bluuebunny/crossref_metadata_2025 huggingface dataset:
Caspase-3 Cleavage and Nuclear Localization of Caspase-Activated DNase in Human Temporal Lobe Epilepsy
Authors: Schindler Clara K , Pearson Erik G , Bonner Helena P , So Norman K , Simon Roger P , Prehn Jochen HM , Henshall David C
Published: August 2005

Programmed cell death (apoptosis) signaling pathways have been implicated in seizure-induced neuronal death and the pathogenesis of human temporal lobe epilepsy (TLE). End-stage DNA fragmentation during cell death may be mediated by nucleases including caspase-activated DNase (CAD), apoptosis-inducing factor (AIF) and endonuclease G. In the present study, we investigated the subcellular localization of these nucleases in resected hippocampus from TLE patients and autopsy controls. Subcellular fractionation determined levels of CAD were significantly higher in the nuclear fraction of TLE samples compared with controls, and semiquantitative immunohistochemistry revealed cleaved caspase-3 positive cells in TLE sections but not controls. While mitochondrial levels of AIF and endonuclease G were higher in TLE samples than controls, nuclear localization of AIF was limited and restricted to cells that were negative for cleaved caspase-3. Nuclear accumulation of endonuclease G was not found in TLE samples. These data support ongoing caspase-dependent apoptosis signaling in human TLE and suggest that interventions targeting such pathways may have potential as adjunctive neuroprotective therapy in epilepsy.
Onset of slow dynamics in difluorotetrachloroethane glassy crystal
Authors: Affouard F. , Cochin E. , Danède F. , Decressain R. , Descamps M. , Haeussler W.
Published: August 2005

Complementary neutron spin-echo and x-ray experiments and molecular-dynamics simulations have been performed on difluorotetrachloroethane (CFCl2–CFCl2) glassy crystal. Static, single-molecule reorientational dynamics and collective dynamics properties are investigated. Our results confirm the strong analogy between molecular liquids and plastic crystals. The orientational disorder is characterized at different temperatures and a change in the nature of rotational dynamics is observed. A careful check of the rotational diffusion model is performed using self-angular correlation functions Cl with high l values and compared to results obtained on molecular liquids composed of A-B dumbbells. Below the crossover temperature at which slow dynamics emerge, we show that some scaling predictions of the mode coupling theory hold and that α-relaxation times and nonergodicity parameters are controlled by the nontrivial static correlations.
Metastable defect migration under high carrier injection in hydrogenated amorphous silicon p-i-n solar cells
Authors: Dutta U. , Chatterjee P. , Tchakarov S. , Uszpolewicz M. , Roca i Cabarrocas P.
Published: August 2005

The evolution of excess defects in hydrogenated amorphous silicon p-i-n solar cells, induced by a forward current in the dark, has been studied by modeling their measured dark and illuminated current-voltage and quantum efficiency characteristics at different stages of degradation. Our electrical-optical model is based on the solution of Poisson’s and continuity equations. Modeling reveals that metastable defects are mainly produced in regions where tail-to-tail recombination of injected electrons and holes is high. These regions are characterized by either high defect density or low electric field. Simulation of experimental characteristics after 1h of current injection indicates that the spatial generation of current-induced defects is highly nonuniform, with the main defect formation occurring near the p∕i interface, and to a lesser extent towards the n∕i interface. Few defects are generated over the bulk intrinsic layer. Modeling of the characteristics after a longer duration of current injection indicates a broadening of the current-induced defect zone from the interfaces to the bulk intrinsic layer. After prolonged current injection, the density of excess dangling-bond defects in the bulk intrinsic layer increases significantly, while the defect density near the p∕i interface actually decreases, resulting in a more uniform distribution of excess metastable defects. Evidence from modeling suggests that some metastable defects have migrated from the interfaces towards the bulk. We thus conclude that prolonged current injection not only produces excess metastable defects, but also causes these defects to migrate to regions of lower defect density.
Simulation and testing of a graded negative index of refraction lens
Authors: Greegor R. B. , Parazzoli C. G. , Nielsen J. A. , Thompson M. A. , Tanielian M. H. , Smith D. R.
Published: August 2005

A gradient index (GRIN) lens using a negative index of refraction material (NIM) has been designed and tested. The GRIN lens was fabricated using a NIM slab with a variable index of refraction perpendicular to the propagation direction. Ray tracing calculations based on the isotropic Eikonal equation determined the index of refraction gradient required for a given focal length. An electromagnetic code was then used to design the required ring and wire unit cells. Finally, the index of refraction was approximated using ten discrete steps in an effective medium simulation for the GRIN lens that agreed with the experimental measurements.
Listeria monocytogenes
phosphatidylinositol-specific phospholipase C has evolved for virulence by greatly reduced activity on GPI anchors
Authors: Wei Zhengyu , Zenewicz Lauren A. , Goldfine Howard
Published: August 2005

Listeria monocytogenes
phosphatidylinositol-specific phospholipase C (PI-PLC) plays a critical role in escape of this human pathogen from host cell vacuoles. Unlike classical bacterial PI-PLCs, the
L. monocytogenes
enzyme has very weak activity on glycosylphosphatidylinositol (GPI)-anchored proteins. Previous crystal structure analysis has revealed that a small β-strand (Vb) is present in
Bacillus cereus
PI-PLC and is absent in the enzyme from
L. monocytogenes
. This Vb β-strand in
B. cereus
PI-PLC forms contacts with the glycan linker of GPI anchors, which presumably increases its activity on GPI-anchored proteins. In this study, we show that, of all known bacterial PI-PLCs, those from listeriae are the only ones that lack the β-strand. Expression by
L. monocytogenes
of
B. cereus
PI-PLC, which has strong activity on GPI-anchored proteins, inhibited bacterial escape from a vacuole and cell-to-cell spread, resulting in greatly reduced virulence in mice. Deletion of the Vb β-strand from
B. cereus
PI-PLC abolished its ability to cleave GPI-anchored proteins, decreased its inhibitory effects, and increased its virulence in mice. These results strongly suggest that
L. monocytogenes
PI-PLC has evolved as an important determinant of
L. monocytogenes
pathogenesis by absence of the Vb β-strand, thus leading to greatly reduced activity on GPI-anchored proteins.
The evolution of network topology by selective removal
Authors: Salathé Marcel , May Robert M , Bonhoeffer Sebastian
Published: August 2005

