PubMed Health⌕ Search

Biomedical subjects

M Lukka

Publications and source records attributed to M Lukka.

35 records · Page 2Linked to original sources

PCR amplification of alleles at the DIS80 locus: comparison of a Finnish and a North American Caucasian population sample, and forensic casework evaluation.

Allele and genotype frequencies for the highly polymorphic D1S80 locus were determined in a Finnish population sample by using PCR followed by high-resolution PAGE and silver staining, a procedure called the amplified-fragment-length polymorphism (Amp-FLP) technique. In 140 unrelated Finnish individuals 15 alleles and 43 phenotypes were observed. The D1S80 locus demonstrated a heterozygosity of .77, and the power of discrimination was .92 in this sample representing a genetically isolated Finnish population. The distribution of observed genotypes conformed to Hardy-Weinberg expectations. In 36 mother-child pairs Mendelian inheritance for the alleles at the D1S80 locus could be demonstrated in all cases, and no mutations were observed. The usefulness of the D1S80 locus for forensic casework was assessed by using Amp-FLP analysis of the D1S80 locus in 36 forensic cases including 18 rapes, 14 homicides, and 4 other violent crimes. In most cases valuable information was obtained using the Amp-FLP technique, and in no case was there indication of either false-positive or false-negative results.

Alleles↗

A previously reported polymorphic plasma protein of dogs and horses, identified as apolipoprotein A-IV.

By using immunoblotting with antiserum specific to human plasma apolipoprotein A-IV (apoA-IV), a previously reported polymorphic plasma protein of dogs viz postalbumin-2 (Pa2) and one of horses viz serum protein 2 (SP2), were identified as apoA-IV of these species. This along with earlier published results implied that: (1) both dog and horse show a high degree of polymorphism at the APOA4 locus with three common alleles in each of the two species; and (2) apoA-IV phenotyping in these two species can be done by analysing plasma/serum samples by a simple method of two-dimensional electrophoresis, conducted under non-denaturing conditions, followed by general-protein staining of gels.

Animals↗

Plasma alpha 1B-glycoprotein allele frequencies in Finns and Swedish Lapps: evidence for a new alpha 1B allele.

A new allele (A1B*5) of human plasma alpha 1B-glycoprotein (alpha 1B) was reported. alpha 1B phenotyping was done by two-dimensional agarose gel (pH 5.4)-horizontal polyacrylamide gel (pH 9.0) electrophoresis followed by protein staining. The alpha 1B phenotypes 1-1, 1-2, 1-5 and 2-2 were observed in Finns and phenotypes 1-1, 1-2, 1-5 and 2-5 in Swedish Lapps. The respective frequencies of A1B*1, A1B*2 and A1B*5 were 0.9575, 0.0350, 0.0075 in Finns and 0.8922, 0.0653, 0.0425 in Swedish Lapps. The Swedish Lapps showed a higher degree of alpha 1B polymorphism (polymorphism information content = 0.19) than other Caucasian populations that have been studied.

Alleles↗

Transferrin C subtype frequencies in the Finnish population.

Transferrin (Tf) C subtypes were determined in 419 unrelated adult Finns. The calculated gene frequencies were C1 = 0.738, C2 = 0.097 and C3 = 0.133. The Tf phenotypes in 150 mother-child pairs were in accordance with autosomal codominant inheritance. This material included a rare TfC allele product in three individuals, apparently the same in all cases.

Adult↗

Apolipoprotein A-I-binding protein from human term placenta. Purification and partial characterization.

A protein that binds to the main apoprotein, apoA-I, of human high density lipoprotein (HDL) has been isolated from human placenta. Ligand blotting after SDS gel electrophoresis indicated that the 120 kDa protein in the absence of reducing agents binds apoA-I. If gel electrophoresis was performed under reducing conditions two main bands, approx. 50 and 30 kDa that did not bind apoA-I, were evident. In an enzyme-linked immunosorbent assay the binding protein specifically bound apoA-I, delipidated or as HDL. ApoA-II, apo E and LDL did not compete with apoA-I for binding to this protein.

Apolipoprotein A-I↗

Apolipoprotein E polymorphism, serum lipids and occurrence of "double pre-betalipoproteinemia' (DPBL) in subjects from two different populations.

