bluuebunny/crossref_metadata_2025 huggingface dataset:
HER2 Testing by Local, Central, and Reference Laboratories in Specimens From the North Central Cancer Treatment Group N9831 Intergroup Adjuvant Trial
Authors: Perez Edith A. , Suman Vera J. , Davidson Nancy E. , Martino Silvana , Kaufman Peter A. , Lingle Wilma L. , Flynn Patrick J. , Ingle James N. , Visscher Daniel , Jenkins Robert B.
Published: June 2006

Purpose

To evaluate concordance between local and central laboratory HER2 testing results in patients from the North Central Cancer Treatment Group (NCCTG) N9831 adjuvant trial of trastuzumab.

Patients and Methods

NCCTG N9831 is a randomized, phase III clinical trial comparing three drug regimens: doxorubicin/cyclophosphamide followed by paclitaxel with trastuzumab added concurrently, sequentially, or not at all as adjuvant therapy for women with HER2-positive resected breast cancer. Originally, patients were eligible if their tumors were HER2 positive by either local laboratory immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH). A protocol modification in 2002 made central laboratory testing mandatory, with additional testing of discordant cases conducted by a reference laboratory. Concordance between local and central laboratory, and level of agreement between central and reference laboratory HER2 findings in discordant cases were examined.

Results

HER2 positivity was confirmed in 85.8% of 2,535 patients registered since March 2002. When local and central evaluation used the same methodology, concordance was 88.1% for FISH and 81.6% for a diagnostic test for presence of the HER2 protein. Among discordant cases examined at the reference laboratory, there was 94.3% agreement for IHC (0, 1+, 2+) and 95.2% agreement for FISH (not gene amplified).

Conclusion

There was a high degree of discordance between local and central testing for IHC and FISH, but a high degree of agreement between central and reference laboratories. These findings support the importance of using high-volume, experienced laboratories for HER2 testing to improve the process of selecting patients likely to benefit from trastuzumab therapy.
Molecular Load of Pathologically Occult Metastases in Pelvic Lymph Nodes Is an Independent Prognostic Marker of Biochemical Failure After Localized Prostate Cancer Treatment
Authors: Ferrari Anna C. , Stone Nelson N. , Kurek Ralf , Mulligan Elizabeth , McGregor Roy , Stock Richard , Unger Pamela , Tunn Ulf , Kaisary Amir , Droller Michael , Hall Simon , Renneberg Heiner , Livak Kenneth J. , Gallagher Robert E. , Mandeli John
Published: June 2006

Purpose

Thirty percent of patients treated with curative intent for localized prostate cancer (PC) experience biochemical recurrence (BCR) with rising serum prostate-specific antigen (sPSA), and of these, approximately 50% succumb to progressive disease. More discriminatory staging procedures are needed to identify occult micrometastases that spawn BCR.

Patients and Methods

PSA mRNA copies in pathologically normal pelvic lymph nodes (N0-PLN) from 341 localized PC patients were quantified by real-time reverse-transcriptase polymerase chain reaction. Based on comparisons with normal lymph nodes and PLN with metastases and on normalization to 5 × 106 glyceraldehyde-3′-phosphate dehydrogenase mRNA copies, normalized PSA copies (PSA-N) and a threshold of PSA-N 100 or more were selected for continuous and categorical multivariate analyses of biochemical failure-free survival (BFFS) compared with established risk factors.

Results

At median follow-up of 4 years, the BFFS of patients with PSA-N 100 or more versus PSA-N less than 100 was 55% and 77% (P = .0002), respectively. The effect was greatest for sPSA greater than 20 ng/mL, 25% versus 60% (P = .014), Gleason score 8 or higher, 21% versus 66% (P = .0002), stage T3c, 18% versus 64% (P = .001), and high-risk group (50% v 72%; P = .05). By continuous analysis PSA-N was an independent prognostic marker for BCR (P = .049) with a hazard ratio of 1.25 (95% CI, 1.001 to 1.57). By categorical analysis, PSA-N 100 or more was an independent variable (P = .021) with a relative risk of 1.98 (95% CI, 1.11 to 3.55) for BCR compared with PSA-N less than 100.

Conclusion

PSA-N 100 or more is a new, independent molecular staging criterion for localized PC that identifies high-risk group patients with clinically relevant occult micrometastases in N0-PLN, who may benefit from additional therapy to prevent BCR.
Phase II Multicenter Study of Neoadjuvant Biochemotherapy for Patients With Stage III Malignant Melanoma
Authors: Lewis Karl D. , Robinson William A. , McCarter Martin , Pearlman Nathan , O'Day Steven J. , Anderson Clay , Amatruda Thomas T. , Baron Anna , Zeng Chan , Becker Maude , Dollarhide Susan , Matijevich Karen , Gonzalez Rene
Published: June 2006

Purpose

To determine the relapse-free survival, overall survival, and response rate of patients with stage III melanoma treated with neoadjuvant biochemotherapy in a multicenter setting.

Patients and Methods

Patients with pathologically proven stage III melanoma, either via clinical detection or sentinel lymph node positivity, were eligible for enrollment. Patients received two cycles of preoperative biochemotherapy followed by complete regional lymphadenectomy and two postoperative courses of biochemotherapy. The biochemotherapy regimen consisted of the following: cisplatin 20 mg/m2 on days 1 to 4, dacarbazine 800 mg/m2 on day 1 only, vinblastine 1.6 mg/m2 on days 1 to 4, interleukin-2 total dose of 36 MU/m2 during 4 days, and interferon alfa 5 MU/m2 on days 1 to 5. Growth factor support was administered with each cycle.

