A New Species of Tiger Pleco Panaqolus (Siluriformes: Loricariidae) from the Xingu Basin,Brazil

Panaqolus tankei is described from the Xingu River, Brazil. The new species is diagnosed from P. albomaculatus, P. dentex, P. nix, P. nocturnus, and P. koko by its color pattern consisting of dark and light diagonal bars on the body and bands on the fins (vs. body and fins without bars or bands); from P. albivermis, P. maccus, and P. purusiensis by the width of the dark bars being more or less the same of the light bars (vs. dark bars at least two or three times wider than light bars) and from P. changae by the absence of vermiculation on the head (vs. vermiculation present on head). The new species differs from P. gnomus by the orientation of the bars from posterodorsal to anteroventral direction (vs. anterodorsal to posteroventral direction), and from P. claustellifer by the orientation of the bands in the dorsal fin that are not parallel to the margin (vs. parallel to the margin). The barcoding region (COI) was sequenced for the new species, sequences were deposited in GenBank and were compared with congeners from other drainages. With regard to the current construction of a hydroelectric power plant (a so-called mega dam) in the Xingu River, herewith we increase knowledge of the river Xingu’s ichthyofauna and, thus improve the assessment of the impacts of that construction on the river.     

The VITRO Score (Von Willebrand Factor Antigen/Thrombocyte Ratio) as a New Marker for Clinically Significant Portal Hypertension in Comparison to Other Non-Invasive Parameters of Fibrosis Including ELF Test

Background

Clinically significant portal hypertension (CSPH), defined as hepatic venous pressure gradient (HVPG) ≥10 mmHg, causes major complications. HVPG is not always available, so a non-invasive tool to diagnose CSPH would be useful. VWF-Ag can be used to diagnose. Using the VITRO score (the VWF-Ag/platelet ratio) instead of VWF-Ag itself improves the diagnostic accuracy of detecting cirrhosis/ fibrosis in HCV patients.

Aim

This study tested the diagnostic accuracy of VITRO score detecting CSPH compared to HVPG measurement.

Methods

All patients underwent HVPG testing and were categorised as CSPH or no CSPH. The following patient data were determined: CPS, D’Amico stage, VITRO score, APRI and transient elastography (TE).

Results

The analysis included 236 patients; 170 (72%) were male, and the median age was 57.9 (35.2–76.3; 95% CI). Disease aetiology included ALD (39.4%), HCV (23.4%), NASH (12.3%), other (8.1%) and unknown (11.9%). The CPS showed 140 patients (59.3%) with CPS A; 56 (23.7%) with CPS B; and 18 (7.6%) with CPS C. 136 patients (57.6%) had compensated and 100 (42.4%) had decompensated cirrhosis; 83.9% had HVPG ≥10 mmHg. The VWF-Ag and the VITRO score increased significantly with worsening HVPG categories (P<0.0001). ROC analysis was performed for the detection of CSPH and showed AUC values of 0.92 for TE, 0.86 for VITRO score, 0.79 for VWF-Ag, 0.68 for ELF and 0.62 for APRI.

Conclusion

The VITRO score is an easy way to diagnose CSPH independently of CPS in routine clinical work and may improve the management of patients with cirrhosis.     

Intestinal Microbiota and Microbial Metabolites Are Changed in a Pig Model Fed a High-Fat/Low-Fiber or a Low-Fat/High-Fiber Diet

The intestinal microbiota and its metabolites appear to be an important factor for gastrointestinal function and health. However, research is still needed to further elaborate potential relationships between nutrition, gut microbiota and host’s health by means of a suitable animal model. The present study examined the effect of two different diets on microbial composition and activity by using the pig as a model for humans. Eight pigs were equally allotted to two treatments, either fed a low-fat/high-fiber (LF), or a high-fat/low-fiber (HF) diet for 7 weeks. Feces were sampled at day 7 of every experimental week. Diet effects on fecal microbiota were assessed using quantitative real-time PCR, DNA fingerprinting and metaproteomics. Furthermore, fecal short-chain fatty acid (SCFA) profiles and ammonia concentrations were determined. Gene copy numbers of lactobacilli, bifidobacteria (P<0.001) and Faecalibacterium prausnitzii (P<0.05) were higher in the LF pigs, while Enterobacteriaceae were more abundant in the HF pigs (P<0.001). Higher numbers of proteins affiliated to Enterobacteriaceae were also present in the HF samples. Proteins for polysaccharide breakdown did almost exclusively originate from Prevotellaceae. Total and individual fecal SCFA concentrations were higher for pigs of the LF treatment (P<0.05), whereas fecal ammonia concentrations did not differ between treatments (P>0.05). Results provide evidence that beginning from the start of the experiment, the LF diet stimulated beneficial bacteria and SCFA production, especially butyrate (P<0.05), while the HF diet fostered those bacterial groups which have been associated with a negative impact on health conditions. These findings correspond to results in humans and might strengthen the hypothesis that the response of the porcine gut microbiota to a specific dietary modulation is in support of using the pig as suitable animal model for humans to assess diet-gut-microbiota interactions.Data are available via ProteomeXchange with identifier PXD003447.     

