bluuebunny/crossref_metadata_2025 huggingface dataset:
How do hydromorphological constraints and regulated flows govern macroinvertebrate communities along an entire lowland river?
Authors: Guareschi S. , Laini A. , Racchetti E. , Bo T. , Fenoglio S. , Bartoli M.
Published: December 2012

Macroinvertebrates' response to hydromorphological alterations and regulated flows along lowland rivers is still poorly known despite ecohydrology's fundamental role in river science. Along the Oglio River (Northern Italy), several water abstractions and dams break it into segments with varying hydraulic and morphological properties. Three types of a priori different environments were identified (dammed, downstream and free flowing sections), and macroinvertebrate communities were sampled from each zone. This study aimed (i) to investigate patterns of macroinvertebrate communities along a regulated lowland river by testing the a priori zones; (ii) to find macroinvertebrate taxa that served as indicators of the various hydrological conditions and (iii) to verify hydromorphological control over ecological macroinvertebrate traits resulting in different trait values in each identified zone. Macroinvertebrate community was characterized in a total of 63 stations by means of two quantitative approaches, each exploring a surface of 0.5 m2. The lowest richness values were found in dammed sites that tended toward lentic conditions. Ecnomidae (dammed zones), Limoniidae (downstream zones) and Heptageniidae (free flowing section) were identified as the best indicators of varying hydrological conditions. As suggested by the results of 4th Corner Method, environmental constraints define communities with different ecological traits. These results highlight hydromorphological control over macroinvertebrate community structure and reflect how regulated flows affect the Oglio River in terms of biodiversity, indicator taxa and ecological traits. The authors wish to stress the importance of considering the ecological effects of dams and impoundments on river systems in upstream areas as well as downstream. Copyright © 2012 John Wiley & Sons, Ltd.
Light and hydrologic variability as drivers of stream biofilm dynamics in a flume experiment
Authors: Ceola Serena , Bertuzzo Enrico , Mari Lorenzo , Botter Gianluca , Hödl Iris , Battin Tom J. , Gatto Marino , Rinaldo Andrea
Published: December 2012

We run a comparative study of the results of flume experiments and several dynamic models reproducing the effects of streamflow variability on biofilm (i.e. periphyton) temporal dynamics. During the experiment, two contrasting flow regimes, characterised by a constant and a time‐varying discharge temporal sequence, and four different light conditions (from 90% to 27% transmission of incident light) were performed to test the effects of availability and temporal variability of light and streamflows on biofilm growth. Several model formulations, describing growth and loss dynamics, have been explored in order to assess the relevant processes that controlled biofilm temporal pattern. Model identification criteria were used to identify the most suitable model, in which the growth rate is found to be dependent on density‐limitation dynamics coupled with a saturating light effect, while the loss rate is linearly proportional to the discharge conditions experienced in the flumes. This model formulation proved able to reproduce remarkably well the observed biofilm dynamics. In order to analyse the stationary behaviour of the best‐performing model reproducing biofilm biomass dynamics, we also run a long‐term simulation, where no significant biomass differences between the constant and stochastic flow regimes were detected. Copyright © 2012 John Wiley & Sons, Ltd.
Determination of Lead(II) in Groundwater Using Solid‐State Lead(II) Selective Electrodes by Tuned Galvanostatic Polarization
Authors: Lisak Grzegorz , Ciepiela Filip , Bobacka Johan , Sokalski Tomasz , Harju Leo , Lewenstam Andrzej
Published: December 2012

A method for direct potentiometric determination of lead(II) ion in native, untreated environmental samples of groundwater is reported. In a filtered sample, when applying a solid‐state (PbS/Ag2S) ion‐selective electrode in tuned galvanostatic polarization (TGP) mode, a concentration of 17.2±1.6 µg dm−3 was measured. The potentiometric results are compared with those obtained using inductively coupled plasma mass spectrometry (ICP‐MS), 18.0±0.4 µg dm−3 and differential pulse anodic stripping voltammetry (DPASV), 24.3±0.5 µg dm−3. Owing to limitations of other methods, the analysis of Pb2+ in the untreated and non‐filtered samples was only possible with the ion‐selective electrode solid‐state electrode. The described method can be an attractive alternative to existing methods of Pb2+ determination that are used to monitor groundwater pollution.
Evidence of impaired health in yellow perch (Perca flavescens) from a biological mercury hotspot in northeastern north America
Authors: Batchelar Katharina L. , Kidd Karen A. , Drevnick Paul E. , Munkittrick Kelly R. , Burgess Neil M. , Roberts Aaron P. , Smith James D.
Published: December 2012

Few studies have investigated the effects of mercury (Hg) on wild fish from remote areas, even though these fish can have high total Hg concentrations. In Kejimkujik National Park and National Historic Site (KNPNHS), Nova Scotia, Canada, concentrations of total Hg in many yellow perch (Perca flavescens) currently exceed the estimated threshold level for adverse effects in fish (0.2 µg Hg g−1 (wet wt), whole body). To determine whether Hg exposure is adversely affecting the general health of these fish, the authors collected male and female perch in the fall of 2009 and 2010 from 12 lakes within KNPNHS. The health endpoints condition, liver somatic index (LSI), and macrophage aggregates (MAs; indicators of oxidative stress and tissue damage) in the liver, kidney, and spleen were examined, and in female perch were compared between lakes and related to Hg concentrations measured in the muscle and liver tissue. No negative relationships between fish condition or LSI and Hg were found. However, within the liver, kidney, and spleen tissues of females, the relative area occupied by MAs was positively related to both muscle and liver Hg concentrations, indicating the health of these perch was adversely affected at the cellular level. These findings raise concerns for the health of these perch as well as for other wild fish populations known to have similarly elevated Hg concentrations. Environ. Toxicol. Chem. 2013;32:627–637. © 2012 SETAC
Brain region distribution and patterns of bioaccumulative perfluoroalkyl carboxylates and sulfonates in East Greenland polar bears (Ursus maritimus)
Authors: Greaves Alana K. , Letcher Robert J. , Sonne Christian , Dietz Rune
Published: December 2012

