Return to Play in Youth Athletes: Role of the Radiologist with Focus on the Upper Extremity.

Increase in youth sports participation, longer duration of play, and earlier starting points have increased the prevalence of acute and repetitive overuse musculoskeletal injuries. This rise in injury rates has led to increased efforts to better understand the susceptible sites of injury that are unique to the growing immature skeleton. Upper extremity injuries are currently the best studied, particularly those that occur among pediatric baseball players and gymnasts. The weak link in skeletally immature athletes is the growth plate complex that includes those injuries located at the epiphyseal and apophyseal primary physes and the peripherally located secondary physes. This article reviews the anatomy and function of these growth plate complexes, followed by a discussion of the pathophysiologic mechanisms, spectrum of imaging findings, and existing evidence-based guidelines for injury prevention and return to play.

Maturation-dependent patterns of knee injuries among symptomatic pediatric soccer players on MRI.

OBJECTIVE: To systematically investigate the prevalence of knee MRI findings among symptomatic pediatric soccer players with respect to skeletal maturity and to identify predictors of surgery. METHODS: This IRB-approved, HIPAA-compliant retrospective study included soccer players (< 18 years of age) who underwent MRI examinations in the past 5 years (2018-2023). Two radiologists retrospectively and independently reviewed all examinations to categorize skeletal maturity and to identify osseous and soft tissue findings. Findings were compared between maturation groups, and logistic regression models were used to identify predictors of surgery. RESULTS: Ninety-seven players (45 boys, 52 girls) included 39 skeletally immature, 21 maturing, and 37 mature knees. Kappa coefficient for interobserver reliability ranged between 0.65 and 1.00. Osgood-Schlatter disease (OSD) was more common among immature than maturing and mature knees (25% vs 14% and 5%, p = 0.04); anterior cruciate ligament (ACL) injury was more common among maturing and mature than immature knees (59% and 48%, vs 15%, p < 0.01); and meniscal tears were more common among mature than immature and maturing knees (medial, 41% vs 18% and 14%, p = 0.03; lateral, 43% vs 21% and 19%, p = 0.04). Players in the mature group were more likely to undergo surgery (p = 0.01). The presence of an effusion (OR = 19.5, 95% CI 2.8-240.9, p = 0.01), ACL injury (OR = 170.0, 95% CI 1.3-6996.9, p < 0.01), and lateral meniscal tears (OR = 10.8, 95% CI 1.8-106.1, p = 0.02) were independent predictors of surgery. CONCLUSION: Differential patterns of injury were found among symptomatic pediatric soccer players; the presence of an effusion, ACL injury, and lateral meniscal tears were independent predictors of surgery, likely contributing to the higher rates of surgery among skeletally mature players.

Tarsal Navicular Bone Stress Injuries: A Multicenter Case Series Investigating Clinical Presentation, Diagnostic Approach, Treatment, and Return to Sport in Adolescent Athletes.

