Effects of faba beans with different concentrations of vicine and convicine on egg production, egg quality and red blood cells in laying hens

The faba bean (Vicia faba L.) is a potential source of proteins for poultry, mainly for laying hens whose protein requirements are lower than those of other birds such as growing broilers and turkeys. However, this feedstuff contains anti-nutritional factors, that is, vicine (V) and convicine (C) that are already known to reduce laying hen performance. The aim of the experiment reported here was to evaluate the effects of a wide range of dietary V and C concentrations in laying hens. Two trials were performed with laying hens fed diets including 20% or 25% of faba bean genotypes highly contrasting in V+C content. In Trial 1, faba beans from two tannin-containing cultivars, but with high or low V+C content were dehulled in order to eliminate the tannin effect. In addition to the contrasting levels of V+C in the two cultivars, two intermediate levels of V+C were obtained by mixing the two cultivars (70/30 and 30/70). In Trial 2, two isogenic zero-tannin faba bean genotypes with high or low V+C content were used. In both trials, a classical corn-soybean diet was also offered to control hens. Each experimental diet was given to 48 laying hens for 140 (Trial 1) or 89 (Trial 2) days. Laying performance and egg quality were measured. The redox sensitivity of red blood cells (RBCs) was assessed by measuring hemolysis and reduced glutathione (GSH) concentration in these cells. Egg weight was significantly reduced by the diets containing the highest concentrations of V+C (P<0.0001) in Trial 1 and slightly reduced (P<0.10) in Trial 2, but only weak linear relationships between egg weight and dietary V+C concentration were established. No negative effect of V+C level was observed for egg quality parameters. In contrast, certain parameters (i.e. Haugh units, yolk color) were improved by feeding low V+C diets (P<0.05). Hemolysis of RBCs was higher in hens fed high V+C diets. A decrease in GSH concentration in RBCs of hens fed the highest levels of V+C was observed. Faba bean genotypes with low concentrations of V+C can therefore be used in laying hen diets up to 25% without any detrimental effects on performance levels or egg characteristics, without any risk of hemolysis of RBCs.

Genetic diversity in European Pisum germplasm collections

The distinctness of, and overlap between, pea genotypes held in several Pisum germplasm collections has been used to determine their relatedness and to test previous ideas about the genetic diversity of Pisum. Our characterisation of genetic diversity among 4,538 Pisum accessions held in 7 European Genebanks has identified sources of novel genetic variation, and both reinforces and refines previous interpretations of the overall structure of genetic diversity in Pisum. Molecular marker analysis was based upon the presence/absence of polymorphism of retrotransposon insertions scored by a high-throughput microarray and SSAP approaches. We conclude that the diversity of Pisum constitutes a broad continuum, with graded differentiation into sub-populations which display various degrees of distinctness. The most distinct genetic groups correspond to the named taxa while the cultivars and landraces of Pisum sativum can be divided into two broad types, one of which is strongly enriched for modern cultivars. The addition of germplasm sets from six European Genebanks, chosen to represent high diversity, to a single collection previously studied with these markers resulted in modest additions to the overall diversity observed, suggesting that the great majority of the total genetic diversity collected for the Pisum genus has now been described. Two interesting sources of novel genetic variation have been identified. Finally, we have proposed reference sets of core accessions with a range of sample sizes to represent Pisum diversity for the future study and exploitation by researchers and breeders.

CAPs markers to assist selection for low vicine and convicine contents in faba bean (Vicia faba L.)

The antinutritional factors (ANFs) present in Vicia spp. seeds are a major constraint to the wider utilization of these crops as grain legumes. In the case of faba bean (Vicia faba L.), a breeding priority is the absence vicine and convicine (v-c); responsible for favism in humans and for the reduced animal performance or low egg production in laying hens. The discovery of a spontaneous mutant allele named vc-, which induces a 10-20 fold reduction of v-c contents, may facilitate the process. However, the high cost and difficulty of the chemical detection of v-c seriously restricts the advances in breeding-selection. To identify random amplified polymorphic DNA (RAPD) markers linked to this gene, we have analysed an F(2 )population derived from a cross between a line with high v-c content (Vf6) and the vc- genotype (line 1268). Quantification of v-c was done by spectrophotometry on the parents and the F(2 )population (n = 136). By using bulked segregant analysis (BSA), two RAPD markers linked in coupling and repulsion phase to the allele vc- were identified and further converted into sequence characterized amplified regions (SCARs). Amplification of SCARS was more consistent, although the initial polymorphism between pools was lost. To recover the polymorphisms several approaches were explored. Restriction digestion with HhaI (for SCAR SCH01(620)) and RsaI (for SCAR SCAB12(850)) revealed clear differences between the parental lines. The simultaneous use of the two cleavage amplified polymorphism (CAP) markers will allow the correct fingerprinting of faba bean plants and can be efficiently used in breeding selection to track the introgression of the vc- allele to develop cultivars with low v-c content and improved nutritional value.

