Incidence of Tibial Tubercle Fractures in Patients With and Without Osgood-Schlatter Disease.

BACKGROUND: Patients with Osgood-Schlatter disease (OSD) may be at increased risk of tibial tubercle fractures due to an underlying weakness of the tibial tubercle apophysis relative to the patellar tendon as a result of repetitive microtrauma. HYPOTHESIS/PURPOSE: The purpose of this study is to analyze the incidence of tibial tubercle fractures in patients with and without Osgood-Schlatter disease. We hypothesized that the incidence of tibial tubercle fractures would be higher in patients with Osgood-Schlatter disease. METHODS: A retrospective cohort analysis of the PearlDiver database was performed by querying all patients diagnosed with Osgood-Schlatter disease between January 2010 and October 2022. An OSD cohort of 146,672 patients was captured using International Classification of Diseases, Ninth Revision (ICD-9), Tenth Revision (ICD-10) billing codes, and age as inclusion/exclusion criteria. The Student t test and the χ2 analyses were used to compare the demographics and obesity between the OSD and control cohorts. Multivariable logistic regressions, controlling for residual differences in age, sex, and obesity, were used to compare rates of tibial tubercle fractures. RESULTS: Patients with a recent history of OSD were found to have higher rates of tibial tubercle fractures than the control group at all measured time points (P<0.001). The 1-year rate of tibial tubercle fractures was 0.62% in the OSD group. The incidence of tibial tubercle fractures in the OSD group was 627.3 cases per 100,000 person-years compared with 42.7 cases per 100,000 person-years in the control group (P<0.001). Male sex and obesity were also associated with an increased risk of sustaining a tibial tubercle fracture within these patient populations (P<0.001). CONCLUSION: We report a significantly higher incidence of tibial tubercle fractures among patients with OSD compared with controls. This increase was most significant at 1 month following OSD diagnosis, however, held true for all measured time points. In addition, male patients and those with obesity were also noted to have increased incidence of tibial tubercle fractures regardless of an OSD diagnosis.

Cortical Trajectory Versus Traditional Pedicle Screw Trajectory in Open Transforaminal Lumbar Interbody Fusion: Meta-analysis of Complications and Clinical Outcomes.

BACKGROUND: Lumbar degenerative disease imposes a substantial burden on global healthcare expenditures. Transforaminal lumbar interbody fusion (TLIF) utilizing either traditional trajectory (TT) pedicle screws or cortical bone trajectory (CT) pedicle screws have become increasingly common. This meta-analysis evaluates the outcomes and safety of open TLIF with TT compared to CT. METHODS: PubMed, Cochrane, and Google Scholar (pages 1-20) were explored until April 2024. The studied outcomes included complications, revision surgeries, operative room (OR) time, estimated blood loss (EBL), length of hospital stay (LOS), incision length, Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and the Japanese Orthopedic Association (JOA) score. RESULTS: Five studies were included in this meta-analysis. A total of 770 patients undergoing TLIF were included, with 415 in the CT group and 355 in the TT group. No statistically significant differences were found in the rate of overall complications, including specific complications, the rate of revision surgeries, PROMS scores, OR time, and EBL. However, the CT group demonstrated shorter LOS (p=0.05), and shorter incision lengths (p<.001) compared to the TT group. CONCLUSION: Both TT and CT techniques in TLIF procedures demonstrated comparable rates of complications, reoperations, and PROMs. Despite similar OR times and EBL, the CT group exhibited shorter incision lengths, and shorter LOS compared to the TT group. Both cortical and traditional trajectory pedicle screws are safe and effective options for TLIF. There are potential benefits to CT such as shorter incision and LOS, although TT remains an essential tool for spinal instrumentation techniques.

Decreased prevalence of new-onset adhesive capsulitis in patients prescribed angiotensin receptor blockers.