Results

Ninety-two patients were eligible for the study. At a median follow-up of 40.4 months, relapse-free survival and overall survival are 64% and 78%, respectively. There was a lower relapse rate and improved survival for patients with a positive sentinel lymph node compared with patients with clinically detected lymph nodes, although this difference did not reach statistical significance. Of the 50 patients with measurable disease, the overall response rate was 26%. Toxicity of the biochemotherapy was high but generally manageable.

Conclusion

The current study has expanded the preliminary evidence on neoadjuvant biochemotherapy for stage III melanoma.
Progression-Free Survival Rate As Primary End Point for Phase II Cancer Clinical Trials: Application to Mesothelioma—The EORTC Lung Cancer Group
Authors: Francart Julie , Legrand Catherine , Sylvester Richard , Van Glabbeke Martine , van Meerbeeck Jan P. , Robert Annie
Published: June 2006

Purpose

Phase II cancer clinical trials play a key role in the development of new drugs. These trials should be designed to accurately determine if the drug should be abandoned or if it is sufficiently promising for further investigation in phase III trials. With new cytostatic agents or when the response assessment is difficult, using the progression-free survival rate (PFSR) at a fixed time point, such as 3, 4, 5, or 6 months, instead of the response rate (RR) as the primary end point is an alternative approach. To design future phase II trials, reference values for PFSRs that correspond to drugs with insufficient (P0) and sufficient (P1) clinical activity (CA) are necessary. This article provides these values in mesothelioma.

Materials and Methods

The European Organisation for Research and Treatment of Cancer database registered ten closed mesothelioma trials (nine phase II trials and one phase III trial) with 523 total patients. Trials were grouped into three categories according to the published RR: significant (n = 259), moderate (n = 142), and insufficient (n = 122) CA.

Results

The PFSRs at 3, 4, 5, and 6 months, respectively, were as follows: 72%, 67%, 51%, and 43% in the group with significant CA; 59%, 51%, 42%, and 35% with moderate CA; and 52%, 40%, 34%, and 28% with insufficient CA.

Conclusion

These values may be used to define relevant P0 and P1 values in future phase II mesothelioma trials that use PFSR as the primary end point.
Phase II Study of Erlotinib in Patients With Advanced Biliary Cancer
Authors: Philip Philip A. , Mahoney Michelle R. , Allmer Cristine , Thomas James , Pitot Henry C. , Kim George , Donehower Ross C. , Fitch Tom , Picus Joel , Erlichman Charles
Published: June 2006

Purpose

Epidermal growth factor receptor/human epidermal growth factor receptor 1 and ligand expression is common in biliary cancers (BILI) and may be associated with worse outcome. The primary objective of this study was to determine the proportion of patients with advanced BILI who were progression-free at 6 months.

Methods

Patients with either unresectable or metastatic disease were studied. Only one prior systemic or locoregional therapy was allowed. Erlotinib was administered continuously at a dose of 150 mg per day orally.

Results

Forty-two patients with BILI were enrolled. The median age was 67 years (range, 33 to 82 years). Fifty-two percent of patients had Eastern Cooperative Oncology Group performance status of 1. Fifty-seven percent of patients had received prior chemotherapy for advanced BILI. HER1/EGFR expression by immunohistochemistry in tumor cells was detected in 29 (81%) of the 36 assessable patients. Seven of the patients (17%; 95% CI, 7% to 31%) were progression free at 6 months. Three patients had partial response by Response Evaluation Criteria in Solid Tumors Group classification of duration 4, 4, and 14 months, respectively. All responding patients had mild (grade 1/2) skin rash and two patients had positive tumoral HER1/EGFR expression. Three patients (7%) had toxicity-related dose reductions of erlotinib due to grade 2/3 skin rash.

Conclusion

Results suggest a therapeutic benefit for EGFR blockade with erlotinib in patients with biliary cancer. Additional studies with erlotinib as a single agent and in combination with other targeted agents are warranted in this disease.
The Role of UGT1A1*28 Polymorphism in the Pharmacodynamics and Pharmacokinetics of Irinotecan in Patients With Metastatic Colorectal Cancer
Authors: Toffoli Giuseppe , Cecchin Erika , Corona Giuseppe , Russo Antonio , Buonadonna Angela , D'Andrea Mario , Pasetto Lara Maria , Pessa Sergio , Errante Domenico , De Pangher Vincenzo , Giusto Mauro , Medici Michele , Gaion Fernando , Sandri Paolo , Galligioni Enzo , Bonura Salvatore , Boccalon Massimo , Biason Paola , Frustaci Sergio
Published: June 2006

Purpose

UGT1A1*28 polymorphism has been associated with decreased glucuronidation of SN38, the active metabolite of irinotecan. This could increase toxicity with this agent.

Patients and Methods

In a prospective study, 250 metastatic colorectal cancer patients were treated with irinotecan, fluorouracil, and leucovorin as first-line treatment. UGT1A1*28 polymorphism was investigated with respect to the distribution of hematologic and nonhematologic toxicity, objective response rate, and survival. Pharmacokinetics was investigated in a subgroup of patients (71 of 250) who had been analyzed with respect to toxicity and efficacy.

Results

UGT1A1*28 polymorphism was associated with a higher risk of grade 3 to 4 hematologic toxicity (odds ratio [OR], 8.63; 95% CI, 1.31 to 56.55), which was only relevant for the first cycle, and was not seen throughout the whole treatment period for patients with both variant alleles TA7/TA7compared with wild-type TA6/TA6. The response rate was also higher in TA7/TA7patients (OR, 0.32; 95% CI, 0.12 to 0.86) compared with TA6/TA6. A nonsignificant survival advantage was observed for TA7/TA7when compared with TA6/TA6patients (hazard ratio, 0.81; 95% CI, 0.45 to 1.44). Higher response rates were explained by a different pharmacokinetics with higher biliary index [irinotecan area under the curve (AUC)×(SN38 AUC/SN38G AUC)] and lower glucuronidation ratio (SN38G AUC/SN38 AUC) associated with the TA7/TA7genotype and a higher response rate, indicating that the polymorphism is functionally relevant.

