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Dynamic functional network connectivity (dFNC) is an expansion of static FNC (sFNC) that reflects connectivity variations among brain networks. This study aimed to investigate changes in sFNC and dFNC strength and temporal properties in individuals with subthreshold depression (StD). Forty-two individuals with subthreshold depression and 38 healthy controls (HCs) were included in this study. Group independent component analysis (GICA) was used to determine target resting-state networks, namely, executive control network (ECN), default mode network (DMN), sensorimotor network (SMN) and dorsal attentional network (DAN). Sliding window and k-means clustering analyses were used to identify dFNC patterns and temporal properties in each subject. We compared sFNC and dFNC differences between the StD and HCs groups. Relationships between changes in FNC strength, temporal properties, and neurophysiological score were evaluated by Spearman's correlation analysis. The sFNC analysis revealed decreased FNC strength in StD individuals, including the DMN-CEN, DMN-SMN, SMN-CEN, and SMN-DAN. In the dFNC analysis, 4 reoccurring FNC patterns were identified. Compared to HCs, individuals with StD had increased mean dwell time and fraction time in a weakly connected state (state 4), which is associated with self-focused thinking status. In addition, the StD group demonstrated decreased dFNC strength between the DMN-DAN in state 2. sFNC strength (DMN-ECN) and temporal properties were correlated with HAMD-17 score in StD individuals (all p < 0.01). Our study provides new evidence on aberrant time-varying brain activity and large-scale network interaction disruptions in StD individuals, which may provide novel insight to better understand the underlying neuropathological mechanisms.
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A novel magnetic metal-organic framework composite was prepared by a self-assembly approach. The material properties were characterized by Fourier-transform infrared spectroscopy, vibrating sample magnetometry, thermogravimetry and differential thermogravimetric analysis, and X-photoelectron spectroscopy. Then, the as-prepared material was used as an adsorbent and indicated great enrichment ability toward glyphosate, glufosinate, bialaphos, and their main metabolites aminomethylphosphonic acid and 3-methylphosphinicopropionic acid. Based on this, an efficient magnetic solid-phase extraction method combined with ultra high performance liquid chromatography with high-resolution mass spectrometry for the pretreatment and determination of five target compounds in environmental waters was established. Parameters that could impact on the adsorption performance had been studied in detail. The proposed method was successfully applied for the simultaneous determination of glyphosate, glufosinate, bialaphos, and their main metabolites aminomethylphosphonic acid and 3-methylphosphinicopropionic acid in environmental water with recoveries in range of 86.2-104.6% with relative standard deviations less than 10%. Desired linearity was achieved varying from 1 to 100 µg/L for five target analytes, respectively. The limits of detection were between 0.01 and 0.03 µg/L.
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Chondrocyte apoptosis is the most important element of development and progression of osteoarthritis (OA). Nitric oxide (NO) was used as the agent to induce chondrocyte apoptosis. Carboxymethylated chitosan (CMCS) has anti-apoptosis effect on many cell types in vitro. This study was designed to investigate the protective effect of CMCS on NO-induced chondrocyte apoptosis and the probable molecular mechanisms. The newborn Sprague-Dawley (SD) rats were used in this study for isolation of chondrocytes. The cell viability was determined by cell counting kit (CCK-8), cell apoptosis was detected by Annexin-V/PI double staining assay kit. The levels of phosphorylated-PI3K (p-PI3K), phosphorylated-Akt (p-Akt), Bcl-2 and Bax were determined by Western blot analysis. The caspase-3 activity was determined by a quantitative colorimetric assay. Results showed that pretreatment with CMCS could inhibit the apoptosis induced by NO. CMCS could decrease the activity of NO and decrease the expression of Bcl-2, p-PI3K and p-Akt, increase the expression of Bax, cytochrome c and caspase-3. CMCS also could reverse the effect of NO that prompted matrix metalloproteinase-13 (MMP-13) and inhibited tissue inhibitor of metalloproteinase-1 (TIMP-1) activity. All the present results indicated that CMCS can protect NO induced chondrocytes apoptosis by activate PI3K/Akt signaling pathway.
