bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrate‐ and Nitrite‐Assisted Conversion of an Acetonitrile Ligand Into an Amidato Bridge at an {Mo2(Cp)2(μ‐SMe)3} Core: Electrochemistry of the Amidato Complex [Mo2(Cp)2(μ‐SMe)3{μ‐η1,η1‐OC(Me)NH}]+
Authors: Le Hénanf Marc , Le Roy Christine , Pétillon François Y. , Schollhammer Philippe , Talarmin Jean
Published: August 2005

Treatment of [Mo2(Cp)2(μ‐SMe)3(MeCN)2]+ (1+) with NO3– or NO2– results in the conversion of one terminally bound acetonitrile ligand into an amidato bridge. The reaction produces [Mo2(Cp)2(μ‐SMe)3{μ‐η1,η1‐OC(Me)NH}]0/+ (20/+) and involves the formation of an intermediate, which was detected by cyclic voltammetry but which could not be isolated, and which likely arises from the substitution of the NOx anion for one MeCN ligand. The electrochemical behaviour of 2+ was studied by cyclic voltammetry in THF and MeCN. The reduction of 2+ in the presence of acid (HBF4/H2O or HBF4/Et2O) in these solvents leads to the release of the amidate bridge. Controlled‐potential electrolysis of 2+ in MeCN in the presence of acid produces 1+ quantitatively; the charge consumed (>1 F mol–1 of 1+) indicates that electrons are also used to reduce protons. This was confirmed by the formation of 2+ (in variable amounts depending on the conditions) on treating 2 with acid. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Self‐Assembly of 1‐D Coordination Polymers Using Organometallic Linkers and Exhibiting Argentophilic Interactions AgI···AgI
Authors: Moussa Jamal , Boubekeur Kamal , Amouri Hani
Published: August 2005

Treatment of the organometallic linkers [Cp*M(η4‐benzoquinone)] [M = Rh, LRh, (1a); M = Ir, LIr (1b)] with excess AgOTf provided the novel 1‐D coordination polymers of the formula {[Ag3(LM)2(CH3CN)2(OTf)][LM](OTf)2}n (2a,b). Single‐crystal X‐ray diffraction studies carried out on 2a and 2b showed that these polymers exhibit, as an outstanding feature, the presence of d10···d10 argentophilic interactions between the silver atoms. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
The C‐terminal Ca2+‐binding domain of SPARC confers anti‐spreading activity to human urothelial cells
Authors: Delostrinos Catherine F. , Hudson Amber E. , Feng Waldo C. , Kosman Jeffrey , Bassuk James A.
Published: August 2005

The anti‐spreading activity of secreted protein acidic and rich in cysteine (SPARC) has been assigned to the C‐terminal third domain, a region rich in α‐helices. This “extracellular calcium‐binding” (EC) domain contains two EF‐hands that each coordinates one Ca2+ ion, forming a helix‐loop‐helix structure that not only drives the conformation of the protein but is also necessary for biological activity. Recombinant (r) EC, expressed in E. coli, was fused at the C‐terminus to a His hexamer and isolated under denaturing conditions by nickel‐chelate affinity chromatography. rEC‐His was renatured by procedures that simultaneously (i) removed denaturing conditions, (ii) catalyzed disulfide bond isomerization, and (iii) initiated Ca2+‐dependent refolding. Intrinsic tryptophan fluorescence and circular dichroism spectroscopies demonstrated that rEC‐His exhibited a Ca2+‐dependent conformation that was consistent with the known crystal structure. Spreading assays confirmed that rEC‐His was biologically active through its ability to inhibit the spreading of freshly plated human urothelial cells propagated from transitional epithelium. rEC‐His and rSPARC‐His exhibited highly similar anti‐spreading activities when measured as a function of concentration or time. In contrast to the wild‐type and EC recombinant proteins, rSPARC(E268F)‐His, a point substitution mutant at the Z position of EF‐hand 2, failed to exhibit both Ca2+‐dependent changes in α‐helical secondary structure and anti‐spreading activity. The collective data provide evidence that the motif of SPARC responsible for anti‐spreading activity was dependent on the coordination of Ca2+ by a Glu residue at the Z position of EF‐hand 2 and provide insights into how adhesive forces are balanced within the extracellular matrix of urothelial cells. © 2005 Wiley‐Liss, Inc.
Prevalence and denial of sexual abuse in a male psychiatric inpatient population
Authors: Lab Damon D. , Moore Estelle
Published: August 2005

While the link between sexual abuse and psychiatric morbidity is well established, there are only a few studies that have investigated the prevalence of sexual abuse in male psychiatric populations and these studies have typically employed designs that ignore methodological issues specific to male sexual abuse. The present study aims to contribute to this research using as methodologically sound approach as possible. Seventy‐four male inpatients were interviewed using a questionnaire (J. N. Briere, 1992) about childhood sexual experiences. Approximately one third reported incidents that met this study's criteria for sexual abuse. Many of these men did not label such experiences as “sexual abuse.” The results suggest that mental health professionals need to be aware that many of their male patients may have a history of sexual abuse and that potential minimization or denial of it is a barrier to disclosure.
Psychometric properties of the PTSD Checklist with older primary care patients
Authors: Cook Joan M. , Elhai Jon D. , Areán Patricia A.
Published: August 2005

In this article the authors evaluated the posttraumatic stress disorder (PTSD) Checklist's (PCL) psychometric properties in 142 older adult primary care patients screened for several psychiatric disorders. Several established PCL scoring rules were assessed. Receiver operating characteristic analyses revealed a PCL score of 37 achieving optimal sensitivity and specificity, when compared to the PCL's algorithm‐derived PTSD diagnosis (based on whether at least one reexperiencing, three avoidance/numbing, and two hyperarousal symptoms were endorsed with a rating of 3 or higher, indicating at least moderate severity). Among depressed, anxious, and substance abusing older adults, the PCL demonstrated adequate internal consistency. It also revealed similar convergence with the Center for Epidemiological Studies‐Depression scale, found in previous research. Implications for using the PTSD Checklist with community‐dwelling older adults in primary care are discussed.
Preparation of Ready‐to‐use, Stockable and Reconstituted Collagen
Authors: Habermehl Jason , Skopinska Joanna , Boccafoschi Francesca , Sionkowska Alina , Kaczmarek Halina , Laroche Gaétan , Mantovani Diego
Published: August 2005