Conclusion

The results indicate that UGT1A1*28 polymorphism is of some relevance to toxicity; however, it is less important than discussed in previous smaller trials. In particular, the possibility of a dose reduction for irinotecan in patients with a UGT1A1*28 polymorphism is not supported by the result of this analysis.
Novel Prognostic Immunohistochemical Biomarker Panel for Estrogen Receptor–Positive Breast Cancer
Authors: Ring Brian Z. , Seitz Robert S. , Beck Rod , Shasteen William J. , Tarr Shannon M. , Cheang Maggie C.U. , Yoder Brian J. , Budd G. Thomas , Nielsen Torsten O. , Hicks David G. , Estopinal Noel C. , Ross Douglas T.
Published: June 2006

Purpose

Patients with breast cancer experience progression and respond to treatment in diverse ways, but prognostic and predictive tools for the oncologist are limited. We have used gene expression data to guide the production of hundreds of novel antibody reagents to discover novel diagnostic tools for stratifying carcinoma patients.

Patients and Methods

One hundred forty novel and 23 commercial antisera, selected on their ability to differentially stain tumor samples, were used to stain paraffin blocks from a retrospective breast cancer cohort. Cox proportional hazards and regression tree analysis identified minimal panels of reagents able to predict risk of recurrence. We tested the prognostic association of these prospectively defined algorithms in two independent cohorts.

Results

In both validation cohorts, the Kaplan-Meier estimates of recurrence confirmed that both the Cox model using five reagents (p53, NDRG1, CEACAM5, SLC7A5, and HTF9C) and the regression tree model using six reagents (p53, PR, Ki67, NAT1, SLC7A5, and HTF9C) distinguished estrogen receptor (ER) –positive patients with poor outcomes. The Cox model was superior and distinguished patients with poor outcomes from patients with good or moderate outcomes with a hazard ratio of 2.21 (P = .0008) in validation cohort 1 and 1.88 (P = .004) in cohort 2. In multivariable analysis, the calculated risk of recurrence was independent of stage, grade, and lymph node status. A model proposed for ER-negative patients failed validation in the independent cohorts.

Conclusion

A panel of five antibodies can significantly improve on traditional prognosticators in predicting outcome for ER-positive breast cancer patients.
Phase II Trial of Alfimeprase, a Novel-Acting Fibrin Degradation Agent, for Occluded Central Venous Access Devices
Authors: Moll Stephan , Kenyon Peter , Bertoli Luigi , De Maio James , Homesley Howard , Deitcher Steven R.
Published: June 2006

Purpose

Alfimeprase is a recombinantly produced, genetically modified variant of the metalloproteinase, fibrolase. Alfimeprase proteolytically cleaves fibrin, independent of plasminogen activation to plasmin, and directly dissolves thrombi. Based on the direct fibrin degradation effect of alfimeprase, rapid activity in patients with occluded central venous access devices (CVADs) was hypothesized.

Patients and Methods

We performed a phase II, randomized, double-blind, active-control, multicenter, dose-ranging study to compare the safety and efficacy of one or two instillations of three intraluminal doses of alfimeprase (0.3, 1.0, and 3.0 mg) and alteplase 2.0 mg in re-establishing patency to occluded CVADs in 55 adult patients.

Results

All three alfimeprase doses were more successful than alteplase during the first 15 and 30 minutes of treatment. The alfimeprase 3.0-mg dose resulted in 40%, 50%, and 60% patency restoration rates at 5, 15, and 30 minutes, respectively, compared with 0%, 0%, and 23% for alteplase. The difference at 15 minutes was highly significant (P = .0075). Alfimeprase 3.0 mg produced the highest patency rate at 120 minutes after the first (60%) and second (80%) doses. No major hemorrhagic or embolic events were reported.

Conclusion

A single 1- or 3-mg dose of alfimeprase has the potential to restore function to occluded CVADs rapidly and safely, and to facilitate on-time infusion of vital therapies.
Anatomic Site, Sun Exposure, and Risk of Cutaneous Melanoma
Authors: Whiteman David C. , Stickley Mark , Watt Peter , Hughes Maria Celia , Davis Marcia B. , Green Adèle C.
Published: June 2006

Purpose

Sunlight is the principal environmental risk factor for cutaneous melanoma. A current hypothesis postulates that the role of sunlight in causing melanoma differs according to anatomic site. We tested this hypothesis in a population-based case-case comparative study of melanoma patients.

Methods

Patients were sampled from the Queensland cancer registry in three groups: superficial spreading or nodular melanomas of the trunk (n = 154), of the head and neck (HN; n = 76), and lentigo maligna (LM) and lentigo maligna melanoma (LMM; for both LM and LMM, n = 76). Data were collected on school-age sun exposure and occupational and recreational sun exposure in adulthood. Odds ratios (OR) and 95% CIs were calculated using polytomous logistic regression.

Results

HN melanoma patients were substantially more likely than trunk patients to have higher levels of sun exposure in adulthood (OR, 2.43; 95% CI, 0.98 to 5.99) and specifically, higher levels of occupational exposure (OR, 3.25; 95% CI, 1.32 to 8.00), but lower levels of recreational sun exposure (OR, 0.50; 95% CI, 0.21 to 1.19). LM and LMM patients reported higher occupational exposure and lower recreational sun exposure than trunk melanoma patients, although this was not significant. We found no significant differences between the groups for school-age sun exposures.

