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BACKGROUND: The prognostic and therapeutic implications of endothelial cells (ECs) heterogeneity in prostate cancer (PCa) are poorly understood. METHODS: We investigated associations of EC heterogeneity with PCa recurrence and castration resistance in 8 bulk transcriptomic and 4 single-cell RNA-seq cohorts. A recurrence-associated EC (RAEC) signature was constructed by comparing 11 machine learning algorithms through nested cross-validation. Functional relevances of RAEC-specific genes were also tested. RESULTS: A subset of ECs was significantly associated with recurrence in primary PCa and named RAECs. RAECs were characteristic of tip and immature cells and were enriched in migration, angiogenesis, and collagen-related pathways. We then developed an 18-gene RAEC signature (RAECsig) representative of RAECs. Higher RAECsig scores independently predicted tumor recurrence and performed better or comparably compared to clinicopathological factors and commercial gene signatures in multiple PCa cohorts. Of the 18 RAECsig genes, FSCN1 was upregulated in ECs from PCa with higher Gleason scores; and the silencing of FSCN1, TMEME255B, or GABRD in ECs either attenuated tube formation or inhibited PCa cell proliferation. Finally, higher RAECsig scores predicted castration resistance in both primary and castration-resistant PCa. CONCLUSION: This study establishes an endothelial signature that links a subset of ECs to prostate cancer recurrence and castration resistance.
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Células Endoteliais , Recidiva Local de Neoplasia , Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Progressão da Doença , Prognóstico , Transcriptoma , Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologiaRESUMO
Recent studies have identified DNA replication stress as an important feature of advanced prostate cancer (PCa). The identification of biomarkers for DNA replication stress could therefore facilitate risk stratification and help inform treatment options for PCa. Here, we designed a robust machine learning-based framework to comprehensively explore the impact of DNA replication stress on prognosis and treatment in 5 PCa bulk transcriptomic cohorts with a total of 905 patients. Bootstrap resampling-based univariate Cox regression and Boruta algorithm were applied to select a subset of DNA replication stress genes that were more clinically relevant. Next, we benchmarked 7 survival-related machine-learning algorithms for PCa recurrence using nested cross-validation. Multi-omic and drug sensitivity data were also utilized to characterize PCa with various DNA replication stress. We found that the hyperparameter-tuned eXtreme Gradient Boosting model outperformed other tuned models and was therefore used to establish a robust replication stress signature (RSS). RSS demonstrated superior performance over most clinical features and other PCa signatures in predicting PCa recurrence across cohorts. Lower RSS was characterized by enriched metabolism pathways, high androgen activity, and a favorable prognosis. In contrast, higher RSS was significantly associated with TP53, RB1, and PTEN deletion, exhibited increased proliferation and DNA replication stress, and was more immune-suppressive with a higher chance of immunotherapy response. In silico screening identified 13 potential targets (e.g. TOP2A, CDK9, and RRM2) from 2249 druggable targets, and 2 therapeutic agents (irinotecan and topotecan) for RSS-high patients. Additionally, RSS-high patients were more responsive to taxane-based chemotherapy and Poly (ADP-ribose) polymerase inhibitors, whereas RSS-low patients were more sensitive to androgen deprivation therapy. In conclusion, a robust machine-learning framework was used to reveal the great potential of RSS for personalized risk stratification and therapeutic implications in PCa.
