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Biomedical subjects

R O McKeran

Publications and source records attributed to R O McKeran.

At least 19 recordsLinked to original sources
PubMed1991

Mortality rates from multiple sclerosis: geographical and temporal variations revisited.

A review of the United Kingdom (UK) multiple sclerosis (MS) literature suggests that over the last three decades prevalence and estimated incidence rates have increased, while mortality rates have been declining. UK mortality data over a 30 year period have been studied to examine temporal and geographical variations, to estimate changes in survival, and to examine the relationship between mortality and morbidity trends. The study has shown an overall decline in mortality throughout the UK of approximately 25% over the 30 year period ending in 1983, and a reduction in the mortality differential between Scotland, and England and Wales, but no positive correlation has been found between mortality and morbidity. The overall decline in death rate in females was 23% and in males 30% over the 30 years of the survey. The total number of deaths declined by 39% between the five year periods 1954-58 and 1979-83 in Scotland compared with a 10% decline for England and Wales. Estimated median age of death increased from 52 to 59 years and the improvement in survival over the period of study was similar for both countries and is unlikely to have contributed to the reduction in mortality differential. Within England and Wales regional mortality rates did not show a clear north-south gradient. The decline in the mortality differential between Scotland and England (if not artefactual) may provide an important aetiological clue in the search for the cause of multiple sclerosis, and the rate of decline suggests an environmental rather than a genetic aetiology.

Adolescent↗
PubMed1990

Cerebrotendinous xanthomatosis: clinical, electrophysiological and nerve biopsy findings, and response to treatment with chenodeoxycholic acid.

A 30-year-old patient with cerebrotendinous xanthomatosis was studied over a 6-year period. The clinical manifestations were cataracts, intellectual deterioration, ataxia, palatal and pharyngeal myoclonus, corticospinal tract damage and an electrophysiologically demonstrated sensorimotor peripheral neuropathy. Peripheral motor and sensory nerve conduction velocity was slowed. Sural nerve biopsy revealed reduced densities of both myelinated and unmyelinated axons and teased fibres showed evidence of axonal regeneration and some remyelination. The loss of myelinated nerve fibres particularly affected those of larger diameter, thus contributing to the slowing of nerve conduction. Chenodeoxycholic acid treatment for two separate periods of 10 and 6 months each increased nerve conduction velocity. This electrophysiological improvement was not matched by detectable clinical neurological improvement.

Adult↗
PubMed1990

Lambert Eaton syndrome: autonomic neuropathy and inappropriate antidiuretic hormone secretion in a patient with small cell carcinoma of the lung.

A patient with small cell carcinoma of the lung developed asymptomatic autonomic neuropathy, inappropriate antidiuretic hormone (ADH) secretion and Lambert Eaton myasthenic syndrome. The autonomic neuropathy and inappropriate ADH secretion were present at the time of diagnosis of the tumour. Following chemotherapy these resolved, but 5 months later the patient developed Lambert Eaton syndrome which responded to 3,4-diaminopyridine. This sequence of changes appears to be unique.

4-Aminopyridine↗
PubMed1988

Application of radioimmunoassay to monitor treatment of human cerebral gliomas with bleomycin entrapped within liposomes.

A radioimmunoassay was assessed for its suitability for monitoring the blood and urinary concentrations of bleomycin entrapped within large unilamellar liposomes in patients receiving therapeutic doses of the drug. Bleomycin entrapped within liposomes was administered by direct intracerebral injection to three patients with grade III to IV cerebral gliomas, twice weekly for up to six weeks. No clinically important toxic effects were observed which could have been attributed to these preparations, although all three patients showed progressive deterioration in their clinical condition. This type of treatment may be more beneficial to patients at an earlier stage of their disease.

Adolescent↗
PubMed1986

Prevalence of multiple sclerosis in a south London borough.

A survey of multiple sclerosis in the London Borough of Sutton, population 169,600, yielded 195 cases, giving an overall prevalence of 115/100,000. This is the third highest prevalence for a first survey of a geographical area in the United Kingdom, exceeded only by 127/100,000 in north east Scotland and 134/100,000 in Shetland. On the classification system of Allison and Millar, three quarters of the cases were classified as probable multiple sclerosis, 15% as early probable and latent multiple sclerosis, and 10% as possible multiple sclerosis. The mean age was 49 years, the mean age at onset was 34 years, and the mean duration of the disease was 15.4 years. The age standardised female to male ratio was 2:1. The prevalence found in this survey does not differ significantly from that recorded in the first north east Scotland survey. This study suggests that, firstly, the prevalence of multiple sclerosis in south east England is probably about 100/100,000 and, secondly, the latitudinal effect on the prevalence of multiple sclerosis in the United Kingdom is less appreciable than previously believed.

Adolescent↗
PubMed1985

Studies on the intracerebral injection of vincristine free and entrapped within liposomes in the rat.

The cerebral tissue response and behaviour of rats injected with vincristine of increasing concentration, free and entrapped within liposomes was studied. In separate experiments, blood, urine and brain levels of vincristine were measured after intracerebral injection of free and liposome-entrapped vincristine. When entrapped within liposomes, vincristine clearance from the brain was significantly reduced and the amount of tissue damage was directly related to the amount of drug given, being slightly greater at the same dose when entrapped. These results indicate a potential application for drugs entrapped within liposomes acting as a depot preparation in the treatment of cerebral gliomas.

