Robust but weak winter atmospheric circulation response to future Arctic sea ice loss

The possibility that Arctic sea ice loss weakens mid-latitude westerlies, promoting more severe cold winters, has sparked more than a decade of scientific debate, with apparent support from observations but inconclusive modelling evidence. Here we show that sixteen models contributing to the Polar Amplification Model Intercomparison Project simulate a weakening of mid-latitude westerlies in response to projected Arctic sea ice loss. We develop an emergent constraint based on eddy feedback, which is 1.2 to 3 times too weak in the models, suggesting that the real-world weakening lies towards the higher end of the model simulations. Still, the modelled response to Arctic sea ice loss is weak: the North Atlantic Oscillation response is similar in magnitude and offsets the projected response to increased greenhouse gases, but would only account for around 10% of variations in individual years. We further find that relationships between Arctic sea ice and atmospheric circulation have weakened recently in observations and are no longer inconsistent with those in models.

Impact of Covid-19 on farming systems in Europe through the lens of resilience thinking

CONTEXT

Resilience is the ability to deal with shocks and stresses, including the unknown and previously unimaginable, such as the Covid-19 crisis.

OBJECTIVE

This paper assesses (i) how different farming systems were exposed to the crisis, (ii) which resilience capacities were revealed and (iii) how resilience was enabled or constrained by the farming systems' social and institutional environment.

METHODS

The 11 farming systems included have been analysed since 2017. This allows a comparison of pre-Covid-19 findings and the Covid-19 crisis. Pre-Covid findings are from the SURE-Farm systematic sustainability and resilience assessment. For Covid-19 a special data collection was carried out during the early stage of lockdowns.

RESULTS AND CONCLUSIONS

Our case studies found limited impact of Covid-19 on the production and delivery of food and other agricultural products. This was due to either little exposure or the agile activation of robustness capacities of the farming systems in combination with an enabling institutional environment. Revealed capacities were mainly based on already existing connectedness among farmers and more broadly in value chains. Across cases, the experience of the crisis triggered reflexivity about the operation of the farming systems. Recurring topics were the need for shorter chains, more fairness towards farmers, and less dependence on migrant workers. However, actors in the farming systems and the enabling environment generally focused on the immediate issues and gave little real consideration to long-term implications and challenges. Hence, adaptive or transformative capacities were much less on display than coping capacities. The comparison with pre-Covid findings mostly showed similarities. If challenges, such as shortage of labour, already loomed before, they persisted during the crisis. Furthermore, the eminent role of resilience attributes was confirmed. In cases with high connectedness and diversity we found that these system characteristics contributed significantly to dealing with the crisis. Also the focus on coping capacities was already visible before the crisis. We are not sure yet whether the focus on short-term robustness just reflects the higher visibility and urgency of shocks compared to slow processes that undermine or threaten important system functions, or whether they betray an imbalance in resilience capacities at the expense of adaptability and transformability.

SIGNIFICANCE

Our analysis indicates that if transformations are required, e.g. to respond to concerns about transnational value chains and future pandemics from zoonosis, the transformative capacity of many farming systems needs to be actively enhanced through an enabling environment.

How often we diagnose allergy to ranitidine?

H2 receptors' antagonists (H2RA) are widely used drugs and they are generally well-tolerated. Ranitidine hypersensitivity reactions (HR) are rarely reported. The article emphasizes the importance of recognizing ranitidine as a cause of anaphylaxis and the advantages and limits of allergological evaluation to establish a positive diagnose. We reviewed a series of published cases of ranitidine-induced hypersensitivity reactions, starting from a clinical case presentation. Moreover, we analyzed the ranitidine related adverse events in the Eudravigilance European database of adverse reactions. Most of the allergic reactions induced by ranitidine are type I HR with immediate onset after exposure, with variable clinical presentation. But in a few cases, there were also described delayed reactions, some after occupational exposure. The article underlines the importance of allergy evaluation to avoid future contact with the drug to reduce the risk of more severe reactions. The suspected reactions should be reported, allowing pharmacovigilance systems to analyse them and to establish further recommendations for clinicians.

Celiac disease: a multi-faceted medical condition

Celiac disease (CD) is a systemic condition of autoimmune origin, affecting genetically predisposed individuals who at some point lose tolerance towards dietary gluten. Prevalence in the general population is 0.5 - 1%, with a higher frequency in women. The most important environmental factor for CD is ingestion of specific gluten peptides. It triggers a sequence of molecular events, involving the intestinal permeability and the immune system, which ends in damage of the intestinal mucosa. A number of studies have demonstrated the correlation between the intestinal microbiota and celiac disease. MicroRNAs through their regulatory role on gene expression have been implicated in the pathogenesis of CD and suggested as potential biomarkers. In the pediatric and adult population, CD displays different clusters of clinical symptoms. Persistent diarrhea, abdominal pain and involuntary weight loss are the classic symptoms of CD. In the majority of cases diagnosis relies on the combination of serum autoantibodies (anti-transglutaminase and anti-endomisium IgA) and duodenal biopsy showing villous atrophy, crypt hyperplasia and intraepithelial lymphocytes. Observance of a lifelong gluten-free diet, which interrupts the immune response to gluten peptides, is the only effective treatment of CD.

