The impact of sedation on the quality of initial skeletal surveys performed for suspected physical abuse in children: a comparative two-centre audit.

BACKGROUND: The impact of sedation on the quality of initial skeletal surveys performed for suspected physical abuse in children is not known. OBJECTIVE: To assess whether sedation influenced the number of, reason for and effective dose of repeat radiographs obtained as part of initial skeletal surveys, and their mean examination times. MATERIALS AND METHODS: One hundred consecutive antemortem initial skeletal survey examinations performed for suspected physical abuse in children <2 years were retrieved from two tertiary paediatric hospitals: Centre 1, where sedation is not used for initial skeletal survey imaging; and Centre 2, where sedation is used routinely. RESULTS: In total, 4055 radiographic projections were performed, of which 93 (2.3%) were repeats. Comparing centres, there was a significant difference in the total number of repeats (P=0.001) and the number of repeats in children aged <12 months (P=0.008). Mean examination times were significantly shorter in unsedated children (P=0.005), even after outliers were excluded (P=0.002). There was no significant difference between the number of routine projections (P=0.587), incompletely imaged body parts (P=0.254), rotation/suboptimal positioning (P=0.527), repeats in children aged >12 months (P=0.089), routine projections in children aged <12 months (P=0.642) or >12 months (P=0.979) or the effective doses of repeats (P=0.286). CONCLUSION: There were fewer repeat projections in sedated children and those aged <12 months but examination times were significantly longer. There was no difference in the effective doses of repeated projections. The routine use of sedation is not supported when performing skeletal survey imaging if the primary considerations are reducing radiation dose and examination time.

Quantitative TMT-based proteomics revealing host, dietary and microbial proteins in bovine faeces including barley serpin Z4, a prominent component in the head of beer.

There has been little information about the proteome of bovine faeces or about the contribution to the faecal proteome of proteins from the host, the feed or the intestinal microbiome. Here, the bovine faecal proteome and the origin of its component proteins was assessed, while also determining the effect of treating barley, the major carbohydrate in the feed, with either ammonia (ATB) or sodium propionate (PTB) preservative. Healthy continental crossbreed steers were allocated to two groups and fed on either of the barley-based diets. Five faecal samples from each group were collected on Day 81 of the trial and analysed by quantitative proteomics using nLC-ESI-MS/MS after tandem mass tag labelling. In total, 281 bovine proteins, 199 barley proteins, 176 bacterial proteins and 190 archaeal proteins were identified in the faeces. Mucosal pentraxin, albumin and digestive enzymes were among bovine proteins identified. Serpin Z4 a protease inhibitor was the most abundant barley protein identified which is also found in barley-based beer, while numerous microbial proteins were identified, many originating bacteria from Clostridium, while Methanobrevibacter was the dominant archaeal genus. Thirty-nine proteins were differentially abundant between groups, the majority being more abundant in the PTB group compared to the ATB group. SIGNIFICANCE: Proteomic examination of faeces is becoming a valuable means to assess the health of the gastro-intestinal tract in several species, but knowledge on the proteins present in bovine faeces is limited. This investigation aimed to characterise the proteome of bovine faecal extracts in order to evaluate the potential for investigations of the proteome as a means to assess the health, disease and welfare of cattle in the future. The investigation was able to identify proteins in bovine faeces that had been (i) produced by the individual cattle, (ii) present in the barley-based feed eaten by the cattle or (iii) produced by bacteria and other microbes in the rumen or intestines. Bovine proteins identified included mucosal pentraxin, serum albumin and a variety of digestive enzymes. Barley proteins found in the faeces included serpin Z4, a protease inhibitor that is also found in beer having survived the brewing process. Bacterial and archaeal proteins in the faecal extracts were related to several pathways related to the metabolism of carbohydrates. The recognition of the range of proteins that can be identified in bovine faeces raises the possibility that non-invasive sample collection of this material could provide a novel diagnostic approach to cattle health and welfare.

Emergence of behavioural avoidance strategies of malaria vectors in areas of high LLIN coverage in Tanzania.

