A prospective cohort study exploring the impact of tonsillectomy on feeding difficulties in children.

OBJECTIVES: Paediatric feeding difficulties are common, affecting up to 25% of otherwise healthy children, symptoms include food refusal, gagging, choking, and excessive mealtime duration. These symptoms are commonly described in pre-operative discussions about tonsillectomy. This prospective study explores the impact of tonsillectomy on paediatric feeding difficulties. DESIGN: This prospective cohort study invited caregivers of children undergoing tonsillectomy to complete a PediEAT questionnaire about their children's feeding behaviours, pre and post-operatively. The study was completed in two phases with 9 questions administered in phase 1 and three additional questions added for phase 2. A free text comments box was also provided. Responses were graded from 0 to 5, where 0 is 'never a problem' and 5 is 'always a problem' with eating behaviours. SETTING: The study was conducted at our institution, a tertiary paediatric ENT unit. PARTICIPANTS: Children aged between 6 months - 7 years undergoing tonsillectomy for any indication were invited to participate. MAIN OUTCOME MEASURES: Changes to the Pedi-EAT scores pre and post operatively were the main outcome measure. RESULTS: 102 participants were recruited between January 2020 and January 2022. The mean age of participants was 4.1 years, 87% had a concurrent adenoidectomy. The mean time to completion of post-operative questionnaire was 23 weeks after surgery. 9 of the 12 questions showed a statistically significant improvement in post-operative scores using a paired student t-test (p < 0.05). The most significant improvements related to 'gets tired from eating and is not able to finish' (1.49 pre-op, 0.91 post op, p < 0.01) and 'eats food that needs to be chewed' (1.4 pre-op, 0.72 post-op, p < 0.01). 13% of participants only underwent tonsillectomy and this group also showed a statistically significant improvement in fatigue during eating (p < 0.05). CONCLUSION: Symptoms of fatigue during eating and avoidance of food requiring mastication are most likely to improve following tonsillectomy in children.

Trends in hip fracture care in the Republic of Ireland from 2013 to 2018: results from the Irish Hip Fracture Database.

Hip fractures continue to be one of the most serious and costly injuries suffered by older people globally. This paper describes the development of a national hip fracture audit and summarises the first 6 years of data from the Republic of Ireland. This can help inform care, standards and outcomes of hip fracture patients. INTRODUCTION: Ireland has one of the highest standardised rates of hip fracture in the world behind northern European countries. The Irish Hip Fracture Database (IHFD) was established in 2012 to drive clinical and organisational improvements in quality and effectiveness of hip fracture care. This paper describes the progression of the IHFD between 2013 and 2018 and identifies trends and areas for improvement. METHODS: The IHFD is a clinically led, web-based audit, with data collected through the national Hospital Inpatient Enquiry (HIPE) electronic system, the principal source of information from publicly funded acute hospitals in Ireland. Eligible cases are aged ≥ 60 years with hip fracture as defined by IHFD or with other specified hip fracture excluding periprosthetic fractures. As of 2015, all 16 trauma-receiving hospitals within Ireland submitted data. Demographics and adherence to six national quality standards are described. RESULTS: A total of 17,983 cases were included in the analysis. National coverage has increased from 63% in 2013 to 99% in 2018. Demographic characteristics are unchanged, but higher levels of comorbidity are seen. Internal fixation and hemiarthroplasty are the most common modes of surgical repair with two-thirds of cases receiving spinal rather than general anaesthesia. Increasingly patients are being assessed by a geriatrician (11% in 2013 to 69% in 2018) and receive a bone health assessment (65% in 2013 to 84% in 2018). CONCLUSION: While some hip fracture standards have improved, further improvements are required to compare favourably internationally. Reduction of surgical delay and ensuring early mobilisation post-operatively are immediate priorities for the IHFD.

Does the shoe really fit? Characterising ill-fitting footwear among community-dwelling older adults attending geriatric services: an observational cross-sectional study.

