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Biomedical subjects

M B Petersen

Publications and source records attributed to M B Petersen.

142 records · Page 8Linked to original sources
PubMed1986

Status at two years in 121 very low birth weight survivors related to neonatal intraventricular haemorrhage and mode of delivery.

All 121 infants with birthweight less than or equal to 1500 g (VLBW) discharged from our department through an 18-month period were followed up at two years of age. All but 10 infants were examined by cranial ultrasound scanning in the neonatal period. Six had died after discharge; and of these two had severe brain damage following neonatal intraventricular haemorrhage. Twelve children had definite neuromotor abnormality; of these, the nine children with spastic types of cerebral palsy had all been delivered vaginally. Of the remaining children, one half had at least one neurodevelopmental symptom suggesting perinatal brain damage. Outcome was associated to neonatal intraventricular/subependymal haemorrhage when complicated by ventricular dilatation. Outcome in children with simple haemorrhage was similar to that in children without haemorrhage. The association between outcome and haemorrhage was considerably reduced by simultaneously considering the associations of gestational age at birth and the use of mechanical ventilation in the neonatal period. Head circumference at follow-up was greatest in those children with haemorrhage complicated by ventricular dilatation, when adjusted for actual body weight, birth weight, and gestational age at birth.

Cerebral Hemorrhage↗
PubMed1986

Trisomy 14 mosaicism in a 2 year old girl.

Trisomy 14 mosaicism with 6% trisomic cells in blood and 16% in skin fibroblasts was found in a 2 year 2 month old girl with mild psychomotor retardation, craniofacial dysmorphism, pectus carinatum, curved fifth fingers, retarded bone age, and signs of an ASD. These findings are consistent with the previously reported cases of trisomy 14 mosaicism and support the suggested existence of a distinctive syndrome. Non-disjunction studies showed that the extra chromosome 14 originated from either a second paternal meiotic error or an early mitotic error.

Adolescent↗
PubMed1985

Changes in plasma lipoproteins from first day to third week of life in healthy breast-fed infants. I. Lipid and protein composition of lipoproteins.

Plasma lipoproteins were measured in seven healthy breast-fed infants three times during the first and on the third, sixth and twenty-first days of life. Plasma total beta-lipoprotein, very low density and low density lipoprotein increased three times during the first week of life. Plasma total apolipoprotein A-I and high density lipoprotein increased twice between the first and third week of life. These dramatic changes in plasma lipoprotein concentrations during the neonatal period can best be explained by the effect of feeding.

Age Factors↗
PubMedDate not supplied

Rare chromosome 20 variants encountered during prenatal diagnosis.

A case with an uncommon heteromorphism in the centromeric region of chromosome 20, var (20) (cen, CBG 50), and a family with a pericentric inversion of chromosome 20, inv (20) (p11.23qll.21), are reported, both detected in amniotic fluid cell cultures. It appears that small pericentric inversions of chromosome 20 have a low risk of recombination.

Adult↗
PubMedDate not supplied

Origin of nondisjunction in trisomy 8 and trisomy 8 mosaicism.

Causes of chromosomal nondisjunction is one of the remaining unanswered questions in human genetics. In order to increase our understanding of the mechanisms underlying nondisjunction we have performed a molecular study on trisomy 8 and trisomy 8 mosaicism. We report the results on analyses of 26 probands (and parents) using 19 microsatellite DNA markers mapping along the length of chromosome 8. The 26 cases represented 20 live births, four spontaneous abortions, and two prenatal diagnoses (CVS). The results of the nondisjunction studies show that 20 cases (13 maternal, 7 paternal) were probably due to mitotic (postzygotic) duplication as reduction to homozygosity of all informative markers was observed and as no third allele was ever detected. Only two cases from spontaneous abortions were due to maternal meiotic nondisjunction. In four cases we were not able to detect the extra chromosome due to a low level of mosaicism. These results are in contrast to the common autosomal trisomies (including mosaics), where the majority of cases are due to errors in maternal meiosis.

Child↗
PubMedDate not supplied

Scratch induction in the rat by intradermal serotonin: a model for pruritus.

