malaria – Highlight HEALTH http://www.highlighthealth.com Discover the Science of Health Mon, 16 Oct 2017 05:31:50 +0000 en-US hourly 1 https://wordpress.org/?v=4.8.2 Scientists Detect Malaria in 15 Minutes with 20-cent Paper Centrifuge http://www.highlighthealth.com/medical-device-technology/scientists-detect-malaria-15-minutes-20-cent-paper-centrifuge/ Sat, 14 Jan 2017 19:32:25 +0000 http://www.highlighthealth.com/?p=13092 PaperfugeStanford bioengineers have created an ultra-low-cost, hand-spun centrifuge that separates blood into its individual components in only 1.5 minutes.]]> Paperfuge

Stanford bioengineers have created an ultra-low-cost, hand-spun centrifuge that separates blood into its individual components in only 1.5 minutes [1]. Inspired by an ancient children’s toy called a whirligig, the “paperfuge” can be used to detect malaria in blood in just 15 minutes.

Paperfuge

Fundamental to any medical diagnostics facility, centrifuges are used hospitals, clinics and laboratories around the world to separate fluids into different components by spinning the specimen. During the high-speed spin, centrifugal forces push denser material outwards. The centrifuge is used to separate cell, subcellular organelles, proteins, viruses, and nucleic acids. While centrifuges are crucial in regions of the world where tropical diseases are common, they often aren’t available due to high cost, weight and electricity needs.

Published in the journal Nature Biomedical Engineering [2], a Stanford research team describes a new device dubbed the “paperfuge.” The study demonstrates the separation of pure plasma from whole blood in less than 1.5 minutes and isolation of malaria parasites in 15 minutes. Built from 20-cents worth of paper, twine and plastic, the paperfuge can reach speeds of 125,000 revolutions per minute and exert centrifugal forces equivalent to 30,000 g’s. That’s approximately 100x faster than previous non-electrical efforts and is considered the fastest rotational speed ever recorded for a human-powered device.

Some of the most urgent global health problems today demand innovative solutions that are both inexpensive and scalable. The study authors write that “the simplicity of manufacturing our proposed device will enable immediate mass distribution of a solution urgently needed in the field. Ultimately, our present work serves as an example of frugal science: leveraging the complex physics of a simple toy for global health applications.”

The paperfuge is the third invention from Manu Prakash’s bioengineering lab at Stanford University. Driven by a frugal design philosophy, bioengineers rethink traditional medical tools to lower costs and bring scientific capabilities out of the lab and into hands of health care workers in resource-poor areas.

References

  1. Inspired by a whirligig toy, Stanford bioengineers develop a 20-cent, hand-powered blood centrifuge. Stanford University. 2017 Jan10.
  2. Bhamla et al. Hand-powered ultralow-cost paper centrifuge. Nature Biomedical Engineering 1, Article number: 0009 (2017). doi:10.1038/s41551-016-0009
]]>
Anti-parasite Drugs and the Nobel Prize for Medicine http://www.highlighthealth.com/health-news/anti-parasite-drugs-and-the-nobel-prize-for-medicine/ Fri, 09 Oct 2015 03:14:09 +0000 http://www.highlighthealth.com/?p=12600 The 2015 Nobel Prize in Physiology or Medicine was announced earlier this week [1]. The prize was awarded to three scientists who developed therapies by looking at natural, local substances, against parasitic infections. The prize of 8-million-Swedish-krona ($1.2-million USD) was divided, with one half jointly to Drs. William C. Campbell, age 85, at Drew University in Madison, New Jersey,]]>

nobel medal in medicine

The 2015 Nobel Prize in Physiology or Medicine was announced earlier this week [1]. The prize was awarded to three scientists who developed therapies by looking at natural, local substances, against parasitic infections.

The prize of 8-million-Swedish-krona ($1.2-million USD) was divided, with one half jointly to Drs. William C. Campbell, age 85, at Drew University in Madison, New Jersey, USA, and Satoshi Omura, age 80, at Kitasato University in Tokyo, Japan, for their work on a novel therapy against infections caused by roundworm parasites, and the other half to Dr. Youyou Tu, age 85, at the China Academy of Traditional Chinese Medicine in Beijing, China, for her work on a novel therapy against Malaria.

Parasitic infections are a major global health problem

Parasitic infections are a global health problem of unbelievable magnitude. Two out of three people worldwide are afflicted with a parasitic disease, and most people who harbor parasites actually are afflicted with a range of diseases.

