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1.
Ann Hematol ; 103(3): 843-854, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38006571

RESUMO

Survival rates of patients with Philadelphia chromosome-positive ALL (Ph+ALL) have improved considerably with the introduction of tyrosine kinase inhibitors (TKI); however, hematopoietic stem cell transplantation (HSCT) continues to play an important role. Reduced-intensity conditioning (RIC) regimens have been widely applied particularly for older patients, but their validity for children and adolescents with Ph+ALL has not been investigated. In this study, data from patients receiving HSCT for de novo Ph+ALL in first or second remission at ages younger than 25 years and with a history of pre-HSCT TKI therapy were retrospectively collected through the nationwide registry in Japan. In 265 patients who received myeloablative conditioning (MAC) and 33 patients receiving RIC, 5-year leukemia-free survival (LFS) rates were 67.3% and 79.8%, respectively (p = 0.142). Multivariate analysis of LFS, focusing on patients with good performance status, identified RIC as a significant prognostic factor for LFS (hazard ratio 0.32, p = 0.032), as well as older age, higher leukocyte count at diagnosis, and disease with additional chromosomal abnormalities. These trends were similar when we focused on patients who received prophylactic post-HSCT TKI treatment, as 5-year LFS was 81.0% for MAC and 84.4% for RIC (p = 0.748). In summary, HSCT with RIC regimen showed at least comparable LFS to HSCT with MAC regimen, and RIC was an independent favorable prognostic factor on multivariate analysis adjusting potential prognostic factors. While patient numbers were limited, our data suggest that RIC may be safely applied in this group, particularly combined with prophylactic post-HSCT TKI maintenance therapy.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia-Linfoma Linfoblástico de Células Precursoras , Criança , Humanos , Adolescente , Estudos Retrospectivos , Cromossomo Filadélfia , Doença Aguda , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Condicionamento Pré-Transplante
2.
Langmuir ; 40(16): 8483-8492, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38618876

RESUMO

Recombinant protein production is an essential aspect of biopharmaceutical manufacturing, with Escherichia coli serving as a primary host organism. Protein refolding is vital for protein production; however, conventional refolding methods face challenges such as scale-up limitations and difficulties in controlling protein conformational changes on a millisecond scale. In this study, we demonstrate the novel application of flow microreactors (FMR) in controlling protein conformational changes on a millisecond scale, enabling efficient refolding processes and opening up new avenues in the science of FMR technology. FMR technology has been primarily employed for small-molecule synthesis, but our novel approach successfully expands its application to protein refolding, offering precise control of the buffer pH and solvent content. Using interleukin-6 as a model, the system yielded an impressive 96% pure refolded protein and allowed for gram-scale production. This FMR system allows flash changes in the reaction conditions, effectively circumventing protein aggregation during refolding. To the best of our knowledge, this is the first study to use FMR for protein refolding, which offers a more efficient and scalable method for protein production. The study results highlight the utility of the FMR as a high-throughput screening tool for streamlined scale-up and emphasize the importance of understanding and controlling intermediates in the refolding process. The FMR technique offers a promising approach for enhancing protein refolding efficiency and has demonstrated its potential in streamlining the process from laboratory-scale research to industrial-scale production, making it a game-changing technology in the field.

3.
J Org Chem ; 89(6): 3977-3986, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38407947

RESUMO

A palladium-catalyzed cyclization-carbonylation of 2-alkynyl primary benzamides 1 afforded methyl 3-substituted 1-methoxyisoquinoline-4-carboxylates 6 in good to moderate yields. In the case of mesylate 1r, 12 was obtained directly via a cyclization-carbonylation-cyclization cascade. Compounds 6 were converted to isoquinolin-1(2H)-ones 8 in good yields under microwave irradiation. In the case of the mesylate 6q, tricyclic isoquinolinone 10 was obtained in good yield. The reactions of thiophene-2-carboxamide derivatives also proceeded well.