Despite significant reductions in malaria transmission across Africa since 2000, progress is stalling. This has been attributed to the development of insecticide resistance and behavioural adaptations in malaria vectors. Whilst insecticide resistance has been widely investigated, there is poorer understanding of the emergence, dynamics and impact of mosquito behavioural adaptations. We conducted a longitudinal investigation of malaria vector host choice over 3 years and resting behaviour over 4 years following a mass long-lasting insecticidal nets (LLINs) distribution in Tanzania. By pairing observations of mosquito ecology with environmental monitoring, we quantified longitudinal shifts in host-choice and resting behaviour that are consistent with adaptation to evade LLINs. The density of An. funestus s.l., declined significantly through time. In tandem, An. arabiensis and An. funestus s.l. exhibited an increased rate of outdoor relative to indoor resting; with An. arabiensis reducing the proportion of blood meals taken from humans in favour of cattle. By accounting for environmental variation, this study detected clear evidence of intra-specific shifts in mosquito behaviour that could be obscured in shorter-term or temporally-coarse surveys. This highlights the importance of mosquito behavioural adaptations to vector control, and the value of longer-term behavioural studies.

Analysing livestock network data for infectious disease control: an argument for routine data collection in emerging economies.

Livestock movements are an important mechanism of infectious disease transmission. Where these are well recorded, network analysis tools have been used to successfully identify system properties, highlight vulnerabilities to transmission, and inform targeted surveillance and control. Here we highlight the main uses of network properties in understanding livestock disease epidemiology and discuss statistical approaches to infer network characteristics from biased or fragmented datasets. We use a 'hurdle model' approach that predicts (i) the probability of movement and (ii) the number of livestock moved to generate synthetic 'complete' networks of movements between administrative wards, exploiting routinely collected government movement permit data from northern Tanzania. We demonstrate that this model captures a significant amount of the observed variation. Combining the cattle movement network with a spatial between-ward contact layer, we create a multiplex, over which we simulated the spread of 'fast' ( R0 = 3) and 'slow' ( R0 = 1.5) pathogens, and assess the effects of random versus targeted disease control interventions (vaccination and movement ban). The targeted interventions substantially outperform those randomly implemented for both fast and slow pathogens. Our findings provide motivation to encourage routine collection and centralization of movement data to construct representative networks. This article is part of the theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control'. This theme issue is linked with the earlier issue 'Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes'.

Statistical modelling studies examining the dimensional structure of psychopathology experienced by adults with intellectual disabilities: Systematic review.

Diagnosing mental ill-health using categorical classification systems has limited validity for clinical practice and research. Dimensions of psychopathology have greater validity than categorical diagnoses in the general population, but dimensional models have not had a significant impact on our understanding of mental ill-health and problem behaviours experienced by adults with intellectual disabilities. This paper systematically reviews the methods and findings from intellectual disabilities studies that use statistical methods to identify dimensions of psychopathology from data collected using structured assessments of psychopathology. The PRISMA framework for systematic review was used to identify studies for inclusion. Study methods were compared to best-practice guidelines on the use of exploratory factor analysis. Data from the 20 studies included suggest that it is possible to use statistical methods to model dimensions of psychopathology experienced by adults with intellectual disabilities. However, none of the studies used methods recommended for the analysis of non-continuous psychopathology data and all 20 studies used statistical methods that produce unstable results that lack reliability. Statistical modelling is a promising methodology to improve our understanding of mental ill-health experienced by adults with intellectual disabilities but future studies should use robust statistical methods to build on the existing evidence base.

Plastic debris in great skua (Stercorarius skua) pellets corresponds to seabird prey species.

Plastic is a common item in marine environments. Studies assessing seabird ingestion of plastics have focused on species that ingest plastics mistaken for prey items. Few studies have examined a scavenger and predatory species that are likely to ingest plastics indirectly through their prey items, such as the great skua (Stercorarius skua). We examined 1034 regurgitated pellets from a great skua colony in the Faroe Islands for plastics and found approximately 6% contained plastics. Pellets containing remains of Northern fulmars (Fulmarus glacialis) had the highest prevalence of plastic. Our findings support previous work showing that Northern fulmars have higher loads of plastics than other sympatric species. This study demonstrates that marine plastic debris is transferred from surface feeding seabird species to predatory great skuas. Examination of plastic ingestion in species that do not ingest plastics directly can provide insights into how plastic particles transfer vertically within the food web.

