bluuebunny/crossref_metadata_2025 huggingface dataset:
Common Carotid Artery Intima-Media Thickness and Intracranial Pulsatility Index in Non-ST-Elevation Acute Coronary Syndromes
Authors: Tello-Montoliu Antonio , Moltó José M. , López-Hernández Nicolás , García-Medina Ana , Roldán Vanessa , Sogorb Francisco , Lip Gregory Y.H. , Marín Francisco
Published: August 2007

Background: Common carotid intima-media thickness (CIMT) has been related to cardiovascular risk factors, coronary atherosclerosis and a higher risk of myocardial infarction. Evaluation of intracranial arteries by transcranial Doppler explores the presence of vascular dysfunction at this level. We tested the hypothesis that CIMT and Doppler Pulsatility Index (DPI) can be related to the Thrombolysis in Myocardial Infarction (TIMI) risk score for non-ST-elevation acute coronary syndrome (nST-ACS). The relation to the prognosis after an acute event was also assessed. Methods: We recruited 126 consecutive patients (80 males; mean age: 66.6 ± 13.1 years) admitted with nST-ACS. A carotid assessment with bidimensional mode, measuring the CIMT in the posterior wall of the common carotid artery, and a transcranial Doppler assessment of the middle cerebral artery, with measurement of the Pulsatility Index were carried out. Clinical follow-up at 6 months was performed for endpoints (cardiovascular death, recurrent ACS or revascularization). Results: Fifty-nine patients had an abnormal (≧0.8 mm) CIMT, whilst 70 patients had an abnormal DPI (≧1.2). CIMT was correlated with TIMI risk score (Pearson r: 0.26; p = 0.004), whilst abnormal DPI was associated with TIMI risk scale (p < 0.001). Using a logistic regression analysis, the presence of an abnormal CIMT was only related to age ≧65 (p = 0.0012) and diabetes mellitus (p = 0.0028). Abnormal DPI was also associated with age ≧65 (p < 0.0001) and diabetes mellitus (p = 0.0466). Neither CIMT nor DPI were related to 6 months’ clinical outcome. Conclusions: Patients with nST-ACS have a high prevalence of dates of abnormal DPI, which was associated with increased CIMT. Both variables were related to age and diabetes but not with clinical outcomes.
Long-Term Outcome as Function of Blood Pressure in Acute Ischemic Stroke and Effects of Thrombolysis
Authors: Yong Mei , Diener Hans-Christoph , Kaste Markku , Mau Jochen
Published: August 2007

Background: While baseline blood pressure (BP) is a known predictor of 90-day residual deficit after acute ischemic stroke, the effect of thrombolysis on this relationship has not been described. To study the interaction and to find intervals of prognostic significance, the functional forms of this predictive relationship should be found and compared for recombinant tissue plasminogen activator (rt-PA)- and placebo-treated patients of the first European Cooperative Acute Stroke Study. Methods: We studied the 615 patients with acute ischemic hemispheric stroke randomized and treated in the first European Cooperative Acute Stroke Study. Endpoints were fatal outcome within and favorable outcome (no or negligible long-term handicap on the modified Rankin Scale scores 0 or 1) after 90 ± 14 days. Functional relationships with baseline BP were estimated fully nonparametrically as moving averages of occurrences of either outcome among placebo- and rt-PA-treated patients, separately. Visual findings were corroborated by conventionally stratified logistic regression. Results: For favorable outcome, an S-shaped functional relationship with baseline systolic BP (SBP) was found with an averaged incremental rate around 10% per 1 mm Hg increase in baseline SBP between 140 and 160 mm Hg, among rt-PA and placebo patients. Similar results were obtained for diastolic BP (DBP) between 80 and 90 mm Hg. Odds ratios in favor of rt-PA were 1.96 (95% CI: 1.02–3.78) and 2.87 (95% CI: 1.36–6.04) for SBP and DBP in these intervals, respectively. For mortality, visible markedly lower risks in the placebo group between 120 and 140 and between 160 and 180 mm Hg SBP were confirmed with adjusted OR of 2.47 (95% CI: 1.09–5.64) and 9.73 (95% CI: 2.02–46.82), respectively. Conclusions: Patients benefited from rt-PA in terms of no or negligible handicap after 90 days, without excess risk of death, with baseline SBP between 140 and 160 mm Hg or baseline DBP between 80 and 90 mm Hg.
3-Tesla versus 1.5-Tesla Magnetic Resonance Diffusion and Perfusion Imaging in Hyperacute Ischemic Stroke
Authors: Kosior Robert K. , Wright Caitlin J. , Kosior Jayme C. , Kenney Carol , Scott James N. , Frayne Richard , Hill Michael D.
Published: August 2007

