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Biomedical subjects

M B Petersen

Publications and source records attributed to M B Petersen.

At least 127 records · Page 7Linked to original sources
PubMed1990

Clinical, cytogenetic, and molecular genetic characterization of two unrelated patients with different duplications of 21q.

We present 2 patients with dup(21q). Patient MP01 had mild mental retardation, facial findings characteristic of Down syndrome (DS), and a terminal duplication of chromosome 21. His karyotype was 46,XY,dup(21) (q22.1-qter). Patient MP03 had mild mental retardation, minor anomalies not characteristic of DS, and a duplication of the proximal long arm of chromosome 21, karyotype 46,XX,dup(21) (q11.2-q21.2). The patients were studied with single-copy DNA sequences from 20 loci on chromosome 21 to characterize the extent of the duplicated regions at the DNA level. DNA loci from D21S55 to COL6A1 were triplicated in patient MP01 while loci from D21S13 to D21S8 were triplicated in patient MP03. Our results support the hypothesis of a critical region of chromosome 21, which in triplicate is responsible for many of the facial changes associated with DS. Other genes outside this region may also contribute to other abnormalities observed in DS.

Adult↗
PubMed1990

Linkage mapping of the highly informative DNA marker D21S156 to human chromosome 21 using a polymorphic GT dinucleotide repeat.

A (GT)n repeat within the anonymous DNA sequence D21S156 was shown to be highly polymorphic in DNA from members of the 40 CEPH families. At least 12 alleles of this locus were recognized by electrophoresis on polyacrylamide gels of DNA amplified by the polymerase chain reaction (PCR) using primers flanking the (GT)n repeat. The polymorphism information content was 0.82. PCR amplification of DNA from somatic cell hybrid lines mapped D21S156 to human chromosome 21 and linkage analysis localized this marker close to the loci ETS2, D21S3, and HMG14 on chromosomal band 21q22.3. This polymorphism is highly informative and can serve as an anchor locus for human chromosome 21.

Alleles↗
PubMed1990

Linkage analysis of the human HMG14 gene on chromosome 21 using a GT dinucleotide repeat as polymorphic marker.

A (GT)n repeat in intron 4 of the functional human HMG14 gene on chromosome 21 was used as polymorphic marker to map this gene relative to the genetic linkage map of human chromosome 21. Variation in the length of the (GT)n repeat was detected by electrophoresis on polyacrylamide gels of DNA amplified by the polymerase chain reaction using primers flanking the repeat. The observed heterozygosity of this polymorphism in 40 CEPH families was 58% with six different alleles. Linkage analysis localized the HMG14 gene close to the ETS2 gene and locus D21S3 in chromosomal band 21q22.3.

Chromosomes, Human, Pair 21↗
PubMed1990

Does sulfation of gastrin influence gastric acid secretion in man?

To assess the physiologic significance of tyrosine o-sulfation of gastrin in humans, the gastric acid stimulatory potencies of sulfated and non-sulfated human gastrin-17 were compared in six normal young subjects. Sulfated and non-sulfated forms of synthetic human gastrin-17 were infused intravenously in doses from 12.7 to 478 pmol/kg/h. Similar acid secretory responses were observed. The calculated maximal acid response for sulfated gastrin-17 was 35.7 +/- 4.3 mmol/h, and that for non-sulfated gastrin-17 was 39.8 +/- 7.5 mmol/h (mean +/- SEM, NS). The 50% effective dose of sulfated gastrin-17 was 22.2 +/- 6.7 pmol/kg/h, whereas it was 29.3 +/- 5.8 pmol/kg/h for non-sulfated gastrin-17 (NS). Finally, the 50% effective concentration of gastrin in serum was 34.7 +/- 5.0 pmol sulfated gastrin-17/l and 42.5 +/- 11.8 pmol non-sulfated gastrin-17/l (NS). The results show that tyrosine o-sulfation is without significant influence on the gastric acid secretory potency of gastrin in man. Moreover, the results also suggest that sulfated and non-sulfated gastrin-17 in man have similar rates of metabolism.

