Pancreatic carboxypeptidases: activities in zinc-deficient rats

Zinc deficiency in rats caused decrease in the activity of pancreatic carboxypeptidase A, but it had no effect on pancreatic carboxypepti dase B and liver alcohol dehydrogenase. The observed reduction of enzymic activity may be related to the poor utilization of feed that occurs in zincdeficient rats.     

Fungal immunomodulatory protein from Flammulina velutipes induces interferon-gamma production through p38 mitogen-activated protein kinase signaling pathway

FIP-fve is a fungal immunomodulatory protein purified from Flammulina velutipes, an edible golden needle mushroom thought to possess potent immunomodulatory properties. When examined for its effects on lymphocytes, FIP-fve exhibited potent mitogenic effects on human peripheral blood lymphocytes, inducing G1/G0 to S phase proliferation. T cells activated by FIP-fve show significant production and secretion of interferon-gamma (IFN-gamma) associated with intercellular adhesion molecule 1 expression but low detectable levels of interleukin-4 in vitro or in vivo. However, SB203580, the p38 mitogen-activated protein kinase (p38 MAPK) inhibitor, can fully abolish the production of IFN-gamma induced by FIP-fve. At the same time, SB203580 only partially prevents the lymphocytes from progressing from G1 to S phase of the cell cycle. These findings demonstrate that FIP-fve is a potent T-cell activator, mediating its effects via cytokine regulation of p38 MAPK. The immunoprophylatic effects of FIP-fve in Th2-mediated allergic anaphylaxis are believed to be associated with the ability of FIP-fve to enhance activation of IFN-gamma-releasing Th1 cells.     

Inhibitory activities of semicarbazide-sensitive amine oxidase and angiotensin converting enzyme of pectin hydroxamic acid

Solutions of 100 mL of 1% commercial pectin each with a different degree of esterification (DE), DE94, DE65, and DE25, were reacted with 100 mL of 2 M alkaline hydroxylamine (pH 12.0) at room temperature for 4 or 18 h. These pectin hydroxamic acids (PHAs; DE94T4, DE94T18, DE65T4, and DE25T4) were used to test the inhibitory activities against semicarbazide-sensitive amine oxidase (SSAO) and angiotensin-converting enzyme (ACE). Compared to different DE pectins (DE94, DE65, and DE25), the PHAs of DE94T4, DE94T18, DE65T4, and DE25T4 showed different inhibition activities against SSAO or ACE. Commercial pectins with different DE values showed negligible SSAO or ACE inhibitions. The order of SSAO inhibition was DE65T4 > DE94T18 approximately DE25T4 > DE94T4. However, the order of ACE inhibition was DE94T4 > DE94T18 > DE65T4 > DE25T4. The SSAO activity staining or ACE-hydrolyzed products on TLC chromatogram also confirmed the inhibitory activities of PHAs against SSAO or ACE.     

The influence of carboxymethylcellulose on growth, digestion, gastric emptying time and body composition of tilapia

Carboxymethylcellulose (CMC) was incorporated into each of two experimental diets at one of four levels (2, 6, 10 and 14%). Each of the eight diets was fed to male tilapia hybrids (Oreochromis niloticus × O. aureus) for 9 weeks. The experiment was conducted in a closed, filtered and recirculated rearing system. The fish were fed the appropriate diets at a rate of 3% of body weight per day, 2 times a day, 6 days a week. The water temperature was maintained at 26°C. Tilapia fed diets containing, 6, 10 and 14% CMC showed significantly poorer (P<0.05) feed conversion rates than fish fed diets containing 2% CMC. The dry matter digestion coefficients of the diets did not differ significantly but generally declined as CMC level increased. Gastric emptying times decreased as the level of inclusion of CMC in the diets increased. Crude protein content and ash content of fish were similar in all dietary groups. Fish fed diets containing 6, 10 and 14% CMC had significantly lower (P<0.05) lipid content than fish fed diets with 2% CMC.     

Engulfed pathogen-induced apoptosis in haemocytes of giant freshwater prawn, Macrobrachium rosenbergii

Haemocytes of the giant freshwater prawn, Macrobrachium rosenbergii, were investigated for the induction of apoptosis after phagocytosis of pathogenic yeasts, bacteria and non-pathogenic latex beads in vitro. Isolated haemocytes of M. rosenbergii were cultured at a ratio of 1:50 haemocytes to pathogen with the yeast Debaryomyces hansenii, the bacteria Aeromonas hydrophila or Enterococcus faecium, or with latex beads at 25 degrees C for 2 h, followed by washing to remove free particles. At least 200 haemocytes were counted to determine the phagocytosis rate, and the results showed that haemocytes engulfed latex beads at a higher rate than the aquatic pathogens. By transmission electron microscopy, the yeast- or bacterium-engulfing haemocytes displayed morphological changes characteristic of apoptosis, including formation of cytoplasmic vacuoles, chromatin condensation and fragmentation of nuclei. This pathogen-induced apoptosis was further confirmed by DNA laddering and TUNEL (terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick-end-labelling) assays. Neither haemocytes treated with latex beads nor uninfected haemocytes (control group) showed signs of apoptosis after 48 h in culture.     