Assuntos
Apoptose , Quitosana/análogos & derivados , Condrócitos/metabolismo , Óxido Nítrico/química , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Cartilagem Articular/metabolismo , Caspase 3/metabolismo , Sobrevivência Celular , Quitosana/química , Condrócitos/citologia , Citocromos c/metabolismo , Metaloproteinase 13 da Matriz/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Proteína X Associada a bcl-2/metabolismoRESUMO
BACKGROUND: Exposure to ubiquitous polycyclic aromatic hydrocarbons (PAHs) has been associated with decreased heart rate variability (HRV). Evidence accumulates that microRNAs (miRNAs) might be the intermediate factors between environmental exposures and their adverse health effects. Single nucleotide polymorphisms (SNPs) in miRNA genes may affect phenotypes and disease morbidity. OBJECTIVE: We sought to investigate the influences of four well-studied SNPs in miRNA genes (rs2910164, rs11614913, rs2292832, and rs3746444) on HRV, and their modifying effects on the associations between PAH exposure and HRV. METHODS: We measured the concentrations of ten urinary monohydroxy PAHs (OH-PAHs), seven HRV parameters, and genotypes of these four SNPs in 1222 coke oven workers. RESULTS: There were significant differences among different rs2910164 genotype carriers in terms of all seven HRV indices: workers with rs2910164 CC genotype had significant lower HRV than those with GG or GC genotype (P<0.05). The number of rs2910164 C allele was negatively associated with HRV indices in the high PAH exposure group (ß<0, P<0.05), and the association between rs2910164 and high-frequency (HF) power was significantly stronger in high exposure group (Pinteraction=0.042). Interestingly, the negative associations between the sum of 10 OH-PAHs and HRV (ß<0, P<0.05) were significantly or marginally significantly stronger in workers with rs2910164 CC genotype (Pinteraction≤0.050). CONCLUSIONS: Coke oven workers with miR-146a rs2910164 CC genotype may be more susceptible to decreased HRV. The modifying effect of rs2910164 on the PAHs-HRV associations suggested miR-146a may mediate the effects of PAH exposure on HRV.
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Poluentes Ocupacionais do Ar/urina , Frequência Cardíaca/genética , MicroRNAs/genética , Exposição Ocupacional/análise , Hidrocarbonetos Policíclicos Aromáticos/urina , Adulto , Monitoramento Ambiental , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Almost half of prescription medications are metabolized by cytochrome P450 3A4 and 3A5. CYP3A4 and 3A5 have significant substrate overlap, and there is currently no way to selectively monitor the activity of these two enzymes, which has led to the erroneous habit of attributing the cumulative activity to CYP3A4. While CYP3A4 expression is ubiquitous, CYP3A5 expression is polymorphic, with large individual differences in CYP3A5 expression level. The CYP3A5 genotype has been shown to alter the pharmacokinetics of drugs in clinical trials. We report the first tool compound capable of determining CYP3A5 activity in biologic samples containing both enzymes. Oxidation of T-5 by CYP3A5 yields an N-oxide metabolite that is over 100-fold selective over CYP3A4. Formation of T-5 N-oxide highly correlates with the CYP3A5 genotype and CYP3A5 expression levels in human liver microsomes and human hepatocytes.
