bluuebunny/crossref_metadata_2025 huggingface dataset:
A Divalent Hapten-Peptide Induces Apoptosis in Human Non–Hodgkin Lymphoma Cell Lines Targeted by Anti-CD20 × Anti-Hapten Bispecific Antibodies
Authors: Brard Pierre-Yves , Karacay Habibe , Stein Rhona , Sharkey Robert M. , Mattes M. Jules , Chang Chien-Hsing , Rossi Edmund A. , McBride William J. , Goldenberg David M.
Published: September 2007

Purpose: Bispecific antibody (bsMAb) pretargeting procedures use divalent hapten-peptides to stabilize the binding of the hapten-peptide on tumor cells by a process known as the affinity enhancement system. The goal of this study was to determine if a divalent hapten-peptide could induce apoptosis by cross-linking bsMAb bound to CD20.

Methods: Three forms of bsMAbs were prepared by coupling the IgG, F(ab′)2, or Fab′ of a humanized anti-CD20 antibody to a Fab′ of a murine antibody directed against the hapten histamine-succinyl-glycine (HSG). A recombinant bsMAb with divalent binding to CD20 and monovalent binding to HSG was also examined. Induction of apoptosis on SU-DHL-6, RL, and Ramos cells was examined by propidium iodide staining, caspase-3 activation, and mitochondrial membrane potential collapse, and compared with induction by cross-linking an anti-CD20 IgG with an antispecies antibody.

Results: The various forms of bsMAb had differing baseline levels of apoptosis in the absence of the divalent HSG peptide. The addition of the divalent HSG peptide significantly increased the level of apoptosis seen with the Fab′ × Fab′ bsMAb by 2.2- to 3.9-fold, as well as the F(ab′)2 × Fab′, IgG × Fab′, and the recombinant bsMAbs by ∼1.5-fold.

Conclusions: The addition of a divalent HSG peptide to various forms of bispecific anti-CD20 MAbs could enhance apoptotic signaling in several lymphoma cells. This effect was more consistently measured when the orientation of the anti–hapten-binding arm of the bsMAb was well defined, such as in the Fab′ × Fab′ and recombinant forms of bsMAb.
The Dock and Lock Method: A Novel Platform Technology for Building Multivalent, Multifunctional Structures of Defined Composition with Retained Bioactivity
Authors: Chang Chien-Hsing , Rossi Edmund A. , Goldenberg David M.
Published: September 2007

The idea, approach, and proof-of-concept of the dock and lock (DNL) method, which has the potential for making a large number of bioactive molecules with multivalency and multifunctionality, are reviewed. The key to the DNL method seems to be the judicious application of a pair of distinct protein domains that are involved in the natural association between protein kinase A (PKA; cyclic AMP–dependent protein kinase) and A-kinase anchoring proteins. In essence, the dimerization and docking domain found in the regulatory subunit of PKA and the anchoring domain of an interactive A-kinase anchoring protein are each attached to a biological entity, and the resulting derivatives, when combined, readily form a stably tethered complex of a defined composition that fully retains the functions of individual constituents. Initial validation of the DNL method was provided by the successful generation of several trivalent bispecific binding proteins, each consisting of two identical Fab fragments linked site-specifically to a different Fab. The integration of genetic engineering and conjugation chemistry achieved with the DNL method may not only enable the creation of novel human therapeutics but could also provide the promise and challenge for the construction of improved recombinant products over those currently commercialized, including cytokines, vaccines, and monoclonal antibodies.
Pretargeted Radioimmunotherapy for B-Cell Lymphomas
Authors: Green Damian J. , Pagel John M. , Pantelias Anastasia , Hedin Nathan , Lin Yukang , Wilbur D. Scott , Gopal Ajay , Hamlin Donald K. , Press Oliver W.
Published: September 2007

Relapsed or treatment refractory B-cell lymphomas are currently incurable with conventional chemotherapy and radiation treatments. High-dose chemoradiotherapy and stem cell transplantation can cure some patients with relapsed or refractory lymphoma, but the majority of such patients die of progressive disease. We have investigated the potential utility of pretargeted radioimmunotherapy using monoclonal antibody-streptavidin, immunoconjugates, and fusion proteins in combination with N-acetylgalactosamine dendrimeric clearing agent and radiometal-labeled 1,4,7,10-tetraazacyclododecane-N,N′,N″,N‴-tetraacetic acid biotin for treatment of lymphomas using mouse and primate models. We have targeted a variety of cell surface antigens, including CD20, CD22, CD45, and HLA-DR, using conventional and pretargeted radioimmunotherapy. These studies showed the marked superiority of pretargeted radioimmunotherapy for each of the antigenic targets in terms of superior biodistributions, more complete tumor regressions, and longer survival. We are optimistic that this novel approach will provide a meaningful prolongation of survival for patients with relapsed or refractory lymphomas.
Increased Sentinel Lymph Node Lymphangiogenesis is Associated with Nonsentinel Axillary Lymph Node Involvement in Breast Cancer Patients with a Positive Sentinel Node
Authors: Van den Eynden Gert G. , Vandenberghe Melanie K. , van Dam Pieter-Jan H. , Colpaert Cecile G. , van Dam Peter , Dirix Luc Y. , Vermeulen Peter B. , Van Marck Eric A.
Published: September 2007

Purpose: Lymph node (LN) lymphangiogenesis has recently been shown to be important in the premetastatic niche of sentinel LNs. To study its role in the further metastatic spread of human breast cancer, we investigated the association of angiogenesis and lymphangiogenesis in sentinel LN metastases with the presence of nonsentinel LN metastases in breast cancer patients with a positive sentinel LN.

