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.

Isolation and preliminary characterization of Semliki Forest virus mutants with altered pathogenicity for mouse embryos.

Four temperature-sensitive (ts) mutants of the A7 strain of Semliki Forest virus (SFV) have been isolated. All mutants were defective in RNA synthesis at the restrictive temperature (39 degrees C) compared to the permissive temperature (30 degrees C). Since the body temperature of mice fluctuates between 37 degrees C and 39 degrees C, multiplication was also examined at 37 degrees C; only the multiplication of ts4 was restricted. After intraperitoneal infection of 8-day pregnant mice, the wild-type induced rapid abortion. Ts4 and ts26 had no effect on embryonic development. Litters born to ts4-infected mothers developed no postnatal immunity whereas 50% of litters from ts26-infected mothers were immune. Unlike the wild-type, ts14 induced the same or higher virus titres in placental tissue in most mice than in foetal tissue. Ts22 and ts14 induced a range of development defects, including developmental arrest, mummification, abortion and postnatal death. Most surviving offspring were immune. Although ts4 induced no viraemia, ts14, ts22 and ts26 induced a lower titre but longer lasting viraemia than the wild-type. It is concluded that infections of pregnant mice with ts14 and ts22 in particular are good models for analysis of the mechanism of virus-induced developmental defects.

Infection of cultured early mouse embryos with Semliki Forest and rubella viruses.

Early mouse embryos at the four- to eight-cell stage or the blastocyst stage could be infected with the A7 strain of Semliki Forest virus (SFV) after the removal of the zona pellucida, either by Pronase treatment or following hatching of blastocysts. With SFV, rapid virus production and eventual cytolysis resulted from infection at either stage. For four- to eight-cell embryos the cytopathic effect was delayed and a proportion of embryos developed to the blastocyst stage. Four- and eight-cell embryos could not be infected with rubella virus (RV), even after removal of the zona pellucida. RV infection of zona-free blastocysts resulted in a productive but non-cytolytic infection which did not affect embryonic development to the early egg-cylinder stage. RV did not multiply in inner cell mass cells isolated from embryos at the blastocyst stage, although SFV did multiply in such cells.

Thoracostomy in the ICU nursery.

This paper describes chest-tube placement in a newborn with pneumothorax for the surgical resident in the ICU nursery.

Bronchopulmonary dysplasia: treatment success with dexamethasone.

A newborn infant with clinical and radiologic evidence of bronchopulmonary dysplasia was successfully managed with dramatic improvement within 36 hours of treatment with dexamethasone.As treatment of bronchopulmonary dysplasia is controversial, it is interesting to observe the clinical progress of one suggested mode of therapy with such remarkable results as illustrated in this case, particularly with radiologic follow-up.

Aberrant positioning of mediastinal mass in air space disease.

A seven-year-old black male child presented to the District of Columbia General Hospital children's emergency room with a one-day history of wheezing. A chest x-ray was obtained prior to admission to rule out foreign body or air space disease. The radiological evaluation was consistent with the clinical diagnosis of asthma.