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1.
Infect Genet Evol ; 118: 105560, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38262571

RESUMO

OBJECTIVES: Given the limited research and its potential hazards, the study aimed to determine the prevalence of Mediterranean spotted fever (MSF) caused by Rickettsia conorii (R. conorii), a tick-borne disease, in Yunnan Province, China. METHODS: Through stratified sampling across five distinct regions in Yunnan, 5358 blood samples were obtained from the general healthy population. Enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence assay (IFA), and Polymerase chain reaction (PCR) were employed for analysis. RESULTS: IFA identified 27 (0.50%) subjects with immunoglobulin G (IgG) positivity; none were positive for immunoglobulin M (IgM) via ELISA. PCR detected one individual with R. conorii outer membrane protein A (ompA). Significant seroprevalence variation was observed, particularly in Southern Yunnan (P = 0.032), with R. conorii subsp. conorii confirmed in the PCR-positive sample. CONCLUSIONS: This research reveals a correlation between MSF prevalence, geography, and climate in Yunnan. The paucity of prior studies underscores MSF's potential diagnostic challenges in the region. Comprehensive understanding of the pathogen's distribution is pivotal for intervention. Given the study's scope and Yunnan's unique setting, additional research is advocated.


Assuntos
Febre Botonosa , Rickettsia , Humanos , Febre Botonosa/epidemiologia , Febre Botonosa/diagnóstico , Estudos Soroepidemiológicos , China/epidemiologia
2.
J Neuropathol Exp Neurol ; 82(11): 894-900, 2023 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-37769321

RESUMO

The morbidity and mortality associated with Alzheimer disease (AD), one of the most common neurodegenerative diseases, are increasing each year. Although both amyloid ß and tau proteins are known to be involved in AD pathology, their detailed functions in the pathogenesis of the disease are not fully understood. There is increasing evidence that neuroinflammation contributes to the development and progression of AD, with astrocytes, microglia, and the cytokines and chemokines they secrete acting coordinately in these processes. Signaling involving chemokine (C-C motif) ligand 5 (CCL5) and its main receptor C-C chemokine receptor 5 (CCR5) plays an important role in normal physiologic processes as well as pathologic conditions such as neurodegeneration. In recent years, many studies have shown that the CCL5/CCR5 axis plays a major effect in the pathogenesis of AD, but there are also a few studies that contradict this. In short, the role of CCL5/CCR5 axis in the pathogenesis of AD is still intricate. This review summarizes the structure, distribution, physiologic functions of the CCL5/CCR5 axis, and the progress in understanding its involvement in the pathogenesis of AD.


Assuntos
Doença de Alzheimer , Quimiocina CCL5 , Humanos , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides , Quimiocina CCL5/metabolismo , Quimiocinas , Receptores CCR5/metabolismo , Receptores de Quimiocinas/metabolismo
3.
J Infect ; 86(4): 338-351, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36796681

RESUMO

OBJECTIVE: The World Health Organization (WHO) recommends multidrug therapy (MDT) with rifampicin, dapsone, and clofazimine for treating leprosy, which is based on very low-quality evidence. Here, we performed a network meta-analysis (NMA) to produce quantitative evidence to strengthen current WHO recommendations. METHOD: All studies were obtained from Embase and PubMed from the date of establishment to October 9, 2021. Data were synthesized with frequentist random-effects network meta-analyses. Outcomes were assessed using odds ratios (ORs), 95% confidence intervals (95% CIs), and P score. RESULTS: Sixty controlled clinical trials and 9256 patients were included. MDT was effective (range of OR: 1.06-1255584.25) for treating leprosy and multibacillary leprosy. Six treatments (Range of OR: 1.199-4.50) were more effective than MDT. Clofazimine (P score=0.9141) and dapsone+rifampicin (P score=0.8785) were effective for treating type 2 leprosy reaction. There were no significant differences in the safety of any of the tested drug regimens. CONCLUSIONS: The WHO MDT is effective for treating leprosy and multibacillary leprosy, but it may not be effective enough. Pefloxacin and ofloxacin may be good adjunct drugs for increasing MDT efficacy. Clofazimine and dapsone+rifampicin can be used in the treatment of a type 2 leprosy reaction. Single-drug regimens are not efficient enough to treat leprosy, multibacillary leprosy, or a type 2 leprosy reaction. AVAILABILITY OF DATA AND MATERIALS: All data generated or analyzed during this study are included in this published article [and its supplementary information files].


