bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring the timing of snowmelt and the initiation of streamflow using a distributed network of temperature/light sensors
Authors: Lyon Steve W. , Troch Peter A. , Broxton Patrick D. , Molotch Noah P. , Brooks Paul D.
Published: October 2008

The loss of snow cover and the initiation of streamflow are key triggers for both terrestrial and aquatic biota. Landscape‐scale snowmelt and streamflow dynamics are difficult to estimate, however, because they integrate large spatial extents and can vary rapidly in time. Remotely sensed observations are often temporally discontinuous and point observations lack sufficient spatial density (e.g. point measures from data‐logging piezometers). In this study, we employ inexpensive temperature/light sensors to monitor the distribution of snowmelt and headwater stream discharge as a proxy for hydrological state of the landscape with high spatial and temporal resolution. This study was conducted at the Redondo Peak, a large (local relief over 1100 m) resurgent dome within the caldera complex of the Valles Caldera National Preserve, 30 km west of Los Alamos, New Mexico, USA. The first‐order streams that drain the Redondo Peak encompass the full spectrum of terrain aspects, resulting in significant variability in wind exposure, turbulent and radiative fluxes, snow cover duration, and vegetation structure. Complex interactions between these variables impact groundwater recharge through variations in sublimation, evaporation, and transpiration. To monitor the role this variation plays with respect to spatio‐temporal dynamics of snowmelt and headwater stream discharge, we have installed 128 temperature/light sensors in eight different streambeds draining through unique aspects of the peak. The variation of daily temperature/light levels relative to seasonal change in mean temperature/light levels provides a metric of the spatial distribution of surface waters and snow cover. This metric correctly identified flowing lengths of headwater streams with 80% accuracy during an early summer period (10 May 2007) and 79% of the time in late summer period (2 October 2007). Between these two observation periods, the percentage length of headwater streams flowing decreased by 12%, indicating a general drying of the landscape. On the basis of a conceptual model of a groundwater ‘mound’ within the peak that roughly follows the shape of the land surface, such a metric relates directly to the amount of water in the landscape, providing insight to the complex ecohydrological interactions between snowmelt, rainfall, and vegetative uptake. This serves as a precursor to developing a broader ecohydrological perspective of the interrelationships between ecology and hydrological processes. Copyright © 2008 John Wiley & Sons, Ltd.
Mountain ecohydrology: quantifying the role of vegetation in the water balance of montane catchments
Authors: Brooks P. D. , Vivoni Enrique R.
Published: October 2008

This paper introduces the special issue focused on mountain ecohydrology of the southwestern United States. The papers in this issue present initial results from a multi‐disciplinary observatory effort coordinated by the NSF Science and Technology Center for the Sustainability of Semi‐arid Hydrology and Riparian Areas (SAHRA). These studies contribute to an effort to understand how changes in vegetation affect basin‐scale water balance and water availability, and explicitly address major knowledge gaps in: (1) understanding of the role of vegetation in the partitioning precipitation into evaporation, sublimation, transpiration, soil moisture, streamflow and recharge, and (2) the ability to represent process understanding, obtained at the plant or plot scale, at the scale of catchments or basins. Copyright © 2008 John Wiley & Sons, Ltd.
New Bis(amino)cyclodiphosph(III)azane Complexes of Aluminum
Authors: Rastätter Marcus , Roesky Peter W.
Published: October 2008

The reaction of the bis(amino)cyclodiphosph(III)azane cis‐{(tBuNH)2(PNtBu)2} with AlEt3, AlBrEt2, AlBr2Et, and AlBr3 was investigated. The less Lewis acidic compound AlEt3 forms the adduct cis‐[(tBuNH)2(PNtBu){P(·AlEt3)NtBu}], in which the aluminum atom is exclusively coordinated to one phosphorus atom. No ethane elimination was observed. By using the more Lewis acidic compounds AlBr2Et and AlBr3 the N‐coordinated complexes cis‐[(tBuNH)(PNtBu)(tBuN·AlBr2Et){P(H)NtBu}] and cis‐[(tBuNH)(PNtBu)(tBuN·AlBr3){P(H)NtBu}] were obtained, in which the aluminum atoms are N‐coordinated by a tBuN=PH unit. Upon coordination of the aluminum compounds, a concomitant 1,2‐H shift from the nitrogen atom onto the phosphorus atom within the cis‐{(tBuNH)2(PNtBu)2} ligand was observed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis of α‐Amino Acids by Umpolung of Weinreb Amide Enolates
Authors: Hirner Sebastian , Kirchner Donata K. , Somfai Peter
Published: October 2008

An efficient and diastereoselective synthesis of α‐amino acids from readily available starting materials has been developed. The key feature of this reaction is an umpolung of a glycine‐derived enolate, providing an alternative approach for the synthesis of α‐amino acids. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis of Two Tetra‐ and Four Pentasaccharide Fragments of Shigella flexneri Serotypes 3a and X O‐Antigens from a Common Tetrasaccharide Intermediate
Authors: Boutet Julien , Mulard Laurence A.
Published: October 2008

