The effect of light intensity on image quality in endoscopic ear surgery.

OBJECTIVES: Endoscopic ear surgery is a rapidly developing field with many advantages. But endoscopes can reach temperatures of over 110°C at the tip, raising safety concerns. Reducing the intensity of the light source reduces temperatures produced. However, quality of images at lower light intensities has not yet been studied. We set out to study the effect of light intensity on image quality in EES. DESIGN: Prospective study of patients undergoing EES from April to October 2016. Consecutive images of the same operative field at 10%, 30%, 50% and 100% light intensities were taken. Eight international experts were asked to each evaluate 100 anonymised, randomised images. SETTING: District General Hospital. PARTICIPANTS: Twenty patients. MAIN OUTCOME MEASURES: Images were evaluated on a 5-point Likert scale (1 = significantly worse than average; 5 = significantly better than average) for detail of anatomy; colour contrast; overall quality; and suitability for operating. RESULTS: Mean scores for photographs at 10%, 30%, 50% and 100% light intensity were 3.22 (SD 0.93), 3.15 (SD 0.84), 3.08 (SD 0.88) and 3.10 (SD 0.86), respectively. In ANOVA models for the scores on each of the scales (anatomy, colour contrast, overall quality and suitability for operating), the effects of rater and patient were highly significant (P < .0005) but light intensity was non-significant (P = .34, .32, .21, .15, respectively). CONCLUSION: Images taken during surgery by our endoscope and operative camera have no loss of quality when taken at lower light intensities. We recommend the surgeon considers use of lower light intensities in endoscopic ear surgery.

Prevalence of being underweight and overweight and obesity at diagnosis in UK patients with childhood acute lymphoblastic leukaemia 1985-2002.

BACKGROUND: Being underweight or overweight and obesity at diagnosis may all worsen prognosis in childhood acute lymphoblastic leukaemia (ALL), although no studies have estimated the prevalence of an unhealthy weight status at diagnosis in large representative samples using contemporary definitions of weight status based on body mass index (BMI) for age. METHODS: The present study comprised a retrospective study that aimed to estimate prevalence of being underweight and overweight and obesity at diagnosis for patients with childhood ALL on three successive UK treatment trials: UKALL X (1985-1990; n = 1033), UKALL XI (1990-1997; n = 2031), UKALL 97/99 (1997-2002; n = 898).The BMI for age was used to define weight status with both UK 1990 BMI for age reference data and the Cole-International Obesity Task Force (IOTF) definitions. RESULTS: The prevalence of being underweight was 6% in the most recent trial for which data were available. The prevalence of being overweight and obesity was 35% in the most recent trial when expressed using Cole-IOTF definitions and 41% when expressed relative to UK 1990 reference data. CONCLUSIONS: Even with highly conservative estimates, >40% of all UK patients with ALL were underweight, overweight or obese at diagnosis in the most recent trial for which UK data are available (UKALL 97/99, 1997-2002).

Forest fire: effects on phosphorus movement to lakes.

After a wildfire in the virgin forest of a lake-watershed region in northeastern Minnesota, the phosphorus concentration in the runoff was elevated for 2 years and decreased in the third year. However, there was no increase in the phosphorus concentrations of a lake and its input stream. This indicates that, under similar circumstances, controlled burning will not damage streams or lakes by elevating phosphorus levels.

Development of bioelectrical impedance-derived indices of fat and fat-free mass for assessment of nutritional status in childhood.

