bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatocyte Regeneration after Partial Hepatectomy Occurs Even under Severely Thrombocytopenic Conditions in the Rat
Authors: Kuwashima Yoshio , Aoki Kazuko , Kohyama Kiyomi , Ishikawa Takatoshi
Published: August 2005

In order to investigate the role of blood platelets in regenerative proliferation of hepatocytes in vivo, partial hepatectomy was carried out under conditions of severe thrombocytopenia achieved by X‐irradiation and the time‐dependent degree of hepatocyte regeneration was measured as labeling index (LI) after 3H‐thymidine injection. LI values reached a maximum 36 h after hepatectomy performed 7 days subsequent to a whole‐body irradiation of 7.5 Gy, although the maximum rate was found to be only about one‐third of that found in unirradiated control rats. At this time point, the number of peripheral blood platelets was decreased to about 2% of that of unirradiated controls and bone marrow megakaryocytes were virtually undetectable. A decrease of LI, similar to that found for the whole‐body irradiation in degree, was also observed after local irradiation of the liver with the same dose but without an apparent decrease in platelets. When whole‐body irradiation was performed with the liver shielded, under which conditions the numbers of blood platelets decreased to about 8% of the control levels, almost no decrease in LI was found. The results thus suggest that the observed inhibition of hepatocyte regeneration was directly due to liver irradiation and that depletion of blood platelets itself does not interfere with the regeneration process, providing evidence against a dominant role of the platelets in the regeneration as proposed by other authors.
Loss of Heterozygosity on Chromosomes 1 and 11 in Sporadic Pheochromocytomas
Authors: Yokogoshi Yutaka , Yoshimoto Katsuhiko , Saito Shiro
Published: August 2005

Molecular genetic analysis was performed with 20 oncogene probes and 32 polymorphic DNA probes on tumor DNA samples from seven pheochromocytomas; namely, one multiple endocrine neoplasia type 2B, and two familial and four sporadic pheochromocytomas. No amplification or rearrangement of the oncogenes was detected in any of the tumors. However, loss of heterozygosity on chromosome 1p, 11p or 11q was detected in these cases. In addition, a locus related to ETS1 was deleted in two of the sporadic tumors. These results suggest that pheochromocytomas may be genetically heterogeneous, and that inactivation of unknown genes on chromosome 1p, 11p or 11q may contribute to their development.
Enhancement by Cysteinyl Thiols of Acetyltransferase‐mediated, but Not of Sulfotransferase‐mediated, Binding of a Pyrolysate‐derived N‐Hydroxyarylamine, 2‐Hydroxyamino‐6‐methyldipyrido[1,2‐a:3′,2′‐d]imidazole, to DNA
Authors: Abu‐Zeid Medhat , Staiano Norma , Yamazoe Yasushi , Kato Ryuichi
Published: August 2005

The effect of thiols on the activation of a pyrolysate‐derived N‐hydroxyarylamine, 2‐hydroxyamino‐6‐methyldipyrido[1,2‐a:3′,2′‐d]imidazole (N‐hydroxy‐Glu‐P‐1), was studied in vitro. In hepatic cytosol of rats, [3H]‐N‐hydroxy‐Glu‐P‐1 bound covalently to calf thymus DNA in the presence of acetyl CoA or 3′‐phosphoadenosine‐5′‐phosphosulfate (PAPS). The extent of the binding of N‐hydroxy‐Glu‐P‐1 in a PAPS‐dependent system was decreased by the addition of 10 mM glutathione, N‐acetyl‐l‐cysteine, 2‐mercaptoethanol or dithiothreitol. However, acetyl CoA‐dependent binding of N‐hydroxy‐Glu‐P‐1 was stimulated by the addition of 10 mM N‐acetyl‐l‐cysteine (3 fold), l‐cysteine (2 fold) or glutathione (1.2 fold), but not 10 mM 2‐mercaptoethanol or l‐methionine. After hydrolysis of the modified DNA, no difference was detected in the physicochemical properties of the nucleoside adduct formed in the acetyl CoA‐supported system with and without thiols. These results indicate that thiols with a cysteine residue are able to affect the activation of carcinogenic heterocyclic arylamines selectively by the modulation of the acetyltransferase‐mediated, but not the sulfotransferase‐mediated, pathway.
Immunohistological and Biochemical Detection of Fucosylated Polylactosamine Antigen with Monoclonal Antibody ACFH18 in Gastric Cancer and Normal Gastric Mucosa
Authors: Dohi Taeko , Abe Kazuo , Ohshiba Saburo , Yamaguchi Kenji , Oshima Mieko
Published: August 2005

A mouse monoclonal antibody ACFH18, produced by immunizing with human gastric cell line MKN‐74, recognizes a novel glycolipid antigen, fucosyl‐lactoneodecaosylceramide. In the present study, we investigated the immunohistological localization of this antigen and its biochemical detection in glycolipid fraction in normal and malignant human gastric tissue, compared with other tumor‐associated type‐2 chain glycolipid antigens such as sialyl Lex, sialyl Lex‐i and Ley. Reactivity with ACFH18 was detected immunohistologically in the proliferating zone of normal fundic gland region as well as in 38 of 54 cases of gastric cancer, with preferential binding to undifferentiated type cancer. Glycolipids reacting with ACFH18, especially slow‐migrating glycolipids on thin‐layer chromatography, were accumulated in all of four cancer specimens compared with normal mucosa obtained from the same patients. Many glycolipids with sialyl Lex or sialyl Lex‐i epitope were detected in normal mucosa and almost all of these glycolipids were accumulated in cancer specimens. Sialyl Lex‐i antigen was increased more specifically in cancer than sialyl Lex was. A Ley antigenic glycolipid was considerably decreased in three of four cancer cases and increased in one case. From these results, glycolipid detected by ACFH18 appeared to be a tumor‐associated antigen comparable to sialyl Lex and sialyl Lex‐i antigens, but with a unique character as an undifferentiated‐type tumor‐associated antigen.
Colony‐forming Ability in vitro and Clonology of Colorectal Cancer
Authors: Tanigawa Nobuhiko , Morimoto Hideki
Published: August 2005

