Influence of liposomal local anesthetics on platelet aggregation in vitro

We assessed the effect of local anesthetics (LA) from different families such as esters (benzocaine), linear aminoamides (lidocaine) and cyclic aminoamides (bupivacaine) on the platelet aggregation induced by ADP. Liposomal formulations of the three LA, prepared with egg phosphatidylcholine:cholesterol alpha-tocopherol, were also tested. The three LA were able to inhibit platelet aggregation induced by ADP, in the following order: bupivacaine > lidocaine > benzocaine. After encapsulation into liposomes the inhibitory effect increased for all anesthetics studied, showing that aggregation tests could be used to assess the toxicity of new drug formulations.     

Centrin in Giardia lamblia - ultrastructural localization

Giardia lamblia is a multiflagellar parasite and one of the earliest diverging eukaryotic cells. It possesses a complex cytoskeleton based on different groups of microtubular structures - a ventral adhesive disc, four pairs of flagella, a median body and funis. Centrin is an important member of the EF-hand family of calcium-binding proteins, and it is known to show calcium-sensitive contractile behaviour. In the present study, we performed an ultrastructural localization of centrin in G. lamblia using several monoclonal antibodies to centrin. Microtubular structures such as the basal bodies, all the flagella axonemes, the adhesive disc, funis, and the median bodies presented positive labelling to centrin. In addition, the dense rods also demonstrated positive labelling. These results show that centrin is located in key positions related to microtubules. The role of centrin in these dynamic regions is discussed.     

Tuber borchii fruit body: 2-dimensional profile and protein identification

The formation of the fruit body represents the final phase of the ectomycorrhizal fungus T. borchii life cycle. Very little is known concerning the molecular and biochemical processes involved in the fructification phase. 2-DE maps of unripe and ripe ascocarps revealed different protein expression levels and the comparison of the electropherograms led to the identification of specific proteins for each developmental phase. Associating micropreparative 2-DE to microchemical approaches, such as N-terminal sequencing and 2-D gel-electrophoresis mass-spectrometry, proteins playing pivotal roles in truffle physiology were identified.     

Comparison of PCR, electrochemical enzyme-linked immunosorbent assays, and the standard culture method for detecting salmonella in meat products

An electrochemical enzyme-linked immunosorbent assay (ELISA) coupled with flow injection analysis (ELISA-FIA) and a PCR-based method using ST11 and ST15 primers for detecting salmonellae in meat were evaluated in comparison with the International Organization for Standardization (ISO) culture method. The methods were applied to experimentally contaminated and naturally contaminated meat samples. The results showed that both ELISA-FIA and PCR allowed detection of salmonella in a product contaminated with a low number of the microorganisms (1 to 10 salmonellae/25 g) after only 5 h of incubation of preenrichment broth, and they were just as effective as the ISO method.     

Agrobacterium tumefaciens-mediated genetic transformation of the entomopathogenic fungus Beauveria bassiana

Agrobacterium tumefaciens-mediated transformation (agro-transformation) was successfully applied to the entomogenous fungus Beauveria bassiana. Conidia of B. bassiana were transformed to hygromycin B resistance using the hph gene of Escherichia coli as the selective trait, under the control of a heterologous fungal promoter and the Aspergillus nidulans trpC terminator. The efficiency of transformation was up to 28 and 96 transformants per 10(4) and 10(5) target conidia, respectively, using three distinct vectors. High mitotic stability of the transformants (80-100%) was demonstrated after five successive transfers on a nonselective medium. Abortive transformants were observed for all the hph(r) vectors used. Putative transformants were analysed for the presence of the hph gene by PCR and Southern analysis. The latter analysis revealed the integration of two or more copies of the hph gene in the genome. The agro-transformation method was found to be effective for the isolation of B. bassiana hygromycin resistant transformants and may represent a useful tool for insertional mutagenesis studies in this fungus.     

