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Biomedical subjects

D M Park

Publications and source records attributed to D M Park.

At least 19 recordsLinked to original sources
PubMed2000

Direct muscle neurotization in rat soleus muscle.

An experimental study was conducted using rat soleus muscles to characterize reinnervation of the denervated muscles by direct muscle neurotization. Also studied was whether there is any difference in the regeneration process between original (tibial) and foreign (peroneal) nerve neurotization. For functional evaluation, an electrophysiologic study was carried out by analyzing pattern, latency, amplitude, and duration of compound motor action potential. In a histochemical study, both hematoxylin-eosin stain and nicotineamide adenin dehydrogenase stain were used to identify the morphology and the change in the type of muscle fiber. Combined silver-acetylcholinesterase stain was utilized to identify reinnervated motor endplates and axonal sprouting. Evidence of regeneration of the denervated muscle by direct muscle neurotization could be confirmed. Regenerating muscles showed type grouping of muscle fibers. The newly-formed ectopic motor endplate was connected with axonal sprouting. The giant motor endplate composed of mature axon sprouting and several new ectopic motor endplates appeared in the neurotization group. There was no specific difference in the regeneration process between original and foreign nerve neurotization.

Animals↗
PubMed2000

Direct muscle neurotization in rat soleus muscle.

The authors carried out an experimental study using rat soleus muscles to evaluate reinnervation of the denervated muscles by direct muscle neurotization. They also attempted to determine whether there is any difference in the regeneration process between original (tibial) and foreign (peroneal) nerve neurotization. For functional evaluation, they did an electrophysiologic study by analyzing pattern, latency, amplitude, and duration of compound motor action potential. For histochemical studies, both hematoxyline-eosin stain and nicotineamide adenin dehydrogenase stainings were used to identify the morphology and the change of the type of muscle fiber. Combined silver-acetylcholinesterase stain was performed to identify reinnervated motor endplate and axonal sprouting. They confirmed evidence of regeneration of the denervated muscle by direct muscle neurotization. Regenerating muscles showed type groupings of muscle fibers. The newly-formed ectopic motor endplate was connected with axonal sprouting. The giant motor endplate composed of mature axon sprouting and several new ectopic motor endplates, appeared in the neurotization group. There was no significant difference in the regeneration process between original and foreign nerve neurotization.

Animals↗
PubMed1999

Lamotrigine monotherapy in newly diagnosed untreated epilepsy: a double-blind comparison with phenytoin.

PURPOSE: Lamotrigine is an effective add-on therapy against a range of epileptic seizure types. Comparative studies with carbamazepine (CBZ) as monotherapy in newly diagnosed epilepsy suggest similar efficacy. In this study, lamotrigine (LTG) and phenytoin (PHT) are compared. METHODS: In a double-blind parallel-groups study, 181 patients with newly diagnosed untreated partial seizures or secondarily or primary generalised tonic-clonic seizures were randomised to two treatment groups. One group (n = 86) received LTG titrated over 6 weeks from a starting dose of 100 mg/day. The other (n = 95) received PHT titrated from 200 mg/day. Treatment continued for < or =48 weeks. RESULTS: The percentages of patients remaining on each treatment and seizure free during the last 24 and 40 weeks of the study, and times to first seizure after the first 6 weeks of treatment (dose-titration period), did not differ significantly between the treatment groups. These were measures of efficacy. Time to discontinuation, a composite index of efficacy and safety, likewise did not distinguish between treatments. Adverse events led to discontinuation of 13 (15%) patients from LTG and 18 (19%) from PHT. The adverse-event profile for LTG was dominated by skin rash [discontinuation of 10 (11.6%) patients compared with five (5.3%) from PHT] rather than central nervous system side effects: asthenia, somnolence, and ataxia were each significantly more frequent in the PHT group. The high rate of rash with LTG was probably due to the high starting dose and may be avoidable. A quality-of-life instrument, the SEALS inventory, favoured LTG. Patients taking PHT showed the biochemical changes expected of an enzyme-inducing drug, whereas those taking LTG did not. CONCLUSIONS: LTG and PHT monotherapy were similarly effective against these seizure types in patients with newly diagnosed epilepsy. LTG was better tolerated, more frequently causing rash, but with a lower incidence of central nervous system side effects.

Adolescent↗
PubMed1996

Botulinum toxin--a possible new treatment for axillary hyperhidrosis.

