bluuebunny/crossref_metadata_2025 huggingface dataset:
Does the European Clinical Trials Directive really improve clinical trial approval time?
Authors: Lambers Heerspink Hiddo J. , Dobre Daniela , Hillege Hans L. , Grobbee Diederick E. , De Zeeuw Dick
Published: June 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• The European Union adopted the European Union Clinical Trials Directive in 2001 to facilitate clinical drug research within Europe.

• The European Clinical Trials Directive has raised concerns over increased costs and complex administrative procedures, but the impact on duration between submission of a clinical trial application and approval by regulatory authorities is unknown.

WHAT THIS STUDY ADDS

• The introduction of the European Union Clinical Trials Directive appears not to shorten the duration of regulatory procedures within Europe.

• Duration of regulatory approval procedures is shorter in the USA compared with Europe.

AIMS

To facilitate and improve clinical research within Europe, the European Union (EU) adopted in 2001 the Clinical Trials Directive (EUCTD). The aim of this study was to compare duration between submission of a clinical drug trial application and approval by regulatory authorities in EU countries regulated by EUCTD vs. EU countries regulated by local legislation and, second, to compare the duration of regulatory approval in Europe vs. the USA and Australia.

METHODS

Application for clinical drug trial initiation was submitted to the regulatory authorities of 14 European countries, to the USA and to Australia. In Europe, 10 countries were regulated by EUCTD and four by local legislation.

RESULTS

In Europe, the median duration of regulatory procedures was longer in EUCTD countries compared with countries following local legislation (75 vs. 59 days; P < 0.001). Five EUCTD countries had a time to approval of >60 days (maximum within EUCTD rules). The long duration of regulatory procedures was the consequence of (i) sequential instead of simultaneous submission of trial application to regulatory authorities, and (ii) involvement of local ethics committees in procedures that should be followed only by central ethics committees. The duration of regulatory procedures was similar in Australia (67 vs. 68 days, P = 0.388), but significantly shorter in the USA (67 vs. 15 days, P < 0.001).

CONCLUSIONS

In this early stage of implementation, EUCTD appears not to shorten the duration of regulatory procedures for clinical trial initiation. Furthermore, Europe lags behind the USA in speed of regulatory procedures.
Lamotrigine does not prolong QTc in a thorough QT/QTc study in healthy subjects
Authors: Dixon Ruth , Job Sarah , Oliver Ruth , Tompson Debra , Wright John G. , Maltby Kay , Lorch Ulrike , Taubel Jorg
Published: June 2008

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Drugs that inhibit the human cardiac delayed rectifier potassium current may lead to prolongation of the cardiac QT interval and are associated with a fatal, polymorphic, ventricular tachycardia known as torsades de pointes.

• Lamotrigine is indicated in the treatment of epilepsy and the prevention of mood episodes in patients with bipolar disorder.

• Lamotrigine inhibits the human cardiac delayed rectifier potassium current in vitro, and it has been hypothesized that QT prolongation may contribute to the risk of sudden unexpected death in epilepsy patients.

WHAT THIS STUDY ADDS

• This is the first reported thorough QT/QTc study with lamotrigine conducted to International Conference on Harmonization guidelines.

• The mean QTc interval was not prolonged by lamotrigine in healthy subjects, as assessed by the standard heart rate correction methods (Fridericia's and Bazett's).

• The in vitro inhibition of the delayed rectifier potassium current does not translate into an effect on QT in man.

AIM

To characterize the effects of lamotrigine on QT interval in healthy subjects.

METHODS

Healthy subjects received a single oral dose of moxifloxacin (400 mg) or placebo in crossover design, followed by a dose‐escalating regimen of lamotrigine (n = 76) over a 77‐day period, or matched placebo (n = 76). Blood samples were taken for determination of moxifloxacin and lamotrigine concentrations and digital 12‐lead ECGs were recorded. The relationships between individual QT values and respective individual moxifloxacin or lamotrigine concentrations were explored using population pharmacokinetic–pharmacodynamic (PK–PD) modelling.

RESULTS

Moxifloxacin was associated with a maximum mean increase from baseline in QTcF of 14.81 ms [90% confidence interval (CI) 13.50, 16.11] 2.5 h after dosing. Steady‐state exposure to lamotrigine (50, 150 or 200 mg b.d.) was not associated with an increase in QTc interval. Small reductions in QTcF (maximum mean difference from placebo −7.48 ms, 90% CI −10.49, −4.46) and small increases in heart rate (maximum mean difference from placebo 5.94 bpm, 90% CI 3.81, 8.06) were observed with lamotrigine 200 mg b.d. vs. placebo. No effect of lamotrigine on QRS duration or blood pressure was observed. No outliers with QTcF > 450 ms, or with an increase from baseline of >60 ms were observed in the lamotrigine group. PK–PD modelling indicated statistically significant decreases in individually corrected QT intervals for lamotrigine and statistically significant increases in individually corrected QT intervals for moxifloxacin over the concentration ranges studied.