Experimental Design: Angiogenesis and lymphangiogenesis—quantified as endothelial cell proliferation fraction (ECP%) and lymphatic ECP fraction (LECP%)—were assessed in sentinel LN metastases of 65 T1/T2 patients with breast cancer using CD34/Ki67 and D2-40/Ki67 immunohistochemical double stains. Correlations were analyzed between nonsentinel LN status, LECP%, and other clinicopathologic variables (number of involved sentinel LNs, size of the primary tumor and LN metastasis, presence of lymphovascular invasion in the primary tumor, and of extracapsular growth in the sentinel LN metastasis).

Results: Thirty seven out of 65 patients (56.9%) had at least one involved nonsentinel LN. Size of the sentinel LN metastasis (P = 0.001), lymphovascular invasion (P = 0.02), extracapsular growth (P = 0.02), and LECP% (P = 0.01) were correlated with a positive nonsentinel LN status. The multivariate logistic regression model retained high LECP% (odds ratios = 4.2, P = 0.01) and the presence of extracapsular growth (odds ratios = 3.38, P = 0.04) as independently associated with the presence of nonsentinel LN metastases.

Conclusions: Increased sentinel LN metastasis lymphangiogenesis is associated with metastatic involvement of nonsentinel axillary LNs. These are the first data sustaining the hypothesis that sentinel LN lymphangiogenesis is involved in further metastatic spread of human breast cancer.
Pathology Underrates Colon Cancer Extranodal and Nodal Metastases; Ex vivo Radioimmunodetection Helps Staging
Authors: Sézeur A. , Châtelet F.P. , Cywiner Ch. , de Labriolle-Vaylet Cl. , Chastang C. , Billotey Cl. , Malafosse M. , Gallot D. , Betton P. , Montravers F. , Carvajal-Gonzalez S. , Askienazy S. , Talbot J.N. , Rain J.D. , Milhaud G. , Saumon G. , Barbet J. , Gruaz-Guyon A.
Published: September 2007

Purpose: Colorectal carcinoma is frequently accompanied by small lymph nodes metastases that often escape pathologic examination. We evaluated whether ex vivo radioimmunodetection with the Affinity Enhancement System (AES) could improve detection of mesocolonic metastases.

Experimental Design: A bivalent 111In-labeled hapten was injected (16 patients) 4 days after a bispecific antibody (anticarcinoembryonic antigen, antihapten). Surgery was done 1 to 3 days later, and radioactive uptake in the mesocolon was recorded. Extensive pathologic examination of the mesocolon (reference method) was done after fat dissolution. This method visualizes all lymph nodes but is not in routine use.

Results: The reference method disclosed 705 nodes. There was no significant difference between the number of node metastases detected by AES or by the reference method (16 versus 17). Better detection would have been obtained by AES than by routine pathology (P < 0.01). In addition 12 extranodal metastases were found in this study of which eight were detected by AES. The prognostic importance of such extranodal metastases has been underlined in the literature. Routine pathology combined with AES would have disclosed all node metastases and 86% of total metastases versus 35% by routine pathology alone.

Conclusions: Ex vivo radioimmunodetection could improve nodal and extranodal metastases detection in patients with colorectal cancer. Its value for improving pathologic analysis, together with the effect of these small metastases on prognosis, should be further evaluated. The benefit of adjuvant chemotherapy for patients upstaged with radioimmunodection should also be assessed because adjuvant chemotherapy improves the 5-year survival of stage III patients.
Less Yin, More Yang: Confronting the Barriers to Cancer Immunotherapy
Authors: Lizée Gregory , Cantu Mayra A. , Hwu Patrick
Published: September 2007

Clinical trials involving T cell–based immunotherapy for the treatment of human cancer have shown limited degrees of success. In cancer vaccine trials conducted at multiple centers worldwide, immunization has often resulted in the robust elicitation of T cells that specifically recognize antigens expressed on the surface of tumor cells. However, to date, objective clinical responses resulting from these approaches have remained relatively rare. By contrast, adoptive transfer of laboratory-expanded T cells into patients has had more success, producing impressive clinical regressions in a subset of advanced metastatic melanoma patients. The failure of activated T cells to consistently induce clinical responses in many other patients has pushed us toward a deeper understanding of natural immunoregulatory mechanisms that are directly responsible for diminishing tumor-specific T-cell activation, migration, and effector function in vivo. Such immunosuppressive factors likely evolved to prevent autoimmunity, but are frequently co-opted by tumors to evade tumor-specific immune responses. With this knowledge, it now becomes imperative to develop specific clinical interventions capable of eliminating tumor-specific immunosuppression, with the goal of shifting the balance to favor effector T-cell function and tumor cell killing.
The farnesyltransferase inhibitor R115777 (tipifarnib) in combination with tamoxifen acts synergistically to inhibit MCF-7 breast cancer cell proliferation and cell cycle progressionin vitroandin vivo
Authors: Martin Lesley-Ann , Head Julia E. , Pancholi Sunil , Salter Janine , Quinn Emma , Detre Simone , Kaye Stan , Howes Angela , Dowsett Mitch , Johnston Stephen R.D.
Published: September 2007

