bluuebunny/crossref_metadata_2025 huggingface dataset:
Cesarean Delivery in Native American Women:  Are Low Rates Explained by Practices  Common to the Indian Health Service?
Authors: Mahoney Sheila F. , Malcoe Lorraine Halinka
Published: August 2005

ABSTRACT:  Background:
Studying populations with low cesarean delivery rates can identify strategies for reducing unnecessary cesareans in other patient populations. Native American women have among the lowest cesarean delivery rates of all United States populations, yet few studies have focused on Native Americans. The study purpose was to determine the rate and risk factors for cesarean delivery in a Native American population. Methods: We used a case‐control design nested within a cohort of Native American live births, ≥ 35 weeks of gestation (n = 789), occurring at an Indian Health Service hospital during 1996–1999. Data were abstracted from the labor and delivery logbook, the hospital's primary source of birth certificate data. Univariate and multivariate analyses examined demographic, prenatal, obstetric, intrapartum, and fetal factors associated with cesarean versus vaginal delivery. Results: The total cesarean rate was 9.6 percent (95% CI 7.2–12.0). Nulliparity, a medical diagnosis, malpresentation, induction, labor length > 12.1 hours, arrested labor, fetal distress, meconium, and gestations < 37 weeks were each significantly associated with cesarean delivery in unadjusted analyses. The final multivariate model included a significant interaction between induction and arrested labor (p < 0.001); the effect of arrested labor was far greater among induced (OR 161.9) than noninduced (OR 6.0) labors. Other factors significantly associated with cesarean delivery in the final logistic model were an obstetrician labor attendant (OR 2.4; p = 0.02) and presence of meconium (OR 2.3; p = 0.03). Conclusions: Despite a higher prevalence of medical risk factors for cesarean delivery, the rate at this hospital was well below New Mexico (16.4%, all races) and national (21.2%, all races) cesarean rates for 1998. Medical and practice‐related factors were the only observed independent correlates of cesarean delivery. Implementation of institutional and practitioner policies common to the Indian Health Service may reduce cesarean deliveries in other populations.
What Information, Advice, and Support Do Women Want With Breastfeeding?
Authors: Graffy Jonathan , Taylor Jane
Published: August 2005

ABSTRACT:  Background:
Breastfeeding conveys many benefits, but women often encounter difficulties in the first few weeks. The objective of this study was to examine women's perspectives on the information, advice, and support they receive with breastfeeding. Methods: A qualitative analysis was conducted of women's responses to open questions about their experiences of breastfeeding support. Participants were recruited as part of a randomized controlled trial of additional support from volunteer breastfeeding counselors, and they completed questionnaires when their babies were 6 weeks old. Results: Of the 720 women recruited to the trial, 654 began breastfeeding and completed postnatal questionnaires; 492 (75%) participants were first‐time mothers and 200 (31%) were of minority ethnic origin. At 6 weeks, 249 (38%) women were exclusively breastfeeding, 183 (28%) were both breastfeeding and bottle‐feeding, whereas 222 (34%) were exclusively bottle‐feeding. Although many women commented positively on their experiences, others thought they did not receive the information and support they needed. Thematic analysis of women's responses to open questions identified five components of the support that women wanted: information about breastfeeding and what to expect, practical help with positioning the baby to breastfeed, effective advice and suggestions, acknowledgment of mothers’ experiences and feelings, and reassurance and encouragement. Conclusions: Maternity services should address the components identified by the study findings as constituting good breastfeeding support. Guidance and information for family members and training for those involved in peer or professional initiatives should take into account women's views on what support they want, together with when and how they want it provided.
PRELIMINARY OBSERVATION ON PANCREATIC DUCT ADENOCARCINOMA INDUCED BY INTRADUCTAL ADMINISTRATION OF N‐ETHYL‐N′ ‐NITRO‐N‐NITROSOGUANIDINE IN DOGS
Authors: Kamano Toshiki , Azuma Noboru , Katami Atsuo , Tamura Junji , Sakakibara Noburu , Matsumoto Michio , Mizumoto Kazuhiro , Kitazawa Shunji , Konishi Yoichi
Published: August 2005

Pancreatic duct adenocarcinoma was induced by intraductal administration of N‐ethyl‐N′‐nitro N‐nitrosoguanidine (ENNG) in two mongrel dogs. A dog received a total dose of 595 mg of ENNG during 12 months and was sacrificed. Duct obstruction was detected by pancreatography and duct adenocarcinoma was found. Another dog was given a total dose of 350 mg of ENNG during 8 months and was sacrificed 26 months after the first administration of the carcinogen. Duct adenocarcinoma was found. No pancreatic tumors were found in 2 dogs given intraperitoneal N‐nitrosobis(2‐oxo‐propyl)amine at a total dose of 4000 mg or in 2 dogs given Tween 60 only. These results suggest that the direct presence of a carcinogen in the pancreatic duct was able to induce duct adenocarcinoma in dogs.
SPONTANEOUS OCCURRENCE OF PLACENTAL GLUTATHIONE S‐TRANSFERASE‐POSITIVE FOCI IN THE LIVERS OF LEC RATS
Authors: Oyamada Masahito , Dempo Kimimaro , Fujimoto Yoshinori , Takahashi Hidetoshi , Satosh Mutsumi I. , Mori Michio , Masuda Ryuichi , Yoshida Michihiro C. , Satosh Kimihiko , Sato Kiyomi
Published: August 2005

Spontaneous occurrence of placental glutathione S‐transferase (GST‐P)‐positive foci was observed in the livers of 5‐month‐old LEC rats. Quantitative studies revealed that GST‐P foci appeared after the onset of hepatitis. The number and size of GST‐P foci increased with age and more foci were induced in males than in females. No sex difference, however, was found in the incidence of hepatitis. Although hepatitis is necessary for the induction of GST‐P foci, it is insufficient for their further growth. Since hereditary hepatitis first appears at around 4 months of age, leading to a high incidence of hepatocellular carcinomas in later life, the spontaneous occurrence of the foci may be related to the development of hepatocellular carcinoma.
A B‐CELL LINE HAVING CHROMOSOME 14 ABERRATION AT BREAK BAND qll DERIVED FROM AN ADULT T‐CELL LEUKEMIA PATIENT
Authors: Miyamoto Kanji , Matsuoka Masao , Tomita Noriko , Suzuki Chieko , Sato Yasushi , Ishii Akio , Kitajima Ko‐ichi , Nonaka Hiroshi , Kondo Toshifumi , Hiraki Yoshio , Kobayashi Nobuyuki
Published: August 2005

