bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutrient and Sediment Losses Under Simulated Rainfall Following Manure Incorporation by Different Methods
Authors: Little Joanne L. , Bennett D. Rodney , Miller Jim J.
Published: September 2005

Incorporation of manure into cultivated soils is generally recommended to minimize nutrient losses. A 3‐yr study was conducted to evaluate sediment and nutrient losses with different tillage methods (moldboard plow, heavy‐duty cultivator, double disk, and no‐incorporation) for incorporation of beef cattle manure in a silage barley (Hordeum vulgare L.) cropping system. Runoff depths, sediment losses, and surface and subsurface nutrient transfers were determined from manured and unmanured field plots at Lethbridge, Alberta, Canada. A Guelph rainfall simulator was used to generate 30 min of runoff. Sediment losses among our tillage treatments (137.4–203.6 kg ha−1) were not significantly different due to compensating differences in runoff depths. Mass losses of total phosphorus (TP) and total nitrogen (TN) in surface runoff were greatest from the no‐incorporation (NI) treatments, with reductions in TP loads of 14% for double disk (DD), 43% for cultivator (CU), and 79% for moldboard plow (MP) treatments. Total N load reductions in 2002 were 26% for DD, 70% for CU, and 95% for MP treatments compared to the NI treatments. Nutrient losses following incorporation of manure with the DD or CU methods were not significantly different from the NI treatments. Manure treatments generally had lower runoff depths and sediment losses, and higher phosphorus and nitrogen losses than the control treatments. Subsurface concentrations of NH4–N, NO3–N, and TN were greatest from the MP treatments, whereas subsurface phosphorus concentrations were not affected by tillage method. Tillage with a cultivator or double disk minimized combined surface and subsurface nutrient losses immediately after annual manure applications.
Phosphorus Cycling in Wetland Soils
Authors: Turner Benjamin L. , Newman Susan
Published: September 2005

Productivity in P limited peatlands is regulated in part by the turnover of organic phosphates, which is influenced by the chemical nature of the compounds involved. We used solution31P nuclear magnetic resonance (NMR) spectroscopy to quantify organic and inorganic phosphates in benthic floc (a mixture of plant detritus and algae) and underlying soil from sites along P gradients in hard water and soft water areas of the northern Florida Everglades, USA. Phosphorus‐enriched sites were dominated by cattail (Typhaspp.), while unenriched sites included sawgrass (Cladium jamaicenseCrantz) ridges and open‐water sloughs. Phosphorus extracted in a solution containing 0.25MNaOH and 50 mMEDTA (ethylenediaminetetraacetate) included phosphate, phosphate monoesters, DNA, and pyrophosphate. Signals from phosphate monoesters were consistent with those from alkaline hydrolysis products of RNA and phospholipids formed during extraction and analysis, whereas phytic acid (myo‐inositol hexakisphosphate), the most abundant organic phosphate in most soils, was not detected. Phosphorus composition was similar among sites, although neither DNA nor pyrophosphate were detected in extracts of benthic floc from a calcareous slough. DNA was a greater proportion of the P extracted from soil compared to benthic floc, while the opposite was true for pyrophosphate. Research on the cycling of organic phosphates in wetlands focuses conventionally on the turnover of phosphate monoesters, but our results suggest strongly that greater emphasis should be given to understanding the role of phosphate diesters and phosphodiesterase activity.
Soil Water Repellency Induced By Long‐Term Irrigation with Treated Sewage Effluent
Authors: Wallach R. , Ben‐Arie O. , Graber E. R.
Published: September 2005

This study describes soil water repellency developed under prolonged irrigation with treated sewage effluent in a semiarid environment. Soil surface layer (0–5 cm) and soil profile (0–50 cm) transects were sampled at a high resolution at the close of the irrigation season and rainy winter season. Samples from 0‐ to 5‐cm transects were subdivided into 1‐cm slices to obtain fine scale resolution of repellency and organic matter distribution. Extreme to severe soil water repellency in the 0‐ to 5‐cm soil surface layer persisted throughout the 2‐yr study period in the effluent‐irrigated Shamouti orange [Citrus sinensis (L.) Osbeck cv. Shamouti] orchard plot. Nearby Shamouti orange plots irrigated with tap water were either nonrepellent or only somewhat repellent. Repellency was very variable spatially and with depth, appearing in vertically oriented “repellency tongues.” Temporal and spatial variability in repellency in the uppermost 5‐cm soil surface layer was not related to seasonality, soil moisture content, or soil organic matter content. Nonuniform distribution of soil moisture and fingered flow were observed in the soil profile after both seasons, demonstrating that the repellent layer had a persistent effect on water flow in the soil profile. A lack of correlation between bulk density and volumetric water content in the soil profile demonstrates that the observed nonuniform spatial distribution of moisture results from preferential flow and not heterogeneity in soil properties. Soil water repellency can adversely affect agricultural production, cause contamination of underlying ground water resources, and result in excessive runoff and soil erosion.
Optimal design of batch‐storage network with multitasking semi‐continuous processes
Authors: Yi Gyeongbeom , Reklaitis Gintaras V.
Published: September 2005

