Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
J Magn Reson Imaging ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38859600

RESUMO

BACKGROUND: Traditional biopsies pose risks and may not accurately reflect soft tissue sarcoma (STS) heterogeneity. MRI provides a noninvasive, comprehensive alternative. PURPOSE: To assess the diagnostic accuracy of histological grading and prognosis in STS patients when integrating clinical-imaging parameters with deep learning (DL) features from preoperative MR images. STUDY TYPE: Retrospective/prospective. POPULATION: 354 pathologically confirmed STS patients (226 low-grade, 128 high-grade) from three hospitals and the Cancer Imaging Archive (TCIA), divided into training (n = 185), external test (n = 125), and TCIA cohorts (n = 44). 12 patients (6 low-grade, 6 high-grade) were enrolled into prospective validation cohort. FIELD STRENGTH/SEQUENCE: 1.5 T and 3.0 T/Unenhanced T1-weighted and fat-suppressed-T2-weighted. ASSESSMENT: DL features were extracted from MR images using a parallel ResNet-18 model to construct DL signature. Clinical-imaging characteristics included age, gender, tumor-node-metastasis stage and MRI semantic features (depth, number, heterogeneity at T1WI/FS-T2WI, necrosis, and peritumoral edema). Logistic regression analysis identified significant risk factors for the clinical model. A DL clinical-imaging signature (DLCS) was constructed by incorporating DL signature with risk factors, evaluated for risk stratification, and assessed for progression-free survival (PFS) in retrospective cohorts, with an average follow-up of 23 ± 22 months. STATISTICAL TESTS: Logistic regression, Cox regression, Kaplan-Meier curves, log-rank test, area under the receiver operating characteristic curve (AUC),and decision curve analysis. A P-value <0.05 was considered significant. RESULTS: The AUC values for DLCS in the external test, TCIA, and prospective test cohorts (0.834, 0.838, 0.819) were superior to clinical model (0.662, 0.685, 0.694). Decision curve analysis showed that the DLCS model provided greater clinical net benefit over the DL and clinical models. Also, the DLCS model was able to risk-stratify patients and assess PFS. DATA CONCLUSION: The DLCS exhibited strong capabilities in histological grading and prognosis assessment for STS patients, and may have potential to aid in the formulation of personalized treatment plans. TECHNICAL EFFICACY: Stage 2.

2.
Eur Radiol ; 33(10): 6781-6793, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37148350

RESUMO

OBJECTIVES: This study evaluated the ability of a preoperative contrast-enhanced CT (CECT)-based radiomics nomogram to differentiate benign and malignant primary retroperitoneal tumors (PRT). METHODS: Images and data from 340 patients with pathologically confirmed PRT were randomly placed into training (n = 239) and validation sets (n = 101). Two radiologists independently analyzed all CT images and made measurements. Key characteristics were identified through least absolute shrinkage selection combined with four machine-learning classifiers (support vector machine, generalized linear model, random forest, and artificial neural network back propagation) to create a radiomics signature. Demographic data and CECT characteristics were analyzed to formulate a clinico-radiological model. Independent clinical variables were merged with the best-performing radiomics signature to develop a radiomics nomogram. The discrimination capacity and clinical value of three models were quantified by the area under the receiver operating characteristics (AUC), accuracy, and decision curve analysis. RESULTS: The radiomics nomogram was able to consistently differentiate between benign and malignant PRT in the training and validation datasets, with AUCs of 0.923 and 0.907, respectively. Decision curve analysis manifested that the nomogram achieved higher clinical net benefits than did separate use of the radiomics signature and clinico-radiological model. CONCLUSIONS: The preoperative nomogram is valuable for differentiating between benign and malignant PRT; it can also aid in treatment planning. KEY POINTS: • A noninvasive and accurate preoperative determination of benign and malignant PRT is crucial to identifying suitable treatments and predicting disease prognosis. • Associating the radiomics signature with clinical factors facilitates differentiation of malignant from benign PRT with improved diagnostic efficacy (AUC) and accuracy from 0.772 to 0.907 and from 0.723 to 0.842, respectively, compared with the clinico-radiological model alone. • For some PRT with anatomically special locations and when biopsy is extremely difficult and risky, a radiomics nomogram may provide a promising preoperative alternative for distinguishing benignity and malignancy.