Eight substances (histamine, compound 48/80, kallikrein, trypsin, papain, substance P, serotonin and platelet activating factor) were injected intradermally (volume 50 microl) into the rostral back (neck) of rats in order to establish an animal model for peripherally elicited pruritus. While serotonin induced excessive scratching at the site of injection, the other substances were weak or inactive. The dose-response relationship of serotonin was sigmoid, EC50=2.1 mg/ml (95% confidence interval: 1.0 to 4.3 mg/ml). Injections of serotonin 1 mg/ml into the caudal back elicited no scratching at all, i.e. neither at the site of injection nor elsewhere, so the experiment indicated no systemic effect of serotonin 1 mg/ml intradermally. Scratching was probably elicited histamine-independently, since histamine itself did not elicit scratching. The intra- and inter-observer variations were 3-4%. We conclude that serotonin is a reproducible local pruritogen eliciting scratching in the rat. The model may be useful in research and development of topical antipruritics of the nonhistaminic type as well as for various other purposes in pruritus research.

Animals↗
PubMedDate not supplied

Detection of penicillin resistance in Streptococcus pneumoniae by diffusion tests.

Four different diffusion tests used to detect penicillin resistance in Streptococcus pneumoniae were evaluated for 34 penicillin-susceptible pneumococci (MIC < 0.1 microgram/ml), 35 intermediate pencillin-resistant (MIC 0.1-1.0 microgram/ml) and 23 penicillin-resistant strains (MIC > 2 micrograms/ml). The 1 microgram oxacillin disk from AB Biodisk, the 1 microgram oxacillin Neo-Sensitabs from Rosco, the 5 micrograms penicillin Low Neo-Sensitabs and the penicillin E test were tested on Mueller-Hinton blood agar, PDM Antibiotic Sensitivity Medium II supplemented with blood, and Danish Blood Agar. MICs obtained by the agar dilution method were used as reference. The 1 microgram oxacillin AB Biodisk was able to separate all the penicillin-susceptible pneumococci correctly from those with reduced penicillin susceptibility (MIC > or = 0.1 microgram/ml), whereas use of the 1 microgram oxacillin Neo-Sensitabs resulted in high frequencies (14-29%) of intermediate penicillin-resistant strains interpreted as penicillin susceptible. The 5 micrograms penicillin Low Neo-Sensitabs proved completely useless for detecting penicillin resistance in pneumococci. High rates of agreement (82-93%) were found between the penicillin E test and the reference MIC determination method on all the tested media.

Diffusion↗
PubMedDate not supplied

Analysis of the origin of the extra chromosome in trisomy 8 in 4 cases of spontaneous abortions.

OBJECTIVE: To determine the origin of the extra chromosome in trisomy 8 in spontaneous abortions. METHODS: We analyzed 4 cases of nonmosaic trisomy 8 in 1st-trimester spontaneous abortions and their parents with DNA polymorphism analysis using microsatellite DNA markers. RESULTS: In 3 cases the extra chromosome was maternal in origin and in 1 case paternal in origin. In 2 of the cases the nondisjunction had occurred in maternal meiosis, while the other 2 cases were consistent with a postzygotic (mitotic) origin of the additional chromosome. CONCLUSION: Although a small number of cases studied, these results suggest differences from the common autosomal trisomies 21, 18, 16, and 13 where the vast majority of cases are due to errors in maternal meiosis.

Abortion, Spontaneous↗
PubMedDate not supplied

Prelingual nonsyndromic hearing loss in Greece. Molecular and clinical findings.

Mutations in the gene encoding the gap-junction protein connexin 26 (GJB2) on chromosome 13q11 have been shown as a major contributor to prelingual, sensorineural, nonsyndromic deafness. One specific mutation, 35delG, has accounted for the majority of the mutations detected in the GJB2 gene in Caucasian populations and is one of the most frequent disease mutations identified so far with highest carrier frequency of 3,5% in the Greek population. In a collaboration with the major referral centers for childhood deafness in Greece, patients were examined by an extensive questionnaire to exclude syndromic forms and environmental causes of deafness and by allele-specific PCR for the detection of the 35delG mutation. The 35delG mutation was found in 32.1% of the alleles in 173 unrelated cases of prelingual deafness: 50 homozygotes and 11 heterozygotes. Individuals heterozygous for the 35delG mutation were further analyzed by direct genomic sequencing of the coding region of the GJB2 gene, which revealed R184P and 486insT mutations in single alleles. We conclude that the 35delG GJB2 mutation is responsible for one third of prelingual, sensorineural deafness in Greece, which is higher than the usually quoted 20% for Caucasian populations.

Audiometry, Pure-Tone↗