Treatment of patent ductus arteriosus (PDA) using ibuprofen: renal side-effects in VLBW and ELBW newborns

OBJECTIVES

This study aims to determine whether or not treatment of preterm neonates with PDA using IV ibuprofen can impair renal function and in what range of birth weights and gestational ages the risk of major renal side-effects due to ibuprofen is highest.

METHODS

134 preterm newborns with PDA were enrolled and randomized to receive either placebo or a 3-day-course (10, 5 and 5 mg/kg) of IV ibuprofen. 67 newborns (mGA: 27(+3) w and mBW: 989 g) with PDA received ibuprofen.

RESULTS

Subdividing the infants according to BW and to GA, the values of creatinine and BUN were only significantly higher than initial values at the end of the therapy in newborns with a BW ≤1000 g and/or GA ≤26 weeks. Renal impairment is greater the lower the weight and gestational age of the infant at birth.

CONCLUSIONS

Ibuprofen significantly impairs renal function in preterm infants with a GA ≤26 weeks and/or in ELBW neonates, while it may be considered safe for infants with a BW >1000 g and/or GA >26 weeks. Thus, before starting therapy with IV ibuprofen, it is essential to take into account the BW and GA of newborns and the effective need for treatment from the point of view of the ratio of risks to benefits, due to its substantial renal side-effects.

A dynamical population modeling of invasive species with reference to the crayfish Procambarus clarkii

In this paper we present a discrete dynamical population modeling of invasive species, with reference to the swamp crayfish Procambarus clarkii. Since this species can cause environmental damage of various kinds, it is necessary to evaluate its expected in not yet infested areas. A structured discrete model is built, taking into account all biological information we were able to find, including the environmental variability implemented by means of stochastic parameters (coefficients of fertility, death, etc.). This model is based on a structure with 7 age classes, i.e. a Leslie mathematical population modeling type and it is calibrated with laboratory data provided by the Department of Evolutionary Biology (DEB) of Florence (Italy). The model presents many interesting aspects: the population has a high initial growth, then it stabilizes similarly to the logistic growth, but then it exhibits oscillations (a kind of limit-cycle attractor in the phase plane). The sensitivity analysis shows a good resilience of the model and, for low values of reproductive female fraction, the fluctuations may eventually lead to the extinction of the species: this fact might be exploited as a controlling factor. Moreover, the probability of extinction is valuated with an inverse Gaussian that indicates a high resilience of the species, confirmed by experimental data and field observation: this species has diffused in Italy since 1989 and it has shown a natural tendency to grow. Finally, the spatial mobility is introduced in the model, simulating the movement of the crayfishes in a virtual lake of elliptical form by means of simple cinematic rules encouraging the movement towards the banks of the catchment (as it happens in reality) while a random walk is imposed when the banks are reached.

Increased risk of brain injury in IVF babies

AIM

The aim of this paper was to assess brain injury occurrence among in vitro fertilization (IVF) babies.

METHODS

We examined all babies born in our hospital in the triennium 2004-2006, comparing the presence of brain injuries between IVF babies and the rest of the population.

RESULTS

In IVF group (180 babies), brain injury was present in 4 babies, while in the rest of population (n=3602) it was present in 23 babies (P=0.042, RR: 3.18). IVF babies have a higher risk of being born with a birthweight less than 2 500 grams (P<0.0001; RR: 5.133). When we considered only babies born with a birth weight less than 2 500 grams, the difference of brain injury between the two groups was not significant.

CONCLUSION

In IVF babies, brain injury occurred more frequently than in the rest of population. This is probably due to a higher rate of premature births and low birth weight in IVF population. Anyway, this data should be disclosed to future parents to make an informed decision.

[Influence of prolonged treatment with octreotide on GH, IGF I, insulin, ACTH, cortisol, T3, T4 and TSH secretion in a case of congenital chylothorax]

Congenital chylothorax is a rare condition characterized by the accumulation of lymph fluid in the pleural space that causes respiratory and circulatory dysfunctions, immune deficiencies, hypoalbuminemia, electrolyte imbalance and alterations of the coagulation. Mortality rates are elevated and can rise to 50%. Therapy consists in conservative treatment based on thoracic drainage combined with total parenteral nutrition or use of low-fat high-protein diet supplemented with medium chain triglycerides. In case of failure surgical intervention may be considered. During the last years some authors have experienced the use of octreotide with doubtful results. In no case the drug impact on insulin, GH and cortisol secretion in neonatal age has been investigated and only in one case the effect on thyroid hormones has been assessed. We report the case of a 36-week baby with congenital chylothorax treated with octreotide for 42 days. The drug was well tolerated but hormonal level measurements showed a deep depression of insulin secretion unaccompanied by alterations of glucose levels. Levels of GH and TSH showed only a transitory decrease. ACTH and cortisol remained normal. At 5 months, the measurements of hormonal levels did not show significant alterations. It is not possible to determine if such a drug played an essential role in the solution of the pleural effusion, but it is important to emphasize that a prolonged treatment with octreotide has not caused, in our case, persistent hormonal alterations.

Aminoterminal B-type natriuretic peptide (NT-proBNP) in the therapy of patent ductus arteriosus

BACKGROUND

NT-proBNP is a reliable index in case of cardiac diseases.

OBJECTIVE

To evaluate the diagnostic usefulness of NT-proBNP as index of the closure of patent ductus arteriosus (PDA) in ELBW.

METHODS

Considered 73 ELBW (mGA 26+3 weeks; mBW 789 g) with echocardiographical diagnosis of PDA. The closure of the duct was spontaneous in 22%, pharmacological in 49.3% and by surgical ligation in 28.7%. Plasma NT-proBNP levels were measured on day 3 in 35 preterm infants; in 20 of them concentrations of the peptide were assayed on day 3 and on closure of the duct.

RESULTS

On day 3 the median of NT-proBNP levels was 13718 pg/ml (range 1918-70000). Peptide concentrations did not differ between pharmacological treatment and surgical ligation (respectively 13718 and 12342 pg/ml; p = 0.33). Concentrations of NT-proBNP were significantly lower on the closure of the duct (p < 0.0001) compared to concentrations on day 3 (median 12666 at day 3 versus 2443.5 pg/ml at closure), with a decrease of 80.71%.

CONCLUSIONS

ELBW showed high variability of NT-proBNP concentrations both on day 3 and on closure of PDA. Although NT-proBNP high levels were indicative of the presence of hsPDA, due to the extreme heterogeneity of the values it was not possible to determine an absolute cut-off concentration of NT-proBNP below which closure of the duct occurred, while a decrease of NT-proBNP > or =80% was a reliable index of PDA closure.

[Quantitative ultrasound for the assessment of bone in the preterm infant]

AIM

Preterm infants are at risk of osteopathy of prematurity (OP). The present study aims to assess quantitative ultrasound as a safe and non-invasive method in evaluating bone mineral status in the critically ill preterm infant.

METHODS

Sixty preterm infants (27 females) have been evaluated in the Neonatal Intensive Care Unit of the University Hospital of Siena. Gestational age was between 22 and 36 weeks and birth weight ranged between 610 and 3240 g. A single operator did all the measurements on the second metacarpus by the DBM Sonic BP (IGEA). Ultrasound parameters were bone transmission time (BTT, micros) and speed of sound (SOS, m/s).

RESULTS

BTT positively increased with birth gestational age (r=0.72, P<0.001, F-Ratio=62.4428), birth weight (r=0.7827, P<0.001, F-Ratio=91.7274) and birth length (r=0.7729, P<0.001, F-Ratio=86.0748). SOS was also related with gestational age (r=0.2937, P<0.023, F-Ratio=5.4768), birth weight (r=0.2634, P<0.042, F-Ratio=4.3250) and birth length (r=0.3252, P<0.011, F-Ratio=6.8596). Small infants for gestational age showed BTT values lower then infants with appropriate size for gestational age (P<0.03). There was no difference between male and female infants.

CONCLUSION

Quantitative ultrasound is a non-invasive method, which is easy to perform in a Neonatal Intensive Unit, safe, harmless and gentle. This method detects subtle differences in bone mineral status, according to gestational age, weight and length. Quantitative ultrasound is a useful screening tool for early detection of bone status in newborns and a valid method for the longitudinal assessment of bone in growing children.

[Survival rates in a single neonatal intensive care unit (period 2002-2007). Neuro-developmental outcome and survival for infants born at 23-25 weeks of gestation]

AIM

The aim of this study was to evaluate survival rates in a single Neonatal Intensive Care Unit (NICU) (period 2002-2007), with a special focus on the survival data and outcome at one-year of corrected age for infants born at 23-25 weeks of gestation.

METHODS

All infants who had evidence of heart activity at birth were actively resuscitated, regardless of birth weight or gestational age. Survival rate was calculated as a function of the following variables: birth weight and gestational category; gender in infants of birth weight < or = 1000 g ; appropriate (AGA) or small (SGA) weight for gestational age; inborn or outborn. Twenty-eight newborns (23-25 weeks of gestation) completed follow-up at one-year of corrected age.

RESULTS

During the examined period, no infants died in the delivery room; 833 newborns were admitted to the NICU. Overall survival rates were as following: <500 g (37%), 501-750 g (59%), 751-1,000 g (82%), 1,001-1,250 g (96%), 1251-1,500 g (97%), 1,501-2,000 g (100%), 2,001-2,500 g (98%), >2,500 g (99%); 23-25 weeks of gestation (50%); 26-27 weeks (77%), 28-32 weeks (90%); males < or = 1,000 g (68%), females < or = 1,000 g (68%); AGA < or = 1,000 g (63%), SGA < or = 1,000 g (79%), AGA < or =28 weeks (63%), SGA < or = 28 weeks (67%); inborn (54%), outborn (25%). A fraction of 64% (infants of 23-25 weeks of gestation) did not show handicap at one-year of corrected age, while 25% presented severe, 7% moderate, and 4% mild handicaps.

CONCLUSION

High rate of survival without handicap at one-year of corrected age at extremely low gestational age and the chance of improvements in neonatal care for newborn < or = 24 weeks, indicate the appropriateness for our strategy of resuscitating all newborns with evidence of heart activity in the delivery room.

[Insulin and glucagon plasma levels in very low birth weight preterm infants of appropriate weight for gestational age]

OBJECTIVES

Prematurity is a known risk factor for hypoglycaemia, hyperglycemia, neonatal sepsis and other common neonatal complications, possibly associated with glucoregolatory hormone (insulin and glucagon) alterations. Insulin and glucagon levels change also in relation to gender, mode of delivery and postnatal clinical severity. Because of the lack of reference range in literature, the aim of this study is to assess plasma insulin and glucagon levels in preterm appropriate for gestational age (AGA) infants of birth weight <1500 g (very low birth weight, VLBW) as a function of gestation, birth weight, gender and mode delivery.

METHODS

The authors examined 48 preterm AGA infants (mean birth weight 1 163+/-286 g, mean gestational age 28.2+/-2.4 weeks). The infant population was subdivided in relation to gestational age, weight, gender, mode of delivery and assisted ventilation at 5-7(th) days. Plasma glucose, insulin and glucagon levels were assessed in all newborns at birth and at 5-7(th) days of life. Data were analyzed using t-test.

RESULTS

A negative correlation between insulin and gestational age was observed (P<0.05). At birth, no significant differences regarding plasma glucose, insulin and glucagon levels were observed as a function of the examined category variables. At the 5-7(th) days of life, insulin levels were significantly higher in newborns with gestational age =or<27 weeks (P<0.02), in the female gender (P<0.02) and in the infants born to emergency Cesarean delivery (P<0.05).

CONCLUSIONS

These findings indicate potentially useful reference range values for plasma insulin and glucagon in the VLBW population.

Is Cupressus sempervirens native in Italy? An answer from genetic and palaeobotanical data

This study represents the first large-scale analysis using nuclear molecular markers to assess genetic diversity and structure of Cupressus sempervirens L.. Genetic and fossil data were combined to infer the possible role of human activity and evolutionary history in shaping the diversity of cypress populations. We analysed 30 populations with six polymorphic nuclear microsatellite markers. Dramatic reductions in heterozygosity and allelic richness were observed from east to west across the species range. Structure analysis assigned individuals to two main groups separating central Mediterranean and eastern populations. The two main groups could be further divided into five subgroups which showed the following geographical distributions: Turkey with the Greek islands Rhodes and Samos, Greece (Crete), Southern Italy, Northern Italy, Tunisia with Central Italy. This pattern of genetic structure is also supported by SAMOVA and Barrier analyses. Palaeobotanical data indicated that Cupressus was present in Italy in the Pliocene, Pleistocene and Holocene. Furthermore, our molecular survey showed that Italian cypress populations experienced bottlenecks that resulted in reduced genetic diversity and allelic richness and greater genetic differentiation. Recent colonization or introduction may also have influenced levels of diversity detected in the Italian populations, as most individuals found in this range today have multilocus genotypes that are also present in the eastern range of the species. The data reveal a new interpretation of the history of cypress distribution characterized by ancient eastern populations (Turkey and Greek islands) and a mosaic of recently introduced trees and remnants of ancient, depauperate populations in the central Mediterranean range.

Thermodynamic entropy and chaos in a discrete hydrodynamical system

We show that the thermodynamic entropy density is proportional to the largest Lyapunov exponent (LLE) of a discrete hydrodynamical system, a deterministic two-dimensional lattice gas automaton. The definition of the LLE for cellular automata is based on the concept of Boolean derivatives and is formally equivalent to that of continuous dynamical systems. This relation is justified using a Markovian model. In an irreversible process with an initial density difference between both halves of the system, we find that Boltzmann's H function is linearly related to the expansion factor of the LLE although the latter is more sensitive to the presence of traveling waves.

Pervasive technology in Neonatal Intensive Care Unit: a prototype for newborns unobtrusive monitoring

Pervasive computing research is introducing new perspectives in a wide range of applications, including healthcare domain. In this study we explore the possibility to realize a prototype of a system for unobtrusive recording and monitoring of multiple biological parameters on premature newborns hospitalized in the Neonatal Intensive Care Unit (NICU). It consists of three different units: a sensitized belt for Electrocardiogram (ECG) and chest dilatation monitoring, augmented with extrinsic transducers for temperature and respiratory activity measure, a device for signals pre-processing, sampling and transmission through Bluetooth(R) (BT) technology to a remote PC station and a software for data capture and post-processing. Preliminary results obtained by monitoring babies just discharged from the ward demonstrated the feasibility of the unobtrusive monitoring on this kind of subjects and open a new scenario for premature newborns monitoring and developmental cares practice in NICU.

Risk perception in epidemic modeling

We investigate the effects of risk perception in a simple model of epidemic spreading. We assume that the perception of the risk of being infected depends on the fraction of neighbors that are ill. The effect of this factor is to decrease the infectivity, that therefore becomes a dynamical component of the model. We study the problem in the mean-field approximation and by numerical simulations for regular, random, and scale-free networks. We show that for homogeneous and random networks, there is always a value of perception that stops the epidemics. In the "worst-case" scenario of a scale-free network with diverging input connectivity, a linear perception cannot stop the epidemics; however, we show that a nonlinear increase of the perception risk may lead to the extinction of the disease. This transition is discontinuous, and is not predicted by the mean-field analysis.

Dynamical affinity in opinion dynamics modeling

We propose here a model to simulate the process of opinion formation, which accounts for the mutual affinity between interacting agents. Opinion and affinity evolve self-consistently, manifesting a highly nontrivial interplay. A continuous transition is found between single and multiple opinion states. Fractal dimension and signature of critical behavior are also reported. A rich phenomenology is presented and discussed with reference to corresponding psychological implications.

RrgA is a pilus-associated adhesin in Streptococcus pneumoniae

Adherence to host cells is important in microbial colonization of a mucosal surface, and Streptococcus pneumoniae adherence was significantly enhanced by expression of an extracellular pilus composed of three subunits, RrgA, RrgB and RrgC. We sought to determine which subunit(s) confers adherence. Bacteria deficient in RrgA are significantly less adherent than wild-type organisms, while overexpression of RrgA enhances adherence. Recombinant monomeric RrgA binds to respiratory cells, as does RrgC with less affinity, and pre-incubation of epithelial cells with RrgA reduces adherence of wild-type piliated pneumococci. Non-adherent RrgA-negative, RrgB- and RrgC-positive organisms produce pili, suggesting that pilus-mediated adherence is due to expression of RrgA, rather than the pilus backbone itself. In contrast, RrgA-positive strains with disrupted rrgB and rrgC genes exhibit wild-type adherence despite failure to produce pili by Western blot or immunoelectron microscopy. The density of bacteria colonizing the upper respiratory tract of mice inoculated with piliated RrgA-negative pneumococci was significantly less compared with wild-type; in contrast, non-piliated pneumococci expressing non-polymeric RrgA had similar numbers of bacteria in the nasopharynx as piliated wild-type bacteria. These data suggest that RrgA is central in pilus-mediated adherence and disease, even in the absence of polymeric pilus production.

Modeling HIV quasispecies evolutionary dynamics

BACKGROUND

During the HIV infection several quasispecies of the virus arise, which are able to use different coreceptors, in particular the CCR5 and CXCR4 coreceptors (R5 and X4 phenotypes, respectively). The switch in coreceptor usage has been correlated with a faster progression of the disease to the AIDS phase. As several pharmaceutical companies are starting large phase III trials for R5 and X4 drugs, models are needed to predict the co-evolutionary and competitive dynamics of virus strains.

RESULTS

We present a model of HIV early infection which describes the dynamics of R5 quasispecies and a model of HIV late infection which describes the R5 to X4 switch. We report the following findings: after superinfection (multiple infections at different times) or coinfection (simultaneous infection by different strains), quasispecies dynamics has time scales of several months and becomes even slower at low number of CD4+ T cells. Phylogenetic inference of chemokine receptors suggests that viral mutational pathway may generate a large variety of R5 variants able to interact with chemokine receptors different from CXCR4. The decrease of CD4+ T cells, during AIDS late stage, can be described taking into account the X4-related Tumor Necrosis Factor dynamics.

CONCLUSION

The results of this study bridge the gap between the within-patient and the inter-patients (i.e. world-wide) evolutionary processes during HIV infection and may represent a framework relevant for modeling vaccination and therapy.

Inter-observer reliability of two pain scales for newborns

AIM

To assess inter-observer reliability of two of the most widely used pain scales for newborns.

BACKGROUND

More than 30 scales exist to assess neonatal pain, but they are rarely used because they are too complicated or unreliable.

METHOD

We scored pain level in two groups of babies during a heelprick. The first group of 20 premature babies (mean gestational age: 34.2+/-1.2 weeks) was studied using the PIPP scale, and the second group of 20 term babies (mean gestational age: 39.5+/-0.9 weeks) with the NIPS scale. We compared the pain scores assigned by the nurse who took the blood sample (nurse A) and those assigned by another who was present during heelprick (nurse B) with those assigned by a nurse who later watched the video clip of the procedure (nurse C). We chose the latter as "objective" score, because in this case the scorer could watch the recorded event several times, timing and scoring it thoroughly.

FINDING

NIPS: 8/20 scores were different between nurse A and nurse C, but only in one case was this difference greater than 2 (Cohen's K=0.60). In the case of nurse B, there were 12/20 differences with respect to the score assigned by nurse C but only one baby was assigned a score that differed by more than 2 (Cohen's K=0.30). PIPP: 16/20 scores were different between nurse A and nurse C; in 9 cases this difference was more than 2 (Cohen's K=0.10). In the case of nurse B, differences with respect to the score assigned by nurse C occurred in 17/20 cases and for six babies the difference in score was more than 2 (Cohen's K=0.16).

CONCLUSION

Our results indicate a higher inter-observer reliability of NIPS than PIPP, though NIPS did not have a very high inter-observer agreement score. Caregivers who use them to assess pain in real time at the cribside should be aware of the limits we have highlighted in this study.

High maternal and fetal plasma urocortin levels in pregnancies complicated by hypertension

OBJECTIVE

We evaluated maternal and fetal plasma levels and placental mRNA expression of urocortin, a placental vasoactive neuropeptide, in singleton pregnancies (n = 70) complicated by hypertensive disorders classified as gestational hypertension (n = 36), pre-eclampsia (n = 19), and pre-eclampsia complicated by intrauterine growth restriction (PE/IUGR, n = 15), and in 70 healthy normotensive singleton pregnancies.

