bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymmetrical Distribution of
Neisseria
Miniature Insertion Sequence DNA Repeats among Pathogenic and Nonpathogenic
Neisseria
Strains
Authors: De Gregorio Eliana , Abrescia Chiara , Carlomagno M. Stella , Di Nocera Pier Paolo
Published: June 2003

Neisseria
miniature insertion sequences (
nemis
) are miniature DNA insertion sequences found in
Neisseria
species. Out of 57 elements closely flanking cellular genes analyzed by PCR, most were conserved in
Neisseria meningitidis
but not in
N. lactamica
strains. Since mRNAs spanning
nemis
are processed by RNase III at hairpins formed by element termini, gene sets could selectively be regulated in meningococci at the posttranscriptional level.
Synthesis of Polyfluorinated Alkynes, Novel Building Blocks for Fluorous Chemistry
Authors: Bříza Tomáš , Kvíčala Jaroslav , Paleta Oldřich
Published: May 2003

Ethynyldimethylphenylsilane (2) was lithiated with butyllithium and reacted with (perfluorohexyl)ethyl triflate (1) to afford silylated 4-(perfluorohexyl)butyne 3, which was deprotected with potassium fluoride to give 4-(perfluorohexyl)butyne 4. Lithiation of fluoroalkyne 4 with butyllithium followed by the addition of polyfluoroalkyl triflate 1 furnished bis(perfluorohexyl)butyne 5 in a moderate yield. Polyfluoroalkylated alkynes 3, 4 and 5 are perspective building blocks for fluorous chemistry, the sufficient nucleophilic properties of which are preserved by one or two ethylene spacers between the triple bond and perfluoroalkyl group(s).
Electrochemical Reduction of 6-Benzylaminopurine at Mercury Electrodes and Its Analytical Application
Authors: Tarkowská Danuše , Kotouček Milan , Doležal Karel
Published: May 2003

The commercial exploitation of modern, in vitro plant micropropagation methods, featuring synthetic cytokinins as essential components of the cultivation media, is rapidly increasing. Thus, development of rapid, inexpensive and less labour-intensive methods for monitoring cytokinin levels could help to optimise media consumption and reduce costs. Therefore, we studied the electrochemical behaviour of the highly active and widely used cytokinin, 6-benzylaminopurine (BAP), in aqueous solutions by DC polarography, cyclic and differential pulse voltammetry and constant potential coulometry. The BAP molecule undergoes a six-electron irreversible reduction process that starts with four-electron reduction of the protonated pyrimidine skeleton. As a result of elimination of the amine from the side chain, the N1=C6 electrochemically active bond is re-established and the last two-electron step follows. The intermediates of constant potential electrolysis were identified using mass spectrometric analysis. The dissociation constant (pKa) of BAP was found, spectrophotometrically, to be 4.16. BAP concentrations were measured using two voltammetric techniques, fast-scan differential pulse (FSDPV) and adsorptive stripping voltammetry (AdSV). The relative standard deviations for these two methods were lower than 4.5% (c < 28.7 ng ml-1) and 1.2% (c < 20 ng ml-1), while the detection limits were 7.88 and 0.80 ng ml-1, respectively. Using these techniques, BAP was determined in two types of nutrition media used for the micropropagation of plants in vitro (Gerbera and banana media). In the case of media samples containing the interfering agent adenine (i.e. Gerbera plant medium), the analyte was preconcentrated by ion-exchange chromatography and immunoaffinity chromatography. This preconcentration process gives 92% recovery. In contrast, it was possible to determine BAP levels in simple banana cultivation medium directly, without any pre-purification process. Both methods, reported here (FSDPV and AdSV), were found to be useful for rapidly monitoring BAP consumption by plants during their growth under in vitro conditions.
Transition States of Cisplatin Binding to Guanine and Adenine: ab initio Reactivity Study
Authors: Chval Zdenek , Šíp Miroslav
Published: May 2003

Fully optimised HF and DFT transition states of cisplatin binding to adenine and guanine are presented for the first time. They have similar structure as the recently published transition states for cisplatin hydrolysis with the angle of about 70° between entering and leaving ligands and corresponding bonds prolonged up to 0.5 Å. Calculated activation energies are in the range of 10.5-18 kcal/mol. The lowest activation energies were found for the binding of cis-Pt[(NH3)2(H2O)(OH)]+ to guanine. The role of hydrogen bonds in recognition of binding sites, stabilisation of reactants and final yields of individual cisplatin-DNA adducts is discussed.
Synthesis of Polylactide with Thiol End Groups
Authors: Popelka Štěpán , Rypáček František
Published: May 2003

Four synthetic routes to poly(L-lactide) with thiol end groups based on ring-opening polymerization of L-lactide (LA) catalysed with tin(II) 2-ethylhexanoate (Sn(Oct)2) are reported. The following alcohols were used as co-initiators of polymerization: 2-sulfanylethan-1-ol, 2-[(2,4-dinitrophenyl)sulfanyl]ethan-1-ol, 2-(tritylsulfanyl)ethan-1-ol and allyl alcohol. End groups introduced into polymers by co-initiators were transformed to thiol groups by a subsequent modification reaction. The efficiencies of the used synthetic methods were evaluated and discussed. The best results were obtained with co-initiator 2-(tritylsulfanyl)ethan-1-ol.
Stereoselective Synthesis of the Two trans-(16-Hydroxymethyl)-3-methoxy-13α-estra-1,3,5(10)-trien-17-ol Isomers
Authors: Mernyák Erzsébet , Wölfling János , Bunkóczi Gábor , Luo Lingfei , Schneider Thomas R. , Schneider Gyula
Published: May 2003