Linear and nonlinear parameters of heart rate variability in ischemic stroke patients

INTRODUCTION

Cardiovascular system presents cortical modulation. Post-stroke outcome can be highly influenced by autonomic nervous system disruption. Heart rate variability (HRV) analysis is a simple non-invasive method to assess sympatho-vagal balance.

OBJECTIVES

The purpose of this study was to investigate cardiac autonomic activity in ischemic stroke patients and to asses HRV nonlinear parameters beside linear ones.

METHODS

We analyzed HRV parameters in 15 right and 15 left middle cerebral artery ischemic stroke patients, in rest condition and during challenge (standing and deep breathing). Data were compared with 15 age- and sex-matched healthy controls.

RESULTS

There was an asymmetric response after autonomic stimulation tests depending on the cortical lateralization in ischemic stroke patients. In resting state, left hemisphere stroke patients presented enhanced parasympathetic control of the heart rate (higher values for RMSSD, pNN50 and HF in normalized units). Right hemisphere ischemic stroke patients displayed a reduced cardiac parasympathetic modulation during deep breathing test. Beside time and frequency domain, using short-term ECG monitoring, cardiac parasympathetic modulation can also be assessed by nonlinear parameter SD1, that presented strong positive correlation with time and frequency domain parameters RMSSD, pNN50, HFnu, while DFA α1 index presented negative correlation with the same indices and positive correlation with the LFnu and LF/HF ratio, indicating a positive association with the sympatho-vagal balance.

CONCLUSIONS

Cardiac monitoring in clinical routine using HRV analysis in order to identify autonomic imbalance may highlight cardiac dysfunctions, thus helping preventing potential cardiovascular complications, especially in right hemisphere ischemic stroke patients with sympathetic hyperactivation.

Autonomic impairment in patients with migraine

OBJECTIVE

Heart rate variability analysis of electrocardiogram is becoming an increasingly common method to non-invasively evaluate autonomic nervous function. The aim of the study was to investigate cardiac autonomic function in subjects with and without migraine by using 24-hour ambulatory electrocardiographic recordings.

PATIENTS AND METHODS

We investigated 27 subjects with migraine (10 with migraine with aura and 17 without aura) during headache free periods and 10 age-matched healthy control subjects. The migraine was diagnosed using the International Classification of Headache Disorders 2nd Edition criteria. Beck Depression and Beck Anxiety Inventory forms were completed by all subjects. Time and frequency-domain of HRV was analyzed for two periods: diurnal and nocturnal.

RESULTS

We found an increased frequency of anxiety and depressive symptoms in migraine patients, especially in migraine with aura group. The heart rate variability parameters SDNN, RMSSD, high frequency were decreased and low frequency was increased in migraine patients during night period compared with normal subjects, most affected were migraine with aura patients. During day period we found modification for SDNN, RMSSD and high frequency parameters only in migraine with aura group.

CONCLUSIONS

Reduced parasympathetic activity with sympathetic predominance was found in migraine patients during the night period, most affected being migraine with aura patients.

β-Catenin-regulated ALDH1A1 is a target in ovarian cancer spheroids

Cancer cells form three dimensional (3D) multicellular aggregates (or spheroids) under non-adherent culture conditions. In ovarian cancer (OC), spheroids serve as a vehicle for cancer cell dissemination in the peritoneal cavity, protecting cells from environmental stress-induced anoikis. To identify new targetable molecules in OC spheroids, we investigated gene expression profiles and networks upregulated in three dimensional (3D) versus traditional monolayer culture conditions. We identified ALDH1A1, a cancer stem cell marker as being overexpressed in OC spheroids and directly connected to key elements of the β-catenin pathway. B-catenin function and ALDH1A1 expression were increased in OC spheroids vs. monolayers and in successive spheroid generations, suggesting that 3D aggregates are enriched in cells with stem cell characteristics. B-catenin knockdown decreased ALDH1A1 expression levels and β-catenin coimmunoprecipitated with the ALDH1A1 promoter, suggesting that ALDH1A1 is a direct β-catenin target. Both siRNA mediated β-catenin knockdown and A37, a novel ALDH1A1 small molecule enzymatic inhibitor described here for the first time, disrupted OC spheroid formation and cell viability (p<0.001). B-catenin knockdown blocked tumor growth and peritoneal metastasis in an OC xenograft model. These data strongly support the role of β-catenin regulated ALDH1A1 in the maintenance of OC spheroids and propose new ALDH1A1 inhibitors targeting this cell population.

Abstract P2-09-02: BMN 673 is a PARP inhibitor in clinical development for the treatment of breast cancer patients with deleterious germline BRCA 1 and 2 mutations

Background: BMN 673 is the most potent and specific inhibitor of poly-ADP ribose polymerase (PARP) 1 and 2 in clinical development (IC50&lt;1nM). In BRCA-related tumors, which are genetically dependent on PARP-mediated DNA repair by base excision repair, PARP inhibition induces synthetic lethality. Initial phase 1 results have been presented (de Bono et al JCO 31:5s, 2013 suppl; abstr 2580), showing good tolerability and anti-tumor activity with an MTD on a daily, oral dosing schedule of 1000 μ/day.

