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Biomedical subjects

G Sawle

Publications and source records attributed to G Sawle.

7 recordsLinked to original sources

Short- and long-term survival and function of unilateral intrastriatal dopaminergic grafts in Parkinson's disease.

Six patients with Parkinson's disease were followed for 10 to 72 months after human embryonic mesencephalic tissue from four to seven donors was grafted unilaterally into the putamen (4 patients) or putamen plus caudate (2 patients). After 8 to 12 months, positron emission tomography showed a 68% increase of 6-L-[18F]-fluorodopa uptake in the grafted putamen, no change in the grafted caudate, and minor decreases in nongrafted striatal regions. There was therapeutically valuable improvement in 4 patients, but only modest changes in the other 2, both of whom developed atypical features. Patient 4 was without L-dopa from 32 months and had normal fluorodopa uptake in the grafted putamen at 72 months. Overall, the L-dopa dose was reduced by a mean of 10 and 20%, "off" time was reduced by 34 and 44%, and the "off" phase Unified Parkinson's Disease Rating Scale motor score by 18 and 26%, and the duration of the response to a single L-dopa dose increased by 45 and 58% during the first and second years after surgery, respectively. Rigidity and hypokinesia improved bilaterally, but mainly contralateral to the implant. No consistent changes in dyskinesias were observed. We conclude that transplantation of embryonic mesencephalic tissue leads to highly reproducible survival of dopaminergic neurons, inducing clinically valuable improvements in most recipients.

Adult

Visual vertigo.

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Humans

Evidence for long-term survival and function of dopaminergic grafts in progressive Parkinson's disease.

Two patients with idiopathic Parkinson's disease (Patients 3 and 4 in our series) were followed up to 3 years after grafting of human embryonic dopamine-rich mesencephalic tissue unilaterally into the putamen. During the first postoperative year both patients showed significant amelioration of parkinsonian symptoms and increased 6-L-[18F]-fluorodopa uptake in the grafted putamen, as assessed with positron emission tomography. Three years after grafting the patients still exhibited increased fluorodopa uptake in the grafted putamen and significant clinical improvements, evidenced by a reduction of the severity of symptoms and of the time spent in the "off" phase, and by a prolongation of the effect of a single dose of L-dopa. Between 1 and 3 years after surgery, Patient 3 showed only minor changes of parkinsonian symptoms on the side contralateral to the graft, whereas there was a worsening on the ipsilateral side. Fluorodopa uptake decreased in the nongrafted putamen but was unchanged in the grafted putamen. Patient 4 continued to improve after the first postoperative year and L-dopa was withdrawn after 32 months. The reduction of parkinsonian symptoms on the side contralateral to the graft became more pronounced between 1 and 3 years after surgery. Fluorodopa uptake further increased in the grafted putamen, whereas no change was detected on the non-grafted side. These results indicate that grafts of embryonic dopamine neurons can survive, grow, and exert functional effects up to at least 3 years after surgery in the parkinsonian brain, despite an ongoing disease process leading to degeneration of the intrinsic dopamine system.

Brain Tissue Transplantation

Total lymphoid irradiation in multiple sclerosis.

Following a report of the efficacy of total lymphoid irradiation (TLI) in the treatment of chronic progressive multiple sclerosis a further randomised double-blind placebo-controlled study was undertaken with the intention of entering 56 patients. In the event it was possible to recruit only 27 patients in a 2.5 year period. Three patients received active treatment openly and 24 were randomised to either active (14) or sham (10) treatment. Treatment was 1980 cGy to the lymphoid system and spleen or sham treatment after full simulation. The primary outcome measure was a comparison of the mean rates of change between treatment groups on the expanded Kurtzke disability scale (EDSS) over the two year follow up period. Patients were also assessed on other clinical outcome measures, psychometry, and serial MRI of the brain. Active treatment resulted in a profound and prolonged fall in T lymphocytes especially those with the CD4 marker and a reversal in CD4:CD8 ratio. No significant benefit was demonstrated on the rate of clinical disease progression (EDSS). A small but significant benefit was found on a score of bladder function. No significant benefit was demonstrated on other clinical or psychometric indices or on subjective visual analogue scales. There was a small but significant difference in the rate of accumulation of lesions on brain MRI favouring the treatment group. The treated group had a higher incidence of clinically relevant side effects, notably amenorrhoea and infections: three deaths (one in the TLI group, two in the sham treated group) occurred. A post hoc calculation indicates that the study had a possible 35% risk of a false negative result using the principal outcome measure. The study fails to confirm the previously reported clinical benefit of TLI although there may be a minor benefit on disease progression as indicated by MRI lesion counts. It is concluded that TLI cannot be recommended for the routine treatment of chronic progressive multiple sclerosis but the beneficial effect on MRI lesions, though modest, suggests that further research into immune modulation of this condition may be worthwhile.

Adult

Transplantation of fetal dopamine neurons in Parkinson's disease: one-year clinical and neurophysiological observations in two patients with putaminal implants.

Ventral mesencephalic tissue from aborted human fetuses (age, 6-7 weeks' postconception) was implanted unilaterally into the putamen using stereotaxic surgery in 2 immunosuppressed patients (Patients 3 and 4 in our series) with advanced idiopathic Parkinson's disease. Tissue from 4 fetuses was grafted to each patient. Compared with our previous 2 patients, the following changes in the grafting procedure were introduced: the implantation instrument was thinner, more tissue was placed in the operated structure, and the time between abortion and grafting was shorter. There were no postoperative complications. Both patients showed a gradual and significant amelioration of parkinsonian symptoms (most marked in Patient 3) starting at 6 and 12 weeks after grafting, respectively, reaching maximum stability at approximately 4 to 5 months; patients remained relatively stable thereafter during the 1-year follow-up period. Clinical improvement was observed as a reduction of the time spent in the "off" phase and the number of daily "off" periods; a lessening of bradykinesia and rigidity during the "off" phase, mainly but not solely on the side contralateral to the graft; and a prolongation and change in the pattern of the effect of a single dose of L-dopa. Neurophysiological measurements revealed a more rapid performance of simple and complex arm and hand movements bilaterally, but primarily contralateral to the graft. The results indicate that patients with Parkinson's disease can show significant and sustained improvement of motor function after intrastriatal implantation of fetal dopamine-rich mesencephalic tissue. The accompanying paper by Sawle and colleagues describes the results of repeated positron emission tomography scans in these patients.

Combined Modality Therapy

Grafts of fetal dopamine neurons survive and improve motor function in Parkinson's disease.

Neural transplantation can restore striatal dopaminergic neurotransmission in animal models of Parkinson's disease. It has now been shown that mesencephalic dopamine neurons, obtained from human fetuses of 8 to 9 weeks gestational age, can survive in the human brain and produce marked and sustained symptomatic relief in a patient severely affected with idiopathic Parkinson's disease. The grafts, which were implanted unilaterally into the putamen by stereotactic surgery, restored dopamine synthesis and storage in the grafted area, as assessed by positron emission tomography with 6-L-[18F]fluorodopa. This neurochemical change was accompanied by a therapeutically significant reduction in the patient's severe rigidity and bradykinesia and a marked diminuation of the fluctuations in the patient's condition during optimum medication (the "on-off" phenomenon). The clinical improvement was most marked on the side contralateral to the transplant.

Brain