Labile assembly of a tardigrade protein induces biostasis.

Tardigrades are microscopic animals that survive desiccation by inducing biostasis. To survive drying tardigrades rely on intrinsically disordered CAHS proteins, which also function to prevent perturbations induced by drying in vitro and in heterologous systems. CAHS proteins have been shown to form gels both in vitro and in vivo, which has been speculated to be linked to their protective capacity. However, the sequence features and mechanisms underlying gel formation and the necessity of gelation for protection have not been demonstrated. Here we report a mechanism of fibrillization and gelation for CAHS D similar to that of intermediate filament assembly. We show that in vitro, gelation restricts molecular motion, immobilizing and protecting labile material from the harmful effects of drying. In vivo, we observe that CAHS D forms fibrillar networks during osmotic stress. Fibrillar networking of CAHS D improves survival of osmotically shocked cells. We observe two emergent properties associated with fibrillization; (i) prevention of cell volume change and (ii) reduction of metabolic activity during osmotic shock. We find that there is no significant correlation between maintenance of cell volume and survival, while there is a significant correlation between reduced metabolism and survival. Importantly, CAHS D's fibrillar network formation is reversible and metabolic rates return to control levels after CAHS fibers are resolved. This work provides insights into how tardigrades induce reversible biostasis through the self-assembly of labile CAHS gels.

A pilot randomised control trial of the efficacy of stability-based training with visualisation for people with chronic ankle instability.

Chronic ankle instability (CAI) is associated with recurring symptoms that inhibit daily activity. Stability-based rehabilitative training is recommended for CAI. Visualisation (VIS) produces real-time feedback using motion capture and virtual reality. This pilot study aimed to determine the feasibility, adherence, safety, and efficacy of incorporating VIS into stability training for people with CAI. Efficacy was examined through effect of VIS training on dynamic stability, perception of stability, and rehabilitative experience. Individuals with CAI completed a 4-week stability-based training programme with VIS, or without visualisation (NO-VIS). Participants completed the Star Excursion Balance Test (SEBT) and Cumberland Ankle Instability Tool (CAIT) prior to, and after training. Enjoyment of training was recorded using the Physical Activity Enjoyment Scale (PACES-8). Of 17 participants (VIS = 10, NO-VIS = 7), there were 2 drop outs (VIS = 1, NO-VIS = 1). No adverse events were reported, and participant drop-out was due to injury unrelated to the study. The VIS group showed a significantly greater increase in average SEBT reach distance (d = 1.7, p = 0.02). No significant differences were reported for the CAIT or PACES-8. This study supports the feasibility and safety of stability-based training with VIS in those with CAI. The enhanced performance outcome on the SEBT suggests VIS may enhance stability-based training.

Diamond and methane formation from the chemical decomposition of polyethylene at high pressures and temperatures.

Polyethylene (C2H4)n was compressed to pressures between 10 and 30 GPa in a diamond anvil cell (DAC) and laser heated above 2500 K for approximately one second. This resulted in the chemical decomposition of the polymer into carbon and hydrocarbon reaction products. After quenching to ambient temperature, the decomposition products were measured in the DAC at pressures ranging from ambient to 29 GPa using a combination of x-ray diffraction (XRD) and small angle x-ray scattering (SAXS). XRD identified cubic diamond and methane as the predominant product species with their pressure-volume relationships exhibiting strong correlations to the diamond and methane equations of state. Length scales associated with the diamond products, obtained from SAXS measurements, indicate the formation of nanodiamonds with a radius of gyration between 12 and 35 nm consistent with 32-90 nm diameter spherical particles. These results are in good agreement with the predicted product composition under thermodynamic and chemical equilibrium.

Gait stability in response to platform, belt, and sensory perturbations in young and older adults.

