Improved Performance With the Micro-Hole Zone Intermittent Catheter: A Combined Analysis of 3 Randomized Controlled Studies Comparing the New Catheter Technology With a Conventional Eyelet Catheter.

PURPOSE: To assess the performance of a new urinary intermittent catheter (IC) prototype designed with a micro-hole drainage zone compared to a conventional eyelet catheter (CEC) in terms of flow-stop, bladder emptying, and hematuria. DESIGN: Randomized controlled crossover studies. SUBJECT AND SETTING: The sample comprised 15 male healthy volunteers (HV) and 15 IC users, along with 15 female HV and 15 IC users. The age range was lower for HV participants than for IC users (range: 20-57 years for HV vs 21-82 years for IC users). The study setting was the Department of Urology, located in Rigshospitalet, Copenhagen. METHODS: Number of flow-stop incidents, residual urine volume at first flow-stop (RV1), and dipstick hematuria were measured during and after catheterization by a health care professional (HV) and by self-catheterisation (IC-users). Results from the 3 studies were combined for HV and IC users on RV1 and number of flow-stop incidents but separated on sex. For incidents of hematuria, an effect of underlying condition was assumed, and a combined analysis on sex was performed, separating HV and IC users. RESULTS: When compared to the micro-hole drainage zone design, catheterizations with CEC resulted in a significantly higher mean RV1 (mean difference: 49 mL in males and 32 mL in females, both P < .001) and average number of flow-stop incidents (8 and 21 times more frequent for males and females, respectively, both P < .001). The likelihood for hematuria was 5.84 higher with CEC than with micro-hole drainage hole design, P = .053, during normal micturition in HV postcatheterization. No serious adverse events were reported. CONCLUSION: The micro-hole drainage zone catheter provides IC users fewer premature flow-stops. This design feature reduces modifiable urinary tract infection risk factors, such as residual urine and micro-trauma; additional research is needed to determine its effects on bladder health.

New Intermittent Urinary Micro-Hole Zone Catheter Shows Enhanced Performance in Emptying the Bladder: A Randomised, Controlled Crossover Study.

Urinary tract infections (UTIs) are common and troublesome complications of clean intermittent catheterisation (CIC) in individuals suffering from incomplete bladder emptying, which may exacerbate the underlying disease and lead to hospitalisation. Aside from the design of the intermittent catheter and its handling, a recent review highlighted residual urine as one of several UTI risk factors. A new urinary intermittent catheter with multiple micro-holes has been developed for improved bladder emptying. In a controlled crossover study, adult male CIC users were randomised for a health care professional-led catheterisation with the new micro-hole zone catheter (MHZC) and a conventional eyelet catheter (CEC) in two individual test visits to compare the number of flow-stops and the residual urine at the first flow-stop as co-primary endpoints. In 42 male CIC users, the MHZC resulted in significantly fewer flow-stop episodes compared to the CEC (mean 0.17, 95% CI [0.06, 0.45] vs. mean 1.09, 95% CI [0.75, 1.6], respectively; p < 0.001) and significantly less residual urine at the first flow-stop (mean 5.10 mL, SE [1.14] vs. mean 39.40 mL, SE [9.65], respectively; p < 0.001). No adverse events were observed in this study. The results confirm the enhanced performance of the MHZC compared to a CEC, ensuring an uninterrupted free urine flow with no need to reposition the catheter until the bladder is thoroughly empty.

Platelet function assessed by ROTEM®platelet in patients receiving antiplatelet therapy during cardiac and vascular surgery.

Patients undergoing coronary artery bypass graft (CABG) surgery or carotid endarterectomy (CEA) continue antiplatelet therapy perioperatively, which may increase bleeding risk. We aimed to investigate whether Rotational thromboelastometry (ROTEM®) platelet, a newly marketed platelet function analysis, would detect antiplatelet therapy in CABG and CEA patients; whether detection of reduced platelet function was associated with increased bleeding; and whether ex vivo desmopressin increased platelet function. We included 20 CABG patients continuing aspirin and 20 CEA patients continuing clopidogrel (n = 1) or clopidogrel and aspirin (n = 19). Platelet function was analyzed with ROTEM®platelet and light transmission aggregometry (LTA). According to the lower reference limit, ROTEM®platelet managed to detect aspirin, but clopidogrel detection was inadequate compared to LTA. Using a previously published cut-off for bleeding risk, 6 (30%) patients receiving aspirin and 4 (21%) patients receiving both clopidogrel and aspirin demonstrated platelet function below this cut-off. One of the four CEA patients below the cut-off died from intracerebral hemorrhage postoperatively. CABG patients below (n = 6) and above (n = 14) the cut-off did not differ in chest tube output (median [range]: 373 ml [250-900] vs. 368 ml [195-820]). Ex vivo addition of desmopressin did not increase platelet function. In conclusion, ROTEM®platelet does reveal aspirin treatment whereas clopidogrel treatment is most often overlooked. Due to low bleeding in the study population, it was not possible to conclude on the association with bleeding risk.

