How much and for how long does the neonatal myocardium suffer from mild perinatal asphyxia?

Cardiac troponins can be useful in monitoring cardiac injury following perinatal distress. We report here an increase of cardiac troponin I (cTnI) to 2.84 microg/l at 3 weeks (age-related median: 0.07 microg/l) followed by normalization in a newborn with an uneventful clinical course after resuscitation at birth. Serial echocardiographs showed normal cardiac function. Such a time course of cTnI, not previously reported, could be due to either a greater sensitivity of biochemical markers than of instrumental tools or birth asphyxia. Larger studies are neede

Integrable systems without the Painlev\'e property

We examine whether the Painlev\'e property is a necessary condition for the integrability of nonlinear ordinary differential equations. We show that for a large class of linearisable systems this is not the case. In the discrete domain, we investigate whether the singularity confinement property is satisfied for the discrete analogues of the non-Painlev\'e continuous linearisable systems. We find that while these discrete systems are themselves linearisable, they possess nonconfined singularities

On positive solutions and the Omega limit set for a class of delay differential equations

This paper studies the positive solutions of a class of delay differential equations with two delays. These equations originate from the modeling of hematopoietic cell populations. We give a sufficient condition on the initial function for $t\leq 0$ such that the solution is positive for all time $t>0$. The condition is "optimal". We also discuss the long time behavior of these positive solutions through a dynamical system on the space of continuous functions. We give a characteristic description of the $\omega$ limit set of this dynamical system, which can provide informations about the long time behavior of positive solutions of the delay differential equation.Comment: 15 pages, 2 figure

Clustering of Cardiovascular Risk Factors Associated With the Insulin Resistance Syndrome

OBJECTIVE—Hyperinsulinemia is often associated with several metabolic abnormalities and increased blood pressure, which are risk factors for cardiovascular disease. It has been hypothesized that insulin resistance may underlie all these features. However, recent data suggest that some links between insulin resistance and these alterations may be indirect. The aim of our study was to further investigate this issue in a sample of young hyperandrogenic women, who often show insulin resistance and other metabolic abnormalities typical of the insulin resistance syndrome. RESEARCH DESIGN AND METHODS—We tested the hypothesis of a single factor underlying these features by principal component analysis, which should recognize one component if a single mechanism explains this association. The analysis was carried out in a sample of 255 young nondiabetic hyperandrogenic women. Variables selected for this analysis included the basic features of the insulin resistance syndrome and some endocrine parameters related to hyperandrogenism. RESULTS—Principal component analysis identified four separate factors, explaining 64.5% of the total variance in the data: the first included fasting and postchallenge insulin levels, BMI, triglycerides, HDL cholesterol, and uric acid; the second, BMI, blood pressure, and serum free testosterone; the third, fasting plasma glucose, postchallenge glucose and insulin levels, serum triglycerides, and free testosterone; and the fourth, postchallenge plasma insulin, serum free testosterone, and gonadotropin-releasing hormone agonist–stimulated 17-hydroxyprogesterone. CONCLUSIONS—These results support the hypothesis of multiple determinants in the clustering of abnormalities in the so-called insulin resistance syndrome

Trimester-specific reference intervals for thyroid function parameters in pregnant Caucasian women using Roche platforms: a prospective study

Background: Standard thyroid function parameters reference intervals (RI) are unsuitable during pregnancy, potentially resulting in incongruous treatments that may cause adverse effects on pregnancy outcomes. We aimed at defining trimester-specific TSH, FT4 and FT3 RI, using samples longitudinally collected from healthy Caucasian women. Materials and methods: Blood samples from 150 healthy Caucasian women, who had a physiological gestation and a healthy newborn at term, were collected in each trimester and at around six months post-partum. They showed mild iodine deficiency. After excluding women with overt TSH abnormalities (> 10 mU/L) and/or TPO antibodies, data from 139 pregnant women were analyzed by means of widely used Roche platforms, and TSH, FT4 and FT3 trimester-specific RI were calculated. Post-partum data were available for 55 subjects. Results: Serum TSH RI were 0.34-3.81 mU/L in the first trimester, and changed slightly to 0.68-4.07 U/L and 0.63-4.00 mU/L in the second and third trimester, respectively. Conversely, both FT4 and FT3 concentrations progressively decreased during pregnancy, the median values in the third trimester being 14.8% and 13.2% lower, respectively, than in the first trimester. Thyroid function parameters in the first trimester were similar to those measured after the end of pregnancy. Conclusions: This study calculates trimester-specific RI for thyroid function parameters in pregnancy, and proposes the reference limits that should be adopted when using Roche platforms in Caucasian women