Perturbation-based gait assessment has been used to quantify gait stability in older adults. However, knowledge on which perturbation type is most suitable to identify poor gait stability is lacking. We evaluated the effects of ipsi- and contra-lateral sway, belt acceleration and deceleration, and visual and auditory perturbations on medio-lateral (ML) and anterior-posterior (AP) margins of stability (MoS) in young and older adults. We aimed to evaluate (1) which perturbation type disturbed the gait pattern substantially, (2) how participants recovered, and (3) whether recovery responses could discriminate between young and older adults. Nine young (25.1 ± 3.4 years) and nine older (70.1 ± 7.6 years) adults walked on the CAREN Extended (Motek BV, The Netherlands). The perturbation effect was quantified by deviation in MoS over six post-perturbation steps compared to baseline walking. Contra-lateral sway and deceleration perturbations resulted in the largest ML (1.9-4 times larger than other types) and AP (1.6-5.6 times larger than other types) perturbation effects, respectively. After both perturbation types, participants increased MoS by taking wider, shorter, and faster steps. No differences between young and older adults were found. We suggest to evaluate the potential of using contra-lateral sway and deceleration perturbations for fall risk identification by including both healthy and frail older adults. Graphical abstract Margins of stability during steady state (left) and perturbed (right) gait to quantify reactive gait stability in response to various perturbation types in young and older adults.

Dental participation in geriatric interprofessional education courses: A systematic review.

INTRODUCTION: Although the interdisciplinary management of the ageing individual is highly stressed, there is limited information on the outcomes of interprofessional education (IPE) activities of dental students in geriatrics. This systematic review aimed to identify studies with dentists participating in formal IPE courses in geriatrics and assess the outcomes reported. MATERIAL AND METHODS: Electronic databases (PubMed, EMBASE, CINAHL and Scopus), reference lists from relevant studies and cited papers were investigated. The inclusion criteria were as follows: about formal interactive learning; learners from at least 2 disciplines; including dentists; related to geriatrics; any study design; reporting any outcome; only full papers; published in peer-reviewed journals; English language. RESULTS: Of the 1259 records retrieved, 26 were assessed for eligibility based on defined inclusion criteria and 7 studies were included in the final analysis. Two studies reported specific outcomes for dentists with lower, or even negative, post-training scores for interprofessional collaborative practice competences compared to other disciplines, but only one of them used a previously validated scale. There were no reports on the effect of IPE courses on dental trainees' gerodontology skill improvements or on their attitudes towards the older persons. CONCLUSION: The existing evidence is insufficient to determine any outcomes of formal interprofessional training of dentists in geriatrics. More studies with better experimental design should be developed. Among the strengths of IPE in geriatrics are the interdisciplinary nature of geriatric care, the sharing of common geriatric competences among participating disciplines and the opportunity to use nursing homes as a training site.

Thermal territories of the abdomen after caesarean section birth: infrared thermography and analysis.

OBJECTIVE: To develop and refine qualitative mapping and quantitative analysis techniques to define 'thermal territories' of the post-partum abdomen, the caesarean section site and the infected surgical wound. In addition, to explore women's perspectives on thermal imaging and acceptability as a method for infection screening. METHOD: Prospective feasibility study undertaken at a large University teaching hospital, Sheffield UK. Infrared thermal imaging of the abdomen was undertaken at the bedside on the first two days after elective caesarean section. Target recruitment: six women in each of three body mass index (BMI) categories (normal, 18.5-24.9 kg/m²; overweight 25-29.9 kg/m²; obese ≥30 kg/m²). Additionally, women presenting to the ward with wound infection were eligible for inclusion in the study. Perspectives on the use of thermal imaging and its practicality were also explored via semi-structured interviews and analysed using thematic content analysis. RESULTS: We recruited 20 women who had all undergone caesarean section. From the booking BMI, eight women were obese (including two women with infected wounds), seven women were overweight and five women had a normal BMI. Temperature (ºC) profiling and pixel clustering segmentation (hierarchical clustering-based segmentation, HCS) revealed characteristic features of thermal territories between scar and adjacent regions. Differences in scar thermal intensity profiles exist between healthy scars and infected wounds; features that have potential for wound surveillance. The maximum temperature differences (∆T) between healthy skin and the wound site exceed 2º C in women with established wound infection. At day two, two women had a scar thermogram with features observed in the 'infected' wound thermogram. CONCLUSION: Thermal imaging at early and later times after caesarean birth is feasible and acceptable. Women reported potential benefits of the technique for future wound infection screening. Thermal intensity profiling and HCS for pixel cluster dissimilarity between scar and adjacent healthy skin has potential as a method for the development of techniques targeted to early infection surveillance in women after caesarean section.