Cross-talk between receptor tyrosine kinases and estrogen receptor is at least partly responsible for the development of acquired resistance to endocrine therapies. Hence, targeting receptor tyrosine kinases and their downstream partners with inhibitors/antagonists may reverse this resistance. Although ras mutations are rare in breast cancer (2%), aberrant function of Ras signal transduction pathways is common. We therefore investigated the efficacy of the farnesyltransferase inhibitor (FTI) R115777 (tipifarnib) in combination with tamoxifen in MCF-7 human breast cancer models both in vitro and in vivo. There was a synergistic antiproliferative interaction between R115777 and 4-hydroxy-tamoxifen in vitro as calculated by median effect analysis. The combination resulted in a significantly greater G1 arrest than either drug alone and this was associated with marked inhibition of cyclin D1 and induction of the cell cycle inhibitor p27kip1. Combining R115777 with either tamoxifen or estrogen withdrawal in vivo produced a significantly greater inhibition of tumor growth and lower xenograft cell proliferation than either therapy alone. These results suggest that the combination of this FTI with endocrine therapy may be of therapeutic benefit in the treatment of breast cancer. Enhanced G1 arrest due to modulation of cell cycle regulatory proteins may be the underlying mechanism for the positive interaction between FTIs and tamoxifen. [Mol Cancer Ther 2007;6(9):2458–67]
Effect of the histone deacetylase inhibitor LBH589 against epidermal growth factor receptor–dependent human lung cancer cells
Authors: Edwards Arthur , Li Jiannong , Atadja Peter , Bhalla Kapil , Haura Eric B.
Published: September 2007

Activating mutations in the epidermal growth factor receptor (EGFR) selectively activate signal transducers and activators of transcription (STAT) and Akt survival signaling pathways important in lung cancer cell growth and survival. Many kinases, such as EGFR, rely on heat shock protein 90 (Hsp90) chaperone function for conformational maturation and proper function. Histone deacetylase inhibitors (HDACi) have been suggested to regulate signaling protein interactions via modulation of protein chaperone function through Hsp90. For these reasons, we evaluated the effect of a HDACi in lung cancer cells with defined EGFR status. Cell lines with defined EGFR status and sensitivity to EGFR tyrosine kinase inhibitors were exposed to the HDACi LBH589, and the effects on cell survival, proliferation, and downstream signaling were evaluated. LBH589 resulted in increased acetylation of Hsp90 and reduced association of Hsp90 with EGFR, Akt, and STAT3. LBH589 selectively depleted proteins important in signaling cascades in cell lines harboring EGFR kinase mutations, such as EGFR, STAT3, and Akt, and these cells underwent apoptosis following exposure to LBH589. In addition, we found depletion of STAT3-dependent survival proteins, including Bcl-xL, Mcl-1, and Bcl-2. Conversely, LBH589 had little effect on apoptosis in cells not dependent on EGFR for survival, no changes were identified in the expression of EGFR or other survival proteins, and the predominant effect was cell cycle arrest rather than apoptosis. A 10-fold increase in LBH589 was necessary to observe durable depletion of EGFR and Akt in cells not harboring EGFR mutation. Treatment of cells with erlotinib and LBH589 resulted in synergistic effects on lung cancer cells dependent on EGFR for growth and/or survival. Based on these results, LBH589 can acetylate Hsp90, deplete EGFR and other key survival signaling proteins, and trigger apoptosis only in lung cancer cells harboring EGFR mutations. Therefore, EGFR mutation status may be predictive of outcome with LBH589 and possibly other HDACi. [Mol Cancer Ther 2007;6(9):2515–24]
Improved low molecular weight Myc-Max inhibitors
Authors: Wang Huabo , Hammoudeh Dalia I. , Follis Ariele Viacava , Reese Brian E. , Lazo John S. , Metallo Steven J. , Prochownik Edward V.
Published: September 2007

Compounds that selectively prevent or disrupt the association between the c-Myc oncoprotein and its obligate heterodimeric partner Max (Myc-Max compounds) have been identified previously by high-throughput screening of chemical libraries. Although these agents specifically inhibit the growth of c-Myc–expressing cells, their clinical applicability is limited by their low potency. We describe here several chemical modifications of one of these original compounds, 10058-F4, which result in significant improvements in efficacy. Compared with the parent structure, these analogues show enhanced growth inhibition of c-Myc–expressing cells in a manner that generally correlates with their ability to disrupt c-Myc-Max association and DNA binding. Furthermore, we show by use of a sensitive fluorescence polarization assay that both 10058-F4 and its active analogues bind specifically to monomeric c-Myc. These studies show that improved Myc-Max compounds can be generated by a directed approach involving deliberate modification of an index compound. They further show that the compounds specifically target c-Myc, which exists in a dynamic and relatively unstructured state with only partial and transient α-helical content. [Mol Cancer Ther 2007;6(9):2399–408]
AZD6244 and doxorubicin induce growth suppression and apoptosis in mouse models of hepatocellular carcinoma
Authors: Huynh Hung , Chow Pierce K.H. , Soo Khee-Chee
Published: September 2007