Reduction of 16-(hydroxymethylidene)-3-methoxy-13α-estra-1,3,5(10)-trien-17-one yielded a mixture of two diastereomeric diols in the 6:1 ratio. The configurations of the newly formed stereogenic centres were determined by X-ray crystallography and NMR spectroscopy (NOE experiments) on the compounds in their cyclic acetaldehyde acetal forms.
Synthesis and Properties of the MFI Zincosilicalite
Authors: Giordano Girolamo , Katovič Andrea , Szymkowiak-Janiszewska Ewa , Kowalak Stanisław
Published: May 2003

Zincosilicalite MFI with various zinc contents (up to Zn/Si = 0.07) has been synthesized by hydrothermal crystallization. The samples with the Zn/Si ratio in the range 0.03-0.07 still show the crystalline structure of MFI, but they are less ordered and differ in properties from those with lower Zn contents. The mixtures with the Zn/Si ratios higher than 0.07 resulted in amorphous products or condensed crystalline phases (quartz). The introduction of Zn affected both the crystallization time and properties of the resulting products. Usually the higher Zn/Si ratio of the gel required a longer crystallization time. The zinc introduced affected the thermal template removal making it more difficult than for the zinc-free silicalite. The obtained zincosilicates were modified by ion-exchange with various cations. Contrary to zinc-free silicalite-1, they showed considerable catalytic activity in propan-2-ol decomposition and in cumene cracking. The activity usually increased with the Zn content up to the ratio Zn/Si = 0.03 and then decreased with rising Zn loading. It also depended on the cation introduced. The Cu-modifications resulted in dehydrogenation of propan-2-ol.
Multistage Organosolv Pulping: A Method for Obtaining Pulps with Low Hemicellulose Contents
Authors: Abad Severino , Santos Valentín , Parajó Juan Carlos
Published: May 2003

Two-stage treatments of Eucalyptus globulus wood were carried out in HCl-acetic acid-water media in order to obtain high-purity cellulose pulps. The effects of selected operational variables affecting the first pulping stage on the yield and composition of delignified solids were determined. A pulp selected from this study was used as substrate for a further pulping stage, which was carried out either at the normal boiling temperature or at 130 °C under a variety of conditions. This method was found to be particularly suitable for obtaining pulps with low hemicellulose contents.
Apolipoprotein AIV Gene Variant S347 Is Associated With Increased Risk of Coronary Heart Disease and Lower Plasma Apolipoprotein AIV Levels
Authors: Wong Wai-man R. , Hawe Emma , Li Lai K. , Miller George J. , Nicaud Viviane , Pennacchio Len A. , Humphries Steve E. , Talmud Philippa J.
Published: May 2003

The impact of common variants in the apolipoprotein gene cluster (
APOC3-A4-A5
) on prospective coronary heart disease (CHD) risk was examined in healthy UK men. Of the 2808 men followed over 9 years, 187 had a clinically defined CHD event. Examination of 9 single nucleotide polymorphisms (SNPs) in this group revealed that homozygotes for
APOA4
S347 had significantly increased risk of CHD [hazard ratio (HR) of 2.07 (95%CI 1.04 to 4.12)], whereas men homozygous for
APOC3
1100T were protected [HR 0.28 (95%CI 0.09 to 0.87)]. In stepwise multiple regression analysis, after entering all the variants and adjusting for established risk factors
APOA4
T347S alone remained in the model. Using all nine SNPs, the highest risk-estimate haplotypes carried
APOA4
S347 and rare alleles of the two flanking intergenic markers. The protective effect of
APOC3
1100T could be explained by negative linkage disequilibrium with these alleles. To determine the association of
APOA4
T347S with apoAIV levels, the relationship was examined in 1600 healthy young European men and women. S347 homozygotes had significantly lower apoAIV plasma levels (13.64±0.59 mg/dL) compared with carriers of the T347 allele (14.90±0.12 mg/dL) (
P
=0.035). These results demonstrate that genetic variation in and around
APOA4
, independent of the effects of triglyceride, is associated with risk of CHD and apoAIV levels, supporting an antiatherogenic role for apoAIV.
Contribution of Sodium Channel Mutations to Bradycardia and Sinus Node Dysfunction in LQT3 Families
Authors: Veldkamp Marieke W. , Wilders Ronald , Baartscheer Antonius , Zegers Jan G. , Bezzina Connie R. , Wilde Arthur A.M.
Published: May 2003

One variant of the long-QT syndrome (LQT3) is caused by mutations in the human cardiac sodium channel gene. In addition to the characteristic QT prolongation, LQT3 carriers regularly present with bradycardia and sinus pauses. Therefore, we studied the effect of the 1795insD Na
+
channel mutation on sinoatrial (SA) pacemaking. The 1795insD channel was previously characterized by the presence of a persistent inward current (
I
pst
) at −20 mV and a negative shift in voltage dependence of inactivation. In the present study, we first additionally characterized
I
pst
over the complete voltage range of the SA node action potential (AP) by measuring whole-cell Na
+
currents (
I
Na
) in HEK-293 cells expressing either wild-type or 1795insD channels.
I
pst
for 1795insD channels varied between 0.8±0.2% and 1.9±0.8% of peak
I
Na
. Activity of 1795insD channels during SA node pacemaking was confirmed by AP clamp experiments. Next,
I
pst
and the negative shift were implemented into SA node AP models. The −10-mV shift decreased sinus rate by decreasing diastolic depolarization rate, whereas
I
pst
decreased sinus rate by AP prolongation, despite a concomitant increase in diastolic depolarization rate. In combination, moderate
I
pst
(1% to 2%) and the shift reduced sinus rate by ≈10%. An additional increase in
I
pst
could result in plateau oscillations and failure to repolarize completely. Thus, Na
+
channel mutations displaying an
I
pst
or a negative shift in inactivation may account for the bradycardia seen in LQT3 patients, whereas SA node pauses or arrest may result from failure of SA node cells to repolarize under conditions of extra net inward current.
CD40 Is Constitutively Expressed on Platelets and Provides a Novel Mechanism for Platelet Activation
Authors: Inwald David P. , McDowall Alison , Peters Mark J. , Callard Robin E. , Klein Nigel J.
Published: May 2003