Rapid Prototyping of Miniaturized Powder Mixing Geometries.

Continuous manufacturing is an important element of future manufacturing solutions enabling for both high product quality and streamlined development process. The increasing possibilities with computer simulations allow for innovating novel mixing principles applicable for continuous manufacturing. However, these innovative ideas based on simulations need experimental validation. The use of rapid prototyping based on additive manufacturing opens a possibility to evaluate these ideas at a low cost. In this study, a novel powder mixing geometry was prototyped using additive manufacturing and further, interfaced with an in-line near-IR spectrometer allowing for investigating the residence time distribution (RTD) in this geometry.

Determination of Residence Time Distribution in a Continuous Powder Mixing Process With Supervised and Unsupervised Modeling of In-line Near Infrared (NIR) Spectroscopic Data.

Successful implementation of continuous manufacturing processes requires robust methods to assess and control product quality in a real-time mode. In this study, the residence time distribution of a continuous powder mixing process was investigated via pulse tracer experiments using near infrared spectroscopy for tracer detection in an in-line mode. The residence time distribution was modeled by applying the continuous stirred tank reactor in series model for achieving the tracer (paracetamol) concentration profiles. Partial least squares discriminant analysis and principal component analysis of the near infrared spectroscopy data were applied to investigate both supervised and unsupervised chemometric modeling approaches. Additionally, the mean residence time for three powder systems was measured with different process settings. It was found that a significant change in the mean residence time occurred when comparing powder systems with different flowability and mixing process settings. This study also confirmed that the partial least squares discriminant analysis applied as a supervised chemometric model enabled an efficient and fast estimate of the mean residence time based on pulse tracer experiments.

Near infrared analysis of pharmaceutical powders with empirical target distribution optimization (ETDO).

Near infrared (NIR) spectroscopy is a well-established method for analysis of pharmaceutical products, and especially useful for process monitoring and control of continuous production due to high sample throughput. In this work, a previously established method called empirical target distribution optimization (ETDO) wherein reference sample values using information from model prediction of the calibration data was used as a tool to improve the performance of NIR partial least squares (PLS) models. Model performance was assessed using root mean square error (R2), bias and accuracy in prediction of test samples. A target value selection threshold was tested to assess the ETDO procedure for NIR analysis of powder samples. The amount of specific variation captured by the model was examined and compared for models calibrated with and without ETDO. The results reported in this work suggests that PLS models optimized with ETDO of reference values can provide more specific PLS models for NIR analysis for complex powder mixtures. In addition, the model optimization method could also be applied as a tool to verify the necessary amount of PLS components to produce robust models. The ETDO method presented in this work is an approach that could be applied in the development of continuous blending or tableting processes where robust in-line quantitative analysis of powder samples is needed.

Evaluation of ring shear testing as a characterization method for powder flow in small-scale powder processing equipment.

Powder flow in small-scale equipment is challenging to predict. To meet this need, the impact of consolidation during powder flow characterization, the level of consolidation existing during discharge of powders from a tablet press hopper and the uncertainty of shear and wall friction measurements at small consolidation stresses were investigated. For this purpose, three grades of microcrystalline cellulose were used. Results showed that powder flow properties depend strongly on the consolidation during testing. The consolidation during discharge in terms of the major principal stress and wall normal stress were approximately 200 Pa and 114 Pa, respectively, in the critical transition from the converging to the lower vertical section of the hopper. The lower limit of consolidation for the shear and wall friction test was approximately 500 Pa and 200 Pa, respectively. At this consolidation level, the wall and shear stress resolution influences the precision of the measured powder flow properties. This study highlights the need for an improved experimental setup which would be capable of measuring the flow properties of powders under very small consolidation stresses with a high shear stress resolution. This will allow the accuracy, precision and applicability of the shear test to be improved for pharmaceutical applications.

Myogenic, matrix, and growth factor mRNA expression in human skeletal muscle: effect of contraction intensity and feeding.

