Impact of in-season injury on quality of life and sleep duration in female youth volleyball athletes: a prospective study of 2073 players.

OBJECTIVES: The psychological impacts of injuries in youth athletes remain poorly defined. The purpose of this study was to evaluate the influence of injury on quality of life (QOL) and sleep in female high school volleyball athletes. METHODS: 2073 female high school volleyball players (15.6±1.1 years) completed the Pediatric Quality of Life survey (total QOL, physical, social, school, emotional and psychosocial function) and reported average sleep duration at the start and end of the season. Injury data were collected by school athletic trainers. Mixed effects linear regression models were used to compare changes in QOL and sleep duration during the season between (1) injured and uninjured athletes and (2) injured athletes who did or did not suffer a season-ending injury. RESULTS: Time-loss injuries were reported in 187 athletes with complete preseason and postseason data. During the season, injured athletes demonstrated a greater decrease in total QOL (ß=-1.3±0.5, p=0.012), as well as physical function (ß=-1.6±0.6, p=0.012), school function (ß=-2.0±0.76, p=0.01) and psychosocial function domains (ß=-1.2±0.6, p=0.039) compared with uninjured athletes. Athletes who sustained a season-ending injury had a significantly greater decrease in total QOL (ß=-6.8±2.0, p=0.006) and physical function (ß=-17±2.9, p<0.001) compared with injured athletes who were able to return to play during the season. CONCLUSION: In-season injuries are associated with significant decreases in total QOL as well as physical and psychosocial function. Healthcare providers should consider the impacts of injuries on QOL and sleep in youth athletes in order to optimise management and improve overall health.

Vitamin D deficiency and anatomical region alters porcine growth plate properties.

Ossification of growth plate cartilage mediates longitudinal extension of long bones. Biomechanical and biochemical disruptions of growth plate function may lead to abnormal bone growth. In humans and animals, severe dietary vitamin D deficiency can lead to rickets which features growth plate widening, resulting in abnormalities in growth. However, effects of marginal vitamin D deficiencies on growth plates are not well understood. The purpose of this study was to examine the effects of a vitamin D deficient diet in the 26-day nursery phase on mechanical properties (ultimate normal stress, ultimate shear stress, ultimate strain, and tangent modulus) of porcine growth plate. Standard uniaxial tensile tests were applied on bone-growth plate-bone sections and the total stress was decomposed into normal stress and shear stress. Ultimate shear stress and ultimate strain traits were lower in the vitamin D deficient group than in the control. Regional differences were observed in all four variables. Ultimate normal stress was higher in the anterior region, which was consistent with a previous study. Sex differences were detected in ultimate normal stress, which was higher in females than in males. Interestingly, the classical finding of growth plate widening seen in severe vitamin D deficiency was not observed in the pigs with marginal vitamin D deficiency utilized in this study.

Medial Patellofemoral Ligament Repair for Recurrent Patellar Instability: Successful Outcomes Among Patients With Low Coronal Malalignment and Normal Patellar Height.

Medial patellofemoral ligament (MPFL) repair is discouraged for the treatment of chronic, recurrent patellar instability (RPI) because of high reported failure rates. However, the senior author uses MPFL repair for chronic RPI in the setting of low tibial tubercle-trochlear groove (TT-TG) distance. In this retrospective case series, we report results and evaluate outcome predictors. We used billing records to identify all patients, 14 years or older, who underwent isolated repair for chronic RPI performed by a single surgeon between September 2010 and February 2019. The TT-TG distance, patellar height (Caton-Deschamps Index [CDI]), and trochlear depth were measured on preoperative magnetic resonance imaging; postoperative reports were reviewed; and post hoc Kuala scores were obtained to extend outcome length. Patellar dislocation or revision surgery was considered a failure. Nonfailures were categorized as excellent or fair, based on the most recent report. Univariable generalized estimating equation models were used to evaluate associations of predictors (radiographic parameters, age, ligamentous laxity, primary presenting complaint) with failure and/or success. A total of 93 isolated MPFL repairs were performed. After exclusions were made for workers' compensation insurance (n=4), substance abuse (n=3), major secondary trauma less than 3 months postoperatively (n=3), and follow-up of less than 12 months (n=42), 41 knees (38 patients) had median follow-up of 32 months (interquartile range, 19-48 months). All repairs were patellar sided. Outcomes for 4 knees were considered failures, 23 were excellent, and 14 were fair. Only increased CDI was associated with increased risk of failure (odds ratio, 1.70; 95% CI, 0.98-2.92; P=.06). Mean CDI was 1.23 mm (SD, 0.13 mm) for failures vs 1.08 mm (SD, 0.16 mm) for nonfailures. Failure rate was less than 10% following patellar-sided MPFL repair for treatment of chronic RPI among patients with low TT-TG distance. Increased patellar height was associated with higher risk of failure. [Orthopedics. 2022;45(1):e23-e29.].

The Relationships Between Sport Specialization, Sleep, and Quality of Life in Female Youth Volleyball Athletes.

BACKGROUND: Although sport specialization may be associated with stress and burnout among youth athletes, the relationship with quality of life (QOL) remains unknown. The purpose of this study was to evaluate the relationship between sport specialization, sleep, and QOL in female youth athletes. HYPOTHESIS: Higher levels of specialization are associated with increased daytime sleepiness and worse QOL. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 4. METHODS: Female high school volleyball players completed preseason surveys to determine sport specialization (low, moderate, high), injury history, QOL, sleep duration, and daytime sleepiness. QOL and sleep variables were compared across specialization groups. Multivariable linear regression models were developed to evaluate the associations between sleepiness, QOL, specialization, grade in school, and injury history. RESULTS: Of 1482 participants, 591 (40%), 436 (29%), and 455 (31%) were categorized as low, moderate, and high specialization, respectively. Highly specialized athletes demonstrated worse QOL (median 91.3 [interquartile range 86-96]) than low (92.4 [88-97], P = 0.05) and moderate (93.5 [88-99], P = 0.05) specialization groups and greater daytime sleepiness (11 [7-15]) than low (10 [6-14], P < 0.001) and moderate (10 [6-14], P < 0.001) specialization groups. In the multivariable model, QOL was negatively associated with prior injury occurrence (ß = -1.1 ± 0.5, P = 0.02), but not grade in school (ß = -0.08 ± 0.2, P = 0.71) or specialization (moderate: ß = 0.08 ± 0.5, P = 0.88; high: ß = -0.70 ± 0.5, P = 0.18). Daytime sleepiness increased with high specialization (ß = 1.12 ± 0.3, P < 0.001) and grade (ß = 0.76 ± 0.1, P < 0.001), but not prior injury (ß = 0.51 ±0.3, P = 0.10). CONCLUSION: Highly specialized female volleyball athletes demonstrate decreased QOL, perhaps because of higher rates of prior injury. Specialization is also associated with increased daytime sleepiness. CLINICAL RELEVANCE: Sport participation patterns and injury may have implications for QOL in youth athletes.

Keeping casts dry: A comparison of commercially available cast protectors using a mechanized short arm cast model.

BACKGROUND: Upper extremity fractures requiring cast immobilization are exceedingly common, especially in the pediatric population. Studies have shown improved outcomes when patients can participate in water-based activities while casted. However, waterproof cast material is not feasible in all clinical settings and wet cast complications remain a source of morbidity and expense. External cast protectors play an important role in preventing wet casts, but the efficacy of various commercially available brands during relevant water-based activity remains unknown. PURPOSES: To determine if there are differences in the rate and extent of moisture exposure for four commercially available cast protectors using a mechanized cast arm model and human volunteers. METHODS: A mechanized arm model was developed with four implanted humidity sensors. Cast protectors were applied over the arm, the model was submerged in water, and moved back and forth, simulating cast-wearers' motion. Data regarding humidity was recorded for successive 10-minute trials. Trials were analyzed using a mixed effects linear model to determine change in humidity over time. The top and bottom performing cast protectors were then applied to four adult volunteers prior to thirty minutes of swimming. Questionnaires regarding comfort and a qualitative assessment of cast wetness using a chemical color indicator were completed. RESULTS: 372 instances of sensor data from 96 10-minute trials was collected. The CVS, SealTight and Walgreens brands showed significant increases in humidity beginning at 10, 20 and 20 minutes, respectively. DryPro showed no significant increase in moisture level up to 50 minutes. In successive trials up to 120 minutes, DryPro showed only a 2% increase in moisture. In human subjects testing, 3/4 casts underneath CVS protectors had some degree of wetness-related color change that would require cast change as compared to 0/4 casts underneath DryPro protectors. CONCLUSIONS: Significant differences exist between commercially available cast protectors. Vacuum-sealed protectors performed best in both mechanical and human subject portions of this study and allowed minimal change in humidity for extended periods of sequential water immersion. Their cost is notably less than management of a wet cast. Lower-performing products may expose cast-wearers to an increased risk of wet cast complications.

Musculoskeletal Injuries and Their Association With Previous Concussion History: A Prospective Study of High School Volleyball and Soccer Players.

BACKGROUND: Sports-related concussions may have a neurobiological recovery period that exceeds the period of clinical recovery, and one consequence of an extended neurobiological recovery may be the risk of subsequent musculoskeletal injuries. Most literature citing an increased risk of musculoskeletal injury after a sports-related concussion has been reported in populations other than adolescent athletes. PURPOSE/HYPOTHESIS: The purpose was to prospectively determine if incidence rates of musculoskeletal injury differ between adolescent athletes with and without a previous sports-related concussion, while controlling for sex, sport, and age. A secondary aim was to determine if this relationship differs between male and female athletes of the same sport. Our hypotheses were that acute-noncontact injury rates would be higher in athletes with a previous sports-related concussion when compared with athletes without a previous sports-related concussion, and that this relationship would exist only in female athletes and not male athletes. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: High school soccer and volleyball players were recruited in 2 prospective cohort studies that observed 4837 athletes during their sporting season (females, 80%; soccer, 57%; mean [SD] age, 15.6 [1.1] years). At preseason, all participants self-reported demographics and previous sports-related concussion within the past 12 months. During the sport season, team athletic trainers electronically recorded athlete exposures and injury data, including injury characteristics. Injury rates per 1000 athlete exposures and injury rate ratios (IRRs) with 95% confidence intervals were calculated. All injury rates and IRRs were adjusted for sex, age, and sport. RESULTS: The rate of acute-noncontact lower extremity injury was 87% greater (IRR, 1.87; 95% CI, 1.29-2.74) in participants with a previous sports-related concussion versus those without one. The acute-noncontact lower extremity injury rates (IRRs) for females and males with a previous sports-related concussion were 1.76 (95% CI, 1.19-2.59) and 2.83 (95% CI, 0.85-9.50), respectively. No difference was detected in acute-contact (IRR, 0.98; 95% CI, 0.56-1.73) or overuse (IRR, 1.09; 95% CI, 0.51-2.37) lower extremity injury rates by previous sports-related concussion. CONCLUSION: Female adolescent athletes who reported a sports-related concussion within the past 12 months were more likely to sustain an acute-noncontact lower extremity injury during their high school sports season when compared with female athletes without a previous sport-related concussion.

Effects of tourniquet use in paediatric lower leg surgery.

