Using drugs to block bacteria from entering human cells...
New Strategy Being Developed in the War on Infectious Diseases
January 11, 2012 - Many of the drugs we use to fight infections lose their effectiveness as the targeted pathogens acquire resistance to them. So researchers have begun adopting a new strategy. Instead of using drugs to kill the offending pathogens, they're trying to design drugs that can block their entry into human cells before they can cause disease.
Sooner or later, says Abhay Satoskar, a professor of pathology at Ohio State University, drug resistance becomes a problem in the battle against disease-causing organisms or pathogens. “Any time you have an agent that targets a pathogen, the pathogens are smart and eventually come up with a strategy to make that drug or agent ineffective,” said Satoskar. Most bacteria, viruses and parasites must enter human immune system cells to reproduce and cause illness. Satoskar is leading an effort at Ohio State to develop a compound that blocks a pathogen’s entry into the cells.
The experimental drug targets a natural cell enzyme, called P13K, that allows pathogens to pass through the cell wall. The compound changes the chemical activity of P13K, blocking entry into cells. The team demonstrated the effectiveness of the cell-blocking strategy with the parasite that causes leishmaniasis, a tropical illness caused by a parasite transmitted in the bite of a sand fly. Also known as leishmania, an estimated 1.5 million new cases are diagnosed each year. The disease causes disfiguring open sores on the skin. Not only is the illness indigenous in many parts of the world, but experts say it is now turning up in U.S. troops returning home from Afghanistan.
There is a drug to treat leishmania, says Satoskar, that’s up to 90 percent effective in curing the disease. But Satoskar says the medication has a lot of side effects, including anemia, weight loss and neurological problems, and many people don’t complete the 21-day course of injections. Using laboratory mice, Satoskar says researchers compared the effectiveness of the existing drug to the targeted, therapy his team is developing. Satoskar says the new agent worked just as well in treating leishmania, and the cell-blocking strategy could potentially work against other disease-causing organisms or pathogens.
“Now the issue is how to do you fine-tune it? And that could be fine tune(d) based on different pathogens, because different pathogens could use different pathways to get in,” Satoskar said. Satoskar also is interested in learning whether the experimental compound could be used as a skin spray to prevent infection with leishmania when someone is bitten by a sand fly. An article on preventing leishmania by blocking parasites from mice immune cells is published in the journal Proceedings of the National Academy of Sciences.
Touch wood, I've not yet had it.
To add,, mosquito borne deseases kill more than a million people every year globally, mainly in developing countries.
Last edited by lizarddust; Jan 15 2012 at 05:20 PM.
Most murderers are caught and punished unless they kill in large numbers and to the sound of trumpets
Typhoid outbreak in Zimbabwe...
Zimbabwe doctors report 800 typhoid cases
Sun Jan 29,`12 – An independent doctors' group in Zimbabwe is reporting 800 cases of the bacterial disease typhoid in a recent outbreak.
See also:No deaths have been reported in the past three weeks. The Zimbabwe Association of Doctors for Human Rights said Sunday that the nation's troubled coalition government lacked urgency in dealing with public health woes.
In a statement, the group said that amid heavy rains clean water supplies were still irregular or "completely absent" in most impoverished townships in Harare. It said burst sewers were left unattended and meat and fish were sold on streets nearby.
A cholera outbreak in 2009 blamed on the collapse of water, sanitation and prevention services in Zimbabwe killed more than 4,000 people.
World-travelling superbugs worry scientists
Sunday, Jan. 29, 2012 - Superbugs in Antarctica
“The discovery of bacteria that are massively resistant to antibiotics won’t make the front page these days – but when it happens in Antarctica, it is time to sit up and take notice,” says an editorial in the New Scientist. “The superbugs aren’t infecting penguins – yet – or even troubling the researchers who carried them there in their intestines and unwittingly deposited them in the sea via their sewage outfalls. But the discovery is further evidence that antibiotic resistance is no longer just a medical problem – it is an environmental one, too. And that makes fighting it much harder.”
Given that malaria was wiped out in the USA before DDT was invented, that seems to conclusively prove DDT isn't needed. What did eliminate malaria was those socialist public health programs. Alas, there is a certain type of person who hates things that work, purely for ideological reasons.What do you think would happen is dengue, malaria, and the other mosquito-borne fevers suddenly appeared in the U.S. and Europe? Can you spell DDT?
Push to eradicate tropical diseases...