The present study investigated the comparative accumulation of perfluoroalkyl acids (PFAAs) in eight brain regions of polar bears (Ursus maritimus, n = 19) collected in 2006 from Scoresby Sound, East Greenland. The PFAAs studied were perfluoroalkyl carboxylates (PFCAs, C6–C15 chain lengths) and sulfonates (C4, C6, C8, and C10 chain lengths) as well as selected precursors including perfluorooctane sulfonamide. On a wet-weight basis, blood–brain barrier transport of PFAAs occurred for all brain regions, although inner regions of the brain closer to incoming blood flow (pons/medulla, thalamus, and hypothalamus) contained consistently higher PFAA concentrations compared to outer brain regions (cerebellum, striatum, and frontal, occipital, and temporal cortices). For pons/medulla, thalamus, and hypothalamus, the most concentrated PFAAs were perfluorooctane sulfonate (PFOS), ranging from 47 to 58 ng/g wet weight, and perfluorotridecanoic acid, ranging from 43 to 49 ng/g wet weight. However, PFOS and the longer-chain PFCAs (C10–C15) were significantly (p < 0.002) positively correlated with lipid content for all brain regions. Lipid-normalized PFOS and PFCA (C10–C15) concentrations were not significantly (p > 0.05) different among brain regions. The burden of the sum of PFCAs, perfluoroalkyl sulfonates, and perfluorooctane sulfonamide in the brain (average mass, 392 g) was estimated to be 46 µg. The present study demonstrates that both PFCAs and perfluoroalkyl sulfonates cross the blood–brain barrier in polar bears and that wet-weight concentrations are brain region–specific. Environ. Toxicol. Chem. 2013;32:713–722. © 2012 SETAC
Persistence of the tricyclic antidepressant drugs amitriptyline and nortriptyline in agriculture soils
Authors: Li Hongxia , Sumarah Mark W. , Topp Edward
Published: December 2012

Amitriptyline and nortriptyline are widely used tricyclic antidepressant drugs. They have been detected in wastewater, surface runoff, and effluents from sewage treatment plants. As such, they could potentially reach agriculture land through the application of municipal biosolids or reclaimed water. In the absence of data on their fate in the environment, the persistence and dissipation pathways of radiolabeled amitriptyline were determined in three agriculture soils varying widely in texture and chemical properties (loam soil, clay loam soil, and sandy loam soil). Tritiated amitriptyline was added to laboratory microcosms containing soils, and the metabolism of the extractable 3H was monitored during incubation at 30°C. The total solvent extractable radioactivity decreased in all three soils with times to dissipate 50% of material (DT50) ranging from 34.1 ± 3.2 (loam soil) to 85.3 ± 3.2 d (sandy soil). Nortriptyline (N-desmethyl amitriptyline) and amitriptyline-N-oxide were identified as major transformation products in all three soils by high performance liquid chromatography with photodiode array detector and time-of-flight mass spectrometry (HPLC-TOF-MS/UV). The addition of liquid municipal biosolids to the loam soil had no effect on the dissipation of amitriptyline. The persistence of nortriptyline was evaluated in the loam soil. The DT50 of nortriptyline was 40.5 ± 3.2 d estimated with HPLC-TOF-MS/UV. Approximately 10% of added nortriptyline was converted to hydroxylated products after 50 d of incubation. In summary, amitriptyline persisted in agricultural soils with major dissipation mechanisms, including forming nonextractable residues and producing various transformation products including the psychoactive drug nortriptyline. Environ. Toxicol. Chem. 2013;32:509–516. © 2012 SETAC
Effects of (−)‐borneol on the growth and morphology of Aspergillus fumigatus and Epidermophyton floccosom
Authors: Lee Su Yeon , Kim Seon Hong , Hong Chang Young , Park Mi‐Jin , Choi In‐Gyu
Published: December 2012

Antifungal activity of (−)‐borneol against two filamentous fungi, Aspergillus fumigatus and Epidermophyton floccosum, and relevant morphological effects were studied. Mycelial growths of the fungi were inhibited at 0.1, 0.5 and 1 mg/ml of (−)‐borneol in Sabouraud dextrose agar medium. The growth inhibition of the two filamentous fungi by (−)‐borneol was shown by ultra‐structural modifications visualized by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). FESEM images of treated mycelia showed interesting alterations of the hyphal surfaces, while TEM observations revealed more detailed changes in cell walls and cellular organelles when compared with the normal structures of the cells. The presence of ultra‐structural modifications of filamentous fungi due to treatment with (−)‐borneol strongly supported the hypothesis that (−)‐borneol induced morphological changes in mycelia. Copyright © 2012 John Wiley & Sons, Ltd.
Terrestrial arthropods from the Late Pleistocene of Jamaica: systematics, palaeoecology and taphonomy
Authors: Baalbergen Els , Donovan Stephen K.
Published: December 2012

The Red Hills Road Cave, Jamaica, is the most important site for terrestrial arthropods in the post‐Miocene of the Greater Antilles. Its fauna includes millipedes, isopods, crabs and insects, in addition to land snails and vertebrates. Arthropods are preserved in three dimensions and delicate structures such as limbs can be recognized. This unusual preservation was favoured by acidic groundwater rich in dissolved calcium carbonate; periods of high rainfall during which the bottle‐shaped cave was filled with water; and any arthropod washed in would have drowned. The absence of spiders, centipedes and most insects is due to the absence of carbonate in their exoskeletons. Millipedes and isopods possess a potential for preservation by carbonate mineralization that does not occur in other groups; they secrete calcium carbonate in the exoskeleton which hardens the cuticle and is water permeable, bringing about mineral replacement of the original structures.

