Are 90K/MAC-2BP serum levels correlated with poor prognosis in HCC patients? Preliminary results

In this study we assessed the prognostic significance of 90K/MAC-2BP serum levels in a group of 40 hepatocellular carcinoma patients. This glycoprotein is a new, interesting serum marker that reflects the immune reaction of the host against certain viral infections and tumors such as breast, ovarian and pancreatic cancer. Hepatocellular carcinoma (HCC) is one of the most widespread tumors in the world. AFP is currently the most useful marker for HCC, in spite of its poor diagnostic sensitivity. In this study 40 cirrhotic HCC patients were enrolled. The prevalence of viral hepatic infections in this group was 73% for HCV, 8% for HBV, and 8% for both viruses. Thirteen percent of the patients showed non-virus-related liver damage. 90K serum levels were assayed by an ELISA kit and AFP levels by a chemiluminescent enzyme immunometric system. The overall survival curves were estimated by the Kaplan-Meier method, taking into account age, sex, 90K and AFP serum levels. Statistical analysis showed a highly significant influence on overall survival of age below 70 years and 90K serum levels below the cutoff of 14 ng/mL. Serum AFP (< or = 20 ng/mL) had positive prognostic value only when it was associated with 90K levels (p < 0.02, log-rank).     

Cytogenetics of Manihot esculenta Crantz (cassava) and eight related species

Thirty-nine cultivars of cassava and eight related wild species of Manihot were analyzed in this work for number, morphology and size of chromosomes, prophase condensation pattern and the structure of the interphase nucleus. In four accessions, the chromosome size was measured and in some others, the number of secondary constrictions, meiotic behavior, C-band pattern, CMA/DAPI bands, nucleoli number and the location of 5S and 18S-5.8S-28S rDNA sites were also observed. All investigated accessions showed a similar karyotype with 2n = 36, small metacentric to submetacentric chromosomes. Two pairs of terminal secondary constrictions were observed in the chromosome complement of each accession except Manihot sp. 1, which presented two proximal secondary constrictions. The prophase chromosome condensation pattern was proximal and the interphase nuclei structure was areticulate to semi-reticulate. The meiosis, investigated in seven cultivars and four wild species, was regular, displaying 18 bivalents. C-banding revealed heterochromatin in 9 or 10 chromosomes. The analysis with fluorochromes frequently showed four chromosome pairs with a single CMA+ terminal or subterminal band and a few other chromosomes with DAPI+ unstable bands. Six 45S rDNA sites were revealed by FISH, which seemed to colocalize with six CMA+ bands. Only one chromosome pair presented a 5S rDNA site. The maximum nucleoli number observed per nucleus was also six. These data suggest that all Manihot species present a very similar chromosome complement.     

Physiological diversity and trehalose accumulation in Schizosaccharomyces pombe strains isolated from spontaneous fermentations during the production of the artisanal Brazilian cachaça

Twenty-seven Schizosaccharomyces pombe isolates from seven cacha?a distilleries were tested for maximum temperature of growth and fermentation, osmotolerance, ethanol resistance, invertase production, and trehalose accumulation. Two isolates were selected for studies of trehalose accumulation under heat shock and ethanol stress. The S. pombe isolates were also characterized by RAPD-PCR. The isolates were able to grow and ferment at 41 degrees C, resisted concentrations of 10% ethanol, and grew on 50% glucose medium. Four isolates yielded invertase activity of more than 100 micromol of reducing sugar x mg(-1) x min(-1). The S. pombe isolates were able to accumulate trehalose during stationary phase. Two isolates, strains UFMG-A533 and UFMG-A1000, submitted to a 15 min heat shock, were able to accumulate high trehalose levels. Strain UFMG-A533 had a marked reduction in viability during heat shock, but strain UFMG-A1000 preserved a viability rate of almost 20% after 15 min at 48 degrees C. No clear correlation was observed between trehalose accumulation and cell survival during ethanol stress. Strain UFMG-A1000 had higher trehalose accumulation levels than strain UFMG-A533 under conditions of combined heat treatment and ethanol stress. Molecular analysis showed that some strains are maintained during the whole cacha?a production period; using the RAPD-PCR profiles, it was possible to group the isolates according to their isolation sites.     

