Cervical spine clearance in adults following blunt trauma: a national survey across major trauma centres in England.

AIM: To assess current practice in cervical spine clearance across major trauma centres in England and review current guidelines. MATERIALS AND METHODS: An electronic survey was sent to lead trauma clinicians at 22 major trauma centres in England. This assessed the clinical decision tools used, the choice of initial imaging technique, and the methods used to clear the cervical spine in alert and obtunded patients without focal neurology, and where initial imaging was normal. British Orthopaedic Association Standards for Trauma (BOAST) 2 and Eastern Association for Surgery for Trauma (EAST) guidelines were used as standards. RESULTS: Eighteen out of the 22 (82%) centres responded by completing the survey. Most (71%) centres used the Canadian C-Spine Rule for clearing the cervical spine clinically. Seventy-two percent of centres preferred computed tomography (CT) as the first-line imaging technique, the choice based on age of patient and mechanism of injury. If the initial CT imaging was normal, magnetic resonance imaging (MRI) was performed in 52% of centres to clear the cervical spine, with half of these centres stating that they would discuss further imaging with a radiologist first. The practice across centres was highly variable for the obtunded patient, with most centres preferring continuing immobilisation or MRI to clear the cervical spine, with a small minority removing spinal precautions when a high-quality multidetector CT was normal. CONCLUSION: Multidetector CT is the preferred initial imaging technique across most major trauma centres in England when blunt cervical spine trauma is suspected. There is widespread reliance on MRI to clear the cervical spine in both alert and obtunded patients, if initial CT imaging is normal and there is no focal neurology on clinical assessment. This calls for greater awareness of the reliability of a high-quality normal multidetector CT examination in clearing the cervical spine in the absence of focal neurology.

Blunt cervical spine injury in adult polytrauma: incidence, injury patterns and predictors of significant ligament injury on CT.

AIM: To describe the pattern of cervical spine fractures in adult major trauma and identify computed tomography (CT) parameters that can predict significant ligament injury when fractures are absent; to define the normal range for parameters used; and identify common variations due to position of cervical immobilisation in a trauma patient. MATERIALS AND METHODS: In this retrospective study all polytrauma patients imaged using multidetector CT over a period of 5 years were identified. Patients with cervical spine fracture and suspected ligament injury in the absence of fracture were collated based on the polytrauma CT report. Predictors of ligament injury were defined based on published historical data on plain radiographs and posterior paraspinal fat pad assessment at CT. These parameters were recorded for each study with comparison to subsequent magnetic resonance imaging (MRI) as the reference standard. RESULTS: Significant ligament injury on MRI was detected at the craniocervical junction, when CT showed a basion dens interval of >10 mm, widened incongruous C0/C1 facet joint space of >3 mm, and widened C1/2 facet joint space of >6 mm. In the subaxial cervical spine, facet subluxation >50% and obscured posterior paraspinal fat pad were the only reliable predictors of ligament injury, as confirmed on subsequent MRI. CONCLUSION: When fractures are absent, signs of significant ligament injury on CT at the craniocervical junction were increased basion dens interval and widened facet joints. In the subaxial cervical spine, >50% subluxation of a facet joint and obscured posterior paraspinal fat pad are indicators of significant ligament injury.

Long-term quality-of-life outcomes in children undergoing adenotonsillectomy for obstructive sleep apnoea: a longitudinal study.

