bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time and magnitude of torque generation is impaired in both arms following stroke
Authors: McCrea Patrick H. , Eng Janice J. , Hodgson Antony J. 
Published: June 2003

AbstractMuscle strength, usually measured as the peak torque during maximal contraction, is impaired in persons with stroke. Time‐dependent properties of muscle contraction may also be altered but have not been quantified. We quantified both magnitude (peak torque) and time‐dependent parameters (times to develop and reduce torque) in eight different isometric joint actions. Parameters were compared among the more and less affected arms of 20 persons with chronic stroke and the nondominant arms of 10 similarly aged healthy persons. Torque‐generation parameters were independent from one another (i.e., low correlations) and highly reliable between trials and days. All parameters were impaired in the more affected arm, whereas peak torque and time to develop torque were impaired in the less affected arm. Following stroke, torque‐generation impairments include both magnitude and time‐dependent properties and exist not only in the more affected but also in the less affected arm. Clinicians attempting to improve upper‐extremity function should employ therapeutic exercises that challenge patients to improve both their strength and speed of muscle contraction. Muscle Nerve 28: 46–53, 2003
Extension of the GOOD assay for genotyping single nucleotide polymorphisms by matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Sauer Sascha , Gut Ivo G. 
Published: June 2003

AbstractOver the past years several methods using mass spectrometry for high‐throughput genotyping of single nucleotide polymorphisms (SNPs) have been developed. Most of these procedures require stringent purification. Only the GOOD assay does not need any sample purification. Here, several new implementations of this assay are presented. The molecular biological procedure of the GOOD assays is based on the principle that the analysis of DNA by matrix‐assisted laser desorption/ionization (MALDI) is strongly dependent on the charge state. A 100‐fold increase in sensitivity can be achieved if the analyzed DNA product is conditioned by a chemical procedure termed ‘charge‐tagging’. The GOOD assay starts with a PCR; allele‐specific DNA molecules are generated by extension of modified primers. These contain up to three phosphorothioates and optionally a quaternary ammonium charged group with ddNTPs or α‐S‐ddNTPs. Then the unmodified part of the primers is digested by phosphodiesterase II and the negative charges of the phosphorothioates are neutralized by an alkylation reaction resulting in charge‐tagged DNA products. Through the use of a novel DNA polymerase for the primer extension, which preferably incorporates ddNTPs over dNTPs, an enzymatic degradation of residual dNTPs from the PCR is not required. Additionally, the unique property of charge‐tag technology is demonstrated to detect specifically on the same sample allele‐specific DNA products carrying a positive charge‐tag in the positive ion mode while products carrying a negative charge‐tag are analyzed in the negative ion mode. We also generated zwitterionic allele‐specific products that were detectable with high sensitivity in positive ion mode. The findings of this study raise interesting questions about the ionization process of nucleic acids in MALDI. The new variations of the GOOD assay were applied to genotype SNPs of a candidate gene for cardiovascular disease. Copyright © 2003 John Wiley & Sons, Ltd.
Polycapillary x‐ray optics: manufacturing status, characterization and the future of the technology
Authors: Gao N. , Ponomarev I. Y. 
Published: June 2003

AbstractThe design, manufacturing and characterization of polycapillary x‐ray optics are essential to improve and verify the performance of the optics. Important issues with regard to each of these processes are reviewed and discussed. Specific topics include the optimum design to achieve small focal spot for focusing optics and small beam divergence for collimating optics. Different characterization methods for measuring spot size and beam divergence are compared and discussed. The performance of different types of optics was evaluated and the future development of the technology is reviewed and discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Haemoglobin during pregnancy: relationship to erythropoietin and haematinic status
Authors: McMullin Mary Frances , White Raymond , Lappin Terence , Reeves John , MacKenzie Gilbert 
Published: June 2003