Background: Clinical 3-tesla magnetic resonance imaging systems are becoming widespread. No studies have examined differences between 1.5-tesla and 3-tesla imaging for the assessment of hyperacute ischemic stroke (<6 h from symptom onset). Our objective was to compare 1.5-tesla and 3-tesla diffusion and perfusion imaging for hyperacute stroke using optimized protocols. Methods: Three patients or their surrogate provided informed consent. Diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) was performed sequentially at 1.5 T and 3 T. DWI, apparent diffusion coefficient (ADC) maps and relative time-to-peak (TTP) maps were registered and assessed. DWI contrast-to-noise ratio (CNR) and ADC contrast were measured and compared. The infarct lesion volume (ILV) and thresholded ischemic volume (TIV) were estimated on the ADC and TTP maps, respectively, with the penumbral volume being defined as the difference between these volumes. Results: Qualitatively, the 3-tesla TTP images exhibited greater feature detail. Quantitatively, the DWI CNR and ILV were similar at both field strengths, the ADC contrast was greater at 3 T and the TIV and penumbral volumes were much smaller at 3 T. Conclusions: Overall, the 3-tesla diffusion and perfusion images were at least as good and in some ways superior to the 1.5-tesla images for assessing hyperacute stroke. The TTP maps showed greater feature detail at 3 T. The ischemic and penumbra volumes were much greater at 1.5 T, indicating a potential difference in the diagnostic utility of the PWI-DWI mismatch between field strengths.
Diagnostic Performance of Clock Drawing Test by CLOX in an Asian Chinese Population
Authors: Yap Philip Lin-Kiat , Ng Tze-Pin , Niti Mathew , Yeo Donald , Henderson Linda
Published: August 2007

Background/Aims: Clock Drawing Tests are commonly used for cognitive screening, but their clinical utility has not yet been studied in Chinese Singaporeans. We examined the usefulness of a Clock Drawing Test, CLOX, in detecting dementia in our population and explored its performance in the dementia subtypes, Alzheimer’s disease (AD), and the vascular composite group (VCG) of AD with cerebrovascular disease and vascular dementia. Method: CLOX was administered to 73 subjects (49.3%) with dementia and 75 healthy controls (50.7%). Receiver operating characteristic analysis determined the diagnostic accuracy and optimal cut-off scores, stratified by education. Analysis of Variance was used to compare CLOX scores between AD and VCG. Results: The diagnostic accuracy (area under the curve) was 84 and 85% for CLOX1 and CLOX2, respectively. Cut-offs at 10 for CLOX1 and 12 for CLOX2 yielded sensitivities of 75.3 and 75%, and specificities of 76 and 80%, respectively. The mean CLOX1 but not CLOX2 scores for AD (8.1) and VCG (5.5) remained significantly different (p = 0.002) after adjustment for the covariates age, gender, education, MMSE and dementia stage. Conclusion: Our results support CLOX as a valid cognitive screen in Singaporean Chinese with adequate psychometric properties. In addition, CLOX may aid as an adjunct in differentiating AD from dementia with a vascular element, e.g. AD with cerebrovascular disease and vascular dementia.
The Problem of Passenger Genes in Transgenic Mice
Authors: Lusis Aldons J. , Yu Janet , Wang Susanna S.
Published: August 2007

Gene targeted or transgenic mice are frequently created on one genetic background and the mutation then transferred to a second genetic background by a series of backcrosses, with selection for the mutation at each generation. This is the same experimental design as that used in the production of classical congenic strains in which a genomic region from a “donor” strain is transferred to the background of a “recipient” strain by backcrossing and selection for ten or more generations. While the strategy largely results in the replacement of the donor background with the recipient background, the region flanking the selected gene remains of donor origin. Thus, the genes in this flanking region are “passengers” that travel with the selected gene, and when comparing transgenic (or knockout) mice with non-transgenic littermates, allelic differences in the passenger genes can conceivably influence the traits of interest. It now appears that this passenger gene effect may be an important confounder in studies of cardiovascular and metabolic traits that are influenced by dozens of common variations present among inbred mouse strains. Here, we discuss the problem and some approaches to avoid it.
Sequential-Design, Multicenter, Randomized, Controlled Trial of Early Decompressive Craniectomy in Malignant Middle Cerebral Artery Infarction (DECIMAL Trial)
Authors: Vahedi Katayoun , Vicaut Eric , Mateo Joaquim , Kurtz Annie , Orabi Mikael , Guichard Jean-Pierre , Boutron Carole , Couvreur Gregory , Rouanet François , Touzé Emmanuel , Guillon Benoît , Carpentier Alexandre , Yelnik Alain , George Bernard , Payen Didier , Bousser Marie-Germaine
Published: August 2007

Background and Purpose—

There is no effective medical treatment of malignant middle cerebral artery (MCA) infarction. The purpose of this clinical trial was to assess the efficacy of early decompressive craniectomy in patients with malignant MCA infarction.

Methods—

We conducted in France a multicenter, randomized trial involving patients between 18 and 55 years of age with malignant MCA infarction to compare functional outcomes with or without decompressive craniectomy. A sequential, single-blind, triangular design was used to compare the rate of development of moderate disability (modified Rankin scale score ≤3) at 6 months’ follow-up (primary outcome) between the 2 treatment groups.

Results—

After randomization of 38 patients, the data safety monitoring committee recommended stopping the trial because of slow recruitment and organizing a pooled analysis of individual data from this trial and the 2 other ongoing European trials of decompressive craniectomy in malignant MCA infarction. Among the 38 patients randomized, the proportion of patients with a modified Rankin scale score ≤3 at the 6-month and 1-year follow-up was 25% and 50%, respectively, in the surgery group compared with 5.6% and 22.2%, respectively, in the no-surgery group (
P
=0.18 and
P
=0.10, respectively). There was a 52.8% absolute reduction of death after craniectomy compared with medical therapy only (
P
<0.0001).

Conclusions—

In this trial, early decompressive craniectomy increased by more than half the number of patients with moderate disability and very significantly reduced (by more than half) the mortality rate compared with that after medical therapy.
Decompressive Surgery for the Treatment of Malignant Infarction of the Middle Cerebral Artery (DESTINY)
Authors: Jüttler Eric , Schwab Stefan , Schmiedek Peter , Unterberg Andreas , Hennerici Michael , Woitzik Johannes , Witte Steffen , Jenetzky Ekkehart , Hacke Werner
Published: August 2007

Background and Purpose—

Decompressive surgery (hemicraniectomy) for life-threatening massive cerebral infarction represents a controversial issue in neurocritical care medicine. We report here the 30-day mortality and 6- and 12-month functional outcomes from the DESTINY trial.