Mapping of the nodulation loci sym9 and sym10 of pea ( Pisum sativum L.)

Several mutants defective in the nodulation process during rhizobial or endomycorrhizal endosymbiosis of pea have been identified previously. We have integrated the map positions of two such nodulation mutations, sym9 and sym10, into the molecular map of pea by applying molecular-marker techniques combined with bulked segregant analysis (BSA). Lines P2 and P54 were found to carry alleles of sym9, line P56 carried an allele of sym10. F2 populations were derived from crosses of P2, P54 and P56, to JI281 and JI15, two of the parental lines that have been used previously to generate a molecular map of pea. sym9 was located on linkage group IV by AFLP-BSA analysis and subsequently mapped by RFLP in both F2 populations, P2 x JI281 and P54 x JI281. RFLP-BSA analysis was applied to assign sym10 to linkage group I. The RFLP marker locus, chs2, co-segregates with sym10 in the F2 population of P56 x JI15.

Combinatorial variation in coding and promoter sequences of genes at the Tri locus in Pisum sativum accounts for variation in trypsin inhibitor activity in seeds

Cultivars of Pisum sativum that differ with respect to the quantitative expression of trypsin/chymotrypsin inhibitor proteins in seeds have been examined in terms of the structure of the corresponding genes. The patterns of divergence in the promoter and coding sequences are described, and the divergence among these exploited for the development of facile DNA-based assays to distinguish genotypes. Quantitative effects on gene expression may be attributed to the overall gene complement and to particular promoter/coding sequence combinations, as well as to the existence of distinct active-site variants that ultimately influence protein activity. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00438-002-0667-4.

Cerebral blood flow and neurological outcome in the preterm infant

Cerebral blood flow (CBF) studies have provided some insight into pathophysiological mechanisms of cerebral damage in newborn children; their value in predicting brain damage, however, remains elusive. The purpose of our study was to evaluate the role of CBF measurements in predicting developmental outcome in preterm neonates at 18 months. Preterm babies with a gestational age of less than 34 weeks and a birth weight of less than 1500 g (n = 71) were enrolled in the study. CBF was measured by the noninvasive intravenous 133Xe method on three different occasions. We classified our measurements into three groups: depending on the time when performed group 1: between 2 and 36 h (n = 52); group 2: between 36 and 108 h (n = 44); group 3: between 108 and 240 h (n = 41). At the age of 18 months neurodevelopment testing was performed according to the Bayley mental and motor scales. Surviving infants had a higher mean CBF over the three groups than non surviving children (15.2 +/- 3.5 ml/100 g brain tissue/min vs 13.0 +/- 2.1 ml/100 g brain tissue/min, P < 0.05). There was no correlation of CBF with mental or motor development in our study population in either of the three groups.

CONCLUSION

In preterm infants basal CBF is higher in surviving than in non surviving infants, but there is no correlation of resting CBF and later neurological outcome.

Sleep state changes associated with cerebral blood volume changes in healthy term newborn infants

In order to assess the possible effects of sleep states on cerebral haemodynamics in healthy term infants, we measured cerebral oxyhaemoglobin, deoxyhaemoglobin and total haemoglobin concentration using near infrared spectroscopy. Thirty-seven sleep state changes in seventeen infants (gestational age: 37 to 41 4/7 weeks), aged between two and eight days were continuously registrated during 1-3 h. Transcutaneous PaO2, PaCO2, arterial O2 saturation and heart rate were simultaneously recorded and sleep states were clinically defined. There was a close relationship between sleep state changes and changes in total cerebral haemoglobin concentration, which increased from active to quiet sleep and decreased from quiet to active sleep. Changes in total cerebral haemoglobin were due, in the most part, to changes in the cerebral oxyhaemoglobin concentration. In conclusion, sleep states influence the cerebral haemoglobin concentration. Studies on cerebral haemodynamics should take sleep state into account in term newborn infants.

Effect of nursing in the head elevated tilt position (15 degrees) on the incidence of bradycardic and hypoxemic episodes in preterm infants

OBJECTIVE

We investigated whether nursing in the head elevated tilt position (HETP), compared with the horizontal position, has any effect on the incidence of bradycardic and hypoxemic episodes in preterm infants.

METHODS

Twelve spontaneously breathing preterm infants with idiopathic recurrent apnea were studied in a randomized controlled crossover trial. Nine infants were treated with aminophylline. Each spent a total of 24 hours in the horizontal prone position and a total of 24 hours in HETP (prone, 15 degrees). The position was changed in random order every 6 hours. Thoracic impedance, heart rate, and arterial oxygen saturation were recorded continuously. The frequency of isolated hypoxemia (arterial saturation <80%), of isolated bradycardia (heart rate <90 beats per minute), and of mixed events was analyzed and compared without knowledge of the allocated position.

