Management of sports-induced skin wounds

Skin wounds are common in sports but are rarely documented by the certified athletic trainer. The literature is unclear about wound types, and none of the articles reviewed reported frequencies. The purpose of this paper is to discuss the frequency of common athletic skin wounds and their specific management. Management of skin wounds can sometimes be problematic. Hydrogen peroxide has been used on wounds since 1947, yet some researchers report that hydrogen peroxide and iodophor solution can delay or interfere with wound healing, or cause damage to the wounded area if use is intense and prolonged. Occlusive dressings have been reported to have considerable advantage in maintaining a moist wound bed and in decreasing healing time. Infection rates beneath occlusive dressings, however, are similar to those associated with other types of dressings. Complications to wounds, with or without the use of occlusive dressings, such as keloids and seborrheic dermatitis, occur in low frequencies. Due to a lack of specific information about sports-induced skin wounds and their management, we recommend that standardized documentation for common wounds be developed along with further study of techniques for management.     

The Influence of Dirithromycin on the Pharmacokinetics of Cyclosporine in Healthy Subjects and in Renal Transplant Patients

The effect of a standard regimen of the investigational macrolide antibiotic, dirithromycin, on the single-dose kinetics of orally administered cyclosporine (CSA) was investigated in healthy young males and on the steady-state disposition kinetics of cyclosporine in a panel of renal transplant patients. Eight male volunteers participated after giving informed consent. CSA was administered in three single doses (15 mg kg(minus sign1) p.o. each) in each of three phases: (1) prior to a 14-day regimen of dirithromycin; (2) at the end of a 14-day regimen of dirithromycin (500 mg p.o. qAM); and (3) 2 weeks after the last dose of a 14-day regimen of dirithromycin. Pharmacokinetic parameters of CSA were estimated, and the differences among treatments were assessed by analysis of variation. No significant differences among treatment (phase) means were detected (p < 0.05). We conclude that a typical 14-day regimen of dirithromycin failed to alter the disposition kinetics of CSA when taken orally healthy young adult males. The effect of a standard regimen of dirithromycin on the steady-state disposition kinetics of orally administered CSA was investigated in a panel of 15 stable renal transplant patients. Pharmacokinetic parameters for CSA were evaluated prior to, during, and 2 weeks after discontinuing a 14-day (500 mg day(minus sign1)) oral regimen of dirithromycin. Dirithromycin elicited small but significant changes in the following parameters: C(av) was increased by 16% during dirithromycin treatment, and the changes in normalized C(av) were comparable. Likewise, C(SS,min) and normalized C(SS,min) were increased by 19% and 20%, respectively, during dirithromycin treatment. CSA oral clearance, CL/F(SS), decreased by 17% during dirithromycin treatment. C(SS,max) and normalized C(SS,max) were increased by 13% and 17%, respectively, during dirithromycin treatment but were not significantly different from those either before or after dirithromycin. The magnitude of the pharmacokinetic changes for CSA during dirithromycin treatment (<15% in normal subjects and 15--20% in renal transplant patients) when considered in the context of the therapeutic range of cyclosporine concentrations was relatively small, and not likely to warrant special attention to the dosing of CSA in such patients beyond routine whole-blood CSA and serum creatinine monitoring.     

Immunocytochemical localization of NaCh6 in cultured spinal cord astrocytes

The expression of the alpha-subunit of voltage-gated sodium channel 6 (NaCh6) was examined in cultures of astrocytes from E18 rat spinal cord by using an antibody specific for NaCh6. Stellate cells with processes and flat, pancake-like astrocytes are the two morphological types predominantly present in these cultures. The antibody to NaCh6 labeled clusters at the cell body and along the length of the processes in stellate, process-bearing cells. Weak staining was observed in the flat, pancake-like astrocytes. Together with previous studies (Black et al., Mol Brain Res 23:235-245, 1994, Glia 14:133-144, 1995) that show that stellate cells express NaChs II and III (but not NaCh I) and flat cells express NaCh II, these results support the conclusions that there are different patterns of sodium channel expression between flat and stellate astrocytes and that multiple channel isoforms are expressed within the same cell. This study also suggests that NaCh6 may contribute to the electrical properties found in stellate astrocytes.     

Buprenorphine and naloxone combinations: the effects of three dose ratios in morphine-stabilized, opiate-dependent volunteers

Sublingual buprenorphine is a promising new treatment for opiate dependence, but its opioid agonist effects pose a risk for parenteral abuse. A formulation combining buprenorphine with the opiate antagonist naloxone could discourage such abuse. The effects of three intravenous (IV) buprenorphine and naloxone combinations on agonist effects and withdrawal signs and symptoms were examined in 12 opiate-dependent subjects. Following stabilization on a daily dose of 60 mg morphine intramuscularly, subjects were challenged with IV doses of buprenorphine alone (2 mg) or in combination with naloxone in ratios of 2:1, 4:1, and 8:1 (1, 0.5, or 0.25 mg naloxone), morphine alone (15 mg) or placebo. Buprenorphine alone did not precipitate withdrawal and had agonist effects similar to morphine. A naloxone dose-dependent increase in opiate withdrawal signs and symptoms and a decrease in opioid agonist effects occurred after all drug combinations. Buprenorphine with naloxone in ratios of 2:1 and 4:1 produced moderate to high increases in global opiate withdrawal, bad drug effect, and sickness. These dose ratios also decreased the pleasurable effects and estimated street value of buprenorphine, thereby suggesting a low abuse liability. The dose ratio of 8:1 produced only mild withdrawal symptoms. Dose combinations at 2:1 and 4:1 ratios may be useful in treating opiate dependence. Received: 9 February 1998/Final version: 8 May 1998     

Marijuana,alcohol, and combined drug effects on the time course of glare recovery

The time course of light adaptation after intense light exposure is significantly delayed by alcohol, marijuana, and a combined dose of alcohol and marijuana. These effects were found in a double blind experiment, using 10 subjects. The experimental treatements were placebo, 0.75 ml/kg of 95% ethanol, 8 and 15 mg of ⁹ tetrahydrocannabinol (THC), and 0.75 ml/kg of 95% ethanol together with 15 mg of THC. The marijuana-induced delay in recovery is doserelated. Both drugs produce delayed recovery for at least 2 h after drug ingestion. The combined alcohol and marijuana treatment produces little more than the effect produced by either drug alone, suggesting some antagonism between the drugs — a suggestion supported by a significantly lower blood alcohol level for the alcohol dose when combined with marijuana than when taken alone.     

Cell Survival in the Uncrossed Projection of the Mammalian Retina is Independent of Birthdate

Naturally occurring cell loss in the retinal ganglion cell population of one eye can be interrupted by removal of the other eye in newborn rodents. Many of the rescued retinal ganglion cells which project ipsilaterally reside in the nasal retina, that part of the retina normally giving rise to primarily crossed optic axons. Their naturally occurring elimination has been attributed to their hypothesized late neurogenesis and the consequent delayed time of arrival of their axons in the target visual nuclei, thereby placing them at a competitive disadvantage with other, early arriving, optic axons. By combining the technique of tritiated thymidine autoradiography with the retrograde axonal transport of horseradish peroxidase in rats that had been enucleated on the day of birth, we report here that rescued cells in the nasal retina which project ipsilaterally are generated at the same time as their neighbours in the temporal retina. Time of genesis does not distinguish them; consequently, their axons should not differ in their arrival times within the target visual nuclei. Since their only obvious anomaly is one of pathway choice at the optic chiasm, their place of arrival, rather than their time, may ultimately determine their naturally occurring elimination.