Disparities in Offering Enrollment in Remote Patient Monitoring for COVID-19

Introduction: Remote patient monitoring (RPM) programs are increasingly common. There is a risk that inequitable use of RPM will perpetuate existing health care disparities. We conducted a study to determine if enrollment in a COVID-19 RPM program was offered differentially across demographic groups. Methods: From March through September 2020, patients with COVID-19 were evaluated within a large academic health system with a standardized care pathway that directed providers to refer the patients for RPM. We conducted a retrospective cohort study to evaluate the effects of social vulnerability and urbanicity of residence on the odds of referral. We estimated vulnerability using the CDC social vulnerability index (SVI) and used logistic regression to determine odds ratios (ORs) for referral based on SVI and urbanicity. Results: Of 16,739 patients who had a qualifying health care encounter, 2,946 (17.6%) were referred for RPM. Patients in census tracts with higher social vulnerability were less likely to be referred than those in tracts with lower vulnerability (OR 0.73, 95% confidence interval 0.63-0.84). Patients living in Micropolitan/Large Rural Cities or Small Towns/Small Rural Towns were more likely to be referred than those in Metropolitan/Urban areas. In the full regression model, including both SVI and urbanicity, urbanicity was the strongest predictor of referral, and patients living in Metropolitan/Urban areas were the most likely to be referred. Conclusions: We found disparities in who is offered access to remote monitoring despite the use of standardized care pathways. Health systems need to evaluate how they implement RPM programs and care pathways to ensure equitable care delivery.

Remote Patient Monitoring for COVID-19: A Retrospective Study on Health Care Utilization

Introduction: Data are limited on the effectiveness of remote patient monitoring (RPM) for acute illnesses, including COVID-19. We conducted a study to determine if enrollment in a COVID-19 RPM program was associated with better outcomes. Methods: From March through September 2020, patients with respiratory symptoms and presumptive COVID-19 were referred to the health system's COVID-19 RPM program. We conducted a retrospective cohort study comparing outcomes for patients enrolled in the RPM (n = 4,435) with those who declined enrollment (n = 2,742). Primary outcomes were emergency room, hospital, and intensive care unit admissions, and death. We used logistic regression to adjust for demographic differences and known risk factors for severe COVID-19. Results: Patients enrolled in the RPM were less likely to have risk factors for severe COVID-19. There was a significant decrease in the odds of death for the group enrolled in the RPM (adjusted odds ratio [OR] = 0.50; 95% confidence interval [CI], 0.30-0.83) and a nonsignificant decrease in the odds of the other primary outcomes. Increased number of interactions with the RPM significantly decreased the odds of hospital admission (OR = 0.92; 95% CI, 0.88-0.95). Conclusions: COVID-19 RPM enrollment was associated with decreased odds of death, and the more patients interacted with the RPM, the less likely they were to require hospital admission. RPM is a promising tool that has the potential to improve patient outcomes for acute illness, but controlled trials are necessary to confirm these findings.

Bayesian estimation of potential outcomes for mediation analysis of racial disparity for infant mortality

Background

There is a need for novel methods to determine preventable causes of racial health disparities. This need has been met with the development of improved methods for mediation modeling. Current mediational analysis methods call for an evaluation of statistical interaction or effect modification between the investigated cause and mediator. For racial disparity, this approach facilitates the estimation of racially specific risks for infant mortality. However, current methods for evaluating multiple interacting mediators are inadequate. The first objective of the study was to compare Bayesian estimation of potential outcomes to other approaches to mediation analysis that included interaction. The second objective was to evaluate three potentially interacting mediators of racial disparity for infant mortality by modeling the large dataset from the National Natality Database using Bayesian estimation of potential outcomes.

Methods

A random sample of observations from the 2003 National Natality Database was used to compare the currently promoted methods for mediation modeling. Racial disparity was modeled as a separate function for each of three potential mediators, (i) maternal smoking, (ii) low birth weight and (iii) teenage maternity. As a second objective, direct Bayesian estimation of potential outcomes modeled infant mortality as function of the interactions among the three mediators and race using the full National Natality Database for the years 2016 to 2018.

Results

The counterfactual model was inaccurate in estimating the proportion of racial disparity that was attributable to either maternal smoking or teenage maternity. The counterfactual approach did not accurately estimate the probabilities defined by counterfactual definitions. The error was a result of modeling the excess relative risk instead of the risk probabilities. Bayesian approaches did estimate the probabilities of the counterfactual definitions. Results showed that 73% of the racial disparity for infant mortality was attributed to infants born with low birth weight.

Conclusions

Bayesian estimation of potential outcomes could evaluate whether proposed public health programs would affect races differently and decisions could include consideration of the causal effect the program may have on racial disparity. The large contribution of low birth weight to racial disparity for infant mortality should be further investigated to identify preventable factors for low birth weight.

Ultrasound versus fine needle aspiration for the initial evaluation of pediatric cervical lymphadenopathy-A systematic review

OBJECTIVE

Cervical lymphadenopathy is a frequent finding in children that poses diagnostic challenges. We sought to compare the utility of fine needle aspiration (FNA) with ultrasound (US) for evaluating pediatric cervical lymphadenopathy based on published literature.

STUDY DESIGN

In October 2019, we performed a comprehensive electronic search of PubMed, OVID (MEDLINE), EMBASE, and Scopus databases. Two authors independently screened and assessed full-text reports of potentially eligible studies. We compared sensitivity, specificity, positive predictive value estimates, and balanced accuracy for determining the underlying etiology of lymphadenopathy.

RESULTS

The initial search returned 7736 possible studies, of which 31 met the criteria for inclusion. A total of 25 studies were included in the final analysis, with a total of 4721 patients, of which 52.8% were male. Of these, 9 (36.0%) examined US, and 16 (64%) examined fine needle aspiration. The pooled balanced accuracy for determining etiology was 87.7% for US and 92.9% for FNA. Reactive lymphadenopathy was identified in 47.9%, 9.2% were malignant, 12.6% were granulomatous, and 6.6% were non-diagnostic.

CONCLUSIONS

In this systematic review, US was identified as an accurate initial diagnostic imaging modality in children. Fine needle aspiration was found to play a significant role in ruling out malignant lesions and potentially avoiding excisional biopsy.