Assuntos
Hanseníase Multibacilar , Hanseníase , Humanos , Hansenostáticos/efeitos adversos , Rifampina/efeitos adversos , Clofazimina/efeitos adversos , Metanálise em Rede , Quimioterapia Combinada , Hanseníase/tratamento farmacológico , Dapsona/efeitos adversos , Hanseníase Multibacilar/tratamento farmacológico
4.
Infect Genet Evol ; 103: 105349, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35964914

RESUMO

BACKGROUND: Lyme disease is a zoonotic disease caused by infection with Borrelia burgdorferi (Bb), the involvement of the nervous system in Lyme disease is usually referred to as Lyme neuroborreliosis (LNB). LNB has diverse clinical manifestations, most commonly including meningitis, Bell's palsy, and encephalitis. However, the molecular pathogenesis of neuroborreliosis is still poorly understood. Comprehensive transcriptomic analysis following Bb infection could provide new insights into the pathogenesis of LNB and may identify novel biomarkers or therapeutic targets for LNB diagnosis and treatment. METHODS: In the present study, we pooled transcriptomic dataset of Macaca mulatta (rhesus) from our laboratory and the human astrocyte dataset GSE85143 from the Gene Expression Omnibus database to screen common differentially expressed genes (DEGs) in the Bb infection group and the control group. Functional and enrichment analyses were applied for the DEGs. Protein-Protein Interaction network, and hub genes were identified using the Search Tool for the Retrieval of Interaction Genes database and the CytoHubba plugin. Finally, mRNA expression of hub genes was validated in vitro and ex vivo from Bb infected models and normal controls by quantitative reverse transcription PCR (qRT-PCR). RESULTS: A total of 80 upregulated DEGs and 32 downregulated DEGs were identified. Among them, 11 hub genes were selected. The pathway enrichment analyses on 11 hub genes revealed that the PI3K-Akt signaling pathway was significantly enriched. The mRNA levels of ANGPT1, TLR6, SREBF1, LDLR, TNC, and ITGA2 in U251 cells and/or rhesus brain explants by exposure to Bb were validated by qRT-PCR. CONCLUSION: Our study suggested that TLR6, ANGPT1, LDLR, SREBF1, TNC, and ITGA may be candidate mammal biomarkers for LNB, and the TLR6/PI3K-Akt signaling pathway may play an important role in LNB pathogenesis.


Assuntos
Grupo Borrelia Burgdorferi , Borrelia burgdorferi , Neuroborreliose de Lyme , Animais , Biomarcadores , Borrelia burgdorferi/genética , Grupo Borrelia Burgdorferi/genética , Sistema Nervoso Central , Humanos , Macaca mulatta/genética , Mamíferos , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , RNA Mensageiro , Receptor 6 Toll-Like/genética , Transcriptoma
5.
Microbiol Spectr ; 9(3): e0076121, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34756070

