Circulating insulin-like growth factor binding proteins in fish: Their identities and physiological regulation.

Insulin-like growth factor binding proteins (IGFBPs) play crucial roles in regulating the availability of IGFs to receptors and prolong the half-lives of IGFs. There are six IGFBPs present in the mammalian circulation with IGFBP-3 being most abundant. In mammals IGFBP-3 is the major carrier of circulating IGFs, facilitated by forming a ternary complex with IGF and an acid-labile subunit (ALS). IGFBP-1 is generally inhibitory to IGF action by preventing it from interacting with its receptors. In teleosts, the third-round of vertebrate whole genome duplication created paralogs of each IGFBP, except IGFBP-4. In the fish circulation, three major IGFBPs are typically detected at molecular ranges of 20-25, 28-32 and 40-50kDa. However, their identities are not well established. Three major circulating IGFBPs in Chinook salmon have been identified through protein purification and cDNA cloning. Salmon 28- and 22-kDa IGFBPs are co-orthologs of IGFBP-1, termed IGFBP-1a and -1b, respectively. They are induced under catabolic conditions such as stress and fasting but their responses are somewhat different, with IGFBP-1b being the most sensitive of the two. Cortisol stimulates production and secretion of these IGFBP-1 subtypes while, unlike in mammals, insulin may not be a primary suppressor. Salmon 41-kDa IGFBP, a major carrier of IGF-I, is not IGFBP-3, as might be expected extrapolating from mammals, but is in fact IGFBP-2b. Salmon IGFBP-2b levels in plasma are high when fish are fed, and GH treatment increases its circulating levels similar to mammalian IGFBP-3. These findings suggest that salmon IGFBP-2b acquired the role and regulation similar to mammalian IGFBP-3. Multiple replications of fish IGFBPs offer a unique opportunity to investigate molecular evolution of IGFBPs.

Teachback methodology: building global training capacity with a unique training-of-trainers course.

To meet the global demand for training assistance in tuberculosis (TB) and human immunodeficiency virus (HIV) infection, a systematic model was created to conduct training-of-trainers courses. The Teachback Methodology curriculum was created using adult learning principles and implemented by collaborating with partners to create training-of-trainers courses. A total of 42 courses were held in 18 countries, resulting in 901 participants being able to enhance their training skills. During training-of-trainers courses, the participants practice teaching a course. Trainers observe the participants' performance and provide feedback on training skills and accuracy of course content. The methodology can be integrated with TB and HIV courses to enhance training capacity and help build a competent workforce.

Un modèle systématique de cours de formation de formateurs a été créé afin de répondre à la demande mondiale d'assistance à l'enseignement en matière de tuberculose (TB) et du virus de l'immunodéficience humaine (VIH). Le cours de Teachback Methodology a été créé en s'appuyant sur les techniques d'apprentissage de l'adulte et mis en œuvre en collaboration avec des partenaires afin de créer des cours de formation de formateurs. Un total de 42 cours a été réalisé dans 18 pays, ce qui a permis à 901 participants d'améliorer leurs capacités de formateurs. Lors des cours de formation de formateurs, les participants simulent la tenue d'un cours. Les formateurs observent leurs performances et évaluent leurs capacités de formation et l'exactitude du contenu délivré. Cette méthode peut être intégrée aux cours relatifs à la TB et au VIH afin d'améliorer les capacités de formation et contribuer à créer une main d'œuvre compétente.

Con el propósito de satisfacer la demanda mundial de ayuda a la capacitación en materia de tuberculosis (TB) e infección por el virus de la inmunodeficiencia humana (VIH), se estableció un método sistemático de realización de los cursos de adiestramiento de los futuros capacitadores. El plan de estudios con el método demostrativo o de repetición (Teachback) se formuló con base en los principios de aprendizaje de los adultos y se puso en práctica en colaboración con otros asociados a fin de crear los cursos de formación de capacitadores. Se llevaron a cabo 42 cursos en 18 países, en los cuales participaron 901 personas con el fin de fortalecer sus aptitudes como capacitadores. Durante las formaciones los participantes practicaron la dictada de un curso. Los entrenadores observaban el desempeño de los participantes y aportaban comentarios sobre su aptitud docente y sobre la precisión del contenido del curso. El método se puede integrar a los cursos sobre TB e infección por el VIH, a fin de reforzar la capacidad pedagógica y contribuir a fortalecer la competencia de los profesionales.

