bluuebunny/crossref_metadata_2025 huggingface dataset:
Skin roughness is negatively correlated to irritation with DMSO, but not with NaOH and SLS
Authors: Iliev D. , Hinnen U. , Elsner P.
Published: April 2006

Abstract While many endogenous and exogenous factors have been found to influence skin irritant reactivity, the role of skin roughness in irritation has not yet been studied. In this study we measured skin roughness by visiometry and performed irritation tests on the flexural side of the forearm with sodium hydroxide (NaOH), sodium lauryl sulphate (SLS) and dimethyl sulfoxide (DMSO) in two different concentrations in a population of 151 volunteers between 15 and 25 years of age. The results showed a significant negative correlation between most roughness parameters and DMSO irritation. The correlation between roughness parameters and irritation tests with SLS and NaOH was not significant. We conclude that smoother skin is more prone to DMSO irritation than rougher skin and that this may be due to differences in percutaneous penetration of the compound.
Superantigens but not mitogens are capable of inducing upregulation of E‐selectin ligands on human T lymphocytes
Authors: Zollner T. M. , Nuber V. , Duijvestijn A.‐M. , Boehncke W.‐H. , Kaufmann R.
Published: April 2006

Abstract Bacterial infections can exacerbate immune mediated dermatoses, possibly via Superantigens produced by these bacteria. Therefore, we asked whether Superantigens induce the expression of adhesion molecules which may then facilitate invasion of highly activated T cells into different organs. The influence of exfoliative toxin (ET) and toxic shock syndrome toxin‐1 (TSST‐1) stimulation on the expression of a broad panel of adhesion and coslimulatory molecules was investigated by flow cytometry. We found that only the E‐selectin ligands cutaneous lymphocyte‐associated antigen (CLA) and sialylated Lewisx (CD15s) are significantly upregulated by these Superantigens but not by mitogen stimulation. In contrast, the mucosal lymphocyte‐associated antigen (MLA) recognized by the monoclonal antibody Ber‐Act8 was.not differentially induced by mitogen or superantigen stimulation. Therefore, T lymphocyte stimulation by bacterial Superantigens might directly influence their skin homing capacity. Furthermore, the superantigen‐driven induction of CD15s ‐ an adhesion molecule which is absent or only weakly expressed by resting or mitogen stimulated T cells may indicate a role of this antigen for T cell skin homing. An additional adhesion pathway via E‐selectin may thus be available to lymphocytes, comparable to granulocyles which constitutively express CD15s.
Antiflammin 1 peptide delivered non‐invasively by iontophoresis reduces irritantinduced inflammation in vivo
Authors: Mize Nancy K. , Buttery Margaret , Ruis Nancy , Leung Iris , Cormier Michel , Daddona Peter
Published: April 2006

Abstract The potential of an anti‐inflammatory peptide (antiflammin 1) to reduce irritation when delivered transdermally by iontophoresis was examined. A model drug irritant, chlorpromazine, was co‐delivered with and without antifiammin 1 by iontophoresis to hairless guinea pigs transdermally. Quantitative skin irritation measurements were obtained by monitoring erythema by skin color reflectance with the Minolta Chromameter. Antifiammin 1 delivered by iontophoresis significantly decreased, but did not eliminate, the erythema associated with co‐delivery of an irritating drug compound. Lesion formation was also reduced in the presence of antiflammin 1. In vitro flux across hairless guinea pig skin demonstrated no significant differences in flux of the irritant compound in the presence or absence of antiflammin 1. In vivo generation and efflux of the inflammation mediator Prostaglandin E2 increased during 24‐h application of irritant and was unchanged in the presence of antiflammin 1. This result is discussed with respect to recent evidence that antiflammins may act on the lipo‐oxygenase pathway. In summary, antiflammin 1, an antiflammatory peptide, can be delivered transdermally by iontophoresis with retention of its biological activity in vivo.
Differential modulation of IL‐8 and TNF‐α expression in human keratinocytes by buflomedil chlorhydrate and pentoxifylline
Authors: Redondo Pedro , García‐Foncillas Jesús , España Agustín , Cuevillas Fernando , Quintanilla Eniilio
Published: April 2006

Abstract Pentoxifylline (PTX) is a methylxanthine derivative used in a wide range of dermatoses. As well as its hemorrheologic activity, PTX has anti‐inflammatory properties. Buflomedil chlorhydrate (BC) is another hemorrheological drug with peripheral vasodilatory action, whose clinical uses are similar to those of PTX. Both drugs increase intracellular levels of cAMP, either secondary to phosphodiesterase inhibition (PTX) or adenyl‐cyclase stimulation (BC). Long‐term cultures of normal human keratinocytes were prepared in a free‐serum medium, and stimulated with 1 mg/ml of phorbol 12‐myristate 13‐acetate (TPA) and PTX or BC (100–1000 üg/ml). Levels of TNF‐α. IL‐lα, IL‐lβ, IL‐8 and TGF‐β1 using ELISA and Northern blot or RT‐PCR techniques were measured. TPA‐induced TNF‐a and IL‐8 release from keratinocytes. TPA did not induce IL‐la or IL‐lβ release of keratinocytes. TPA increased RNA expression of the TNF‐α, IL‐lα, IL‐lβ, IL‐8 and TGF‐(31. BC diminished TPA‐induced TNF‐α and IL‐8 release from keratinocytes; in the case of IL‐8 it is possible that this inhibition occur to transcriptional level. Moreover PTX was unable to inhibit TNF‐α and IL‐8 synthesis and expression. PTX and BC reduced TPA‐induced IL‐lα and P expression. It is possible that BC action is specifically exerted on keratinocytes, because we did not find similar results with TNF‐α and IL‐8 synthesis in mononuclear peripheral blood cells.
Immunohistochemical expression of IL‐10 in mycosis fungoides
Authors: Buhl Line , Sogaard Helmer
Published: April 2006

