Amino acids and low-molecular-weight carbohydrates of some marine red algae

Amino acids and low-MW carbohydrates of 18 red algae have been analyzed. Several non-protein amino acids have been identified, including pyrrolidine-2,5-dicarboxylic acid (3c) and N-methylmethionine sulfoxide (5), new natural products, and 13 known compounds, citrulline, β-alanine, γ-aminobutyric acid, baikiain (1), pipecolic acid (2), domoic acid (3a), kainic acid (3b), azetidine-2-carboxylic acid (4), methionine sulfoxide taurine, N-methyltaurine, N,N-dimethyltaurine and N,N,N-trimethyltaurine. Sugars present were mainly floridoside, isofloridoside and mannoglyceric acid. Details of the structural elucidation of new compounds are also given.     

Synthesis and evaluation of N-acetylneuraminic acid-based affinity matrices for the purification of sialic acid-recognizing proteins

The synthesis of 2-S-(2-aminoethyl) 5-acetamido-3,5-dideoxy-2-thio-D-glycero--D-galacto-2-nonulopyranosidon ic acid (1) has been successfully achieved from the precursors methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-2-S-acetyl-3,5-dideoxy-2-thio-D-glycero--D-galacto-2-nonulopyranosonate (2) and 2-bromo-N-(tert-butoxycarbonyl)-ethylamine (5). Compounds 1 and 2 were coupled, via amino and thioglycosidic linkages, respectively, to epoxy-activated Sepharose 6B. The resultant affinity adsorbents have proved efficient in purifying the sialic acid-recognizing enzyme Vibrio cholerae sialidase, in a one-step process with yields in the order of 60%.     

Functional disomy of Xp22-pter in three males carrying a portion of Xp translocated to Yq

A number of Xp22;Yq11 translocations involving the transposition of Yq material to the distal short arm of the X chromosome have been described. The reciprocal product, i.e. the derivative Y chromosome resulting from the translocation of a portion of Xp to Yq, has never been recovered. We searched for this reciprocal product by performing dosage analysis of Xp22-pter loci in 9 individuals carrying a non-fluorescent Y chromosome. In three mentally retarded and dysmorphic patients, dosage analysis indicated the duplication of Xp22 loci. Use of the highly polymorphic probe CRI-S232 demonstrated the inheritance of paternal Xp-specific alleles in the probands. In situ hybridization, performed in one case, confirmed that 29CL pseudoautosomal sequences were present, in addition to Xpter and Ypter, in the telomeric portion of Yq. To our knowledge, these are the first cases in which the translocation of Xp material to Yq has been demonstrated. The X and Y breakpoints were mapped in the three patients by dosage and deletion analysis. The X breakpoint falls, in the three cases, in a region of Xp22 that is not recognized as sharing sequence similarities with the Y chromosome, thus suggesting that these translocations are not the result of a homologous recombination event.     

Cytosine arabinoside increases the binding of125I-labelled epidermal growth factor and125I-transferrin and enhances the in vitro targeting of human tumour cells with anti-(growth factor receptor) mAb

We report that cytosine arabinoside (Ara-C), a cytosine analogue that at low doses causes phenotypical changes on human leukemia cells in vitro and in vivo, induces growth inhibition of oropharyngeal cancer KB and lung adenocarcinoma A549 cell lines. An increase in the number of epidermal growth factor and transferrin receptors (EGFR, TrfR) is induced by Ara-C on these cells. Maximal EGFR up-regulation occurs 96 h after the beginning of Ara-C exposure while maximal TrfR up-regulation is detected 24 h later. These effects occur without changes in the affinity of EGFR and TrfR for their ligands. Two classes of EGF-binding sites with aK _d of 0.055 nM and 2.3 nM respectively, and one class of transferrin-binding sites with aK _d of about 4 nM are detected on both untreated and Ara-C-treated KB cells. [³H]Thymidine uptake is clearly stimulated on KB cells by nanomolar concentrations of EGF and transferrin, whereas in Ara-C-treated cells [³H]thymidine uptake is not increased by EGF and transferrin under conditions where maximal EGFR and TrfR up-regulation occurs. The enhanced EGF and transferrin binding is paralleled by a twofold increase of in vitro targeting of Ara-C-treated KB and A549 cells with anti-EGFR 108.1 mAb and anti-TrfR OKT9 mAb. We propose that Ara-C could provide a new approach for the improvement of the therapeutic index of anti-EGFR and anti-TrfR immunoconjugates.This work has been supported by the Italian Association for Cancer Research (A.I.R.C.) and by the National Council of Research (C.N.R.) of Italy, contract 92.02274.PF39     