Abstract: Objective: To investigate the effect of haematinic status on erythropoietin throughout pregnancy in order to assess whether haematinic supplementation is appropriate for all pregnant women or should be reserved for individuals in whom deficiency has been identified.Methods: A prospective, repeated‐measures, longitudinal study of 263 women enrolled at an antenatal clinic in a district general hospital who received standard obstetric management including haematinic supplements. Haematological indices, iron status, folate and B12 status, and erythropoietin levels were measured by standard methods at scheduled intervals throughout pregnancy. The relationships between the measurements were analysed using statistical models which took into account the serial correlation between repeated measurements on the same individuals.Results: Erythropoietin levels rose throughout pregnancy from a mean of 22.8 mU/mL at booking to 43.7 mU/mL at 38 wk. There was a significant relationship between erythropoietin levels and haemoglobin, ferritin, TIBC and folate. The relationship was strongest between erythropoietin and haemoglobin. Erythropoietin levels were influenced by parity but not maternal age.Conclusion: Haematinic levels, particularly iron are related to the rise in serum EPO which occurs during pregnancy. Therefore, haematinic deficiency in pregnancy will result in increased stimulation of erythroid progenitor cells by erythropoietin. While haematinic supplementation is not always prescribed throughout pregnancy, haematinic status must be assessed on an individual basis and supplementation provided as required.
Development of novel oligonucleotide probes for seven Actinomyces species and their utility in supragingival plaque analysis
Authors: Tang G , Yip H‐K , Luo G , Cheung BPK , Shen S , Samaranayake LP 
Published: June 2003

OBJECTIVE: The traditional, biochemical and enzymatic methods of identifying Actinomyces species are frequently confounded by the similar phenotypic characteristics shared by the different members of this genus. Therefore, we developed novel species‐specific oligonucleotide probes to accurately speciate seven pathogenic Actinomyces species, namely, Actinomyces bovis, A. gerencseriae, A. israelii, A. meyeri, A. naeslundii, A. odontolyticus and A. viscosus. METHODS: A pair of universal primers and seven 15‐ to 19‐base oligonucleotide probes with a tail of 20 thymidines on the 5′ end were developed. The variable regions of 16S ribosomal DNA of 36 strains of Actinomyces belonging to the above species were amplified and labeled with digoxigenin, and an oligonucleotide‐DNA hybridization assay was performed to examine the specificity and sensitivity of these probes. RESULTS: All seven, newly developed probes were specific and sensitive, and accurately detected 36 reference and wild type strains belonging to Actinomyces species, without cross‐reactions. The probe for A. naeslundii detected all strains belonging to the genospecies 1 (12 strains) and catalase‐negative genospecies 2 (four strains); it failed to detect catalase‐positive A. naeslundii genospecies 2 (previous A. viscosus serotype II) (two strains). However, the latter strains of catalase‐positive A. naeslundii genospecies 2 were correctly detected by the probe developed for A. viscosus. The new probes were then field tested using supragingival plaque samples from 28 healthy preschool children. Whilst A. odontolyticus was detected in almost all samples (96.4%), A. gerencseriae, A meyeri, catalase‐negative A. naeslundii and catalase‐positive A. naeslundii genospecies 2 were detected in <50% samples. CONCLUSION: We conclude that the developed oligonucleotide probes, complementary to the variable regions of 16S rDNA, would be of potential value for differentiating Actinomyces spp. in clinical samples from the oral cavity and other ecosystems where such species may abound.
Paediatric brain tumour, a 10‐year local experience (1992–2001)
Authors: Hung Wai‐Man , Fong Dawson 
Published: June 2003

Objective:  To report our local experience on incidence and outcomes of different paediatric brain tumour.Methods:  A detailed data search was carried out from our operative records and histopathology database. A total of 48 paediatric patients bearing 49 brain tumours (one patient had two tumours) within the period between 1992 and 2001 was retrieved. The discharge summary, out‐patient follow‐up record was examined for each patient. The data was grouped according to different pathology type.Results:  The results were mainly concentrating over several selected pathologies: (i) low‐grade glioma; (ii) high‐grade glioma; (iii) germ cell tumour; (iv) medulloblastoma; and (v) craniopharyngioma.Conclusions:  The most prevalent pathology in our experience is low‐grade astrocytoma, followed by germ cell cell tumour and medulloblatoma. The highest mortality rate is high‐grade glioma.
Survey on the working hours and workload of public sector surgeons in Hong Kong
Authors: Yip Andrew Wai‐Chun 
Published: June 2003

