bluuebunny/crossref_metadata_2025 huggingface dataset:
Primary Gastric Carcinoma Cells Frequently Lose Heterozygosity at the APC and MCC Genetic Loci
Authors: Tamura Gen , Maesawa Chihaya , Suzuki Yasushi , Ogasawara Satoshi , Terashima Masanori , Saito Kazuyoshi , Satodate Ryoichi
Published: August 2005

Loss of heterozygosity (LOH) at APC and MCC gene loci (both mapped to 5q21) was investigated in 24 surgical specimens of primary gastric carcinomas using the polymerase chain reaction after tumor cell enrichment by cell sorting based on differences in DNA content. LOH at APC and/or MCC was detected in 87% (13/15) of the cases; at the APC in 86% (12/14) and at the MCC locus in 100% (7/7). LOH at the APC locus was always accompanied by LOH at the MCC locus. LOH at the APC and/or MCC was found in both differentiated and undifferentiated types in both early and advanced stages of gastric carcinoma. Thus, LOH at APC and/or MCC is considered to be one of the most prevalent genetic alterations in human gastric carcinoma and occurs at an early stage of the carcinogenesis.
Synergistic Effect of Radiation on Colon Carcinogenesis Induced by Methylazoxymethanol Acetate in ACI/N Rats
Authors: Tanaka Takuji , Morishita Yukio , Kawamori Toshihiko , Suzui Masumi , Kojima Toshihiro , Sugie Shigeyuki , Mori Hideki
Published: August 2005

The effect on colon and liver carcinogenicity in rats of a single X‐irradiation exposure given either before or after methylazoxymethanol (MAM) acetate was studied in ACI/N rats of both sexes. A single dose of X‐irradiation (3 Gy) was administered either 3 months before or after three weekly s.c. injections of MAM acetate (25 mg/kg body weight). At 365 days after the start, the incidence and multiplicity of MAM acetate‐induced intestinal tumors were enhanced by X‐irradiation either prior to or after the MAM acetate treatment. In addition, X‐irradiation before MAM acetate increased the incidence of hepatocellular foci in either sex. In females, X‐irradiation either before or after MAM acetate exposure decreased intestinal tumorigenesis. These findings suggest an apparent synergism of these agents in intestinal carcinogenesis of male rats.
Influence of Gastric pH Modifiers on Development of Intestinal Metaplasia Induced by X‐Irradiation in Rats
Authors: Watanabe Hiromitsu , Okamoto Taro , Fudaba Yasuhiro , Ogundigie Peter Osa , Ito Akihiro
Published: August 2005

The influence of gastric pH on intestinal metaplasia was examined in male Crj:CD(SD) rats. At the age of 5 weeks, animals were irradiated with two 10 Gy doses of X‐rays to the gastric region at a 3‐day interval (total 20 Gy), and 6 months after irradiation, received either secretin or histamine in silicon tubes for 2 months or had their bilateral submandibular salivary glands removed. The incidences of intestinal metaplasia in the fundus of animals after administration of secretin or histamine, or removal of the salivary glands were reduced, along with the pH values, as compared with values for rats given X‐rays alone. In both the pyloric and the fundic gland mucosae, the numbers of alkaline phosphatase (ALP)‐positive foci and type B metaplasias (intestinal crypts without Paneth cells) were also significantly decreased (P<0.01). In a second experiment, started six months after irradiation, rats were kept on 1% sodium chloride (NaCl) diet for 6 months. Subsequent removal of salivary glands along with histamine treatment brought about a marked drop in pH and in numbers of ALP‐positive foci after three and five days. The present results thus indicated that development and maintenance of intestinal metaplasia can be influenced by a decrease of pH value.
Why Are Human Cells Resistant to Malignant Cell Transformation in vitro?1
Authors: Kuroki Toshio , Huh Nam‐ho
Published: August 2005

Transformation of human cells, both induced and spontaneous, is an extremely rare event, whereas rodent cells are relatively easily transformed when treated with a single carcinogenic agent. The present review addresses the question of why human cells are resistant to malignant transformation in vitro. To facilitate understanding of the problem, the process of transformation is divided operationally into two phases, i.e. phase I, immortalization; and phase II, malignant transformation. In human cells, one‐phase transformation, i.e., the consecutive occurrence of phases I and II due to the action of a single carcinogenic agent, is observed only rarely. Once human cells are immortalized, however, malignant transformation by chemical carcinogens or oncogenes proceeds, suggesting that for human cells, phase I immortalization is a prerequisite for such transformation to take place. To date, about 20 papers have been published describing protocols for the two‐phase transformation of a variety of human epithelial cells and fibroblasts. In most experiments, SV40, human papilloma viruses and their transforming genes are utilized for induction of phase I (immortalization) followed by the use of chemical carcinogens or activated oncogenes for induction of phase II (malignant transformation). Possible mechanisms that would render human cells refractory to transformation are discussed below.
Enhanced Growth Potential of Cultured Rahbit Tracheal Epithelial Cells Following Exposure to N‐Methyl‐N′‐nitro‐N‐nitrosoguanidine
Authors: Kitamura Hitoshi , Gray Thomas E. , Jetten Anton M. , Inayama Yoshiaki , Nettesheim Paul
Published: August 2005