The Nobel Assembly at Karolinska Institutet in Sweden said in a statement [1]:

Diseases caused by parasites have plagued humankind for millennia and constitute a major global health problem. In particular, parasitic diseases affect the world’s poorest populations and represent a huge barrier to improving human health and wellbeing. This year’s Nobel Laureates have developed therapies that have revolutionized the treatment of some of the most devastating parasitic diseases.

Parasitic diseases

Ascariasis, a disease caused by the parasitic roundworm Ascaris lumbricoides, is the most common human worm infection. Worldwide, severe Ascaris infections cause approximately 60,000 deaths per year, mainly in children [2]. In the 1970s, Campbell and Omura discovered a class of compounds, called avermectins, that kill parasitic roundworms that cause infections such as river blindness (onchocerciasis) and lymphatic filariasis (elephantiasis). In Japan, Omura isolated strains of soil bacteria that were known to have antimicrobial properties. Omura’s institute signed a research partnership with Merch in 1973, and in 1974 his soil bacteria strains were sent to a team led by Campbell at the Merck Institute for Therapeutic Research in Rahway, New Jersey. Campbell’s team isolated avermectins from the bacterial cultures and developed the drug ivermectin. In 1987, Merck announced that it would donate ivermectin to anyone who needed it for treatment of river blindness. Ten years later, the company began giving away the drug to treat lymphatic filariasis. According to the Mectizan Donation Program, every year Merck gives away some 270 million treatments of the drug,

Malaria is a historic problem and one of the oldest human diseases, perhaps 50,000-100,000 years old. In the 1960s, the main treatments for malaria were becoming increasingly ineffective. In 1967, China established a national project against malaria to discover new therapies. Tu and her team screened more than 2,000 Chinese herbal remedies in search of drugs with antimalarial activity. An extract from the wormwood plant Artemisia annua proved especially effective and by 1972, the researchers had isolated chemically pure artemisinin. See the video below for more.

This year’s prize highlights the global acknowledgement on the importance of parasitic infections and neglected tropical diseases. Artemisinin  has saved hundreds of thousands, if not millions of lives, and ivermectin has protected millions from disease.

References

  1. The 2015 Nobel Prize in Physiology or Medicine – Press Release. Nobelprize.org. 5 Oct 2015.
  2. Water related diseases, World Health Organization. Accessed 2015 Oct 8.
]]>
Open Source Drug Discovery for Malaria http://www.highlighthealth.com/open-science/open-source-drug-discovery-for-malaria/ Wed, 28 Dec 2011 17:10:01 +0000 http://www.highlighthealthtech.com/?p=782 Open Source Drug Discovery for Malaria is a project launched earlier this year by The Synaptic Leap, a non-profit organization for open source biomedical research.]]>

The term “open source” describes practices in production and development that promote access to the end product’s source materials. I’m sure you’ve heard of open source software such as Perl, WordPress, Linux and Android, and are familiar with open content projects such as Wikipedia and Wiktionary, but what about open source drug discovery?

Specifically, Open Source Drug Discovery (OSDD) for Malaria is a project launched earlier this year by The Synaptic Leap (TSL), a non-profit organization for open source biomedical research. They focus on providing online tools to allow researchers to coordinate efforts and exchange knowledge. Project members can participate in online discussions, author blogs, and use aggregated RSS feeds to stay current with news and research.

Open Source Drug Discovery for Malaria

Why malaria? Because malaria is one of the most serious public health problems in tropical and sub-tropical regions of the world.

Malaria is a potentially fatal blood disease caused by a human parasite called Plasmodium falciparum. Malaria is transmitted to human and animal hosts by the female anopheles mosquito. Although the disease can be treated in just 48 hours, it can cause fatal complications if the diagnosis and treatment are delayed.

Malaria is a disease of several different strains; five species of Plasmodium can infect and be transmitted by humans. Malaria is currently the fifth cause of death from infectious diseases worldwide, following respiratory infections, HIV/AIDS, diarrheal diseases, and tuberculosis, and the second cause of death in Africa, following HIV/AIDS.

OSDD Malara is a hub for global efforts in open source drug discovery for malaria. The initial participants of OSDD Malaria are the lab of Dr. Matthew Todd, an organic chemist, at the University of Sydney and the Medicines for Malaria Venture (MMV). Other participants in the project include scientists from the University of Melbourne and Griffith University in Australia, and GlaxoSmithKline in Madrid. As an open science project, anyone can come and join, and participation is encouraged at any level.

OSDD Malaria will be holding an open source drug discovery for malaria meeting in Sydney, Australia on February 24th, 2012. The meeting, like the organization’s data, is open to all and will hopefully be live-streamed to a global audience. The aim is to work out how best to do open source drug discovery. More details will be coming soon.

