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.

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

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.

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.

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.

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.

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.

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.

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.

The acute febrile response to burn injury in children may be modified by the type of intravenous fluid used during resuscitation — observations using fresh frozen plasma (FFP) or Hartmann's solution

Fever is a common clinical problem in burned children. The purpose of this study was to compare rectal temperature (T(r)) in two groups of children with burns, > or =10% of the total body surface area (tbsa) who received fresh frozen plasma (FFP) or a crystalloid solution (Hartmann's) for restoration of blood volume. Twelve to 16 h after the burn T(r) reached a peak. The children who had received FFP for restoration of blood volume had significantly higher fever than those children who received crystalloid solutions only.

The significance of peripheral skin temperature measurement during the acute phase of burn injury: an illustrative case report

An increase in the gradient between core and peripheral skin temperature is a common finding during the early post burn period which is often interpreted as an indication of inadequate circulating blood volume. In this case study we monitored the pattern of rectal and skin surface (toe) temperature and skin blood flow (by laser Doppler imaging) during the first 16 h after a 34% bath scald in a child (female) of 36 months. In the absence of invasive monitoring of cardiac output, clinical assessment of the adequacy of fluid resuscitation was made from changes in hourly urine volumes and regular (4-h) monitoring of haematocrit. Peripheral vasoconstriction, leading to an increase in the temperature gradient between the inside and outside of the body, was not related to either a fall in urine volume or to haemoconcentration. We suggest that during the first 16 h after burn injury, widening of the core-to-peripheral temperature gradient cannot be used reliably as a clinical indicator of inadequate circulating blood volume.

A survey into toxic shock syndrome (TSS) in UK burns units

Toxic shock syndrome (TSS) is a rare complication of a Staphylococcus aureus infection and is primarily seen in children with small burns. The true incidence of TSS in burns patients is not known and the number of presumptive cases rarely reported. This survey was undertaken to determine if the incidence of TSS in children with burns could be related to the type of dressing used to cover the wound. A questionnaire was compiled and sent to the Senior Nurse in charge of each of the UK burns units. General information on the number of admissions, age of the patient, cause of injury and burn wound management was sought. An 81% response was obtained after two mailshots and follow up telephone calls. Seventy percent (23/33) of units which answered the survey nursed children. Of these, eight units had either not encountered TSS previously or not had a case within the past two years. These units were small, admitting a maximum of 50 patients each year. Of the units where TSS was encountered, approximately 2.5% of children admitted showed symptoms of TSS. Of the units who nursed both adults and children, seven units had seen TSS in burned adult patients which has not been reported in the literature. Of the eight units where TSS had not been recently encountered, four routinely administered prophylactic antibiotics to prevent infection whereas routine administration of antibiotics occurred in only two of the 15 units where TSS was seen. Although wound management procedures differed slightly there were many similarities. These included wound cleaning with normal saline, covering with either silver sulphadiazine (1%) or povidone iodine (10%), depending upon the infection status, and dressing with a paraffin tulle, gauze and crepe bandages. No association between the management of the burn wound and subsequent development of TSS could be established.

Toxic shock syndrome toxin-1 (TSST-1) antibody levels in burned children

Young children with burns are at risk of developing a toxic shock-like illness during the first 2-3 days after the injury. The staphylococcal exotoxin, toxic-shock syndrome toxin-1 (TSST-1) is implicated in development of this illness. Low levels or absence of anti-TSST-1 antibodies may indicate susceptibility to this illness. Anti-TSST-1 antibody levels were measured in consecutive cases admitted to the children's burns unit. Results of antibody levels in 38 of the youngest children, aged 0.04-4.0 years are reported. At the time of admission to the unit 50% of the children had IgG antibodies to TSST-1. A higher number of young burned children had antibodies to TSST-1 than expected.

Ex-vivo expansion of bone marrow progenitor cells for hematopoietic reconstitution following high-dose chemotherapy for breast cancer

