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Biomedical subjects

C M Tanner

Publications and source records attributed to C M Tanner.

At least 73 records · Page 4Linked to original sources
PubMed1989

Multicenter study of autologous adrenal medullary transplantation to the corpus striatum in patients with advanced Parkinson's disease.

In 19 patients with severe Parkinson's disease, we replicated the surgical procedures developed by Madrazo et al. for transplantation of the adrenal medulla to the striatum, and followed them for six months after operation. We monitored their motor function with the use of standardized scales and determined the amount and quality of "on" and "off" time (the hours of the waking day when the antiparkinsonian medications were effective and ineffective, respectively). We found significant improvement in focal areas of motor function. The mean percentage of on time during the day increased from 47.6 percent to 75.0 percent (P = 0.012); the mean percentage of on time without chorea increased from 26.6 percent to 59.2 percent (P = 0.006); the mean severity of off time decreased as assessed by both the Activities of Daily Living subscale of the Unified Parkinson's Disease Scale (P = 0.002) and the Schwab and England scale (P = 0.037). In contrast to the finding of Madrazo et al., however, the dosages of antiparkinsonian medications could not be decreased and postoperative morbidity was substantial. Despite cautious optimism, we conclude that the widespread use of this procedure outside of research centers is premature, since the improvement we found was slighter than in the previous cases.

Activities of Daily Living↗
PubMed1989

The role of environmental toxins in the etiology of Parkinson's disease.

The production by the pyridine MPTP of a parkinsonian syndrome strikingly similar to the 'idiopathic' disorder, and the paucity of evidence supporting a hereditary or infectious etiology for Parkinson's disease (PD), have stimulated a search for environmental chemicals resembling MPTP that might cause PD. In support of this, descriptive epidemiological studies have found higher prevalences of PD in highly industrialized countries. In North America and Europe, early onset PD appears to be associated with rural residence. Factors associated with this include vegetable farming, well water drinking, wood pulp, paper and steel industries. In China, living in industrialized urban areas increases the risk of developing PD. Preliminary epidemiological evidence supports the hypothesis that environmental chemicals may be related to the development of PD, but specific chemicals and their specific mechanism(s) have not been identified.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1989

Environmental and behavioural factors affecting the prevalence of foot lameness in New Zealand dairy herds - a case-control study.

A case-control study of environmental and behavioural factors influencing foot lameness was undertaken on 62 dairy herds comprising an average of 185 milking cows in Taranaki, New Zealand. Thirty two case herds were identified as having had at least 10 per cent of the cows lame during the milking season in which the herd was studied, and thirty control herds were selected on the basis that no more than 3 per cent of cows in these herds had been lame per year for at least two years immediately prior to investigation. Each herd was visited at both a morning and an afternoon milking, and 58 risk factors were measured between the time the farmer began to assemble the cows for milking and the completion of milking. Comparison of single variables between case and control herds identified 24 which showed differences (p<0.10). These variables were then subjected to stepwise multivariate logistic regression, and statistically significant variables in this analysis were used to create a tentative path diagram of possible causal web relationships between the various risk factors and the outcome variable, the lameness prevalence level. Information from a review of the published literature was used to include further variables to the 24 into the initial (or null hypothesis) path model. Logistic path analysis was then used to eliminate non-significant paths from the diagram, leaving 19 arrows joining 13 variables in the final path diagram, compared with 33 joining 20 variables in the initial version. The most influential variables in explaining variation between case and control herds were the average level of maintenance of the track and the degree of patience shown by the farmer in bringing the cows in for milking. Overall, factors associated with the movement of animals to the milking shed explained 40 per cent of the variation (deviance) with regard to the lameness prevalence level. Risk factors associated with characteristics of the milking process explain 24 per cent, and risk factors associated with characteristics of the cows in the herd explain 9.5 per cent. Recommendations are made on management changes which deserve further investigation as ways of reducing lameness problems in dairy herds.

Journal Article↗
PubMed1989

Hypersexuality with antiparkinsonian therapy.

Thirteen parkinsonian patients drawn from two large parkinsonism clinics experienced hypersexuality as a consequence of anti-parkinsonian therapy. The cases include only those whose sexual behavior on treatment became a concern to the patient's family or a social agency. The majority of patients were men and had a relatively early onset of parkinsonian symptomatology. There was no relation between functional improvement and increased sexuality. Most patients showed some element of dose dependency between antiparkinsonian drugs and the hypersexual behavior. Prior sexual profile included from no sexual outlet to hypersexuality. Neither the prior history of psychiatric illness nor brain damage predisposed to such response on treatment, and in most patients, it was not a part of hypomania or a more diffuse psychiatric disturbance. We propose that hypersexuality on antiparkinsonian drugs is consequent to inhibition of prolactin secretion.

