Tag: L-dopa

Getting a GRP on dyskinesias

~ Simon ~ 8 Comments

# # # #

Dyskinesias are involuntary muscle movements associated with long-term use of levodopa therapy (use of levodopa is not a certainty for developing dyskinesias, but there is an association).

A better understanding of the underlying biology of dyskinesias is required in order to alleviate this condition for those affected by it.

This week researchers reported that a single protein – called RasGRP1 – plays a central role in the development of dykinesias, raising hope that agents targeting this protein could identified and provide better quality of life of sufferers.

In today’s post, we will discuss what dyskinesias are and review the new research.

# # # #

 

 

Few people outside of the biomedical sciences may have heard of the Scripps Research Institute, but it is the largest private, not-for-profit medical research facility in the United States and among the largest in the world. It is headquartered in La Jolla, California but it has a sister facility in Jupiter, Florida.

Nice spot to do research. Source: Scripps

Collectively, “The Scripps” has 250 laboratories, which employs over 2,400 scientists, technicians, graduate students, and administrative staff.

It was founded in 1924 by journalist/philanthropist Ellen Browning Scripps.

Ellen Browning Scripps. Source: Lajollalight

The Scripps covers a wide variety of area in biomedical research, but this week a group of researcher led by scientists at the Florida Scripps institute published an interesting report on Parkinson’s:

Title: RasGRP1 is a causal factor in the development of l-DOPA–induced dyskinesia in Parkinson’s disease
Authors: Eshraghi M, Ramírez-Jarquín1 UM, Shahani1 N, Nuzzo T, De Rosa A, Swarnkar S, Galli N, Rivera O, Tsaprailis G, Scharager-Tapia C, Crynen G, Li Q, Thiolat ML, Bezard E, Usiello A, Subramaniam S
Journal: Science Advances, May 2020, 6, 18, eaaz7001
PMID: 32426479                 (This report is OPEN ACCESS if you would like to read it)

In this study, the researchers were interested in proteins that could be playing a major role in the development of dyskinesias.

What are dyskinesias?

Continue reading “Getting a GRP on dyskinesias” →

When disco-needs-ya, can gene therapy help ya?

~ Simon ~ 4 Comments

 

With the recent announcement that the STEADY-PD III/Isradipine clinical trial did not reach its primary end point (that of slowing the progression of Parkinson’s), the winds of change have shifted with calls for a focus on biomarkers and better treatments, rather than disease modification.

Recently, researchers at Michigan State University have reported a novel experimental gene thearpy method for dealing with one of the most debilitating aspects of Parkinson’s – dyskinesias.

Ironically, their approach involves the same calcium channels that Isradipine blocks.

In today’s post, we will look at what dyskinesias are, what gene therapy is, and how this new approach could be useful for people currently burdened by these involutary movements.

 

Dyskinesia. Source: JAMA Neurology

There is a normal course of events following a diagnosis of Parkinson’s.

Yes, I am grossly over-generalising.

And no, I’m not talking from personal experience (this is based on listening to a lot of people), but just go with me on this for the sake of discussion.

First comes the shock of the actual diagnosis. For many it is devastating news – an event that changes the course of their lives. For others, however, the words ‘you have Parkinson’s‘ can provide a strange sense of relief that their current situation has a name and gives them something to focus on.

This initial phase is usually followed by the roller coaster of various emotions (including disbelief, sadness, anger, denial). It depends on each individual.

The emotional rollercoaster. Source: Asklatisha

And then comes the period during which many will try to familiarise themselves with their new situation. They will read books, search online for information, join Facebook groups (Click here for a good one), etc.

That search for information often leads to awareness of some of the realities of the condition.

And one potential reality that causes concern for many people (especially for people with young/early onset Parkinson’s) is dyskinesias.

What are dyskinesias?

Continue reading “When disco-needs-ya, can gene therapy help ya?” →

Xenon: A bright light for dyskinesias?

~ Simon ~ 13 Comments

A recent study published by French, British and Swiss researchers has grabbed the attention of some readers.

The report suggests that the inert/noble gas, Xenon, has powerful anti-dyskinetic properties in both mouse and primate models of Parkinson’s with L-DOPA-induced dyskinesias.

Dyskinesias are involuntary movements that can develop over time with prolonged used of L-DOPA treatments.

In today’s post, we will discuss what Xenon is, how it may be reducing dyskinesias, and we will consider some of the issues associated with using Xenon.

Dyskinesia. Source: JAMA Neurology

There is a normal course of events following a diagnosis of Parkinson’s.