Summary: Collagen is a widely used material in biomedical applications. Although processes that prepare collagen and collagen‐based materials that show suitable properties after extraction exist, a ready‐to‐use, easily stockable, with tailored collagen concentration has not yet been developed. Using rat tail tendons, acid soluble collagen solutions were prepared by two different methods. To improve cell viability of pure collagen films, solutions with physiological pH were also prepared by mixing with NaOH solution. Specimens in the form of thin sheets were then fabricated by solvent evaporation. Next, IR spectroscopy, tensile testing techniques as well as human fibroblast cell morphology and cytotoxicity were used to validate the significant variations in the processes. The results demonstrated that, during the synthesis of collagen stock solution, lyophilization and mechanical blending had little effect on the final properties and therefore offers a method for obtaining solutions with a more homogeneous and modifiable collagen concentration and longer storage time. Neutralizing the stock solution with aqueous NaOH prior to solvent evaporation provided films that had lower mechanical properties but significantly improved biological performance.

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Synthesis and Characterization of Water Soluble Saccharide Functionalized Polysiloxanes and Their Use as Polymer Surfactants for the Stabilization of Polycaprolactone Nanoparticles
Authors: Racles Carmen , Hamaide Thierry
Published: August 2005

Summary: Monosaccharide functionalized polysiloxanes bearing either terminal or pendant mannose moieties have been obtained starting from the allyloxyethyl glycoside and appropriate H‐containing siloxane compounds, via hydrosilylation reactions. The starting modified monosaccharide was reacted as trimethylsilyl protected derivative and a convenient method for deprotection of the hydroxyl groups was found in order to avoid the degradation of the polysiloxane chains. The reaction products were characterized by IR and NMR spectroscopy. The water solubility of these functionalized polysiloxanes was investigated and critical micelle concentration values were found to be in the range 10−4–10−5 M. Some of the water soluble compounds were used as non ionic surfactants for the elaboration of poly(ε‐caprolactone) nanoparticles by nanoprecipitation, and particle sizes of less than 200 nm were observed.

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Lysine carboxylation in proteins: OXA‐10 β‐lactamase
Authors: Li Jie , Cross Jason B. , Vreven Thom , Meroueh Samy O. , Mobashery Shahriar , Schlegel H. Bernhard
Published: August 2005

An increasing number of proteins are being shown to have an Nζ‐carboxylated lysine in their structures, a posttranslational modification of proteins that proceeds without the intervention of a specific enzyme. The role of the carboxylated lysine in these proteins is typically structural (hydrogen bonding or metal coordination). However, carboxylated lysines in the active sites of OXA‐10 and OXA‐1 β‐lactamases and the sensor domain of BlaR signal‐transducer protein serve in proton transfer events required for the functions of these proteins. These examples demonstrate the utility of this unusual amino acid in acid‐base chemistry, in expansion of function beyond those of the 20 standard amino acids. In this study, the ONIOM quantum‐mechanical/molecular‐mechanical (QM/MM) method is used to study the carboxylation of lysine in the OXA‐10 β‐lactamase. Lys‐70 and the active site of the OXA‐10 β‐lactamase were treated with B3LYP/6‐31G(d,p) density functional calculations and the remainder of the enzyme with the AMBER molecular mechanics force field. The barriers for unassisted carboxylation of neutral lysine by carbon dioxide or bicarbonate are high. However, when the reaction with CO2 is catalyzed by a molecule of water in the active site, it is exothermic by about 13 kcal/mol, with a barrier of approximately 14 kcal/mol. The calculations show that the carboxylation and decarboxylation of Lys‐70 are likely to be accompanied by deprotonation and protonation of the carbamate, respectively. The analysis may also be relevant for other proteins with carboxylated lysines, a feature that may be more common in nature than previously appreciated. Proteins 2005. © 2005 Wiley‐Liss, Inc.
The Bloch-Vector Space for N-Level Systems: the Spherical-Coordinate Point of View
Authors: Kimura Gen , Kossakowski Andrzej
Published: August 2005

Bloch-vector spaces for N-level systems are investigated from the spherical-coordinate point of view in order to understand their geometrical aspects. We present a characterization of the space by using the spectra of (orthogonal) generators of SU (N). As an application, we find a dual property of the space which provides an overall picture of the space. We also provide three classes of quantum-state representations based on actual measurements and discuss their state-spaces.
Contextual Quantization and the Principle of Complementarity of Probabilities
Authors: Khrennikov Andrei , Kozyrev Sergei
Published: August 2005

The contextual probabilistic quantization procedure is formulated. This approach to quantization has much broader field of applications, compared with the canonical quantization. The contextual probabilistic quantization procedure is based on the notions of probability context and the principle of complementarity of probabilities. The general definition of probability context is given. The principle of complementarity of probabilities, which combines the ideas of the Bohr complementarity principle and the technique of noncommutative probability, is introduced. The principle of complementarity of probabilities is the criterion of possibility of the contextual quantization.
Expression of functionally phagocyte‐type NAD(P)H oxidase in pericytes: effect of angiotensin II and high glucose
Authors: Manea Adrian , Raicu Monica , Simionescu Maya
Published: August 2005

Background information. A growing body of evidence demonstrates the involvement of the oxidative stress in the development of vascular complications associated with diabetes, such as hypertension, retinopathy, nephropathy, neuropathy and atherosclerosis. However, the molecular mechanisms accountable for the increased production of reactive oxygen species (ROS) remain uncertain. Among others, the NAD(P)H oxidase is one of the most important sources of superoxide anion (O2−) that induce dysfunction of vascular cells. Pericytes (PCs) have an essential role in the capillary dysfunction in retinopathy and other vascular complications in diabetes. We questioned whether PCs express a functional phagocyte‐type NAD(P)H oxidase, and examined the role of angiotensin II and high glucose on the activity of the oxidase complex and expression of the essential subunit p22phox.

