Thin-section CT of the lungs: eye-tracking analysis of the visual approach to reading tiled and stacked display formats.

OBJECTIVE: To use eye-tracking analysis to identify the differences in approach to and efficiency of reading thin-section CT of the lungs presented tiled and stacked soft-copy displays. MATERIALS AND METHODS: Four chest radiologists read 16 thin-section CT examinations displayed in either a tiled (four images at once) or stacked (full screen cine) format. Eye-movements were recorded and analysed in terms of movement type; saccade distance (classified by the calculated range of useful peripheral vision), number of fixations, duration and direction of gaze-comparison of the areas of the images viewed. RESULTS: Cases presented in stacked format were read quicker than when presented in tiled format with a greater fixation frequency (5 fixations versus 4.5 fixations points per 100 data points; p<0.001) and a greater proportion of short saccades (97% versus 94%; p<0.005). The consistency with which the observers viewed equivalent areas of the scan images in different cases was greater when viewing in stacked format (mean kappa 0.45 versus 0.36; p<0.05) suggesting a more systematic approach to reading. CONCLUSION: Eye-tracking data demonstrates why thin-section CT examinations of the lungs are read more efficiently when displayed in a stack as opposed to a tiled format.

Monoclonal antibody preparation and purification of a tumor cell collagenase-stimulatory factor.

Tumor cells from several sources produce a factor(s) which stimulates fibroblast collagenase production. Monoclonal antibodies have been raised against the tumor cell collagenase-stimulatory factor from LX-1 human lung carcinoma cells and have been used for purification of the factor from LX-1 cell membranes. These purified preparations stimulated fibroblast collagenase production, and 80% of these preparations contained a single Mr approximately 58,000 protein detectable by immunoblotting; the other 20% contained an additional minor component with a molecular weight of 35,000. A single protein with a molecular weight of approximately 58,000 was also detected in radiolabeled preparations of the purified factor by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Conditioned media from LX-1 cells contain several species with molecular weights lower than 58,000 which are immunologically cross-reactive with the membrane-derived factor. Immunofluorescence analysis indicates that the tumor cell collagenase-stimulatory factor is distributed on the outer surface of LX-1 cells and is absent from the cell surface of fibroblasts. These and previous results indicate that the factor is present on the tumor cell surface, is released into conditioned media possibly after proteolytic cleavage, and appears to have an important role in inducing collagenolysis of host stroma during tumor invasion.

Pancreatic polypeptide reduces appetite and food intake in humans.

Pancreatic polypeptide (PP) is a gut hormone released from the pancreas in response to ingestion of food. Plasma PP has been shown to be reduced in conditions associated with increased food intake and elevated in anorexia nervosa. In addition peripheral administration of PP has been shown to decrease food intake in rodents. These findings suggest that PP may act as a circulating factor that regulates food intake. Therefore we investigated the effect of intravenous infusion of PP (10 pmol/kg/min) on appetite and food intake in a randomised double-blind placebo-controlled crossover study in ten healthy volunteers. Infusion of PP reduced appetite and decreased the energy intake at a buffet lunch two hours post-infusion by 21.8 +/- 5.7% (P < 0.01). More importantly the inhibition of food intake was sustained, such that energy intake, as assessed by food diaries, was significantly reduced both the evening of the study and the following morning. Overall PP infusion reduced cumulative 24-hour energy intake by 25.3 +/- 5.8%. In conclusion our data demonstrates that PP causes a sustained decrease in both appetite and food intake.

Granularity of the carotid artery intima-medial layer: reproducibility of quantification by a computer-based program.

Ultrasound of the carotid artery identifies the hypoechoic intima-medial layer (IML). Increased granularity of the IML has been associated with early atherosclerosis. The aim of the study was to assess the reproducibility and observer agreement of a computer-based program measure of IML granularity. Ten healthy adult volunteers (median age 32 years, range 18-34 years) were examined twice, 2 weeks apart, with a 7 MHz linear transducer using standardized imaging settings, by two observers. Images of both common carotid arteries were digitized and analysed on a customized computer program. The ratio (averaged over a 1 cm length of arterial wall) of the lowest pixel brightness in the IML to the maximum pixel brightness in the intima-medial interface was determined. Overall mean intima-medial reflectivity (IMR) indices for the two observers were 0.761 +/- 0.101 and 0.707 +/- 0.103, with single determination standard deviation values of 0.090 and 0.073, respectively. For interobserver calculations, the overall mean IMR index for both sessions was 0.734 +/- 0.107, with a single determination standard deviation of 0.067. Comparison with the intima-medial thickness (IMT) showed an inverse correlation (r = -0.72). This method of quantifying the reflectivity of the IML demonstrates good reproducibility in subjects with normal IMT measurements. The technique may be of value in identifying subjects at high risk of atherosclerosis but with IMT still within the normal range.

