Sunday, March 9, 2014

Molecules versus Malaria

Molecules versus Malaria
 
Malaria is one of the most fatal and widespread diseases that affect a large amount of people annually due to the accumulation of the disease from the anopheles mosquito. Whenever the female mosquito requires a meal of blood in order to lay her eggs, the disease is transmitted into the bloodstream. Every year, there are three-hundred to five-hundred cases of malaria with two-three million resulting deaths, mainly in certain regions in Africa. The symptoms of malaria include jaundice, lethargy, fever, chills, coma, headache, muscle pains, and confusion. During the twentieth century, many people attempted to control the spread of malaria and provide protection against the disease. In the Andes, near Bolivia and Columbia, there is a species of plants of the Cinchona genus that contain an alkaloid, quinine. Quinine is a natural antidote that cures the disease of malaria. The quina bark has been consumed in the New World to cure the symptoms of malaria, along with cancer, hair loss, indigestion, and fever. In 1735, a French botanist, Joseph de Jussieu noticed another species of plants of the Rubiaceae family, yet the quina tree has been used and cut down in order to generate profit. Like another other molecule discussed in this book, the trade and monopoly of certain substances and compounds generate huge profits, which lead to the clear-cutting of approximately 25,000 quina trees every year, which depleted the natural supply of the quinine molecule. In 1820, the researchers Joseph Pelletier and Joseph Caventou managed to isolate and extract quinine, while it has been assumed that two molecules of allytoluidine reacting with three molecules of oxygen would yield to quinine and water, while the chemical reaction has been invalid; the yield of the combination of the reagents do not yield to the production of a quinine molecule; that is why Perkin failed to synthesize quinine, but synthesized mauve for the dye industry. Synthetic quinine could not have been derived at that time, therefore quina trees were being cut down to isolate the molecule from the Amazon basin. Large profit margins and economic expansion were noticed in many countries such as Bolivia, Deutschland, Columbia, Ecuador, and Peru from the monopoly of the quinine trade. Quinine is a derivative of the molecule quinoline; during World War II chloroquine has been synthesized from quinine after different methods of isolating quinoline from the quina tree have been discovered. Chlorquine contains a chlorine atom and acts as an effective anti-malarial agent and successfully treats acute malaria. During 1944, Robert Woodland and William Doering have synthesized quinine from quinoline and the synthesis of an identical to chemical/molecular structure of quinine requires a preparation of a mixture of two similar molecules present in the quina tree; the separation of the two similar anti-malarial would be very time-consuming and a difficult process to accomplish. The cultivation of quina trees, along with the harvesting of quinine still occurs in Indonesia, Zaire, India, and certain other counties. Alphonse Laveran and Ronald Ross discovered that the Plasmodium parasite undergoes a life cycle in the human body whenever a female mosquito bites an infected human. The sporozoites develop in the liver and produce spores in the bloodstream. This discovery lead to a new field of thought concerning the treatment of malaria and it has been proposed that preventing or breaking a certain section of the life cycle would prevent the disease from being spread. The molecule, DDT, or dichlorodiphenyltrichloroethane, is a potent insecticide that interferes with the nerve impulse transmission unique to insects and the World Health Organization initiated a campaign to manufacture and produce large amounts of DDT to cure and prevent malaria and to eliminate it. DDT has been applied in many parts of the world and significant percentages of eliminated malaria have been noticed and in 1975, the WHO declared that Europe is malaria-free. However, DDT is poses toxicity towards humans as well. There is a certain mutation in the hemoglobin molecule that provides immunity to malaria, which is common in areas such as Africa, and provides the disorder or sickle-celled anemia. Regular red blood cells or erythrocytes have a flexible, biconcave shape that pass through blood vessels and deliver oxygen to the specialized tissues and organs. However, the sickle-cells adapt a different shape and are more rigid and less flexible, which means that improper transportation and an inadequate supply of oxygen to the tissues and organs might lead to their damage and failure. Therefore, the sickle-cells are being constantly destroyed, which leads to a lower count of red blood cells, which accounts for symptoms of anemia. Carriers of sickle-cell traits live in malarial areas. In the beta strand of the hemoglobin polypeptide (which contains repeating units of amino acids), the sixth amino acid in sickle-celled trait carriers would be glutamic acid instead of valine; the problem with this missense mutation is that a mild alteration in the molecular structure of the hemoglobin molecule might lead to life-threatening conditions such as sickle-celled anemia. Since the amino acid, glutamic acid contains an attached –COOH (carboxyl) group, insolubility occurs inside the red blood cells and the precipitation accounts for the change in shape and a lack of flexibility of the erythrocyte. The author’s argument makes sense because the overall picture based on the effect of the molecules and anti-malarial agents, quinine and DDT, on the economy, settlement, changes in society, and the eradication of malaria in North America and Europe. During the 19th century, the quinine molecule facilitated the expansion of European colonies and the British Empire and during the 20th century, the molecule DDT has eradicated malaria in certain parts of the world and accounts for the safety of many people living in former malarial areas. Therefore, the effects of the two molecules quinine, which is derived from quinoline (extracted from the quina tree) and DDT, a synthetic organic compound that is a potent pesticide, on society and civilization is immense; malaria has been eradicated and controlled in many parts of the world, huge profits have been generated, and a significant economic growth has been induced by the monopoly of the quinine trade and the large-scale industrial production of DDT.                  


2 comments:

  1. Its interesting how DDT was so perfect for around 20 years or so and after so much accumulation it started showing its dark side.

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  2. In this chapter I think one of the most fascinating things was the fact that the carriers of the disease had some kind of immunity to malaria. And the possibility that evolution may be able to eventually create a certain human immunity to the disease is something very interesting and promising.

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