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Biomedical subjects

R J Lane

Publications and source records attributed to R J Lane.

At least 19 recordsLinked to original sources
PubMed2000

Barraquer-Simons lipodystrophy, Raynaud's phenomenon and cutaneous vasculitis.

We report a 32-year-old man who presented with a 2-year history of unexplained weight loss and symptoms of Raynaud's phenomenon. Clinical examination and investigations were consistent with a diagnosis of acquired partial lipodystrophy (Barraquer-Simons disease). This patient also exhibited an associated cutaneous vasculitis and peripheral perniotic changes. He had normal renal function and glucose tolerance and no immunological abnormality has been detected in his serum to date. The absence of C3-nephritic factor in the presence of overt lipodystrophy suggests that there may be another factor or immunological mediator responsible for the subcutaneous changes seen in patients with lipodystrophy.

Adult↗
PubMed1999

Clinical characteristics of SOD1 gene mutations in UK families with ALS.

Five to ten percent of patients with ALS have a family history of the disease, inheritance is usually autosomal dominant. Mutations of the SOD1 gene were first identified in a proportion of families with ALS by Rosen et al. The SOD1 gene encodes the enzyme copper zinc superoxide dismutase. Patients were studied from throughout the UK, where more than one individual in the family had ALS. Clinical history and examination of the individual and family were obtained, and DNA extracted from leukocytes of whole blood samples. Mutations were identified by standard sequencing methods. To date, 12 different mutations of SOD1 have been identified in 17 different families, representing around 20% of all ALS families studied. The mutations were mainly single base substitutions - H48Q, G72S, G93R, G93V, E100G, D101N, D101G, G108V, I113T, D125H, I149T - and also an insertion mutation - 132insTT - leading to a premature stop codon. The mutations were present in exons 2-5. We did not identify mutations in exon 1, although these have been identified by others in different patient samples. We have identified SOD1 mutations in around 20% of UK families with ALS studied. This is similar to that reported in other populations. Mutations have now been identified in all exons of SOD1. The individual mutations do not precisely predict disease severity, and generally it is difficult to give a specific prognosis based on the individuals' SOD1 mutations. We continue to investigate the possible pathogenic mechanisms of the SOD1 mutations. We have studied the neuropathology in patients with SOD1 mutations. We are also performing linkage studies to identify the genes involved in the 80% of families where an SOD1 mutation has not been identified.

Adult↗
PubMed1999

Dermatomyositis in association with transitional cell carcinoma of the bladder.

We report a case of dermatomyositis occurring in association with transitional cell carcinoma of the bladder. The case illustrates the importance of a thorough search for neoplasms in elderly patients with dermatomyositis and is a reminder that bladder cancer may be a rare cause of dermatomyositis. The case also shows that successful treatment of an underlying tumour may lead to resolution of paraneoplastic dermatomyositis, and relapse of cutaneous and muscle symptoms and signs may indicate recurrence of tumour.

Aged↗
PubMed1998

Heterogeneity in chronic fatigue syndrome: evidence from magnetic resonance spectroscopy of muscle.

It has been shown previously that some patients with chronic fatigue syndrome show an abnormal increase in plasma lactate following a short period of moderate exercise, in the sub-anaerobic threshold exercise test (SATET). This cannot be explained satisfactorily by the effects of 'inactivity' or 'deconditioning', and patients with abnormal lactate responses to exercise (SATET +ve) have been found to have significantly fewer Type 1 muscle fibres in quadriceps biopsies than SATET -ve patients. We performed phosphorus magnetic resonance spectroscopy on forearm muscles of 10 SATET +ve patients, 9 SATET -ve patients and 13 sedentary volunteers. There were no differences in resting spectra between these groups but at the end of exercise, intracellular pH in the SATET +ve patients was significantly lower than in both the SATET -ve cases and controls (P < 0.03), and the SATET +ve patients also showed a significantly lower ATP synthesis rate during recovery (P < 0.01), indicating impaired mitochondrial oxidative phosphorylation. These observations support other evidence which indicates that chronic fatigue syndrome is a heterogeneous disorder, and confirms the view that some chronic fatigue syndrome patients have a peripheral component to their fatigue.

Adenosine Diphosphate↗
PubMed1998

A case of multiple system atrophy with hyperglycinaemia due to a selective deficiency of glycine transporter mRNA.

A patient presented with features of olivopontocerebellar atrophy and was found to have marked hyperglycinaemia. Severe atrophy of the cerebellum and brain stem was found at post-mortem, with numerous glial cytoplasmic inclusions (GCIs) in atrophic areas, characteristic of multiple system atrophy. In situ hybridization studies of the spinal cord demonstrated a selective reduction in expression of glycine transporter mRNA. We suggest that the resulting impairment of regulation of glycine concentrations at synaptic level resulted in excitotoxic damage to neurons.

Amino Acid Transport Systems, Neutral↗
PubMed1998

Cytochrome c oxidase deficiency associated with the first stop-codon point mutation in human mtDNA.

