Comparison of manual compression, Z-stitch, and suture-mediated vascular closure device techniques in dogs undergoing percutaneous transvenous intervention.

INTRODUCTION/OBJECTIVES: Manual compression has been standard of care for maintaining hemostasis after percutaneous endovascular intervention, but can be time-consuming and associated with vascular complications. Alternative closure methods include the figure-of-eight suture (Z-stitch) and vascular closure device (VCD) techniques. We hypothesized that compared to manual compression, Z-stitch and VCD would significantly reduce time-to-hemostasis after transvenous access, and the proportion of dogs with vascular patency would not differ significantly among treatments. ANIMALS: Forty-six client-owned dogs undergoing percutaneous transvenous interventional procedures. MATERIALS AND METHODS: Dogs with vessel diameter <5 mm were randomized to undergo manual compression or Z-stitch, while those with vessel diameter ≥5 mm were randomized to undergo manual compression, Z-stitch, or VCD. Time-to-hemostasis, bleeding scores, presence of vascular patency one day and two to three months post-procedure, and complications were recorded. Data are presented as median (95% confidence interval). RESULTS: In all 46 dogs, the right external jugular vein was used. Time-to-hemostasis was significantly shorter in the Z-stitch (2.1 [1.8-2.9] minutes) compared to VCD (8.6 [6.1-11.8] minutes; P<0.001) and manual compression (10.0 [10.0-20.0] minutes; P<0.001) groups. Time-to-hemostasis was significantly shorter in the VCD vs. manual compression (P=0.027) group. Bleeding scores were significantly greater at 5 and 10 min (P<0.001 and 0.013, respectively) in manual compression, compared to Z-stitch group. There was no difference in the proportion of dogs with vascular patency between groups (P=0.59). CONCLUSIONS: Z-stitch and VCD are effective venous hemostasis methods after percutaneous transvenous intervention, with Z-stitch providing the most rapid time-to-hemostasis. Both Z-stitch and VCD techniques have low complication rates and effectively maintain vascular patency.

Single- and multiple-dose pharmacokinetics of sotalol hydrochloride in healthy cats.

INTRODUCTION/OBJECTIVES: The objective of this study was to describe the single- and multiple-dose pharmacokinetics and urinary elimination of sotalol in healthy cats. ANIMALS: Six adult purpose-bred cats MATERIALS AND METHODS: Cats were administered 2 mg sotalol/kg body weight as a single intravenous bolus and as a single oral dose in a randomized crossover study with a two-week washout period. The same cats then received 3 mg sotalol/kg orally every 12 h for two weeks. Blood samples were collected at predetermined time points for 48 h postdose for quantification of sotalol using ultra-high-pressure liquid chromatography with mass spectrometry. Non-compartmental analysis was used to obtain pharmacokinetic parameters. Data are presented as median (min-max). RESULTS: Following intravenous administration, plasma clearance and volume of distribution were 9.22 mL/min/kg (5.69-10.89 mL/min/kg) and 2175.56 mL/kg (1961-2341.57 mL/kg), respectively. Bioavailability was 88.41% (62.75-130.29) following a single oral dose. Peak plasma concentration (Cmax) and time to Cmax were 0.94 µg/mL (0.45-1.17 µg/mL) and 1.5 h (0.5-4 h) after a single oral dose (2 mg/kg), and 2.29 µg/mL (1.91-2.48 µg/mL) and 1.0 h (0.5-1.5 h) with chronic oral dosing (3 mg/kg), respectively. Elimination half-life was 2.75 h (2.52-4.10 h) and 4.29 h (3.33-5.53 h) for single and chronic oral dosing, respectively. Accumulation index was 1.17 (1.09-1.29) after chronic dosing. Urinary sotalol recovery was 81-108% of the intravenous dose. CONCLUSIONS: Oral sotalol administration resulted in plasma concentrations reportedly efficacious in other species, with good to excellent oral bioavailability. Urinary excretion appears to be a major route of elimination. Following repeated oral dosing, minimal drug accumulation was estimated. Additional studies in cats are recommended due to the possibility of nonlinear kinetics.

