Current Status Of Malaria Vaccinology Essays - Malaria, Apicomplexa

Current Status of Malaria Vaccinology In order to assess the current status of malaria vaccinology one must first take an overview of the whole of the whole disease. One must understand the disease and its enormity on a global basis. Malaria is a protozoan disease of which over 150 million cases are reported per annum. In tropical Africa alone more than 1 million children under the age of fourteen die each year from Malaria. From these figures it is easy to see that eradication of this disease is of the utmost importance. The disease is caused by one of four species of Plasmodium These four are P. falciparium, P .malariae, P .vivax and P .ovale. Malaria does not only effect humans, but can also infect a variety of hosts ranging from reptiles to monkeys. It is therefore necessary to look at all the aspects in order to assess the possibility of a vaccine. The disease has a long and complex life cycle which creates problems for immunologists. The vector for Malaria is the Anophels Mosquito in which the life cycle of Malaria both begins and ends. The parasitic protozoan enters the bloodstream via the bite of an infected female mosquito. During her feeding she transmits a small amount of anticoagulant and haploid sporozoites along with saliva. The sporozoites head directly for the hepatic cells of the liver where they multiply by asexual fission to produce merozoites. These merozoites can now travel one of two paths. They can go to infect more hepatic liver cells or they can attach to and penetrate erytherocytes. When inside the erythrocytes the plasmodium enlarges into uninucleated cells called trophozites The nucleus of this newly formed cell then divides asexually to produce a schizont, which has 6-24 nuclei. Now the multinucleated schizont then divides to produce mononucleated merozoites . Eventually the erythrocytes reaches lysis and as result the merozoites enter the bloodstream and infect more erythrocytes. This cycle repeats itself every 48-72 hours (depending on the species of plasmodium involved in the original infection) The sudden release of merozoites toxins and erythrocytes debris is what causes the fever and chills associated with Malaria. Of course the disease must be able to transmit itself for survival. This is done at the erythrocytic stage of the life cycle. Occasionally merozoites differentiate into macrogametocytes and microgametocytes. This process does not cause lysis and there fore the erythrocyte remains stable and when the infected host is bitten by a mosquito the gametocytes can enter its digestive system where they mature in to sporozoites, thus the life cycle of the plasmodium is begun again waiting to infect its next host. At present people infected with Malaria are treated with drugs such as Chloroquine, Amodiaquine or Mefloquine. These drugs are effectiv e ateradicating the exoethrocytic stages but resistance to them is becoming increasing common. Therefore a vaccine looks like the only viable option. The wiping out of the vector i.e. Anophels mosquito would also prove as an effective way of stopping disease transmission but the mosquito are also becoming resistant to insecticides and so again we must look to a vaccine as a solution Having read certain attempts at creating a malaria vaccine several points become clear. The first is that is the theory of Malaria vaccinology a viable concept? I found the answer to this in an article published in Nature from July 1994 by Christopher Dye and Geoffrey Targett. They used the MMR (Measles Mumps and Rubella) vaccine as an example to which they could compare a possible Malaria vaccine Their article said that "simple epidemiological theory states that the critical fraction (p) of all people to be immunised with a combined vaccine (MMR) to ensure eradication of all three pathogens is determined by the infection that spreads most quickly through the population; that is by the age of one with the largest basic case reproduction number Ro. If a vaccine can be made against the strain with the highest Ro it could provide immunity to all malaria plasmodium " Another problem faced by immunologists is the difficulty in identifying the exact antigens which are targeted by a protective immune response. Isolating the specific antigen is impeded by the fact that