Assuntos
Radiologia , Neoplasias Retroperitoneais , Humanos , Neoplasias Retroperitoneais/diagnóstico por imagem , Nomogramas , Área Sob a Curva , Tomografia Computadorizada por Raios X , Estudos Retrospectivos
3.
Front Oncol ; 12: 897676, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35814362

RESUMO

Objectives: To build and evaluate a deep learning radiomics nomogram (DLRN) for preoperative prediction of lung metastasis (LM) status in patients with soft tissue sarcoma (STS). Methods: In total, 242 patients with STS (training set, n=116; external validation set, n=126) who underwent magnetic resonance imaging were retrospectively enrolled in this study. We identified independent predictors for LM-status and evaluated their performance. The minimum redundancy maximum relevance (mRMR) method and least absolute shrinkage and selection operator (LASSO) algorithm were adopted to screen radiomics features. Logistic regression, decision tree, random forest, support vector machine (SVM), and adaptive boosting classifiers were compared for their ability to predict LM. To overcome the imbalanced distribution of the LM data, we retrained each machine-learning classifier using the synthetic minority over-sampling technique (SMOTE). A DLRN combining the independent clinical predictors with the best performing radiomics prediction signature (mRMR+LASSO+SVM+SMOTE) was established. Area under the receiver operating characteristics curve (AUC), calibration curves, and decision curve analysis (DCA) were used to assess the performance and clinical applicability of the models. Result: Comparisons of the AUC values applied to the external validation set revealed that the DLRN model (AUC=0.833) showed better prediction performance than the clinical model (AUC=0.664) and radiomics model (AUC=0.799). The calibration curves indicated good calibration efficiency and the DCA showed the DLRN model to have greater clinical applicability than the other two models. Conclusion: The DLRN was shown to be an accurate and efficient tool for LM-status prediction in STS.

4.
Front Oncol ; 11: 659905, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34012922

RESUMO

OBJECTIVES: To investigate the efficacy of multi-parametric MRI-based radiomics nomograms for preoperative distinction between benign and malignant sinonasal tumors. METHODS: Data of 244 patients with sinonasal tumor (training set, n=192; test set, n=52) who had undergone pre-contrast MRI, and 101 patients who underwent post-contrast MRI (training set, n=74; test set, n=27) were retrospectively analyzed. Independent predictors of malignancy were identified and their performance were evaluated. Seven radiomics signatures (RSs) using maximum relevance minimum redundancy (mRMR), and the least absolute shrinkage selection operator (LASSO) algorithm were established. The radiomics nomograms, comprising the clinical model and the RS algorithms were built: one based on pre-contrast MRI (RNWOC); the other based on pre-contrast and post-contrast MRI (RNWC). The performances of the models were evaluated with area under the curve (AUC), calibration, and decision curve analysis (DCA) respectively. RESULTS: The efficacy of the clinical model (AUC=0.81) of RNWC was higher than that of the model (AUC=0.76) of RNWOC in the test set. There was no significant difference in the AUC of radiomic algorithms in the test set. The RS-T1T2 (AUC=0.74) and RS-T1T2T1C (RSWC, AUC=0.81) achieved a good distinction efficacy in the test set. The RNWC and the RNWOC showed excellent distinction (AUC=0.89 and 0.82 respectively) in the test set. The DCA of the nomograms showed better clinical usefulness than the clinical models and radiomics signatures. CONCLUSIONS: The radiomics nomograms combining the clinical model and RS can be accurately, safely and efficiently used to distinguish between benign and malignant sinonasal tumors.

5.
Eur Radiol ; 31(5): 2886-2895, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33123791

RESUMO

OBJECTIVES: Preoperative differentiation between benign lymphoepithelial lesion (BLEL) and mucosa-associated lymphoid tissue lymphoma (MALToma) in the parotid gland is important for treatment decisions. The purpose of this study was to develop and validate a CT-based radiomics nomogram combining radiomics signature and clinical factors for the preoperative differentiation of BLEL from MALToma in the parotid gland. METHODS: A total of 101 patients with BLEL (n = 46) or MALToma (n = 55) were divided into a training set (n = 70) and validation set (n = 31). Radiomics features were extracted from non-contrast CT images, a radiomics signature was constructed, and a radiomics score (Rad-score) was calculated. Demographics and CT findings were assessed to build a clinical factor model. A radiomics nomogram combining the Rad-score and independent clinical factors was constructed using multivariate logistic regression analysis. The performance levels of the nomogram, radiomics signature, and clinical model were evaluated and validated on the training and validation datasets, and then compared among the three models. RESULTS: Seven features were used to build the radiomics signature. The radiomics nomogram incorporating the clinical factors and radiomics signature showed favorable predictive value for differentiating parotid BLEL from MALToma, with AUCs of 0.983 and 0.950 for the training set and validation set, respectively. Decision curve analysis showed that the nomogram outperformed the clinical factor model in terms of clinical usefulness. CONCLUSIONS: The CT-based radiomics nomogram incorporating the Rad-score and clinical factors showed favorable predictive efficacy for differentiating BLEL from MALToma in the parotid gland, and may help in the clinical decision-making process. KEY POINTS: • Differential diagnosis between BLEL and MALToma in parotid gland is rather difficult by conventional imaging modalities. • A radiomics nomogram integrated with the radiomics signature, demographics, and CT findings facilitates differentiation of BLEL from MALToma with improved diagnostic efficacy.