4.
J Pharmacol Sci ; 154(4): 256-263, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38485343

RESUMO

Platelet-activating factor (PAF) is expected to increase esophageal motility. However, to the best of our knowledge, this has not been examined. Thus, we investigated the contractile effects of PAF on guinea pig (GP) esophageal muscularis mucosae (EMM) and the extracellular Ca2+ influx pathways responsible. PAF (10-9-10-6 M) contracted EMM in a concentration-dependent manner. PAF (10-6 M)-induced contractions were almost completely suppressed by apafant (a PAF receptor antagonist, 3 × 10-5 M). In EMM strips, PAF receptor and PAF-synthesizing/degrading enzyme mRNAs were detected. PAF (10-6 M)-induced contractions were abolished by extracellular Ca2+ removal but were not affected by diltiazem [a voltage-dependent Ca2+ channel (VDCC) inhibitor, 10-5 M]. PAF (10-6 M)-induced contractions in the presence of diltiazem were significantly suppressed by LOE-908 [a receptor-operated Ca2+ channel (ROCC) inhibitor, 3 × 10-5 M], SKF-96365 [an ROCC and store-operated Ca2+ channel (SOCC) inhibitor, 3 × 10-5 M], and LOE-908 plus SKF-96365. Among the tested ROCC/SOCC-related mRNAs, Trpc3, Trpc6, and Trpv4/Orai1, Orai3, and Stim2 were abundantly expressed in EMM strips. These results indicate that PAF potently induces GP EMM contractions that are dependent on extracellular Ca2+ influx through ROCCs/SOCCs, and VDCCs are unlikely to be involved.


Assuntos
Diltiazem , Isoquinolinas , Fator de Ativação de Plaquetas , Cobaias , Animais , Diltiazem/farmacologia , Fator de Ativação de Plaquetas/farmacologia , Acetamidas , Canais de Cálcio/metabolismo , Mucosa/metabolismo , Cálcio/metabolismo
5.
J Pediatr Hematol Oncol ; 46(1): e83-e86, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38063411

RESUMO

Children with trisomy 18 tend to develop hepatoblastoma. Since the introduction of appropriate management for organ malfunction, individuals with trisomy 18 have come to have a longer life expectancy. However, the predisposition to hepatoblastoma becomes a significant issue for the quality of a case. Here, we present a rare multifocal hepatoblastoma involving predominantly Couinaud segments 5 and 7 in a 10-month-old boy with trisomy 18. Though the first-line cisplatin monotherapy resulted in unsatisfactory tumor shrinkage, the second-line neoadjuvant chemotherapy administrating irinotecan and vincristine gave rise to significant tumor reduction in volume, leading to the completion of partial resection of the liver without the microscopic residual disease. The patient has been free from recurrence for 44 months. Because anatomical right hepatectomy can cause circulatory instability, including acute onset of pulmonary hypertension in trisomy 18 patients, physicians should balance treatment benefits and potential adverse effects. Our successful experience utilizing a combination of efficacious and less cardiotoxic neoadjuvant chemotherapy followed by the partial hepatectomy encourages physicians to treat a patient with trisomy 18 and tackle hepatoblastoma with a genetic background.


Assuntos
Hepatoblastoma , Neoplasias Hepáticas , Masculino , Criança , Humanos , Lactente , Hepatoblastoma/terapia , Hepatoblastoma/tratamento farmacológico , Neoplasias Hepáticas/patologia , Síndrome da Trissomía do Cromossomo 18/terapia , Síndrome da Trissomía do Cromossomo 18/tratamento farmacológico , Hepatectomia/efeitos adversos , Trissomia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
6.
Pestic Biochem Physiol ; 199: 105767, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38458676

