The role of native cysteine residues in the oligomerization of KCNQ1 channels.

KCNQ1, the major component of the slow-delayed rectifier potassium channel, is responsible for repolarization of cardiac action potential. Mutations in this channel can lead to a variety of diseases, most notably long QT syndrome. It is currently unknown how many of these mutations change channel function and structure on a molecular level. Since tetramerization is key to proper function and structure of the channel, it is likely that mutations modify the stability of KCNQ1 oligomers. Presently, the C-terminal domain of KCNQ1 has been noted as the driving force for oligomer formation. However, truncated versions of this protein lacking the C-terminal domain still tetramerize. Therefore, we explored the role of native cysteine residues in a truncated construct of human KCNQ1, amino acids 100-370, by blocking potential interactions of cysteines with a nitroxide based spin label. Mobility of the spin labels was investigated with continuous wave electron paramagnetic resonance (CW-EPR) spectroscopy. The oligomerization state was examined by gel electrophoresis. The data provide information on tetramerization of human KCNQ1 without the C-terminal domain. Specifically, how blocking the side chains of native cysteines residues reduces oligomerization. A better understanding of tetramer formation could provide improved understanding of the molecular etiology of long QT syndrome and other diseases related to KCNQ1.

Purification and membrane interactions of human KCNQ1100-370 potassium ion channel.

KCNQ1 (Kv7.1 or KvLQT1) is a voltage-gated potassium ion channel that is involved in the ventricular repolarization following an action potential in the heart. It forms a complex with KCNE1 in the heart and is the pore forming subunit of slow delayed rectifier potassium current (Iks). Mutations in KCNQ1, leading to a dysfunctional channel or loss of activity have been implicated in a cardiac disorder, long QT syndrome. In this study, we report the overexpression, purification, biochemical characterization of human KCNQ1100-370, and lipid bilayer dynamics upon interaction with KCNQ1100-370. The recombinant human KCNQ1 was expressed in Escherichia coli and purified into n-dodecylphosphocholine (DPC) micelles. The purified KCNQ1100-370 was biochemically characterized by SDS-PAGE electrophoresis, western blot and nano-LC-MS/MS to confirm the identity of the protein. Circular dichroism (CD) spectroscopy was utilized to confirm the secondary structure of purified protein in vesicles. Furthermore, 31P and 2H solid-state NMR spectroscopy in DPPC/POPC/POPG vesicles (MLVs) indicated a direct interaction between KCNQ100-370 and the phospholipid head groups. Finally, a visual inspection of KCNQ1100-370 incorporated into MLVs was confirmed by transmission electron microscopy (TEM). The findings of this study provide avenues for future structural studies of the human KCNQ1 ion channel to have an in depth understanding of its structure-function relationship.

Simple Derivatization of RAFT-Synthesized Styrene-Maleic Anhydride Copolymers for Lipid Disk Formulations.

Styrene-maleic acid copolymers have received significant attention because of their ability to interact with lipid bilayers and form styrene-maleic acid copolymer lipid nanoparticles (SMALPs). However, these SMALPs are limited in their chemical diversity, with only phenyl and carboxylic acid functional groups, resulting in limitations because of sensitivity to low pH and high concentrations of divalent metals. To address this limitation, various nucleophiles were reacted with the anhydride unit of well-defined styrene-maleic anhydride copolymers in order to assess the potential for a new lipid disk nanoparticle-forming species. These styrene-maleic anhydride copolymer derivatives (SMADs) can form styrene-maleic acid derivative lipid nanoparticles (SMADLPs) when they interact with lipid molecules. Polymers were synthesized, purified, characterized by Fourier-transform infrared spectroscopy, gel permeation chromatography, and nuclear magnetic resonance and then used to make disk-like SMADLPs, whose sizes were measured by dynamic light scattering (DLS). The SMADs form lipid nanoparticles, observable by DLS and transmission electron microscopy, and were used to reconstitute a spin-labeled transmembrane protein, KCNE1. The polymer method reported here is facile and scalable and results in functional and robust polymers capable of forming lipid nanodisks that are stable against a wide pH range and 100 mM magnesium.

Physiotherapy for Parkinson's disease: a comparison of techniques.