Conclusion

Melanomas developing at different body sites are associated with distinct patterns of sun exposure. Melanomas of the head and neck are associated with chronic patterns of sun exposure whereas trunk melanomas are associated with intermittent patterns of sun exposure, supporting the hypothesis that melanomas may arise through divergent causal pathways.
Corticosterone Can Act at the Posterior Paraventricular Thalamus to Inhibit Hypothalamic-Pituitary-Adrenal Activity in Animals that Habituate to Repeated Stress
Authors: Jaferi Azra , Bhatnagar Seema
Published: June 2006

Glucocorticoids released by stress bind to glucocorticoid (GR) and/or mineralocorticoid receptors (MR) to exert negative feedback of subsequent hypothalamic-pituitary-adrenal (HPA) responses to stress. Feedback inhibition is implicated in habituation of HPA activity to repeated exposure to the same (homotypic) stressor. We hypothesized that the posterior paraventricular thalamus (pPVTh) is a site where corticosterone acts to exert negative feedback during repeated stress and that is important for habituation. As previously reported, the pPVTh inhibits HPA responses to homotypic and heterotypic stressors in repeatedly, but not acutely, stressed rats. We conducted a series of experiments involving intra-pPVTh administration of MR and/or GR agonists or antagonists during different time frames over 8 d of restraint. MR exist in the pPVTh, as do GR as shown by our immunocytochemical results. Acute intra-pPVTh injection of MR and/or GR antagonist before the eighth restraint did not alter expression of habituation. Because habituation may develop before d 8, we manipulated GR and MR in the pPVTh throughout 8 d of stress using intra-pPVTh corticosterone implants, which enhanced habituation on d 8 without affecting acute stress responses. Conversely, daily intra-pPVTh injections of GR and MR antagonists on d 1–7 of restraint prevented habituation on d 8. These data suggest that corticosterone released during repeated stress can act at GR and MR in the pPVTh to inhibit HPA responses to homotypic stress. We also found that some GR-containing cells in the pPVTh project to the medial prefrontal cortex and basolateral amygdala, suggesting that pPVTh-induced inhibition of HPA activity is potentially mediated by its projections to these select limbic structures.
Expression and Function of Lysophosphatidic Acid LPA1 Receptor in Prostate Cancer Cells
Authors: Guo Rishu , Kasbohm Elizabeth A. , Arora Puneeta , Sample Christopher J. , Baban Babak , Sud Neetu , Sivashanmugam Perumal , Moniri Nader H. , Daaka Yehia
Published: June 2006

The bioactive phospholipid lysophosphatidic acid (LPA) promotes cell proliferation, survival, and migration by acting on cognate G protein-coupled receptors named LPA1, LPA2, and LPA3. We profiled gene expression of LPA receptors in androgen-dependent and androgen-insensitive prostate cancer cells and found that LPA1 gene is differentially expressed in androgen-insensitive and LPA-responsive but not androgen-dependent and LPA-resistant cells. In human prostate specimens, expression of LPA1 gene was significantly higher in the cancer compared with the benign tissues. The androgen-dependent LNCaP cells do not express LPA1 and do not proliferate in response to LPA stimulation, implying LPA1 transduces cell growth signals. Accordingly, stable expression of LPA1 in LNCaP cells rendered them responsive to LPA-induced cell proliferation and decreased their doubling time in serum. Implantation of LNCaP-LPA1 cells resulted in increased rate of tumor growth in animals compared with those tumors that developed from the wild-type cells. Growth of LNCaP cells depends on androgen receptor activation, and we show that LPA1 transduces Gαi-dependent signals to promote nuclear localization of androgen receptor and cell proliferation. In addition, treatment with bicalutamide inhibited LPA-induced cell cycle progression and proliferation of LNCaP-LPA1 cells. These results suggest the possible utility of LPA1 as a drug target to interfere with progression of prostate cancer.
Androgen-Dependent Mechanisms of Wolffian Duct Development and Their Perturbation by Flutamide
Authors: Welsh Michelle , Saunders Philippa T. K. , Marchetti Nicholas I. , Sharpe Richard M.
Published: June 2006

Androgens play a vital role in Wolffian duct (WD) development, but the mechanisms that underlie this are unknown. The present study used in utero exposure of pregnant rats to the androgen receptor antagonist flutamide (50 or 100 mg/kg) to explore possible mechanisms. Pregnant rats were treated from embryonic d 15.5 (E15.5), and WDs were isolated from fetuses from E17.5–E21.5 and from adults. WD morphology was evaluated, and total length of the duct lumen was determined in fetal samples. Fetal WDs were immunostained for androgen receptor and stromal (inner and outer) and/or epithelial-cell-specific markers and analyzed for cell proliferation and apoptosis. In adulthood, most flutamide-exposed males lacked proximal WD-derived tissues, whereas at E18.5–E19.5, a time when the WD has completely regressed in females, a complete normal WD was present in all flutamide-exposed animals. This suggests that flutamide, at doses of 50 or 100 mg/kg, interferes with WD differentiation, not stabilization. Consistent with this, WD elongation/coiling increased in controls by 204% between E19.5 and E21.5 but increased less significantly (103%) in flutamide-exposed animals. This was associated with reduced cell proliferation, but there was no increase in apoptosis or change in expression of androgen receptor mRNA or protein. Flutamide treatment impaired differentiation of inner stromal cells, shown by decreased expression of smooth muscle actin, before effects were noted in the epithelium, consistent with androgens driving WD development via stromal-epithelial interactions. In conclusion, WD differentiation is far more susceptible to blockade of androgen action than is its initial stabilization, and these effects may be mediated by disruption of stromal-epithelial interactions.
Pituitary Tumor Transforming Gene Overexpression Facilitates Pituitary Tumor Development
Authors: Donangelo Ines , Gutman Shiri , Horvath Eva , Kovacs Kalman , Wawrowsky Kolja , Mount Michael , Melmed Shlomo
Published: June 2006