Abstract Immunoreactivity of the cytokine IL‐10 has been investigated in situ in mycosis fungoides (MF). Expression of IL‐10 was detected using immunohistochemistry in skin biopsies (n=8) and T‐cell lines (n= 2) from mycosis fungoides patients. IL‐10 positivily was seen in the dermal cell infiltrates and in T‐cell lines in mycosis fungoides. The dermal IL‐10 reaction in a skin biopsy from an active lesion in MF indicates the possibility for disease progression.
Parents’ Workplace Situation and Fathers’ Parental Leave Use
Authors: Bygren Magnus , Duvander Ann‐Zofie
Published: April 2006

This study examines how the workplace situation of both parents affects fathers’ parental leave use. We used parental leave‐taking register data from Statistics Sweden for dual‐earner couples who resided in Stockholm and had children in 1997 (n= 3,755). The results indicate that fathers shorten their parental leave if their workplaces are such that one can expect leave to be associated with high costs and that fathers appear to be influenced by the leave use of other fathers in the workplace. Mothers’ workplace situation appears to be less important for fathers’ leave use. The results point to the importance of actors other than parents (such as employers) for understanding the gender‐based division of child care.
The School Nurse’s Role in Prevention of Student Use of Performance‐Enhancing Supplements
Authors: Garzon Laurel S. , Ewald Rebecca E. , Rutledge Carolyn M. , Meadows Teresa
Published: April 2006

Abstract: An alarming trend in the United States is the use of performance‐enhancing supplements by children and adolescents. These widely available over‐the‐counter products, often marketed as natural substances, are not regulated by the Food and Drug Administration and are thus widely available. High school and even middle school students are using these supplements because they are misled into thinking that supplements will enhance their athletic skills resulting in an improvement in their performance. Yet, the safety and long‐term effects of these supplements have not been established in reputable or prevalent studies. School nurses have a unique opportunity and even an ethical responsibility to help in efforts to address this growing trend. Specific roles for the school nurse include serving as a student advocate for the health and safety of children and adolescents; identifying at‐risk students; forming partnerships with teachers, parents, students, coaches, athletic trainers, and local health care providers; evaluating and refining health‐oriented curricula; collecting and disseminating new knowledge; and staying abreast of new findings. (J Sch Health. 2006;76(5):159‐163)
Results From the 2004 Michigan Farm‐to‐School Survey
Authors: Izumi Betty T. , Rostant Ola S. , Moss Marla J. , Hamm Michael W.
Published: April 2006

Abstract: The purpose of this study was to investigate Michigan school food service directors’ interest in, and opportunities and barriers to, implementing a farm‐to‐school program. Farm‐to‐school may be a timely and innovative approach to improving the school food environment and helping food service directors meet their nutrition goals for school meals. Health and agriculture advocates have recognized the importance of farm‐to‐school in addressing health issues and creating opportunities for farmers and rural communities. Research subjects were 664 food service directors representing school districts across Michigan. Respondents (n = 383) reported a high degree of interest in sourcing food from local producers (73% reported being very interested or interested). Interest was significantly augmented (83%) when respondents were asked to assume that these foods were available through current vendors. Interest was independent of free/reduced lunch participation rate or school district location (rural, suburban, urban location). Food service directors expressed diverse motivations for their interest in farm‐to‐school, including supporting the local economy and community; accessing fresher, higher‐quality food; and potentially increasing students’ fruit and vegetable consumption. The most frequently reported barriers and concerns included cost, federal and state procurement regulations, reliable supply, seasonality of fruits and vegetables, and food safety. Michigan school food service directors appear ready to make linkages with local agriculture. However, there is need to address the concerns and barriers through education; inclusion of community partners, such as current vendors; funding; and state and federal policies that support local purchasing. (J Sch Health. 2006;76(5):169‐174)
Predictors of Suicidal Ideation Among High School Students by Gender in South Korea
Authors: Park Hyun Sook , Schepp Karen G. , Jang Eun Hee , Koo Hyun Young
Published: April 2006

Abstract: The purpose of this study was to examine the evidence to determine if there are gender differences in suicidal ideation of adolescents. This study examined the main effect of risk factors from 5 domains and protective factors from 1 domain in relation to suicidal ideation by gender and identified the most important predictors of suicidal ideation for males (N = 654) and females (N = 658). This study was a cross‐sectional survey, and data were collected through self‐report questionnaires. In the univariate analysis, especially, risk factors from behavioral variables and psychosocial‐environmental variables appeared to be gender skewed. For males, all behavioral variables were predictive of suicidal ideation. For the females, unlike the males, Wang‐tta or victim of bullying behavior and sexual orientation as behavioral variables were predictive of suicidal ideation. For males, parental divorce and parental alcohol abuse as psychosocial‐environmental variables were predictive of suicidal ideation. For the females, again unlike for the males, all the psychosocial‐environmental variables were not predictive of suicidal ideation. The most important predictors of suicidal ideation for males as a result of the multivariate analysis were history of suicidal attempt, depression, hostility, smoking, parental alcohol abuse, communication with friends, and self‐esteem. The most important predictors of suicidal ideation for females as a result of the multivariate analysis were depression, hostility, sexual orientation, and self‐esteem. These results would indicate that an effective suicide screening and prevention program for adolescents should consider gender differences. (J Sch Health. 2006;76(5):181‐188)
Racial Disparities in Tobacco Use and Social Influences in a Rural Southern Middle School
Authors: Muilenburg Jessica L. , Johnson William D. , Annang Lucy , Strasser Sheryl M.
Published: April 2006