The use of hematopoietic growth factors, stromal monolayers, and frequent medium exchange allows the expansion of hematopoietic progenitors ex-vivo. We evaluated the use of ex-vivo expanded progenitor cells for hematopoietic reconstitution following high dose chemotherapy (HDC) in breast cancer patients. Patients with high-risk Stage II or metastatic breast carcinoma underwent bone marrow aspirations using general anesthesia. A total of 675-1125 x 10(6) mononuclear cells (MNC) were seeded for ex-vivo expansion for 12 days in controlled perfusion bioreactors (Aastrom Biosciences, Inc.). The bone marrow cultures, which included the stromal cells collected with the aspirate, were supplemented with erythropoietin, granulocyte-macrophage-colony stimulating factor (GM-CSF)/IL-3 fusion protein (PIXY 321), and flt3 ligand. Stem cell transplant was performed with expanded cells after HDC. A median bone marrow volume of 52.9 mL (range 42-187 mL) was needed to inoculate the bioreactors. Median fold expansion of nucleated cells (NC) and colony forming unit granulocyte-macrophage (CFU-GM) was 4.9 and 9.5, respectively. The median fold expansion of CD34+lin- and long-term culture-initiating culture (LTC-IC) was 0.42 and 0.32, respectively. Five patients were transplanted with ex-vivo expanded NC. Median days to an absolute neutrophil count > 500/microL was 18 (range 15-22). Median days to a platelet count > 20,000/microl was 23 (range 19-39). All patients had sustained engraftment of both neutrophils and platelets. Immune reconstitution was similar to that seen after HDC and conventional stem cell transplantation. We conclude that ex-vivo expansion of progenitor cells from perfusion cultures of small volume bone marrow aspirates, allows hematopoietic reconstitution after HDC.

Tympanic membrane temperature as a measure of core temperature

BACKGROUND

Ear thermometers are becoming popular as a method for measuring deep body (core) temperature.

AIM

To determine the variability of a single user's tympanic membrane (ear) temperature measurements.

SUBJECTS

Forty-two, afebrile, healthy children, and 20 febrile children with acute burns.

RESULTS

In afebrile children measurements made in both ears (and within just a few minutes of each other) differed by as much as 0.6 degree C. Operator measurement error, sw of three consecutive measurements, in the same ear, was 0.13 degree C. In the group of febrile, burned children, core temperature was measured hourly at a number of sites (ear, rectum, axilla, bladder). A peak in core temperature occurred approximately 10-12 hours after the burn. Measurement error was calculated in 14 febrile, burned children with a peak temperature in excess of 38 degrees C. For the left ear, measurement error was 0.19 degree C and for the right ear, 0.11 degree C. In the febrile children agreement between the ears was poor. The limits of agreement were 0.4 degree C to -0.8 degree C. It was not possible to predict the occasions when the temperature differences between the ears would be large or small.

CONCLUSIONS

The measurement error of one recording from the next is probably acceptable at about 0.1 to 0.2 degree C. To limit the variations in temperature of one ear to the other, measurements should be restricted to one of the ears whenever possible and the same ear used throughout the temperature monitoring period. Nurses and parents should take more than one temperature reading from the same ear whenever possible.

Suprasternal Doppler ultrasound for assessment of stroke distance

An assessment of a non-invasive technique for measurement of stroke distance was made using a portable Doppler ultrasound machine. The aim was to determine the measurement error of repeated stroke distance measurements (Within-observer variability) and to assess measurement agreement between two operators (between-observer variability). The measurement error (within-observer variability) for both operators was similar at approximately 2 cm. However, the measurements of the two operators (between-observer variability) did not agree well. Using the mean (SD) of three readings by each operator, the mean difference between the operators was -0.21 cm (1.96) giving a 95% confidence interval for the differences of -4.0 to +3.6 cm. There were significant positive and negative correlations between stroke distance and a variety of variables (age, height, weight, heart rate), but the relations were weak. The results indicate that the Doppler ultrasound technique for measurement of stroke distance would best be used to study trend changes in an individual patient, or subject, by a single operator.

The European Directory of Burns Research

The European Directory of Burns Research is a database of research activity in Europe. This ongoing database, established under the auspices of the Research Committee of the European Burns Association (EBA), provides basic information on research studies in progress or completed. The first issue, for the period 1995/1996, present information received after return of 118 questionnaires from researchers working in 27 countries in Europe and its close neighbours. This is not a large number of responses and may reflect problems with access to groups working in burns, but ignorant of the request for information on research activities. The aim is to maintain and update the database annually through distribution and return of a simple questionnaire. Information will be available to EBA members on request but the accuracy and detail of the database will ultimately be influenced by the co-operation of the burns research community.

Is there an evidence-based practice for burns?

Doubts and questions about clinical decision making need to be answered. Evidence-based medicine aims to provide answers by systematically finding information from the vast assortment of research papers in the literature and bringing it together to use in everyday practice and in the best interests of the patient. Although clinical (and experimental) studies have a variety of methodologies, ranging from small descriptive studies to large multi-centre trials all are vital in describing or posing questions about the array of responses elicited when human beings are burned and subsequently treated. When it comes to treatment (be it a drug, a dressing, an enteral feed for example) the 'gold standard' for establishing whether it is effective is the randomized controlled trial (RCT). Using contemporary information retrieval systems and the numerous establishments set up to help track down information of research in medicine relevant to health practice and policy the numbers of RCTs, systematic reviews and meta-analyses of burn care have been established. Whilst the numbers of RCTs are increasing there is little evidence that burn care is an evidence-based practice.

