Liver ultrastructure in sheep fasciolosis

This experiment has studied the changes in the liver in sheep during experimental infection with fascioliasis. Sheep were infested with 300 adoliskaria and observed changes up to 142 days. At the ultrastructural level in animals with fascioliasis, destructive changes were found in the liver. In the nucleus, the number of nucleoli decreases or they disappear completely, fragmentation of heterochromatin occurs and the content of euchromatin increases. The karyolemma exfoliates from the nucleus, as a result of which the perinuclear space expands. Mitochondria swell, they are polymorphic, and have an electron-dense matrix. At the beginning of the invasion, their number increases, and then their vacuolization, destruction occurs, while under the action of anthelmintic drugs and fasciolus toxins, the structure of the endolasmic network first of all changes: its cavities expand, then fragmentation occurs. Ribosomes are sprayed into the cytoplasm of the hepatocyte. It should be noted that under the influence of hexichol, acemidophene and thiopagol in the liver, membrane structures change most significantly and undergo necrobiosis.

Bacterial Lipid II Analogs: Novel In Vitro Substrates for Mammalian Oligosaccharyl Diphosphodolichol Diphosphatase (DLODP) Activities

Mammalian protein N-glycosylation requires the transfer of an oligosaccharide containing 2 residues of N-acetylglucosamine, 9 residues of mannose and 3 residues of glucose (Glc3Man9 GlcNAc2) from Glc3Man9GlcNAc2-diphospho (PP)-dolichol (DLO) onto proteins in the endoplasmic reticulum (ER). Under some pathophysiological conditions, DLO biosynthesis is perturbed, and truncated DLO is hydrolyzed to yield oligosaccharyl phosphates (OSP) via unidentified mechanisms. DLO diphosphatase activity (DLODP) was described in vitro, but its characterization is hampered by a lack of convenient non-radioactive substrates. Our objective was to develop a fluorescence-based assay for DLO hydrolysis. Using a vancomycin-based solid-phase extraction procedure coupled with thin layer chromatography (TLC) and mass spectrometry, we demonstrate that mouse liver membrane extracts hydrolyze fluorescent bacterial lipid II (LII: GlcNAc-MurNAc(dansyl-pentapeptide)-PP-undecaprenol) to yield GlcNAc-MurNAc(dansyl-pentapeptide)-P (GM5P). GM5P production by solubilized liver microsomal proteins shows similar biochemical characteristics to those reported for human hepatocellular carcinoma HepG2 cell DLODP activity. To conclude, we show, for the first time, hydrolysis of lipid II by a eukaryotic enzyme. As LII and DLO are hydrolyzed by the same, or closely related, enzymes, fluorescent lipid II analogs are convenient non-radioactive substrates for investigating DLODP and DLODP-like activities.