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Biomedical subjects

A Kikuchi

Publications and source records attributed to A Kikuchi.

At least 325 records · Page 18Linked to original sources
PubMed1992

Effects of tumor necrosis factor alpha, interferon alpha and interferon gamma on non-lymphoid leukemia cell lines: growth inhibition, differentiation induction and drug sensitivity modulation.

The potential role of tumor necrosis factor alpha (TNF alpha), interferon alpha (IFN alpha) and interferon gamma (IFN gamma) in the therapy of non-lymphoid leukemia was studied in ten non-lymphoid leukemia cell lines. All three cytokines tested inhibited the growth of the cell lines. However, a high degree of variability in susceptibility to cytotoxic/cytostatic effect of the cytokines was found among individual cell lines. Some cell lines were sensitive to the antiproliferative action of only one of the cytokines tested, but were resistant to the others. Combinations of two cytokines had additive or synergistic effects and inhibited cell growth to a greater extent than did the individual cytokines alone. In addition to the growth-inhibitory effect, the cytokines induced an apparent cell differentiation. The differentiation of the two most sensitive cell lines, EoL-1 and PL-21, was confirmed using the nitroblue tetrazolium reduction test, by changes in cell morphology, immunophenotype marker profiles and by changes in c-myb expression. Furthermore, we showed that even in the cell lines relatively resistant to the antiproliferative effect of cytokines, such as cell line KCL-22, the inhibition of cell growth could be markedly increased with the DNA-topoisomerase-II-targeted drug, doxorubicin. Our data thus suggest that TNF alpha, IFN alpha and IFN gamma together have a potential role in the immunotherapy of non-lymphoid leukemia in terms of their antiproliferative action, and their ability to induce differentiation and to modulate drug sensitivity.

Cell Differentiation↗
PubMed1992

Association of ras p21 with differentiation of epidermal keratinocytes in proliferating skin diseases.

We examined the localization of DNA replicating cells and ras oncogene product p21 positive cells in proliferating skin diseases, such as psoriasis vulgaris, lichen planus, verruca vulgaris, verruca plana juvenilis and seborrheic keratosis. ras p21-positive cells were found rather in the differentiated layers than in the proliferating layers of the epidermis. We indicate that the expression of ras p21 can be associated with the differentiation of epidermal keratinocytes not only in tumor tissues but also in inflammatory skin disease.

Cell Differentiation↗
PubMed1992

CD8+ cutaneous anaplastic large-cell lymphoma: report of two cases with immunophenotyping, T-cell-receptor gene rearrangement and electron microscopic studies.

Two cases are reported of cutaneous anaplastic large-cell lymphoma with the suppressor/cytotoxic (CD8) phenotype. In both cases there was a solitary skin tumour in which there was a dense infiltrate with large irregularly shaped cells which on immunophenotyping expressed CD8. DNA hybridization analysis showed rearrangements of the T-cell-receptor gene in both cases.

Aged↗
PubMed1992

Microinjection of smg/rap1/Krev-1 p21 into Swiss 3T3 cells induces DNA synthesis and morphological changes.

Microinjection of either Ki-rasVal-12 p21 or the GDP-bound form of Ki-ras p21 plus smg GDP dissociation stimulator (GDS), a stimulatory GDP/GTP exchange protein for Ki-ras p21, smg/rap1/Krev-1 p21, and rho p21, into quiescent Swiss 3T3 cells induced DNA synthesis irrespective of the presence or absence of insulin. The guanosine 5'-(3-O-thio)triphosphate (GTP gamma S)-bound form of smg p21B or the GDP-bound form of smg p21B plus smg GDS also induced DNA synthesis but only in the presence of insulin. Either the GDP-bound form of Ki-ras p21 or the same form of smg p21B alone was inactive, but smg GDS alone was slightly active only in the presence of insulin. The morphology of the cells was analyzed by scanning electron, phase-contrast, and confocal laser scanning microscopies. Ki-rasVal-12 p21 induced membrane ruffling irrespective of the presence or absence of insulin. The GTP gamma S-bound form of smg p21B showed the same effect only in the presence of insulin. Either the GDP-bound form of Ki-ras p21, the same form of smg p21B, or smg GDS alone was inactive. Upon microinjection of Ki-rasVal-12 p21, stress fibers markedly decreased and the cells became round and piled up. In contrast, upon microinjection of the GTP gamma S-bound form of smg p21B, stress fibers did not markedly decrease and the cells neither became round nor piled up. These results indicate that both ras p21 and smg p21 are mitogenic in Swiss 3T3 cells but that their actions are slightly different.

