Biomedical subjects

Y Yoshitake

Publications and source records attributed to Y Yoshitake.

At least 37 records · Page 2Linked to original sources

PubMed1998

Determination of percent body fat by the newly developed sulfur hexafluoride dilution method and air displacement plethysmography.

The reliability and validity of two newly developed densitometric methods for determining the human body volume and percent body fat (%FAT), the sulfur hexafluoride dilution method (SHF) and air displacement plethysmography (ADP), were evaluated in comparison with the underwater weighing method (UWW). Seven healthy male volunteers (age 31 to 44, mean height 166.0 cm, weight 61.4 kg) participated in this study. The same-day test-retest coefficients of variation (CVs) for body volume and %FAT measurements were not significantly different among the three methods. SHF and UWW showed a strong correlation in terms of body volume and %FAT, with the correlation coefficients (r) being 0.9997 and 0.986, respectively. The correlation between ADP and UWW was slightly weaker (r = 0.9997 for body volume and 0.907 for %FAT). However, body volumes measured by SHF and ADP were significantly different from that by UWW when compared by mean values. Such differences were also found for %FAT measurements. The regression lines of body volume measured by SHF and ADP on that by UWW were almost equivalent to the line of identity. However, those of %FAT measured by SHF and ADP on that by UWW were significantly different from the line of identity. Because the reliability of SHF and ADP appeared to be high, further validation and improvement are required and worth doing.

Adult↗

PubMed1997

cDNA cloning and chromosomal mapping of genes encoding novel protein kinases termed PKU-alpha and PKU-beta, which have nuclear localization signal.

We have cloned cDNAs for novel serine/threonine protein kinases (PK), termed PKU-alpha and PKU-beta, by screening a bacteriophage expression library for kinase activity. Sequence analysis of PKU-alpha and PKU-beta genes revealed that their open reading frames (ORF) were 2151 and 2361 nucleotides (nt) encoding polypeptides of 717 and 787 amino acid (aa) residues, respectively. The deduced aa sequences of PKU-alpha and PKU-beta contained typical serine/threonine PK domains at the C-terminal region and were 86% identical to each other, indicating that they belong to the same PK family. Northern analysis reveals that they are expressed in nearly all human tissues and in cultured cells. The genes for PKU-alpha and PKU-beta were mapped to chromosome 17q23 and 8p12-p22, respectively, by fluorescence in situ hybridization. The proteins encoded by both cDNAs contain a putative nuclear localization signal (NLS) in their N-terminal region. These signals are likely to function in nuclear localization. Glutathione S-transferase (GST)-fusions to regions of PKU-alpha and beta containing the NLS were efficiently localized to the nucleus. In addition, PKU-beta transiently expressed in COS-1 cells was predominantly nuclear. PKU-alpha and PKU-beta differ: a consensus sequence for a nt binding motif is present near the NLS of PKU-beta. These results suggest that PKU-alpha and beta may phosphorylate serine and/or threonine residues on similar proteins, but their activities are regulated through distinct interactions with a nuclear component.

Amino Acid Sequence↗

PubMed1997

Apical enrichment of human EGF precursor in Madin-Darby canine kidney cells involves preferential basolateral ectodomain cleavage sensitive to a metalloprotease inhibitor.