Aurora B expression in post-puberal testicular germ cell tumours

Aurora/Ipl1-related kinases are a conserved family of proteins that are essential for the regulation of chromosome segregation and cytokinesis during mitosis. Aberrant expression and activity of these kinases occur in a wide range of human tumours and have been implicated in mechanisms leading to mitotic spindle aberrations, aneuploidy, and genomic instability. Previous studies of our group have shown that Aurora B expression is restricted to specific germinal cells. In this study, we have evaluated by immunohistochemical analysis Aurora B expression in post-puberal testicular germ cell tumours (22 seminomas, 2 teratomas, 15 embryonal carcinomas, 5 mixed germinal tumours with a prominent yolk sac tumour component and 1 choriocarcinoma). The Aurora B protein expression was detected in all intratubular germ cell tumours, seminomas and embryonal carcinomas analysed but not in teratomas and yolk sac carcinomas. The immunohistochemical data were further confirmed by Western blot analysis. In addition, the kinase Aurora B was vigorously expressed in GC-1 cells line derived from murine spermatogonia. The block of Aurora B function induced by a pharmacological inhibitor significantly reduced the growth of GC-1 cells suggesting that Aurora B is a potential therapeutic target. J. Cell. Physiol. 221: 435–439, 2009. © 2009 Wiley-Liss, Inc.     

The antennal sensilla of the adult of Libellula depressa (Odonata: Libellulidae)

An ultrastructural investigation (SEM, TEM) on the antennal flagellum of the adult of the dragonfly Libellula depressa (Odonata:Libellulidae) revealed sensilla located in pits on the lateral-ventral side of the antenna. These sensilla are represented by sensilla coeloconica and by deeply sunken sensilla. The sensilla coeloconica are innervated by three unbranched dendrites, which enter the peg and show a dendrite sheath ending at the base of the peg. The peg has no socket and its cuticle is irregular with wide pore-like structures at the base of which actual pores are visible. The structure of these coeloconic sensilla is in agreement with that reported for single-walled insect chemoreceptors. The deeply sunken sensilla are represented by two kinds of sensilla styloconica, named type-1 and type-2, located at the bottom of deep cavities appearing as simple openings on the antennal surface. These sensilla are no-pore sensilla with inflexible socket and unbranched dendrites and, notwithstanding their structural differences, share common features typical of thermo/hygroreceptors. The presence of chemoreceptors in adult dragonflies sheds light on evolutionary trends in insect perception; the previously unknown occurrence of thermo/hygroreceptors in dragonflies is very important in view of the reported ability of Odonata to thermoregulate heliothermically.     

Faunistic analysis of fruit flies (Diptera: Tephritidae) in the Northern and Northwestern Regions of Rio de Janeiro State, Brazil

This study aimed to characterize the fruit fly populations in three municipalities of the Northern region and two municipalities of the Northwestern region of Rio de Janeiro State, Brazil, and to evaluate the similarity among their populations. A faunistic analysis was performed from the fruit fly specimens captured in plastic McPhail traps with an aqueous solution of hydrolyzed protein to 5% placed in orchards of guava (Psidium guajava L.) and/or other fruits during 26 months. The total of 3,952 females of 15 species of Anastrepha Schiner and 277 females of Ceratitis capitata (Wied.) was captured. The species richness differed among the municipalities, with the highest value in S?o Francisco do Itabapoana (S = 14), resulting on the highest Shannon-Wiener index (H = 1.27). The equitability was low in the five municipalities due to the dominance of one unique fruit fly species. The predominant species (more frequent, constant and dominant) were Anastrepha obliqua (Macquart) in Campos dos Goytacazes and S?o Francisco do Itabapoana, Anastrepha fraterculus (Wied.) in Cambuci and Itaocara, and Anastrepha sororcula Zucchi in S?o Jo?o da Barra. Fruit fly populations had low diversity index of Margalef (alpha = 0.58 to 1.82). Regarding to fruit fly species composition, the populations in S?o Jo?o da Barra and Cambuci were more similar between each other, composing a distinct group from the populations in Campos dos Goytacazes and Itaocara. These two groups differed quite a lot from the population in S?o Francisco do Itabapoana.     

