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B Mevåg

Publications and source records attributed to B Mevåg.

At least 19 recordsLinked to original sources
PubMed2001

Microsatellite stability in human post-mortem tissues.

Human identification and forensic criminal casework may involve DNA profiling of decomposed material. Somatic microsatellite (STR) instability may lead to false exclusions and theoretically to false inclusions, both in criminal cases and in human identification. Hence, the somatic and postmortal stability of the actual sequences is crucial to the reliability of such analyses. Somatic STR stability in human tissues has been documented in small series only and the effect of postmortal tissue decomposition on microsatellite stability remains to be elucidated. On this basis, we have systematically searched for somatic STR mutations in 26 deceased humans without signs of decomposition at autopsy and 25 autopsy cases with obvious signs of postmortal decomposition. A blood sample and six tissue samples were collected from each case. Seven STRs were chosen for study, the tetranucleotides HUMVWA31/A, HUMTH01, HUMF13A1, and HUMFES/FPS, and the hyperpolymorphic markers HUMAPOAI1, D11S554 and HUMACTBP2. Denaturing gel electrophoresis was performed on an ABD Prism 377 gene sequencer with Genescan 672 software (Applied Biosystems, Inc.). The bone DNA profile of each case was chosen as the standard DNA profile. All cases gave profiles from additional tissues. By intraindividual comparison of DNA profiles in the cases without signs of degradation we find that the short repetitive sequences under study are stable, that is without evidence of somatic mutations. The cases with varying degree of decomposition display postmortal microsatellite stability, we detect no somatic mutations or other possible postmortal changes that could lead to between-organ non-matches. In conclusion, PCR-based STR analyses are suitable in human identification and forensic casework dealing with different tissues, even when the substrate is heavily decomposed.

Autopsy↗
PubMed1999

Extraction of DNA from decomposed human tissue. An evaluation of five extraction methods for short tandem repeat typing.

Hyperpolymorphic short tandem repetitive DNA sequences, STRs or microsatellites, have become widely used in human identification, particularly in criminal cases and in mass disasters. In such cases the substrates for the analyses may be decomposed biological material, a fact that has to be taken into account when choosing the appropriate casework methods. In this paper we report the evaluation of five different DNA extraction methods, namely the phenol-chloroform, the silica based, the InstaGene Matrix (BioTest), the glass fiber filter, and the Chelex based methods. The substrates for the analyses are decomposed human liver tissue specimens from forensic autopsy cases. Extracted DNA was quantified and DNA profiled by a set of seven STRs. We have compared laboratory time consumption and costs of the five methods, showing that the Chelex method is the more rapid and less expensive of the methods, the phenol-chlorophorm and silica extractions being the most time consuming and resource demanding ones. A full profile was obtained by the silica method in nine out of ten cases and this method failed to give a reliable type in four out of 70 STR analyses. The phenol-chlorophorm and the glass fiber filter methods failed in 16 analyses, the InstaGene Matrix (BioTest) in 25 and the Chelex extracts in 56 of the 70 STR analyses. By multiple logistic regression we show that the difference between the silica procedure and the other methods are statistically significant. In our hands, the silica gel extraction procedure is an obvious choice when the biological material available is decomposed human tissue--even if this procedure is one of the more laborious ones.

Autolysis↗
PubMed1997

Identification by DNA analysis of the victims of the August 1996 Spitsbergen civil aircraft disaster.