RESUMO

Lyme disease (LD) is a heavy public health burden. The most common manifestations of LD include erythema migrans (EM), Lyme neuroborreliosis (LNB), and Lyme arthritis (LA). The efficacy and safety of antibiotics for treating LD is still controversial. Thus, we performed a network meta-analysis (NMA) to obtain more data and tried to solve this problem. We searched studies in the databases of Embase and PubMed from the date of their establishments until 22 April 2021. Odds ratios (ORs) were used to assess dichotomous outcomes. A total of 31 randomized controlled trials (RCTs) involving 2,748 patients and 11 antibiotics were included. Oral amoxicillin (1.5 g/day), oral azithromycin (0.5 g/day), injectable ceftriaxone, and injectable cefotaxime were effective for treating LD (range of ORs, 1.02 to 1,610.43). Cefuroxime and penicillin were safe for treating LD (range of ORs, 0.027 to 0.98). Amoxicillin was effective for treating EM (range of ORs, 1.18 to 25.66). Based on the results, we thought oral amoxicillin (1.5 g/day), oral azithromycin (0.5 g/day), injectable ceftriaxone, and injectable cefotaxime were effective for treating LD. Cefuroxime and penicillin were safe for treating LD. Amoxicillin was effective for treating EM. We did not observe evidence proving the advantage of doxycycline in efficacy and safety for treating LD, LA, LNB, and EM of children or adults. We did not have sufficient data to prove the significant difference of efficacy for treating LA and LNB in adults and LD in children, the significant difference of safety of oral drugs for treating LD, and the significant difference of safety of drugs for treating EM. IMPORTANCE Some previous studies investigated the efficacy and safety of antibiotics for treating Lyme disease (LD). However, due to technical limitations, several questions regarding the routes of drug administration and the dosages of drug are still unclear, which might be causing problems for clinicians. Hence, we performed network meta-analysis (NMA) to quantitatively analyze the clinical data published during the last 40 years. Here, we demonstrate the evidence regarding the efficacy and safety of antibiotics commonly used for treating LD in adults and children. We found that amoxicillin, azithromycin, ceftriaxone, and cefotaxime were effective for treating LD, but we did not observe significant efficacy and safety of doxycycline for treating LD.


Assuntos
Antibacterianos/efeitos adversos , Antibacterianos/uso terapêutico , Doença de Lyme/tratamento farmacológico , Administração Oral , Adulto , Amoxicilina/efeitos adversos , Amoxicilina/uso terapêutico , Azitromicina/efeitos adversos , Azitromicina/uso terapêutico , Borrelia burgdorferi/efeitos dos fármacos , Grupo Borrelia Burgdorferi/efeitos dos fármacos , Cefotaxima/efeitos adversos , Cefotaxima/uso terapêutico , Ceftriaxona/efeitos adversos , Ceftriaxona/uso terapêutico , Criança , Doxiciclina/efeitos adversos , Doxiciclina/uso terapêutico , Humanos , Injeções/efeitos adversos , Metanálise em Rede , Penicilinas/efeitos adversos , Penicilinas/uso terapêutico
6.
Front Cell Infect Microbiol ; 11: 647662, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34178719

RESUMO

Background: Lyme neuroborreliosis (LNB) is one of the most dangerous manifestations of Lyme disease, but the pathogenesis and inflammatory mechanisms are not fully understood. Methods: Cultured explants from the frontal cortex of rhesus monkey brain (n=3) were treated with live Borrelia burgdorferi (Bb) or phosphate-buffered saline (PBS) for 6, 12, and 24 h. Total protein was collected for sequencing and bioinformatics analysis. In addition, changes in protein expression in the explants over time following Bb treatment were screened. Results: We identified 1237 differentially expressed proteins (DEPs; fold change ≥1.5 or ≤0.67, P-value ≤0.05). One of these, growth-associated protein 43 (GAP-43), was highly expressed at all time points in the explants. The results of the protein-protein interaction network analysis of DEPs suggested that GAP-43 plays a role in the neuroinflammation associated with LNB. In HMC3 cells incubated with live Bb or PBS for 6, 12, and 24 h, real-time PCR and western blot analyses confirmed the increase of GAP-43 mRNA and protein, respectively. Conclusions: Elevated GAP-43 expression is a potential marker for LNB that may be useful for diagnosis or treatment.