BACKGROUND: Tarsal navicular bone stress injuries (BSIs) are considered "high risk" because of prolonged healing times and higher rates of nonunion in adult populations but, to our knowledge, have not been comprehensively examined in adolescent athletes. PURPOSE: To describe the characteristics of tarsal navicular BSIs in adolescents. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A retrospective analysis of patients aged 10 to 19 years with a radiographically diagnosed tarsal navicular BSI was performed at 8 academic centers over a 9-year study period. Age, sex, body mass index (BMI), primary sport, physical examination findings, imaging, treatment, surgical technique, return-to-sport time, and complications were analyzed. RESULTS: Among 110 patients (mean age, 14.7 ± 2.7 years; 65% female), common primary sports were cross-country/track and field (29/92 [32%]) and gymnastics/dance (25/92 [27%]). Grade 4 BSIs were identified in 44% (48/110) of patients, with fracture lines present on radiography or magnetic resonance imaging. Nonoperative treatment (mean age, 14.4 ± 2.6 years), consisting of protected weightbearing and either a protective boot (69/88 [78%]) or a cast (19/88 [22%]), was trialed in all patients and was successful in 94 patients (85%). Operative treatment (mean age, 17.1 ± 1.4 years) was ultimately pursued for 16 patients (15%). Patients who required surgery had a higher BMI and a higher percentage of fracture lines present on imaging (nonoperative: 36/94 [38%]; operative: 14/16 [88%]). The median time to return to weightbearing, running, and full sport was significantly longer in duration for the operative group than the nonoperative group (P <.05). Complications associated with surgery included 1 case each of delayed union, nonunion, and painful implants, the latter of which required secondary surgery. CONCLUSION: Adolescent tarsal navicular BSIs were identified most commonly in female patients in leanness sports. Adolescents who required surgery were more likely to be older, have higher BMIs, and have grade 4 BSIs, and they returned to sport within a median of 5 months after single- or double-screw fixation with a low risk of postoperative complications. A better understanding of the presenting signs and symptoms and appropriate diagnostic imaging of navicular BSIs may lead to an earlier diagnosis and improved outcomes.

Team approach to polypharmacy evaluation and reduction: feasibility randomized trial of a structured clinical pathway to reduce polypharmacy.

BACKGROUND: Polypharmacy is associated with poorer health outcomes in older adults. Other than the associated multimorbidity, factors contributing to this association could include medication adverse effects and interactions, difficulties in managing complicated medication regimes, and reduced medication adherence. It is unknown how reversible these negative associations may be if polypharmacy is reduced. The purpose of this study was to determine the feasibility of implementing an operationalized clinical pathway aimed to reduce polypharmacy in primary care and to pilot measurement tools suitable for assessing change in health outcomes in a larger randomized controlled trial (RCT). METHODS: We randomized consenting patients ≥ 70 years old on ≥ 5 long-term medications into intervention or control groups. We collected baseline demographic information and research outcome measures at baseline and 6 months. We assessed four categories of feasibility outcomes: process, resource, management, and scientific. The intervention group received TAPER (team approach to polypharmacy evaluation and reduction), a clinical pathway for reducing polypharmacy using "pause and monitor" drug holiday approach. TAPER integrates patients' goals, priorities, and preferences with an evidence-based "machine screen" to identify potentially problematic medications and support a tapering and monitoring process, all supported by a web-based system, TaperMD. Patients met with a clinical pharmacist and then with their family physician to finalize a plan for optimization of medications using TaperMD. The control group received usual care and were offered TAPER after follow-up at 6 months. RESULTS: All 9 criteria for feasibility were met across the 4 feasibility outcome domains. Of 85 patients screened for eligibility, 39 eligible patients were recruited and randomized; two were excluded post hoc for not meeting the age requirement. Withdrawals (2) and losses to follow-up (3) were small and evenly distributed between arms. Areas for intervention and research process improvement were identified. In general, outcome measures performed well and appeared suitable for assessing change in a larger RCT. CONCLUSIONS: Results from this feasibility study indicate that TAPER as a clinical pathway is feasible to implement in a primary care team setting and in an RCT research framework. Outcome trends suggest effectiveness. A large-scale RCT will be conducted to investigate the effectiveness of TAPER on reducing polypharmacy and improving health outcomes. TRIAL REGISTRATION: clinicaltrials.gov NCT02562352 , Registered September 29, 2015.

Linking Patients' Goals and Priorities to Recommendations for Medication Changes in a Polypharmacy-Focused Structured Clinical Pathway.

