ASSESSMENT OF LACK OF FIT IN SIMPLE LINEAR REGRESSION: AN APPLICATION TO SEROLOGIC RESPONSE TO TREATMENT FOR SYPHILIS

A patient treated for infectious syphilis is cured when serologic tests become non-reactive, which may take years to achieve. Our objective is to develop a method to determine, within months, whether the patient has responded adequately to treatment. Previous research and our exploratory graphical analysis suggested that treatment response is linear when we applied logarithmic transformations of the axes. If the response to treatment is linear, titres recorded within the first few months of treatment will determine the slope of the line and one can develop an action line in future research. We used a non-parametric method to assess whether the logarithmic transformation improved the linearity and then we applied three different methods of testing lack of fit in linear regression. Based upon a sample size that reflects a clinically reasonable number of data points, the results of these tests provided no evidence against linearity. © 1997 by John Wiley & Sons, Ltd.     

Acute febrile neutrophilic dermatosis in childhood (Sweet''s syndrome)

We report a case of Sweet's syndrome in childhood. Our patients suffered from repeated fevers, chest infections and had characteristic erythematous plaques. The severity of his illness increased with age and warranted oral steroid treatment. We review 16 cases reported to date in the literature and comment on the management and prognosis of the disease in childhood.     

Depression and Estimated Functional Aerobic Capacity in Young Women: The Good and the Bad of John Henryism Active Coping

The present study assessed the moderating role of depressive symptomology in the interactive role of John Henryism (i.e., persistent striving with daily psychosocial demands) and father's educational attainment in estimated cardiorespiratory fitness in women. Two hundred one female Midwestern college students completed online psychosocial surveys. Among high‐John Henryism women who were depressed, higher father's education levels predicted better fitness. Conversely, higher father's education predicted worse fitness for nondepressed low‐John Henryism women. Depression may moderate the role of John Henryism and socioeconomic status in health, with higher John Henryism and education associated with optimal health for depressives.     

Neuroimaging in childhood arterial ischaemic stroke: evaluation of imaging modalities and aetiologies

Aim The aim of this study was to describe neuroimaging patterns associated with arterial ischaemic stroke (AIS) in childhood and to differentiate them according to stroke aetiology. Method Clinical and neuroimaging (acute and follow‐up) findings were analysed prospectively in 79 children (48 males, 31 females) aged 2 months to 15 years 8 months (median 5y 3mo) at the time of stroke by the Swiss Neuropaediatric Stroke Registry from 2000 to 2006. Results Stroke was confirmed in the acute period in 36 out of 41 children who underwent computed tomography, in 53 of 57 who underwent T2‐weighted magnetic resonance imaging (MRI) and in all 48 children who underwent diffusion‐weighted MRI. AIS occurred in the anterior cerebral artery (ACA) in 63 participants and in all cases was associated with lesions of the middle cerebral artery (MCA). The lesion was cortical–subcortical in 30 out of 63 children, cortical in 25 out of 63, and subcortical in 8 of 63 children. Among participants with AIS in the posterior circulation territory, the stroke was cortical–subcortical in 8 out of 16, cortical in 5 of 16, and thalamic in 3 out of 16 children. Interpretation AIS mainly involves the anterior circulation territory, with both the ACA and the MCA being affected. The classification of Ganesan is an appropriate population‐based classification for our Swiss cohort, but the neuroimaging pattern alone is insufficient to determine the aetiology of stroke in a paediatric population. The results show a poor correlation between lesion pattern and aetiology.     

Food Sources and Dietary Intakes of Vitamin K-1 (Phylloquinone) in the American Diet: Data From the PDA Total Diet Study

Objective To identify important food sources and estimate dietary intake of vitamin K-1 (phylloquinone) in the American diet.Design Core foods from the US Food and Drug Administration (FDA) Total Diet Study (TDS), which was based on the 1987-88 Nationwide Food Consumption Survey (NFCS), were analyzed for vitamin K-1. These nutrient values were then applied to the FDA TDS consumption model.Subjects Of the NFCS participants within the 14 selected age-gender groups, 3,634 who had 3 days of dietary data were included in the FDA TDS consumption model.Main outcome measures Vitamin K-1 intakes were estimated for each of the age-gender groups; the percentage contribution of each food item to total intake of vitamin K-1 was calculated from the FDA TDS model.Results Of the 14 age-gender groups selected, the 25- to 30-year-old women and men consumed less than the current Recommended Dietary Allowance (RDA) for vitamin K. In contrast, formula-fed infants had estimated vitamin K-1 intakes six times greater than the RDA. All other groups consumed amounts within the recommended daily intakes but lower than 90 μg/day. The top contributors to total vitamin K-1 intake were dark-green vegetables, although the fats and oils added to mixed dishes and desserts were also important contributors. The proportion of vitamin K-1 obtained from vegetables increased with age.Applications The data identify important dietary sources of vitamin K-1 in the American diet. This knowledge can be used to develop dietary assessment instruments for use in epidemiologic studies. J Am Diet Assoc. 1996; 96:149-154.     

Circadian rhythms in human performance and mood under constant conditions

This study explored the relationship between circadian performance rhythms and rhythms in rectal temperature, plasma cortisol, plasma melatonin, subjective alertness and well-being. Seventeen healthy young adults were studied under 36 h of «unmasking» conditions (constant wakeful bedrest, temporal isolation, homogenized «meals») during which rectal temperatures were measured every minute, and plasma cortisol and plasma melatonin measured every 20 min. Hourly subjective ratings of global vigour (alertness) and affect (well-being) were obtained followed by one of two performance batteries. On odd-numbered hours performance (speed and accuracy) of serial search, verbal reasoning and manual dexterity tasks was assessed. On even-numbered hours, performance (% hits, response speed) was measured at a 25–30 min visual vigilance task. Performance of all tasks (except search accuracy) showed a significant time of day variation usually with a nocturnal trough close to the trough in rectal temperature. Performance rhythms appeared not to reliably differ with working memory load. Within subjects, predominantly positive correlations emerged between good performance and higher temperatures and better subjective alertness; predominantly negative correlations between good performance and higher plasma levels of cortisol and melatonin. Temperature and cortisol rhythms correlated with slightly more performance measures (5/7) than did melatonin rhythms (4/7). Global vigour correlated about as well with performance (5/7) as did temperature, and considerably better than global affect (1/7). In conclusion: (1) between-task heterogeneity in circadian performance rhythms appeared to be absent when the sleep/wake cycle was suspended; (2) temperature (positively), cortisol and melatonin (negatively) appeared equally good as circadian correlates of performance, and (3) subjective alertness correlated with performance rhythms as well as (but not better than) body temperature, suggesting that performance rhythms were not directly mediated by rhythms in subjective alertness.     

Distal urethral electrical conductance (DUEC)—a preliminary assessment of its role as a quick screening test for incontinent women

Summary. Measurement of distal urethral electrical conductance (DUEC) has been used to detect the movement of urine along the distal urethra. DUEC was used as a screening test in 100 women attending the urodynamic clinic with incontinence and in the 33 women who voided over 250 ml, the findings correlated well with subsequent urodynamic diagnosis of urethral sphincter incompetence and detrusor instability.