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Biomedical subjects

A Dal Monte

Publications and source records attributed to A Dal Monte.

At least 19 recordsLinked to original sources
PubMed1997

Anaerobic contribution to the time to exhaustion at the minimal exercise intensity at which maximal oxygen uptake occurs in elite cyclists, kayakists and swimmers.

Using 23 elite male athletes (8 cyclists, 7 kayakists, and 8 swimmers), the contribution of the anaerobic energy system to the time to exhaustion (t(lim)) at the minimal exercise intensity (speed or power) at which maximal oxygen uptake (VO2max) occurs (IVO2max) was assessed by analysing the relationship between the t(lim) and the accumulated oxygen deficit (AOD). After 10-min warming up at 60% of VO2max, the exercise intensity was increased so that each subject reached his IVO2max in 30 s and then continued at that level until he was exhausted. Pre-tests included a continuous incremental test with 2 min steps for determining the IVO2max and a series of 5-min submaximal intensities to collect the data that would allow the estimation of the energy expenditure at IVO2max. The AOD for the t(lim) exercise was calculated as the difference between the above estimation and the accumulated oxygen uptake. The mean percentage value of energy expenditure covered by anaerobic metabolism was 15.2 [(SD 6)%, range 8.9-24.1] with significant differences between swimmers and kayakists (16.8% vs 11.5%, P < or = 0.05) and cyclists and kayakists (16.4% vs 11.5%, P < or = 0.05). Absolute AOD values ranged from 26.4 ml.kg-1 to 83.6 ml.kg-1 with a mean value of 45.9 (SD 18) ml.kg-1. Considering all the subjects, the t(lim) was found to have a positive and significant correlation with AOD (r = 0.62, P < or = 0.05), and a negative and significant correlation with VO2max (r = -0.46, P < or = 0.05). The data would suggest that the contribution of anaerobic processes during exercise performed at IVO2max should not be ignored when t(lim) is used as a supplementary parameter to evaluate specific adaptation of athletes.

Adult↗
PubMed1994

A new respiratory valve system for measuring oxygen uptake during swimming.

We describe a new respiratory valve system with minimal dead space, which allows measurement of ventilation and oxygen uptake during swimming. The device offers considerable advantages in efficiency and accuracy over current equipment, and can be used in conjunction either with a miniaturized telemetry system for oxygen uptake measurement or with a conventional system. The valve has a low airflow resistance, a small dead space (15 ml), and an electrically operating, closed-circuit pump to remove excess water from the expiratory tube. The external form and the buoyancy of the valve have been hydrostatically and hydrodynamically designed to reduce drag and to ensure a correct mass in the water. To obtain this result a very sophisticated material, carbon fibre, has been utilized. Our studies showed that this respiratory system is ideal for obtaining valid and reliable values of oxygen uptake during swimming, even at high speed and in endurance swimming tests.

Air Pressure↗
PubMed1993

Nedocromil sodium in the prevention of exercise-induced bronchospasm in athletes with asthma.

The aim of this study was to determine the efficacy of nedocromil sodium in the prevention of exercise-induced bronchospasm (EIB) in 13 top athletes affected by bronchial asthma. At a dose of 4 mg the drug significantly reduced the fall in FEV1 compared with placebo but not with respect to basal values. In 9 athletes, 4 mg nedocromil sodium produced a good protective effect and reduced the mean fall in FEV1 to 4% with respect to baseline values, while in the remaining 4 subjects, the protective effect was not satisfactory. In these 4 "non responders" 6 mg nedocromil was effective, and in 2 cases induced prolonged bronchodilatation. In conclusion, the effect of nedocromil sodium in the prevention of EIB may be dose-dependent in relation to the degree of bronchial hyperreactivity or to interference of other factors.

Administration, Inhalation↗
PubMed1987

Relationship between the efficiency of muscular work during jumping and the energetics of running.

The running economy of seventeen athletes was studied during running at a low speed (3.3 m X s-1) on a motor-driven treadmill. The net energetic cost during running expressed in kJ X kg-1 X km-1 was on average 4.06. As expected, a positive relationship was found between the energetic cost and the percentage of fast twitch fibres (r = 0.60, n = 17, p less than 0.01). In addition, the mechanical efficiency during two different series of jumps performed with and without prestretch was measured in thirteen subjects. The effect of prestretch on muscle economy was represented by the ratio between the efficiency of muscular work performed during prestretch jumps and the corresponding value calculated in no prestretch conditions. This ratio demonstrated a statistically significant relationship with energy expenditure during running (r = -0.66, n = 13, P less than 0.01), suggesting that the elastic behaviour of leg extensor muscles is similar in running and jumping if the speeds of muscular contraction during eccentric and concentric work are of similar magnitudes.

Adult↗
PubMed1987

The effect of pre-stretch on mechanical efficiency of human skeletal muscle.