We have identified the first stop-codon point mutation in mtDNA to be reported in association with human disease. A 36-year-old woman experienced episodes of encephalopathy accompanied by lactic acidemia and had exercise intolerance and proximal myopathy. Histochemical analysis showed that 90% of muscle fibers exhibited decreased or absent cytochrome c oxidase (COX) activity. Biochemical studies confirmed a severe isolated reduction in COX activity. Muscle immunocytochemistry revealed a pattern suggestive of a primary mtDNA defect in the COX-deficient fibers and was consistent with either reduced stability or impaired assembly of the holoenzyme. Sequence analysis of mtDNA identified a novel heteroplasmic G-->A point mutation at position 9952 in the patient's skeletal muscle, which was not detected in her leukocyte mtDNA or in that of 120 healthy controls or 60 additional patients with mitochondrial disease. This point mutation is located in the 3' end of the gene for subunit III of COX and is predicted to result in the loss of the last 13 amino acids of the highly conserved C-terminal region of this subunit. It was not detected in mtDNA extracted from leukocytes, skeletal muscle, or myoblasts of the patient's mother or her two sons, indicating that this mutation is not maternally transmitted. Single-fiber PCR studies provided direct evidence for an association between this point mutation and COX deficiency and indicated that the proportion of mutant mtDNA required to induce COX deficiency is lower than that reported for tRNA-gene point mutations. The findings reported here represent only the second case of isolated COX deficiency to be defined at the molecular genetic level and reveal a new mutational mechanism in mitochondrial disease.

Adult↗
PubMed1998

Muscle fibre characteristics and lactate responses to exercise in chronic fatigue syndrome.

OBJECTIVES: To examine the proportions of type 1 and type 2 muscle fibres and the degree of muscle fibre atrophy and hypertrophy in patients with chronic fatigue syndrome in relation to lactate responses to exercise, and to determine to what extent any abnormalities found might be due to inactivity. METHODS: Quadriceps needle muscle biopsies were obtained from 105 patients with chronic fatigue syndrome and the proportions of type 1 and 2 fibres and fibre atrophy and hypertrophy factors were determined from histochemical preparations, using a semiautomated image analysis system. Forty one randomly selected biopsies were also examined by electron microscopy. Lactate responses to exercise were measured in the subanaerobic threshold exercise test (SATET). RESULTS: Inactivity would be expected to result in a shift to type 2 fibre predominance and fibre atrophy, but type 1 predominance (23%) was more common than type 2 predominance (3%), and fibre atrophy was found in only 10.4% of cases. Patients with increased lactate responses to exercise did have significantly fewer type 1 muscle fibres (p<0.043 males, p<0.0003 females), but there was no evidence that this group was less active than the patients with normal lactate responses. No significant ultrastructural abnormalities were found. CONCLUSION: Muscle histometry in patients with chronic fatigue syndrome generally did not show the changes expected as a result of inactivity. However, patients with abnormal lactate responses to exercise had a significantly lower proportion of mitochondria rich type 1 muscle fibres.

Adult↗
PubMed1998

Familial cramp due to potassium-aggravated myotonia.

Clinical, electrophysiological, and molecular genetic features were investigated in two patients from a family a with dominantly inherited myotonic disease, characterised by painful cramps, stiffness without weakness, fluctuation of symptoms, and cold sensitivity. A reduction in amplitude of the compound muscle action potential was demonstrated on cooling and administration of potassium, although no clinical exacerbation was seen. A heterozygote mutation Val1589Met was identified in the alpha-subunit of the skeletal muscle sodium channel gene in both patients, consistent with the diagnosis of potassium-aggravated myotonia. The phenotype in this family is much milder than that previously described in another family with a mutation at this site.

Adult↗
PubMed1997

Clinical features and management of two cases of encephalitis lethargica.

Two patients with presumed encephalitis lethargica are presented with clinical features suggestive of two forms of the disease described by Von Economo: One patient had a psychosis and a mute-akinetic syndrome associated with myoclonus. The second patient presented with a psychosis and fever, developing severe dyskinesias involving the mouth, trunk and limbs, together with respiratory irregularities and presumed hypothalamic disturbance and disturbance of consciousness. In both cases, initial cerebrospinal fluid (CSF) examination revealed an elevated white cell count (predominantly lymphocytes), elevated protein in case 2, and oligoclonal bands in both cases. Computed tomography (CT) brain scan was normal but in both cases EEG revealed diffuse slow wave activity. A 18F-Dopa positron emission tomography (PET) scan in case 2 was normal. The medical management of both patients is discussed. In case 1, L-Dopa improved the akinesia, while the myoclonus responded to clonazepam. In case 2, the severe dyskinesias failed to respond to a number of drugs, and she ultimately required paralysis to relieve her almost continuous movements. Both patients responded rapidly and dramatically to intravenous methylprednisolone. We suggest that steroid treatment should be considered in the acute phase of patients with features suggestive of encephalitis lethargica.

