bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of coping and socioeconomic factors on quality of life in adults with asthma
Authors: Adams Robert J. , Wilson David , Smith Brian J. , Ruffin Richard E.
Published: February 2004

Objective:  The socioeconomic variables of income, race and employment status have been shown to influence health‐related quality of life (HRQL) scores in persons with asthma. However, little is known about the impact of other psychological factors or perceptions of economic hardship on HRQL in asthma, despite the known influence these have on general activity levels and emotional perceptions. The aim of the present study was to assess the relationships between psychological and socioeconomic factors and HRQL and on subsequent changes to HRQL over 12 months.

Methodology:  Consecutive adult patients with moderate or severe asthma attending outpatient clinics, emergency departments or who were inpatients at two teaching hospitals, completed surveys of clinical status, psychological and socioeconomic variables, and HRQL instruments (SF‐36 and Modified Marks Asthma Quality of Life Questionnaire [MAQLQ‐M]), at baseline and over 12‐months follow‐up.

Results:  Of 343 eligible subjects, survey responses were received from 293 at baseline and 232 at 12‐months. Mean age was 42 years (SD 18), 67% were female, 42% had moderate, and 58% severe current asthma clinical status according to the National Asthma Education and Prevention Program guidelines criteria. In random‐effects multiple regression models, after adjusting for age, gender, education, income and hospital, significant independent variables associated with each of total MAQLQ‐M, SF‐36 Physical Component Summary (PCS) and SF‐36 Mental Component Summary (MCS) scores were avoidance coping, perceived recent financial difficulties and clinical asthma status. Additional independent associations were, for total MAQLQ‐M, patient concerns about costs delaying them from seeking care (overall model r2 = 0.69); for PCS, active coping (r2 = 0.69) and for MCS, positive evaluations/satisfaction with illness (r2 = 0.54).

Conclusion:  Psychological factors, particularly coping styles, need to be taken into account when considering HRQL scores as outcome measures in asthma. Interventions to improve the coping capabilities of individuals with moderate‐to‐severe asthma may be potentially important areas for improvement of asthma‐related HRQL.
Pathogenesis of pleural infection
Authors: Hage Chadi A. , Mohammed Kamal Abdul , Antony Veena B.
Published: February 2004

Abstract:  The pleura responds to the presence of infecting organisms with a vigorous inflammatory response associated with an exudation of white blood cells and proteins. The development and outcome of pleural infections is a function of a balance between the virulence of the invading microorganism and the immune reaction involving professional immune cells as well as the pleural mesothelial cells. Most commonly, pleural infection occurs after invasion through the lung parenchyma and a breach in the viscera pleura resulting in the formation of a parapneumonic process. Upon infection, the microorganisms are recognized by the pleural mesothelial cell, which remains the first line of defence. Pleural responses to infection include those of innate immunity as well as adaptive or acquired immunity. Innate and acquired immune responses are closely linked. In this review, we discuss the different virulence factors that allow microorganisms to infect the pleura and the role of the pleural mesothelial cells in bridging the innate and acquired immune responses.
The C : N : P stoichiometry of autotrophs – theory and observations
Authors: Ågren Göran I.
Published: February 2004

Evolution has set biochemical constraints on the chemical composition of living organisms. These constraints seem to lead to increases in N : C and P : C ratios with increasing relative growth rate for all types of organisms. The N : P ratio also seems to decrease with relative growth rate for heterotrophs whereas autotrophs may show a more complex behaviour. Here I will show that, from biochemical considerations, N : C should increase linearly and P : C quadratically with relative growth rate in autotrophs with the consequence that N : P increases at low relative growth rates, passes a maximum and then decreases at high relative growth rates. These predictions are verified against observations for a freshwater alga (Selenastrum minutum) and a tree seedling (Betula pendula). Changes in temperature, light or other factors that affect the growth rate of autotrophs interact with nutrient supply in such a way that there are no simple rules for as to how N : P will change.
Uses and abuses of fractal methodology in ecology
Authors: Halley J. M. , Hartley S. , Kallimanis A. S. , Kunin W. E. , Lennon J. J. , Sgardelis S. P.
Published: February 2004

Fractals have found widespread application in a range of scientific fields, including ecology. This rapid growth has produced substantial new insights, but has also spawned confusion and a host of methodological problems. In this paper, we review the value of fractal methods, in particular for applications to spatial ecology, and outline potential pitfalls. Methods for measuring fractals in nature and generating fractal patterns for use in modelling are surveyed. We stress the limitations and the strengths of fractal models. Strictly speaking, no ecological pattern can be truly fractal, but fractal methods may nonetheless provide the most efficient tool available for describing and predicting ecological patterns at multiple scales.
Species overlap, speciation and the evolution of aggregation pheromones in bark beetles
Authors: Symonds Matthew R. E. , Elgar Mark A.
Published: February 2004

