Reference-strand-mediated conformation analysis of MHC alleles: a new method for high-resolution typing of the Ovar-DQB genes.
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Alleles↗
Biomedical subjects
R Fries
Publications and source records attributed to R Fries.
[Reconstruction of the bicuspid aortic valve].
Reconstruction of a regurgitant bicuspid aortic valve is a new alternative to aortic valve replacement. With concomitant aortic root dilatation adequate reconstruction is feasible by valve-sparing aortic replacement. Between 10/95 and 02/00, 30 patients underwent reconstruction of a regurgitant bicuspid aortic valve. Additional aortic replacement was performed in 23 cases. Valve reconstruction was performed by plication of the prolapsing leaflet. No patient died peri- or postoperatively. Freedom from aortic valve regurgitation > or = II as well as freedom from reoperation were 100% after 48 months. Reconstruction of a regurgitant bicuspid aortic valve is feasible with encouraging mid-term results. With concomitant dilatation of the ascending aorta, a combination of aortic replacement and valve reconstruction can achieve stable results even in bicuspid valve anatomy.
Adult↗
Comparative rest and exercise hemodynamics of 23-mm stentless versus 23-mm stented aortic bioprostheses.
BACKGROUND: The hemodynamic superiority of stentless valves at rest has been generally accepted, but there is a lack of studies on exercise hemodynamics. METHODS: We assessed aortic valve hemodynamics at rest and during exercise in 10 patients with a 23-mm stentless aortic bioprosthesis (Medtronic Freestyle; Medtronic Europe SA/NV, St. Stevens Woluwe, Belgium), in 10 patients with a 23-mm stented aortic bioprosthesis (Carpentier-Edwards, SAV, model 2650; Baxter Edwards AG, Horw, Switzerland), and in 10 healthy volunteers (control group) by means of Doppler echocardiography. RESULTS: Gradients at rest and gradients on comparable maximum exercise levels were significantly lower in patients with stentless valves compared to those with stented valves (rest: 6 +/- 2/11 +/- 4 mm Hg [mean/peak] versus 12 +/- 3/21 +/- 10 mm Hg; exercise: 9 +/- 3/18 +/- 6 mm Hg [mean/peak] versus 22 +/- 8/40 +/- 11 mm Hg). Patients with stentless valves revealed, in comparison to healthy young men, significantly higher gradients, but the small gradient difference of 3/7 mm Hg (mean/peak) at rest remained nearly unchanged throughout the exercise protocol (4/8 mm Hg [mean/peak] at 25 W, 4/9 mm Hg at 50 W and 4/9 mm Hg at 75 W). In contrast, the gradient difference between patients with stented and stentless valves increased significantly from one exercise level to the next (6/12 mm Hg [mean/peak] at rest, 8/14 mm Hg at 25 W, 12/17 mm Hg at 50 W, and 15/25 mm Hg at 75 W). CONCLUSIONS: A stentless aortic bioprosthesis seems to be an appropriate aortic valve substitute, especially in patients who perform regular physical exercise.
Aged↗
Mitral-valve repair without annuloplasty rings: results after repair of anterior leaflet versus posterior-leaflet defects using polytetrafluoroethylene sutures for chordal replacement.
