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1.
BMC Microbiol ; 21(1): 155, 2021 05 27.
Article in English | MEDLINE | ID: mdl-34044780

ABSTRACT

BACKGROUND: Eucalyptus bacterial wilt caused by Ralstonia solanacearum is an important eucalyptus disease. Endophytic fungi, an important source of natural active substances, provide a new breakthrough for the control of plant diseases. RESULTS: In the present study, 80 endophytic fungal isolates were obtained from the healthy branches and fruits of Eucalyptus exserta. Fifteen distinct isolates (MK120854-MK120868) were selected for further taxonomic identification through morphological trait assessments and internal transcribed spacer (ITS) region-rRNA gene sequence analysis. Thirteen genera, namely, Phyllosticta, Penicillium, Eutypella, Purpureocillium, Talaromyces, Lophiostoma, Cladosporium, Pestalotiopsis, Chaetomium, Fusarium, Gongronella, Scedosporium and Pseudallescheria, were identified on the basis of their morphological characteristics. Members of the genus Phyllosticta were the primary isolates, with a colonization frequency (CF) of 27.5 %. Most of the fungal isolates displayed antibacterial activity. The crude extracts obtained from Lophiostoma sp. Eef-7, Pestalotiopsis sp. Eef-9 and Chaetomium sp. Eef-10 exhibited strong inhibition on the test bacteria, and Lophiostoma sp. Eef-7 was further cultured on a large scale. Three known compounds, scorpinone (1), 5-deoxybostrycoidin (2) and 4-methyl-5,6-dihydro-2 H-pyran-2-one (3), were isolated from the endophytic fungus Lophiostoma sp. Eef-7 associated with E. exserta. The structures of these compounds were elucidated by analysis of 1D and 2D NMR and HR-ESI-MS spectra and a comparison of their spectral data with published values. Compounds 1 and 2 showed weak antimicrobial activity against Ralstonia solanacearum. CONCLUSIONS: Endophytic fungi from Eucalyptus exserta may represent alternative sources of antimicrobial agents. Lophiostoma sp. Eef-7 can produce 2-azaanthraquinone derivatives and shows weak antibacterial activity against Ralstonia solanacearum.


Subject(s)
Anti-Bacterial Agents/chemistry , Endophytes/chemistry , Eucalyptus/microbiology , Fungi/chemistry , Anti-Bacterial Agents/metabolism , Anti-Bacterial Agents/pharmacology , Endophytes/classification , Endophytes/genetics , Endophytes/metabolism , Fruit/microbiology , Fungi/classification , Fungi/genetics , Fungi/metabolism , Plant Stems/microbiology , Ralstonia solanacearum/drug effects , Spectrometry, Mass, Electrospray Ionization
2.
PeerJ ; 8: e8221, 2020.
Article in English | MEDLINE | ID: mdl-31915570

ABSTRACT

A new p-terphenyl derivative 4″-deoxy-2'-methoxyterphenyllin (1), along with six known p-terphenyl derivatives (2-7), a known flavonoid derivative dechlorochlorflavonin (8) and a known fellutanine A (9), were isolated from the insect-derived strain of the fungus Aspergillus candidus Bdf-2, associated with Blaptica dubia. The structure of 1 was established by the analysis of the 1D and 2D NMR and HR-ESI-MS spectra. Compounds 1-9 were evaluated for antibacterial activities against Staphylococcus aureus ATCC29213, Escherichia coli ATCC25922 and Ralstonia solanacearum, and for antioxidant activities. Synergistic effects of compound 2 with the other compounds were also investigated. As a result, compound 6 displayed the best antibacterial activities in all single compound with MIC value of 32 µg/mL against S. aureus ATCC29213 and R. solanacearum, respectively. However, no antibacterial effect against E. coli ATCC25922 was detected from any single compound. The combination of 2 + 6 exhibited obvious synergistic effect against S. aureus ATCC29213 and the MIC value was 4 µg/mL. Compound 6 also showed the best antioxidant activity as a single compound with an IC50 value of 17.62 µg/mL. Combinations of 5 + 6, 2 + 4 + 5 and 2 + 4 + 5 + 6 displayed synergistic effect and their antioxidant activities were better than that of any single compound.