Relying on trichloroacetimidate chemistry, six tetra‐ and pentasaccharide fragments of the {2)‐[α‐D‐Glcp‐(1→3)]‐α‐L‐Rhap‐(1→2)‐α‐L‐Rhap‐(1→3)‐[Ac→2]‐α‐L‐Rhap‐(1→3)‐β‐D‐GlcpNAc‐(1→}n ((E)ABAcCD)n polymer were synthesized as their propyl glycosides by use of a common fully protected (E)ABAcC intermediate (9). Tetrasaccharide 9 derived from the condensation of an EA donor and a BAcC acceptor. Partial and full deprotection gave free tetrasaccharides (E)ABAcC and (E)ABC, respectively. Alternatively, 9 was converted into a trichloroacetimidate donor, which provided linear pentasaccharides (E)ABAcCD and (E)ABCD, following a reaction with a D acceptor and subsequent partial or total deprotection, respectively. Additionally, the selective removal of the 2A‐levulinoyl protecting group in 9 allowed for chain elongation at this position. The glycosylation of the resulting acceptor with a D donor, and subsequent partial or total deprotection, gave branched pentasaccharides D(E)ABAcC and D(E)ABC. All targets are parts of the O‐antigen of Shigella flexneri 3a, a prevalent serotype. Non‐O‐acetylated oligosaccharides are shared by the S. flexneri serotype X O‐antigen. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Silver‐Catalyzed, Manganese‐Mediated Allylation and Benzylation Reactions of Aldehydes and Ketones
Authors: Barczak Nicholas T. , Jarvo Elizabeth R.
Published: October 2008

Silver bromide catalyzes Barbier‐type allylation of aldehydes and ketones using unactivated manganese powder. Aliphatic and aromatic aldehydes and ketones react, and aryl chlorides, nitriles, electron‐donating and electron‐withdrawing groups are tolerated. Benzylation using benzyl bromide also proceeds smoothly under these reaction conditions. Preliminary mechanistic studies are consistent with the formation a nucleophilic allylmetal intermediate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Model averaging to combine simulations of future global vegetation carbon stocks
Authors: Butler Adam , Doherty Ruth M. , Marion Glenn
Published: October 2008

We quantify the impact of climate model uncertainty upon predictions of future vegetation carbon stocks, for the period up to 2100, generated by a dynamic global vegetation model (DGVM) under a particular emissions scenario (SRES A2). Deterministic simulations are generated from the Lund‐Potsdam‐Jena (LPJ) model using climatic inputs derived from nine general circulation models (GCMs). Simulated changes between 1961–1990 and 2070–2099 range from +26 to +133 gtC, and are in broadly good agreement with those obtained in a recent previous study using the LPJ model. Simulated values for the 20th century are also obtained by running LPJ with observed climate data, and this provides a baseline against which the other runs can be compared. Time series regression models are used to analyse the discrepancies between each of the GCM‐based simulations and the baseline simulation, and a novel form of model averaging—in which we average not only across GCM‐based simulations but also across models for each discrepancy—is then used to combine these into a single probabilistic projection for global stocks of vegetation carbon. Weights for the regression models are estimated in a simple post hoc way using the Bayesian information criterion (BIC), and the weights for the GCMs are either estimated in the same way or else fixed to be equal. Estimating the GCM weights leads the predictions to be dominated by a single climate model and hence produces narrow predictive distributions. If GCMs are weighted equally then the predictive distributions are much more diffuse and span the full range of simulated values. Copyright © 2008 John Wiley & Sons, Ltd.
Review: Alternative energy from food processing wastes
Authors: Digman Brett , Kim Dong‐Shik
Published: October 2008

Food processes generate large amounts of various waste types. The environmental impact of these wastes is generally high if disposed untreated due to their high BOD and COD contents. By utilizing the high potential energy available in food processing wastes, sustainable energy can be obtained while reducing the waste disposal costs and impact on the environment. According to the unique compositions of various food processing wastes, proper conversion methods must be selected to optimize the economic and environmental benefits. In this review, food processing wastes are categorized in six groups, and various energy conversion technologies are addressed in association with them. Future direction for better utilizing food process wastes in alternative energy generation is also suggested. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Prognostic factors in malignancy of the minor salivary glands
Authors: Loh Kwok Seng , Barker Emma , Bruch Guillem , O'Sullivan Brian , Brown Dale H. , Goldstein David P. , Gilbert Ralph W. , Gullane Patrick J. , Irish Jonathan C.
Published: October 2008

Background

The purpose of this study was to identify prognostic factors associated with minor salivary gland malignancies.

Method

This was a retrospective study of 171 patients. Statistical analysis of both clinical and pathological parameters with survival outcomes was performed.

Results

Adenoid cystic carcinoma (46.8%), mucoepidermoid carcinoma (22.8%), and adenocarcinoma (18.7%) were the most common pathologies. The most frequent sites of primary tumor were in the oral cavity (44.4%) and nasal cavity (40.4%). The 5‐year and 10‐year overall survivals were 73.8% and 58.1%. Disease‐specific survivals (DSS) were 78.2% and 66.7% and disease‐free survivals (DFS) were 64.8% and 47.5%, respectively. Local recurrence rate was 26.9%, regional recurrence 7%, and distant failure was 18.7%. The grade of tumor was the only factor associated with DSS on multivariate analysis.

Conclusion

Overall and DSS of minor salivary gland malignancies were good. Surgery, either alone or in combination with radiation, was an efficacious treatment modality. High‐grade tumors were associated with worse DSF. © 2008 Wiley Periodicals, Inc. Head Neck, 2009
Malignant fibrous histiocytoma of the sinonasal tract
Authors: Wang Cheng‐Ping , Chang Yih‐Leong , Ting Lai‐Lei , Yang Tsung‐Lin , Ko Jenq‐Yuh , Lou Pei‐Jen
Published: October 2008

Background

Sinonasal malignant fibrous histiocytoma (MFH) is rare.

Methods

Twenty‐five patients were registered with a diagnosis of sinonasal MFH at our hospital in the past 30 years. Clinical data were retrospectively reviewed.

