The influence of long-term application of isoproterenol on the results of temporary ischemia of the rat heart muscle

The results presented demonstrate that long-term application of small doses of isoproterenol produces an adaptive reaction in the heart muscle with increase of its tolerance of oxygen deficiency induced by temporary ischemia. After adapting animals in the described manner muscle necrosis appears delayed and to a smaller extent. Our results also emphasize the view that the definitive myocardial damage is determined by the secondary disturbances of microcirculation. Furthermore, our findings support the idea of a pharmacologically induced adaptation of the heart muscle resulting in an increased tolerance of ischemic injury.

[Significance of arterial hypertension in the pathogenesis of arteriosclerotic vascular changes]

Issuing from a description of the formal pathogenetic course of the arteriosclerosis and a global coordination of the essential risk factors to this process the importance of the hypertension in this process is emphasized. Its importance lies in fact that it becomes effective in the cooperation with other risk factors, particularly a dys- and hyperlipoproteinaemia, on various key mechanisms of the pathogenetic course. This concerns above all the permeability of the endothelium and the stimulation of the smooth muscle cells. Moreover, a hypertension has an essential influence on the degree of severity of the arteriosclerotic changes and their temporary appearance. The importance of the increased blood pressure is proved with the help of several instances. As it is shown by experimental results and also by findings in man, the unique hypertension does not lead to arteriosclerotic changes of the vascular wall, but to reaction of another kind.

Drug safety labeling for doctors

New labeling regulations to become effective later this year will make it easier for the doctor to determine the safety of a prescription drug for the use intended. Rx labeling for physicians will be required to carry pregnancy precautions for protection of mother and fetus, and safety data on adverse reactions, interactions with other substances, patient precautions on use, drug abuse and dependency status, and overdosage information.

Behavioral effects of low, acute doses of d-amphetamine on the dyadic interaction between mother and infant vervet monkeys (Cercopithecus aethiops) during the first six postnatal months

Doses of d-amphetamine sulfate (0.1, 0.15, and 0.2 mg/kg body weight) were given to adult monkeys in mother-infant pairs. The fundamental parental care behavior pattern was disrupted and the mother became isolated in a socially withdrawn phase. She did not respond to the calling signals of the infant and showed behavior in which stereotyped self-grooming and/or 'staring' into space were predominant. The reactions of the infant to this amphetamine-induced behavior were different in the two experimental pairs. In group 1 the infant increased its approach--avoidance movements. In group 2 the infant sat very quietly and close in front of the mother. The mother from group 1 reacted to the increased approaches from its infant with active rejection. In both groups the mothers did not react with the typical ventral--ventral grasping to either the infants sitting close or to the social anxiety signals of the infants. In spite of differences in behavior changes induced by amphetamine, the main conclusion is that the mothers totally lost their normal and highly biologic significant interest in their infants.

Behavioral effects of low, acute doses of morphine in nontolerant groups of rats in an open-field test

Groups of eight rats were treated with low, acute doses of morphine (2, 3.5, and 5 mg/kg body weight) or a corresponding volume of isotonic NaCl solution. The formation of groups, certain other features of social interaction, plus some individual items were recorded. Morphine induced an increase in the frequency of group formations without disruption of grooming and rearing patterns. The total picture of morphine-induced behavior changes at the dose levels used might be characterized as a polyactivation (or a varied stimulation); different from the selective stimulation reported for d-amphetamine.

Behavioral effects of low and high acute doses of morphine in solitary mice

The effects of morphine (5, 10, 100, and 150 mg/kg SC) on locomotor activity, object manipulation, grooming, rearing, and responsiveness to social stimulation were observed in naive, nontolerant mice. Morphine induced significant changes in the behavior elements recorded. Five and 10 mg/kg morphine caused an initial phase of about 1 h with inhibition of all activities. After 1 h the mice gradually increased activity and exceeded the corresponding placebo level at the end of the sessions. 100 and 150 mg/kg morphine caused an increase in locomotor activity. This hyperactive continuous running was stereotyped, restricted as it was to only a certain part of the experimental cage. Concurrently all other behavior elements were abolished. The animals did not normalize within the observation period. Neither the sedated mice with low doses nor the mice with high doses of morphine responded socially to the presence of another untreated mouse which was placed in the cage as a social response test.

