bluuebunny/crossref_metadata_2025 huggingface dataset:
The Determinants of Poverty in Georgia's Plantation Belt:
Authors: Levernier William , White John B.
Published: July 2006

ABSTRACT This paper analyzes the effect of various economic, demographic, human capital, and locational characteristics on the family poverty rate in Georgia's 159 counties. The primary focus of the paper is on whether being located within Georgia's “Plantation Belt,” a region that was primarily a plantation economy until after the Civil War, affects a county's family poverty rate today. Although family poverty rates in the 79 Plantation Belt counties are, on average, substantially higher than in the 80 counties outside the Plantation Belt, the Plantation Belt counties tend to have a lower poverty rate after economic, demographic, human capital, and metropolitan location characteristics are controlled for. In addition, separate regressions on the two groups of counties indicate that there are substantial differences in the effect that these factors have on the family poverty rate.
On Financial Frauds and Their Causes
Authors: Pressman Steven
Published: July 2006

Abstract This paper examines two possible explanations for why investors are so often and so easily taken by the likes of Robert Bennett and his New Era fraud or Nick Leeson's sinking of the esteemed Barings Bank. I rule out the traditional explanations offered by neoclassical economics such as asymmetric information in a world of calculable risk. I argue that the literature on empirical psychology, which emphasizes how people make choices in a world characterized by uncertainty provides a more plausible explanation for why financial fraud is so prevelant. The paper emphasizes the interdisciplinary aspects of financial frauds and concludes with some policy prescriptions for preventing financial fraud.
The Reality of Brands:
Authors: Grassi Wolfgang
Published: July 2006

Abstracthe ontology of marketing, particularly the question of what products and brands are, is still largely unexplored. The ontological status of brands hinges on their relationship with products. Idealists about brands see perceptual or cognitive acts of consumers grouped under the heading brand awarencess' or ‘brand image’ as constitutive for the existence of brands so that, in their view, tools of the marketing mix can influence relevant mental dispositions and attitudes. Brand realists, on the other hand reject the view of brands as mere marks or names and interpret them as emergent products with properties that afford branding in the sense of Gibson's ecological psychology. Brand strength is a function of the degree to which brands occupy defensible niches in product space. Branding as a process involves changing external or internal boundaries of products. Several arguments are proposed in favor of brand realism. The fragments of an ontology of marketing are developed in a broadly Aristotelian framework. Brand realism has significant implications for a new understanding of issues ranging from the effects of advertising to financial brand valuation, the nature of trademarks, and marketing strategy in general. It permits one to treat brand equity as a real phenomenon not dependent on associations, attitudinal states such as brand loyalty, or spurious constructs such as brand character or personality.
Economy and Race: Interactive Determinants of Property Crime in the United States, 1958‐1995
Authors: Ralston Roy W.
Published: July 2006

ABSTRACT Drawing upon rational choice, routine activity, and social disorganization theories, this study investigates changes in rates of property crime known (reported) to police in the United States from 1958 to 1995. Predictor variables include changes in rates of inflation; technological, cyclical, and frictional unemployment; arrest rates for property crimes disaggregated by race (ARPCDR); the interaction of ARPCDR and technological unemployment (to test effects of rising unemployment on whites versus blacks); and a measure of police provisioning. A Beach‐MacKinnon Full Maximum‐Likelihood FGLS AR1 Method (accompanied by residual analysis) is employed. Significant positive effects are established for (a) inflation, (b) cyclical unemployment, (c) frictional unemployment, and (d) the interaction of white arrest rates and technological unemployment. Police provisioning is not found to be significant. Policy implications are explored along with future policy considerations.
Performance Appraisal, Performance Management and Improving Individual Performance: A Motivational Framework
Authors: DeNisi Angelo S. , Pritchard Robert D.
Published: June 2006

Performance appraisal has been the focus of considerable research for almost a century. Yet, this research has resulted in very few specific recommendations about designing and implementing appraisal and performance management systems whose goal is performance improvement. We believe that a reason for this is that appraisal research became too interested in measurement issues and not interested enough in ways to improve performance, although some recent trends in the area have begun moving the field in the right direction. We review these trends and their genesis, and propose a motivational framework as a means of integrating what we have learned and generating proposals for future research that focus on employee's performance improvement.
Variability in agreement between physicians and nurses when measuring the Glasgow Coma Scale in the emergency department limits its clinical usefulness
Authors: Holdgate Anna , Ching Natasha , Angonese Lara
Published: June 2006

Objective:  To assess the interrater reliability of the Glasgow Coma Scale (GCS) between nurses and senior doctors in the ED.

Methods:  This was a prospective observational study with a convenience sample of patients aged 18 or above who presented with a decreased level of consciousness to a tertiary hospital ED. A senior ED doctor (emergency physicians and trainees) and registered nurse each independently scored the patient’s GCS in blinded fashion within 15 min of each other. The data were then analysed to determine interrater reliability using the weighted kappa statistic and the size and directions of differences between paired scores were examined.

Results:  A total of 108 eligible patients were enrolled, with GCS scores ranging from 3 to 14. Interrater agreement was excellent (weighted kappa > 0.75) for verbal scores and total GCS scores, and intermediate (weighted kappa 0.4–0.75) for motor and eye scores. Total GCS scores differed by more than two points in 10 of the 108 patients. Interrater agreement did not vary substantially across the range of actual numeric GCS scores.

Conclusions:  Although the level of agreement for GCS scores was generally high, a significant proportion of patients had GCS scores which differed by two or more points. This degree of disagreement indicates that clinical decisions should not be based solely on single GCS scores.
Compressions: Australian Resuscitation Council Guideline 2006
Authors:   Australian Resuscitation Council
Published: June 2006

This guideline is applicable to adults, children and infants.