Within the cave, fossil millipede taxa include Rhinocricus sp. or spp., Chondrotropis sp., Caraibodesmus verrucosus (Pocock) and Cyclodesmus sp. cf. C. porcellanus Pocock. The isopod fauna includes Pseudarmadillo sp., Venezillo boonae Van Name, and Philoscia spp. 1 and 2. Crab claws belong to Sesarma sp. cf. S. cookei Hartnoll. Millipedes and isopods are particularly complete, representing drowned individuals fossilized soon after death; land crabs occur as fingers and rare chelae, suggesting that they may be exuviae. Only the most robust parts of insects have been discovered, but are particularly rare, consisting of three taxa of fly puparia and one possible beetle elytra. Copyright © 2012 John Wiley & Sons, Ltd.
Microglial activation of the NLRP3 inflammasome by the priming signals derived from macrophages infected with mycobacteria
Authors: Lee Hye‐Mi , Kang Junghee , Lee Sung Joong , Jo Eun‐Kyeong
Published: December 2012

The inflammasome is a multimolecular complex that orchestrates the activation of proinflammatory caspases and interleukin (IL)‐1β, which is generally increased in the cerebrospinal fluids of patients with tuberculous meningitis. However, it has not been clarified whether mycobacteria can activate the inflammasome and induce IL‐1β maturation in microglia. In this study, we found that the priming of primary murine microglial cells with conditioned media from cultures of macrophages infected with Mycobacterium tuberculosis (Mtb) led to robust activation of caspase‐1 and IL‐1β secretion after Mtb stimulation. Potassium efflux and the lysosomal proteases cathepsin B and cathepsin L were required for the Mtb‐induced caspase‐1 activation and maturation of IL‐1β production in primed microglia. Mtb‐induced IL‐1β maturation was also found to depend on the nucleotide binding and oligomerization of domain‐like receptor family pyrin domain containing 3 protein (NLRP3) and apoptosis‐associated speck‐like protein containing a caspase recruitment domain (ASC), as well as the generation of mitochondrial reactive oxygen species (ROS). Notably, the priming of microglia with tumor necrosis factor‐α or oncostatin M resulted in caspase‐1 cleavage and IL‐1β secretion in response to Mtb. Moreover, dexamethasone, as an adjunctive therapy for patients of tuberculous meningitis, significantly reduced the Mtb‐induced maturation of IL‐1β through inhibition of mitochondrial ROS generation. Collectively, these data suggest that Mtb stimulation induces activation of the microglial NLRP3 inflammasome (composed of NLRP3, ASC, and cysteine protease caspase‐1) through microglia–leukocyte interactions as a priming signal, and that dexamethasone decreases inflammasome activation through inhibition of ROS of mitochondrial origin. © 2012 Wiley Periodicals, Inc.
Intrahippocampal infusion of the Ih blocker ZD7288 slows evoked theta rhythm and produces anxiolytic‐like effects in the elevated plus maze
Authors: Yeung Michelle , Dickson Clayton T , Treit Dallas
Published: December 2012

Hippocampal theta rhythm has been associated with a number of behavioral processes, including learning and memory, spatial behavior, sensorimotor integration and affective responses. Suppression of hippocampal theta frequency has been shown to be a reliable neurophysiological signature of anxiolytic drug action in tests using known anxiolytic drugs (i.e., correlational evidence), but only one study to date (Yeung et al. (2012) Neuropharmacology 62:155–160) has shown that a drug with no known effect on either hippocampal theta or anxiety can in fact separately suppress hippocampal theta and anxiety in behavioral tests (i.e., prima facie evidence). Here, we attempt a further critical test of the hippocampal theta model by performing intrahippocampal administrations of the Ih blocker ZD7288, which is known to disrupt theta frequency subthreshold oscillations and resonance at the membrane level but is not known to have anxiolytic action. Intrahippocampal microinfusions of ZD7288 at high (15 µg), but not low (1 µg) doses slowed brainstem‐evoked hippocampal theta responses in the urethane anesthetized rat, and more importantly, promoted anxiolytic action in freely behaving rats in the elevated plus maze. Taken together with our previous demonstration, these data provide converging, prima facie evidence of the validity of the theta suppression model. © 2012 Wiley Periodicals, Inc.
Evaluation of a changed model of care delivery in a Canadian province using outcome mapping
Authors: Tomblin Murphy Gail , MacKenzie Adrian , Alder Rob , Cruickshank Cindy
Published: December 2012

Background

Collaboration between the Nova Scotia Department of Health and Wellness, the province's District Health Authorities (DHAs) and the Izaak Walton Killam (IWK) Health Center led to the development and implementation of a new collaborative model of patient‐centered care delivery in the province.

Objective

The objective was to determine the effectiveness of the initiative in arriving at the envisioned care model by investigating its impacts (if any) on patient, system, and providers outcomes.

