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Biomedical subjects

B Boettcher

Publications and source records attributed to B Boettcher.

At least 19 recordsLinked to original sources
PubMed1992

Development of human ABO blood group A antigen on Escherichia coli Y1089 and Y1090.

Studies by other workers have shown that some strains of Escherichia coli have surface antigens analogous to the human blood group ABH antigens, and that these are carbohydrates associated with membrane lipopolysaccharides. This study has demonstrated that E. coli strains Y1089 and Y1090 possess the H antigen, which can be converted to the A antigen by incubation with A-transferase (N-acetyl-galactosaminyl transferase) and A-sugar (UDP-N-acetyl-galactosamine). Such cells will then form mixed agglutinates with human A red cells and human polyclonal (but not mouse monoclonal) anti-A antibodies. E. coli Y1089 and Y1090 have endogenous enzymes that use the A-sugar (in the absence of A-transferase) to produce a variant A antigen. Cells expressing this variant antigen adsorb anti-A antibodies but do not participate in mixed agglutination with human group A red cells. It is estimated that E. coli Y1089 and Y1090 possess approximately 5000 H epitopes per cell that can be converted to A epitopes.

ABO Blood-Group System↗
PubMed1992

Comparison of the SpermMar test with currently accepted procedures for detecting human sperm antibodies.

To eliminate the possibility of immunological infertility in spontaneously infertile and re-anastomosed men, a screening test that can be applied directly to semen is desirable. The SpermMar test is one such possibility. In this study, indirect tests for sperm antibodies using the commercial SpermMar test have been applied to a panel of sera whose reactions in the tube slide agglutination test (TSAT), gelatin agglutination test (GAT) and sperm immobilization test (SIT) for sperm antibodies are well characterized. The results from the SpermMar tests are compared directly with those obtained from Immunobead tests carried out at the same time. Results from screening tests performed on 30 sera confirmed complete correspondence between the GAT, SpermMar and Immunobead tests. When sera were titrated, the Immunobead test proved slightly more sensitive than the GAT and the SpermMar test was slightly more sensitive than the Immunobead test. The SpermMar test proved easier to use and to assess than the Immunobead test and it is recommended for consideration as a screening procedure for sperm antibodies despite the fact that at this stage only IgG antibodies can be detected.

Autoantibodies↗
PubMed1992

A difference in the proteins found in young adults of inbred strains of Drosophila melanogaster which correlates with genetically-determined, long or short life span.

One-dimensional electrophoresis was performed on extracts of flies collected from across all ages. Protein gel patterns were compared for two strains of Drosophila melanogaster with distinctly long and short adult life spans that result from different alleles of longevity genes. An inter-strain difference was observed in the changes in protein pattern in the 77 kDa region in period of day 0-5 after emerging. We propose that the protein involved is a product of autosomal longevity alleles A1 and A2 at the Jm A locus and is related to development of longevity potentials in the preimaginal stage.

Animals↗
PubMed1992

Purification and characterization of a protein associated with genetically-determined longevity difference in Drosophila melanogaster.

Earlier studies have shown a correlation between the presence of a 77 kDa protein in the proteins extracted from young adult Drosophila melanogaster (D.m.) and the autosomal longevity allele. A2 at the JmA locus. In this study, a 77 kDa protein has been isolated from pupae of D.m. of a long-lived strain of genotype A2A2, and was purified by DEAE chromatography, ConA column chromatography, and two cycles of gel filtration. The purified protein has a molecular weight of 76,600 (by SDS-PAGE), an isoelectric point of pH 6.5, and molar extinction coefficient A(280(1%) = 18.3. It is a glycoprotein containing 3.3% hexose. Supplementing the food of D.m. with the purified protein at 5 x 10(-4) micrograms/ml, beginning at day 5 after emergence, resulted in an increase in the survival rate and maximal life span of both short-lived and long-lived strains of D.m.

Animals↗
PubMed1979

Mixed-lymphocyte culture response in a related and an unrelated Australian population.

In 256 related combinations in an Australian Caucasian population, the relative responses in one-way mixed-lymphocyte cultures can be divided into four different groups: (i) HLA zero-haplotype different; (ii) HLA-D homozygous-versus-heterozygous; (iii) HLA one-haplotype different: and (iv) HLA two-haplotype different. The median relative responses of the groups were 0.78%, 20%, 64% and 86.5%, respectively; 17.7% of HLA-A, HLA-B identical siblings were found to stimulate significantly in mixed-lymphocyte culture, and 6.3% of HLA one-haplotype different combinations had weak responses. The median relative response of 225 unrelated random combinations was 100%. One mixed-lymphocyte culture combination in this group gave a relative response of 20%, which was found to be a HLA-D homozygous-versus-heterozygous response. A relative response of 20% in mixed-lymphocyte cultures may be taken to indicate relative HLA-D compatibility and would, therefore, predict a favourable outcome in kidney transplantation. The use of mixed-lymphocyte cultures as a routine in selecting suitable donors in living related transplants and, retrospectively, in monitoring the results of cadaveric transplants, is advocated.

Graft Survival↗
PubMed1979

The presence of complement in human cervical mucus and its possible relevance to infertility in women with complement-dependent sperm-immobilizing antibodies.