Cross-Sectional Analysis of Ground Reaction Forces During Jumps in Professional Baseball Players.

ABSTRACT: Amonette, WE, Vazquez, J, and Coleman, AE. Cross-sectional analysis of ground reaction forces during jumps in professional baseball players. J Strength Cond Res 37(8): 1616-1622, 2023-This study described and compared force plate kinetics in major (MLB) and minor (MiLB) baseball players while performing vertical jumps (CMVJ), squat jumps (SSJ), and depth jumps (DJ). Second, comparisons were made between playing positions. Data were collected on 101 professional baseball players. Peak force, eccentric and concentric impulses, peak power, and jump height were determined from each test. Reactive strength index was computed from the DJ. Data were compared using factorial analysis of variances, alpha was set at p ≤ 0.05, and effect sizes were reported using Cohen's d . During CMVJ, MiLB players generated more force ( p = 0.04; d = 0.48), power ( p = 0.02; d = 0.42), and jumped higher ( p = 0.03; d = 0.32) than MLB players. Pitchers generated higher propulsive impulses than catchers ( p = 0.004; d = 0.93). Outfielders generated more power ( p = 0.02; d = 0.98) and jumped higher ( p = 0.049; d = 1.08) than catchers and infielders ( p = 0.025; d = 0.32). Minor league baseball players generated more force ( p = 0.002; d = 0.62), power ( p = 0.001; d = 0.84), and jumped higher ( p = 0.02; d = 0.48) than MLB players in SSJ. No differences were observed by position in SSJ. Minor league baseball players jumped higher than MLB players in the DJ ( p = 0.01; d = 0.57) and outfielders generated more power in the DJ than pitchers ( p = 0.05; d = 0.43) and catchers ( p = 0.007; d = 1.61). Reactive strength index was greater in outfielders compared with catchers ( p = 0.01; d = 1.20). These data indicate that MiLB players were generally more powerful and jumped higher than MLB players in the 3 performance tasks. The difference observed by playing level were likely related to physical preparedness at the beginning of spring training; positional differences were the result of athletic skill sets required for tactical excellence at each position.

Parent-infant interaction quality is related to preterm status and sensory processing.

BACKGROUND: Parent-infant interactions provide the foundation for the development of infant socioemotional wellbeing. Preterm birth can have a substantial, and often detrimental, impact on the quality of early parent-infant interactions. Sensory processing difficulties, common in preterm infants, are further associated with poorer interaction quality. There is a paucity of research, however, examining the links between the quality of parent-infant interaction, preterm birth, and sensory processing difficulties. This study aimed to characterise the quality of interactions of parent-infant dyads involving preterm infants who may display sensory processing differences and examine the associations between parent-infant interaction quality, preterm status and infant sensory processing. METHOD: 67 parent-infant dyads (12-months infant age, 22 preterm, 45 full-term) participated in a recorded, semi-structured 15-minute play interaction. Parents also filled out questionnaires on demographics, and infant sensory processing (Infant and Toddler Sensory Profile-2; ITSP-2). Interaction quality was rated using the Parenting Interactions with Children: Checklist of Observations Linked to Outcomes (PICCOLO). RESULTS: Preterm and full-term infants differed in sensory processing and parent-infant interaction. Infant prematurity was associated with the sensory domains of; visual (r = - 0.37, p = .005), touch (r = - 0.39, p = .002), and movement (rs = - .32, p = .01), as well as the interaction domains of; responsivity (rs;= - .43, p = .001), teaching (rs = - .31, p = .02), and interaction total score (r = - 0.34, p = .01). Interaction quality was related to sensory registration (rs = - .38, p = .008), auditory (rs = - .34, p = .02), seeking (rs = .29, p = .05) and sensory behavioural scores (rs = - .52, p < .001). Overall, interaction quality was best predicted by infant prematurity and auditory scores, R2 = .15, F(1, 47) = 4.01, p = .02. DISCUSSION: Preterm infants differed from their full-term peers in both their sensory processing and in their dyadic interactions with parents. Preterm status was associated with less responsivity and teaching and was found to predict overall interaction quality. Poorer infant sensory processing was associated with less parental teaching, affection and responsivity during interactions. Our results suggest that preterm birth is related to sensory processing difficulties, and that prematurity and sensory processing are differentially associated with aspects of interaction quality. These findings support the further examination of the interplay between preterm birth, sensory processing, and parent-infant interaction quality.

