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Biomedical subjects

M Swash

Publications and source records attributed to M Swash.

At least 109 records · Page 6Linked to original sources
PubMed1991

Hereditary internal anal sphincter myopathy causing proctalgia fugax and constipation. A newly identified condition.

A newly identified myopathy of the internal anal sphincter is described. In the affected family, at least one member from each of five generations had severe proctalgia fugax; onset was usually in the third to fifth decades of life. Three members of the family have been studied in detail. Each had severe pain intermittently during the day and hourly during the night. Constipation was an associated symptom, in particular difficulty with rectal evacuation. Clinically the internal anal sphincter was thickened and of decreased compliance. The maximum anal canal pressure was usually increased with marked ultraslow wave activity. Anal endosonography confirmed a grossly thickened internal anal sphincter. Two patients were treated by internal anal sphincter strip myectomy; one showed marked improvement and one was relieved of the constipation but had only slight improvement of the pain. The hypertrophied muscle in two of the patients showed unique myopathic changes, consisting of vacuolar changes with periodic acid-Schiff-positive polyglycosan bodies in the smooth muscle fibers and increased endomysial fibrosis. In vitro organ-bath studies showed insensitivity of the muscle to noradrenaline, isoprenaline, carbachol, dimethylpiperazinium, and electrical-field stimulation. Immunohistochemical studies for substance P, calcitonin gene-related peptide, galanin, neuropeptide Y, and vasoactive intestinal peptide showed staining in a similar distribution to that in control tissue. A specific autosomal-dominant inherited myopathy of the internal anal sphincter that causes anal pain and constipation has been identified and characterized.

Adult↗
PubMed1991

Why is the gracilis muscle relatively uninvolved in neuromuscular disorders?

CT scanning of thigh muscles has shown that the gracilis is often relatively resistant to degeneration in neuromuscular disorders. We have compared the histometric features of the gracilis muscle with the biceps femoris and vastus lateralis muscles in the right and left thighs of 12 subjects without neuromuscular disease. There was striking variation between individuals, but marked similarities between the two limbs in individuals. The gracilis and vastus lateralis muscles contained fewer Type 1 fibres than the biceps femoris. The Type 2 fibres were slightly larger in vastus lateralis than in the other two muscles. There is thus no evident morphological difference between the gracilis muscle and other thigh muscles that can be correlated with the different susceptibility of these muscles in neuromuscular diseases. However, these muscles are subject to differing physiological stresses in movement, and these may be important in determining the response to disease.

Female↗
PubMed1991

Digital subtraction angiography (DSA) of the extracranial cerebral vessels: a direct comparison between intravenous and intra-arterial DSA.

Fifty patients being investigated for ischaemic cerebrovascular disease underwent both intravenous digital subtraction angiography (IV-DSA) and intra-arterial arch digital subtraction angiography (arch-DSA) to enable a direct comparison to be made between the two techniques. The overall quality of the images obtained by arch-DSA was better than that obtained by IV-DSA, but there was no significant difference between the number and gradation of stenoses detected by the two techniques. No significant stenosis was missed by IV-DSA and the technique was found to be sufficiently accurate for it to be used as a screening procedure for carotid bifurcation stenoses suitable for carotid endarterectomy. The advantages and limitations of both techniques are discussed.

Adult↗
PubMed1991

Ubiquitin-immunoreactive intraneuronal inclusions in amyotrophic lateral sclerosis. Morphology, distribution, and specificity.