Use of radiopharmaceuticals in diagnostic nuclear medicine in the United States: 1960-2010.

To reconstruct reliable nuclear medicine-related occupational radiation doses or doses received as patients from radiopharmaceuticals over the last five decades, the authors assessed which radiopharmaceuticals were used in different time periods, their relative frequency of use, and typical values of the administered activity. This paper presents data on the changing patterns of clinical use of radiopharmaceuticals and documents the range of activity administered to adult patients undergoing diagnostic nuclear medicine procedures in the U.S. between 1960 and 2010. Data are presented for 15 diagnostic imaging procedures that include thyroid scan and thyroid uptake; brain scan; brain blood flow; lung perfusion and ventilation; bone, liver, hepatobiliary, bone marrow, pancreas, and kidney scans; cardiac imaging procedures; tumor localization studies; localization of gastrointestinal bleeding; and non-imaging studies of blood volume and iron metabolism. Data on the relative use of radiopharmaceuticals were collected using key informant interviews and comprehensive literature reviews of typical administered activities of these diagnostic nuclear medicine studies. Responses of key informants on relative use of radiopharmaceuticals are in agreement with published literature. Results of this study will be used for retrospective reconstruction of occupational and personal medical radiation doses from diagnostic radiopharmaceuticals to members of the U.S. radiologic technologists' cohort and in reconstructing radiation doses from occupational or patient radiation exposures to other U.S. workers or patient populations.

Temperature effect on high salinity depuration of Vibrio vulnificus and V. parahaemolyticus from the Eastern oyster (Crassostrea virginica).

Vibrio vulnificus (Vv) and Vibrio parahaemolyticus (Vp) are opportunistic human pathogens naturally associated with the Eastern oyster Crassostrea virginica. The abundances of both pathogens in oysters are positively correlated with temperature, thus ingestion of raw oysters during the warm summer months is a risk factor for contracting illness from these bacteria. Current post-harvest processing (PHP) methods for elimination of these pathogens are expensive and kill the oyster, changing their organoleptic properties and making them less appealing to some consumers. High salinity has proven effective in reducing Vv numbers in the wild and our research aims at developing an indoor recirculating system to reduce pathogenic Vibrios while maintaining the taste and texture of live oysters. The goal of this study was to determine the influence of temperature on the efficacy of high salinity depuration. Vv was enumerated as most probable number (MPN) per gram of oyster tissue using the FDA-approved modified cellobiose polymyxin colistin (mCPC) protocol and with an alternative Vibrio specific media CHROMagar™ Vibrio (CaV). CaV was also used to quantify Vp. Oysters were held at 35 psu for 10 days at three temperatures: low (20°C), mid (22.5°C) and high (25°C). There was no difference in MPN/g of Vv between media; however more Vv isolates were obtained from mCPC than CaV. There was no significant effect of temperature on reduction of Vv or Vp throughout depuration but there was a tendency for low temperatures to be less effective than the higher ones. High salinity resulted in a significant decrease in Vv by day 3 and again by day 10, and a decrease in Vp by day 3. Oyster condition indices were maintained throughout depuration and mortality was low (4% across three trials). Overall these results support the use of mCPC for Vv enumeration and demonstrate the promise of high salinity depuration for PHP of the Eastern oyster. The trend for lower temperatures to be less effective is surprising and indicates a potential interaction between salinity and temperature that should be further investigated.

The science of rotator cuff tears: translating animal models to clinical recommendations using simulation analysis.