Influence of plasmalogen deficiency on membrane fluidity of human skin fibroblasts: a fluorescence anisotropy study

The influence of plasmalogen deficiency on membrane lipid mobility was determined by measuring fluorescence anisotropy of trimethylammoniumdiphenylhexatriene (TMA-DPH) and diphenylhexatrienylpropanoylhydrazylstachyose (glyco-DPH) inserted in the plasma membranes of human skin fibroblasts deficient in plasmalogens. The cells used were from patients affected with cerebrohepatorenal (Zellweger) syndrome (CHRS) or rhizomelic chondrodysplasia punctata. Their plasmalogen content (0-5% of total phospholipid) is significantly reduced compared with that of control cells from healthy donors (13-15% of total phospholipid) or of CHRS fibroblasts supplemented with the plasmalogen precursor, hexadecylglycerol. Plasmalogen-deficient cells consistently showed lower fluorescence anisotropies of membrane-bound DPH fluorophores corresponding to higher membrane lipid mobilities as compared to controls. However, very similar lipid mobilities were found for sonicated aqueous dispersions of phospholipids extracted either from CHRS or control cells. Therefore, the differences observed with living cells are not due to differences in the overall physical properties of the membrane lipid constituents. Other phenomena such as lipid asymmetry and/or plasmalogen-protein interactions may be responsible for the effects observed in the biomembranes.     

Peptide synthesis with immobilized carboxypeptidase Y

Enzymatic peptide synthesis was investigated using carboxypeptidase Y immobilized with glutaraldehyde on 10 mum microparticulate amino-silica. Carboxypeptidase Y was immobilized with 98.5% recovery of active enzyme to yield the immobilized enzyme having 0.55 units esterase activity/mg amino-silica support. The stability of the immobilized enzyme was examined as a function of pH, temperature, and reactant concentrations. Immobilized Carboxypeptidase Y was used in stirred batch and recirculating packed-bed reactors for peptide synthesis. Packed-bed reactors (40 x 4.6 mm, 60 x 4.6 mm) were used to catalyze the synthesis of 170 mg N-benzoyl-L-arginyl-L-methioninamide, 380 mg N-benzoyl-L-arginyl-L-methionyl-L-leucinamide, and 200 mg N-benzoyl-L-arginyl-L-methionyl-L-leucyl-L-phenylalaninamide in 8, 3, and 1 hour, respectively, as intermediates in the synthesis of L-methionyl-L-leucyl-L-phenylalanine. No inactivation of the immobilized enzyme was observed during the course of the reactions. The N-benzoyl-L-arginyl group served to increase the water solubility of the peptides and was removed by immobilized trypsin at the end of synthesis to obtain the final product. While the first two syntheses were conducted with aqueous reaction mixtures, the synthesis of N-benzoyl-L-arginyl-L-methionyl-L-leucyl-L-phenylalaninamide was carried out in a reaction mixture containing dimethylformamide to avoid precipitation of the product. HPLC and amino acid analysis confirmed the high purity and amino acid composition of the final product.     

Immunoreactive galanin-like material in magnocellular hypothalamoneurohypophysial neurones of the rat

Summary Immunoreactive galanin-like material was recently shown to co-exist with vasopressin in parvocellular and magnocellular perikarya of the paraventricular nucleus in the anterior hypothalamus of the rat (Melander et al. 1986). Since this distribution pattern differed from our observation of oxytocin-associated galanin-like immunoreactivity (LI) in the neurohypophysis, we compared in series of 0.5-m thick sections the localisation of galanin-LI with the localisation of oxytocin and vasopressin/dynorphin in the hypothalamus, the median eminence and the neurohypophysis. In the oxytocin system, galanin-LI was intense in oxytocin varicosities of the neurohypophysis. Oxytocin perikarya of the hypothalamic supraoptic and paraventricular nuclei exhibited galanin-LI only after intraventricular injection of colchicine and when sections were treated with trypsin prior to application of the antibody. In the vasopressin/dynorphin system galanin-LI was intense in hypothalamic perikarya after colchicine injection and in neurohypophysial varicosities after treatment of the sections with trypsin. In these neurones, galanin-LI was absent or weak in all elements when treatments with colchicine or trypsin were omitted. Galanin-LI in the neurohypophysis was not co-localised with the numerous fine endings showing GABA-LI. These observations indicate that galanin-like material coexists with vasopressin and oxytocin in the respective magnocellular neurones, although not always in an immunoreactive form.     