The inhibitory action of botulinum toxin is not limited to the neuromuscular junction. The toxin also blocks the autonomic cholinergic fibres, including the sympathetic fibres to sweat glands. We have previously demonstrated that the toxin produces localized anhidrosis. To determine the dosage, pattern and duration of the anhidrotic effect of botulinum toxin and to test the efficacy of axillary injections, we further studied seven healthy volunteers. Two individuals had subcutaneous injections of botulinum toxin (20 mouse units, Dysport-Porton Products) in the dorsum of the hand. Five healthy volunteers had 15-50U of botulinum toxin A (Botox) injected in one axilla. A circular area of complete anhidrosis on the dorsum of the hand was evident on day 2 and persisted for 11 months. By day 3, two of the axillae (injected with 50 U each) were totally dry and in one (injected with 30 U) the sweating was substantially reduced. The effect persisted for 6-8 months before wearing off. No effect was appreciated in two axillae (injected with 15 and 20 U). No significant side-effects were encountered. Subcutaneous injections of botulinum toxin causes chemodenervation of the sweat glands. In normal individuals axillary sweating can be abolished by 50 U of botulinum toxin A (Botox). The results offer a possible novel treatment for severe cases of axillary hyperhidrosis.

Adult↗
PubMed1991

Scales for rating motor impairment in Parkinson's disease: studies of reliability and convergent validity.

Study 1 examined the reliability of the ratings assigned to the performance of five sign-and-symptom items drawn from tests of motor impairment in Parkinson's disease. Patients with Parkinson's disease of varying severity performed gait, rising from chair, and hand function items. Video recordings of these performances were rated by a large sample of experienced and inexperienced neurologists and by psychology undergraduates, using a four point scale. Inter-rater reliability was moderately high, being higher for gait than hand function items. Clinical experience proved to have no systematic effect on ratings or their reliability. The idiosyncrasy of particular performances was a major source of unreliable ratings. Study 2 examined the intercorrelation of several standard rating scales, comprised of sign-and-symptom items as well as activities of daily living. The correlation between scales was high, ranging from 0.70 to 0.83, despite considerable differences in item composition. Inter-item correlations showed that the internal cohesion of the tests was high, especially for the self-care scale. Regression analysis showed that the relationship between the scales could be efficiently captured by a small selection of test items, allowing the construction of a much briefer test.

Activities of Daily Living↗
PubMed1989

Effect of treatment with botulinum toxin on spasticity.

Botulinum toxin, a product of Clostridium botulinum, produces presynaptic neuromuscular block by preventing release of acetylcholine from nerve endings. The toxin was injected directly into the skeletal muscles of six patients with severe spasticity due to stroke-related hemiplegia. It produced both subjective and objective improvement. The toxin injections were well tolerated and no significant side effect was reported.

Adult↗
PubMed1989

Botulinum toxin in treating spasticity.

The value of locally injected botulinum toxin is emphasised. The toxin was injected directly into the skeletal muscles of eight patients with severe spasticity due to stroke-related hemiplegia. It produced both subjective and objective improvement. The toxin injections were well tolerated and no significant side effects were noted.

Adult↗
PubMed1986

EEG characteristics of epileptic pattern sensitivity and their relation to the nature of pattern stimulation and the effects of sodium valproate.

Seven patients with pattern-sensitive epilepsy were examined repeatedly over a period of 4-12 months during which the dose of sodium valproate was adjusted. Patterns were presented in series in which the size of successive patterns was progressively increased until paroxysmal activity appeared, or until the largest pattern (radius 24 degrees visual angle) had been presented. As valproate dose increased, paroxysmal activity was less likely to occur. When it did occur it was less likely to include a spike; it had a lower voltage, involved fewer electrodes, and lasted a shorter time. The size of the pattern just sufficient to induce paroxysmal activity showed relatively little change with valproate dose. The degree to which the various electrodes were involved in the discharges showed considerable stability. The paroxysmal response to patterns presented in one visual half-field was almost invariably maximal over the contralateral posterior quadrant, usually at the posterior temporal electrode.

Adolescent↗
PubMed1982

A comparison of phenytoin and pheneturide in patients with epilepsy: a double-blind cross-over trial.

A double-blind cross-over trial between pheneturide and phenytoin in ninety-four outpatients with epilepsy is described. There was no significant difference between the frequency of seizures in the two groups. The difficulties in comparing two anticonvulsants of similar efficacy are discussed particularly in relation to ethical problems, the selection of patients and trial design.