PURPOSE: The purpose of this article is to review basic science studies using various animal models for rotator cuff research and to describe structural, biomechanical, and functional changes to muscle following rotator cuff tears. The use of computational simulations to translate the findings from animal models to human scale is further detailed. METHODS: A comprehensive review was performed of the basic science literature describing the use of animal models and simulation analysis to examine muscle function following rotator cuff injury and repair in the ageing population. RESULTS: The findings from various studies of rotator cuff pathology emphasize the importance of preventing permanent muscular changes with detrimental results. In vivo muscle function, electromyography, and passive muscle-tendon unit properties were studied before and after supraspinatus tenotomy in a rodent rotator cuff injury model (acute vs chronic). Then, a series of simulation experiments were conducted using a validated computational human musculoskeletal shoulder model to assess both passive and active tension of rotator cuff repairs based on surgical positioning. CONCLUSION: Outcomes of rotator cuff repair may be improved by earlier surgical intervention, with lower surgical repair tensions and fewer electromyographic neuromuscular changes. An integrated approach of animal experiments, computer simulation analyses, and clinical studies may allow us to gain a fundamental understanding of the underlying pathology and interpret the results for clinical translation.

Intravitreal bevacizumab: safety of multiple doses from a single vial for consecutive patients.

OBJECTIVES: To report the incidence of endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor and the safety profile of multiple doses of bevacizumab from the same vial reused for multiple patients. DESIGN: Case series. SETTING: A private hospital in Hong Kong. PATIENTS: A systematic retrospective review of consecutive intravitreal anti-vascular endothelial growth factor injections between 5 June 2006 and 17 December 2010 at a single institute was conducted. Patients were identified from prospectively designed audit forms, and each patient's medical record was reviewed for any documented complications. Bevacizumab 1.25 mg/0.05 mL to 2.50 mg/0.1 mL was aspirated from the designated vial, with a maximum of 10 consecutive injections being aspirated from the same vial. The opened vial was then discarded without overnight storage. Ranibizumab was aspirated from the commercially available 1 mg/0.1 mL single-use vial. RESULTS: A total of 1655 intravitreal anti-vascular endothelial growth factor injections into 392 eyes of 383 patients were evaluated during the study period. There were 1184 bevacizumab injections and 471 ranibizumab injections. There was one case of suspected endophthalmitis after ranibizumab injection, though culture of the vitreous tap was negative. The point prevalence of endophthalmitis was 0.06% (1/1655) for the total number of injections: 0.21% (1/471) after ranibizumab, and 0% after bevacizumab. CONCLUSION: Although many centres aliquot multiple syringes from a single vial to be kept in a refrigerator for use, the current study shows that so long as proper sterile techniques are implemented, there were no cases of endophthalmitis from using the same vial, which was reused for a maximum of 10 consecutive injections. For intravitreal injection, bevacizumab costs approximately US$50 to US$100 per dose, as opposed to US$2000 per dose for ranibizumab. Sharing multiple doses of bevacizumab from a single vial can substantially reduce the cost of treatment.

Federal seafood safety response to the Deepwater Horizon oil spill.

Following the 2010 Deepwater Horizon oil spill, petroleum-related compounds and chemical dispersants were detected in the waters of the Gulf of Mexico. As a result, there was concern about the risk to human health through consumption of contaminated seafood in the region. Federal and Gulf Coast State agencies worked together on a sampling plan and analytical protocols to determine whether seafood was safe to eat and acceptable for sale in the marketplace. Sensory and chemical methods were used to measure polycyclic aromatic hydrocarbons (PAHs) and dispersant in >8,000 seafood specimens collected in federal waters of the Gulf. Overall, individual PAHs and the dispersant component dioctyl sodium sulfosuccinate were found in low concentrations or below the limits of quantitation. When detected, the concentrations were at least two orders of magnitude lower than the level of concern for human health risk. Once an area closed to fishing was free of visibly floating oil and all sensory and chemical results for the seafood species within an area met the criteria for reopening, that area was eligible to be reopened. On April 19, 2011 the area around the wellhead was the last area in federal waters to be reopened nearly 1 y after the spill began. However, as of November 9, 2011, some state waters off the Louisiana coast (Barataria Bay and the Delta region) remain closed to fishing.