The association between apolipoprotein E phenotype and the presence of 2 electrophoretic populations of very low density (VLDL) lipoproteins from human sera, double pre-beta(VLDL)lipoproteinemia (DPBL), was studied in 2 groups of subjects, one from Italy and one from Finland. In both populations the prevalence of DPBL was significantly higher in subjects with E4/4 and E4/3 phenotypes than in the other phenotypes not containing the E4 isoprotein. This finding suggests that the presence of a structural variant of the apo E protein, the isoprotein E4, may be causally related to the appearance of DPBL phenomenon.

Adolescent↗

Acid phosphatases bind to the main high density lipoprotein apolipoprotein A-I.

The serum protein binding secretory prostatic acid phosphatase (PAP) and lysosomal placental acid phosphatase (LAP) was purified using affinity chromatography on gels containing immobilized acid phosphatases. The protein, which could be eluted from these enzyme affinity gels only with 0.05 mol/l HCl (pH 2.0), was shown to be apolipoprotein A-I (apo A-I), the main structural protein of high density lipoprotein (HDL).

Acid Phosphatase↗

Group-specific component (Gc): subtypes in the Finnish population. Description of a new allele and an apparent mother-child incompatibility.

The group-specific component (Gc) subtypes were determined in 575 adult Finns by immunoblotting after isoelectric focusing in agarose gel. The gene frequencies were Gc1S = 0.661, Gc1F = 0.139 and Gc2 = 0.200. This material included one rare allele, a more acidically focusing Gc 2 (named Gc 2A18). The phenotypes of 200 mother-child pairs studied were in accordance with the three-allelic mode of inheritance. An apparent mother-child incompatibility observed during routine paternity testing is reported.

Alleles↗

Monoclonal antibodies specific for different regions of human apolipoprotein A-I. Characterization of an antibody that does not bind to a genetic variant of apoA-I (Glu----136 Lys).

Three monoclonal mouse hybridoma antibodies, designated 2AI, 4AI, and 5AI, specific for human plasma apolipoprotein A-I (apoA-I) were characterized. In an enzyme-linked immunosorbent assay (ELISA) each of the antibodies reacted with purified apoA-I and with A-I in normal human serum. Immunoblotting of apoA-I subjected to isoelectric focusing revealed that the three antibodies reacted with all the charge isomorphs of apoA-I and with proapoA-I. Using a solid phase competitive displacement assay, the antigenic determinant for antibody 5AI could be localized to cyanogen bromide fragment 3 of apoA-I (residues 113-148), while the epitope for antibody 4AI resided in cyanogen bromide fragment 4. Dot blot experiments and data obtained by the competitive displacement assay revealed that antibody 2AI reacts with high affinity with CNBr fragment 2 but that it also reacts with lower affinity with fragments 1 and 4. The antibody 5AI did not bind to a genetic variant of apoA-I (Glu----136 Lys), demonstrating that the substitution of a single amino acid in human apoA-I can cause the loss of an antigenic determinant.

Animals↗

Apolipoprotein E polymorphism in the Finnish population: gene frequencies and relation to lipoprotein concentrations.

ApoE phenotypes were determined in 615 unrelated Finnish individuals. The apoE gene frequencies observed (epsilon 2, 0.041; epsilon 3, 0.733; epsilon 4, 0.227) differ significantly from those in other populations. The frequency of the allele epsilon 2 was lower and that of epsilon 4 higher than in all other studied populations. Plasma lipids and apolipoproteins A-I, A-II and B were recorded in 207 of the typed subjects. By comparison with the most frequent homozygous apoE 3/3 phenotype, it was found that total cholesterol, LDL-cholesterol, and apoB concentrations were all markedly higher in apoE 4/4 and to a lesser degree in apoE 4/3 phenotypic groups. On the other hand, these lipid and apolipoprotein levels tended to be lower in E-2 heterozygotes. These data confirm and extend, in a different ethnic group, previous results of an effect of apoE genes on plasma lipoprotein concentrations. The data suggest that the apoE gene locus may be one factor responsible for the high LDL cholesterol concentrations in the Finnish population.

Alleles↗

Serum amyloid A protein (SAA) subtypes in acute and chronic inflammatory conditions.