Methods—

DESTINY (ISRCTN01258591) is a prospective, multicenter, randomized, controlled, clinical trial based on a sequential design that used mortality after 30 days as the first end point. When this end point was reached, patient enrollment was interrupted as per protocol until recalculation of the projected sample size was performed on the basis of the 6-month outcome (primary end point=modified Rankin Scale score, dichotomized to 0 to 3 versus 4 to 6). All analyses were based on intention to treat.

Results—

A statistically significant reduction in mortality was reached after 32 patients had been included: 15 of 17 (88%) patients randomized to hemicraniectomy versus 7 of 15 (47%) patients randomized to conservative therapy survived after 30 days (
P
=0.02). After 6 and 12 months, 47% of patients in the surgical arm versus 27% of patients in the conservative treatment arm had a modified Rankin Scale score of 0 to 3 (
P
=0.23).

Conclusions—

DESTINY showed that hemicraniectomy reduces mortality in large hemispheric stroke. With 32 patients included, the primary end point failed to demonstrate statistical superiority of hemicraniectomy, and the projected sample size was calculated to 188 patients. Despite this failure to meet the primary end point, the steering committee decided to terminate the trial in light of the results of the joint analysis of the 3 European hemicraniectomy trials.
Kupffer cell heterogeneity: functional properties of bone marrow–derived and sessile hepatic macrophages
Authors: Klein Ingo , Cornejo Judith C. , Polakos Noelle K. , John Beena , Wuensch Sherry A. , Topham David J. , Pierce Robert H. , Crispe Ian Nicholas
Published: August 2007

Kupffer cells form a large intravascular macrophage bed in the liver sinusoids. The differentiation history and diversity of Kupffer cells is disputed; some studies argue that they are derived from blood monocytes, whereas others support a local origin from intrahepatic precursor cells. In the present study, we used both flow cytometry and immunohistochemistry to distinguish 2 subsets of Kupffer cells that were revealed in the context both of bone marrow transplantation and of orthotopic liver transplantation. One subset was radiosensitive and rapidly replaced from hematogenous precursors, whereas the other was relatively radioresistant and long-lived. Both were phagocytic but only the former population was recruited into inflammatory foci in response to CD8+ T-cell activation. We propose the name “sessile” for the radioresistant Kupffer cells that do not participate in immunoinflammatory reactions. However, we found no evidence that these sessile Kupffer cells arise from immature intrahepatic precursors. Our conclusions resolve a long-standing controversy and explain how different experimental approaches may reveal one or both of these subsets.
TGF-beta receptor 2 downregulation in tumour-associated stroma worsens prognosis and high-grade tumours show more tumour-associated macrophages and lower TGF-beta1 expression in colon carcinoma: a retrospective study
Authors: Bacman David , Merkel Susanne , Croner Roland , Papadopoulos Thomas , Brueckl Wolfgang , Dimmler Arno
Published: August 2007

Background

Histological phenotype and clinical behaviour of malignant tumours are not only dependent on alterations in the epithelial cell compartment, but are affected by their interaction with inflammatory cells and tumour-associated stroma. Studies in animal models have shown influence of tumour-associated macrophages (TAM) on histological grade of differentiation in colon carcinoma. Disruption of transforming growth factor beta (TGF-beta) signalling in tumour cells is related to more aggressive clinical behaviour. Expression data of components of this pathway in tumour-associated stroma is limited.

Methods

Tissue micro arrays of 310 colon carcinomas from curatively resected patients in UICC stage II and III were established. In a first step we quantified amount of CD68 positive TAMs and expression of components of TGF-beta signalling (TGF-beta1, TGF-beta receptors type 1 and 2, Smad 3 and 4) in tumour and associated stroma. Further we analyzed correlation to histological and clinical parameters (histological grade of differentiation (low-grade (i.e. grade 1 and 2) vs. high-grade (i.e. grade 3 and 4)), lymph node metastasis, distant metastasis, 5 year cancer related survival) using Chi-square or Fisher's exact test, when appropriate, to compare frequencies, Kaplan-Meier method to calculate 5-year rates of distant metastases and cancer-related survival and log rank test to compare the rates of distant metastases and survival. To identify independent prognostic factors Cox regression analysis including lymph node status and grading was performed.

Results

High-grade tumours and those with lymph node metastases showed higher rates of TAMs and lower expression of TGF-beta1. Loss of nuclear Smad4 expression in tumor was associated with presence of lymph node metastasis, but no influence on prognosis could be demonstrated. Decrease of both TGF-beta receptors in tumour-associated stroma was associated with increased lymph node metastasis and shorter survival. Stromal TGF-beta receptor 2 expression was an independent prognostic factor for cancer related survival.

