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| | 1. |
2011 Jan 10 |
Attenuation of cyclophosphamide-induced neurotoxicity in rat by yellow dye extract from root of Brimstone tree (Morinda lucida).
Oboh G, Akomolafe TL, Adefegha SA, Adetuyi AO
Exp Toxicol Pathol. 2011 Jan 10; [Epub ahead of print]
Abstract
Cyclophosphamide is an anticancer and immunosuppressant drug that induces reactive oxygen species (ROS) production, so causing malondialdehyde (MDA) production, which is toxic to cells. This study therefore sought to assess the antioxidant and the protective effect of dietary inclusion (0.5 and 1.0%) of yellow dye from root of Brimstone tree (used to enhance the sensory quality of foods and in folk medicine) on cyclophosphamide-induced oxidative stress in brain. Wistar strain albino rats were placed on diet containing 0.5 and 1.0% yellow dye preparation from root of Brimstone tree for 14 days. Intraperitoneal administration of cyclophosphamide (75mg/kg of body weight) 24h before the termination of the experiment caused a significant (P<0.05) increase in the brain malondialdehyde (MDA) content (147.2%) and serum activities of aspartate aminotransferase (AST) (21.7UI/l), alanine amino-transferase (ALT) (29.6UI/l), alkaline phosphatase (43.8UI/l) and total bilirubin (1.7mg/dl). However, there was a significant decrease (P<0.05) in the MDA of content of the brain and serum enzyme activities, in those rats fed diet containing the yellow dye in a dose dependent manner. The inhibition of oxidative stress in brain and serum enzymes and metabolites by the dye could be attributed to its high total phenol content and antioxidant activity as typified by its reducing power, free-radical scavenging ability, Fe(II) chelating ability and inhibition of lipid peroxidation. Therefore, dietary inclusion of the yellow dye from root of Brimstone tree could prevent cyclophosphamide-induced oxidative stress in brain and the associated toxicity to the liver.
[Pubmed: 21227669]
| | 2. |
2011 Dec 14 |
Toxicity of essential and non-essential oils against the chewing louse, Bovicola (Werneckiella) ocellatus.
Talbert R, Wall R
Res Vet Sci. 2011 Dec 14; [Epub ahead of print]
Abstract
The toxicity of six plant essential oils to the chewing louse, Bovicola (Werneckiella) ocellatus collected from donkeys, was examined in laboratory bioassays. The oils examined were: tea-tree (Melaleuca alternifolia), lavender (Lavandula angustifolia), peppermint (Mentha piperita), eucalyptus (Eucalyptus globulus Labillardiere), clove bud (Eugenia caryophyllata) and camphor (Cinnamomum camphora). All except camphor oil showed high levels of toxicity, with significant dose-dependent mortality and an LC(50) at concentrations of below 2% (v/v). Hundred percent mortality was achieved at concentrations of 5-10% (v/v). Two essential oil components: eugenol and (+)-terpinen-4-ol showed similar levels of toxicity. The data suggest that these botanical products may offer environmentally and toxicologically safe, alternative veterinary pediculicides for the control of ectoparasitic lice.
[Pubmed: 22177577]
| | 3. |
2012 May 8 |
Molecular identification of an androgen receptor and its changes in mRNA levels during 17α-methyltestosterone-induced sex reversal in the orange-spotted grouper Epinephelus coioides.
Shi Y, Liu X, Zhang H, Zhang Y, Lu D, Lin H
Comp Biochem Physiol B Biochem Mol Biol. 2012 May 8; [Epub ahead of print]
Abstract
Androgens play a crucial role in sex differentiation, sexual maturation, and spermatogenesis in vertebrates. The action of androgens is mediated via androgen receptors (ARs). The present study reports the cloning of the cDNA sequence of the ar in the orange-spotted grouper, with high expression in testis and relatively low in subdivision of brain areas. The cDNA sequence of ar was 2358bp, encoding a protein of 759 amino acids (aa). Phylogenetic analysis showed that the ar cDNA sequence was closely related to that of threespot wrasse (Halichoeres trimaculatus) and medaka (Oryzias latipes) arβ. As deduced from the phylogenetic tree and the high amino acid identity with the ARβ subtype of other teleosts, grouper ar seems to be more closely related to the beta than the alpha subtype cloned to date. In the first week after 17α-methyltestosterone (MT) implantation, the transcript levels of ar in the hypothalamus declined significantly, and consistently stayed at low level expression to the second week, but increased back to the control levels in the third and fourth week. In the gonad, the mRNA expression of ar was not changed in the first week compared with the control, but increased significantly in the second week, consistently reached the highest level in the third week, dropped slightly but still higher than that of the control in the fourth week. The expression pattern of ar in hypothalamus and gonad during MT-induced sex reversal suggests the involvement of ar in regulating this process in the orange-spotted grouper. The present study provides the data of the changes in the mRNA levels of ar during MT-induced sex reversal in detail to help understand the complicated signals under sex reversal.
[Pubmed: 22580266]
| | 4. |
2012 Apr 1 |
Graviola: A novel promising natural-derived drug that inhibits tumorigenicity and metastasis of pancreatic cancer cells in vitro and in vivo through altering cell metabolism.
