bluuebunny/crossref_metadata_2025 huggingface dataset:
Skin Reactions to Intradermal Neuromuscular Blocking Agent Injections
Authors: Mertes Paul Michel , Moneret-Vautrin Denise Anne , Leynadier Francisque , Laxenaire Marie-Claire
Published: July 2007

Background

Numerous reports confirm the performance of intradermal tests for the diagnosis of anaphylaxis during anesthesia; however, there is controversy over their diagnostic value regarding the newer neuromuscular blocking agents (NMBAs).

Methods

One hundred eleven healthy volunteers were randomly assigned to receive intradermal injections of two NMBAs, at five increasing concentrations. A concentration was considered as a reactive concentration when it led to a positive reaction in more than 5% of the subjects. These concentrations were compared with the maximal concentration recommended for the diagnosis of sensitization to NMBAs.

Results

The maximal nonreactive concentrations were 10 m for suxamethonium; 10 m for pancuronium, vecuronium, rocuronium, and cisatracurium; and 10 m for atracurium and mivacurium. Except for mivacurium, these nonreactive concentrations were close to the maximal concentrations used for the diagnosis of sensitization against NMBAs. For mivacurium, the nonreactive concentrations were higher than the maximal concentration currently recommended in clinical practice.

Conclusion

The aminosteroidal NMBAs pancuronium, vecuronium, and rocuronium and the benzylisoquinoline cisatracurium have a similar potency to induce a nonspecific skin reactivity. If the criteria for positivity and the maximal concentrations of the commercially available compounds recommended by French practice guidelines are used, the risk of false-positive results is limited, and only minor modifications of these recommendations could be suggested. A slight reduction in the maximal concentration used for rocuronium from 1:100 to 1:200 and an increase from 1:1,000 to 1:200 for mivacurium can be proposed.
Differential Dynamic of Action on Cortical and Subcortical Structures of Anesthetic Agents during Induction of Anesthesia
Authors: Velly Lionel J. , Rey Marc F. , Bruder Nicolas J. , Gouvitsos François A. , Witjas Tatiana , Regis Jean Marie , Peragut Jean Claude , Gouin François M.
Published: July 2007

Background

Dynamic action of anesthetic agents was compared at cortical and subcortical levels during induction of anesthesia. Unconsciousness involved the cortical brain but suppression of movement in response to noxious stimuli was mediated through subcortical structures.

Methods

Twenty-five patients with Parkinson disease, previously implanted with a deep-brain stimulation electrode, were enrolled during the implantation of the definitive pulse generator. During induction of anesthesia with propofol (n = 13) or sevoflurane (n = 12) alone, cortical (EEG) and subcortical (ESCoG) electrogenesis were obtained, respectively, from a frontal montage (F3-C3) and through the deep-brain electrode (p0-p3). In EEG and ESCoG spectral analysis, spectral edge (90%) frequency, median power frequency, and nonlinear analysis dimensional activation calculations were determined.

Results

Sevoflurane and propofol decreased EEG and ESCoG activity in a dose-related fashion. EEG values decreased dramatically at loss of consciousness, whereas there was little change in ESCoG values. Quantitative parameters derived from EEG but not from ESCoG were able to predict consciousness versus unconsciousness. Conversely, quantitative parameters derived from ESCoG but not from EEG were able to predict movement in response to laryngoscopy.

Conclusion

These data suggest that in humans, unconsciousness mainly involves the cortical brain, but that suppression of movement in response to noxious stimuli is mediated through the effect of anesthetic agents on subcortical structures.
Activation of Opioid μ Receptors in Caudal Medullary Raphe Region Inhibits the Ventilatory Response to Hypercapnia in Anesthetized Rats
Authors: Zhang Zhenxiong , Xu Fadi , Zhang Cancan , Liang Xiaomin
Published: July 2007

Background

: Opioids, extensively used as analgesics, markedly depress ventilation, particularly the ventilatory responsiveness to hypercapnia in humans and animals predominantly via acting on mu receptors. The medullary raphe region (MRR) contains abundant mu receptors responsible for analgesia and is also an important central area involving carbon dioxide chemoreception and contributing to the ventilatory responsiveness to hypercapnia. Therefore, the authors asked whether activation of mu receptors in the caudal, medial, or rostral MRR depressed ventilation and the response to hypercapnia, respectively.

Methods

: Experiments were conducted in 32 anesthetized and spontaneously breathing rats. Ventilation and it response to progressive hypercapnia were recorded. The slopes obtained from plotting minute ventilation, respiratory frequency, and tidal volume against the corresponding levels of end-tidal pressure of carbon dioxide were used as the indices of the respiratory responsiveness to carbon dioxide. DAMGO ([d-Ala2, N-Me-Phe4, Gly-ol]-enkephalin), a mu-receptor agonist, was systemically administered (100 mug/kg) before and/or after local injection of CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2) (100 ng/100 nl), a mu-receptor antagonist, into the caudal MRR, or locally administered (35 ng/100 nl) into the MRR subnuclei.