Introduction:  The College of Surgeons of Hong Kong commissioned the Public Opinion Programme (POP) of the University of Hong Kong in April 2002 to conduct a survey on the working hours and workloads of all in‐service public sector surgeons in Hong Kong. The research instrument used, as well as the fieldwork operation and data analysis, were all conducted independently by the POP team.Methods:  All in‐service public sector surgeons in Hong Kong were invited to participate in the survey from 23 to 29 September 2002, which consisted of a daily work diary and seven opinion questions on workload, work morale and quality of life.Results and Conclusions:  A total of 264 of the 486 eligible surgeons participated in the survey. The average daily work hour was 10.3 h and the average weekly work hour was 72 h. A total of 45% of the respondents worked for more than 10 h everyday. In the respondents’ opinion, 60.9% claimed they were overworked, 31% were satisfied with their own morale and 51% evaluated their own quality of life as unsatisfactory.
Nitric oxide signalling in plants
Authors: Neill Steven J. , Desikan Radhika , Hancock John T. 
Published: June 2003

SummaryRecently nitric oxide (NO) has emerged as a key signalling molecule in plants. Here we review the potential sources of endogenous NO, outline the biological processes likely to be mediated by NO, and discuss the downstream signalling processes by which NO exerts its cellular effects. It will be important to develop methods to quantify intracellular NO synthesis and release. Clasification of the biosynthetic origins of NO is also required. NO can be synthesised from nitrite via nitrate reductase (NR) and although biochemical and immunological data indicate the presence of enzyme(s) similar to mammalian nitric oxide synthase (NOS), no NOS genes have been identified. NO can induce various processes in plants, including the expression of defence‐related genes and programmed cell death (PCD), stomatal closure, seed germination and root development. Intracellular signalling responses to NO involve generation of cGMP, cADPR and elevation of cytosolic calcium, but in many cases, the precise biochemical and cellular nature of these responses has not been detailed. Research priorities here must be the reliable quantification of downstream signalling molecules in NO‐responsive cells, and cloning and manipulation of the enzymes responsible for synthesis and degradation of these molecules.

Contents

Summary
11

1
Introduction
12

2
Why does NO make a good signal?
12

3
NO biosynthesis
13

4
NO biology
17

5
NO signal transduction
23

6
Conclusion
30

Acknowledgements
31

References
31
Ketoprofen, Acetaminophen, and Placebo in the Treatment of Tension Headache
Authors: Mehlisch Donald R. , Weaver Melanie , Fladung Bernward 
Published: June 2003

Seven hundred three subjects completed a randomized, double‐blind, parallel‐group, single‐center study comparing the single‐dose efficacy of ketoprofen 12.5 mg, ketoprofen 25 mg, acetaminophen 1000 mg, and placebo in the treatment of tension headache.For the primary efficacy variable, 4‐hour sum of pain relief intensity differences, ketoprofen 25 mg was significantly superior to placebo. Ketoprofen 25 mg also demonstrated superior pain relief in the first hour after dosing, and the time to meaningful pain relief was significantly shorter for the ketoprofen 25‐mg group. Ketoprofen 12.5 mg proved to be significantly superior to placebo for pain relief intensity difference and pain relief at 3 hours, global assessment of medication at 4 hours, and for time to onset of meaningful pain relief. The data suggest a dose response for ketoprofen 12.5 mg and 25 mg.Acetaminophen 1000 mg proved to be numerically more favorable than placebo in most variables, but could not be separated from placebo with statistical significance. In spite of possible inflation of the placebo response due to sensitivity limits of the study, ketoprofen 25 mg demonstrated a more rapid onset of analgesia compared to acetaminophen 1000 mg, and patients' global assessment rated ketoprofen 25 mg higher than acetaminophen 1000 mg.
The Arabidopsis CDPK-SnRK Superfamily of Protein Kinases
Authors: Hrabak Estelle M. , Chan Catherine W.M. , Gribskov Michael , Harper Jeffrey F. , Choi Jung H. , Halford Nigel , Kudla Jörg , Luan Sheng , Nimmo Hugh G. , Sussman Michael R. , Thomas Martine , Walker-Simmons Kay , Zhu Jian-Kang , Harmon Alice C. 
Published: June 2003