OBJECTIVES: To assess a cohort of patients who underwent adenotonsillectomy for obstructive sleep apnoea, 4 years after surgery for evidence of continued and long-term improvement in quality of life. We also sought to compare our results to Child Health Questionnaire scores obtained from our previous study. We also compared our data with a healthy UK children population from normative data available. DESIGN: Longitudinal study. SETTINGS: University Hospital Tertiary Referral Centre. PARTICIPANTS: A 4-year follow-up study of 37 children who underwent adenotonsillectomy for obstructive sleep apnoea confirmed on polysomnography. There were 19 boys and 18 girls from our initial cohort. The primary caregiver completed the validated Child Health Questionnaire Parental Form version-28, 4 years after initial surgery. Our control group consist of 221 healthy children aged 6-18 that were included as 'normal' controls in a study looking at children with juvenile arthritis. The children were defined as healthy by a physician and/or after declaration by the parent. MAIN OUTCOME MEASURE: Child Health Questionnaire Parental Form version-28 scores. RESULTS: A total of 33 patients (89%) from our initial cohort were contacted. The mean age was 10.6 (median, 11; range, 5-16). When compared with results obtained 3 months postoperatively, the mean scores were higher in five domains and were statistically significant in three subscales (Role Limitations P < 0.00001; Bodily Pain P < 0.002; and Global Health P < 0.02). There was a significant deterioration in Behaviour subscale (P < 0.0007) in spite of surgery. Compared with controls, 4-year follow-up scores were higher in five domains with the Global Health domain (P < 0.0004) being statistically significant. When the 4-year follow-up scores were compared with preoperative values, these were higher in all 13 domains with statistically significant improvements in nine domains, indicating that improvements had persisted 4 years after surgery. At 4 years, however, the means scores in many domains remain lower when compared with controls. CONCLUSION: Quality-of-life data are an important measure when deciding on a specific clinical intervention. In the short term, quality-of-life measures have been shown to improve after adenotonsillectomy for obstructive sleep apnoea. Our study demonstrates that the benefits of surgery are still persistent and the children continue to improve in the long term.

Recent advances in superior semicircular canal dehiscence syndrome.

OBJECTIVE: This study aimed to review the current advances in superior semicircular canal dehiscence syndrome and to ascertain its aetiology, whether dehiscence size correlates with symptoms, signs and investigation results, the best investigations, and its surgical management. METHODS: A literature search using the key words 'superior semicircular canal dehiscence' was performed using the Allied and Complementary Medicine Database and the Embase, Health Management Information Consortium, Medline, PsycINFO, British Nursing Index, Cinahl and Health Business Elite databases for the period January 2009 to May 2014. Systematic reviews, meta-analyses, randomised controlled trials, prospective and retrospective case series, case reports, and observational studies were included. RESULTS: Of the 205 papers identified, 35 were considered relevant. CONCLUSION: The aetiology of superior semicircular canal dehiscence syndrome is unclear. Dehiscence size significantly affects the air-bone gap and ocular vestibular evoked myogenic potential thresholds. Computed tomography evaluation has a high false positive rate. The middle cranial fossa approach is the surgical standard for treating this syndrome; however, the transmastoid approach is gaining popularity.

ECTOMYCORRHIZAL VS ENDOMYCORRHIZAL FUNGI WITHIN THE SAME ROOT SYSTEM.

Vesicular-arbuscular (VA) mycorrhizal fungi and ectomycorrhizal fungi were observed together in the same root system, and even within the same root apices, of seedlings of Eucalyptus dumosa A. Cunn. ex Schau. On a population basis, there was a succession of two overlapping mycorrhizal epidemics-VA mycorrhizas followed by ectomycorrhizas. This succession was interpreted as follows. Early build-up of VA mycorrhizas was related to initial higher inoculum potential of that fungus and to rapidity of colonization of individual roots. The ectomycorrhizal fungus was more successful later in achieving secondary infections by hyphal spread and in colonization of lateral root branches. The ectomycorrhizal fungus had no difficulty infecting pre-existing VA mycorrhizas, but the ectomycorrhizal sheath provided a barrier to subsequent VA mycorrhizal infections. While the proportion of VA mycorrhizas to ectomycorrhizas changed between two and five months, the overall proportion of mycorrhizal roots remained constant, suggesting that there could be competition between the different fungi for limiting substrate.

Demographic changes and the development of competition in a native Australian eucalypt forest invaded by exotic pines.

Data from the second half of a 14-year study of a eucalypt dry sclerophyll forest invaded by Pinus radiata D. Don shows further progress in the development of a mixed eucalypt-pine stand. Earlier (Chilvers and Burdon 1983) it was clear that pines invading from an adjacent commercial plantation were starting to contribute their own progeny to the mixed stand. Initially the recruitment of established pines (> 1 m high) from these seedlings was very slow. However, since 1984, increasing numbers of seedlings have survived beyond their first year, suggesting the possibility of another wave of successful establishment in the near future. The established fraction of the pine population continued to grow rapidly and incurred no mortality. Many of these plants have now emerged through the top of the eucalypt canopy. In contrast, both juvenile and adult eucalypt numbers continued to decline. Despite these demographic and visual changes, comparative analysis of the growth of established pines over two consecutive 7-year periods (1974-1981; 1981-1988) showed that competition between neighbouring plants, especially pines, is beginning to affect individual growth rates. Growth rates of pines having other pines as nearest neighbours declined 40% between 1974-1981 and 1981-1988, while that of pines with eucalypts as nearest neighbours fell by 28%. In pine-pine nearest neighbour (NN) pairs, growth rates were significantly affected by the size (diameter) of the nearest neighbour. In pine-eucalypt NN pairs growth rates of the pines were not affected by the size of the eucalypt, but these were significantly negatively correlated with the inverse of the distance to the eucalypt. More broad-based assessment of 43 pines showed a significant relationship between their growth rates and the summed competitive effect of other pines within a 5-m radius. No such relationship was found between growth rate and the summed competitive effect of eucalypts in the 5-m zone.

