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Biomedical subjects

R E Gaensslen

Publications and source records attributed to R E Gaensslen.

At least 19 recordsLinked to original sources
PubMed1996

A PCR-based strategy for ABO genotype determination.

The ABO blood group system has been widely used in forensic serology. Several techniques have been developed which detect ABH antigens. To overcome the problems associated with conventional methods such as bacterial contamination, extreme environmental conditions, antigen activity, non-secretor issues, and non-specific absorption, several new strategies have been employed to detect ABO genotypes by PCR. We have developed improved amplimers for the glycosyl transferase locus on chromosome 9 and examined the suitability of PCR-based ABO genotyping for forensic identification. We show that the ABO system is primate specific and that DNA extracted from various tissues commonly encountered in criminal cases can be quickly and reliably typed by ABO-PCR. The results indicate that ABO genotyping by PCR and restriction enzyme digestion of the amplified product is a useful procedure for forensic analysis that can provide additional discriminating power compared to conventional immunological methods.

ABO Blood-Group System↗
PubMed1992

Heat-soaked PCR: an efficient method for DNA amplification with applications to forensic analysis.

Heat-soaked PCR (HS-PCR) is a method for enhancing amplification performed by heating the DNA sample at 94 degrees C in 90 microliters 1.1 x buffer for 30 min. A 10-microliters bolus of concentrated (10x) deoxynucleotides, Taq DNA polymerase and primers prepared without buffer is then added just prior to thermal cycling. We have investigated the application of this method in a variety of forensically important DNA samples and compared it with regular PCR (R-PCR). DNA samples extracted from bone, postmortem tissues, bloodstains and hair contained low concentrations of human DNA or were contaminated with either non- human DNA or hemoglobin degradation products. Optimal conditions for HS-PCR were determined for the 3' ApoB VNTR locus and applied to a centromeric repeat element and to a single-copy locus. HS-PCR consistently and reproducibly enhanced product yield and specificity over R-PCR at all three loci in the entire set of DNA samples. HS-PCR was also effective in overcoming the inhibitory effect of hemoglobin at concentrations that fully impeded R-PCR.

DNA↗
PubMed1992

A polymerase chain reaction (PCR) method for sex and species determination with novel controls for deoxyribonucleic acid (DNA) template length.

Human X and Y chromosome alpha-satellite sequences lying within higher order repeats were amplified by the polymerase chain reaction (PCR) in genomic deoxyribonucleic acid (DNA) isolated from blood, bone, and several other tissues and specimens of potential forensic science interest. X and Y sequences could be coamplified under some of the PCR conditions employed. Monomorphic sequences in the 3'-apolipoprotein B gene (designated "H") and in an alpha-satellite higher order repeat on Chromosome 17 (p17H8, D17Z1) were likewise amplified in the specimens. X and Y sequence amplification can provide information about the sex of origin. Amplification of the X, H, and D17Z1 sequences was found to be primate-specific among the common animals tested and can thus provide species of origin information about a specimen. The authors suggest that amplification of X and D17Z1 or H sequences might provide "relaxed" and "stringent" controls for appropriate PCR amplification tests on forensic science specimens. Testing was carried out using PCR protocols that employed Thermophilus aquaticus (Taq) and Thermus flavis (Replinase) thermostable DNA polymerases.

Animals↗
PubMed1991

Genetic markers in human bone: II. Studies on ABO (and IGH) grouping.

A combination absorption-elution, two-dimensional absorption-inhibition procedure was used to determine the ABH antigen composition of a series of human bone specimens of known ABO type that had been aged up to nine months under dry and humid conditions at ambient temperature, 37 degrees C, and 56 degrees C; at ambient temperature in dry and wet soil; and buried in soil outdoors. Grouping data for the separate elution and inhibition testing, as well as for the combination procedure, are given. The combination method was found to be a highly reliable procedure for bone tissue ABH typing. Some data on microbial contaminants of human bone specimens aging in soil, and their effects on ABH typing results, are presented. No direct correlation between the properties of microbial contaminants and specific changes in the ABH antigenic composition of aging bone tissue specimens could be ascertained. Data on IGH antigen determination and on the quantitation of immunoglobulin G (IgG) in human bone tissue extracts indicated that immunoglobulin levels were typically too low to expect routinely successful Gm antigen testing results. However, these factors can sometimes be determined in fresh bone tissue extracts, particularly if the extracts are concentrated.