Conclusion

Histological phenotype and clinical behaviour of colon cancer is not only influenced by mutational incidents in tumour cells but also affected by interaction of tumour tissue with inflammatory cells like macrophages and associated stroma and TGF-beta signalling is one important part of this crosstalk. Further studies are needed to elucidate the exact mechanisms.
Positive end-expiratory pressure at minimal respiratory elastance represents the best compromise between mechanical stress and lung aeration in oleic acid induced lung injury
Authors: Carvalho Alysson Roncally S , Jandre Frederico C , Pino Alexandre V , Bozza Fernando A , Salluh Jorge , Rodrigues Rosana , Ascoli Fabio O , Giannella-Neto Antonio
Published: August 2007

Introduction

Protective ventilatory strategies have been applied to prevent ventilator-induced lung injury in patients with acute lung injury (ALI). However, adjustment of positive end-expiratory pressure (PEEP) to avoid alveolar de-recruitment and hyperinflation remains difficult. An alternative is to set the PEEP based on minimizing respiratory system elastance (Ers) by titrating PEEP. In the present study we evaluate the distribution of lung aeration (assessed using computed tomography scanning) and the behaviour of Ers in a porcine model of ALI, during a descending PEEP titration manoeuvre with a protective low tidal volume.

Methods

PEEP titration (from 26 to 0 cmH2O, with a tidal volume of 6 to 7 ml/kg) was performed, following a recruitment manoeuvre. At each PEEP, helical computed tomography scans of juxta-diaphragmatic parts of the lower lobes were obtained during end-expiratory and end-inspiratory pauses in six piglets with ALI induced by oleic acid. The distribution of the lung compartments (hyperinflated, normally aerated, poorly aerated and non-aerated areas) was determined and the Ers was estimated on a breath-by-breath basis from the equation of motion of the respiratory system using the least-squares method.

Results

Progressive reduction in PEEP from 26 cmH2O to the PEEP at which the minimum Ers was observed improved poorly aerated areas, with a proportional reduction in hyperinflated areas. Also, the distribution of normally aerated areas remained steady over this interval, with no changes in non-aerated areas. The PEEP at which minimal Ers occurred corresponded to the greatest amount of normally aerated areas, with lesser hyperinflated, and poorly and non-aerated areas. Levels of PEEP below that at which minimal Ers was observed increased poorly and non-aerated areas, with concomitant reductions in normally inflated and hyperinflated areas.

Conclusion

The PEEP at which minimal Ers occurred, obtained by descending PEEP titration with a protective low tidal volume, corresponded to the greatest amount of normally aerated areas, with lesser collapsed and hyperinflated areas. The institution of high levels of PEEP reduced poorly aerated areas but enlarged hyperinflated ones. Reduction in PEEP consistently enhanced poorly or non-aerated areas as well as tidal re-aeration. Hence, monitoring respiratory mechanics during a PEEP titration procedure may be a useful adjunct to optimize lung aeration.
Guest-Induced Assembly of PdII-Linked Coordination Nanotubes
Authors: Tominaga Masahide , Fujita Makoto
Published: August 2007

This article reviews a coordination approach to discrete tubular structures. Families of pyridine-based molecular strands assemble into large tubular molecules through metal-coordination. In particular, cis-protected square-planar metals, [enPdII]2+ (en = ethylenediamine), are very useful building blocks to link these molecules. Pyridine-based oligo(3,5-pyridine) ligands efficiently self-assemble into well-defined tube frameworks having a variety of shapes and sizes upon treatment with [enPd(NO3)2] in the presence of rod-like organic guests as templates. The length of the tube can be strictly controlled according to the numbers of pyridine nuclei involved in the component ligand. These nanotubes collapse when the template molecule is removed. A hexapyridine ligand, in which two tripyridine units are linked by an alkyl spacer, forms a complex with the PdII building block leading to the formation of a stable nanotube with an empty cavity without templates. With the aid of a 3.0 nm template strand molecule, a hexapyridine ligand consisting of two tripyridine units and a biphenyl linker assembles into a 3.5-nm nanotube, in which the four ligands are held together by twelve PdII ions. Facile preparation as well as the stability of the tube, even after the template is removed makes possible the hollow discrete assembly of the tubes. A dodecapyridine ligand possessing four tripyridine podands on a benzenetetracarboxylate scaffold, six PdII ions, and a template molecule generate a mono end-capped tube, which converts into a double open tube upon crystallization. Once formed, there is no route back to the end-capped tube. The structures are not in rapid equilibrium and are kinetically trapped during self-assembly. These tubular structures have been confirmed by NMR, CSI-MS observations, and X-ray crystallographic analysis. Studies on the dynamic behavior of rod-like guests accommodated in the nanotubes are also discussed.
Molecular Descriptors of Topology and a Study on Quantitative Structure and Property Relationships
Authors: Zhou Congyi , Nie Changming
Published: August 2007

The novel topological descriptor PE was proposed, using a revised distance matrix involving relative bond length as well as equilibrium electronegativity. Along with PE, the quantitative structure–property relationships were included with path number P3. The analyzed models could be applicable to the condensed-type properties of hydrocarbons. Moreover, the models also were applicable to the Kováts retention indexes under different conditions.
Importance of Molecular-Level Contacts under Solventless Conditions for Chemical Reactions and Self-Assembly
Authors: Orita Akihiro , Okano Junji , Uehara Genta , Jiang Lasheng , Otera Junzo
Published: August 2007

It has been shown that solventless reactions are accelerated when the reactants are mixed at molecular level. Accordingly, a solid film obtained by evaporating a solution of reactants mixture underwent facile reaction either upon grinding or upon simply standing. The effectiveness of these methods is evident from comparison with conventional solventless and solution reactions. It was concluded consequently that, once the molecular-level contacts are formed between reactants, the reaction occurs more efficiently under solventless conditions than in solution. Due to this pre-mixing method, efficient synthesis of [2]rotaxanes and rate acceleration of the Wittig reaction were achieved.
Integrated Strategy for Fast and Automated Molecular Characterization of Genes Involved in Craniosynostosis
Authors: Stenirri Stefania , Restagno Gabriella , Ferrero Giovanni Battista , Alaimo Georgia , Sbaiz Luca , Mari Caterina , Genitori Lorenzo , Maurizio Ferrari , Cremonesi Laura
Published: August 2007

Background: Craniosynostosis, the premature fusion of 1 or more sutures of the skull, is a common congenital defect, with a prevalence of 1 in 2500 live births. Untreated progressive craniosynostosis leads to inhibition of brain growth and increased intracranial and intraorbital pressure. The heterogeneity of clinical phenotypes and the overlap of the various associated syndromes render the correct diagnosis of the different craniosynostoses particularly difficult.