Comparative evaluation of the Sticky-Resting-Box-Trap, the standardised resting-bucket-trap and indoor aspiration for sampling malaria vectors.

BACKGROUND: Understanding mosquito resting behaviour is important for the control of vector-borne diseases, but this remains a challenge because of the paucity of efficient sampling tools. We evaluated two novel sampling methods in the field: the Sticky Resting Box (SRB) and the Resting Bucket trap (RBu) to test their efficiency for sampling malaria vectors resting outdoors and inside houses in rural Tanzania. The performance of RBu and SRB was compared outdoors, while indoors SRB were compared with the Back Pack Aspiration method (BP). Trapping was conducted within 4 villages in the Kilombero Valley, Tanzania over 14 nights. On each night, the performance for collecting Anopheles vectors and Culicinae was compared in 4 households by SRB and RBu outdoors and by SRB or fixed-time Back Pack aspirator in 2 of the 4 focal households indoors. FINDINGS: A total of 619 Anopheles gambiae s.l., 224 Anopheles funestus s.l. and 1737 Culicinae mosquitoes were captured. The mean abundance of An. arabiensis and An. funestus s.l. collected with SRB traps inside and outdoors was significantly lower than with BP or RBu. The SRB however, outperformed BP aspiration for collection of Culicinae indoors. CONCLUSIONS: Of the methods trialled indoors (BP and SRB), BP was the most effective, whilst outdoors RBu performed much better than SRB. However, as SRB can passively sample mosquitoes over a week they could provide an alternative to the RBu where daily monitoring is not possible.

Music during interventional radiological procedures, effect on sedation, pain and anxiety: a randomised controlled trial.

OBJECTIVE: To assess the effects of playing patient-selected music during interventional procedures on (1) the doses of sedation and analgesia and (2) anxiety levels. METHODS: Patients undergoing interventional radiological procedures were randomised to either the intervention (music) or the control (no music) group. Patients in the intervention group had music of their choice played via headphones during the procedure. The primary outcomes were reductions in the doses of drugs for sedation (midazolam) and analgesia (fentanyl). Anxiety levels were assessed both before and after the procedure using the validated State Anxiety Inventory. Mean pulse rate and average of mean blood pressures were also recorded before and during the procedures as surrogate indicators of anxiety levels. RESULTS: 100 patients were randomised in a 1:1 ratio. There were 58 males and 42 females, with a mean age of 58 years. Sedation was required in 21 (42%) patients in the music group compared with 30 (60%) patients in the control group (p=0.046). The mean [standard deviation (SD)] midazolam dose was 2.1 mg (2.3 mg) in the control group and 1.3 mg (2.2 mg) in the music group (p=0.027). The mean (SD) fentanyl dose was 29 mg (40 mg) in the control group and 18 mg (34 mg) in the music group (p=0.055). There was no significant effect of music on the change from baseline in anxiety levels (p=0.74), pulse rate (p=0.56) or blood pressure (p=0.34). CONCLUSION: Sedation requirements are significantly reduced by playing self-selected music to the patient during interventional radiology procedures. By lowering sedation during interventional radiology, music makes the procedure safer. It also contributes favourably to the overall patient experience.

Cardiovascular benefits in moderate increases of blood and plasma viscosity surpass those associated with lowering viscosity: Experimental and clinical evidence.

