Adrenergic innervation of various sections of the heart in laboratory animals and man

By means of incubating slices in 2% glyoxylic acid solution, distribution of adrenergic fibers in the myocardium of various cardiac parts has been studied in the white rat, rabbit, cat, guinea pig and in the man. Both in the animals and in the man the distribution density of the adrenergic fibers of the myocardial plexuses in the auricle is higher than in the ventricle, and in the left half of the heart it is lower than in the right one. There are certain species differences in distribution of the adrenergic fibers. The density of the adrenergic fibers in the guinea pig myocardium is the highest, and in the white rat is is the lowest.     

Psychosocial stress in pregnancy and its relation to low birth weight.

The relation of low birth weight to psychosocial stress in pregnancy was examined using a life events inventory and a state anxiety index. Two hundred and fifty women were randomly selected and interviewed three times during pregnancy and shortly after delivery. Twenty six were excluded. Of the remaining 224 women, nine miscarried, 195 had healthy term babies, and 20 gave birth to babies that were either premature or of low birth weight at term. Low birth weight and prematurity were significantly associated with objective major life events but not state anxiety. The occurrence of objective major life events in the third trimester may be important in precipitating preterm labour. Cigarette smoking was the best predictor and objective major life events the second best predictor of low birth weight. The result was not dependent on social class. These findings suggest that cigarette smoking may be an important mediator of stress on the fetus. Antenatal care should take greater account of stress in pregnancy, and social support systems should be evaluated.     

Life expectancy, its relation to sexual activity and body weight in male inbred mice.

Body weight of male mice of five inbred strains caged in groups of five was determined three times between the ages of 80 and 100 days, representing the individual fully grown body weight. Sexual activity of each mouse (number of ejaculations and intromissions) was estimated under competitive conditions between the ages of 120 and 150 days in eleven repetitions. Within all inbred strains only about half of the males displayed sexual activity when confronted with an estric female. The other do not. The animals remained in their cage groups until natural death after 727 +/- 215 days (C57BL/6), 638 +/- 260 days (BALB/c), 630 +/- 187 days (CBA), 560 +/- 230 days (DBA/2) and 317 +/- 62 (AKR) days. Only amongst the sexually active animals did individual life span correlate with the number of ejaculations. This was seen in C57BL/6, CBA and DBA/2. Particularly sexually successful animals, carrying out the most ejaculations, live 10-20% longer than their (subdominant) competitors displaying less sexual success. Sexually inactive males (characterised by no ejaculations and less other sexual activities) show that this characteristic of their personalities imposes no limitation upon their life expectancy. Fully grown body weight and the individual life span correlates within the strains DBA/2, C57BL/6 and BALB/c. Medium-sized animals have a greater life expectancy than small or large ones.     

Individual differences in the ophthalmic artery and its branches in man

Structural peculiarities and topography of the ophthalmic artery and its branches have been studied in 105 mature persons. Owing to the topogapho-anatomical peculiarities, three parts of the ophthalmic artery have been detected; their form, size and interconnections with the surrounding formations are determined by the form of the skull and that of the orbit. The topography, structure and places where the ophthalmic artery branches get off are variable and have correlative connections with the orbital form.     

Length and weight changes in 0+ perch, Perca fluviatilis L., following fixation in formalin

Significant shrinkage and increase in weight followed fixation of 0+ freshwater Perca fluviatilis in formalin. Conversion values to obtain live values should take account of formalin concentration, fish size and holding time of preserved fish prior to measurement.     

On the molecular weight of pectic substances and its relation to their gel strengths

A study has been made on the possibility of determining the molecular weight M_w, the second virial coefficient A₂ and the radius of gyration by measuring the light scattering of pectin aqueous solutions. The experimental data were processed on a computer by using an algorithm, accounting for the effect of microgel formations in the pectic solution. A tendency towards a decrease in M_w when decreasing the degree of esterification for a certain type of pectin was established and was confirmed by the change in the intrinsic viscosity [η]. This fact is explained by degradation during deesterification.

The dependence of the gel strength of the pectic preparations on their degree of esterification, molecular weight M_w and purity (p%) was also studied as well as the dependence of the gel strength on the intrinsic viscosity [η], the degree of esterification and the purity p%. The passive multifactor experiment method was used to obtain regression models which were tested for an optimum in the factors influencing the gel strength. The optimal value for the degree of esterification was obtained at 57–58% which confirmed the view that within this range the pectin macromolecules possess maximum conformational flexibility.