Antifungal screening of medicinal plants of British Columbian native peoples.

One hundred methanolic plant extracts were screened for antifungal activity against 9 fungal species. Eighty-one were found to have some antifungal activity and 30 extracts showed activity against 4 or more of the fungi assayed. The extracts with the greatest fungal inhibition were prepared from Alnus rubra catkins, Artemisia ludoviciana aerial parts, Artemisia tridentata aerial parts, Geum macrophyllum roots, Mahonia aquifolium roots and Moneses uniflora aerial parts. In addition to these, extracts prepared from the following plants also exhibited antifungal activity against all 9 fungi: Asarum caudatum whole plant, Balsamorhiza sagittata roots, Empetrum nigrum branches, Fragaria chiloensis leaves, Gilia aggregata aerial parts and roots, Glehnia littoralis roots, Heracleum lanatum roots, Heuchera cylindrica roots and Rhus glabra branches.

Antibiotic screening of medicinal plants of the British Columbian native peoples.

One hundred methanolic plant extracts, 96 of which had documented medicinal uses by British Columbian native peoples, were screened for antibiotic activity against 11 bacterial strains. Eighty-five percent were found to have significant antibiotic activity against at least two of the bacteria tested. Ninety-five percent of the plants categorized as potential antibiotics based on their ethnobotanical usage were found to exhibit significant antibiotic activity. Seventy-five were found to be active against methicillin-resistant Staphylococcus aureus, 46 were active against an antibiotic supersusceptible strain of Pseudomonas aeruginosa and 18 of these were also active against a wild type strain. The extracts with the broadest spectra of activity were prepared from: Alnus rubra bark and catkins, Fragaria chiloensis leaves, Moneses uniflora aerial parts, and Rhus glabra branches.

Antiviral screening of British Columbian medicinal plants.

One hundred methanolic plant extracts were screened for antiviral activity against seven viruses. Twelve extracts were found to have antiviral activity at the non-cytotoxic concentrations tested. The extracts of Rosa nutkana and Amelanchier alnifolia, both members of the Rosaceae, were very active against an enteric coronavirus. A root extract of another member of the Rosaceae, Potentilla arguta, completely inhibited respiratory syncytial virus. A Sambucus racemosa branch tip extract was also very active against respiratory syncytial virus while the inner bark extract of Oplopanax horridus partially inhibited this virus. An extract of Ipomopsis aggregata demonstrated very good activity against parainfluenza virus type 3. A Lomatium dissectum root extract completely inhibited the cytopathic effects of rotavirus. In addition to these, extracts prepared from the following plants exhibited antiviral activity against herpesvirus type 1: Cardamine angulata, Conocephalum conicum, Lysichiton americanum, Polypodium glycyrrhiza and Verbascum thapsus.

Adsorption of 222Rn by open-faced and diffusion-barrier canisters at different conditions of temperature and humidity.

Open-faced and diffusion-barrier charcoal canisters were individually exposed to a fixed temperature, humidity, and radon concentration in a chamber for a period of 7 d. The radon progeny activity in the canister under study was measured every 3 h. A total of 15 runs were made for the open-faced canisters and nine runs for the barrier canisters with temperatures and absolute humidities ranging from 15-30 degrees C and 0-15 g m-3, respectively. In addition, several runs were made with the radon, temperature, and humidity changing during the 7 d. Results show that open-faced canisters adsorb radon up to 60% more efficiently at 15 degrees C than at 30 degrees C while the barrier canisters show little temperature dependence. The barrier canisters are much less sensitive to humidity effects than the open-faced canister. When used to measure the radon concentration in air, the open-faced canister integrates over a period of only approximately 48 h while the barrier canister integrates over a period of approximately 96 h. The short integration time and the interference of water adsorption by open-faced canisters indicate that the open-faced canisters should be used for exposure times of 48 h and no longer.