Assuntos
Nomogramas , Glândula Parótida , Diagnóstico Diferencial , Humanos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
6.
Biomed Res Int ; 2019: 1341370, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31016184

RESUMO

A novel lectin (ABL) was purified from the dried fruiting bodies of Agaricus bitorquis. An efficient 3-step purification protocol involved two consecutive steps of ion exchange chromatography on Q-Sepharose and SP-Sepharose and gel filtration by FPLC on Superdex 75. ABL is a monomeric protein with the molecular mass of 27.6 kDa, which is different from other lectins from genus Agaricus. Its N-terminal amino acid sequence is EYTISIRVYQTNPKGFNRPV which is unique and sharing considerably high similarity of other mushroom lectins. The hemagglutinating activity of the lectin was inhibited by inulin. Based on hemagglutination tests, ABL prefers rabbit, human type A, and AB erythrocytes to human type B and O erythrocytes. The lectin inhibits the activity of HIV-1 reverse transcriptase and the proliferation of leukemia cell (L1210) with an IC50 value of 4.69 and 4.97 µM, respectively. Furthermore, ABL demonstrates the highest mitogenic activity with a response of 24177.7 ± 940.6 [3H-methyl] thymidine counts per minute (CPM) at a concentration of 0.91 µM.


Assuntos
Agaricales/química , Agaricus/química , Proliferação de Células/efeitos dos fármacos , Transcriptase Reversa do HIV/antagonistas & inibidores , Inulina/metabolismo , Lectinas/farmacologia , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Hemaglutinação/efeitos dos fármacos , Testes de Hemaglutinação/métodos , Células Hep G2 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Coelhos
7.
World J Clin Cases ; 6(16): 1210-1216, 2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30613685

RESUMO

BACKGROUND: Chondromyxoid fibroma (CMF) is a rare benign bone tumour of cartilaginous origin, which usually affects the metaphysis of the long bone. Involvement of the temporal bone is extremely rare. Patients with CMF in the temporal bone can present some neurological deficits due to involvement of surrounding neural structures. CASE SUMMARY: We present the first case of histopathologically proven CMF originating in the temporal bone and involving the hypoglossal canal in a 40-year-old woman. Hypoglossal nerve paralysis was identified on the cranial nerve examination. The patient underwent surgical excision and was neurologically normal except for mild left facial palsy on 5-mo follow-up examination after surgery. In the current report, the major characteristics and computed tomography/magnetic resonance imaging features of the lesion are discussed. Furthermore, previous literature regarding this pathology is reviewed. CONCLUSION: The current study presents the first case of temporal bone CMF involving the hypoglossal canal.

8.
Biomed Res Int ; 2014: 417461, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25540778

RESUMO

A novel laccase was isolated and purified from fermentation mycelia of mushroom Coprinus comatus with an isolation procedure including three ion-exchange chromatography steps on DEAE-cellulose, CM-cellulose, and Q-Sepharose and one gel-filtration step by fast protein liquid chromatography on Superdex 75. The purified enzyme was a monomeric protein with a molecular weight of 64 kDa. It possessed a unique N-terminal amino acid sequence of AIGPVADLKV, which has considerably high sequence similarity with that of other fungal laccases, but is different from that of C. comatus laccases reported. The enzyme manifested an optimal pH value of 2.0 and an optimal temperature of 60°C using 2,2'-azinobis(3-ethylbenzothiazolone-6-sulfonic acid) diammonium salt (ABTS) as the substrate. The laccase displayed, at pH 2.0 and 37°C, K(m) values of 1.59 mM towards ABTS. It potently suppressed proliferation of tumor cell lines HepG2 and MCF7, and inhibited human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) with an IC50 value of 3.46 µM, 4.95 µM, and 5.85 µM, respectively, signifying that it is an antipathogenic protein.


