Subsequent Viability Research Articles

Rhamnus prinoides (gesho): A source of diverse anti-biofilm activity

Ethnopharmacological relevanceRhamnus prinoides (gesho) is an evergreen shrub from East Africa traditionally used for the treatment of illnesses including atopic dermatitis, ear, nose and throat infections, pneumonia, arthritis, brucellosis, flu, indigestion and fatigue. Aim of the studySeveral of the conditions for which gesho is traditionally used are associated with communities of surface-attached microorganisms, or biofilms. We hypothesized that gesho has anti-biofilm activity. The principal aim of this study was to evaluate gesho-associated anti-biofilm activity and identify active compounds. Materials and methodsLyophilized ethanol and aqueous extracts were prepared from dried Rhamnus prinoides stems and leaves. Biofilm inhibition was measured by crystal violet staining and subsequent viability assays were conducted on growth agar. Chemical fractionation, chemical testing, Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS) were used to isolate and identify active compounds. ResultsLeaf and stem ethanol extracts significantly inhibited Staphylococcus aureus, Bacillus subtilis and Streptococcus mutans biofilm formation up to 99.9% and reduced planktonic cell growth up to 10 log units relative to untreated controls. The anti-biofilm activity of the ethanol stem extracts was due to a biocidal or bacteriostatic mechanism while bacteriostatic or anti-pathogenic mechanisms were attributed to the leaf ethanol extract. Gesho extracts showed activity against all three species tested but the treatment efficacy and mechanism were species dependent. Chemical fractionation and activity screens of the leaf ethanol extract identified ethyl 4-ethoxybenzoate and 4-hydroxy 4-methyl pentanone to be compounds with anti-biofilm activity. Ethyl 4-ethoxybenzoate activity was potentiated by DMSO. Notably, concentrations of both compounds were identified where biofilm formation was prevented without inhibition of cell growth; i.e. anti-pathogenic characteristics were evident. ConclusionGesho leaf ethanol extract contains chemicals with anti-biofilm and bactericidal activities. This work lends support to the traditional use of gesho for treating topical infections and warrants further investigation into Rhamnus prinoides as a source of antibacterial and anti-biofilm agents.

Microhair on the adaxial leaf surface of salt secreting halophytic Oryza coarctata Roxb. show distinct morphotypes: Isolation for molecular and functional analysis

Halophytic Oryza coarctata is a good model system to examine mechanisms of salinity tolerance in rice. O. coarctata leaves show the presence of microhairs in adaxial leaf surface furrows that secrete salt under salinity. However, detailed molecular and physiological studies of O. coarctata microhairs are limited due to their relative inaccessibility. This work presents a detailed characterization of O. coarctata leaf features. O. coarctata has two types of microhairs on the adaxial leaf surface: longer microhairs (three morphotypes) lining epidermal furrow walls and shorter microhairs (reported first time) arising from bulliform cells. Microhair morphotypes include (i) finger-like, tubular structures, (ii) tubular hairs with bilobed and flattened heads and (iii) bi-or trifurcated hairs. The unicellular nature of microhairs was confirmed by propidium iodide (PI) staining. An efficient method for the isolation and enrichment of O. coarctata microhairs is presented (yield averaging ˜2 × 105/g leaf tissue). The robustness of the microhair isolation procedure was confirmed by subsequent viability staining (PI), total RNA isolation and RT-PCR amplification of O. coarctata trichome-specific WUSCHEL-related homeobox 3B (OcWox3B) and transporter gene-specific cDNA sequences. The present microhair isolation work from O. coarctata paves the way for examining genes involved in ion secretion in this halophytic wild rice model.