One hundred and twenty‐three specimens (83 primary and 40 metastatic) of colorectal cancers from 102 patients were subjected to the human tumor clonogenic assay (HTCA) to determine the clonogenicities of tumor specimens stratified by the degree of histological differentiation and of tumor progression. No statistically significant differences in the clonogenicity were observed among the tumors with different histological differentiation. Viable malignant cells were abundant in the primary tumor specimens with submucosal (sm) and muscular layer (pm) invasion, and decreased significantly in number per gram of wet specimen as the tumors progressed (P<0.05). Clonogenicity was also higher in “smd” and “pm” primary tumor specimens, and decreased as the tumors advanced (P<0.05). These findings suggest that, at the onset or in the relatively early phase of the tumor progression, tumors are medullary and have a large fraction of clonogenic cells, and that they then develop more stroma while losing the clonogenic cell fraction by tumor progression. HTCA appears to be still valuable for analysis of the changes in biological properties over time in large bowel tumors.
Genotypic Differentiation of Intrahepatically Transplanted Hyperplastic Nodule Cells of Analbuminemic and Normal Rat Origin by Polymerase Chain Reaction
Authors: Nishikawa Yuji , Sakai Hirotsuka , Inagaki Mitsuhiro , Fukuda Ikue , Ogawa Katsuhiro , Nagase Sumi
Published: August 2005

DNA fragments encompassing the region of the seven‐base‐pair deletion in the albumin gene, which is a characteristic abnormality of Nagase's analbuminemic rat (NAR), were amplified by polymerase chain reaction, and we could differentiate the genotypes of normal rat, homozygous NAR and heterozygous NAR electrophoretically. This genotyping method was applied to the differentiation of hyperplastic nodules on immunostained tissue sections in the intrahepatic transplantation model. When the hyperplastic nodule cells of normal rat were transplanted to the livers of homozygous NAR, the donor cells were effectively differentiated from the host cells by the genotype.
Carcinogenicity of Sublimed Urethane in Mice through the Respiratory Tract
Authors: Nomura Taisei , Hayashi Terumasa , Masuyama Toshiya , Tanaka Satonori , Nakajima Hiroo , Kurokawa Nobuo , Isa Yukio
Published: August 2005

The carcinogenicity of sublimed urethane (ethyl carbamate) in air was examined with mice. JCL:ICR mice were nursed in a plastic cage inside a vinyl chamber which was ventilated 4 times per hour. The mice were exposed to urethane gas for various periods by passing air which contained a high concentration of sublimed urethane (1.29 μg/ml) into the vinyl chamber, or by placing a vessel containing crystalline urethane inside the vinyl chamber so that it was filled with spontaneously‐sublimed urethane gas at a low concentration (0.25 μg/ml). When female mice were killed 5 months after exposure, lung tumor frequency increased almost linearly with the number of days of exposure in the low concentration experiment, but increased in a non‐linear manner in the high concentration experiment. In terms of nearly the same total dose, i.e., (concentration of urethane gas in air) × (days of inhalation), one day of exposure to urethane gas at the low concentration induced lung tumors at a significantly higher frequency than 1/4 day of exposure to urethane gas at the high concentration. When male mice were killed at 12 months after exposure to examine the progressive change of induced tumors, malignant, invasive and metastatic tumors were found to have been induced more frequently in the lung after exposure to urethane gas at the low concentration (0.25 μg/ml for 10 days) than at the high concentration (1.29 μg/ml for 4 days), although the total dose in the former group was about half of that in the latter. Continuous exposure to urethane gas for a longer period at the low concentration seems to be more efficient for the induction, promotion and/or progression of lung tumors than the exposure for a shorter period at the high concentration.
In vitro Transformation of BALB/c 3T3 Cells by 1,1,2,2‐Tetrachloroethane
Authors: Colacci Annamaria , Perocco Paolo , Vaccari Monica , Mazzullo Mario , Albini Adriana , Parodi Silvio , Taningher Maurizio , Grilli Sandro
Published: August 2005

1,1,2,2‐Tetrachloroethane (1,1,2,2‐TTCE) was shown to be capable of inducing in vitro transformation of BALB/c 3T3 cells (clone A‐31) either in the presence or in the absence of S9 activating system using an amplification‐transformation (level‐II) assay by reseeding confluent cells from each treatment and allowing additional rounds of cell replication. In the absence of metabolic activation, the highest assayed dose (1000 μg/ml), exerting the highest toxicity, was the only transforming dose. Lower doses of 1,1,2,2‐TTCE were capable of transforming BALB/c cells in the presence of S9 activating system, the dose of 500 μg/ml exerting the highest transforming activity. The number and size of transformed foci recognized in the level‐II plates were a function of the number of cells reseeded in the amplification assay. Foci obtained in the presence of S9 activating systems were larger in size, more deeply basophilic, and exhibited denser multilayering of constituent cells than foci recognized in the absence of exogenous metabolic activation.
Induction of Growth Factor‐receptor and Metalloproteinase Genes by Epidermal Growth Factor and/or Transforming Growth Factor‐α in Human Gastric Carcinoma Cell Line MKN‐28
Authors: Yoshida Kazuhiro , Tsujino Tetsuhiro , Yasui Wataru , Kameda Takashi , Sano Toshiaki , Nakayama Hirofumi , Toge Tetsuya , Tahara Eiichi
Published: August 2005

We examined the effects of epidermal growth factor (EGF) and transforming growth factor‐α (TGF‐α) on EGF receptor (EGFR) phosphorylation and the expression of mRNAs for oncogenes, growth factors, their receptors and metalloproteinase genes by MKN‐28 gastric carcinoma cells which express EGF, TGF‐α and EGFR genes. Both EGF and TGF‐α stimulated EGFR phosphorylation. EGF and TGF‐α induced FOS, MYC and ERBB‐2 oncogene expression. Interestingly, EGF increased the expression of mRNAs for TGF‐α and EGFR. On the other hand, TGF‐α increased TGF‐α mRNA but decreased the expression of mRNAs for EGFR and TGF‐β. Furthermore, mRNAs for interstitial collagenase, stromelysin and procollagen type I genes were also enhanced after treatment with EGF and TGF‐α. These results indicate that EGF and TGF‐α successively evoke cascade phenomena which favor tumor progression, invasion and extracellular matrix formation, acting as autocrine growth regulators for gastric carcinomas.
Transformation‐specific Decrease of Phosphorylation of 80K Protein, a Substrate of Protein Kinase C, in NIH3T3 Cells
Authors: Oh‐uchida Mamoru , Yano Kazumi , Kawamoto Shoko , Shimizu Kenji
Published: August 2005

