Abstract P470: Total Plaque Area and Association With Stroke Risk Factors in a Native American Population

Objective: Total plaque area (TPA) has been associated with stroke risk factors; however, it has not been well studied in a Native American population. The objective of this study is to examine the relationship of TPA with stroke risk factors (RF).

Methods: Participants enrolled in the “Stroke Prevention in the Wisconsin Native American Population” (n=119) underwent a health history risk assessment, cognitive testing, carotid ultrasound to measure TPA, and a meeting with a health wellness coach. TPA for each participant was measured using the LifeQ Medical Plaque Analysis Software (Nicosia, Cyprus). Statistical analyses were performed using SPSS (SPSS, IBM Corporation, Armonk, NY, USA) and SAS (SAS Institute Inc., Cary, NC, USA). Descriptive statistics for continuous variables are reported as the median and interquartile range (IQR). Spearman rho correlation was used to examine relationships between total plaque area and stroke risk factors. Robust M—estimation was used to examine which risk factors predicted TPA after adjustment for other covariates.

Results: Of the 119 participants, 22 (18.5%) had no plaque and 97 (81.5%) had plaque, 100 (83.3%) were identified as high-risk (≥55 years with three risk factors for stroke) and 19 (15.8%) low-risk (≥55 years with fewer than three risk factors for stroke). Median participant age was 65 (IQR=11.0) years of age, 78.3% female. In univariate analyses, TPA was significantly associated with age (r s =.259;p=.005) and body mass index (BMI) (r s =-.300;p<.001). In a multivariable robust M-estimation model (including age, sex, BMI, systolic and diastolic blood pressure, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, hemoglobin A1c, physical activity, and categorical variables (yes/no) current smoker, history of high cholesterol, coronary artery disease, diabetes, hypertension, and transient ischemic attack), only age (p=.03), sex (p=.012), and hemoglobin A1c (p=.028) remained significant for predicting total plaque area (r 2 =16.5%).

Conclusion: Multivariate analysis demonstrated that age, sex, and hemoglobin A1c predicted TPA. Further work is needed to understand how both traditional and non-traditional stroke RFs may affect the risk of stroke in Native Americans.

Detailed insights into the formation pathway of CdS and ZnS in solution: a multi-modal in situ characterisation approach

The high stability, high availability, and wide size-dependent bandgap energy of sulphidic semiconductor nanoparticles (NPs) render them promising for applications in optoelectronic devices and solar cells. However, the tunability of their optical properties depends on the strict control of their crystal structure and crystallisation process. Herein, we studied the structural evolution during the formation of CdS and ZnS in solution by combining in situ luminescence spectroscopy, synchrotron-based X-ray diffraction (XRD) and pair distribution function (PDF) analyses for the first time. The influence of precursor type, concentration, temperature and heating program on the product formation and on the bandgap or trap emission were investigated in detail. In summary, for CdS, single-source precursor (SSP) polyol strategies using the dichlorobis(thiourea)cadmium(II) complex and double-source precursor approaches combining Cd(CH₃COO)₂·2H₂O and thiourea led to the straightforward product at 100 °C, while the catena((m₂-acetato-O,O')-(acetate-O,O')-(m₂-thiourea)-cadmium) complex was formed at 25 and 80 °C. For ZnS, the reaction between Zn(CH₃COO)₂·2H₂O and thiourea at 100 °C led to the product formation after the crystallisation and dissolution of an unknown intermediate. At 180 °C, besides an unknown phase, the acetato-bis(thiourea)-zinc(II) complex was also detected as a reaction intermediate. The formation of such reaction intermediates, which generally remain undetected applying only ex situ characterisation approaches, reinforce the importance of in situ analysis for promoting the advance on the production of tailored semiconductor materials.

Transcranial Color-Coded Doppler Cerebral Hemodynamics Following Aerobic Exercise Training: Outcomes From a Pilot Randomized Clinical Trial

Introduction

An active lifestyle with regular exercise is thought to decrease or delay the onset of Alzheimer dementia through increasing blood flow to the brain. We examined the mean flow velocity (MFV) and pulsatility index (PI) in the middle cerebral arteries of individuals randomized into two groups-a Usual Physical Activity (UPA) group and an Enhanced Physical Activity (EPA) exercise intervention group-to determine if exercise training is related to changes in cerebral blood flow.

Methods

We examined 23 participants, randomized into a UPA group (n=12) and an EPA group (n=11), with transcranial color-coded Doppler (TCCD) and cardiorespiratory fitness (VO2peak, mL/kg/min) testing at baseline and following a 26-week intervention. TCCD was used to measure MFV and PI. Participants in the EPA group completed supervised aerobic exercise training for 26 weeks. Kendall's tau b correlation was used to examine relationships between variables. The Wilcoxon Rank Sum tests were used to examine changes between the UPA and EPA groups.

Results

There was no significant change in MFV or PI in the UPA group or the EPA group (p-values >0.05) between baseline and 26 weeks; the change between the UPA and EPA groups was also not significant (p=0.603). There was no evidence of an association between change in VO2peak and change in MFV or PI (all p-values >0.05). Participants in the EPA group significantly increased their VO2peak compared to the UPA group (p=0.027).

Conclusion

This study did not demonstrate evidence of a significant change in the MFV in the middle cerebral arteries or evidence of a significant change in the PI between UPA and EPA groups. Future studies should be performed in larger cohorts and should consider use of personalized exercise programs to maximize understanding of how cerebrovascular hemodynamics change in structure and function with exercise for adults at risk for Alzheimer dementia.

