Water droplet evaporation in varied gravity and electric fields.

Sessile water droplet evaporation in varied gravity and electric fields has been experimentally studied. Specifically, the influences of gravity and electric fields are investigated in the context of the heat flux distribution beneath the droplets, as well as the droplet mechanics and resulting shapes. Experimental testing was carried out during a European Space Agency (ESA) Parabolic Flight Campaign (PFC 66). The droplets tested evaporated with a pinned contact line, a single wettability condition, and varied droplet volume and substrate heat flux. The peak heat transfer was located at the contact line for all cases. The peak heat flux, average heat flux, and droplet evaporation rate were shown to vary strongly with gravity, with higher values noted for hypergravity conditions and lower values in microgravity conditions. The droplet thermal inertia was shown to play a significant role, with larger droplets taking more time to reach thermal equilibrium during the parabolic testing period. No significant impact of the electric field on the droplet evaporation was noted for these test conditions.

Anaesthetic management of an emergency caesarean section in a complex immunologically compromised patient with pre-eclampsia and multifactorial thrombocytopaenia.

A 35-year-old gravida 3, para 0 woman required an emergency caesarean section for pre-eclampsia with severe features including a platelet count of 7 × 109.l-1. The patient's thrombocytopaenia was an acute on chronic presentation. In addition to pre-eclampsia, the patient had a complex background history which included autoimmune lymphoproliferative syndrome, the manifestations of which include autoimmune cytopaenias and recurrent infections. The patient also had common variable immune deficiency and acquired C1-esterase inhibitor deficiency which may cause life-threatening angioedema, including of the airway. In this report, we describe the potential anaesthetic challenges posed by this pre-eclamptic, immunologically compromised patient with severe thrombocytopaenia and the potential for difficult airway, and how these were addressed in a safe and timely manner. Specifically, we highlight the important considerations when performing a general anaesthetic in this unique combination of circumstances. Although the patient's conditions are rare, this case demonstrates that early multidisciplinary team input can help successfully guide the management of medically complex pregnant patients.

Permanent hearing loss and tinnitus following epidural analgesia complicated by accidental dural puncture.

We report a case of permanent high-frequency hearing loss and tinnitus in a 38-year-old woman following an unrecognised dural puncture during epidural placement. The patient reported subjective unilateral hearing loss and tinnitus, along with a post-dural puncture headache, four hours post-delivery. The patient's headache resolved following two epidural blood patches, however, hearing loss and tinnitus persisted longer than two years. Long-term auditory symptoms following epidural analgesia in labour are very unusual findings.

Peri-operative ventricular bigeminy and cardiomyopathy in elective surgery.

Premature ventricular contractions are common in the general population and are often seen during general anaesthesia. A high frequency of premature ventricular contractions may be associated with underlying left ventricular dysfunction. Premature ventricular contraction-induced cardiomyopathy is a rare disease and requires cardiologist input into peri-operative management. Medical and interventional management strategies may completely reverse the disease process. A 19-year-old man was scheduled for removal of tibial metalwork, due to chronic pain, and ventricular bigeminy was noted in the anaesthetic room before induction of anaesthesia. Surgery was postponed and he was later diagnosed with premature ventricular contraction-induced cardiomyopathy. Ventricular bigeminy noted before induction of anaesthesia may not always be benign.

Canis Caveat (Beware of the Dog) - Septic Shock Due To Capnocytophaga Canimorsus Contracted From A Dog Bite

We describe the case of a 61-year-old immunocompetent male who developed septic shock and multiorgan failure due to Capnocytophaga canimorsus (C. canimorsus) bloodstream infection, sustained from a dog bite. Unusually, this patient developed acute liver failure and splenic infarction in addition to many of the better-known clinical sequelae of C. canimorsus infection.

Peer teaching as a means of enhancing communication skills in anaesthesia training: trainee perspectives.

