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Biomedical subjects

O Takeuchi

Publications and source records attributed to O Takeuchi.

At least 55 records · Page 3Linked to original sources
PubMed1999

Differential roles of TLR2 and TLR4 in recognition of gram-negative and gram-positive bacterial cell wall components.

Toll-like receptor (TLR) 2 and TLR4 are implicated in the recognition of various bacterial cell wall components, such as lipopolysaccharide (LPS). To investigate in vivo roles of TLR2, we generated TLR2-deficient mice. In contrast to LPS unresponsiveness in TLR4-deficient mice, TLR2-deficient mice responded to LPS to the same extent as wild-type mice. TLR2-deficient macrophages were hyporesponsive to several Gram-positive bacterial cell walls as well as Staphylococcus aureus peptidoglycan. TLR4-deficient macrophages lacked the response to Gram-positive lipoteichoic acids. These results demonstrate that TLR2 and TLR4 recognize different bacterial cell wall components in vivo and TLR2 plays a major role in Gram-positive bacterial recognition.

Animals↗
PubMed1999

Clinical assessment of positron emission tomography for the diagnosis of local recurrence in colorectal cancer.

BACKGROUND: The clinical value of positron emission tomography (PET) for the diagnosis of local pelvic recurrence of colorectal cancer was evaluated. METHODS: Computed tomography (CT) and magnetic resonance imaging (MRI) of the pelvis were performed at regular intervals in 23 patients who had undergone resection for colorectal cancer. The 23 patients had a total of 25 lesions. PET images of the 25 lesions and of six primary lesions in patients with rectal cancer were obtained. A differential absorption ratio (DAR) was calculated in order to examine the accumulation of [18F]2-fluoro-2-deoxy-D-glucose (18FDG) on PET images. Histological diagnoses of the pelvic masses were obtained by CT-guided needle biopsy. RESULTS: On CT or MRI, a pelvic mass with a spicular shape (n = 1) was non-recurrent, whereas a nodular or lumpy shape indicated a locally recurrent lesion (n = 10). Masses with a nodulospicular shape (n = 12) did not correlate with the histological features. On PET, 15 of 16 histologically proven local recurrences were imaged positively. By setting a DAR of 2.8 as a cut-off value, local recurrences could be diagnosed with 100 per cent accuracy. CONCLUSION: PET is a clinically useful tool for the detection of local recurrence of colorectal cancer, particularly for distinguishing between recurrence and granulation tissues in the pelvic cavity.

Adult↗
PubMed1999

[Efficacy of immunized milk for preventing viral infection].

This paper investigated the efficacy of passive protection provided by milk (immunized milk) against enterovirus infection in mice experimentally infected with enterovirus. Milk with a high antibody titer against six enterovirus serotypes was prepared from hyperimmunized goat. In vivo and in vitro experiments were performed and the results showed that immunized milk has an antiviral activity against enterovirus infection. Further observation was performed using Coxsackie B 3 virus (CVB 3). When immunized milk was orally applied to mice prior to oral inoculation with CVB 3, preventive effects against viral infection such as reduction of histopathological changes in the heart and reduced detection of the virus genome in the organs were seen. The antiviral effect was also indicated by the increase of CD4+T cells proportion in the i-IEL. The proportion of virus specific CD4+T cells was increased in mice treated with immunized milk, whereas no such increase was detected in control mice. These results suggest that oral application of immunized milk is not only capable of preventing viral infection but also induces specific immunological responses. These phenomena may play an important role in host defense mechanisms.

Animals↗
PubMed1999

Electron microscopic peritubular capillary lesions: a new criterion for chronic rejection.

Typical chronic rejection showing prominent glomerular and/or arterial lesions is less common in renal allograft patients treated with cyclosporin A (CsA). We investigated the value of peritubular capillary lesions as a criterion for chronic rejection in the CsA era. A total of 129 renal graft biopsies, taken from recipients showing graft dysfunction after more than 2 months post-operatively, were examined by electron microscopy, and peritubular capillary lesions were studied, especially multi-layered basement membrane lesions (MLPTC). Eighty-two biopsy specimens taken from non-transplantation patients were also studied as a control. Five biopsies (6%) showed mild and atypical MLPTC in the control group. Of the 129 allograft biopsies, MLPTC was seen in 55 (42.6%). The prevalence showed no significant relationship to the interval from operation to biopsy. MLPTC was either typical (n = 10) or incomplete (n = 45). Concomitant membrane disruption, edema and lymphocyte infiltration of the subendothelial space, reflecting acute cellular rejection, were occasionally noted in both groups. Incomplete MLPTC often developed within 1 yr after surgery, in association with acute rejection. It was found in 26-50% of biopsies at any time up to 5 yr post-operatively. The incidence of typical MLPTC was 5.7-12.8% over 1 yr post-operatively. These findings suggest that the development of chronic rejection is closely related to relapsing acute tubulo-interstitial allograft rejection which is often clinically silent. We concluded that MLPTC is useful as a specific criterion for chronic rejection.

Basement Membrane↗
PubMed1999

A case of IgA nephropathy after ABO-incompatible living kidney transplantation.

A 39-yr-old Japanese man underwent living related kidney transplantation. Because the graft was ABO-incompatible, he was treated with double filtration plasmapheresis before transplantation and his immunosuppressive therapy was stronger than usual. However, immunoglobulin A nephropathy, accompanied by cellular crescents and necrotizing lesions, developed after 18 months. To our knowledge, the association of IgA nephropathy with ABO-incompatible kidney transplantation has not been reported previously.

ABO Blood-Group System↗
PubMed1997

Effect of hyperoxia on adhesion molecule expression in human endothelial cells and neutrophils.