BACKGROUND: Falls in older people are common and can result in loss of confidence, fear of falling, restriction in activity and loss of independence. Causes of falls are multi-factorial. There is a paucity of research assessing the footwear characteristics among older people who are at high risk of falls, internationally and in the Irish setting. The aim of this study was to examine the proportion of older adults attending a geriatric day hospital in Ireland who were wearing incorrectly sized shoes. METHODS: A consecutive sample of 111 older adults aged 60 years and over attending a geriatric day hospital in a large Irish teaching hospital was recruited. Demographic data including age, mobility, medications, co-habitation status, footwear worn at home and falls history were recorded. Shoe size and foot length were measured in millimetres using an internal shoe gauge and SATRA shoe size stick, respectively. Participants' self-reported shoe size was recorded. Footwear was assessed using the Footwear Assessment Form (FAF). A Timed Up and Go (TUG) score was recorded. Functional independence was assessed using the Nottingham Extended Activities of Daily Living (NEADL) Scale. The primary outcome of interest in this study was selected as having footwear within the suggested range (10 to 15 mm) on at least one foot. Participants who met this definition were compared to those with ill-fitting footwear on both feet using Chi-square tests, T-tests or Mann-Whitney U tests. RESULTS: The mean difference between shoe length and foot length was 18.6 mm (SD: 9.6 mm). Overall, 72% of participants were wearing footwear that did not fit correctly on both feet, 90% had shoes with smooth, partly worn or fully worn sole treading and 67% reported wearing slippers at home. Participant age, TUG score and NEADL score were not associated with ill-fitting footwear. CONCLUSIONS: Wearing incorrectly fitting shoes and shoes with unsafe features was common among older adults attending geriatric day services in this study. A large number of participants reported wearing slippers at home.

Controlled expedient disposal of excess gun propellant.

The expedient field disposal of excess gun propellants on the ground is an integral part of live-fire training in many countries. However, burning excess propellant in the field will leave significant quantities of energetic residues and heavy metals in the environment. Compounds such as dinitrotoluene and nitroglycerin and metals such as lead will leach into the soil column, eventually migrating to groundwater. Contamination of the environment will lead to high remediation costs and the possible loss of the training facility. After investigating the contamination at several propellant disposal sites, a portable propellant burn pan was developed and tested. The pan was transported to training sites where excess propellant was loaded and burned in a controlled manner. Up to 120 kg of excess single-base propellant charges have been burned during two series of tests at a consumption rate of greater than 99.9%. Less than 0.03% of the energetic material was recovered outside the burn pan. Recovered lead is largely contained within the pan. The turnover rate for burns is 15 min. The residues can be collected following cool-down for proper disposal.

Disinfection by-products in filter backwash water: implications to water quality in recycle designs.

The overall purpose of this research was to investigate disinfection by-product (DBP) concentrations and formation potential in filter backwash water (FBWW) and evaluate at bench-scale the potential impact of untreated FBWW recycle on water quality in conventional drinking water treatment. Two chlorinated organic compound groups of DBPs currently regulated in North America were evaluated, specifically trihalomethanes (THMs) and haloacetic acids (HAAs). FBWW samples were collected from four conventional filtration water treatment plants (WTP) in Nova Scotia, Canada, in three separate sampling and plant audit campaigns. THM and HAA formation potential tests demonstrated that the particulate organic material contained within FBWW is available for reaction with chlorine to form DBPs. The results of the study found higher concentrations of TTHMs and HAA9s in FBWW samples from two of the plants that target a higher free chlorine residual in the wash water used to clean the filters (e.g., clearwell) compared to the other two plants that target a lower clear well free chlorine residual concentration. Bench-scale experiments showed that FBWW storage time and conditions can impact TTHM concentrations in these waste streams, suggesting that optimization opportunities exist to reduce TTHM concentrations in FBWW recycle streams prior to blending with raw water. However, mass balance calculations demonstrated that FBWW recycle practice by blending 10% untreated FBWW with raw water prior to coagulation did not impact DBP concentrations introduced to the rapid mix stage of a plant's treatment train.

Physicochemical characterization of cement kiln dust for potential reuse in acidic wastewater treatment.

Cement kiln dust (CKD) is a fine-grained material produced during the manufacture of cement. Current reuse options are limited and the bulk of CKD not reused in the cement manufacturing process is sent to landfills or stored on-site. Due to the calcium oxide (CaO) content of CKD, it has the potential to be used as a replacement for lime in treating acidic wastewaters such as acid rock drainage (ARD). This paper outlines the results of an examination of the physical and chemical properties of CKD samples collected from six cement plants. The CKD samples were analyzed for major oxides using X-ray diffraction (XRD), available lime, specific surface area, particle size, and morphology using scanning electron microscope (SEM) and compared with a commercial quicklime product. Conductivity, pH, and calcium concentrations of slaked CKD and quicklime solutions were used as indicators of reactivity of the CKD. Slaking of two of the CKD samples with the highest free lime contents (e.g., 34 and 37% free CaO) gave elevated pH values statistically comparable to those of the commercial quicklime sample that was characterized as having 87% available CaO. Acid neutralization trials indicate that even CKD samples with low free lime contents could be effective at neutralizing acidic wastewaters.

Effect of coagulation and flocculation conditions on water quality in an immersed ultrafiltration process.

The removal of natural organic matter under variable coagulation and flocculation pretreatment conditions was evaluated for three surface waters in an immersed ultrafiltration (UF) process. Coagulation with alum, flocculation and UF treatment were conducted in a bench-scale test apparatus designed to simulate pilot- and full-scale water treatment systems. Variable coagulation and flocculation operating conditions were investigated, including coagulant dose, hydraulic retention time (HRT) and mixing intensity (e.g. velocity gradient). Treatment performance was evaluated by measuring specific water quality parameters in the permeate stream, including dissolved organic carbon (DOC), UV254 and true colour. Coagulant dose was found to be the most important variable for treatment performance with regard to permeate water quality, with significantly lower alum dosages required to achieve enhanced coagulation water quality targets than conventional filtration systems. Experiments conducted to evaluate variable flocculation stage HRT and applied velocity gradient demonstrated that traditional set points for these operating variables, applied in conventional filtration systems, may not be required in UF systems. In particular, optimized UF permeate water quality was found with reduced flocculation retention times (e.g. <10 minutes) and mixing intensities (e.g. < 100 s(-1)). The impact of intermittent air scour, or air sparging, operations in the UF process tank during operation was also evaluated. The use of air scour, tested as an intermittent operation at an applied velocity gradient of 50 s(-1) was found to significantly reduce DOC concentrations and UV254 measurements in the UF permeate stream when compared with UF operations without air scour.

Impact of recycling filter backwash water on organic removal in coagulation-sedimentation processes.

The overall purpose of this research was to examine the impacts of filter backwash water (FBWW) and membrane backwash water (MBWW) recycles on water quality in coagulation-sedimentation processes. Specifically, the impact of recycling 5 or 10% by volume of FBWW and MBWW with surface water on the removal of natural organic matter (NOM) was evaluated at bench-scale using a standard jar-test apparatus and measurement of specific water quality parameters including total organic carbon (TOC), dissolved organic carbon (DOC), UV254, turbidity, total aluminum and zeta potential. The results of jar test conducted on a source water with a specific UV absorbance (SUVA) value within the range of 2-4 mg/Lm showed a significantly higher removal of DOC from the raw water that was blended with 5 and 10% by volume of FBWW as compared to control trials where backwash water was not added. Increasing rates of MBWW that did not contain destabilized hydroxide precipitates did not significantly change DOC concentrations in the settled water samples as compared to the control trials. For source waters that are characterized as having low turbidity with medium SUVA values, these results could hold particular significance for plants that have reached treatment ceilings in terms of dissolved NOM removal using conventional coagulation designs.

Biostability and disinfectant by-product formation in drinking water blended with UF-treated filter backwash water.

