ABSTRACT
Small molecule can be utilized to restore the effectiveness of existing major classes of antibiotics against antibiotic-resistant bacteria. In this study, it is demonstrated that celastrol, a natural compound, can modify the bacterial cell wall and subsequently render bacteria more suceptible to ß-lactam antibiotics. It is shown that celastrol leads to incomplete cell wall crosslinking by modulating levels of c-di-AMP, a secondary messenger, in methicillin-resistant Staphylococcus aureus (MRSA). This mechanism enables celastrol to act as a potentiator, effectively rendering MRSA susceptible to a range of penicillins and cephalosporins. Restoration of in vivo susceptibility of MRSA to methicillin is also demonstrated using a sepsis animal model by co-administering methicillin along with celastrol at a much lower amount than that of methicillin. The results suggest a novel approach for developing potentiators for major classes of antibiotics by exploring molecules that re-program metabolic pathways to reverse ß-lactam-resistant strains to susceptible strains.
Subject(s)
Anti-Bacterial Agents , Methicillin-Resistant Staphylococcus aureus , Peptidoglycan , beta-Lactam Resistance , Methicillin-Resistant Staphylococcus aureus/drug effects , Peptidoglycan/metabolism , beta-Lactam Resistance/drug effects , Animals , Anti-Bacterial Agents/pharmacology , Disease Models, Animal , Microbial Sensitivity Tests , Mice , Pentacyclic Triterpenes/pharmacology , Staphylococcal Infections/drug therapy , Cell Wall/metabolism , Cell Wall/drug effects , beta-Lactams/pharmacology , Triterpenes/pharmacology , Triterpenes/metabolismABSTRACT
The emergence of resistance against the last-resort antibiotic vancomycin in staphylococcal infections is a serious concern for human health. Although various drug-resistant pathogens of diverse genetic backgrounds show higher virulence potential, the underlying mechanism behind this is not yet clear due to variability in their genetic dispositions. In this study, we investigated the correlation between resistance and virulence in adaptively evolved isogenic strains. The vancomycin-susceptible Staphylococcus aureus USA300 was exposed to various concentrations of vancomycin repeatedly as a mimic of the clinical regimen to obtain mutation(s)-accrued-clonally-selected (MACS) strains. The phenotypic analyses followed by expression of the representative genes responsible for virulence and resistance of MACS strains were investigated. MACS strains obtained under 2 and 8 µg/ml vancomycin, named Van2 and Van8, respectively; showed enhanced vancomycin minimal inhibitory concentrations (MIC) to 4 and 16 µg/ml, respectively. The cell adhesion and invasion of MACS strains increased in proportion to their MICs. The correlation between resistance and virulence potential was partially explained by the differential expression of genes known to be involved in both virulence and resistance in MACS strains compared to parent S. aureus USA300. Repeated treatment of vancomycin against vancomycin-susceptible S. aureus (VSSA) leads to the emergence of vancomycin-resistant strains with variable levels of enhanced virulence potentials.