CONCLUSIONS

Therapeutic doses of lamotrigine (50–200 mg b.d.) were not associated with QT prolongation in healthy subjects.
Frequency of contamination of coagulation factor concentrates with novel human parvovirus PARV4
Authors: SCHNEIDER B. , FRYER J. F. , OLDENBURG J. , BRACKMANN H.‐H. , BAYLIS S. A. , EIS‐HÜBINGER A. M.
Published: June 2008

Summary.  Human parvovirus, PARV4 was identified in a plasma sample from a patient presenting with symptoms resembling acute HIV infection. Further strains of PARV4 and those of a closely related variant virus, were identified in plasma pools used in the manufacture of blood derivatives. DNA sequence analysis of these strains demonstrated two distinct PARV4 genotypes. It has subsequently been proposed that transmission of PARV4 occurs by parenteral routes. To investigate the risk of contamination of plasma‐derived coagulation factor concentrates, we analysed 169 lots for PARV4 DNA by polymerase chain reaction. Positive samples were confirmed by nucleotide sequence analysis and quantification of the viral load. Twenty‐one lots, representing eight different products were administered until the beginning of the 1980s and were not virally inactivated. Two lots examined were used in 1997, and 146 lots representing 13 products had been administered between October 2000 and February 2003. PARV4 DNA was detected in 7(33%) of the formerly administered lots, in one lot used in 1997, and in 13(9%) recently used lots. PARV4 genotype 2 DNA was predominantly present in the older concentrates, whilst genotype 1 was found more frequently in recently used lots. In three lots, both PARV4 genotypes were detected. Viral loads ranged between <100 and 105.8 copies mL−1 of product, with higher viral loads in the older concentrates. The results show that PARV4 contamination can be detected in an appreciable proportion of clotting factor concentrates. Further studies are needed to determine whether or not PARV4 contamination of coagulation factors causes harm to the product recipients.
Effect of film and temperature on the sensory, microbiological and nutritional quality of minimally processed cauliflower
Authors: Simón Ana , González‐Fandos Elena , Rodríguez Domingo
Published: June 2008

The effect of atmosphere modification, generated using three different packaging films, on the quality of cauliflower minimally processed when stored at 4 or 8 °C for up 20 days was evaluated. The colour, texture, weight loss, sensory attributes, as well as microbial counts and sugars and ascorbic acid content were determined. The atmosphere generated with the perforated polyvinylchloride (PVC) film was hardly modified, whereas the other two films (non‐perforated PVC and polypropylene films) originated changes in CO2 and O2 levels during storage. The different packaging conditions and storage temperature influenced yellowing. An increase in shear force was observed. Weight losses were below 5%. Mesophiles and Pseudomonas counts were below 7 log CFU g−1, the populations being lower with film B and film C than with film A. Cauliflower maintained an acceptable appearance in all the films studied. Total sugars decreased about 27% after 20 days of storage, whereas ascorbic acid did not change.
Response surface methodology optimisation of immobilised Lactobacillus acidophilus banana puree fermentation
Authors: Tsen Jen‐Horng , Lin Yeu‐Pyng , King V. An‐Erl
Published: June 2008

Fermentation temperature (34–40 °C), total inoculum level (1%–3%, v/v) and peeled‐fruit‐to‐water ratio (12.5%–37.5%, w/v) were combined to study their effects on the fermentation of banana media by free and Ca‐alginate or κ‐carrageenan‐immobilised Lactobacillus acidophilus. A three‐variable and three‐level design method, analysed by response surface methodology (RSM), was used. These factors, except peeled‐fruit‐to‐water ratio, were found to be significantly effective on viable cell numbers and 1‐kestose (GF2) concentrations. Contour plots were generated using a graphing software package (Surfer Mapping System, Version 5.0; Golden Software Inc., Golden, CO, USA, 1994) based on fitted quadratic regression equations. Optimum conditions for the highest viable cell number and higher GF2 concentration were found to be around 35 °C fermentation temperature, 1.2% inoculum level and 25.0% peeled‐fruit‐to‐water ratio for Ca‐alginate immobilised cell fermentation, and around 39 °C fermentation temperature, 1.8% inoculum level and 25.0% peeled‐fruit‐to‐water ratio for κ‐carrageenan immobilised cell fermentation. For free cell fermentation, conditions for the highest viable cell number and higher GF2 concentration could not be obtained. The predicted optimum conditions of immobilised cell fermentation and the experimental values were consistent. This verified the adequacy of these predicted models. It was concluded that RSM was appropriate for the optimisation of banana puree fermentation using cell immobilised L. acidophilus, and products with better synbiotic effects could be obtained. The consumer palatability of the immobilised cell‐fermented banana puree was found to be acceptable.
Fasting Reduces KiSS‐1 Expression in the Anteroventral Periventricular Nucleus (AVPV): Effects of Fasting on the Expression of KiSS‐1 and Neuropeptide Y in the AVPV or Arcuate Nucleus of Female Rats
Authors: Kalamatianos T. , Grimshaw S. E. , Poorun R. , Hahn J. D. , Coen C. W.
Published: June 2008

Changes in metabolic state, such as those induced by fasting, have profound effects on reproduction. In rats, the time‐course over which fasting inhibits luteinising hormone (LH) release is reduced to 48 h by the presence of oestradiol‐17β (E2). Hypothalamic kisspeptin plays a key role in mediating the actions of E2 on gonadotrophin‐releasing hormone (GnRH) neurones, and thereby promotes LH release. KiSS‐1‐expressing neurones are found in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC). Extensive evidence implicates the AVPV in GnRH release and the ARC in energy balance. The latter nucleus also contains neurones that express neuropeptide Y (NPY), an orexigenic peptide implicated in GnRH control. To elucidate the involvement of kisspeptin and/or NPY in hypothalamic responses to fasting, their expression was quantified by in situ hybridisation histochemistry in ovariectomised rats, with or without E2 replacement, before and after 48 h of fasting. In the presence of E2, but not in its absence, the fasting suppressed plasma LH. In the AVPV, the low level of KiSS‐1 expression found in the absence of E2 was unaffected by fasting. By contrast, the elevated level found in the presence of E2 was suppressed by fasting. Independent of E2, fasting had no effect on KiSS‐1 expression in the ARC, but increased NPY expression at that site. The present study has identified the AVPV as a site at which KiSS‐1 expression can be influenced by fasting. The results suggest that inhibition of KiSS‐1 expression in the AVPV may be a significant factor in restraining the gonadotrophic axis in response to negative energy balance in the presence of oestrogen. The extent to which the concurrent rise in NPY expression in the ARC may contribute to the suppression of LH release by influencing AVPV kisspeptin neurones, directly or indirectly, or by actions independent of kisspeptin, remains to be established.
Population genetic structure, gene flow and sex‐biased dispersal in frillneck lizards (Chlamydosaurus kingii)
Authors: UJVARI BEATA , DOWTON MARK , MADSEN THOMAS
Published: June 2008