Abstract: This study investigated racial differences of tobacco use and social exposure to tobacco products in a sample of middle school students. Questionnaires were administered in January 2005 to 290 students in a Mississippi Delta‐area middle school. The participants were 51.0% female and 56.6% African American. Unadjusted odds ratios revealed that Caucasian students were statistically more likely than were African American students to (1) have ever tried smoking, (2) have ever been a daily smoker, (3) have smoked in the past 30 days, (4) live with someone who smokes, (5) have seen a parent or guardian smoke, and (6) have friends who smoke. In contrast, African Americans were more likely to report “no one is allowed to smoke” in their home. Caucasian females had the highest rates of smoking, as well as the highest exposure to social smoking behaviors. This study not only showed that Caucasians were indeed smoking more but also that African American adolescents do not have the same exposure to social smoking, particularly African American females. Of particular interest was why the differences eventually dissipate and smoking rates are virtually the same in adulthood. A greater understanding of the impact of exposure to tobacco use on an adolescent’s own tobacco use is vital to prevention efforts, especially in regard to racial differences. Future research on youth tobacco prevention and cessation programs should focus on sociocultural and racial differences in the development of tobacco use in adolescents. (J Sch Health. 2006;76(5):195‐200)
Contribution of polyunsaturated fatty acids to Shiga toxin cytotoxicity in human renal tubular epithelium-derived cells
Authors: Sasaki Taku-Kemal , Takita Toshichika
Published: April 2006

Shiga toxin (Stx) produced by enterohemorrhagic Escherichia coli is a critical factor in the onset of hemolytic uremic syndrome. The current study was designed to assess whether n-3 and (or) n-6 polyunsaturated fatty acids (PUFA) act as a valuable adjunct to prevent the cell injury of renal tubule cells in the emergence of HUS. The target cells, ACHN cells derived from human tubule epithelium, were cultured with each PUFA, then exposed to Stx-1 or Stx-2. The rank order of potency of PUFA to inhibit the cell death caused by each toxin was as follows: EPA > AA = DHA >> LNA. There were dose-response relations in the efficacy of each PUFA. No prophylactic effect was found in the cultures with LA. Immunofluorescence assays revealed that both the expression of the toxin receptor on ACHN cells and binding between the toxin and cells were unaffected by the PUFA. These results suggest that EPA is the most efficacious PUFA against the renal tubule cell injury caused by Stx, which may be assigned to an alteration in the intracellular pathway leading to cell death.Key words: Shiga toxin, verotoxin, enterohemorrhagic Escherichia coli, polyunsaturated fatty acid.
Control of mitochondrial gene expression in the aging rat myocardium
Authors: LeMoine Christophe M.R , McClelland Grant B , Lyons Carrie N , Mathieu-Costello Odile , Moyes Christopher D
Published: April 2006

Aging induces complex changes in myocardium bioenergetic and contractile properties. Using F344BNF1rats, we examined age-dependent changes in myocardial bioenergetic enzymes (catalytic activities and transcript levels) and mRNA levels of putative transcriptional regulators of bioenergetic genes. Very old rats (35 months) showed a 22% increase in ventricular mass with no changes in DNA or RNA per gram. Age-dependent cardiac hypertrophy was accompanied by complex changes in mitochondrial enzymes. Enzymes of the Krebs cycle and electron transport system remained within 15% of the values measured in adult heart, significant decreases occurring in citrate synthase (10%) and aconitase (15%). Transcripts for these enzymes were largely unaffected by aging, although mRNA levels of putative transcriptional regulators of the enzymes (nuclear respiratory factor (NRF) 1 and 2 α subunit) increased by about 30%–50%. In contrast, enzymes of fatty acid oxidation exhibited a more diverse pattern, with a 50% decrease in β-hydroxyacyl-CoA dehydrogenase (HOAD) and no change in long-chain acyl-CoA dehydrogenase or carnitine palmitoyltransferase. Transcript levels for fatty acid oxidizing enzymes covaried with HOAD, which declined significantly by 30%. There were no significant changes in the relative transcript levels of regulators of genes for fatty acid oxidizing enzymes: peroxisome proliferator-activated receptor-α (PPARα), PPARβ, or PPARγ coactivator-1α (PGC-1α). There were no changes in the mRNA levels of Sirt1, a histone-modifying enzyme that interacts with PGC-1α. Collectively, these data suggest that aging causes complex changes in the enzymes of myocardial energy metabolism, triggered in part by NRF-independent pathways as well as post-transcriptional regulation.Key words: PGC-1a, fatty acid oxidation, nuclear respiratory factor (NRF), PPAR, coactivator, transcriptional regulation.
Expression of MG7-Ag in patients with gastric cancer correlates with weaker T cell immune response and more proinflammatory cytokine secretion
Authors: Zhang Xiaoyin , Hong Liu , Chan W Y , Qiao Taidong , Chen Baojun , Liu Y , Fan Daiming
Published: April 2006