Polypharmacy is associated with poorer health outcomes in older adults. It is challenging to minimize the harmful effects of medications while maximizing benefits of single-disease-focused recommendations. Integrating patient input can balance these factors. The objectives are to describe the goals, priorities, and preferences of participants asked about these in a structured process to polypharmacy, and to describe the extent that decision-making within the process mapped onto these, signaling a patient-centered approach. This is a single-group quasi-experimental study, nested within a feasibility randomized controlled trial. Patient goals and priorities were mapped to medication recommendations made during the intervention. Overall, there were 33 participants who reported 55 functional goals and 66 symptom priorities, and 16 participants reported unwanted medications. Overall, 154 recommendations for medication alterations occurred. Of those, 68 (44%) recommendations mapped to the individual's goals and priorities, whereas the rest were based on clinical judgment where no priorities were expressed. Our results signal this process supports a patient-centered approach: allowing conversations around goals and priorities in a structured process to polypharmacy should be integrated into subsequent medication decisions.

Stress Injuries of the Knee.

Stress injuries to the bone and physis of the knee are common in the active adolescent patient and can be broken down into bone stress injuries (BSIs) and chronic physeal stress injuries. BSIs result from prolonged, repetitive bone loading, whereas chronic physeal stress injuries develop from repetitive loading to the apophysis or epiphysis. Most stress injuries of the knee resolve with relative rest but will occasionally need surgical intervention in more severe cases. Early and accurate identification is paramount for optimal management and to avoid long-term consequences.

A Mixed Method Study of Teachers' Appraisals of Student Wellness Services and Supports During COVID-19.

BACKGROUND: Understanding teachers' appraisals of student wellness services and supports during COVID-19 is essential to strengthening services and improving student health outcomes. This mixed-method study aimed to examine US PK-12 teachers' appraisals of student wellness services and supports during COVID-19. METHODS: This study focuses on qualitative data from 291 teachers' open-ended responses to the question: "What do you wish your school leaders knew about this (wellness support) aspect of your work?" and whose responses described wellness services and supports. A qualitative content analysis was conducted by an interdisciplinary research team using open- and axial coding. RESULTS: Three main themes emerged. (1) insufficient access to mental health professionals and programming at schools, (2) concern about the quality of available services, and (3) a need for teacher professional development and support on student wellness. Statistically significant differences in teacher appraisals of insufficient access to mental health professionals and programming were found based on grade level taught and percentage of immigrant students in the school. CONCLUSION: With amplified student wellness needs, school personnel, including school leaders, must consider ways to allocate additional resources/staffing, assess the quality of services and supports, and design professional development opportunities to support teachers' involvement in supporting student wellness needs.

Early targeted heart rate aerobic exercise versus placebo stretching for sport-related concussion in adolescents: a randomised controlled trial.

BACKGROUND: Sport-related concussion is a public health problem, particularly in adolescents. Quality of life is reduced in adolescents with persistent post-concussive symptoms (symptoms >28 days). We replicated a previous randomised controlled trial to validate the safety, efficacy, and generalisability of, and objective adherence to, prescribed early targeted heart rate subsymptom threshold aerobic exercise compared with placebo-like stretching exercise for adolescent recovery from sport-related concussion and for reducing the risk of persistent post-concussive symptoms. METHODS: This randomised controlled trial was done at three community and hospital-affiliated sports medicine concussion centres in the USA. Male and female adolescent athletes (aged 13-18 years) presenting within 10 days of sport-related concussion were randomly assigned to individualised subsymptom threshold aerobic or stretching exercise at least 20 min daily, for up to 4 weeks after injury. Exercise adherence and intensity were measured by heart rate monitors. The primary outcome was clinical recovery (ie, return to baseline symptoms, normal exercise tolerance, and a normal physical examination) within the 4-week intervention period, and development of persistent post-concussive symptoms beyond 28 days after injury. This study is registered with ClinicalTrials.gov, NCT02959216. FINDINGS: Between Aug 1, 2018, and March 31, 2020, 118 adolescents were recruited (61 were randomly assigned to the aerobic exercise group and 57 to the stretching exercise group) and included in the intention-to-treat analysis. On survival analysis, controlling for sex, site, and mean daily exercise time, patients assigned to aerobic exercise were more likely to recover within 4 weeks after injury compared with those assigned to stretching exercise, with a 48% reduced risk of persistent post-concussive symptoms (hazard ratio for stretching vs aerobic exercise of 0·52 [95% CI 0·28-0·97], p=0·039). No adverse events were reported. INTERPRETATION: This multicentre study found that early treatment with subsymptom threshold aerobic exercise safely speeds recovery from sport-related concussion and reduces the risk for persistent post-concussive symptoms, an important result given the impact of delayed recovery on adolescent quality of life. Adherence was good and there were no adverse events from this non-pharmacological treatment. These results suggest that physicians should not only permit, but consider prescribing, early subsymptom threshold physical activity to adolescents as treatment for sport-related concussion and to reduce the risk of persistent post-concussive symptoms. FUNDING: American Medical Society for Sports Medicine.