6 Compressions
Cardiopulmonary resuscitation training: Australian Resuscitation Council Guideline 2004
Authors:   Australian Resuscitation Council
Published: June 2006

9.1.1 Cardiopulmonary Resuscitation Training
Adult advanced life support: Australian Resuscitation Council Guidelines 2006
Authors:   Australian Resuscitation Council
Published: June 2006

11.1 Introduction to Advanced Life Support

11.2 Protocols for Adult Advanced Life Support

11.3 Precordial Thump & Fist Pacing

11.4 Cricoid Pressure

11.5 Electrical Therapy for Adult Advanced Life Support

11.6 Medications in Adult Cardiac Arrest

11.7 Equipment and Techniques in Adult Advanced Life Support

11.8 Post‐Resuscitation Therapy in Adult Advanced Life Support

11.9 Therapeutic Hypothermia After Cardiac Arrest

11.10 Legal and Ethical Issues Related to Resuscitation

11.11 First Responder
Analysis of HLA‐DQB1 gene polymorphisms in asymptomatic HBV carriers and chronic hepatitis B patients in the Chinese Han population
Authors: Xi‐Lin Z. , Te D. , Jun‐Hong L. , Liang‐Ping L. , Xin‐Hui G. , Ji‐Rong G. , Chun‐Yan G. , Zhuo L. , Ying L. , Hui L.
Published: July 2006

Host genetic factors and environment factors including hepatitis B virus (HBV) genotype are widely viewed as common basis of the different outcomes of HBV infection. Human leucocyte antigen (HLA) plays an important role in immunological reaction to HBV infection.

The study aimed to explore whether the HLA‐DQB1 allele polymorphisms are associated with the outcomes of HBV infection in the Chinese Han population.

One hundred and thirty‐four asymptomatic HBV carriers and 139 chronic hepatitis B patients were recruited in this case‐control study in Beijing, China.

Sequence‐specific primers–polymerase chain reaction was used to detect 13 alleles of HLA‐DQB1 gene. The frequency distributions of alleles in two groups were analysed using sas 9.1.2 software. After adjustment of confounders the frequencies of HLA‐DQB1*0503 allele and *0303 allele in chronic hepatitis B group were statistically significant lower than those in asymptomatic HBV carrier group (P = 0.04; P = 0.05), and the frequency of exposure to alcohol consumption in patients with chronic hepatitis B was clearly higher than that in asymptomatic HBV carrier group (P = 0.004).

HLA‐DQB1*0503 allele and *0303 allele are independently resistant genetic factors to chronic hepatitis B, and alcohol consumption is the risk factor of chronic hepatitis B.
Infection of Naïve Target Cells with Virus-Like Particles: Implications for the Function of Ebola Virus VP24
Authors: Hoenen Thomas , Groseth Allison , Kolesnikova Larissa , Theriault Steven , Ebihara Hideki , Hartlieb Bettina , Bamberg Sandra , Feldmann Heinz , Ströher Ute , Becker Stephan
Published: June 2006

Infectious virus-like particle (iVLP) systems have recently been established for several negative-strand RNA viruses, including the highly pathogenic
Zaire ebolavirus
(ZEBOV), and allow study of the viral life cycle under biosafety level 2 conditions. However, current systems depend on the expression of viral helper nucleocapsid proteins in target cells, thus making it impossible to determine whether ribonucleoprotein complexes transferred by iVLPs are able to facilitate initial transcription, an indispensable step in natural infection. Here we describe a ZEBOV iVLP system which overcomes this limitation and show that VP24 is essential for the formation of a functional ribonucleoprotein complex.
Characterization of the Multiple Conformational States of Free Monomeric and Trimeric Human Immunodeficiency Virus Envelope Glycoproteins after Fixation by Cross-Linker
Authors: Yuan Wen , Bazick Jessica , Sodroski Joseph
Published: June 2006

The human immunodeficiency virus type 1 (HIV-1) gp120 exterior and gp41 transmembrane envelope glycoproteins assemble into trimers on the virus surface that represent potential targets for antibodies. Potent neutralizing antibodies bind the monomeric gp120 glycoprotein with small changes in entropy, whereas unusually large decreases in entropy accompany gp120 binding by soluble CD4 and less potent neutralizing antibodies. The high degree of conformational flexibility in the free gp120 molecule implied by these observations has been suggested to contribute to masking the trimer from antibodies that recognize the gp120 receptor-binding regions. Here we use cross-linking and recognition by antibodies to investigate the conformational states of gp120 monomers and soluble and cell surface forms of the trimeric HIV-1 envelope glycoproteins. The fraction of monomeric and trimeric envelope glycoproteins able to be recognized after fixation was inversely related to the entropic changes associated with ligand binding. In addition, fixation apparently limited the access of antibodies to the V3 loop and gp41-interactive surface of gp120 only in the context of trimeric envelope glycoproteins. The results support a model in which the unliganded monomeric and trimeric HIV-1 envelope glycoproteins sample several different conformations. Depletion of particular fixed conformations by antibodies allowed characterization of the relationships among the conformational states. Potent neutralizing antibodies recognize the greatest number of conformations and therefore can bind the virion envelope glycoproteins more rapidly and completely than weakly neutralizing antibodies. Thus, the conformational flexibility of the HIV-1 envelope glycoproteins creates thermodynamic and kinetic barriers to neutralization by antibodies directed against the receptor-binding regions of gp120.
Hepatitis C Virus Triggers Mitochondrial Permeability Transition with Production of Reactive Oxygen Species, Leading to DNA Damage and STAT3 Activation
Authors: Machida Keigo , Cheng Kevin T.-H. , Lai Chao-Kuen , Jeng King-Song , Sung Vicky M.-H. , Lai Michael M. C.
Published: June 2006