A B‐cell line having translocations of chromosome 14 at break band q11 (the assigned locus of the α‐chain gene of the T‐cell antigen receptor) and chromosome 3 at break band p25 (the assigned locus of the c‐raf‐1 oncogene) was established from peripheral blood leukocytes of an adult T‐cell leukemia (ATL) patient. The same chromosome 14 aberration at break band q11 and chromosome 3 aberration at break band p25 were also found in fresh T‐cell leukemia cells. The B‐cell line is surface immunoglobulin (sIg)+, immunoglobulin gene rearrangement+, ATL‐specific antigen (ATLA)+, HTLV‐1 proviral genome+, Epstein‐Barr virus (EBV)‐associated nuclear antigen (EBNA)+ and the EBV DNA genome+. The fresh T‐leukemic cells were T‐cell receptor gene rearrangement+, the HTLV‐1 proviral genome+ and EBV DNA genome−.
GALLIUM CITRATE, A NEW SENSITIZER OF CELLS TO HYPERTHERMIA
Authors: Shinohara Kunio , Kawakami Noriko , Kugotani Maho , Nakano Hisako
Published: August 2005

The killing effects of heat were studied on cultured mammalian cells (L5178Y) pre‐incubated with gallium (Ga) citrate, which is a popular tumor‐imaging diagnostic agent. The cells showed higher sensitivity to heat when they were pre‐incubated with Ga‐citrate. The pre‐incubated cells showed decreased ATP levels, and this may be responsible for the heat‐sensitizing effect.
Comparison of XAD‐2 Column and Blue Cotton Batch Techniques for Isolation of Metabolites of 2‐Amino‐3‐methylimidazo[4,5‐f]quinoline
Authors: Inamasu Takeo , Luks Howard Jay , Weisburger John h.
Published: August 2005

In studies on the metabolism of 2‐amino‐3‐methylimidazo[4,5‐f]quinoline (IQ) in the rat, two methods were used to concentrate IQ and its metabolites in urine: XAD‐2 columns and blue‐cotton extraction. These methods were compared as to the total recovery of *14C‐label and the results of high‐performance liquid chromatography (HPLC) of the main metabolites. In the HPLC analysis, three major peaks in the polar region and two adjacent peaks in the nonpolar region having radioactivity were found in the urine from rats given *14C‐IQ. XAD‐2 columns adsorbed approximately 65% and blue cotton 23% of the applied isotope from the urinary metabolites. Both methods efficiently adsorbed and totally released the relatively nonpolar compounds in a mixture of metabolites, including the compound administered, IQ. However, they failed to retain the more polar metabolites. Thus, both the XAD‐2 column and blue cotton adsorption techniques may be useful mainly to concentrate nonpolar compounds from larger volumes of aqueous solutions.
Hepatocellular Tumorigenicity of Butylated Hydroxytoluene Administered Orally to B6C3F1 Mice
Authors: Inai Kouki , Kobuke Toshihiro , Nambu Shigeru , Takemoto Tsuyoshi , Kou Eihaku , Nishina Hajime , Fujihara Megumu , Yonehara Shoji , Suehiro Shin‐ichi , Tsuya Takafumi , Horiuchi Kenji , Tokuoka Shoji
Published: August 2005

Butylated hydroxytoluene (BHT), a preservative widely found in food as a food additive, was orally administered at concentrations of 1% and 2% of the diet to B6C3F1 mice for 104 consecutive weeks. Treated animals underwent a 16‐week recovery period prior to pathological examination. In male mice administered BHT, the incidence of mice with either a hepatocellular adenoma or a focus of cellular alteration in the liver was increased in a clear dose‐response relationship. The incidences of male mice with other tumors and the incidences of female mice with any tumor were not significantly increased as a consequence of BHT administration. The results of this study indicate BHT to be tumorigenic to the liver of the B6C3F1 male mouse.
Heterogeneous Origin of Established Non‐T, Non‐B Cell Lines from Two Adolescent Patients with Acute Lymphoblastic Leukemia
Authors: Nagasaka‐Yabe Miharu , Maeda Sakan , Mabuchi Osamu , Misu Hideo , Nakamura Shinobu , Kobayashi Yukio , Hirai Hisamaru , Sugiyama Taketoshi
Published: August 2005

Three leukemic cell lines were established from the bone marrow cells of two adolescents with non‐T, non‐B acute lymphoblastic leukemia (ALL) at relapse. Two cell lines from a 14‐year‐old girl and one from an 11‐year‐old boy were designated as KH‐3A, KH‐3B and KH‐4, respectively. Leukemic cells started to grow attached to the bone marrow stromal (BMS) cells. KH‐3A was positive for OKIa1 and positive at low percentages for B1, Leu‐1 and J5 antigens; KH‐3B reacted with OKIa1 and J5. Except for OKIa1, these two cell lines showed no surface marker change after 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) treatment. On TPA treatment, clones (KH‐3A‐2 and KM‐3A‐3) isolated from KH‐3A in agarose showed the induction of differentiation into T and B cell lineage. KH‐4 was positive for OKIa1 and positive at low percenteges for B1 and J5, and showed a strong reaction with OKIa1, B1 and J5 after TPA treatment. T cell receptor (TCR) β‐chain gene and immunoglobulin gene (JH and Cμ) rearrangements were found in KH‐3A, KH‐3B, and sublines isolated from KH‐3 (KH‐3A‐2 and ‐3) simultaneously. These findings indicate that BMS cells are useful for the establishment of leukemic cell lines and that some common ALL (cALL) cell populations may be heterogeneous.
Three Schedules of Recombinant Human Interleukin‐2 in the Treatment of Malignancy: Side Effects and Immunologic Effects in Relation to Serum Level
Authors: Sano Tetsuro , Saijo Nagahiro , Sasaki Yasutsuna , Shinkai Tetsu , Eguchi Kenji , Tamura Tomohide , Sakurai Masanori , Takahashi Hidenobu , Nakano Hidehiko , Nakagawa Kazuhiko , Hong Weon‐Seon
Published: August 2005