Methods: In this 2-stage study, patients with solid tumors including BRCA-related cancers, were enrolled during dose-escalation followed by an expansion phase at the MTD in breast, ovarian, and pancreatic cancer patients with deleterious germline BRCA mutations and in small cell lung cancer and Ewing sarcoma patients to further characterize safety and efficacy. This abstract summarizes demographics and safety for all patients and efficacy for patients with BRCA-related cancers.

Results: As of 17May2013, a total of 1 pancreatic, 18 breast (17F/1M), and 28 ovarian cancer pts with germline BRCA mutations were enrolled at doses from 100-1100 μg/day. All breast cancer patients were treated from 900-1100 μg/day. The median (range) age for all 70 patients is 51.5 (18-81), PS 0 (0-1) and # of prior therapies 4 (1-13), with 47 patients having deleterious BRCA mutations. An MTD of 1000 μg/day was established with thrombocytopenia being dose-limiting. Related adverse events occurring in &gt; 10% of all 70 patients included fatigue, nausea, alopecia, anemia, thrombocytopenia and neutropenia. One patient has had related grade 4 thrombocytopenia. Grade 3 related AE's included fatigue in 1 patient (1%), anemia and thrombocytopenia in 9 each (13%) and neutropenia in 4 (6%). Dose reductions occurred in 11 pts due to myelosuppression. No patients discontinued for adverse events.

Response in Germline BRCA PatientsBRCA Tumor TypeNDose Range (μ/day)ResponseBreast18900-11001CR/6PR/5SD≥12 weeksOvarian28100-11001CR/10PR/19GCIG/4SD≥24 weeksPancreas110001 SD ≥ 12weeksTwo of 2 BRCA breast responders had responded to prior platinum while 0 of 4 non-responders to prior platinum responded to BMN 673. Five of 12 breast cancer pts with no prior platinum have responded.

Conclusions: BMN 673 is well tolerated with impressive anti-tumor activity in pts with deleterious germ line BRCA mutations. Myelosuppression and fatigue are the primary side effects associated with need for dose reduction. A phase 3 trial in metastatic breast cancer patients with deleterious germ line BRCA mutations is planned with single-agent, once-daily oral dosing of 1000 μg (1 mg) per day.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-09-02.

Epithelial ovarian cancer experimental models

Epithelial ovarian cancer (OvCa) is associated with high mortality and, as the majority (>75%) of women with OvCa have metastatic disease at the time of diagnosis, rates of survival have not changed appreciably over 30 years. A mechanistic understanding of OvCa initiation and progression is hindered by the complexity of genetic and/or environmental initiating events and lack of clarity regarding the cell(s) or tissue(s) of origin. Metastasis of OvCa involves direct extension or exfoliation of cells and cellular aggregates into the peritoneal cavity, survival of matrix-detached cells in a complex ascites fluid phase and subsequent adhesion to the mesothelium lining covering abdominal organs to establish secondary lesions containing host stromal and inflammatory components. Development of experimental models to recapitulate this unique mechanism of metastasis presents a remarkable scientific challenge, and many approaches used to study other solid tumors (for example, lung, colon and breast) are not transferable to OvCa research given the distinct metastasis pattern and unique tumor microenvironment (TME). This review will discuss recent progress in the development and refinement of experimental models to study OvCa. Novel cellular, three-dimensional organotypic, and ex vivo models are considered and the current in vivo models summarized. The review critically evaluates currently available genetic mouse models of OvCa, the emergence of xenopatients and the utility of the hen model to study OvCa prevention, tumorigenesis, metastasis and chemoresistance. As these new approaches more accurately recapitulate the complex TME, it is predicted that new opportunities for enhanced understanding of disease progression, metastasis and therapeutic response will emerge.

Mortality and need of surgical treatment in acute upper gastrointestinal bleeding: a one year study in a tertiary center with a 24 hours / day-7 days / week endoscopy call. Has anything changed?

BACKGROUND

Acute upper gastrointestinal bleeding, previously often a surgical problem, is now the most common gastroenterological emergency.

AIM

To evaluate the current situation in terms of mortality and need of surgery.

SUBJECTS AND METHODS

Retrospective non-randomised clinical study performed between 1st January-31st December 2011, at "Professor Dr. Octavian Fodor" Regional Institute of Gastroenterology and Hepatology in Cluj Napoca. 757 patients with upper gastrointestinal bleeding were endoscopically examined within 24 hours from presentation in the emergency unit. Data were collected from admission charts and Hospital Manager programme. Statistical analysis was performed with GraphPad 2004, using the following tests: chi square, Spearman, Kruskall-Wallis, Mann-Whitney, area under receiver operating curve.

RESULTS

Non-variceal etiology was predominant, the main cause was bleeding being peptic ulcer. In hospital global mortality was of 10.43%, global rebleeding rate was 12.02%, surgery was performed in 7.66% of patients. Urgent haemostatic surgery was needed in 3.68% of patients with nonvariceal bleeding. The need for surgery correlated with the postendoscopic Rockall score (p=0.0425). In peptic ulcer, the need for surgery was not influenced by time to endoscopy or type of treatment (p=0.1452). Weekend (p=0.996) or night (p=0.5414) admission were not correlated with a higher need for surgery.