Disaster victim identification traditionally relies on the combined efforts of police, dentists and pathologists, comparing ante mortem (AM) information from the missing persons with post mortem (PM) data from the dead bodies. In Western countries, dental evidence has ordinarily played the major role. DNA analysis has been used successfully in a number of large accidents to associate body parts and for purposes of identification, by comparing victims' DNA profiles with those of relatives. However, DNA typing is still not generally regarded as an essential part of disaster victim identification. Facing the August 1996 Spitsbergen aircraft accident in which 141 Russians and Ukrainians died and anticipating scanty ante mortem dental data, it was decided to use DNA profile analysis as the primary identification method. Material collected at the scene from all body parts, and blood sample from relatives were analysed at eight polymorphic microsatellite and minisatellite loci, DNA profile comparisons enabled us to sort the 257 typed body parts into 141 individuals, as well as identifying the 139 victims for whom reference samples were available. Identification by DNA analysis was then followed by comparisons of traditional AM and PM data, and within day 20 of the accident the identities of all victims were confidently established. This investigation indicates that it might be feasible to replace traditional identification efforts with DNA typing.

Aircraft↗
PubMed1996

Report on the third EDNAP collaborative STR exercise. European DNA Profiling Group.

This report describes an inter-laboratory exercise completed on behalf of the European DNA Profiling (EDNAP) group. The exercise is one in a series designated to identify STR loci which could be used for harmonisation between participating European forensic science laboratories. Participants were asked to identify the alleles present in five bloodstains at the STR loci HUMTHO1 and HUMVWFA31/A. Two of the stains were prepared from mixtures of two different blood samples. There were no special instructions and each laboratory was requested to use the methodology normally employed for crime case investigations. All participating laboratories achieved the same results for both loci. In addition, the laboratories were also requested to report the results obtained from any other loci which would normally be used in crime case investigations. A comparison of these results showed some inter-laboratory variation.

Alleles↗
PubMed1996

Genetics of the Berardinelli-Seip syndrome (congenital generalized lipodystrophy) in Norway: epidemiology and gene mapping. Berardinelli-Seip Study Group.

Five of the six families with the Berardinelli-Seip syndrome in Norway cluster in six adjacent rural municipalities of south-western Norway. The six patients from this area were born between 1951 and 1973, none between 1974 and 1995. The absence of new cases may be explained by a decrease in the intraregion marriage rate and inbreeding. Genealogical investigations show that the mutation must have occurred at least 400 years ago. The sixth family was clinically different and geographically sporadic from a Finnish-descent rural East Norwegian population. A genetic linkage study of all six families revealed fresh crossovers versus the disease allele in nine DNA marker systems and the absence of recombination in three (maximum lod score + 1.3). None of the last showed allelic association. These families are included in an international effort to map the CLBS locus. The patients have been included in the homozygosity testing of totally 28 patients in an international collaborative study. The three patients, assumed identical in descent from both parents, were jointly homozygous in none of the 250 dinucleotide markers tested. A heterochromatic 9qh + segregated from one parent in two families.

Alleles↗
PubMed1989

[Use of modern gene technology in forensic medicine].

Modern DNA technology has had a great impact upon the practice of forensic genetics. Recently developed methods have disclosed different types of genetic variability in human DNA. Typing of genetic DNA polymorphisms based on point mutations represents an alternative to the blood and protein systems developed before. However, the discovery of the so-called hypervariable regions (HVR) in the genome, which represent grossly rearranged areas of DNA, has, revolutionised the field. "Fingerprints", nearly specific for each individual in the population, can be developed by employing specific probes, restriction enzymes and Southern blot technique. We present some results of the application of these techniques in criminal cases investigated at the Institute of Forensic Medicine in Oslo. In future, the sensitivity of the methods may be increased through amplification procedures (PCR reaction).

DNA Probes↗
PubMed1988

Restriction fragment length polymorphisms of the complement component C4 loci on chromosome 6: studies with emphasis on the determination of gene number.

Restriction fragment length polymorphisms of the C4 region of human chromosome 6 have been studied in family material where the haplotypes are defined with regard to other genetic markers in this region. Employing one near full-length C4 probe and the combination of BglII and XbaI enzymes, five different C4 genes were characterized. Studies of the segregation of DNA patterns in families made possible the reliable determination of DNA C4 haplotype pattern including gene number. In the total material of 76 haplotypes, 13 different types with regard to number and/or DNA type of C4 gene(s) were encountered. Twelve of the haplotypes had one C4 gene only, 58 had two genes, while 6 had three C4 genes. This fits fairly well with the hypothesis that the one- and three-gene haplotypes have originated through unequal crossing-over between chromosomes carrying duplicated C4 genes.

