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Biomedical subjects

H Kuhn

Publications and source records attributed to H Kuhn.

At least 199 records · Page 11Linked to original sources
PubMed1978

Evolution of a genetic code simulated with the computer.

A simple selforganizing model system of molecules is considered and it is demonstrated by a computer simulation, that a genetic code of 16 elements (aminoacids) can gradually be formed by such a system in the course of many generations. By a number of rare chance events, each suppressing other events of equal a priori probability, a single code results out of an immense number of possible codes of the same a priori probability. The result is discussed in relation to the uniqueness of the genetic code in living systems. The computer simulation emphasizes a particular step in a model pathway discussed elsewhere consisting of many assumed physicochemical steps leading to a genetic apparatus.

Base Sequence↗
PubMed1978

Prognosis and possible presymptomatic manifestations of congestive cardiomyopathy (COCM).

In order to find evidence of prognosis and of presymptomatic manifestation of congestive cardiomyopathy (COCM) in fifty-eight patients, the extent of morphological changes of endomyocardial catheter biopsy (EMCB), clinical and haemodynamic data were correlated to the clinical course. In addition, clinical, haemodynamic, angiographic, morphological and His-bundle electrographic studies were performed in patients with left bundle branch block (LBBB), normal left ventricular end-diastolic volume, and normal coronary arteries (n = 43). Related to a 10-year mortality rate of 70% from the onset of symptoms, COCM is one of the most severe heart diseases. Endomyocardial catheter biopsy (EMCB) allowed clear prognostic separation in patients with COCM and seems to be of diagnostic value in patients with only slightly enlarged hearts and in patients with a short history of symptoms. The studies also revealed much evidence that at least some patients with LBBB, normal left ventricular end-diastolic volume (LVEDV) and normal coronary arteries exhibit an early stage of COCM. In these patients especially EMCB with severe changes of heart muscle cells and/or impaired left ventricular function may indicate subsequent COCM. So that there is now a new indication for performing EMCB.

Adult↗
PubMed1978

[The effect of some antiarrhythmic drugs on systolic time intervals in normal subjects (author's transl)].

Eleven healthy volunteers (mean age 30.1 +/- 4.3 yrs.) were repeatedly studied by measurement of systolic time intervals (QS2c, PEPc, LVETc, PEP/LVET) and arterial blood pressure (cuff method) before and after 24-hour oral application of four antiarrhythmic drugs (quinidine, disopyramide, prajmaliumbitartrate, propafenone) and two beta-blocking agents (propranolol, atenolol). The studies were repeated in the same group of volunteers with a different drug after an interval of one week. PEPc significantly increased after all antiarrhythmic agents at therapeutic doses by 6.1 to 9.4 ms (p less than 0.05 and p less than 0.01 resp.), whereas LVETc did not change significantly. PEP/LVET increased on an average by 0.033 +/- 0.006 (p less than 0.01). QS2c increased by 7.5 and 7.6 ms resp. (p less than 0.05) after prajmaliumbitartrate and propafenone. Heart rate remained unchanged after disopyramide and propafenone whereas it increased significantly (p less than 0.05) after quinidine and prajmaliumbitartrate. Blood pressure did not change significantly after any of these antiarrhythmic drugs. After application of the two beta-blocking agents propranolol and atenolol, no significant changes in STI could be observed. Mean arterial blood pressure significantly dropped after both, propranolol (minus 2.8 mm Hg) and atenolol (minus 9.7 mm Hg; p less than 0.05 and p less than 0.01, resp.). Heart rate decreased by minus 8.1 b.p.m. after propranolol (p less than 0.01) and minus 11.5 b.p.m. after atenolol (p less than 0.01). The results clearly indicate that at the dosage used, the four antiarrhythmic agents (quinidine, disopyramide, prajmaliumbitartrate, propafenone) exert a negative inotropic effect on left ventricular function as far as it can be judged from the measurement of STI. The lack of a significant negative inotropic effect of an oral treatment with beta-blocking agents on the STI can be explained by opposing effects of a decrease in blood pressure and a negative inotropic action.

Adult↗
PubMed1978

[The fluoroscopic detection of micro-calcifications of the breast during the operation in the excisional biopsy material (author's transl)].

In 101 excisional biopsies of the breast the biopsy material was examined fluoroscopically in the operating room for micro-calcifications with a specially constructed X-ray machine. This method of operation and control has the advantage of shortening the operative time and avoiding additional radiation to the breast. The surgeon becomes independent of a radiologist for control. Very accurate excisional biopsies of clinical obscure lesions in the breast become possible.

Adult↗
PubMed1978

[Differential diagnosis of metaphyseal dysplasias and osteodysplasty (osteodysplasty of Melnick and Needles) (author's transl)].

The article reports on 4 patients with rare modeling defects of the long bones. These defects are metaphyseal dysplasia, craniometaphyseal dysplasia, frontometaphyseal dysplasia, and osteodysplasty (osteodysplasty of Melnick and Needles). The differential diagnostic criteria are shown in a table to allow diagnosis already in children. This appears important in respect of the therapy to be employed (corrective surgery) and for prognosis, as well as for giving patients proper genetic and vocational advice.

Adolescent↗
PubMed1977

[Hypertrophic obstructive cardiomyopathy and lentiginosis (author's transl)].

Progressive cardiomyopathic lentiginosis was first described in 1972 by Polani and Moynahan. It is characterised by pigmentation of the skin (multiple symmetrical lentigines), hypertrophic obstructive cardiomyopathy and retarded growth. There may also be mental retardation. All characteristics of the syndrome were present in a 46-year-old woman. In addition there were also other features: lentigo developed at only 35 years of age, there was hypertelorism, thoracic kyphosis, and intermittent severe depression. Cyclic adenosine monophosphate in plasma was raised to 90.5 nmol/1.

Cardiomyopathies↗
PubMed1977

[The effects of mechanical disturbances caused by additional body section roentgenographic equipment on the tomogram (author's transl)].

Attention was called to the false images which can appear if additional body section roentgenographic equipment is improperly operated. In practice, the alterations on the tomogram, however, are usually so slight that they are barely noticeable and, for this reason, the disturbances can be overlooked. Additional body section roentgenographic equipment should, therefore, be constructed in such a way that operational errors are basically impossible.

Diagnostic Errors↗