Decreasing blood viscosity has been proposed since the advent of hemodilution as a means for increasing perfusion in many pathological conditions, and increased plasma viscosity is associated with the presence of pathological conditions. However, experimental studies show that microvascular functions as represented by functional capillary density in conditions of significantly decreased viscosity is impaired, a problem corrected by increasing plasma and blood viscosity. Blood viscosity, primarily dependent on hematocrit (Hct) is a determinant of peripheral vascular resistance, and therefore blood pressure. In the healthy population Hct presents a variability, which is not reflected by the variability of blood pressure. This is due to a regulatory process at the level of the endothelium, whereby the increase of Hct (and therefore blood viscosity) leads to increased shear stress and the production of the vasodilator nitric oxide (NO), a finding supported by experimental studies showing that the acute increase of Hct lowers blood pressure. Studies that in the healthy population show that blood pressure and Hct have a weak positive correlation. However, when the effect of blood viscosity is factored out, blood pressure and Hct are negatively and significantly correlated, indicating that as blood viscosity increases, the circulation dilates. Conversely, lower Hct and blood viscosity conditions lead to a constricted circulation, associated with a condition of decreased NO bioavailability, and therefore a pro-inflammatory condition.

Bayesian paternity analysis and mating patterns in a parasitic nematode, Trichostrongylus tenuis.

Mating behaviour is a fundamental aspect of the evolutionary ecology of sexually reproducing species, but one that has been under-researched in parasitic nematodes. We analysed mating behaviour in the parasitic nematode Trichostrongylus tenuis by performing a paternity analysis in a population from a single red grouse host. Paternity of the 150 larval offspring of 25 mothers (sampled from one of the two host caeca) was assigned among 294 candidate fathers (sampled from both caeca). Each candidate father's probability of paternity of each offspring was estimated from 10-locus microsatellite genotypes. Seventy-six (51%) offspring were assigned a father with a probability of >0.8, and the estimated number of unsampled males was 136 (95% credible interval (CI) 77-219). The probability of a male from one caecum fathering an offspring in the other caecum was estimated as 0.024 (95% CI 0.003-0.077), indicating that the junction of the caeca is a strong barrier to dispersal. Levels of promiscuity (defined as the probability of two of an adult's offspring sharing only one parent) were high for both sexes. Variance in male reproductive success was moderately high, possibly because of a combination of random mating and high variance in post-copulatory reproductive success. These results provide the first data on individual mating behaviour among parasitic nematodes.

Application of Chimera grid to modelling cell motion and aggregation in a narrow tube.

A computational scheme using the Chimera grid method is presented for simulation of three-dimensional motion and aggregation of two red blood cells (RBCs) in a narrow tube. The cells are modelled as rigid ellipsoidal particles; the computational scheme is applicable to deformable fluid-filled particles. Attractive energy between two RBCs is modelled by a depletion interaction theory and used for simulating aggregation of two cells. Through the simulation, we show that the Chimera grid method is applicable to the simulation of three-dimensional motion and aggregation of multiple RBCs in a microvessel and microvascular network.

Effects of erythrocyte aggregation and venous network geometry on red blood cell axial migration.

Axial migration of red blood cells in small glass tubes can cause blood viscosity to be effectively independent of shear rate. However, this phase separation may not occur to the same degree in the venous network due to infusion of cells and aggregates at branch points. To investigate this hypothesis, we followed trajectories of fluorescently labeled red blood cells in the venular network of the rat spinotrapezius muscle at normal and reduced flow with and without red blood cell aggregation. Cells traveling near the wall of an unbranched venular segment migrated approximately 1% of the longitudinal path length without aggregation and migrated slightly more with aggregation. Venular segment length between branch points averaged three to five times the diameter. Cells in the main vessel were shifted centrally by up to 20% of diameter at branch points, reducing the migration rate of cells near the opposite wall to <1% even in the presence of aggregation. We conclude that formation of a cell-free marginal layer in the venular network is attenuated due to the time dependence of axial migration and the frequent branching of the network.

Erythrocyte margination and sedimentation in skeletal muscle venules.

Previous studies in skeletal muscle of the dog and cat have shown that venous vascular resistance changes inversely with blood flow and may be due mainly to red blood cell aggregation, a phenomenon present in these species. To determine whether red blood cell axial migration and sedimentation contribute to this effect, we viewed either vertically or horizontally oriented venules of the rat spinotrapezius muscle with a horizontally oriented microscope during acute arterial pressure reduction. With normal (nonaggregating) rat blood, reduction of arterial pressure did not significantly change the relative diameter of the red blood cell column with respect to the venular wall. After induction of red blood cell aggregation in the rat by infusion of Dextran 500, red blood cell column diameter decreased up to 35% at low pseudoshear rates (below approximately 5 s(-1)); the magnitude was independent of venular orientation. In vertically oriented venules, the plasma layer was symmetrical, whereas in horizontally oriented venules, the plasma layer formed near the upper wall. We conclude that, although red blood cell axial migration and sedimentation develop in vivo, they occur only for larger flow reductions than are needed to elicit changes in venous resistance.

Clearance of fungal burden during treatment of disseminated histoplasmosis with liposomal amphotericin B versus itraconazole.

Animal studies have shown that fungal burden correlates with survival during treatment with new antifungal therapies for histoplasmosis. The purpose of this report is to compare the clearance of fungal burden in patients with histoplasmosis treated with liposomal amphotericin B versus itraconazole. In two separate closed clinical trials that evaluated the efficacy of liposomal amphotericin B and itraconazole treatment of disseminated histoplasmosis in patients with AIDS, blood was cultured for fungus and blood and urine were tested for Histoplasma antigen. The clinical response rates were similar; 86% with liposomal amphotericin B (n = 51) versus 85% with itraconazole (n = 59). Of the patients with positive blood cultures at enrollment, after 2 weeks of therapy cultures were negative in over 85% of the liposomal amphotericin B group versus 53% of the itraconazole group (P = 0.0008). Furthermore, after 2 weeks, median antigen levels in serum fell by 1.6 U in the liposomal amphotericin B group versus 0.1 U in the itraconazole group (P = 0.02), and those in urine fell by 2.1 U in the liposomal amphotericin B group and 0.2 U in the itraconazole group (P = 0.0005). The more rapid clearance of fungemia supports the use of liposomal amphotericin B rather than itraconazole for initial treatment of moderately severe or severe histoplasmosis.

Protection to +12 Gz.

BACKGROUND: The U.S. Air Force has developed +Gz-protective equipment that will provide most pilots protection to +9 Gz with minimal-to-no straining. This equipment includes a pressure breathing system called COMBAT EDGE (CE), which is currently operational, and the Advanced Technology Anti-G Suit (ATAGS), which is not yet operational. For future high-performance aircraft design it is important to know the upper limit of various protective equipment and techniques. METHODS: Six subjects were randomly exposed to a 12-cell matrix composed of +Gz and the following combinations of protective equipment at three seat-back angles (13 degrees, 30 degrees and 55 degrees from the vertical): 1) the standard CSU-13B/P anti-G suit (STD); 2) the STD suit with CE; 3) the ATAGS; and 4) the ATAGS with CE. Relaxed, followed by straining +Gz tolerance was determined using 15-s rapid onset runs to a maximum of +12 Gz. A comprehensive battery of baseline and post-exposure medical surveillance studies was performed to evaluate the medical consequences of these high +Gz exposures. RESULTS: All 6 subjects were able to achieve +12 Gz with various combinations of +Gz-protective equipment, seat-back angle, and various amounts of straining, from none to maximum. When the data were collapsed over all protective equipment there was a significant (p < 0.05) seat effect. Relaxed tolerance to ROR increased with seat-back angle from 13 degrees to 30 degrees to 55 degrees. There was also a significant protective equipment effect when the data were collapsed over all seat-back angles. CONCLUSIONS: These data confirm that effortless protection to +9 Gz is available using ATAGS/CE with the 13 degree and 30 degree seat-back angle (F-15, F-16 and F-22) and to +10.5 Gz with a 55 degree seat-back angle. Moreover, with ATAGS/CE, and a moderate degree of straining, +12 Gz is definitely achievable at 55 degrees, even with reduced anti-G suit pressure at 55 degrees. With additional straining +12 GC is also achievable at the 13 degree and 30 degree seat-back angles.

Rheological effects of red blood cell aggregation in the venous network: a review of recent studies.

