Effects of drag reducing polymer on atherosclerosis.

In order to determine the effect of drag reducing polymers on the occurrence of atherosclerosis, the Guinea pigs were used as the experimental animals. The inhibitory effect of a drag reducing polymer (polyacrylamide) on atherosclerosis in the aortas of Guinea pigs on a high cholesterol diet (2%) was investigated over a period of 6 months. The aortas, livers, kidneys and lungs of the animals, which were separated into four experimental groups (control, polymer, cholesterol and cholesterol + polymer) were also investigated both macroscopically and light microscopically. The selected physiological parameters such as, plasma cholesterol levels, plasma hemoglobin, hematocrit and total lipid values were determined at regular intervals for each group. The results indicate that the atherosclerosis in aorta of the animals receiving the polymer injection is suppressed significantly and the drag reducing water soluble polymers may be effectively applied against atherosclerosis.

Morphometric evaluation of the cardiac ventricular capacity of anencephalic fetuses.

Anencephaly occurs in 1:1,000 to 1:20,000 infants who are potential donors in pediatric heart transplantation, so it is important to define any morphologic differences between the anencephalic and normal heart in newborns. The dimensions of the heart in anencephalics, however, may differ. For example, the absence of cerebral tissue in anencephalic fetuses may decrease the heart load resulting in a smaller heart. The position of the heart in the thoracic cavity of an anencephalic fetus may affect the size and shape of the heart. This study compares the ventricular volumes and the inlet and outlet lengths of right and left ventricles in 11 normal and 11 anencephalic fetuses of gestational ages between 27 and 35 weeks. There was no statistically significant difference between the right ventricular volumes of normal and anencephalic fetuses, however, the difference between the left ventricular volumes was found to be almost statistically significant (P = 0.07). No statistically significant difference was found between the right and left ventricular volumes of normal fetuses; in anencephalic fetuses left ventricular volumes were found to be significantly smaller than right ventricular volumes (P = 0.05). The outlet length of the right ventricle and the inlet and outlet lengths of left ventricle in anencephalic fetuses were found to be short in comparison with those of normal fetuses (P = 0.01, P = 0.008, P = 0.01). It is proposed that anencephalics, because of these morphologic differences, should be reconsidered as possible donors for heart transplantation.

Ventricular myocardial thicknesses in anencephalic fetuses.

The heart of an anencephalic baby can be used as a donor after death. There exists insufficient information in literature, however, for the possible morphological differences in anencephalic hearts. This study compares ventricular myocardial thicknesses of anencephalic fetuses with normal fetuses in the same gestational age group. The comparison was made histologically on the slices taken from three levels of anterior and posterior walls of the left and right ventricles and from two levels of the interventricular septum. When each level was taken into account separately, the middle part of the left ventricular anterior wall was detected thinner in anencephalics (P = 0.010). When the mean value for each wall (anterior and posterior) was taken into account, left ventricular anterior wall was found thinner in anencephalics (P = 0.005). When the mean value for each ventricle was compared, the left ventricular wall was detected thinner in anencephalics (P = 0.025). These results support the idea that absence of the cerebral cortex results in modifications of the fetal heart. Because differences were limited to the left ventricular anterior wall non-homogenously, factors other than the decrease in the heart load (e.g., changes in intrathoracic anatomy) might also affect the myocardial features. When the mean value of right ventricle was compared to the left within the normal and anencephalic groups separately, the left ventricle was thicker than the right in normal fetuses (P = 0.016). In anencephalics the difference between two ventricular walls was insignificant (P = 0.084). This supports the left ventricular dominance in normal fetuses but not in anencephalics for the 27-34 weeks of age group. We suggest that when an anencephalic heart is intended to use as a donor, possible alterations presented in this article should be taken into account.