Theoretical predictions suggest that species‐specific signals used in the attraction of mates should evolve to reduce the risk of mismating and hybridization. These predictions lead to the hypothesis that the signals of spatially overlapping (i.e. sympatric or syntopic) species should differ more substantially than those of non‐overlapping species. Earlier studies have tested this prediction for auditory and visual signals. Here we test the hypothesis using olfactory signals, specifically the aggregation pheromones of species from two genera of bark beetles, Dendroctonus and Ips. We found no direct evidence from within these genera regarding the fact that the chemical blends that make up these pheromones differ more substantially in species that overlap in their geographical ranges and/or host‐tree use than in allopatric taxa. However, when comparing between genera, the pheromones of overlapping species appear to be more similar than non‐overlapping species. We hypothesize that the species of host tree utilized by the beetles may have some influence on their pheromone blends. Additionally, within genera, species that overlap in host use tend to be more closely related than species that use different hosts. These results may provide indirect evidence for an effect of species overlap on the evolution of bark beetle pheromones.
Population genetics of transgene containment
Authors: Haygood Ralph , Ives Anthony R. , Andow David A.
Published: February 2004

Several strategies have been proposed for creating transgenic cultivars from which transgene escape to wild relatives would seem unlikely; for example, to impede escape through pollen, a transgene could be inserted into chloroplast DNA (cpDNA), which in many crops is rarely transmitted through pollen. None of these strategies would be failsafe; for example, the rate of cpDNA transmission through pollen may be low but non‐zero in many crops. Here, we study how the probability distribution of escape time depends on the rates of pollen and seed flow from the crop to wild populations, the number and sizes of the wild populations, the selection coefficient for the transgene, and a leakage parameter characteristic of the strategy, for example, the rate of cpDNA transmission through pollen. We find that even with a leakage parameter as small as 10−3, the probability of escape within as few as 10 generations could be appreciable.
A revision of the Afrotropical genus Dhatrichia (Trichoptera, Hydroptilidae)
Authors: Kjærandsen Jostein
Published: February 2004

Five previously described species of Dhatrichia Mosely, 1948 are recognized: D. inasa Mosely, 1948 from Yemen; D. bipunctata Statzner, 1977 from Zaire; D. lerabae (Gibon, Guenda & Coulibaly, 1994) comb. n. from Burkina Faso and Ghana; and D. cinyra Wells & Andersen, 1995 and D. divergenta Wells & Andersen, 1995 from Tanzania. A sixth species D. feredougoubae Gibon, 1987 from the Ivory Coast and Ghana is transferred to Microptila Ris, 1897 comb. n. In addition, nine new species are described and illustrated as males: D. ankasaensis sp. n., D. botiensis sp. n., D. hunukani sp. n., D. minuta sp. n., D. paraminuta sp. n. and D. wliensis sp. n. from Ghana, D. anderseni sp. n. from Tanzania, and D. madagascarensis sp. n. and D. giboni sp. n. from Madagascar. Females are associated, described and illustrated for all species, except D. inasa and D. giboni. The larvae and pupae of D. ankasaensis, D. hunukani, D. lerabae, D. minuta and D. wliensis are described and illustrated as the first known immatures of the genus. Keys to known larvae, pupae, males and females are provided. A phylogenetic analysis of the genus revealed four species groups. The most plesiomorphous taxa are West African, followed by East African and Malagasian taxa. A sister group relationship between the Eburneo–Ghanean and the Sudanian biogeographical regions is encountered twice. Among several possible sister taxa, the sister group turned out to be Kumanskiella Harris & Flint, 1992 and Microptila Ris, 1897 in part, combined. Implications for generic classification and biogeography are outlined. A morphometric principal component analysis revealed good separation of the sexes by the number and shape of antennal segments, and by eye size. Other measures are strongly dependent on overall size, and show best separation of females between species and species groups. A functional fit between male inferior appendages and secondary sexual characters in female sternite VIII is demonstrated for all species with associated females.
Australian and US interest rate swap markets: comparison and linkages
Authors: In Francis , Fang Victor , Brown Rob
Published: February 2004

We investigate and compare the determinants of US and Australian interest rate swap spreads and the linkages between these markets. The slope of the risk‐free term structure is the most significant determinant and its importance is greater for longer terms to maturity. Interest rate levels and, in Australia, the default premium also have some impact. The influences of interest rate volatility, the liquidity premium and (in the USA) the default premium are small or negligible. We hypothesise, and our evidence confirms, that the US swap market significantly affects the Australian swap market but not vice‐versa.
Size and book to market effects and the Fama French three factor asset pricing model: evidence from the Australian stockmarket
Authors: Gaunt Clive
Published: February 2004

The present study adds to the sparse published Australian literature on the size effect, the book to market (BM) effect and the ability of the Fama French three factor model to account for these effects and to improve on the asset pricing ability of the Capital Asset Pricing Model (CAPM). The present study extends the 1981–1991 period examined by Halliwell, Heaney and Sawicki (1999) a further 10 years to 2000 and addresses several limitations and findings of that research. In contrast to Halliwell, Heaney and Sawicki the current study finds the three factor model provides significantly improved explanatory power over the CAPM, and evidence that the BM factor plays a role in asset pricing.
Examining the forward pricing function of the Australian equity index futures contract
Authors: Ivanovic Irena , Howley Peter
Published: February 2004