Results

Eight tumors were primary MFH and 17 tumors were post‐irradiated MFH, located within the radiation field for previous nasopharyngeal carcinoma. Twenty‐one tumors originated from the maxillary sinus, 3 from the nasopharynx, and 1 from the nasal cavity. Twenty‐three patients underwent surgery but only 12 tumors were removed completely. The 5‐year overall and disease‐free survival rates were 25.1% and 21.5%, respectively. Multivariate analyses showed that previous radiation was the only adverse prognostic factor for disease‐free survival (p = .045). The 5‐year disease‐free survival rates of primary MFH and post‐irradiated MFH were 72.9% and 0%.

Conclusion

In this series, post‐irradiated MFH was more common than primary MFH. The prognosis of post‐irradiated MFH is poor, whereas primary MFH is fair. © 2008 Wiley Periodicals, Inc. Head Neck, 2009
Postradiotherapy neck dissection for head and neck squamous cell carcinoma: Pattern of pathologic residual carcinoma and prognosis
Authors: Lango Miriam N. , Andrews Genevieve A. , Ahmad Sidrah , Feigenberg Steven , Tuluc Madalina , Gaughan John , Ridge John A.
Published: October 2008

Background

For patients with head and neck cancer who were treated using primary radiotherapeutic approaches, the pattern of pathologic residual carcinoma in the neck dissection specimen and its effect on clinical outcome remains unknown.

Methods

Medical records of 65 patients who underwent 71 neck dissections a median 7 weeks after radiotherapy were reviewed. Median follow‐up was 33 months.

Results

Residual cancer, identified in 28 patients (43%), diminished locoregional control (p = .018), recurrence‐free (p = .018), and overall survival (p = .02). Thirteen patients (20%) had 2 or more pathologically involved lymph nodes. Nine (13%) involved level V. Four (6%) had pathologic involvement of nodal levels not clinically involved by cancer before treatment. In N2‐3 patients with positive pathologic specimens, the presence of these factors diminished recurrence‐free survival (p = .01). The outcome of patients with pathologic carcinoma but without such ominous factors approached those with negative pathology.

Conclusions

For patients with residual carcinoma in the neck following radiation, the pattern of residual disease is an effective predictor of recurrence © 2008 Wiley Periodicals, Inc. Head Neck, 2009
Using controlled clinical trials to learn more about acute drug-induced liver injury
Authors: Watkins Paul B. , Seligman Paul J. , Pears John S. , Avigan Mark I. , Senior John R.
Published: October 2008

Drug-induced liver injury (DILI) is of major interest to hepatologists and clinicians in general, patients, government regulators, and the pharmaceutical industry. Understanding why this form of injury occurs only in certain individuals has major implications for the development and availability of drug therapies and in the prevention of these events. A single controlled clinical trial may be unlikely to show cases of such rare events, but in the aggregate, clinical trials offer a unique resource for learning more about individual susceptibility and developing truly predictive new biomarkers for DILI. We pose the question as to whether clinical trials could be modified or improved to provide data that would better answer some of the outstanding issues. At a recent (March 2008) public meeting, experts from academia, industry, and regulatory bodies discussed several major issues regarding liver safety in clinical trials including: what signals of liver injury should justify stopping administration of study drug or allowing it to continue; if deliberate rechallenge should be done and under what circumstances; whether patients with liver disease should be included in clinical trials; and what kinds of new biomarkers will be needed to answer these questions more clearly. Past clinical trials have not provided data to settle those issues, and reliance has defaulted to consensus of expert opinions. Modified and better clinical trials with standardized collection of data and biospecimens are probably the best source of new and potentially valuable information to supplant current rules based on consensus of expert opinions and to understand by what mechanisms and how to distinguish those individuals who are susceptible to severe DILI. (Hepatology 2008.)
Sexual behavior modulates contextual fear memory through dopamine D1/D5 receptors
Authors: Bai Hua‐Yi , Cao Jun , Liu Na , Xu Lin , Luo Jian‐Hong
Published: October 2008

Traumatic events always lead to aversive emotional memory, i.e., fear memory. In contrast, positive events in daily life such as sex experiences seem to reduce aversive memory after aversive events. Thus, we hypothesized that post‐traumatic pleasurable experiences, especially instinctive behaviors such as sex, might modulate traumatic memory through a memory competition mechanism. Here, we first report that male rats persistently expressed much lower fear responses when exposed to females, but not when exposed to males, for 24 h immediately after contextual fear conditioning. Remarkably, this effect of sexual behavior was blocked by either systemic or intrahippocampal injection of the dopamine D1/D5 receptor antagonist R(+)‐7‐chloro‐8‐hydroxy‐3‐methyl‐1‐phenyl‐2,3,4,5‐tetrahydro‐1H‐3‐benzazepine hydrochloride (SCH23390) and was mimicked by systemic but not intrahippocampal injection of the D1/D5 receptor agonist R(+)‐1‐phenyl‐2,3,4,5‐tetrahydro‐1H‐3‐benzazepine‐7,8‐diol hydrochloride (SKF39393). Furthermore, as a candidate mechanism underlying contextual fear memory, the impaired induction of hippocampal long‐term potentiation (LTP) elicited by conditioned fear was rescued in male rats immediately exposed to female but not male rats for 24 h. Systemic injection of the dopamine D1/D5 receptor antagonist SCH23390 or agonist SKF38393 prevented or mimicked the effect of sexual behavior on the impaired induction of hippocampal LTP. Thus, our finding suggests that dopaminergic functions may, at least partially, govern competition between contextual fear and enjoyable memories through the modulation of hippocampal LTP. © 2008 Wiley‐Liss, Inc.
Alternating low frequency stimulation of medial septal and commissural fibers induces NMDA‐dependent, long‐lasting potentiation of hippocampal synapses in urethane‐anesthetized rats
Authors: Habib Diala , Dringenberg Hans C.
Published: October 2008