A Call to Wipe Out Neglected Tropical Diseases
January 31, 2012 - A global initiative to control or eradicate 10 neglected tropical diseases within the decade was officially launched this week in London. Experts say the initiative is the largest coordinated effort ever undertaken to combat diseases - including sleeping sickness and guinea worm - that affect more than a billion people around the world. Tropical disease experts shared their thoughts with VOA about what impact the initiative is likely to have.
In an unprecedented show of unity, leaders of government, public and private health groups and major drug companies have pledged to work closely to combat neglected tropical diseases, or NTDs. These debilitating infections affect 1.4 billion people in the world’s poorest countries. The so-called London Declaration calls for the eradication and elimination of 10 of these tropical illnesses by the year 2020. The World Health Organization says NTDs cost billions of dollars in lost productivity. But the maladies have been largely overlooked by medical researchers because they affect relatively small and mostly poor populations.
Dr. Margaret Chan, WHO Director General, called the initiative a roadmap for an ambitious but achievable journey. “Just think of the prospect of freeing millions of people - most of them are children and women - so that they could have a healthy and productive life. On that we need your support. Come with us. This is going to be a long journey but we have [taken] a very good first step,” said Chan. With funds from various partners totaling $785 million, the project aims to eliminate many ancient scourges - such as leprosy, sleeping sickness, lymphatic filariasis, blinding trachoma, and guinea worm.
Microsoft chairman and philanthropist Bill Gates pledged $363 million through his namesake foundation. He called the London Declaration 'a milestone event.' “We have very ambitious goals that we have set. For example, for guinea worm we have got that 2015 eradication so we have a nice little competition going on between polio and guinea worm to see which would get to be the second disease eradicated and which will get to be the third disease eradicated, and the sooner the better for both of those,” said Gates. To speed the search for new drugs to fight the diseases, 13 drug companies have for the first time agreed to share their libraries of experimental compounds. And they also have agreed to donate and deliver billions of doses of drugs every year to aid the poorest of the poor, in the most remote corners of the world.
Dr. Mwele Malacela is director-general of Tanzania’s National Institute of Medical Research in Dar es Salaam. She said people in her country have been suffering because drug delivery always has been a challenge, but the London pledges give her hope. “Even when we have the donations, funding the delivery of the drugs has been a major problem. Now that we hear that there is more funding in the delivery side, we feel that we will be in a better position,” said Malacela.
There have been many initiatives against NTDs, although on a small scale. Dr. Neeraj Mistry, Managing Director of Global Network for Neglected Tropical Diseases, said they were not very effective because access to drugs was limited. “It's only now that with raised awareness and increased commitments from drug companies, as well as foundations like the Bill and Melinda Gates Foundation, and the US and UK government, that we can actually take the response to NTDs to scale - which means that we can treat more communities and more people,” said Mistry. Experts hope that by decade's end, the focus this initiative brings to neglected tropical diseases will mean they will no longer have to be called “neglected.”
Usin' bugs to kill bugs...
Bacteria used to fight sleeping sickness
14 February 2012 - The sleeping sickness parasite gets into the bloodstream
Scientists believe they have found a way to beat sleeping sickness using a bacterium against the tsetse fly host that spreads the disease to humans. In the same way that we have friendly bacteria in our intestines, the tsetse fly harbours bacteria in its midgut, muscle and salivary glands. Experts in Belgium have genetically modified these "good bugs" so they attack the culprit parasite carried by the fly. But work is needed to hone the process. The latest findings are published in the open access journal Microbial Cell Factories.
Sleeping sickness, or human African trypanosomiasis, is a potentially fatal disease that plagues many regions of Africa. Although the number of people being infected with the disease has been going down thanks to better diagnosis and treatment, there were still more than 7,000 new cases recorded in 2010. The parasite causing sleeping sickness is transmitted to humans through the bite of the infected tsetse fly. This causes fever, headaches, aching joints and itching. Then follows the second stage of disease as the parasites cross the blood-brain barrier to infect the central nervous system. The person then becomes confused, poorly co-ordinated and experiences the sleep disturbances which give the disease its name. Without treatment, sleeping sickness is fatal. But current therapies often have unpleasant side-effects.
The drug most commonly used to treat the condition is a derivative of arsenic developed more than 50 years ago. And the treatment can be excruciatingly painful and potentially fatal. Often described by patients as "fire in the veins," between 5% and 20% of those treated die of complications from the injected drug. And so scientists are seeking alternatives. The Belgium team at the Institute of Tropical Medicine in Antwerp have focused on finding a way to destroy the sleeping sickness parasite - trypanosome - that the tsetse fly carries.
