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Biomedical subjects

H Kondo

Publications and source records attributed to H Kondo.

At least 307 records · Page 17Linked to original sources
PubMed1998

Identification of lysine-238 of Escherichia coli biotin carboxylase as an ATP-binding residue.

Escherichia coli biotin carboxylase was affinity labeled with adenosine diphosphopyridoxal to identify its ATP binding site. Lysyl endopeptidase digestion of the modified protein, followed by high performance liquid chromatography separation and amino acid sequencing allowed to identify lysine-238 to be the site of modification. Site-directed mutagenesis of this residue into alanine, arginine or glutamine resulted in mutants with much decreased activity. Lysine-238 seems to interact with the gamma-phosphate group of ATP but is not involved in catalysis.

Adenosine Diphosphate↗
PubMed1998

Immunohistochemical evidence for a macrophage scavenger receptor in Mato cells and reactive microglia of ischemia and Alzheimer's disease.

Macrophage scavenger receptors (MSR) are implicated in the development of atherosclerosis and amyloid b-protein deposition in Alzheimer's disease. However, histopathological studies of MSR expression in human tissues have been hampered by a lack of specific antibodies. Using MSR-deficient mice, we successfully raised a novel monoclonal antibody against human MSR together with high-titer antisera. These antibodies specifically recognized human tissue macrophages and human MSR protein purified from differentiated THP1 cells. In normal brain, MSR staining was mainly distributed to the perivascular cells, which correspond to Mato's fluorescent granular perithelial cells (Mato cells). In the lesions of ischemia and Alzheimer's disease, a subset of microglia stained positive for MSR. These novel antibodies are useful tools for analysis of MSR expression in human tissues.

Alzheimer Disease↗
PubMed1998

A novel class II phosphoinositide 3-kinase predominantly expressed in the liver and its enhanced expression during liver regeneration.

We report herein the cloning and characterization of a novel class II phosphoinositide 3-kinase, termed PI3K-IIgamma, from the cDNA library of regenerating rat liver. This cDNA encodes a protein of 1505 amino acids with a calculated molecular mass of 170,972 Da. The amino acid sequence of PI3K-IIgamma is highly similar to those of class II PI 3-kinases, including murine Cpk-m/p170 and human HsC2-PI3K. It contains a C2 domain at the C terminus but no recognizable protein motifs at its N terminus. PI3K-IIgamma displays a restricted substrate specificity for PtdIns and PtdIns 4-P, but not for PtdIns 4,5-P2. By epitope tag immunocytochemistry, the immunoreactivity for PI3K-IIgamma is localized in the juxtanuclear Golgi region at high levels and also in the plasma and nuclear membranes at low levels. By Northern blot analysis and in situ hybridization histochemistry, PI3K-IIgamma mRNA expression is confined to the liver throughout the development with much higher expression in adult liver than in fetal liver. In addition, its expression increases during liver regeneration after partial hepatectomy with maximal expression after the growth period, suggesting that PI3K-IIgamma may function mainly in highly differentiated hepatic cells.

Adult↗
PubMed1998

Toward the antibody-catalyzed chemiluminescence. Design and synthesis of hapten.

Hapten 4 was synthesized to generate catalytic antibodies triggering chemiluminescence by catalyzing the decomposition of the 1,2-dioxetane 3. The hapten 4 was so designed as to elicit a negatively charged functional group in the antibody combining site to catalyze the beta-elimination of the protecting group in 3 as well as to lock the protecting group into an energetically favorable anti-periplanar conformation.

Antibodies, Catalytic↗
PubMed1998

Prevention of severe hepatic injury by interferon-alpha in chronic active hepatitis lacking HBeAg (mutant strain) in a patient with malignant lymphoma.

Multidrug chemotherapy with concomitant interferon (IFN)-alpha was performed in a patient with chronic hepatitis lacking the hepatitis Be antigen and malignant lymphoma (ML). Levels of trans-aminases and DNA polymerase (DNA-P) values increased after the fifth course of chemotherapy. Therapy with IFN-alpha for 9 weeks induced a remission in liver disease and complete remission of ML was obtained with subsequent chemotherapy. It was possible to prevent severe liver damage by administering IFN immediately after the elevation of DNA-P. Early introduction of IFN may be effective in the prevention of fulminant hepatic failure from hepatitis from a precore mutant after chemotherapy.

