A Branch and Price Algorithm for the k-splittable Maximum Flow Problem

The Maximum Flow Problem with flow width constraints is a NP-hard problem. Two models are proposed: the first model is a compact node-arc model using two flow conservation blocks per path. For each path, one block de?nes the path while the other one send the right amount of flow on it. The second model is an extended arc-path model. It is obtained from the first model after a Dantzig-Wolfe reformulation. It is an extended model as it relies on the set of all the paths between the source and the sink nodes. Some symmetry breaking constraints are used to improve the model. A branch and price algorithm is proposed to solve the problem. The column generation reduces to the computation of a shortest path whose cost depends on weights on the arcs and on the path capacity. A polynomial time algorithm is proposed to solve this subproblem. Computational results are shown on a set of medium-sized instances to show the effectiveness of our approach

Growth on blood agar discriminates Mycobacterium avium and Mycobacterium intracellulare

Mycobacterium intracellulare and Mycobacterium avium (MAC) require specialized culture and identification procedures. To simplify the diagnosis, we inoculated reference strains, and 85 M. avium and 12 M. intracellulare clinical isolates, on egg-based and sheep blood agar. After 5 days of culture, there were significantly more colonies on sheep blood than on egg-based agar for M. avium (ratio: 250.5 ± 209) but not for M. intracellulare (ratio: 0.44 ±0.11). Using a ratio ≥20, the sensitivity of the identification of an MAC isolate as M. avium was 97.65%, the specificity was 100%, and the positive predictive value was 100%. Differential growth on egg-based and blood agar is an aid to the identification of MAC isolates

A Once-Weekly R207910-containing Regimen Exceeds Activity of the Standard Daily Regimen in Murine Tuberculosis

Rationale: R207910 (TMC207 or J) is a member of the diarylquinolines, a new family of antituberculous drugs with high bactericidal activity when given daily in the murine model of tuberculosis. R207910 exhibits a long half-life and thus is a good candidate for once-weekly therapy of tuberculosis. Objectives: To study the activity of once-weekly R207910 monotherapy and combinations of R207910 with other antituberculous agents (isoniazid, rifapentine, moxifloxacin, and pyrazinamide). Methods: The established infection model of murine tuberculosis was used. Colony counts were determined in the lungs. Measurements and Main Results: Eight weeksofmonotherapy reduced the bacillary load by 3 to 4 log10 for rifapentine and by 5 to 6 log10 for R207910 (P , 0.05). The addition of rifapentine and isoniazid or moxifloxacin did not improve the bactericidal activity of R207910 monotherapy. In contrast, the triple combination of R207910 plus rifapentine plus pyrazinamide given once weekly for 2 months (i.e., a total of only eight administrations), was significantly (P , 0.05) more active than R207910 monotherapy or other R207910 combinations, and led to lung culture negativity in 9 of 10 mice, whereas all lungs were culture positive in the groups treated with other drug combinations. Moreover, R207910 plus rifapentine plus pyrazinamide given once weekly was more active than the current standard regimen of rifampin plus isoniazid plus pyrazinamide given five times per week. Conclusions: The unprecedented activity of the triple combination of R207910 plus rifapentine plus pyrazinamide suggests that it may be feasible to develop a fully intermittent once-weekly regimen

Bis[(2R,6S)-4-(5-amino-3-carb­oxy-1-cyclo­propyl-6,8-difluoro-4-oxo-1,4-dihydro­quinolin-7-yl)-2,6-dimethyl­piperazin-1-ium] sulfate penta­hydrate

The title compound, C19H23F2N4O3 +·0.5SO4 2−·2.5H2O, an anti­bacterial fluoro­quinolone, crystallized as a racemic twin (major twin component = 0.633) in the chiral space group P1. The asymmetric unit contains two sparfloxacinium cations, one sulfate anion and five mol­ecules of water of solvation. The bond lengths and angles of both cations are almost identical. The quinoline ring systems in the cations are essentially planar, the mean deviations from the best plane being 0.045 (2) and 0.054 (2) Å and make π–π inter­actions with each other [centroid–centroid distances of 3.692 (4) Å and 3.744 (4) Å]. The crystal structure features inter­molecular O—H⋯O, O—H⋯S, N+—H⋯O, N+—H⋯S and N—H⋯O hydrogen bonds together with intra­molecular O—H⋯O and N—H⋯O hydrogen bonds. As a result, a three-dimensional supra­molecular structure is observed

Bedaquiline, an FDA-approved antibiotic, inhibits mitochondrial function and potently blocks the proliferative expansion of stem-like cancer cells (CSCs)