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Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Androgênios , Antagonistas de Androgênios/uso terapêutico , Aprendizado de Máquina , Replicação do DNARESUMO
Prenatal exposure to anesthetics has raised increasing attention about the neuronal development in offspring. Animal models are usually used for investigation. As a new drug, esketamine is the s-isoform of ketamine and is twice as potent as the racemic ketamine with less reported adverse effects. Esketamine is currently being used and become more favorable in clinical anesthesia work, including surgeries during pregnancy, yet the effect on the offspring is unknown. The present study aimed to elucidate the effects of gestational administration of esketamine on neuronal development in offspring, using a rat model. Gestational day 14.5 pregnant rats received intravenous injections of esketamine. The postnatal day 0 (P0) hippocampus was digested and cultured in vitro to display the neuronal growth morphology. On Day 4 the in vitro experiments revealed a shorter axon length and fewer dendrite branches in the esketamine group. The results from the EdU- imaging kit showed decreased proliferative capacity in the subventricular zone (SVZ) and dentate gyrus (DG) in both P0 and P30 offspring brains in the esketamine group. Moreover, neurogenesis, neuron maturity and spine density were impaired, resulting in attenuated long-term potentiation (LTP). Compromised hippocampal function accounted for the deficits in neuronal cognition, memory and emotion. The evidence obtained suggests that the neurobehavioral deficit due to prenatal exposure to esketamine may be related to the decrease phosphorylation of CREB and abnormalities in N-methyl-D-aspartic acid receptor subunits. Taken together, these results demonstrate the negative effect of prenatal esketamine exposure on neuronal development in offspring rats. G14.5 esketamine administration influenced the neurobehavior of the offspring in adolescence. Poorer neuronal growth and reduced brain proliferative capacity in late gestation and juvenile pups resulted in impaired P30 neuronal plasticity and synaptic spines as well as abnormalities in NMDAR subunits. Attenuated LTP reflected compromised hippocampal function, as confirmed by behavioral tests of cognition, memory and emotions. This figure was completed on the website of Figdraw.
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Anestésicos , Ketamina , Efeitos Tardios da Exposição Pré-Natal , Feminino , Humanos , Ratos , Animais , Gravidez , Ketamina/toxicidade , Hipocampo/metabolismo , Plasticidade Neuronal , Anestésicos/farmacologia , Receptores de N-Metil-D-Aspartato/metabolismo , Anestesia GeralRESUMO
AIM: To review and clarify the strengths and directions of associations between nephrolithiasis and hypertension (HTN), diabetes mellitus (DM) and gallstones (GS) given the inconsistent results reported in cohort studies. METHODS: Relevant literature was searched in PubMed and EMBASE from inception to July 2019, for cohort studies that examined the relationships between kidney stones and these three diseases among adults. Pooled relative risks (RRs) were calculated by maximally adjusted risk estimates using a random effect model. Subgroup analysis, meta-regression and sensitivity analysis were conducted whenever appropriate. RESULTS: Of 3537 papers, 21 articles with each including 1 to 3 cohorts were identified. In this meta-analysis, nephrolithiasis was reciprocally linked to HTN, DM and GS. Kidney stones were significantly associated with 31%, 33% and 46% higher risks of incident HTN, DM and GS whereas GS was associated with a significantly higher risk of nephrolithiasis (RR: 1.49; 95% CI, 1.28-1.73), followed by HTN (RR: 1.30; 95% CI, 1.11-1.52) and DM (RR: 1.18; 95% CI, 1.07-1.29). Also, females with DM (RR: 1.29; 95% CI, 1.08-1.55) were more likely to develop kidney stones than diabetic male patients (RR: 0.91; 95% CI, 0.75-1.10). CONCLUSION: Although additional studies are needed to confirm these findings and elucidate the mechanisms, this study revealed possible bidirectional associations between nephrolithiasis and HTN, diabetes and GS, which reinforced the notion of nephrolithiasis as a systemic disease that requires comprehensive investigations.
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Diabetes Mellitus/epidemiologia , Cálculos Biliares/epidemiologia , Hipertensão/epidemiologia , Cálculos Renais/epidemiologia , Humanos , Medição de Risco/métodos , Medição de Risco/estatística & dados numéricos , Fatores de RiscoRESUMO
BACKGROUND: Dietary and lifestyle factors may play an important role in the increasing prevalence of nephrolithiasis. We aimed to review and quantify the associations between lifestyle factors and incident nephrolithiasis and suggest lifestyle changes for the primary prevention of nephrolithiasis. METHODS: PubMed, EMBASE, and Cochrane Library were searched up to May 2019, for observational studies and randomized controlled trials (RCTs) that assessed modifiable lifestyle factors and risk of nephrolithiasis in adults. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were computed using a random effects model. The I2 statistic was employed to evaluate heterogeneity. Subgroup analysis, sensitivity analysis and meta-regression were also conducted whenever possible. RESULTS: Fifty relevant articles with 1,322,133 participants and 21,030 cases in total were identified. Prominent risk factors for incident stones were body mass index (1.39,1.27-1.52), dietary sodium (1.38, 1.21-1.56), fructose, meat, animal protein, and soda. In contrast, protective factors included fluid intake (0.55, 0.51-0.60), a Dietary Approaches to Stop Hypertension (DASH) style diet (0.69, 0.64-0.75), alcohol (0.69, 0.56-0.85), water, coffee, tea, vegetables, fruits, dietary fiber, dietary calcium (0.83, 0.76-0.90), and potassium. Vitamin D (1.22, 1.01-1.49) and calcium (1.16, 1.00-1.35) supplementation alone increased the risk of stones in meta-analyses of observational studies, but not in RCTs, where the cosupplementation conferred significant risk. CONCLUSIONS: Several modifiable factors, notably fluid intake, dietary patterns, and obesity, were significantly associated with nephrolithiasis. Long-term RCTs are required to investigate the cost-effectiveness of dietary patterns for stone prevention. The independent and combined effects of vitamin D and calcium supplementation on nephrolithiasis need further elucidation.
