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1.
Quant Imaging Med Surg ; 14(1): 144-159, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38223047

RESUMO

Background: In 2020, our center established a Tanner-Whitehouse 3 (TW3) artificial intelligence (AI) system using a convolutional neural network (CNN), which was built upon 9059 radiographs. However, the system, upon which our study is based, lacked a gold standard for comparison and had not undergone thorough evaluation in different working environments. Methods: To further verify the applicability of the AI system in clinical bone age assessment (BAA) and to enhance the accuracy and homogeneity of BAA, a prospective multi-center validation was conducted. This study utilized 744 left-hand radiographs of patients, ranging from 1 to 20 years of age, with 378 boys and 366 girls. These radiographs were obtained from nine different children's hospitals between August and December 2020. The BAAs were performed using the TW3 AI system and were also reviewed by experienced reviewers. Bone age accuracy within 1 year, root mean square error (RMSE), and mean absolute error (MAE) were statistically calculated to evaluate the accuracy. Kappa test and Bland-Altman (B-A) plot were conducted to measure the diagnostic consistency. Results: The system exhibited a high level of performance, producing results that closely aligned with those of the reviewers. It achieved a RMSE of 0.52 years and an accuracy of 94.55% for the radius, ulna, and short bones series. When assessing the carpal series of bones, the system achieved a RMSE of 0.85 years and an accuracy of 80.38%. Overall, the system displayed satisfactory accuracy and RMSE, particularly in patients over 7 years old. The system excelled in evaluating the carpal bone age of patients aged 1-6. Both the Kappa test and B-A plot demonstrated substantial consistency between the system and the reviewers, although the model encountered challenges in consistently distinguishing specific bones, such as the capitate. Furthermore, the system's performance proved acceptable across different genders and age groups, as well as radiography instruments. Conclusions: In this multi-center validation, the system showcased its potential to enhance the efficiency and consistency of healthy delivery, ultimately resulting in improved patient outcomes and reduced healthcare costs.

2.
Mol Biomed ; 4(1): 45, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38032415

RESUMO

The intestinal microbiota is considered to be a forgotten organ in human health and disease. It maintains intestinal homeostasis through various complex mechanisms. A significant body of research has demonstrated notable differences in the gut microbiota of patients with gastrointestinal tumours compared to healthy individuals. Furthermore, the dysregulation of gut microbiota, metabolites produced by gut bacteria, and related signal pathways can partially explain the mechanisms underlying the occurrence and development of gastrointestinal tumours. Therefore, this article summarizes the latest research progress on the gut microbiota and gastrointestinal tumours. Firstly, we provide an overview of the composition and function of the intestinal microbiota and discuss the mechanisms by which the intestinal flora directly or indirectly affects the occurrence and development of gastrointestinal tumours by regulating the immune system, producing bacterial toxins, secreting metabolites. Secondly, we present a detailed analysis of the differences of intestinal microbiota and its pathogenic mechanisms in colorectal cancer, gastric cancer, hepatocellular carcinoma, etc. Lastly, in terms of treatment strategies, we discuss the effects of the intestinal microbiota on the efficacy and toxic side effects of chemotherapy and immunotherapy and address the role of probiotics, prebiotics, FMT and antibiotic in the treatment of gastrointestinal tumours. In summary, this article provides a comprehensive review of the pathogenic mechanisms of and treatment strategies pertaining to the intestinal microbiota in patients with gastrointestinal tumours. And provide a more comprehensive and precise scientific basis for the development of microbiota-based treatments for gastrointestinal tumours and the prevention of such tumours.