Results. The mRNA expression of p22phox, p47phox, p67phox and NOX 1 subunits, and the lack of gp91phox component, were detected in PCs by reverse transcriptase PCR. Western‐blotting analysis demonstrated the protein expression of p22phox, p47phox and p67phox subunits. As compared with the normal condition, stimulation of PCs with angiotensin II or high glucose induced: (i) an increase in ROS production and NAD(P)H oxidase activity, and (ii) an up‐regulation of p22phox mRNA and protein expression.

Conclusions. Taken together, the present study provides the first evidence that PCs express a functional phagocyte‐type NAD(P)H oxidase, which is up‐regulated by both angiotensin II and high glucose. Given the importance of ROS in vascular physiology and pathology, the NAD(P)H oxidase complex could be an important therapeutic target in the treatment of microvascular disorders.
Effect of sildenafil and acclimatization on cerebral oxygenation at altitude
Authors: Chan Colin W. M. , Hoar Helen , Pattinson Kyle , Bradwell Arthur R. , Wright Alexander D. , Imray Christopher H. E. ,   Expeditionary Society the Birmingham Medical Research
Published: August 2005

Phosphodiesterase-5 inhibitors decrease hypoxic pulmonary vasoconstriction under hypobaric hypoxia, but are not known to affect cerebral blood flow or oxygenation. The present study was designed to evaluate the effect of sildenafil on cerebral haemodynamics during acute exposure to altitude and after acclimatization. Ten subjects were studied 1 and 3 days after rapid ascent to 3480 m before and for two consecutive hours after taking sildenafil (50 mg). Before acclimatization, HR (heart rate) rose at 1 h (76.3±1.0 beats/min compared with 72.5±1.5 beats/min at baseline; P<0.05) and had returned to baseline at 2 h (71.3±1.1 beats/min; P>0.05). Mean BP (blood pressure) fell from 96.0±2.0 mmHg at baseline to 91.7±2.5 (P<0.001) at 1 h and 89.8±1.8 mmHg (P<0.0001) at 2 h, whereas SaO2 (arterial oxygen saturation) increased from 83.9±0.5% at baseline to 85.3±0.4% (P<0.0001) at 1 h and 85.0±0.5% (P<0.01) at 2 h. MCAV [MCA (middle cerebral artery) velocity] and PETCO2 (end-tidal partial pressure of CO2) were unchanged, but rSO2 (regional cerebral oxygen saturation) rose progressively at 1 h (62.7±0.8%; P<0.05) and 2 h (65.3±0.9%; P<0.0001) compared with baseline (59.3±1.3%). After 3 days of acclimatization, resting rSO2 and RMCA (MCA resistance) increased and oxygen delivery fell. Changes in HR and mean BP after sildenafil were similar to day 1, but SaO2 did not change. However, rSO2 increased [61.7±0.9% at baseline to 65.0±1.0% (P<0.0001) at 1 h and 64.0±0.9% (P<0.001) at 2h], despite a reduction in MCAV [65.3±1.8 cm/s at baseline to 61.3±1.5 cm/s (P<0.01) at 1 h and 60.9±1.7 cm/s (P<0.0001) at 2 h] and PETCO2 [4.1±0.05 kPa at baseline to 4.0±0.04 kPa at 2 h (P<0.01)]. These observations suggest that sildenafil improves cerebral oxygenation at altitude. Whereas the early changes before acclimatization may be largely pulmonary in origin, the later observations may be a direct cerebral effect which warrants further study.
An exponential multireference wave-function Ansatz
Authors: Hanrath Michael
Published: August 2005

An exponential multireference wave-function Ansatz is formulated. In accordance with the state universal coupled-cluster Ansatz of Jeziorski and Monkhorst [Phys. Rev. A 24, 1668 (1981)] the approach uses a reference specific cluster operator. In order to achieve state selectiveness the excitation- and reference-related amplitude indexing of the state universal Ansatz is replaced by an indexing which is based on excited determinants. There is no reference determinant playing a particular role. The approach is size consistent, coincides with traditional single-reference coupled cluster if applied to a single-reference, and converges to full configuration interaction with an increasing cluster operator excitation level. Initial applications on BeH2, CH2, Li2, and nH2 are reported.
Thermal annealing of magneto-optical (Cd,Mn)Te waveguides for optical isolators with wider operational wavelength range
Authors: Debnath M. C. , Zayets V. , Ando K.
Published: August 2005

We obtained significant improvement of magneto-optical performance by thermal annealing of the graded-index Cd1−xMnxTe waveguide. For a waveguide annealed at 425°C, complete mode conversion was achieved in a wavelength range between 710 and 735nm, which is an expansion of more than eight times that of a waveguide without annealing. The annealed waveguide also showed very low optical loss of 0.2dB∕cm and a high magneto-optical figure-of-merit of more than 1000deg∕dB∕kG. In addition, an isolation ratio of more than 20dB was obtained at λ=715–735nm in magnetic fields, H=1.6–5.1kG. This result is an important step toward achieving a practical integrated optical isolator.
Germanium n-type shallow junction activation dependences
Authors: Chui Chi On , Kulig Leonard , Moran Jean , Tsai Wilman , Saraswat Krishna C.
Published: August 2005