To establish a standardized model for the transformation of rabbit airway epithelial cells, we attempted to transform rabbit tracheal epithelial (RbTE) cells in culture with N‐methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG). RbTE cells, harvested by enzymatic digestion from male New Zealand white rabbits, were plated onto feeder layers of irradiated 3T3 cells. Control cells proliferated exponentially during the 2nd week of culture and reached the plateau phase by the 3rd week. Cells exposed to MNNG (0.1 γg/ml) proliferated in a fashion similar to the control cells, except that there was some delay before proliferation began. The clonogenic activity of RbTE cells rapidly decreased in parallel with the increase in cell population equally in the control and MNNG groups. During the late plateau phase, cells exposed to MNNG regained clonogenic activity, and this compartment size expanded with time, whereas the clonogenic activity in control cultures remained below the detectable level. In RbTE cell cultures exposed three times to 0.1 γg/ml MNNG, large, persistent and proliferating colonies emerged at a frequency of 1–3 × 10 x−2 among the surviving clones, whereas all the control cultures eventually became senescent. The MNNG‐indnced alteration in the growth potential of RbTE cells, i.e., the extended lifespan, and the maintenance and even expansion of clonogenic activity, was similar to that of transformed rat tracheal epithelial cells. However, no immortal cell line could be established from these growth‐altered RbTE cells. We therefore concluded that the growth‐altered RbTE cells were partially transformed.
Characterization of the Promoter Region of the Human c‐kit Proto‐oncogene
Authors: Yamamoto Katsuya , Tojo Arinobu , Aoki Nobuo , Shibuya Masabumi
Published: August 2005

The c‐kit proto‐oncogene encodes a tyrosine kinase receptor for stem cell factor and plays a critical role in the growth and differentiation of various types of cells including hematopoietic stem cells. To investigate the mechanisms of its transcriptional regulation, we isolated the 5’flanking region of the human c‐kit gene and characterized its promoter activity in hematopoietic cells. Nucleotide sequence analysis revealed that the 1.2 kb 5’flanking region lacked a typical “TATA box,” but had a relatively high G + C content and four potential Sp1‐binding sites. Putative binding sites for AP‐2, basic helix‐loop‐helix proteins, Ets‐domain proteins, Myb and GATA‐1 were also found. Primer extension and S1 nuclease protection analyses of hematopoietic cells indicated that the major transcription start sites are 62 bp and 58 bp upstream of the translation start site. Essentially the same start sites were detected in non‐hematopoietic cells such as small cell lung carcinoma and glioblastoma: this single promoter in c‐kit is different from the multiple promoter system of c‐fms, a c‐kit‐related gene, in which at least two promoters are differently used in hematopoietic and non‐hematopoietic cells. An analysis of the c‐kit 5’flanking region using the bacterial chloramphenicol acetyltransferase gene (CAT assay) in human erythroleukemia HEL cells, which express the endogenous c‐kit mRNA at high levels, showed that a region from ‐180 to ‐22 is important for the expression of the c‐kit gene. In addition, a negative regulatory element(s) is suggested to be involved in the regulation of the c‐kit gene expression in mammals.
Membrane‐associated Lymphotoxin Expression and Functional Analysis of Lymphokine‐activated Killer Cells Derived from Tumor‐infiltrating Lymphocytes
Authors: Horiuchi Atsushi , Abe Yasuhito , Miyake Masazumi , Kimura Katsuhiko , Hitsumoto Yasuo , Takeuchi Nozomu , Kimura Shigeru
Published: August 2005

The expression of a membrane‐associated lymphotoxin molecule (mLT) on lymphokine‐activated killer (LAK) cells obtained from 18 patients with malignant tumors and its role in the tumor cell killing mechanisms were investigated. LAK cells from tumor‐infiltrating lymphocytes (TIL‐LAK cells) were mainly composed of CD3‐positive cells, whereas LAK cells from peripheral blood lymphocytes (PBL‐LAK cells) were mainly composed of CD16‐ and CD56‐positive cells. However, mLT was found to be expressed on TIL‐LAK cells as well as PBL‐LAK cells. The degree of mLT expression correlated with the killing activity of LAK cells towards L929 cells (r=0.806, P<0.01, n = 15), but not with that towards Daudi or K562 cells. Although the degree of mLT expression correlated with the amount of secreted lymphotoxin (LT) in the supernatant of LAK cell culture, the secreted LT itself could not account for the tumor cell killing activity of LAK cells. Polyclonal rabbit anti‐LT antibody partially inhibited the killing activities of LAK cells towards L929 cells and this inhibition was found in the combination of autologous tumor cells and PBL‐LAK cells. These findings suggest the possibility that the mLT‐related cytotoxicity is involved in the tumor cell killing mechanisms of TIL‐LAK cells as well as PBL‐LAK cells.
Suppression of Anti‐tumor CD4+ T Cell Responsiveness in the Tumor‐bearing State and Its Recovery in in vitro Culture Free of Tumor Burden
Authors: Nagata Takako , Zou Jian‐Ping , Yamamoto Norihiko , Ono Shiro , Fujiwara Hiromi , Hamaoka Toshiyuki
Published: August 2005