If you want to get involved, you can sign up for The Synaptic Leap updates (by joining), follow Matthew Todd on Google+ (where data is often presented), or follow the OSDD Malaria Twitter feed.

The OSDD Malaria project status is described on the OSDD Malaria wiki.

]]>
Synergy Between Antibiotics and Nonantibiotic Drugs http://www.highlighthealth.com/research/synergy-between-antibiotics-and-nonantibiotic-drugs/ Tue, 17 May 2011 05:54:32 +0000 http://www.highlighthealth.com/?p=7440 Antibiotic cocktailA recent study has found new combinations of antibiotics and nonantibiotic drugs that enhance antimicrobial efficacy.]]> Antibiotic cocktail

Antibiotic resistance is an ever-growing clinical problem. Four years ago, a study found that antibiotics are overprescribed for sinus infections. Compounding the issue is the fact that as bacteria are learning to tolerate and even circumvent existing classes of antibiotics, not enough work is being done to discover new ones. Combinations or cocktails of antibiotics are often used to broaden the antimicrobial spectrum of each and to achieve synergistic effects; this approach has successfully been applied to combat tuberculosis, leprosy, malaria, and famously, HIV. Yet the discovery of effective combinations has usually been almost fortuitous, most often resulting from trial and error rather than a systematic analysis.

Antibiotic cocktail

In the current study, researchers systematically examined combinations of 1,057 compounds previously approved as drugs to find those that exhibited synergy with the antibiotic minocycline. Their work is reported in the April 24, 2011 issue of the journal Nature Chemical Biology [1]. The compounds were chosen because they have already been approved as drugs, they are known to have activity in vivo and are known to be relatively safe. Many approved drugs are known to have utility for clinical indications other than those for which they initially received approval. Moreover, using pre-approved compounds also reduces the time and cost associated with developing new compounds for therapeutic use.

The compounds were combined with half of the minimal inhibitory concentration of minocycline and then applied to three strains of bacteria: two pathogens resistant to minocycline, Pseudomanas aeruginosa and Staphylococcus aureus, as well as Escheria coli. About half of the compounds that initially synergized with minocycline were other antibiotics, and thus were not interesting to these researchers — they were looking for new types of chemicals, against which bacteria would not know how to fight. After those were eliminated, there were 69 nonantibiotic compounds, never before used clinically to treat bacterial infection, found to synergize with minocycline.

Disulfiram, a drug used to treat alcoholism, had only weak antibiotic activity against S. aureus when used alone, but strongly synergized with minocycline to inhibit growth of S. aureus — even some strains of MRSA (methicillin-resistant staphylococcus aureus). Six compounds synergized with minocycline to inhibit the growth of P. aeruginosa, and they were initially approved for very different uses: (1) loperamide, known more commonly by its trade name, Imodium, is used to treat diarrhea; (2) mitomycin C is a chemotherapeutic agent; (3) vitamin C; (4) benserazide is used to treat Parkinson’s disease; (5) tegaserod is used to treat irritable bowel syndrome; and (6) chloroxine is used to treat dandruff. As with S. aureus, multidrug resistant versions of P. aeruginosa were also susceptible to combinations of these compounds with minocycline.

Loperamide was a particularly interesting case. It also synergized with eight other tetracycline antibiotics, those in the same class as minocycline. These antibiotics work by inhibiting protein synthesis in bacteria. Since loperamide has no antibacterial activity when used alone, the researchers delved into figuring out how the synergy might work. They found that loperamide increased the permeability of the bacteria’s outer membrane, which enhances the bug’s uptake of tetracyclines. When the tetracyclines then inhibit the synthesis of outer membrane proteins, this then enhances loperamide’s effects in what’s called a “positive feedback loop”.

A challenge in finding effective drug concentrations is that the drugs need to be be able to get where they are needed in tandem. Fortunately, loperamide and minocycline can bothe be taken orally. The researchers thus used a mouse model to confirm what they had found when the combination was applied to bacteria growing in petri dishes. Salmonella enterica is a pathogen that resides in the intestine. The combination of loperamide and minocycline decreased the number of bacteria in these mice as much as a million times, but each agent alone had no effect.

The scientists also collected data suggesting that different combinations might be used to specifically target different species of bacteria. This newly found synergy, especially that against multidrug resistant strains of bacteria, will hopefully buy humanity a little more time in our ongoing battle with microbial pathogens.

References

  1. Ejim et al. Combinations of antibiotics and nonantibiotic drugs enhance antimicrobial efficacy. Nat Chem Biol. 2011 Apr 24. [Epub ahead of print]
    View abstract
]]>