Recent evidence indicates that some synapses exhibit long‐lasting synaptic potentiation in response to low frequency (1 Hz) stimulation, similar to long‐term potentiation (LTP) following high frequency induction protocols. Here, the authors characterize a form of long‐lasting synaptic potentiation in the hippocampal CA1 area following alternating, single pulse stimulation of the medial septum (MS) and hippocampal CA3 commissural fibers (MS‐H LTP). In urethane‐anesthetized rats, alternating single pulse stimulation of the MS and CA3 (50 pulses each at 0.5 Hz, 1,000 ms interstimulus interval [ISI]) produced gradual increases of field excitatory postsynaptic potential (fEPSP) amplitude in CA1 (∼123% of baseline), while MS or CA3 stimulation alone was ineffective. The fEPSP enhancement was long‐lasting (>4h) and repeated episodes of alternating MS‐CA3 stimulation tended to result in greater levels of potentiation than those elicited by a single episode. Surprisingly, ISIs of 500, 750, and 1,500 ms did not result in significant changes in fEPSP amplitude, while an ISI of 100 ms produced synaptic depression. MS‐H LTP was resistant to systemic administration of nicotinic and muscarinic receptor antagonists (scopolamine, mecamylamine), but abolished by systemic MK‐801 (0.5 mg/kg, i.p.) or local CA1 application of AP‐V (10 mM), indicative of a critical role of hippocampal NMDA receptors in this effect. Paired‐pulse facilitation experiments revealed a gradually developing, significant inverse correlation between fEPSP enhancement and decrease in paired‐pulse facilitation ratio, suggesting a role of changes in presynaptic transmitter release. Together, these data demonstrate a novel form of long‐lasting synaptic enhancement in CA1 neurons in response to low frequency activity in separate afferent systems, an activity that might mimic some aspects of natural discharge patterns during the acquisition or consolidation of memory processes in hippocampal circuits. © 2008 Wiley‐Liss, Inc.
Primary twin ovarian pregnancy: Case report and review of the literature
Authors: Garg Mandeep Kumar , Vyas Sameer , Gulati Ajay , Galwa Ram Prakash , Khandelwal Niranjan
Published: October 2008

Primary twin ovarian pregnancy is extremely rare. We present one such case in a 25‐year‐old primigravida who complained of lower abdominal pain and mild vaginal bleeding at 8 weeks after her last menstrual period. Transvaginal sonography revealed an empty uterus and presence of a gestational sac containing 2 dead embryos in the right ovary. The patient underwent unilateral oophorectomy, and histologic studies confirmed a uniovular‐diamniotic ovarian pregnancy. A brief review of the literature revealed that primary ovarian pregnancy may occur without any classical antecedent risk factors, and endovaginal sonography can be useful to establish early preoperative diagnosis of ectopic ovarian pregnancy. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound 2009
The cell migration protein Grb7 associates with transcriptional regulator FHL2 in a Grb7 phosphorylation‐dependent manner
Authors: Siamakpour‐Reihani Sharareh , Argiros Haroula J. , Wilmeth Lori J. , Haas L. Lowell , Peterson Tabitha A. , Johnson Dennis L. , Shuster Charles Brad , Lyons Barbara A.
Published: October 2008

Grb7 is an adaptor molecule that can mediate signal transduction from multiple cell surface receptors to various downstream signaling pathways. Grb7, along with Grb10 and Grb14, make up the Grb7 protein family. This protein family has been shown to be overexpressed in certain cancers and cancer cell lines. Grb7 and a receptor tyrosine kinase (RTK), erbB2, are overexpressed in 20–30% of breast cancers. Grb7 overexpression has been linked to enhanced cell migration and metastasis, though the participants in these pathways have not been determined. In this study, we report that Grb7 interacts with four and half lim domains isoform 2 (FHL2), a transcription regulator with an important role in oncogenesis, including breast cancer. Additionally, in yeast 2‐hybrid (Y2H) assays, we show that the interaction is specific to the Grb7 RA and PH domains. We have also demonstrated that full‐length (FL) Grb7 and FHL2 interact in mammalian cells and that Grb7 must be tyrosine phosphorylated for this interaction to occur. Immunofluorescent microscopy demonstrates possible co‐localization of Grb7 and FHL2. A model with supporting NMR evidence of Grb7 autoinhibition is proposed. Copyright © 2008 John Wiley & Sons, Ltd.
Interaction between the CBM of Cel9A from Thermobifida fusca and cellulose fibers
Authors: Oliveira Osmair V. , Freitas Luiz C. G. , Straatsma T. P. , Lins Roberto D.
Published: October 2008

Molecular docking and molecular dynamics (MD) simulations were used to investigate the binding of a cellodextrin chain in a crystal‐like conformation to the carbohydrate‐binding module (CBM) of Cel9A from Thermobifida fusca. The fiber was found to bind to the CBM in a single and well‐defined configuration in‐line with the catalytic cleft, supporting the hypothesis that this CBM plays a role in the catalysis by feeding the catalytic domain (CD) with a polysaccharide chain. The results also expand the current known list of residues involved in the binding. The polysaccharide‐protein attachment is shown to be mediated by five amine/amide‐containing residues. E478 and E559 were found not to interact directly with the sugar chain; instead they seem to be responsible to stabilize the binding motif via hydrogen bonds. Copyright © 2008 John Wiley & Sons, Ltd.
Structural characterization of in vitro rat liver microsomal metabolites of antihistamine desloratadine using LTQ‐Orbitrap hybrid mass spectrometer in combination with online hydrogen/deuterium exchange HR‐LC/MS
Authors: Chen Guodong , Daaro Ibrahim , Pramanik Birendra N. , Piwinski John J.
Published: October 2008