Intrinsic and extrinsic stimuli result in profound pituitary growth changes ranging from hypoplasia to hyperplasia. Pituitary tumor transforming gene (PTTG) abundance correlates with pituitary trophic status. Mice with Pttg inactivation exhibit pituitary hypoplasia, whereas targeted pituitary PTTG overexpression driven by α-subunit glycoprotein (αGSU) promoter results in focal pituitary hyperplasia. To test the impact of pituitary hyperplasia on tumor development, we crossbred αGSU.PTTG with Rb+/− mice, which develop pituitary tumors with high penetrance. Pituitary glands of resulting bitransgenic αGSU.PTTGxRb+/− mice were compared with monotransgenic αGSU.PTTG, Rb+/−, and wild-type mice. Confocal microscopy showed that PTTG-overexpressing cells have enlarged nuclei and marked redistribution of chromatin, and electron microscopy of αGSU.PTTG pituitaries showed enlarged gonadotrophs with prominent Golgi complexes and numerous secretory granules. These morphological findings were even more remarkable in αGSU.PTTGxRb+/− pituitaries. Mice from all four genotypes were sequentially imaged by magnetic resonance imaging to evaluate pituitary volume, and glands from αGSU.PTTGxRb+/− mice were the largest as early as 2 months of age (P = 0.0003). Cumulative incidence of pituitary tumors visualized by magnetic resonance imaging did not differ between Rb+/− and αGSU.PTTGxRb+/− mice. However, anterior lobe tumors determined after necropsy were 3.5 times more frequent in αGSU.PTTGxRb+/− than in Rb+/− mice (P = 0.0036), whereas the frequency of intermediate lobe tumors was similar. In summary, αGSU.PTTGxRb+/− pituitary glands exhibit enhanced cellular activity, increased volume, and higher prevalence of anterior pituitary tumors, indicating that changes in pituitary PTTG content directly relate to both pituitary trophic status and tumorigenic potential.
Impact of Estrogen Receptor β on Gene Networks Regulated by Estrogen Receptor α in Breast Cancer Cells
Authors: Chang Edmund C. , Frasor Jonna , Komm Barry , Katzenellenbogen Benita S.
Published: June 2006

Two subtypes of the estrogen receptor (ER), ERα and ERβ, mediate the actions of estrogens, and although 70% of human breast cancers express ERβ along with ERα, little is known about the possible comodulatory effects of these two ERs. To investigate this, we have used adenoviral gene delivery to produce human breast cancer (MCF-7) cells expressing different levels of ERβ, along with their endogenous ERα, and have examined the effects of ERβ and receptor occupancy, using ER subtype selective ligands, on genome-wide gene expression by microarray and pathway network analysis. ERβ had diverse effects on gene expression, enhancing or counteracting ERα regulation for distinct subsets of estrogen target genes. Strikingly, ERβ in the absence of estradiol (E2), elicited the stimulation or suppression of many genes that were normally only regulated by ERα with E2. In addition, ERβ plus E2 elicited the expression of a unique group of genes that were not regulated by ERα plus E2 alone. The expression of genes in many functional categories were modulated by ERβ, with the greatest numbers associated with transcription factors and signal transduction pathways. Regulation of multiple components in the TGFβ and semaphorin pathways, and of genes controlling cell cycle progression and apoptosis, may contribute to the suppression of cell proliferation observed with ERβ. Our observations suggest that the relative levels of ERβ and ERα in breast cancers are likely to impact cell proliferation and the activities of diverse signaling pathways and their response to ER ligands and endocrine therapies.
Evidence for a respiratory component, similar to mammalian respiratory sinus arrhythmia, in the heart rate variability signal from the rattlesnake,Crotalus durissus terrificus
Authors: Campbell Hamish A. , Leite Cleo A. C. , Wang Tobias , Skals Marianne , Abe Augusto S. , Egginton Stuart , Rantin F. Tadeu , Bishop Charles M. , Taylor Edwin W.
Published: June 2006

Autonomic control of heart rate variability and the central location of vagal preganglionic neurones (VPN) were examined in the rattlesnake(Crotalus durissus terrificus), in order to determine whether respiratory sinus arrhythmia (RSA) occurred in a similar manner to that described for mammals. Resting ECG signals were recorded in undisturbed snakes using miniature datalogging devices, and the presence of oscillations in heart rate (fh) was assessed by power spectral analysis (PSA). This mathematical technique provides a graphical output that enables the estimation of cardiac autonomic control by measuring periodic changes in the heart beat interval. At fh above 19 min-1spectra were mainly characterised by low frequency components, reflecting mainly adrenergic tonus on the heart. By contrast, at fhbelow 19 min-1 spectra typically contained high frequency components, demonstrated to be cholinergic in origin. Snakes with a fh >19 min-1 may therefore have insufficient cholinergic tonus and/or too high an adrenergic tonus acting upon the heart for respiratory sinus arrhythmia (RSA) to develop. A parallel study monitored fh simultaneously with the intraperitoneal pressures associated with lung inflation. Snakes with a fh<19 min-1 exhibited a high frequency (HF) peak in the power spectrum,which correlated with ventilation rate (fv). Adrenergic blockade by propranolol infusion increased the variability of the ventilation cycle, and the oscillatory component of the fh spectrum broadened accordingly. Infusion of atropine to effect cholinergic blockade abolished this HF component, confirming a role for vagal control of the heart in matching fh and fv in the rattlesnake. A neuroanatomical study of the brainstem revealed two locations for vagal preganglionic neurones (VPN). This is consistent with the suggestion that generation of ventilatory components in the heart rate variability (HRV)signal are dependent on spatially distinct loci for cardiac VPN. Therefore,this study has demonstrated the presence of RSA in the HRV signal and a dual location for VPN in the rattlesnake. We suggest there to be a causal relationship between these two observations.
Characterization of diurnal urea excretion in the mangrove killifish,Rivulus marmoratus
Authors: Rodela Tammy M. , Wright Patricia A.
Published: June 2006

