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Biomedical subjects

P Edmond

Publications and source records attributed to P Edmond.

At least 19 recordsLinked to original sources

The application of air bag technology: an objective clinical measure of involuntary muscle spasm.

OBJECTIVES: To develop a technique which could objectively monitor and quantify spasms in spinal cord injured persons. METHODS: This technique used accelerometers to detect movements in the limb caused by spasms. Accelerometer signals from movements caused by spasms and a variety of movements caused by other subject activities (movement in a wheelchair, transfers etc) were recorded and linear discriminant analysis was used to distinguish between spasms and other activities. Individual spasms were quantified by their duration, magnitude and energy and were recorded over a 24-h period. RESULTS: Limb movements caused by spasms were shown to be well correlated with the EMG activity of the muscles causing the movement. Movements caused by spasms and movements caused by other subject activities could be reliably distinguished. Subjects showed a characteristic spasm pattern and it was possible to quantify the severity of the spasms and to determine precisely when they occurred. CONCLUSION: This technique for monitoring and quantifying spasms has the potential to be used as a clinical tool to aid in the evaluation and prescription of treatment.

Biomechanical Phenomena↗

Determination of silicon in serum and tissue by electrothermal atomic absorption spectrometry.

OBJECTIVES: To employ an electrothermal atomic absorption spectrometry (ETAAS) method with chemical modifiers for the determination of silicon (Si) in serum and tissues. METHODS: Si was measured in serum of chronic hemodialysis patients, and in fibrous breast capsule tissues following silicone-gel implant removal. Tissue was dried, and digested with concentrated nitric acid prior to analysis. A chemical modifier, which included lanthanum oxide and ammonium phosphate, was used to dilute the serum, and digested tissue samples (1:4) before atomization. Si was determined at 251.6 nm in a graphite fumace using an atomic absorption spectrophotometer. RESULTS: The method was linear (to 1000 micrograms/L), and precise (CV 5.9% at 281 micrograms/L and 8.4% at 73 micrograms/L). Recovery of Si in spiked serum and breast tissue samples was between 97-104%. Reference values for women on a normal diet and no exposure to silicone implants gave serum Si to 30 to 209 micrograms/L (n = 60), and breast tissue levels of 0.25 to 2.4 micrograms/g dry wt (n = 48). Si in breast capsule from women exposed to silicone breast implants varied from 29 to 496 micrograms/g dry wt (n = 10). Serum Si in hemodialysis patients (n = 53) ranged from 900 to 3300 micrograms/L. CONCLUSIONS: We conclude that our chemically modified ETAAS method is suitable for Si determination in normal and elevated human serum and tissue specimens.

Breast↗

Longterm indwelling urethral catheterization for neuropathic bladders--an audit.

An audit was performed on 17 patients with neuropathic bladders managed on longterm indwelling urethral catheters with a duration of at least eight years. The accumulated duration of continuous catheterization of this study group was at least 231 man years. The effects on the upper urinary tracts were studied by annual imaging alternating between limited intravenous urograms and ultrasonography, together with serum creatinine estimations. A grading system for upper tract changes was introduced. About a quarter of the patients on indwelling urethral catheter drainage developed early calyceal dilatation. Three patients were converted to suprapubic catheterization and three had ileoconduit diversion. The reasons were analysed. Although urine cultures were consistently positive with mixed organisms, all instances of clinical urinary tract infections were easily controlled by short courses of antibiotics. In six patients who had cystoscopic examinations, no tumour transformations were noted. Other complications encountered included bladder stones (2), clinically significant urethral fissuring (1) and bleeding per urethra (1). The three considerations for prescribing bladder management are discussed. With good catheter management and regular changes, we conclude that indwelling urethral catheter is a serious option for longterm drainage of neuropathic bladders.

Adult↗

Constipation associated with chronic spinal cord injury: the effect of pelvic parasympathetic stimulation by the Brindley stimulator.

