Early diagnosis and therapy of Parkinson’s disease: can disease progression be curbed?

Electrochemical Aptasensors for Parkinson's Disease Biomarkers Detection

BACKGROUND

Biomarkers are characteristic molecules that can be measured as indicators of biological process status or condition, exhibiting special relevance in Parkinson's Disease (PD). This disease is a chronic neurodegenerative disorder very difficult to study given the site of pathology and due to a clinical phenotype that fluctuates over time. Currently there is no definitive diagnostic test, thus clinicians hope that the detection of crucial biomarkers will help to the symptomatic and presymptomatic diagnostics and providing surrogate endpoints to demonstrate the clinical efficacy of new treatments.

METHODS

Electrochemical aptasensors are excellent analytical tools that are used in the detection of PD biomarkers, as they are portable, easy to use, and perform real-time analysis.

RESULTS

In this review, we discuss the most important clinical biomarkers for PD, highlighting their physiological role and function in the disease. Herein, we review for the first time innovative aptasensors for the detection of current potential PD biomarkers based on electrochemical techniques and discuss future alternatives, including ideal analytical platforms for point-of-care diagnostics.

CONCLUSION

These new tools will be critical not only in the discovery of sensitive, specific, and reliable biomarkers of preclinical PD, but also in the development of tests that can assist in the early detection and differential diagnosis of parkinsonian disorders and in monitoring disease progression. Various methods for fixing aptamers onto the sensor surfaces, enabling quantitative and specific PD biomarker detection present in synthetic and clinical samples, will also be discussed.

New Insights into the Role of Ferritin in Iron Homeostasis and Neurodegenerative Diseases

Growing evidence has indicated that iron deposition is one of the key factors leading to neuronal death in the neurodegenerative diseases. Ferritin is a hollow iron storage protein composed of 24 subunits of two types, ferritin heavy chain (FTH) and ferritin light chain (FTL), which plays an important role in maintaining iron homeostasis. Recently, the discovery of extracellular ferritin and ferritin in exosomes indicates that ferritin might be not only an iron storage protein within the cell, but might also be an important factor in the regulation of tissue and body iron homeostasis. In this review, we first described the structural characteristics, regulation and the physiological functions of ferritin. Secondly, we reviewed the current evidence concerning the mechanisms underlying the secretion of ferritin and the possible role of secreted ferritin in the brain. Then, we summarized the relationship between ferritin and the neurodegenerative diseases including Parkinson's disease (PD), Alzheimer's disease (AD) and neuroferritinopathy (NF). Given the importance and relationship between iron and neurodegenerative diseases, understanding the role of ferritin in the brain can be expected to contribute to our knowledge of iron dysfunction and neurodegenerative diseases.

Assessment of real life eating difficulties in Parkinson's disease patients by measuring plate to mouth movement elongation with inertial sensors

Parkinson’s disease (PD) is a neurodegenerative disorder with both motor and non-motor symptoms. Despite the progressive nature of PD, early diagnosis, tracking the disease’s natural history and measuring the drug response are factors that play a major role in determining the quality of life of the affected individual. Apart from the common motor symptoms, i.e., tremor at rest, rigidity and bradykinesia, studies suggest that PD is associated with disturbances in eating behavior and energy intake. Specifically, PD is associated with drug-induced impulsive eating disorders such as binge eating, appetite-related non-motor issues such as weight loss and/or gain as well as dysphagia—factors that correlate with difficulties in completing day-to-day eating-related tasks. In this work we introduce Plate-to-Mouth (PtM), an indicator that relates with the time spent for the hand operating the utensil to transfer a quantity of food from the plate into the mouth during the course of a meal. We propose a two-step approach towards the objective calculation of PtM. Initially, we use the 3D acceleration and orientation velocity signals from an off-the-shelf smartwatch to detect the bite moments and upwards wrist micromovements that occur during a meal session. Afterwards, we process the upwards hand micromovements that appear prior to every detected bite during the meal in order to estimate the bite’s PtM duration. Finally, we use a density-based scheme to estimate the PtM durations distribution and form the in-meal eating behavior profile of the subject. In the results section, we provide validation for every step of the process independently, as well as showcase our findings using a total of three datasets, one collected in a controlled clinical setting using standardized meals (with a total of 28 meal sessions from 7 Healthy Controls (HC) and 21 PD patients) and two collected in-the-wild under free living conditions (37 meals from 4 HC/10 PD patients and 629 meals from 3 HC/3 PD patients, respectively). Experimental results reveal an Area Under the Curve (AUC) of 0.748 for the clinical dataset and 0.775/1.000 for the in-the-wild datasets towards the classification of in-meal eating behavior profiles to the PD or HC group. This is the first work that attempts to use wearable Inertial Measurement Unit (IMU) sensor data, collected both in clinical and in-the-wild settings, towards the extraction of an objective eating behavior indicator for PD.