BACKGROUND: Despite medical therapies and surgical interventions for Parkinson's disease (PD), patients develop progressive disability. The role of physiotherapy is to maximise functional ability and minimise secondary complications through movement rehabilitation within a context of education and support for the whole person. The overall aim is to optimise independence, safety and wellbeing, thereby enhancing quality of life. Trials have shown that physiotherapy has short-term benefits in PD. However, which physiotherapy intervention is most effective remains unclear. OBJECTIVES: To assess the effectiveness of one physiotherapy intervention compared with a second approach in patients with PD. SEARCH METHODS: Relevant trials were identified by electronic searches of numerous literature databases (for example MEDLINE, EMBASE) and trial registers, plus handsearching of major journals, abstract books, conference proceedings and reference lists of retrieved publications. The literature search included trials published up to the end of January 2012. SELECTION CRITERIA: Randomised controlled trials of one physiotherapy intervention versus another physiotherapy intervention in patients with PD. DATA COLLECTION AND ANALYSIS: Data were abstracted independently from each paper by two authors. Trials were classified into the following intervention comparisons: general physiotherapy, exercise, treadmill training, cueing, dance and martial arts. MAIN RESULTS: A total of 43 trials were identified with 1673 participants. All trials used small patient numbers (average trial size of 39 participants); the methods of randomisation and concealment of allocation were poor or not stated in most trials. Blinded assessors were used in just over half of the trials and only 10 stated that they used intention-to-treat analysis.A wide variety of validated and customised outcome measures were used to assess the effectiveness of physiotherapy interventions. The most frequently reported physiotherapy outcomes were gait speed and timed up and go, in 19 and 15 trials respectively. Only five of the 43 trials reported data on falls (12%). The motor subscales of the Unified Parkinson's Disease Rating Scale and Parkinson's Disease Questionnaire-39 were the most commonly reported clinician-rated disability and patient-rated quality of life outcome measures, used in 22 and 13 trials respectively. The content and delivery of the physiotherapy interventions varied widely in the trials included within this review, so no quantitative meta-analysis could be performed. AUTHORS' CONCLUSIONS: Considering the small number of participants examined, the methodological flaws in many of the studies, the possibility of publication bias, and the variety of interventions, formal comparison of the different physiotherapy techniques could not be performed. There is insufficient evidence to support or refute the effectiveness of one physiotherapy intervention over another in PD.This review shows that a wide range of physiotherapy interventions to treat PD have been tested . There is a need for more specific trials with improved treatment strategies to underpin the most appropriate choice of physiotherapy intervention and the outcomes measured.

Physiotherapy versus placebo or no intervention in Parkinson's disease.

BACKGROUND: Despite medical therapies and surgical interventions for Parkinson's disease (PD), patients develop progressive disability. Physiotherapy aims to maximise functional ability and minimise secondary complications through movement rehabilitation within a context of education and support for the whole person. The overall aim is to optimise independence, safety, and well-being, thereby enhancing quality of life. OBJECTIVES: To assess the effectiveness of physiotherapy intervention compared with no intervention in patients with PD. SEARCH METHODS: We identified relevant trials by conducting electronic searches of numerous literature databases (e.g. MEDLINE, EMBASE) and trial registers, and by handsearching major journals, abstract books, conference proceedings, and reference lists of retrieved publications. The literature search included trials published up to the end of January 2012. SELECTION CRITERIA: Randomised controlled trials of physiotherapy intervention versus no physiotherapy intervention in patients with PD. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data from each article. We used standard meta-analysis methods to assess the effectiveness of physiotherapy intervention compared with no physiotherapy intervention. Trials were classified into the following intervention comparisons: general physiotherapy, exercise, treadmill training, cueing, dance, and martial arts. We used tests for heterogeneity to assess for differences in treatment effect across these different physiotherapy interventions. MAIN RESULTS: We identified 39 trials with 1827 participants. We considered the trials to be at a mixed risk of bias as the result of unreported allocation concealment and probable detection bias. Compared with no intervention, physiotherapy significantly improved the gait outcomes of speed (mean difference 0.04 m/s, 95% confidence interval (CI) 0.02 to 0.06, P = 0.0002); two- or six-minute walk test (13.37 m, 95% CI 0.55 to 26.20, P = 0.04) and Freezing of Gait questionnaire (-1.41, 95% CI -2.63 to -0.19, P = 0.02); functional mobility and balance outcomes of Timed Up & Go test (-0.63 s, 95% CI -1.05 to -0.21, P = 0.003), Functional Reach Test (2.16 cm, 95% CI 0.89 to 3.43, P = 0.0008), and Berg Balance Scale (3.71 points, 95% CI 2.30 to 5.11, P < 0.00001); and clinician-rated disability using the Unified Parkinson's Disease Rating Scale (UPDRS) (total -6.15 points, 95% CI-8.57 to -3.73, P < 0.00001; activities of daily living: -1.36, 95% CI -2.41 to -0.30, P = 0.01; and motor: -5.01, 95% CI -6.30 to -3.72, P < 0.00001). No difference between arms was noted in falls (Falls Efficacy Scale: -1.91 points, 95% CI -4.76 to 0.94, P = 0.19) or patient-rated quality of life (PDQ-39 Summary Index: -0.38 points, 95% CI -2.58 to 1.81, P = 0.73). One study reported that adverse events were rare; no other studies reported data on this outcome. Indirect comparisons of the different physiotherapy interventions revealed no evidence that the treatment effect differed across physiotherapy interventions for any of the outcomes assessed. AUTHORS' CONCLUSIONS: Benefit for physiotherapy was found in most outcomes over the short term (i.e. < 3 months) but was significant only for speed, two- or six-minute walk test, Freezing of Gait questionnaire, Timed Up & Go, Functional Reach Test, Berg Balance Scale, and clinician-rated UPDRS. Most of the observed differences between treatments were small. However, for some outcomes (e.g. speed, Berg Balance Scale, UPDRS), the differences observed were at, or approaching, what are considered minimal clinically important changes. These benefits should be interpreted with caution because the quality of most of the included trials was not high. Variation in measurements of outcome between studies meant that our analyses include a small proportion of the participants recruited.This review illustrates that a wide range of approaches are employed by physiotherapists to treat patients with PD. However, no evidence of differences in treatment effect was noted between the different types of physiotherapy interventions being used, although this was based on indirect comparisons. A consensus menu of 'best practice' physiotherapy is needed, as are large, well-designed randomised controlled trials undertaken to demonstrate the longer-term efficacy and cost-effectiveness of 'best practice' physiotherapy in PD.

