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Biomedical subjects

R Vaughan-Jones

Publications and source records attributed to R Vaughan-Jones.

8 recordsLinked to original sources
PubMed1994

Ethmoidal sarcoidosis.

Sarcoidosis is a multisystem granulomatous disease of unknown aetiology. Nasal sarcoidosis commonly affects the mucosa of the septum and the inferior turbinates. These patients may present with nasal discharge, crusting, obstruction, epistaxis or anosmia. We present an unusual case of nasal sarcoidosis involving the ethmoid sinus causing recurrent eyelid swelling and discuss its management.

Adult↗
PubMed1992

The Welch Allyn Audioscope and Microtymp: their accuracy and that of pneumatic otoscopy, tympanometry and pure tone audiometry as predictors of otitis media with effusion.

Results of standard audiometry and tympanometry were compared with the Welch Allyn 'Audioscope' and 'Microtymp', in the diagnosis of secretory otitis media, in 100 children. Standard pure tone audiometry had a specificity of 92 per cent and sensitivity of 51.6 per cent. The Welch Allyn 'Audioscope' a specificity of 84.2 per cent and sensivity of 57.5 per cent; standard tympanometry a specificity of 71 per cent and sensitivity of 88 per cent; the Welch Allyn 'Microtymp' a specificity of 63 per cent and sensitivity of 90 per cent. In view of cost, portability, and speed of testing the Welch Allyn instruments would be particularly suitable for community screening. Pure tone audiometry with a pass threshold of 25 dB, at 2 and 4 kHz is a poor indicator of effusion.

Acoustic Impedance Tests↗
PubMed1992

A prospective study of otitis media with effusion in adults and children.

A prospective study of otitis media with effusion (OME) in both adults and children has been carried out. 75 new adult patients were seen during a 4-year period. Of these, 13 had associated diseases which could reasonably be considered to have been a cause of their effusion. Over a 2-year period, 192 new children with OME were seen. There was a significantly higher incidence of previous otalgia and/or aural discharge in the children as compared to the adults (P less than or equal to 0.001). The adults had significantly more serous effusions than the children (P less than or equal to 0.001), but both mucoid and serous effusions occurred in both groups. Similar rates of spontaneous resolution were observed in the 2 groups. Within the adult group, patients with a history of upper respiratory infection at the onset of hearing loss were significantly more likely to have spontaneous resolution of their effusion (P less than or equal to 0.02).

Adolescent↗
PubMed1991

Cadaver studies of the anatomy of arterial supply to the inferior turbinates.

The anatomy of the arterial supply of the inferior turbinate was studied by dissection and serial histological sections. The arrangement was found to be constant, with a single main descending branch of the sphenopalatine artery entering its substance from above, 1-1.5 cm from its posterior border. This artery branches as it passes forwards within the turbinate, remaining close to the bone. As these pass anteriorly they give rise to arterial arcades which remain close to or within the bone, with the main artery increasing in diameter. The implications of these findings are discussed in a surgical context.

Arteries↗
PubMed1984

Assessment of the potential uses of liposomes for lymphoscintigraphy and lymphatic drug delivery. Failure of 99m-technetium marker to represent intact liposomes in lymph nodes.

The in vivo fate of subcutaneously injected neutral SUV liposomes in rats was examined using a membrane marker, 99mTc, and an aqueous marker, 125I-labelled poly(vinyl pyrrolidone). Liposomes with entrapped 125I-labelled poly(vinyl pyrrolidone) were labelled with 99mTc by the SnCl2 method. 99mTc-radioactivity was localized several-fold more in the primary and secondary regional lymph nodes than 125I-labelled poly(vinyl pyrrolidone)-radioactivity. Similarly, 99mTc-radioactivity appeared and was subsequently cleared from the circulation much more rapidly than 125I-labelled poly(vinyl pyrrolidone). The gel chromatography of the lymph node homogenate revealed that 60-70% of 125I-labelled poly(vinyl pyrrolidone)-radioactivity was in the liposome fractions, whereas only 3% of 99mTc-radioactivity was co-eluted with the liposomes. Thus, the two markers have different fates in the lymphatics, and the presence of all 99mTc-radioactivity does not represent the 60-70% of intact liposomes present in lymph nodes. Using the aqueous marker 125I-labelled poly(vinyl pyrrolidone), the lymph node localization of positive, negative and neutral small unilamellar vesicles was studied, and it was found that 125I-radioactivity was more localized from negative liposomes than from positive liposomes, which in turn was more localized than that from neutral liposomes. Thus, these findings differ from those reported earlier, where the authors used 99mTc as a liposomal marker. In vitro studies showed that liposomes of preparations containing 20 mol% cholesterol became 'leaky' to low-molecular-weight drugs, for example, methotrexate (Mr 454) to a much greater extent than with a large-molecular-weight substance, 125I-labelled poly(vinyl pyrrolidone) (Mr 30 000-40 000), when incubated with rat lymph at 37 degrees C. Using the two markers 99mTc and 125I-labelled poly(vinyl pyrrolidone) it was found that the localization of both radioactivities was reduced in lymph nodes draining lambda-carrageenan-treated footpads. In conclusion, it is suggested that liposomes can be used for the delivery of drugs to diseased lymph nodes, and it would be worthwhile examining the possibilities of using alternative methods of labelling liposomes with 99mTc rather than using the SnCl2 technique, or using other radionuclides as markers for gamma-scan imaging.

Animals↗