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide, with no effective treatment for most individuals who succumb to this neoplasm. We report that treatment of primary HCC cells with the mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase 1/2 inhibitor AZD6244 (ARRY-142886) plus doxorubicin led to synergistic growth inhibition and apoptosis. In vivo administration of AZD6244, doxorubicin, or the combination of AZD6244 and doxorubicin in mice bearing 5-1318 HCC xenografts resulted in approximately 52% ± 15%, 12% ± 9%, and 76% ± 7% growth inhibition, respectively. AZD6244-inhibited tumor growth was associated with increased apoptosis, inactivation of ERK1/2, inhibition of cell proliferation, and down-regulation of cell cycle regulators, including cyclin D1, cdc-2, cyclin-dependent kinases 2 and 4, cyclin B1, and c-Myc. The AZD6244-doxorubicin combined protocol not only promoted apoptosis but also induced a synergistic effect not seen in single-agent–treated tumors, including increased expression of the p130 RB tumor suppressor gene. Our study provides a strong rationale for clinical investigation of combination therapy with the mitogen-activated protein/ERK kinase 1/2 inhibitor AZD6244 and doxorubicin in patients with HCC. [Mol Cancer Ther 2007;6(9):2468–76]
Selenium inhibition of survivin expression by preventing Sp1 binding to its promoter
Authors: Chun Jae Yeon , Hu Yan , Pinder Elaine , Wu Jianguo , Li Fengzhi , Gao Allen C.
Published: September 2007

Survivin, an antiapoptotic protein highly expressed in cancer, regulates multiple cellular network associated with cancer cell viability and drug resistance. Inhibition of survivin expression has been pursued as a valid cancer therapeutic target. In this study, we showed that selenium, an effective chemopreventive agent for many types of cancers, down-regulated survivin expression. Selenium inhibited survivin expression in both mRNA and protein levels in a dose- and time-dependent manner. Using a series of survivin promoter–luciferase constructs, a 37-bp DNA element in the survivin core promoter region that mediates the ability of selenium to inhibit survivin transcription was identified. Gel mobility shift assays and chromatin immunoprecipitation analyses revealed that selenium prevents the binding of Sp1 or Sp1-like proteins to the 37-bp cis-acting DNA element in the survivin promoter. Furthermore, inhibition of survivin expression by small interfering RNA enhanced selenium's inhibitory effects on cell growth, whereas overexpression of survivin in LNCaP human prostate cancer cells desensitized cancer cells to selenium effect, suggesting that the expression of survivin plays an important role in determining the response of cancer cells to selenium. Taken together, these results suggest that selenium down-regulated survivin expression by preventing the binding of Sp1 or Sp1-like proteins to the promoter of survivin, which contributes at least in part to the inhibitory effect of selenium on survivin gene transcription. In addition, down-regulation of survivin expression may account for one of the molecular mechanisms of the anticancer effects of selenium. [Mol Cancer Ther 2007;6(9):2572–80]
The radiosensitization effect of parthenolide in prostate cancer cells is mediated by nuclear factor-κB inhibition and enhanced by the presence of PTEN
Authors: Sun Yulan , St. Clair Daret K. , Fang Fang , Warren Graham W. , Rangnekar Vivek M. , Crooks Peter A. , St. Clair William H.
Published: September 2007

Parthenolide has been shown to have anti-inflammatory and antitumor properties. However, whether and how parthenolide enhances tumor sensitivity to radiation therapy are unknown. In this study, we show that inhibition of the nuclear factor-κB (NF-κB) pathway is a common mechanism for the radiosensitization effect of parthenolide in prostate cancer cells LNCaP, DU145, and PC3. Parthenolide inhibits radiation-induced NF-κB DNA-binding activity and the expression of its downstream target sod2, the gene coding for an important antiapoptotic and antioxidant enzyme (manganese superoxide dismutase) in the three prostate cancer cells. Different susceptibilities to parthenolide's effect are observed in two radioresistant cancer cells, DU145 and PC3, with DU145 cells showing higher sensitivity. This differential susceptibility to parthenolide is due, in part, to the fact that in addition to NF-κB inhibition, parthenolide activates the phosphatidylinositol-3-kinase/Akt prosurvival pathway in both cell lines. However, the activated Akt in DU145 cells is kept at a relatively low level compared with that in PC3 cells due to the presence of functional PTEN. Transfection of wild-type PTEN into PTEN-null cells, PC3, confers the enhanced radiosensitization effect of parthenolide in PTEN-expressing cells. When PTEN expression is knocked down in DU145 cells, the cells become more resistant to parthenolide's effect. Taken together, these results suggest that parthenolide inhibits the NF-κB pathway and activates the phosphatidylinositol-3-kinase/Akt pathway in prostate cancer cells. The radiosensitization effect of parthenolide is due, in part, to the inhibition of the NF-κB pathway. The presence of PTEN enhances the radiosensitization effect of parthenolide, in part, by suppressing the absolute amount of activated p-Akt. [Mol Cancer Ther 2007;6(9):2477–86]
Histone deacetylase inhibitors selectively suppress expression of HDAC7
Authors: Dokmanovic Milos , Perez Gisela , Xu Weisheng , Ngo Lang , Clarke Cathy , Parmigiani Raphael B. , Marks Paul A.
Published: September 2007