In vitro drug metabolism study is an integral part of drug discovery process. In this report, we have described the application of LTQ‐Orbitrap hybrid mass spectrometer in conjunction with online hydrogen (H)/deuterium (D) exchange high resolution (HR)‐LC/MS for structural characterization of in vitro rat liver microsomal metabolites of antihistamine desloratadine. Five metabolites M1M5 have been identified, including three hydroxylated metabolites M1M3, one N‐oxide M4 and one uncommon aromatized N‐oxide M5. Accurate mass data have been obtained in both full scan and MSn mode support assignments of metabolite structures with reported mass errors less than 3 ppm. Online H/D exchange HR‐LC/MS experiments provide additional evidence in differentiating hydroxylated metabolites from N‐oxides. This study demonstrates the effectiveness of this approach in structural characterization of drug metabolites. Copyright © 2008 John Wiley & Sons, Ltd.
Stimulation of choline acetyltransferase by C3d, a neural cell adhesion molecule ligand
Authors: Burgess Alison , Saini Saumya , Weng Ying‐Qi , Aubert Isabelle
Published: October 2008

Septal cholinergic neurons project to the hippocampus and release acetylcholine, a neurotransmitter involved in learning and memory. The enzyme choline acetyltransferase (ChAT) is responsible for synthesizing acetylcholine. Promoting ChAT activity and acetylcholine release can lead to new treatments for neurodegenerative diseases with cholinergic deficits, such as Alzheimer's disease. We present evidence that the synthetic molecule C3d, which is a peptide mimetic of the neural cell adhesion molecule (NCAM), promotes ChAT activity in cultures of rat embryonic septal neurons. Our data demonstrate that ChAT activity triggered by C3d is dependent on the fibroblast growth factor receptor (FGFR) and the mitogen‐activated protein kinase (MAPK) pathway. C3d did not affect the number of cholinergic neurons in culture, indicating that NCAM homophilic binding enhances ChAT activity, without affecting cholinergic cell survival. In conclusion, the NCAM mimetic peptide C3d promotes ChAT activity in septal neurons through FGFR and MAPK. These findings are relevant to the design of new strategies aimed at stimulating cholinergic function and improving cognition in disorders such as Alzheimer's disease. © 2008 Wiley‐Liss, Inc.
Nicotine attenuates iNOS expression and contributes to neuroprotection in a compressive model of spinal cord injury
Authors: Lee Mee‐Young , Chen Lei , Toborek Michal
Published: October 2008

Primary impact to the spinal cord results in stimulation of secondary processes that potentiate the initial trauma. In the present study, we hypothesized that the altered expression of nitric oxide synthase (NOS) may contribute to these effects. Recent evidence indicates that nicotine can exert potent antioxidant and neuroprotective effects in spinal cord injury (SCI). Therefore, the aim of the present study was to evaluate whether the administration of nicotine can influence expression of inducible NOS (iNOS) and/or neuronal NOS (nNOS) in injured spinal cords. Adult male Long‐Evans rats were subjected to a moderate contusion model of SCI and received a single intraperitoneal injection of either saline or nicotine (0.35, 3.5, or 7 mg/kg) 2 hr after trauma. SCI dramatically increased iNOS (but not nNOS) mRNA and protein levels in microglial cells in the thoracic and lumbar regions of spinal cords. iNOS overexpression resulted in increased nitrotyrosine formation, decreased number of NeuN (neuronal nuclei)–immunoreactive cells, and up‐regulation of inflammatory genes. Most importantly, these effects were markedly attenuated by nicotine acting via a receptor‐mediated mechanism. These data may have significant therapeutic implications for the targeting of nicotine receptors in the treatment of compressive spinal cord trauma. © 2008 Wiley‐Liss, Inc.
Oxidative stress promotes proliferation and dedifferentiation of retina glial cells in vitro
Authors: Abrahan Carolina E. , Insua M. Fernanda , Politi Luis E. , German O. Lorena , Rotstein Nora P.
Published: October 2008

Oxidative damage is involved in triggering neuronal death in several retinal neurodegenerative diseases. The recent finding of stem cells in the retina suggests that both preventing neuronal death and replacing lost neurons might be useful strategies for treating these diseases. We have previously shown that oxidative stress induces apoptosis in cultured retinal neurons. We now investigated the response of Müller cells, proposed as retina stem cells, to this damage. Treatment of glial cell cultures prepared from rat retinas with the oxidant paraquat (PQ) did not induce glial cell apoptosis. Instead, PQ promoted their rapid dedifferentiation and proliferation. PQ decreased expression of a marker of differentiated glial cells, simultaneously increasing the expression of smooth muscle actin, shown to increase with glial dedifferentiation, the levels of cell‐cycle markers, and the number of glial cells in the cultures. In addition, glial cells protected neurons in coculture from apoptosis induced by PQ and H2O2. In pure neuronal cultures, PQ induced apoptosis of photoreceptors and amacrine neurons, simultaneously decreasing the percentage of neurons preserving mitochondrial membrane potential; coculturing neurons with glial cells completely prevented PQ‐induced apoptosis and preserved mitochondrial potential in both neuronal types. These results demonstrate that oxidative damage activated different responses in Müller glial cells; they rapidly dedifferentiated and enhanced their proliferation, concurrently preventing neuronal apoptosis. Glial cells might not only preserve neuronal survival but also activate their cell cycle in order to provide a pool of new progenitor cells that might eventually be manipulated to preserve retinal functionality. © 2008 Wiley‐Liss, Inc.
A Na+/Ca2+exchanger isoform, NCX1, is involved in retinal cell death afterN‐methyl‐D‐aspartate injection and ischemia–reperfusion
Authors: Inokuchi Y. , Shimazawa M. , Nakajima Y. , Komuro I. , Matsuda T. , Baba A. , Araie M. , Kita S. , Iwamoto T. , Hara H.
Published: October 2008

