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Biomedical subjects

N Morling

Publications and source records attributed to N Morling.

At least 55 records · Page 3Linked to original sources
PubMed1996

Cord blood immunoglobulin E in like-sexed monozygotic and dizygotic twins.

Genetic and environmental factors have been implicated in the etiology of atopy and of serum IgE levels. In order to eliminate post-natal environmental influences we measured IgE in cord blood (CB-IgE) from a cohort of unselected, like-sexed twins. IgE determination was performed with a sensitive radioimmunoassay with a detection limit of 0.01 kU/l. Samples with contamination by maternal blood were identified by IgA determination and excluded. CB-IgE was evaluated in 29 monozygotic (MZ) and 28 dizygotic (DZ) twin pairs. The means and variances for IgE values were comparable for MZ and DZ twins when sex was controlled for. Placental anatomy (MZ twins with mono- and dichorial placenta and DZ twins with one or two placentae) had no significant influence on the IgE levels. In an analysis of variance with sub-sampling the among-pair, within-pair and analytical variance components were calculated. The analytical variance was well below the biological variances. Biometrical analysis showed that the best model by Akaike Information Criteria was a model including only additive genetic and non-shared environmental factors. With this model the heritability estimate was 0.8. These data suggest that the majority of the variation in CB-IgE is accounted for by genetic factors, but a substantial effect of a common environment cannot be excluded with the present sample size.

Cohort Studies↗
PubMed1996

Severe hemolysis caused by graft-derived anti-B production after lung transplantation.

Anti-B antibody causing sever hemolytic anemia and renal failure was found in the serum of a blood group B patient who had received a bilateral lung transplant from a blood group O donor. Although the donor origin of the antibody was not confirmed, it is likely that the anti-B antibody was produced by donor passenger B lymphocytes.

ABO Blood-Group System↗
PubMed1995

HLA-DQA1 typing in Danes by two polymerase chain reaction (PCR) based methods.

A total of 280 persons were HLA-DQA1 typed by two different polymerase chain reaction (PCR) based methods; (i) a reverse dot-blot (RDB) method, which can differentiate between six alleles, and (ii) a combined PCR-restriction fragment length polymorphism (PCR-RFLP) and allele-specific amplification (ASA) method, which together recognise eight alleles. In 146 unrelated Danish individuals, the HLA-DQA1 alleles were in Hardy-Weinberg equilibrium. For identity testing, the power of discrimination (PD) of HLA-DQA1 was 0.932 with the RDB method and 0.942 with the PCR-RFLP/ASA method. For paternity testing, the theoretical chance of exclusion in HLA-DQA1 of non-fathers was 0.634 with the RDB method and 0.660 with the PCR-RFLP/ASA method.

Alleles↗
PubMed1995

B-lymphoblastoid cell lines from multiple sclerosis patients and a healthy control producing a putative new human retrovirus and Epstein-Barr virus.

On several occasions we have observed retrovirus-like particles (RVLPs) by transmission electron microscopy (EM) of cultured T cells from a patient with MS. Later we established spontaneously formed B-lymphoblastoid cell lines (LCLs) from a patient with an MS-like disease and from another patient with MS who had a reactivated Epstein-Barr virus (EBV) infection. Both LCLs were found by EM to produce RVLP and EBV particles. Reverse transcriptase (RT) assays were positive in purified viral material from both LCLs. To substantiate these findings we initiated an intensified culturing procedure and were able to establish LCLs from 5 out of 21 consecutive MS patients and 1 out of 13 consecutive healthy controls. All LCLs were found to produce both RVLP and EBV particles by EM. Whether the putative new retrovirus(es) and EBV have any causal relationship to MS is still not known, but the findings support this possibility.

Adult↗
PubMed1995

PCR typing of two short tandem repeat (STR) structures upstreams of the human myelin basic protein (MBP) gene; the genetic susceptibility in multiple sclerosis and monosymptomatic idiopathic optic neuritis in Danes.

We investigated two short tandem tetranucleotide (TGGA) repeat polymorphisms upstreams of the myelin basic protein (MBP) gene. The region was amplified by the polymerase chain reaction (PCR) and the two repeat systems were separated by cutting with the restriction enzyme NlaIII. The lengths of the DNA fragments were analyzed by vertical electrophoresis in polyacrylamide gels followed by silver staining. We compared the DNA fragment frequencies of the two MBP regions in 34 patients suffering from multiple sclerosis and in 78 suffering from monosymptomatic idiopathic optic neuritis to those in 200 healthy controls. We found no significant differences between the MBP fragment frequencies in either of the patient groups and in the control group.

Alleles↗
PubMed1994

An investigation of the HUMVWA31A locus in British Caucasians.