Phosphorylation in normal and transformed NIH3T3 cells of the 80K protein, a specific substrate for protein kinase C, was compared by means of two‐dimensional gel analysis. We obtained evidence that NIH3T3 cells transformed by the c‐raf or H‐ras oncogene maintained a decreased level of phosphorylation of the 80K protein, with or without phorbol ester (TPA)‐stimulation, at all concentrations of serum tested while normal NIH3T3 cells maintained an elevated level of phosphorylation of the 80K protein. Furthermore, NIH3T3 cells transformed by N‐ras, K‐ras, src, mos or polyoma middle T antigen exhibited a decreased level of phosphorylation of the 80K protein. These events were confirmed by an analysis of a hormone‐inducible H‐ras transformant. Thus, phosphorylation of the 80K protein is inversely correlated with cellular transformation.
Inhibition of Proliferation and Induction of Differentiation of Human and Mouse Myeloid Leukemia Cells by New Ethyleneglycol‐type Nonphosphorus Alkyl Ether Lipids
Authors: Kasukabe Takashi , Honma Yoshio , Hozumi Motoo , Nomura Hiroaki
Published: August 2005

A variety of ethyleneglycol‐type nonphosphorus alkyl ether lipids, ether derivatives of diethylene‐glycol in which the two hydroxyl groups were substituted with long chain alkyl and quaternary ammonioalkyl groups, were synthesized and their effects on proliferation and differentiation of cultured human (HL‐60) and mouse (M1) myeloid leukemia cells were studied. Incubation with these compounds inhibited the cellular proliferation, and the cells differentiated into morphologically and functionally mature granulocytes. Of the compounds tested, 1‐[2‐[2‐(octadecyloxy)ethoxy]ethoxy]‐butylpyridinium mesylate (EG‐6) was the most effective in inducing differentiation of HL‐60 cells. Almost maximal induction of differentiation and inhibition of growth of HL‐60 cells on day 6 were observed when the cells were treated with EG‐6 for 1 day and then cultured without EG‐6 for a further 5 days. The inhibitory effect of EG‐6 on the leukemic cells was over 100 times more than that of 2‐[2‐(dodecyloxy)ethoxy]ethyl 2‐pyridinioethyl phosphate, a potent antileukemic ether phospholipid.
Cancer and Other Causes of Death among Koreans in Fukuoka, Japan, 1976–1986
Authors: Shinohara Shiro , Kono Suminori , Ahn Yoon‐Ok , Shigematsu Takao
Published: August 2005

Mortalities from cancer and other causes among Koreans living in Fukuoka, Japan, between 1976 and 1986 were examined as compared with those of Japanese in the prefecture. Korean males had a marked excess in all‐cause mortality, while the excess among females was less prominent. In both sexes, mortalities from liver cancer, liver cirrhosis, accident and suicide were markedly increased in the Korean population. These findings are in agreement with those observed among Koreans in Osaka. Although 20–30% lower‐than‐Japanese mortality from stomach cancer has been reported for Koreans in Osaka, those in Fukuoka had a risk of this cancer comparable to that of Japanese. A life‐style survey of Koreans in Japan might provide a better understanding of the disease patterns observed in this population.
Identification of HTLV‐I Sequence in Cord Blood Mononuclear Cells of Neonates Born to HTLV‐I Antigen/Antibody‐positive Mothers by Polymerase Chain Reaction
Authors: Saito Shigeru , Furuki Kazuhiko , Ando Yoshiya , Tanigawa Takuo , Kakimoto Kazuhiko , Moriyama Ikuko , Ichijo Motohiko
Published: August 2005

We developed a polymerase chain reaction (PCR) method which has high sensitivity and simple technique in order to investigate the presence or absence of human T lymphotropic virus type I (HTLV‐I) provirus in cord blood mononuclear cells of neonates born to HTLV‐I carrier mothers. Out of 40, three subjects were found to contain the HTLV‐I provirus genome. These three subjects remained HTLV‐I sequence‐positive in follow‐up study. On the other hand, when examined by a conventional technique for detection of HTLV‐I‐associated antigen on peripheral mononuclear cells, all 40 neonates were HTLV‐I‐associated antigen‐negative. These results suggest that PCR is more sensitive than the conventional antigen detection method and is useful in early detection of HTLV‐I infection in neonates born to HTLV‐I carriers.
Interleukin‐2 Receptor β‐Chain (p70–75) Expressed on Leukemic Cells from Adult T Cell Leukemia Patients
Authors: Kodaka Taiichi , Uchiyama Takashi , Ishikawa Takayuki , Kamio Masanori , Onishi Rie , Itoh Katsuhiko , Hori Toshiyuki , Uchino Haruto , Tsudo Mitsuru , Araki Koichi
Published: August 2005

To determine whether the interleukin‐2 receptor (IL‐2R) β‐chain (p70–75) is expressed on lenkemic cells from patients with adult T cell leukemia (ATL) as well as α‐chain (p55, Tac), we performed radiolabeled interleukin‐2 (IL‐2) binding assay, chemical crosslinking of radiolabeled IL‐2 and flow cytometric analysis using a newly‐developed anti‐IL‐2R β‐chain antibody. The results showed that leukemic cells from all the 12 ATL patients we examined expressed the IL‐2R β‐chain together with the α‐chain, whereas there was no detectable β‐chain expression on unstimulated peripheral blood CD4(+) T cells from healthy volunteers. Southern blot analysis revealed that this abnormal expression was not caused by the structural change of IL‐2R β‐chain gene. Though leukemic cells from all ATL patients examined expressed high‐affinity IL‐2Rs, leukemic cells from only 25% of all ATL patients proliferated in response to IL‐2. These results showing abnormal expression of IL‐2R β‐chain on leukemic cells from ATL patients (ATL cells) suggest a close association between HTLV‐I infection and abnormal β‐chain expression as well as α‐chain expression.
Purification and Characterization of Tumor Invasion‐inhibiting Factors
Authors: Isoai Atsushi , Giga‐Hama Yuko , Shinkai Kiyoko , Mukai Mutsuko , Akedo Hitoshi , Kumagai Hiromichi
Published: August 2005