Animals↗
PubMed1985

A potential application for the intracerebral injection of drugs entrapped within liposomes in the treatment of human cerebral gliomas.

After intravenous injection of therapeutic doses of bleomycin only small amounts could be measured in glioma tissue obtained at operation in patients with malignant gliomas and the drug was rapidly cleared from the blood (T1/2 = 2 hrs). Negatively charged liposomes injected through Ommaya reservoirs into the glioma tumour bed were tolerated without observable side effect. The appearance of bleomycin in the blood and urinary clearance after intracerebral injection of bleomycin entrapped within negatively charged liposomes through an Ommaya reservoir in patients with malignant gliomas was decreased as compared with levels when free bleomycin was injected. These preliminary observations suggest a role of drugs entrapped within liposomes as a depot preparation in the treatment of human cerebral gliomas.

Bleomycin↗
PubMed1985

Neurological involvement in type 1 (adult) Gaucher's disease.

A case of type 1 (adult) Gaucher's disease with a late onset tapeto-retinal degeneration and an initially dopamine responsive extrapyramidal syndrome is described. The literature reporting neurological involvement in type 1 Gaucher's disease is reviewed, and it is concluded that the absence of symptoms and signs of nervous system involvement cannot be used as the sole basis for the classification of this type of Gaucher's disease.

Basal Ganglia Diseases↗
PubMed1985

The value of the measurement of cerebrospinal fluid levels of lysozyme in the diagnosis of neurological disease.

A turbidimetric technique has been adapted to yield maximum sensitivity for the measurement of lysozyme in cerebrospinal fluid. One hundred and ninety-eight patients were studied over a total period of 9 months using this technique. In addition to the considerably elevated levels known to occur in cases of bacterial and fungal meningitis, increased activity was also demonstrated in cases of subarachnoid haemorrhage and in certain inflammatory conditions. Normal or marginally increased levels were seen in cases of viral meningitis and encephalitis.

Bacterial Infections↗
PubMed1985

Atrial myxoma presenting with cerebral haemorrhage.

Emboli from left atrial myxomas are a recognized cause of cerebral ischaemia. The myxomatous embolus may infiltrate the cerebral arterial wall, resulting in aneurysmal dilatation with a risk of rupture. Myxoma-associated cerebral haemorrhage has been described in patients with progressive neurological dysfunction. We report a new presentation. Our patient, a previously healthy 20 year old girl, developed acute intracerebral haemorrhage for which craniotomy was performed. Histology of evacuated haematoma revealed an intravascular fragment of myxoma. Echocardiography demonstrated a left atrial myxoma which later was uneventfully excised. Early diagnosis of embolic cardiac myxoma requires awareness of the diversity of clinical manifestations, and careful histological analysis of surgical specimens.

Adult↗
PubMed1984

Studies on the use of antimitotic drugs entrapped within liposomes and of their action on a human glioma cell line.

The optimal conditions have been determined for producing the maximum incorporation within liposomes of two cell cycle-specific antimitotic drugs (bleomycin and vincristine) used in the treatment of human cerebral gliomas. Under these conditions the subsequent rate of release of these two drugs was studied in vitro. Neither cell fusion nor endocytosis could be demonstrated between liposomes of the size distribution used in these experiments (0.1-15 micron) and a human glioma cell line (U.251-MG) using a variety of marker techniques. Dose-response curves were similar for the two drugs whether free or entrapped within liposomes when applied to this cell line. These results suggest that drugs entrapped within liposomes may be useful as a potential depot preparation in the treatment of human gliomas.

Bleomycin↗
PubMed1984

Studies on the intracerebral injection of bleomycin free and entrapped within liposomes in the rat.

Reverse phase prepared liposomes of defined composition (dipalmitoyl phosphatidyl choline, cholesterol and dipalmitoyl phosphatidic acid; 7:2:1; DPC) when injected intracerebrally in the rat produced no tissue damage beyond that of the penetrating wound, or altered behaviour pattern over 1 week of observation. The cerebral tissue response and behaviour of rats injected with bleomycin of increasing concentration, free and entrapped within liposomes was studied in short and long term experiments. In separate experiments blood, urine and tissue levels of bleomycin were measured after intracerebral injection of free and liposome entrapped bleomycin in the rat. These studies demonstrated that bleomycin when entrapped within liposomes and injected intracerebrally was of low toxicity to normal cerebral tissue, and was cleared more slowly from the injection site than when the free drug was injected. The results obtained indicated a potential application for drugs entrapped within liposomes acting as a depot preparation in the treatment of cerebral gliomas.

Animals↗
PubMed1983

The tarsal tunnel syndrome in hypothyroidism.

Nine patients with myxoedema and carpal tunnel syndrome have been studied clinically and electrophysiologically to determine the presence or absence of the tarsal tunnel syndrome. Four patients had electrophysiological evidence of the tarsal tunnel syndrome, three of whom were mildly symptomatic. This would suggest that the tarsal tunnel syndrome is frequently encountered in myxoedema in association with the carpal tunnel syndrome.

Aged↗