We investigated whether the responsiveness of anti‐tumor CD4+ T cells suppressed in the tumor‐bearing state is reversed in conditions free of tumor burden. Spleen cells from BALB/c mice bearing a syngeneic tumor (CSA1M) 1–3 wk after inoculation with CSA1M cells produced interleukin‐2 (IL‐2) and IL‐4 upon in vitro culture without addition of exogenous tumor antigens. This lymphokine production was achieved through collaboration between anti‐CSA1M CD4+ T cells and antigen‐presenting cells (APC) that had been pulsed with CSA1M tumor antigens in vivo in the tumor‐bearing state. However, spleen cells from late (8–10 wk) tumor‐bearing stages produced reduced levels of lymphokine production despite the presence of comparable proportions of CD4+ T cells. Because APC in these cell populations exhibited enhanced capacities to present tumor antigens, reduced responsiveness was ascribed to the dysfunction of CD4+ T cells themselves. When spleen cells from early tumor‐bearing mice were preincubated for 1–2 days and recultured in fresh medium, the magnitude of lymphokine production by these cells was not changed. In contrast, the same protocol of preincubation and reculture for cells from late tumor‐bearing mice resulted in the recovery of anti‐tumor lymphokine‐producing capacity. The recovered capacity was comparable to or slightly higher than that expressed by cells from early tumor‐bearing stages. Since the CD4+ T cell content did not significantly differ before and after preincubation, enhanced lymphokine production was due to the recovered responsiveness of anti‐tumor CD4+ helper T cells. The recovery of anti‐tumor responsiveness was also induced in vivo by tumor removal at the late tumor‐bearing stage: spleen cells from mice 2–4 wk after tumor resection efficiently produced IL‐2 and IL‐4. These results indicate that the immunodysfunction of anti‐tumor CD4+ T cells induced in the tumor‐bearing state is reversible because release from tumor burden either by preincubation in vitro or by tumor removal in vivo results in almost complete recovery of the potent anti‐tumor responsiveness initially expressed.
Multidrug Resistance in Rat Colon Carcinoma Cell Lines CC531, CC531mdr+ and CC531rev
Authors: Gheuens Eric , van der Heyden Sylke , Elst Hilde , Eggermont Alexander , Van Oosterom Allan , De Bruijn Ernst
Published: August 2005

A rat colon carcinoma cell line, CC531, was exposed to stepwise increasing concentrations of colchicine. A cell line, CC531mdr+, which grows in the presence of 0.2 μM of colchicine was obtained. A revertant cell line, CC531rev was isolated upon colchicine withdrawal. The CC531mdr+ displayed a multidrug‐resistant phenotype. Marked resistance to the selecting agent colchicine, was found (RF= 37.5) as well as to vinblastine (RF=11.3) and actinomycin D (RF=2.6). Cross resistance to doxorubicin (RF=8) and daunorubicin (RF=13.3) was demonstrated. Verapamil was able to reverse drug resistance to colchicine and daunorubicin. The revertant cell line, CC531rev, showed increased sensitivity to colchicine (RF=0.43), vinblastine (RF = 0.13), doxorubicin (RF=0.28) and daunorubicin (RF = 0.56). Marked cross resistance to cis‐platinum (RF = 6.9) was also induced in CC531mdr+ and was maintained in CC531rev. We conclude that CC531 displays an intrinsic low‐level multidrug‐resistant phenotype, which was amplified in the CC531mdr+ variant. This correlates with a higher level of expression of P‐glycoprotein. CC531rev lacks the multidrug‐resistant phenotype and can be used as the drug‐sensitive counterpart of the latter two cell lines. Furthermore, it has been shown that in these cell lines cis‐platinum resistance is mediated through a mechanism independent of the multidrug‐resistant phenotype, since the revertant cell line CC531rev has lost the multidrug‐resistant phenotype while retaining the concomitantly induced cis‐platinum resistance of the multidrugresistant variant CC531mdr+.
Photodynamic Therapy for Cancers: A Clinical Trial of Porfimer Sodium in Japan
Authors: Kato Harubumi , Horai Takeshi , Furuse Kiyoyuki , Fukuoka Masahiro , Suzuki Shigeru , Hiki Yoshiki , Ito Yoshiaki , Mimura Seishiro , Tenjin Yoshio , Hisazumi Haruo , Hayata Yoshihiro
Published: August 2005

Photodynamic therapy utilizing Photofrin has proven to be an effective modality that can be used in the treatment of a wide variety of solid tumors and luminal cancers. An argon pumped dye laser or excimer dye laser was used to deliver 630 nm light via quartz fibers passed through the biopsy channel subsequent to i.v. injection of photosensitizer. In this study, 64 patients with superficial cancers were treated in this manner but only 58 patients, including 21 with roentgenographically occult lung cancer, 8 with stage I lung cancer, 5 with esophageal cancer, 12 with gastric cancer, 8 with cervical cancer and 4 with bladder cancer were evaluable. Complete remission was obtained in 48 out of 58 cases (82.8%). There was no serious complication except skin photosensitivity, which was seen in 13 patients. We conclude that photodynamic therapy is efficacious in the treatment of superficial cancers where complete remission may be achieved.
Identification of Human T Cell Leukemia Virus Type IIb Infection in the Wayu, an Aboriginal Population of Colombia
Authors: Ijichi Shinji , Zaninovic Vladimir , Leon‐S. Fidias E. , Katahira Yoshihiko , Sonoda Shunro , Miura Tomoyuki , Hayami Masanori , Hall William W.
Published: August 2005

Human T cell leukemia virus type II (HTLV‐II) is endemic in a number of native American populations and high rates of infection have also been demonstrated in intravenous drug abusers (IVDAs). Studies of virus isolates in the latter population have shown the existence of two closely related subtypes of the virus, HTLV‐IIa and HTLV‐IIb. To characterize the viruses present in native Americans, we analyzed by nucleotide sequence analysis the proviruses from the Wayu, an aboriginal population residing in Colombia, South America. The results showed HTLV‐IIb infection in this population, and also demonstrated remarkable conservation of sequence when compared to the proviruses in IVDAs.
H‐2Z Homozygous New Zealand Mice as a Model for B‐Cell Chronic Lymphocytic Leukemia: Elevated bcl‐2 Expression in CD5 B Cells at Premalignant and Malignant Stages
Authors: Okamoto Hiroshi , Nishimura Hiroyuki , Shinozaki Ayako , Zhang Danqing , Hirose Sachiko , Shirai Toshikazu
Published: August 2005