MG7-Ag is a human gastric-carcinoma-associated antigen with a high specificity. So far it is remained unclear whether MG7-Ag is correlated with the in vivo cellular immune response of patients with gastric cancer. In this study, we detected the expression of the T cell receptor (TCR) repertoire of T cell subpopulations and cytokines in tumor-infiltrating lymphocytes (TIL), peripheral blood lymphocytes (PBL), and residue benign mucosal lymphocytes (NML) of patients with gastric cancer using semiquantitative RT-PCR. Our data showed that the expanded clones in CD8+NML and TIL and CD4+NML and PBL in MG7-Ag-positive patients were significantly fewer than those of MG7-Ag-negative patients (p = 0.0360; p = 0.0026; p = 0.0065 p = 0.0109, respectively). The levels of IL-8 in CD8+TIL and TNF in CD4+TIL from the MG7-Ag-positive group were significantly higher than those from the MG7-Ag-negative group (p = 0.0302; p = 0.0177, respectively). Taken together, the results demonstrated a weaker T cell immune response and more proinflammatory cytokine secretion in MG7-Ag-positive patients with gastric cancer than in MG7-Ag-negative ones. This likely contributes to the poor prognosis in MG7-Ag-positive gastric-cancer patients.Key words: gastric carcinoma, tumor-associated antigen, T cell receptor repertoire, cytokine, RT-PCR.
Harnessing asymmetrical substrate recognition by thermostable EndoV to achieve balanced linear amplification in multiplexed SNP typing
Authors: Turner Daniel J , Pingle Maneesh R , Barany Francis
Published: April 2006

Multiplexed amplification of specific DNA sequences, by PCR or by strand-displacement amplification, is an intrinsically biased process. The relative abundance of amplified DNA can be altered significantly from the original representation and, in extreme cases, allele dropout can occur. In this paper, we present a method of linear amplification of DNA that relies on the cooperative, sequence-dependent functioning of the DNA mismatch-repair enzyme endonuclease V (EndoV) from Thermotoga maritima (Tma) and Bacillus stearothermophilus (Bst) DNA polymerase. Tma EndoV can nick one strand of unmodified duplex DNA, allowing extension by Bst polymerase. By controlling the bases surrounding a mismatch and the mismatch itself, the efficiency of nicking by EndoV and extension by Bst polymerase can be controlled. The method currently allows 100-fold multiplexed amplification of target molecules to be performed isothermally, with an average change of <1.3-fold in their original representation. Because only a single primer is necessary, primer artefacts and nonspecific amplification products are minimized.Key words: EndoV, endonuclease V, nicking, extension, mismatch, DNA amplification, Bst polymerase.
NONLINEAR OPTICS WITH HARD X-RAYS: HARMONIC GENERATION AND RAMAN SCATTERING IN PERFECT CRYSTALS
Authors: NAZARKIN A. , USCHMANN I. , FÖRSTER E. , SAUERBREY R.
Published: April 2006

Based on dynamical diffraction theory, we study nonlinear processes in the hard X-ray region. First, we consider the process of frequency doubling in perfect crystals in the general case where the process of Bragg rescattering of the generated harmonic field should be taken into account. The optimum conversion conditions for the Bragg and Laue interaction geometry are determined and the efficiency is calculated. Secondly, we consider the modulation of X-ray diffraction by a wave of coherent optical phonons produced by an intense laser pulse. We show that in the optimum regime the modulation period of the X-ray beam may be even shorter than the period of the excited optical phonons, as a result of higher order Raman scattering. Generation of extremely short X-ray pulses using this technique is discussed. Our results suggest that synchronous interaction schemes analogous to the schemes long known in nonlinear optics can significantly increase the efficiency of nonlinear processes in the hard X-ray region.
CHAOTIC SECURE COMMUNICATION BASED ON THE CONCEPT OF EQUIVALENT CONTROL
Authors: CHEN MAO-YIN , ZHOU DONG-HUA , SHANG YUN
Published: April 2006

This Letter considers the problem of chaotic secure communication in the drive-response framework. The drive system can be augmented into a higher order system, and then a sliding mode observer based response system can be constructed to synchronize this augmented system. If they satisfy certain conditions, the hidden message can be recovered directly by the concept of equivalent control. Theoretical analysis and numerical simulation verify the effectiveness of the proposed method.
CONDITIONALLY INVARIANT MEASURES FOR POSITION DEPENDENT RANDOM MAPS OF AN INTERVAL WITH HOLES
Authors: BAHSOUN WAEL , GÓRA PAWEŁ
Published: April 2006

We study position dependent random maps on the unit interval with holes where the possible laws of motion are piecewise monotonic transformations. The main result of this note is proving the existence of absolutely continuous conditionally invariant measures.
Citrulline modulates muscle protein metabolism in old malnourished rats
Authors: Osowska S. , Duchemann T. , Walrand S. , Paillard A. , Boirie Y. , Cynober L. , Moinard C.
Published: April 2006

Protein energy malnutrition is common in the elderly, especially in hospitalized patients. The development of strategies designed to correct such malnutrition is essential. Our working hypothesis was that poor response to nutrition with advancing age might be related to splanchnic sequestration of amino acids, which implies that fewer amino acids reach the systemic circulation. Administration of citrulline, which is not taken up by the liver, can offer a means of increasing whole body nitrogen availability and, hence, improve nutritional status. Thirty old (19 mo) rats were submitted to dietary restriction (50% of food intake) for 12 wk. They were randomized into three groups: 10 rats (R group) were killed and 20 others refed (90% of food intake) for 1 wk with a standard diet (NEAA group) or a citrulline-supplemented diet (Cit group). Before being killed, the rats were injected with [13C]valine, and the absolute protein synthesis rate (ASR) was measured in the tibialis using the flooding-dose method. When the rats were killed, the tibialis was removed for protein content analysis. Blood was sampled for amino acid and insulin analysis. The standard diet did not have any effect on protein synthesis or on the protein content in the muscle. Citrulline supplementation led to higher protein synthesis and protein content in muscle (117 ± 9, 120 ± 14, and 163 ± 4 mg/organ for protein content in R, NEAA, and Cit groups, P < 0.05). The ASR were 0.30 ± 0.04, 0.31 ± 0.04, and 0.56 ± 0.10 mg/h in the three groups, respectively (R and NEAA vs. Cit, P < 0.05). Insulinemia was significantly higher in the Cit group. For the first time, a realistic therapeutic approach is proposed to improve muscle protein content in muscle in frail state related to malnutrition in aging.
Phase II Clinical Trial Design: Methods in Translational Research from the Genitourinary Committee at the Eastern Cooperative Oncology Group
Authors: Gray Robert , Manola Judith , Saxman Scott , Wright John , Dutcher Jan , Atkins Michael , Carducci Michael , See William , Sweeney Christopher , Liu Glenn , Stein Mark , Dreicer Robert , Wilding George , DiPaola Robert S.
Published: April 2006

