Neonatal morbidity in singleton late preterm infants compared with full-term infants.

AIM: The aim of this study was to test the hypothesis that singleton late preterm infants (34 0/7 to 36 6/7 weeks of gestation) compared with full-term infants have a higher incidence of short-term morbidity and stay longer in hospital. METHODS: In this retrospective, multicentre study, electronic data of children born at five hospitals in Switzerland were recorded. Short-term outcome of late preterm infants was compared with a control group of full-term infants (39 0/7 to 40 6/7 weeks of gestation). Multiple gestations, pregnancies complicated by foetal malformations, maternal consumption of illicit drugs and infants with incomplete documentation were excluded. The results were corrected for gender imbalance. RESULTS: Data from 530 late preterm and 1686 full-term infants were analysed. Compared with full-term infants, late preterm infants had a significant higher morbidity: respiratory distress (34.7% vs. 4.6%), hyperbilirubinaemia (47.7% vs. 3.4%), hypoglycaemia (14.3% vs. 0.6%), hypothermia (2.5% vs. 0.6%) and duration of hospitalization (mean, 9.9 days vs. 5.2 days). The risk to develop at least one complication was 7.6 (95% CI: 6.2-9.6) times higher among late preterm infants (70.8%) than among full-term infants (9.3%). CONCLUSION: Singleton late preterm infants show considerably higher rate of medical complications and prolonged hospital stay compared with matched full-term infants and therefore need more medical and financial resources.

Spider, bee, and bird communities in cities are shaped by environmental control and high stochasticity.

Spatially organized distribution patterns of species and communities are shaped by both autogenic processes (neutral mechanism theory) and exogenous processes (niche theory). In the latter, environmental variables that are themselves spatially organized induce spatial structure in the response variables. The relative importance of these processes has not yet been investigated in urban habitats. We compared the variance explained by purely spatial, spatially structured environmental, and purely environmental components for the community composition of spiders (Araneae), bees (Apidae), and birds (Aves) at 96 locations in three Swiss cities. Environmental variables (topography, climate, land cover, urban green management) were measured on four different radii around sampling points (< 10 m, 50 m, 250 m, 1000 m), while Moran's eigenvector maps (MEMs) acted as spatial variables. All three taxonomic groups showed weak spatial structure. Spider communities reacted to very fine-scaled environmental changes of lawn and meadow management and climate. Bird community composition was determined by woody plants as well as solar radiation at all radii, the scale of the influence varying among species. Bee communities were weakly explained by isolated variables only. Our results suggest that the anthropogenic structuring of urban areas has disrupted the spatial organization of environmental variables and inhibited the development of biotic spatial processes. The near absence of spatial structure may therefore be a feature typical of urban species assemblages, resulting in urban community composition mainly influenced by local environmental variables. Urban environments represent a close-knit mosaic of habitats that are regularly disturbed. Species communities in urban areas are far from equilibrium. Our analysis also suggests that urban communities need to be considered as being in constant change to adapt to disturbances and changes imposed by human activities.

Intrauterine subdural hemorrhage in a preterm neonate possibly associated with maternal low-molecular weight heparin treatment.

We report intrauterine subdural hemorrhage in a preterm infant delivered by cesarean section at 32 weeks following vaginal bleeding of a mother treated with low-molecular weight heparin (LMWH) for deep vein thrombosis. The subdural hematomas were partially calcified, proving antenatal occurrence. Maternal trauma during pregnancy, intrauterine infection, cerebral vascular malformation and congenital coagulopathy as known etiologies of subdural hemorrhage could be ruled out. Intrauterine subdural hemorrhage may be an exceptional complication of maternal LMWH treatment.

Eleven polymorphic microsatellite markers for Oedaleus decorus (Orthoptera, Acrididae), an endangered grasshopper in Central Europe.

We isolated and characterized 11 microsatellite loci in the grasshopper Oedaleus decorus (Orthoptera: Acrididae), an endangered species in Central Europe. Polymorphism was studied from two populations, one out of two populations known from Switzerland (n = 20 individuals) and one site from south of France (n = 20). The number of alleles and the expected heterozygosity ranged from five to 12 and from 0.559 to 0.898, respectively, in the Swiss population, and from 14 to 23 and from 0.895 to 0.974, respectively, in the French population. These microsatellite markers are suitable for further conservation genetic studies of O. decorus.

Assessment of jaundice in preterm neonates: comparison between clinical assessment, two transcutaneous bilirubinometers and serum bilirubin values.