Recombinant human interleukin‐2 (rIL‐2) was administered to 34 patients with advanced malignancy. Three schedules of rIL‐2 administration employed were as follows: (A) 2‐hr iv infusion of 6.7 × 10*5 U/m*2/day (A1, 6 cases) or 2.2 × 10*6 U/m*2/day (A2, 8 cases) for five consecutive days; (B) 24‐hr continuous iv infusion of 3.3 × 10*5 U/m*2/day (B1, 3 cases), 6.7 × 10*5 U/m*2/day (B2, 7 cases) or 1.1 × 10*6 U/m*2/day (B3, 5 cases) for 28 consecutive days; and (C) 24‐hr continuous iv infusion of 6.7 × 10*5 U/m*2/day (C, 5 cases) for 5 consecutive days per week for four weeks. The common side effects were fever (79%), eosinophilia (61%), malaise (56%), erythema or rash (50%), chills (38%) and nausea or vomiting (35%), with the dose‐limiting toxicities being hypotension in group A, and renal dysfunction with fluid retention in groups B and C. In the case of 2‐hr iv infusion, rIL‐2 was rapidly cleared from the plasma, with a half life of about 30 min, while in the case of 24‐hr continuous infusion, more than 1 U/ml serum IL‐2 activity was maintained for 14 days in group B3. Natural killer (NK) and lymphokine‐activated killer (LAK) activities were augmented by rIL‐2 administration in patients of groups A, B3 and C. In eight patients of group B, NK and LAK activities transiently decreased after rIL‐2 administration, and recovered by day 3. The percentage of IL‐2 receptor and Leu HLA‐DR positive cells reached the peak level on day 7 in group B. In patients of group C, the percentage of Leu HLA‐DR positive cells as well as NK and LAK activities increased upon rIL‐2 administration and decreased during an intermission of two days. However, the percentage of rIL‐2 receptor positive cells increased during the intermission of rIL‐2. The most effective schedule of rIL‐2 administration was considered to be the schedule of group C on the basis of this study.
Serum Soluble Interleukin‐2 Receptor Levels in Patients with Adult T‐cell Leukemia and Human T‐cell Leukemia/Lymphoma Virus Type‐I Seropositive Healthy Carriers
Authors: Motoi Tomomi , Uchiyama Takashi , Uchino Haruto , Ueda Ryuzo , Araki Koh‐Ichi
Published: August 2005

Using an enzyme‐linked immunosorbent assay (ELISA) technique, we measured the soluble interleukin 2 receptor (s‐IL‐2R) levels in the sera of patients with adult T‐cell leukemia (ATL) in Japan. The s‐IL‐2R levels in the sera of the ATL patients were markedly higher (range 540‐310, 400 U/ml, mean ±SD=62,800 ±81,000 U/ml, n = 42) than those in normal individuals (range 42‐950 U/ml, mean ±SD=322 ±198 U/ml, n = 35, P<0.01). The patients with acute‐type or lymnhoma‐type ATL had high s‐IL‐2R levels (range 11,900‐310,400 U/ml, mean ±SD= 110,340 ± 370 U/ml, n = 15; range 26,400‐214,400 U/ml, mean ±SD=90,170 ±59,040 U/ml, n = 7, respectively). All of the patients with hypercalcemia (Ca>10 mg/dl) or elevated serum LDH levels (LDH > 500 IU/liter) also had s‐IL‐2R levels above 10,000 U/ml. The high s‐IL‐2R levels in the sera of ATL patients indicate abnormal IL‐2 receptor production and its release from the leukemic cells in vivo. Thus, the serum s‐IL‐2R level may be a sensitive and useful marker to monitor the total amount of tumor cells in ATL, especially in the lymphoma type. We next examined the serum s‐IL‐2R levels in human T‐cell leukemia/lymphoma virus type‐I (HTLV‐I) seropositive healthy carriers to investigate whether there might he abnormal IL‐2 receptor expression in such individuals. However, there was no statistically significant difference between the S‐IL‐2R level of 71 HTLV‐I seropositive healthy carriers (range 65‐880 U/ml, mean±SD =394±212 U/ml) and that of 71 age‐ and sex‐matched normal individuals (range 33‐950 U/ml, mean ±SD=357 ±224 U/ml) who lived in Okinawa Prefecture.
The Mechanism of Acquired Resistance to Cisplatin by a Human Ovarian Cancer Cell Line
Authors: Kikuchi Yoshihiro , Iwano Ichiro , Miyauchi Munenori , Kita Tsunekazu , Oomori Keibun , Kizawa Isao , Sugita Michio , Tenjin Yoshio
Published: August 2005

The present study was designed to elucidate the mechanism of resistance to cisplatin. A cisplatin‐resistant cell line (KFr) was established from KF cells derived from human serous cystadenocarcinoma of the ovary. The DNA histogram revealed an increase of S‐phase cells and a decrease of G1‐phase cells in cultured KFr cells, compared to that in cultured KF cells. Although the cisplatin content in the KF cells incubated with cisplatin at 10 μg/ml increased in a time‐dependent manner, that in the KFr cells remained unchanged during the experimental period. When 0.5 mg of cisplatin was administered ip to nude mice with KF or KFr tumor, the cisplatin content in the KFr tumor was significantly lower than that in the KF tumor. The KFr cells showed a cross‐resistance to L‐phenylalanine mustard, while no cross‐resistance to vincristine or 5‐fluorouracil was observed. These findings suggest that the mechanism of cisplatin resistance in the KFr cells involves a decrease of cisplatin accumulation in the tumor cells.
Potentiation of Antitumor Activity of Macrophages by Recombinant Interferon Alpha A/D Contained in Gelatin Microspheres
Authors: Tabata Yasuhiko , Uno Kazuko , Ikada Yoshito , Muramatsu Shigeru
Published: August 2005