RESUMO

The Bonin Archipelago is a United Nations Educational, Scientific and Cultural Organization's World Natural Heritage Site in Japan with a unique ecosystem; however, the invasive rodents preying on endemic species have been a significant concern. The anticoagulant rodenticide, diphacinone, sprayed by the Ministry of the Environment, has succeeded; however, its repeated use leads to rodenticide resistance. This study evaluated the sensitivity by in vivo pharmacokinetics/pharmacodynamics (PK/PD) analysis and physiologically-based pharmacokinetic modeling to diphacinone in black rats (Rattus rattus) captured on the Bonin Archipelago in February 2022. The Bonin rats exhibited prolonged coagulation time after diphacinone administration. They recovered earlier than susceptible black rats, indicating that Bonin rats were less susceptible, though there were no genetic mutations in Vkorc1, the target enzyme of diphacinone. After the administration of diphacinone, hepatic expression levels of Fsp1, identified as the vitamin K reductase, was decreased, however, the Bonin rats exhibited the most minor suppression. The PK analysis showed that the excretion capacity of the Bonin rats was lower than that of the resistant black rats. In the PBPK modeling, the resistant black rats showed higher clearance than the Bonin and susceptible black rats due to high hepatic metabolic capacity. The Bonin rats demonstrated slow absorption and relatively low clearance. This study highlighted the reduced rodenticide-sensitive tendency of wild black rats in the Bonin Archipelago at an in vivo phenotype level. At the same time, they do not have known rodenticide resistance mechanisms, such as hepatic metabolic enhancement or Vkorc1 mutations. It is crucial to monitor the biological levels to evaluate rodenticide sensitivity accurately.


Assuntos
Fenindiona/análogos & derivados , Rodenticidas , Ratos , Animais , Rodenticidas/farmacologia , Japão , Ecossistema
8.
Exp Cell Res ; 419(2): 113333, 2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-36030969

RESUMO

Recently, selective androgen receptor modulators (SARMs), which bind to AR and act in a tissue/effect-specific manner, have been developed, but the selective mechanism is not well understood. In this study, we investigated the selective mechanism using the synthetic steroid YK11, which showed AR-mediated gene-selective transactivation. In the AR-positive human breast cancer MDA-MB-453 cells, different patterns of AR-mediated target gene expression and AR recruitment to their enhancer regions were observed between DHT and YK11. A docking study suggested the helices 11 and 12 was moved by the sterically hindered C17-group of YK11. Furthermore, the mutational studies of AR Gln902 and mammalian two-hybrid assays suggested different cofactor recruitment between DHT and YK11. The results of this study suggest that gene selective regulation by SARMs results from differential DNA-binding and/or cofactor recruitment by ligands. These results provide novel insights into the mechanism of action of SARMs.


Assuntos
Neoplasias da Mama , Receptores Androgênicos , Androgênios/farmacologia , Animais , Neoplasias da Mama/genética , DNA , Feminino , Expressão Gênica , Humanos , Mamíferos/genética , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Esteroides
9.
J Pediatr Hematol Oncol ; 45(2): 95-98, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35700350

RESUMO

Multifocal lymphangioendotheliomatosis with thrombocytopenia (MLT) is a rare disease characterized by the presence of multiple cutaneous lesions and bleeding from the gastrointestinal tract with thrombocytopenia. Because of the varied phenotypes and rarity of MLT, a treatment strategy has not been standardized thus far. We describe a case of infantile MLT that did not respond to treatment with propranolol, prednisolone, or vincristine. We successfully treated the patient with everolimus, an inhibitor of the mammalian target of rapamycin. Our case provides the first evidence of the effectiveness of everolimus for the treatment of MLT.


Assuntos
Neoplasias Cutâneas , Trombocitopenia , Humanos , Everolimo , Pele/patologia , Trombocitopenia/patologia , Neoplasias Cutâneas/patologia , Sirolimo
10.
Biol Pharm Bull ; 46(8): 1120-1127, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37532563