Distinguishing exercise intolerance in early-stage pulmonary hypertension with invasive exercise hemodynamics: Rest VE /VCO2 and ETCO2 identify pulmonary vascular disease

BACKGROUND

Among subjects with exercise intolerance and suspected early-stage pulmonary hypertension (PH), early identification of pulmonary vascular disease (PVD) with noninvasive methods is essential for prompt PH management.

HYPOTHESIS

Rest gas exchange parameters (minute ventilation to carbon dioxide production ratio: VE /VCO2 and end-tidal carbon dioxide: ETCO2 ) can identify PVD in early-stage PH.

METHODS

We conducted a retrospective review of 55 subjects with early-stage PH (per echocardiogram), undergoing invasive exercise hemodynamics with cardiopulmonary exercise test to distinguish exercise intolerance mechanisms. Based on the rest and exercise hemodynamics, three distinct phenotypes were defined: (1) PVD, (2) pulmonary venous hypertension, and (3) noncardiac dyspnea (no rest or exercise PH). For all tests, *p < .05 was considered statistically significant.

RESULTS

The mean age was 63.3 ± 13.4 years (53% female). In the overall cohort, higher rest VE /VCO2 and lower rest ETCO2 (mm Hg) correlated with high rest and exercise pulmonary vascular resistance (PVR) (r ~ 0.5-0.6*). On receiver-operating characteristic analysis to predict PVD (vs. non-PVD) subjects with noninvasive metrics, area under the curve for pulmonary artery systolic pressure (echocardiogram) = 0.53, rest VE /VCO2  = 0.70* and ETCO2  = 0.73*. Based on this, optimal thresholds of rest VE /VCO2  > 40 mm Hg and rest ETCO2  < 30 mm Hg were applied to the overall cohort. Subjects with both abnormal gas exchange parameters (n = 12, vs. both normal parameters, n = 19) had an exercise PVR 5.2 ± 2.6* (vs. 1.9 ± 1.2), mPAP/CO slope with exercise 10.2 ± 6.0* (vs. 2.9 ± 2.0), and none included subjects from the noncardiac dyspnea group.

CONCLUSIONS

In a broad cohort of subjects with suspected early-stage PH, referred for invasive exercise testing to distinguish mechanisms of exercise intolerance, rest gas exchange parameters (VE /VCO2  > 40 mm Hg and ETCO2  < 30 mm Hg) identify PVD.

Increased RV:LV ratio on chest CT-angiogram in COVID-19 is a marker of adverse outcomes

BACKGROUND

Right ventricular (RV) dilation has been used to predict adverse outcomes in acute pulmonary conditions. It has been used to categorize the severity of novel coronavirus infection (COVID-19) infection. Our study aimed to use chest CT-angiogram (CTA) to assess if increased RV dilation, quantified as an increased RV:LV (left ventricle) ratio, is associated with adverse outcomes in the COVID-19 infection, and if it occurs out of proportion to lung parenchymal disease.

RESULTS

We reviewed clinical, laboratory, and chest CTA findings in COVID-19 patients (n = 100), and two control groups: normal subjects (n = 10) and subjects with organizing pneumonia (n = 10). On a chest CTA, we measured basal dimensions of the RV and LV in a focused 4-chamber view, and dimensions of pulmonary artery (PA) and aorta (AO) at the PA bifurcation level. Among the COVID-19 cohort, a higher RV:LV ratio was correlated with adverse outcomes, defined as ICU admission, intubation, or death. In patients with adverse outcomes, the RV:LV ratio was 1.06 ± 0.10, versus 0.95 ± 0.15 in patients without adverse outcomes. Among the adverse outcomes group, compared to the control subjects with organizing pneumonia, the lung parenchymal damage was lower (22.6 ± 9.0 vs. 32.7 ± 6.6), yet the RV:LV ratio was higher (1.06 ± 0.14 vs. 0.89 ± 0.07). In ROC analysis, RV:LV ratio had an AUC = 0.707 with an optimal cutoff of RV:LV ≥ 1.1 as a predictor of adverse outcomes. In a validation cohort (n = 25), an RV:LV ≥ 1.1 as a cutoff predicted adverse outcomes with an odds ratio of 76:1.

CONCLUSIONS

In COVID-19 patients, RV:LV ratio ≥ 1.1 on CTA chest is correlated with adverse outcomes. RV dilation in COVID-19 is out of proportion to parenchymal lung damage, pointing toward a vascular and/or thrombotic injury in the lungs.

MiRNA-149 as a Candidate for Facial Clefting and Neural Crest Cell Migration

Nonsyndromic cleft lip with or without palate (nsCL/P) ranks among the most common human birth defects and has a multifactorial etiology. Human neural crest cells (hNCC) make a substantial contribution to the formation of facial bone and cartilage and are a key cell type in terms of nsCL/P etiology. Based on increasing evidence for the role of noncoding regulatory mechanisms in nsCL/P, we investigated the role of hNCC-expressed microRNAs (miRNA) in cleft development. First, we conducted a systematic analysis of miRNAs expressed in human-induced pluripotent stem cell-derived hNCC using Affymetrix microarrays on cell lines established from 4 unaffected donors. These analyses identified 152 candidate miRNAs. Based on the hypothesis that candidate miRNA loci harbor genetic variation associated with nsCL/P risk, the genomic locations of these candidates were cross-referenced with data from a previous genome-wide association study of nsCL/P. Associated variants were reanalyzed in independent nsCL/P study populations. Jointly, the results suggest that miR-149 is implicated in nsCL/P etiology. Second, functional follow-up included in vitro overexpression and inhibition of miR-149 in hNCC and subsequent analyses at the molecular and phenotypic level. Using 3'RNA-Seq, we identified 604 differentially expressed (DE) genes in hNCC overexpressing miR-149 compared with untreated cells. These included TLR4 and JUNB, which are established targets of miR-149, and NOG, BMP4, and PAX6, which are reported nsCL/P candidate genes. Pathway analyses revealed that DE genes were enriched in pathways including regulation of cartilage development and NCC differentiation. At the cellular level, distinct hNCC migration patterns were observed in response to miR-149 overexpression. Our data suggest that miR-149 is involved in the etiology of nsCL/P via its role in hNCC migration.

