Ventilation imaging of the lung: Comparison of hyperpolarized helium-3 MR imaging with Xe-133 scintigraphy

RATIONALE AND OBJECTIVES: To compare hyperpolarized helium-3 (HHe) magnetic resonance imaging (MRI) of the lung with standard Xe-133 lung ventilation scintigraphy. MATERIALS AND METHODS: We performed a retrospective review of 15 subjects who underwent HHe MRI and Xe-133 lung ventilation imaging. Coronal MRI sections were acquired after a single inhalation of HHe gas, and standard posterior planar lung ventilation scintigraphy was performed during continuous breathing of Xe-133 gas. The first breath scintigram of each patient was compared with a composite MR image composed of the sum of the individual MR images and with the individual helium-3 MR images. Ventilation defects on the two imaging modalities were compared for size, conspicuity, and concordance in presence and location. Assessment was done separately for each of four lung quadrants. RESULTS: Comparing the composite HHe MR images with Xe-133 scintigraphy, ventilation defect size, conspicuity and concordance were the same in 67% (40/60), 63% (38/60), and 62% (37/60) quadrants, respectively. Comparing the individual HHe MR image sections with the Xe-133 ventilation scan, there was concordance between the ventilation defects in 27% (16/60) of quadrants. More defects were identified on the individual HHe MR images in 62% (37/60) of quadrants. CONCLUSION: There was good agreement between composite HHe MR image and first breath Xe-133 scintigraphic images, supporting the widely held assumption that HHe MRI likely depicts first breath lung ventilation.     

Effects of periodic weight support in a simulated weightless environment in preventing bone demineralisation.

Anti Orthostatic Hypokinetic posture in rats by tail suspension for 15 days (d) simulates the deconditioning effects of weightlessness on the weight bearing bones. The present study evaluates the effects of daily 4 hour (h) weight support (WS) during simulated weightlessness (S-W) in preventing these changes. Adult male albino rats were divided into three groups as (i) Control (CON, n = 12), (ii) Hind limb unweighing by tail suspension for 15 d (HU, n = 18), (iii) HU with daily 4 h WS (4 HRWS, n = 11). After 15 d tibia from all the animals were removed and subsequently dried, ashed and then calcium content of the bones were determined. HU showed reductions in the water content by 35.8%, organic matrix by 12.2% and calcium content by 33.4% of tibia. 4 h WS during S-W resulted in complete prevention of water loss and organic matrix loss and partial prevention of the loss of calcium content. Calcium content of tibia in 4 HRWS remained 15.2% less as compared to CON. These findings indicate that 4 h WS is partially successful in preventing the demineralisation effects of S-W on weight bearing bone tibia.     

Distortion and size calibration of the scanning laser ophthalmoscope (SLO) laser-beam raster.

PURPOSE: The Rodenstock scanning laser ophthalmoscope (SLO) is useful for mapping retinal function and for developing and evaluating visual rehabilitation methods. It is essential to know the visual angle subtended by stimuli in the SLO laser-beam raster and to accurately measure angular distances between objects in the final SLO image. To accomplish this, the angular extent of the SLO laser-beam raster must be calibrated. METHODS: We developed a simple method and apparatus for calibrating the raster and used it for repeated calibrations during a 3-month period. RESULTS: The laser-beam raster is quite stable in shape and size, but it is trapezoidally distorted in the vertical direction. Consequently, SLO images are distorted. CONCLUSIONS: Trapezoidal distortion of the SLO laser-beam raster can cause stimulus size to change as much as 10% from the top to the bottom of the raster. Measurements of fixed horizontal retinal landmark distances in SLO images can also vary as much as 10%. We developed a straightforward mathematical method for correcting distortion in SLO image measurements.     

Welche Bedeutung kommt dem sog. negativen Lungenbefund bei der Diagnose der Augentuberkulose zu?

Ohne ZusammenfassungDie vorliegende Arbeit war als Vortrag für die abgesagte Tagung der Deutschen ophthalmologischen Gesellschaft angemeldet.Die Untersuchungen wurden mit Hilfe des Westdeutschen Tuberkulose-Forschungsinstitudes durchgeführt.     

Polyphenol content and antioxidant capacity in organic and conventional plant foods

Fruit and vegetable intake is associated with lower risk of chronic diseases as a result of consumption of antioxidant substances. Organic foods are thought to have higher antioxidant capacity, because this form of agricultural management could induce synthesis of secondary compounds such as polyphenols. The objective of this work is to evaluate polyphenol content and antioxidant capacity in organically (OG) and conventionally (CV) grown fruits and vegetables, as well as in different parts of the plants. Soluble and hydrolysable polyphenols were quantified by Folin–Ciocalteu reagent, and the antioxidant capacity was measured by the DPPH radical method. The results showed that organic fruits tend to have higher hydrolysable polyphenol contents than conventional ones, with values being 11.5% in orange peels, to 72.6% in papaya peels, higher for hydrolysable polyphenols. Fruit peels also showed higher concentration of polyphenols than pulp, reaching, for bananas and tangerines, twice the amount found in pulps, which reflected in higher antioxidant capacity. Polyphenol content and antioxidant capacity varied among organic and conventional vegetables with no prevalence from either agricultural type. This study suggests that the effect of organic practices results in different effect patterns according to the plant species analysed, with fruits being more susceptible to the induction of polyphenol synthesis, and the greatest accumulation of polyphenols in external plant tissues. In general, organic agriculture results in food products with similar or slightly higher polyphenol content and antioxidant capacity.     

Work-related recovery opportunities: testing scale properties and validity in relation to health

Objectives  

Recovery opportunities allow employees to recuperate from work and diminish load effects. The aims of this study are to present a scale for measuring recovery opportunities, study its psychometric properties and its relationship with health.     

Multiple pilocytic astrocytomas of the cerebellum in a 17-year-old patient with neurofibromatosis type I

Objective Approximately 10% of patients with neurofibromatosis I (NFI) patients will have central nervous system (CNS) tumors. The most common of these are hypothalamic–optic gliomas, followed by brainstem and cerebellar pilocytic astrocytomas. While isolated pilocytic astrocytomas in NFI are well described, the appearance of multiple pilocytic astrocytomas in an individual patient is less common. The most frequent combination in NFI patients with more than one pilocytic astrocytoma is optic tract/hypothalamic and brainstem. Other combinations are exceedingly rare; multiple pilocytic astrocytomas have only been reported once in the cerebral hemispheres in a patient with NFI. This report presents the first documented case, to our knowledge, of multiple pilocytic astrocytomas in the cerebellum of a patient with NF1. Methods Case report. Conclusion The finding of multiple cerebellar pilocytic astrocytomas in a patient with NF1 is important because it expands the spectrum of presentations for patients with NF1 and also highlights specific diagnostic and therapeutic challenges faced by the treating physicians. The genetic and molecular basis of NF1 is reviewed. Strategies of diagnosis and treatment outlined here are relevant to both patients with NF1 and all patients with multiple posterior fossa tumors.