Pebble to the Metal: A Boulder Approach to Enrichment for Danio rerio.

Zebrafish are an established and widely used animal model, yet there is limited understanding of their welfare needs. Despite an increasing number of studies on zebrafish enrichment, in-tank environmental enrichment remains unpopular among researchers. This is due to perceived concerns over health/hygiene when it comes to introducing enrichment into the tank, although actual evidence for this is sparse. To accommodate this belief, regardless of veracity, we tested the potential benefits of enrichments presented outside the tank. Thus, we investigated the preferences and physiological stress of zebrafish with pictures of pebbles placed underneath the tank. We hypothesized that zebrafish would show a preference for enriched environments and have lower stress levels than barren housed zebrafish. In our first experiment, we housed zebrafish in a standard rack system and recorded their preference for visual access to a pebble picture, with two positive controls: visual access to conspecifics, and group housing. Using a crossover repeated-measures factorial design, we tested if the preference for visual access to pebbles was as strong as the preference for social contact. Zebrafish showed a strong preference for visual access to pebbles, equivalent to that for conspecifics. Then, in a second experiment, tank water cortisol was measured to assess chronic stress levels of zebrafish housed with or without a pebble picture under their tank, with group housing as a positive control. Cortisol levels were significantly reduced in zebrafish housed with pebble pictures, as were cortisol levels in group housed zebrafish. In fact, single housed zebrafish with pebble pictures showed the same cortisol levels as group housed zebrafish without pebble pictures. Thus, the use of an under-tank pebble picture was as beneficial as being group housed, effectively compensating for the stress of single housing. Pebble picture enrichment had an additive effect with group housing, where group housed zebrafish with pebble pictures had the lowest cortisol levels of any treatment group.

Age-dependent changes in the expression of regulatory cell surface ligands in activated human T-cells.

BACKGROUND: The immune system consists of multiple preformed and more specific adaptive immune responses, which are all subject to both positive and negative regulation. Programmed cell death protein 1 (PD-1) is a cell surface ligand implicated in the induction of anergy, Inducible T-cell Costimulator (ICOS) plays a stimulatory role in the development of both CD4+ and CD8+ T-cells, Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4) plays a role in inhibitory regulation of T-cell activity, and T cell immunoglobulin and mucin protein 3 (Tim-3) has been described as a negative regulatory molecule in CD4+ helper type 1 cells and CD8+ cytotoxic type 1 cells. Each of these ligands is induced with T-cell activation allowing greater opportunity to have a regulatory role. RESULTS: Flow cytometry was used to quantitate the expression of PD-1, ICOS, CTLA-4 and Tim-3 in human T-cells from geriatric and younger subjects both at baseline and after in vitro induction by mitogen. The magnitude of expression of the molecules increased significantly on activated blasts after mitogen stimulation compared to their baseline levels in resting cells. The increase in CTLA-4 expressing CD8+ T-cells was significantly higher after in vitro induction in older persons, while the increase in cells expressing Tim-3 and PD-1 was significantly reduced. In CD4+ T-cells, a greater increase in CTLA-4 expressing cells in older persons was the only difference between the age groups. CONCLUSIONS: We found several significant changes in the older individuals in regulatory elements of the adaptive immune system that occur particularly after immune activation. These differences could have ramifications to autoimmunity as well as immunology against infection and tumors.

Variation in diagnosis of compartment syndrome by surgeons treating tibial shaft fractures.

