Pictorial review on abdominal applications of ferumoxytol in MR imaging

Though gadolinium-based contrast agents are the most widely used contrast media in MR for clinical use, problems with nephrogenic systemic fibrosis and tissue deposition render their safety debatable, at least in a selected patient population. Ferumoxytol has the potential to be used as an alternate contrast medium for various clinical applications across multiple organs. It has prolonged intravascular signal and delayed intracellular macrophage uptake which are unique properties compared to gadolinium-based agents. This pictorial review aims to review the current and potential clinical applications of ferumoxytol as a contrast agent in abdominal MR imaging.

     

Effects of sounds of locomotion on speech perception

Human locomotion typically creates noise, a possible consequence of which is the masking of sound signals originating in the surroundings. When walking side by side, people often subconsciously synchronize their steps. The neurophysiological and evolutionary background of this behavior is unclear. The present study investigated the potential of sound created by walking to mask perception of speech and compared the masking produced by walking in step with that produced by unsynchronized walking. The masking sound (footsteps on gravel) and the target sound (speech) were presented through the same speaker to 15 normal-hearing subjects. The original recorded walking sound was modified to mimic the sound of two individuals walking in pace or walking out of synchrony. The participants were instructed to adjust the sound level of the target sound until they could just comprehend the speech signal (“just follow conversation” or JFC level) when presented simultaneously with synchronized or unsynchronized walking sound at 40 dBA, 50 dBA, 60 dBA, or 70 dBA. Synchronized walking sounds produced slightly less masking of speech than did unsynchronized sound. The median JFC threshold in the synchronized condition was 38.5 dBA, while the corresponding value for the unsynchronized condition was 41.2 dBA. Combined results at all sound pressure levels showed an improvement in the signal-to-noise ratio (SNR) for synchronized footsteps; the median difference was 2.7 dB and the mean difference was 1.2 dB [P < 0.001, repeated-measures analysis of variance (RM-ANOVA)]. The difference was significant for masker levels of 50 dBA and 60 dBA, but not for 40 dBA or 70 dBA. This study provides evidence that synchronized walking may reduce the masking potential of footsteps.     

The effect of body position and mattress type on interface pressure in quadriplegic adults: a pilot study

A convenience sample of 20 adults with quadriplegia was studied to determine preferred position and mattress to minimize occurrence of pressure ulcers. Lower positions produced lower interface pressures. A pressure-relieving mattress reduced interface pressures more than a pressure-reducing mattress.     

Factors Associated with the Use of Fluoride Supplements and Fluoride Dentifrice by Infants and Toddlers

Dental fluorosis may be associated with the inappropriate use of fluoride dentifrices and/or dietary fluoride supplements by young children, especially for those who consume optimally fluoridated water. Studies to date have used retrospective designs that rely on anamnestic responses of adults to determine fluoride exposures in their children. The 1986 National Health Interview Survey (NHIS) collected information on current use of fluoride-containing dental products (dentifrices, drops, tablets, and mouthrinses) by all household members during home interviews. This report contains information obtained from adults for 1,996 children younger than two years of age. Nearly half of the children used fluoride dentifrices or dietary fluoride supplements. Eleven percent of the children younger than one year of age and nearly 60 percent of children between one and two years of age reportedly used a fluoride toothpaste. Dietary fluoride supplements were used about equally in these age groups (about 16%). The use of a fluoride dentif rice was similar across racial-ethnic groups, but the use of dietary fluoride supplements was less among blacks and Hispanics. A significantly higher proportion of children whose respondent knew the purpose of water fluoridation used some type of fluoride product. Because young children tend to swallow dentifrices, the findings of this study suggest the need for educational programs targeted to parents and health care providers regarding the appropriate use of fluorides and the risk of fluorosis when they are used inappropriately.