Circulating salmon 28- and 22-kDa insulin-like growth factor binding proteins (IGFBPs) are co-orthologs of IGFBP-1.

Circulating insulin-like growth factor binding proteins (IGFBPs) play pivotal roles in stabilizing IGFs and regulating their availability to target tissues. In the teleost circulation, three major IGFBPs are typically detected by ligand blotting with molecular masses around 20-25, 28-32 and 40-45kDa. However, their identity is poorly established and often confused. We previously identified salmon 22- and 41-kDa forms as IGFBP-1 and -2b, respectively. In the present study, we cloned the cDNA of 28-kDa IGFBP from Chinook salmon (Oncorhynchus tshawytscha) as well as rainbow trout (Oncorhynchus mykiss) based on the partial N-terminal amino acid sequence of purified protein and identified it as an ortholog of IGFBP-1. Structural and phylogenetic analyses revealed that the 28-kDa IGFBP is more closely related to human IGFBP-1 and zebrafish IGFBP-1a than the previously identified salmon IGFBP-1 (i.e. 22-kDa IGFBP). We thus named salmon 28- and 22-kDa forms as IGFBP-1a and -1b, respectively. Salmon IGFBP-1a contains a potential PEST region involved in rapid protein turnover and phosphorylation sites typically found in mammalian IGFBP-1, although the PEST and phosphorylation scores are not as high as those of human IGFBP-1. There was a striking difference in tissue distribution patterns between subtypes; Salmon igfbp-1a was expressed in a variety of tissues while igfbp-1b was almost exclusively expressed in the liver, suggesting that IGFBP-1a has more local actions. Direct seawater exposure (osmotic stress) of Chinook salmon parr caused increases in both IGFBP-1s in plasma, while IGFBP-1b appeared to be more sensitive. The presence of two co-orthologs of IGFBP-1 in the circulation in salmon, and most likely in other teleosts, provides a good opportunity to investigate subfunction partitioning of duplicated IGFBP-1 during postnatal growth.

The pituitary-thyroid axis during the parr-smolt transformation of Coho salmon, Oncorhynchus kisutch: quantification of TSH ß mRNA, TSH, and thyroid hormones.

The objective of this investigation was to quantify pituitary thyroid stimulating hormone (TSH) ß mRNA, pituitary and plasma TSH and plasma thyroid hormone levels during the parr-smolt transformation of Coho salmon that occurs in spring from February to May. The status of the pituitary-thyroid axis was assessed using an RNase protection assay for pituitary TSH ß mRNA and radioimmunoassays for salmon pituitary and plasma TSH and thyroid hormones. TSH ß mRNA was highest during late winter (February) (4.9 pg/µg DNA) and gradually declined during spring (2.3 pg/µg DNA). In contrast, pituitary and plasma TSH levels showed a small, but statistically non-significant change during smoltification. Despite minimal change in plasma TSH levels, characteristically large increases in plasma T4 (January-3.3 ng/ml to April-10.2 ng/ml) and significant, but modest increases in plasma T3 (February-2.4 ng/ml to April-5.8 ng/ml) were observed. Regression analysis showed a significant positive relationship between plasma T4 and T3 and negative relationship between plasma T3 and pituitary TSH ß mRNA. However, all other relations were not significant. These data suggest a significant role for peripheral regulation (i.e. T4-T3 conversion, change in tissue sensitivity, hormone degradation rate) as well as evidence of central regulation via negative feedback at the level of the pituitary gland in regulation of thyroid activity in salmon. Furthermore, the increased thyroid sensitivity to TSH (shown previously), in the face of relatively constant plasma TSH levels, may be the major factor responsible for the increased thyroid activity observed during smoltification.

Circulating salmon 41-kDa insulin-like growth factor binding protein (IGFBP) is not IGFBP-3 but an IGFBP-2 subtype.

