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Biomedical subjects

D A Francis

Publications and source records attributed to D A Francis.

At least 19 recordsLinked to original sources
PubMed1992

The site of brainstem lesions causing semicircular canal paresis: an MRI study.

Ten patients with canal paresis of central origin and ten patients with peripheral canal paresis were studied using MRI of the brainstem to identify lesions within the central vestibular pathways. In the central group, the magnitude of the canal paresis was generally lower than in the peripheral group and removal of fixation had little effect on the nystagmic response. In the peripheral group, removal of fixation enhanced the nystagmus and lessened the discrepancy between the two ears. Statistical processing of the MRI showed that in the central group significant spatially coincident lesions occurred within the medial vestibular nucleus, lateral vestibular nucleus and proximal portion of the vestibular fascicle.

Adult↗
PubMed1991

An assessment of disability rating scales used in multiple sclerosis.

Twenty patients with clinically definite, stable multiple sclerosis were examined independently by three of us at the same visit and given scores on the Ambulation Index, Expanded Disability Status Scale, and Kurtzke Functional System scales. Observer error accounted for 12% to 55% of the variation observed between individual Kurtzke Functional System scores, 17.1% of the variation observed between the patients' Expanded Disability Status Scale scores, and only 3.9% of the variation between Ambulation Index scores. The implications of these findings for the choice of scales in clinical trials are described.

Adult↗
PubMed1991

Multiple sclerosis and HLA: is the susceptibility gene really HLA-DR or -DQ?

Seventy-one patients with multiple sclerosis (MS) were classified into four subgroups according to the clinical pattern of their disease; their HLA-DR and DQ polymorphisms were defined by serological methods and analysis of Taq1 digestion fragments hybridizing with DRB, DQA, and DQB cDNA probes. The frequencies of the polymorphisms in the patients were compared with those of 100 control subjects. The frequencies of a 3.25-kb fragment from Mspl digests of genomic DNA which hybridized to DQA were also defined in the same groups of patients and control subjects. HLA-DR2 (DRw 15 subtype) and the associated HLA-DQw6 were observed in significant excess in the patients compared with the normal subjects (63% vs. 32% for DRw15; 65% vs. 42% for DQw6). There were no significant differences in the distribution of the DR or DQ alleles between the groups of patients showing different clinical patterns of disease, nor was there an excess in the patients of DQw8 and DQw9 which share hypervariable region sequences of the DQB chain in common with DQw6. The results argue against two recently proposed hypotheses of MS. First, they are not consistent with the proposal that susceptibility to MS is associated with expression of a hypervariable region of DQB shared by DQw6, 8, and 9. Second, they do not support the concept that primarily chronic progressive and relapsing/remitting MS are two immunogenetically distinct disease entities. Our evidence is consistent with the hypothesis that one of the true disease susceptibility genes for MS lies elsewhere within the HLA region and in Northern European populations is found in significant association with DRw15 and DQw6.

Adult↗
PubMed1991

Demyelinating optic neuritis: clinical features and differential diagnosis.

Optic neuritis is a common cause of sudden visual impairment in young adults. Early recognition by the clinician would alleviate much of the anxiety experienced by sufferers, but other conditions that may cause permanent blindness must be excluded. These can usually be discerned from the history and confirmed by a brief neuro-ophthalmological examination.

Color Perception↗
PubMed1989

An allelic cluster of DQ alpha restriction fragments is associated with multiple sclerosis: evidence that a second haplotype may influence disease susceptibility.

Extensive analysis of restriction fragment length polymorphism using HLA class II and T-cell receptor gene probes has been carried out in an attempt to identify genetic markers more strongly associated with multiple sclerosis than the classically defined antigens DR2, Dw2, and DQw1. The use of DNA pooled from groups of patients and controls from northeast Scotland enabled the screening of 14 restriction endonucleases with five HLA-D region probes (DP alpha, DP beta, DQ alpha, DQ beta, DR beta) and two T-cell antigen receptor probes. Restriction fragment length polymorphisms which discriminated between multiple sclerosis and control pools were identified with four restriction enzymes: Msp1 (DQ alpha), BamH1, Bgl11, and Taq1 (DQ beta). No discriminatory polymorphism was seen with any of the other enzyme/probe combinations. Subsequent Southern blot analysis of individual DNA samples was carried out using these enzymes and probes in two independently conducted studies, in Northern Ireland and northeast Scotland. Following Msp1-digestion and hybridization to DQ alpha, a 3.25-kb fragment was observed in 31% of Scottish patients but in only 4% of controls from the same population. Furthermore, when only DR2-positive individuals were analyzed, there was a significant excess of this fragment in patients from both Scotland (28, or 2.9%) and Northern Ireland (20, or 3.4%). Although the DQ alpha gene characterized by this fragment remains to be determined, this fragment exhibits apparent allelism to DQw1. Therefore, these data raise the possibility that two different DQ alleles, one on each haplotype, may jointly contribute to disease susceptibility.