EGF precursor (proEGF) is a member of the family of membrane-anchored EGF-like growth factors that bind with high affinity to the epidermal growth factor receptor (EGFR). In contrast to human transforming growth factor-alpha precursor (proTGFalpha), which is sorted basolaterally in Madin-Darby canine kidney (MDCK) cells (Dempsey, P., and R. Coffey, 1994. J. Biol. Chem. 269:16878-16889), we now demonstrate that human proEGF overexpressed in MDCK cells is found predominantly at the apical membrane domain under steady-state conditions. Nascent proEGF (185 kD) is not sorted but is delivered equally to the apical and basolateral membranes, where it is proteolytically cleaved within its ectodomain to release a soluble 170-kD EGF form into the medium. Unlike the fate of TGFalpha in MDCK cells, the soluble 170-kD EGF species accumulates in the medium, does not interact with the EGFR, and is not processed to the mature 6-kD peptide. We show that the rate of ectodomain cleavage of 185-kD proEGF is fourfold greater at the basolateral surface than at the apical surface and is sensitive to a metalloprotease inhibitor, batimastat. Batimastat dramatically inhibited the release of soluble 170-kD EGF into the apical and basal medium by 7 and 60%, respectively, and caused a concordant increase in the expression of 185-kD proEGF at the apical and basolateral cell surfaces of 150 and 280%, respectively. We propose that preferential ectodomain cleavage at the basolateral surface contributes to apical domain localization of 185-kD proEGF in MDCK cells, and this provides a novel mechanism to achieve a polarized distribution of cell surface membrane proteins under steady-state conditions. In addition, differences in disposition of EGF and TGFalpha in polarized epithelial cells offer a new conceptual framework to consider the actions of these polypeptide growth factors.

Animals↗

PubMed1997

Requirement of fibroblast growth factor signaling for regeneration of epiphyseal morphology in rabbit full-thickness defects of articular cartilage.

The involvement of fibroblast growth factor-2 (FGF-2) during the repair process in rabbit full-thickness defects of articular cartilage was studied. Fibroblast growth factor-2 (50 pg/h) was administered for 2 weeks in a 5 mm defect of articular cartilage, which is large enough not to repair spontaneously. The administration of FGF-2 resulted in the regeneration of the articular cartilage and the subchondral bone within 8 weeks. In these defects, undifferentiated mesenchymal cells initiated chondrogenic differentiation coupled with replacement by subchondral bone, resulting in the resurfacing of the defects with hyaline cartilage and the recovery of subchondral bone up to the original bone-articular cartilage junction. In rabbits, full-thickness defects are capable of regenerating articular cartilage as long as the defect size is limited to < or = 3 mm in diameter. In the defects, strong immunoreactivity for FGF-2 was observed in the granulation tissue filling the defects in the early stage of repair, in association with the expression of FGF-2 mRNA shown by in situ hybridization. Once the undifferentiated mesenchymal cells had differentiated into chondrocytes, both the immunoreactivity and the in situ hybridization signal declined significantly. Upon the local administration of a monoclonal antibody against FGF-2 (bFM-1, 50 ng/h), the defects were filled with fibrous tissue and no resurfacing hyaline cartilage was formed. Compared to the non-treated defects, there were marked increases in FGF-2 immunoreactivity and the overexpression of FGF-2 mRNA in the reparative tissue in the bFM-1-treated defects. This rebound phenomenon indicates that the autocrine FGF-2 signaling is critically important for the regeneration of articular cartilage.

3T3 Cells↗

PubMed1997

Spontaneous polyploidization results in apoptosis in a Meth-A tumor cell line.

Cultured Meth-A cells always include a small fraction of large cells, which had a DNA content above 4c (polyploid cells). The process from the formation to the disintegration of polyploid Meth-A cells was measured by means of time-lapse videography. Polyploid Meth-A cells arose spontaneously from normal cells (polyploidization), then died by apoptosis. The fraction of polyploid cells gradually increased in seven day-exponential cultures with a low concentration of demecolcine, which is a specific inhibitor of cell division. The results revealed that the polyploid Meth-A cells are generated from normal cells by failing cell division and that they die by apoptosis.

Apoptosis↗

PubMed1996

A novel growth-promoting factor derived from fetal bovine cartilage, chondromodulin II. Purification and amino acid sequence.