RESULTS

In total, there were significantly fewer bradycardic and/or hypoxemic episodes (28.2%) in HETP compared with the horizontal position (mean difference, 13.35 episodes/24 hours; 95% confidence interval [CI]: 5.9- 20.8). The decrease was largest for isolated hypoxemic episodes (48.5%; mean difference, 11.74 episodes/24 hours; 95% CI: 6.1-17.4). Isolated bradycardic episodes (mean difference, 2.27 episodes/24 hours; 95% CI: -0.78-5.31) and mixed events were not decreased significantly in HETP.

CONCLUSIONS

Nursing in a moderately tilted position (15 degrees) reduces hypoxemic events in preterm infants. This intervention is easy to apply, quickly reversible, and can be combined with drugs such as aminophylline.

Continuous noninvasive measurement of cerebral arterial and venous oxygen saturation at the bedside in mechanically ventilated neonates

OBJECTIVES

To test the practicablity of a new spectrophotometric method using pulse oximetric techniques in combination with special filters for the noninvasive determination of cerebral arterial and venous oxygen saturation and oxygen extraction in neonatal intensive care unit patients. The spectrophotometer used three different wavelengths at a sampling rate of 100 Hz.

DESIGN

Clinical evaluation of a new method and comparison with previously published data.

SETTING

Design and construction of the special spectrophotometer at the Biomedical Engineering Laboratory of the Swiss Federal Institute of Technology. Measurements in the neonatal intensive care unit of the University Hospital, Zurich, Switzerland.

PATIENTS

Convenience sample of 15 clinically stable newborn infants, who were mechanically ventilated and receiving supplemental oxygen. Median gestational age was 29 5/7 wks (range 26 3/ 7 to 36 0/7), median birth weight was 1555 g (720 to 2500), median postnatal age was 4 days (1 to 10).

INTERVENTIONS

The emitter and receiver were placed on the forehead near the sagittal sinus, between 2 and 2.8 cm apart, and the pulsating light attenuations (arterial and venous pulse waves) were recorded.

MEASUREMENTS AND MAIN RESULTS

Arterial and venous pulse waves were satisfactory in 10 of 15 infants. Mean cerebral arterial oxygen saturation was 89.9 +/- 5.4% (SD), mean cerebral venous oxygen saturation was 73.0 +/- 8.9%, and mean cerebral oxygen extraction was 16.9 +/- 11.7%. A linear regression analysis demonstrated a significant correlation between mean PCO2 and venous oxygen saturation (slope 1.0%/torr, p < .05) and between mean PCO2 and cerebral oxygen extraction (slope -1.3%/torr, p < .05).

CONCLUSION

This new method has the potential for monitoring continuously, noninvasively, and simultaneously cerebral arterial and venous oxygen saturation and oxygen extraction in mechanically ventilated preterm infants.

Loss of CO2 reactivity of cerebral blood flow is associated with severe brain damage in mechanically ventilated very low birth weight infants

BACKGROUND

Early detection of pathophysiological factors associated with permanent and severe brain damage in preterm infants requiring intensive care is a major issue in neonatal neurology. The aim of this study was to investigate if an abnormal CO2 reactivity of cerebral blood flow in high risk very low birth weight infants is associated with severe brain injury demonstrated at autopsy or by neurodevelopment examination at 18 months.

METHODS

The CO2 reactivity of cerebral blood flow (xenon-133) was measured in 18 mechanically ventilated, severely ill, very low birthweight infants (gestational age 26-32 weeks, birthweight: 630-1360 g) during the first 36 hours of life. Cerebral outcome was assessed on autopsy findings (n = 8) or at the age of 18 months using Bayley developmental scales (n = 10).

RESULTS

Eight infants with normal development at 18 months (within mean +/- 2.5 SD of reference group) and two infants with normal cerebral autopsy findings had a median CO2 reactivity of 24.4%/kPa CO2 (interquartile range 14.7-41.2). Two infants with abnormal development (> 2.5 SD below mean) and six infants with hypoxic-ischaemic encephalopathy at autopsy has a median CO2 reactivity of 3.4%/kPa CO2 (interquartile range 8.0-11.7).

CONCLUSION

In mechanically ventilated very low birthweight infants low CO2 reactivity of cerebral blood flow (below 10%/kPa CO2) during the first 36 hours of life was associated with poor neurodevelopmental outcome or hypoxic-ischaemic encephalopathy at autopsy. Loss of CO2 reactivity may play a role in the pathogenesis of hypoxic ischaemic encephalopathy. It is a candidate for predicting early severe brain damage in preterm infants requiring intensive care and for controlling the effect of early interventions.

