Physical restraint practices in an adult intensive care unit: A prospective observational study.

AIM AND OBJECTIVES: To conduct a diagnostic evaluation of physical restraint practice using the integrated-Promoting Action on Research Implementation in Health Services (i-PARIHS) framework. BACKGROUND: Evidence indicates that physical restraints are associated with adverse physical, emotional and psychological sequelae and do not consistently prevent intensive care unit (ICU) patient-initiated device removal. Nevertheless, physical restraints continue to be used extensively in ICUs both in Canada and internationally. Implementation science frameworks have not been previously used to diagnose, develop and guide the implementation of restraint minimisation interventions. DESIGN: A prospective observational study of restrained patients in a 20-bed, academic ICU in Toronto, Canada. METHODS: Data collection methods included patient observation, electronic medical record review, and verbal check with the point-of-care nurses. Data were collected pertaining to framework domains of unit culture (restraint application/removal), evaluation capacity (documentation) and leadership (rounds discussion). The reporting of this study followed the STROBE guidelines. RESULTS: A total of 102 restrained patients, 67 (66%) male and mean age 58 years (SD 1.92), were observed. All observed devices were wrist restraints. Restraint application and removal time was verified in 83 and 57 of 102 patients respectively. At application, 96.4% were mechanically ventilated and 71% sedated/unarousable. Nurses confirmed 71% were prophylactically restrained; 7.2% received restraint alternatives. Restraint removal occurred after interprofessional team rounds (87%), during daytime (79%) and following extubation (52.6%). Of the 923 discrete patient observation of physical restraint use, 691 (75%) were not documented. Of the 30 daytime interprofessional team rounds reviewed, physical restraint was discussed at 3 (10%). CONCLUSION: In this single-centre study, a culture of prophylactic physical restraint was observed. Future facilitation of restraint minimisation warrants theoretically informed implementation strategies including leadership involvement to advance interprofessional collaboration. RELEVANCE TO CLINICAL PRACTICE: The findings draw attention to the importance of a preliminary diagnostic study of the context prior to designing, and implementing, a physical restraint minimisation intervention.

Surface chemistry of metal oxide nanoparticles: NMR and TGA quantification.

Surface functionalization is widely used to control the behavior of nanomaterials for a range of applications. However, methods to accurately quantify surface functional groups and coatings are not yet routinely applied to nanomaterial characterization. We have employed a combination of quantitative NMR (qNMR) and thermogravimetric analysis (TGA) to address this problem for commercial cerium, nickel, and iron oxide nanoparticles (NPs) that have been modified to add functional coatings with (3-aminopropyl)triethoxysilane (APTES), stearic acid, and polyvinylpyrrolidone (PVP). The qNMR method involves quantification of material that is released from the NPs and quantified in the supernatant after removal of NPs. Removal of aminopropylsilanes was accomplished by basic hydrolysis whereas PVP and stearic acid were removed by ligand exchange using sodium hexametaphosphate and pentadecafluorooctanoic acid, respectively. The method accuracy was confirmed by analysis of NPs with a known content of surface groups. Complementary TGA studies were carried out in both air and argon atmosphere with FT-IR of evolved gases in argon to confirm the identity of the functional groups. TGA measurements for some unfunctionalized samples show mass loss due to unidentified components which makes quantification of functional groups in surface-modified samples less reliable. XPS provides information on the presence of surface contaminants and the level of surface hydroxylation for selected samples. Despite the issues associated with accurate quantification using TGA, the TGA estimates agree reasonably well with the qNMR data for samples with high surface loading. This study highlights the issues in analysis of commercial nanomaterials and is an advance towards the development of generally applicable methods for quantifying surface functional groups.

Interprofessional intensive care unit (ICU) team perspectives on physical restraint practices and minimization strategies in an adult ICU: A qualitative study of contextual influences.