INTRODUCTION: We examined short-term (3-hour) and long-term (12-week) training effects after heavy load [HL; 70% 1RM] and light load (LL; 16% 1RM) exercise. METHODS: mRNA expression of genes involved in skeletal muscle remodeling were analyzed and muscle activity (EMG measurements) was measured. RESULTS: Relative muscle activity differed between HL and LL resistance exercise, whereas median power frequency was even, suggesting an equal muscle-fiber-type recruitment distribution. mRNA expression of Myf6, myogenin, and p21 was mostly increased, and myostatin was mostly depressed by HL resistance exercise. No major differences were seen in atrophy-related genes between HL and LL resistance exercise. No changes were seen over 12-week training for any of the targets. CONCLUSIONS: Resistance exercise at LL and HL elevated the expression of genes involved in skeletal muscle hypertrophy, although the greatest response was from HL. However, no long-term effect from either LL or HL resistance exercise was seen on basal levels of the mRNA targets.

Apical myocardial stunning in a large size porcine model assessed by strain and strain rate echocardiography.

BACKGROUND: Warm ischemia and subsequent reperfusion of the heart can induce a temporary dysfunction known as myocardial stunning. The aim of this study was to investigate the ability of tissue Doppler imaging (TDI) to quantify longitudinal myocardial stunning close to the apex, and perform a comparison with sonomicrometry using a well-established large size porcine model. METHODS: In anesthetized pigs, postischemic myocardial stunning was induced by occluding LAD for 15 min followed by 90 min reperfusion (n = 7). Long-axis strain and strain rate was quantified by both TDI and sonomicrometry. RESULTS: During reperfusion, peak systolic strain measured by TDI decreased from -11.2% (+/-3.0) at baseline to -4.9% (+/-3.6), -3.4% (+/-2.9), and -4.3% (+/-5.0) at 30, 60, and 90 min, respectively (all P < 0.007). Postsystolic strain increased from -1.3% (+/-1.6) at baseline to -6.4% (+/-4.4), -4.8% (+/-4.0), and -5.2% (+/-2.7) by TDI in the reperfusion phase (all P < 0.048 except at 60 min of reperfusion (P = 0.081)). Postsystolic index increased from 0.10 (+/-0.13) at baseline to 0.56 (+/-0.24), 0.54 (+/-0.30), and 0.64 (+/-0.37) subsequently (all P < 0.012). [Correction added after online publication 30-May-2007: In the preceding sentence, the phrase 'Postsystolic index decreased from 0.10 (+/-0.13)' was changed to 'Postsystolic index increased from 0.10 (+/-0.13).'] Difference-mean and line of identity plots did not disclose any systematic error, but revealed substantial variation, indicating a mismatch between TDI and sonomicrometry. CONCLUSIONS: It is feasible to quantify postischemic myocardial stunning by TDI in a large size porcine model using longitudinal postsystolic shortening, and postsystolic index as indicators. TDI and sonomicrometry data reach the same end point, but the two techniques are not interchangeable when investigating myocardial stunning close to apex in reference to longitudinal strain and strain rate.

Transesophageal tissue Doppler echocardiography for evaluation of myocardial function during aortic valve replacement.

OBJECTIVE: Tissue Doppler imaging is an evolving ultrasound technology that, compared with traditional echocardiography, promises reduced subjectivity in the assessment of myocardial performance and contributes new information on myocardial function. The aim of this study was to evaluate the feasibility of transesophageal tissue Doppler imaging in the setting of aortic valve replacement. DESIGN: Feasibility study. SETTING: Aarhus University Hospital, Denmark. PARTICIPANTS: Twelve patients with isolated aortic valve stenosis or combined ischemic cardiomyopathy and aortic valve stenosis scheduled for elective aortic valve replacement were included. INTERVENTION: Transgastric short-axis recordings of the left ventricular anterior wall were performed using Vivid-7 technology (GE Healthcare, Horten, Norway) with activated tissue Doppler imaging before sternotomy, at intervals during progressive withdrawal of cardiopulmonary bypass, and within 1 hour after transfer to the postoperative care unit. Data were postprocessed for assessment of systolic radial function with the tissue Doppler modalities, tissue velocity, end-systolic strain rate, and strain by using dedicated software. RESULTS: Accurate tissue Doppler data were obtained for all patients at baseline and postoperatively. During the gradual loading of the left ventricle, velocity measurements were all obtained accurately, whereas 8% to 25 % of strain and strain-rate measurements were considered unreliable. Immediately after cardioplegia, 33% to 58% of measurements were unreliable. CONCLUSIONS: Transesophageal tissue Doppler is feasible in the intraoperative setting, although unreliable data acquisition occurs during cardiopulmonary bypass. Tissue Doppler is a promising quantitative tool for monitoring of myocardial function within minutes and may also reveal new information on myocardial function in patients undergoing thoracic surgery.