The topology of large social, technical and biological networks such as the World Wide Web or protein interaction networks has caught considerable attention in the past few years (reviewed in
Newman 2003
), and analysis of the structure of such networks revealed that many of them can be classified as broad-tailed, scale-free-like networks, since their vertex connectivities follow approximately a power-law. Preferential attachment of new vertices to highly connected vertices is commonly seen as the main mechanism that can generate scale-free connectivity in growing networks (
Watts 2004
). Here, we propose a new model that can generate broad-tailed networks even in the absence of network growth, by not only adding vertices, but also selectively eliminating vertices with a probability that is inversely related to the sum of their first- and second order connectivity.
Semaphorins: a new class of immunoregulatory molecules
Authors: Takegahara Noriko , Kumanogoh Atsushi , Kikutani Hitoshi
Published: August 2005

The immune and nervous systems play distinct roles in maintaining physiological homeostasis. Recent data indicates that these systems influence one another and share many proteins and pathways that are essential for their normal function and development. Molecules originally shown to be critical for the development of proper immune responses have recently been found to function in the nervous system. Conversely, neuronal guidance cues can modulate immune functions. Although semaphorins were originally identified as axon guidance factors active during neuronal development, several recent studies have identified indispensable functions for these molecules in the immune system. This review provides an overview of the rapidly emerging functions of semaphorins and their receptors in the immune system.
CIRCULATING SURFACTANT PROTEIN‐B LEVELS INCREASE ACUTELY IN RESPONSE TO EXERCISE‐INDUCED LEFT VENTRICULAR DYSFUNCTION
Authors: De Pasquale Carmine G , Arnolda Leonard F , Doyle Ian R , Aylward Phillip E , Russell Andrew E , Bersten Andrew D
Published: August 2005

1. As a result of its enormous surface area and necessary thinness for gas exchange, the alveolocapillary barrier is vulnerable to mechanical disruption from raised pulmonary microvascular pressure (Pmv).

2. Because surfactant protein‐B (SP‐B) leaks into the blood stream from the alveoli in response to alveolocapillary barrier damage and exercise leads to increased Pmv, we sought to determine whether exercise results in increased plasma SP‐B. Moreover, in the setting of exercise‐induced left ventricular dysfunction, the consequent increase in left heart filling pressure and, therefore, Pmv would be expected to further increase plasma SP‐B levels.

3. Twenty consecutive subjects referred for treadmill exercise stress echocardiography (ESE) had venous blood sampled immediately before and after ESE for batch atrial natriuretic peptide (ANP) and SP‐B assay. Echocardiographic measures of pulmonary haemodynamics (pulmonary artery flow acceleration time (pafAT) and right ventricular outflow tract velocity time integral (rVTI)) were also taken pre‐ and post‐exercise.

4. Although circulating ANP levels increased following exercise (P < 0.001), there was no change in circulating SP‐B levels in the entire cohort.

5. Ten subjects had a positive ESE for ventricular dysfunction. Although circulating ANP was increased post‐exercise in both the negative and positive ESE groups (P < 0.05 and P < 0.01, respectively), circulating SP‐B only increased post‐exercise in the positive ESE group (P < 0.05). Echocardiographic parameters supported an increment in Pmv in the cohort with exercise‐induced left ventricular dysfunction because this group had an increase in pafAT (P < 0.05; reflecting pulmonary artery pressure) and no change in rVTI.

6. Physical exertion associated with a Bruce protocol ESE is insufficient to increase circulating SP‐B, despite evidence of increased left atrial and pulmonary vascular pressure. However, in the setting of exercise‐induced myocardial dysfunction, there is a detectable increase in circulating SP‐B.

7. The exaggerated increase in pulmonary vascular pressure in exercise‐induced myocardial dysfunction may result in increased SP‐B leakage from the alveoli into the circulation by altering the integrity of the alveolocapillary barrier to protein.
IMPROVEMENT OF INSULIN RESISTANCE BY ACANTHOPANAX SENTICOSUS ROOT IN FRUCTOSE‐RICH CHOW‐FED RATS
Authors: Liu Tsang‐Pai , Lee Chyou‐Shen , Liou Shorong‐Shii , Liu I‐Min , Cheng Juei‐Tang
Published: August 2005

1. In an attempt to develop new substances for handling insulin resistance, an aqueous extract of the root of Acanthopanax senticosus (Araliaceae) was used to screen the effect on insulin resistance induced by fructose‐rich chow in rats.

2. Insulin action on glucose disposal rate was measured using the glucose–insulin index, the product from areas under the curve of glucose and insulin during the intraperitoneal glucose tolerance test. In addition to the modification of feeding behaviour and a marked decrease in bodyweight, oral administration (three times daily for 3 days) of the aqueous extract of A. senticosus root to rats that had received fructose‐rich chow for 4 weeks reversed the elevated value of the glucose–‐insulin index, indicating that this herb has the ability to improve insulin sensitivity.

3. Time for the loss of the plasma glucose‐lowering response to tolbutamide (10.0 mg/kg, i.p.) in fructose‐rich chow‐fed rats was markedly delayed by repeated treatment with the aqueous extract of A. senticosus root compared with the vehicle (saline) ‐treated group. Thus, an improving effect of A. senticosus root on insulin resistance can be considered.

4. An increase in insulin sensitivity following the administration of this herb was further identified using the plasma glucose‐lowering action of exogenous insulin in streptozotocin (STZ)‐diabetic rats. Oral administration of the aqueous extract of A. senticosus root at a dose of 150.0 mg/kg three times daily to STZ‐diabetic rats increased the responses to exogenous insulin 10 days later.