BACKGROUND: The purpose of this study is to evaluate the use of the tourniquet and its effect on post-operative pain in the paediatric population following lower leg procedures. METHODS: A retrospective study of paediatric patients (under the age of 18) undergoing inpatient orthopaedic procedure below the knee performed at a single academic institution between 1st December 2013 and 31st January 2019 was conducted. Primary outcome measures of total opioid consumption during hospital stay and pre-operative nerve block utilization were retrieved from the electronic medical record (EMR). Secondary outcome measures of blood loss, tourniquet time, procedure time and length of hospital stay were also retrieved. Student's t-tests were used to assess statistical significance between two sample means. RESULTS: The final analysis included 204 paediatric procedures, 118 of which used a tourniquet and 86 of which did not. Paediatric patients with a tourniquet had significantly more opioid consumption post-operatively in the form of weight-based morphine equivalents/length of stay (p = 0.01) compared to those who had no tourniquet. This held true for males (p = 0.049) and females (p = 0.04) respectively. We did not see an increase in wound complications or return trips to the operating room in the tourniquet cohort. All procedures included an osseous component except one procedure in the non-tourniquet group. CONCLUSION: Minimizing opioid consumption may be achieved by avoiding tourniquet use in paediatric patients with lower leg procedures. In non-anaemic paediatric patients, it is reasonably risk-free to perform these surgeries without the use of tourniquet to decrease opioid dependence in the post-operative period. LEVEL OF EVIDENCE: III.

Is There a Connection Between Attention Deficit Hyperactivity Disorder and Osteochondritis Dissecans?

Background: To determine if children with Osteochondritis Dessicans (OCD) lesions of the distal femur are more likely to have a co-morbid diagnosis of Attention Deficit/ Hyperactivity Disorder (ADHD) than age matched controls and to assess the impact of ADHD on OCD outcomes. Methods: A retrospective chart review of patients treated at a single tertiary care hospital between 2000-2012 was performed. Charts were reviewed for a diagnosis of OCD of the distal femur in all skeletally immature patients (males < 16 years and females < 14 years). These were then screened for a comorbid diagnosis of ADHD. Age-matched controls with anterior knee pain without OCD were then reviewed to determine if ADHD was more common in the OCD population. Treatment and outcomes of the OCD lesions were then compared in children with and without ADHD. Results: The prevalence of ADHD was 23% in patients with OCD lesions and was significantly greater than the 11% found in the anterior knee pain age-matched controls (p<0.05). The average grade of lesions at presentation was similar in both groups (2.2 ADHD vs 2.1 no ADHD) however, at final follow-up, the average OCD grade was significantly worse for children with ADHD (1.4 vs 0.7, p<0.004). Conclusion: There is a significantly higher prevalence of ADHD in children with OCD lesions compared with age-matched controls. This study suggests children that with osteochondritis dessicans and ADHD may not have as favorable treatment course as children without the hyperactivity disorder.Level of Evidence: III.

Sport specialization and sport participation opportunities and their association with injury history in female high school volleyball athletes.

OBJECTIVE: Determine the association of sport specialization in female volleyball athletes with previous injury history and determine the association of sport specialization with volleyball participation opportunities. DESIGN: Cross-sectional. SETTING: Recruitment occurred from 83 Wisconsin high schools during the 2018 volleyball season. PARTICIPANTS: Female volleyball athletes (N = 1,588, grades 9-12, age = 15.6 ± 1.1 years). MAIN OUTCOMES: Participants completed a pre-season questionnaire soliciting information regarding 1) demographics, 2) sport specialization, 3) sport participation, and 4) sport-related injuries in the previous 12 months. Univariable logistic regression models were used to identify associations with previous injury. Chi-square analyses were used to investigate associations between sport specialization classification and other sport participation opportunities. RESULTS: Both moderately and highly specialized athletes were more likely to report a previous injury compared to low specialized athletes (moderate OR: 1.84 [1.29-2.62]; p < 0.001 and high OR: 2.30 [1.64-3.24]; p < 0.001). Highly specialized athletes were more likely to report participating in club volleyball, summer tournaments, and training camps in the past 12 months. Participants who reported participating in club volleyball, summer competitions, and training camps last year were more likely to report an injury. CONCLUSIONS: Specialization was associated with injury history and year-round volleyball opportunities among female adolescent volleyball athletes.

