bluuebunny/crossref_metadata_2025 huggingface dataset:
Astrocyte reactivity to unconjugated bilirubin requires TNF‐α and IL‐1β receptor signaling pathways
Authors: Fernandes Adelaide , Barateiro Andreia , Falcão Ana Sofia , Silva Sandra Leit‐Ao , Vaz Ana Rita , Brito Maria Alexandra , Marques Silva Rui Fernando , Brites Dora
Published: October 2010

Jaundice and sepsis are common neonatal conditions that can lead to neurodevelopment sequelae, namely if present at the same time. We have reported that tumor necrosis factor (TNF)‐α and interleukin (IL)‐1β are produced by cultured neurons and mainly by glial cells exposed to unconjugated bilirubin (UCB). The effects of these cytokines are mediated by cell surface receptors through a nuclear factor (NF)‐κB‐dependent pathway that we have showed to be activated by UCB. The present study was designed to evaluate the role of TNF‐α and IL‐1β signaling on astrocyte reactivity to UCB in rat cortical astrocytes. Exposure of astrocytes to UCB increased the expression of both TNF‐α receptor (TNFR)1 and IL‐1β receptor (IL‐1R)1, but not TNFR2, as well as their activation, observed by augmented binding of receptors' molecular adaptors, TRAF2 and TRAF6, respectively. Silencing of TNFR1, using siRNA technology, or blockade of IL‐1β cascade, using its endogenous antagonist, IL‐1 receptor antagonist (IL‐1ra), prevented UCB‐induced cytokine release and NF‐κB activation. Interestingly, lack of TNF‐α signal transduction reduced UCB‐induced cell death for short periods of incubation, although an increase was observed after extended exposure; in contrast, inhibition of IL‐1β cascade produced a sustained blockade of astrocyte injury by UCB. Together, our data show that inflammatory pathways are activated duringin vitroexposure of rat cortical astrocytes to UCB and that this activation is prolonged in time. This supports the concept that inflammatory pathways play a role in brain damage by UCB, and that they may represent important pharmacological targets. © 2010 Wiley‐Liss, Inc.
Evidence of hypothalamic degeneration in the anorectic anx/anx mouse
Authors: Nilsson Ida A. K. , Thams Sebastian , Lindfors Charlotte , Bergstrand Anita , Cullheim Staffan , Hökfelt Tomas , Johansen Jeanette E.
Published: October 2010

Mice homozygous for the anorexia (anx) mutation are characterized by poor food intake and death by three to five weeks after birth. By P21 these mice display lower density of hypothalamic neuropeptides, including Agouti gene‐related protein (AGRP). The AGRP/neuropeptide Y (NPY) system of the anx/anx mice develops normally until postnatal day (P) 12, then the normal increase in fiber density ceases, in some areas even distinctly decreases. This overlaps with activation of microglia, indicating an inflammatory and/or degenerative process. Here we studied, by in situ hybridization and immunohistochemistry (IHC), the expression of major histocompatibility complex (MHC) class I‐related molecules and markers for cellular reactivity in hypothalamus of anx/anx mice. MHC class I transcript and ‐related proteins were found in arcuate nucleus (Arc), presumably both in neurons and glia, the latter also in areas innervated by AGRP (NPY) neurons. In the anx/anx hypothalamus, using TUNEL labeling, significantly higher number of apoptotic cells were found compared with +/+ mice, and active caspase 6 immunoreactivity was detected in degenerating NPY‐fibers as well as signs of “microglia‐associated cell death”. In addition, Y1 receptor‐labeled processes and soma of pro‐opiomelanocortin (POMC) neurons, were markedly decreased at P21. These results support the hypothesis of degeneration of hypothalamic arcuate neuron populations in the anx/anx mice, whereby the AGRP system may be first affected, the changes in the POMC system being secondary in this process. © 2010 Wiley‐Liss, Inc.
Ectopic release sites lack fast vesicle recycling mechanisms, causing long‐term depression of neuron‐glial transmission in rat cerebellum
Authors: Balakrishnan Saju , Jackson Claire , Russell Noah , Bellamy Tomas C
Published: October 2010

Classical synaptic transmission occurs at active zones within the synaptic cleft, but increasing evidence suggests that vesicle fusion can also occur outside of these zones, releasing transmitter directly into the extrasynaptic space. The role of such “ectopic” release is unclear, but in the cerebellar molecular layer it is thought to guide the processes of Bergmann glia toward synaptic terminals through activation of glial α‐amino‐3‐hydroxyl‐5‐methyl‐4‐isoxazolepropionate (AMPA) receptors. Once surrounding the terminal, the glial process is presumed to limit spillover of neurotransmitter between synapses by rapid uptake of glutamate. We have previously reported that this route for neuron‐glial transmission exhibits long‐term depression following repetitive stimulation at frequencies in the 0.1–1 Hz range, in ex vivo slices from rat cerebellum. Here, we present evidence that LTD arises because ectopic sites lack the fast recycling mechanisms that operate at the active zone. Consequently, ectopic vesicles constitute an exhaustible pool that is depleted at normal synaptic firing rates and only recovers slowly. This effect is cumulative, meaning that the strength of ectopic transmission provides a read‐out of the average frequency of presynaptic firing over several minutes. Glial processes are therefore likely to interact most closely with terminals that fire infrequently; conditions that may promote elimination of, rather than support for, the connection. © 2010 Wiley‐Liss, Inc.
Response of transcription factor NFATc3 to excitotoxic and traumatic brain insults: Identification of a subpopulation of reactive astrocytes
Authors: Serrano‐Pérez María C. , Martín Eduardo D. , Vaquero Cecilia F. , Azcoitia Iñigo , Calvo Soledad , Cano Eva , Tranque Pedro
Published: October 2010