OBJECTIVES: (1) To develop a method of manipulating bioelectrical impedance (BIA) that gives indices of lean and fat adjusted for body size, using a large normative cohort of children. (2) To assess the discriminant validity of the method in a group of children likely to have abnormal body composition. DESIGN: Two prospective cohort studies. SETTING: Normative data: Avon Longitudinal Study of Parents and Children (ALSPAC), population based cohort; proof of concept study: tertiary feeding clinic and special needs schools. SUBJECTS: Normative data: 7576 children measured aged between 7.25 and 8.25 (mean 7.5) (s.d.=0.2) years; proof of concept study: 29 children with either major neurodisability or receiving artificial feeding, or both, mean age 7.6 (s.d.=2) years. MEASURES: Leg-to-leg (Z (T)) and arm-to-leg (Z (B)) BIA, weight and height. Total body water (TBW) was estimated from the resistance index (RI=height(2)/Z), and fat-free mass was linearly related to TBW. Fat mass was obtained by subtracting fat-free mass from total weight. Fat-free mass was log-transformed and the reciprocal transform was taken for fat mass to satisfy parametric model assumptions. Lean and fat mass were then adjusted for height and age using multiple linear regression models. The resulting standardized residuals gave the lean index and fat index, respectively. RESULTS: In the normative cohort, the lean index was higher and fat index lower in boys. The lean index rose steeply to the middle of the normal range of body mass index (BMI) and then slowly for higher BMI values, whereas the fat index rose linearly through and above the normal range. In the proof of concept study, the children as a group had low lean indices (mean (s.d.) -1.5 (1.7)) with average fat indices (+0.21 (2.0)) despite relatively low BMI standard deviation scores (-0.60 (2.3)), but for any given BMI, individual children had extremely wide ranges of fat indices. The lean index proved more stable and repeatable than BMI. CONCLUSIONS: This clinical method of handling BIA reveals important variations in nutritional status that would not be detected using anthropometry alone. BIA used in this way would allow more accurate assessment of energy sufficiency in children with neurodisability and may provide a more valid identification of children at risk of underweight or obesity in field and clinical settings.

Pathways into and out of overweight and obesity from infancy to mid-childhood.

OBJECTIVES: To investigate whether high weight in infancy predicts obesity in childhood. METHOD: Data from two UK cohorts (Newcastle Growth and Development N = 795, Gateshead Millennium N = 393) and one Finnish (Tampere N = 1262) were combined. Z scores of weight at 3 and 12 months and body mass index (BMI) at 5 and 8 years were categorized as raised/overweight (1 to <2 SD) or high/obese (≥2 SD). RESULTS: The majority of infants with raised or high weight at birth tended to revert to normal by 3 months and to track in the same category from 3 to 12 months. Although infants with high weight were five times more likely to have BMI ≥ 2 SD at 8 years (p < 0.001), only 22% went on to have BMI ≥ 2 SD, while 64% of infants with raised weight had normal BMI at 8 years. Of children with BMI ≥ 2 SD aged 8 years, only 22% had raised weight in infancy and half had BMI ≥ 2 SD for the first time at that age. CONCLUSIONS: Infants with raised weight in infancy tend to remain so, but most children who go on to have BMI ≥ 2 SD were not unusually heavy infants and the majority of infants with high weight reverted to overweight or normal weight in childhood.

Surface rearrangement of adsorbed EGCG-mucin complexes on hydrophilic surfaces.

The kinetic adsorption-desorption behaviour of porcine gastric mucin in the presence of physiologically relevant concentrations of the polyphenol epigallocatechin gallate (EGCG) was investigated using high-resolution kinetic optical waveguide lightmode spectroscopy (OWLS) and atomic force microscopy (AFM). Comparison with dynamic light scattering results from EGCG-mucin mixtures indicates that discrete particles are formed whose size increases with increasing EGCG:mucin ratio. These particles are deduced to be the adsorbing entities, which fuse on the surface to form complex surface layers. At low molar EGCG:mucin ratios (<∼1000), aggregates fuse on the surface to form a monolayer similar to one of pure mucin. With increasing EGCG concentration, the surface assembly of aggregates becomes consistent with their rearrangement and spreading in the shape of a spherical segment. At the highest molar ratios investigated (>12,000) the particles begin to destabilize. The presence of EGCG leads to birefringence hysteresis during adsorption-desorption, indicating structural rearrangement, even at molar ratios ∼1000. The intensification of the phenomenon with increasing EGCG:mucin ratio mimics what was previously observed with the increase of mucin concentration in an EGCG-free system.

Neonatal nephrocalcinosis: long term follow up.