Results

: The authors found that systemic DAMGO significantly inhibited ventilation and the response to carbon dioxide by 20% and 31%, respectively, and these responses were significantly diminished to 11% and 14% after pretreatment of the caudal MRR with CTAP. Local administration of DAMGO into the caudal MRR also reduced ventilation and the response to carbon dioxide by 22% and 28%, respectively. In sharp contrast, these responses were not observed when the DAMGO microinjection was made in the middle MRR or rostral MRR.

Conclusions

: These results lead to the conclusion that mu receptors in the caudal MRR rather than the middle MRR or rostral MRR are important but not exclusive for attenuating the hypercapnic ventilatory response.
The ability of the SCORE high-risk model to predict 10-year cardiovascular disease mortality in Norway
Authors: Lindman Anja S. , Veierød Marit B. , Pedersen Jan I. , Tverdal Aage , Njølstad Inger , Selmer Randi
Published: July 2007

Aims

To evaluate the predictive accuracy of the Systematic Coronary Risk Evaluation (SCORE) project high-risk function in Norway.

Methods and results

We included 57229 individuals screened in 1985-1992 from two population-based surveys in Norway (age groups 40-49, 50-59, and 60-69 years). The data have been linked to the Norwegian Cause of Death Registry. The SCORE high-risk algorithm for the prediction of 10-year cardiovascular disease (CVD) mortality was applied, and the risk factors entered into the model were age, sex, total cholesterol, systolic blood pressure, and smoking (yes/no). The number of expected events estimated by the SCORE model (E) was compared with the observed numbers (O). The SCORE low-risk algorithm was studied for comparison. In men, the observed number of CVD deaths was 718, compared with 1464 estimated by the SCORE high-risk function (O/E ratios 0.53, 0.53 and 0.45, for age groups 40-49, 50-59 and 60-69, respectively). In women, the observed and expected numbers were 226 and 547. The O/E ratios decreased with age (ratios 0.60, 0.45 and 0.37, respectively), i.e. the overestimation increased with age. The low-risk function predicted reasonably well for men (ratios 0.85, 0.92 and 0.79, respectively), whereas an overestimation was found for women aged 50-59 and 60-69 years (ratios 0.69 and 0.56, respectively).

Conclusion

The SCORE high-risk model overestimated the number of CVD deaths in Norway. Before implementation in clinical practice, proper adjustments to national levels are required.
A comparison of the prevalence of the metabolic syndrome and its components among native Japanese and Japanese Brazilians residing in Japan and Brazil
Authors: Schwingel Andiara , Nakata Yoshio , Ito Lucy S. , Chodzko-Zajko Wojtek J. , Shigematsu Ryosuke , Erb Christopher T. , Oba-Shinjo Sueli M. , Matsuo Tomoaki , Shinjo Samuel K. , Uno Miyuki , Marie Suely K. N. , Tanaka Kiyoji
Published: July 2007

Background

This study investigated the prevalence of risk factors associated with the metabolic syndrome (MetSyn) among individuals of Japanese descent exposed to different cultural environments.

Design

A cross-sectional study to assess component risk factors for the diagnosis of MetSyn was undertaken in urban areas in Japan and Brazil. A total of 773 men and women aged 35 years or over were included in three groups: 249 native Japanese, 269 Brazilian individuals of Japanese ancestry residing in Japan, and 255 Brazilian individuals of Japanese ancestry residing in Brazil.

Results

Higher rates of metabolic abnormalities with respect to central obesity and serum lipid profiles were observed among Brazilian individuals of Japanese ancestry residing in Brazil compared with those residing in Japan and native Japanese. Likewise, an increased risk of hypertension was observed among Japanese Brazilian individuals residing in Japan. The prevalence of MetSyn in men was significantly higher among Brazilians of Japanese ancestry residing in Brazil (37.5%) compared with those residing in Japan (25.3%) or native Japanese (21.4%), whereas no significant difference was observed among women. In the logistic model, Brazilian individuals of Japanese ancestry residinginBrazil weretwice as likely to develop MetSyn compared with native Japanese, whereas no significant differences were found among those residing in Japan.

Conclusions

These findings underscore the significant heterogeneity in risk factors among communities of Japanese ancestry residing in Brazil and Japan, and suggest that immigrants exposed to the Brazilian cultural environment are more susceptible to the development of risk factors associated with MetSyn than native Japanese.
Association between anthropometric measures of obesity and cardiovascular risk markers in a self-selected group of indigenous Australians
Authors: Chan Lionel C.K. , Ware Robert S. , Kesting Janine , Marczak Maureen , Good David , Shaw Joanne T.E.
Published: July 2007

Background

Indigenous Australians have a high prevalence of obesity and an unacceptably high rate of cardiovascular disease.

Methods

We conducted a cross-sectional analysis of 93 high-risk indigenous Australians to assess how strongly three anthropometric measures correlated with known cardiovascular risk factors.

Results

Both waist circumference and body mass index were strongly associated with important risk factors. The waist: hip ratio was less useful. Waist circumference was the only measure that significantly correlated with the urine albumin creatinine ratio (ρ = 0.14; P =0.04).