Influence of bioactive glass-coating of zirconia implant surfaces on human osteoblast behavior in vitro

ObjectiveThe recently developed bioactive glass PC-XG3, which is suitable to coat zirconia implant surfaces with high adhesion strength may reduce the time of osseointegration and the marginal bone loss following implantation. The glass composition has been previously evaluated for cytotoxicity on fibroblast cells, and will now be used to evaluate the cell behavior of osteoblast cells. MethodsThree different surface morphologies were created with PC-XG3 on zirconia discs. A clinically tested zirconia implant surface as well as polished and machined zirconia served as a reference. Cell viability after 24 h, cell spreading after 30 min and 24 h and the respective morphology of human osteoblasts using scanning electron microscopy were evaluated. Additionally, the corrosive process of PC-XG3 in cell culture medium up to 7 d was measured. ResultsInitial cell behavior of human osteoblasts was not accelerated by the PC-XG3 surface when compared to zirconia. Additionally, it was found that a decreased surface roughness promoted initial cell spreading. Storage in cell culture medium resulted in the accumulation of C and N on the bioglass surface while Mg, Si, K and Ca were decreased and crack formation was observed. SignificanceSince initial spreading quality to a biomaterial is a crucial factor that will determine the subsequent cell function, proliferation, differentiation, and viability it can be assumed that a coating of zirconia implants with this bioactive glass will unlikely reduce osseointegration time.

Cell-laden interpenetrating network hydrogels formed from methacrylated gelatin and silk fibroin via a combination of sonication and photocrosslinking approaches

The regeneration of load-bearing soft tissues has long driven the research and development of bioactive hydrogels. A major challenge facing the application of hydrogels to load-bearing tissues is the development of hydrogels with appropriate biological functionality and biomechanical stability that closely mimic the host tissue. In this paper, we describe a newly synthesized cell-laden interpenetrating polymer network (IPN) hydrogel based on gelatin methacrylate (GelMA) and silk fibroin (SF) that was formed via sequential sonication and photocrosslinking. The experimental results revealed that SF-GelMA IPN hydrogels exhibited high swelling ratios, excellent mechanical properties, resistance to enzymatic degradation by collagenase, and porous internal microstructures. Moreover, these properties could be tailored by changing the prepolymer components. MC3T3-E1 pre-osteoblasts attached to and subsequently proliferated on the IPN hydrogels, as demonstrated by fluorescein diacetate/propidium iodide (FDA/PI) staining and Cell Counting Kit-8 (CCK-8) analysis. In addition, the encapsulation of MC3T3-E1 pre-osteoblasts and a subsequent cell viability assay demonstrated that the entire IPN formation process was compatible with cells and that the growth of encapsulated cells could be tuned by adjusting the GelMA concentration, underlining their versatility for various load-bearing soft tissue engineering. Overall, this study introduces a class of mechanically robust and tunable cell-laden IPN hydrogels which have great potential as load-bearing soft tissue engineering scaffold.

Temperature-responsive tungsten doped vanadium dioxide thin film starves bacteria to death

Abstract The colonization of microorganisms on material surfaces, or namely biofouling, is a challenging matter in both the medical and marine industries. With the inspiration of the metabolism cascade of microorganisms, this study develops a new antifouling material surface that enables the drainage of extracellular electrons from the electron transfer chain in microbial metabolism, thereby interrupting the energy metabolism and subsequent microbial viability. This thought has been realized by tungsten-doped vanadium dioxide (VO2) thin film using customized magnetron-sputtering deposition. The aim of tungsten doping is to tune the semiconductor-to-metal phase change of the VO2 thin film and then endow the temperature-responsive electrical conductivity (band structure). While contacting with microorganisms, the electrically conductive VO2 can disrupt the membrane respiration function of bacteria. This antifouling phenomenon can be explained by a three-step mechanism. The initial step is the microbial adhesion onto the metallic VO2 film to form the direct microbe–VO2 physical contact, which leads to the destructive extraction of electrons from the transmembrane protein complex of the respiratory chain (a discharge process); this induces oxidative stress and energy starvation and, eventually, interrupts the microbial membrane function. Finally, the microbial membrane integrity is destroyed, which leads to intracellular matter leakage (electrocution). This study demonstrates that the temperature-dependent VO2 electrical conductivity or band structure serves as a key factor to modulate the antimicrobial capability of tungsten-doped VO2 thin film. It is believed that the current findings can provide a new insight for the development of new antifouling surfaces.

