The Bone Marrow-Mediated Protection of Myeloproliferative Neoplastic Cells to Vorinostat and Ruxolitinib Relies on the Activation of JNK and PI3K Signalling Pathways

The classical BCR-ABL-negative Myeloproliferative Neoplasms (MPN) are a group of heterogeneous haematological diseases characterized by constitutive JAK-STAT pathway activation. Targeted therapy with Ruxolitinib, a JAK1/2-specific inhibitor, achieves symptomatic improvement but does not eliminate the neoplastic clone. Similar effects are seen with histone deacetylase inhibitors (HDACi), albeit with poorer tolerance. Here, we show that bone marrow (BM) stromal cells (HS-5) protected MPN-derived cell lines (SET-2; HEL and UKE-1) and MPN patient-derived BM cells from the cytotoxic effects of Ruxolitinib and the HDACi Vorinostat. This protective effect was mediated, at least in part, by the secretion of soluble factors from the BM stroma. In addition, it correlated with the activation of signalling pathways important for cellular homeostasis, such as JAK-STAT, PI3K, JNK, MEK-ERK and NF-κB. Importantly, the pharmacological inhibition of JNK and PI3K pathways completely abrogated the BM protective effect on MPN cell lines and MPN patient samples. Our findings shed light on mechanisms of tumour survival and may indicate novel therapeutic approaches for the treatment of MPN.     

From sequence to 3D structure of hyperbranched molecules: application to surface modified PAMAM dendrimers

The molecular modeling of hyperbranched molecules is currently constrained by difficulties in model building, due partly to lack of parameterization of their building blocks. We have addressed this problem with specific relevance to a class of hyperbranched macromolecules known as dendrimers by describing a new concept and developing a method that translates monomeric linear sequences into a full atomistic model of a hyperbranched molecule. Such molecular-modeling-based advances will enable modeling studies of important biological interactions between naturally occurring macromolecules and synthetic macromolecules. Our results also suggest that it should be possible to apply this sequence-based methodology to generate hyperbranched structures of other dendrimeric structures and of linear polymers.     

Marine fungi from two sandy beaches in Portugal

The occurrence of marine fungi associated with, pieces of wood, driftwood and dead plant stems, in the intertidal zone of two sandy beaches on the Portuguese west coast, was surveyed for 5 mo. Out of 90 samples scanned 70% had sporulating marine fungi. Thirty-five marine fungal taxa were identified (27 Ascomycota, six anamorphic fungi and two unidentified taxa), out of which 11 species were common to both beaches. Most taxa were infrequent (< or =10%), with the exception of Kirschsteiniothelia maritima (10-20%). The average number of fungi per sample was 0.91 for both beaches. Fifteen species are new records for Portugal. Samples were examined immediately after they were taken to the laboratory, as well as after incubation in moist chamber, for up to 10 mo.     

Morphologic, morphometrical, and histological aspects of the eggs of four species of the genera Meccus (Hemiptera, Reduviidae, Triatominae)

The objective of this work was to analyze the morphological, morphometrical, and histological characteristics of eggs of four triatomine bugs species still not studied, in order to understand phylogenetic aspects and to facilitate parameters used in taxonomy, with the purpose of a specific and generic characterization of these vectors in public health. The eggs of each species had come from the collections of the Laboratory of Triatomine bugs and Culicid mosquitoes of the Faculdade de Saúde Pública - USP (Faculty of Public Health/USP). The morphologic studies were carried out through optic microscopy (OM) and scanning electronic microscopy (SEM). The eggs were measured with the help of the digital paquimeter Starrett 727. In relation to histological measures, Microtome Leica RM 2145 was used. Similarities were evidenced in the exocorial architecture of the eggs when they were studied by OM and SEM. This similarity among the eggs suggests a recent speciation, probably derived from common ancestry, representing a monophyletic group. Some structures were also detected by the histological cuts. The study has contributed to the magnification and recognition in generic and specific terms of the Triatominae subfamily. These new data will be able to subsidize a better understanding to determine roles for each vector species and to facilitate parameters to be used in taxonomy.     

Design, synthesis, and in vivo evaluation of oxamniquine methacrylate and acrylamide prodrugs

Oxamniquine is an antiparasitic agent commonly used in therapeutics against Schistosoma mansoni. Although it is well tolerated, some adverse effects justify the search for new compounds with prolonged biological action, so that monomeric and polymeric oxamniquine prodrugs were designed. Synthetic results assisted by molecular modeling study showed the possibility to obtain the corresponding monomeric forms of the oxamniquine methacrylate (1) and oxamniquine acrylamide (2). Successful copolymerization procedure only occurred on the methacrylic compound, generating the oxamniquine methacrylate copolymer (3). Submitted to a preliminary in vivo biological evaluation, a similar oxamniquine profile was observed to the monomeric forms although an inadequate drug release may be responsible for the methacrylic copolymer failure.     