Ten subjects with severe constipation due to complete spinal cord injury (SCI) had prolonged oro-anal transit time (p less than 0.01), diminished faecal water content (p less than 0.05) and a reduced frequency of defaecation (p less than 0.01) compared to 10 non-SCI subjects. Paraplegics with an implanted Brindley S234 anterior sacral nerve root stimulator had a significant increase in frequency of defaecation (p less than 0.01), compared to the SCI group while the faecal water content was less although not significantly so. The Brindley stimulator group also showed a more rapid colonic transit than the SCI group but this did not reach statistical significance. SCI is associated with constipation which therefore appears to be favourably influenced by the Brindley S234 anterior nerve root stimulator. The effects produced are compatible with stimulation of left colonic motility, which facilitates the emptying of the distal colon, but also suggest that part of the response restricts transit in some areas of the colon or rectum. Since the motility changes induced by the Brindley stimulator do not affect the right colon a relatively greater residence time of the faecal bolus in this part of the large bowel would enhance water absorption.

Adult↗

Sperm retrieval by electro-ejaculation. Preliminary experience in patients with secondary anejaculation.

Twelve patients with spinal cord injury and 2 diabetics with secondary anejaculation underwent 26 sessions of electro-ejaculation, using a technique which has previously been popular only in veterinary medicine. Ejaculate was obtained on 21 occasions. Semen quality was adequate for cryostorage on 9 occasions (8 patients); on 8 occasions (5 patients) it was used for immediate artificial insemination of the partner. To date, there has been 1 pregnancy resulting in a live birth.

Adult↗

The effects of neuromuscular stimulation on muscle tone at the knee in paraplegia.

Resting muscle tone of the leg was measured in terms of thigh muscle stiffness and knee resonant frequency in muscles of spinal cord injured subjects who had been involved in an electrical neuromuscular stimulation training programme of the thigh muscles over at least 2 months. The thigh circumference of these patients was 6.6% larger than before training commenced (P less than 0.001) and showed increased muscle stiffness and resonant frequency compared to a similar group of paralysed subjects who had not used any neuromuscular stimulation. Resonant frequency and stiffness after the long-term training were similar to those of non-injured controls and therefore the stimulation programme seemed to reverse the effects of paralysis on muscle tone. Short periods of rest (30 min) caused increased muscle stiffness in non-injured controls and paralysed muscles trained by neuromuscular stimulation. Additional 15 min periods of neuromuscular stimulation further increased muscle stiffness in the trained muscles but also in the muscles of paralysed subjects who had no long-term neuromuscular training. In contrast, 15 min sessions of passive movement of the knee decreased muscle stiffness in long-term trained paralysed muscles and untrained paralysed muscles. Knee resonant frequency was also significantly decreased in the trained paralysed muscles. Results show that muscle tone varies depending on the amount of previous movement or rest and that although neuromuscular stimulation of paralysed muscles increases muscle stiffness and knee resonant frequency, it is in fact restoring such properties of the muscle to a state approaching that of non-injured controls.

Adult↗

Muscle tone around the human knee in paraplegia.

The thigh muscle tone of non-injured subjects and complete injury paraplegics has been investigated using torques, generated by a printed motor, to move the knee. The dynamic measure of resonant frequency (related to stiffness) together with a static measure of stiffness have shown the legs of non-injured subjects to respond non-linearly to decreasing torques. However, the complete paraplegics' legs did not respond non-linearly but showed constant resonant frequency and stiffness over the range of torques. Peak velocity at resonance (inversely related to damping) gradually increased with increasing torques in both groups. In addition, at a chosen baseline torque of 0.7 N m, resonant frequency and muscle stiffness were significantly lower and peak velocity significantly higher in the paraplegics compared to the non-injured subjects. Contrary to expectations the thigh muscles in established, complete paraplegia showed a lack of tonic EMG activity. In addition, whilst phasic stretch responses were occasionally seen there was no tonic activity in relation to continued stretch. Since muscles atrophy after paralysis, the smaller muscle bulk may contribute to the lower muscle tone.

Adult↗

The action of cisapride on the chronic constipation of paraplegia.

Paraplegic patients have intractable constipation associated with prolonged colonic transit time. The agent Cisapride significantly reduced the colonic transit time from 7.7 days to 5.1 days. It also improved the intraluminal tone in the rectum, resulting in a significant reduction in maximal rectal capacity from 305.8 ml to 224.3 ml. There was a reduction in residual urine volume from 51.5 ml to 27.7 ml. The increased number of stools containing transit markers showed that intraluminal mixing was increased by cisapride. Faecal water remained unchanged. A side effect was retention of urine in one subject after sudden withdrawal of the drug but this was avoided by its gradual reduction over 2 days.