The periodic square wave (PSW) model was successfully applied to the optimal design of a batch‐storage network. The network structure can cover any type of batch production, distribution, and inventory system, including recycle streams. Here we extend the coverage of the PSW model to multitasking semi‐continuous processes as well as pure continuous and batch processes. In previous solutions obtained using the PSW model, the feedstock composition and product yield were treated as known constants. This constraint is relaxed in the present work, which treats the feedstock composition and product yield as free variables to be optimized. This modification makes it possible to deal with the pooling problem commonly encountered in oil refinery processes. Despite the greater complexity that arises when the feedstock composition and product yield are free variables, the PSW model still gives analytic lot sizing equations. The ability of the proposed method to determine the optimal plant design is demonstrated through the example of a high density polyethylene (HDPE) plant. Based on the analytical optimality results, we propose a practical process optimality measure that can be used for any kind of process. This measure facilitates direct comparison of the performance of multiple processes, and hence is a useful tool for diagnosing the status of process systems. The result that the cost of a process is proportional to the square root of average flow rate is similar to the well‐known six‐tenths factor rule in plant design. © 2005 American Institute of Chemical Engineers AIChE J, 2006
A heuristic method based on a statistical approach for Chinese text segmentation
Authors: Yang Christopher C. , Li K. W.
Published: September 2005

The authors propose a heuristic method for Chinese automatic text segmentation based on a statistical approach. This method is developed based on statistical information about the association among adjacent characters in Chinese text. Mutual information of bi‐grams and significant estimation of tri‐grams are utilized. A heuristic method with six rules is then proposed to determine the segmentation points in a Chinese sentence. No dictionary is required in this method. Chinese text segmentation is important in Chinese text indexing and thus greatly affects the performance of Chinese information retrieval. Due to the lack of delimiters of words in Chinese text, Chinese text segmentation is more difficult than English text segmentation. Besides, segmentation ambiguities and occurrences of out‐of‐vocabulary words (i.e., unknown words) are the major challenges in Chinese segmentation. Many research studies dealing with the problem of word segmentation have focused on the resolution of segmentation ambiguities. The problem of unknown word identification has not drawn much attention. The experimental result shows that the proposed heuristic method is promising to segment the unknown words as well as the known words. The authors further investigated the distribution of the errors of commission and the errors of omission caused by the proposed heuristic method and benchmarked the proposed heuristic method with a previous proposed technique, boundary detection. It is found that the heuristic method outperformed the boundary detection method.
Word‐oriented approximate string matching using occurrence heuristic tables: A heuristic for searching Arabic text
Authors: Mustafa Suleiman H.
Published: September 2005

In this article, a word‐oriented approximate string matching approach for searching Arabic text is presented. The distance between a pair of words is determined on the basis of aligning the two words by using occurrence heuristic tables. Two words are considered related if they have the same morphological or lexical basis. The heuristic reports an approximate match if common letters agree in order and noncommon letters represent valid affixes. The heuristic was tested by using four different alignment strategies: forward, backward, combined forward–backward, and combined backward– forward. Using the error rate and missing rate as performance indicators, the approach was successful in providing more than 80% correct matches. Within the conditions of the experiments performed, the results indicated that the combined forward–backward strategy seemed to exhibit the best performance. Most of the errors were caused by multiple‐letter occurrences and by the presence of weak letters in cases in which the shared core consisted of one or two letters.
Failure of enoxaparin during coronary stenting: A case report
Authors: Chisholm Robert J. , Cantor Warren
Published: September 2005

A 90‐year‐old male underwent coronary stenting following a bout of coronary insufficiency. Coronary stenting was performed 6 hr following the last dose of low‐molecular‐weight heparin but was complicated by extensive intrastent clot formation. Low‐molecular‐weight heparin in the absence of a glycoprotein IIb/IIIa receptor blocker may be insufficient during percutaneous coronary intervention. © 2005 Wiley‐Liss, Inc.
Electrochemical Deposition of Ni(OH)2 and Fe‐Doped Ni(OH)2 Tubes
Authors: Chou Shulei , Cheng Fangyi , Chen Jun
Published: September 2005

Arrays of Ni(OH)2 and Fe‐doped Ni(OH)2 tubes were successfully prepared by electrochemical deposition in porous alumina membranes under ambient conditions. Extensive analysis of the tubes was carried out by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high‐resolution transmission electron microscopy (HRTEM) equipped with energy dispersive spectroscopy (EDS), and X‐ray photoelectron spectroscopy (XPS). The results show that the electrodeposition method yielded uniform Ni(OH)2 and Fe‐doped Ni(OH)2 tubes with inner diameters of 150–180 nm, wall thicknesses of 20–30 nm, and lengths of about 60 μm. This template‐based electrochemical deposition method can be extended to the synthesis of other similar materials such as micro‐ or nanotubes, ‐wires, and ‐rods. Furthermore, the Ni(OH)2 and Fe‐doped Ni(OH)2 tubes may have promising applications in alkaline rechargeable batteries and electrocatalytic electrolysis for the production of hydrogen. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Aerosol‐Assisted Chemical Vapor Deposition of NbS2 and TaS2 Thin Films from Pentakis(dimethylamido)metal Complexes and 2‐Methylpropanethiol
Authors: Peters Emily S. , Carmalt Claire J. , Parkin Ivan P. , Tocher Derek A.
Published: September 2005