CD40 is a 48-kDa phosphorylated transmembrane glycoprotein belonging to the TNF receptor superfamily. CD40 has been demonstrated on a range of cell types, and it has an important role in adaptive immunity and inflammation. CD40 has recently been described on platelets but platelet activation by CD40 has not been described. In the present study, we use flow cytometry and immunoblotting to confirm that platelets constitutively express surface CD40. CD40 mRNA was undetectable, suggesting that the protein is synthesized early in platelet differentiation by megakaryocytes. Ligation of platelet CD40 with recombinant soluble CD40L trimer (sCD40LT) caused increased platelet CD62P expression, α-granule and dense granule release, and the classical morphological changes associated with platelet activation. CD40 ligation also caused β
3
integrin activation, although this was not accompanied by platelet aggregation. These actions were abrogated by the CD40L blocking antibody TRAP-1 and the CD40 blocking antibodies M2 and M3, showing that activation was mediated by CD40L binding to platelet CD40. β
3
integrin blockade with eptifibatide had no effect, indicating that outside-in signaling via α
IIb
β
3
was not contributing to these CD40-mediated effects. CD40 ligation led to enhanced platelet-leukocyte adhesion, which is important in the recruitment of leukocytes to sites of thrombosis or inflammation. Our results support a role for CD40-mediated platelet activation in thrombosis, inflammation, and atherosclerosis.
Protective Role of Angiopoietin-1 in Experimental Pulmonary Hypertension
Authors: Zhao Yidan D. , Campbell Andrew I.M. , Robb Malcolm , Ng Douglas , Stewart Duncan J.
Published: May 2003

Angiopoietin-1 (Ang-1), a newly discovered ligand of the endothelial-specific tyrosine kinase receptor Tie-2, has been found to promote cell survival, vascular maturation, and stabilization. We hypothesized that Ang-1 gene transfer to the pulmonary microcirculation would improve pulmonary hemodynamics and vascular remodeling in experimental pulmonary hypertension. Rat pulmonary artery smooth muscle cells were transfected with Ang-1 cDNA or null (pFLAG-CMV-1) vector. Syngeneic Fisher 344 rats were treated with monocrotaline (MCT) (75 mg/kg IP) with or without delivery of 5×10
5
Ang-1–transfected cells into the right jugular vein. After 28 days, plasmid-derived Ang-1 mRNA was consistently and robustly detected by reverse transcriptase–polymerase chain reaction in lungs from all animals receiving Ang-1 gene therapy. Tie-2 receptor expression was markedly downregulated in rats treated with MCT, and this was partially restored by gene therapy with Ang-1. Animals receiving MCT exhibited 77% mortality by 28 days. In contrast, in pAng-1–treated animals, the 28-day mortality was only 14% (
P
<0.0001). In addition, right ventricular systolic pressure was reduced from 52±1.3 mm Hg in the MCT-treated group to 38±1.3 mm Hg by Ang-1 gene transfer (
P
<0.01), whereas the measurement of right to left ventricular plus septal weight ratio was also reduced from 0.41±0.03 to 0.31±0.01 (
P
<0.05). Moreover, MCT resulted in increased apoptosis, mainly in the microvasculature, and reduced endothelial NO synthase mRNA expression, both of which were prevented by Ang-1 gene transfer. Thus, cell-based gene transfer with Ang-1 improved survival and pulmonary hemodynamics in experimental pulmonary hypertension by a mechanism involving the inhibition of apoptosis and protection of the pulmonary microvasculature.
Signal Transduction and Ca
2+
Signaling in Contractile Regulation Induced by Crosstalk Between Endothelin-1 and Norepinephrine in Dog Ventricular Myocardium
Authors: Chu Li , Takahashi Reiko , Norota Ikuo , Miyamoto Takuya , Takeishi Yasuchika , Ishii Kuniaki , Kubota Isao , Endoh Masao
Published: May 2003