Given the increase in novel agents and difficulty with planning and completing many phase III studies, various phase II trial design options should be considered to more effectively guide phase III trial plans. The need for novel phase II trial designs has increased, given the number of novel molecular targeted therapies now available for testing, an abundance of cytostatic agents, and limited resources to conduct phase III studies for all interesting agents or combinations. This review will focus on options for phase II trial designs. We review randomized phase II designs with placebo control, randomized selection designs, and randomized discontinuation designs. As agents become available for testing in the clinic, the strengths and weaknesses of different phase II trial designs should be considered to optimize a trial development plan that guides phase III trial decisions more effectively.
Targeting Gastrin-Releasing Peptide Receptors on Small Cell Lung Cancer Cells with a Bispecific Molecule that Activates Polyclonal T Lymphocytes
Authors: Zhou Jiehua , Chen Jian , Zhong Ruikun , Mokotoff Michael , Shultz Leonard D. , Ball Edward D.
Published: April 2006

Purpose: Gastrin-releasing peptide (GRP) is a growth factor for small cell lung cancer (SCLC). GRP belongs to the bombesin peptide family and has significant homology to bombesin. We constructed a bispecific molecule, OKT3xAntag2, by conjugating a monoclonal antibody OKT3 (anti-CD3) with a bombesin/GRP antagonist (Antag2) and evaluated cytotoxicity against SCLC cells.

Experimental Design: We tested binding of the bispecific molecule to SCLC cell lines and T cells by flow cytometry, antibody-dependent cellular cytotoxicity (ADCC) of SCLC cells in vitro and in a murine SCLC xenograft model. We studied SCLC apoptosis and necrosis during ADCC and the activity and cleavage of caspase-3, caspase-9, and poly(ADP-ribose) polymerase (PARP).

Results: The bispecific molecule functions as a cross-linker between T cells and SCLC cells, induces T cell activation, and mediates ADCC of SCLC cells; 40% to 80% growth inhibition of SCLC cells mediated by the bispecific molecule at low effector to target cell ratios was achieved. Activation of T cells by the bispecific molecule resulted in significant increases in IFNγ production and apoptosis and necrosis of SCLC cells associated with cleavage of PARP and caspase-3. Targeted immunotherapy with the bispecific molecule–armed human T cells significantly reduced SCLC tumor burdens in a mouse model.

Conclusion: The bispecific molecule OKT3xAntag2 mediates growth inhibition and apoptosis of SCLC cells by activated T cells through activation and cleavage of caspase-3 and PARP in vitro and in vivo. Clinical trials of this bispecific molecule through adoptive transfer of ex vivo activated T cells in GRP receptor–positive tumors, such as SCLC, are warranted.
Thymidylate Synthase Messenger RNA Expression in Plasma from Patients with Colon Cancer: Prognostic Potential
Authors: Garcia Vanesa , García José M. , Peña Cristina , Silva Javier , Domínguez Gemma , Hurtado Alicia , Alonso Isabel , Rodriguez Rufo , Provencio Mariano , Bonilla Félix
Published: April 2006

Purpose: Thymidylate synthase (TS), a critical target in fluorouracil-based chemotherapy, is a prognostic marker in colon carcinomas and a predictor of response to treatment. Tumor RNA has been detected in plasma from cancer patients and is associated with poor prognosis. This is the first study to examine extracellular TS mRNA in plasma from patients with colon carcinoma, and its possible relation with TS promoter enhancer region (TSER) polymorphism.

Experimental Design: TS expression was measured in plasma from 88 patients and 26 controls, and in a tumor subgroup of this series by quantitative PCR. Genotyping for TSER polymorphism was done in 60 patients. Clinicopathologic variables were correlated with these molecular changes.

Results: TS mRNA was detected in plasma in 47% of patients, showing significant differences from healthy controls. Patients with TS mRNA in plasma had higher levels of TS in tumor tissue than patients without. The presence of TS mRNA was associated with lymph node metastases and more advanced stages. Polymorphism TSER 3/3 was found in 38% of cases, and was significantly correlated with high amounts of TS mRNA in plasma.

Conclusions: Our results suggest that TS mRNA in plasma originated from tumors, it may indicate poor prognosis and might help to classify tumors in Dukes' stages B and C. The TSER genotype may influence TS mRNA expression in plasma.
Synergistic Antitumor Effects of Combined Epidermal Growth Factor Receptor and Vascular Endothelial Growth Factor Receptor-2 Targeted Therapy
Authors: Tonra James R. , Deevi Dhanvanthri S. , Corcoran Erik , Li Huiling , Wang Su , Carrick Francine E. , Hicklin Daniel J.
Published: April 2006

Purpose: Combination therapies that target the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) pathways, are being actively tested for the treatment of cancer. In evaluating combination strategies, the ideal combination would be one in which the treatments interact in a way that is synergistic with regard to antitumor effects. Here, we have evaluated the interaction between anti-EGFR antibody Erbitux (cetuximab) and anti-VEGFR2 antibody, DC101, in preclinical models of pancreatic (BxPC-3) and colon (GEO) cancer.

