Growth hormone and insulin-like growth factor I responses to moderate submaximal acute physical exercise in man: effects of octreotide, a somatostatin analogue, administration.

We evaluated growth hormone (GH) and insulin-like growth factor I (IGF-I) response to moderate submaximal acute short-term physical exercise under basal conditions and after the administration of octreotide, a somatostatin analogue (SA), in a double-blind, counter-balanced experimental protocol. Seven untrained male volunteers performed two identical exercise tests, each on a treadmill (2.5% slope) for 30 minutes (min) at 60% of VO2max. Before starting the exercise test all the subjects received a single administration of placebo or octreotide and vice versa at two different sessions. Plasma GH, IGF-I and lactate assays were evaluated before starting, during, at the end and in the recovery phase. In the placebo-treated group GH rose significantly both during exercise and recovery whereas no significant modifications in IGF-I levels were observed. SA administration inhibited the exercise-dependent GH secretion, which showed a small rise only during exercise and returned to basal levels during recovery. In the same group, IGF-I decreased significantly after exercise compared to basal values. The results suggest that 1) in our experimental conditions acute physical exercise at aerobic threshold does not modify IGF-I concentration 2) SA is able to inhibit the exercise-dependent GH secretion and to decrease post-exercise IGF-I concentration.

Physical exercise stimulates marked concomitant release of beta-endorphin and adrenocorticotropic hormone (ACTH) in peripheral blood in man.

ACTH and beta-endorphin have been evaluated by means of a specific and sensitive radioimmunoassay in athletes reaching a status of physical stress. A concomitant marked increase of these 2 peptides has been recorded. The implications of this finding lead to the conclusion that stress stimulates the synthesis of the common precursor (31 K) in the pituitary.

[Epidemiology of the most widespread bacterial infections and current trends in use of antibiotics]. / Epidemiologia delle più diffuse infezioni batteriche e tendenze attuali nel ricorso agli antibiotici.

The last decade has seen a greater use of broad spectrum antibiotics at the expense of those with limited spectrum. With this in mind, the trends in the commonest bacterial, respiratory, gastroenteric and urinary infections from 1963 to 1974 have been analysed with a view to identify correlations between epidemiology and trends in antibotic consumption. The epidemiological investigation was carried out on the INAM health institution assisted population, i.e. on a sample of more than thirty million subjects throughout the country. Diseases with prevalently Gram-positive aetiology (acute and chronic infections of the respiratory tract) and those with prevalently Gram-negative aetiology (infections of the urinary tract) were examined and the data obtained processed statistically. It is personally considered that study of this pathology over the last decade is not enough to explain the tendency to make use almost exclusively of broad spectrum antibiotics and the serious clinical, epidemiological and social implications deriving from the dissemination of multiresistant bacterial strains.

[Clinical and epidemiological repercussions of bacterial resistance]. / Riflessi clinici ed epidemiologici delle resistenze batteriche

Following the observation of a high percentage of bacterial resistance to antibiotics, the mechanisms of the establishment and transmission of such resistances on an extra-chromosomal basis (R factors) are examined in detail. After noting that the increased incidence and spread of bacterial strains resistant to chemotherapeutic substances and antibiotics is caused by the widespread use of antibiotics in the zootechnical field, the use of antimicrobic substances for food conservation, the increasing use of broad spectrum antibiotics and the rapid selection of resistant Gram-negative strains in hospitals, the clinical and epidemiological effects of antibiotic resistance in the Enterobacteriaceae are considered. The situation in Italy is looked at in particular where multiresistance to antibiotics promoted by R factors, already widespread in northern Italy, is being presently extended to southern Italy. It is hoped that physicians will realise the immediate and future epidemiological effects of the indiscriminate employment of broad spectrum antibiotics as this inevitably leads to the establishment of multiple resistance factors in Gram-negative bacterial populations.