BACKGROUND: Guidelines advocate for minimization of physical restraint (PR) use in intensive care units (ICU). Interprofessional team perspectives on PR practices can inform the design and implementation of successful PR minimization interventions. AIM: To identify ICU staff perspectives of contextual influences on PR practices and minimization strategies. STUDY DESIGN: A qualitative descriptive study in a single ICU in Toronto, Canada. METHODS: One-on-one semi-structured interviews were conducted with 14 ICU staff. A deductive content analysis of interviews was undertaken using the integrated-Promoting Action on Research Implementation in Health Services (i-PARIHS) framework. RESULTS: Five themes were developed: risk-averse culture, leadership, practice monitoring and feedback processes, environmental factors, and facilitation. Participants described a risk-averse culture where prophylactic application of PR for intubated patients was used to prevent unplanned extubation thereby avoiding blame from colleagues. Perceived absence of leadership and interprofessional team involvement situated nurses as the primary decision-maker for restraint application and removal. Insufficient monitoring of restraint practices, lack of access to restraint alternatives, and inability to control environmental contributors to delirium and agitation further increased PR use. Recommendations as to how to minimize restraint use included a nurse facilitator to advance leadership-team collaboration, availability of restraints alternatives, and guidance on situations for applying and removing restraints. CONCLUSIONS: This analysis of contextual influences on PR practices and minimization using the i-PARIHS framework revealed potentially modifiable barriers to successful PR minimization, including a lack of leadership involvement, gaps in practice monitoring, and collaborative decision-making processes. A team approach to changing behaviour and culture should be considered for successful implementation and sustainability of PR minimization. RELEVANCE TO PRACTICE: The establishment of an interprofessional facilitation team that addresses risk-averse culture and promotes collaboration among ICU stakeholders will be crucial to the success of any approach to restraint minimization.

Interlaboratory Comparison on the Quantification of Total and Accessible Amine Groups on Silica Nanoparticles with qNMR and Optical Assays.

Risk assessment of nanomaterials requires not only standardized toxicity studies but also validated methods for nanomaterial surface characterization with known uncertainties. In this context, a first bilateral interlaboratory comparison on surface group quantification of nanomaterials is presented that assesses different reporter-free and labeling methods for the quantification of the total and accessible number of amine functionalities on commercially available silica nanoparticles that are widely used in the life sciences. The overall goal of this comparison is the identification of optimum methods as well as achievable measurement uncertainties and the comparability of the results across laboratories. We also examined the robustness and ease of implementation of the applied analytical methods and discussed method-inherent limitations. In summary, this comparison presents a first step toward the eventually required standardization of methods for surface group quantification.

Particle Size Distributions for Cellulose Nanocrystals Measured by Transmission Electron Microscopy: An Interlaboratory Comparison.

Particle size is a key parameter that must be measured to ensure reproducible production of cellulose nanocrystals (CNCs) and to achieve reliable performance metrics for specific CNC applications. Nevertheless, size measurements for CNCs are challenging due to their broad size distribution, irregular rod-shaped particles, and propensity to aggregate and agglomerate. We report an interlaboratory comparison (ILC) that tests transmission electron microscopy (TEM) protocols for image acquisition and analysis. Samples of CNCs were prepared on TEM grids in a single laboratory, and detailed data acquisition and analysis protocols were provided to participants. CNCs were imaged and the size of individual particles was analyzed in 10 participating laboratories that represent a cross section of academic, industrial, and government laboratories with varying levels of experience with imaging CNCs. The data for each laboratory were fit to a skew normal distribution that accommodates the variability in central location and distribution width and asymmetries for the various datasets. Consensus values were obtained by modeling the variation between laboratories using a skew normal distribution. This approach gave consensus distributions with values for mean, standard deviation, and shape factor of 95.8, 38.2, and 6.3 nm for length and 7.7, 2.2, and 2.9 nm for width, respectively. Comparison of the degree of overlap between distributions for individual laboratories indicates that differences in imaging resolution contribute to the variation in measured widths. We conclude that the selection of individual CNCs for analysis and the variability in CNC agglomeration and staining are the main factors that lead to variations in measured length and width between laboratories.

Acellular oxidative potential assay for screening of amorphous silica nanoparticles.

