Biomedical subjects

J Kömpf

Publications and source records attributed to J Kömpf.

At least 19 recordsLinked to original sources

PubMed2000

Localization of S-adenosylhomocysteine hydrolase in the rat kidney.

S-adenosylhomocysteine (SAH) hydrolase is a cytosolic enzyme present in the kidney. Enzyme activities of SAH hydrolase were measured in the kidney in isolated glomeruli and tubules. SAH hydrolase activity was 0.62 +/- 0.02 mU/mg in the kidney, 0.32 +/- 0.03 mU/mg in the glomeruli, and 0.50 +/- 0.02 mU/mg in isolated tubules. Using immunohistochemical methods, we describe the localization of the enzyme SAH hydrolase in rat kidney with a highly specific antibody raised in rabbits against purified SAH hydrolase from bovine kidney. This antibody crossreacts to almost the same extent with the SAH hydrolase from different species such as rat, pig, and human. Using light microscopy, SAH hydrolase was visualized by the biotin-streptavidin-alkaline phosphatase immunohistochemical procedure. SAH hydrolase immunostaining was observed in glomeruli and in the epithelium of the proximal and distal tubules. The collecting ducts of the cortex and medulla were homogeneously stained. By using double immunofluorescence staining and two-channel immunofluorescence confocal laser scanning microscopy, we differentiated the glomerular cells (endothelium, mesangium, podocytes) and found intensive staining of podocytes. Our results show that the enzyme SAH hydrolase is found ubiquitously in the rat kidney. The prominent staining of SAH hydrolase in the podocytes may reflect high rates of transmethylation. (J Histochem Cytochem 48:211-218, 2000)

Adenosylhomocysteinase↗

PubMed1999

Adenosine deaminase polymorphisms at the protein and DNA levels.

Adenosine deaminase (ADA, E.C. 3.5.4.4) exhibits a well-known polymorphism at the protein level. We have studied ADA and an STR polymorphism exhibiting variation of a TTTA repeat motif at intron 3 of the ADA gene in random samples from northern Portugal (N = 218) and southwestern Germany (N = 114). The ADA phenotype distribution and population data on the worldwide distribution of ADA favor recurrent mutation as an explanation for the maintenance of the ADA*2 gene product at polymorphic frequencies.

Adenosine Deaminase↗

PubMed1997

Rapid engraftment after allogeneic ABO-incompatible peripheral blood progenitor cell transplantation complicated by severe hemolysis.

A patient with CML in accelerated phase received G-CSF-mobilized PBPC from an unrelated HLA genotypically matched donor. The blood groups of the patient and donor were bidirectionally incompatible. Hematologic recovery was rapid with > 500 PMN/microliter on day +9. Starting on day +5 bilirubin levels increased from 1.3 mg/dl up to a maximum of 18 mg/dl on day +14. Clinical signs and laboratory tests supported major hemolysis. Blood typing on day +16 revealed early blood-group change, consistent with donor-derived antibodies produced by passenger-lymphocytes which may have mediated severe hemolysis. The early onset and strong intensity of the hyperbilirubinemia could be a specific feature of ABO-incompatible allogeneic PBPC transplantation which would be difficult to differentiate from GVHD or VOD.

ABO Blood-Group System↗

PubMed1995

Transient bisalbuminemia: separation by isoelectric focusing of human albumin fractions linked to different numbers of benzylpenicilloyl groups.

The behavior of modified human serum albumin (HSA) from penicillin-treated patients and in vitro conjugated samples was studied by isoelectric focusing in the absence and presence of 8 M urea. It is shown that samples classified as bisalbuminemic after separation under native conditions display a spectrum of several major bands with decreasing pIs when focusing is done in the presence of 8 M urea. In this spectrum, the distances between two consecutive major bands are as expected from a 2-unit charge difference. Since this result is compatible with the blockage of a lysine residue with a benzylpenicilloyl (BPO) group, each major band can be interpreted as representing an HSA fraction covalently linked to different numbers of benzylpenicilloyl groups. The separation methods presented therefore seem to constitute simple and reliable tools for a detailed assessment of the extent of BPO covalent binding to HSA both in vivo and in vitro.

Benzeneacetamides↗

PubMed1995

Specific staining of glycine N-methyltransferase.

Glycine N-methyltransferase from rabbit, human, rat and pig livers was separated by isoelectric focusing and a specific functional staining method was developed through the detection of sarcosine produced from the methylation of glycine. Isozyme patterns obtained in the various species tested differ both in the number of bands and apparent isoelectric points. These differences may explain the contradictory data on the subunit structure and glycosylation status of the enzyme reported so far.

Animals↗

PubMed1993

Subtyping of alkylated human orosomucoid: evidence for a duplicated gene, ORM1*F2S.

