Enhanced immunogenicity and antitumour effects with heterologous prime-boost regime using vaccines based on MG7-Ag mimotope of gastric cancer

MG7-Ag, gastric cancer-associated antigen, has been shown to be immunogenic and has been used as marker molecule for prognosis. In a previous study, we developed an oral DNA vaccine based on MG7-Ag mimotope. However, we failed to detect cellular immune response using the oral MG7-Ag mimotope DNA vaccine. To induce significant T cell response, we developed a recombinant adenovirus vaccine based on MG7-Ag mimotope and evaluated the efficacy and protective effects of heterologous prime-boost immunization protocol with an oral DNA vaccine previously developed. We found that both vaccines were able to elicit a significant humoral response against MG7-Ag, while the highest serum titre MG7 antibody was detected in mice immunized with the heterologous prime-boost immunization protocol. Enzyme-linked immunospot (ELISPOT) assay demonstrated that the heterologous prime-boost immunization strategy was more efficient in inducing T cell response than the homologous prime-boost strategy. In the tumour challenge assay, 2 of 5 mice immunized with the heterologous prime-boost protocol were tumour free, while none of the mice in homologous prime-boost groups or control groups was tumour free. Those tumour-bearing mice in the heterologous prime-boost regime had smaller tumour masses than their counterparts in the homologous prime-boost groups or control groups. Therefore, our study suggests that vaccines against MG7-Ag induce significant immune response against gastric cancer, and that the heterologous prime-boost protocol using different types of vaccines could achieve better protective effect than the homologous prime-boost protocol.

Search for the rare decay B0-->tau+tau- at BABAR

We present the results of a search for the decay B0-->tau+tau- in a data sample of (232+/-3)x10(6) Upsilon(4S)-->BB decays using the BABAR detector. Certain extensions of the standard model predict measurable levels of this otherwise rare decay. We reconstruct fully one neutral B meson and seek evidence for the signal decay in the rest of the event. We find no evidence for signal events and obtain Beta(B0->tau+tau-)<4.1x10(-3) at the 90% confidence level.

Increased risk of thrombosis with lenalidomide in combination with dexamethasone and erythropoietin

7506

Background: Lenalidomide (Len) is a novel, orally administered, immunomodulatory drug (IMiD) that has single-agent activity against multiple myeloma (MM) and additive effects when combined with dexamethasone (Dex). At the interim analysis of MM-009/010, lenalidomide/dexamethasone achieved a significant benefit over dexamethasone, providing a longer median time to progression (TTP), higher response rates, and higher CR rates. Aim: This subgroup analysis of MM-009/010 was performed to evaluate thrombosis in patients receiving Len/Dex vs Dex. Thrombotic events included the following adverse event terms: thrombosis, deep venous thrombosis, thromboembolism, and pulmonary embolism. Methods: Patients (pts) with relapsed or refractory MM were randomized to either receive oral Len (25 mg daily for 3 weeks every 4 weeks) plus Dex (40 mg on Days 1–4, 9–12, 17–20 every 4 weeks for 4 months, then 40 mg on Days 1–4 every cycle thereafter) or placebo plus Dex. Results: Thrombotic events were reported in 39 (11.3%) of 346 pts treated with Len/Dex compared to 13 (3.8%) of 346 pts treated with Dex alone (p < 0.001). Multivariate analysis identified Len/Dex treatment and erythropoietic treatment to be independently correlated with thrombosis (Table). Older age, lower plasma cell percentage in marrow, and better ECOG performance status had a weaker association with thrombosis. Thrombosis occurred more frequently among pts with prior history of thrombosis, although that was not a significant predictor in the multivariate anlaysis. None of 23 pts who used aspirin or salicylate during the first month of treatment developed thrombosis and all events occurred in pts with rising M-paraprotein levels at baseline. Conclusions: The current study findings suggest that the administration of erythropoietic agents should be minimized in MM pts receiving Len/Dex. Prophylactic antithrombotic therapy should also be considered.