Silica nanoparticles (SiNPs) are used in a wide range of consumer products, engineering and medical applications, with likelihood of human exposure and potential health concerns. It is essential to generate toxicity information on SiNP forms and associated physicochemical determinants to conduct risk assessment on these new materials. To address this knowledge gap, we screened a panel of custom synthesized, well-characterized amorphous SiNPs pristine and surface-modified (-C3-COOH, -C11-COOH, -NH2, -PEG) of 5 different sizes: (15, 30, 50, 75, 100 nm) for their oxidative potential using an acellular assay. The assay is based on oxidation of dithiothreitol (DTT) by reactive oxygen species and can serve as a surrogate test for oxidative stress. These materials were characterized for size distribution, aggregation, crystallinity, surface area, surface modification, surface charge and metal content. Tests for association between oxidative potential of SiNPs and their physicochemical properties were carried out using analysis of variance and correlation analyses. These test results suggest that the size of amorphous SiNPs influenced their oxidative potential irrespective of the surface modification, with 15 nm exhibiting relatively higher oxidative potential compared to the other sizes. Furthermore, SiNP surface area, surface modification and agglomeration in solution also appeared to affect oxidative potential of these SiNPs. These findings indicate that physicochemical properties are critical in influencing the oxidative behaviour of amorphous SiNPs, with potential to trigger cellular oxidative stress and thus toxicity, when exposed. This information advances our understanding of potential toxicities of these amorphous SiNPs and supports risk assessment efforts and the design of safer forms of silica nanomaterials.

High response and re-infection rates among people who inject drugs treated for hepatitis C in a community needle and syringe programme.

To achieve WHO hepatitis C virus (HCV) elimination targets by 2030, mathematical models suggest there needs to be significant scale-up of treatment among people who inject drugs (PWID). We tested whether people who actively inject drugs can be recruited and treated successfully through a community needle and syringe programme (NSP), and assessed rates of re-infection. 105 HCV RNA positive participants were enrolled prospectively. Participants were recruited from the largest NSP in Dundee over 42 months. 94/105 individuals commenced treatment. Genotype 1 (G1) individuals (n = 37) were treated with peg-interferon+ribavirin+Simepravir/Telaprevir. Genotype 2/3 (G2/3) (n = 57) received peg-interferon+ribavirin. Weekly study visits took place within the NSP. Mean age of participants was 34.0 years (SD 6.9), 71.3% (61/94) were male. One in five (20/94) participants were homeless. 68.1% (64/94) were on OST (opiate substitution therapy) at enrolment; participants injected median 6.5 times/wk. In terms of clinical outcomes, >80% treatment adherence was 71.3% (67/94). There was no difference in SVR-12 rates by genotype: 81.0% (30/37) for G1 and 82.5% (47/55) for G2/3. At 18 months post-treatment, 15/77 participants were reinfected, followed up over 69.8 person-years, yielding a re-infection rate of 21.5/100 person-years (95% CI 13.00-35.65). This trial demonstrates that HCV treatment can be delivered successfully to the target population of treatment as prevention strategies. We report higher rates of re-infection than existing estimates among PWID. Scale-up of HCV treatment should be pursued alongside a comprehensive programme of harm reduction interventions to help minimize re-infection and reduce HCV transmission.

Quantification of surface functional groups on silica nanoparticles: comparison of thermogravimetric analysis and quantitative NMR.

Thermogravimetric analysis (TGA) coupled with evolved gas analysis-FT-IR has been examined as a potential method to study the functional group content for surface modified silica nanoparticles. A comparison with a quantitative solution NMR method based on analysis of groups released after dissolution of the silica matrix is used to provide benchmark data for comparison and to assess the utility and limitations of TGA. This study focused primarily on commercially available silicas and tested whether it was possible to use a correction based on bare silica to account for the significant mass loss that occurs due to condensation of surface hydroxyl groups and loss of matrix-entrapped components at temperatures above ∼200 °C. Although this approach has been used successfully in the literature for in-house prepared samples, it was problematic for commercial silicas prepared by the Stöber method. For these materials the agreement between estimates from qNMR and TGA mass loss was poor in many cases. However much better agreement was observed for samples for which the mass loss above 200 °C is relatively low, such as non-porous silica, or samples for which the mass fraction of functional group is large (e.g., high molecule weight groups or multilayers). FT-IR was useful in identifying the likely structure of the components lost from the surface at various temperatures and in some cases provided evidence of contaminants in the sample. Nevertheless, in other cases correlation of thermograms and FT-IR with NMR data was necessary, particularly for samples where multi-step modification of the silica surface results in incomplete functionalization that gives a mixture of products. Overall the results indicate that TGA provides reliable results for silicas of low porosity or those for which the functional group accounts for a significant fraction of the total sample mass. It is also suitable as a supplementary or screening technique to indicate the presence of coatings or covalent surface modification, prior to applying other techniques or for routine analyses where sensitivity is not critical.