Oral ingestion of a novel oxygenating compound, Ox66™, is non-toxic and has the potential to increase oxygenation

Ox66™ is a novel solid state oxygenating compound. In order to support the use of Ox66™ as a potential oxygenating supplement to injured cells, this study evaluated the safety of Ox66™, its ability to withstand the conditions in the digestive tract, and its potential to increase oxygenation in the mesentery in rats. The toxicity of Ox66™ was evaluated by performing acute (10-day) and chronic (90-day) feeding studies on rats, the stability of the compound in the digestive tract was evaluated via ex vivo simulated digestion and subsequent CFDA viability assay on gut epithelial cells, and its capacity for oxygenation in the mesenteric microcirculation was determined by interstitial fluid pressure (PISF) O2 measurements upon injection into the small intestine of rats. No toxicity was found associated with acute or chronic oral administration of the compound in rats, and the compound was able to withstand the environment of the digestive tract in vitro. Based on the acute animal feeding study, the NOAEL was considered to be 1000 mg/kg/day. This proof-of-concept study further demonstrates the potential of Ox66™ to function as an oxygenating supplement that might be useful for treating either pathological hypoxic-related conditions or to improve oxygenation levels during or after exercise under healthy conditions.

Evidencias moleculares de hibridación entre Serinus canaria domestica (L., 1758) y Spinus barbatus (Molina, 1782) (Aves: Fringillidae)

espanolEn este estudio se muestran evidencias moleculares de exito en la hibridacion entre Serinus canaria domestica (linnaeus, 1758) y Spinus barbatus (molina, 1782). Como parte de una secuencia de retrocruzamiento, se logro reproducir hibridos F2 a partir de hembras hibridas fertiles viables F1 x S. c. domestica. La F1 fue la descendencia entre P0 = Serinus c. domestica x Spinus barbatus. Las secuencias de nucleotidos de dos segmentos de ADN, citocromo b mitocondrial (Cyt b) y el receptor de tirosina quinasa muscular (MuSK) del ADN nuclear se obtuvieron de tres especimenes hibridos F2. Tanto las secuencias de Cyt b como de MuSK senalaron fuerte soporte filogenetico a la condicion genetica hibrida de los tres embriones F2. De esta manera la evidencia molecular refleja el exito en el cruce interespecifico entre S. barbatus con S. c. domestica y que es posible obtener hibridos fertiles viables F1 (en este caso hembras) y F2 entre estos dos linajes en poblaciones naturales. EnglishIn this study we show molecular evidences of success in hybridization between Serinus canaria domestica and Spinus barbatus. As part of a sequence of backcrossing we have achieved to reproduce F2 hybrids of fertile hybrid females F1 with parental S. c. domestica. F1 was the offspring between, P0 = S. c. domestica x S. barbatus. In this study the space where the observations and the breeding success are carried out between these species, they are described: is a room with the following measures; 4,45 m (lenghty) x 1,60 m (width) x 2,30 m (high), located in an urban building; specifically, glassed-balcony at a height of 10,60 m above ground level, facing some ornamental and exuberant canopy trees of Platanus orientalis (L., 1753) and with direct entrance of natural sunlight, in urban city of Santiago, Chile, where his perceptual world develops. We took care to keep the biotic and abiotic factors under control; specifically, incoming natural light, ambient vegetation and temperature. On the other hand, we fed the individuals appropriately and provided them with plenty of clean water to drink and get clean, where there were no predators. In sum, the individuals were kept in a healthy environment. The backcrossing between the male S. c. domestica (generation 0) bred with two viable hybrid F1 offspring females, it gave as resulted in a total of three independent generations of F2 hybrids (n = 12). All the individuals came out healthy, and none of them died, despite being inbred lineages. Three embryos representative of the F2 hybrids were sacrificed and deposited in 99% alcohol. Nucleotide sequences of two DNA segments, mitochondrial cytochrome b (Cyt b) and muscle-specific receptor tyrosine kinase (MuSK) gene of the nuclear DNA were obtained from three F2 hybrid specimens. The model of molecular evolution with the greatest adjustment to the data obtained by jModeltest was GTR + I + G (I = 0,1450, G = 0,0930), according to the phylogenetic analysis of mitochondrial DNA (Fig. 1a), the female progenitor P0 is S.c.domestica. This conclusion is based on the evi- dence that mitochondrial DNA in birds, as well as in most animal groups, is exclusively inherited through the maternal ways. The same analysis carried out with the nuclear MuSK gene shows that the parental male P0 of the embryos analyzed is very much related to S. barbatus (Fig. 1b). The Cyt b and MuSK region show strongly support to hybrids genetic condition of the three F2 embryos. Intergeneric hybrids are usually sterile, but it is worth noting that genera of Fringillidae are very closely related (the Family as a whole is only 12 million years old, and most genera in the terminal canary-siskin group are In addition, hybrids produced ex situ under controlled conditions would play an important role for reproductive success and subsequent interspecific viability. The main conclusions derived from this study are as follows: 1) The present report strongly indicates that hybridizations have occurred among S. c. canary x S. barbatus. 2) In this way the molecular evidence reflects and justifies the success in interspecific reproduction between S. barbatus with S. c. domestica and that it is possible to obtain viable fertile hybrids F1 (in this case females) and F2 between these two lineages, 3) And consequently the close genetic affinity between these two genera and the formation of hybrids in natural populations should not discard.