3.
Front Genet ; 14: 1122955, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37007954

RESUMO

Objective: To assess the causal effect of systemic iron status by using four biomarkers (serum iron; transferrin saturation; ferritin; total iron-binding capacity) on knee osteoarthritis (OA), hip OA, total knee replacement, and total hip replacement using 2-sample Mendelian randomization (MR) design. Methods: Three instrument sets were used to construct the genetic instruments for the iron status: Liberal instruments (variants associated with one of the iron biomarkers), sensitivity instruments (liberal instruments exclude variants associated with potential confounders), and conservative instruments (variants associated with all four iron biomarkers). Summary-level data for four OA phenotypes, including knee OA, hip OA, total knee replacement, and total hip replacement were obtained from the largest genome-wide meta-analysis with 826,690 individuals. Inverse-variance weighted based on the random-effect model as the main approach was conducted. Weighted median, MR-Egger, and Mendelian randomization pleiotropy residual sum and outlier methods were used as sensitivity MR approaches. Results: Based on liberal instruments, genetically predicted serum iron and transferrin saturation were significantly associated with hip OA and total hip replacement, but not with knee OA and total knee replacement. Statistical evidence of heterogeneity across the MR estimates indicated that mutation rs1800562 was the SNP significantly associated with hip OA in serum iron (odds ratio, OR = 1.48), transferrin saturation (OR = 1.57), ferritin (OR = 2.24), and total-iron binding capacity (OR = 0.79), and hip replacement in serum iron (OR = 1.45), transferrin saturation (OR = 1.25), ferritin (OR = 1.37), and total-iron binding capacity (OR = 0.80). Conclusion: Our study suggests that high iron status might be a causal factor of hip OA and total hip replacement where rs1800562 is the main contributor.

4.
Int J Pharm ; 633: 122567, 2023 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-36586628

RESUMO

The heterogeneity of tumor microenvironment leads to uneven distribution of bio-stimuli. Thus, the multi-site delivery efficiency of responsive drug delivery systems (DDS) inner tumor was always limited. Herein, we proposed a combination strategy of photodynamic therapy (PDT) with ROS-responsive nanosystem which was constructed from dextran-phenylboronic acid pinacol ester conjugates. This combination utilized PDT to amplify and homogenize tissular oxidation level, and achieve effective multi-site response and release of multi-target drugs like gambogic acid (GA). Our research demonstrated the successful preparation of GA and protoporphyrin IX (PpIX) co-loaded nanoparticles, and the PDT-mediated spatiotemporal controlled multi-site drug release in simulated conditions. Furthermore, data from in vitro and in vivo researches on B16F10 cells, HUVEC, and B16F10-bearing C57BL/6 mice potently confirmed the enhanced multi-mechanism regulations of GA mediated by the effective and homogeneous tumoral release. This tactic based on bio-stimuli amplification and homogenization proposes a paradigm to maximize the potency of multi-target drugs.


Assuntos
Nanopartículas , Fotoquimioterapia , Animais , Camundongos , Espécies Reativas de Oxigênio , Dextranos , Camundongos Endogâmicos C57BL , Ensaios Antitumorais Modelo de Xenoenxerto , Sistemas de Liberação de Medicamentos , Linhagem Celular Tumoral , Fármacos Fotossensibilizantes
5.
Front Oncol ; 12: 871169, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35814430

RESUMO

Gastric cancer (GC) ranks as the most common gastrointestinal cancer and is among the leading causes of cancer death worldwide. Glaucocalyxin A (GLA), an entkauranoid diterpene isolated from Rab-dosia japonica var., possesses various bioactivities. To date, the data on the effect of GLA on GC are still minimal, and the molecular mechanisms remain largely unknown. Herein, we found that GLA could significantly inhibit the proliferation, cell adhesion, and invasion of HGT-1, SNU-1, SNU-6, and NCI-N87 GC cells in a dose-dependent manner. GLA enhanced the apoptosis of the GC cells as evidenced by the increased caspase-3 activity and the elevated levels of cleaved caspase-3 and cleaved PARP in GC cells in the presence of GLA. We then showed that the downregulation of Murine Double Minute Clone 2 (MDM2) and Ring Finger Protein 6 (RNF6) by GLA was implicated in the GLA-induced inhibition of the GC cells. Furthermore, MDM2 and RNF6 were identified as the targets of miR-3658 that was downregulated in the GC cells and upregulated by GLA. Moreover, it was shown that miR-3658 was hypermethylated in the GC cells, and GLA could rescue the expression of miR-3658 via demethylation by abrogating EZH2-mediated epigenetic silencing. In addition to the miR-3658-MDM2/RNF6 regulatory axis, activation of the SMG1-UPF mRNA decay pathway contributed to the downregulation of MDM2 and RNF6 by GLA in the GC cells. The inhibitory effect of GLA on gastric cancer and the expression of MDM2 and RNF6 was also validated in in vivo study. Our findings suggest that has the therapeutic potential for GC by downregulating oncogenes via posttranscriptional regulation.