Gelatin microspheres containing recombinant human interferon αA/D (A/D‐IFN) (IFN‐microspheres) potentiated the antitumor activity of mouse peritoneal macrophages (Mφo) much more efficiently than free A/D‐IFN. Mφo acquired the inhibitory activity on tumor cell growth by the ingestion of IFN‐microspheres without the aid of lipopolysaccharide (LPS), though LPS was required as a second signal for activating Mφo primed with free IFN. The IFN‐microspheres were much more efficient than free IFN plus LFS in respect of the IFN amount and the time required for Mφo activation. Furthermore, Mφo pretreated with the IFN‐microspheres maintained their activated state for a much longer period than those pretreated with free A/D‐IFN plus LPS. A monoclonal anti‐IFN‐αA antibody, which was capable of neutralizing A/D‐IFN, did not interfere with the Mφo activation by the IFN‐microspheres. Even human IFN‐αA was effective in activating murine Mφo similarly to A/D‐IFN, when given in the form of IFN‐microspheres, though human IFN‐αA in the free form was ineffective. These results argue that the mechanism of Mφo activation by the IFN‐microspheres is different from that by free IFN.
Isolation of Virus‐producing Transformants from Human Gastric Cancer Cell Line, HGC‐27, Infected with Human T‐cell Leukemia Virus Type I
Authors: Akagi Tadaatsu , Yoshino Tadashi , Motoi Makoto , Takata Hiroshi , Yano Shoki , Miyoshi Isao , Oka Takashi , Ohtsuki Yuji
Published: August 2005

A human anaplastic gastric cancer cell line, HGC‐27, showed marked degeneration with formation of multinucleated syncytia and cell detachment of nearly all cells which began 24 hr after and reached a maximum 2 to 3 days after co‐cultivation with X‐irradiated MT‐2 cells, HTLV‐I producing human cord leukocytes. Less severe degeneration without formation of syncytia was also observed in the cultures inoculated with cell‐free MT‐2 culture media. Morphologically altered cells began to proliferate and formed piled up colonies in some of the cultures co‐cultivated with X‐irradiated MT‐2 cells after a long culture period. The two clones designated HGC/MT2 (Cl‐1) and HGC/MT2 (Cl‐2) were separated by cell cloning. HGC/MT2 (Cl‐1) and HGC/MT2 (Cl‐2) cells were positive for HTLV‐I gag proteins (p19 and p24) and pX gene products, p40x, as demonstrated by immunohistochemistry and immunoblotting analysis, contained HTLV‐I provirus DNA, and consistently produced type C virus particles.
Selective Suppression of the Generation of Anti‐tumor L3T4+ but Not of Lyt‐2+ T Cell‐mediated Immunity in the Tumor‐hearing State
Authors: Sano Haruo , Sato Soichiro , Shima Junko , Tada Tsuyoshi , Fujiwara Hiromi , Hamaoka Toshiyuki
Published: August 2005

C3H/He mice hyperimmune against syngeneic MH134 hepatoma were prepared by intradermal (id) inoculation of viable tumor cells followed by surgical resection of the tumor and by repeated id challenges with viable tumor cells. Winn assays performed utilizing spleen cells from these mice have revealed that both Lyt‐2+ and L3T4+ T cell subsets from MH134‐hyperimmune mice produced complete tumor protection. The in vivo tumor‐neutralizing activity was also found in spleen cells from tumor‐bearing mice at various times after id implantation of MH134 tumor cells. However, in contrast to comparable tumor‐neutralization by Lyt‐2+ and L3T4+ T subsets from hyperimmune mice, only the Lyt‐2+ T cell subset from tumor‐bearing mice was capable of mediating the in vivo protective immunity. L3T4+ T cell‐mediated immunity was not detectable in the tumor‐bearing state irrespective of the length of the sensitization period with a primary growing tumor, but emerged in the mice which resisted the first tumor challenge after the resection of the primary tumor. These results indicate that the emergence of L3T4+ T cell‐mediated anti‐tumor immunity is stage‐dependent and the Lyt‐2+ T cells represent the main functional subset in the tumor‐bearing state, although both subsets of T cells are potentially capable of effecting anti‐tumor in vivo immunity. The results are discussed in relation to the selective suppression of the L3T4+ but not of Lyt‐2+ T cell function in the tumor‐hearing state.
Whole‐body Autoradiography of Tumor‐bearing Hamsters with a New Tumor Imaging Agent, Indium‐111‐labeled Porphyrin
Authors: Yamazaki Kosuke , Hirata Satoshi , Nakajima Susumu , Kubo Yoshihiko , Samejima Natsuki , Sakata Isao
Published: August 2005

We have synthesized a new tumor imaging agent, 111In‐labeled porphyrin (111In‐ATN‐2). In order to image transplantable pancreatic carcinoma in Syrian golden hamsters, we investigated the biodistribution of 111In‐ATN‐2 72 hr after injecting the agent by means of whole‐body autoradiography. The efficacy of the agent was compared with that of 67Ga citrate. The images with 111In‐ATN‐2 were found to be clearer than those with 67Ga citrate. Tumor‐to‐tissue radiodistribution ratios of the former were higher than those of the latter. Thus, 111In‐ATN‐2 seems to be more useful for tumor diagnosis.
Generation of High Yields of Syrian Hamster Cholangiocellular Carcinomas and Hepatocellular Nodules by Combined Nitrite and Aminopyrine Administration and Opisthorchis viverrini Infection
Authors: Thamavit Witaya , Moore Malcolm A. , Hiasa Yoshio , Ito Nobuyuki
Published: August 2005

Combined administration of 0.1% nitrite and 0.1% aminopyrine in the drinking water for eight to ten weeks resulted in subsequent development of both hepatocellular nodules and cholangiofibrotic lesions/cholangiocellular carcinomas in Syrian golden hamsters. Additional prior dosing with Opisthorchis viverrini metacercariae (100/animal) induced inflammatory and proliferative changes in the livers of infected hamsters and was associated with a significant increase in yields of hepatocellular and cholangiocellular preneoplastic and neoplastic lesions. Thus, environmental factors thought to be casually related to the high levels of human liver cancer observed in the Northeastern provinces of Thailand were sufficient to bring about development of equivalent tumors in experimental animals. The results indicate that parasite associated liver injury and non‐specific compensatory regeneration may play an important role in generation of both hepatocellular and cholangiocellular carcinomas in man.
Isolation and Characterization of ras‐Transfected BALB/3T3 Clone Showing Morphological Transformation by 12‐O‐Tetradecanoyl‐phorbol‐13‐acetate
Authors: Sasaki Kiyoshi , Mizusawa Hiroshi , Ishidate Motoi
Published: August 2005