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Óxidos N-Cíclicos/metabolismo , Citocromo P-450 CYP3A/metabolismo , Isoquinolinas/farmacologia , Piridinas/farmacologia , Biotransformação , Catálise , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Citocromo P-450 CYP3A/genética , Inibidores do Citocromo P-450 CYP3A , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Feminino , Genótipo , Hepatócitos/efeitos dos fármacos , Hepatócitos/enzimologia , Humanos , Isoquinolinas/metabolismo , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Oxirredução , Piridinas/metabolismo , Proteínas Recombinantes , Especificidade por Substrato , Espectrometria de Massas em TandemRESUMO
This study aimed to investigate the suppressive effect of nicotine on fetal adrenal steroidogenesis and to explore the potential role of epigenetic modification of steroidogenic factor-1 (SF-1) transcriptional activity in this process. Nicotine was intragastrically administered to pregnant rats and NCI-H295A cells were treated with nicotine or trichostatin A (TSA). The pathomorphology of fetal adrenals, steroid hormone levels, the expression of SF-1 and its target genes, and histone deacetylase (HDAC) mRNA were analyzed. Histone modification and DNA methylation of the SF-1 promoter region were assessed using chromatin immunoprecipitation (ChIP) and bisulfite sequencing PCR. The interaction between SF1 and its target genes was observed. Prenatal nicotinic exposure decreased fetal body weight, increased the IUGR rate and caused detrimental changes in fetal adrenal. In addition, the levels of corticosterone, the expression of SF-1 and its target genes were decreased while HDAC2 expression was enhanced. Nicotine treatment decreased histone H3K9 and H3K14 acetylation levels while there was no effect on the methylation frequency on the SF-1 promoter region. Furthermore, in nicotine-treated NCI-H295A cells, lower levels of steroidogenic synthesis, lower expression of SF-1 and its target genes were observed while the expression of HDACs was enhanced. The interaction between SF1 and StAR decreased with nicotine treatment. Nicotine treatment decreased histone H3K9 and H3K14 acetylation levels, and addition of TSA reversed the inhibition of nicotine-mediated SF-1 and its partial target genes. Thus, nicotine-mediated reduction of SF-1 expression resulted in an inhibitory effect on the expression of its target genes and steroid production via histone deacetylation.
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Glândulas Suprarrenais/efeitos dos fármacos , Glândulas Suprarrenais/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Nicotina/toxicidade , Fator Esteroidogênico 1/metabolismo , Animais , Linhagem Celular , Epigenômica , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Retardo do Crescimento Fetal/induzido quimicamente , Exposição Materna , Gravidez , Ratos , Fator Esteroidogênico 1/genéticaRESUMO
Purpose: Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) are primary liver cancers with different therapeutic methods and prognoses. This study aims to investigate the ultrasonography and enhanced computed tomography (CT) features of these cancers and improve the early diagnosis rate. Methods: We retrospectively analyzed the clinical and imaging data of 319 patients diagnosed with HCC and 124 patients diagnosed with ICC, confirmed by pathology. Results: A total of 443 patients were eligible in this study. From the perspective of clinical data, between HCC and ICC patients existed significant differences in age, gender, hepatic background, serum tumor markers of AFP and CA19.9, chronic hepatitis B/C and lymph node infiltration (p<0.05), but not in tumor size, microvascular invasion, serum tumor markers of CEA and CA125 (P>0.05). With respect to ultrasonography features, HCC patients had a higher proportion than ICC patients in splenomegaly (p=0.001), while ICC patients had a higher proportion than HCC patients in absence/not rich vascularity and intrahepatic bile duct dilatation (p<0.05). With respect to CT features, HCC patients were significantly different from ICC patients in the three-phase enhanced CT value mean, enhanced intensity and homogeneity of nodules (P<0.05). A multivariate logistic regression analysis was performed to further clarify the correlation of these indices. However, only age≤60 years (OR=1.861, P=0.045), male (OR=3.850, P<0.001), AFP>7ng/ml (OR=0.119, P<0.001), lymph node infiltration (OR=5.968, P<0.001), intrahepatic bile duct dilatation (OR=2.414, P=0.04), splenomegaly (OR=0.081, P<0.001), rim APHE (OR=3.109, P=0.002), and iso- or hyper enhancement (OR=0.188, P<0.001) were independent risk factors. Conclusions: While there are overlapping ultrasonography and CT features between HCC and ICC, the integration of tumor markers and specific imaging characteristics can be beneficial in distinguishing between the two.
