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Biomedical subjects

R Hanke

Publications and source records attributed to R Hanke.

At least 19 recordsLinked to original sources
PubMed1994

Polymorphism in the human E-selectin gene detected by PCR-SSCP.

By using the non-isotopic single-strand conformation polymorphism (SSCP) technique to analyse products of the polymerase chain reaction (PCR), we detected a 561-adenine to cytosine substitution resulting in an amino acid exchange from serine to arginine at position 128 of the E-selectin gene. If this amino acid substitution has an effect on the adhesion of blood cells to the endothelium, the polymorphism could be of interest with respect to association studies in a number of pathological conditions, such as cardiovascular diseases.

Base Sequence↗
PubMed1993

Prenatal diagnosis of the acute form of proximal spinal muscular atrophy: experience on the acceptance of linkage analyses by the families.

The acute form of proximal spinal muscular atrophy (SMA) is a severe autosomal recessive inherited neuromuscular disorder. It has been mapped to chromosome 5q 11.2-13.3. Using restriction fragment length polymorphisms (RFLPs) or (CA)n repeats of DNA probes in this region, prenatal diagnosis is, in principle, possible. Misdiagnosis can be due to incorrect diagnosis in the index patient, and crossing-over events. Using the DNA probes D5S6, D5S112, D5S39, and D5S78, we cover a region of 10.4 mega-base pairs (Mbp) of partially NotI-digested genomic DNA without overlap of fragments. The DNA probes D5S6 and D5S112, most likely flanking the SMA gene, cover a distance of about 6.6 Mbp. This corresponds to the genetic distance of 6 cM (Morrison et al., 1992; Daniels et al., 1992). But since the precise localization of the SMA gene is still unknown (Simard et al., 1992), a 10 per cent risk of misdiagnoses due to crossing-over events cannot be excluded. The acceptance of this 10 per cent risk for prenatal diagnoses differs in SMA families. We observed a case in which a woman accepted a 25 per cent risk because RFLPs and (CA)n repeats were both uninformative. In contrast, another family did not accept the minimal 10 per cent risk and the pregnancy was terminated. In two families, we performed prenatal diagnosis by linkage analysis. One child predicted to be healthy has been born in the meantime and has shown no indication of SMA during her first 8 months.

Acute Disease↗
PubMed1993

Point mutations at the carboxy terminus of the human dystrophin gene: implications for an association with mental retardation in DMD patients.

Duchenne and Becker muscular dystrophies (DMD/BMD) are caused by mutations in the human dystrophin gene. About two-thirds of DMD/BMD patients exhibit gross rearrangements in the gene whereas the mutations in the remaining one third are thought to be point mutations or minor structural lesions. By means of various progressive PCR-based techniques hitherto a number of point mutations has been described that in most cases should cause premature translational termination. These data indicate a particular functional importance for the C-terminal region of dystrophin and consequently for its gene products Dp 71 and Dp 116. To screen for microheterogeneities in this gene region we applied PCR-SSCP analysis to exons 60-79 of twenty-six DMD/BMD patients without detectable deletions. The study identified seven point mutations and one intron polymorphism. Six point mutations, found in DMD patients, should cause premature translational termination. One point mutation, identified in a BMD patient, results in an amino acid exchange. Five of the DMD patients bearing a point mutation are mentally retarded suggesting that a disruption of the translational reading frame in the C-terminal region is associated with this clinical finding in DMD cases. Therefore our data raise the possibility, that Dp 71 and/or Dp 116, the C-terminal translational products of dystrophin, may be causally involved in cases of mental retardation that are associated with DMD.

Amino Acid Sequence↗
PubMed1993

Non-isotopic analysis of single strand conformation polymorphism (SSCP) in the exon 13 region of the human dystrophin gene.

More than 30% of Duchenne and Becker muscular dystrophy (DMD/BMD) patients have no gross DNA rearrangements like deletions or duplications. The large size of the coding sequence of the dystrophin gene (11 kilobases) complicates systematic identification of point mutations. Recently reported approaches based on genomic DNA or mRNA show that chemical cleavage of mismatches is an effective but time consuming and technically demanding method for the identification of point mutations in the human dystrophin gene. We have used a fast and convenient system consisting of PCR amplification of genomic DNA, non-isotopic SSCP analysis, and direct sequencing of PCR products for the detection of mutations in exon 13 and adjacent intron sequences. Sixty-eight DMD patients without detectable deletions or duplications were analysed, resulting in the identification of a point mutation in the coding sequence and two polymorphisms in the 5' flanking intron. The C to T change of the first nucleotide in the third triplet leads to a stop codon and seems to be the cause of the functional deficiency of the gene product in this patient.

Base Sequence↗
PubMed1993

Alternative splicing of dystrophin mRNA complicates carrier determination: report of a DMD family.