BACKGROUND: Angiotensin receptor blockers (ARBs) are commonly prescribed antihypertensive agents that have well-known antifibrotic properties. The purpose of this study was to examine the association between ARB use and the rates of new-onset adhesive capsulitis as well as adhesive capsulitis requiring operative treatment. METHODS: Using a large national insurance database, a randomly generated cohort of patients with at least 3 continuous months of ARB use between January 2010 and December 2019 (n = 1,000,000) was compared to a separate randomly generated cohort without ARB use (n = 3,000,000). Rates of newly diagnosed adhesive capsulitis and associated manipulation under anesthesia (MUA) and/or arthroscopic capsulotomy were calculated over a 1- and 2-year period following the completion of at least 3 continuous months of ARB therapy. Rates were compared using multivariable logistic regression to control for demographics and comorbidities. Both unadjusted and adjusted odds ratios and 95% confidence intervals were calculated and reported for each comparison. Statistical significance was set at P <.05. RESULTS: The mean age in the ARB cohort was 61.8 years (standard deviation [SD] = 10.0), whereas in the control cohort, it was 54.8 years (SD = 12.3) (P < .001). The ARB cohort had significantly lower rates of newly diagnosed adhesive capsulitis compared with the control cohort at both 1 year (0.15% vs. 0.55%, P < .001) and 2 years (0.3% vs. 0.78%, P < .001). Similar findings were observed for the arthroscopic capsular release/MUA cohort associated with adhesive capsulitis. After adjusting for confounding factors, the lower rates of adhesive capsulitis and arthroscopic capsular release/MUA associated with adhesive capsulitis in the ARB cohort remained statistically significant (P < .001). CONCLUSION: Patients prescribed ARBs experienced a decreased rate of newly diagnosed adhesive capsulitis, as well as adhesive capsulitis requiring surgical intervention when compared to a control cohort. These findings suggest a potential protective effect of ARBs against the development of adhesive capsulitis. Further investigations are warranted to elucidate the underlying mechanisms and establish a causal relationship.

Lipid Tales: Optimizing Arylomycin Membrane Anchors.

Multidrug-resistant bacteria are spreading at alarming rates, and despite extensive efforts, no new antibiotic class with activity against Gram-negative bacteria has been approved in over 50 years. LepB inhibitors (LepBi) based on the arylomycin class of natural products are a novel class of antibiotics and function by inhibiting the bacterial type I signal peptidase (SPase) in Gram-negative bacteria. One critical aspect of LepBi development involves optimization of the membrane-anchored lipophilic portion of the molecule. We therefore developed an approach that assesses the effect of this portion on the complicated equilibria of plasma protein binding, crossing the outer membrane of Gram-negative bacteria and anchoring in the bacterial inner membrane to facilitate SPase binding. Our findings provide important insights into the development of antibacterial agents where the target is associated with the inner membrane of Gram-negative bacteria.

Development and application of a scoring system for septum injuries in beef calves with and without a nose flap.

The weaning period is a stressful time for beef calves because they must quickly gain independence from their dam. Gradual methods of weaning, such as when the calf is fitted with a nose flap to prevent suckling, are known to reduce the behavioral and physiological indicators of stress. Nose flaps are held in place by the nasal septum and are worn for 4 to 7 d. In the present study, the objectives were to 1) identify if a plastic nose flap worn for 7 d caused nasal injuries, (2) identify if factors like calf body weight or septum size predict injuries or flap loss, and (3) create a scoring system that could reliably score wound characteristics. Eighty-two (N = 82) Angus and Angus-Hereford crossbred beef calves were randomly assigned to 'Flap' or 'No Flap' treatments. Calves weighed 247 ±â€…29 kg and those with a flap had septums that were 39 ±â€…2 mm (mean ±â€…SD). Images were taken of each nostril before flap insertion, on the day of removal, and 6 d after removal. Wounds were scored for the presence/absence of three characteristics in either nostril: damage (tissue where the flap rested was a different color than surrounding nostril), impression (edges of the wound were clearly raised or sunken), and blood. One trained observer scored a subset of photos (N = 64) twice, in a consistent manner for all three characteristics (damage, impression, and blood; 97%, 91%, and 100% agreement between 1st and 2nd evaluations, respectively), indicating that our system is repeatable. Thirty-two percent of calves in the Flap treatment lost their flap before the day of removal. No calves in the No Flap treatment were injured. All animals that kept their flap in for 7 d had damage and impressions in at least one nostril and 86% of calves had blood present immediately after nose flap removal (P ≤ 0.001 compared to No Flap) indicating that the flaps altered the nasal tissue and created open wounds. Six d after flap removal, 100% still had visible damage, 64% had impressions, and 29% had blood, indicating that while damage is longer lasting, wounds can start to repair after the flap is removed. Injuries were prevalent in all calves, thus there was no relationship between calf size (body weight or septum width) on these wounds (P ≥ 0.374). Body weight or septum size did not differ (P ≥ 0.489) between calves that kept or lost their flap. Injuries inflicted from a nose flap may counteract the previously documented benefits of this method of weaning, making it less advantageous than alternatives and raise concerns about other uses of these devices in other contexts.

