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Biomedical subjects

R S Knight

Publications and source records attributed to R S Knight.

12 recordsLinked to original sources

Geographical distribution of variant CJD in the UK (excluding Northern Ireland).

BACKGROUND: The agent that causes variant Creutzfeldt-Jakob disease (variant CJD) is indistinguishable from the causative agent of bovine spongiform encephalopathy (BSE). The transmission route by which human beings are infected has not been established. One hypothesis is that cases of variant CJD have resulted from exposure to the BSE agent via rendering plants involved in the production of meat and bone meal, the main vehicle of the BSE epidemic. METHODS: We identified cases of variant CJD through the National CJD Surveillance Unit, and obtained lifetime residential histories of cases by interviewing a relative. The addresses of all rendering plants in the UK (excluding Northern Ireland) in production in 1988 were available from a survey done in that year. We calculated the distance between each case's place of residence on Jan 1, 1988, and the nearest rendering plant from postcode data, and used data from the 1991 UK census to estimate the population living within various distances of rendering plants. We compared the observed number of cases of variant CJD within a particular distance of a rendering plant with the number expected if there is no association between residential proximity to a rendering plant and the risk of developing variant CJD. FINDINGS: Up to Aug 31, 1998, 26 cases of variant CJD with onset in the UK (Northern Ireland not included) had been identified. The observed and expected numbers of variant CJD cases living within a specified distance of any rendering plant up to 50 km were almost the same. Two plants in the county of Kent each had four cases within 50 km in 1988, significantly more cases than expected (plant A, 1.04 expected; plant B, 0.74 expected). Multiple significance tests were done, so some tests would be expected to appear significant by chance alone. Computer simulations suggested that the observation of four cases of variant CJD living in an area with a population of 1.5 million (the size of Kent) is not unexpected. INTERPRETATION: There is no evidence that people with variant CJD tended to live closer than the population as a whole to rendering plants in the 1980s. The reported cluster of variant CJD cases in Kent is most probably a chance finding.

Abattoirs

Primary oral health care in black Americans: an assessment of current status and future needs.

To improve health for all in the United States by the year 2000, dental health needs must be considered a component of total health and primary care. The failure to address dental needs has reached a crisis level, particularly in the black and underserved communities throughout the nation. Data from several nationwide studies have shown that oral disease is greater in black Americans than their white counterparts. More severe periodontal disease patterns, untreated dental decay, and earlier tooth loss were observed. Key minority subgroups received less preventive care.

Black or African American

99Tcm-HMPAO single photon emission computed tomography in partial epilepsy: a preliminary report.

In the pre-operative assessment of patients being considered for temporal lobe surgery, accurate lateralization and localization of the epileptic focus is mandatory. Surface electroencephalography (EEG) can be misleading and confirmatory evidence, preferably non-invasive, of the site of the epileptic focus is valuable. Sixteen patients with partial epilepsy, six of whom were considered to be good surgical candidates, had technetium-99m hexamethylpropylene amine oxime (99Tcm-HMPAO) scanning. In those patients with poor epileptic control and a well localized EEG focus, there was a correlation between EEG and HMPAO scan abnormalities, whilst in all patients where no correlation existed, the HMPAO scan was normal. We conclude that 99Tcm-HMPAO single photon emission computed tomography may be a useful non-invasive, adjunctive investigation in the preoperative assessment of patients with partial epilepsy.

Adolescent

Progressive multifocal leucoencephalopathy and viral antibody titres.

Progressive multifocal leucoencephalopathy (PML) is caused by a papovavirus but serum antibody titres are generally considered unhelpful in clinical diagnosis because antibodies to the commonest causal agent (JC virus) are frequently found in normal adults. There is little published information about CSF titres but usually they have not been useful. Two cases of PML, confirmed by autopsy, are described where CSF antibody to JC virus was measured. In one case the JC antibody titre was significantly higher in the CSF than the serum and we suggest that this finding is diagnostically useful. In this case there was a transient stabilization of the disease following treatment with cytarabine with a change in antibody titres suggestive of reduced viral replication in the central nervous system and a host response to the infection. In the other case, which was untreated, rising serum antibody levels indicated active infection with a host response.

Adult

Neoplastic angioendotheliosis: a case of subacute dementia with unusual cerebral CT appearances and a review of the literature.

A 62 year old woman presented with subacute dementia and hemiparesis which progressed to death with terminal seizures over 5 months. A cerebral biopsy specimen and necropsy showed the features of neoplastic angioendotheliosis which proved to be lymphomatous. Cerebral CT showed multiple low density areas in the white matter with striking enhancement after high-dose intravenous contrast administration. There was temporary clinical improvement with prednisolone therapy. The clinical features, cerebral CT appearances and partial response to treatment are discussed, with a review of the relevant literature.

Brain Neoplasms

Benign intracranial hypertension: visual loss and optic nerve sheath fenestration.

Five patients with serious ocular complications of benign intracranial hypertension are described. Optic nerve sheath fenestration resulted in resolution of papilloedema with, in three instances, improvement in vision. Benign intracranial hypertension may not always be benign for vision and fenestration operations may prevent or reverse visual deterioration by an effect on the optic nerve rather than by reducing intra-cranial pressure.

Adult

Exploratory endodontic surgery.

Re-treatment of complicated endodontically treated teeth requires special consideration, particularly if the patient is unable to furnish the proper past history, such as where, when, and how the tooth in question was treated. In such cases most often more than just opening the pulp chamber and root canal(s) is required for a correct diagnosis. Under such circumstances exploratory endodontic surgery may become necessary to help determine prognosis and plan treatment. Thus, the amount of damage can be estimated and the possibility of successful treatment can be better evaluated through surgical exposure and direct visual examination of the area.

Adolescent

Long-range effects of Ivalon sponge containing isobutyl cyanoacrylates on rat tissue. A quantitative planimetric study.

This study on seventy rats was undertaken to determine the long-range effects of Ivalon sponge containing isobutyl cyanoacrylates (IBC). Histologic examination revealed that IBC sponge was well tolerated by the connective tissue. IBC sponge was most effective during the first 2 weeks of healing. At observation periods of 1 and 2 weeks, the percentage values for connective tissue formed in IBC-treated animals were 2.02 and 1.58 times higher than those in the untreated animals.

Animals