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Biomedical subjects

G Duc

Publications and source records attributed to G Duc.

At least 37 records · Page 2Linked to original sources
PubMed1995

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).

Administration, Oral↗
PubMed1994

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.

Artifacts↗
PubMed1994

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.

Anemia, Neonatal↗
PubMed1994

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.

Aminophylline↗
PubMed1994

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.

Birth Weight↗
PubMed1993

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.

Base Sequence↗
PubMed1993

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.

Breast Feeding↗
PubMed1993

[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.

Diagnosis, Differential↗
PubMed1993

[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.

Blood Platelets↗
PubMed1993

[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.

Epidemiologic Methods↗
PubMed1993

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).

Asphyxia Neonatorum↗
PubMed1993

[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.

Amblyopia↗