In certain cardiovascular disorders, such as congestive heart failure and ischemic heart disease, several endogenous regulators, including norepinephrine (NE) and endothelin-1 (ET-1), are released from various types of cell. Because plasma levels of these regulators are elevated, it seems likely that cardiac contraction might be regulated by crosstalk among these endogenous regulators. We studied the regulation of cardiac contractile function by crosstalk between ET-1 and NE and its relationship to Ca
2+
signaling in canine ventricular myocardium. ET-1 alone did not affect the contractile function. However, in the presence of NE at subthreshold concentrations (0.1 to 1 nmol/L), ET-1 had a positive inotropic effect (PIE). In the presence of NE at higher concentrations (100 to 1000 nmol/L), ET-1 had a negative inotropic effect. ET-1 had a biphasic inotropic effect in the presence of NE at an intermediate concentration (10 nmol/L). The PIE of ET-1 was associated with an increase in myofilament sensitivity to Ca
2+
ions and a small increase in Ca
2+
transients, which required the simultaneous activation of protein kinase A (PKA) and PKC. ET-1 elicited translocation of PKCε from cytosolic to membranous fraction, which was inhibited by the PKC inhibitor GF 109203X. Whereas the Na
+
-H
+
exchange inhibitor Hoe 642 suppressed partially the PIE of ET-1, detectable alteration of pH
i
did not occur during application of ET-1 and NE. The negative inotropic effect of ET-1 was associated with a pronounced decrease in Ca
2+
transients, which was mediated by pertussis toxin-sensitive G proteins, activation of protein kinase G, and phosphatases. When the inhibitory pathway was suppressed, ET-1 had a PIE even in the absence of NE. Our results indicate that the myocardial contractility is regulated either positively or negatively by crosstalk between ET-1 and NE through different signaling pathways whose activation depends on the concentration of NE in the dog.
Role of Redox Signaling in the Autonomous Proliferative Response of Endothelial Cells to Hypoxia
Authors: Schäfer M. , Schäfer C. , Ewald N. , Piper H.M. , Noll Th.
Published: May 2003

Endothelial cells exhibit an autonomous proliferative response to hypoxia, independent of paracrine effectors. In cultured endothelial cells of porcine aorta, we analyzed the signaling of this response, with a focus on the roles of redox signaling and the MEK/ERK pathway. Transient hypoxia (1 hour) stimulated proliferation by 61±4% (n=16;
P
<0.05 versus control), quantified after 24 hours normoxic postincubation. Hypoxia induced an activation of ERK2 and of NAD(P)H oxidase and a burst of reactive oxygen species (ROS), determined by DCF fluorescence. To inhibit the MEK/ERK pathway, we used PD 98059 (PD, 20 μmol/L); to downregulate NAD(P)H oxidase, we applied p22
phox
antisense oligonucleotides; and to inhibit mitochondrial ROS generation, we used the ubiquinone derivate mitoQ (MQ, 10 μmol/L). All three inhibitions suppressed the proliferative response: PD inhibited NAD(P)H oxidase activation; p22
phox
antisense transfection did not inhibit ERK2 activation, but suppressed ROS production; and MQ inhibited ERK2 activation and ROS production. The autonomous proliferative response depends on the MEK/ERK pathway and redox signaling steps upstream and downstream of ERK. Located upstream is ROS generation by mitochondria, downstream is NAD(P)H oxidase.
Identification of a Nuclear Orphan Receptor (Ear2) as a Negative Regulator of Renin Gene Transcription
Authors: Liu Xuebo , Huang Xiaodong , Sigmund Curt D.
Published: May 2003

A potent transcriptional enhancer was previously identified upstream of the mouse renin gene. Within the enhancer is a TGACCT direct-repeat motif, required for enhancer activity, that is the consensus sequence recognized by members of the thyroid hormone subfamily of steroid hormone receptors. We previously reported that RAR/RXR bind to this sequence and mediate the induction of renin promoter activity by retinoids. However, gel mobility shift assays clearly show that other as yet unidentified factors also bind to this motif. In order to identify some of these TGACCT binding factors, we screened a yeast one-hybrid cDNA library derived from mouse As4.1 cells. One of these encoded the orphan nuclear receptor Ear2. Recombinant Ear2 was purified from
Escherichia coli
and an antipeptide antisera was generated. EMSA showed that purified recombinant Ear2 specifically binds the TGACCT direct-repeat motif. Transfection assays showed that Ear2 potently decreases both baseline and retinoid-induced mouse renin promoter activity in a dose-dependent, enhancer-dependent, and sequence-specific manner. Mutations in Ear2, which abolish its binding to the TGACCT motif, also abolish transcriptional repression. Ear2 was identified as a nuclear protein in As4.1 cells, is one of the proteins binding to the TGACCT repeat motif, and its overexpression can repress transcription of the endogenous renin gene in As4.1 cells. These data suggest that Ear2 is a negative modulator of renin gene transcription in As4.1 cells, and that the renin enhancer may actually encode a complex positive and negative regulator of transcription.
Genome Informatics
Authors: Winslow Raimond L. , Boguski Mark S.
Published: May 2003

This article reviews recent advances in genomics and informatics relevant to cardiovascular research. In particular, we review the status of (1) whole genome sequencing efforts in human, mouse, rat, zebrafish, and dog; (2) the development of data mining and analysis tools; (3) the launching of the National Heart, Lung, and Blood Institute Programs for Genomics Applications and Proteomics Initiative; (4) efforts to characterize the cardiac transcriptome and proteome; and (5) the current status of computational modeling of the cardiac myocyte. In each instance, we provide links to relevant sources of information on the World Wide Web and critical appraisals of the promises and the challenges of an expanding and diverse information landscape.
New wine in old bottles: the WHO ICF as an explanatory model of human behaviour
Authors: Wade Derick T , Halligan Peter
Published: May 2003

The World Health Organization's International Classification of Functioning (WHO ICF) is a good but incomplete framework for describing the situation of someone with long-term ill health. Several deficiencies exist for which improvements are suggested. The WHO needs to integrate the ICF with the ICD-10 to form a comprehensive system of classification of illness. Words are needed for normality at the level of organ and person, and the words ‘histology’ and ‘physiology’, and ‘anatomy’ and ‘capacity’ are suggested for the two levels respectively. A fourth context, that of time, is needed to understand fully a person's situation. The classification framework needs to take more account of the patient. It needs to recognize two separate perspectives, that of the subject and that of external observers and it needs to recognize two other specific person-centred phenomena: free will and quality of life. With changes and additions to take account of these deficiencies, the WHO ICF can be used as a powerful analytic and explanatory model of human experience and behaviour in any situation, not only in illness and disease.
A randomized controlled trial of the effects of intensive sit-to-stand training after recent traumatic brain injury on sit-to-stand performance
Authors: Canning Colleen G , Shepherd Roberta B , Carr Janet H , Alison Jennifer A , Wade Lauren , White Alanna
Published: May 2003

Objective: To examine the effectiveness of intensive practice of sit-to-stand on motor performance, exercise capacity and exercise efficiency in traumatic brain-injured patients during early inpatient rehabilitation.