Venom phenotype conservation suggests integrated specialization in a lizard-eating snake.

Biological specialization reduces the size of niche space while increasing efficiency in the use of available resources. Specialization often leads to phenotypic changes via natural selection aligning with niche space constraints. Commonly observed changes are in size, shape, behavior, and traits associated with feeding. One often selected trait for dietary specialization is venom, which, in snakes, often shows variation dependent on diet across and within species. The Neotropical Blunt-headed Treesnake (Imantodes cenchoa) is a highly specialized, rear-fanged, arboreal, lizard hunter that displays a long thin body, enlarged eyes, and a large Duvernoy's gland. However, toxin characterization of I. cenchoa has never been completed. Here, we use RNA-seq and mass spectrometry to assemble, annotate, and analyze the venom gland transcriptomes of four I. cenchoa from across their range. We find a lack of significant venom variation at the sequence and expression levels, suggesting venom conservation across the species. We propose this conservation provides evidence of a specialized venom repertoire, adapted to maximize efficiency of capturing and processing lizards. Importantly, this study provides the most complete venom gland transcriptomes of I. cenchoa and evidence of venom specialization in a rear-fanged snake, giving insight into selective pressures of venom across all snake species.

On-person adaptive evolution of Staphylococcus aureus during treatment for atopic dermatitis.

The opportunistic pathogen Staphylococcus aureus frequently colonizes the inflamed skin of people with atopic dermatitis (AD) and worsens disease severity by promoting skin damage. Here, we show, by longitudinally tracking 23 children treated for AD, that S. aureus adapts via de novo mutations during colonization. Each patient's S. aureus population is dominated by a single lineage, with infrequent invasion by distant lineages. Mutations emerge within each lineage at rates similar to those of S. aureus in other contexts. Some variants spread across the body within months, with signatures of adaptive evolution. Most strikingly, mutations in capsule synthesis gene capD underwent parallel evolution in one patient and across-body sweeps in two patients. We confirm that capD negativity is more common in AD than in other contexts, via reanalysis of S. aureus genomes from 276 people. Together, these findings highlight the importance of the mutation level when dissecting the role of microbes in complex disease.

Venom phenotype conservation suggests integrated specialization in a lizard-eating snake

Biological specialization reduces the size of niche space while increasing efficiency in the use of available resources. Specialization often leads to phenotypic changes via natural selection aligning with niche space constraints. Commonly observed changes are in size, shape, behavior, and traits associated with feeding. One often selected trait for dietary specialization is venom, which, in snakes, often shows variation dependent on diet across and within species. The Neotropical Blunt-headed Treesnake (Imantodes cenchoa) is a highly specialized, rear-fanged, arboreal, lizard hunter that displays a long thin body, enlarged eyes, and a large Duvernoy's gland. However, toxin characterization of I. cenchoa has never been completed. Here, we use RNA-seq and mass spectrometry to assemble, annotate, and analyze the venom gland transcriptomes of four I. cenchoa from across their range. We find a lack of significant venom variation at the sequence and expression levels, suggesting venom conservation across the species. We propose this conservation provides evidence of a specialized venom repertoire, adapted to maximize efficiency of capturing and processing lizards. Importantly, this study provides the most complete venom gland transcriptomes of I. cenchoa and evidence of venom specialization in a rear-fanged snake, giving insight into selective pressures of venom across all snake species.

Evaluation of endogenous and therapeutic 25-hydroxycholesterols in murine models of pulmonary SARS-CoV-2 infection.