Astrocytes react to brain injury triggering neuroinflammatory processes that determine the degree of neuronal damage. However, the signaling events associated to astrocyte activation remain largely undefined. The nuclear factor of activated T‐cells (NFAT) is a transcription factor family implicated in activation of immune cells. We previously characterized the expression of NFAT isoforms in cultured astrocytes, and NFAT activation in response to mechanical lesion. Here we analyze NFATc3 in two mouse models of inflammatory brain damage: hippocampal excitotoxicity induced by intracerebral kainic acid (KA) injection and cortical mechanical lesion. Immunofluorescence results demonstrated that NFATc3 is specifically induced in a subset of reactive astrocytes, and not in microglia or neurons. In KA‐treated brains, NFATc3 expression is transient and NFATc3‐positive astrocytes concentrate around damaged neurons in areas CA3 and CA1. Complementary Western blot and RT‐PCR analysis revealed an NFAT‐dependent induction of RCAN1‐4 and COX‐2 in hippocampus as soon as 6 h after KA exposure, indicating that NFAT activation precedes NFATc3 over‐expression. Moreover, activation of NFAT by ATP increased NFATc3 mRNA levels in astrocyte cultures, suggesting that NFATc3 expression is controlled through an auto‐regulatory loop. Meanwhile, stab wound enhanced NFATc3 expression specifically in a subclass of reactive astrocytes confined within the proximal layer of the glial scar, and GFAP immunoreactivity was attenuated in NFATc3‐expressing astrocytes. In conclusion, our work establishes NFATc3 as a marker of activation for a specific population of astrocytes in response to brain damage, which may have consequences for neuronal survival. © 2010 Wiley‐Liss, Inc.
An unusual reaction of 2‐ethoxyethenylphosphonic dichloride with resorcinol and its derivatives: Synthesis of bicyclic phosphonates with endocyclic P–C bond
Authors: Sadykova Yulia M. , Knyazeva Irina R. , Burilov Alexander R. , Pudovik Michael A. , Dobrynin Alexey B. , Litvinov Igor A. , Sinyashin Oleg G.
Published: October 2010

The condensation of 2‐ethoxyethenyl‐ phosphonic dichloride with
resorcinol and its derivatives in dichloromethane in the presence of trifluoroacetic acid results in the formation of new bicyclic phosphonates with an endocyclic PC bond. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 22:1–4, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20646
Prospective validation of the prognostic value of elevated serum vascular endothelial growth factor in patients with nasopharyngeal carcinoma: More distant metastases and shorter overall survival after treatment
Authors: Lv Xing , Xiang Yan‐Qun , Cao Su‐Mei , Qian Chao‐Nan , Li Ning‐Wei , Guo Ling , Mai Hai‐Qiang , Chen Qiu‐Yan , Huang Pei‐Yu , Luo DongHua , Cao Ka‐Jia , Hong Ming‐Huang , Guo Xiang
Published: October 2010

Background

The purpose of this prospective study was to investigate the prognostic value of serum vascular endothelial growth factor (sVEGF) in patients with nasopharyngeal carcinoma (NPC).

Methods

sVEGF was prospectively detected in 306 patients with NPC with enzyme‐linked immunosorbent assay before treatment. The correlations between sVEGF and the survival of these patients were evaluated.

Results

Patients were followed for at least 36 months. The mean sVEGF was 387.0 ng/L. sVEGF showed no difference in sex, age, and local recurrence. However, sVEGF was positively associated with histology, TNM classification, distant metastasis, and overall survival (OS; p < .05). The 4‐year OS and distant metastasis–free survival (DMFS) of the high‐sVEGF versus low‐sVEGF groups were 68% versus 86% and 70% versus 89%, respectively (p < .05). Stratified analysis showed that patients with stage IVa,b, T4, N1, or Npositive disease with high VEGF levels had worse 4‐year OS and 4‐year DMFS than those with low VEGF levels (p < .05). Multifactorial Cox regression confirmed sVEGF was among the independent prognostic factors.

Conclusion

Elevation of sVEGF in patients with NPC predicts more posttreatment distant metastases and shorter OS and can be used as an independent poor prognostic indicator. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Vascular endothelial growth factor and vascular endothelial growth factor receptor‐2 tumor expression in patients with advanced laryngeal cancer after induction chemotherapy for organ preservation
Authors: Rueda Antonio , Cazorla Oscar , Pérez Lidia , Álvarez Martina , Redondo Maximino , Gallego Elena , Sáez Maribel , Medina José Antonio , Solano José , Matilla Alfredo
Published: October 2010

Background

Vascular endothelial growth factor (VEGF) expression seems to be associated with worse overall survival in patients with head and neck squamous cell carcinoma. The purposes of this study were to assess the prognostic values of the immunohistochemical expression of VEGF and vascular endothelial growth factor receptor‐2 (VEGFR‐2) in a cohort of patients with operable advanced laryngeal cancer who had been treated with induction chemotherapy.

Methods

VEGF and VEGFR‐2 expression in the malignant cells was quantified by an enzyme immunosorbent assay in a retrospective series.