Subject(s)
Anti-Bacterial Agents , Microbial Sensitivity Tests , Staphylococcal Infections , Staphylococcus aureus , Vancomycin Resistance , Vancomycin , Vancomycin/pharmacology , Anti-Bacterial Agents/pharmacology , Virulence/genetics , Staphylococcus aureus/drug effects , Staphylococcus aureus/genetics , Staphylococcus aureus/pathogenicity , Staphylococcal Infections/microbiology , Vancomycin Resistance/genetics , Humans , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Mutation , Virulence Factors/genetics , Gene Expression Regulation, Bacterial/drug effectsABSTRACT
AIMS: This study aimed to develop an editable structural scaffold for improving drug development, including pharmacokinetics and pharmacodynamics of antibiotics by using synthetic compounds derived from a (hetero)aryl-quinoline hybrid scaffold. METHODS AND RESULTS: In this study, 18 CF3-substituted (hetero)aryl-quinoline hybrid molecules were examined for their potential antibacterial activity against Staphylococcus aureus by determining minimal inhibitory concentrations. These 18 synthetic compounds represent modifications to key regions of the quinoline N-oxide scaffold, enabling us to conduct a structure-activity relationship analysis for antibacterial potency. Among the compounds, 3 m exhibited potency against with both methicillin resistant S. aureus strains, as well as other Gram-positive bacteria, including Enterococcus faecalis and Bacillus subtilis. We demonstrated that 3 m disrupted the bacterial proton motive force (PMF) through monitoring the PMF and conducting the molecular dynamics simulations. Furthermore, we show that this mechanism of action, disrupting PMF, is challenging for S. aureus to overcome. We also validated this PMF inhibition mechanism of 3 m in an Acinetobacter baumannii strain with weaken lipopolysaccharides. Additionally, in Gram-negative bacteria, we demonstrated that 3 m exhibited a synergistic effect with colistin that disrupts the outer membrane of Gram-negative bacteria. CONCLUSIONS: Our approach to developing editable synthetic novel antibacterials underscores the utility of CF3-substituted (hetero)aryl-quinoline scaffold for designing compounds targeting the bacterial proton motive force, and for further drug development, including pharmacokinetics and pharmacodynamics.
Subject(s)
Anti-Bacterial Agents , Indoles , Microbial Sensitivity Tests , Proton-Motive Force , Quinolines , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Quinolines/pharmacology , Quinolines/chemistry , Proton-Motive Force/drug effects , Indoles/pharmacology , Indoles/chemistry , Structure-Activity Relationship , Methicillin-Resistant Staphylococcus aureus/drug effects , Molecular Dynamics Simulation , Acinetobacter baumannii/drug effects , Enterococcus faecalis/drug effects , Staphylococcus aureus/drug effects , Bacillus subtilis/drug effectsABSTRACT
Potential synergism between Bruton's tyrosine kinase (BTK) inhibitor and lenalidomide in treating aggressive B-cell lymphoma has been suggested. Here, the authors report a single-arm phase II clinical trial of combination of acalabrutinib, lenalidomide and rituximab (R2A) in patients with aggressive relapsed/refractory aggressive (R/R) B-cell non-Hodgkin lymphoma (NHL). The primary endpoint of this study is objective response rate (ORR), and the secondary endpoints are complete remission (CR) rate, duration of response (DoR), progression-free survival (PFS) and overall survival (OS). A total of 66 patients are enrolled mostly with diffuse large B-cell lymphoma. The ORR is 54.5% and CR rate is 31.8% meeting the primary end point. The median DoR is 12.9 months, and 1-year PFS and OS rate is 33.1% and 67.5% respectively. Adverse events (AE) are manageable with the most frequent AE being neutropenia (31.8%). Patients with MYD88 mutations, subtypes known for NF-κB activation, and high BTK expression by immunohistochemistry respond well. Overall, these results show a significant efficacy of the R2A regimen in patients with aggressive R/R B-cell NHL, with exploratory biomarkers suggesting potential associations with response. (ClinicalTrials.gov 51 identifier: NCT04094142).
Subject(s)
Benzamides , Lymphoma, Large B-Cell, Diffuse , Pyrazines , Humans , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Disease-Free Survival , Lenalidomide/therapeutic use , Lymphoma, Large B-Cell, Diffuse/drug therapy , Rituximab/therapeutic use , Treatment OutcomeABSTRACT
PURPOSE: The role of allogeneic stem cell transplantation (alloSCT) in multiple myeloma (MM) treatment remains controversial. We conducted a retrospective, multicenter, nationwide study in Korea to evaluate the outcomes of alloSCT in Asian patients with MM. MATERIALS AND METHODS: Overall, 109 patients with MM who underwent alloSCT between 2003 and 2020 were included in this study. Data were collected from the Korean Multiple Myeloma Working Party Registry. RESULTS: The overall response rate and stringent complete response plus complete response (CR) rates were 67.0 and 46.8%, respectively, after alloSCT. At a median follow-up of 32.5 months, the 3-year probability of progression-free survival (PFS) and overall survival (OS) rates were 69.3% and 71.8%, respectively. The 3-year probabilities of OS rates in the upfront alloSCT, tandem auto-alloSCT, and later alloSCT groups were 75.0%, 88.9%, and 61.1%, respectively. Patients who achieved CR before or after alloSCT had significantly longer OS (89.8 vs. 18 months and 89.8 vs. 15.2 months, respectively). Even though patients who did not achieve CR prior to alloSCT, those who achieve CR after alloSCT had improved PFS and OS compared to those who had no achievement of CR both prior and after alloSCT. Patients who underwent alloSCT with 1-2 prior treatment lines had improved PFS (22.4 vs. 4.5 months) and OS (45.6 vs. 15.3 months) compared to those with three or more prior treatment lines. CONCLUSION: AlloSCT may be a promising therapeutic option especially for younger, chemosensitive patients with earlier implementation from relapse.