Torres MP, Rachagani S, Purohit V, Pandey P, Joshi S, Moore ED, Johansson SL, Singh PK, Ganti AK, Batra SK
Cancer Lett. 2012 Apr 1; [Epub ahead of print]
Abstract
Pancreatic tumors are resistant to conventional chemotherapies. The present study was aimed at evaluating the potential of a novel plant-derived product as a therapeutic agent for pancreatic cancer (PC). The effects of an extract from the tropical tree Annona Muricata, commonly known as Graviola, was evaluated for cytotoxicity, cell metabolism, cancer-associated protein/gene expression, tumorigenicity, and metastatic properties of PC cells. Our experiments revealed that Graviola induced necrosis of PC cells by inhibiting cellular metabolism. The expression of molecules related to hypoxia and glycolysis in PC cells (i.e. HIF-1α, NF-κB, GLUT1, GLUT4, HKII, and LDHA) were downregulated in the presence of the extract. In vitro functional assays further confirmed the inhibition of tumorigenic properties of PC cells. Overall, the compounds that are naturally present in a Graviola extract inhibited multiple signaling pathways that regulate metabolism, cell cycle, survival, and metastatic properties in PC cells. Collectively, alterations in these parameters led to a decrease in tumorigenicity and metastasis of orthotopically implanted pancreatic tumors, indicating promising characteristics of the natural product against this lethal disease.
[Pubmed: 22475682]
| | 5. |
2012 May 2 |
Three centuries of managing introduced conifers in South Africa: Benefits, impacts, changing perceptions and conflict resolution.
van Wilgen BW, Richardson DM
J Environ Manage. 2012 May 2;106C:56-68. Epub 2012 May 2.
Abstract
Alien conifers, mainly pines, have been planted in South Africa for a range of purposes for over 300 years. Formal plantations cover 660 000 ha of the country, and invasive stands of varying density occur on a further 2.9 million ha. These trees have brought many benefits but have also caused unintended problems. The management of alien conifers has evolved in response to emerging problems such as excessive water use by plantations of conifers, changing values and markets, and the realities of a new ecological order brought about by invasive alien conifers. This paper reviews the history of conifer introductions to South Africa, the benefits and impacts with which they are associated, and the ongoing and evolving research that has been conducted to inform their management. The South African approach has included taking courageous steps to address the problem of highly invasive species that are also an important commercial crop. These interventions have not, however, had the desired effect of both retaining benefits from formal plantations while simultaneously reversing the trend of growing impacts associated with self-sown invasive stands. We suggest that different approaches need to be considered, including the systematic phasing out of commercial forestry in zones where it delivers low returns, and the introduction of more effective, focussed and integrated, region-specific approaches to the management of invasive stands of conifers. These steps would deliver much improved economic outcomes by protecting valuable ecosystem services, but will require political commitment to policies that could be unpopular in certain sectors of society.
[Pubmed: 22562012]
| | 6. |
2012 Mar 14 |
A Study of Air Pollution with Heavy Metals in Athens City and Attica Basin Using Evergreen Trees as Biological Indicators.
Sawidis T, Krystallidis P, Veros D, Chettri M
Biol Trace Elem Res. 2012 Mar 14; [Epub ahead of print]
Abstract
Concentrations of five metals (cadmium, chromium, copper, nickel and lead) were determined in tree leaves collected from 13 areas of the Attica basin and Athens city, Greece. Geographical distribution patterns were investigated, and factors affecting toxic element accumulation in trees were discussed. The mean heavy metal content in the tree leaves is described in the descending order of copper > lead > nickel > chromium > cadmium. Generally, the most damaged areas have been proved to be those near the city center and in the vicinity of the Attica highway. The geomorphological relief of the area plays an important role in the dispersion of airborne particles from pollution sources to the surrounding area. Areas on the NE region are also polluted mainly due to wind directions. In Citrus aurantium leaves, with relatively impermeable cuticle, high chromium, copper and nickel concentration would be possibly caused only by significant stomatal uptake. The conifer tree Pinus brutia providing a rough leaf surface also showed elevated concentrations, especially of cadmium and lead. The thick waxy cuticle of the sclerophyllous broadleaved Olea europaea forms a smooth sheet increasing the barrier properties of the leaf epidermis and causing a reduction in leaf permeability. The dense trichomes of the abaxial epidermis of Olea europaea also act as a pollution screen keeping away the air particles from the epidermis stomata. The presence of a certain metal within the leaf cells could reduce the uptake or toxicity of some others.
[Pubmed: 22410948]
| | 7. |
2012 Mar 30 |
Complete mitochondrial genome of Membranipora grandicella (Bryozoa: Cheilostomatida) determined with next-generation sequencing: The first representative of the suborder Malacostegina.
Shen X, Tian M, Meng X, Liu H, Cheng H, Zhu C, Zhao F
Comp Biochem Physiol Part D Genomics Proteomics. 2012 Mar 30; [Epub ahead of print]
Abstract
Next-generation sequencing (NGS) has proven a valuable platform for fast and easy obtaining of large numbers of sequences at relatively low cost. In this study we use shot-gun sequencing method on Illumina HiSeq 2000, to obtain enough sequences for the assembly of the bryozoan Membranipora grandicella (Bryozoa: Cheilostomatida) mitochondrial genome, which is the first representative of the suborder Malacostegina. The complete mitochondrial genome is 15,861bp in length, which is relatively larger than other studied bryozoans. The mitochondrial genome contains 13 protein-coding genes, 2 ribosomal RNAs and 20 transfer RNAs. To investigate the phylogenetic position and the inner relationships of the phylum Bryozoa, phylogenetic trees were constructed with amino acid sequences of 11 PCGs from 30 metazoans. Two superclades of protostomes, namely Lophotrochozoa and Ecdysozoa, are recovered as monophyletic with strong support in both ML and Bayesian analyses. Somewhat to surprise, Bryozoa appears as the sister group of Chaetognatha with moderate or high support. The relationship among five bryozoans is Tubulipora flabellaris+(M. grandicella+(Flustrellidra hispida+(Bugula neritina+Watersipora subtorquata))), which supports for the view that Cheilostomatida is not a natural, monophyletic clade. NGS proved to be a quick and easy method for sequencing a complete mitochondrial genome.
