitive mutants were isolated, each carrying a single (or double in three cases and triple in one) mutation. Four mutants each carrying a single mutation in the essential region were sensitive to 6-azauracil (6AU), which inhibits transcription elongation by depleting the intracellular pool of GTP and UTP. Both 6AU sensitivity and temperature-sensitive phenotypes of these rpb6 mutants were suppressed by overexpression of TFIIS, a transcription elongation factor. In agreement with the genetic studies, the mutant RNA polymerases containing the mutant Rpb6 subunits showed reduced affinity for TFIIS, as measured by a pull-down assay of TFIIS-RNA polymerase II complexes using a fusion form of TFIIS with glutathione S-transferase. Moreover, the direct interaction between TFIIS and RNA polymerase II was competed by the addition of Rpb6. Taken together, the results lead us to propose that Rpb6 plays a role in the interaction between RNA polymerase II and the transcription elongation factor TFIIS.

Amino Acid Sequence↗
PubMed1999

Carbamazepine-induced thrombocytopenia defined by a challenge test.

Carbamazepine (CBZ), a widely used anticonvulsant, occasionally causes serious hematologic disorders. A 12-year-old boy was admitted because of a diffuse petechial rash and profound thrombocytopenia (10 x 10(9) platelets/l), after having been treated for epilepsy with CBZ for 12 days. Seven days following withdrawal of CBZ and initiation of prednisolone therapy, the platelet count recovered. In a subsequent challenge test with CBZ, platelet counts again decreased, and the levels of platelet-associated IgG and serum interleukin-6 increased. No antibodies against platelet glycoprotein IIb/IIIa or Ib were detected in plasma. We believe that this is the first reported occasion when CBZ-induced thrombocytopenia has been defined by a rechallenge test.

Anticonvulsants↗
PubMed1999

Age-related changes in thrombopoietin in children: reference interval for serum thrombopoietin levels.

We studied thrombopoietin (TPO, Mpl ligand) values using a sensitive ELISA in 254 serum samples obtained from disease-free children and adult volunteers. TPO was detected in all samples, and its values ranged widely from 0.25 to 9.18 fmol/ml. When analysed by dividing the subjects into 11 age groups, the mean TPO levels from birth to 1 month of age were increased (3.73-5.92 fmol/ml). The highest values were found 2 d after birth; TPO levels then gradually decreased to adult levels (0.83 fmol/ml). The relationship between TPO values and platelet counts was not significant in all subjects (r = 0.27) or in children alone (r = 0.12). In children > 1 month of age a 95% reference interval for serum TPO values was determined from 0.58 to 3.27 fmol/ml. A significant correlation was found between TPO values in serum and plasma; serum TPO values = -0.257 + 4.039 x plasma TPO values (r = 0.951, P < 0.001, n = 22). This study is the first to report age-dependent changes in blood TPO levels throughout child development. Serum TPO values were significantly high up to 1 month of age and were correlated with plasma TPO levels.

Adolescent↗
PubMed1999

Correlation of lifting versus non-lifting and microscopic depth of invasion in early colorectal cancer.

BACKGROUND: The non-lifting sign is considered a contraindication to endoscopic resection. Our objective was to investigate whether lifting or nonlifting of a lesion is determined by the volume of normal submucosal tissue. METHODS: We measured the thickness of the submucosa and examined the relation between submucosal invasion and lesion elevation induced by submucosal injection in 60 patients with colorectal cancer with evidence of submucosal invasion. Extent of tumor elevation was classified into two groups: A, lifting; B, non-lifting. Submucosal invasion was classified as sm1, sm2, or sm3. The distance between the carcinoma and the line of resection and that between the carcinoma and the muscularis propria were measured. RESULTS: Of 31 sm1 lesions, 29 (93.5%) were group A. All 6 sm3 lesions were group B. All lesions in group A had a value for the distance between carcinoma and muscularis propria of more than 1000 microm. Group B lesions with sm3 invasion had distances of only 105 to 750 microm. CONCLUSION: Lesions classified as sm3 do not elevate in response to submucosal injection, and lesions that become elevated on injection can be resected endoscopically because they are sm1 or sm2 and have a thickness of normal submucosa of more than 1000 microm.

Adenomatous Polyps↗