Physiotherapy intervention in Parkinson's disease: systematic review and meta-analysis.

OBJECTIVE: To assess the effectiveness of physiotherapy compared with no intervention in patients with Parkinson's disease. DESIGN: Systematic review and meta-analysis of randomised controlled trials. DATA SOURCES: Literature databases, trial registries, journals, abstract books, and conference proceedings, and reference lists, searched up to the end of January 2012. REVIEW METHODS: Randomised controlled trials comparing physiotherapy with no intervention in patients with Parkinson's disease were eligible. Two authors independently abstracted data from each trial. Standard meta-analysis methods were used to assess the effectiveness of physiotherapy compared with no intervention. Tests for heterogeneity were used to assess for differences in treatment effect across different physiotherapy interventions used. Outcome measures were gait, functional mobility and balance, falls, clinician rated impairment and disability measures, patient rated quality of life, adverse events, compliance, and economic analysis outcomes. RESULTS: 39 trials of 1827 participants met the inclusion criteria, of which 29 trials provided data for the meta-analyses. Significant benefit from physiotherapy was reported for nine of 18 outcomes assessed. Outcomes which may be clinically significant were speed (0.04 m/s, 95% confidence interval 0.02 to 0.06, P<0.001), Berg balance scale (3.71 points, 2.30 to 5.11, P<0.001), and scores on the unified Parkinson's disease rating scale (total score -6.15 points, -8.57 to -3.73, P<0.001; activities of daily living subscore -1.36, -2.41 to -0.30, P=0.01; motor subscore -5.01, -6.30 to -3.72, P<0.001). Indirect comparisons of the different physiotherapy interventions found no evidence that the treatment effect differed across the interventions for any outcomes assessed, apart from motor subscores on the unified Parkinson's disease rating scale (in which one trial was found to be the cause of the heterogeneity). CONCLUSIONS: Physiotherapy has short term benefits in Parkinson's disease. A wide range of physiotherapy techniques are currently used to treat Parkinson's disease, with little difference in treatment effects. Large, well designed, randomised controlled trials with improved methodology and reporting are needed to assess the efficacy and cost effectiveness of physiotherapy for treating Parkinson's disease in the longer term.

Physiotherapy versus placebo or no intervention in Parkinson's disease.

BACKGROUND: Despite medical therapies and surgical interventions for Parkinson's disease (PD), patients develop progressive disability. The role of physiotherapy aims to maximise functional ability and minimise secondary complications through movement rehabilitation within a context of education and support for the whole person. The overall aim is to optimise independence, safety and well-being, thereby enhancing quality of life. OBJECTIVES: To assess the effectiveness of physiotherapy intervention compared with no intervention in patients with PD. SEARCH METHODS: We identified relevant trials by electronic searches of numerous literature databases (e.g. MEDLINE, EMBASE) and trial registers, plus handsearching of major journals, abstract books, conference proceedings and reference lists of retrieved publications. The literature search included trials published up to end of December 2010. SELECTION CRITERIA: Randomised controlled trials of physiotherapy intervention versus no physiotherapy intervention in patients with PD. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data from each article. We used standard meta-analysis methods to assess the effectiveness of physiotherapy intervention compared with no physiotherapy intervention. Trials were classified into the following intervention comparisons: general physiotherapy, exercise, treadmill training, cueing, dance and martial arts. We used tests for heterogeneity to assess for differences in treatment effect across these different physiotherapy interventions. MAIN RESULTS: We identified 33 trials with 1518 participants. Compared with no-intervention, physiotherapy significantly improved the gait outcomes of velocity (mean difference 0.05 m/s, 95% confidence interval (CI): 0.02 to 0.07, P = 0.0002), two- or six-minute walk test (16.40 m, CI: 1.90 to 30.90, P = 0.03) and step length (0.03 m, CI: 0 to 0.06, P = 0.04); functional mobility and balance outcomes of Timed Up & Go test (-0.61 s, CI: -1.06 to -0.17, P = 0.006), Functional Reach Test (2.16 cm, CI: 0.89 to 3.43, P = 0.0008) and Berg Balance Scale (3.36 points, CI: 1.91 to 4.81, P < 0.00001); and clinician-rated disability using the Unified Parkinson's Disease Rating Scale (UPDRS) (total: -4.46 points, CI -7.16 to -1.75, P = 0.001; activities of daily living: -1.36, CI -2.41 to -0.30, P = 0.01; and motor: -4.09, CI: -5.59 to -2.59, P < 0.00001). There was no difference between arms in falls or patient-rated quality of life. Indirect comparisons of the different physiotherapy interventions found no evidence that the treatment effect differed across the physiotherapy interventions for any of the outcomes assessed. AUTHORS' CONCLUSIONS: Benefit for physiotherapy was found in most outcomes over the short-term (i.e. < three months), but was only significant for velocity, two- or six-minute walk test, step length, Timed Up & Go, Functional Reach Test, Berg Balance Scale and clinician-rated UPDRS. Most of the observed differences between the treatments were small. However, for some outcomes (e.g. velocity, Berg Balance Scale and UPDRS), the differences observed were at, or approaching, what are considered minimally clinical important changes.The review illustrates that a wide range of approaches are employed by physiotherapists to treat PD. However, there was no evidence of differences in treatment effect between the different types of physiotherapy interventions being used, though this was based on indirect comparisons. There is a need to develop a consensus menu of 'best-practice' physiotherapy, and to perform large well-designed randomised controlled trials to demonstrate the longer-term efficacy and cost-effectiveness of 'best practice' physiotherapy in PD.