Assuntos
Borrelia burgdorferi , Neuroborreliose de Lyme , Animais , Encéfalo , Proteína GAP-43 , Macaca mulatta , Proteômica
7.
Stem Cell Res Ther ; 12(1): 95, 2021 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-33516265

RESUMO

Organoids are derived from stem cells or organ-specific progenitors. They display structures and functions consistent with organs in vivo. Multiple types of organoids, including lung organoids, can be generated. Organoids are applied widely in development, disease modelling, regenerative medicine, and other multiple aspects. Various human pulmonary diseases caused by several factors can be induced and lead to different degrees of lung epithelial injury. Epithelial repair involves the participation of multiple cells and signalling pathways. Lung organoids provide an excellent platform to model injury to and repair of lungs. Here, we review the recent methods of cultivating lung organoids, applications of lung organoids in epithelial repair after injury, and understanding the mechanisms of epithelial repair investigated using lung organoids. By using lung organoids, we can discover the regulatory mechanisms related to the repair of lung epithelia. This strategy could provide new insights for more effective management of lung diseases and the development of new drugs.


Assuntos
Pneumopatias , Lesão Pulmonar , Humanos , Pulmão , Organoides , Medicina Regenerativa
8.
Int Immunopharmacol ; 88: 106914, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32829087

RESUMO

Certain natural products, derived from medicinal plants, exhibit anti-inflammatory properties, but the mechanism of action of many remains unclear. Borrelia burgdorferi spirochetes are responsible for causing Lyme arthritis through activation of the Toll-like receptor (TLR) signaling pathway. In this study, we investigated the mechanisms by which Isoforskolin (ISOF) and Cucurbitacin IIa (CuIIa), compounds derived from Chinese herbs, can exert anti-inflammatory effects by modulating single immunoglobulin interleukin-1 receptor-related receptor (SIGIRR; also known as Toll/interleukin-1 receptor 8, TIR8) and thereby inhibiting B. burgdorferi basic membrane protein A (BmpA)-induced TLR signaling in human macrophages, specifically the THP-1 human monocytic cell line. After THP-1 cells were exposed in vitro to: i) recombinant (r)BmpA, ii) rBmpA and ISOF or iii) rBmpA and CuIIa, Cytotoxicity assay (Cell Counting Kit-8, CCK-8) are used to measure the effects of ISOF and CuIIa on cell viability. Meanwhile, real-time polymerase chain reaction and Western blotting were used to quantify SIGIRR mRNA and protein levels, respectively, at 6, 12, 24 and 48 h time points post-stimulation. In addition, proinflammatory cytokine tumor necrosis factor-α (TNF-α) was determined by ELISA analysis. Our study showed that rBmpA stimulation of THP-1 cells resulted in a drop in SIGIRR levels in THP-1 cells. More importantly, SIGIRR levels increased significantly in rBmpA-stimulated THP-1 cells following ISOF or CuIIa administration, and the results of ELISA analysis suggested that ISOF or CuIIa reduced the secretion of the proinflammatory cytokine TNF-α. In conclusion, These results reveal new possibilities for the treatment of Lyme arthritis.


Assuntos
Anti-Inflamatórios/farmacologia , Proteínas de Bactérias/farmacologia , Borrelia burgdorferi , Colforsina/análogos & derivados , Colforsina/farmacologia , Cucurbitacinas/farmacologia , Macrófagos/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Macrófagos/metabolismo , Receptores de Interleucina-1/genética , Receptores de Interleucina-1/metabolismo , Células THP-1 , Fator de Necrose Tumoral alfa/metabolismo
9.
Vector Borne Zoonotic Dis ; 19(8): 576-581, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30615589