The relationship between the Australian equity index futures and spot prices is examined. Tests indicate that futures prices with one, two and three months to maturity are unbiased predictors of the spot and hence provide an efficient hedging mechanism for Australian equity index market participants, while six‐, nine‐ and twelve‐month futures prices are biased predictors of spot prices, indicating that speculative opportunities may exist in futures contracts for these time spreads. An analysis of the short‐run dynamic properties of the long‐run equilibrium relationship found that for all time spreads the futures prices respond to changes in the long‐run equilibrium, and for the twelve‐month contract, both futures and spot prices adjust to return to the long‐run equilibrium.
Reflexive orienting in response to eye gaze and an arrow in children with and without autism
Authors: Senju Atsushi , Tojo Yoshikuni , Dairoku Hitoshi , Hasegawa Toshikazu
Published: February 2004

Background:  This study investigated whether another person's social attention, specifically the direction of their eye gaze, and a non‐social directional cue, an arrow, triggered reflexive orienting in children with and without autism in an experimental situation.

Methods:  Children with autism and typically developed children participated in one of two experiments. Both experiments involved the localization of a target that appeared to the left or right of the fixation point. Before the target appeared, the participant's attention was cued to the left or right by either an arrow or the direction of eye gaze on a computerized face.

Results:  Children with autism were slower to respond, which suggests a slight difference in the general cognitive ability of the groups. In Experiment 1, although the participants were instructed to disregard the cue and the target was correctly cued in only 50% of the trials, both groups of children responded significantly faster to cued targets than to uncued targets, regardless of the cue. In Experiment 2, children were instructed to attend to the direction opposite that of the cues and the target was correctly cued in only 20% of the trials. Typically developed children located targets cued by eye gaze more quickly, while the arrow cue did not trigger such reflexive orienting in these children. However, both social and non‐social cues shifted attention to the cued location in children with autism.

Conclusion:  These results indicate that eye gaze attracted attention more effectively than the arrow in typically developed children, while children with autism shifted their attention equally in response to eye gaze and arrow direction, failing to show preferential sensitivity to the social cue. Difficulty in shifting controlled attention to the instructed side was also found in children with autism.
Maternal sensitivity and infant triadic communication
Authors: Peter Hobson R. , Patrick Matthew P.H. , Crandell Lisa E. , García Pérez Rosa M. , Lee Anthony
Published: February 2004

Background and method:  The aim of this study was to examine whether a mother's sensitivity towards her one‐year‐old infant is related to the infant's propensity to engage in ‘triadic’ relations – that is, to orientate to an adult's engagement with objects and events in the world, for example in sharing experiences with an adult. In order to determine that any effects were specific to infants’ behaviour in the interpersonal domain, we also tested their performance on tests of understanding means–ends relations and object permanence.

Results:  The results were that high maternal sensitivity and low intrusiveness correlated with high levels of infant triadic interpersonal engagement with a stranger vis‐à‐vis performance on the non‐social tasks. There was also suggestive evidence that maternal sensitivity might be related to infants’ propensity to share experiences with the mother. Exploratory analyses revealed that these findings held up when the effects of maternal socio‐economic status and ethnic group were taken into account; and there was some indication that the effects of maternal intrusiveness on infant profiles of performance were more marked for mothers who did not have a partner.

Conclusion:  There is a specific relation between maternal sensitivity and one‐year‐old infants’ propensity to engage with someone else in relation to the world.
The construction and validation of a new scale for measuring emotional response style in adolescents
Authors: Clarbour Jane , Roger Derek
Published: February 2004

Background:  Research on children's emotional behaviour has been hampered by the lack of psychometric assessment scales. The present study reports on the construction and validation of a new self‐report instrument to measure the emotional response styles of adolescents.

Method:  Exploratory and confirmatory factor analyses were carried out on the responses of three samples of adolescents aged between 11 and 14 years (total = 609) to an item pool derived from a scenario study. In addition to assessing reliability, the final form of the questionnaire was concurrently validated using a variety of related psychometric instruments as well as teacher ratings of pupils’ behaviour.

Results:  The factor analyses of the item pool yielded three independent factors labelled social anxiety, malevolent aggression, and social self‐esteem. These categories correspond closely to the three dimensions that have emerged consistently from studies of children's temperament, labelled inhibited, undercontrolled and well‐adjusted. The three factors comprising the final Emotional Behaviour Scale (EBS) all demonstrated satisfactory internal (coefficient alpha) and re‐test reliability. Concurrent validation showed that the three factors were related in predictable ways to other related constructs, and comparisons with teacher ratings of pupils confirmed the relationship between the EBS subscales and children's actual social and emotional behaviour.

Conclusion:  The new scale offers a valid and reliable instrument for assessing adolescent emotional behaviour, and current work is aimed at extending the research to the assessment of young offenders.
Psychosocial functioning of young children with learning problems
Authors: Gadeyne Els , Ghesquière Pol , Onghena Patrick
Published: February 2004

Background:  In this study, psychosocial functioning of different groups of young children with learning problems was investigated using a diverse set of psychosocial variables (including behaviour problems, academic motivation, social preference, and self‐concept).

Methods:  For this purpose, children with low academic achievement, with a specific learning disability based on an IQ–achievement discrepancy, and with a specific learning disability based on an achievement discrepancy, were selected out of 276 children of the first grade of regular primary schools. By means of multivariate analyses, their psychosocial functioning was compared to the functioning of children without learning problems.