Design: Single-blind randomized controlled pilot study.

Setting: Brain injury rehabilitation unit.

Subjects: Twenty-four subjects who had recently sustained a severe traumatic brain injury (TBI) were randomized into an experimental ( n = 13) and a control ( n = 11) group.

Interventions: In addition to their usual rehabilitation programme, subjects in the experimental group participated in four weeks of intensive training of sit-to-stand and step-up exercises with the aim of improving performance of sit-to-stand. The control group did no additional sit-to-stand or step-up training.

Main outcome measures: Total number of sit-to-stands in 3 min as a measure of motor performance; peak oxygen consumption during a maximal 3-min sit-to-stand test ( VO2peak) as a measure of exercise capacity; oxygen consumption during a 3-min equivalent workload sit-to-stand test ( VO2equiv) as a measure of exercise efficiency. Pre- and post-training measurements were made.

Results: The exercise programme resulted in a 62% improvement in motor performance (number of repetitions of sit-to-stand in 3 min) for the experimental group compared with the control group's 18% improvement ( p < 0.05). There was no significant difference between groups for changes in exercise capacity or efficiency. In the experimental group, the increase in VO2peak from pre-test to post-test correlated with the increase in sit-to-stand repetitions ( p < 0.05).

Conclusions: Intensive task-specific training is recommended as an important component of rehabilitation early following severe traumatic brain injury.
Effects of an ankle-foot orthosis on spatiotemporal parameters and energy cost of hemiparetic gait
Authors: Franceschini Marco , Massucci Maurizio , Ferrari Luciana , Agosti Maurizio , Paroli Chiara
Published: May 2003

Objective: To assess the effect of an ankle-foot orthosis on the gait and energy parameters of walking in chronic hemiparetic subjects.

Design: With/without group comparison.

Setting: Consecutive patients recruited from the gait analysis laboratory of our rehabilitation department.

Subjects: A group of nine chronic hemiparetic patients, with the same gait pattern alteration, were evaluated during walking at free speed with and without the use of an orthosis.

Outcome measures: Gait analysis and study of energy cost.

Results and conclusion: The orthosis significantly improved self-selected speed (15.47 versus 21.39 m/min), stride cycle (2.33 versus 2.08 s), stance (1.83 versus 1.48 s) and double support (1.55 versus 1.16 s) and reduced energy cost (0.76 versus 0.49 ml O2kg/m) of walking without affecting cardiorespiratory response. Moreover, a significant correlation was found between the improvement of double support and the reduction of energy cost.
The Adult Memory and Information Processing Battery (AMIPB) test of information-processing speed: a study of its reliability and feasibility in patients with multiple sclerosis
Authors: Vlaar A M M , Wade D T
Published: May 2003

Objective: To investigate how useful the Adult Memory and Information Processing Battery Task A (AMIPB) is as a test of the speed of information processing in patients with multiple sclerosis (MS) by comparing various methods of presenting the test and assessing the reliability (test–retest and inter-rater) and utility of each version.

Design: Each patient was assessed twice verbally by the same assessor 1–2 weeks apart. Then 1–2 weeks later half were assessed by another observer, and half were assessed by the first observer using a written method.

Setting: A specialist young disabled unit.

Subjects: Thirty-three patients with MS.

Measures: The AMIPB, the Short Memory-Orientation-Concentration Test (SOMC) and the Barthel ADL Index.

Results: The average (SD) number of correct responses after 4 min was 23.3 (18.6), median 21. The test–retest reliability ( n = 24) of the 4-min AMIPB was high ( r = 0.98) and the difference of the score ranged from –7 to 9: median 3, mean (SD) 1.88 (4.01) and interquartile range 0 to 3.25. The inter-observer reliability ( n = 12) of the 4-min AMIPB was also high ( r = 0.97) and the mean (SD) differences between scores were 4.3 (5.8), median 4, range +19 to –2. The score at 60 seconds and the score at 240 seconds were highly correlated ( r = 0.98). The scores obtained verbally and by writing were closely correlated ( r = 0.99).

Conclusions: The AMIPB used over 120 seconds with verbal responses is a reliable and reasonable test for major information-processing deficits.
The validity of patient and physician estimates of walking distance
Authors: Giantomaso Tony , Makowsky Lesia , Ashworth Nigel L , Sankaran Rajini
Published: May 2003

Objective: To establish the validity of patient and physician estimates of maximum walking distance versus actual measured maximum walking distance.

Design: Assessment of concurrent validity (patient and physician estimates were compared with a gold standard measure at the same time).

Setting: University-affiliated rehabilitation department in a tertiary care hospital.

Subjects: A sequential sample of 31 patients over the age of 17 referred to the physical medicine and rehabilitation outpatients department between 1 May 2000 and 20 July 2001, who had at least some degree of walking difficulty.