Antibodies to ubiquitin have been used to search for evidence of abnormal protein degradation in amyotrophic lateral sclerosis--motor neuron disease (ALS). Anterior horn cell ubiquitin-immunoreactive (IR) inclusions were present in all of 31 ALS cases but in none of 23 neurologically normal and in only 1 of 22 neurologically abnormal controls. These inclusions, which were present in familial and sporadic ALS cases, and in cases with dementia, took the form of dense rounded or irregular ubiquitin-IR cytoplasmic inclusions (dense bodies), or loosely arranged bundles ('skeins') of filamentous-appearing material. The presence of ubiquitin-IR inclusions corresponded to the pattern of selective neuronal vulnerability in ALS, although inclusions in pyramidal neurons of the motor cortex were infrequent and were noted in only a minority of cases. Ubiquitin-IR inclusions were more prevalent than Bunina bodies. The latter were present in 67% of ALS cases but were seldom labelled by antibodies to ubiquitin. Intraneuronal inclusions resembling Lewy bodies were present in 23% of ALS cases and were often identified by antibodies to ubiquitin. We conclude that the presence of ubiquitin-IR inclusions in lower motor neurons represents a characteristic pathological feature of ALS in its various clinical forms. Ubiquitin-IR inclusions in ALS differ from ubiquitinated inclusions in other neuronal degenerations in that they are not readily identified by antibodies to cytoskeletal proteins. They may represent accumulations of altered or abnormal neuronal proteins resistant to degradation via the ubiquitin proteolytic pathway.

Adult↗
PubMed1991

Ubiquitin and heat shock protein expression in amyotrophic lateral sclerosis.

The expression of two heat shock proteins, HSP72 and p57, in addition to ubiquitin, has been studied immunocytochemically in nine amyotrophic lateral sclerosis (ALS) cases and 10 age-matched controls. HSP72 and p57 antibodies did not identify the characteristic ubiquitin-immunoreactive inclusions present in anterior horn cells in ALS spinal cord. Antibodies to HSP72, but not to p57 or ubiquitin, strongly labelled structures corresponding to polyglucosan bodies in spinal grey matter. Such immunoreactive profiles were more abundant in ALS cases, although they were also present in control material. They were sometimes identified by haematoxylin and eosin and periodic acid Schiff reaction, but were not labeled by phosphotungstic acid haematoxylin or by antibodies to glial fibrillary acidic protein. Although ubiquitin, HSP72 and p57 are stress-induced proteins, they are expressed differently and might therefore have different significance in neuronal degeneration.

Aged↗
PubMed1991

Stress protein inclusions in cerebral vessels in dialysis encephalopathy.

Dialysis encephalopathy, a complication of long-term haemodialysis, is a syndrome characterized by progressive dementia, myoclonus, dysarthria and ataxia associated with high serum and brain levels of aluminium. Expression of heat-shock or stress proteins, including ubiquitin can be induced in cell culture experiments by aluminium. We report immunohistochemical studies of heat shock protein (HSP) expression in the frontal cortex of three patients with dialysis dementia. Immunolabelling with antibody to the 72 kD heat shock protein revealed punctate granules in most endothelial cells of cortical vessels in patients with dialysis encephalopathy. These granules, 1-5 microns in diameter, aggregated to form inclusions that resembled stress-granules, typically induced in plant or animal cell culture by repeated insult. These granules did not express epitopes of ubiquitin. They were rare in endothelial cells in the brains of subjects dying with other neurological disorders or of non-neurological causes. We suggest that these stress granules represent a toxic response of endothelial cells in the brain to aluminium.

Adolescent↗
PubMed1991

Heat shock protein expression in corpora amylacea in the central nervous system: clues to their origin.

Small bodies expressing epitopes of the 72 kD heat shock protein (HSP) have been identified in the brain and spinal cord in normal and neurologically abnormal individuals. These bodies resemble the 'pre-corpora amylacea' (pre-CA), thought to be the primary structure in the development of the mature body. Corpora amylacea are laminated hyaline bodies composed of polyglucosans. They are found in larger numbers with increasing age in the brain and spinal cord. Mature, histologically 'classical', corpora amylacea express epitopes of HSP chiefly at the periphery of the corpus, whilst smaller immature 'pre-corpora' stain intensely throughout the entire structure. A heat shock or stress response in neurons and glial cells may be part of the cellular reaction to accumulation of abnormal products.

Adolescent↗
PubMed1991

Cyclosporin in the management of polymyositis and dermatomyositis.