By using both mitochondrial and nuclear multiloci markers, we explored population genetic structure, gene flow and sex‐specific dispersal of frillneck lizards (Chlamydosaurus kingii) sampled at three locations, separated by 10 to 50 km, in a homogenous savannah woodland in tropical Australia. Apart from a recombinant lizard, the mitochondrial analyses revealed two nonoverlapping haplotypes/populations, while the nuclear markers showed that the frillneck lizards represented three separate clusters/populations. Due to the small population size of the mtDNA, fixation may occur via founder effects and/or drift. We therefore suggest that either of these two processes, or a combination of the two, are the most likely causes of the discordant results obtained from the mitochondrial and the nuclear markers. In contrast to the nonoverlapping mitochondrial haplotypes, in 12 out of 74 lizards, mixed nuclear genotypes were observed, hence revealing a limited nuclear gene flow. Although gene flow should ultimately result in a blending of the populations, we propose that the distinct nuclear population structure is maintained by frequent fires resulting in local bottlenecks, and concomitant spatial separation of the frillneck lizard populations. Limited mark–recapture data and the difference in distribution of the mitochondrial and nuclear markers suggest that the mixed nuclear genotypes were caused by juvenile male‐biased dispersal.
Activation of transcription initiation by Spx: formation of transcription complex and identification of a Cis‐acting element required for transcriptional activation
Authors: Reyes Dindo Y. , Zuber Peter
Published: June 2008

The Spx protein of Bacillus subtilis interacts with RNA polymerase (RNAP) to activate transcription initiation in response to thiol‐oxidative stress. Protein–DNA cross‐linking analysis of reactions containing RNAP, Spx and trxA (thioredoxin) or trxB (thioredoxin reductase) promoter DNA was undertaken to uncover the organization of the Spx‐activated transcription initiation complex. Spx induced contact between the RNAP σA subunit and the −10 promoter sequence of trxA and B, and contact of the ββ′ subunits with core promoter DNA. No Spx–DNA contact was detected. Spx mutants, SpxC10A and SpxG52R., or RNAP α C‐terminal domain mutants that impair productive Spx–RNAP interaction did not induce heightened σ and ββ′ contact with the core promoter. Deletion analysis and the activity of hybrid promoter constructs having upstream trxB DNA fused at positions −31, −36 and −41 of the srf (surfactin synthetase) promoter indicated that a cis‐acting site between −50 and −36 was required for Spx activity. Mutations at −43 and −44 of trxB abolished Spx‐dependent transcription and Spx‐induced cross‐linking between the σ subunit and the −10 region. These data are consistent with a model that Spx activation requires contact between the Spx/RNAP complex and upstream promoter DNA, which allows Spx‐induced engagement of the σ and large subunits with the core promoter.
From basic research to the bedside: efficacy of topical treatment with pseudocatalase PC‐KUS in 71 children with vitiligo
Authors: Schallreuter Karin U. , Krüger Christian , Würfel Brigitte A. , Panske Angela , Wood John M.
Published: June 2008

Background  The epidermal accumulation of hydrogen peroxide (H2O2) has been documented in vitiligo.

Aim  To assess the effect on disease cessation and repigmentation of the reduction/removal of H2O2 using low‐dose, narrow‐band, ultraviolet‐B (UV‐B)‐activated pseudocatalase PC‐KUS in 71 children with vitiligo.

Methods  This uncontrolled and retrospective study included 45 girls and 26 boys (mean age, 10.3 years) who applied topical PC‐KUS twice daily to the entire body surface without narrow‐band UV‐B dose increments. The affected body areas were documented by special photography at the first visit and after 8–12 months. The response was evaluated by two independent physicians as > 75% vs. < 75% total repigmentation of the face/neck, trunk, extremities, and hands/feet. Generalized (n = 61) and segmental (n = 10) vitiligo were evaluated as different entities. The effect of total‐body, low‐dose, narrow‐band UV‐B (0.15 mJ/cm2) monotherapy once daily without any increments and without application of PC‐KUS was tested over 6 months in 10 children with vitiligo vulgaris (mean age, 8.4 years).

Results  One hundred per cent cessation was observed in 70 of the 71 children. More than 75% repigmentation was achieved in 66 of 71 patients on the face/neck, 48 of 61 on the trunk, and 40 of 55 on the extremities; however, repigmentation on the hands/feet was disappointing (five of 53). The response was independent of skin color, age of onset, duration of disease, other demographic features, and previous treatments. The follow‐up after narrow‐band UV‐B monotherapy showed no significant repigmentation in all areas. Seven of 10 patients showed progression of their vitiligo.