The mechanical efficiency of positive work was studied in six subjects performing three different types of exercises. On the first occasion the subjects ran on a motor-driven treadmill at 3.33 m s-1; the second and the third exercises consisted of performing rhythmical vertical jumps for 1 min both in rebound (RJ) and no-rebound (NRJ) conditions. The mechanical efficiency calculated in NRJ, which reflects only the conversion of biochemical energy into mechanical work, was found to be lower than the corresponding observation in RJ, 17.2 vs. 27.8% (P less than 0.001), respectively. These differences could not be explained by only the storage and recoil of elastic energy occurring in RJ compared with NRJ. The calculated extra work delivered 'free' was greater than the potential elastic energy which could be stored within the leg extensor muscles (187 vs. 124 J for each jump, P less than 0.05). It is likely that other factors might be responsible for the extra work found in NRJ. It was suggested that the difference in the length of time to perform positive work between a simple shortening contraction and a stretch-shortening muscular activity could be also responsible for the enhanced efficiency observed in RJ. This suggestion was supported by the high relationship (P less than 0.001) found between the time to perform positive work and the mechanical efficiency measured in jumping and estimated during running.

Adult↗
PubMed1987

Congenital proximal radio-ulnar synostosis: clinical and anatomical features.

A new radiographic classification is proposed based on a study of 31 cases of congenital proximal radio-ulnar synostosis in which close correlation was observed between the clinical and radiographic pictures. The authors attempt to clarify some aspects of the pathogenesis of this rare disease.

Child, Preschool↗
PubMed1985

The relationship of maximal alactacid anaerobic power to somatotype in trained subjects.

The purpose of the present study was to investigate the relationship between somatotype components and maximal alactacid anaerobic power (MAAP) in trained subjects. The somatotype components (endomorphy: means = 2.66, S.D. = +/- 0.78; mesomorphy: means = 5.45, S.D. = +/- 1.12; ectomorphy: means = 2.46, S.D. = +/- 0.88) and total MAAP were measured in 40 male fencers (aged, means 21.79, S.D. = +/- 3.97) in order to determine the correlations. The results did not show any correlations between the parameters. It can be concluded that the MAAP of an individual does not depend on the somatotype; but it may also be assumed that MAAP show changes with the percentage of fibre type, enzymatic activity in these fibres involved by large muscle groups which are relatively related to musculo-skeletal development (second component of somatotype) and neuro-muscular properties of the subjects, all having a genetic basis.

Adolescent↗
PubMed1985

Long term results of triradiate osteotomy of the pelvis. A follow-up study of 26 hips.

The authors reviewed 26 hips in 21 patients treated by triple osteotomy of the pelvis for the sequelae of congenital dysplasia or congenital dislocation of the hip. The minimum follow-up was 3 years, maximum 6 years. The clinical condition remained constant over this period. Pain, if present before operation, was either improved or disappeared. The Trendelenburg limp was either unchanged or improved. Reduction of range of hip movement was very rare. There was 0.5 cms lengthening of the leg compared with the pre-operative state. The post-operative radiographic parameters were unchanged over the follow-up period. These included the acetabular roof angle (C.E. angle), Hilgenreiner's roof angle, the neck/shaft angle, and anterior coverage of the femoral head. In about one third of the cases, however, there was deterioration in centralization.

Adolescent↗
PubMed1984

The influence of extra load on the mechanical behavior of skeletal muscle.

Eleven international jumpers and throwers engaged in year round training were divided into experimental (n = 6) and control (n = 5) groups. The experimental group was tested before and after a 3 weeks simulated hypergravity period, and again 4 weeks after the hypergravity period. The high gravity condition was created by wearing a vest weighing about 13% of the subjects body weight. The vest was worn from morning to evening including the training sessions, and only removed during sleep. The daily training of all subjects consisted of classical weight training and jumping drills. No changes in the ordinary training program were allowed in the experimental group, except for the use of the vest. Vertical jumps, drop jumps and a 15 s continuous jumping test were used to measure the explosive power characteristics of the subjects. After the hypergravity period the experimental subjects demonstrated significant (5-10%, P less than 0.05-0.01) improvements in most of the variables studied: however, 4 weeks after cessation of the high gravity period they tended to return towards the starting values. No changes were observed in the results of the control group. The improvement observed in the experimental subjects was explained as fast adaptation to the simulated high gravity field. It is suggested that adaptation had occurred both in neuromuscular functions and in metabolic processes.

Adult↗
PubMed1984

Trochanteroplasty in the treatment of infantile septic arthritis of the hip.

The aim of the present contribution is to explore the possible surgical solution of the problem of dislocation of the hip secondary to infantile septic arthritis, particularly in the form in which the femoral head is totally destroyed. The operation of trochanteroplasty is based on transposing the intact epiphysis of the great trochanter to act as a new femoral head and subsequently restoring the correct anatomical alignment by a trochanteric adduction osteotomy. Sixteen cases so treated over the 11 year period from 1969 to 1980 are reported.

Acetabulum↗