Team approach to polypharmacy evaluation and reduction: study protocol for a randomized controlled trial.

BACKGROUND: Polypharmacy in older adults can be associated with negative outcomes including falls, impaired cognition, reduced quality of life, and general and functional decline. It is not clear to what extent these are reversible if the number of medications is reduced. Primary care does not have a systematic approach for reducing inappropriate polypharmacy, and there are few, if any, approaches that account for the patient's priorities and preferences. The primary objective of this study is to test the effect of TAPER (Team Approach to Polypharmacy Evaluation and Reduction), a structured operationalized clinical pathway focused on reducing inappropriate polypharmacy. TAPER integrates evidence tools for identifying potentially inappropriate medications, tapering, and monitoring guidance and explicit elicitation of patient priorities and preferences. We aim to determine the effect of TAPER on the number of medications (primary outcome) and health-related outcomes associated with polypharmacy in older adults. METHODS: We designed a multi-center randomized controlled trial, with the lead implementation site in Hamilton, Ontario. Older adults aged 70 years or older who are on five or more medications will be eligible to participate. A total of 360 participants will be recruited. Participants will be assigned to either the control or intervention arm. The intervention involves a comprehensive multidisciplinary medication review by pharmacists and physicians in partnership with patients. This review will be focused on reducing medication burden, with the assumption that this will reduce the risks and harms of polypharmacy. The control group is a wait list, and control patients will be given appointments for the TAPER intervention at a date after the final outcome assessment. All patients will be followed up and outcomes measured in both groups at baseline and 6 months. DISCUSSION: Our trial is unique in its design in that it aims to introduce an operationalized structured clinical pathway aimed to reduce polypharmacy in a primary care setting while at the same time recording patient's goals and priorities for treatment. TRIAL REGISTRATION: Clinical Trials.gov NCT02942927. First registered on October 24, 2016.

Essential Elements That Contribute to the Recovery of Persons With Severe Mental Illness: A Systematic Scoping Study.

Introduction: There is an increasing emphasis on recovery-oriented care in the design and delivery of mental health services. Research has demonstrated that recovery-oriented services are understood differently depending on the stakeholders involved. Variations in interpretations of recovery lead to challenges in creating systematically organized environments that deliver a consistent recovery-oriented approach to care. The existing evidence on recovery-oriented practice is scattered and difficult to apply. Through this systematic scoping study, we aim to identify and map the essential elements that contribute to recovery outcomes for persons living with severe mental illness. Methods: We used the Arksey & O'Malley framework as our guiding approach. Seven key databases (MEDLINE, PubMed, CINAHL/EBSCO, EMBASE, ProQuest, PsycINFO, and Google Scholar) were searched using index terms and keywords relating to recovery and severe mental illness. To be included, studies had to be peer-reviewed, published after 1988, had persons with severe mental illness as the focal population, and have used recovery in the context of mental health. The search was conducted in August 2018 and last updated in February 2020. Results: Out of 4,496 sources identified, sixty (n = 60) sources were included that met all of the selection criteria. Three major elements of recovery that emerged from the synthesis (n = 60) include relationships, sense of meaning, and participation. Some sources (n = 20) highlighted specific elements such as hope, resilience, self-efficacy, spirituality, social support, empowerment, race/ethnicity etc. and their association with the processes underpinning recovery. Discussion: The findings of this study enable mental health professionals to incorporate the identified key elements into strategic interventions to facilitate recovery for clients with severe mental illness, and thereby facilitate recovery-oriented practice. The review also documents important gaps in knowledge related to the elements of recovery and identifies a critical need for future studies to address this issue.