We investigated the expression of Na+/Ca2+exchanger (NCX) and the functional role of NCX in retinal damage by using NCX1‐heterozygous deficient mice (NCX1+/−) and SEA0400 (2‐[4‐[(2,5‐difluorophenyl)methoxy] phenoxy]‐5‐ethoxyaniline), a selective NCX inhibitor in vivo. We also examined the role of NCX in oxygen–glucose deprivation (OGD) stress with a retinal ganglion cell line (RGC‐5) cell culture in vitro. The expression of NCX1 was confirmed and entirely localized in retina by immunoblotting and immunohistochemistry, respectively. NCX1+/−mice possessed significant protection against retinal damage induced by intravitreal injection ofN‐methyl‐D‐aspartate (NMDA). SEA0400 at 3 and 10 mg/kg significantly reduced NMDA‐ or high intraocular pressure–induced retinal cell damage in mice. Furthermore, SEA0400 reduced the number of TUNEL (terminal deoxynucleotidyl transferase dUTP nick‐end labeling)‐positive cells and the expression of phosphorylated mitogen‐activated protein kinases (ERK1/2, JNK, p38) induced by NMDA injection. In RGC‐5, SEA0400 at 0.3 and 1 μM significantly inhibited OGD‐induced cell damage. OGD‐induced cell damage was aggravated by ouabain (a Na+,K+‐ATPase inhibitor) at 100 μM, and this increased damage was significantly reduced by SEA0400 at 1 μM. In conclusion, these results suggest that NCX1 may play a role in retinal cell death induced by NMDA and ischemia–reperfusion. © 2008 Wiley‐Liss, Inc.
The fate of transplanted xenogeneic bone marrow‐derived stem cells in rat intervertebral discs
Authors: Wei Aiqun , Tao Helen , Chung Sylvia A. , Brisby Helena , Ma David D. , Diwan Ashish D.
Published: October 2008

Intervertebral disc degeneration is a major cause and a risk factor for chronic low back pain. The potential of using stem cells to treat disc degeneration has been raised. The aims of our study were to assess whether xenogeneic bone‐marrow derived stem cells could survive in a rat disc degeneration model and to determine which cell types, if any, survived and differentiated into disc‐like cells. Human bone‐marrow derived CD34+ (hematopoietic progenitor cells) and CD34− (nonhematopoietic progenitor cells, including mesenchymal stem cells) cells were isolated, fluorescent‐labeled, and injected into rat coccygeal discs. The rats were sacrificed at day 1, 10, 21, and 42. Treated discs were examined by histological and immunostaining techniques and compared to control discs. The survival of transplanted cells was further confirmed with a human nuclear specific marker. Fluorescent labeled CD34− cells were detected until day 42 in the nucleus pulposus of the injected discs. After 3 weeks these cells had differentiated into cells expressing chondrocytic phenotype (Collagen II and Sox‐9). In contrast, the fluorescent labeled CD34+ cells could not be detected after day 21. No fluorescence‐positive cells were detected in the noninjected control discs. Further, no inflammatory cells infiltrated the nucleus pulposus, even though these animals had not received immunosuppressive treatment. Our data provide evidence that transplanted human BM CD34− cells survived and differentiated within the relative immune privileged nucleus pulposus of intervertebral disc degeneration. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:374–379, 2009
Enhancement of posterolateral lumbar spine fusion using low‐dose rhBMP‐2 and cultured marrow stromal cells
Authors: Fu Tsai‐Sheng , Chen Wen‐Jer , Chen Lih‐Huei , Lin Song‐Shu , Liu Shih‐Jung , Ueng Steve W.N.
Published: October 2008

We tested the hypothesis that the dose of recombinant human bone morphogenetic protein‐2 (rhBMP‐2) required to induce spine fusion can be reduced by combination with mesenchymal stem cells (MSCs). Twenty‐four adult rabbits underwent posterolateral intertransverse fusion at the L4–L5 level. The animals were divided into four groups based on the implant material: autologous iliac graft, Alginate‐MSCs composite, Alginate‐BMP‐2‐MSCs composite, and Alginate‐BMP‐2 composite. After 16 weeks, the rabbits were euthanized for radiographic examination, manual palpation, biomechanical testing, and histology. Radiographic union of 12 intertransverse fusion areas for the autogenous iliac graft, Alginate‐MSCs, Alginate‐BMP‐2‐MSCs, and Alginate‐BMP‐2 groups was 11, 8, 11, and 0, respectively. Moreover, manual palpation of six fusion segments in each subgroup found solid union to be 6, 1, 5, and 0, respectively. The average torques at failure of the first three groups were 2278 ± 135, 1943 ± 140, and 2334 ± 187 N‐mm, respectively. The failure torque did not differ significantly between the autograft and Alginate‐BMP‐2‐MSCs groups; both groups were significantly higher than the Alginate‐MSCs group. The results indicate that MSCs delivered with in vitro cellular doses of rhBMP‐2 are more osteoinductive than MSCs without rhBMP‐2. In combination with MSCs, a low dose (2.5 µg) of rh‐BMP‐2 could enhance bone formation and posterolateral spine fusion success in the rabbit model. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:380–384, 2009
Identifying scapholunate ligamentous injury
Authors: Werner Frederick W. , Wang Haoyu , Short Walter H. , Sutton Levi G. , Rosenbaum Paula F.
Published: October 2008

