Ante partum bed rest and unexplained infantile crying

AIM

The aim of this study was to assess whether bed rest during pregnancy is a risk factor for infantile colics.

METHODS

In a previous paper a questionnaire was administered to 86 women (43 of whom had stayed in bed during pregnancy for a mean of 3.4+/-1.2 months, and 43 were controls) about the clinical history and the present state of their 11-15 year old babies. In the present paper we traced these women and assessed the presence/absence of unexplained infant crying (UIC, infantile colic), diagnosed by a physician in the first year of life of these children. Forty mothers answered the inquiry, and we compared their answers with 40 control mothers.

RESULTS

Babies born after maternal bed rest during pregnancy had a higher incidence of UIC than the control group (26/40 vs 11/40; P=0.0015). No significant correlation was found between UIC and allergies or between UIC and maternal or artificial breast feeding.

CONCLUSIONS

Our retrospective study shows a possible association between bed rest and UIC: further studies, including other important variables (stress, drugs, smoking) are needed.

Blink-startle reflex habituation in 30-34-week low-risk fetuses

OBJECTIVE

To investigate whether the blink-startle reflex (BSR) is a good marker of habituation to vibroacoustic stimulation in healthy preterm fetuses.

MATERIALS AND METHODS

A total of 22 women with uncomplicated pregnancies at 30-34 weeks participated in the study. Vibroacoustic stimulus was repeatedly applied to the maternal abdomen above the fetal head for a period of 2 s every 10 s. Fetal eye tightening monitored by ultrasound within 2 s of the stimulus was considered a positive response. The habituation rate was defined as the number of stimuli applied before the fetus stopped responding to two consecutive stimuli. Results were compared using the Mann-Whitney U-test.

RESULTS

All 22 fetuses showed habituation at a rate that varied from 1 to 9 (mean 4.2+/-1.8).

CONCLUSION

BSR is a good marker of habituation in preterm fetuses. Further study is needed to ascertain whether abnormal BSR habituation could be a sign of fetal distress.

Histologic chorioamnionitis and severity of illness in very low birth weight newborns

OBJECTIVE

Estimating the risk of in-hospital mortality in the neonatal intensive care unit provides important information for health care providers, and several neonatal illness severity scores have been developed. Histologic chorioamnionitis (HCA) is a known cause of neonatal morbidity and mortality. To date, the relationship between HCA and neonatal illness severity scores has not been rigorously tested. In this study, the relationships among HCA, initial illness severity, and neonatal outcomes were analyzed in very low birth weight (VLBW) newborns admitted to the neonatal intensive care unit.

DESIGN

Prospective.

SETTING

Neonatal intensive care unit.

PATIENTS

A total of 116 VLBW inborn infants (gestational age, 28.1 +/- 2.82 wks; birth weight, 1009 +/- 312 g) were categorized as HCA-positive (n = 67) and HCA-negative (n = 49).

INTERVENTIONS

Placental histology was performed to identify HCA. Illness severity evaluation included several different neonatal illness severity scores-Clinical Risk Index for Babies (CRIB), CRIB-II, Score for Neonatal Acute Physiology-II (SNAP-II), and Score for Neonatal Acute Physiology Perinatal Extension-II (SNAPPE-II)-as well as the recording of severe morbidity and in-hospital mortality.

MEASUREMENTS AND MAIN RESULTS

HCA-positive VLBW newborns showed significantly lower gestational age (p < .0001) and birth weight (p = .0010), together with higher CRIB, CRIB-II, SNAP-II, and SNAPPE-II scores at admission to the NICU (p </= .0001) and mortality rate (p = .0018) than HCA-negative infants. After adjustment for gender and gestational age in a multivariable logistic regression analysis, HCA was found to be an independent predictor of high illness severity: CRIB > 5 (odds ratio [OR], 21.37; 95% confidence interval [CI], 6.24-73.21); CRIB-II > 10 (OR, 56.17; 95% CI, 6.75-467.2); SNAP-II > 22 (OR, 43.05; 95% CI, 11.9-155.7), and SNAPPE-II > 42 (OR, 48.95; 95% CI, 10.18-235.4) (all p values <.0001).