Subject(s)
Hematopoietic Stem Cell Transplantation , Multiple Myeloma , Transplantation, Homologous , Humans , Multiple Myeloma/therapy , Multiple Myeloma/mortality , Male , Retrospective Studies , Female , Middle Aged , Republic of Korea/epidemiology , Hematopoietic Stem Cell Transplantation/methods , Adult , Aged , Registries , Survival RateABSTRACT
Synthetic biology approaches offer potential for large-scale and sustainable production of natural products with bioactive potency, including ginsenosides, providing a means to produce novel compounds with enhanced therapeutic properties. Ginseng, known for its non-toxic and potent qualities in traditional medicine, has been used for various medical needs. Ginseng has shown promise for its antioxidant and neuroprotective properties, and it has been used as a potential agent to boost immunity against various infections when used together with other drugs and vaccines. Given the increasing demand for ginsenosides and the challenges associated with traditional extraction methods, synthetic biology holds promise in the development of therapeutics. In this review, we discuss recent developments in microorganism producer engineering and ginsenoside production in microorganisms using synthetic biology approaches.
ABSTRACT
Antibiotic-resistant Gram-negative bacteria remain a globally leading cause of bacterial infection-associated mortality, and it is imperative to identify novel therapeutic strategies. Recently, the advantage of using antibacterials selective against Gram-negative bacteria has been demonstrated with polymyxins that specifically target the lipopolysaccharides of Gram-negative bacteria. However, the severe cytotoxicity of polymyxins limits their clinical use. Here, we demonstrate that polymyxin B nonapeptide (PMBN), a polymyxin B derivative without the terminal amino acyl residue, can significantly enhance the effectiveness of commonly used antibiotics against only Gram-negative bacteria and their persister cells. We show that although PMBN itself does not exhibit antibacterial activity or cytotoxicity well above the 100-fold minimum inhibitory concentration of polymyxin B, PMBN can increase the potency of co-treated antibiotics. We also demonstrate that using PMBN in combination with other antibiotics significantly reduces the frequency of resistant mutant formation. Together, this work provides evidence of the utilities of PMBN as a novel potentiator for antibiotics against Gram-negative bacteria and insights for the eradication of bacterial persister cells during antibiotic treatment. IMPORTANCE: The significance of our study lies in addressing the problem of antibiotic-resistant Gram-negative bacteria, which continue to be a global cause of mortality associated with bacterial infections. Therefore, identifying innovative therapeutic approaches is an urgent need. Recent research has highlighted the potential of selective antibacterials like polymyxins, which specifically target the lipopolysaccharides of Gram-negative bacteria. However, the clinical use of polymyxins is limited by their severe cytotoxicity. This study unveils the effectiveness of polymyxin B nonapeptide (PMBN) in significantly enhancing the eradication of persister cells in Gram-negative bacteria. Although PMBN itself does not exhibit antibacterial activity or cytotoxicity, it remarkably reduces persister cells during the treatment of antibiotics. Moreover, combining PMBN with other antibiotics reduces the emergence of resistant mutants. Our research emphasizes the utility of PMBN as a novel potentiator to decrease persister cells during antibiotic treatments for Gram-negative bacteria.