The overall objective of this study was to investigate the impact of blending membrane-treated water treatment plant (WTP) residuals with plant-filtered water on finished water quality in terms of biostability and disinfectant by-product (DBP) formation. Filter backwash water (FBWW) was treated with a pilot-scale ultrafiltration (UF) membrane to produce permeate that was blended with plant-finished water. The batch studies involved storing samples for a specified time with a disinfectant residual to simulate residence time in the distribution system. Both chlorinated and non-chlorinated FBWW streams were evaluated, and the experimental design incorporated free chlorine, monochloramine, and chlorine dioxide in parallel to a model system that did not receive a disinfectant dose. The results of the study found that blending 10% UF-treated FBWW with plant-filtered water did not have an impact on water biostability as monitored with heterotrophic plate counts (HPCs) or DBP concentrations as monitored by TTHM and HAA5 concentrations. However, the presence of preformed THM and HAA species found in chlorinated FBWW streams may result in higher levels of initial DBP concentrations in blended water matrices, and could have a significant impact on finished water quality in terms of meeting specific DBP guidelines or regulations.

Transjugular liver biopsy is a safe and effective intervention to guide management for patients with a congenital bleeding disorder infected with hepatitis C.

The prevalence of hepatitis C virus (HCV) infection in adult patients with a congenital bleeding disorder (CBD) approaches 95% and is a major cause of morbidity and mortality. Histological examination of the liver remains the cornerstone of management decisions in patients without a CBD. The reluctance to perform liver biopsies in patients with a CBD has been a major limitation in the management of these patients. We are currently the only haemophilia centre in Australasia performing liver biopsies in patients with a CBD for the purpose of guiding prognostic and therapeutic decisions. We report here the results of our centre's experience with transjugular liver biopsy (TJLB) in patients with a CBD. An adequate specimen for histological assessment was attained from all of the patients. There were no major complications recorded. Patients were hospitalized for < or = 48 h for haemostasis prophylaxis. The diagnostic specimen obtained from patients was integral in guiding their future management. We suggest that with a coordinated multidisciplinary approach, TJLB can be performed in patients with a CBD.

In situ reflection electron microscopy of Ge island nucleation on mesa structures.

We have used in situ electron microscopy to observe the nucleation of Ge islands on lithographically patterned Si(001) mesas. Images were obtained at video rate during chemical vapor deposition of Ge, using a reflection electron microscopy geometry that allows nucleation to be observed over large areas. By comparing the kinetics of nucleation and coarsening on substrates modified by different annealing conditions, we find that the final island arrangement depends on the nature of the mesa sidewalls, and we suggest that this may be due to changes in diffusion of Ge across the nonplanar surface.

Treatment of drinking water residuals: comparing sedimentation and dissolved air flotation performance with optimal cation ratios.

Spent filter backwash water (SFBW) and clarifier sludge generally comprise the majority of the waste residual volume generated and in relative terms, these can be collectively referred to as combined filter backwash water (CFBW). CFBW is essentially a low-solids wastewater with metal hydroxide flocs that are typically light and slow to settle. This study evaluates the impact of adding calcium and magnesium carbonates to CFBW in terms of assessing the impacts on the sedimentation and DAF separation processes. Representative CFBW samples were collected from two surface water treatment plants (WTP): Lake Major WTP (Dartmouth, Nova Scotia, Canada) and Victoria Park WTP (Truro, Nova Scotia, Canada). Bench-scale results indicated that improvements in the CFBW settled water quality could be achieved through the addition of the divalent cations, thereby adjusting the monovalent to divalent (M:D) ratios of the wastewater. In general, the DAF process required slightly higher M:D ratios than the sedimentation process. The optimum M:D ratios for DAF and sedimentation were determined to be 1:1 and 0.33:1, respectively. It was concluded that the optimisation of the cation balance between monovalent cations (e.g., Na(+), K(+)) and added divalent cations (i.e., Ca(2+), Mg(2+)) aided in the settling mechanism through charge neutralisation-precipitation. The increase in divalent cation concentrations within the waste residual stream promoted destabilisation of the negatively charged colour molecules within the CFBW, thereby causing the colloidal content to become more hydrophobic.

RDX loss in a surface soil under saturated and well drained conditions.