OBJECTIVE: Defects of the anterior mitral leaflet (AML), including ruptured chordae, are often regarded as difficult or even impossible to repair. Chordal replacement may also be an option in extensive disease of the posterior mitral leaflet (PML). It has not yet been clearly defined whether the repair of either mitral leaflet using chordal-replacement techniques is as safe as the standard repair of the mitral valve (MV) including quadrangular resection and ring reduction alone. METHODS: Between October 1995 and June 1999, 160 patients underwent MV repair for mitral regurgitation (MR) in our institution. Chordal replacement with polytetrafluoroethylene (PTFE) sutures for elongated or ruptured chordae was performed in 72 (45%) patients. These patients were divided into two groups according to the location of the MV lesions: 48 patients with prolapse of the anterior or both leaflets (AML group) received an average of 2.2+/-1. 1 PTFE sutures for repair; in 24 patients with isolated PML defects (PML group), we used an average of 1.5+/-0.8 PTFE sutures. No prosthetic annuloplasty rings were used. Dilatation of the posterior mitral ring was corrected by PTFE suture annuloplasty. The remaining 88 patients underwent a standard mitral repair without chordal replacement. There were no statistically significant (NS) differences between the two groups (AML/PML) regarding age (59/62 years, P=0.49), left ventricular (LV) ejection fraction (64/66%, P=0. 6) and preoperative NYHA class (2.9/2.9, P=0.36). Postoperatively, all patients were followed by serial transthoracic echocardiography at 1 week and after 3, 6, 12 and 24 months by the same investigator. RESULTS: In-hospital mortality was 4.2% (2/48) in the AML group and 0% (0/24) in the PML group (P=0.55). Three of the AML patients (6. 3%) and one PML patient (4.2%) underwent reoperation for recurrent MR (P=1.0). The 1- and 2-year freedom from MV reoperation was 95. 1+/-3.4 and 92.6+/-4.2% in the AML group versus 95.0+/-4.9 and 95. 0+/-4.9% (P=0.67). The 1- and 2-year freedom from residual or recurrent MR grade 2 or higher was 97.6+/-2.4 and 94.9+/-3.5% (AML) versus 95.8+/-4.0 and 95.8+/-4.0% (PML) (P=0.97). CONCLUSIONS: We were unable to find statistically significant differences concerning mortality, freedom from recurrent MR and MV reoperation between the AML and PML groups. Extensive prolapse or chordal pathology of the anterior and PML can be corrected by chordal replacement. Using these techniques, stable repair can be achieved in more than 90% of patients at mid-term follow-up. Long-term observations are necessary to confirm the durability of this type of MV repair.
Adult↗
Chromosomal mapping of adenosine receptor genes in chicken suggests clustering of two members of the gene family.
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Animals↗
Differences in gene density on chicken macrochromosomes and microchromosomes.
The chicken karyotype comprises six pairs of large macrochromosomes and 33 pairs of smaller microchromosomes. Cytogenetic evidence suggests that microchromosomes may be more gene-dense than macrochromosomes. In this paper, we compare the gene densities on macrochromosomes and microchromosomes based on sequence sampling of cloned genomic DNA, and from the distribution of genes mapped by genetic linkage and physical mapping. From these different approaches we estimate that microchromosomes are twice as gene-dense as macrochromosomes and show that sequence sampling is an effective means of gene discovery in the chicken. Using this method we have also detected a conserved linkage between the genes for serotonin 1D receptor (HTR1D) and the platelet-activating factor receptor protein gene (PTAFR) on chicken chromosome 5 and human chromosome 1p34.3. Taken together with its advantages as an experimental animal, and public access to genetic and physical mapping resources, the chicken is a useful model genome for studies on the structure, function and evolution of the vertebrate genome.
Animals↗
Physical mapping of the interleukin-7 receptor gene (IL7R) to bovine chromosome 20q15-q17.
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Animals↗
Comparison of two different meat inspection techniques.
Field studies of meat inspection procedures in three different slaughter houses were performed in Germany, in 1996. In total 22,634 fattening pigs from 63 farms were inspected twice, using a visual and the traditional (mandatory inspection system) procedure. Statistical analysis was performed using the rate of ND+ (Non-Detected Positives) for both visual and traditional inspection. Neither the visual nor the traditional methods detected all lesions which were supposed to be in the lot of animals inspected. Some of the results could be explained by the nature and obviousness of the respective lesion. Conclusions regarding the future performance of inspection should not be drawn before a formal risk analysis procedure for the particular lesion has been done.
Abattoirs↗
Isolation and characterization of a new FHL1 variant (FHL1C) from porcine skeletal muscle.