Interventions: Patients and their physicians were asked to provide estimates of walking distance independently after a regular appointment prior to the patient being escorted along a pre-measured walking course.

Main outcome measures: Actual distance walked was compared with estimates using Pearson correlation coefficients.

Results: Pearson correlation coefficients for patient estimate versus actual was 0.789 ( p ≤ 0.0001), and mean estimate of patient and physician estimates versus actual was 0.812 ( p ≤ 0.0001). Physician estimate versus actual and patient estimate versus physician estimate were 0.349 and -0.139 (neither significant). Sixty-seven per cent (20/30) of patients overestimated how far they thought they could walk versus 23% (7.30) of physicians who overestimated. Neither group were found to be ‘good’ estimators of maximal walking distance.

Conclusions: Neither patients nor physicians provide valid estimates of maximal walking distance. Patients consistently overestimate their maximal walking distance, whereas physicians tend to underestimate. Interestingly, patients' estimates (although over inflated) do correlate well with actual walking distance, while physician estimates are not at all correlated. This study suggests that reliance on self-reported or physician-estimated maximum walking distances (whether for clinical, research or other reasons) is potentially flawed.
Emotional well-being of close relatives to stroke survivors
Authors: Wyller Torgeir Bruun , Thommessen Bente , Sødring Karen Margrethe , Sveen Unni , Pettersen Anne Marie , Bautz-Holter Erik , Laake Knut
Published: May 2003

Objective: To compare the well-being of stroke patients' relatives with that of a reference group, and to identify variables related to the well-being of the relatives.

Design: Cross-sectional study.

Setting: Outpatient hospital department and patients' and relatives' own homes.

Subjects: Fifty-four patients one year after a stroke and their closest relatives. A reference population consisted of 419 elderly people drawn at random from the census files.

Outcome measures: Emotional well-being was assessed with the General Health Questionnaire (GHQ-20), and the perceived burden attributed to the care of the patient with the Caregiver Strain Index (CSI). The personal and instrumental activities of daily life (PADL and IADL), motor and cognitive functions of the patients were assessed with standardized tests.

Results: The relatives rated their well-being lower than the reference group rated theirs, the odds ratio (OR) being 5.6 (95% confidence interval (CI) 3.1–10) adjusted for age and gender. No association was found between the relatives' well-being and the motor, cognitive, PADL, IADL or other characteristics of the patients. Strong relationships were found between the CSI and the GHQ scores of the relatives, the OR (95% CI) for a poor GHQ score being 2.4 (1.6–3.7) for each unit increase in CSI, adjusted for gender.

Conclusions: Emotional well-being is influenced when a close relative gets a stroke. This seems to relate more strongly to the perceived burden of care than to objective characteristics of the patient.
Life satisfaction several years after severe multiple trauma – a retrospective investigation
Authors: Anke Audny GW , Fugl-Meyer Axel R
Published: May 2003

Objectives: To describe the prevalence of self-reported changes in life satisfaction after multiple trauma, to analyse associations between satisfaction with life as a whole and with domains in life, and to identify important contributors for satisfaction with life.

Design: Retrospective follow-up study.

Setting: Rehabilitation hospital three years after multiple trauma.

Subjects: Sixty-nine subjects with severe multiple trauma (ISS 3 16).

Main outcome measures: Clinical examinations to reveal prevalences of impairments and disabilities. Questionnaires about satisfaction with life as a whole and eight domains of life, both for the time before trauma, and for the actual situation; sense of coherence (SOC-13); social network.

Results: A total of 87% experienced a decrease in at least one of the nine life satisfaction items from before to after trauma (six-graded scale). After trauma significantly fewer subjects reported to be satisfied5–6 with life as a whole, as well as the domains sexual life, ADL, contact with friends, leisure, vocational and financial situation. Satisfaction with family life and partner relationship did not decrease significantly. The most important domains after trauma were satisfaction with leisure, family life and vocation. Vocational and leisure disability after trauma were important determinants for satisfaction with life as a whole. A strong sense of coherence and sufficient social network quality had significant impact on satisfaction with life as a whole and some of the domain-specific satisfactions.

Conclusions: Both personal resources (a strong sense of coherence) and the presence of a qualitatively sufficient social network can buffer the negative influence of disabilities on life satisfaction after trauma.
Is sense of coherence stable after multiple trauma?
Authors: Snekkevik Hildegun , Anke Audny GW , Stanghelle Johan K , Fugl-Meyer Axel R
Published: May 2003

Objectives: To explore whether sense of coherence (SOC) is stable over time after multiple trauma. The associations between SOC and satisfaction with life as a whole, as well as aspects of psychological well-being, were explored. Finally, an overriding aim was to assess whether SOC has long-term prognostic value for global life satisfaction or psychological well-being.

Design: Prospective study.

Setting: Sunnaas Rehabilitation Hospital.

Subjects: Twenty-six subjects with severe multiple trauma, without neuropsychological deficits.

Main outcome measures: Questionnaires that were answered at admission, at discharge and at follow-up 1–3 years after trauma were: Sense of Coherence Scale 13 items (SOC-13), satisfaction with life as a whole, General Health Questionnaire 20 items (GHQ-20), Hospital Anxiety and Depression Scale (HAD).