A number of short tandem repeat (STR) loci are currently being examined for their usefulness as markers of identity; HUMVWA31A is one such locus. We used a high-sieving agarose technique to type 200 British Caucasians for this locus. Comparison of the resultant allele frequencies with other published databases showed that their distributions were similar. Observed heterozygosity was similar to that reported in other population studies but significantly lower than expected. A goodness of fit analysis of observed and expected genotypes was highly significant, suggesting a deviation from Hardy-Weinberg equilibrium, although reports from other populations appeared not to show such differences. The possibility that mistyping had led to an erroneous statistic was investigated by detailed examination of samples within our own laboratory and in two other laboratories, involving verification of the agarose typing by both automated fluorescent detection techniques, and sequencing. Other reported deviations from Hardy-Weinberg equilibrium in STR systems are discussed.

Alleles↗
PubMed1994

PCR typing of DNA fragments of the short tandem repeat (STR) system HUMTH01 in Danes and Greenland Eskimos.

DNA from the short tandem repeat (STR) system HUMTH01 was amplified by the polymerase chain reaction (PCR) and analyzed by vertical electrophoresis in polyacrylamide gels followed by silver staining. DNA samples from 100 unrelated Danes, 147 unrelated Greenland Eskimos, and 89 Danish mother/child pairs were analyzed. Significant differences were observed between the distribution of fragments ('alleles'), whereby allele number 7 was considerably more frequent in Eskimos (0.687) than in Danes (0.201). The distributions of HUMTH01 phenotypes were in Hardy-Weinberg equilibrium in both the Eskimo and Danish populations. In the 89 Danish mother/child pairs, the segregation of the HUMTH01 genotypes was in accordance with the genetic model of co-dominant inheritance and no mutations were found. In a blind trial, DNA samples from 40 unrelated Danes were investigated by one of us in Copenhagen, at the FBI Forensic Science Research and Training Center (FSRTC), Quantico, and at the Institut für Rechtsmedizin, Münster, Germany. Concordant HUMTH01 types were found in 39 out of 40 individuals. The allele which led to discrepant typing results was assigned type 9.3 in two laboratories and type 10 in one laboratory.

Alleles↗
PubMed1994

Graft-derived anti-HPA-2b production after allogeneic bone-marrow transplantation.

We report on a male who received a bone-marrow allograft from his HLA identical sister for acute myelogenous leukaemia. After transplantation, the patient suffered from refractoriness to the transfusions of HLA-matched platelets and a strong platelet-specific antibody, anti-HPA-2b, of IgG1 subclass was demonstrated in the patient's serum. In the serum of the bone-marrow donor a weak IgG1 anti-HPA-2b was demonstrated. IgG allotyping of the patient and donor showed identical results. We could not determine the origin of the anti-HPA-2b, although we hypothesize that the anti-HPA-2b was produced by immunocompetent donor lymphocytes infused with the suspension of bone-marrow cells.

Antigens, Human Platelet↗
PubMed1994

DNA polymorphism of HLA class II genes in systemic lupus erythematosus.

We investigated the DNA restriction fragment length polymorphism (RFLP) of the major histocompatibility complex (MHC) genes: HLA-DRB, -DQA, -DQB, -DPB in 24 Danish patients with systemic lupus erythematosus (SLE) and in 102 healthy Danes. A highly significant increase of the frequency of the DR3- and DRw6-associated 7.00 kb DRB TaqI DNA fragment was found in SLE patients compared to normal controls (83.3% vs 35.5%; RR = 9.1, p < 10(-4). The frequencies of the DQA1*0501-associated 4.56 kb DQA TaqI fragment and the DRB3*01/03-associated 9.79 kb TaqI fragment were also found to be significantly increased in SLE patients (70.8% vs 29.7%; RR = 5.8, p < 10(-2) for the DQA fragment and 70.8% vs 36.1%; RR = 4.3, p < 0.05 for the DRB3 fragment). Less extensive and insignificant increases of the frequencies of the DR3-associated DQB and DPB fragments were observed. The frequencies of the DR2-associated DRB, DQA, and DQB fragments were comparable to those found in normal controls.

DNA↗
PubMed1994

Group specific component in serum and otosclerosis: no association.

An earlier Swedish study suggested a positive association between otosclerosis and the group-specific component GC*1F marker. We investigated the distribution of GC subtypes in 101 Danish patients with otosclerosis who all had surgery performed in the county of Funen. Compared to 1674 Danish controls we found no evidence of any association between markers from the GC serum protein system and otosclerosis.

Female↗
PubMed1993

Paternity testing with VNTR DNA systems. I. Matching criteria and population frequencies of the VNTR systems D2S44, D5S43, D7S21, D7S22, and D12S11 in Danes.