A comparison of phenotypic properties of Staphylococcus aureus isolated from burned children and other patient groups

This study aimed to determine whether strains of Staph. aureus isolated from children on our paediatric burns unit were different from strains isolated from other patient groups. Of particular interest was the incidence of toxin production amongst the different patient groups and the potential association with toxic shock syndrome (TSS). Wound isolates of Staph. aureus were collected from three patient groups: (1) hospital inpatients, (2) community patients and (3) patients from a regional burns unit. One hundred isolates were collected from each group (n = 300). Each isolate was tested for enterotoxin and TSST-1 production, phage type, antibiogram and tryptophan dependence. The results were compared, to determine whether there were any differences between the isolates from each of these patient groups. There were some variations in antibiotic sensitivity patterns and phage type of the isolates between the different patient groups but there was no significant difference in the incidence of toxin production, which was an important observation. The 100 isolates collected from this burns unit were derived from 58 patients. The colonization patterns of the Staph. aureus showed that 12 patients were colonized by more than one isolate and that these were a mixture of toxin-positive and toxin-negative strains. The medical records were examined for evidence of TSS; there was a higher incidence of toxic episodes in the patients colonized with strains which produced TSST-1 toxin.

KBM-7, a human myeloid leukemia cell line with double Philadelphia chromosomes lacking normal c-ABL and BCR transcripts

A human myeloid leukemia cell line, KBM-7, was developed from a patient in the blastic phase of chronic myeloid leukemia (CML). We characterized its morphology, immunophenotype, cytogenetics, and proliferative capacity. Developed in the absence of exogenous lymphokines, KBM-7 in vitro cloning capacity actually decreased when colony-stimulating factors were added. The cells had an aberrant immature myeloid phenotype, a doubling time of 22 h in suspension cultures and a high cloning efficiency in semisolid system (24 +/- 3)%. Early passages contained one near-haploid (predominant) and one hyperdiploid stem line. Gradually the hyperdiploid stem line became predominant, reaching an average of 49 chromosomes per cell. Cells from passage 89 had two Philadelphia chromosomes [t(9;22)(q34;q11)] and lacked normal copies of chromosomes 9 and 22. Detailed molecular characterization of the breakpoint in the t(9;22)(q34;q11) revealed that KBM-7 had the BCR 2/ABL II splice junction. The cells had high protein kinase (p210BCR-ABL) activity and carried two identified variants of an ABL-BCR message. There was no evidence that normal BCR or c-ABL messages were expressed, assessed with the reverse-transcriptase polymerase chain reaction. When KBM-7 cells were heterotransplanted into nude mice without immunosuppressive pretreatment, one of three mice injected with 1 x 10(7) cells and all mice injected with 1 x 10(8) cells developed slowly growing granulocytic sarcomas within 6-8 weeks. These tumors were locally invasive but did not metastasize. We conclude that the KBM-7 cell line will be of value for investigating molecular events underlying neoplastic transformation in CML, in particular for studying the effects of BCR-ABL and ABL-BCR on the proliferation of CML cells in the absence of normal BCR and c-ABL messages.

A microprocessor based photoplethysmograph for use in clinical practice

A microprocessor-based system of photoplethysmography and its use in measuring skin blood flow is described. The system was designed specifically for use over long periods and for the analysis of the output to be handled by a personal computer. The photoplethysmograph described in this paper is shown to be a qualitative method for assessment of changes in peripheral skin blood flow. There is potential for use of this instrument in a variety of clinical conditions.

Oxygen consumption during sleep in atopic dermatitis

Measurements of oxygen consumption (VO2) were made during sleep in 10 patients with atopic dermatitis. Two groups of healthy children acted as controls. All subjects were studied in bed in an environmental temperature of 24-26 degrees C, and sleep was confirmed during continuous electroencephalographic monitoring. Mean (SD) values of VO2 in sleeping patients who were not scratching ranged from 4.0 (0.4) to 7.4 (0.7), which was not statistically significantly different from control values which ranged from 3.24 (0.3) to 5.56 (0.4). During scratching (while asleep), which occurred in nine out of 10 patients with atopic dermatitis, the mean values of VO2 ranged from 4.5 (0.04) to 10.4 (2.7), and this was significantly higher than the non-scratching patients and the control values. Scratching during sleep in children with atopic dermatitis is associated with increased VO2.