Conclusion

Measuring the waist circumference is a cheap, effective way of monitoring cardiovascular risk.
Cardiovascular disease risk profiles among ‘healthy’ siblings of patients with early-onset cardiovascular disease: application of the new SCORE system
Authors: Horan Paul G. , Kamaruddin Muhammad S. , Moore Michael J. , McCarty David , Spence Mark S. , McGlinchey Paul G. , Murphy Gillian , Jardine Tracy C.L. , Patterson Chris C. , McKeown Pascal P.
Published: July 2007

Background

Cardiovascular disease (CVD) occurs more frequently in individuals with a family history of premature CVD. Within families the demographics of CVD are poorly described.

Design

We examined the risk estimation based on the Systematic Coronary Risk Evaluation (SCORE) system and the Joint British Guidelines (JBG) for older unaffected siblings of patients with premature CVD (onset ≤ 55 years for men and ≤ 60 years for women).

Methods

Between August 1999 and November 2003 laboratory and demographic details were collected on probands with early-onset CVD and their older unaffected siblings. Siblings were screened for clinically overt CVD by a standard questionnaire and 12-lead electrocardiogram (ECG).

Results

A total of 790 siblings was identified and full demographic details were available for 645. The following siblings were excluded: 41 with known diabetes mellitus; seven with random plasma glucose of 11.1 mmol/l or greater; and eight with ischaemic ECG. Data were analysed for 589 siblings from 405 families. The mean age was 55.0 years, 43.1% were men and 28.7% were smokers. The mean total serum cholesterol was 5.8 mmol/l and hypertension was present in 49.4%. Using the SCORE system, when projected to age 60 years, 181 men (71.3%) and 67 women (20.0%) would be eligible for risk factor modification. Using JBG with a 10-year risk of 20% or greater, 42 men (16.5%) and four women (1.2%) would be targeted.

Conclusions

Large numbers of these asymptomatic individuals meet both European and British guidelines for the primary prevention of CVD and should be targeted for risk factor modification. The prevalence of individuals defined as eligible for treatment is much higher when using the SCORE system.
Smoking and myocardial infarction case-fatality: hospital and population approach
Authors: Elosua Roberto , Vega Gema , Rohlfs Izabella , Aldasoro Elena , Navarro Carmen , Cabades Adolfo , Demissie Serkalem , Segura Antonio , Fiol Miquel , Moreno-Iribas Concepción , Echanove Ildefonso , Tormo María José , Arteagoitia José María , Sala Joan , Marrugat Jaume ,   on behalf of the IBERICA investigators
Published: July 2007

Background

Smoking is a risk factor for coronary heart disease, but it has been associated with better short-term prognosis in hospitalized patients with acute myocardial infarction. The aims of this study were to determine the association between smoking and myocardial infarction 28-day case-fatality in hospitalized patients and at the population level; and, whether smokers presenting with fatal myocardial infarction are more likely to die before reaching a hospital.

Design and methods

Population-based myocardial infarction registry, carried out in 1997-1998 in seven regions of Spain, used standardized methods to find and analyze suspected myocardial infarction patients (10 654 patients; 7796 hospitalized). Four categories of smoking status were defined: never-smokers, former smokers for more than 1 year, former smokers for less than 1 year, and current smokers.

Results

The main end-point was 28-day case-fatality, found to be 20.1, 17.1, 15.6, and 8.9%, in the four smoking status categories, respectively, for hospitalized patients; and 37.4, 33.0, 24.5, and 23.2%, respectively, at population level. Hospitalized current smokers had lower age, sex, and comorbidity-adjusted 28-day case-fatality than never-smokers (odds ratio = 0.71; 95% confidence interval: 0.56-0.90). This association held at population level (odds ratio = 0.68; 95% confidence interval: 0.60-0.76), in which former smoking was also associated with lower case-fatality. In fatal cases, recent former smokers presented a lower risk of out-of-hospital death than never-smokers (odds ratio = 0.47; 95% confidence interval: 0.29-0.77), whereas current smoking was marginally associated with out-of-hospital death (odds ratio = 1.22; 95% confidence interval: 0.99-1.50).

Conclusions

Current smoking is associated with lower 28-day case-fatality in hospitalized myocardial infarction patients. This association held at population level. Among fatal cases, smoking is associated with higher and recent former smoking with lower risk of dying out-of-hospital.
Cardiorespiratory fitness relates more strongly than physical activity to cardiovascular disease risk factors in healthy children and adolescents: the European Youth Heart Study
Authors: Hurtig-Wennlöf Anita , Ruiz Jonatan R. , Harro Maarike , Sjöström Michael
Published: July 2007

Background

Physical activity and cardiorespiratory fitness are closely related to health variables in adults, especially those considered to be among risk factors for cardiovascular diseases. The possible tracking of cardiovascular disease risk factors from childhood to adulthood makes it important to increase our understanding of the complex relationships between physical activity, cardiorespiratory fitness and cardiovascular risk factors early in life.

Design

A cross-sectional, school-based study on healthy children and adolescents, aged 9-10 years (295 girls, 295 boys) and 15-16 years (302 girls, 233 boys) was performed during a school year in Sweden and Estonia, as part of the European Youth Heart Study.

Methods

Total physical activity, and minutes spent in inactivity and activity of moderate or higher intensity were measured by accelerometry. A maximal ergometer bike test was used for estimation of cardiorespiratory fitness. The risk factors included blood pressure and fasting blood levels of insulin, glucose, triglycerides, total cholesterol and high-density lipoprotein cholesterol.