RESUMO

Anaplasma phagocytophilum-the causative agent of human granulocytic anaplasmosis (HGA)-is a tick-borne pathogen transmitted by Ixodid ticks infecting wild and domestic mammals as well as humans. Despite the availability of evidence regarding this emerging infection among vectors, host animals, and individuals in China, there is limited knowledge on the prevalence and distribution of A. phagocytophilum in the Yunnan Province. The aim of this study was to assess the seroprevalence of A. phagocytophilum in healthy adults and patients with acute undifferentiated fever from four regions in the Yunnan Province. The enzyme-linked immunosorbent assay and indirect immunofluorescence assay were used to detect immunoglobulin (Ig) G and IgM antibodies against A. phagocytophilum in sera obtained from 1185 healthy blood donors and 245 patients with acute undifferentiated fever, respectively. Demographic variables were assessed as potential risk factors using the chi-squared test. The rates of seropositivity rates were 7.59% and 4.49% in healthy donors and fever patients, respectively. Analysis of risk factors such as gender, age groups, and place of residence showed statistically significant differences. Infections with A. phagocytophilum occur widely among individuals residing in southwestern China. Our results indicate that there is serological evidence of HGA in this population and presence of acute A. phagocytophilum infections in patients with undifferentiated fever in the Yunnan Province.


Assuntos
Anaplasma phagocytophilum/isolamento & purificação , Anaplasmose/epidemiologia , Ehrlichiose/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antibacterianos/sangue , Criança , China/epidemiologia , Feminino , Febre/diagnóstico , Febre/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Doenças Transmitidas por Carrapatos/epidemiologia
10.
Artigo em Inglês | MEDLINE | ID: mdl-24814004

RESUMO

A novel liquid chromatographic method with tandem mass spectrometric detection (LC-MS/MS) for the determination of LCI699 was developed and validated with dynamic ranges of 0.0500-50.0 ng/mL and 1.00-1,000 ng/mL using 0.0500 mL and 0.100mL, respectively, of human plasma. LCI699 and the internal standard, [M+6]LCI699, were extracted from fortified human plasma via protein precipitation. After transfer or dilution of the supernatant followed by solvent evaporation and/or reconstitution, the extract was injected onto the LC-MS/MS system. Optimal chromatographic separation was achieved on an ACE C18 (50 mm × 4.6mm, 3 µm) column with 30% aqueous methanol (containing 0.5% acetic acid and 0.05% TFA) as the mobile phase run in isocratic at a flow rate of 1.0 mL/min. The total analysis cycle time is approximately 3.5 min per injection. The addition of an ion-pair reagent, TFA (0.05%, v/v), to the mobile phases significantly improved the chromatographic retention and resolution of the analyte on silica based reversed-phase column. Although addition of TFA to the mobile phase suppresses the ESI signals of the analyte due to its ion-pairing characteristics in the gas phase of MS source, this negative impact was effectively alleviated by adding 0.5% acetic acid to the mobile phase. The current method was validated for sensitivity, selectivity, linearity, reproducibility, stability and recovery. For the low curve range (0.0500-50.0 ng/mL), the accuracy and precision for the LLOQs (0.0500 ng/mL) were -13.0 to 2.0% bias and 3.4-19.2% CV, respectively. For other QC samples (0.100, 6.00, 20.0 and 40.0 ng/mL), the precision ranged from 1.2 to 9.0% and from 3.8 to 8.8% CV, respectively, in the intra-day and inter-day evaluations. The accuracy ranged from -11.3 to 8.0% and -7.2 to 1.6% bias, respectively, in the intra-day and inter-day batches. For the high curve range (1.00-1,000 ng/mL), the accuracy and precision for the LLOQs (1.00 ng/mL) were 1.0-15.0% bias and 7.4-9.2% CV, respectively. For the other QC samples (3.00, 20.0, 200 and 750 ng/mL), the precision ranged from 0.8 to 7.0% and from 1.9 to 5.2% CV, respectively, in the intra-day and inter-day evaluations. The accuracy ranged from -2.5 to 4.0% and 0.7-1.0% bias, respectively, in the intra-day and inter-day batches. Additional assessments of incurred sample stability (ISS) and incurred sample reanalysis (ISR) were conducted to demonstrate the ruggedness and robustness of the assay method. The absence of adverse matrix effect and carryover was also demonstrated. The validated method was successfully used to support rapid turnaround human pharmacokinetic studies.