To investigate the pathogenesis of pulmonary oxygen toxicity, we examined the effect of hyperoxia on adhesion molecule expression in cultured human pulmonary artery endothelial cells (HPAEC) and human umbilical vein endothelial cells (HUVEC). Endothelial cell monolayers were exposed to either hyperoxic (90% O(2)-5% CO(2)) or normoxic (21% O(2)-5% CO(2)) conditions for various periods. The level of intercellular adhesion molecule (ICAM)-1 expression had increased in hyperoxia-exposed HPAEC and HUVEC at 48 h (194 +/- 38 and 233 +/- 56%, respectively; P < 0.001) and at 72 h (200 +/- 43 and 223 +/- 52%, respectively; P < 0.001) compared with normoxic conditions. These hyperoxia-induced ICAM-1 expressions were dose dependently attenuated by a protein kinase C inhibitor (H-7). In contrast, the levels of P-selectin and E-selectin expression in HPAEC and HUVEC were unchanged. The levels of ICAM-1 mRNA and the numbers of adherent neutrophils were increased in HPAEC and HUVEC at 48 and 72 h of hyperoxia. On the other hand, hyperoxia caused neutrophil H(2)O(2) production without affecting the level of CD11/CD18 expression. These results suggest that increased ICAM-1 expression in endothelial cells plays an important role in neutrophil accumulation during hyperoxia.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1995

[Comparative studies and application of a simple method of extraction of RNA from hepatitis C virus].

Conventional RNA extraction methods, such as SDS/phenol and AGPC methods involve time consuming and complicated manipulation procedures, which could be a cause of contamination. In this study, we compared the conventional methods with a method using a newly developed reagent, "SepaGene-RV" to extract RNA. The results obtained by the new method were the same as those obtained by the conventional methods in the comparative experiments with the sera of patients infected with HCV and detection limit tests using recombinant HCV genome. The sensitivity to detect HCV-RNA with SepaGene-RV was equivalent to that of conventionally used methods to extract RNA, and the manipulation procedure was simpler and it was less time consuming. In addition, we could detect plus-stranded and minus-stranded HCV-RNA by polymerase chain reaction assay (PCR) from liver tissue obtained from liver biopsy and peripheral blood mononuclear cells (PBMC). We confirmed that HCV infects not only liver tissue but also PBMC where replication occurs.

Genome, Viral↗
PubMed1994

Pro-carboxypeptidase R cleaves bradykinin following activation.

Arginine carboxypeptidase (CPR) is a labile enzyme present in human serum which is unrelated to carboxypeptidase N. In this study we demonstrate that CPR exists in a precursor form in plasma and can be converted to the active form by trypsin and presumable trypsin-like enzymes. The trypsin-generated active form can not only cleave a small synthetic substrate, hippuryl-L-arginine, but can remove terminal arginine from bradykinin.

Bradykinin↗
PubMed1993

Common structural and expressional properties of vertebrate caldesmon genes.

We have determined the genomic structure of chicken caldesmon (CaD) gene. The gene, 100-150 kilobases long, is composed of 17 exons. Exons 1a-1, 1a-2, and 1a-3 encode the 5'-terminal sequence specific to the mRNAs for CaDs expressed in gizzard. Exon 1b encodes the 5'-terminal sequence of the brain l-CaD and locates downstream of exons 1a-1, 1a-2, and 1a-3. The genomic construction of the chicken CaD resembles with that of the human CaD. Exon 3 of chicken CaD gene possesses the unique structure similar to that of human CaD gene; the common domain in both h- and l-CaDs (amino acid residues 74-199 for h-CaD and residues 66-191 for l-CaD) and the central repeating domain specific to h-CaD (amino acid residues 200-419) are encoded in exons 3a and 3b, respectively. Of particular interest is that the two consensus 5'-splice sites are found in the borders between exons 3a and 3b, and exon 3b and intron. Therefore, the expressional regulation between h- and l-CaDs can be explained by selection of these 5'-splice sites. Alternative 3'-splice sites also exist at intron/exon junction of exon 14 and the difference in selection of the sites would induce the specific Ala-508 insertion in the brain l-CaD.

Alternative Splicing↗
PubMed1992

A retrospective study on delirium type.

The clinical features of delirium type were retrospectively studied to characterize a delirium type in consecutive 106 patients. The subjects suffered from 15 medical diseases and were grouped into hyperactive, hypoactive and mixed types according to their cardinal features. The incidence of delirium was the highest in 70-year-old subjects and there was a gender effect in all the subjects. A decade effect was present in the outcome, delirium type and delirium duration. The delirium type was associated with age at the delirium onset, outcome and underlying disease. The incidence of hypoactive type correlated with that of mixed and hyperactive types, and a high rate of full recovery in the hyperactive type and a high rate of death in the mixed type were noted. The increase in incidence of the mixed type and the decrease in incidence of the hyperactive type contributed to a poor outcome. Malignancy, hepatic, cerebrovascular and bone and joint diseases highly correlated with the occurrence of delirium.

Adult↗
PubMed1981

Establishment and characterization of a cell line (Br-NHF-1) derived from human mammary carcinoma.

A new human cell line, Br-NHF-1, was established from the pleural effusion of a patient with advanced mammary carcinoma. The cells survived 52 subcultivations during more than 33 months. The cells possess epithelial features, showing rosettes, acinar formation and domes in or among the compact colonies. The modal chromosome number is 51 with some marker chromosomes. Xenografted tumors retained a similar histology to the original tumor. No estrogen-binding protein was detectable in the culture, but there was a significant amount of basic fetoprotein. Production of casein in the cells was detected by immuno-fluorescence testing.

Animals↗