A few of the recent unsatisfactory germanium n-channel metal-oxide-semiconductor field-effect transistor MOSFET experimentations are believed to stem from the poor source and drain n+-p junction formations. In order to explain the primary cause and suggest rectifying solutions, we have examined the activation of common n-type dopants in germanium and the related dependences. These dependences include thermal anneal budget, impurity species, and implantation dosage. Low thermal budgets are generally preferred to activate shallow junctions to simultaneously annihilate defects and suppress fast dopant diffusion. Injecting dopants over the solid-solubility limitation into shallow junctions would only generate more implantation damage but could not however lower the junction sheet resistance.
Clinical transplantation: current problems, possible solutions
Authors: Calne Roy
Published: August 2005

I have attempted to summarize the progress that has been made in organ transplantation in the past 50 years since the first identical twin transplant. For those who have worked long in this area its success has been remarkable. We currently expect patients to survive the operation and more than 90% of the graft to be functioning at a year with the half-life of the graft beyond 10 years, with some patients surviving into the fifth decade after kidney transplantation with grafts from unrelated donors and the fourth decade for liver transplants. Now the main stumbling block is shortage of organ donors and this is unlikely to be solved easily. There has been a considerable increase in donations from living volunteers and also the worry of immoral and illegal practices.

In the future, we can expect considerable advances in immunosuppression with more effective, less toxic drugs and in some patients induction therapy that may approach tolerance so that no maintenance therapy will eventually be needed. Cell transplantation is likely to be developed as treatment for the clinic in the next 5–10 years, but developments of transplantation from animal to man still remains unsolved and unlikely to be successful in the clinic in the near future.
Incubation capacity limits maximum clutch size in black‐tailed gulls Larus crassirostris
Authors: Niizuma Yasuaki , Takagi Masaoki , Senda Mayu , Chochi Michiyo , Watanuki Yutaka
Published: August 2005

Factors determining clutch size of birds have long been the central issue in studies in life histories. It is assumed that the configuration of brood patches could limit the maximum clutch size. To test this hypothesis we manipulated clutch sizes and measured egg temperature as well as reproductive consequences in black‐tailed gulls Larus crassirostris, which usually lay two egg clutches and have three brood patches. Mean egg temperature in 4‐egg clutches (32.6±1.0°C) was significantly lower than in 2‐egg (34.6±0.4°C) and 3‐egg clutches (34.1±0.4°C), because egg temperature of the coolest egg within a 4‐egg clutch was often substantially lower than the other three eggs. The proportion of eggs hatching from 4‐egg clutches (11.6%) was lower than those of 2‐egg (49.1%) and 3‐egg clutches (52.0%). Four‐egg clutches had longer incubation periods (29.6±1.3 day) than 2‐egg (28.1±1.7 day) and 3‐egg clutches (28.0 ±1.3 day). The results indicate that incubation capacity, which may be determined by the configuration of brood patches, limits the maximum clutch size in black tailed gulls, but not the actual clutch size typically laid.
Active Efflux System for Cisplatin in Cisplatin‐resistant Human KB Cells
Authors: Fujii Ryu‐ichi , Mutoh Masato , Niwa Kiyoshi , Yamada Kazutaka , Aikou Takashi , Nakagawa Masayuki , Kuwano Michihiko , Akiyama Shin‐ichi
Published: August 2005

Mutants, KCP‐4 and PC‐5, resistant to an anticancer agent, cisplatin, were selected in multiple steps from human epidermoid KB carcinoma cells and human prostate PC‐3 carcinoma cells, respectively. KCP‐4 and PC‐5 were 63 and 10 fold more resistant to cisplatin than the parental cells, respectively. KCP‐4 cells exhibited increased resistance to cisplatin analogues and were also slightly cross‐resistant to melphalan, cyclophosphamide, mitomycin C and methotrexate. KCP‐4 cells were not cross‐resistant to doxorubicin, daunorubicin, vincristine or CdSO4. The accumulations of cisplatin in KCP‐4 cells and PC‐5 in medium containing 50 μM cisplatin were approximately 20% of those in the parental cells. Revertant analysis suggested that a defect in cisplatin accumulation may be related to cisplatin resistance in PC‐5 cells. The uncoupling agent of oxidative phosphorylation, 2,4‐dinitrophenol, increased the accumulation of cisplatin in KCP‐4 and cisplatin‐resistant human prostate carcinoma PC‐5 cells to nearly the same level as in their parental KB‐3‐1 and human prostate carcinoma PC‐3 cells without 2,4‐dinitrophenol, but did not increase accumulation in KB‐3‐1 and PC‐3 cells. Addition of glucose in the medium inhibited the enhancement of cisplatin accumulation in KCP‐4 cells by 2,4‐dinitrophenol. Enhanced active efflux of cisplatin from KCP‐4 cells was observed. A cell‐cell hybridization test showed that the cisplatin resistance and the accumulation defect behaved as codominant traits. These data suggest that an active efflux system for cisplatin exists in cisplatin‐resistant KCP‐4 cells.
Cumulative Risk of Hepatocellular Carcinoma in Hepatitis C Virus Carriers: Statistical Estimations from Cross‐sectional Data
Authors: Tanaka Hideo , Hiyama Tomohiko , Tsukuma Hideaki , Fujimoto Isaburo , Yamano Hajime , Okubo Yasuto , Kitada Akira
Published: August 2005

The probability of developing hepatocellular carcinoma (HCC) among hepatitis C virus (HCV) carriers during their life‐time is unknown. This paper addresses the estimation of the cumulative risk of HCC among HCV carriers using cross‐sectional data. Age‐specific prevalences of HCV carriers among the general population were estimated according to 5‐year age group, based on the data of 2nd‐generation anti‐HCV assay in blood donors resident in Osaka (33,226 males and 29,054 females). Seropositivity of anti‐HCV among 422 HCC cases, and the Osaka Cancer Registry data on HCC were used in the estimations of 5‐year age‐specific incidence rates of HCV‐linked HCC. Using these data, the cumulative risk, i.e., the probability of contracting HCC within the following 15 years in 50‐year‐old HCV carriers, was estimated as 28% for males and 6% for females.
Binding Characteristics of (–)‐(R)‐2‐Aminomethylpyrrolidine(1,1‐cyclobutanedi‐carboxylato)‐2‐platinum(II) to DNA, RNA and Protein Molecules in HeLa Cells and Its Lethal Effect: Comparison with cis‐ and trans‐Diammmedichloroplatinums(II)
Authors: Akaboshi Mitsuhiko , Kawai Kenichi , Ujeno Yowri , Takada Syotaro , Miyahara Tokiharu
Published: August 2005

