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Biomedical subjects

Y Kano

Publications and source records attributed to Y Kano.

At least 109 records · Page 6Linked to original sources
PubMed1996

Macromolecular composition of stress fiber-plasma membrane attachment sites in endothelial cells in situ.

Stress fibers (SFs) are present along the apical (apical SF) and the basal (basal SF) portions of cultured cells. We have recently shown that apical SFs are anchored to the apical plasma membrane (PM) in a manner similar to how basal SFs are attached to focal adhesion sites. We propose calling such apical SF-membrane attachment sites "apical plaques." To study the macromolecular composition of the apical plaque and the focal adhesion in endothelial cells (ECs) in situ, we examined by confocal laser scanning and fluorescence microscopy guinea pig aortae stained with various antibodies against focal adhesion-associated proteins. Basal SFs oriented parallel to the blood flow direction were mainly located in the upstream half of the cell. Thin apical SFs were also observed. Spotty staining patterns were observed in the basal and the apical portions of cells stained with anti-vinculin, anti-talin, anti-paxillin, or anti-fibronectin receptor, indicating the presence of focal adhesions and apical plaques in ECs in situ. Although fibronectin receptors were present in the apical plaque, fibronectin was not detected on the apical cell surface. Our data suggest that the molecules responsible for the SF-PM association are the same between in vitro and in situ cells. Our results appear to support a hypothesis that the SF system is involved in sensing and/or signal transduction of fluid mechanical forces.

Animals↗
PubMed1996

Mutually exclusive distribution of the focal adhesion associated proteins and the erythrocyte membrane skeleton proteins in the human fibroblast plasma membrane undercoat.

The ends of stress fibers in the basal portion of cells (basal stress fibers) are anchored to focal adhesions, and stress fibers in the apical part of cells (apical stress fibers) are attached to the apical membrane, forming a structure (the apical plaque; KATOH, K. et al. (1995). Cell Motil. Cytoskel., 31: 177-195) resembling the focal adhesion. In addition to these two sites, stress fibers also make lateral contact with the plasma membrane but little is known about the molecular composition of this type of stress fiber-membrane interaction sites. Several actin-membrane association types are known, each employing a different set of proteins, and the focal adhesion and the erythrocyte membrane skeleton are the best characterized systems. We investigated by immunofluorescence microscopy if there is any morphological basis for the involvement of the erythrocyte membrane proteins in the stress fiber-plasma membrane association sites in cultured human fibroblasts. Our results indicated that fodrin (nonerythrocyte type spectrin) and ankyrin were generally associated with the plasma membrane, but that they were clearly excluded from the focal adhesion, the apical plaque and the stress fiber. Thus, it appears that the spectrin and the integrin based actin-membrane association systems are mutually excluded in the fibroblast membrane undercoat. Protein localization at the lateral stress fiber-membrane association site was also studied. Our data indicated that, while talin, vinculin, paxillin, fibronectin receptor and integrin beta 1 were present at the three stress fiber-membrane association sites, vitronectin receptor and integrin alpha v were absent from the apical plaque and the lateral association site. While the plasma membrane at the focal adhesion adheres tightly to a solid substrate, the cell surface of the apical plaque is free. Although the lateral association site faces the substrate, the molecular composition of this site is similar to that of the apical plaque.

Actin Cytoskeleton↗
PubMed1996

Pharmacological properties of traditional medicines. XXII. Pharmacokinetic study of mulberroside A and its metabolites in rat.

To identify the active components in Mori Cortex (Chinese medicine), Mori Cortex extracts were administered orally to rats, and then blood plasma, urine, and bile were analyzed. The results showed only a few remaining metabolites of mulberroside A. Consequently, to clarify the transitional properties of mulberroside A derivatives to tissues and the in vivo abundance ratio of mulberroside A compounds, the pharmacokinetics of mulberroside A derivatives were investigated in this study. When Mori Cortex extracts were administered orally, mulberroside A was only detected in small quantities in the plasma, and its bioavailability was about 1%. This is due to the first pass effect, by which most mulberroside A was converted into oxyresveratrol and transported into the circulating blood, and its absorption ratio was estimated at about 50%. Oxyresveratrol was found to be transported to tissues at high rates. As a result, when analyzing the pharmacological activity of the Mori Cortex in vitro, it is more useful to study oxyresveratrol than mulberroside A.

Animals↗
PubMed1996

Urinary and biliary metabolites of genistein in rats.