Results

Canonical correlations between physical activity and cardiorespiratory fitness versus cardiovascular disease risk factors showed significant associations in both age and sex groups ( rc=0.46-0.61, P < 0.0001). The cardiorespiratory fitness was found to be the strongest contributor to these relationships. In girls high values of the physical activity variables were also associated with a favourable cardiovascular profile.

Conclusions

Cardiorespiratory fitness relates more strongly to cardiovascular risk factors than components of objectively measured physical activity in children and adolescents. Physical activity becomes more important in the 15-year-old adolescents, indicating that these modifiable lifestyle factors increase in importance with age.
Worker caste determination in the army antEciton burchellii
Authors: Jaffé Rodolfo , Kronauer Daniel J.C , Bernhard Kraus F , Boomsma Jacobus J , Moritz Robin F.A
Published: July 2007

Elaborate division of labour has contributed significantly to the ecological success of social insects. Division of labour is achieved either by behavioural task specialization or by morphological specialization of colony members. In physical caste systems, the diet and rearing environment of developing larvae is known to determine the phenotype of adult individuals, but recent studies have shown that genetic components also contribute to the determination of worker caste. One of the most extreme cases of worker caste differentiation occurs in the army ant genusEciton, where queens mate with many males and colonies are therefore composed of numerous full-sister subfamilies. This high intracolonial genetic diversity, in combination with the extreme caste polymorphism, provides an excellent test system for studying the extent to which caste determination is genetically controlled. Here we show that genetic effects contribute significantly to worker caste fate inEciton burchellii. We conclude that the combination of polyandry and genetic variation for caste determination may have facilitated the evolution of worker caste diversity in some lineages of social insects.
Genetic dissimilarity predicts paternity in the smooth newt (
Lissotriton vulgaris
)
Authors: Jehle Robert , Sztatecsny Marc , Wolf Jochen B.W , Whitlock April , Hödl Walter , Burke Terry
Published: July 2007

Under sperm competition, paternity is apportioned by polyandrous females according to the order of matings and the genetic quality of the inseminating males. In order to distinguish between these two effects, we sequentially paired 12 female smooth newts (
Lissotriton vulgaris
) with each of two males and, where possible, repeated the same procedure in reverse order of the identical males after assumed sperm depletion. For a total of 578 offspring, amplified fragment length polymorphisms genetic markers revealed multiple paternities in all matings, without significant first- or second-male sperm precedence. The paternity share of individual males was transitive across the two trials with male order switch, and successful males had a significantly higher genetic dissimilarity to the female than expected by chance. We argue that patterns of paternity in natural newt populations are determined through a combination of good genes and relatedness.
Tuning the geometrical parameters of biomimetic fibrillar structures to enhance adhesion
Authors: Chen Shaohua , Soh Ai Kah
Published: July 2007

Fibrillar structures are common features on the feet of many animals, such as geckos, spiders and flies. Theoretical analyses often use periodical array to simulate the assembly, and each fibril is assumed to be of equal load sharing (ELS). On the other hand, studies on a single fibril show that the adhesive interface is flaw insensitive when the size of the fibril is not larger than a critical one. In this paper, the Dugdale–Barenblatt model has been used to study the conditions of ELS and how to enhance adhesion by tuning the geometrical parameters in fibrillar structures. Different configurations in an array of fibres are considered, such as line array, square and hexagonal patterns. It is found that in order to satisfy flaw-insensitivity and ELS conditions, the number of fibrils and the pull-off force of the fibrillar interface depend significantly on the fibre separation, the interface interacting energy, the effective range of cohesive interaction and the radius of fibrils. Proper tuning of the geometrical parameters will enhance the pull-off force of the fibrillar structures. This study may suggest possible methods to design strong adhesion devices for engineering applications.
Application of discontinuity layout optimization to plane plasticity problems
Authors: Smith Colin , Gilbert Matthew
Published: July 2007

A new and potentially widely applicable numerical analysis procedure for continuum mechanics problems is described. The procedure is used here to determine the critical layout of discontinuities and associated upper-bound limit load for plane plasticity problems. Potential discontinuities, which interlink nodes laid out over the body under consideration, are permitted to crossover one another giving a much wider search space than when such discontinuities are located only at the edges of finite elements of fixed topology. Highly efficient linear programming solvers can be employed when certain popular failure criteria are specified (e.g. Tresca or Mohr–Coulomb in plane strain). Stress/velocity singularities are automatically identified and visual interpretation of the output is straightforward. The procedure, coined ‘discontinuity layout optimization’ (DLO), is related to that used to identify the optimum layout of bars in trusses, with discontinuities (e.g. slip-lines) in a translational failure mechanism corresponding to bars in an optimum truss. Hence, a recently developed adaptive nodal connection strategy developed for truss layout optimization problems can advantageously be applied here. The procedure is used to identify critical translational failure mechanisms for selected metal forming and soil mechanics problems. Close agreement with the exact analytical solutions is obtained.
A characterization of optimal two-phase multifunctional composite designs
Authors: Silvestre Luis
Published: July 2007