Curcumin and fisetin internalization into Saccharomyces cerevisiae cells via osmoporation: impact of multiple osmotic treatments on the process efficiency.

For the first time in the literature, a protocol of serial osmoporation stages to enhance the encapsulation efficiency of hydrophobic low molecular weight molecules (curcumin and fisetin) into Saccharomyces cerevisiae cells was determined. By increasing overall efficiency, this protocol empowers the encapsulation process and creates a rational way to reduce waste for future industrial osmoporation applications.

Defining Health Service Eco-System “Infection”: A Critical Analysis of Patient Surveys

Purpose – This paper focuses on the analysis of the most common tools that health care organizations use to assess the quality of the delivered services, the patient surveys. In line with the results of a systematic literature review on the issue, the study embraces service ecosystem perspective to understand why these surveys are unable to grasp actors’ disposition to co-create value for the health care system. Methodology – An in-depth literature review based on PRISMA framework explored 34 works on the topic of patient surveys in order to trace the evolution of the relationship users/providers and to highlight the criticalities related to the adoption of patient surveys in service-oriented era. The study discusses critically their efficacy to understand how they can affect (positively or negatively) the viability of a health care service eco-system. Findings – The literature review highlights patient surveys inability in grasping the real perception that patients have of experienced services and in involving them in value co-creation, through their engagement in service design and delivery. Moreover, the results reveal the need to adopt Service Dominant (S-D) Logic and service eco-system perspective to reread the traditional tools to measure quality in healthcare. For this reason, the metaphor of health service eco-system “infection” is launched, depicting the negative influence of patient satisfaction surveys on value co-creation and the subsequent service eco-system viability. Practical implications – The study shows that assuming a service eco-system perspective based on S-D logic, health care system should boost and preserve value co-creation processes. Moreover, institutions should foster those “rules of the game” that institutionalize the contribution of health providers to value co-creation, defining specific strategies to avoid the “infections” of health care service eco-system, e.g. investing and promoting non-detrimental tools.Originality – This study represents one of the first attempts to reread the tools used to assess patient embracing a service eco-system perspective. Interesting implications have been presented in terms of the negative effect that traditional assessment tools have on providers, patients and the whole society.