3.
Gut ; 67(10): 1757-1768, 2018 10.
Article in English | MEDLINE | ID: mdl-29691276

ABSTRACT

Non-variceal upper gastrointestinal bleeding remains an important emergency condition, leading to significant morbidity and mortality. As endoscopic therapy is the 'gold standard' of management, treatment of these patients can be considered in three stages: pre-endoscopic treatment, endoscopic haemostasis and post-endoscopic management. Since publication of the Asia-Pacific consensus on non-variceal upper gastrointestinal bleeding (NVUGIB) 7 years ago, there have been significant advancements in the clinical management of patients in all three stages. These include pre-endoscopy risk stratification scores, blood and platelet transfusion, use of proton pump inhibitors; during endoscopy new haemostasis techniques (haemostatic powder spray and over-the-scope clips); and post-endoscopy management by second-look endoscopy and medication strategies. Emerging techniques, including capsule endoscopy and Doppler endoscopic probe in assessing adequacy of endoscopic therapy, and the pre-emptive use of angiographic embolisation, are attracting new attention. An emerging problem is the increasing use of dual antiplatelet agents and direct oral anticoagulants in patients with cardiac and cerebrovascular diseases. Guidelines on the discontinuation and then resumption of these agents in patients presenting with NVUGIB are very much needed. The Asia-Pacific Working Group examined recent evidence and recommends practical management guidelines in this updated consensus statement.


Subject(s)
Embolization, Therapeutic/methods , Endoscopy, Gastrointestinal/methods , Gastrointestinal Hemorrhage , Peptic Ulcer Hemorrhage , Platelet Aggregation Inhibitors/therapeutic use , Practice Guidelines as Topic , Proton Pump Inhibitors/therapeutic use , Consensus , Gastrointestinal Hemorrhage/classification , Gastrointestinal Hemorrhage/diagnosis , Gastrointestinal Hemorrhage/therapy , Humans , Patient Selection , Peptic Ulcer Hemorrhage/diagnosis , Peptic Ulcer Hemorrhage/therapy , Recurrence , Reoperation , Risk Assessment/methods
4.
Clin Ophthalmol ; 1(1): 71-7, 2007 Mar.
Article in English | MEDLINE | ID: mdl-19668469

ABSTRACT

PURPOSE: To investigate the effect of inflammatory cytokines on the activity of the human MUC5AC promoter in vitro and in vivo. METHODS: Conjunctival epithelial cells transfected with MUC5AC-luciferase plasmids challenged with different cytokines (tumor necrosis factor-alpha [TNF-alpha], interleukin [IL]-1beta, IL-2, IL-6, and IL-8) at various concentration (1, 10, 20, 50, 100, 200, 500, 1000, and 2000 pg/mL) for 24 hours. A Helio Gene Gun system (Bio-Rad Laboratories, Hercules, CA, USA) was used to deliver MUC5AC-luciferase plasmids into rabbit conjunctivas, which were also challenged with these cytokines (1000 pg/mL) at the frequency of every six hours for 48 hours. The activity of MUC5AC-luciferase was then evaluated using the luciferase assay. RESULTS: Results of the studies demonstrated that IL-1beta and TNF-alpha upregulated the activity of MUC5AC-luciferase in cultured conjunctival cells, while IL-2, IL-6, and IL-8 had no effect. In rabbit conjunctival tissues, TNF-alpha, IL-1beta, IL-2, IL-8, and IL-6 significantly upregulated MUC5AC gene expression. CONCLUSIONS: This suggests that MUC5AC mucin gene expression is regulated by proinflammatory cytokines, which could have implications in ocular surface disorders.

5.
J Cataract Refract Surg ; 31(8): 1661-3, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16129309

ABSTRACT

We report a case of a persistent pupillary membrane (PPM) associated with a cataract managed by sequential argon-YAG laser membranectomy and phacoemulsification. A 30-year-old woman had an extensive PPM and anterior capsular opacity of the lens in the right eye. Best corrected visual acuity (BCVA) was 20/60. Argon laser photocoagulation was performed at the junction of the PPM and the iris collarette. Subsequently, a neodymium:YAG laser was used to sever the strands of the PPM. These laser procedures resulted in shrinkage of the PPM without hemorrhage in the iris or other complications. The patient had clear corneal sutureless phacoemulsification uneventfully on the next day. The BCVA improved to 20/25 3 months following the treatment. We conclude that combined sequential argon-YAG laser membranectomy and modern phacoemulsification surgery can effectively be used to treat PPM associated with cataract without bleeding of the iris or other major side effects.


Subject(s)
Iris Diseases/surgery , Iris/surgery , Laser Coagulation/methods , Phacoemulsification/methods , Adult , Cataract/etiology , Female , Humans , Iris Diseases/complications , Membranes/surgery , Pupil , Visual Acuity
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