5. The results obtained suggest that oral administration of the aqueous extract from A. senticosus root has the ability to improve insulin sensitivity and delay the development of insulin resistance in rats and, thus, may be used as an adjuvant therapy for patients with insulin resistance.
DELAYED UNCOUPLING CONTRIBUTES TO THE PROTECTIVE EFFECT OF HEPTANOL AGAINST ISCHAEMIA IN THE RAT ISOLATED HEART
Authors: Chen Bao‐Ping , Mao Hong‐Jiao , Fan Fang‐Yan , Bruce Iain C , Xia Qiang
Published: August 2005

1. It is known that infusion of the gap junction uncoupler heptanol, before ischaemia or during reperfusion, limits myocardial infarct size. However, whether this cardiac effect is linked to the effect of hepatnol on communication across gap junctions has not been elucidated. The aims of the present study were to examine the effect of heptanol on infarct size, arrhythmias and myocardial tissue resistance and to assess whether changes in electrical coupling correlate with cardiac protection.

2. Rat isolated, perfused hearts were subjected to a 24 min infusion of heptanol (0.05, 0.1, 0.5 or 1.0 mmol/L) followed by 20 min regional ischaemia and 60 min reperfusion, or by 70 min global no‐flow ischaemia. The effective refractory period, action potential and conduction velocity were measured in papillary muscles from the right ventricle. Heptanol markedly decreased arrhythmia scores during ischaemia and reperfusion, as well as reducing infarct size to a degree similar to that induced by ischaemic preconditioning. In the prolonged ischaemia model, heptanol delayed the onset of uncoupling, increased time to plateau and decreased the maximal rate of uncoupling during ischaemia. Ischaemic preconditioning had similar effects on these parameters. In papillary muscle, heptanol reduced the conduction velocity of the action potential in a dose‐dependent manner, but had no significant effect on resting potential, action potential amplitude, action potential duration, maximal upstroke of depolarization or effective refractory period.

3. These results demonstrate that treatment with the gap junction uncoupler heptanol confers cardioprotection against ischaemia and this effect is related to delayed electrical uncoupling during prolonged ischaemia.
Nest sites, nest depredation, and productivity of avian broods in a primeval temperate forest: do the generalisations hold?
Authors: Wesolowski Tomasz , Tomialojc Ludwik
Published: August 2005

Data on nest success and brood productivity of three ground‐nesting, three canopy‐nesting and four hole‐nesting (non‐excavator) passerines were gathered in a primeval lowland temperate forest (Bialowieza National Park, E Poland). Natural holes were superabundant and the birds had to cope with a heavy pressure of a diverse assemblage of nest predators. We tested whether in such conditions nesting in holes is more productive, and whether nesting on the ground is most risky, as expected from some earlier generalisations. The nesting success varied significantly across the nest types. As predicted, the success of hole‐nesters (51–74%) and their brood productivity were the highest. Contrary to expectations, the ground‐nesters (27–40%) did not breed less successfully than the canopy‐nesters (22–33%). Nest predators, responsible for 64–94% of nest losses in individual species, were the major cause of the differences among nest types. The Bialowieza results confirm the long‐held view that holes tend to be the safest breeding places, but lend no support for the idea that nesting on the ground is more dangerous than in tree crowns.
Detection of Guanine‐C8‐2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine Adduct as a Single Spot on Thin‐layer Chromatography by Modification of the 32P‐Postlabeling Method
Authors: Fukutome Kazuo , Ochiai Masako , Wakabayashi Keiji , Watanabe Shinya , Sugimura Takashi , Nagao Minako
Published: August 2005

N‐(Deoxyguanosin‐8‐yl)‐2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (dG‐C8‐PhIP) has been shown to be a major adduct in DNA of rats given [3H]PhIP. However, when DNA from organs of rats fed PhIP was analyzed by the 32P‐postlabeling method under standard and adduct‐intensification conditions, four adduct spots were observed, and 3′,5′‐pdGp‐C8‐PhIP was detected as a minor, not a major, adduct spot. Since the three other major adduct spots were suspected to be those of adducted di‐ or oligo‐nucleotides, the 32P‐labeled samples were further treated with nuclease PI and phosphodiesterase I and found to yield only a single adduct spot. The material in this adduct spot was confirmed to be 5′‐pdG‐C8‐PhIP, Thus, using this newly modified 32P‐postlabeling method, dG‐C8‐PhIP was detected as a major adduct in DNA of rats given PhIP.
Expression of cripto in Human Pancreatic Tumors
Authors: Tsutsumi Masahiro , Yasui Wataru , Naito Azusa , Ohashi Kazuo , Kobayashi Eisaku , Noguchi Osamu , Horiguchi Kohsuke , Okita Shunji , Tsujiuchi Toshifumi , Kitada Hiromichi , Ishikawa Osamu , Tahara Eiichi , Konishi Yoichi
Published: August 2005

The expression of cripto gene product was examined immunohistochemically in 45 surgically resected pancreatic tumors, including 32 invasive ductal carcinomas, 4 intraductal papillary adenocarcinomas, 4 intraductal papillary adenomas, 2 mucinous cystadenomas, 2 islet cell tumors, and one solid and cystic tumor, and compared with that in 32 areas of accompanying chronic pancreatitis present in the cases of invasive ductal carcinomas and 5 non‐tumorous areas of pancreas without pancreatitis. All pancreatic ductal tumors including adenomas and carcinomas showed positive staining with no difference in terms of staining intensity among intraductal tumors and invasive carcinomas with or without mucin hypersecretion. Islet cell tumors were positively stained but the solid and cystic tumor was negative. Duct epithelial cells and acinar cells were negative but islet cells were positive in the pancreas tissues without pancreatitis. Cells arranged in duct‐like structures in areas of accompanying chronic pancreatitis were positively stained. The results suggest that cripto expression might be associated with a growth advantage of tumor cells and also with differentiation to form duct‐like structures.
Telomere Reduction of Specific Chromosome Translocation in Acute Myelocytic Leukemia
Authors: Takauchi Katsuhiko , Tashiro Satoshi , Ohtaki Megu , Kamada Nanao
Published: August 2005