Paternity testing using DNA polymorphism of variable numbers of tandem repeat (VNTR) regions with restriction fragment length polymorphism (RFLP) was implemented. HinfI-digested DNA was separated by electrophoresis in agarose gels and hybridized with radiolabelled probes detecting the VNTR-systems D2S44 (YNH24), D5S43 (MS8), D7S21 (MS31), D7S22 (g3), and D12S11 (MS43a). The intra gel variability of 970 duplicate investigations on the same gel of DNA from 122 individuals showed no differences exceeding 1.25 mm between the positions of the corresponding DNA fragments. The comparison of 1,624 DNA fragments from 342 mother/child pairs showed only one difference above 1.25 mm which was interpreted as a mutation. Based on these observations, we decided to consider an intra gel difference above 1.25 mm between the non-maternal DNA fragment of the child and the nearest DNA fragment of the putative father as an exclusion in paternity testing. This matching criterion was used for the comparisons of 1,197 DNA fragment differences in 247 pairs of children and putative fathers who had not been excluded by conventional marker systems. In all of these cases, the migration differences between the DNA fragments of non-excluded men and the DNA fragments of the children were less than 1.25 mm except in 6 cases (0.5%). The man/child differences in all of 227 false trios exceeded 1.25 mm in 2 or more of the 5 VNTR systems investigated. Matching criteria for inter gel comparisons in paternity testing were established. The frequency distribution of HinfI digested DNA fragments of the 5 VNTR systems in 650 unrelated Danes is presented and the raw data is available.

Adult↗
PubMed1993

Paternity testing with VNTR DNA systems. II. Evaluation of 271 cases of disputed paternity with the VNTR systems D2S44, D5S43, D7S21, D7S22, and D12S11.

Paternity testing was carried out in 271 cases of disputed paternity using the 5 VNTR systems D2S44 (YNH24), D5S43 (MS8), D7S21 (MS31), D7S22 (g3), and D12S11 (MS43a), and 10-15 conventional marker systems including the HLA-A,B system. By means of the matching criteria for the VNTR systems established elsewhere (Morling & Hansen 1992), all 70 unrelated men who had been excluded by conventional typing were also excluded with 2 or more VNTR systems. Based on the observed exclusion frequencies for the 5 VNTR systems, a theoretical exclusion rate exceeding 0.999 could be obtained. A total of 350 father/child pairs were studied and in 3 paternity cases and one immigrant family, the alleged fathers were excluded solely by one of the 5 VNTR systems possibly reflecting mutations. No mother/child exclusions were observed among 350 mother/child pairs. Linkage analysis between the syntenic systems D7S21 (MS31) and D7S22 (g3) was performed in 29 informative families with 81 children and revealed a recombination distance of about 31 cM. The positive evidence for paternity provided by the 5 VNTR systems in cases with non-exclusions is discussed.

Adult↗
PubMed1993

Genetic investigations in immigration cases and frequencies of DNA fragments of the VNTR systems D2S44, D5S43, D7S21, D7S22, and D12S11 in Turks.

We have included investigations of the DNA polymorphism of variable numbers of tandem repeat (VNTR) regions with restriction fragment length polymorphism (RFLP) in the genetic evaluations in immigrant cases. HinfI-digested DNA was separated by electrophoresis in agarose gels and hybridized with radiolabelled probes detecting the VNTR systems D2S44 (YNH24), D5S43 (MS8), D7S21 (MS31), D7S22 (g3), and D12S11 (MS43a). We used the matching criterion for paternity testing for the parent/child comparisons, i.e. non-match if the intra gel difference exceeded 1.25 mm. A total of 43 immigration cases involving mainly Turks were investigated with DNA technique in parallel with investigations of 10-15 conventional systems. One man was excluded from paternity by both conventional and DNA investigations. Non-exclusion was observed with both conventional and DNA systems in 97 putative mother/child pairs and in 96 putative father/child pairs. In a putative father/child combination with non-exclusion in 18 genetic systems, a single genetic inconsistency ('exclusion') in D7S21 (MS31) was observed. The frequency distributions of HinfI digested DNA fragments of the five VNTR systems in 105 Turks are presented.

Adult↗
PubMed1993

Analysis of the locus D1S80 by amplified fragment length polymorphism technique (AMP-FLP). Frequency distribution in Danes. Intra and inter laboratory reproducibility of the technique.

DNA from the locus D1S80 was amplified by polymerase chain reaction (PCR) and analyzed by electrophoresis in vertical polyacrylamide gels followed by silverstaining. DNA samples from 119 unrelated Danes and 97 mother/child pairs were examined. The amplified fragment length polymorphism (AMP-FLP) analysis of the D1S80 locus demonstrated 21 alleles and a heterozygosity of 77%. Of the 231 possible phenotypes, 57 were observed. All mother/child pairs shared at least one D1S80 allele. The D1S80 typing results in 70 Danes were compared to the results obtained on the same samples in another laboratory and the results were concordant in all cases.

Adult↗