Training on a virtual reality cricothyroidotomy simulator improves skills and transfers to a simulated procedure.

Objective: The virtual airway skills trainer (VAST) is a virtual reality simulator for training in cricothyroidotomy (CCT). The goal of the study is to test the effectiveness of training and transfer of skills of the VAST-CCT. Methods: Two groups, control (no training) and simulation (2 weeks of proficiency-based training), participated in this study. Subjects in the control condition did not receive any training on the task whereas those in the simulation received a proficiency-based training on the task during a period of 2 weeks. Two weeks post-training, both groups performed CCT on the TraumaMan to demonstrate the transfer of skills. Results: A total of (n=20) subjects participated in the study. The simulation group performed better than the control group at both the post-test (p<0.001) and retention test (p<0.001) on the simulator. The cumulative sum analysis showed that all subjects in the simulation group reached proficiency with acceptable failure rate within the 2 weeks of training. On the transfer test, the simulation group performed better on skin cut (p<0.001), intubation (p<0.001) and total score (p<0.001) than the control group. Conclusions: The VAST-CCT is effective in training and skills transfer for the CCT procedure. Level of evidence: Not applicable. Simulator validation study.

Transcatheter closure of patent ductus arteriosus in 11 dogs and one cat after incomplete or aborted surgical ligation.

OBJECTIVE: To describe the characteristics and outcomes of transcatheter patent ductus arteriosus (PDA) occlusion after incomplete or aborted surgical ligation in dogs and cats. ANIMALS: Twelve client-owned animals (11 dogs and one cat). MATERIALS AND METHODS: This retrospective study describes data from animals with aborted or incomplete surgical PDA ligation that subsequently underwent transcatheter closure using endovascular methods. Patient demographics, reason for incomplete or aborted surgery, complications, and method of transcatheter occlusion were recorded. Data are presented as mean ± standard deviation or median (interquartile range), where appropriate. RESULTS: For all cases, median age at surgery was 12.2 months (4.9-15.1 months) and at catheterization was 15.4 months (8.9-21.9 months), with 79 days (29-209 days) between surgical and interventional procedures. Median weight at catheterization was 4.5 kg (2.5-12.6 kg). Reasons for failed surgical ligation included hemorrhage during ductal dissection in seven dogs, residual flow in four dogs, and inability to identify the ductus in one cat. Transcatheter closure was successfully performed using a canine duct occluder in eight dogs, transarterial coil embolization in two dogs, and transvenous coil embolization in one dog and one cat. Metallic hemoclips partially obscured angiographic findings in three cases with prior surgical hemorrhage but did not prevent transcatheter closure. In all cases, ductal flow was successfully attenuated, with no or trace residual shunting on angiography and complete occlusion the following day on echocardiography. CONCLUSIONS: When surgery is unsuccessful, either owing to hemorrhage or residual flow, transcatheter closure of PDA is feasible, even in small patients.

Improving Equity of Care for Patients with Limited English Proficiency Using Quality Improvement Methodology.