Conclusion  A reduction in epidermal H2O2 using low‐dose, narrow‐band UV‐B‐activated pseudocatalase PC‐KUS is an effective treatment for childhood vitiligo which can be safely performed at home.
Comparison of the radiometric BACTEC 460 TB culture system and Löwenstein–Jensen medium for the isolation of mycobacteria in cutaneous tuberculosis and their drug susceptibility pattern
Authors: Aggarwal Puneet , Singal Archana , Bhattacharya Sambit Nath , Mishra Kiran
Published: June 2008

Background  Mycobacterial isolation from cutaneous tuberculosis on Löwenstein–Jensen (L–J) medium has been reported to be low. The radiometric BACTEC 460 TB culture system (BACTEC system) has shown better isolation rates in pulmonary tuberculosis. There has been a progressive increase in the prevalence of multidrug resistance in pulmonary tuberculosis, but similar studies are lacking for cutaneous tuberculosis. Therefore, this study was undertaken to compare mycobacterial isolation on conventional L–J medium vs. the BACTEC system, and to determine the prevalence of multidrug resistance in cutaneous tuberculosis.

Methods  Thirty‐five untreated, clinically diagnosed, and histopathologically documented patients with cutaneous tuberculosis constituted the study material. Lesional skin biopsy specimens were cultured on both L–J medium and the BACTEC system. The isolates obtained were identified and subjected to sensitivity to rifampicin, isoniazid, ethambutol, and streptomycin using the BACTEC system.

Results  Twenty‐six mycobacterial isolates were recovered from 35 patients. Nine isolates (25.7%) grew on L–J medium after a mean period of 31.5 days, and 22 (62.8%) on the BACTEC system in 17.3 days. All of the isolates were identified as Mycobacterium tuberculosis. Drug susceptibility testing demonstrated 12 isolates to be resistant, seven multidrug resistant.

Discussion  The BACTEC system demonstrated an improved mycobacterial isolation rate and substantially reduced detection time when compared with L–J medium. The combined isolation rate on both media was 74.3% (26/35), greater than that of either used separately. Drug resistance was observed in 46.2% of isolates.

Conclusion  Radiometric liquid culture medium together with conventional L–J medium may be recommended in practice to enable the institution of appropriate antituberculous therapy modifications in drug‐resistant cases of cutaneous tuberculosis.
The uptake of laparoscopic colorectal surgery in Great Britain and Ireland: a questionnaire survey of consultant members of the ACPGBI
Authors: Schwab K. E. , Dowson H. M. , Van Dellen J. , Marks C. G. , Rockall T. A.
Published: June 2008

Objective  The National Institute for Clinical Excellence (NICE) has recommended laparoscopic resection as an alternative to open surgery for patients with colorectal cancer. The aim of this study was to evaluate the current uptake of laparoscopic colorectal surgery in Great Britain and Ireland.

Method  A questionnaire was distributed to members of the Association of Coloproctology of Great Britain and Ireland (ACPGBI) regarding their current surgical practice. Results were analysed individually, by region, and nationwide.

Results  Information was received on 436 consultants (in 155 replies), of whom 233 (53%) perform laparoscopic colorectal procedures. During the previous year, 25% of colorectal resections were performed laparoscopically by the respondents. However, of those surgeons who were performing laparoscopic resections, only 30% performed more than half of all their resections laparoscopically. Right hemicolectomy, left‐sided resections, and rectopexy were the most frequently performed laparoscopic resections. There was an even distribution throughout the country of consultants performing laparoscopic resections (regional IQR 48–60%). The main reason for consultants not performing laparoscopic procedures was a lack of training or funding.

Conclusion  Laparoscopic colorectal surgery is being performed by more than half (53%) of colorectal consultants nationwide, although only a quarter of all procedures are being undertaken laparoscopically.
MEASURING SEGREGATION AT THE MICRO LEVEL: AN APPLICATION OF THE M MEASURE TO MULTI‐ETHNIC RESIDENTIAL NEIGHBOURHOODS IN AMSTERDAM
Authors: DEURLOO MARINUS C. , DE VOS SJOERD
Published: June 2008

A wide variety of segregation measures are used in scientific research. However, the usual measures are not suitable for use at micro‐geographical scale level, for example, to evaluate the magnitude of spatial attraction or separation between pairs of ethnic groups within multi‐ethnic residential neighbourhoods in Amsterdam. In this paper we examine the social importance of possessing such knowledge for these areas, we discuss the deficiencies of the usual segregation measures as regards this level of analysis, and we draw attention to a recently developed spatial segregation measure, the so‐called M measure, which does happen to be suitable for this goal. We apply the M measure to some of these residential neighbourhoods which existed in Amsterdam on 1 January 2003. The conclusion is that although neighbourhoods can have a very similar ethnic mix, the spatial attraction or avoidance between certain pairs of groups may be quite different between these neighbourhoods.
Life history and development ‐ a framework for understanding developmental plasticity in lower termites
Authors: Korb Judith , Hartfelder Klaus
Published: June 2008

Termites (Isoptera) are the phylogenetically oldest social insects, but in scientific research they have always stood in the shadow of the social Hymenoptera. Both groups of social insects evolved complex societies independently and hence, their different ancestry provided them with different life‐history preadaptations for social evolution. Termites, the ‘social cockroaches’, have a hemimetabolous mode of development and both sexes are diploid, while the social Hymenoptera belong to the holometabolous insects and have a haplodiploid mode of sex determination. Despite this apparent disparity it is interesting to ask whether termites and social Hymenoptera share common principles in their individual and social ontogenies and how these are related to the evolution of their respective social life histories. Such a comparison has, however, been much hampered by the developmental complexity of the termite caste system, as well as by an idiosyncratic terminology, which makes it difficult for non‐termitologists to access the literature.