AIMS: To assess the spontaneous resolution of neonatal nephrocalcinosis and its long term effects on renal function. METHODS: Fourteen very low birthweight preterm babies with nephrocalcinosis were followed up at 5-7 years of age; 14 controls were matched for sex, gestation, and birth weight. Height, weight, blood pressure, and renal symptomatology were recorded, and a renal ultrasound scan was performed. Early morning urine osmolality and creatinine ratios of albumin, phosphate, calcium, oxalate and beta microglobulin were determined. Urea and electrolytes in the study group were determined, and glomerular filtration rate (GFR) and TmP/GFR (tubular reabsorption of phosphate per GFR) were calculated. Statistical analysis was performed on a group basis using the Mann-Whitney confidence interval. RESULTS: Mean age was 6.9 years (range 5.81-7.68). An early morning urine osmolality >700 mOsm/kg was achieved in all cases. In two cases and four controls, the calcium/creatinine ratio was >0.7 mmol/mmol. In all cases, the GFR was normal (median 132.6 ml/min/1.73 m(2) (range 104.1-173.1)). Median TmP/GFR was 1.22 mmol/l (0.73-1.61), with two having levels below the normal range. These did not have persisting nephrocalcinosis. Nephrocalcinosis was found in three of the 12 cases scanned and one control. There were no significant differences in urine biochemistry. CONCLUSIONS: Resolution of nephrocalcinosis occurred in 75% of cases. No evidence was found to suggest that nephrocalcinosis is associated with renal dysfunction in the long term. There was evidence of hypercalciuria in the cases and controls, suggesting that prematurity may be a risk factor.

Statistical issues in the analysis of neuroimages.

Statistical issues in the analysis of neuroimages are reviewed. These include biological questions of interest, basic problems of measurement and experimental design, normalisation, standardisation and transformation, and statistical methodology. Finally, three data sets are reviewed to illustrate some of the issues raised in the report.

Photodynamic therapy for large or multiple patches of Bowen disease and basal cell carcinoma.

BACKGROUND: Photodynamic therapy (PDT) using topical delta-aminolevulinic acid (delta-ALA) is an effective treatment for Bowen disease and certain basal cell carcinomas (BCCs), but its place in clinical practice remains to be established. Patients with large and/or multiple lesions of Bowen disease or BCC can represent a considerable therapeutic challenge. We suggest that delta-ALA PDT may be of particular benefit in such patients. OBSERVATION: In an open study, 35 (88%) of 40 large patches of Bowen disease, all with a maximum diameter greater than 20 mm, cleared following 1 to 3 treatments of delta-ALA PDT, although 4 patches recurred within 12 months. delta-Aminolevulinic acid PDT was also used to treat 40 large BCCs, with an identical 88% initial clearance (after 1-3 treatments), with 4 recurrences within 34 months (range, 12-60 months). In 10 further patients with multiple (> or =3) patches of Bowen disease, 44 (98%) of 45 patches cleared following delta-ALA PDT, although 4 lesions recurred over 12 months. In 3 patients with multiple BCCs, PDT cleared 52 (90%) of 58 lesions, with 2 recurrences during 41 months (range, 12-52 months). Treatments were well tolerated, with only 5 patients with solitary large lesions requiring local anesthesia. CONCLUSIONS: delta-Aminolevulinic acid PDT is an effective tissue-sparing modality achieving good cosmesis. We propose that delta-ALA PDT be considered as a first-line therapy for large and/or multiple areas of Bowen disease and superficial BCCs.

Nephrocalcinosis in preterm babies.

