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1.
Biodegradation ; 22(1): 129-41, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20602151

RESUMO

The sporadic growth of Cynodon dactylon was observed to occur directly on the surface of hard coal in dumps of the Witbank coal mining area of South Africa with the surface coal being broken down into a humic-like particulate material. Microorganism analysis of plants and rhizosphere material from the dumps revealed the presence of arbuscular mycorrhizal fungi and the coal solubilising fungus, Neosartorya fischeri. Studies established to replicate the dump environment revealed increased coal degradation in the form of humic acid production and an increase in small size particles as a result of Cynodon dactylon growth in association with arbuscular mycorrhizal fungi and Neosartorya fischeri. Results suggest that interactions between Cynodon dactylon, arbuscular mycorrhizal fungi, Neosartorya fischeri and other coal-degrading rhizosphere fungi could lead to the degradation of hard coal in situ and that the application of these organisms to discard dumps could be a novel method of coal dump rehabilitation.


Assuntos
Carvão Mineral/microbiologia , Cynodon/crescimento & desenvolvimento , Fungos/metabolismo , Eliminação de Resíduos/métodos , Biodegradação Ambiental , Carvão Mineral/análise , Cynodon/metabolismo , Cynodon/microbiologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Dados de Sequência Molecular , Micorrizas/classificação , Micorrizas/genética , Micorrizas/isolamento & purificação , Micorrizas/metabolismo , Filogenia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Microbiologia do Solo
2.
Dig Liver Dis ; 53(11): 1396-1403, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34373229

RESUMO

BACKGROUND: Severe thrombocytopenia in cirrhosis can preclude invasive procedures. Platelet transfusion is recommended if platelet count pre-procedure is potential alternative to platelet transfusion is thrombopoietin-receptor (TPO) agonists. AIM: Evaluate TPO-agonist efficacy and safety in cirrhotic patients with severe thrombocytopenia undergoing invasive procedures. METHODS: Randomized control trials (RCT) from electronic reference databases were searched from inception till December 2019. PRISMA guidelines were followed. Primary outcome was platelet transfusion avoidance. Secondary outcomes were weighted mean difference (WMD) in platelet count from baseline to pre-procedure and rates of major adverse events (AE). Pooled Odds Ratio (OR) were estimated using a random-effects model. RESULTS: Six RCTs with 1,229 patients were included. All studies had low risk of bias. Compared with placebo, those treated with TPO-agonists had a pooled OR of 0.12(0.08-0.17), P<0.01 for platelet transfusion avoidance, and WMD in platelet count (x10 3 /µL) of 35.6(28.6-42.7), P<0.01. Major AE did not differ between groups [Pooled OR: 0.87(0.47-1.62), P=0.66]. CONCLUSION: Compared to placebo, TPO-agonists used in cirrhotic patients with severe thrombocytopenia prior to elective invasive procedures had 88% reduced odds of requiring peri-procedural platelet transfusion and increased platelet count pre-procedure, with no difference in AE rates.


Assuntos
Cirrose Hepática/tratamento farmacológico , Receptores de Trombopoetina/uso terapêutico , Trombocitopenia/tratamento farmacológico , Procedimentos Cirúrgicos Eletivos , Humanos , Cirrose Hepática/complicações , Contagem de Plaquetas , Cuidados Pré-Operatórios/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Receptores de Trombopoetina/agonistas , Trombocitopenia/etiologia
3.
Bioresour Technol ; 99(7): 2333-9, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-17604622

RESUMO

Acid mine drainage waters are characterised by a low pH, high concentrations of heavy metals, high levels of sulphate salts and low concentrations of organic material. The biological treatment of these waters has been a subject of increasing focus as an alternative to physico-chemical treatment. The utilisation of lignocellulose as a carbon source has been restricted by the amount of reducing equivalents available within the lignocellulose matrix. This present study demonstrated that lignocellulose could be utilised as a carbon source for sulphate reduction. It was shown that the initial reduction of sulphate observed using lignocellulose as a carbon source was due to the easily extractable components. This degradation resulted in the production of sulphide ( approximately 500 mg/l), which further aided in the degradation of lignin (observed as a release of aromatic compounds), allowing greater access to cellulose (and release of reducing sugars).


Assuntos
Celulose/metabolismo , Lignina/metabolismo , Sulfetos/química , Celulose/química , Concentração de Íons de Hidrogênio , Lignina/química
4.
Biomaterials ; 155: 92-102, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29175084

RESUMO

Dendritic cells (DC) are the most potent antigen-presenting cells and are fundamental for the establishment of transplant tolerance. The Dendritic Cell-Specific Intracellular adhesion molecule-3-Grabbing Non-integrin (DC-SIGN; CD209) receptor provides a target for dendritic cell therapy. Biodegradable and high-surface area porous silicon (pSi) nanoparticles displaying anti-DC-SIGN antibodies and loaded with the immunosuppressant rapamycin (Sirolimus) serve as a fit-for-purpose platform to target and modify DC. Here, we describe the fabrication of rapamycin-loaded DC-SIGN displaying pSi nanoparticles, the uptake efficiency into DC and the extent of nanoparticle-induced modulation of phenotype and function. DC-SIGN antibody displaying pSi nanoparticles favourably targeted and were phagocytosed by monocyte-derived and myeloid DC in whole human blood in a time- and dose-dependent manner. DC preconditioning with rapamycin-loaded nanoparticles, resulted in a maturation resistant phenotype and significantly suppressed allogeneic T-cell proliferation.


