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Biomedical subjects

K Tanimoto

Publications and source records attributed to K Tanimoto.

At least 181 records · Page 10Linked to original sources

Normal levels of IgG subclass in childhood determined by a sensitive ELISA.

Normal values of all IgG subclasses were determined using a sensitive ELISA in children aged from newborn to 14 years. The upper and lower limits of normal values of all IgG subclasses were obtained in all the age groups using 29 umbilical cord blood samples from full-term newborns and 308 venous blood samples from normal infants and children. The trends in the levels of IgG1, IgG2 and IgG3 with age were almost similar to previous reports. IgG4 levels decreased gradually until reaching the lowest level at 7 to 12 months and increased gradually with age, reaching a plateau at 12 to 14 years of age. Thus, the lower limit of serum IgG4 levels was determined using our method.

Adolescent↗

Jaw cysts with orthokeratinization: analysis of 12 cases.

The clinico-pathologic, immunohistochemical and radiological features of 12 jaw cysts with a prominent orthokeratinized epithelial lining were studied and compared with those of typical odontogenic keratocysts and dentigerous cysts. They differed significantly from odontogenic keratocysts in terms of biologic behavior and histopathologic findings. Although immunohistochemical staining of the epithelial linings for cytokeratins, EMA, CEA and involucrin has not shed any light on the histogenesis of these lesions, staining patterns for these markers were significantly different from those of odontogenic keratocysts and non-keratinized dentigerous cysts. Radiologically, nine cases appeared as dentigerous cysts; two cases, one with sebaceous differentiation, as non-dentigerous unilocular cysts, and the remaining one was exceptional as it showed multiple epidermal cysts with prominent dermal appendages histologically. It is suggested that most of the orthokeratinized jaw cysts may belong to clinico-pathological entities different from odontogenic keratocysts with the majority representing dentigerous cysts with orthokeratinization. The possibility of the existence of rare central dermoid or epidermoid cysts is also to be considered.

Adolescent↗

Characterization of the traC determinant of the Enterococcus faecalis hemolysin-bacteriocin plasmid pAD1: binding of sex pheromone.

pAD1, a conjugative, 60-kb, hemolysin-bacteriocin plasmid in Enterococcus faecalis, encodes a mating response to a small peptide sex pheromone, cAD1, secreted by potential recipient bacteria. A gene, traC, encoding a 60.7-kDa protein with a typical amino terminal signal peptide, was identified within a region that appears to encode a product that binds to exogenous pheromone. A cloned segment of DNA containing traC resulted in specific binding of cells to synthetic cAD1. The putative traC product has strong similarity to a product of the E. faecalis plasmid pCF10 as well as oligopeptide binding proteins of Escherichia coli, Salmonella typhimurium, and Bacillus subtilis.

Amino Acid Sequence↗

Regulation of the pAD1-encoded sex pheromone response in Enterococcus faecalis: expression of the positive regulator TraE1.

pAD1 is a conjugative, 60-kb, hemolysin-bacteriocin plasmid in Enterococcus faecalis that encodes a mating response to a small peptide sex pheromone, cAD1, secreted by potential recipient bacteria. The response is regulated by a cluster of genes that includes a positive regulatory determinant, traE1, able to activate key structural genes involved in the conjugative process. A negative regulatory determinant, traA, affects the expression of traE1 and is sensitive to the pheromone signal. Between the two determinants is a gene, iad, which encodes a small peptide, iAD1, a competitive inhibitor of cAD1. The determinants (traE1-iad-traA) are oriented such that iad and traE1 are transcribed in the same direction, opposite that of traA. Transcription of iad and traA starts between these determinants and moves outward in each case. A recent report from our laboratory, dealing with transcriptional fusions in the traE1-iad region (L. T. Pontius and D. B. Clewell, J. Bacteriol. 174:3152-3160, 1992), indicated that traE1 expression may be dependent on transcriptional read-through of a terminator(s) between iad and traE1. The present report provides direct analyses of relevant RNA species before and during induction and shows that indeed transcriptional read-through from iad is important in the initial expression of traE1. However, the data show that once traE1 is activated, it can then be expressed independently, probably because of TraE1 activating its own promoter. This view is also supported by genetic complementation studies. In addition, DNA binding studies with TraA showed that the protein binds to the promoter of iad. Binding of TraA to the region between iad and traE1 could not be detected; however, the involvement of TraA in influencing transcription termination in this region is still not ruled out, since additional factors could be involved. A model for the regulation of the pheromone response is presented.