The transformation frequency of mouse BALB/3T3 cells was significantly enhanced after transfection with an activated ras oncogene (v‐Ha‐ras) followed by treatment with a tumor promoter, 12‐O‐tetradecanoyl‐phorbol‐13‐acetate (TPA), suggesting that the ras oncogene acted as an initiator in two‐stage carcinogenesis. A cell clone (Bhas42) containing the ras oncogene was isolated from the ras‐transfected BALB/3T3 cells. Bhas42 cells were flat and showed contact inhibition, but the addition of TPA to quiescent Bhas42 cultures resulted in a dramatic change of cell morphology to spindle shape, doubling of the cell population, and increased DNA synthesis.
Stromal Cell‐dependent Growth of Leukemic Cells from Murine Erythroblastic Leukemia
Authors: Itoh Katsuhiko , Sasaki Ryuzo , Ono Katsuhiko , Tezuka Hiroaki , Sakoda Hiroto , Sawada Hitoshi , Hitomi Kiyotaka , Nakane Hideo , Uchiyama Takashi , Uchino Haruto , Mori Kazuhiro J.
Published: August 2005

Transplantable erythroblastic leukemia was induced by 300‐rad irradiation of C3H mice. Conditions for in vitro growth of the leukemic cells were studied. None of interleukin‐3, granulocyte/macrophage colony‐stimulating factor and erythropoietin could support the growth of the cells in vitro. In contrast, the leukemic cells grew into a stroma‐dependent cell line, ELM‐D, in close contact with the stromal cell layer of 900‐rad‐irradiated long‐term bone marrow culture. A stroma‐independent cell line, termed ELM‐I‐1, was further established from the non‐adherent population in the co‐culture of the leukemic cells, ELM‐D, with stromal cells. Reverse transcriptase activity was not detectable in ELM‐D or ELM‐I‐1 cells. Studies on binding and cross‐linking of 125I‐erythropoietin showed that ELM‐I‐1 cells had erythropoietin receptors, and two major radiolabeled protein products with molecular weights of 120 kDa and 140 kDa were detected on sodium dodecyl sulfate/polyacrylamide gel electrophoresis under reducing conditions.
Establishment and Characterization of Resistant Cells to Etoposide (VP16) from a Mouse Breast Cancer Cell Line, FM3A
Authors: Takagi Eishi , Kawatsu Hidetaka , Shimokata Kaoru , Nishiyama Yukihiro , Kojima Kiyohide , Yoshida Shonen
Published: August 2005

We established 4 cell lines resistant to VP16 from a mouse breast cancer cell line, FM3A. The IC50 values of all 4 resistant strains were approximately 2 μg/ml as measured by colony formation in soft agar; about 40 times higher than that of parent cell (0.05 μg/ml). These cells showed a cross‐resistance to VM26, a compound related to VP16, but not to a variety of other antitumor drugs including adriamycin, mitomycin C, cis‐platinum, 5‐fluorouracil, bleomycin, vincristine, 4‐hydroperoxycyclophosphamide, methotrexate and cytosine arabinoside. Topoisomerase II, the putative target of VP16, was partially purified from cells, and was assayed using knotted P4 phage DNA as a substrate. However, no significant difference was observed between enzymes from resistant cells and from the parent cells in either activity per cell or sensitivity to VP16. On the other hand, the resistance of these cell lines to VP16 was greatly reduced by adding a calcium antagonist, verapamil, to the soft agar at a concentration as low as 5μM, at which the viability of cells was hardly affected. A similar verapamil‐induced reduction in the resistance of the cells to VM26 was also observed. These results suggest that the acquired resistance may be largely due to an altered membrane permeability to drugs, which may be overcome by verapamil, rather than to an altered topoisomerase II.
Immunoscintigraphy and Pharmacokinetics of Indium‐111‐labeled ZME‐018 Monoclonal Antibody in Patients with Malignant Melanoma
Authors: Koizumi Mitsuru , Endo Keigo , Watanabe Yuji , Saga Tsuneo , Sakahara Harumi , Konishi Junji , Arano Yasusi , Miyachi Yoshiki , Kashihara‐Sawami Mari , Imamura Sadao
Published: August 2005

Immunoscintigraphic and pharmacokinetic characteristics of 111In‐labeled ZME‐018 monoclonal antibody were examined in 8 patients with malignant melanoma. Each patient received a single intravenous infusion of 20 mg of ZME‐018, coupled to 3 mCi of 111In without any acute toxicity. Scintigrams were taken 1, 3, and 6 days after the administration, and blood and urine samples were also taken frequently. Rapid clearance of some radioactivity was seen in early urine samples in the form of 111In DTPA, but after 1 day, urinary excretion of radioactivity was slow and steady, with an average of 2.5% of the injected dose excreted per day. The scans demonstrated that there was blood retention of radioactivity in the heart and great vessels 1 day after infusion and considerable clearance from the blood pool occurred by 3 days. However, 111In was deposited in the liver, spleen and bone for up to 6 days. The optimal time for imaging appeared to be at 3 days. Nineteen out of 26 known lesions or 6 out of 8 patients were positive. There were 21 lesions detected that were not suspected during the work‐up the patient. Five patients developed human anti‐mouse antibody in the serum by 3 weeks. These results suggest that immunoscintigraphy with 111In‐labeled ZME‐018 antibody is safe and useful for the detection of metastatic lesions in a selected group of patients with malignant melanoma.
ACTIVE PROLIFERATION OF MOUSE HEPATOCYTES IN PRIMARY CULTURE UNDER DEFINED CONDITIONS AS COMPARED TO RAT HEPATOCYTES
Authors: Sawada Norimasa , Lee Gang‐Hong , Mochizuki Yohichi , Ishikawa Takatoshi
Published: August 2005