Assuntos
Proliferação de Células/efeitos dos fármacos , Coprinus/enzimologia , Lacase/farmacologia , Neoplasias/tratamento farmacológico , Coprinus/química , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Transcriptase Reversa do HIV/biossíntese , Transcriptase Reversa do HIV/efeitos dos fármacos , HIV-1/efeitos dos fármacos , Células Hep G2 , Humanos , Lacase/genética , Lacase/isolamento & purificação , Células MCF-7 , Micélio/química , Micélio/enzimologia , Neoplasias/patologia
9.
Biotechnol Appl Biochem ; 60(4): 393-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24033593

RESUMO

A 36-kDa protein, with an N-terminal sequence highly homologous to polygalacturonase (PG) inhibiting proteins, was isolated from small brown-eyed cowpea seeds. The protein was unadsorbed on diethylaminoethyl cellulose but adsorbed on both Affi-gel blue gel and SP-sepharose. It inhibited mycelial growth in the fungus Mycosphaerella arachidicola with an half-maximal (50%) inhibitory concentration (IC50 ) of 3.3 µM. It reduced [methyl-(3) H] thymidine incorporation into MBL2 lymphoma and L1210 leukemia cells with an IC50 of 7.4 and 5.4 µM, respectively. It inhibited human immunodeficiency virus type 1 (HIV-1) reverse transcriptase with an IC50 of 12.9 µM. However, it did not inhibit PG. The potent antifungal and antitumor activities of the protein suggest that it can be developed into an antifungal agent for combating M. arachidicola invasion in crops and an agent for cancer therapy in humans.


Assuntos
Antifúngicos/isolamento & purificação , Fabaceae/química , Transcriptase Reversa do HIV/antagonistas & inibidores , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Inibidores da Transcriptase Reversa/isolamento & purificação , Sementes/química , Sequência de Aminoácidos , Antifúngicos/química , Antifúngicos/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Fungos/efeitos dos fármacos , Humanos , Dados de Sequência Molecular , Proteínas de Plantas/química , Inibidores da Transcriptase Reversa/química , Inibidores da Transcriptase Reversa/farmacologia
10.
Protein Pept Lett ; 20(7): 767-74, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23092133

RESUMO

A novel lectin was isolated from the dried fruiting bodies of the wild mushroom Paxillus involutus. Isolation was conducted by anion exchange chromatography on DEAE-Cellulose, Q-Sepharose and gel filtration on Superdex 75 using a fast protein liquid chromatography (FPLC) system. This lectin had a molecular mass of 28 kDa and was composed of four identical subunits, each with a molecular mass of 7 kDa. N-terminal amino acid sequence of the P. involutus lectin was determined to be CTCAVFLNNTTVKS, which showed a low level of similarity to mushroom lectin sequences reported previously. The biochemical properties of this lectin were determined, and the hemagglutinating activity was inhibited by inulin and O-Nitrophenyl-ß-D-galacto-pyranoside. Additionally, Ca2+, Zn2+, Cd2+, Fe2+, and Al3+ inhibited its hemagglutinating activity, while Cu2+ promoted this activity. This lectin exhibited poor thermostability and was sensitive to HCl, but it had a high tolerance to NaOH exposure. In terms of biological properties, this lectin manifested antiphytovirus activity towards tobacco mosaic virus (TMV) with a 70.61% inhibition at a concentration of 200 µg/mL. This lectin was devoid of inhibitory activities toward pathogenic fungi and HIV-1 reverse transcriptase, and antiproliferative activities were observed in tumor cell lines including lung cancer A-549 and human colon cancer HCT-8 cells.


Assuntos
Agaricus/química , Proteínas Fúngicas/química , Lectinas/química , Antivirais/química , Antivirais/isolamento & purificação , Antivirais/farmacologia , Carboidratos/química , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/farmacologia , Lectinas/isolamento & purificação , Lectinas/farmacologia , Metais/química , Estabilidade Proteica , Vírus do Mosaico do Tabaco/efeitos dos fármacos
11.
J Biomed Biotechnol ; 2012: 736472, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23093860

RESUMO

A novel 68 kDa laccase was purified from the mycorrhizal fungus Agaricus placomyces by utilizing a procedure that comprised three successive steps of ion exchange chromatography and gel filtration as the final step. The monomeric enzyme exhibited the N-terminal amino acid sequence of DVIGPQAQVTLANQD, which showed only a low extent of homology to sequences of other fungal laccases. The optimal temperature for A. placomyces laccase was 30°C, and optimal pH values for laccase activity towards the substrates 2,7'-azinobis[3-ethylbenzothiazolone-6-sulfonic acid] diammonium salt (ABTS) and hydroquinone were 5.2 and 6.8, respectively. The laccase displayed, at 30°C and pH 5.2, K(m) values of 0.392 mM towards hydroquinone and 0.775 mM towards ABTS. It potently suppressed proliferation of MCF 7 human breast cancer cells and Hep G2 hepatoma cells and inhibited human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) activity with an IC(50) of 1.8 µM, 1.7 µM, and 1.25 µM, respectively, signifying that it is an antipathogenic protein.