Examination was made of the urinary and biliary excretion of the metabolites of genistein and genistein, the major components of Glycine and Sophora genus in rats. The urine of rats administered genistein orally contained eight metabolites. Three of these metabolites, genistein 4'-O-sulfate (M-1), genistein 7-O-beta-D-glucuronide (M-3), genistein 4'-O-sulfate 7-O-beta-D-glucuronide (M-6), were identified from spectroscopic and chemical data. The bile of rats administered genistein orally contained M-2, M-3 and M-6. M-6, a major biliary metabolite, was isolated and identified from spectroscopic and chemical data. The urine or bile of rats treated with genistein, the glycoside of genistein, contained M-1-M-8 or M-2, M-3, M-6 in the above metabolites. These findings suggest that genistein is absorbed as genistein after hydrolysis in the gastrointestinal tract. The total cumulative amounts of the two metabolites and genistein excreted in the urine during 48h, or of M-6 excreted in the bile during 36h following the oral administration of genistein, were approximately 5.7% or 16.0% of the doses administered, respectively. The result show that M-1, M-3 and M-6, having a free hydroxyl, glucuronide- or sulfate-conjugated hydroxyls at the C-7 or C-4' position, are excreted in the urine and bile as parts of the metabolites of genistein.

Animals↗
PubMed1996

Cloning of cDNA with possible transcription factor activity at the G1-S phase transition in human fibroblast cell lines.

Normal human fibroblasts have a finite proliferative capacity in vitro. Thus, immortalization of human cells is associated with cellular aging. We have established an immortalization-sensitive cell line from fibroblasts of Wilms' tumor patients which have a partial deletion of chromosome 1 1p. This cell line was easily immortalized by introducing SV4OT. By differential hybridization using both SV4OT-introduced crisis cells and young cells, we cloned a gene that was highly expressed in 1 1p-cells at the time of the crisis and named this gene C-1. Nucleotide sequence analysis of C-1 revealed that it contains a helix-loop-helix domain, indicating that it may be a transcription factor. Expression of the C-1 gene was transiently induced early in the G0-to-S phase transition in two normal human (OUMS-24 and HSF-412) and a non-tumorigenic immortal human (OUMS-24F) fibroblast cell lines, while the other immortal SUSM-1 cells highly expressed the C-1 gene in the middle G1 phase. These results suggest that the C-1 gene product may function as a transcription factor related to the cell cycle.

Amino Acid Sequence↗
PubMed1996

Expression and distribution of myoepithelial cells in developing bovine parotid gland.

The expression and distribution of myoepithelial cells in relation to parotid acinar cells were studied immunohistochemically in bovine fetuses and neonates. Definitive myoepithelial cells first appeared as slender, brown short lines around the perimeters of developing secretion acini at four months of fetal age (in a 26 cm long fetus). At this time, parotid acinar cells possessed no distinct secretory granules in the supranuclear region. The differentiation of myoepithelial cells subsequently progressed during late gestation and birth. In neonates, the myoepithelial cells surrounded the secretory acini and parts of the intercalated ducts.

Animals↗
PubMed1996

[Effects of carboplatin combination with etoposide against leukemia/lymphoma cell lines].

We studied the effects of carboplatin in combination with etoposide in human B-cell lymphoma cell lines, BALL-2, Dauji and human T-cell leukemia cell lines, CEM, HSB and MOLT-3 cells. Cells were incubated for 3 days in the presence of carboplatin and etoposide, and the combined drug and cell growth inhibition was determined by MTT assay. The effects of drug combinations at ID80 were analyzed by an improved isobologram method (Steel and Peckham). In the combination of carboplatin with etoposide, the data points fell in the envelope of additivity (additive effect) in all five cell lines. Synergistic and antagonistic effects were not observed. These findings suggest that the combination of carboplatin and etoposide are as effective as expected.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Nodular cutaneous lupus mucinosis: report of a case and review of previously reported cases.

A wide variety of cutaneous manifestations of lupus erythematosus have been reported. Among them, papulonodular eruptions produced by dermal mucin deposition have been recognized as nodular cutaneous lupus mucinosis (NCLM), and many cases have been reported in Japan. A 21-year-old woman with systemic lupus erythematosus (SLE) showed papulonodular eruptions on her back. A skin specimen from the nodule revealed mucin deposition (hyaluronic acid) in the dermis. NCLM should be recognized as a clinical form associated with SLE. The pathogenesis of the mucin deposition in NCLM is still uncertain.