Strut chordal-sparing mitral valve replacement preserves long-term left ventricular shape and function in pigs.

OBJECTIVE: Mitral valve replacement with preservation of the entire subvalvular apparatus entails superior postoperative left ventricular function compared with other techniques. However, this option is often not possible because of valve pathology. We hypothesized that preservation of only 4 mitral valve secondary ("strut") chordae would be functionally and geometrically equivalent to total valve preservation in the long-term setting. In a porcine mitral valve replacement model we investigated the long-term effects of 3 surgical techniques on left ventricular function and geometry: (1) total preservation of the native valve, (2) strut chordal preservation, and (3) total excision of the subvalvular apparatus. METHODS: Forty 60-kg pigs were randomized to 1 of the 3 techniques. Global and regional left ventricular function and dimensions were assessed with cardiovascular magnetic resonance and conductance catheter 90 days after mitral valve replacement. Groups were compared by multivariate analysis of variance. RESULTS: There was no overall difference between groups 1 and 2. Group 3 animals had (1) greater base-apex diastolic and systolic lengths, and smaller short-axis diameters, and (2) lower sphericity indices, and greater base-apex and short-axis fractional shortening than groups 1 and 2. Regional analysis showed slimming and elongation to occur primarily in the basal left ventricular segments. Left ventricular contractility and hemodynamic parameters did not differ between groups. CONCLUSIONS: Strut chordal preservation was equivalent to total valve preservation during mitral valve replacement, whereas total chordal resection caused significant left ventricular slimming with compensatory increases in fractional shortening. Therefore, to preserve left ventricular geometry, special attention must be paid to maintain the valvular-ventricular continuity through the strut chordae during mitral valve replacement. This concept may have important therapeutic implications for chordal-sparing mitral valve replacement.

A long-term porcine model for evaluation of prosthetic heart valves.

BACKGROUND: Animal experimental testing is imperative for preclinical evaluation of prosthetic heart valves and implantation techniques. Because human and pig cardiovascular structures including mitral valves show remarkable anatomical similarity, these animals are good candidates for preclinical testing. Previous attempts to establish such long-term models were hampered by both intra- and postoperative difficulties. Our aim was to overcome these difficulties to develop a porcine model for mitral valve replacement (MVR) and furthermore to investigate the practical feasibility of 3 chordal reconstruction procedures. METHODS: Sixteen 60-kg pigs were allocated to undergo 1 of 3 surgical procedures, (1) preservation of the entire subvalvular apparatus (n = 8), (2) preservation of the secondary chordae only (n = 4), or (3) excision of the native valve and papillary resuspension with sutures (n = 4). St. Jude Medical valves (29 mm) were implanted during extracorporeal circulation and cold cardioplegic arrest. Postoperative anticoagulation was administered by subcutaneous heparin injections. RESULTS: Fourteen animals survived 1 month, thriving and without signs of heart failure. One animal was euthanized due to irreversible bleeding in the tracheal tube, and another animal died on the third postoperative day owing to valve thrombosis. CONCLUSION: A practically feasible long-term porcine model of MVR has been established. Because the pig is superior to other species with respect to anatomical and physiological similarity to humans, we consider this model as an optimal platform for experimental preclinical testing of heart valve prostheses.

[Sarcopenia and strength training. Age-related changes: effect of strength training]. / Sarkopeni og styrketraening. Aldersrelaterede aendringer: effekt af styrketraening.

Sarcopenia signifies the age-related loss of muscle mass and consequently muscle strength. Sarcopenia appears to be caused by both muscular and neural factors. Concurrently with the muscle atrophy, a non-linear loss of muscle strength is observed. The decline accelerates after the age of 60. The ability to produce muscular power is reduced even more than the muscle strength. Strength training increases muscle strength and muscular power in the elderly thus counteracting part of the age-related reduction. Improvements, however, depend on the initial strength in the elderly person. The benefit of strength training is greatest in frail elderly and the oldest old, although elderly in general could benefit from strength training. Considering the growing section of elderly in the population, the focus on sarcopenia and measures to counteract this seems more relevant than ever.