Nasotracheal fibreoptic intubation: a randomised controlled trial comparing the GlideRite® (Parker-Flex® Tip) nasal tracheal tube with a standard pre-rotated nasal RAE™ tracheal tube.

In a randomised controlled study, we compared the ease of railroading a GlideRite® nasal tracheal tube over a fibrescope with that of a pre-rotated RAE™ nasal tracheal tube. We studied 110 anaesthetised patients with no known airway difficulties undergoing elective dental or maxillofacial surgery. Impingement was more common with the GlideRite tubes (11/55 (20%)) compared with the pre-rotated RAE tubes (3/55 (5%); p=0.02). The median (IQR [range]) time to intubation (GlideRite 7.6 (4.7-10.8 [3.0-46.2]) s; RAE 8.0 (6.2-10.7 [2.4-30.0]) s) and postoperative sore throat numerical ratings (GlideRite 2 (0-3 [0-10]); RAE 2 (0-5 [0-8])) were similar. A 90° anticlockwise pre-rotation of a standard nasal RAE tube has a higher initial rate of successful railroading at first attempt and is therefore superior to a GlideRite nasotracheal tube during nasal fibreoptic intubation.

Knowledge transfer principles as applied to sport concussion education.

OBJECTIVE: To (a) examine knowledge transfer literature and optimal learning needs as applied to healthcare professionals, coaches and student athletes; (b) apply the practice of knowledge transfer to sport concussion education resources; and (c) identify needs and make recommendations for optimising concussion education. DESIGN: Qualitative literature review of knowledge transfer and concussion education literature. INTERVENTION: Pubmed, Medline, Psych Info and Sport Discus databases were reviewed. 52 journal articles, 20 websites and 2 books were reviewed. RESULTS: The methods in which individuals experience optimal learning varies and should be considered when developing effective concussion education strategies. Physician knowledge and performance are impacted by education outreach, interaction and reminder messages. Educational strategies associated with optimal learning for physio and athletic therapists include problem and evidence-based practice, socialisation and peer-assisted learning. From a coaching perspective, research supports the reflective process as a learning modality. Student athletes have strengths and weaknesses in different areas and so perform differently on activities requiring distinct strategies. Knowing the impact of sport concussion resources on knowledge enhancement and modifying attitudes and behaviours toward concussion requires evaluation strategies. Review of concussion resources using the perspective of knowledge transfer and methods for improvement is discussed. CONCLUSIONS: Knowledge transfer is a relatively new concept in sports medicine and its influence on enhancing concussion education is not well known. The needs and optimal learning styles of target audiences coupled with evaluation need to be a piece of the overall concussion education puzzle to effectively impact knowledge of and attitudes and behaviours towards sport concussion.

Synthesis and biological evaluation of 2-acyl analogues of paclitaxel (Taxol).

The anticancer drug paclitaxel (Taxol) has been converted to a large number of 2-debenzoyl-2-aroyl derivatives by three different methods. The bioactivities of the resulting analogues were determined in both tubulin polymerization and cytotoxicity assays, and several analogues with enhanced activity as compared with paclitaxel were discovered. Correlation of cytotoxicity in three cell lines with tubulin polymerization activity showed reasonable agreement. Among the cell lines examined, the closest correlation with antitubulin activity was observed with a human ovarian carcinoma cell line.

Comparison of conduits for leg revascularization.

The saphenous vein (SV) remains the conduit of choice for lower limb revascularization. When SV is unavailable, or unsuitable, two alternative conduits have been employed: gluteraldehydestablized human umbilical vein (HUV) and polytetrafluoroethylene (PTFE). In this study of the 218 patients who underwent lower limb revascularization, 3-year patency of 85 SV graft was 75% compared to 34% for the 66 HUV grafts and 33% for the 67 PFTE grafts. Three factors were found to independently influence patency: the indication for surgery, the site of the distal anastomosis, and the angiographic runoff. The SV group had significantly better patency than either HUV or PFTE in each of these subgroups. No consistent difference between HUV and PTFE was found. A risk score was obtained by assigning a value of 1 to 3 for each of the factors influencing patency--indication: 1 = claudication, 2 = rest pain, 3 = ischemic lesions; site: 1 = above knee (AK), 2 = below knee (BK), 3 = tibial; runoff 1 = good (two or three vessels), 2 = fair (one vessel), 3 = poor (no vessel). Patients with the lowest risk scores (3 to 4) had the best 3-year patency: SV, 78%; HUV, 44%; and PTFE, 48%. Patients with the highest risk scores (7 to 9) had the worst 3-year patency: SV, 68%; HUV, 32%; and PTFE, 28%. SVs had better patency under high- and low-risk conditions and remain the conduit of choice for lower limb revascularization. Both HUV and PTFE have equivalent and acceptable patency when SV is unavailable or unstable.

