Measurement of Compton scattering from the deuteron and an improved extraction of the neutron electromagnetic polarizabilities

The electromagnetic polarizabilities of the nucleon are fundamental properties that describe its response to external electric and magnetic fields. They can be extracted from Compton-scattering data-and have been, with good accuracy, in the case of the proton. In contradistinction, information for the neutron requires the use of Compton scattering from nuclear targets. Here, we report a new measurement of elastic photon scattering from deuterium using quasimonoenergetic tagged photons at the MAX IV Laboratory in Lund, Sweden. These first new data in more than a decade effectively double the world data set. Their energy range overlaps with previous experiments and extends it by 20 MeV to higher energies. An analysis using chiral effective field theory with dynamical Δ(1232) degrees of freedom shows the data are consistent with and within the world data set. After demonstrating that the fit is consistent with the Baldin sum rule, extracting values for the isoscalar nucleon polarizabilities, and combining them with a recent result for the proton, we obtain the neutron polarizabilities as αn=[11.55±1.25(stat)±0.2(BSR)±0.8(th)]×10(-4)  fm(3) and βn=[3.65∓1.25(stat)±0.2(BSR)∓0.8(th)]×10(-4)  fm(3), with χ(2)=45.2 for 44 degrees of freedom.

Cooling dynamics of photoexcited C6(-) and C6H(-)

We report conclusive evidence of an efficient cooling mechanism via the electronic radiative transitions of hot small molecular anions isolated in vacuum. We stored C6(-) and C6H(-) in an ion storage ring and observed laser-induced electron detachment with delays up to several milliseconds. The terminal hydrogen atom caused a drastic change in the decay profiles. The decay of photoexcited C6H(-) is slow and nonexponential, which can be explained by depletion cooling, whereas that for C6(-) occurs extremely fast, on a time scale below 0.1 ms and can only be explained by electronic radiative cooling via low-lying electronic excited states.

First storage of ion beams in the Double Electrostatic Ion-Ring Experiment: DESIREE

We report on the first storage of ion beams in the Double ElectroStatic Ion Ring ExpEriment, DESIREE, at Stockholm University. We have produced beams of atomic carbon anions and small carbon anion molecules (C(n)(-), n = 1, 2, 3, 4) in a sputter ion source. The ion beams were accelerated to 10 keV kinetic energy and stored in an electrostatic ion storage ring enclosed in a vacuum chamber at 13 K. For 10 keV C2 (-) molecular anions we measure the residual-gas limited beam storage lifetime to be 448 s ± 18 s with two independent detector systems. Using the measured storage lifetimes we estimate that the residual gas pressure is in the 10(-14) mbar range. When high current ion beams are injected, the number of stored particles does not follow a single exponential decay law as would be expected for stored particles lost solely due to electron detachment in collision with the residual-gas. Instead, we observe a faster initial decay rate, which we ascribe to the effect of the space charge of the ion beam on the storage capacity.

Update on acute endovascular and surgical stroke treatment

Emergency stroke care has become a natural part of the emerging discipline of neurocritical care and demands close cooperation between the neurologist and neurointerventionists, neurosurgeons, and anesthesiologists. Endovascular treatment (EVT), including intra-arterial thrombolysis, mechanical thrombectomy and angioplasty/stenting, is under rapid development. Although EVT has yet to be shown in randomized controlled trials to improve clinical outcome compared to intravenous thrombolysis, it is far better in achieving recanalization of occluded large cerebral vessels, which is crucial for rescuing the penumbra. Moreover, decompressive craniectomy is now a well-established treatment option for malignant middle cerebral artery infarction and cerebellar stroke. Using a case-based approach, this article reviews recent achievements in advanced treatment options for patients with acute ischemic stroke.

Proteolytic cleavage of recombinant two-chain factor VIII during cell culture production is mediated by protease(s) from lysed cells. The use of pulse labelling directly in production medium

During the production by mammalian cells of recombinant factor VIII from which the B domain was deleted (rFVIII), proteolytic cleavages in the C-terminal part of the heavy chain were observed (Kjalke et al., 1995). By radioactive pulse labelling it was investigated whether the cleavages took place inside the cells during protein synthesis or after release in the medium. The rFVIII-producing CHO (Chinese hamster ovary) cells were cultured in the presence of (35)S-methionine and then the cell lysate and the conditioned media were immunoprecipitated and analyzed by electrophoresis. By pulse labelling and chasing for various time periods, it was shown that the cleavages only took place after secretion of the protein from the cells. Adding cell lysate to uncleaved rFVIII caused cleavage of the heavy chain, as seen by loss of binding to a monoclonal antibody specific for intact rFVIII, indicating that the cleavage was performed by proteinase(s) released from the lysed cells. By incubating intact rFVIII with the multicatalytic proteinase (proteasome) present in cytoplasm and nucleus of eukaryotic cells, loss of binding to the monoclonal antibody was observed. This indicates that the multicatalytic proteinase, released from lysed rFVIII producing cells, could be responsible for the cleavage of rFVIII. Among several protease inhibitors tested, only bacitracin was found to diminish the extent of cleavage. Phosphatidylserine also protected rFVIII against cleavage, probably by binding to rFVIII.