Isoelectric focusing of human orosomucoid (ORM) was studied following different sample treatment. It is shown that: (i) alkylation with iodoacetamide leads to a drastic change in the isoelectric point (pI) of both ORM1 F2 and ORM2 A gene products and greatly improves the discrimination between ORM1 F1 and ORM1 F2; (ii) previous reduction of the molecule with dithiothreitol partially inhibits the pI transitions with resultant artifactual ORM1 F1F2S patterns that correspond in most cases to F2S phenotypes. With the technique now described, the persistence of three ORM1 gene products was found in only one individual and the segregation analysis is consistent with the existence of a rare ORM1*F2S haplotype.

Alkylation↗

PubMed1993

Polymorphism of glucose dehydrogenase (GDH, EC 1.1.1.47): formal and population genetic data.

The polymorphism of glucose dehydrogenase (GDH) is demonstrated by isoelectric focusing of leucocyte extracts followed by enzyme staining. Segregation in 52 families with 145 children is consistent with the formal hypothesis of three common alleles, GDH*1, GDH*2 and GDH*3, at an autosomal locus GDH. Allele frequencies from 104 unrelated individuals from southwestern Germany were calculated as GDH*1 = 0.70, GDH*2 = 0.18 and GDH*3 = 0.12.

Alleles↗

PubMed1992

Genetic studies of antithrombin III with IEF and ASO hybridization.

Antithrombin III (AT III) was analyzed by two different methods. Isoelectric focusing was used to screen 3 different populations (southwest Germans, Portuguese, Xavante Indians). The same variant was detected both in the German and the Portuguese populations with frequencies of 0.007 and 0.00024, respectively. Further characterization of this variant was performed by allele specific oligonucleotides. By this means, it was possible to identify the variant as AT III Dublin, originally found in 4 Irish families.

Antithrombin III↗

PubMed1991

Separation of human alloalbumin variants by isoelectric focusing.

A technique for the separation of human alloalbumin variants by means of isoelectric focusing in the presence of 8M urea and 60 mM L-serine is described. The potential usefulness of this technique in the detection and classification of genetic heterogeneity at the albumin locus is demonstrated by the differentiation of three human alloalbumin variants of European origin.

Europe↗

PubMed1991

Orosomucoid (ORM 1) subtyping and formal genetics.

Orosomucoid (ORM) phenotyping has been performed in 141 families with 407 children from southwest Germany. Eight families were observed in which duplicated ORM1 genes, F1F2, F1F3, segregated. The family data gave no information about the presence of tandemly duplicated ORM1 F1F4 and ORM1 F1F5 genes. To date, the segregation of the phenotypes of the children agrees with the extended formal model: two ORM1 loci with two common (*F1, *S) and several rare (*F1F2, *F1F3, *F4, *F5) alleles. The parental allele frequencies were calculated by gene counting as ORM1 *F1 = 0.5781, *S = 0.3901, *F1F2 = 0.0195, *F4 = 0.0053, *F1F3 = 00.0035, *F5 = 0.0035.

Alleles↗

PubMed1991

Genetic polymorphism of inter-alpha-trypsin-inhibitor (ITI): formal genetic and linkage analyses.

The polymorphism of inter-alpha-trypsin-inhibitor, ITI, was demonstrated by isoelectric focusing in agarose gels (pH 5-8) followed by protein blotting and immunoassay. Segregation in 239 families with 677 children is consistent with the formal hypothesis that there are two common codominant alleles, ITI*1, ITI*2, and one rare codominant allele, ITI*3, at an autosomal locus ITI. Allele frequencies were calculated as ITI*1 = 0.600, ITI*2 = 0.393, ITI*3 = 0.007. Linkage analysis with 36 markers is presented. Slightly positive lod scores were obtained for PGM3 (zeta = 1.35, theta = 0.10) and AK1 (zeta = 1.34, theta = 0.10).

Alleles↗

PubMed1991

[Current status of linkage studies for gene localization in corneal dystrophies].

Corneal dystrophies with primarily autosomal dominant inheritance have been clearly identified both histologically and histochemically. No information is available to date on the causal enzymatic protein defect of the individual forms of dystrophy. By using linkage analysis to study families with various corneal dystrophies, an attempt is being made with polymorphous markers to find an indirect indication for localization in a chromosome. Numerous factors which exclude linkage can be named for granular, lattice and Schnyder's corneal dystrophy. Our linkage analysis studies of a second family with Schnyder's dystrophy support our indications of linkage with the sites for adenylate kinase (AK1) and the AB0 blood groups on chromosome 9.

Chromosome Aberrations↗

PubMed1990

Genetic studies on human thyroxine-binding globulin (TBG).