Yes, I am grossly over-generalising, and no, I’m not talking from personal experience, but just go with me on this for the sake of discussion.

First comes the shock of the actual diagnosis. For many it is devastating news – an event that changes the course of their future. For others, however, the words ‘you have Parkinson’s‘ can provide a strange sense of relief that their current situation has a name and gives them something to focus on.

This initial phase is usually followed by the roller coaster of various emotions (including disbelief, sadness, anger, denial). It depends on each individual.

The emotional rollercoaster. Source: Asklatisha

And then comes the period during which many will try to familiarise themselves with their new situation. They will read books, search online for information, join Facebook groups (Click here for a good one), etc.

That search for information often leads to awareness of some of the realities of the condition.

And one potential reality that causes concern for many people (especially for people with early onset Parkinson’s) is dyskinesias.

What are dyskinesias?

Continue reading “Xenon: A bright light for dyskinesias?” →

Is there NOP hope for Parkinson’s?

~ Simon ~ 8 Comments

Please do not misread the title of this post!

Compounds targeting the Nociceptin receptor (or NOP) could provide the Parkinson’s community with novel treatment options in the not-too-distant future.

In pre-clinical models of Parkinson’s, compounds designed to block NOP have demonstrated neuroprotective properties, while drugs that stimulate NOP appear to be beneficial in reducing L-dopa induced dyskinesias. 

In today’s post we look at exactly what NOP is and what it does, we will review some of the Parkinson’s-based research that have been conducted so far, and we will look at what is happening in the clinic with regards to NOP-based treatments.

4237_20160422175355

Source: LUMS

On the surface of every cell in your body, there are lots of small proteins that are called receptors.

They are numerous and ubiquitous.

And they function act like a ‘light switch’ – allowing for certain biological processes to be initiated or inhibited. All a receptor requires to be activated (or blocked) is a chemical messenger – called a ligand – to come along and bind to it.

An example of a receptor on a cell. Source: Droualb

Each type of receptor has a particular structure, which is specific to certain shaped ligands (the chemical messenger I mentioned above). These ligands are floating around in the extracellular space (the world outside of the cell), having been released (or secreted) by other cells.

And this process represents one of the main methods by which cells communicate with each other.

By binding to a receptor, the ligand can either activate the receptor or alternatively block it. The activator ligands are called agonists, while the blockers are antagonists.

Agonists_and_antagonists

Agonist vs antagonist. Source: Psychonautwiki

Many of the drugs we currently have available in the clinic function in this manner.

For example, with Parkinson’s medications, some people will be taking Pramipexole (‘Mirapex’ and ‘Sifrol’) or Apomorphine (‘Apokyn’) to treat their symptoms. These drugs are Dopamine agonists because they bind to the dopamine receptors, and help with dopamine-mediated functions (dopamine being one of the chemicals that is severely in the Parkinsonian brain). As you can see in the image below the blue dopamine agonists can bypass the dopamine production process (which is reduced in Parkinson’s) and bind directly to the dopamine receptors on the cells that are the intended targets of dopamine.

Source: Bocsci

There are also dopamine antagonists (such as Olanzapine or ‘Zyprexa’) which blocks dopamine receptors. These drugs are not very helpful to Parkinson’s, but dopamine antagonist are commonly prescribed for people with schizophrenia.

Are there other receptors of interest in Parkinson’s?

Continue reading “Is there NOP hope for Parkinson’s?” →

Voyager Therapeutics: Phase I clinical trial update

~ Simon ~ 12 Comments

Today biotech company Voyager Therapeutics announced an update on their ongoing phase Ib clinical trial. The trial is evaluating the safety and tolerance of a gene therapy approach for people with advanced Parkinson’s.

Gene therapy is a technique that involves inserting new DNA into a cell using viruses. In this clinical trial, the virally delivered DNA helps the infected cell to produce dopamine in order to alleviate the motor features of Parkinson’s.

In today’s post we will discuss what gene therapy is, review the new results mentioned in the update, and look at other gene therapy approaches for Parkinson’s.


Source: Baltimoresun

Voyager Therapeutics is a clinical-stage gene therapy company that is focused on treatments for neurological conditions, such as Parkinson’s. Today the company announced an update of their ongoing Phase 1b trial of their product VY-AADC01 (Click here to see the press release).

VY-AADC01 represents a new class of treatment for Parkinson’s, as it is a form of gene therapy.

What is gene therapy?