Results

Fifty‐nine patients were included in this study. We found moderate to high VEGF expression in 61% of patients and none to low expression in 39%. VEGFR‐2 expression was moderate to high in 58% of patients and was none to low in 42%. The probability of a complete response to induction chemotherapy was significantly higher in patients with none to low VEGF expression (74% vs 40%; p = .02).

Conclusion

VEGF expression seems to be a significant predictor of complete response to induction chemotherapy. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Long–term follow‐up of 44 patients with adenocarcinoma of the nasal cavity and sinuses primarily treated with endoscopic resection followed by radiotherapy
Authors: Van Gerven Laura , Jorissen Mark , Nuyts Sandra , Hermans Robert , Vander Poorten Vincent
Published: October 2010

Background

Endoscopic resection followed by radiotherapy as primary treatment for adenocarcinoma of the sinuses is emerging as an alternative to open resection.

Methods

A total of 44 patients primarily treated by an endoscopic approach followed by radiotherapy from 1992 to 2004 seen at our ENT‐Department were analyzed for outcome and prognostic factors.

Results

Median follow‐up was 61 months. Median follow‐up of the patients alive at the end of the follow‐up period was 100 months. For the 5‐year follow‐up, the overall survival, disease‐specific survival, and recurrence‐free survival were 63% (±7% SE), 82% (±6), and 60% (±8%), respectively. The overall survival, disease‐specific survival, and recurrence‐free survival after 100 months of follow‐up were 53% (±8%), 72% (±9%), and 54% (±9%), respectively. Four factors significantly influenced the disease‐specific survival.

Conclusion

This study of a homogeneous cohort of patients with sinonasal adenocarcinoma treated by endoscopic resection and radiotherapy confirms that endoscopic resection is a valid alternative to open resection. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Survival of patients with palliative head and neck cancer
Authors: Ledeboer Quirine C. P. , van der Schroeff Marc P. , Pruyn Jean F. A. , de Boer Maarten F. , Baatenburg de Jong Robert J. , van der Velden Lilly‐Ann
Published: October 2010

Background

The purpose of this study was to describe patient characteristics and prognostic factors for survival in the palliative stage of patients with head and neck cancer.

Methods

Since November 2003, all patients with palliative head and neck cancer treated in our hospital have been recorded in a central database. In total, 262 deceased patients were included in this retrospective study.

Results

The reasons for palliation were inoperability, distant metastases, refusal of curative treatment, or poor condition. The mean palliative phase lasted 5.3 months for patients with squamous cell carcinomas. Involvement of a specialized nurse was significantly related with the number of admissions and place of dying. Multivariate analysis showed comorbidity and treatment to be independent predictors of survival in the palliative phase.

Conclusion

Comorbidity and palliative interventions are possible prognostic factors for survival. The involvement of a specialized nurse might be associated with an improved quality of life. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Antitumor activity of enzastaurin as radiation sensitizer in head and neck squamous cell carcinoma
Authors: Yin Xiaoying , Hayes D. Neil , Shores Carol G
Published: October 2010

Background

The antitumor effect of enzastaurin, a specific protein kinase C beta (PKC‐β) inhibitor, was tested on head and neck squamous cell carcinoma (HNSCC) cell lines, as well as HNSCC xenograft model.

Methods

HNSCC cell lines and xenograft were treated with enzastaurin alone or in combination with radiation to evaluate its antitumor effect. Annexin V‐FITC staining and Western blot were done to analyze enzastaurin‐induced changes in apoptosis and the PIK3/AKTAKT signal transduction pathway.

Results

Enzastaurin showed strong antitumor activity either alone or in combination with radiation both in HNSCC cell lines and in xenograft, with a corresponding reduction in the expression of key radioresponsive proteins.

Conclusion

Enzastaurin can inhibit tumor growth and improve the efficacy of radiation for HNSCC both in vitro and in vivo. This suggests that enzastaurin may represent a better strategy for the treatment of HNSCC patients, either as a monotherapy or as a radiosensitizer. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Lean body mass gain in patients with head and neck squamous cell cancer treated perioperatively with a protein‐ and energy‐dense nutritional supplement containing eicosapentaenoic acid
Authors: Weed Harrison G. , Ferguson Maree L. , Gaff Robin L , Hustead Deborah S. , Nelson Jeffrey L. , Voss Anne C.
Published: October 2010

Background

Cancer‐associated weight loss may be mediated by an inflammatory response to cancer. Eicosapentaenoic acid (EPA) may suppress this response.

Methods

Beginning no later than 2 weeks before surgery, patients with head and neck cancer and with weight loss, who were undergoing major resection with curative intent consumed a protein‐ and energy‐dense nutritional supplement containing EPA from fish oil, in addition to usual diet or tube feed.

Results

Thirty‐one subjects consumed an average of 1.8 containers/day before surgery and 1.5/day during hospitalization (per container: 300 kilocalories, 16 grams (g) protein, 1.08 g EPA). Seventy percent of subjects maintained or gained weight before hospital admission. Mean weight gain was 0.71 kg at admission and 0.66 kg at discharge. At discharge lean body mass increased by 3.20 kg (p < .001) and fat decreased by 3.19 kg (p < .001).

Conclusions

An EPA‐containing protein‐ and energy‐dense nutritional supplement may help increase perioperative lean body mass in patients with head and neck cancer–related weight loss. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Expression of inhibitor of apoptosis family proteins in human oral squamous cell carcinogenesis
Authors: Chen Yuk‐Kwan , Huse Shui‐Sang , Lin Li‐Min
Published: October 2010

Background

The purpose of this study was to determine inhibitor of apoptosis (IAP) expression, its relationship with p53, and epigenetic change in oral carcinogenesis that remain to be elucidated.