Three patients with polymyositis refractory to conventional steroid and immunosuppressive treatment, but responsive to cyclosporin A, are described. In a fourth patient cyclosporin A was used as a first line drug in combination with steroids in the treatment of life-threatening dermatomyositis. Cyclosporin A in the management of polymyositis/dermatomyositis requires formal assessment of its costs and benefits compared with conventional treatments.

Adult↗
PubMed1991

Diagnosis of motor neuron disease by neurologists: a study in three countries.

Ninety four neurologists in the United Kingdom, China, and West Germany responded to two structured questionnaires. The first assessed the diagnostic weighting assigned to a number of symptoms, signs, and clinical investigations ascertained from classical descriptions and case notes of patients with motor neuron disease (MND). The second tested the likelihood and consistency of diagnosis in a series of case summaries representing the clinical data of 10 patients with clinically and pathologically documented motor neuron disease. There was a wide measure of agreement concerning the common clinical features of the disease, especially regarding fasciculation of the tongue, fasciculation associated with weakness seen in more than one limb, and dysphagia. In the case summaries, however, there was clear variation in the ranked likelihood of the diagnosis of MND and in the consistency of diagnostic behaviour in the different groups of neurologists. These findings support the need for internationally agreed criteria in the diagnosis of MND. Any such criteria will need to be tested against a standardised data set to establish their validity.

China↗
PubMed1991

Clinical trials in Alzheimer's disease. A report from the Medical Research Council Alzheimer's Disease Clinical Trials Committee.

Recent advances in Alzheimer's disease imply a need for adequate clinical trials of new treatments which require careful design. The disorder is progressive and shows clinical heterogeneity. While large-scale trials of elderly subjects are appropriate in relation to assessment of drugs or other treatments designed to prevent progression of the disorder, the outcome measurements in such biological treatment trials require careful planning. Studies of individual patients are relevant for answering certain specific questions. Relatively short cross-over trial designs may be appropriate to some pharmacological studies. The choice of neuropsychological instruments for measuring change is critically important, particularly in excluding test/retest artefact and in avoiding floor and ceiling effects. Test scales designed for assessment of specific neuropsychological deficits, or forming part of standard IQ assessments are unlikely to prove robust. Tests can be selected and developed for individual patients, but generalisation of the results of such experiments to the disease as a whole is not inevitable. There is a need to develop psychological instruments for measuring change that are robust and relevant to the clinical problem of progressive dementia.

Aged↗
PubMed1990

Small deep cerebral infarcts associated with occlusive internal carotid artery disease. A hemodynamic phenomenon?

Small deep cerebral infarcts, often referred to as lacunes, have been traditionally associated with small-vessel disease affecting the deep penetrating arterial system. We describe 10 cases where these infarcts were associated with severe, ipsilateral internal carotid artery occlusive disease. Seven of these patients also had severe occlusive disease of the contralateral internal carotid artery. The clinical and radiologic features, in combination with studies of cerebral blood flow, were consistent with hemodynamically mediated cerebral ischemia. Occlusive internal carotid artery disease may be more commonly associated with hemodynamic cerebral ischemia than previously believed, and small cerebral infarcts in the deep arterial border zone areas are likely to be an important manifestation of this process.

Adult↗
PubMed1990

The neurogenic hypothesis of stress incontinence.

There are a number of causes of incontinence. The common forms of urinary incontinence, faecal incontinence or double incontinence, are stress related, in that voiding of urine or faeces occurs in response to a sudden increase in pressure in the bladder or anorectum that is not opposed by an adequate pressure increase in the sphincteric region. This weakness of the sphincter mechanism is due to chronic partial denervation of the striated sphincter muscles of the pelvic floor, comprising the external and sphincter muscle and puborectalis (puboanalis) components of the voluntary anal sphincter musculature, and the periurethral and intramural components of the urinary striated sphincter musculature. Denervation of these muscles occurs progressively following injury initiated during childbirth and then sustained by repeated stretch-induced injury during straining behaviour at stool. Age-related changes to this innervation may also be important. Weakness of the pelvic floor, and perineal descent during straining, lead to secondary changes in the anatomy of the bladder neck, of the anorectal angle, and of the smooth muscle of the internal urinary and anal sphincters. The cystometric and anal manometric changes found in patients with stress incontinence are secondary to this neurogenic weakness of the pelvic floor.