Characterization of Size and Aggregation for Cellulose Nanocrystal Dispersions Separated by Asymmetrical-Flow Field-Flow Fractionation.

Cellulose nanocrystals (CNCs) derived from various types of cellulose biomass have significant potential for applications that take advantage of their availability from renewable natural resources and their high mechanical strength, biocompatibility and ease of modification. However, their high polydispersity and irregular rod-like shape present challenges for the quantitative dimensional determinations that are required for quality control of CNC production processes. Here we have fractionated a CNC certified reference material using a previously reported asymmetrical-flow field-flow fractionation (AF4) method and characterized selected fractions by atomic force microscopy (AFM) and transmission electron microscopy. This work was aimed at addressing discrepancies in length between fractionated and unfractionated CNC and obtaining less polydisperse samples with fewer aggregates to facilitate microscopy dimensional measurements. The results demonstrate that early fractions obtained from an analytical scale AF4 separation contain predominantly individual CNCs. The number of laterally aggregated "dimers" and clusters containing 3 or more particles increases with increasing fraction number. Size analysis of individual particles by AFM for the early fractions demonstrates that the measured CNC length increases with increasing fraction number, in good agreement with the rod length calculated from the AF4 multi-angle light scattering data. The ability to minimize aggregation and polydispersity for CNC samples has important implications for correlating data from different sizing methods.

Quantification and Stability Determination of Surface Amine Groups on Silica Nanoparticles Using Solution NMR.

Surface chemistry is a critical factor for determining the behavior of a nanomaterial after incorporation in composites, devices, and biomedical products, and is also important for nanotoxicology studies. We have developed an optimized protocol for dissolution of aminated silicas and determination of functional-group contents by quantitative 1H NMR (qNMR) analysis of the released amines. A number of variables were optimized for the dissolution protocol, including the base concentration, mass of silica, time, temperature, and method of sample agitation, in order to achieve adequate NMR signals for quantification. The protocol was tested using nanoparticles from a single commercial supplier with sizes ranging from 20 to 120 nm that were functionalized with 3-aminopropyl groups. Interestingly the batch-to-batch variability for some sizes of these aminated silicas was as high as 50%. Amine contents measured by a ninhydrin colorimetric assay were typically ∼20% lower than those measured by qNMR, consistent with measurement of only ninhydrin-reagent accessible amines. The dissolution-qNMR protocol was compatible with aminated silicas from other commercial suppliers, and in these cases, an even larger variability in surface coverage was observed. Silica nanoparticles with longer-chain amines and variable amine loadings were synthesized to demonstrate the ability to quantify amines with more complex structures and to assess the limit of quantification for the dissolution-qNMR method. Finally, the stability of the aminated nanoparticles was examined. Loss of 3-aminopropyl groups occurred in water at room temperature and was significantly more rapid at higher temperatures. Amine loss increased with increasing surface coverage and was slower for long-chain amines, consistent with studies of amine stability on planar silica. Overall, this work highlights the importance of developing methods for quantifying surface functionalization, particularly given the variability in surface coverage for commercial samples, and for ensuring that the amine group is stable under its usage conditions.

Interventions to prevent hypothermia at birth in preterm and/or low birth weight infants.