During endochondral bone formation, cartilage cells show increased matrix synthesis and rapid proliferation. We found that cartilage matrix contains at least two types of heparin binding growth-promoting components. One, with a higher affinity to heparin, was identified as chondromodulin I (Hiraki, Y., Tanaka, H., Inoue, H. , Kondo, J., Kamizono, A., and Suzuki, F. (1991) Biochem. Biophys. Res. Commun. 175, 871-977). In this study, we isolated a novel growth-promoting component, chondromodulin II, which has a lower heparin affinity, from the dissociative extracts of fetal bovine epiphyseal cartilage. Chondromodulin II stimulated the proteoglycan synthesis in rabbit cultured growth plate chondrocytes, an expression of the differentiated phenotype of chondrocytes. It also stimulated DNA synthesis in chondrocytes in both the absence and the presence of fibroblast growth factor-2. The apparent molecular mass of chondromodulin II on SDS-polyacrylamide gel electrophoresis was 16 kDa. Its complete amino acid sequence was determined by overlapping sequences of the peptides released by endopeptidase digestion and CNBr cleavage. Chondromodulin II consists of 133 amino acids (calculated Mr = 14,548). The sequence was unique but homologous to the repeats 1 and 2 of the deduced amino acid sequence of the chicken mim-1 gene, which is specifically transactivated by the v-Myb oncogene product in promyelocytes. We also found a minor component with a higher heparin affinity, chondromodulin III, in cartilage extracts. Chondromodulin III stimulated DNA synthesis in chondrocytes in vitro, and its N-terminal sequence was identical with ribosomal protein L31 lacking the N-terminal three amino acids. These findings suggest that the growth and differentiation of chondrocytes are regulated by multiple components in the cartilage matrix.

Acetyltransferases↗

PubMed1996

Expression and localization of basic fibroblast growth factor (bFGF) in the repair process of rat liver injury.

BACKGROUND/AIMS: To clarify the expression and localization of basic fibroblast growth factor in the repair process of liver injury, acute liver injury was induced by administration of carbon tetrachloride, D-glactosamine hydrochloride, or dimethylnitrosamine to rats. METHODS: We measured basic fibroblast growth factor protein in the liver tissue by radioimmunoassay, evaluated the expression of basic fibroblast growth factor mRNA by the reverse transcriptase polymerase chain reaction, and identified basic fibroblast growth factor-positive cells by immunostaining. RESULTS: In the carbon tetrachloride injured liver, the basic fibroblast growth factor protein contents began to increase 2 days after administration when liver injury was most marked, and reached a peak after 4 days, decreasing thereafter. In the carbon tetrachloride-injured liver, basic fibroblast growth factor mRNA expression was observed from 12 h after administration, prior to an increase in the protein content. In the D-galactosamine hydrochloride-injured liver, basic fibroblast growth factor protein also increased. On the other hand, in the dimethylnitrosamine-injured liver, the basic fibroblast growth factor protein content decreased 2 days after administration when liver injury was marked, but increased after 7 days. In the regenerating liver after partial hepatectomy, the basic fibroblast growth factor protein content did not increase. Among cell fractions, the Ito cell fraction obtained from the carbon tetrachloride-injured liver after 4 days showed expression of basic fibroblast growth factor mRNA. In cells cultured for 24 h, this fraction was immunopositive for basic fibroblast growth factor. Ito cells in the liver tissue markedly increased in the carbon tetrachloride-injured liver and increased after 7 days in the dimethylnitrosamine-injured liver. CONCLUSIONS: This study confirmed basic fibroblast growth factor production in the liver tissue in the repair process of liver injury. Our results suggest that basic fibroblast growth factor is primarily produced in Ito cells, acts on sinusoidal wall cells including Ito cells by the autocrine and paracrine mechanisms, and promotes extracellular matrix production and vascularization, involving the repair process of liver injury.

Animals↗

PubMed1995

Structural organization and chromosomal assignment of the human prostacyclin receptor gene.