Meta-analysis of genetic-linkage analysis of quantitative-trait loci

Meta-analysis is an important tool in linkage analysis. The pooling of results across primary linkage studies allows greater statistical power to detect quantitative-trait loci (QTLs) and more-precise estimation of their genetic effects and, hence, yields conclusions that are stronger relative to those of individual studies. Previous methods for the meta-analysis of linkage studies have been proposed, and, although some methods address the problem of between-study heterogeneity, most methods still require linkage analysis at the same marker or set of markers across studies, whereas others do not result in an estimate of genetic variance. In this study, we present a meta-analytic procedure to evaluate evidence from several studies that report Haseman-Elston statistics for linkage to a QTL at multiple, possibly distinct, markers on a chromosome. This technique accounts for between-study heterogeneity and estimates both the location of the QTL and the magnitude of the genetic effect more precisely than does an individual study. We also provide standard errors for the genetic effect and for the location (in cM) of the QTL, using a resampling method. The approach can be applied under other conditions, provided that the various studies use the same linkage statistic.     

Effects of beta-endorphin and Naloxone on in vitro maturation of bovine oocytes

Bovine cumulus-oocyte complexes (COCs) and mural granulosa cells express the mRNA coding for the micro-opioid receptor. The addition of beta-endorphin (beta-end) to oocytes cultured in hormonally-supplemented in vitro maturation (IVM) medium had no effect on the rates of oocytes reaching the metaphase II (MII) stage, but significantly decreased the maturation rate (P < 0.05) and arrested oocytes at metaphase I (MI) after culture in hormone-free medium (P < 0.001). Naloxone (Nx) reverted this inhibitory effect of beta-end. Moreover, Nx "per se" showed a dose-dependent dual effect. When added at high concentration (10 x (-3) M), it significantly reduced the rate of oocytes in MII (P < 0.001), thus increasing the rate of oocytes arrested in MI. However, Nx added at low concentration (10 x (-8) M) significantly increased oocyte maturation (P < 0.001). High concentration of Nx induced an increase in both intracellular calcium concentration ([Ca(2+)](i)) and in the activity of the mitogen-activated protein kinase (MAPK) also called extracellular-regulated kinase (ERK) in cumulus cells of bovine COCs. Blocking the rise in [Ca(2+)](i) with the calcium chelator acetoxymethylester-derived form of bis (o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM) reversed the Nx-dependent inhibition of meiotic maturation observed at high Nx concentrations. Whereas blocking ERK with the MAPK/ERK kinase (MEK) inhibitor, PD98059, had no effect on this process. Therefore, we concluded that the mocro-opioid receptor, by inducing [Ca(2+)](i) increase, participates in the cumulus-oocyte coupled signaling associated with oocyte maturation.     

MuSK is required for anchoring acetylcholinesterase at the neuromuscular junction

At the neuromuscular junction, acetylcholinesterase (AChE) is mainly present as asymmetric forms in which tetramers of catalytic subunits are associated to a specific collagen, collagen Q (ColQ). The accumulation of the enzyme in the synaptic basal lamina strictly relies on ColQ. This has been shown to be mediated by interaction between ColQ and perlecan, which itself binds dystroglycan. Here, using transfected mutants of ColQ in a ColQ-deficient muscle cell line or COS-7 cells, we report that ColQ clusterizes through a more complex mechanism. This process requires two heparin-binding sites contained in the collagen domain as well as the COOH terminus of ColQ. Cross-linking and immunoprecipitation experiments in Torpedo postsynaptic membranes together with transfection experiments with muscle-specific kinase (MuSK) constructs in MuSK-deficient myotubes or COS-7 cells provide the first evidence that ColQ binds MuSK. Together, our data suggest that a ternary complex containing ColQ, perlecan, and MuSK is required for AChE clustering and support the notion that MuSK dictates AChE synaptic localization at the neuromuscular junction.     