BACKGROUND: Newborn admission temperature is a strong predictor of outcomes across all gestations. Hypothermia immediately after birth remains a worldwide issue and, if prolonged, is associated with harm. Keeping preterm infants warm is difficult even when recommended routine thermal care guidelines are followed in the delivery room. OBJECTIVES: To assess the efficacy and safety of interventions designed for prevention of hypothermia in preterm and/or low birth weight infants applied within 10 minutes after birth in the delivery room, compared with routine thermal care or any other single/combination of intervention(s) also designed for prevention of hypothermia in preterm and/or low birth weight infants applied within 10 minutes after birth in the delivery room. SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5), MEDLINE via PubMed (1966 to 30 June 2016), Embase (1980 to 30 June 2016), and CINAHL (1982 to 30 June 2016). We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. SELECTION CRITERIA: Trials using randomised or quasi-randomised allocations to test interventions designed to prevent hypothermia (apart from 'routine' thermal care) applied within 10 minutes after birth in the delivery room for infants at < 37 weeks' gestation and/or birth weight ≤ 2500 grams. DATA COLLECTION AND ANALYSIS: We used Cochrane Neonatal methods when performing data collection and analysis. MAIN RESULTS: Twenty-five studies across 15 comparison groups met the inclusion criteria, categorised as: barriers to heat loss (18 studies); external heat sources (three studies); and combinations of interventions (four studies).Barriers to heat loss Plastic wrap or bag versus routine carePlastic wraps improved core body temperature on admission to the neonatal intensive care unit (NICU) or up to two hours after birth (mean difference (MD) 0.58°C, 95% confidence interval (CI) 0.50 to 0.66; 13 studies; 1633 infants), and fewer infants had hypothermia on admission to the NICU or up to two hours after birth (typical risk ratio (RR) 0.67, 95% CI 0.62 to 0.72; typical risk reduction (RD) -0.25, 95% CI -0.29 to -0.20; number needed to treat for an additional beneficial outcome (NNTB) 4, 95% CI 4 to 5; 10 studies; 1417 infants). Risk of hyperthermia on admission to the NICU or up to two hours after birth was increased in infants in the wrapped group (typical RR 3.91, 95% CI 2.05 to 7.44; typical RD 0.04, 95% CI 0.02 to 0.06; number needed to treat for an additional harmful outcome (NNTH) 25, 95% CI 17 to 50; 12 studies; 1523 infants), but overall, fewer infants receiving plastic wrap were outside the normothermic range (typical RR 0.75, 95% CI 0.69 to 0.81; typical RD -0.20, 95% CI -0.26 to -0.15; NNTH 5, 95% CI 4 to 7; five studies; 1048 infants).Evidence was insufficient to suggest that plastic wraps or bags significantly reduce risk of death during hospital stay or other major morbidities, with the exception of reducing risk of pulmonary haemorrhage.Evidence of practices regarding permutations on this general approach is still emerging and has been based on the findings of only one or two small studies.External heat sourcesEvidence is emerging on the efficacy of external heat sources, including skin-to-skin care (SSC) versus routine care (one study; 31 infants) and thermal mattress versus routine care (two studies; 126 infants).SSC was shown to be effective in reducing risk of hypothermia when compared with conventional incubator care for infants with birth weight ≥ 1200 and ≤ 2199 grams (RR 0.09, 95% CI 0.01 to 0.64; RD -0.56, 95% CI -0.84 to -0.27; NNTB 2, 95% CI 1 to 4). Thermal (transwarmer) mattress significantly kept infants ≤ 1500 grams warmer (MD 0.65°C, 95% CI 0.36 to 0.94) and reduced the incidence of hypothermia on admission to the NICU, with no significant difference in hyperthermia risk.Combinations of interventionsTwo studies (77 infants) compared thermal mattresses versus plastic wraps or bags for infants at ≤ 28 weeks' gestation. Investigators reported no significant differences in core body temperature nor in the incidence of hypothermia, hyperthermia, or core body temperature outside the normothermic range on admission to the NICU.Two additional studies (119 infants) compared plastic bags and thermal mattresses versus plastic bags alone for infants at < 31 weeks' gestation. Meta-analysis of these two studies showed improvement in core body temperature on admission to the NICU or up to two hours after birth, but an increase in hyperthermia. Data show no significant difference in the risk of having a core body temperature outside the normothermic range on admission to the NICU nor in the risk of other reported morbidities. AUTHORS' CONCLUSIONS: Evidence of moderate quality shows that use of plastic wraps or bags compared with routine care led to higher temperatures on admission to NICUs with less hypothermia, particularly for extremely preterm infants. Thermal mattresses and SSC also reduced hypothermia risk when compared with routine care, but findings are based on two or fewer small studies. Caution must be taken to avoid iatrogenic hyperthermia, particularly when multiple interventions are used simultaneously. Limited evidence suggests benefit and no evidence of harm for most short-term morbidity outcomes known to be associated with hypothermia, including major brain injury, bronchopulmonary dysplasia, retinopathy of prematurity, necrotising enterocolitis, and nosocomial infection. Many observational studies have shown increased mortality among preterm hypothermic infants compared with those who maintain normothermia, yet evidence is insufficient to suggest that these interventions reduce risk of in-hospital mortality across all comparison groups. Hypothermia may be a marker for illness and poorer outcomes by association rather than by causality. Limitations of this review include small numbers of identified studies; small sample sizes; and variations in methods and definitions used for hypothermia, hyperthermia, normothermia, routine care, and morbidity, along with lack of power to detect effects on morbidity and mortality across most comparison groups. Future studies should: be adequately powered to detect rarer outcomes; apply standardised morbidity definitions; focus on longer-term outcomes, particularly neurodevelopmental outcomes.