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BACKGROUND: Most chemotherapeutic agents are characterized by poor water solubility and non-specific distribution. Polymer-based conjugates are promising strategies for overcoming these limitations. OBJECTIVE: This study aims to fabricate a polysaccharide, dextran-based, dual-drug conjugate by covalently grafting docetaxel (DTX) and docosahexaenoic acid (DHA) onto the bifunctionalized dextran through a long linker, and to investigate the antitumor efficacy of this conjugate against breast cancer. METHODS: DTX was firstly coupled with DHA and covalently bounded with the bifunctionalized dextran (100 kDa) through a long linker to produce a conjugate dextran-DHA-DTX (termed C-DDD). Cytotoxicity and cellular uptake of this conjugate were measured in vitro. Drug biodistribution and pharmacokinetics were investigated through liquid chromatography/mass spectrometry analysis. The inhibitory effects on tumor growth were evaluated in MCF-7- and 4T1-tumor-bearing mice. RESULTS: The loading capacity of the C-DDD for DTX was 15.90 (weight/weight). The C-DDD possessed good water solubility and was able to self-assemble into nanoparticles measuring 76.8 ± 5.5 nm. The maximum plasma concentration and area under the curve (0-∞) for the released DTX and total DTX from the C-DDD were significantly enhanced compared with the conventional DTX formulation. The C-DDD selectively accumulated in the tumor, with limited distribution was observed in normal tissues. The C-DDD exhibited greater antitumor activity than the conventional DTX in the triplenegative breast cancer model. Furthermore, the C-DDD nearly eliminated all MCF-7 tumors in nude mice without leading to systemic adverse effects. CONCLUSION: This dual-drug C-DDD has the potential to become a candidate for clinical application through the optimization of the linker.
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Antineoplásicos , Nanopartículas , Neoplasias de Mama Triplo Negativas , Humanos , Camundongos , Animais , Docetaxel/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos/química , Dextranos , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Distribuição Tecidual , Camundongos Nus , Taxoides/farmacologia , Taxoides/uso terapêutico , Taxoides/química , Portadores de Fármacos/química , Linhagem Celular Tumoral , Nanopartículas/química , Água , Camundongos Endogâmicos BALB CRESUMO
The present work is to investigate the correlation between physical properties and deformation behaviors of tablet excipients, and rank them according to their plastic performances during compaction. The excipients selected were compacted using Korsch XP1 after measuring their physical properties where the compression parameters for evaluating deformation behaviors were Heckle equation, compression work and elastic stretch in die. The correlations between compaction descriptors and physical parameters were analyzed by canonical correlation analysis, and factor analysis was simultaneously employed to synthetically assess deformation behaviors for all our samples. The canonical variables show that true density (Pa) correlated negatively with plastic coefficient (PL) and positively with yield pressure (YP); compression degree (Cp) correlated negatively with fast elastic stretch (FES) as well as YP and positively with PL. When factor scores were used in combination with original data, the plasticity of our samples was sorted and ranked as high (-0.56 < F' < 0.21), intermediate (-0.16 < F' < 0.36), or low (0.38 < F' < 0.84), which are in accord with plasticity rankings previously reported in literature. This study indicates factor analysis can be an approach to evaluate deformation behaviors of pharmaceutical powders.
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Química Farmacêutica/métodos , Força Compressiva , Elasticidade , Excipientes/química , Preparações Farmacêuticas/química , Análise Fatorial , Tamanho da Partícula , Pós/química , Pressão , ComprimidosRESUMO
As production processes have evolved, airborne concentrations of benzene, toluene and xylene in many workplaces are already well below the occupational exposure limits. However, studies have shown that low levels of exposure to benzene, toluene and xylene can still cause health effects in people exposed occupationally. However, there is no literature on health risk assessment of internal exposure. In view of this, an analytical method based on quaternary amine-functionalized core-shell-shell magnetic polymers (QA-CSS-MPs) was developed for the determination of seven metabolites in urine by MSPE-UPLC-DAD-HRMS. Furthermore, an improved QuEChERS method for the extraction of seven metabolites from human urine samples was introduced for the first time and satisfactory extraction rates were achieved. In addition, QA-CSS-MPs microspheres with core-shell-shell structure were designed and synthesized, and the morphology, composition and magnetic properties of the materials were fully characterized to verify the rationality of the synthetic route. Subsequently, QA-CSS-MPs microspheres were used as magnetic solid-phase extraction (MSPE) adsorbents for the purification of urine extracts, and UPLC-DAD-HRMS was used for the detection of seven metabolites. As a result, this method allows the accurate determination of seven metabolites in urine samples over an ultra-wide concentration range (0.001-100 mg/L). Under optimal experimental conditions, i.e., 2% hydrochloric acid in urine for the hydrolysis and 20 mg of QA-CSS-MPs for 5 min purification, the spiked recoveries of the seven target metabolites ranged from 81.5% to 117.7% with RSDs of 1.0%-9.4%. The limits of detection (LODs, S/N≥3) for the established method were in the range of 0.2-0.3 µg/L. The developed method was applied to 254 human urine samples for the determination of seven metabolites. The results showed that the concentration distributions of three xylene metabolites in urine, 2-MHA, 3-MHA, 4-MHA and total MHA, showed statistically significant differences for occupational exposure (p<0.001). In addition, the results of the internal exposure assessment showed that there is a high potential health risk associated with occupational exposure processes.
