Modeling evolution of resistance by Maruca vitrata (Lepidoptera: Crambidae) to transgenic insecticidal cowpea in Africa

We created a detailed model of the Maruca vitrata (F.) and cowpea [Vigna unguiculata (L.) Walp] system to study the possible evolution of resistance by the insect to transgenic insecticidal cowpea, which is under development. We focused on population dynamics and genetics in a region of west Africa. We simulated single-toxin and pyramided (two-toxin) cowpea and emphasized conservative, worst-case scenarios in our analysis. The results indicate that as long as a pyramided, transgenic cowpea can be developed, seed saving by farmers and reliance on natural refuge are not major problems for resistance management. Furthermore, it is possible that one or both toxins in the pyramid may not need to be high dose for evolution to be delayed significantly (>20 yr or 80 generations for resistance to become a concern if transgenic cowpea is deployed in areas where M. vitrata is endemic). If efforts are made to deploy transgenic cowpea only into the regions where M. vitrata is not endemic, then there is little to no concern with resistance emerging in the M. vitrata population.

A randomized, prospective, two-center comparison of sirolimus-eluting stent and zotarolimus-eluting stent in acute ST-elevation myocardial infarction: the SEZE trial

BACKGROUND

The zotarolimus-eluting stent has shown larger in-stent late lumen loss compared to sirolimus-eluting stents in previous studies. However, this has not been thoroughly evaluated in ST elevation myocardial infarction.

METHODS

This was a prospective, randomized, controlled trial evaluating angiographic outcomes in patients presenting with ST elevation myocardial infarction, treated with zotarolimus-eluting stents or sirolimus-eluting stents. From March 2007 to February 2009, 122 patients were randomized to zotarolimus-eluting stents or sirolimus-eluting stents in a 1:1 fashion. The primary endpoint was 9-month in-stent late lumen loss confirmed by coronary angiography, and secondary endpoints were percent diameter stenosis, binary restenosis rate, major adverse cardiac events (a composite of cardiac death, non-fatal myocardial infarction, and target vessel revascularization), and late-acquired incomplete stent apposition.

RESULTS

Angiographic in-stent late lumen loss was significantly higher in the zotarolimus-eluting stent group compared to the sirolimus-eluting stent group ((0.49 ± 0.65) mm vs. (0.10 ± 0.46) mm, P = 0.001). Percent diameter stenosis at 9-month follow-up was also larger in the zotarolimus-eluting stent group ((30.0 ± 17.9)% vs. (17.6 ± 14.0)%, P < 0.001). In-segment analysis showed similar findings. There were no significant differences in binary restenosis rate, major adverse cardiac events, and late-acquired incomplete stent apposition.

CONCLUSIONS

Compared to sirolimus-eluting stents, the zotarolimus-eluting stent is associated with significantly higher in-stent late lumen loss at 9-month angiographic follow-up in the treatment of ST elevation myocardial infarction. Although there was no significant difference in 1-year clinical outcomes, the clinical implication of increased late lumen loss should be further studied.

Cereblon is a direct protein target for immunomodulatory and antiproliferative activities of lenalidomide and pomalidomide

Thalidomide and the immunomodulatory drug, lenalidomide, are therapeutically active in hematological malignancies. The ubiquitously expressed E3 ligase protein cereblon (CRBN) has been identified as the primary teratogenic target of thalidomide. Our studies demonstrate that thalidomide, lenalidomide and another immunomodulatory drug, pomalidomide, bound endogenous CRBN and recombinant CRBN–DNA damage binding protein-1 (DDB1) complexes. CRBN mediated antiproliferative activities of lenalidomide and pomalidomide in myeloma cells, as well as lenalidomide- and pomalidomide-induced cytokine production in T cells. Lenalidomide and pomalidomide inhibited autoubiquitination of CRBN in HEK293T cells expressing thalidomide-binding competent wild-type CRBN, but not thalidomide-binding defective CRBN^YW/AA. Overexpression of CRBN wild-type protein, but not CRBN^YW/AA mutant protein, in KMS12 myeloma cells, amplified pomalidomide-mediated reductions in c-myc and IRF4 expression and increases in p21^WAF-1 expression. Long-term selection for lenalidomide resistance in H929 myeloma cell lines was accompanied by a reduction in CRBN, while in DF15R myeloma cells resistant to both pomalidomide and lenalidomide, CRBN protein was undetectable. Our biophysical, biochemical and gene silencing studies show that CRBN is a proximate, therapeutically important molecular target of lenalidomide and pomalidomide.