There are 18 histone deacetylases (HDAC) generally divided into four classes based on homology to yeast HDACs. HDACs have many protein substrates in addition to histones that are involved in regulation of gene expression, cell proliferation, and cell death. Inhibition of HDACs can cause accumulation of acetylated forms of these proteins, thus altering their function. HDAC inhibitors (HDACi), such as the hydroxamic acid–based vorinostat (suberoylanilide hydroxamic acid), inhibit the zinc-containing classes I, II, and IV, but not the NAD+-dependent class III, enzymes. HDACis are a group of novel anticancer agents. Vorinostat is the first HDACi approved for clinical use in the treatment of the cancer cutaneous T-cell lymphoma. Factors affecting expression of HDACs are not well understood. This study focuses on the effect of the HDACi vorinostat on the expression of class I and class II HDACs. We found that vorinostat selectively down-regulates HDAC7 with little or no effect on the expression of other class I or class II HDACs. Fourteen cell lines were examined, including normal, immortalized, genetically transformed, and human cancer-derived cell lines. Down-regulation of HDAC7 by vorinostat is more pronounced in transformed cells sensitive to inhibitor-induced cell death than in normal cells or cancer cells resistant to induced cell death. Modulation of HDAC7 levels by small interfering RNA–mediated knockdown or by HDAC7 overexpression is associated with growth arrest but without detectable changes in acetylation of histones or p21 gene expression. Selective down-regulation of HDAC7 protein may serve as a marker of response of tumors to HDACi. [Mol Cancer Ther 2007;6(9):2525–34]
Hypoxia modulation and radiosensitization by the novel dual EGFR and VEGFR inhibitor AEE788 in spontaneous and related allograft tumor models
Authors: Oehler-Jänne Christoph , Jochum Wolfram , Riesterer Oliver , Broggini-Tenzer Angela , Caravatti Giorgio , Vuong Van , Pruschy Martin
Published: September 2007

Concomitant inhibition of ErbB1/2- and VEGF receptor-signaling synergizes when used in combination with DNA-damaging agents. Here, we investigated for the first time the combined treatment modality of the novel dual specific receptor tyrosine kinase inhibitor AEE788 with ionizing radiation and analyzed treatment-induced end points in situ as indicators for a potential sensitizing mechanism. Furthermore, we assessed tumor hypoxia in response to different antiangiogenic and antiproliferative treatment modalities. The combined treatment effect was investigated in a spontaneously growing mammary carcinoma model and against Her-2/neu-overexpressing mammary carcinoma allografts. In tumor allografts derived from murine mammary carcinoma cells of mouse mammary tumor virus/c-neu transgenic mice, a minimal treatment regimen with AEE788 and fractionated irradiation resulted in an at least additive tumor response. Treatment response in the corresponding spontaneous tumor model strongly exceeded the response induced in the isogenic allografts. Treatment-induced changes of tumor proliferation, apoptosis, and microvessel density were similar in the two tumor models. Treatment with AEE788 alone or in combination with IR strongly improved tumor oxygenation in both tumor models as determined by the detection of endogenous and exogenous markers of tumor hypoxia. Specific inhibition of the VEGF-receptor tyrosine kinase versus Erb1/2-receptor tyrosine kinase indicated that it is the antiproliferative and not the antiangiogenic potency of AEE788 that mediates the hypoxia-reducing effect of this dual kinase-specific inhibitor. Overall, we show that concomitant inhibition of ErbB- and VEGF-receptor signaling by AEE788, in combination with ionizing radiation, is a promising treatment approach, especially in hypoxic, oncogenic ErbB-driven tumors. [Mol Cancer Ther 2007;6(9):2496–504]
Activation of the Mitogen-Activated Protein Kinases and Akt in Response to Pulmonary Artery Banding in the Fetal Sheep Heart Is Developmentally Regulated
Authors: Olson Aaron K. , Protheroe Kristen N. , Scholz Thomas D. , Segar Jeffrey L.
Published: September 2007

Background: The postnatal heart responds to biomechanical stress with hypertrophy. The fetal heart may also undergo hyperplasia, but the percentage of mitotically active cardiomyocytes decreases throughout gestation. The signaling pathways controlling growth and proliferation in the fetal heart are poorly understood. Objective: To determine whether activation of the mitogen-activated protein kinases and Akt in the acute response to pressure loading in the fetal heart is developmentally regulated. Methods: Pulmonary artery banding (PAB) was performed in 100- or 128-day fetuses of twin gestation (n = 6 per group) for 6 h. One twin served as a control. Right ventricular (RV) and left ventricular (LV) mitogen-activated protein kinase, Akt, and cyclin D1 protein levels were determined by Western blot. Results: Within each gestational age group, hemodynamic and arterial blood gas values were similar between PAB and control fetuses. The total mitogen-activated protein kinase and Akt protein levels were unchanged by PAB at both gestational ages, as were active p38 and JNK levels. The RV levels of active ERK tended to decrease in 128-day PAB fetuses as compared with controls, and LV active ERK normalized to total ERK was significantly decreased. At gestational age (GA) 100 days, RV active ERK levels were significantly higher in PAB animals as compared with controls, with a trend towards increased active Akt levels. No differences were seen in the 100-day LV. The levels of the cell cycle promoter cyclin D1 were unchanged in all animals. Conclusions: Pressure loading of the fetal sheep heart leads to developmentally regulated cell signaling profiles. ERK and possibly Akt may be important regulators of in vivo cardiomyocyte hyperplasia.
Effects of Bariatric Surgery on Early Myocardial Alterations in Adult Severely Obese Subjects
Authors: Di Bello Vitantonio , Santini Ferruccio , Di Cori Andrea , Pucci Andrea , Talini Enrica , Palagi Caterina , Delle Donne Maria Grazia , Marsili Alessandro , Fierabracci Paola , Valeriano Rocco , Scartabelli Giovanna , Giannetti Monica , Anselmino Marco , Pinchera Aldo , Mariani Mario
Published: September 2007