[Does the concept for the prevention of chronic ischemic heart disease correspond to current ideas on etiology and pathogenesis of arteriosclerosis?]

A summarizing description of the essential relations between the existence of risk factors and the course of the morphologic changes in the arteriosclerosis in the intima is given. In this process the low density lipoproteins play an important role which together with further etiologic factors contribute to an increased permeability of the endothelium and to the stimulation of the proliferation and modulation of the smooth muscle cells, which are of central importance in the vascular reaction. Certain effects on the progression of the arteriosclerosis as well as a regression of adequate morphologic changes are to be expected from an elimination of risk factors, provided the necessary measures begin in the early stages of the arteriosclerosis, i. e. in the preatheromatous stage.

Behavioral effects produced by long-term administration of a neuroleptic drug (flupenthixol) upon social interaction in a group of eight rats

The behavioral effects produced by chronic treatment with alpha-flupenthixol decanoate followed by a 3-month pause upon social interaction in a group of eight rats were studied. alpha-Flupenthixol decanoate induced total disruption of two of the group formations studied, i.e., three or more in a group outside a corner and three or more following (running in a row)--the overall behavioral change shows a general depressive effect of the drug and a change in the pattern of social interaction. The shift in balance between the behavioral categories measured appeared as a significant difference in the time spent in the various group formations. Disintegration of group coherence, as shown in the measures of the degree of isolation, appeared only in the alpha-flupenthixol decanoate-treated group. An apomorphine test, which concluded the experiment 3 months after the last alpha-flupenthixol decanoate injection, revealed a significant difference in relation to licking response between the test group and the control group. The apomorphine test reported in this paper showed effects up to 90 days after the last drug treatment.

Keeping poisons and children apart

Every year thousands of young children, exploring the mysteries of cupboards and cabinets around the house, manage to get into more than simple mischief. A variety of harmful substances, ranging from corrosive acids to cosmetics and medicines are swallowed by these inquisitive youngsters. Poison Prevention Week, observed annually during the third week in March, serves to remind adults of their responsibilities for keeping poisons and children apart.

[The value of physical training as a preventive measure in chronic ischemic heart disease]

A critical valuation of the hitherto achieved results concerning the problems of the influence of a permanent training on the course of the chronic ischaemic heart disease with the following result is performed: -A perseverance training which was begun in adolescence and permanently continued allows to expect a genuine preventive effect concerning the chronic ischaemic heart disease, though not in every case. Moreover it certainly contributes to retard temporarily the beginning of the chronic ischaemic heart disease and to restrict the sequels of a myocardial infarction. -When a chronic ischaemic heart disease exists no effects on the arteriosclerosis in general and the sclerosis of the coronary arteries in particular is to be expected. These show a progredience which cannot be influenced by training. -Also the effects on the myocardium, particularly on the formation of collaterals and the evoking of adaptive effects in the myocardiac cell itself are not to be expected, when the chronic ischaemic heart disease has already developed. Nevertheless, under this condition a perseverance training seems to be not fully hopeless, since through peripheral effects and general effects secondary effects on the heart are possible.

The influence of diabetes mellitus and hypercorticism on the wound healing of experimental myocardial infarction in rats

In diabetic and glucocorticoid-treated rats myocardial infarction is produced by coronary artery ligation. After the ligation was performed the animals were given 3H-thymidine or 3H-proline at different times. The following parameters were determined: number of DNA- and tropocollagen-synthesizing connective-tissue cells both at the infarction border and infarction site; mean silver-grain density above the nuclei or cells; number of mitoses. The labelling and mitotic indices as well as the standard deviation (in percent) from the mean values were calculated. The following results were obtained: 1. The retarded formation of collagen fibres in diabetic animals is caused by a reduced number of tropocollagen-synthesizing fibroblasts and by a diminished synthesizing performance of the individual cells. 2. Glucocorticoids have a pronounced inhibitory effect on granulation-tissue formation, The 3H--thymidine indices are strikingly low. The synthesis of collagen precursors in the fibroblasts is reduced. The release of tropocollagen from the connective-tissue cells is slowed down.