Methods

We measured IAP and p53 expression in 44 oral potentially malignant disorders and their corresponding malignant‐transformed oral squamous cell carcinomas (OSCCs), and in 44 other non‐transformed oral potentially malignant disorders. IAP and p53 expression in 10 fresh OSCCs, together with epigenetic change of their mutation, were also determined.

Results

Normal mucosa did not express IAP/mutated p53. Oral potentially malignant disorders that underwent transformation exhibited high IAPs (>90%) and less‐consistent mutated‐p53 (34%) expression, whereas transformed OSCCs exhibited high IAP and mutated‐p53 expression. Fresh OSCCs exhibited 80% to 100% IAP mRNA expression and 50% protein, mRNA, and p53 mutation expression. Normal tissues revealed DNA methylation of IAP, whereas cancerous tissues overexpressing IAP exhibited hypomethylation.

Conclusion

This study showed that IAP expression is an early event in oral carcinogenesis and that epigenetic and genetic pathways are associated with IAP expression in OSCC. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Limitations and complications of endoscopic surgery for treatment for sinonasal inverted papilloma: A reassessment after 212 cases
Authors: Lombardi Davide , Tomenzoli Davide , Buttà Laura , Bizzoni Andrea , Farina Davide , Sberze Federica , Karligkiotis Apostolos , Castelnuovo Paolo , Nicolai Piero
Published: October 2010

Background

The purpose of this study was to define the optimal surgical strategy for sinonasal inverted papilloma in relation to the site of origin and tumor extent.

Methods

Retrospective analysis of patients affected by inverted papilloma treated by purely endoscopic or combined approaches at the Department of Otorhinolaryngology of the University of Brescia and Pavia–Varese from November 1991 to December 2007.

Results

Two hundred twelve patients were considered eligible for this study. An exclusive endoscopic approach was performed in 198 patients (93.4%); the remaining 14 patients (6.6%) underwent an endoscopic approach combined with an osteoplastic frontal flap. Follow‐up ranged from 24 to 192 months (mean, 53.8 months). A single recurrence was observed in 12 patients (5.7%). Twenty complications (9.4%) were observed.

Conclusion

Endoscopic surgery is the first choice in the treatment of inverted papilloma; only lesions with extensive involvement of frontal sinus and/or supraorbital cell may require a combined approach. A minimum follow‐up of 5 years is recommended. © 2010 Wiley Periodicals, Inc. Head Neck, 2011
Lymph node ratio as an independent prognostic factor in oral squamous cell carcinoma
Authors: Ebrahimi Ardalan , Clark Jonathan R. , Zhang Wan Jing , Elliott Michel S. , Gao Kan , Milross Christopher G. , Shannon Kerwin F.
Published: October 2010

Background

We aimed to validate the lymph node ratio (LNR) as an independent prognostic factor in oral squamous cell carcinoma (OSCC) and compare its utility with the current nodal staging system.

Methods

We conducted a retrospective analysis of 313 patients with OSCC undergoing neck dissection. The LNR was adjusted by relevant covariates in a multivariable Cox regression model.

Results

LNR displaced conventional nodal staging and was shown to be an independent predictor of regional failure (p = .020), disease‐specific (p = .003) and overall survival (p = .001). Patients with an LNR of 2.5% to 7.5%, 7.5% to 20%, and >20% had 2.6, 3.7, and 4.4 times the risk of death from OSCC, respectively, when compared with patients with an LNR <2.5%.

Conclusions

The LNR is an independent prognostic factor in OSCC and may be used in conjunction with the current TNM staging to enable better risk stratification and selection for adjuvant therapy. © 2010 Wiley Periodicals, Inc. Head Neck, 2010
Prediction of depth‐integrated fluxes of suspended sediment in the Amazon River: particle aggregation as a complicating factor
Authors: Bouchez J. , Métivier F. , Lupker M. , Maurice L. , Perez M. , Gaillardet J. , France‐Lanord C.
Published: October 2010

Large rivers have been previously shown to be vertically heterogeneous in terms of suspended particulate matter (SPM) concentration, as a result of sorting of suspended solids. Therefore, the spatial distribution of suspended sediments within the river section has to be known to assess the riverine sedimentary flux. Numerous studies have focused on the vertical distribution of SPM in a river channel from a theoretical or experimental perspective, but only a few were conducted so far on very large rivers. Moreover, a technique for the prediction of depth‐integrated suspended sediment fluxes in very large rivers based on sediment transport dynamics has not yet been proposed. We sampled river water along depth following several vertical profiles, at four locations on the Amazon River and its main tributaries and at two distinct water stages. Depending on the vertical profile, a one‐ to fivefold increase in SPM concentration is observed from river channel surface to bottom, which has a significant impact on the ‘depth‐averaged’ SPM concentration. For each cross section, a so‐called Rouse profile quantitatively accounts for the trend of SPM concentration increase with depth, and a representative Rouse number can be measured for each cross section. However, the prediction of this Rouse number would require the knowledge of the settling velocity of particles, which is dependent on the state of aggregation affecting particles within the river. We demonstrate that in the Amazon River, particle aggregation significantly influences the Rouse number and renders its determination impossible from grain‐size distribution data obtained in the lab. However, in each cross section, the Rouse profile obtained from the fit of the data can serve as a basis to model, at first order, the SPM concentration at any position in the river cross section. This approach, combined with acoustic Doppler current profiler (ADCP) water velocity transects, allows us to accurately estimate the depth‐integrated instantaneous sediment flux. Copyright © 2010 John Wiley & Sons, Ltd.
Landscape structure, groundwater dynamics, and soil water content influence soil respiration across riparian–hillslope transitions in the Tenderfoot Creek Experimental Forest, Montana
Authors: Pacific Vincent J. , McGlynn Brian L. , Riveros‐Iregui Diego A. , Welsch Daniel L. , Epstein Howard E.
Published: October 2010