Semi-automated Clinical Content Curation of COVID-19 Chatbot Remote Patient Monitoring Solution

Remote patient monitoring (RPM) programs are being increasingly utilized in the care of patients to manage acute and chronic disease including with acute COVID-19. The goal of this study is to explore the topics and patterns of patients' messages to the care team in an RPM program in patients with presumed COVID-19. We conducted a topic analysis to 6,262 comments from 3,248 patients enrolled in the COVID-19 RMP at M Health Fairview. Evaluation of comments was performed using LDA and CorEx topic modeling. Subject matter experts evaluated topic models, including identification of and defining topics and categories. Topics plotted over time to identify trends in topic weights over the enrollment period. The overall accuracy of comments assignment to topics by LDA and CorEx models were 72.8% and 88.2%. Most identified topics focused on signs and symptoms of COVID-19. Topics related to COVID-19 diagnosis demonstrated a correlation with announcements of availability of viral and antibody testing in national and local media.

A cooperative adsorbent for the switch-like capture of carbon dioxide from crude natural gas

Natural gas constitutes a growing share of global primary energy due to its abundant supply and lower CO₂ emission intensity compared to coal. For many natural gas reserves, CO₂ contamination must be removed at the wellhead to meet pipeline specifications. Here, we demonstrate the potential of the diamine-appended metal–organic framework ee-2–Mg₂(dobpdc) (ee-2 = N,N-diethylethylenediamine; dobpdc⁴⁻ = 4,4′-dioxidobiphenyl-3,3′-dicarboxylate) as a next-generation CO₂ capture material for high-pressure natural gas purification. Owing to a cooperative adsorption mechanism involving formation of ammonium carbamate chains, ee-2–Mg₂(dobpdc) can be readily regenerated with a minimal change in temperature or pressure and maintains its CO₂ capacity in the presence of water. Moreover, breakthrough experiments reveal that water enhances the CO₂ capture performance of ee-2–Mg₂(dobpdc) by eliminating “slip” of CO₂ before full breakthrough. Spectroscopic characterization and multicomponent adsorption isobars suggest that the enhanced performance under humid conditions arises from preferential stabilization of the CO₂-inserted phase in the presence of water. The favorable performance of ee-2–Mg₂(dobpdc) is further demonstrated through comparison with a benchmark material for this separation, zeolite 13X, as well as extended pressure cycling. Overall, these results support continued development of ee-2–Mg₂(dobpdc) as a promising adsorbent for natural gas purification.

Diamine-appended metal–organic frameworks can be optimized as adsorbents for pressure-swing purification of crude natural gas. A cooperative CO₂ binding mechanism enables high CO₂ swing capacities and enhanced performance under humid conditions.

Comparison of small-sample standard-error corrections for generalised estimating equations in stepped wedge cluster randomised trials with a binary outcome: A simulation study

Generalised estimating equations with the sandwich standard-error estimator provide a promising method of analysis for stepped wedge cluster randomised trials. However, they have inflated type-one error when used with a small number of clusters, which is common for stepped wedge cluster randomised trials. We present a large simulation study of binary outcomes comparing bias-corrected standard errors from Fay and Graubard; Mancl and DeRouen; Kauermann and Carroll; Morel, Bokossa, and Neerchal; and Mackinnon and White with an independent and exchangeable working correlation matrix. We constructed 95% confidence intervals using a t-distribution with degrees of freedom including clusters minus parameters (DFC-P), cluster periods minus parameters, and estimators from Fay and Graubard (DFFG), and Pan and Wall. Fay and Graubard and an approximation to Kauermann and Carroll (with simpler matrix inversion) were unbiased in a wide range of scenarios with an independent working correlation matrix and more than 12 clusters. They gave confidence intervals with close to 95% coverage with DFFG with 12 or more clusters, and DFC-P with 18 or more clusters. Both standard errors were conservative with fewer clusters. With an exchangeable working correlation matrix, approximated Kauermann and Carroll and Fay and Graubard had a small degree of under-coverage.

Abstract PO-017: Evaluating the impact of the coronavirus (COVID-19) pandemic on treatment paradigms in head and neck cancer at a tertiary care hospital

Objective: The study aimed to assess the impact of the coronavirus (COVID-19) pandemic on head and neck oncologic care at a tertiary care hospital. The pandemic caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has led to policies designed to limit its spread. Policies including eliminating routine appointments, statewide stay-at-home orders, and restricting surgical cases to emergent surgeries have limited access to care. Therefore, we hypothesized that treatment modifications would be implemented for patients and cancer consultations would decrease compared to historical data.

Methods: Information regarding treatment modifications was collected prospectively during interdepartmental tumor conferences from March 18, 2020 to May 20, 2020. Information regarding patient demographics, tumor characteristics, and incidence of new cancer consultations was collected via chart review. Treatment modifications were categorized as follows: Elimination of Systemic Therapy, Treatment Delay, Change to Non-Surgical Management, or Alteration in Adjuvant Therapy. Rationales for modification were similarly grouped as follows: Operating Room Limitations, Medical Co-Morbidities, COVID-19 positive, Patient concern, or System limitations. We determined the rate of treatment modifications and the frequencies of rationales and modification types. Demographic and tumor characteristics were compared between this population and a retrospectively collected cohort from 2019.

Results: 117 patients were presented during the review period in 2020. There were 69 patients presented across the same time period in 2019. There were no differences in demographic characteristics between the groups. There was no difference between the tumor or nodal stages of the presented cases year over year. During the 2020 time period there were more total case presentations and new cancer cases compared to the 2019 time period. Of the 117 cases presented during the study period, there were 10/117 (8.4%) treatment modifications. The most common reason for modification was limited PPE supply. The most common modification was treatment delay. The second most common modification was change from primary surgical management to nonsurgical management. Treatment modifications occurred most commonly early in the review period and declined subsequently.

Conclusions: Despite the ongoing pandemic and resulting state and institutional restrictions, there was no appreciable reduction in new cancer consultations for head and neck cancer. There were a small number of treatment modifications, particularly early in the course of our state and institutional response to the virus. However, over the 2-month period examined, patient care for these patients remained largely unaffected. While the restriction in elective surgical care was implemented across the state of Maryland, the oncologic triage and emergency surgery prioritization sustained the volume of oncologic practice.

Citation Format: Joshua A. Thompson, Reju Joy, Joshua E. Lubek, Ranee Mehra, Jason K. Molitoris, Rodney J. Taylor, Jeffrey S. Wolf, Matthew E. Witek, Kyle M. Hatten. Evaluating the impact of the coronavirus (COVID-19) pandemic on treatment paradigms in head and neck cancer at a tertiary care hospital [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr PO-017.

Rapid implementation of a COVID-19 remote patient monitoring program

OBJECTIVE

The study sought to evaluate early lessons from a remote patient monitoring engagement and education technology solution for patients with coronavirus disease 2019 (COVID-19) symptoms.

MATERIALS AND METHODS

A COVID-19-specific remote patient monitoring solution (GetWell Loop) was offered to patients with COVID-19 symptoms. The program engaged patients and provided educational materials and the opportunity to share concerns. Alerts were resolved through a virtual care workforce of providers and medical students.