CONCLUSIONS

Our findings indicate that HCA is a major predictor of morbidity and mortality in VLBW newborns.

Phase transitions of extended-range probabilistic cellular automata with two absorbing states

We study phase transitions in a long-range one-dimensional cellular automaton with two symmetric absorbing states. It includes and extends several other models, like the Ising and Domany-Kinzel ones. It is characterized by competing ferromagnetic linear and antiferromagnetic nonlinear couplings. Despite its simplicity, this model exhibits an extremely rich phase diagram. We present numerical results and mean-field approximations.

Reduction of exposure of newborns and caregivers to very high electromagnetic fields produced by incubators

The aims of this paper is to measure whether ferromagnetic panels sufficiently reduce the high electromagnetic fields (EMF) to which newborns are exposed in incubators and to which caregivers are exposed when working near the incubators. We measured EMF at mattress level in three neonatal incubators with and without ferromagnetic panels between the electric motor and the mattress. We then measured the EMF at the level of the maximum emission point for caregivers, i.e., near the display panel. The ferromagnetic panels were (a) 5 mm thick iron, (b), (c), (d) respectively, one, two, and three sheets of 0.3 mm thick mu-metal. The weight of iron sheet was 4 g/cm2, and mu-metal 0.2 g/cm2. The use of the ferromagnetic panels significantly reduced the EMF. No significant difference in attenuation was recorded using one, two, or, three sheets of mu-metal, or a single sheet of iron. One, two, and three sheets of mu-metal reduced EMFs by 77%, 82%, and 84.3%, respectively; the reduction with iron was 80%. EMF values measured in incubators were higher than those to which the general population is exposed. The use of ferromagnetic panels significantly reduces the level of EMFs to which neonates and caregivers are exposed.

Skin reflectance changes in preterm infants with patent ductus arteriosus

INTRODUCTION

Patent ductus arteriosus (PDA) is a common complication in preterm infants. While two-dimensional echocardiography is the method of choice for diagnosing a PDA, clinical signs are known to be of limited value.

STUDY DESIGN

Haemodynamically significant PDA (hs-PDA) was defined as a ductal left-to-right shunt with elevated left atrial/aortic root ratio ( > 1.6:1), a ductal diameter > 2 mm, retrograde diastolic flow exceeding 30% of the anterograde flow and anterograde peak diastolic flow velocity in left pulmonary artery > 50 cm/s. A hs-PDA may affect the cerebral circulation and skin color is known to be related to local perfusion. In this study, we tested the value of a caudal-to-cephalic skin reflectance differential in detecting preterm infants with hs-PDA. The study was blinded and prospective.

SUBJECTS

Fifteen infants with a hs-PDA (M: 8, F: 7; gestational age: 28.0 +/- 2.0 weeks, birth weight: 880 +/- 130 g) and 15 gender- and gestational age-matched infants without a haemodynamically significant PDA (M: 8, F: 7; gestational age: 28.2 +/- 2.3 weeks, birth weight: 885 +/- 135 g) participated to the study.

OUTCOME MEASURE

Skin reflectance measurements were performed using a reflectance spectrophotometer (CM-2600d/2500d, Minolta, Osaka, Japan). Sole ("postductal" site) to forehead ("preductal" site) skin reflectance ratio (caudal-to-cephalic ratio).

RESULTS

hs-PDA infants showed significantly lower forehead light reflectance values on for the whole visible spectrum (p < or = 0.043) with the exception of 580-590 nm (p = 0.058), whereas no statistically significant differences were observed for the sole skin reflectance between the two groups in the examined visible spectrum. Consequently, hs-PDA infants showed a significantly higher caudal to cephalic ratio in the 410-430 nm (p < or = 0.042), 460-530 nm (p < or = 0.027) and 590-700 nm (p < or = 0.011) wavelength ranges.