CONCLUSIONS

Over the last decade, the need for urgent surgery in upper gastrointestinal bleeding has decreased by half, but mortality has remained unchanged.

One-dimensional to three-dimensional ripple-to-dome transition for SiGe on vicinal Si (1 1 10)

SiGe heteroepitaxy on vicinal Si (1 1 10) is studied as a model system for one-dimensional (1D) to three-dimensional growth mode transitions. By in situ scanning tunneling microscopy it is shown that the 1D-3D transition proceeds smoothly from perfectly facetted 1D nanoripples to coarsened superripples, tadpoles, asymmetric domes, and barns without involving coalescence or agglomeration. By extension of the studies to a wide range of SiGe compositions, a 1D-3D growth phase diagram is obtained. Total energy calculations reveal that the observed critical transition volumes are fully consistent with thermodynamic driven strain relaxation.

Formation of Ge nanoripples on vicinal Si (1110): from Stranski-Krastanow seeds to a perfectly faceted wetting layer

Ge growth on high-indexed Si (1110) is shown to result in the spontaneous formation of a perfectly {105} faceted one-dimensional nanoripple structure. This evolution differs from the usual Stranski-Krastanow growth mode because from initial ripple seeds a faceted Ge layer is formed that extends down to the heterointerface. Ab initio calculations reveal that ripple formation is mainly driven by lowering of surface energy rather than by elastic strain relief and the onset is governed by the edge energy of the ripple facets. Wavelike ripple replication is identified as an effective kinetic pathway for the transformation process.

Tissue transglutaminase links TGF-β, epithelial to mesenchymal transition and a stem cell phenotype in ovarian cancer

Tissue transglutaminase (TG2), an enzyme involved in cell proliferation, differentiation and apoptosis is overexpressed in ovarian carcinomas, where it modulates epithelial-to-mesenchymal transition (EMT) and promotes metastasis. Its regulation in ovarian cancer (OC) remains unexplored. Here, we show that transforming growth factor (TGF)-β, a cytokine involved in tumor dissemination is abundantly secreted in the OC microenvironment and induces TG2 expression and enzymatic activity. This is mediated at transcriptional level by SMADs and by TGF-β-activated kinase 1-mediated activation of the nuclear factor-κB complex. TGF-β-stimulated OC cells aggregate as spheroids, which enable peritoneal dissemination. We show that TGF-β-induced TG2 regulates EMT, formation of spheroids and OC metastasis. TG2 knock-down in OC cells decreases the number of cells harboring a cancer stem cell phenotype (CD44+/CD117+). Furthermore, CD44+/CD117+ cells isolated from human ovarian tumors express high levels of TG2. In summary, TGF-β-induced TG2 enhances ovarian tumor metastasis by inducing EMT and a cancer stem cell phenotype.

Sorafenib in combination with weekly topotecan in recurrent ovarian cancer, a phase I/II study of the Hoosier Oncology Group

OBJECTIVE

This trial determined the efficacy and tolerability of sorafenib and weekly topotecan in patients with platinum-resistant ovarian cancer (OC) or primary peritoneal carcinomatosis (PPC).

METHODS

Primary endpoints were maximum tolerated dose of sorafenib with weekly topotecan (phase I) and response rate (phase II). Secondary endpoints were progression free survival (PFS), overall survival (OS), toxicity, and rate of clinical benefit. Eligibility included recurrent platinum-resistant OC or PPC, <3 prior regimens, normal end-organ function. 3+3 dose escalation was used for phase I, sorafenib being tested at 400mg and 800 mg orally daily. Topotecan dose was reduced from 4 mg/m(2) to 3.5mg/m(2) IV weekly. The phase II regimen was sorafenib 400mg daily and topotecan 3.5mg/m(2) weekly on days 1, 8, 15 of a 28 days cycle.

RESULTS

16 patients were enrolled in phase I and 14 patients in phase II. Median age was 52.5 years (range 35-79), 27 patients had OC, and 3 PPC. Median number of cycles administered was 2.5 (0-15). There were 5 partial responses (PR) (16.7%), and 14 patients (46.7%) with stable disease (SD). Four PRs were recorded during phase I and 1 during phase II. One of those PRs occurred in a patient with platinum-sensitive disease. Grade 3/4 toxicities included leukopenia/neutropenia (23%), thrombocytopenia (17%), anemia (10%), fatigue, nausea, vomiting (7% each). One case of grade 3 hand-foot syndrome was recorded.

CONCLUSIONS

The combination of sorafenib and topotecan causes significant toxicity, precluding administration of full doses and resulting in modest clinical efficacy in platinum resistant OC or PPC.

Value of immunohistochemical investigation in the diagnosis of neuromuscular diseases in children

Neuromuscular diseases represent an important group in pediatric pathology. Immunohistochemistry together with clinical examination and morphologic exam are very important in the diagnosis of neuromuscular disorders.

PATIENTS AND METHODS

One hundred children diagnosed with neuromuscular disorders were included in a prospective-retrospective study in 25 years.