Experimental Design: Analysis of the interaction between cetuximab and DC101 in vivo used a novel method for establishing the upper 95% confidence limits for the combination index (CI) of isobologram analyses, where CI < 1 indicates synergy. Assessment of tumor cell proliferation, apoptosis, VEGF production, and hypoxia, as well as tumor vascularization, was performed to gain insights into the mechanistic basis for synergy between agents targeting different tumor compartments.

Results: Monotherapy ED50 values for tumor growth inhibition ranged from 1.8 to 2.3 mg/kg and 10.5 to 16.6 mg/kg for cetuximab and DC101, respectively. From the dose response of the combination treatment, it was determined that cetuximab and DC101 are synergistic in the BxPC-3 (CI = 0.1, P < 0.01) and GEO (CI = 0.1, P < 0.01) models. Overlapping effects on the tumor cell and vascular compartments form a basis for the interaction, with VEGF production and hypoxia-inducible factor 1α potentially acting as molecular links between EGFR and VEGFR2 inhibition.

Conclusions: Results show antitumor synergy for combined EGFR and VEGFR2 targeted therapy, supporting the significant therapeutic potential of this combination strategy.
Pediatric Cancers Are Infiltrated Predominantly by Macrophages and Contain a Paucity of Dendritic Cells: a Major Nosologic Difference with Adult Tumors
Authors: Vakkila Jukka , Jaffe Ronald , Michelow Marilyn , Lotze Michael T.
Published: April 2006

Purpose: Adult cancer is frequently preceded by a period of prolonged chronic inflammation caused by infectious microbial agents or physical or chemical irritants. By contrast, an association between the classic pediatric neoplasias and inflammatory triggers is only rarely recognized. We hypothesized that the difference could be reflected in the inflammatory cell infiltrates of pediatric and adult cancer.

Experimental Design: Three investigators retrospectively studied 27 pediatric and 13 adult cancers at first diagnosis by immunohistochemistry. Inflammatory cells were identified and counted, and their location in relation to tumor tissue was analyzed.

Results: A majority of tumor-associated leukocytes (TAL) in adult tumors were located at the edges of tumor islands forming inflammatory foci between the supporting stroma and the malignant infiltrate. In contrast, TALs in pediatric tumors were scattered within the malignant tumor islands. In adult tumors, TALs were composed of diverse leukocyte types; but in pediatric tumors, the infiltrating cells were predominantly macrophages that accumulated in areas of necrosis within the tumors. The most striking feature in the pediatric tumors was the virtual absence of dendritic cells. The proportion of intratumoral dendritic cells in pediatric samples was 4.1%; whereas in adult tumors, they formed 36.9% of TALs within the tumor islands and 25.1% around the tumors.

Conclusions: We conclude that TALs in pediatric cancers are composed mainly of macrophages and largely devoid of dendritic cell. The findings may provide a major nosologic difference reclassifying pediatric and adult tumors based on nominal inflammatory and noninflammatory etiologies.
Messenger RNA Expression of Leptin and Leptin Receptors and their Prognostic Value in 322 Human Primary Breast Cancers
Authors: Révillion Françoise , Charlier Madia , Lhotellier Valérie , Hornez Louis , Giard Sylvia , Baranzelli Marie-Christine , Djiane Jean , Peyrat Jean-Philippe
Published: April 2006

Purpose: Leptin and obesity are clearly related, and obesity is associated with an increased risk of breast cancer. We therefore measured the expression of leptin and its two main receptor isoforms, OBR-L and OBR-S, in 322 breast cancers. We analyzed their relations with the classical prognostic factors and with survival to establish their links with breast cancer.

Experimental Design: The expression of leptin and its receptors was quantified by real-time reverse transcription-PCR, using TaqMan fluorogenic probes and an ABI PRISM 7700 sequence detector system (Applied Biosystems, Courtaboeuf, France). TATA box binding protein was used to normalize expression. The human breast cancer cell, SK-BR-3, expressing the three targets, was chosen as the calibrator sample (i.e., target expression = 1).

Results: All the tumors expressed both receptors, and 318 of 322 expressed leptin. These three variables correlated positively with each other and with estradiol and progesterone receptors, whereas they correlated negatively with histoprognostic grading and tumor diameter. OBR-L/OBR-S expression was inversely correlated with progesterone receptors. Patients with elevated OBR-S expression had longer relapse-free survival (P = 0.008), whereas high OBR-L/OBR-S was associated with a shorter relapse-free survival (P = 0.05). In Cox multivariate analyses, OBR-S maintained its prognostic value (P = 0.02; relative risk, 0.51).

Conclusions: This study shows that (a) almost all of the breast cancers coexpress leptin and its two main isoforms of receptors, suggesting that the human epithelial breast cancer cells respond to leptin acting via an autocrine pathway; (b) high expression levels of leptin and leptin receptors are biological markers of a more differentiated phenotype; and that (c) OBR-S is an independent prognostic factor.
Carbon Beam Therapy Overcomes the Radiation Resistance of Uterine Cervical Cancer Originating from Hypoxia
Authors: Nakano Takashi , Suzuki Yoshiyuki , Ohno Tatsuya , Kato Shingo , Suzuki Michiya , Morita Shinroku , Sato Shinichiro , Oka Kuniyuki , Tsujii Hirohiko
Published: April 2006

Purpose: High linear energy transfer (LET) particles are believed to decrease tumor radiation resistance originating from hypoxia. However, no proof of this effect has been provided by clinical trials and related clinical research. Hence, we investigated the radiation biological aspects of high LET carbon beam therapy on cervical cancer.

Experimental Design: This study involved 49 patients with stage IIIb bulky and stage IVa cervical cancer treated with high LET carbon beams between October 1995 and June 2000. Oxygen partial pressure (pO2) was measured by using a needle-type polarographic oxygen electrode.