Further studies on a native Australian eucalypt forest invaded by exotic pines.

Pinus radiata is spreading from plantations into some types of native eucalypt forest. A broad transect through one heavily invaded site was mapped in 1974 and re-examined after intervals of time. In 1977 the adjacent pine plantation was clear-felled for commercial purposes. By 1981 it was clear that the pines that had already invaded the eucalypt forest were contributing their own progeny to the mixed stand. However, the rate of recruitment is slow due to high seedling mortality. Comparative measurements have shown that during the period 1974-1981 the growth rate of pines established among the eucalypts was approximately ten times greater than that of the native trees.

Controlled environment experiments on epidemics of barley mildew in different density host stands.

Controlled environment experiments on small epidemics of powdery mildew of barley, an air-borne disease caused by Erysiphe graminis f.sp. hordei, indicated that there was a direct linear relationship between host density and the rate of increase of disease within populations. Under the particular experimental conditions used, the overall infection rate was almost doubled (from 0.39 to 0.75 per unit per day) following an increase in density from 31 to 115 host units per m2. In separate experiments these overall epidemic rates were partitioned into two separate components related to inoculum transmission between plants and inoculum transmission within plants.

The effect of clumped planting patterns on epidemics of damping-off disease in cress seedlings.

Environmentally controlled experiments on damping-off disease of garden cress (Lepidium sativum) caused by Pythium irregulare were used to study the effect of clumped planting patterns upon epidemic rates. In clumped stands of seedlings the rate of multiplication of disease was, in general, slower than in unclumped, evenly spaced stands of the same overall density. When the number of clumps per unit area was varied, but the proportion of the total area occupied by clumps kept constant, there was no significant change in the rate of linear advance of the disease between different treatments, but the multiplication rate in randomly inoculated plots was higher at 100 clumps/m2 than 200 clumps/m2 due to an unexpected interaction between the multiplication rate and the distribution of primary disease foci. When the area occupied by clumps was varied, but the number of clumps per unit area and the overall plant density were kept constant, both the multiplication rate and the rate of linear advance of the disease were significantly reduced in the stands with the most condensed clumps.

Controlled environment experiments on epidemic rates of barley mildew in different mixtures of barley and wheat.

Controlled environment experiments on small epidemics of powdery mildew in mixtures of barley and wheat indicated that there was a relationship between the density of susceptible host units in the mixture and the rate of increase of disease within the stand best described by the equation: -r m =r s +clog e m; where r m and r s are epidemic rates in a mixture and a susceptible monoculture of the same overall stand density, m is the proportion of host plants in the mixture, and c is a constant. By the use of appropriate controls, it was shown that most of the reduction in epidemic rates in mixtures was attributable to the reduction in density of susceptible host units. Interception of air-borne inoculum by immune plants played a relatively minor role, although extrapolation of the results suggests that this factor might become significant if there was a sufficiently high proportion of immune to susceptible plants present.

Preliminary studies on a native Australian eucalypt forest invaded by exotic pines.

In some parts of Australia, the exotic tree species Pinus radiata is invading native eucalypt forests from adjacent plantations. At one site, measurements have been made in order to determine the dispersal gradient and rate of population increase of the self-sown pines. From these, it is evident that, barring further human interference, a new type of mixed forest community will develop.

Molecular origins of acetan solution properties.

Acetan is a branched acidic heteropolysaccharide secreted by Acetobacter xylinum. X-ray diffraction studies of oriented fibres suggest non-crystalline helices with fivefold symmetry and a pitch of 4.8 nm. Optical rotation and circular dichroism studies are consistent with the retention of the helical structure in solution and a helix-coil transition upon heating and cooling. Aqueous solutions yield high 'low shear rate' viscosity and shear-thin upon shearing.