Mouse and rat hepatocytes were investigated for replicative potential in primary culture under defined conditions. Mouse hepatocytes replicated at least twice or three times by the 7th day of culture in response to EGF, while only a half of rat hepatocytes replicated once. Thus a far greater potential for proliferation was demonstrated by mouse than rat cells, although the mouse cells ceased dividing by the 10th day of culture. Immunocytochemical examination revealed that the cells produced both albumin and α‐fetoprotein. Uitrastructural investigation revealed that these cells were immature hepatocytes in nature, based on the presence of microbodies with nucleoids. Thus, primary cultures of mouse hepatocytes seem to be a useful system for studying proliferation and transformation of hepatocytes in vitro.
METHYLATION STATUS OF EPIDERMAL GROWTH FACTOR RECEPTOR GENE IN LUNG CARCINOMA CELLS
Authors: Gamou Shinobu , Shimosato Yukio , Merlino Glenn T. , Shimizu Nobuyoshi
Published: August 2005

The methylation status of the epidermal growth factor receptor (EGFR) gene was compared in cell lines from four major types of lung carcinoma, small cell lung carcinoma (SCLC), large cell lung carcinoma, squamous cell carcinoma and adenocarcinoma, in order to examine whether DNA methylation is responsible for the suppression of EGFR gene in SCLC cells. Southern blot analysis revealed that the structural region of the EGFR gene is methylated to various degrees regardless of the expression of EGF receptor on the surface. An 8‐kilobase EcoRI fragment which contains the EGFR gene promoter region is readily digested with various methylation‐sensitive restriction enzymes in all types of cells, indicating that the EGFR gene 5’region is barely methylated. Thus, a mechanism other than DNA methylation appears to control EGFR gene expression and the lack of EGFR gene expression in SCLC cells may be caused by a paucity of some transcription regulatory factor(s).
Nodular Development of Spontaneous Epithelial Thymoma in (ACI/NMs × BUF/Mna)F1 Rats
Authors: Matsuyama Mutsushi , Matsuyama Takako , Ogiu Toshiaki , Kojima Akinori
Published: August 2005

The BUF/Mna strain is a high thymoma line of rats, and virtually all rats develop overt thymomas by the age of 40 weeks. To reveal the early morphologic changes in this thymomagenesis, thymuses and thyraomas were studied in (ACI/NMs × BUF/Mna)Fl (ABF1) rats, which inherit a thymoma susceptibility gene (Tsr‐1) from the BUF/Mna strain. At 50 weeks of age, 18% of ABF1 rats had developed medium to large thymomas, 54% had just began to develop multiple, small round nodules in their involuted thymuses, and the remaining 29% had involuted thymus only. The nodules were, microscopically, composed of cortex‐like tissues with a starry‐sky pattern, showing a quite similar structure to that of the large macroscopic thymomas of predominantly lymphocytic type seen in 104‐week‐old ABF1 or BUF‐Mna rats. Thus, the nodule was actually a small thymoma. In fact, their epithelial cells often had larger atypical nuclei than those in the adjacent involuted thymus cortex. At 104 weeks of age, the incidences of the medium to large thymomas and the small thymoma nodules in ABF1 rats were 64 and 19%, respectively. These results suggest that the thymoma of ABF1 rats occurs initially as multiple small nodules which develop further into medium to large overt thymomas as a result of growth and fusion.
Effects of Retinoids and Inhibitors of Arachidonic Acid Metabolism on Tumor‐promoter‐induced Soft Agar Colony Formation of Mouse Epidermal Cells and Rat Urinary Bladder Cells
Authors: Kanamaru Hiroshi , Hashimura Takayuki , Yoshida Osamu
Published: August 2005

Effects of retinoids and inhibitors of arachidonic acid metabolism on tumor‐promoter‐induced soft agar colony formation of mouse epidermal cells and rat bladder cells were evaluated. Topical application of retinoic acid, an anti‐tumor‐promoter, to female SENCAR mouse skin inhibited 12‐O‐tetradecanoylphorbol‐13‐acetate‐induced soft agar colony formation of mouse epidermal cells, an event proposed to be essential for tumor promotion. Effects of dietary retinyl acetate, nordihydroguaiaretic acid (NDGA) and quinacrine hydrochloride on colony formation of rat bladder cells were then examined. Male Fischer 344 rats were given 0.05% N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine for 3 weeks, followed immediately by the administration for 9 weeks of 5% sodium saccharin supplemented with or without 0.05% retinyl acetate, 0.1% NDGA or 0.01% quinacrine hydrochloride. Saccharin‐induced colony growth was significantly inhibited by the administration of retinyl acetate or NDGA, suggesting that these two agents have anti‐tumor‐promoting effects on rat bladder carcinogenesis. Thus, the colony‐forming assay might be useful for early detection of anti‐tumor‐promoters of skin and bladder.
A Case‐Control Study of Gastric Cancer and Diet in Northern Kyushu, Japan
Authors: Kono Suminori , Ikeda Masato , Tokudome Shinkan , Kuratsune Masanori
Published: August 2005

A case‐control study of gastric cancer was done in a rural area of northern Kyushu, Japan, in relation to dietary habits especially focusing on the relationship with the consumption of broiled fish. The study was based upon 139 cases of newly diagnosed gastric cancer at a single institution, 2,574‐ hospital controls and 278 controls sampled randomly from the residents of the study area (with sex and year of birth matched). No association was observed between the consumption of broiled fish and gastric cancer risk whether three types of broiled fish (raw fish, dried fish and salted fish) were analyzed separately or as a single category. However, consistently in the comparisons with both sets of controls, the risk of gastric cancer was inversely related with the consumption of fruits and positively associated with cigarette smoking. A decreased risk of gastric cancer was also noted among those with high consumption of green tea (10 or more cups per day).
Production of Monoclonal Antibodies Directed against Carbohydrate Moieties of Cell Surface Glycoproteins
Authors: Fukui Shigeyuki , Numata Yoshito , Kurosaka Akira , Kitagawa Hiroshi , Nakada Hiroshi , Funakoshi Ikuo , Kawasaki Toshisuke , Takahashi Yohei , Hayashi Kazuma , Yamashina Ikuo
Published: August 2005

