PubMed Health⌕ Search

Biomedical subjects

B Mevåg

Publications and source records attributed to B Mevåg.

12 recordsLinked to original sources
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↗
PubMedDate not supplied

Report of a European collaborative exercise comparing DNA typing results using a single locus VNTR probe.

A collaborative exercise was carried out in 1989 among 12 European forensic laboratories using the single locus VNTR probe pYNH24, the restriction enzyme HinfI, the same set of human genomic DNA samples, and a standardized DNA size marker. The objectives of the exercise were: (1) to study the degree of variation within and between laboratories, (2) to obtain information on requirements for technical standardization allowing the exchange of typing results and (3) to compare different approaches for the identification of allelic DNA fragments of unknown size. Each laboratory carried out up to 10 independent typing experiments using the same DNA samples. The results were analysed independently by two laboratories using three different methods. The results of the exercise demonstrate the correlation of typing that can be achieved within and between laboratories under conditions of minimal standardization.

Alleles↗