Assuntos
Agaricus/enzimologia , Transcriptase Reversa do HIV/antagonistas & inibidores , Lacase/administração & dosagem , Lacase/metabolismo , Neoplasias Experimentais/tratamento farmacológico , Inibidores da Transcriptase Reversa/química , Proliferação de Células/efeitos dos fármacos , Proteínas Fúngicas/metabolismo , Proteínas Fúngicas/farmacologia , Células Hep G2 , Humanos , Células MCF-7 , Neoplasias Experimentais/patologia
12.
Expert Opin Pharmacother ; 13(12): 1695-705, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22716311

RESUMO

INTRODUCTION: Invasive fungal infection (IFI) is a serious problem due to difficulties in early diagnosis and high mortality. Different approaches are adopted for the treatment and management of IFI, including prophylactic, empiric, preemptive and directed strategies. AREAS COVERED: This paper reviews the type of pharmacotherapy used for antifungal prophylaxis in infants with extremely low birth weights, pediatric patients with cardiac disease, preterm neonates, pediatric oncology patients, adult cancer patients with neutropenia, adult patients with hematologic malignancy, hematopoietic stem-cell transplantation recipients, organ transplant recipients, HIV-infected patients, immunosuppressed patients treated with moderate or high doses of corticosteroids, and patients with invasive fusariosis, candidemia, invasive candidiasis, systemic mycoses and immunocompromised patients. EXPERT OPINION: Azole drugs are the drugs most often used in cost-effective antifungal prophylaxis of patients with conditions such as immunodeficiency and cancer, which render them highly susceptible to IFI. Fluconazole is the most outstanding example. However, there are many azoles with different pharmacological characteristics that the physician can choose from. Echinocandins have favorable characteristics that make them useful for treating Candida infections. Antibodies, or their engineered derivatives directed against cell-wall polysaccharides and glycopeptides, and some protein epitopes of Candida albicans, appear to be a promising novel approach for prophylaxis against Candida infection and deserve further in-depth investigations.


Assuntos
Antifúngicos/uso terapêutico , Micoses/prevenção & controle , Azóis/uso terapêutico , Humanos , Hospedeiro Imunocomprometido
13.
J Microbiol ; 50(1): 72-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22367940

RESUMO

A novel laccase from the edible mushroom Hericium coralloides was purified by ion exchange chromatography on diethylaminoethyl (DEAE) cellulose, carboxymethyl (CM) cellulose, and Q-Sepharose columns followed by fast protein liquid chromatography gel filtration on a Superdex 75 column. Analysis by gel filtration and SDS-PAGE indicated that the protein is a monomer in solution with a molecular mass of 65 kDa. Its N-terminal amino acid sequence was AVGDDTPQLY, which exhibits partial sequence homology to previously isolated laccases. Optimum activity was observed at pH 2.2 and at 40°C. The enzyme showed activity toward a variety of substrates, the most sensitive of which was 2,2'-azinobis [3-ethylbenzothiazolone-6-sulfonic acid] diammonium salt (ABTS). The degradation activity toward substrates was ABTS > N,N-dimethyl-1,4-phenylenediamine > catechol > 2-methylcatechol > pyrogallol. The laccase did not exert any antiproliferative activity against Hep G2 or MCF 7 tumor cell lines at a concentration of 60 µM, unlike some previously reported mushroom proteins, but showed significant activity toward human immunodeficiency virus-1 (HIV-1) reverse transcriptase with an IC(50) of 0.06 µM.