RESULTS

There were 58 neurogenic diseases and 42 muscular dystrophies. In positive and differential diagnosis very important were the morphologic and immunohistochemical investigations. Seventy-three percent had positive family history and 27% of dystrophic patients had "de novo" mutations. The most part of the neurogenic disorders were spinal motor atrophies, 91.38%.

CONCLUSIONS

Neurogenic muscular diseases were the most common neuromuscular diseases in our patient group. The immunohistochemical investigation was very useful in diagnosing some of these cases.

An Exploratory Study of the Biological Activity of Sunitinib as a Component of Neoadjuvant Therapy for Breast Cancer

Background: The neoadjuvant setting provides an ideal opportunity to explore the impact of sunitinib alone and in combination with paclitaxel on the functional status of tumor vasculature as indicated by changes in tumor interstitial pressure (IFP) and circulating progenitor cell (CPC) subsets.Methods: Patients(pts.) with newly diagnosed stage Ic-IIIc breast cancer were treated with sunitinib monotherapy (100 mg Day 1; 37.5 mg D2-14) prior to the initiation of paclitaxel (80 mg/M2 D1,8,15 every 28 days x 4 cycles) with sunitinib (25 mg/d). IFP and CPC subsets were assessed at baseline and after sunitinib monotherapy. IFP was measured in three separate areas of the tumor using a micropressure transducer catheter; mean and highest IFP recorded were analyzed. Improvements in poly-chromatic flow cytometry allowed distinction of pro-angiogenic (pCPC = Live/AC133+CD34bright/CD31+CD45dim\), from non-angiogenic (nCPC = Live/AC133-CD34bright/CD31+/CD45dim\), CPCs that cannot be quantified separately using previously reported protocols1. Baseline CPC subsets were also compared to age and gender matched healthy controls.Results: From July 2008 to May 2009, 14 pts were enrolled; baseline and post-sunitinib IFP and CPC data are available for 12 and 11 pts respectively. The median age was 48 (range 32-69). Mean pretreatment tumor diameter was 3.2 cm. Sunitinib monotherapy was generally well tolerated; two patients developed grade III toxicities including hypertension (n=1) and hand-foot syndrome (n=1). Sunitinib significantly decreased mean IFP (18.87 mmHg vs. 6.38 mmHg; p=0.002); similar results were obtained when only the maximum IFP was considered (22.32 mmHg vs. 8.36 mmHg; p=0.003). pCPC frequency was not different between pts and healthy controls (0.099% vs. 0.076%, p=0.24) but the p:nCPC ratio was significantly higher in pts compared to healthy controls (3.26 vs. 1.46; p=0.001) suggesting a shift toward vascular damage and/or active angiogenesis. Both pCPC frequency (0.099 vs. 0.022; p=0.001) and p:nCPC ratio (3.26 vs. 0.78; p=0.001) significantly decreased after sunitinib monotherapy. Analysis of paclitaxel + sunitinib is too early (n=4).Conclusion: Sunitinib, through its effects on VEGF-mediated vascular permeability, markedly reduces tumor IFP. In addition sunitinib profoundly reduces pCPCs that are thought to be important for angiogenesis in human cancers. Accrual is ongoing (planned N=40). Analysis of IFP and CPC subsets after paclitaxel + sunitinib as well as additional correlates will be presented.1 Duda et al. (2007). Nat. Protocol 2, 805-810.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 202.

Integrated report of the phase 2 experience with XL999 administered IV to patients (pts) with NSCLC, renal cell CA (RCC), metastatic colorectal CA (CRC), recurrent ovarian CA, acute myelogenous leaukemia (AML), and multiple myeloma (MM)

3591

Background: XL999 is a potent spectrum-selective inhibitor of tyrosine kinases including VEGFR2/KDR, FGFR1/3, PDGFR-β, FLT3, RET, KIT, & SRC. A Ph 1 study in pts w/advanced malignancies has shown anti-tumor activity (3 PRs &10 SD lasting 3–26+ months) DLTs were cardiac failure & transaminase elevation. Methods: XL999 is being investigated in 6 Ph 2 trials. Pts w/histologically confirmed NSCLC, RCC, CRC, recurrent ovarian CA, AML, & MM were enrolled. The primary objectives of these independent studies are to determine response rate and further evaluate safety and tolerability of XL999. The secondary objectives are to assess PFS, duration of response & OS. Pts receive a once wkly 4hr IV administration of XL999 (2.4 mg/kg). Tumor response is assessed every 8 wks. Results: A total of 79 pts were treated. A confirmed PR was reported in 1/ 9 pts w/NSCLC. An additional 2 pts have SD at 2 & 3 months w/1 showing tumor shrinkage (24%). Two of 11 pts w/RCC have SD at 2 & 4 months. Of 14 pts enrolled w/AML, 1 of 3 with an activating FLT3 mutation had a PR, and 8 of 10 w/circulating myeloblasts had >50% reduction in myeloblasts. AEs = Grade 2 in =10% of pts related to XL999 included N/V, constipation, diarrhea, dry mouth, oral hypoesthesia, fatigue, pyrexia, dizziness, dysguesia, & hypertension. Cardiovascular (CV) events considered SAEs were reported in 11 pts (14%), and all but 1 occurred with the 1st dose of XL999.These events were characterized by ST /T wave changes in ECG,LVEF decreases and /or troponin elevation. Most pts with CV SAEs recovered to baseline within 2–3 wks upon withdrawl of further XL999. Conclusions: XL999 administered IV at a dose of 2.4mg/kg wkly was associated w/CV AEs, the majority of which were associated w/the 1st dose and were generally reversible upon XL999 discontinuation. XL999 shows preliminary evidence of anti- tumor activity in pts w/NSCLC & AML.