Tumor invasion‐inhibiting factors were purified from bovine liver using an in vitro system for estimating the tumor invasion ability. The acid‐ethanol extract of liver was subjected to ultrafiltration (Amicon PM10 membrane), and the fraction corresponding to the molecular weight range below 10,000 was further fractionated by ion‐exchange (DEAE‐Toyopearl), gel filtration (Bio‐Gel P6), and reverse‐phase (C18) chromatographies. Two types of active polypeptides with molecular weights of about 5,000 and 2,000 were purified and named IIF‐1 and IIF‐2, respectively. Both peptides inhibited tumor invasion with half‐maximum concentrations of 2–6 ng/ml in vitro. The amino acid compositions of both peptides were determined.
Correlation between the Presence of Microvilli and the Growth or Metastatic Potential of Tumor Cells
Authors: Ren Jin , Hamada Jun‐ichi , Okada Futoshi , Takeichi Noritoshi , Morikawa Kiyoshi , Hosokawa Masuo , Kobayashi Hiroshi
Published: August 2005

We used an electron microscope to examine microvilli which appear on the surfaces of various tumor cells with high or low growth potential and/or metastatic ability. The results show that a greater number of microvilli appeared on the surfaces of tumor cells (QRpP and ERpP) which possess high growth potential than on tumor cells (QR and ER) with low growth potential. We also observed that microvilli were more abundant on the surface of highly metastatic clone cells, i.e. c‐SST‐2 (cl‐2), mouse B16 melanoma (F‐10) and human colon carcinoma (KM12SM) than on weakly metastatic clone cells, c‐SST‐2 (cl‐4‐2), B16 (F‐1) and (KM12C). At the same time, more microvilli were observed on the surface of B16 BL6 cells, which were obtained from the metastatic site of the B16 F10 cells, than on the surface of the parent B16 F10 cells. Immunoelectron microscopy revealed that the c‐neu oncogene product, which is closely related to an epidermal growth factor receptor, was positively stained in the microvilli of tumor cells (ERpP) with high growth potential and high metastatic ability, whereas the tumor cells (ER) with low growth potential and weak metastatic ability were not stained. These findings suggest that the increased presence of microvilli correlates closely with the growth potential and metastatic ability of tumor cells.
The Heterogeneity of Target Recognition by Lymphokine‐activated Killer Precursor Cells
Authors: Ibayashi Yukihiro , Gray J. Dixon , Golub Sidney H. , Daibo Masahiko , Yamaki Toshiaki , Kawahara Takahisa , Kubota Tsukasa , Hashi Kazuo
Published: August 2005

Lymphokine‐activated killer (LAK) cells were generated from peripheral blood lymphocytes (PBL) that were depleted of mature cytotoxic natural killer (NK) cells. PBL NK activity was abolished by pretreatment of effector cells with the toxic lysosomotropic agent l‐leucine methyl ester (LME) or by depletion of effector cells by K562 monolayer absorption (MA). Both treatments markedly reduced the proportion of cells expressing NK‐associated markers such as CD 16 (Leu 11b, B73.1), Leu 7, and NKH‐1 (Leu 19), whereas these treatments had minimal effects on cells expressing T cell markers (CD 3, CD 4, and CD 8). LME and MA also drastically decreased the proportion of K562 target‐binding lymphocytes. LAK activity against NK‐sensitive and NK‐resistant targets can be generated from the NK cell‐depleted PBL by incubation with interleukin‐2. Peak LAK activity generated from MA‐treated PBL was later than the peak of LAK activity generated from either untreated or LME‐treated PBL. Although MA of PBL on NK‐resistant S4 sarcoma targets had little effect on NK activity, LAK activity against both K562 and S4 targets was reduced. These results suggest that there are at least three LAK precursor subpopulations in PBL: mature NK cells that can bind and kill K562 targets (LME‐sensitive and MA‐sensitive); “pre‐NK”cells that can bind but cannot kill (LME‐resistant and MA‐sensitive); and non‐NK cells that cannot bind and cannot kill K562 targets (MA‐resistant).
Frequent Detection of Hepatitis C Virus US Strain in Japanese Hemophiliacs
Authors: Hijikata Makoto , Kato Nobuyuki , Mori Shigehisa , Ootsuyama Yuko , Nakagawa Masanori , Sugimura Takashi , Ohkoshi Showgo , Kojima Hideo , Meguro Takashi , Taki Masashi , Takayama Shigenobu , Yamada Kaneo , Shimotohno Kunitada
Published: August 2005

Hemophiliacs have been found to be at high risk of hepatitis. Hemophiliacs in Japan receive imported clotting factors as well as domestic ones. Recently we found that hepatitis C virus (HCV) could be classified into at least two types, HCV‐US and HCV‐J, depending on the nucleotide sequence. We analyzed the nucleotide sequences of virus RNAs from the plasma of patients with hemophilia A or B and found HCV‐US in 3 of 4 Japanese hemophiliacs examined.
Geographical Distribution of Subjects Seropositive for Human T‐Cell Leukemia Virus Type 1 in Papua New Guinea
Authors: Imai Joko , Terashi Shin‐ichi , Talonu Tom , Komoda Haruko , Taufa Tukutau , Nurse George T. , Babona Diro , Yamaguchi Koichi , Nakashima Hiroaki , Ishikawa Koh‐ichi , Kawamura Meiko , Hayami Masanori
Published: August 2005