National Trends in Heart Donor Usage Rates: Are We Efficiently Transplanting More Hearts?

Background

It is unclear whether the recent increase in the number of heart transplants performed annually in the United States is only because of higher availability of donors and if it affected recipients’ survival.

Methods and Results

We examined characteristics of donors and recipients from 2008 to 2012 (n=11 654) and 2013 to 2017 (n=14 556) and compared them with 2003 to 2007 (n=10 869). Cox models examined 30‐day and 1‐year risk of recipients’ death post transplant. From 2013 to 2017, there was an increase in the number of transplanted hearts and number of donor offers but an overall decline in the ratio of hearts transplanted to available donors. Donors between 2013 and 2017 were older, heavier, more hypertensive, diabetic, and likely to have abused illicit drugs compared with previous years. Drug overdose and hepatitis C positive donors were additional contributors to donor risk in recent years. In Cox models, risk of death post transplant between 2013 and 2017 was 15% lower at 30 days (hazard ratio [HR] 0.85; 95% CI, 0.74–0.98) and 21% lower at 1 year (HR, 0.79; 95% CI, 0.73–0.87) and between 2008 and 2012 was 9% lower at 30 days (HR, 0.91; 95% CI, 0.79–1.05) and 14% lower at 1 year (HR, 0.86; 95% CI, 0.79–0.94) compared with 2003 to 2007.

Conclusions

Despite a substantial increase in heart donor offers in recent years, the ratio of transplants performed to available donors has decreased. Even though hearts from donors who are older, more hypertensive, and have diabetes mellitus are being used, overall recipient survival continues to improve. Broader acceptance of drug overdose and hepatitis C positive donors may increase the number and percentage of heart transplants further without jeopardizing short‐term outcomes.

Survey of Dental Clinicians for Attitude and Use of Torque-Limiting Devices

PURPOSE

The purpose of this study was to survey practicing clinicians and determine if differences existed concerning their use of torque-limiting devices (TLDs) and screw-tightening protocols, comparing this with existing universal industry standards.

MATERIALS AND METHODS

A nine-question survey was administered with 428 dentists providing data for three specific areas: (1) demographic information-TLD ownership, device age, frequency of use, and observations of screw loosening; (2) recognition information-calibration, reading measurements of the TLD, and the meaning of preload; (3) usage information-screw-tightening protocols and effect of speed during actioning of the TLD. Data collection was compared with industry standards for use of hand torque tools including ISO-6789 1,2:2017 and related texts pertaining to screw fastener protocols.

RESULTS

The beam-type TLD was the most popular; however, 33% surveyed used it incorrectly. Most TLDs being used were older than 1 year, with only 6% calibrated. Forty-eight percent observed screw loosening less than once per year, while 44% reported three or more occurrences per year. A similar number used the TLD for implant placement and abutment screw tightening. Screw-tightening protocols varied. Preload was not understood by the majority of those surveyed.

CONCLUSION

Dentistry does not appear to adhere to the protocols and standards recommended by other industries that also rely on screw-fastening mechanisms and TLDs. Further education and training appears to be warranted in this area of implant dentistry to reduce the risks of screw-associated complications.

Heart and kidney transplant: should they be combined or subsequent?

AIMS

End-stage heart failure patients often present with severe kidney failure and have limited treatment options. We compared the clinical characteristics and outcomes among end-stage heart and kidney failure patients who underwent combined heart and kidney transplant (HKTx) with those who underwent kidney transplant after heart transplant (KAH).

METHODS AND RESULTS

All patients from 2007-2016 who underwent combined HKTx (n = 715) and those who underwent KAH (n = 130) using the United Network for Organ Sharing database were included. Kaplan-Meier curves and Cox models compared survivals and identified predictors of death. Number of combined HKTx performed annually in United States increased from 59 in 2007 to 146 in 2016 whereas KAH decreased from 34 in 2007 to 6 in 2016. Among KAH patients, average wait time for kidney transplant was 3.0 years, time to dialysis or to kidney transplant after heart transplant did not differ with varying severity of kidney disease at baseline (P for both >0.05). Upon follow-up (mean 3.5 ± 2.7 years), 151 patients died. In multivariable models, patients who underwent combined HKTx had 4.7-fold greater risk of death [95% confidence interval (CI) 2.4-9.4) than KAH patients upon follow up. A secondary analysis using calculation of survival only after kidney transplant for KAH patients still conferred higher risk for combined HKTx patients [hazard ratio (HR) 2.6 95% CI 1.33-5.15]. In subgroup analyses after excluding patients on dialysis (HR 3.99 95% CI 1.98-8.04) and analysis after propensity matching for age, gender, and glomerular filtration rate (HR 3.01 95% CI 1.40-6.43) showed similar and significantly higher risk for combined HKTx patients compared with KAH patients. Lastly, these results also remained unchanged after excluding transplant centres who performed only one type of procedure preferentially, i.e. HKTx or KAH (HR 4.70 95% CI 2.35-9.42).