[Table: see text]

Induction of VEGF secretion in ovarian cancer by PDGF BB

5557

Background: We identified the PDGFR as a potential target in epithelial ovarian carcinoma (EOC). This led us to test whether inhibition of the receptor affects ovarian cancer cell proliferation and survival and regulates other processes critical to tumor growth and metastasis. We postulated that the PDGF-PDGFR axis regulates VEGF secretion in EOC. Methods: VEGF secretion in ovarian tumors, cancer cells, serum and ascites was measured by IHC, Western Blot and ELISA. The HOG Gyn03–62 protocol was a phase II protocol for patients with recurrent platinum resistant EOC. Patients were treated with imatinib and docetaxel. Serum and tumor samples from patients enrolled on this protocol were analyzed for VEGF. Results: VEGF expression was quantified by IHC in ovarian tumors. Of 21 PDGFR expressing ovarian tumors, seven specimens immunostained strongly for VEGF and six tumors demonstrated 2+ VEGF reactive extracellular (secreted) material. PDGF and VEGF secretion was measured in 17 specimens of malignant EOC ascites. The levels of PDGF BB and VEGF were strongly correlated (Pearson coefficient =0.728, p-value=0.001), suggesting that the two pathways interconnect. There was no correlation between PDGF AA and VEGF levels. VEGF levels were measured in 13 paired serum samples from patients enrolled in the clinical protocol HOG: Gyn03–62, before and after treatment. VEGF serum levels were stabilized or decreased in 9 of 13 EOC patients treated with imatinib. In conditioned media from primary cells, VEGF secretion was four fold higher for tumor derived cells than for cells derived from the normal ovarian epithelium. PDGF increased ten-fold VEGF secretion in PDGFR expressing immortalized ovarian cells (C272/hTert/E7 and C889/hTert), while imatinib reduced VEGF production to basal state. The effects of imatinib were mediated via inhibition of Akt and MAPK pathways, by stabilization of HIF1 alpha. In ovarian cancer cells overexpressing consitutively active Akt, imatinib inhibited only partially the secretion of VEGF compared to control cells, suggesting that the PI3K/Akt pathway is significantly implicated in PDGF-stimulated VEGF secretion. Conclusions: These results suggest that by blocking the PDGFR, imatinib inhibits VEGF production. This affects the tumor microenvironment favoring ovarian tumor growth and metastasis.

No significant financial relationships to disclose.

A phase II trial of the mTOR inhibitor AP23573 as a single agent in advanced endometrial cancer

5516

Background: There are few effective therapies for women with advanced or recurrent endometrial cancer. Targeted therapies such as AP23573, a novel mTOR inhibitor, may result in clinical benefit with fewer side effects. Preliminary results of a trial of single agent AP23573 in patients with progressive endometrial cancer who may have had up to 2 prior regimens of cytotoxic chemotherapy are reported. Methods: The trial is an open-label, Simon 2-stage, single-arm study enrolling patients who have advanced endometrial cancer with documented progression in the 3 months prior to entry. Patients receive 12.5mg AP23573 QDx5 as a 30-min. intravenous infusion every other week for 28-day cycles. The primary efficacy endpoint is Clinical Benefit Response (CBR), defined as a complete or partial response or prolonged stable disease (= 16 weeks) by modified RECIST guidelines. Results: Seven of the first 19 patients achieved CBR, allowing expansion to the second stage. Enrollment is now complete (45 patients). Demographic data are available for 35 (median 66 yrs.; range 46–89) patients who received treatment: 23 adenocarcinomas, 5 carcinosarcomas, 6 papillary serous carcinomas (UPSC) and 1 clear cell carcinoma. Thirty-four patients had prior chemotherapy including doxorubicin, taxanes or platinum agents. Fourteen of the 26 patients with available history had prior pelvic radiotherapy. Nine of 27 (33%) patients evaluable for response had CBRs, including 2 partial responses (PRs). One CBR had UPSC, the remaining patients, including the PRs, had adenocarcinomas. Seven of the patients achieving CBR are still on treatment. Eighteen of the 27 patients discontinued treatment before 4 cycles because of progressive disease (14), consent withdrawal (1) or unrelated adverse events (3). Adverse event data are available for 27 patients. The most common adverse events are fatigue, anemia (33% each), mouth sores and nausea/vomiting (30% each). There have been 16 grade 3/ 4 treatment related adverse events (2 hyperglycemia, 14 separate events similar to those reported in other AP23573 trials). Conclusions: AP23573 shows encouraging single-agent activity in pretreated patients with advanced, progressive endometrial cancer and is well tolerated.

No significant financial relationships to disclose.