Adult↗
PubMed1990

Status at four years of age in 280 children weighing 2,300 g or less at birth.

To assess the functional ability in low birth weight children at age 4-5, 114 survivors with very low birth weight (VLBW) less than or equal to 1,500 g, 166 survivors with birth weight 1,501-2,300g (LBW), and 115 comparison children with normal birth weight (NBW) were enrolled in a follow-up study. Twenty-four (21%) VLBW and 11 (6.6%) LBW-children had major clinical abnormalities compared to 1 (0.9%) of the NBW children. Twenty-two percent of the VLBW-children were below the 3rd-centile for height and weight. Fewer VLBW than LBW-children were neurologically and ophthalmologically normal. Even after exclusion of the handicapped children, the LBW as well as the VLBW children scored significantly lower than the NBW children in the McCarthy Scales of Children's Abilities, most markedly in the motor and perceptual performance scales. A simple test using grooved pegs clearly demonstrated the poor visual-motor integration in VLBW and LBW children. A marked difference between the NBW and the two LBW groups was seen in a qualitative evaluation of motor performance. Only 5% of VLBW children scored at or above the median for the NBW in all of three fields: general cognitive, motor performance, and pegboard, as opposed to 11% of LBW and 18% of NBW children. Neither sex, age corrected for prematurity, nor psycho-social background factors explained the differences between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMed1990

Analysis of DNA polymorphisms suggests that most de novo dup(21q) chromosomes in patients with Down syndrome are isochromosomes and not translocations.

Down syndrome is rarely due to a de novo duplication of chromosome 21 [dup(21q)]. To investigate the origin of the dup(21q) and the nature of this chromosome, we used DNA polymorphisms in 10 families with Down syndrome due to de novo dup(21q). The origin of the extra chromosome 21q was maternal in six cases and paternal in four cases. Furthermore, the majority (eight of 10) of dup(21q) chromosomes were isochromosomes i(21q) (four were paternal in origin, and four were maternal in origin); however, in two of 10 families the dup(21q) chromosome appeared to be the result of a Robertsonian translocation t(21q;21q) (maternal in origin in both cases).

Chromosome Aberrations↗
PubMed1989

Molecular genetic approach to the characterization of the "Down syndrome region" of chromosome 21.

The cytogenetically defined "Down syndrome region" of chromosome 21 has been characterized by DNA analysis in patients with partial trisomy 21 with or without Down syndrome features. Single-copy DNA sequences mapped on chromosome 21 were used to determine copy number by polymorphism and/or dosage analysis in the patients. Given our results, which in some patients were in disagreement with their cytogenetic descriptions, trisomy for locus D21S13 through locus D21S58 is excluded from significant contribution to many Down syndrome features. The minimal chromosome region necessary in triplicate to result in the Down syndrome phenotypes in the patients characterized includes the area from locus D21S55 to locus COL6A1. We could not analyze the region between loci D21S58 and D21S55 and between COL6A1 and 21qter at the molecular level due to a lack of DNA probes and, consequently, the contribution of these areas to a Down syndrome phenotype when present in three copies is unknown. The molecular cloning and mapping of chromosome 21 and the expansion of the patient population studied will likely result in a more precise molecular definition of the Down syndrome region.

Blotting, Southern↗
PubMed1989

Using patient satisfaction data: an ongoing dialogue to solicit feedback.

Satisfying interactions between caregivers and their patients reflect the degree of respect inherent in the interactions between caregivers and their leaders. Leaders who want caregivers to be primarily accountable for improving patient satisfaction must continually ask caregivers this question: "What can I do to make things better for you?" Caregivers in turn will solicit the same type of feedback from their patients, with every interaction viewed as an opportunity to improve satisfaction.

Consumer Behavior↗
PubMed1989

A case of the ring 20 syndrome.

A 4-year-old child with a ring 20 chromosome mosaicism, low grade developmental delay, and seizures is described.