[Table: see text]

[Table: see text]

Lenalidomide plus high-dose dexamethasone provides improved overall survival compared to high-dose dexamethasone alone for relapsed or refractory multiple myeloma (MM): Results of a North American phase III study (MM-009)

7521

Background: Lenalidomide is a novel, orally administered, immunomodulatory drug (IMiD) that has single-agent activity against MM and additive effects when combined with dexamethasone (Dex). Methods: In this phase 3, multicenter, double-blind trial, 354 patients (pts)with relapsed or refractory MM were treated with Dex 40 mg daily on days 1–4, 9–12, 17–20 every 28 days and were randomized to receive either lenalidomide (Len) 25 mg daily orally on days 1–21 every 28 days or placebo. Beginning with cycle 5, Dex was reduced to 40 mg daily on days 1–4 only, every 28 days. Patients were stratified with respect to B2M (≤ 2.5 vs. > 2.5 mg/mL), prior stem cell transplant (none vs. ≥ 1), and number of prior regimens (1 vs > 1). The treatment arms were well balanced for prognostic features. Results: The overall response rate was greater with Len-Dex than with Dex-placebo (59.4% vs. 21.1%; p < 0.001). Complete responses were achieved in 12.9% of pts treated with Len-Dex and 0.6% of pts treated with Dex-placebo. The median time to progression (TTP) for pts treated with Len-Dex was 11.1 months compared to 4.7 months for pts treated with Dex-placebo (p < 0.000001). Median overall survival was higher with Len-Dex (not reached) compared to Dex-placebo (24 months) (hazard ratio 1.76, p = .0125). Grade 3–4 neutropenia was more frequent with combination therapy than with Dex-placebo (24% vs. 3.5%), however ≥ grade 3 infections were similar in both groups. Thromboembolic events occurred in 15% of pts treated with Len-Dex and in 3.5% of pts treated with Dex-placebo. Atrial fibrillation occurred in 8 pts and CHF developed in 4 pts treated with Len-Dex. Conclusions: Considering the ease of oral administration, higher response rate, longer time to progression and overall survival benefit, the combination of lenalidomide-dexamethasone may very well represent the treatment of choice for early refractory or relapsing multiple myeloma. The relatively infrequent side effects should not detract from these improvements, but the use of prophylactic antithrombotic therapy should be considered for patients treated with the combination of lenalidomide and dexamethasone.

[Table: see text]

A multicenter, randomized, double-blind, placebo-controlled trial of thalidomide plus dexamethasone versus dexamethasone alone as initial therapy for newly diagnosed multiple myeloma

7517

Background: Thalidomide plus dexamethasone (Thal/Dex) yields superior response rates versus dexamethasone (Dex) but its impact as primary therapy for multiple myeloma (MM) is unknown. Methods: Patients (pts) with previously untreated, symptomatic MM were eligible and were randomized in this double-blind trial to Thal/Dex (Arm A) or placebo plus Dex (Arm B). Pts in Arm A received Thal 50 mg PO daily, escalated to 100 mg on day 15, and to 200 mg from day 1 of cycle 2; Dex 40 mg PO was given on days 1–4, 9–12, and 17–20. Pts in Arm B received placebo instead of Thal, and Dex as in Arm A. Cycles were 28 days long, repeated until progression or undue toxicity. The primary endpoint was time to progression (TTP) defined using EBMT criteria. All analyses were intent to treat. Planned sample size was 218 eligible pts in each arm. Full information for one-sided log rank test with significance level of 0.025 (allowing for 1interim analysis) to have 80% power to detect a 40% improvement in TTP (16.8 mo in Arm A vs. 12 mo in Arm B) would be achieved when 282 pts have progressed. A pre-planned interim analysis of the primary endpoint and safety was performed by an independent Data Monitoring Committee (DMC). P value < 0.0015 at this interim analysis would indicate that Arm A is superior to Arm B based on an alpha-spending function of the O’Brien-Fleming type. The DMC recommended release of results. Results: 470 pts were enrolled: 235 randomized to Thal/Dex and 235 to placebo/Dex. Median follow-up was 25 months. Median age was 65 yrs. TTP was significantly superior with Thal/Dex vs placebo/Dex, median TTP 17.4 months (95% CI: 8.1 months-NE) vs 6.4 months (95% CI: 5.6–7.4 months), respectively, P < 0.000065, crossing the upper boundary for superiority. DVT was higher with Thal/Dex vs placebo/Dex, 15.4% vs 4.3%, respectively. Median survival was not reached in either arm. Conclusions: Thal/Dex is significantly superior to Dex alone as first-line therapy for multiple myeloma.