Adult↗
PubMed1995

Role of HU proteins in forming and constraining supercoils of chromosomal DNA in Escherichia coli.

Induction of supercoiling in plasmid DNA by HU heterotypic and homotypic dimers, a mutant HU-2 (HupAN12), HBs and HB1 proteins with different DNA-binding affinities was investigated in vitro. The abilities of these proteins to induce supercoiling in DNA correlated with their affinities for DNA. Stoichiometrical analysis of HU heterodimers bound to DNA in the complex restraining the negative torsional tension of DNA showed that 12-13 dimers account for a single superhelical turn. The number of supercoils in the plasmid in vivo decreased on inhibition of DNA gyrase with coumermycin, reaching a steady-state level that indicated the existence of a compartment of restrained supercoils. The size of the restrained compartment was reduced in the absence of HU, indicating the participation of HU in constituting this fraction, and was larger on overproduction of HU-2 in the cells. An increased level of DNA gyrase, expressed from a plasmid carrying both gyr genes, in the cells did not compensate for the deficit of the restrained supercoils caused by HU deficiency, indicating seeming distinct and unrelated action of HU and DNA gyrase in introducing and constraining supercoiling of intracellular DNA.

Bacterial Proteins↗
PubMed1995

Focal adhesion proteins associated with apical stress fibers of human fibroblasts.

Human fibroblasts stained with fluorescently labeled phalloidin revealed many stress fibers within the apical cytoplasm in addition to those located along the basal plasma membrane and associated with focal adhesions. The staining patterns of these apical stress fibers with fluorescent phalloidin, anti-alpha-actinin, and antimyosin were identical to those of the basal stress fibers, suggesting the same macromolecular organization for both types of stress fibers. There were two types of apical stress fibers that clearly interacted with the apical plasma membrane, those extending between the basal and the apical plasma membrane and those having both ends on the basal membrane forming arches whose top interacted with the apical plasma membrane. By electron microscopy, we observed that apical stress fibers were associated with the apical plasma membrane via electron-dense plaques reminiscent of the focal adhesion. Since several proteins have been specifically localized to the focal adhesion site, we examined whether they were also present at the apical stress fiber-membrane association site by using immunocytochemical methods and image reconstruction techniques. We found that vinculin, talin, paxillin, a fibronectin receptor protein, several integrin subunits including beta 1, fibronectin, and proteins with phosphorylated tyrosine were also components of the apical plaque. These observations indicate that apical stress fibers are attached to the plasma membrane by using principally the same molecular assembly as the focal adhesion associated with the basal stress fiber. We suggest that the complex molecular organization of the focal adhesion is not demanded by cell adhesion, but rather it is needed for anchoring stress fibers to the plasma membrane. Apical plaques did not stain with the anti-integrin alpha v subunit or anti-focal adhesion associated kinase (FAK), although these antibodies stained focal adhesions. These results suggest that the apical stress fiber-membrane contact has some important functions different from those of the focal adhesion.

Antibody Specificity↗
PubMed1995

Schedule-dependent interaction between paclitaxel and doxorubicin in human cancer cell lines in vitro.

The schedule-dependent interaction of paclitaxel and doxorubicin was evaluated in four human cancer cell lines. The cells were exposed simultaneously or sequentially to the two agents for 24 h, and were then incubated in drug-free medium for 4 and 3 days, respectively. The cell growth inhibitions were determined by the MTT assay. The cytotoxic interactions at the IC80 level were evaluated by the isobologram method of Steel and Peckham. In non-small cell lung cancer A549, breast cancer MCF7 and colon cancer WiDr cells, antagonistic effects were observed for the paclitaxel and doxorubicin combination on simultaneous exposure to the two agents and on sequential exposure to doxorubicin followed by paclitaxel, while additive effects were observed for the combination on sequential exposure to paclitaxel followed by doxorubicin. In ovarian cancer PA1 cells, additive effects were observed for all schedules. These findings suggest that sequential administration of paclitaxel followed by doxorubicin may be the most suitable sequence, while the simultaneous administration of the two agents and the sequential administration of doxorubicin followed by paclitaxel may result in less tumour cell kill than anticipated. Further preclinical and clinical studies are required to elucidate the relationship between paclitaxel and doxorubicin with regard to both antitumour activity and toxicity.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Erythema nodosum, lichen planus and lichen nitidus in Crohn's disease: report of a case and analysis of T cell receptor V gene expression in the cutaneous and intestinal lesions.