Hepatitis C virus (HCV) infection is frequently associated with the development of hepatocellular carcinomas and non-Hodgkin's B-cell lymphomas. Previously, we reported that HCV infection causes cellular DNA damage and mutations, which are mediated by nitric oxide (NO). NO often damages mitochondria, leading to induction of double-stranded DNA breaks (DSBs) and accumulation of oxidative DNA damage. Here we report that HCV infection causes production of reactive oxygen species (ROS) and lowering of mitochondrial transmembrane potential (ΔΨm) in in vitro HCV-infected cell cultures. The changes in membrane potential could be inhibited by BCL-2. Furthermore, an inhibitor of ROS production, antioxidantN-acetyl-l-cysteine (NAC), or an inhibitor of NO, 1400W, prevented the alterations of ΔΨm. The HCV-induced DSB was also abolished by a combination of NO and ROS inhibitors. These results indicated that the mitochondrial damage and DSBs in HCV-infected cells were mediated by both NO and ROS. Among the HCV proteins, core, E1, and NS3 are potent ROS inducers: their expression led to DNA damage and activation of STAT3. Correspondingly, core-protein-transgenic mice showed elevated levels of lipid peroxidation and oxidatively damaged DNA. These HCV studies thus identified ROS, along with the previously identified NO, as the primary inducers of DSBs and mitochondrial damage in HCV-infected cells.
Induction of Lactoferrin Gene Expression in Myeloid or Mammary Gland Cells by Human T-Cell Leukemia Virus Type 1 (HTLV-1) Tax: Implications for Milk-Borne Transmission of HTLV-1
Authors: Moriuchi Masako , Moriuchi Hiroyuki
Published: June 2006

Human T-cell leukemia virus type 1 (HTLV-1), the causative agent of adult T-cell leukemia, is transmitted vertically via breastfeeding. We have previously demonstrated that lactoferrin, a major milk protein, enhances HTLV-1 replication, at least in part by upregulating the HTLV-1 long terminal repeat promoter. We now report that HTLV-1 infection can induce lactoferrin gene expression. Coculture with HTLV-1-infected MT-2 cells increased the levels of lactoferrin mRNA in myeloid-differentiated HL-60 cells, as well as MCF-7 cells, models of two probable sources (neutrophils and mammary epithelium) of lactoferrin in breast milk. MT-2 cell coculture could be replaced with cell-free culture supernatants of MT-2 cells to exert the same effect. Furthermore, extracellularly administered Tax protein also induced lactoferrin gene expression at physiologically relevant concentrations. In transient-expression assays, Tax transactivated the lactoferrin gene promoter in HL-60 or MCF-7 cells. Experiments with Tax mutants, as well as site-directed mutants of the lactoferrin promoter reporters, indicated that the NF-κB transactivation pathway is critical for Tax induction of the lactoferrin gene promoter activity in myeloid-differentiated HL-60 cells, but not in MCF-7 cells. These results suggest that HTLV-1 infection may be able to induce expression of lactoferrin in a paracrine manner in the lactic compartment. Our findings, in conjunction with our previous study, implicate that mutual interaction between HTLV-1 and lactoferrin would benefit milk-borne transmission of this virus.
Neuropilin-1 Is Involved in Human T-Cell Lymphotropic Virus Type 1 Entry
Authors: Ghez David , Lepelletier Yves , Lambert Sophie , Fourneau Jean-Marie , Blot Vincent , Janvier Sébastien , Arnulf Bertrand , van Endert Peter M. , Heveker Nikolaus , Pique Claudine , Hermine Olivier
Published: June 2006

Human T-cell lymphotropic virus type 1 (HTLV-1) is transmitted through a viral synapse and enters target cells via interaction with the glucose transporter GLUT1. Here, we show that Neuropilin-1 (NRP1), the receptor for semaphorin-3A and VEGF-A165 and a member of the immune synapse, is also a physical and functional partner of HTLV-1 envelope (Env) proteins. HTLV-1 Env and NRP1 complexes are formed in cotransfected cells, and endogenous NRP1 contributes to the binding of HTLV-1 Env to target cells. NRP1 overexpression increases HTLV-1 Env-dependent syncytium formation. Moreover, overexpression of NRP1 increases both HTLV-1 and HTLV-2 Env-dependent infection, whereas down-regulation of endogenous NRP1 has the opposite effect. Finally, overexpressed GLUT1, NRP1, and Env form ternary complexes in transfected cells, and endogenous NRP1 and GLUT1 colocalize in membrane junctions formed between uninfected and HTLV-1-infected T cells. These data show that NRP1 is involved in HTLV-1 and HTLV-2 entry, suggesting that the HTLV receptor has a multicomponent nature.
Disruption of α-actinin-integrin interactions at focal adhesions renders osteoblasts susceptible to apoptosis
Authors: Triplett Jason W. , Pavalko Fredrick M.
Published: June 2006

