Biomedical subjects

A Scano

Publications and source records attributed to A Scano.

At least 19 recordsLinked to original sources

PubMed1999

Gender affects the pattern of neuroendocrine response to head-up tilt.

One of the major concerns in space medicine is post-mission postural hypotension. Since the beginning, most of the studies have been aimed at the identification of mechanical and neuroautonomic mechanisms within the cardiovascular system potentially involved in this phenomenon. Some gender differences in the cardiovascular reactivity to changing posture have been described so far, which still need better clarification. Moreover, the neuroendocrine contribution to postflight readaptation deserves more indepth studies. Sudden passive head-up tilting is considered to be a good simulation method for hemodynamic changes occurring during transition from 0xg to 1xg. The aim of this study was to verify whether cardiovascular or neuroendocrine changes occurring after sudden passive +70 degrees head-up tilt (HUT) became already evident within 10 min and were similar in healthy young-adult men and women.

Adaptation, Physiological↗

PubMed1998

Indirect evidence of CNS adrenergic pathways activation during spaceflight.

BACKGROUND: Microgravity causes cephalad fluid shift and compensatory mechanisms. Hormonal changes suggestive of peripheral sympathetic (catecholaminergic) nervous system activation have been recently found in astronauts during flight. Simulation studies showed increased perivascular sympathetic fiber density in the rat brain. HYPOTHESIS: Intracranial microcirculatory adaptations might also occur in astronauts, involving an increase in the turnover rate of catecholamines, i.e., norepinephrine (NE) and its precursor, Dopamine (DA). DA is known to inhibit prolactin (PRL) release and to enhance growth hormone (GH) secretion by the pituitary. Therefore, increased brain dopaminergic activity would result into lower circulating PRL concentrations. At the same time, plasma levels of GH and of its effector insulin-like growth factor-1 (IGF-1) would increase during flight. METHODS: Circulating cortisol (CS), PRL, GH and IGF-1 levels were measured 2 d preflight, inflight (4-5 d after launch) and on different days postflight in four astronauts involved in the Spacelab D-2 mission. RESULTS: No significant changes were found in CS concentrations. PRL decreased while GH and IGF-1 increased inflight (p < 0.05). After flight no statistically relevant hormonal changes were found with respect to preflight. CONCLUSION: The observed hormonal changes were consistent with the original hypothesis that spaceflight might activate CNS adrenergic pathways. They occurred in the absence of two typical markers of stress, namely CS and PRL increase, thus ruling out any non-specific effect of acute stress on the results. In agreement with the most recent results of real and simulated microgravity studies performed in both the experimental animal and in man, these data lend support to the hypothesis that the CNS adrenergic pathways are also activated in the human during spaceflight.

Adaptation, Physiological↗

PubMed1982

[Past and present medical and biological studies in Italy on microgravity].

Since 1957, Italian workers have been carrying out experiments on the physiological and pathological effects of the weightlessness encountered during space travel. Most of this work has been done at the Air Force Aviation Medicine Study and Research Centre, Rome, while other research has been conducted at the Department of Human Physiology, University of Milan. Various original devices (axis subgravitis tower, triaxial clinostats, etc.) have been devised and constructed to simulate partial and total weightlessness. They have been employed well ahead of actual space flights in investigations of the effects of weightlessness on vestibular function, sensory and muscle coordination, the position of the diaphragm and its adjacent viscera, locomotion, plant growth, rapid adaptation phenomena, etc. One experiment conducted during orbital flight was called Orbiting Frog Otolith. This investigated vestibular function under statis and dynamic conditions in the absence of weight. An Italian three-dimensional ballistocardiography experimental project will be conducted during the first Spacelab flight.

Electrocardiography↗

PubMed1982

Structural and functional changes in man accompanying the weightlessness in "Skylab" flights: a mathematical approach.

The present paper reports a kinetic analysis of changes of some physiological parameters, obtained from international literature, after changes in gravitational environment. The overall phenomenology of the adaptation to weightlessness is characterized by a rapid process followed by a slow one. The two processes show half time values differing by about five times. Also in the case of readaptation to gravity, after recovery on the Earth, two well resolved processes, showing different half time values, are observed. It is of interest to notice that the rate of response to weightlessness is lower than that to gravity. Of course, the half time values observed depend on the different physiological parameters considered. In any case, the experimental data suggest a general trend of many adaptive changes, that may all be described by a simple mathematical model.

Adaptation, Physiological↗

PubMed1982

Simple technique to evaluate on the ground the energetic expenditure of physical exercise carried out in weightlessness.

A simple method is described to evaluate the energetic expenditure of graded muscular exercises carried out on the ground in such a way as to approximate the state of space microgravity. Consumption of O2 measured at different rates of execution is shown as well as a tentative computation of the mechanical work on the basis of the accelerations impressed alternately on the mass of the trunk and upper limbs. The practicability of the method proposed under space conditions is pointed out; it does not require any ergometer, in fact, but only the fixing of the subject's feet to the floor of the vehicle.

Adult↗

PubMed1977

[The Spacelab program: a major gateway to biological and medical research].

The Spacelab programme will run for about 10 years starting from 1980. It is the outcome of scientific, technological and financial cooperation between NASA and ESA. The latter has got together a large laboratory which will be equipped in accordance with individual flight programmes. A large number of scientists are involved in the preparation of suitable and original research projects. The main features of the laboratory and its vector are described and a brief reference is made to main advances that have been gathered from previous medical and biological programmes. The essential aspects of the nine European programmes (one of which was put forward by Italy) accepted for the first flight are explained.

Biology↗

PubMed1976