Patterns of Staphylococcus aureus colonization, toxin production, immunity and illness in burned children

Toxic shock syndrome toxin-one (TSST-1) produced from some but not all strains of Staphylococcus aureus is considered to be responsible for the development of the serious illness, toxic shock syndrome (TSS). The aim of this study was to establish the importance of S. aureus in the aetiology of suspected cases of TSS in acutely burned children. The pattern of colonization of S. aureus, and in particular toxic shock syndrome toxin-one (TSST-1) producing isolates, was studied in 53 burned children admitted as consecutive cases. S. aureus was not normally present on admission. Although it was the most common wound pathogen, it was acquired during the first few days after admission. Antibody status to TSST-1 on admission and at discharge was determined. Only half (49 per cent) of the children had antibodies to TSST-1. When it was possible to obtain paired admission and discharge samples in patients who had been given blood products, an assessment of seroconversion could be made. Two of the four patients given blood products during the resuscitation and postoperative period were antibody negative on admission (the other two were TSST-1 antibody positive). By discharge they had antibodies to TSST-1. Whilst the majority of donated blood products had antibodies to TSST-1 (76 per cent), some (24 per cent) did not. Seven of 53 children (13 per cent) developed a toxic shock-like illness which caused clinical concern.(ABSTRACT TRUNCATED AT 250 WORDS)

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Acute changes in oxygen consumption and body temperature after burn injury

This study describes the pattern of oxygen consumption (VO2), rectal temperature (Tr), and acral skin temperature (Tac) in sleeping and resting (awake) burned children nursed in a thermoneutral environment. Measurements of respiratory gas exchange (VO2 and carbon dioxide production (VCO2)) were made using an open circuit, flow through system of indirect calorimetry. Tr and Tac were monitored continuously. Sixteen patients were studied during the first 18 hours after being burned. Three phases of change in VO2, Tr, and Tac are described. The first was a stable period and there was little change from admission values. The second (7-10 hours after burn) was a phase of rapid heat storage. It started with a fall in Tac. Peak values of Tr (38.8-41.1, median 40.0 degrees C) and VO2 (8.5-11.8 ml/min/kg) occurred either in phase 2 or in the later phase 3. At its peak VO2 was 12-61% above values in phase 1. In phase 3, Tac returned towards admission values but Tr and VO2 were variable. These changes suggest that both an increase in metabolic heat production as well as heat conservation at the extremities may be involved in the generation of early fever after a burn.

Epstein-Barr virus DNA is abundant and monoclonal in the Reed-Sternberg cells of Hodgkin's disease: association with mixed cellularity subtype and Hispanic American ethnicity

One hundred twenty-five cases of Hodgkin's disease from the United States (79), Mexico City (31), and Costa Rica (15) were analyzed for the presence of Epstein-Barr virus (EBV) by in situ hybridization to EBER1 transcripts. EBV was more frequently detected in the Reed-Sternberg (RS) cells of mixed cellularity Hodgkin's disease (37 of 48 [77%]) compared with the nodular sclerosis subtype (19 of 71 [27%], P < .001). The presence of EBV was also associated with Hispanic ethnicity (P < .001). In a multivariate analysis, patient age, gender, and geographic location were less predictive of EBV positivity than were mixed cellularity histology (odds ratio = 8.3) and Hispanic ethnicity (odds ratio = 4.3). Southern blot analysis of EBV terminal repeat fragments using the Xho1a probe showed that the viral DNA was monoclonal in 17 of 17 cases having EBER1-positive RS cells. By comparison, EBV DNA was not detected by Southern analysis in 20 cases lacking EBER1 in RS cells, even when occasional background lymphocytes expressed EBER1. Because clonal viral DNA was so readily detected in EBER1-positive cases, the EBV genome is probably amplified at least 50-fold in the infected RS cells. Monoclonality of EBV DNA implies that the RS cells were infected before malignant transformation.

Metabolic rate at rest and during sleep in a thermoneutral environment

This study characterised the pattern of oxygen consumption (VO2) in healthy infants and children asleep and awake (at rest) in a thermoneutral environment. Measurement of respiratory gas exchange (VO2 and VCO2) was made using an open circuit flow through system of indirect calorimetry with a specially designed facemask for the collection of exhaled breath. Fifty two healthy subjects aged 4.5 months to 12.8 years were studied for 15-20 minutes; 18 during sleep and 34 at rest (awake). There was a curvilinear relation between VO2 and age in the two groups and children aged 2 years or less had the highest values. The value of VO2 was significantly higher in the awake subjects (12.5-15.0 ml/min/kg compared with 7.5-9.0 ml/min/kg in sleeping children). Comparison of the regression lines after log transformation of these data showed a significant difference in VO2 of resting and sleeping subjects up to the age of 9.5 years.