HeLa S‐3 cells were treated with 195mPt‐radiolabeled (–)‐(R)‐2‐aminomethylpyrrolidine(1,1‐cyclobutanedicarboxylato)‐2‐platinum(II) (DWA2114R) under various conditions, and the relationship between the lethal effect of the agent and the number of platinum (Pt) atoms binding to DNA, RNA and proteins was examined. The values of mean lethal concentration for the cells treated with DWA2114 at 37°C for 1, 2 and 3 h were 137.3, 75.10 and 51.17 μM, respectively. Cells were treated identically and the numbers of Pt atoms combined with DNA, RNA and protein molecules were determined after fractionation of the cells. In this way, the D0 values (D0, dose that would give an average of one lethal event per member of the population), expressed as the drug concentration, were substituted for the number of Pt atoms combined with each fraction. The target volumes, the efficacy of Pt atom to kill cells expressed as the reciprocals of the D0 values, were then calculated for each fraction. Our findings suggested that DNA was the primary target molecule for cell killing by DWA‐2114R. The target volumes for DNA were 3.36 × 104, 4.00 × 104 and 4.10 × 104 nucleotides for 1‐, 2‐and 3‐h treated cells, respectively. The cell‐killing effects of DWA2114R were lower than those of cis‐dianuninedichloroplatinum(II) (CDDP) by factors of 1.54, 1.42 and 2.51 for 1‐, 2‐ and 3‐h treatments at 37°C, respectively, in terms of the target volume, while those in terms of the mean lethal dose (D0) were 14.8, 11.2 and 16.0, respectively. The efficacy of DWA2114R in killing the cells was 2.6 times greater than that of CDDP in the 3‐h treatment at 0°C.
Effects of Cigarette Smoke on N‐Nitrosobis(2‐oxopropyl)amine‐induced Pancreatic and Respiratory Tumorigenesis in Hamsters
Authors: Nishikawa Akiyoshi , Furukawa Fumio , Imazawa Takayoshi , Yoshimura Hiroyuki , Ikezaki Shinichiro , Hayashi Yuzo , Takahashi Michihito
Published: August 2005

Influences of cigarette smoke on N‐nitrosobis(2‐oxopropyl)amine (BOP)‐induced pancreatic duct and respiratory tract tumorigenesis were investigated using a hamster two‐stage carcinogenesis model. Male 5‐week‐old hamsters were divided into 5 groups. Group 1 was s.c. injected with BOP at a dose of 10 mgAg once a week for 3 weeks as an initiation treatment together with cigarette smoke exposure over the same 4‐week period. Group 2 was exposed to cigarette smoke for 26 weeks after the BOP‐initiation. Groups 3 and 4 were respectively given the BOP‐initiation alone and the 26‐week cigarette smoke exposure without initiation. Group 5 served as a sham‐smoked negative control. The experiment was terminated 30 weeks after the first BOP injection. The incidence of pancreatic adenocarcinomas was significantly decreased in Group 1 as compared to the Group 3 value (P < 0.01) while the Group 2 value did not show any change. In contrast, the incidence of laryngeal and tracheal proliferative lesions (hyperplasias and papillomas) was significantly increased in Group 2 over Group 3 (P<0.01). The incidence of pulmonary hyperplasias was also increased in Group 2 over Group 3 (P<0.05), although that of pulmonary adenomas or adenocarcinomas was decreased in Group 2 as compared to the Group 3 value (P<0.01). Cigarette smoke exposure in the BOP‐initiation phase (Group 1) did not affect the development of respiratory proliferative lesions. No animals in Groups 4 and 5 developed any tumors in the pancreas or respiratory tract. Our results thus indicate that cigarette smoke exposure inhibits pancreatic carcinogenesis when given in the initiation phase, whereas it modulates (enhances or suppresses) the development of proliferative lesions in the respiratory tract if applied during the promotion stage to hamsters pretreated with BOP.
Point Mutation of the E–Cadherin Gene in Invasive Lobular Carcinoma of the Breast
Authors: Kanai Yae , Oda Tatsuya , Tsuda Hitoshi , Ochiai Atsushi , Hirohashi Setsuo
Published: August 2005

Reduced or heterogeneous expression of E–cadherin has been demonstrated immunohistochemically in poorly differentiated carcinoma, which frequently shows weak intercellular adhesiveness and marked invasiveness. In vitro, not only reduced expression but also structural abnormalities of E–cadherin have been observed in human carcinoma cell lines which grow in a loosely adhering manner. To clarify the participation of structural abnormalities of E–cadherin in cancer invasion in vivo, sequence abnormalities were examined in the cadherin domain (exons 5, 6, 7 and 8) including the region essential for E–cadherin specific binding, using the polymerase chain reaction–single–strand conformation polymorphism method and direct sequencing in invasive lobular carcinoma of the breast, in which cancer cells become detached from each other and invade the stroma in a particularly scattered pattern. In 2 (10%) of the 20 cases examined, an identical sequence abnormality was detected in E–cadherin exon 7, i.e. a point mutation of codon 315 (AAT to AGT) which resulted in a single ainino acid substitution (asparagine to serine). This mutation may abolish the E–cadherin–mediated cell–cell adhesion and be at least partly responsible for the weak intercellular adhesiveness and scattered histological pattern of the tumor.
High Frequency of Cancer Patients with Abnormal Assembly of the T Cell Receptor‐CD3 Complex in Peripheral Blood T Lymphocytes
Authors: Gunji Yoshio , Hori Seiji , Aoe Tomohiko , Asano Takehide , Ochiai Takenori , Isono Kaichi , Saito Takashi
Published: August 2005