Of 1471 sera collected from 1986 to 1989 in Papua New Guinea (PNG), 2.2% were found to be positive for anti‐HTLV‐1 antibody by successive particle agglutination and immunofluorescence tests. The seropositive rate varied in different provinces and was higher in the coastal areas of the main island and in neighboring small islands than in the highlands of PNG. The frequency of HTLV‐1 infection of children was higher, but the age‐dependent increase in antibody positivity, generally observed in other HTLV‐1 endemic areas of the world, was not clear in PNG. No difference was observed in antibody prevalence in males and females in this study.
Species Difference among Experimental Rodents in the Activity and Induction of Cytochrome P‐450 Isozymes for Mutagenic Activation of Carcinogenic Aromatic Amines
Authors: Degawa Masakuni , Agatsuma Toshinori , Hashimoto Yoshiyuki
Published: August 2005

The expressions of hepatic microsomal cytochrome P‐450 isozymes in male rats, mice, hamsters and guinea pigs were studied comparatively with or without an ip injection of a cytochrome P‐450 inducer. The activity and quantity of microsomal cytochrome P‐450 isozymes were determined respectively by a bacterial mutation assay with Salmonella typhimurium TA98 and immunochemical assays using monoclonal antibodies against rat cytochrome P‐450 isozymes. 3‐Methoxy‐4‐aminoazobenzene (3‐MeO‐AAB), 2‐amino‐3‐methyl‐9H‐pyrido[2,3‐b]indole acetate (MeAαC) and 3‐methylcholanthrene were used as cytochrome P‐450 inducers, and 7 carcinogenic aromatic amines including 3‐MeO‐AAB and MeAαC were used as substrates for the mutation assay. By means of these assays, we examined the species differences among rodents in the activity and induction rate of hepatic cytochrome P‐450 isozymes responsible for the mutagenic activation of carcinogenic aromatic amines.
Correlation of Tissue‐specific Methylation with Gene Inactivity in Hepatitis B Virus Transgenic Mice
Authors: Araki Kimi , Akagi Kiwamu , Miyazaki Jun‐ichi , Matsubara Kenichi , Yamamura Ken‐ichi
Published: August 2005

We produced transgenic mice using two constructs, HB‐GII and 1.2HB‐BS, of hepatitis B virus (HBV) DNA. The former has been designed to express mRNAs for HBV surface antigen (HBsAg), and the later to express all mRNAs of HBV. Several lines of the transgenic mice carrying each construct were examined for the tissue‐specificity and level of HBV DNA expression, and for the relationship between expression and methylation of the transgenes. Only one out of ten for HB‐GII and one out of eight for 1.2HB‐BS were high producers of viral antigens. In high producers, transgenes were expressed in the liver and the kidneys. But in low producers, transgenes were usually expressed only in the kidneys. There is a reciprocal relationship between the level of expression and the degree of methylation, that is, the higher the level of expression, the less the degree of methylation. We also observed that the expression of the integrated HBV‐DNA was repressed by methylation following its passage through the female germline in one line. Thus, in addition to transacting factors that can control the gene expression positively or negatively, this tissue‐specific methylation may also be involved in the regulation of HBV gene expression.
Inhibitory Effects of Acyclic Retinoid (Polyprenoic Acid) and Its Hydroxy Derivative on Cell Growth and on Secretion of α‐Fetoprotein in Human Hepatoma‐derived Cell Line (PLC/PRF/5)
Authors: Fukutomi Yasushi , Omori Masahide , Muto Yasutoshi , Ninomiya Mitsuo , Okuno Masataka , Moriwaki Hisataka
Published: August 2005

Acyclic retinoid (polyprenoic acid) has a slightly different structure from retinoic acid. However, acyclic retinoid acts similarly to retinoic acid, because both bind to cellular retinoic acid‐binding protein and cellular retinoid‐binding protein, F‐type, with the same strong binding affinity. We studied the effects of acyclic retinoid, the 7‐hydroxy derivative of acyclic retinoid (7OH‐acyclic retinoid) and retinoic acid on a human hepatoma‐derived cell line PLC/PRF/5 (Alexander cells). Acyclic retinoid inhibited cell growth with an ID50 value of 14 μM, and reduced cell viability with an LD50 value of 86 μM. The ratios of LD50 value to ID50 value were 6.1 for acyclic retinoid, 2.4 for 7OH‐acyclic retinoid and 1.4 for all‐trans‐retinoic acid. Taking this ratio as a parameter of relative cytotoxicity, we concluded that acyclic retinoid is the least toxic compound. Growth inhibition of cells by acyclic retinoid was associated with the incorporation of 3H‐thymidine in the logarithmic phase. Acyclic retinoid reduced secretion of α‐fetoprotein (AFP) and reciprocally increased secretion of albumin in the culture media, suggesting that acyclic retinoid influences gene expression of these proteins. Thus, acyclic retinoid, one of the less toxic retinoids, inhibits cell growth of human cancer cell line PLC/PRF/5 and appears to alter gene expression of AFP and albumin toward a “normal’direction.
Massive Sero–epidemiological Survey of Hepatitis C Virus: Clustering of Carriers on the Southwest Coast of Tsushima, Japan
Authors: Ito Shin‐Ichiro , Ito Mizuko , Cho Myung‐Je , Shimotohno Kunitada , Tajima Kazuo
Published: August 2005

We conducted a mass screening survey for anti–hepatitis C virus antibody (anti–HCV–Ab) among 1,009 inhabitants, 341 males and 668 females, older than 40 years, in south Tsushima in 1989. The overall positive rate for anti–HCV–Ab was 2.3% (2.9% in males and 1.9% in females). The positive rate for anti–HCV–Ab among people with histories of blood transfusions was 14.8% (8/54), which was higher than that (1.6%, 15/955) in people without blood transfusions (P < 0.001). The positive rate (15.1%, 8/53) in people with an elevated level of glutamic oxalacetic transaminase (GOT, >41 U/ liter) or glutamic pyruvic transaminase (GPT, >36 U/liter) was significantly higher than that (1.6%, 15/956) for people with normal values of GOT and GPT (P < 0.001). The most interesting finding was that the anti–HCV–Ab positives without histories of blood transfusions were clustered in a few villages located in the southwestern coastal areas of Tsushima, where the positive rate of 3.7% (13/355) was significantly higher (P < 0.001) than that of 0.3% (2/600) in other villages.
Detection of Epidermal Growth Factor Receptors and E‐Cadherins in the Basolateral Membrane of A431 Cells by Laser Scanning Fluorescence Microscopy
Authors: Fukuyama Ryuichi , Shimizu Nobuyoshi
Published: August 2005