CONCLUSIONS

These findings may provide a previously unrecognised clinical marker for haemodynamically significant PDA in preterm infants, thus predicting those preterm infants who may require intervention for PDA.

11- to 15-Year-old children of women who danced during their pregnancy

AIM

To determine whether high levels of maternal physical activity (dancing during pregnancy), influenced the offspring.

MATERIALS AND METHODS

Sixty-four women (32 of whom had continued to dance for at least 2 months after the beginning of pregnancy) filled in a questionnaire to assess the health and behavior of their offspring, now 11-15 years of age.

RESULTS

More children born from women who had continued to dance during pregnancy needed to be rocked to sleep during their first year (p < 0.05). More children in the study group played musical instruments (p < 0.05). There were no significant differences between the groups regarding other parameters.

CONCLUSIONS

The greater need to be rocked to fall asleep and the attitude to play musical instruments recorded in the children of dancers may be related to prenatal maternal movement. But they may also be due to other causes as discussed.

[Vibration risk during neonatal transport]

AIM

The aim of this paper is to assess the entity of the mechanical vibrations which newborn and medical staff are exposed to and to evaluate the possible risks connected with excessive exposure.

METHODS

Vibrations during a simulated emergency ambulance transport were studied. Vibration values with an accelerometer at the level of the incubator's mattress and at passengers' and pilot's seat level were measured. Mean accelerations (awz) and peak accelerations (awpeak), measured using a ponderation filter, according with ISO standard 2631, were considered.

RESULTS

Inside the incubator an acceleration mean value of 1.33 (+/-0.13) m/s(2) and peak values of 11.8 (+/-0.1) m/s(2) were found. On passengers' seats the awz findings were 0.55 m/s(2) (+/-0.13) and 0.56 m/s(2) (+/-0.08) while awpeak respectively 4.8 m/s(2) (+/-0.1) and 10.2 m/s(2) (+/-0.1). On pilot's seat a mean acceleration of 0.48 m/s(2) (+/-0.08) and an awpeak value of 4.5 m/s(2) (+/-0.1) were found.

CONCLUSION

Peak vibration values which newborns are exposed to (11.8 m/s(2)) are high, when compared with acceleration of gravity (9.8 m/s(2)); this can provoke repeated jerks. Environmental stress can easily alter the stability of an ill newborn and interfere with care manoeuvres. Decreasing vibrations in neonatal transport unit could increase the safety of newborns, reducing the risks which newborns are actually exposed to.

Long-term effects of antepartum bed rest on offspring

We studied the children of mothers who were confined to bed during pregnancy for more than 15 consecutive days (mean 3.69 months) in the years 1986-1990 (bed rest offspring; BRO). We studied 86 children: 43 BRO and 43 control children. Data were obtained by means of a 20-item questionnaire filled in by the mothers. The BRO group differed from the control group in incidence of allergies (p = 0.005), motion sickness (p = 0.03), and need to be rocked to fall asleep (p = 0.01). More BRO born at term than controls played musical instruments later in life. Two possible explanations for more allergies among the BRO group are the use of beta-stimulating drugs against premature delivery and the effects of prolonged stress on the developing immune system. Understimulation of the developing vestibular system during gestation may affect some aspects of its development and may explain the higher incidence of motion sickness and need for vigorous rocking in BRO.

Use of Sound-Absorbing Panel to Reduce Noisy Incubator Reverberating Effects

OBJECTIVES

To assess the amplification and distortion of noise in incubators by measuring noise levels from various sources under various conditions.

STUDY DESIGN

We recorded sound pressure levels (SPL) of background noise, baby crying, alarms and porthole closing with the incubator hood open or closed. Then we tried to reduce the sound level in the incubator by applying a sound absorbing panel to the ceiling of the hood.

RESULTS

The sound sources analysed produced very high SPL. In free field baby crying and porthole noise were, respectively, 81-83 dB and 70-71 dB, closing the hood they raised to 84-87 and 73-74 dB: this means that the noise perceived by a baby in the incubator had twice the SPL of the same noise emitted in a free field; alarm noise was 56-57 dB inside incubators. Sound emitted inside the hood was also distorted, i.e. it had different features from the same source in a free field. The insulating panel prevented amplification and distortion due to the hood and reduced the SPL of alarms. Only background noise did not decrease with the panel. Sound absorbing panel reduced baby's crying, porthole noise and alarm noise SPL to 82-85, 70-71 and 50-51 dB, respectively.

CONCLUSIONS

Incubators are reverberating environments, which amplify the baby's cry and other noises produced inside the hood. The frequency components of noises are altered by the hood. The sound absorbing panel reduced this phenomenon.

Newborn hearing screening by transient evoked otoacoustic emissions: analysis of response as a function of risk factors

Hearing loss can be considered as the most common birth defect. Early detection of hearing loss by screening at, or shortly after, birth and appropriate intervention are critical to speech, language and cognitive development. In the present study, the characteristics of Transient Evoked Otoacoustic Emissions have been evaluated as a function of known pre- and perinatal risk factors for hearing loss. All newborns were screened for hearing loss using a physiologic test of hearing function, the Transient Evoked Otoacoustic Emissions. A total of 532 consecutive newborn infants received binaural Transient Evoked Otoacoustic Emission testing (262 males, 270 females; mean gestational age 39.2 +/- 2.1 weeks, range 26-43; birth weight: 3,240 +/- 550 g, range 910-4,780). The population examined comprised 448 control infants and 84 high-risk for hearing loss infants (Joint Committee on Infant Hearing 1994 criteria). All Transient Evoked Otoacoustic Emission recordings were performed at comparable postconceptional ages. Audiological screening by Transient Evoked Otoacoustic Emission recording showed an overall 100% sensitivity, 99.02% specificity, with negative and positive predictive values of 100% and 62.5%, respectively. As compared to controls, high-risk infants showed: 1. increased rates of Fail-1 (Transient Evoked Otoacoustic Emissions absent at first examination, 21.4% vs 9.8%, p = 0.004), Fail-2 (Transient Evoked Otoacoustic Emissions absent on retesting: 8.64% vs 1.37%, p = 0.0014), false positives (Transient Evoked Otoacoustic Emissions absent/V wave present: 3.7% vs 0.46%, p = 0.029) and true positives (Transient Evoked Otoacoustic Emissions absent, V wave absent: 2.47% or 24.5 per 1,000 live births vs 0.22% or 2.2 per 1,000 live births, p = 0.013); 2. significantly reduced Transient Evoked Otoacoustic Emission intensity in the 0.7-1 kHz (right side) and 1-2 kHz (left side) frequency ranges. Multivariate logistic regression analysis showed a significant positive correlation between congenital hearing loss and the following risk factors: assisted ventilation lasting > 10 days (Odds ratio 14.8; 95% confidence interval, 4.5-48.8, p < 0.000001), severe birth asphyxia (Odds ratio 5.8; 95% confidence interval; 2.1-16.1; p = 0.0006) and administration of ototoxic drugs (Odds ratio 4.5; 95% confidence interval; 1.4-13.9; p = 0.009). Results of this study confirm the feasibility and accuracy of universal neonatal hearing screening based on recording Transient Evoked Otoacoustic Emissions. These data stress the importance of the risk factors for hearing loss, including prolonged assisted ventilation, ototoxic drugs, and severe birth asphyxia.