[Pubmed: 22503287]
| | 8. |
2011 May 04 |
Applying data mining techniques to explore factors contributing to occupational injuries in Taiwan's construction industry.
Cheng CW, Leu SS, Cheng YM, Wu TC, Lin CC
Accid Anal Prev. 2012 Sep;48:214-22. Epub 2011 May 04.
Abstract
Construction accident research involves the systematic sorting, classification, and encoding of comprehensive databases of injuries and fatalities. The present study explores the causes and distribution of occupational accidents in the Taiwan construction industry by analyzing such a database using the data mining method known as classification and regression tree (CART). Utilizing a database of 1542 accident cases during the period 2000-2009, the study seeks to establish potential cause-and-effect relationships regarding serious occupational accidents in the industry. The results of this study show that the occurrence rules for falls and collapses in both public and private project construction industries serve as key factors to predict the occurrence of occupational injuries. The results of the study provide a framework for improving the safety practices and training programs that are essential to protecting construction workers from occasional or unexpected accidents.
[Pubmed: 22664684]
| | 9. |
2012 Jun 1 |
Correlation Between Populations of Rhodnius and Presence of Palm Trees as Risk Factors for the Emergence of Chagas Disease in Amazon Region, Brazil.
Ricardo-Silva AH, Lopes CM, Ramos LB, Marques WA, Mello CB, Duarte R, Fuente AL, Toma HK, Reboredo-Oliveira L, Kikuchi SA, Baptista TF, Santos-Mallet JR, Junqueira AC, Gonçalves TC
Acta Trop. 2012 Jun 1; [Epub ahead of print]
Abstract
Among the states that comprise the legally defined Amazon Region of Brazil, Pará has presented the highest occurrences of acute cases of Chagas disease over the last two decades. These cases have been attributed to consumption of fruits from native palm trees. In surveys in rural and wild areas of the municipality of Oriximiná, Pará, triatomine fauna, their main ecotopes and the infection rate due to Trypanosoma cruzi were identified using active and passive search methods: manual capture and Noireau traps, respectively. A total of 582 ecotopes were surveyed using 1496 Noireau traps. Out of 442 specimens collected, 289 were identified as Rhodnius robustus and 153 as Rhodnius pictipes. The infection rate caused by Trypanosoma cruzi was 17.4%. The food sources of the triatomines were found to be birds, hemolymph, horses and rodents. The association between R. robustus and inajá palm trees (Attalea marita), which are abundant in rural areas, was confirmed. On the other hand, R. pictipes is found in several palm tree species, such as inajá (Attalea marita), mucajá (Acrocomia aculeata), murumuru (Astrocaryum murumuru) and patauá (Oenocarpus bataua), and in bromeliads in wild areas. These occurrences of triatomine species in regions with or without Trypanosoma cruzi infection, in the vicinity of the main settlement of the municipality, suggest that there is a need for entomological and epidemiological surveillance in this region.
[Pubmed: 22664419]
| | 10. |
2011 Nov 17 |
Application of STR markers in wildlife forensic casework involving Australian black-cockatoos (Calyptorhynchus spp.).
White NE, Dawson R, Coghlan ML, Tridico SR, Mawson PR, Haile J, Bunce M
Forensic Sci Int Genet. 2011 Nov 17; [Epub ahead of print]
Abstract
Parrots and cockatoos are highly prized aviary birds and the demands for such species has fuelled their illegal trade and harvest from the wild. Here we report on three forensic case studies involving black-cockatoos (Calyptorhynchus spp.) endemic to Australia. These cases involve suspected poaching and illegal killing of endangered red- and white-tailed black-cockatoos. Through the prior development of 20 polymorphic microsatellite loci and population databases for white- and red-tailed black-cockatoos, the tools are available to conduct high-resolution paternity and individual identity testing. In one case, we matched a red-tailed black-cockatoo nestling to a tree hollow from which it was poached through the use of DNA from eggshell recovered from the nest. For the second case, we utilized our provenance population database (nest sites), and identified the kinship and geographic origin of a white-tailed black-cockatoo, which was illegally harvested from the wild. The third case determined the number individual white-tailed black-cockatoos allegedly shot at a fruit grower's orchard from body part remains. These genetic investigations highlight the significance and statistical confidence of DNA profiling and associated databases for endangered taxa, such as exotic birds. Our cockatoo population databases are the first of their kind in Australia, and demonstrate the efficacy of such approaches to identify such illegal activity. With a robust set of genetic markers and methodologies in place, we aim to broaden our population databases to include other cockatoo species of conservation concern.
[Pubmed: 22101117]
| | 11. |
2012 May 15 |
Using native epiphytic ferns to estimate the atmospheric mercury levels in a small-scale gold mining area of West Java, Indonesia.
Kono Y, Rahajoe JS, Hidayati N, Kodamatani H, Tomiyasu T
Chemosphere. 2012 May 15; [Epub ahead of print]
Abstract
Mercury pollution is caused by artisanal and small-scale gold mining (ASGM) operations along the Cikaniki River (West Java, Indonesia). The atmosphere is one of the primary media through which mercury can disperse. In this study, atmospheric mercury levels are estimated using the native epiphytic fern Asplenium nidus complex (A. nidus) as a biomonitor; these estimates shed light on the atmospheric dispersion of mercury released during mining. Samples were collected from 8 sites along the Cikaniki Basin during September-November, 2008 and September-November, 2009. The A. nidus fronds that were attached to tree trunks 1-3m above the ground were collected and measured for total mercury concentration using cold vapor atomic absorption spectrometry (CVAAS) after acid-digestion. The atmospheric mercury was collected using porous gold collectors, and the concentrations were determined using double-amalgam CVAAS. The highest atmospheric mercury concentration, 1.8×10(3)±1.6×10(3)ngm(-3), was observed at the mining hot spot, and the lowest concentration of mercury, 5.6±2.0ngm(-3), was observed at the remote site from the Cikaniki River in 2009. The mercury concentrations in A. nidus were higher at the mining village (5.4×10(3)±1.6×10(3)ngg(-1)) than at the remote site (70±30ngg(-1)). The distribution of mercury in A. nidus was similar to that in the atmosphere; a significant correlation was observed between the mercury concentrations in the air and in A. nidus (r=0.895, P<0.001, n=14). The mercury levels in the atmosphere can be estimated from the mercury concentration in A. nidus using a regression equation: log (Hg(A.nidu)/ngg(-1))=0.740 log (Hg(Air)/ngm(-3)) - 1.324.