Transposons and the PIWI pathway: genome defense in gametes and embryos

Hiding in plain sight within the genome of virtually every eukaryotic organism are large numbers of sequences known as transposable elements (TEs). These sequences often comprise 50% or more of the DNA in many mammals and are transcriptionally constrained by DNA methylation and repressive chromatin marks. Individual TEs, when relieved of these epigenetic constraints, can readily move from one genomic location to another, either directly or through RNA intermediates. Demethylation and removal of repressive histone marks during epigenetic reprogramming stages of gametogenesis and embryogenesis render the genome particularly susceptible to increased TE mobilization, which has significant implications for the fidelity of genome replication and subsequent viability of the progeny. Importantly, however, TEs have functionally integrated themselves into developmental events to the extent that complete suppression precludes normal gamete and embryo development. Consequently, multiple mechanisms have evolved to limit the extent of TE expression and mobilization during reprogramming without completely suppressing it. One of the most important TE repression mechanisms is the PIWI/piRNA pathway, in which 25–32 nucleotide RNA molecules known as piRNAs associate with Argonaute proteins from the PIWI clade to form piRISC complexes. These complexes target and silence TEs post-transcriptionally and through the induction of epigenetic changes at the loci from which they are expressed. This review will briefly discuss the intricate molecular détente between TE expression and its suppression by the PIWI pathway, with particular emphasis on mammalian species including human, bovine and murine.

Influence of key processing parameters and seeding density effects of microencapsulated chondrocytes fabricated using electrohydrodynamic spraying

Cell delivery and leakage during injection remains a challenge for cell-based intervertebral disc regeneration strategies. Cellular microencapsulation may offer a promising approach to overcome these limitations by providing a protective niche during intradiscal injection. Electrohydrodynamic spraying (EHDS) is a versatile one-step approach for microencapsulation of cells using a high voltage electric field. The primary objective of this work was to characterise key processing parameters such as applied voltage (0, 5, 10 or 15 kV), emitter needle gauge (21, 26 or 30 G), alginate concentration (1%, 2% or 3%) and flow rate (50, 100, 250 or 500 μl min−1) to regulate the size and morphology of alginate microcapsules as well as subsequent cell viability when altering these parameters. The effect of initial cell seeding density (5, 10 and 20 × 106 cells ml−1) on subsequent matrix accumulation of microencapsulated articular chondrocytes was also evaluated. Results showed that increasing alginate concentration and thus viscosity increased overall microcapsule size but also affected the geometry towards ellipsoidal-shaped gels. Altering the electric field strength and needle diameter regulated microcapsule size towards a smaller diameter with increasing voltage and smaller needle diameter. Needle size did not appear to affect cell viability when operating with lower alginate concentrations (1% and 2%), although higher concentrations (3%) and thus higher viscosity hydrogels resulted in diminished viability with decreasing needle diameter. Increasing cell density resulted in decreased cell viability and a concomitant decrease in DNA content, perhaps due to competing nutrient demands as a result of more closely packed cells. However, higher cell densities resulted in increased levels of extracellular matrix accumulated. Overall, this work highlights the potential of EHDS as a controllable and versatile approach to fabricate microcapsules for injectable delivery which can be used in a variety of applications such as drug development or cell therapies.