Methods: To identify 10 common mutations in the genes for fibroblast growth factor receptors 2 and 3 (FGFR2 and FGFR3), we developed a microelectronic microchip assay that exploited the PCR multiplexing format and coupled it with serial addressing and probe hybridization on the same pad. For the molecular characterization of patients who tested negative in the microchip screening, we also developed conditions for denaturing HPLC (DHPLC) analysis of the most mutated regions of FGFR2 and FGFR3 and the entire coding region of the TWIST1 gene.

Results: In our cohort of 159 patients with various craniosynostosis syndromes, mutations were found in 100% of patients with Apert syndrome, 83.3% with Pfeiffer syndrome, 72.7% with Crouzon syndrome, 50.0% with Saethre-Chotzen syndrome, 27.7% with plagiocephaly, 31.8% with brachicephaly, 20% of complex cases, and 6.9% of mixed cases. No mutations were found in syndromic cases.

Conclusions: The combined microchip-DHPLC strategy allows rapid and specific molecular diagnosis of craniosynostosis and is an effective tool for the medical and surgical management of these common congenital anomalies in a newborn or an infant with a developmental defect of the cranial vault.
Managerial Assessments of Export Performance: Conceptual Framework and Empirical Illustration
Authors: Diamantopoulos Adamantios , Kakkos Nikolaos
Published: August 2007

Export performance has long been an issue of concern in the literature; however, there has been little research on managers’ evaluations of their firms’ performance in the presence of multiple export objectives. This study proposes a framework for understanding managerial assessments of export performance and illustrates its application using the analytic hierarchy process methodology. The framework explicitly acknowledges that the importance of different export objectives may differ both within and between firms and that the latter may also differ in terms of the frame of reference and/or time horizon used when assessing the attainment of objectives. Using this framework, the authors construct a composite index of assessed export performance that allows for valid interfirm comparisons. They use data from an online survey of 171 exporting firms to demonstrate the application of the framework and the assessed export performance index in an empirical setting.
An improved method for staining chromosomes of marine algae
Authors: Wang Juan , Dai Jixun , Zhang Yiting
Published: August 2007

An improved staining method using carbol fuchsin was successfully adopted for chromosomes of marine algae, includingPorphyra,Undaria pinnatifidaandSaccharina japonica. The haploid numbers ofP. haitanensisandP. yezoensis(observed clearly in vegetative, spermatangial and conchosporangial cells) were five and three, respectively. The diploid numbers ofP. haitanensisandP. yezoensis(in immature conchosporangial cells) were ten and six, respectively. Pit connections between cells of conchosporangia and cell mashes were clearly differentiated. Chromosomes in conchocelis cells in prophase were clearly stained with the improved carbol fuchsin method. The chromosome number of gametophytes ofS. japonicawas 31, and that ofU. pinnatifidawas 30. Hydrolysis with 1 M HCl at 60°C for 7–8 min to produce a very transparent cytoplasm was necessary for staining chromosomes in conchosporangial branches ofPorphyra. Iron alum acetocarmine, aceto-iron-hematoxylin-chloral hydrate and carbol fuchsin were used to stain the chromosomes of the vegetative cells, spermatangial cells and conchosporangial cells ofPorphyraand the gametophytes ofU. pinnatifidaandS. japonica. Among the three methods, the carbol fuchsin method was simple and rapid, yielding deep staining of chromosomes and good contrast between the nucleus and cytoplasm.
Characterization of Gracilaria lemaneiformis Bory (Gracilariaceae, Rhodophyta) cultivars in China using the total soluble proteins and RAPD analysis
Authors: Wang Wen-jun , Wang Guang-ce , Gao Zheng-quan , Lin Xiang-zhi , Xu Pu
Published: August 2007

The cultivars of Gracilaria lemaneiformis in Nanao (Guangdong province), Putian (Fujian) and Lianyungang (Jiangsu) all originate from the Qingdao (Shandong) wild population. After years of cultivation via vegetative propagation in marine farms in their new habitats, these cultivars vary in economic properties and morphological characters. In order to demonstrate whether the variations are caused by genetic variation or habitat shift, Gracilaria asiatica as an outgroup, the three cultivars, together with two morphologically different wild populations in Qingdao were characterized by RAPD markers and total soluble proteins. The results consistently showed that: (1) The Nanao cultivar, a selected strain enduring higher temperature, had the most variations. (2) The other two cultivars were closely related to one other. (3) The morphologically differentiated G. lemaneiformis populations in Qingdao were two separate populations. The results indicate that the use of RAPD markers is a powerful tool for exploring genetic relationships among G. lemaneiformis populations. Morphological and phenotypic variations of the cultivars are due to genetic changes rather than environmental changes. Years of artificial selection and asexual propagation have led to a reduction of intra-population genetic diversity in farmed populations and successive transplantation between farms has caused a reduction of inter-population genetic differentiation.
Antiviral activity of a sulfoquinovosyldiacylglycerol (SQDG) compound isolated from the green alga Caulerpa racemosa
Authors: Wang Hui , Li Yao-Lan , Shen Wei-Zai , Rui Wen , Ma Xia-Jun , Cen Ying-Zhou
Published: August 2007

