Lithium release from ß-tricalcium phosphate inducing cementogenic and osteogenic differentiation for both hPDLCs and hBMSCs

It is accepted that the accelerated differentiation of tissue cells on bioactive materials is of great importance to regenerate the lost tissues. It was previously reported that lithium (Li) ions could enhance the in vitro proliferation and differentiation of retinoblastoma cells and endometrium epithelia by activating the Wnt canonical signalling pathway. It is interesting to incorporate Li ions into bioactive ceramics, such as β-tricalcium phosphate (Li-β-TCP), in order to stimulate both osteogenic and cementogenic differentiation of different stem cells for the regeneration of bone/periodontal tissues. Therefore, the aim of this study was to investigate the interactions of human periodontal ligament cells (hPDLCs) and human bone marrow stromal cells (hBMSCs) with Li-β-TCP bioceramic bulks and their ionic extracts, and further explore the osteogenic and cementogenic stimulation of Li-β-TCP bioceramics and the possible molecular mechanisms. The results showed that Li-β-TCP bioceramic disks supported the cell attachment and proliferation, and significantly enhanced bone/cementum-related gene expression, Wnt canonical signalling pathway activation for both hPDLCs and hBMSCs, compared to conventional β-TCP bioceramic disks without Li. The release of Li from Li-β-TCP powders could significantly promote the bone/cementum-related gene expression for both hPDLCs and hBMSCs compared to pure β-TCP extracts without Li release. Our results suggest that the combination of Li with β-TCP bioceramics may be a promising method to enhance bone/cementum regeneration as Li-β-TCP possesses excellent in vitro osteogenic and cementogenic stimulation properties by inducing bone/cementum-related gene expression in both hPDLCs and hBMSCs.

Osteoimmunomodulatory properties of magnesium scaffolds coated with β-tricalcium phosphate

The osteoimmunomodulatory property of bone biomaterials is a vital property determining the in vivo fate of the implants. Endowing bone biomaterials with favorable osteoimmunomodulatory properties is of great importance in triggering desired immune response and thus supports the bone healing process. Magnesium (Mg) has been recognized as a revolutionary metal for applications in orthopedics due to it being biodegradable, biocompatible, and having osteoconductive properties. However, Mg's high rate of degradation leads to an excessive inflammatory response and this has restricted its application in bone tissue engineering. In this study, β-tricalcium phosphate (β-TCP) was used to coat Mg scaffolds in an effort to modulate the detrimental osteoimmunomodulatory properties of Mg scaffolds, due to the reported favorable osteoimmunomodulatory properties of β-TCP. It was noted that macrophages switched to the M2 extreme phenotype in response to the Mg-β-TCP scaffolds, which could be due to the inhibition of the toll like receptor (TLR) signaling pathway. VEGF and BMP2 were significantly upregulated in the macrophages exposed to Mg-β-TCP scaffolds, indicating pro-osteogenic properties of macrophages in β-TCP modified Mg scaffolds. This was further demonstrated by the macrophage-mediated osteogenic differentiation of bone marrow stromal cells (BMSCs). When BMSCs were stimulated by conditioned medium from macrophages cultured on Mg-β-TCP scaffolds, osteogenic differentiation of BMSCs was significantly enhanced; whereas osteoclastogenesis was inhibited, as indicated by the downregualtion of MCSF, TRAP and inhibition of the RANKL/RANK system. These findings suggest that β-TCP coating of Mg scaffolds can modulate the scaffold's osteoimmunomodulatory properties, shift the immune microenvironment towards one that favors osteogenesis over osteoclastogenesis. Endowing bone biomaterials with favorable osteoimmunomodulatory properties can be a highly valuable strategy for the development or modification of advanced bone biomaterials.

Ultra sensitive label free surface enhanced Raman spectroscopy method for the detection of biomolecules

We present a proof of concept for a novel nanosensor for the detection of ultra-trace amounts of bio-active molecules in complex matrices. The nanosensor is comprised of gold nanoparticles with an ultra-thin silica shell and antibody surface attachment, which allows for the immobilization and direct detection of bio-active molecules by surface enhanced Raman spectroscopy (SERS) without requiring a Raman label. The ultra-thin passive layer (~1.3 nm thickness) prevents competing molecules from binding non-selectively to the gold surface without compromising the signal enhancement. The antibodies attached on the surface of the nanoparticles selectively bind to the target molecule with high affinity. The interaction between the nanosensor and the target analyte result in conformational rearrangements of the antibody binding sites, leading to significant changes in the surface enhanced Raman spectra of the nanoparticles when compared to the spectra of the un-reacted nanoparticles. Nanosensors of this design targeting the bio-active compounds erythropoietin and caffeine were able to detect ultra-trace amounts the analyte to the lower quantification limits of 3.5×10−13 M and 1×10−9 M, respectively.