Adolescent↗
PubMed1981

Nomifensine: effect in Parkinsonian patients not receiving levodopa.

A clinical trial using the anti-depressant nomifensine in Parkinsonism is reported. Eighteen subjects not receiving levodopa participated. The drug had a small, but significant anti-Parkinsonian effect. No troublesome side effects were encountered. In the treatment of Parkinsonism, nomifensine may be considered as an alternative to amantadine or anticholinergics, especially where depression is an added feature.

Aged↗
PubMed1979

Exercise and hormonal secretion.

The effect of graded exercise on the secretion of cortisol, testosterone, prolactin, growth hormone, thyroid stimulating hormone (TSH), luteinizing hormone and follicle stimulating hormone (FSH) is reported. While cortisol, prolactin, growth hormone and testosterone rise during the period of exercise, a rise in luteinizing hormone becomes evident only after rest. Levels of FSH and TSH remained unchanged.

Adolescent↗
PubMed1977

Nomifensine in parkinsonism.

1. The effect of nomifensine was compared with that of placebo in a double-blind crossover study in patients with parkinsonism. 2. Of the 29 patients who entered the study, three were previously untreated and 26 continued their L-DOPA or other antiparkinsonian therapy, or both, during the trial. 3. Clinical assessments were made at fortnightly intervals throughout the study. 4. The most noticeable improvement during active treatment--namely, tremor, facial expression and finger flexion were moderate in extent. 5. When placebo was substituted for active drug a significant deterioration of physical signs and functional disability occurred (P less than 0.001). 6. Elderly patients fared less well than younger patients, and the most common adverse effect was involuntary movements.

Aged↗
PubMed1976

Differences in the metabolic and hormonal response to exercise between racing cyclists and untrained individuals.

1. Six well-trained cyclists and six untrained subjects were studied during and immediately after four successive 7 min periods of exercise at 30, 45, 60 and 75% of their maximal work capacity. 2. Venous blood samples were taken at rest, at the end of each exercise period and 5 min following the end of exercise, for estimation of metabolites in blood and plasma insulin, growth hormone, cortisol and catecholamines. 3. The results showed significant differences in the mobilization and utilization of muscle fuels between the athletically fit cyclists and the untrained group. In the cyclists, glucose, glycerol and free fatty acid concentrations were higher, but lactate, pyruvate and alanine were lower than in the untrained subjects during exercise. 4. Plasma catecholamines rose in both groups during exercise but the rise was significantly less in the racing cyclists. Plasma insulin was depressed to a greater extent in the untrained subjects during exercise and plasma glucagon rose to a greater extent during strenuous exercise and remained elevated after the end of exercise in the untrained group. Plasma human growth hormone rose to a greater extent during exercise and remained elevated after the end of exercise in the untrained group. Plasma cortisol fell at low and moderate exercise rates in both groups, but to a smaller extent in the cyclists. Cortisol values rose at higher workloads and were significantly higher in the cyclists at the end of exercise. 5. It is concluded that there are significant differences in the metabolic and hormonal responses to exercise between athletically trained and untrained individuals, even when the physically fit subjects work at the same percentage of their maximal capacity as the unfit subjects.

Adult↗
PubMed1976

Nomifensine in parkinsonism.

Nomifensine, a tetrahydroisoquinolone antidepressant which facilitates dopaminergic and noradrenergic transmission, was studied in 28 Parkinsonism patients most of whom were also receiving conventional medications. Double-blind evaluations revealed a moderate therapeutic action at a mean dose level of 150 mg daily. Adverse reactions were encountered, similar to those identical by levodopa.

Aged↗
PubMed1976

Uptake and release of hormones and metabolites by tissues of exercising leg in man.

To examine release of insulin from tissues of the exercising llin, growth hormone, cortisol, and circulating metabolites were studied in five men before, during, and after exercise on a bicycle ergometer at 60% of their maximum work capacity. At rest, insulin, growth hormone, and cortisol were taken up by leg tissues. During exercise arterial plasma insulin concentration fell, but cortisol and growth hormone levels rose; there was net release of insulin into venous blood but little change in uptake of cortisol and growth hormone. Insulin release persisted after exercise for 15-30 min. During exercise arterial concentrations and uptake of glucose and free fatty acids (FFA) increased. Examination of the changes in hormones and metabolites failed to identify any single hormonal or metabolic factor causing the observed reversal of insulin uptake with exercise.

Adult↗