The female athlete.

Women's participation in sporting activities is now diverse with new opportunities arising yearly. As a result, care of the the female athlete's unique medical concerns has become an important challenge and issue to the primary care physician. The major focus when caring for the female athlete should be the diagnosis and treatment of the female athlete triad. The components of the triad--disordered eating, amenorrhea, and osteoporosis--can have serious implications for the health of the female athlete. Appropriate prevention and screening methods for early diagnosis of the female athlete triad require future study and improvement. Healthy pregnant, postpartum, and breastfeeding women can continue to maintain physical activity. Musculoskeletal injuries from sports are, in general, not gender specific but are more often sport specific. One exception is the increased prevalence of anterior cruciate ligament injuries occurring in women soccer and basketball players. The exact cause of this is unknown but is continuing to be investigated.

Influence of steroid injection on ligament healing in the rat.

The effect of a single local injection of long acting corticosteroid on the healing of acute rat medial collateral ligament injuries was studied. The medial collateral ligaments of 81 adult female rats were exposed surgically. In 32 rats, the ligament was transected sharply, the overlying muscle was closed, and a human equivalent dose of dexamethasone was injected under the muscle layer, bathing the injured ligament. The identical operation with no corticosteroid injection was done in 32 additional rats: in the remaining 17 animals, the incision was closed without ligament transection or injection. The rats were divided into 3 groups of 25. Each group consisted of 10 rats that were injected, 10 that were not injected, and 5 that underwent sham operations. One group was euthanized 6 days after surgery, 1 group after 10 days, and 1 group after 20 days. Histologic evaluation and biomechanical testing were performed for each subgroup. A cellular pathologist examined a smaller group of 6 rats (2 from each group) for histologic changes 40 days after surgery. No histologic differences were noted between the injected and noninjected ligaments 6, 10, or 20 days after injury. At 40 days, the injected specimens showed a slightly more mature crimp pattern than the noninjected specimens. Mechanical testing demonstrated no significant difference in ultimate load or ultimate stress between the injected and noninjected groups. There were no detrimental effects of a single dose administration of dexamethasone on the histologic appearance or biomechanical strength of healing rat medial collateral ligaments.

Effects of local injection of corticosteroids on the healing of ligaments. A follow-up report.

One hundred and one skeletally mature New Zealand White rabbits were used to study the long-term effects of a single injection of corticosteroid on the biomechanical, histological, and biochemical properties of ligament-healing. Two steroid doses were studied, as previously described. The injections were made into a fascial pocket immediately after transection of the ligament. The animals were killed forty-two and eighty-four days after the injury. In our previous investigation, in which we examined the early (inflammatory and proliferative) phases of ligament-healing, the specimens that had been injected with a dose of steroids equivalent to that given to humans demonstrated significantly inferior biomechanical properties and histological organization relative to controls that had not received an injection. In the current study, we examined the later (remodeling and maturation) phases of ligament-healing and found that the tensile strength (the ultimate stress) of the specimens that had been injected with the steroids returned to a value that was equal to that of the controls that had not received an injection; however, the peak load of the specimens that had been injected with steroids remained inferior to that of the controls. This was accompanied by a lag in the histological maturation.

Effects of a delayed steroid injection on ligament healing using a rabbit medial collateral ligament model.

Corticosteroids are known to inhibit collagen synthesis in vitro as well as having a deleterious effect on ligament healing when applied immediately following injury. An acute injection of betamethasone into a transected rabbit medial collateral ligament significantly impaired the biomechanical and histological properties compared to non-injected transected ligaments. Differences in mechanical, histological and biochemical properties were observed up to 3 months following injury and an acute steroid injection. The present study explored the effects of a corticosteroid (betamethasone) injection 7 days following the initial injury. Biomechanical and histomorphometric analyses were carried determine if the previously observed deleterious effects of a corticosteroid injection immediately following injury can be linked to an interference in the inflammatory phase of healing due to the presence of the corticosteroid.

The management of dog bites and dog bite infections to the hand.

Dog bites account for approximately one of 200 emergency room visits. The majority of bites are from dogs known to the victim. Due to the numerous small compartments and the thin covering of soft tissue over the bones and joints, bite wounds to the hand are more likely to become infected that are bites to the arm, leg, or face. Improper management can result in significant morbidity and prolonged treatment. This article discusses the microbiology of dog bite wounds, antibiotic selection, and proper wound management.