[Table: see text]

[Table: see text]

Comparison of lenalidomide in combination with dexamethasone to dexamethasone alone in patients who have received prior thalidomide in relapsed or refractory multiple myeloma

7522

Background: Lenalidomide (len), an analog of thalidomide (thal) is a novel, oral immunomodulatory agent that is effective against multiple myeloma (MM). Two randomized, Phase III trials (MM009 and MM010) have recently demonstrated superior responses and overall survival (OS) for patients (pts) treated with len and dexamethasone (dex) in comparison with dex-placebo. This is a prospective subgroup analysis to assess the impact of prior therapy with thal on the sensitivity of MM to subsequent lenalidomide. Methods: We evaluated 692 pts from both trials (MM009 and MM010). The pts had relapsed/refractory MM, were not refractory to dex and were randomized to receive either len (25 mg daily for 3 weeks (wks) every 4 wks) plus dex (40 mg on days 1–4, 9–12, 17–20 every 4 wks for 4 cycles, then 40 mg on days 1–4 every subsequent cycle) or placebo plus dex. Standard criteria were used to evaluate response and TTP. Results: Pooled data from 692 pts showed superior median TTP (48.1 vs 20.1 wks) and OR (59.2% vs 22.5%) in pts treated with len/dex compared to dex-placebo (p <0.001). Although subgroup analysis of pts with prior thal therapy revealed that pts who received len/dex had significantly improved OR, PR CR and median TTP than pts who received dex-placebo, OR, CR and TTP were highest in len/dex pts not previously treated with thal. Multivariate analysis indicates that after controlling for the treatment factor and baseline disease characteristics, whether or not pt had prior exposure to thal is a marginally significant variable to predict TTP. The risk of deep venous thrombosis and pulmonary embolism in these subgroups will be updated on further analysis. Conclusions: Lenalidomide in combination with dexamethasone is more effective than dexamethasone-placebo regardless of prior thalidomide in relapsed/refractory multiple myeloma.

[Table: see text]

[Table: see text]

Lenalidomide (Len) in combination with dexamethasone (Dex) is more effective than Dex alone at first relapse and provides better outcomes when used early rather than as later salvage therapy in relapsed multiple myeloma (MM)