Burn management. Rehabilitation.

Rehabilitation of a patient with a burn injury requires multidisciplinary collaboration, especially between the burn therapist and the burn rehabilitation nurse. Each discipline brings unique educational backgrounds and skills to promote the rehabilitation process throughout all phases of burn recovery. This article highlights major aspects of burn rehabilitation and emphasizes the collaboration between the burn therapist and the rehabilitation nurse.

Dietary intakes assessed by 24-h recalls in peri-urban African adolescents: validity of energy intake compared with estimated energy expenditure.

BACKGROUND/OBJECTIVE: The objective of this study is to determine the relative validity of reported energy intake (EI) derived from multiple 24-h recalls against estimated energy expenditure (EE(est)). Basal metabolic rate (BMR) equations and physical activity factors were incorporated to calculate EE(est). SUBJECTS/METHODS: This analysis was nested in the multidisciplinary PhysicaL Activity in the Young study with a prospective study design. Peri-urban black South African adolescents were investigated in a subsample of 131 learners (87 girls and 44 boys) from the parent study sample of 369 (211 girls and 158 boys) who had all measurements taken. Pearson correlation coefficients and Bland-Altman plots were calculated to identify the most accurate published equations to estimate BMR (P<0.05 statistically significant). EE(est) was estimated using BMR equations and estimated physical activity factors derived from Previous Day Physical Activity Recall questionnaires. After calculation of EE(est), the relative validity of reported energy intake (EI(rep)) derived from multiple 24-h recalls was tested for three data subsets using Pearson correlation coefficients. Goldberg's formula identified cut points (CPs) for under and over reporting of EI. RESULTS: Pearson correlation coefficients between calculated BMRs ranged from 0.97 to 0.99. Bland-Altman analyses showed acceptable agreement (two equations for each gender). One equation for each gender was used to calculate EE(est). Pearson correlation coefficients between EI(rep) and EE(est) for three data sets were weak, indicating poor agreement. CPs for physical activity groups showed under reporting in 87% boys and 95% girls. CONCLUSION: The 24-h recalls measured at five measurements over 2 years offered poor validity between EI(rep) and EE(est).

Estimating an Effect Size in One-Way Multivariate Analysis of Variance (MANOVA).

When two or more univariate population means are compared, the proportion of variation in the dependent variable accounted for by population group membership is eta-squared. This effect size can be generalized by using multivariate measures of association, based on the multivariate analysis of variance (MANOVA) statistics, to establish whether population mean vectors are practically significant different. In the case of random samples from populations, approximate and asymptotically unbiased estimators of these effect sizes as well as confidence intervals are suggested under the assumptions of equal covariance matrices and normality. Statistical properties of these estimators are studied by Monte Carlo simulations. The accuracy and spread of the proposed effect sizes are also compared with those of other multivariate measures of association in Monte Carlo simulations. The proposed effect sizes are also illustrated by applying them in an empirical example using college admission test data obtained from StatSoft (2007) .

The spectrum of tuberculosis and non-tuberculous mycobacterial infection.

The spectrum of radiographic findings in pulmonary infections due to M. tuberculosis (TB) and non-tuberculous mycobacteria (NTM) are being increasingly discussed, primarily as a result of the increasing prevalence of these infections. The NTM organisms are often overlooked as potential infecting organisms, diagnosis is often delayed and radiologists tend not to include NTM in their differential diagnosis. The literature on the imaging appearances of NTM pulmonary infections is now sufficiently large as to identify some features that would help to distinguish an NTM infection from conventional pulmonary tuberculosis, allowing the radiologist at least to raise the possibility of NTM infection. This review article is intended to describe the radiological features, in the immunocompetent host, that accompany TB and NTM pulmonary infections and highlight the imaging features that would favour an NTM as the causative organism.

Health professionals' guide to managing patients with Alzheimer's disease and their families.

Caring for the institutionalized patient with Alzheimer's disease is complicated by the patient's deterioration in communicating, self-care and mobility. Verbal repetition, memory aids and a set routine help maintain the patient's emotional and mental control. Regular exercise helps maintain the patient's physical well-being. Families of patients with Alzheimer's disease also need special support.