Physiotherapy versus placebo or no intervention in Parkinson's disease.

BACKGROUND: Despite medical therapies and surgical interventions for Parkinson's disease (PD), patients develop progressive disability. The role of physiotherapy aims to maximise functional ability and minimise secondary complications through movement rehabilitation within a context of education and support for the whole person. The overall aim is to optimise independence, safety and well-being, thereby enhancing quality of life. OBJECTIVES: To assess the effectiveness of physiotherapy intervention compared with no intervention in patients with PD. SEARCH METHODS: We identified relevant trials by electronic searches of numerous literature databases (e.g. MEDLINE, EMBASE) and trial registers, plus handsearching of major journals, abstract books, conference proceedings and reference lists of retrieved publications. The literature search included trials published up to end of December 2010. SELECTION CRITERIA: Randomised controlled trials of physiotherapy intervention versus no physiotherapy intervention in patients with PD. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data from each article. We used standard meta-analysis methods to assess the effectiveness of physiotherapy intervention compared with no physiotherapy intervention. Trials were classified into the following intervention comparisons: general physiotherapy, exercise, treadmill training, cueing, dance and martial arts. We used tests for heterogeneity to assess for differences in treatment effect across these different physiotherapy interventions. MAIN RESULTS: We identified 33 trials with 1518 participants. Compared with no-intervention, physiotherapy significantly improved the gait outcomes of velocity (mean difference 0.05 m/s, 95% confidence interval (CI): 0.02 to 0.07, P = 0.0002), two- or six-minute walk test (16.40 m, CI: 1.90 to 30.90, P = 0.03) and step length (0.03 m, CI: 0 to 0.06, P = 0.04); functional mobility and balance outcomes of Timed Up & Go test (-0.61 s, CI: -1.06 to -0.17, P = 0.006), Functional Reach Test (2.16 cm, CI: 0.89 to 3.43, P = 0.0008) and Berg Balance Scale (3.36 points, CI: 1.91 to 4.81, P < 0.00001); and clinician-rated disability using the Unified Parkinson's Disease Rating Scale (UPDRS) (total: -4.46 points, CI -7.16 to -1.75, P = 0.001; activities of daily living: -1.36, CI -2.41 to -0.30, P = 0.01; and motor: -4.09, CI: -5.59 to -2.59, P < 0.00001). There was no difference between arms in falls or patient-rated quality of life. Indirect comparisons of the different physiotherapy interventions found no evidence that the treatment effect differed across the physiotherapy interventions for any of the outcomes assessed. AUTHORS' CONCLUSIONS: Benefit for physiotherapy was found in most outcomes over the short-term (i.e. < three months), but was only significant for velocity, two- or six-minute walk test, step length, Timed Up & Go, Functional Reach Test, Berg Balance Scale and clinician-rated UPDRS. Most of the observed differences between the treatments were small. However, for some outcomes (e.g. velocity, Berg Balance Scale and UPDRS), the differences observed were at, or approaching, what are considered minimally clinical important changes.The review illustrates that a wide range of approaches are employed by physiotherapists to treat PD. However, there was no evidence of differences in treatment effect between the different types of physiotherapy interventions being used, though this was based on indirect comparisons. There is a need to develop a consensus menu of 'best-practice' physiotherapy, and to perform large well-designed randomised controlled trials to demonstrate the longer-term efficacy and cost-effectiveness of 'best practice' physiotherapy in PD.

Helicobacter pylori eradication for Parkinson's disease.

BACKGROUND: Levodopa is the mainstay of treatment for alleviating the motor symptoms associated with Parkinson's disease. However, patients often experience fluctuations in their symptoms over time and 'wearing off' which may be partly related to variable absorption of the drug. There is some evidence that treatment of the common gastrointestinal infection Helicobacter pylori (H pylori) with antibiotics may improve levodopa absorption in the gut and hence improve symptoms. OBJECTIVES: 1) What is the prevalence of H pylori in Parkinson's disease patients? 2) Does treatment of H pylori infection with antibiotics improve symptoms in Parkinson's disease patients? Is this effect dependent on improvements in the absorption of levodopa? SEARCH METHODS: We searched electronic databases (including CENTRAL, MEDLINE, EMBASE, PsycINFO and CINAHL) and trial registers, handsearched conference proceedings and carried out citation searching on key articles. All searching was updated in August 2009. We contacted authors to provide additional information where necessary. SELECTION CRITERIA: Clinical trials in patients with a well-defined definition of Parkinson's disease and who were H pylori-positive. Two people independently selected studies for inclusion using predetermined criteria. We used recruitment figures from clinical trials and other studies identified from the searching to determine the prevalence of H pylori in Parkinson's disease. DATA COLLECTION AND ANALYSIS: Two authors abstracted data from the source papers and assessed methodological quality independently. We presented results descriptively. MAIN RESULTS: Two completed and one ongoing clinical trial met the inclusion criteria. One trial (34 patients randomised) examined the effects of H pylori eradication on levodopa absorption and motor symptoms and found significant improvements in both. The ongoing trial has similar objectives and aims to recruit 100 patients. The other completed trial (20 patients analysed) sought to find a causal link between infection with H pylori and Parkinsonism and was non-contributory. A worsening of symptoms was noted with eradication failure.The prevalence of H pylori in Parkinson's disease was reported in four studies and ranged from 37% to 59% which is similar to that of the general population. AUTHORS' CONCLUSIONS: There is currently a lack of evidence on the effects of screening and treating H pylori in patients with Parkinson's disease. There is limited evidence to suggest that H Pylori eradication improves the absorption of levodopa and improves motor symptoms. Results from an ongoing trial will inform the evidence base and will be incorporated in an update of this review. There is a need for well-conducted randomised controlled trials with standard outcome measures for motor symptoms and incorporating the costs of screening and treatment.