Recommendations for grading of concussion in athletes.

Mild sports-related concussions, in which there is no loss of consciousness, account for >75% of all sports-related brain injury. Universal agreement on concussion definition and severity grading does not exist. Grading systems represent expertise of clinicians and researchers yet scientific evidence is lacking. Most used loss of consciousness and post-traumatic amnesia as markers for grading concussion. Although in severe head injury these parameters may have been proven important for prognosis, no study has done the same for sport-related concussion. Post-concussion symptoms are often the main features to help in the diagnosis of concussion in sport. Neuropsychological testing is meant to help physicians and health professionals to have objective indices of some of the neurocognitive symptoms. It is the challenge of physicians, therapists and coaches involved in the care of athletes to know the symptoms of concussion, recognise them when they occur and apply basic neuropsychological testing to help detect this injury. It is, therefore, recommended to be familiar with one grading system and use it consistently, even though it may not be scientifically validated. Then good clinical judgement and the ability to recognise post-concussion signs and symptoms will assure that an athlete never returns to play while symptomatic.

Encapsulation of lysozyme in a biodegradable polymer by precipitation with a vapor-over-liquid antisolvent.

Lysozyme was encapsulated in biodegradable polymer microspheres which were precipitated from an organic solution by spraying the solution into carbon dioxide. The polymer, either poly(l-lactide) (l-PLA) or poly(DL-lactide-co-glycolide) (PGLA), in dichloromethane solution with suspended lysozyme was sprayed into a CO2 vapor phase through a capillary nozzle to form droplets which solidified after falling into a CO2 liquid phase. By delaying precipitation in the vapor phase, the primary particles became sufficiently large, from 5 to 70 microm, such that they could encapsulate the lysozyme. At an optimal temperature of -20 degrees C, the polymer solution mixed rapidly with CO2, and the precipitated primary particles were sufficiently hard such that agglomeration was markedly reduced compared with higher temperatures. More uniform particles were formed by flowing CO2 at high velocity in a coaxial nozzle to mix the droplets at the CO2 vapor-liquid interface. This process offers a means to produce encapsulated proteins in poly(DL-lactide-co-glycolide) microspheres without earlier limitations of massive polymer agglomeration and limited protein solubility in organic solvents.

Fate and transport of copper-based crop protectants in plasticulture runoff and the impact of sedimentation as a best management practice.

The fate and distribution of copper-based crop protectants, applied to plasticulture tomato fields to protect against disease, were investigated in a greenhouse-scale simulation of farming conditions in a coastal environment. Following rainfall, 99% of the applied copper was found to remain on the fields sorbed to the soil and plants; most of the soil-bound copper was found sorbed to the top 2.5 cm of soil between the plasticulture rows. Of the copper leaving the agricultural fields, 82% was found in the runoff with the majority, 74%. sorbed to the suspended solids. The remaining copper, 18%, leached through the soil and entered the groundwater with 10% in the dissolved phase and 8% sorbed to suspended solids. Although only 1% copper was found to leave the field, this was sufficient to cause high copper concentrations (average 2102+/-433 microg/L total copper and 189+/-139 microg/L dissolved copper) in the runoff. Copper concentrations in groundwater samples were also high (average 312+/-198 microg/L total copper and 216+/-99 microg/L dissolved copper). Sedimentation, a best management practice for reducing copper loadings. was found to reduce the total copper concentrations in runoff by 90% to a concentration of 245+/-127 microg/L; however, dissolved copper concentrations remained stable, averaging 139+/-55 microg/L. Total copper concentrations were significantly reduced by the effective removal of suspended solids with sorbed copper.

Predictors of long-term patient survival after in situ vein leg bypass.

