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Parthenogenesis is a form of asexual reproduction by which embryos develop from unfertilized eggs. Parthenogenesis occurs in reptiles; however, it is not yet known to occur in the widespread elapid snakes (Elapidae), which include well-known taxa such as cobras, mambas, taipans and sea snakes. Here, we describe the production of viable parthenogens in two species of Australo-Papuan elapids with divergent reproductive modes: the oviparous coastal/Papuan taipan (Oxyuranus scutellatus) and the viviparous southern death adder (Acanthophis antarcticus). Analyses of nuclear SNP data excluded paternity for putative fathers and convincingly demonstrated asexual reproduction, thus representing the first evidence of facultative parthenogenesis in Elapidae. Our finding has broad implications for understanding the evolution of reproductive diversity in snakes, as well as managing the conservation of genetic diversity in wild and captive populations.

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AIMS/HYPOTHESIS: This study used proteomics and biochemical approaches to identify novel glucose-regulated proteins and to unveil their role in pancreatic beta cell function. Translationally controlled tumour protein (TCTP) was identified to be one such protein, and further investigations into its function and regulation were carried out. METHODS: Global protein profiling of beta cell homogenates following glucose stimulation was performed using two-dimensional gel electrophoresis. Proteins were identified by mass spectroscopy analysis. Immunoblotting was used to investigate alterations in TCTP protein levels in response to glucose stimulation or cell stress induced by palmitate. To investigate the biological function of TCTP, immunolocalisation, gene knockdown and overexpression of Tctp (also known as Tpt1) were performed. Apoptosis was measured in Tctp knockdown or Tctp-overexpressing cells. Glucose-stimulated insulin secretion was carried out in Tctp knockdown cells. RESULTS: TCTP was identified as a novel glucose-regulated protein, the level of which is increased at stimulatory glucose concentration. Glucose also induced TCTP dephosphorylation and its partial translocation to the mitochondria and the nucleus. TCTP protein levels were downregulated in response to cell stress induced by palmitate or thapsigargin treatments. Gene knockdown by small interfering RNA led to increased apoptosis, whereas overproduction of TCTP prevented palmitate-induced cell death. CONCLUSIONS/INTERPRETATION: Regulation of TCTP protein levels by glucose is likely to be an important cyto-protective mechanism for pancreatic beta cells against damage caused by hyperglycaemia. In contrast, high concentration of palmitate causes cell stress, reduction in TCTP levels and consequently reduced cell viability. Our results imply that TCTP levels influence the sensitivity of beta cells to apoptosis.

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The viviparous sea snakes (Hydrophiini) are by far the most successful living marine reptiles, with ∼ 60 species that comprise a prominent component of shallow-water marine ecosystems throughout the Indo-West Pacific. Phylogenetically nested within the ∼ 100 species of terrestrial Australo-Melanesian elapids (Hydrophiinae), molecular timescales suggest that the Hydrophiini are also very young, perhaps only ∼ 8-13 Myr old. Here, we use likelihood-based analyses of combined phylogenetic and taxonomic data for Hydrophiinae to show that the initial invasion of marine habitats was not accompanied by elevated diversification rates. Rather, a dramatic three to six-fold increase in diversification rates occurred at least 3-5 Myr after this transition, in a single nested clade: the Hydrophis group accounts for ∼ 80% of species richness in Hydrophiini and ∼ 35% of species richness in (terrestrial and marine) Hydrophiinae. Furthermore, other co-distributed lineages of viviparous sea snakes (and marine Laticauda, Acrochordus and homalopsid snakes) are not especially species rich. Invasion of the oceans has not (by itself) accelerated diversification in Hydrophiini; novelties characterizing the Hydrophis group alone must have contributed to its evolutionary and ecological success.

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One of the most prolific radiations of venomous snakes, the Australo-Melanesian Hydrophiinae includes approximately 100 species of Australasian terrestrial elapids plus all approximately 60 species of viviparous sea snakes. Here, we estimate hydrophiine relationships based on a large data set comprising 5800 bp drawn from seven genes (mitochondrial: ND4, cytb, 12S, 16S; nuclear: rag1, cmos, myh). These data were analysed using parsimony, likelihood and Bayesian methods to better resolve hydrophiine phylogeny and provide a timescale for the terrestrial and marine radiations. Among oviparous forms, Cacophis, Furina and Demansia are basal to other Australian elapids (core oxyuranines). The Melanesian Toxicocalamus and Aspidomorphus group with Demansia, indicating multiple dispersal events between New Guinea and Australia. Oxyuranus and Pseudonaja form a robust clade. The small burrowing taxa form two separate clades, one consisting of Vermicella and Neelaps calanotus, and the other including Simoselaps, Brachyurophis and Neelaps bimaculatus. The viviparous terrestrial elapids form three separate groups: Acanthophis, the Rhinoplocephalus group and the Notechis-Hemiaspis group. True sea snakes (Hydrophiini) are robustly united with the Notechis-Hemiaspis group. Many of the retrieved groupings are consistent with previous molecular and morphological analyses, but the polyphyly of the viviparous and burrowing groups, and of Neelaps, are novel results. Bayesian relaxed clock analyses indicate very recent divergences: the approximately 160 species of the core Australian radiation (including sea snakes) arose within the last 10 Myr, with most inter-generic splits dating to between 10 and 6 Ma. The Hydrophis sea snake lineage is an exceptionally rapid radiation, with > 40 species evolving within the last 5 Myr.