Structural abnormality of T cell receptor (TCR)‐CD3 complex on the cell surface was investigated in peripheral blood lymphocytes (PBL) from 55 cancer patients. In 24 of the 68 tests done on these patients, the CD3C chain was not detected by immunoprecipitation with anti‐CD3ζ monoclonal antibody (mAb), but was observed with anti‐CD3ζ mAb, suggesting that a high frequency of cancer patients possesses abnormal T cell receptor (TCR) complex in PBL. On the other hand, the total ζ chain was missing in several advanced cases. During follow‐up of several patients, the ζ chain became undetectable after two or three months of cancer progression. It appears that immunosuppressive status can be monitored by analyzing the TCR‐CD3 complex on the cell surface of PBL.
Activation of 2‐Hydroxyamino‐l‐methyl‐6‐phenylimidazo[4,5‐b]pyridne by cDNA‐expressed Human and Rat Arylsulfotransferases
Authors: Ozawa Shogo , Chou Hsien‐Chang , Kadlubar Fred F. , Nagata Kiyoshi , Yaraazoe Yasushi , Kato Ryuichi
Published: August 2005

Sulfation plays an obligatory role in the activation of N‐hydroxy derivatives of carcinogenic aryl‐amiric(amide)s and heterocyclic amines. We found that the hepatic sulfotransferase‐mediated covalent binding of 3H‐labeled 2‐hydroxyamino‐1‐inethy1‐6‐phenylimidazo[4,5‐b]pyridine (N‐OH‐PhIP) to calf thymus DNA was 3.3 and 12.9 times higher with human cytosol preparation than with male and female rat cytosol preparations, respectively, in the presence of 3’‐phosphnadenosine 5’‐phospho‐sulfate. To assess the activating capacities of individual phenol‐sulfating sulfotransferascs, five different forms, human ST1A2 and ST1A3 and rat ST1A1, ST1B1 and ST1C1, were expressed in heterologous cells. All five sulfotransferases mediated the activation of N‐OH‐PhIP to DNA‐bound products. The extents of the binding, however, differed considerably among these forms. Human ST1A2 and ST1A3 mediated the activation of N‐OH‐PhIP at 5.2‐ and 6.2‐fold higher rates than did rat ST1C1, a main N‐hydroxy‐2‐acetylaminofluorene‐activating sulfotransferase, in rat liver. Extents of the binding of N‐OH‐PhIP in human hepatic cytosols of different individuals were positively correlated with the contents of immunoreactive ST1A2/3. These results suggest a potential role of human liver sulfotransferases in N‐OH‐PhIP activation. In contrast, the low sulfotransferase‐mediated activation of N‐OH‐PhIP in rat liver is consistent with the lack of PhIP hepatocarcino‐genicity in this species.
Risk Factors Related to Liver Metastasis in Colorectal Carcinoma: A Multivariate Analysis of Clinicopathologic and Immunohistochemical Variables
Authors: Nagai Eishi , Yao Takashi , Sakamoto Maki , Akazawa Kouhei , Utsunomiya Takashi , Tsuneyoshi Masazumi
Published: August 2005

Specimens from 48 consecutive patients undergoing surgery for colorectal carcinoma and having synchronous or metachronous liver metastases (Group 1) and those from 52 consecutive patients who had no evidence of hepatic metastases within at least 5 year after colorectal resection (Group 2) were selected and compared using a multiple logistic regression analysis. A multivariate analysis using a stepwise logistic regression revealed six independent risk factors significantly related to hepatic metastases. In addition, the following logistic regression model was obtained from this analysis. P = exp a/(l+exp a): a = 3.524CSM‐V) + 2.731(Ex‐V) + 2.718CE/M) + 2.562(Lo) + 1.858(p53) + 1.941 (HIR)‐4.397, where P is the probability of hepatic metastasis given six independent risk factors (E/M, Ex/M ratio; Lo, location; HIR, host inflammatory cell reaction). When the estimated probability “P” in the above logistic regression model is more than 0.55 after an examination of surgical specimens, we must consider adjuvant chemotherapy and closely monitor the patient to ensure early detection of hepatic metastases.
Involvement of Sl00–related Calcium–binding Protein pEL98 (or mts1) in Cell Motility and Tumor Cell Invasion
Authors: Takenaga Keizo , Nakamura Yohko , Endo Hideya , Sakiyama Shigeru
Published: August 2005

We examined the relationship between cell motility and the expressions of pEL9S (mtsl) mRNA and protein in various imirine normal and transformed cells. The expression of pEL98 (mtsl) in v–Ha–ras–transformed NIH3T3 cells and in normal rat kidney cells transformed by either v–Ha–ras or v–src was increased over that in the corresponding parental cells at both mRNA and protein levels. The expression in normal rat fibroblasts (3Y1) transformed by v–Ha–ras was also increased compared with that in 3Y1 cells. However, the expression of pEL98 (mtsl) in 3Y1 cells transformed by v–src was increased in one clone (src 3Y1–K), but decreased in another clone (src 3Y1–H). The expression level of pEL98 (mtsl) correlated well with cell motility, which was examined by measuring cell tracks by phagokinesis. In order to test direct involvement of the pEL98 (mtsl) protein in cell motility, src 3Y1–H cells that showed low cell motility were transfected with pEL98 cDNA. The transfectants expressing large amounts of the pEL98 protein showed significantly higher cell motility than src 3Y1–H cells. The expression of pEL98 (mtsl) was also found to be correlated with motile and invasive abilities in various clones derived from Lewis lung carcinoma. These results suggest that the pEL98 (mtsl) protein plays a role in regulating cell motility and tumor cell invasiveness.
Expression of Type IV Collagen and Its Degrading Enzymes in Squamous Cell Carcinoma of Lung
Authors: Nakagawa Hideyuki , Yagihashi Soroku
Published: August 2005