Thermographic mapping of the abdomen in healthy subjects and patients after enterostoma.

OBJECTIVE: Heat is a sign and symptom of surgical wound infection in wound assessment criteria but there is currently no diagnostic tool being used in clinical practice to assess the skin temperature of surgical wounds. Using thermal imaging, the objective of this study was to map the temperature of the healing surgical wound and to provide confirmatory data of: a) optimum IR imaging distance from skin temperature target field of view (FOV) b) body composition effects on abdominal skin surface temperature readings c) thermal mapping characteristics of infected versus non-infected wounds post stoma-closure. METHOD: The abdominal skin surface temperature of healthy, afebrile subjects was measured under controlled, ambient conditions in a small (240cm x 320cm) clinical room. Subject standing positions were 30cm, 60cm and 100cm from the IR camera. Abdominal skin surface temperature and thermal imaging maps were acquired in a population of surgical patients before and after closure of enterostoma. RESULTS: Subjects (30) aged 19-52 (median=29) years were recruited. At a distance of 100cm, each of nine anatomical regions showed a decrease in mean temperature as BMI increased. Subjects with BMI >25 had lower mean abdominal temperatures. Statistically significant differences were observed for right hypochondrium (p=0.022), left lumbar region (p=0.009), right lumbar region (p=0.010) and the umbilical region (p=0.021). Half of patients (5/10) developed surgical wound infection. CONCLUSION: Within the operating distances investigated, no significant effect on abdominal temperature readings was observed. With increasing BMI, lower abdominal temperatures were noted. The thermal pattern of abdominal surgical wounds reveals some differences between the healing and infected wound. Healing wounds showed changes in the thermal 'map'; an increase in temperature on the first post-operative day, and 'warming' over the subsequent five days. 'Cold spots' emerged on the thermogram of the surgical wounds which subsequently were shown to be infected. Within the setting of a clinical environment, distances up to 100cm did not significantly alter skin temperature readings within the FOV. There is a suggestion that body composition influences skin temperature. Infected surgical wounds appear 'colder' than healing wounds. DECLARATION OF INTEREST: The authors have no conflict or interest. The work was supported by a grant from the SingHealth Foundation.

Incidence and predictors of new-onset constipation during acute hospitalisation after stroke.

OBJECTIVES: We investigated new-onset constipation in patients with stroke compared with orthopaedic conditions and explored the predictors associated with constipation during acute hospitalisation. METHODS: This was a prospective matched cohort study of 110 patients comparing stroke patients (n = 55) with orthopaedic patients (n = 55) admitted to a large tertiary acute hospital. Both cohorts were matched by age and sex. The incidence of new-onset constipation which occurred during a patient's acute hospitalisation was determined. Demographics, comorbidity, clinical factors, laboratory parameters and medications were evaluated as possible predictors of constipation. RESULTS: The incidence of new-onset constipation was high for both stroke (33%) and orthopaedic patients (27%; p = 0.66). Seven stroke patients (39%) and four orthopaedic patients (27%) developed their first onset of constipation on day 2 of admission. Mobility gains (RR 0.741, p < 0.001) and the use of prophylactic laxatives (RR 0.331, p < 0.01) had a protective effect against constipation. Bedpan use (RR 2.058, p < 0.05) and longer length of stay (RR 1.032, p < 0.05) increased the risk of developing new-onset constipation. CONCLUSIONS: New-onset constipation is common among patients admitted for stroke and orthopaedic conditions during acute hospitalisation. The early occurrence, on day 2 of admission, calls for prompt preventive intervention for constipation.