Bedaquiline (a.k.a., Sirturo) is an anti‐microbial agent, which is approved by the FDA for the treatment of multi‐drug resistant pulmonary tuberculosis (TB). Bedaquiline is a first‐in‐class diaryl‐quinoline compound, that mechanistically inhibits the bacterial ATP‐synthase, and shows potent activity against both drug‐sensitive and drug‐ resistant TB. Interestingly, eukaryotic mitochondria originally evolved from engulfed aerobic bacteria. Thus, we hypothesized that, in mammalian cells, bedaquiline might also target the mitochondrial ATP‐synthase, leading to mitochondrial dysfunction and ATP depletion. Here, we show that bedaquiline has anti‐cancer activity, directed against Cancer Stem‐like Cells (CSCs). More specifically, we demonstrate that bedaquiline treatment of MCF7 breast cancer cells inhibits mitochondrial oxygen‐consumption, as well as glycolysis, but induces oxidative stress. Importantly, bedaquiline significantly blocks the propagation and expansion of MCF7‐derived CSCs, with an IC‐50 of approx. 1‐μM, as determined using the mammosphere assay. Similarly, bedaquiline also reduces both the CD44+/CD24low/‐ CSC and ALDH+ CSC populations, under anchorage‐independent growth conditions. In striking contrast, bedaquiline significantly increases oxygen consumption in normal human fibroblasts, consistent with the fact that it is well‐tolerated in patients treated for TB infections. As such, future pre‐clinical studies and human clinical trials in cancer patients may be warranted. Interestingly, we also highlight that bedaquiline shares certain structural similarities with trans‐piceatannol and trans‐ resveratrol, which are known natural flavonoid inhibitors of the mitochondrial ATP‐synthase (complex V) and show anti‐ aging properties

Sterilizing Activity of Second-Line Regimens Containing TMC207 in a Murine Model of Tuberculosis

The sterilizing activity of the regimen used to treat multidrug resistant tuberculosis (MDR TB) has not been studied in a mouse model. (TB) strain H37Rv, treated with second-line drug combinations with or without the diarylquinoline TMC207, and then followed without treatment for 3 more months to determine relapse rates (modified Cornell model).Bactericidal efficacy was assessed by quantitative lung colony-forming unit (CFU) counts. Sterilizing efficacy was assessed by measuring bacteriological relapse rates 3 months after the end of treatment.The relapse rate observed after 12 months treatment with the WHO recommended MDR TB regimen (amikacin, ethionamide, pyrazinamide and moxifloxacin) was equivalent to the relapse rate observed after 6 months treatment with the recommended drug susceptible TB regimen (rifampin, isoniazid and pyrazinamide). When TMC207 was added to this MDR TB regimen, the treatment duration needed to reach the same relapse rate dropped to 6 months. A similar relapse rate was also obtained with a 6-month completely oral regimen including TMC207, moxifloxacin and pyrazinamide but excluding both amikacin and ethionamide.In this murine model the duration of the WHO MDR TB treatment could be reduced to 12 months instead of the recommended 18–24 months. The inclusion of TMC207 in the WHO MDR TB treatment regimen has the potential to further shorten the treatment duration and at the same time to simplify treatment by eliminating the need to include an injectable aminoglycoside

T-cell and serological responses to Erp, an exported Mycobacterium tuberculosis protein, in tuberculosis patients and healthy individuals

<p>Abstract</p> <p>Background</p> <p>The identification of antigens able to differentiate tuberculosis (TB) disease from TB infection would be valuable. Cellular and humoral immune responses to Erp (Exported repetitive protein) – a recently identified <it>M. tuberculosis </it>protein – have not yet been investigated in humans and may contribute to this aim.</p> <p>Methods</p> <p>We analyzed the cellular and humoral immune responses to Erp, ESAT-6, Ag85B and PPD in TB patients, in BCG⁺individuals without infection, BCG⁺individuals with latent TB infection (LTBI) and BCG^-controls. We used lymphoproliferation, ELISpot IFN-γ, cytokine production assays and detection of specific human antibodies against recombinant <it>M. tuberculosis </it>proteins.</p> <p>Results</p> <p>We included 22 TB patients, 9 BCG⁺individuals without TB infection, 7 LTBI and 7 BCG^-controls. Erp-specific T cell counts were higher in LTBI than in the other groups. Erp-specific T cell counts were higher in LTBI subjects than TB patients (median positive frequency of 211 SFC/10⁶PBMC (range 118–2000) for LTBI subjects compared to 80 SFC/10⁶PBMC (range 50–191), p = 0.019); responses to PPD and ESAT-6 antigens did not differ between these groups. IFN-γ secretion after Erp stimulation differed between TB patients and LTBI subjects (p = 0.02). Moreover, LTBI subjects but not TB patients or healthy subjects produced IgG3 against Erp.</p> <p>Conclusion</p> <p>The frequencies of IFN-γ-producing specific T cells, the IFN-γ secretion and the production of IgG3 after Erp stimulation are higher in LTBI subjects than in TB patients, whereas PPD and ESAT-6 are not.</p