Carrier determination is important for genetic counselling in DMD/BMD families. The detection of altered PCR amplified dystrophin mRNA fragments owing to deletions, insertions, or point mutations has increased the possibilities of carrier determination. However, problems may occur because of alternative splicing events. Here we present a family with a DMD patient characterised by a deletion of exons 45 to 54. At the mRNA level we detected a corresponding altered fragment which served for carrier determination. The mother and the sister of the patient showed the same altered dystrophin mRNA fragment as the patient and are therefore carriers. In the mother two additional altered dystrophin mRNA fragments were detectable, obviously resulting from alternative splicing in the normal allele. The grandmother and two other related females of the patient possess only the normal mRNA fragment. In a further female we detected an altered fragment owing to an mRNA deletion of exon 44. This fragment is created either by alternative splicing or a new mutation. Therefore, the carrier status of this female is still ambiguous indicating problems in carrier determination by the method of dystrophin mRNA analysis.

Alternative Splicing↗
PubMed1990

Deletion analysis of DMD/BMD families from the German Democratic Republic and selected regions of Czechoslovakia and Hungary.

Over the last two years we have screened 183 DMD/BMD families requesting prenatal diagnosis. Using cDNA probes cf56a,b we have detected exon deletions in 72 of them. In 62 cases the deletion was also detectable with currently available PCR primers. Deletion analysis for exons 8, 17, and 19, using either PCR or Southern blotting techniques, was performed for 65 of the 111 families which showed no deletions with cf56a,b. Eight of them were deleted for one or more of these exons. PCR offers new possibilities for deletion analysis in families without a living patient using either Guthrie papers or histologically conserved material from the dead patient. In 20 of 25 patients, we observed concordance between the clinical picture and the molecular deletion analysis in accordance with the open reading frame hypothesis. Five patients, however, presented with DMD in spite of our analysis showing an in frame deletion. Carrier determination in families in which DMD is caused by a deletion using linkage, dosage, or breakpoint analysis is discussed.

Blotting, Southern↗
PubMed1989

Possibilities and limitation of prenatal diagnosis and carrier determination for Duchenne and Becker muscular dystrophy using cDNA probes.

Two cDNA probes, cf23a and cf56a, identify deletions of selected exons in about 50% of our DMD/BMD patients. We have estimated the most likely order of the 11 exons detectable with both probes with respect to the different extensions of the deletions. In one of our BMD pedigrees, the observed deletion could be traced in the affected males through three generations. This result shows that with the use of cDNA probes detecting deletions, the only risk of error in genomic prenatal diagnosis is the general high frequency of new mutations for DMD/BMD. This is important progress in diagnosis compared to the 2 to 5% risk of misdiagnosis because of crossing over events using conventional linkage analysis with bridging or intragenic probes. The first prenatal diagnosis of an unaffected fetus of a woman who is a DMD carrier according to ultrasound examination is described. In one of our DMD males, the cDNA probe cf56a detects a deletion breakpoint. His sister also shows the altered band and is therefore a DMD carrier, while his mother has a totally normal band pattern. The interpretation of this observation could be either germline mosaicism or two identical new mutations. The identification of deletion breakpoints is a new diagnostic strategy, especially for carrier determination, which excludes misdiagnosis owing to crossing over events and the problems of dosage estimation. It is, however, limited by the low frequency of breakpoints detectable with cDNA probes. Therefore, the generation of new intron probes in this region is an important goal.

Chromosome Deletion↗
PubMed1988

[The cattle breeding program of the Republic of Cuba].

The Cuban cattle breeding programme has remained unchanged over more than 20 years and aims at the genetic transformation of the indigenous population by means of crossbreeding within a high-performance cattle stock. Focus is on the breeds Holstein X Zebu in order to produce the crosses "Holstein Tropical" (7/8H 1/8Z), "Mambi" (3/4H 1/4Z), and "Siboney" (5/8H 3/8Z). Besides these, other new breeds are envisaged for milk and meat production. Representative parameters of the production and reproduction of the new genotypes are being reported and discussed.

Animals↗
PubMed1987

Use of cyanuric chloride-activated paper for detection of subpicogram quantities of specific DNA sequences and its application to linked restriction fragment length polymorphism analysis in a Duchenne muscular dystrophy affected family.

Conditions for the optimal use of cyanuric chloride-activated (CCA) paper in Southern transfer hybridization experiments of genomic DNA were investigated. They depend critically on pH and ionic strength during transfer and on the composition of the hybridization solution. Simplified hybridization conditions using a SSC/dextran sulfate system at 65 degrees C without sodium dodecyl sulfate and the complex Denhardt's solution are applied. CCA paper allows repeated use in hybridization experiments. Under optimized conditions CCA paper allows a more sensitive detection of single-copy gene sequences in the subpicogram range than do nylon membranes. Application of these transfer and hybridization conditions with our newly developed CCA paper to carrier determination and prediction of the healthy male haplotype demonstrates its usefulness for prenatal counseling of a Duchenne muscular dystrophy family.