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Müllerian mimicry, in which toxic species gain mutual protection from shared warning signals, is poorly understood in vertebrates, reflecting a paucity of examples. Indirect evidence for mimicry is found if monophyletic species or clades show parallel geographic variation in warning patterns. Here, we evaluate a hypothesis of Müllerian mimicry for the pitvipers in Southeast Asia using a phylogeny derived from DNA sequences from four combined mitochondrial regions. Mantel matrix correlation tests show that conspicuous red colour pattern elements are significantly associated with sympatric and parapatric populations in four genera. To our knowledge, this represents the first evidence of a Müllerian mimetic radiation in vipers. The putative mimetic patterns are rarely found in females. This appears paradoxical in light of the Müllerian prediction of monomorphism, but may be explained by divergent selection pressures on the sexes, which have different behaviours. We suggest that biased predation on active males causes selection for protective warning coloration, whereas crypsis is favoured in relatively sedentary females.

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We analyse molecular and phenotypic evolution in a group of taxonomically problematic Indomalayan pitvipers, the Trimeresurus sumatranus group. Mitochondrial DNA sequencing provides a well-resolved phylogeny, with each species representing a distinct lineage. Multivariate morphological analysis reveals a high level of phenotypic differentiation, which is congruent between the sexes but does not reflect phylogenetic history. An adaptive explanation for the observed pattern of differentiation is supported by independent contrasts analysis, which shows significant correlations between current ecology and the characters that most account for the variation between taxa, including those that are presently used to identify the species. Reduced precipitation and altitude, and increased temperature, are correlated with higher numbers of scales on the head, body and tail. It is hypothesized that scale number plays an important role in heat and water exchange by influencing the area of exposed of interstitial skin, and that colour pattern variation reflects selection pressures involving camouflage and thermoregulation. Ecological convergence in traits used for classification is found to have important implications for species identification where taxa are distributed over varying environments.

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Patients with pulmonary tuberculosis develop pleural effusions with a high protein content. Pleural mesothelial adherens junctions promote mesothelial cell-cell adhesion and contribute to pleural integrity. In the present study we have investigated the effect of mycobacterium (BCG) on mesothelial cell adherens junction proteins and pleural permeability. BCG enhanced pleural mesothelial cell (PMC) release of vascular endothelial growth factor (VEGF), and decreased electrical resistance across the PMC monolayer. Neutralizing antibodies to VEGF significantly restored the drop in PMC electrical resistance caused by BCG. BCG infection down regulated beta-catenin (adherens junction protein) expression and caused increased permeability across confluent mesothelial monolayer. Our results suggest that in TB pleurisy, mycobacteria cause VEGF release from mesothelial cells and leads to protein exudation by altering mesothelial adherens junction proteins.

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Migration of polymorphonuclear neutrophils (PMNL) from the vascular compartment into the pleural space occurs rapidly during the development of parapneumonic effusions. This study investigated the polarized secretion of interleukin (IL)-8 in activated pleural mesothelial cells (PMC) and the migration of PMNL across resting, activated PMC monolayers. Results show that PMC produce IL-8 in a polar manner. When PMC were stimulated with Staphylococcus aureus or IL-1beta at the basal or at the apical surface, significantly (P< .05) more IL-8 was released toward the apical surface. This polarized production of IL-8 was confirmed by in situ hybridization. PMNL migration was higher from the basilar to apical than from the apical to basilar surface of PMC. Neutralizing antibodies against IL-8 and intercellular adhesion molecule (ICAM)-1 significantly (P< .001) blocked PMNL migration across activated monolayers. Thus, during pleural inflammation, PMC regulate the influx of PMNL into the pleural space by polar production of IL-8 and expression of ICAM-1.

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The pharmacokinetics of chloramphenicol (CAP) and total chloramphenicol succinate (CAPS) were studied in eight hospitalized adult patients with normal renal and hepatic function receiving intravenous chloramphenicol sodium succinate therapy. The steady-state peak concentrations of CAP (8.4-26.0 micrograms/ml) occurred at an average of 18.0 min (range 5.4-40.2) after cessation of the chloramphenicol sodium succinate infusion. Unhydrolyzed CAPS prodrug, representing 26.0 +/- 7.0% of the dose, was recovered unchanged in the urine indicating that the bioavailability of CAP from a dose of intravenous chloramphenicol succinate is not complete. A pharmacokinetic model was developed for simultaneous fitting of CAP and CAPS plasma concentration data. Pharmacokinetic parameters determined by simultaneous fitting were: V, 0.81 +/- 0.18 liters/kg; t1/2, 3.20 +/- 1.02 hr; CLB, 3.21 +/- 1.27 ml/min/kg for chloramphenicol; and V, 0.38 +/- 0.13 liters/kg; t1/2, 0.57 +/- 0.12 hr; CLB, 7.72 +/- 1.87 ml/min/kg for total chloramphenicol succinate.

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We describe a 44-year-old man who recently received a cadaveric renal transplant and had a relapse of Legionnaires' disease after an appropriate course of therapy. The relapse occurred within two weeks after completion of a three-week course of therapy with erythromycin stearate. A transbronchial biopsy specimen was positive for Legionella pneumophila by direct immunofluorescence, although the Dieterle silver impregnation stain was negative. The patient responded to a repeated course of erythromycin for an additional 21 days, and no further sequelae or relapses have been noted. The importance of early rapid diagnostic modalities in the immunocompromised patient is emphasized, and the need to consider the possibility of relapse after effective therapy is warranted.

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A late infection caused by Bacteroides fragilis in a prosthesis knee joint is presented. The patient's underlying disease may have predisposed her to this organism.

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