BACKGROUND: It is agreed that missed compartment syndrome is associated with significant morbidity, but controversy regarding its diagnosis remains. To our knowledge, no one has analyzed the effect of individual surgeon variation on the diagnosis of compartment syndrome. METHODS: We analyzed a consecutive cohort of patients with tibial shaft fractures at our level I trauma center (n = 386 fractures). We identified all patients who were diagnosed as having compartment syndrome and who therefore underwent fasciotomy. The surgeon of record for each patient was recorded. Surgeons took call on random nights. All the surgeons were full-time orthopedic trauma surgeons. Patients with "prophylactic" fasciotomies were not included. Results were analyzed by conducting analysis of variance and the Kruskal-Wallis H test. RESULTS: Even though all the surgeons practiced at the same hospital during the same time period, wide variation existed in the rate of diagnosis and treatment of compartment syndrome. The rate ranged from a maximum of 24% to a minimum of 2% of the tibial fractures being diagnosed with compartment syndrome, depending on the surgeon. The differences were highly statistically significant (p < 0.005, Kruskal-Wallis H test). The surgeons' use of compartment pressure checks also varied (p < 0.05, Kruskal-Wallis H test) and seemed to approximately parallel the rate of compartment syndrome diagnosis. CONCLUSIONS: The diagnosis of compartment syndrome is difficult, and the data reported herein show that significant practice variation is likely, even within a single institution. It is unknown what the "true" rate of compartment syndrome should be, considering that a rate that is too high indicates unnecessary surgery and a rate that is too low means missing a devastating injury. Our data indicate lack of consensus in practice regarding the diagnosis of compartment syndrome, even at a high-volume level I trauma center, and emphasize the possibility of false-positive results of compartment pressure checks in clinical practice.

Staffing Model for Radiation Therapists in Ontario.

PURPOSE: The Cancer Care Ontario's (CCO) Radiation Program Leadership tasked the Radiation Therapy Professional Advisory Committee (RTPAC) to develop a radiation therapist (RT) staffing model to support current radiation therapy practice. BACKGROUND: A 1999 RT staffing model was outdated. Limitations included: (1) the inability to keep pace with advanced treatment planning and/or delivery techniques, (2) the exclusion of staffing for brachytherapy and orthovoltage, and (3) the omission of vital patient safety activities that are required to support clinical practices. METHODS: The RTPAC used a comprehensive scientific methodology to develop the new staffing model. A thorough literature review was completed, and an evidence-based model was developed. A unique creativity tool, the simplex process, was used to identify all the RTs' domains of practice that are integral for professional practice. All domains identified were included in the recommended staffing model. RESULTS: The staffing model recommends basing the number of RTs on equipment and associated clinical activities. The following staffing numbers are recommended: (1) linear accelerators: 4 full-time equivalent (FTEs) RTs per 10-hour day, (2) brachytherapy: 3 FTEs/8-hour day, (3) orthovoltage: 3 FTEs/8-hour day, (4) CT simulator: 3 FTEs/8-hour day and 4 FTEs/10-hour day, (5) dosimetry: 1 FTE/325 courses per year, (6) radiation oncology systems support and technology development implementation: 1 FTE/4 linear accelerator, (7) administration and education: 1 manager, 1 FTE supervisor/30 staff, 1 FTE professional practice leader/8 linear accelerators, 1 FTE staff educator/8 linear accelerators, 1 FTE undergraduate educator/8-10 students, and (8) additional 20% FTEs of the total for vacation, sick time, maternity leaves, and other leaves. CONCLUSIONS: The recommended staffing model is now more suitable for today's radiation therapy profession by addressing the domains of practice and clinical activities. Further research includes monitoring performance indicators annually to ensure that the staffing model is current. These indicators include wait times, access to care, radiation incidents, technological advances, and the quality of work-life of RTs.

How often does open reduction and internal fixation of geriatric acetabular fractures lead to hip arthroplasty?