On military training ranges, low-order, incomplete detonations deposit RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) into surface soils. In this study, we evaluated RDX biodegradation in surface soils obtained from a military training range in Alaska. Two factors were compared: (i) soil water potential during the incubations; and (ii) the use of acetonitrile (ACN) as an RDX carrier to spike samples. Organic solvents have been used in laboratory studies to dissolve slightly water-soluble contaminants before addition to soil. We added ACN to obtain final soil ACN concentrations of 0 mg kg(-1) (0%), 1000 mg kg(-1) (0.1%) and 10 000 mg kg(-1) (1%). We then compared RDX attenuation in the soil under saturated and unsaturated conditions. RDX fell below the limit of detection within 3 wk of study initiation under the saturated condition. A maximum degradation rate of 0.15 mg RDX L(-1) d(-1) was measured. Under the unsaturated condition, 42% of the original RDX was still present at study termination (5 wk). The addition of acetonitrile at 0.1 or 1.0% had no affect on RDX loss in the saturated soil. In the unsaturated soil, however, ACN at 1.0% inhibited RDX loss by as much as 25%. These findings indicate that soil water potential and carrier solvent concentrations can impact the rate and extent to which RDX is attenuated in a surface soil.

Peripheral arterial disease detection, awareness, and treatment in primary care.

CONTEXT: Peripheral arterial disease (PAD) is a manifestation of systemic atherosclerosis that is common and is associated with an increased risk of death and ischemic events, yet may be underdiagnosed in primary care practice. OBJECTIVE: To assess the feasibility of detecting PAD in primary care clinics, patient and physician awareness of PAD, and intensity of risk factor treatment and use of antiplatelet therapies in primary care clinics. DESIGN AND SETTING: The PAD Awareness, Risk, and Treatment: New Resources for Survival (PARTNERS) program, a multicenter, cross-sectional study conducted at 27 sites in 25 cities and 350 primary care practices throughout the United States in June-October 1999. PATIENTS: A total of 6979 patients aged 70 years or older or aged 50 through 69 years with history of cigarette smoking or diabetes were evaluated by history and by measurement of the ankle-brachial index (ABI). PAD was considered present if the ABI was 0.90 or less, if it was documented in the medical record, or if there was a history of limb revascularization. Cardiovascular disease (CVD) was defined as a history of atherosclerotic coronary, cerebral, or abdominal aortic aneurysmal disease. MAIN OUTCOME MEASURES: Frequency of detection of PAD; physician and patient awareness of PAD diagnosis; treatment intensity in PAD patients compared with treatment of other forms of CVD and with patients without clinical evidence of atherosclerosis. RESULTS: PAD was detected in 1865 patients (29%); 825 of these (44%) had PAD only, without evidence of CVD. Overall, 13% had PAD only, 16% had PAD and CVD, 24% had CVD only, and 47% had neither PAD nor CVD (the reference group). There were 457 patients (55%) with newly diagnosed PAD only and 366 (35%) with PAD and CVD who were newly diagnosed during the survey. Eighty-three percent of patients with prior PAD were aware of their diagnosis, but only 49% of physicians were aware of this diagnosis. Among patients with PAD, classic claudication was distinctly uncommon (11%). Patients with PAD had similar atherosclerosis risk factor profiles compared with those who had CVD. Smoking behavior was more frequently treated in patients with new (53%) and prior PAD (51%) only than in those with CVD only (35%; P <.001). Hypertension was treated less frequently in new (84%) and prior PAD (88%) only vs CVD only (95%; P <.001) and hyperlipidemia was treated less frequently in new (44%) and prior PAD (56%) only vs CVD only (73%, P<.001). Antiplatelet medications were prescribed less often in patients with new (33%) and prior PAD (54%) only vs CVD only (71%, P<.001). Treatment intensity for diabetes and use of hormone replacement therapy in women were similar across all groups. CONCLUSIONS: Prevalence of PAD in primary care practices is high, yet physician awareness of the PAD diagnosis is relatively low. A simple ABI measurement identified a large number of patients with previously unrecognized PAD. Atherosclerosis risk factors were very prevalent in PAD patients, but these patients received less intensive treatment for lipid disorders and hypertension and were prescribed antiplatelet therapy less frequently than were patients with CVD. These results demonstrate that underdiagnosis of PAD in primary care practice may be a barrier to effective secondary prevention of the high ischemic cardiovascular risk associated with PAD.