The first purpose of this study was to develop a noninvasive clinical tool that could predict whether the scapholunate interosseous ligament and other secondary stabilizing ligaments are injured in the presence of suspected scapholunate instability. The second purpose of this study was to determine which of those ligaments or ligament groups have been injured. Kinematic and three‐dimensional (3D) meaurements from 62 cadaver wrists moved in a wrist joint motion simulator were used to develop various neural network predictive models. One group of models was based on angular changes in scaphoid and lunate motion before and after ligament sectioning (representing scapholunate instability). A second group of models was based on changes in the minimum distance between the scaphoid and lunate as well as other 3D gap measurements. The models, based on the scaphoid and lunate angular data, could predict with a 93% accuracy rate whether the wrist ligaments were intact. These models could also predict whether it was the dorsal ligaments or the volar ligaments that were sectioned 84% of the time. The models worked best using data with the wrist in 10 to 30 degrees of wrist flexion. The viability of a CT‐based predictive model has been demonstrated by obtaining high prediction rates, sensitivity, specificity, and kappa statistic values. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:394–399, 2009
High levels of glucosamine–chondroitin sulfate can alter the cyclic preload and acute overload responses of chondral explants
Authors: Wei Feng , Haut Roger C.
Published: October 2008

A recent study by our laboratory showed that 14 days of low intensity, intermittent cyclic preloading of chondral explants elevated the concentration of proteoglycans (PGs) to cause a mechanical stiffening of the explants prior to an acute overload and limit the extent of tissue damage. Longer term loading to 21 days resulted in tissue degradation prior to the acute traumatic event and excessive damage from an acute overload. Previous studies by others showed that bathing chondral explants in a supplement of glucosamine–chondroitin sulfate (glcN‐CS) upregulated the synthesis of tissue PGs, particularly in stressed tissue, and the supplement served as an anti‐inflammatory agent. Our current hypothesis was that the supplementation of culture media with a high concentration of glcN‐CS would upregulate the production of tissue PG and limit or mitigate long‐term degradation of chondral explants under cyclic preloading and limit tissue damage in an acute overload. We showed that, in the presence of supplement, cyclic preloading significantly increased tissue PG content and matrix modulus by about 65 and 300%, respectively, at 21 days, resulting in a reduction of matrix damage and cell death following an acute overload. These data show a biological action of high concentrations of this supplement and its effect on the mechanical properties in this in vitro model. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:353–359, 2009
How age impairs the response of the neuromuscular junction to nerve transection and repair: An experimental study in rats
Authors: Apel Peter J. , Alton Timothy , Northam Casey , Ma Jianjun , Callahan Michael , Sonntag William E. , Li Zhongyu
Published: October 2008

Age is the most important predictor of clinical outcome after peripheral nerve injury. The stability of the neuromuscular junction (NMJ) after denervation is thought to be central to neuromuscular recovery. Stability is characterized by maintenance of the motor endplate and mRNA upregulation of the constituent nicotinic acetylcholinergic receptor (nAChR) subtypes and the muscle regulatory factors (MRFs). The purpose of this study was to determine the effect of age on the recovery and stability of the postsynaptic NMJ after peripheral nerve injury. Young and aged rats underwent transection and repair of the tibial nerve. At 1, 2, 4, 8, or 16 weeks following transection, the gastrocnemius was examined for electrical recovery, NMJ fragmentation and endplate area, mRNA, and protein levels of the MRFs and nAChR subtypes. After nerve injury, aged NMJ exhibited significant fragmentation and loss of motor endplate area while the young NMJ remained relatively stable. Concomitantly, age impaired peak upregulation of the MRFs and nAChRs. However, expression of γ‐nAChR and myogenin after nerve injury was not affected by age. These data support the claim that upregulation of the nAChRs and MRFs may play an important role in maintaining NMJ stability following nerve transection and repair. Furthermore, expression of γ‐nAChR and myogenin does not appear to prevent age‐related NMJ fragmentation and loss of endplate area after nerve injury. These impairments of the aged NMJ response to injury may contribute to the poor neuromuscular recovery seen after nerve injury in this population. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:385–393, 2009
Healing ligament mechanical properties are improved by repair with interpositional allografts but not by concomitant treatment with hyaluronic acid
Authors: Thornton Gail M. , Shao Xinxin , Kuchison Marielle E. , Marchuk Linda L. , Shrive Nigel G. , Frank Cyril B.
Published: October 2008

Healing ligaments have inferior mechanical properties compared to normal ligaments during early healing intervals. The purpose of this study was to investigate if in vivo ligament repair with an interpositional allograft and treatment with hyaluronic acid (HA) would improve the mechanical properties of a medial collateral ligament (MCL) healing from a gap injury. Twenty rabbits were assigned equally to either a donor or recipient group. A gap injury of the MCL was created in both hindlimbs of 10 recipient animals. The right hindlimb was treated with allograft plus HA while the left hindlimb was treated with allograft only. Low‐load and high‐load mechanical properties, including laxity, relaxation and failure, and histology were evaluated after 6 weeks of healing. Mechanical results were compared to previously published normal MCL and MCL gap scar data. MCL allografts had greater initial force during cyclic relaxation testing and maximum force during failure testing than MCL scars, but were weaker than normal MCLs. Failure stress was the only parameter to demonstrate a statistically significant effect of treatment with HA on the allografts. However, the failure stress of the HA‐treated MCL allografts was not different than MCL scars and was less than normal MCLs. In conclusion, interpositional allografts could enhance some mechanical properties of ligament healing but HA, in the way we applied it, did not produce an obvious improvement. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:400–407, 2009
Customer access and competitive certainty: performance effects in Swedish foreign subsidiaries
Authors: Pehrsson Anders
Published: October 2008

This article extends our understanding of performance effects of expansion barriers in different strategy contexts relevant to industrial firms. Effects of perceived obstacles to customer access are studied, and competitive certainty is acknowledged since barriers to a large extent originate from business strategies of competitors.