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Consumo de Bebidas Alcoólicas , Dieta , Comportamento de Ingestão de Líquido , Estilo de Vida , Nefrolitíase/prevenção & controle , Prevenção Primária , Cálcio da Dieta , Bebidas Gaseificadas , Café , Abordagens Dietéticas para Conter a Hipertensão , Fibras na Dieta , Suplementos Nutricionais , Água Potável , Frutas , Humanos , Potássio na Dieta , Chá , Verduras , Vitamina DRESUMO
Urchinlike W-V-O microspheres have been successfully synthesized for the first time by a one-pot hydrothermal approach. The as-synthesized W-V-O material was characterized by several techniques such as XRD, SEM, TEM, FTIR, EDS, BET, and Raman spectroscopy. The characterization results have revealed that the W-V-O microspheres consist of numerous one-dimensional nanobelts radially grown from the center. The typical nanobelts display rectangular cross sections with lengths of several micrometers, widths of about 50 nm, and thicknesses of approximately 10-20 nm. Vanadium oxides are dispersed highly either on the external surface or inside the channel surface of the hexagonal WO3 structure. In addition, the as-obtained urchin-like W-V-O material was explored as a catalyst for the ammoxidation of 2,4- and 2,6-dichlorotoluene to the corresponding nitriles. The catalytic results have indicated that the W-V-O nanostructures show excellent performance with yields of 2,4- and 2,6-dichlorobenzonitrile respectively reaching up to 77.3 and 75.1%, which are the highest among the previously reported catalysts with two components. The formation process of the urchinlike W-V-O microspheres was simply investigated.
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High temperature (HT), high humidity (HH), and pathogen infection often co-occur and negatively affect plant growth. However, these stress factors and plant responses are generally studied in isolation. The mechanisms of synergistic responses to combined stresses are poorly understood. We isolated the subgroup IIb WRKY family member CaWRKY6 from Capsicum annuum and performed quantitative real-time PCR analysis. CaWRKY6 expression was upregulated by individual or simultaneous treatment with HT, HH, combined HT and HH (HTHH), and Ralstonia solanacearum inoculation, and responded to exogenous application of jasmonic acid (JA), ethephon, and abscisic acid (ABA). Virus-induced gene silencing of CaWRKY6 enhanced pepper plant susceptibility to R. solanacearum and HTHH, and downregulated the hypersensitive response (HR), JA-, ethylene (ET)-, and ABA-induced marker gene expression, and thermotolerance-associated expression of CaHSP24, ER-small CaSHP, and Chl-small CaHSP. CaWRKY6 overexpression in pepper attenuated the HTHH-induced suppression of resistance to R. solanacearum infection. CaWRKY6 bound to and activated the CaWRKY40 promoter in planta, which is a pepper WRKY that regulates heat-stress tolerance and R. solanacearum resistance. CaWRKY40 silencing significantly blocked HR-induced cell death and reduced transcriptional expression of CaWRKY40. These data suggest that CaWRKY6 is a positive regulator of R. solanacearum resistance and heat-stress tolerance, which occurs in part by activating CaWRKY40.