7600

Background: High-dose Dex remains a standard therapy for relapsed or refractory MM. Lenalidomide is a novel, oral, immunomodulatory drug (IMiD) that has activity against MM with additive effects when combined with Dex. At the interim analysis of MM-009/010, Len/Dex achieved a significant benefit over Dex, providing a longer median TTP, higher response rates, and higher CR rates. Aim: This prospective subgroup analysis was performed to determine the potential benefit of starting Len/Dex at first relapse by analyzing outcomes versus Dex among patients (pts) who had received only 1 versus >1 prior line of therapy. Methods: Pts who had received 1–3 prior treatments and were not refractory to Dex were randomized to either oral lenalidomide (25 mg daily for 3 weeks every 4 weeks) plus Dex (40 mg on Days 1–4, 9–12, 17–20 every 4 weeks for 4 months, then 40 mg on Days 1–4 every cycle thereafter) or placebo plus Dex. The EBMT criteria were used for response. Randomization was stratified at entry by number of prior therapies (1 versus > 1). Results: Of 692 randomized pts, 241 pts (34%) received only 1 prior therapy. Those receiving 2nd-line Len/Dex had a significantly longer median TTP (66 vs. 20 wks) and a higher RR (CR + PR); (63% vs. 26%) versus those receiving 2nd-line Dex. After a median follow-up of 12.1 mos for all pts, 2nd-line Len/Dex provided significantly improved overall survival (OS) (hazard ratio 1.85, P = 0.03) versus 2nd-line Dex. Among the 451 pts who had received > 1 prior line of therapy, the median TTP (44 vs. 20 wks), RR (57% vs. 20%), and OS (hazard ratio 1.50, P = 0.03) were higher with Len/Dex vs. Dex. Response to Len/Dex was superior to that of Dex regardless of the type of prior therapy. Comparing pts who received Len/Dex as 2nd-line versus later salvage therapy, the median TTP was longer and response rates higher in pts treated in second-line. Conclusions: Len/Dex provided higher response rates and improved TTP compared with Dex at first relapse and beyond. TTP and response rates were superior when Len/Dex was administered earlier at first relapse compared with its use as later salvage therapy. These data support the use of Len/Dex for pts as 2nd-line therapy for relapsed MM.

[Table: see text]

Observation of Upsilon(4S) decays to pi(+)pi(-)Upsilon(1S) and pi(+)pi(-)Upsilon(2S)

Observation of Upsilon(4S) decays to pi(+)pi(-)C and pi(+)pi(-)Upsilon(2S)We present the first measurement of Upsilon(4S) decays to pi(+)pi(-)Upsilon(1S) based on a sample of 230 x 106(4S) mesons collected with the BABAR detector. We measure the product branching fractions Beta(Upsilon(4S) --> pi(+)pi(-)Upsilon(1S)) x BetaUpsilon(1S) --> mu(+)mu(-) = (2.23 +/- 0.25(stat) +/- 0.27(syst))x 10(-6) and Beta(Upsilon(4S) --> pi(+)pi(-)Upsilon(2S) x Beta(Upsilon(2S) --> mu(+)mu(-))=(1.69 +/-0.26(stat) +/- 0.20(syst)) x 10(-)6, from which we derive the partial widths Gamma(Upsilon(4S) --> pi(+)pi(-)Upsilon(1S))=(1.8 +/-0.4) keV and Gamma(Upsilon(4S) --> pi(+)pi(-)Upsilon(2S))=(2.7 +/- 0.8) keV.

Determinations of from inclusive semileptonic decays with reduced model dependence

We report two novel determinations of /|Vub/ with reduced model dependence, based on measurements of the mass distribution of the hadronic system in semileptonic B decays. Events are selected by fully reconstructing the decay of one B meson and identifying a charged lepton from the decay of the other B meson from Upsilon(4S)-->BB events. In one approach, we combine the inclusive B-->Xulambdav rate, integrated up to a maximum hadronic mass mX<1.67 GeV/c2, with a measurement of the inclusive B-->Xsgamma photon energy spectrum. We obtain /Vub/=(4.43+/-0.38stat+/-0.25syst+/-0.29theo) x 10-3. In another approach we measure the total B-->Xulambdav rate over the full phase space and find /Vub/=(3.84+/-0.70stat+/-0.30syst+/-0.10theo) x 10-3.