Effect of cognitive activity level on duration of post-concussion symptoms.

OBJECTIVE: To determine the effect of cognitive activity level on duration of post-concussion symptoms. METHODS: We conducted a prospective cohort study of patients who presented to a Sports Concussion Clinic within 3 weeks of injury between October 2009 and July 2011. At each visit, patients completed a scale that recorded their average level of cognitive activity since the previous visit. The product of cognitive activity level and days between visits (cognitive activity-days) was calculated and divided into quartiles. Kaplan-Meier Product Limit method was used to generate curves of symptom duration based on cognitive activity level. To adjust for other possible predictors of concussion recovery, we constructed a Cox proportional hazard model with cognitive activity-days as the main predictor. RESULTS: Of the 335 patients included in the study, 62% were male, 19% reported a loss of consciousness, and 37% reported experiencing amnesia at the time of injury. The mean age of participants was 15 years (range, 8-23) and the mean number of previous concussions was 0.76; 39% of athletes had sustained a previous concussion. The mean Post-Concussion Symptom Scale score at the initial visit was 30 (SD, 26). The overall mean duration of symptoms was 43 days (SD, 53). Of all variables assessed, only total symptom burden at initial visit and cognitive activity level were independently associated with duration of symptoms. CONCLUSIONS: Increased cognitive activity is associated with longer recovery from concussion. This study supports the use of cognitive rest and adds to the current consensus opinion.

Emergency ultrasound-assisted examination of skin and soft tissue infections in the pediatric emergency department.

OBJECTIVES: The objective was to evaluate the test characteristics of clinical examination (CE) with the addition of bedside emergency ultrasound (CE+EUS) compared to CE alone in determining skin and soft tissue infections (SSTIs) that require drainage in pediatric patients. METHODS: This was a prospective study of CE+EUS as a diagnostic test for the evaluation of patients 2 months to 19 years of age evaluated for SSTIs in a pediatric emergency department (ED). Two physicians clinically and independently evaluated each lesion, and the reliability of the CE for diagnosing lesions requiring drainage was calculated. Trained pediatric emergency physicians performed US following their CEs. The authors determined and compared the test characteristics for evaluating a SSTI requiring drainage for CE alone and for CE+EUS for those lesions in which the two physicians agreed and were certain regarding their CE diagnosis (clinically evident). The performance of CE+EUS was evaluated in those lesions in which the two physicians either disagreed or were uncertain of their diagnosis (not clinically evident). The reference standard for determining if a lesion required drainage was defined as pus expressed at the time of the ED visit or within 2 days by follow-up assessment. RESULTS: A total of 387 lesions underwent CE+EUS and were analyzed. CE agreement between physicians was fair (κ = 0.38). For the 228 lesions for which physicians agreed and were certain of their diagnoses, sensitivity was 94.7% for CE and 93.1% for CE+EUS (difference = -1.7%; 95% confidence interval [CI] = -3.4% to 0%). The specificity of CE was 84.2% compared to 81.4% for CE+EUS (difference = -2.8%; 95% CI = -9.7% to 4.1%). For lesions not clinically evident based on CE, the sensitivity of CE was 43.7%, compared with 77.6% for CE+EUS (difference = 33.9%; 95% CI = 1.2% to 66.6%). The specificity of CE for this group was 42.0%, compared with 61.3% for CE+EUS (difference = 19.3%; 95% CI = -13.8% to 52.4%). CONCLUSIONS: For clinically evident lesions, the addition of ultrasound (US) did not significantly improve the already highly accurate CE for diagnosing lesions requiring drainage in this study population. However, there were many lesions that were not clinically evident, and in these cases, US may improve the accuracy of the CE.