Assuntos
Capsicum/genética , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/imunologia , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/metabolismo , Ralstonia solanacearum/fisiologia , Ácido Abscísico/farmacologia , Sequência de Bases , Capsicum/imunologia , Capsicum/microbiologia , Ciclopentanos/farmacologia , Resistência à Doença , Etilenos/farmacologia , Temperatura Alta , Umidade , Dados de Sequência Molecular , Compostos Organofosforados/farmacologia , Oxilipinas/farmacologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Análise de Sequência de DNA , Estresse Fisiológico , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
In the present work, a novel, floral-like, magnetic sodalite microsphere (SODM) was synthesized in situ by using fly ash (FA) and metakaolin (MK) as raw materials and was used to remove Cd(II) from water. Its magnetism can solve the problems of adsorbent recovery and possible secondary pollution. During the static adsorption, SODM shows a maximum adsorption capacity of 245.17 mg/g. The adsorption of Cd(II) on the SODM surface is spontaneous, exothermic, and physicochemical adsorption, which was evaluated by thermodynamics, kinetics, and isotherm studies. During dynamic adsorption, SODM shows a maximum adsorption capacity of 342.74 mg/g in the simulated solution prepared by the deionized water, compared to 215.88 mg/g in the simulated solution prepared using Xiangsi Lake water from Guangxi Minzu University. At 0.5 g SODM dosage in the dynamic adsorption, the adsorption capacity could rise to 632.81 mg/g. These results demonstrated the excellent Cd (II) adsorption performance of the SODM. The adsorption of cadmium on the SODM surface includes the synergistic effects of electrostatic attraction, ion exchange, and surface coordination reaction. Besides, the SODM shows good regeneration performance in both the deionized water and Xiangsi Lake water. The present study explores SODM as an adsorbent for the Cd (II) removal from wastewater and unbolts the industrial applicability of the SODM in the field of wastewater purification.
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Silicon-containing polyester from tetramethoxysilane, ethylene glycol, and o-Phthalic anhydride were used as encapsulating materials for silicon nano powders (SiNP) via electrospinning, with Polyacrylonitrile (PAN) as spinning additives. In the correct quantities, SiNP could be well encapsulated in nano fibers (200-400 nm) using scanning electron microscopy (SEM). The encapsulating materials were then carbonized to a Si-O-C material at 755 °C (Si@C-SiNF-5 and Si@C-SiNF-10, with different SiNP content). Fiber structure and SiNP crystalline structure were reserved even after high-temperature treatment, as SEM and X-ray diffraction (XRD) verified. When used as lithium ion battery (LIB) anode materials, the cycling stability of SiNPs increased after encapsulation. The capacity of SiNPs decreased to ~10 mAh/g within 30 cycles, while those from Si@C-SiNF-5 and Si@C-SiNF-10 remained over 500 mAh/g at the 30th cycle. We also found that adequate SiNP content is necessary for good encapsulation and better cycling stability. In the anode from Si@C-SiNF-10 in which SiNPs were not well encapsulated, fibers were broken and pulverized as SEM confirmed; thus, its cycling stability is poorer than that from Si@C-SiNF-5.
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Patients with chronic obstructive pulmonary disease (COPD) who exhibit elevated blood eosinophil levels often experience worsened lung function and more severe emphysema. This implies the potential involvement of eosinophils in the development of emphysema. However, the precise mechanisms underlying the development of eosinophil-mediated emphysema remain unclear. In this study, we employed single-cell RNA sequencing to identify eosinophil subgroups in mouse models of asthma and emphysema, followed by functional analyses of these subgroups. Assessment of accumulated eosinophils unveiled distinct transcriptomes in the lungs of mice with elastase-induced emphysema and ovalbumin-induced asthma. Depletion of eosinophils through the use of anti-interleukin-5 antibodies ameliorated elastase-induced emphysema. A particularly noteworthy discovery is that eosinophil-derived cathepsin L contributed to the degradation of the extracellular matrix, thereby leading to emphysema in pulmonary tissue. Inhibition of cathepsin L resulted in a reduction of elastase-induced emphysema in a mouse model. Importantly, eosinophil levels correlated positively with serum cathepsin L levels, which were higher in emphysema patients than those without emphysema. Expression of cathepsin L in eosinophils demonstrated a direct association with lung emphysema in COPD patients. Collectively, these findings underscore the significant role of eosinophil-derived cathepsin L in extracellular matrix degradation and remodeling, and its relevance to emphysema in COPD patients. Consequently, targeting eosinophil-derived cathepsin L could potentially offer a therapeutic avenue for emphysema patients. Further investigations are warranted to explore therapeutic strategies targeting cathepsin L in emphysema patients.