Onset of Mediterranean outflow into the North Atlantic

Sediments cored along the southwestern Iberian margin during Integrated Ocean Drilling Program Expedition 339 provide constraints on Mediterranean Outflow Water (MOW) circulation patterns from the Pliocene epoch to the present day. After the Strait of Gibraltar opened (5.33 million years ago), a limited volume of MOW entered the Atlantic. Depositional hiatuses indicate erosion by bottom currents related to higher volumes of MOW circulating into the North Atlantic, beginning in the late Pliocene. The hiatuses coincide with regional tectonic events and changes in global thermohaline circulation (THC). This suggests that MOW influenced Atlantic Meridional Overturning Circulation (AMOC), THC, and climatic shifts by contributing a component of warm, saline water to northern latitudes while in turn being influenced by plate tectonics.

Defining the spatiotemporal surveillance space for alien species’ invasions using approximate Bayesian computation

The spatiotemporal dynamics of an alien species invasion across a real landscape are typically complex. While surveillance is an essential part of a management response, planning surveillance in space and time present a difficult challenge due to this complexity. We show here a method for determining the highest probability sites for occupancy across a landscape at an arbitrary point in the future, based on occupancy data from a single slice in time. We apply to the method to the invasion of Giant Hogweed, a serious weed in the Czech republic and throughout Europe.

Epigenetic mechanisms mediating vulnerability and resilience to psychiatric disorders

The impact that stressful encounters have upon long-lasting behavioural phenotypes is varied. Whereas a significant proportion of the population will develop "stress-related" conditions such as post-traumatic stress disorder or depression in later life, the majority are considered "resilient" and are able to cope with stress and avoid such psychopathologies. The reason for this heterogeneity is undoubtedly multi-factorial, involving a complex interplay between genetic and environmental factors. Both genes and environment are of critical importance when it comes to developmental processes, and it appears that subtle differences in either of these may be responsible for altering developmental trajectories that confer vulnerability or resilience. At the molecular level, developmental processes are regulated by epigenetic mechanisms, with recent clinical and pre-clinical data obtained by ourselves and others suggesting that epigenetic differences in various regions of the brain are associated with a range of psychiatric disorders, including many that are stress-related. Here we provide an overview of how these epigenetic differences, and hence susceptibility to psychiatric disorders, might arise through exposure to stress-related factors during critical periods of development.

Loss of neuronatin expression is associated with promoter hypermethylation in pituitary adenoma

The imprinted gene, neuronatin (NNAT), is one of the most abundant transcripts in the pituitary and is thought to be involved in the development and maturation of this gland. In a recent whole-genome approach, exploiting a pituitary tumour cell line, we identified hypermethylation associated loss of NNAT. In this report, we determined the expression pattern of NNAT in individual cell types of the normal gland and within each of the different pituitary adenoma subtypes. In addition, we determined associations between expression and CpG island methylation and used colony forming efficiency assays (CFE) to gain further insight into the tumour-suppressor function of this gene. Immunohistochemical (IHC) co-localization studies of normal pituitaries showed that each of the hormone secreting cells (GH, PRL, ACTH, FSH and TSH) expressed NNAT. However, 33 out of 47 adenomas comprising, 11 somatotrophinomas, 10 prolactinomas, 12 corticotrophinomas and 14 non-functioning tumours, irrespective of subtype failed to express either NNAT transcript or protein as determined by quantitative real-time RT-PCR and IHC respectively. In normal pituitaries and adenomas that expressed NNAT the promoter-associated CpG island showed characteristics of an imprinted gene where approximately 50% of molecules were densely methylated. However, in the majority of adenomas that showed loss or significantly reduced expression of NNAT, relative to normal pituitaries, the gene-associated CpG island showed significantly increased methylation. Induced expression of NNAT in transfected AtT-20 cells significantly reduced CFE. Collectively, these findings point to an important role for NNAT in the pituitary and perhaps tumour development in this gland.

Pituitary tumours : all silent on the epigenetics front

Investigation of the epigenome of sporadic pituitary tumours is providing a more detailed understanding of aberrations that characterise this tumour type. Early studies, in this and other tumour types adopted candidate-gene approaches to characterise CpG island methylation as a mechanism responsible for or associated with gene silencing. However, more recently, investigators have adopted approaches that do not require a priori knowledge of the gene and transcript, as example differential display techniques, and also genome-wide, array-based approaches, to 'uncover' or 'unmask' silenced genes. Furthermore, through use of chromatin immunoprecipitation as a selective enrichment technique; we are now beginning to identify modifications that target the underlying histones themselves and that have roles in gene-silencing events. Collectively, these studies provided convincing evidence that change to the tumour epigenome are not simply epiphenomena but have functional consequences in the context of pituitary tumour evolution. Our ability to perform these types of studies has been and is increasingly reliant upon technological advances in the genomics and epigenomics arena. In this context, other more recent advances and developing technologies, and, in particular, next generation or flow cell re-sequencing techniques offer exciting opportunities for our future studies of this tumour type.