Hepatic Encephalopathy↗
PubMed1998

Syntaxin 5 is a common component of the NSF- and p97-mediated reassembly pathways of Golgi cisternae from mitotic Golgi fragments in vitro.

A cell-free system that mimics the reassembly of Golgi stacks at the end of mitosis requires two ATPases, NSF and p97, to rebuild Golgi cisternae. Morphological studies now show that alpha-SNAP, a component of the NSF pathway, can inhibit the p97 pathway, whereas p47, a component of the p97 pathway, can inhibit the NSF pathway. Anti-syntaxin 5 antibodies and a soluble, recombinant syntaxin 5 inhibited both pathways, suggesting that this t-SNARE is a common component. Biochemical studies confirmed this, showing that p47 binds directly to syntaxin 5 and competes for binding with alpha-SNAP. p47 also mediates the binding of p97 to syntaxin 5 and so plays an analogous role to alpha-SNAP, which mediates the binding of NSF.

Adenosine Triphosphatases↗
PubMed1998

Localization of the mRNAs for two isoforms of Ca2+/calmodulin-dependent protein kinase kinases in the adult rat brain.

Ca2+/calmodulin-dependent protein kinase (CaM kinase) I and IV are thought to be activated by CaM kinase kinases (CaMKK). We examined the distribution of mRNAs for two isoforms (alpha and beta) of CaMKKs in the brain by in situ hybridization histochemistry. In the adult rat brain, CaMKK alpha mRNAs are widely distributed throughout the brain, whereas CaMKK beta mRNAs are restricted to some neuronal populations, particularly the cerebellar granule cells.

Animals↗
PubMed1998

Nuclear-recessive mutations of factors involved in mitochondrial translation are responsible for age-related respiration deficiency of human skin fibroblasts.

We addressed the question of whether both mitochondrial and cytoplasmic translation activities decreased simultaneously in human skin fibroblasts with the age of the donors and found that the age-related reduction was limited to mitochondrial translation. Then, to determine which genome, mitochondrial or nuclear, was responsible for this age-related, mitochondria-specific reduction, pure nuclear transfer was carried out from mitochondrial DNA (mtDNA)-less HeLa cells to four fibroblast lines, two from aged subjects, one from a fetus, and one from a patient with cardiomyopathy, and their nuclear hybrid clones were isolated. A normal fibroblast line from the fetus and a respiration-deficient fibroblast line from the patient were used as a positive and a negative control, respectively. Subsequently, the mitochondrial translation and respiration properties of the nuclear hybrid clones were compared. A negative control experiment showed that this procedure could be used to isolate even nuclear hybrids expressing overall mitochondrial respiration deficiency, whereas no respiration deficiencies were observed in any nuclear hybrids irrespective of whether their mtDNAs were exclusively derived from aged or fetal donors. These observations suggest that nuclear-recessive mutations of factors involved in mitochondrial translation but not mtDNA mutations are responsible for age-related respiration deficiency of human fibroblasts.

Aging↗
PubMed1998

Familial neuronal migration disorder: subcortical laminar heterotopia in a mother and pachygyria in the son.

We describe clinical manifestations and magnetic resonance imaging (MRI) findings in a man and his mother who were diagnosed as having a neuronal migration disorder. The son had severe psychomotor retardation and the mother had intractable seizures and mild psychomotor retardation. MRI demonstrated moderate pachygyria in the son and subcortical heterotopia in the mother. In both patients, the frontal parts of the brain were characteristically more affected than any other areas. A dominant pattern of inheritance in the family suggests a genetic role in the underlying cause of the migration disorder. The difference in severity between the two patients also suggests an X-linked dominant inheritance. Our family fits the condition of X-linked lissencephaly.

Adult↗
PubMed1998

Protective roles of two aluminum (Al)-induced genes, HSP150 and SED1 of Saccharomyces cerevisiae, in Al and oxidative stresses.

We isolated two yeast cDNA clones whose transcripts are induced by aluminum (Al) metal stress. Partial nucleotide sequencing showed that one is the HSP150 gene encoding a secreted heat shock protein, and the other corresponds to the SED1 gene encoding a putative membrane protein. To clarify the biological functions of these genes, we analyzed the sensitivity of gene-disrupted mutants to Al stress and to oxidative stresses. The Al tests indicated that the HSP150 protein served a basal protective role in Al stress, but SED1 did not; both of the genes had protective roles for oxidative stresses. The results for the HSP150 gene suggest that there is an overlap between Al ion stress, oxidative stress and heat shock stress in yeast.