Alone no more: pain in premature children

It is only recently that newborns have been recognised to feel pain. To avoid the drawbacks of common analgesics, alternative analgesic methods (e.g. sucking and/or oral sugar) have been proposed. We showed that these methods are of little effect without the relaxing, distracting, comforting presence of a person at the cribside who talks to and massages the baby. This is a further demonstration that newborns, including premature babies, look for a reassuring presence when experiencing pain. This is surprising as premature babies are relatively unreactive, often completely isolated in an incubator and considered incapable of social behavior. To the attentive observer, however, they reveal an unsuspected emotional world. Not only do they feel pain, but they are also capable of suffering, distress, anxiety and fear. This needs to be considered in neonatal analgesic treatment, even for extremely premature children. It is mandatory for caregivers to be a reassuring presence during painful procedures: premature babies are exacting patients. They not only feel pain, they even suffer; they request not only drugs, but a human presence nearby.

Identification of activin A and follistatin in human milk

Activin A is a dimeric protein member of the transforming growth factor-beta (TGF-beta) family: it is synthesized by a variety of organs and follistatin is an activin-binding protein. A sensitive and specific assays for bioactive dimeric activin A and follistatin have recently allowed to measure these proteins in blood and other biological fluids, giving a new insights into their possible physiological role. Since human breast is able to produce activin A, the aim of the present study was to evaluate whether it and follistatin are measurable in breast milk of women during lactation. Concentrations of activin A and follistatin were measured in milk samples collected at 3, 5 and 30 days after delivery by using specific and sensitive two-site ELISAs. For the first time the presence of immunoreactive activin A and follistatin in human milk has been shown; no significant different concentration between the third and the fifth day after delivery was found. Furthermore, no difference of activin A and follistatin concentration between the whole and the skim milk or between spontaneous delivery and cesarean section was found. Milk activin A and follistatin concentrations after 1 month of lactation were significantly decreased (P < 0.01). Activin A and follistatin are present in human milk in high concentrations in the first week of lactation, while decrease after a month suggesting a possible role as growth factors in human milk.

Small thymus at birth: a predictive radiographic sign of bronchopulmonary dysplasia

OBJECTIVE

Emerging evidence indicates a relationship between bronchopulmonary dysplasia (BPD) and chorioamnionitis. Recent data provide evidence of an acute thymic involution in very low birth weight (VLBW) preterm infants and fetuses with histologic chorioamnionitis. We tested the hypothesis that a small thymus detected at birth on the routine chest radiograph is a predictor of BPD in VLBW infants.

METHODS

A prospective study was conducted on 400 VLBW preterm infants who survived >4 weeks (mean gestational age: 27.5 weeks [range: 24-30]; mean birth weight: 1010 g [range: 450-1450]). Thymic size was measured on routine chest radiographs taken in the first 6 hours after birth and expressed as the ratio between the transverse diameter of the cardiothymic image at the level of the carina and that of the thorax (CT/T). The accuracy of CT/T for identifying infants with BPD was tested using receiver operating characteristic curve analyses and multivariate logistic regression.

RESULTS

Fifty-one VLBW infants (12.7%) subsequently developed BPD. A small thymus (CT/T <0.28) was observed in 94.1% of the infants with BPD versus 2.9% of the infants without BPD. A small thymus at birth identified infants with BPD with 94.1% sensitivity and 98.3% specificity (odds ratio: 17.8; 95% confidence interval: 5.7-55.4).

CONCLUSIONS

A small thymus at birth on the standard chest radiograph can accurately identify VLBW infants who subsequently develop BPD.

