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Biomedical subjects

K Hagiwara

Publications and source records attributed to K Hagiwara.

At least 37 records · Page 2Linked to original sources
PubMed2001

The suppression of ornithine decarboxylase expression and cell proliferation at the promotion stage of lung tumorigenesis in mice by alpha-tocopheryloxybutyric acid.

It is known that vitamin E inhibits tumor cell growth in vitro irrespective of its antioxidative effect. However, it is unclear whether the effect in vitro can be applied to the in vivo situation. In order to address this question, we estimated if alpha-tocopheryloxybutyric acid (TSE), a non-antioxidative vitamin E derivative in vivo, could inhibit cell proliferation during the tumorigenic process of lung in mice treated with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), the most potent carcinogen among tobacco-specific nitrosamines. TSE administration suppressed the labeling index of the proliferating cell nuclear antigen, a marker of cell proliferation at a promotion phase of NNK-induced lung tumorigenesis in mice. Similarly, TSE administration inhibited the elevation of ornithine decarboxylase (ODC) activity and its mRNA at the promotion phase. Of four transcription factors contributing to ODC induction, the change in the level of the c-Myc/Max-consensus oligonucleotide complex was only proportional to the change in ODC mRNA level. These results suggest that vitamin E can inhibit cell proliferation linked with ODC induction at the promotion phase of lung tumorigenesis irrespective of its antioxidative effect and that modulation of the transactivation of the c-Myc/Max complex for the ODC gene by TSE in part contributes to the suppression of ODC induction.

Animals↗
PubMed2001

Identification of genes upregulated in the inflamed colonic lesions of Crohn's disease.

To identify the molecular mechanism which primarily plays a role in the pathogenesis of Crohn's disease (CD) without prior hypothesis, differential display method was employed to detect differentially expressed genes between the inflamed and uninflamed colonic samples from one patient with CD. The mRNA levels of these genes were subsequently semi-quantitated in affected and unaffected tissues from six patients using reverse transcriptase polymerase chain reaction (RT-PCR). Six genes including long form FLICE inhibitory protein (FLIP(L)) were found to be consistently overexpressed in the inflamed colonic CD tissues. Immunohistochemical studies revealed that FLIP(L) expressing cells were lamina propria lymphocytes (LPLs). The present study suggested that overexpression of FLIP(L) in the LPLs may be involved in the pathogenesis of CD through defective activation-induced cell death. In addition, this study provided evidence for a possible role of several previously unsuspected genes in the pathogenesis of CD.

Adult↗
PubMed2001

Recurrent pneumonia with mild hypogammaglobulinemia diagnosed as X-linked agammaglobulinemia in adults.

BACKGROUND: X-linked agammaglobulinemia (XLA) is a humoral immunodeficiency caused by disruption of the Bruton's tyrosine kinase (BTK) gene. Typical XLA patients suffer recurrent and severe bacterial infections in childhood. METHODS: Flow cytometric analysis of the peripheral monocytes using the anti-BTK antibody was used to characterize a 27 year old male patient with mild hypogammaglobulinemia (IgG, 635 mg/dl; IgM, 11 mg/dl; IgA, <5 mg/dl). He had suffered from frequent pneumonia since age 25 but had no history of frequent infections in his childhood or in adolescence. Sequencing of the BTK cDNA obtained from an Epstein-Barr virus-transformed B lymphoblastoid cell line derived from the bone marrow of the patient was performed to confirm a genetic defect. RESULTS: Flow cytometric analysis of cytoplasmic BTK protein in peripheral monocytes indicated that the patient presents a rare case of adult-onset XLA and that his mother is an XLA carrier. Sequencing of the BTK gene revealed a deletion of AG in the codon for Glu605 (AGT), resulting in an aberrant stop codon that truncates the BTK protein in its kinase domain. CONCLUSIONS: This case suggests that some XLA cases may remain undiagnosed because they only show mild hypogammaglobulinemia and they lack repeated infections in childhood. Flow cytometric analysis is a powerful method to screen these patients.

Adult↗
PubMed2001

Physical and transcriptional map of a 311-kb segment of chromosome 18q21, a candidate lung tumor suppressor locus.