Pharmacokinetics, Pharmacodynamics, and Safety of a Single Escalating Dose and Repeated Doses of Rasagiline Transdermal Patch in Healthy Chinese Subjects

A rasagiline transdermal patch can be used to offer continuous rasagiline to patients with Parkinson's disease who cannot take their usual oral medications. This was the first study to investigate the pharmacokinetics, pharmacodynamics, and safety of the rasagiline transdermal patch in healthy Chinese subjects. Thirty subjects were randomized to 3 groups with 10 subjects in each group. The 10 subjects of group 1 received a single 1-mg dose of rasagiline as a tablet; the 20 subjects of groups 2 and 3 received a single transdermal patch (48-hour patch-on period) containing 1.25 mg and 2.5 mg rasagiline, respectively. After a 2-week washout period, the subjects of group 1 were assigned to receive 1 mg of rasagiline tablets every 24 hours for 7 days, and the subjects of group 2 were assigned to receive 1.25-mg rasagiline transdermal patches (48-hour patch-on period) every 72 hours for 5 time periods. The absorption of rasagiline from the transdermal patch was significantly improved, although the peak plasma concentration was obviously reduced. There was slight accumulation of rasagiline dose after multiple administrations. Inhibition of platelet monoamine oxidase-B (MAO-B) activity was dose dependent. The 80% inhibition maintained for at least 48 hours after multiple-dose administration of 1 mg tablets, and for 72 hours after multiple-dose administration of 1.25 mg/48 h patch. Compared with rasagiline tablets, the transdermal patch had a prolonged duration of 80% inhibition and increased maximal inhibition of MAO-B activity. These characteristics permitted an interval of 3 days of dosing, which was convenient for patients to use.

Protective Effects of the Caffeine Against Neurodegenerative Diseases

Background:

Recent studies and increased interest of the scientific community helped to clarify the neurological health property of caffeine, one of the pharmacologically active substances most consumed in the world.

Methods:

This article is a review search to provide an overview on the current state of understanding neurobiochemical impact of caffeine, focusing on the ability of the drug to effectively counteract several neurodegenerative disorders such as Alzheimer’s, Parkinson’s, Huntington’s diseases, Multiple sclerosis and Amyotrophic lateral sclerosis.

Results:

Data collection shown in this review provide a significant therapeutic and prophylactic potentiality of caffeine which acts on human brain through several pathways because of its antioxidant activity combined with multiple molecular targets. However, the need to adjust the CF dosage to individuals, because some people are more sensitive to drugs than others, may constituted a limit to the CF effectiveness.

Conclusion:

What emerges from the complex of clinical and epidemiological studies is a significant CF potential impact against all neurological disorders. Although, further studies are needed to fully elucidate the several mechanisms of drug action which in part are still elusive.

Application of nanodiagnostics and nanotherapy to CNS diseases

Alzheimer's disease, Parkinson's disease and stroke are the most common CNS diseases, all characterized by progressive cellular dysfunction and death in specific areas of the nervous system. Therapeutic development for these diseases has lagged behind other disease areas due to difficulties in early diagnosis, long disease courses and drug delivery challenges, not least due to the blood-brain barrier. Over recent decades, nanotechnology has been explored as a potential tool for the diagnosis, treatment and monitoring of CNS diseases. In this review, we describe the application of nanotechnology to common CNS diseases, highlighting disease pathogenesis and the underlying mechanisms and promising functional outcomes that make nanomaterials ideal candidates for early diagnosis and therapy. Moreover, we discuss the limitations of nanotechnology, and possible solutions.

Current Pharmaceutical Treatments and Alternative Therapies of Parkinson's Disease

Over the decades, pharmaceutical treatments, particularly dopaminergic (DAergic) drugs have been considered as the main therapy against motor symptoms of Parkinson's disease (PD). It is proposed that DAergic drugs in combination with other medications, such as monoamine oxidase type B inhibitors, catechol-O-methyl transferase inhibitors, anticholinergics and other newly developed non-DAergic drugs can make a better control of motor symptoms or alleviate levodopa-induced motor complications. Moreover, non-motor symptoms of PD, such as cognitive, neuropsychiatric, sleep, autonomic and sensory disturbances caused by intrinsic PD pathology or drug-induced side effects, are gaining increasing attention and urgently need to be taken care of due to their impact on quality of life. Currently, neuroprotective therapies have been investigated extensively in pre-clinical studies, and some of them have been subjected to clinical trials. Furthermore, non-pharmaceutical treatments, including deep brain stimulation (DBS), gene therapy, cell replacement therapy and some complementary managements, such as Tai chi, Yoga, traditional herbs and molecular targeted therapies have also been considered as effective alternative therapies to classical pharmaceutics. This review will provide us updated information regarding the current drugs and non-drugs therapies for PD.