Determination of nitroaromatic, nitramine, and nitrate ester explosives in soil by gas chromatography and an electron capture detector.

Hazardous waste site characterization, forensic investigations, and land mine detection are scenarios where soils may be collected and analyzed for traces of nitroaromatic, nitramine, and nitrate ester explosives. These thermally labile analytes are traditionally determined by high-performance liquid chromatography (HPLC); however, commercially available deactivated injection port liners and wide-bore capillary columns have made routine analysis by gas chromatography (GC) possible. The electron-withdrawing nitro group common to each of these explosives makes the electron capture detector (ECD) suitable for determination of low concentrations of explosives in soil, water, and air. GC-ECD and HPLC-UV concentration estimates of explosives residues in field-contaminated soils from hazardous waste sites were compared, and correlation (r>0.97) was excellent between the two methods of analysis for each of the compounds most frequently detected: 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4-dinitrotoluene (2,4-DNT), 1,3-dinitrobenzene (1,3-DNB), 1,3,5-trinitrobenzene (TNB), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The analytes were extracted from soils with acetonitrile by 18 h of sonication in a cooled ultrasonic bath. Two soil-to-solvent ratios were evaluated: 2.00 g:10.00 ml and 25.0 g:50.0 ml. GC-ECD method detection limits were similar for the two soil-to-solvent ratios and were about 1 mug kg(-1) for the di- and trinitroaromatics, about 10 mug kg(-1) for the mono-nitroaromatics, 3 mug kg(-1) for RDX, 25 mug kg(-1) for HMX, and between 10 and 40 mug kg(-1) for the nitrate esters (nitroglycerine [NG] and pentaerythritol tetranitrate [PETN]). Spike recovery studies revealed artifacts introduced by the spiking procedure. Recoveries were low in some soils if the amount of soil spiked was large (25.0 g) compared to the volume of spike solution added (1.00 ml). Recoveries were close to 100% when 2.00-g soil samples were spiked with 1.00 ml of solution. Analytes most frequently found in soils collected near buried land mines were the microbial transformation products of TNT (2-amino-4,6-dinitrotoluene [2-Am-DNT] and 4-amino-2,6-dinitrotoluene [4-Am-DNT]), manufacturing impurities of TNT (2,4-DNT, 2,6-DNT, and 1,3-DNB), and TNT. The microbial reduction products of the isomers of DNT and of 1,3-DNB were also detected, but the ECD response to these compounds is poor.

Chemical signatures of TNT-filled land mines.