Thin films of NbS2 and TaS2 have been produced from [M(NMe2)5] (M = Nb, Ta) and tBuSH by aerosol‐assisted chemical vapor deposition on glass. Gold‐colored, reflective films were obtained and deposition took place at 250–350 °C for NbS2 and 225–450 °C for TaS2 using dichloromethane or hexanes as solvent. The niobium and tantalum sulfide films were analyzed by Raman spectroscopy, scanning electron microscopy (SEM), X‐ray powder diffraction, energy dispersive analysis of X‐rays (EDAX) and X‐ray photoelectron spectroscopy (XPS). In order to identify possible compounds present in the aerosol mist, the solution phase reaction of [M(NMe2)5] and five equivalents of tBuSH in toluene at room temperature was carried out. Yellow crystals of the partially substituted tantalum thiolate [Ta(S‐tBu)2(NMe2)3] were isolated. The X‐ray structure of [Ta(S‐tBu)2(NMe2)3] has been determined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Direct Syntheses and Structural Novelty of Lanthanoid Aryloxides with Flexible Radial Arms
Authors: Cole Marcus L. , Deacon Glen B. , Junk Peter C. , Proctor Kathryn M. , Scott Janet L. , Strauss Christopher R.
Published: September 2005

Direct treatment of excess lanthanum, europium or ytterbium metal with 2,6‐dibenzylphenol (HOdbp) at 150 °C afforded [La2(Odbp)6], [Eu2(Odbp)4] and [Yb(Odbp)2]n, respectively, in high yields. Alternatively, treatment of Yb metal with excess HOdbp gave an ytterbium(III) species [Yb2(Odbp)6], similar to the lanthanum analogue. X‐ray crystal structures were obtained for [La2(Odbp)6], [Eu2(Odbp)4] and [Yb2(Odbp)6]. [La2(Odbp)6] and [Yb2(Odbp)6] are pseudo‐centrosymmetric dimers with two terminal and four bridging Odbp– ligands and [Eu2(Odbp)4] crystallizes as a centrosymmetric dimer with further organization in a polymeric form through supramolecular interactions. All three structurally characterized compounds achieve coordination saturation by Ln–π‐arene interactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Anthropogenic influences on Zuni agricultural soils
Authors: Homburg Jeffrey A. , Sandor Jonathan A. , Norton Jay B.
Published: September 2005

Farmers in the Zuni area of the semiarid American Southwest have successfully cultivated maize and other crops for over three millennia without using artificial fertilizers. Zuni agricultural fields are among the oldest, more or less continuously cultivated areas in the United States. Traditional Zuni agriculture is based on runoff farming, a system whereby runoff and organic‐rich sediment generated in small watersheds are captured and directed onto fields for crop use. We conducted a study to compare soil properties associated with paired and unpaired cultivated, abandoned, and uncultivated fields to evaluate the long‐term effects of cultivation on soil quality. Sampling and analytical methods of this research are especially applicable to geoarchaeological studies of anthropogenic effects on soil fertility and agricultural sustainability in ancient and traditional historical farming systems. Results of the Zuni soil study indicate that cultivation has altered some soil properties, including bulk density, organic carbon, total nitrogen, and C:N ratios in paired fields, but there is no indication that agricultural soils are degraded. This assessment supports the perception of Zuni farmers that long‐term cultivation has not caused a decline in agricultural productivity. © 2005 Wiley Periodicals, Inc.
Experimental hearths and the thermal alteration of Caliche on the Southern High Plains
Authors: Backhouse Paul N. , Johnson Eileen , Brackenreed‐Johnston Alexander , Buchanan Briggs
Published: September 2005

Throughout the Holocene, caliche has been a ubiquitous technological resource for the people of the Southern High Plains. Archaeological sites on the Southern High Plains often contain thermal features that appear to utilize caliche nodules in various cultural processes. These processes usually involve some degree of thermal dynamic alteration to the caliche, identified in the archaeological record as fire‐scorched or blackened nodules. Previous studies of the pyrodynamic properties of caliche have focused on quantification of color and fracture patterns within a laboratory setting, without direct involvement of cultural processes or problems associated with thermal features. Thermal alteration variables of caliche are examined from an actualistic perspective, utilizing previously excavated basin feature geometry and local caliche outcrops. Results indicate that sustained, intense heating of caliche (above 204°C) causes significant, but variable, structural transformations at the specimen level. The experimental use of shallow basin hearths demonstrates that hearth structures were easily capable of achieving and sustaining temperatures that would result in the physical alteration of individual caliche nodules, defined here as hearthstones. The broader implications of this study suggest that the interpretation of archaeological hearthstone assemblages should reflect variability, as observed during this experiment. © 2005 Wiley Periodicals, Inc.
Late Chiribaya agriculture and risk management along the arid Andean coast of southern Perú, A.D. 1200–1400
Authors: Zaro Gregory , Alvarez Adán Umire
Published: September 2005

Recent investigations at the coastal spring site of Wawakiki in southern Perú have identified an intensive, late pre‐Hispanic agricultural production strategy along a sea cliff some 30 km north of the Ilo River. Excavations identified buried stone‐faced agricultural terraces underlying Spanish colonial and post‐colonial furrows, and long irrigation canals that transported water along steep hill slopes from inland springs. Depositional patterns, cultural debris, and calibrated radiocarbon age ranges suggest the site was farmed most intensively between A.D. 1200 and 1400, a period characterized by prolonged highland drought and recurrent El Niño–induced floods in southern Perú. Farmers transformed this arid coastal promontory into a productive agricultural landscape by exploiting multiple spring sources, steep canals, and stone‐faced terraces in an area where water is a very limited commodity and steep barren hills are highly prone to erosion. Furthermore, high‐relief terrain left much of the agricultural infrastructure well protected from periodic floods. © 2005 Wiley Periodicals, Inc.
Galectin‐3 expression in papillary thyroid carcinoma: Relation to histomorphologic growth pattern, lymph node metastasis, extrathyroid invasion, and tumor size
Authors: Cvejic Dubravka S. , Savin Svetlana B. , Petrovic Ivana M. , Paunovic Ivan R. , Tatic Svetislav B. , Havelka Marija J.
Published: September 2005

Background.

