[-Monday, January 29, 2007-]

Filefront

Tink there's someting wrong with filefront.. How come both my frenster and this blog dun hab the backgrd music le!! Sian..
"Never ask why i love you, just accept that i do." || 9:21 PM

[--]

Tao Hua Yun

I beginning to feel that im having Tao Hua Yun again recently in online and offline life.. Actually, every year there will be a period when i got such streak. But too bad, most of time i cant handle it well.

Either we broke off, argued and lost in contact or some guy snatched her away before i decided to chase that girl. Ya.. i tink i not really good in such situations. Im beginning to wonder is having such luck with girls a good or bad thing for me.

This time i kinda confirm is bad for me. Rem the shanghai girl who i knew during a lab practical in year 2. Well.. i kinda like her as she is those i like. Cute, polite, looks kind and innocent, etc.. Now we are in the same module again. And we met in the lab practical again. I duno she is beside me until she talked to me. As blur as ever.. Im surprised that she still rem me. LoLx!! Anyway, i am more of guarding against her. Cos she's from China..

My mom told me that China girls like to blah blah blah.. I dun dare to say later all Chinaman come kick my ass and execute me!! Well, she said that her fren's son has a China gf (from NUS oso) and her son spent alot of $$ on the gf. Furthermore, the gf started to come to their house for dinner and later began to stay overnight in their house. As my mom's fren noe tat the girl has a hostel in NUS, she told her son to escort her back after eating dinner. And ta-da!! The son went to told his gf and they went out of the house without tellin the mother and without eating the dinner also. The mother waited like idiot for the couple to return for dinner but they never came back. This incident hor.. i duno the mother got exaggerate anot la. But is true, i tink the son really got big problem liao. Dunwan eat dinner oso mus tell the mother rite? Wah, angry den jus walked out of the house and let other ppl wait for u to come back den they can have their dinner?

From wad i noe, the son everyday gets $300 monthly allowance!! Wah!! If i am the mother, bye bye to that $300, dun even come and ask mi for the $300. Got gf big le rite? Okay, go ask from your gf for monthly allowance. Anyway, my mother told me (actualli she made it clear) that my gf cannot be from China. LoLx!! As if i will find a China gf =.=

Oops!! Wron!! Should b as if a China girl will like me xD
So now i met this girl from Shanghai again. She really very cute lo!! Y must she b from China!! Haiyo.. Anyway, she dun look like from China except her accent. Too bad la.. if she from Malaysia or wad, i sure jio her out de. Haha!! So i guess this is the end of my Tao Hua Yun for this year >< How much i hope that i can meet that girl from Human Physio lab las semester de. She is those cool cool and cute type. Wah.. i really cant stand cool girl. Will always tink of Hebe!! Haiz.. But this sem she's not in any same module as mi. So sad!!

Y this year, my Tao Hua Yun is so globalised de? Can give me some local girls de mah? I not such a "global" guy okay.. Japanese girl i dun mind =X

I wan either Noriko Sakai's daughter or Natsumi Abe. LoLx!!

ps: As for the China girl, not every girl is like that. There's bound to be a black sheep in every races. As simple as that.
"Never ask why i love you, just accept that i do." || 8:42 PM

[-Saturday, January 20, 2007-]

Wad is Cancer?

Wad is Cancer?

Cancers are tumour cells which are able to invade neighbouring cells and eventually metastasize (Terminal stage).

Tumours cells are cells which proliferate in an unappropriate manner which cannot be controlled. These tumour cells are undifferentiated. So they are of no use to the body. Normal cells will undergo differentiation to specific function cells such as nerve cells or muscle cells.

Tumours cells are common to everyone. Mutation occurs randomly and causes the mutated cells to start cell division unappropriately causing tumour cells. We may or may not be able to feel the tumours. However, most of the tumours are harmless. Nutrients, oxygen and waste products diffused from our blood stream to enable the survival of these tumours. If the tumour grows too big and the rate of diffusion is unable to facilitate such processes, the tumour cells will undergo Apoptosis aka Cell Death for the good of the rest of the cells.

However, if the tumour is able to conduct angiogenesis (growth of blood vessels on the tumour), the tumour will grow rapidly and to a larger size at a much faster rate. This is still not cancer.

The stage where it is known as the malignant tumour (cancer) is when they start to invade the neighbouring cells. This stage is mostly curable as a surgery is sufficient to remove the affected part. However, the terminal stage (metastasis) where the cancer cells start to break away and move to other parts of the body via our blood transport system. There will be no possibilty of cure.

So wad causes cancer?
Cancer are caused mostly by mutation and lifestyle and is a inheritable disease. Why?

Why cancer are caused by mutation?
Studies are performed by mutation of genetic DNA. 3 classes of DNA are especially closely connected to the cause of cancer.

1. DNA repair genes
2. Oncogenes
3. Tumour Suppressor genes

DNA repair genes are genes that expressed proteins that helped to repair DNA which are damaged due to mutations. If a DNA is damaged and the cells are unable to repair the genes, the cell with the damaged DNA will undergo programmed Cell Death (Apoptosis) to prevent further problems to the rest of the cells.

Oncogenes are genes that expressed growth signals for the cells to undergo cell division appropriately. 1 cell undergoes cell divide to give 2 daughter cells. Den these 2 cells will undergo cell division to give 4 daughter cells etc.. If an oncogene is mutated, it will cause the cells to undergo cell division unappropriately, giving rise to undifferentiated tumour cells.

Tumour Suppressor genes are genes that suppressed Tumour. If it is mutated, tumour cells will be allowed to grow.

Therefore, DNA repair genes are impt. If it is mutated, mutated Oncogene and T. Suppressor gene will not be repaired.. Thus, allowing tumour cells to proliferate.