RESUMO

To clarify the pharmacological properties of the Na+/Ca2+ exchanger (NCX) inhibitor SEA0400 as an antiarrhythmic agent, we assessed its effects on rapid component of delayed rectifier K+ current (IKr) blocker-induced torsade de pointes (TdP) in isoflurane-anesthetized rabbits. Atrioventricular block was induced in rabbits using a catheter ablation technique, and the monophasic action potential (MAP) of the right ventricle was measured under electrical pacing at 60 beats/min. In non-treated control animals, intravenous administration of low-dose (0.3 mg/kg) or high-dose nifekalant (3 mg/kg) prolonged the MAP duration (MAP90) by 113 ± 11 ms (n = 5) and 237 ± 39 ms (n = 5), respectively, where TdP was induced in 1/5 animals treated with a low dose and in 3/5 animals treated with a high dose of nifekalant. In SEA0400-treated animals, low- and high-dose nifekalant prolonged the MAP90 by 65 ± 13 ms (n = 5) and 230 ± 20 ms (n = 5), respectively. No TdP was induced by the low dose but 1/5 animals treated with a high dose of nifekalant developed TdP. In verapamil-treated animals, low-dose and high-dose nifekalant prolonged MAP90 by 50 ± 12 ms (n = 5) and 147 ± 30 ms (n = 5), respectively, without inducing TdP. These results suggest that SEA0400 has the potential to inhibit low-dose nifekalant-induced TdP by suppressing the MAP-prolonging action of nifekalant, whereas the drug inhibited high-dose nifekalant-induced TdP without affecting the MAP-prolonging action of nifekalant. This may reveal that, in contrast to verapamil, the antiarrhythmic effects of SEA0400 on IKr blocker-induced TdP may be multifaceted, depending on the severity of the proarrhythmogenic conditions present.


Assuntos
Bloqueio Atrioventricular , Síndrome do QT Longo , Torsades de Pointes , Animais , Coelhos , Bloqueio Atrioventricular/induzido quimicamente , Bloqueio Atrioventricular/tratamento farmacológico , Trocador de Sódio e Cálcio , Antiarrítmicos/efeitos adversos , Síndrome do QT Longo/induzido quimicamente , Torsades de Pointes/induzido quimicamente , Torsades de Pointes/tratamento farmacológico , Verapamil/efeitos adversos , Potenciais de Ação
11.
Br J Haematol ; 199(3): 392-400, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36029121

RESUMO

The impact of human leukocyte antigen (HLA) mismatching at the HLA-A, -B, -C, and -DRB1 loci after unrelated bone marrow transplantation in paediatric patients with haematological malignancies has not been fully examined. Here, we analysed patients with haematological malignancies (all aged ≤15 years; n = 1330) who underwent a first unrelated bone marrow transplantation between 1993 and 2017 in Japan. The results show that although an HLA mismatch was significantly associated with a low relapse rate, it was also associated with higher non-relapse mortality. There was a significant association between HLA mismatch and low overall survival. Locus mismatch analysis revealed that, as in adults, an HLA-C mismatch had a significant negative impact on survival; however, in paediatric patients, an HLA-DRB1 mismatch did not have a negative impact, although these HLA mismatch effects are weakened in recent cases. Taken together, the results suggest that an HLA-matched donor should be the first candidate for paediatric patients; however, for patients without a matched sibling or matched unrelated donor, we can select an unrelated donor with a mismatch at HLA-DRB1 if available.


Assuntos
Doença Enxerto-Hospedeiro , Neoplasias Hematológicas , Criança , Humanos , Transplante de Medula Óssea/métodos , Neoplasias Hematológicas/terapia , Teste de Histocompatibilidade , Antígenos HLA , Antígenos HLA-A , Antígenos HLA-C , Cadeias HLA-DRB1/genética , Recidiva Local de Neoplasia , Estudos Retrospectivos , Doadores não Relacionados
12.
Hematol Oncol ; 40(3): 457-468, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35212019

RESUMO

Acute lymphoblastic leukemia (ALL) is the most common cancer during childhood, and some high-risk patients with ALL require hematopoietic stem cell transplantation (HSCT). Mainly due to small patient numbers, studies focusing specifically on children and adolescents with T-cell ALL (T-ALL) are limited. Using a nationwide registry, we retrospectively analyzed data from patients under 20 years old who underwent their first HSCT for T-ALL between 2000 and 2018. As a result, total 484 patients were included, and their median follow-up period was 6.9 years after HSCT for survivors. While patients receiving HSCT at first complete remission (CR) showed relatively good 5-year leukemia free survival (5yLFS, 73.5%), once relapse occurred, their prognosis was much worse (44.4%) even if they attained second remission again (p < 0.001). Among patients receiving HSCT at CR1, grade II-IV acute graft versus host disease was associated with worse overall and LFS than grade 0-I (5yLFS 69.5% vs. 82.1%, p = 0.026) mainly due to high non-relapse mortality. Among those patients, patients receiving related bone marrow transplantation, unrelated bone marrow transplantation, or unrelated cord blood transplantation showed similar survival (5yLFS, 73.2%, 76.3%, and 77.0%, respectively). For patients undergoing cord blood transplantation at CR1, total-body irradiation-based myeloablative conditioning was associated with better 5yLFS than other conditioning regimens (85.4% vs. 62.2%, p = 0.044), as it reduced the risk of relapse. These results indicate that relapsed patients have much less chance of cure, and that identifying patients who require HSCT for cure and offering them HSCT with optimal settings during CR1 are crucial for children and adolescents with T-ALL.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Leucemia-Linfoma Linfoblástico de Células Precursoras , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Adolescente , Adulto , Criança , Doença Enxerto-Hospedeiro/complicações , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/etiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/terapia , Prognóstico , Recidiva , Estudos Retrospectivos , Linfócitos T , Condicionamento Pré-Transplante/métodos , Transplante Homólogo , Adulto Jovem
13.
Pediatr Int ; 63(7): 782-789, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33021000

