Quantum Gravity in 2+1 Dimensions: The Case of a Closed Universe

In three spacetime dimensions, general relativity drastically simplifies, becoming a ``topological'' theory with no propagating local degrees of freedom. Nevertheless, many of the difficult conceptual problems of quantizing gravity are still present. In this review, I summarize the rather large body of work that has gone towards quantizing (2+1)-dimensional vacuum gravity in the setting of a spatially closed universe.Comment: 61 pages, draft of review for Living Reviews; comments, criticisms, additions, missing references welcome; v2: minor changes, added reference

Targeted therapies in bladder cancer: an overview of in vivo research

Survival of patients with muscle-invasive bladder cancer is poor and new therapies are needed. Currently, none of the targeted agents that are approved for cancer therapy have been approved for the treatment of bladder cancer and the few clinical trials that have been performed had limited success, often owing to a lack of efficacy and toxic effects. However, many other novel targeted agents have been investigated in animal models of bladder cancer. EGFR, FGFR-3, VEGF, mTOR, STAT3, the androgen receptor and CD24 are molecular targets that could be efficiently inhibited, resulting in reduced tumour growth, and that have been investigated in multiple independent studies. Several other targets, for example COX-2, IL-12, Bcl-xL, livin and choline kinase a, have also been observed to inhibit tumour growth, but these findings have not been replicated to date. Limitations of several studies include the use of cell lines with mutations downstream of the target, providing resistance to the tested therapy. Furthermore, certain technologies, such as interfering RNAs, although effective in vitro, are not yet ready for clinical applications. Further preclinical research is needed to discover and evaluate other possible targets, but several validated targets are now available to be studied in clinical trials

Bladder Cancer

Bladder cancer is a highly prevalent disease associated with substantial morbidity, mortality and cost. Environmental or occupational exposures to carcinogens, and especially tobacco, are the main risk factors for bladder cancer. Most bladder cancers are diagnosed after patients complain of macroscopic haematuria, and cases are confirmed after transurethral resection of bladder tumour (TURBT), which also serves as the first stage of treatment. Bladder cancer develops via two distinct pathways, giving rise to non-muscle-invasive papillary tumours and non-papillary (solid) muscle-invasive tumours. Both subtypes have unique pathological features and different molecular characteristics. Indeed, The Cancer Genome Atlas project identified genetic drivers of muscle-invasive bladder cancer (MIBC) as well as subtypes of MIBC with unique characteristics and therapeutic responses. For non-muscle-invasive bladder cancer (NMIBC), intravesical therapies (primarily Bacillus Calmette–Guérin (BCG)) with maintenance are the main treatments to prevent recurrence and progression after initial TURBT; additional therapies are needed for those who do not respond to BCG. For localized MIBC, optimizing care is important as is the goal to reduce morbidity of removing the bladder. In metastatic disease, advancements in genetic understanding and immunotherapy are being translated into novel therapies