RESULTS

Between March 18 and April 20, 2020, 2255 of 3701 (60.93%) patients with COVID-19 symptoms enrolled, resulting in over 2303 alerts, 4613 messages, 13 hospital admissions, and 91 emergency room visits. A satisfaction survey was given to 300 patient respondents, 74% of whom would be extremely likely to recommend their doctor.

DISCUSSION

This program provided a safe and satisfying experience for patients while minimizing COVID-19 exposure and in-person healthcare utilization.

CONCLUSIONS

Remote patient monitoring appears to be an effective approach for managing COVID-19 symptoms at home.

Rapid implementation of a COVID-19 remote patient monitoring program

OBJECTIVE

The study sought to evaluate early lessons from a remote patient monitoring engagement and education technology solution for patients with coronavirus disease 2019 (COVID-19) symptoms.

MATERIALS AND METHODS

A COVID-19-specific remote patient monitoring solution (GetWell Loop) was offered to patients with COVID-19 symptoms. The program engaged patients and provided educational materials and the opportunity to share concerns. Alerts were resolved through a virtual care workforce of providers and medical students.

RESULTS

Between March 18 and April 20, 2020, 2255 of 3701 (60.93%) patients with COVID-19 symptoms enrolled, resulting in over 2303 alerts, 4613 messages, 13 hospital admissions, and 91 emergency room visits. A satisfaction survey was given to 300 patient respondents, 74% of whom would be extremely likely to recommend their doctor.

DISCUSSION

This program provided a safe and satisfying experience for patients while minimizing COVID-19 exposure and in-person healthcare utilization.

CONCLUSIONS

Remote patient monitoring appears to be an effective approach for managing COVID-19 symptoms at home.

Autoimmune diseases and immune-checkpoint inhibitors for cancer therapy: review of the literature and personalized risk-based prevention strategy

Patients with cancer and with preexisting active autoimmune diseases (ADs) have been excluded from immunotherapy clinical trials because of concerns for high susceptibility to the development of severe adverse events resulting from exacerbation of their preexisting ADs. However, a growing body of evidence indicates that immune-checkpoint inhibitors (ICIs) may be safe and effective in this patient population. However, baseline corticosteroids and other nonselective immunosuppressants appear to negatively impact drug efficacy, whereas retrospective and case report data suggest that use of specific immunosuppressants may not have the same consequences. Therefore, we propose here a two-step strategy. First, to lower the risk of compromising ICI efficacy before their initiation, nonselective immunosuppressants could be replaced by specific selective immunosuppressant drugs following a short rotation phase. Subsequently, combining ICI with the selective immunosuppressant could prevent exacerbation of the AD. For the most common active ADs encountered in the context of cancer, we propose specific algorithms to optimize ICI therapy. These preventive strategies go beyond current practices and recommendations, and should be practiced in ICI-specialized clinics, as these require multidisciplinary teams with extensive knowledge in the field of clinical immunology and oncology. In addition, we challenge the exclusion from ICI therapy for patients with cancer and active ADs and propose the implementation of an international registry to study such novel strategies in a prospective fashion.

Robust analysis of stepped wedge trials using cluster-level summaries within periods

In stepped‐wedge trials (SWTs), the intervention is rolled out in a random order over more than 1 time‐period. SWTs are often analysed using mixed‐effects models that require strong assumptions and may be inappropriate when the number of clusters is small.

We propose a non‐parametric within‐period method to analyse SWTs. This method estimates the intervention effect by comparing intervention and control conditions in a given period using cluster‐level data corresponding to exposure. The within‐period intervention effects are combined with an inverse‐variance‐weighted average, and permutation tests are used. We present an example and, using simulated data, compared the method to (1) a parametric cluster‐level within‐period method, (2) the most commonly used mixed‐effects model, and (3) a more flexible mixed‐effects model. We simulated scenarios where period effects were common to all clusters, and when they varied according to a distribution informed by routinely collected health data.

The non‐parametric within‐period method provided unbiased intervention effect estimates with correct confidence‐interval coverage for all scenarios. The parametric within‐period method produced confidence intervals with low coverage for most scenarios. The mixed‐effects models' confidence intervals had low coverage when period effects varied between clusters but had greater power than the non‐parametric within‐period method when period effects were common to all clusters.

The non‐parametric within‐period method is a robust method for analysing SWT. The method could be used by trial statisticians who want to emphasise that the SWT is a randomised trial, in the common position of being uncertain about whether data will meet the assumptions necessary for mixed‐effect models.

Hydroxyapatite-doped alginate beads as scaffolds for the osteoblastic differentiation of mesenchymal stem cells

This work investigates the role of an osteoblastic matrix component, hydroxyapatite (HA), in modular alginate scaffolds to support osteoblastic differentiation of human mesenchymal stem cells for the purpose of tissue engineered bone constructs. This system is first evaluated in a tubular perfusion bioreactor, which has been shown to improve osteoblastic differentiation over static culture conditions. HMSCs in alginate scaffolds that contain HA show increased osteoblastic gene expression compared to cells in pure alginate scaffolds, as well as significantly more matrix production and mineralization. The differentiated hMSCs and cell-laid matrix are ultimately evaluated in an in vivo site specific model. Implantation of these scaffolds with preformed matrix into the rat femoral condyle defects results in abundant bone growth and significant incorporation of the scaffold into the surrounding tissue. The developed mineralized matrix, induced in part by the HA component in the scaffold, could lead to increased tissue development in critically sized defects, and should be included in future implant strategies. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2325-2333, 2016.

Evaluation of the in vitro cytotoxicity of cross-linked biomaterials

This study evaluated the in vitro cytotoxicity of poly(propylene fumarate) (PPF). PPF is an aliphatic biodegradable polymer that has been well characterized for use in bone tissue engineering scaffolds. Four different cell types, human mesenchymal stem cells (hMSC), fibroblasts (L929), preosteoblasts (MC3T3), and canine mesenchymal stem cells (cMSC), were used to evaluate the cytotoxicity of PPF. These cell types represent the tissues that PPF would interact with in vivo as a bone tissue scaffold. The sol fraction of the PPF films was measured and then utilized to estimate cross-linking density. Cytotoxicity was evaluated using XTT assay and fluorescence imaging. Results showed that PPF supported similar cell metabolic activities of hMSC, L929, MC3T3, and cMSC compared to the noncytotoxic control, high-density polyethylene (HDPE) and were statistically different than those cultured with the cytotoxic control, a polyurethane film containing 0.1% zinc diethyldithiocarbamate (ZCF). Results showed differing cellular responses to ZCF, the cytotoxic control. The L929 cells had the lowest cell metabolic activity levels after exposure to ZCF compared to the cell metabolic activity levels of the MC3T3, hMSC, or cMSC cells. Qualitative verification of the results using fluorescence imaging demonstrated no change in cell morphology, vacuolization, or detachment when cultured with PPF compared to HDPE or blank media cultures. Overall, the cytotoxicity response of the cells to PPF was demonstrated to be similar to the cytotoxic response of cells to known noncytotoxic materials (HDPE).