Here, we report the complete genomic sequence and the characterization of the 311-kb region of 18q21, a candidate tumor suppressor locus containing a region of homozygous deletion in a lung cancer cell line, Ma29. This region contained two known genes, SMAD4 and ME2 (mitochondrial malate oxydoreductase), and two novel genes, D29 (deleted in Ma29 HGMW-approved symbol ELAC1), encoding an evolutionarily conserved protein, and B29 (beside the Ma29 deletion HGMW-approved symbol C18orf3), with no significant homology to any known genes. The deleted DNA segment in Ma29, which was estimated to be 195 kb in size, included all the coding exons of ME2 and D29, but not the coding exons of SMAD4 and B29. The deleted region also included exon 0, a 5'-noncoding exon, of SMAD4, and the expression of SMAD4 was greatly reduced in Ma29 cells. Mutations of SMAD4 and D29 were detected in 1 of 45 lung cancer cell lines examined, while those of ME2 and B29 were not detected, indicating that these four genes are not major targets for 18q21 deletions. The physical and transcriptional map constructed in this study will provide basic information for the identification of a tumor suppressor gene(s) at 18q21 involved in lung carcinogenesis.

Antigens, CD↗
PubMed2001

Nucleotide sequence of genome segment 5 from Bombyx mori cypovirus 1.

The complete nucleotide sequences of the double-stranded RNA genome segments 5 (S5) from Bombyx mori cypovirus 1 (BmCPV-1) strains I and H were determined. The segments consisted of 2,852 nucleotides encoding putative proteins of 881 amino acids with molecular masses of approximately 101 kDa (p101). A homology search showed that p101 has high similarity (93%) to foot-and-mouth disease virus (FMDV) 2A protease (2Apro) at amino acid position 219 to 235. These findings suggest the possibility that p101 encoded by BmCPV-1 S5 might be cleaved into two non-structural proteins by post-translational autocleavage involving a 2Apro-like protease.

Amino Acid Sequence↗
PubMed2001

Upper bound of the expected training error of neural network regression for a Gaussian noise sequence.

In neural network regression problems, often referred to as additive noise models, NIC (Network Information Criterion) has been proposed as a general model selection criterion to determine the optimal network size with high generalization performance. Although NIC has been derived using asymptotic expansion, it has been pointed out that this technique cannot be applied under the assumption that a target function is in a family of assumed networks and the family is not minimal for representing the target true function, i.e. the overrealizable case, in which NIC reduces to the well-known AIC (Akaike Information Criterion) and others depending on a loss function. Because NIC is the unbiased estimator of generalization error based on training error, it is required to derive the expectations of errors for neural networks for such cases. This paper gives upper bounds of the expectations of training errors with respect to the distribution of training data, which we call the expected training error, for some types of networks under the squared error loss. In the overrealizable case, because the errors are determined by fitting properties of networks to noise components, including in data, the target set of data is taken to be a Gaussian noise sequence. For radial basis function networks and 3-layered neural networks with bell shaped activation function in the hidden layer, the expected training error is bounded above by sigma2* - 2nsigma2*logT/T, where sigma2* is the variance of noise, n is the number of basis functions or the number of hidden units and T is the number of data. Furthermore, for 3-layered neural networks with sigmoidal activation function in the hidden layer, we obtained the upper bound of sigma2* - O(log T/T) when n > 2. If the number of data is large enough, these bounds of the expected training error are smaller than sigma2* - N(n)sigma2*/T as evaluated in NIC, where N(n) is the number of all network parameters.

Analysis of Variance↗
PubMed2001

Concentrations of IL-6 in serum and whey from healthy and mastitic cows.

Inflammatory cytokines, such as interleukin (IL)-6, have been shown to reflect clinical signs in certain conditions in diseased animals. In this study, we quantified the IL-6 concentrations in the serum and milk whey from 94 dairy cows with acute clinical mastitis and 55 healthy lactating cows. The IL-6 concentrations in serum from mastitic cows were significantly higher on the first day of illness compared to those of normal cows. Higher concentrations of IL-6 were also detected in the whey from mastitic cows, whereas low concentrations of IL-6 were detected in both serum and whey samples from normal cows. IL-6 concentrations in the serum taken at the onset of illness from cows that later required euthanasia were significantly higher than those in samples from cows that later recovered. These results suggest that serum IL-6 concentrations may be of prognostic value in identifying cows with severe mastitis.