Results:  The total set of psychosocial variables was able to discriminate between children with and without learning problems, with medium effect size. Attention problems as reported by the teachers turned out to be the most important single psychosocial predictor for group discrimination. However, results varied according to the type of learning problem and the type of psychosocial problem. Children with a specific reading/spelling disability and children with low general academic achievement differed most from their peers without learning problems with regard to their psychosocial functioning. Poor cognitive self‐concept was related primarily to low academic achievement, poor learning motivation might be specific for math problems, and a low social preference score seemed most characteristic of children with a specific learning disability.

Conclusions:  Studying several psychosocial variables simultaneously in different groups of children with learning problems leads to a further refinement of the current knowledge.
Comorbidity of PTSD and depression among refugee children during war conflict
Authors: Thabet Abdel Aziz Mousa , Abed Yehia , Vostanis Panos
Published: February 2004

Background:  We examined the prevalence and nature of comorbid post‐traumatic stress reactions and depressive symptoms, and the impact of exposure to traumatic events on both types of psychopathology, among Palestinian children during war conflict in the region.

Methods:  The 403 children aged 9–15 years, who lived in four refugee camps, were assessed by completing the Gaza Traumatic Events Checklist, the Child Post Traumatic Stress Reaction Index (CPTSD‐RI), and the Short Mood and Feelings Questionnaire (MFQ).

Results:  Children reported experiencing a wide range of traumatic events, both direct experience of violence and through the media. CPTSD‐RI and MFQ scores were significantly correlated. Both CPTSD‐RI and MFQ scores were independently predicted by the number of experienced traumatic events, and this association remained after adjusting for socioeconomic variables. Exposure to traumatic events strongly predicted MFQ scores while controlling for CPTSD‐RI scores. In contrast, the association between traumatic events and CPTSD‐RI scores, while controlling for MFQ scores, was weak. The CPTSD‐RI items whose frequency was significantly associated with total MFQ scores were: sleep disturbance, somatic complaints, constricted affect, impulse control, and difficulties in concentration. However, not all remaining CPTSD‐RI items were significantly associated with exposure to traumatic events, thus raising the possibility that the association between depression and PTSD was due in part to symptom overlap.

Conclusions:  Children living in war zones are at high risk of suffering from PTSD and depressive disorders. Exposure to trauma was not found to have a unique association with PTSD. The relationship between PTSD and depressive symptomatology requires further investigation.
Children's perspectives on their relationships with their nonresident fathers: influences, outcomes and implications
Authors: Dunn Judy , Cheng Helen , O'Connor Thomas G. , Bridges Laura
Published: February 2004

Background:  Children's relationships with their nonresident fathers, and associations between these relationships, children's relationships with mothers and stepfathers, and the children's adjustment were studied in 162 children from single‐parent and stepfamilies, selected from a representative community sample in the UK, studied at 2 time points two years apart.

Method:  Children were interviewed about their relationships with their nonresident fathers, mothers and stepfathers; mothers reported on children's adjustment, and other family variables.

Results:  Positive child–nonresident father relationships were correlated with (a) contact between child and father, (b) the quality of the mother–child relationship, and (c) the frequency of contact between the mother and her former partner. Conflict between child and father was correlated with conflict between child and mother, and child and stepfather. Child–nonresident father contact and relationships were stable over 2 years, and related to children's adjustment; these associations were stronger for children from single‐parent families than for those with stepfathers, and for those whose mothers had been first pregnant as teenagers.

Conclusions:  Associations between the quality of children's relationships with nonresident fathers and their adjustment need to be considered within the framework of the larger family system; child–father relationships are particularly important for children from ‘high risk’ families.
Juvenile arrest: a cross‐cultural comparison
Authors: Vermeiren Robert , Jones Stephanie M. , Ruchkin Vladislav , Deboutte Dirk , Schwab‐Stone Mary
Published: February 2004

Background:  Cross‐national studies describing the psychopathological characteristics of arrested adolescents are virtually non‐existent. Such studies are important because they have implications for national policy on arrest, case‐management, and future research.

Method:  To address this issue, self‐report surveys administered to representative groups of 12‐ to 16‐year‐old adolescents in New Haven, USA (N = 1138) and Antwerp, Belgium (N = 627) were compared. A number of internalizing and deviant behavior variables were compared between controls (C), non‐arrested antisocial (NA), and arrested antisocial (AR) participants.

Results:  Similar cross‐national arrest rates and levels of antisocial behavior were found. NA and AR youths in both countries reported more internalizing problems, except for anxiety, and more deviant characteristics. Contrary to expectations, the level of depression was not higher in AR compared to NA youth when differences in antisocial behavior between NA and AR were controlled. Also unexpected, arrest showed an independent association with a number of deviant behavior variables.