Methods

A repeated surveys study design with mixed methods in an outcome mapping framework was used to measure process and outcome indicators for patients and families, providers, and the system.

Results

Almost all outcomes at the patient and family, provider, and system level improved following the implementation of the model, and these effects were stronger on units where the model was more fully implemented.

Conclusions

The efforts of the province, DHAs and IWK to improve patient care through the new care model have been successful. This evaluation is unique in the broad range of indicators it incorporates. Comprehensive monitoring and evaluation of health system changes is critical to system effectiveness. Copyright © 2012 John Wiley & Sons, Ltd.
Mental health in France, policies and actors: developing administrative knowledge in a segmented world
Authors: Mossé Philippe , Maury Caroline , Daumerie Nicolas , Roelandt Jean‐Luc
Published: December 2012

The new mental health care policy, which has been set up in France, involves a change of paradigm, which has been going on since the 2000s: the emphasis is shifting from psychiatry to mental health care. This shift mainly concerns the knowledge about mental health is produced and circulates among an increasingly large number of bodies. Mainly grounded on actor interview analysis, official reports and blueprints, this study shows that the results of this process are numerous. They include the development of ambulatory care and strong moves towards decentralization. More data and knowledge are therefore to be shared in this more complex system. However, the French State, in the form of the central administration, is taking advantage of this move and is still contributing significantly to the definition and implementation of the new policy. On the other hand, the new governance dynamic is not leading to standardization of medical practices, as the mental health field remains highly heterogeneous. Copyright © 2012 John Wiley & Sons, Ltd.
Stress system changes associated with marijuana dependence may increase craving for alcohol and cocaine
Authors: Fox Helen C. , Tuit Keri L. , Sinha Rajita
Published: December 2012

Objective

To date, little research exists defining bio‐behavioral adaptations associated with both marijuana abuse and risk of craving and relapse to other drugs of abuse during early abstinence.

Method

Fifty‐nine treatment‐seeking individuals dependent on alcohol and cocaine were recruited. Thirty of these individuals were also marijuana (MJ) dependent; 29 were not. Twenty‐six socially drinking healthy controls were also recruited. All participants were exposed to three 5‐min guided imagery conditions (stress, alcohol/cocaine cue and relaxing), presented randomly, one per day across three consecutive days. Measures of craving, anxiety, heart rate, blood pressure, plasma adrenocorticotrophic hormone and cortisol were collected at baseline and subsequent recovery time points.

Results

The MJ‐dependent group showed increased basal anxiety ratings and cardiovascular output alongside enhanced alcohol craving and cocaine craving, and dampened cardiovascular response to stress and cue. They also demonstrated elevated cue‐induced anxiety and stress‐induced cortisol and adrenocorticotrophic hormone levels, which were not observed in the non‐MJ‐dependent group or controls. Cue‐related alcohol craving and anxiety were both predictive of a shorter number of days to marijuana relapse following discharge from inpatient treatment.

Conclusions

Findings provide some support for drug cross‐sensitization in terms of motivational processes associated with stress‐related and cue‐related craving and relapse. Copyright © 2012 John Wiley & Sons, Ltd.
Balancing trade‐off issues in land use change and the impact on streamflow and salinity management
Authors: Cheng Xiang , Benke Kurt K. , Beverly Craig , Christy Brendan , Weeks Anna , Barlow Kirsten , Reid Mark
Published: December 2012

The south‐west region of the Goulburn–Broken catchment in the south‐eastern Murray–Darling Basin in Australia faces a range of natural resource challenges. A balanced strategy is required to achieve the contrasting objectives of remediation of land salinization and reducing salt export, while maintaining water supply security to satisfy human consumption and support ecosystems. This study linked the Catchment Analysis Tool (CAT), comprising a suite of farming system models, to the catchment‐scale CATNode hydrological model to investigate the effects of land use change and climate variation on catchment streamflow and salt export. The modelling explored and contrasted the impacts of a series of different revegetation and climate scenarios. The results indicated that targeted revegetation to only satisfy biodiversity outcomes within a catchment is unlikely to have much greater impact on streamflow and salt load in comparison with simple random plantings. Additionally, the results also indicated that revegetation to achieve salt export reduction can effectively reduce salt export while having a disproportionately smaller affect on streamflows. Furthermore, streamflow declines can be minimized by targeting revegetation activities without significantly altering salt export. The study also found that climate change scenarios will have an equal if not more significant impact on these issues over the next 70 years. Uncertainty in CATNode streamflow predictions was investigated because of the effect of parameter uncertainty. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of a novel promyelocytic leukemia zinc‐finger isoform required for colorectal cancer cell growth and survival
Authors: Jones Christine , St‐Jean Stéphanie , Fréchette Isabelle , Bergeron Danny , Rivard Nathalie , Boudreau François
Published: December 2012

Promyelocytic leukemia zinc‐finger (PLZF) is a transcriptional repressor that regulates proliferation, differentiation and apoptosis among various cellular origins. PLZF expression is upregulated in colorectal cancer cell lines but its putative functional role in this context is unknown. Here, we report the identification of a novel p65 PLZF isoform that results from the usage of an evolutionarily conserved alternative translational initiation site. This isoform is devoid of the classical BTB/POZ domain required for nuclear localization and transcriptional repression. Depletion of p65 PLZF expression in colorectal cancer cell lines results in reduction of cell growth, loss of cell anchorage and increase in cell apoptosis. Overall, these results indicate that p65 PLZF is crucial to maintain colorectal cancer cell adhesion as well as survival and must occur independently of the traditionally viewed transcriptional role of PLZF in the course of these biological processes.
Immediate post‐implantation skin immobilization decreases skin regression around percutaneous osseointegrated prosthetic implant systems
Authors: Holt Brian Mueller , Bachus Kent N. , Beck James Peter , Bloebaum Roy Drake , Jeyapalina Sujee
Published: December 2012

