Trastuzumab-mediated cardiotoxicity in the nontrial setting: Evaluation of patients receiving adjuvant trastuzumab at an academic centre

e11550

Background: Trastuzumab is effective in the treatment of HER-2 positive breast cancer. Although clinical trials have shown an increased risk of cardiotoxicity associated with trastuzumab, this risk has not been well studied in the non-trial setting. This study aims to examine (1) the incidence of cardiotoxicity associated with trastuzumab in the clinical setting (2) the relationship, if any, between risk factors and incidence of cardiotoxicity and (3) cardiac monitoring practices. Methods: A retrospective chart review was conducted of all patients receiving adjuvant trastuzumab therapy between August 2005 and May 2008, at a Canadian academic centre. The incidence of cardiotoxicity, defined as a significant reduction in left ventricular ejection fraction (drop of >10% leading to an ejection fraction of <50%) and/or New York Heart Association class III-IV CHF symptoms requiring trastuzumab delay or discontinuation was evaluated. Medical charts and patient surveys provided demographics, risk factors and cardiac toxicity for each patient. Results: 183 patients were included in the study. The average age of participating patients was 54.8 years and 51% of participants had node positive cancer. 72% were treated sequentially with Trastuzumab and 88% received anthracyclines. The incidence of cardiotoxicity was 6.0% (n=11). Upon univariate analysis, patient age was found to be the only variable significantly associated with the occurrence of cardiotoxicity (OR: 3.55, 95% CI 1.76–90.0). Left ventricular function was monitored by serial MUGA scan every 3.35 ±1.89 months as compared to the 3 month gold standard in clinical trials. Conclusions: In this study the incidence of cardiotoxicity was 6.0%. Patient age was the only significant variable associated with cardiotoxicity, as expected from previous studies. Clinically, this suggests that older patients may need more frequent monitoring for cardiac dysfunction via MUGA and/or ECHO scans. Future research needs to address the relationship between treatment regimens and the incidence of cardiotoxicity. Furthermore, we need to better define cardiotoxicity and the clinical significance of cardiac related symptoms.

No significant financial relationships to disclose.

Measurement of B-->Xgamma decays and determination of |Vtd/Vts|

Using a sample of 383 x 10;{6} BB[over ] events collected by the BABAR experiment, we measure sums of seven exclusive final states B-->X_{d(s)}gamma, where X_{d}(X_{s}) is a nonstrange (strange) charmless hadronic system in the mass range 0.6-1.8 GeV/c;{2}. After correcting for unmeasured decay modes in this mass range, we obtain a branching fraction for b-->dgamma of (7.2+/-2.7(stat)+/-2.3(syst))x10;{-6}. Taking the ratio of X_{d} to X_{s} we find Gamma(b-->dgamma)/Gamma(b-->sgamma)=0.033+/-0.013(stat)+/-0.009(syst), from which we determine |V_{td}/V_{ts}|=0.177+/-0.043.

Improved measurement of B+ --> rho+ rho0 and determination of the quark-mixing phase angle alpha

We present improved measurements of the branching fraction B, the longitudinal polarization fraction f{L}, and the direct CP asymmetry A{CP} in the B meson decay channel B;{+}-->rho;{+}rho;{0}. The data sample was collected with the BABAR detector at SLAC. The results are B(B;{+}-->rho;{+}rho;{0})=(23.7+/-1.4+/-1.4) x 10;{-6}, f{L}=0.950+/-0.015+/-0.006, and A{CP}=-0.054+/-0.055+/-0.010, where the uncertainties are statistical and systematic, respectively. Based on these results, we perform an isospin analysis and determine the Cabibbo-Kobayashi-Maskawa phase angle alpha=arg(-V{td}V{tb};/V{ud}V{ub}) to be (92.4{-6.5};{+6.0}) degrees.