We have examined the localization of epidermal growth factor (EGF) receptors and E‐cadherins in cultured A431 cells, an epidermoid carcinoma cell line, using a laser scanning fluorescence microscope. The fluorescence signals generated by monoclonal antihodies against EGF receptor and E‐cadherin were localized mainly in the cell‐cell contact sites, about 3 μm in width. When these areas for cell adhesion were scanned perpendicularly, fluorescence was detected from a point 4μ from the cell base for a distance of 8 μm towards the cell surface (about 16 μm from the cell base). These data suggest the subcellular localization of EGF receptors and E‐cadherins in the basolateral membrane of A431 cells.
A Pulmonary Large Cell Carcinoma Cell Line Expressing Neuroendocrine Cell Markers and Human Chorionic Gonadotropin α‐Subunit
Authors: Kasai Kiyoshi , Kameya Toru , Kadoya Kuniko , Wada Chieki
Published: August 2005

A cell line producing the neuroendocrine cell surface antigen and human chorionic gonadotropin (hCG) α‐subunit, designated as KTA7, was established from human large cell carcinoma using a serum‐free medium, ACL‐3. KTA7 continued to grow in the ACL‐3 medium, showing the morphological characteristics of large cell undifferentiated carcinoma. The KTA7 cells reacted with antibodies such as 6H7 and MOC1 directed against the cell surface antigens and PGF9.5 directed against a cytoplasmic protein of neuroendocrine cells but did not possess either most epithelial markers other than low‐molecular‐weight keratin (Cytokeratin) or neuron‐specific enolase. The KTA7 cells, by immunostaining with anti‐hCG subunit antibodies, were shown to produce hCG α‐ but not β‐subunit, Northern blot analysis showed KTA7 RNA to synthesize hCG α‐subunit mRNA but not that of the hCG β‐subunit. Thus, the hCG α‐subunit alone was independently expressed in KTA7. Chromosome analysis showed loss of alleles of chromosome 3p and 17 in KTA7 cells but not loss of 13q. KTA7 was considered to be derived from large cell undifferentiated carcinoma with neuroendocrine differentiation (large cell neuroendocrine tumor) and thus may fine use in studies on the pathobiology of large cell‐type neuroendocrine tumors since it expresses at the same time marker substances of neuroendocrine differentiation and the hCG α‐subunit.
Relation between Estrogen Receptor and Malignancy of Thyroid Cancer
Authors: Takeichi Nobuo , Ito Hisao , Haruta Rumi , Matsuyama Toshiya , Dohi Kiyohiko , Eiichi Eiichi
Published: August 2005

The relationship between the histological grade of dedifferentiation of thyroid cancer and estrogen receptors (ER) was examined immunohistochemically. Thyroid cancers were from postmenopausal females of almost the same mean age (69‐73 years old) and within the same period of time (1974–1983). ER immunoreactivity located in the nucleus of the epithelium was found in all 6 well differentiated papillary cancers, and 5 of them (83.3%) showed ER‐immunoreactive (ER‐IR) cells amounting to 20 or more per visual field (x 100) under a light microscope. Of the 6 cases of poorly differentiated papillary cancer, 5 (83.3%) had 1‐19 ER‐IR cells per visual field. ER‐IR cells were negative in 5 out of 6 cases (83.3%) of anaplastic cancers. Thus, the number of ER‐IR cells tended to decrease with the degree of atypism of thyroid cancer (P < 0.001).
bcl‐2 Translocation in Japanese B Cell Lyraphoma: Novel bcl‐2 Translocation with Immunoglobulin Heavy Chain Diversity Segment
Authors: Seto Masao , Osada Hirotaka , Ueda Ryuzo , Ito Chie , Iwaki Osamu , Oyama Atushi , Suchi Taizan , Toshitada Toshitada
Published: August 2005

Breakpoints of a lymphoma case with bcl‐2 gene rearrangement that did not show comigration of immunoglobulin (Ig) heavy chain joining (JH) fragment were cloned. Sequence analysis revealed that the translocation broke the 3 side of the Ig heavy chain diversity (DH) segment at the heptamer recombination signal and each end was ligated to the bcl‐2 locus. Since Southern blot demonstrated that both alleles of JH were rearranged, this translocation was suggested to have occurred at the step of VH‐DH, or DH‐DHJH recombination, one step later than that of DH‐Jn recombination where the common pattern of bcl‐2 rearrangement generally occurs. Cases that showed comigration with JH fragment were also studied by polymerase chain reaction with 5’bcl‐2 oligomer and 3 JH consensus anti‐sense oligomer since it has been demonstrated that bcl‐2 translocation at the major breakpoint clustering region (mbr) in American cases clusters within an about 150 bp region in the mbr. The results demonstrated that four out of five cases studied were amplified, indicating that the same clustering mechanism exists for Japanese cases. The present study, together with our previous report on Igt‐bcl‐2, indicated that bcl‐2 translocation in Japanese B cell lymphomas might occur at a later stage of B cell development, as compared with that in American cases. Less involvement of bcl‐2 in Japanese B cell lymphoma may also he in part explainable by low susceptibility to bcl‐2 rearrangement at the step of DH‐JH recombination.
Mechanism of Metabolic Abnormality of Thyroid Hormones in Walker 256 Carcinosarcoma‐bearing Rats
Authors: Murayama‐Oda Kikuno , Imamura Kiichi , Kim Hee‐Kyoung , Takehiko Takehiko
Published: August 2005