Assuntos
Basidiomycota/enzimologia , Lacase/isolamento & purificação , Lacase/metabolismo , Cromatografia em Gel , Cromatografia por Troca Iônica , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Transcriptase Reversa do HIV/antagonistas & inibidores , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Lacase/química , Peso Molecular , Inibidores da Transcriptase Reversa/química , Inibidores da Transcriptase Reversa/isolamento & purificação , Inibidores da Transcriptase Reversa/metabolismo , Análise de Sequência de Proteína , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Temperatura
14.
J Microbiol ; 49(5): 803-8, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22068498

RESUMO

A 20-kDa ribonuclease (RNase) was purified from fresh fruiting bodies of cultured Schizophyllum commune mushrooms. The RNase was not adsorbed on Affi-gel blue gel but adsorbed on DEAE-cellulose and CM-cellulose. It exhibited maximal RNase activity at pH 6.0 and 70°C. It demonstrated the highest ribonucleolytic activity toward poly (U) (379.5 µ/mg), the second highest activity toward poly (C) (244.7 µ/mg), less activity toward poly (A) (167.4 µ/mg), and much weaker activity toward poly (G) (114.5 µ/mg). The RNase inhibited HIV-1 reverse transcriptase with an IC(50) of 65 µM. No effect on [(3)H-methyl]-thymidine uptake by lymphoma MBL2 cells and leukemia L1210 cells was observed at 100 µM concentration of the RNase. A comparison of RNases from S. commune and Volvariella volvacea revealed that they demonstrated some similarities in N-terminal amino acid sequence, optimum pH and polyhomoribonucleotide specificity. However, some differences in chromatographic behavior and molecular mass were observed.


Assuntos
Transcriptase Reversa do HIV/antagonistas & inibidores , Ribonucleases/isolamento & purificação , Ribonucleases/metabolismo , Schizophyllum/enzimologia , Linhagem Celular Tumoral , Estabilidade Enzimática , Carpóforos/enzimologia , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Peso Molecular , Poli A/metabolismo , Poli C/metabolismo , Poli G/metabolismo , Poli U/metabolismo , Ribonucleases/química , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Temperatura
15.
Appl Microbiol Biotechnol ; 90(1): 59-68, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21336922

RESUMO

This review covers the biosynthesis of glyceollin and its biological activities including antiproliferative/antitumor action (toward B16 melanoma cells, LNCaP prostate cancer cells, and BG-1 ovarian cancer cells), anti-estrogenic action (through estrogen receptors α- and ß-), antibacterial action (toward Erwinia carotovora, Escherichia coli, Bradyrhizobium japonicum, Sinorhizobium fredii ), antinematode activity, and antifungal activity (toward Fusarium solani, Phakospora pachyrhizi, Diaporthe phaseolorum, Macrophomina phaseolina, Sclerotina sclerotiorum, Phytophthora sojae, Cercospora sojina, Phialophora gregata, and Rhizoctonia solani). Other activities include insulinotropic action and attenuation of vascular contractions in rat aorta.


Assuntos
Anti-Infecciosos/farmacologia , Antineoplásicos/farmacologia , Glycine max/química , Pterocarpanos/farmacologia , Sesquiterpenos/farmacologia , Animais , Anti-Infecciosos/metabolismo , Antineoplásicos/metabolismo , Tratamento Farmacológico , Humanos , Pterocarpanos/biossíntese , Sesquiterpenos/metabolismo , Glycine max/metabolismo , Fitoalexinas
16.
Peptides ; 27(9): 2075-81, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16687191

RESUMO

A peptide, with a molecular mass of 7458 Da, was purified from the seeds of white cloud beans (Phaseolus vulgaris cv. 'white cloud bean'). This peptide was isolated using a simple protocol consisting of affinity chromatography on Affi-gel blue gel and gel filtration on Superdex 75. The peptide had both antifungal and antibacterial activities. It reduced the activity of HIV-1 reverse transcriptase and it also inhibited translation in a cell-free rabbit reticulocyte lysate system. Its antifungal activity was retained after incubation with trypsin but was reduced when the ambient ionic strength was raised. The peptide elicited a mitogenic response from mouse splenocytes but did not stimulate nitric oxide production in mouse macrophages.


Assuntos
Defensinas/farmacologia , Mitógenos/farmacologia , Phaseolus/química , Sequência de Aminoácidos , Animais , Sequência de Bases , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Cromatografia de Afinidade , Defensinas/química , Defensinas/isolamento & purificação , Feminino , Transcriptase Reversa do HIV/metabolismo , Humanos , Macrófagos Peritoneais/citologia , Macrófagos Peritoneais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mitógenos/química , Mitógenos/isolamento & purificação , Dados de Sequência Molecular , Óxido Nítrico/biossíntese , Phaseolus/citologia , Coelhos , Baço/citologia , Baço/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA