Are radiographers an influencing factor in the radiation protection practices of speech-language therapists performing videofluoroscopic swallowing studies?

INTRODUCTION: A videofluoroscopic swallowing study (VFSS) is a fluoroscopic examination conducted by radiographers and speech-language therapists (SLTs) to assess dysphagia. Given the potential of SLTs to feed patients during the procedure, they may be exposed to radiation. The research aimed to assess radiation protection practices utilised by SLTs to determine if radiographers have a role in providing ongoing practical education. METHODS: An online questionnaire was distributed to SLTs from six countries (Australia, Canada, Ireland, New Zealand, United Kingdom and United States of America). Responses were analysed quantitatively using frequencies and chi-square analysis (p = 0.05) and supported by written comments. RESULTS: A total of 224 responses were analysed. Thyroid shields (94%) were used more frequently than full aprons (72%). Differences (p < 0.0001) were seen between Australian and USA participants regarding the use and position of radiation monitors; 43% of Australian participants stating they always used a monitor, compared to 75% of USA participants. Nearly all Australian SLTs wore monitors under shielding (92%) and at waist level (69%), while USA participants reported wearing them outside shielding (97%) and at thyroid level (94%). Participants' radiation practice was influenced primarily by other SLTs (64%), followed by radiographers (57%). However, written comments revealed the significance of the radiographer in providing training as "radiographers are excellent at ensuring we [use] right equipment, stand in the right places and use exposure monitoring". CONCLUSION: SLTs did not always adopt the ICRP principle of shielding and there were inconsistencies with regards to the use and placement of radiation monitors. Radiographers are well positioned to provide advice with regards to safe practice. IMPLICATIONS FOR PRACTICE: Opportunities to enhance radiation protection practices are evident, as is the advising role of radiographers.

On-line NIR monitoring during anaerobic treatment of municipal solid waste.

An anaerobic digester (81) was fed with the organic fraction of municipal solid waste and monitored intermittently for two years with on-line near-infrared (NIR) spectroscopy and traditional chemical parameters analysed off-line. The dynamics that occurred due to changes in substrate composition (changed C:N ratio) and changes in operating conditions (overloading) could be followed using principal component analysis of the obtained NIR-spectra. In addition, process disturbances such as failed stirring and increased foaming were readily detected by the NIR-spectra. Using PLS regression the propionate concentration could be predicted in the range 0.1-3.6 g/l, RMSEP 0.53 g/l with slope 0.74 and correlation coefficient 0.85. The response on changes in the digester fluid was reproducible and could be detected within 2.5 minutes, which can be considered as real-time monitoring.

Early warning of disturbances in a laboratory-scale MSW biogas process.

The use of near-infrared spectroscopy (NIR) to monitorthe dynamics of a biogas process was evaluated using multivariate data analysis. The digester was a completely stirred 8 I tank reactor fed with the organic fraction of source-sorted MSW. Intermittently the digester was overloaded with feed. Before and after overload on-line monitoring of NIR spectra and off-line analysis in the liquid and the gas phase of traditional chemical variables and microbial biomass, determined as total concentration of phospholipid fatty acids (PLFA and PLEL), were done. The dynamics that occurred due to overloading could be followed using principal component analysis of the obtained NIR-spectra. In addition, the response to changes in the digester fluid was reproducible and could be detected within five minutes, which can be considered as real-time monitoring. Selected wavelengths in the region 800-2,000 nm were used to make a PLS1 -regression with propionate. The regression resulted in a good correlation for propionate (R= 0.94 and RMSEP of 0.21 g/l in the range of 0.3-3 g/l). The results indicate the possibility to develop an early warning biogas control system based on near-infrared spectroscopy monitoring of propionate.

Monitoring of a biogas process using electronic gas sensors and near-infrared spectroscopy (NIR).

The use of electronic gas sensors and near-infrared spectroscopy (NIR) to monitor the dynamics in a biogas process was evaluated using multivariate data analysis. The digester, a completely stirred 8 l tank reactor fed with a mixture of cellulose, albumin and minerals, was exposed to an overload of glucose after which monitoring of electronic gas sensor responses, NIR spectra as well as traditional chemical variables and analysis of microbial community structure were done. The responses from an array of electronic gas sensors consisting of MOS and MOSFET-sensors were correlated against volatile compounds in the headspace using partial least square (PLS) regressions. The root mean square error of prediction (RMSEP) was 0.15 g/l for acetate in the range of 0.14-1.72 g/l and the RMSEP for methane was 2.3% in the range of 27-73%. Selected wavelengths from the second derivative of the original NIR spectra (400-2500 nm) resulted in a PLS-model for predicting microbial biomass, measured as total phospholipid fatty acids, with a RMSEP of 9 nmol/ml in the range of 163-293 nmol/ml. The NIR model developed for acetate had a RMSEP of 0.20 g/l within the range of 0.14-1.72 g/l. The results clearly show that both NIR and an array of electronic gas sensors can provide simultaneous non-invasive in situ monitoring of important process variables in anaerobic digesters.

Feeding problems in infants with gastro-oesophageal reflux disease: a controlled study.