Subject(s)
Bacterial Infections , Gram-Negative Bacterial Infections , Polymyxin B/analogs & derivatives , Humans , Polymyxin B/pharmacology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Polymyxins/chemistry , Polymyxins/pharmacology , Gram-Negative Bacteria , Lipopolysaccharides , Microbial Sensitivity TestsABSTRACT
Background: Bone marrow (BM) involvement is an indicator of a poor prognosis in diffuse large B-cell lymphoma (DLBCL); however, few studies have evaluated the role of immunoglobulin gene rearrangement (IgR) in detecting BM involvement. Methods: We evaluated the clinical characteristics and treatment outcomes of patients with DLBCL based on histological BM involvement or positive BM IgR using polymerase chain reaction or next-generation sequencing. We also investigated the role of consolidative upfront autologous hematopoietic stem cell transplantation (ASCT) in patients with DLBCL and BM involvement. Results: Among 624 patients, 123 (19.7%) with histological BM involvement and 88 (17.5%) with positive IgR in histologically negative BM had more advanced disease characteristics. Overall (OS) and progression-free (PFS) survival was better for patients with negative BM histology and negative IgR than that in patients with histological BM involvement (P = 0.050 and P < 0.001, respectively) and positive IgR with negative BM histology (P = 0.001 and P = 0.005, respectively). Survival rates did not differ among 82 (13.1%) patients who were treated with upfront ASCT and had histological BM involvement or positive IgR with negative BM histology. The survival outcomes were worse for patients who were not treated with upfront ASCT and for those with histological BM involvement or positive IgR, than for those with negative BM histology and negative IgR. Conclusion: Patients diagnosed with DLBCL and BM involvement based on histology or IgR had aggressive clinical features and poor survival. Upfront ASCT mitigated poor prognosis due to BM involvement.
ABSTRACT
OBJECTIVES: Genetic changes in Mycobacterium abscessus during antibiotic treatment are not fully understood. This study aimed to investigate the genetic changes in M. abscessus in patients receiving antibiotic treatment, and their clinical implications. METHODS: Pretreatment and 12-month post-treatment M. abscessus isolates were obtained from patients with M. abscessus pulmonary disease. Isolates from each time point were separated into six groups based on their distinctive morphological characteristics. Twenty-four isolates, comprising 12 from patient A exhibiting progressive disease and 12 from patient B demonstrating stable disease, underwent sequencing. Subsequently, minimal inhibitory concentrations (MICs) for the administered antibiotics were measured. RESULTS: Persistent infection with a single strain was observed in patients A and B. During 12 months of treatment, MICs for administered drugs did not generally change over time in either patient and single nucleotide variations (SNV) associated with antimicrobial resistance (rrl, rrs, erm(41), gyrA, gyrB, whiB7 and hflX) were not mutated. Although not significant, 47 and 52 non-synonymous SNVs occurred in M. abscessus from patients A and B, respectively, and the accumulation of these SNVs differed in patients A and B, except for five SNVs. The most variable positions were within a probable NADH-dependent glutamate synthase gene and a putative YrbE family protein gene in patients A and B, respectively. CONCLUSIONS: Persistent infections by a single strain of M. abscessus were observed in two patients with different clinical courses. Genetic changes in M. abscessus during antibiotic treatment were relatively stable in these patients. CLINICAL TRIALS IDENTIFIER: NCT01616745 (ClinicalTrials.gov ID).
