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1.
Respir Investig ; 62(3): 388-394, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38460356

RESUMO

BACKGROUND: The antifibrotic agents pirfenidone and nintedanib have been shown to be effective in patients with idiopathic pulmonary fibrosis (IPF). However, discontinuation of antifibrotic drugs is a major clinical concern because of the lack of alternative treatment options. Therefore, we identified factors that may be useful for predicting the termination of antifibrotic agents. METHODS: We retrospectively recruited 280 IPF patients treated with antifibrotic drugs between 2009 and 2018 from seven regional core hospitals in Gunma prefecture, Japan. RESULTS: At four months, the short-term discontinuation group exhibited a significantly worse prognosis in the pirfenidone group and a poorer prognosis in the nintedanib group compared to that in the continuation group. The discontinuation group of pirfenidone at 4 months exhibited lower albumin and higher C-reactive protein (CRP) levels in the sera compared to the group that continued treatment for more than 4 months. In multivariate analysis, the Glasgow prognostic score (GPS), well known as a predictor of cancer prognosis, which comprises serum CRP and albumin levels, predicted early discontinuation and prognosis in the pirfenidone group, whereas the body mass index (BMI) predicted early discontinuation of nintedanib. A high GPS, with both albumin <3.5 g/dL and CRP >1.0 mg/dL, was associated with a poorer prognosis in the pirfenidone group. CONCLUSION: GPS and BMI were significant factors for short-term pirfenidone and nintedanib discontinuation, respectively. Initial evaluation of GPS and BMI prior to antifibrotic therapy may contribute to less interrupted IPF management, thus leading to better prognostic outcomes in patients with IPF.


Assuntos
Antifibróticos , Fibrose Pulmonar Idiopática , Indóis , Humanos , Índice de Massa Corporal , Prognóstico , Estudos Retrospectivos , Resultado do Tratamento , Fibrose Pulmonar Idiopática/induzido quimicamente , Piridonas/uso terapêutico , Albuminas
2.
Int J Hematol ; 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38526684

RESUMO

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by a lack of behavioral flexibility and stereotyped language. Food selectivity is common among children with ASD because of their persnickety nature. A prolonged unbalanced diet results in an increased risk of several diseases, such as iron deficiency anemia, scurvy, rickets, dry eye, and Wernicke encephalopathy. However, no cases of megaloblastic anemia have been reported to date. We report the case of an 11-year-old boy with ASD who developed megaloblastic anemia due to vitamin B12 deficiency. He had a prolonged history of selective eating for more than 10 years. His nutritional status on admission was poor, and he had low weight and short stature. His food selectivity was so strong that intervention to expand diet variety was unsuccessful. A developmental-behavioral pediatrician found that the patient had visual dominance and could take some medications when suffering from a minor illness. Nutritional supplements were selected after consultation with a nutritionist. Although compulsory treatment was necessary during the acute phase, the therapy was continued at home. With multidisciplinary intervention tailored to the patient and his parents' characteristics, his nutritional status improved in a few months.

3.
Microvasc Res ; 152: 104627, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-37963515

RESUMO

AIMS: Protein kinase D (PKD), once considered an effector of protein kinase C (PKC), now plays many pathophysiological roles in various tissues. However, little is known about role of PKD in vascular function. We investigated the role of PKD in contraction of rat aorta and human aortic smooth muscle cells (HASMCs) and in haemodynamics in rats. METHODS AND RESULTS: Isometric tension of rat aortic was measured to examine norepinephrine-induced contraction in the presence of PKD, PKC and Rho-kinase inhibitors. Phosphorylation of PKD1, myosin targeting subunit-1 (MYPT1), myosin light chain (MLC), CPI-17 and heat-shock protein 27 (HSP27), and actin polymerization were measured in the aorta. Phosphorylation of MYPT1 and MLC was also measured in HASMCs knocked down with specific siRNAs of PKD 1, 2 and 3. Intracellular calcium concentrations and cell shortening were measured in HASMCs. Norepinephrine-induced aortic contraction was accompanied by increased phosphorylation of PKD1, MYPT1 and MLC and actin polymerization, all of which were attenuated with PKD inhibitor CRT0066101. PKD1 phosphorylation was not inhibited by PKC inhibitor, chelerythrine or Rho kinase inhibitor, fasudil. In HASMCs, the phosphorylation of MYPT1 and MLC was attenuated by PKD1, but not PKD2, 3 knockdown. In HASMCs, CRT0066101 inhibited norepinephrine-induced cell shortening without affecting calcium concentration. Administration of CRT0066101 decreased systemic vascular resistance and blood pressure without affecting cardiac output in rats. CONCLUSIONS: PKD1 may play roles in aorta contraction and haemodynamics via phosphorylation of MYPT1 and actin polymerization in a calcium-independent manner.