Disparate clinical outcomes have been reported for patients with Limited English Proficiency (LEP) in the emergency department setting, including increased length of stay, diagnostic error rates, readmission rates, and dissatisfaction. Our emergency department had no standard processes for LEP patient identification or interpreter encounter documentation and a higher rate of 48-hour LEP return visits (RV) than English proficient patients. The aim was to eliminate gaps by increasing appropriate interpreter use and documentation (AIUD) for Spanish-speaking LEP (LEP-SS) patients from 35.7% baseline (10/17-05/18) to 100% by October 2020. METHODS: LEP-SS patient data were reviewed in the electronic medical record to determine the AIUD and RV rates. Using the Model for Improvement and multiple Plan-Do-Study-Act (PDSA) cycles, a multi-disciplinary team encouraged stakeholder engagement and identified improvement opportunities, implemented an electronic tracking board LEP icon (PDSA1), standardized documentation using an LEP Form linked to the icon (PDSA2), and included color changes to the icon for team situational awareness (PDSA3). RESULTS: The mean of LEP-SS patients with AIUD improved from 35.7% to 64.5% without significant changes in balancing measures. During the postintervention period (6/1/2018-10/31/2020), no special cause variation was noted from the baseline 48-hour emergency department RV rates for LEP patients (3.1%) or English proficient patients (2.6%). CONCLUSIONS: While the RV rate was not affected, this project is part of a multi-faceted approach aiming to positively impact this outcome measure. Significant improvements in AIUD were achieved without affecting balancing measures.

A model of the UV skin dose distribution in paediatric whole-body phototherapy.

The radiance equation is applied in this study to model the ultraviolet (UV) radiation dose distribution over the skin in paediatric and adult patients treated in a whole-body phototherapy cabin. This approach extends a previously published model of UV radiation dose based on thermal radiation exchange between surfaces (Colemanet al2020Biomed. Phys. Eng. Express6055023). The new model makes it feasible to predict the distribution of UV irradiance over the head, trunk and legs in patients of varying height. The modelled irradiance distributions to directly lamp-facing skin surfaces agree to within 10% of those measured in simulated clinical paediatric treatments in a modern narrowband UVB treatment cabin. For a 10 year old (of height 1.36 m), for example, the model and the clinical measurements both show a UV radiation dose to the face that is around 25% more than that in an adult (of height 1.8 m). The dose to the crown of the head of a 10 year old is both predicted and measured to be more than double that of an adult. The automated dosimetry system, incorporated within the treatment cabin, is also predicted to overestimate irradiance to the body by between 10% and 25% in patients aged between 10 and 4 years (height 1.36-1.0 m). The value of the model and its implications for paediatric whole-body UV treatment in adult-size whole-body treatment cabins are considered.

Novel experimental setup for megahertz X-ray diffraction in a diamond anvil cell at the High Energy Density (HED) instrument of the European X-ray Free-Electron Laser (EuXFEL).

The high-precision X-ray diffraction setup for work with diamond anvil cells (DACs) in interaction chamber 2 (IC2) of the High Energy Density instrument of the European X-ray Free-Electron Laser is described. This includes beamline optics, sample positioning and detector systems located in the multipurpose vacuum chamber. Concepts for pump-probe X-ray diffraction experiments in the DAC are described and their implementation demonstrated during the First User Community Assisted Commissioning experiment. X-ray heating and diffraction of Bi under pressure, obtained using 20 fs X-ray pulses at 17.8 keV and 2.2 MHz repetition, is illustrated through splitting of diffraction peaks, and interpreted employing finite element modeling of the sample chamber in the DAC.

Atenolol in cats with subclinical hypertrophic cardiomyopathy: a double-blind, placebo-controlled, randomized clinical trial of effect on quality of life, activity, and cardiac biomarkers.