Subject(s)
Lung Diseases , Mycobacterium abscessus , Humans , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Microbial Sensitivity Tests , Mycobacterium abscessus/geneticsABSTRACT
Background: Brentuximab vedotin (BV), a potent antibody-drug conjugate, targets the CD30 antigen. In Korea, BV has been approved for the treatment of relapsed or refractory Hodgkin lymphoma (HL), anaplastic large-cell lymphoma (ALCL), and cutaneous T-cell lymphomas, including mycosis fungoides (MF). However, there are limited data reflecting real-world experiences with BV treatment for HL, ALCL, and MF. Methods: This was a multicenter, non-interventional registry study of the efficacy and safety of BV in patients with relapsed or refractory CD30-positive lymphoma (CISL1803/BRAVO). Outcomes were determined based on the occurrence of relapse or progression and overall survival after BV treatment. Results: A total of 85 patients were enrolled in this study. The median number of BV cycles was 10 (range, 2â16) in the patients with HL. The objective response rate (ORR) of patients with HL to BV was 85.4% (41/48), comprising 27 complete responses (CRs) and 14 partial responses (PRs). The ORR of ALCL was 88% (22/25), consisting of 17 CRs and five PRs, whereas the ORR of MF was 92% (11/12). At the median follow-up of 44.6 months after BV treatment, the median post-BV progression-free survival of HL, ALCL, and MF patients was 23.6 months, 29.0 months, and 16.7 months, respectively (P=0.641). The most common side effect of BV was peripheral neuropathy; 22 patients (25.9%, 22/85) experienced peripheral neuropathy (all grades). Conclusion: The treatment outcomes of patients with relapsed or refractory CD30-positive lymphoma improved with BV treatment, and the safety profile was manageable.
ABSTRACT
Introduction: Pegylated granulocyte colony-stimulating factor (G-CSF) has been widely used for preventing febrile neutropenia in various types of cancer treatment. In the present study, we prospectively evaluated the safety and efficacy of pegfilgrastim as a primary prophylaxis of febrile neutropenia and infection among patients with relapsed refractory multiple myeloma (RRMM) treated with pomalidomide-based regimens. Methods: Thirty-three patients with RRMM who received pomalidomide and dexamethasone (Pd) with or without cyclophosphamide (PCd) were enrolled in this study. Twenty-eight patients were treated with PCd and 5 patients were treated with Pd. All patients were given pegfilgrastim subcutaneously with a single administration performed on the first day of each cycle as primary prophylaxis until the fourth cycle. Results: The median age of the patients was 75 (range 56-85), and the median prior line of therapy was 2 (range 2-6). Seventeen patients (51.5%) had any grade of neutropenia and 20 (60.6%) had any grade of thrombocytopenia before starting pomalidomide treatment. During the 4 cycles of treatment, grade 3 or more neutropenia occurred in 17 patients (51.5%), and 4 (12.1%) experienced grade 3 or more febrile neutropenia. Grade 3 or more infections occurred in 5 patients (15.2%). Interestingly, the patients with markedly increased ANC of more than 2 x 109/L compared to baseline ANC after 7 days of pegfilgrastim at 1st cycle of treatment showed a significantly lower incidence of grade 3-4 neutropenia. The most common adverse event of pegfilgrastim was fatigue, and all the adverse events caused by pegfilgrastim were grade 1 or 2. And there was no significant change in the immune cell population and cytokines during the administration of pegfilgrastim. Discussion: Considering that this study included elderly patients with baseline neutropenia, pegylated G-CSF could be helpful to prevent severe neutropenia, febrile neutropenia, or infection in patients with RRMM.
ABSTRACT
The prevalence of Mycobacterium avium complex-pulmonary disease (MAC-PD) has become a growing concern worldwide, and current treatments involving macrolides (clarithromycin [CLR] or azithromycin), ethambutol, and rifampicin have limited success, highlighting the need for better therapeutic strategies. Recently, oxazolidinone drugs have been identified as novel anti-tuberculosis drugs effective against drug-resistant M. tuberculosis. However, the effects of these drugs against MAC are still controversial due to limited data. Here, we first evaluated the intracellular anti-MAC activities of two oxazolidinone drugs, linezolid (LZD) and delpazolid (DZD), against 10 macrolide-susceptible MAC strains and one macrolide-resistant M. avium strain in murine bone marrow-derived macrophages (BMDMs) and found that both drugs demonstrated similar potential. The synergistic efficacies with CLR were then determined in a chronic progressive MAC-PD murine model by initiating a 4-week treatment at 8 weeks post-infection. Upon assessment of bacterial burdens and inflamed lesions, oxazolidinone drugs exhibited no anti-MAC effect, and there was no significant difference in the synergistic effect of CLR between LZD and DZD. These findings suggest that oxazolidinone drugs inhibit intracellular bacterial growth, even against macrolide-resistant MAC, but their clinical application requires further consideration.