ABO Blood-Group System↗
PubMed1990

Distributions of genetic markers in a Nebraska population.

Seven genetic marker systems were analyzed from liquid blood and dried bloodstain specimens submitted to the Nebraska State Patrol Crime Laboratory from various law enforcement agencies throughout Nebraska. The phenotypic and genotypic frequencies for the ABO, Lewis, esterase D (ESD), phosphoglucomutase (PGM), adenylate kinase (AK), adenosine deaminase (ADA), and haptoglobin (HP) systems were calculated. The results indicate that the phenotypic frequencies are generally in agreement with frequencies reported in other populations in the United States.

Blood Group Antigens↗
PubMed1989

ABH antigen typing in bone tissue.

Results obtained from the ABH grouping of bone tissues by the absorption-elution procedure and by a recently described two-dimensional absorption-inhibition procedure are reported. Neither the elution nor the inhibition procedure alone yielded uniformly correct results. A combination procedure consisting of the use of both absorption-elution and two-dimensional absorption-inhibition is proposed for bone ABH grouping. When elution and inhibition were used in combination, specimens yielding concordant results with both techniques were correctly grouped.

ABO Blood-Group System↗
PubMed1988

Two-dimensional absorption-inhibition.

A novel inhibition procedure, called two-dimensional absorption-inhibition, is described. The theory underlying this technique is developed based on a review of and comparison with existing inhibition methods. Two-dimensional inhibition takes advantage of the best features of inhibition-titration and titration-inhibition, and is shown to be more sensitive than either of them. Results obtained using all the inhibition methods on secretor saliva, semen, urine, urine stain, and perspiration stain specimens show that the new technique is especially powerful in correctly determining the ABH antigens in secretor body fluids having lower concentrations of soluble blood group antigens. A two-stage version of the two-dimensional procedure that makes it a practical casework method is described as well.

ABO Blood-Group System↗
PubMed1987

Distributions of genetic markers in United States populations: II. Isoenzyme systems.

All published and unpublished population frequency data that could be located for U.S. populations is tabulated and presented for the isoenzyme systems phosphoglucomutase, esterase D, adenylate kinase, acid phosphatase, glyoxalase I, adenosine deaminase, 6-phosphogluconate dehydrogenase, glutamic-pyruvic transaminase, carbonic anhydrase II, and glucose-6-phosphate dehydrogenase. Results obtained by combining data for comparable racial/ethnic groups are also presented. The results obtained with combined data may give better information on frequencies for the U.S. population at large than is obtainable from studies conducted in restricted geographic areas.

Black People↗
PubMed1987

Distributions of genetic markers in United States populations: I. Blood group and secretor systems.

All published and unpublished population frequency data that could be located for U.S. populations are tabulated and presented for the blood group and secretor systems. Results obtained by combining data for comparable racial/ethnic groups are also presented. The results obtained with combined data may give better information on frequencies for the U.S. population at large than is obtainable from studies conducted in restricted geographic areas.

Blood Group Antigens↗
PubMed1987

Distributions of genetic markers in United States populations: III. Serum group systems and hemoglobin variants.

All published and unpublished population frequency data that could be located for U.S. populations are tabulated and presented for the serum group systems haptoglobin (alpha-chain), group specific component, and transferrin and for the common beta-chain variants of hemoglobin. Results obtained by combining data for comparable racial/ethnic groups are also presented. Some evidence is presented to indicate that the results obtained from the combined data may give better information on frequencies for the U.S. population at large than is obtainable from studies conducted in restricted geographic areas.

Black People↗
PubMed1986

Studies on ABH antigen grouping of ammoniacal extracts of bloodstains by absorption-elution.