PURPOSE: The objective was to determine the long-term survival rates of patients who undergo distal arterial bypass surgery and to identify the preoperative factors that are predictive of survival. METHODS: Three hundred fifty-eight consecutive in situ distal leg bypass procedures were performed between July 1986 and December 1995. The relationship between 13 preoperative variables and late survival were determined using both univariate (Kaplan-Meier) and multivariate (Cox regression) statistical techniques. RESULTS: The cumulative survival rates at 1, 3, 5, and 7 years were 86.6% +/- 2.0%, 63.2% +/- 3.0%, 46.9% +/- 3.4%, and 35.3% +/- 3.8%, respectively. Using Cox regression, four significant variables were found to be associated with lower late survival rates: male gender, diabetes, chronic renal insufficiency (patients with creatinine levels greater than or equal to 1.7 mg/dl or 150 SI units), and a history of cerebrovascular disease (p < 0.001 for model). When none of these four variables were present, the predicted 5-year survival rate was 71%, whereas the survival rate was reduced to 43% to 60% when one was present, 23% to 42% when two were present, 8% to 22% when three were present, and 2% when all four were present. CONCLUSIONS: This study defines the long-term survival rates in a cohort of patients after undergoing distal bypass surgery and demonstrates that certain preoperative factors are predictive of late survival. Knowledge of these factors may be useful to assist in individual operative decisions between aggressive attempts at distal revascularization versus primary amputation.

A chromogenic assay for the detection of plasmin generated by plasminogen activator immobilized on nitrocellulose using a para-nitroanilide synthetic peptide substrate.

A direct solid phase chromogenic assay has been developed for the detection of plasmin (EC 3.4.21.7), generated by the interaction of a nitrocellulose-bound plasminogen activator, using the plasmin specific tripeptide substrate, H-D-valyl-leucyl-lysine - p-nitroaniline. para-Nitroaniline released by the cleavage of the lysine - p-nitroaniline bound by plasmin was derivatized to its diazonium salt and subsequently coupled to N-1-napthylethylenediamine in situ to form a diazoamino of an intense red color at the site of the plasminogen activator. This method was used to assay for the streptococcal plasminogen activator, streptokinase, not only in crude bacterial supernatants, but also to detect streptokinase secreted by individual bacterial colonies. In addition, this solid phase assay was used to identify monoclonal antibodies specific for streptokinase which could inhibit the activation of human plasminogen by streptokinase. This method also permitted simultaneous immunological and biochemical identification of the plasminogen activator, thus permitting unequivocal comparative observations. This assay is quantitative and sensitive to nanogram amounts of activator comparable to those obtained with soluble assays. This method may also be applicable for the detection of other plasminogen activators, such as tissue plasminogen activator, urokinase, and staphylokinase, and also for the detection of immobilized proteases which can cleave other substrates derivatized with p-nitroaniline. The reagents used in this assay are inexpensive and easy to prepare.

In vitro hemodynamic evaluation of a Simon nitinol vena cava filter: possible explanation of IVC occlusion.

PURPOSE: To evaluate the local hemodynamics in the region of the Simon nitinol filter (SNF), used to prevent pulmonary emboli by capturing clot and promoting lysis. MATERIALS AND METHODS: The hemodynamics of the Simon nitinol inferior vena cava (IVC) filter were evaluated under steady flow (Re = 600) in a 20-mm-diameter IVC model. The photochromic dye tracer technique was used to estimate the velocity and wall shear stress. These flow features were determined for the unoccluded and partially occluded (clot volume = 1,500 mm(3)) states of the SNF along its center plane. RESULTS: A region of low velocities developed around the central axis of the filter extending from the leading edge of the central strut to the filter tip. This phenomenon was created by the strong redirection of flow toward the periphery of the filter. With the presence of the clot, these effects were enhanced, causing flow separation and recirculation. In addition, the shear stress on the hip of the clot was about 30 times that of the upstream value, and turbulence developed in the near-downstream region. CONCLUSIONS: The extended region of almost-stagnant flow near the midsection of the umbrella region could lead to organization of thrombus and fibrin mesh network development. The presence of a simulated clot led to a significant increase in the size of the stagnant, thrombus-prone region as well as turbulence, which, overall, may contribute to caval occlusion.