6.
Genet Res (Camb) ; 2022: 8727566, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35645616

RESUMO

Background: Heart failure (HF) is defined as the inability of the heart's systolic and diastolic function to properly discharge blood flow from the veins to the heart. The goal of our research is to look into the possible mechanism that causes HF. Methods: The GSE5406 database was used for screening the differentially expressed genes (DEGs). Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Protein-Protein Interaction (PPI) network were applied to analyze DEGs. Besides, cell counting Kit-8 (CCK-8) was conducted to observe the knockdown effect of hub genes on cell proliferation. Results: Finally, 377 upregulated and 461 downregulated DEGs came out, enriched in the extracellular matrix organization and gap junction. According to GSEA results, Hoft cd4 positive alpha beta memory t cell bcg vaccine age 18-45 yo id 7 dy top 100 deg ex vivo up, Sobolev t cell pandemrix age 18-64 yo 7 dy dn, and so on were significantly related to gene set GSE5406. 7 hub genes, such as COL1A1, UBB, COL3A1, HSP90AA1, MYC, STAT3 and MAPK1, were selected from PPI networks. CCK-8 indicated silencing of STAT3 promoted the proliferation of H9C2 cells and silencing of UBB inhibited the proliferation of H9C2 cells. Conclusion: Our analysis reveals that COL1A1, UBB, COL3A1, HSP90AA1, MYC, STAT3, and MAPK1 might promote the progression of HF and become the biomarkers for diagnosis and treatment of HF.


Assuntos
Redes Reguladoras de Genes , Insuficiência Cardíaca , Adolescente , Adulto , Biomarcadores Tumorais/genética , Regulação Neoplásica da Expressão Gênica , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/terapia , Humanos , Pessoa de Meia-Idade , Adulto Jovem
8.
Front Nutr ; 9: 853115, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35340550

RESUMO

A novel neutral polysaccharide designated as PAP1b was isolated from Areca catechu L. by hot water extraction, ethanol precipitation, and column chromatography. PAP1b was mainly composed of mannose, galactose, xylose, and arabinose in a ratio of 4.1:3.3:0.9:1.7, with an average molecular weight of 37.3 kDa. Structural characterization indicated that the backbone of PAP1b appeared to be composed mainly of → 6-ß-Manp-(1 →, → 4)-α-Galp-(1 → and → 3,6)-ß-Manp-(1 →) residues with some branches, and terminal of (1 →)-linked-ß-Manp residues. The results of bioactivity experiments showed that PAP1b had antioxidant in vitro, esspecially on scavenging DPPH and hydroxyl radicals. Therefore, the polysaccharide from Areca catechu L. could be used as a potential antioxidant in functional food.

9.
Transl Oncol ; 18: 101362, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35151092

RESUMO

Cervical cancer is one of the most common malignancies in women, with a poor survival rate. Thus, there is a need to define effective combination strategies to improve therapy. In this study, we report that dsRNA poly(I:C) up-regulated the expression of IFNß and apoptosis-associated genes in cervical cancer cells, activating both intrinsic and extrinsic apoptotic pathways, and eventually inducing cell death. Similarly, proteasome inhibitors also effectively induced cervical cancer cell apoptosis, probably through prevention of p53 degradation, inhibiting NF-κB signal activation and decreasing BCL-2 expression. Importantly, the combination of poly(I:C) with proteasome inhibitors enhanced caspase-8 and caspase-9 activation, and synergistically induced cervical cancer cell apoptosis. Both activated p38 signals and increased ROS levels, and their combination extended these effects. Collectively, we show that the activation of multiple pro-apoptotic pathways by poly(I:C) and proteasome inhibitors underpin a synergistic effect on inducing cervical cancer cell death, suggesting a potential therapeutic combination with clinical relevance.

10.
Cell Death Dis ; 12(11): 1045, 2021 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-34732698

RESUMO

Rapid adaptation to a hypoxic environment is an unanswered question that we are committed to exploring. At present, there is no suitable strategy to achieve rapid hypoxic adaptation. Here, we demonstrate that fasting preconditioning for 72 h reduces tissue injuries and maintains cardiac function, consequently significantly improving the survival rates of rats under extreme hypoxia, and this strategy can be used for rapid hypoxic adaptation. Mechanistically, fasting reduces blood glucose and further suppresses tissue mTOR activity. On the one hand, fasting-induced mTOR inhibition reduces unnecessary ATP consumption and increases ATP reserves under acute hypoxia as a result of decreased protein synthesis and lipogenesis; on the other hand, fasting-induced mTOR inhibition improves mitochondrial oxygen utilization efficiency to ensure ATP production under acute hypoxia, which is due to the significant decrease in ROS generation induced by enhanced mitophagy. Our findings highlight the important role of mTOR in acute hypoxic adaptation, and targeted regulation of mTOR could be a new strategy to improve acute hypoxic tolerance in the body.