Oxysterols (i.e., oxidized cholesterol species) have complex roles in biology. 25-hydroxycholesterol (25HC), a product of activity of cholesterol-25-hydroxylase (CH25H) upon cholesterol, has recently been shown to be broadly antiviral, suggesting therapeutic potential against SARS-CoV-2. However, 25HC can also amplify inflammation and tissue injury and be converted by CYP7B1 to 7α,25HC, a lipid with chemoattractant activity via the G protein-coupled receptor, EBI2/GPR183. Here, using in vitro studies and two different murine models of SARS-CoV-2 infection, we investigate the effects of these two oxysterols on SARS-CoV-2 pneumonia. We show that while 25HC and enantiomeric-25HC are antiviral in vitro against human endemic coronavirus-229E, they did not inhibit SARS-CoV-2; nor did supplemental 25HC reduce pulmonary SARS-CoV-2 titers in the K18-human ACE2 mouse model in vivo. 25HC treatment also did not alter immune cell influx into the airway, airspace cytokines, lung pathology, weight loss, symptoms, or survival but was associated with increased airspace albumin, an indicator of microvascular injury, and increased plasma pro-inflammatory cytokines. Conversely, mice treated with the EBI2/GPR183 inhibitor NIBR189 displayed a modest increase in lung viral load only at late time points, but no change in weight loss. Consistent with these findings, although Ch25h was upregulated in the lungs of SARS-CoV-2-infected WT mice, lung viral titers and weight loss in Ch25h-/- and Gpr183-/- mice infected with the beta variant were similar to control animals. Taken together, endogenous 25-hydroxycholesterols do not significantly regulate early SARS-CoV-2 replication or pathogenesis and supplemental 25HC may have pro-injury rather than therapeutic effects in SARS-CoV-2 pneumonia.

Compact thermal imager: a flight demonstration of infrared technology for Earth observations.

During 2019, an infrared camera, the compact thermal imager (CTI), recorded 15 million images of the Earth from the International Space Station. CTI is based on strained-layer superlattice (SLS) detector technology. The camera covered the spectral range from 3 to 11 µm in two spectral channels, 3.3-5.4 and 7.8-10.7 µm. Individual image frames were 26×21km2 projected on the ground, with 82 m pixel resolution. A frame time of 2.54 s created continuous image swaths with a 13% along-track image overlap. Upper limits determined on the ground and in flight for the electronic offset, read noise, and dark current demonstrated the stability of the SLS detector and camera over many months. Temperature calibration was established using a combination of preflight and in-flight measurements. A narrowband approximation of temperature as a function of photon counts produced an analytic relationship covering a temperature range of 0°-400°C. Examples of CTI images illustrate temperature retrievals over sea ice, urban and agricultural areas, desert, and wildfires.

Osteoporosis and Fragility Fractures.

Osteoporosis and fragility fractures (FFs) are closely intertwined as the former is a common predisposing factor to the latter. This causal relationship is due to low bone density of osteoporosis and compromised bone microarchitecture, leading to structural failure, decreased ability to withstand applied stresses, and increased propensity to fracture. Osteoporosis can be idiopathic or due to a variety of secondary causes, and numerous treatment strategies are available. FFs are common injuries among the elderly and are caused by factors both intrinsic and extrinsic to the patient. The clinical and economic significances of osteoporosis and FFs are substantial, with considerable associated morbidity and mortality, and billions spent on healthcare expenditures in the US annually. Osteoporosis and FFs are two of the most important topics related to fracture liaison services (FLSs), and their understanding is integral to appreciating the benefits an FLS can provide for patients and providers.

Research interests, experience, and training of Community Health Workers: a mixed Method Approach.

The Affordable Care Act includes a call for community health care workers (CHWs) to be integrated into health care delivery systems to improve health care quality. In recent years, there have been increasing calls for community-based participatory research (CBPR) and patient-centered outcomes research (PCOR), as such types of research hold much potential for identifying interventions to reduce health and health care disparities. Yet, little is known about the research training, knowledge, experience, and even interest of CHWs in these types of research or in health research in general (HR). Thus, the purposes of this study include determining if there are differences between participating CHWs (N = 202) in their levels of training, knowledge, experience, and interest in relation to CBPR, PCOR and HR. Findings suggest that certified CHWs, as compared to non-certified CHWs, have significantly higher knowledge levels across all three types of research (ß = 1.3, p = .007). Additionally, participants had significantly higher knowledge of HR compared to CBPR (ß = 0.5, p = .015), but not higher than their knowledge of PCOR (p > .5). Qualitative data analyses performed to determine research areas of interest among the participating CHWs resulted in eighteen major research interest themes. Examples of these major themes are chronic illness (n = 95), health promotion (n = 39), healthcare services and administration (n = 30), mental health (n = 29), and research evaluation and methodology (n = 26). Together, the findings suggest that though CHWs have an interest in a wide range of health research areas, they could benefit from research trainings tailored to their responsibilities and interests.