CONCLUSIONS

National registry data show continual increase in combined HKTx performed annually in the United States but inferior survival compared with KAH patients. Differences in patient characteristics or level of kidney dysfunction at baseline do not explain these poor outcomes among HKTx patients compared with KAH patients. Consensus guidelines are greatly needed to identify patients who may benefit more from dual organ transplants.

Method to characterize a thermal diode in saturated steam atmosphere

We present a novel measurement method for the characterization of thermal diodes in a saturated steam atmosphere. A measuring setup has been developed in which two pressure sensors are integrated. Using a developed analytical model, the heat flow, the volume flow, and the cracking pressure are determined from the measured absolute pressures and the pressure difference. The analytical model was verified using a flow through an orifice. We first calculated the volume flow through the orifice, with a diameter of 3 mm, using the Reader-Harris equation and then compared it to experimentally determined values. The experimentally determined values showed a discrepancy of 9%. With the measurement setup, we have characterized a check valve developed for magnetocaloric heat pumps, which has a thermally rectifying behavior. The developed check valve consists of three spring arms, which are radially attached to a valve disk. The heat flow through the check valve in the forward direction is 166 W for water, 239 W for ethanol, and 547 W for methanol at a temperature difference of 1 K. In the reverse direction, the heat flow is -0.03 W at a temperature difference of -1 K. For methanol, this corresponds to a rectification coefficient of more than 18 000.

Vitamin D and bisphosphonate therapy in systemic lupus erythematosus patients who receive glucocorticoids: are we offering the best care?

OBJECTIVE

This study aimed to evaluate management practices for glucocorticoid (GC)-induced osteoporosis (GIOP) in systemic lupus erythematosus (SLE) patients using 2017 American College of Rheumatology guidelines as a gold standard.

METHODS

We conducted a retrospective cohort study using a clinical database from the years 2011 to 2016. SLE cases with >90 days continuous prednisone use at doses of ≥7.51 mg daily were identified. Osteoporosis risk factors were assessed via chart review. The Fracture Risk Assessment (FRAX) score was estimated for patients > 40 years of age. Vitamin D, bisphosphonate prescriptions, and osteoporotic (OP) fractures were ascertained through chart review. A classification tree was used to identify the key patient-related predictors of bisphosphonate prescription.

RESULTS

A total of 203 SLE patients met the inclusion criteria. The recommended dose of vitamin D supplement was prescribed to 58.9% of patients < 40 years of age and 61.5% of patients ≥ 40 years of age. Among patients aged ≥ 40 years, 25% were prescribed bisphosphonates compared to 36% who met indications for bisphosphonates per the ACR guidelines. Another 10% were prescribed a bisphosphonate, despite not having indication per the ACR guidelines, which was considered as overtreatment. Among patients aged ≥ 40 years, older age and a higher FRAX score for major OP fracture and hip fracture predicted bisphosphonate prescription. In a classification tree analysis, patients with FRAX scores (for major OP fracture) of ≥ 23.5% predicted bisphosphonate prescription in this SLE population. Among patients who had OP fractures in the follow-up period, nine (6.50%) were inpatients receiving appropriate GIOP care versus 12 (13.6%) who were inpatients not receiving ACR-appropriate care (p = 0.098).

CONCLUSIONS

In clinical practice, fewer SLE patients with or at risk for GIOP are prescribed vitamin D and bisphosphonates than recommended by the 2017 ACR guidelines. Also, in this study, another 10% were prescribed a bisphosphonate, despite not having an indication per the ACR guidelines. Patients were most likely to receive a bisphosphonate prescription if they had a major OP FRAX score of > 23.5%.

[Evaluation of a prostate cancer E‑health tutorial : Development and testing of the website prostata-information.ch]

BACKGROUND

Due to the multitude of therapy options, the treatment decision after diagnosis of localized prostate cancer is challenging. Compared to printed booklets, web-based information technology offers more possibilities to tailor information to patients' individual needs.

OBJECTIVES

To support the decision-making process as well as the communication with patients, we developed an online tutorial in a systematic process in the German-speaking part of Switzerland and then tested it in a pilot study. The study investigated users' satisfaction, the coverage of information needs, the preparation for decision making, and the subjective quality of the decision.

MATERIALS AND METHODS

Based on already existing information material, the online tutorial was developed in an iterative process using focus groups with patients and urologists. For the following evaluation in eight clinics a total of 87 patients were invited to access the platform and participate in the study. Of these patients, 56 used the tutorial and 48 answered both surveys (the first one 4 weeks after the first login and the second one 3 months after treatment decision). The surveys used the Preparation for Decision Making Scale (PDMS), the Decisional Conflict Scale (DCS), and the Decisional Regret Scale (DRS).

RESULTS AND CONCLUSION

Satisfaction with the tutorial is very high among patients with newly diagnosed localized prostate cancer. Users find their information needs sufficiently covered. Three months after the decision they felt that they were well prepared for the decision making (mean PDMS 75, standard deviation [SD] 23), they had low decisional conflict (mean DCS 9.6, SD 11), and almost no decisional regret (mean DRS 6.4, SD 9.6). Based on these findings, further use of the tutorial can be recommended.

A randomized controlled trial of probiotics for Clostridium difficile infection in adults (PICO)

Background

Clostridium difficile is the most common cause of hospital-acquired infections, responsible for >450000 infections annually in the USA. Probiotics provide a promising, well-tolerated adjunct therapy to standard C. difficile infection (CDI) treatment regimens, but there is a paucity of data regarding their effectiveness for the treatment of an initial CDI.

Objectives

We conducted a pilot randomized controlled trial of 33 participants from February 2013 to February 2015 to determine the feasibility and health outcomes of adjunct probiotic use in patients with an initial mild to moderate CDI.

Methods

The intervention was a 28 day, once-daily course of a four-strain oral probiotic capsule containing Lactobacillus acidophilus NCFM, Lactobacillus paracasei Lpc-37, Bifidobacterium lactis Bi-07 and B. lactis Bl-04. The control placebo was identical in taste and appearance. Registered at clinicaltrials.gov: trial registration number = NCT01680874.

Results

Probiotic adjunct therapy was associated with a significant improvement in diarrhoea outcomes. The primary duration of diarrhoea outcome (0.0 versus 1.0 days; P = 0.039) and two exploratory outcomes, total diarrhoea days (3.5 versus 12.0 days; P = 0.005) and rate of diarrhoea (0.1 versus 0.3 days of diarrhoea/stool diary days submitted; P = 0.009), all decreased in participants with probiotic use compared with placebo. There was no significant difference in the rate of CDI recurrence or functional improvement over time between treatment groups.

Conclusions

Probiotics are a promising adjunct therapy for treatment of an initial CDI and should be further explored in a larger randomized controlled trial.

Effect of Lactobacillus rhamnosus HN001 on carriage of Staphylococcus aureus: results of the impact of probiotics for reducing infections in veterans (IMPROVE) study

BACKGROUND

Infection by Staphylococcus aureus (S. aureus) is a major cause of morbidity and mortality. Colonization by S. aureus increases the risk of infection. Little is known about decolonization strategies for S. aureus beyond antibiotics, however probiotics represent a promising alternative. A randomized controlled trial was conducted to determine the efficacy of Lactobacillus rhamnosus (L. rhamnosus) HN001 in reducing carriage of S. aureus at multiple body sites.

METHODS

One hundred thirteen subjects, positive for S. aureus carriage, were recruited from the William S. Middleton Memorial Medical Center, Madison, WI, USA, and randomized by initial site of colonization, either gastrointestinal (GI) or extra-GI, to 4-weeks of oral L. rhamnosus HN001 probiotic, or placebo. Nasal, oropharyngeal, and axillary/groin swabs were obtained, and serial blood and fecal samples were collected. Differences in prevalence of S. aureus carriage at the end of the 4-weeks of treatment were assessed.

RESULTS

The probiotic and placebo groups were similar in age, gender, and health history at baseline. S. aureus colonization within the stool samples of the extra-GI group was 15% lower in the probiotic than placebo group at the endpoint of the trial. Those in the probiotic group compared to the placebo group had 73% reduced odds (OR 0.27, 95% CI 0.07-0.98) of methicillin-susceptible S. aureus presence, and 83% reduced odds (OR 0.17, 95% CI 0.04-0.73) of any S. aureus presence in the stool sample at endpoint.

CONCLUSION

Use of daily oral L. rhamnosus HN001 reduced odds of carriage of S. aureus in the GI tract, however it did not eradicate S. aureus from other body sites.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01321606 . Registered March 21, 2011.

Grazing management of mixed alfalfa bermudagrass pastures

Rotational grazing management is commonly recommended to improve persistence of legumes interseeded into bermudagrass, but impacts on animal performance are poorly understood. Steers (n = 365, BW = 249 ± 22.9 kg) grazed mixed alfalfa (Medicago sativa L.)/bermudagrass (Cynodon dactylon [L.] Pers.) pastures (n = 10; 1.6-ha) with either continuous grazing (CONT) or rotational grazing (ROT) management over 3 yr. Initial stocking rate was set at 6.25 steers/ha. When forage allowance of CONT became limiting in mid-July each year, 2 randomly selected steers were removed from all pastures to maintain equal stocking rates in CONT and ROT. Rotational grazing pastures were divided into 8 paddocks with 3-d grazing and 21-d rest between grazing events. Initial, final, and interim (28-d) BW were collected following a 16-h removal from feed and water. Data were analyzed as a repeated measures experiment with completely random design using the mixed procedure of SAS (SAS Inst. Inc., Cary, NC) using pasture within treatment by year in the random statement. Across years, steer BW did not differ (P ≥ 0.47) at the midpoint or end of the grazing season. Daily BW gains during the early summer period tended (P = 0.10) to be 0.11 kg greater for CONT than ROT in yr 1, but did not differ (P ≥ 0.24) in yr 2 and 3. In the late summer, ADG was 0.15 kg less (P < 0.01) for CONT than ROT in yr 1, were not different (P = 0.23) in yr 2, and were 0.29 kg less (P < 0.01) for CONT than ROT in yr 3. Over the entire experimental period, ADG did not differ (P ≥ 0.67) in yr 1 or 2, but tended (P = 0.09) to be 0.10 kg greater for ROT than CONT in yr 3. Forage mass of ROT was greater (P < 0.01) than CONT throughout the grazing season. Because stocking rates were maintained at the same level, ROT pastures provided greater (P < 0.01) forage allowance during the grazing season than CONT explaining differences in ADG between treatments. Alfalfa stand percentage did not differ (P = 0.79) at the beginning of the experiment, but was less (P ≤ 0.03) for CONT than ROT at all other sampling dates. These data indicate that at equal stocking rates, ROT can maintain greater alfalfa persistence, forage nutritive quality, and forage allowance compared with continuous grazing and provided increased animal performance during the late summer when the alfalfa stand was reduced in CONT pastures.