The effects of multidisciplinary rehabilitation in patients with early-to-middle-stage Huntington's disease: a pilot study

BACKGROUND AND PURPOSE

Despite advances in the understanding of Huntington's disease (HD), treatment remains symptomatic. Multidisciplinary rehabilitation, however, appears to impact disease progression. Here we show the feasibility, safety and efficacy of a 9-month multidisciplinary rehabilitation programme in a small cohort of patients with early-to-middle-stage HD.

METHODS

Twenty patients with HD were assigned to two groups, equally matched for cognitive and motor scores. One group received the intervention, whilst the other served as control. The Unified-Huntington's-Disease-Rating-Scale-Total-Motor-Score was the primary outcome measure. Neurocognitive/psychological tests, body composition, postural stability, strength and quality of life assessments were secondary outcome measures.

RESULTS

The intervention reduced motor and postural stability deterioration, with minor improvements in depression, cognition and quality of life. Significant gains were observed for fat-free mass and strength.

CONCLUSION

This pilot study suggests that a prolonged multidisciplinary rehabilitation programme in early-to-middle-stage HD is feasible, well-tolerated and associated with therapeutic benefit. Further explorative, larger studies are warranted.

Everolimus in metastatic renal cell carcinoma: Subgroup analysis of patients with 1 or 2 previous vascular endothelial growth factor receptor-tyrosine kinase inhibitor therapies enrolled in the phase III RECORD-1 study

INTRODUCTION

In the phase III RECORD-1 trial (ClinicalTrials.gov: NCT00410124), patients with metastatic renal cell carcinoma (mRCC) who progressed on previous vascular endothelial growth factor receptor-tyrosine kinase inhibitor (VEGFr-TKI) therapy were randomised 2:1 to everolimus 10mg once daily (n=277) or placebo (n=139). Median progression-free survival (PFS) was 4.9months with everolimus and 1.9months with placebo (hazard ratio [HR], 0.33; P<.001). This preplanned, prospective sub-analysis evaluated PFS benefit of everolimus versus placebo in patients who had previously received 1 or 2 VEGFr-TKIs.

PATIENTS AND METHODS

Median PFS was estimated using the Kaplan-Meier method, and Cox proportional hazards model was used to analyse differences in PFS.

RESULTS

All patients (100%) received ⩾1 previous VEGFr-TKI; 26% of patients received 2 previous VEGFr-TKIs. Among patients who received 1 previous VEGFr-TKI, median PFS was 5.4months with everolimus and 1.9months with placebo (HR, 0.32; 95%confidence interval [CI], 0.24-0.43; P<.001). Among patients who received 2 previous VEGFr-TKIs, median PFS was 4.0months with everolimus and 1.8months with placebo (HR, 0.32; 95%CI, 0.19-0.54; P<.001). The everolimus safety profile was similar for both groups.

CONCLUSIONS

Everolimus was associated with prolonged PFS relative to placebo in patients who received 1 or 2 previous VEGFr-TKIs. Patients who received only 1 previous VEGFr-TKI had apparently longer PFS with everolimus in reference to those who received 2 previous VEGFr-TKIs. These results support the use of everolimus as the standard of care in patients who fail initial VEGFr-TKI therapy.

Point-of-care oral-based diagnostics

Many of the target molecules that reside in blood are also present in oral fluids, albeit at lower concentrations. Oral fluids are, however, relatively easy and safe to collect without the need for specialized equipment and training. Thus, oral fluids provide convenient samples for medical diagnostics. Recent advances in lab-on-a-chip technologies have made minute, fully integrated diagnostic systems practical for an assortment of point-of-care tests. Such systems can perform either immunoassays or molecular diagnostics outside centralized laboratories within time periods ranging from minutes to an hour. The article briefly reviews recent advances in devices for point-of-care testing with a focus on work that has been carried out by the authors as part of a NIH program.

Porous EH and EH-PEG scaffolds as gene delivery vehicles to skeletal muscle

PURPOSE

Synthetic biomaterials are widely used in an attempt to control the cellular behavior of regenerative tissues. This can be done by altering the chemical and physical properties of the polymeric scaffold to guide tissue repair. This paper addresses the use of a polymeric scaffold (EH network) made from the cyclic acetal monomer, 5-ethyl-5-(hydroxymethyl)-β,β-dimethyl-1,3-dioxane-2-ethanol diacrylate (EHD), as a release device for a therapeutic plasmid encoding for an insulin-like growth factor-1 green fluorescent protein fusion protein (IGF-1 GFP).

METHODS

Scaffolds were designed to have different porous architectures, and the impact of these architectures on plasmid release was determined. We hypothesized that IGF-1 could be delivered more effectively using a porous scaffold to allow for the release of IGF-1.

RESULTS

We showed that by altering the number of pores exposed to the surface of the network, faster plasmid loading and release were achieved. In addition, the IGF-1 GFP plasmids were found to be effective in producing IGF-1 and GFP within human skeletal muscle myoblast cell cultures.

CONCLUSIONS

This work aims to show the utility of EH biomaterials for plasmid delivery for potentially localized skeletal muscle regeneration.

Patterns of nurse-physician communication and agreement on the plan of care

BACKGROUND

Interdisciplinary communication is critically important to provide safe and effective care, yet it has been inadequately studied for hospitalised medical patients. Our objective was to characterise nurse-physician communication and their agreement on patients' plan of care.

METHODS

During a one-month period, randomly selected hospitalised patients, their nurses and their physicians were interviewed. Nurses and physicians were asked to identify one another, whether communication had occurred, and about six aspects of the plan of care. Two internists rated nurse-physician agreement on aspects of the plan of care as none, partial or complete agreement. Measures included the percentage of nurses and physicians able to identify one another and reporting communication and the percentage of nurse-physician pairs in agreement on aspects of the plan of care.

RESULTS

310 (91%) and 301 (88%) of 342 eligible nurses and physicians completed interviews. Nurses correctly identified patients' physicians 71% of the time and reported communicating with them 50% of the time. Physicians correctly identified the patients' nurses 36% of the time and reported communicating with them 62% of the time. Physicians and nurses showed no agreement on aspects of the plan of care ranging from 11% for planned procedures to 42% for medication changes.