Regulation of IL-17A production is distinct from IL-17F in a primary human cell co-culture model of T cell-mediated B cell activation.

Improper regulation of B cell responses leads to excessive production of antibodies and contributes to the development of autoimmune disease. T helper 17 (Th17) cells also drive the development of autoimmune disease, but the role of B cells in shaping Th17 cell-mediated immune responses, as well as the reciprocal regulation of B cell responses by IL-17 family cytokines, remains unclear. The aim of this study was to characterize the regulation of IL-17A and IL-17F in a model of T cell-dependent B cell activation. Stimulation of primary human B cell and peripheral blood mononuclear cell (BT) co-cultures with α-IgM and a non-mitogenic concentration of superantigens for three days promoted a Th17 cell response as evidenced by increased expression of Th17-related gene transcripts, including Il17f, Il21, Il22, and Il23r, in CD4 T cells, as well as the secretion of IL-17A and IL-17F protein. We tested the ability of 144 pharmacologic modulators representing 91 different targets or pathways to regulate IL-17A and IL-17F production in these stimulated BT co-cultures. IL-17A production was found to be preferentially sensitive to inhibition of the PI3K/mTOR pathway, while prostaglandin EP receptor agonists, including PGE2, increased IL-17A concentrations. In contrast, the production of IL-17F was inhibited by PGE2, but selectively increased by TLR2 and TLR5 agonists. These results indicate that IL-17A regulation is distinct from IL-17F in stimulated BT co-cultures and that this co-culture approach can be used to identify pathway mechanisms and novel agents that selectively inhibit production of IL-17A or IL-17F.

Multiple Arabidopsis genes primed for recruitment into C4 photosynthesis.

C(4) photosynthesis occurs in the most productive crops and vegetation on the planet, and has become widespread because it allows increased rates of photosynthesis compared with the ancestral C(3) pathway. Leaves of C(4) plants typically possess complicated alterations to photosynthesis, such that its reactions are compartmented between mesophyll and bundle sheath cells. Despite its complexity, the C(4) pathway has arisen independently in 62 separate lineages of land plants, and so represents one of the most striking examples of convergent evolution known. We demonstrate that elements in untranslated regions (UTRs) of multiple genes important for C(4) photosynthesis contribute to the metabolic compartmentalization characteristic of a C(4) leaf. Either the 5' or the 3' UTR is sufficient for cell specificity, indicating that functional redundancy underlies this key aspect of C(4) gene expression. Furthermore, we show that orthologous PPDK and CA genes from the C(3) plant Arabidopsis thaliana are primed for recruitment into the C(4) pathway. Elements sufficient for M-cell specificity in C(4) leaves are also present in both the 5' and 3' UTRs of these C(3) A. thaliana genes. These data indicate functional latency within the UTRs of genes from C(3) species that have been recruited into the C(4) pathway. The repeated recruitment of pre-existing cis-elements in C(3) genes may have facilitated the evolution of C(4) photosynthesis. These data also highlight the importance of alterations in trans in producing a functional C(4) leaf, and so provide insight into both the evolution and molecular basis of this important type of photosynthesis.

Topical anesthetic cream is associated with spontaneous cutaneous abscess drainage in children.