Conclusions:  Further research should investigate the underlying mechanisms of these associations, as this insight would be useful for developing future intervention and prevention programs, as well as for developing future national policies regarding juvenile antisocial behavior.
Heritability of attention problems in children: longitudinal results from a study of twins, age 3 to 12
Authors: Rietveld M.J.H. , Hudziak J.J. , Bartels M. , van Beijsterveldt C.E.M. , Boomsma D.I.
Published: February 2004

Background:  Twin studies of childhood behavior problems support the conclusion that individual differences in impulsivity, hyperactivity, and inattention are largely due to genetic influences. Non‐genetic variation is due to environmental influences that are unique to the individual, and possibly to rater contrast effects. In the present longitudinal twin study, we report on the size of genetic and environmental effects on individual differences in attention problems at ages 3, 7, 10 and 12 years.

Methods:  Mothers were asked to complete the CBCL for their twin offspring when the children were 3 (n = 11,938), 7 (n = 10,657), 10 (n = 6,192), and 12 years old (n = 3,124). We focus on the Overactivity (OA) scale in the Child Behavior Checklist (CBCL/2–3), and on the Attention Problem (AP) scale of the CBCL/4–18. The data were analyzed using longitudinal structural equation modeling.

Results:  Broad heritability of OA and AP is estimated at nearly 75%, at each age. A contrast effect was observed at age 3 only. The results revealed less stability of OA at age 3 to AP at age 7 (r = .40), compared to the stability from AP at age 7 and beyond (r = .70). Genetic effects explained between 76% and 92% of the covariance between OA and AP.

Conclusions:  OA and AP are highly heritable at all ages in both genders. The same set of genes appears to be expressed in boys and girls. The size of genetic and environmental contributions remains the same across the ages studied. Stability in OA and AP is accounted for by genetic influences. Children who do not display OA or AP at a given age are unlikely to develop these problems at a subsequent age.
Familial clustering of latent class and DSM‐IV defined attention‐deficit/hyperactivity disorder (ADHD) subtypes
Authors: Rasmussen Erik R. , Neuman Rosalind J. , Heath Andrew C. , Levy Florence , Hay David A. , Todd Richard D.
Published: February 2004

Background:  Findings from family and twin‐based studies of Attention Deficit/Hyperactivity Disorder (ADHD) have indicated that inattentive and combined subtypes cluster together among sibling pairs who both express ADHD symptoms. The current report examines the familial clustering of ADHD subtypes, defined according to latent class and DSM‐IV criteria, in a general population sample of 2,848 Australian twins, 1,013 of their non‐twin siblings and 4,036 female twins from Missouri, USA. Significant clustering of DSM‐IV inattentive and combined subtypes, and significant clustering of the same latent classes among siblings was predicted.

Method:  Logistic regression was used to assess 1) the clustering of same and different subtype combinations among twin and twin‐sibling pairs and 2) whether genetic influences contribute significantly to the observed patterns of subtype combinations among siblings.

Results:  With the exception of the DSM‐IV hyperactive‐impulsive subtype and the severe hyperactive‐impulsive latent class, all other sibling DSM‐IV and latent class ADHD subtypes consistently exhibited significant same‐subtype clustering with MZ probands, DZ probands and their siblings in both samples. Furthermore, a significant genetic influence contributing to subtype concordance was detected for every DSM‐IV subtype excluding hyperactive‐impulsive, and for all eight latent classes. While some instances of significant different‐subtype clustering among siblings was observed across both classification systems and samples, the particular subtype combinations involved were largely inconsistent across samples and no significant genetic influences contributing towards these discordant subtype combinations were detected.

Conclusions:  For both DSM‐IV and latent class subtypes, the overall pattern of findings in both samples indicated significant familial clustering of same‐subtype combinations and significant genetic influences contributing to these patterns of subtype concordance, despite important sample differences. These findings further extend previous work and are most consistent with the presence of multiple independent forms of ADHD.
Improving estimation of the prognosis of childhood psychopathology; combination of DSM‐III‐R/DISC diagnoses and CBCL scores
Authors: Ferdinand Robert F. , Visser Jeroen Heijmens , Hoogerheide Kirsten N. , Ende Jan van der , Kasius Marianne C. , Koot Hans M. , Verhulst Frank C.
Published: February 2004

Objective:  To compare the predictive validity of the clinical‐diagnostic and the empirical‐quantitative approach to assessment of childhood psychopathology, and to investigate the usefulness of combining both approaches.

Method:  A referred sample (N = 96), aged 6 to 12 years at initial assessment, was followed up across – on average – a period of 3.2 years. It was assessed to what extent DISC/DSM‐III‐R diagnoses – representing the clinical‐diagnostic approach, and CBCL scores – representing the empirical‐quantitative approach, predicted the following signs of poor outcome: outpatient/inpatient treatment, or parents’ wish for professional help for the child at follow‐up, disciplinary problems in school, and police/judicial contacts.

Results:  Both diagnostic systems added significantly to the prediction of poor outcome, and neither of the two systems was superior. Use of both systems simultaneously provided the most accurate estimation of the prognosis, reflected by the occurrence of future poor outcome. Even diagnostic concepts that are generally regarded as relatively similar, such as ADHD (DSM) and attention problems (CBCL), or conduct disorder (DSM) and delinquent behavior (CBCL), appeared to differ in their ability to predict poor outcome.