In New Zealand mice, the major histocompatibility complex (MHC) controls the development of both autoimmune disease and B cell chronic lymphocytic leukemia (B‐CLL). While H‐2d/H‐2z heterozygosity acts as one major predisposing genetic element for autoimmune disease, H‐2z/H‐2z homozygosity acts as an element for B‐CLL. In the H‐2z/H‐2z homozygotes, there was an age‐dependent increase in frequencies of CD5 B cells in the blood and spleen, and such CD5 B cells showed oligoclonal to monoclonal expansion, giving rise to B‐CLL. B‐CLL cells from these mice had surface phenotypes typical of CD5 B lineage cells, and expressed high levels of proto‐oncogene bcl‐2. Elevated bcl‐2 expression was also observed in premalignant B cells in the aged mice, thereby suggesting that apoptosis‐resistant, long‐surviving CD5 B cells with a self‐renewal capacity form the basis of malignant transformation. This model not only provides clues for analyzing multiple steps of genetic alterations involved in the generation of B‐CLL, but also sheds light on the correlation between B‐CLL and autoimmune disease.
Determination of c‐erbB‐2 Protein in Primary Breast Cancer Tissue Extract Using an Enzyme Immunoassay
Authors: Watanabe Toru , Fukutomi Takashi , Tsuda Hitoshi , Adachi Isamu , Nanasawa Takeshi , Yamamoto Hiroshi , Abe Kaoru
Published: August 2005

The c‐erbB‐2 protein in breast cancer tissue extract was determined by using an enzyme‐immunoassay (EIA) to see whether the quantitative determination of the oncoprotein correlates with the results of immunohistochemistry and other prognostic factors. Primary breast cancer from 104 patients was assayed for c‐erbB‐2 protein with an EIA that used two monoclonal antibodies directed against the extracellular domain of the protein. Pelleted tissue homogenate prepared routinely for hormone receptor assay was used as the starting material. The mean quantity of c‐erbB‐2 protein was 695 unit/mg protein (range 23 to 5939), and this correlated well with the results of immunohistochemical staining (P< 0.00001). It was found that 17.3%(18/104) of all tumors contained amounts of c‐erbB‐2 protein exceeding 1000 units/mg protein. All tumors with negative or weakly positive staining contained the oncoprotein as less than 1000 units/ing protein. The content of c‐erbB‐2 protein was correlated with the histologic grade (P=0.0022), mitotic index (P=0.0002) and degree of nuclear atypia (P=0.013). It was inversely correlated with progesterone receptor (P=0.006) and less strongly with estrogen receptor status (P=0.016). Values of hormone receptor concentration and c‐erbB‐2 protein content showed a hyperbolic relationship that suggested biological interactions between c‐erbB‐2 protein and steroid hormone receptors. We conclude that c‐erbB‐2 protein in tissue extracts of primary breast cancer can be determined reliably by EIA, and it seems feasible to explore further the advantages of introducing EIA as a routine laboratory examination for providing additional information about the biological aspects of breast cancer.
Induction of BCR‐ABL Fusion Genes by in vitro X‐irradiation
Authors: Ito Takashi , Seyama Toshio , Mizuno Terumi , Hayashi Tomonori , Iwamoto Keisuke S. , Dohi Kiyohiko , Nakamura Nori , Akiyama Mitoshi
Published: August 2005

The Philadelphia chromosome consists of a reciprocal translocation between the ABL oncogene at chromosome 9q34 and the BCR gene at chromosome 22q1l, resulting in the expression of chimeric BCR‐ABL mRNAs specific to chronic myelogenous leukemia (CML). Presence of the fusion gene can be detected with high specificity and sensitivity by means of reverse transcription and polymerase chain reaction. Using this assay, it was possible to detect BCR‐ABL fusion genes induced among HL60 cells after 100 Gy of X‐irradiation in vitro. In total, five fusion gene transcripts were obtained among 108 cells examined. These fusion genes contained not only CML‐specific BCR‐ABL rearrangements, but also other forms of BCR‐ABL fusions. These latter genes had junctions of BCR exon 4/ABL exon 2 intervened by a segment of DNA of unknown origin, BCR exon 5/ABL exon 2, and BCR exon 4/ABL exon 2. The results appear to be direct evidence for the induction of the BCR‐ABL fusion gene by X‐irradiation. In terms of leukemogenesis, it appears that only those cells bearing certain CML‐related BCR‐ABL fusion genes are positively selected by virtue of a growth advantage in vivo.
Detection of PML/Retinoic Acid Receptor α Gene Rearrangements by Polymerase Chain Reaction Using Genomic DNA in Patients with Acute Promyelocytic Leukemia
Authors: Tashiro Satoshi , Tanaka Kimio , Asou Hiroya , Kyo Taiichi , Dohy Hiroo , Suzuki Katsuyuki , Kamada Nanao
Published: August 2005

Breakpoints of the 15;17 translocation in patients with acute promyelocytic leukemia (APL) have been identified within PML and retinoic acid receptor α (RARA) genes in chromosomes 15 and 17, respectively. A wide heterogeneity was observed in the breakpoints on the PML and RARA genes. Therefore, amplification of the breakpoints region by polymerase chain reaction (PCR) with genomic DNA has been considered to be difficult. In the present study, a method was developed to detect the 15;17 translocation with genomic DNA. Of 13 patients with APL, four were detected to have the rearrangement of genomic DNA. At present, reverse transcriptase‐polymerase chain reaction analysis is one of the methods available for diagnosis and detection of the residual leukemic cells in APL. In this study, PCR analysis using genomic DNA of APL cells is proved to be useful for identifying the breakpoints of the PML and the RARA genes. Furthermore, this method is applicable to patients for whom RNA samples of the leukemic cells are not available.
Intracellular Metabolism and Cytotoxicity of Transferrin‐Neocarzinostatin Conjugates of Differing Molar Ratios
Authors: Sasaki Katsunori , Kohgo Yutaka , Kato Junji , Kondo Hitoshi , Niitsu Yoshiro
Published: August 2005

