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1.
Nano Lett ; 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38968171

RESUMO

Oxygen-mediated triplet-triplet annihilation upconversion (TTA-UC) quenching limits the application of such organic upconversion materials. Here, we report that the photooxidation of organic amines is an effective and versatile strategy to suppress oxygen-mediated upconversion quenching in both organic solvents and aqueous solutions. The strategy is based on the dual role of organic amines in photooxidation, i.e., as singlet oxygen scavengers and electron donors. Under photoexcitation, the photosensitizer sensitizes oxygen to produce singlet oxygen for the oxidation of alkylamine, reducing the oxygen concentration. However, photoinduced electron transfer among photosensitizers, organic amines, and oxygen leads to the production of superoxide anions that suppress TTA-UC. To observe oxygen-tolerating TTA-UC, we find that alkyl secondary amines can balance the production of singlet oxygen and superoxide anions. We then utilize polyethyleneimine (PEI) to synthesize amphiphilic polymers to encapsulate TTA-UC pairs for the formation of water-dispersible, ultrasmall, and multicolor-emitting TTA-UC nanoparticles.

2.
Heliyon ; 10(10): e30967, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38778971

RESUMO

Chronic obstructive pulmonary disease (COPD) and other respiratory diseases frequently present with airway mucus hypersecretion, which not only affects the patient's quality of life but also poses a constant threat to their life expectancy. Ubiquitin-specific protease 7 (USP7), a deubiquitinating enzyme, affects cell differentiation, tissue growth, and disease development. However, its role in airway mucus hypersecretion induced by COPD remains elusive. In this study, USP7 expression was significantly upregulated in airway epithelial samples from patients with COPD, and USP7 was also overexpressed in mouse lung and human airway epithelial cells in models of airway mucus hypersecretion. Inhibition of USP7 reduced the expression of nuclear factor kappa B (NF-κB), phosphorylated-NF-κB (p-NF-κB), and phosphonated inhibitor of nuclear factor kappa B (p-IκBα), and alleviated the airway mucus hypersecretion in vivo and in vitro. Further research revealed that USP7 stimulated airway mucus hypersecretion through the activation of NF-κB nuclear translocation. In addition, the expression of mucin 5AC (MUC5AC) was suppressed by the NF-κB inhibitor erdosteine. These findings suggest that USP7 stimulates the NF-κB signaling pathway, which promotes airway mucus hypersecretion. This study identifies one of the mechanisms regulating airway mucus secretion and provides a new potential target for its prevention and treatment.

3.
J Am Chem Soc ; 146(15): 10785-10797, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38573588

RESUMO

The anti-Stokes shift represents the capacity of photon upconversion to convert low-energy photons to high-energy photons. Although triplet exciton-mediated photon upconversion presents outstanding performance in solar energy harvesting, photoredox catalysis, stereoscopic 3D printing, and disease therapeutics, the interfacial multistep triplet exciton transfer leads to exciton energy loss to suppress the anti-Stokes shift. Here, we report near infrared-II (NIR-II) excitable triplet exciton-mediated photon upconversion using a hybrid photosensitizer consisting of lead sulfide quantum dots (PbS QDs) and new surface ligands of thiophene-substituted diketopyrrolopyrrole (Th-DPP). Under 1064 nm excitation, this photon upconversion revealed a record-corrected upconversion efficiency of 0.37% (normalized to 100%), with the anti-Stokes shift (1.07 eV) approaching the theoretical limit (1.17 eV). The observation of this unexpected result is due to our discovery of the presence of a weak interaction between the sulfur atom on Th-DPP and Pb2+ on the PbS QDs surface, facilitating electronic coupling between PbS QDs and Th-DPP, such that the realization of triplet exciton transfer efficiency is close to 100% even when the energy gap is as small as 0.04 eV. With this premise, this photon upconversion as a photocatalyst enables the production of standing organic gel via photopolymerization under 1064 nm illumination, displaying NIR-II photon-driven photoredox catalysis. This research not only establishes the foundation for enhancing the performance of NIR-II excitable photonic upconversion but also promotes its development in photonics and photoredox catalysis.