Aluminum↗
PubMed1998

A new enzymatic assay for selectively measuring conjugated bilirubin concentration in serum with use of bilirubin oxidase.

A new enzymatic assay for selectively measuring conjugated bilirubin concentration in serum with use of bilirubin oxidase (BOD) has been developed. At pH 5.5 BOD can oxidize only conjugated bilirubin in the presence of reagents such as sodium fluoride and N-acetylcysteine which can decrease BOD reactivity to unconjugated bilirubin and bilirubin covalently bound to albumin (delta bilirubin). The resulting decrease in absorbance at 450 nm is linearly related to the concentration of conjugated bilirubin in serum. The BOD in this new assay was confirmed to oxidize conjugated bilirubin, and neither unconjugated nor delta bilirubin, based on both its reactivity to unconjugated bilirubin and HPLC results. This assay was found to give satisfactory results, such as in terms of the range of measurement, the reproducibility of the results, the lack of interference with coexisting substances in serum and the stability of the reagent solutions, in practical applications. The serum conjugated bilirubin concentrations determined using this assay correlate well with those determined by the HPLC analysis. This assay can be used for accurate monitoring of changes in the conjugated bilirubin concentration in patient sera. These findings suggest that the conjugated bilirubin assay is useful for fractional determination of bilirubin in icteric sera.

Bilirubin↗
PubMed1998

Enantioselective Total Syntheses of (-)-7betaH-Eudesmane-4alpha,11-diol and (+)-ent-7betaH-Eudesmane-4alpha,11-diol

The syntheses of (-)-7betaH-eudesmane-4alpha,11-diol (2) and (+)-ent-7betaH-eudesmane-4alpha,11-diol (ent-2) were carried out starting from (-)- and (+)-dihydrocarvones. As a result, the structure, including absolute configuration, of the naturally occurring eudesmane-4,11-diol isolated from Pluchea arguta was determined to be (+)-ent-7betaH-eudesmane-4alpha,11-diol (ent-2).

Journal Article↗
PubMed1998

Surgical resection of pulmonary metastases from gastric cancer.

BACKGROUND AND OBJECTIVES: There are no reports concerning surgical treatment on pulmonary metastases from gastric cancer. The aims of this study were to characterize patients with pulmonary metastasis from gastric cancer and to determine the efficacy of surgical therapy. METHODS: Between 1977 and 1993, 3,076 patients underwent curative resection for gastric cancer. Among them, four patients (0.1%) with pulmonary metastases from gastric cancer underwent pulmonary resection. RESULTS: All four patients had advanced gastric cancers involving regional lymph nodes far from the primary gastric lesion. The median tumor-free interval after the initial gastrectomy was 32.0 months (range: 19-48 months). All patients underwent a lobectomy for a solitary pulmonary lesion. Although transthoracic fine-needle aspiration cytology revealed adenocarcinoma in all cases, none of them were definitely diagnosed as metastasis from gastric cancer preoperatively. The diagnosis was obtained after pulmonary resection. All patients received postoperative chemotherapy or radiotherapy, or both. However, they all subsequently developed systematic metastases. The time interval to recurrence after pulmonary resection ranged from 6 to 36 months and they were all dead at a median follow-up of 24.3 months after the pulmonary resection. CONCLUSIONS: An aggressive surgical approach was not warranted in patients with isolated resectable pulmonary metastases from gastric cancer. However, the possibility of surgical treatment could not be eliminated because surgery is the only diagnostic method for a solitary pulmonary nodule when there is some doubt about the diagnosis of primary or secondary lung cancer in patients with gastric cancer.

Adenocarcinoma↗
PubMed1998

No deterioration in insulin sensitivity, but impairment of both pancreatic beta-cell function and glucose sensitivity, in Japanese women with former gestational diabetes mellitus.