Through the use of a technique for raising monoclonal antibodies, coupled with a solid‐phase radioimmunoassay utilizing immobilized glyeopeptides prepared from the surface membranes of the colorectal cancer cells (LS 180) used for the immunization, carbohydrate‐directed monoclonal antibodies were obtained. One of the monoclonal antibodies, MLS 102, reacted immunohistochemically intensely with the colorectal cancer cell surface and the mutinous glycoproteins secreted by the cancer cells, but only weakly with normal colon tissue. The antigenic determinant recognized by MLS 102 was the carbohydrate moiety of glycoproteins with terminal sialic acid. The antigens defined by other monoclonal antibodies, MLS 103 and 104, were immunohistochemically detected in both normal colonic epithelial and cancer cells. These antibodies seemed to recognize the carbohydrate moieties of both glycoproteins and glycolipids. The method described in this report can be generally applied to raise cell surface carbohydrate‐directed antibodies.
Preparation of a Monoclonal Antibody Specific for 1‐Methyladenosine and Its Application for the Detection of Elevated Levels of 1‐Methyladenosine in Urines from Cancer Patients
Authors: Itoh Kunihiko , Mizugaki Michinao , Ishida Nakao
Published: August 2005

A monoclonal antibody specific for a modified nucleoside, 1‐methyladenosine, was prepared and characterized. This antibody, termed AMA‐2, reacts with 1‐methyladenosine and 1‐methyladenine but not with other nucleosides, particularly methylated adenosines other than 1‐methyladenosine and methylated guanosines, tested in this investigation. In our experiments, AMA‐2 was used in an enzyme‐linked immunosorbent assay (ELISA) system for the quantitation of the levels of 1‐methyladenosine in urine. Sensitivity was in the picomole range and accuracy was nearly equal to that of the high‐performance liquid chromatography (HPLC) assay system. Urinary levels of 1‐methyladenosine in healthy donors and patients with various advanced cancers were determined by the inhibition ELISA. The amount of 1‐methyladenosine in urine of 33 healthy donors was 1.91±0.66 nmol/μmol creatinine. In 54% (51/94) of patients, urinary 1‐methyladenosine was elevated above the mean plus 2 standard deviations for the healthy donors (3.23 nmol/μmol creatinine). In patients with leukemia, esophageal cancer, stomach cancer, colon cancer, and bladder cancer, urinary levels of 1‐methyladenosine were significantly elevated. In patients with leukemia, urinary 1‐methyladenosine levels changed almost in parallel with the change in the clinical response during chemotherapy. These results suggest that urinary 1‐methyladenosine might be useful in monitoring the effectiveness of therapy.
Pepsinogens I and II in Gastric Cancer: An Immunohistochemical Study Using Monoclonal Antibodies
Authors: Huang Shih Che , Miki Kazumasa , Sano Junjiro , Ichinose Masao , Kawamura Norio , Oka Hiroshi , Hirano Kazuyuki , Furihata Chie , Masugi Yozo , Takahashi Kenji
Published: August 2005

Monoclonal antibodies were used to examine the immunohistochemical expression of pepsinogens I and II in 31 early and 76 advanced gastric cancers. Of the 107 carcinomas studied, 19 contained pepsinogen II and only 3, found exclusively in pepsinogen II‐positive cases, contained pepsinogen I. Gastric cancer produces pepsinogen II more frequently than pepsinogen I, and production of the latter is significantly associated with the former. Historically, there were 54 intestinal‐type and 53 diffuse‐type cancers. The former produced pepsinogen II more frequently than the latter. In the diffuse type, the four pepsinogen II‐positive cases were found exclusively in females. Although the pepsinogen expression was independent of the macroscopic features in advanced gastric cancer, it was found that the protruded‐type early gastric cancer produced pepsinogen II more frequently than the depressed type. Incidences of pepsinogen positivity were not different between early and advanced gastric cancers or between cancers with or without lymph node metastasis, suggesting that production of pepsinogen is independent of tumor growth.
Effects of a Combination of Cyclophosphamide and Human Recombinant Interleukin 2 on Pulmonary Metastasis after the Surgical Removal of a 3‐Methylcholanthrene‐induced Primary Tumor in Autochthonous Mice
Authors: Hosokawa Masuo , Yabiku Takashi , Ikeda Jun‐ichi , Sawamura Yutaka , Okada Futoshi , Komatsumoto Masashi , Tanabe Tatsuzo , Kobayashi Hiroshi
Published: August 2005

We have investigated the therapeutic effects of a combination of cyclophosphamide (CY, 150 mg/kg, iv) and human recombinant interleukin 2 (IL‐2, 5 × 104 JU/day, ip for 5 days) on autochthonous tumors induced in mice by 3‐methylcholanthrene. The initial treatment was carried out when the tumor had reached 8 to 10 mm in diameter. Twenty‐eight out of 35 mice (80%) died of local recurrence and pulmonary metastasis of tumor cells within 53 × 40 days (mean survival time, MST × SD) after the surgical removal of the primary tumor. When these mice were treated with both CY and IL‐2 following the operation (Op), only 10 out of 20 mice (50%) died of recurrence and metastasis. The survival rate, however, was not improved by CY chemotherapy alone or IL‐2 immnnotherapy alone, although each provided a prolongation of the MST. Natural killer cell and LAK precursor cell activities in the spleen cells from the treated mice were found to be restored by IL‐2 alone or CY + IL‐2, whereas they were suppressed by CY alone. These findings reveal that the restoration of the antitumor activity of spleen cells does not provide an improved therapeutic effect by itself and that IL‐2 immunotherapy requires the associated effect of CY chemotherapy to achieve an improved therapeutic effect.
A gag‐env Hybrid Protein of Human T‐cell Leukemia Virus Type I and Its Application to Serum Diagnosis
Authors: Kuga Tetsuro , Yamasaki Motoo , Sekine Susumu , Fukui Masanori , Yokoo Yoshiharu , Itoh Seiga , Yoshida Mitsuaki , Hattori Toshio , Takatsuki Kiyoshi
Published: August 2005