The outcome of in-situ fixation of unstable slipped capital femoral epiphysis.

There is limited information regarding the outcome of in-situ fixation of unstable slipped capital femoral epiphysis (U-SCFE). We aimed to report the outcome of a cohort of patients with U-SCFE that were treated with in-situ fixation, by comparing it to the outcome of patients with stable slipped capital femoral epiphysis (S-SCFE). After Institutional Review Board approval, a retrospective analysis of patients with SCFE that were treated with in-situ fixation at a single institution between 2005 and 2016 was performed. Preoperative and postoperative clinical and radiographic data was collected. The rate of complications, including avascular necrosis (AVN), and the presence of impingement were recorded. The outcome of U-SCFEs was compared to that of S-SCFEs. A total of 184 SCFEs in 154 patients (64% male; mean age 11.9 years) with a mean follow-up of 27 months were included. The SCFE was classified as stable in 90.2% of cases, and unstable in 9.8% of. The mean duration of symptoms prior to presentation was 3.2 months. The mean Southwick slip angle at the time of presentation was 33°. A single screw was used to fix all S-SCFEs, while U-SCFEs were treated with either one (66.7%) or two (33.3%) screws. For U-SCFEs, the joint was decompressed at the time of surgery by either needle aspiration or small capsular incision. The final range of motion of the affected hip was comparable in both groups. The overall rate of impingement was 29%. The rate of impingement in S-SCFE and U-SCFE was 27.6 and 44.4%, respectively (P = 0.1). Eight patients required a subsequent surgery (4.4%), all of whom originally have had a S-SCFE. Radiographic signs of AVN of the femoral head were seen in 2.2% of cases. The incidence of AVN of the femoral head in S-SCFEs and U-SCFEs was 1.2 and 11.1%, respectively (P = 0.04). The results of this study support previous findings that the risk of AVN is significantly higher in U-SCFE as compared to S-SCFEs.

Sport Participation and Specialization Characteristics Among Pediatric Soccer Athletes.

BACKGROUND: Soccer is an increasingly popular sport for children and adolescents in the United States. Little is known about participation patterns related to sport specialization. PURPOSE: To investigate soccer participation levels and sport specialization characteristics among youth soccer athletes. STUDY DESIGN: Cross-sectional study. METHODS: Adolescent athletes aged between 12 and 18 years completed an online survey addressing participant demographics, sports and soccer participation history, and level of specialization. Descriptive analyses characterized participation, while chi-square and Kruskal-Wallis tests assessed the influence of specialization, sex, and grade on survey variables. RESULTS: Overall, 83.7% of 746 respondents participated in an organized soccer league outside of school, and 37% played in multiple leagues concurrently. Nearly three-quarters of respondents trained in soccer more than 8 months of the year, with those who participated in club soccer being more likely to train more than 8 months of the year. More respondents were classified as high specialization (37.5%), followed by moderate (35.6%) and low (28.6%) specialization. No differences between sexes were noted for level of specialization or quitting other sports to specialize in soccer, but male athletes were more likely to train more than 8 months per year compared with female athletes. Respondents in older grades (9th-10th and 11th-12th grades) were more likely to be highly specialized and quit other sports to focus on soccer. No differences between grade levels were found among respondents training more than 8 months per year. CONCLUSION: The study findings suggest that many youth soccer athletes participated in multiple teams or leagues at the same time and trained more than 8 months of the year. Characteristics including participation on a club team, level of specialization, and male sex were associated with a greater likelihood of exceeding the 8-month training recommendation.

Prevention, treatment, and rehabilitation of anterior cruciate ligament injuries in children.