Adult↗
PubMed1989

Environmental factors and Parkinson's disease: a case-control study in China.

We studied the role of environment in the development of Parkinson's disease (PD) in China, where industrialization is relatively recent and the population geographically stable. Using a case-control method, we investigated the relationship between PD and exposure to the following factors before disease onset: place of residence, source of drinking water, environmental and occupational exposure to various agricultural and industrial processes. Occupational or residential exposure to industrial chemicals, printing plants, or quarries was associated with an increased risk of developing PD. In contrast, living in villages and exposure to the common accompaniments of village life, wheat growing and pig raising, were associated with a decreased risk for PD. PD cases and controls did not differ with respect to other factors investigated. These findings are consistent with the hypothesis that environmental exposure to certain industrial chemicals may be related to the development of PD.

Adult↗
PubMed1989

Agonist substitution in advanced Parkinson's disease.

We studied whether Parkinson's disease patients who had lost efficacy from pergolide (PERG) could benefit if transferred to bromocriptine (BCT) therapy. Using paired t-tests, we compared motor scores at baseline (when patients were still on PERG) and after 6 months of BCT therapy in 11 patients. No significant improvement occurred in any measure on BCT therapy (mean dose 33.6 mg/day), although patients remained stable. In 6 patients on whom "on/off" data were obtained, decreased "off" time and increased "on" time without chorea occurred, but these changes were not statistically significant. The side effect profile was similar with the 2 drugs.

Aged↗
PubMed1989

Development and progression of motor fluctuations and side effects in Parkinson's disease: comparison of Sinemet CR versus carbidopa/levodopa.

We compared the chronic (2-year) effect of substitution with Sinemet CR with the effect of continued administration of standard Sinemet on motor fluctuations and drug-induced side effects in Parkinson's disease (PD). Twelve patients in each treatment group were pair-matched for age, PD duration, duration of levodopa therapy, dosage of Sinemet, PD disability, and side-effect prevalence at study entry. After 2 years, both groups were more disabled from their PD than at baseline; the disability scores were equivalent for the 2 treatments. The Sinemet CR group had fewer fluctuations and fewer side effects. Compared with the standard Sinemet group, Sinemet CR patients had more "on" time (mean 83% versus 62%, p less than 0.001), and had a lower prevalence of disabling chorea (p less than 0.007), dystonia (p less than 0.003) and sleep disruption (p less than 0.002). Prevalence of hallucinations was equivalent for the 2 groups. These results suggest that Sinemet CR is beneficial in ameliorating and preventing the high frequency of some side effects of standard Sinemet treatment.

Antiparkinson Agents↗
PubMed1989

Conventional cemented total hip arthroplasty. Assessment of clinical factors associated with revision for mechanical failure.

This study investigates risk factors associated with mechanical loosening of cemented total hip arthroplasties. Mechanical failure was evaluated using survivorship analysis on all arthroplasties performed at the authors' institution by the Orthopedic Service from March 1971 until September 1983. Failure was defined as the necessity for replacement of one or more components for any reason other than infection. The failure rate was approximately 1.7% per year and, at 12 years, 20% of the hips had failed. Variables evaluated as potential risk factors for arthroplasty revision included weight, gender, age, surgeon, preoperative functional status, prosthetic type, and diagnosis. A Cox proportional hazard analysis indicated that weight (p less than 0.015) and age (p = 0.087) are important determinants of hip failure. The use of regression trees identified subsets of patients at differing risks for failure. Patients who weighed less than 75.22 kg had the best outcome with a 90% survival to 12 years. Patients weighing more than 75.22 kg are at varying risk depending on their age. These data define a subset of special-risk patients not previously described. Patients weighing more than 75.22 kg who were older than 75.4 years had a revision rate of 73% by eight years.

Activities of Daily Living↗
PubMed1988

An antibody in the CSF of Parkinson's disease patients disappears following adrenal medulla transplantation.

CSF from Parkinson's disease (PD) patients undergoing autologous transplantation of adrenal medulla tissue into their lateral ventricle was examined for the presence of IgG. CSF from 6 of 7 patients incubated with rat brain tissue reacted immunocytochemically to neuronal cell bodies in the substantia nigra and ventral tegmental region. This reactivity gradually disappeared in the months following transplantation. Five of 6 CSF samples from non-transplanted PD patients also produced this immunocytochemical reactivity whereas 26 non-PD samples were immunonegative. Possible implications to the transplant procedure are discussed.

Adrenal Medulla↗
PubMed1988

Concurrent treatment with benztropine and haloperidol attenuates development of behavioral hypersensitivity but not dopamine receptor proliferation.