A percutaneous, osseointegrated (OI) prosthetics are alternative docking systems for upper‐ and lower‐extremity prostheses. Persistent inflammation and micro‐motion are known to cause negative soft‐tissue adaptation in wound healing and may also be detrimental to implant longevity. In this study, a unique single‐stage sheep amputation and implantation model was developed to assess the efficacy of a porous coated sub‐dermal fixation surface in the prevention of skin regression around a percutaneous osseointegrated prosthetic implant. Porous coated and smooth sub‐dermal fixation surface prosthetics were implanted in the right forelimb of skeletally mature sheep for up to 12 months. Skin regression kinetics and sub‐dermal fixation surface coverage were measured from histological samples. Quantitative measurements of porous coated surfaces yielded skin migration rates of 0.90 ± 0.23, 0.56 ± 0.15, 0.44 ± 0.22 mm/month for the 6, 9, and 12 month animals, respectively. In addition, three load dependent regions of skin adaptation were identified; an interface, a transition, and a stress absorbance region. Immediate post‐implantation immobilization of the skin may foster improved load‐bearing percutaneous device outcomes. The skin adaptations reported here will aid in informing the design and optimization of future percutaneous, OI devices intended for the treatment of upper‐ and lower‐extremity amputees. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Influence of different amino acid groups on the free radical scavenging capability of multi walled carbon nanotubes
Authors: Amiri Ahmad , Memarpoor‐Yazdi Mina , Shanbedi Mehdi , Eshghi Hossein
Published: December 2012

Multi‐walled carbon nanotubes (MWCNTs) were functionalized with a series of amino acids (lysine, arginine, cysteine, histidine, and aspartic acid) by sonication. Surface functional groups of the treated MWCNTs were investigated by infrared spectroscopy, Raman spectroscopy and thermogravimetric analysis. The results indicated the formation of various amino acid functionalities on the MWCNT surface, as well as the improved dispersion of MWCNTs in water. After functionalization, the antioxidant activity of all treated samples was analyzed using 2,2‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid) (ABTS), 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), and hydroxyl radical scavenging, metal ion chelating, and reducing power assays. The antioxidant activity of the functionalized MWCNTs was 2–2.5 times greater than that of reduced glutathione (GSH) in ABTS radical scavenging, 1.5–5 times greater than that of GSH in reducing power, 1.3–1.8 times greater than that of butylated hydroxyanisole (BHA) in DPPH scavenging, and 3–10 times greater than that of GSH in hydroxyl radical scavenging. Accordingly, the amino acid‐functionalized MWCNTs were appeared to be more potent than BHA and GSH synthetic antioxidants, and can thus be considered as excellent antioxidants to scavenge free radicals. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Effect of chronic inflammation and immune response on regeneration induced by decellularized bovine pericardium
Authors: Umashankar P. R. , Arun T. , Kumary T. V.
Published: December 2012

Decellularised tissue produces a variety of host responses ranging from constructive remodeling to scarring on account of its differences in the source of tissue, processing or sterilization methods. In this study, in vivo regeneration induced by decellularised bovine pericardium with or without mild glutaraldehyde crosslinking was studied in relation to its immune and inflammatory response using rat abdominal regeneration model. Mild glutaraldehyde crosslinking was done to subdue inflammatory and immune response without compromising host cell incorporation and graft remodeling. Evaluations were done at both 21 and 90 days. Un‐crosslinked decellularised bovine pericardium showed more intense macrophage response predominantly of M2 phenotype at 90 days indicating chronic inflammatory response compared to mildly crosslinked group. This group also showed significant increase in plasma cell and lymphocyte count indicating immune stimulation. Lymphocyte transformation test detected presence of bovine pericardial antigen sensitized lymphocytes at both periods in un‐crosslinked group. Lymphocytes from mildly crosslinked group failed to respond in this test at both periods. Significantly higher antibody response was also noted at both periods in un‐crosslinked group. However, abdominal wall regeneration was observed only in animals implanted with un‐crosslinked decellularised bovine pericardium at 90 days. From the above findings, it is inferred that un‐crosslinked decellularised bovine pericardium produced significant chronic inflammatory response at 90 days and stimulated both humoral and cell mediated immune response in comparison to mildly crosslinked decellularised bovine pericardium. Yet this group produced skeletal muscle formation within graft at 90 days. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
A comparison of allogeneic and autologous mesenchymal stromal cells and osteoprogenitor cells in augmenting bone formation around massive bone tumor prostheses
Authors: Coathup Melanie J. , Kalia Priya , Konan Sujith , Mirza Kamran , Blunn Gordon W.
Published: December 2012