Phase diagram of stigmasterol-dipalmitoylphosphatidylcholine mixtures dispersed in excess water

As a simple model of rafts in plant cells, the effect of stigmasterol, one of the predominant sterols in plant plasma membranes, on the phase behavior of dipalmitoylphosphatidylcholine (DPPC) multilayers has been studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and freeze-fracture electron microscopy (FFEM) techniques. A partial phase diagram of the binary system has been constructed. Particularly, the stigmasterol concentrations of the "left endpoint" and "right endpoint" of the three-phase line have been determined using the newly developed linear and nonlinear fitting method. They are 6.2 and 23.7 mol%, respectively. Furthermore, the resemblance and difference of phase diagrams of DPPC/stigmasterol, DPPC/cholesterol, and DPPC/ergosterol have been compared and the efficiency of these sterols in promoting the formation of the liquid-ordered domains (rafts) have also been discussed.

Studies on the growth metabolism of Bacillus thuringiensis and its vegetative insecticidal protein engineered strains by microcalorimetry

The metabolic power-times curves of Bacillus thuringiensis and its vegetative insecticidal protein engineered strains were determined at 30 degrees C by using a thermal activity monitor air Isothermal Microcalorimeter, ampoule method. From the power-times curves, the maximum power (Pmax) in the log phase, the growth rate constant (k), the generation times (tG), the time of the maximum power (tmax), the heat effects (Qlog) for log phase, and the total heat effect in 45 h (Qtotal) of B. thuringiensis strains can be obtained. The results indicate that their power-times curves are different. The relationship between their metabolic power-times curves and character of bacteria metabolism, and thermokinetics and gene expression were analyzed and discussed. The character of the bacteria power-times curves reflected the physiologic character of gene expression. The microcalorimetric method proved to be a reliable and sensitive tool for the assessment of the growth metabolism, the heat output in bacteria and its engineered strains. The determination of the thermokinetic character is beneficial to the control of fermentation.

The role of methyl groups in the formation of hydrogen bond in DMSO-methanol mixtures

When examining the formation energetics of a hydrogen-bonded complex R-X-H...Y-R', focus has been almost always on the atoms directly involved, namely the atoms X, Y, and H. Little attention has been paid to the effects of the secondary alkyl groups R and R'. Taking dimethyl sulfoxide (DMSO)-methanol binary system as an example, we have studied the roles of the alkyl groups in stabilizing the hydrogen bonds by employing FTIR and NMR techniques and quantum chemical calculations. We found that methyl groups play different roles in response to the hydrogen-bonding interactions. The methyl groups of DMSO are electron-donating, whereas that of methanol is electron-withdrawing, both making positive contributions. The findings reveal non-negligible effects of secondary alkyl groups in hydrogen bonding interaction and may shed light on the understanding of other more complicated hydrogen-bonded systems in chemical and biological systems.

Monobridged Si2H4

The rotational spectrum of a new monobridged isomer of Si(2)H(4), denoted here as H(2)Si(H)SiH, has been detected by Fourier transform microwave spectroscopy of a supersonic molecular beam through the discharge products of silane. On the basis of high-level coupled cluster theory, this isomer is calculated to lie only 7 kcalmol above disilene (H(2)SiSiH(2)), the most stable isomeric arrangement of Si(2)H(4), and to be fairly polar, with a calculated dipole moment of mu = 1.14 D. The rotational spectrum of H(2)Si(H)SiH exhibits closely spaced line doubling, characteristic of a molecule undergoing high-frequency inversion. Transition state calculations indicate that inversion probably occurs in two steps: migration of the bridged hydrogen atom to form silylsilylene, H(3)SiSiH, and then internal rotation of the SiH(3) group, followed by the reverse process. The potential energy surface for this type of inversion is quite shallow, with a barrier height of only 2-3 kcalmol. Searches for the rotational lines of silylsilylene, calculated to be of comparable stability to H(2)Si(H)SiH but about five times less polar (mu = 0.23 D), have also been undertaken, so far without success, even though strong lines of H(2)Si(H)SiH have been detected. The favorable energetics and high polarity of monobridged Si(2)H(4) with respect to either disilene or silylsilylene make it a plausible candidate for radioastronomical detection in sources such as IRC + 10216, where comparably large silicon molecules such as SiS, SiC(3), and SiC(4) have already been discovered.