Here, we provide a conceptual guide to termite terminology based on the highly flexible caste system of the “lower termites”. We summarise what is known about ultimate causes and underlying proximate mechanisms in the evolution and maintenance of termite sociality, and we try to embed the results and their discussion into general evolutionary theory and developmental biology. Finally, we speculate about fundamental factors that might have facilitated the unique evolution of complex societies in a diploid hemimetabolous insect taxon. This review also aims at a better integration of termites into general discussions on evolutionary and developmental biology, and it shows that the ecology of termites and their astounding phenotypic plasticity have a large yet still little explored potential to provide insights into elementary evo‐devo questions.
Insect thermal tolerance: what is the role of ontogeny, ageing and senescence?
Authors: Bowler Ken , Terblanche John S.
Published: June 2008

Temperature has dramatic evolutionary fitness consequences and is therefore a major factor determining the geographic distribution and abundance of ectotherms. However, the role that age might have on insect thermal tolerance is often overlooked in studies of behaviour, ecology, physiology and evolutionary biology. Here, we review the evidence for ontogenetic and ageing effects on traits of high‐ and low‐temperature tolerance in insects and show that these effects are typically pronounced for most taxa in which data are available. We therefore argue that basal thermal tolerance and acclimation responses (i.e. phenotypic plasticity) are strongly influenced by age and/or ontogeny and may confound studies of temperature responses if unaccounted for. We outline three alternative hypotheses which can be distinguished to propose why development affects thermal tolerance in insects. At present no studies have been undertaken to directly address these options. The implications of these age‐related changes in thermal biology are discussed and, most significantly, suggest that the temperature tolerance of insects should be defined within the age‐demographics of a particular population or species. Although we conclude that age is a source of variation that should be carefully controlled for in thermal biology, we also suggest that it can be used as a valuable tool for testing evolutionary theories of ageing and the cellular and genetic basis of thermal tolerance.
Neuropsychological outcome in adolescents/young adults with childhood ADHD: profiles of persisters, remitters and controls
Authors: Halperin Jeffrey M. , Trampush Joey W. , Miller Carlin J. , Marks David J. , Newcorn Jeffrey H.
Published: June 2008

Background:  This study examined neuropsychological functioning in a longitudinal sample of adolescents/young adults with attention deficit/hyperactivity disorder (ADHD) and controls as a function of the persistence of ADHD. We hypothesized that measures of executive processes would parallel adolescent clinical status, with ADHD‐persisters, but not remitters, differing significantly from controls. In contrast, persisters and remitters were hypothesized to perform similarly, and different from controls, on tasks requiring less effortful processing.

Methods:  Ninety‐eight participants diagnosed with ADHD in childhood were reevaluated approximately 10 years later. Eighty‐five never‐ADHD controls similar in age, IQ, and sex distribution served as a comparison group. Participants were administered a psychiatric interview and neuropsychological test battery.

Results:  Those with childhood ADHD demonstrated broad neuropsychological deficits relative to controls. When the group with childhood ADHD was subdivided based on adolescent ADHD status, compared to controls, both persisters and remitters showed deficient perceptual sensitivity and response variability, and increased ankle movements recorded by a solid‐state actigraph. Only persisters differed from controls on several measures of more effortful executive processes.

Conclusions:  Findings provide preliminary support to the hypothesis that ADHD is associated with early‐appearing and enduring subcortical dysfunction, while recovery over the course of development is associated with improvements in executive control functions.
Coupled Lu–Hf and Sm–Nd geochronology constrains garnet growth in ultra‐high‐pressure eclogites from the Dabie orogen
Authors: CHENG H. , KING R. L. , NAKAMURA E. , VERVOORT J. D. , ZHOU Z.
Published: June 2008

Ultra‐high‐pressure eclogites from the Dabie orogen that formed over a range in temperatures (∼600 to > 700 °C) have been investigated with combined Lu–Hf and Sm–Nd geochronology. Three eclogites, sampled from Zhujiachong, Huangzhen and Shima, yield Lu–Hf ages of 240.0 ± 5.0, 224.4 ± 1.9 and 230.8 ± 5.0 Ma and corresponding Sm–Nd ages of 222.5 ± 5.0, 217.6 ± 6.1 and 224.2 ± 2.1 Ma respectively. Well‐preserved prograde major‐ and trace‐element zoning in garnet in the Zhujiachong eclogite suggests that the Lu–Hf age mostly reflects an early phase of garnet growth that continued over a time interval of c. 17.5 Myr. For the Huangzhen eclogite, despite preserved elemental growth zoning in garnet, textural study reveals that the Lu–Hf age is biased towards a later garnet growth episode rather than representing early growth. The narrow time interval of <6.6 Myr defined by the difference between Lu–Hf and Sm–Nd ages indicates a short final garnet growth episode and suggests a rapid cooling stage. By contrast, the rather flat element zoning in garnet in the Shima eclogite suggests that Lu–Hf and Sm–Nd ages for this sample have been reset by diffusion and are cooling ages. The new Lu–Hf ages point to an initiation of prograde metamorphism prior to c. 240 Ma for the Dabie orogen, while the exact peak metamorphic timing experienced by specific samples ranges between c. 230 to c. 220 Ma.
Marginal Mark Regression Analysis of Recurrent Marked Point Process Data
Authors: French Benjamin , Heagerty Patrick J.
Published: June 2008