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Benzeno , Tolueno , Humanos , Xilenos , Aminas , Polímeros , Fenômenos MagnéticosRESUMO
Introduction: To investigate the major existing occupational hazards and to assess the occupational health risks for ferrous metal foundries (FMFs) in Ningbo, China. Methods: Unified questionnaires were formulated to investigate the information on the basic situations, occupational hazards, and occupational health management for 193 FMFs in Ningbo. Furthermore, we used the semi-quantitative risk assessment model, which was developed by the International Council on Mining and Metals (ICMM), to assess occupational health risks for 59 of 193 the FMFs. Results: The casting process of FMFs in Ningbo was mainly divided into sand casting and investment casting, and silica-dust and noise were the major occupational hazards in both sand casting and investment casting foundries. Silica-dust mainly occurred in industries with such work as sand handling, modeling, falling sand, and sand cleaning, with the median of the permissible concentration-time weighted average (PC-TWA) was 0.80, 1.15, 3.52, 0.83 mg/m3, respectively. The noise mainly existed in industries with such work as sand handling, core making, falling sand, sand cleaning, cutting and grinding, and smelting with median of PC-TWA was 81.72 dB(A), 82.93 dB(A), 90.75 dB(A), 80.18 dB(A), 90.05 dB(A), 82.70 dB(A), respectively. In addition, the results of the ICMM assessment model indicated that 100 and 98.7% of the jobs exposed to silica-dust and noise in 59 FMFs have an "intolerable risk" level of risks of causing pneumoconiosis and noise deaf, respectively. Discussion: The hazard risk of silica-dust and noise is serious for FMFs in Ningbo. It is necessary to supervise enterprises to improve operating environmental conditions, accelerate the reduction of silica-dust and noise exposure risks, and promote the healthy and sustainable development of the foundry industry.
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Exposição Ocupacional , Exposição Ocupacional/análise , Areia , Poeira/análise , Medição de Risco , Dióxido de Silício/análiseRESUMO
MicroRNAs (miRNAs) refer to short in-length, noncoding RNAs that regulate numerous cellular functions by targeting mRNA, and numerous types of research have shown that miRNA is vitalin Alzheimer's disease. For identifying differentially expressed miRNAs in the peripheral blood mononuclear cell (PBMC) of early-onset familial Alzheimer's disease (EOFAD), we conducted this study which might give a reference for potential therapeutic targets or biomarkers for this disease. On the basis of high-throughput sequencing, we screened the miRNAs expression profiles in PBMC regarding both EOFAD patients and healthy controls, and the biological information was analyzed. Compared with the PBMC of healthy controls, 142 miRNAs were differentially expressed in EOFAD patients ( P < 0.05), including 48 significantly differentially expressed miRNAs, 37 of which were significantly upregulated, including miR-3614-5p, miR-193A-5p, miR-2115-5p, miR-143-3p, etc. and 11 were significantly downregulated, including miR-484, miR-708-5p, miR-205-5p, miR-31-5p, etc. According to biological information analysis, 768 miRNA target genes were differentially expressed, which may be involved in multiple gene functions and cell cycle, cell senescence, and several signaling pathways, including FoxO, MAPK, Ras, mTOR, neurotrophin, etc. There are differential expressions of miRNAs in PBMC of EOFAD patients and controls, revealing their importance in Alzheimer's disease as indicated by co-expression network analysis; this may support basic information for new biomarkers or treatment exploring.