Overexpression of eNOS prevents the development of renovascular hypertension in mice

Gene therapy has become an important tool for understanding several cardiovascular diseases. In the present study we investigated the effects of endothelial nitric oxide synthase (eNOS) overexpression on renovascular hypertension. Experiments were carried out in C57BL/6 mice randomly assigned to either a two-kidney one-clip (2K1C) hypertension group or a sham-operated group. At the same time surgery was carried out, both 2K1C and sham mice received an intravenous injection of recombinant adenovirus expressing the functional gene eNOS or the reporter gene beta-galactosidase (beta-gal). Fourteen days later, arterial pressure, baroreflex sensitivity, and cardiac sympathetic and parasympathetic tone were evaluated in conscious mice. Measurement of mean arterial pressure showed arterial hypertension in 2K1C-betagal mice compared with sham-betagal mice (121 +/- 3 vs. 96 +/- 2 mm Hg, p < 0.01), which was prevented by eNOS overexpression (2K1C-eNOS 100 +/- 4 vs. sham-eNOS 99 +/- 3 mm Hg). Linear regression analysis of the reflex tachycardia response to sodium nitroprusside-induced hypotension showed that baroreflex sensitivity was significantly attenuated in 2K1C-betagal mice (5.8 +/- 0.5 vs. sham-betagal 8.0 +/- 0.8 beats.min-1 x mm Hg-1, p < 0.05), but this decrease was not prevented by eNOS overexpression (2K1C-eNOS 7.2 +/- 0.5 vs. sham-eNOS 8.8 +/- 0.7 beats x min-1 x mm Hg-1, p < 0.05). The cardiac sympathetic tone was augmented and the vagal tone was reduced in 2K1C-betagal (152 +/- 17 and 45 +/- 12 beats.min-1, respectively) compared with sham-betagal mice (112 +/- 6 and 89 +/- 7 beats.min-1, respectively), and similar results were observed in 2K1C-eNOS mice compared with sham-eNOS. The data indicate that eNOS overexpression was able to prevent the development of 2K1C renovascular hypertension in mice, without affecting other characteristic cardiovascular dysfunctions.     

Organic phase effect in the biphasic bioconversion of substituted naphthalenes by engineered E. coli containing P. fluorescens N3 dioxygenase

Recombinant Escherichia coli based on Pseudomonas fluorescens N3 naphthalene dioxygenase (NDO) was used in two liquid phase bioconversions to produce 1,2-dihydro-1,2-dihydroxy naphthalenes derived from substituted naphthalenes. Five different organic phases (dodecane, silicon oil CR100, dioctyl phthalate, 1-dodecanol, 2-undecanone) were used at different ratios with respect to water and containing different substrate concentrations. The results show different phase effects in terms of both rates and other experimental variables. The differences between substrates are very interesting, showing rate increases from 0.9 to 4 times. The choice of the phase to some extent depends on the substrate, but dodecane shows to be a general effective phase for all the substrates.     

Mycobacterium tuberculosis prevents inflammasome activation

Mycobacterium tuberculosis (Mtb) parasitizes host macrophages and subverts host innate and adaptive immunity. Several cytokines elicited by Mtb are mediators of mycobacterial clearance or are involved in tuberculosis pathology. Surprisingly, interleukin-1beta (IL-1beta), a major proinflammatory cytokine, has not been implicated in host-Mtb interactions. IL-1beta is activated by processing upon assembly of the inflammasome, a specialized inflammatory caspase-activating protein complex. Here, we show that Mtb prevents inflammasome activation and IL-1beta processing. An Mtb gene, zmp1, which encodes a putative Zn(2+) metalloprotease, is required for this process. Infection of macrophages with zmp1-deleted Mtb triggered activation of the inflammasome, resulting in increased IL-1beta secretion, enhanced maturation of Mtb containing phagosomes, improved mycobacterial clearance by macrophages, and lower bacterial burden in the lungs of aerosol-infected mice. Thus, we uncovered a previously masked role for IL-1beta in the control of Mtb and a mycobacterial system that prevents inflammasome and, therefore, IL-1beta activation.