In vertebrates, most circulating insulin-like growth factor (IGF) is bound to multiple forms of IGF-binding proteins (IGFBPs) that differ both structurally and functionally. In mammals, the largest reservoir of IGF in the circulation comes from a large (150kDa) ternary complex comprised of IGF bound to IGFBP-3, which is bound to an acid label subunit (ALS), and this variant of IGFBP is regulated by growth hormone (GH) and feed intake. Although multiple variants of IGFBPs ranging from 20 to 50kDa have been found in fishes, no ternary complex is present and it has been assumed that the majority of circulating IGF is bound to fish IGFBP-3. Consistent with this assumption is previous work in salmon showing the presence of a 41-kDa IGFBP that is stimulated by GH, decreases with fasting and increases with feeding. However, the hypothesis that the salmon 41-kDa IGFBP is structurally homologous to mammalian IGFBP-3 has not been directly tested. To address this issue, we cloned cDNAs for several Chinook salmon IGFBPs, and found that the cDNA sequence of the 41-kDa IGFBP is most similar to that of mammalian IGFBP-2 and dissimilar to IGFBP-3. We found an additional IGFBP (termed IGFBP-2a) with high homology to mammalian IGFBP-2. These results demonstrate that salmon 41-kDa IGFBP is not IGFBP-3, but a paralog of IGFBP-2 (termed IGFBP-2b). Salmon IGFBP-2s are also unique in terms of having potential N-glycosylation sites and splice variants. Additional research on non-mammalian IGFBPs is needed to fully understand the molecular/functional evolution of the IGFBP family and the significance of the ternary complex in vertebrates.

Applications of BMI or BSI: Differences and Revisions According to Age and Height.

Validation of body-mass relationships requires a careful statistical analysis of data of normal weight individuals. BMI (ratio between body mass and square of body height) and BSI values (ratio between mass and cube of body height) have been calculated for 99 persons with ages between 1 day and 76 years. These BMI or BSI values have been used for least squares fits yielding mean BMI or BSI values, their variances (providing precision), and average deviations of individual BMI/BSI values from the BMI/BSI means. The latter allows limits to over- and underweight. For adults we found mean values of BSI of 12.36 and confirmed 21.7 for the mean BMI; but the BSI was 1.4 times more precise than the BMI. For children shorter than 1.3 m and younger than 8 years we found the BMI average of 15.9 and over-/underweight limits of 17.4/14.4 being significantly smaller than and incompatible with the recommended BMI values.

Postprandial changes in plasma growth hormone, insulin, insulin-like growth factor (IGF)-I, and IGF-binding proteins in coho salmon fasted for varying periods.

We examined postprandial changes in circulating growth hormone (GH), insulin, insulin-like growth factor (IGF)-I, and IGF-binding proteins (IGFBPs) in yearling coho salmon under different feeding regimes. Fish were initially fasted for 1 day, 1 wk, or 3 wk. Fasted fish were then fed, and blood was collected at 4-h intervals over 26 h. After the various periods of fasting, basal levels of insulin were relatively constant, whereas those of IGF-I, IGFBPs and GH changed in proportion to the duration of the fast. A single meal caused a rapid, large increase in the circulating insulin levels, but the degree of the increase was influenced by the fasting period. IGF-I showed a moderate increase 2 h after the meal but only in the regularly fed fish. Plasma levels of 41-kDa IGFBP were increased in all groups within 6 h after the single meal. The fasting period did not influence the response of 41-kDa IGFBP to the meal. IGFBP-1 and GH decreased after the meal to the same extent among groups regardless of the fasting period. The present study shows that insulin and IGF-I respond differently to long (weeks)- and short (hours)-term nutritional changes in salmon; insulin maintains its basal level but changes acutely in response to food intake, whereas IGF-I adjusts its basal levels to the long-term nutritional status and is less responsive to acute nutritional input. IGFBPs maintain their sensitivity to food intake, even after prolonged fasting, suggesting their critical role in the nutritional regulation of salmon growth.

Isolated tears of the anterior cruciate ligament: over 30-year follow-up of patients treated with arthrotomy and primary repair.