Single agent, canfosfamide (C, TLK286) vs pegylated liposomal doxorubicin (D) or topotecan (T) in 3rd-line treatment of platinum (P) refractory or resistant ovarian cancer (OC): Phase 3 study results

LBA5528

Background: Canfosfamide (C) is a novel glutathione analog prodrug activated by glutathione S-transferase P1–1. P resistant OC has a poor prognosis and non-P agents are used for palliation. C reported objective responses in multicenter Phase 2 OC trials. Methods: Pts with P resistant OC who progressed after D or T, measurable disease (RECIST), adequate liver/renal/bone marrow function were eligible. Randomization was stratified by prior D or T treatment, ECOG PS (0 or 1 vs 2) and presence or absence of bulky disease (= 5cm). Patients received C at 1000 mg/m2 IV q3wks, or to D at 50 mg/m2 IV q4wks or T at 1.5 mg/m2 IV daily × 5 q3wks until progression. The trial had a 90% power to detect a 29% reduction in the relative risk of death. Results: 461 pts (C=232 and D or T=229) received 1052 cycles [median 3; range (r) 1–33], 699 (median 4; r 1–32), and 469 (median 5; r 1–21) for C, D and T respectively. Most common Grade 3–4 AEs for C were: nausea (31.6%), vomiting (8.7%), fatigue (6.1%), and anemia (5.6%), for D/T were: nausea (55.3%), anemia (15.2%), fatigue (6.9%), neutropenia (23.5%), thrombocytopenia (12.4%), febrile neutropenia (6%), stomatitis (6%), and PPE syndrome (6%). ORR for C was 4.3% including a CR, vs 10.9% ORR for D/T. Median survival (MS) was 8.5 mos for C, 13.6 mos for D/T (p=0.0001). Median progression-free survival was 2.3 mos for C and 4.4 mos for D/T, (p=0.0001). D/T MS was 14.2/10.8 mos, respectively. Conclusions: Canfosfamide did not meet the primary endpoint. C demonstrated single agent activity in P refractory or resistant OC and was well tolerated. C in combination with standard agents in less heavily treated OC trials are in progress.

No significant financial relationships to disclose.

First detection of human metapneumovirus in children with respiratory infections in Romania

The human metapneumovirus (hMPV) was first isolated in 2001 in the Netherlands (Van der Hoogen and collaborators) from a nasopharyngeal aspirate sampled from an infant. Based on the morphological, biochemical and genetic characteristics, the hMPV was initially classified in the genus Metapneumovirus with the avian metapneumovirus (APV), the agent causing the respiratory infections of the upper tract in turkeys and other birds. Subsequently, together with the respiratory syncytial virus (RSV), it was classified in the Pneumovirus genus which is a part of the Pneumovirinae subfamily, the Paramyxoviridae family. The aim of the present study was to optimize hMPV molecular detection and to detect the virus in samples form children with respiratory infections in Romania. Two types of RTPCR commercial kits were evaluated for the detection of hMPV. Tests were performed on 28 pharyngeal exudates from children aged from 9 months to 6 years, which were negative for influenza viruses and for Respiratory Syncytial Virus (RSV). Among the tested samples 7 (25%) have been positive for hMPV by RT-PCR. These results document for the first time that hMPV is circulating in Romania and causes respiratory infections, especially in newborns and children under 6 years old.

Autocrine activation of PDGFRalpha promotes the progression of ovarian cancer

Platelet-derived growth factor receptor (PDGFR)alpha expression was found in ovarian cancer cells and tumors by microarray hybridization. This led us to test whether ovarian cancers also produce ligands for this receptor, as this would demonstrate that such malignancies support their own growth and spread through autocrine activation. We assayed the expression of ligands for the PDGFR in ovarian tumors, cell lines and peritoneal fluid using RT-PCR, immunohistochemistry (IHC) and ELISA. We detected strong mRNA expression for the PDGFRalpha ligands in most ovarian tumors. Receptor and ligand expressions (PDGFRalpha and PDGF AB) were also detected by IHC in, respectively, 34 and 32 of 47 ovarian tumors. The stainings for PDGFRalpha and PDGF AB were strongly correlated (P-value=0.014), suggesting that an autocrine loop is functional in ovarian cancer. PDGF AA and BB were quantified in peritoneal fluid by ELISA. Both ligands are secreted at higher levels in ovarian cancer ascites specimens (n=54) than in fluid from nonmalignant disorders (n=8). PDGF was detected in media conditioned by ovarian cancer cells. Such conditioned media induced activation of the PDGFR, Akt and MAPK and stimulated cell proliferation. A neutralizing PDGF antibody blocked these effects. Specific PDGFR inhibition by siRNA or a neutralizing antibody to the receptor inhibited PDGF-stimulated receptor activation and cell proliferation, suggesting that receptor targeting has a role in ovarian cancer treatment.