Subject(s)
Lung Diseases , Mycobacterium avium-intracellulare Infection , Oxazolidinones , Humans , Mice , Animals , Mycobacterium avium Complex , Mycobacterium avium-intracellulare Infection/drug therapy , Mycobacterium avium-intracellulare Infection/microbiology , Oxazolidinones/pharmacology , Oxazolidinones/therapeutic use , Anti-Bacterial Agents/pharmacology , Antitubercular Agents/pharmacology , Clarithromycin/therapeutic use , Macrolides/pharmacology , Lung Diseases/drug therapyABSTRACT
Nanoscopic investigation of bacterial cells is essential to reveal their physiological status, impacting all cellular functions. Currently, this requires labeled probes or targeted staining procedures. Herein, we report a new bacterial feature, intracellular dynamics-resolved Rayleigh scattering (IDRS), that visualizes spatiotemporal cytoplasmic transitions in unlabeled bacteria and characterizes their real-time physiological status in 10 s. From single-bacterium IDRS signals, we discovered unique spatial patterns and their multiple transitions in Gram-negative and Gram-positive bacteria. The magnitude of IDRS signal variation highly correlated with the metabolic status of bacteria, differentiating persistent subpopulations. This is also the first report demonstrating distinct real-time metabolic conditions of unlabeled drug-resistant bacteria that are exposed to different doses of antibiotics. Our strategy opens up a way to simultaneously trace in situ metabolic and antibiotic resistance statuses, which can be applied in single-cell level control of bacterial metabolism and efficacy with a heterogeneous nature.
Subject(s)
Anti-Bacterial Agents , Bacteria , Anti-Bacterial Agents/pharmacology , Cytoplasm , Cytosol , Staining and LabelingABSTRACT
BACKGROUND/AIMS: We performed a prospective study to determine the efficacy and safety of rituximab including chemotherapy in CD20-positive acute lymphoblastic leukemia (ALL). METHODS: Patients with newly diagnosed ALL, aged ≥ 15 years, were eligible for the study if their leukemic blast cells in bone marrow expressed CD20 ≥ 20% at the time of diagnosis. Patients received multiagent chemotherapy with rituximab. After achieving complete remission (CR), patients received five cycles of consolidation with concomitant rituximab. Rituximab was administered monthly from day 90 of transplantation for patients who received allogeneic hematopoietic cell transplantation. RESULTS: In patients with Philadelphia (Ph)-negative ALL, 39 of 41 achieved CR (95.1%), the 2- and 4-year relapse-free survival (RFS) rates were 50.4% and 35.7%, and the 2- and 4-year overall survival (OS) rates were 51.5% and 43.2%, respectively. In the group with Ph-positive ALL, all 32 patients achieved CR, the 2- and 4-year RFS rates were 60.7% and 52.1%, and the 2- and 4-year OS rates were 73.3% and 52.3%, respectively. In the Ph-negative ALL group, patients with higher CD20 positivity experienced more favorable RFS (p < 0.001) and OS (p = 0.06) than those with lower CD20 positivity. Patients who received ≥ 2 cycles of rituximab after transplantation had significantly improved RFS (hazard ratio [HR], 0.31; p = 0.049) and OS (HR, 0.29; p = 0.021) compared with those who received < 2 cycles. CONCLUSION: The addition of rituximab to conventional chemotherapy for CD20-positive ALL is effective and tolerable (Clinicaltrials. gov NCT01429610).