Assuntos
Cromatografia Líquida/métodos , Citocromo P-450 CYP11B2/antagonistas & inibidores , Inibidores das Enzimas do Citocromo P-450/sangue , Imidazóis/sangue , Piridinas/sangue , Espectrometria de Massas em Tandem/métodos , Inibidores das Enzimas do Citocromo P-450/química , Inibidores das Enzimas do Citocromo P-450/farmacocinética , Humanos , Imidazóis/química , Imidazóis/farmacocinética , Limite de Detecção , Modelos Lineares , Piridinas/química , Piridinas/farmacocinética , Reprodutibilidade dos Testes
11.
J Chromatogr B Analyt Technol Biomed Life Sci ; 878(5-6): 583-9, 2010 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-20097141

RESUMO

Analyte loss due to non-specific binding, especially container surface adsorption, is not uncommon in the quantitative analysis of urine samples. In developing a sensitive LC-MS/MS method for the determination of a drug candidate, BAF312, in human urine, a simple procedure was outlined for identification, confirmation and prevention of analyte non-specific binding to a container surface and to recover the 'non-specific loss' of an analyte, if no transfer has occurred to the original urine samples. Non-specific binding or container surface adsorption can be quickly identified by using freshly spiked urine calibration standards and pre-pooled QC samples during a LC-MS/MS feasibility run. The resulting low recovery of an analyte in urine samples can be prevented through the use of additives, such as the non-ionic surfactant Tween-80, CHAPS and others, to the container prior to urine sample collection. If the urine samples have not been transferred from the bulk container, the 'non-specific binding' of an analyte to the container surface can be reversed by the addition of a specified amount of CHAPS, Tween-80 or bovine serum albumin, followed by appropriate mixing. Among the above agents, Tween-80 is the most cost-effective. beta-cyclodextrin may be suitable in stabilizing the analyte of interest in urine via pre-treating the matrix with the agent. However, post-addition of beta-cyclodextrin to untreated urine samples does not recover the 'lost' analyte due to non-specific binding or container surface adsorption. In the case of BAF312, a dynamic range of 0.0200-20.0 ng/ml in human urine was validated with an overall accuracy and precision for QC sample results ranging from -3.2 to 5.1% (bias) and 3.9 to 10.2% (CV), respectively. Pre- and post-addition of 0.5% (v/v) Tween-80 to the container provided excellent overall analyte recovery and minimal MS signal suppression when a liquid-liquid extraction in combination with an isocratic LC separation was employed. The compound was stable in 0.5% Tween-80 treated human urine QC samples for at least 24 h at room temperature, after three freeze/thaw cycles with storage at < or =-60 degrees C and for at least 3 months when stored at < or =-60 degrees C. The current work could serve as a simple example in trouble shooting non-specific binding or container surface adsorption in quantitative analysis of urine samples.


Assuntos
Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos , Adsorção , Cromatografia Líquida/economia , Humanos , Receptores de Lisoesfingolipídeo/metabolismo , Sensibilidade e Especificidade , Espectrometria de Massas em Tandem/economia
12.
Biomed Chromatogr ; 21(8): 841-51, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17441219

RESUMO

A sensitive and simple liquid chromatography-tandem mass spectrometry method for the determination of midazolam and 1'-hydroxymidazolam in human plasma has been developed and validated with a dynamic range of 0.1-250 ng/mL. The analysis was based on semi-automated liquid-liquid extraction followed by evaporation of the extraction solvent, reconstitution and chromatography on a reversed-phase C(18) column. The mobile phase consists of 5 mm ammonium acetate and methanol and runs in gradient at a flow rate of 0.25 mL/min with column temperature of approximately 20 degrees C. The entire column effluent was transferred into the LC-MS/MS interface operated in positive electrospray ionization mode. The chromatographic run time was 4.3 min per injection, with retention times for midazolam, 1'-hydroxymidazolaml and the internal standard, triazolam, of 2.5, 2.3 and 2.1 min, respectively. The intra-day and inter-day precision (RSD %) and accuracy (bias %) of the quality control samples were <15.0% and within +/-13%, respectively. The current method has been applied to a clinical drug-drug interaction study in human.