Administration, Oral↗

Differential effects of sacral anterior root stimulation on anal sphincter and colorectal motility in spinally injured man.

The motility responses of the sigmoid colon, rectum and external anal sphincter to sequential electrical stimulation of the anterior sacral roots (S2, S3 and S4) were studied in five patients with traumatic spinal cord injury. Identical and reproducible results were obtained. S2 stimulation provoked isolated low-pressure colorectal contractions. S3 stimulation initiated high-pressure colorectal motor activity which appeared peristaltic and was enhanced with repetitive stimuli. This response appeared to be frequency-dependent. S4 stimulation increased colonic and rectal tone. External sphincter activity was stimulated in increasing order from S2 to S4. These observations directly elucidate the central control of colorectal motility and may have implications in the treatment of severe constipation following spinal injury.

Adult↗

Endocrine assessment of the subfertile male.

Sixty-three male (XY) patients attending a subfertility clinic with average sperm density under 40 million/ml were studied by testicular biopsy and multiple basal estimations of plasma LH, FSH, testosterone as well as LHRH (50 micrograms i.v.) stimulation. A further forty patients with similar sperm densities also had testicular biopsy but only single estimations of the three hormones. A single basal FSH was found to be the best discriminator of testicular histologies. Patients with testicular biopsies showing germ cell aplasia in some or all seminiferous tubules (grades 3 and 4) had significantly higher basal FSH than those with hypospermatogenesis, germ cell arrest or normal appearance (grades 1 and 2). Basal FSH also showed a linear trend rising with decreasing sperm density but only rose above the normal range when sperm densities fell below 1 million/ml. When basal FSH, testicular histology and sperm density were considered together in the whole group (n = 100), high levels of FSH accurately indicated the presence of germ cell aplasia in some or all seminiferous tubules in azoo- and oligospermic men with sperm density under 5 million/ml. Normal FSH and azoospermia is diagnostic of obstruction in the excurrent ducts, and further investigation is undertaken if surgical correction of the obstruction is contemplated. Hormone estimations are not helpful in oligospermic patients with average sperm density over 5 million/ml. On the basis of these findings it is suggested that there is little place for the LHRH test in the routine assessment of male subfertility. Testicular biopsy is indicated only in oligospermic patients with average sperm density under 5 million/ml and normal basal FSH.

Adult↗

Assessment of the morbidity and value of prophylactic cephazolin sodium in urinary tract instrumentation in out-patients.

A pilot study showed that following urinary tract endoscopy in out-patients there is a significant incidence of subsequent rigor and general practitioner call-out. A double-blind study was carried out in 690 consecutive patients to assess the effectiveness of prophylactic doses (1 g) of cephazolin, given intravenously or intramuscularly at the time of the procedure, compared with no treatmemnt or placebo. The results, assessed from replies to a questionnaire, showed that whereas cephazolin given intravenously did not affect the incidence of subsequent rigor there was a significant reduction compared with controls when the antibiotic was given in the same dose intramuscularly.

Cefazolin↗

Cytogenetics and infertility in man. II. Testicular histology and meiosis.

Within a group of 207 subfertile men, selected for testicular biopsy, histological investigations were made successfully in 194 chromosomally normal and 7 chromosomally abnormal individuals. Fifty-two per cent of men with a normal karyotype showed normal testicular histology, 31% showed a general depression of spermatogenesis and 8% showed deficiency in the late stages. Ten per cent had only Sertoli cells in the testis. The range of testicular conditions seen in the chromosomally abnormal men was similar to that found in the chromosomally normal. Meiotic studies carried out on 118 chromosomally normal individuals gave a mean chiasma count of 48-9 per cell. There was a positive correlation between high numbers of cells at diakinesis/metaphase I showing X and Y univalents and low numbers of cells reaching metaphase II. Meiosis was studied in 3 translocation heterozygotes, one 47, XYY male, one 47, XY+mar individual and one patient with a ring Y chromosome.

Adult↗

Lymphocytotoxins in vasectomized men.

Serum samples before and after vasectomy were examined for cold and allogeneic lymphocytotoxic antibodies. The techniques used did not demonstrate a significant increase in the incidence of these antibodies following vasectomy.

Antibodies↗