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CT, MRI, and NMR Spectroscopy in Alzheimer Disease*
Published in Robert E. Becker, Ezio Giacobini, Alzheimer Disease, 2020
Liane J. Leedom, Bruce L. Miller
Why these phosphodiesters accumulate is unknown. However, both glycerophosphorylcholine and glycerophosphorylethanolamine are products of phospholipid degradation produced by the action of phospholipase A1 and A2 on the phosphatidyl forms of these compounds. It is possible that there is increased catabolism of brain phospholipids in AD and Farooqui et al. (1988 and 1989) have shown that the concentration of monoacyl and diacylglycerol lipases is 7 times higher in AD autopsy brain compared to non- demented elderly. These findings warrant further investigation.
African trypanosomiasis
Published in F. Y. Liew, Vaccination Strategies of Tropical Diseases, 2017
Although there is no evidence to support these possibilities (nor much research effort), the role of phospholipase A1 may be interesting. African trypanosomes produce this enzyme copiously, at the highest level known in biology.76 Its level may be related to the constant developmental changes in trypanosome membranes; on the other hand, it could conceivably play a role as a secreted product. Partial or complete reliance of a parasite on the activity of a secreted product would be a weak point in its life cycle, clearly amenable to a vaccination approach.
The pathophysiology of salmonid cryptobiosis and Glossina-transmitted mammalian trypanosomiasis in livestock
Published in G. F. Wiegertjes, G. Flik, Host-Parasite Interactions, 2004
When T. congolense is allowed to autolyse at 20°C it generates phospholipase A1 which acts on endogenous phosphatidyl choline to generate fatty acids (e.g. linoleic and palmitic). Although these fatty acids can cause haemolysis under in vitro conditions they are not likely an important cause of the anaemia under in vivo conditions as their activity is blocked by serum albumin (Tizard et al., 1979). Although the phospholipase and its products are not the primary cause of the anaemia, Tizard et al., (1979) however suggested that these ‘toxins’ that are released from dead trypanosomes are capable of causing lesions characteristic of trypanosomiasis and may represent a major pathogenic mechanism in the disease.
Campylobacter jejuni permeabilizes the host cell membrane by short chain lysophosphatidylethanolamines
Published in Gut Microbes, 2022
Xuefeng Cao, Chris H.A. van de Lest, Liane Z.X. Huang, Jos P.M. van Putten, Marc M.S.M. Wösten
Lysophospholipids (LPLs) are bioactive signaling molecules containing a single fatty acid tail. In eukaryotic cells, LPLs exhibit diverse biological properties, such as promoting cell growth, acting as potent lipid mediators, or reducing bacterial infections.1,2 LPLs are generated as metabolic intermediates in phospholipid synthesis or during membrane degradation.3 The formation of LPLs from phospholipids is due to activation of phospholipase A1 or A2. Phospholipase A1 (PldA1) and phospholipase A2 (PldA2), hydrolyzing the stereospecific numbering (Sn)-1 and −2 acyl chain, respectively.4 (Sn)-1 LPLs possess more shorter, saturated acyl chains than (Sn)-2 LPLs while (Sn)-2 LPLs possess more unsaturated acyl chains.5 (Sn)-1 LPLs and (Sn)-2 LPLs might have different biological functions as only (Sn)-1 LPLs can act as mediators of antimicrobial activity toward Gram-positive bacteria.6 Lysophosphatidic acid (lysoPA) is important in controlling and signaling cancer;7 lysophosphatidylcholine (lysoPC) evokes cellular injury by oxidative events that involve formation of low-density lipoprotein. Both lysoPA and lysoPC of the host trigger the release of the proinflammatory flagellin from Salmonella thereby enhancing the innate and inflammatory responses toward this bacterium.8 The role of other LPLs like lysophosphatidylethanolamine (lysoPE) has not been elucidated to such a high degree.
Precision medicine in the allergy clinic: the application of component resolved diagnosis
Published in Expert Review of Clinical Immunology, 2022
Carmen Panaitescu, Laura Haidar, Maria Roxana Buzan, Manuela Grijincu, Daniela Elena Spanu, Catalina Cojanu, Alexandru Laculiceanu, Roxana Bumbacea, Ioana Agache
Seventy-six allergens are currently characterized from Hymenoptera venom [50]. In Europe, the most frequent elicitors of allergic reactions to venom are honeybees (Apis mellifera), yellow jackets (Vespula vulgaris) and paper wasps (Polistes dominula) [51]. Currently, 12 allergens from honeybee venom (Api m 1–12), and 5 from each paper wasp and yellow jacket (Pol d 1–5 and Ves v 1–3, 5, 6) have been characterized. These allergens show different abundances within venom extracts –Api m 1 (phospholipase) and Api m 4 (mellitin) are abundant (12%), while the others are below 1% [52]. Similarly in yellow jacket venom extract, Ves v 1 (phospholipase A1) and Ves v 5 (antigen 5) are more abundant [51]. These allergens also show some degree of cross-reactivity, partially due to protein glycosylation with cross-reactive carbohydrate determinants (CCDs), but also due to the homology among related insect species [53,54]. Api m 1–5 and 10, Ves v 1 and 5, Pol d 1 and 5 are commercially available as recombinant allergens for diagnosis [54]. sIgE against Api m 1, 3, 4, 10 is a useful marker for honeybee venom allergy. Yellow jacket venom allergy can be evaluated using Ves v 1 and Ves v 5, which are the most valuable for differentiation between honeybee and yellow jacket venom allergy, but they are cross-reactive with their homologues from paper wasp venom (Table 2) [51,55].