OBJECTIVES: To determine prospectively the incidence and cause of nephrocalcinosis in preterm infants. STUDY DESIGN: Inborn babies of gestation less than 32 weeks or birth weight less than 1500 g were eligible to be entered into a prospective observational study. Two renal ultrasound scans were performed, the first at 1 month postnatal age and the second at term or discharge. Data were collected on gestation, birth weight, sex, race, family history of renal calculi, oliguria on first day, respiratory support (ventilation, steroid, and oxygen dependency), and use of nephrotoxic drugs (gentamicin, vancomycin, and frusemide). Intake of fluid, calcium, and phosphate and plasma urea, creatinine, calcium, and phosphate were recorded for the first 6 weeks of life. Random urinary calcium/creatinine, oxalate/creatinine, and urate/creatinine ratios and tubular absorption of phosphate were measured once at term. RESULTS: A total of 101 preterm infants were studied. Twenty three (23%) had abnormal ultrasound scans. Sixteen (16%) had nephrocalcinosis. On univariate analysis, gestational age, male sex, duration of ventilation, oxygen dependency, duration and frequency of gentamicin treatment, toxic gentamicin/vancomycin levels, and postnatal dexamethasone were significantly associated with nephrocalcinosis. In addition, babies with nephrocalcinosis had a lower intake of fluid, calcium, and phosphate, longer duration of total parenteral nutrition, and higher urinary oxalate/creatinine and urate/creatinine ratios than infants who did not have the condition. There was also a significant association with plasma urea and creatinine but not with plasma calcium or phosphate or urinary calcium. Multivariate analysis showed that the strongest predictors of nephrocalcinosis were duration of ventilation, toxic gentamicin/vancomycin levels, low fluid intake, and male sex. CONCLUSION: 16% of babies born at less than 32 weeks gestation developed nephrocalcinosis. The multifactorial origin, in particular, the association with extreme prematurity and severity of respiratory disease, is confirmed. In addition, an association with male sex, frequency and duration of gentamicin use, and high urinary oxalate and urate excretion is shown.

Statistical methods in neuroimaging with particular application to emission tomography.

We review statistical methods being applied in four key areas connected with PET and SPECT neuroimaging: (i) image reconstruction (briefly); (ii) tracer-kinetic, or compartmental, modelling; (iii) inference from region-of-interest data; (iv) inference at the pixel or voxel level. Under the last heading, we pay particular attention to the analysis of data from serial scans. We conclude by identifying some topics for future statistical research.

Protein energy supplements in unwell elderly patients--a randomized controlled trial.

BACKGROUND: To determine whether oral protein energy supplements, prescribed during hospitalization to elderly medical admissions, affect nutritional status and if baseline nutritional state influences this status. We also considered the effects on mortality, length of hospital stay, functional recovery, and institutionalization. METHODS: A prospective randomized controlled trial with no placebo. Consenting patients were stratified in 3 nutritional categories, and patients from each stratum were randomized into treatment or control. Observers were blinded to randomization. The participants were emergency admissions from home to a Medicine for the Elderly Unit in a Scottish hospital. The inclusion criteria were as follows: no known malignancy, the ability to swallow, and nonobesity (BMI < 75th percentile). The intervention was a prescription of 120 mL sip feed, 3 times daily (540 kcal, 22.5 g protein per day) throughout hospitalization, using the medicine prescription chart. The trial was powered to detect change in mean percentage weight. The following outcomes were also considered: anthropometry; mortality, length of hospital stay, functional recovery, and rates of institutionalization. RESULTS: Included in the trial were 381 patients. Nutritional supplementation was associated with significantly better energy intake (p = .001) and weight gain (p = .003) pooled across all nutritional categories. In the most poorly nourished patients, the intervention was associated with reduced mortality (5/34 versus 14/40, p < .05) and more patients improved functionally (17/25 versus 11/28, p < .04). Overall mortality results were 21/186 versus 33/195, odds ratio (OR) 0.62, 95% confidence interval (CI) 0.35, 1.13. CONCLUSIONS: Prescribing sip feed supplements in the medicine prescription chart during hospital stay reduces weight loss. Our data also support other evidence for a reduction in mortality noted in elderly patients on nutritional supplementation. There were suggestions of other clinical benefits.

Cognitive functioning in people with epilepsy plus severe learning disabilities: a systematic analysis of predictors of daytime arousal and attention.

In spite of the high prevalence of epilepsy and the importance of preserving cognitive function in people with learning disabilities, this population has received relatively little research attention. This study sets out systematically to investigate possible predictive factors of inter-ictal states of arousal and attention. The daytime function of 28 people with epilepsy and severe learning disabilities was assessed by performance on a two-choice reaction time vigilance task, behavioural analysis of time-sampled video recordings taken in naturalistic settings, and carer ratings on visual analogue scales. This methodology yielded eight discrete functional measures, from which two further index measures were derived after principal components analysis. A range of clinical and psychosocial assessments was completed and subjects had 36 hour ambulatory EEG and sleep EEG monitoring. Regression models identified significant predictors of cognitive function from a range of potential explanatory variables i.e. demographic, clinical, pharmacological, background EEG rhythms and sleep parameters. Results indicated that greater severity of learning disability, longer bedtime periods, poor sleep efficiency, frequent seizures and antiepileptic drug polytherapy were significant predictor variables. Explained variance (adjusted R2) was greater than 50% for six of 10 outcome variables (range up to 85%). Furthermore, significant regression equations (P < 0.05) were obtained for all but one variable. Thus, these results appear reasonably robust. Results support an interactional model of daytime arousal and attention in people with epilepsy plus severe learning disabilities. Inter-ictal cognitive function appears to be mediated by a combination of organic, circadian (sleep wake), clinical and pharmacological factors.