Abstract
The CDPK-SnRK superfamily consists of seven types of serine-threonine protein kinases: calcium-dependent protein kinase (CDPKs), CDPK-related kinases (CRKs), phosphoenolpyruvate carboxylase kinases (PPCKs), PEP carboxylase kinase-related kinases (PEPRKs), calmodulin-dependent protein kinases (CaMKs), calcium and calmodulin-dependent protein kinases (CCaMKs), and SnRKs. Within this superfamily, individual isoforms and subfamilies contain distinct regulatory domains, subcellular targeting information, and substrate specificities. Our analysis of the Arabidopsis genome identified 34 CDPKs, eight CRKs, two PPCKs, two PEPRKs, and 38 SnRKs. No definitive examples were found for a CCaMK similar to those previously identified in lily (Lilium longiflorum) and tobacco (Nicotiana tabacum) or for a CaMK similar to those in animals or yeast. CDPKs are present in plants and a specific subgroup of protists, but CRKs, PPCKs, PEPRKs, and two of the SnRK subgroups have been found only in plants. CDPKs and at least one SnRK have been implicated in decoding calcium signals in Arabidopsis. Analysis of intron placements supports the hypothesis that CDPKs, CRKs, PPCKs and PEPRKs have a common evolutionary origin; however there are no conserved intron positions between these kinases and the SnRK subgroup. CDPKs and SnRKs are found on all five Arabidopsis chromosomes. The presence of closely related kinases in regions of the genome known to have arisen by genome duplication indicates that these kinases probably arose by divergence from common ancestors. The PlantsP database provides a resource of continuously updated information on protein kinases from Arabidopsis and other plants.
A Resource of Mapped Dissociation Launch Pads for Targeted Insertional Mutagenesis in the Arabidopsis Genome
Authors: Muskett Paul R. , Clissold Leah , Marocco Adriano , Springer Patricia S. , Martienssen Robert , Dean Caroline 
Published: June 2003

Abstract
We describe a new resource for targeted insertional mutagenesis in Arabidopsis using a maize (Zea mays) Activator/Dissociation (Ds) two-element system. The two components of the system, T-DNA vectors carrying a Ds launch pad and a stable Activator transposase source, were designed to simplify selection of transposition events and maximize their usefulness. Because Ds elements preferentially transpose to nearby genomic sites, they can be used in targeted mutagenesis of linked genes. To efficiently target all genes throughout the genome, we generated a large population of transgenic Arabidopsis plants containing the Ds launch pad construct, identified lines containing single Ds launch pad inserts, and mapped the positions of Ds launch pads in 89 lines. The integration sites of the Ds launch pads were relatively evenly distributed on all five chromosomes, except for a region of chromosomes 2 and 4 and the centromeric regions. This resource therefore provides access to the majority of the Arabidopsis genome for targeted tagging.
ArabidopsishotMutants Define Multiple Functions Required for Acclimation to High Temperatures
Authors: Hong Suk-Whan , Lee Ung , Vierling Elizabeth 
Published: June 2003

AbstractPlants acquire thermotolerance to lethal high temperatures if first exposed to moderately high temperature or if temperature is increased gradually to an otherwise lethal temperature. We have taken a genetic approach to dissecting acquired thermotolerance by characterizing loss-of-function thermotolerance mutants in Arabidopsis. In previous work, we identified single recessive alleles of four loci required for thermotolerance of hypocotyl elongation, hot1-1, hot2-1, hot3-1, and hot4-1. Completed screening of M2 progeny from approximately 2500 M1 plants has now identified new alleles of three of these original loci, along with three new loci. The low mutant frequency suggests that a relatively small number of genes make a major contribution to this phenotype or that other thermotolerance genes encode essential or redundant functions. Further analysis of the original four loci was performed to define the nature of their thermotolerance defects. Although the HOT1 locus was shown previously to encode a major heat shock protein (Hsp), Hsp101, chromosomal map positions indicate that HOT2, 3, and 4 do not correspond to major Hsp or heat shock transcription factor genes. Measurement of thermotolerance at different growth stages reveals that the mutants have growth stage-specific heat sensitivity. Analysis of Hsp accumulation shows that hot2 and hot4 produce normal levels of Hsps, whereas hot3 shows reduced accumulation. Thermotolerance of luciferase activity and of ion leakage also varies in the mutants. These data provide the first direct genetic evidence, to our knowledge, that distinct functions, independent of Hsp synthesis, are required for thermotolerance, including protection of membrane integrity and recovery of protein activity/synthesis.
AtSig5 Is an Essential Nucleus-Encoded Arabidopsis σ-Like Factor
Authors: Yao Junlan , Roy-Chowdhury Sanchita , Allison Lori A. 
Published: June 2003