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Doença de Alzheimer , MicroRNAs , Humanos , MicroRNAs/metabolismo , Leucócitos Mononucleares/metabolismo , Doença de Alzheimer/genética , Perfilação da Expressão Gênica , BiomarcadoresRESUMO
Most chemotherapeutic agents are nonspecific distribution and cause systemic toxicities. Polysaccharide-based conjugates are promising strategies to overcome these drawbacks. To this end, two synergistic drugs docetaxel (DTX) and docosahexaenoic acid (DHA) were independently covalently bonded through individual linkers to dextran (100 kDa) to produce a novel dual-drug conjugate dextran-DHA-DTX. The single-drug conjugates dextran-DHA and dextran-DTX were also prepared for comparison. Fluorescent dye Cy7.5-based conjugates dextran-Cy7.5 and dextran-DHA-Cy7.5 were synthesized for cellular uptake study. The dual-drug conjugate dextran-DHA-DTX self-assembled into nanoparticles with the diameter of 102.3 ± 8.3 nm and demonstrated enhanced water solubility and improved pharmacokinetic profiles. Cellular uptake results showed that the dual-drug conjugate entered cells more than the parent DTX by determining the intracellular DTX contents via HPLC/MS analysis and by determining the fluorescent intensity of dextran-Cy7.5 and dextran-DHA-Cy7.5. Importantly, the dual-drug conjugate dextran-DHA-DTX significantly accumulated in tumor tissues and dramatically reduced the DTX concentrations in normal tissues. The dual-drug conjugate completely eradicated all the MCF-7 xenograft tumors without obvious side effects and showed more superior antitumor activity than parent DTX and single-drug conjugate dextran-DTX and dextran-DHA. Both in vitro and in vivo studies showed that DHA enhanced the antitumor activity of dextran-DTX. The polysaccharide dextran-based dual-drug conjugates may represent an effective way to improve the chemotherapeutic agents.
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Dextranos , Ácidos Docosa-Hexaenoicos , Humanos , Docetaxel , Preparações Farmacêuticas , Polissacarídeos , Corantes FluorescentesRESUMO
Cabazitaxel (CTX) is a medication used for treating metastatic prostate cancer. However, its effectiveness is majorly limited by its poor water solubility and lack of tumor targeting. In this study, three unsaturated fatty acids, GLA, ALA and DHA, were separately connected with CTX and then covalently attached to bifunctionalized dextran through a linker to produce three dual drug conjugates named dextran-GLA-CTX, dextran-ALA-CTX and dextran-DHA-CTX. The three conjugates displayed enhanced solubility of CTX in water and improved antitumor effects compared to the conventional CTX formulation. The results also confirmed that dextran-GLA-CTX exhibited the strongest antitumor activity, while dextran-DHA-CTX displayed less efficacy, as evaluated through xenografted nude mice bearing PC-3 and DU145 prostate cancer cells. Additionally, dextran-GLA-CTX showed greater inhibition of tumor growth than dextran-CTX. Moreover, the dextran-GLA-CTX conjugate was found to prolong the half-life of CTX in plasma and selectively accumulate in tumors. This study revealed that unsaturated fatty acids can enhance the antitumor activity of dextran-based conjugates grafted with CTX.