[Pubmed: 22595529]
| | 12. |
2012 Mar 10 |
Ozone visible symptoms and reduced root biomass in the subalpine species Pinus uncinata after two years of free-air ozone fumigation.
Díaz-de-Quijano M, Schaub M, Bassin S, Volk M, Peñuelas J
Environ Pollut. 2012 Mar 10; [Epub ahead of print]
Abstract
Concentrations of ozone often exceed the thresholds of forest protection in the Pyrenees, but the effect of ozone on Pinus uncinata, the dominant species in subalpine forests in this mountainous range, has not yet been studied. We conducted an experiment of free-air ozone fumigation with saplings of P. uncinata fumigated with ambient O(3) (AOT40 May-Oct: 9.2 ppm h), 1.5 × O(3amb) (AOT40 May-Oct: 19.2 ppm h), and 1.8 × O(3amb) (AOT40 May-Oct: 32.5 ppm h) during two growing seasons. We measured chlorophyll content and fluorescence, visible injury, gas exchange, and above- and below-ground biomass. Increased exposures to ozone led to a higher occurrence and intensity of visible injury from O(3) and a 24-29% reduction of root biomass, which may render trees more susceptible to other stresses such as drought. P. uncinata is thus a species sensitive to O(3), concentrations of which in the Pyrenees are already likely affecting this species.
[Pubmed: 22410242]
| | 13. |
2012 Jun 15 |
Responses of fungal and plant communities to partial humus removal in mid-boreal N-enriched forests.
Tarvainen O, Hamberg L, Ohenoja E, Strömmer R, Markkola A
J. Environ. Manage. 2012 Oct 15;108:120-9. Epub 2012 Jun 15.
Abstract
Partial removal of the forest humus layer was performed in nitrogen-enriched urban Scots pine forest stands in the northern Finland in order to improve soil conditions for ectomycorrhizal (ECM) fungi, important symbionts of trees. Aboveground part of understory vegetation and the uppermost half of the humus layer were removed (REMOVAL treatment) from sample plots in six urban and eight rural reference forest sites at the beginning of the 2001 growing season. During the seasons 2001-2005, we inventoried sporocarp production of ECM and saprophytic fungi, and in 2003 the recovery of understory vegetation. The REMOVAL treatment resulted in a higher number of fruiting ECM species and sporocarps than controls at the rural, but not at urban sites. The sporocarp number of saprophytic fungi declined in the REMOVAL subplots at the urban sites. The recovery of bryophytes and lichens in the REMOVAL treatment was slow at both the urban and rural sites, whereas Vaccinium dwarf shrub cover, and herb and grass cover returned rapidly at the urban sites. We conclude that the partial vegetation and humus layer removal as a tool to promote the reproduction of ECM fungal species is limited in the boreal urban forests.
[Pubmed: 22705763]
| | 14. |
2013 |
Mangiferin and its traversal into the brain.
Zajac D, Stasinska A, Delgado R, Pokorski M
Adv. Exp. Med. Biol. 2013;756:105-11.
Abstract
Mangiferin, the main active substance of the mango tree bark (Mangifera indica L.), is known for its use in natural medicine, not only as a health enhancing panacea or adjunct therapeutic, but also for brain functions improvement. In this context, we deemed it worthwhile to establish whether mangiferin could traverse into the brain after systemic administration; an essential piece of information for the rational use of a compound as a neurotherapeutic, remaining so far inconclusive regarding mangiferin. We addressed this issue by studying recoverability of mangiferin in membrane and cytosolic fractions of rat brain homogenates after its intraperitoneal administration in a dose of 300 mg/kg. We used three preparations of mangiferin of decreasing purity to find out whether its penetration to the brain could have to do with the possible presence of contaminants. The qualitative methods of thin-layered-chromatography and UV/VIS spectrophotometry were employed in this study. The results were clearly negative, as we failed to trace mangiferin in the brain fractions with either method, which makes it unlikely that the compound traverse the blood-brain barrier after being systemically administered. We conclude that it is improbable that mangiferin could act via direct interaction with central neural components, but rather has peripheral, target specific functions which could be secondarily reflected in brain metabolism.
[Pubmed: 22836625]
| | 15. |
2012 Apr 18 |
Selective vulnerability of synaptic signaling and metabolism to nitrosative stress.
Mongin AA, Dohare P, Jourd'heuil D
Antioxid. Redox Signal. 2012 Oct 1;17(7):992-1012. Epub 2012 Apr 18.