Transferrin‐neocarzinostatin (NCS) conjugates with differing molar ratios of drug to protein were synthesized and their intracellular metabolism was investigated. The conjugate mixtures of transferrin‐NCS were separated by DEAE‐Sephacel column chromatography. The separated molecular species were examined with respect to binding affinity to transferrin receptor, cytotoxicity and intracellular metabolism using the human leukemia cell line, K562. Transferrin‐NCS conjugate is capable of binding to transferrin receptors specifically and its reactivity became weaker as the ratio of bound NCS to transferrin was increased. Transferrin‐6NCS did not bind measurably to the receptor. On the other hand, the cytotoxicity was augmented when the number of NCS molecules bound per molecule of transferrin was increased to 4NCS/transferrin, while transferrin‐5NCS and transferrin‐6NCS species exhibited low activity. Examination of the kinetics of metabolism by pulse chase study using 125I‐labeled ligand indicated that unconjugated transferrin and transferrin‐NCS conjugates were internalized in similar ways, although the degradation of internalized conjugate was more marked in the case of transferrin‐4NCS than transferrin‐1NCS. Thus, the molar ratio of transferrin‐drug conjugate could be optimized with respect to both the binding activity to receptor and the intracellular metabolic pathway.
Delivery of Lymph Node‐targeted Adriamycin by Gastric Submucosal Liposomal Injection in Rabbits
Authors: Akamo Yoshimi , Yotsuyanagi Toshihisa , Mizuno Isamu , Ichino Tatsuo , Tanimoto Noritaka , Kurahashi Shingo , Saito Takaaki , Yamamoto Tetsuya , Yasui Tamotsu , Itabashi Yuji , Yura Jiro
Published: August 2005

We investigated the feasibility of specifically delivering adriamycin (ADR) to the regional lymph nodes via gastric submucosal injection of liposomal adriamycin (Lipo‐ADR) in a rabbit model. We determined the tissue distribution of ADR for up to 7 days after the gastric submucosal injection of Lipo‐ADR (0.4 nag/kg of ADR potency) and i.v. administration of an equal dose of free adriamycin (F‐ADR). The area under the ADR concentration‐time curve (AUC) of the regional lymph nodes was 85.4 μg‐day/g after gastric submucosal injection of Lipo‐ADR and 8.44 μg‐day/g after i.v. administration of F‐ADR. The targeting index of the regional lymph nodes, defined as the ratio of the AUC after gastric submucosal injection of Lipo‐ADR to the AUC after i.v. administration of F‐ADR, was 10.1. Gastric submucosal injection of Lipo‐ADR enhanced lymph node‐specific delivery of ADR compared with i.v. administration of F‐ADR. The targeting index was 0.47 for the heart, 0.25 for the bone marrow, and 0.41 for the spleen, indicating that gastric submucosal injection of Lipo‐ADR reduced delivery of ADR to these organs, as compared with i.v. administration of F‐ADR. These data demonstrate that gastric submucosal injection of Lipo‐ADR is well suited for specific delivery of ADR to the regional lymph nodes, suggesting that this method of administration may be useful in delivering preoperative adjuvant chemotherapy for preventing gastric cancer recurrence.
Differential Expression of a Human Sperm‐specific Isozyme in Seminoma Cells Transplanted in Scid‐nustr Mice
Authors: Takatera Hiroshi , Nomura Taisei , Itatani Hiroaki
Published: August 2005

An isozyme of human sperm‐specific lactate dehydrogenase, LDH‐X (C4) (EC 1.1.1.27), which is expressed only in differentiated germ cells (spermatozoa, spermatids and primary spermatocytes after midpachytene), appeared in the xenografted tumor cells of human seminoma and its metastatic lesions (lymph node and kidney) in scid (severe combined immunodeficiency)‐nudestreaker double mutant mice, though it was not expressed in the original tumor of the patient. The morphological pattern of seminoma cells also changed in the xenografts and metastatic lesions as in normal spermatogenesis. Thus, the human seminoma cells showed differential expression of the sperm‐specific isozyme in parallel with their morphological changes. However, the sperm‐specific isozyme disappeared in the mitotically dividing seminoma cells which were newly established from the LDH‐X positive xenograft.
Cell‐density‐dependent Expression of Cyp1a2 Gene in Monolayer‐cultured Adult Mouse Hepatocytes
Authors: Nemoto Nobuo , Sakurai Junko
Published: August 2005

Expression of Cyp1a1 and Cyp1a2 genes was investigated in adult C57BL/6NCrj mouse hepatocytes for up to 5 days after transfer to monolayer culture. CYP1A1 mRNA was substantially induced by treatment with 3‐methylcholanthrene during the observation period, independently of the seeded cell density. However, expression of CYP1A2 mRNA was dependent on cell density and was higher in cells cultivated at lower density. With increasing culture period the expression was decreased, so that only negligible levels were evident by day 5, and reduced expression of constitutive and induced CYP1A2 mRNA became apparent earlier in more densely seeded cells. This was not related to differences in numbers of inducer molecules per cell. While mouse hepatocytes incorporated tritium‐labeled thymidine under the given culture conditions, induction of expression of the two Cyp1a genes did not show any direct relationship with DNA synthesizing activity. These observations suggest some role for Cyp1a2 during changes in physiological state.
Activation of Cyp1a1 and Cyp1a2 Genes in Adult Mouse Hepatocytes in Primary Culture
Authors: Nemoto Nobuo , Sakurai Junko
Published: August 2005