Blotting, Southern↗
PubMed1987

The isolation and characterisation of a cDNA clone for human lecithin:cholesterol acyl transferase and its use to analyse the genes in patients with LCAT deficiency and fish eye disease.

We have isolated cDNA clones coding for human lecithin:cholesterol acyl transferase (LCAT) from a liver-specific cDNA library by the use of two oligonucleotide probes based on the protein sequence. The clones span the sequence coding for the entire secreted LCAT, the 3' untranslated sequence and 12 amino acids of the signal peptide. The peptide sequence contains the conserved active site of serine lipases within a hydrophobic domain, flanked by a possible amphipatic alpha-helix. Only one gene for LCAT could be detected in genomic blots. We have used the cDNA as a probe to analyse the LCAT gene in patients suffering from LCAT deficiency and fish eye disease. No rearrangements or abnormal gene fragments were detected in these patients.

Amino Acid Sequence↗
PubMed1987

Identification in blood stains through DNA typing with C4 and HLA-DR probes.

A restriction fragment length polymorphism analysis using double digestion of DNA preparations with XbaI and BglII restriction enzymes and hybridization with C4 and HLA-DR probes is described. The typing conditions selected reveal extensive individual variation in both C4 and DR gene regions. In our panel of 46 unrelated individuals, 37 different phenotypic patterns were recognized when both probes were used, and preliminary discriminative power values of 0.865 and 0.914 were calculated for C4 and DR beta, respectively. The probability of a chance match using both systems is probably about 1.5.10(-2). The potential of this method for individual identification of blood stains was demonstrated on DNA prepared from 6-month-old dried blood stains from seven panel individuals. The seven individuals were all identified when comparing stain DNA patterns with panel control patterns. No RFLP pattern changes were observed following storage of blood stains. Based on these experiments with C4 and DR beta DNA typing under laboratory conditions, it is concluded that DNA typing with such probes may become a powerful tool in future stain identification analyses.

Blood Grouping and Crossmatching↗
PubMed1986

Short-term effects of mating on the accessory sex glands of the male rat.

Mating in the rat was associated with a significant reduction in the tissue concentrations of the presumptive secretory products of the male accessory sex glands: prostatein and the amines, putrescine, spermidine and spermine (ventral prostate lobe), zinc (lateral prostate lobe) and fructose (coagulating gland). The amount of secretory product discharged and the time taken to restore precopulatory levels differed for the different lobes. Within 12-24 h of the mating period, the activity of ornithine decarboxylase and cytosolic oestrogen binding in the ventral prostate lobe underwent a transient increase which lasted 2-3 days. No change was observed in prolactin binding. Circulating testosterone concentrations were significantly elevated above control values 12 h after the start of mating but were significantly lower than control values at 24 h. A gradual recovery to concentrations in controls occurred over the next 2-3 days. None of these changes could be explained by alterations in gonadotrophin or prolactin release.

Androgen-Binding Protein↗
PubMed1985

Genetic polymorphism of complement component C8.

Extensive genetic polymorphism of complement component C8 was demonstrated by isoelectric focusing of serum or plasma samples followed by immunoblotting procedures. Using these methods, we could detect both alpha-gamma (C81) and beta (C82) chain polymorphisms in the same gel. Two-dimensional (2D) electrophoresis of C8 immunoprecipitates was used to obtain further information of the C8 patterns. Evidence was obtained that the C81 polymorphism resides in the structural gene of the C8 alpha chain. Both C8 systems show autosomal, chiefly codominant inheritance, and the distribution of phenotypes agrees with the Hardy-Weinberg equilibrium. Our findings suggest at least five different alleles in the C81 system; the gene frequencies of the two most common ones, C81*A and C81*B being 0.59 and 0.39, respectively. In C82 we found evidence for at least three codominant alleles, the gene frequencies for the two most common ones, C82*B and C82*A being 0.94 and 0.05, respectively. In addition, family studies disclosed the existence of a null allele, C82*Q0.