Variability in soil respiration at various spatial and temporal scales has been the focus of much research over the last decade aimed to improve our understanding and parameterization of physical and environmental controls on this flux. However, few studies have assessed the control of landscape position and groundwater table dynamics on the spatiotemporal variability of soil respiration. We investigated growing season soil respiration in a ∼393 ha subalpine watershed in Montana across eight riparian–hillslope transitions that differed in slope, upslope accumulated area (UAA), aspect, and groundwater table dynamics. We collected daily‐to‐weekly measurements of soil water content (SWC), soil temperature, soil CO2 concentrations, surface CO2 efflux, and groundwater table depth, as well as soil C and N concentrations at 32 locations from June to August 2005. Instantaneous soil surface CO2 efflux was not significantly different within or among riparian and hillslope zones at monthly timescales. However, cumulative integration of CO2 efflux during the 83‐day growing season showed that efflux in the wetter riparian zones was ∼25% greater than in the adjacent drier hillslopes. Furthermore, greater cumulative growing season efflux occurred in areas with high UAA and gentle slopes, where groundwater tables were higher and more persistent. Our findings reveal the influence of landscape position and groundwater table dynamics on riparian versus hillslope soil CO2 efflux and the importance of time integration for assessment of soil CO2 dynamics, which is critical for landscape‐scale simulation and modelling of soil CO2 efflux in complex landscapes. Copyright © 2010 John Wiley & Sons, Ltd.
Using 137Cs measurements to establish catchment sediment budgets and explore scale effects
Authors: Porto Paolo , Walling Desmond E. , Callegari Giovanni
Published: October 2010

Growing awareness of the wider environmental significance of fine sediment transport by rivers and associated sediment problems linked to sediment–water quality interactions, nutrient and contaminant transfer, and the degradation of aquatic habitats has resulted in the need for an improved understanding of the mobilization and transfer of sediment in catchments to support the development of effective sediment management strategies. The sediment budget provides a key integrating concept for assembling information on the internal functioning of a catchment in terms of its sediment dynamics by providing information on the mobilization, transfer, storage and output of sediment. One key feature of a catchment sediment budget is the relationship between the sediment yield at the catchment outlet and rates of sediment mobilization and transfer within the catchment, which is commonly represented by the sediment delivery ratio. To date, most attempts to derive estimates of this ratio have been based on a comparison of the measured sediment yield from a catchment with an estimate of the erosion occurring within the catchment, derived from an erosion prediction procedure, such as the Universal Soil Loss Equation (USLE) or its revised version, RUSLE. There is a need to obtain more direct and spatially distributed evidence of the erosion rates occurring within a catchment and to characterize the links between sediment mobilization, transfer, storage and output more explicitly. In this context, fallout radionuclides have proved particularly useful as sediment tracers. This paper reports the results of a study aimed at exploring the use of caesium‐137 (137Cs) measurements to establish sediment budgets for three catchments of different sizes and contrasting land use located in Calabria, southern Italy. Long‐term measurements of sediment output were available for the catchments, and, by using the estimates of gross and net rates of soil loss within the catchments provided by 137Cs measurements, it was possible to establish the key components of the sediment budget for each catchment. By documenting the sediment budgets of three catchments of different sizes, the study provides a basis for exploring the effects of scale on catchment sediment budgets and, in particular, the increasing importance of catchment storage as the size of the catchment increases. The results of this study demonstrate a reduction in the sediment delivery ratio from 98 to 2% as catchment area increases from 1·47 ha to 31·2 km2. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of area under‐estimations of sloped mountain terrain on simulated hydrological behaviour: a case study using the ACRU model
Authors: Kienzle Stefan W.
Published: October 2010

Sloped areas calculated from a GIS raster file, such as a digital elevation model, are smaller than the true surface area, because they are projected to a planimetric plane. In mountainous regions this sloped area under‐estimation (SAUE) can have significant consequences on hydrological calculations. A sensitivity analysis is conducted, using the ACRU agro‐hydrological modelling system in a small watershed in Glacier National Park, Montana, USA, to investigate the sensitivity of the SAUE on key elements of the hydrological cycle, including precipitation depth, April snow depth, August soil moisture deficit, actual evapotranspiration depth, and runoff depth. The sensitivity analysis is based on 224 unique combinations of slope, soil and land cover types, elevation with associated precipitation depths, and north and south facing radiation regimes. Results revealed an increasing influence of the SAUE on all hydrological processes with increasing slope steepness. Distinct differences and magnitudes between different land cover types, different elevations, and, in particular, different exposition were quantified. Actual evapotranspiration increases with SAUE, while runoff decreases. April soil water is simulated to decrease with an increase in SAUE. Finally, a comparison of a streamflow simulation of a small and steep alpine watershed with and without consideration of the SAUE is carried out. The sloped area of the small watershed is under‐estimated by 20·9%, and the difference in simulated runoff is 12·3%. When the SAUE was not considered, runoff was simulated to be higher, the associated coefficient of determination was slightly lower, and the slope of the regression line was flatter. Copyright © 2010 John Wiley & Sons, Ltd.
Gelling process differences in reverse emulsion, in situ gelling polymeric materials for intracranial aneurysm embolization, formulated with injectable contrast agents
Authors: Riley Celeste M. , McLemore Ryan , Preul Mark C. , Vernon Brent L.
Published: October 2010