Four and a half LIM domain protein 1 (FHL1) was initially described as an abundant skeletal muscle protein with four LIM domains and a GATA like zinc finger. FHL1 was shown to be expressed in skeletal muscle as well as in a variety of other tissues. Recently, alternatively spliced FHL1 mRNAs were identified coding for C-terminal truncated proteins. The tissue distribution of these variants is more restricted and their functional properties seem to be different. We have isolated and characterized a new variant of FHL1 from porcine skeletal muscle (FHL1C). FHL1C is characterized by a newly identified start codon resulting in a 16 amino acids longer N- terminal region. We have isolated and characterized the porcine FHL1C gene spanning approximately 14 kb and harboring six exons. Using primer extension analysis, the transcription start site of FHL1C was mapped, indicating that FHL1C is regulated by an alternative promoter. The tissue distribution of FHL1C expression was studied by RT-PCR. The porcine FHL1C gene was assigned to the distal part of the long arm of the X chromosome by fluorescence in situ hybridization and screening of a somatic porcine/rodent cell hybrid panel.
Alternative Splicing↗
Comparison of aortic valve gradient during exercise after aortic valve reconstruction.
PURPOSE: Aortic valve preservation is a promising alternative to conventional composite replacement of aortic valve and ascending aorta. This approach may have a physiologic benefit compared with valve replacement similar to that seen in mitral valve reconstruction. We investigated aortic valve gradients at rest and during exercise in patients who had undergone valve-preserving aortic replacement and compared them with composite replacement of valve and aorta. METHODS: Four groups were studied: nine patients underwent composite valve replacement (group A: valve diameter, 23 to 27 mm), eight patients underwent remodeling of the aortic root (group B), and another nine patients had reimplantation of the aortic valve (group C). Healthy volunteers were studied as a control group (group D). Using continuous-wave Doppler echocardiography, all patients were examined on a bicycle ergometer for aortic valve gradients (0 to 75 W). RESULTS: There were no differences among the groups with respect to age, body surface, left ventricular end-diastolic diameter, fractional shortening, or left ventricular mass. Maximum resting gradients were significantly elevated in group A compared with groups B, C, and D (group A: 21.3 +/- 7.1 mm Hg; group B: 9.0 +/- 4.5 mm Hg; group C: 8.6 +/- 3.7 mm Hg; group D: 4.9 +/- 1.6 mm Hg; p < 0.05). At 75 W, group A exhibited significantly higher gradients than all other groups (group A: 31.3 +/- 7.5 mm Hg; group B: 13.9 +/- 6.6 mm Hg; group C: 12.8 +/- 3.5 mm Hg; group D: 9. 2 +/- 1.9 mm Hg; p < 0.05). There was no significant difference among the other groups. Both valve-preserving groups had only insignificantly higher gradients than the control group. CONCLUSION: Our data strongly support the suggestion that preserving the aortic valve restores nearly normal hemodynamic function of the aortic valve. Long-term observations will have to prove the clinical relevance of restoring physiologic aortic valve hemodynamics.
Adult↗
Structural analysis and transcript processing of the bovine proteolipid protein (PLP) gene.
In this study we present the complete genomic structure of the bovine PLP gene and its assignment to the long arm of the X-chromosome (BTXq2.1). We determined a total of 18,767 bp of the bovine PLP gene and compared it to the human heterolog. A very high similarity was detected between the non-coding regions, interrupted primarily by several transposable elements. A deletion of 13 bp in the vicinity to the translation start signal in the promoter of the bovine PLP gene was found. Functional studies of the 3' region showed the use of several polyadenylation signals. Three main transcripts were detected in adult cattle in the range of 3200, 2400, and 1600 nucleotides using Northern blot analysis. An additional shorter transcript was detected in the cerebrum of calves.
Alternative Splicing↗
[Procedures in abattoirs and meat inspection. State of the discussion on the implementation of alternative systems].