We examined the mechanism of abnormality of thyroid hormone metabolism in Walker 256 carcino‐sarcoma‐bearing rats. The serum levels of thyroxine (T4), 3,5,3′‐triiodothyronine (T3) and thyroid‐stimulating hormone (TSH), and the responses of serum T4 and T3 to exogenous TSH in tumor‐bearing rats on day 14 after inoculation of tumor cells were significantly less than those in pair‐fed control (PFC) rats, suggesting that the metabolic abnormality of thyroid hormones may be caused by disorder of both peripheral and central functions, and that a certain tumor‐derived factor may be involved in this abnormality. An active factor responsible for the metabolic abnormality was found in soluble cytosol fraction (SF) of the tumor cells. Administration of the SF to normal rats significantly reduced their serum T4 and T3 concentrations, liver 5 ‐deiodinase (5′‐DI) activity, responsiveness of the thyroid gland to TSH and food intake compared with those of PFC rats, but, unlike the tumor, did not reduce the serum TSH level. This biologically active factor in the SF was found to be a heat‐labile protein and specific to the tumor. It was tentatively named serum thyroid hormone reducing factor (STRF). STRF was partially purified from the SF by ammonium sulfate fractionation and DEAE‐cellulose chromatography. Partially purified STRF preparation significantly diminished the serum T4 and T3 concentrations and liver S′‐DI activity and food intake of normal rats compared with those of PFC rats, mimicking the changes associated with the tumor in tumor‐bearing animals. These results suggested that abnormality of thyroid hormone metabolism in tumor‐bearing animals may partly be caused by STRF‐mediated modulation at peripheral and thyroid gland levels. Whether STRF actually induces anorexia remains to he clarified.
Novel Mechanism of N‐Solanesyl‐N,N′‐bis(3,4‐dimethoxybenzyl)ethylenediamine in Potentiation of Antitumor Drug Action on Multidrug‐resistant and Sensitive Chinese Hamster Cells
Authors: Tomida Akihiro , Tatsuta Tohru , Suzuki Hideo
Published: August 2005

The mechanism of the synthetic isopremoid N‐solanesyl‐N,N′‐bis(3,4‐dimethoxybenzyl)ethylenediantine (SDB‐ethylenediamine) in potentiating antitumor drug action against multidrug‐resistant cells was comparatively studied with other potentiators such as verapamil and cepharanthine. SDB‐ethylenediamine increased the accumulation of [3H]daunorubicin (DNR) in Chinese hamster V79 (V79/S) and its multidrug‐resistant mutant (V79/ADM) cells. Even after SDB‐ethylenediamine was removed from the medium, its effect continued. But when verapamil was removed from the medium, its effect disappeared immediately. Unlike verapamil and cepharanthine, SDB‐ethylenediamine did not greatly inhibit the efflux of [3H]DNR from V79/ADM, the binding of [3H]vinblastine to membrane vesicles of V79/ADM, or the binding of [3H]azidopine to P‐glycoprotein in the cytoplasmic membrane of V79/ADM. It did stimulate the influx of [3H]DNR into the ATP‐depleted cells of V79/S and V79/ADM. Thus, SDB‐ethylenediamine uniquely potentiates antitumor drugs. The increased intracellular accumulation of antitumor drugs in the presence of SDB‐ethylenediamine is due not only to the inhibition of active efflux but also to the stimulation of the influx of antitumor drugs.
Promotion of Rat Hepatocarcinogenesis by Praziquantel
Authors: Shirai Tomoyuki , Joong Kim Dae , Hakoi Kazuo , Thamavit Witaya , Pairojkul Chawalit , Hoshiya Toru , Hasegawa Ryohei , Ito Nobuyuki
Published: August 2005

Praziquantel, the widely used anti‐helminthic agent, was investigated for hepatocarcinogenesis‐promoting potential using a medium‐term liver bioassay system for carcinogens. F344 male rats were given a single intraperitoneal injection of diethylnitrosamine (DEN, 200 mg/kg) and then starting 2 weeks later, received praziquantel in the diet at concentrations of 1.5 or 0.5%, or intragastrically at a dose of 1,500 mg/kg once a week for 6 weeks. Control groups received DEN or praziquantel alone. All rats were subjected to two‐thirds partial hepatectomy at week 3 and killed at week 8. Development of glutathione 5‐transferase placental form‐positive foci in the liver was significantly increased in terms of both number and area with the 1.5% dose, while only area was affected by the 0.5% dose. The results thus indicate that praziquantel at high dose has promoting potential in rat hepatocytic tumorigenesis.
Loss of Heterozygosity on Chromosome 1p in Thyroid Adenoma and Medullary Carcinoma, but not in Papillary Carcinoma
Authors: Kubo Katsuyuki , Yoshimoto Katsuhiko , Yokogoshi Yutaka , Tsuyuguchi Masaru , Shiro Shiro
Published: August 2005

We analyzed 53 loci on 21 chromosomes other than chromosome 4 to detect possible loss of heterozygosity in 31 thyroid tumors using polymorphic DNA markers that detect allelic deletions at specific chromosomal loci. Loss of heterozygosity on chromosomes 1, 7 and 12 was detected in one follicular thyroid adenoma, and on chromosome 1 in two medullary thyroid carcinomas. However, no loss of heterozygosity was detected at any of the loci examined in papillary thyroid carcinomas. These results suggest that chromosomal loss detected in thyroid adenoma is one of the signals for risk of premalignant transformation, and that inactivation of unknown genes on chromosome 1p contributes to tumorigenesis of medullary thyroid carcinoma. Some genetic changes other than chromosomal losses may participate in the tumorigenesis of papillary thyroid carcinoma.
Inhibitory Effect of Fibronectin and Its Recombinant Polypeptides on the Adhesion of Metastatic Melanoma Cells to Laminin
Authors: Saiki Ikuo , Makabe Takashi , Yoneda Junya , Murata Jun , Ishizaki Yukuo , Kimizuka Fusao , Kato Ikunoshin , Azuma Ichiro
Published: August 2005