An unusual characteristic of nitrogen excretion in the ammoniotelic mangrove killifish Rivulus marmoratus is that urea is excreted(Jurea) in a distinct diurnal pattern, whereas ammonia is excreted (Jamm) at a steady rate. In this study we tested the hypothesis that the diurnal pattern in R. marmoratus is an endogenously generated pattern that is characterized as a circadian rhythm. This hypothesis was tested by measuring Jurea and Jamm following manipulation of feeding or lighting regimes. The diurnal Jurea pattern in food-deprived R. marmoratus had a 24 h periodicity under normal conditions of 12 h:12 h light:dark (12:12 L:D) with 72% more urea excreted during 12:00 h and 18:00 h. In contrast, there was no significant pattern in Jamm. Fed fish (12:12 L:D) demonstrated a diurnal pattern in both Jurea and Jamm with up to an eightfold increase in excretion rates compared with rates obtained from food-deprived fish. Patterns of Jurea were free running with a 24 h period under conditions of continuous darkness (0:24 L:D). Exposure to an inverse photoperiod (12:12 D:L) resulted in entrainment of the Jurea pattern to the new photoperiod, with the highest rates of excretion occurring during midday of the new photoperiod. In contrast to R. marmoratus, nitrogen excretion rates in the zebrafish Danio rerio remained constant over time. The results of this study show that Jurea in R. marmoratus demonstrates the characteristics of a circadian rhythm: a 24 h periodicity, a free-running rhythm in continuous conditions, and entrainment to new photoperiods.
Metabolic substrate use and the turnover of endogenous energy reserves in broad-tailed hummingbirds (Selasphorus platycercus)
Authors: Carleton Scott A. , Bakken Bradley Hartman , del Rio Carlos Martínez
Published: June 2006

We fed broad-tailed hummingbirds (Selasphorus platycercus) diets of contrasting carbon isotope composition and measured changes in theδ 13C of expired breath through time. By measuring theδ 13C in the breath of fed and fasted birds we were able to quantify the fraction of metabolism fueled by assimilated sugars and endogenous energy reserves. These measurements also allowed us to estimate the fractional turnover of carbon in the hummingbirds' energy reserves. When hummingbirds were feeding, they fueled their metabolism largely (≈90%) with assimilated sugars. The rate of carbon isotope incorporation into the energy reserves of hummingbirds was higher when birds were gaining as opposed to losing body mass. The average residence time of a carbon atom in the hummingbirds' energy reserves ranged from 1 to 2 days.
Tiger moth responses to a simulated bat attack: timing and duty cycle
Authors: Barber J. R. , Conner W. E.
Published: June 2006

Many night-flying insects perform complex, aerobatic escape maneuvers when echolocating bats initiate attack. Tiger moths couple this kinematic defense with an acoustic reply to a bat's biosonar-guided assault. The jamming hypothesis for the function of these moth sounds assumes that tiger moth clicks presented at high densities, temporally locked to the terminal phase of the bat attack will produce the greatest jamming efficacy. Concomitantly, this hypothesis argues that moths warning bats of bad tasting chemicals sequestered in their tissues should call early to give the bat time to process the meaning of the warning signal and that moths calling at low duty cycles are more likely to employ such an aposematic strategy. We report here the first investigation of a tiger moth assemblage's response to playback of a bat echolocation attack sequence. This assemblage of arctiid moths first answered the echolocation attack sequence 960±547 ms (mean ± s.d.) from the end of the bat attack. The assemblage reached a half-maximum response shortly after the first response, at 763±479 ms from the end of the terminal buzz. Tiger moth response reached a maximum at 475±344 ms from the end of the sequence; during the approach phase, well before the onset of the terminal buzz. In short, much of tiger moth response to bat attack occurs outside of the jamming hypotheses' predictions. Furthermore, no relationship exists between the duty cycle of a tiger moth's call (and thus the call's probability of jamming the bat) and its temporal response to bat attack. These data call into doubt the assumptions behind the jamming hypothesis as currently stated but do not directly test the functionality of arctiid sounds in disrupting echolocation in bat-moth aerial battles.
Performance-enhancing role of dietary fatty acids in a long-distance migrant shorebird: the semipalmated sandpiper
Authors: Maillet Dominique , Weber Jean-Michel
Published: June 2006