Evidence for X(3872)-->psi(2S)gamma in B(+/-)-->X(3872)K(+/-) decays and a study of B-->cc[over ]gammaK

In a search for B-->cc[over ]gammaK decays with the BABAR detector, where cc[over ] includes J/psi and psi(2S), and K includes K(+/-), K(S)(0), and K(*)(892), we find evidence for X(3872)-->J/psigamma and X(3872)-->psi(2S)gamma with 3.6sigma and 3.5sigma significance, respectively. We measure the product of branching fractions B(B(+/-)-->X(3872)K(+/-))xB(X(3872)-->J/psigamma)=[2.8+/-0.8(stat)+/-0.1(syst)]x10(-6) and B(B(+/-)-->X(3872)K(+/-))xB(X(3872)-->psi(2S)gamma)=[9.5+/-2.7(stat)+/-0.6(syst)]x10(-6).

Direct CP, lepton flavor, and isospin asymmetries in the decays B-->K(*)l+l-

We measure branching fractions and integrated rate asymmetries for the rare decays B-->K(*)l+l-, where l+l- is either e+e- or micro+micro-, using a sample of 384x10(6) BB events collected with the BABAR detector at the PEP-II e+e- collider. We find no evidence for direct CP or lepton-flavor asymmetries. However, for dilepton masses below the J/psi resonance, we find evidence for unexpectedly large isospin asymmetries in both B-->Kl+l- and B-->K*l+l- which differ, respectively, by 3.2sigma and 2.7sigma, including systematic uncertainties, from the standard model expectations.

Social stress alters expression of large conductance calcium-activated potassium channel subunits in mouse adrenal medulla and pituitary glands

Large conductance calcium-activated potassium (BK) channels are very prominently expressed in adrenal chromaffin and many anterior pituitary cells, where they shape intrinsic excitability complexly. Stress- and sex-steroids regulate alternative splicing of Slo-alpha, the pore-forming subunit of BK channels, and chronic behavioural stress has been shown to alter Slo splicing in tree shrew adrenals. In the present study, we focus on mice, measuring the effects of chronic behavioural stress on total mRNA expression of the Slo-alpha gene, two key BK channel beta subunit genes (beta2 and beta4), and the 'STREX' splice variant of Slo-alpha. As a chronic stressor, males of the relatively aggressive SJL strain were housed with a different unfamiliar SJL male every 24 h for 19 days. This 'social-instability' paradigm stressed all individuals, as demonstrated by reduced weight gain and elevated corticosterone levels. Five quantitative reverse transcriptase-polymerase chain assays were performed in parallel, including beta-actin, each calibrated against a dilution series of its corresponding cDNA template. Stress-related changes in BK expression were larger in mice tested at 6 weeks than 9 weeks. In younger animals, Slo-alpha mRNA levels were elevated 44% and 116% in the adrenal medulla and pituitary, respectively, compared to individually-housed controls. beta2 and beta4 mRNAs were elevated 162% and 194% in the pituitary, but slightly reduced in the adrenals of stressed animals. In the pituitary, dominance scores of stressed animals correlated negatively with alpha and beta subunit expression, with more subordinate individuals exhibiting levels that were three- to four-fold higher than controls or dominant individuals. STREX variant representation was lower in the subordinate subset. Thus, the combination of subunits responding to stress differs markedly between adrenal and pituitary glands. These data suggest that early stress will differentially affect neuroendocrine cell excitability, and call for detailed analysis of functional consequences.

Spontaneous resolution of a small extradural haematoma in a child

We report the rapid spontaneous resolution of a small extradural haematoma (EDH) in a 19-month-old child. The haematoma was managed conservatively. The child went on to make a full recovery. The authors discuss the significance of this surprising clinical finding.

