Homeobox Genes Expressed During Echinoderm Arm Regeneration

Regeneration in echinoderms has proved to be more amenable to study in the laboratory than the more classical vertebrate models, since the smaller genome size and the absence of multiple orthologs for different genes in echinoderms simplify the analysis of gene function during regeneration. In order to understand the role of homeobox-containing genes during arm regeneration in echinoderms, we isolated the complement of genes belonging to the Hox class that are expressed during this process in two major echinoderm groups: asteroids (Echinaster sepositus and Asterias rubens) and ophiuroids (Amphiura filiformis), both of which show an extraordinary capacity for regeneration. By exploiting the sequence conservation of the homeobox, putative orthologs of several Hox genes belonging to the anterior, medial, and posterior groups were isolated. We also report the isolation of a few Hox-like genes expressed in the same systems.     

Decolorization of an industrial effluent by free and immobilized cells of <Emphasis Type="Italic">Stenotrophomonas maltophilia</Emphasis> AAP56<Emphasis Type="Italic">.</Emphasis> Implementation of efficient down flow column reactor

A bacterial strain AAP56, isolated from a polluted soil (from Kelibia city) and identified as Stentrophomonas maltophilia, was particularly interesting for its ability to decolorize recalcitrant dyes of an industrial effluent: SITEX Black. The final percentage decolorization 60% was shown by bacterial culture after incubation in LB medium at 30°C under shaking conditions. The decolorization was closely correlated with the metabolic bacterial growth. The replacement of yeast extract in LB medium composition by soya flour was clearly efficient to enhance the percentage decolorization by 20% and also to reduce the growth medium cost 60-fold. The bacteria were able to reduce 23% from the initial COD and 28% from the initial BOD₅ of the effluent. The immobilization of bacterial cells in calcium alginate beads improved by 25% the effectiveness of the biotransformation within 24 h in batch conditions. The potential of a downflow fixed column reactor (DFCR) to decolorize SITEX Black was evaluated under dilution rate. The best decolorization percentage (82%) was recorded at 0.3 h⁻¹. This bioprocess seems to be a potentially useful method to remediate the colored textile wastewater.     

Identification of a novel selective H1-antihistamine with optimized pharmacokinetic properties for clinical evaluation in the treatment of insomnia

Analogs of the known H₁-antihistamine R-dimethindene with suitable selectivity for key GPCRs, P450 enzymes and hERG channel were assessed for metabolism profile and in vivo properties. Several analogs were determined to exhibit diverse metabolism. One of these compounds, 10a, showed equivalent efficacy in a rat EEG/EMG model to a previously identified clinical candidate and a potentially superior pharmacokinetic profile as determined from a human microdose study.     

Analysis of membrane protein genes in a Brazilian isolate of Anaplasma marginale

The sequencing of the complete genome of Anaplasma marginale has enabled the identification of several genes that encode membrane proteins, thereby increasing the chances of identifying candidate immunogens. Little is known regarding the genetic variability of genes that encode membrane proteins in A. marginale isolates. The aim of the present study was to determine the degree of conservation of the predicted amino acid sequences of OMP1, OMP4, OMP5, OMP7, OMP8, OMP10, OMP14, OMP15, SODb, OPAG1, OPAG3, VirB3, VirB9-1, PepA, EF-Tu and AM854 proteins in a Brazilian isolate of A. marginale compared to other isolates. Hence, primers were used to amplify these genes: omp1, omp4, omp5, omp7, omp8, omp10, omp14, omp15, sodb, opag1, opag3, virb3, VirB9-1, pepA, ef-tu and am854. After polimerase chain reaction amplification, the products were cloned and sequenced using the Sanger method and the predicted amino acid sequence were multi-aligned using the CLUSTALW and MEGA 4 programs, comparing the predicted sequences between the Brazilian, Saint Maries, Florida and A. marginale centrale isolates. With the exception of outer membrane protein (OMP) 7, all proteins exhibited 92-100% homology to the other A. marginale isolates. However, only OMP1, OMP5, EF-Tu, VirB3, SODb and VirB9-1 were selected as potential immunogens capable of promoting cross-protection between isolates due to the high degree of homology (over 72%) also found with A. (centrale) marginale.     

Semisynthesis and in vitro anticancer activities of andrographolide analogues

The plant Andrographis paniculata found throughout Southeast Asia contains Andrographolide 1, a diterpenoid lactone, which has antitumour activities against in vitro and in vivo breast cancer models. In the present study, we report on the synthesis of andrographolide derivatives, 3,19-isopropylideneandrographolide (2), 14-acetyl-3,19-isopropylideneandrographolide (3) and 14-acetylandrographolide (4), and their in vitro antitumour activities against a 2-cell line panel consisting of MCF-7 (breast cancer cell line) and HCT-116 (colon cancer cell line). Compounds 2 and 4 were also screened at the US National Cancer Institute (NCI) for their activities against a panel of 60 human cancer cell lines derived from nine cancer types. Compound 2 was found to be selective towards leukaemia and colon cancer cells, and compound 4 was selective towards leukaemia, ovarian and renal cancer cells at all the dose-response parameters. Compounds 2 and 4 showed non-specific phase of the cell cycle arrest in MCF-7 cells treated at different intervals with different concentrations. NCI's COMPARE and SOM mechanistic analyses indicated that the anticancer activities of these new class of compounds were not similar to that of standard anticancer agents, suggesting novel mechanism(s) of action.     

Overexpression of homologous phytochrome genes in tomato: exploring the limits in photoperception

Transgenic tomato [Lycopersicon esculentum (=Solanum lycopersicum)] lines overexpressing tomato PHYA, PHYB1, or PHYB2, under control of the constitutive double-35S promoter from cauliflower mosaic virus (CaMV) have been generated to test the level of saturation in individual phytochrome-signalling pathways in tomato. Western blot analysis confirmed the elevated phytochrome protein levels in dark-grown seedlings of the respective PHY overexpressing (PHYOE) lines. Exposure to 4 h of red light resulted in a decrease in phytochrome A protein level in the PHYAOE lines, indicating that the chromophore availability is not limiting for assembly into holoprotein and that the excess of phytochrome A protein is also targeted for light-regulated destruction. The elongation and anthocyanin accumulation responses of plants grown under white light, red light, far-red light, and end-of-day far-red light were used for characterization of selected PHYOE lines. In addition, the anthocyanin accumulation response to different fluence rates of red light of 4-d-old dark-grown seedlings was studied. The elevated levels of phyA in the PHYAOE lines had little effect on seedling and adult plant phenotype. Both PHYAOE in the phyA mutant background and PHYB2OE in the double-mutant background rescued the mutant phenotype, proving that expression of the transgene results in biologically active phytochrome. The PHYB1OE lines showed mild effects on the inhibition of stem elongation and anthocyanin accumulation and little or no effect on the red light high irradiance response. By contrast, the PHYB2OE lines showed a strong inhibition of elongation, enhancement of anthocyanin accumulation, and a strong amplification of the red light high irradiance response.