Galectin‐3 has been recently recognized as a promising presurgical marker of thyroid malignancy.

Methods.

Galectin‐3 expression was examined immunohistochemically in 202 specimens of papillary thyroid carcinoma (PTC) in relation to histomorphologic subtypes and clinicopathologic data.

Results.

The sensitivity of galectin‐3 immunostaining versus conventional histology was 98% (100 of 102) for classical PTC, 85.2% (46 of 54) for follicular variant, and 50% (23 of 46) for follicular/solid variant of PTC. All cases (n = 36) involving lymph node metastases and 42 of 45 cases with extrathyroid invasion expressed galectin‐3. However, among the galectin‐3–positive cases (n = 169), 133 were without lymph node metastases, and 127 were without extrathyroid invasion. Galectin‐3 expression was not related to the size of intrathyroid PTC.

Conclusions.

Galectin‐3 immunohistochemical expression itself is not an indicator of local metastatic spread or extrathyroid invasion of PTC, thus being irrelevant clinically from this aspect. Galectin‐3 is an excellent marker for classical PTC but must be used with caution in diagnosing unconventional variants of PTC because of the possibility of false‐negative results. © 2005 Wiley Periodicals, Inc. Head Neck 27: XXX–XXX, 2005
Signaling pathways implicated in α‐melanocyte stimulating hormone‐induced lipolysis in 3T3‐L1 adipocytes
Authors: Cho Kyung‐Joo , Shim Jung‐Hyun , Cho Min‐Chul , Choe Yong‐Kyung , Hong Jin‐Tae , Moon Dong‐Chul , Kim Jong‐Wan , Yoon Do‐Young
Published: September 2005

Melanocortins, besides their central roles, have also recently been reported to regulate adipocyte metabolism. In this study, we attempted to characterize the mechanism underlying α‐melanocyte‐stimulating hormone (MSH)‐induced lipolysis, and compared it with that of the adrenocorticotrophin hormone (ACTH) in 3T3‐L1 adipocytes. Similar to ACTH, MSH treatment resulted in the release of glycerol into the cell supernatant. The activity of hormone‐sensitive lipase, a rate‐limiting enzyme, which is involved in lipolysis, was significantly increased by MSH treatment. In addition, a variety of kinases, including protein kinase A (PKA) and extracellular signal‐regulated kinase (ERK) were also phosphorylated as the result of MSH treatment, and their specific inhibitors caused a reduction in MSH‐induced glycerol release and HSL activity, indicating that MSH‐induced lipolysis was mediated by these kinases. These results suggest that PKA and ERK constitute the principal signaling pathways implicated in the MSH‐induced lipolytic process via the regulation of HSL in 3T3‐L1 adipocytes. J. Cell. Biochem. © 2005 Wiley‐Liss, Inc.
A density functional study of propylene glycol conversion to propanal and propanone of various acid‐catalyzed reaction models: A water‐addition effect
Authors: Rungnim Chompoonut , Ruangpornvisuti Vithaya
Published: September 2005

The acid‐catalyzed models on reaction mechanisms of pinacol rearrangement of propylene glycol conversion to propanal and propanone have been investigated using the density functional method at 298.15 K. Thermodynamic quantities of activation steps of four water‐addition models were obtained. The number of added water interacting with the transition states of three concerted pathways has obviously affected the product ratio. The relative energetic profiles of the conversion reactions of all solvation models have been comparatively displayed. Estimation of the percent ratio of product composition computed from activation free energies of each acid‐catalyzed reaction model was carried out. The percent ratios of propanal and propanone were decreased as the number of added water increased. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1592–1599, 2005
Effect of the axial cysteine ligand on the electronic structure and reactivity of high‐valent iron(IV) oxo‐porphyrins (Compound I): A theoretical study
Authors: Choe Yoong‐Kee , Nagase Shigeru
Published: September 2005

The effect of axial ligands on the reactivity of high‐valent iron(IV) oxo‐porphyrins (Compound I) was investigated using the B3LYP hybrid density functional method. We studied alkane hydroxylation using four models: Compound I with thiolate, imidazole, phenolate, and chloride anions as axial ligands. The first three ligands were employed as models for cysteinate, histidine, and tyrosinate, respectively. Our calculations show that anionic ligands and neutral ligands favor different electronic states for stationary points in the reaction coordinate, and the calculated energy barrier and energy of several reaction intermediates show similar values. A remarkable effect of axial ligands was found in the final product release step. Our calculations show that the thiolate ligand weakens a bond between heme and an alcohol. In contrast, the imidazole ligand significantly increases the interaction between heme and an alcohol, which causes the catalytic cycle to be less efficient. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1600–1611, 2005
Elevated expression of hypoxia inducible factor‐2α in terminally differentiating growth plate chondrocytes
Authors: Stewart Alan J. , Houston Brian , Farquharson Colin
Published: September 2005

