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Biomedical subjects

L Dux

Publications and source records attributed to L Dux.

80 records · Page 5Linked to original sources
PubMed1981

Prostacyclin and prostaglandin synthesis in rat brain microvessels: characteristic changes in hypoxaemia.

The effects of hypoxaemia on the synthesis of prostacyclin and prostaglandins in the cerebral microvessels and on the ultrastructure of brain cortex capillaries were investigated in three groups of rats. Series I: rat embryos were kept in hypoxic-hypobaric condition for 42 hours. It resulted in the enhancement of synthesis of PG2alfa and PGE2 even two months after birth. The fine structure of the capillary endothelium remained without any pathological change. Series II: adult male rats were on hypoxic-hypobaric environment for 42 hours. There was a slight increase in the synthesis of PGE2 and PGD2 while the ultrastructure of brain capillaries was found to be normal. Series III: the hypoxic-hypobaric condition lasted for 240 hours in adult male rats. This long term hypoxaemia affected greatly the prostaglandin synthesis of brain cortex capillaries and resulted in changes in the fine structure of brain microvessels as well. The possible molecular mechanism activated by hypoxaemia in brain capillaries is discussed.

Animals↗
PubMed1980

LDH isoenzymes in muscle diseases.

The LDH isoenzyme pattern was investigated in biopsy material of muscles of children suffering from progressive muscular dystrophy and other neurogenic muscular disorders. An absence or pronounced activity loss of LDH 5 was observable in most of the cases. The proportion of subunits was the same in the diseased and the control muscles. Comparing the measured isoenzyme patterns with those expected from a random coupling of of the subunits, a lower percentage of LDH 5 and a higher one of LDH 4 was detected. The cause of the absence of LDH 5 is not a disturbance of M subunit synthesis but the post-translational inhibition of the tetramer forming process of the synthetised M subunits.

Adolescent↗
PubMed1978

The localization of calcium by X-ray microanalysis in myopathic muscle fibers.

An electron histochemical study was undertaken to localize calcium with ammonium oxalate precipitation technique in soleus muscle of rat in normal cases and in myopathy induced experimentally by a prolonged treatment of 2,4-dichlorophenoxyacetate (2,4-D). The calcium content of precipitates was detected by energy-dispersive X-ray microanalysis. In normal cases, the electron dense precipitates containing calcium were mainly found in the vesicles of sarcoplasmic reticulum, whereas in 2,4-D induced myopathy the deposits were shifted near the Z line into the myofibrils. Calcium, because the uptake into sarcoplasmic vesicles was inhibited by 2,4-D, could attach to other binding sites, such as to the troponin-C.A long-lasting binding of calcium might lead to a prolonged activation of the actin-myosin system.

2,4-Dichlorophenoxyacetic Acid↗
PubMedDate not supplied

Dynamic aspects of the incorporation of proteins into biological membranes.

The contributions of intramembranous and extramembranous segments of transmembrane proteins to frictional forces have been studied by covalently attached 14N- and 15N-indane dione and maleimide spin labels using saturation transfer electron spin resonance spectroscopy. The role of molecular size and membrane viscosity is discussed in determining rotational mobilities of proteins. By comparing the measured rotational correlation times with the predictions of hydrodynamic models the aggregation states of transmembrane proteins is estimated. On increasing the viscosity of the aqueous phase by polyols the viscous drag of the extramembranous segments of proteins is increased and from systematic hydrodynamic measurements the size of the protruding segments can be estimated. The role of slowed molecular diffusion is briefly discussed in the inhibition of enzymatic activity.

Biological Transport↗