Alleles↗
PubMed1989

Burns management and junior staff--what do they know?

This study examines the ability of junior doctors to initiate the management of burned patients. One hundred and twenty-four junior doctors were assessed using a questionnaire. Eighty per cent of the sample had had undergraduate lectures on the subject and 43 per cent had experience of managing patients with major burns. Despite this only 3 per cent could correctly carry out all the steps necessary to estimate the fluid requirements of a burned patient. Theoretical knowledge of the 'Rule of Nines' was adequate but 10 per cent of the sample made mathematical errors when supplied with a burns formula and the appropriate values. We suggest that postgraduate instruction be given to junior staff and that burns charts include details of a burns formula and an illustrative example of the calculation required.

Burns↗
PubMed1989

Ocular inflammatory changes in established multiple sclerosis.

Fifty consecutive patients with clinically definite multiple sclerosis were studied to assess the prevalence of concomitant uveitis. Asymptomatic ocular inflammatory changes were found in nine patients (18%) and appeared to show a positive correlation with severe and progressive disease. Conversely uveitis was uncommon in the presence of established optic atrophy which suggests a negative influence on its pathogenesis. In the absence of optic atrophy inflammatory changes in the eye may be a valuable index of disease activity.

Adolescent↗
PubMed1989

Haplotypes and MS.

Explore the source record for details and available documents.

HLA-DR2 Antigen↗
PubMed1988

MRI appearances of the CNS manifestations of Mycoplasma pneumoniae: a report of two cases.

Two patients are reported with Mycoplasma pneumoniae-related cervical myelitis. Magnetic resonance imaging in each case demonstrated clinically silent lesions suggesting more extensive neurological involvement. This supports the concept of widespread immunologically mediated disease occurring as a remote effect of initial M. pneumoniae respiratory infection. Differences from the MRI appearances of a patient with mycoplasma-related Guillian-Barré syndrome imply that more than one antigenic determinant is involved.

Adolescent↗
PubMed1988

Recovery after optic neuritis in childhood.

Thirty-nine children who presented with optic neuritis in childhood were reviewed after a follow up period from 3 months to 29 years (mean 8.8 years). At follow-up, 30 out of 39 (77%) of the children had had no further episodes and in three (8%) there was recurrence of optic neuritis alone. Multiple sclerosis had developed in six patients (15%), a much lower frequency than after optic neuritis in adult life. Regardless of the initial degree of visual impairment or neurological outcome, the visual prognosis was excellent. Pattern evoked potentials at follow-up were much more frequently normal (55%) than in adults (10%) after optic neuritis.

Adolescent↗
PubMed1988

Cerebral depression due to propylene glycol in a patient with chronic epilepsy--the value of the plasma osmolal gap in diagnosis.

A case of propylene glycol poisoning is described in a 39 year old woman which resulted in her admission to hospital in status epilepticus. She had had a long-standing history of uncontrollable epilepsy. The diagnosis of propylene glycol poisoning resulted directly from the finding of a high plasma osmolal gap on admission. This finding would have been missed if later samples only had been analysed. Plasma osmolality and the osmolal gap should be considered first line investigations in patients presenting with metabolic acidosis and cerebral signs and symptoms. Since her discharge from hospital a year ago the patient has had no further seizures.

Acidosis↗
PubMed1987

Nisoldipine in primary Raynaud's phenomenon.

The efficacy and tolerability of the dihydropyridine derivative nisoldipine was assessed in 36 patients with primary Raynaud's phenomenon. Nisoldipine was given at doses of 5 mg and 10 mg daily for one month each in a placebo controlled double-blind cross-over trial. There was no subjective improvement in symptoms or changes in resting finger blood flow, platelet aggregability or red cell deformability after nisoldipine. The incidence of unwanted effects was similar to that previously described with nifedipine, suggesting that plasma concentrations of nisoldipine were sufficient to cause pharmacodynamic effects. Nisoldipine, in contrast to nifedipine is ineffective in the treatment of primary Raynaud's phenomen when given in a dose of up to 10 mg/day.

Adult↗
PubMed1987

Multiple sclerosis in north-east Scotland. An association with HLA-DQw1.