Non-steroidal anti-inflammatory drugs as disease-modifying agents for Parkinson's disease: evidence from observational studies.

BACKGROUND: Neuroinflammation may play a key role in the neurodegeneration associated with Parkinson's disease (PD). Non-steroidal anti-inflammatory drugs (NSAIDs) may be beneficial in the primary and secondary prevention of PD. OBJECTIVES: 1) Do NSAIDs prevent the onset of PD?2) Are NSAIDs neuroprotective in PD - do they slow the progression of disease once PD is established?3) What are the adverse effects of taking NSAIDs in PD? SEARCH METHODS: We searched electronic databases, including trial registers, complemented with handsearching of conference proceedings and citation searching on key articles. All searching was updated in May 2011. We contacted authors to provide additional information where necessary. SELECTION CRITERIA: For the primary prevention review, we sought primary prevention trials and observational studies (cohort and case-control studies). Participants were free of PD when exposure to NSAIDs was assessed. For the secondary prevention review, we sought clinical trials in patients with a well-defined definition of PD. Two people independently selected studies for inclusion using predetermined criteria. DATA COLLECTION AND ANALYSIS: Two review authors abstracted data from the source papers and assessed methodological quality independently. No studies met the inclusion criteria for the secondary prevention review. For the primary prevention review only observational studies were found. We combined data where appropriate using the inverse variance method. We assessed methodological quality using the Newcastle Ottawa Scales and by examining the period of exposure assessed prior to PD onset (or the index date in controls). MAIN RESULTS: Fourteen observational studies met the inclusion criteria for the primary prevention review (five cohort, nine case-control studies). Exposure to any NSAIDs or aspirin had no effect on the risk of developing PD. Exposure to non-aspirin NSAIDs reduced the risk of developing PD by 13% (effect estimate 0.87 (95% CI 0.73 to 1.04 - random-effects model), but this did not reach statistical significance. We found similar results for the most robust studies. Ibuprofen in isolation was examined in four studies and was associated with a 27% reduction in risk (effect estimate 0.73, 95% CI 0.63 to 0.85). There was a lack of information on adverse effects. AUTHORS' CONCLUSIONS: There is currently no evidence for the use of NSAIDs in the secondary prevention of PD. Non-aspirin NSAIDs, particularly ibuprofen, may reduce the risk of developing PD. However, little is known of the effects of other individual drugs and at present no recommendations can be made regarding their use in primary prevention.

Anti-hypertensive drugs as disease-modifying agents for Parkinson's disease: evidence from observational studies and clinical trials.

BACKGROUND: Current treatment for Parkinson's disease (PD) is focused on relieving symptoms, at present there is nothing that is widely accepted to halt or slow disease progression. Potential neuroprotective or disease modifying agents have been identified from preclinical studies. One such group of compounds are anti-hypertensive drugs. OBJECTIVES: 1) Do anti-hypertensive drugs prevent the onset of PD? (primary prevention)2) Are anti-hypertensive drugs disease modifying agents in PD, do they slow the progression of disease once PD is established? (secondary prevention)3) What are the adverse effects of taking anti-hypertensive drugs for patients with PD? SEARCH METHODS: Electronic databases including trial registers were searched, complemented with handsearching of conference proceedings and searching the citations of key articles (updated May 2011). Authors were contacted, to provide additional information, where necessary. SELECTION CRITERIA: For the primary prevention review, primary prevention trials and observational studies (cohort and case control studies) were sought. Participants were free of PD when exposure to anti-hypertensive drugs was assessed. For the secondary prevention review, clinical trials in patients with well defined PD were sought. Two people independently selected studies for inclusion using predetermined criteria. DATA COLLECTION AND ANALYSIS: Data were abstracted from the source papers and methodological quality was assessed independently by two review authors. Results for both reviews were dealt with descriptively. MAIN RESULTS: Two cohort studies and four case control studies met the inclusion criteria for the primary prevention review. The two cohort studies found no effect of exposure to calcium channel blockers on the risk of developing PD. Three case control studies looked at the effects of exposure to calcium channel blockers and beta blockers on the risk of developing PD but the assessment periods of exposure were markedly different prior to PD onset, and different subclasses of drugs were examined, so results were not comparable. A protective effect of centrally acting calcium channel blockers was found in one study.Two trials and one ongoing trial met the inclusion criteria for the secondary prevention review. Each completed trial examined a different class of anti-hypertensive drug. The ongoing trial is examining the effects of the calcium channel blocker isradipine on motor symptoms and disease progression. It follows an earlier tolerability study. The results are due in the year 2012.Adverse effects were noted in all included trials and included intolerability to the drugs and worsening PD symptoms. AUTHORS' CONCLUSIONS: There is currently a lack of evidence for the use of antihypertensive drugs for either the primary or secondary prevention of PD. More observational studies are required to identify potential drugs to go forward for safety and tolerability studies in people with early PD. The results of the ongoing trial will help inform further research.

