Biomedical subjects
Publications and source records attributed to B Budowle.
Isoelectric focusing of extracts from diluted or aged bloodstains may be more successfully accomplished with larger sample volumes applied to the gel. A technique is described using teflon tubing to apply larger sample volumes (up to 100 microliters) to isoelectric focusing (IEF) gels. This method is reproducible and easy to perform.
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C4 is composed of two tightly linked genes (C4A and C4B) lying within the major histocompatibility complex of chromosome 6 that can be demonstrated by agarose gel electrophoresis. Seven alleles and five alleles at the C4A and C4B loci, respectively, were detected in 169 black individuals from the southeastern United States. Furthermore, the phenotypic frequencies of C4A6, C4A5, C4A4, C4B4, C4B3 and C4BQ0 were significantly different between black and white Americans.
One hundred-sixty-four ALL patients were compared to 545 controls for differences in phenotype and gene frequencies at the Properdin factor B locus. In addition, 90 of the ALL patients were immune phenotyped. A significant association with the Bf F allele and ALL was found, resulting in an estimated relative risk of 3.62. There was no difference in the Bf S phenotype between ALL patients and controls. However, those homozygous for the Bf S allele are at a significantly low risk of 0.30 for developing ALL. ALL patients with a non-B/T cell type were 2.5 times more likely to be Bf SS homozygotes; in contrast, those patients with the pre-B cell type were 2.5 more likely to be Bf FF homozygotes. These data suggest association of the Bf locus with an ALL protection and/or susceptibility gene(s).
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We investigated 98 melanoma patients and 135 normal controls for differences in phenotype and genotype frequencies at the properdin factor B locus. A significant negative association with the Bf-F allele and melanoma was found, resulting in an estimated relative risk of 0.5. The estimated relative risk for developing melanoma among people with the Bf-FF genotype is 0.07. The Bf-S phenotype was significantly increased among the melanoma sample, with an estimated risk of 6.5. The data suggest association of the Bf locus with a melanoma protection and/or susceptibility gene(s).
In recent years, it has been proposed that genetic admixture may have played a role in the increased frequency of insulin-dependent diabetes mellitus (IDDM) in young U.S. blacks relative to African blacks. In support of this proposal, the similar associations of specific markers of the major histocompatibility complex (MHC) with IDDM in U.S. blacks with respect to U.S. whites have been cited. To determine whether racial admixture was a factor in the increased prevalence, we did three analyses of admixture. In the first we used nine genetic markers (ABO, Rh, Fy, Hp, Gc, Pl, OR, Tfr, and Gm) and determined that there was significantly greater than zero genetic contribution from whites in our sample of U.S. black IDDM patients (9.6 +/- 2.3%, P less than 0.01) when a sample of U.S. blacks without IDDM was used as one "parental" population. In the next two analyses, we estimated the amounts of genetic contribution from whites in the U.S. blacks with and without IDDM using reported gene frequencies for West African blacks for four genetic markers (ABO, Rh, Fy, and Hp). The estimate of admixture (21.4 +/- 2.8%) for the black IDDM sample was greater than that for the U.S. black controls (17.9 +/- 2.3%), although the difference was not significant. Our estimate of genetic contribution from whites, 21.4% for black IDDM patients, supports the assumptions of 20% admixture which MacDonald and Rotter and Hodge used to test their respective models for the inheritance of IDDM. These results support the hypothesis that admixture with the white population is, in part, responsible for the increase in prevalence of IDDM seen in U.S. blacks.
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Properdin factor B is a genetically-controlled polymorphism that can be demonstrated by agarose gel electrophoresis. The Bf gene frequencies were determined for 194 blacks from the south-eastern United States. The frequencies for Bf-F, Bf-S, Bf-F1, and Bf-S1 are 0.626, 0.034, and 0.013, respectively. The south-eastern blacks have similar Bf frequencies to the South African blacks; however, both these groups are different from blacks from Boston. The frequency differences between south-eastern blacks and Boston blacks may be due to racial admixture differences found in the two populations.