Purification and glycosylation analysis of an acidic pectin methylesterase in jelly fig (Ficus awkeotsang) achenes

An acidic pectin methylesterase (PME) is responsible for the gelation of water extract from jelly fig (Ficus awkeotasang) achenes. A new, fast and efficient, method has been developed to purify this acidic PME. The method includes preparing jelly curd by traditional hand washing, extracting proteins from the curd, and separating PME by anion-exchanger. The purified PME exists as a monomer of 38 kDa determined by gel filtration, and exerts enzymatic activity over a broad pH range, particularly in acidic environments where most known PME enzymes from various species are inactivated. Chemical staining and enzymatic cleavage suggest that the jelly fig PME is an N-linked glycoprotein. Fluorophore-assisted carbohydrate electrophoresis reveals that the polysaccharide of this glycoprotein putatively consists of 22 hexoses including 16 mannose, 4 N-acetylglucosamine, and 2 galactose residues.     

Prognosis of acute kidney injury in dogs using RIFLE (Risk, Injury, Failure, Loss and End-stage renal failure)-like criteria

A retrospective case-series study evaluated the prognosis of 853 dogs with acute kidney injury (AKI) based on the RIFLE (Risk, Injury, Failure, Loss and End-stage renal failure) criteria, derived from human medicine. The 30-day mortality of dogs with AKI in each class was found to be 23.8 per cent (40 of 168) dogs for Risk, 41.0 per cent (107 of 261) dogs for Injury and 78.5 per cent (333 of 424) dogs for Failure. Using the dogs in the Risk class as the reference, the mortality of dogs in either the Injury or Failure class was significantly higher than that of dogs in the Risk class (P<0.05). The longest median survival time was observed in the Risk class (nine days) and the shortest median survival time was observed in the Failure class (three days). Using a multiple logistic regression model, a new score that simultaneously considered RIFLE class, diarrhoea status and serum phosphorus level was calculated to predict prognosis. Evaluation using the area under the receiver-operating characteristic curve (AUROC) indicated that the new scoring method (AUROC 0.80) was a better prognostic indicator than using RIFLE criteria alone (AUROC 0.73).     

A comparative study of the interaction of Bartonella henselae strains with human endothelial cells

Bartonella henselae can cause a wide range of clinical outcomes and may lead to severe disease, especially in patients with acquired immunodeficiency syndrome. It is well-known that B. henselae-induced cell proliferation is mediated by anti-apoptotic activity; however, the detailed mechanism is still unclear. In this study, the cellular responses of endothelial cells after infection with four B. henselae strains were compared and protein candidates that may be involved in the interaction between cells and bacteria were determined. The Houston-1 strain elicited the fastest response in terms of stimulating endothelial cell proliferation, and the JK-40 strain had the strongest ability to induce cell proliferation. By Western blot analysis, it was demonstrated that B. henselae-induced cell proliferation involved the mitochondria intrinsic apoptotic pathway. In addition, the adhesion abilities of the U-4 and JK-40 strains were much greater than those of the Houston-1 and JK-47 strains; however, the ability of Houston-1 to invade host cells was high. By two-dimensional gel electrophoresis analysis, it was found that succinyl-CoA synthetase subunit beta, phage-related protein, and ATP synthase subunit alpha might be involved in the invasion process. The expression of superoxide dismutase [Cu-Zn] precursor increased with infection time for all four strains but was significantly higher in the Houston-1 strain, which may increase the competitive advantage of Houston-1 in terms of survival in host cells and render it successful in invading host cells and stimulating cell proliferation. Our data suggest that the interaction of B. henselae and endothelial cells differed between strains, and the results indicated possible candidate proteins that may play a role in the pathogenesis of B. henselae infection.     

New bioactive orange pigments with yellow fluorescence from Monascus-fermented dioscorea

Red mold dioscorea (RMD) is a fermented product of Monascus purpureus NTU 568 using dioscorea as culture substrate. To investigate the bioactive components of RMD, six orange pigments including four new azaphilones with yellow fluorescence, monapilol A-D (1-4), and known monascorubrin (5) and rubropunctatin (6) were isolated and characterized. Structural elucidation of new isolates was based on nuclear magnetic resonance ((1)H NMR, (13)C NMR, COSY, HMQC, and HMBC) and other spectroscopic analyses. The structures of monapilols (1-4) were similar to those of monascorubrin (5) and rubropunctatin (6); however, the hydroxyl group (8-OH) in compounds 1-4 substituted for the C-8 carbonyl in compounds 5 and 6. Biological evaluation indicated that compounds 1-4 inhibited nitric oxide (NO) production on lipopolysaccharide-stimulated RAW 264.7 cells. Compounds 1-4 also exhibited antiproliferative activities against human laryngeal carcinoma (HEp-2) and human colon adenocarinoma (WiDr).