Maintenance of bone structural integrity depends in part on the rate of apoptosis of bone-forming osteoblasts. Because substrate adhesion is an important regulator of apoptosis, we have investigated the role of focal adhesions in regulating bone cell apoptosis. To test this, we expressed a truncated form of α-actinin (ROD-GFP) that competitively displaces endogenous α-actinin from focal adhesions, thus disrupting focal adhesions. Immunofluorescence and morphometric analysis of vinculin and tyrosine phosphorylation revealed that ROD-GFP expression dramatically disrupted focal adhesion organization and reduced tyrosine phosphorylation at focal adhesions. In addition, Bcl-2 protein levels were reduced in ROD-GFP-expressing cells, but caspase 3 cleavage, poly(ADP-ribose) polymerase cleavage, histone H2A.X phosphorylation, and cytotoxicity were not increased due to ROD-GFP expression alone. Increases in both ERK and Akt phosphorylation were also observed in ROD-GFP-expressing cells, although inhibition of either ERK or Akt individually or together failed to induce apoptosis. However, we did find that ROD-GFP expression sensitized, whereas α-actinin-GFP expression protected, cells from TNF-α-induced apoptosis. Further investigation revealed that activation of TNF-α-induced survival signals, specifically Akt phosphorylation and NF-κB activation, was inhibited in ROD-GFP-expressing cells. The reduced expression of antiapoptotic Bcl-2 and inhibited survival signaling rendered ROD-GFP-expressing cells more susceptible to TNF-α-induced apoptosis. Thus we conclude that α-actinin plays a role in regulating cell survival through stabilization of focal adhesions and regulation of TNF-α-induced survival signaling.
Endocannabinoid-Mediated Depolarization-Induced Suppression of Inhibition in Hilar Mossy Cells of the Rat Dentate Gyrus
Authors: Hofmann Mackenzie E. , Nahir Ben , Frazier Charles J.
Published: June 2006

Hilar mossy cells represent a unique population of local circuit neurons in the hippocampus and dentate gyrus. Here we use electrophysiological techniques in acute preparations of hippocampal slices to demonstrate that depolarization of a single hilar mossy cell can produce robust inhibition of local GABAergic afferents. This depolarization-induced suppression of inhibition (DSI) can be observed as a transient reduction in frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) or as a transient reduction in amplitude of evoked IPSCs (eIPSCs). We find that DSI of eIPSCs as observed in hilar mossy cells is enhanced by activation of muscarinic acetylcholine receptors, blocked by chelation of postsynaptic calcium, and critically dependent on retrograde activation of presynaptic cannabinoid type 1 (CB1) receptors. We further report that activation of CB1 receptors on GABAergic afferents to hilar mossy cells (by either endogenous or exogenous agonists) preferentially inhibits calcium-dependent exocytosis and that endocannabinoid-dependent retrograde signaling in this system is subject to tight spatial constraints.
A Distinct p53 Protein Isoform Signature Reflects the Onset of Induction Chemotherapy for Acute Myeloid Leukemia
Authors: Anensen Nina , Oyan Anne Margrete , Bourdon Jean-Christophe , Kalland Karl Henning , Bruserud Oystein , Gjertsen Bjorn Tore
Published: July 2006

Purpose: The antioncogene protein product p53 has not been studied previously in cancer patients during in vivo chemotherapy. This study examined the early p53 protein and gene expression during induction chemotherapy in acute myeloid leukemia (AML).

Experimental Design: Leukemic cells were collected from five AML patients during their first 18 hours of induction chemotherapy and examined for p53 protein and gene expression by one- and two-dimensional gel immunoblot and high-density gene expression arrays.

Results: Up-regulation of p53 protein expression was detected in AML patients posttreatment in vivo. One- and two-dimensional gel immunoblots showed two main forms of p53, denominated αp53 and Δp53, both recognized by various NH2-terminal directed antibodies. As a response to treatment, we detected rapid accumulation of αp53, with significantly altered protein expression levels already after 2 hours. The accumulation of αp53 was accompanied by increased transcription of putative p53 target genes and subsequent cytopenia in the patients.

Conclusion: Up-regulation of the p53 protein and target genes seems to be a prominent feature in induction chemotherapy of AML. The rapid shift from a shorter p53 protein form (Δ) toward the full-length protein (α) underscores the complexity of p53 protein modulation in patients undergoing chemotherapy.
Signaling via ErbB2 and ErbB3 Associates with Resistance and Epidermal Growth Factor Receptor (EGFR) Amplification with Sensitivity to EGFR Inhibitor Gefitinib in Head and Neck Squamous Cell Carcinoma Cells
Authors: Erjala Kaisa , Sundvall Maria , Junttila Teemu T. , Zhang Na , Savisalo Mika , Mali Pekka , Kulmala Jarmo , Pulkkinen Jaakko , Grenman Reidar , Elenius Klaus
Published: July 2006

Purpose: The epidermal growth factor receptor (EGFR) inhibitor gefitinib (Iressa) has shown antitumor activity in clinical trials against cancers, such as non–small cell lung cancer and head and neck squamous cell carcinoma (HNSCC). Research on non–small cell lung cancer has elucidated factors that may predict response to gefitinib. Less is known about molecular markers that may predict response to gefitinib in HNSCC patients.

Experimental Design: We analyzed possible associations of responsiveness to gefitinib with molecular markers of the EGFR/ErbB receptor family signaling pathway using 10 established HNSCC lines in vitro. IC50 of gefitinib sensitivity was determined using clonogenic survival assays. ErbB signaling was assessed by Western and real-time reverse transcription-PCR analyses of EGFR, ErbB2, ErbB3, and ErbB4 expression levels as well as by phosphorylation analysis of pEGFR, pErbB2, pErbB3, pAkt, and pErk. EGFR sequences encoding kinase domain and EGFR gene copy numbers were determined by cDNA sequencing and real-time PCR, respectively. Finally, responsiveness to gefitinib was compared with responsiveness to the anti-EGFR antibody cetuximab (Erbitux).

