Search PubMed⌕ Search

Biomedical subjects

S Chapman

Publications and source records attributed to S Chapman.

At least 235 records · Page 13Linked to original sources
PubMed1995

Imaging of childhood torticollis due to atlanto-axial rotatory fixation.

Atlanto-axial rotatory fixation is a rare cause of childhood torticollis. It may occur spontaneously or may be associated with trauma, upper respiratory tract infection or congenital abnormality of the cervical spine. Presentation is usually with persistent torticollis and "cock robin" deformity of the neck. In this paper the radiological experience in three patients is presented. Investigations included plain radiographs, plain anteroposterior tomography, CT and MRI. Displacement of the lateral mass of the atlas and the eccentric position of the odontoid peg can be seen in the plain films. CT scan can exclude fractures and confirm atlanto-axial rotation. The superimposition of CT images is demonstrated as a way of diagnosing subluxation. MRI offers better soft tissue differentiation and allows assessment of the integrity of the transverse ligament. This has an important bearing on the prognosis and may influence surgical treatment. It is important to recognise the plain film features of this uncommon condition and confirm the diagnosis with CT or MRI. The treatment options are discussed with particular reference to long term outcome.

Atlanto-Axial Joint↗
PubMed1995

Hypercalciuria and ultrasound abnormalities in children with cystinosis.

We noted microscopic haematuria in children with cystinosis. To investigate this we studied urinary calcium excretion and undertook renal ultrasound scans. Most patients had elevated urinary calcium excretion and all had abnormal appearances on ultrasound scan, ranging from increased cortical echogenicity only to those with increased cortical and medullary echogenicity. The ultrasound scan appearance was graded and correlated with laboratory parameters. It remains unclear as to the aetiology of the ultrasound findings and whether they are a consequence of treatment or a hitherto unrecognised feature of the disease.

Calcium Metabolism Disorders↗
PubMed1995

'Doing the right thing': the symbolic meanings and experiences of having an HIV antibody test.

Very few studies have been undertaken to explore in depth the reasons why individuals seek HIV antibody testing. This paper discusses the socio-cultural meanings surrounding the HIV antibody test, using the findings from a qualitative study directed at understanding why 'low risk' individuals make the decision to have an HIV test, their experiences of testing and their use of the result, especially in negotiating sexual relationships. It is concluded that the less obvious reasons for taking the test include pressure from parents or lovers, as a symbolic closure or commencement of a sexual relationship, the discourse of mutuality, the privileging of 'knowledge' and notions of responsibility and purity. Implications for AIDS education programs and policy are addressed.

AIDS Serodiagnosis↗
PubMed1995

Jellyfish green fluorescent protein as a reporter for virus infections.

The gene encoding green fluorescent protein (GFP) of Aequorea victoria was introduced into the expression cassette of a virus vector based on potato virus X (PVX). Host plants of PVX inoculated with PVX.GFP became systemically infected. Production of GFP in these plants was detected initially between 1 and 2 days postinoculation by the presence of regions on the inoculated leaf that fluoresced bright green under UV light. Subsequently, this green fluorescence was evident in systemically infected tissue. The fluorescence could be detected by several methods. The simplest of these was by looking at the UV-illuminated plants in a darkened room. The PVX.GFP-infected tissue has been analysed either by epifluorescence or confocal laser scanning microscopy. These microscopical methods allow the presence of the virus to be localized to individual infected cells. It was also possible to detect the green fluorescence by spectroscopy or by electrophoresis of extracts from infected plants. To illustrate the potential application of this reporter gene in virological studies a derivative of PVX.GFP was constructed in which the coat protein gene of PVX was replaced by GFP. Confocal laser scanning microscopy of the inoculated tissue showed that the virus was restricted to the inoculated cells thereby confirming earlier speculation that the PVX coat protein is essential for cell-to-cell movement. It is likely that GFP will be useful as a reporter gene in transgenic plants as well as in virus-infected tissue.