Sleep studies of adults with severe or profound mental retardation and epilepsy.

Sleep patterns of people with mental retardation have received little research attention. This is an important gap in knowledge because understanding the relation between sleep and wakefulness may be critical to care provision. Descriptive sleep information on 28 people with severe or profound mental retardation and epilepsy was presented here. Sleep EEG data, studied both conventionally and by means of a neural network-based sleep analysis system suggest atypical sleep stages with significant depletion of REM sleep and a predominance of "indiscriminate" non-REM sleep. Sleep diaries completed by caregivers reveal lengthy sleep period times, especially among those with profound mental retardation. Possible explanations for these results and their implications were discussed.

Soil and litter phosphorus-31 nuclear magnetic resonance spectroscopy: extractants, metals, and phosphorus relaxation times.

Phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy is an excellent tool with which to study soil organic P, allowing quantitative, comparative analysis of P forms. However, for 31P NMR to be tative, all peaks must be completely visible, and in their correct relative proportions. There must be no line broadening, and adequate delay times must be used to avoid saturation of peaks. The objective of this study was to examine the effects of extractants on delay times and peak saturation. Two samples (a forest litter and a mineral soil sample) and three extractants (0.25 M NaOH, NaOH plus Chelex (Bio-Rad Laboratories, Hercules, CA), and NaOH plus EDTA) were used to determine the differences in the concentration of P and cations solubilized by each extractant, and to measure spin-lattice (T1) relaxation times of P peaks in each extract. For both soil and litter, NaOH-Chelex extracted the lowest concentrations of P. For the litter sample, T1 values were short for all extractants due to the high Fe concentration remaining after extraction. For the soil sample, there were noticeable differences among the extractants. The NaOH-Chelex sample had less Fe and Mn remaining in solution after extraction than the other extractants, and the longest delay times used in the study, 6.4 s, were not long enough for quantitative analysis. Delay times of 1.5 to 2 s for the NaOH and NaOH-EDTA were adequate. Line broadening was highest in the NaOH extracts, which had the highest concentration of Fe. On the basis of these results, recommendations for future analyses of soil and litter samples by solution 31P NMR spectroscopy include: careful selection of an extractant; measurement of paramagnetic ions extracted with P; use of appropriate delay times and the minimum number of scans; and measurement of T1 values whenever possible.

The use of removable orthodontic appliances in the General Dental Service.

One hundred and fifty removable appliance cases consecutively sampled by the Scottish Dental Practice Board were analysed using the PAR index. The cases were assessed as being suited or unsuited to the removable appliance approach based on the presenting features previously shown to be effectively treated by removable appliances. Using chi-squared tests of association, suitable cases were characterised as being in the mixed dentition, had one feature treated and one appliance used. Suitable cases on average showed 3-4 PAR points more improvement as a result of treatment than equivalent unsuitable cases; regression equations are given. Because of the wide variability within the sample it proved impossible to predict accurately the expected duration of treatment in the General Dental Service.

Cephalometric features in the parents of children with orofacial clefting.