OBJECTIVES: We hypothesized that open reduction and internal fixation (ORIF) of displaced acetabular fractures in geriatric patients result in a low rate of conversion to hip arthroplasty and satisfactory hip-specific validated outcome scores at medium-term follow-up. DESIGN: Retrospective review. SETTING: Level I trauma center. PATIENTS: One hundred forty-seven consecutive patients who were 60 years or older who had acetabular fractures were treated at our center from 2001 through 2006. During this time period, fractures meeting operative criteria were treated with ORIF unless medical conditions warranted nonoperative treatment. Twenty-nine patients were lost to follow-up, 46 were deceased, and 11 declined to participate, leaving 61 potential patients for inclusion, 46 of whom were treated with ORIF (average follow-up, 4.4 years; range, 1.1-8.0 years). INTERVENTION: Standardized telephone interviews included hip-specific questions and validated outcome measures. MAIN OUTCOME MEASUREMENTS: Rates of conversion to hip arthroplasty and hip-specific validated outcome scores. RESULTS: Among 46 patients treated with ORIF (15 others were treated nonoperatively or with percutaneous screw fixation), 28% underwent hip arthroplasty an average 2.5 years after injury (range, 0.4-5.5 years) and had an average Western Ontario and McMaster Universities Index of Osteoarthritis score of 17 (range, 0-56; n = 38). This score is similar to or better than the typical scores after elective arthroplasty for arthritis and much better than the scores for patients with established arthritis (P < 0.05). The average SF-8 Health Survey physical component score was 46.1 (range, 31-62), similar to US population norms for the geriatric age group (P > 0.20). CONCLUSIONS: Few data exist regarding the treatment outcomes for geriatric acetabular fractures. It is difficult for clinicians to decide among ORIF, percutaneous fixation, acute arthroplasty, and nonoperative treatment. Our protocol of mostly ORIF showed a high 1-year mortality rate of 25% and a rate of conversion to arthroplasty after ORIF of 28%. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Are bilateral femoral fractures no longer a marker for death?

OBJECTIVES: To determine whether previously reported high mortality rates associated with bilateral femoral fractures have decreased over time. DESIGN: Retrospective review. SETTING: Urban academic trauma center. STUDY GROUP: 54 adults with bilateral femoral fractures treated at our center from 2000 to 2006. The 108 fractures were initially treated with external fixation (11%), reamed antegrade nailing (23%), and reamed retrograde nailing (67%). Unilateral control group: 461 patients with unilateral femoral fractures treated at our center from 2002 to 2005. INTERVENTION: Univariate analysis compared our results with those of a published historical control group from the same center approximately 15 years ago (study period, 1984-1990). MAIN OUTCOME MEASUREMENTS: Mortality rates. RESULTS: We noted marked differences between the current mortality rate associated with bilateral femoral fractures and that of the historical control group. The mortality rate decreased over time at our center for both bilateral (26%-7%, P = 0.002) and unilateral (12%-2%, P = 0.0001) fractures. Mortality rates were still significantly higher (P = 0.037) for bilateral (7%) than for unilateral (2%) fractures. CONCLUSIONS: Mortality rates and Injury Severity Scores were reduced for bilateral and unilateral femoral fractures compared with data reported 15 years ago from the same center. The improved outcome might be related in part to changes in resuscitation, triage, intensive care, and orthopaedic management of the patients. However, considering that the Injury Severity Score also significantly decreased, the improvement might have occurred because of changes in injury patterns, perhaps secondary to improved safety features in motor vehicles. LEVEL OF EVIDENCE: Prognostic level III. See instructions for authors for a complete description of levels of evidence.

Do one-time intracompartmental pressure measurements have a high false-positive rate in diagnosing compartment syndrome?