The length of telomere restriction fragments (TRF) was studied by Southern blotting in 42 patients with acute myelocytic leukemia (AML) including 15 patients with 8;21 translocation, 8 with 15;17 translocation and 19 with a normal karyotype. The TRF length of leukemic cells with a normal karyotype and with 8;21 or 15;17 translocation showed significant reduction compared to that of lymphocytes from normal individuals (P<0.05). In addition, there was a statistically significant difference in TRF length between leukemic cells with a normal karyotype and 8;21 translocation (P<0.05). Therefore, the significant difference of telomere reduction in 8;21 translocation may be an important factor in the leukemogenic process.
Autonomous Expressions of Cytokine Genes by Human Lung Cancer Cells and Their Paracrine Regulation
Authors: Mizuno Kazuto , Sone Saburo , Orino Etsuko , Nii Akihiko , Ogura Takeshi
Published: August 2005

Cell‐to‐cell interaction between tumors and host inflammatory cells is important for the subsequent cancer progression or regression. We examined the expressions of mRNAs for various proinflammatory cytokines by nine human lung cancer cell lines and the influences of cytokines on their gene expressions. The cytokines used were interleukin 1β (IL‐1β), interleukin 6 (IL‐6), tumor necrosis factor α (TNF‐α), granulocyte‐macrophage colony stimulating factor (GM‐CSF) and monocyte chemotactic and activating factor. Gene expressions of cytokines were measured by Northern blot analysis. Substantial expressions of cytokine genes were detected in several lung cancer cell lines such as RERF‐LC‐MS, RERF‐LC‐OK and VMRC‐LCD, although the levels of expression of each cytokine varied in different cell lines. Four lung cancer cell lines (RERF‐LC‐MS, RERF‐LC‐OK, A549 and YO‐88) were used to examine the effects of exogenous cytokines (IL‐1β, TNF‐α and GM‐CSF) on cytokine gene expressions by the cells. TNF‐α and IL‐1β caused significant changes in the levels of mRNA expressions of certain cytokines. Moreover, on stimulation with TNF‐α, RERF‐LC‐OK cells produced IL‐6 extracellularly. These extensive differences in the levels of gene expressions and productions of cytokines could have profound effects on the interactions between human lung cancer cells and the corresponding host cells.
Sequential Decrease in Tight Junctions as Revealed by 7H6 Tight Junction‐associated Protein during Rat Hepatocarcinogenesis
Authors: Zhong Yun , Enomoto Katsuhiko , Tobioka Hirotoshi , Konishi Yasuhiro , Satoh Masaaki , Mori Michio
Published: August 2005

A sequential decrease in the number of hepatocyte tight junctions during the course of rat hepatocarcinogenesis was demonstrated by immunohistochemistry with a new 7H6 monoclonal antibody generated in our laboratory. Semiqnantitative analysis by confocal laser scanning microscopy revealed that the expression of 7H6 antigen was reduced in hyperplastic foci, hyperplastic nodules and hepatocellular carcinomas (HCC) to 43%, 28% and 25%, respectively, compared to corresponding normal liver tissues. 7H6 antigen was scarce in HCC with a trabecular pattern, whereas it was expressed intensely at the apical and basolateral membrane of HCC with a glandular pattern. Immunoblot analysis of 7H6 expression in hepatocellular carcinomas showed a decrease roughly coincident with that shown by immunohistochemistry. These results indicated, for the first time, that tight junctions decrease progressively during carcinogenesis, leading to disruption of cellular polarity and cellular adhesiveness.
Correlation between Tumorigenicity and Expression Levels or Splicing Patterns of Transcripts of the Human Papillomavirus Type 16 E6 Gene
Authors: Inoue Tadao , Kyo Satoru , Kiyono Tohru , Ishibashi Masahide , Ishiwatari Haruko , Hwang Yong‐II , Yutsudo Masuo , Hakura Akira
Published: August 2005

For determination of the correlation between tumorigenicity and the expression levels or splicing patterns of E6 mRNAs of the human papillomavirus type 16 in established cells, a vector containing the intact E6 open reading frame which expresses both unspliced and spliced mRNAs, one expressing only unspliced E6 mRNA, and one expressing both unspliced and spliced mRNAs but producing only truncated E6 proteins were constructed. In transformation assays and analyses of E6 mRNAs, a higher expression level of unspliced E6 mRNA was found to be closely associated with tumorigenicity. Furthermore, it was also related with anchorage‐independent growth and a decreased serum requirement of the cells.
Modulation of Growth Factor Receptors on Acute Myeloblastic Leukemia Cells by Retinoic Acid
Authors: Tohda Shuji , Minden Mark D.
Published: August 2005

The effects of retinoic acid (RA) on the proliferation of acute myeloblastic leukemia (AML) cells were studied. AML samples were divided into three groups. Namely, RA stimulated blast colony formation by AML samples in group A and inhibited that by the samples in group B, regardless of added growth factors. For the samples in group C, RA inhibited the colonies formed by granulocyte colony‐stimulating factor (G‐CSF) but stimulated those by granulocyte macrophage CSF (GM‐CSF). To investigate the mechanism involved, the effects of RA on growth factor receptors on AML cells were examined by flow cytometry using fluorolabeled ligands. For the samples in groups A and B, RA affected neither G‐CSF receptor (GR) nor GM‐CSF receptor (GMR). For the samples in group C, exposure to 10−7 MRA for 1 day clearly increased GMR, but did not affect GR. This finding supports the hypothesis that the increase of GMR is one of the causes of the stimulative effects of RA on cells cultured with GM‐CSF in group C.
Lethal Midline Granuloma in Okinawa with Special Emphasis on Polymorphic Reticulosis
Authors: Kojya Shizuo , Itokazu Tetsuo , Maeshiro Norihide , Esu Hiroaki , Noda Yutaka , Mishima Kenji , Ohsawa Masahiko , Aozasa Katsuyuki
Published: August 2005