Amino Acid Sequence↗

[Detection of minus strand HCV RNA in liver tissue by reverse transcriptase polymerase chain reaction (RT-PCR)].

Hepatitis C virus RNA in serum and liver tissue was examined in seven patients with liver cirrhosis by reverse transcriptase polymerase chain reaction method using primers for 5'-non-coding region. Plus strand HCV RNA were detected in serum and liver tissues in five of five patients who had HCV antibodies (C100-3 antibody and P22 antibody) and were not detected in two of two patients who do not have HCV antibody. Minus strand HCV RNA was detected in liver tissue of five HCV antibody positive patients. These results suggest that HCV are present and replicate in liver tissue in patients with liver cirrhosis.

Base Sequence↗

A combination of upstream and proximal elements is required for efficient expression of the mouse renin promoter in cultured cells.

Renin, a key enzyme controlling blood pressure, is produced mainly in the kidney. To identify the transcriptional regulatory elements of the mouse Ren-1c gene, the promoter regions were fused to the CAT reporter gene and transfected into embryonic kidney-derived 293 cells and four extrarenal cell lines, HeLa, HepG2, HT1080 and NIH3T3 cells. Transient transfection assay showed that sequences from -365 to +16 of the renin gene could direct transcription of the CAT hybrid gene only in 293 cells. Deletion analysis identified two transcriptionally active regions; the renin upstream-promoter element (RU-1 element; position -224 to -138) and the renin proximal-promoter element (RP-2 element; position -75 to -47). Although the RU-1 element functioned as an activator, depending on its orientation, it failed to trans-activate the renin promoter when the RP-2 element was deleted. By contrast, the proximal element alone exhibited a weak trans-activator property. Gel shift assay identified RU-1 element-binding factors in both 293 and HeLa cells, whereas 293 cell-dominant factors were shown to bind only to RP-2 element. Therefore, both RU-1 and RP-2 elements were found to be necessary for efficient CAT expression from the renin promoter in 293 cells, suggesting that activation of the Ren-1c promoter requires combined action between cell type-dominant and ubiquitous nuclear factors.

Animals↗

Regulation of activin beta A mRNA level by cAMP.

We demonstrated the presence of five species of the activin beta A mRNA in human placenta and one major RNA associated with two minor RNAs of the activin in the fetal membrane. We investigated the effect of 8-bromo-cAMP (8-Br-cAMP) on accumulation of activin beta A subunit mRNA in human fibrosarcoma HT1080 cells. Although low levels of the activin mRNA were detectable in the untreated cells, the one main RNA species was predominantly accumulated by 8-Br-cAMP. We propose that generation of multiple activin mRNAs in the fetal membrane and cAMP-treated HT1080 cells is presumably due to a cell-specific alternative polyadenylation.

8-Bromo Cyclic Adenosine Monophosphate↗

Mother-to-infant transmission of hepatitis C virus.

Prospective studies of an infant of a mother infected with hepatitis C virus indicated that an HCV infection developed in the infant in early life. Perinatal transmission appeared to be the most likely explanation.

Female↗

Structure and expression of the mouse angiotensinogen gene.

Angiotensinogen is a precursor of the multifunctional octapeptide hormone, angiotensin II. We have isolated the overlapping clones containing angiotensinogen gene locus from C57BL/6 mouse genomic DNA library and analyzed them by restriction enzyme mapping. The gene exhibited a structural organization similar to those of the human, rat and balb/c mouse angiotensinogen genes. Using a genomic DNA fragment of the mouse angiotensinogen gene as a probe, we have investigated the tissue distribution of angiotensinogen messenger RNA (mRNA) in C57BL/6 mouse. The angiotensinogen mRNA was highest in the liver and detectable in such tissues as brain, kidney, submandibular gland, ovary and heart. However, it was undetectable in lung and spleen under the condition used. Optimal alignments of the 5'-flanking regions among the human, rat and mouse angiotensinogen genes disclosed several deletions in the mouse sequence. To assay the promoter activity, the 5'-flanking region of the mouse angiotensinogen gene was ligated to the bacterial chloramphenicol acetyltransferase (CAT) gene, then transfected into different cultured cells. The angiotensinogen gene sequences elicited preferential expression of CAT activity when introduced into HepG2 cells derived from liver and 293 cells from kidney but not in HeLa cells from uterus, suggesting the presence of a cell type-specific promoter within the sequences. These findings on the structure and expression of the mouse angiotensinogen gene should prove useful in studying the function and control of the angiotensin.