As more children and adolescents participate in competitive organized sports, there has been an increase in the reported incidence of anterior cruciate ligament (ACL) injuries in these age groups. ACL injuries in skeletally immature athletes present a challenge, as reconstruction must preserve the physis of the distal femur and of the proximal tibia to avoid growth disturbances. Historically, a skeletally immature athlete with an ACL injury was treated with a brace and activity modification until skeletal maturity, with ACL reconstruction being performed at that time in the "non-copers" who experienced instability. More recently, evidence has shown that delayed reconstruction may lead to increased damage to the meniscus and articular cartilage. As a result, early reconstruction is favored to protect the meniscus and allow continued physical activity. While adolescents at or those near skeletal maturity may be treated with standard reconstruction techniques, they may result in growth disturbances in younger athletes with significant growth remaining. In response to the growing need for ACL reconstruction techniques in skeletally immature individuals, physeal-sparing and physeal-respecting reconstruction techniques have been developed. In addition to the advancements in surgical technique, ACL injury prevention has also gained attention. This growing interest in ACL prevention is in part related to the high risk of ACL re-tear, either of the ACL graft or of the contralateral ACL, in children and adolescents. Recent reports indicate that well-designed neuromuscular training programs may reduce the risk of primary and subsequent ACL injuries.

Sanders II/III Calcaneus Fractures in Laborers: A Cost-Effectiveness Analysis and Call for Effectiveness Research.

OBJECTIVE: This study compares the cost and cost-effectiveness of treatments options for Sanders II/III displaced intra-articular calcaneus fractures (DIACFs) in laborers. METHODS: Literature on Sanders type II and III fractures was reviewed to determine complication rates and utility values for each treatment option. Costs were calculated using Medicare reimbursement and implant prices from our institution. Monte Carlo simulations were used to analyze a decision tree to determine the cost and cost-effectiveness of each treatment from a societal perspective. Sensitivity analysis was performed on all variables. RESULTS: Minimally invasive open reduction internal fixation (ORIF) (sinus tarsi approach with 4 screws alone) was least expensive ($23,329), followed by nonoperative care ($24,530) and traditional ORIF using extensile lateral approach ($27,963) (P < 0.001); this result was most sensitive to time out of work. Available cost-effectiveness data were limited, but our analysis suggests that minimally invasive ORIF is a dominant strategy, and traditional ORIF is superior to nonoperative care (incremental cost-effectiveness ratio $57,217/quality-adjusted life year). CONCLUSIONS: Our findings suggest that minimally invasive ORIF (sinus tarsi approach) is the least expensive option for managing Sanders II/III displaced intra-articular calcaneus fractures, followed by nonoperative care. Our cost-effectiveness results favor operative management but are highly sensitive to utility values and are weakened by scarce utility data. We therefore cannot currently recommend a treatment course based on value, and our primary conclusion must be that more extensive effectiveness research (ie, health-related quality of life data, not just functional outcomes) is desperately needed to elucidate the value of treatment options in this field. LEVEL OF EVIDENCE: Economic Level III. See Instructions for Authors for a complete description of levels of evidence.

NOD/LtSz-Rag1nullPfpnull mice: a new model system with increased levels of human peripheral leukocyte and hematopoietic stem-cell engraftment.