Replacing synthetic N with clovers or alfalfa in bermudagrass pastures. 2. Herbage nutritive value for growing beef steers

The objective of this study was to evaluate the effects of including alfalfa (ALF, Medicago sativa L.) or a combination of white (Trifolium repens L.) and red (Trifolium pretense L.) clovers (CLVR) inter-seeded into bermudagrass (Cynodon dactylon L. Pers.) on herbage nutritive value compared with monocultures of bermudagrass fertilised with 0 (0N), 56 (56N), or 112 (112N) kg nitrogen (N)/ha over four grazing seasons. At the end of the fourth year (during the winter), legume plants in ALF and CLVR were killed and the carryover N benefit on bermudagrass nutritive value was evaluated during the fifth year. Pre-grazing herbage of all pastures exceeded the dietary recommendations for growing steers to maintain 0.9 kg/day average daily liveweight gain for crude protein and total digestible nutrients, 118 and 617 g kg/DM, respectively. Post-grazing herbage in ALF was below 600 g/kg total digestible nutrients at all times during the grazing season, post-grazing total digestible nutrients of CLVR was below 600 g/kg during the late summer and autumn. Post-grazing herbage of monoculture bermudagrass pastures fell below 600 g/kg in the middle of summer regardless of N fertilisation. Carryover N benefits of legumes were similar to 112N in the early summer, but were not different than 0N and 56N during the late summer and autumn. Replacing applications of synthetic N in bermudagrass swards with inter-seeding of either clovers or alfalfa produce herbage with equivalent nutritive value to heavily N fertilised monocultures of bermudagrass during the early summer, and similar to moderately N fertilised in the late summer and autumn. The inclusion of legumes in bermudagrass swards can reduce the reliance on synthetic N fertilisation with little overall effect on herbage nutritive quality possibly decreasing environmental impacts of grazing production systems.

Replacing synthetic N with clovers or alfalfa in bermudagrass pastures. 3. Performance of growing steers

The objective of this study was to evaluate the performance of steers (n = 590, 263 ± 30.6 kg) grazing alfalfa (ALF, Medicago sativa L.) or a combination of white (Trifolium repens L.) and red (Trifolium pretense L.) clovers (CLVR) inter-seeded into bermudagrass (Cynodon dactylon L. Pers.) pastures compared with fertilisation with 0 (0N), 56 (56N), or 112 (112N) kg nitrogen (N)/ha (n = 4, 0.8-ha pastures per treatment) in north-east Arkansas (USA) over 4 years. The carryover N benefit of CLVR or ALF was compared with N fertilisation rates during the fifth year on performance of growing steers (n = 120; 235 ± 22.6 kg). Average daily gain increased with N application rate and legume pastures were similar to 56N; but liveweight gain per steer grazing legume pastures tended to be greater than 112N. Steer grazing days per hectare and liveweight gain per hectare were greater for ALF and CLVR than bermudagrass monocultures regardless of N fertilisation rate. Steer average daily gain, grazing days per hectare and liveweight gain per hectare for carryover N from legumes did not differ from 56N. These results indicate that replacing synthetic N by inter-seeding legumes into bermudagrass swards has the potential to improve individual animal performance and production per unit area and carryover benefits of legume N may be equivalent to 56 kg N/ha.

Replacing synthetic N with clovers or alfalfa in bermudagrass pastures. 1. Herbage mass and pasture carrying capacity

The objective of this study was to evaluate the effects of including alfalfa (ALF, Medicago sativa L.) or a combination of white (Trifolium repens L.) and red (Trifolium pretense L.) clovers (CLVR) inter-seeded into bermudagrass (Cynodon dactylon L. Pers.) on herbage nutritive value compared with monocultures of bermudagrass fertilised with 0 (0N), 56 (56N), or 112 (112N) kg nitrogen (N)/ha over four grazing seasons. In autumn, at the end of the fourth year and in the spring before the fifth grazing season, alfalfa and clover plants were killed and the carryover N benefit of CLVR or ALF was compared with N fertilisation rates during the fifth year. Across years, N fertilisation rate increased herbage mass and carrying capacity linearly; whereas herbage production from CLVR and ALF swards was equivalent to 56N, were greater than 0N and less than 112N. Herbage mass in CLVR and ALF swards was greater than fertilised bermudagrass swards in the spring and did not differ from fertilised bermudagrass in the early summer. In late summer herbage accumulation of CLVR and ALF swards appeared to decrease, limiting the herbage mass in the legume pastures compared with 56N and 112N. Carrying capacity of CLVR and ALF swards was greater than fertilised bermudagrass in the spring and early summer, but did not differ from fertilised swards in the late summer. The N benefit of including legumes in bermudagrass swards can alleviate the reliance on synthetic N fertilisation with little overall effect on pasture carrying capacity.

Impact of Probiotics for Reducing Infections in Veterans (IMPROVE): Study protocol for a double-blind, randomized controlled trial to reduce carriage of Staphylococcus aureus

BACKGROUND

Staphylococcus aureus (S. aureus) is an organism of great public health importance, causing 20,000 deaths annually. Decolonization of patients with S. aureus may prevent infections, yet current options are limited to antimicrobials that promote antibiotic resistance and can cause adverse side effects. Probiotics have potential to reduce colonization of pathogenic bacteria, representing a promising alternative for S. aureus decolonization, but thus far lack rigorous evaluation.