Cutaneous heat loss shortly after burn injury in children

1. Total heat loss and its components have been studied in cool (20 degrees C) and warm (30 degrees C) environments in 30 healthy children and 21 children who had been burned (10-17% body surface area) 0.5-29 h previously. 2. In healthy naked children at 20 degrees C, the partition of total heat loss was: radiation, 64%; convection, 32%; evaporation, 4%. On transfer to the warm, total heat loss was reduced by approximately 50%, with disproportionate reductions in the contributions from radiation and convection being offset, to some extent, by an increase in evaporative heat loss. 3. In patients during the first 5.5h after injury, the magnitude and pattern of heat loss at 20 degrees C and 30 degrees C were similar to those in control subjects and were unaffected by bandaging. 4. Ten to twenty-nine hours after injury, when the patients were bandaged and body temperature and heat content were significantly higher than in control subjects, radiant and convective heat losses were increased, but as evaporative heat loss tended to be reduced; total heat loss in the warm was unchanged. However, at this time at 20 degrees C, total heat loss was reduced compared with healthy children at the same ambient temperature. 5. The findings of unchanged or reduced total heat loss and reduced evaporative heat loss in injured patients are interpreted as inappropriate responses to an increased body temperature and heat content in children after burn injury.

KBM-3, an in vitro model of human acute myelomonocytic leukemia

A human acute myelomonocytic leukemia cell line, KBM-3, was developed to study the pathophysiology of human acute myeloid leukemia. This cell line was characterized by morphology, immunophenotype, Giemsa-banding pattern, in vitro proliferation capacity, and tumorigenicity in nude mice. The KBM-3 cell line was established in the presence of exogenous lymphokines (human placenta-conditioned medium, HPCM), but medium for later passages did not contain HPCM. We found high cellular expression of the mRNA message for granulocyte-macrophage colony-stimulating factor (GM-CSF), which we suggest may be important for the immortalization of the cell line. KBM-3 cells have an immature myelomonocytic phenotype. Cytogenetic analysis revealed a pseudodiploid karyotype with five characteristic marker chromosomes and ranging in total number from 45 to 49. In suspension cultures, the cells had a doubling time of 23 h and a cloning efficiency of about 30% in soft agar independent of exogenous lymphokines. Two-thirds of nude mice injected with 1 x 10(4) KBM-3 cells and all animals injected with 1 x 10(5) cells developed S.C. granulocytic sarcomas within 6-8 weeks. These tumors were locally invasive but did not give rise to distant metastases. When transplanted to a new set of nude mice, all tumors formed secondary sarcomas at the site of implant. We conclude that the KBM-3 cell line may have value for studying the molecular events that underlie the neoplastic transformation in human myeloid leukemia.

Development of an indirect calorimeter for use in infants and young children

A low cost, 'open-circuit', flow-through system, using a closely fitted facemask has been developed for the determination of oxygen consumption and carbon dioxide production in spontaneously breathing infants and children.

The role of gene rearrangements for antigen receptors in the diagnosis of lymphoma obtained by fine-needle aspiration. A study of 63 cases with concomitant immunophenotyping

To assess the efficacy of performing genotyping in addition to immunophenotyping as an adjunct to cytologic diagnosis, 63 consecutive patients with fine-needle aspirates of lymphoproliferative lesions who had concurrent immunophenotyping and genotyping performed on fine-needle aspirate cell suspensions were studied. Thirty-nine of 63 specimens (62%) that appeared to contain non-Hodgkin's lymphoma and that proved to be of B-cell lineage by genotyping were accurately phenotyped and shown to be monotypic for immunoglobulin light chains by cell suspension immunocytochemistry. Genotyping facilitated lineage assignment and/or confirmed clonality in 17 of 63 specimens (27%) that were difficult to determine based on morphologic data. These include cases of atypical lymphoid proliferations with polyclonal or inconclusive markers (n = 6), peripheral T-cell lymphoma (n = 3), extracutaneous mycosis fungoides (n = 1), lymphoblastic lymphoma (n = 4), null cell lymphoma (n = 1), and specimens with equivocal or technically unsatisfactory markers (n = 2). Based on these results, it is proposed that genotyping for lineage assignment and/or clonality be performed to include cases of atypical lymphoid proliferations, T-cell malignant neoplasms, lymphoid malignant neoplasms with equivocal markers, and differentiation of lymphoid from nonlymphoid neoplasms. Genotyping by antigen-receptor gene rearrangement appears to be redundant in cases with mature B-cell phenotypes that demonstrate monoclonality by immunophenotyping.