BACKGROUND: A critical need exists for effective small-animal models that accept engraftment of human hematopoietic progenitor cells and mature lymphocytes. The purpose of this study was to determine the phenotypic effects of perforin (Pfp) deficiency on nonobese diabetic (NOD)-Rag1null mice and to evaluate the ability of NOD/LtSz-Rag1nullPfpnull recipients to support engraftment with human hematolymphoid cells. METHODS: A new genetic stock of NOD mice doubly homozygous for targeted mutations at the recombination activating gene (Rag)-1 and Pfp genes was developed. NOD/LtSz-Rag1nullPfpnull mice were studied for immunopathologic and hematologic abnormalities. The ability of these mice to support engraftment with human peripheral blood mononuclear cells (PBMC) and umbilical-cord blood hematopoietic progenitor cells was assessed. RESULTS: NOD/LtSz-Rag1nullPfpnull mice lacked mature B cells, T cells, natural killer (NK) cell cytotoxic activity and were devoid of serum immunoglobulin (Ig) throughout a 37-week lifespan. These mice supported heightened engraftment with human PBMC as compared with NOD/LtSz-Rag1null controls as evidenced by a 4- to 5-fold increase in percentages of human lymphocytes and a 7- to 13-fold increase in percentages of CD4+ T cells in the peripheral blood and spleen. Total numbers of human CD4+ T cells were increased approximately 20-fold in the spleens of NOD/LtSz-Rag1nullPfpnull mice. These mice also showed approximately 12-fold higher levels of engraftment with human umbilical-cord blood cells compared with NOD/LtSz-Rag1null mice. CONCLUSIONS: NOD/LtSz-Rag1nullPfpnull mice are devoid of mature B cell, T cell, and NK cell cytotoxic activity, engraft at high levels with human PBMC, and hematopoietic progenitor cells and provide a new NK cell-deficient model for human hematolymphoid cell engraftment.

Health research networks on the web: an analysis of the Brazilian presence.

In order to map Brazilian institutions' web presence in an international network of health research institutions, a study was conducted in 2009, including 190 institutions from 42 countries. The sample was based on WHO (World Health Organization) collaborating centers, and the methodology used webometric analyses and techniques, especially interlinks, and social network analysis. The results showed the presence of five Brazilian institutions, featuring the Oswaldo Cruz Foundation (Fiocruz), showing links to 20 countries and 42 institutions. Through the interface between the health field and the web, the study aims to contribute to future analyses and a plan for strategic repositioning of these institutions in the virtual world, as well as to the elaboration of public policies and recognition of webometrics as an area to be explored and applied to various other fields of knowledge.

Cooperation in health: mapping collaborative networks on the web.

OBJECTIVE: To map and investigate the relationships established on the web between leading health-research institutions around the world. METHODS: Sample selection was based on the World Health Organization (WHO) Collaborating Centres (CCs). Data on the 768 active CCs in 89 countries were retrieved from the WHO's database. The final sample consisted of 190 institutions devoted to health sciences in 42 countries. Data on each institution's website were retrieved using webometric techniques (interlinking), and an asymmetric matrix was generated for social network analysis. FINDINGS: The results showed that American and European institutions, such as the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH) and the National Institute of Health and Medical Research (INSERM), are the most highly connected on the web and have a higher capacity to attract hyperlinks. The Karolinska Institute (KI-SE) in Sweden is well placed as an articulation point between several integrants of the network and the component's core but lacks general recognition on the web by hyperlinks. Regarding the north-south divide, Mexico and Brazil appear to be key southern players on the web. The results showed that the hyperlinks exchanged between northern and southern countries present an abysmal gap: 99.49% of the hyperlinks provided by the North are directed toward the North itself, in contrast to 0.51% that are directed toward the South. Regarding the South, its institutions are more connected to its northern partners, with 98.46% of its hyperlinks directed toward the North, and mainly toward the United States, compared with 1.54% toward southern neighbors. CONCLUSION: It is advisable to strengthen integration policies on the web and to increase web networking through hyperlink exchange. In this way, the web could actually reflect international cooperation in health and help to legitimize and enhance the visibility of the many existing south-south collaboration networks.