METHODS

Potential subjects were recruited from inpatient and outpatient settings within a VA medical center and screened for S. aureus gastrointestinal (GI) or extra-GI colonization using swabs at multiple body sites. Positive, eligible, consenting participants were stratified by colonization site and randomized in a 1:1 ratio to 4-weeks of daily placebo or Lactobacillus rhamnosus (L. rhamnosus) HN001 probiotic treatment. Blood and stool samples, and treatment adherence reports were collected from each subject throughout the study, along with a final set of swabs at study completion to detect S. aureus carriage. The outcomes of this study are GI or extra-GI carriage by S. aureus at the end of 4weeks of therapy, change in phagocytic activity of polymorphonuclear cells from pre-intervention to post-intervention, and symptomatic S. aureus infection at any site during the study period.

CONCLUSION

114 participants have been recruited for this study. Analysis of outcomes is underway. This is the first clinical trial to examine the efficacy of L. rhamnosus HN001 for decolonization of S. aureus, and investigates the mechanism by which L. rhamnosus HN001 mediates its effect on S. aureus colonization. ClinicalTrials.govIdentifier NCT01321606.

Emerging role of fecal microbiota therapy in the treatment of gastrointestinal and extra-gastrointestinal diseases

In the recent decade our understanding of the role of the human gut microbiome has been revolutionized by advances in development of molecular methods. Approximately, up to 100 trillion (10(14)) microorganisms per human body colonize the intestinal tract making an additional acquired organ that provides many vital functions to the host. A healthy gut microbiome can be defined by the presence of the various classes of microbes that enhance metabolism, resistance to infection and inflammation, prevention against cancer and autoimmunity and that positively influence so called braingut axis. Diet represents one of the most important driving forces that besides environmental and genetic factors, can define and influence the microbial composition of the gut. Aging process due to different changes in gut physiology (i.e. gastric hypochlorhydria, motility disorders, use of drugs, degenerative changes in enteric nervous system) has a profound effect on the composition, diversity and functional features of gut microbiota. A perturbed aged gut microbiome has been associated with the increasing number of gastrointestinal (e.g. Clostridium difficile infection - CDI) and non-gastrointestinal diseases (metabolic syndrome, diabetes mellitus, fatty liver disease, atherosclerosis etc.). Fecal microbiota transplantation (FMT) is a highly effective method in the treatment of refractory CDI. FMT is the term used when stool is taken from a healthy individual and instilled during endoscopy (colonoscopy or enteroscopy) into a gut of the sick person to cure certain disease. FMT represents an effective therapy in patient with recurrent CDI and the effectiveness of FMT in the prevention of CDI recurrence had reached approx. 90%. There is also an increasing evidence that the manipulation of gut microbiota by FMT represents a promising therapeutic method in patients with inflammatory bowel disease and irritable bowel syndrome. There is also an increased interest in the role of FMT for the treatment of metabolic syndrome and obesity which collectively present the greatest health challenge in the developed world nowadays. Targeting of gut microbiota by FMT represents an exciting new frontier in the prevention and management of gastrointestinal and non-gastrointestinal diseases that awaits further studies in preclinical and clinical settings.

Time-varying signal analysis to detect high-altitude periodic breathing in climbers ascending to extreme altitude

This work investigates the performance of cardiorespiratory analysis detecting periodic breathing (PB) in chest wall recordings in mountaineers climbing to extreme altitude. The breathing patterns of 34 mountaineers were monitored unobtrusively by inductance plethysmography, ECG and pulse oximetry using a portable recorder during climbs at altitudes between 4497 and 7546 m on Mt. Muztagh Ata. The minute ventilation (VE) and heart rate (HR) signals were studied, to identify visually scored PB, applying time-varying spectral, coherence and entropy analysis. In 411 climbing periods, 30-120 min in duration, high values of mean power (MP(VE)) and slope (MSlope(VE)) of the modulation frequency band of VE, accurately identified PB, with an area under the ROC curve of 88 and 89%, respectively. Prolonged stay at altitude was associated with an increase in PB. During PB episodes, higher peak power of ventilatory (MP(VE)) and cardiac (MP(LF)(HR) ) oscillations and cardiorespiratory coherence (MP(LF)(Coher)), but reduced ventilation entropy (SampEn(VE)), was observed. Therefore, the characterization of cardiorespiratory dynamics by the analysis of VE and HR signals accurately identifies PB and effects of altitude acclimatization, providing promising tools for investigating physiologic effects of environmental exposures and diseases.

Advance directives among people living with HIV: room for improvement

While HIV has become a largely chronic disease, age-associated comorbidities are prevalent in people living with HIV (PLWH). Therefore, PLWH are appropriate for advance care planning (ACP) and advance directives (ADs) completion. We sought to characterize AD completion among outpatient PLWH. We conducted a retrospective chart review of PLWH who receive their routine care at the University of Wisconsin HIV clinic. Data were extracted from the electronic health record. Variables were entered into a stepwise multivariate logistic regression model to assess which factors were independently associated with AD completion. Five hundred and eighty eight charts were reviewed. Eighty-one percent of subjects were male and 72% were white; mean age was 46.8 years. ADs were completed by 134 subjects and 6.7% of those were completed at the HIV clinic. In the final multivariate model, those who had completed an AD were more likely to be older than age 45; ever been diagnosed with AIDS; have cardiovascular disease, neurologic disorder, chronic kidney disease, or malignancy. In this study, a small percentage of patients had documented ADs, with only a small proportion completed in the HIV clinic. The HIV clinic is an underutilized resource to offer ACP. Interventions are needed to provide the necessary ACP resources for PLWH.

Is a single positive blood culture for Enterococcus species representative of infection or contamination?

