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Functions of Essential Oils and Natural Volatiles in Plant-Insect Interactions
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
A serious problem for social bees with generalized foraging patterns (Bombus terrestris in Europe, B. impatiens in North America) is the spread of the trypanosome Crithidia bombi, an obligate gut parasite of bumble bees that is transmitted among bees through infected feces (Schmid-Hempel and Durrer, 1991). In addition to direct impacts on bee survival and reproduction, infection by C. bombi also reduces the ability of bees to learn different floral traits in association with sugar rewards (Gegear et al., 2006). One promising development is that thymol was found to inhibit the growth of C. bombi when applied in dosages comparable to their natural occurrence in T. vulgaris floral nectar (5–8 ppm), presumably by disrupting the parasite's cell and mitochondrial membranes (Palmer-Young et al., 2016). Subsequent research indicates that the prophylactic effects of nectar thymol on C. bombi are synergized when eugenol, another widespread component of floral EOs and nectars, is present, suggesting that diversified nectar meals may help bees to mitigate trypanosome infection (Palmer-Young et al., 2017b). However, strains of thymol-resistant C. bombi may evolve quickly, even when multiple EO components are used in biocontrol (Palmer-Young et al., 2017a). We are just beginning to understand how non-sugar nectar components, including but not limited to volatile EO constituents, impact the health of bees and other flower-visiting animals (Richardson et al., 2015).
Cultivation of Entamoeba Histolytica
Published in Roberto R. Kretschmer, Amebiasis: Infection and Disease by Entamoeba histolytica, 2020
Pan showed that serial subculture of the amebas could be obtained with several other trypanosomatids, including T. lewisi, Leishmania brasiliensis, L. donovani, L. enrettii, and Endotrypanum schaudinni.40 Diamond used amebas grown monoxenically with a trypanosomatid (Crithidia sp.) isolated from the cog-wheel bug (Arilus cristatus) to initiate the first axenic cultures of E. histolytica,6 and devised improved media for monoxenic cultivation of Entamoeba with the crithidium and T. cruzi.41
Unexplained Fever Associated With Hypersensitivity and Auto-Immune Diseases
Published in Benedict Isaac, Serge Kernbaum, Michael Burke, Unexplained Fever, 2019
Anti-DNA antibodies — Two techniques are usually performed. The radioimmuno-logical Farr test (which uses immunoglobulin (IgG) precipitation by ammonium sulfate) is a sensitive detector of all antibodies capable of binding to DNA, independent of their biological properties. It is positive in 80 to 98% of SLE cases, in 0 to 6% of patients with rheumatoid arthritis and in 0 to 2% of normal subjects.2 The second technique used in the routine clinical detection is an immunofluorescent method detecting antibodies to double-stranded DNA employing the kinetoplast of the flagellate Crithidia luciliae as a substrate. It allows determination of the antibodies according to their nature (IgG, IgM, IgA) and their complement fixing ability (IgGl, IgG3); it may give false-positive results; it is positive in up to 96% of SLE sera.2 Then the diagnosis of SLE relies on the association of evocative clinical lesions with immune abnormalities.
Mechanistic and biological characterisation of novel N 5-substituted paullones targeting the biosynthesis of trypanothione in Leishmania
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Andrea Medeiros, Diego Benítez, Ricarda S. Korn, Vinicius C. Ferreira, Exequiel Barrera, Federico Carrión, Otto Pritsch, Sergio Pantano, Conrad Kunick, Camila I. de Oliveira, Oliver C. F. Orban, Marcelo A. Comini
The kinetic and thermodynamic studies strongly suggest that the binding site of MOL2008 and 20, at least partially, overlaps with that of SP and GSP. GspS is an enzyme capable to catalyse the formation of GSP but not of T(SH)2 due to steric effects that preclude binding of GSP to the enzyme’s active site36. Thus, we reasoned that if occupation of the GSP-binding site by N5-substituted paullones is relevant for TryS inhibition, then GspS should not be inhibited by these compounds. Confirming our hypothesis, GspS from the Kinetoplastid Crithidia fasciculata proved refractory to MOL2008, which caused a minor inhibition (20%) of the enzyme at the highest concentration tested of 300 µM (see Supplementary Information for details about protein preparation and enzymatic assay). This concentration is 2000-fold higher than that needed to produce 50% inhibition of LiTryS (Table 1).
Systemic lupus erythematosus presenting as non-resolving pneumonia: a case report
Published in Acta Clinica Belgica, 2022
Sofie Stappers, Denise van der Graaff, Ilse Hoffman, Walter Moorkens, Inge Hantson, Inge Stappaerts, Vicky Nowé, Liesbeth Vervliet
Upon hospitalization for further management, a more thorough medical history of our patient was obtained. We specifically asked if she suffered from photosensitivity, Raynaud’s phenomenon, alopecia, sicca and joint pain. All of these symptoms were denied, except for the arthralgias: in 2011, our patient consulted a rheumatologist for swollen and painful joints in both hands. At the time, she had been diagnosed with therapy-resistant, seronegative (rheumatoid factor and anti-CCP negative), non-erosive rheumatoid arthritis. In chronological order, she was treated with Methotrexate, then Sulfasalazine and at last Leflunomide. All three of these remedies had a limited clinical effect and they all resulted in hepatotoxicity, which forced the attending physician to end these treatments. Interestingly, the laboratory results back then already showed positive ANA (1:320) and anti-dsDNA antibodies (1:10) with a normal lymphocyte count. Due to the lack of symptoms suggestive of SLE and the fact that 3% of ‘healthy’ individuals has an ANA titer of 9]. Captivatingly, the technique used to detect these anti-dsDNA antibodies was the Crithidia luciliae-based indirect immunofluorescence test (CLIFT), which is very specific for the diagnosis of SLE [10–12]. Haugbro et. al state that the specificity of positive anti-dsDNA antibodies for SLE, meaning a titer of ≥1:10, is 99% [10]. Moreover, in the last 8 years, our patient has not received any therapy for rheumatoid arthritis and still, upon this day, she has not developed any articular bone erosions nor joint deformities. Taking all these insights into account, we suspect that she was wrongfully diagnosed with rheumatoid arthritis and that these arthralgias were in fact the first manifestation of SLE.
Clinical use of anti-histone antibodies in idiopathic and drug-induced lupus
Published in Immunological Medicine, 2022
AHAs may refer to either total histones or histone subunits; although the latter is more often seen in the research laboratory. AHAs may be noted on indirect immunofluorescence that screens for ANAs. On the commonly-used HEp-2 substrate, AHAs commonly appear as a homogenous pattern; but is not specific for these autoantibodies [20]. Some false positives have also been noted on the Crithidia luciliae immunofluorescence test (CLIFT) (which normally detects anti-dsDNA antibodies) in some patients that produce AHA that can bind Chrithidia luciliae kinetoplast [21].