Full-complement component lytic activity was measured in human midcycle cervical mucus, using a sensitive 51Cr release hemolytic assay. The level measured was 11.5% of the activity of complement in an equal volume of undiluted human serum. The relevance of this level of complement to complement-dependent sperm-immobilizing antibody activity was studied. After 1 hour's incubation with mucus levels of complement, immobilization of about 50% of spermatozoa occurred and after 3 hours' incubation, immobilization of about 70% of spermatozoa occurred.

Antibodies↗
PubMed1979

The effect of steroids on the in vitro migration of washed human spermatozoa in modified Tyrode's solution or in fasting human blood serum.

In modified Tyrode's solution, 17 beta-estradiol at concentrations between 0.1 microgram/ml and 320 nmoles/ml was effective in increasing human spermatozoal forward migration. 17 alpha-Estradiol, although structurally similar to 17 beta-estradiol, had no effect on human spermatozoal motility. DL-Norgestrel at concentrations between 0.1 migrogram/ml and 320 nmoles/ml inhibited spermatozoal motility. These stimulatory and inhibitory effects were not observed when fasting human blood serum was used as a penetration medium in place of the modified Tyrode's solution. Also, the motility of spermatozoa suspended in fasting human blood serum was better than that of spermatozoa suspended in modified Tyrode's solution or in seminal plasma. These observations indicated that there is a component(s) of fasting human blood serum which increases spermatozoal motility and can counteract the activation or inhibition of spermatozoal motility by 17 beta-estradiol or DL-norgestrel at the concentrations used here.

Blood↗
PubMed1978

Isolation of human lactate dehydrogenase isoenzyme X by affinity chromatography.

Human isoenzyme LDH-X (lactate dehydrogenase isoenzyme X) was isolated from seminal fluid of frozen semen samples by affinity chromatography by using oxamate-Sepharose and AMP-Sepharose. In the presence of 1.6 mM-NAD+, isoenzyme LDH-X does not bind to AMP-Sepharose, whereas the other lactate dehydrogenase isoenzymes do. This is the crucial point in the isolation of isoenzyme LDH-X from the other isoenzymes. The purified human isoenzyme LDH-X had a specific activity of 146 units/mg of protein.

Adenosine Monophosphate↗
PubMed1978

Binding of steroids to human spermatozoa and its possible role in contraception.

The binding of steroids to human ejaculated spermatozoa and the effect of steroids bound to spermatozoa on sperm migration and motility in vitro was examined. A correlation between progestogens that bind to steroid-binding sites on human spermatozoa and progestogens that inhibit sperm migration was established. The results indicated that there is a direct and specific steroid effect on human spermatozoa, as some steroids such as progesterone, lynestrenol, and norethynodrel markedly inhibited sperm migration and motility, whereas other steroids such as estrone had no detectable effect on sperm migration and motility. The significance of these findings was discussed in relation to the contraceptive action of steroids applied directly to the lumen of the female genital tract.

Contraceptive Agents↗
PubMed1978

Studies on blood from the original Rhnull proposita and relatives.

A relative of the original Rh proposita, of group R1R2, shows weak expression of his Rh antigens, and is thought to be an Rhnull heterozygote. His wife and 3 of their 4 children show normal Rh antigen expression, but one daughter showed weak Rh antigen expression, as determined by quantitative haemagglutination. The observations support the proposition that the father is heterozygous for an unlinked modifier of Rh antigen expression. Stomatocytosis, observed in the Rhnull proposita and other Rhnull individuals, was also observed, but to a lesser degree, in the blood of an other individual thought to be an Rhnull heterozygote. This observation also supports the earlier conclusion that the Rhnull phenotype of the proposita is due to homozygosity for inactive alleles at a locus which controls the biosynthesis of precursor for Rh and LW antigens. Osmotic fragility tests showed that the Rhnull cells were more fragile than cells with normal Rh antigen expression, and cells from Rhnull heterozygotes had intermediate fragility. This is consistent with the proposition that Rh antigens are normal structural components of the red cell membrane, and the Rhnull heterozygotes show a deficiency of the Rh antigenic structures.

Erythrocytes, Abnormal↗
PubMed1978

Sequence of action of genes at the secretor, H, ABO and Lewis loci.

It is argued that Lewis genes are responsible for adding specificity to glycoprotein molecules after the activities of the secretor, H and ABO genes, respectively, have been expressed. This conclusion is based on the results of studies on the expression of ABO and Lewis antigens in salivas from Australian aborigines, and on biochemical results. A simple figure illustrating the antigens determined on red cells and in body secretions as a result of the action of these genes, in their correct order--secretor, H, ABO, Lewis--is presented.

ABO Blood-Group System↗
PubMed1978

The metabolism and motility of human spermatozoa in the presence of steroid hormones and synthetic progestagens.

The metabolism and motility of human ejaculated spermatozoa incubated in vitro with steroids were studied. Progesterone and norethynodrel depressed the respiration, glycolytic metabolism and the motility of washed spermatozoa. Lynoestrenol did not affect the respiration or glycolysis of the spermatozoa, but did inhibit motility. Oestradiol did not cause any consistent alteration of the sperm metabolism, and did not affect the motility. Progesterone and norethynodrel appeared to act on the plasma membrane of human spermatozoa to increase its permeability and hence to facilitate the loss of essential cofactors required for the glycolytic and oxidative processes.

Energy Metabolism↗