OBJECTIVE: The objective of the study was to determine whether use of topical anesthetic cream increases spontaneous drainage of skin abscesses and reduces the need for procedural sedation. METHODS: A retrospective multicenter cohort study from 3 academic pediatric emergency departments was conducted for randomly selected children with a cutaneous abscess in 2007. Children up to 18 years of age were eligible if they had a skin abscess at presentation. Demographics, abscess characteristics, and use of a topical analgesic were obtained from medical records. RESULTS: Of 300 subjects, 58% were female and the median age was 7.8 years (interquartile range, 2-15 years). Mean abscess size was 3.5 ± 2.4 cm, most commonly located on the lower extremity (30%), buttocks (24%), and face (12%). A drainage procedure was required in 178 children, of whom 9 underwent drainage in the operating room. Of the remaining 169 children who underwent emergency department-based drainage, 110 (65%) had a topical anesthetic agent with an occlusive dressing placed on their abscess before drainage. Use of a topical anesthetic resulted in spontaneous abscess drainage in 26 patients, of whom 3 no longer required any further intervention. In the 166 patients who underwent additional manipulation, procedural sedation was required in 26 (24%) of those who had application of a topical anesthetic and in 24 (41%) of those who had no topical anesthetic (odds ratio, 0.45; 95% confidence interval, 0.23-0.89). CONCLUSIONS: Topical anesthetic cream application before drainage procedures promotes spontaneous drainage and decreases the need for procedural sedation for pediatric cutaneous abscess patients.

The concerns of school staff in caring for children with diabetes in primary school.

OBJECTIVES: Primary school children spend 25% of their waking hours in school. Education authorities have a duty of care to support children with chronic illnesses within schools, but this is very variable. This study has examined the concerns of primary school staff working with children with Type 1 diabetes and their parents, and related these concerns to the views of health-care professionals (HCP) working with school personnel. METHODS: We undertook in-depth, semi-structured face-to-face interviews with 22 primary school staff and 5 multidisciplinary HCP from the local healthcare team. Interview transcripts were analysed using a structured, iterative approach grouping together key themes and issues to create a coding scheme. RESULTS: Primary school staff expressed a range of concerns about injecting and blood glucose testing, the ability of children to mishandle their condition, and corresponding reactions of parents to school decisions on health-based matters. These fears had some convergence with the perspectives of HCP who also highlighted the institutional nature of primary schools and dynamics of home/family life as factors impacting upon care of children with diabetes at school. CONCLUSIONS: Increased training for teachers having direct and current responsibility for children with diabetes was thought to lessen anxiety. Greater and more accessible knowledge about diabetes for all staff was requested. A range of practical management strategies were highlighted, including fostering good communication and teamwork between child, parent, school, and HCP. Professionals felt that support services would improve by using community-based dieticians and including psychological input into the diabetes team.

Management of pediatric skin abscesses in pediatric, general academic and community emergency departments.

OBJECTIVES: To compare the evaluation and management of pediatric cutaneous abscess patients at three different emergency department (ED) settings. METHOD: We conducted a retrospective cohort study at two academic pediatric hospital EDs, a general academic ED and a community ED in 2007, with random sampling of 100 patients at the three academic EDs and inclusion of 92 patients from the community ED. Eligible patients were ≤18 years who had a cutaneous abscess. We recorded demographics, predisposing conditions, physical exam findings, incision and drainage procedures, therapeutics and final disposition. Laboratory data were reviewed for culture results and antimicrobial sensitivities. For subjects managed as outpatients from the ED, we determined where patients were instructed to follow up and, using electronic medical records, ascertained the proportion of patients who returned to the ED for further management. RESULT: Of 392 subjects, 59% were female and the median age was 7.7 years. Children at academic sites had larger abscesses compared to community patients, (3.5 versus 2.5 cm, p=0.02). Abscess incision and drainage occurred in 225 (57%) children, with the lowest rate at the academic pediatric hospital EDs (51%) despite the relatively larger abscess size. Procedural sedation and the collection of wound cultures were more frequent at the academic pediatric hospital and the general academic EDs. Methicillin-resistant Staphylococcus aureus (MRSA) prevalence did not differ among sites; however, practitioners at the academic pediatric hospital EDs (92%) and the general academic ED (86%) were more likely to initiate empiric MRSA antibiotic therapy than the community site (71%), (p<0.0001). At discharge, children who received care at the community ED were more likely to be given a prescription for a narcotic (23%) and told to return to the ED for ongoing wound care (65%). Of all sites, the community ED also had the highest percentage of follow-up visits (37%). CONCLUSION: Abscess management varied among the three settings, with more conservative antibiotic selection and greater implementation of procedural sedation at academic centers and higher prescription rates for narcotics, self-referrals for ongoing care and patient follow-up visits at the community ED.