CONCLUSIONS

Nurses and physicians did not reliably communicate with one another and were often not in agreement on the plan of care for hospitalised medical patients.

The relation of neuropsychological measures to levels of cognitive functioning in elderly individuals: a discriminant analysis approach

This study addresses the question of which tests in a comprehensive neuropsychologicaI test battery best discriminate normal, mildly, and moderate to severely cognitiveIy impaired older participants. Sixty-six geriatric participants were administered a battery of neuropsychological tests as part of an outpatient geriatric clinic evaluation. A discriminant analysis procedure using a consensus rating of global cognitive impairment as the grouping variable was employed to analyze the data. From 15 neuropsychological test measures, five representing the domains of learning and memory, visuospatial and executive functioning were identified as the best predictors of level of cognitive impairment. Findings demonstrate the utility of discriminant function analysis (DFA) procedures for developing reduced-length cognitive batteries that accurately classify participants in terms of levels of cognitive impairment and identify mild dysfunction in participants at risk of cognitive impairment. Further cross-validation studies are needed to confirm the utility of these more circumscribed batteries.

The Impact of Cooling Ponds in North Central Texas on Dairy Farm Performance

The objective of this study was to determine whether measurable differences existed between farms with and without cooling ponds. Data from Dairy Herd Improvement records for 1999 through 2002 were obtained on 42 herds located in North Central Texas. Nineteen herds had installed cooling ponds, whereas 23 herds had not. Monthly somatic cell counts for each herd were obtained from the Federal Milk Market Administrator. Data were analyzed using the PROC MIXED regression model of SAS. Within and across herd groups, milk production from June to October was significantly lower compared with milk production for the rest of the year. Although there was numerically higher average milk production per cow per day throughout the year for herds that used cooling ponds, differences between herd groups that used or did not use cooling ponds were significant only for August production. Herds without a cooling pond had 4.8 kg/d per cow lower production in August than in the cool-season months of November to May (26.4 +/- 0.6 vs. 31.2 +/- 0.5 kg/d), whereas the difference in August production was only 2.9 kg/d per cow in herds that used cooling ponds (29.0 +/- 0.7 vs. 31.9 +/- 0.6 kg/d). Differences caused by seasonal use of a cooling pond in culling, days to first service, days open, percentage of estruses observed, and somatic cell counts were not significant. Bulk tank milk samples cultured for 10 different bacteria showed no difference between cooling pond and noncooling pond herds in 2002. Also, there was no difference in incidence of violations from the Texas Department of Health for herds that used or did not use cooling ponds. However, herds with cooling ponds did have a lower percentage of successful breedings, fewer days dry, and a higher percentage of cows in milk compared with dairy herds that used other forms of cooling. Such differences may or may not be attributed to seasonal use of a cooling pond. Therefore, cooling ponds may provide relief from heat stress without adversely affecting most important measures of herd performance.

Spatial distribution of antibodies to Salmonella enterica serovar Typhimurium O antigens in bulk milk from Texas dairy herds

Environmental factors that enhance either the survivability or dispersion of Salmonella enterica serovar Typhimurium (S. Typhimurium) could result in a spatial pattern of disease risk. The objectives of this study were to: (1) describe herd status based on antibody response to Salmonella Typhimurium as estimated from bulk tank milk samples and (2) to describe the resulting geographical patterns found among Texas dairy herds. Eight hundred and fifty-two bulk milk samples were collected from georeferenced dairy farms and assayed by an indirect enzyme-linked immunosorbent assay (ELISA) using S. Typhimurium lipopolysaccharide (LPS). ELISA signal-to-noise ratios for each bulk tank milk sample were calculated and used for geostatistical analyses. Best-fit parameters for the exponential theoretical variogram included a range of 438.8 km, partial sill of 0.060 and nugget of 0.106. The partial sill is the classical geostatistical term for the variance that can be explained by the herd's location and the nugget is the spatially random component of the variance. We have identified a spatial process in bulk milk tank titers for S. Typhimurium in Texas dairy herds and present a map of the expected smoothed surface. Areas with higher expected titers should be targeted in further studies on controlling Salmonella infection with environmental modifications.

Infant botulism in the age of botulism immune globulin

Infant botulism causes acute bulbar dysfunction, weakness, and respiratory failure in infants living in endemic regions of the United States. Until Food and Drug Administration approval of botulism immune globulin (BIG) in October 2003, management of infant botulism had changed little since the 1970s. Currently, IV therapy with BIG is advised to shorten the duration and diminish the potential complications of the disorder. This review describes two decades of experience with infant botulism and provides a contemporary perspective on the role and benefit of BIG.

Relationship of seminal plasma level and extender type to sperm motility and DNA integrity

The relationship between seminal plasma level (0, 10, or 20%) and extender type [Kenney type (EZ-Mixin-CST) or Kenney-modified Tyrodes-KMT] to the susceptibility of sperm DNA to denaturation and sperm motility measures were investigated in cooled (5 degrees C) stallion sperm. Three ejaculates from each of three fertile stallions were collected in an artificial vagina and processed as follows: diluted one part uncentrifuged semen with four parts of extender to a final concentration of 20% seminal plasma in either CST or KMT (20% CST; 20% KMT); diluted to a final concentration of 25 million sperm/mL in either CST or KMT (10% CST; 10% KMT); centrifuged to remove virtually all seminal plasma and resuspended in either CST or KMT (0% CST-Cent; 0% KMT-Cent); centrifuged semen to remove virtually all seminal plasma and resuspended with previously filtered seminal plasma from the same stallion in either CST or KMT to a final concentration of 20% seminal plasma (20% CST-Cent; 20% KMT-Cent). Sperm motion characteristics were determined by CASA and DNA integrity (%COMP, percent of cells outside the main population) evaluated by the Sperm Chromatin Structure Assay prior to cooling, and after 24 and 48 h cooled-storage at 5 degrees C. After 48 h of storage at 5 degrees C, extenders with 0% seminal plasma (0% CST-Cent, 0% KMT-Cent) maintained highest quality DNA (P < 0.05), but 0% KMT-Cent maintained higher velocity measures (P < 0.05) than 0% CST-Cent. Total sperm motility was highest (P < 0.05) in 0% CST-Cent, 0% KMT-Cent, 10% CST, 20% CST-Cent, and 20% CST compared to the other treatment groups. Progressive sperm motility was highest (P < 0.05) after 48 h of storage in the treatment with 10% seminal plasma in Kenney extender (10% CST), despite a reduction in DNA integrity. Regardless of extender type, addition of 20% seminal plasma following centrifugation resulted in almost a two-fold increase in %COMP(alpha t), even though one of the treatments (20% CST-Cent) maintained total and progressive motility similar to treatments with no seminal plasma, suggesting that sperm motility and DNA integrity may respond independently to environmental conditions. Overall, better quality sperm features (motility and DNA) were maintained in sperm from which seminal plasma was removed followed by resuspension in either Kenney extender or modified Kenney Tyrodes-type extender.