Results: Expression levels of pErbB2 (P = 0.02) and total ErbB3 protein (P = 0.02) associated with resistance to gefitinib. Combining gefitinib with pertuzumab (Omnitarg), an antibody targeting ErbB2 heterodimerization, provided additional growth-inhibitory effect over gefitinib alone on relatively gefitinib-resistant HNSCC cell lines. The same markers did not predict resistance to cetuximab. In contrast, a similar trend suggesting association between EGFR gene copy number and drug sensitivity was observed for both gefitinib (P = 0.0498) and cetuximab (P = 0.053). No activating EGFR mutations were identified.

Conclusions: EGFR amplification may predict sensitivity to gefitinib in HNSCC. However, other EGFR/ErbB receptor family members than EGFR may contribute to resistance to gefitinib. ErbB2 and ErbB3 may have potential as predictive markers and as therapeutic targets for combination therapy in treatment of HNSCC with gefitinib.
Captopril, an Angiotensin-Converting Enzyme Inhibitor, Promotes Growth of Immunogenic Tumors in Mice
Authors: Wysocki Piotr J. , Kwiatkowska Eliza P. , Kazimierczak Urszula , Suchorska Wiktoria , Kowalczyk Dariusz W. , Mackiewicz Andrzej
Published: July 2006

Purpose: Antitumor potential of angiotensin-converting enzyme inhibitors has been shown in different preclinical settings, which always involved immunocompromised organisms or nonimmunogenic tumor models. In our study, we wanted to evaluate the effect of captopril on growth of immunogenic tumors in immunocompetent animals.

Experimental Design: We used different murine tumor models to evaluate the effect of captopril on tumor take and survival of tumor-bearing immunocompetent and immunocompromised mice. We used an orthotopic renal cell cancer model and highly immunogenic tumor model, which were based on kidney subcapsular injection of RenCa cells or s.c. injection of MethA cells, respectively. To show the influence of captopril on antigen-specific immune responses, we have used two model antigens (green fluorescent protein and β-galactosidase).

Results: Captopril decreased survival of RenCa-bearing, immunocompetent mice in a dose-dependent manner and in adjuvant setting. In nephrectomized mice, captopril shortened their survival. Captopril promoted formation of immunogenic MethA sarcoma tumors but had no effect on nonimmunogenic melanoma cells (B78-H1). Treatment of immunocompromised mice bearing MethA tumors or RenCa kidney tumors with captopril did not affect tumor formation nor survival, respectively. Captopril-treated mice immunized with AdLacZ or AdGFP vectors did not generate or generated decreased numbers of antigen-specific CD8+ T cells, respectively. However, they showed B-cell responses represented by infiltration of MethA tumors with activated B cells and dramatically increased serum level of β-galactosidase-specific antibodies.

Conclusions: Our results show a novel role of captopril in tumor biology and the tumor-promoting properties of captopril seem to be associated with its immunomodulatory potential.
Humanization of the Bispecific Epidermal Growth Factor Receptor × CD3 Diabody and Its Efficacy as a Potential Clinical Reagent
Authors: Asano Ryutaro , Sone Yukiko , Makabe Koki , Tsumoto Kouhei , Hayashi Hiroki , Katayose Yu , Unno Michiaki , Kudo Toshio , Kumagai Izumi
Published: July 2006

Purpose: Bispecific antibodies (BsAb) have been exploited as both cancer immunodiagnostics and cancer therapeutics and show promise in clinical trials of cancer imaging and therapy. For development of BsAbs as clinical reagents, we have focused on construction of small recombinant BsAbs, called bispecific diabodies. Here, we constructed and characterized a humanized bispecific diabody.

Experimental Design: We have reported significant antitumor activity of an anti-epidermal growth factor receptor (EGFR) × anti-CD3 bispecific diabody (Ex3) in in vitro cytotoxicity assays and in vivo. We humanized the Ex3 diabody (hEx3) by grafting the complementarity-determining region and compared its biological properties with those of Ex3. We also tested its physiologic stability and ability to alter survival in xenografted mice.

Results: The final yield of hEx3 was 10 times that of Ex3, and refolded hEx3 and Ex3 showed identical binding profiles in EGFR-positive cell lines and EGFR-transfected Chinese hamster ovary cells. hEx3 showed dose-dependent cytotoxicity to EGFR-positive cell lines, which could be specifically inhibited by parental monoclonal antibody IgGs against EGFR or CD3 antigens. The heterodimeric structure was retained in PBS for 6 months, and growth inhibition was maintained after incubation under physiologic conditions. Coadministration of hEx3 with T-LAK cells and interleukin-2 prolonged the survival of nude mice with human colon carcinoma.

Conclusions: The humanized diabody hEx3 is an attractive molecule for cancer therapy and may provide important insights into the development of EGFR-based cancer-targeting reagents.
Positron Emission Tomography Using [18F]Galacto-RGD Identifies the Level of Integrin αvβ3 Expression in Man
Authors: Beer Ambros J. , Haubner Roland , Sarbia Mario , Goebel Michael , Luderschmidt Stephan , Grosu Anca Ligia , Schnell Oliver , Niemeyer Markus , Kessler Horst , Wester Hans-Jürgen , Weber Wolfgang A. , Schwaiger Markus
Published: July 2006

Purpose: The integrin αvβ3 plays a key role in angiogenesis and tumor cell metastasis and is therefore an important target for new therapeutic and diagnostic strategies. We have developed [18F]Galacto-RGD, a highly αvβ3-selective tracer for positron emission tomography (PET). Here, we show, in man, that the intensity of [18F]Galacto-RGD uptake correlates with αvβ3 expression.

