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Biomedical subjects

A Ritter

Publications and source records attributed to A Ritter.

At least 73 records · Page 4Linked to original sources
PubMed1984

[Indirect study of oxygen consumption of the heart muscle].

The connection between the inner heart action in form of the double product and the physical functional capacity in watt (PWC) was controlled in patients with chronic ischaemic heart disease. For this purpose 64 patients with an average age of 47 years in the pulmological institute Mosdos and 25 patients with an average age of 53 years in the clinic for internal medicine of Berlin Humboldt University underwent a bicycle ergometer load. The double product, calculated from the systolic blood pressure and the heart rate, was regarded as measure for the myocardial oxygen consumption. It was established that there is a correlation between the inner heart action measured at the lover load level and the physical functional capacity in watt achieved simultaneously or later.

Angina Pectoris↗
PubMed1978

The influence of protonation or alkylation of the phosphate group on the e.s.r. spectra and on the rate of phosphate elimination from 2-methoxyethyl phosphate 2-yl radicals.

The e.s.r. spectra of 1-yl, 2-yl and 3'-yl methoxyethyl phosphate radicals derived from CH3OCH2CH2-OPO3H2 by hydrogen abstraction have been measured in aqueous solutions and the hyperfine constants determined. The coupling constants vary strongly with protonation or alkylation of the phosphate group. The 2-yl radicals eliminate phosphate. The rate-constants for the elimination (ke) have been estimated by e.s.r. measurements and by product studies as a function of pH using 60Co gamma-radiolysis. The ke values vary from approximately 0.3 s(-1) for the CH3OCHCH2OPO3--radical and approximately 10(3) s-1 for CH3OCHCH2OPO3H-, to approximately 3 X 10(6) S-1 for CH3OCHCH2OPO3H2. Alkylation of the phosphate group increases the elimination rate-constant to a similar extent as protonation. The results support a recent mechanism which described the OH-radical-induced single-strand breaks of DNA in aqueous solution starting from the C-4' radical of the sugar moiety. It is further concluded the C-4' radical of DNA eliminates the 3'-phosphate group faster than the 5'-phosphate group.

Alkylation↗