Lethal midline granuloma (LMG) is a clinical term used to describe a condition which may be manifested histologically as Wegener's granulomatosis (WG), polymorphic reticulosis (PR), and malignant lymphoma (ML). WG is an inflammatory disease, and PR and ML are considered to represent a neoplastic proliferation of lymphoreticular cells. In this report, twenty‐two cases of LMG in Okinawa were examined. The frequency of LMG per 100,000 outpatients of the ear, nose and throat clinic in Okinawa was 67, and the higher frequency of PR (27) and ML (34) in Okinawa than in other districts of Japan was characteristic. Polymerase chain reaction, in situ hybridization, and immunohistochemical studies showed that the proliferating cells in PR were CD43+ and simultaneously contained Epstein‐Barr viral genome in their nuclei. The higher frequency of PR and ML in Okinawa is discussed in conjunction with a review of pertinent literature: multiple factors including genetic, viral environmental, and socioeconomic factors seem to affect the frequencies of these diseases.
A Novel Antitumor Antibiotic, KW‐2189 Is Activated by Carboxyl Esterase and Induces DNA Strand Breaks in Human Small Cell Lung Cancer Cells
Authors: Ogasawara Hayato , Nishio Kazuto , Takeda Yuichiro , Ohmori Tohru , Kubota Naohiro , Funayama Yasunori , Ohira Tatsuo , Kuraishi Yasunobu , Isogai Yukihide , Saijo Nagahiro
Published: August 2005

KW‐2189 has been selected as a lead compound for clinical trial among duocarmycin derivatives with structural similarity to CC‐1065, a cyclopropylpyrroloindole. The purpose of this study was to examine the DNA‐binding potency and the mechanisms of cytotoxicity of KW‐2189. In order to analyze DNA‐binding activity of KW‐2189, plasmid pBR322 was treated with KW‐2189 with or without pretreatment with carboxyl esterase, which we demonstrated to be an activating enzyme, and the products were examined by agarose gel electrophoresis and restriction enzyme analysis. Cytotoxic activity was examined by exposing a human small cell lung cancer cell line, NCI‐H69 to KW‐2189 with or without carboxyl esterase. Alkaline elution was performed to examine whether KW‐2189 induces DNA strand breaks. DNA treated with KW‐2189 and carboxyl esterase migrated faster than KW‐2189‐treated DNA, which migrated at the same rate as untreated DNA. In addition DNA treated with esterase‐activated KW‐2189 was protected from digestion by some restriction enzymes. KW‐2189 showed concentration‐ and time‐dependent growth inhibitory effect with IC50 values (drug concentration required for 50% growth inhibition) of 58 nM (96 h) to 1900 nM (1 h) in H69 cells. The IC50 values of 4‐h exposure of H69 to KW‐2189 with 0, 26, 130, 650 mU/ml carboxyl esterase were 460, 120, 30, and 7 nM, respectively. Time‐dependent enhancement of cytotoxicity by carboxyl esterase was also observed. KW‐2189 induced DNA strand breaks in H69 cells in a concentration‐dependent manner around the IC50 value. We conclude that 1) KW‐2189 is activated by carboxyl esterase to its active form(s), 2) activated KW‐2189 has a stronger DNA‐binding activity and cytotoxicity than KW‐2189, 3) DNA cleavage is one of the major mechanisms of KW‐2189‐mediated cytotoxicity.
p53 Gene Mutation in Hepatocellular Carcinoma Induced by 2‐Amino‐3‐methylimidazo[4,5‐f]quinoline in Nonhuman Primates
Authors: Fujimoto Yoshinori , Hampton Lori L. , Snyderwine Elizabeth G. , Nagao Minako , Sugimura Takashi , Adamson Richard H. , Thorgeirsson Snorri S.
Published: August 2005

2‐Amino‐3‐methylimidazo[4,5‐f]quinoline (IQ) is one of several heterocyclic amines formed during the cooking of proteinaceous foods. IQ is a potent carcinogen in rodent bioassays and causes a high incidence of hepatocellular carcinomas in nonhnman primates. We examined 20 hepatocellular carcinomas (HCCs) from nonhuman primates for mutations of the p53 gene using polymerase chain reaction‐single strand conformational polymorphism analysis. Mutations in the p53 gene were detected in 4 of 20 HCCs (20%) with 3 showing G‐to‐T transversions and one a G‐to‐A transition. Three of these mutations were observed in codons 175 and 248 that are known mutational hot spots in human cancers. These data indicate that part of the IQ‐induced HCCs in nonhuman primates may involve inactivation of the p53 gene and suggest that IQ and possibly other heterocyclic amines may participate in human carcinogenesis by a similar mechanism.
Existence of Lipoprotein Lipase in Human Sarcomas and Carcinomas
Authors: Sakayama Kenshi , Masuno Hiroshi , Miyazaki Tatsuhiko , Okumura Hideo , Shibata Taihoh , Okuda Hiromichi
Published: August 2005

Aqueous extracts of acetone/ether powders of surgically obtained specimens of human tumors hydrolyzed 3H‐labeled triolein in a dose‐dependent manner. The lipolytic activity in these extracts was inhibited by anti‐lipoprotein lipase (LPL) IgG dose‐dependently, 25 μg of anti‐LPL IgG causing 95% inhibition of the activity. Thus, LPL accounts for most of the lipolytic activity in extracts of acetone/ether powders of the tumors. All sarcomas and carcinomas examined contained LPL activity. Western blotting showed that they gave a band corresponding to that of human adipose tissue LPL (Mr=57,000). Immunocytochemical studies showed that LPL was present in cultured human osteosarcoma cells and distributed throughout the cells. We determined the proliferating cell nuclear antigen (PCNA)‐labeling index as an indicator of the proliferative activity of tumor cells and measured LPL activity in extracts of tumors in areas corresponding to those used for determining the PCNA‐labeling index. In malignant fibrous histiocytomas, the PCNA‐labeling index in area a, which corresponds to the subcapsular region, was higher than that in area b, which corresponds to the central region. The LPL activity in area a was 10 times that in area b. In rectal cancer, the index in area c, which corresponds to the subserosal region, was higher than that in area d, which corresponds to the submucosal region. The LPL activity in area c was 1.9 times that in area d. These findings indicate heterogeneity in the distributions of LPL activity within tumors and higher levels of LPL activity in tumors that are proliferating actively.
Modulation of Adriamycin Resistance in Human Breast Carcinoma MCF‐7 Cells in vitro and in vivo by Medroxyprogesterone Acetate
Authors: Ishida Hiroyuki , Okabe Masami , Gomi Katsushige , Horiuchi Ryuya , Mikami Koji , Naito Mikihiko , Tsuruo Takashi
Published: August 2005