Lipolysis in early lactation is associated with an increase in phosphorylation of adenosine monophosphate-activated protein kinase (AMPK)α1 in adipose tissue of dairy cows

Adenosine monophosphate-activated protein kinase (AMPK)α1 is activated in the context of triacylglycerol hydrolysis in adipose tissue in monogastric animals. This study describes AMPKα1 protein expression and the occurrence of its phosphorylated form (pAMPKα1) in different adipose tissue depots as influenced by time and postpartum diet in dairy cows. Biopsy samples were obtained from subcutaneous (SCAT) and retroperitoneal (RPAT) adipose tissues of 20 Holstein cows 21 d prepartum (ap) and 1 and 21 d postpartum (pp). After d 1 pp, cows were randomly assigned to 2 groups (n=10) and fed different amounts of concentrate until the third biopsy sampling at 21 d pp. Protein expression of AMPK and the extent of its phosphorylation in adipose tissue were measured by semiquantitative Western blotting. Results were not influenced by postpartum feeding. Therefore, both groups were pooled and data analyzed together. Expression of AMPKα1 in SCAT showed a decrease over time, resulting in lower expression at 1d pp compared with 21 d ap. Expression in RPAT was maintained over time. Phosphorylation increased in SCAT, showing a greater extent of phosphorylation at d 21 pp compared with 21 d ap. In RPAT, this could be seen as a trend. The proportion of pAMPKα1 to AMPKα1 significantly increased over time in both tissues. In the first adipose tissue sampling (21 d ap), AMPKα1 protein expression and extent of phosphorylation were significantly higher in RPAT than in SCAT. Lipolysis in early lactation of dairy cows was associated with an increase in phosphorylation of AMPKα1 and ratio of pAMPKα1 to AMPKα1 in bovine adipose tissues. This indicates that AMPKα1 may be involved in the regulation of energy metabolism of bovine adipose tissues.

Anisotropic hot electron emission from fullerenes

Photoelectron spectra for fullerenes C(60) and C(70) ionized using 800 nm laser pulses with pulse durations from 120 to 1000 fs show thermal electron kinetic energy distributions but they also exhibit angular anisotropy with respect to the laser light polarization. The effective temperature of electrons, measured along the laser polarization direction, is significantly higher than in the perpendicular direction. We explain this observation by considering that the emission of the thermal electrons is uncorrelated with the phase of the laser pulse, unlike directly ionized electrons, and, depending on the time of emission, they may experience an additional "kick" from the vector potential of the laser field when they are emitted from the molecule.

P5-19-05: Age-Related Changes in the Pharmacokinetics (pK), Response, and Toxicity of Weekly nab-Paclitaxel in Patients with Metastatic Breast Cancer (MBC)

Background: Although cancer is a disease of aging, few studies have evaluated the association between patient age and the pK or pharmacodynamics (pD) of cancer therapeutics. The goals of this study were 1) to evaluate the age-related changes in the pK and pD of weekly nab-paclitaxel in patients with MBC; 2) to determine response rate; and 3) to explore the relationship of age with pK and pD parameters (i.e., dose reductions, dose delays and grade ≥ 3 toxicities). Patients and Methods: Forty patients with MBC, receiving 1st or 2nd line chemotherapy, entered an IRB approved protocol to evaluate the age-related changes in the pK of weekly nab-paclitaxel administered at 100 mg/m2 IV for 3 weeks followed by a 1-week break. Patients were accrued from 4 age strata <50, 50–60, 60–70, and >70 years of age. Blood samples were collected for pK analysis with the first dose of nab-paclitaxel. Response was assessed every 2 cycles. Toxicity was graded using the NCI Common Toxicity Criteria for Adverse Events (v 3.0) and was adjudicated as attributable to nab-paclitaxel if it was possibly, probably, or definitely related. Linear regression analysis was used to examine the strength of the relationship between patient age and natural logarithm of 24 hour area under the curve (AUC). Two-sided two-sample t-tests were used to assess if there was a difference in mean age based on the presence of pD variables (i.e., dose reductions, dose delays and grade ≥ 3 toxicities). The significance level was set to 0.05.

Results: Of the 40 patients who entered the study, 39 (98%) were evaluable with a mean age of 60 (SD=13.4; min=30; max=81). Patients were accrued in the following age cohorts: <50 (n= 10; 26%), 50–60 (n= 5; 13%), 60–70 (n= 15; 38%), and >70 (n= 9; 23%) years of age. The median number of courses completed was 4 (min=1, max=21). The response rate was: 0% (n=0) CR, 31% (n=12) PR, 38% (n=15) SD. Grade 3 toxicity was experienced by 26% (n=10). We observed 8% (n=3) grade 3 hematological toxicities [neutrophils (n=1; 3%), leukocytes (n=2; 5%)] and 18% (n=7) grade 3 non-hematological toxicities [nausea and hypophosphatemia (n=1; 3%), diarrhea and infection without neutropenia (n=1; 3%), fatigue (n=2; 5%), hyponatremia (n=1; 3%), and infections without neutropenia (n=2; 5%)]. There were no cases of grade 4 or 5 toxicity. Grade 2 sensory neuropathy was experienced by 8% (n=3; no cases in the 70+ age cohort). Dose reductions or course delays were experienced by 62% (n=24) and 21% (n=8), respectively. There was a borderline significant positive association between age and natural logarithm of total nab-paclitaxel 24 hour AUC (coef=.01; se=.006; p=0.055; n=36). There were no differences in the mean ages based on the presence of grade 3 or higher toxicity (p =0.75), need for dose reductions (p=0.48), or need for dose delays (p=0.61).