Results of field studies which were performed in EU member states and which dealt with meat inspection procedures in fattening pigs were reviewed with respect to their contribution to alternative systems of meat inspection. The following was concluded: Inspection ante mortem (monitoring of circumstances at the farm of origin): Data which should be given to the notice of the authorities have not yet been satisfactorily defined and their informative value still is not yet clear The predictive character of information from the farm of origin regarding the health status of the animals (results of meat inspection) is not yet sound enough The technique of ante mortem inspection should be reconsidered also. Meat inspection (monitoring and assessment of lesions): In all studies the compared techniques (visual and official procedure) did not entirely find all lesions, which were supposed to be on the carcasses and organs. This was true in different percentages. The impact on consumer's health from the lesions monitored has to be discussed more thoroughly. The information presently available is not yet sound enough to generate a new practicable system of meat inspection. Further pilot studies are necessary.
Abattoirs↗
[Reconstructive surgery of the aortic root].
Surgical treatment of proximal aortic disease traditionally consists of composite replacement of valve and aorta. Recent reconstructive procedures on the aortic root allow for treatment of aortic dilatation and concomitant aortic valve regurgitation without the associated disadvantages of mechanical heart valves. From 10/95 to 09/99 we treated 84 patients for regurgitation of the aortic valve and dilatation of the aortic root. Valve preserving replacement of the root consisted of root remodeling (n = 68) or reimplantation of the aortic valve (n = 16). Operative mortality in valve-preserving surgery was not elevated compared to overall results of proximal aortic replacement (3.6% vs 5.6%); this applied to elective procedures (1.8% vs 2.3%) as well as emergency operations (9.3% vs 16.3%). Initial aortic valve function was adequate in all cases. Actuarial freedom from regurgitation grade II or higher was 98% after root remodeling and 92% after valve reimplantation. Freedom from reoperation at two years was 96% in remodeling and 100% in valve reimplantation. Hemodynamic function of the reconstructed valve was investigated in 17 patients under conditions of rest and exercise. These were compared to 9 patients with a mechanical composite valve. Patients with reconstructed valves had almost physiologic gradients during rest and exercise. These gradients were thus significantly lower than the increased gradients of patients after composite replacement. Application of reconstructive procedures to the aortic root allows for restoration of aortic valve function in the majority of patients. Disadvantages of heart valve prostheses can be avoided, and the hemodynamic performance of the reconstructed valve appears almost physiologic.
Adolescent↗
The dynamics of chromosome evolution in birds and mammals.
Comparative mapping, which compares the location of homologous genes in different species, is a powerful tool for studying genome evolution. Comparative maps suggest that rates of chromosomal change in mammals can vary from one to ten rearrangements per million years. On the basis of these rates we would expect 84 to 600 conserved segments in a chicken comparison with human or mouse. Here we build comparative maps between these species and estimate that numbers of conserved segments are in the lower part of this range. We conclude that the organization of the human genome is closer to that of the chicken than the mouse and by adding comparative mapping results from a range of vertebrates, we identify three possible phases of chromosome evolution. The relative stability of genomes such as those of the chicken and human will enable the reconstruction of maps of ancestral vertebrates.
Animals↗
The cattle interleukin-13 gene: genomic organization, chromosomal location, and evolution of the promoter.
Interleukin (IL)-13 plays a key role in the T-helper 2 type immune response. In domestic animal species no sequence information is available for the IL13 gene. Here, we report the isolation and sequencing of the cattle IL13 gene. Since a heterologous cDNA probe failed to hybridize to cattle genomic DNA the gene was identified by a positional sequencing approach. In human and mouse both cytokines are located within a region of about 30 kilobases (kb). Therefore the region upstream of the cattle IL4 gene has been sequenced by a shotgun approach. The cattle IL13 gene was found to be located about 20 kb upstream of IL4 in a head-to-tail orientation. The exon-intron structure and the promoter region is well conserved across species. The alignment of the IL13 sequences from different species allowed the identification of highly conserved amino acid positions and transcriptional elements. Two conserved amino acid positions (glu(31) and pro(94)) are most probably homologous to the interleukin-4 signalling residues. One of the potential binding sites for transcription factors is located at position -197 to -189 and is closely related to the P elements of the IL4 promoter. Nevertheless, the overall identity of the promoter sequences of IL13 and IL4 is low. Therefore we conclude that both cytokines use diverse regulatory elements. There is evidence that IL-13, but not IL-14, is the key mediator in allergic asthma. Furthermore IL-13 is involved in resistance to some infections. Therefore IL-13 is of interest for disease association studies in domestic animals.