OBJECTIVE: Gastro-oesophageal reflux disease (GORD) in infants is commonly associated with feeding problems but has not been subject to systematic controlled study. We evaluated feeding, dietary, behavioural data obtained from systematic objective studies of six-month old infants with and without GORD. METHODS: Infants with GORD (defined by 24-h pH monitoring, n = 20), and age, gender, gestation, and socio-economic matched healthy infants (n = 20) had standardised assessments of dietary intake, oromotor function by videoanalysis (Feeding Assessment Schedule, FAS), and infant feeding behaviour by Testers and Maternal Ratings (TRIB and MRIB). Videofluoroscopic analyses of swallowing was undertaken in 11/20 GORD infants and analysed by standardised paediatric check list. RESULTS: Compared with control data: GORD infants had significantly lower energy intakes; the FAS showed GORD infants to have significantly fewer adaptive skills and readiness behaviour for solids, significantly more food refusal and food loss; the TRIB showed GORD infants to be significantly more demanding and difficult with feeds; and the MRIB revealed that mothers of GORD infants had significantly more negative feelings, significantly less enjoyment of feeds, and reported significantly more crying behaviour. On videofluoroscopy, oral-preparatory and oral phase problems predominated, particularly with solids, silent aspiration occurred during the pharyngeal phase in 2/11, and delayed oesophageal transit occurred in 4/11. CONCLUSIONS: Feeding problems affecting behaviour, swallowing, food intake, and mother-child interaction occur in infants with GORD, who displayed a lack of development of age-appropriate feeding skills. The contribution of feeding problems to morbidity in GORD in infants has been underestimated in the past.

Oral-motor dysfunction and feeding problems in infants with myelodysplasia.

Oral motor function and feeding problems have received little attention in infants with myelomeningocele (MMC). We compared objective video assessments of oral motor skills, diet and feeding function of 20 infants (aged 6 months) with MMC, with data from 20, age, gender, and socioeconomically matched healthy infants using the Feeding Assessment Schedule (FAS), Feeding Environment Check (FEC), Tester's Ratings of Infant Behaviour (TRIB), an Infant Feeding Questionnaire (IFQ), and a 24 hour dietary analysis (DQA). MMC infants had significant feeding difficulty, related to sensory motor integration problems such as hypotonicity, positioning, and hand function. Despite these problems, there was minimal behavioural disruption in infants with MMC and their mothers experienced no marked food aversion or negative feeding experiences. MMC infants consumed feedings which were significantly lower in energy than controls, with possible imbalance of other nutrients. These studies indicate that compared with healthy infants MMC infants have significantly altered oral motor function which we speculate could be early features of the Chiari II malformation. The dietary changes may reflect altered energy requirement. Early identification and management of feeding problems associated with this condition is emphasized.

Stimulation of conversion rates and bacterial activity in a silage-fed two-phase biogas process by initiating liquid recirculation.

The effects of liquid recirculation on a liquefaction-acidogenic reactor in an anaerobic two-phase digesting system operating with grass-clover silage was studied during 40 days after initiating recirculation of effluent from the methanogenic reactor to the liquefaction-acidogenic reactor. An increase in alkalinity and, thus, an increase in pH from 5.2 to 6.0 occurred in the liquefaction-acidogenic reactor. During the same period, a 10-fold increase (from 0.2 to 1.9 g.l-1.h-1) in the degradation rate of mannitol and an almost 9-fold increase in the activity of hydrogenotrophic methanogens was observed. The estimated number of these bacteria increased by one order of magnitude. The average degradation rate of lactate increased 3-fold, probably as a consequence of the more efficient hydrogen consumption by the hydrogenotrophic methanogens. An observed increase in net mineralization of organic nitrogen compounds was probably the main reason for an enhanced net production of organic acids (from 0.2 to 0.9 g.l-1.d-1). The liquefaction of cellulose and hemicellulose was low from the start of recirculation (3% and 20% reduction, respectively) and did not seem to be affected by the liquid recirculation. This was in accordance with the low number of cellulose degraders (4.0 x 10(2) counts.ml-1) observed. The results from this investigation show that the initiation of liquid recirculation in silage-fed two-phase biogas processes will stimulate the activity of hydrogenotrophic methanogens in the liquefaction-acidogenic reactor. This will lead to more thermodynamically favourable conditions for acidification reactions which are dependent upon interspecies transfer of reducing equivalents.

Migratory patterns of lac-z transfected human glioma cells in the rat brain.