Conclusions:  The present study supports the use of the empirical‐quantitative approach and the clinical‐diagnostic approach simultaneously, both in research and in clinical settings, to obtain a comprehensive view of the prognosis of psychopathology in children.
Successful Surgical Treatment of Mitral Valve Stenosis in a Dog
Authors: Borenstein N. , Daniel P. , Behr L. , Pouchelon J.L. , Carbognani D. , Pierrel A. , Macabet V. , Lacheze A. , Jamin G. , Carlos C. , Chetboul V. , Laborde F.
Published: February 2004

Objective—To report the successful surgical management (open mitral commissurotomy, OMC) of mitral stenosis (MS), incorporating heart‐beating cardiopulmonary bypass (CPB), in a 1‐year‐old dog.

Study Design—Clinical case.

Animals—One‐year‐old Cairn Terrier with MS.

Materials and Methods—Diagnosis of MS was confirmed by means of 2‐dimensional, continuous‐wave and color‐flow Doppler echocardiography. Surgery was performed through a left intercostal thoracotomy. CPB was initiated and the heart was kept beating. The fused commissures of the mitral valve were incised to free the cusps of the valve.

Results—Left intercostal thoracotomy allowed easy observation of the mitral orifice during heart‐beating OMC. Persistent bleeding from the atriotomy site required a second surgical procedure after which the dog had an uneventful recovery. Echocardiography at 2 weeks and 1 year postoperatively indicated substantial improvement in left ventricular filling (pressure half‐time=187 ms before surgery, 105 ms [2 weeks] and 110 ms [1 year] after surgery). Enlargement of the left atrium resolved; however, moderate mitral valve regurgitation was still present.

Conclusions—MS can be successfully treated by OMC, facilitated by use of CPB. Substantial improvement in cardiac function was evident by ultrasound and Doppler examination postoperatively.

Clinical Relevance—OMC under heart‐beating CPB should be considered for the treatment of MS in the dog.
Exercise and training effects on ceramide metabolism in human skeletal muscle
Authors: Helge Jørn Wulff , Dobrzyn Agnieszka , Saltin Bengt , Gorski Jan
Published: February 2004

In rat skeletal muscle prolonged exercise affects the content and composition of ceramides, but in human skeletal muscle no data are available on this compound. Our aim was to examine the content of ceramide‐ and sphingomyelin fatty acids and neutral, Mg2+‐dependent sphingomyelinase activity in skeletal muscle in untrained and trained subjects before and after prolonged exercise. Healthy male subjects were recruited into an untrained (n= 8, VO2,max 3.8 ± 0.2 l min1) and a trained (n= 8, VO2,max 5.1 ± 0.1 l min1) group. Before and after a 3‐h exercise bout (58 ± 1%VO2,max) a muscle biopsy was excised from the vastus lateralis. Ceramide and sphingomyelin were isolated using thin‐layer chromatography. The content of individual ceramide fatty acids and sphingomyelin fatty acids was measured by means of gas‐liquid chromatography. The activity of neutral, Mg2+‐dependent sphingomyelinase was measured using N‐[14CH3]‐sphingomyelin as a substrate. Prior to exercise, the muscle total ceramide fatty acid content in both groups was similar (201 ± 18 and 197 ± 9 nmol g−1 in the untrained and trained group, respectively) and after exercise a 25% increase in the content was observed in each group. At rest, the muscle total sphingomyelin fatty acid content was higher in untrained than in trained subjects (456 ± 10, 407 ± 7 nmol g−1, respectively; P < 0.05). After exercise a 20% increase (P < 0.05) in total sphingomyelin was observed only in the trained subjects. The muscle neutral, Mg2+‐dependent sphingomyelinase activity was similar in the two groups at rest and a similar reduction was observed after exercise in both groups (untrained from 2.19 ± 0.08 to 1.78 ± 0.08 and trained from 2.31 ± 0.12 to 1.80 ± 0.09 nmol (mg protein)−1 h−1; P < 0.05 in each case). In conclusion, we have reported, for the first time, the values for ceramide fatty acid content and neutral, Mg2+‐dependent sphingomyelinase activity in human skeletal muscle. The results indicate that acute prolonged exercise affects ceramide metabolism in human skeletal muscle both in untrained and in trained subjects and this may influence muscle cell adaptation and metabolism.
Effect of polyphenolic compounds on the renal Na+,K+‐ATPase during development and persistence of hypertension in rats
Authors: Javorková Veronika , Pechánová Olga , Andriantsitohaina Ramaroson , Vrbjar Norbert
Published: February 2004