Comparison of revision risks and complication rates between total HIP replacement and HIP resurfacing within the similar age group.

BACKGROUND AND PURPOSE: Currently it is not clear whether age is a factor affecting revisions in total hip replacement (THR) and hip resurfacing (HR). This study aimed to investigate which of THR or HR has a higher risk in terms of revision and complication within similar age groups. METHODS: A systemic review was performed for published literature research databases and local data and compared the two procedures under the condition that both groups of patients were age matched. Meta-analysis techniques were used to analyse revision and complication rates. Twenty-seven literature studies were included along with local audit data. In total, 2520 HR procedures were compared with age-matched 2526 of THR procedures. MAIN FINDINGS: It was found that revision risk of HR is significantly higher than THR (risk ratio 1.65, 95% CI 1.28-2.31, p < 0.0001), highlighting that HR has a slightly higher chance of reoperation when compared to THR within the similar age group population. In terms of complications, HR was found to have an advantage over THR (risk ratio 0.84, 95% CI 0.73-0.96, p < 0.01). CONCLUSION: THR had a lower revision risk but a slightly higher complication risk than HR under the condition that the two surgical procedures were applied to similar age groups of patients. In other words, age has not played an important role in revision and complication. Survivorship cannot be measured as follow-up periods were different in the studies used.

Cemented total hip replacement in patients under 55 years.

Background and purpose - About 86,000 total hip replacements (THR) have been registered in patients under 55 years in the National Joint Registry of England and Wales (NJR). The use of uncemented implants has increased, despite their outcomes not having been proven to be significantly better than cemented implants in this registry. We determined the implant survivorship and functional outcomes of cemented THR in patients under 55 years at a minimum follow-up of 22 years. Patients and methods - 104 hips in 100 patients were included in this prospective study. Functional outcome was assessed using the Harris Hip Score and radiographs were assessed for implant failure and "at risk" of failure. Kaplan-Meier survivorship analysis was performed. Results - 89% of hips showed good to excellent results at final follow-up with a mean Harris Hip Score of 88 at a mean follow-up of 25 years. Revision was performed in 3/104 hips. 14 acetabular components and 4 femoral components were "at risk" of failure. The survivorship at minimum 22 years with revision for any reason as the end-point was 97% (95% CI 95-98). Interpretation - Cemented hip replacements perform well in young patients with good long-term functional and radiographic outcomes.

An exploratory study of the effect of labor pain management on postpartum depression among Chinese women.

OBJECTIVES: The purpose of this study was to investigate the effects of pain relief during labor on the occurrence of potential postpartum depression in early postpartum among Chinese women. MATERIAL AND METHODS: A quasi-experimental study used, with a convenience sample of 565 women who delivered at the Women's Hospital, School of Medicine. Three types of pain relief were administered based on the women's preference (doula, n = 301; transcutaneous electrical nerve stimulation, n = 51; epidural analgesia, n = 213). Pain scores of participants were assessed using a 10-point visual analog scale during labor. The Edinburgh Postnatal Depression Scale was administered in person and by phone at three days and two to four weeks after delivery, respectively. All data were analyzed using SPSS 20.0. RESULTS: Visual analog scale pain scores in the epidural analgesia group decreased significantly during labor compared to those of the other two groups. The occurrence of potential postpartum depression at three days was 6.6% in the epidural analgesia group, 1.3% in the doula group, and 2% in the transcutaneous electrical nerve stimulation group (P = 0.04). Furthermore, potential postpartum depression occurred at two to four weeks after childbirth in 16% (34/213) of the participants in the epidural analgesia group, 7.3% (22/301) of those who received doula support, and in 7.8% (4/51) of those in the transcutaneous electrical nerve stimulation group (P = 0.006). CONCLUSIONS: The results indicated that epidural analgesia was an effective pain relief method during labor. However, it did not reduce the occurrence of potential postpartum depression and was associated with higher postnatal depression scores.

Interaction of saponin 1688 with phase separated lipid bilayers.

