dengue on the cellular level

Okay, Kristen wrote on her blog a really interesting quote that may help me understand the disease a lot better.

"Dengue virus infections are a major cause of morbidity and mortality in tropical and subtropical areas of the world. The immunopathological mechanisms that result in severe complications of dengue virus infection, i.e. dengue hemorrhagic fever (DHF), are important to determine. Primary dengue virus infections induce serotype-specific and serotype-cross-reactive, CD4+ and CD8+ memory cytotoxic T lymphocytes (CTL). In secondary infections with a virus of a different serotype from that which caused primary infections, the presence of cross-reactive non-neutralizing antibodies results in an increased number of infected monocytes by dengue virus--antibody complexes. This in turn results in marked activation of serotype cross-reactive CD4+ and CD8+ memory CTL. We hypothesize that the rapid release of cytokines and chemical mediators caused by T cell activation and by CTL-mediated lysis of dengue virus-infected monocytes triggers the plasma leakage and hemorrhage that occurs in DHF."

serotype - A group of closely related microorganisms distinguished by a characteristic set of antigens.
cytotoxic- a substance that has a toxic effect on certain cells
lymphocytes - Any of the nearly colorless cells found in the blood, lymph, and lymphoid tissues, constituting approximately 25 percent of white blood cells and including B cells, which function in humoral (pertaining to, or proceeding from a fluid of the body) immunity, and T cells, which function in cellular immunity.
antibodies- (just to make sure) Any of numerous Y-shaped protein molecules produced by B cells as a primary immune defense, each molecule and its clones having a unique binding site that can combine with the complementary site of a foreign antigen, as on a virus or bacterium, thereby disabling the antigen and signaling other immune defenses. (I think it basically means that antibodies can match the virus when it attacks the body. Meaning, the antigens knows what the virus needs in order to be broken down and calls for specific defenses from the immune system.)
monocytes - A large, circulating, phagocytic white blood cell, having a single well-defined nucleus and very fine granulation in the cytoplasm. Monocytes constitute from 3 to 8 percent of the white blood cells in humans.
cytokines -Any of several regulatory proteins, such as the interleukins and lymphokines, that are released by cells of the immune system and act as intercellular mediators in the generation of an immune response.
lysis - The gradual subsiding of the symptoms of an acute disease
plasma - the liquid part of blood or lymph, as distinguished from the suspended elements.

I still don't know what it means to have serotype-specific and serotype-cross reactive memory cytotoxic T lymphocytes.

Okay, this is my translation... I may be incorrect:

Where it says, "In secondary infections with a virus of a different serotype..." I believe that it is saying: when a person gets a more serious version of a disease, they get the same virus, except the virus is made up of a different group of organisms containing its own antibodies. The presence of cross-reactive non-neutralizing antibodies from the second virus intensifies the condition already, since it does not "neutralize" the fight between the disease and the previous antibodies, but instead it mingles in the fight and pushes it on. The bleeding in the hemorrhagic fever is triggered from the rapid release of cytokines (it says they are kinds of mediators when it comes to an attack) and chemical mediators causedby T cell activation and by CTL-mediated lysis of dengue infected monocytes. I think it means: since there is an outpour of mediators passing through the cells, it triggers plasma (the liquid part of the blood) leakage and hemorrhage - thats what causes internal bleeding.

Well, if my translation is any good, it has definitely helped me understand the disease even better.

BTW! Thanks Kristen!!!

What we have finished

As many have seen, Kristen, Krissy and I have finished constructing the hand and the mosquito model for dengue fever. We are in the process of finishing painting and constructing the platform where the hand and the mosquito will be mounted onto.

We had trouble finding the dimensions of the platform, but Janel helped us figure it out. Since it will look a bit like a pyramid, it made it difficult for us to find measurements for the slanting sides. Hopefully we will finish the platform as soon as possible.

The next steps of the project will consist of finishing the platform, then mounting the models onto it and then mounting everything onto our shelf and bolting it into the wall.

Chemistry Homework for Monday

just to help me research on codeine...

1. In writing, explain what this drug is used to treat ( e.g. specific simptoms, what it breaks down) 2.Explain when the drug was develped/ how it was discovered/what company or companies produce it/ how expensive it was to develop/the cost to manufacture/ and how much it costs in the region you are focusing on. 3.List and explain the side effects of the drug 4.Discuss other ways your disease can be treated

http://www.assistpainrelief.com/info/codeine/ - how codeine works

"Codeine is a weak opiate agonist that provides relief from pain by blocking the pain signals that are being sent from the brain to affected areas of the body. Within half an hour it works on the Central Nervous System (CNS) to inhibit these pain signals. Because the transmission of the pain signals has been impaired, less pain is felt, even if the original source of the pain remains. In this regard, codeine mimics the effects of endorphins, which are naturally occurring painkilling chemicals produced by the body." - I don't think translation is really needed.

As I already said before, dengue fever causes severe headaches, retro-orbital (behind the eye) pain, and severe joint and muscle pain. Although the disease doesn't have a vaccination or a drug treatment, at least it has medicine to reduce the agony of it.

http://opioids.com/jh/index.html - when codeine was developed

Apparently, codeine is an alkaloid of opium, which means that it basically has the same chemical properties. It was made in 1832 as a pain killer. They are all used to reduce pain without going unconscious.