SummaryLongitudinal studies typically collect information on the timing of key clinical events and on specific characteristics that describe those events. Random variables that measure qualitative or quantitative aspects associated with the occurrence of an event are known as marks. Recurrent marked point process data consist of possibly recurrent events, with the mark (and possibly exposure) measured if and only if an event occurs. Analysis choices depend on which aspect of the data is of primary scientific interest. First, factors that influence the occurrence or timing of the event may be characterized using recurrent event analysis methods. Second, if there is more than one event per subject, then the association between exposure and the mark may be quantified using repeated measures regression methods. We detail assumptions required of any time‐dependent exposure process and the event time process to ensure that linear or generalized linear mixed models and generalized estimating equations provide valid estimates. We provide theoretical and empirical evidence that if these conditions are not satisfied, then an independence estimating equation should be used for consistent estimation of association. We conclude with the recommendation that analysts carefully explore both the exposure and event time processes prior to implementing a repeated measures analysis of recurrent marked point process data.
Proteomics analysis in post‐transplant lymphoproliferative disorders
Authors: Alsayed Yazan , Leleu Xavier , Leontovich Alexey , Oton Ana B. , Melhem Mona , George Diane , Ghobrial Irene M.
Published: June 2008

Little is known about the biology of post‐transplant lymphoproliferative disorders (PTLDs). The objective of this study was to determine the molecular alterations that occur at the protein level in patients with PTLDs. Six tumor samples from adult patients with PTLD and four benign lymph nodes were studied using protein microrarray technique. Proteins that were dysregulated included proteins in the PI3K/mTOR, NFkB and HSP90 pathways. Inhibitors of these proteins induced cytotoxicity and apoptosis in EBV+ve and –ve cell lines. These results provide insight into pathways that are dysregulated in PTLD and can be targeted in future clinical trials.
Pregnancy outcome in congenital dyserythropoietic anemia type I
Authors: Shalev Hanna , Perez Avraham Galit , Hershkovitz Reli , Levy Amalia , Sheiner Eyal , Levi Itai , Tamary Hannah
Published: June 2008

Objectives:  Congenital dyserythropoietic anemia type I (CDA I) is a rare inherited disease characterized by moderate to severe macrocytic anemia and abnormal erythroid precursors with nuclear chromatin bridges and spongy heterochromatin. Moderate to severe maternal anemia is a recognized independent risk factor for low birth weight (LBW) and complicated delivery. The aim of the study was to review the outcome of pregnancies in women with CDA I.

Methods:  The clinical and laboratory records of 28 spontaneous pregnancies in six Bedouin women with CDA I were reviewed. The results were compared with findings from a retrospective review of a large population‐based registry including all pregnancies in Bedouin women during the same 15‐yr period.

Results:  Eighteen pregnancies in women with CDA I (64%) were complicated. One pregnancy was aborted spontaneously in the first trimester and one resulted in a non‐viable fetus (stillborn at 26 wk). Cesarean section (CS) was performed in 10 pregnancies (36%). Eleven of the 26 newborns (42%) had a LBW: six were born prematurely and five were small for gestational age. The odds ratio for CS in women with CDA I compared with healthy Bedouin women was 4.5 [95% confidence interval (CI) 1.2–10.3], and for a LBW infant, 5.5 (95% CI 2.4–12.3). Careful follow‐up was associated with significantly better fetal outcome (P = 0.05).

Conclusions:  Pregnancies in women with CDA I are at high risk for delivery‐related and outcome complications. To improve fetal outcome, women with CDA I should be carefully monitored during pregnancy.
Stretching modulates oxytalan fibers in human periodontal ligament cells
Authors: Tsuruga E. , Nakashima K. , Ishikawa H. , Yajima T. , Sawa Y.
Published: June 2008

Background and Objective:  Oxytalan fibers, as well as collagen fibers, are the structural components of periodontal ligaments. Periodontal ligaments are continuously exposed to various functional forces. However, the behavior of oxytalan fibers under mechanical strain has not been investigated. We hypothesized that strain would alter the amount and appearance of oxytalan fibers in terms of positivity for their major components, fibrillin‐1 and fibrillin‐2.

Material and Methods:  We subjected periodontal ligament fibroblasts to stretching strain to examine the effects on their formation of oxytalan fibers in cell/matrix layers.

Results:  Stretching increased the levels of fibrillin‐1 and fibrillin‐2 by 25% relative to the control, but did not affect the gene expression level of either type of fibrillin. Immunofluorescence and immunogold electron microscopy analysis revealed that bundles of oxytalan fibers became thicker under stretching conditions.

Conclusion:  These results suggest that tension strain functionally regulates microfibril assembly in periodontal ligament fibroblasts and thus may contribute to the homeostasis of oxytalan fibers in periodontal ligaments.
Melatonin is able to prevent the liver of old castrated female rats from oxidative and pro‐inflammatory damage
Authors: Kireev R. A. , Tresguerres A. C. F. , Garcia C. , Ariznavarreta C. , Vara E. , Tresguerres Jesus A. F.
Published: June 2008