Effects of artificial shade on attack by the mahogany shoot borer, Hypsipyla robusta (Moore)

Swietenia macrophylla King (Meliaceae: Swietenioideae) provides one of the premier timbers of the world. The mahogany shoot borer Hypsipyla robusta Moore (Lepidoptera: Pyralidae) is an economically important pest of S. macrophylla throughout Asia, Africa and the Pacific. No viable method of controlling this pest is known. Previous observations have suggested that the presence of overhead shade may reduce attack by H. robusta, but this has not been investigated experimentally. This research was therefore designed to assess the influence of light availability on shoot-borer attack on S. macrophylla, by establishing seedlings under three different artificial shade regimes, then using these seedlings to test oviposition preference of adult moths, neonate larval survival and growth and development of shoot borer larvae. Oviposition preference of shoot borer moths was tested on leaves from seedlings grown under artificial shade for 63 weeks. A significant difference in choice was recorded between treatments, with 27.4 ± 1.5 eggs laid under high shade and 87.1 ± 1.8 under low shade. Neonate larval survival on early flushing leaflets of S. macrophylla did not differ significantly between shade treatments. Larval growth rate, estimated by measuring daily frass width, was significantly higher for those larvae fed on seedlings from the high and medium shade treatments (0.1 mm/day), than the low shade treatment (0.06 mm/day). In laboratory-reared larvae, the total mass of frass produced was significantly higher in the high shade treatment (0.4 g) than under the low shade treatment (0.2 g). Longer tunnel lengths were bored by larvae in plants grown under high shade (12.0 ± 2.4 cm) than under low shade (7.07 ± 1.9 cm). However, pupal mass under low shade was 48% higher than that under the high shade treatment, suggesting that plants grown under high shade were of lower nutritional quality for shoot borer larvae. These results indicate that shading of mahogany seedlings may reduce the incidence of shoot borer attack, by influencing both oviposition and larval development. The establishment of mahogany under suitable shade regimes may therefore provide a basis for controlling shoot borer attack using silvicultural approaches.

Resistance or covert infection : baculovirus studies re-examined

Recently, Boots & Begon (1993) described the development of resistance to granulosis virus (GV) (Baculoviridae) infection in the moth Plodia interpunctella, following prolonged exposure to virus in laboratory cultures. Resistant insects exhibited reduced fitness in other respects, namely slower development and reduced egg viability, compared to control insects. These results were interpreted as pleiotropic effects of selection at the loci controlling resistance. Similar results have been described in a previous study: Fuxa & Richter (1989) used artificial selection to increase resistance to nuclear polyhedrasis virus (NPV) (Baculoviridae) infection in the moth Spodoptera frugiperda. The resulting gain in resistance they interpreted as the result of an increase in the frequency of alleles conferring resistance. Again, resistant insects exhibited maladaptive traits compared to controls, including a shorter adult life span, reduced number of eggs and reduced egg viability. In both studies the suggestion is made that selection against maladaptive traits will result in a decline in resistance, once selection for resistance is removed. Boots & Begon (1993) described a decrease in development time (towards that of control insects) within two generations of removing selection for resistance. Fuxa & Richter (1989) describe a decrease in resistance, so that within two generations of relaxing selection, previously resistant lines were not significantly more resistant than control insects. . .

Author response to : Brough et al. in response to the recently published article : Lottering,N., MacGregor,D.M.,Barry,M.D.,Reynolds,M.S., Gregory,L.S., 2014. Introducing standardized protocols for anthropological measurement of virtual sub-adult crania using computed tomography 2(1),34–38

Firstly, we would like to thank Ms. Alison Brough and her colleagues for their positive commentary on our published work [1] and their appraisal of our utility of the “off-set plane” protocol for anthropometric analysis. The standardized protocols described in our manuscript have wide applications, ranging from forensic anthropology and paleodemographic research to clinical settings such as paediatric practice and orthopaedic surgical design. We affirm that the use of geometrically based reference tools commonly found in computer aided design (CAD) programs such as Geomagic Design X® are imperative for more automated and precise measurement protocols for quantitative skeletal analysis. Therefore we stand by our recommendation of the use of software such as Amira and Geomagic Design X® in the contexts described in our manuscript...