BACKGROUND: Intracompartmental pressure measurements are frequently used in the diagnosis of compartment syndrome, particularly in patients with equivocal or limited physical examination findings. Little clinical work has been done to validate the clinical use of intracompartmental pressures or identify associated false-positive rates. We hypothesized that diagnosis of compartment syndrome based on one-time pressure measurements alone is associated with a high false-positive rate. METHODS: Forty-eight consecutive patients with tibial shaft fractures who were not suspected of having compartment syndrome based on physical examinations were prospectively enrolled. Pressure measurements were obtained in all four compartments at a single point in time immediately after induction of anesthesia using a pressure-monitoring device. Preoperative and intraoperative blood pressure measurements were recorded. The same standardized examination was performed by the attending surgeon preoperatively, postoperatively, and during clinical follow-up for 6 months to assess clinical evidence of acute or late compartment syndrome. RESULTS: No clinical evidence of compartment syndrome was observed postoperatively or during follow-up until 6 months after injury. Using the accepted criteria of delta P of 30 mm Hg from preoperative diastolic blood pressure, 35% of cases (n = 16; 95% confidence interval, 21.5-48.5%) met criteria for compartment syndrome. Raising the threshold to delta P of 20 mm Hg reduced the false-positive rate to 24% (n = 11; 95% confidence interval, 11.1-34.9%). Twenty-two percent (n = 10; 95% confidence interval, 9.5-32.5%) exceeded absolute pressure of 45 mm Hg. CONCLUSION: A 35% false-positive rate was found for the diagnosis of compartment syndrome in patients with tibial shaft fractures who were not thought to have compartment syndrome by using currently accepted criteria for diagnosis based solely on one-time compartment pressure measurements. Our data suggest that reliance on one-time intracompartmental pressure measurements can overestimate the rate of compartment syndrome and raise concern regarding unnecessary fasciotomies. LEVEL OF EVIDENCE: Diagnostic study, level II.

Perioperative supplemental oxygen to reduce surgical site infection after open fixation of high-risk fractures: a randomized controlled pilot trial.

BACKGROUND: Higher concentrations of fraction of inspired oxygen (FIO2) have been shown to be associated with lower risk for surgical site infection in multiple studies outside the domain of orthopedic surgery. We evaluated the efficacy of high FIO2 administered during the perioperative period to reduce the rate of surgical site infection after open fixation of lower-extremity fractures at high risk of infection. METHODS: We conducted a randomized controlled, parallel design, double-blind study. Patients sustaining high-energy tibial plateau, tibial pilon, and calcaneus fractures treated in a staged fashion were selected for enrollment because these injuries are associated with high risk of infection. The study population included 222 patients with 235 fractures. Consenting patients were randomized by random number sequence to either the treatment or the control group. Treatment group patients received 80% FIO2 intraoperatively and for 2 hours afterward. Control group patients received 30% FIO2 during the same period. Surgeons, patients, and personnel who performed wound assessments were blinded to group assignment. The primary outcome measure was surgical site infection as defined by the Centers for Disease Control criteria for postoperative wound infection. RESULTS: The overall rates of postoperative surgical site infection were 12% (14 of 119 fractures) in the treatment group and 16% (19 of 116 fractures) in the control group (p = 0.31). Multivariate analysis, accounting for risk factors for infection, yielded the closest to a statistically significant reduction in the odds of infection with treatment (odds ratio, 0.54; p = 0.17). No treatment-associated events were observed. CONCLUSION: Use of a high concentration of FIO2 during the perioperative period is safe and shows a trend toward reduction of surgical site infection in patients undergoing open operative fixation of high-energy traumatic lower-extremity fractures. Further study in a larger patient population is indicated. LEVEL OF EVIDENCE: Therapeutic study, level III.

Predictive model for surgical site infection risk after surgery for high-energy lower-extremity fractures: development of the risk of infection in orthopedic trauma surgery score.

