SUMMARY Bone metastasis is a major health threat to breast cancer patients. Tumor-derived Jagged1 represents a central node in mediating tumor-stromal interactions that promote osteolytic bone metastasis. Here, we report the development of a highly effective fully human monoclonal antibody against Jagged1 (clone 15D11). In addition to its inhibitory effect on bone metastasis of Jagged1-expressing tumor cells, 15D11 dramatically sensitizes bone metastasis to chemotherapy, which induces Jagged1 expression in osteoblasts to provide a survival niche for cancer cells. We further confirm the bone metastasis-promoting function of osteoblast-derived Jagged1 using osteoblast-specific Jagged1 transgenic mouse model. These findings establish 15D11 as a potential therapeutic agent for the prevention or treatment of bone metastasis.

Historical controls (HCs) can be used for model parameter estimation at the study design phase, adaptation within a study, or supplementation or replacement of a control arm. Currently on the latter, there is no practical roadmap from design to analysis of a clinical trial to address selection and inclusion of HCs, while maintaining scientific validity. This paper provides a comprehensive roadmap for planning, conducting, analyzing and reporting of studies using HCs, mainly when a randomized clinical trial is not possible. We review recent applications of HC in clinical trials, in which either predominantly a large treatment effect overcame concerns about bias, or the trial targeted a life-threatening disease with no treatment options. In contrast, we address how the evidentiary standard of a trial can be strengthened with optimized study designs and analysis strategies, emphasizing rare and pediatric indications. We highlight the importance of simulation and sensitivity analyses for estimating the range of uncertainties in the estimation of treatment effect when traditional randomization is not possible. Overall, the paper provides a roadmap for using HCs.

Caenorhabditis elegans can serve as a substitute host for the study of microbial pathogenesis. We found that mutations in genes of the fungal pathogen Cryptococcus neoformans involved in mammalian virulence allow C. elegans to produce greater numbers of progeny than when exposed to wild-type fungus. We used this property to screen a library of C. neoformans mutants for strains that permit larger C. elegans brood sizes. In this screen, we identified a gene homologous to Saccharomyces cerevisiae ROM2. C. neoformans rom2 mutation resulted in a defect in mating and growth defects at elevated temperature or in the presence of cell wall or hyperosmolar stresses. An effect of the C. neoformans rom2 mutation in virulence was confirmed in a murine inhalation infection model. We propose that a screen for progeny-permissive mutants of microorganisms can serve as a high-throughput method for identifying novel loci related to mammalian pathogenesis.The nematode Caenorhabditis elegans is emerging as a substitute host for elucidating important mechanisms of fungal and bacterial pathogenesis, thanks to genetic tractability, anatomical simplicity, and the availability of extensive genetic and genomic resources (23,35). The C. elegans killing assay used in previous studies entails observing a synchronized population of nematodes for kinetics of death on a lawn of the microbe being studied. Living and dead worms are counted at ϳ24-h intervals, and the LT 50 , or time for 50% of the nematodes to die, is calculated (1,7,10,15,24,38). This killing assay has been used to study effectively gram-negative (1, 15, 38) and gram-positive (10) bacteria, as well as the human pathogenic fungus Cryptococcus neoformans (24,25).Interestingly, C. elegans does not produce a sustainable brood of progeny in the presence of C. neoformans or some other pathogens (10,25,38). We hypothesized that a screen of brood size would circumvent the need for labor-intensive manual assessment for living versus dead nematodes. The aim of this study was to investigate the role of the C. neoformans virulence factors (such as capsule and melanin and their regulatory pathways) in C. elegans progeny production. Also, we evaluate the hypothesis that brood size can be used effectively as a facile marker for virulence in the C. elegans-C. neoformans system. Of note is that no progeny-based screen has been reported previously. MATERIALS AND METHODSStrains and media. The C. neoformans strains used in these experiments are summarized in Table 1 or described in the text. Yeast cultures were maintained as frozen stocks or on yeast-peptone-dextrose (YPD; Difco) agar plates and grown in YPD. C. neoformans cultures were grown at 30°C unless otherwise specified. Cryptococcus laurentii cultures were grown at 25°C. The standard C. elegans strain N2 Bristol was maintained at 15°C and propagated on Escherichia coli.C. elegans killing assays were performed as previously described (24, 25) with minor modifications. C. neoformans strains were inoculated into 2 ml of YPD and grown at 30°C f...

Summary:Background: Acetone, one of the principal ketone bodies elevated during treatment with the ketogenic diet, exhibits anticonvulsant properties that may contribute to the seizure protection conferred by the diet. The anticonvulsant mechanism of acetone is unknown, but it is metabolized to several bioactive substances that could play a role.Methods: Acetone and its major metabolites-acetol, 1,2-propanediol, methylglyoxal, and pyruvic acid-were assessed for anticonvulsant activity in two mouse seizure models. Various doses of the substances administered intraperitoneally were characterized for their ability to elevate the threshold for clonic seizures induced by intravenous infusion of pentylenetetrazol (PTZ) and for protection against tonic seizures induced by subcutaneous bolus administration of 4-aminopyridine (4-AP). The inverted-screen test was used to assess acute neurological toxicity.Results: Acetone (1-32 mmol/kg, i.p.), in a dose-dependent fashion, elevated the PTZ threshold and conferred protection against 4-AP seizures (ED 50 , 26.3 mmol/kg). Effective doses of acetone (10-32 mmol/kg) did not cause motor impairment in the inverted-screen test (TD 50 , 45.7 mmol/kg). In doses 10-fold greater than the minimally effective dose of acetone (3.2 mmol/kg), the metabolites acetol, 1,2-propanediol, and pyruvic acid were inactive in the PTZ model. At higher doses that produced motor impairment, acetol and 1,2-propanediol (but not pyruvic acid) did elevate the PTZ threshold. Methylglyoxal had both proconvulsant and anticonvulsant actions, and had substantial toxicity, producing respiratory distress, motor impairment, and death. None of the acetone metabolites protected against 4-AP seizures.Conclusions: This study confirms the broad-spectrum anticonvulsant properties of acetone and indicates that the seizure protection conferred is unlikely to result from its major metabolic products.