Growth plate chondrocytes exist in a hypoxic environment where it is recognized that hypoxia‐inducible factor‐1α (HIF‐1α) is essential for their survival. Its regulation of chondrocyte viability may be mediated by the increased expression of vascular endothelial growth factor (VEGF) and glycolytic enzymes. However, the full chondrocyte response to hypoxia and the molecular control of VEGF expression in relation to growth plate differentiation and vascularization remains poorly understood. Using Percoll density gradient centrifugation, chick chondrocytes were separated into populations of different maturational phenotype. A differential display analysis of the populations showed highly upregulated expression of HIF‐2α mRNA during chondrocyte differentiation. HIF‐2α is a homologue of the HIF‐1α transcription factor, both of which play a role in the activation of a number of hypoxia responsive genes. HIF‐1α mRNA was also found to be expressed, although levels of expression were found to be similar in all of the chondrocyte fractions. The elevated expression of HIF‐2α during chondrocyte differentiation was accompanied by increased VEGF expression. Analysis of the murine chondrocyte cell line, ATDC5, which undergoes ordered maturation indicated that HIF‐2α, VEGF, placental growth factor, and glucose transporter‐1 expression all increased in parallel with chondrocyte differentiation. This observation was supported by immunohistochemistry on sections of mouse bone which showed staining corresponding to the presence of HIF‐2α in hypertrophic growth plate chondrocytes. The presence of HIF‐2α was also observed in articular chondrocytes but was restricted to the superficial tangential zone. HIF‐2α is, therefore, likely to be involved in the initiation of blood vessel formation and a metabolic shift in the growth plate, processes crucial for endochondral ossification. J. Cell. Physiol. 206: 435–440, 2006. © 2005 Wiley‐Liss, Inc.
Single cell analysis of PKC activation during proliferation and apoptosis induced by laser irradiation
Authors: Gao Xuejuan , Chen Tongsheng , Xing Da , Wang Fang , Pei Yihui , Wei Xunbin
Published: September 2005

Laser irradiation has been shown to trigger cellular proliferation and apoptosis in various cell types. Studying the signaling pathways involved in the laser irradiation is important for understanding these processes. In present study, to monitor the protein kinase Cs (PKCs) activity in living cells in real time, we transfected and screened human lung adenocarcinoma cells (ASTC‐a‐1) stably expressing C kinase activity reporter (CKAR) constructed based on fluorescence resonance energy transfer (FRET) technique. The CKAR is a specific, reversible reporter of phosphorylation by PKCs and it can monitor the ongoing balance between PKCs and phosphatases. The increasing dynamics of PKCs activity is monitored during cell proliferation induced by low‐power laser irradiation (LPLI) (0.8 J/cm2) in serum‐starved ASTC‐a‐1 cells stably expressing CKAR reporter using FRET imaging on laser scanning confocal microscope and using spectrofluorometric analysis on a luminescence spectrometer, respectively. However, the decreasing dynamics of PKCs activity has been monitored in real time using FRET imaging for the cells treated with high fluence LPLI (60 J/cm2), which was previously found to induce cell apoptosis. Taken together, LPLI induces the ASTC‐a‐1 cell proliferation by specifically activating PKCs. However, PKCs activity decreases during cell apoptosis induced by high fluence LPLI. Our results indicate that PKCs play an important role in the laser irradiation‐induced biological effects. J. Cell. Physiol. 206: 441–448, 2006. © 2005 Wiley‐Liss, Inc.
Maitotoxin potently promotes Ca2+ influx in mouse spermatogenic cells and sperm, and induces the acrosome reaction
Authors: Treviño Claudia L. , De la Vega‐Beltrán José L. , Nishigaki Takuya , Felix Ricardo , Darszon Alberto
Published: September 2005

Maitotoxin (MTX), a potent marine toxin, activates Ca2+ entry via nonselective cation channels in a wide variety of cells. The identity of the channels involved in MTX action remains unknown. In mammalian sperm, Ca2+ entry through store‐operated channels regulates a number of physiological events including the acrosome reaction (AR). Here we report that MTX produced an increase in the intracellular concentration of Ca2+ ([Ca2+]i) in spermatogenic cells that depended on extracellular Ca2+. Ni2+ and SKF96365 diminished the MTX‐activated Ca2+ uptake, at concentrations they inhibit store‐operated channels, and in a similar manner as they inhibit the Ca2+ influx activated following depletion of intracellular stores by thapsigargin (Tpg). In addition, MTX significantly increased [Ca2+]i in single mature sperm and effectively induced the AR with a half‐maximal concentration (ED50) of ∼1.1 nM. Notably, SKF96365 similarly inhibited the MTX‐induced increase in sperm [Ca2+]i and the AR triggered by the toxin, Tpg and zona pellucida. These results suggest that putative MTX‐activated channels may be involved in the Ca2+ influx required for mouse sperm AR. J. Cell. Physiol. 206: 449–456, 2006. © 2005 Wiley‐Liss, Inc.
Rate of oxygen consumption by isolated articular chondrocytes is sensitive to medium glucose concentration
Authors: Heywood Hannah K. , Bader Dan L. , Lee David A.
Published: September 2005