The use of liquid‐to‐solid curing materials for brain aneurysm embolization has become increasingly attractive, as liquid embolics can be delivered noninvasively and can potentially achieve a higher degree of aneurysm volume occlusion. This study was aimed at characterizing differences in the gelling process of a reverse emulsion, crosslinking polymer system formulated with different types of injectable contrast agents. The polymeric system consists of poly(propylene glycol) diacrylate (PPODA) and pentaerythritol tetrakis(3‐mercaptopropionate) (QT). These monomers undergo Michael‐type addition upon initiation by a basic, aqueous solution. Conray™ and Omnipaque™ 300, commercially available contrast agents, were pH‐adjusted to basic conditions and used as initiating solutions with the PPODA‐QT system. Material characteristics were identified through rheology and scanning electron microscopy (SEM). Results showed that Conray‐ and Omnipaque‐formulated materials progress through the gelling process uniquely, evidenced by distinctly different viscosity profiles and droplet distributions. These results indicate that Conray is more miscible with the PPODA‐QT organic phase. Greater solubility in the organic phase allows Conray‐formulated gels to have faster and more widespread reaction initiation kinetics when Conray and Omnipaque have the same pH. Omnipaque‐formulated gels require a higher pH for the material to solidify in a time frame comparable to Conray‐formulated gels. This discrepancy arises because the majority of reaction initiation sites in Omnipaque‐formulated gels occur at phase boundaries via hydroxide ion flux from emulsified droplets rather than from hydroxide ions that are solubilized and integrated within the PPODA‐QT organic phase. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Three‐dimensional tracking and temporal analysis of liposomal transport in live cells using bright‐field imaging
Authors: Tsai Feng‐Ching , Tai Lin‐Ai , Wang Yu‐Jing , Xiao Jian‐Long , Hsu Tsi‐Hsuan , Yang Chung‐Shi , Lee Chau‐Hwang
Published: October 2010

Gold nanoparticles (AuNPs) confined in liposomes of diameters around 200 nm produce strong scattering signal owing to surface plasmon resonance, and therefore bright‐field optical tracking of the AuNP‐encapsulating liposomes can be conducted in living cells. Using an optical profiling technique called noninterferometric wide‐field optical profilometry and a bright‐field tracking algorithm, the polynomial‐fit Gaussian weight method, we analyze three‐dimensional (3D) motion of such liposomes in living fibroblasts. The positioning accuracy in three dimensions is nearly 20 nm. We tag the liposome membranes with fibroblast growth factor‐1 and reveal the intracellular transportation processes toward or away from the nucleus. On the basis of a temporal analysis of the intracellular 3D trajectories of AuNP‐encapsulating liposomes, we identify directed and diffusive motions in the transportation processes. Microsc. Res. Tech., 2010. © 2010 Wiley‐Liss, Inc.
Seasonal flexibility in organ size in the Andean lizard Liolaemus moradoensis
Authors: Naya Daniel E. , Veloso Claudio , Sabat Pablo , Bozinovic Francisco
Published: October 2010

The understanding of animal functioning in fluctuating environments is a major goal of physiological and evolutionary ecology. In temperate terrestrial habitats, one of the most pervasive changes in environmental conditions is that associated with the seasonal change along the year. In this study, we describe the pattern of seasonal variation in the size of nine internal organs in the lizard Liolaemus moradoensis from the Andes Mountains of Central Chile. We observed that the size of digestive organs was greater during summer in comparison to other seasons. Dry masses of liver and fat bodies reached maximum values during summer and minimum during spring. We suspect that lowest spring values are related with build‐up costs of energetically expensive organs (e.g., digestive, muscle mass) at the end of the hibernation period. Dry mass of the heart and lungs did not show a clear pattern of variation, suggesting that cardiac and pulmonary performance were maintained throughout the year. The dry mass of kidneys was greater during winter than during summer, a result observed in other hibernating lizards but for which there is no clear explanation. Finally, the dry mass of testes showed a maximum value during autumn and a progressive reduction toward summer, indicating that reproduction occurs during autumn. When represented in a bivariate space, acquisition (digestive), distribution (heart, lungs and kidneys), storage (liver and fat bodies), and expenditure (testes) organs generate four clusters. In general terms, observed seasonal pattern of change in organ size is in agreement with those reported for other lizard species that inhabit highly fluctuating environments. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.
Magnetic resonance microscopy of the barramundi (Lates calcarifer) brain
Authors: Ullmann Jeremy F.P. , Cowin, Gary , Collin Shaun P.
Published: October 2010

