Biomedical subjects

T Ota

Publications and source records attributed to T Ota.

At least 19 recordsLinked to original sources

PubMed2000

The molecular characterization and tissue distribution of the human cysteinyl leukotriene CysLT(2) receptor.

Cysteinyl leukotrienes (CysLTs), slow-reacting substances of anaphylaxis, are lipid mediators known to possess potent proinflammatory action. Pharmacological studies using CysLTs indicate that at least two classes of G protein-coupled receptors (GPCRs), named CysLT(1) and CysLT(2), exist; the former is sensitive and the latter is resistant to the CysLT(1) antagonists currently used to treat asthma. Although the CysLT(1) receptor gene has been recently cloned, the molecular identity of the CysLT(2) receptor has remained elusive. Here we show that the pharmacological profile of an orphan GPCR (PSEC0146) is consistent with that of the CysLT(2) receptor. In human embryonic kidney 293 cells that express the PSEC0146 cDNA, leukotriene C(4) (LTC(4)) and leukotriene D(4) (LTD(4)) induce equal increases in intracellular calcium mobilization; these increases are not affected by CysLT(1) antagonists. Additionally, [(3)H]LTC(4) specifically binds to membranes from COS-1 cells transiently transfected with PSEC0146. Large amounts of the PSEC0146 mRNA are found in human heart, placenta, spleen, and peripheral blood leukocytes but not in the lung and the trachea. Pharmacological feature and expression studies will eventually lead to a better understanding of the classification of CysLT receptors, possibly leading to a reconsideration of the pathological and physiological role of CysLTs.

Animals↗

PubMed2000

[Hyperferritinemia and diseases].

Ferritin is the principal iron storage protein participating in iron metabolism. As serum ferritin levels often reflect the amount of storage iron in the body, physicians have measured serum ferritin in order to evaluate iron deficiency or overload. Although a rise in serum ferritin concentration occurs in iron overload, hyperferritinemia without it has been reported in some inflammatory diseases and malignancies. Some cytokines have been reported to be responsible for the elevation of ferritin production. Studies on serum isoferritin in adult Still's disease and other diseases, especially measurements of the proportion of glycosylated ferritin, have been widely accepted. Pathophysiological properties of the increased serum ferritin are not clear. However, we should be aware that the hyperferritinemia is not a result, but is profoundly participating in the disease process.

Biomarkers↗

PubMed2000

Statistical analysis of the 5' untranslated region of human mRNA using "Oligo-Capped" cDNA libraries.

We constructed 34 types of human "full-length enriched" and "5'-end enriched" cDNA libraries based on the "Oligo-Capping" method. We randomly picked and sequenced 10,000 clones from these libraries. BLAST analysis showed that about 50% of the cDNAs were identical to known genes. Among them, we selected 954 species of cDNA that should represent the entire sequence from the mRNA start sites. Compared with previously reported sequences, they were on average 45 bp longer in the 5'-end. Using these cDNA data, we statistically analyzed the sequence features of the 5'UTR. The average length of the 5'UTR was 125 bp, and there was little correlation with the corresponding mRNA length (correlation coefficient = 0.26). Of the 954 species of 5'UTR, 459 contained no in-frame terminator codon, which is against the common belief. Two hundred seventy-eight species contained at least one ATG codon upstream of the initiator ATG codon. We identified 569 upstream ATGs, in total, 63% of which adequately satisfied Kozak's criteria. These findings are contrary to the typical translation initiation model, which states that translation is initiated from the "first" ATG codon.

5' Untranslated Regions↗

PubMed2000

Molecular cloning of mouse thioredoxin reductases.

