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Biomedical subjects

L K Shield

Publications and source records attributed to L K Shield.

34 records · Page 2Linked to original sources
PubMed1988

Becker and Duchenne muscular dystrophy: a comparative morphological study.

It is important to be able to clearly differentiate between Duchenne (DMD) and Becker (BMD) muscular dystrophies in early childhood in order to offer more accurate prognostic information to parents. In response to this need, biopsies from BMD and DMD patients were compared to see which features, if any, allowed a differentiation to be made. Fifteen biopsies of vastus lateralis muscle from boys with the mild (BMD) X-linked muscular dystrophy were compared with 19 biopsies from patients with the severe (DMD) form using a variety of histochemical and morphometric parameters. Both forms showed many similarities including increases in fibre variation, percentages of Type 1 fibres, internal nuclei counts, split and fragmented fibres and groups of fibres attempting regeneration. Hypercontracted and necrotic fibres, interstitial inflammatory cells and endomysial connective tissue were more commonly increased in DMD. Fibre hypertrophy was initially prominent, particularly in DMD boys until 5 years of age and in BMD patients until approximately 10 years, thereafter the mean fibre sizes became smaller than normal. Type 2B deficiency was again common in DMD as well as occurring in some BMD cases. Nuclear aggregates and small group atrophy were more likely to be found in BMD. In the absence of morphological criteria to accurately discriminate between DMD and BMD, classification of young affected males with muscular dystrophy into one or other groups, remains a difficulty in the first decade of life.

Adolescent↗
PubMed1988

Congenital myopathies.

A retrospective review of 55 children with the clinical (pre-biopsy) suspicion of a congenital or metabolic myopathy was undertaken. After investigations, 45% remained unclassified. The only statistically significant differences between this unclassified group and the others were that males with a history of progressive disease were more likely to have a definable myopathy, while 'neuropathic' features were more common in the unclassified group.

Biopsy↗
PubMed1986

A morphometric study of human fetal sural nerve.

A morphometric study was performed on sural nerves from human fetuses at 15 to 36 weeks postovulation. There were no myelinated fibres at 15 and 16 weeks, but by 21 weeks there were 5,000/mm2, rising to 25,000/mm2 at 36 weeks. During the fetal period, the mean myelin lamellar count trebled and the g ratio (axon diameter: total fibre diameter) decreased from 0.90 to 0.75, although the axon diameter of myelinated fibres did not increase. The smallest myelinated axon diameter was 0.63 micron, whereas the largest unmyelinated axon in a 1:1 relationship with a Schwann cell was 2.83 micron, suggesting that axon size is unlikely to be the only stimulus for myelination. The density of unmyelinated axons that were the sole occupants of a Schwann cell fell considerably between 23 and 33 weeks, while the ratio of total unmyelinated axons to myelinated fibres decreased from 82:1 at 21 weeks to 6:1 at 36 weeks. Data for Schwann cell nuclear density and percentages of fibres cut through the nucleus are also presented.

Axons↗
PubMed1986

Acute transverse myelopathy in childhood.

The clinical features and outcome of idiopathic acute transverse myelopathy were reviewed for 21 children aged between seven months and 14 years. Pain, most commonly in the back, was the initial symptom for 12 patients; for another six it was weakness and for two urinary retention. All patients had weakness of the legs, and 11 had arm weakness as well. Five patients had very acute onset of severe weakness and were unable to walk within three hours of onset of symptoms. Two children made no significant recovery; for the remainder onset of recovery was evident within two to 17 days. 12 patients later were normal or had only minimal neurological deficit, but nine had a poor outcome with major disturbance of motor or sphincter function. Only one of the five with very acute onset had a good outcome. Over-all, the prognosis after acute transverse myelopathy in childhood is a little better than that reported for adults.

Adolescent↗
PubMed1981

Subacute cholinergic dysautonomia in childhood.

Clinical features of a 10-year-old boy who presented with manifestations of subacute autonomic neuropathy are described. The pupillary abnormalities, reduced tear, sweat and saliva production, and visceral dysfunction suggest a lesion restricted to cholinergic postganglionic endings of the autonomic nervous system. There was no evidence of dysfunction at the neuromuscular junction or elsewhere in the nervous system. The cause of the cholinergic dysautonomia has not been found. Clostridium botulinum infection could not be verified, and although a variety of Clostridium species were isolated from the faeces they could not be shown to produce a neurotoxin.

Autonomic Fibers, Postganglionic↗
PubMed1977

Methyl bromide intoxication: neurologic features, including simulation of Reye syndrome.

Three family members intoxicated with methyl bromide presented with a variety of neuropsychiatric manifestations including coma, severe status epilepticus, hyporeflexia, and acute psychosis. The simulation of Reye syndrome in the child emphasizes the need for careful toxicologic screening of all children presenting with this syndrome. The initial diagnostic difficulty encountered in these cases emphasizes the need for heightened awareness of the toxic chemicals used in local industries and the clinical manifestations of their intoxication.

Adult↗
PubMed1976

Late-infantile neuronal ceroid-lipofuscinosis. An ultrastructural study of lymphocyte inclusions.

Ultrastructural study of peripheral blood from two patients with late-infantile neuronal ceroid-lipofuscinosis with curvilinear bodies, demonstrated in brain biopsies revealed curvilinear bodies in lymphocytes. These findings indicate that ultrastructural investigation of circulating lymphocytes may be useful in the diagnosis of late-infantile neuronal ceroid-lipofuscinosis and may circumvent the need for brain biopsy. Curvilinear bodies were also present in the lymphocytes of a neurologically normal younger female sibling of patient 1, who has had a single seizure, leading to speculation that she may be in the early stages of the same disease. This case suggests the possibility of early detection of this disorder and indicates the importance of screening lymphocytes of siblings of affected patients. Tubular cytoplasm inclusions were present in a high percentage of lymphocytes of the asymptomatic parents and a younger sibling of these patients.

Cerebral Cortex↗
PubMed1976

Transillumination of the skull in premature infants.

Transillumination of the skull in infants is a simple technique which can be used to detect several major abnormalities of the central nervous system. The usefulness of transillumination has been limited, however, by the lack of standard techniques for its performance and by the absence of normal values, especially in premature infants. In healthy premature infants, there is a progressive increase in transillumination with increasing gestational age over three sites--the anterior fontanelle, the frontotemporal fossa, and the parieto-occipital eminence.

Analysis of Variance↗
PubMedDate not supplied

Ictal 99mTc-HMPAO single photon emission computed tomography in children with temporal lobe epilepsy.

Seventeen ictal 99mTc-HMPAO single photon emission computed tomography (SPECT) studies were performed in 15 children with temporal lobe epilepsy (TLE) aged 7-14 years (mean 10.3 years). Ictal SPECT was informative in 16 of 17 (94%) studies in 14 of 15 (93%) children, showing unilateral temporal lobe hyperperfusion. In all 16 informative ictal SPECT studies, lateralization was concordant with ictal EEG, magnetic resonance imaging (MRI), and pathology. In 4 children, ictal SPECT provided additional localizing information that was not apparent from concurrent ictal EEG recording. Blinded interpretation of ictal SPECT studies by two independent investigators showed correct lateralization of the epileptic focus in every child. Results of visual analysis of ictal SPECT images were corroborated by quantitative analysis. Although interictal SPECT studies showed a degree of temporal lobe hypoperfusion in all children, in 9 of 15 hypoperfusion was either minimal, bilateral, contralateral, or associated with extratemporal hypoperfusion. In children with TLE, ictal SPECT provides reliable lateralizing information to corroborate or supplement that obtained from surface EEG and MRI.

Adolescent↗