Nature’s role in modern medicine

Whether as patients or healthcare workers, it’s easy to overlook the origins of the drugs used to treat common diseases. In the era of recombinant technology and generally complex ways to design, test and use medicines, it’s refreshing when a drug crosses our path which is derived from nature in a simple yet brilliant way. Now, there are countless examples of these stories described in scientific literature, as well as within the mainstream media. Below are a few examples which I found particularly memorable.
I distinctly remember during my pharmacology final oral exam in medical school being asked a question. It was the very last question which the examiner asked me, and I was taken slightly aback by how simple it was yet how little I had thought about it before. He had grilled me for a good fifteen minutes about angiotensin converting enzyme inhibitors, a class of drugs used for treating hypertension among other conditions. Then, as I felt the exam drawing to a close he asked ‘How were ACE inhibitors discovered?’. Now, for a pharmacy student this question would be no problem at all, as they focus a lot of their time in studying how drugs are derived and synthesized. For me however, being immensely preoccupied with a wide range of subjects, the more clinical aspects of medicinal use being just one of them, it was something which I had hardly ever thought of.
ACE inhibitors were derived in the 1960s from the venom of the Brazilian pit viper, Bothrops jararaca. The venom leads to a severe drop in blood pressure by blocking the renin angiotensin aldosterone system. It is noteworthy that this selective mechanism of action means that ACE inhibitors may not be effective for everyone in terms of lowering blood pressure. However, the drugs have several other benefits including protecting the kidneys in diabetes and improving heart function in patients with heart failure.
Another interesting drug discovery story is that of exenatide , an anti diabetic agent licensed for use in 2005. This drug was isolated from lizard (Gila monster) saliva and has been shown to stimulate insulin release from the pancreas. Unlike other drugs with the same action, exenatide only increases insulin secretion when glucose levels are high and therefore does not lead to hypoglycemia. It also has numerous other beneficial effects including promoting weight loss.
My favorite, however, is the story behind a new thrombolytic treatment for stroke. The drug, now called desmoteplase, is derived from the saliva of the vampire bat Desmodus rotundus. This new drug is still in the testing phases of development (phase III trials), but has already shown great promise. It stays in the body for a longer time than other thrombolytics, is more selective in its action and does not lead to neurotoxicity. It is possible that it may represent a breakthrough in the treatment of stroke, which is currently a highly debated and complicated issue.

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Complexities

A clinician is complex. He is part craftsman, part practical scientist, and part historian.

A quote by Thomas Addis, a pioneer in the field of nephrology who was born in Edinburgh and studied medicine there, as well as at the Charit├ę in Berlin. One of his major contributions to clinical medicine was his emphasis on examining patients urine both with the naked eye and microscopically – which is now standard practice.

Holiday penumbras

In anticipation of my upcoming lab rotation at the Centre for Stroke Research in Berlin, I have been reading up on the focus of my project.
The ischemic penumbra is an area of a stroke patient’s brain which is dying as a result of the blockage of one of the arteries supplying the tissue. The keyword here is dying, not quite dead yet unlike the core of the tissue affected – which makes it a prime target for salvation in terms of stroke treatment. Left untreated, this penumbra transforms into dead brain tissue, and thus contributes to the patient’s permanent symptoms or neurological deficit. The region, which cannot be readily seen on more conventional imaging techniques like CT or standard MRI, was first noticed in PET scans, which basically measure the amount of energy the brain uses and maps it onto an image. Now, with the availability of more sophisticated MRI techniques such as diffusion and perfusion weighted imaging, this area can be mapped and its natural history identified, but most important is the fact that its response to treatment can be established. Simply, can this area be saved and to what degree, is the question on our minds.
The group which I am going to be working with has made much progress in this field, and what drew me to their projects most was their unique and innovative approach to the subject of stroke, which is a major killer and prominent cause of disability worldwide. For example, every doctor knows that stroke has a relatively short time window in which treatment can be given, and more importantly it is within this time window, typically around three hours from the onset of the stroke, that benefits of the treatment outweigh the risks. This time window was derived years ago from large studies which showed that only patients who received treatment within this time benefited from it. But now people are thinking of a new approach. Researchers are now trying to replace this seemingly arbitrary number of three hours with more objective and reliable criteria such as various signs on MRI, so that everyone who might benefit from treatment but falls outside of this window can have the opportunity to end up with less permanent disability than if doctors only relied on the time from stroke onset.
Needless to say I am very excited at the prospect of participating in something which has the potential to be so groundbreaking! Which is why I feel the need to be prepared, and that’s what I’m spending my holiday attempting to do. I will be posting more about this soon! ­čÖé

Back again …

Hello everyone! I’ve been gone a while, but now I’m back with some updates and the promise of a string of great posts in the next few weeks.
I had my Edinburgh assessment week a few weeks ago, it went smoothly, followed by my module final exam for my neuroscience course in Berlin. That also went surprisingly well, and now I have three weeks of R&R to look forward to. Well, not really.
The great news is that I flew back home to Sudan yesterday for the holidays. The ermmm … Other news is that I have a ton of stuff to do in my break, including gather some extra credit points by participating in some online courses, reading up on the topic of my upcoming lab rotation (*excitement*) and preparing for next year’s Edinburgh and Berlin modules. At least I’m looking forward to having more time to share my experiences with you via this blog this time, since I will be mainly working from home. ­čśÇ
First and foremost, I need to fix my sleeping pattern, (it’s almost 3am here) so good night!

What’s in a name? Sch├Ânleinstra├če

Photo 04.12.12 00 48 09U-Bahnhof (underground train station) Sch├Ânleinstra├če on the U8 in Kreuzberg, Berlin. The station is named after Johan Lukas Sch├Ânlein, German professor of medicine who taught for a while in Berlin. His name has been given to more than just this small station – he is recognized as one of the first people to describe a disease in children which involves the skin, joints and kidneys – now known as Henoch-Sch├Ânlein Purpura (HSP). He also first discovered one of the species belonging to a group of fungi known as the Dermatophytes (they love infecting skin, hair and nails), Trichophyton sch├Ânleini. Trichophyton species are considered the most common cause of Athlete’s foot (tinea pedis). Also something I found interesting is the species Trichophyton soudanense (Sudan?) – but I couldn’t find anything about the etymology of this organism online (maybe I need to dig a little deeper, all I found was that the organism is common in the Mediterranean and Africa). Perhaps I’m just a little homesick? ­čśŽ

First snow, Berlin!

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