We examined the in situ distribution of basement membrane collagen (Col IV), matrix metalloproteinase (MMP)‐2, MMP‐9 and tissue inhibitor of metalloproteinase‐1 (TIMP‐1) by immunohisto‐chemistry and their mRNA levels by Northern blot analysis in 14 cases of squamous cell carcinoma of the lung. Elevated mRNA levels of MMP‐2 and Col IV were demonstrated in all the cases examined and were associated with in situ disruption of basement membranes around the tumor nests. In contrast, TIMP‐1 mRNA levels were not altered. MMP‐2, MMP‐9 and TIMP‐1 were localized in tumor cells, stromal fibroblasts and endothelial cells. There were no significant correlations between these parameters and clinical staging. The results suggest that the degrading enzymes of basement membrane collagen play an important role in the invasion and metastasis of human squamous cell carcinoma of the lung.
Modulation of the Effect of l‐β‐D‐Arabinofuranosylcytosine by 6‐Mercaptopurine in L1210 Cells
Authors: Kawai Yasukazu , Ueda Takanori , Nakamura Toru
Published: August 2005

In L1210 cells incubated with l‐β‐D‐arabinofuranosylcytosine (ara‐C), 6‐mercaptopurine (6‐MP) significantly potentiated 1‐β‐D‐arabinofuranosylcytosme 5′‐triphosphate (ara‐CTP) accumulation and ara‐C incorporation into DNA (ara‐C/DNA). The cytotoxicity of these two drugs was assessed to be at least additive by clonogenic assay. l‐β‐D‐Arabinofuranosylnracil (ara‐U) level in a cell suspension was suppressed by 6‐MP in a concentration‐dependent fashion, though intracellular cytidine deaminase (CDD) activity was not affected by 6‐MP. In addition, extracted CDD activity was not directly inhibited by 6‐MP or by its intracellular metabolites in vitro. After preincubation in the presence or absence of 6‐MP, the cell suspension was fractionated to obtain the spent medium and cell pellet. Then, each fraction was incubated with ara‐C. Ara‐U formation in the spent medium was found to increase conspicuously in relation to the time of preincubation in the control and it was suppressed by 6‐MP pretreatment. Ara‐U formation in the cell compartment increased slightly in relation to the time of preincubation in the control and substantially no suppression of ara‐U formation was observed in spite of 6‐MP pretreatment. In conclusion, intracellularly synthesized CDD was thought to be rapidly shed into the medium and the released CDD could play an important role in ara‐C inactivation. 6‐MP interrupted some step between synthesis and shedding of CDD, resulting in a decrease of the ara‐C deamination in the medium and enhancement of its antileukemic effect.
Lack of Promoting Effects of α‐Linolenic, Linoleic or Palmitic Acid on Urinary Bladder Carcinogenesis in Rats
Authors: Kitano Mitsuaki , Mori Satoru , Chen Tianxin , Murai Takashi , Fukushima Shoji
Published: August 2005

Potential promoting effects of α‐linolenic, linoleic and palmitic acids were investigated in a two‐stage urinary bladder carcinogenesis model. In experiment 1, male F344 rats were given 0.05% N‐butyl‐N‐(4‐hydroxybutyl)nitrosainine (BBN) in their drinking water for 4 weeks and then basal diet containing 10%α‐linolenic, 10% linoleic or 10% palmitic acid along with 0.2% butylated hydroxyanisole (BHA) as an antioxidant for 24 weeks. The development of tumors in the urinary bladder was not increased by treatment with any of the fatty acids. In experiment 2, male F344 rats were given 10%α‐linolenic, 10% linoleic or 10% palmitic acid along with 0.2% BHA in their diet for 8 weeks without prior BBN treatment. The administration of fatty acids was not associated with any increase in the 5‐bromo‐2′‐deoxyuridine labeling index of the urinary bladder epithelium. Serum and/or urine fatty acid Ievels increased in the cases of α‐linolenic and linoleic acid treatments, but not with palmitic acid. Under the present experimental conditions neither the two polyunsaturated nor the one saturated fatty acid exerted any promoting effect on urinary bladder carcinogenesis.
Altered Expression of Hepatic CYP1A Enzymes in Rat Hepatocarcinogenesis
Authors: Degawa Masakuni , Miura Shin‐ichi , Yoshinari Kouichi , Hashimoto Yoshiyuki
Published: August 2005

Hyperplastic nodules of the liver were induced by treating male F344 rats with a combination of diethylnitrosamine and partial hepatectomy. The livers were examined for the expression of cytochrome P450 (CYP) enzymes, mainly CYP1A1 and CYP1A2; the amount and activity of the enzymes in the nricrosomes were assessed by enzymatic and immunological methods. Levels of CYP1A mRNAs were assayed by Northern blotting. In the liver bearing hyperplastic nodules, the total amount of microsomal CYP enzymes decreased to about 50% of the control. The microsomal activities for the CYP1A2‐mediated activation of carcinogenic heterocyclic amines decreased to about 20% of the corresponding controls, in association with decreases in the levels of mRNA and protein of CYP1A2. Furthermore, the inducibility of CYP1A2 by CYP1A inducers such as 3‐methoxy‐4‐aminoazobenzene and 3‐methylcholanthrene was also decreased at the mRNA, protein and activity levels. On the other hand, CYP1A1 enzyme, which was undetectable in control rat liver, appeared in the liver bearing hyperplastic nodules, but its inducibility by a CYP1A inducer decreased slightly. The present findings indicated that individual CYP1A enzymes are differently regulated, and the expression of CYP1A2 is reduced preferentially in the liver bearing hyperplastic nodules.
New Flow Cytometric Method for Detection of Minimally Expressed Multidrug Resistance P‐Glycoprotein on Normal and Acute Leukemia Cells Using Biotinylated MRK16 and Streptavidin‐RED670 Conjugate
Authors: Takeshita Akihiro , Shinjo Kaori , Ohnishl Kazunori , Ohno Ryuzo
Published: August 2005