4.
Molecules ; 28(17)2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37687209

RESUMO

The culinary medicinal mushroom Hericium erinaceus holds significant global esteem and has garnered heightened interest within increasingly ageing societies due to its pronounced neuroprotective and anti-neuroinflammatory properties. Within this study, two novel diterpenes, 16-carboxy-13-epi-neoverrucosane (1) and Erinacine L (2); three known xylosyl cyathane diterpenoids, Erinacine A (3), Erinacine C (4), and Erinacine F (5); and four lanostane-type triterpenoids, and three cyclic dipeptides (10-12), in addition to orcinol (13), were isolated from the rice-based cultivation medium of H. erinaceus. Their structures were determined by NMR, HR-ESI-MS, ECD, and calculated NMR. Compound 1 marks a pioneering discovery as the first verrucosane diterpene originating from basidiomycetes, amplifying the scope of fungal natural product chemistry, and the intricate stereochemistry of Compound 5 has been comprehensively assessed for the first time. Compounds 2-5 not only showed encouraging neurotrophic activity in rat adrenal pheochromocytoma PC-12 cells, but also significantly inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO) production in BV2 microglia cell cultures with IC50 values as low as 5.82 ± 0.18 µM. To elucidate the mechanistic underpinnings of these bioactivities, molecular docking simulation was used to analyze and support the interaction of 1 and 2 with inducible NO synthase (iNOS), respectively. In particular, compound 2, a cyathane-xyloside containing an unconventional hemiacetal moiety, is a compelling candidate for the prevention of neurodegenerative diseases. In summation, this investigation contributes substantively to the panorama of fungal diterpene structural diversity, concurrently furnishing additional empirical substantiation for the role of cyathane diterpenes in the amelioration of neurodegenerative afflictions.


Assuntos
Agaricales , Diterpenos , Animais , Ratos , Simulação de Acoplamento Molecular , Diterpenos/farmacologia
5.
World J Gastroenterol ; 29(34): 5038-5053, 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-37753370

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is a common clinical condition with a poor prognosis and few effective treatment options. Potent anticancer agents for treating HCC must be identified. Epigenetics plays an essential role in HCC tumorigenesis. Suberoylanilide hydroxamic acid (SAHA), the most common histone deacetylase inhibitor agent, triggers many forms of cell death in HCC. However, the underlying mechanism of action remains unclear. Family with sequence similarity 134 member B (FAM134B)-induced reticulophagy, a selective autophagic pathway, participates in the decision of cell fate and exhibits anticancer activity. This study focused on the relationship between FAM134B-induced reticulophagy and SAHA-mediated cell death. AIM: To elucidate potential roles and underlying molecular mechanisms of reticulophagy in SAHA-induced HCC cell death. METHODS: The viability, apoptosis, cell cycle, migration, and invasion of SAHA-treated Huh7 and MHCC97L cells were measured. Proteins related to the reticulophagy pathway, mitochondria-endoplasmic reticulum (ER) contact sites, intrinsic mitochondrial apoptosis, and histone acetylation were quantified using western blotting. ER and lysosome colocalization, and mitochondrial Ca2+ levels were characterized via confocal microscopy. The level of cell death was evaluated through Hoechst 33342 staining and propidium iodide colocalization. Chromatin immunoprecipitation was used to verify histone H4 lysine-16 acetylation in the FAM134B promoter region. RESULTS: After SAHA treatment, the proliferation of Huh7 and MHCC97L cells was significantly inhibited, and the migration and invasion abilities were greatly blocked in vitro. This promoted apoptosis and caused G1 phase cells to increase in a concentration-dependent manner. Following treatment with SAHA, ER-phagy was activated, thereby triggering autophagy-mediated cell death of HCC cells in vitro. Western blotting and chromatin immunoprecipitation assays confirmed that SAHA regulated FAM134B expression by enhancing the histone H4 lysine-16 acetylation in the FAM134B promoter region. Further, SAHA disturbed the Ca2+ homeostasis and upregulated the level of autocrine motility factor receptor and proteins related to mitochondria-endoplasmic reticulum contact sites in HCC cells. Additionally, SAHA decreased the mitochondrial membrane potential levels, thereby accelerating the activation of the reticulophagy-mediated mitochondrial apoptosis pathway and promoting HCC cell death in vitro. CONCLUSION: SAHA stimulates FAM134B-mediated ER-phagy to synergistically enhance the mitochondrial apoptotic pathway, thereby enhancing HCC cell death.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Vorinostat/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Histonas , Lisina , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Morte Celular , Autofagia
6.
Angew Chem Int Ed Engl ; 62(11): e202218341, 2023 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-36634030