The combination effect of adriamycin (ADM) and medroxyprogesterone acetate (MPA) was examined in vitro against human breast carcinoma MCF‐7 and its ADM‐resistant line (MCF‐7/ADM). MCF‐7 cells, which are positive for estrogen receptors, progesterone receptors and high‐affinity MPA‐binding activity, were more susceptible to the growth‐inhibitory activity of ADM or MPA than MCF‐7/ADM cells. A combination effect of ADM and MPA was observed against MCF‐7/ADM cells, which are negative for steroid receptors, and furthermore against human nasopharynx carcinoma KB and its ADM‐resistant line KB‐A1. This combination effect of ADM and MPA against MCF‐7/ADM cells was demonstrated to be synergistic by using the median effect plot method. The activity of MPA was almost equivalent to that of chlormadinone acetate or tamoxifen, greater than that of progesterone, and less than that of verapamil. The accumulation of ADM in MCF‐7/ADM cells was enhanced by treatment with 10 μM MPA as well as 10 μM verapamil. The efflux of accumulated ADM from MCF‐7/ADM cells was also partially inhibited by treatment with MPA or verapamil. MPA augmented the growth‐inhibitory activity of ADM against MCF‐7/ADM tumors inoculated into nude mice, although statistical significance was not observed. It is suggested that the clinical advantage of the combination of MPA with ADM against advanced breast cancers may be partly explained by the modulation of ADM resistance by MPA.
Effects of Intravenous Infusion of Dopamine on Tumor Blood Flow in Rat Subcutis
Authors: Tanda Shigeru , Hori Katsuyoshi , Saito Sachiko , Zhang Qiu‐Hang , Li Hao‐Chuan , Suzuki Maroh
Published: August 2005

To determine the effects of intravenous administration of dopamine hydrochloride (DA) on tumor blood flow (TBF), we measured the blood flow of normal subcutaneous tissue and subcutaneous tumor (LY‐80, a variant of Yoshida sarcoma) in enflurane‐anesthetized male Donryu rats using a hydrogen clearance method. Measurements were made before and during intravenous infusion of DA at a rate of 5μg/kg/min, while recording the mean arterial blood pressure of the rats. Under mild hypertension induced by DA, the blood flow of normal subcutis decreased and TBF increased significantly. SCH‐23390, an antagonist of the DA1 receptor, inhibited the enhancement of TBF by DA; while domperidone, an antagonist of the DA2 receptor, did not modify the effects of DA. In experimental chemotherapy against the tumor using adriamycin (ADM) 5 mg/kg i.v., only the combination of DA and ADM significantly inhibited the tumor growth. Moreover, DA reduced the weight loss caused by ADM. These results indicate that DA could have a role in increasing TBF and possibly enhance drug delivery to tumors. Moreover, it appears that the DA1 receptor contributes, at least in part, to the enhanced blood flow in rat subcutaneous tumor following DA administration.
Spontaneous Renal Cell Tumors in Long‐Evans Cinnamon Rats
Authors: Izumi Keisuke , Kitaura Keisuke , Chone Yoshifumi , Tate Hideki , Nakagawa Tateo , Suzuki Yasuo , Matsumoto Kozo
Published: August 2005

Neoplastic lesions of the kidneys in untreated Long‐Evans Cinnamon (LEC) rats of 57–118 weeks old (85 males and 34 females) and male F344 rats of 64–93 weeks old (59 males) were examined histologically. The incidences of renal cell tumors in male and female LEC rats were 6/80 (8%) in weeks 57–65, 3/19 (16%) in weeks 66–75, 3/8 (38%) in weeks 76–105 and 7/12 (58%) in weeks 106–118. Of these tumors, 13 were microscopic adenomas and 7 were renal cell carcinomas. The copper content of the kidneys was about three times higher in LEC rats than in F344 rats (P<0.001), but the iron content of the kidneys was similar in the two strains.
Detection of Epidermal Growth Factor Receptor Gene Amplification in Human Squamous Cell Carcinomas Using Fluorescence in situ Hybridization
Authors: Shimizu Nobuyoshi , Wang Yimin , Minoshima Shinsei , Ishitoya Junichi
Published: August 2005

The gene for epidermal growth factor receptor (EGFR) is associated with development of certain human cancers. In this study, we employed the improved fluorescence in situ hybridization technique to detect EGFR gene amplification in cell lines and tissue sections from human squamous cell carcinomas. We detected multiple distinct signals as arrayed amplicons on metaphase chromosomes and interphase nuclei of tumor cells. Our results provide a basis for rapid and quantitative DMA diagnosis of the EGFR gene amplification in individual cells of tumor specimens.
Heterogeneity in B‐Cell Neoplasms Associated with Rearrangement of the LAZ3 Gene on Chromosome Band 3q27
Authors: Ohno Hitoshi , Kerckaert Jean‐Pierre , Bastard Christian , Fukuhara Shirou
Published: August 2005

