New monogeneans from the bathydemersal southern African endemic catshark,Holohalaelurus regani (Gilchrist, 1922)

The catshark genus Holohalaelurus Fowler is currently represented by five species distributed off the southern and eastern parts of the African coast. Very few parasitological records exist for any of these five species, representing a significant knowledge gap. We report the first monogenean species from the bathydemersal species Holohalaelurus regani (Gilchrist): a new species of Microbothriidae Price, 1936, Leptomicrobothrium holohalaelure n. sp. from the dorsal skin surface, and a new species of Hexabothriidae Price, 1942 representing a new genus, Scyliorhinocotyle narvaezae n. gen., n. sp., from the gill lamellae. Both monogenean records represent the first for any member of the catshark genus Holohalaelurus. Previously we focused on the identification of monogenean taxa of emerging veterinary importance for public aquaria. We now begin a focused effort to document a generally unexplored monogenean biodiversity from diverse marine habitats off South Africa.

     

Saikosaponin-d,a novel SERCA inhibitor,induces autophagic cell death in apoptosis-defective cells

Autophagy is an important cellular process that controls cells in a normal homeostatic state by recycling nutrients to maintain cellular energy levels for cell survival via the turnover of proteins and damaged organelles. However, persistent activation of autophagy can lead to excessive depletion of cellular organelles and essential proteins, leading to caspase-independent autophagic cell death. As such, inducing cell death through this autophagic mechanism could be an alternative approach to the treatment of cancers. Recently, we have identified a novel autophagic inducer, saikosaponin-d (Ssd), from a medicinal plant that induces autophagy in various types of cancer cells through the formation of autophagosomes as measured by GFP-LC3 puncta formation. By computational virtual docking analysis, biochemical assays and advanced live-cell imaging techniques, Ssd was shown to increase cytosolic calcium level via direct inhibition of sarcoplasmic/endoplasmic reticulum Ca²⁺ ATPase pump, leading to autophagy induction through the activation of the Ca²⁺/calmodulin-dependent kinase kinase–AMP-activated protein kinase–mammalian target of rapamycin pathway. In addition, Ssd treatment causes the disruption of calcium homeostasis, which induces endoplasmic reticulum stress as well as the unfolded protein responses pathway. Ssd also proved to be a potent cytotoxic agent in apoptosis-defective or apoptosis-resistant mouse embryonic fibroblast cells, which either lack caspases 3, 7 or 8 or had the Bax-Bak double knockout. These results provide a detailed understanding of the mechanism of action of Ssd, as a novel autophagic inducer, which has the potential of being developed into an anti-cancer agent for targeting apoptosis-resistant cancer cells.     

On Cannabis indica,Indian hemp

Background: The South Aegean Volcanic Arc (SAVA), one of the most notable geological structures of the Mediterranean Sea, is floristically well known. Nevertheless, the factors that contribute to shaping the plant species richness of the SAVA remain unclear.

Aims: To investigate the factors that affect plant species richness and identify plant diversity hotspots in the SAVA and other central Aegean islands.

Methods: We used stepwise multiple regression to test the relationship between a number of environmental factors and plant species richness in the SAVA, as well as the residuals from the species–area linear regressions of native, Greek and Cycladian endemic taxa as indicators of relative species richness.

Results: The area was confirmed to be the most powerful single explanatory variable of island species richness, while geodiversity, maximum elevation and mean annual precipitation explained a large proportion of variance for almost all the species richness measures. Anafi, Amorgos and Folegandros were found to be endemic plant diversity hotspots.

Conclusions: We have demonstrated that geodiversity is an important factor in shaping plant species diversity in the Cyclades, while mean annual precipitation, human population density and maximum elevation were significant predictors of the Greek endemics present in the Cyclades. Finally, Anafi was found to be a plant diversity hotspot in the South Aegean Sea.     