3T3 Cells↗
PubMed1992

Distribution of smg p25A and smg p21s, ras p21-like guanine nucleotide-binding proteins, in the rat stomach.

Existence and distribution of small guanine nucleotide binding proteins (G proteins) such as smg p25A, smg p21s, and ras p21s were examined in the rat gastric mucosa. By immunoblot analysis using the specific monoclonal antibodies against smg p25A and ras p21 and the anti-smg p21 antiserum, smg p25A and smg p21s were detected in the gastric mucosa, while ras p21s were not detected. In immunocytochemical studies, moderate fluorescence of smg p25A was homogenously seen in the cytoplasmic portions of chief cells and surface epithelial cells. smg p21 immunoreactivity was detected in glandular cells and submucosal muscle layer in the mucosa. On the other hand, the cells constituting gastric glands were unstained with the anti-ras p21 monoclonal antibody, RASK-4. These results suggest that smg p25A and smg p21s exist as in other tissues and might exert their specific actions in the rat gastric mucosa.

Animals↗
PubMed1992

Adhesion and proliferation of bovine aortic endothelial cells on monoamine- and diamine-containing polystyrene derivatives.

Adhesion and proliferation of bovine aortic endothelial cells on polystyrene derivatives having monoamine or diamine side chain was investigated focusing on the chemical structure of amino groups. Copolymers, SE8.5, is composed of polystyrene with 8.5 mol% of monoamine side chains, and SED8, which is with 8 mol% of diamine side chains, were estimated to contain almost the same amount of protonated amino groups in bulk composition at physiological pH (pH 7.4). There observed significant difference in cellular spreading of attached endothelial cells between these two types of copolymer surfaces. Spreading-% of attached cells on SED8 surfaces was approximately 1.6 times greater than that on SE8.5 6 h after seeding. This difference in cellular spreading influenced to subsequent cell growth. Cellular growth on each polymer surface was featured by parameter k, which corresponds to the 'rate constant' of cellular proliferation. While the k-value for SE8.5 decreased with decreasing seeding density as well as the case for polystyrene, SED8 maintained a high k-value even at low seeding density as 2 x 10(3) cells/cm2. These results suggest that cells may recognize the difference in the chemical structure of amine side chains of SE and SED copolymers.

Amines↗
PubMed1992

The role of protonation and conformational transition of polyamine grafts in platelet retention to polyamine-graft-PHEMA copolymer surfaces.

Blood platelet retention on polyamine-graft-poly(2-hydroxyethyl methacrylate) (PHEMA) copolymer (HA) surface was investigated, focusing on pH and ionic strength of the surrounding medium to elucidate the nature of ionic interaction between platelets and HA copolymer surfaces. The conformational transition of polyamine graft chain in response to the protonation degree of amino groups was demonstrated to be an important factor influencing platelet retention on HA surfaces. When the polyamine graft chain exists in an extended conformation, protonated amino groups distribute from the matrix interface into the aqueous interior, resulting in the effective ionic interaction with platelets to increase their retention on HA copolymer surfaces. The number of protonated amino groups in polyamine portions crucially affected platelet retention. Worth noticing is that an introduction of a small but definite amount of cationic sites on the polymer surface led to significantly minimized platelet retention. It is considered that the surface property of PHEMA was drastically changed to a non-adhesive surface by introducing a small amount of protonated amino groups.

Animals↗
PubMed1992

Pharmacological properties of the novel highly potent diuretic 7-chloro-2,3-dihydro-1-(2-methylbenzoyl)-4(1H)-quinolinone 4-oxime-O-sulfonic acid potassium salt.