Assuntos
Actinas , Vasoconstrição , Animais , Humanos , Ratos , Actinas/metabolismo , Cálcio/metabolismo , Contração Muscular , Músculo Liso Vascular/metabolismo , Cadeias Leves de Miosina/metabolismo , Norepinefrina/farmacologia , Norepinefrina/metabolismo , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , Quinases Associadas a rho/metabolismo
4.
Nutrients ; 15(1)2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36615878

RESUMO

High-intensity exercise in athletes results in mainly the production of excess reactive oxygen species (ROS) in skeletal muscle, and thus athletes should maintain greater ROS scavenging activity in the body. We investigated the changes in six different ROS-scavenging activities in athletes following high-intensity anaerobic exercise. A 30-s Wingate exercise test as a form of high-intensity anaerobic exercise was completed by 10 male university track and field team members. Blood samples were collected before and after the exercise, and the ROS-scavenging activities (OH•, O2•−, 1O2, RO• and ROO•, and CH3•) were evaluated by the electron spin resonance (ESR) spin-trapping method. The anaerobic exercise significantly increased RO• and ROO• scavenging activities, and the total area of the radar chart in the ROS-scavenging activities increased 178% from that in pre-exercise. A significant correlation between the mean power of the anaerobic exercise and the 1O2 scavenging activity was revealed (r = 0.72, p < 0.05). The increase ratio in OH• scavenging activity after high-intensity exercise was significantly greater in the higher mean-power group compared to the lower mean-power group (n = 5, each). These results suggest that (i) the scavenging activities of some ROS are increased immediately after high-intensity anaerobic exercise, and (ii) an individual's OH• scavenging activity responsiveness may be related to his anaerobic exercise performance. In addition, greater pre-exercise 1O2 scavenging activity might lead to the generation of higher mean power in high-intensity anaerobic exercise.


Assuntos
Atletas , Exercício Físico , Humanos , Masculino , Espécies Reativas de Oxigênio , Anaerobiose , Radicais Livres , Oxigênio , Teste de Esforço
5.
Thorac Cancer ; 13(22): 3225-3228, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36193787

RESUMO

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors are standard therapeutic agents for non-small cell lung cancer (NSCLC) patients with major EGFR mutations such as exon 19 deletions and a L858R mutation, whereas treatment strategies for cases with uncommon EGFR mutations remain to be fully established. Here, we report a long-term (≥20 years from initial diagnosis) NSCLC survivor carrying EGFR L858R and L747V mutations. The patient received gefitinib monotherapy, systemic chemotherapy/chemoimmunotherapy, and local consolidative therapies for oligometastatic lesions, and responded to afatinib rechallenge with a progression-free survival of 12 months. The current case suggests that afatinib is effective in NSCLC patients with EGFR L858R and L747V mutations and that a therapeutic approach combining appropriately timed systemic therapies with local consolidative therapies for oligometastatic lesions improves long-term survival.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Afatinib/farmacologia , Afatinib/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Receptores ErbB , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Mutação , Sobreviventes
6.
Cells ; 11(1)2022 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-35011705