We screened clones for thioredoxin reductase genes with a degenerate PCR-based strategy and have isolated two novel cDNA clones from a mouse thymocyte cDNA library. These encode two distinct thioredoxin reductases (TrxR1 and TrxR2) with 499 and 527 amino acid (aa) residues and calculated molecular masses of 54.5 kDa and 56.8 kDa respectively. These proteins share 90% and 50% aa sequence identity with those of previously cloned human TrxR, containing the redox-active cysteines, FAD binding domain, and the selenocysteine (SeCys) insertion sequence, which is composed of a putative stem-loop sequence located in the 3'-untranslated region (UTR). TrxR2 showing less homology to human TrxR has a mitochondrial translocation signal and a mitochondrial prepeptide protease cleavage site in the N-terminal domain. Transient expression experiments of each gene as fusion proteins with Xpress-tagged protein in NIH 3T3 cells indicated that TrxR1 was localized in the nucleus and cytoplasm and TrxR2 in the mitochondria. Furthermore, we mapped the TrxR1 gene to chromosome 10 (placed 1.71 cR from D10Mit42, lod>3.0) and the TrxR2 gene to chromosome 16 (placed 22.56 cR from D16Mit34, lod>3.0). Thus, the mouse has at least two distinct nuclear genes for TrxR that have different translocation sites in the cell.

3T3 Cells↗

PubMed2000

Evolution of vertebrate immunoglobulin variable gene segments.

Evolution of Ig V gene segments are generally characterized by (a) evolution by "the birth and death process" and (b) diversifying selection. However, the detailed evolutionary pattern of V gene segments varies among species due to the fact that the humoral immune system itself has changed during vertebrate evolution. The change in somatic diversification system coupled with the change in lymphocyte development has imposed a significant impact on the evolution of Ig genes. In order to understand the evolution of immunological genes it is important to view it in the context of the evolution of the entire immune system itself.

Animals↗

PubMed2000

Development of chimeric molecules for recognition and targeting of antigen-specific B cells in pemphigus vulgaris.

Pemphigus vulgaris (PV) is an autoimmune blistering disease characterized by circulating pathogenic IgG antibodies against desmoglein 3 (Dsg3). The purpose of this study was to develop chimeric molecules for specific recognition and elimination of autoimmune B cells in PV. Mouse hybridoma cell lines producing anti-Dsg3 antibody (5H10, 12A2) were developed as an in vitro model system for targeting B cells. Dsg3-GFP, a baculoprotein containing the entire extracellular domain of Dsg3 fused with green fluorescence protein, recognized and targeted the hybridoma cells through their surface immunoglobulin receptors in an antigen-specific way. The epitopes of these monoclonal antibodies were mapped on the amino terminal EC1 and part of EC2, a region considered functionally important in cadherins. Chimeric toxin molecules containing the mapped region (Dsg3deltaN1) and modified Pseudomonas exotoxin were produced in bacteria (Dsg3deltaN1-PE40-KDEL, PE3 7-Dsg3deltaN1-KDEL) and tested in vitro on hybridoma cell lines. The chimeric toxins, but not Dsg3deltaN1 alone, showed dose-dependent toxic activity with a reduction in hybridoma cell number to 40-60% of toxin-negative control cultures, compared with little or no effect on anti-Dsg3-negative hybridoma cells. Furthermore, these toxins showed toxic effects on anti-Dsg3 IgG-producing B cells from Dsg3deltaN1-immunized mice, with a 60% reduction in cell number compared with Dsg3deltaN1 alone. Thus, specific recognition and targeting of antigen-specific B cells in PV was demonstrated; this strategy may hold promise as a future therapeutic option for PV and other autoimmune diseases.

ADP Ribose Transferases↗

PubMed2000

Transgenic rats carrying human c-Ha-ras proto-oncogenes are highly susceptible to N-methyl-N-nitrosourea mammary carcinogenesis.

