Parasites of ornamental fish imported into Australia

Five commonly imported freshwater ornamental fish: Poecilia reticulata (guppy); Xiphophorus maculatus (platy); Paracheirodon innesi (neon tetra); Paracheirodon axelrodi (cardinal tetra); and Gyrinocheilus aymonieri (sucking catfish), 361 individuals in total, were examined for parasites immediately after being released from quarantine in Australia. Ten parasites species were found: Camallanus cotti; Centrocestus formosanus; Bothriocephalus acheilognathi; Urocleidoides reticulatus; Tetrahymena corlissi; Chilodonella piscicola; Hexamita sp.; Cryptobia sp.; Chloromyxum sp.; and an unidentified larval nematode. Though shipments had come from up to five different exporting companies, parasite prevalence was uniformly high. We suggest that prior to release, fish transported internationally should be checked for high risk pathogens such as Camallanus cotti, B. acheilognathi and Centrocestus formosanus, and treated for common infections such as Hexamita sp., Cryptobia sp. T. corlissi and Chilodonella piscicola to inhibit the spread of disease and enhance the survival of the fish.

NMR imaging of water sorption into poly(hydroxyethyl methacrylate-co-tetrahydrofurfuryl methacrylate)

The diffusion of water into a series of hydroxyethyl methacrylate, HEMA, copolymers with tetrahydrofurfuryl methacrylate, THFMA, has been studied over a range of copolymer compositions using NMR imaging analyses. For polyHEMA the diffusion was found to be consistent with a Fickian model. The mass diffusion coefficient of water in polyHEMA at 37 degreesC was determined from the profiles of the diffusion front to be 1.5 x 10(-11) m(2) s(-1), which is less than the value based upon mass uptake, 2.0 x 10(-11) m(2) s(-1). The profiles of the water diffusion front obtained from the NMR images showed that stress was induced at the interface between the rubbery and glassy regions which led to formation of small cracks in this region of the glassy matrix of polyHEMA and its copolymers with mole fractions of HEMA greater than 0.6. Water was shown to be able to enter these cracks forming water pools. For copolymers of HEMA and THFMA with mole fractions of HEMA less than 0.6 the absence of cracks was attributed to the ability of the THFMA sequences to undergo stress relaxation by creep.

Attachment style and coping resources as predictors of coping strategies in the transition to parenthood

The relations among adult attachment style, coping resources, appraised strain, and coping strategies were examined in a prospective study of married couples having their first child (N = 92). Attachment and coping resources were measured during the second trimester of pregnancy, and parenting strain and coping strategies were assessed when the babies were about 6 weeks old. Results supported a theoretical model proposing that attachment is predictive of coping resources and appraised strain, and that attachment, resources, and strain are predictive of coping strategies. Results also highlighted the complexity of associations among attachment, stress, and coping: Gender differences in mean scores and predictive associations were obtained, and some interactions were found between resources and strain in predicting coping strategies. The findings support the utility of integrating theories of attachment and coping in explaining couples' adjustment to important developmental transitions.

Rearrangement of diflunisal acyl glucuronide into its beta-glucuronidase-resistant isomers facilitates transport through the small intestine to the colon of the rat

Many non-steroidal anti-inflammatory drugs (NSAIDs) which form acyl glucuronide conjugates as major metabolites have shown an antiproliferative effect on colorectal tumors. This study assesses the extent to which rearrangement of an acyl glucuronide metabolite of a model NSAID into beta -glucuronidase-resistant isomers facilitates its passage through the small intestine to reach the colon. Rats were dosed orally with diflunisal (DF), its acyl glucuronide (DAG) and a mixture of rearrangement isomers (iso-DAG) at 10 mg DF equivalents/kg. The parent drug DF appeared in plasma after all doses, with maximum concentrations of 20.5 +/- 2.5, 28.8 +/- 8.3 and 11.0 +/- 1.6 mug DF/ml respectively, obtained at 3.8 +/- 0.3, 3.6 +/- 1.8 and 7.5 +/- 0.9 hr after the DF, DAG and iso-DAG doses respectively. At 48 hr, 16.2 +/- 3.3, 19.8 +/- 0.8 and 42.9 +/- 10.1% of the doses respectively were recovered in feces, with less than or equal to 1% remaining in the intestine. About half of each dose was recovered as DF and metabolites in 48 hr urine: for DF and DAG doses, the majority was in the first 24 hr urine. whereas for iso-DAG doses, recoveries in the first and second 24 hr periods were similar. The results show that hydrolysis of both DAG and iso-DAG, and absorption of liberated DF, occur during passage through the gut, but that these processes occur more slowly and to a lesser degree for iso-DAG. The intrinsic hydrolytic capacities of various intestinal segments (including contents) towards DAG and iso-DAG were obtained by incubating homogenates under saturating concentrations of DAG/iso-DAG at 37 degreesC. Upper small intestine, lower small intestine, caecum and colon released 2400, 3200, 9200 and 22800 mug DF/hr/g tissue plus contents respectively from DAG substrate, and 18, 10, 140 and 120 mug DF/hr/g tissue plus contents respectively from iso-DAG substrate. The much greater resistance of iso-DAG to hydrolysis appears attributable to its resistance to beta -glucuronidases. The data suggest that in rats dosed with DF, DAG excreted in bile would be substantially hydrolysed in the small intestine and liberated DF reabsorbed, but that portion which rearranges to iso-DAG would likely reach the colon. (C) 2001 Elsevier Science Inc. All rights reserved.