Malignant brain tumors are characterized by extensive tumor-cell infiltration into the normal brain tissue. The present work describes the migratory behavior of human glioma cells transplanted into the adult rat brain with the aim of exploiting the extent of active cell migration and passive cell displacement within the central nervous system. To detect every transplanted tumor cell, a stably bacterial beta-galactosidase (lac-z) transfected human glioma cell line was used. To distinguish between an active cell migration process and passive cell displacement, rat brains were also implanted with inert fluorescent polystyrene microspheres and the distribution of tumor cells and microspheres was studied 1 hr and 3 days after implantation. One hour after implantation the tumor cells were strictly localized at the implantation site. However, 3 days after implantation, both tumor cells and microspheres showed an extensive distribution within the brain. Confirming earlier neuropathological and experimental studies, it is shown that the lac-z-transfected glioma cells had the capacity to move within the Virchow-Robin and subarachnoid spaces. However, since fluorescent microspheres were also found in these areas, this spread of tumor cells may be primarily mediated by the extensive cerebrospinal fluid flow that exists within the brain. Three days after implantation, the glioma cells also showed an active migration over the corpus callosum. In comparison, the fluorescent microspheres showed only limited spread along the callosal body. It is concluded that the bacterial lac-z gene can be stably transfected into human glioma cells and, since every tumor cell can be visualized within the brain, this model provides a tool for studying the mechanisms behind tumor-cell invasion of the brain.

Schedule for oral-motor assessment (SOMA): methods of validation.

The Schedule for Oral Motor Assessment (SOMA) was developed for the purpose of objectively rating the oral-motor skills of preverbal children, with a view to identifying areas of deficient abilities that could have clinical significance. The instrument can be administered without special equipment, by a trained observer. Oral-motor function is assessed across a range of food textures and fluids. Ratings of oral-motor skills are largely made post hoc by analysis of a videorecording of the test administration. The test-retest and interrater reliability of the instrument have been shown to be excellent. Criterion validity was investigated by means of a novel 'seeded cluster analysis' procedure in which 127 young children were assessed, most of whom were between 8 and 24 months of age. Ten percent of the sample had known abnormal oral-motor function in association with cerebral palsy (ages between 12 and 42 months). Not only was criterion validity satisfactorily established by the analysis but an abbreviated version of the SOMA--suitable for screening purposes--was developed. This has been shown to have a positive predictive validity greater than 90% and sensitivity greater than 85% for the detection of infants with clinically significant oral-motor dysfunction.

The objective rating of oral-motor functions during feeding.

The Schedule for Oral Motor Assessment (SOMA) was developed to record oral-motor skills objectively in infants between ages 8 and 24 months postnatal. Its aim is to identify areas of dysfunction that could contribute to feeding difficulties. The procedure takes approximately 20 min to administer, and is intended to be rated largely from a videorecording of a structured feeding session. A series of foodstuffs of varying textures, including liquids, is presented to the child in a standardized manner. Oral-motor skills are evaluated in terms of discrete oral-motor movements. The schedule distinguishes these from skills at more aggregated levels of functioning such as jaw, lip, and tongue control. A total of 127 children have been studied with the instrument, including normal healthy infants and samples with nonorganic failure to thrive, and cerebral palsy. Interrater and test-retest reliabilities were determined on a subset of 10 infants who each took part in three trials rated by 2 therapists. Excellent levels of interrater reliability (kappa > 0.75) were obtained for the presence/absence of 69% of discrete oral-motor behaviors. Test-retest reliability was similarly excellent for 85% of ratable behaviors. For the first time an assessment of oral-motor functioning has been shown to have adequate reliability for children aged 8-24 months. The validation of the SOMA on a large sample of normally developing infants and its application to clinical groups is presented in an accompanying paper [1].

Oral-motor dysfunction and feeding disorders of infants with Turner syndrome.

The oral-motor function of 10 infants with Turner syndrome and their age- and sex-matched controls were assessed during feeding. In addition to well-recognised dysmorphic features, including oral anomalies and high-arched palates, index infants had marked hypotonia of the cheeks and lips, dysfunctional tongue movements and poorly developed chewing skills. Their meal-times were significantly shorter than those of the controls and they weighed significantly less at six, 12 and 15 months. All mothers of infants with Turner syndrome complained of difficulties feeding their children and these problems often had been present since birth.

Behavioral style in failure-to-thrive infants: a preliminary communication.

In a pilot inner-city survey, nine 1-year-old infants with nonorganic failure to thrive (NOFT) and pairwise matched controls from the same deprived inner-city area were studied at home. A multimethod approach to the study of infant behavioral style was adopted. A consistent pattern of NOFT infants' behaviors in mothers' descriptions, in observation of play behavior, and in interaction with the examiner during standard testing emerged. NOFT infants were found to be more fussy, demanding, and unsociable. They were also less task-oriented and persistent, and their mothers expressed more negative emotions during play interaction. Mental development was significantly delayed in NOFT infants. The findings emphasize the importance of behavioral contributions from both infant and mother to the relationship problems characteristic of NOFT.

Oral-motor dysfunction and failure to thrive among inner-city infants.

Non-organic failure to thrive among socio-economically deprived inner-city infants may be associated with abnormal oral-motor functioning and aspects of social adversity, such as disorganised meal-times. A Feeding Assessment Schedule was devised to rate oral-motor behaviour objectively and was used to test nine pairs of case and comparison children while they were being fed at home. Video-recordings were made for later analysis. The case infants had immature and abnormal oral-motor development that made them less able to be fed successfully. Temperamentally they were more 'difficult' than the comparison infants, and they were less adept at signalling their needs during meal-times. The case infants also were fed in inappropriate positions for their age, with more distractions and less suitable utensils.