The gene therapy involves introducing a piece of DNA into a cell which will cause the cell to produce proteins that they usually do not (either by nature or by mutation). The DNA is artificially inserted into cells and the cell’s protein producing machinery does the rest.

Source: Yourgenome

How does gene therapy work?

Continue reading “Voyager Therapeutics: Phase I clinical trial update” →

Trazodo or Trazodon’t?

~ Simon ~ 12 Comments

“Repurposing” in medicine refers to taking drugs that are already approved for the treatment of one condition and testing them to see if they are safe and effective in treating other diseases. Given that these clinically available drugs have already been shown to be safe in humans, repurposing represents a method of rapidly acquiring new potential therapeutics for a particular condition. 

The antidepressant, Trazodone, has recently been proposed for repurposing to neurodegenerative conditions, such as Parkinson’s. 

In today’s post we will look at what Trazodone is, why it is being considered for repurposing, and we will review the results of a new primate study that suggests it may not be ideal for the task.

Opinions. Everyone has them. Source: Creativereview

I am regularly asked by readers to give an opinion on specific drugs and supplements.

And I usually cut and paste in my standard response: I can not answer these sorts of questions as I am just a research scientist not a clinician; and even if I was a clinician, it would be unethical for me to comment as I have no idea of your medical history.

In many of these cases, there simply isn’t much proof that the drug/supplement has any effect in Parkinson’s, so it is hard to provide any kind of “opinion”. But even if there was proof, I don’t like to give opinions.

Eleven out of every ten opinions are usually wrong (except in the head of the beholder) so why would my opinion be any better? And each individual is so different, why would one particular drug/supplement work the same for everyone?

In offering an answer to “my opinion” questions, I prefer to stick to the “Just the facts, ma’am” approach and I focus solely on the research evidence that we have available (Useless pub quiz fact: this catchphrase “Just the facts, ma’am” is often credited to Detective Joe Friday from the TV series Dragnet, and yet he never actually said it during any episode! – Source).

Detective Joe Friday. Source: Wikipedia

Now, having said all of that, there is one drug in particularly that is a regular topic of inquiry (literally, not a week goes by without someone asking about): an antidepressant called Trazodone.

What is Trazodone?

Continue reading “Trazodo or Trazodon’t?” →

James: His legacy (Part 4)

~ Simon ~ 1 Comment

On Tuesday 21st December, 1824, James Parkinson passed away in his home – two days after suffering a stroke.

It was the end of an amazing and extremely productive life.

In this post about James Parkinson – the final in the series of four observing the 200th anniversary of his first observation of Parkinson’s disease – we look at what happened following his death, and reflect on his overall legacy.

St Leonard’s church in Hoxton, London – James’ church

At the end of the third post on the life of James Parkinson (Click here to read that post), the Battle of Waterloo had just occurred and James was publishing the last of his writings.

One of the last major events in the life of James Parkinson occurred in 1823, when James was awarded the Royal College of Surgeons’ first Gold Medal.

Understand that this was a big deal.

The college had established the award way back in 1802 for “distinguished labours, researches and discoveries”. But it took them a full 21 years to find anyone that they thought worthy enough to be the first recipient.

And that first recipient: one James Parkinson

This event, however, represents very nicely how the legacy of James has changed over time. While the world currently associates James Parkinson with a neurological condition that he first described in 1817, the Royal College of Surgeons awarded him their first gold medal not for any of his medical publications, but rather for his “splendid Work on Organic Remains”.

parkinson3

Source: Lindahall

As I have written before, James was a bit of a rockstar to the geological/palaeontology community. His writings on what he called his “favourite science”, had earned him an international reputation and one has to wonder how he would feel now if he knew that his reputation lies elsewhere.

As JP aficionado Dr Cherry Lewis once wrote: history is fickle.

Continue reading “James: His legacy (Part 4)” →

The Acorda’s Tozadenant Phase III clinical trials

~ Simon ~ 6 Comments

The biotech company Acorda Therapeutics Inc. yesterday announced that it was halting new recruitment for the phase III program of its drug Tozadenant (an oral adenosine A2a receptor antagonist).

In addition, participants currently enrolled in the trial will now have their blood monitoring conducted on a weekly basis. 

The initial report looks really bad (tragically five people have died), but does this tragic news mean that the drug should be disregarded?

In todays post, we will look at what adenosine A2a receptor antagonists are, how they may help with Parkinson’s, and discuss what has happened with this particular trial.