Objective: Aim of this study was to investigate the effect of weight loss on structural and functional myocardial alterations in severely obese subjects treated with bariatric surgery. Patients and Methods: Thirteen severely obese patients (2 males and 11 females) were enrolled in the study. All subjects underwent conventional 2D color Doppler echocardiography. The new ultrasonic techniques used were: (a) integrated backscatter for the analysis of myocardial reflectivity, referred to pericardial interface as expression of myocardial structure (increase in collagen content) and of cyclic variation index as expression of intrinsic myocardial contractility and (b) color Doppler myocardial imaging (CDMI) for the analysis of strain and strain rate (myocardial deformability). All subjects underwent bariatric surgery and were resubmitted to echocardiographic and biochemical examination 6–24 months after surgery. Results: The main finding of the present study was a quite complete normalization of myocardial functional and structural alterations after weight loss. In particular, the cyclic variation index at septum level improved from 14.6 ± 7.0 before to 25.7 ± 11.2 (means ± SD) after surgery (controls: 36.2 ± 9.1). Mean reflectivity at septum level significantly decreased from 55.8 ± 9.5 to 46.5 ± 8.8 (controls: 43.0 ± 8.0). Also, the strain at septum level significantly improved after surgery (from –11.9 ± 3.2 to –20.4 ± 5.3; controls: –23.4 ± 9). Conclusion: This study establishes: (a) the utility of new ultrasonic techniques to detect very early structural and functional myocardial alterations in severely obese patients, and (b) the regression of these subclinical abnormalities after weight loss achieved by bariatric surgery.
Litigation in Nontraumatic Aortic Diseases – A Tempest in the Malpractice Maelstrom
Authors: Elefteriades John A. , Barrett Peter W. , Kopf Gary S.
Published: September 2007

Objectives: Physicians are vulnerable to highly litigated thoracic aortic diseases. On the basis of a review of litigated cases, we aim to determine legally protective strategies for physicians and methods to improve treatment. Methods: Thirty-three nontraumatic, thoracic aorta-related legal cases were analyzed. Results: Twenty-three patients (69.7%) had dissections (21 ascending, 2 descending), 8 (24.2%) had aneurysms and 2 had miscellaneous other phenomena (1 coarctation and 1 iatrogenic descending aortic rupture). The adverse event was death in 30 (90.9%) patients and paraplegia or stroke in 3 (9.1%). Allegations included: failure/delay in diagnosis (19), delay in surgery (4), error in surgical technique (5), failure to prevent paraplegia (2) and miscellaneous (3). Medical treatment was retrospectively judged suboptimal in 22 cases (66.6%) for reasons consonant with allegations. Conclusions: Aortic disease can be diagnostically elusive, as ‘the great masquerader’. Emergency physicians must maintain a high index of suspicion for aneurysm and dissection. The D-dimer test can effectively rule out aortic dissection. ‘Triple rule-out’ CT scans should be performed liberally. CT scan readers must remember to evaluate the aorta. Operating room administrators must be aware that postponing a scheduled thoracic aortic case may result in interim rupture and consequent litigation. With virulent thoracic aortic diseases, adverse outcome itself does not imply substandard care.
Clinical and Hemodynamic Effects of Bosentan Dose Optimization in Symptomatic Heart Failure Patients with Severe Systolic Dysfunction, Associated with Secondary Pulmonary Hypertension – A Multi-Center Randomized Study
Authors: Kaluski Edo , Cotter Gad , Leitman Marina , Milo-Cotter Olga , Krakover Ricardo , Kobrin Isaac , Moriconi Tina , Rainisio Maurizio , Caspi Avraham , Reizin Leonardo , Zimlichman Reuven , Vered Zvi
Published: September 2007

Objective: Toevaluate the effects of bosentan on echo-derived hemodynamic measurements, and clinical variables in symptomatic heart failure (HF) patients. Method: Multi- center, double-blind, randomized (2:1), placebo-controlled study comparing bosentan (8–125 mg b.i.d.) to placebo in patients with New York Heart Association class IIIb–IV HF, left ventricular ejection fraction <35% and systolic pulmonary artery pressure (SPAP) >40 mm Hg. Primary and secondary endpoints were change from baseline to 20 weeks in SPAP and cardiac index, respectively. Safety endpoints were treatment emergent adverse events (AEs), change in body weight, hemoglobin, hematocrit, systolic blood pressure and diuretic use. Results: Ninety-four patients enrolled: 60 to bosentan, 34 to placebo. There was no significant difference between the 2 arms in SPAP change (0.1 ± 11.5 mm Hg , 95% confidence limit (CL) –5.4 to 5.2, p = 0.97), cardiac index shift (0.12 ± 0.45, 95% CL –0.09 to 0.33 , p = 0.24 ) or any of the other 22 echocardigraphic measurements obtained. Therapy-duration was longer in the placebo arm, while more patients in the bosentan arm experienced adverse and serious AEs. Conclusion: In HF patients with left ventricular dysfunction and secondary pulmonary hypertension, bosentan did not provide any measurable hemodynamic benefit, and was associated with more frequent AEs, requiring drug discontinuation.
Exaggerated Beat-to-Beat R Amplitude Variability in Patients with Panic Disorder after Intravenous Isoproterenol
Authors: Yeragani Vikram K. , Pohl Robert , Bär Karl-Jürgen , Chokka Pratap , Tancer Manuel
Published: September 2007