Prostacyclin receptor is a member of the prostanoid receptor family in the G protein-coupled receptor superfamily with seven transmembrane domains. We report here the isolation and structural organization of the human prostacyclin receptor gene. Southern blot analysis demonstrated a single copy of the human prostacyclin receptor gene in the human genome. The human prostacyclin receptor gene spanned approximately 7.0 kb and was composed of three exons separated by two introns. The first intron occurred in the 5'-untranslated region, 13 bp upstream to the ATG start codon. The second intron was located at the end of the sixth transmembrane domain, thereby separating it from the downstream coding region and the 3'-untranslated region. By primer extension analysis, the transcription initiation sites were mapped 870-872 bp upstream to the ATG start codon. The 1.2-kb human prostacyclin receptor 5'-flanking region lacked conventional TATA and CCAAT boxes, but it contained several cis-acting regulatory elements including an inverted CCAAT box (Y box) and two copies of SP-1 binding sites. Using human-rodent somatic hybrid cell DNA, the human prostacyclin receptor gene was assigned to human chromosome 19. The present study helps establish the genetic basis for prostacyclin receptor research and provides further insight into the molecular mechanisms underlying the prostanoid receptor family.

Amino Acid Sequence↗

PubMed1995

Expression of basic fibroblast growth factor and its receptor in human pancreatic carcinomas.

We examined the expression of basic fibroblast growth factor (FGF) and FGF receptor by immunohistochemistry in 32 human pancreatic ductal adenocarcinomas. Mild to marked basic FGF immunoreactivity was noted in 19 (59.4%) of the 32 tumours examined, and 30 (93.3%) of the tumours exhibited a cytoplasmic staining pattern against FGF receptor. The tumours were divided into two groups according to the proportion of positively stained tumour cells: a low expression group (positive cells < 25%) and a high expression group (positive cells > or = 25%). No statistically significant difference in tumour size, differentiation, metastases or stage was found between the low and high basic FGF expression groups. However, a significant correlation was found between FGF receptor expression level and the presence of retroperitoneal invasion, lymph node metastasis, and tumour stage. In addition, low FGF receptor expression was significantly associated with a longer post-operative survival as compared with high FGF receptor expression, whereas there was no significant difference in post-operative survival between the low and high basic FGF expression groups. Increased expression of FGF receptor is correlated with the extent of malignancy and post-operative survival in human pancreatic ductal adenocarcinomas. Thus, overexpression of FGF receptor may prove to be a more useful prognostic marker than basic FGF expression level in pancreatic cancer patients.

Adult↗

PubMed1994

Molecular cloning and chromosomal assignment of the mouse C-type natriuretic peptide (CNP) gene (Nppc): comparison with the human CNP gene (NPPC).

The mouse C-type natriuretic peptide (CNP) genomic fragment was isolated from a mouse genomic DNA library. The mouse CNP gene is composed of at least two exons and one intron. The 5'-flanking region contains an array of cis-acting regulatory elements and a dinucleotide CA repeat (microsatellite). Analysis of the deduced amino acid sequences revealed that mouse preproCNP is a 126-amino-acid peptide and that its C-terminal 22-residue peptide preceded by Lys-Lys is identical to porcine, rat, and human CNPs. On the basis of the polymerase chain reaction-analyzed microsatellite length polymorphisms among recombinant inbred strains of mice, the CNP gene (Nppc) was assigned to mouse chromosome 1. Furthermore, the human CNP 5'-flanking region was extended for sequencing, and comparison of the mouse and human CNP genomic sequences revealed regions of conservation and diversity. Using somatic hybrid cell methodology, the CNP gene (NPPC) was assigned to human chromosome 2. The present study has added another locus to the conserved syntenic group in mice and humans.

Amino Acid Sequence↗

PubMed1994

Cell adhesion activity of a 30-kDa major secreted protein from human bladder carcinoma cells.

Human bladder carcinoma cell line EJ-1 secreted a protein of 30 kDa as a major component. This protein was purified from the serum-free conditioned medium of EJ-1. Its N-terminal amino acid sequence was identical to that of fibroblast-derived endothelial cell growth factor (f-ECGF), but there were differences in their amino acid compositions and isoelectric points. The 30-kDa protein showed no effect on the growth of bovine capillary endothelial cells, but it promoted the attachment and spreading of rat liver cell line BRL and human umbilical vein endothelial cell line ECV-304. These results suggest that the 30-kDa protein, tentatively named "tumor-derived adhesion factor (TAF)", may be related with the aberrant cell adhesion of cancer cells.