The LAZ3 gene has been identified on chromosome band 3q27, which is the breakpoint of reciprocal chromosome translocations observed in B‐cell non‐Hodgkin's lymphoma (NHL). Although the translocations affect various chromosome sites including the immunoglobulin gene loci, molecular studies have indicated that the breakages are clustered within a 10‐kb‐long major translocation cluster region (MTC) at band 3q27. In the current study, we have used a genomic probe from the MTC to study 51 Japanese patients having B‐cell neoplasms with regard to rearrangement of LAZ3. The study detected rearrangement in 12 cases out of 51; the rearrangements occurred within a limited region close to the first exon of the LAZ3 gene. Eight cases out of 12 with rearrangement had diffuse large cell NHL and the immunoblastic variant, including one case transformed from a follicular lymphoma carrying the BCL2 rearrangement. However, the rearrangement was also identified in two NHL patients showing a follicular growth pattern, in one case with indolent chronic lymphocytic leukemia and in one case with high‐grade small noncleaved cell lymphoma with a bulky abdominal mass. Cytogenetic analysis revealed t(3;14)(q27;q32) in 2 cases, t(3;22)(q27;q11) in 3, and a newly identified translocation t(3;6)(q27;p21) in one case. LAZ3 expression was demonstrated in cells carrying the LAZ3 rearrangement, suggesting transcriptional deregulation of the gene. Our results are compatible with previous cytogenetic reports in which the 3q27 translocation was observed in 15–20% of NHL; however, patients with the LAZ3 rearrangements exhibited a wide range of clinico‐pathologic characteristics. Thus, there is no clear consistent association of the 3q27 translocation with a specific subtype of B‐cell neoplasm.
Cytotoxicity of Simvastatin to Pancreatic Adenocarcinoma Cells Containing Mutant ras Gene
Authors: Ura Hitoshi , Obara Takeshi , Nishino Noriyuki , Tanno Satoshi , Okamura Kiyoshi , Namiki Masayoshi
Published: August 2005

Simvastatin (SV), a 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitor, inhibits the synthesis of mevalonic acid. The dose‐dependent (0.1–100 μg/ml) cytotoxicity of SV towards human (MIAPaCa‐2, Panc‐1, HPC‐1, HPC‐3, HPC‐4, PK‐1, PK‐9) and hamster (T2) pancreatic carcinoma cell lines was determined by MTT assay. At up to 20 μg/ml of SV, the effect was reversible and was restored by 60 μg/ml mevalonic acid. Point mutation of Ki‐ras at codon 12 in each cell line was detected by means of the modified polymerase chain reaction. The concentration of SV necessary to achieve 50% cytotoxicity was about 10 μg/ml, and at this concentration of SV, DNA synthesis assayed in terms of [3H]thymidine uptake, isoprenylation of p21ras examined by Western blotting and cell progression from G1 to S phase of the cell cycle analyzed by flow cytometry were all inhibited. Isoprenylation inhibitors of p21ras, such as SV, are expected to be useful for the treatment of pancreatic cancer.
Oral Administration of BOF‐A2 to Rats with Lung Transplanted Tumors Results in Increased 5‐Fluorouracil Levels
Authors: Miyauchi Shun , Imaoka Takeshi , Utsunomiya Tadami , Hayashi Kazuhiko , Kubo Masanori , Kawaguchi Teruhisa , Matsui Yusaku
Published: August 2005

A new tumor model was developed in which solid Yoshida sarcoma tissue injected intravenously developed into tumors in the lungs of about 30% (13/42) of the inoculated rats. Histological examination revealed that alveoli were occupied with tumor cells and the tumors were similar to those obtained by subcutaneous inoculation. Using this model, the concentrations of 5‐fluorouracil (5‐FU) in tumor tissue 12 h after oral administration of 3‐[3‐(6‐benzoyloxy‐3‐cyano‐2‐pyridyloxycarbonyl)‐benzoyl]‐1‐ethoxymethyl‐5‐fluorouracil (BOF‐A2, 36 μmol/kg) or a combination of tegafur and uracil in a molar ratio 1 to 4 (UFT, 50 μmol/kg) were found to be 129.8 ng/g and 19.2 ng/g, respectively. Thus, compared to treatment with UFT, BOF‐A2 resulted in higher levels of 5‐FU in lung tumor tissues. Increased concentrations of 5‐FU should have a superior anti‐tumor effect and so BOF‐A2 merits clinical trial in the treatment of patients with lung cancer.
Interhospital Differences in Cancer Survival: Magnitude and Trend in 1975–1987 in Osaka, Japan
Authors: Tanaka Hideo , Hiyama Tomohiko , Hanai Aya , Fujimoto Isaburo
Published: August 2005

This study addresses the disparity in cancer survival rates among hospitals in Osaka, Japan, Using data from the Osaka Cancer Registry, four‐year survival rates for stomach cancer patients (n=8,845) diagnosed in 1976, 1981 and 1986, and lung cancer (n = 9,795) and breast cancer patients (n= 7,377) diagnosed in 1975–77, 1980–82 and 1985–87 were calculated according to four hospital categories (teaching hospitals, large hospitals: 400+ beds excluding teaching hospitals, medium‐size hospitals: 150–399 beds, and small hospitals: 20–149 beds). Cox's proportional hazards model was employed with adjustment for sex, age, clinical stage at diagnosis, and treatment status. Stomach and lung cancer patients treated in large, medium‐size and small hospitals showed significantly higher risks of death than those treated in teaching hospitals in 1975–87. Interhospital differences in breast cancer survival appeared to increase in 1975–87, whereas those in stomach and lung cancer survivals decreased during the same period.
Suppression of Azoxymethane‐induced Rat Colon Aberrant Crypt Foci by Dietary Protocatechuic Acid
Authors: Kawamori Toshihiko , Tanaka Takuji , Kojima Toshihiro , Suzui Masumi , Ohnishi Masami , Mori Hideki
Published: August 2005