Body proportionality in growth-retarded VLBW infants

The aim of this study was to investigate how intrauterine growth retardation affects body proportions in VLBW infants. The cohort consisted of 135 surviving and 80 deceased preterm infants weighing less than 1250 grams at birth. Gestational age varied between 24 and 36 weeks (mean age 29.7 and 27.5 weeks, respectively). Birth weight was more than 2 SD below the mean birth standard values in 32% of the surviving, and in 27% of the deceased infants. Reduction of weight, length and head circumference at birth was analysed using Z scores based on Swedish birth standards. Z scores of weight, length and head circumference were highly correlated in the surviving and the deceased infants (r = 0.78 to 0.94 and 0.65 to 0.97, respectively). Length was significantly more affected by growth retardation than weight. Weight and head circumference were proportionately reduced. Intrauterine growth retardation influences body proportions in VLBW infants differently than in larger preterm and term infants.

Diagnostic and prognostic value of cerebral 31P magnetic resonance spectroscopy in neonates with perinatal asphyxia

The impact of depressed neonatal cerebral oxidative phosphorylation for diagnosing the severity of perinatal asphyxia was estimated by correlating the concentrations of phosphocreatine (PCr) and ATP as determined by magnetic resonance spectroscopy with the degree of hypoxic-ischemic encephalopathy (HIE) in 23 asphyxiated term neonates. Ten healthy age-matched neonates served as controls. In patients, the mean concentrations +/- SD of PCr and ATP were 0.99 +/- 0.46 mmol/L (1.6 +/- 0.2 mmol/L) and 0.99 +/- 0.35 mmol/L (1.7 +/- 0.2 mmol/L), respectively (normal values in parentheses). [PCr] and [ATP] correlated significantly with the severity of HIE (r = 0.85 and 0.9, respectively, p < 0.001), indicating that the neonatal encephalopathy is the clinical manifestation of a marred brain energy metabolism. Neurodevelopmental outcome was evaluated in 21 children at 3, 9, and 18 mo. Seven infants had multiple impairments, five were moderately handicapped, five had only mild symptoms, and four were normal. There was a significant correlation between the cerebral concentrations of PCr or ATP at birth and outcome (r = 0.8, p < 0.001) and between the degree of neonatal neurologic depression and outcome (r = 0.7). More important, the outcome of neonates with moderate HIE could better be predicted with information from quantitative 31P magnetic resonance spectroscopy than from neurologic examinations. In general, the accuracy of outcome predictability could significantly be increased by adding results from 31P magnetic resonance spectroscopy to the neonatal neurologic score, but not vice versa. No correlation with outcome was found for other perinatal risk factors, including Apgar score.

[Prenatal and perinatal infections--problems for the practicing pediatrician: group B streptococci, varicella, toxoplasmosis]

A practical approach is reported for the care of the neonate born to a mother infected/colonized during pregnancy by group B streptococcus, varicella-zoster virus or Toxoplasma gondii. Starting from clinical situations, an attempt is made to work out evidence based recommendations using an overview of the current literature. GROUP B STREPTOCOCCI: Relevant factors for the treatment of infants born to colonized mothers are clinical symptoms, gestational age, additional risk factors (such as premature rupture of membranes or maternal fever) and intrapartum antibiotics. Postnatal antibiotic prophylaxis and laboratory screens failed the test of controlled trials. Transfer to a neonatology unit is recommended for symptomatic term and all preterm infants. Asymptomatic term infants should be carefully monitored during the first 48 hours for signs of respiratory, circulatory or thermoregulatory compromise. VARICELLA: In the case of maternal varicella near term, delaying delivery for one week will lower the risk of severe neonatal varicella. The postnatal administration of varicella-zoster-immunoglobulin to the neonate is supported by some (if limited) evidence from the literature in the case of maternal eruption between 7 days before and 2 days after delivery. In newborns of mothers with eruption appearing later immunoglobulin is often recommended, though no supporting clinical evidence is available. There are no data to justify the use of immunoglobulin after exposure during pregnancy in order to prevent pneumonia in the pregnant patient, but there are preliminary indications that its application could lower the risk of congenital varicella syndrome (2% between 13 and 20 weeks). The use of immunoglobulin in very low birth weight infants after nosocomial exposure is generally recommended but efficacy data are lacking. TOXOPLASMOSIS: The practical approach depends on clinical findings in the newborn and laboratory results during pregnancy and after birth. Examination of the newborn should include fundoscopy, cranial sonography and, in cases of documented infection, lumbar puncture. Serology from cord blood comprises assays for IgG, IgM and if possible IgA/IgE. If available, demonstration of the parasite by culture or PCR can be helpful. All infants with documented congenital toxoplasmosis should be treated for a minimum of 12 months. In the case of suspected toxoplasmosis the child should be treated as long as the suspicion persists. The prognosis after consequential therapy is less bleak than previously reported for untreated children even in seriously symptomatic patients.