Abstract
Abstract Significance: Nitric oxide (NO) plays diverse physiological roles in the central nervous system, where it modulates neuronal communication, regulates blood flow, and contributes to the innate immune responses. In a number of brain pathologies, the excessive production of NO also leads to the formation of reactive and toxic intermediates generically termed reactive nitrogen species (RNS). RNS cause irreversible or poorly reversible damage to brain cells. Recent Advances: Recent work in the field focused on the ability of NO and RNS to yield protein modifications, including the S-nitrosation of cysteine residues, which, in many instances, impact cellular functions and viability. Critical Issues: The vast majority of neuropathological studies focus on the loss of cell viability, but nitrosative stress may also strongly impair the functions of neuronal processes: axonal projections and dendritic trees. The functional integrity of axons and dendrites critically depends on local metabolism and effective delivery of metabolic enzymes and organelles. Here, we summarize the existing literature describing the effects of nitrosative stress on the major pathways of energetic metabolism: glycolysis, tricarboxylic acid cycle, and mitochondrial respiration, with the emphasis on modifications of protein thiols. Future Directions: We propose that axons and dendrites are highly vulnerable to nitrosative stress because of their low glycolytic capacity and high dependence on timely delivery of metabolic enzymes and organelles from the cell body. Thus, supplementation with the end products of glycolysis, pyruvate or lactate, may help preserve metabolism in distal neuronal processes and protect or restore synaptic function in the ailing brain. Antioxid. Redox Signal. 17, 992-1012.
[Pubmed: 22339371]
| | 16. |
2012 Feb 15 |
Ozone deposition to an orange orchard: Partitioning between stomatal and non-stomatal sinks.
Fares S, Weber R, Park JH, Gentner D, Karlik J, Goldstein AH
Environ. Pollut. 2012 Oct;169:258-66. Epub 2012 Feb 15.
Abstract
Orange trees are widely cultivated in regions with high concentrations of tropospheric ozone. Citrus absorb ozone through their stomata and emit volatile organic compounds (VOC), which, together with soil emissions of NO, contribute to non-stomatal ozone removal. In a Valencia orange orchard in Exeter, California, we used fast sensors and eddy covariance to characterize water and ozone fluxes. We also measured meteorological parameters necessary to model other important sinks of ozone deposition. We present changes in magnitude of these ozone deposition sinks over the year in response to environmental parameters. Within the plant canopy, the orchard constitutes a sink for ozone, with non-stomatal ozone deposition larger than stomatal uptake. In particular, soil deposition and reactions between ozone, VOC and NO represented the major sinks of ozone. This research aims to help the development of metrics for ozone-risk assessment and advance our understanding of citrus in biosphere-atmosphere exchange.
[Pubmed: 22341155]
| | 17. |
2012 May 02 |
The evolution of tachykinin/tachykinin receptor (TAC/TACR) in vertebrates and molecular identification of the TAC3/TACR3 system in zebrafish (Danio rerio).
Zhou W, Li S, Liu Y, Qi X, Chen H, Cheng CH, Liu X, Zhang Y, Lin H
Mol. Cell. Endocrinol. 2012 Sep 25;361(1-2):202-12. Epub 2012 May 02.
Abstract
Tachykinins are a family of peptides that are conserved from invertebrates to mammals. However, little is known about the evolutionary history of tachykinin (TAC) and tachykinin receptor (TACR) genes in vertebrates, especially in the teleost group. In the present study, five TACs and six TACRs genes were identified in the zebrafish genome. Genomic synteny analysis and phylogenetic tree analysis indicate that the increased numbers of TAC and TACR genes in vertebrates are the result of both genome duplications and local individual gene duplication. The full-length cDNA sequences encoding multiple TAC3s (TAC3a and TAC3b) and TACR3s (TACR3a1, TACR3a2 and TACR3b) were subsequently cloned from zebrafish brain samples. Sequence analysis suggested that four putative neurokinin B (NKB)-like peptides (NKBa-13, NKBa-10, NKBb-13 and NKBb-11) might be generated by the processing of two zebrafish TAC3 precursors. Tissue distribution studies in zebrafish revealed that TAC3 and TACR3 are mainly expressed in the brain regions. The biological activities of four zebrafish NKB peptides and three TACR3s were further examined using transcription reporter assays in cultured eukaryotic cells. All the synthetic NKB peptides were able to evoke the downstream signaling events of TACR3s with the exception of NKBb-11. These results indicated that the multiple TAC/TACR genes identified in vertebrates evolved from gene duplication events and that the TAC3/TACR3 systems also operate in the teleost group.
[Pubmed: 22580006]
| | 18. |
2012 Jun 15 |
Interspecies correlation for neutrally evolving traits.
Sagitov S, Bartoszek K
J. Theor. Biol. 2012 Sep 21;309:11-9. Epub 2012 Jun 15.
Abstract
A simple way to model phenotypic evolution is to assume that after splitting, the trait values of the sister species diverge as independent Brownian motions. Relying only on a prior distribution for the underlying species tree (conditioned on the number, n, of extant species) we study the random vector (X(1),…,X(n)) of the observed trait values. In this paper we derive compact formulae for the variance of the sample mean and the mean of the sample variance for the vector (X(1),…,X(n)). The key ingredient of these formulae is the correlation coefficient between two trait values randomly chosen from (X(1),…,X(n)). This interspecies correlation coefficient takes into account not only variation due to the random sampling of two species out of n and the stochastic nature of Brownian motion but also the uncertainty in the phylogenetic tree. The latter is modeled by a (supercritical or critical) conditioned branching process. In the critical case we modify the Aldous-Popovic model by assuming a proper prior for the time of origin.
[Pubmed: 22706152]
| | 19. |
2012 Apr 04 |
Synchrotron-based dynamic computed tomography of tissue motion for regional lung function measurement.
Dubsky S, Hooper SB, Siu KK, Fouras A
J R Soc Interface. 2012 Sep 7;9(74):2213-24. Epub 2012 Apr 04.