They found bacteria called Sodalis glossinidius, which naturally live in the fly and can be used to mount an attack from the inside. Altering the genes of the bacteria led it to release fragments of antibodies known as nanobodies against the parasite. With more work, the researchers hope to be able to produce targeted nanobodies which could kill or block the development of trypanosome. Dr David Horn of the London School of Hygiene and Tropical Medicine said: "This is a neat and promising concept. The goal now will be to develop a deliverable toxin, not necessarily a nanobody, which exhibits anti-trypanosomal activity in the fly."
Tis an ill wind dat blows...
Wind Offers Clue to Curbing Malaria
February 14, 2012 - Study: targeting larval pools downwind from malaria hotspots could help control disease
A new malaria prevention strategy might literally be blowing in the wind. A team of scientists studying the patterns of malaria infection in rural Kenyan villages noticed that, despite a gradual reduction of malaria cases in the region, “hotspots” persisted. The blood-sucking mosquitos that transmit the malaria parasite to humans breed in water. So the researchers decided to examine the location of those breeding ponds in relation to the most infected villages. Their findings are published this week in Nature Communications.
Co-author David Smith, an epidemiologist with the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland, says a curious pattern emerged. “In this study what we did is we looked at the locations of aquatic habitats and the locations of humans and we were trying to find out if there was some kind of clustering, which there should be and of course there was. But as we looked even closer what we found was that there was an association between the direction of the wind and the location of where people were at risk.”
Smith says while mosquitos aren’t particularly good flyers, their flight pattern is directed by the scent of a potential human host. “We had a hypothesis that since scents travel down wind, that the mosquitos were actually tacking across the wind until they found one of those odor plumes and then tacking upwind until they found it. We should expect to find that places with higher risk were upwind of larval habitat.” Smith and his research team studied 642 children living in Kenyan villages after the rainy season, when malaria peaks.
Janet Midega is a medical entomologist with the Kenya Medical Research Institute and co-author of the study. She says scientists compared the malaria case data with the proximity of stagnant water pools. “What we did find was a lot of the pools of water did have immature mosquito stages, and so we sampled these pools of water. We sampled these mosquitos and identified them as the mosquito species that is responsible for malaria transmission in the area.” The study found that the shorter the distance from those larval incubators, the higher the prevalence of malaria.
A way to make malaria drugs cheaper...
New malaria method could boost drug production
Thu Feb 16,`12 – German scientists have developed a new way to make a key malaria drug that they say could easily quadruple production and drop the price significantly, increasing the availability of treatment for a disease that kills hundreds of thousands every year.
Chemists at the Max Planck Institute take the waste product from the creation of the drug artemisinin — artemisinic acid — and convert it into the drug itself. The entire apparatus is compact, about the size of a carry-on suitcase, and inexpensive. That means it can be easily added to production sites anywhere around the world. "Four hundred of these would be enough to make a world supply of artemisinin," said unit director Peter Seeberger, pointing to the machine on a table in his lab in Berlin's Dahlem neighborhood. "The beauty of these things is they're very small and very mobile." A paper on the new technique was published this month in chemistry journal Angewandte Chemie.
Artemisinin is extracted from sweet wormwood, a plant that primarily grows in China and Vietnam and varies in its availability according to the season. In the extraction process, for every part artemisinin produced, there is 10 times the amount of artemisinic acid discarded as waste. Past attempts to convert the acid using ultraviolet light to trigger the conversion have been unsuccessful because the process took several steps in a large tank of acid, making production inefficient and far too expensive.
So the Max Planck chemists thought small — creating a machine that pumps all of the required ingredients through a thin tube wrapped around a UV lamp in a continuous process that takes 4 1/2 minutes from start-to-finish to produce the artemisinin. The technique can convert about 40 percent of the waste acid into artemisinin — producing four times more of the drug from what had in the past been discarded, Seeberger said.
Colin Sutherland, a malaria expert at the London School of Hygiene and Tropical Medicine who was not involved in the Max Planck research, said the development could be significant in boosting production of the key malaria drug. He noted that currently very little artemisinin can be made from a large amount of the sweet wormwood, which is also difficult to grow. "If it's a simple process, given a certain amount of plant material, you can generate more drugs, that will make things cheaper and faster," he said.