Experimental Design: Nineteen patients with solid tumors (musculoskeletal system, n = 10; melanoma, n = 4; head and neck cancer, n = 2; gliobastoma, n = 2; and breast cancer, n = 1) were examined with PET using [18F]Galacto-RGD before surgical removal of the tumor lesions. Snap-frozen specimens (n = 26) were collected from representative areas with low and intense standardized uptake values (SUV) of [18F]Galacto-RGD. Immunohistochemistry was done using the αvβ3-specific antibody LM609. Intensity of staining (graded on a four-point scale) and the microvessel density of αvβ3-positive vessels were determined and correlated with SUV and tumor/blood ratios (T/B).

Results: Two tumors showed no tracer uptake (mean SUV, 0.5 ± 0.1). All other tumors showed tracer accumulation with SUVs ranging from 1.2 to 10.0 (mean, 3.8 ± 2.3; T/B, 3.4 ± 2.2; tumor/muscle ratio, 7.7 ± 5.4). The correlation of SUV and T/B with the intensity of immunohistochemical staining (Spearman's r = 0.92; P < 0.0001) as well as with the microvessel density (Spearman's r = 0.84; P < 0.0001) were significant. Immunohistochemistry confirmed lack of αvβ3 expression in normal tissue (benign lymph nodes, muscle) and in the two tumors without tracer uptake.

Conclusions: Molecular imaging of αvβ3 expression with [18F]Galacto-RGD in humans correlates with αvβ3 expression as determined by immunohistochemistry. PET with [18F]Galacto-RGD might therefore be used as a new marker of angiogenesis and for individualized planning of therapeutic strategies with αvβ3-targeted drugs.
A Phase I Study of Ultra Low Dose Interleukin-2 and Stem Cell Factor in Patients with HIV Infection or HIV and Cancer
Authors: Shah Manisha H. , Freud Aharon G. , Benson Don M. , Ferkitich Amy K. , Dezube Bruce J. , Bernstein Zale P. , Caligiuri Michael A.
Published: July 2006

Purpose: Ultra low doses of interleukin-2 (IL-2) can activate the high-affinity IL-2 receptor constitutively expressed on CD56bright natural killer (NK) cells, the CD34+ NK cell precursor, and CD4+CD25+ regulatory T cells (Tregs) in vivo. We have previously shown synergy between IL-2 and stem cell factor (SCF) in the generation of CD56bright NK cells from CD34+ hemopoietic progenitor cells in vitro and showed synergistic NK cell expansion in an in vivo preclinical model. To determine the safety, toxicity, and immune modulation of this combination of cytokines in vivo, we conducted a first-in-man phase I study.

Experimental Design: A phase I dose escalation study was conducted using IL-2 at 900,000 or 650,000 IU/m2/d for 8 weeks with 5 or 10 μg/kg/d of SCF given thrice a week for 8 weeks in patients with HIV infection and/or cancer.

Results: Ten of 13 patients completed therapy; four experienced the dose-limiting toxicities of grade 3 fatigue or urticaria. The maximum tolerated doses of IL-2 and SCF in combination is 650,000 IU/m2/d of IL-2 and 5 μg/kg/d thrice a week of SCF. NK cells were expanded over 2-fold on therapy; Tregs were expanded nearly 6-fold from baseline.

Conclusions: Administration of IL-2 with SCF is safe and well tolerated and leads to expansion of lymphocyte subsets in patients with HIV or HIV and cancer; however, the changes in NK cell and Treg expansion seen with this cytokine combination were no different than those seen with a similar dose of IL-2 alone.
Imatinib inhibits c-Kit-induced hypoxia-inducible factor-1α activity and vascular endothelial growth factor expression in small cell lung cancer cells
Authors: Litz Julie , Krystal Geoffrey W.
Published: July 2006

Vascular endothelial growth factor (VEGF) is one of the most important mediators of tumor angiogenesis. In addition to hypoxia, peptide growth factors are known to regulate VEGF expression but the effect of stem cell factor (SCF), the ligand for c-Kit, on VEGF expression has not been characterized. We therefore studied the effect of SCF-mediated c-Kit activation on VEGF expression by the H526 small cell lung cancer (SCLC) cell line. SCF treatment doubled VEGF mRNA expression and VEGF secretion in the absence of other exogenous growth factors, an effect efficiently blocked by imatinib. The increase in VEGF mRNA occurred within the first 2 hours of treatment and was not caused by alterations in mRNA stability. The phosphatidylinositol 3-kinase inhibitor LY294002 blocked the increase in VEGF mRNA, implicating c-Kit-mediated activation of phosphatidylinositol 3-kinase in the phenomenon. VEGF promoter-reporter transfections indicated that a SCF-mediated increase in VEGF promoter activity paralleled the increase in VEGF mRNA, documenting that SCF mediated its effects through enhanced VEGF transcription. Mutation of the core hypoxia-inducible factor (HIF)-1 binding element in the VEGF promoter significantly blunted SCF-responsiveness. SCF increased nuclear levels of the HIF-1α transcription factor, which correlated well with increased HIF-1α binding to a consensus hypoxia-responsive element. SCF-mediated effects on HIF-1α expression were additive with those produced by CoCl2, a hypoxia-mimetic agent. These data indicate that activation of c-Kit by SCF leads to a predominantly HIF-1α-mediated enhancement of VEGF expression and that inhibition of c-Kit signaling with imatinib could result in inhibition of tumor angiogenesis. [Mol Cancer Ther 2006;5(6):1415–22]
Pharmacogenetics of anticancer drug sensitivity in pancreatic cancer
Authors: Giovannetti Elisa , Mey Valentina , Nannizzi Sara , Pasqualetti Giuseppe , Del Tacca Mario , Danesi Romano
Published: July 2006