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Dextranos , Neoplasias da Próstata , Humanos , Masculino , Camundongos , Animais , Camundongos Nus , Ácidos Graxos Insaturados/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Água , Ácidos Docosa-Hexaenoicos , Ácidos GraxosRESUMO
Current molecular tools lack the ability to differentiate the activity of CYP3A4 and CYP3A5 in biological samples such as human liver microsomes. Kinetic experiments and the CYP3A4 crystal structure indicate that the active sites of both enzymes are large and flexible, and have more than one binding subsite within the active site. 1-(4-Imidazopyridinyl-7phenyl)-3-(4'-cyanobiphenyl) urea (SR-9186) was optimized through several rounds of structural refinement from an initial screening hit to obtain greater than 1000-fold selectivity for the inhibition of CYP3A4 versus CYP3A5. Characterization data demonstrate selectivity using midazolam and testosterone hydroxylation assays with recombinant cytochrome P450, pooled human liver microsomes, and individually genotyped microsomes. Clear differences are seen between individuals with CYP3A5*1 and *3 genotypes. The antifungal drug ketoconazole is the most commonly used CYP3A inhibitor for in vitro and in vivo studies. A direct comparison of SR-9186 and ketoconazole under typical assay conditions used in reaction phenotyping studies demonstrated that SR-9186 had selectivity over CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A5 greater than or equal to that of ketoconazole. In addition, the long half-life (106 min) of SR-9186 in incubations containing 1 mg/ml human liver microsomes provided sustained CYP3A4 inhibition.
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Inibidores do Citocromo P-450 CYP3A , Inibidores Enzimáticos/farmacologia , Imidazóis/farmacologia , Fígado/efeitos dos fármacos , Compostos de Fenilureia/farmacologia , Citocromo P-450 CYP3A/metabolismo , Relação Dose-Resposta a Droga , Descoberta de Drogas , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Meia-Vida , Humanos , Hidroxilação , Imidazóis/síntese química , Imidazóis/metabolismo , Cetoconazol/farmacologia , Fígado/enzimologia , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Midazolam/metabolismo , Estrutura Molecular , Fenótipo , Compostos de Fenilureia/síntese química , Compostos de Fenilureia/metabolismo , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade , Especificidade por Substrato , Testosterona/metabolismoRESUMO
Clozapine was the first of the atypical antipsychotics to be developed, but its use has been restricted because of toxicity issues, particularly the risk of potentially life-threatening drug-induced neutropenia and agranulocytosis, which occurs in about 1% of patients. Bioactivation of clozapine by peroxidases forms a reactive nitrenium ion, which covalently adducts to protein and leads to neutrophil toxicity. The current generation of clozapine-inspired atypical antipsychotics has reduced toxicity through improved potency/decreased dose or through structural modification to prevent peroxidase-catalyzed nitrenium ion formation. Through the substitution of sulfur for the bridging nitrogen found in clozapine, quetiapine does not directly form a nitrenium ion when incubated with myeloperoxidase/H(2)O(2). We present evidence that cytochrome P450 2D6 catalyzes the formation of 7-hydroxyquetiapine, which can be oxidized by human myeloperoxidase to form a reactive quinone-imine and a reactive radical, which may account for the continued, although reduced, neutrophil toxicity. In the presence of myeloperoxidase/H(2)O(2) and glutathione, covalent 7-hydroxyquetiapine-glutathione adducts were formed. Bioactivation of quetiapine was verified in vivo in rat where three 7-hydroxyquetiapine-mercaptate adducts and a 7-hydroxyquetiapine-glutathione adduct were detected from bile after oral dosing. The decreased incidence of agranulocytosis with quetiapine over clozapine is postulated to be due to the lower exposure of the toxic precursor, 7-hydroxyquetiapine versus clozapine, respectively.
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Agranulocitose/metabolismo , Antipsicóticos/metabolismo , Dibenzotiazepinas/metabolismo , Neutropenia/metabolismo , Agranulocitose/induzido quimicamente , Animais , Antipsicóticos/efeitos adversos , Clozapina/análogos & derivados , Cianetos/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Dibenzotiazepinas/efeitos adversos , Feminino , Glutationa/metabolismo , Peroxidase do Rábano Silvestre/metabolismo , Humanos , Masculino , Neutropenia/induzido quimicamente , Peroxidase/metabolismo , Fumarato de Quetiapina , Ratos , Ratos Sprague-DawleyRESUMO
Cytochrome P450s are the major family of enzymes responsible for the oxidative metabolism of pharmaceuticals and xenobiotics. CYP3A4 and CYP3A5 have been shown to have overlapping substrate and inhibitor profiles and their inhibition has been demonstrated to be involved in numerous pharmacokinetic drug-drug interactions. Here we report the first highly selective CYP3A4 inhibitor optimized from an initial lead with ≈30-fold selectivity over CYP3A5 to yield a series of compounds with greater than 1000-fold selectivity.