Body weight, body image and primary postpartum haemorrhage: a review of the literature.

The prevalence of obesity during pregnancy is rising. Elevated BMI is a significant risk factor for adverse maternal and fetal outcomes, including primary postpartum haemorrhage (PPH). Addressing the issues surrounding obesity in pregnancy presents many biological, social and psychological challenges. BMI is an easily measured and modifiable anthropometrical risk factor and should be recorded in all pregnancies. BMI should be proactively managed prior to and during pregnancy. All women should be educated as to the risks of an elevated BMI during pregnancy and those at risk should have access to specialist medical and surgical support if required. Our aim was to investigate the associations between elevated BMI and adverse maternal and fetal outcomes including PPH, and to explore the psychological challenges of having an elevated BMI during pregnancy.

High-precision calibration of MRS thermometry using validated temperature standards: effects of ionic strength and protein content on the calibration.

Currently, there is very limited ability to measure the temperature of the brain, but a direct technique for its estimation in vivo could improve the detection of patients at risk of temperature-related brain damage, help in the diagnosis of stroke and tumour, and provide useful information on the mechanisms of thermoregulation of the brain. In this article, new calibrations in vitro of MRS thermometry using temperature-stabilised reference phantoms are reported. The phantoms comprise two concentric glass spheres: the inner sphere contains the phantom material to be measured by MRS, and the outer sphere contains a substance with a known temperature stable to within 0.2 °C. The substances were freezing organic fixed-point compounds (diphenyl ether and ethylene carbonate, freezing at 26.3 and 35.8 °C, respectively) or temperature-controlled circulating water. The phantom temperature was continuously monitored with a fluoroptic probe calibrated at the National Physical Laboratory with traceability to the International Temperature Scale 1990 (ITS-90). The MRS temperature calibration was obtained by measuring the chemical shift of water relative to N-acetylaspartate (NAA) in a single voxel as a function of temperature using a 1.5-T Philips Intera scanner. Measurements were made for several phantom materials to assess the effect of tissue composition on the water-NAA chemical shift against temperature calibration. The phantom mixtures contained 25 mm of NAA buffered to pH 6.5 or 7.5 and several ionic salts or bovine serum albumin (BSA). Spectra were acquired from 25 to 45 °C. The correlation between frequency differences and phantom temperature was very linear with small residuals. However, the linear fitting parameters varied with ionic composition and BSA concentration. The 'apparent' temperature (calibrated using the water-NAA frequency differences) decreased by approximately 1 °C for every 100 mm increase in ionic concentration and increased proportionally to the concentration of BSA.

Changes in rat n-3 and n-6 fatty acid composition during pregnancy are associated with progesterone concentrations and hepatic FADS2 expression.

The mechanisms responsible for changes to long-chain polyunsaturated fatty acid (LC PUFA) status during pregnancy have not been fully elucidated. Tissue samples were collected from virgin and pregnant (day 12 and 20) female rats. LC PUFA status, sex hormone concentrations and hepatic mRNA expression of FADS1, FADS2 and elongase were assessed. Day 20 gestation females had higher plasma and liver docosahexaenoic acid and lower arachidonic acid content than virgin females (P<0.05). There was higher FADS2 mRNA expression during pregnancy (P=0.051). Progesterone and oestradiol concentrations positively correlated with hepatic FADS2 mRNA expression (P=0.043, P=0.004). Progesterone concentration positively correlated with hepatic n-6 docosapentaenoic acid content (P=0.006), and inversely correlated with intermediates in LC PUFA synthesis including n-3 docosapentaenoic acid, γ-linolenic acid and 20:2n-6 (P<0.05). Changes in progesterone and oestradiol during pregnancy may promote the synthesis of LC PUFA via increased FADS2 expression.

A systematic review of the ASEPSIS scoring system used in non-cardiac-related surgery.