Abstract
During breathing, lung inflation is a dynamic process involving a balance of mechanical factors, including trans-pulmonary pressure gradients, tissue compliance and airway resistance. Current techniques lack the capacity for dynamic measurement of ventilation in vivo at sufficient spatial and temporal resolution to allow the spatio-temporal patterns of ventilation to be precisely defined. As a result, little is known of the regional dynamics of lung inflation, in either health or disease. Using fast synchrotron-based imaging (up to 60 frames s(-1)), we have combined dynamic computed tomography (CT) with cross-correlation velocimetry to measure regional time constants and expansion within the mammalian lung in vivo. Additionally, our new technique provides estimation of the airflow distribution throughout the bronchial tree during the ventilation cycle. Measurements of lung expansion and airflow in mice and rabbit pups are shown to agree with independent measures. The ability to measure lung function at a regional level will provide invaluable information for studies into normal and pathological lung dynamics, and may provide new pathways for diagnosis of regional lung diseases. Although proof-of-concept data were acquired on a synchrotron, the methodology developed potentially lends itself to clinical CT scanning and therefore offers translational research opportunities.
[Pubmed: 22491972]
| | 20. |
2012 Mar 21 |
Dynamics of angiogenesis during murine retinal development: a coupled in vivo and in silico study.
Watson MG, McDougall SR, Chaplain MA, Devlin AH, Mitchell CA
J R Soc Interface. 2012 Sep 7;9(74):2351-64. Epub 2012 Mar 21.
Abstract
The manner in which the superficial retinal vascular plexus (RVP) develops in neonatal wild-type mice is relatively well documented and poses an interesting challenge to the mathematical modelling community. Prior to birth, astrocyte sprouting and proliferation begin around the edge of the optic nerve head, and subsequent astrocyte migration in response to a chemotactic gradient of platelet-derived growth factor (PDGF)-A results in the formation of a dense scaffold on the surface of the inner retina. Astrocytes express a variety of chemotactic and haptotactic proteins that subsequently induce endothelial cell sprouting and modulate growth of the RVP. An experimentally informed, two-dimensional hybrid partial differential equation-discrete model is derived to track the outward migration of individual astrocyte and endothelial tip cells in response to the appropriate biochemical cues. Blood perfusion is included throughout the development of the plexus, and the evolving retinal trees are allowed to adapt and remodel by means of several biological stimuli. The resulting wild-type in silico RVP structures are compared with corresponding experimental whole mounts taken at various stages of development, and agreement between the respective vascular morphologies is found to be excellent. Subsequent numerical predictions help elucidate some of the key biological processes underlying retinal development and demonstrate the potential of the virtual retina for the investigation of various vascular-related diseases of the eye.
[Pubmed: 22438490]
| | 21. |
2012 May 26 |
Possible use of heterospecific food-associated calls of macaques by sika deer for foraging efficiency.
Koda H
Behav. Processes. 2012 Sep;91(1):30-4. Epub 2012 May 26.
Abstract
Heterospecific communication signals sometimes convey relevant information for animal survival. For example, animals use or eavesdrop on heterospecific alarm calls concerning common predators. Indeed, most observations have been reported regarding anti-predator strategies. Use of heterospecific signals has rarely been observed as part of a foraging strategy. Here, I report empirical evidence, collected using playback experiments, showing that Japanese sika deer, Cevus nippon, use heterospecific food calls of Japanese macaques, Macaca fuscata yakui, for foraging efficiency. The deer and macaques both inhabit the wild forest of Yakushima Island with high population densities and share many food items. Anecdotal observations suggest that deer often wait to browse fruit falls under the tree where a macaque group is foraging. Furthermore, macaques frequently produce food calls during their foraging. If deer effectively obtain fruit from the leftovers of macaques, browsing fruit fall would provide a potential benefit to the deer, and, further, deer are likely to associate macaque food calls with feeding activity. The results showed that playback of macaque food calls under trees gathered significantly more deer than silence control periods. These results suggest that deer can associate macaque food calls with foraging activities and use heterospecific calls for foraging efficiency.
[Pubmed: 22641112]
| | 22. |
2012 May 01 |
Evolution and diversification of Group 1 [NiFe] hydrogenases. Is there a phylogenetic marker for O(2)-tolerance?
Pandelia ME, Lubitz W, Nitschke W
Biochim. Biophys. Acta. 2012 Sep;1817(9):1565-75. Epub 2012 May 01.
Abstract
Group 1 hydrogenases are periplasmic enzymes and are thus strongly affected by the "outside world" the cell experiences. This exposure has brought about an extensive heterogeneity in their cofactors and redox partners. Whereas in their majority they are very O(2)-sensitive, several enzymes of this group have been recently reported to be O(2)-tolerant. Structural and biochemical studies have shown that this O(2)-tolerance is conferred by the presence of an unusual iron-sulfur cofactor with supernumerary cysteine ligation (6 instead of 4 Cys, hence called '6C cluster'). This atypical cluster coordination affords redox plasticity (i.e. two-redox transitions), unprecedented for this type of cofactors and likely involved in resistance to O(2). Genomic screening and phylogenetic tree reconstruction revealed that 6C hydrogenases form a monophyletic clade and are unexpectedly widespread among bacteria. However, several other well-defined clades are observed, which indicate early diversification of the enzyme into different subfamilies. The various idiosyncrasies thereof are shown to comply with a very simple rule: phylogenetic grouping of hydrogenases directly correlates with their specific functions and hence biochemical characteristics. The observed variability results from gene duplication, gene shuffling and subsequent adaptation of the diversified enzymes to specific environments. An important factor for this diversification seems to have been the emergence of molecular oxygen. Hydrogenases appear to have dealt with oxidative stress in various ways, the most successful of which, however, was the innovation of the 6C-cluster conferring pronounced O(2)-tolerance to the parent enzymes.
