A murine model for the study of the impact ofAspergillus fumigatus inoculation on the foeto-placental unit

The mycotoxin cyclopiazonic acid (CPA) is a potential contaminant of processed foods, grain and poultry. Twelve male Sprague-Dawley rats were given oral doses of 0, 0.2, 0.6, 2.0 or 4.0 mg CPA/kg body weight/day for 13 consecutive weeks to study its potential subchronic toxicity. No dose-related mortality or morbidity occurred. General appearance, behavior, body weight gain and food consumption of all groups were similar. CPA had no definite adverse hematologic or serum chemistry effects, although serum creatinine concentrations of rats given 2.0 and 4.0 mg CPA/kg BW were increased after seven and 13 weeks. Mild to focally moderate acute inflammation of the lamina propria and submucosa of the gastric epithelium was found in animals given 0.6 mg CPA/kg BW. No other dose-related microscopic lesions were found. Ultrastructural examination of the livers revealed subtle disruption of the cisternal pattern of the endoplasmic reticulum with ribosomal detachment in animals receiving 4.0, but not 2.0, mg CPA/kg BW. These data suggest that the toxic effects in rats of repeated, daily oral exposure to CPA may be less than previously reported. The possible relationship between toxicity and CPA epimerization is considered.     

Synthesis and physicochemical properties of oligonucleotides built with either alpha-L or beta-L nucleotides units and covalently linked to an acridine derivative.

Modified deoxynucleosides 2'-deoxy-beta-L-uridine, beta-L-thymidine, alpha-L-thymidine, 2'-deoxy-beta-L-adenosine and 2'-deoxy-alpha-L-adenosine were synthesized and assembled as homooligomers, respectively: octa-beta-L-deoxyuridylates, octa beta-L and alpha-L-thymidylates and tetra beta-L and alpha-L-deoxyadenylates. These unnatural oligomers were then substituted with an acridine derivative. The binding studies of these modified oligonucleotides with D-ribo- and D-deoxyribopolynucleotides were carried out by absorption spectroscopy. While beta-L-d(Up)8m5Acr, beta-L-(Tp)8m5Acr, alpha-L-(Tp)8m5Acr did not interact with poly(rA) and poly(dA), beta-L-d(Ap)4m5Acr and alpha-L-d(Ap)4m5Acr did form double and triple helices with poly(rU) and poly(dT), respectively. Their stability towards nuclease digestion was studied through comparison with that of octa-beta-D-thymidylate and tetra beta-D-deoxyadenylate covalently linked to an acridine derivative. One endonuclease (nuclease P1 from Penicillium citrinum) and two exonucleases (a 3'-exonuclease from Crotalus durissus venom and a 5'-exonuclease extracted from calf thymus) were employed. beta-L- and alpha-L-oligomers demonstrate a high resistance toward nuclease digestion.     

Induction of pregnancy-associated murine protein-1 in dwarf mice by human growth hormone

Pregnancy-associated murine protein-1 (PAMP-1) could not be detected in peripheral blood of female dwarf mice (genotype dw/dw of the DW strain). By contrast the normal size females of the DW strain (genotypes +/+ and +/dw) had PAMP-1 serum levels of 18.9 AU +/- 15.7 AU/ml. Following administration of biosynthetic human growth hormone (hGH) every 2 h for 52 h PAMP-1 was detected in all dwarf females at concentrations of 16.0 AU +/- 3.3 AU/ml. The albumin levels in the circulation of DW females of normal size were significantly higher (P less than 0.05) than those of DW dwarfs, and the hGH administration did not change the serum albumin levels. The present experiment adds weight to the suggestion that the PAMP-1 serum level is regulated by GH.     

IMPRINTING EFFECTS OF THREE AMINO ACIDS (ALANINE,LYSINE AND GLYCINE) AND THEIR OLIGOPEPTIDES INTETRAHYMENA PYRIFORMIS. DATA FROM THE HORMONE AND HORMONE RECEPTOR EVOLUTION

Hormonal imprinting takes place at the first encounter of the hormone and receptor, and results in a changed binding capacity and reaction of the cell and its progeny generations. The imprinting effect of three amino acids and their oligopeptides is studied using fluorescent-labelled peptides. Glycine and lysine could provoke positive imprinting (increased binding in the progeny generations) for their own peptides, but alanine could not. Mostly positive imprinting was provoked by glycine and lysine peptides for their own peptides of different chain length. The optimal chain length provoking self-imprinting was four for glycine, two for lysine and three for alanine. Except in this case, alanine was neutral or provoked mostly negative imprinting. After reaching the optimal chain length, there is a decline in binding. Evolutionary conclusions are discussed.     

Conservation evaluation of nine Hong Kong mangals

A comparative analysis of the conservation value of nine Hong Kong mangals spread across Hong Kong has been undertaken. The analysis is based on both biological and socio-economic attributes. Biological attributes used in the analysis include plant species richness, benthic and arboreal gastropod species richness, occurrence of rare species within each site, and site representativeness. A review of the past and present development and development plans around and within each site has been undertaken to assess the comparative degree of hazard to each mangal. The drastic decline of mangal habitats throughout Hong Kong highlights the need for conservation of what remains today. Priorities and strategies for conservation of these nine mangals are discussed with particular emphasis on the preservation of biodiversity and the management of these habitats as education and research sites.Department of Applied Biology & Chemical Technology, Hong Kong Polytechnic     

Plasmin and the regulation of tissue-type plasminogen activator biosynthesis in human endothelial cells.