Acyclovir↗
PubMed1997

The relationship of spinal muscular atrophy to motor neuron disease: investigation of SMN and NAIP gene deletions in sporadic and familial ALS.

Amyotrophic lateral sclerosis (ALS) is found in a familial form in around 5-10% of cases. Of these familial cases around 20% are associated with mutations of SOD-1. The genetic basis of the disease in the remaining familial cases, and genetic risk factors in sporadic cases, are unknown. Recently, the common forms of spinal muscular atrophy (SMA) have been associated with mutations of the SMN and NAIP genes on chromosome 5, in the region q11.2-13.3. Some patients with both familial and sporadic motor neuron disease show only lower motor neuron signs, in common with SMA patients, and families containing individuals with phenotypes of both childhood SMA and adult motor neuron disease have been reported. We therefore examined the SMA locus as a candidate for ALS, in 54 patients with sporadic motor neuron disease, and 10 single-generation familial patients (with no evidence of SOD-1 mutations), and in a single patient with Brown-Vialetto-Van Laere syndrome. No mutations of the SMN or NAIP genes were detected. The difficulties of classification of lower motor neuron presentations of motor neuron diseases are discussed. The demonstration that mutations diagnostic of SMA are not found in ALS patients helps distinguish these conditions.

Adult↗
PubMed1997

Limitations of intra-arterial thrombolysis.

The purpose of this study was to assess the efficacy, costs and complications of acutely ischaemic limbs initially treated with urokinase-induced thrombolysis, and to compare the subsequent patencies of occluded native arteries, vein grafts and prosthetic grafts. Data from 45 consecutive episodes of thrombolysis in 37 patients (37 limbs) were reviewed retrospectively. An initial bolus dose of urokinase was used in all limbs, with pulse-spray in nine 30 limbs received additional infusions of urokinase including six who received initial treatment with pulse-spray. Percutaneous transluminal angioplasty or surgical intervention was undertaken at any stage when considered appropriate. There were 14 occluded native arteries (31%), 12 vein grafts (27%), 16 prosthetic polytetrafluoroethylene grafts (35%), and three composite grafts (7%). Thrombolysis was initially successful in 33 episodes (73%). Of these, no additional procedure was required in three, percutaneous transluminal angioplasty in 23, other surgery in 11 and bypass surgery in seven with more than one additional procedure being undertaken in 10. Of the 12 episodes with initial failure, major surgery was performed in eight and no procedure in four. Lysis-related complications occurred in 19 treatment episodes (42%) with major bleeding in seven (16%), minor bleeding in 10 (22%), distal embolization in 11 (24%) and arterial dissection in two (4%). One amputation (2%) and one death (2%), both directly attributable to thrombolysis, occurred within 1 month of treatment. Complications occurred in 10 of 19 (53%) prosthetic or composite grafts, five of 12 (42%) vein grafts, and four of 14 (29%) native artery occlusions (P = 0.38). The median follow-up of patients remaining alive was 24 months. The overall mean (s.e.m.)patency rate at 6 months of lysed vessels or replacement bypass grafts was 44% (8%). Presentation with a native artery and or graft occlusion was associated with superior long-term patency (any subsequent conduit) compared with presentation with an occluded prosthetic graft (log rank chi2[1] = 7.00, P = 0.008) and reflects the inferior run-off of the latter patients. The average cost of thrombolysis in radiological procedures and disposables alone excluding intensive care and complications was AUD$2440.

Aged↗
PubMed1997

Histological surprise: callosal tuberculoma presenting as malignant glioma.

A tumour which on CT is clearly intrinsic, irregular, exhibits patchy enhancement with contrast, and invades periventricular tissues, especially the corpus callosum, is very likely to be a glioma and may not be biopsied. A case is presented with these radiological features in which the tumour proved to be a tuberculoma, with complete clinical and radiological resolution after antituberculous chemotherapy.

Antitubercular Agents↗
PubMed1997

Clinical and functional investigation of 10 missense mutations and a novel frameshift insertion mutation of the gene for copper-zinc superoxide dismutase in UK families with amyotrophic lateral sclerosis.

Mutations of the gene SOD-1, which encodes the enzyme copper-zinc superoxide dismutase, occur in patients with a familial form of amyotrophic lateral sclerosis (ALS). We investigated 71 families with more than one individual affected by ALS for clinical features and SOD-1 mutations. Mutations were identified in 14 families, indicating the presence of SOD-1 mutations in around 20% of this population. There were 10 different heterozygote missense point mutations in eight different codons, and a novel two-base frameshift insertion (132insTT), which leads to substitution of aspartic acid for glutamic acid at codon 132, and a premature stop codon at 133, with predicted truncation of the protein. SOD enzyme activity was reduced to around 50% of normal in individuals with SOD-1 mutations, and may be a useful predictor for the presence of these mutations. A predilection for disease onset in the lower limbs appears to be a distinguishing feature of familial ALS with SOD-1 mutations, and accords with findings in transgenic mouse models. In general, the finding of an SOD-1 mutation does not accurately predict a prognosis or disease severity.

Adult↗