Healing characteristics of a type I collagenous structure treated with corticosteroids.

One hundred twenty-eight skeletally mature New Zealand White rabbits were used to study the effect of a single corticosteroid injection on the biomechanical, biochemical, and histologic aspects of ligamentous healing. Two steroid dosages were used. The amount of the low-dose steroid was calculated by determining the corticosteroid concentration at which fibroblastic synthesis of collagen was inhibited in vitro. A human equivalent dose of betamethasone was used as the high-dose steroid injection. These two steroid doses and a saline control were injected around a transected medial collateral ligament. At 10 days all groups showed significantly inferior biomechanical properties relative to noninjected controls. By 3 weeks the human equivalent steroid dose group continued to demonstrate significantly inferior properties. Histologic and biochemical analyses confirmed the biomechanical results. The clinical relevance of the study was that the delivery of a human equivalent steroid dose into an acutely injured ligament significantly impairs the healing process relative to a noninjected ligament at 10 days and at 3 weeks after injury. This implies that a corticosteroid-treated injured ligament may not be able to withstand the mechanical loads of early vigorous rehabilitation.

Tears of the anterior cruciate ligament: primary and secondary signs at MR imaging.

To investigate primary and secondary signs of anterior cruciate ligament (ACL) tear at magnetic resonance (MR) imaging, the authors retrospectively reviewed 103 MR imaging examinations obtained in 99 patients, the original interpretations of these examinations, clinical records, and arthroscopy reports. Fifty cases of arthroscopy-documented complete ACL tear were included. The primary signs of ACL tear (ie, abnormal ACL morphologic features or signal intensity) had respective sensitivity and specificity values of 96% (48 of 50 examinations) and 94% (50 of 53) on sagittal images and 92% (46 of 50) and 83% (43 of 52) on coronal images. As a secondary sign of ACL tear, bone bruise involving the lateral compartment of the knee was found in 40% (20 of 50) of cases of ACL tear and in 4% (2 of 53) of cases of normal ACL. The mean curvature of the posterior cruciate ligament was increased (0.40 vs 0.27; P < .0001) in cases of ACL tear. An abnormal appearance of the ACL on sagittal images remains the single most sensitive and specific sign of ACL tear.

Amino Acid sequence of a novel calmodulin from the unicellular alga chlamydomonas.

An amino acid sequence for a Chlamydomonas calmodulin has been elucidated with emphasis on the characterization of differences that are unique to Chlamydomonas and Dictyostelium calmodulin. While the concentration of calmodulin required for half-maximal activation of plant NAD kinase varies among vertebrate, higher plant, algal, and slime mold calmodulins, only calmodulins from the unicellular alga Chlamydomonas and the slime mold Dictyostelium show increased maximal activation of NAD kinase (Roberts, Burgess, Watterson 1984 Plant Physiol 75: 796-798; Marshak, Clarke, Roberts, Watterson 1984 Biochemistry 23: 2891-2899). The same preparations of calmodulin do not show major differences in phosphodiesterase or myosin light chain kinase activator activity.We report here that a Chlamydomonas calmodulin has four primary structural features similar to Dictyostelium that are not found in other calmodulins characterized to date: an altered carboxy terminus including a novel 11-residue extension for Chlamydomonas calmodulin, unique residues at positions 81 and 118, and an unmethylated lysine at position 115. The only amino acid sequence identity unique to Chlamydomonas and Dictyostelium calmodulin is the presence of a lysine at position 115 instead of a trimethyllysine. These studies indicate that the methylation state of lysine 115 may be important in the maximal NAD kinase activator activity of calmodulin and support the concept that calmodulin has multiple functional domains in addition to multiple structural domains.

Determination of dexamethasone and corticosterone half-lives in male broilers.

Normal broiler males were used in a series of experiments to determine the rate of disappearance of dexamethasone, a synthetic corticoid, and corticosterone, the quantitatively most important glucocorticoid in the bird. Determination of the half-life (T1/2) of these compounds following an intravenous bolus injection was by high performance liquid chromatography. Half-lives for dexamethasone and corticosterone were found to be 36 and 22 min, respectively. The slower rate of disappearance from the blood may help to explain the ability of dexamethasone to overcome some of the problems associated with hyperthermic stress in birds. This method of quantitating exogenously administered steroids is applicable not only to basic research but also to analyses by inspection and regulatory agencies.