Molecular cloning, characterisation and expression of a manganese superoxide dismutase gene from peach (Prunus persica [L.] Batsch)

Two cDNA clones encoding mitochondrial manganese superoxide dismutases (MnSODs) from peach ( Prunus persica [L.] Batsch) were identified, which show homologies to several plant MnSODs. The amino acid sequence predicted from one full-length clone ( MnSOD1) showed the highest homology to an MnSOD from Nicotiana plumbaginifolia (94%) and included a 24-amino acid transit peptide typical of those used to target proteins to the mitochondria. A second, partial clone ( MnSOD2) showed divergence from MnSOD1 in the 3' untranslated region. It could therefore derive from a second gene or from an allele of MnSOD1. Southern hybridisation analysis suggests the existence of two MnSOD genes in peach. SOD isoenzyme profiles, MnSOD1 expression and protein levels were studied in aerial vegetative tissues derived from plants of different ages and in adult plants during the seasonal cycle. Zymograms revealed at least two isoforms of MnSODs in pre-shooting vegetative buds and in developing fruits. Levels of MnSODs were lower in leaves derived from apical shoots of adult plants than in leaves derived from seedlings, basal shoots or in vitro propagated juvenile plants, which are considered as juvenile-like structures. The MnSOD1 transcript and protein followed the same pattern. The results suggest that the steady-state levels of MnSOD1 mRNA in leaves vary with both the ontogenetic stage and the growth rate of the tissues examined.

Effect of multisensory stimulation on analgesia in term neonates: a randomized controlled trial

Many attempts have been made to obtain safe and effective analgesia in newborns. Oral glucose-water has been found to have analgesic properties in neonates. We investigated whether other sensory stimulation added to oral glucose provided more effective analgesia than oral glucose alone. In a randomized prospective double-blind trial, we studied 120 term newborns during heel prick. The babies were divided randomly into six groups of 20, and each group was treated with a different procedure during heel prick: A) control; B) 1 mL 33% oral glucose given 2 min before the heel prick; C) sucking; D) 1 mL 33% oral glucose plus sucking; E) multisensory stimulation including 1 mL 33% oral glucose (sensorial saturation); F) multisensory stimulation without oral glucose. Sensorial saturation consisted in massage, voice, eye contact, and perfume smelling during heel prick. Each heel prick was filmed and assigned a point score according to the Douleur Aiguë du Nouveau-né (DAN) neonatal acute pain scale. Camera recording began 30 s before the heel prick, so it was impossible for the scorers to distinguish procedure A (control) from B (glucose given 2 min before), C (sucking water) from D (sucking glucose), and E (multisensory stimulation and glucose) from F (multisensory stimulation and water) from the video. Procedure E (multisensory stimulation and glucose) was found to be the most effective procedure, and the analgesia was even more effective than that produced by procedure D (sucking glucose). We conclude that sensorial saturation is an effective analgesic technique that potentiates the analgesic effect of oral sugar. It can be used for minor painful procedures on newborns.

Pathogenic mechanism, prophylaxis, and therapy of symptomatic acidosis induced by acetazolamide

BACKGROUND

Acetazolamide, a noncompetitive carbonic anhydrase inhibitor, can produce symptomatic acidosis and bone marrow suppression by a mechanism that is still unknown. This presentation occurs in the elderly, patients with renal or liver failure, people with diabetes, and newborns. The objective of this study was to understand the pathogenic mechanism of these adverse effects and to propose a possible prophylaxis and therapy.

METHODS

Four human clinical cases were studied, and one animal experiment was performed. Four preterm newborns with posthemorrhagic ventricular dilation developed severe metabolic acidosis after treatment with acetazolamide. The acidosis suddenly disappeared after a packed red blood cell transfusion. Metabolic studies were performed in one patient and in newborn guinea pigs treated with 200 mg/kg acetazolamide.

RESULTS

Acetazolamide can produce severe lactic acidosis with an increased lactate-to-pyruvate ratio, ketosis with a low beta-hydroxybutyrate-to-acetoacetate ratio, and a urinary organic acid profile typical of pyruvate carboxylase deficiency. The acquired enzymatic injury resulting from the inhibition of mitochondrial carbonic anhydrase V that provides bicarbonate to pyruvate carboxylase can produce tricarboxylic acid cycle damage. We demonstrate that the dramatic disappearance of metabolic acidosis and normalizing metabolism after blood transfusion were due to the citrate contained in the packed red blood cell bag. This hypothesis was confirmed by animal experimentation. We argue that the metabolic disorder and bone marrow suppression may be related.