We study the problem of optimal design of a two-phase composite material to maximize the sum of thermal and electrical conductivity. We obtain a characterization of an optimal configuration in terms of a free boundary type
H
problem. In the process of obtaining this result, we provide a new proof of the relevant case of Bergman's cross-property bound. We use our characterization to argue that the optimal interface is not, as has been suggested, a periodic minimal surface.
Bloch–Floquet bending waves in perforated thin plates
Authors: Movchan A.B , Movchan N.V , McPhedran R.C
Published: July 2007

This paper presents a mathematical model describing propagation of bending waves in a perforated thin plate. It is assumed that the holes are circular and form a doubly periodic square array. A spectral problem for the biharmonic operator is formulated in a unit cell containing a single defect, and its analytical solution is constructed using a multipole method. The overall system for the coefficients in the multipole expansion is then solved numerically. We generate dispersion diagrams for the two cases where the boundaries of holes are either clamped or free. We show that in the clamped case, there is a total low-frequency band gap in the limit of inclusions of zero radius, and give a simple formula describing the corresponding band diagram in this limit. We show that in the free-edge case, the band diagram of the vibrating plate is much closer to that of plane waves in a uniform plate than for the clamped case.
On the Riemann–Siegel formula
Authors: Kuznetsov A
Published: July 2007

In this article, we derive a generalization of the Riemann–Siegel asymptotic formula for the Riemann zeta function. By subtracting the singularities closest to the critical point, we obtain a significant reduction of the error term at the expense of a few evaluations of the error function. We illustrate the efficiency of this method by comparing it to the classical Riemann–Siegel formula.
Physical limitations on antennas of arbitrary shape
Authors: Gustafsson Mats , Sohl Christian , Kristensson Gerhard
Published: July 2007

In this paper, physical limitations on bandwidth, realized gain,
Q
-factor and directivity are derived for antennas of arbitrary shape. The product of bandwidth and realizable gain is shown to be bounded from above by the eigenvalues of the long-wavelength, high-contrast polarizability dyadics. These dyadics are proportional to the antenna volume and are easily determined for an arbitrary geometry. Ellipsoidal antenna volumes are analysed in detail, and numerical results for some generic geometries are presented. The theory is verified against the classical Chu limitations for spherical geometries and shown to yield sharper bounds for the ratio of the directivity and the
Q
-factor for non-spherical geometries.
Discovery of linear asymptotic behaviour at micro-Kelvin resolution in a modulated Rayleigh–Bénard chamber
Authors: van Putten Maurice H.P.M , van Putten Anton F.P
Published: July 2007

A new experiment is described on heat transfer in a Rayleigh–Bénard chamber modulated by an external flow. The results show a linear response of thermal gradients to small Reynolds numbers, here resolved with micro-Kelvin resolution at room temperature. It approaches a hyperbolic behaviour at large Reynolds numbers. This response is nowhere reminiscent of singular behaviour in boundary layer theory. It may, instead, represent a cellular model for describing heat transfer in porous media. An application to correlating residential gas-energy usage and local weather data is included.
Control of a highly pathogenic H5N1 avian influenza outbreak in the GB poultry flock
Authors: Truscott James , Garske Tini , Chis-Ster Irina , Guitian Javier , Pfeiffer Dirk , Snow Lucy , Wilesmith John , Ferguson Neil M , Ghani Azra C
Published: July 2007

The identification of H5N1 in domestic poultry in Europe has increased the risk of infection reaching most industrialized poultry populations. Here, using detailed data on the poultry population in Great Britain (GB), we show that currently planned interventions based on movement restrictions can be expected to control the majority of outbreaks. The probability that controls fail to keep an outbreak small only rises to significant levels if most transmission occurs via mechanisms which are both untraceable and largely independent of the local density of premises. We show that a predictor of the need to intensify control efforts in GB is whether an outbreak exceeds 20 infected premises. In such a scenario neither localized reactive vaccination nor localized culling are likely to have a substantial impact. The most effective of these contingent interventions are large radius (10 km) localized culling and national vaccination. However, the modest impact of these approaches must be balanced against their substantial inconvenience and cost.
A non-sperm transferring genital trait under sexual selection: an experimental approach
Authors: Nessler Stefan H , Uhl Gabriele , Schneider Jutta M
Published: July 2007

Male genitalia are among the fastest evolving morphological characters, and at a general level sexual selection seems to be involved. But experimental determination of the functions of many remarkable genitalic elaborations is very rare. Here we present the first study to address experimentally the adaptive function of a male genital structure that is not involved in sperm transfer. Females of the orb-weaving spiderArgiope bruennichiare sexually cannibalistic and polyandrous. The male increases his paternity by obstructing the female's insemination duct with a fragment of his complex genitalia (embolus tip). We manipulated males by detaching another species-specific structure, the median apophysis spur, and found that the spur promotes breakage of the embolus tip inside the female duct, but does not affect the probability and duration of copulation. These data are novel in that they suggest that a genitalic structure which does not transfer sperm nevertheless evolved in the context of sperm competition.
Singularity confinement for a class of
m
-th order difference equations of combinatorics
Authors: Adler Mark , van Moerbeke Pierre , Vanhaecke Pol
Published: July 2007

In a recent publication, it was shown that a large class of integrals over the unitary group

