Activity of Quinones on Colletotrichum Species Meazza, Giovanni; Dayan, Franck E; Wedge, David E
Journal of agricultural and food chemistry,
06/2003, Letnik:
51, Številka:
13
Journal Article
Recenzirano
The antifungal activity of 1,4-naphthoquinones, 1,2-naphthoquinones, 1,4-benzoquinones, and anthraquinones from our natural products collection was tested by direct bioautography to identify natural ...products with potential use in agricultural fungal pathogen control. Quinones demonstrated good to moderate antifungal activity against Colletotrichum spp. Colletotrichum fragariae was the most sensitive species to quinone-based chemistry, Colletotrichum gloeosporioides had intermediate sensitivity, while Colletotrichum acutatum was the species least sensitive to these compounds. Keywords: Fungicide; natural products; triketone; naphthoquinone; benzoquinone; antifungal activity
The inhibitory activity of 34 natural products of various structural classes on hydroxyphenylpyruvate dioxygenase (HPPD), the target site for triketone herbicides, and the mode of interaction of ...selected natural products were investigated. Recombinant HPPD from arabidopsis is sensitive to several classes of natural compounds including, in decreasing order of sensitivity, triketones, benzoquinones, naphthoquinones and anthraquinones. The triketone natural products acted as competitive tight-binding inhibitors, whereas the benzoquinones and naphthoquinones did not appear to bind tightly to HPPD. While these natural products may not have optimal structural features required for in vivo herbicidal activity, the differences in their kinetic behavior suggest that novel classes of HPPD inhibitors may be developed based on their structural backbones.
Hydroxyphenylpyruvate dioxygenase is a target site for triketone herbicides. The inhibitory activity of 34 natural products of various structural classes on HPPD and the mode of interaction of selected natural products were investigated.
The lichen secondary metabolite usnic acid exists as a (−) and a (+) enantiomer, indicating a α or β projection of the methyl group at position 9b, respectively. (−)-Usnic caused a dose-dependent ...bleaching of the cotyledonary tissues associated with a decrease of both chlorophylls and carotenoids in treated plants whereas no bleaching was observed with the (+) enantiomer. (−)-Usnic acid inhibited protophorphyrinogen oxidase activity (
I
50=3 μM), but did not lead to protoporphyrin IX accumulation. Bleaching appears to be caused by irreversible inhibition of the enzyme 4-hydroxyphenylpyruvate dioxygenase by (−)-usnic acid (apparent IC
50=50 nM).
IR 5790, an arylthiadiazolone herbicide structurally related to oxadiargyl and oxadiazon, was synthesized. The herbicidal activity and mode of action of IR 5790 were investigated. This herbicide has ...broad-spectrum pre-emergence activity against both dicotyledonous and monocotyledonous weeds. The phenotypic responses of susceptible plants, such as interruption of growth and light-dependent development of necrotic areas on the foliage, are consistent with those observed with protoporphyrinogen oxidase-inhibiting herbicides. Tissues exposed to IR 5790 in darkness accumulated protoporphyrin IX, which led to a photodynamic loss of membrane integrity upon exposure to light. Consistent with these physiological symptoms, IR 5790 strongly inhibited protoporphyrinogen oxidase, with an I 50 value of 3 nM. The presence of a sulfur atom did not significantly alter the molecular properties of the thiadiazolone ring, relative to the oxadiazolone ring of oxadiargyl, which explains why IR 5790 has the same mode of action as this herbicide. Keywords: Herbicide; thiadiazolone; cellular leakage; protoporphyrinogen oxidase; protoporphyrin; Protox; peroxidizing herbicides; computer modeling
Triaryl-
β-trifluoromethyl thiophenes are synthesized from 1,3-dithiolium-4-olates and various substituted 1-aryl-3,3,3-trifluoro-1-propynes. The spectroscopic characteristics of the products and the ...regioselectivity of the reaction are discussed.
Hemophagocytic syndrome (HPS) is a severe hyperinflammatory disease, whose diagnosis is based on the HLH-2004 criteria. In secondary forms of HLH (sHLH), the primary goal is treating the triggering ...factors such as COVID-19 (Coronavirus disease 2019). The link between the cytokine storm related to COVID-19 and development of sHLH has already been reported since the onset of pandemic, but little is known about clinical manifestations of HLH which develop after the patient's recovery from mild symptomatic or asymptomatic Sars-CoV-2 infection. Our report suggests that HLH-like syndrome might be secondary to Sars-CoV-2 infection, even if the patient utterly recovered from the mildly symptomatic viral infection. In addition, we underline the treatment with low dose ruxolitinib plus etoposide as a potential choice for Sars-CoV-2 infection related HLH.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Introduction
Surgical resection of pulmonary metastases has been associated with increased survival at 5 years for osteosarcoma, but limited information is available on long-term outcome, role of ...repeated metastasectomies, and surgical sequelae in a pediatric population. We analyzed a consecutive series of children, adolescents, and young adults (AYA) treated by repeated lung metastasectomies during a period >40 years to estimate the clinical benefit and potential cure rate of salvage surgery.