CONCLUSION

We demonstrate how acetazolamide can lead to symptomatic metabolic acidosis and probably to bone marrow suppression. We suggest citrate as a possible prophylaxis and treatment for these adverse reactions.

Predictive value of skin color for illness severity in the high-risk newborn

The relationship between skin color and illness severity in the newborn remains untested. We have evaluated the predictive value of skin color readings for illness severity in a population of high-risk newborn infants. A prospective study was conducted on 107 white newborns in the intensive care unit, which were categorized as either high or low severity of illness, defined by the presence of severe neonatal morbidity. Illness severity was also determined using a Score for Neonatal Acute Physiology (SNAP). Color readings were obtained at 10 different body sites using a portable tristimulus colorimeter during the first 24 h, and color was expressed using the standard CIE L*a*b* system. Skin CIE b* values were significantly lower in the high severity group (p < 0.0001), and a significant inverse correlation with SNAP was observed (r(s) range, -0.37 to -0.71, p < 0.0001). In particular a low b* value for the abdomen was found to be a significant predictor of illness severity (92.6% sensitivity; 96.6% specificity; 96% positive predictive value; 93.7% negative predictive value; adjusted odds ratio, 14.7; 95% confidence interval, 6.4 to 33.8). Our findings indicate that skin color reflects clinical severity in the newborn and that skin colorimetry can accurately identify higher risk infants.

Is the "small world" effect relevant to evolution?

Mutations and selection are the driving forces of biological evolution. We model here the simplest case: an evolving population of asexual organisms. We consider two kinds of mutations: point mutations, corresponding to local displacements in the genotypic space, and all the other genotypic rearrangements, equivalent to long-range jumps. We show that a small-world effect is present in evolution: even a small fraction of quenched long-range jumps makes the results indistinguishable from those obtained by assuming all mutations equiprobable. We apply this result to the evolution of a population on a smooth fitness landscape, showing that the equilibrium distribution is a Boltzmann one, in which the fitness plays the role of an energy, and mutations that of a temperature.

Small world effects in evolution

For asexual organisms point mutations correspond to local displacements in the genotypic space, while other genotypic rearrangements represent long-range jumps. We investigate the spreading properties of an initially homogeneous population in a flat fitness landscape, and the equilibrium properties on a smooth fitness landscape. We show that a small-world effect is present: even a small fraction of quenched long-range jumps makes the results indistinguishable from those obtained by assuming all mutations equiprobable. Moreover, we find that the equilibrium distribution is a Boltzmann one, in which the fitness plays the role of an energy, and mutations that of a temperature.

Sensorial saturation: an effective analgesic tool for heel-prick in preterm infants: a prospective randomized trial

Pain is traumatic for preterm infants and can damage their CNS. We wanted to assess whether multisensorial stimulation can be analgesic and whether this effect is only due to oral glucose or sucking. We performed a randomized prospective study, using a validated acute pain rating scale to assess pain during heel-prick combined with five different procedures: (A) control, (B) 10% oral glucose plus sucking, (C) sensorial saturation (SS), (D) oral water, and (E) 10% oral glucose. SS is a multisensorial stimulation consisting of delicate tactile, vestibular, gustative, olfactory, auditory and visual stimuli. Controls did not receive any analgesia. We studied 85 heel-pricks (5 per baby) performed for routine blood samples in 17 preterm infants (28-35 weeks of gestational age). We applied in random order in each patient the five procedures described above and scored pain. SS and sucking plus oral glucose have the greater analgesic effect with respect to no intervention (p < 0.001). The effect of SS is statistically better than that of glucose plus sucking (p < 0.01). SS promotes interaction between nurse and infant and is a simple effective form of analgesia for the NICU.