Angiotensinogen↗

Endothelial cell destruction by polymorphonuclear leukocytes incubated with sera from patients with systemic lupus erythematosus (SLE).

When normal polymorphonuclear leukocytes (PMN) were incubated with sera from patients with active systemic lupus erythematosus (SLE), a significantly increased cytotoxicity against human cultured vascular endothelial cells (EC), compared with normal control sera, was demonstrated by the standard 51Cr release method. The degree of this cytotoxicity was correlated with the immune complex level in each serum. The cytotoxicity did not correlate with the presence of anti-EC antibody. An absorption study with C1q-Sepharose 4B further suggested that the immune complexes are the factor which induce cytotoxicity. A gel fractionation study, however, indicated the heterogenity of the cytotoxic activity, and suggested the possible contribution of other substances including anti-EC, at least in some of the patients. This type of cytotoxicity may initiate the inflammatory process including vascular damage of the disease.

Adult↗

Lobenzarit disodium (CCA) inhibits the proliferation of human endothelial cells and the activity of DNA polymerase alpha.

N-(2)-Carboxyphenyl-4-chloroanthranilic acid disodium [Lobenzarit disodium (CCA)] is widely used for the treatment of patients with RA in Japan; however, the pharmacological mechanism of the compound is still unclear. In this report, the effect of CCA on the proliferation and DNA synthesis of endothelial cells was examined. CCA inhibited DNA synthesis in endothelial cells at a rather lower concentration than that in fibroblasts and HeLa cells. The DNA polymerase alpha activity was inhibited by CCA at a lower concentration than E. coli DNA polymerase I and avian myeloblastosis virus reverse transcriptase. Thus, CCA is a potent inhibitor of DNA polymerase alpha and this inhibitory effect could cause the inhibition of endothelial cell proliferation, which may be related to the therapeutic and pharmacological mechanisms of CCA.

Anti-Inflammatory Agents, Non-Steroidal↗

Preliminary criteria for classification of adult Still's disease.

We have attempted to design classification criteria for adult Still's disease by analyzing the data obtained through a multicenter survey of 90 Japanese patients with this disease and of 267 control patients. The proposed criteria consisted of fever, arthralgia, typical rash, and leukocytosis as major, and sore throat, lymphadenopathy and/or splenomegaly, liver dysfunction, and the absence of rheumatoid factor and antinuclear antibody as minor criteria. Requiring 5 or more criteria including 2 or more major criteria yielded 96.2% sensitivity and 92.1% specificity. However, an exclusion process will be needed for an accurate classification, since this disease is relatively rare.

Adolescent↗

[Overlapping syndrome].

Overlapping syndrome (OS) is usually used as the term of the combinations of three connective tissue diseases, i.e., systemic lupus erythematosus (SLE), progressive systemic sclerosis (PSS) and polymyositis (PM) or dermatomyositis (DM). OS is sometimes confused with mixed connective tissue disease (MCTD) since the definitions of the both diseases have not been established yet. Rheumatoid arthritis (RA) is a distinct disease and only exceptionally associated with the other CTD. These rare cases include destructive arthritis of SLE and PSS, multiple peripheral type of psoriatic arthritis, and arthritis associated with X-linked hypogammaglobulinemia and selective IgA deficiency. The conditions complicated with RA are not uncommon. They are osteoporosis, Sjogren's syndrome, amyloidosis and so on. There are some rare conditions or diseases which will be able to develop to RA. These peculiar cases include juvenile rheumatoid arthritis, adult onset Still's disease, polymyalgia rheumatica and palindromic rheumatism.

Amyloidosis↗