Assuntos
Células Dendríticas/efeitos dos fármacos , Nanopartículas/química , Silício/química , Células Dendríticas/imunologia , Humanos , Nanomedicina , Porosidade
6.
Water Environ Res ; 78(7): 701-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16929640

RESUMO

An investigation of biodegradation of chlorinated phenol in an anaerobic/aerobic bioprocess environment was made. The reactor configuration used consisted of linked anaerobic and aerobic reactors, which served as a model for a proposed bioremediation strategy. The proposed strategy was studied in two reactors before linkage. In the anaerobic compartment, the transformation of the model contaminant, 2,4,6-trichlorophenol (2,4,6-TCP), to lesser-chlorinated metabolites was shown to occur during reductive dechlorination under sulfate-reducing conditions. The consortium was also shown to desorb and mobilize 2,4,6-TCP in soils. This was followed, in the aerobic compartment, by biodegradation of the pollutant and metabolites, 2,4-dichlorophenol, 4-chlorophenol, and phenol, by immobilized white-rot fungi. The integrated process achieved elimination of the compound by more than 99% through fungal degradation of metabolites produced in the dechlorination stage. pH correction to the anaerobic reactor was found to be necessary because acidic effluent from the fungal reactor inhibited sulfate reduction and dechlorination.


Assuntos
Bactérias Aeróbias/fisiologia , Bactérias Anaeróbias/fisiologia , Clorofenóis/toxicidade , Mutagênicos/toxicidade , Microbiologia do Solo , Poluentes do Solo/metabolismo , Purificação da Água , Basidiomycota/metabolismo , Biodegradação Ambiental , Células Imobilizadas , Poluição Ambiental , Oxirredução
7.
Biotechnol J ; 5(3): 292-303, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20084638

RESUMO

Fundamental processes involved in the microbial degradation of coal and its derivatives have been well documented. A mutualistic interaction between plant roots and certain microorganisms to aid growth of plants such as Cynodon dactylon (Bermuda grass) on hard coal dumps has recently been suggested. In the present study coal bioconversion activity of nonmycorrhizal fungi was investigated in the C. dactylon/coal rhizosphere. Fungal growth on 2% Duff-agar, gutation formation on nitric acid treated coal and submerged culture activity in nitrogen-rich and -deficient broth formed part of the screening and selection of the fungi. The selected fungal isolates were confirmed to be found in pristine C. dactylon/coal rhizosphere. To simulate bioconversion, a fungal aliquot of this rhizosphere was used as inoculum for a Perfusate fixed bed bioreactor, packed with coal. The results demonstrate an enhanced coal bioconversion facilitated by low molecular weight organics and the bioconversion of coal may be initiated by an introduction of nitrogen moieties to the coal substrate. These findings suggest a phyto-bioconversion of hard coal involving plant and microbes occurring in the rhizosphere to promote the growth of C. dactylon. An understanding of this relationship can serve as a benchmark for coal dumps rehabilitation as well as for the industrial scale bioprocessing of hard coal.


Assuntos
Reatores Biológicos/microbiologia , Carvão Mineral/microbiologia , Cynodon/microbiologia , Fungos/fisiologia , Microbiologia do Solo , Biodegradação Ambiental , Meios de Cultura , Fungos/isolamento & purificação , Modelos Biológicos , Neosartorya/genética , Neosartorya/crescimento & desenvolvimento , Neosartorya/isolamento & purificação , Neosartorya/metabolismo , Filogenia , Raízes de Plantas/microbiologia
8.
Biotechnol J ; 3(11): 1407-16, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19016511

RESUMO

Cynodon dactylon (Bermuda grass) has been observed to grow sporadically on the surface of coal dumps in the Witbank coal mining area of South Africa. Root zone investigation indicated that a number of fungal species may be actively involved in the biodegradation of hard coal, thus enabling the survival of the plant, through mutualistic interaction, in this extreme environment. In an extensive screening program of over two thousand samples, the Deuteromycete, Neosartorya fischeri, was isolated and identified. The biodegradation of coal by N. fischeri was tested in flask studies and in a perfusion fixed-bed bioreactor used to simulate the coal dump environment. The performance of N. fischeri was compared to Phanaerochaete chrysosporium and Trametes (Polyporus) versicolor, previously described in coal biodegradation studies. Fourier transform infrared spectrometry and pyrolysis gas chromatography mass spectrometry of the biodegradation product indicated oxidation of the coal surface and nitration of the condensed aromatic structures of the coal macromolecule as possible reaction mechanisms in N. fischeri coal biodegradation. This is a first report of N. fischeri-mediated coal biodegradation and, in addition to possible applications in coal biotechnology, the findings may enable development of sustainable technologies in coal mine rehabilitation.


Assuntos
Carvão Mineral/microbiologia , Neosartorya/isolamento & purificação , Neosartorya/metabolismo , Análise de Variância , Biodegradação Ambiental , Biofilmes/crescimento & desenvolvimento , Reatores Biológicos , Cynodon/crescimento & desenvolvimento , Cynodon/microbiologia , Cromatografia Gasosa-Espectrometria de Massas , Substâncias Húmicas/análise , Substâncias Húmicas/microbiologia , Neosartorya/citologia , Phanerochaete/metabolismo , Raízes de Plantas/microbiologia , Espectroscopia de Infravermelho com Transformada de Fourier , Simbiose , Trametes/metabolismo
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