Meta-analysis of the comparative efficacy and safety of adjuvant treatment to levodopa in later Parkinson's disease.

BACKGROUND: Levodopa initially provides good symptomatic control of the symptoms of Parkinson's disease, but motor complications often develop after long-term use. Other classes of antiparkinsonian drugs including dopamine agonists, catechol-O-methyl transferase inhibitors, or monoamine oxidase type B inhibitors are then added as adjuvant therapy. It is unclear whether one class of drug is more effective than another. This meta-analysis evaluates the comparative benefits and risks of these agents as adjuvant treatment in Parkinson's disease patients with motor complications. METHODS: A systematic review of the literature from 1966 to the end of June 2010 was conducted to identify randomized trials involving a dopamine agonist, catechol-O-methyl transferase inhibitor, or monoamine oxidase type B inhibitor versus placebo, as adjuvant to levodopa therapy. RESULTS: Forty-five trials involving nearly 9,000 participants were included. The meta-analysis confirms reports from individual trials that compared with placebo, adjuvant therapy significantly reduces patient off-time and levodopa dose, with improved symptom severity scores (e.g., Unified Parkinson's Disease Rating Scale). However, dyskinesia and numerous other side effects are increased with adjuvant therapy. Few randomized comparisons between drugs have been undertaken, but indirect comparisons suggest that dopamine agonist therapy may be more effective than catechol-O-methyl transferase inhibitor and monoamine oxidase type B inhibitor therapy, which have comparable efficacy. No differences between drugs within each class were observed other than the catechol-O-methyl transferase inhibitor tolcapone appearing more efficacious than entacapone. DISCUSSION: This meta-analysis highlights the need for direct head-to-head randomized trials to assess the impact of adjuvant therapy on patient-rated quality of life and health economic outcomes.

Systematic review of levodopa dose equivalency reporting in Parkinson's disease.

Interpretation of clinical trials comparing different drug regimens for Parkinson's disease (PD) is complicated by the different dose intensities used: higher doses of levodopa and, possibly, other drugs produce better symptomatic control but more late complications. To address this problem, conversion factors have been calculated for antiparkinsonian drugs that yield a total daily levodopa equivalent dose (LED). LED estimates vary, so we undertook a systematic review of studies reporting LEDs to provide standardized formulae. Electronic database and hand searching of references identified 56 primary reports of LED estimates. Data were extracted and the mean and modal LEDs calculated. This yielded a standardized LED for each drug, providing a useful tool to express dose intensity of different antiparkinsonian drug regimens on a single scale. Using these conversion formulae to report LEDs would improve the consistency of reporting and assist the interpretation of clinical trials comparing different PD medications.

Evaluation of the efficacy and safety of adjuvant treatment to levodopa therapy in Parkinson s disease patients with motor complications.

