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C Kühn

Publications and source records attributed to C Kühn.

46 records · Page 3Linked to original sources
PubMed1993

[Early hemostasis after coronary therapeutic interventions by using a collagen plug].

Significant bleeding at the puncture site is one of the most important problems in the care of patients undergoing interventional coronary procedures like PTCA, rotablation, laser angioplasty or stent implantation. This is due to systemic application of heparin, acetylic salicic acid and, in stent patients, even additional coumadine. Furthermore, the interventional systems implement catheter systems with a large inner and outer lumen leading to increased vessel trauma. To decrease the risk of bleeding and to reduce the time of pressure dressing and bed rest, a bovine collagen plug (VasoSeal) was used in 600 consecutive patients undergoing one of the above-mentioned interventional procedures. In the majority of patients (pts.) (474/600 = 79%) either no (404 pts.) or minimal (70 pts.) bleeding occurred. Bed rest could be reduced from more than 24 h to 6-12 h. In 65/600 pts. (11%) significant bleeding developed which could be controlled by compression. Bed rest in these patients was 13-20 h. Larger bleedings or complications occurred in 61/600 pts. (10.2%) and could be controlled conservatively in all but eight patients. One patient (0.2%) had a narrowing of the artery at the puncture site after the procedure, probably due to intraarterial plug application. In another patient (0.2%) embolization of the plug into the popliteal artery occurred which could be treated by embolectomy using a Fogarty-catheter. Arteriovenous fistulae or aneurysms developed in 8/600 pts. (1.3%) but these are no specific complications of the hemostatic device. The plug could not be placed in 13/600 pts. (2%), mainly in the beginning of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Opening and closing movements of the heart valves in cardiopulmonary resuscitation. Confirmation of the cardiac pump theory ].

Cardiorespiratory arrest occurred in a 64-year-old man with severe triple-vessel coronary artery disease (status after two myocardial infarctions) and heart failure (ejection fraction of 20%). After intubation and starting resuscitation measures, transoesophageal echocardiography (TE) was performed to exclude electromechanical dissociation with ventricular tamponade. During the thoracic compression of closed-chest cardiac massage the aortic valve opened, while the mitral and tricuspid valves closed. During the relaxation phase the mitral and tricuspid valves rapidly opened, the aortic valve closed. When the cardiac massage was stopped (wide, fixed pupils) echo density increased spontaneously in all four cardiac chambers due to the cessation of blood flow. On resuming thoracic compression after about 30 sec the echo density decreased, first in the right ventricle, then right atrium, followed by left atrium and finally left ventricle. This is the first time that the wash-out of spontaneous echo-contrast has been reported in these circumstances. It makes it possible, together with the movements of the cardiac valves during thoracic compression, to state precisely the localization and direction of blood flow during closed-chest cardiac massage in man. The observations confirm the correctness of the cardiac pump theory rather than the thoracic pump one.

Aortic Valve↗
PubMed1991

Evidence for the 'cardiac pump theory' in cardiopulmonary resuscitation in man by transesophageal echocardiography.

There are two theories to explain the mechanism of blood flow during cardiopulmonary resuscitation: The 'Cardiac Pump Theory' and the 'Thoracic Pump Theory'. We have performed transesophageal echocardiography during the resuscitation of a patient with cardiopulmonary arrest. By this method we could study the motion of the aortic, mitral and tricuspid valves and the changes in ventricular size during cardiopulmonary resuscitation in man. We demonstrated an opening of the aortic valve during thoracic compression with simultaneous closure of the mitral and tricuspid valves. During relaxation of the chest, a rapid opening of the atrioventricular valves and closure of the aortic valve was noted. Short interruption of cardiopulmonary resuscitation to test for spontaneous heart action lead to echocontrast in all four heart chambers through stasis of blood, which resolved on continuation of cardiopulmonary resuscitation. This 'washing out' phenomenon enables visualization of blood flow through the aortic valve during compression, and through the mitral valve during relaxation. These observations favour the Cardiac Pump Theory as the predominant hemodynamic principle of blood flow during cardiopulmonary resuscitation in man.

Aged↗
PubMed1986

[Regional myocardial ischemia in the conscious dog under echocardiography control].