RESUMO

BACKGROUND: Clonal evolution of malignancy is a complex process related to intratumoral heterogeneity, as recent studies have also demonstrated in rhabdomyosarcoma. The purpose of this study is to present a distinct clonal feature of a case with anaplastic embryonal type rhabdomyosarcoma (ERMS) using molecular analysis. METHODS: A five-year-old girl developed a metastatic pelvic tumor. We cultured neoplastic cells isolated from the biopsy sample. Next, to characterize the current case, we analyzed the biopsy sample, autopsy sample, and established cell line using combined modalities, including histopathological, cytogenetic, and molecular assay. We also undertook the backtrack mutation-specific polymerase chain reaction to reveal clonal composition. RESULTS: The histology of the biopsy sample was consistent with ERMS with focal anaplasia. We established a permanently growing cell line, ICH-ERMS-1, from the biopsy sample. On molecular analysis, the biopsied tissue revealed a missense mutation at codon 245 of TP53. In contrast, the autopsy tumor tissue and the cell line established from the biopsied tissue showed a missense mutation at codon 248. A backtrack study using mutation-specific polymerase chain reaction detected a TP53 codon 248 mutation in the original biopsy sample. All the specimens examined had a missense mutation at PTPN11 codon 69. CONCLUSIONS: This study highlights intratumoral heterogeneity and distinct clonal change related to the functional context in our anaplastic ERMS case, supporting the concept of intratumoral heterogeneity and clonal evolution. It requires further case collection to reveal whether p14ARF-p53-MDM2 tumor suppressor pathway alteration, considered a late event in ERMS tumorigenesis, is responsible for anaplasia in ERMS.


Assuntos
Rabdomiossarcoma Alveolar , Rabdomiossarcoma Embrionário , Rabdomiossarcoma , Pré-Escolar , Evolução Clonal , Feminino , Humanos , Mutação , Reação em Cadeia da Polimerase , Rabdomiossarcoma Embrionário/diagnóstico , Rabdomiossarcoma Embrionário/genética
14.
Biol Blood Marrow Transplant ; 25(8): 1597-1602, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31002992

RESUMO

Hematologic stem cell transplantation (HSCT) is the most potent consolidation therapy for high-risk acute lymphoblastic leukemia (ALL), but their outcomes and complications in adolescent and young adult (AYA) patients remain unclear. We compared outcomes after HSCT for ALL among children (age 1 to 9 years; n = 607), adolescents (age 10 to 19 years; n = 783), and young adults (age 20 to 29 years old, n = 603), based on Japanese nationwide registry data. The 5-year overall survival (OS) rate among AYA patients was worse than that of children, at 64% (95% confidence interval [CI], 60% to 68%). In the AYA, the 5-year treatment-related mortality (TRM) after HSCT was 19% (95% CI, 16% to 22%), significantly higher than that in younger patients. The most common cause of TRM in the AYA was infection. The relapse rate was not different across the 3 age groups. When focusing on older adolescents (age 15 to 19 years), there was no difference in outcomes between those treated in pediatric centers and those treated in adult centers. In conclusion, the AYA had a greater risk of nonrelapse death than younger patients, and infection was the most common cause. Further optimization is required for HSCT in AYAs with ALL.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Sistema de Registros , Adolescente , Adulto , Fatores Etários , Aloenxertos , Criança , Pré-Escolar , Intervalo Livre de Doença , Humanos , Lactente , Masculino , Taxa de Sobrevida , Fatores de Tempo , Adulto Jovem
16.
Chemistry ; 25(3): 733-737, 2019 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-30412336