Results: The 4-year disease-free survival rates of patients with pO2 ≤ 20 mm Hg (hypoxic tumor) and pO2 > 20 mm Hg (oxygenated tumor) before treatment were 37% and 21%, respectively. The local control rates of hypoxic and oxygenated tumors before treatment were 58% and 54%, respectively. The disease-free survival rates of hypoxic and oxygenated tumors assessed by oxygen status at the 5th day of irradiation were 33% and 32%, respectively. The local control rates of hypoxic and oxygenated tumors at the 5th day were 60% and 58%, respectively. There was no significant prognostic difference between hypoxic and oxygenated tumors.

Conclusion: The similar disease-free survival and local control rates between hypoxic and oxygenated tumors before and during treatment indicated that the role of the tumor oxygenation status was not so important in local control in carbon beam therapy. These results indicated that high LET carbon beam irradiation might reduce the radiation-resistant nature stemming from tumor hypoxia.
Phase II Trial of Celecoxib in Prostate-Specific Antigen Recurrent Prostate Cancer after Definitive Radiation Therapy or Radical Prostatectomy
Authors: Pruthi Raj S. , Derksen J. Eric , Moore Dominic , Carson Culley C. , Grigson Gayle , Watkins Cathy , Wallen Eric
Published: April 2006

Objectives: Recent evidence has shown that cyclooxygenase-2 (COX-2) inhibitors have potent antitumor activity in prostate cancer both in vitro and in vivo. However, human trials are absent. This study evaluated the efficacy of the COX-2 inhibitor celecoxib in prostate-specific antigen (PSA) recurrent prostate cancer after radiation therapy (X-ray therapy or XRT) or radical prostatectomy.

Methods: Forty patients who had biochemical relapse after XRT or radical prostatectomy were treated with celecoxib 400 mg twice per day. Follow-up PSA levels were obtained at 3, 6, 12, and 18 months and subsequently every 6 months thereafter. Data were evaluated by calculating PSA doubling times and by calculating the slope of the curve of log(PSA) versus time to assess rate of PSA increase before and after celecoxib treatment for each patient.

Results: Thirty-six of 40 (90%) patients had a slowing effect on their rate of PSA after 3 months, including 11 of 40 with a decline and 8 of 40 with stabilization of PSA. Short-term responses at 3 months continued at 6, 12, 18 months. Comparison of rate of PSA increase before versus after celecoxib treatment showed significant flattening of slope of log(PSA) versus time from pretreatment for each of the time points. There was no significant change in testosterone levels, suggesting an androgen-independent mechanism.

Conclusions: COX-2 inhibitors may have an effect on serum PSA levels in patients with biochemical progression after XRT or radical prostatectomy. These results suggest that COX-2 inhibitors may help delay or prevent disease progression in these patients and thereby help extend the time until androgen deprivation therapy.
Preclinical Efficacy and Pharmacokinetics of AP5346, A Novel Diaminocyclohexane-Platinum Tumor-Targeting Drug Delivery System
Authors: Rice John R. , Gerberich Jennifer L. , Nowotnik David P. , Howell Stephen B.
Published: April 2006

Purpose: AP5346 is designed to target a diaminocyclohexane platinum (Pt) moiety to tumors through pH-sensitive linkage to a 25 kDa hydroxypropylmethacrylamide polymer. The goal of these studies was to determine the rate of release of Pt as a function of pH, the antitumor activity, and plasma and tumor pharmacokinetics of AP5346 in preclinical models.

Experimental Design: Antitumor activity was assessed in mice bearing B16F10 melanoma and M5076 and 2008 ovarian carcinomas. Pt levels in plasma, tumors, and tumor DNA were measured by atomic absorption and inductively coupled plasma mass spectrometry.

Results: AP5346 did not release Pt when suspended in 5% dextrose and released only 3.5% of its Pt in 24 hours in buffer at pH 7.4; the rate of release was 7-fold higher at pH 5.4. When given at their respective maximum tolerated doses, the antitumor activity of AP5346 was superior to that of oxaliplatin against both the B16 melanoma and 2008 human ovarian carcinoma. It was more effective than cisplatin in both cisplatin-sensitive and cisplatin-resistant variants of the M5076 tumor. When given at equitoxic doses, the peak plasma concentration was 25-fold higher, and AUC(0-∞) was 93 times higher, for AP5346 than for oxaliplatin. AP5346 delivered 16.3-fold more Pt to the tumor and 14.2-fold more Pt to tumor DNA than oxaliplatin based on AUC(1-168).

Conclusions: AP5346 has a substantially better therapeutic index than oxaliplatin. AP5346 produced a marked increase in the delivery of diaminocyclohexane Pt to the tumor and tumor DNA over and above that attainable with oxaliplatin.
Effects of Smoking on the Pharmacokinetics of Erlotinib
Authors: Hamilton Marta , Wolf Julie L. , Rusk Jason , Beard Shannon E. , Clark Gary M. , Witt Karsten , Cagnoni Pablo J.
Published: April 2006

Purpose: To compare the pharmacokinetic variables of erlotinib in current smokers with nonsmokers after receiving a single oral 150 or 300 mg dose of erlotinib.

Experimental Design: This was a single-center, open-label pharmacokinetic study in healthy male subjects. Subjects were enrolled into two treatment cohorts based on smoking status (current smokers and nonsmokers). The pharmacokinetic profile for erlotinib and its metabolite, OSI-420, was determined for each subject following each treatment.