Nanoparticle albumin-bound (nab) IDN5404: a novel vascular disrupting agent with potent antitumor and antiangiogenic effects

Abstract #2138

Background: The tumor vasculature is an established target for the therapy of solid tumors. IDN5404 is a thiocolchicine dimer with antitubulin and topisomerase 1 inhibitor properties. In this study, nab-formulated IDN5404 was examined for antitumor effects in three xenograft models and for antiangiogenic as well as vascular disrupting activity (VDA) in the avian embryonic chorioallantoic membrane (CAM) assays.&#x2028; Materials and Methods: Subcutaneous human breast (MX-1 and MDA-MB-231), colon (HT29), and prostate (PC3) tumors were grown in athymic nude mice and treated intravenously (IV) with nab-5404 alone at 10, 20, 30, or 40 mg/kg (q3dx4 or q4dx3) and in combination with IV or intraperitoneal (IP) nab-paclitaxel (Abraxane; 10, 15 or 30 mg/kg, qdx5 or q4dx3). The effect of dose, schedule, and sequence of combination regimen was tested. Nab-5404 was administered 24-hr before, concurrently or 24-hr after Abraxane administration. The effect of nab-5404 on embryonic angiogenesis was examined in vivo using the standard chick CAM assay with 3-day old embryos (n = 18). The quail CAM assay was used to determine the time course of VDA. Quail embryos (n = 36) were exposed to nab-5404 (1 to 16 µg/ml) on day 7 and digital CAM images were acquired over a 60 min period for scoring VDA.&#x2028; Results: Significant dose-dependent tumor growth inhibition (TGI) was observed in all xenograft models. In the MX-1 and HT29 models, nab-5404 (30 mg/kg, q3dx4) exhibited potent antitumor activity (P &lt; 0.0001, ANOVA, vs. saline) alone and in combination with Abraxane (TGI for MX-1: 65% and 76%; TGI for HT29: 44% and 74% respectively). Nab-5404 was similarly effective with the q4dx3 schedule. In addition, when Nab-5404 (20 mg/kg, q4dx3) was administered 24-hr before, concurrently or 24-hr after Abraxane (5 mg/kg, q4dx3), the combination resulted in TGI of &gt;99%, 88%, and 72% respectively. Using the in vivo chick CAM assay, nab-5404 inhibited embryonic angiogenesis by over 90% at 5 µg/CAM without affecting viability. Furthermore, rapid collapse of blood vessels was observed within 30 min in the viable quail CAM assay when embryos were exposed to nab-5404 at 4-16 µg/ml.&#x2028; Discussion: Nab-5404 alone and in combination with Abraxane demonstrated significant TGI in xenograft models of human breast, colon or prostate cancer. This effect was shown to be due to the rapid VDA of nab-5404. Maximum antitumor activity was seen when nab-5404 was administered 24 hr before Abraxane. Nab-5404, a microtubule-destabilizing vascular disruptive agent, potentiates the cytotoxic effects of nab-paclitaxel, a microtubule-stabilizing agent and the data suggest that these two agents may be utilized effectively in combination.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2138.

Decreased cell proliferation of breast cancer cells by genistein is caused by estrogen receptor related signaling molecules

