Changes of euchromatin/heterochromatin ratios in cell nuclei of the aortic adventitia in diabetic rats.

The main objective of this study was to determine quantitatively euchromatin/heterochromatin (EU/HET) ratios of cell nuclei in the adventitia of 2 weeks streptozotocin induced diabetic rats combined with acridine orange (AO) ultracytochemistry. Specimens of the aorta above and below the orificium of the a. renalis were treated with AO and then prepared for electron microscopy.

Evidence of the heterogeneity of the proliferative capacity and for the selection of vascular smooth muscle cells with high proliferative activity in experimental diabetes.

The proliferative activity of cultivated aortic and venous smooth muscle cells (ASMC and VSMC) was estimated by 3H-thymidine autoradiography according to an exact time schedule in primary explant cultures and in the second subcultures of control and streptozotocin diabetic rats. The proliferative activity in both the primary and the subcultures was significantly higher in diabetes than in the control. The proliferative activity of VSMC was significantly lower than that of ASMC and it was not influenced by diabetes.

Metastable equilibrium with random local fluctuations: simulations of dynamic receptor pattern generation in a fluid mosaic membrane.

The generation of receptors in the animal cell's membrane was simulated by a model consisting of units in four possible states within a hexagonal area (playboard) of n units of a triangular network. The state of each unit was determined by the previous state of itself and of its six nearest neighbours, as regulated by a set of transition rules, which kept the mean relative frequency (m.r.

An advanced version of the dynamic receptor pattern generation model: the flux model.

In the recently described simple model of dynamic receptor pattern generation we used a two dimensional hexagonal area of a regular triangular network, formed by a statistically constant distribution of unit electostatic changes in a dynamic equilibrium. A set of 16 trnasition rules was applied to all units simultaneously; the next state of each unit depended only on the previous state of its six nearest neighbours, and the transition of the total pattern into the new one occurred in a single jump. Hence we designated the initial simple model as "jump model".

Alteration of chromatin in early experimental arteriosclerosis.

Our approach serves several purposes: To demonstrate the response of aortic cell nuclei to a changing environment (e.g. hypercholesterolemia, experimental diabetes, drug treatment), to apply the acridine orange (AO) ultracytochemical method, and to determine the euchromatin/heterochromatin (EU/HET) ratio by morphometric procedures as suitable criteria, and to emphasize the differential nuclear activity of adventitial cells.

[Predetermination of arthrosis, pain and limitation of movement in congenital hip dysplasia (author's transl)].

The purpose of this investigation was to find out, whether the onset of pain, arthrosis and decrease in mobility in different degrees of joint deformation is predictable for the indication of corrective surgery. When the correlation between of the onset of pain and arthrosis on one side and different measurements of joint deformation was tested, it turned out, that there is a significant correlation. If different age groups are built, however, we observe, that this correlation is given mainly in the youngest age group, where the most extreme dysplasias are found.