Chromosome Aberrations↗
PubMed1988

Early growth delay in diabetic pregnancy: relation to psychomotor development at age 4.

Ninety nine consecutive insulin dependent and 101 non-diabetic pregnant women were examined by ultrasonograph to assess early fetal growth. In 42 of the diabetic mothers and three of the non-diabetic mothers the scan showed early intrauterine growth delay. At 4-5 years of age all children available for study were evaluated by the Denver developmental screening test. Only 23 of the 34 children of diabetic mothers with early intrauterine growth delay had normal test scores compared with 46 of the 50 children of diabetic mothers with normal intrauterine growth. The children failed in personal-social development, gross motor development, and particularly in language and speech development. Children of diabetic mothers with normal early fetal growth had scores very similar to those of the children of non-diabetic mothers, of whom 76 of the 86 tested had normal scores. This study suggests that children with a history of growth delay in early diabetic pregnancy should be screened for possible developmental impairment.

Adult↗
PubMed1987

Fatty acid composition of subcutaneous adipose tissue in mother-infant pairs.

The fatty acid composition of microsamples from 10 AGA term, 8 SGA term, 7 AGA preterm and 4 SGA preterm, 2-4 day old infants and their mothers were analyzed. In AGA preterm newborns the mean percent of palmitic and stearic acid was lower and the mean percent of linoleic acid was higher than in AGA term infants indicating that there is an increase in fatty acids derived by synthesis from glucose throughout gestation. SGA infants had relative amounts of palmitic and stearic acid similar to what was found in AGA term infants. This indicates that the enzymes involved in synthesis of fatty acids from glucose are intact in intrauterine growth retardation (IUGR). The absolute amount of adipose tissue and fatty acids, however, is smaller in SGA infants due to a reduced availability of glucose in IUGR gestation. No differences were found in the fatty acid composition of subcutaneous adipose tissue from the mothers in the 4 groups. All mothers had a lower mean percent of palmitic and stearic acid and a higher mean percent of oleic and linoleic acid than their infants, ensuring a transplacental gradient to the fetus of this latter essential fatty acid. The fatty acid composition of plasma free fatty acids generally reflected the composition of the subcutaneous adipose tissue in the infants.

Adipose Tissue↗
PubMed1987

New assignment of the adenosine deaminase gene locus to chromosome 20q13 X 11 by study of a patient with interstitial deletion 20q.

A karyotype 46,XY,del(20)(q11 X 23q13 X 11) was found in a three year old boy with mental and growth retardation, low set ears, broad nasal bridge, and macrostomia. Adenosine deaminase (ADA) activity was reduced by about 50%, assigning the gene locus to the deleted segment. A review of the previously reported regional assignments suggests that the ADA gene is in the region of band 20q13 X 11.

Adenosine Deaminase↗
PubMed1987

Interstitial deletion 1p in a 30 year old woman.

High resolution chromosome analysis showed the karyotype 46,XX,del(1)(p22.1 p31.2) in a 30 year old woman with psychomotor retardation and various malformations. Determination of the enzyme phosphoglucomutase 1 (PGM1) showed that she was a heterozygote. Three other cases of interstitial deletion 1p have been reported previously, and one of these cases had several features in common with our case, suggesting a distinct syndrome.

Abnormalities, Multiple↗
PubMed1987

Full trisomy 22 in a newborn infant.

Karyotype 47,XY,+22 was found in a newborn infant with primitive and low-set ears, bilateral preauricular pit, broad nasal bridge, antimongoloid palpebral fissures, macroglossia, enlarged sublingual glands, cleft palate, micrognathia, clinodactyly of the fifth fingers, hypoplastic finger nails, hypoplastic genitalia, short lower limbs, bilateral sandal gap and deep plantar furrows. The child developed signs of congenital heart disease and died at the age of 10 weeks. Non-disjunction studies showed maternal origin (meiosis I) of the extrachromosome.

Adult↗