Structure-activity relationship of antileishmanials neolignan analogues

Twenty-two synthetic analogues of neolignans comprising beta-ketoethers and beta-ketosulfides were obtained from condensation reactions among beta-bromoketones and phenols or thiophenols, respectively, in basic solutions, and assayed in vitro for activity against intracellular Leishmania amazonensis and Leishmania donovani amastigotes, the causative agents of cutaneous and visceral leishmaniasis. The highest selective activity was found for compounds with sulfur bridges, whereas beta-ketosulphoxides and beta-ketosulphones had significantly less growth inhibitory activity. Compounds 2-[(4-chlorophenyl)thio]propan-1-one and 1-(3,4-dimethoxy)-2-[(4-methylphenyl)thio]propan-1-one were the most potent, inhibiting the growth parasite species by over 90% at microgram/mL, but only compound 1-(3,4-dimethoxy)-2-[(4-methylphenyl)thio]propan-1-one was selectively toxic to the parasites.     

Catalysis and structural properties of Leishmania infantum glyoxalase II: trypanothione specificity and phylogeny

The glyoxalase pathway catalyzes the formation of d-lactate from methylglyoxal, a toxic byproduct of glycolysis. In trypanosomatids, trypanothione replaces glutathione in this pathway, making it a potential drug target, since its selective inhibition might increase methylglyoxal concentration in the parasites. Two glyoxalase II structures were solved. One with a bound spermidine molecule (1.8 A) and the other with d-lactate at the active site (1.9 A). The second structure was obtained by crystal soaking with the enzyme substrate (S)-d-lactoyltrypanothione. The overall structure of Leishmania infantum glyoxalase II is very similar to its human counterpart, with important differences at the substrate binding site. The crystal structure of L. infantum glyoxalase II is the first structure of this enzyme from trypanosomatids. The differential specificity of glyoxalase II toward glutathione and trypanothione moieties was revealed by differential substrate binding. Evolutionary analysis shows that trypanosomatid glyoxalases II diverged early from eukaryotic enzymes, being unrelated to prokaryotic proteins.     

Ascomycetous yeast species recovered from grapes damaged by honeydew and sour rot

Aims: To identify ascomycetous yeasts recovered from sound and damaged grapes by the presence of honeydew or sour rot. Methods and Results: In sound grapes, the mean yeast counts ranged from 3·20 ± 1·04 log CFU g^?1 to 5·87 ± 0·64 log CFU g^?1. In honeydew grapes, the mean counts ranged from 3·88 ± 0·80 log CFU g^?1 to 6·64 ± 0·77 log CFU g^?1. In sour rot grapes counts varied between 6·34 ± 1·03 and 7·68 ± 0·38 logCFU g^?1. Hanseniaspora uvarum was the most frequent species from sound samples. In both types of damage, the most frequent species were Candida vanderwaltii, H. uvarum and Zygoascus hellenicus. The latter species was recovered in high frequency because of the utilization of the selective medium DBDM (Dekkera/Brettanomyces differential medium). The scarce isolation frequency of the wine spoilage species Zygosaccharomyces bailii (in sour rotten grapes) and Zygosaccharomyces bisporus (in honeydew affected grapes) could only be demonstrated by the use of the selective medium ZDM (Zygosaccharomyces differential medium). Conclusions: The isolation of several species only from damaged grapes indicates that damage constituted the main factor determining yeast diversity. The utilization of selective media is required for eliciting the recovery of potentially wine spoilage species. Significance and Impact of the Study: The impact of damaged grapes in the yeast ecology of grapes has been underestimated.     

Olfactory sensitivity of the Mozambique tilapia to conspecific odours

Electro-olfactogram (EOG) recordings from female Mozambique tilapia Oreochromis mossambicus gave large responses (up to 45 mV) to water previously occupied by sexually active males. Male body-fluids also elicited very strong olfactory responses with thresholds of detection of c . 1: 10^6.9 (bile), 1: 10^5.2 (urine) and 1: 10^4.9 (faeces). Considering the likely rates of release of these fluids, it is the urine that provides the strongest olfactory stimulus for females. Crude fractionation of the male water and body-fluids implicated: (a) sulphated compounds, possibly steroids, as the most potent odorant in the urine (and water previously occupied by males), and (b) bile acids in the faeces and bile. Although the olfactory system of Mozambique tilapia was found to be sensitive to a range of amino acids and bile acids, steroids present in Mozambique tilapia plasma and steroids known to act as pheromones in other species elicited negligible responses. Although the present study clearly suggests that chemical communication might be important in Mozambique tilapia, the exact chemical identity of the compounds involved, and their biological functions, remain to be elucidated.