Cartilage tissue engineering typically involves the culture of isolated chondrocytes within a scaffold material. The oxygen tension within the engineered tissue is known to be an essential parameter for implant success. This will be sensitive to the oxygen consumption behavior of the embedded chondrocytes, which remains to be characterized. We report that the oxygen consumption of bovine articular chondrocytes is sensitive to glucose deprivation below 2.7 mM, increasing from a basal level of 9.6 × 10−16 to <18.4 × 10−16 mol/cell · h in 1.3 mM glucose. Further studies examined the influence of selecting high (18.4 mM) or low (5.1 mM) glucose medium on the oxygen tension in 2 mm thick cellular agarose constructs. A relative upregulation of oxygen consumption was observed in constructs cultured in low glucose medium. This resulted in the near‐anoxic oxygen concentration of 5 µM oxygen in constructs seeded with 40 × 106 cells/ml, compared to 57 µM in the corresponding high glucose culture. The upregulation of oxygen consumption generally corresponded to the inhibition of glycolysis, which is consistent with the Crabtree phenomenon. Medium osmolarity (316–600 mOsm) had minimal effects on chondrocyte oxygen consumption rate. In conclusion, glucose availability is a critical parameter that regulates the oxygen tension within tissue engineered constructs. J. Cell. Physiol. 206: 402–410, 2006. © 2005 Wiley‐Liss, Inc.
Cartducin, a paralog of Acrp30/adiponectin, is induced during chondrogenic differentiation and promotes proliferation of chondrogenic precursors and chondrocytes
Authors: Maeda Takashi , Jikko Akitoshi , Abe Makoto , Yokohama‐Tamaki Tamaki , Akiyama Hironori , Furukawa Souhei , Takigawa Masaharu , Wakisaka Satoshi
Published: September 2005

We previously reported that CORS26 gene, isolated from C3H10T1/2 cells treated with transforming growth factor‐β1, was predominantly expressed in cartilage. Because the gene product is a kind of secretory protein produced by cartilage tissue, we named it “cartducin”. Cartducin shares a similar modular organization to adipocyte‐derived hormone, adiponectin. In this study, we investigated cartducin function during chondrogenesis and cartilage development. In situ hybridization analysis showed that cartducin transcripts were restricted to the proliferating chondrocytes in the growth plate cartilage. Whole‐mount in situ hybridization revealed that the first significant induction of cartducin expression occurred in the sclerotome, which contains a chondrogenic cell lineage between days 9.5 and 10.5 postcoitus (p.c.) during mouse embryogenesis. Chondrogenic differentiation by combined treatment with bone morphogenetic protein‐2 and insulin induced cartducin expression along with type II and IX collagen expression in chondrogenic progenitor N1511 cells. To elucidate the direct action of cartducin on the cells, recombinant cartducin protein was expressed in and purified from Escherichia coli. The recombinant cartducin potentially forms homo‐oligomers and promoted the proliferation of chondrogenic progenitor N1511 cells, and chondrocytic HCS‐2/8 cells in a dose‐dependent manner. On the other hand, cartducin did not affect the production of sulfated glycosaminoglycan (sGAG) in these cells. These findings indicate that cartducin is a novel growth factor and plays important roles in regulating both chondrogenesis and cartilage development by its direct stimulatory action on the proliferation of chondrogenic precursors and chondrocytes. J. Cell. Physiol. 206: 537–544, 2006. © 2005 Wiley‐Liss, Inc.
Age affects ERK1/2 and NRF2 signaling in the regulation of GCLC expression
Authors: Li Muyao , Liu Rui‐Ming , Timblin Cynthia R. , Meyer Suzanne G. , Mossman Brooke T. , Fukagawa Naomi K.
Published: September 2005

We previously reported that activator protein‐1 (AP‐1) DNA binding activity was increased in vascular smooth muscle cells (VSMC) from old rats when exposed to high glucose or tumor necrosis factor (TNF‐α) (Li et al., 2003. J Cell Physiol 197:418–425). We have now examined the relationship between the age‐dependent activation of the ERK1/2–AP‐1 pathway and modulation of constitutive gene expression of the catalytic subunit of glutamate‐cysteine ligase (GCLC) in response to high glucose and TNF‐α. GCLC mRNA levels were higher in VSMC from old rats compared to young, a pattern consistent with its protein levels. To determine whether age‐related activation of ERK1/2‐AP‐1 signaling is responsible for the up‐regulation of GCLC, the MEK inhibitors, PD98059 and U0126, were used to block ERK1/2 in VSMC from old rats. An increase in GCLC with inhibitors was observed, diminishing the likelihood of ERK1/2‐AP‐1 activation as the up‐regulating signal for GCLC. However, the transcription factor Nrf2 was higher in nuclei and accompanied by increased Nrf2‐ARE binding in VSMC from old rats. Furthermore, MEK inhibitors increased nuclear Nrf2 and Nrf2/ARE binding. These data suggest opposing effects of Nrf2 and ERK1/2 signaling in the modulation of GCLC expression in old animals. J. Cell. Physiol. 206: 518–525, 2006. © 2005 Wiley‐Liss, Inc.
Automatic tuning of flexible interventional RF receiver coils
Authors: Venook Ross D. , Hargreaves Brian A. , Gold Garry E. , Conolly Steven M. , Scott Greig C.
Published: September 2005

Microcontroller‐based circuitry was built and tested for automatically tuning flexible RF receiver coils at the touch of a button. This circuitry is robust to 10% changes in probe center frequency, is in line with the scanner, and requires less than 1 s to tune a simple probe. Images were acquired using this circuitry with a varactor‐tunable 1‐inch flexible probe in a phantom and in an in vitro porcine knee model. The phantom experiments support the use of automatic tuning by demonstrating 30% signal‐to‐noise ratio (SNR) losses for 5% changes in coil center frequency, in agreement with theoretical calculations. Comparisons between patellofemoral cartilage images obtained using a 3‐inch surface coil and the surgically‐implanted 1‐inch flexible coil reveal a worst‐case local SNR advantage of a factor of 4 for the smaller coil. This work confirms that surgically implanted coils can greatly improve resolution in small‐field‐of‐view (FOV) applications, and demonstrates the importance and feasibility of automatically tuning such probes. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Iterative RF pulse design for multidimensional, small‐tip‐angle selective excitation
Authors: Yip Chun‐yu , Fessler Jeffrey A. , Noll Douglas C.
Published: September 2005