Avaliação eletromiográfica da deglutição dos diferentes tipos clínicos da doença de Parkinson nas fases on e off

OBJETIVO:avaliar os parâmetros eletromiográficos da deglutição dos diferentes tipos clínicos da doença de Parkinson idiopática nas fases on e off.MÉTODOS:foram estudados 20 pacientes com doença de Parkinson, divididos através da Escala Unificada de Avaliação da Doença de Parkinson em três grupos: tremulantes, rígido-acinético e misto. O exame de eletromiografia de superfície foi coletado sobre a musculatura supra-hióidea durante a deglutição de 3 ml e 10 ml de água e iogurte, que foi repetida 5 vezes para cada volume e consistência. Este protocolo foi realizado no antes e após a medicação, período offe on.RESULTADOS:verificou-se que na fase off, o grupo rígido-acinético apresentou as maiores médias de deglutições em partes e duração das eletromiografias de superfície, enquanto que o grupo misto apresentou as menores médias de amplitude. Na fase on, os três grupos tenderam a melhorar ou manter as médias das variáveis estudadas, porém não houve diferença significante entre os tipos clínicos, antes ou depois da Levodopa.CONCLUSÃO:a terapia medicamentosa através da Levodopa não apresenta diferenças consistentes nas eletromiografias de superfície da deglutição dos tipos clínicos da doença de Parkinson.

Universal screening test based on analysis of circulating organ-enriched microRNAs: a novel approach to diagnostic screening

Early disease detection leads to more effective and cost-efficient treatment. It is especially important for cancer and neurodegenerative diseases, because progression of these pathologies leads to significant and frequently irreversible changes in underlying pathophysiological processes. At the same time, the development of specific screening tests for detection of each of the hundreds of human pathologies in asymptomatic stage may be impractical. Here, we discuss a recently proposed concept: the development of minimally invasive Universal Screening Test (UST) based on analysis of organ-enriched microRNAs in plasma and other bodily fluids. The UST is designed to detect the presence of a pathology in particular organ systems, organs, tissues or cell types without diagnosing a specific disease. Once the pathology is detected, more specific, and if necessary invasive and expensive, tests can be administered to precisely define the nature of the disease. Here, we discuss recent studies and analyze the data supporting the UST approach.

Role of iron in UPS impairment model of Parkinson's disease

Iron homeostasis requires the regulation of iron influx, iron efflux and iron storage, which are all essential to the execution of the multiple functions of the central nervous system. Abnormal accumulation of iron in the brain has been implicated in several neurodegenerative diseases, including Parkinson's disease (PD) and neurodegeneration with brain iron accumulation (NBIA). Although the cause of the neurodegenerative process in PD remains unclear, recent evidence suggests that failure of the ubiquitin-proteasome system (UPS) may play an important role in the pathogenesis of this disease. Our studies have shown that injection of the proteasome inhibitor lactacystin in the substantia nigra (SN) of rodents causes significant loss of dopamine (DA) neurons and induces intracellular inclusion body formation, which is accompanied by excessive iron accumulation in the midbrain. In the in vitro model, lactacystin causes a marked increase in labile iron, reactive oxygen species, alteration of iron regulatory protein (IRP)/iron response element expression levels, and an increase in the aggregation of ubiquitin-conjugated proteins prior to cell injury and death. Furthermore, we have demonstrated that synthetic iron chelators and a genetic iron chelator are neuroprotective against proteasome inhibitor-induced DA neuron degeneration, suggesting that iron chelation might be a promising therapeutic target for PD.

The association of spectral-domain optical coherence tomography determined ganglion cell complex parameters and disease severity in Parkinson's disease

PURPOSE

To evaluate the association between the retinal structural changes provided by spectral domain optical coherence tomography (SD-OCT) and disease severity in Parkinson's disease (PD).

MATERIALS AND METHODS

Thirty-eight eyes of 20 patients with PD and 30 eyes of 30 healthy subjects were enrolled in this prospective study. The eyes ipsilateral (20 eyes) and contralateral (18 eyes) to the most affected body side in patients with PD were evaluated separately. SD-OCT (RTVue-100) was used to measure the macular ganglion cell complex thickness (mGCC), outer retinal thickness, and peripapillary retinal nerve fiber layer (RNFL) thickness. Disease severity was assessed using Unified Parkinson's Disease Rating Scale (UPDRS).

RESULTS

The differences in the nasal RNFL (p = 0.004), average mGCC (p = 0.014), superior mGCC (p = 0.007), inferior mGCC (p = 0.03) were significant between the ipsilateral eye group and controls. The differences in the nasal RNFL (p = 0.002), and superior mGCC (p = 0.038) were statisticallly significant between the contralateral eye group and controls. Inferior and average mGCC thicknesses of ipsilateral eyes were inversely correlated with UPDRS score (p = 0.001, r = -0.678 and p = 0.009, r = -0.568, respectively). Significant inverse correlation was demonstrated between UPDRS score and inferior RNFL of both eyes ipsilateral and contralateral to the most affected body side.

CONCLUSIONS

There is significant thinning in mGCC parameters of the retina in PD. The SD-OCT derived mGCC parameters may improve the detection of PD progression.