Background: Anxiety symptoms are associated with a marked increase in sudden cardiac death, suggesting an abnormality in cardiac autonomic function. Our previous studies show a relationship between R amplitude variability and sympathetic function.Methods:We examined the effects of β-adrenergic stimulation on R and T amplitude variability in panic disorder patients by infusing the β-adrenergic agonist isoproterenol in 6 panic disorder patients and 11 normal subjects. The ECG signal was analyzed before the infusion and 5 min after the infusion was started. The outcome measures were the R and T detrended variance normalized for mean amplitudes (Rvm and Tvm) and the Rvi and Tvi, measures which are normalized for the inter-beat interval variability in addition. Results: Patients with panic disorder had significantly more variability in R and T amplitude than normal controls and the R amplitude variability was increased further by β-adrenergic stimulation with isoproterenol, which was more pronounced in the patients. Conclusions: The isoproterenol-associated increase in R amplitude variability occurred in controls in the absence of significant anxiety. However, the increase in R amplitude variability was greater in patients with panic disorder, suggesting a greater sensitivity to β-adrenergic effects of isoproterenol or to isoproterenol-induced anxiety.
Interferon-α Influences Tryptophan Metabolism without Inducing Psychiatric Side Effects
Authors: Bannink Marjolein , Fekkes Durk , Van Gool Arthur R. , Kruit Wim H.J. , Sleijfer Stefan , van der Holt Bronno , Eggermont Alexander M.M. , Stoter Gerrit , Hengeveld Michiel W.
Published: September 2007

Background: Interferon-α (IFN-α) treatment is often associated with psychiatric side effects and has been found to lower the amount of tryptophan (TRP) available to the brain. The alterations in tryptophan metabolism might underlie the psychiatric side effects during treatment with IFN-α. Methods: In this study, 43 oncology patients treated with IFN-α were included. In order to study de novo depressions, depressed patients at baseline were excluded. Psychiatric evaluation comprising clinical judgment combined with a structured psychiatric interview and observer-based and self-report rating scales was performed at baseline and at 4 weeks, 8 weeks and 6 months after the start of treatment with IFN-α, and in the case of emerging psychopathology. Blood samples were drawn at the same evaluation times and assessed for concentrations of TRP, large neutral amino acids, kynurenine, 5-hydroxyindole acetic acid, neopterin and biopterin. Results: During treatment with IFN-α, several alterations in laboratory parameters occurred that were consistent with an increased degradation of peripheral TRP. Psychometric ratings revealed hardly any psychiatric changes. No consistent associations were found between changes in the laboratory assessments determined and the diverse psychiatric measures. Conclusion: In this study, IFN-α was found to alter TRP metabolism without inducing psychiatric side effects. Therefore, a possible relationship between TRP metabolism and depression was not substantiated by this study.
The Complexity of Management of Pregnancy-Associated Malignant Soft Tissue and Bone Tumors
Authors: Bernstein Molho Rinat , Kollender Yehuda , Issakov Josephine , Bickels Jacob , Flusser Gideon , Azem Fuad , Alon Adele , Inbar Moshe J. , Meller Isaac , Merimsky Ofer
Published: September 2007

Objective: The incidence of musculoskeletal tumors during pregnancy is very low. The aim of this study was to summarize our experience in treating a large cohort of pregnant patients diagnosed with these rare tumors. Methods: Women diagnosed with musculoskeletal tumors during pregnancy or immediately after delivery were identified retrospectively in our database between 1996 and 2006. Relevant maternal and neonatal data were collected. Results: Twenty patients, 8 with bone sarcomas (BS) and 12 with soft tissue sarcomas (STS) were identified. Two women were treated by wide excision of mass during pregnancy. In all other cases oncological treatment was delayed until delivery or termination of pregnancy. Vaginal delivery was possible in 9 patients, cesarean section was performed in 7, spontaneous abortion occurred in 1, and 3 underwent termination of pregnancy. Three newborns were premature, but normal growth and development were observed. Different techniques of fertility preservation were used in our patients. Five patients with BS and 5 patients with STS received preoperative chemotherapy, with different grades of toxicity. The degree of tumor necrosis tended to correlate with dose-intensity of chemotherapy. Seven patients with BS received adjuvant chemotherapy. Two patients with STS received adjuvant chemotherapy, two – radiotherapy, and four – both modalities. Median disease-free survival was 15.1 months, median overall survival – 25.4 months. Conclusions: Musculoskeletal tumors diagnosed during pregnancy, or after delivery, do not appear to have a significant impact on the prognosis. A multidisciplinary team should tailor the oncological approach individually.
Perinatal Changes of Plasma Resistin Concentrations in Pregnancies with Normal and Restricted Fetal Growth
Authors: Briana Despina D. , Boutsikou Maria , Baka Stavroula , Gourgiotis Demetrios , Marmarinos Antonios , Hassiakos Demetrios , Malamitsi-Puchner Ariadne
Published: September 2007

Background:The adipocytokine resistin inhibits adipogenesis and induces insulin resistance. Intrauterine growth-restricted (IUGR) neonates have reduced fat mass and changes of endocrine/metabolic mechanisms, predisposing to insulin resistance and metabolic syndrome in adult life. Objectives: To investigate plasma resistin concentrations in maternal, fetal and neonatal samples from IUGR and appropriate-for-gestational-age (AGA) pregnancies and correlate them with respective insulin concentrations. Methods: Plasma resistin and insulin concentrations were determined in 40 mothers and their 20 IUGR and 20 AGA singleton full-term fetuses and neonates on postnatal day 1 (N1) and day 4 (N4). Results: No significant differences in resistin concentrations were observed between AGA and IUGR groups. In the AGA group, maternal resistin concentrations were significantly lower compared to fetal, N1 and N4 ones (p = 0.003, p = 0.017 and p = 0.039, respectively). Maternal resistin concentrations positively correlated with fetal ones (r = 0.527, p = 0.02). In the IUGR group, maternal resistin concentrations were significantly lower compared to N1 (p < 0.001) and positively correlated with N4 concentrations (r = 0.626, p = 0.007). In both groups, the effect of gender, mode of delivery, parity and adjusted birth weight (customized centiles) on resistin concentrations was not significant. No correlation between resistin and insulin concentrations was documented. Conclusions: Lack of difference in resistin concentrations between IUGR and AGA groups, and lack of correlation between resistin and insulin concentrations as well as customized centiles, possibly suggests that resistin may not be directly involved in the regulation of insulin sensitivity and adipogenesis in the perinatal period. Mode of delivery and parity are not associated with circulating resistin concentrations.
Comparison of Different Techniques for Stereotactic Positron Emission Tomography Imaging
Authors: Novotny, Jr. Josef , Nechvil Karel , Ptacek Jaroslav , Novotny Josef , Liscak Roman
Published: September 2007