AIM: 1) To compare the clinical assessment of craniocaudal progression of jaundice and two transcutaneous bilirubinometers with serum bilirubin values in preterm neonates; 2) to identify factors affecting the difference between non-invasive bilirubin estimation and serum bilirubin. METHODS: Serum bilirubin was clinically estimated in healthy preterm newborn infants (34 to 36.9 gestational weeks) independently by a primary investigator and by nurses, and subsequently compared with separate measures of two transcutaneous bilirubinometers. RESULTS: A total of 107 measurements were performed on 69 infants. Minolta JM-102 showed the best performance, with ROC area under the curve of 0.96, followed by BiliCheck over the sternum (0.89) and over the forehead (0.88), clinical assessment by nurses (0.73) and by a physician (0.70). Serum bilirubin >190 micromol/l can be detected with 95% sensitivity with Minolta JM-102 > or =19 units, with BiliCheck > or =145 micromol/l over the sternum and > or =165 micromol/l over the forehead and with jaundice progression to the trunk or further (Kramer zone > or =2). Gestational age affects all non-invasive methods in the estimation of serum bilirubin, whereas skin colour affects both BiliCheck and clinical assessment. Ambient light affects only clinical assessment. CONCLUSION: Minolta JM-102 showed the best performance, closely followed by BiliCheck, with clinical assessment performing far worse than either transcutaneous method. None of the three methods are recommended as complete substitutes for serum bilirubin values in jaundiced preterm infants.

Agreement between capillary and arterial lactate in the newborn.

UNLABELLED: Arterial blood lactate is a reliable indicator of tissue oxygen debt and is of value in expressing the degree and prognosis of circulatory failure as a result of various diseases. Therefore, the practical issue of whether capillary lactate measurements might be of equal value was investigated in newborns. In total, 193 simultaneous measurements of capillary and arterial blood lactate concentrations were performed in 25 newborn babies with an indwelling umbilical arterial catheter. A strong linear correlation was found between capillary and arterial lactate concentration (Lcap = 1.02 Lart + 0.04; r = 0.98; p < 0.001). The mean difference was -0.08 mmol/l and the limits of agreement (+/- 2 SD) were +/- 0.69 mmol/l (-0.77 to 0.61 mmol/l). CONCLUSION: Our data show that capillary blood lactate measurements in newborn babies yield lactate concentrations equivalent to arterial measurements over a large concentration range.

Effect of acoustic clutter on prey detection by bats.

Bats that capture animal prey from substrates often emit characteristic echolocation calls that are short-duration, frequency-modulated (FM) and broadband. Such calls seem to be suited to locating prey in uncluttered habitats, including flying prey, but may be less effective for finding prey among cluttered backgrounds because echoes reflecting from the substrate mask the acoustic signature of prey. Perhaps these call designs serve primarily for spatial orientation. Furthermore, it has been unclear whether the acoustic image conveyed by FM echoes enables fine texture discrimination, or whether gleaning bats that forage in echo-cluttering environments must locate prey by using other cues, such as prey-generated sounds. Here we show that two species of insectivorous gleaning bats perform badly when compelled to detect silent and immobile prey in clutter, but are very efficient at capturing noisy prey items among highly cluttered backgrounds, and both dead or live prey in uncluttered habitats. These findings suggest that the short, broadband FM echolocation calls associated with gleaning bats are not adapted to detecting prey in clutter.

Closure of the ductus arteriosus and development of pulmonary branch stenosis in babies of less than 32 weeks gestation.

AIMS: To define how often transient pulmonary branch stenosis (PBS) develops after closure of a patent ductus arteriosus (PDA) in babies born at less than 32 weeks gestation; to describe the natural history of PBS and the relation between PBS and a cardiac murmur. METHODS: Fifty three preterm infants born at a gestational age less than 32 weeks and who had PDA diagnosed on echocardiography were recruited. An echocardiogram was performed on alternate days until the ductus arteriosus closed. If PBS was diagnosed, the baby was followed up until PBS resolved. RESULTS: In 59%, PBS developed in one or both branches after closure of the PDA. In 21%, both pulmonary branches were affected. In 79%, the left pulmonary artery alone was involved but the right side was never affected alone. PBS had resolved in 74% by the time the infants reached 40 weeks, in 95% at a corrected age of 6 weeks, and in 100% at a corrected age of 3 months. There is a better correlation between a cardiac murmur and PBS than between a murmur and PDA. CONCLUSIONS: PBS in preterm infants is usually not present at birth but develops after closure of a PDA. PBS resolves by a corrected age of 3 months. The presence of a murmur after closure of a PDA is usually related to PBS and not to reopening of the ductus arteriosus.