A rat line carrying three copies of the human c-Ha-ras proto-oncogene, including its own promoter region, was established and designated Hras128. Expression of the transgene was detected in all organs examined from Hras128 rats by northern blot analysis. To examine its influence on susceptibility to N-methyl-N-nitrosourea (MNU)-induced mammary carcinogenesis, female rats were treated with 50 mg/kg MNU i.v. at 50 days of age. All 22 Hras128 transgenic rats rapidly developed multiple and large mammary carcinomas within as little as 8 weeks after MNU treatment (14.1 tumors/rat, average diameter 16.4 mm). In contrast, 24 non-transgenic littermates developed no or only small tumors (0.46 tumors/rat, average diameter 7.4 mm) within this period. PCR-restriction fragment length polymorphism (RFLP) analysis and direct sequencing for the transduced human c-Ha-ras proto-oncogene indicated that 38 out of 44 tumors (86.4%) contained cells with mutations at codon 12 in exon 1. However, the signal densities of the mutated bands observed in the RFLP analyses revealed the presence of mixed populations of mutated and non-mutated cells in the tumors, the latter being in the majority. PCR-single strand conformation polymorphism analysis detected no mutations in codons 12 or 61 of the endogenous rat c-Ha-ras gene of Hras128 rat tumors. The results thus indicate that rats carrying the transduced human c-Ha-ras proto-oncogene are highly susceptible to MNU-induced mammary carcinogenesis and that this is not primarily due to mutations of the transgene or endogenous c-Ha-ras gene.

Animals↗

PubMed2000

Spermatic cord metastases from gastric cancer with elevation of serum hCG-beta: a case report.

Spermatic cord metastases from gastric cancer are rare. We here document a case involving a gastric cancer that mimicked primary testicular tumor because of elevation of the serum human chorionic gonadotropin-beta (hCG-beta). The possibility of metastasis or recurrence of prior malignancies should therefore be considered when the clinical features described here are encountered, although elevation of hCG-beta is rare with tumors other than those in testis.

Biomarkers↗

PubMed2000

Chemopreventive effect of bovine lactoferrin on 4-nitroquinoline 1-oxide-induced tongue carcinogenesis in male F344 rats.

The modifying effects of dietary feeding of bovine lactoferrin (bLF) on tongue carcinogenesis initiated with 4-nitroquinoline 1-oxide (4-NQO) were investigated in male F344 rats. The activities of phase II detoxifying enzymes, glutathione S-transferase (GST) and quinone reductase (QR), polyamine content and ornithine decarboxylase (ODC) activity in the tongue were also examined for mechanistic analysis of possible modifying effects of bLF on carcinogenesis. At 7 weeks of age, all animals except those treated with bLF alone and untreated rats were given 20 ppm 4-NQO in drinking water for 8 weeks to induce tongue neoplasms. Starting 7 days before 4-NQO exposure, experimental groups were fed experimental diets containing bLF (0.2% and 2%) for 10 weeks ("initiation feeding"). Starting 1 week after the cessation of exposure to 4-NQO, the other experimental groups given 4-NQO and a basal diet were fed the experimental diets for 22 weeks ("postinitiation feeding"). At week 32, the incidence and multiplicity of tongue neoplasms in the "initiation feeding" groups of 0.2% and 2% bLF and the "post-initiation feeding" group of 0.2% bLF were lower than those of the 4-NQO alone group, but without statistical significance. However, "post-initiation feeding" of 2% bLF caused a significant reduction in the incidence (20% vs. 55%, P=0.02418) and multiplicity (0.25+/-0.54 vs. 0.70+/-0.71, P<0.05) of tongue squamous cell carcinoma (by 64%, P=0.02418). bLF treatment elevated liver and tongue GST activities and liver QR activity. The "post-initiation feeding" with 2% bLF significantly decreased QR activity, proliferating cell nulcear antigen-positive index and ODC activity in the tongue. In addition, feeding with bLF decreased tongue polyamine content. These results suggest that bLF, when given at the 2% dose level during the post-initiation phase, exerts chemopreventive action against tongue tumorigenesis through modification of cell proliferation activity and/or the activities of detoxifying enzymes.

4-Nitroquinoline-1-oxide↗

PubMed2000

A practical quick staining method using hydrochloric acid-fast metachromatic dye for megakaryocytes.