Regional differences of cerebral blood flow in the preterm infant

The purpose of our study was to evaluate the regional distribution of the resting cerebral blood flow (CBF) pattern in preterm neonates. Sixty-eight preterm babies with a gestational age of less than 34 weeks and a birth weight of less than 1500 g were enrolled into the study. The CBF was measured by the noninvasive intravenous 133Xenon method at three different times. Depending on the age we classified our measurements into three groups. Group 1: measurement between 2-36 h (n = 46). Group 2: measurement between 36-108 h (n = 39). Group 3: measurement between 108-240 h (n = 41). In all three groups CBF was significantly lower in the occipital region than in the frontal and parietal regions (group 1: frontal region 12.8 +/- 3.5 ml/100 g/min, parietal region 12.8 +/- 3.9 ml/100 mg/min, and occipital region 11.6 +/- 3.18 ml/100 g/min; group 2: frontal region 15.4 +/- 4.2 ml/100 g/min, parietal region 15.3 +/- 4.1 ml/100 g/min, and occipital region 13.4 +/- 3.5 ml/100 g/min; group 3: frontal region 14.6 +/- 3.6 ml/100 g/min, parietal region 14.6 +/- 3.2 ml/100 g/min, and occipital region 12.8 +/- 2.7 ml/100 g/min.). CBF did not differ between the left and the right hemispheres in either of the three measured regions. No gradient was found in infants between 108 h and 240 h of age with periventricular leukomalacia and periventricular haemorrhage. CONCLUSION. In preterm neonates the antero-posterior gradient of CBF is already present. Periventricular leukomalacia as well as periventricular haemorrhage may affect the regional regulation of CBF.

Sucrose reduces pain reaction to heel lancing in preterm infants: a placebo-controlled, randomized and masked study

In term infants sucrose given by mouth has been reported to reduce duration of crying after a heel prick. This study was designed primarily to investigate the effect of sucrose administered orally immediately before heel lancing on the nociceptive reaction in preterm infants as assessed by change in heart rate and duration of crying. A secondary objective was to document changes in cerebral blood volume during acute pain. We used a randomized, masked, placebo-controlled, crossover trial in a neonatal intermediate care unit in a level 3 perinatal center. The patients studied were 16 preterm infants; birth weight, 900-1900 g; gestational wk, 27-34; corrected postmenstrual age at time of investigation, 33-36 wk. Each infant was assessed twice receiving 2 mL of sucrose 50% or 2 mL of distilled water in random order immediately before heel lance. Heart rate, thoracic movements, and transcutaneous blood gases were monitored continuously. Crying during the procedure was documented by a video-camera. A change in cerebral blood volume was assessed by near-infrared spectroscopy. We found the heart increased by a mean of 35 beats/min (bpm) after sucrose and 51 bpm after placebo (median difference 16 bpm, interquartile range 1-30 bpm, p = 0.005). Infants cried 67% of time after sucrose and 88% after placebo (median difference 10%, interquartile range 3-33%, p = 0.002). Cerebral blood volume decreased in 5 of 14 infants after sucrose and in 6 of 14 infants after placebo (difference not significant).

TE7, An Inefficient Symbiotic Mutant of Medicago truncatula Gaertn. cv Jemalong

A mutagenesis program using ethylmethane sulfonate on Medicago truncatula Gaertn cv Jemalong, an annual, autogamous and diploid lucerne, permitted the isolation of a mutant (TE7) unable to establish an effective nitrogen-fixing symbiosis, [Nod+Fix-], with Rhizobium meliloti wild-type strains. The mutant phenotype is characterized by an altered infection process that leads to the formation of two kinds of inefficient nodules on the same root system. A certain proportion of the nodules are small, round, and uninfected, with infection threads limited to the outer root cortical cells. Others develop to a normal elongated shape and are infected; bacterial release occurs but the bacteria do not differentiate into bacteroids. The ratio of invaded to uninvaded nodules depends on the bacterial strain used. Throughout the infection process, certain events correlated with the plant defense response against pathogens can be observed: (a) the presence of polyphenolic compounds associated with the walls of infected cells and also with some parts of infection threads in the root cortex; (b) appositions on infection thread walls during the early stage of infection and also within the central tissue of infected nodules; and (c) autophagy of the plant cells that contain released bacteria. Genetic data suggest that the phenotype of TE7 is under monogenic and recessive control; this gene has been designated Mtsym1.

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

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.