A fused gene of the gag and env sequences of human T‐cell leukemia virus type I (HTLV‐I), the causative agent of adult T‐cell leukemia, was constructed in vitro and expressed in Escherichia coli. The gag‐env hybrid protein accumulated as insoluble granules with a yield of approximately 12% of the total proteins. In an enzyme‐linked immunosorbent assay done with the use of the gag‐env hybrid protein, all 57 seropositive sera gave positive signals, and none of the sera from normal persons did. This system can produce large quantities of the gag‐env hybrid protein, which can be used for mass screening of human sera for HTLV‐I infection.
Murine Liver Metastasis Model Using L5178Y‐ML Lymphoma and the Effect of Antitumor Agents on the Metastasis
Authors: Watanabe Yoshinori , Okura Akira , Naito Kyozo , Kobayashi Masahiko
Published: August 2005

A reproducible tumor model for liver metastasis has been developed from murine L5178Y lymphoma line by sequential cycles of subcutaneous inoculation of liver tumor cells, that were originally generated in livers of female (BALB/c × DBA/2)F1 mice by injecting the parental cells into the tail vein. This variant (L5178Y‐ML) metastasized predominantly to the liver after intravenous or subcutaneous injection. The livers of the animals killed 9 days after intravenous implantation of 5 × 105 tumor cells were about 3 times the weight of control livers. All tumor‐bearing mice died 10 to 12 days after inoculation. Subcutaneous implantation of L5178Y‐ML in the side flank of mice induced metastatic nodules spontaneously in the livers. The tumor cells proliferated more in livers than in the implanted sites, compared with the parental L5178Y cells. The effects of 5‐fluorouracil, mitomycin C, cis‐platinum and doxorubicin on the liver metastasis of L5178Y‐ML were examined at subtoxic doses; 5‐fluorouracil was the most effective in both inhibiting the tumor growth in livers and prolonging the survival period of mice. This model provides a useful tool for the experimental therapy of hepatic tumors in mice.
Impairment of Methotrexate (MTX)‐Polyglutamate Formation of MTX‐resistant K562 Cell Lines
Authors: Koizumi Shoichi
Published: August 2005

We examined the mechanism of methotrexate (MTX) resistance in five K562 cell subclones resistant to MTX. Based on a clonogenic assay, the IC50s of these MTX‐resistant clones were 10 to 40μMMTX, indicating 2,000 to 5,000‐fold resistance as compared to that of the parent cell line. The doubling times of these MTX‐resistant K562 cell lines are longer (27–60 hr) than that of the parent K562 cell line (24 hr). One‐hour MTX accumulation in the resistant cells was 70–80% of that in parent cells. To investigate the formation of MTX‐polyglutamates (MTX‐PGs), resistant cells were incubated with 3H‐MTX (1 or 1OμM) for 24 hr in the presence of thymidine and deoxyinosine to prevent cytotoxicity. MTX (‐Glu1) and the polyglutamate metabolites (MTX‐Glu2, ‐Glu3, ‐Glu4 and ‐Glu5) were analyzed by a high‐pressure liquid chromatography (HPLC) technique. After a 24‐hr incubation with 10μM MTX, the total concentration of intracellular MTX reached 39 to 89 nmol/g protein, only 20 to 40% of the MTX level of the parent K562 cells. The HPLC analysis revealed that less than 2% of intracellular MTX was in the form of high‐molecular MTX‐PGs (MTX‐Glu3, ‐Glu4 and ‐Glu5) in the five MTX‐resistant K562 cell lines, while in the parent cells MTX‐Glu3–5 comprised 46% of the total intracellular MTX. These data indicate the possibility that impairment of MTX‐PG formation, with transport alteration, may be a special mechanism for the high level of resistance to this agent in human leukemic cells.
Vincristine‐resistant Human Cancer KB Cell Line and Increased Expression of Multidrug‐resistance Gene
Authors: Kohno Kimitoshi , Kikuchi Junko , Sato Shin‐ichi , Takano Hiroshi , Saburi Yoshio , Asoh Kuni‐ichi , Kuwano Michihiko
Published: August 2005

A multidrug‐resistant clone of human cancer KB cells was isolated by stepwise selection on exposure to increasing doses of vincristine. The final clone, VJ‐300, obtained after ethylmethane sulfonate mutagenesis showed 400‐fold higher resistance to vincristine than did KB cells. Cellular accumulation of vincristine in VJ‐300 was decreased to less than one‐tenth of that in KB. The cells were also cross‐resistant to daunomycin, adriamycin, actinomycin D, colchicine and VP‐16. During continuous culturing in the absence of any drug for several months, a different colchicine‐resistant and multidrug‐resistant clone, KB‐C1, reverted almost completely to drug sensitivity, whereas drug resistance in VJ‐300 was stably maintained. Amplification of the multidrug‐resistance‐1 (mdr‐1) gene was more than 20‐fold in KB‐C1, but less than 2‐fold in VJ‐300, mdr‐1 mRNA was, however, expressed in VJ‐300 at a rate comparable to KB‐C1. Acquisition of high multidrug resistance in VJ‐300 might be correlated with both activated transcription of mdr‐1 gene and amplification.
HETEROTRANSPLANTATION OF ARGYROPHIL SMALL CELL CARCINOMA OF THE UTERINE CERVIX INTEGRATING HPV16 DNA INTO NUDE MICE
Authors: Ichimura Hiroshi , Yamasaki Masato , Yamane Tetsumi , Shimizu Hiromu , Katsumoto Tetsuo , Kurimura Osamu , Kurimura Takashi
Published: August 2005

Argyrophil small cell carcinoma of the uterine cervix (ASCC) containing human papillomavirus type 16 (HPV16) DNA has been successfully transplanted in nude mice for the first time, and we have designated the resultant cell line as YIK‐1. Histology of YIK‐1 was similar to that of the original tumor. The original and YIK‐1 tumor cells contained argyrophil granules and neurosecretory granules in the cytoplasm, and were immunohistochemically stained positive for neuron‐specific enolase, serotonin and chromogranin. Both tumors contained HPV16 DNA in a multiple‐copy integrated form. Thus, YIK‐1 maintains the characteristics of the original ASCC, and may therefore be useful as an animal system for experimental studies of ASCC.