At the end of summer, semipalmated sandpipers (Calidris pusilla)traveling from the Arctic stop in the Bay of Fundy (east coast of Canada) to build large fat reserves before a non-stop flight to South America. During a 2-week stopover, the body mass of this small shorebird is doubled (∼20 g to 40 g) by feeding on a burrowing amphipod, Corophium volutator,that contains unusually high levels of n-3 polyunsaturated fatty acids (PUFA). In mammals, high n-3 PUFA content of membrane phospholipids (PL) is linked to improved exercise performance due to increased membrane fluidity that accelerates transmembrane lipid transport. We hypothesized that dietary n-3 PUFA could be used as a natural `performance-enhancing substance' by semipalmated sandpipers to prepare their flight muscles for migration. Also,PUFA stored as fuel in neutral lipids (NL) can be mobilized more quickly than saturated fatty acids, but they contain less energy per unit mass. It is therefore unclear whether dietary fatty acids are modified before storage. Birds were collected at various stages of fat loading to examine changes in the composition of tissue PL (membranes) and NL (fuel stores). Results show that dietary n-3 PUFA are incorporated in tissue lipids in less than 2 weeks. During the stopover, the double bond index of muscle PL increases by 25% and the fatty acid profiles of both muscle PL and adipose NL converge with that of the diet. However, >50% of dietary n-3 PUFA are converted to other fatty acids before storage, mainly to oleate (18:1), possibly because monounsaturates offer a compromise between high energy density and ease of mobilization. This study shows that long-distance migrant birds can (1) use natural diets rich in specific lipids to prime flight muscles for endurance exercise, and (2) modify dietary fatty acids before storing them as fuel.
Acoustic radiation from the head of echolocating harbor porpoises(Phocoena phocoena)
Authors: Au Whitlow W. L. , Kastelein Ronald A. , Benoit-Bird Kelly J. , Cranford Ted W. , McKenna Megan F.
Published: June 2006

An experiment was conducted to investigate the sound pressure patterns on the melon of odontocetes by using four broadband hydrophones embedded in suction cups to measure echolocation signals on the surface of the forehead of two harbor porpoises (Phocoena phocoena). It has long been hypothesized that the special lipids found in the melon of odontocetes, and not in any other mammals, focus sounds produced in the nasal region that then propagate through the melon, producing a beam that is directional in both the horizontal and vertical planes. The results of our measurements supported the melon-focusing hypothesis, with the maximum click amplitude, representing the axis of the echolocation beam, located approximately 5.6-6.1 cm from the edge of the animal's upper lip along the midline of the melon. The focusing is not sharp but is sufficient to produce a transmission beam of about 16°. Click amplitude dropped off rapidly at locations away from the location of site of maximum amplitude. Based on comparisons of forehead anatomy from similar sized porpoises, the beam axis coincided with a pathway extending from the phonic lips through the axis of the low-density/low sound velocity lipid core of the melon. The significant interaction between click number and hydrophone position suggests that the echolocation signals can take slightly different pathways through the melon, probably as a result of how the signals are launched by the production mechanism and the position of the acoustically reflective air sacs.
Evidence for a role of orcokinin-related peptides in the circadian clock controlling locomotor activity of the cockroachLeucophaea maderae
Authors: Hofer Sabine , Homberg Uwe
Published: June 2006

The accessory medulla (AMe), a small neuropil in the optic lobe, houses the master circadian clock in the brain of the cockroach Leucophaea maderae and controls circadian rhythms in locomotor activity. Recently,members of the orcokinin family of crustacean neuropeptides were identified in a cockroach and a locust and were shown by immunocytochemistry to be prominently present in the AMe. In the cockroach L. maderae, about 30 neurons in five of six established cell groups of the AMe showed orcokinin immunostaining. By means of tracer injections into one AMe and immunostaining with anti-orcokinin antiserum, we show here that one orcokinin-immunoreactive ventral neuron and three ventromedian neurons directly connect both AMae. To determine a possible circadian function of orcokinin in the cockroach, we injected 150 fmol Asn13-orcokinin into the vicinity of the AMe at different circadian times. These experiments resulted in stable phase-dependent phase shifts of circadian locomotor activity of the cockroach. The shape of the resulting phase-response curve closely matched the phase-shifting effects of light pulses, and its amplitude was dependent on the amount of the injected peptide. Together with the anatomical data, the results suggest that orcokinin-related peptides play an important role in light entrainment pathways to the circadian clock via the contralateral compound eye. This study, furthermore, provides the first evidence for a physiological role of an orcokinin-related peptide in insects.
Dopaminergic regulation of ion transport in gills of the euryhaline semiterrestrial crabChasmagnathus granulatus: interaction between D1- and D2-like receptors
Authors: Genovese Griselda , Senek Mihaela , Ortiz Nicolás , Regueira Mariana , Towle David W. , Tresguerres Martín , Luquet Carlos M.
Published: June 2006

The effects of dopamine (DA) and dopaminergic agonists and antagonists on ion transport were studied in isolated perfused gills of the crab Chasmagnathus granulatus. DA applied under steady state conditions(perfusion with hemolymph-like saline) produced a transient increase of the transepithelial potential difference (Vte) from 2.2±0.2 to 4.8±0.3 mV, describing an initial cAMP-dependent stimulating phase followed by an inhibitory phase. Spiperone and domperidone(antagonists of D2-like DA receptors in vertebrates) completely blocked the response to DA, while the D1-like antagonist SCH23390 blocked only the inhibitory phase. Theophylline (phosphodiesterase inhibitor) and okadaic acid(protein phosphatases PP1 and PP2A inhibitor) were also able to block the inhibitory phase, suggesting that it depends on adenylyl cyclase inhibition and on protein phosphatases. When the gills were perfused with hypo-osmotic solution, or with the adenylyl cyclase activator forskolin, Vte was increased several-fold. DA applied under these stimulated conditions partially reversed the Vte increase by 54% and 25%, respectively. Similarly, the D1-like agonist, fenoldopam,produced a 33% reduction in the stimulated Vte. We propose that, in C. granulatus gills, DA stimulates adenylyl cyclase and therefore ion transport through D1-like receptors linked to a Gs protein,although they respond to antagonists that interact with D2-like receptors in vertebrates. The inhibitory phase seems to be mediated by D2-like receptors linked to a Gi/o protein, which inhibits adenylyl cyclase, although these receptors can be activated or blocked by agonists or antagonists that interact with D1-like receptors in vertebrates and insects.
Dopamine modulation of Ca2+ dependent Cl- current regulates ciliary beat frequency controlling locomotion inTritonia diomedea
Authors: Woodward Owen M. , Willows A. O. Dennis
Published: June 2006