Chemotherapy has produced unsatisfactory results in pancreas cancer and novel approaches, including treatment tailoring by pharmacogenetic analysis and new molecular-targeted drugs, are required. The scarcity of effective therapies may reflect the lack of knowledge about the influence of tumor-related molecular abnormalities on responsiveness to drugs. Advances in the understanding of pancreas cancer biology have been made over the past decade, including the discovery of critical mutations in oncogenes (i.e., K-Ras) as well as the loss of tumor suppressor genes, such as TP53 and p16INK4. Other studies showed the dysregulation of the expression of proteins involved in the control of cell cycle, proliferation, apoptosis, and invasiveness, such as Bcl-2, Akt, mdm2, and epidermal growth factor receptor. These characteristics might contribute to the aggressive behavior of pancreatic cancer and influence response to treatment. Indeed, the inactivation of p53 may explain the relative resistance to 5-fluorouracil, whereas Bcl-2 overexpression is associated with reduced sensitivity to gemcitabine. However, the future challenge of pancreas cancer chemotherapy relies on the identification of molecular markers that help in the selection of drugs best suited to the individual patient. Recent pharmacogenetic studies focused on genes encoding proteins directly involved in drug activity, showing the role of thymidylate synthase and human equilibrative nucleoside transporter-1 as prognostic factor in 5-fluorouracil- and gemcitabine-treated patients, respectively. Finally, inhibitors of signal transduction and angiogenesis are under extensive investigation, and several prospective trials have been devoted to this area. Pharmacogenetics is likely to play a central role in the personalization of treatment, to stratify patients based on their likelihood of response to both standard agents (i.e., gemcitabine/nucleoside transporters) and targeted treatments (i.e., epidermal growth factor receptor gene mutations and/or amplification and tyrosine kinase inhibitors), Thus, molecular analysis should be implemented in the optimal management of the patient affected by pancreatic adenocarcinoma. [Mol Cancer Ther 2006;5(6):1387–95] [Mol Cancer Ther 2006;5(6):1387-95]
Constitutively active receptor tyrosine kinases as oncogenes in preclinical models for cancer therapeutics
Authors: Kellar Kristen A. , Lorenzi Matthew V. , Ho Ching Ping , You Dan , Wen Mei-Li , Ryseck Rolf P. , Oppenheimer Simone , Fink Brian E. , Vite Gregory D. , Rowley Bruce R. , Yu Chiang , Bol David K. , Lee Francis Y. , Wong Tai W.
Published: July 2006

Receptor tyrosine kinases (RTK) remain an area of therapeutic interest because of their role in epithelial tumors, and experimental models specific to these targets are highly desirable. Chimeric receptors were prepared by in-frame fusion of the CD8 extracellular sequence with the cytoplasmic sequences of RTKs. A CD8HER2 fusion protein was shown to form disulfide-mediated homodimers and to transform fibroblasts and epithelial cells. CD8RTK fusion proteins transform rat kidney epithelial cells and impart phenotypes that may reflect signaling specificity inherent in the native receptors. Transgenic expression of CD8HER2 and CD8Met in mice resulted in the formation of salivary and mammary gland tumors. The transgenic tumors allow the derivation of allograft tumors and cell lines that are sensitive to inhibition by small molecule kinase inhibitors. This approach provides excellent cell and tumor models for the characterization of signaling properties of diverse RTKs and for the evaluation of rationally designed antagonists targeting these kinases. [Mol Cancer Ther 2006;5(6):1571–6]
Implications of tissue transglutaminase expression in malignant melanoma
Authors: Fok Jansina Y. , Ekmekcioglu Suhendan , Mehta Kapil
Published: July 2006

Human malignant melanoma is a highly aggressive form of cancer; the 5-year survival rate in patients with stage III or IV disease is <5%. In patients with metastatic melanoma, systemic therapy becomes ineffective because of the high resistance of melanoma cells to various anticancer therapies. We have found previously that development of the drug resistance and metastatic phenotypes in breast cancer cells is associated with increased tissue transglutaminase (TG2) expression. In the study reported here, we investigated TG2 expression and its implications in metastatic melanoma. We found that metastatic melanoma cell lines expressed levels of TG2 up to 24-fold higher than levels in radial growth phase of primary melanoma cell lines. Activation of endogenous TG2 by the calcium ionophore A23187 induced a rapid and strong apoptotic response in A375 cells and A23187-induced apoptosis could be blocked by TG2-specific inhibitors. These findings indicated that activation of endogenous TG2 could serve as a strategy for inducing apoptosis in malignant melanomas. Importantly, tumor samples from patients with malignant melanomas showed strong expression of TG2, suggesting that TG2 expression is selectively up-regulated during advanced developmental stages of melanoma. We observed that 20% to 30% of TG2 protein was present on cell membranes in association with β1 and β5 integrins. This association of TG2 with cell surface integrins promoted strong attachment of A375 cells to fibronectin-coated surfaces, resulting in increased cell survival in serum-free medium. Inhibition of TG2 by small interfering RNA inhibited fibronectin-mediated cell attachment and cell survival functions in A375 cells. Overall, our results suggest that TG2 expression contributes to the development of chemoresistance in malignant melanoma cells by exploiting integrin-mediated cell survival signaling pathways. [Mol Cancer Ther 2006;5(6):1493–503]
Chemotherapy and chemosensitization of non–small cell lung cancer with a novel immunomodulatory oligonucleotide targeting Toll-like receptor 9
Authors: Wang Hui , Rayburn Elizabeth R. , Wang Wei , Kandimalla Ekambar R. , Agrawal Sudhir , Zhang Ruiwen
Published: July 2006