Assuntos
Adaptação Fisiológica , Jejum/fisiologia , Hipóxia/fisiopatologia , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Doença Aguda , Trifosfato de Adenosina/biossíntese , Animais , Técnicas de Silenciamento de Genes , Lipogênese , Masculino , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Proteínas Mitocondriais/metabolismo , Mitofagia , Modelos Biológicos , Miocárdio/patologia , Miocárdio/ultraestrutura , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Oxigênio/metabolismo , Consumo de Oxigênio , Biossíntese de Proteínas , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Análise de Sobrevida
11.
Zhongguo Zhong Yao Za Zhi ; 45(15): 3707-3712, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32893562

RESUMO

Curcumin was used to interfere with acute pancreatitis model rats to explore its possible mechanism. One hundred and twenty rats were randomly divided into blank group, model group, model+curcumin group, model+mock+curcumin group, model+antagonist+curcumin group and model+curcumin+LY294002 group, with 20 rats in each group. The wet/dry weight ratio of pancreatic tissue was measured and the pathological changes of pancreas were observed by HE staining. The apoptosis was detected by TUNEL staining; the levels of serum amylase, lipase, Bcl-2 and Bax were detected by ELISA, and the levels of PI3 K, Akt and p-Akt in pancreatic tissue were measured by Western blot. HE staining showed that curcumin could improve the pathological changes of pancreas and reduce the pathological score of pancreas, while ELISA results showed that curcumin could decrease the levels of amylase, lipase and Bax in peripheral serum and increase the concentration of Bcl-2. Western blot results showed that the expression levels of PI3 K and p-Akt in pancreatic tissue of model rats were up-regulated after the intervention of curcumin, and the apoptosis rate of pancreatic cells decreased in TUNEL staining. The above effects could be weakened by miR-198 antagonist and PI3 K-Akt signal pathway inhibitor LY294002. In conclusion, curcumin has an ideal effect on acute pancreatitis, and its mechanism may be mediated by miR-198-PI3 K-Akt axis.


Assuntos
Curcumina , MicroRNAs , Pancreatite , Doença Aguda , Animais , Apoptose , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Ratos , Ratos Sprague-Dawley , Transdução de Sinais
12.
ACS Appl Mater Interfaces ; 12(13): 14770-14783, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32149497

RESUMO

Despite the great potential of combination therapy based on siRNA and chemotherapeutics, an efficient vehicle with abilities of well drug co-loading, synchronizing in vivo trafficking, and target-specific co-burst release remains elusive, which results in a suboptimal synergistic potency. Herein, a novel chitosan amphiphile (PEI-ss-HECS-ss-OA, HSPO) with glutathione (GSH)-reversible cationization and hydrophobicization by polyethylenimine (PEI) and octylamine (OA), respectively, was developed for this purpose. HSPO spontaneously assembled in aqueous solution to be a micellar system and effectively co-encapsulated the two drugs with an adjustable dosage ratio. With a surface charge inversion strategy by hyaluronic acid (HA) coating, the HA(HSPO) co-delivery micelles with a negative surface charge (-21.45 ± 1.44 mV) and suitable size (192.52 ± 7.41 nm) selectively accumulated into CD44 overexpressed A549 tumors through a combination of passive and active targeting mechanism. Then, tumor cytoplasm-selective co-burst release was obtained through GSH triggered collapse of the amphiphilic assembly alongside a decrease of positive charge condensation, finally leading to an enhanced synergistic antitumor effect with a superior inhibition ratio of 86.63%. Overall, this study validated the great promise of HSPO as an efficient site-specific rapid co-trafficking vehicle of siRNA and chemotherapeutics for a remarkable synergistic tumor inhibition.