7-Chloro-2,3-dihydro-1-(2-methylbenzoyl)-4(1H)-quinolinone 4-oxime-O-sulfonic acid potassium salt (M17055, CAS 114417-20-8) showed potent diuretic and saluretic effects dose-dependently, in rats (p.o.), mice (p.o.) and dogs (i.v.), at doses of 0.1-100 mg/kg, 0.3-100 mg/kg and 0.01-30 mg/kg, respectively. The efficacy of M17055 for diuresis, natriuresis and chloruresis was much higher than that of hydrochlorothiazide and almost the same as that of furosemide. These results indicate that this compound may be classified as a "high ceiling diuretic". The potencies of M17055 for natriuresis in rats (p.o.), mice (p.o.) and dogs (i.v.) calculated with ED50 values were 38, 34 and 24 times, respectively, more potent than those of furosemide. Urinary excretions of sodium, chloride and potassium increased in parallel with urinary volume with the administration of M17055 or furosemide, whereas an apparent dissociation with urinary calcium and sodium excretion was observed with M17055 alone. In rats, the increase of urinary calcium excretion with M17055 was significantly lower than that with furosemide under comparable conditions of natriuresis. Moreover, in mice, M17055 decreased urinary calcium excretion at doses with low effectiveness. In clearance studies using anesthetized dogs, M17055 suppressed negative free water clearance (CH2O) under saline loaded conditions, and it decreased positive CH2O under water diuretic conditions. These changes in the effects on CH2O induced by M17055 resemble those of loop diuretics. However, M17055 could not shift negative CH2O to positive, while furosemide was able to do so. Moreover, positive CH2O decreased to nearly zero with M17055, while urine remained dilute with furosemide even at 30 mg/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

The functional domain of the stimulatory GDP/GTP exchange protein (smg GDS) which interacts with the C-terminal geranylgeranylated region of rap1/Krev-1/smg p21.

rap1/Krev-1/smg p21 (smg p21), a member of the small GTP-binding protein (G protein) superfamily, has a geranylgeranylated cysteine residue and clustered basic amino acids in the C-terminal region. The GDP/GTP exchange reaction of smg p21 is regulated by smg GDS, which is also active on Ki-ras p21 and rho p21. The C-terminal region of smg p21 is essential for its interaction with smg GDS. Moreover, smg p21 is phosphorylated by cyclic AMP- and cyclic GMP-dependent protein kinases at the serine residue between the polybasic region and the prenylated cysteine residue, and this phosphorylation initiates the smg GDS-induced smg p21 activation. Thus, the C-terminal cationic and hydrophobic region is important for the regulation of the smg p21 activity. In the present study, we attempted to determine the functional domain of smg GDS which interacts with the C-terminal region of smg p21 by use of a cross-link method and a site-directed mutagenesis method. The region of smg GDS cross-linked with the C-terminal region of smg p21B was residues 444-492, which is located at the C-terminal fifth of smg GDS. On deletion of these residues, smg GDS became inactive on smg p21B, Ki-ras p21 and rhoA p21. These results indicate that residues 444-492 of smg GDS are at least one of the domains which interact with the C-terminal region of its substrate small G proteins.

Amino Acid Sequence↗
PubMed1992

Molecular cloning of the human cDNA for a stimulatory GDP/GTP exchange protein for c-Ki-ras p21 and smg p21.

We have previously purified smg GDP dissociation stimulator (GDS) from bovine brain and isolated its cDNA from a bovine brain cDNA library. smg GDS stimulates the GDP/GTP exchange reaction of a group of small GTP-binding proteins (G proteins), including at least c-Ki-ras p21, smg p21A, smg p21B, rhoA p21 and rhoB p21, by stimulating the dissociation of GDP from and the subsequent binding of GTP to each small G protein. In this study, we have isolated and sequenced the cDNA of smg GDS from a human brain cDNA library using the cloned bovine smg GDS cDNA. The cDNA has an open reading frame encoding a protein of 558 amino acids with a calculated Mr value of 61,122. Human smg GDS shares 93% nucleotide and 96% amino acid sequence homologies with bovine smg GDS. The isolated cDNA is expressed in Escherichia coli, and the encoded protein shows the physical and functional properties similar to those of bovine smg GDS.

Amino Acid Sequence↗
PubMed1991

Introduction of disease-related mitochondrial DNA deletions into HeLa cells lacking mitochondrial DNA results in mitochondrial dysfunction.