RESUMO

Antifibrotic agents have been widely used in patients with idiopathic pulmonary fibrosis (IPF). Long-term continuation of antifibrotic therapy is required for IPF treatment to prevent disease progression. However, antifibrotic treatment has considerable adverse events, and the continuation of treatment is uncertain in many cases. Therefore, we examined and compared the continuity of treatment between pirfenidone and nintedanib in patients with IPF. We retrospectively enrolled 261 consecutive IPF patients who received antifibrotic treatment from six core facilities in Gunma Prefecture from 2009 to 2018. Among them, 77 patients were excluded if the antifibrotic agent was switched or if the observation period was less than a year. In this study, 134 patients treated with pirfenidone and 50 treated with nintedanib were analyzed. There was no significant difference in patient background, discontinuation rate of antifibrotic treatment over time, and survival rate between the two groups. However, the discontinuation rate due to adverse events within one year of antifibrotic treatment was significantly higher in the nintedanib group than in the pirfenidone group (76% vs. 37%, p < 0.001). Furthermore, the discontinuation rate due to adverse events in nintedanib was higher than that of pirfenidone treatment throughout the observation period (70.6% vs. 31.2%, p = 0.016). The pirfenidone group tended to be discontinued due to acute exacerbation or transfer to another facility. The results of this study suggest that better management of adverse events with nintedanib leads to more continuous treatment that prevents disease progression and acute exacerbations, thus improving prognosis in patients with IPF.


Assuntos
Antineoplásicos/uso terapêutico , Fibrose Pulmonar Idiopática/tratamento farmacológico , Indóis/uso terapêutico , Piridonas/uso terapêutico , Antineoplásicos/farmacologia , Progressão da Doença , Humanos , Indóis/farmacologia , Prognóstico , Piridonas/farmacologia , Resultado do Tratamento
7.
Radiol Case Rep ; 16(11): 3504-3508, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34422150

RESUMO

Coronavirus disease 2019 (COVID-19) has become a global pandemic since its discovery in December 2019, and as the disease continues to evolve, varying complications associated with it continue to arise. In this regard, computed tomography has played an extremely important role in the diagnosis and evaluation of COVID-19 pneumonia and its complications. We encountered a case of a male patient with neurofibromatosis (type I) who developed concurrent pneumothorax and pleural effusion during his recovery period from severe COVID-19 pneumonia. Pulmonary fibrosis and emphysema were also confirmed. Furthermore, an eosinophil pleural effusion appeared and was prolonged during the healing process of COVID-19. This clinical presentation suggests that fibrosis and emphysema formation due to neurofibromatosis may have caused pneumothorax and pleural effusion.

8.
Clin Rheumatol ; 38(12): 3443-3450, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31420814

RESUMO

BACKGROUND: Dermatomyositis (DM) with autoantibody against melanoma differentiation-associated gene-5 (MDA5) is characterized by elevated risk of rapidly progressive interstitial lung disease (RP-ILD) with a potentially fatal course. Pneumomediastinum (PNM) is a common pulmonary manifestation which accompanies ILD. However, the clinical features of the patients with anti-MDA5 antibody-positive DM who develop PNM remain unclear. METHODS: We retrospectively examined 31 patients with DM having anti-MDA5 antibody and compared the clinical features between patients with PNM (PMN(+)) (n = 11) and those without (PNM(-) (n = 20). In addition, we evaluated the treatment-related prognoses in PNM(+) group. RESULTS: CT score (total ground-glass opacity (GGO) score, P = 0.02; total fibrosis score, P = 0.02) before treatment, and mortality (P = 0.04) were significantly higher in PNM(+) group. The cumulative survival rate as assessed by Kaplan-Meier method was significantly lower for the PNM(+) group (P = 0.02). Among 11 PMN(+) patients, 9 patients (9/11, 81.8%) underwent intensive immunosuppression therapy for RP-ILD, and 5 patients (5/11, 45.5%) did not respond to it and died from the respiratory failure. At the time of diagnosis of PNM, nonsurvivors had worse liver function (ALT, P = 0.03; LDH, P = 0.01), worse respiratory status (A-aDO2, P = 0.01), and worse CT score (total GGO score, P < 0.01). CONCLUSIONS: A subgroup of patients with DM having anti-MDA5 antibody complicated by PNM as well as RP-ILD did respond to intensive immunosuppression therapy. Initial aggressive immunosuppressive therapy should be considered for these patients.Key Points• This study clearly demonstrate the presence of PNM was associated with elevated risk of death due to respiratory failure from RP-ILD among patients with DM having circulating anti-MDA5-antibody.•This study demonstrate evaluation of CT image may be helpful to find patients with better response to the intense immunosuppression therapy for the patients with DM having circulating anti-MDA5-antibody and PNM.