The excitation k‐space perspective on small‐tip‐angle selective excitation has facilitated RF pulse designs in a range of MR applications. In this paper, k‐space‐based design of multidimensional RF pulses is formulated as a quadratic optimization problem, and solved efficiently by the iterative conjugate‐gradient (CG) algorithm. Compared to conventional design approaches, such as the conjugate‐phase (CP) method, the new design approach is beneficial in several regards. It generally produces more accurate excitation patterns. The improvement is particularly significant when k‐space is undersampled, and it can potentially shorten pulse lengths. A prominent improvement in accuracy is also observed when large off‐resonance gradients are present. A further boost in excitation accuracy can be accomplished in regions of interest (ROIs) if they are specified together with “don't‐care” regions. The density compensation function (DCF) is no longer required. In addition, regularization techniques allow control over integrated and peak pulse power. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Ghost artifact removal using a parallel imaging approach
Authors: Winkelmann Richard , Börnert Peter , Dössel Olaf
Published: September 2005

Parallel imaging techniques, which use several receive coils simultaneously, have been shown to enable a significant scan time reduction by subsampling k‐space. Nevertheless, the data acquired with multiple coils in parallel exhibit some redundancy if the number of receive coils exceeds the subsampling factor. This redundancy leads to an overdetermination of the reconstruction problem, which is generally used to optimize the signal‐to‐noise ratio (SNR). However, it can yield further information about the quality of the reconstructed image, and can thus be used to identify and correct image artifacts. While some known approaches try to solve this problem in k‐space, this study addresses it in the spatial domain and uses a modified SENSE reconstruction to reduce or completely remove ghost‐type artifacts arising from processes such as motion or flow during data acquisition. Phantom and in vivo studies show significant improvements in image quality after correction, and serve as a basis for the discussion of the performance and limitations of this new approach. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Simultaneous multislice imaging with slice‐multiplexed RF pulses
Authors: Lee K.J. , Wild J.M. , Griffiths P.D. , Paley M.N.J.
Published: September 2005

A method for simultaneous multislice imaging is presented that uses a multislice RF pulse that imparts a different linear phase profile to each slice. During readout, slices are unaliased by using extra slice‐select gradient lobes, which rephase and dephase individual slices one at a time. Compared to other simultaneous slice methods, this method avoids distortion by slice‐select gradients, and does not require extra views or additional hardware. However, because one echo per slice is required, the method requires a longer read period. This can cause non‐ideal rephasing of the individual slices due to susceptibility gradients, which manifests itself as crosstalk between slices. There is also a concomitant increase in the minimum TR of the sequence. The method is demonstrated with phantom and in vivo images using gradient‐echo and spin‐echo versions. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Experimental analysis of parallel excitation using dedicated coil setups and simultaneous RF transmission on multiple channels
Authors: Ullmann Peter , Junge Sven , Wick Markus , Seifert Frank , Ruhm Wolfgang , Hennig Jürgen
Published: September 2005

An experimental implementation and first performance analysis of parallel spatially selective excitation with an array of transmit coils and simultaneous transmission of individual waveforms on multiple channels is presented. This technique, also known as Transmit SENSE, uses the basic idea of parallel imaging to shorten the k‐space trajectories that accompany multidimensional excitation pulses, and hence shorten the duration of such pulses. So far, this concept has only been presented in simulations and semi‐experimental studies since no hardware setup had been available for a full experimental realization. In this study, a hardware solution, in combination with a dedicated coil setup, is presented to overcome this limitation, and in several experiments of localized excitation and transmit field inhomogeneity compensation the practical feasibility of Transmit SENSE is demonstrated and a first performance analysis is given. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Indicative oligodendrocyte dysfunction in spinal cords of human fetuses suffering from a lethal motoneuron disease
Authors: Pakkasjärvi Niklas , Gentile Massimiliano , Saharinen Juha , Honkanen Jarno , Herva Riitta , Peltonen Leena , Kestilä Marjo
Published: September 2005

Human spinal cord development is still poorly understood and detailed molecular analyses of human motoneuron diseases could improve our understanding of the normal developmental processes of the spinal cord. Lethal Congenital Contracture Syndrome (LCCS, MIM 253310) provides a human model to study the early motoneuronal development. A typical phenotype of LCCS fetuses consists of multiple joint contractures, distinct facial features, and hydrops. Tissue pathology is characterized by severe muscle atrophy, lung hypoplasia, and degeneration of the anterior horn of the spinal cord as the hallmark of the syndrome. In this study we performed a global transcript analysis of LCCS spinal cords. The RNA expression profiles of these spinal cords were compared to age‐matched healthy control fetuses, aborted for nonrelated causes. In addition, we applied phylogenetic footprinting methods to decipher the mechanisms of transcriptional regulation in the affected transcripts. Changes in transcripts involved with the development of the CNS and oligodendrocytes were obvious and the transcription factor PAX6 was identified as a key regulator during spinal cord development. In addition, transcript pathway analysis clearly indicated genes belonging to groups with neuronal functions to be affected. Our findings support the hypothesis that human motoneurons and oligodendrocytes are dependent on each other during their development and are influenced by distinct transcription factors previously known to act during murine and chick motoneuron development. These data provide valuable information about the molecular pathways putatively active in motoneuron diseases. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005
Isolation and culture of hair cell progenitors from postnatal rat cochleae
Authors: Zhai Suoqiang , Shi Li , Wang Bu‐er , Zheng Guiliang , Song Wei , Hu Yinyan , Gao Wei‐Qiang
Published: September 2005