The modifying effect of dietary exposure to protocatechuic acid (PCA) on the development of azoxymethane (AOM)‐induced colonic aberrant crypt foci (ACF) was investigated in male F344 rats. The effects of PCA feeding on the silver‐stained nucleolar organizer regions protein (AgNORs) count in the colonic epithelial cells and on the ornithine decarboxylase (ODC) activity in the colonic mucosa were also estimated. Animals were given weekly s.c. injections of AOM (15 mg/kg body weight) for 3 weeks to induce ACF. These rats were fed diet containing 1000 or 2000 ppm PCA for 5 weeks, starting one week before the first dosing of AOM. All rats were killed 2 weeks after the last AOM injection, to measure the number of ACF, ODC activity, and AgNORs count per nucleus in the colon. In rats given AOM and PCA, the frequency of ACF/colon was significantly decreased compared with that in rats given AOM alone (P< 0.005 at 1000 and P< 0.05 at 2000 ppm). ODC activity in the colon of rats given AOM and PCA at both doses was also significantly lower than that of rats treated with AOM alone (P< 0.05). Similarly, the mean AgNORs count in rats fed PCA was significantly smaller than that of rats treated with AOM alone (P< 0.0001). Treatment with PCA alone did not affect these three biomarkers. These results provide further evidence that PCA could be a chemopreventive agent against rat colon carcinogenesis.
Detection and Cloning of Human Papillomavirus DNA Associated with Recurrent Respiratory Papillomatosis in Thailand
Authors: Ushikai Masato , Fujiyoshi Toshinobu , Kono Motoko , Antrasena Soontorn , Oda Hiroshi , Yoshida Hiroki , Fukuda Katsunori , Furuta Shigeru , Hakura Akira , Sonoda Shunro
Published: August 2005

Recurrent respiratory papillomatosis (RRP) is highly prevalent in Thailand. In this study, we examined the presence of human papillomavirus (HPV) DNA in 25 RRP patients in Thailand by means of dot blot analysis and/or polymerase chain reaction. Eighty‐four percent (21/25) of cases and 4% (1/25) of cases were positive for HPV‐11 DNA and HPV‐6 DNA, respectively. Three cases (3/25) were negative for all of the examined HPV types. No cases were positive for HPV‐16 or 18. Furthermore, we isolated the recombinant HPV‐11 DNA clone from a genomic library constructed with the DNA of RRP tissue. The restriction map of the cloned HPV DNA was identical with the map of known HPV‐11 DNA. These results suggest at least that no specific HPV type or subtype is likely to be associated with RRP in Thailand.
Inhibitory Effect of Recombinant Fibronectin Polypeptides on the Adhesion of Liver‐metastatic Lymphoma Cells to Hepatic Sinusoidal Endothelial Cells and Tumor Invasion
Authors: Yoneda Junya , Saiki Ikuo , Kobayashi Hideo , Fujii Hideki , Ishizaki Yukuo , Kato Ikunoshin , Kiso Makoto , Hasegawa Akira , Azuma Ichiro
Published: August 2005

We have investigated the inhibitory mechanism of the initial arrest of L5178Y‐ML25 lymphoma cells in a target organ (liver) by using recombinant fibronectin fragments with cell‐ and/or heparin‐binding domains (C‐274, H‐271 or the fusion fragment CH‐271). Pretreatment of hepatic sinusoidal endothelial (HSE) cell monolayers with lymphoma cells or their conditioned medium for 4 to 6 h resulted in the enhancement of lymphoma cell adhesion to HSE cell monolayer. The increased tumor adhesiveness was completely abolished by preincubation of the conditioned medium with anti interleukin‐1β monoclonal antibody (mAb). Synthetic sialyl Lex (SLex) as a ligand for endothelial cell leukocyte adhesion molecule‐1 (ELAM‐1) adhesion receptor and anti ELAM‐1 mAb blocked the conditioned medium‐induced enhancement of tumor‐endothelial cell interaction, while pretreatment of the activated HSE cell monolayer with anti vascular cell adhesion molecule‐1 (VCAM‐1) mAb did not affect the enhanced tumor cell adhesion. These results indicate that tumor cell interaction with the stimulated HSE cells is mediated by ELAM‐1 molecules on HSE cells. However, the expression of SLex and SLea on the tumor surface was not observed by flow cytometric analysis. ELAM‐1‐mediated enhancement of tumor cell adhesion to HSE monolayer was also inhibited in a concentration‐dependent manner by CH‐271 fusion polypeptide or the sulfated chitin derivative sulfated carboxyntethyl‐chitin, which can bind to the heparin‐binding domain of CH‐271. In addition, CH‐271 inhibited not only tumor‐endothelium interaction hut also tumor cell invasion into reconstituted basement membrane Matrigel in vitro.
Characterization of Mouse Monoclonal Antibody B1.4 Reactive with Human Invasive Bladder Cancer and Some Other Malignant Tumors but Not with Normal Urinary Epithelium
Authors: Saiki Shigeru , Kinouchi Toshiaki , Kuroda Masao , Uenaka Akiko , Nakayama Eiichi , Kotake Toshihiko
Published: August 2005

Immunohistochemical analysis by indirect immunoperoxidase staining demonstrated that monoclonal antibody (mAb) B1.4 derived from a mouse immunized with a bladder cancer cell line EJ‐1 was reactive with a high proportion of high‐grade and invasive bladder tumors, but not with the majority of low‐grade and superficial bladder tumors, or normal urinary epithelium. Among 71 primary bladder tumors classified by pathological grading, positive stainings were observed in 1 of 34 tumors (3%) of grade 1, 8 of 20 tumors (40%) of grade 2 and 14 of 17 tumors (82%) of grade 3. When the tumors were classified by pathological staging, positive stainings were observed in only 8 of 54 (15%) superficial tumors of stages Ta and T1, but in 15 of 17 (88%) invasive tumors of stages T2 and T3. mAb B1.4 showed restricted positive stainings with normal tissues including renal glomerulus, vascular endothelium, squamous epithelium of esophagus, glandular epithelium of prostate, and epithelium of pancreatic acinar gland and minute duct, while positive stainings were observed in a range of tumor tissues other than bladder tumor. Mixed hemadsorption assays with a panel of cell cultures showed also that the antigen recognized by mAb B1.4 was expressed on a range of tumor cell lines. These findings suggest that the antigen recognized by mAb B1.4 may appear after malignant transformation, and be an indicator of malignant potential of bladder cancer.