Assuntos
Dermatomiosite/complicações , Helicase IFIH1 Induzida por Interferon/imunologia , Enfisema Mediastínico/etiologia , Adulto , Idoso , Dermatomiosite/diagnóstico , Dermatomiosite/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos
9.
J Nippon Med Sch ; 85(5): 291-296, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30464148

RESUMO

A 69-year-old woman was diagnosed with sarcoidosis, which was not treated with corticosteroid therapy. Her levels of angiotensin converting enzyme decreased significantly over 4 years and a mass lesion was detected near the lower part of her left main bronchus, and diagnosed as small cell lung cancer (SCLC). Treatment of the SCLC with a series of chemotherapeutic agents produced excellent results. The pulmonary sarcoidosis did not show any deterioration despite the frequent use of amrubicin, which is known to be a cause of interstitial pneumonia. This is a case report of SCLC complicated with sarcoidosis in a stage of spontaneous remission, possibly suggesting an association between sarcoidosis and tumor immunity, since recent reports have suggested that immune checkpoint inhibitors might be involved in the development of sarcoidosis.


Assuntos
Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/tratamento farmacológico , Sarcoidose Pulmonar/etiologia , Carcinoma de Pequenas Células do Pulmão/complicações , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Idoso , Antraciclinas/efeitos adversos , Antraciclinas/uso terapêutico , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Feminino , Humanos , Ipilimumab/efeitos adversos , Ipilimumab/uso terapêutico , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/imunologia , Tomografia por Emissão de Pósitrons , Remissão Espontânea , Carcinoma de Pequenas Células do Pulmão/diagnóstico por imagem , Carcinoma de Pequenas Células do Pulmão/imunologia
10.
Respir Med ; 140: 1-5, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29957268

RESUMO

BACKGROUND: Anti-melanoma differentiation-associated gene 5 (MDA5) autoantibodies have been identified as myositis-specific autoantibodies that are often associated with clinically amyopathic dermatomyositis (CADM) and a poor prognosis due to rapidly progressive interstitial lung disease (RP-ILD) in East Asian patients. Besides anti-MDA5 autoantibodies, patients with CADM may have myositis-associated autoantibodies (MAAs), which characterize other connective tissue diseases such as rheumatoid arthritis and Sjögren's syndrome. However, the clinical significance of the coexistence of anti-MDA5 autoantibodies and MAAs in patients with CADM remains unclear. METHODS: We retrospectively analyzed 24 patients with CADM who had anti-MDA5 autoantibodies. Their clinical phenotypes including laboratory test results, high-resolution lung computed tomography data, response to therapy, and prognosis were compared between those who were positive and negative for MAAs, such as antinuclear antibody (ANA), anti-cyclic citrullinated peptide (CCP), anti-SSA, and anti-SSB antibodies. RESULTS: Among 24 patients, 9 (37.5%) additionally had at least one of the MAAs examined in this study: 1 patient was positive for ANA, 5 for anti-CCP, 5 for either anti-SSA or anti-SSB, 1 for anti-cardiolipin, and 1 for anti-Scl-70. Although all anti-MDA5-positive patients with CADM had ILD, the MAA-positive patients showed a lower risk of developing RP-ILD (p = 0.03), a more favorable response to combination therapy of corticosteroids and immunosuppressive agents, and a lower mortality rate than patients with no MAAs (p = 0.03). CONCLUSIONS: Our data suggest that anti-MDA5-positive patients with CADM who also have MAAs have a better prognosis than those without MAAs; thus, anti-MDA5 autoantibodies by themselves may not be strong predictors of worse clinical outcomes in patients with CADM. Coexistent MAAs could be biomarkers for a favorable prognosis in anti-MDA5-positive patients with CADM.