Abstract #6019

Background: Literature reports demonstrate that genistein, a soy phytoestrogen, shows a biphasic response to cell proliferation in breast cancer cells. Genistein increases cell proliferation at low concentrations and decreases cell proliferation at high concentrations. Our previous studies suggest that at low concentrations of genistein the cell proliferative response depends on the type of ER. At high concentrations genistein is believed to act as a tyrosine kinase inhibitor. Currently, the mechanisms of genistein's effect on breast cancer cell proliferation are unclear. The aim of this study was to evaluate the mechanisms of the biphasic response of genistein on breast cancer cell proliferation, specifically by determining the effect of genistein on ER-related cell signaling molecules involved in cell proliferation, cell survival and apoptosis. Based on literature reports, the ER-related cell signaling molecules chosen for this study were ERK1/2, p90RSK, JNK, Akt and NFκB. ERK1/2 and, p90RSK are involved in cell proliferation; JNK, Akt and NFκB are involved in cell survival and/or apoptosis.&#x2028; Methods: The effect of genistein at 1 µM (low concentration) and 100 µM (high concentration) on cell signaling molecules was determined by a BioPlex Phosphoprotein detection kit. Results obtained from the BioPlex assay were confirmed by immunodetection. Cell proliferation was determined at 24, 48, and 72 hrs by the MTT (3-[4,5- dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium) assay. This study was carried out in T47D (ERα and ERβ) and MDA-MB-231 (ERβ) breast cancer cells.&#x2028; Results: At 100 µM genistein exposure we observed a decrease in phosphorylated p90RSK (40%) in T47D cells and an increase in phosphorylated JNK (45%) in MDA-MB-231 cells in a statistically significant (p&lt;0.05) manner. At 100 µM genistein exposure, a statistically significant (p&lt;0.001) decrease in cell proliferation was observed in T47D cells (20-40%) and MDA-MB-231 cells (30-60%) as compared to the control. At 1 µM genistein exposure, there was a statistically significant (p&lt;0.05) decrease (15%) of phosphorylated JNK in MDA-MB-231 cells. MDA-MB-231 cells exposed to 1 µM genistein did not show any statistically significant difference in cell proliferation as compared to the control. T47D cells exposed to 1 µM of genistein for 24 – 72 hours showed a statistically significant (p&lt;0.001) increase (25 to 70%) in cell proliferation.&#x2028; Conclusions: Our data suggests that in T47D cells which have both ERs, decreased cell proliferation due to high concentrations of genistein is probably due to a decrease in phosphorylated p90RSK, an ER-related cell proliferation protein. In MDA-MB-231 cells with only ERβ, the decrease in cell proliferation is probably due to an increase in phosphorylated JNK, an apoptotic protein. Our results suggest that at high concentrations of genistein, the cellular pathways of inhibition of breast cancer cell proliferation likely depend on ER status. This study reveals the importance of genistein as an effective chemotherapeutic agent in breast cancers that contain both ERs and only ERβ.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6019.

Measurement of the e;{+}e;{-}-->bb[over ] Cross Section between sqrt[s]=10.54 and 11.20 GeV

We report e;{+}e;{-}-->bb[over ] cross section measurements by the BABAR experiment performed during an energy scan in the range of 10.54 to 11.20 GeV at the SLAC PEP-II e;{+}e;{-} collider. A total relative error of about 5% is reached in more than 300 center-of-mass energy steps, separated by about 5 MeV. These measurements can be used to derive precise information on the parameters of the Upsilon(10860) and Upsilon(11020) resonances. In particular we show that their widths may be smaller than previously measured.

Anti H.pylori IgM in symptomatic and asymptomatic population

To evaluate the usefulness of specific IgM in the diagnosis of Helicobacter pylori infection, a cross sectional study was carried out in the Department of Microbiology, Mymensingh Medical College between July 2006 to June 2007. A total of 45 patients having upper gastrointestinal symptoms underwent endoscopy and were subsequently diagnosed as patients with gastritis, peptic ulcer (PU) and non-ulcer dyspepsia (NUD) and another 45 asymptomatic individuals aged 18-65 years, were included in the study. The serum samples of participants were tested for presence of anti-H pylori IgM by using ELISA method. The ELISA for anti H. pylori IgM provided sensitivity and specificity of 73.33%, 93.33% respectively.

PCR for mecA gene of methicillin resistant Staphylococcus aureus

The study was under taken to detect mecA gene of methicillin resistant Staphylococcus aureus (MRSA) by PCR. It was carried out in the department of Microbiology, Mymensingh Medical College in collaboration with the Department of Medicine under the Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh between the periods from July 2006 to June 2007. A total of 40 S. aureus strains were used in this study. Isolates of S. aureus were identified by standard microbiology technique and their antimicrobial susceptibility test was done by disk diffusion method according to NCCLS. Minimum inhibitory concentration (MIC) of oxacillin was determined for all isolates by standard agar plate dilution method. All strains were tested for mecA gene by PCR. Out of 40 S. aureus strains 15(37.5%) were detected as MRSA by disk diffusion and agar dilution method but 10(25%) yielded mecA gene by PCR. Detection rate of MRSA by disk diffusion and agar dilution test showed significant difference to that by PCR (p<0.001).