Subject(s)
Hematopoietic Stem Cell Transplantation , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Humans , Rituximab/adverse effects , Prospective Studies , Philadelphia Chromosome , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Remission Induction , Antineoplastic Combined Chemotherapy Protocols/adverse effectsABSTRACT
Here, we describe detailed steps to constitute an in vitro assay for monitoring papain-like protease of coronavirus and a cell-based immunofluorescence infection assay. These assays can be adapted for high-throughput screening to determine the efficacy of novel protease inhibitors of coronaviruses and other viruses. In addition, cell-based immunofluorescence infection assay can be used to visually analyze antiviral efficacy of any novel compounds. For complete details on the use and execution of this protocol, please refer to Jeong et al. (2022).1.
ABSTRACT
Background: A chemotherapy of rituximab, fludarabine and cyclophosphamide (R-FC) has been accepted as a promising frontline chemotherapy in selected patients with chronic lymphocytic leukemia (CLL). Although R-FC regimen is a relatively dose-dense regimen and neutropenia incidence is more than 50%, primary prophylactic pegfilgrastim was not fully recommended in the clinical field. Therefore, the study evaluated the prophylactic effectiveness of pegfilgrastim to reduce the incidence of febrile neutropenia associated with R-FC of patients with CLL. Patients and methods: A single-arm, multicenter, prospective phase II study was designed to assess the efficacy of prophylactic pegfilgrastim. Thirty-four CLL patients were enrolled and analyzed for neutropenia and other related factors, and comparative analysis was performed with historical cohort. Results: Compared with our historical cohort, incidence of grade 3-4 neutropenia and febrile neutropenia was remarkably reduced during any cycle of chemotherapy (14.7% vs. 48.2% of study cohort vs. historical cohort during C1, 5.9% vs. 65.8% during C2, 12.9% vs. 80.6% during C3, 10% vs. 84.6% during C4, 3.4% vs. 83.6% during C5, and 10.7% vs. 85.7% during C6, p <0.001). Also, cumulative incidence of disrupted chemotherapy was noticeably reduced in study cohort on any cycles of R-FC regimen (8.8% vs. 22.2% of study cohort vs. historical cohort on C2, 9.7% vs. 25.2% on C3, 13.4% vs. 26.9% on C4, 13.8% vs. 45.2% on C5, 17.9% vs. 47.3% on C6, p=0.007). In addition, treatment-related mortality was 5.9%, which significantly reduced compared to 9.6% of our historical cohort (HR 0.64, 95% CI 0.42-0.79, P = 0.032). Conclusion: Primary prophylactic pegfilgrastim is effective in the prevention of neutropenia/febrile neutropenia, and infection-related mortality during R-FC regimen in patients with CLL.
ABSTRACT
Antibiotic resistance is one of the world's most urgent public health problems, and novel antibiotics to kill drug-resistant bacteria are needed. Natural product-derived small molecules have been the major source of new antibiotics. Here we describe a family of antibacterial metabolites isolated from a probiotic bacterium, Bacillus licheniformis. A cross-streaking assay followed by activity-guided isolation yielded a novel antibacterial metabolite, bacillimidazole G, which possesses a rare imidazolium ring in the structure, showing MIC values of 0.7-2.6 µg/mL against human pathogenic Gram-positive and Gram-negative bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and a lipopolysaccharide (LPS)-lacking Acinetobacter baumannii ΔlpxC. Bacillimidazole G also lowered MICs of colistin, a Gram-negative antibiotic, up to 8-fold against wild-type Escherichia coli MG1655 and A. baumannii. We propose a biosynthetic pathway to the characterized metabolites based on precursor-feeding studies, a chemical biological approach, biomimetic total synthesis, and a biosynthetic gene knockout method.