OBJECTIVE: To assess the validity, reliability and sensitivity of the ASEPSIS scoring system, used to assess non-cardiac related surgery for surgical wound infection. METHOD: Five studies were included in this review. One study discussed the development of the ASEPSIS scoring system; two studies were on its reliability, one study on the sensitivity and the final compared the ASEPSIS scoring system against other surgical wound infection criteria and definitions. Due to variation in study designs, the findings were summarised and presented in a narrative format. RESULTS: Validity and reliability were not established in assessing non-cardiac surgical sites. Sensitivity level was reported for non-cardiac surgical sites, but its reliability level declined as the severity of infection worsened. CONCLUSION: This review revealed that there are limited choices of scoring systems to assess different surgical sites for surgical wound infection. Currently, only the ASEPSIS scoring system is available, but it is not validated for use with non-sternal wounds. Therefore, it should be used cautiously when assessing non-cardiac surgical wound infection.

Use of a common food frequency questionnaire (FFQ) to assess dietary patterns and their relation to allergy and asthma in Europe: pilot study of the GA2LEN FFQ.

BACKGROUND/OBJECTIVES: Comparable international data on food and nutrient intake is often hindered by the lack of a common instrument to assess food intake. The objective of this study was within the Global Allergy and Asthma European Network of Excellence (GA(2)LEN), we developed and piloted a food frequency questionnaire (FFQ) to assess its validity in Europe. SUBJECTS/METHODS: Five countries participating in GA(2)LEN took part in the pilot study. A total of 200 adults aged 31-75 years were invited to complete a FFQ in two occasions and to give a blood sample. The intra-class correlation coefficient (ICC) was used to assess repeatability of the FFQ. Plasma phospholipid fatty acids (FAs) were analysed by gas chromatography. Pearson correlation was used to analyse the correlation between estimated dietary FA intake and plasma phospholipid FA levels. RESULTS: A total of 177 participants (89%) had complete data on FFQ(1) and plasma phospholipid FAs. In all, 152 participants (76%) completed both FFQs. ICCs between macronutrients ranged from 0.70 (saturated FAs) to 0.78 (proteins) and between 0.70 (retinol) and 0.81 (vitamin D) for micronutrients. Dietary n-3 FAs showed a good correlation with total plasma phospholipid n-3 FAs and with docosahexaenoic acid in the whole sample (0.40) and in individual countries. Poor correlations were observed for other FAs. CONCLUSIONS: The GA(2)LEN FFQ is an appropriate tool to estimate dietary intake for a range of nutrients across Europe regardless of cultural and linguistic differences. The FFQ seems to be useful to estimate the intake of n-3 FAs but not other FAs.

A systematic performance evaluation of brain and body temperature sensors using ultra-stable temperature references.

The impact of a rise in the temperature of the human brain in patients who have suffered cerebral damage is not completely understood. Current studies are ambiguous; some show that a high brain temperature, and others a low brain temperature, is an indicator of poor prognosis. The reported effect is often very subtle, at the <0.5 degrees C level, and this may be due to the performance, or even the location of the temperature sensor. This study investigates the first of these issues, i.e. the performance of the sensor. Here performance validation is undertaken for three commonly used temperature sensors for brain and body temperature measurement, using ultra-stable temperature references. At body temperature all three sensor types performed within manufacturer's specifications. Given that only a small number of temperature sensors were tested, the indication is that, provided the sensors are located correctly, the small observed differences in temperature are real - though the issue of clinical significance is still to be addressed.

The significance of altered temperature after traumatic brain injury: an analysis of investigations in experimental and human studies: part 2.

Raised body temperature is a common occurrence after severe traumatic brain injury (TBI). It is widely accepted that experimental evidence points to a harmful effect of raised temperature both during and after TBI. Consequently, the policy of many neurocritical care units is to implement therapies for body temperature control. This article reviews the evidence that links spontaneous temperature changes with worsened outcome after experimentally-induced and human brain trauma. The current evidence-base and rationale for treatment of raised temperature after TBI is presented with discussion positing areas for further work to explore the notion that raised temperature may not be deleterious in all neurosurgical patients.

Transfer times for patients with extradural and subdural haematomas to neurosurgery in Greater Manchester.