Comparison between DOT EIA IgM and Widal Test as early diagnosis of typhoid fever

A recently developed DOT enzyme immunoassay known as "Typhidot" for detecting IgM antibody against 50 KDa OMP antigen of Salmonella typhi, was evaluated on 100 clinically suspected typhoid fever cases and 40 age-sex matched controls, in the Department of Microbiology, Mymensingh Medical College during, the period from June 2006 to July 2007. Blood culture, Widal test, and DOT EIA for IgM test were performed in all patients. Among 100 clinically suspected typhoid fever cases, 35 were subsequently confirmed on the basis of positive blood culture for S. typhi and/or significant rising titre of Widal test. The DOT EIA IgM test could produce results within 1 hour. The result of the DOT EIA IgM test showed a good diagnostic value for typhoid fever. The sensitivity, specificity, positive and negative predictive value of the test was found as 91.42%, 90.00%, 88.88% and 92.30% respectively. On the other hand corresponding values for Widal test were of 42.85%, 85.00%, 71.42% and 62.96% respectively. Thus, The DOT EIA IgM seems to be a practical alternative to Widal test for early diagnosis of typhoid fever.

Measurement of the branching fractions of B-->D**(l) nu(l) decays in events tagged by a fully reconstructed B meson

We report a measurement of the branching fractions of B-->D**(l) nu(l), decays based on 417 fb(-1) of data collected at the Y(4S) resonance with the BABAR detector at the PEP-II e+e- storage rings. Events are selected by full reconstructing one of the B mesons in a hadronic decay mode. A fit to the invariant mass differences m(D(*) pi)- m(D(*)) is performed to extract the signal yields of the different D** states. We observe the B-->D**l(-1)nu(l) decay modes corresponding to the four D states predicted by heavy quark symmetry with a significance greater than 5 standard deviations including systematic uncertainties.

Searches for B meson decays to phiphi, phirho, phif_{0}(980), and f_{0}(980)f_{0}(980) final states

We present the results of searches for B decays to charmless final states involving varphi, f_{0}(980), and charged or neutral rho mesons. The data sample corresponds to 384x10;{6} BB[over ] pairs collected with the BABAR detector operating at the PEP-II asymmetric-energy e;{+}e;{-} collider at SLAC. We find no significant signals and determine the following 90% confidence level upper limits on the branching fractions, including systematic uncertainties: B(B;{0}-->varphivarphi)<2.0x10;{-7}, B(B;{+}-->varphirho;{+})<30x10;{-7}, B(B;{0}-->varphirho;{0})<3.3x10;{-7}, B[B;{0}-->varphif_{0}(980)]xB[f_{0}(980)-->pi;{+}pi;{-}]<3.8x10;{-7}, and B[B;{0}-->f_{0}(980)f_{0}(980)]xB[f_{0}(980)-->pi;{+}pi;{-}]xB[f_{0}(980)-->K;{+}K;{-}]<2.3x10;{-7}.

Retrieving quantum yield of sun-induced chlorophyll fluorescence near surface from hyperspectral in-situ measurement in productive water

Magnitude and quantum yield (eta) of sun induced chlorophyll fluorescence are determined in widely varying productive waters with chlorophyll concentrations from 2- 200 mg/m(3). Fluorescence was estimated using linear fitting of in-situ measured surface reflectance with elastic and inelastic reflectance spectra. Elastic reflectance spectra were obtained from Hydrolight simulations with measured absorption and attenuation spectra as inputs. Eta is then computed based on a depth integrated fluorescence model and compared with Hydrolight calculation results. Despite the large variability of coastal environments examined the ? values are found to vary over a relatively narrow range 0.1%-1% with mean values of 0.33%+/-0.17%.

Measurement of the CP asymmetry in b-->sgamma using a sum of exclusive final states

We perform a measurement of the CP asymmetry in b-->sgamma decays using a sample of 383 x 10(6) B[over] B events collected by the BABAR detector at the SLAC PEP-II asymmetric B factory. We reconstruct 16 flavor-specific B decay modes containing a high-energy photon and a hadronic system X_(s) containing an s quark. We measure the CP asymmetry to be -0.011+/-0.030(stat)+/-0.014(syst) for a hadronic system mass between 0.6 and 2.8 GeV/c(2).