Alleles↗
PubMed1985

Circadian rhythms in accessory sex gland function in the male rat.

Alterations in various parameters of accessory sex gland function were monitored during two separate 24 h periods in adult male rats, and compared to fluctuations in the circulating levels of testosterone, prolactin, corticosterone and LH. Bimodal circadian rhythms in ventral prostate prolactin binding, cytosolic oestrogen binding and seminal vesicle weight could be discerned which appeared to be related to a similar rhythmicity in circulating testosterone levels, but with a phase shift of 3 h. Prostatic membrane bound adenylyl cyclase activities (basal and hormone stimulated) and prostatein concentrations followed different patterns possibly correlated to other endocrine changes.

Adenylyl Cyclases↗
PubMed1985

Short-term effects of prolactin on prostatic function in rats with lisuride-induced hypoprolactinaemia.

The effects of a single injection of ovine prolactin on prostatic function were monitored in intact, intact androgenized and castrated-androgenized rats rendered hypoprolactinaemic after 7 days of treatment with a potent dopamine agonist, lisuride. Hypoprolactinaemia was associated with reductions in ventral prostate weight, polyamine levels, lateral lobe zinc and the concentration of the ventral prostate protein prostatein, but an elevation in the level of cytosolic oestradiol binding. Whether these differences attained statistical significance depended on whether the animals were intact, intact-androgenized or castrated-androgenized. With the exception of ventral prostate weight and lateral lobe zinc concentrations, a single injection of prolactin restored or reversed these changes towards control levels within 12 h, which could not be explained by an indirect effect of the hormone on adrenal or testicular function. No effects of lisuride or prolactin were observed with regard to the content of fructose in the coagulating gland or in the degree of prolactin binding to prostatic membranes.

Androgen-Binding Protein↗
PubMed1984

The locus for apolipoprotein E (apoE) is close to the Lutheran (Lu) blood group locus on chromosome 19.

Linkage has been described between the loci for apolipoprotein E (apoE) and the complement C3 (C3) on chromosome 19. C3 is known to belong to a linkage group with gene order C3-Se-Lu. The present study revealed linkage between Se and apoE with peak lod score +3.3 at recombination fraction 0.08 in males and +1.36 at 0.22 in females, and linkage between apoE and Lu with lod score +4.52 at zero recombination in sexes combined. The C3-apoE linkage gives lod score +4.00 at theta = 0.18 in males, but +0.04 at theta = 0.45 in females. Triple heterozygote families confirm that apoE is on the Se side and on the Lu side of C3. Allelic association between apoE and Lu has not been ruled out. Combining our data with published data on C3-Se and Se-Lu, this segment of chromosome 19 has an average age sex ratio of female/male recombination of 2.3.

Alleles↗
PubMed1984

The two apolipoprotein loci apo A-I and apo A-IV are closely linked in man.

In man the closely linked genes for the apolipoproteins A-I and C-III have been assigned to chromosome 11. Linkage studies performed in a Norwegian family with a mutant apoA-I gene established a close linkage between the loci for apoA-I and apoA-IV. For both sexes combined, the peak lod score was 3.01 at a recombination fraction of 0 = 0.00. Thus this study adds the locus of apoA-IV to the previously reported apolipoprotein gene cluster on chromosome 11. The previously unidentified polymorphic serum protein, USP1, is by immunochemical and electrophoretical methods identified as apoA-IV. ApoA-IV typing should be a valuable tool in elucidating the genomic organization of chromosome 11.

Apolipoproteins A↗