METHODS

Plasma levels were assayed by radioimmunoassay, fetal biometry by ultrasound scans, utero-placental and fetal perfusion by Doppler velocimetry, and placental urocortin mRNA expression by quantitative real time reverse transcriptase-polymerase chain reaction. The main outcome measures were the correlation of urocortin concentrations with patterns of the utero-placental and fetal circulation, and the early prediction of a poor neonatal outcome such as the occurrence of perinatal death and intraventricular hemorrhage.

RESULTS

Maternal and fetal urocortin levels were significantly (both P < 0.001) higher in gestational hypertension, pre-eclampsia and PE/IUGR women than in controls, and correlated with Doppler velocimetry patterns. Fetal concentrations were significantly (P < 0.0001) higher than and significantly (P < 0.0001) correlated to maternal levels. Placental mRNA expression did not change. Ten out of 140 newborns had a poor neonatal outcome, with an overall prevalence of 7.14% (pretest probability). Using the receiver operator characteristics curve analysis cut-off values, the probability of a poor neonatal outcome was 66.7% when urocortin was used, and was 0% if levels were unaltered.

CONCLUSIONS

Maternal and fetal urocortin levels are increased in hypertensive disorders of pregnancy. Since urocortin has vasoactive properties, the evidence of increased urocortin levels in hypertensive disorders may represent an adaptive fetal response.

A toy model of polymer stretching

We present an extremely simplified model of multiple-domain polymer stretching in an atomic force microscopy experiment. We portray each module as a binary set of contacts and decompose the system energy into a harmonic term (the cantilever) and long-range interaction terms inside each domain. Exact equilibrium computations and Monte Carlo simulations qualitatively reproduce the experimental sawtooth pattern of force-extension profiles, corresponding (in our model) to first-order phase transitions. We study the influence of the coupling induced by the cantilever and the pulling speed on the relative heights of the force peaks. The results suggest that the increasing height of the critical force for subsequent unfolding events is an out-of-equilibrium effect due to a finite pulling speed. The dependence of the average unfolding force on the pulling speed is shown to reproduce the experimental logarithmic law.

Umbilical Cord Serum Activin A Levels are Increased in Pre-eclampsia with Impaired Blood Flow in the Uteroplacental and Fetal Circulation

The aims of the present study were to evaluate the umbilical cord serum activin A concentrations in complicated pregnancies and also to explore the relationship between activin A levels and blood flow velocity in fetal arteries. Umbilical cord blood samples were obtained postpartum after a full term uneventful gestation (control group, n=40), and from pregnancies complicated by gestational diabetes (n=13), preterm labour (n=18), or pre-eclampsia (n=19). Cord serum activin A levels were three-fold higher in pregnancies complicated by pre-eclampsia (1.17+/-0.14 ng/ml, p<0.01) than in the control group (0.43+/-0.03 ng/ml), but were unaltered in the diabetes and preterm labour groups. The pre-eclampsia group had a marked increase of umbilical artery pulsatility index (PI) and also a decrease of middle cerebral artery PI (p<0.01). Furthermore, activin A concentration correlated directly with the umbilical artery PI (r=0.540, p=0.021), with the length of stay in the Neonatal Intensive Care Unit (r=0.857, p<0.001) and also with cord blood pH (r=-0.886, p<0.001). In conclusion, umbilical cord serum activin A levels are increased in the presence of pre-eclampsia and provide an indirect marker of impaired blood flow in the uteroplacental and fetal circulation.

Transient hypothyroxinemia of prematurity and histological chorioamnionitis

BACKGROUND

Transient hypothyroxinaemia of prematurity (THOP) is a common condition of preterm infants whose causes remain unclear. We tested the hypothesis that THOP is associated with histological chorioamnionitis (HCA).

METHODS

Whole blood T4 and TSH concentrations on day 4 and at 40 weeks' postmenstrual age (rtx-T4 and rtx-TSH), placental histology and illness severity were prospectively evaluated in 155 very low birth weight (VLBW) infants.