DNA↗
PubMed1986

Possibilities and problems in genomic diagnosis of Duchenne muscular dystrophy with molecular probes.

Selected families affected with Duchenne muscular dystrophy from an extensive pedigree analysis with linked restriction fragment length polymorphisms and creatine kinase estimations are compiled to demonstrate the various counselling situations for carrier determination and prenatal diagnosis. The creatine kinase determination suffers from approximately 30% false negative values in carrier determination. The DNA analysis is limited by the uninformativity of the DNA markers and the occurrence of meiotic crossovers between the particular restriction fragment length polymorphism pattern and the Duchenne muscular dystrophy locus. The use of markers bridging the Duchenne muscular dystrophy locus, such as 754 and C7, is presently best suited for this purpose but is applicable to only a relatively small number of cases. The use of the physically closer probe, pERT 87, is much more informative althrough it too recombines with the Duchenne muscular dystrophy locus. DNA analysis allows prenatal diagnosis for unaffected boys from the restriction fragment length polymorphism pattern confined to the healthy grandpaternal X-chromosome in cases where the carrier status of the mother is established or in doubt. As in the case of carrier determination, crossover events and uninformativity of restriction fragment length polymorphisms limit the feasibility of this approach.

Alleles↗
PubMed1986

Typing of families with classical phenylketonuria using three alleles of the Hindiii linked restriction fragment polymorphism, detectable with a phenylalanine hydroxylase cDNA probe. Family typing for PKU by linked HindIII RFLP.

A human phenylalanine hydroxylase cDNA clone was isolated from a human liver cDNA library. The size of the cDNA insert is approximately 2.4 kb and appears to be a near full length copy of a phenylalanine hydroxylase mRNA. This cDNA was used to probe for HindIII restriction enzyme polymorphisms in heterozygote typing of families with phenylketonuria. The use of three alleles of this polymorphism, as opposed to the two alleles as previously described, increases the informativity for typing - and therefore also for prenatal diagnosis - in certain families from 75% to 100%.

Alleles↗
PubMed1985

Human X chromosome markers and Duchenne muscular dystrophy.

Two DNA markers, a random DNA fragment 754 and the cDNA sequence encoding the gene for ornithine transcarbamylase (OTC) have been studied in kindreds segregating for Duchenne muscular dystrophy. 754 and OTC are located close physically to the mutation in the region Xp21 below the breakpoints in two Duchenne females. The genetic distance was found to be approximately 10cM between 754 and DMD (two crossovers in 26 meioses) and to be approximately 10cM between OTC and DMD (two crossovers in 26 meioses). Physical data suggest the order DMD-754-OTC. The frequency of recombination compared to physical distance between these markers and DMD suggests that there may be a hot spot of recombination. The relevance of these observations for the isolation of the DMD mutation and clinical use of these probes is discussed.

Chromosome Mapping↗
PubMed1985

[Use of sugar cane harvest residues in cattle fattening in the Republic of Cuba. 1. The physical and chemical composition of the residues and the effect of NaOH treatment on their in vitro and in vivo digestibility].

The harvesting remains of sugar cane (crowns, leaves, sheaths, parts of stalks), which are rich in crude fibre, were investigated. The content of crude nutrients, their digestibility and the energy concentration of the harvesting remains largely correspond to the values of cereal straw. After the treatment with growing amounts of NaOH (0, 4, 6, 8, 10 g/ 100 g DM) a significantly increasing digestibility of the dry matter (31.9, 47.0, 56.1, 61.9, 67.6%) was ascertained in in-vitro experiments. In digestibility experiments with wethers an increased digestibility of the dry matter from 36.6 to 57.6% and of the energy from 39.3 to 56.2% after the treatment with 4 g NaOH/100 g DM could be ascertained in comparison with untreated harvesting remains. Energy concentration increased from 324 to 445 EFU cattle/kg DM and thus approached that of the hay of Bermuda grass (Cynodon dactylon), one of the most important fodder grasses of Cuba. After the feeding of harvesting remains treated with NaOH significant changes in the water and mineral metabolism could be ascertained.

Animal Feed↗
PubMed1983

[Round atelectasis].

a) For several reasons Sinner's paper calls for critical remarks: His term "Pleuroma" for a neither pleural nor tumorous but intrapulmonary and atelectatic mass lesion lacks any anatomical and histological basis and is misleading at that because it pretends a tumor of the pleura; his statement in the summary that atelectatic pseudotumors of the lung show a tumorcell-like cytoarchitecture is surprising without being further discussed by the author; he encourages risky invasive diagnostical procedures even in cases where the radiological diagnosis of round atelectasis is unmistakable; already known radiologic features of round atelectases are presented by him as hitherto undescribed; his conceptions of the formal development of round atelectases and of their most characteristic features can not be agreed with. b) The different forms of round atelectases and their residuals are presented with tomograms and with diagrams of their formal development from our point of view.

Bronchiectasis↗