It has been suggested that polyphenolic substances provide protection against the risk factors of cardiovascular diseases. The present study was designed to investigate whether application of red wine polyphenols influences the kinetic properties of the renal Na+,K+‐ATPase in rats with hypertension (164 ± 8 mmHg) that was experimentally induced by the NO synthase inhibitorNG.‐nitro‐larginine methyl ester (l‐NAME). Polyphenols in a dose of 40 mg kg−1day−1in drinking fluid induced different effects on the properties of the renal Na+,K+‐ATPase depending on the mode of their administration. Preventive application of polyphenols during the development of hypertension (144 ± 5 mmHg) partially protected the Na+,K+‐ATPase molecule against hypertension‐induced deterioration via increased capability of the enzyme to bind ATP and/or Na+as suggested by decrease ofKmandKNa, respectively, even to values lower than in controls. However, polyphenols did not prevent the hypertension‐induced reduction of the number of active Na+,K+‐ATPase molecules as shown by similarVmaxvalues as compared to the hypertensivel‐NAME group. The above protection is probably secured by a NO‐dependent mechanism as suggested by 150% increase of the NO synthesis. Additional treatment of already hypertensive animals with polyphenols (153 ± 8 mmHg) resulted in partial restoration of the Na+,K+‐ATPase affinities especially for sodium as indicated by significant diminution ofKNa. However, polyphenols in this mode of application did not slow down thel‐NAME‐induced decrease in the number of Na+,K+‐ATPase molecules in the kidney as suggested by additional significant decrease inVmaxvalues when comparing this group with the control group and also the hypertensivel‐NAME group. In this case the polyphenols affected the Na,K‐ATPase molecule in a NO‐independent way as indicated by the fact that polyphenols failed to restore normal NO synthesis.
A definition of internal constancy and homeostasis in the context of non‐equilibrium thermodynamics
Authors: Recordati G. , Bellini T. G.
Published: February 2004

The constancy of the internal environment, internal homeostasis, and its stability are necessary conditions for the survival of a biological system within its environment. These have never been clearly defined. For this purpose nonequilibrium thermodynamics is taken as a reference, and the essential principles of equilibrium, reversibility, stationary steady state and stability (Lyapounov, asymptotic, local and global), are briefly illustrated. On this basis, internal homeostasis describes a stationary state of nonequilibrium, the actual state of rest, X(t), resulting from the relation X(t) = XS+ x(t), between a time‐independent steady state of reference (XS), and time‐dependent fluctuations of the state variables, x(t). In humans, two resting spontaneous homeostatic states are: (1) the conscious state of quiet wakefulness, during which time‐dependent variables display bounded oscillations around the mean time‐independent steady state level, this conscious state being thus stable in the sense of Lyapounov, and (2) the unconscious stable state of non‐rapid eye movement sleep, in which the time‐dependent variables would approach the lowest spontaneously attainable time‐independent state asymptotically, sleep becoming a globally stable and attractive state. Exercise may be described as a non‐resting, unstable active state far away from equilibrium and hibernation is a resting, time‐independent steady state very near equilibrium. The range between sleep and exercise is neurohumorally regulated. For spontaneously stable states to occur, slowing of the metabolic rate, withdrawal of the sympathetic drive and reinforcement of the vagal tone to the heart and circulation are required, thus confirming that the parasympathetic division of the autonomic nervous system is the main controller of homeostasis.
Effect of time of day and rabbit strain on patterns of aortic wall permeability
Authors: Staughton Tracey J. , Weinberg Peter D.
Published: February 2004

Lipid deposits occur more frequently downstream of branch points than upstream in immature rabbit and human aortas but the opposite pattern is seen in mature vessels. These distributions correlate spatially with age‐related patterns of aortic permeability, observed in rabbits, and may be determined by them. The mature but not the immature pattern of permeability is dependent on endogenous nitric oxide synthesis. Although the transport patterns have hitherto seemed robust, recent studies have given the upstream pattern in some mature rabbits but the downstream pattern in others. Here we show that transport in mature rabbits is significantly skewed to the downstream pattern in the afternoon compared with the morning (P < 0.05), and switches from a downstream to an upstream pattern at around 21 months in rabbits of the Murex strain, but at twice this age in Highgate rabbits (P < 0.001). The effect of time of day was not explained by changes in nitric oxide production, assessed from plasma levels of nitrate and nitrate, nor did it correlate with conduit artery tone, assessed from the shape of the peripheral pulse wave. The effect of strain could not be explained by variation in nitric oxide production nor by differences in wall structure. The effects of time of day and rabbit strain on permeability patterns explain recent discrepancies, provide a useful tool for investigating underlying mechanisms and may have implications for human disease.
Gastric emptying and fluid availability after ingestion of glucose and soy protein hydrolysate solutions in man
Authors: Maughan Ronald J. , Leiper John B. , Vist Gunn E.
Published: February 2004

The double sampling gastric aspiration method was used to measure the effect of energy content on the rate of gastric emptying of glucose and soy protein hydrolysate solutions. The net rate of absorption of water from these solutions was assessed using deuterium oxide as a tracer for water. Six healthy male subjects were each studied on four separate occasions using a test drink volume of 600 ml. The half emptying times (t1/2, median (range)) of the iso‐energetic soy protein hydrolysate (6P, 60 g l−1, 36 (14–39) min) and glucose (7G, 70 g l−1, 25 (19–29) min) solutions were similar. These two solutions (6P, 7G) delivered energy to the small intestine at similar rates, and resulted in similar rates of accumulation of the deuterium tracer in the circulation. The dilute glucose solution (LG, 23 g l−1) was emptied faster (t1/2 13 (11–19) min) and resulted in a faster rate of tracer accumulation in the circulation than any of the other solutions, including the iso‐osmotic soy protein solution (LG 311 ± 5 mosmol kg−1, 6P 321 ± 24 mosmol kg−1). The concentrated soy protein hydrolysate solution (12P, 120 g l−1) emptied more slowly (t1/2 80 (44–120) min) than the more dilute solutions. The rate of energy delivery to the small intestine from 12P was similar to that from 6P for the first 50 min after ingestion, and similar to that from 7G at all sample points. These results indicate that the iso‐energetic solutions of glucose and soy protein hydrolysate used in this study are emptied from the stomach at similar rates and result in similar rates of fluid availability after ingestion.
Interactions of chemostimuli at the single cell level: studies in a model system
Authors: Peers Chris
Published: February 2004