Assuntos
Antineoplásicos Fitogênicos/metabolismo , Quitosana/química , RNA Interferente Pequeno/metabolismo , Células A549 , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/uso terapêutico , Cátions/química , Citoplasma/metabolismo , Portadores de Fármacos/química , Feminino , Glutationa/química , Humanos , Ácido Hialurônico/química , Camundongos , Camundongos Nus , Micelas , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Paclitaxel/química , Paclitaxel/metabolismo , Tamanho da Partícula , Polietilenoimina/química , RNA Interferente Pequeno/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
13.
PLoS One ; 13(10): e0205875, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30339694

RESUMO

Hirudo nipponia (known as Shui Zhi in Chinese) is a well-known Chinese medicine with numerous active ingredients in its body, especially in its saliva. This native Chinese blood-sucking leech has been used for therapeutic purposes since before 100 AD. Modern Chinese physicians use it for a wide range of diseases. Genomic data and molecular information about the pharmacologically active substances produced by this medicinal leech are presently unavailable despite this organism's medicinal importance. In this study, we performed transcriptome profiling of the salivary glands of medicinal leech H. nipponia using the Illumina platform. In total, 84,657,362 clean reads were assembled into 50,535 unigenes. The obtained unigenes were compared to public databases. Furthermore, a unigene sequence similarity search and comparisons with the whole transcriptome of medical leech were performed to identify potential proteins. Finally, more than 21 genes were predicted to be involved in anticoagulatory, antithrombotic, antibacterial, anti-inflammatory and antitumor processes, which might play important roles in the treatment of various diseases. This study is the first analysis of a sialotranscriptome in H. nipponia. The transcriptome profile will shed light on its genetic background and provide a useful tool to deepen our understanding of the medical value of H. nipponia.


Assuntos
Hirudo medicinalis/metabolismo , Saliva/metabolismo , Glândulas Salivares/metabolismo , Animais , Antibacterianos , Anticoagulantes , Antineoplásicos , China , DNA Complementar/metabolismo , Perfilação da Expressão Gênica , Biblioteca Gênica , Genômica , Medicina Tradicional Chinesa , Filogenia , Alinhamento de Sequência , Transcriptoma
14.
Org Lett ; 19(22): 6228-6231, 2017 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-29095631

RESUMO

A transition-metal-free oxidative formal [3 + 2 + 1] cycloaddition for the synthesis of symmetrical and unsymmetrical 2,4-disubstituted 1,3,5-triazines has been first demonstrated. The reaction is involved in a domino C-H amination of alkyl ethers with amidines, C-O cleavage, nucleophilic addition, condensation, and an oxidative aromatization process. Notably, two C-N bonds were constructed in one pot, and alkyl ethers were employed as a novel carbon source of 1,3,5-triazines. The preliminary mechanistic studies revealed the reaction underwent a radical pathway.

15.
Oncol Rep ; 37(4): 2441-2448, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28260021

RESUMO

Emerging evidence has shown that microRNAs (miRNAs) play critical roles in tumor development and progression. miR-134 has been found to act as a tumor-suppressor in numerous types of cancers. However, little is known concerning the potential role of miR-134 in gastric carcinogenesis. In the present study, we found that miR-134 was highly downregulated in gastric cancer tissues and cell lines when compared with levels in their adjacent non-tumor tissues and the normal human gastric epithelial cell line GES-1. Additionally, overexpression of miR-134 was accompanied by reduced cell proliferation in vitro and decreased tumor size in vivo. Further investigation by luciferase reporter assay indicated that Golgi phosphoprotein 3 (GOLPH3), a potent oncogene, was a direct target of miR-134. The activity of a luciferase reporter carrying the miR-134 binding site in the 3'-untranslated region (3'-UTR) of GOLPH3 was repressed by overexpression of miR-134, while a mutation in the 3'-UTR of GOLPH3 abrogated this effect, indicating that GOLPH3 is a target gene of miR-134. Overexpression of GOLPH3 blocked the antiproliferative effect of pre-miR-134 in gastric carcinoma cells. Furthermore, overexpression of miR-134 was associated with decreased phosphorylation of AKT, mTOR and S6K. Taken together, these data suggest that miR-134 regulates gastric cancer cell proliferation, at least potentially, through downregulation of the GOLPH3 gene, implicating a candidate tumor-suppressor miRNA in the pathogenesis of gastric cancer.


Assuntos
Proteínas de Membrana/genética , MicroRNAs/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Regiões 3' não Traduzidas , Animais , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Transplante de Neoplasias
16.
An. acad. bras. ciênc ; 89(3,supl): 2033-2041, 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-886795

RESUMO

ABSTRACT The effect on different three carbon source (i.e. glucose, fructose and sucrose) on production, chemical characterization and antioxidant activity of exopolysaccharide (EPS) produced by Phellinus vaninii Ljup was investigated in this study. Amongst carbon sources examined, glucose and sucrose were favorable for the mycelia growth, while the maximum EPS yield was achieved when sucrose was employed. The predominant carbohydrate compositions in EPSs identified were gluconic acid, glucose, mannose and galactose acid. Then, FT-IR spectral analysis revealed prominent characteristic groups in EPSs. EPSs molecule exist as nearly globular shape form in aqueous solution. The variation also affects antioxidant activities by investigated by using hydroxyl and DPPH radical scavenging assay. Sucrose was best carbon source from the viewpoint of antioxidant activity due to the relatively high contents of galactose in the EPS with moderate molecular weight and polydispersity.