Discussion: There is a borderline statistically significant relationship between age and 24 hour AUC but no differences in mean age based on pD variables (i.e., dose reductions, dose delays and grade ≥ 3 toxicities) were identified. The treatment is well-tolerated across all age groups.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-19-05.

BS3-2: Mammary Stroma as an NSAID Target; Implications for Pregnancy-Associated Breast Cancer

Utilizing a young women's breast cancer cohort from the University of Colorado Cancer Center, we show that women diagnosed as late as five-ten years postpartum have worse prognosis than nulliparous women or women diagnosed during pregnancy, and represent ∼50% of all young women's breast cancer patients. We propose that breast involution following pregnancy accounts for this poor prognosis. Characterization of involution identifies tissue remodeling programs that share similarities with microenvironments known to promote metastasis. Using SHG imaging, we find fibrillar collagen bundles with radially-aligned fibers similar to those observed in invasive tumors deposited in the involuting gland. By immunohistochemistry and FACS we find macrophages with an M2-polarization-like profile similar to tumor-associated macrophages at abundant levels during involution. In three independent mouse models for postpartum breast cancer, we isolate postpartum mammary gland involution as a driving force for cancer progression. Mammary tumors arising in the mouse involuting microenvironment express COX-2 and isolated tumor cells are motile and invasive in a collagen-1/COX-2 dependent manner. Targeting involution-macrophages as likely mediators of tumor promotion was accomplished using a previously described mouse transgenic model. Macrophage depletion during involution had catastrophic effects on normal mammary gland involution. Conversely, inhibition of COX-2 with celecoxib, aspirin or ibuprofen did not interfere with postpartum lobular regression. COX-2 inhibition did decrease tumor growth, local tumor cell dispersion and lung metastasis. NSAID treatment also suppressed collagen and tenascin-C deposition in the involuting microenvironment, suggesting that modulation of extracellular matrix proteins may be a novel mechanism by which NSAIDs exhibit chemopreventive activity. Our studies indicate two distinct roles for COX-2 in the postpartum setting. COX-2 activity within the tumor cell is required for invasiveness and COX-2 activity in the host promotes collagen fibrillogenesis. Several correlative observations implicate the collagen/COX-2 pathway in postpartum breast cancer in women: involuting breast tissue has increased collagen with radially aligned fibers, analysis of 11 publically available microarray data sets shows high COL1A and COX-2 independently correlate with decreased relapse free-survival in young breast cancer patients, and COX-2 protein is observed in DCIS lesions in postpartum cases at higher levels than nulliparous cases.

In summary, our studies suggest further research into COX-2 inhibitor use might provide a novel strategy to improve the prognosis of young women should they be diagnosed with postpartum breast cancer. The question of whether an NSAID based intervention study could be aimed at recently pregnant women at high risk for breast cancer also remains to be determined, but is an extremely desirable objective given that the ∼ 6 million pregnancies in the US per year.

Supported by grants from DoD Synergistic Idea Awards BC060531 & BC10400/001, Komen Foundation KG090629, DoD Idea Award BC074970 to PJK, ACS New England Division Postdoctoral Fellowship Spin Odyssey PF-08-257-01-CSM to TRL and DoD Predoctoral Grants BC073482 to JO and BC100910 to HM.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr BS3-2.

Scent organ development in creatonotos moths: regulation by pyrrolizidine alkaloids

7-Hydroxy-6,7-dihydro-5H-pyrolizine-1-carboxaldehyde is the major volatile component of the scent organs in males of two species of Creatonotos (Lepidoptera, Arctiidae). The biosynthesis of this presumed pheromone depends on the presence of pyrrolizidine alkaloids in plants that are ingested by the larvae. In addition, these secondary plant substances control the morphogenesis of the scent organs. This morphogenetic effect of an alkaloid has not been observed previously.

Absolute cooling rates of freely decaying fullerenes

The cooling rates of C60- have been measured in an electrostatic storage ring between several hundred mus and several tens of ms with one-photon laser excitation. The absolute energy scale is established by the photon energy, and the cooling time interval is derived from the nonexponential decay of the ensemble of hot molecules. The energy decreases due to the combined action of depletion and thermal emission of IR photons with a total energy loss rate that varies inversely proportional to time, 0.9 eV/t. The radiative component decreases from a few hundred eV/s at submillisecond time scales to several tens of eV/s at 20 ms and confirms that the crossover from depletion to predominantly radiative cooling occurs around 5 ms. The method is applicable to any large molecule or cluster which decays spontaneously, irrespective of the specific decay channel.