Spraying autologous mesenchymal stromal cells (MSCs) onto hydroxyapatite (HA)‐coated ingrowth collars, located at the shoulder of massive bone tumor implants, significantly increased extracortical bone‐bridging and osteointegration in an ovine model. In this study, we investigated the hypothesis that allogeneic MSCs and osteoprogenitor cells (OPCs) will augment bone growth equally when compared with autologous BMSCs. All collars were HA coated. In group i, the HA collar was coated with fibrin glue only. Cells were combined with fibrin glue and implants received (ii) 2 × 106 autologous MSCs, (iii) 10 × 106 autologous MSCs, (iv) 2 × 106 OPCs, (v) 10 × 106 OPCs, or (vi) 10 × 106 allogeneic MSCs. In group vii, collars were HA coated only. New bone area and bone‐implant contact onto the ingrowth collar was quantified radiographically and using histological techniques. Results showed that no extracortical bone formed adjacent to any collars sprayed with allogeneic MSCs and significantly more new bone was measured when all other experimental groups were compared (p < 0.05 in all cases). Most bone growth and bone‐implant contact occurred in the 10 × 106 OPC group. Spraying MSCs or OPCs onto the implant surface may be used in patients; however, further work is needed to determine the role of allogeneic cells in bone augmentation in vivo. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
On the performance of long‐range‐corrected density functional theory and reduced‐size polarized LPol‐n basis sets in computations of electric dipole (hyper)polarizabilities of π‐conjugated molecules
Authors: Baranowska‐Ła̧czkowska Angelika , Bartkowiak Wojciech , Góra Robert W. , Pawłowski Filip , Zaleśny Robert
Published: December 2012

Static longitudinal electric dipole (hyper)polarizabilities are calculated for six medium‐sized π‐conjugated organic molecules using recently developed LPol‐n basis set family to assess their performance. Dunning's correlation‐consistent basis sets of triple‐ζ quality combined with MP2 method and supported by CCSD(T)/aug‐cc‐pVDZ results are used to obtain the reference values of analyzed properties. The same reference is used to analyze (hyper)polarizabilities predicted by selected exchange‐correlation functionals, particularly those asymptotically corrected. © 2012 Wiley Periodicals, Inc.
Simulating GTP:Mg and GDP:Mg with a simple force field: A structural and thermodynamic analysis
Authors: Simonson Thomas , Satpati Priyadarshi
Published: December 2012

Di‐ and tri‐phosphate nucleotides are essential cofactors for many proteins, usually in an Mg2+‐bound form. Proteins like GTPases often detect the difference between NDP and NTP and respond by changing conformations. To study such complexes, simple, fixed charge force fields have been used, which allow long simulations and precise free energy calculations. The preference for NTP or NDP binding depends on many factors, including ligand structure and Mg2+ coordination and the changes they undergo upon binding. Here, we use a simple force field to examine two Mg2+ coordination modes for the unbound GDP and GTP: direct, or “Inner Sphere” (IS) coordination by one or more phosphate oxygens and indirect, “Outer Sphere” (OS) coordination involving one or more bridging waters. We compare GTP: and GDP:Mg binding with OS and IS coordination; combining the results with experimental data then indicates that GTP prefers the latter. We also examine different kinds of IS coordination and their sensitivity to a key force field parameter: the optimal Mg:oxygen van der Waals distance Rmin. Increasing Rmin improves the Mg:oxygen distances, the GTP: and GDP:Mg binding affinities, and the fraction of GTP:Mg with β + γ phosphate coordination, but does not improve or change the GTP/GDP affinity difference, which remains much larger than experiment. It has no effect on the free energy of GDP binding to a GTPase. © 2012 Wiley Periodicals, Inc.
A numerically stable restrained electrostatic potential charge fitting method
Authors: Zeng Juan , Duan LiLi , Zhang John Z.H. , Mei Ye
Published: December 2012

Inspired by the idea of charge decomposition in calculation of the dipole preserving and polarization consistent charges (Zhang et al., J. Comput. Chem. 2011, 32, 2127), we have proposed a numerically stable restrained electrostatic potential (ESP)‐based charge fitting method for protein. The atomic charge is composed of two parts. The dominant part is fixed to a predefined value (e.g., AMBER charge), and the residual part is to be determined by restrained fitting to residual ESP on grid points around the molecule. Nonuniform weighting factors as a function of the dominant charge are assigned to the atoms. Because the residual part is several folds to several orders smaller than the dominant part, the impact of ill‐conditioning is alleviated. This charge fitting method can be used in quantum mechanical/molecular mechanical (QM/MM) simulations and similar studies, where QM calculated electronic properties are frequently mapped to partial atomic charges. © 2012 Wiley Periodicals, Inc.
Identification of Human Corneal Epithelial Stem Cells on the Basis of High ABCG2 Expression Combined With a LargeN/C Ratio
Authors: Priya Chidambaranathan Gowri , Prasad Tilak , Prajna Namperumalsamy Venkatesh , Muthukkaruppan Veerappan
Published: December 2012

Purpose

Till date there is no exclusive marker for human corneal epithelial stem cells (CESCs). In this study, our strategy is to combine high expression of ABCG2, a putative SC marker with high N/C ratio to develop a specific method for identification of CESCs.

Methods

Limbal/corneal epithelial cells (LECs/CECs) were isolated from cadaver eyes by enzymatic treatment and the cytospin smears/cryosections were immunostained for ABCG2, p63, or connexin‐43 (Cx‐43) and counterstained with propidium iodide/DAPI. Analysis was carried out for (1) ABCG2 expression, N/C ratio, (2) p63, ABCG2, N/C ratio, and (3) ABCG2, Cx‐43, N/C ratio using confocal/fluorescence microscopy.

