PubMed Health⌕ Search

Biomedical subjects

B D Youl

Publications and source records attributed to B D Youl.

At least 19 recordsLinked to original sources
PubMed2006

Hyperimmune goat serum for amyotrophic lateral sclerosis.

The authors report a patient with amyotrophic lateral sclerosis (ALS) who showed a lessening of deterioration in respiratory muscle strength during treatment with hyperimmune goat serum (HGS) (Aimspro). Respiratory function tests (RFTs) were measured by established protocols, and all measurements were expressed as a percentage of normal predicted values. The rate of decline was calculated by linear regression analysis. Respiratory muscle strength decline was less during 13 months of treatment with HGS (mean 1.3% per month, range 0.8-1.7%) compared to the preceding 13 months (mean 2.3% per month, range 1.2-3.1%), while a greater decline would be expected with disease progression. Comparison with similarly affected patients in the literature suggest that a decline of 4-5% per month of predicted values may be expected during the treatment phase.

Amyotrophic Lateral Sclerosis↗
PubMed1994

Mitochondrial DNA mutation underlying Leigh's syndrome: clinical, pathological, biochemical, and genetic studies of a patient presenting with progressive myoclonic epilepsy.

An 18-year-old male patient presented with clinical and radiological evidence of Leigh's syndrome (LS), having developed progressive myoclonic epilepsy and ataxia 11 years previously. Muscle biopsy showed cytochrome oxidase deficiency but no ragged red fibres. Autopsy confirmed the diagnosis of LS; there was additional degenerative change in the cerebellum and dentate and olivary nuclei, and an axonal peripheral neuropathy. Biochemical studies showed reduced activity of complexes I and IV of the respiratory chain in mitochondria from heart, liver and kidney. The mutation of mitochondrial DNA (mtDNA) at position 8344, commonly associated with the syndrome of myoclonic epilepsy and ragged red fibres, was detected in the patient's blood and was present in muscle, brain, liver, heart, and kidney in uniformly high amounts. It is clear that LS is genetically heterogeneous and represents one of the most severe phenotypes of a number of different mtDNA defects.

Adolescent↗
PubMed1992

In vivo T1 values from guinea pig brain depend on body temperature.

T1 and T2 values were calculated from guinea pig brain in vivo at 0.5 T. T1 values showed significant dependence on body temperature, but the effect varied significantly from animal to animal and from one tissue type to another. Mean dependencies were 8.2 ms/degrees C for corpus callosum, 14.7 ms/degrees C for gray matter, and 21.5 ms/degrees C for hemispheric white matter (1.7, 2.6, and 4.5%/degrees C, respectively), all with respect to core temperature. These findings suggest that body temperature monitoring and control may be needed when sensitive measurements of T1 are being made. There was evidence for regulation of brain temperature within the hyperthermic range of body temperature.

Animals↗
PubMed1992

MRI demonstration of midbrain deformity in association with Chiari malformation.

The differentiation of Chiari malformation from intrinsic brainstem neoplasm in adults can be difficult. We report three patients presenting with brainstem signs, in whom midbrain abnormality was detected on computed tomography and interpreted as evidence of intrinsic tumour. Subsequent investigation by magnetic resonance imaging revealed evidence of Chiari I malformation in all three cases and a syrinx in two. The association of Chiari I with deformity of the midbrain or pons has not been described previously.

Aged↗
PubMed1992

Clinically isolated lesions of the type seen in multiple sclerosis: a cognitive, psychiatric, and MRI follow up study.

There is a dearth of longitudinal studies on psychometric and psychiatric change in multiple sclerosis (MS) particularly on the evolution of these abnormalities early in the disease process. A 4 1/2 year follow up study documenting magnetic resonance imaging (MRI), psychometric, and psychiatric abnormalities was undertaken in a group of 48 patients with clinically isolated lesions--for example, optic neuritis--which are frequently the harbinger of MS. At follow up about half the subjects had developed clinically definite MS, with memory deficits becoming apparent. Deficits in attention documented at initial assessment were present but unchanged in those subjects who still had a clinically isolated lesion status. However, after MS was categorised into a relapsing-remitting or chronic progressive course, patients with a chronic progressive course were found to have significantly deteriorated with regard to auditory attention tasks. T1 relaxation times in apparently normal white matter correlated with certain indices of cognitive impairment. In developing a model to explain the pathogenesis of intellectual and emotional change in MS, the interaction of organic, psychological, and social factors needs to be emphasised.

Adult↗
PubMed1991

The longstanding MS lesion. A quantitative MRI and electron microscopic study.

Important questions remain unanswered about the sequence of events leading to progressive and ultimately irreversible tissue damage in MS. This study was designed to investigate the pathological characteristics of, and function of, the blood-brain barrier within longstanding MS lesions using quantitative and Gd-DTPA enhanced MRI techniques. The ultrastructural appearances of postmortem lesions from a single, separate case of MS have been correlated with the MRI findings. Both MRI and ultrastructural analysis revealed considerable heterogeneity in the chronic lesions: some are 'closed' with no detectable extracellular water, but most are 'open' and show expansion of the extracellular space to as much as 87% of tissue area. This variable expansion probably results from differing degrees of axonal loss. Evidence of blood-brain barrier damage was found in only 17% of lesions, was less severe than that seen in acute lesions, and may result from repeated previous inflammatory insults. The findings imply progressive axonal loss in lesions as they age. It is possible that this loss is related to clinical progression of the disease.

Adult↗
PubMed1991

The pathophysiology of acute optic neuritis. An association of gadolinium leakage with clinical and electrophysiological deficits.

Eighteen patients with acute optic neuritis underwent optic nerve magnetic resonance imaging (MRI) before and after injection of gadolinium-diethylene triamine pentacetic acid (Gd-DTPA). Ten were re-examined 4 weeks later. Leakage of Gd-DTPA across the blood-optic nerve barrier was a consistent finding in the acute lesion, and its presence was associated with abnormal visual acuity and colour vision, retro-ocular pain on eye movement, and afferent pupillary defect, and a reduced amplitude of the P100 component of the visual evoked potential. Gd-DTPA leakage had ceased in 9/11 nerves when restudied 4 wks later, and this evolution was associated with improved visual acuity and an increased P100 amplitude. Leakage is likely to reflect inflammation, and we conclude that the latter plays an important part in the production of conduction block and clinical deficit, and that its resolution is an important step in clinical remission from acute episodes of demyelination.

Adolescent↗
PubMed1991

Whipple's disease confined to the CNS presenting with multiple intracerebral mass lesions.

A patient with isolated cerebral Whipple's disease presented with signs of raised intracranial pressure and multiple ring enhancing intracerebral mass lesions evident on CT and MRI imaging. Characteristic intracellular bacilliform inclusions were identified in a brain biopsy. Clinical improvement followed treatment with parenteral antibiotics for two weeks and long term sulphamethoxazole-trimethoprim. As CNS relapse of Whipple's disease may occur after several years, long term treatment should include antibiotics that are able to cross the blood-brain barrier.

Adult↗
PubMed1991

Destructive lesions in demyelinating disease.

Three cases are presented in which clinical and radiological features suggested the diagnosis of glioma but surgical biopsy revealed a demyelinating process, with tissue destruction and cyst formation in two. One patient had clinically definite multiple sclerosis. Two had probable acute disseminated encephalomyelitis. Treatment with high dose steroids is appropriate when there is clinical or investigative evidence to suggest the presence of demyelinating disease, before deciding on biopsy.

Adolescent↗