Assuntos
Cromatografia Líquida/métodos , Midazolam/análogos & derivados , Midazolam/sangue , Espectrometria de Massas em Tandem/métodos , Calibragem , Humanos , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Biomed Chromatogr ; 21(3): 249-56, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17221915

RESUMO

A liquid chromatographic method with tandem mass spectrometric detection (LC-MS/MS) for the determination of N-methyl-4-isoleucine-cyclosporin (NIM811) was developed and validated over the concentration range 1-2500 ng/mL in human whole blood using a 0.05 mL sample volume. NIM811 and the internal standard, d(12)-cyclosporin A (d(12)-CsA), were extracted from blood using MTBE via liquid-liquid extraction. After evaporation of the organic solvent and reconstitution, a 10 microL aliquot of the resulting extract was injected onto the LC-MS/MS system. Chromatographic separation of NIM811 and internal standard was performed using a Waters Symmetry RP-8 (50 x 4.6 mm, 3 microm particle size) column. The mobile phase consists of 10 mm ammonium acetate in water (A) and acetonitrile (B), with 45% B from 0 to 0.2 min, 45 to 85% B from 0.2 to 0.8 min and 85% B from 0.8 to 2.2 min. The total run time was 3.5 min with a flow rate of 0.8 mL/min. The method was validated for sensitivity, linearity, reproducibility, stability, dilution integrity and recovery. The precision and accuracy of quality control samples at low (2.00 ng/mL), medium (20.0 and 400 ng/mL) and high (2000 ng/mL) concentrations were in the range 1.1-4.3% relative standard deviation (RSD) and -2.5-10.0% (bias), respectively, from three validation runs. The method has been used to measure the exposure of NIM811 in human subjects.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ciclosporina/sangue , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Área Sob a Curva , Ciclosporina/administração & dosagem , Estabilidade de Medicamentos , Humanos , Indicadores e Reagentes , Modelos Lineares , Estrutura Molecular , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
J Chromatogr B Analyt Technol Biomed Life Sci ; 846(1-2): 57-68, 2007 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-16962398

RESUMO

For the first time, a liquid chromatographic method with tandem mass spectrometric detection (LC-MS/MS) for the simultaneous determination of ribavirin and rabavirin base was developed and validated over the concentration range of 10-5,000 ng/ml, respectively, using a 0.025 ml monkey plasma sample. Ribavirin, ribavirin base, and the internal standards were extracted from monkey plasma via protein precipitation. After evaporation of the supernatant, the extract was reconstituted with 5% methanol (containing 0.1% formic acid) and injected onto the LC-MS/MS system. Optimum chromatographic separation was achieved on a Waters Atlantis dc18 (150 mm x 2.1mm, 5 microm) column with mobile phase run in gradient with 100% water containing 0.5% formic acid (A) and 90% acetonitrile (containing 0.5% formic acid (B). The flow rate was 0.4-0.6 ml/min with total cycle time of approximately 7.0 min. Post-column addition of acetonitrile (containing 0.1% formic acid) at 0.3 ml/min was used to increase the ionization efficiency in the MS source. The method was validated for sensitivity, linearity, reproducibility, stability and recovery. Lack of adverse matrix effect and carry-over was also demonstrated. The intra-day and inter-day precision and accuracy of the quality control (QC) samples were <9.0% relative standard deviation (R.S.D.) and 10.8% bias for ribavirin, and 10.3% R.S.D. and 11.3% bias for ribavirin base. The current specific, accurate and precise assay is useful in support of the toxicokinetic and pharmacokinetic studies of these compounds.


Assuntos
Antivirais/sangue , Cromatografia Líquida de Alta Pressão/métodos , Ribavirina/sangue , Espectrometria de Massas em Tandem/métodos , Animais , Haplorrinos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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