Assuntos
Autoanticorpos/sangue , Dermatomiosite/diagnóstico , Helicase IFIH1 Induzida por Interferon/imunologia , Adulto , Idoso , Biomarcadores/sangue , Dermatomiosite/tratamento farmacológico , Dermatomiosite/imunologia , Progressão da Doença , Feminino , Glucocorticoides/uso terapêutico , Humanos , Imunossupressores/uso terapêutico , Estimativa de Kaplan-Meier , Doenças Pulmonares Intersticiais/diagnóstico , Doenças Pulmonares Intersticiais/tratamento farmacológico , Doenças Pulmonares Intersticiais/imunologia , Masculino , Pessoa de Meia-Idade , Miosite/imunologia , Prognóstico , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
11.
Intern Med ; 57(2): 247-251, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29093389

RESUMO

A 66-year-old man had been treated with prednisolone for eosinophilic pneumonia for 8 years. His slowly progressing cough and dyspnea were accompanied by elevated levels of fibrotic serological markers and an increased reticular shadow on chest computed tomography images. The patient had recently tested positive for anti-EJ antibodies, a type of anti-aminoacyl-tRNA synthetase antibody; therefore, we diagnosed him with an exacerbation of interstitial pneumonia due to anti-synthetase syndrome (ASS). He was treated with tacrolimus and an increased prednisolone dosage. We herein present the first reported case of eosinophilic pneumonia preceding anti-EJ antibody-positive ASS.


Assuntos
Aminoacil-tRNA Sintetases/imunologia , Doenças Pulmonares Intersticiais/complicações , Doenças Pulmonares Intersticiais/imunologia , Eosinofilia Pulmonar/complicações , Autoanticorpos , Tosse/complicações , Dispneia/complicações , Humanos , Doenças Pulmonares Intersticiais/diagnóstico , Masculino , Pessoa de Meia-Idade , Síndrome , Tomografia Computadorizada por Raios X
12.
Intern Med ; 56(20): 2753-2757, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28924112

RESUMO

A 41-year-old woman treated with isoniazid (INH) for latent tuberculosis infection and an oral corticosteroid for sarcoidosis developed severe anemia two months after initiating INH. A bone marrow examination showed erythroblastopenia, and a diagnosis of INH-induced pure red cell aplasia (PRCA) was made. Her reticulocyte count and hemoglobin levels improved two weeks after discontinuation of INH. A literature review of INH-induced PRCA shows that it occurs very rarely in the context of autoimmune disorders. This report describes a case of INH-induced PRCA occurring in a patient with sarcoidosis.


Assuntos
Antituberculosos/administração & dosagem , Isoniazida/efeitos adversos , Tuberculose Latente/tratamento farmacológico , Aplasia Pura de Série Vermelha/induzido quimicamente , Corticosteroides/uso terapêutico , Adulto , Antituberculosos/uso terapêutico , Feminino , Humanos , Isoniazida/uso terapêutico , Tuberculose Latente/complicações , Sarcoidose/complicações , Sarcoidose/tratamento farmacológico
13.
J Med Chem ; 53(6): 2528-33, 2010 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-20180534

RESUMO

Novel semisynthetic vancomycin derivatives with antibacterial activity against vancomycin-resistant S. aureus (VRSA) were prepared. Replacement of Cl groups of vancomycin by Suzuki-Miyaura cross-coupling reaction, which gave the title compounds, is described for the first time. Introduction of a carbon substituent at the amino acid residue 2 of vancomycin led to an enhancement of antibacterial activity against vancomycin-resistant strains, whereas the additional introduction at the amino acid residue 6 resulted in a reduction in activity even against vancomycin-susceptible strains.