RESUMO

Metal-free long-wavelength light-driven prodrug photoactivation is highly desirable for applications such as neuromodulation, drug delivery, and cancer therapy. Herein, via triplet fusion, we report on the far-red light-driven photo-release of an anti-cancer drug by coupling the boron-dipyrromethene (BODIPY)-based photosensitizer with a photocleavable perylene-based anti-cancer drug. Notably, this metal-free triplet fusion photolysis (TFP) strategy can be further advanced by incorporating an additional functional dopant, i.e. an immunotherapy medicine inhibiting the indoleamine 2,3-dioxygenase (IDO), with the far-red responsive triplet fusion pair in an air-stable nanoparticle. With this IDO inhibitor-assisted TFP system we observed efficient inhibition of primary and distant tumors in a mouse model at record-low excitation power, compared to other photo-assisted immunotherapy approaches. This metal-free TFP strategy will spur advancement in photonics and biophotonics fields.


Assuntos
Antineoplásicos , Inibidores de Checkpoint Imunológico , Animais , Camundongos , Fotólise , Luz , Imunoterapia , Indolamina-Pirrol 2,3,-Dioxigenase
7.
World J Gastroenterol ; 28(23): 2569-2581, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35949353

RESUMO

BACKGROUND: Endoplasmic reticulum (ER) stress-related hepatocyte apoptosis is responsible for multiple hepatic diseases. Previous studies have revealed that endoplasmic reticulophagy (ER-phagy) promotes the selective clearance of damaged ER fragments during ER stress, playing a crucial role in maintaining ER homeostasis and inhibiting apoptosis. Family with sequence similarity 134 member B (FAM134B) is a receptor involved in ER-phagy that can form a complex with calnexin (CNX) and microtubule-associated protein 1 light chain 3 (LC3). The complex can mediate the selective isolation of ER fragments to attenuate hepatocyte apoptosis. However, the precise regulatory mechanisms remain unclear. AIM: To elucidate the effect of FAM134B-mediated ER-phagy on ER stress-induced apoptosis in buffalo rat liver 3A (BRL-3A) rat hepatocytes and the potential regulatory mechanisms. METHODS: ER stress-related hepatocyte apoptosis was induced using dithiothreitol (DTT). Proteins related to ER stress and autophagy were measured with western blotting. Protein complex interactions with FAM134B were isolated by co-immunoprecipitation. ER-phagy was evaluated in immunofluorescence experiments. Cell cycle distribution and apoptosis were measured by flow cytometry. Mitochondrial Ca2+ levels were evaluated by the co-localization of intracellular Ca2+-tracker and Mito-tracker. The small interfering RNA against FAM134B was used to knockdown FAM134B in BRL-3A cells. RESULTS: ER stress-related and autophagy-related proteins in BRL-3A cells were elevated by both short and long-term DTT treatment. Furthermore, co-immunoprecipitation confirmed an interaction between FAM134B, CNX, FAM134B, and LC3 in BRL-3A cells. Immunofluorescence assays revealed that autolysosomes significantly decreased following short-term DTT treatment, but increased after long-term treatment. Mitochondrial Ca2+ levels and apoptotic rates were dramatically elevated, and more cells were arrested in the G1 stage after short-term DTT treatment; however, these decreased 48 h later. Moreover, FAM134B downregulation accelerated mitochondrial apoptotic pathway activation and aggravated hepatocyte apoptosis under ER stress. CONCLUSION: FAM134B-mediated ER-phagy attenuates hepatocyte apoptosis by suppressing the mitochondrial apoptotic pathway. Our findings provide new evidence highlighting the importance of FAM134B-mediated ER-phagy in attenuating hepatocyte apoptosis.