Abstract
Transcription of chloroplast genes is subject to control by nucleus-encoded proteins. The chloroplast-encoded RNA polymerase (PEP) is a eubacterial-type RNA polymerase that is presumed to assemble with nucleus-encoded σ-factors mediating promoter recognition. Recently, families of σ-factor genes have been identified in several plants including Arabidopsis. One of these genes, Arabidopsis SIG5, encodes a σ-factor, AtSig5, which is phylogenetically distinct from the other family members. To investigate the role of this plant σ-factor, two different insertional alleles of the SIG5 gene were identified and characterized. Heterozygous mutant plants showed no visible leaf phenotype, but exhibited siliques containing aborted embryos and unfertilized ovules. Our inability to recover plants homozygous for a SIG5 gene disruption indicates that SIG5 is an essential gene. SIG5 transcripts accumulate in flower tissues, consistent with a role for AtSig5 protein in reproduction. Therefore, SIG5 encodes an essential member of the Arabidopsis σ-factor family that plays a role in plant reproduction in addition to its previously proposed role in leaf chloroplast gene expression.
Use of Serial Analysis of Gene Expression Technology to Reveal Changes in Gene Expression in Arabidopsis Pollen Undergoing Cold Stress
Authors: Lee Ji-Yeon , Lee Dong-Hee 
Published: June 2003

AbstractWe have characterized the global gene expression patterns of Arabidopsis pollen using Serial Analysis of Gene Expression (SAGE). A total of 21,237 SAGE tags were sequenced and 4,211 unique tags were identified. Interestingly, the number of unique tags in pollen was low compared with the SAGE library of the leaf constructed on a similar scale. The transcript profiles of pollen reflect accurately the characteristics of pollen as a reproductive organ. Functional classification of the expressed genes reveals that those involved in cellular biogenesis such as polygalacturonase, pectate lyase, and pectin methylesterase make up more than 40% of the total transcripts. However, genes involved in energy and protein synthesis, which are prevalent in leaves, were expressed at a relatively low level. The expression level of the great majority of transcripts was unaffected by cold treatment at 0°C for 72 h, whereas pollen tube growth and seed production were substantially reduced. Interestingly, many genes thought to be responsible for cold acclimation such as COR, lipid transfer protein, and β-amylase, that are highly induced in Arabidopsis leaves, were only expressed at their normal level or weakly induced in the pollen. The expression patterns of the cold-responsive transcripts identified by SAGE were confirmed by microarray analysis. Our results strongly suggest that poor accumulation of proteins that play a role in stress tolerance may be why Arabidopsis pollen is cold sensitive.
Arabidopsis Contains a Large Superfamily of Acyl-Activating Enzymes. Phylogenetic and Biochemical Analysis Reveals a New Class of Acyl-Coenzyme A Synthetases
Authors: Shockey Jay M. , Fulda Martin S. , Browse John 
Published: June 2003

Abstract
Acyl-activating enzymes are a diverse group of proteins that catalyze the activation of many different carboxylic acids, primarily through the formation of a thioester bond. This group of enzymes is found in all living organisms and includes the acyl-coenzyme A synthetases, 4-coumarate:coenzyme A ligases, luciferases, and non-ribosomal peptide synthetases. The members of this superfamily share little overall sequence identity, but do contain a 12-amino acid motif common to all enzymes that activate their acid substrates using ATP via an enzyme-bound adenylate intermediate. Arabidopsis possesses an acyl-activating enzyme superfamily containing 63 different genes. In addition to the genes that had been characterized previously, 14 new cDNA clones were isolated as part of this work. The protein sequences were compared phylogenetically and grouped into seven distinct categories. At least four of these categories are plant specific. The tissue-specific expression profiles of some of the genes of unknown function were analyzed and shown to be complex, with a high degree of overlap. Most of the plant-specific genes represent uncharacterized aspects of carboxylic acid metabolism. One such group contains members whose enzymes activate short- and medium-chain fatty acids. Altogether, the results presented here describe the largest acyl-activating enzyme family present in any organism thus far studied at the genomic level and clearly indicate that carboxylic acid activation metabolism in plants is much more complex than previously thought.