Animals↗
PubMed1995

Neutralizing F(ab')2 fragments of protective monoclonal antibodies to yellow fever virus (YF) envelope protein fail to protect mice against lethal YF encephalitis.

Monoclonal antibodies (MAbs) prepared against the yellow fever virus (YF) vaccine strain 17D (17D YF) envelope E protein were used to investigate Fc piece involvement in antibody-mediated protection against YF encephalitis in mice 17D YF passaged either in Vero cells or in mouse brain (P-YF) to increase neurovirulence was used. To avoid uncertainty concerning antibody clearance and blood-brain barrier penetration, and to directly compare protective activity with neutralization in vitro, pre-formed antibody-virus complexes were injected intracerebrally or assayed for plaque formation in parallel. F(ab')2 fragments of an IgG2a MAb that strongly neutralized both YF strains retained molar equivalent neutralizing activity in vitro, but did not protect. However, further incubation of such F(ab')2-virus antibody complexes with rabbit IgG, but not F(ab')2 anti-mouse IgG resulted in protection. To unambiguously test for Fc piece involvement in this model we derived an IgG2a isotype switch variant from a protective IgG1 MAb-secreting hybridoma and prepared F(ab')2 fragments of the derivative. Intact and fragmented antibodies exhibited weak neutralizing activity. The variant antibody failed to protect against P-YF, but against considerably less neurovirulent 17D YF its protective capacity was 10-fold higher than that of its IgG1 parent. F(ab')2 fragments of the variant did not protect. Together, these results provide strong evidence of an in vivo protective function for the anti-virion antibody Fc piece and indicate that in vitro neutralizing activity as a predictor of antibody protective capacity is dependent on Fc piece integrity and isotype.

Animals↗
PubMed1995

Incidental depiction of cigarettes and smoking in Australian magazines, 1990-1993.

The study aimed to assess evidence of any increase in apparently incidental photographic depictions of cigarettes or smoking in Australian magazines following the ban on tobacco advertising in the print media introduced in January 1991. We examined 27,704 pages in 20 Australian magazines popular among young people or aimed at low socioeconomic groups during three sample periods in 1990 (before the ban), 1991 and 1993 (after the ban). All photographs showing cigarettes or smoking were counted and a smoking rate per page was calculated. When all 20 magazines were combined, there was a 75 per cent increase in the rate of photographs of smoking per page from 1990 (six months before the ban) to 1991 (six months after the ban). However, there was a reduction of 36 per cent in the rate of smoking photographs per page between 1991 and 1993 (18 months after the ban) and a nonsignificant increase of 12 per cent across the three sample periods. Photographs of smoking are infrequent in Australian magazines (mean: 1:147 pages, range: 1:17 pages to zero). There appears to be a commendable constraint by many Australian magazine editors in limiting the publication of photographs that show smoking or cigarettes. Some magazines never show smoking, indicating that a goal of total absence of photographs of smoking is achievable. Some magazines have room for improvement.

Advertising↗
PubMed1995

Case report: pulmonary calcification after liver transplantation in children.

Pulmonary calcification following liver transplantation is a recognized phenomenon in adults but has not been previously described in children. We describe two children who developed pulmonary calcification after liver transplantation. Pulmonary calcification should be considered after liver transplantation when radiographic changes fail to resolve with appropriate treatment.

Calcinosis↗
PubMed1995

Smokers: why do they start--and continue?

Although smoking nauseates beginners, they are encouraged to persevere by various attractions such as its associations with maturity, glamour and friendship, as well as the evident pleasure it offers for those who overcome the body's initial revulsion. Once the pleasure is attained, addiction is the main reason for not stopping, especially when reinforced by easy availability, positive associations and the belief that quitting is terribly difficult. These facts, well known and used by the tobacco industry, also provide the basis for control strategies.

Adolescent↗