Magnetic resonance imaging (MRI) is an established technique for morphological imaging of the central nervous system. Despite its prevalent use in a range of taxa, few studies exist on the brains of teleosts. In this study, we present a detailed analysis of a teleost brain using high‐resolution MRI. Images were acquired from a Bruker 16.4 T vertical magnet with a three‐dimensional flash T2*‐weighted image sequence. High contrast was obtained using Magnevist® and the following imaging parameters: a flip angle of 30°, a repetition time of 50 ms, an echo time of 14 ms, and an image matrix of 1024 × 400 × 400. The resulting isotropic resolution of 30 μm allowed us to thoroughly describe the architecture of the barramundi (Lates calcarifer) brain, including descriptions of nuclei, fiber tracts, and cellular layers. A good correspondence, both in contrast and morphology, was found between magnetic resonance images and Nissl‐stained brain sections, allowing for an analysis of the benefits and drawbacks of MRI and conventional histology. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc..
Tandem mass spectrometry of silver‐adducted ferrocenyl catalyst complexes
Authors: Martha Cornelius T. , van Zeist Willem‐Jan , Bickelhaupt F. Matthias , Irth Hubertus , Niessen Wilfried M. A.
Published: October 2010

Ferrocene is a popular template in material science due to its exceptional characteristics that offer the ability to optimize the selectivity and activity of catalysts by the addition of carefully selected substituents. In combinatorial catalyst development, the high susceptibility to electrophilic substitution reactions offers the opportunity for the rapid introduction of molecular diversity. Mass spectrometry (MS)‐based continuous‐flow systems can be applied to rapidly evaluate catalyst performance as well as to (provisionally) identify the introduced catalyst complexes. Herein, we describe the fragmentation characteristics of the [ferrocenyl bidentate + Ag]+ catalyst complexes in dedicated (high‐resolution) MSn experiments. The investigation of the fragmentation patterns of a selected number of catalyst classes is accompanied with a density functional theory investigation of fragmentation intermediates in order to assess the viability of a selected fragmentation mechanism. Copyright © 2010 John Wiley & Sons, Ltd.
Energy‐dependent dissociation of benzylpyridinium ions in an ion‐trap mass spectrometer
Authors: Zins Emilie‐Laure , Pepe Claude , Schröder Detlef
Published: October 2010

Benzylpyridinium ions, generated via electrospray ionization of dilute solutions of their salts in acetonitrile/water, are probed by collisional activation in an ion‐trap mass spectrometer. From the breakdown diagrams obtained, phenomenological appearance energies of the fragment ions are derived. Comparison of the appearance energies with calculated reaction endothermicities shows a reasonably good correlation for this particular class of compounds. In addition, the data indirectly indicate that at threshold the dissociation of almost all of the benzylpyridinium ions under study leads to the corresponding benzylium ions, rather than the tropylium isomers. Substituent effects on the fragmentation for a series of benzylpyridinium ions demonstrate that neither mass effects nor differences in density of states seriously affect the energetics derived from the ion‐trap experiments. Copyright © 2010 John Wiley & Sons, Ltd.
Phase I and II metabolites of speciogynine, a diastereomer of the mainKratomalkaloid mitragynine, identified in rat and human urine by liquid chromatography coupled to low‐ and high‐resolution linear ion trap mass spectrometry
Authors: Philipp Anika A. , Wissenbach Dirk K. , Weber Armin A. , Zapp Josef , Maurer Hans H.
Published: October 2010

Mitragyna speciosa(Kratomin Thai), a Thai medical plant, is misused as herbal drug of abuse. Besides the most abundant alkaloids mitragynine (MG) and paynantheine (PAY), several other alkaloids were isolated fromKratomleaves, among them the third abundant alkaloid is speciogynine (SG), a diastereomer of MG. The aim of this present study was to identify the phase I and II metabolites of SG in rat urine after the administration of a rather high dose of the pure alkaloid and then to confirm these findings using human urine samples afterKratomuse. The applied liquid chromatography coupled to low‐ and high‐resolution mass spectrometry (LC–HRMS‐MS) provided detailed information on the structure in the MSnmode particularly with high resolution. For the analysis of the human samples, the LC separation had to be improved markedly allowing the separation of SG and its metabolites from its diastereomer MG and its metabolites. In analogy to MG, besides SG, nine phase I and eight phase II metabolites could be identified in rat urine, but only three phase I and five phase II metabolites in human urine. These differences may be caused by the lower SG dose applied by the user ofKratompreparations. SG and its metabolites could be differentiated in the human samples from the diastereomeric MG and its metabolites comparing the different retention times determined after application of the single alkaloids to rats. In addition, some differences in MS2and/or MS3spectra of the corresponding diastereomers were observed. Copyright © 2010 John Wiley & Sons, Ltd.
Metabolic profiling of Escherichia coli by ion mobility‐mass spectrometry with MALDI ion source
Authors: Dwivedi Prabha , Puzon Geoffery , Tam Maggie , Langlais Denis , Jackson Shelley , Kaplan Kimberly , Siems William F. , Schultz Albert J. , Xun Luying , Woods Amina , Hill Herbert H.
Published: October 2010