To evaluate the expression of multidrug resistance (MDR) on normal and leukemia cells, we examined P‐glycoprotein (P‐gp) by a newly devised flow cytometric method, utilizing a biotinylated monoclonal antibody (mAb) against P‐gp (MRK16), a streptavidin‐RED670 conjugate (SA‐RED670) and appropriate emission filters. The combination of biotinylated MRK16 (b‐MRK16) and SA‐RED670 resulted in higher sensitivity as compared with standard methods such as the use of streptavidin‐phycoerythrin (SA‐PE) conjugate. The sensitivity was examined in K562, K562/ADR, NOMO‐1, NOMO‐1/ADR and HL60 cells, and compared with the data obtained from reverse transcription polymerase chain reaction (RT‐PCR) of mdr‐1 gene. P‐gp positively on flow cytometry was 10.4%, 99.9%, 1.4%, 90.4% and 0%, respectively. Mdr‐1 mRNA was well expressed in K562/ ADR and NOMO‐1/ADR cells, hut not in NOMO‐1 and HL60 cells. In K562 cells, mdr‐1 was found after 40 cycles of PCR, but not 25 cycles. These data are well correlated with those from the flow cytometry. We then studied the P‐gp expression on normal peripheral blood cells and acute leukemia cells. P‐gp was little expressed on peripheral lymphocytes, monocytes and granulocytes. It was also little expressed on blast cells from 5 patients with acute promyelocytic leukemia (APL) at diagnosis, ranging from 0.2 to 10.6% (4.6±3.9%). Ten other acute myeloid leukemia (AMD and 5 acute lymphocytic leukemia (ALL) expressed P‐gp at diagnosis, ranging from 8.5% to 34.5% (16.9± 11.8%) and from 2.3% to 45.6% (24.0±17.8%), respectively. All 9 relapsed or refractory cases expressed P‐gp, ranging from 21.1% to 99.8% (52.2±29.9%). Significant differences were found in APL, CD34‐positive and relapse and refractory cases (P=0.0006, 0.0007 and 0.0088, respectively). These results indicate that this flow cytometric analysis is useful for the evaluation of clinical MDR status and can identify a group of patients with resistant leukemia.
Tumor Cell Attachment to Lammin Promotes Degradation of the Extracellular Matrix and Cell Migration in High‐metastatic Clone Cells of RCT Sarcoma in vitro
Authors: Yudoh Kazuo , Matsui Hisao , Kanamori Masahiko , Ohmori Kazuo , Tsuji Haruo
Published: August 2005

We investigated the roles of extracellular matrix proteins, iaminin and fibronectin, in promoting invasiveness through the extracellular matrix in high‐metastatic [RCT(+)] clone cells established from poorly differentiated murine RCT sarcoma in C3H/He mice. Laminin stimulated the type IV collagenolytic activity of RCT(+) cells. After more than 6 h of incubation, the type IV collagenolysis of the cell‐conditioned medium was significantly higher in laminin‐treated groups compared with the control. The migration activity of RCT(+) cells was stimulated by laminin. However, fibronectin did not influence the type IV collagenolysis or cell migration in this clone cell. The amino acid sequence YIGSR, which is derived from laminin, inhibited the laminin‐mediated cell attachment and the laminin‐promoted type IV collagenolysis, as well as cell migration of RCT(+) cells. RGD derived from fibronectin did not influence the cell attachment to laminin or Matrigel in this clone. In the invasion assay employing a Matrigel coated filter in a Boyden chamber, YIGSR showed greater inhibition of invasion through the Matrigel than did RGD with RCT(+) cells. YIGSR might inhibit the promoted‐matrix degradation and cell migration in response to the cell attachment to laminin by competing with laminin for binding to cell surface laminin receptor. We suggest that laminin‐mediated cell attachment to the extracellular matrix may play a role in promoting the matrix degradation and cell migration during metastatic cascades.
In vivo Antitumor Activity of Hexamethylmelamine against Human Breast, Stomach and Colon Carcinoma Xenografts
Authors: Tanino Hirokazu , Kubota Tetsuro , Yamada Yoshinori , Koh Jun‐ichi , Kase Suguru , Furukawa Toshiharu , Kuo Tsong‐Hong , Saikawa Yoshiro , Kitajima Masaki , Naito Yasuaki
Published: August 2005

We have evaluated the antitumor activity of Altretamine (hexamethylmelamine, HMM) on human carcinoma xenografts serially transplanted in nude mice. Five human breast carcinoma xenografts, MX‐1, T‐61, MCF‐7, R‐27 and Br‐10, were inoculated subcutaneously into female nude mice. Two human stomach carcinoma xenografts, SC‐1‐NU and St‐4, and three human colon carcinoma xenografts, Co‐3, Co‐4 and Co‐6, were inoculated subcutaneously into male nude mice. One pellet of 17β‐estradiol (0.1 mg/mouse) was inoculated subcutaneously in the mice transplanted with MCF‐7 when the tumors were inoculated. HMM was administered per os daily for 4 weeks. MX‐1 and T‐61 tumors regressed completely after treatment with HMM at a dose of 75 mg/kg (the maximum tolerated dose: MTD) for MX‐1 and 25 mg/kg for T‐61. Br‐10 was sensitive, whereas MCF‐7 and R‐27 were resistant to HMM at its MTD. HMM exerted the most potent antitumor effect against T‐61. Against MX‐1, it exerted an antitumor effect equivalent to that of cisplatin or cyclophosphamide. In addition, this agent was effective against all stomach and colon carcinoma xenografts, in particular St‐4 (T/C%= 10.7: the mean tumor weight of treated group/the mean tumor weight of control group) and Co‐3 (T/C%=31.5%) which are insensitive to presently available agents. HMM seems worthy of further clinical investigation as a candidate agent to treat breast, stomach, colon and other carcinomas.