OBJECTIVE: To compare quality of life (QOL) and activity measures between healthy control cats and cats with subclinical hypertrophic cardiomyopathy (HCM), and to evaluate the effect of oral atenolol therapy on QOL, activity, and circulating biomarkers in cats with subclinical HCM. ANIMALS: Thirty-two client-owned cats with subclinical HCM and 27 healthy control cats. METHODS: Owner responses to a QOL questionnaire, circulating cardiac biomarker concentrations, and accelerometer-based activity measures were compared prospectively in cats with and without HCM, and in cats with HCM before and after treatment with oral atenolol (6.25 mg/cat q 12 h) for 6 months. RESULTS: Owner-assessed activity of daily living score was lower in cats with HCM than in cats in controls (p=0.0420). No differences were identified between control cats and cats with HCM for any activity variable. Compared with placebo, treatment with atenolol was associated with a lower baseline-adjusted mean ± SD heart rate (157 ± 30 vs. 195 ± 20 bpm; p=0.0001) and rate-pressure product (22,446 ± 6,237 vs. 26,615 ± 4,623 mmHg/min; p=0.0146). A treatment effect of atenolol on QOL or activity was not demonstrated. CONCLUSIONS: This study failed to identify an effect of subclinical HCM on owner-assessed QOL or activity or a treatment effect of atenolol on these variables at the dosage evaluated. These findings do not support a treatment benefit of atenolol for the goal of symptom reduction in cats with subclinical HCM.

Training with cognitive load improves performance under similar conditions in a real surgical task.

BACKGROUND: Enhancing cognitive load while performing a bimanual surgical task affects performance. Whether repeated training under this condition could benefit performance in an operating room was tested using a virtual reality simulator with cognitive load applied through two-digit math multiplication questions. METHOD: 11 subjects were randomized to Control, VR and VR + CL groups. After a pre-test, VR and VR + CL groups repeated the peg transfer task 150 times over 15 sessions with cognitive load applied only for the last 100 trials. After training, all groups took a post-test and two weeks later the retention test with and without cognitive load and the transfer task on a pig intestine of 150 cm long under cognitive load. RESULTS AND CONCLUSION: Mixed ANOVA analysis showed significant differences between the control and VR and VR + CL groups (p = 0.013, p = 0.009) but no differences between the VR + CL and the VR groups (p = 1.0). GOALS bimanual dexterity score on transfer test show that VR + CL group outperformed both Control and VR groups (p = 0.016, p = 0.03). Training under cognitive load benefitted performance on an actual surgical task under similar conditions.

Outcomes after combined percutaneous balloon valvuloplasty and external beam radiation therapy for the treatment of congenital pulmonic stenosis in four dogs.

Valve restenosis after percutaneous balloon pulmonary valvuloplasty (BPV) for the treatment of congenital pulmonic stenosis (PS) may occur in up to 17% of canine cases. Outcomes in dogs with PS that are treated with repeat BPV after restenosis have not been described. The present report details the clinical courses of four dogs with congenital PS, previously treated with conventional BPV and atenolol (n = 4) or atenolol alone (n = 1), two with anomalous, circumpulmonary coronary artery anatomy, which underwent BPV followed immediately by external beam radiation therapy (BPV + EBRT) to prevent valve restenosis. External beam radiation therapy involved five daily fractions of 3.6 Gray to the pulmonic valve. Echocardiographic and clinical follow-up information for 2-4 years after BPV + EBRT is presented. Three dogs experienced long-term reduction in transpulmonic pressure gradient. In one dog, which was treated with conservative BPV + EBRT as first-line therapy, return of transpulmonic pressure gradient to pretreatment levels was noted by 7 months after BPV + EBRT. Although clinical benefit remains unproven, the addition of EBRT to conventional BPV may be a treatment option for dogs experiencing restenosis after BPV or those in which restenosis is considered likely. Further study to evaluate the efficacy and safety of this approach is needed.

A thermal radiation exchange model of whole-body UV phototherapy.

A novel model of the skin dose in whole-body UV phototherapy treatment cabins is presented. The model is based on an analysis of the thermal radiation exchange between two surfaces, in this case the UV source and the patient. It is shown to allow analytical treatment of the multiple internal reflections in a treatment cabin that account for around 40% of the skin irradiance. The model provides predictions of the absolute irradiance at the skin and shielding factors in seven different UVA and NB-UVB cabins that are within 6% of those measured using a calibrated radiometer and within 12% for all nine cabins. The model predicts reducing skin irradiances with increasingly patient size, a trend demonstrated in clinical measurements. The exact sensitivity to patient size in automated cabin dosimetry systems, however, varies with in-built sensor positioning. The potential to extend the use of the model to investigate improved design of automated dosimetry systems is discussed.