Free Essays on The Force Of Lady Macbeth

In the play â€Å"Macbeth† by William Shakespeare, Macbeth is driven into a murderous rampage so that he may become king. In doing so, he must first off kill the King Duncan himself and everyone that is heir to the throne. Lady Macbeth, his wife, is suggested to be the mastermind behind the whole ordeal. She has a great deal of power over Macbeth and could have easily been the reason why Macbeth did embark upon his murdering spree. Macbeth had the ability to murder the king, although he had his doubt. He just had his wife’s encouragement to push him the rest of the way. At the beginning of the play, Macbeth does indeed have the ambition to kill King Duncan. Even Lady Macbeth knows he could, but she also knows that he wouldn’t without a bit of encouragement. She says, â€Å"The illness should attend it: what thou woulds’t highly.† So, in a way, Lady Macbeth somewhat brainwashes her husband into killing the king by subtly taunting his masculinity, like when she says, â€Å"what beast was’t then, That made you break this enterprise to me? When you durst do it, then you were a man, And, to be more that what you were, you would Be so much more a man.† Lady Macbeth would have even killed King Duncan herself, except she claims that he looked like her father. Lady Macbeth states, â€Å"Had he not resembled My father as he slept, I had don’t.† Even so, Macbeth went along with the plan and murdered Duncan. After his first murder, King Duncan, Macbeth becomes very ashamed of what he has done, â€Å"to know my deed, ‘twere best not to know myself.† Lady Macbeth doesn’t even seem to care in the slightest, but she is aware that if they think about what they have done too much, it will drive them mad. â€Å"These deeds must not be thought After these ways: so, it will make us mad,† she says. So instead she thinks that if they just get rid of all the evidence, then they will both be fine and no one will find out. â€Å"A little water clears us o... Free Essays on The Force Of Lady Macbeth Free Essays on The Force Of Lady Macbeth In the play â€Å"Macbeth† by William Shakespeare, Macbeth is driven into a murderous rampage so that he may become king. In doing so, he must first off kill the King Duncan himself and everyone that is heir to the throne. Lady Macbeth, his wife, is suggested to be the mastermind behind the whole ordeal. She has a great deal of power over Macbeth and could have easily been the reason why Macbeth did embark upon his murdering spree. Macbeth had the ability to murder the king, although he had his doubt. He just had his wife’s encouragement to push him the rest of the way. At the beginning of the play, Macbeth does indeed have the ambition to kill King Duncan. Even Lady Macbeth knows he could, but she also knows that he wouldn’t without a bit of encouragement. She says, â€Å"The illness should attend it: what thou woulds’t highly.† So, in a way, Lady Macbeth somewhat brainwashes her husband into killing the king by subtly taunting his masculinity, like when she says, â€Å"what beast was’t then, That made you break this enterprise to me? When you durst do it, then you were a man, And, to be more that what you were, you would Be so much more a man.† Lady Macbeth would have even killed King Duncan herself, except she claims that he looked like her father. Lady Macbeth states, â€Å"Had he not resembled My father as he slept, I had don’t.† Even so, Macbeth went along with the plan and murdered Duncan. After his first murder, King Duncan, Macbeth becomes very ashamed of what he has done, â€Å"to know my deed, ‘twere best not to know myself.† Lady Macbeth doesn’t even seem to care in the slightest, but she is aware that if they think about what they have done too much, it will drive them mad. â€Å"These deeds must not be thought After these ways: so, it will make us mad,† she says. So instead she thinks that if they just get rid of all the evidence, then they will both be fine and no one will find out. â€Å"A little water clears us o...

Homeward Bound Essay Example | Topics and Well Written Essays - 500 words

Homeward Bound - Essay Example I decided to run away from home this morning and I did. It was a reckless move on my part and thoroughly stupid. I understand that now if only in retrospect. I bet you want to know why I ran away from home. Well there could be any number of reasons right I could have a sexually abusive stepfather, or perhaps my mother is like that crazy, compulsive character on Desperate Housewives, or maybe I have lousy grades, an eating disorder and a drug problem, I could be on the run from the police (You can really use your imagination here). But the truth is none of these things or perhaps it is all of these things. I'll let you decide. You see, none of it matters. What matters is Leah and what I think happened to her. But I am getting ahead of myself. I was trying to put as much distance as possible between myself and my hopeless, miserable life. I had the compartment to myself, but it would not have mattered if it had been packed to the seams. There was no place for anyone else, wrapped as I was in my own private cocoon of misery. Suddenly, I felt rather than saw her her name was Leah. She was exquisite, like a porcelain figurine.