Results: While median SOC scores were fairly stable, individual scores were not stable over time, and for some subjects showed large variations. SOC score had neither long-term prognostic value for satisfaction with life as a whole nor for psychological well-being, at least not in the first years after severe multiple trauma. However, SOC was closely associated with overall life satisfaction when measured simultaneously. Furthermore, a weak SOC correlated with scores on psychological distress, anxiety and depression. SOC scores were also significantly related to being or not being in a state of anxiety, but not to being or not being depressed. Global life satisfaction was considerably reduced from before trauma (reported at admission) to the time of follow-up.

Conclusion: SOC was not stable over time after severe multiple trauma. SOC measured at admission could neither predict future satisfaction with life as a whole nor future psychological well-being. Measured simultaneously, overall life satisfaction and occurrence of anxiety were significantly associated with SOC.
Risk perception of developing complex regional pain syndrome I
Authors: Dijkstra P U , van der Schans C P , Geertzen J HB
Published: May 2003

This study investigated how members of a hand team perceive clinical signs after a fracture of the distal radius. The risk of developing complex regional pain syndrome I (CRPS-I) was assessed on a 100-mm straight line based on clinical signs 5 weeks, 7 weeks and 10 weeks after the accident. Members of the hand team perceived clinical signs significantly differently.
Wheelchair skills tests: a systematic review
Authors: Kilkens Olga JE , Post Marcel WM , Dallmeijer Annet J , Seelen Henk AM , van der Woude Lucas HV
Published: May 2003

Objective: To describe and compare the content, feasibility, outcome parameters, and clinimetric properties of the manual wheelchair skills tests reported in the literature.

Design: A systematic literature search was conducted in MEDLINE, EMBASE, PsychINFO and Current Contents. Tests were selected if they were observational tests, designed for subjects using hand-rim wheelchairs and were intended to assess wheelchair skill performance at the activity level.

Results: The search resulted in 34 papers, in which 24 different wheelchair skills tests were described. The skill most frequently included was wheelchair propulsion, consecutively followed by transferring, negotiating kerbs, ascending slopes, traversing tracks, sprinting and performing a wheelie. The three most frequently used outcome parameters were task performance time, independency of task performance, and physical strain during skill performance. Sensitivity to change was evaluated in three tests, validity in 10 tests, and reliability in nine tests.

Conclusions: Many tests are applied to measure wheelchair skill performance using different tasks and outcome measures. This makes it difficult to compare study results. Consensus among researchers as to which skills must be included as well as to standardization of the use of measurement instruments will reduce this problem and will additionally lead to a better insight in the quality of tests.
Reliability of the Dutch Pediatric Evaluation of Disability Inventory (PEDI)
Authors: Wassenberg-Severijnen Jeltje E , Custers Jan WH , Hox Joop J , Vermeer Adri , Helders Paul JM
Published: May 2003

Objective: To evaluate the reliability of the Dutch version of the Pediatric Evaluation of Disability Inventory (PEDI), an instrument for measuring functional status (capability and performance in self-care, mobility and social function) of young children using parent interviews.

Design: Inter-interviewer reliability was studied after scoring audiotaped interviews by a second researcher. For test–retest reliability the same parent was interviewed twice within three weeks; in inter-respondent reliability both parents of a child were interviewed independently within a few days. On item level, percentage identical scores were computed, and on scale level intraclass correlation coefficients (ICC) and Cronbach's alphas were calculated.

Subjects: Parents of 63 nondisabled and 53 disabled (various diagnosis) children aged between 7 and 88 months were interviewed.

Results: On scale level, all ICCs were above 0.90 and Cronbach's alpha was 0.89 for the self-care domain, 0.74 for the mobility domain and 0.87 for the social function domain. On item level for the Functional Skills Scale, the mean percentage identical scores varied from 89 to 99, and for the Caregiver Assistance Scale from 54 to 90. Different scores between interviewers resulted partially from ambiguous interpretation of the item and/or the explanation.

Conclusions: Although small adaptations have to be made, the psychometric properties of the Dutch PEDI are found to be good.
Reliability and validity of the Canadian Occupat189ional Performance Measure in stroke patients
Authors: Cup E H C , Scholte op Reimer W J M , Thijssen M C E , van Kuyk-Minis M A H
Published: May 2003

Objective: To research test–retest reliability and discriminant validity of the Canadian Occupational Performance Measure (COPM), a client-centred outcome measure, in stroke patients.

Design: The COPM was administered twice with a mean interval of eight days (SD 2.5, range 5–16). On both occasions the patient identified a maximum of five problems in daily activities. The problems of both interviews were compared. The problems identified during the first COPM were rated by the patient on a performance and satisfaction rating scale on both occasions. The individually identified items with use of the client-centred COPM were compared with the fixed items of standardized measures (Barthel Index, Frenchay Activities Index, Stroke Adapted Sickness Impact Profile-30, Euroqol 5D and Rankin Scale).

Setting: Patients were interviewed at their place of residence.

Subjects: Twenty-six stroke patients participated, 11 men and 15 women, aged from 26 to 83 years (mean 68, SD 15). Twenty-four patients were six months, two patients were two months post stroke.

Results: Of the 115 problems identified during the first COPM, 64 (56%) were also identified the second time. Correlation coefficients for the scores were 0.89 ( p < 0.001) for performance and 0.88 ( p < 0.001) for satisfaction. Of the individual problems identified with the COPM, 25% or less were present in the standardized measures. Correlations between the scores on the COPM and the standardized measures were low and nonsignificant, while all standardized measures correlated significantly with each other.