Comprehensive metabolome analysis using mass spectrometry (MS) often results in a complex mass spectrum and difficult data analysis resulting from the signals of numerous small molecules in the metabolome. In addition, MS alone has difficulty measuring isobars and chiral, conformational and structural isomers. When a matrix‐assisted laser desorption ionization (MALDI) source is added, the difficulty and complexity are further increased. Signal interference between analyte signals and matrix ion signals produced by MALDI in the low mass region (<1500 Da) cause detection and/or identification of metabolites difficult by MS alone. However, ion mobility spectrometry (IMS) coupled with MS (IM–MS) provides a rapid analytical tool for measuring subtle structural differences in chemicals. IMS separates gas‐phase ions based on their size‐to‐charge ratio. This study, for the first time, reports the application of MALDI to the measurement of small molecules in a biological matrix by ion mobility‐time of flight mass spectrometry (IM‐TOFMS) and demonstrates the advantage of ion‐signal dispersion in the second dimension. Qualitative comparisons between metabolic profiling of the Escherichia coli metabolome by MALDI‐TOFMS, MALDI‐IM‐TOFMS and electrospray ionization (ESI)‐IM‐TOFMS are reported. Results demonstrate that mobility separation prior to mass analysis increases peak‐capacity through added dimensionality in measurement. Mobility separation also allows detection of metabolites in the matrix‐ion dominated low‐mass range (m/z < 1500 Da) by separating matrix signals from non‐matrix signals in mobility space. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis and characterization of a ‘fluorous’ (fluorinated alkyl) affinity reagent that labels primary amine groups in proteins/peptides
Authors: Qian Jiang , Cole Richard B. , Cai Yang
Published: October 2010

Strong non‐covalent interactions such as biotin‐avidin affinity play critical roles in protein/peptide purification. A new type of ‘fluorous’ (fluorinated alkyl) affinity approach has gained popularity due especially to its low level of non‐specific binding to proteins/peptides. We have developed a novel water‐soluble fluorous labeling reagent that is reactive (via an active sulfo‐N‐hydroxylsuccinimidyl ester group) to primary amine groups in proteins/peptides. After fluorous affinity purification, the bulky fluorous tag moiety and the long oligoethylene glycol (OEG) spacer of this labeling reagent can be trimmed via the cleavage of an acid labile linker. Upon collision‐induced dissociation, the labeled peptide ion yields a characteristic fragment that can be retrieved from the residual portion of the fluorous affinity tag, and this fragment ion can serve as a marker to indicate that the relevant peptide has been successfully labeled. As a proof of principle, the newly synthesized fluorous labeling reagent was evaluated for peptide/protein labeling ability in phosphate‐buffered saline (PBS). Results show that both the aqueous environment protein/peptide labeling and the affinity enrichment/separation process were highly efficient. Copyright © 2010 John Wiley & Sons, Ltd.
Augmented adherence and internalization of group A Streptococcus pyogenes to influenza A virus infected MDCK cells
Authors: Hafez Mohamed M. , Abdel‐Wahab Kouka S. E. , El‐Fouhil Daad F. I.
Published: October 2010

Respiratory tract infections are one of the leading causes of morbidity and mortality. There is considerable epidemiologic evidence that infection with respiratory viruses increases the incidence and severity of secondary bacterial complications. However, very limited number of studies were concerned with the mechanism behind such synergy. In this context, our study aimed to explore the interaction between Group A Streptococcus pyogenes (GAS) and Influenza A virus (IAV). Our results revealed that the GAS adherence and internalization into Madin‐Darby canine kidney (MDCK) cells markedly increased after IAV infection. When M6 protein defective mutant of GAS was used, the virus enhanced adherence and internalization was nearly abolished indicating the involvement of M protein binding sites on the MDCK cell surface. Interestingly, the modulation of some O‐linked glycolproteins as well as sialic acid, mucin and fibrinogen‐like residues on the surface of MDCK cells contributed to augmented bacterial adherence and/or internalization. In the same way, qRT‐PCR experiments showed an overexpression of the membrane associated mucin (MUC1) on the surface of the MDCK cells after IAV infection. Altogether, the present study revealed that IAV infection augments the adherence and internalization of GAS to MDCK cells via modulation of membrane associated O‐linked glycoproteins, fibrinogen, sialic acid residues and the mucin, MUC1 on the surface of MDCK cell. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metamorphosis of Borrelia burgdorferi organisms – RNA, lipid and protein composition in context with the spirochetes' shape
Authors: Al‐Robaiy Samiya , Dihazi Hassan , Kacza Johannes , Seeger Johannes , Schiller Jürgen , Huster Daniel , Knauer Jens , Straubinger Reinhard K.
Published: October 2010

Borrelia burgdorferi, the agent of Lyme borreliosis, has the ability to undergo morphological transformation from a motile spirochetal to non‐motile spherical shape when it encounters unfavorable conditions. However, little information is available on the mechanism that enables the bacterium to change its shape and whether major components of the cells – nucleic acids, proteins, lipids – are possibly modified during the process. Deducing from investigations utilizing electron microscopy, it seems that shape alteration begins with membrane budding followed by folding of the protoplasmatic cylinder inside the outer surface membrane. Scanning electron microscopy confirmed that a deficiency in producing functioning periplasmic flagella did not hinder sphere formation. Further, it was shown that the spirochetes' and spheres' lipid compositions were indistinguishable. Neither phosphatidylcholine nor phosphatidylglycerol were altered by the structural transformation. In addition, no changes in differential protein expression were detected during this process. However, minimal degradation of RNA and a reduced antigen‐antibody binding activity were observed with advanced age of the spheres. The results of our comparisons and the failure to generate mutants lacking the ability to convert to spheres suggest that the metamorphosis of B. burgdorferi results in a conditional reconstruction of the outer membrane. The spheres, which appear to be more resistant to unfavorable conditions and exhibit reduced immune reactivity when compared to spirochetes, might allow the B. burgdorferi to escape complete clearance and possibly ensure long‐term survival in the host. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)