A specific stain using violet polymethine dye (VPM stain) for megakaryocytes was first developed by Kass (1995). We have modified this method for practical use in bone marrow specimens. The modified VPM stain labels megakaryocytes very well, while other marrow cells are poorly colorized. This staining procedure was more stable, and its color intensity was finer and clearer than the original. Using this stain, morphologic classification of megakaryocytes in bone marrow specimens from 11 normal and 8 myelodysplastic syndrome (MDS) patients was performed. Many megakaryocytes observed in MDS patients were juvenile compared with normal subjects according to their morphology. Blasts from acute megakaryoblastic leukemia (M7) and from a megakaryoblastic cell line (Mo7e) were also clearly stained with our method. This staining method is practical and very useful for rapid identification of megakaryocyte distribution and morphology.

Bone Marrow Examination↗

PubMed2000

Preparation of sensitive and specific oligonucleotide probes tailed using terminal transferase and dITP.

An oligonucleotide probe tailed with deoxyadenosine-5'-triphosphate or deoxythymine-5'-triphosphate is detectable with high sensitivity, but has a major drawback--the tail co-hybridizes specifically to complementary sequences. This can be a problem when screening cDNA clones that contain poly(dA) sequences. While it is possible to mask the cDNA tail with unlabeled poly(dA) or poly(A) oligonucleotides, false-positive clones are still produced because complete masking of extremely long (dA) tails is difficult. As a result, only cDNA clones that have extremely long poly(dA) sequences are often obtained by hybridization screening using tailed probes. In this report, we describe an oligonucleotide probe tailed with DIG-labeled nucleotide in combination with deoxyinosine-5'-triphosphate that was highly specific and sensitive to cDNAs. Terminal deoxynucleotidyl transferase efficiently adds dI nucleotides to the 3'-end. The dI of the tails did not pair with any nucleotides under stringent hybridization so that the specificity of hybridization assays remained high without affecting the sensitivity of the test. Colony hybridization experiments demonstrated that there were very few (1 of 80 tested) false positives using this technique. Its use may increase the accuracy of cDNA screening.

DNA Nucleotidylexotransferase↗

PubMed2000

[A patient with life-threatening giant hematoma caused by acquired inhibitor to factor VIII].

A 66-year-old non-hemophiliac man developed widely spreaded hematoma in soft tissues around neck. On the day of admission, he was nearly choked by the giant hematoma which markedly compressed trachea. Initially, to keep air way, an intratracheal intubation using a fiber scope was carried out. Coagulation studies revealed a marked prolongation of activated partial thromboplastin time (129 seconds, control: 24.9-33.2), a diminished activity of factor VIII (less than 1%) and a significant increase of factor VIII inhibitor titer (60 Bethesda unit/ml). We thereby diagnosed coagulopathy related to acquired inhibitor against factor VIII. The general combination therapy of intravenous infusion of both prothrombin complex concentrates and activated prothrombin complex concentrates, prednisolone and plasma exchange successfully stopped expansion of the giant hematoma. However, because the titer of factor VIII inhibitor remained increased and the activity of factor VIII was continued to reduced, cyclosporin was additionally administrated. As a result, the titer of factor VIII inhibitor was markedly improved, but the reduced activity of factor VIII was continued and re-bleeding around neck was observed. We thereby administered steroid pulse therapy, which resulted in complete remission of the disease activity and recovery of factor VIII activity.

Aged↗

PubMed2000

Different expression of positive and negative regulators of hepatocyte growth in growing and shrinking hepatic lobes after portal vein branch ligation in rats.

Portal vein branch embolization is often performed before hepatectomy to prevent postoperative liver failure. It is, however, still not clear how the embolized lobe shrinks and the non-embolized lobe proliferates in counterbalance. We investigated the expression of positive and negative regulators of hepatocyte growth to clarify the mechanisms of liver growth and atrophy in a rat portal vein ligation (PVL) model compared with partial hepatectomy (PH). A significant increase in DNA synthesis within the non-ligated lobe reached a peak at 36 h, a delay of 12 h as compared with PH, while no increase occurred in the ligated lobe. Expression of hepatocyte growth factor mRNA remarkably increased in the non-ligated growing lobe between 6 and 24 h, but was only slightly elevated in the ligated shrinking lobe. Contrarily, negative regulators of hepatocyte proliferation, such as TGF-beta1 and IL-1beta, were strongly expressed in the ligated shrinking lobe. Thus, the changes of portal venous flow and/or pressure caused by PVL may contribute to induction of different kinds of growth factors between the ischemic and non-ischemic lobes; these factors possibly regulate liver regeneration and atrophy after PVL.