Friedel-like oscillations from interstitial iron in superconducting Fe(1+y)Te0.62Se0.38

Using polarized and unpolarized neutron scattering, we show that interstitial Fe in superconducting Fe(1+y)Te(1-x)Se(x) induces a magnetic Friedel-like oscillation that diffracts at Q⊥=(1/2 0) and involves >50 neighboring Fe sites. The interstitial >2μ(B) moment is surrounded by compensating ferromagnetic four-spin clusters that may seed double stripe ordering in Fe(1+y)Te. A semimetallic five-band model with (1/2 1/2) Fermi surface nesting and fourfold symmetric superexchange between interstitial Fe and two in-plane nearest neighbors largely accounts for the observed diffraction.

Modeling the impact of cross-pollination and low toxin expression in corn kernels on adaptation of European corn borer (Lepidoptera: Crambidae) to transgenic insecticidal corn

We used a mathematical model with processes reflecting larval mortality resulting from feeding on cross-pollinated ears or Bt ears of corn to analyze the risk of evolution of Cry-toxin resistance in Ostrinia nubilalis (Hübner). In the simulations, evolution of resistance was delayed equally well by both seed mixtures and blocks with the same proportion of refuge. Our results showed that Bt-pollen drift has little impact on the evolution of Bt resistance in O. nubilalis. However, low-toxin expression in ears of transgenic corn can reduce the durability of transgenic corn expressing single toxin, whereas durability of pyramided corn hybrids is not significantly reduced. The toxin-survival rate of heterozygous larvae in Bt-corn ears expressing one or two proteins has more impact on evolution of Bt resistance in O. nubilalis than the parameters related to larval movement to Bt ears or the toxin-survival rate of the homozygous susceptible larvae in Bt ears. Bt resistance evolves slower when toxin mortality is distributed across the first two larval stadia than when only the first instars are susceptible to Bt toxins. We suggest that stakeholders examine toxin-survival rates for insect pests and take into account that instars may feed on different parts of Bt corn.

The influence of 9-cis-retinoic acid on nuclear and cytoplasmic maturation and gene expression in canine oocytes during in vitro maturation

Retinoids have important roles in regulation of oocyte nuclear and cytoplasmic maturation. The present study investigated the effects of a retinoid metabolite on nuclear maturation, cytoplasmic maturation, and gene expression in canine oocytes during in vitro maturation (IVM). Cumulus-oocyte complexes (COCs) were harvested from ovaries by slicing. Only oocytes that were >120 μm in diameter, with a homogeneous dark cytoplasm and three or more layers of compact cumulus cells were used. Varying concentrations of 9-cis retinoic acid (9-cis-RA; 0, 5, 50, and 500 nm) were included in the maturation medium, and the following were measured: (i) oocyte nuclear maturation after culture for 48 h; (ii) cytoplasmic granular migration by labeling of oocytes with fluorescein isothiocyanate labeled lectins; and (iii) relative expression of genes related to apoptosis (BAX and BclII) in cumulus cells detached from oocytes, by semiquantitative reverse transcriptase-polymerase chain reaction. After 48 h culture with IVM, the highest percentage of oocytes that had developed to the metaphase II (MII) stage were in the 5 nm 9-cis-RA treatment group (18.3 ± 2.5%; P < 0.05). Complete granular migration was observed in oocytes matured with 5 nm 9-cis-RA, consistent with a commensurate gain in developmental competence. Treatment with 5 nm 9-cis-RA had no effect on BclII gene expression, but downregulated BAX expression. In conclusion, since 5 nm 9-cis-RA was beneficial to nuclear and cytoplasmic maturation of canine oocytes, we inferred an important role for 9-cis-RA during IVM.