Assuntos
Asma , Enfisema , Doença Pulmonar Obstrutiva Crônica , Enfisema Pulmonar , Animais , Humanos , Camundongos , Asma/genética , Catepsina L/genética , Eosinófilos/metabolismo , Pulmão/metabolismo , Elastase Pancreática , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Enfisema Pulmonar/genética , Enfisema Pulmonar/metabolismoRESUMO
A silicon polyester (Si-PET) was synthesized with ethylene glycol and phthalic anhydride, and then it was carbonized and hydrothermally coated with glucose. The formed SiO x with layered graphene as the 3D network had an amorphous carbon layer. The graphene oxide (rGO) after carbothermal reduction was completely retained in SiO x , which improved the conductivity of the SiO x anode material. SiO x were encapsulated with a flexible amorphous carbon layer on the surface, which can not only improve the electrical performance, but also effectively relieve the huge volume changes of the compound. Further, the key point is that, the solid electrolyte interphase (SEI) film was mainly formed on the surface carbon layer. This would keep a stable SEI film during volume pulverization, and result in a good cycle stability. The SiO x /C-rGO material maintained a reversible capacity of 660 mA h g-1 at a current density of 100 mA g-1 for 100 cycles, a reversible capacity of 469.7 mA h g-1 at a current density of 200 mA g-1 for 300 cycles. The Coulomb efficiency was maintained at 98% except for the first cycle. After long cycling, the electrode expansion was 16%, which was much lower than those of silicon based materials. Therefore, this article provides a cheap, simple, and commercially valuable anode material for lithium batteries.
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Matrix metalloproteinases (MMPs) play a fundamental role in invasion and metastasis of tumor and, recent advances in medicinal chemistry have approached designing of MMP inhibitors with desired structural properties, selectivity and bioavailability. In the present study, novel low-molecular-weight carboxylated chitooligosaccharides (CCOS) were evaluated for their MMP-9 inhibitory effect on human fibrosarcoma cell line (HT1080). In zymography experiments, a clear dose-dependent inhibition on MMP-9 mediated gelatinolytic activities were observed in HT1080 cells following treatment with CCOS. Further, transfection studies carried out with MMP-9 and AP-1 reporter constructs suggested that the observed reduction in MMP-9 expression was due to down-regulation of MMP-9 transcription that mediated via inhibition of AP-1. Moreover, expression of c-Fos protein levels in cytoplasm and nucleus confirmed that CCOS could inhibit AP-1 expression but not its translocation. However, in the presence of CCOS, NF-kappaB and TIMP-1 expression levels remained constant. More importantly, inhibition of MMP-9 expression clearly led to inhibit tumor invasiveness that was studied with reconstituted basement membrane matrix proteins coated synthetic membranes. Taken together, this study discusses MMP-9 inhibition potential of CCOS and their involvement to demote degradation and cellular invasion of extracellular matrix (ECM) and basement membrane. Thus, control of MMP-9 expression by CCOS has considerable significance for the regulation of tumor progression.