The energetic grooming costs imposed by a parasitic mite (Spinturnix myoti) upon its bat host (Myotis myotis).

Parasites often exert severe negative effects upon their host's fitness. Natural selection has therefore prompted the evolution of anti-parasite mechanisms such as grooming. Grooming is efficient at reducing parasitic loads in both birds and mammals, but the energetic costs it entails have not been properly quantified. We measured both the energetic metabolism and behaviour of greater mouse-eared bats submitted to three different parasite loads (no, 20 and 40 mites) during whole daily cycles. Mites greatly affected their time and energy budgets. They caused increased grooming activity, reduced the overall time devoted to resting and provoked a dramatic shortening of resting bout duration. Correspondingly, the bats' overall metabolism (oxygen consumption) increased drastically with parasite intensity and, during the course of experiments, the bats lost more weight when infested with 40 rather than 20 or no parasites. The short-term energetic constraints induced by anti-parasite grooming are probably associated with long-term detrimental effects such as a decrease in survival and overall reproductive value.

Is the Gibraltar strait a barrier to gene flow for the bat Myotis myotis (Chiroptera: Vespertilionidae)?

Because of their role in limiting gene flow, geographical barriers like mountains or seas often coincide with intraspecific genetic discontinuities. Although the Strait of Gibraltar represents such a potential barrier for both plants and animals, few studies have been conducted on its impact on gene flow. Here we test this effect on a bat species (Myotis myotis) which is apparently distributed on both sides of the strait. Six colonies of 20 Myotis myotis each were sampled in southern Spain and northern Morocco along a linear transect of 1350 km. Results based on six nuclear microsatellite loci reveal no significant population structure within regions, but a complete isolation between bats sampled on each side of the strait. Variability at 600 bp of a mitochondrial gene (cytochrome b) confirms the existence of two genetically distinct and perfectly segregating clades, which diverged several million years ago. Despite the narrowness of the Gibraltar Strait (14 km), these molecular data suggest that neither males, nor females from either region have ever reproduced on the opposite side of the strait. Comparisons of molecular divergence with bats from a closely related species (M. blythii) suggest that the North African clade is possibly a distinct taxon warranting full species rank. We provisionally refer to it as Myotis cf punicus Felten 1977, but a definitive systematic understanding of the whole Mouse-eared bat species complex awaits further genetic sampling, especially in the Eastern Mediterranean areas.

Noctuid moths show neural and behavioural responses to sounds made by some bat-marking rings.

Coloured rings are often used for marking bats so that specific individuals can be recognized. We noticed that the rings of mouse-eared bats, Myotis myotis and Myotis blythii, in a combination of one plastic-split and one metallic ring on the same forearm, emitted sounds that were largely ultrasonic each time the rings met in flight. We recorded the ring sounds and the echolocation calls produced by the bats, and played them back to neural preparations of lesser yellow underwing moths, Noctua comes, while making extracellular recordings from the moths' A1 auditory receptors. The peak energy of the ring sounds occurred much closer in frequency to the moth's best auditory frequency (the frequency at which the moth has the lowest auditory threshold) than the peak energy of the calls, for both bat species, and the ring sounds were detected at a threshold 5-6 dB peSPL lower than the calls. Moths performed evasive manoeuvres to playbacks of ring sounds more frequently than they did to control (tape noise) sequences. These neural and behavioural responses imply that certain bats should not be marked with two rings on one wing, as this may make the bat more apparent to tympanate insects, and may therefore reduce its foraging success. Copyright 1999 The Association for the Study of Animal Behaviour.

Natural history of innocent heart murmurs in newborn babies: controlled echocardiographic study.