Cerebral blood flow in preterm infants affected by sex, mechanical ventilation, and intrauterine growth

Sex differences in cerebral blood flow (CBF) values have been demonstrated in adults but not in newborns. This study evaluated the influence of sex, intrauterine growth, and need of mechanical ventilation on resting cerebral blood flow in preterm neonates. Sixty-eight preterm infants with gestational ages of less than 34 weeks and birth weights of less than 1,500 gm were enrolled into the study. Cerebral blood flow was measured by the noninvasive intravenous xenon 133 method 3 times. Measurements were classified into 3 groups: group 1: measurement at 2-36 hours (n = 46); group 2: measurement at 36-108 hours (n = 39); and group 3: measurement at 108-240 hours (n = 41). In all 3 groups, the CBF in girls was significantly lower than in boys (group 1: 11.5 +/- 2.8 ml/100 gm/min vs 14.0 +/- 4.1 ml/100 gm/min; group 2: 13.4 +/- 2.9 ml/100 gm/min vs 16.3 +/- 4.3 ml/100 gm/min; group 3: 12.9 +/- 3.2 ml/100 gm/min vs 15.3 +/- 3.1 ml/100 gm/min). In group 1, the CBF in neonates requiring mechanical ventilation was significantly lower (P < .05) than in patients who were spontaneously breathing (11.5 +/- 3.7 ml/100 gm/min vs 14.2 +/- 3.1 ml/100 gm/min), and the CBF in neonates who were too small for gestational age was significantly higher (P < .005) than in children with appropriate intrauterine growth (16.1 +/- 4.1 ml/100 gm/min vs 11.5 +/- 2.6 ml/100 gm/min). It is concluded that in preterm neonates CBF is substantially affected by sex, intrauterine growth retardation, and the need of mechanical ventilation.

Artifactual pulse-oximetry estimation in neonates

Two sources of artifactual pulse-oximetry estimation were investigated in 20 neonates. Increased pressure on tissue due to inappropriate sensor fixation was mimicked with a blood pressure cuff. The error in arterial oxygen saturation (pSO2) exceeded 2 SD (> 3%) in 25% subjects at 50 mm Hg which in an ancillary experiment was produced by 11 of 26 nurses fixing the sensor. Venous congestion at 30 and 40 mm Hg permitted normal detection of pulse rate but induced errors in pSO2 over 2 SD in 15% and 30% of subjects, respectively. Pulse-oximeter values need to be scrutinised for these common errors.

The effect of epoetin beta (recombinant human erythropoietin) on the need for transfusion in very-low-birth-weight infants. European Multicentre Erythropoietin Study Group

BACKGROUND

Anemia of prematurity is characterized by low reticulocyte counts and inadequate erythropoietin response, for which many very-low-birth-weight infants receive multiple blood transfusions. We investigated whether early treatment of such infants with recombinant human erythropoietin would reduce their need for transfusions.

METHODS

We performed a controlled, blinded trial in 241 infants with very low birth weights at 12 centers in six European countries. When three days old, the infants were randomly assigned either to the epoetin group or to the control group. Those in the epoetin group received 250 IU of epoetin beta per kilogram of body weight subcutaneously three times a week from day 3 to day 42 (for a total of 17 doses); those in the control group did not receive this drug. Infants in both groups received oral iron (2 mg per day) from day 14 onward.

RESULTS

The control infants needed a mean of 1.25 transfusions each, as compared with 0.87 transfusion for epoetin-treated infants (P = 0.013). The median cumulative volume of blood transfused per kilogram per day was 0.41 ml in the control group (first quartile, 0 ml; third quartile, 0.8 ml) and 0.09 ml in the epoetin group (first quartile, 0 ml; third quartile, 0.8 ml) (P = 0.044). The rate of success, defined as an absence of need for transfusions and a hematocrit that never fell below 32 percent, was 4.1 percent in the control group and 27.5 percent in the epoetin group (P = 0.008). Epoetin was most beneficial in boys with birth weights of 1200 g or more and a base-line hematocrit of 48 percent or more. No toxic effects were observed in the epoetin group; as compared with the control group, the epoetin group had an increased incidence of septicemia (14 vs. 7 episodes, P not significant) and reduced weight gain (520 vs. 571 g, P = 0.02).

CONCLUSIONS

Infants with very low birth weights have less need of transfusions if given epoetin beta during the first six weeks of life (250 IU per kilogram three times a week). We recommend early epoetin treatment for all such infants, but further studies of nutrition and iron supplementation during treatment are needed.

Effect of aminophylline on cerebral haemodynamics and oxidative metabolism in premature infants