Saponins are a diverse family of naturally occurring plant triterpene or steroid glycosides that have a wide range of biological activities. They have been shown to permeabilize membranes and in some cases membrane disruption has been hypothesized to involve saponin/cholesterol complexes. We have examined the interaction of steroidal saponin 1688-1 with lipid membranes that contain cholesterol and have a mixture of liquid-ordered (Lo) and liquid-disordered (Ld) phases as a model for lipid rafts in cellular membranes. A combination of atomic force microscopy (AFM) and fluorescence was used to probe the effect of saponin on the bilayer. The results demonstrate that saponin forms defects in the membrane and also leads to formation of small aggregates on the membrane surface. Although most of the membrane damage occurs in the liquid-disordered phase, fluorescence results demonstrate that saponin localizes in both ordered and disordered membrane phases, with a modest preference for the disordered regions. Similar effects are observed for both direct incorporation of saponin in the lipid mixture used to make vesicles/bilayers and for incubation of saponin with preformed bilayers. The results suggest that the initial sites of interaction are at the interface between the domains and surrounding disordered phase. The preference for saponin localization in the disordered phase may reflect the ease of penetration of saponin into a less ordered membrane, rather than the actual cholesterol concentration in the membrane. Dye leakage assays indicate that a high concentration of saponin is required for membrane permeabilization consistent with the supported lipid bilayer experiments.

Ensemble and Single Particle Fluorescence Characterization of Dye-Labeled Cellulose Nanocrystals.

Cellulose nanocrystals (CNCs) have been covalently labeled with both fluorescein and rhodamine and studied by a combination of UV-vis absorption spectroscopy and ensemble and single molecule fluorescence spectroscopy. For all samples, the fluorescence anisotropy and lifetimes were consistent with effects expected for covalently bound dye molecules. Low dye loading levels (∼0.1 dye/particle) were estimated for the fluorescein-labeled CNC which coupled with the strong pH dependence make this a less suitable fluorophore for most applications. Rhodamine-labeled CNCs were prepared from both sulfated and carboxylated CNCs and had loading levels that varied from 0.25 to ∼15 dye molecules/CNC. For the sulfated samples, the absorption due to (nonfluorescent) dimeric dye increased with dye loading; in contrast, the carboxylated sample, which had the highest rhodamine content, had a low dimer yield. Single particle fluorescence studies for two of the rhodamine-labeled CNCs demonstrated that individual particles are readily detected by their stepwise blinking/bleaching behavior and by polarization effects. Overall, the results indicate the importance of understanding the effects of loading on dye photophysics to select an optimal dye concentration to maximize sensitivity while minimizing the effect of the dye on the CNC behavior. The results also demonstrate that CNCs with relatively low dye loadings (e.g., ∼1 dye/particle) are readily detectable by fluorescence and should be adequate for use in fluorescence-based biological assays or to probe the distribution of CNCs in composite materials.

Acetabulum-Only Revision Total Hip Arthroplasty Is Associated With Good Functional Outcomes and Survivorship.

BACKGROUND: The coexistence of a stable femoral and a loose acetabular component may pose a clinical dilemma for the surgeon. Our study aims at comparing the intermediate functional outcomes and survivorship of acetabulum-only revision total hip arthroplasty (ArTHA) with an age-matched and gender-matched total revision THA (TrTHA) group. METHODS: We retrospectively reviewed prospectively collected data on the pain, function, and total Harris Hip Scores (HHS) and complication profile for ArTHA and TrTHA cohorts from our regional arthroplasty database. Kaplan-Meier survivorship, with the need for repeat revision surgery as the end point, was used for survival analysis. RESULTS: Among 538 cases, there were fewer acute medical complications in ArTHA and a similar dislocation rate for both cohorts. Preoperative HHS for pain, function, and total were better in the ArTHA cohort, but only the function score reached statistical significance. No significant differences in subsequent years for all aspects of HHS, except the function score was significantly better in the ArTHA cohort at year 1. And 10.0% of ArTHAs and 7.8% of TrTHAs had required rerevision. The 5-year survivorship was 90.3% (95% confidence interval ± 2.1%) for the ArTHA cohort and 92.7% (95% confidence interval ± 1.8%) for the TrTHA cohort (P = .394). The ArTHA with posterior approach (n = 118) group had the lowest dislocation rate and the best trend of functional outcomes. CONCLUSION: ArTHA can provide similar functional outcomes and dislocation rate to TrTHA, with an acceptable rerevision rate. The posterior approach in this study was not associated with a significant dislocation rate.