This nonrandomised retrospective case-comparison survey was based on the hypothesis that craniofacial morphometric features can be used to identify individuals at greater risk for having children with a cleft. The theory of aetiological heterogeneity suggests there may be differences according to gender and cleft type. From a completely ascertained sample of 286 children with cleft lip and/or palate born in the West of Scotland between 1 January 1980 and 31 December 1984, a sample of 83 parents of the children with non-syndromic clefts volunteered for lateral cephalometric examination. A comparison group was derived from the archives of Glasgow Dental Hospital. Multivariate statistical analyses were applied to identify which parental craniofacial parameters, if any, determine predisposition to orofacial clefting. Compared to the male comparison group, the fathers of children with CL(P) were shown to have reduced mandibular and symphyseal areas (P < 0.001), reduced maxillary area (P < 0.01) and a shorter palatal length (P < 0.01). The cranial base angle was more acute (P < 0.01) and the cross-sectional area of the cranium on lateral skull radiographs was significantly smaller (P < 0.001). However, the occipital subtenuce was larger in the fathers (P < 0.05). The craniofacial morphology in the mothers of children with CL(P) was characterized by a longer mandible (P = 0.011), an increase in the anterior facial height (P < 0.05) and greater facial length (P < 0.01). Anterior cranial base and the clivus length were also larger in the mothers (P < 0.05). The cranial parameters showed a similar trend to the paternal group with a reduced cranial area (P < 0.01) and an increase in the occipital subtenuce length (P < 0.001). Different cephalometric parameters distinguish fathers from a male comparison group and mothers from their female counterparts. An awareness of these parameters might be of value in the prediction of liability to clefting and may prove to be important in the quest for clues to the pathogenesis of both CP and CL(P).

Comparative laboratory investigation of dual-cured vs. conventional glass ionomer cements for band cementation.

This laboratory study compared the mean tensile bond strength, mode of band failure, and survival time of orthodontic bands cemented with dual-cured cement or conventional glass ionomer cement. Survival time was assessed following application of mechanical stress in a ball mill. Mean tensile bond strength was significantly higher for bands cemented with the dual-cured cement (p < 0.01), and mean survival time was significantly greater. Bands cemented with glass ionomer failed mainly at the cement/band interface. The results suggest that dual-cured cement is superior to glass ionomer for band cementation.

Laboratory evaluation of a compomer and a resin-modified glass ionomer cement for orthodontic bonding.

The mean shear debonding force of stainless steel orthodontic brackets with microetched bases bonded with either a compomer or a resin-modified glass ionomer cement was assessed. In addition, the amount of cement remaining on the enamel surface following bracket removal was evaluated. Finally, survival time of orthodontic brackets bonded with these materials was assessed following simulated mechanical stress in a ball mill. Debonding force and survival time data were compared with those obtained for brackets bonded with a chemically cured resin adhesive, a light-cured resin adhesive, and a conventional glass ionomer cement. There were no significant differences in mean shear debonding force of brackets bonded with the compomer, resin-modified glass ionomer, chemically cured resin adhesive, or the light-cured resin adhesive. Brackets bonded with a conventional glass ionomer cement had a significantly lower mean shear debonding force than that recorded for the other materials. The Adhesive Remnant Index (ARI) mode score indicated that significantly less cement remained on the enamel following debonding of brackets cemented with resin-modified or conventional glass ionomers compared with other adhesives. The median survival time for brackets cemented with the compomer, resin-modified glass ionomer, chemically cured resin, or light-cured resin were significantly longer than for brackets cemented with conventional glass ionomer. The compomer and the resin-modified glass ionomer adhesive appear to offer viable alternatives to the more commonly used resin adhesives for bracket bonding.

Home nebuliser use in children with asthma in two Scottish Health Board Areas.

OBJECTIVE: To audit the use of home nebulisers in children with asthma. DESIGN: Postal questionnaire. SETTING: Two Health Board Areas in Central Scotland--one large industrialised city, one mixed urban and rural. SUBJECTS: 297 children with asthma. MEASURES EVALUATED: Initial supply and technical support for the compressor. EDUCATION: Pattern of drug usage. SYMPTOM CONTROL: Monitoring and treatment of acute attacks. RESULTS: The full burden of the home nebulised therapy is not being met by the NHS. Supply and servicing arrangements for home nebuliser therapy were poorly organised. Chronic asthma symptoms did not appear to be optimally controlled on present medication, with 61% reporting sleep disturbance in the previous three months. About 20% of parents admitted that they would give nebulised bronchodilator therapy more frequently than the recommended 3 to 4 hourly. CONCLUSION: Re-organisation of resources and arrangements could improve the service and bring it in line with recognised standards of care.