The effect of aminophylline on cerebral blood volume and oxidative metabolism in newborn infants was investigated with near infrared spectroscopy (NIRS). Thirteen mechanically ventilated premature infants who received aminophylline to facilitate weaning from the respirator were selected. Gestational age ranged between 26 and 34 weeks, postnatal age between 1 and 7 days and birth weight between 760 and 2300 g. A bolus of 6 mg aminophylline/kg body weight was infused within 2 min. NIRS was performed continuously across the head to monitor changes in cerebral blood volume and cytochrome c oxidase. Heart rate, transcutaneous carbon dioxide tension (tcpCO2) and arterial haemoglobin oxygen saturation (SO2) were recorded simultaneously. The infusion of aminophylline was associated with an increase in heart rate (median 12, interquartile range 5-20 beats per min, P = 0.0004) and a drop in tcpCO2 (median -0.4, interquartile range -0.1 to -0.5 kPa, P = 0.015). Oxygen saturation remained stable (+/- 3%). A decrease in cerebral blood volume was measured with NIRS in 9/13 patients (median -0.15 ml/100g brain tissue, interquartile range +0.08 to -0.28, P = 0.10). Oxidized cytochrome c oxidase decreased in 11/13 patients (median -0.27 mumol/l, interquartile range -0.19 to -0.44, P = 0.01). Our findings demonstrate an immediate step-response of heart rate and tcpCO2 to aminophylline in premature infants. The simultaneous reduction of cytochrome c oxidase in the brain cannot be explained as a consequence of changes in tcpCO2 or changes in cerebral blood volume. We therefore speculate that aminophylline interferes directly with cerebral metabolism.

Specificity of the Rhizobium-legume symbiosis obtained after mutagenesis in pea (Pisum sativum L.)

Within a set of 13 induced symbiotic pea (Pisum sativum L.) mutants, two distinct mutated genes sym25 and sym26, selected for ineffective nodulation have been counteracted in their effect by Rhizobium strains 254 and 94 respectively, thereby establishing an N₂ -fixing symbiosis. This suggests that mutagenesis can be a helpful tool in creating specificity systems such as those described in centres of origin and diversification of legume species.

Variant mitochondrial plasmids of broad bean arose by recombination and are controlled by the nuclear genome

Various cytoplasms of broad bean contain three mitochondrial plasmids (mtp1, 2 and 3), previously described. In cytoplasm 350 we have observed several additional mitochondrial plasmids, varying in number and in identity according to the nuclear background. Replacement of the nucleus by backcrossing led to the appearance or disappearance of additional plasmids, indicating that the nuclear genome controls either the creation or the copy level of mitochondrial plasmids. Analysis of eight variant additional plasmids (mtp4-11) suggests that they all result from a double recombination event between mtp1 and mtp2. In all cases, one recombination point was located within a 276-bp sequence, identical in both plasmids. For 7 plasmids, the region in which the second recombination event occurred could be narrowed down to a short stretch containing imperfect tandem repeats of a 31-bp motif. The largest sequence shared by the recombination regions was hexanucleotide GCGACG.

Insulin-like growth factors (IGF) I and II and IGF binding proteins (IGFBPs) in human colostrum/transitory milk during the first week postpartum: comparison with neonatal and maternal serum

Day 1 human colostrum contains 5 times more IGF I than IGF II. By day 3 postpartum, IGF I drops by 80% to constant levels whereas IGF II increases 3-fold up to day 7. Colostrum contains mainly IGFBP-2, little IGFBP-3 and no detectable IGFBP-1 or IGFBP-4. IGFBP-2 rises 20-fold up to day 6 of lactation. The major IGFBPs of newborn serum are IGFBP-2, -3 and -4. Early maternal serum contains only small amounts of IGFBP-2 and -3 and no detectable IGFBP-4. The pronounced differences between the IGFBP patterns of colostrum and early maternal serum suggest that IGFBP-2 does not pass from maternal blood into colostrum but is produced and secreted by mammary tissue itself. On the other hand, most of the IGF I, but not IGF II, in day 1 colostrum appears to stem from the maternal circulation.

[Unexpected thrombocytopenia in newborn infants]

Severe thrombopenia of the newborn involves appreciable morbidity and mortality. Effective treatment exists for all forms of neonatal thrombopenia. Swiftest possible correction of thrombopenia must be the prime aim of all measures. Delaying of effective treatment due to workup must be avoided. If there is suspicion of nAIT, effective results have been achieved with transfusion of irradiated and washed maternal thrombocytes, and with immunoglobulin therapy in the case of suspected thrombopenia due to maternal autoantibodies (ITP or SLE). Transfusion of unselected thrombocytes is the therapy of choice in non-immune thrombopenia, and in immune thrombopenias it serves as an emergency measure if there is a high bleeding risk.

[Fetal and neonatal alloimmune thrombocytopenia]

Alloimmune thrombocytopenia (AIT) in fetuses and newborn, a disease resembling Rh incompatibility, is caused by transplacental transfer of an IgG-class antibody against fetal platelets. In humans five different platelet antigen systems are so far known which lead to AIT. The disease occurs in 1:2000-1:5000 deliveries. In contrast to Rh disease, immunization occurs in the first pregnancy in the majority of cases. The main significance of AIT lies in the occurrence of fetal (-10%) and neonatal (-20%) intracranial hemorrhage. Newborns are treated with compatible platelets, if necessary in combination with immunoglobulins. The high rate of fetal intracranial hemorrhage justifies therapy during pregnancy as well. Antenatal measures include treatment of the mother with high-dose immunoglobulin, treatment of the fetus with immunoglobulin by cordocentesis, and fetal platelet transfusions. However, all therapeutic measures involving the fetus remain in the experimental stage at present. International cooperative studies are necessary to evaluate cost-benefit of intervention during pregnancy.