Assuntos
Autofagia , Retículo Endoplasmático , Animais , Apoptose , Autofagia/fisiologia , Ditiotreitol/farmacologia , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático , Hepatócitos , Ratos
9.
Front Pharmacol ; 12: 518406, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33994999

RESUMO

Marsdeniae tenacissimae Caulis is a traditional Chinese medicine, named Tongguanteng (TGT), that is often used for the adjuvant treatment of cancer. In our previous study, we reported that an ethyl acetate extract of TGT had inhibitory effects against adenocarcinoma A549 cells growth. To identify the components of TGT with anti-tumor activity and to elucidate their underlying mechanisms of action, we developed a technique for isolating compounds, which was then followed by cytotoxicity screening, network pharmacology analysis, and cellular and molecular experiments. We isolated a total of 19 compounds from a TGT ethyl acetate extract. Two novel steroidal saponins were assessed using an ultra-performance liquid chromatography-photodiode array coupled with quadrupole time-of-flight mass (UPLC-ESI-Q/TOF-MS). Then, we screened these constituents for anti-cancer activity against non-small cell lung cancer (NSCLC) in vitro and obtained six target compounds. Furthermore, a compound-target-pathway network of these six bioactive ingredients was constructed to elucidate the potential pathways that controlled anticancer effects. Approximately 205 putative targets that were associated with TGT, as well as 270 putative targets that were related to NSCLC, were obtained from online databases and target prediction software. Protein-protein interaction networks for drugs as well as disease putative targets were generated, and 18 candidate targets were detected based on topological features. In addition, pathway enrichment analysis was performed to identify related pathways, including PI3K/AKT, VEGF, and EGFR tyrosine kinase inhibitor resistance, which are all related to metabolic processes and intrinsic apoptotic pathways involving reactive oxygen species (ROS). Then, various cellular experiments were conducted to validate drug-target mechanisms that had been predicted using network pharmacology analysis. The experimental results showed the four C21 steroidal saponins could upregulate Bax and downregulate Bcl-2 expression, thereby changing the mitochondrial membrane potential, producing ROS, and releasing cytochrome C, which finally activated caspase-3, caspase-9, and caspase-8, all of which induced apoptosis in A549 cells. In addition, these components also downregulated the expression of MMP-2 and MMP-9 proteins, further weakening their degradation of extracellular matrix components and type IV collagen, and inhibiting the migration and invasion of A549 cells. Our study elucidated the chemical composition and underlying anti-tumor mechanism of TGT, which may be utilized in the treatment of lung cancer.

10.
Eur J Pharmacol ; 851: 1-12, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30768982

RESUMO

Cisplatin is a widely used chemotherapeutic drug that often causes acute kidney injury (AKI) in cancer patients. The contribution of miRNAs to the cisplatin-induced renal tubular epithelial cell injury remains largely unknown. Here we performed an integrative network analysis of miRNA and mRNA expression profiles to shed light into the underlying mechanism of cisplatin-induced renal tubular epithelial cell injury. Microarray analysis identified 47 differentially expressed miRNAs, among them 26 were upregulated and 21 were downregulated. Moreover, integrating dysregulated miRNAs target prediction and altered mRNA expression enabled us to identify 1181 putative target genes for further bioinformatics analysis. Gene ontology (GO) analysis revealed that the putative target genes were involved in apoptosis process and regulation of transcription. Pathway analysis indicated that the top upregulated pathways included MAPK and p53 signaling pathway, while the top downregulated pathways were PI3K-Akt and Wnt signaling pathway. Further network analysis showed that MAPK signaling pathway and apoptosis with the highest degree were identified as core pathways, hsa-miR-9-3p and hsa-miR-371b-5p as the most critical miRNAs, and CASK, ASH1L, CDK6 etc. as hub target genes. In addition, the expression level change of selected five microRNAs (hsa-miR-4299, hsa-miR-297, hsa-miR-3135b, hsa-miR-9-3p, and hsa-miR-371b-5p) and two mRNAs( CASK and CDK6) were validated in cisplatin-induced HK-2 cells. Furthermore, a similar trend of expression level change was observed in NRK-52E cells by cisplatin treatment. Overall, our results provide the molecular basis and potential targets for the treatment of cisplatin-induced renal tubular cell injury.