RESUMO

The first example of an asymmetric cyclization-dimerization of (ortho-alkynyl phenyl) (methoxymethyl) sulfides with a palladium(II) bisoxazoline (box) catalyst has been developed. The box ligand enhances the alkynophilicity of benzothienyl palladium(II) intermediate A and thus promotes coordination of the second alkyne substrate, leading to the dimerization. The characteristic properties of the box ligand were supported by density functional theory (DFT) calculations of the intermediate. Axially chiral bibenzothiophenes were obtained in good yields with good enantioselectivities.

17.
J Org Chem ; 84(24): 16268-16277, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31789031

RESUMO

The first total synthesis of (-)-graminin A is described. Key features of our synthetic approach involve a palladium-catalyzed asymmetric cyclization carbonylation of prochiral propargylic acetate, conversion of the orthoester product into methyl 4-oxo-3-furancarboxylate, and copper complex-mediated aldol condensation of (+)-gregatin B bearing a diene moiety. A new synthesis of (+)-gregatin B and the first synthesis of (-)-graminin A were achieved.

18.
Org Biomol Chem ; 17(28): 6860-6865, 2019 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-31268111

RESUMO

The PdII catalyzed carbonylation of allenyl ketones has been investigated. Carbonylative dimerization predominantly proceeded to afford bis(3-furanyl)methanones 2 as the major products. The use of DMSO strikingly changed the course of the reaction, affording methyl 3-furancarboxylates 3 as the major products. DFT calculations revealed that DMSO stabilized the methanol-coordinated intermediate, leading to methoxycarbonylation. Substituted furans 2 and 3 were selectively synthesized from the same allenyl ketone substrate.

20.
J Infect Chemother ; 25(4): 273-280, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30713034

RESUMO

In light of the increasing number of clinical cases resistant to traditional monotherapies and the lack of novel antimicrobial agents, combination therapy is an appealing solution for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. Here, we evaluated the efficacy of anti-MRSA agents, such as vancomycin (VAN), daptomycin (DAP), and linezolid (LZD), in conjunction with 13 beta-lactams and non-beta-lactams. We assessed the in vitro activities of the various combinations against 40 MRSA strains based on the maximum synergistic effect (MSE), an index calculated from the MIC change with a combination agent. Nearly all the anti-MRSA agents, which were combined with beta-lactams as well as VAN and DAP, showed a synergistic effect with arbekacin. VAN also exhibited varying degrees of synergy depending on the type of beta-lactam, whereas DAP and LZD showed similar synergy with different beta-lactams. These effects were confirmed by antibiotic kill curves, except for the apparent interaction between LZD and beta-lactams. The MSE results were analyzed according to strain characteristics including susceptibility to combination agents, staphylococcal cassette chromosome mec type, and presence of the blaZ gene; however, no obvious correlations were observed. In a fluorescence binding assay, the fluorescence intensity of boron-dipyrromethene (BODIPY)-VAN decreased, whereas that of BODIPY-DAP increased in combination with a beta-lactam agent. These findings suggest that beta-lactam combinations are promising treatment options for MRSA infections and that the type of beta-lactam combined with VAN is important for the synergistic effect.


Assuntos
Antibacterianos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/tratamento farmacológico , beta-Lactamas/farmacologia , Antibacterianos/uso terapêutico , Daptomicina/farmacologia , Daptomicina/uso terapêutico , Sinergismo Farmacológico , Quimioterapia Combinada/métodos , Humanos , Linezolida/farmacologia , Linezolida/uso terapêutico , Resistência a Meticilina/efeitos dos fármacos , Resistência a Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/microbiologia , Vancomicina/farmacologia , Vancomicina/uso terapêutico , beta-Lactamas/uso terapêutico
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