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Biomedical subjects

Sten-Magnus Aquilonius

Publications and source records attributed to Sten-Magnus Aquilonius.

10 recordsLinked to original sources

Focused proteomics in post-mortem human spinal cord.

With a highly sensitive electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS) system, proteins were identified in minimal amounts of spinal cord from patients with the neurodegenerative disease amyotrophic lateral sclerosis (ALS) and compared to proteins in spinal cord from control subjects. The results show 18 versus 16 significantly identified (p < 0.05) proteins, respectively, all known to be found in the central nervous system. The most abundant protein in both groups was the glial fibrillary acidic protein, GFAP. Other proteins were, for example, hemoglobin alpha- and beta chain, myelin basic protein, thioredoxin, alpha enolase, and choline acetyltransferase. This study also includes the technique of laser microdissection in combination with pressure catapulting (LMPC) for the dissection of samples and specific neurons. Furthermore, complementary experiments with nanoLC-matrix assisted laser desorption ionization time-of-flight tandem mass spectrometry (MALDI-TOF-TOF MS) confirmed the results of the ESI-FTICR MS screening and provided additional results of further identified proteins.

Amyotrophic Lateral Sclerosis↗

[A national curriculum in neurology for medical education].

The knowledge within medicine is growing rapidly. It has become more and more difficult to decide what knowledge that has to be taught to medical students during their University Medical Degree (MD) education and what has to be omitted from their study plans. As help for teachers and students, a core curriculum of the education defines what is of importance for all students. However, there is a risk of "curriculum overload" with too much information being put into a short time interval. To avoid this and to define what is really the "core" of a course, a national consensus decision may be useful. As an example of this approach, we here report a new joint Swedish core curriculum in neurology for medical students. Teachers responsible for neurological education at all six universities giving University MD education in Sweden have in January 2003 agreed upon the core curriculum that we present. It is our hope that this method can be useful also for other clinical specialities.

Clinical Competence↗

Wireless real-time electronic data capture for self-assessment of motor function and quality of life in Parkinson's disease.

Frequent assessment of the symptoms in Parkinson's disease (PD) is important in both clinical and experimental settings, especially when motor fluctuations are present. Patient diaries are increasingly used in studies, allowing patients to stay in their home environments. However, traditional paper diaries may not reflect reality because of a lack in compliance or retrospective data entries. This study presents a comparison between paper diaries and a new method, real-time data capture with a hand-held computer (electronic diary). Twenty patients with PD diagnosed at least 5 years previously were randomly assigned to use either a paper diary or an electronic diary on 8 days during 1 month. Questions were answered every 2 hours over a 12-hour period on each day. Median compliance was 88% with the electronic diary and 98% with the paper diary, although strict compliance to the scheduled times by patients using the paper diary was 78%. Neither age nor earlier experience with computers affected the patient's ability to use the electronic diary. Electronic diaries can be used for self-assessment of PD symptoms. The real-time feature provides fast access to clean data with knowledge of true compliance.

Adult↗

Cerebrospinal fluid protein patterns in neurodegenerative disease revealed by liquid chromatography-Fourier transform ion cyclotron resonance mass spectrometry.

This study demonstrates the power of a novel proteomic approach developed for the detection and identification of biological markers in body fluids. The goal was to observe alterations in the protein patterns of cerebrospinal fluid (CSF) related to amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder with unknown etiology. In the experiments, tryptic digests of CSF from patients and healthy controls were analyzed by on-line capillary liquid chromatography-Fourier transform ion cyclotron resonance mass spectrometry. (FT-ICR MS) Typically, around 4000 peptides were detected in one such experiment, and a pattern recognition program was constructed for the data analysis to distinguish mass chromatograms from patients and controls. This strategy was evaluated comparing the peptide patterns of CSF spiked in vitro with a biomarker, with control CSF. The patterns were clearly separated and the tryptic peptides of the biomarker were successfully selected as characteristic peaks. Hence, the method was applied to compare mass chromatograms of CSF from 12 ALS-patients and 10 matched healthy controls. While no biomarker alone could be identified from the characteristic peaks, we were able to assign 4 out of 5 unknown samples correctly (i.e., 80% correctly diagnosed, 20% false-negative), and it would be 100% if we reject a possible outlier believed to be caused by an occlusion in the spinal CSF compartment. These findings are very promising, although the clinical relevance is not fully established due to the low number of unknown samples analyzed. In addition to the diagnostic potential, these results may be important steps towards understanding the neurodegenerative process.

Adult↗

The increased utilisation of dopamine agonists and the introduction of COMT inhibitors have not reduced levodopa consumption--a nation-wide perspective in Sweden.