BACKGROUND: One of the complications of long-term treatment of Parkinson's disease (PD) with levodopa is the development of motor complications. Generally, when motor complications develop, clinicians add in an additional drug (to the levodopa regimen) from one of three other classes of anti-Parkinsonian treatments (dopamine agonists, catechol-O-methyl transferase inhibitors (COMTIs) or monoamine oxidase type B inhibitors (MAOBIs)). However, despite trials having shown that these drugs are beneficial compared to placebo, it remains unclear as to the best way to treat patients experiencing motor complications and whether one class of drug is more effective than another. OBJECTIVES: This meta-analysis aims to assess more reliably the benefits and risks of the three classes of drugs (dopamine agonists, COMTIs and MAOBIs) currently used as adjuvant treatment to levodopa in PD patients suffering from motor complications. The three drug classes were compared with the aim of determining whether one class of drug provides better symptomatic control than another. SEARCH STRATEGY: We searched CENTRAL (The Cochrane Library), MEDLINE, EMBASE, PubMed, LILACS and Web of Science, plus major journals in the field, abstract books, conference proceedings and reference lists of retrieved publications. SELECTION CRITERIA: Randomised trials comparing an orally administered dopamine agonist, COMTI or MAOBI versus placebo, both on a background of levodopa therapy, in PD patients experiencing motor complications. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data on off-time, levodopa dose, motor complications, side-effects, treatment concordance, clinician-rated disability, mortality, quality of life and health economic data. MAIN RESULTS: Forty-four eligible trials, involving 8436 participants were identified. Compared to placebo, adjuvant therapy significantly reduced off-time (-1.05 hours/day, 95% confidence interval (CI) -1.19 to -0.90; P<0.00001), the required levodopa dose (-55.65 mg/day, CI -62.67 to -48.62; P<0.00001) and improved UPDRS scores (UPDRS ADL score: -1.31 points, CI -1.62 to -0.99; P<0.00001; UPDRS motor score: -2.84 points, CI -3.36 to -2.32; P<0.00001; UPDRS total score: -3.26 points, CI -4.52 to -2.00; P<0.00001). However, dyskinesia (odds ratio (OR) 2.50, CI 2.21 to 2.84; P<0.00001) and side-effects including constipation (OR 3.19, CI 2.17 to 4.68; P<0.00001), dizziness (OR 1.57, CI 1.30 to 1.90; P<0.00001), dry mouth (OR 2.33, CI 1.22 to 4.47; P=0.01), hallucinations (OR 2.16, CI 1.70 to 2.74; P<0.00001), hypotension (OR 1.47, CI 1.18 to 1.83; P=0.0007), insomnia (OR 1.38, CI 1.09 to 1.74; P=0.007), nausea (OR 1.78, CI 1.53 to 2.07; P<0.00001), somnolence (OR 1.87, CI 1.40 to 2.51; P<0.0001) and vomiting (OR 2.56, CI 1.67 to 3.93; P<0.0001) were all increased with adjuvant therapy.Indirect comparisons of the three drug classes suggested that dopamine agonists were more efficacious in reducing off-time (dopamine agonist: -1.54 hours/day; COMTI: -0.83 hours/day; MAOBI: -0.93 hours/day; test for heterogeneity between drug classes P=0.0003) and levodopa dose (dopamine agonist: -116 mg/day; COMTI: -52 mg/day; MAOBI: -29 mg/day; test for heterogeneity between drug classes P<0.00001). UPDRS scores also improved more with dopamine agonists than with COMTI or MAOBI (UPDRS total scores - dopamine agonist: -10.01 points versus COMTI: -1.46 points versus MAOBI: -2.20 points; test for heterogeneity between drug classes P<0.00001), although more dyskinesia were seen with dopamine agonists (OR 2.70) and COMTI (OR 2.50) than with MAOBI (OR 0.94) (test for heterogeneity between drug classes P=0.009). Although the increase in the overall incidence of side-effects was generally more marked with dopamine agonists (OR 1.52) and COMTI (OR 2.0) than with MAOBI (OR 1.32), heterogeneity between drug classes was only of borderline significance (P=0.07). AUTHORS' CONCLUSIONS: Compared to placebo, adjuvant therapy reduces off-time, levodopa dose, and improves UPDRS scores in PD patients who develop motor complications on levodopa therapy. However, this is at the expense of increased dyskinesia and numerous other side-effects. Indirect comparisons suggest that dopamine agonist therapy may be more effective than COMTI and MAOBI therapy, which have comparable efficacy. However, as indirect comparisons should be interpreted with caution, direct head-to-head randomised trials assessing the impact of these different drug classes on overall patient-rated quality of life are needed.

Monoamine oxidase B inhibitors versus other dopaminergic agents in early Parkinson's disease.

BACKGROUND: It has been postulated that monoamine oxidase B (MAO-B) inhibitors alter disease progression in Parkinson's disease (PD) but trials have produced conflicting results. OBJECTIVES: To assess the effectiveness and safety of long-term use of MAO-B inhibitors compared with other dopaminergic agents in early PD. SEARCH STRATEGY: We searched several electronic databases including: the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 1, 2009), MEDLINE (January 1950 to February 2009) and EMBASE (January 1980 to February 2009). We also handsearched neurology and movement disorders conference proceedings, checked reference lists of relevant studies and contacted other researchers. SELECTION CRITERIA: We included all randomised controlled trials that compared a MAO-B inhibitor with other dopaminergic agents (presently levodopa or dopamine agonists) in patients with early PD, where treatment and follow up lasted at least one year. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected trials for inclusion, assessed the methodological quality, and extracted the data. Additional data were provided by the original authors. Random-effects models were used to analyse results, where appropriate. MAIN RESULTS: Only two eligible trials were included (593 patients), both of reasonable quality although one was unblinded. Both trials compared selegiline with a dopamine agonist, whilst one also compared selegiline with levodopa. MAO-B inhibitors were not associated with a significant increase or decrease in deaths compared with levodopa (odds ratio (OR) 0.96; 95% confidence interval (CI) 0.52 to 1.76) or dopamine agonists (OR 1.30; 95% CI 0.69 to 2.45). Those receiving MAO-B inhibitors were more likely to require add-on therapy during follow-up than those receiving levodopa (OR 12.02; 95% CI 6.78 to 21.31) or dopamine agonist (OR 2.00; 95% CI 1.05 to 3.81). There was a reduction in motor fluctuations with MAO-B inhibitors compared with levodopa (OR 0.55; 95% CI 0.32 to 0.94) but not dopamine agonists (OR 1.15; 95% CI 0.65 to 2.05). Withdrawals due to adverse events were less common with MAO-B inhibitors than with dopamine agonists (OR 0.11; 95% CI 0.01 to 0.99). AUTHORS' CONCLUSIONS: MAO-B inhibitors are one option for the early treatment of PD although they have weaker symptomatic effects than levodopa and dopamine agonists. They may reduce the rate of motor fluctuations compared with initial levodopa therapy and may have fewer significant adverse effects than the older agonists but data are too few to provide reliable conclusions.

