Cortisol moderates the relationship between testosterone and aggression in delinquent male adolescents.

BACKGROUND: In animals, strong evidence exists for an association between testosterone and aggression. In humans, and particularly in children and adolescents, findings have been less consistent. Previous research has suggested that this may partly be due to moderating effects of other factors, e.g., hormones. This study aims to investigate the moderating effect of cortisol on the relationship between testosterone and subtypes of aggression in delinquent male adolescents. METHODS: Participants were 103 boys (mean age 13.7) referred to a delinquency diversion program. Testosterone and cortisol levels were determined from saliva samples collected during resting conditions and related to self-report scores on overt and covert aggression. RESULTS: Linear regression analyses revealed a significant interaction between cortisol and testosterone in relation to overt aggression, with a significant positive relationship between testosterone and overt aggression in subjects with low cortisol levels but not in subjects with high cortisol levels. Using the same model for covert aggression, no significant effects of testosterone, cortisol, or testosterone x cortisol interaction were found. CONCLUSIONS: These results indicate a moderating effect of cortisol on the relationship between testosterone and overt aggression in delinquent male adolescents. Implications and directions for future research are discussed.     

Wavefront aberration and its relationship to the accommodative stimulus-response function in myopic subjects.

BACKGROUND: Autorefractors are increasingly used in myopia research because they are convenient tools to investigate aspects of the accommodation response. The degree to which the autorefractor measures are affected by ocular aberrations has been highlighted by studies that have shown changes in aberration levels through different parts of the pupil and with accommodation. We have compared accommodative accuracy as measured with a Shin-Nippon SRW 5000 autorefractor with wavefront error as measured with a Hartmann-Shack wavefront sensor to investigate how factors such as accommodation demand, ocular aberrations, and pupil size can influence autorefractor measures. METHODS: Accommodation stimulus-response curves were determined (using negative lenses) for 30 young healthy subjects (20 myopic [-0.75 to -6.00 D] and 10 emmetropic). Accommodation levels ranged from 0 to 4 D in 1 D steps. Wavefront aberrations were also determined for the same accommodation levels using a Hartmann-Shack wavefront sensor for both the subjects' natural pupil sizes and for a 2.9-mm pupil. RESULTS: For all subjects, there was a consistent increase in negative spherical aberration with increases in accommodative stimulus. However, there was no consistent change in paraxial spherocylindrical refractive correction with accommodation stimulus. For the emmetropic subjects, accommodation error as measured with the autorefractor was statistically similar to the total spherocylindrical correction for the eye as estimated by the Hartmann-Shack wavefront sensor, but only for a 2.9-mm pupil (the pupil size utilized by the autorefractor). For the myopic subjects, accommodation error as measured with the autorefractor was statistically similar to the higher-order aberrations, but only when measured for a natural pupil size. CONCLUSIONS: The relationship between the accommodation accuracy as measured with the autorefractor and the total wavefront aberration as measured with a Hartmann-Shack wavefront sensor is largely influenced by the higher-order (fourth and above) aberration levels. For the emmetropic subjects, the errors measured by the two methods agree when adjusted to measure at similar pupil sizes. For the myopic subjects with similar pupil sizes, however, the Hartmann-Shack wavefront sensor underestimates the accommodation error at higher accommodation levels (2 to 4 D) compared with the autorefractor.     

Leukaemic mantle cell lymphoma with t(11;14) and trisomy 12 showing clinical features of state A0 B cell chronic lymphocytic leukaemia

The precise diagnosis of lymphoma usually requires the histological examination of lymph nodes or involved tissues. Mantle cell lymphoma is a form of intermediate grade non-Hodgkin's lymphoma in which typical morphological immunophenotypic and cytogenetic features have been recognised. A case of leukaemic mantle cell lymphoma with the characteristic reciprocal translocation t(11;14) together with trisomy 12, a chromosomal abnormality usually associated with B cell chronic lymphocytic leukaemia (CLL), is presented. This combination of cytogenetic abnormalities has not been reported previously. The lack of lymphadenopathy and hepatosplenomegaly in this patient is more in keeping with stage A0 CLL. This case demonstrates the close clinical and biological relationship between mantle cell lymphoma and CLL.     

The efficacy of sports vision practice and its role in clinical optometry*

For years it has been recognised that many sports place demands on vision and particular visual skills. There is much evidence to show that the correction of visual dysfunction such as ametropia and binocular and accommodative anomalies results in improved sporting performance for those sports. More controversial and of special interest is the suggestion that it is possible to train visual abilities of subjects who do not present with traditionally recognised functional disorders of vision. It has been proposed that sporting performance can be improved as a result of this training. However, this review found the evidence to be inconclusive. In addition, there are studies that suggest athletes have better visual abilities than non-athletes and good athletes have better abilities than less skilled athletes. However, it has not been determined whether these superior abilities are innate to the athlete or have developed through practice. A review of the available literature was unable to prove (or disprove) either of these proposals. However, there appears to be enough evidence to warrant further investigation of these questions, in order that the area of sports vision and vision training can be more fully understood. This will enable clinicians to take full advantage of the potential of sports vision practice to assist athletes. (Clin Exp Optom 1995; 78: 3: 98–105)     

Effect of prolonged ketamine exposure on cardiovascular physiology in pregnant and infant rhesus monkeys (Macaca mulatta).

Physiologic measurements in nonhuman primates usually are collected from animals that are chemically or physically restrained. Both types of restraint may affect the parameters measured, and those effects can vary with age. Heart rate, respiratory rate, oxygen saturation, expired CO2, blood pressure, temperature, blood glucose, hematocrit, and venous blood gasses were measured in rhesus monkeys that were either infused intravenously with ketamine for 24 h or were cage-housed and physically restrained for sample collection. The subjects were pregnant monkeys at gestational day 120 to 123, infants 5 to 6 d old, and infants 35 to 37 d old. Heart rate and blood pressure were lower in ketamine-treated monkeys than physically restrained monkeys. Heart rate was higher in infants than adults, whereas blood pressure was lower in infants. Respiratory rate was higher in infants than adults and higher in physically restrained infants than ketamine-sedated infants but was not affected by ketamine in pregnant adults. Hematocrit was decreased in older infants. In summary, both physical restraint and ketamine sedation altered several physiologic parameters in pregnant and infant rhesus macaques. Investigators should consider these effects when designing experiments and evaluating experimental outcomes in monkeys.