OBJECTIVE: To study the impact of the new pharmacological treatment strategies in Parkinson's disease by analysis of the sales of dopaminergic drugs in Sweden 1990-2001. METHODS: Invoice statistics and statistics on prescription sales of dopaminergic drugs 1990-2001 were obtained from the 906 public pharmacies and the 89 hospital pharmacies in Sweden. The Swedish Diagnosis and therapy survey was used to study the diagnosis the drugs were prescribed for. RESULTS: During the period the sales expressed in DDD/1000 inhabitants and day increased from 1.75 to 1.86 (6%) for levodopa and from 0.04 to 0.27 (575%) for dopamine agonists. The increase in sales of dopamine agonists occurred after 1997 and consisted entirely of the sales of the new agonists, cabergoline, pramipexole and ropinirole. In Swedish crowns the total sales of dopaminergic drugs increased with 126% during the period. The cost for the dopamine agonists was 8% of the total cost for dopaminergic drugs in 1990 and 23% in 2001. The prescription sales figures of levodopa and dopamine agonists for the different Swedish counties in 2001 varied between 1.52 and 2.44 and 0.13 and 0.74 DDD/1000 inhabitants and day, respectively. There was no correlation, whether positive or negative, between the sales of dopamine agonists, levodopa and COMT inhibitors or between the sales and the densities of neurologists. CONCLUSION: The consumption of levodopa in Sweden continues to increase in spite of a dramatic increase in the utilisation of dopamine agonists and the introduction of COMT-inhibitors.

Catechol O-Methyltransferase Inhibitors↗

Levodopa pharmacokinetics and motor performance during activities of daily living in patients with Parkinson's disease on individual drug combinations.

Pharmacokinetics and pharmacodynamics of levodopa were evaluated at a high-resolution level in a heterogeneous group of 10 patients with idiopathic Parkinson's disease during their normal daily activity. A physician and a nurse spent 10 hours with each patient from the first morning dose of levodopa during daily activities at home and at work. Plasma samples were obtained every 20 minutes for analysis of levodopa and 3-O-methyldopa by high-performance liquid chromatography. To assess clinical response, mobility was rated on every test occasion by patients and by investigators. Food and fluid intake and physical activity were also monitored. There was a large intra- and interindividual variability in the pharmacokinetics of levodopa regardless of the different drug combinations used. Mean plasma levodopa concentration ranged between 0.45 to 7.07 microg/mL and peak concentrations between 0.95 to 13.75 microg/mL. In 44 of 58 dosing events, an oral dose of levodopa was related to a peak in plasma concentration. Assessment of the clinical effects was more sensitive when given by patients than when given by the investigators. The fluctuations of the levodopa concentration in plasma had a clear effect on the clinical parameters assessed, even during early disease stages. Variation in levodopa concentration is the determining factor for motor fluctuations also in patients on clinically optimized combinations with dopamine agonists and enzyme inhibitors.

Activities of Daily Living↗

Optimizing levodopa pharmacokinetics: intestinal infusion versus oral sustained-release tablets.

Continuous duodenal infusion of carbidopa/levodopa has been shown to control motor fluctuations in advanced Parkinson's disease (PD). The authors compared the pharmacokinetics of levodopa and 3-O-methyldopa in patients with advanced PD after administration of an oral sustained-release levodopa preparation and after continuous intestinal levodopa infusion with a new formulation as a gel suspension. A randomized crossover trial was carried out in 12 patients. Carbidopa/levodopa was administered as an oral sustained-release tablet and by nasoduodenal continuous infusion for 3-week periods for each treatment. Plasma levodopa concentrations and motor performance were evaluated every 30 minutes during 3 test days of each treatment period. The average intraindividual coefficient of variation for the plasma levodopa concentrations after oral therapy was 34% and was significantly lower (14%, p < 0.01) during continuous infusion. Hourly video evaluations showed a significant increase in ON time during infusion and a significant decrease in OFF time and dyskinesia. Continuous intraduodenal delivery of a new carbidopa/levodopa formulation offers a means for markedly improved control of motor fluctuations in late stages of PD.

Administration, Oral↗

Levodopa infusion therapy in Parkinson disease: state of the art in 2004.

Orally administered levodopa, in combination with a decarboxylase inhibitor, is the gold standard therapy for Parkinson disease (PD). The problems in management of motor fluctuations in the advanced stages of the disorder are due to the close relationship between plasma levodopa levels and availability of dopamine at striatal receptor sites. The fluctuating levodopa concentrations are mainly explained by the fact that levodopa absorption only occurs in the proximal small intestine. The patient's motor function thus depends on gastric emptying, which is erratic and may even be delayed in PD. Oral therapy with sustained-release formulations and COMT inhibitors have not solved the problems satisfactorily. Therefore, infusions of levodopa by intravenous and enteral (duodenal/jejunal) routes of administration have been studied. In this review of the literature on clinically relevant levodopa infusion studies, it is shown that improvements regarding fluctuations in both plasma levodopa levels and motor performance have been repeatedly reported. The results acquired so far suggest that levodopa infusion is a safe and efficacious therapy. Recent drug delivery development and long-term studies have shown that infusion is a clinically feasible alternative to treat advanced PD.

Adult↗

[Conformationally altered proteins cause neurodegenerative diseases].

Brain aggregates of conformationally altered proteins are key features of neurodegeneration and are believed to directly cause or contribute to disease development. Mechanisms underlying the dysregulation of proteins in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and other neurodegenerative disorders are now being characterized, due to the discovery of genes causing rare disease forms. As of today, only symptomatic pharmacotherapies are available, but new insights into the underlying molecular mechanisms are providing strategies to prevent or even cure these devastating disorders.

Alzheimer Disease↗