Assuntos
Regulação para Baixo/efeitos dos fármacos , Fibrossarcoma/enzimologia , Inibidores de Metaloproteinases de Matriz , Oligossacarídeos/farmacologia , Inibidores de Proteases/farmacologia , Fator de Transcrição AP-1/metabolismo , Western Blotting , Configuração de Carboidratos , Linhagem Celular Tumoral , Fibrossarcoma/metabolismo , Fibrossarcoma/patologia , Humanos , Metaloproteinase 9 da Matriz/metabolismo , Invasividade Neoplásica , Oligossacarídeos/química , Inibidores de Proteases/químicaRESUMO
Even though several studies report the importance of chitosan derivatives for their anticancer activity, no clear information is available to describe the relationship between their charge properties and observed activities. In this research, differently charged chitooligosaccharide (COS) derivatives were synthesized and their anticancer activities were studied using three cancer cell lines, HeLa, Hep3B and SW480. Neutral red and MTT cell viability studies revealed that, highly charged COS derivatives could significantly reduce cancer cell viability, regardless to the positive or negative charge. Further, fluorescence microscopic observations and DNA fragmentation studies confirmed that the anticancer effect of these highly charged COS derivatives were due to necrosis. However, the exact molecular mechanism for anticancer activity of strongly charged COS compared to their poorly charged counterparts is not clear.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Quitosana/química , Quitosana/farmacologia , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Laranja de Acridina , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Quitosana/síntese química , Fragmentação do DNA/efeitos dos fármacos , Eletroquímica , Eletroforese em Gel de Ágar , Etídio , Fibroblastos/efeitos dos fármacos , Corantes Fluorescentes , Humanos , Indicadores e Reagentes , Microscopia de Fluorescência , Necrose , Vermelho Neutro , Oligossacarídeos/síntese química , Sais de Tetrazólio , TiazóisRESUMO
Scavenging activity of hydroxyethyl chitosan sulfate (HCS) against 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl and carbon-centered radical species were studied using electron spin resonance (ESR) spectroscopy. In addition, its antioxidant activity to retard lipid peroxidation was also evaluated in a linoleic acid model system. HCS could scavenge DPPH (33.78%, 2.5 mg/mL) and carbon-centered radicals (67.74%, 0.25 mg/mL) effectively. However, chitosan sulfate did not exhibit any scavenging activity against hydroxyl radicals, but increased its generation. This was different from the published literature and was presumed due to the loss of chelating ability on Fe2+. This assumption could further confirm from the results obtained for Fe2+-ferrozine method that upon sulfation chitooligosaccharides lost its chelation properties. Therefore, HCS can be identified as antioxidant that effectively scavenges carbon centered radicals to retard lipid peroxidation.
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Quitosana/química , Sequestradores de Radicais Livres , Antioxidantes/química , Compostos de Bifenilo , Carbono/química , Quitina/química , Relação Dose-Resposta a Droga , Ácido Edético/farmacologia , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres , Indicadores e Reagentes/farmacologia , Ferro/química , Ácido Linoleico/química , Peroxidação de Lipídeos , Espectroscopia de Ressonância Magnética , Modelos Químicos , Oligossacarídeos/química , Picratos/química , Espectrofotometria , Fatores de TempoRESUMO
Regiospecific oxidation of the primary hydroxyl groups in lacquer polysaccharide (LPL, Mw 6.85 x 10(4)) and its NaIO4 oxidation derivatives (LPLde) to C-6 carboxy groups was achieved with NaOCl in the presence of Tempo and NaBr. Sulfate groups were incorporated into the oxidated polysaccharides using Py.SO3 complex as a reagent. Reactivity of polysaccharide hydroxyl group was C-6 > C-2 > C-4. Sulfate groups were mainly linked to the second hydroxy at C-2 in the products. The results of APTT assay showed after incorporation of carboxyl groups into lacquer polysaccharides, the intrinsic coagulation pathway was promoted, and all sulfated polysaccharides had very weak anticoagulant activity within the scope of studied DS (0.39-1.11). These indicated that carboxyl groups and sulfate groups had the synergistic action. At the same time, the anticoagulant activity increased very slowly with the DS in the second hydroxy. This indicated that 6-O-SO3- in the side chains took an important role in the anticoagulant activity.
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Anticoagulantes/farmacologia , Polissacarídeos/química , Anticoagulantes/química , Coagulação Sanguínea , Brometos/farmacologia , Carbono/química , Óxidos N-Cíclicos/farmacologia , Humanos , Substâncias Macromoleculares/química , Espectroscopia de Ressonância Magnética , Oxigênio/química , Tempo de Tromboplastina Parcial , Estrutura Terciária de Proteína , Compostos de Sódio/farmacologia , Software , Espectroscopia de Infravermelho com Transformada de Fourier , Relação Estrutura-Atividade , Sulfatos/química , ÁrvoresRESUMO
N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) is water-soluble derivative of chitosan (CS), synthesized by the reaction between glycidyl-trimethyl-ammonium chloride and CS. HTCC nanoparticles have been formed based on ionic gelation process of HTCC and sodium tripolyphosphate (TPP). Bovine serum albumin (BSA), as a model protein drug, was incorporated into the HTCC nanoparticles. HTCC nanoparticles were 110-180 nm in size, and their encapsulation efficiency was up to 90%. In vitro release studies showed a burst effect and a slow and continuous release followed. Encapsulation efficiency was obviously increased with increase of initial BSA concentration. Increasing TPP concentration from 0.5 to 0.7 mg/ml promoted encapsulation efficiency from 46.7% to 90%, and delayed release. As for modified HTCC nanoparticles, adding polyethylene glycol (PEG) or sodium alginate obviously decreased the burst effect of BSA from 42% to 18%. Encapsulation efficiency was significantly reduced from 47.6% to 2% with increase of PEG from 1.0 to 20.0 mg/ml. Encapsulation efficiency was increased from 14.5% to 25.4% with increase of alginate from 0.3 to 1.0 mg/ml.