Expression of Cyp1a1 and Cyp1a2 genes was investigated in adult C57BL/6NCrj mouse hepatocytes in primary culture for up to 5 days. When the cells were cultivated as monolayers on collagen‐coated dishes, CYP1A1 mRNA species were prominently induced after treatment with 3‐methylcholanthrene (MCA) throughout the observation period. Substantial induction of CYP1A2 mRNA by MCA was also observed at day 1 of cultivation, followed by a decrease to very low levels thereafter. In contrast, when cultivated on non‐coated dishes, the hepatocytes formed multicellular aggregates (spheroids) and prominent induction of both mRNA species was found for up to 5 days. Constitutive expression of CYP1A2 mRNA in spheroid culture was maintained throughout the observation period, whereas that in monolayer culture decreased rapidly. The time‐course of the induced CYP1A2 mRNA amounts after the treatment with MCA or 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) followed the same pattern as that of CYP1A1 mRNA. Expressed amounts of CYP1A1 or CYP1A2 mRNA in spheroid culture were higher than or similar to the levels in the case of in vivo production, respectively. Induction of both mRNA species was also observed in hepatocytes from nonresponsive DBA/2NCrj mouse in spheroid culture, but the expressed amount after MCA treatment was far smaller than for C57BL/6NCrj cells, despite equivalent expression in the two strains after TCDD. Activities of aryl hydrocarbon hydroxylase (AHH) and acetanilide 4‐hydroxylase (AAH) were elevated with either type of cultivation after treatment with MCA or TCDD, Ratios of AAH to AHH were not changed between the two cultures after 24 h treatment. However, the ratios in spheroid culture after 48 h treatment increased, whereas they did not change in monolayer culture. The present observations indicate that the spheroid culture is more suitable than the monolayer system for studying the mechanism of Cyp1a2 gene expression in adult mouse hepatocytes.
Establishment and Characterization of a Simian Virus 40‐Immortalized Osteoblastic Cell Line from Normal Human Bone
Authors: Chiba Hideki , Sawada Norimasa , Ono Takao , Ishii Seiichi , Mori Michio
Published: August 2005

We established a human osteoblastic cell line immortalized by simian virus 40 (SV40) in vitro, and designated it SV‐HFO. Immunocytochemically, the cells were positive for SV40 large T‐antigen, vimentin and osteocalcin, but negative for keratin and epithelial membrane antigen. The cells had characteristic morphologic and ultrastructural features of osteoblasts, produced alkaline phosphatase, and synthesized osteocalcin, the levels of which were elevated by treatment of the cells with 1α,25‐dihydroxyvitamin D3. The cells proliferated and showed such osteoblastic properties even under serum‐free conditions. The cells grew in soft agar, but did not form tumors when transplanted into athymic nude mice. Karyotypic analysis by the Q‐banding technique showed that these cells were of human origin. The SV‐HFO cell line is expected to serve as a suitable model for studying metabolism and carcinogenesis in human bone.
Hyperthermic Enhancement of Cytotoxicity and Increased Uptake of cis‐Diamminedichloroplatinum(II) in Cultured Human Esophageal Cancer Cells
Authors: Miyahara Tokiharu , Ueda Kunihiro , Akaboshi Mitsuhiko , Shimada Yutaka , Imamura Masayuki , Utsumi Hiroshi
Published: August 2005

Thermal enhancement of cytotoxicity of cis‐diamminedichloroplatinum(II) (CDDP) has been well recognized and applied clinically to chemotherapy of various malignancies, but its fundamental mechanism remains to be elucidated. In order to obtain a clue to this mechanism, we analyzed the effect of hyperthermia on the uptake and subsequent distribution of [195mPt]CDDP in two lines of esophageal cancer cells (KYSE‐150 and KYSE‐170) established from clinical patients. First, we observed a significant increase in [195mPt]CDDP uptake by both types of cells at increasingly higher temperatures. The incorporated CDDP was distributed between the nucleus and the cytosol at a ratio of approximately 3:1, and the ratio remained the same at various temperatures. The CDDP was found in all four molecular fractions, i.e., DNA, RNA, protein, and TCA‐soluble, with a slight preference for DNA at higher temperatures. Enhancement of cytotoxicity required simultaneous, and not sequential, treatments with CDDP and hyperthermia; hyperthermia after CDDP treatment increased the efflux of CDDP from the cells, and rather reduced the cytotoxicity of CDDP. These results suggest that thermal enhancement of the cytotoxicity of CDDP is caused mainly by acceleration of the drug entry into the cell, probably due to increased permeability, and a consequent increase in the amount of CDDP binding to DNA. This mechanism gives support for clinical trial of simultaneous treatment with CDDP and hyperthermia.
Caffeine Modulates the Antitumor Activity and Toxic Side Effects of Adriamycin
Authors: Sadzuka Yasuyuki , Mochizuki Eiko , Takino Yoshio
Published: August 2005

To improve both the survival and the response rate of patients, it is necessary to find modifiers which enhance the effects of known anticancer agents. In this study, we examined the effects of caffeine on the antitumor activity and side effects of antitumor agents, using CDF1 male mice. The combination of caffeine with adriamycin significantly enhanced the antitumor activity of adriamycin, by 1.5‐fold and 1.9‐fold in single‐ and multi‐administration schedules, respectively, compared to the activity of adriamycin only. However, the combination of caffeine with cisplatin had no effect on the antitumor activity of cisplatin in either administration schedule. We examined two biochemical parameters, lipid peroxide level and glutathione peroxidase activity, as indices of adriamycin‐induced side effects. The caffeine combination did not enhance the adriamycin‐induced changes in these two parameters. Regarding the lethal effect of adriamycin, the caffeine combination had no effect in the single administration schedule, hut in the multi‐administration schedule, it tended to reduce this acute toxicity. These results suggest that the combination of caffeine with adriamycin can significantly increase the in vivo antitumor activity of this agent without increasing its side effects.
Revisiting drug progression: long‐range effects of early tobacco use
Authors: Vega William A. , Gil Andres G.
Published: August 2005

Aims  Drug progression models have been a cornerstone of scientific and public policy discussions for decades. These models have been criticized for their lack of causal mechanisms leading to drug dependence. Future research should focus on identification of pathways and covariates. This study re‐examines tobacco use onset and progression to drug dependence in a multi‐ethnic sample followed longitudinally from early to late adolescence (1990 to 1998–2000).