AIM: To define the origin and the natural history of innocent heart murmurs in newborn infants. METHODS: Fifty healthy babies born at term with the clinical diagnosis of an innocent heart murmur and 50 controls without a murmur were studied. Each baby had a complete two dimensional and pulsed Doppler echocardiogram and those with any abnormality were followed up at 6 weeks, 3 months, and 6 months until the murmur had disappeared or the heart was totally normal. Babies with congenital heart disease were excluded from the study. RESULTS: Pulmonary branch stenosis (PBS) was found in 25 (50%) of the study group and in six (12%) controls; patent ductus arteriosus (PDA) in 30 (60%) subjects and in six (12%) controls; and a patent foramen ovale (PFO) in 50 (100%) subjects and in 41 (82%) controls. At 6 weeks the murmur had disappeared in 64% of babies. PBS was still present in eight of 22 (36%) babies at 6 weeks, in 12% at 3 months, but in none at 6 months. At 6 weeks, seven of the eight with PBS still had a murmur compared with two of 14 (14%) babies in which the PBS had resolved (P < 0.005). At 6 weeks the PDA had closed in all patients but the foramen ovale was still patent in 29 of 44 (66%) subjects and nine of 33 (27%) controls. The closure of the PFO was not influenced by its size at birth. CONCLUSIONS: An innocent heart murmur in a baby born at term is often related to PBS, particularly if the murmur is still present after 24 hours of age, when most PDA have closed. At 6 weeks the murmur had disappeared and the PBS had resolved in 64% of the babies. PBS had resolved in all babies at 6 months.

Randomized controlled trial of Ringer solution versus serum for partial exchange transfusion in neonatal polycythaemia.

UNLABELLED: We tested whether crystalliod solutions could be used instead of colloid solutions for partial exchange transfusions (PET) in polycythaemic neonates because crystalloid solutions are cheap, carry no risk of anaphylactic reactions and can be sterilized. We randomly assigned 20 term neonates with venous haematocrit (Hct) > 0.65 l/l to PET with either a serum preparation (BISEKO) or Ringer solution. Plasma volume (PV) was measured with Evans blue dilution. Blood volume (BV) and red cell mass were calculated from PV and venous Hct. Before PET both serum and Ringer groups had the same Hct (0.69 (0.66-0.76) vs 0.69 (0.66-0.71) l/l; median (range)) and BV (108 (81-116) versus 96 (68-121) ml/kg. During PET an equivalent amount of blood was withdrawn stepwise (19 (14-26) versus 17 (13-25) ml/kg and replaced by either serum or Ringer solution. More of the Ringer solution (median 77%) than of the serum (median 36%) given left the intravascular space within 4 h after PET (P = 0.016); but there was no significant difference in Hct after Ringer-PET compared to serum-PET (median 0.58 vs 0.56 l/l). No infant required repeat PET. Ringer-PET reduced BV from high to normal values (from median 96 to 83 ml/kg; P = 0.005), whereas after serum-PET BV remained high (from median 108 to 98 ml/kg; not significant). CONCLUSION: PET with Ringer solution resulted in a haemodilution comparable to PET with serum and a correction of hypervolaemia.

Low-frequency echolocation enables the bat Tadarida teniotis to feed on tympanate insects.

The European free-tailed bat, Tadarida teniotis, forages in uncluttered airspace by using intense narrow-band echolocation calls with low frequency (11-12 kHz), and feeds on relatively large flying insects, mainly (90% by volume) of the tympanate orders Lepidoptera and Neuroptera. The use of low-frequency echolocation calls without strong harmonics appears to be a specialization for long-range detection of large, tympanate insects, which are less well represented in the diet of most other aerial-hawking bats. The results provide evidence in support of the allotonic frequency hypothesis, i.e. that use of echolocation calls with frequencies above or below the best hearing of tympanate insects is an adaptation to increase the availability of these insects.

[Triplets and quadruplets in Switzerland, 1985-1988]. / Triplés et quadruplés en Suisse, 1985-1988.

To determine the incidence of multiple births and associated morbidity and mortality, we collected in a retrospective study all the multiple births (twins excluded) in Switzerland from 1985 to 1988. In all we followed 77 sets of triplets and 9 sets of quadruplets, representing an annual incidence of 1/3968 births for the triplets and 1/33,947 births for the quadruplets. The incidence of induced pregnancies increased in the period 1985 to 1988. The principal complications were premature contractions and preeclampsia. Only 56% of the children were born in a hospital with a neonatal intensive care unit. The mean gestational age was 33 0/7 weeks (ranging from 25 0/7 to 38 5/7) for the triplets, and 30 5/7 weeks (ranging from 27 5/7 to 36 3/7) for the quadruplets. The mean birthweight was 1787 g (ranging from 560 to 3000 g) for the triplets and 1189 g (ranging from 590 to 1980 g) for the quadruplets. RDS was found to be the principal neonatal pathology (65.5% of triplets and 85.2% of quadruplets) with 18.8% of triplets and 61.8% of quadruplets requiring ventilation. The mortality rate in our study was 8.9% for triplets and 14.7% for quadruplets.