Bidirectional responsiveness of the pituitary-adrenal system was examined in young adult (3-5 months) and old (24-26 months) male and female rats. In Experiment 1, an approach-avoidance conflict was created by exposing food- and water-deprived subjects to a flavored solution which had previously been paired with lithium chloride-induced illness in a conditioned taste aversion paradigm. Young and old males and young females elevated plasma corticosterone in response to deprivation; males showed a further elevation when reexposed to the solution, whereas young females did not. Old females did not exhibit a corticosterone elevation to deprivation or upon reexposure. In Experiment 2, water was restricted to a fixed period in the morning when corticosterone levels are typically low. Plasma corticosterone was measured before and after watering. Young and old males and young females reentrained their circadian corticosterone rhythm so that levels were elevated just prior to watering; consumption was followed by a drop in corticosterone. Old females failed to reentrain or to suppress corticosterone secretion upon drinking. These findings indicate that the lability of the pituitary-adrenal system is more markedly affected by senescence in females than in males.

Aging↗

PubMedDate not supplied

Carpal tunnel syndrome and occupation in U.S. Navy enlisted personnel.

The objectives of this study were to (a) describe demographic factors associated with high rates of carpal tunnel syndrome (CTS), cubital tunnel syndrome, and other neuritis of the arm and hand, and (2) identify the high-risk occupations associated with these disorders in the Navy. Computerized records of first hospitalizations of all active-duty Navy-enlisted personnel were searched for all cases of CTS, cubital tunnel syndrome, and other neuritis of the arm and hand (ICD-9 CM codes 354.0-354.9) during 1980-1988. There were 1039 first hospitalizations (including 493 cases of CTS) for all neuritis of the arm and hand in 4095708 person-years in men and 186 first hospitalizations (including 90 cases of CTS) in 365668 person-years in women. Incidence rates of hospitalized cases with CTS rose with age for both sexes. Rates in white women were approximately three times those in white men (p < .0001), but rates in black women were not significantly different from those in black men. Rates of cubital tunnel syndrome also increased with age in both sexes and were higher in white women than white men (p < .05). Occupations with significantly high standardized incidence ratios (p < .05) for CTS in men included aviation-support equipment technician, engineman, hull-maintenance technician, boatswain's mate, and machinist's mate. In women, occupations with significantly high standardized incidence ratios included boatswain's mate, engineman, hospital corpsman, ocean-systems technician, and personnelman. Several occupations for each sex had significantly high standardized incidence ratios for cubital tunnel syndrome, with high rates in hospital corpsmen of both sexes (p < .05). Gender and race differences according to occupation did not account for the occupations at highest risk. Further research is needed to determine the extent to which CTS and related disorders could be prevented by modifying the motions currently performed in occupations with the highest standardized incidence ratios.

Adolescent↗

PubMedDate not supplied

Arterial blood-gas analyses during electroconvulsive therapy in a parturient.

Arterial blood gases and vital signs were monitored in a patient receiving electroconvulsive therapy (ECT) during the third trimester of pregnancy. Alterations in blood pressure and heart rate were similar to those noted in prior studies. Pretreating with 100 percent oxygen (02) and assisting ventilation until return of adequate spontaneous respirations, prevented hypoxemia, significant hypercarbia, and cardiovascular changes. The administration of succinylcholine prevented the systemic manifestations of the electrically-induced seizure. One fetal arrhythmia occurred, apparently unrelated to changes in maternal Pa02, and resolved spontaneously. This technic of anesthesia would appear to be acceptable for ECT in the parturient.

Adult↗

PubMedDate not supplied

Performance parameters in children and adolescent athletes.

Success in sports, as measured by competitive performance, is dependent upon a number of significant mental and physical components. Somatotype, motor skills, age, nutritional status, physiology, psychology, training level, genetic endowment, and injury risk are the major independent variables influencing performance. Unfortunately, the data available in this area of sports medicine are not always reliable or allow interstudy comparisons. This article reviews the historical and current information used to predict human performance in sports at the childhood and adolescent level. Although mesomorphy, and to a lesser extent ectomorphy, are positively associated with enhanced performance, successful athletes tend to have or acquire somatotypes characteristic of individuals already successful in a particular sport. For the most part, motor skills are age (chronological) and gender dependent. In general, the efficiency of movement progressively improves throughout childhood and into early adolescence and is highly dependent on environmental influences. A lower anaerobic and aerobic capacity reduces performance in the child and adolescent. Nonetheless, regular training can favourably improve motor skills and physiological fitness parameters. The relationship between endurance performance and aerobic capacity, however, is not strong at any age during childhood. Performance levels are reduced if nutrition is inadequate. A number of mental factors such as aggression, spirit, and self-confidence are also related to sports performance, although their correlation is unclear at present. Performance is influenced by the effect of genetic factors on specific traits in 30 to 85% of cases. Risk factors that negatively impact on performance levels include a history of previous injury, excessive training schedules, decreased fitness endurance, joint looseness or tightness, and certain personality traits. It is suggested that sport performance may be optimised by the early identification of individuals with positive genetic and somatotypic markers and negative risk factors. Motor skill development and physiological parameters can then be maximised by using regular, non-excessive training protocols, sound nutrition patterns, a safe environment and protective gear. Further investigations in this important area of sports medicine are essential in order to more fully characterise those criteria essential for successful sports participation. In particular, such studies should be purely longitudinal and should control for multiple confounding factors operating at different times.

Adolescent↗