Results

ABCG2 was highly expressed by cells in the basal and suprabasal layers of limbus. The SCs identified on the basis of our earlier method using high levels of p63 expression along with high (>0.7) N/C ratio were strongly positive for ABCG2 and negative for differentiation marker Cx‐43. High expression of ABCG2 was also observed in cells with high p63 expression and low (<0.7) N/C ratio; however, they were positive for Cx‐43. Combining high ABCG2 expression with large N/C ratio in fluorescence microscopy identified 5.3 ± 3.5% LECs as putative SCs and this was confirmed by confocal microscopic analysis.

Conclusions

We demonstrate the importance of combining ABCG2 expression with N/C ratio for identification and quantification of human CESCs. This method will have application in evaluating the role of niche cells/factors in the maintenance of stemness. Microsc. Res. Tech. 76:242–248, 2013. © 2012 Wiley Periodicals, Inc.
Microscopic, molecular, and biochemical investigations to characterize a benthic cyanoprokaryote Leptolyngbya strainfrom Egypt
Authors: El Semary Nermin Adel
Published: December 2012

Microscopic, molecular, and biochemical investigations were conducted to describe a benthic mat‐forming Leptolyngbya isolate collected from wastewater canal in Helwan area, Egypt. Microscopic examination revealed that the isolate was filamentous, nonheterocystous, with obvious granular surface ornamentation. Electron microscopy was used to reveal the isolate's ultrastructure. Cross walls were thick with uneven deposition. Thylakoids were convoluted and irregularly distributed. Granular content differed from one cell to the other probably due to their physiological stages/position within the filaments and/or their age. Nycridial cells were present. Highly refractile gas vesicle‐like structures were detected and their identity as gas vesicles was confirmed by amplifying the gene coding for the gas vesicle protein GvpA. The presence of gas vesicles in benthic microorganisms is intriguing, and it is possible that those vesicles serve as a floating and dispersal mechanism as they increase in filaments that are about to break and release vacuolated hormogonia. To further confirm the isolate's identity, molecular analysis using 16S rRNA gene was performed. The sequence showed only 94% similarity to Leptolyngbya badia and less than 92% to other leptolyngbya. The phylogenetic analyses showed the coclustering of this strain with other Leptolyngbya strain. The fatty acid composition, used as a chemotaxonomic marker, revealed the presence of a considerable amount of polyunsaturated acids. Nevertheless, saturated fatty acids represented the highest proportion of the total fatty. Surprisingly, fatty acids of relatively limited occurrence within oscillatorian cyanobacteria such as saturated myristic fatty acid and polyunsaturated fatty acid C16:3 were found. Microsc. Res. Tech. 76:249–257, 2013. © 2013 Wiley Periodicals, Inc.
Novel Use of Scanning Electron Microscopy for Detection of Iron‐Induced Morphological Changes in Human Blood
Authors: Pretorius Etheresia , Vermeulen Natasha , Bester Janette , lipinski Boguslaw
Published: December 2012

Fibrinogen is key to the maintenance of hemostasis and is an acute phase protein that is part of the coagulation cascade of proteins. It plays a fundamental role in inflammation, particularly as indicator for a proinflammatory state and is a prominent marker for developing vascular inflammatory diseases. The ultrastructure of fibrin nets can be studied using scanning electron microscopy (SEM) with the addition of thrombin to plasma. In inflammatory conditions such as thromboembolic ischemic stroke and diabetes, the fibrin networks are changed to from dense matted fibrin deposits (DMDs) instead of typical netlike appearance. Similar DMDs can also be induced with the addition of FeCl2 and FeCl3. Importantly, the iron‐induced DMDs look similar to those from patients with prothrombotic conditions. Excessive or misplaced tissue iron now is recognized to pose a substantial health risk. The current research therefore investigates the establishment of a laboratory fibrinogen model to study that might mimic fibrin fiber generation that is achieved using plasma from healthy and diseased individuals. Furthermore, to determine whether the addition of iron to purified fibrinogen will show DMDs and whether hydrophilic agents can prevent them. We conclude that SEM is a very effective tool for the visualization of circulatory consequences of the interaction of iron‐induced hydroxyl radicals with human fibrinogen. Furthermore, this novel fibrinogen model provides a convenient method to study the interactions of the intramolecular and intermolecular hydrophobic forces responsible for the maintenance of the tertiary structure of native fibrin(ogen) and the prevention of iron‐induced DMDs formation by hydrophilic agents. Microsc. Res. Tech. 76:268–271, 2013. © 2012 Wiley Periodicals, Inc.
Iodine‐131 radiolabeling of poly ethylene glycol‐coated gold nanorods for in vivo imaging
Authors: Eskandari Najmeh , Yavari Kamal , Outokesh Mohammad , Sadjadi Sodeh , Ahmadi Seyed Javad
Published: December 2012

Gold nanorods (GNRs) can be used in various biomedical applications; however, very little is known about their in vivo tissue distribution by radiolabeling. Here, we have developed a rapid and simple method with high yield and without disturbing their optical properties for radiolabeling of gold rods with iodine‐131 in order to track in vivo tissue uptake of GNRs after systemic administration by biodistribution analysis and γ‐imaging. Following intravenous injection into rat, PEGylated GNRs have much longer blood circulation times.
Risk factors for and incidence of acute hepatitis C after the achievement of blood supply safety in Italy: Results from the national surveillance system
Authors: Spada Enea , Mele Alfonso , Mariano Andrea , Zuccaro Ornella , Tosti Maria Elena ,   on behalf of SEIEVA collaborating group
Published: December 2012