Parched plants: survival and viability of invasive aquatic macrophytes following exposure to various desiccation regimes

Invasive alien species represent a serious worldwide threat to natural and semi-natural ecosystems. Although successful overland transport of invasive aquatic macrophytes can be facilitated by more mobile organisms or anthropogenic activity, tolerance to desiccation is likely a limiting factor. Particularly in the case of vegetative fragmentary propagules. Here we examined survival and subsequent viability (i.e. regeneration by production of new shoot or root growth) for whole plantlets of two floating (Azolla filiculoides, Lemna minuta) and stem fragments of three submerged (Elodea canadensis. E. nuttallii, Lagarosiphon major) invasive macrophytes following exposure to different desiccation regimes. Species were exposed to selected temperature (20, 27, 36 °C) and relative humidity (18, 38, 60, 85% RH) combinations for up to six hours. In general, floating plants displayed greater survival and viability than submerged species. Overall, survival and viability decreased significantly for all species with increased desiccation exposure times. In essence, increased vapour-pressure deficit significantly reduced survival of aquatic plants. Although reduced humidity rates particularly decreased survival and viability, increased temperatures were observed to bolster the impact of certain humidity treatments. In particular, when exposed to low RH (≤38%RH), little or no viability was observed after 2 h. Contrastingly, propagules kept under RH above 60% RH at 20 °C retained viability for considerably longer intervals above 4–6 h. Overall, desiccation as a biosecurity tool alone is likely inadequate to prevent the spread of fragmentary propagule stages, as even small desiccated fragments that appear to be dry may still be viable.

Managerial Ability and the Accuracy of the Going Concern Opinion

ABSTRACTCurrent audit guidance directs the auditor to modify their opinion in the presence of significant doubt about their client's ability to continue as a going concern. This paper examines whether managerial ability influences the accuracy of auditors' going concern information signal. Following prior literature, we assess accuracy based on the subsequent viability of the client. We find that, while managerial ability decreases the risk of Type I errors (the auditor issues a going concern opinion for a firm that subsequently remains viable), managerial ability increases the risk of Type II errors (the auditor issues a standard unqualified report for a firm that subsequently files for bankruptcy). Considering prior research indicates that the auditor's opinion provides important information to the market, this finding has important public interest implications regarding the signaling of bankruptcy risk to investors and creditors by auditors' going concern opinion.

Electrospun Composites of Polycaprolactone and Porous Silicon Nanoparticles for the Tunable Delivery of Small Therapeutic Molecules.

This report describes the use of an electrospun composite of poly(ε-caprolactone) (PCL) fibers and porous silicon (pSi) nanoparticles (NPs) as an effective system for the tunable delivery of camptothecin (CPT), a small therapeutic molecule. Both materials are biodegradable, abundant, low-cost, and most importantly, have no known cytotoxic effects. The composites were treated with and without sodium hydroxide (NaOH) to investigate the wettability of the porous network for drug release and cell viability measurements. CPT release and subsequent cell viability was also investigated. We observed that the cell death rate was not only affected by the addition of our CPT carrier, pSi, but also by increasing the rate of dissolution via treatment with NaOH. This is the first example of loading pSi NPs as a therapeutics nanocarrier into electronspun PCL fibers and this system opens up new possibilities for the delivery of molecular therapeutics.

Probing the toxicity mechanism of multiwalled carbon nanotubes on bacteria.

Carbon nanotubes (CNTs) have emerged recently as superior adsorbent materials for the removal of recalcitrant pollutants. The potential of combining the sorption capability of CNTs with bacterial degradation for pollutant removal, however, necessitates further investigation of the mechanisms of CNTs' toxicity towards bacterial cells. In this study, we used a panel of stress-responsive recombinant Escherichia coli bioluminescence bacterial strains to explore the possible mechanisms of toxicity of multiwalled carbon nanotubes (MWCNTs). The effects of MWCNTs on markers of oxidative stress, protein, DNA, and membrane damage enabled the exposition of some of the mechanisms of their antimicrobial properties. Using both a bioluminescence bioreporter panel and live/dead staining, we observed that membrane damage played a role in the toxicity of MWCNTs. A subsequent viability study using three strains of bacteria-two gram-negative (Escherichia coli, Pseudomonas aeruginosa) and one gram-positive (Bacillus subtilis)-showed significant MWCNT toxicity in hypotonic water and phosphate-buffered saline solution, compared with the MWCNT toxicity towards the same bacteria incubated in isotonic-rich media. Using a field-emission scanning electron microscope, we demonstrated that membrane damage is caused largely by MWCNTs trapping bacteria and piercing the cell walls. As a result of our observations, we propose integrating MWCNTs and bacteria degradation for pollutant removal in nutrient-rich media to minimize the toxicity effect of CNTs.

