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Biomedical subjects

P Decker

Publications and source records attributed to P Decker.

5 recordsLinked to original sources
PubMed1992

[Boerhaave syndrome in pyloric hyperplasia].

Boerhaave's-syndrome is a rare illness, usually caused when sudden intense vomiting leads to a spontaneous rupture of the healthy esophagus. Alcoholism and neurological diseases are considered to be the main predisposing factors. Because the complaint is so rare the casuistic of Boerhaave's-syndrome is described in connection with pyloric stenosis. In order to confirm the diagnosis the following practice is recommended: During gastrografin swallowing the pylorus should be examined in order to remedy the possible cause of the complaint when the operative therapy is carried out.

Esophageal Diseases↗
PubMed1991

[Rectal cancer with choriocarcinomatous differentiation].

Extragonadal choriocarcinoma are extremely rare. In the cases reported until now most of the extragonadal choriocarcinoma were localized in the stomach. The case described in this report is a carcinoma of the rectum with choriocarcinomatous elements. The specific biological, clinical and pathological characteristics of this carcinoma are discussed.

Aged↗
PubMed1979

[All-or-none behaviour and bistability in a simple cell model with autocatalysis of type A+2B = 3B (author's transl)].

Nonlinear kinetics in a chemical cell model involving only one substrate (A) and one product (B), two reactions (A yields B and A + 2B yields OB), and passive diffusion of A and B through the cell wall, can exhibit complex behaviour including oscillations, bistability (switching) and spiking. One such system is presented, which shows three kinds of response as depending on the quantity of a stimulus--a sudden imput of product B: i. no response; ii, spiking; iii, switching into an alternative steady state--i.e. an "all-or flip-or-none" response.

Animals↗
PubMedDate not supplied

Evolution in bioids: hypercompetitivity as a source of bistability and a possible role of metal complexes as prenucleoprotic mediators of molecular asymmetry.

Spontaneous production of optically active compounds can occur through kinetic instability of an asymmetric steady state in open systems, in which two enantiomeric autocatalysts compete for a common prochiral substrate in a stereoselective reaction of order n greater than 2. For the case of n=3, a proof of instability of a symmetric reacting state in the general case, and functions of reaction parameters ('Chemical Reynolds Numbers') governing the existence and stability of 7 different steady states are derived. The 'extinct state' (without autocatalyst) is stable; a finite amount of products is required to shift it into one of the reacting steady states. A mutation from one state into another in such system ('bioids') involves an amplification of different 'kinds of information', as 'stochastic' (noise into dissipative structures), 'molecular' (autocatalysts), and 'stoichimetric' information. Stereospecific third order kinetics are believed to be realizable on octahedral metal complexes with two-dentated ligands and to have played a role in the prebiological evolution of optically active compounds.

Biological Evolution↗