Measurement of Body-Centered Cubic Gold and Melting under Shock Compression.

We combined laser shock compression with in situ x-ray diffraction to probe the crystallographic state of gold (Au) on its principal shock Hugoniot. Au has long been recognized as an important calibration standard in diamond anvil cell experiments due to the stability of its face-centered cubic (fcc) structure to extremely high pressures (P >600 GPa at 300 K). This is in contrast to density functional theory and first principles calculations of the high-pressure phases of Au that predict a variety of fcc-like structures with different stacking arrangements at intermediate pressures. In this Letter, we probe high-pressure and high-temperature conditions on the shock Hugoniot and observe fcc Au at 169 GPa and the first evidence of body-centered cubic (bcc) Au at 223 GPa. Upon further compression, the bcc phase is observed in coexistence with liquid scattering as the Hugoniot crosses the Au melt curve before 322 GPa. The results suggest a triple point on the Au phase diagram that lies very close to the principal shock Hugoniot near ∼220 GPa.

Identification of Phase Transitions and Metastability in Dynamically Compressed Antimony Using Ultrafast X-Ray Diffraction.

Ultrafast x-ray diffraction at the LCLS x-ray free electron laser has been used to resolve the structural behavior of antimony under shock compression to 59 GPa. Antimony is seen to transform to the incommensurate, host-guest phase Sb-II at ∼11 GPa, which forms on nanosecond timescales with ordered guest-atom chains. The high-pressure bcc phase Sb-III is observed above ∼15 GPa, some 8 GPa lower than in static compression studies, and mixed Sb-III/liquid diffraction are obtained between 38 and 59 GPa. An additional phase which does not exist under static compression, Sb-I^{'}, is also observed between 8 and 12 GPa, beyond the normal stability field of Sb-I, and resembles Sb-I with a resolved Peierls distortion. The incommensurate Sb-II high-pressure phase can be recovered metastably on release to ambient pressure, where it is stable for more than 10 ns.

Femtosecond diffraction studies of solid and liquid phase changes in shock-compressed bismuth.

Bismuth has long been a prototypical system for investigating phase transformations and melting at high pressure. Despite decades of experimental study, however, the lattice-level response of Bi to rapid (shock) compression and the relationship between structures occurring dynamically and those observed during slow (static) compression, are still not clearly understood. We have determined the structural response of shock-compressed Bi to 68 GPa using femtosecond X-ray diffraction, thereby revealing the phase transition sequence and equation-of-state in unprecedented detail for the first time. We show that shocked-Bi exhibits a marked departure from equilibrium behavior - the incommensurate Bi-III phase is not observed, but rather a new metastable phase, and the Bi-V phase is formed at significantly lower pressures compared to static compression studies. We also directly measure structural changes in a shocked liquid for the first time. These observations reveal new behaviour in the solid and liquid phases of a shocked material and give important insights into the validity of comparing static and dynamic datasets.

Interprofessional education in dentistry.

A collaborative health workforce is required to respond to the increasing demands on healthcare resources. Various national and international bodies are promoting interprofessional education (IPE) as a method to provide this collaborative health workforce. IPE is therefore becoming increasingly prominent within healthcare training and will be an essential aspect of dental education. A literature search was completed to provide this narrative review which will introduce IPE, discuss the rationale for IPE within dentistry and the challenges faced. Based on current literature, it will provide practical advice on how to implement an effective IPE learning activity within dentistry.

Cigarette smoking and glaucoma in the United States population.

