[-Tuesday, October 31, 2006-]

Bird Nest

Today im gonna talk abt bird nest ^^

Yup, i mean the one that chinese like to eat as tonic. Traditionally, bird nest is regarded as a very good tonic which is good for our lungs. That's why, parents of asthmatic children normally brew bird nest for them.

But, guess wad? According to immunology department of TTS hospital, most of the incidents that resulted in asthmatic attack is when the asthmatic childern took in bird nest. Duh!!

So our lecturer of Immunology actually conduct an experiment to find out what actually in the bird nest caused asthmatic. Asthmatic is caused by an antigen called allergen which gives rise to hypersensitivity. Hypersensitivity refers to specific antigen recognised by our antibodies giving rise to over-whelming response. Hence, asthmatic arose.

Hypersensitivity is also related to allergies to seafood and dustmites. Hypersensitivity is FATAL. The death rate is very high. Ironically, hypersensitivity occurs actually to help us get rid of the "foreign" bad stuffs in our body but in a wrong way. Give 1 example.

Normal Immune System
When bacteria invades into your body, our body's innate immune system (white blood cells such as monocytes, neutrophils, etc) is able to identity them and destroyed them, simultaneously activating the specialised immune system (T cells and B cells). They destroy the bacteria and release chemokines which cause vasodilation of our blood vessels thus resulting in redness and swollen and pain. This is a normal pathway of immunity.

Hypersensitivity
However, for hypersensitivity, it acted almost the same pathway except that the bacteria here is actually is seafood or dustmites or pollens which contained antigens that activate the immune system of our body. So same thing occurs except this time the vasodilation of our blood vessels is too serious resulting in a big drop of ur blood pressure. This big drop in blood pressure results in death for most. Next, chemokines also served to constrict/contract our respiratory pathway. Therefore, difficulties in breathing (asthma) occur and death occurs again. But as you can see, this pathway is actually the same pathway adopted by our immune system to protect our body from harmful bacteria. But in this case, it turns out to be killing us instead.

Do you know why is that our future generation is allergic to more and more weird bacteria? It is actually because that our city is too CLEAN!! Therefore, our body immune system is unable to upgrade itself against all the powerful bacteria and guess what our body's immune system upgrade themselves with? DUSTMITES!! One evidence is that the number of asthmatic cases in undeveloped and developing countries are insignificant compared to Singapore. A CLEAN and GREEN city indeed!!

Do u know that when you are having fever, this is actually a symptom that your immune system is battling against some bacteria or viruses? But wad happen wen u take in panadol? The pain is gone.. Meaning? You actually send in signals to your body's immune system asking the immune system to stop killing. =="

Here is a very funny personal experience from the professor. When he had his first child, the child got a fever and he straight away rushed back from NUS and bring his kid to a nearby clinic. The kid now has asthma. For his second child, once again this child had a fever and this time the prof actually waited until he had finished his work den he brought the second child to a clinic. Tat child had a slight asthma. His third child got a fever again. He don't really care this time, ironically his third child is so far the only child that had no asthma at all. Weird huh?

Bird nest experiment
okay, let's get back to the experiment. So the prof is trying to find out what actually caused asthma, his first hypothesis is that the bird nest must be added with some agar agar to make it heavier so that they can be sold at a higher price, therefore, the agar agar must contain some allergen that causes asthma attack or hypersensitivity. However, his result turned out to be otherwise. he actually collected the serum sample (contain antibodies) from the asthma children and react it with bird nest. He discovered that the antibodies from the children actually bind to the swallow's saliva. Therefore, the ultimate allergen is the saliva of the swallow. Bird nest is formed from the saliva of a swallow.

Conclusion of the experiment
It is the saliva of the swallow which actually react with the asthmatic children's immune system to bring about a hypersentitiviy response in the form of asthma due to constriction of their airway. So think again when your grandparents and parents told you that birdnest is good for your lung. It may not be harmful to you if you are not allergy to the saliva of the swallow but it is defnitely fatal to some asthmatic children.
"Never ask why i love you, just accept that i do." || 10:19 PM