On-target activity of neoadjuvant cixutumumab and combined androgen deprivation therapy for high-risk prostate cancer: A phase II trial

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Background: IMC-A12 (cixutumumab) is a fully human monoclonal antibody which targets the insulin-like growth factor receptor 1. Preclinical data suggests that the combination of androgen deprivation and IMC-A12 is much more effective than either treatment alone. This clinical trial tests the effectiveness of the combined treatment in a neoadjuvant fashion before radical prostatectomy. We have assayed serum samples from the first 18 patients to identify signs of on-target activity in this setting.

Methods: Eligible men with high risk localized prostate cancer are defined by one of the following: Gleason score ≥ 8, PSA ≥ 20, Clinical Stage T2c-T3, or a risk for relapse exceeding 50% as defined by the Kattan nomogram. Men are treated for 3 months with goserelin, bicalutamide, and biweekly IMC-A12 infusions (10 mg/kg). The primary objective of the trial is to determine the rate of pathological complete response with an accrual goal of 28 men. Using samples from the first 18 patients on study, serum protein markers were assayed by ELISA and serum PSA and glucose levels were determined by clinical laboratory analysis.

Results: Significant increases in c-peptide (1.7-fold, p<0.01), IGF-I (4.1-fold, p<0.01), IGF-II (1.32-fold, p<0.001), IGFBP-3 (1.9-fold, p<0.01), growth hormone (8-fold, p<0.01) were noted after initiation of ADT+IMC-A12, compared to pre-treatment levels. Non-significant increases of insulin (1.9-fold), IGFBP-1 (2-fold), and glucose (1.24-fold) levels were seen. Stratification of patients by nadir PSA levels correlated with residual tumor volume, likelihood of positive surgical margins and likelihood of lymph node metastases. Interestingly, patients with lower nadir PSA levels had smaller increases in c-peptide (50%, p<0.01), insulin (66%, p<0.02) and blood sugar (21%, P<0.01) compared to the patients with higher nadir PSA levels.

Conclusions: Combined with ADT in the neoadjuvant setting, IMC-A12 effectively targets the IGF-1R axis in prostate cancer patients. Metabolic differences between patients may alter the efficacy of IMC-A12 in this setting.

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Profiling influences of senescent and aged fibroblasts on prostate carcinogenesis

Experimental evidence suggests that ageing-associated alterations in the tissue microenvironment act to promote prostate carcinogenesis. In this review, we survey the cellular state of senescence, review its causes, and describe associations with ageing and cancer. We further discuss senescent stromal gene expression changes, which may mediate these effects, and that may serve as therapeutic targets.

Expression of MFA1 and STE6 is sufficient for mating type-independent secretion of yeast a-factor, but not mating competence

The yeast a-factor mating peptide and its transporter Ste6 are normally expressed only in MATa haploid cells. The a-factor is initially produced as a 36- or 38-residue peptide precursor and must undergo extensive post-translational processing to produce an active 12 amino-acid lipopeptide. To better understand the steps required for Ste6-dependent a-factor transport, we have reconstituted a-factor synthesis and transport in MATalpha haploids and MATa/alpha diploids. Ste6 and a-factor were stably expressed in MATalpha and MATa/alpha cells and the ectopically expressed a-factor was correctly processed. In addition, Ste6 was able to transport a-factor from all cell types, indicating that once expressed no other MATa-specific functions are required. However, despite significant levels of a-factor secretion, MATalpha cells are unable to support efficient mating.

In vitro evaluation of a carbon fiber post

The purpose of this study was to evaluate the influence of endodontic and restorative procedures on fracture resistance of teeth, and to compare the incidence of root fracture in teeth with clinical crowns removed that were restored with three different types of post and a composite core build-up. Seven groups of 10 extracted maxillary canines were used. A control group had only a crown preparation, but no endodontic treatment. Three groups had endodontic treatment, crown preparation, and the access restored. Three groups had endodontic treatment, the crown totally removed, a tapered, parallel, or carbon post placed, and a composite build-up. All specimens were subjected to a 45-degree load at 0.5 mm/min until failure occurred. The force at failure and the location of fracture were recorded. The groups with post and composite build-ups failed at significantly lower force than the teeth in which the crowns had not been removed. There were no significant differences in the amount of force required to produce failure among the three groups with different posts and a composite build-up. The group restored with the carbon post had no root fractures, whereas there were five fractures in each of the parallel and tapered post groups.

Redesigning metabolic networks using mathematical programming

The design of new generation bioprocessing plants is increasingly dependent on the design of process-compatible microorganisms. The latter, whether through genetic or physiological manipulations, can be greatly assisted by metabolic engineering. An emerging powerful tool in metabolic engineering research is computer-assisted cell design using mathematical programming. In this work, the problem of optimizing cellular metabolic networks has been formulated as a Mixed Integer Nonlinear Programming (MINLP) model. The model can assist genetic engineers to identify which cellular enzymes should be modified, and the new levels of activity required to produce an optimal network. Results are presented from the tricarboxylic acid cycle in Dictyostelium discoideum. Copyright 1998 John Wiley & Sons, Inc.

On the topological features of optimal metabolic pathway regimes

In this work, the stoichiometric metabolic network of Escherichia coli has been formulated as a comprehensive mathematical programming model, with a view to identifying the optimal redirection of metabolic fluxes so that the yield of particular metabolites is maximized. Computation and analysis has shown that the over-production of a given metabolite at various cell growth rates is only possible for a finite ordered set of metabolic structures which, in addition, are metabolite-specific. Each regime has distinct topological features, although the actual flux values differ. Application of the model to the production of 20 amino acids on four carbon sources (glucose, glycerol, lactate, and citrate) has also indicated that, for fixed cell composition, the maximum amino acid yield decreases linearly with increasing cell growth rate. However, when the cell composition varies with cell growth rate, the amino-acid yield varies in a nonlinear manner. Medium optimization studies have also demonstrated that, of the above substrates, glucose and glycerol are the most efficient from the energetic viewpoint. Finally, model predictions are analyzed in the light of experimental data.

Use of Nisin in Ice Cream and Effect on the Survival of Listeria monocytogenes †

The survival characteristics of Listeria monocytogenes V7 were investigated in a full fat (10% fat) and reduced fat (3%) ice cream. The effect of nisin on the survival of Listeria monocytogenes in the ice creams was also evaluated. Ice cream mixes varying in composition were manufactured and inoculated with L. monocytogenes , passed through a "soft serve" freezer and then frozen at -18°C for up to 3 months. Samples were removed from storage throughout the three months, thawed, and then plated on Listeria -selective agar. In the samples that did not contain nisin, no reduction in the cell population was observed throughout manufacture and frozen storage. When nisin was present in the ice cream, a significant reduction in the cell population (P < .05) was observed. At the end of 3 months of frozen storage, no Listeria cells were detected in the 3% fat ice cream containing nisin. The effect of nisin on Listeria cells was decreased somewhat in the higher fat ice cream but this decrease was not significant over the 3 month storage. The stability of nisin in the ice cream remained constant throughout storage at -18°C.

Three-Dimensional Flow in the Upper Ocean

Measurements made from the Research Platform FLIP provide some of the first direct observations of three-dimensional flow within the surface mixed layer of the ocean. Relatively narrow regions of downwelling flow were found within the mixed layer, in coincidence with bands of convergent surface flow. At mid-depth in the mixed layer, the downwelling flow had magnitudes of up to 0.2 meter per second and was accompanied by a downwind, horizontal jet of comparable magnitude. There is some evidence that these motions transport heat and phytoplankton within the mixed layer.