<Emphasis Type="Italic">Anoplodiscus</Emphasis> Sonsino, 1890 (Monogenea: Anoplodiscidae): a new Australian species,and the first African record from South African hosts

Species of Anoplodiscus Sonsino, 1890 were previously only known from host members of Sparidae. A new species, Anoplodiscus hutsonae n. sp. is proposed for museum specimens originally collected from species of Scolopsis Cuvier (Nemipteridae) off Heron Island and Lizard Island, Australia. Additionally, Anoplodiscus tai Ogawa, 1994 is synonymised with Anoplodiscus cirrusspiralis Roubal, Armitage & Rohde, 1983 due to a lack of support for differential characters, and Anoplodiscus richiardii is considered a species inquirenda. Anoplodiscus cirrusspiralis causes visible lesions on the skin and fins of its host, and may also contribute to poor food conversion rates in sparid aquaculture. Anoplodiscus cirrusspiralis has been recorded from cultured sparids in Australia, Japan, South Africa, and South Korea, and was implicated as a disease agent in fish from the former two countries. However, the discovery of A. cirrusspiralis on Chrysoblephus gibbiceps (Valenciennes), Ch. laticeps (Valenciennes) and Cymatoceps nasutus (Castelnau) in South Africa, ?Pagrus major (Temminck & Schlegel) in South Korea, and P. auratus (Forster) in Australia, New Zealand and Japan suggests that this species may have a wide distribution and low host-specificity within the Sparidae. In South Africa, A. cirrusspiralis was first encountered on a morbid C. nasutus and Ch. gibbiceps from two public aquaria in 2009 (Two Oceans Aquarium, Cape Town and uShaka Sea World, Durban, respectively). Additional material was collected from C. laticeps kept at an abalone farm in Hermanus that originated from Struisbaai on the South African south coast. Anoplodiscus cirrusspiralis is redescribed from the South African specimens. This is the first record of a member of Anoplodiscidae Tagliani, 1912 from Africa.     

Development and preliminary evaluation of a real-time PCR assay for Halioticida noduliformans in abalone tissues

Abalone Haliotis midae exhibiting typical clinical signs of tubercle mycosis were discovered in South African culture facilities in 2006, posing a significant threat to the industry. The fungus responsible for the outbreak was identified as a Peronosporomycete, Halioticida noduliformans. Currently, histopathology and gross observation are used to diagnose this disease, but these 2 methods are neither rapid nor sensitive enough to provide accurate and reliable diagnosis. Real-time quantitative PCR (qPCR) is a rapid and reliable method for the detection and quantification of a variety of pathogens, so therefore we aimed to develop a qPCR assay for species-specific detection and quantification of H. noduliformans. Effective extraction of H. noduliformans genomic DNA from laboratory grown cultures, as well as from spiked abalone tissues, was accomplished by grinding samples using a pellet pestle followed by heat lysis in the presence of Chelax-100 beads. A set of oligonucleotide primers was designed to specifically amplify H. noduliformans DNA in the large subunit (LSU) rRNA gene, and tested for cross-reactivity to DNA extracted from related and non-related fungi isolated from seaweeds, crustaceans and healthy abalone; no cross-amplification was detected. When performing PCR assays in an abalone tissue matrix, an environment designed to be a non-sterile simulation of environmental conditions, no amplification occurred in the negative controls. The qPCR assay sensitivity was determined to be approximately 0.28 pg of fungal DNA (~2.3 spores) in a 25 μl reaction volume. Our qPCR technique will be useful for monitoring and quantifying H. noduliformans for the surveillance and management of abalone tubercle mycosis in South Africa.     

Cytoplasmic filaments and cellular wound healing in amoeba proteus

The flexibility and self-healing properties of animal cell surface membranes are well known. These properties have been best exploited in various micrurgical studies on living cells (2, 3), especially in amoebae (7, 20). During nuclear transplantation in amoebae, the hole in the membrane through which a nucleus passes can have a diameter of 20-30 μm, and yet such holes are quickly sealed, although some cytoplasm usually escapes during the transfer. While enucleating amoebae in previous studies, we found that if a very small portion of a nucleus was pushed through the membrane and exposed to the external medium, the amoeba expelled such a nucleus on its own accord. When this happened, a new membrane appeared to form around the embedded portion of the nucleus and no visible loss of cytoplasm occurred during nuclear extrusion. In the present study, we examined amoebae that were at different stages of expelling partially exposed nuclei, to follow the sequence of events during the apparent new membrane formation. Unexpectedly, we found that a new membrane is not formed around the nucleus from inside but a hole is sealed primarily by a constriction of the existing membrane, and that cytoplasmic filaments are responsible for the prevention of the loss of cytoplasm.     