World association for the advancement of veterinary parasitology (WAAVP): Second edition of guidelines for evaluating the efficacy of anthelmintics in poultry.

This revision of the original poultry guidelines has been prepared to assist in the planning, conduct and interpretation of studies designed to assess the anthelmintic efficacy of drugs (newly discovered or currently used) against helminth parasites of chickens and turkeys. The original set of poultry guidelines was published in 2003. The current version provides an update on procedures to study and quantify the most important helminth parasites of chickens and turkeys, and to integrate these poultry guidelines with a new series of general, reflective and host-specific guidelines relative to assessing anthelmintic efficacy in production and companion animals. General considerations required for the conduct of studies designed to evaluate anthelmintics regardless of animal host such as the selection of study animals, animal housing, feeding, study design, record keeping and statistical analysis are for the most part provided in the newly published general guidelines. Taken together, the general and poultry guidelines should help investigators and others design and conduct studies and evaluate data concerned with determining the efficacy and safety of anthelmintics in chickens and turkeys. Additionally, this revision draws attention to several timely considerations inherent to anthelmintic evaluations such as the need to properly collect helminth specimens for subsequent determinations (e.g. species and stage verification, helminth genotyping). The investigations addressed herein, will most likely provide the very first public record of a new product's abilities to effectively reduce targeted, helminth infections in animals, and particular attention should be focused on study excellence and accuracy. Due to changes in consumer preferences, and new regulatory requirements, poultry husbandry, especially regarding laying hens, has changed immensely in many countries since the publication of the first poultry guidelines. These changes have generally allowed for a much greater exposure of birds to the source of helminth challenge (litter and fields as opposed to cages). Parasitic helminthiosis of poultry has therefore greatly increased in incidence and magnitude; changes that accentuate the need for more effective anthelmintic intervention and an update on the means of determining anthelmintic efficacy.

The Skin Microbiome of Patients With Atopic Dermatitis Normalizes Gradually During Treatment.

Background: Atopic dermatitis (AD) is characterized by an altered skin microbiome dominantly colonized by S. aureus. Standard treatment includes emollients, anti-inflammatory medications and antiseptics. Objectives: To characterize changes in the skin microbiome during treatment for AD. Methods: The skin microbiomes of children with moderate-to-severe AD and healthy children were investigated in a longitudinal prospective study. Patients with AD were randomized to receive either standard treatment with emollients and topical corticosteroids or standard treatment with the addition of dilute bleach baths (DBB) and sampled at four visits over a three-month period. At each visit, severity of AD was measured, swabs were taken from four body sites and the composition of the microbiome at those sites was assessed using 16S rRNA amplification. Results: We included 14 healthy controls and 28 patients. We found high relative abundances of S. aureus in patients, which correlated with AD severity and reduced apparent alpha diversity. As disease severity improved with treatment, the abundance of S. aureus decreased, gradually becoming more similar to the microbiomes of healthy controls. After treatment, patients who received DBB had a significantly lower abundance of S. aureus than those who received only standard treatment. Conclusions: There are clear differences in the skin microbiome of healthy controls and AD patients that diminish with treatment. After three months, the addition of DBB to standard treatment had significantly decreased the S. aureus burden, supporting its use as a therapeutic option. Further study in double-blinded trials is needed.

Assessing effects of dietary and milking frequency changes and injection of cabergoline during dry-off on hunger in dairy cows using 2 feed-thwarting tests.