Methods
All patients who underwent lung metastasectomy for osteosarcoma at the IRCCS Istituto Ortopedico Rizzoli of Bologna, University of Modena, and IRCCS Istituto Nazionale Tumori of Milan from May 1973 to January 2014 were included. Overall survival (OS) at 20 years from the first metastasectomy was calculated.
Results
A total of 463 consecutive children and AYA were analyzed. Median age was 15.9 years (range 0.2–23.2 years) and median follow-up 18.6 years. The 5- and 20-year OS were 34.0% and 29.7% (95% CI 25.5–34.0%). Among the 138 (29.8%) alive patients, 42 (30.4%) had disease recurrence cured by repeated metastasectomies. Disease-free interval from primary tumor, number of metastases, and complete resection were the most relevant survival predictors at multivariable model analysis.
Discussion
The extended follow-up of this consecutive series shows that repeated lung metastasectomy can achieve a permanent cure when offered to properly selected patients with metastases from osteosarcoma.
NK and DC reciprocal interactions have only recently been investigated. In this study, we focused on the interplay between NK cells and DC in two models of bacterial infection. Immature ...monocyte‐derived DC were cultured in the presence of live Escherichia coli or bacillus Calmette–Guérin. Upon exposure to either extracellular or intracellular bacteria, DC underwent maturation as assessed by the increased levels of expression of CD80, CD86, and HLA molecules and the de novo expression of CD83 and CCR7. Significant amounts of TNF‐α and IL‐12 were released by DCupon infection, whereas IL‐2 and IL‐15 were barely detectable in culture supernatants. Both infected and uninfected DC were capable of inducing in fresh autologous NK cells the expression of CD69 and HLA‐DR and of inducing cell proliferation. Remarkably, however, infected DC were much stronger inducers of NK cell activation and proliferation than uninfected DC. Thus, after just 24 h of NK/DC coculture, only those NK cells that had been exposed to bacteria‐infected DC had acquired the ability to lyse autologous immature DC. In addition, infected DC were more resistant to NK‐mediated lysis as a consequence of the up‐regulation of HLA class I molecule expression on their surface. This study suggests a regulatory circuit involving NK cells and DC in which DC‐induced NK cell activationis effectively enhanced by the presence of pathogens. Activated NK cells, by limiting the supply of immature DC, may then exert a control on subsequent innate and adaptive immune responses.
Background The use of computed tomography (CT) for coronavirus disease 2019 (COVID-19) diagnosis in an area of northern Italy with a high incidence of severe acute respiratory syndrome coronavirus 2 ...(SARS-CoV-2) infection may have identified more patients with this disease than RT-PCR in the very early onset of the COVID-19 pandemic. Methods We retrospectively reviewed 148 chest CT scans of oncological patients who were referred to the Radiological Unit of Policlinico S. Marco from 1 February 2020 to 30 April 2020, during the COVID-19 outbreak in Bergamo area. In parallel, we analyzed RT-PCR tests of these 148 patients. Results Among 32 patients with a diagnosis of COVID-19, 17 patients were asymptomatic or had mild symptoms (53.1%), while 15 developed severe disease (46.8%). The incidence of SARS-CoV-2 infection was 22.9%, the mortality rate was 18.8%. We did not find any correlation between disease severity and age, sex, smoking, or cardiovascular comorbidities. Remarkably, patients who were on treatment for cancer developed a milder disease than patients who were not on treatment. Conclusions The acceptance of CT-defined diagnoses in COVID-19 high-incidence areas like Bergamo region highlighted a larger oncological population affected by COVID-19 than RT-PCR, in particular, asymptomatic and mildly symptomatic patients, because only symptomatic patients underwent nasopharyngeal swabbing at the onset of the COVID-19 pandemic. We observed that patients actively treated for their cancer had a milder disease, in agreement with previous studies that suggested a protective role of immunosuppression. Admittedly, the sample of patients in our study was heterogeneous regarding the oncological disease, their prognosis, and the type of treatment; therefore, other studies are needed to confirm our data.
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