Depleting neuronal PrP in prion infection prevents disease and reverses spongiosis

The mechanisms involved in prion neurotoxicity are unclear, and therapies preventing accumulation of PrPSc, the disease-associated form of prion protein (PrP), do not significantly prolong survival in mice with central nervous system prion infection. We found that depleting endogenous neuronal PrPc in mice with established neuroinvasive prion infection reversed early spongiform change and prevented neuronal loss and progression to clinical disease. This occurred despite the accumulation of extraneuronal PrPSc to levels seen in terminally ill wild-type animals. Thus, the propagation of nonneuronal PrPSc is not pathogenic, but arresting the continued conversion of PrPc to PrPSc within neurons during scrapie infection prevents prion neurotoxicity.     

Cytokinins in iris bulb-scales under flower-inducing conditions

Cytokinin activity was detected by means of the soybean callus test in the scales of Iris hollandica Hoog cultivar ‘Prof. Blaauw’ during the cold treatment for flower formation. A component of the biological activity extracted from the bulb scales coeluted with zeatin riboside when subjected to high-performance liquid chromatography. It is suggested that the cytokinins in the scales may be involved in flower formation.     

Molecular characterization of Fusarium oxysporum f.sp. cichorii pathogenic on chicory (Cichorium intybus)

Fusarium oxysporum is a ubiquitous soilborne ascomycete responsible for vascular wilt in many plant species worldwide. This species comprises more than 120 putative host-specific formae speciales capable of causing marked economic losses. In summer 2009, wilt symptoms, including chlorosis and poor development of the root system, were observed on cultivars of chicory (Cichorium intybus) in northern Italy. The causal agent isolated from symptomatic tissues in this case was identified as F. oxysporum on the basis of both morphological features and molecular analyses. In this work, we attempted to characterize the isolates of F. oxysporum from C. intybus by both biological and molecular approaches. Pathogenicity trials performed on five species of the Asteraceae family with isolates of F. oxysporum from C. intybus indicated that the pathogen has a unique host range, infecting chicory only. Neither lettuce nor endive, lawn daisy or Paris daisy developed the disease. Five cultivars within C. intybus species were tested, and the cv. ??Clio?? was the most susceptible. Phylogenetic analyses relative to the ribosomal intergenic spacer (IGS) and translation elongation factor 1-alpha (EF1-??) assigned isolates pathogenic to chicory to a single cluster, distinct from other pathogenic F. oxysporum. In light of these findings, we propose to designate this organism as Fusarium oxysporum f.sp. cichorii.     

Design and Synthesis of Pro-Apoptotic Compounds Inspired by Diatom Oxylipins

Oxylipins are a large and diverse family of fatty acid derivatives exhibiting different levels of oxidation of the carbon chain. They are involved in many biological functions in mammals, plants and diatoms. In this last group of organisms, they are suggested to play a role in the reproductive failure of copepod predators, showing clear pro-apoptotic effects on newborn nauplii. In this work, these compounds were tested for the ability to induce mitotic arrest in sea urchin embryos. We show for the first time that oxylipins have an increased efficacy in their corresponding methylated form. Natural oxylipins were also used as an inspiration for the rational design and synthesis of stable chemical analogs with apoptotic activity against tumor cell lines. This approach led to the synthesis of the linear C15-ketol (22) that was shown to induce apoptosis in human leukemia U-937 cells. These results are proof of the concept of the use of eco-physiological considerations as a platform to guide the search for novel drug candidates.     

Studies on umami taste. Synthesis of new guanosine 5'-phosphate derivatives and their synergistic effect with monosodium glutamate

A number of N2-alkyl and N2-acyl derivatives of guanosine 5'-phosphate (GMP) have been synthesized and tested for their synergistic effect with monosodium L-glutamate (MSG), the prototypical substance imparting umami taste to savory-based foods. Capacities to enhance the taste intensity of MSG (gamma values) were estimated through subjective comparisons of MSG/nucleotide mixtures in water with appropriate solutions of MSG alone. Assuming beta = gamma[nucleotide]/gamma[IMP], beta values of the N2-substituted GMPs were found in the range 1.2-5.7. Such values appear to be related to the chain length of the substituent in the 2-position of the purine nucleus and dependent on the replacement of a CH 2 group with an S atom and/or with an alpha-CO group. These findings indicate that the exocyclic NHR group of the guanine moiety is actively implicated in the synergism between GMP derivatives and MSG. Theoretical calculations suggest that an anti conformation is probably assumed by ribonucleotide molecules interacting with umami receptors.     

Multilobular tumour of bone of the thoracic wall in a cat

Multilobular tumour of bone is a rare neoplasm of the skull in middle-aged, medium-to-large breed dogs even if a few cases have also been described in cats and one horse. The aim of the present paper is to show both the computed-tomography features and the pathological findings of the above neoplasm affecting the thoracic wall of a cat. To the best of the authors' knowledge, such anomalous tumour localisation has never been reported and imaged in feline medicine.     

Koi herpesvirus and carp edema virus threaten common carp aquaculture in Croatia

Common carp (Cyprinus carpio) is a very important fish species for warm-water aquaculture in Croatia. All Croatian carp farms are subjected to a surveillance programme for the presence of koi herpesvirus (KHV), causing a deadly disease called koi herpesvirus disease (KHVD). However, there is no surveillance for other viral pathogens of importance like carp edema virus (CEV), a causative agent of koi sleepy disease (KSD). During regular testing within the KHVD surveillance programme, we tested samples for CEV simultaneously. The screening indicated possible outbreaks of KHVD and KSD. During 2016, KHVD broke out in an isolated area and soon thereafter a KHV eradication programme was successfully performed. However, during 2018 and 2019, two additional mortality events occurred in lakes in the southern part of Croatia during the spring. Samples from both events tested positive for CEV. An epidemiological investigation confirmed the introduction of infected carps from an infected farm to one of the lakes. To prevent the spreading of CEV into open waters, it is of utmost importance to introduce CEV testing before fish movement or to perform regular testing of all carp farms in the country to determine CEV prevalence for the purpose of implementation of control measures.