PURPOSE: The purpose of this study is to introduce peer teaching of communication skills to first-year anaesthesia trainees in Ireland and to evaluate their perception of this teaching modality. METHODS: Seventy-nine first-year anaesthesia trainees participated in a novel peer-led communication skills programme over a 2-year period (Y1, Y2). A Likert scaling questionnaire was developed to explore trainee perception of the peer teaching programme. RESULTS: Of the 79 respondents (36 in Y1 and 43 in Y2), 99% either agreed or strongly agreed that the peer teachers were successful in their role. Ninety-two percent requested formal peer teaching in other areas of training. The trainees regarded a peer teacher as an appropriate information provider (92%), role model (88%), planner (88%) and facilitator (94%), but less so as an assessor (70%). The most consistently stated strength of peer teaching was the relatability of peer teachers with their lack of experience cited as the main weakness. Eighty percent of participants preferred peer teaching to regular expert teaching. CONCLUSION: This study highlights the positive attitudes of first-year anaesthesia trainees towards a novel peer teaching programme in communication skills. This author recommends that peer teaching is further developed within postgraduate medical programmes to maximise learning for trainees in the student and teacher roles and to redistribute the teaching burden within clinical departments.

Relationships Between Early Wheat Streak Mosaic Severity Levels and Grain Yield: Implications for Management Decisions.

Wheat streak mosaic (WSM) caused by Wheat streak mosaic virus, which is transmitted by the wheat curl mite (Aceria tosichella), is a major yield-limiting disease in the Texas High Plains. In addition to its impact on grain production, the disease reduces water-use efficiency by affecting root development. Because of the declining Ogallala Aquifer water level, water conservation has become one of the major pressing issues in the region. Thus, questions are often raised as to whether it is worthwhile to irrigate infected fields in light of the water conservation issues, associated energy costs, and current wheat prices. To address some of these questions, field experiments were conducted in 2013 and 2016 at two separate locations to determine whether grain yield could be predicted from disease severity levels, assessed early in the spring, for potential use as a decision tool for crop management, including irrigation. In both fields, disease severity assessments started in April, using a handheld hyperspectral radiometer with which reflectance measurements were taken weekly in multiple plots in arbitrarily selected locations across the fields. The relationship between WSM severity levels and grain yield for the different assessment dates were determined by fitting reflectance and yield values into the logistic regression function. The model predicted yield levels with r2 values ranging from 0.67 to 0.85 (P < 0.0001), indicating that the impact of WSM on grain yield could be fairly well predicted from early assessments of WSM severity levels. As the disease is normally progressive over time, this type of information will be useful for making management decisions of whether to continue irrigating infected fields, especially if combined with an economic threshold for WSM severity levels.

Nitrogen loss during solar drying of biosolids.

Solar drying has been used extensively to dewater biosolids for ease of transportation and to a lesser degree to reduce pathogens prior to land application. The nitrogen in biosolids makes them a relatively inexpensive but valuable source of fertilizer. In this study, nitrogen loss from tilled and untilled biosolids was investigated during the solar drying process. Samples of aerobically and anaerobically digested biosolids during three solar drying experiments were analyzed for their nitrate (NO3-) and ammonium (NH4+) ions concentrations. Nitrogen losses varied depending on the solar drying season and tillage. Although not directly measured, the majority of nitrogen loss occurred through ammonia volatilization; organic nitrogen content (organic N) remained relatively stable for each sample, nitrate concentrations for the majority of samples remained below detectable levels and the decline of ammonium-nitrogen (NH4(+)-N) generally followed the trend of moisture loss in the biosolids.

Evaluation of perineurial differentiation in epithelioid sarcoma.

AIMS: To investigate the differentiation pattern of epithelioid sarcoma in terms of perineurial and endothelial differentiation, and its relationship to that of meningioma. METHODS AND RESULTS: Nine cases of epithelioid sarcoma and five cases of meningioma were studied in an immunohistochemical analysis of 'perineurial' antigens [GLUT-1, claudin-1, epithelial membrane antigen (EMA) and VE-cadherin] and of 'endothelial' antigens not present on normal perineurium (CD34, CD31, Fli-1). Both epithelioid sarcoma and meningioma showed frequent expression of the perineurial markers GLUT-1, claudin-1 and EMA. VE-cadherin was identified in one of five meningiomas, and in the only case of epithelioid sarcoma in which suitably fixed material was available. CD34 was expressed by all epithelioid sarcomas studied but by none of the meningiomas. Fli-1 was present in a substantial majority of epithelioid sarcomas and by all the meningiomas. CD31 was not detected in any epithelioid sarcoma or meningioma. CONCLUSIONS: The results were evaluated in the context of previous immunohistochemical, ultrastructural and genetic studies and suggest that epithelioid sarcoma may be a form of malignant perineurioma with a range of differentiation (epithelial features) akin to that seen in meningioma, reflecting the close relationship between perineurium and meningothelium.

A minimally invasive percutaneous technique of intramedullary nail insertion in an animal model of fracture healing.

Previous animal models of fracture repair have been shown to be reproducible but are often time-inefficient. We present a minimally invasive percutaneous technique for retrograde insertion of intramedullary pins in a model of rat femoral fracture healing. Forty Sprague-Dawley rats were divided into 3 groups: no fracture (n = 6), no fracture but pinned (n = 6), and fractured and pinned (n = 24). The pins were inserted in a percutaneous manner under fluoroscopic control. No incisions were made. All animals tolerated the procedure well and were using the operated leg within hours after the surgery. The mean time for the pinning procedure was 2.3 min (standard deviation 1.1 min). The mean fluoroscopic time for the first 15 procedures was 10 s (standard deviation 4.5 s). The mean fluoroscopic time for the last 15 procedures was 4.2 s (standard deviation 1.2 s). No patellar tendon ruptures or bleeding complications were seen in the postoperative period. The course of fracture healing was not altered by this new percutaneous technique of pin insertion.

Adipocyte metabolism in adipocyte fatty acid binding protein knockout mice (aP2-/-) after short-term high-fat feeding: functional compensation by the keratinocyte [correction of keritinocyte] fatty acid binding protein.

Mice null for adipocyte fatty acid binding protein (AFABP) compensate by increasing expression of keratinocyte fatty acid binding protein (KFABP) (Hotamisligil et al. Science 274:1377-1379, 1996). In the present study, AFABP knockout (KO) and wild-type (WT) mice became equally obese on a high-fat diet, as judged by fat pad weights, adipocyte size, and body composition analysis. High-fat feeding led to moderate insulin resistance in both WT and AFABP knockout mice, as indicated by an approximately 2-fold increase in plasma insulin. However, in the high fat-fed mice, plasma glucose levels were approximately 15% lower in the AFABP-KO mice. Adipocytes isolated from AFABP-KO and WT mice fed high- or low-fat diets exhibited similar rates of basal and norepinephrine-stimulated lipolysis and insulin-stimulated rates of glucose conversion to fatty acids and glyceride-glycerol. However, basal glucose conversion to fatty acids was higher in adipocytes of AFABP-KO mice. Adipocyte tumor necrosis factor-alpha release was similarly increased by high-fat diet-induced obesity in both WT and AFABP-KO mice. As assessed by Western blot analysis, the level of KFABP protein in AFABP-KOs was approximately 40% of the level of AFABP in WT controls. The binding affinities of KFABP for long-chain fatty acids were 2- to 4-fold higher than those of AFABP, but the relative affinities for different fatty acids were similar. As for AFABP, the rate of fatty acid transfer from KFABP to model phospholipid vesicles was increased with acceptor membrane concentration and by inclusion of acidic phospholipids, indicating a similar mechanism of transfer. We conclude KFABP can functionally compensate for the absence of AFABP, resulting in no major alterations in adipocyte metabolism or fat accumulation in response to short-term feeding of high-fat diets that result in moderate hyperinsulinemia.

Stimulation of osteoclast differentiation in vitro by mouse oncostatin M, leukaemia inhibitory factor, cardiotrophin-1 and interleukin 6: synergy with dexamethasone.