Groups of male rats (n = 16 each) were treated with normal saline, haloperidol (0.75 mg/kg), benztropine (1.8 mg/kg) or haloperidol and benztropine once a day for 24 days. Following a 96 hour drug free interval, subsets of these animals were assessed for apomorphine-induced (0.75 mg/kg) stereotypic behavior, sacrificed and analyzed for striatal dopamine biochemistry or sacrificed and analyzed for spiroperidol binding sites. Benztropine cotreatment attenuated the development of behavioral hypersensitivity to haloperidol but did not alter either the dopamine receptor proliferation or the striatal dopamine biochemical changes induced by haloperidol. These results suggest that behavioral hypersensitivity is not an automatic manifestation of dopamine receptor proliferation but must depend, in part, on other factors.

Animals↗
PubMed1988

Risk factors for progression in Parkinson's disease.

Using case-control methodology, we assessed prevalence and duration of exposure to putative risk factors for rapid progression of Parkinson's disease (PD) in patients not taking levodopa or direct dopamine agonists. We identified 31 patients termed "rapidly progressive" who were stage I or II (Hoehn and Yahr) on their first visit to our center and who progressed to stage III during the study period; we pair-matched this group with 31 "slowly progressive" patients who had the same symptom duration and the same Hoehn and Yahr stage at study entry, but whose parkinsonism did not progress to stage III during the study. Only age of PD onset was associated with different rates of PD progression; older patients at PD onset progressed more rapidly than younger patients.

Age Factors↗
PubMed1988

Controlled-release carbidopa/levodopa (CR4-Sinemet) in Parkinson's disease patients with and without motor fluctuations.

Sixteen patients with advanced Parkinson's disease (PD) and motor fluctuations were evaluated throughout 12 months of open label therapy on CR4-Sinemet. Reduced dosage frequency and significant motor improvement with reduced fluctuation occurred and were maintained with CR4-Sinemet compared with baseline on Sinemet. In a double-blind protocol using CR4-Sinemet in 20 stable PD patients, CR4-Sinemet was given twice daily and compared with Sinemet given four times daily. Patients remained stable without improvement or deterioration when the long-acting drug was substituted at 50% frequency. Plasma levodopa levels with CR4-Sinemet were smoother than with Sinemet. Although some patients receiving CR4-Sinemet found they functioned more slowly in the morning, the easier dosing schedule and improved amount of "on" time in fluctuators suggest that this formulation may become increasingly useful in managing PD.

Adult↗
PubMed1988

The adrenal medullary transplant operation for Parkinson's disease: clinical observations in five patients.

The recent report by Madrazo and coworkers on the successful treatment of Parkinson's disease using adrenal medullary tissue transplanted to the caudate nucleus has aroused international interest in the procedure. The present article reports our initial experiences with the operation in five patients and discusses the postoperative effects of the procedure, the protocol used to monitor motor performance, and the need for cooperation with the two registries that have been created to follow morbidity, mortality, and efficacy. We intend to alert the neurosurgeon to important side effects, but not to assess the long term efficacy of the procedure. Postoperatively, a number of transient effects were seen in our patients, the most striking being somnolence, delusions, and lack of significant pain in spite of a large abdominal incision. The only complications have been respiratory. After the early postoperative period, gradual improvement of on-off times and Schwab-England disability scores was seen over 20 weeks. Long term cooperative studies are needed to demonstrate the efficacy of this procedure. neurosurgeons doing transplant operations are urged to join the registries so that uniform information can be collected.

Adrenal Medulla↗
PubMed1988

Relationship of aluminum to neurocognitive dysfunction in chronic dialysis patients.

Aluminum has been proposed as the causative agent in dialysis encephalopathy syndrome. We prospectively assessed whether other, less severe, neuropsychologic abnormalities were also associated with aluminum. A total of 16 patients receiving chronic dialytic therapy were studied. The deferoxamine infusion test (DIT) was used to assess total body aluminum burden. Neurologic function was evaluated by quantitative measures of asterixis, myoclonus, motor strength, and sensation. Cognitive function was assessed by measures of dementia, memory, language, and depression. There were four patients with a positive DIT (greater than 125 micrograms/L increment in serum aluminum) that was associated with an increase in the number of neurologic abnormalities observed, as well as an increase in severity of myoclonus, asterixis, and lower extremity weakness. Patients with a positive DIT also showed significant impairment in memory; however, no differences were noted on tests of dementia, depression, or language. There was no significant correlation between sex, age, presence of diabetes, mode of dialysis, years of chronic renal failure, years of dialysis or years of aluminum ingestion and any neurologic or neurobehavioral measurement, serum aluminum level, or DIT. These changes may represent early aluminum-associated neurologic dysfunction.

Adult↗