We have utilized recombinant fibronectin fragments with cell‐binding domain (C‐274), heparin‐bind‐ing domain (H‐271) or CS1 peptide in type III connecting segment (IIICS) and their fusion polypeptides such as CH‐296 (containing C‐274, H‐271 and CS1), CH‐271 (containing C‐274 and H‐271) and C‐CS1 (containing C‐274 and CS1) to investigate the mechanism of the fibronectin‐mediated inhibitory effect on tumor cell adhesion to laminin as well as fibronectin. These fragments retained cell adhesion‐promoting and/or heparin‐binding properties when they were immobilized on a surface. Pretreatment of tumor cells with CH‐296 or CH‐271 suppressed cell adhesion to both laminin and fibronectin. H‐271 at the high concentration of 500 μg/ml slightly inhibited cell adhesion to laminin (but not to fibronectin), whereas C‐274, C‐CS1 or a mixture of C‐274, H‐271 and CS1 (similar molar ratio to CH‐296) inhibited cell adhesion to fibronectin but not to laminin. On the other hand, tumor cell adhesion to laminin‐substrate was also inhibited by heparin or heparan sulfate, which were able to bind to laminin, suggesting that heparin‐like molecules on the cell surface may be included among the laminin receptors. These results indicated that the co‐presence of cell‐ and heparin‐binding domains of fibronectin may be required for the fibronectin‐mediated inhibitory effect on tumor cell adhesion to laminin, and that the interaction of the heparin‐binding domain of fibronectin with the cell surface leads to the inhibition of the cell adhesion to laminin.
Recombinant Fusion Polypeptide with Cell‐ and Heparin‐binding Domains of Fibronectin Inhibits Liver Metastasis of L5178Y‐ML25 Lymphoma Cells
Authors: Saiki Ikuo , Matsumoto Yoshihiro , Murata Jun , Makabe Takashi , Yoneda Junya , Okuyama Harue , Kimizuka Fusao , Ishizaki Yukuo , Kato Ikunoshin , Azuma Ichiro
Published: August 2005

We have investigated the effect of recombinant polypeptides with cell‐binding domain (C‐274) or with heparin‐binding domain (H‐271) and their fusion polypeptide (CH‐271) on liver metastasis of murine lymphoid tumor. The polypeptides containing heparin‐binding domain, H‐271 and CH‐271, were able to inhibit liver metastasis when co‐injected i.v. with L5178Y‐ML25 T‐lymplioma cells, while C‐274 with cell‐binding domain showed much weaker antimetastatic activity. Treatment with H‐271 or CH‐271 substantially prolonged the survival time of mice injected i.v. with L5178Y‐ML25 cells. CH‐271, containing cell‐ and heparin‐binding domains, was more antimetastatic than H‐271. The reason why CH‐271 was more effective in inhibiting liver metastasis than H‐271 can not be explained in terms of a difference in the stability in the circulation or in the molecular size of the polypeptide. The polypeptides used in this study did not affect the tumor cell growth or viability in vitro. CH‐271 was found to be still active in inhibiting liver metastasis even when natural killer cells or macrophages were removed from this system. Furthermore, multiple administrations of CH‐271 after tumor implantation effectively inhibited liver metastasis and enhanced the survival rate as compared with H‐271, C‐274 and untreated control. Thus, the fusion of H‐271 with C‐274 (i.e. CH‐271) augments the antimetastatic property of H‐271, possibly through the interaction between tumor cells and the heparin‐binding domain of fibronectin.
Inhibitory Effect of Antimetastatic Fusion Polypeptide of Human Fibronectin on Tumor Cell Adhesion to Extracellular Matrices
Authors: Matsutnoto Yoshihiro , Saiki Ikuo , Makabe Takashi , Yoneda Junya , Murata Jun , Kimizuka Fusao , Ishizaki Yukuo , Kato Ikunoshin , Azuma Ichiro
Published: August 2005

We investigated the inhibitory mechanism of liver metastasis by using recombinant fragments with cell‐ and/or heparin‐binding domains (C‐274, H‐271 or the fusion fragment CH‐271). Intravenous co‐injection of L5178Y‐ML25 cells with CH‐271 was more effective for the inhibition of liver metastasis than C‐274, H‐271 or C‐274+H‐271. Reduction of the arrest and retention of the radiolabeled tumor cells in the liver of mice was found when CH‐271 was co‐injected with tumor cells. L5178Y‐ML25 cells adhered both concentration‐ and time‐dependently to the substrates precoated with fibronetin, laminin and reconstituted basement membrane, Matrigel. The tumor cell adhesions to the substrates were inhibited in the presence of CH‐271. The tumor cell interaction with CH‐271‐substrate was inhibited by heparin, and monoclonal antibodies (IST‐1 or IST‐2) against the heparin‐binding domain of fibronectin. However, monoclonal antibodies against the cell‐binding domain failed to block the interaction. Similarly, CH‐271‐mediated antimetastatic activity was also inhibited by the treatment of CH‐271 with IST‐1 before the co‐injection with tumor cells, whereas monoclonal antibody against the cell‐binding domain had no effect. Thus, the antimetastatic effect of CH‐271 fusion fragment on liver metastasis of L5178Y‐ML25 cells may be partly due to interference with the adhesive interaction of tumor cells with extracellular matrix or basement membrane components by a heparin‐binding domain‐dependent mechanism.
Comparative Pharmacokinetic Properties of Murine Monoclonal Antibody A7 Modified with Neocarzinostatin, Dextran and Polyethylene Glycol
Authors: Takashina Ken‐ichiro , Kitamura Kazuya , Yamaguchi Toshiharu , Noguchi Akinori , Noguchi Akira , Tsurumi Hiroshi , Toshio Toshio
Published: August 2005

The murinc monoclonal antibody A7 (Mab A7) was chemically modified with several macromolecnles: dextran, polyethylene glycol and the anti‐cancer polypeptide neocarzinostatin. The pharmacokinetic properties of the combinations were subsequently examined. Radioimmunoassay revealed that all preparations retained their antigen‐binding activities. The Mab A7‐neocarzinostatin conjugate was cleared from the blood circulation with a kinetic pattern almost identical to that of the parent Mab A7. Of the three preparations, Mab A7‐dextran (A7‐Dx) was removed the most rapidly from the circulation. Mab A7‐polyethylene glycol (A7‐PEG) exhibited the slowest blood clearance curve, with twice the half life of the parent Mab A7 in the circulation. In normal organ distributions, A7‐Dx exhibited the highest liver, spleen and kidney uptake, and A7‐PEG showed the lowest uptake, when expressed as tissue:blood ratio. Although A7‐Dx exhibited lower tumor uptake, there was no significant difference among the three conjugates in tumor‐bearing nude mice. A7‐PEG seems to be a good candidate for targeted cancer therapy using antibody due to its high blood retention but low normal organ uptake.