Testosterone reactivity to competition and competitive endurance in men and women.

Transient shifts in testosterone occur during competition and are thought to positively influence dominance behavior aimed at enhancing social status. However, individual differences in testosterone reactivity to status contests have not been well-studied in relation to real-time expressions of competitive behavior among men and women. This research tests the association between changes in endogenous testosterone levels during competition and performance in terms of competitive endurance. Participant sex, social presence, and relative status outcomes (e.g., winning vs. losing) are tested as moderators of this relationship. In two studies, men and women (total N = 398) competed in the competitive will task (timed weight-holding) either individually or in the presence of an opponent (Study 1) or as a team with and without the presence of a competitor team (Study 2). Results showed a positive relationship between testosterone reactivity and performance for men, particularly those who won or ranked highest among their group - with increasing testosterone predicting better performance and decreasing testosterone predicting worse performance. For women, the effect only emerged among individuals who competed in dyads and lost. In Study 2, an exploratory mediation analysis revealed that individual differences in trait dominance predicted both testosterone reactivity to competition and task performance, with testosterone reactivity (moderated by sex and status outcome) partially explaining the direct relationship between dominance-related traits and behavior. Our goal was to examine testosterone reactivity in relation to real-time competitive effort and highlight the potential role of this relationship in explaining how individual differences in trait dominance produce competitive behavior.

Contaminated wounds: infection rates with subcutaneous sutures.

STUDY OBJECTIVE: To determine whether buried absorbable subcutaneous sutures (BASS) increase the infection rate in irrigated contaminated wounds. METHODS: This was a randomized, prospective trial in a rat model, with the histologist blinded to treatment group. A single 2-cm dorsal incision was made on each of 30 anesthetized 250-g Sprague-Dawley rats and inoculated with approximately 10(8) organisms of Staphylococcus aureus. After irrigation, 15 wounds were closed with running 4-0 nylon transdermal sutures, and 15 were closed with three interrupted 4-0 coated polyglactin 910 (Vicryl) subcuticular sutures (BASS) and running 4-0 nylon transdermal sutures. On day 7, wounds were scored on a scale of 0 to 3 in six categories: inflammatory infiltrates, fibroplasia and capillary proliferation, necrosis, exudates, giant cells, and edema. The possible range for the cumulative wound score was 0 (no inflammation) to 18 (severe inflammation and infection). RESULTS: The median total wound score in wounds closed with BASS was 14 (range, 7 to 16); it was 8 (range, 5 to 15) for wounds closed without BASS (P = .0004). The subscores for inflammation, necrosis, exudate, and edema were also significantly higher in wounds closed with BASS. CONCLUSION: BASS increase the infection rate and the degree of inflammation in contaminated wounds, despite through irrigation.

Enhanced intravenous urography in renal trauma with low-dose dopamine.

Intravenous pyelography is the standard first-line investigation for suspected renal trauma. A faint, and/or delayed visualization, or nonvisualization of the damaged renal unit is not uncommon. Low-dose dopamine (3 micrograms/kg/min) increases renal blood flow without deleterious side effects. An experimental rat model was developed to evaluate the effects of low-dose dopamine on intravenous pyelograms in animals with unilateral renal trauma. A consistent and significant improvement in the visualization of the injured kidney was noted in the dopamine-treated animals compared with controls that received equivalent volumes of normal saline.

Intermittent hydronephrosis: a diagnostic challenge.

Intermittent hydronephrosis is a difficult condition to diagnose because of the mild degree of dilatation encountered in imaging studies. The condition nevertheless is disabling and attempts to reach a precise diagnosis include diuretic excretory urography, ultrasonography and renal scans. The delayed double-peak pattern seen on 99mtechnetium-diethylenetriaminepentaacetic acid diuretic renography shows how the ureteropelvic junction can become self-obstructing with forced diuresis. All patients who exhibited this sign eventually had frank obstruction and most exhibited an extrinsic component to the obstruction. The recognition of the double-peak pattern may become a useful adjunct in the early diagnosis of intermittent hydronephrosis.