Structural effects of lipophilic methotrexate conjugates on model phospholipid biomembranes

Lipophilic conjugates of the antitumor drug methotrexate (MTX) with lipoamino acids (LAAs) have been previously described as a tool to enhance MTX passive entrance into cells, overcoming a form of transport resistance which makes tumour cells insensitive to the antimetabolite. A knowledge of the mechanisms of interaction of such lipophilic derivatives with cell membranes could be useful for planning further lipophilic MTX derivatives with an optimal antitumour activity. To this aim, a calorimetric study was undertaken using a biomembrane model made from synthetic 1,2-dipalmitoyl-glycero-3-phosphocholine (DPPC) multilamellar liposomes. The effects of MTX and conjugates on the phase transition of liposomes were investigated using differential scanning calorimetry. The interaction of pure MTX with the liposomes was limited to the outer part of the phospholipid bilayers, due to the polar nature of the drug. Conversely, its lipophilic conjugates showed a hydrophobic kind of interaction, perturbing the packing order of DPPC bilayers. In particular, a reduction of the enthalpy of transition from the gel to the liquid crystal phase of DPPC membranes was observed. Such an effect was related to the structure and mole fraction of the conjugates in the liposomes. The antitumour activity of MTX conjugates was evaluated against cultures of a CCRF-CEM human leukemic T-cell line and a related MTX resistant sub-line. The in vitro cell growth inhibitory activity was higher for bis(tetradecyl) conjugates than for both the other shorter- and longer-chain derivatives. The biological effectiveness of the various MTX derivatives correlated very well with the thermotropic effects observed on the phase transition of DPPC biomembranes. (C), 2001 Elsevier Science B.V All rights reserved.

Laser cooling of a solid from ambient temperature

A 250 mum diameter fibre of ytterbium-doped ZBLAN was cooled by 13 K from room temperature. The cooling was performed in vacuum to limit the thermal load on the fibre. 0.85 W of laser light at 1015 nm was coupled into the fibre. The ytterbium ions absorbed this light, and the excited atoms thermalized phononically and on average emitted light at a wavelength of 996 nm. Since the quantum efficiency of the transition was high, this resulted in a net loss of energy from the glass, producing net bulk cooling.

Receptor-mediated endocytosis of Neisseria gonorrhoeae into primary human urethral epithelial cells: the role of the asialoglycoprotein receptor

Urethral epithelial cells are invaded by Neisseria gonorrhoeae during gonococcal infection in men. To understand further the mechanisms of gonococcal entry into host cells, we used the primary human urethral epithelial cells (PHUECs) tissue culture system recently developed by our laboratory. These studies showed that human asialoglycoprotein receptor (ASGP-R) and the terminal lactosamine of lacto-N-neotetraose-expressing gonococcal lipooligosaccharide (LOS) play an important role in invasion of PHUECs. Microscopy studies showed that ASGP-R traffics to the cell surface after gonococcal challenge. Co-localization of ASGP-R with gonococci was observed. As ASGP-R-mediated endocytosis is clathrin dependent, clathrin localization in PHUECs was examined after infection. Infected PHUECs showed increased clathrin recruitment and co-localization of clathrin and gonococci. Preincubating PHUECs in 0.3 M sucrose or monodansylcadaverine (MDC), which both inhibit clathrin-coated pit formation, resulted in decreased invasion. N. gonorrhoeae strain 1291 produces a single LOS glycoform that terminates with Gal(beta1-4)Glc-Nac(beta1-3)Gal(beta1-4)Glc (lacto-N-neotetraose). Invasion assays showed that strain 1291 invades significantly more than four isogenic mutants expressing truncated LOS. Sialylation of strain 1291 LOS inhibited invasion significantly. Preincubation of PHUECs in asialofetuin (ASF), an ASGP-R ligand, significantly reduced invasion. A dose-response reduction in invasion was observed in PHUECs preincubated with increasing concentrations of NaOH-deacylated 1291 LOS. These studies indicated that an interaction between lacto-N-neotetraose-terminal LOS and ASGP-R allows gonococcal entry into PHUECs.