Site-specific delivery of acidic fibroblast growth factor stimulates angiogenic and osteogenic responsesin vivo

A major clinical problem in orthopedics is the healing of nonunion fractures. Limitations of this bone repair process include insufficient angiogenesis and mineralization. Integrating appropriate biomaterials with site-specific neovascularization and osteogenesis at the wound site has been the focus of several clinically relevant therapeutic strategies. As an extracellular protein, acidic fibroblast growth factor (FGF-1) induces, coordinates, and sustains site-specific molecular responses associated with angiogenesis and osteogenesis. To establish the ability of this growth factor to coordinate bone regenerative process in vivo, site-specific delivery of FGF-1, entrapped in a fibrin/hydroxyapatite composite, was evaluated. Kinetic analysis in vivo revealed the biocomposite was capable of delivering biologically active FGF-1. Release kinetics revealed an initial delivery of 87.5 ng/h of active FGF-1 in the first 20 h, followed by a reduced delivery of 28 ng/h during the next 20 h. In situ immunohistological analyses demonstrated that FGF-1-containing implants induced increased angiogenesis and infiltration of cells expressing osteogenic related markers (i.e., osteopontin, osteocalcin). Collectively, these efforts support that site-specific delivery of active FGF-1 in a fibrin/hydroxyapatite composite is competent to induce not only angiogenesis but also osteogenic cellular responses.

High statistics measurement of the K+-->pi0e+nu (K+e3) branching ratio

E865 at the Brookhaven National Laboratory AGS collected about 70 000 K(+)(e3) events to measure the K(+)(e3) branching ratio relative to the observed K+-->pi(+)pi(0), K+-->pi(0)micro(+)nu, and K+-->pi(+)pi(0)pi(0) decays. The pi(0) in all the decays was detected using the e(+)e(-) pair from pi(0)-->e(+)e(-)gamma decay and no photons were required. Using the 2002 Particle Data Group branching ratios for the normalization decays, we obtain BR(K(+)(e3(gamma)))=(5.13+/-0.02(stat)+/-0.09(syst)+/-0.04(norm))%, where K(+)(e3(gamma)) includes the effect of virtual and real photons. This result is approximately 2.3sigma higher than the current Particle Data Group value. Implications for the V(us) element of the CKM matrix, and the matrix's unitarity are discussed.

Relationship between stallion sperm motility and viability as detected by two fluorescence staining techniques using flow cytometry

Relationships between sperm motility parameters and viability were evaluated using two fluorescent staining techniques in fresh extended semen (fresh and after 24 h storage at 5 degrees C) that had various concentrations of dead sperm added to simulate different levels of viable and nonviable sperm. Both protocols incorporated SYBR-14 and propidium iodide (PI) while the second protocol added the mitochondrial probe JC-1. The relationship between total sperm motility and percent viable sperm was high between staining protocols (r = 0.98). Time (0 h versus 24 h, P<0.0001) and treatment (0, 10, 25, 50, and 75% nonviable sperm, P<0.0001) affected percent total sperm motility and percent viable sperm for both staining protocols. Actual percent viable sperm for each time and treatment did not differ from expected values.

Adoptive T cell therapy using antigen-specific CD8+ T cell clones for the treatment of patients with metastatic melanoma: in vivo persistence, migration, and antitumor effect of transferred T cells

Adoptive T cell therapy, involving the ex vivo selection and expansion of antigen-specific T cell clones, provides a means of augmenting antigen-specific immunity without the in vivo constraints that can accompany vaccine-based strategies. A phase I study was performed to evaluate the safety, in vivo persistence, and efficacy of adoptively transferred CD8+ T cell clones targeting the tumor-associated antigens, MART1MelanA and gp100 for the treatment of patients with metastatic melanoma. Four infusions of autologous T cell clones were administered, the first without IL-2 and subsequent infusions with low-dose IL-2 (at 0.25, 0.50, and 1.0 x 10(6) unitsm(2) twice daily for the second, third, and fourth infusions, respectively). Forty-three infusions of MART1MelanA-specific or gp100-specific CD8+ T cell clones were administered to 10 patients. No serious toxicity was observed. We demonstrate that the adoptively transferred T cell clones persist in vivo in response to low-dose IL-2, preferentially localize to tumor sites and mediate an antigen-specific immune response characterized by the elimination of antigen-positive tumor cells, regression of individual metastases, and minor, mixed or stable responses in 8 of 10 patients with refractory, metastatic disease for up to 21 mo.

National audit of the outcome of primary surgery for rhegmatogenous retinal detachment. II. Clinical outcomes

PURPOSE

This national study was designed to audit anatomical outcome and complications relating to primary surgery for rhegmatogenous retinal detachments. This paper presents success and complication rates, and examines variations in outcome.

METHODS

Sampling and recruitment details of this nationwide cross-sectional survey of 768 patients of 167 consultant ophthalmologists having their first operation for rhegmatogenous retinal detachment have been described. The main clinical outcomes detailed here are anatomical reattachment at 3 months after surgery and complications related to surgery. Consultants with a declared special interest in retinal surgery and able to perform pars plana vitrectomy were designated specialists for the analyses.

RESULTS

Overall reattachment rate with a single procedure was 77% (95% CI 73.9-80.2). There were significant differences in reattachment rates between specialists and non-specialists. Without allowing for case-mix, specialists had a reattachment rate of 82% (95% CI 77.9-85.7) with a single procedure and non-specialists 71% (95% CI 65.9-76.0). Allowing for case-mix, there was a significant difference between specialists and non-specialists for grade 2 detachments of 87% and 70% respectively (P < 0.0001). Analysing detachments by break type, the largest difference between specialists and non-specialists was observed for retinal detachments secondary to horseshoe tears, 80% and 68% respectively (P < 0.003). Specialists met the standards set for primary reattachment rates, while non-specialists did not. Over a third of patients had at least one complication reported at some point during the audit period.

CONCLUSIONS

Significant differences were seen in reattachment rates between specialists and non-specialists, overall and for specific subgroups of patients. This study provides relevant, robust and valid standards to enable all surgeons to audit their own surgical outcomes for primary retinal detachment repair in rhegmatogenous retinal detachments, identify common categories of failure and aim to improve results.

National audit of the outcome of primary surgery for rhegmatogenous retinal detachment. I. Sample and methods

PURPOSE

This national study was designed to audit anatomical outcome and complications relating to primary surgery for rhegmatogenous retinal detachments. This paper presents survey methods, characteristics of participating consultants and the demographic and clinical characteristics of the patient sample.