[Pubmed: 22588050]
| | 23. |
2012 May 30 |
Influence of particle size on performance of a pilot-scale fixed-bed gasification system.
Yin R, Liu R, Wu J, Wu X, Sun C, Wu C
Bioresour. Technol. 2012 Sep;119:15-21. Epub 2012 May 30.
Abstract
The effect of particle size on the gasification performance of a pilot-scale (25kg/h) downdraft fixed bed gasification system was investigated using prunings from peach trees at five different size fractions (below 1, 1-2, 2-4, 4-6 and 6-8cm). The gas and hydrocarbon compositions were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS), respectively. With increasing particle size, gas yield increased while tar and dust content decreased. The lower heating value of the gas decreased slightly with particle size. At a smaller particle size, more hydrocarbons were detected in the producer gas. Hydrogen and carbon dioxide contents increased with the decrease in particle size, reaching 16.09% and 14.36% at particle size below 1cm, respectively. Prunings with a particle size of 1-2cm were favorable for gasification in the downdraft gasifier used in this study.
[Pubmed: 22728176]
| | 24. |
2011 Sep 16 |
Discovery of serum protein biomarkers in rheumatoid arthritis using MALDI-TOF-MS combined with magnetic beads.
Zhang X, Yuan Z, Shen B, Zhu M, Liu C, Xu W
Clin. Exp. Med. 2012 Sep;12(3):145-51. Epub 2011 Sep 16.
Abstract
The aim of this study was to discover potential biomarkers for rheumatoid arthritis (RA) using Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry combined with magnetic beads. Proteomic fingerprint technology combining magnetic beads with MALDI-TOF-MS was used to profile and compare the proteomes in serum samples from 60 patients with RA, 35 patients with osteoarthritis and 36 healthy controls. The proteomic pattern associated with RA was identified by Biomarker Patterns Software. Model of biomarkers was constructed and evaluated through the Biomarker Patterns Software. A total of 33 discriminative peaks were identified to be related with RA, in which the 5 peaks with the mass-charge ratio (m/z) peaks at 15,715.5, 7,771.4, 8,959.4, 8,469.8 and 8,710.8 Da were used to construct a model for the diagnosis of RA by pattern recognition software. The blind testing data indicated a sensitivity of 86.7% and a specificity of 90.0% in RA diagnosis. These results demonstrated that potential protein biomarkers for RA could be discovered in serum by MALDI-TOF-MS combined with WCX magnetic beads. The diagnosis mode tree based on the five candidate biomarkers could provide a powerful and reliable diagnostic method for RA with high sensitivity and specificity.
[Pubmed: 21922190]
| | 25. |
2012 May 27 |
Retinal image analysis aimed at blood vessel tree segmentation and early detection of neural-layer deterioration.
Jan J, Odstrcilik J, Gazarek J, Kolar R
Comput Med Imaging Graph. 2012 Sep;36(6):431-41. Epub 2012 May 27.
Abstract
An automatic method of segmenting the retinal vessel tree and estimating status of retinal neural fibre layer (NFL) from high resolution fundus camera images is presented. First, reliable blood vessel segmentation, using 2D directional matched filtering, enables to remove areas occluded by blood vessels thus leaving remaining retinal area available to the following NFL detection. The local existence of rather faint and hardly visible NFL is detected by combining several newly designed local textural features, sensitive to subtle NFL characteristics, into feature vectors submitted to a trained neural-network classifier. Obtained binary retinal maps of NFL distribution show a good agreement with both medical expert evaluations and quantitative results obtained by optical coherence tomography.
[Pubmed: 22640597]
| | 26. |
2012 Jun 21 |
Endoscopic retrograde cholangiopancreatography complications in the era of cholangioscopy: Is there an increased risk?
Hammerle CW, Haider S, Chung M, Pandey A, Smith I, Kahaleh M, Sauer BG
Dig Liver Dis. 2012 Sep;44(9):754-8. Epub 2012 Jun 21.
Abstract
Single-operator cholangioscopy allows direct visualization of the biliary tree and is being used in the diagnosis and treatment of various biliary conditions. To date, there are few data examining complications of single-operator cholangioscopy.
[Pubmed: 22727634]
| | 27. |
2012 Jul 08 |
Roots and fungi accelerate carbon and nitrogen cycling in forests exposed to elevated CO(2).
Phillips RP, Meier IC, Bernhardt ES, Grandy AS, Wickings K, Finzi AC, Knops J
Ecol. Lett. 2012 Sep;15(9):1042-9. Epub 2012 Jul 08.
Abstract
A common finding in multiple CO(2) enrichment experiments in forests is the lack of soil carbon (C) accumulation owing to microbial priming of 'old' soil organic matter (SOM). However, soil C losses may also result from the accelerated turnover of 'young' microbial tissues that are rich in nitrogen (N) relative to bulk SOM. We measured root-induced changes in soil C dynamics in a pine forest exposed to elevated CO(2) and N enrichment by combining stable isotope analyses, molecular characterisations of SOM and microbial assays. We find strong evidence that the accelerated turnover of root-derived C under elevated CO(2) is sufficient in magnitude to offset increased belowground inputs. In addition, the C losses were associated with accelerated N cycling, suggesting that trees exposed to elevated CO(2) not only enhance N availability by stimulating microbial decomposition of SOM via priming but also increase the rate at which N cycles through microbial pools.
[Pubmed: 22776588]
| | 28. |
2012 Jul 05 |
Evidence for intersexual chemical mimicry in a dioecious plant.
Soler CC, Proffit M, Bessière JM, Hossaert-McKey M, Schatz B, Irwin R
Ecol. Lett. 2012 Sep;15(9):978-85. Epub 2012 Jul 05.