The physiological mechanisms controlling ciliary beating remain largely unknown. Evidence exists supporting both hormonal control of ciliary beating and control via direct innervation. In the present study we investigated nervous control of cilia based locomotion in the nudibranch mollusc, Tritonia diomedea. Ciliated pedal epithelial (CPE) cells acting as locomotory effectors may be electrically excitable. To explore this possibility we characterized the cells' electrical properties, and found that CPE cells have large voltage dependent whole cell currents with two components. First, there is a fast activating outward Cl- current that is both voltage and Ca2+ influx dependent(ICl(Ca)). ICl(Ca) is sensitive to DIDS and 9-AC, and resembles currents of Ca2+-activated Cl- channels (CaCC). Ca2+ dependence also suggests the presence of voltage-gated Ca2+ channels; however, we were unable to detect these currents. The second current, a voltage dependent proton current(IH), activates very slowly and is sensitive to both Zn2+ and changes in pH.

In addition we identify a new cilio-excitatory substance in Tritonia, viz., dopamine. Dopamine, in the 10 μmol l-1-1 mmol l-1 range, significantly increases ciliary beat frequency (CBF). We also found dopamine and Tritonia Pedal Peptide(TPep-NLS) selectively suppress ICl(Ca) in CPE cells,demonstrating a link between CBF excitation and ICl(Ca). It appears that dopamine and TPep-NLS inhibit ICl(Ca) not through changing [Ca2+]in, but directly by an unknown mechanism. Coupling of ICl(Ca) and CBF is further supported by our finding that DIDS and zero [Cl-]outboth increase CBF, mimicking dopamine and TPep-NLS excitation. These results suggest that dopamine and TPep-NLS act to inhibit ICl(Ca),initiating and prolonging Ca2+ influx, and activating CBF excitation.
Minimization of Maximum Acoustic Pressure Over Space and Frequency
Authors: Tseng W-K
Published: June 2006

This paper investigates the performance of a local active noise control system for broadband disturbance using the method of the maximum acoustic pressure minimization over space and frequency. Local active control only attenuates the disturbance at some specified positions, which is different from global active control where the disturbance is attenuated at all positions. The theory and simulations of the maximum acoustic pressure minimization over space and frequency using single-channel, two-channel, and three-channel systems are presented. The work presented in this paper is the first part of the study and only concerns a plane wave primary field with one, two, and three secondary sources for simplicity. Constrained minimization of the pressure is introduced, to achieve control over the pressure in both frequency and space. The results show that good attenuation is achieved at the microphone location or desired range over space and frequency using a single-channel system. However, better performance could be achieved using a two-channel or a three-channel system. In the next part of the study, a more realistic sound field like a diffuse field will be investigated.
Investigation of Droplet-Ejection Characteristics for a Piezoelectric Inkjet Printhead
Authors: Yang A-S , Cheng C-H , Lin C-T
Published: June 2006

Numerical simulations are performed to explore the droplet-ejection process for a piezoelectric inkjet printhead. In the analysis, the theoretical model takes account of a set of three-dimensional, time-dependent conservation equations of mass and momentum, with the incorporation of the continuous surface force model for treating the interfacial surface tension effect. The resultant governing equations are solved using an iterative semi-implicit method for pressure-linked equations consistent algorithm for resolving flow properties. The volume-of-fluid method along with the piecewise linear-interface construction technique is implemented to characterize the behaviour of liquid surface movement. With a typical piezodiaphragm printhead as an illustration case, the time evolution of the gas-liquid interface is calculated for an entire ejection cycle of 164 μs. The predicted droplet shapes throughout the ejection process are compared with microphotographed images for the verification of the present theoretical formulation. The flow and transport phenomena in the stages of the ink ejection and the droplet formation are further examined in detail. In response to design needs, the study is extended to determine the variations of ejection characteristics at different settings of nozzle exit diameter, ejection time interval, surface tension, and viscosity of fluid.
One-Dimensional Analysis on the Dynamic Response of Cellular Chains to Pulse Loading
Authors: Gao Z. Y. , Yu T. X.
Published: June 2006

On the basis of our previous studies of a typical type II structure (i.e. a pair of prebent plates), a simplified one-dimensional mass-spring model is proposed to describe the uniaxial load-deformation characteristic of cellular materials and structures. When compared with the previous mass-spring model proposed by Shim et al., the present model employs fewer parameters (only two) to describe elastic-plastic behaviour, and the structural hardening/softening is represented by only one of the parameters. The model is then used to study the dynamic response of a cellular chain to a pulse loading of specified force intensity and duration. By adjusting the value of a single parameter adopted in the model, each cell of the cellular chain is identically assigned to possess either an elastic-hardening or an elastic-softening-consolidation property. The effects of material elasticity, cell compliance characteristic, cell number, and pulse intensity and duration are all examined by this model and discussed in detail. A special attention is paid to the initiation and propagation of the plastic collapse of the cells in the cellular chain so as to identify the governing parameters. Apart from the elastic wave speed, two other characteristic velocities, i.e. the particle velocity induced by the elastic wave and the plastic collapse propagation velocity, are defined and analytically evaluated. It is found that these three characteristic velocities completely govern the elastic and plastic dynamic behaviour of the cellular chains.