Abstract:  The aim of this study was to investigate the effect of aging and ovariectomy on various physiological parameters related to inflammation and oxidative stress in livers obtained from old female rats, and the influence of chronic administration of melatonin on these animals. Twenty‐four female Wistar rats of 22 months of age were used. Animals were divided into four experimental groups: two intact groups that were untreated or given melatonin (1 mg/kg/day), and two ovariectomized groups that also untreated and treated with melatonin (1 mg/kg/day). After 10 wk of treatment, rats were sacrificed by decapitation, and livers were collected and homogenized. A group of 2‐month‐old female rats was used as young controls. Protein expression of inducible nitric oxide synthase (iNOS), heme oxygenase‐1 (HO‐1), IL‐6, TNF‐α and IL‐1β were determined by Western blot analysis. The levels of nitric oxide metabolites (NOx), lipid hydroperoxide (LPO), TNF‐α, IL‐1β, IL‐6 and IL‐10 were determined. Levels of LPO in the liver homogenates as well as iNOS protein expression and NOx levels were increased in old rats as compared with young animals; this effect was more evident in ovariectomized animals. Pro‐inflammatory cytokines TNF‐α, IL‐1β and IL‐6 were significantly increased and anti‐inflammatory IL‐10 decreased during aging and after ovariectomy. Aging also significantly increased the expression of HO‐1 protein, and ovariectomized rats showed an additional increase. Administration of melatonin, both to intact and to the ovariectomized animals significantly reduced NOx, LPO levels and pro‐inflammatory cytokines in the liver as compared with untreated rats. Significant rice in IL‐10 and reductions in the iNOS, HO‐1, IL‐6, TNF‐α and IL‐1β protein expression were also found in rats treated with melatonin. Oxidative stress and inflammation induced during aging in the liver are more marked in castrated than in intact females. Administration of melatonin reduces both these situations.
Effect of ionic strength and oxidation on the P‐loop conformation of the protein tyrosine phosphatase‐like phytase, PhyAsr
Authors: Gruninger Robert J. , Selinger L. Brent , Mosimann Steven C.
Published: June 2008

The protein tyrosine phosphatase (PTP)‐like phytase, PhyAsr, from Selenomonas ruminantium is a novel member of the PTP superfamily, and the only described member that hydrolyzes myo‐inositol‐1,2,3,4,5,6‐hexakisphosphate. In addition to the unique substrate specificity of PhyAsr, the phosphate‐binding loop (P‐loop) has been reported to undergo a conformational change from an open (inactive) to a closed (active) conformation upon ligand binding at low ionic strength. At high ionic strengths, the P‐loop was observed in the closed, active conformation in both the presence and absence of ligand. To test whether the P‐loop movement can be induced by changes in ionic strength, we examined the effect that ionic strength has on the catalytic efficiency of PhyAsr, and determined the structure of the enzyme at several ionic strengths. The catalytic efficiency of PhyAsr is highly sensitive to ionic strength, with a seven‐fold increase in kcat/Km and a ninefold decrease in Km when the ionic strength is increased from 100 to 500 mm. Surprisingly, the P‐loop is observed in the catalytically competent conformation at all ionic strengths, despite the absence of a ligand. Here we provide structural evidence that the ionic strength dependence of PhyAsr and the conformational change in the P‐loop are not linked. Furthermore, we demonstrate that the previously reported P‐loop conformational change is a result of irreversible oxidation of the active site thiolate. Finally, we rationalize the observed P‐loop conformational changes observed in all oxidized PTP structures.
Isolation and characterization of a novel glycosyltransferase that converts phloretin to phlorizin, a potent antioxidant in apple
Authors: Jugdé Hélène , Nguy Danny , Moller Isabel , Cooney Janine M. , Atkinson Ross G.
Published: June 2008

The dihydrochalcone phlorizin (phloretin 2′‐glucoside) contributes to the flavor, color and health benefits of apple fruit and processed products. A genomics approach was used to identify the gene MdPGT1 in apple (Malus x domestica) with homology to the UDP‐glycosyltransferase 88 family of uridine diphosphate glycosyltransferases that show specificity towards flavonoid substrates. Expressed sequence tags for MdPGT1 were found in all tissues known to produce phlorizin including leaf, flower and fruit. However, the highest expression was measured by quantitative PCR in apple root tissue. The recombinant MdPGT1 enzyme expressed in Escherichia coli glycosylated phloretin in the presence of [3H]‐UDP‐glucose, but not other apple antioxidants, including quercetin, naringenin and cyanidin. The product of phloretin and UDP‐glucose co‐migrated with an authentic phlorizin standard. LC/MS indicated that MdPGT1 could glycosylate phloretin in the presence of three sugar donors: UDP‐glucose, UDP‐xylose and UDP‐galactose. This is the first report of functional characterization of a UDP‐glycosyltransferase that utilizes a dihydrochalcone as its primary substrate.
Secretion of bacteriolytic endopeptidase L5 of Lysobacter sp. XL1 into the medium by means of outer membrane vesicles
Authors: Vasilyeva Natalia V. , Tsfasman Irina M. , Suzina Natalia E. , Stepnaya Olga A. , Kulaev Igor S.
Published: June 2008

The Gram‐negative bacterium Lysobacter sp. XL1 secretes various proteins, including bacteriolytic enzymes (L1–L5), into the culture medium. These proteins are able to degrade Gram‐positive bacteria. The mechanism of secretion of extracellular proteins by Lysobacter sp. XL1 has not been studied hitherto. Electron microscopic investigations revealed the phenomenon of the formation of extracellular vesicles by Lysobacter sp. XL1. These vesicles contained components of the Lysobacter sp. XL1 outer membrane, and demonstrated bacteriolytic activity against Gram‐positive and Gram‐negative bacteria: Staphylococcus aureus 209‐P and Erwinia marcescens EC1, respectively. Western blotting analysis with antibodies to homologous bacteriolytic endopeptidases L1 and L5 showed that endopeptidase L5 was secreted into the culture medium by means of vesicles, unlike its homolog, endopeptidase L1. When inside the vesicles, endopeptidase L5 actively lysed the Gram‐negative bacterium Erwinia marcescens; outside the vesicles, it lost this ability. The secretion of bacteriolytic endopeptidase L5 through the outer membrane vesicles is of great biological significance: because of this ability, Lysobacter sp. XL1 can compete in nature with both Gram‐positive and Gram‐negative bacteria.
The pH dependence of kinetic isotope effects in monoamine oxidase A indicates stabilization of the neutral amine in the enzyme–substrate complex
Authors: Dunn Rachel V. , Marshall Ker R. , Munro Andrew W. , Scrutton Nigel S.
Published: June 2008