METHODS

Two surveys were undertaken. The first identified consultants who at the time performed retinal detachment surgery in the National Health Service. These surgeons formed the sampling frame for a nationwide cross-sectional clinical study that audited the outcomes of primary surgery for rhegmatogenous retinal detachments. Consultants selected patients according to the study eligibility criteria and data were collected by self-administered postal questionnaires. A validation exercise was carried out to examine selection bias and reporting accuracy.

RESULTS

Only 256/671 (38%) of UK consultants, who responded to the first survey, indicated that they performed retinal detachment surgery on NHS patients. Annual activity varied between 0 and 400 primary procedures for rhegmatogenous retinal detachments. Seven hundred and sixty-eight eligible patients from 167 consultants were recruited for the clinical study. Twenty per cent of patients had a single retinal break with less than one quadrant of associated detachment and 45% had single or multiple breaks within the same quadrant and/or less than two quadrants of associated retinal detachment. Over 50% patients had single or multiple horseshoe tears. Validation studies suggested that there was no significant bias from the selection of patients or inaccuracy in reporting outcomes.

CONCLUSIONS

This large unselected group of primary rhegmatogenous retinal detachments provides a representative sample for considering variations in re-attachment rates.

Experimental study of the radiative decays K+-->mu(+)nue(+)e(-) and K+-->e(+)nue(+)e(-)

Experiment 865 at the Brookhaven Alternating Gradient Synchrotron obtained 410 K+-->e(+)nue(+)e(-) and 2679 K+-->mu(+)nue(+)e(-) events including 10% and 19% background. The branching ratios were measured to be [2.48+/-0.14(stat)+/-0.14(syst)]x10(-8) (m(ee)>150 MeV) and (7.06+/-0.16+/-0.26)x10(-8) (m(ee)>145 MeV), respectively. Results for the decay form factors are presented.

Effect of storage time and temperature on stallion sperm DNA and fertility

We used the sperm chromatin structure assay (SCSA) to study the change in stallion sperm DNA susceptibility to denaturation after exposure of extended semen to three different storage temperatures (5, 20, or 37 degrees C) at 7, 20, 31, and 46 h. In addition, we compared the rates of sperm DNA denaturation in fertile and subfertile stallions. Among fertile stallions, spermatozoa stored at 20 and 37 degrees C showed a significant (P < 0.05) rise in the SCSA measures (Mean(alpha1), S.D.(alpha(t)), and percent cells outside the main population-COMP(alpha(t))) overtime, with the degree of rise being more dramatic at 37 degrees C. Over all stallions, samples stored at 5 degrees C showed no significant (P > 0.05) changes in the SCSA values measured over time, indicating maintenance of chromatin quality for up to 46 h. The COMP(alpha(t)) from stallions classified as subfertile showed an increased susceptibility to denaturation or decline in chromatin quality between 20 and 31 h when stored at 5 degrees C; however, spermatozoa from fertile stallions did not change during the time intervals analyzed. These data suggest that sperm DNA from some subfertile stallions may decline at a greater rate than spermatozoa from fertile stallions when exposed to similar storage conditions.

Oxygen radical inhibition of nitric oxide-dependent vascular function in sickle cell disease

Plasma xanthine oxidase (XO) activity was defined as a source of enhanced vascular superoxide (O(2)( *-)) and hydrogen peroxide (H(2)O(2)) production in both sickle cell disease (SCD) patients and knockout-transgenic SCD mice. There was a significant increase in the plasma XO activity of SCD patients that was similarly reflected in the SCD mouse model. Western blot and enzymatic analysis of liver tissue from SCD mice revealed decreased XO content. Hematoxylin and eosin staining of liver tissue of knockout-transgenic SCD mice indicated extensive hepatocellular injury that was accompanied by increased plasma content of the liver enzyme alanine aminotransferase. Immunocytochemical and enzymatic analysis of XO in thoracic aorta and liver tissue of SCD mice showed increased vessel wall and decreased liver XO, with XO concentrated on and in vascular luminal cells. Steady-state rates of vascular O(2)( *-) production, as indicated by coelenterazine chemiluminescence, were significantly increased, and nitric oxide (( *)NO)-dependent vasorelaxation of aortic ring segments was severely impaired in SCD mice, implying oxidative inactivation of ( *)NO. Pretreatment of aortic vessels with the superoxide dismutase mimetic manganese 5,10,15,20-tetrakis(N-ethylpyridinium-2-yl)porphyrin markedly decreased O(2)( small middle dot-) levels and significantly restored acetylcholine-dependent relaxation, whereas catalase had no effect. These data reveal that episodes of intrahepatic hypoxia-reoxygenation associated with SCD can induce the release of XO into the circulation from the liver. This circulating XO can then bind avidly to vessel luminal cells and impair vascular function by creating an oxidative milieu and catalytically consuming (*)NO via O(2)( small middle dot-)-dependent mechanisms.

Mitochondrial tyrosine nitration precedes chronic allograft nephropathy

Endogenous tyrosine nitration and inactivation of manganese superoxide dismutase (MnSOD) has previously been reported to occur during end-stage human renal allograft rejection. In order to determine whether nitration and inactivation of this critical mitochondrial protein might play a contributory role in the onset of transplant rejection, we employed a rodent model of Chronic Allograft Nephropathy (or CAN). Using this model we followed kidney function from 2-52 weeks post-transplant and correlated graft function with levels of nitration in the renal allograft. Tyrosine nitration of both glomerular and tubular structures occurred at 2 weeks post-transplant. At later times (16 weeks) post-transplant, tyrosine nitration appeared to be confined to tubular structures; however glomerular nitration returned at 52 weeks post-transplant. Interestingly, nitration and inactivation of MnSOD occurs prior to the onset of renal dysfunction in this rat model of chronic allograft nephropathy (2 weeks versus 16 weeks post-transplant). Furthermore, we have identified an additional mitochondrial protein, cytochrome c, as being endogenously nitrated during chronic rejection. The kinetics of cytochrome c nitration lagged behind MnSOD nitration and inactivation (4 weeks compared to 2 weeks); suggesting that loss of MnSOD activity likely contributes to elevation of the nitrating species and further nitration of other targets.

Estrogen-induced vasoprotection is independent of inducible nitric oxide synthase expression: evidence from the mouse carotid artery ligation model

BACKGROUND

Estrogen is vasoprotective in animal models of vascular injury, yet the mechanisms involved are incompletely understood. The role of inducible nitric oxide synthase (iNOS) in vascular repair is controversial, but many lines of evidence indicate that it plays a role in neointima formation after arterial injury and that 17beta-estradiol (E(2)) modulates iNOS expression. This study tested the hypothesis that E(2) reduces neointima formation after vascular injury via a mechanism that is dependent on modulation of iNOS expression.