Is meiosis a fundamental cause of inviability among sexual and asexual plants and animals?

Differences in viability between asexually and sexually generated offspring strongly influence the selective advantage and therefore the prevalence of sexual reproduction (sex). However, no general principle predicts when sexual offspring will be more viable than asexual offspring. We hypothesize that when any kind of reproduction is based on a more complex cellular process, it will encompass more potential failure points, and therefore lower offspring viability. Asexual reproduction (asex) can be simpler than sex, when offspring are generated using only mitosis. However, when asex includes meiosis and meiotic restitution, gamete production is more complex than in sex. We test our hypothesis by comparing the viability of asexual and closely related sexual offspring across a wide range of plants and animals, and demonstrate that meiotic asex does result in lower viability than sex; without meiosis, asex is mechanistically simple and provides higher viability than sex. This phylogenetically robust pattern is supported in 42 of 44 comparisons drawn from diverse plants and animals, and is not explained by the other variables included in our model. Other mechanisms may impact viability, such as effects of reproductive mode on heterozygosity and subsequent viability, but we propose the complexity of cellular processes of reproduction, particularly meiosis, as a fundamental cause of early developmental failure and mortality. Meiosis, the leading cause of inviability in humans, emerges as a likely explanation of offspring inviability among diverse eukaryotes.

Integration of wild and captive genetic management approaches to support conservation of the endangered Japanese golden eagle

The loss of biological diversity within species has the potential to significantly reduce resilience in the face of environmental change. Conservation of genetic variation needs to consider all available sources of diversity within a species, and approaches are required to integrate population management across traditionally separate wild and captive population domains. Here we report on a study that utilises different types of genetic analysis at different taxonomic scales and across an in situ – ex situ transition to support conservation planning for the Japanese golden eagle, a subspecies in serious regional decline. Mitochondrial DNA sequencing and nuclear DNA profiling are used to investigate subspecies differentiation and diversity in the natural population, revealing relatively high levels of variation in Japan. These results are compared with data from a newly established conservation breeding programme that indicates good representation of wild genetic variation in the captive founders. However, subsequent population viability analysis (PVA) to examine the demographic and genetic future of the captive population demonstrates the severe effects of existing reproductive skews, suggesting that this population is not sustainable without intensive genetic management. Lastly, the use of available molecular tools to validate and reconstruct pedigrees in Japanese golden eagle are evaluated and discussed in the context of captive and wild conservation management. The paper highlights the importance of producing and utilising comparative molecular genetic data across the population management spectrum and the benefits of PVA to support the implementation of integrated conservation plans.

Toxicity effects of sumithion on the breeding performance and viability of eggs, embryos and subsequent growth indices of Heteropneustes fossilis larvae