To identify the primary pathogenic factors involved in the development of Type 2 diabetes mellitus (DM), we studied Japanese women with former gestational diabetes mellitus (GDM) who are at risk for the later development of Type 2 DM. We used the minimal model analysis derived from frequently sampled intravenous glucose tolerance test (FSIGT). The subjects consisted of eight non-obese women with a history of GDM and eight non-obese normal women as control subjects. The 75 g oral glucose tolerance test (75 g OGTT) performed within 6 months of delivery confirmed that all the subjects with former GDM had a normal glucose tolerance. Insulin sensitivity (SI) derived from the minimal model analysis was not different between the two groups. Glucose effectiveness at zero insulin (GEZI), reflecting tissue glucose sensitivity, was significantly lower in former GDM patients than in control subjects (1.18+/-0.34 vs 2.26+/-0.29 x 10(-2) min(-1), p < 0.05). The early phase insulin secretion found in FSIGT was markedly reduced to 56% of that observed in control subjects (1250+/-87.4 vs 2223+/-304.3 pmol l(-1) min, p < 0.01). Our results indicate that in former GDM patients, who are japanese and non-obese, impairment of the acute insulin response to glucose and a decrease in tissue glucose sensitivity rather than insulin sensitivity are the primary pathogenic factors involved.

Blood Glucose↗
PubMed1998

Percutaneous sensitization with allergens through barrier-disrupted skin elicits a Th2-dominant cytokine response.

We investigated whether percutaneous sensitization with different allergens through barrier-disrupted skin regulates the balance of Th1/Th2 cytokine expression. When mice were sensitized with the typical hapten picryl chloride (PiCl) by a single topical application to intact skin, there was an up-regulation in the lymph nodes (LN) of mRNA expression for the Th1 cytokines IL-2 or IFN-gamma, and for the Th2 cytokine IL-4. In contrast, sensitization with PiCl after barrier disruption of the skin down-regulated the expression of mRNA for IFN-gamma in a tape-stripping number-dependent manner without changing the expression of mRNA for IL-4. When mice were sensitized with house dust mite antigens (MA) by a single topical application to barrier-disrupted abdominal skin, there was a tape-stripping number-dependent up-regulation in the LN of mRNA expression for IL-4 but not for IL-2 or IFN-gamma. In the LN, mRNA for the IL-4-inducible immunoglobulins IgE and IgG1, but not for the IFN-gamma-inducible IgG2a, were up-regulated after sensitization with MA, while all three immunoglobulin mRNA were augmented after PiCl sensitization through intact skin. Antigenic elicitation by a topical application of PiCl in aural skin of mice sensitized through intact skin consistently increased the expression of mRNA for all three cytokines in the challenged skin, whereas elicitation in mice sensitized through barrier-disrupted skin decreased the expression of mRNA for IL-2 and IFN-gamma, but not for IL-4. Antigenic elicitation by subcutaneous injection of MA in aural skin consistently increased the expression of mRNA for IL-4, but not for IL-2 or IFN-gamma in the challenged skin. Infiltration of eosinophils in the dermis was more prominent following elicitation with MA in mice sensitized through barrier disruption than with PiCl in mice sensitized through intact skin. These findings suggest that the percutaneous entry of environmental allergens through barrier-disrupted skin is strongly associated with the induction of Th2-dominant immunological responses, as is seen in atopic dermatitis.

Allergens↗
PubMed1998

Discrepancy between tau immunoreactivity and argyrophilia by the Bodian method in neocortical neurons of corticobasal degeneration.

To clarify different features of cytoskeletal pathology in neocortical neurons between corticobasal degeneration (CBD) and Alzheimer's disease (AD), the relationship between neurofibrillary tangles (NFTs), which are defined as a fibrillary structure stained by the Bodian method, and tau-immunopositive neurons in layers II-III of the premotor cortex was assessed by sequential staining for tau immunohistochemistry followed by the Bodian method on the same section. In AD brains, tau-like immunoreactivity in neurons was uniformly colocalized with Bodian-positive NFTs. In CBD brains, however, tau-immunopositive neurons could be classified into three different types: (1) those not stained at all by the Bodian method (diffuse cytoplasmic type), which represented the majority of these immunopositive neurons, (2) some partly stained by the Bodian method (mixed type), and (3) a few for which argyrophilia demonstrated by the Bodian method was completely colocalized with immunoreactivity (NFT type). This discrepancy between tau-like immunoreactivity and Bodian method is characteristic of CBD and suggests that the tau molecule is less liable to form argyrophilic fibrils in neocortical neurons of CBD.

Aged↗