The effects of absorption time, titer of antiserum or lectin in the absorption stage, and elution temperature on relative antibody or lectin yield in elutes in the absorption-elution procedure were studied in bloodstains and ammoniacal extracts of bloodstains using conventional grouping reagents. In addition, monoclonal anti-A and anti-B and affinity-purified Ulex europaeus agglutinin I (UEA I) reagents were employed for comparison in these processes. Ammoniacal extracts of bloodstains and dried bloodstains on cotton substrata behaved comparably with respect to the parameters studied. The monoclonal anti-A and anti-B and UEA I reagents studied yielded satisfactory results, comparable in some cases to conventional reagents, with respect to the parameters studied.

ABO Blood-Group System↗
PubMed1985

Enzyme assays for the identification of gastric fluid.

Simple, reliable procedures for the assay of pepsin and rennin-like enzyme activities are described as a means of identifying gastric fluid-containing samples in forensic science laboratories. These samples are usually vomitus, or stomach contents originating from wounds that perforate the stomach. They may be encountered at scenes or on articles submitted for examination, in fresh form or as dried stains. The pepsin activity assay is based on proteolytic activity with bovine albumin as substrate and the rennin-like activity assay is based on the coagulation of milk protein.

Body Fluids↗
PubMed1985

Evaluation of antisera for bloodstain grouping. I. ABH, MN, and Rh.

Sixty-eight different commercially available blood grouping antisera and lectins with ABH, MN, and Rh D, C, E, c, and e specificities were serologically evaluated for their applicability to bloodstain antigen determination. The characteristics of the antisera were determined with red cells, with fresh bloodstains, and with series of aging bloodstains. The Rh antisera were tested under a variety of serological conditions and with bloodstains on various substrata. Additionally, studies on optimization of absorption-elution procedure variables were carried out, and some data on the storage characteristics of red cells and blood grouping antisera were gathered.

ABO Blood-Group System↗
PubMed1985

Evaluation of antisera for bloodstain grouping. II. Ss, Kell, Duffy, Kidd, and Gm/Km.

Thirty-one different examples of commercially available blood grouping antisera specific for the S, s, K, k, Fya, Fyb, Jka, and Jkb antigens and anti-human globulin sera were serologically evaluated with red cells and in absorption-elution tests to determine their applicability to bloodstain antigen determinations. Nineteen examples of commercially available antisera specific for various Gm and Km antigens and their corresponding anti-D reagents were likewise evaluated in inhibition tests with sera and bloodstains. Elution tests with the blood grouping antisera and inhibition tests with the Gm/Km antisera on a series of aging bloodstains on cotton cloth, and on bloodstains on a number of different substrata, demonstrated that properly evaluated commercial antisera are useful reagents for bloodstain grouping in forensic serology.

Antibody Specificity↗
PubMed1984

Evaluation of monoclonal anti-A and anti-B and affinity-purified Ulex europaeus lectin I for forensic blood grouping.

Two different monoclonal anti-A and anti-B and several different affinity purified Ulex europaeus lectin I reagents were evaluated and compared with conventional anti-A and anti-B sera and Ulex anti-H for serologic properties, in inhibition tests with secretor salivas, and in elution tests with bloodstains. The monoclonal and purified reagents were found to be comparable to conventional ones, and accordingly suitable for forensic inhibition and elution procedures.

ABO Blood-Group System↗
PubMed1975

Phenotypic distributions of red cell glutamate-pyruvate transaminase (E.C.2.6.1.2) isoenzymes in British and New York populations.

1444 persons of British nationality living in London, and 294 Caucasians, 258 Negroes, 310 Hispanic persons, and 151 Chinese persons living in New York were tested for glutamate-pyruvate transaminase phenotype. The Gpt1 frequency in the British population was found to be 0.5277, the Gpt2 frequency was 0.4716, and two GPT 3-2 persons were found. The Gpt1 frequencies in the New York population were: 0.4834 in Chinese; 0.5226 in Hispanic persons; 0.8101 in Negroes; and 0.5306 in Caucasians. Two Caucasians possessed the GPT 3-2 phenotype.

Alanine Transaminase↗