Serum amyloid A (SAA), a polymorphic high density lipoprotein associated plasma protein, is the putative circulating precursor of tissue AA protein fibrils in reactive (secondary) amyloidosis. In the present study we examined the SAA subtype pattern in various acute and chronic inflammatory states in order to find out whether disease-specific SAA isoform profiles exist. The method used to study the subtype pattern is based on electrofocusing of serum followed by immunoblotting. Our results show that the SAA subtype pattern is similar in patients with rheumatoid arthritis with or without amyloid. In addition, in amyloidotic subjects the SAA subtype response to acute tissue injury (arthroplasty) did not differ from that in patients without amyloidosis. Analysis of patients with acute and chronic infectious diseases and non-rheumatic inflammatory conditions showed similar SAA patterns in all subjects. These results suggest that the SAA subtype response to tissue injury and inflammation is similar irrespective of the initiating stimulus.

Acute Disease↗

Phosphoglucomutase (PGM1) subtypes in a Finnish population determined by isoelectric focusing in agarose gel.

The red cell enzyme phosphoglucomutase first locus (PGM1) phenotypes of 639 adult Finns were determined by isoelectric focusing in agarose gel. All the ten commonly occurring phenotypes were detected and the frequencies of the four alleles at the PGM1 locus were as follows: PGMa11 = 0.5313, PGMa21 = 0.1800, PGMa31 = 0.2199 and PGMa41 = 0.0689. The PGM1 phenotypes of 221 mothers with 228 offspring were in accordance with autosomal codominant inheritance.

Alleles↗

A silent transferrin allele in a Finnish family.

In a Finnish family a silent allele was found in the transferrin (Tf) system. As determined by gel electrophoresis and immunoblotting, the Tf type of the father was CD, the mother C, and the child D. The serum Tf concentration in grandmother, mother, and child was less than 50% of normal.

Adult↗

Vitamin E does not influence plasma lipoprotein metabolism in healthy subjects with normal nutritional status.

The effect of a 6-week treatment with large doses (600 IU/day) of vitamin E on plasma lipoprotein metabolism has been studied in six healthy middle-aged subjects. No consistent change was observed during the treatment in the plasma concentrations of cholesterol, triglycerides, high density lipoprotein (HDL) cholesterol or apolipoproteins AI, AII and B or in the activity of postheparin plasma lipoprotein lipase or hepatic lipase. It is concluded that vitamin E does not influence plasma lipoprotein metabolism in healthy subjects with normal nutritional status.

Adult↗

Experimentally observed germline mutations at human micro- and minisatellite loci.

We have analysed close to 30,000 human germline transmission events at five microsatellite loci (D3S1359, HumTH01, HumvWA, HumTPO and HumFES) and four minisatellite loci (D1S80, ApoB, Col2A1 and D17S30). At these loci the mutation rates are similar at the microsatellite and the minisatellite loci, varying from 0.2 x 10(-3) to < 3.3 x 10(-3) and from 0.5 x 10(-3) to 1.5 x 10(-3), respectively. Interestingly, paternal mutations appeared to be dominant at the microsatellite loci, whilst maternal mutations are dominant at minisatellite loci. Based on our data, no unequivocal support for a strict strand-slippage mutation mechanism (gain or loss of a single repeat) was found, although the vast majority of the mutational events were small gains or losses of one to three repeats, and only few unequivocal large gains or losses were observed.

Alleles↗

The mutation causing the common apolipoprotein A-IV polymorphism is a glutamine to histidine substitution of amino acid 360.

Apolipoprotein (apo) A-IV is a protein involved in the metabolism of chylomicrons and high density lipoproteins. This protein displays genetic polymorphism due to two main codominant alleles, A-IV1 and A-IV2. We have identified the mutation that leads to this polymorphism. It is caused by a single-base substitution of guanine for thymine in the third base of codon 360. This substitution leads to a glutamine to histidine change. Direct sequencing of amplified DNA from eight subjects in a three-generation pedigree has demonstrated that the guanine to thymine substitution can explain the apo A-IV polymorphism. In 32 unrelated individuals, a correspondence between apo A-IV phenotype determined by isoelectric focusing and genotype determined with Fnu4HI digestion of amplified DNA could be demonstrated. The enzyme lecithin:cholesteryl acyltransferase (LCAT) is activated by apo A-IV. Under our in vitro conditions, the isoprotein apo A-IV 1-1 is a better LCAT activator than is the isoprotein apo A-IV 2-2. A knowledge of the molecular mechanism underlying the apo A-IV polymorphism will help to elucidate the mechanisms involved in LCAT activation.

Amino Acid Sequence↗