U

(
n
) satisfy nonlinear, non-autonomous difference equations over
n
, involving a finite number of steps; special cases are generating functions appearing in questions of the longest increasing subsequences in random permutations and words. The main result of the paper states that these difference equations have the
discrete Painlevé property
; roughly speaking, this means that after a finite number of steps the solution to these difference equations may develop a pole (Laurent solution), depending on the maximal number of free parameters, and immediately after be finite again (‘
singularity confinement
’). The technique used in the proof is based on an intimate relationship between the difference equations (discrete time) and the Toeplitz lattice (continuous time differential equations); the point is that the Painlevé property for the discrete relations is inherited from the Painlevé property of the (continuous) Toeplitz lattice.
Sex differences in the response to environmental cues regulating seasonal reproduction in birds
Authors: Ball Gregory F , Ketterson Ellen D
Published: July 2007

Although it is axiomatic that males and females differ in relation to many aspects of reproduction related to physiology, morphology and behaviour, relatively little is known about possible sex differences in the response to cues from the environment that control the timing of seasonal breeding. This review concerns the environmental regulation of seasonal reproduction in birds and how this process might differ between males and females. From an evolutionary perspective, the sexes can be expected to differ in the cues they use to time reproduction. Female reproductive fitness typically varies more as a function of fecundity selection, while male reproductive fitness varies more as a function sexual selection. Consequently, variation in the precision of the timing of egg laying is likely to have more serious fitness consequences for females than for males, while variation in the timing of recrudescence of the male testes and accompanying territory establishment and courtship are likely to have more serious fitness consequences for males. From the proximate perspective, sex differences in the control of reproduction could be regulated via the response to photoperiod or in the relative importance and action of supplementary factors (such as temperature, food supply, nesting sites and behavioural interactions) that adjust the timing of reproduction so that it is in step with local conditions. For example, there is clear evidence in several temperate zone avian species that females require both supplementary factors and long photoperiods in order for follicles to develop, while males can attain full gonadal size based on photoperiodic stimulation alone. The neuroendocrine basis of these sex differences is not well understood, though there are many candidate mechanisms in the brain as well as throughout the entire hypothalamo–pituitary–gonadal axis that might be important.
Adaptations to migration in birds: behavioural strategies, morphology and scaling effects
Authors: Hedenström Anders
Published: July 2007

The annual life cycle of many birds includes breeding, moult and migration. All these processes are time and energy consuming and the extent of investment in any one may compromise the others. The output from breeding is of course the ultimate goal for all birds, while the investment in moult and migration should be selected so that lifetime fitness is maximized. In particular, long-distance migrants breeding at high latitudes face severe time pressures, which is a probable reason why natural selection has evolved efficient behaviours, physiological and morphological adaptations allowing the maximum possible migration speed. Optimal migration theory commonly assumes time minimization as an overall strategy, but the minimization of energy cost and predation risk may also be involved. Based on these assumptions, it is possible to derive adaptive behaviours such as when and at which fuel load a stopover site should be abandoned. I review some core components of optimal migration theory together with some key predictions. A review of accumulated empirical tests of the departure rule indicates that time minimization is an important component of the overall migration strategy, and hence gives support to the assumption about time-selected migration. I also briefly discuss how the optimal policy may be implemented by the bird by applying a set of simple rules. The time constraints on migrants increase with increasing body size. Some consequences of this are discussed.
Seasonal changes in vertebrate immune activity: mediation by physiological trade-offs
Authors: Martin Lynn B , Weil Zachary M , Nelson Randy J
Published: July 2007

Animals living in temporally dynamic environments experience variation in resource availability, climate and threat of infection over the course of the year. Thus, to survive and reproduce successfully, these organisms must allocate resources among competing physiological systems in such a way as to maximize fitness in changing environments. Here, we review evidence supporting the hypothesis that physiological trade-offs, particularly those between the reproductive and immune systems, mediate part of the seasonal changes detected in the immune defences of many vertebrates. Abundant recent work has detected significant energetic and nutritional costs of immune defence. Sometimes these physiological costs are sufficiently large to affect fitness (e.g. reproductive output, growth or survival), indicating that selection for appropriate allocation strategies probably occurred in the past. Because hormones often orchestrate allocations among physiological systems, the endocrine mediators of seasonal changes in immune activity are discussed. Many hormones, including melatonin, glucocorticoids and androgens have extensive and consistent effects on the immune system, and they change in systematic fashions over the year. Finally, a modified framework within which to conduct future studies in ecological immunology is proposed, viz. a heightened appreciation of the complex but intelligible nature of the vertebrate immune system. Although other factors besides trade-offs undoubtedly influence seasonal variation in immune defence in animals, a growing literature supports a role for physiological trade-offs and the fitness consequences they sometimes produce.
Organization of vertebrate annual cycles: implications for control mechanisms
Authors: Wingfield John C
Published: July 2007