Modifications of serotonergic and adrenergic receptor concentrations in the brain of aggressive Canis familiaris

The aim of the study was to measure beta-adrenergic (beta-AR) and serotonergic (5-HTR) receptor concentrations in different brain areas (frontal cortex, hippocampus, hypothalamus and thalamus) of normal and aggressive dogs. Eight adult male dogs, 4.2+/-0.6 years old, showing no clinical signs but aggression, were used for the study. Eight healthy male dogs, 4.4+/-0.8 years old, with no history of neurological and/or behavioural disorders and accidental death, were used as controls. The whole frontal cortex, hippocampus, thalamus and hypothalamus were collected after euthanasia and plasma membrane fractions obtained by ultracentrifugation. beta-AR and 5-HTR were measured by binding assays using specific radioligand [(-)[3H]CGP 12177 and 5-hydroxy[3H]-tryptamine trifluoroacetate, respectively]. A significant decrease in beta-AR levels was observed in the frontal cortex (P=0.001), hippocampus (P<0.0001), and thalamus (P<0.0001) of aggressive dogs compared to controls. As far as 5-HTR are concerned, two receptor subtypes were detected. The two subtypes were classified as low-affinity (5-HTR LA) and high-affinity (5-HTR HA) serotonergic receptors for [3H]-hydroxytryptamine, on the basis of their affinity for [3H]-hydroxytryptamine. 5-HTR LA significantly increased in the whole central nervous system (CNS) area of aggressive dogs (frontal cortex P=0.071; hippocampus P=0.0013; thalamus P<0.0001; hypothalamus P=0.0004); 5-HTR HA significantly increased only in the thalamus (P=0.0005) and hypothalamus (P=0.0002). Results suggest the possible role played by the catecholaminergic and serotonergic systems in canine aggressive behaviour. The understanding of the biological basis of canine aggression may enable the development of pharmacological treatments that would target specific neurotransmitter systems.     

New class of potent antinociceptive and antiplatelet 10H-phenothiazine-1-acylhydrazone derivatives

In this work, we reported the synthesis and evaluation of the analgesic, antiinflammatory, and antiplatelet properties of new phenothiazine-attached acylhydrazone derivatives (6), designed exploring the molecular hybridization approach between antipsychotic chlorpromazine (4) and other heterocyclic derivatives (3) and (5) developed at LASSBio. Target compounds were synthesized in very good yields exploiting diphenylamine (7) as starting material, through regioselective functionalization of the C-1 position of 10H-phenothiazine ring. The evaluation of platelet antiaggregating profile lead us to identify a new potent prototype of antiplatelet derivative, that is (6a) (IC(50)=2.3 microM), which acts in arachidonic acid pathway probably by inhibition of platelet COX-1 enzyme. Additionally, the change of para-substituent group of acylhydrazone framework permitted us to identify hydrophilic carboxylate derivative (6g) and hydrophobic bromo derivative (6b) as two new leads of analgesics more active than dipyrone used as standard and with selective peripheral or central mechanism of action.     

Genotypic diversity of oscillatoriacean strains belonging to the genera Geitlerinema and Spirulina determined by 16S rDNA restriction analysis

Genotypic diversity of several cyanobacterial strains mostly isolated from marine or brackish waters, belonging to the genera Geitlerinema and Spirulina, was investigated by amplified 16S ribosomal DNA restriction analysis and compared with morphological features and response to salinity. Cluster analysis was performed on amplified 16S rDNA restriction profiles of these strains along with profiles obtained from sequence data of five Spirulina-like strains, including three representatives of the new genus Halospirulina. Our strains with tightly coiled trichomes from hypersaline waters could be assigned to the Halospirulina genus. Among the uncoiled strains, the two strains of hypersaline origin clustered together and were found to be distant from their counterparts of marine and freshwater habitat. Moreover, another cluster, formed by alkali-tolerant strains with tightly coiled trichomes, was well delineated.