Cuelure but not zingerone make the sex pheromone of male Bactrocera tryoni (Tephritidae: Diptera) more attractive to females

In tephritid fruit flies of the genus Bactrocera Macquart, a group of plant derived compounds (sensu amplo ‘male lures') enhance the mating success of males that have consumed them. For flies responding to the male lure methyl eugenol, this is due to the accumulation of chemicals derived from the male lure in the male rectal gland (site of pheromone synthesis) and the subsequent release of an attractive pheromone. Cuelure, raspberry ketone and zingerone are a second, related group of male lures to which many Bactrocera species respond. Raspberry ketone and cuelure are both known to accumulate in the rectal gland of males as raspberry ketone, but it is not known if the emitted male pheromone is subsequently altered in complexity or is more attractive to females. Using Bactrocera tryoni as our test insect, and cuelure and zingerone as our test chemicals, we assess: (i) lure accumulation in the rectal gland; (ii) if the lures are released exclusively in association with the male pheromone; and (iii) if the pheromone of lure-fed males is more attractive to females than the pheromone of lure-unfed males. As previously documented, we found cuelure was stored in its hydroxyl form of raspberry ketone, while zingerone was stored largely in an unaltered state. Small but consistent amounts of raspberry ketone and β-(4-hydroxy-3-methoxyphenyl)-propionic acid were also detected in zingerone-fed flies. Males released the ingested lures or their analogues, along with endogenous pheromone chemicals, only during the dusk courtship period. More females responded to squashed rectal glands extracted from flies fed on cuelure than to glands from control flies, while more females responded to the pheromone of calling cuelure-fed males than to control males. The response to zingerone treatments in both cases was not different from the control. The results show that male B. tryoni release ingested lures as part of their pheromone blend and, at least for cuelure, this attracts more females.

Indirect effects of phytochemicals on offspring performance of Queensland fruit fly, Bactrocera tryoni (Diptera: Tephritidae)

Phytochemical lures such as methyl eugenol (ME) and cue-lure are used in the management of Bactrocera fruit flies for monitoring and control. These lures are not just attractants, but also trigger physiological changes in males that lead to enhanced mating success. Additionally, in the cue-lure-responsive Bactrocera tryoni, females mated with lure-fed males exhibit changes in fecundity, remating receptivity and longevity. While the lures show current generation effects, no research has been carried out on possible multigenerational effects, although such effects have been hypothesized within a ‘sexy-son’ sexual selection model. In this study, we test for indirect, cross-generational effects of lure exposure in F1offspring of B. tryoni females mated with cue-lure-fed, zingerone-fed and lure-unfed (=control) males. The F1 attributes we recorded were immature development time, immature survival, adult survival and adult male lure foraging. No significant differences were found between treatments for any of the three life-history measurements, except that the offspring sired by zingerone-fed males had a longer egg development time than cue-lure and control offspring. However, indirect exposure to lures significantly enhanced the lure-foraging ability of F1 adult males. More offspring of cue-lure-fed males arrived at a lure source in both large flight cages and small laboratory cages over a 2-h period than did control males. The offspring of zingerone-fed males were generally intermediate between cue-lure and control offspring. This study provides the first evidence of a next generation effect of fruit fly male lures. While the results of this study support a ‘sexy-son’ sexual selection mechanism for the evolution of lure response in Bactrocera fruit flies, our discussion urges caution in interpreting our results in this way.

Physical, chemical, biological and ecotoxicological properties of wastewater discharged from Davis Station, Antarctica

The properties and toxicity of untreatedwastewater at Davis Station, East Antarctica,were investigated to inform decisions regarding the appropriate level of treatment for local discharge purposes and more generally, to better understand the risk associated with dispersal and impact of wastewaters in Antarctica. Suspended solids, nutrients (nitrogen, phosphorus), biological oxygen demand (BOD), metals, organic contaminants, surfactants and microbiological load were measured at various locations throughout the wastewater discharge system. Wastewater quality and properties varied greatly between buildings on station, each ofwhich has separate holding tanks. Nutrients, BOD and settleable solid levelswere higher than standard municipal wastewaters. Microbiological loads were typical of untreated wastewater. Contaminants detected in the wastewater included metals and persistent organic compounds, mainly polybrominated diphenyl ethers (PBDEs). The toxicity of wastewater was also investigated in laboratory bioassays using two local Antarctic marine invertebrates, the amphipod Paramoera walkeri and the microgastropod Skenella paludionoides. Animals were exposed to a range of wastewater concentrations from3% to 68% (test 1) or 63% (test 2) over 21 days with survival monitored daily. Significant mortality occurred in all concentrations of wastewater after 14 to 21 days, and at higher concentrations (50–68% wastewater) mortality occurred after only one day. Results indicate that the local receiving marine environment at Davis Station is at risk from existing wastewater discharges, and that advanced treatment is required both to remove contaminants shown to cause toxicity to biota, as well as to reduce the environmental risks associated with non-native micro-organisms in wastewater.