Dr Ron Cohen, CEO of Acorda. Source: EndpointNews

Founded in 1995, Acorda Therapeutics Ltd is a biotechnology company that is focused on developing therapies that restore function and improve the lives of people with neurological disorders, particularly Parkinson’s disease.

Earlier this year, they had positive results in their phase III clinical trial of Inbrija (formerly known as CVT-301 – Click here to read a previous post about this). They have subsequently filed a New Drug Application with the US Food and Drug Administration (FDA) to make this inhalable form of L-dopa available in the clinic, but the application has been delayed due to manufacturing concerns from the FDA (Click here to read more about this). These issues should be solvable – the company and the FDA are working together on these matters – and the product will hopefully be available in the new year.

So what was the news yesterday?

Acorda Therapeutics has another experimental product going through the clinical trial process for Parkinson’s disease.

It’s called Tozadenant.

Source: Focusbio

Tozadenant is an oral adenosine A2a receptor antagonist (and yes, we’ll discuss what all that means in a moment).

Yesterday Acorda Therapeutics Inc announced that they have halted new recruitment for their phase III clinical program. In addition the company is increasing the frequency of blood cell count monitoring (from monthly to weekly) for participants already enrolled in the company’s Phase 3 program of Tozadenant for Parkinson’s disease.

The Company took this action due to reports of cases of agranulocytosis.

Continue reading “The Acorda’s Tozadenant Phase III clinical trials” →

Clinical trials: The Power of One

~ Simon ~ 12 Comments

As the age of personalised medicine approaches, innovative researchers are rethinking the way we conduct clinical studies. “Rethinking” in radical ways – think: individualised clinical trials! 

One obvious question is: Can you really conduct a clinical trial involving just one participant?

In this post, we will look at some of the ideas and evaluate the strengths and weaknesses these approaches.

A Nobel prize medal. Source: Motley

In the annals of Nobel prize history, there are a couple winners that stands out for their shear….um, well,…audacity.

One example in particular, was the award given to physician Dr Werner Forssmann. In 1956, Andre Cournand, Dickinson Richards and Forssmann were awarded the Nobel Prize in Physiology or Medicine “for their discoveries concerning heart catheterisation and pathological changes in the circulatory system”. Forssmann was responsible for the first part (heart catheterisation).

Source: Nobelprize

In 1929, at the age of 25, Forssmann performed the first human cardiac catheterisation – that is a procedure that involves inserting a thin, flexible tube directly into the heart via an artery (usually in the arm, leg or neck). It is a very common procedure performed on a daily basis in any hospital today. But in 1929, it was revolutionary. And the audacious aspect of this feat was that Forssmann performed the procedure on himself!

And if you think that is too crazy to be true, please read on.

But be warned: this particular story gets really bonkers.

Continue reading “Clinical trials: The Power of One” →

Trying to ‘beet’ Parkinson’s in the developing world

~ Simon ~ 3 Comments

Recently I discussed my ‘Plan B’ idea, which involves providing a cheap alternative to expensive drugs for folks living in the developing world with Parkinson’s (Click here for that post).

While doing some research for that particular post, I came across another really interesting bit of science that is being funded by Parkinson’s UK.

It involves Beetroot.

In today’s post we will look at how scientists are attempting turn this red root vegetable into a white root vegetable in an effort to solve Parkinson’s in the developing world.

Pompeii and Mount Vesuvius. Source: NationalGeo

During visits to the ancient Roman city of Pompeii (in Italy), tourists are often drawn by their innocent curiosity to the ‘red light’ district of the city. And while they are there, they are usually amused by the ‘descriptive’ murals that still line the walls of the buildings in that quarter.

So amused in fact that they often miss the beetroots.

Huh? Beetroots?

Yes, beetroots.

I’m not suggesting that anyone spends a great deal of time making a close inspection of the walls, but if you look very carefully, you will often see renditions of beetroots.

They are everywhere. For example:

Two beetroots hanging from the ceiling.

Again: Huh?

The Romans considered beetroot to be quite the aphrodisiac, believing that the juice ‘promoted amorous feelings’. They also ate the red roots for medicinal purposes, consuming it as a laxative or to cure fever.

And this medicinal angle lets me segway nicely into the actual topic of today’s post. You see, in the modern era researcher are hoping to use beetroot for medicinal purposes again. But this time, the beetroot will be used to solve an issue close to my heart: treating people with Parkinson’s in the developing world.

Using beetroot to treat Parkinson’s?

Continue reading “Trying to ‘beet’ Parkinson’s in the developing world” →