Amino Acid Sequence↗

PubMed1993

Basic fibroblast growth factor in rat salivary glands.

We studied the occurrence and localization of basic fibroblast growth factor (bFGF) in rat salivary glands using a specific monoclonal antibody. It was shown that the extract of rat salivary glands has a pronounced stimulatory activity on the growth of bovine capillary endothelial cells, which is blocked by the addition of an antibody against bFGF. The concentration of bFGF in the submandibular/sublingual gland, as determined by radioimmunoassay, was approximately 80% that in the brain. Immunocytochemistry revealed bFGF-immunoreactivity localized primarily in the epithelial cells lining the striated ducts and excretory ducts of the parotid, sublingual and submandibular glands. In addition, intense bFGF-immunoreactivity was observed in the granular convoluted tubule of the submandibular gland, localized predominantly in the agranular pillar cells, which lay in small numbers among the majority of weakly immunostained cells containing many apical secretory granules. At the electron-microscopic level, the immunoreactive material was distributed diffusely in the cytoplasmic matrix and nuclei of all immunoreactive cells, whereas it was absent from all cytoplasmic organelles including the secretory granules. These results indicate that bFGF is localized in different cellular and subcellular compartments from those of other growth factors in the duct system of rat salivary glands.

Animals↗

PubMed1993

Peritubular endothelial cell proliferation in mice during compensatory renal growth after unilateral nephrectomy.

The proliferation of peritubular endothelial cells during compensatory renal growth (CRG) following unilateral nephrectomy in mice was investigated using a labeling index. The labeling index of peritubular endothelial cells increased 6 h after uninephrectomy and decreased to the normal level within 72 h. Immunohistochemical study revealed that c-myc protein was expressed in the nuclei of both cortical tubular cells and peritubular endothelial cells. Furthermore, intravenous injection of anti-basic fibroblast growth factor (bFGF) neutralizing antibody just after uninephrectomy led to significant inhibition of proliferation of peritubular endothelial cells, but not tubular cells. These results indicate that peritubular endothelial cells proliferate transiently during CRG and that bFGF plays an important role for the growth regulation of that cell in the kidney.

Animals↗

PubMed1993

In situ assay of basic fibroblast growth factor in cultured cells with a specific monoclonal antibody.

The localization of basic fibroblast growth factor (bFGF) in various cultured bFGF-producing cells, including bovine capillary endothelial (BCE) cells and human cholangiocellular carcinoma (HuCC-T1) cells, was determined by measuring binding of 125I-labeled specific monoclonal antibody against bFGF. bFGF on the cell surface and within the cells was determined by counting the radioactivity of the labeled monoclonal antibody bound to the cells before and after increasing their permeability by treatment with alcohol or Triton X-100. The radioactivity bound to these cells decreased with increase in the concentration of unlabeled monoclonal antibody. Scatchard analyses of these data suggested the quantitative localization of bFGF and Kd values showing the specific binding. This method was designated as in situ assay with radio-labeled antibody (ISARA). bFGF detected on the cell surface and within the cells could be partially removed by treatment with heparin or heparinase and with heparin or DNase, respectively. Exogenous bFGF bound to cells not producing bFGF was also quantified by ISARA. Measurements of bFGF in extracts of cells producing bFGF suggested that 8.3-13.3% of the bFGF associated with the cells was detected by ISARA. This method should be useful for quantitative confirmation of immunohistochemical results on bFGF.

Animals↗

PubMed1993

Immunocytochemical localization of basic fibroblast growth factor in the rat pituitary gland.

