Galactosylated poly(L-lysine) as a hepatotropic carrier of 9-beta-D-arabinofuranosyladenine 5'-monophosphate

D-Galactopyranosyl residues were coupled to poly(L-lysine) and the antiviral agents arabinofuranosyladenine 5'-monophosphate (ara-AMP) and acyclovir were conjugated with this glycosylated polymer. In mice the ara-AMP conjugate accomplished a selective drug delivery to liver cells.     

Management of cytologic material,preanalytic procedures and biobanking in lymph node cytopathology

The range of pathologies that lymph node (LN) fine needle cytology (FNC) may encounter is extremely wide and ancillary techniques, in addition to traditional smears, are generally required to reach reliable cytologic diagnoses. Storing part of the cytologic material may be useful or necessary for molecular testing. The main difficulties concern the generally small size of the sample and the different methods of acquisition of LN‐FNC. Therefore, the preanalytic phase is extremely important for LN‐FNC. This article outlines the management of LN‐FNC material, vials, technical devices (e.g.: additional smears, cytospin slides, LBC slides, cards, resins, etc.) and main ancillary techniques to assess their optimal application, taking into account the different diagnostic needs and cell storage.     

Lymph node fine‐needle cytology in the era of personalised medicine. Is there a role?

The 2016 World Health Organisation revised classification of lymphoma has sub‐classified well‐defined entities and added a number of provisional entities on the basis of new knowledge on genetic, epigenetics and phenotypical data; prognostic and predictive features are also part of this classification. New knowledge on well‐defined entities further enlightens the mechanisms of lymphomagenesis, which are more complex and multifactorial than once believed. Therapies are also more complex because traditional clinical trials have been integrated with new drugs and compounds with unique mechanisms of actions against distinct molecular targets. As lymphoma acquires additional genetic and phenotypic features over the time, pathological assessment is also necessary. Histological evaluation and tissue collection by surgical biopsies are necessary for phenotypical and molecular purposes; however, these are demanding procedures for both the patient and the health care system. At the same time, the choice of the best treatment for a specific entity, in different phases and different patients requires information that may not be available when the biopsy is performed. Fine needle aspiration cytology (FNAC) is successfully used in lymph nodes (LNs) in combination with different ancillary techniques and might be used to assess the phenotypic and genetic profile of specific targets and to get key information for therapy, in different phases and stages of the disease, with the option to re‐check the same target over time, without surgical excision. This brief review describes LN‐FNAC diagnostic criteria, current therapies for lymphomas and the potential role of LN‐FNAC in selecting non‐Hodgkin lymphomas patients for specific targeted treatments.     

The molecular characterization of a novel GH38 α-mannosidase from the crenarchaeon Sulfolobus solfataricus revealed its ability in de-mannosylating glycoproteins

α-Mannosidases, important enzymes in the N-glycan processing and degradation in Eukaryotes, are frequently found in the genome of Bacteria and Archaea in which their function is still largely unknown. The α-mannosidase from the hyperthermophilic Crenarchaeon Sulfolobus solfataricus has been identified and purified from cellular extracts and its gene has been cloned and expressed in Escherichia coli. The gene, belonging to retaining GH38 mannosidases of the carbohydrate active enzyme classification, is abundantly expressed in this Archaeon. The purified α-mannosidase activity depends on a single Zn²⁺ ion per subunit is inhibited by swainsonine with an IC₅₀ of 0.2 mM. The molecular characterization of the native and recombinant enzyme, named Ssα-man, showed that it is highly specific for α-mannosides and α(1,2), α(1,3), and α(1,6)-d-mannobioses. In addition, the enzyme is able to demannosylate Man₃GlcNAc₂ and Man₇GlcNAc₂ oligosaccharides commonly found in N-glycosylated proteins. More interestingly, Ssα-man removes mannose residues from the glycosidic moiety of the bovine pancreatic ribonuclease B, suggesting that it could process mannosylated proteins also in vivo. This is the first evidence that archaeal glycosidases are involved in the direct modification of glycoproteins.     

Metabolic response to cold and freezing of Osteospermum ecklonis overexpressing Osmyb4

The constitutive expression of the rice Osmyb4 gene in Arabidopsis plants gives rise to enhanced abiotic and biotic stress tolerance, probably by activating several stress-inducible pathways. However, the effect of Osmyb4 on stress tolerance likely depends on the genetic background of the transformed species.In this study, we explored the potential of Osmyb4 to enhance the cold and freezing tolerance of Osteospermum ecklonis, an ornamental and perennial plant native to South Africa, because of an increasing interest in growing this species in Europe where winter temperatures are low.Transgenic O. ecklonis plants were obtained through transformation with the Osmyb4 rice gene under the control of the CaMV35S promoter.We examined the phenotypic adaptation of transgenic plants to cold and freezing stress. We also analysed the ability of wild-type and transgenic Osteospermum to accumulate several solutes, such as proline, amino acids and sugars. Using nuclear magnetic resonance, we outlined the metabolic profile of this species under normal growth conditions and under stress for the first time. Indeed, we found that overexpression of Osmyb4 improved the cold and freezing tolerance and produced changes in metabolite accumulation, especially of sugars and proline. Based on our data, it could be of agronomic and economic interest to use this gene to produce Osteospermum plants capable of growing in open field, even during the winter season in climatic zone Z9.     

Targeting of antiviral drugs by coupling with protein carriers

Side effects of antiviral drugs might be circumvented by their selective delivery into infected cells. This targeting can be obtained by conjugation of the drugs to macromolecules which are taken up specifically by the infected cells. The experiments reviewed, on this approach to antiviral chemotherapy, are mainly directed at improving the chemotherapeutic index of adenine arabinoside (ara-A) in the treatment of chronic hepatitis B by its coupling to galactosyl terminating glycoproteins.     

The determination of uroporphyrinogen decarboxylase in tissues by high-performance liquid chromatography coupled to fluorescence detection

High-performance liquid chromatography coupled to fluorescence detection wsa utilized for the separation and quantitation of porphyrins as methyl esters. The method (developed for biochemical investigation of porphyrias) permitted quantitation down to 0.2 nanograms of porphyrins per sample. One of the possible applications is the study of the enzyme uroporphyrinogen decarboxylase. No significant difference was found between two methods of methylation and extraction of the samples prior to chromatography.