BACKGROUND: Over 30 years ago, Feagin and Curl reported on the diagnosis and treatment of "isolated" injuries of the anterior cruciate ligament (ACL). The purpose of this study was to evaluate the long-term results of the patients initially diagnosed with tears of the ACL, with special emphasis on those treated with primary repair. HYPOTHESIS: Long-term results are unsatisfactory for open evaluation and treatment of ACL injuries with or without primary repair. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Follow-up was available on 34 of the original 57 patients (60%) who had ACL tears on evaluation by arthrotomy. The average age at the index procedure was 20 years, and average follow-up was 32 (range, 29-36) years. Twenty-five of the 26 complete ACL tears were treated with primary repair. None of the 8 partial tears was repaired. Evaluations included the subjective and symptom ratings of the International Knee Documentation Committee (IKDC) evaluation form, Lysholm score, Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner activity scale, and SANE rating. RESULTS: For the IKDC subjective score, 18 of 34 patients rated their knees as normal or nearly normal. The Lysholm scores averaged 70.1 (range, 20-100). The average SANE rating at 5 years was 74.8 (range, 49-110), and the current SANE rating averaged 68.9 (range, 10-100). The overall KOOS rating averaged 68.6 (range, 26.4-100). The Tegner activity score was 3.7. There was little difference between patients with unrepaired partial tears and those who had primary repairs. CONCLUSION: At more than 30-year follow-up, patients have decreased activity levels and an equal mix of acceptable and unacceptable outcomes. We were unable to identify any predictive factors that correlated with the results; however, subsequent meniscal surgery did correlate with poor results. The results at greater than 30 years reinforce the 5-year results that showed unsatisfactory results after the open evaluation and treatment of ACL injuries with or without repair.

Knowledge, attitudes and risk perceptions about tuberculosis: US National Health Interview Survey.

BACKGROUND: Tuberculosis (TB) disproportionately affects the human immunodeficiency virus (HIV) infected, foreign-born, Black, Hispanic, American Indian/Alaska Native, Asian, homeless, incarcerated, alcoholic, diabetic or cancer patients, male, those aged >44 years, smokers and poor persons. METHODS: We present TB knowledge, attitudes and risk perceptions overall and for those experiencing TB disparities from the 2000-2005 US National Health Interview Survey (NHIS). RESULTS: A total of 32% of respondents said TB is curable; 44% correctly recognized that TB is transmitted by air. Persons with less knowledge about TB transmission were aged 18-24 years, alcohol abusers, educated <12 years, Hispanics or males. Persons less likely to say TB is curable were aged 18-44 years, smokers, HIV-tested, uninsured, alcohol abusers or homeless/incarcerated. Only 28% of foreign-born persons from Mexico/Central America/the Caribbean said TB was curable. CONCLUSIONS: Knowledge about TB transmission and curability was low among a representative US population. Renewed TB educational efforts are needed for all populations, but should be targeted to populations disproportionately affected, especially those who are HIV-infected, homeless/incarcerated, Black, alcohol abusers, uninsured or born in Mexico/Central America/the Caribbean.

The effect of predatory fish exudates on the ovipostional behaviour of three mosquito species: Culex quinquefasciatus, Aedes aegypti and Culex tarsalis.

Three mosquito species, Culex tarsalis Coquillett, Culex quinquefasciatus Say and Aedes aegypti L. (Diptera: Culicidae), were examined in laboratory binary choice experiments to investigate whether fish exudates from the mosquitofish, Gambusia affinis (Baird & Girard) (Cyprinodontiformes: Poecilliidae), deter oviposition and whether the responses of these mosquito species to fish exudates in oviposition sites are consistent with the risk of predation from fish experienced by each species in their respective natural breeding habitats. Culex tarsalis was deterred significantly from egg laying by the presence of fish exudates in oviposition cups, consistent with high levels of predation by fish in natural breeding sites. Egg laying by Cx quinquefasciatus was slightly reduced in water with fish exudates, but was not consistently deterred by water conditioned by mosquitofish, consistent with the species' relatively low risk of fish predation in natural habitats. Oviposition by container-breeding Ae. aegypti was not deterred by the presence of fish exudates in oviposition cups, consistent with a low risk of predation by fish in natural habitats.