Amino Acid Sequence↗
Molecular cloning and chromosomal assignment of the porcine 54 and 56 kDa vacuolar H(+)-ATPase subunit gene (V-ATPase).
Vacuolar proton-translocating ATPases (V-ATPase) are multisubunit enzyme complexes located in the membranes of eukaryotic cells regulating cytoplasmic pH. So far, nothing is known about the genomic organization and chromosomal location of the various subunit genes in higher eukaryotes. Here we describe the isolation and analysis of a cDNA coding for the 54- and 56-kDa porcine V-ATPase subunit alpha and beta isoforms. We have determined the genomic structure of the V-ATPase subunit gene spanning at least 62 kb on Chromosome (Chr) 4q14-q16. It consists of 14 exons with sizes ranging from 54 bp to 346 bp, with a non-coding first exon and an alternatively spliced seventh exon leading to two isoforms. The 5' end of the V-ATPase cDNA was isolated by RACE-PCR. The V-ATPase alpha isoform mRNA, lacking the seventh exon, has an open reading frame of 1395 nucleotides encoding a hydrophilic protein of 465 amino acids with a calculated molecular mass of 54.2 kDa and a pI of 7.8, whereas the beta isoform has a length of 1449 nucleotides encoding a protein of 483 amino acids with a calculated molecular mass of 55.8 kDa. Amino acid and DNA sequence comparison revealed that the porcine V-ATPase subunit exhibits a significant homology to the VMA13 subunit of Saccharomyces cerevisiae V-ATPase complex and V-ATPase subunit of Caenorhabditis elegans.
Amino Acid Sequence↗
High-resolution, human-bovine comparative mapping based on a closed YAC contig spanning the bovine mh locus.
A closed YAC contig spanning the mh locus was assembled by STS content mapping with seven microsatellite markers, eight genes or EST, and nine STS corresponding to YAC ends. The contig comprises 27 YACs, has an average depth of 4.3 YACs, and spans an estimated 1.2 Mb. A linkage map was constructed based on five of the microsatellite markers anchored to the contig and shown to span 7 cM, yielding a ratio of 160 kb/1 cM for the corresponding chromosome region. Comparative mapping data indicate that the constructed contig spans an evolutionary breakpoint connecting two chromosome segments that are syntenic but not adjacent in the human. Consolidation of human gene order by means of whole genome radiation hybrids and its comparison with the bovine order as inferred from the contig confirm conservation of gene order within segments.
Animals↗
Construction and characterization of a porcine P1-derived artificial chromosome (PAC) library covering 3.2 genome equivalents and cytogenetical assignment of six type I and type II loci.
A porcine P1-derived artificial chromosome (PAC) library of a male German Landrace pig was constructed in pCYPAC2. In total 90,240 clones were generated and individually transferred into microtiter plates. An average insert size of 119.1 kb was determined by analyzing 150 randomly selected PAC clones by pulsed field electrophoresis, yielding approximately 3.2 genome equivalents. The stability of nine clones was followed through 110 generations showing no reduction of the insert size. The probability of identifying a specific chromosomal region within the library was tested by screening for the presence of seven type I and five type II loci. The analysis showed that most loci (10/12) were present in the library at least twice. To determine the percentage of chimerism, six clones were analyzed by fluorescence in situ hybridization (FISH) on metaphase chromosomes. We assign one type I locus (Triadin) and three type II loci (SW855, S0300, SW1129).
Animals↗