The majority of vertebrates have a life span of greater than one year. Therefore individuals must be able to adapt to the annual cycle of changing conditions by adjusting morphology, physiology and behaviour. Phenotypic flexibility, in which an individual switches from one life history stage to another, is one way to maximize fitness in a changing environment. When environmental variation is low, few life history stages are needed. If environmental variation is large, there are more life history stages. Each life history stage has a characteristic set of sub-stages that can be expressed in various combinations and patterns to determine state at any point in the life of the individual. Thus individuals have a finite number of states that can be expressed over the spectrum of environmental conditions in their life spans. Life history stages have three phases–development, mature capability (when characteristic sub-stages can be expressed) and termination. Expression of a stage is time dependent (probably a minimum of one month), and termination of one stage overlaps development of the next stage. It follows that the more life history stages an individual expresses, the less flexibility it will have in timing those stages. Having fewer life history stages increases flexibility in timing, but less tolerance of variation in environmental conditions. To varying degrees it is possible to overlap mature capability of some life history stages to effectively reduce ‘finite stage diversity’ and maximize flexibility in timing. Theoretical ways by which this can be done, and the implications for neuroendocrine and endocrine control mechanisms are discussed. Twelve testable hypotheses are posed that relate directly to control mechanisms.
Expression level of insulin‐like growth factor binding protein 5 mRNA is a prognostic factor for breast cancer
Authors: Li Xiaoqing , Cao Xuchen , Li Xi , Zhang Wei , Feng Yumei
Published: July 2007

The role of insulin‐like growth factor binding protein 5 (IGFBP5) in tumorigenesis and development of cancer is not well‐defined. IGFBP5 has been shown to either stimulate or inhibit cell proliferation via an IGF‐dependent mechanism and to promote cell proliferation and migration in an IGF‐independent manner. In the authors’ previous study, IGFBP5 was found to be significantly up‐regulated in lymph node metastases compared with their paired primary breast cancers. To further determine the role of IGFBP5 in breast cancer development and to evaluate its clinical significance in breast cancer, the mRNA expression level was detected in 30 normal breast tissues, 108 primary tumors, and 30 lymph node metastases using real time reverse transcription–polymerase chain reaction. The expression levels were correlated with several clinical parameters, including clinical stage, pathologic tumor size, axillary lymph node status, nuclear grade, estrogen receptor status, Her2 status, and local relapse or distant metastasis of the patients. As a result, the expression of IGFBP5 mRNA correlated positively with the invasion of axillary lymph nodes and the status of hormonal receptor. Furthermore, overexpression of IGFBP5 was associated with poor outcome of breast cancer patients with positive lymph nodes and negative ER. Thus, the expression level of IGFBP5 may contribute to the development of breast cancer and is a prognostic factor for breast cancer. (Cancer Sci 2007; 98: 1592–1596)
An international parentage and identification panel for the domestic cat (Felis catus)
Authors: Lipinski M. J. , Amigues Y. , Blasi M. , Broad T. E. , Cherbonnel C. , Cho G. J. , Corley S. , Daftari P. , Delattre D. R. , Dileanis S. , Flynn J. M. , Grattapaglia D. , Guthrie A. , Harper C. , Karttunen P. L. , Kimura H. , Lewis G. M. , Longeri M. , Meriaux J.‐C. , Morita M. , Morrin‐O'Donnell R. C. , Niini T. , Pedersen N. C. , Perrotta G. , Polli M. , Rittler S. , Schubbert R. , Strillacci M. G. , Van Haeringen H. , Van Haeringen W. , Lyons L. A.
Published: July 2007

Seventeen commercial and research laboratories participated in two comparison tests under the auspices of the International Society for Animal Genetics to develop an internationally tested, microsatellite‐based parentage and identification panel for the domestic cat (Felis catus). Genetic marker selection was based on the polymorphism information content and allele ranges from seven random‐bred populations (n = 261) from the USA, Europe and Brazil and eight breeds (n = 200) from the USA. Nineteen microsatellite markers were included in the comparison test and genotyped across the samples. Based on robustness and efficiency, nine autosomal microsatellite markers were ultimately selected as a single multiplex ‘core’ panel for cat identification and parentage testing. Most markers contained dinucleotide repeats. In addition to the autosomal markers, the panel included two gender‐specific markers, amelogenin and zinc‐finger XY, which produced genotypes for both the X and Y chromosomes. This international cat parentage and identification panel has a power of exclusion comparable to panels used in other species, ranging from 90.08% to 99.79% across breeds and 99.47% to 99.87% in random‐bred cat populations.
Aneuploidy and RAS mutations are mutually exclusive events in the development of well‐differentiated thyroid follicular tumours
Authors: Banito Ana , Pinto António E. , Espadinha Carla , Marques Ana Rita , Leite Valeriano
Published: July 2007

Objective  Follicular thyroid tumours present several genetic alterations such as aneuploidy, RAS mutations and PAX8/PPARγrearrangements. The molecular basis of aneuploidy remains undefined in the majority of human cancers. It has been proposed that mutations in RAS oncogenes could be related to chromosomal instability, although this issue remains controversial. The aim of our study was to investigate the correlation between aneuploidy, RAS mutations and PAX8/PPARγ gene rearrangement in thyroid follicular tumours.

Design  Ploidy status was determined by flow cytometry in 111 thyroid lesions (42 follicular thyroid adenomas, 27 follicular thyroid carcinomas, 19 follicular variants of papillary thyroid carcinoma, 20 poorly differentiated thyroid carcinomas and 3 anaplastic thyroid carcinomas). RAS mutations and PAX8/PPARγ fusion gene were investigated in 101 and 87 of these samples, respectively.