Fgf-dependent otic induction requires competence provided by Foxi1 and Dlx3b

Background  

The inner ear arises from a specialized set of cells, the otic placode, that forms at the lateral edge of the neural plate adjacent to the hindbrain. Previous studies indicated that fibroblast growth factors (Fgfs) are required for otic induction; in zebrafish, loss of both Fgf3 and Fgf8 results in total ablation of otic tissue. Furthermore, gain-of-function studies suggested that Fgf signaling is not only necessary but also sufficient for otic induction, although the amount of induced ectopic otic tissue reported after misexpression of fgf3 or fgf8 varies among different studies. We previously suggested that Foxi1 and Dlx3b may provide competence to form the ear because loss of both foxi1 and dlx3b results in ablation of all otic tissue even in the presence of a fully functional Fgf signaling pathway.     

Which population level environmental factors are associated with asthma,rhinoconjunctivitis and eczema? Review of the ecological analyses of ISAAC Phase One

The International Study of Asthma and Allergies in Childhood (ISAAC) Phase One showed large worldwide variations in the prevalence of symptoms of asthma, rhinoconjunctivitis and eczema, up to 10 to 20 fold between countries. Ecological analyses were undertaken with ISAAC Phase One data to explore factors that may have contributed to these variations, and are summarised and reviewed here.In ISAAC Phase One the prevalence of symptoms in the past 12 months of asthma, rhinoconjunctivitis and eczema were estimated from studies in 463,801 children aged 13 - 14 years in 155 centres in 56 countries, and in 257,800 children aged 6-7 years in 91 centres in 38 countries. Ecological analyses were undertaken between symptom prevalence and the following: Gross National Product per capita (GNP), food intake, immunisation rates, tuberculosis notifications, climatic factors, tobacco consumption, pollen, antibiotic sales, paracetamol sales, and outdoor air pollution.Symptom prevalence of all three conditions was positively associated with GNP, trans fatty acids, paracetamol, and women smoking, and inversely associated with food of plant origin, pollen, immunisations, tuberculosis notifications, air pollution, and men smoking. The magnitude of these associations was small, but consistent in direction between conditions. There were mixed associations of climate and antibiotic sales with symptom prevalence.The potential causality of these associations warrant further investigation. Factors which prevent the development of these conditions, or where there is an absence of a positive correlation at a population level may be as important from the policy viewpoint as a focus on the positive risk factors. Interventions based on small associations may have the potential for a large public health benefit.     

Time-dependent changes to lipids and antioxidants in plasma and aortas of apolipoprotein E knockout mice.

Oxidation of lipoproteins is thought to be an early event in atherogenesis. To evaluate whether aortic lipoprotein lipid (per)oxidation contributes to atherosclerosis, we investigated the time-dependent changes to lipids and antioxidants in plasma and aortas of apolipoprotein E gene knockout (apoE-/-) mice receiving a high fat diet, and compared these changes with lesion development. Circulating buoyant lipoproteins and associated cholesterol (C), cholesteryl esters (CE), and alpha-tocopherol (alpha-TOH) increased within 1 month then remained largely constant up to 6 months. Coenzyme Q (CoQ) remained unchanged for the first 3 months and increased marginally after 6 months. With increasing duration of the diet, plasma lipids showed an increased propensity to undergo peroxyl radical-induced (per)oxidation. Absolute concentrations of aortic C, hydroperoxides and hydroxides of CE (CE-O(O)H) and alpha-TOH increased gradually while aortic CE increased more markedly with changes to cholesteryl linoleate being most pronounced. Aortic CoQ remained largely unchanged. Overall, the extent of aortic CE (per)oxidation remained low (相似文献