Animals↗
PubMed2001

Inhibition of expression of ornithine decarboxylase by c-myc antisense oligonucleotide at the promotion stage of lung tumorigenesis in mice.

Regulation of ornithine decarboxylase (ODC) expression at a promotion stage of lung carcinogenesis is a key clue to suppress the cancer. In this study, we investigated that the ODC induction at the promotion stage of lung carcinogenesis in mice could be inhibited through the suppression of the expression of c-myc, a transcription factor for ODC. The treatment with c-myc antisense oligonucleotide decreased the carcinogen-elevated level of pulmonary ODC protein at the promotion stage, but the sense oligonucleotide had no influence on the level. Overall, it is possible that the induction of ODC in the carcinogenic process of lung is regulated at its transcriptional level.

Animals↗
PubMed2001

Interferon-gamma and tumor necrosis factor-alpha levels in sera and whey of cattle with naturally occurring coliform mastitis.

Concentrations of interferon-gamma (lFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) were determined in serum and whey samples from cattle with naturally occurring coliform mastitis for two weeks after onset using bovine INF-gamma and TNF-alpha-specific ELISA. In serum and whey samples from healthy cows. IFN-gamma was almost undetectable and TNF-alpha was detected at low levels. At the onset of illness, INF-gamma in sera and whey and TNF-alpha in whey from the mastitic cows were significantly higher than their respective values in healthy cows. Concentrations of IFN-gamma and TNF-alpha in whey from mastitic cattle decreased significantly as the cows recovered.

Animals↗
PubMed2001

Effect of interleukin-1 receptor antagonist on concanavalin A response of peripheral blood mononuclear cells from newborn calves.

The coexistence of interleukin (IL)-1beta with IL-1 receptor antagonist (ra) in bovine colostrum and the possibility of simultaneous transfer of these cytokines to neonates via colostrum have been demonstrated. In the present study, we investigated the effect of IL-1ra on the mitogenic response of calf peripheral blood mononuclear cells (PBMC) stimulated by concanavalin A (ConA), which was mediated by IL-1. Pretreatment of PBMC with recombinant bovine (rb) IL-1ra alone significantly suppressed the proliferation of ConA-stimulated cells. However, in the presence of rbIL-1beta, the suppressive activity of rbIL-1ra was counteracted. These results suggest that coexistence of IL-1ra with IL-1 in colostrum may have no effect on the activation of the neonatal immune system by IL-1beta.

Animals↗
PubMed2001

[Perspectives on postgenome medicine: Gene therapy for lung cancer].

The gene therapy or the immunotherapy targeting specific molecule(s) have just introduced into the clinical field in Japan. The first gene therapy for the human lung cancer is underway; an adenoviral vector harboring wild type p53 gene is intratumorally injected. A cancer immunotherapy using the Cyclophilin B derived peptide is in the phase I clinical trial. As the next generation cancer therapies, a variety of strategies are planned and investigated at the laboratory level. They range from the usage of a new viral vector to the introduction of genes with specific biological functions into the cells. In this article, by reviewing the possible approach, an ideal combination of the future remedies is discussed.

Adenoviridae↗
PubMed2001

[Non-small-cell lung cancer (NSCLC) in an elderly patient--a case of squamous cell carcinoma successfully treated with chemotherapy using vinorelbine].

We report an elderly patient with squamous cell carcinoma who was successfully treated with chemotherapy using vinorelbine. A 76-year-old man was referred to our hospital for evaluation of a nodular shadow in the left lung. Chest CT scam showed a 3-cm tumor shadow in left S9 and a 1-cm small nodule in right S2. Transbronchial lung biopsy yielded a diagnosis of squamous cell carcinoma. The clinical stage was IV (cT2N2M1). The patient first underwent chemotherapy consisting of cisplatin (CDDP) 80 mg/m2 on day 1 and vinorelbine (VNB) 20 mg/m2 on days 1, 8, and 15, which generated tumor shrinkage of 48% as well as transient elevation of grade 1 in serum creatinine. The 2 cycles of chemotherapy using vinorelbine only (VNB 20 mg/m2 on days 1, 8, 15) produced a tumor reduction of 70% with grade-1 decrease of granulocytes. The low grade of toxicity enabled us to treat the patient in our outpatient office for the second cycle of the regimen. This case suggests that chemotherapy using low-dose vinorelbine might be suitable to treat elderly patients with NSCLC in outpatient settings.