Methods  Data were collected in schools (n = 1208) during early adolescence (mean age 11.07), and subsequently face‐to‐face interviews were conducted at late adolescence (mean age 20.01).

Findings  Results indicated ethnic differences in rates and progression of tobacco use, with African Americans and foreign‐born Latinos having larger proportions of abstainers and lower rates of persistent use. Most early adolescent smokers progressed to regular use. The odds of progression to marijuana abuse or dependence by later adolescence were highest (O.R. = 4.9) among persistent smokers, but not significant for foreign‐born Latinos. The odds of progression to drug abuse or dependence were also highest (O.R. = 6.4) for persistent smokers, but not significant for African Americans.

Conclusions  Implications for research on pathways and mechanisms of progression are discussed. Prevention programs may interrupt drug progression if they delay onset of tobacco use until mid‐adolescence. Preventing targeted marketing efforts by the tobacco industry, regulating and enforcing tobacco control laws and pricing cigarettes at cost levels that adolescents find prohibitive are effective supplements to traditional behavior change interventions.
Non‐linear relationships between cognitive function and alcohol consumption in young, middle‐aged and older adults: the PATH Through Life Project
Authors: Rodgers Bryan , Windsor Timothy D. , Anstey Kaarin J. , Dear Keith B. G. , F. Jorm Anthony , Christensen Helen
Published: August 2005

Aims  To investigate associations, including non‐linear relationships, between cognitive function and alcohol consumption, testing for moderating effects of age and gender and for differences across outcome measures.

Design  Cross‐sectional general population samples of three age cohorts.

Setting  Canberra and Queanbeyan, Australia.

Participants  The total sample of 7485 consisted of 2404 men and women aged 20–24 years, 2530 aged 40–44 years, and 2551 aged 60–64 years, selected from the electoral rolls.

Measurements  Self‐report data using hand‐held computers provided weekly alcohol consumption from the Alcohol Use Disorders Identification Test (AUDIT) frequency, quantity and binge‐drinking items, and socio‐demographic factors. Spot‐the‐Word, digits backwards, the Symbol‐Digit Modalities Test (SDMT), immediate recall and reaction‐time tests were conducted by trained interviewers.

Findings  Findings varied across dependent variables, but there was a general tendency for light drinkers (up to 20/10 g alcohol per day in men/women, respectively) to perform better than abstainers, occasional drinkers or those drinking at hazardous/harmful levels (>40/20 g per day in men/women). Poorer performance of hazardous/harmful drinkers was seen only in men, whereas that of abstainers was evident in both sexes but was stronger in women. After adjustment for education and race, male hazardous/harmful drinkers no longer performed significantly less well than light drinkers, whereas male and female abstainers and occasional drinkers still did so.

Conclusions  Abstainers have poorer cognitive function than light drinkers and further investigation is needed to determine what factors contribute to this.
The nature, time course and severity of methamphetamine withdrawal
Authors: McGregor Catherine , Srisurapanont Manit , Jittiwutikarn Jaroon , Laobhripatr Suchart , Wongtan Thirawat , White Jason M.
Published: August 2005

Aims  To characterize the natural history of methamphetamine withdrawal during the first 3 weeks of abstinence.

Design  Cross‐sectional study with comparison group.

Setting  A substance use treatment facility in Chiang Mai Province, Thailand.

Participants  The sample comprised 21 in‐patients undergoing treatment for methamphetamine dependence. Nine age‐ and sex‐matched non‐dependent individuals provided comparison data.

Measurements  Instruments including: the Amphetamine Withdrawal Questionnaire, a modified version of the Cocaine Selective Severity Assessment, Clinical Global Impression scale and the St Mary's Hospital Sleep Questionnaire were completed daily for the first 3 weeks of abstinence.

Findings  Methamphetamine withdrawal severity declined from a high initial peak within 24 hours of the last use of amphetamines reducing to near control levels by the end of the first week of abstinence (the acute phase). The acute phase of amphetamine withdrawal was characterized by increased sleeping and eating, a cluster of depression‐related symptoms and less severely, anxiety and craving‐related symptoms. Following the acute withdrawal phase most withdrawal symptoms remained stable and at low levels for the remaining 2 weeks of abstinence.