RESULTS

HCA-positive infants showed significantly decreased blood total T4 concentrations on day 4, as compared to the HCA-negative population (P<0.0001), along with comparable TSH, rtx-T4, and rtx-TSH blood concentrations. None of the infants showed evidence of hypothyroidism during the study. A total T4 < or = 4.4 microg/dL on postnatal day 4 identified HCA-positive newborns with 90.8%, sensitivity, 94.7%, specificity, 96.7% positive predictive and 85.7% negative predictive values. HCA (OR: 32.19; 95% CI: 8.95-115.64), birth weight < or = 880 g (OR: 4.1; 1.15-14.64), and RDS (OR: 3.71, 95% CI: 1.13-12.25) were independently associated with evidence of hypothyroxinaemia on day 4.

CONCLUSION

Our findings indicate a previously un-recognized relationship between HCA and THOP, hence suggesting a predominant role for a fetal systemic inflammatory response syndrome in the pathogenesis of THOP.

Synchronization universality classes and stability of smooth coupled map lattices

We study two problems related to spatially extended systems: the dynamical stability and the universality classes of the replica synchronization transition. We use a simple model of one-dimensional coupled map lattices and show that chaotic behavior implies that the synchronization transition belongs to the multiplicative noise universality class, while stable chaos implies that the synchronization transition belongs to the directed percolation universality class.

Development and validation of the ABC pain scale for healthy full-term babies

AIM

We developed and validated a pain scale (ABC scale) for term babies based on acoustic features of crying.

METHODS

The scale consisted of three different cry parameters: (a) pitch of the first cry; (b) rhythmicity of the crying bout; (c) constancy of crying intensity. These parameters were previously found to distinguish between medium and high levels of pain measured by spectral analysis of crying. We validated the scale using healthy term babies undergoing routine heel prick. Concurrent validity was assessed comparing pain values obtained with our scale with those obtained with another pain scale; this relationship was also used to assess the sensitivity of the scale. To assess specificity we compared the ABC scores during a painful event (heel prick) with two non-painful events (preliminary phase of prick in the same group of babies, and heel prick with analgesia in another group).

RESULTS

Specificity: (a) analgesic/non-analgesic comparison, p < 0.0001; (b) pain/sham comparison, p < 0.0001). Sensitivity: a high correlation between scores of the ABC scale and the Douleur Aigue du Nouveau-Né scale indicates good sensitivity. Concurrent validity: Spearman rho = 0.91. Internal consistency: Cronbach's alpha = 0.76. Inter-rater reliability: Cohen's kappa for multiple raters = 0.83. Intra-rater reliability: Cohen's kappa = 0.85. Practicality: All nurses who used it scored the scale as "good".

CONCLUSION

The ABC scale proved to be simple and reliable for assessing pain in healthy, non-intubated term newborns.

Is an excessive number of prenatal echographies a risk for fetal growth?

AIM

To assess whether a very high number of prenatal ultrasonographies affects birthweight.

POPULATION AND METHODS

We studied 1203 consecutive women who delivered in Siena Hospital. Exclusion criteria were the following: twin pregnancy, maternal smoke or alcohol ingestion in pregnancy, gestational diabetes, placenta or umbilical cord defects, gestational age at birth <37 weeks, and major malformations. We analysed birthweights in relation to the number of ultrasound examinations. 120 women had undergone a minimum number (three or less-base group) and 167 a maximum number (nine or more-intensive group) of fetal US scans. We compared the birthweight of the children born in these two groups and the correlation between number of US scans and birthweight in the whole population.

RESULTS

Mean birthweights of the base and the intensive groups were 3389.5+/-434 g and 3268+/-438 g, respectively (p=0.0206). Nevertheless, the regression study did not show a significant correlation between birthweight and number of US scans. The mean age of the base group was 30.1+/-5.3 years and that of the intensive group was 32.09+/-4.99 years (p=0.0018). Eighteen women of base group underwent amniocenteses vs. 71 in the intensive group (p<0.001). In the base group 57.5% of the mothers had low school level vs. 24.4% in the intensive group (p<0.01).

CONCLUSION

More studies are needed to confirm or exclude any relationship between an intensive use of prenatal ultrasounds and birthweight, and to exclude other effects of ultrasounds on children's health. Moreover, our study shows an excess of prenatal diagnostic procedures, the causes of which should be investigated.