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Biomedical subjects

L F Resele

Publications and source records attributed to L F Resele.

9 recordsLinked to original sources
PubMed1979

Venotonic activity of escin on the human saphenous vein.

The venotonic effects of escin on the human saphenous vein have been evaluated in vitro on histologically normal venous segments obtained during surgical saphenectomy procedures. It is necessary to use the human preparations because of the great variability in the responses of the veins of different species. By using a standard stimulus and fitting the experimental data to the logistic function, we were able to compare the activity of escin with those of the commonly used venotonic agents. Stimulation with escin always induced an increase in venous tone which was constant for a given dose and stable for some time, and maintained for as long as an hour after removal of the substance from the bath. The maximum contraction obtained with escin was similar to those obtained with serotonin and dihydroergotamine, significantly greater than that obtained with acetylcholine or vasopressin. However, the affinity of escin was found to be lower than those of the other substances studied. An increase in venous tone, and therefore a decrease in the volume of the venous district, would be considered a very favorable result to be obtained with a drug which, like escin, is indicated for treatment of venous diseases leading to irreversible dilation.

Escin↗
PubMed1977

Neurophysiological aspects and learning processes in schizophrenic patients.

Two groups of schizophrenic patients (acute and chronic subjects) were observed in order to study possible differences in neuropsychological performances and their relationship with symptomatology. 16 acute and 16 chronic patients, aged 18 to 35 years were tested with a battery of neuropsychological tests (Word Association Test, Serial Verbal Learning, Weigl's test, Simple Reaction Times, Choice Continuous Reaction Time). Clinical profiles were evaluated by means of MMPI and WAIS (Wechsler Adult Intelligence Scale). Findings concerning cognitive processes show no significant differences between the two groups. Results suggest a correlation between clinical profiles and performances in acute patients, whereas in chronic subjects this correlation seems markedly reduced. Finally, chronicity (i.e. the length of illness) does not seem so be an important factor in determining consistent defects in neuropsychological performances.

Acute Disease↗
PubMed1976

The adolescent growth spurt of boys and girls of the Harpenden growth study.

Logistic curves have been fitted to the growth during puberty of the 55 boys and 35 girls of the Harpenden Growth Study who were measured every three months during puberty and thereafter until growth ceased. Very good fits were obtained for stature, sitting height, subischial leg length, biacromial and bi-iliac diameters from approximately six months after the beginning of the adolescent spurt. This beginning, called "take-off", was determined graphically as the point of minimum velocity. The total height gained from take-off point to cessation of growth averaged 28 cm in boys and 25 cm in girls with standard deviations of about 4 cm. The adult sex difference in height was due much more to the later take-off in boys than to a greater male adolescent spurt. A sex difference in the spurt occurred in sitting height but not in leg length. Mean-constant curves for the four measurements are presented. In each measurement size at take-off and total adolescent gain were nearly independent, the average correlation coefficient being --0-2. The correlations between adolescent gains in different measurements averaged only 0-47, and between peak velocities of different measurements only 0-27. This implies considerable shape change at adolescence. In contrast the average correlation between ages at which the peak velocities were reached was 0-87. Ages at take-off, at peak velocity, and at menarche were independent of mature size, though correlated with percentage of adult size reached at the ages in question, a measure of somatic maturity. Relationships with the development of breasts, pubic hair and genitalia were examined; ages at take-off and at peak velocity correlated to the extent of 0-6 to 0-8 with ages of B2 and PH2 but both these parameters and also peak velocities were uncorrelated with the rapidity with which sex characters developed.

Adolescent↗
PubMedDate not supplied

Learning capacities during sleep: a preliminary study in a group of schizophrenic inpatients.

The relationship between sleep and learning processes is analysed in a sample of schizophrenic patients, starting from more recent hypotheses about the function of REM sleep in learning and memory processes. This is done by means of two experiments: in the first AA. evaluate the possibility to elicit a simple motor conditional reflex acquired during daytime in different sleep stages. With the second experiment daytime learning performances are evaluated with and without a reinforcement administered during REM sleep. Results for the first experiment underline a qualitative difference between REM and nREM sleep in a reflexological perspective. In nREM sleep the conditional response is better maintained than in REM sleep. The second experiment confirms the possibility to improve daytime learning performances after an additional presentation of learning material in REM. The joint study of sleep abnormalities and learning and cognitive impairment in schizophrenic patients is finally suggested.

Adolescent↗