Assuntos
Cisplatino/farmacologia , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Redes Reguladoras de Genes/efeitos dos fármacos , Túbulos Renais/citologia , MicroRNAs/genética , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , RNA Mensageiro/genética , Transcriptoma/efeitos dos fármacos
11.
Oncotarget ; 8(55): 93516-93529, 2017 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-29212169

RESUMO

CCCTC-binding factor (CTCF) is an important epigenetic regulator implicated in multiple cellular processes, including growth, proliferation, differentiation, and apoptosis. Although CTCF deletion or mutation has been associated with human breast cancer, the role of CTCF in breast cancer is questionable. We investigated the biological functions of CTCF in breast cancer and the underlying mechanism. The results showed that CTCF expression in human breast cancer cells and tissues was significantly lower than that in normal breast cells and tissues. In addition, CTCF expression correlated significantly with cancer stage (P = 0.043) and pathological differentiation (P = 0.029). Furthermore, CTCF overexpression resulted in the inhibition of proliferation, migration, and invasion, while CTCF knockdown induced these processes in breast cancer cells. Transcriptome analysis and further experimental confirmation in MDA-MD-231 cells revealed that forced overexpression of CTCF might attenuate the DNA-binding ability of nuclear factor-kappaB (NF-κB) p65 subunit and inhibit activation of NF-κB and its target pro-oncogenes (tumor necrosis factor alpha-induced protein 3 [TNFAIP3]) and genes for growth-related proteins (early growth response protein 1 [EGR1] and growth arrest and DNA-damage-inducible alpha [GADD45a]). The present study provides a new insight into the tumor suppressor roles of CTCF in breast cancer development and suggests that the CTCF/NF-κB pathway is a potential target for breast cancer therapy.

12.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-838474

RESUMO

To explore the influence of the hepatocyte-specific up-regulation of hepatocyte nuclear factor 1α (HNF1α) on mouse hepatic fibrosis induced by carbon tetrachloride (CCl4). Methods Eighteen C57/B6 male mice were randomly divided into normal group, AAV8-TBG-Ctrl group and AAV8-TBG-HNF1α group, with 6 mice in each group. Mice in the AAV8-TBG-Ctrl and AAV8-TBG-HNF1α groups were intraperitoneally injected with CCl4 to establish the hepatic fibrosis mouse model, and then the mice in the AAV8-TBG-HNF1α group were injected with AAV8-TBG-HNF1α carrying HNF1α gene under the control of the thyroid-binding globulin (TBG) promoter to specifically up-regulate expression of HNF1α in hepatocytes, while the mice in the AAV8-TBG-Ctrl group were injected with control vector AAV8-TBG. The expression of HNF1α was determined by immunohistochemistry and qPCR. The pathological changes and collagen deposition of liver tissues were detected by hematoxylin-eosin (H-E) staining and sirius red staining, respectively. Immunohistochemistry method was used to detect α-smooth muscle actin (α-SMA), and the expression of fibrosis related genes (typecollagen α1 chain[COL1A1], α-SMA), epithelial related genes (E-cadherin, Plakoglobin) and mesenchymal related genes (Vimentin, Slug and Twist1) in liver tissues were analyzed by qPCR. The cell proliferation and apoptosis in fibrotic livers were detected by immunohistochemistry and TdT-mediated dUTP Nick-End Labeling (TUNEL) method, respectively. Results Compared with the normal mice, CCl4 promoted collagen deposition and the expression of α-SMA in livers, and the expression of HNF1α was significantly decreased (P0.05). Conclusion Hepatocyte-specific up-regulation of HNF1α significantly improves CCl4-induced liver fibrosis in mice.

13.
Fish Shellfish Immunol ; 43(1): 264-74, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25559445

RESUMO

Intracellular fatty acid-binding proteins (FABPs) are members of the lipid-binding protein superfamily. Aside from the main functions of FABPs in the uptake and transport of fatty acids, they are also critical in innate immunology. In this work, the full-length cDNA for a Chinese mitten crab Eriocheir sinensis FABP (Es-FABP3) was cloned with an open reading frame of 402 bp encoding a 133 amino acid polypeptide. Analysis using quantitative real-time PCR (qPCR) revealed that Es-FABP3 transcripts were widely distributed in gills, muscle, intestine, hepatopancreas, eyestalk, heart, stomach, brain, thoracic ganglia and hemocytes. After challenge with pathogen associated molecular pattern molecules (PAMPs), the relative mRNA expression levels of Es-FABP3 increased in hepatopancreas, gills and hemocytes. Moreover, the mature recombinant Es-FABP3 protein exhibited different binding activities to bacteria and fungus and inhibited the growth of different microbes. These collective results demonstrated the role of Es-FABP3 in the immunoreactions of E. sinensis to PAMPs.