We investigated the single and combined effects of 2 feeding levels (normal lactation diet vs. energy-reduced diet, both fed for ad libitum intake) and 2 daily milking frequencies (twice vs. once) during 1 wk before the dry-off day (d 0), as well as an intramuscular injection of either a dopamine agonist (cabergoline; Velactis, Ceva Santé Animale; labeled for use only with abrupt dry-off, e.g., no reduction in feeding level or milking frequency before the last milking) or saline after the last milking on d 0 on the feeding motivation of clinically healthy, loose-housed, pregnant, lactating Holstein cows. From d 0, all cows were fed the same dry-cow diet for ad libitum intake. Cows were subjected to 2 feed-thwarting tests, a test in the home pen using their diets (test A: d -6, -1, and 1; during 35 min when the feed bins were filled, but locked) and another test carried out in an adjacent pen in which access to concentrate provided in a familiar plastic box was blocked by a wire-mesh lid (test B: d -5 and 2). In test A, we recorded how often cows attempted to feed per 35 min, whether cows vocalized during the 35-min period, and latency to feed within 300 s after feed bins were unlocked. In test B, we recorded latency to approach either of 2 familiar boxes (the wire-mesh box and an identical open box with a small portion of concentrate) within 600 s and how often cows directed behaviors toward the wire-mesh box (number of occurences/5 min). On d -6 (test A), no clear differences in feeding motivation among treatments were found. On d -5 and -1, cows fed the energy-reduced diet displayed a higher probability of vocalizing (test A), were more than 50% quicker to feed (test A), were approximately 5× quicker to approach a box (test B), and directed 60% more behavior toward the wire-mesh box (test B) than cows fed the normal diet. Moreover, cows fed the energy-reduced diet attempted to feed approximately 75% more on d -1 compared with d -6 (test A). On d 2 (test B), cows previously fed the normal diet directed 40% more behavior toward the wire-mesh box than cows previously fed the energy-reduced diet. Reducing feeding level, either before or on the dry-off day, resulted in consistently increased feeding motivation, interpreted as a sign of hunger. No clear effects of change in milking frequency, singly or combined with reduced diet energy density, on feeding motivation were found before d 0. Whereas, on d 2, cows previously milked twice daily were quicker to approach a box than cows previously milked once daily. Cows injected with cabergoline attempted to feed more, but showed lower probability of vocalizing compared with saline-injected cows (d 1; test A), irrespective of treatment before d 0. The effects of cabergoline on feeding motivation are not easily interpreted and warrant further investigation. From a hunger perspective, reducing milking frequency rather than diet energy density seems to be a less negative management to reduce milk production before dry-off.

The causes and effects of indigenous C4 grass expansion into a hyper-diverse fynbos shrubland.

The cool season rainfall at our study site should favour C3 rather than C4 grasses. There are, however, several locations where C4 grasses have become dominant, suggesting that rainfall seasonality is not a constraint on distribution. Here, we explored the limitations on C4 grass distribution in a fynbos shrubland. Using δ13C values of SOM, we determined when these grasses had established. We also looked at the role of roads as conduits for establishment and asked what impact these grasses may have on fynbos species richness. We then conducted a field experiment designed to examine the extent to which soil moisture, nutrient availability, and competition with fynbos for resources influence the establishment and growth of the grasses. Finally using aerial photography, we explored the role of changes in land use on distribution. Our results showed that the establishment is recent, that roads may be acting as conduits, and that with establishment, there is a reduction in fynbos species richness and diversity. Disturbance and removing below-ground competition for resources open the system to establishment in wetter areas. This study is the first to look at the potential for C4 grasses expanding into cool season rainfall shrublands such as in Western Australia and South Africa. What is interesting about these results is that C4 grasses can establish and dominate in a cool season rainfall regime. Rather than temperature of the growing season, it is competition for resources from fynbos that prevents these grasses from encroaching.

Prevalence of Occult Infections in Posterior Instrumented Spinal Fusion.

STUDY DESIGN: This is a prospective observational study. OBJECTIVE: The aim of this study is to determine the rate of occult infection after instrumented spine surgery in presumed aseptic patients. SUMMARY OF BACKGROUND DATA: The reported incidence rate of delayed/occult infection determined by positive culture swabs after instrumented spine surgery in prospective studies is 0.2%-6.9%. However, this rate may be higher as delayed infections are challenging to diagnose. Fever can be absent and inflammatory markers are often normal. If indolent organisms exist in low concentrations surrounding the instrumentation, these organisms can possibly avoid detection and disrupt bone formation leading to instrumentation loosening, pain generation, and/or failure of a solid fusion. MATERIALS AND METHODS: This study included 50 consecutive presumed aseptic patients undergoing a posterior revision requiring removal of instrumentation at least 6 months following their index procedure. Common markers of infection were examined preoperatively. Multiple culture swabs were taken directly from the removed instrumentation and cultured for 14 days. RESULTS: Of the 50 patients, 19 (38%) were culture-positive (CP) for bacteria upon removal of their instrumentation, with 14 patients (28%) having ≥2 positive specimens of the same organism. The average length of time between the index procedure and the revision surgery was 4.55 years (range: 0.53-21 y). Polymicrobial infections were found in 26% (5/19) of CP patients. The most prevalent microorganism found was Propionibacterium acnes, in 63% (12/19) of CP patients. There was no significant difference between CP and culture-negative patients regarding preoperative markers for infection, age, or length between index and revision procedures. CONCLUSIONS: The results of this study indicate a positive culture rate of 38% in presumed aseptic patients who had previously undergone instrumented spine surgery. These results are consistent with other retrospective studies and are >6 times greater than any previous prospective study utilizing culture swabs. LEVEL OF EVIDENCE: Level-III.