Chemotherapy compared with biochemotherapy for the treatment of metastatic melanoma: a meta-analysis of 18 trials involving 2,621 patients.

PURPOSE: To assess the effect of adding interferon-alpha (IFN) +/- interleukin-2 (IL-2) to chemotherapy in patients with metastatic melanoma. METHODS A published data meta-analysis of trials of biochemotherapy versus chemotherapy in patients with metastatic melanoma was undertaken. End points evaluated were rates of partial response (PR), complete response (CR) and overall (partial + complete) response (OR); response duration; progression-free survival; overall survival (OS); and toxicity. The only subgroup analysis performed was by type of immunotherapy, with trials divided according to whether IFN only or IFN and IL-2 were administered in the biochemotherapy arm. RESULTS: Eighteen randomized trials were identified: 11 trials of chemotherapy +/- IFN and seven trials of chemotherapy +/- IFN and IL-2. More than 2,600 patients were entered onto the trials, with 555 responses and 2,039 deaths. There was a clear benefit for biochemotherapy for PR (odds ratio = 0.66; 95% CI, 0.53 to 0.82; P = .0001), CR (odds ratio = 0.50; 95% CI, 0.35 to 0.73; P = .0003) and OR (odds ratio = 0.59; 95% CI, 0.49 to 0.72; P < .00001). For OR, these benefits were significant for both the IFN (odds ratio = 0.60; 95% CI, 0.46 to 0.79; P = .0002) and IFN + IL-2 (odds ratio = 0.58; 95% CI, 0.44 to 0.77; P = .0001) subgroups. In contrast, there was no benefit overall in OS (odds ratio = 0.99; 95% CI, 0.91 to 1.08; P = .9), but there was evidence of heterogeneity of treatment effect between the individual trials (P = .006). CONCLUSION: This meta-analysis provides a comprehensive summary of all the data currently available, and shows that although biochemotherapy clearly improves response rates, this does not appear to translate into a survival benefit.

Monoamine oxidase type B inhibitors in early Parkinson's disease: meta-analysis of 17 randomised trials involving 3525 patients.

OBJECTIVE: To quantify more reliably the benefits and risks of monoamine oxidase type B inhibitors (MAOBIs) in early Parkinson's disease. DATA SOURCES: Searches of the Cochrane Library, Medline, Embase, PubMed, and Web of Science for years 1966-2003, plus major journals in the field, abstract books, and proceedings of meetings, for randomised trials comparing MAOBIs with placebo or levodopa. DATA EXTRACTION: Available data on mortality, motor complications, side effects, treatment compliance, and clinician rated disability (for example, unified Parkinson's disease rating scale) were extracted from 17 trials and combined using standard meta-analytic methods. RESULTS: No significant difference in mortality existed between patients on MAOBIs and control patients (odds ratio 1.13, 95% confidence interval 0.94 to 1.34; P = 0.2). Patients randomised to MAOBIs had significantly better total scores, motor scores, and activities of daily living scores on the unified Parkinson's disease rating scale at three months compared with patients taking placebo; they were also less likely to need additional levodopa (0.57, 0.48 to 0.67; P < 0.00001) or to develop motor fluctuations (0.75, 0.59 to 0.95; P = 0.02). No difference existed between the two groups in the incidence of side effects or withdrawal of patients. CONCLUSIONS: MAOBIs reduce disability, the need for levodopa, and the incidence of motor fluctuations, without substantial side effects or increased mortality. However, because few trials have compared MAOBIs with other antiparkinsonian drugs, uncertainty remains about the relative benefits and risks of MAOBIs. Further large, long term comparative trials that include patient rated quality of life measures are needed.

Continuing uncertainty about the value of percutaneous revascularization in atherosclerotic renovascular disease: a meta-analysis of randomized trials.

BACKGROUND: To study the effect of revascularization on blood pressure (BP) and serum creatinine (SCr) in patients with atherosclerotic renovascular disease (ARVD). METHODS: Three randomized studies comparing balloon angioplasty (plus medication if necessary) with medical therapy alone in patients with ARVD were identified. In one study, patients were stratified and analysed according to whether they had unilateral or bilateral disease. Therefore, four sets of results were available for inclusion in a meta-analysis comparing BP and SCr at 6 months and changes from baseline. RESULTS: The three trials recruited 210 patients. There was no clear benefit for angioplasty when comparing BP at 6 months. Relative to the medical therapy group, the mean (95% CI) systolic/diastolic BP was 2.9 mmHg (-9.1, 3.4)/0.35 mmHg (-3.6, 2.9) lower in the angioplasty group (P=0.4/0.8). There was, however, some suggestion of benefit for angioplasty when changes in BP were compared. There was a greater reduction in the systolic/diastolic BP in the angioplasty group, with a difference of 6.3 mmHg (-11.7, -0.8)/3.3 mmHg (-6.2, -0.4) in the mean change (P=0.02/0.03). There was some suggestion of benefit for angioplasty in terms of changes in SCr, although this was not significant (P=0.06). CONCLUSIONS: The reported trials have been too small to determine reliably the role of angioplasty in ARVD. Although the combined results of three previous trials exclude the possibility of a large improvement in renal function or hypertension after angioplasty, a moderate but clinically worthwhile benefit cannot be ruled out. Further large-scale randomized evidence is needed.