Conclusions  This study has provided evidence of a methamphetamine withdrawal syndrome that can be categorized into two phases, the acute phase lasting 7–10 days during which overall symptom severity declined in a linear pattern from a high initial peak, and a subacute phase lasting at least a further 2 weeks.
State and diagnostic value of plasma tissue factor in early‐hospitalised patients with chest pain
Authors: van Der Putten Roy F. M. , Velthuis Henk te , de Zwaan Chris , Aarden Lucien A. , Glatz Jan F. C. , Hermens Wim T.
Published: August 2005

To study the state and diagnostic value of plasma tissue factor (TF) in patients with acute coronary syndromes (ACS), we quantitatively compared plasma TF antigen and TF activity in 90 early‐hospitalised patients with chest pain. Using high‐affinity antibodies, a sensitive assay for TF antigen was developed with a detection limit of 40 fmol/l. One of the antibodies was used to capture TF from plasma and, after elution and dialysis‐free reconstitution in phospholipid‐glucoside micelles, absolute amounts of TF activity could be measured with a detection limit of 80 fmol/l. All TF in plasma was found to be exposed, and a value of 2·5(1·1–14·8) pmol/l (median with range) was found for TF antigen. Most of this TF antigen (70–80%) circulated in a (potentially) functional state. Left in its in vivo state, however, TF captured from plasma was totally inactive, probably because of the lack of a procoagulant matrix. Compared with controls with non‐cardiac chest pain, TF activity was unchanged and TF antigen about 25% elevated in ACS patients. Combined with the markers prothrombin fragment F1+2 and fatty acid‐binding protein, TF did not improve the early diagnosis of ACS.
Effectiveness of a mutual support group for families of patients with schizophrenia
Authors: Chien Wai Tong , Chan Sally , Morrissey Jean , Thompson David
Published: August 2005

Aim.  This paper reports a study to examine the effectiveness of a 12‐session mutual support group for Chinese families caring for a relative with schizophrenia compared with a psycho‐educational group and routine family support services in Hong Kong.

Background.  Schizophrenia is a disruptive and distressing illness for patients and their families. With the current trend of community care for mental illness, there is evidence that family intervention reduces patient relapse and re‐hospitalization, satisfies the health needs of families and enhances their coping capabilities.

Methods.  A randomized controlled trial was conducted from May 2002 to June 2003 with 96 Chinese families of a relative with schizophrenia selected from two psychiatric outpatient clinics in Hong Kong. Families were randomly assigned to receive mutual support (n = 32), psycho‐education (n = 33) or standard care only (n = 31). The interventions were delivered at outpatient clinics over a 6‐month period. Pre‐ and post‐ (1 week and 6 months) testing took place and families’ functioning, mental health service utilization, patients’ level of functioning and duration of re‐hospitalization were measured.

Results.  At both post‐test periods, family caregivers and patients in the mutual support group reported statistically significant improvements on family and patients’ level of functioning, when compared with their counterparts in the psycho‐education and standard care groups.

Conclusions.  The findings support the use of mutual support groups as an effective modality of family intervention in a Chinese population caring for a family member with schizophrenia to improve both family and patient functioning.
Chinese version of the Childbirth Self‐efficacy Inventory
Authors: Ip Wan‐Yim , Chan Dominic , Chien Wai‐Tong
Published: August 2005

Aim. This paper reports a study to translate the Childbirth Self‐efficacy Inventory into Chinese and examine its reliability and validity among pregnant Chinese women in Hong Kong.

Background. Self‐efficacy for childbirth has been emerged as an important psychological construct in childbearing care. A reliable and valid self‐efficacy measure for pregnant women is crucial to the understanding of their psychological preparation, as well as the development of an appropriate childbirth education programme.

Methods. Two experienced midwives undertook translation of the Childbirth Self‐efficacy Inventory into Chinese, and another two experienced midwives independently conducted back translation. An expert panel of six healthcare professionals and 10 pregnant women examined the face and content validity of the translated instrument. A convenience sample of 148 pregnant Chinese women of not <36 weeks of gestation, and attending a regional teaching hospital in Hong Kong, were invited to complete the translated inventory and a demographic data sheet.

Results. The Childbirth Self‐efficacy Inventory indicated high internal consistency. Principal components analysis supported the fact that each of the efficacy and outcome expectancy subscales is uni‐dimensional. Neither scores in the efficacy nor outcome expectancy subscales suggested any statistically significant relationships with parity, age, education and attendance at childbirth education classes. No statistically significant differences in efficacy and outcome expectancy scores were found between the active phase (when contractions are not more than 5 minutes apart) and second stage (when pushing out the baby) of labour.

Conclusion. The study provides initial support for the reliability and validity of the Childbirth Self‐efficacyInventory. Although its sensitivity in differentiating between the two stages of labour was not evident, the distinguishing role of its expectancy subscales has been identified.
Weak relationships between suppression of melatonin and suppression of sleepiness/fatigue in response to light exposure
Authors: RÜGER MELANIE , GORDIJN MARIJKE C. M. , BEERSMA DOMIEN G. M. , DE VRIES BONNIE , DAAN SERGE
Published: August 2005

In this paper we examine the relationship between melatonin suppression and reduction of sleepiness through light by comparing three different data sets. In total 36 subjects participated in three studies and received 4 h of bright light either from midnight till 4:00 hours (experiments A and B) or from noon till 16:00 hours (experiment C). In experiment A (night‐time light, partial illumination of the retina, pupil dilated) subjects were exposed to either 100 lx of ocular light on the temporal, 100 lx on the nasal part of the retina, or <10 lx of dim light on the whole retina. In experiments B (night‐time light, whole retina, pupil not dilated) and C (daytime light, whole retina, pupil not dilated) subjects were exposed either to bright (5000 lx) or to dim light (<10 lx). Subjective sleepiness/fatigue and melatonin concentrations in saliva were assessed hourly in all three experiments. For experiment A, a significant suppression of melatonin due to nasal and temporal illumination of the retina was found, that was not accompanied by a detectable reduction of subjective sleepiness/fatigue. For experiment B we found a suppression of melatonin that was paralleled with a significant reduction in subjective sleepiness, but not in fatigue. During experiment C we found no melatonin suppression but a reduction of subjective sleepiness, but also no effect on fatigue. From these data we conclude that the effects of light on sleepiness/fatigue are not mediated by melatonin and that the influence of endogenous melatonin concentration on sleepiness/fatigue is restricted.