A wide variety of cutaneous manifestations have been described in association with Crohn's disease (CD). We describe a patient with a 2-year history of CD who developed both lichen planus (LP) and lichen nitidus (LN) in addition to erythema nodosum (EN) lesions. The clinical course of EN reflected the activity of the bowel disease, whereas LP and LN appeared to persist independently of the ongoing disease activity. Immunohistochemical studies of the infiltrates in these cutaneous and intestinal lesions showed that the majority of the infiltrates were T cells expressing T cell receptor (TCR)-alpha beta. Analyses of TCR V gene expression in these infiltrating T cells demonstrated a different pattern of V beta expression that provides an explanation for the difference in the clinical courses of these lesions. LP and LN lesions are likely to be mediated by T cells with antigen specificity distinct from those that cause EN and intestinal lesions.

Adult↗
PubMed1995

Urinary and biliary metabolites of puerarin in rats.

Examination was made of the urinary and biliary excretion of the metabolites of puerarin, the major component of the roots of Pueraria lobata OHWI (Leguminosae) in rats. The urine of rats administered puerarin orally contained puerarin and four major metabolites, daidzein 4',7-di-O-sulfate (M-I), daidzein 7-O-beta-D-glucuronide (M-II), daidzein 4'-O-sulfate (M-III), daidzein (M-IV), as determined from spectroscopic and chemical data. Total cumulative amounts of the puerarin and four metabolites excreted in the urine at 48 h following the oral administration of puerarin were approximately 3.6% the doses administered. The bile of rats administered puerarin orally contained puerarin and two major metabolites, which were identified as puerarin 4'-O-sulfate (PB1) and puerarin 7-O-beta-D-glucuronide (PB2) on the basis of chemical and spectroscopic data. These experimental data suggest that C-glycoside puerarin is partially hydrolyzed to aglycone in the body, but mainly excreted in the urine as unchanged puerarin.

Animals↗
PubMed1994

IHF supresses the inhibitory effect of H-NS on HU function in the hin inversion system.

In the hin-mediated DNA inversion system, HU facilitates formation of the synaptic complex composed of two recombination sites spaced 996 bp apart and of the enhancer situated between them, by looping the DNA as to promote interaction of Hin invertase with the Fis enhancer factor [Johnson et al., Nature 329 (1987) 462-465]. The HU requirement for the in vivo hin-mediated inversion was demonstrated previously [Wada et al., Gene 76 (1989) 345-352; Hillyard et al., J. Bacteriol. 172 (1990) 5402-5407; Haykinson and Johnson, EMBO J. 12 (1993) 2503-2512] and in the current experiments. This HU action, however, required IHF when H-NS was present in the cell; i.e., the inversion reaction of the hin-invertible DNA fragment carried by the pKK1202R plasmid proceeded efficiently in host cells either deficient in H-NS or in the presence of both H-NS and IHF, but not in the cells depleted for IHF alone. The level of hin mRNA in mutant cells lacking HU or IHF, in which hin inversion did not occur, was normal or slightly increased. When IHF was absent, the stimulating effect of HU on in vitro DNA circle formation of a 125-bp hin fragment between hixL and the enhancer where Fis binds was inhibited by H-NS. The present study provides an example of a multi-component interaction between HU, H-NS and IHF on the hin DNA region, which contains three characteristic sites, a d(A/T)4 stretch and bent DNA site, and two putative IHF-binding sites.

Bacterial Outer Membrane Proteins↗
PubMed1994

Expression of carbonic anhydrase isozymes II and III in developing bovine parotid gland.

Two cytosolic carbonic anhydrase isozymes (CA-II and CA-III) were studied by immunohistochemistry in bovine parotid glands during fetal development. In a 3-month-old fetus of crown-rump length (CRL) 17 cm, the expression of CA-II in undifferentiated epithelial cells was observed, whereas immunostaining for CA-III remained negative. At 26 cm CRL (4-5 months old), weak expression of CA-III in large ductal epithelial cells was noted. The accumulation of secreted granules in primary acinar cells was initially observed at this stage. In a newborn calf, anti-CA-II reactivity almost disappeared from most duct segments. The time-dependent expression and distribution of the isozymes in parotid glands may reflect different biological functions of these structurally closely related isozymes. Bovine parotid acinar cells of fetuses would thus appear to possess all the cellular structures and immunohistochemical properties at 4 and 5 months of gestation. CA-II subsequently disappeared from duct segments and nearly all acinar cells in adults were present at or just after birth.

Animals↗