Initial biomechanical properties of staple-anchor Achilles tendon allograft and interference screw bone-patellar tendon-bone autograft fixation for anterior cruciate ligament reconstruction in a cadaveric model.

PURPOSE: Anterior cruciate ligament (ACL) reconstruction is a common procedure that has a fairly high success rate. Despite such success, controversy exists with regard to fixation and graft type. The purpose of this study was to quantify the maximum load to failure for staple-anchor freeze-dried Achilles tendon allograft fixation compared with interference screw bone-pattelar tendon-bone autograft fixation at the time of insertion for ACL reconstruction. METHODS: Eleven pairs of cadaveric knees were prepared for ACL reconstruction by disarticulation before graft insertion. The tibia and femur were mounted separately onto an MTS machine and were loaded to failure in line with the tunnels. Femoral fixation for the allograft was provided by a staple anchor; tibial fixation was provided by a suture anchor. Titanium interference screws on the femoral and tibial sides provided autograft fixation. A paired t test was performed to compare mechanical testing results in the 2 groups. RESULTS: Mean maximum load to failure for the allograft was 58.7 N (range, 32.3 to 92.6 N) and 119.6 N (range, 82 to 165.9 N) for the femur and the tibia, respectively, compared with 228.2 N (range, 74.2 to 352 N) and 232.9 N (range, 65.1 to 553.1 N) for the autografts. This difference was statistically significant (P < .001) for femoral fixation, but it was not statistically significant for tibial fixation (P = .186). CONCLUSIONS: Soft tissue Achilles tendon allograft with staple fixation is a significantly weaker fixation construct when compared with autograft bone-patellar tendon-bone with interference screw fixation. CLINICAL RELEVANCE: This study shows significantly weaker fixation in the staple-alograft construct and yet this construct has had at least equivalent results over a 5-year time frame, indicating that rigid femoral fixation may not be a critical factor in long-term results.

Concussions in adolescent athletes.

A concussion is defined as a complex pathophysiologic process affecting the brain that is induced by traumatic biomechanical forces. Concussions are caused by a direct or indirect blow that leads to a graded set of syndromes characterized by functional rather than structural disturbances to the brain. Concussions are characterized by a wide variety of presenting symptoms, including loss of consciousness, amnesia, confusion, headache, and nausea. Concussions occur in patients participating in all levels of athletic activities, with most occurring in younger athletes. The evaluation of a patient with a concussion should include assessment of the airway, breathing, circulation, level of consciousness, orientation, memory, concentration, and neurologic function. Multiple grading scales and return to play guidelines have been published to assist the clinician in the treatment of patients with concussions. Diagnostic and treatment concerns include spinal cord injury, intracranial pathology, second impact syndrome, and long-term impairment of cognitive function. Computerized neuropsychologic testing is a new tool in the treatment of concussions. These tests measure memory, new learning, attention, and reaction time and should be used as an adjunct to other tools for clinical decision making. Published guidelines will assist in treatment decisions; however, it should be kept in mind that all concussions are unique injuries.

"Stingers" in adolescent athletes.

Brachial plexus injuries commonly occur in athletes participating in contact sports. The incidence of transitory brachial plexus injury is approximately 30% to 50% over the course of a high school, college, or professional football player's career. These injuries are called "stingers" or "burners" because of the associated tingling that occurs in the upper extremity after the injury. Brachial plexus injuries are poorly understood and sometimes are difficult to manage. Appropriate knowledge and understanding of these injuries along with prompt recognition, diagnosis, and treatment are essential for optimal care of the injured athlete and for the athlete's timely return to play. Most injuries occur by one of three mechanisms: traction, compression, or hyperextension and compression. Injuries are clinically classified as neurapraxia, neurapraxia/axonotmesis, and neurotmesis according to their symptomatology and the pattern of symptom resolution. Most injuries are either a neurapraxia or a neurapraxia/axonotmesis. Most athletes recover completely and can return to play after they are asymptomatic and have regained full sensation, strength, and range of motion. Protective equipment has been introduced to decrease the occurrence of stingers. Education of the athlete, the family, and coaches is important to help them to understand and to assist in managing these injuries.