Conclusions: Test–retest reliability of the COPM was moderate for the item pool but was good for the performance and satisfaction scores. Discriminant validity was confirmed. Many patient-unique problems identified with the COPM were not evaluated by standardized measures.
The influence of illness duration and level of consciousness on the treatment effect and complication rate of serial casting in patients with severe cerebral spasticity
Authors: Pohl Marcus , Mehrholz Jan , Rückriem Stefan
Published: May 2003

Objective: To compare the improvement and complication rates for serial casting in patients with shorter as opposed to longer illness duration, and in patients with lower as opposed to higher levels of consciousness.

Design: A retrospective case-comparison study.

Setting: A rehabilitation centre for adult persons with neurological disorders.

Subjects: Sixty-eight patients with cerebral spasticity of different aetiologies were treated with serial casting to relieve fixed contractures.

Intervention: Serial casting with either <90 days (group A, 36 joints, 24 patients) or 390 days (group B, 85 joints, 44 patients) duration of illness and either <12 (group 1, 49 joints, 25 patients) or 312 (group 2, 72 joints, 43 patients) Glasgow Coma Scale (GCS) scores.

Main outcome measures: Percentage of normal maximum range of motion (ROM) at the completion of casting and one month after discontinuation, and number of complications due to casting procedure.

Results: No differences in ROM improvement between duration groups ( F = 0.43, p = 0.51) and GCS groups ( F = 1.3, p = 0.26) were observed. Complications in serial casting were found in 25.0% in group A, in 10.6% in group B (chi-squared = 4.2, p = 0.042), in 24.5% in group 1, and in 8.3% in group 2 (chi-squared = 6.0, p = 0.014).

Conclusion: This study suggests that serial casting in patients with longer illness duration and higher levels of consciousness provides improvements in ROM comparable with an earlier treatment in patients with more impaired consciousness, but results in a lower occurrence of complications.
Holocene palaeoclimate records over Europe and the North Atlantic
Authors: Emeis Kay-Christian , Dawson Alastair G.
Published: May 2003

This Special Issue of The Holocene contains 16 research papers based on a symposium at the 11th International Meeting of the European Union of Geosciences held in Strasbourg in April 2001. The aim of the symposium was a state-of-the-art assessment of empirical studies of postglacial marine and terrestrial climatic archives and their integration with numerical climate models. This editorial places the individual papers in the broader context of natural climate variability and anthropogenic impacts on the global climate system, regional differences in climate between maritime and continental areas, and the need for an improved theoretical basis for understanding the underlying causes of environmental change. The focus of the Special Issue is the dynamic and relatively well-understood climate of the North Atlantic and the European realm, where, in relation to the steepest offshore temperature gradient on Earth, observational data are abundant and many recent advances have been made in climate reconstruction from proxy archives. The editorial also contains a summary and overview of the papers included in the four main sections of the Special Issue, which emphasize: (1) numerical modelling experiments; (2) models of glacier buildup and equilibrium-line altitude; (3) marine and terrestrial proxy records of climatic change; and (4) multiproxy palaeoenvironmental reconstruction of a Portuguese lagoonal system.
Eleven-year solar cycle variations in the atmosphere: observations, mechanisms and models
Authors: Labitzke K. , Matthes K.
Published: May 2003

The understanding of natural and anthropogenic climatic change is an important issue in recent studies. The influence of the Sun (11-year solar cycle) as a natural variability factor on the atmosphere is discussed. Statistical studies with observational data (NCEP/NCAR re-analyses) covering four solar cycles show high correlations between the 11 -year solar signal and meteorological parameters, e.g., the geopotential heights and temperatures, in the lower stratosphere and troposphere. Studies with general circulation models (GCM) have discussed the possibility of an indirect dynamical response to direct changes in solar irradiance and ozone in the stratosphere. A physical mechanism explaining the solar influence on the atmosphere is still missing. Part of the mechanism understood so far and ideas from model and observational studies are presented.
Simulating near-equilibrium climate and vegetation for 6000 cal. years BP
Authors: Mikolajewicz U. , Scholze M. , Voss R.
Published: May 2003

The response of a coupled atmosphere-ocean general circulation model to insolation representative of 6000 years ago has been studied with a set of 1000-year quasi-equilibrium simulations. Comparison with similar experiments with an uncoupled atmosphere general circulation model demonstrates the importance of an interactive ocean for the climate signal. The model simulates an intensification of the African and Asian monsoons and a warming at high northern latitudes with reduced sea ice. Data from the coupled climate model have been used to drive a dynamical vegetation model. The modelled response is a marked increase in vegetation cover in the Sahara and a poleward shift of vegetation zones in high northern latitudes.
Effects of mid-Holocene river runoff on the Arctic ocean/sea-ice system: a numerical model study
Authors: Prange Matthias , Lohmann Gerrit
Published: May 2003

Recent geological studies have revealed that the freshwater input to the Arctic Ocean was highly variable during the Holocene. In the present study, the influence of mid-Holocene river runoff on large-scale Arctic ocean/sea-ice dynamics is examined using a general circulation model. A palaeohydrological forcing for the time interval around 6 ka BP (14C timescale) is constructed by compiling data from the available literature. Keeping all other forcing fields and bottom topography of the ocean model at present-day values, the effect of a changed freshwater input to the Arctic Ocean is isolated. The model shows that freshwater supply is vitally important for the polar oceanic circulation. In particular, a close connection between Siberian river runoff and the path of the Transpolar Drift (TPD) is found. Consistent with palaeoceanographic findings of driftwood delivery to the Canadian Arctic Archipelago and Baffin Bay, the model results suggest that enhanced freshwater discharge during the mid-Holocene caused an eastward shift of the TPD with strengthened outflow through Fram Strait.