Regional myocardial dysfunction is a very sensitive and early parameter of myocardial ischemia. One minute occlusion of the left anterior descending (LAD (n = 8) and circumflex coronary artery (CCA) (n = 8) by means of hydraulic occluders was performed in 10 chronically instrumented conscious dogs. In a left ventricular cross-section diastolic and systolic area (DA, SA) and area shortening (AS) as well as regional function of 6 radial sectors were evaluated with 2D echocardiography. After occlusion of the LAD, SA increased by 33% (p less than 0.05), AS decreased by 22% (p less than 0.05) while the DA remained unchanged. In 2 of 6 radial sectors (anteroseptal) shortening decreased by 41% (p less than 0.01) and 54% (p less than 0.001) respectively. Occlusion of the circumflex coronary artery CCA caused an increase in DA (18%) and SA (33%) and a reduction of AS by 24% (p less than 0.01). Contraction of the anterior wall (sectors 2 and 3) was reduced by 61% and 57% (p less than 0.001). In the same animal 10 one minute occlusions of the LAD with 5 min intervals of reperfusion caused a reproducible depression of sector 6 (septal) from 63.2 +/- 5.4% to 16.3 +/- 3.4%. In another animal 11 one minute CCA occlusions with 5 min intervals of reperfusion reproducibly decreased the contraction of sector 3 (anterior) from 85.2 +/- 6.7% to 21.4 +/- 17.0%. 2D-E allows a reproducible estimation of regional left ventricular dysfunction during ischemia. Our model has the advantage that numerous studies can be performed in the same animal, so that the results can be compared intraindividually.

Animals↗
PubMedDate not supplied

A QTL for the degree of spotting in cattle shows synteny with the KIT locus on chromosome 6.

The proportion of unpigmented coat on the trunk was determined from photographs of 38 German Simmental and 627 German Holstein bulls distributed over three generations. All 665 animals were members of 18 Holstein and 3 Simmental half-sib families. A Bayesian estimation of heritability yielded a posterior mean of 0.88 and a standard error of 0.08. A quantitative trait loci (QTL) scan over all chromosomes covered by 229 microsatellite marker loci (2926 cM) was performed by fitting a multiple marker regression model to 625 observations from the youngest generation in 18 families. On chromosome 6 a QTL for the proportion of white coat with large effects (experiment-wise error probability < .0001) was found and a less important one on chromosome 3 (chromosome-wise error probability < .009). Chromosome 6 is known to harbor the KIT locus (receptor tyrosinase kinase), which is associated with various depigmentation phenotypes in mice, humans, and pigs. Similarity of phenotypic KIT effects in other species and synteny with the reported QTL suggest that KIT is a serious candidate gene for the degree of spotting in cattle. The results are also discussed with respect to resistance to solar radiation, heat stress, and photosensitization.

Animals↗
PubMedDate not supplied

Mapping of QTL for Body Conformation and Behavior in Cattle.

Genome scans for quantitative trait loci (QTL) in farm animals have concentrated on primary production and health traits, and information on QTL for other important traits is rare. We performed a whole genome scan in a granddaughter design to detect QTL affecting body conformation and behavior in dairy cattle. The analysis included 16 paternal half-sib families of the Holstein breed with 872 sons and 264 genetic markers. The markers were distributed across all 29 autosomes and the pseudoautosomal region of the sex chromosomes with average intervals of 13.9 cM and covering an estimated 3155.5 cM. All families were analyzed jointly for 22 traits using multimarker regression and significance thresholds determined empirically by permutation. QTL that exceeded the experiment-wise significance threshold (5% level) were detected on chromosome 6 for foot angle, teat placement, and udder depth, and on chromosome 29 for temperament. QTL approaching experiment-wise significance (10% level) were located on chromosome 6 for general quality of feet and legs and general quality of udder, on chromosome 13 for teat length, on chromosome 23 for general quality of feet and legs, and on chromosome 29 for milking speed. An additional 51 QTL significant at the 5% chromosome-wise level were distributed over 21 chromosomes. This study provides the first evidence for QTL involved in behavior of dairy cattle and identifies QTL for udder conformation on chromosome 6 that could form the basis of recently reported QTL for clinical mastitis.

Animals↗