Assuntos
Polissacarídeos Bacterianos/metabolismo , Carbono/metabolismo , Polissacarídeos Fúngicos , Sacarose/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Frutose/metabolismo , Glucose/metabolismo
17.
Saudi Pharm J ; 24(3): 241-4, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27275108

RESUMO

To explore material basis of in vitro anti-proliferative activity of leukemia cell K562 of petroleum ether phase of product resulting from Galium aparine L. 60% ethanol extraction, the experiment adopts column chromatography combined with thin layer preparation, isolates and purifies petroleum ether, conducts structural identification of obtained single compound and applies MTT method for viability assay of in vitro anti-proliferative activity of leukemia cell K562. Experimental results show that G. aparine L. petroleum ether contains mainly ß-sitosterol, daucosterol and dibutyl phthalate and other substances. Under experimental conditions, the three could inhibit the proliferation of leukemia cell K562 with dose-effect and time-effect relationship, of which dibutyl phthalate has strongest activity. Dibutyl phthalate with excellent activity, ß-sitosterol with rich content and moderate effect should be the main contributor to its biological activity.

18.
Cell Metab ; 5(3): 167-79, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17339025

RESUMO

Insulin resistance occurs in 20%-25% of the human population, and the condition is a chief component of type 2 diabetes mellitus and a risk factor for cardiovascular disease and certain forms of cancer. Herein, we demonstrate that the sphingolipid ceramide is a common molecular intermediate linking several different pathological metabolic stresses (i.e., glucocorticoids and saturated fats, but not unsaturated fats) to the induction of insulin resistance. Moreover, inhibition of ceramide synthesis markedly improves glucose tolerance and prevents the onset of frank diabetes in obese rodents. Collectively, these data have two important implications. First, they indicate that different fatty acids induce insulin resistance by distinct mechanisms discerned by their reliance on sphingolipid synthesis. Second, they identify enzymes required for ceramide synthesis as therapeutic targets for combating insulin resistance caused by nutrient excess or glucocorticoid therapy.


Assuntos
Ceramidas/metabolismo , Ácidos Graxos/metabolismo , Glucocorticoides/metabolismo , Resistência à Insulina , Obesidade/metabolismo , Animais , Ceramidas/biossíntese , Diabetes Mellitus Tipo 2/metabolismo , Gorduras Insaturadas/metabolismo , Humanos , Metabolismo dos Lipídeos , Masculino , Camundongos , Camundongos Knockout , Oxirredutases/genética , Ratos , Ratos Sprague-Dawley , Esfingolipídeos/metabolismo
19.
Protein Expr Purif ; 41(1): 68-76, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15802223

RESUMO

Monoclonal antibody A21 reacts specifically with the extracellular domain of p185c-erbB-2 oncoprotein, a member of the epidermal growth factor receptor family. In a previous study, we constructed a single-chain chimeric antibody, assembled using an A21 single-chain Fv antibody and a human IgG1 Fc fragment. In this study, we expressed this chimeric antibody using a CHO-GS system, and developed a simple and efficient method for its purification. After only one step using affinity purification, the recovery rate and purity of the antibody attained was 60 and 91%, respectively. After a second step, using reverse phase HPLC purification, the purity was above 99%. The high purity of the recombinant antibody allowed us to identify a number of its intrinsic molecular properties, including antigen binding activity, measurement of affinity constant, N-terminal sequencing, and mass spectrometer analysis. These results further augment the potential of this recombinant antibody to be a drug candidate for cancer therapy.


Assuntos
Anticorpos Monoclonais/isolamento & purificação , Receptor ErbB-2/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/metabolismo , Afinidade de Anticorpos , Citotoxicidade Celular Dependente de Anticorpos , Ligação Competitiva , Células CHO , Cromatografia de Afinidade , Cromatografia Líquida de Alta Pressão , Cricetinae , Expressão Gênica , Humanos , Técnicas In Vitro , Camundongos , Dados de Sequência Molecular , Neoplasias/terapia , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Transfecção
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