Identification of predictive markers of clinical activity from a phase II trial of single agent pertuzumab (rhuMab 2C4), a HER dimerization inhibitor, in advanced ovarian cancer (OC)

3001

Background: Pertuzumab (P), a humanized HER2 antibody, represents a new class of targeted agents called HER dimerization inhibitors (HDIs). P inhibits dimerization of HER2 with EGFR, HER3 and HER4, and subsequently inhibits signaling through MAP and PI3 kinases. Interim data from a phase II trial suggested that P has activity in OC, especially in a subset of tumors with activated HER2 (Abstract #5051 ASCO 2005). Methods: 123 pts with relapsed OC were treated with P. Cohort 1 was treated with 840mg followed by 420mg and cohort 2 with 1050mg every 3 weeks. Fresh tissue biopsies were mandated from Cohort 1, and archival formalin fixed paraffin tissue (FFPET ) were obtained from both cohorts. Molecular expression studies from FFPET and fresh tissue were conducted. Results: From final data of 117 evaluable pts, 5 pts had objective partial responses (RR = 4.3%). Eight pts (6.8%) had SD for ≥ 6 months, and an additional 4 pts (3.4%) had SD with CA-125 reduction of ≥50%. Overall rate of activity = 14.5%. Of the 65 fresh tumor biopsies, 28 were evaluable and 8 (28.6%) were positive for phosphorylated HER2 (pHER2) by ELISA. Among pts who had pHER2 status determined, TTP was 20.9 weeks for pHER2+ pts (n=8), compared to 5.8 weeks for pHER2- (n = 20). Data from microarray expression profiling were analyzed with respect to pHER2 status from the same tumors. The expression levels of HER2, EGFR and HER3 in combination with the expression of certain HER ligands may be predictive of pHER2 status. We have extended these analyses to qRT-PCR from macrodissected FFPET of HER receptors and ligands. This was analyzed with respect to clinical outcome. Preliminary analyses of expression data suggest that HER receptors and ligands may be promising candidates for diagnostic markers. Updated data in 78 OC pts will be presented. Conclusions: Clinical activity was observed in 14.5% of pts with heavily pretreated OC (PRs, SD ≥ 6 months, and SD with CA-125 reductions of ≥50%). This study suggests that P may be active in OC, and that specific HER receptors and ligands may be promising diagnostics for identifying tumors responsive to P.

[Table: see text]

Clinical activity of imatinib mesylate in combination with docetaxel in patients with advanced, platinum-resistant ovarian cancer—Hoosier Oncology Group GYN03–62

5091

Background: Ovarian tumors harborc-Kit and PDGF receptors. We showed in an in-vitro model that Imatinib (G) inhibits the growth of ovarian cancer cells. We hypothesized that G in combination with chemotherapy inhibits the growth of ovarian tumors. Data from a phase II clinical trial utilizing G in combination with Docetaxel (D) in patients with advanced ovarian cancer (OC) are presented. Methods: This was an open label, one stage, multi-center phase II clinical trial. Planned sample size was 23. Patients with relapsed, platinum-resistant or refractory OC expressing PDGFR or c-kit were eligible. PDGFR and c-kit expression was assessed prior to enrollment by IHC using archival tumor tissue. G was administered at 600mg/d continuously and D was given weekly (30mg/m2) for 4 weeks, with 2 weeks break. Each cycle was 6 weeks, with a maximum of 6 cycles allowed. Tumor assessments were obtained after 2, 4 and 6 cycles. Response rate by RECIST was the primary endpoint. Results: 34 patients were screened. 17 tumors were c-kit + and 25 were PDGFRα +. 23 patients were enrolled. Of those, 4 patients had c-kit+/PDGFR- tumors, 12 were PDGFR+/c-kit- and 7 were c-kit+/PDGFR+. Median age was 55 (range 33–76) and median PS was 0 (range 0–2). Median number of prior treatments was 3 (range 1–9). Efficacy and toxicity data are available for 20 and 14 patients, respectively. Based on RECIST, there were 3 patients with PR and 3 patients with SD lasting at least 12 weeks. Of these 6 patients, 2 pts were c-kit+, 2 were PDGFR+ and 2 were PDGFR and c-kit+. All 6 patients had carboplatin and taxane resistant disease. Grade 3–4 toxicities were: neutropenia (2), thrombocytopenia (1), fatigue (1), dehydration (1), constipation (1), cardiac ischemia (1), nausea/vomiting (2), urinary frequency (1). Other G1–2 toxicities were: N/V (9), diarrhea (7), fatigue (8), mucositis (4), anemia (4), hypocalcemia (5), rash (6), anorexia (7), edema (5), hemolysis (1), non-neutropenic infections (7). Additional data will be available in May 2006. Conclusions: The combination G+D is tolerated well. Clinical activity consisted of 3 PRs (15% response rate) and 3 SD > 3 months in pts with heavily pre-treated, platinum resistant OC expressing c-kit or PDGFRα.

[Table: see text]

Acquired thrombophilic syndromes

As the biochemical mechanisms of hypercoagulable states are revealed, the syndromes of venous thromboembolism have been increasingly associated with specific aberrations. Most of these changes involve an increase in procoagulant potential, for example, by activation of the coagulation cascade, or by a defect or decrease in natural inhibitors of clotting. Similar abnormalities of the fibrinolytic pathways may contribute, as can loss of inhibitory mechanisms of endothelial cells, as well as changes in vascular anatomy and rheologic patterns of blood flow. All of these factors can directly influence thrombus formation and/or the physiologic response to the thrombus.(1)