The role of oncostatin M in bone metabolism is not clearly defined, and the actions of mouse oncostatin M (mOSM) on osteoclast development has not been previously determined. We therefore examined the ability of recombinant mOSM to stimulate osteoclast formation and activity using cocultures of murine calvaria and bone marrow cells, and compared the responses to other members of the interleukin 6 family of cytokines including mouse leukaemia inhibitory factor (LIF), cardiotrophin-1 (CT-1) and IL-6. Mouse OSM, LIF and CT-1 strongly induced the formation of tartrate resistant acid phosphatase positive (TRAP(+)) multinucleated cells (MNC) in a dose-dependent fashion. OSM, LIF or CT-1 also elevated the number and size of resorptive pits when cocultures were added to smooth cortical bone slices, indicating enhancement of osteoclast activity. The activity of OSM was reduced by indomethacin (10(-8)-10(-6) M), whereas addition of dexamethasone (DEX) at 10(-7)-10(-5) M synergistically enhanced OSM-induced numbers of TRAP(+)MNC. DEX (10(-7) M) costimulation also synergistically enhanced TRAP(+)cell numbers of LIF, and CT-1 treated cocultures. IL-6 had no activity alone, but further enhanced TRAP(+)cell formation in mOSM or DEX (10(-7) M) treated cocultures. When added to mouse calvarial osteoblast cultures, mOSM induced secretion of IL-6 protein and elevation of mRNA whereas LIF or CT-1 did not. IL-6 mRNA levels and protein secretion were reduced in osteoblasts by costimulation with DEX. These results show that mouse OSM, LIF and CT-1 induce osteoclast differentiation and activation, that DEX synergizes with each in this activity, and that mouse OSM induces responses in osteoblasts that are not shown by LIF or CT-1. Collectively these data suggest an important role of these cytokines in osteoporosis caused by high levels of corticosteroid.

New insights into the size and stoichiometry of the plasminogen activator inhibitor type-1.vitronectin complex.

Plasminogen activator inhibitor-type 1 (PAI-1) is the primary inhibitor of endogenous plasminogen activators that generate plasmin in the vicinity of a thrombus to initiate thrombolysis, or in the pericellular region of cells to facilitate migration and/or tissue remodeling. It has been shown that the physiologically relevant form of PAI-1 is in a complex with the abundant plasma glycoprotein, vitronectin. The interaction between vitronectin and PAI-1 is important for stabilizing the inhibitor in a reactive conformation. Although the complex is clearly significant, information is vague regarding the composition of the complex and consequences of its formation on the distribution and activity of vitronectin in vivo. Most studies have assumed a 1:1 interaction between the two proteins, but this has not been demonstrated experimentally and is a matter of some controversy since more than one PAI-1-binding site has been proposed within the sequence of vitronectin. To address this issue, competition studies using monoclonal antibodies specific for separate epitopes confirmed that the two distinct PAI-1-binding sites present on vitronectin can be occupied simultaneously. Analytical ultracentrifugation was used also for a rigorous analysis of the composition and sizes of complexes formed from purified vitronectin and PAI-1. The predominant associating species observed was high in molecular weight (M(r) approximately 320,000), demonstrating that self-association of vitronectin occurs upon interaction with PAI-1. Moreover, the size of this higher order complex indicates that two molecules of PAI-1 bind per vitronectin molecule. Binding of PAI-1 to vitronectin and association into higher order complexes is proposed to facilitate interaction with macromolecules on surfaces.

Type 1 plasminogen activator inhibitor binds to fibrin via vitronectin.