An enzyme immunoassay technique combined with Western blotting is described to demonstrate thyroxine-binding globulin (TBG) by isoelectric focusing in thin-layer polyacrylamide gels with 8 mol/l urea. Quantitative evaluation was by laser densitometry. No genetic charge variants of TBG were encountered in a sample of 840 unrelated individuals from southwestern Germany. There was no correlation between structural and quantitative variations in the TBG protein. Results from a family with quantitative TBG deficiency strongly support the postulated X-linked mode of inheritance. The method described can be considered as an additional diagnostic tool in thyroid evaluation.

Electrophoresis, Polyacrylamide Gel↗

PubMed1989

Linkage analyses of human peptidase C (PEPC), human factor H (HF), and coagulation factor XIIIB (F13B).

Linkage data on human peptidase C (PEPC), human factor H (HF), and coagulation factor XIIIB (F13B) are presented. The results confirm linkage between HF and F13B (lod = 5.32 at theta = 0.10 in males), and give strong evidence for linkage between PEPC and HF (lod = 5.14 at theta = 0.10 in males) and between PEPC and F13B (lod = 3.55 at theta = 0.10 in males). The claim that PEPA is linked with HF must be withdrawn.

Complement C3b Inactivator Proteins↗

PubMed1989

Genetic polymorphism of human peptidase C, PEPC (E.C.3.4.1.1): formal genetic and population data.

Human peptidase C, PEPC (E.C.3.4.1.1), exhibits a previously undescribed genetic polymorphism, detectable in red cells or leukocytes by starch gel electrophoresis. Segregation analyses on 161 families with 469 offspring support the formal genetic hypothesis of two codominant alleles at an autosomal locus. Since four rare variants have previously been described, we named the polymorphic allele PEPC*6. Gene frequencies from southwestern Germany were PEPC*1 = 0.721 +/- 0.018; PEPC*6 = 0.276 +/- 0.018, and PEPC*R = 0.003 +/- 0.002.

Alleles↗

PubMed1989

Linkage analysis in granular corneal dystrophy (Groenouw I), Schnyder's crystalline corneal dystrophy, and Reis-Bücklers' corneal dystrophy.

Tight linkage was excluded for 8 markers in 37 blood relatives from 3 families, 29 of whom had granular corneal dystrophy (Groenouw I). Inconclusive results were obtained for linkage with four marker loci. The highest positive LOD score was 0.57 for linkage between glutamic pyruvic transaminase and granular corneal dystrophy. Tight linkage was excluded for glyoxalase-1 in eight individuals from one family with Schnyder's crystalline corneal dystrophy. Results were inconclusive for another six markers. Positive LOD scores were obtained for linkage with adenylate-kinase 1 and the ABO blood group, with values of 1.16 and 0.67, respectively. Among six blood relatives with Reis-Bücklers' corneal dystrophy, the highest positive LOD score was 1.17 for linkage with mitochondrial malic enzyme. For another six markers informative for linkage analysis, the results were inconsistent.

Blood Group Antigens↗

PubMed1989

Electrophoretic and isoelectric focusing studies in Brazilian Indians: data on four systems.

Three-hundred ninety-nine individuals living in seven populations of two Brazilian Indian tribes (Macushi and Içana River Indians) were tested for the phosphoglucomutase 1 (PGM1), properdin factor B (BF), haptoglobin (HP), and alpha-1-antitrypsin (PI) systems. We observed significant internal heterogeneity in the two tribes for the PGM1 alleles and in the Macushi for the HP markers. Frequencies in three of the four systems (the exception being BF) also show clear differences in the Macushi and Içana River Indians. Compared with other ethnic groups, South American Indians generally present high frequencies of PGM1*1B, BF*S, HP*1S, and PI*M3. On the other hand, PGM1*1A, PI*M1, and PI*M2 are reduced, and HP*1F is absent or rare. This is the first report about HP subtypes among American Indians.

Brazil↗

PubMed1989

Isolated pericardial relapse following allogeneic bone marrow transplantation for acute myelogenous leukemia.

A 34-year-old male patient developed an isolated pericardial relapse of an acute myelogenous leukemia (M3) 11 months after marrow grafting from his HLA-identical brother. Alloenzyme pattern analysis revealed recipient type of the myeloblasts obtained from the pericardial effusion. Recurrence of the original leukemia was preceded by a reactivation of latent cytomegalovirus (CMV) infection which, in spite of a systemic humoral immune response to the virus, persisted in the pericardium as shown by dot-blot hybridization using CMV-specific DNA fragments. Activated T cells propagated with IL-2 from the pericardial effusion did not reveal any cytotoxic or restimulation capacity on the original or relapse myeloblasts, nor on other donor, recipient or NK target cells. Local coincidence of virus persistence and leukemic relapse suggested CMV-mediated modulation of the immune response in the pericardium with consequent induction of a proliferation of the original malignant cell clone. After local chemotherapy and one course of systemic treatment the patient is still in complete remission--longer than after the marrow grafting.

Adult↗