It has long been recognized that understanding the rheological properties of blood is essential to a full understanding of the function of the circulatory system. Given the difficulty of obtaining carefully controlled measurements in vivo, most of our current concepts of the flow behavior of blood in vivo are based on its properties in vitro. Studies of blood rheology in rotational and tube viscometers have defined the basic properties of blood and pointed to certain features that may be especially significant for understanding in vivo function. At the same time, differences between in vivo and in vitro systems combined with the complex rheological properties of blood make it difficult to predict in vivo blood rheology from in vitro studies. We have investigated certain flow properties of blood in vivo, using the venular network of skeletal muscle as our model system. In the presence of red blood cell aggregation, venous velocity profiles become blunted from the parabolic as in Poiseuille flow, as pseudo-shear rate (= mean fluid velocity/vessel diameter) is decreased from approximately 100 s(-1) to 5 s(-1). At control flow rates, the short distance between venular junctions does not appear to permit significant axial migration and red cell depletion of the peripheral fluid layer before additional red cells and aggregates are infused from a feeding tributary. Formation of a cell-free plasma layer at the vessel wall and sedimentation in vivo are evident only at very low pseudo-shear rates (<5 s(-1)). These findings may explain in large part observations in whole organs of increased venous resistance with reduction of blood flow.

Effect of erythrocyte aggregation on velocity profiles in venules.

A recent whole organ study in cat skeletal muscle showed that the increase in venous resistance seen at reduced arterial pressures is nearly abolished when the muscle is perfused with a nonaggregating red blood cell suspension. To explore a possible underlying mechanism, we tested the hypothesis that red blood cell aggregation alters flow patterns in vivo and leads to blunted red blood cell velocity profiles at reduced shear rates. With the use of fluorescently labeled red blood cells in tracer quantities and a video system equipped with a gated image intensifier, we obtained velocity profiles in venous microvessels (45-75 microm) of rat spinotrapezius muscle at centerline velocities between 0.3 and 14 mm/s (pseudoshear rates 3-120 s(-1)) under normal (nonaggregating) conditions and after induction of red blood cell aggregation with Dextran 500. Profiles are nearly parabolic (Poiseuille flow) over this flow rate range in the absence of aggregation. When aggregation is present, profiles are parabolic at high shear rates and become significantly blunted at pseudoshear rates of 40 s(-1) and below. These results indicate a possible mechanism for increased venous resistance at reduced flows.

The role of tissue engineering.

Tissue engineering is expected to have a great impact on wound repair. Tissue-engineering techniques bring a new element of rational design and development into therapeutic medicine. Increasing the understanding of the biology of wound repair will accelerate the improvement of patient care, and the knowledge of basic biologic processes will be applied to the development of new products. Tissue-engineered skin will be reviewed and directions for new products will be illustrated. In the future, tissue engineering is likely to continue to yield products that are rationally designed, robotically manufactured, and increasingly customized to fit patient needs.

Computational fluid dynamic studies of leukocyte adhesion effects on non-Newtonian blood flow through microvessels.

The study of the effect of leukocyte adhesion on blood flow in small vessels is of primary interest to understand the resistance changes in venular microcirculation. Available computational fluid dynamic studies provide information on the effect of leukocyte adhesion when blood is considered as a homogeneous Newtonian fluid. In the present work we aim to understand the effect of leukocyte adhesion on the non-Newtonian Casson fluid flow of blood in small venules; the Casson model represents the effect of red blood cell aggregation. In our model the blood vessel is considered as a circular cylinder and the leukocyte is considered as a truncated spherical protrusion in the inner side of the blood vessel. The cases of single leukocyte adhesion and leukocyte pairs in positions aligned along the same side, and opposite sides of the vessel wall are considered. The Casson fluid parameters are chosen for cat blood and human blood and comparisons are made for the effects of leukocyte adhesion in both species. Numerical simulations demonstrated that for a Casson fluid with hematocrit of 0.4 and flow rate Q = 0.072 nl/s, a single leukocyte increases flow resistance by 5% in a 32 microns diameter and 100 microns long vessel. For a smaller vessel of 18 microns, the flow resistance increases by 15%.