Structural characterization of lignin during Pinus taeda wood treatment with Ceriporiopsis subvermispora

Pinus taeda wood chips were biotreated with Ceriporiopsis subvermispora under solid-state fermentation for periods varying from 15 to 90 days. Milled wood lignins extracted from sound and biotreated wood samples were characterized by wet-chemical and spectroscopic techniques. Treatment of the lignins by derivatization followed by reductive cleavage (DFRC) made it possible to detect DFRC monomers and dimers that are diagnostic of the occurrence of arylglycerol-beta-O-aryl and beta-beta, beta-5, beta-1, and 4-O-5 units in the lignin structure. Quantification of these DFRC products indicated that beta-O-aryl cleavage was a significant route for lignin biodegradation but that beta-beta, beta-5, beta-1, and 4-O-5 linkages were more resistant to the biological attack. The amount of aromatic hydroxyls did not increase with the split of beta-O-4 linkages, suggesting that the beta-O-4 cleavage products remain as quinone-type structures as detected by UV and visible spectroscopy. Nuclear magnetic resonance techniques also indicated the formation of new substructures containing nonoxygenated, saturated aliphatic carbons (CH(2) and CH(3)) in the side chains of lignins extracted from biotreated wood samples.     

Wulfenia carinthiaca Jacq., antioxidant and pharmacological activities

Relative antioxidant activities of a methanolic extract of three phenylpropanoid glycosides and three iridoid glycosides from Wulfenia carinthiaca were evaluated using the Briggs-Rauscher (BR) reaction method. This method is based on the inhibitory effects by antioxidants on oscillations of the BR reaction. The total extract showed a certain antioxidant activity with respect to resorcinol chosen as standard. The three phenylpropanoid glycosides showed a very high relative antioxidant activity while iridoid glycosides had practically no activity. These experimental results were confirmed by empirical calculations based on the BDE (Bond Dissociation Enthalpy) theory. The total phenolic content was also measured for the phenylpropanoid glycosides using the Folin-Ciocalteu reagent. The obtained values as gallic acid equivalents were in perfect agreement with the relative antioxidant activities. From a pharmacological point of view the results obtained demonstrate that the methanolic extract of W. carinthiaca have antinociceptive and antiedematogenic effects in the different models adopted. The plant extract produced a significant inhibition, dose related, of the rat paw edema induced by carrageenin. The anti-inflammatory activity is probably due to the phenylpropanoid compounds present in the plant. The histological sections of paw tissue in animals treated with Wulfenia carinthiaca extract confirmed the anti-inflammatory effects. The results of the antinociceptive assay indicated a significant reduction on the number of abdominal writhes of mice, induced by acetic acid.     

Exogenous sphingosine enters Xenopus laevis embryos grown in petri dishes and it is metabolized

Xenopus embryos of different developmental stages were exposed to 0.1 M [1-³H]sphingosine. Labeled sphingosine was quickly absorbed by Xenopus embryos. The amount of radioactivity absorbed increased with embryo age and appeared to be linearly correlated (R=0.97) to the embryo surface area. About 45% of the total radioactivity associated to the embryos was found in the skin, 22% in the intestine, 15% in the heart, 12% in the liver and 6% in the brain.A portion of [1-³H]sphingosine entered very rapidly the biosynthetic pathway of sphingolipids; after 30 min of incubation, in fact, only a small amount of free radioactive sphingosine could be detected. Sphingomyelin was the main radioactive sphingolipid synthesized; radioactive ceramide, galactosylceramide and lactosylceramide could also be recognized and quantified. On the contrary, the amount of radioactive gangliosides was hardly detectable.A portion of [1-³H]sphinogosine absorbed by Xenopus embryos (30 to 60% depending on the developmental stage) entered the catabolic pathway producing radioactive phosphoethanolamine that was recycled for the biosynthesis of radioactive phosphatidylethanolamine. This phospholipid was produced mainly in the intestine and in the skin, while sphingomyelin was the main radioactive lipid in the heart, liver and brain.