Sumithion, an organophosphate pesticide, has been used extensively in agriculture as well as in broodfish and nursery ponds in Bangladesh. Although it is being applied for beneficial purposes but eventually it exhibits some short and long term toxic effects to the aquatic ecosystem. Therefore, the present study investigated the toxic effects of sumithion on the breeding performance and subsequent viability of embryos and larvae of Heteropneustes fossilis. A total of 400 adult H. fossilis were equally stocked in two ponds. Sumithion at the dose of 0.24 ppm was applied for four months every 7 days interval in one pond while the rest one was considered as control. No significant (p>0.05) difference was found in growth between the treated and control H. fossilis; however, fertilization and hatching rates of the eggs obtained from the treated group were significantly (p>0.05) lower than that of control. Subsequently, the embryos and larvae produced from the broods of the control pond were exposed to 5 different concentrations of sumithion (0.5, 1.0, 2.0, 4.0, and 8.0 ppm) against a control (0 ppm). Each concentration was assessed in five replicates having 200 eggs. Data obtained from the sumithion acute toxicity tests were evaluated using the Probit Analysis. The mortality of embryos increased with the increasing sumithion concentrations from 0 to 8.0 ppm and the significant (p>0.05) differences were found only among the treated concentrations above 2.0 ppm. The 24 h LC50 value for embryos was estimated to be 7.803 ppm. Dose-response decreased in hatching success and recorded as 90.8, 85.0, 76.2, 73.0, 65.0, and 51.2 % for control and 5 different concentrations of sumithion, respectively (p<0.05). The numbers of dead larvae also increased significantly with the increasing sumithion concentrations exposed for 24- 96 h. The 24, 48, 72, and 96 h LC50 values were estimated to be 8.677, 8.245, 7.664, and 6.782 ppm, respectively and these values were significantly (p<0.05) different to each other. Besides, the larvae obtained from 0.5, 2.0, and 8.0 ppm sumithion were reared against a control for 21 days to assess the residual effect. Significant negative effects on both growth and survival of the larvae were found among the sumithion concentrations used. The study therefore, suggested that sumithion has adverse and residual effects on the breeding performance along with early embryonic and larval development of H. fossilis even in lower concentration.J. Bangladesh Agril. Univ. 14(2): 243-251, December 2016

Ferroelectric surfaces for cell release

Adherent cells cultured in vitro must usually, at some point, be detached from the culture substrate. Presently, the most common method of achieving detachment is through enzymatic treatment which breaks the adhesion points of the cells to the surface. This comes with the drawback of deteriorating the function and viability of the cells. Other methods that have previously been proposed include detachment of the cell substrate itself, which risks contaminating the cell sample, and changing the surface energy of the substrate through thermal changes, which yields low spatial resolution and risks damaging the cells if they are sensitive to temperature changes. Here cell culture substrates, based on thin films of the ferroelectric polyvinylidene fluoride trifluoroethylene (PVDF-TrFE) co-polymer, are developed for electroactive control of cell adhesion and enzyme-free detachment of cells. Fibroblasts cultured on the substrates are detached through changing the direction of polarization of the ferroelectric substrate. The method does not affect subsequent adhesion and viability of reseeded cells.

Antitumor effect of sunitinib in human prostate cancer cells functions via autophagy.

The aim of the present study was to explore sunitinib-induced autophagic effects and the specific molecular mechanisms involved, in vitro, using PC-3 and LNCaP human prostate cancer cell lines. Cells were exposed to escalating doses of sunitinib treatment and subsequent cell viability and cell cycle analyses were performed to evaluate the inhibitory effect of sunitinib in vitro. Immunofluorescence staining of microtubule associated protein 1A/1B-light chain 3 (LC3) puncta was employed to assess autophagy levels after sunitinib treatment. Western blot analysis was performed to evaluate variations in the levels of LC3, sequestosome-1, extracellular signal regulated kinase 1/2 (ERK1/2), mammalian target of rapamycin (mTOR), p70 ribosomal protein S6 kinase (p70S6K) and cleaved caspase-3 proteins. The present study revealed that sunitinib treatment inhibited cell growth and triggered autophagy in a dose-dependent manner in both cell lines. In addition, sunitinib activated ERK1/2 and inhibited mTOR/p70S6K signaling. Sunitinib-induced autophagy was notably reversed by ERK1/2 kinase inhibitor, U0126. Furthermore, inhibition of sunitinib-induced autophagy by 3-methyladenine enhanced apoptosis and exhibited improved cell viability, which indicated that sunitinib induces not only apoptosis but also autophagic cell death in prostate cancer cell lines. These results may lead to an improved understanding of the mechanism of sunitinib's cytotoxic action and may provide evidence that combined sunitinib autophagy-regulating treatment may be of benefit to anti-prostate cancer therapy.