Animals↗

PubMed2000

Transgenic rats carrying copies of the human c-Ha-ras proto-oncogene exhibit enhanced susceptibility to N-butyl-N-(4-hydroxybutyl)nitrosamine bladder carcinogenesis.

We have established a transgenic rat line carrying three copies of the human c-Ha-ras proto-oncogene with its own original promoter region, Jcl/SD-TgN(HrasGen)128Ncc (Hras128) rat. c-Ha-ras protein from expression of transduced and endogenous c-Ha-ras genes could be detected in the bladder epithelium of untreated transgenic rats. To examine their susceptibility to N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced urinary bladder carcinogenesis, male transgenic and wild-type littermates were treated with 0.05% BBN in their drinking water for 10 weeks and then killed at week 20. The numbers and volumes of total macroscopic bladder tumors including both transitional cell papillomas and carcinomas (TCC) per rat were much greater in Hras128 rats than in their wild-type counterparts. The numbers of carcinomas per rat were also significantly greater in Hras128 rats. Two cases of TCC exhibiting invasion of the bladder muscle layer, which is extremely rare in the wild-type animals under the experimental conditions used, were also observed in Hras128 rats. The GGC-->GAC mutations at codon 12 of the transgene were observed in only two TCC out of 21 bladder tumors (9.5%), assessed by RFLP analysis and direct sequencing. SSCP analysis did not show any endogenous c-Ha-ras gene mutations. One of 25 tumors (4.0%) in wild-type rats had an endogenous c-Ha-ras gene mutation at codon 12 that was detected (GGA-->GAA) by single-strand conformation polymorphism and direct sequencing. These results indicate that the Hras128 rat is highly susceptible to BBN carcinogenesis and may be utilized as a rat model for analysis of bladder tumor development. The mutation findings indicate that the enhanced tumor development is not primarily due to mutations occurring in the transgene.

Animals↗

PubMed2000

[A case of systemic lupus erythematosus with pulmonary hypertension].

A 15 year-old girl was admitted to the hospital because of fever, polyarthlargia, dry cough, dyspnea, butterfly rash and multiple oral aphthas. The diagnosis of systemic lupus erythematosus (SLE) was made based on renal disorders, pancytopenia, positive antinuclear antibody and positive for antibodies to double-stranded DNA. On admission, she developed progressive dyspnea with highly active SLE. The patient was complicated with both pulmonary hypertension (PH) and interstitial pneumonitis (IP), judging from increased pulmonary sound by an auscultation, interstitial shadows especially at bilateral lower lung and enlarged shadow of right atrium in a chest rentgenogram, ground glass pattern of bilateral middle to lower lung in a chest computed tomographic scan, increased pulmonary artery pressure, 53 mmHg, by an ultrasound cardiograph (UCG). Combination of methylprednisolone pulse therapy, cyclosporin A and plasma exchanges was effectively administered, which resulted in improvement of disease activity of SLE, IP and PH. However, two months later, although disease activity of SLE was completely reduced, recurrence of PH by UCG and multiple pulmonary embolism (PE) which was observed by a chest rentgenogram and a pulmonary blood flow scintigraphy was further complicated. Administration of cyclophosphamide pulse therapy and warfarin therapy improved both PE and PH. The patient had PH at the different clinical course of SLE; 1) PH maybe induced by severe IP at the active phase of SLE and 2) PH brought about from multiple PE at the inactive phase of SLE. Thus, the case is thought to be suggestive of elucidating the pathogenesis of PH of several systemic autoimmune diseases including SLE.