Blood specimens from white and black sample populations from Baltimore, Maryland, were analyzed for the four most forensically important, polymorphic red cell enzyme systems-phosphoglucomutase-1, esterase D, erythrocyte acid phosphatase and glyoxalase I. The distributions of the phenotypes for each marker in each racial group were in Hardy-Weinberg equilibrium. The population data were similar to previously reported data for Whites and Blacks from different geographical locations within the United States.
Analytical methods were developed to determine the presence of ethylenediaminetetraacetic acid (EDTA) in dried bloodstains to provide probative information when allegations of evidence tampering have been made in criminal cases. A simple screening method using ion chromatography to analyze stains was found to be quantitative to the 5 ppm level. The presence of EDTA was then confirmed using negative and positive ion mode liquid chromatography-tandem mass spectrometry (LC-MS-MS) methods. A blind trial of these methods on 42 samples correctly determined the bloodstains that did and did not contain the preservative EDTA. One interesting observation in these results was the adsorption and postanalysis release of EDTA in the chromatographic system. In order to avoid cross contamination of samples resulting from this phenomena, it was found to be necessary to use EDTA-free blood extracts as blanks in the LC-MS analysis of bloodstains.
Allele and genotype frequencies for six polymerase chain reaction (PCR)-based DNA genetic markers were determined in a Chinese sample population. The loci are HLA-DQ alpha, low-density-lipoprotein receptor, glycophorin A, hemoglobin gamma G, D7S8, and group-specific component. These results were obtained using the AmpliType HLA-DQ alpha forensic DNA amplification and typing kit and the AmpliType PM PCR amplification and typing kit. All loci met Hardy-Weinberg expectations and there was no evidence for association of alleles between the loci. The frequency data can be used in forensic analyses and paternity tests to estimate the frequency of a DNA profile in the Chinese population.
Allele distributions were determined for several VNTR loci in the general French Caucasian population, a French regional population from Brittany and in three French Canadian populations, residing either in Montréal or in one of two other regions in Québec. Allele distributions are highly polymorphic in all populations sampled. Despite a well-documented genetic founder effect in one of the populations, no disequilibrium was detected over all genotypes, within and between loci, for the data bases in this study. Moreover, there were no forensically significant differences observed between estimated frequencies of 1,964 Caucasian and non-Caucasian target DNA profiles estimated in any of the groups.
Separation of polymerase chain reaction (PCR) amplification of specific fragment length polymorphisms was carried out on rehydratable polyacrylamide gels on a horizontal flat slab system. A discontinuous sulfate-borate buffer system was employed on 5-8% T gels crosslinked with 3.5% C. Samples were diluted in leading sulfate ion buffer at 1/10 the ionic strength of the separating gel buffer and placed directly onto the surface of the rehydrated gels in 0.5-10 microliters volumes. The trailing ion and counterion were contained in a gel plug and placed directly onto the anodal and cathodal ends of the gel, and the electrodes placed directly onto the surface of the gel plugs. Filter paper wicks, soaked in diluted leading ion buffer, were placed along each side to lower the ionic strength of the edges, thereby increasing mobility at the edge and thus preventing smile effects. The gel-gel contact of the plug and separating gel prevent the production of a junction potential which occurs between dissimilar materials such as a paper wick and the gel. Ten- to 20-cm separations were carried out from 2-5 h, respectively, and resolution in the 20 cm system was 1.6-4 bp (base pairs) between 100 and 500 bp, 4-7 bp between 500 and 1000 bp, 12-20 bp between 1000 and 2000 bp and about 50 bp between 2000 and 3000 bp. Between 3000 and 4000 bp, resolution fell off to +/- 100 bp. Sensitivity, using a silver stain, indicated that one could readily distinguish less than 10 pg of DNA per mm width on the gels.(ABSTRACT TRUNCATED AT 250 WORDS)