Abstract
The dioecious Mediterranean fig, Ficus carica, displays a unique phenology in which males sometimes bloom synchronously with females (in summer), and sometimes not (in spring). Ficus carica is engaged in an obligatory mutualism with a specific pollinating wasp, which reproduces only within figs, localising them by their specific scents. We show that scents emitted by male figs show seasonal variation within individual trees. Scents of summer male figs resemble those of the co-flowering females, and are different from those of the same male trees in spring, when female figs are absent. These differences hold even if only compounds electrophysiologically active for pollinators are considered. The similar scents of summer males and females may explain why the rewardless females are still pollinated. These results offer a tractable model for future studies of intersexual chemical mimicry in mutualistic pollination interactions.
[Pubmed: 22762353]
| | 29. |
2012 Jun 13 |
Contrasting leaf chemical traits in tropical lianas and trees: implications for future forest composition.
Asner GP, Martin RE, Penuelas J
Ecol. Lett. 2012 Sep;15(9):1001-7. Epub 2012 Jun 13.
Abstract
Lianas are an important growthform in tropical forests, and liana abundance and biomass may be increasing in some regions. Explanations for liana proliferation hinge upon physiological responses to changing resource conditions that would favour them over trees. Testing a chemical basis for such responses, we assessed 22 foliar traits in 778 lianas and 6496 trees at 48 tropical forest sites. Growthform differences in chemical allocation occurred on a leaf mass and area basis. Light capture-growth and maintenance-metabolism chemicals averaged 14.5 and 16.7% higher mass-based concentration in lianas than in trees globally, whereas structure and defence chemicals averaged 9.0% lower in lianas. Relative differences in chemical allocation by lianas and trees were mediated by climate with peak differences at about 2500 mm year(-1) and 25 °C. Differences in chemical traits suggest that liana expansion could be greatest in forests undergoing increased canopy-level irradiance via disturbance and climate change.
[Pubmed: 22690783]
| | 30. |
2012 May 18 |
Effects of elevated carbon dioxide and nitrogen addition on foliar stoichiometry of nitrogen and phosphorus of five tree species in subtropical model forest ecosystems.
Huang W, Zhou G, Liu J, Zhang D, Xu Z, Liu S
Environ. Pollut. 2012 Sep;168:113-20. Epub 2012 May 18.
Abstract
The effects of elevated carbon dioxide (CO2) and nitrogen (N) addition on foliar N and phosphorus (P) stoichiometry were investigated in five native tree species (four non-N2 fixers and one N2 fixer) in open-top chambers in southern China from 2005 to 2009. The high foliar N:P ratios induced by high foliar N and low foliar P indicate that plants may be more limited by P than by N. The changes in foliar N:P ratios were largely determined by P dynamics rather than N under both elevated CO2 and N addition. Foliar N:P ratios in the non-N2 fixers showed some negative responses to elevated CO2, while N addition reduced foliar N:P ratios in the N2 fixer. The results suggest that N addition would facilitate the N2 fixer rather than the non-N2 fixers to regulate the stoichiometric balance under elevated CO2.
[Pubmed: 22609862]
| | 31. |
2012 Aug |
Current status of percutaneous coronary intervention of chronic total occlusion
Ge
J Zhejiang Univ Sci B 2012 Aug;13(8):589-602.
Abstract
This paper describes the current status of percutaneous coronary intervention (PCI) for totally occluded coronary arteries. Chronic total occlusion is associated with 10%–20% of all PCI procedures. Results show that opening an occluded vessel, especially one supplying a considerable area of myocardium, may be beneficial for a patient’s angina relief and heart function. We describe the devices used currently in re-canalization such as new wires, microcatheters (including Tonus and Cosair) and intravascular ultrasound guidance. Different techniques to improve the success rate and reduce complications are discussed in detail.
[Pubmed: 22843178]
| | 32. |
2012 Aug |
Introducing the At-Risk Average Causal Effect with Application to HealthWise South Africa
Coffman, Caldwell, Smith
Prev Sci 2012 Aug;13(4):437-447.
Abstract
Researchers often hypothesize that a causal variable, whether randomly assigned or not, has an effect on an outcome behavior and that this effect may vary across levels of initial risk of engaging in the outcome behavior. In this paper, we propose a method for quantifying initial risk status. We then illustrate the use of this risk-status variable as a moderator of the causal effect of leisure boredom, a non-randomized continuous variable, on cigarette smoking initiation. The data come from the HealthWise South Africa study. We define the causal effects using marginal structural models and estimate the causal effects using inverse propensity weights. Indeed, we found leisure boredom had a differential causal effect on smoking initiation across different risk statuses. The proposed method may be useful for prevention scientists evaluating causal effects that may vary across levels of initial risk.
[Pubmed: 22477557]
| | 33. |
2012 Aug |
shutdown is a component of the Drosophila piRNA biogenesis machinery
Preall, Czech, Guzzardo, Muerdter, Hannon
RNA 2012 Aug;18(8):1446-1457.
Abstract
In animals, the piRNA pathway preserves the integrity of gametic genomes, guarding them against the activity of mobile genetic elements. Here, the authors link shutdown, a gene previously shown to be required for fertility in Drosophila, to the piRNA pathway. Analysis of knockdown phenotypes in both the germline and somatic compartments of the ovary demonstrate important roles for shutdown in both primary biogenesis and the ping-pong cycle, a piRNA amplification loop. shutdown is a member of the FKBP family of immunophilins, with domains implicated in peptidyl-prolyl cis-trans isomerase activity and in the binding of HSP90-family chaperones.
[Pubmed: 22753781]
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