Surveillance systems for acute hepatitis C allow monitoring of disease incidence trends and transmission patterns. This study aimed to describe the epidemiological profile of reported cases of symptomatic acute hepatitis C in Italy after the achievement of blood supply safety. The incidence of symptomatic acute hepatitis C since 1991 was estimated. Risk factors for acute hepatitis C were analyzed for the period 2003–2010 through a case–control study within a population‐based surveillance for acute viral hepatitis. From 1991 to 2010, the incidence decreased from 2 to 0.2 per 100,000, with a more evident decrease among persons aged 15–24 years. During 2003–2010, 1,053 cases were reported. Intravenous drug use (adjusted odds ratio [adjOR], 30.5; 95% confidence interval [CI], 18.9–49.1), cohabitation or sexual partnership with an hepatitis C virus (HCV) carrier (adjOR, 11.2; 95% CI, 6.6–19.2), nosocomial exposure (adjOR, 6.6; 95% CI, 4.6–9.4); unsafe sexual practices (adjOR, 3.1; 95% CI, 1.9–5.2), and cosmetic treatments with percutaneous exposure (adjOR, 1.7; 95% CI, 1.2–2.4) were independently associated with acute hepatitis C. Population attributable risk estimates indicated nosocomial exposure (39.6%) and intravenous drug use (30.5%) as responsible for most cases. In conclusion, the incidence of symptomatic acute hepatitis C is declining in Italy. Currently, the most important risk factors are: having an HCV‐positive household or sexual partner, unsafe sexual practices, cosmetic percutaneous treatments, intravenous drug use, and nosocomial exposure; the latter two factors are responsible for most cases. Effective prevention programs for intravenous drug users and strict adherence to universal precautions in healthcare settings are needed. J. Med. Virol. 85:433–440, 2013. © 2012 Wiley Periodicals, Inc.
Rainfall variations in south‐eastern Australia part 1: consolidating evidence from pre‐instrumental documentary sources, 1788–1860
Authors: Fenby Claire , Gergis Joëlle
Published: December 2012

This study fills an important gap in south‐eastern Australia's climate record by compiling qualitative historical data from the time of first European settlement of Australia in 1788 until widespread meteorological observations become available in 1860. In this study, we consolidate twelve documentary‐based rainfall chronologies for five sub‐regions of south‐eastern Australia (SEA) over the 1788–1860 period using a range of secondary historical sources. Our analysis identified 27 drought years in SEA between 1788 and 1860, and 14 years of high rainfall in New South Wales (NSW) between 1788 and 1840. Given that our current understanding of Australian drought is still largely confined to the post‐1900 period covered by instrumental records, we provide an outline of the drought and wet periods to provide a consolidated reference of historical accounts of lesser known pre‐instrumental rainfall variations for researchers working in the field. This index is also intended to serve as an independent inter‐annual verification source for palaeoclimate reconstructions being developed in the Australian region. This study confirms that SEA has experienced considerable rainfall variability that has influenced past Australian societies since the first European settlement in 1788. Of the droughts identified in this study, 1837–1841 was the longest and most widespread event influencing all subregions. The 1793–1809 period was particularly wet, with periods of heavy rainfall often resulting in devastating floods on the Hawkesbury River region of Sydney. Despite the geographical biases present in the documentary material, it is clear that historical records provide important information on rainfall variations in SEA and their societal impacts over the 1788–1860 pre‐instrumental period. The results presented here provide an important basis for developing an extended rainfall index for eastern NSW from 1788–2008, and is the subject of part 2 of this study (Gergis J, Ashcroft L. 2012. Rainfall variations in south‐eastern Australia part 2: a comparison of documentary, early instrumental and palaeoclimate records, 1788–2008. International Journal of Climatology).
Resonance Raman spectroscopic and density functional theory investigation of the excited state structural dynamics of 2‐mercapto‐1‐methylimidazole
Authors: Jian Ji‐Wen , Zhang Hai‐Bo , Chen Cong‐Qi , Zhao Yanying , Zheng Xuming
Published: December 2012

The resonance Raman spectroscopy in conjunction with the density functional theory calculations were used to study the excited state structural dynamics of 2‐mercapto‐1‐methylimidazole (MMI). The experimental UV absorption bands were assigned according to the time‐dependent density functional calculations. The vibrational assignments were done for the A‐band resonance Raman spectra of MMI in water and acetonitrile on the basis of the Fourier transform infrared (FT‐IR) and FT‐Raman measurements in solid, in water and in acetonitrile and the corresponding B3LYP/6‐311+G(d, p) computations. The dynamic structures of MMI were obtained by analysis of the resonance Raman intensity pattern and normal mode analysis. The differences in the dynamic structures of MMI and thiourea were revealed and explained. The structural dynamic of MMI was found to be similar to that of 2‐thiopyrimidone in terms of major reaction coordinates and thus favored the intra‐molecular proton transfer reaction. Copyright © 2012 John Wiley & Sons, Ltd.
Recent Trends in the Chemistry of Shape‐Memory Polymers
Authors: Julich‐Gruner Konstanze K. , Löwenberg Candy , Neffe Axel T. , Behl Marc , Lendlein Andreas
Published: December 2012

Shape‐memory polymers (SMPs) are stimuli‐sensitive materials capable of performing complex movements on demand, which makes them interesting candidates for various applications, for example, in biomedicine or aerospace. This trend article highlights current approaches in the chemistry of SMPs, such as tailored segment chemistry to integrate additional functions and novel synthetic routes toward permanent and temporary netpoints. Multiphase polymer networks and multimaterial systems illustrate that SMPs can be constructed as a modular system of different building blocks and netpoints. Future developments are aiming at multifunctional and multistimuli‐sensitive SMPs.