Health research networks on the web: an analysis of the Brazilian presence / Redes de pesquisa em saúde na web: uma análise da presença brasileira / Redes de investigación en salud en la web: un análisis de la presencia brasileña

In order to map Brazilian institutions’ web presence in an international network of health research institutions, a study was conducted in 2009, including 190 institutions from 42 countries. The sample was based on WHO (World Health Organization) collaborating centers, and the methodology used webometric analyses and techniques, especially interlinks, and social network analysis. The results showed the presence of five Brazilian institutions, featuring the Oswaldo Cruz Foundation (Fiocruz), showing links to 20 countries and 42 institutions. Through the interface between the health field and the web, the study aims to contribute to future analyses and a plan for strategic repositioning of these institutions in the virtual world, as well as to the elaboration of public policies and recognition of webometrics as an area to be explored and applied to various other fields of knowledge.

Com a finalidade de mapear na web a presença de instituições brasileiras em uma rede internacional de instituições de pesquisa no campo da saúde, foi realizado, em 2009, um estudo com 190 instituições, representando 42 países. A amostra foi selecionada com base nos centros colaboradores da Organização Mundial da Saúde (OMS) e a metodologia empregada se baseou em análises e técnicas webmétricas, especialmente por meio de interlinks, e de redes sociais. Os resultados mostram a presença de cinco instituições brasileiras, com destaque para a Fundação Oswaldo Cruz (Fiocruz), que apresenta conexões com 20 países e 42 instituições. Pela interface entre o campo da saúde e a web, este trabalho pretende contribuir não apenas para análises futuras e um plano de reposicionamento estratégico dessas instituições no mundo virtual, mas também para a elaboração de políticas públicas e o reconhecimento da webmetria como uma área a ser explorada e aplicada a diversos outros campos do conhecimento.

Con el propósito de mapear la presencia en la web de las instituciones brasileñas, en una red internacional de instituciones de investigación en el campo de la salud, se realizó en 2009 un estudio de 190 instituciones, que representan a 42 países. La muestra fue seleccionada en base a los centros colaboradores de la Organización Mundial de la Salud (OMS) y la metodología se basó en análisis y técnicas webmétricas, especialmente de interlinks y redes sociales. Los resultados muestran la presencia de cinco instituciones brasileñas, en especial de la Fundación Oswaldo Cruz (Fiocruz), que cuenta con conexiones a 20 países y 42 instituciones. A través de la interfaz entre el campo de la salud y de la web, este trabajo pretende contribuir no sólo a un análisis más detallado y un plan de reposicionamiento estratégico de estas instituciones en el mundo virtual, sino también al desarrollo de políticas públicas y el reconocimiento de la webmetría como un área que debe ser investigada y aplicada a otros campos del conocimiento.

Absence of CD5 dramatically reduces progression of pulmonary inflammatory lesions in SHP-1 protein-tyrosine phosphatase-deficient 'viable motheaten' mice.

Mice homozygous for the viable motheaten (Hcph(me-v)) mutation are deficient in SHP-1 protein-tyrosine phosphatase, resulting in severe systemic autoimmunity and immune dysfunction. A high percentage of B-cells in viable motheaten mice express the cell surface glycoprotein CD5, in contrast to wild type mice that express CD5 on only a small percentage of B-cells. CD5(+) B-cells have been associated with autoantibody production. To determine the role of CD5 in the development of the inflammatory disease in me(v)/ me(v) mice, we created a stock of CD5(null)me(v)/ me(v) mice. The longevity of CD5(null)me(v)/ me(v) mice was increased 69% in comparison to me(v)/ me(v) mice on a similar (B6;129) background. The increased lifespan was associated with a marked reduction in pulmonary inflammation. Flow cytometry analysis of spleen cells from CD5(null)me(v)/ me(v) mice at 9-12 weeks of age revealed significant decreases in percentages of IgM/B220 double positive B-cells, Mac-1/Gr-1 double positive cells and CD4(+) T-cells compared with me(v)/ me(v) mice. CD5(null)me(v)/ me(v) mice also had significantly lower serum IgM levels in comparison to me(v)/ me(v) mice. Study of CD5(null)me(v)/ me(v) mice may provide further insight into the role of CD5 in cell signaling and may help explain the observed association of CD5(+) B-cells with autoimmune disease.