Plasmin inhibited the biosynthesis of tissue-type plasminogen activator (tPA) antigen by human umbilical vein endothelial cells (HUVEC) in a dose-dependent manner. The amount of tPA antigen found in the 24-h conditioned medium of cells treated with 100 nM plasmin for 1 h was 20-30% of that in the control group. However, in contrast to tPA, such treatment led to a 3-fold increase in plasminogen activator inhibitor (PAI) activity, whereas the amount of PAI type 1 antigen was unchanged. The effects of plasmin on HUVEC were binding- and catalytic activity-dependent and were specifically blocked by epsilon-aminocaproic acid. Microplasmin, which has no kringle domains, was less effective in reducing tPA antigen biosynthesis or enhancing PAI activity in HUVEC. Kringle domains of plasmin affected neither tPA antigen nor PAI activity of the cells. Other proteases including chymotrypsin, trypsin, and collagenase at comparable concentrations did not have a significant effect on the biosynthesis of tPA antigen or PAI activity of HUVEC. Thrombin stimulated the biosynthesis of tPA and PAI-1 antigens by HUVEC. Thrombin also stimulated an increase in the protein kinase activity in HUVEC, whereas plasmin inhibited the protein kinase activity of the cells. It is possible that plasmin regulates the biosynthesis of tPA in HUVEC through the signal transduction pathway involving protein kinase.     

Pregnancy-associated murine protein-1 (PAMP-1) in wild rodents.

The presence of pregnancy-associated murine protein-1 (PAMP-1) in a number of wild rodent species was examined using tandem crossed immunoelectrophoresis and anti PAMP-1 antisera raised in rabbits. PAMP-1 is a protein present in female laboratory mice and rats; analogues were readily detected in the following species: Musculus domesticus, M. musculus, Apodemus sylvaticus, A. agrarius, A. flavicollis, and Microtus arvalus. Immunologically, cross-reacting proteins could not be detected in the laboratory hamster and laboratory guinea pig. Maternal PAMP-1 serum levels were recorded throughout pregnancy in the two species of house mouse: M. domesticus and M. musculus. Both proteins exhibited maximum concentration at day 11 of gestation. During early pregnancy, M. domesticus females had significantly higher serum levels than those of M. musculus females.     

Characterization of Polar and Non‐Polar Compounds of House Edible Bird's Nest (EBN) from Johor,Malaysia

This work investigated the polar (PC: protein, amino acid and metabolite) and non‐polar (NPC: fatty acid) compounds and bioactivity characteristics of the EBN harvested from the state of Johor in Malaysia. The electrophoretic gels exhibited 15 protein bands (16–173 kD) with unique protein profile. Amino acids analysis by AccQ?Tag method revealed 18 types of amino acids in EBN. Metabolite profiling was performed using High‐Performance Liquid Chromatography coupled with Quadrupole Time‐of‐Flight Mass Spectrometer (HPLC‐QTOF/MS) technique and a total of 54 compounds belonging to different groups were detected and identified. These findings help to uncover the relation of therapeutic activity of EBN. The EBN was further extracted with AcOEt and BuOH. The AcOEt extract was fractionated into three fractions (F₁?F₃), and the high triglyceride content in F₂ was verified by gC‐FID. The three groups of fatty acids discovered in EBN are 48.43 % of poly‐unsaturated (PUFA), 25.35 % of saturated fatty acids (SFA) and 24.74 % of mono‐unsaturated fat (MUFA). This is the first time to report results ofEBN, BuOH, and AcOEt extracts and of fraction F₂ (TEBN) on their analysis for their antioxidant activities by DPPH, ABTS and catalase assay and for their paraoxonase and anti‐tyrosinase activities. The results showed that TEBN exhibited the significant bioactivity in all assays. These findings suggest that TEBN is a good source for natural bioactive compounds in promoting body vigor. Current work widened the content of EBN especially on the triglyceride and also marked the content of specific location (Johor, Malaysia) of EBN origin.     

Intense photon emission induced by fracture of γ–irradiated Dy‐, Tm‐, Sm‐ and Mn‐doped CaSO4 single crystals

When an γ‐irradiated Dy‐, Tm‐, Sm‐ or Mn‐doped CaSO₄ crystal is impulsively deformed, two peaks appear in the ML intensity versus time curve, whereby the first ML peak is found in the deformation region and the second in the post‐deformation region of the crystals. In this study, intensities I_m1 and I_m2 corresponding to first and second ML peaks, respectively, increased linearly with an impact velocity v₀ of the piston used to deform the crystals, and times t_m1 and t_m2 corresponding to the first and second ML peaks, respectively, decreased with impact velocity. Total ML intensity initially increased with impact velocity and then reached a saturation value for higher values of impact velocity. ML intensity increased with increasing γ‐doses and size of crystals. Results showed that the electric field produced as a result of charging of newly‐created surfaces caused tunneling of electrons to the valence band of the hole‐trapping centres. The free holes generated moved in the valence band and their subsequent recombination with electron trapping centres released energy, thereby resulting in excitation of luminescent centres. Copyright © 2012 John Wiley & Sons, Ltd.