Assuntos
Anti-Infecciosos/farmacologia , Proteínas de Artrópodes/genética , Braquiúros/genética , Braquiúros/imunologia , Proteínas de Ligação a Ácido Graxo/genética , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/metabolismo , Sequência de Bases , Braquiúros/metabolismo , Braquiúros/microbiologia , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/metabolismo , Proteínas de Ligação a Ácido Graxo/química , Proteínas de Ligação a Ácido Graxo/metabolismo , Bactérias Gram-Negativas/fisiologia , Bactérias Gram-Positivas/fisiologia , Dados de Sequência Molecular , Especificidade de Órgãos , Filogenia , Pichia/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência
14.
Ai Zheng ; 26(6): 643-6, 2007 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-17562273

RESUMO

BACKGROUND & OBJECTIVE: It's difficult to distinguish peripheral primitive neuroectodermal tumor (PNET) from other small round cell tumors such as Ewing's sarcoma by histological examination. This study was to analyze the CT and MRI features of peripheral PNET. METHODS: The CT and MRI records of 7 patients with pathologically proved peripheral PNET were reviewed. RESULTS: The tumors were located in the left ala nasi, right lower jaw bone, left chest wall, right chest wall, left spermatic cord, paraspinal, and lumbar vertebral canal. The tumors in soft tissue showed resembled non-calcified, ill-defined soft tissue masses with cystic or necrotic areas on CT images, with heterogeneous enhancement on contrast images. The tumors in the bone showed lytic lesions with large soft tissue masses on CT images. The tumors in the paraspinal and vertebral canal showed well-defined soft tissue masses without involving cord and cauda equine on MRI, and showed isointensity or hypointensity on T1WI and isointensity or hyperintensity on T2WI. CONCLUSIONS: The imaging features of peripheral PNET are non-specific. CT and MRI are useful in delineating the extent, finding distant metastasis, predicting respectability and monitoring treatment of peripheral PNET.


Assuntos
Neoplasias Maxilomandibulares/diagnóstico por imagem , Tumores Neuroectodérmicos Primitivos Periféricos/diagnóstico por imagem , Tumores Neuroectodérmicos Primitivos Periféricos/diagnóstico , Neoplasias da Coluna Vertebral/diagnóstico , Neoplasias Torácicas/diagnóstico por imagem , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Neoplasias dos Genitais Masculinos/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Recidiva Local de Neoplasia , Tumores Neuroectodérmicos Primitivos Periféricos/patologia , Estudos Retrospectivos , Cordão Espermático/diagnóstico por imagem , Canal Medular , Neoplasias Torácicas/patologia , Tomografia Computadorizada por Raios X , Adulto Jovem
15.
Microbiology (Reading) ; 145 ( Pt 12): 3557-3564, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10627053

RESUMO

A unique chlorinated macrocyclic lactone, termed oocydin A, was isolated from a strain of Serratia marcescens growing as an epiphyte on Rhyncholacis pedicillata, an aquatic plant native to the Carrao river of the Venezuelan-Guyanan region of South America. The lactone has a molecular mass of 470 Da, and contains one atom of chlorine, a carboxyl group and a tetrahydrofuran ring internal to a larger macrocyclic ring. MICs of approximately 0.03 microg ml(-1) were noted for oocydin A against such phytopathogenic oomycetes as Pythium ultimum, Phytophthora parasitica, Phytophthora cinnamomi and Phytophthora citrophora. With regard to the true fungi, oocydin A had either minimal or no effect against certain Fungi Imperfecti (including several pathogens of humans), two ascomycetes and a basidiomycete. Oocydin A may have potential as an antimycotic in agricultural applications and especially for crop protection.


Assuntos
Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Lactonas/isolamento & purificação , Lactonas/farmacologia , Oomicetos/efeitos dos fármacos , Serratia marcescens/metabolismo , Antifúngicos/química , Antifúngicos/metabolismo , Cromatografia Líquida de Alta Pressão , Meios de Cultura , Ecossistema , Água Doce , Lactonas/química , Lactonas/metabolismo , Espectrometria de Massas/métodos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Oomicetos/crescimento & desenvolvimento , Phytophthora/efeitos dos fármacos , Phytophthora/crescimento & desenvolvimento , Plantas/microbiologia , Serratia marcescens/crescimento & desenvolvimento
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