Fecal Incontinence↗
PubMed1990

Electrically stimulated sartorius neosphincter: canine model of activation and skeletal muscle transformation.

The sartorius muscle was transposed into the abdominal cavity of six dogs, passed around a Thiry-Vella loop and sutured to itself to form a neosphincter. The muscle was activated by electrical stimulation and on contraction the neosphincter stopped or reduced the flow of saline through the Thiry-Vella loop in all animals until the onset of muscle fatigue. Continuous low frequency stimulation was used to transform the skeletal muscle, and when studied after a mean of 8 weeks of stimulation (range 6-11 weeks) the neosphincter stopped the flow for a significantly longer period of time (P = 0.027). Associated with the improved neosphincter function was a significant decrease in the fusion frequency (P = 0.003) and prolongation of the stimulus-peak tension time as assessed by a strain gauge sutured to the neosphincter muscle (P = 0.002). The changes in the contraction properties of the skeletal muscle suggest that continuous low frequency stimulation transformed the muscle fibres from type 2 to type 1, resulting in improved fatigue resistance and potential for continuous sphincter activity.

Animals↗
PubMed1990

Effect of postanal repair on progress of neurogenic damage to the pelvic floor.

Physiological evaluation of the anorectum and pelvic floor muscles was carried out in 18 patients before and 9-35 months after postanal repair for anorectal incontinence. Thirteen patients (72 per cent) were improved, but in these patients the fibre density in the external anal sphincter muscle and the pudendal nerve terminal motor latency were both increased after surgery. In the five patients not improved after surgery only a few unstable motor unit potentials could be recorded in the external anal sphincter muscle. In two of these patients the pudendal nerve terminal motor latency could not be recorded after surgery. We suggest that this progression in the neurogenic damage to the pelvic floor muscles after postanal repair may be caused by the operation, and that it may be responsible for the poor functional outcome noted in some patients.

Action Potentials↗
PubMed1990

Effect of vaginal delivery on the pelvic floor: a 5-year follow-up.

We have studied the pelvic floor musculature and its innervation in 14 of 24 (58 per cent) multiparous women who had been recruited into a study of the effect of childbirth on the pelvic floor as part of a prospective investigation that began in 1983. These 24 women had all delivered by the vaginal route without forceps assistance. Five of the 14 had developed clinical symptoms of stress incontinence 5 years later; two of them had had a further uncomplicated vaginal delivery during this time. There was manometric and neurophysiological evidence of weakness because of partial denervation of the pelvic floor striated sphincter musculature, with pudendal neuropathy, which was more marked in those women with incontinence. These findings provide direct evidence for the hypothesis that pudendal neuropathy due to vaginal delivery persists and may worsen with time.

Adult↗
PubMed1990

Carpal tunnel syndrome: which finger should be tested? An analysis of sensory conduction in digital branches of the median nerve.

Each digital branch of the median nerve was stimulated in turn in 34 women (55 hands) with carpal tunnel syndrome (CTS). The amplitude and conduction velocity of the sensory nerve action potential (SNAP) recorded at the wrist, and the threshold for patient perception of the electrical stimulus on the median innervated sides of each digit, were compared with the corresponding values in a group of asymptomatic, age-matched women. Sensory conduction velocity or SNAP amplitude were abnormal in more than 80% of all digital nerves studied apart from those in the index finger. Stimulation of digital nerves in the index finger proved the least sensitive means of detecting the electrophysiological abnormality. We conclude that selective digital nerve stimulation is a sensitive technique in the diagnosis of CTS. If ring electrodes are preferred, our results suggest that the middle rather than the index finger should be used.

Action Potentials↗