PurposeTo evaluate the association between cigarette smoking and glaucoma in the United States population.Patients and methodsUS civilian, non-institutionalized population from 2005 to 2008 administrations of the National Health and Nutrition Examination Survey that were ≥40 years of age with visual fields and optic disc photographs were included. Diagnosis of glaucoma was based on the Rotterdam criteria. Logistic regression modeling was performed to assess the association between glaucoma and smoking history, while controlling for age, gender, ethnicity, household income, alcohol consumption, diabetes, and hypertension.ResultsIn 3864 participants, 212 (5.5%) had glaucoma (corresponds to a population weighted glaucoma prevalence of 3.7% in a total of 83 570 127 subjects). Population weighted proportion of current smokers was 20.6% and ex-smokers was 28.3%. Participants with glaucoma were older (63.0±11.6 vs 56.1±11.2, P=0.002), likely to be male (57.1% vs 49.2%, P=0.03), to be Black (36.3% vs 20.7%, P<0.001), and to have diabetes (18.9% vs 12.4%, P=0.006) and hypertension (50.5% vs 39.7%, P=0.003). Current smokers had a lower odds of glaucoma compared to non-smokers (OR=0.61, 95% CI=0.41-0.88, P=0.009), and ex-smokers (OR=0.46, 95% CI=0.28-0.76, P=0.002). The effect estimates were similar in adjusted models, but not statistically significant. Among smokers, greater pack/day of smoking history was associated with statistically significantly higher odds of glaucoma (OR=1.70, 95% CI=1.08-2.67, P=0.02).ConclusionsAmong cigarette smokers, heavy smoking defined by greater number of pack of cigarettes smoked per day is associated with higher odds of glaucoma. Health care providers should include this association when counseling patients on their smoking habit.

Preliminary investigation of orally administered benazepril in horses with left-sided valvular regurgitation.

BACKGROUND: Despite the paucity of data available, orally administered angiotensin-converting enzyme (ACE) inhibitors are empirically used in horses with valvular regurgitation. OBJECTIVE: Evaluate the echocardiographic and hormonal changes in response to oral benazepril in horses with left-sided valvular regurgitation. STUDY DESIGN: Prospective, randomised double-blind, placebo-controlled trial. METHODS: Horses with mitral valve (MR) and/or aortic valve regurgitation (AR) received oral benazepril (n = 6) at a dosage of 1 mg/kg q 12 h or a placebo (n = 5) for 28 days. Echocardiography was performed before drug administration and after 28 days of treatment. Plasma renin activity, serum ACE activity, angiotensin II concentration, aldosterone concentration and biochemical variables were measured before drug administration and after 7 and 28 days of treatment. RESULTS: Relative to baseline, horses treated with benazepril had statistically significant reduction in left ventricular internal diameter in systole (mean difference between groups = -0.97 cm; 95% CI = -1.5 to -0.43 cm), aortic sinus diameter (-0.31 cm; -0.54 to -0.07 cm), and percentage of the aortic annulus diameter occupied by the base of the AR jet (-17.05%; -31.17 to -2.93%) compared with horses receiving a placebo. In addition, horses treated with benazepril had a significantly greater increase in cardiac output (11.95 L/min; 1.17-22.73 L/min) and fractional shortening (7.59%; 3.3-11.88%) compared with horses receiving a placebo. Despite profound serum ACE inhibition, renin activity and concentrations of angiotensin II and aldosterone were not significantly different between treatment groups or among time points. MAIN LIMITATIONS: Very small sample size and short treatment period. CONCLUSIONS: Treatment with oral benazepril resulted in statistically significant echocardiographic changes that might indicate reduced cardiac afterload in horses with left-sided valvular regurgitation. Additional studies with a larger sample size will be necessary to determine if administration of benazepril is beneficial in horses with valvular regurgitation. The Summary is available in Spanish - see Supporting Information.

Direct measurement of the mechanism by which magnesium specifically modifies the mechanical properties of DNA.

We examine the effect of physiological cations Na+, K+, Mg2+, and Ca2+ on the mechanical properties of bundles of λ-phage DNA using silicon nanotweezers (SNTs). Integrating SNTs with a microfluidic device allows us to perform titration experiments while measuring the effect in real-time. The results show that only for Mg2+ and in particular, at the intra-nuclear concentration (100 mM), the interaction occurs.