Mutant mitochondrial DNA with large-scale deletions (delta-mtDNA) has been frequently observed in patients with chronic progressive external ophthalmoplegia (CPEO), a subgroup of the mitochondrial encephalomyopathies. To exclude involvement of the nuclear genome in expression of the mitochondrial dysfunction characteristic of CPEO, we introduced the mtDNA of a CPEO patient into clonal mtDNA-less HeLa cells and isolated cybrid clones. Quantitation of delta-mtDNA in the cybrids revealed that delta-mtDNA was selectively propagated with higher levels of delta-mtDNA correlating with slower cellular growth rate. In these cybrid clones, translational complementation of the missing tRNAs occurred only when delta-mtDNA was less than 60% of the total mtDNA, whereas accumulation of delta-mtDNA to greater than 60% resulted in progressive inhibition of overall mitochondrial translation as well as reduction of cytochrome c oxidase activity throughout the organelle population. Because these cybrids shared the same nuclear background as HeLa cells, these results suggest that large-scale deletion mutations of mtDNA alone are sufficient for the mitochondrial dysfunction characteristic of CPEO.

Adolescent↗
PubMed1991

Replication of the simian virus 40 chromosome with purified proteins.

SV40 chromosomes prepared from infected CV-1 cells were replicated with the purified proteins of SV40 T antigen, HeLa DNA polymerase alpha-primase complex, single-stranded DNA-binding protein, and topoisomerases I and II, all of which have been shown to be essential for SV40 DNA replication in vitro. Replication started near the origin and proceeded bidirectionally. The maximum speed of replication fork movement was 200-300 nucleotides/min, which was similar to the rate of SV40 DNA replication with the same set of proteins. When replication products were digested with micrococcal nuclease, DNA fragments of 160-180 base pairs, which is the typical size of mononucleosomal DNA, were protected. This result indicates that replicated DNA was reconstructed into the nucleosome structure, complexed with parental histones.

Antigens, Polyomavirus Transforming↗
PubMed1991

Similarity of expression of low molecular weight G proteins smg p21A and ras p21 in normal and malignant human tissues.

We prepared monoclonal antibodies specific for smg p21A, one of the low molecular weight GTP-binding proteins and possibly a suppressor molecule for ras p21. Two monoclonal antibodies (T22 and T212) reacted with smg p21A but not with Ki-ras p21, both of which were produced by Escherichia coli. These two clones detected an Mr 21,000 band in one-dimensional immunoblotting of extracts of a human pancreatic cancer cell line which was indistinguishable from a band detected by RASK-3, a monoclonal antibody specific for ras p21. However, T22 and T212 detected a single spot in two-dimensional immunoblotting that was clearly different from the three spots detected in the same cellular extracts by RASK-3. A series of normal and malignant human tissues were examined for the expression of smg p21A and ras p21 by immunohistochemical methods utilizing T22 and RASK-3. In essentially all tissues examined, both normal and malignant, smg p21A and ras p21 were expressed with great similarity. Expression of both molecules in all malignant tissues examined was coincident with that in normal tissues except that gastric cancer showed increased expression of the two molecules in comparison with normal gastric tissue.

GTP-Binding Proteins↗
PubMed1991

Identification and molecular cloning of yeast homolog of nucleosome assembly protein I which facilitates nucleosome assembly in vitro.

Yeast DNA coding for nucleosome assembly protein I (NAP-I), which facilitates nucleosome assembly in vitro at physiological ionic conditions, was cloned and its gene product was characterized. A monoclonal antibody against NAP-I (58 kDa) from human HeLa cells was used to screen a genomic library of Saccharomyces cerevisiae constructed into lambda gt11. A 60-kDa protein was detected by immunoblotting in the extracts of Escherichia coli lysogenized with a positive clone. The 60-kDa protein purified from the extracts had an activity equivalent to that of NAP-I from mouse and human cells. The amino acid sequence deduced from the gene coding for the yeast NAP-I defines a polypeptide of molecular mass 47,848 Da with three negatively charged regions. While the two regions contain 8 and 10 acidic amino acids out of 13 amino acid residues, the longest stretch has 15 glutamic and 13 aspartic acids out of 38 residues. These regions are probably involved in the interaction with histones. Proteins recognized by the anti-NAP-I antibody were also present in Xenopus oocytes and Drosophila cultured cells. Possible roles of NAP-I are discussed in relation to other nucleosome assembly proteins.

Amino Acid Sequence↗