Efficacy of Different Bacillus of Calmette-Guérin (BCG) Strains on Recurrence Rates among Intermediate/High-Risk Non-Muscle Invasive Bladder Cancers (NMIBCs): Single-Arm Study Systematic Review, Cumulative and Network Meta-Analysis

BACKGROUND

In an era of Bacillus of Calmette-Guérin (BCG) shortages, the comparative efficacy from different adjuvant intravesical BCG strains in non-muscle invasive bladder cancer (NMIBC) has not been clearly elucidated. We aim to compare, through a systematic review and meta-analysis, the cumulative BC recurrence rates and the best efficacy profile of worldwide available BCG strains over the last forty years.

METHODS

PubMed, Scopus, Web of Science, Embase, and Cochrane databases were searched from 1982 up to 2022. A meta-analysis of pooled BC recurrence rates was stratified for studies with ≤3-y vs. >3-y recurrence-free survival (RFS) endpoints and the strain of BCG. Sensitivity analysis, sub-group analysis, and meta-regression were implemented to investigate the contribution of moderators to heterogeneity. A random-effect network meta-analysis was performed to compare BCG strains on a multi-treatment level.

RESULTS

In total, n = 62 series with n = 15,412 patients in n = 100 study arms and n = 10 different BCG strains were reviewed. BCG Tokyo 172 exhibited the lowest pooled BC recurrence rate among studies with ≤3-y RFS (0.22 (95%CI 0.16-0.28). No clinically relevant difference was noted among strains at >3-y RFS outcomes. Sub-group and meta-regression analyses highlighted the influence of NMIBC risk-group classification and previous intravesical treated categories. Out of the n = 11 studies with n = 7 BCG strains included in the network, BCG RIVM, Tice, and Tokyo 172 presented with the best-predicted probability for efficacy, yet no single strain was significantly superior to another in preventing BC recurrence risk.

CONCLUSION

We did not identify a BCG stain providing a clinically significant lower BC recurrence rate. While these findings might discourage investment in future head-to-head randomized comparison, we were, however, able to highlight some potential enhanced benefits from the genetically different BCG RIVM, Tice, and Tokyo 172. This evidence would support the use of such strains for future BCG trials in NMIBCs.

Terahertz-based retrieval of the spectral phase and amplitude of ultrashort laser pulses

Terahertz (THz) radiation is of great interest for a variety of applications, e.g., particle accelerations, spectroscopy investigations of quantum systems, and high-field study of materials. One of the most common laser-based processes to produce THz pulses is optical rectification, which transduces an infrared pump laser to the THz domain (0.1-20 THz). In this work, we propose and theoretically describe a method to characterize the amplitude and phase of the electric field of the pump laser pulse relying on THz generation and detection. We demonstrate with a numerical example how THz radiation can be used as diagnostics to characterize laser pulses with temporal length at the femtosecond level.

Resonant plasma excitation by single-cycle THz pulses

In this paper, an alternative perspective for the generation of millimetric high-gradient resonant plasma waves is discussed. This method is based on the plasma-wave excitation by energetic single-cycle THz pulses whose temporal length is comparable to the plasma wavelength. The excitation regime discussed in this paper is the quasi-nonlinear regime that can be achieved when the normalized vector potential of the driving THz pulse is on the order of unity. To investigate this regime and determine the strength of the excited electric fields, a Particle-In-Cell (PIC) code has been used. It has been found that by exploiting THz pulses with characteristics currently available in laboratory, longitudinal electron plasma waves with electric gradients up to hundreds MV/m can be obtained. The mm-size nature of the resonant plasma wave can be of great utility for an acceleration scheme in which high-brightness electron bunches are injected into the wave to undergo a strong acceleration. The long-size nature of the acceleration bucket with respect to the short length of the electron bunches can be handled in a more robust manner in comparison with the case when micrometric waves are employed.

Mutational analysis of the iron binding site of Saccharomyces cerevisiae ferroxidase Fet3. An in vivo study

The role of residues predicted to be involved in the binding of iron by the yeast ferroxidase Fet3 has been studied by site-directed mutagenesis. The effect of Fet3 mutations E185A, E185Q, Y354F, D409V and H489D has been investigated in vivo by kinetic analyses of high affinity iron uptake. Our results indicate that Glu-185 is critical for the binding of iron, since substitution of this residue with Ala or Gln strongly affects both growth and the kinetic parameters of high affinity iron uptake, greatly increasing K(m). Mutations Y354F and D409V result in less severe alteration of high affinity iron uptake, while mutant H489D is unable to grow under conditions of iron limitation.