METHODS AND RESULTS

Male and female wild-type (iNOS(+/+)) mice and mice with homozygous deletion of the iNOS gene (iNOS(-/-)) were studied intact (INT) or after ovariectomy (OVX) and implantation of E(2) or vehicle (V) pellets. Mice were randomized to 8 groups based on sex, iNOS status, OVX, and treatment with E(2) or V. Twenty-eight days after carotid artery ligation, mice were euthanized, and occluded vessels were evaluated for neointima formation by morphometric analysis. There was a marked sexual dimorphism in neointima formation in both the iNOS(+/+) mice and the iNOS(-/-) mice. iNOS(+/+) INT females had a >90% reduction in neointima formation compared with iNOS(+/+) males, and iNOS(-/-) INT females had a 65% reduction in neointima formation compared with iNOS(-/-) males. The sexually dimorphic response was attenuated by OVX and restored by E(2) replacement in both iNOS(+/+) and iNOS(-/-) mice.

CONCLUSIONS

These results demonstrate that the vasoprotective effects of E(2) after ligation vascular injury are, at least in part, independent of iNOS expression.

New measurement of K(+)(e4) decay and the s-pave pi pi-scattering length a(0)(0)

A sample of 4 x 10(5) events from the decay K(+)-->pi(+)pi(-)e(+)nu(e) (K(e4)) has been collected in experiment E865 at the Brookhaven Alternating Gradient Synchrotron. The analysis of these data yields new measurements of the K(e4) branching ratio [(4.11+/-0.01+/-0.11) x 10(-5)], the s-wave pi pi scattering length [a(0)(0) = 0.216+/-0.013(stat)+/-0.004(syst)+/-0.005(theor)], and the form factors F, G, and H of the hadronic current and their dependence on the invariant pi pi mass.

Feeding practices associated with colic in horses

OBJECTIVE

To determine whether specific feeding practices were associated with development of colic in horses.

DESIGN

Prospective matched case-control study.

ANIMALS

364 horses examined by veterinarians in private practice in Texas because of colic (cases; n = 182) or any other reason (controls; 182).

PROCEDURE

Participating veterinarians were sent forms at the beginning of the study to collect information on signalment, feeding management practices, farm management practices, and preventive medical treatments. Case and control horses were compared by use of conditional logistic regression to identify factors associated with colic.

RESULTS

Risk factors for colic were a recent change in batch of hay, decreased exposure to pasture, a recent change in type of grain or concentrate fed, feeding > 2.7 kg (6 lb) of oats/d, feeding hay from round bales, and Thoroughbred breed. Recent anthelmintic administration decreased the risk of colic.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that certain changes in diet (eg, change in batch of hay, change in type of grain or concentrate, feeding hay from round bales) and management (eg, decreased availability of pasture) increase the risk of colic in horses.

Ranch-management factors associated with antibody seropositivity for Neospora caninum in consignments of beef calves in Texas, USA

A study was conducted with a 1998 retained-ownership population of Texas (USA) beef calves to determine the ranch-management practices associated with calf seroprevalence to Neospora caninum. Management practices of 76 Texas ranches that consigned 760 calves to a retained-ownership feedlot program were reviewed from a mailed questionnaire. Ninety-nine of 760 (13%; 95% CI, 9.4%, 17.7%) calves were positive to N. caninum and 59% of the ranches consigned at least one positive calf. In the logistic multiple-regression model which controlled for overdispersion, increased odds of calf-level seropositivity was associated with seasonal calving patterns, with stocking>1cow/calfunit/2.2ha, using a round-bale feeder, allowing wildlife access to the weaning supplement, and self-reared replacement heifers. However, decreased odds of seropositivity was associated with using a cattle-working dog and with using a self-contained cattle feeder. There was substantial overdispersion due to ranch.

Association of serologic status for Neospora caninum and postweaning feed efficiency in beef steers

OBJECTIVE

To determine the effects of serologic status for Neospora caninum on short-term weight gain, feed intake, and feed efficiency (feed intake/gain).

DESIGN

Longitudinal observational study.

ANIMALS

34 weaned mixed-breed beef steers.

PROCEDURE

Serologic status for N. caninum was determined for each steer on days 0 (weaning), 88, 116, 144, 172, and 200, using an agglutination test. Individual steer body weight was measured on days 0, 88, 116, 144, 172, 200, and 242 (slaughter). Daily feed intake was monitored from days 116 through 242. Serologic status was matched to animal performance for the period immediately following serum sample collection. A mixed mode, using repeated-measures with an unstructured covariance matrix, was used in the analysis. Breed, age, and pen effects were controlled for in the analysis.

RESULTS

A reduction in average daily gain for the period following a positive serologic result was detected for the entire trial (6 measurements/steer). This may have been attributed to a significant impairment in feed efficiency rather than to an impairment in feed intake. Changes in serologic status in individual steers over time were common; additionally, the effects of serologic status on steer performance were also transitory.

CONCLUSIONS AND CLINICAL RELEVANCE

Significant reductions in short-term weight gain and feed efficiency were associated with the presence of antibodies against N. caninum in postweaning beef steers.

Acidic fibroblast growth factor signaling inhibits peroxynitrite-induced death of osteoblasts and osteoblast precursors

After trauma injury to the musculoskeletal system, conditions such as ischemia and inflammation involve excess production of superoxide (O2*), nitric oxide (*NO), and their reaction product, peroxynitrite (ONOO-). Exposure of murine osteoblasts and rat-derived primary osteoblast precursors to ONOO- resulted in a dose- and time-dependent delayed cell death that was more characteristic of apoptosis than necrosis. Exposure of both cell populations to ONOO- immediately enhanced phosphorylation and nitration of tyrosine residues within several polypeptides. Treatment of osteoblasts and osteoblast precursors with exogenous acidic fibroblast growth factor (FGF-1) enhanced cellular growth, increased endogenous levels of tyrosine phosphorylation, and significantly induced expression of both osteopontin and osteocalcin messenger RNA (mRNA) as well as osteopontin protein. Pretreatment of both cell populations with exogenous FGF-1 prevented ONOO(-)-mediated death. Cell signaling induced by FGF-1 pretreatment had no major effect of total levels of tyrosine nitration after ONOO- treatment. Collectively, these in vitro efforts show that FGF-1 signaling renders osteoblasts and osteoblast precursors resistant to the cytotoxic effects of ONOO-. Consequently, results presented here predict the therapeutic use of this growth factor for promoting the progression of bone repair mechanisms after fracture trauma.