The responses of afferent chemosensory fibres of the carotid body to individual chemostimuli have long been established. However, the mechanisms underlying the multiplicative interactions of these stimuli (i.e. how the combined effects of hypoxia and hypercapnia exert a greater effect on afferent nerve discharge than the sum of their individual effects) have not been elucidated. Using the membrane hypothesis for carotid body chemoreception, in which chemostimuli inhibit type I cell K+ channels, leading to depolarization, voltage‐gated Ca2+ entry and hence the triggering of exocytosis, this article considers data acquired in isolated type I carotid body cells and model chemoreceptor (PC12) cells to attempt to explain stimulus interactions. Whilst stimulus interactions are not clearly evident at the level of K+ channel inhibition or rises of [Ca2+]i, they are apparent at the level of transmitter release. Thus, it is clear that individual chemoreceptor cells can sense multiple stimuli, and that interactions of these stimuli can produce greater than additive effects in terms of transmitter release.
Retrospective view of the carotid body research of Ronan G. O'Regan
Authors: Jones James F. X.
Published: February 2004

The Irish experimental physiologist Ronan G. O'Regan has made a substantial contribution to the field of autonomic control of the carotid body. This brief retrospective has been written by one of his former students, one of many to whom the beauty of Nature's design has been revealed through O'Regan's lectures and scientific papers. I shall describe some of his experiments that were performed from 1965 to 1981 in this historical sketch.
Computational physiology and the physiome project
Authors: Crampin Edmund J. , Halstead Matthew , Hunter Peter , Nielsen Poul , Noble Denis , Smith Nicolas , Tawhai Merryn
Published: February 2004

Bioengineering analyses of physiological systems use the computational solution of physical conservation laws on anatomically detailed geometric models to understand the physiological function of intact organs in terms of the properties and behaviour of the cells and tissues within the organ. By linking behaviour in a quantitative, mathematically defined sense across multiple scales of biological organization – from proteins to cells, tissues, organs and organ systems – these methods have the potential to link patient‐specific knowledge at the two ends of these spatial scales. A genetic profile linked to cardiac ion channel mutations, for example, can be interpreted in relation to body surface ECG measurements via a mathematical model of the heart and torso, which includes the spatial distribution of cardiac ion channels throughout the myocardium and the individual kinetics for each of the approximately 50 types of ion channel, exchanger or pump known to be present in the heart. Similarly, linking molecular defects such as mutations of chloride ion channels in lung epithelial cells to the integrated function of the intact lung requires models that include the detailed anatomy of the lungs, the physics of air flow, blood flow and gas exchange, together with the large deformation mechanics of breathing. Organizing this large body of knowledge into a coherent framework for modelling requires the development of ontologies, markup languages for encoding models, and web‐accessible distributed databases. In this article we review the state of the field at all the relevant levels, and the tools that are being developed to tackle such complexity. Integrative physiology is central to the interpretation of genomic and proteomic data, and is becoming a highly quantitative, computer‐intensive discipline.
Structural basis of hypoxic pulmonary hypertension: the modifying effect of chronic hypercapnia
Authors: Howell Katherine , Ooi Henry , Preston Rob , McLoughlin Paul
Published: February 2004

Exposure to chronic hypoxia causes pulmonary hypertension and pulmonary vascular remodelling. In chronic lung disease, chronic hypercapnia frequently coexists with hypoxia and is associated with worsening of pulmonary hypertension. It is generally stated that pulmonary hypertension in these conditions is secondary to hypoxic vascular remodelling and that hypercapnia augments this remodelling thus worsening the hypertension. We review recent evidence which shows that although chronic hypoxia causes thickening of the walls of pulmonary arterioles, these changes do not lead to structural narrowing of the lumen by encroachment. Moreover, hypoxia leads to new vessel formation within the pulmonary vasculature and not loss of vessels as formerly thought. Such neovascularization may provide a beneficial adaptation by increasing the area of the gas exchange membrane. These novel structural findings are supported by recent reports that inhibitors of the RhoA pathway can acutely reduce pulmonary vascular resistance in chronically hypoxic lungs to near normal values, demonstrating that structural changes are not the dominant mechanisms underling hypoxic pulmonary hypertension. Chronic hypercapnia inhibits the development of hypoxic pulmonary hypertension, pulmonary vascular remodelling and hypoxia‐induced angiogenesis. This last effect might be maladaptive, as it would prevent the potentially beneficial increase in gas exchange membrane area. These findings suggest that structural narrowing of the vascular lumen of resistance vessels is not the mechanism by which hypoxia and hypercapnia cause pulmonary hypertension in chronic lung disease.