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Inibidores do Citocromo P-450 CYP3A , Imidazóis/química , Imidazóis/farmacologia , Piridinas/química , Piridinas/farmacologia , Citocromo P-450 CYP3A , Ativação Enzimática/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Estrutura MolecularRESUMO
The main methods of characterizing the flowability of pharmaceutical powders include repose angle method, HR method, Carr's index method, Jenike flow function method, fractal dimension method, and mass flow rate method, etc. Regarding powders with different flowabilities as the research subject, comprehensive features of pharmaceutical materials were investigated and characterized. The multivariate analysis method was employed to evaluate and analyze flowability values of the tested pharmaceutical materials. Comparing with the method of the mass flow rate, it was feasible to use multivariate analysis method to evaluate the flowability of powders. Simultaneously, the flowability of pharmaceutical materials could be ranked and definitely quantified, and critical values be determined according to the actual production, which has promoted the previous methods dependent only on the single parameter, i.e. repose angle and compression degree methods. A relatively objective standard method of evaluating flowability of powders is formed.
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Pós/química , Tecnologia Farmacêutica/métodos , Análise Multivariada , Tamanho da Partícula , Análise de Componente PrincipalRESUMO
OBJECTIVE: To characterize the flowability of traditional Chinese medicine (TCM) powders by using appropriate methods. METHOD: With highly flowable direct compression excipients and Chinese traditional medicine powder as raw materials, the flowability of material powders is determined by the Carr method and the Jenike method. RESULT: The Carr method and the Jenike method for the determination of the flowability of Chinese herb extract powder and direct-pressing excipients have no obvious difference. But the flowability of Chinese herb extract powder is not as good as direct compression excipients. CONCLUSION: From the characterization results of both methods, we can find that the Carr method better reflects the actual flowability of TCM extracts, while the Jenike method can be used for guiding the design of the hopper device.
Assuntos
Medicina Tradicional Chinesa , Tamanho da Partícula , Pós/químicaRESUMO
OBJECTIVE: To investigate the effects of occupational exposure to formaldehyde on the micronuclei frequencies in peripheral blood lymphocytes of workers. METHODS: Two hundred thirty six plywood workers were divided into 3 exposure groups (low, middle and high) according to internal exposure biomarker (formaldehyde human serum albumin conjugate, FA-HSA), which was detected by ELISA. The concentrations of formaldehyde (FA) in air of two workshops were measure using the high performance liquid chromatography. Cytokinesis-block micronucleus (CBMN) test was used to detect the micronuclei frequencies of peripheral blood lymphocyte in 236 workers. RESULTS: The average concentrations of FA in the low and high exposure workshops were 0.58 +/- 0.20 and 1.48 +/- 0.61 mg/m3, respectively, there was significant difference (P < 0.01). The average concentrations of serum FA-HAS of workers in two workshops were 69.22 +/- 15.37 and 136.29 +/- 89.49 pg/ml, respectively, there was significant difference (P < 0.01). The results of CBMN test showed that the micronucleus frequencies in low, middle and high exposure groups were 1.94 +/- 1.72, 2.10 +/- 1.92 and 2.10 +/- 1.70 per thousand, respectively, there were no significant differences between groups. However, the micronucleus frequencies in accumulative low, middle and high exposure groups were 1.36 +/- 1.36, 2.31 +/- 1.81 and 2.49 +/- 1.92 per thousand, respectively, there were significant differences between different accumulative exposure groups (P < 0.01). The results of correlation analysis indicated that there was a positive correlation between accumulative exposure levels and micronucleus frequencies (r(s) = 0.321, P < 0.01). The accumulative exposure doses may be a risk factor for high micronucleus frequencies in workers exposed to FA (P(trend) = 0.002). CONCLUSION: FA-HSA levels can serve as an internal exposure biomarker for assessing the exposure level of workers exposed to FA. Accumulative formaldehyde exposure resulted in an increase of micronuclei frequencies of peripheral blood lymphocyte in plywood workers.