Immunohistochemical localization of basic fibroblast growth factor (bFGF) was studied in the rat pituitary gland at light and electron microscopic levels using a specific monoclonal antibody. In the anterior lobe, bFGF-immunoreactivity was found mostly in a cell population without secretory granules, which was identified as the folliculo-stellate (FS) cell by its ultra-structure and expression of S-100 protein. The subcellular localization of the immunoreactivity in FS cell was strictly nuclear. Besides the FS cell, a minor cell population containing small granules of 60-100 nm diameter, which seemed to represent immature endocrine cells, was immunostained in the nuclei with the anti-bFGF antibody. In the intermediate lobe, a subpopulation of the S-100 protein-positive cells lining the pituitary cleft was immunoreactive for bFGF. These results imply that the agranular cell types are the main producer and/or target of rat pituitary bFGF, and that bFGF may play a role in the differentiation of pituitary endocrine cells.

Animals↗

PubMed1993

[Relation of habitual exercise to basal metabolic rate and energy expenditure during exercise in older people].

The relation between habitual exercise and the basal metabolic rate, energy expenditure during exercise (lactic threshold and maximal oxygen uptake) was examined in 291 older people. Metabolic rate was highest in old players of gatebowl (a form of croquet) (male; 23.3 +/- 2.3, female; 22.7 +/- 3.0 kcal/kg/day), higher in old untrained people (male; 21.9 +/- 2.5, female; 20.8 +/- 2.4 kcal/kg/day), and lower in old people in a home for the aged (male; 20.6 +/- 3.5, female; 20.8 +/- 3.7 kcal/kg/day). Energy expenditure while walking at a speed of less than 100 m/min was similar in trained and untrained old people aged 60-69 years. However, lactic threshold was higher in trained (30.2 +/- 4.8 ml/kg/min) than in untrained (20.9 +/- 2.8 ml/kg/min) females aged 60-69 years. Maximal oxygen uptake was higher in trained (male; 50.4 +/- 4.1, female; 36.6 +/- 3.9) than in untrained (male; 30.9 +/- 3.7, female; 26.8 +/- 2.8) old people aged 60-69 years. It was suggested that a higher basal metabolic rate, lactic threshold and maximal oxygen uptake resulted in higher daily physical activity and larger daily energy consumption in trained old people.

Aged↗

PubMed1992

Direct effect of basic fibroblast growth factor on gene transcription in a cell-free system.

Recent findings on the translocation of intact fibroblast growth factor (FGF) into the cell nucleus suggest that it functions directly in nuclear events. We examined the effect of human basic FGF (bFGF) on gene transcription in a cell-free system. When mouse genes encoding phosphoglycerate kinases 1 and 2 (Pgk-1 and Pgk-2) were transcribed by using nuclear extracts of Ehrlich ascites tumor cells, FGF affected transcription in different ways: in the presence of bFGF, transcription of the Pgk-1 gene was inhibited, whereas that of the Pgk-2 gene was enhanced. When viral genes were tested, transcription of the adenovirus major late DNA was slightly stimulated but that of the adenovirus early E1A DNA or the human immunodeficiency virus DNA was not changed by the addition of bFGF. Moreover, the presence of a distinct 5' upstream region of the Pgk-2 gene, which includes a negative cis-acting element, was required for transcription stimulation by bFGF. These results suggest that bFGF can regulate transcription directly in the nucleus in a gene-specific manner.

Adenovirus Early Proteins↗

PubMed1992

Localization of basic fibroblast growth factor (bFGF) in a metastatic cell line (AT-3) established from the Dunning prostatic carcinoma of rat: application of a specific monoclonal antibody.

Localization of basic fibroblast growth factor (bFGF) in a metastatic cell line, AT-3, established from the Dunning prostatic carcinoma of rat was determined by two immunological techniques using a specific monoclonal antibody against bFGF. Concentration of bFGF in cell extract was measured by sandwich radioimmunoassay (RIA) with heparin-Sepharose and 125I-labeled monoclonal antibody. bFGF concentration in the extract of AT-3 cells increased with increasing concentration of NaCl in extraction buffer. Localization of bFGF in AT-3 cells was determined by counting radioactivity of 125I-labeled monoclonal antibody binding to AT-3 cells before or after increasing permeability of the cells. The binding increased significantly by this treatment, indicating that bFGF within the cells was detected.

3T3 Cells↗