An invasive green alga, Caulerpa racemosa, collected from the South China Sea was tested for its antiviral properties. Hot water extracts and the n-butanol fraction obtained showed potent inhibition of herpes simplex virus type 1 (HSV-1) and Coxsackie virus B3 (Cox B3). A sulfoquinovosyldiacylglycerol (SQDG) compound was isolated and purified from the n-butanol fraction following further antiviral-guided fractionation. The SQDG compound exhibited an excellent antiviral effect against HSV-2, with a 50% inhibitory concentration (IC50) of 15.6 μg ml-1 against both standard and clinical strains of HSV-2, but showed only moderate antiviral effects against HSV-1 and Cox B3. The SQDG compound was chemically characterized using spectroscopic methods as (2S)-1,2-di-O-palmitoyl-3-O-(6′-sulfo-α-D-quinovopyranosyl) glycerol. This is the first isolation from C. racemosa of this SQDG compound with notable selective antiviral activity against HSV-2.
Evaluate the Simple Surface Energy of Aggregates Using the Capillary Rise Method
Authors: Sinkonde Dennis , Wen Hao Pei , Yi Xiao Qing
Published: August 2007

This paper describes the evaluation of surface energy of two types of aggregates, a limestone and granite, using the capillary rise method. The capillary rise method is a simple method that can successfully be used to determine the surface energy of powders. Contact angle measurements were performed using the capillary rise method and, thereafter, surface energy of aggregates was determined using the Young-Dupré equation. The results of the experiment indicate that limestone had a slightly higher surface energy compared to granite. The two aggregates had almost equal apolar components of the surface energy whilst the polar components were quite different.
Effect of humic acid on sorption of neptunium on hematite colloids
Authors: Jain Aishwarya , Rawat Neetika , Kumar Sumit , Tomar Bhupendra S. , Manchanda V. K. , Ramanathan S.
Published: August 2007

Sorption of neptunium on hematite colloids has been studied at varying pH values (3–10) in absence and presence of humic acid using239Np as a tracer. The experiments were carried out under aerobic and anaerobic conditions. The results show negligible sorption of Np(V) on hematite colloids at lower pH<5, beyond which it was found to increase sharply reaching ∼90% at pH 10. Presence of humic acid (2mg/L) was found to decrease the sorption of Np(V) on hematite at higher pH values while at lower pH the effect was found to be negligible. The stability constant of Np(V)-humate complex (logβ) was determined to be 4.2±0.2 by solvent extraction method. Sorption of humic acid on hematite as a function of pH was also measured by UV-visible spectrophotometry. Under nitrogen atmosphere and in presence of sodium dithionite, Np(V) was reduced to Np(IV) as evident by the enhanced sorption at all pH values, which was further enhanced in presence of humic acid at lower pH. However at higher pH values, humic acid does not affect the sorption of neptunium under reducing conditions, which could be due to competing reduction process involving ferric ions obtained from dissolved hematite.
Solubility study of Tc(IV) in a granitic water
Authors: Liu D. J. , Yao J. , Wang B. , Bruggeman C. , Maes N.
Published: August 2007

The deep geological disposal of the high level radioactive wastes is expected to be a safe disposal method in most countries. The long-lived fission product99Tc is present in large quantities in nuclear wastes and its chemical behavior in aqueous solution is of considerable interest. Under oxidizing conditions technetium exists as the anionic species TcO4−whereas under the reducing conditions, expected to exist in a deep geological repository, it is generally predicted that technetium will be present as TcO2·nH2O. Hence, the mobility of Tc(IV) in reducing groundwater may be limited by the solubility of TcO2·nH2O under these conditions. Due to this fact it is important to investigate the solubility of TcO2·nH2O. The solubility determines the release of radionuclides from waste form and is used as a source term in radionuclide migration analysis in performance assessment of radioactive waste repository. Technetium(IV) was prepared by reduction of a technetate solution with Sn2+. The solubility of Tc(IV) has been determined in simulated groundwater and redistilled water under aerobic and anaerobic conditions. The effects of pH and CO32−concentration of solution on solubility of Tc(IV) were studied. The concentration of total technetium and Tc(IV) species in the solutions were periodically determined by separating the oxidized and reduced technetium species using a solvent extraction procedure and counting the beta activity of the99Tc with a liquid scintillation counter. The experimental results show that the rate of oxidation of Tc(IV) in simulated groundwater and redistilled water is about (1.49∼1.86)×10−9mol L−1d−1under aerobic conditions, while no Tc(IV) oxidation was detected in simulated groundwater and redistilled water under anaerobic conditions. Under aerobic or anaerobic conditions the solubility of Tc(IV) in simulated groundwater and redistilled water is equal on the whole after centrifugation or ultrafiltration. The solubility of Tc(IV) increases with the decrease of pH at pH<2, increases with the increase of pH at pH>11 and is pH independent in the range 2<pH<11. The concentrations of Tc(IV) species were in the range of 10−8to 10−9mol L−1at 2<pH<11. The solubility of Tc(IV) slightly increases with increasing the increase of CO32−concentration. Geochemical modelling showed a good agreement between our experimental results and thermodynamic constants from the NEA TDB review. These data could be used to estimate the Tc(IV) solubility for cases where solubility limits transport of technetium in reducing environments of high-level waste repositories.
Administration of Granulocyte Colony-Stimulating Factor After Myocardial Infarction Enhances the Recruitment of Hematopoietic Stem Cell-Derived Myofibroblasts and Contributes to Cardiac Repair
Authors: Fujita Jun , Mori Mitsuharu , Kawada Hiroshi , Ieda Yasuyo , Tsuma Mitsuyo , Matsuzaki Yumi , Kawaguchi Haruko , Yagi Takashi , Yuasa Shinsuke , Endo Jin , Hotta Tomomitsu , Ogawa Satoshi , Okano Hideyuki , Yozu Ryohei , Ando Kiyoshi , Fukuda Keiichi
Published: August 2007