Atrial natriuretic factor-like immunoreactivity in spinal cord and in primary sensory neurons of spinal and trigeminal ganglia of guinea-pig: correlation with tachykinin immunoreactivity*

Summary Atrial natriuretic factor (ANF) is a cardiac hormone with various functions in body homeostasis. It is also processed in the brain and in the peripheral nervous system where it appears to play a role as a neuromodulator. Little is known about the presence of ANF throughout the spinal cord of the guinea-pig. We therefore examined the distribution of ANF and its possible interrelation with primary sensory afferents in this species. Using enzyme- and fluorescence-immunohistochemistry on deparaffinized sections, ANF-like immunoreactivity was found to be present in nerve fibers in laminae I/II of the spinal cord and in neurons of spinal and trigeminal ganglia. Tachykinins and ANF coexisted in very few fibers of the spinal cord but did not coexist in primary sensory spinal or trigeminal neurons. Our results indicate that spinal ANF-immunoreactive fibers are of dual origin, primary sensory and non-primary sensory. The possibly heterogeneous source of the non-primary sensory ANF, its possible coexistence with other co-transmitters and functional implications are discussed.Preliminary aspects of this study have been reported at the 2nd World Congress of Neuroscience in Budapest (Weihe et al. 1987) and at the Versammlung der Anatomischen Gesellschaft in Zürich (Nohr et al. 1989)     

Preparation of a novel psoralen containing deoxyadenosine building block for the facile solid phase synthesis of psoralen-modified oligonucleotides for a sequence specific crosslink to a given target sequence.

4,5',8-Trimethylpsoralen was attached to the C8-position of deoxyadenosine via a sulfur atom and a five carbon atom linker. The modified deoxyadenosine was then converted to a protected phosphoramidite and used as unusual as a building block for solid phase oligodeoxyribonucleotide synthesis. The efficiency of the photoreaction of a psoralen-modified oligonucleotide to a complementary matrix strand reached more than 90% within a 1 hour irradiation time at a wavelength of 345 nm.     

Accurate mapping of the Escherichia coli pepD gene by sequence analysis of its 5′ flanking region

Summary A cloned DNA fragment, carrying the gene for peptidase D (pepD) of Escherichia coli, was partially sequenced. By purification of peptidase D and sequence determination of an amino-terminal oligopeptide the reading frame of the pepD gene, starting with a GTG initiator codon, was unambiguously identified.An overlap of the established nucleotide sequence with the previously sequenced 5 flanking region of the gpt gene allowed the exact distance between pepD and gpt to be calculated. The two genes are pointing towards each other and are separated by 260 bp. A search for open reading frames (ORFs) and the analysis of possible codon usage in the intercistronic region indicate the absence of an additional gene (lpcA) between pepD and gpt.     

Immunochemical quantification of Cu/Zn superoxide dismutase in prenatal diagnosis of Down's syndrome

Summary Cu/Zn Superoxide dismutase (SOD) was quantified by enzyme immunoassay for prenatal diagnosis of Down's syndrome. Overall, 154 samples of amniotic fluid, 72 samples of amniotic cells and 31 samples of chorionic tissue were investigated. Due to the large biological variance of the SOD concentrations in normal pregnancies (range for amniotic fluid 10.5–154.9, for amniotic cells 40.0–338.8, and for chorionic tissue 132.2–649.5 g SOD/g protein) the cases of Down's syndrome detected by karyotype analysis were not reliably identified by Cu/Zn SOD quantification. As in erythrocytes obtained from patients with Down's syndrome, a trisomy 21 was easily and accurately detected in the erythrocytes from very small quantities (about 50 l) of umbilical blood. The SOD concentrations in normal cases (n = 40) varied between 11.4 and 17.3 and in the cases of trisomy 21, as confirmed by karyotyping (n = 4), between 22.5 and 23.2ng/one million cells. SOD quantification in fetal erythrocyte is a helpful additional method in prenatal Down syndrome diagnosis under certain conditions, which are discussed.