Lung cancer is a leading cause of death world-wide and the long-term survival rate for lung cancer patients is one of the lowest for any cancer. New therapies are urgently needed. The present study was designed to evaluate an immunomodulatory oligonucleotide as a novel type of therapy for lung cancer. The in vivo effects of the immunomodulatory oligonucleotides were determined in four tumor models derived from human non–small cell lung cancer (NSCLC) cell lines (A549, H1299, H358, and H520), administered alone or in combination with conventional chemotherapeutic agents used to treat lung cancer. The in vitro effects of the immunomodulatory oligonucleotide on the growth, apoptosis, and proliferation of NSCLC cells were also determined. We also examined NSCLC cells for expression of Toll-like receptor 9 (TLR9), the receptor for the immunomodulatory oligonucleotide. We showed several important findings: (a) treatment with the immunomodulatory oligonucleotide led to potent antitumor effects, inhibiting tumor growth by at least 60% in all four in vivo models; (b) combination with the immunomodulatory oligonucleotide led to enhanced effects following treatment with gemcitabine or Alimta; (c) the immunomodulatory oligonucleotide increased apoptosis, decreased proliferation, and decreased survival in A549 cells in vitro; and (d) both TLR9 mRNA and protein were expressed in NSCLC cells. The immunomodulatory oligonucleotide has potent antitumor effects as monotherapy and in combination with conventional chemotherapeutic agents, and may act directly on NSCLC cells via TLR9. The present study provides a rationale for developing the immunomodulatory oligonucleotide for lung cancer therapy. [Mol Cancer Ther 2006;5(6):1585–92]
A Quantitative Trait Loci-Specific Gene-by-Sex Interaction on Systolic Blood Pressure Among American Indians
Authors: Franceschini Nora , MacCluer Jean W. , Göring Harald H.H. , Cole Shelley A. , Rose Kathryn M. , Almasy Laura , Diego Vincent , Laston Sandra , Lee Elisa T. , Howard Barbara V. , Best Lyle G. , Fabsitz Richard R. , Roman Mary J. , North Kari E.
Published: July 2006

Age-adjusted systolic blood pressure is higher in males than females. Genetic factors may account for this sex-specific variation. To localize sex-specific quantitative trait loci (QTL) influencing blood pressure, we conducted a genome scan of systolic blood pressure, in males and females, separately and combined, and tested for aggregate and QTL-specific genotype-by-sex interaction in American Indian participants of the Strong Heart Family Study. Blood pressure was measured 3 times and the average of the last 2 measures was used for analyses. Systolic blood pressure was adjusted for age and antihypertensive treatment within study center. We performed variance component linkage analysis in the full sample and stratified by sex among 1168 females and 726 males. Marker allele frequencies were derived using maximum likelihood estimates based on all individuals, and multipoint identity-by-descent sharing was estimated using Loki. We detected suggestive evidence of a QTL influencing systolic blood pressure on chromosome 17 at 129 cM between markers D17S784 and D17S928 (logarithm of odds [LOD]=2.4). This signal substantially improved when accounting for QTL-specific genotype-by-sex interaction (
P
=0.04), because we observed an LOD score of 3.3 for systolic blood pressure in women on chromosome 17 at 136 cM. The magnitude of the linkage signal on chromosome 17q25.3 was slightly attenuated when participants taking antihypertensive medications were excluded, although suggestive evidence for linkage was still identified (LOD=2.8 in women). Accounting for interaction with sex improved our ability to detect QTLs and demonstrated the importance of considering genotype-by-sex interaction in our search for blood pressure genes.
Geometric Determinants of Functional Tricuspid Regurgitation
Authors: Ton-Nu Thanh-Thao , Levine Robert A. , Handschumacher Mark D. , Dorer David J. , Yosefy Chaim , Fan Dali , Hua Lanqi , Jiang Leng , Hung Judy
Published: July 2006

Background—

Tricuspid regurgitation (TR) is an important predictor of morbidity and mortality in heart failure. We aimed to examine the 3D geometry of the tricuspid valve annulus (TVA) in patients with functional TR, comparing them with patients with normal tricuspid valve function and relating annular geometric changes to functional TR.

Methods and Results—

TVA shape was examined by real-time 3D echocardiography in 75 patients: 35 with functional TR and 40 with normal tricuspid valve function (referent group). The 3D shape of the TVA was reconstructed from rotated 2D planes, and the annular plane was computed by least-squares fitting. Annular area and mediolateral, anteroposterior, and high (superior)-low (inferior) distances were calculated. TR was assessed by vena contracta width. The normal TVA has a bimodal pattern (high-low distance=7.23±1.05 mm). High points were located anteroposteriorly, and low points were located mediolaterally. With moderate or greater TR (vena contracta width 5.80±2.62 mm), the TVA became dilated (17.24±4.75 versus 9.83±2.18 cm
2
,
P
<0.0001, TR versus referent), more planar with decreased high-low distance (4.14±1.05 mm), and more circular with decreased ratio of mediolateral/anteroposterior (1.11±0.09 versus 1.32±0.09,
P
<0.0001, TR versus referent).

Conclusions—

The normal TVA has a bimodal shape with distinct high points located anteroposteriorly and low points located mediolaterally. With functional TR, the annulus becomes larger, more planar, and circular. These changes in annular shape with TR have potentially important mechanistic and therapeutic implications for tricuspid valve repair.