Assuntos
Bactérias/efeitos dos fármacos , Resistência a Vancomicina/efeitos dos fármacos , Vancomicina/química , Vancomicina/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/crescimento & desenvolvimento , Descoberta de Drogas , Testes de Sensibilidade Microbiana , Modelos Químicos , Estrutura Molecular , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Vancomicina/síntese química
14.
J Am Chem Soc ; 128(36): 11977-84, 2006 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-16953639

RESUMO

Amphotericin B (AmB 1) is known to assemble and form an ion channel across biomembranes. We have recently reported that conformation-restricted derivatives of AmB 2-4 show different ergosterol preferences in ion-channel assays, which suggested that the orientation of the mycosamine strongly affects the sterol selectivity of AmB. The data allowed us to assume that compound 3 showing the highest selectivity would reflect the active conformation of AmB in the channel assembly. In this study, to gain further insight into the active conformation of AmB, we prepared a new intramolecular-bridged derivative 5, where the linker encompassed a hydrophilic glycine moiety. The derivative has almost equivalent ion-channel activity to those of AmB and 3. The antifungal activity of 5 compared with 3 improves significantly, possibly because the increasing hydrophilicity in the linker enhances the penetrability through the fungal cell wall. Conformation of 5 was well converged and very similar to that of 3, thus further supporting the notion that the conformations of these derivatives reproduce the active structure of AmB in the channel complex. Then we used the derivative to probe the mobility of AmB in the membrane by solid-state NMR. To measure dipolar couplings and chemical shift anisotropies, we incorporated [1-(13)C,(15)N]glycine into the linker. The results indicate that 5 is mostly immobilized in ergosterol-containing DMPC bilayers, implying formation of large aggregates of 5. Meanwhile some fraction of 5 remains mobile in sterol-free DMPC bilayers, suggesting promotion of AmB aggregation by ergosterol.


Assuntos
Anfotericina B/química , Ergosterol/química , Bicamadas Lipídicas/química , Anfotericina B/metabolismo , Dimiristoilfosfatidilcolina/química , Ergosterol/metabolismo , Canais Iônicos/química , Canais Iônicos/metabolismo , Bicamadas Lipídicas/metabolismo , Lipossomos/química , Modelos Moleculares , Conformação Molecular , Ressonância Magnética Nuclear Biomolecular , Potássio/química , Potássio/metabolismo
15.
J Am Chem Soc ; 127(30): 10667-75, 2005 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-16045354

RESUMO

Amphotericin B (AmB 1) is known to assemble together and form an ion channel across biomembranes. The antibiotic consists of mycosamine and macrolactone moieties, whose relative geometry is speculated to be determinant for the drug's channel activity and sterol selectivity. To better understand the relationship between the amino-sugar orientation and drug's activity, we prepared conformation-restricted derivatives 2-4, in which the amino and carboxyl groups were bridged together with various lengths of alkyl chains. K+ influx assays across the lipid-bilayer membrane revealed that ergosterol selectivity was markedly different among derivatives; short-bridged derivative 2 almost lost the selectivity, while 3 showed higher ergosterol preference than AmB itself. Monte Carlo conformational analysis of 2-4 based on NOE-derived distances indicated that the amino-sugar moiety of 2 comes close to C41 because of the short bridge, whereas those of 3 and 4 are pointing outward. The mutual orientation of the amino-sugar moiety and macrolide ring is so rigid in derivatives 2 and 3 that these conformations should be unchanged upon complex formation in lipid membranes. These results strongly suggest that the large difference in sterol preference between derivatives 2 and 3 is ascribed to the different orientation of amino-sugar moieties. These findings allowed us to propose a simple model accounting for AmB-sterol interactions, in which hydrogen bonding between 2'-OH of AmB and 3beta-OH of ergosterol plays an important role.


Assuntos
Anfotericina B/química , Anfotericina B/farmacologia , Ergosterol/química , Hexosaminas/química , Hexosaminas/farmacologia , Anfotericina B/metabolismo , Antifúngicos/química , Antifúngicos/farmacologia , Aspergillus niger/efeitos dos fármacos , Ergosterol/metabolismo , Eritrócitos/efeitos dos fármacos , Humanos , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Lipossomos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Conformação Molecular , Ressonância Magnética Nuclear Biomolecular , Potássio/metabolismo , Relação Estrutura-Atividade
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