Independent and parallel recruitment of preexisting mechanisms underlying C4 photosynthesis.

C4 photosynthesis allows increased photosynthetic efficiency because carbon dioxide (CO2) is concentrated around the key enzyme RuBisCO. Leaves of C4 plants exhibit modified biochemistry, cell biology, and leaf development, but despite this complexity, C4 photosynthesis has evolved independently in at least 45 lineages of plants. We found that two independent lineages of C4 plant, whose last common ancestor predates the divergence of monocotyledons and dicotyledons about 180 million years ago, show conserved mechanisms controlling the expression of genes important for release of CO(2) around RuBisCO in bundle sheath (BS) cells. Orthologous genes from monocotyledonous and dicotyledonous C3 species also contained conserved regulatory elements that conferred BS specificity when placed into C4 species. We conclude that these conserved functional genetic elements likely facilitated the repeated evolution of C4 photosynthesis.

The role of proteins in C(3) plants prior to their recruitment into the C(4) pathway.

Our most productive crops and native vegetation use a modified version of photosynthesis known as the C(4) pathway. Leaves of C(4) crops have increased nitrogen and water use efficiencies compared with C(3) species. Although the modifications to leaves of C(4) plants are complex, their faster growth led to the proposal that C(4) photosynthesis should be installed in C(3) crops in order to increase yield potential. Typically, a limited set of proteins become restricted to mesophyll or bundle sheath cells, and this allows CO(2) to be concentrated around the primary carboxylase RuBisCO. The role that these proteins play in C(3) species prior to their recruitment into the C(4) pathway is addressed here. Understanding the role of these proteins in C(3) plants is likely to be of use in predicting how the metabolism of a C(3) leaf will alter as components of the C(4) pathway are introduced as part of efforts to install characteristics of C(4) photosynthesis in leaves of C(3) crops.

Agrobacterium tumefaciens-mediated transformation of Cleome gynandra L., a C(4) dicotyledon that is closely related to Arabidopsis thaliana.

In leaves of most C(4) plants, the biochemistry of photosynthesis is partitioned between mesophyll and bundle sheath cells. In addition, their cell biology and development also differs from that in C(3) plants. We have a poor understanding of the mechanisms that generate the cell-specific accumulation of proteins used in the C(4) pathway, and there are few genes that have been shown to be important for the cell biology and development of C(4) leaves. To facilitate functional analysis of C(4) photosynthesis, and to enable knowledge from Arabidopsis thaliana to be translated to C(4) species, an Agrobacterium tumefaciens-mediated transformation protocol was developed for the C(4) species Cleome gynandra. A. tumefaciens, harbouring the binary vector SLJ1006, was used to transfer the uidA gene under the control of the CaMV 35S promoter into C. gynandra. Co-incubation of hypocotyls or cotyledons with SLJ1006 allowed efficient transfer of DNA into C. gynandra, and media that allowed callus production and then shoot regeneration were identified. Stable transformants of C. gynandra with detectable amounts of beta-glucuronidase (GUS) were produced at an efficiency of 14%. When driven by the CaMV 35S promoter, GUS was visible in all leaf cells, whereas uidA translationally fused to a CgRbcS gene generated GUS accumulation specifically in bundle sheath cells. This transformation procedure is the first for an NAD-ME type C(4) plant and should significantly accelerate the analysis of mechanisms underlying C(4) photosynthesis.