Numbness Around the Total Knee Arthroplasty Surgical Scar: Prevalence and Effect on Functional Outcome.

BACKGROUND: Numbness around the surgical scar can be a source of discomfort or dissatisfaction in a proportion of patients undergoing total knee arthroplasty (TKA). Literature reports wide variation in its prevalence and the consequence of numbness on the outcome of TKA is not clear. We investigated the prevalence of numbness, along with contributing factors, and assessed its effect on the functional outcome of TKA. METHODS: In total, 258 knees were included in this prospective patient-reported outcome measure case-control study. Demographic details, type and length of incision, pre-operative and 1-year post-operative Knee Society Scores were recorded and compared. RESULTS: The prevalence of numbness at 1 year was 53%, with a female preponderance. Patients older than 70 years were less affected. Discomfort due to numbness was recorded in 8.7% of the patients, 75% of which were female. The length of the incision correlated positively with the presence of numbness. The Knee Society Scores did not correlate with the presence or area of numbness. CONCLUSION: Our findings indicate a high prevalence of numbness after TKA. Nevertheless, numbness does not affect the functional outcome.

Correlating Cellulose Nanocrystal Particle Size and Surface Area.

Cellulose nanocrystals (CNCs) are negatively charged nanorods that present challenges for characterization of particle size distribution and surface area-two of the common parameters for characterizing nanomaterials. CNC size distributions have been measured by two microscopy methods: atomic force microscopy (AFM) and transmission electron microscopy (TEM). The agreement between the two methods is good for length measurements, after taking into consideration tip-convolution effects for AFM. However, TEM widths are almost twice as large as AFM heights-an effect that we hypothesize is due to counting of a larger fraction of laterally associated CNCs in the TEM images. Overall, the difficulty of selecting individual particles for analysis and possible bias due to selection of a specific particle size during sample deposition are the main limitations associated with the microscopy measurements. The microscopy results were compared to Z-average data from dynamic light scattering, which is a useful method for routine analysis and for examining trends in size as a function of sample treatment. Measurements as a function of sonication energy were used to provide information on the presence of aggregates in the sample. Magic-angle-spinning solid-state NMR was employed to estimate the surface area of CNCs based on the ratio of integrated spectral intensities of resonances stemming from C4 sites at the crystallite surfaces and from all C4 sites. Our approach was adapted from the application of solid-state NMR to characterize larger cellulose microfibers and appears to provide a useful estimate that overcomes the limitations of using the BET method for measuring surface areas of highly aggregated nanomaterials. The solid-state NMR results show that the lateral dimension of the CNCs is consistent with that of elementary cellulose crystallites.

Membrane order parameters for interdigitated lipid bilayers measured via polarized total-internal-reflection fluorescence microscopy.

Incorporating ethanol in lipid membranes leads to changes in bilayer structure, including the formation of an interdigitated phase. We have used polarized total-internal-reflection fluorescence microscopy (pTIRFM) to measure the order parameter for Texas Red DHPE incorporated in the ethanol-induced interdigitated phase (LßI) formed from ternary lipid mixtures comprising dioleoylphosphatidylcholine, cholesterol and egg sphingomyelin or dipalmitoylphosphatidylcholine. These lipid mixtures have 3 co-existing phases in the presence of ethanol: liquid-ordered, liquid-disordered and LßI. pTIRFM using Texas Red DHPE shows a reversal in fluorescence contrast between the LßI phase and the surrounding disordered phase with changes in the polarization angle. The contrast reversal is due to changes in the orientation of the dye, and provides a rapid method to identify the LßI phase. The measured order parameters for the LßI phase are consistent with a highly ordered membrane environment, similar to a gel phase. An acyl-chain labeled BODIPY-FL-PC was also tested for pTIRFM studies of ethanol-treated bilayers; however, this probe is less useful since the order parameters of the interdigitated phase are consistent with orientations that are close to random, either due to local membrane disorder or to a mixture of extended and looping conformations in which the fluorophore is localized in the polar headgroup region of the bilayer. In summary, we demonstrate that order parameter measurements via pTIRFM using Texas Red-DHPE can rapidly identify the interdigitated phase in supported bilayers. We anticipate that this technique will aid further research in the effects of alcohols and other additives on membranes.