The study explores patterns using data from subsidiaries of Swedish manufacturing firms in Germany, the United Kingdom, and the United States. For units with a narrow product/market scope, the direct performance effects of customer access obstacles and competitive certainty are negative.

On the other hand, in the narrow context competitive certainty moderates the relationship between customer access obstacles and performance, and this implicates a positive effect. There are no significant effects in the context of a broad product/market scope.

Performance effects of barriers are, thus, more complicated than previously thought, and we need to pay attention to perceived competitive certainty and the strategy context.

Copyright © 2008 John Wiley & Sons, Ltd.
Sustainable growth rates: refining a measure
Authors: Ashta Arvind
Published: October 2008

The purpose of this paper is to improve clarity and financial analysis for calculating a firm's sustainable growth rate, a useful concept for firms growing very fast as well as those in financial distress.

The paper is based on a review of literature and textbooks concerning the concept of sustainable growth rate.

The sustainable growth rate is the rate at which a company can grow without creating a cash flow problem, a concept developed by Robert C. Higgins in 1977 and in 1981 extended by him for continuous time frameworks. For discrete time frameworks, his textbook describes sustainable growth rates as a product of four ratios: the profit margin, the retention ratio, the asset turnover and the financial leverage ratio, of which the latter divides closing total assets by opening equity.

I agree with the components but suggest a slight modification. The leverage ratio should use the figures of the same date: it should use opening total assets divided by opening equity. Mathematically, this change would require modifying the asset turnover ratio to make it sales divided by opening total assets, instead of dividing by closing total assets as used by Higgins. This modification makes more intuitive sense since sales are created by assets rather than the other way round, which is far more indirect and remote and because of the timing problem.

The paper provides a simple illustration.

This modification would also require précising that the sustainable growth rate of firms in financial distress should use the asset turnover ratio using opening assets.

Copyright © 2008 John Wiley & Sons, Ltd.
Antioxidant properties and shelf‐life extension of fresh‐cut tomatoes stored at different temperatures
Authors: Odriozola‐Serrano Isabel , Soliva‐Fortuny Robert , Martín‐Belloso Olga
Published: October 2008

BACKGROUND: The feasibility of using modified atmosphere packaging (5 kPa O2 + 5 kPa CO2) to maintain the antioxidant properties of fresh‐cut tomatoes during shelf‐life was assessed through storage at different temperatures (5, 10, 15 and 20 °C). Health‐related compounds, antioxidant capacity, microbiological counts, physicochemical parameters and in‐package atmosphere of tomato slices were determined.

RESULTS: Initial lycopene, vitamin C and phenolic contents and physicochemical parameters of tomato slices were well maintained for 14 days at 5 °C. Lycopene and total phenolic contents were enhanced over time in tomato slices stored at 15 and 20 °C. However, this increase in antioxidant compounds of fresh‐cut tomatoes during storage may be associated with excessive amounts of CO2 (R2 = 0.5679–0.7328) in the packages due to microbial growth. Although keeping tomato slices at temperatures above 10 °C increased their antioxidant content, the shelf‐life of the product was reduced by up 4 days.

CONCLUSIONS: A storage temperature of 5 °C is appropriate for maintaining the microbiological shelf‐life of fresh‐cut tomatoes for up to 14 days and also allows the antioxidant properties of tomato slices to be retained over this period, thus reducing wounding stress and deteriorative changes. Copyright © 2008 Society of Chemical Industry
Hypocholesterolaemic and antioxidant effects of kombucha tea in high‐cholesterol fed mice
Authors: Yang Zhi‐Wei , Ji Bao‐Ping , Zhou Feng , Li Bo , Luo Yangchao , Yang Li , Li Tao
Published: October 2008

BACKGROUND: Traditional kombucha tea (TKT) is produced by mixed tea fungus. We previously proposed Gluconacetobacter sp. A4 as the key functional strain in kombucha culture, because it had strong ability to produce D‐saccharic acid‐1,4‐lactone (DSL, a crucial functional component in KT). This study investigated the hypocholesterolaemic and antioxidant activities of TKT and modified KT (MKT, tea broth fermented by single Gluconacetobacter sp. A4).

RESULTS: In vitro, TKT and MKT, but not DSL equally increased the radical scavenging effects and inhibited low density lipoprotein (LDL) oxidation. In vivo, the total cholesterol and LDL‐cholesterol (LDL‐C) lowering effects were not different between MKT and TKT. Compared with TKT, MKT showed a significantly elevated effect on the increase of antioxidantive enzymes activities (total antioxidant capacity and superoxide dismutase) and the decrease of malondialdehyde. Meanwhile DSL demonstrated an enhanced activity in lipid profile and antioxidant activities.

CONCLUSION: KT had the hypocholesterolaemic and antioxidant effects. These effects were largely attributed to DSL. MKT was similar to or even more powerful than TKT in antioxidant and hypocholesterolaemic effects. Thus, Gluconacetobacter sp. A4 was further established as the main functional microorganism in kombucha culture. Moreover, KT may be useful in treating obesity. Copyright © 2008 Society of Chemical Industry