Delay in transfer of patients with acute extradural (EDH) or subdural (SDH) haematoma to definitive neurosurgical evacuation has a detrimental effect on outcome. From July 2003 to December 2005 we undertook a prospective analysis of patients admitted to our unit for neurosurgical evacuation of their haematoma, who were transferred from non-neurosurgical hospitals. Data was collected for: 1) overall transfer time, 2) time taken from injury or deterioration to CT scan, 3) time from CT scan to arrival at our unit, and 4) time from arrival at our unit to surgery. Overall 81 patients were eligible, of which 39 had an EDH and 42 a SDH. The median transfer times for EDH and SDH were 5.25 hours and 6.0 hours respectively. This paper discusses the factors that may prolong delays in the transfer of patients between hospitals and the way in which our unit is trying to improve the local service for the population of Greater Manchester.

Prevalence of toxin producing strains of Staphylococcus aureus in a pediatric burns unit.

The aims of the study were to determine the sites in a pediatric burns unit that were contaminated with Staphylococcus aureus. Samples from the environment in bedrooms and the common room were taken monthly for 6 months using blood agar for total counts and Baird-Parker agar for S. aureus. The air was sampled using an air-sampling device and settle plates. Hard and soft surfaces including bed, blanket, sofa, chair, taps, bathtub, soft toys, locker and cupboard in the same rooms were sampled using contact plates. Swabs were taken from staff monthly for 3 months. S. aureus isolates were tested for production of enterotoxins A-D and toxic shock syndrome toxin-1 using a reverse passive latex agglutination test. The results showed that S. aureus was recovered more frequently using settle plates than using the air sampler. All surfaces sampled were contaminated with S. aureus and contamination was greatest in frequently occupied rooms. A variety of toxin producing isolates were found with enterotoxin C isolates, either alone or in combination with TSST-1 (toxic shock syndrome toxin-1) dominant. The staff were transiently colonised with S. aureus strains with a different toxin production pattern. The results show that airborne transmission may be a route for infection by S. aureus and is responsible for contaminating the environment.

Differences between brain and rectal temperatures during routine critical care of patients with severe traumatic brain injury.

Theoretical models suggest that small differences only exist between brain and body temperature in health. Once the brain is injured, brain temperature is generally regarded to rise above body temperature. However, since reports of the magnitude of the temperature gradient between brain and body vary, it is still not clear whether conventional body temperature monitoring accurately predicts brain temperature at all times. In this prospective, descriptive study, 20 adults with severe primary brain trauma were studied during their stay in the neurointensive care unit. Brain temperature ranged from 33.4 to 39.9 degrees C. Comparisons between paired brain and rectal temperature measurements revealed no evidence of a systematic difference [mean difference -0.04 degrees C (range -0.13 to 0.05 degrees C, 95% CI), p = 0.39]. Contrary to popular belief, brain temperature did not exceed systemic temperature in this relatively homogeneous patient series. The mean values masked inconsistent and unpredictable individual brain-rectal temperature differences (range 1.8 to -2.9 degrees C) and reversal of the brain-body temperature gradient occurred in some patients. Brain temperature could not be predicted from body temperature at all times.

Accurate measurement of muscle belly length in the motion analysis laboratory: potential for the assessment of contracture.

Two-dimensional ultrasound imaging was combined with motion analysis technology to measure distances between remote anatomical landmarks. The length of the belly of the medial gastrocnemius muscle in five normal adults (nine limbs) was estimated using this technique. Our results in vivo were similar to the reported data for the lengths of muscles in cadavers, and were consistent with the expected relationship between muscle belly length and ankle joint angle. Experiments in vitro demonstrated that the accuracy of the device was better than 2 mm over 20 cm. Measurements on the same subject on different occasions showed that the results were repeatable in vivo. Rendering of the reconstructed volume of a foam phantom gave results comparable to photographic images. This validated technique could be used to measure muscle lengths in children with spastic cerebral palsy and indicate which muscles had fixed shortening, and to what extent.