A common feature of all the proposed mechanisms for monoamine oxidase is the initiation of catalysis with the deprotonated form of the amine substrate in the enzyme–substrate complex. However, recent steady‐state kinetic studies on the pH dependence of monoamine oxidase led to the suggestion that it is the protonated form of the amine substrate that binds to the enzyme. To investigate this further, the pH dependence of monoamine oxidase A was characterized by both steady‐state and stopped‐flow techniques with protiated and deuterated substrates. For all substrates used, there is a macroscopic ionization in the enzyme–substrate complex attributed to a deprotonation event required for optimal catalysis with a pKa of 7.4–8.4. In stopped‐flow assays, the pH dependence of the kinetic isotope effect decreases from approximately 13 to 8 with increasing pH, leading to assignment of this catalytically important deprotonation to that of the bound amine substrate. The acid limb of the bell‐shaped pH profile for the rate of flavin reduction over the substrate binding constant (kred/Ks, reporting on ionizations in the free enzyme and/or free substrate) is due to deprotonation of the free substrate, and the alkaline limb is due to unfavourable deprotonation of an unknown group on the enzyme at high pH. The pKa of the free amine is above 9.3 for all substrates, and is greatly perturbed (ΔpKa∼ 2) on binding to the enzyme active site. This perturbation of the substrate amine pKa on binding to the enzyme has been observed with other amine oxidases, and likely identifies a common mechanism for increasing the effective concentration of the neutral form of the substrate in the enzyme–substrate complex, thus enabling efficient functioning of these enzymes at physiologically relevant pH.
Patterns of morphometric variation in the alpine newt (Mesotriton alpestris) at the southern limit of its distribution: environmental correlates
Authors: SOTIROPOULOS Konstantinos , LEGAKIS Anastasios , POLYMENI Rosa Maria
Published: June 2008

We applied multivariate analyses to an array of body measures of alpine newt specimens derived from 11 local populations in Greece to describe, analyse and detect patterns and putative causes of within‐population and among‐population morphometric variation. The observed morphometric variation was partitioned into several independently varying aspects of the external phenotype, frequently following variation patterns in different environmental factors. The size and features of the aquatic habitat were found to affect body size, while altitude was found to affect head‐shape variation in both sexes. At the intra‐population level, variation in generalized body size and shape was found to be significantly lower when competitive newt species were present in the habitat, indicating stabilizing selection towards a decrease in inter‐specific competition. No clear discrimination on body size and shape proportions was detected between the two genetic lineages examined, implying ecogenetic or environmentally induced variation rather than phylogeny.
Sodic Pyroxene and Sodic Amphibole as Potential Reference Materials for In Situ Lithium Isotope Determinations by SIMS
Authors: Marks Michael A.W. , Rudnick Roberta L. , Ludwig Thomas , Marschall Horst , Zack Thomas , Halama Ralf , McDonough William F. , Rost Detlef , Wenzel Thomas , Vicenzi Edward P. , Savov Ivan P. , Altherr Rainer , Markl Gregor
Published: June 2008

Two large pegmatitic crystals of sodic pyroxene (aegirine) and sodic amphibole (arfvedsonite) from the agpaitic igneous Ilímaussaq Complex, south Greenland were found to be suitable as reference materials for in situ Li isotope determinations. Lithium concentrations determined by SIMS and micro‐drilled material analysed by MC‐ICP‐MS generally agreed within analytical uncertainty. The arfvedsonite crystal was homogeneous with [Li] = 639 ± 51 μg g−1 (2s, n = 69, MC‐ICP‐MS and SIMS results). The aegirine crystal shows strongly developed sector zoning, which is a common feature of aegirines. Using qualitative element mapping techniques (EPMA), the homogeneous core of the crystal was easily distinguished from the outermost sectors of the crystals. The core had a mean [Li] of 47.6 ± 3.6 μg g−1 (2s, n = 33) as determined by SIMS. The seven micro‐drilled regions measured by solution MC‐ICP‐MS returned slightly lower concentrations (41–46 μg g−1), but still overlap with the SIMS data within uncertainty. Based on MC‐ICP‐MS and SIMS analyses, the variation in δ7Li was about 1‰ in each of the two crystals, which is smaller than that in widely used glass reference materials, making these two samples suitable to serve as reference materials. There was, however, a significant offset between the results of MC‐ICP‐MS and SIMS. The latter deviated from the MC‐ICP‐MS results by −6.0 ± 1.9‰ (2s) for the amphibole and by −3.9 ± 1.9‰ (2s) for the aegirine. This indicates the presence of a significant matrix effect in SIMS determinations of Li isotopes for amphibole and pyroxene relative to the basalt glasses used for calibration. Based on the MC‐ICP‐MS results, mean δ7Li values of +0.7 ± 1.2‰ (2s, n = 10) for the arfvedsonite crystal and of −3.7 ± 1.2‰ (2s, n = 7) for the core of the aegirine crystal were calculated. Adopting these values, SIMS users can correct for the specific IMF (instrumental mass fractionation) of the ion probe used. We propose that these two crystals serve as reference materials for in situ Li isotope determinations by SIMS and pieces of these two crystals are available from the first author upon request.