The administration of granulocyte colony-stimulating factor (G-CSF) after myocardial infarction (MI) improves cardiac function and survival rates in mice. It was also reported recently that bone marrow (BM)-derived c-kit+ cells or macrophages in the infarcted heart are associated with improvement of cardiac remodeling and function. These observations prompted us to examine whether BM-derived hematopoietic cells mobilized by G-CSF administration after MI play a beneficial role in the infarct region. A single hematopoietic stem cell from green fluorescent protein (GFP)-transgenic mice was used to reconstitute hematopoiesis in each experimental mouse. MI was then induced, and the mice received G-CSF for 10 days. In the acute phase, a number of GFP+ cells showing the elongated morphology were found in the infarcted area. Most of these cells were positive for vimentin and α-smooth muscle actin but negative for CD45, indicating that they were myofibroblasts. The number of these cells was markedly enhanced by G-CSF administration, and the enhanced myofibroblast-rich repair was considered to lead to improvements of cardiac remodeling, function, and survival rate. Next, G-CSF-mobilized monocytes were harvested from the peripheral blood of GFP-transgenic mice and injected intravenously into the infarcted mice. Following this procedure, GFP+ myofibroblasts were observed in the infarcted myocardium. These results indicate that cardiac myofibroblasts are hematopoietic in origin and could arise from monocytes/macrophages. MI leads to the recruitment of monocytes, which differentiate into myofibroblasts in the infarct region. Administration of G-CSF promotes this recruitment and enhances cardiac protection. Disclosure of potential conflicts of interest is found at the end of this article.
Unique Glycerophospholipid Signature in Retinal Stem Cells Correlates with Enzymatic Functions of Diverse Long-Chain Acyl-CoA Synthetases
Authors: Li Jianxue , Cui Zheng , Zhao Sheyun , Sidman Richard L.
Published: August 2007

Lipidomics is an emerging research field that comprehensively characterizes lipid molecular species and their metabolic regulation and biological roles. We performed the first lipidomics study on glycerophospholipids (GPLs) in adult mammalian retinal stem cells (RSCs) and non-RSC control cells. A unique GPL signature identified by electrospray ionization tandem mass spectrometry showed new prominent peaks of 16:0 (sn-1)-18:0 (sn-2) or 16:0–16:0 saturated fatty acids, instead of 18:0–20:4 or 18:0–22:6 polyunsaturated essential fatty acids, at 720 m/z of phosphatidylethanolamine, 764 m/z of phosphatidylserine, and 809 m/z of phosphatidylinositol in RSCs (sphere colony RSCs and enriched RSCs), but not in non-RSCs (retinal cells, ciliary cells, sphere colony-derived retinal cells, and nonretinal cells). To seek whether the GPL signature was associated with long-chain acyl-CoA synthetase (LACS), a potential modulator of fatty acid profiles in de novo GPL synthesis, we analyzed gene expression, catabolic activity, substrate selectivity, and inhibitor sensitivity of diverse LACSs. LACSs in RSCs mediated less utilization by GPLs of polyunsaturated essential fatty acids, including arachidonic acid (20:4 [n-6], a second messenger in cell signaling), which was accompanied by lower plasma membrane fluidity in proliferating RSCs compared with differentiated non-RSCs. These novel findings suggest that LACS-associated GPL signature and cell membrane fluidity may participate in regulating proliferation versus differentiation in RSCs and, perhaps, other types of stem cells.

Disclosure of potential conflicts of interest is found at the end of this article.
Concise Review: Hematopoietic Stem Cells and Tissue Stem Cells: Current Concepts and Unanswered Questions
Authors: Metcalf Donald
Published: August 2007

The term hematopoietic stem cells has at times been used to include a miscellany of precursor cells ranging from multipotential self-generating cells to lineage-restricted progenitors with little capacity for self-generation. It is probable that the stem cells of other tissues also vary widely in their multipotentiality and proliferative capacity. This review questions several dogmas regarding the self-generative capacity of various hematopoietic cells, the single episodic origin of hematopoietic cells, and the irreversible nature of progressive mature cell formation in individual hematopoietic lineages.