Type 1 plasminogen activator inhibitor (PAI-1), the primary inhibitor of tissue-type plasminogen activator (t-PA), circulates as a complex with the abundant plasma glycoprotein, vitronectin. This interaction stabilizes the inhibitor in its active conformation In this report, the effects of vitronectin on the interactions of PAI-1 with fibrin clots were studied. Confocal microscopic imaging of platelet-poor plasma clots reveals that essentially all fibrin-associated PAI-1 colocalizes with fibrin-bound vitronectin. Moreover, formation of platelet-poor plasma clots in the presence of polyclonal antibodies specific for vitronectin attenuated the inhibitory effects of PAI-1 on t-PA-mediated fibrinolysis. Addition of vitronectin during clot formation markedly potentiates PAI-1-mediated inhibition of lysis of (125)I-labeled fibrin clots by t-PA. This effect is dependent on direct binding interactions of vitronectin with fibrin. There is no significant effect of fibrin-associated vitronectin on fibrinolysis in the absence of PAI-1. The binding of PAI-1 to fibrin clots formed in the absence of vitronectin was characterized by a low affinity (K(d) approximately 3.5 micrometer) and rapid loss of PAI-1 inhibitory activity over time. In contrast, a high affinity and stabilization of PAI-1 activity characterized the cooperative binding of PAI-1 to fibrin formed in the presence of vitronectin. These findings indicate that plasma PAI-1.vitronectin complexes can be localized to the surface of fibrin clots; by this localization, they may modulate fibrinolysis and clot reorganization.

Reamed versus nonreamed intramedullary nailing of lower extremity long bone fractures: a systematic overview and meta-analysis.

OBJECTIVE: To determine the effect of reamed versus nonreamed intramedullary (IM) nailing of lower extremity long bone fractures on the rates of nonunion, implant failure, malunion, compartment syndrome, pulmonary embolus, and infection. DESIGN: Quantitative systematic review of prospective, randomized controlled trials. DATA IDENTIFICATION: MEDLINE and SCISEARCH computer searches provided lists of published randomized clinical trials from 1969 to 1998. Extensive hand searches of major orthopaedic journals, bibliographies of major orthopaedic texts, and personal files identified additional studies. STUDY SELECTION AND DATA EXTRACTION: Of 676 citations initially identified, sixty proved potentially eligible, of which four published and five unpublished randomized trials met all eligibility criteria. Each of three investigators assessed study quality and abstracted relevant data. RESULTS: The pooled relative risk of reamed versus nonreamed nails (nine trials, n = 646 patients) was 0.33 [95% confidence interval (CI), 0.16 to 0.68; p = 0.004]. The absolute risk difference in nonunion rates with reamed IM nailing was 7.0 percent (95% CI, 1 to 11 percent). Thus, one nonunion could be prevented for every fourteen patients treated with reamed IM nailing [number needed to treat (NNT) = 14.28]. The risk ratios for secondary outcome measures were: implant failure, 0.30 (95% CI, 0.16 to 0.58; p < 0.001); malunion, 1.06 (95% CI, 0.32 to 3.57); pulmonary embolus, 1.10 (95% CI, 0.26 to 4.76); compartment syndrome, 0.45 (95% CI, 0.13 to 1.56); and infection, 0.98 (95% CI, 0.21 to 4.76). Sensitivity analyses suggested that reported rates of nonunion and implant failure were higher in studies of lower quality. The type of long bone fractured (tibia or femur), the degree of soft tissue injury (open or closed), study quality, and whether a study was published or unpublished did not significantly alter the relative risk of nonunion between reamed and nonreamed IM nailing. CONCLUSIONS: There is evidence from a pooled analysis of randomized trials that reamed IM nailing of lower extremity long bone fractures significantly reduces rates of nonunion and implant failure in comparison with nonreamed nailing.

High and low pressure irrigation in contaminated wounds with exposed bone.

BACKGROUND: Irrigation and debridement are essential in the initial management of traumatic wounds. The relative efficicacy of low pressure irrigation compared with high pressure irrigation remains unclear. AIMS: The purpose of this study was to examine the time dependent efficacy of both high and low pressure lavage in removing adherent bacteria from traumatic wounds with exposed bone. METHODS: Using an in-vivo model, we created bilateral Staphylococcus aureus contaminated femoral wounds in 30 mice. The wounds were incubated for 1 to 10 hours and lavaged with either high (70 psi) or low pressure lavage (1-2 psi). The mean colony forming units of bacteria were compared between groups at each time point. RESULTS: High and low pressure lavage were effective in removing adherent bacteria from contaminated wounds up to 8 hours and 4 hours, respectively. High pressure lavage was more effective than low pressure at every time point. CONCLUSION: The efficacy of low pressure lavage in wounds with exposed bone is questionable when irrigation is delayed beyond 4 hours.