The equilibrium headspace above several military-grade explosives was sampled using solid phase microextraction fibers and the sorbed analytes determined using gas chromatography with an electron capture detector (GC-ECD). The major vapors detected were the various isomers of dinitrotoluene (DNTs), dinitrobenzene (DNBs), and trinitrotoluene (TNTs), with 2,4-DNT and 1,3-DNB often predominating. Although 2,4,6-TNT made up from 50 to 99% of the solid explosive, it was only a minor component of the equilibrium vapor. The flux of chemical signatures from intact land mines is thought to originate from surface contamination and evolution of vapors via cracks in the casing and permeation through polymeric materials. The levels of external contamination were determined on a series of four types of Yugoslavian land mines (PMA-1A, PMA2, TMA5 and TMM1). The flux into air as a function of temperature was determined by placing several of these mines in Tedlar bags and measuring the mass accumulation on the walls of the bags after equilibrating the mine at one of five temperatures. TNT was a major component of the surface contamination on these mines, yet it accounted for less than 10% of the flux for the three plastic-cased mines, and about 33% from the metal antitank mine (TMM1). Either 2,4-DNT or 1,3-DNB produced the largest vapor flux from these four types of land mines. The environmental stability of the most important land mine signature chemicals was determined as a function of temperature by fortifying soils with low aqueous concentrations of a suite of these compounds and analyzing the remaining concentrations after various exposure times. The kinetics of loss was not of first order in analyte concentration, indicating that half-life is concentration dependent. At 23 degrees C, the half life of 2,4,6-TNT, with an initial concentration of about 0.5 mg kg(-1), was found to be only about 1 day. Under identical conditions, the half-life of 2,4-DNT was about 25 days. A research minefield was established and a number of these same four mine types were buried. Soil samples were collected around several of these mines at several time periods after burial and the concentration of signature chemicals determined by acetonitrile extraction and GC-ECD analysis. Relatively high concentrations of 2,4,6-TNT and 2,4-DNT were found to have accumulated beneath a TMA5 antitank mine, with lower concentrations in the soil layers between the mine and the surface. Signatures were distributed very heterogeneously in surface soils, and concentrations were very low (low mug kg(-1) range). Lower, but detectable, concentrations of signatures were detectable irregularly in soils near the PMA-1A mines in contrast to the TMA5 mines. Concentrations of signature chemicals were generally below detection limits (<1 mug kg(-1)) near the TMM1 and PMA-2 mines, even 8 months after burial.

Minimizing venous thromboembolic complications in the orthopaedic patient.

Venous thromboembolic events (VTE), which include deep venous thrombosis (DVT) and pulmonary embolus (PE), are the most common life-threatening complications associated with orthopaedic surgical procedures. DVT is particularly prevalent in patients undergoing total knee and hip arthroplasty, occurring at a rate of 50 to 60%. In addition, up to 2% of orthopaedic patients receiving pharmacologic prophylaxis still develop PE. Because the majority of candidates for these procedures are older adults with a multitude of comorbid conditions, standard prophylactic practices may not always result in optimal clinical outcomes. Thus, it is important for nurses to have a general understanding of appropriate thromboprophylaxis. This article will provide an overview of the current recommended guidelines and explore the risks and benefits of both pharmacologic agents and adjunctive treatment modalities.

Catalytic reductive dehalogenation of hexachloroethane by molecular variants of cytochrome P450cam (CYP101).

CYP101 (cytochrome P450cam) catalyses the oxidation of camphor but has also been shown to catalyse the reductive dehalogenation of hexachloroethane and pentachloroethane. This reaction has potential applications in the biodegradation of these environmental contaminants. The hexachloroethane dehalogenation activity of CYP101 has been investigated by mutagenesis. The effects of active-site polarity and volume were probed by combinations of active-site mutations. Increasing the active-site hydrophobicity by the Y96A and Y96F mutations strengthened hexachloroethane binding but decreased the rate of reaction. Increasing the polarity with the F87Y mutation drastically weakened hexachloroethane binding but did not affect the rate of reaction. The Y96H mutation had little effect at pH 7.4, but weakened hexachloroethane binding while increasing the rate of dehalogenation by up to 40% at pH 6.5, suggesting that the imidazole side-chain was partially protonated at pH 6.5 but not at pH 7.4. Substitutions by bulkier side-chains at F87, T101 and V247 weakened hexachloroethane binding but increased the dehalogenation rate. The effect of the individual mutations was additive in multiple mutants, and the most active mutant for hexachloroethane reductive dehalogenation at pH 7.4 was F87W-V247L (80 min-1 or 2.5 x the activity of the wild-type). The results suggested that the CYP101 active site shows good match with hexachloroethane, the Y96 side-chain plays an important role in both hexachloroethane binding and dehalogenation, and hexachloroethane binding and dehalogenation places conflicting demands on active-site polarity and compromises were necessary to achieve reasonable values for both.

Solitary fibrous tumour of the forearm. A rare tumour in an atypical site.

Solitary fibrous tumour (SFT) is a rare spindle cell neoplasm that usually arises from serosal surfaces. Although it is now increasingly recognized in extra-serosal locations, only two previous cases of SFT arising in an extremity have been reported. We describe another such case and review the literature regarding extra-serosal SFT.