Adolescent↗

PubMed2000

Progressive loss of cortical acetylcholinesterase activity in association with cognitive decline in Alzheimer's disease: a positron emission tomography study.

We measured brain acetylcholinesterase activity in 30 patients with Alzheimer's disease (AD) and 14 age-matched controls by positron emission tomography (PET) and using a carbon 11-labeled acetylcholine analogue. Seven AD patients had repeat PET scans. The k3 values were calculated as an index of acetylcholinesterase activity in a three-compartment analysis using the metabolite corrected arterial input function. Twenty-eight of the 30 AD patients (14 each in the early and late onset subgroups) were retained in the study so as to equalize the range and average severity of cognitive impairment within the early and late onset subgroups. The k3 values were significantly reduced in the neocortex, hippocampus, and amygdala in the early onset AD patients, although the k3 values were significantly reduced only in the temporoparietal cortex and amygdala in the late onset AD patients. In the longitudinal study, all 7 repeat AD patients showed further reduction of cortical k3 values in the second PET scans, with a mean interval of 2 years, suggesting a progressive loss of the ascending cholinergic system from the nucleus basalis of Meynert in AD. In 37 AD patients, there was a highly significant correlation between the cortical k3 values and Mini-Mental State Examination scores, supporting the cholinergic hypothesis in AD.

Acetylcholinesterase↗

PubMed2000

Cerivastatin improves survival of mice with lipopolysaccharide-induced sepsis.

Development of severe sepsis is thought to result from the overproduction of cytokines, such as tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta), and nitric oxide. Recently, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, which are antihypercholesterolemic agents, have been reported to inhibit lipopolysaccharide (LPS)-induced production of cytokines and nitric oxide in vitro. In this study, we tested these effects in vivo. After LPS administration (15 mg/kg i.p.) to CD-1 mice, serum levels of both TNF-alpha and IL-1beta transiently increased, and peaked at 2 h. After the peak responses of TNF-alpha and IL-1beta, serum levels of nitrite and nitrate increased until at least 8 h. Pretreatment of the mice with cerivastatin (20 mg/kg i.p. 12 and 1 h before LPS injection) reduced serum levels of TNF-alpha and IL-1beta at 2 h, and nitrite and nitrate at 8 h, by 93, 60, and 44%, respectively. In this model of sepsis, cerivastatin significantly (P =.016) improved the rate of 7-day survival from 26.7 to 73.3%. These results cast new light on the usefulness of cerivastatin in preventing severe sepsis.

Animals↗

PubMed2000

[High-dose chemotherapy with autologous peripheral blood stem cell transplantation for treatment of non-Hodgkin's lymphoma].

Findings for 41 patients with non-Hodgkin's lymphoma (NHL) treated with high-dose chemotherapy (HDC) and/or autologous peripheral blood stem cell transplantation (PBSCT) are reported. Two of the 41 patients were treated with HDC alone without PBSCT. At transplant, 20 patients were in complete remission, while 19 had resistant NHL and had failed to achieve a complete remission (CR) after several courses of conventional chemotherapy. The conditioning regimens used were mainly ACE (cytarabine, cyclophosphamide, etoposide) and MEAC (MCNU, etoposide, cytarabine, cyclophosphamide). The treatment-related mortality rate was 4.9%. Two patients treated with MEAC died from intractable congestive heart failure. Nine of the 19 patients with resistant NHL achieved CR, and at a median follow-up of 26 months (range, 3 to 93 months) the estimated two-year disease-free survival rate for these patients was 44.4%. Four patients in CR at present were in partial remission before HDC and PBSCT. Fifteen of the 20 patients in CR before HDC were transplanted in first CR and 5 in 2nd CR. At a median follow-up of 49 months (range, 3 to 96 months), the estimated 3-year DFS for the group of all patients was 73.7%. Five relapses occurred between 5 and 35 months post-transplantation. In conclusion, HDC and PBSCT as induction therapy was only effective for patients with resistant NHL who responded to conventional chemotherapy, and may improve the survival of patients in CR as consolidation therapy.

Adolescent↗