Measuring behavior patterns and evaluating time-sampling methodology to characterize brush use in weaned beef cattle.

With growing interest in provision of brushes for cattle and the implications of brush use for behavioral development and welfare, there is a need to validate methodology for quantifying grooming behavior. Our objectives were to characterize patterns of brush use, including bouts, diurnal activity, and individual variability over 24-h periods, and to validate time-sampling methodologies to characterize these traits, including instantaneous recording at various time intervals and continuous recording for subsets of the day. Data sets from previous experiments involving steers (experiment 1; n = 18) and heifers (experiment 2; n = 64), consisting of start and end times of brush use continuously recorded from video, were used to analyze brush use. We extrapolated data sets representative of a range of instantaneous recording intervals and compared daily brush duration and bout characteristics with corresponding values from continuous recording using linear regression. To assess validity of sampling subsets of the day, we selected 2-h time periods representative of different functional parts of the day and compared hourly brush rates with continuous data using Spearman's rank order correlation (rs). Brush use was variable among individuals. All steers used the brush in experiment 1, but 17% (n = 11 of 64) of heifers in experiment 2 did not. Bout analysis revealed that individuals used the brush for an average of 7 to 8 brush bouts lasting 4 to 6 min, leading to an average of 24 and 36 min/d for experiments 1 and 2, respectively. Cattle used the brush mainly during daylight hours, with peaks around sunrise, sunset, and the afternoon. Instantaneous recording at intervals less than 1 to 3 min, depending on the experiment, provided good estimates of daily brush use duration (R2 > 0.95 and slope and intercept not different from 1 and 0, respectively), but intervals >3 min were less reliable. For bout characteristics, the intercept of the modeled line differed from 0 for most recording intervals for both experiments, and the slope differed from 1 for recording intervals >30 s in experiment 1, suggesting that time sampling may have underestimated true values. Of the 2-h periods compared with 24 h of observation, 1800 to 2000 h was most highly correlated (rs = 0.84) for experiment 1, and 1800 to 2000 h and 1400 to 1600 h were the most highly correlated (rs = 0.71 and 0.74, respectively) for experiment 2 with daily values. When using time-sampling methods to characterize brush use, we suggest that the recording interval used and time of day observed should be carefully considered, as time sampling at an interval of 1 to 3 min may measure daily brush use duration, but continuous recording may be required to capture bout characteristics.

Dynamics of infection and pathology induced by the aporocotylid, Cardicola laruei, in Spotted Seatrout, Cynoscion nebulosus (Sciaenidae).

The sciaenid Spotted Seatrout (Cynoscion nebulosus) are infected by blood flukes (Cardicola spp.). A 2 year survey in estuaries of South Carolina, USA, showed that adult flukes and granulomas occurred throughout the year but their prevalence was highest in summer (61% and 84%, respectively), indicating an unusually high level of infection for wild fish. Granulomas remained after adult flukes could no longer be found. PCR-Restriction Fragment Length Polymorphism (RFLP) of a subsample of specimens allowed identification of Cardicola laruei as the only species infecting these seatrout during the period of study. Mean intensity of infection by flukes was higher in female seatrout, suggesting endocrine and/or immune system involvement. The prevalence of granulomas declined sharply in winter, indicating possible mortality of infected seatrout as this species is known to be cold-sensitive. Granulomas were studied using histology, immunohistochemistry, and transmission electron microscopy. Eggs were encapsulated by an inner core of dark epithelioid cells, and an outer core of large epithelioid cells undergoing epithelialization. Fibrosis was observed around granulomas and some granulomas detached from the surrounding damaged myocardium. Numerous inflammatory cells appeared mobilised around granulomas and pathology could be severe, in some cases showing grossly visible blister-like extrusions scattered in the damaged epicardium. At the gross level, some granulomas possessing eggs with live miracidia were observed at the surface of the epicardium. These findings suggest that granulomas carrying both dead and live eggs can clear the fish heart by host-mediated transport through the myocardium, as is known to occur in related human Schistosoma infections.