BACKGROUND: Current infection risk scores are not designed to predict the likelihood of surgical site infection after orthopedic fracture surgery. We hypothesized that the National Nosocomial Infections Surveillance (NNIS) System and the Study on the Efficacy of Nosocomial Infection Control (SENIC) scores are not predictive of infection after orthopedic fracture surgery and that risk factors for infection can be identified and a new score created (Emerg Infect Dis. 2003;9:196-203). METHODS: We conducted a secondary analysis of data from a trial involving internal fixation of 235 tibial plateau, pilon, and calcaneus fractures treated between 2007 and 2010 at a Level I trauma center. The predictive value of the NNIS System and SENIC scores was evaluated based on areas under the receiver operating characteristic (ROC) curve. Bivariate and multiple logistic regression analyses were used to build an improved prediction model, creating the Risk of Infection in Orthopedic Trauma Surgery (RIOTS) score. The predictive value of the RIOTS score was evaluated via the ROC curve. RESULTS: NNIS System and SENIC scores were not predictive of surgical site infection after orthopedic fracture surgery. In our final regression model, the relative odds of infection among patients with AO [Arbeitsgemeinschaft für Osteosynthesefragen] type C3 or Sanders type 4 fractures compared with fractures of lower classification was 5.40. American Society of Anesthesiologists class 3 or higher and body mass index less than 30 were also predictive of infection, with odds ratios of 2.87 and 3.49, respectively. The area under the ROC curve for the RIOTS score was 0.75, significantly higher than the areas for the NNIS System and SENIC scores. CONCLUSION: The NNIS System and SENIC scores were not useful in predicting the risk of infection after fixation of fractures. We propose a new score that incorporates fracture classification, American Society of Anesthesiologists classification, and body mass index as predictors of infection. LEVEL OF EVIDENCE: Prognostic study, level II.

A Comparison of Perceptual and Reported Errors in Radiation Therapy.

PURPOSE: The aims of this study are to investigate error perceptions in radiation therapy (RT), to analyze 13 years of reported errors by type and location, and to identify the similarities and differences between perceptual and reported errors. METHOD: Close-ended surveys were distributed to radiation therapists, RT students, medical physicists, and medical physicist residents at a large cancer centre. Two areas of relevance were: (1) to select the five most common categories of errors in radiation therapy and (2) to rank the many different stages where errors can be made in radiation therapy. The purpose of the survey was to investigate error perceptions based on type of error and location. The survey findings were compared to reported errors tabulated over 13 years (1998-2010) as collected by the Radiation Therapy Quality Assurance Committee on site. Frequency of survey responses and actual error occurrences were ranked and compared. Survey responses were analyzed by demographics based on gender, profession, and levels of experience. Statistical tests were also performed. RESULTS: The total response rate for the survey was 45% (58 of 130 respondents). There is a consensus that documentation errors and treatment delivery errors occur most frequently. However, errors relating to bolus, geographic miss, and positioning device were outstanding in the perception of errors. Categories with high error frequencies for reported errors included field size, shielding, and monitor units calculation. There were no significant differences in survey responses based on demographics. CONCLUSION: The incongruence in certain types of errors between those perceived and those reported is alarming. When there is lack of awareness, the errors can be even more prone to occur. Patient safety culture starts from the individual; hence, understanding staff perception is critical in managing a quality assurance program. As technological advancements decrease certain errors, they may also have the potential to introduce new types of errors. Therefore, the last line of defense in any system remains qualified and attentive staff members.

Investigation of the human stem cell factor KIT ligand gene, KITLG, in women with 46,XX spontaneous premature ovarian failure.

OBJECTIVE: To investigate mutations in the human KIT ligand gene (KITLG) gene as a mechanism of 46,XX spontaneous premature ovarian failure. The human KIT ligand gene, known also as human stem cell factor, is the ligand of the c-kit transmembrane tyrosine kinase receptor (KIT). This ligand-receptor interaction is known to play important roles in mouse germ cell migration and proliferation. DESIGN: Cross-sectional study. SETTING: Clinical research center. PATIENT(S): Forty women with 46,XX spontaneous premature ovarian failure. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Single-stranded conformational polymorphism analysis and DNA sequencing. RESULT(S): We found one nucleotide change of the KITLG coding region (811G-->T) that led to an alteration of the amino acid composition of the KITLG protein in one Caucasian patient (Asp210Tyr). However, we found the same alteration in two normal control Caucasian samples. Three nucleotide substitutions were found in the noncoding exon of KITLG (exon 10). We also identified two intronic polymorphisms. Thus, we did not identify a single significant mutation in the coding region of the KITLG gene in any of 40 patients (upper 95% confidence limit is 7.2%). CONCLUSION(S): Mutations in the coding regions of the KITLG gene appear not to be a common cause of 46,XX spontaneous premature ovarian failure in North American women.