Aged↗
PubMed2001

Mutational analysis of the Smad6 and Smad7 genes in hepatocellular carcinoma.

Resistance to the transforming growth factor-beta (TGF-beta) is a frequently found phenotype in human malignancies. The recent identification of Smad6 and Smad7, both anti-Smads which inhibit TGF-beta signaling, raises a possibility that constitutive activation of the anti-Smads by a somatic mutation may impair the TGF-beta signaling pathway. We tested this hypothesis by screening the entire coding sequences of these anti-Smads for mutations in 52 hepatocellular carcinoma (HCC) samples using polymerase chain reaction - single strand conformation polymorphism analysis. We detected no mutations, but found 3 single nucleotide polymorphisms (SNPs) in the Smad6 gene and 2 SNPs in the Smad7 gene. These results suggest that mutations of the Smad6 and Smad7 genes are not the main cause of the TGF-beta resistance in human HCC.

Alleles↗
PubMed2000

Detection of cytokines in bovine colostrum.

Colostrum contains factors that are protective for the neonate and may be a source of immunomodulary molecules that positively influence the immune status of the neonate. To confirm that colostrum contains a variety of cytokines with immunomodulatory properties, we established a bovine cytokine specific ELISA and five cytokines (IL-1 beta, IL-6, TNF-alpha, INF-gamma or IL-1 receptor antagonist, IL-1ra) in the whey samples from cows at different stages of lactation were monitored. The expression of cytokine mRNAs (IL-1 beta, IL-6, TNF-alpha and INF-gamma) in the colostral cells was detected by RT-PCR. The concentrations of cytokines in colostrum were significantly higher concentrations than those in the mature milk. A positive correlation was observed between the concentrations of IL-1ra and IL-1 beta in the colostrum samples. In conclusion, colostrum contains high levels of cytokines that could be produced and secreted in the mammary gland and that may have an immunomodulatory activity and influence neonatal immunity.

Animals↗
PubMed2000

Hemin pretreatment ameliorates aspects of the nephropathy induced by mercuric chloride in the rat.

Mercuric chloride (HgCl(2)) is known to be a nephrotoxicant. When HgCl(2) is administered into rats, acute renal failure (ARF) is induced. Heme oxygenase-1 (HO-1) is antioxidative enzyme and is known to play a protective role against the oxidative injury. To elucidate the cytoprotective role of HO-1 against the nephrotoxicant-induced ARF, we examined the effect of hemin, HO-1 inducer, on HgCl(2)-induced ARF. Subcutaneous administration of hemin (30 mg/kg body weight) into rats once a day for two successive days obviously induced HO-1 protein in the kidneys at 24 h after the last injection. Under this situation, when HgCl(2) (1 mg/kg body weight) was intraperitoneally injected into rats at 24 h after the last injection of hemin improved the serum creatinine (SCr) and blood urea nitrogen (BUN) levels, markers for renal injury, at 24 h after the HgCl(2) injection as compared with the control rats without hemin pretreatment (HgCl(2) treatment alone). This result was further confirmed by histopathological analysis. These findings strongly suggest that the preinduction of HO-1 ameliorates the subsequent HgCl(2)-induced acute renal injury.

Acute Kidney Injury↗
PubMed2000

Detection of Borna disease virus in a pregnant mare and her fetus.

A pregnant mare showing pyrexia, reduced appetite, ataxia and paresis was euthanized and examined for the presence of Borna disease virus (BDV). Her brain, showing multiple neuronal degeneration and necrosis with hemorrhage, and the histologically normal brain of the fetus were both positive for BDV RNA. The BDV nucleotide sequences were identical in the mare and fetus in the second open reading frame (ORF). This is the first report of the possible vertical transmission of BDV in a horse.

Animals↗