Disclosure of potential conflicts of interest is found at the end of this article.
Potential Impact of Precision Nitrogen Management on Corn Yield, Protein Content, and Test Weight
Authors: Miao Yuxin , Mulla David J. , Hernandez Jose A. , Wiebers Matt , Robert Pierre C.
Published: August 2007

Precision crop management for optimizing yield and quality is important for developing a consistent product for different end uses of grain. This study was conducted to evaluate the potential impact of variable‐rate N (VRN) application, hybrid selection, and hybrid‐specific N management on corn (Zea mays L.) yield, protein content, and test weight. On‐farm experiments were conducted during three site‐years in eastern Illinois using a split‐plot design, with the main plots consisting of five N rates and the subplots two corn hybrids (Pioneer 33G26 and 33J24). Nitrogen response curves of corn yield and quality were fitted at 19 and 16 within‐field locations in Fields 1 and 2, respectively, and the potential impacts of different N management strategies were evaluated. Results indicated that within‐field economically optimum N rates (EONR) ranged from 82 to 336 kg N ha−1, while N rates that would maximize grain quality ranged from 0 to 336 kg N ha−1 Compared with a uniform‐rate N (URN) application of 168 kg N ha−1, the VRN application at EONR would increase corn yield for hybrid 33J24 while having an inconsistent impact on yield of 33G26, without significantly improving grain quality of either hybrid. Hybrid 33J24 would have higher yield, quality, and economic returns than 33G26 under either URN or VRN application. Hybrid‐specific N applications could have either negative or positive impacts on corn yield and protein content, without significantly affecting test weight. These results suggest that selecting the right hybrid(s) was more important and practical than the evaluated precision N management practices for optimizing both corn yield and grain quality during the study site‐years.
Mechanical Stresses in Soils Assessed from Bulk‐Density and Penetration‐Resistance Data Sets
Authors: Horn R. , Hartge K. H. , Bachmann J. , Kirkham M. B.
Published: August 2007

Measurement of soil strength with sophisticated parameters is tedious and expensive. Therefore, we developed two straightforward methods to determine this parameter down to about 80 cm, based on the classical measurements of bulk density and penetration resistance as a function of depth. They were applied to three profiles of arable Luvisols, all developed from glacial till. For each method, a procedure was worked out that allows expression of the results in terms of a normal (NC) or precompacted (PC) state. We defined the NC state as that observed in packing characteristics of virgin soils like forests and meadows, and the PC state as the packing characteristics that exist in the topsoil of agricultural soils and intensely grazed areas. Bulk density data were used to examine the packing characteristics and overburden pressures with the assumption that the horizon was in a NC state below 80 cm. For penetration resistance, we assumed a linear increase in penetration resistance with depth to represent the hydrostatic stress distribution in the NC state and deviations of measured values from this line as the PC state. The upper approximately 60 cm of all three soils were compacted, which is proofed both for the penetration resistance and for the bulk density data. For both approaches, the dimensionless coefficient of “stresses at rest,” K0, was calculated following the line of thought used in engineering soil mechanics (K0 = σx/σz, where σx and σz are the horizontal and vertical stresses, respectively). The K0 values are highest in the precompacted soil horizons and decrease with depth.
Temperature Quotients of Ammonia Emission of Different Nitrogen Sources Applied to Four Agricultural Soils
Authors: Liu G. D. , Li Y. C. , Alva A. K.
Published: August 2007

Emission of N as NH3 is the primary gaseous loss of N from N sources applied to soils. Knowledge of NH3 volatilization, however, in relation to temperature is incomplete. Soils used in this study were a Biscayne marl soil (BMS) and Krome gravelly loam (KGL) from Florida, and Quincy fine sand (QFS) and Warden silt loam (WSL) soils from Washington. These soils were amended with either KNO3, NH4NO3, (NH4)2SO4, or urea, and incubated at 11, 20, or 29°C under 20 or 80% field capacity (FC) soil water regimes. A change in the rate of NH3 emission corresponding to a 9°C change in temperature is expressed as the temperature quotient (Q9), which describes the temperature effect on rates of NH3 volatilization. At 20°C, the cumulative NH3 emission at 20% FC was up to 8.1‐fold greater than that at 80% FC. The Q9 values of NH3 emission from the WSL soil were up to 10‐fold greater than those from the other three soils amended with either (NH4)2SO4 or NH4NO3 The Arrhenius activation energy (Ea) was about 188 J mol−1 for the WSL soil but ≤42 J mol−1 for the other soils. Volatilization from the WSL soil was highly temperature dependent. These results indicate that Q9 and Ea could be used as indices for N management for crop production to minimize NH3 emissions. Further research is needed, however, to verify the above relationships across a wide range of soils and agroclimatic regions.
Water Erosion Estimation in Topographically Complex Landscapes: Model Description and First Verifications
Authors: Bonilla Carlos A. , Norman John M. , Molling Christine C.
Published: August 2007

Two of the most important limitations when predicting soil movement are the natural complexity and the spatial heterogeneity of the processes. Soil erosion can vary significantly across short distances as a function of local soil properties and microtopography; but regardless of this, many erosion models assume homogeneity in topography and soil characteristics. The objective of this research was to develop a method for estimating soil loss from agricultural fields that is faithful to the complex topography and spatial heterogeneity common to managed landscapes. Sediment loss for individual storms was achieved by linking soil detachment–deposition equations adapted from the Water Erosion Prediction Project (WEPP) model to the existing water‐flow subroutine in the Precision Agricultural‐Landscape Modeling System (PALMS). In PALMS, sediment was routed appropriately in a two‐dimensional grid, defining the pathways taken by the eroded material. Usually PALMS works on a grid‐cell size of 5 to 20 m and simulates runoff and soil erosion patterns as affected by slope, soil texture, anisotropic surface roughness, soil consolidation, canopy cover, and tillage interactions with topography. In this study, PALMS and WEPP were used to simulate the sediment transport on an idealized field with a complex hillslope profile. Both models showed a consistent soil loss pattern and only minor differences in transport capacities. The models were also compared with data from actual erosion plots, where both runoff and soil loss were predicted with similar errors for both PALMS and WEPP. To illustrate the capability of PALMS, it was applied to a field with complex topography.