This study reports the frequencies of HLA antigens and the polymorphic variants of C4, C2, and Bf for 200 patients with multiple sclerosis (MS) living in the Grampian region of Scotland, an area of high disease prevalence. A group of 128 normal subjects from the same region were typed for comparison. Although the frequencies of HLA-B7 and DR2 in the patient group (43.3% and 49.4%, respectively) were found to be similar to those reported for other Northern European HLA studies on patients with MS, high frequencies of these antigens were also observed in the group of normal Grampian subjects (38.3% and 40.6%) the differences were not statistically significant. However, a significant association was found between the recently defined Class II HLA antigen, DQw1, and MS (P less than 0.006) when compared with controls. There were no significant differences in frequency of the polymorphisms of C4, C2, and Bf when the group of patients with MS was compared with the control group of normal subjects. The patients were subdivided according to disease severity, remittent versus progressive clinical course, age of onset of the disease and initial symptoms. The frequencies of the HLA and complement polymorphisms (C4, C2, and Bf) were analysed in these subdivisions. DQw1 was found with similar frequency in severe and benign disease (78% and 80%, respectively) but DR2 was most frequent in the group of patients with remittent disease (54%). There were no significant differences in frequency of the polymorphisms of C4, C2, and Bf between the above subgroups of patients and overall no significant HLA associations were found with age of onset of disease or initial symptoms. The findings suggest that in an area of high prevalence of MS, the disease is more closely associated with DQw1 than DR2. Furthermore, there was no evidence to support the hypothesis that the HLA region complement gene polymorphisms show significant association with a putative HLA-linked MS susceptibility gene.

Complement C4↗
PubMed1987

Retinal venous sheathing in optic neuritis. Its significance for the pathogenesis of multiple sclerosis.

A systematic study of the frequency of retinal vascular abnormalities and cells in the media has been made in 50 patients presenting with acute optic neuritis. Abnormalities were found in 14 (fluorescein leakage in 10, perivenous sheathing in 6, cells in the vitreous in 6 and in the anterior chamber in 4; in 2 the cells in the media were seen without vascular changes). After a mean follow up of 3.5 years multiple sclerosis (MS) had developed in 8/14 patients with vascular abnormalities and/or evidence of inflammation and in 5/32 without; the difference is significant (P less than 0.02). The occurrence of perivenular abnormalities in a region free of myelin and oligodendrocytes provides evidence that the vascular changes in MS can occur independently of contiguous demyelination, and may be the primary event in the formation of a new lesion.

Adolescent↗
PubMed1987

A reassessment of the risk of multiple sclerosis developing in patients with optic neuritis after extended follow-up.

One hundred and one of 146 patients presenting with isolated idiopathic optic neuritis, previously reviewed in 1978, were reassessed clinically, and retyped for HLA antigens and Factor B alleles, after a mean follow-up of 11.6 years. Fifty eight patients (57%) had developed multiple sclerosis at the time of reassessment in the present study, of whom 51 (88%) had clinically definite disease. This compared with 40% of the original group, in 1978, of whom 62% then had clinically definite multiple sclerosis. When the life-table method of analysis was used, the probability of developing multiple sclerosis was 75%, 15 years after the initial episode of optic neuritis. The frequencies of HLA-DR2 and the recently defined D-region antigen, DQw1, were significantly increased in patients with isolated optic neuritis and those who subsequently developed multiple sclerosis compared with normal controls, but neither allele appears to influence progression from optic neuritis to multiple sclerosis. Patients with optic neuritis who were HLA-DR3 positive had an increased risk for the development of multiple sclerosis (RR = 2.8) and this risk was further enhanced when DR3 occurred in combination with DR2 (RR = 6.7). The overall increased risk of developing multiple sclerosis for patients with this combination was 26 times that for the normal population. When the patients' original tissue-typing was considered BT 101 no longer influenced conversion of optic neuritis to multiple sclerosis. This may partly be explained by improved methods of tissue-typing, since not all BT 101 patients were subsequently found to be positive for HLA-DR2 or HLA-DQw1 and vice versa and by extended follow-up as multiple sclerosis conversion in HLA-DR2 negative individuals increased with time. All 101 patients were typed for Factor B alleles. No significant differences in frequencies were found between individuals with isolated optic neuritis or those who progressed to multiple sclerosis compared with the control population. Recurrent episodes of optic neuritis were associated with an increased risk for the development of multiple sclerosis in this study.

Adolescent↗
PubMed1987

HLA genetic determinants in familial MS. A study from the Grampian region of Scotland.

Fourteen multiplex MS families, 9 single-case MS families and 11 normal families from the Grampian region of North-East Scotland were studied. The prevalence rate of MS for individuals in multiplex families was calculated at 809/100,000; 4.5 times the prevalence rate for the general population in this region. The distribution of shared haplotypes in 12 affected and 19 unaffected sib-pair comparisons did not differ significantly from that expected by chance. Furthermore there was no evidence that homozygosity of a particular HLA gene was required for increased susceptibility to the disease. HLA-B7, C4A3, C4B1, BfS, HLA-DR2, HLA-DQw1 was the commonest haplotype accounting for 18.9% and 24.2% of parental haplotypes from multiplex and single-case families, respectively, compared with 2.3% of parental haplotypes from control families (p less than 0.05 and p less than 0.01, respectively). No significant differences were observed in the frequencies of complement gene polymorphisms (Factor B and C4). The data suggests that a MS susceptibility gene exists, in the HLA complex, and is in closest linkage disequilibrium with the HLA-D region; although other factors, environmental and/or independent genetic loci, may have an important influence.

HLA Antigens↗