Well, just in case I can't find a specific explanation on codeine, I will branch it off of opium. Opium has been around over thousands of years and has been used by Greeks as well as China and Southeast Asia. It was proven useful, especially for the Chinese who had given doses to their patients before going through major surgery.

http://www.assistpainrelief.com/info/codeine/ - who discovered codeine

"The French Chemist Pierre-Jean Robiquet was the first person to extract codeine from opium in 1832, hence the use of the collective terms "opiates" or "opioids" to describe these narcotics."

http://www.drugs.com/codeine.html - side effects of codeine

"What are the possible side effects of codeine?
If you experience any of the following serious side effects, stop taking codeine and seek emergency medical attention:
·an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);
·slow, weak breathing;
·seizures;
·cold, clammy skin;
·severe weakness or dizziness; or
·unconsciousness.
Other, less serious side effects may be more likely to occur. Continue to take codeine and talk to your doctor if you experience
·constipation;
·dry mouth, nausea, vomiting, or decreased appetite;
·dizziness, tiredness, or lightheadedness;
·muscle twitches;
·sweating;
·itching;
·decreased urination; or
·decreased sex drive.
Codeine is habit forming. Do not stop taking it suddenly.
Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome."

sites to annotate

I am still trying to figure out how the disease attacks the body at a molecular level.

for similarities between dengue and yellow fever:
http://www.traveldoctor.co.uk/yellowfever.htm

more on dengue
http://www.cdc.gov/ncidod/EID/vol11no05/05-0195.htm


Having every other site telling me about the symptoms of dengue fever is becoming a bit problematic, since they don't explain the specifics.

I want to be able to find the answers to these:

• Which organs does it affect the most and how
• why and how do rashes form?
• permanent damage it could do to the body
• How does the disease spread when the mosquito bites?

There will definitely be more questions later.

For Kristen Colley - studying drugs

Kristen is studying the drugs used for dengue fever, and in my last post there is an interesting website that suggests homeopathic treatments for the disease.

it's: http://www.delhihomeo.com/php/treatment/dengue_pre.htm

For simple dengue fever, it suggests taking a medicine called Eupatorium perfoliatum 200. It is to be "taken twice daily for three days and subsequently 2 doses a week in intervals of three."

For hemorrhagic dengue, it suggests taking ipecac in 200 potency.

I am not sure about the details as to the availability of these medicines to the people of South America since this site was made in Dehli. I may look into these later.

Avoiding Dengue Fever

http://www.dhpe.org/infect/dengue.html
http://www.wrongdiagnosis.com/d/dengue_fever/prevent.htm
http://www.delhihomeo.com/php/treatment/dengue_pre.htm - more reliable

From most of the sources I have found, they have suggested similar ways of preventing dengue fever.

First off, it is best to avoid mosquito-infested places such as tropical areas.
But yet, that does not assist those who live in those specific areas.

More imporantly for those who do live in those places should make sure:

• that the environment is clean
• water and containers should be covered
• mosquito nets should be used
• eliminate mosquito breeding sites

let me emphasize on water...mosquitoes can hardly exist without it.

Conditions where Dengue thrives

http://findarticles.com/p/articles/mi_m3225/is_n3_v45/ai_12026528

In this site I found, it says that dengue can be transmitted to person to person through the bite of a certain "host mosquito" called a female Aides aegypti mosquito. This mosquito apparently also plays a big part in yellow fever.

The places that these mosquitoes breed in include: "artificial water entrapment receptacles and is found in highest density near private homes. Discarded tires are a favorite site, as well as water storage receptacles, cans and open bottles." - I can conclude that people living in places that are well-littered with trash have greater chances of getting dengue fever.

The site goes on to say:

"The eggs are hardy and can resist drying for several months. The mosquito has a short flight range, and in urban areas, dengue frequently spreads from house to house in a contiguous manner, sometimes along one side of a street.(5) A. aegypti is widely disseminated in the United States (Figure 1), and consequently the potential for wider indigenous transmission exists. The transmission cycle begins when a female mosquito bites an infected host during the four- to five-day period of viremia, which occurs just before the onset of symptoms.(9)"

The latter part of this paragraph says that the A. aegypti, which is the mosquito that carry the disease, has multiplied in the States and there is a potential that more people will be affected by the disease. It may become an epidemic that had never seemed to reach our country.

.... And the last sentence basically says that an infected person will only discover that he or she has dengue fever within four or five days after they have been bitten by the mosquito.



Centers for Disease Control and Prevention
http://www2.ncid.cdc.gov/travel/yb/utils/ybGet.asp?section=dis&obj=dengue.htm

Most of the countries with dengue fever are tropical, where the weather is really humid and many rain forests are thriving. This is the problem for the poorer tropical countries where mosquitoes are thriving and cleanliness is an issue.

I am still not quite sure how dengue fever attacks the body on the molecular level. I will try to get some information on that soon.