Results: Current smokers achieved significantly less erlotinib exposure following a single 150 or 300 mg dose than nonsmokers. Following the 150 mg dose, the geometric mean erlotinib AUC0-∞ in smokers was 2.8-fold lower than in nonsmokers and similar to that of nonsmokers at the 300 mg dose. Cmax in smokers was two-thirds of that in nonsmokers, and C24h in smokers was 8.3-fold lower than in nonsmokers. The median C24h of smokers at the 300 mg dose was slightly less than the C24h of smokers at the 150 mg dose. The median Cmax was greater in smokers at the 300 mg dose than in nonsmokers at the 150 mg dose.

Conclusion: This study confirms that the pharmacokinetics of erlotinib is different in current smokers and nonsmokers. The observation that AUC0-∞ and C24h were significantly decreased in smokers compared with nonsmokers, and a smaller decrease in Cmax was observed, is consistent with increased metabolic clearance of erlotinib in current smokers.
Synergistic Interactions between DMAG and Mitogen-Activated Protein Kinase Kinase 1/2 Inhibitors in Bcr/abl+ Leukemia Cells Sensitive and Resistant to Imatinib Mesylate
Authors: Nguyen Tri K. , Rahmani Mohamed , Gao Ning , Kramer Lora , Corbin Amie S. , Druker Brian J. , Dent Paul , Grant Steven
Published: April 2006

Purpose: To characterize interactions between the heat shock protein 90 antagonist 17-dimethylaminoethylamino-17-demethoxygeldanamycin (DMAG) and the mitogen-activated protein kinase/extracellular signal–regulated kinase (ERK) kinase 1/2 inhibitor PD184352 in Bcr/abl+ leukemia cells sensitive and resistant to imatinib mesylate.

Experimental Design: K562 and LAMA 84 cells were exposed to varying concentrations of DMAG and PD184352 for 48 hours; after which, mitochondrial integrity, caspase activation, and apoptosis were monitored. Parallel studies were done in imatinib mesylate–resistant cells, including BaF3 cells transfected with plasmids encoding clinically relevant Bcr/abl mutations conferring imatinib mesylate resistance (e.g., E255K, M351T, and T315I) and primary CD34+ bone marrow cells from patients refractory to imatinib mesylate.

Results: Cotreatment of Bcr/abl+ cells with minimally toxic concentrations of DMAG and PD184352 resulted in synergistic induction of mitochondrial injury (cytochrome c release and Bax conformational change), events associated with the pronounced and sustained inactivation of ERK1/2 accompanied by down-regulation of Bcl-xL. Conversely, cells ectopically expressing Bcl-xL displayed significant protection against PD184352/DMAG–mediated lethality. This regimen effectively induced apoptosis in K562 cells overexpressing Bcr/abl, in BaF3 cells expressing various clinically relevant Bcr/abl mutations, and in primary CD34+ cells from patients resistant to imatinib mesylate, but was relatively sparing of normal CD34+ bone marrow cells.

Conclusions: A regimen combining the heat shock protein 90 antagonist DMAG and the mitogen-activated protein kinase/ERK kinase 1/2 inhibitor potently induces apoptosis in Bcr/abl+ cells, including those resistant to imatinib mesylate through various mechanisms including Bcr/abl kinase mutations, through a process that may involve sustained ERK1/2 inactivation and Bcl-xL down-regulation. This strategy warrants further attention in Bcr/abl+ hematopoietic malignancies, particularly those resistant to Bcr/abl kinase inhibitors.
Erythropoietin Fails to Interfere with the Antiproliferative and Cytotoxic Effects of Antitumor Drugs
Authors: Gewirtz David A. , Di Xu , Walker Teneille D. , Sawyer Stephen T.
Published: April 2006

Purpose: Erythropoietin (EPO) therapy is widely used for the prevention and treatment of anemia resulting from cancer chemotherapy. Native EPO regulates erythropoiesis, at least in part, by protecting erythroid progenitor cells from apoptotic cell death. The recent discovery of the EPO receptor (EPOR) on cancer cells raises the concern that EPO therapy might stimulate tumor growth and/or protect cancer cells from drug-induced apoptosis. Therefore, the capacity of EPO to interfere with the effects of conventional chemotherapeutic drugs on proliferation, apoptosis, and the induction of senescence was investigated in MCF-7 and MDA-MB231 breast tumor cells, which express the EPOR as well as in F-MEL erythroleukemia cells.

Experimental Design: Breast cancer cells and F-MEL leukemic cells were cultured in the presence or absence of EPO and then exposed to antitumor drugs. Cell proliferation was assessed by a standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide dye reduction assay 72 hours after drug exposure. Cytotoxicity was monitored by clonogenic survival. Apoptosis was evaluated either by the terminal deoxyribonucleotide transferase–mediated nick-end labeling assay or fluorescence-activated cell sorting analysis, and senescence was monitored by β-galactosidase staining. EPO signaling was assessed by monitoring the phosphorylation/activation of specific signaling proteins.

Results: EPO failed to stimulate the proliferation of MCF-7 or MDA-MB231 breast tumor cells or F-MEL leukemic cells. EPO treatment also failed to interfere with the antiproliferative and/or cytotoxic effects of Adriamycin, Taxol, and tamoxifen in breast tumor cells (or of cytarabine and daunorubicin in F-MEL cells). EPO failed to prevent apoptosis induced by Taxol or senescence induced by Adriamycin in MCF-7 cells. EPO stimulated the activation of extracellular signal-regulated kinase, p38, and c-Jun-NH2-kinase in MCF-7 cells but did not activate Akt or signal transducers and activators of transcription 5 (STAT5). EPO failed to activate any of these signaling pathways in MDA-MB231 cells. Cytarabine and daunorubicin interfered with EPO signaling in F-MEL cells.

Conclusions: These findings suggest that EPO is unlikely to directly counteract the effectiveness of cancer chemotherapeutic drugs. This may be a consequence of either ineffective signaling through the EPOR or drug-mediated suppression of EPO signaling.