A total-evidence phylogeny of ticks provides insights into the evolution of life cycles and biogeography

We inferred the phylogeny of 33 species of ticks from the subfamilies Rhipicephalinae and Hyalomminae from analyses of nuclear and mitochondrial DNA and morphology. We used nucleotide sequences from 12S rRNA, cytochrome c oxidase I, internal transcribed spacer 2 of the nuclear rRNA, and 18S rRNA. Nucleotide sequences and morphology were analyzed separately and together in a total-evidence analysis. Analyses of the five partitions together (3303 characters) gave the best-resolved and the best-supported hypothesis so far for the phylogeny of ticks in the Rhipicephalinae and Hyalomminae, despite the fact that some partitions did not have data for some taxa. However, most of the hidden conflict (lower support in the total-evidence analyses compared to that in the individual analyses) was found in those partitions that had taxa without data. The partitions with complete taxonomic sampling had more hidden support (higher support in the total-evidence analyses compared to that in the separate-partition analyses) than hidden conflict. Mapping of geographic origins of ticks onto our phylogeny indicates an African origin for the Rhipicephalinae sensu lato (i.e., including Hyalomma spp.), the Rhipicephalus-Boophilus lineage, the Dermacentor-Anocentor lineage, and the Rhipicephalus-Booophilus-Nosomma-Hyalomma-Rhipicentor lineage. The Nosomma-Hyalomma lineage appears to have evolved in Asia. Our total-evidence phylogeny indicates that (i) the genus Rhipicephalus is paraphyletic with respect to the genus Boophilus, (ii) the genus Dermacentor is paraphyletic with respect to the genus Anocentor, and (iii) some subgenera of the genera Hyalomma and Rhipicephalus are paraphyletic with respect to other subgenera in these genera. Study of the Rhipicephalinae and Hyalomminae over the last 7 years has shown that analyses of individual datasets (e.g., one gene or morphology) seldom resolve many phylogenetic relationships, but analyses of more than one dataset can generate well-resolved phylogenies for these ticks. (C) 2001 Academic Press.

Glass transition in Australian honeys

Differential scanning calorimetry (DSC) was used to study the glass transition in 10 Australian honeys by scanning at 10 degrees Cmin(-1) from -130 to 50 degreesC after annealing at -50 degreesC. The honeys had moisture contents 14.9 to 18.0%, seven were from Eucalyptus species. The glass transition temperatures (T-g) ranged from -46 degrees to -38 degreesC and were significantly (p

Onset of the Henry constant for supercritical adsorption into carbonaceous porous materials

The Henry constant is commonly used as a measure of how strong an adsorbate is attracted towards a solid surface and is regarded as one of the fundamental parameters in adsorption studies. Having a sound basis in thermodynamics, the Henry Law is often used as a criterion to evaluate the validity of adsorption isotherm equations. However, the application of the Henry Law for microporous materials, especially microporous activated carbon, remains questionable. It is the aim of this paper to examine the Henry Law behavior of supercritical adsorbates in carbonaceous pores of different sizes, and to define the conditions for the Henry Law to be applicable for carbonaceous adsorbents.

Proteomic analysis reveals that 14-3-3 sigma in downregulated in human breast cancer cells

The class of molecular chaperones known as 14-3-3 is involved in the control of cellular growth by virtue of its apparent regulation of various signaling pathways, including the Raf/mitogen-activated protein kinase pathway. In breast cancer cells, the sigma form of 14-3-3 has been shown to interact with cyclin-dependent kinases and to control the rate of entry into mitosis. To test for a direct role for 14-3-3 in breast epithelial cell neoplasia, me have quantitated 14-3-3 protein levels using a proteomic approach based on two-dimensional electrophoresis and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF). We show here that 14-3-3 sigma protein is strongly down-regulated in the prototypic breast cancer cell lines MCF-7 and MDA-MB-231 and in primary breast carcinomas as compared with normal breast epithelial cells. In contrast, levels of the alpha, beta, delta, or zeta isoforms of 14-3-3 mere the same in both normal and transformed cells. The data support the idea that 14-3-3 sigma is involved in the neoplastic transition of breast epithelial cells by virtue of its role as a tumor suppressor; as such, it may constitute a robust marker with clinical efficacy for this pathology.