Results  Altogether, 12 of 50 (24%) diploid tumours presented RAS mutation which contrasts with 3 of 51 (5·9%; P = 0·0124) RAS mutations in the group of aneuploid tumours. The aneuploid tumours harbouring RAS mutations were two poorly differentiated carcinomas and one follicular variant of papillary thyroid carcinoma with poorly differentiated areas. None of the tumours with RAS mutations expressed the PAX8/PPARγ fusion gene. Three of five (60%) follicular thyroid adenomas and 1 of 7 (14%) follicular thyroid carcinomas, with the PAX8/PPARγ fusion gene, were aneuploid.

Conclusions  Our data suggest that aneuploidy and RAS mutations are mutually exclusive events in the development of well‐differentiated thyroid follicular tumours.
Similar clinical and laboratory findings in patients with symptomatic autosomal dominant and sporadic pseudohypoparathyroidism type Ib despite different epigenetic changes at the GNAS locus
Authors: Linglart Agnès , Bastepe Murat , Jüppner Harald
Published: July 2007

Objective  Most patients with autosomal dominant pseudohypoparathyroidism type Ib (AD‐PHP‐Ib) carry an identical maternally inherited 3‐kb microdeletion up‐stream of GNAS (STX16del4‐6mat), which is associated with a methylation loss restricted to exon A/B. STX16del4‐6mat is not found in sporadic PHP‐Ib (sporPHP‐Ib) patients, who show broad GNAS methylation changes. Because of the epigenetic differences between both groups, we searched for clinical and/or laboratory differences.

Patients and methods  Age at diagnosis, calcium, phosphorus and PTH were analysed in 43 patients with AD‐PHP‐Ib due to STX16del4‐6mat and in 22 patients with sporPHP‐Ib.

Results  All AD‐PHP‐Ib patients with STX16del4‐6mat showed only loss of exon A/B methylation. Of the 43 individuals, 26 were symptomatic when diagnosis was established at age 12·1 ± 1·34 years (mean ± SEM); laboratory findings at presentation were calcium 1·69 ± 0·06 mmol/l, phosphorus 2·25 ± 0·12 mmol/l and PTH 442 ± 54·1 pg/ml. The remaining 17 individuals with STX16del4‐6mat were asymptomatic when diagnosed at age 23·5 ± 3·93 years (calcium 2·18 ± 0·05 mmol/l, phosphorus 1·63 ± 0·10 mmol/l, PTH 222 ± 40·3 pg/ml). Patients with sporPHP‐Ib showed methylation changes at two or more GNAS exons, presented at age 10·0 ± 1·01 years and had, as a group, similar laboratory findings as patients with symptomatic AD‐PHP‐Ib (calcium 1·51 ± 0·06 mmol/l, phosphorus 2·65 ± 0·10 mmol/l, PTH 634 ± 162·1 pg/ml). However, sporPHP‐Ib females appeared to be more severely affected.

Conclusions  Patients with symptomatic AD‐PHP‐Ib due to STX16del4‐6mat and sporPHP‐Ib have similar changes in calcium, phosphate and PTH. STX16del4‐6mat often leads to asymptomatic disease and screening of all siblings of affected individuals is therefore advised. The cause of the apparent sexual dimorphism in patients with sporPHP‐Ib remains uncertain.
Asymptomatic hyperparathyroidism – need for multicentre studies
Authors: Mihai Radu , Wass John A. H. , Sadler Gregory P.
Published: July 2007

Long‐term follow‐up is initially considered appropriate for the majority of patients with primary hyperparathyroidism (PHPT) having small increases in calcium levels (< 2·8 mmol/l) and lacking the ‘classical’ symptoms of PHPT. The supportive reasoning is that many such patients never progress to more severe biochemical or clinical disease. There are, however, arguments in favour of early surgical treatment of such patients but adequately powered studies have not been carried out in this subgroup of patients to asses the impact of PHPT on their quality of life, cardiovascular risk and bone density.

Progressive loss in bone mineral density and an increased risk of bone fracture become increasingly significant in an ageing population. Left ventricular hypertrophy, an increased risk of arrhythmia and/or myocardial infarction in addition to changes in atherogenic lipid profile and impaired glucose tolerance may translate into an increased risk of premature death in this group of patients. Changes in the quality of life identified using standardized questionnaires are sometimes recognized by patients only in retrospect (i.e. after resolution of symptoms following successful parathyroidectomy). In addition, many series fail to assess and record accurately such symptoms.

Multicentre cohort studies of patients with asymptomatic PHPT randomized to immediate or delayed surgical treatment could address some of the debated issues highlighted in this review. Until such studies are set up, most surgeons would consider that parathyroid surgery should represent the first choice of treatment for all patients, but many physicians would favour a long‐term follow‐up. Nevertheless, the threshold for referral for surgical treatment has been lowered since the introduction of scan‐directed minimally invasive parathyroidectomy, which enables the experienced parathyroid surgeon to successfully treat patients with PHPT with a minimum of complications as a day‐case operation.

In the context of improved surgical treatment, we need more data on the benefits or otherwise in so‐called asymptomatic patients with a thorough assessment of their bone quality, cardiovascular risk and quality of life.