Data on the clinical outcomes of patients with a single compared with multiple positive blood cultures for Enterococcus species is limited. We undertook a retrospective cohort study in adults with at least one positive blood culture for Enterococcus species in a single institution. Clinical outcomes included death and elimination of infection. We included 471 positive blood cultures from 206 enterococcal positive blood culture episodes in 189 patients. Multiple positive blood cultures for Enterococcus species occurred in 110/206 (53.4 %) episodes; 31.6 % of patients had diabetes mellitus; 42.9 % of patients had solid or hematologic malignancy; 26.5 % of patients were solid organ transplant recipients; hospital-acquired and healthcare-associated acquisition represented 55.3 % and 33.0 % of episodes, respectively. Thirty-five patients died and 110 episodes of enterococcal bloodstream infection were successfully treated. In the multivariable analysis, multiple positive blood cultures were not statistically significantly associated with an increased likelihood of in-hospital death [odds ratio (OR) 1.00, 95 % confidence interval (CI) 0.42-2.40] or elimination (OR 1.41, 95 % CI 0.76-2.64) compared with single positive blood cultures. Hematologic malignancy and diabetes mellitus were independently associated with in-hospital death (OR 2.83, 95 % Cl 1.02-7.82; OR 2.79, 95 % Cl 1.16-6.70, respectively). Infectious disease consultation was associated with a greater likelihood of elimination (OR 2.50, 95 % Cl 1.32-4.72). The clinical outcomes of patients with single versus multiple positive blood cultures with Enterococcus species were similar in our institution. Further studies should examine efficient methods to detect contamination versus true infection.

Additive effects of growth promoting technologies on performance of grazing steers and economics of the wheat pasture enterprise

This research was designed to evaluate the effect of monensin (Elanco Animal Health, Greenfield, IN) supplementation via mineral or pressed protein block with or without a growth-promoting implant on performance of steers grazing wheat pasture in Arkansas over 2 yr. Preconditioned steers (n = 360, BW = 238 ± 5.1 kg) grazed 15 1.6-ha wheat pastures in the fall (n = 60 steers each fall, stocking rate of 2.5 steers/ha) or 30 0.8-ha wheat pastures in the spring (n = 120 steers each spring, stocking rate of 5 steers/ha). Steers in each pasture were given free-choice access to nonmedicated mineral (CNTRL; MoorMan's WeatherMaster Range Minerals A 646AAA; ADM Alliance Nutrition, Inc., Quincy, IL), or were supplemented with monensin (Elanco Animal Health, Greenfield, IN) via mineral containing 1.78 g monensin/kg (RMIN; MoorMan's Grower Mineral RU-1620 590AR; ADM Alliance Nutrition, Inc.), or pressed protein block containing 0.33 g monensin/kg (RBLCK; MoorMan's Mintrate Blonde Block RU; ADM Alliance Nutrition, Inc.). Additionally, one-half of the steers in each pasture were implanted (IMPL) with 40 mg trenbolone acetate and 8 mg estradiol (Component TE-G with Tylan; Elanco Animal Health). There was no interaction (P ≥ 0.71) between supplement treatment and growth-promoting implants, and ADG for RMIN and RBLCK were increased (P < 0.01) over CNTRL by 0.07 to 0.09 kg/d, respectively. Implanting steers with Component TE-G increased (P < 0.01) ADG by 0.14 kg/d. The combination of these growth-promoting technologies are a cost-effective means of increasing beef production by 22% without increasing level of supplementation or pasture acreage. Utilizing ionophores and implants together for wheat pasture stocker cattle decreased cost of gain by 26%. Utilizing both IMPL and monensin increased net return by $30 to $54/steer for RMIN or $18 to $43/steer for RBLCK compared with UNIMPL CNTRL at Low and High values of BW gain, respectively.

Periodic breathing during ascent to extreme altitude quantified by spectral analysis of the respiratory volume signal

High altitude periodic breathing (PB) shares some common pathophysiologic aspects with sleep apnea, Cheyne-Stokes respiration and PB in heart failure patients. Methods that allow quantifying instabilities of respiratory control provide valuable insights in physiologic mechanisms and help to identify therapeutic targets. Under the hypothesis that high altitude PB appears even during physical activity and can be identified in comparison to visual analysis in conditions of low SNR, this study aims to identify PB by characterizing the respiratory pattern through the respiratory volume signal. A number of spectral parameters are extracted from the power spectral density (PSD) of the volume signal, derived from respiratory inductive plethysmography and evaluated through a linear discriminant analysis. A dataset of 34 healthy mountaineers ascending to Mt. Muztagh Ata, China (7,546 m) visually labeled as PB and non periodic breathing (nPB) is analyzed. All climbing periods within all the ascents are considered (total climbing periods: 371 nPB and 40 PB). The best crossvalidated result classifying PB and nPB is obtained with Pm (power of the modulation frequency band) and R (ratio between modulation and respiration power) with an accuracy of 80.3% and area under the receiver operating characteristic curve of 84.5%. Comparing the subjects from 1(st) and 2(nd) ascents (at the same altitudes but the latter more acclimatized) the effect of acclimatization is evaluated. SaO(2) and periodic breathing cycles significantly increased with acclimatization (p-value &#60; 0.05). Higher Pm and higher respiratory frequencies are observed at lower SaO(2), through a significant negative correlation (p-value &#60; 0.01). Higher Pm is observed at climbing periods visually labeled as PB with > 5 periodic breathing cycles through a significant positive correlation (p-value &#60; 0.01). Our data demonstrate that quantification of the respiratory volume signal using spectral analysis is suitable to identify effects of hypobaric hypoxia on control of breathing.