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Quitina/química , Materiais Revestidos Biocompatíveis/química , Preparações de Ação Retardada/química , Teste de Materiais , Nanotubos , Veículos Farmacêuticos/química , Compostos de Amônio Quaternário/química , Soroalbumina Bovina/administração & dosagem , Soroalbumina Bovina/química , Adsorção , Quitina/análogos & derivados , Quitina/isolamento & purificação , Materiais Revestidos Biocompatíveis/síntese química , Materiais Revestidos Biocompatíveis/isolamento & purificação , Preparações de Ação Retardada/síntese química , Preparações de Ação Retardada/isolamento & purificação , Conformação Molecular , Movimento (Física) , Veículos Farmacêuticos/síntese química , Veículos Farmacêuticos/isolamento & purificação , Proteínas/administração & dosagem , Proteínas/química , Compostos de Amônio Quaternário/isolamento & purificação , Propriedades de SuperfícieRESUMO
A new method for the chemical modification of chitosan sulfate was used to prepare N-propanoyl-, N-hexanoyl- and N,O-quaternary substituted chitosan sulfate. Structural analysis by elemental analysis, FTIR, 13C NMR, and 1H NMR spectroscopy, and gel-permeation chromatography showed that these methods could conveniently be used for the introduction of functional groups. The influences of the acyl or quaternary groups on the anticoagulant activity of the polysaccharides were studied with respect to activated partial thromboplastin time (APTT) thrombin time (TT), and prothrombin time (PT). The propanoyl and hexanoyl groups increased the APTT activity, and the propanoyl groups also increased the TT anticoagulant activity slightly, while the N,O-quaternary chitosan sulfate showed only a slight TT coagulant activity.
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Anticoagulantes/química , Anticoagulantes/farmacologia , Quitina/análogos & derivados , Quitina/química , Quitina/farmacologia , Quitosana , Acilação , Anticoagulantes/síntese química , Coagulação Sanguínea/efeitos dos fármacos , Testes de Coagulação Sanguínea , Quitina/síntese química , Humanos , Espectroscopia de Ressonância Magnética , Tempo de Tromboplastina Parcial , Tempo de Protrombina , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de TempoRESUMO
A natural lacquer polysaccharide with complex branches was separated into two fractions, LPH (MW 16.9x10(4)) and LPL (MW 6.85x10(4)). Results of 13C NMR and FT-IR indicated they had the same structure. The treatment of LPL with sodium periodate led to a partial cut-off of side chains with 4-O-methyl-D-glucuronic acid in the terminal. These polysaccharides were sulfated in the presence of Py*SO3/DMSO. Depending on the reaction conditions, the products showed a different degree of sulfation (DS) ranging from 0.57 to 1.57 and different molecular weights ranging from 1.71x10(4) to 3.49x10(4). FT-IR analysis showed the equatorial primary OH at O-6 and the axial secondary OH at O-4 were sulfated. Activated partial thromboplastin time (APTT), prothrombin time and thrombin time (TT) assays showed the sulfated polysaccharides could prolong APTT and TT, but not TP. These activities strongly depended on the DS, the molecular weights (MW) and the branching structure of polysaccharides. DS of above 0.8 was essential for anticoagulant activity. The anticoagulant activity increased with the DS and the molecular weights. The molecular weights played a more important role. The branching structure of polysaccharides increased the activities. In our studies, the sulfated polysaccharides with the DS of 1.15 and the highest MW of 3.49x10(4) had the best blood anticoagulant activities.