Age-related loss of muscle mass and bone strength in mice is associated with a decline in physical activity and serum leptin.

The mechanisms underlying age-related loss of muscle and bone tissue are poorly understood but are thought to involve changes in sex hormone status, physical activity, and circulating levels of inflammatory cytokines. This study attempts to develop an animal model useful for evaluating these mechanisms in vivo. Male C57BL/6 mice were included for study at 3, 6, 12, 18, 24, and 29 months of age. Endocortical mineralizing surface, serum leptin, body weight, and percentage of body fat all increased between 6 and 12 months of age as activity level declined. Serum levels of the inflammatory marker IL-6 increased significantly after 12 months of age, following the observed increase in body weight and percent body fat. Hindlimb muscle mass declined significantly between 18 and 24 months of age, both absolutely and relative to total body mass, with a further decline ( approximately 15%) between 24 and 29 months. Loss of muscle mass after 18 months of age was accompanied by a significant increase in bone resorption, as indicated by serum pyridinoline cross-links, and a significant decrease in fat mass, serum leptin, bone strength, bone mineral density, and vertical cage activity. No significant changes in serum testosterone with aging were detected in the mice, as levels were essentially constant between 6 and 29 months. Our data show that mice lose a significant amount of muscle and bone tissue with age, and this loss of musculoskeletal tissue is accompanied by a drop in serum leptin and preceded by a significant decrease in physical activity.

Measurement of circulating salmon IGF binding protein-1: assay development, response to feeding ration and temperature, and relation to growth parameters.

Fish plasma/serum contains multiple IGF binding proteins (IGFBPs), although their identity and physiological regulation are poorly understood. In salmon plasma, at least three IGFBPs with molecular masses of 22, 28 and 41 kDa are detected by Western ligand blotting. The 22 kDa IGFBP has recently been identified as a homolog of mammalian IGFBP-1. In the present study, an RIA for salmon IGFBP-1 was established and regulation of IGFBP-1 by food intake and temperature, and changes in IGFBP-1 during smoltification, were examined. Purified IGFBP-1 from serum was used for as a standard, for tracer preparation and for antiserum production. Cross-linking (125)I-labelled IGFBP-1 with salmon IGF-I eliminated interference by IGFs. The RIA had little cross-reactivity with salmon 28 and 41 kDa IGFBPs (< 0.5%) and measured IGFBP-1 levels as low as 0.1 ng/ml. Fasted fish had significantly higher IGFBP-1 levels than fed fish (21.6 +/- 4.6 vs 3.0 +/- 2.2 ng/ml). Plasma IGFBP-1 was measured in individually tagged 1-year-old coho salmon reared for 10 weeks under four different feeding regimes as follows: high constant (2% body weight/day), medium constant (1% body weight/day), high variable (2% to 0.5% body weight/day) and medium variable (1% to 0.5% body weight/day). Fish fed with the high ration had lower IGFBP-1 levels than those fed with the medium ration. Circulating IGFBP-1 increased following a drop in feeding ration to 0.5% and returned to the basal levels when feeding ration was increased. Another group of coho salmon were reared for 9 weeks under different water temperatures (11 or 7 degrees C) and feeding rations (1.75, 1 or 0.5% body weight/day). Circulating IGFBP-1 levels were separated by temperature during the first 4 weeks; a combined effect of temperature and feeding ration was seen in week 7; only feeding ration influenced IGFBP-1 level thereafter. These results indicate that IGFBP-1 is responsive to moderate nutritional and temperature changes. There was a clear trend that circulating IGFBP-1 levels were negatively correlated with body weight, condition factor (body weight/body length(3) x 100), growth rates and circulating 41 kDa IGFBP levels but not IGF-I levels. During parr-smolt transformation of coho salmon, IGFBP-1 levels showed a transient peak in late April, which was opposite to the changes in condition factor. Together, these findings suggest that salmon IGFBP-1 is inhibitory to IGF action. In addition, IGFBP-1 responds to moderate changes in dietary ration and temperature, and shows a significant negative relationship to condition factor.