[Selection criteria and follow-up of children presenting with retinopathy of prematurity]

The recommendations of the American Academy of Pediatrics for eye examinations of premature infants are based on the following criteria: an age of gestation less than 35 weeks for infants having received oxygen or a birthweight under 1300 g with or without supplemental oxygen. The first examination should take place between the 5th and the 7th week of extra-uterine life, or prior to discharge of the hospital and repeated according to the first observations. It is specified that the examination must be done by a person experienced in neonatal ophthalmology and indirect ophthalmoscopy. In Zurich, following these recommendations, the criteria of the CRYO-ROP study, and our experience, we examine the infants with following features: (1) all premature infants with birthweight less than 1500 g independently of oxygen exposure, (2) neonates who have less than 35 gestational weeks and who were exposed in a FIO2 > 0.4 during more than 24 h. And (3) the first eye examination is done between the 5th and the 6th weeks of extra-uterine life. The follow-up of these children will depend on the primary state. The infants with ROP will be followed by the neonatal ophthalmologist as long as retinal complications can persist. Afterwards these infants will be controlled by the general ophthalmologist for the amblyopie prophylaxis (by anisomyopia or strabismus). Two controls during the first year, then one per year are advised in these cases. For children who had a cryocoagulation or an retinal detachment operation, the follow-up will be assured by the general ophthalmologist for the prevention of the amblyopia and by the neonatal ophthalmologist for the retina.

[Oxygen therapy and prematurity: lessons from the past]

The history of oxygen therapy in the newborn clearly demonstrates the importance of the methodology used in clinical research. It has revealed the tragic mistakes which haunt every clinician confronted with pathology of unknown etiology. It has allowed us to determine the relative strength of the methods used in the search for various etiologies: passive or active observation, retrospective or prospective study and prospective randomized controlled trial. In addition, history has illustrated the danger of utilization of statistical tests in the absence of controlled interventions. The aim of this paper is to familiarize the practising physician with the basic concepts of epidemiology. This should allow him to be a better judge of the quality of recommendations made by "authorities". In the future, clinical epidemiology should be an essential part of medical training.

Comparison between near infrared spectroscopy and 133Xenon clearance for estimation of cerebral blood flow in critically ill preterm infants

Estimations of cerebral blood flow were performed by both near infrared spectroscopy and 133xenon clearance on 12 occasions in nine critically ill premature infants (26-29 gestational wk) who required mechanical ventilation and supplemental oxygen. For each study, one determination of cerebral blood flow by 133xenon was compared with the mean of two to five measurements by near infrared done within 1-19 (median 5) h. 133Xenon measurements ranged from 9.6-16.9 mL/100 g/min, and mean near infrared measurements ranged from 8.6-25.0 mL/100 g/min. There was a significant correlation between the two sets of measurements (r = 0.80, p < 0.001). The mean difference between the methods was 1.6 mL/100 g/min, and the 95% limits of agreement were -0.5-3.8 mL/100 g/min. This study showed that cerebral blood flow can be measured noninvasively in critically ill premature infants at the cotside by near infrared spectroscopy and by the 133xenon clearance technique. The methods give comparable results.

Early pattern recognition in severe perinatal asphyxia: a prospective MRI study

On the basis of MRI examinations in 88 neonates and infants with perinatal asphyxia, we defined 6 different patterns on T2-weighted images: pattern A--scattered hyperintensity of both hemispheres of the telencephalon with blurred border zones between cortex and white matter, indicating diffuse brain injury; pattern B--parasagittal hyperintensity extending into the corona radiata, corresponding to the watershed zones; pattern C--hyper- and hypointense lesions in thalamus and basal ganglia, which relate to haemorrhagic necrosis or iron deposition in these areas; pattern D--periventricular hyperintensity, mainly along the lateral ventricles, i.e. periventricular leukomalacia (PVL), originating from the matrix zone; pattern E--small multifocal lesions varying from hyper--to hypointense, interpreted as necrosis and haemorrhage; pattern F--periventricular centrifugal hypointense stripes in the centrum semiovale and deep white matter of the frontal and occipital lobes. Contrast was effectively inverted on T1-weighted images. Patterns A, B and C were found in 17%, 25% and 37% of patients, and patterns D, E and F in 19%, 17% and 35%, respectively. In 49 patients a combination of patterns was observed, but 30% of the initial images were normal. At follow-up, persistent abnormalities were seen in all children with patterns A and D, but in only 52% of those with pattern C. Myelination was retarded most often in patients with diffuse brain injury and PVL (patterns A and D).

[Triplets and quadruplets in Switzerland, 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.