Evaluation of a real-time PCR assay quantifying the ruminal pool size and duodenal flow of protozoal nitrogen

We have recently developed a real-time polymerase chain reaction (PCR) assay to quantify copies of the genes encoding protozoal 18S rRNA. The assay includes procedures for isolating and concentrating protozoal cells from the rumen for use as a standard to convert 18S rRNA gene copies to a biomass basis. The current objectives were to 1) determine the degree of reduction of bacterial contamination in the protozoal standard, 2) determine if protozoal standards derived from ruminal fluid are appropriate for predicting duodenal flows, and 3) evaluate the assay's determined values for protozoal N in the rumen and flowing to the duodenum compared with independent measurements. Our protozoal collection method reduced non-associated bacterial contamination by 33-fold, the contamination of which could otherwise significantly bias RNA (microbial marker) and N percentages of concentrated protozoal fractions. Based on denaturing gradient gel electrophoresis, the use of protozoal cells isolated from ruminal fluid appears appropriate for use in quantitative assays determining protozoal N flow postruminally. Using real-time PCR, protozoal N was determined to be 4.8 and 12.7% of the rumen microbial N pool and 5.9 and 11.9% of the duodenal flow of microbial N on diets containing low (16%) or high (21%) forage neutral detergent fiber, respectively, which were comparable with independent measures and expectations.

Measurements of the absolute branching fractions of B+/- --> K+/-X(cc)

We study the two-body decays of B+/- mesons to K+/- and a charmonium state X(cc) in a sample of 210.5 fb(-1) of data from the BABAR experiment. We perform measurements of absolute branching fractions beta(B+/- --> K+/-X(cc)) using a missing mass technique, and report several new or improved results. In particular, the upper limit beta(B+/- --> K+/- X(3872)) < 3.2 x 10(-4) at 90% C.L. and the inferred lower limit beta(X(3872)J/psipi+ pi-) > 4.2% will help in understanding the nature of the recently discovered X(3872).

Search for lepton flavor violation in the decay tau+/--->e+/-gamma

A search for the nonconservation of lepton flavor in the decay tau+/--->e+/-gamma has been performed with 2.07x10(8) e+e--->tau+tau- events collected by the BABAR detector at the SLAC PEP II storage ring at a center-of-mass energy near 10.58 GeV. We find no evidence for a signal and set an upper limit on the branching ratio of Beta(tau+/--->e+/-gamma)<1.1x10(-7) at 90% confidence level.

Vegetative insecticidal protein enhancing the toxicity of Bacillus thuringiensis subsp kurstaki against Spodoptera exigua

AIMS

The objective of this work was to enhance the insecticidal activity or widen the pesticidal spectrum of a commercial Bacillus thuringiensis strain YBT1520.

METHODS AND RESULTS

A vegetative insecticidal protein gene vip3Aa7, under the control of its native promoter and cry3A promoter, was subcloned into B. thuringiensis acrystalliferous BMB171 to generate BMB8901 and BMBvip respectively. It was found that the amount of Vip3Aa7 protein produced by BMBvip was 3.2-fold more than that produced by BMB8901. Therefore, the vip3Aa7 gene under the control of cry3A promoter was transformed into strain YBT1520. The toxicity of the resulting strain BMB218V against Spodoptera exigua was 10-fold more than that of YBT1520, and that the toxicity of BMB218V against Helicoverpa armigera retained the same level as that of strain YBT1520.

CONCLUSIONS

Strain YBT1520 obtained high toxicity against S. exigua after it was transformed and expressed the foreign vip3Aa7 gene.

SIGNIFICANCE AND IMPACT OF THE STUDY

Commercial B. thuringiensis strain YBT1520 has high toxicity against H. armigera and Plutella xylostella, but almost no activity against S. exigua, which is a major crop pest in China. This work provides a new strategy for widening the activity spectrum of B. thuringiensis against agriculture pests.