Loosening of massive proximal femoral cemented endoprostheses. Radiographic evidence of loosening mechanism.

A review of the radiographs of 24 patients with massive proximal femoral cemented tumor endoprostheses revealed a repetitive radiographic sequence that culminated in implant loosening. The initial step was osteolysis of the proximal femur at the bone-prosthesis junction (13 of 24 cases, 54%). The osteolysis then progressed into the adjacent periprosthetic bone-cement interface as a radiolucent line (5 of 24 cases, 21%), followed by extension along the stem, culminating in implant loosening (4 of 24 cases, 17%). Two prostheses (8%) have required revision for loosening. The proximal osteolysis was noted prior to the appearance of progressive periprosthetic radiolucent lines in 11 patients and simultaneously in 2 but never followed periprosthetic radiolucent lines (P < .05). These findings are consistent with loosening by debris-induced osteolysis. This loosening sequence, confirming previous observations of cemented component loosening, should encourage efforts to prevent or delay the onset of this sequence.

Nevoid basal cell carcinoma syndrome in a black child.

Nevoid basal cell carcinoma syndrome (NBCCS) is rare in black persons. We describe an 11-year-old black boy with NBCCS who presented with exotropia and a painful, expanding, cystic mass in the left posterior alveolar ridge. Further examination revealed odontogenic keratocysts with palmar and plantar pitting. Less than 5% of reported patients with NBCCS are black. To our knowledge, this is the first report of a black patient with NBCCS presenting with exotropia and an impacted molar displaced into the orbit by an odontogenic keratocyst.

A rapid, sensitive method for detection of alkaline phosphatase-conjugated anti-antibody on Western blots.

A rapid, sensitive method has been developed to detect antibody-antigen complexes on "Western blots." The methods of H. Towbin, T. Staehlin, and J. Gordon were used to separate and blot the antigens onto nitrocellulose. The remaining sites of attachment were blocked and the nitrocellulose was washed with polyoxyethylenesorbitan monolaurate (Tween 20). The blot was then reacted with the antiserum or hybridoma supernate to be tested. After the antigen-antibody reaction was completed, the blot was washed and treated with anti-antibody which had been conjugated to alkaline phosphatase. The alkaline phosphatase was detected by the reduction of the tetrazolium salt to diformazan by the hydrogen ions released in the formation of indigo by the reaction of the phosphatase on the indoxyl phosphate. The advantages of this method over previously described techniques are (1) use of Tween 20 allows the blot to be stained with Coomassie blue, (2) the substrates of the alkaline phosphatase reaction are stable for long periods of time, (3) the reaction products form an intense blue color which does not fade, (4) the resolution is extremely good with little to no band broadening, (5) the reaction is sensitive to picogram quantities of antigen, and (6) the reaction is quantitative.

Steady and pulsatile flow fields in an end-to-side arterial anastomosis model.

We investigated the flow field within a rigid-walled in vitro model of an end-to-side 45 degree anastomosis in an attempt to identify possible hemodynamic factors that may contribute to the pathogenesis of distal anastomotic intimal hyperplasia. A high-resolution photochromic tracer technique was used to visualize the flow in orthogonal planes and to determine the axial wall shear stress profiles for both steady and pulsatile flows over a range of physiologically relevant conditions. The flow field showed qualitative similarities to those seen in curved vessel: rapidly moving fluid from the graft section affects the bed of the host vessel, that is, the wall opposite the anastomosis, eventually advancing down the host vessel in a spiraling motion. A small mobile separation zone was noted at the toe of the anastomosis. Comparison of wall shear stress profiles with previously reported preferential sites for the development of intimal hyperplasia supported a low wall shear stress and/or flow separation pathogenesis hypothesis. One notable exception was the bed of the host artery that appeared to be subjected to a complex hemodynamic environment.

Detection of lipopolysaccharides blotted to polyvinylidene difluoride membranes.

Bacterial lipopolysaccharide (LPS) blotted to polyvinylidene difluoride (PVDF) membranes was detected by a technique adapted from current methodologies used to detect glycoproteins. PVDF-bound LPS was coupled to a hapten and localized on the membrane by Western blotting with an antibody-alkaline phosphatase conjugate specific for the hapten. Immobilon blots could be made reversibly transparent for photography and densitometry.