Subject(s)
Bacillus licheniformis , Methicillin-Resistant Staphylococcus aureus , Humans , Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria , Gram-Positive Bacteria , Microbial Sensitivity TestsABSTRACT
INTRODUCTION: This prospective study aimed to investigate the efficacy and safety of preemptive antiviral therapy with tenofovir disoproxil fumarate (TDF) for HBsAg-positive patients with newly diagnosed diffuse large B-cell lymphoma receiving rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy. METHODS: We enrolled 73 patients from 20 institutions. The primary end point was the absolute risk of hepatitis B virus (HBV)-related hepatitis during preemptive TDF therapy and for 24 weeks after withdrawal from TDF. Hepatitis was defined as a more than 3-fold increase in serum alanine aminotransferase from baseline or an alanine aminotransferase level of ≥100 U/L. HBV-related hepatitis was defined as hepatitis with an increase in serum HBV-DNA to >10 times that of the pre-exacerbation baseline or an absolute increase of ≥20,000 IU/mL compared with the baseline. RESULTS: No patient developed HBV reactivation or HBV-related hepatitis during preemptive antiviral therapy (until 48 weeks after completion of R-CHOP chemotherapy) with TDF. All adverse events were grade 1 or 2. HBV reactivation was reported in 17 (23.3%) patients. All HBV reactivation was developed at a median of 90 days after withdrawal from TDF (range, 37-214 days). Six (8.2%) patients developed HBV-related hepatitis at a median of 88 days after withdrawal from TDF (range, 37-183 days). DISCUSSION: Preemptive TDF therapy in HBsAg-positive patients with diffuse large B-cell lymphoma receiving R-CHOP chemotherapy was safe and effective for preventing HBV-related hepatitis. However, a long-term maintenance strategy of preemptive TDF therapy should be recommended because of the relatively high rate of HBV-related hepatitis after withdrawal from TDF ( ClinicalTrials.gov ID: NCT02354846).
Subject(s)
Hepatitis B, Chronic , Lymphoma, Large B-Cell, Diffuse , Humans , Tenofovir/adverse effects , Rituximab/adverse effects , Vincristine/adverse effects , Prednisone/therapeutic use , Hepatitis B Surface Antigens , Prospective Studies , Alanine Transaminase , Cyclophosphamide/therapeutic use , Doxorubicin/therapeutic use , Hepatitis B virus , Lymphoma, Large B-Cell, Diffuse/drug therapy , Lymphoma, Large B-Cell, Diffuse/chemically induced , Antiviral Agents/therapeutic use , DNA, ViralABSTRACT
The site-selective incorporation of a trifluoromethyl group into biologically active molecules and pharmaceuticals has emerged as a central topic in medicinal chemistry and drug discovery. Herein, we demonstrate the rhodium(III)-catalyzed conjugate addition of ß-trifluoromethylated enones with quinoline N-oxides, which result in the generation of ß-trifluoromethyl-ß'-quinolinated ketones. The reaction proceeds under mild conditions with complete functional group tolerance. The synthetic applicability was showcased by successful gram-scale experiments and valuable synthetic transformations of coupling products.
Subject(s)
Quinolines , Rhodium , Oxides , Rhodium/chemistry , Catalysis , Ketones/chemistryABSTRACT
To identify potent antiviral compounds, we introduced a high-throughput screen platform that can rapidly classify hit compounds according to their target. In our platform, we performed a compound screen using a lentivirus-based pseudovirus presenting a spike protein of coronavirus, and we evaluated the hit compounds using an amplified luminescence proximity homogeneous assay (alpha) test with purified host receptor protein and the receptor binding domain of the viral spike. With our screen platform, we were able to identify both spike-specific compounds (class I) and broad-spectrum antiviral compounds (class II). Among the hit compounds, thiosemicarbazide was identified to be selective to the interaction between the viral spike and its host cell receptor, and we further optimized the binding potency of thiosemicarbazide through modification of the pyridine group. Among the class II compounds, we found raloxifene and amiodarone to be highly potent against human coronaviruses including Middle East respiratory syndrome coronavirus (MERS-CoV), severe acute respiratory syndrome coronavirus (SARS-CoV), and SARS-CoV-2. In particular, using analogs of the benzothiophene moiety, which is also present in raloxifene, we have identified benzothiophene as a novel structural scaffold for broad-spectrum antivirals. This work highlights the strong utility of our screen platform using a pseudovirus assay and an alpha test for rapid identification of potential antiviral compounds and their mechanism of action, which can lead to the accelerated development of therapeutics against newly emerging viral infections.