Background and Purpose: The aim of this study was to evaluate three different techniques used for stereotactic positron emission tomography (PET) image definition: (1) PET imaging with external stereotactic radioactive markers, (2) PET imaging without external stereotactic markers and subsequent coregistration with stereotactically defined imaging modality such as computed tomography (CT) or magnetic resonance imaging (MRI), (3) PET/CT imaging with utilization of external nonradioactive markers. Materials and Methods:Special head phantom that could be fixed in the Leksell stereotactic frame was used. The phantom was filled with fluorodeoxyglucose (18F-FDG) in water solution at an activity concentration of 17.5 kBq/ml simulating counts from standard brain. A spherically shaped glass test vessel (inner diameter 46 mm and wall thickness 3 mm) positioned in the head phantom was filled with FDG water solution at an activity concentration of 52.5 kBq/ml corresponding to pathologic lesion during PET imaging. Leksell stereotactic MRI indicator box was filled with FDG water solution at an activity concentration of 3.1 MBq/ml. The phantom was then stereotactically investigated on PET, PET/CT, CT and MRI. Deviations between stereotactic X, Y, Z PET coordinates of the center of the spherical vessel (simulating pathological lesion) were determined in the treatment planning system according to reference image and represented inaccuracy in stereotactic PET image definition for each of three tested methods of stereotactic PET definition. Results:Total spatial inaccuracy for stereotactic PET image definition based on radioactive fiducials was 1.7 and 0.7 mm for 3.4- and 2.0-mm PET slices, respectively. Total spatial PET image definition inaccuracy based on PET/CT imaging and stereotactic definition using nonradioactive CT fiducials was 0.7 mm. Total spatial PET image definition inaccuracy based on coregistration was 0.5 and 0.9 mm for coregistration with MRI and CT, respectively. Conclusion: All three evaluated stereotactic PET image definition techniques indicated very good accuracy in this phantom study entirely accepted by clinical requirements for functional imaging. The most convenient stereotactic PET image definition technique seemed to be PET image coregistration either on CT or MRI. In this situation, PET imaging can be done independently on frame application (for example few days before stereotactic frame application or even in a different centre) and then coregistered with stereotactically performed CT or MRI during the stereotactic procedure. However, detailed patient study has to be performed to test image coregistration inaccuracy on real clinical data.
Brain Shift during Deep Brain Stimulation Surgery for Parkinson’s Disease
Authors: Halpern Casey H. , Danish Shabbar F. , Baltuch Gordon H. , Jaggi Jurg L.
Published: September 2007

Background: Brain shift may occur during deep brain stimulation (DBS) surgery, which may affect the position of subcortical structures, compromising target localization. Methods: We retrospectively evaluated pre- and postoperative magnetic resonance imaging in 50 Parkinson’s disease patients who underwent bilateral subthalamic nucleus (STN) DBS. Patients were separated into two groups: group A – those with <2 mm cortical displacement (66 leads) and group B – those with ≧2 mm cortical displacement (34 leads). Pre and post-op coordinates of anterior (AC) and posterior commissures (PC), as well as the boundaries of red nucleus (RN) were compared. Results: AC-PC shortening due to posterior displacement of AC correlated with cortical displacement (p < 0.02) and was significantly greater in group B (0.41 ± 0.68 mm) than A (0.04 ± 0.76 mm; p < 0.005). Posterior shift of AC and RN’s center positively correlated (p < 0.0001). Shift appeared to impact the number of microelectrode tracks made to optimize STN targeting. AC-PC shortening also correlated with age (p < 0.003) and duration of surgery (p < 0.04). Conclusions: Subcortical structures shift during DBS surgery. This shift appears to be gravity-dependent since structures only shifted posteriorly, and patients were primarily in the supine position. Posterior shift of RN may indicate STN displacement. Such positional change may compromise target localization, requiring multiple microelectrode adjustments. This may provide indirect justification for the necessity of microelectrode recordings during DBS surgery.
Somatic Variation in Living, Wild Ring-Tailed Lemurs (Lemur catta)
Authors: Sauther Michelle L. , Cuozzo Frank P.
Published: September 2007

While understanding somatic variability among wild primates can provide insight into natural patterns of developmental plasticity, published data for living populations are rare. Here we provide such information for two distinct wild populations ofLemur catta.Variants observed include microtia, athelia, and female virilization. Dental variants observed include individuals with supernumerary teeth, rotated teeth, maxillary incisor agenesis, and severe malocclusion. There was a sex bias in incisor agenesis, with 5 of 7 examples (71%) found in males. The frequency of dental variants in our sample is lower than that seen in many other lemuriformes, as well as other primates. This may be a product of their less derived dental formula and/or their relatively fast dental development. Amassing such data is a critical first step to assess if wild primate populations are exhibiting normal variability or are being affected by potential inbreeding and/or environmental effects.