On the Floquet Theory of Delay Differential Equations

We present an analytical approach to deal with nonlinear delay differential equations close to instabilities of time periodic reference states. To this end we start with approximately determining such reference states by extending the Poincar'e Lindstedt and the Shohat expansions which were originally developed for ordinary differential equations. Then we systematically elaborate a linear stability analysis around a time periodic reference state. This allows to approximately calculate the Floquet eigenvalues and their corresponding eigensolutions by using matrix valued continued fractions

A list of all integrable 2D homogeneous polynomial potentials with a polynomial integral of order at most 4 in the momenta

We searched integrable 2D homogeneous polynomial potential with a polynomial first integral by using the so-called direct method of searching for first integrals. We proved that there exist no polynomial first integrals which are genuinely cubic or quartic in the momenta if the degree of homogeneous polynomial potentials is greater than 4.Comment: 22 pages, no figures, to appear in J. Phys. A: Math. Ge

Transformée en ondelettes et modèles de Markov cachés pour la segmentation automatique du signal ECG

- Cette article présente une approche de segmentation automatique du signal ECG qui utilise la transformée en ondelettes et les modèles de Markov cachés (MMC). Le modèle MMC est la concaténation des modèles markoviens élémentaires de chaque onde P, QRS et T d'un battement cardiaque, permettant la détection de toutes ces ondes dans un signal ECG. Malgré la faible taille du corpus d'apprentissage, le MMC proposé montre une très bonne précision dans la segmentation des différents battements, comparée à 1 méthode classique. Le MMC a le grand avantage de s'adapter aux variations du signal ECG et surtout de faire de manière conjointe la détection du battement cardiaque et sa segmentation en ondes P, QRS et T

Égalisation par prédiction basée sur des réseaux de neurones et des fonctions objectifs obtenues à partir de la divergence de kullback-leibler et du constant modulus

Une structure de filtrage non linéaire pour l'égalisation aveugle est présentée. Cette structure est basée sur un réseau de neurones, ce qui permet l'inclusion de non linéarités dans la structure du filtre. D'autre part, la stratégie d'apprentissage du réseau est séparée en deux parties : une supervisée et l'autre auto-organisée. La divergence de Kullback-Leibler est utilisée comme base pour une fonction de coût d'une règle d'apprentissage auto-organisée, tandis que le critère du « constant modulus » est utilisé dans la partie supervisée. Les résultats des simulations comparent la performance de cette stratégie par rapport aux stratégies classiques d'égalisation adaptative. Les résultats montrent que, pour certains canaux, la stratégie proposée est plus performante que l'égaliseur à retour des décisions (DFE) supervisé

Prognostic role of serum concentrations of high-sensitivity C-reactive protein in patients with metastatic colorectal cancer: Results from the ITACa trial

Serum levels of C-reactive protein are (CRP) higher in patients with neoplastic conditions and numerous studies have been performed to clarify the etiologic and prognostic role of the high-sensitivity CRP (hs-CRP) in cancer. Our study was conducted on patients enrolled in the prospective randomized "Italian Trial in Advanced Colorectal Cancer (ITACa)" to assess hs-CRP levels and their impact on overall survival (OS) and progression-free survival (PFS). Serum samples from 132 ITACa patients were collected at baseline and 2 months after starting first-line chemotherapy. The supernatant was immediately transferred to cryovials and stored at -80°C. After thawing, hs-CRP was measured with the Cobas c501 analyzer. High levels of hs-CRP (≥ 13.1 mg/L) were associated with poorer median PFS (p < 0.0001) and OS (p < 0.0001) than low hs-CRP levels (< 13.1 mg/L). hs-CRP values in 107 patients were evaluated again after 2 months of therapy, revealing that patients with low hs-CRP levels in both baseline and second serum samples had the best median PFS and OS. Our study confirms the prognostic value of hs-CRP in patients with metastatic colorectal carcinoma