Cochlear hair cells are a terminally differentiated cell population that is crucial for hearing. Although recent work suggests that there are hair cell progenitors in postnatal mammalian cochleae, isolation and culture of pure hair cell progenitors from a well‐defined cochlear area have not been reported. Here we present an experimental method that allows isolation and culture of hair cell progenitors from postnatal rat cochleae. These progenitor cells are isolated from the lesser epithelial ridge (LER, or outer spiral sulcus cell) area of pre‐plated neonatal rat cochlear segments. They express the same markers as LER cells in vivo, including ZO1, Islet1, Hes1, and Hes5. When these cells are induced to express Hath1, they show the potential to differentiate into hair cell‐like cells. Interestingly, these cells can be lifted from monolayer cultures and maintained in aggregate cultures in which spheres can be formed. Hair cell progenitors in the spheres display their proliferating capability and express only epithelial markers. Furthermore, when these spheres are mixed with dissociated mesenchymal cells prepared from postnatal rat utricular whole mounts, and replated onto a collagen substratum, the epithelial progenitor cells are able to differentiate into cells expressing markers of hair cells and supporting cells in epithelial islands, which mirrors the inner ear sensory epithelium in vivo. Successful isolation and culture of hair cell progenitors from the mammalian cochlea will facilitate studies on gene expression profiling and mechanism of differentiation/regeneration of hair cells, which are crucial for repairing hearing loss. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005
Extramedullary plasmacytoma of the adenoids
Authors: Mann Georg , Trebo Monika M. , Minkov Milen , Simonitsch Ingrid , Chott Andreas , Gadner Helmut
Published: September 2005

Extramedullary plasmacytomas are extremely rarely diagnosed in children. We report two cases of extramedullary plasmacytoma detected coincidentally in the adenectomy specimens of children younger than 4 years. We show that these children are disease‐free after local excision as the only treatment. Surgical treatment without anti‐neoplastic therapy in pediatric plasma cell dyscrasias of the pharyngeal lymphoid tissue may be a sufficient curative therapy. Pediatr Blood Cancer 2007;48:361–362. © 2005 Wiley‐Liss, Inc.
Primary renal lymphoma presenting with hypertension
Authors: Becker Amy M. , Bowers Daniel C. , Margraf Linda R. , Emmons Jacqueline , Baum Michel
Published: September 2005

Primary renal lymphoma (PRL) is a rare lymphoma which usually presents with hematuria, flank pain, abdominal mass, and weight loss. PRL is more diagnosed in adults than children. We describe an asymptomatic child who presented with hypertension and was subsequently diagnosed with primary renal lymphoma. This case represents an atypical presentation for PRL. Pediatr Blood Cancer 2007;48:711–713. © 2005 Wiley‐Liss, Inc.
Outcome of hematopoietic stem cell transplantation for pediatric patients with therapy‐related acute myeloid leukemia or myelodysplastic syndrome
Authors: Woodard Paul , Barfield Raymond , Hale Gregory , Horwitz Edwin , Leung Wing , Ribeiro Raul , Rubnitz Jeffrey , Srivistava Deo Kumar , Tong Xin , Yusuf Usman , Raimondi Susana , Pui Ching‐Hon , Handgretinger Rupert , Cunningham John M.
Published: September 2005

Background

Therapy‐related myelodysplastic syndrome (t‐MDS) and acute myeloid leukemia (t‐AML) carry a poor prognosis. We analyzed the results of allogeneic HSCT in 38 children to determine which factors, if any, affected outcome.

Procedure

The effects of demographic, donor, and disease‐related factors were analyzed to determine their effects on overall and disease‐free survival (OS, DFS), relapse, and non‐relapse mortality (NRM).

Results

OS and DFS for t‐AML and t‐MDS were similar. Three‐year OS and EFS were the same (15.4 ± 5.8%) and the 3‐year NRM was 59.6 ± 8.4%. The 1‐year cumulative risk of grade III–IV acute graft‐versus‐host disease (GVHD) and relapse were 23.7 ± 7.0% and 18.7 ± 6.5%, respectively. The percentage of pre‐transplant bone marrow (BM) blasts was positively associated with relapse (P = 0.05), while the percentage of BM blasts at diagnosis of therapy‐related disease tended to associate with NRM (P = 0.07). Alternative donor and matched sibling donor grafts had similar outcomes. NRM was higher among patients who did not develop acute GVHD as compared to those with grade 1–2 acute GVHD (69.2 ± 14.2% vs. ± 12.7%, respectively), while NRM was 100% in patients with grade III–IV acute GVHD (P = 0.007).

Conclusions

The percentage of BM blasts is associated with relapse in these disorders. High rates of NRM negatively impact the outcome of allogeneic HSCT for children with t‐AML and t‐MDS. Future studies should focus on reducing NRM. © 2005 Wiley‐Liss, Inc.