Further studies had shown that mutation takes time to occur as several mutation of various T. Suppressor genes are required before they are rendered helpless in stopping formation of tumours. Therefore, lung disease due to smoking took 10-20 years to take effect. During these 10-20 years, mutation occured randomly within your body. With smoking, you are only hastening the rate of mutation together with Mr Probability.

Why cancer is an inheritable disease?
Studies had proven that this is indeed an inheritable disease.

1. When a DNA gene in a cell is mutated causing cancer cell. When the cancer cell divide, both 2 daughter cells consist the same DNA gene with the same affected region.

To put in simple words, they are the exact replica of the cancer cell. In a normal cell wen undergoing cell division, the 2 daughter cells are not exact replica of the parent cell. Some traits changes during mitosis. This does not apply to cancer cells however.

2. For woman germline cells which consist of XX chromosomes. 1 X chromosome will be inactivated as Barr Bodies. Which X chromosome to be inactivated is random for normal cells. However, for the cancer cell, if the paternal X chromosome is inactivated, the daughter cells of the cancer cell will also hab their paternal X chromosomes being inactivated.

Oncogenes
As mentioned earlier, Oncogenes are genes that promote expression of growth signals which signal the initaition of cell division in a controlled manner. However, if Oncogenes were to be mutated, it may signal cell division to occur inappropriately, that is cell division occurs repeatedly for the cells, forming tumour.

I will discuss on a Oncogene which is called the Ras. Ras and Myc are both linked to cancer.

Ras activates a cascade of pathways which involve Myc, PKB, E2F, p53. p53 is especially impt as it initiates Cell Death when activated. One reason why cancer is prevalent is bcos the pathway linking to cell death is obstructed, meaning p53 is being inactivated.

Ras
Ras leads to 2 pathways. 1 pathway leads to Cell Division or Cell Growth and Cell death as well via Myc and E2F. U may wonder how come it leads to both cell growth and cell death at the same time.

Rem this: What goes in must = What comes out. Life is in an equilibrium state. If this equilibrium is disrupted, trouble looms ahead.

1 pathway leads to inhibition of Cell Death via PKB.

Therefore, if Ras is mutated to be able to over expressed in our body. The signal to inhibition of Cell Death and initiation of Cell Growth both increased. Hence, tumour will be formed. Experimental studies of mice with mutated overexpressed Ras results in the mice having breast tumour.

Myc
Unlike Ras, Myc is activated by Ras and in turn only lead to the pathway which leads to Cell Growth and Cell Death. Therefore, if Myc is mutated to be overexpressed. The signal to Cell Growth and Cell Death increased hence no tumour is found in the mice with mutated Myc.

Ras + Myc Wad will happen?
If a mice with both mutated overexpression of Ras and Myc genes, tumour occured at a faster rate. As both Ras and Myc both signal to Cell Growth and furthermore, Ras signals the inhibition of Cell Death. Therefore, the tumour cells will only increase and not decrease.

This expt further proves that more than a single mutation is needed for cancer to occur.
"Never ask why i love you, just accept that i do." || 8:10 PM

[--]

Wad hab i learnt tis week?

I realised that my previous post is filled with "la", "wad", "wtf".. LoLx!! Read liao feel so weird.

Anyway, this week quite interesting. Get to learn more abt cancer and transgenic zebra fish.

Fri got biotech's practical where we got to inject promoter-specific DNA construct which will be able to make use of zebra fish's protein synthesis mechanism to produce Green/Red fluorescene protein. A typical commercialised fish on sale is called Glo-Fish.

We got to play with Skin-specific and muscle specfic promoter DNA which the fluorscene protein will be produced on the skin and muscle respectively.

First, we caught 2 fishes and put them into a tank of phenylethanol where they will be anaesthesized. They will turned upside down and stopped moving after 30-60 seconds. Next, we will take them out and inject 1 micro litre of DNA construct into the muscles below their fin. After that, we transferred them into a tank filled with antibiotics to prevent them suffering from inflammation from the injuries. Finally, the fishes are transferred to a clean fish tank of normal water. Each of us injected 5 fishes each.

After that, the teaching assistant (TA) proceeded to bring to observe the Glo-Fish on the other side. According to him, the Glo-Fish are stable trangenic line which means that the DNA construct which we had injected are present in their chromosomes and will stay with them through life. They will be able to produce the fluorescene for the whole lifespan and their babies will most likely able to inherit these traits as well. For the fishes we had injected, they will only be able to stay fluorescene for half a year as they are of a transcient expression. That is the DNA will be lost gradually overtime as the DNA are injected intramuscularly.

If we want the DNA to stuck with the animal, we hab to inject the DNA into the embryos of these fishes. This will increase the chance of allowing the fishes to retain these DNA within their genome. In order to inject into these small embryos, we hab to use micro injection which is the last part of the practical. However, the success rate of injecting, alllowing the embryos to survive till they become fishes and the fishes eventually have the DNA stuck with them are still comparably low. For those embryos which hab survived to become fishes, some will fluorscene while some will not. Those which are able to fluorscence, we mate them with the normal zebra fishes to give a F1 generation.

Those in F1 generation which possess this phenotype (traits of able to fluorscence, less than 5%), we called them to be the transgenic founder because they contained the DNA within them but we cannot be sure whether this traits will stay with them for life. For some which do not fluorscence, this does not mean that they do not possess the DNA within them, there is a small probability that they do possess the DNA however, they are called silent gene (unable to be expressed phenotypically but they are within the animal chromosomes genotypically).

Eg. For human. Guy germline DNA consists of XY whereas girl consists of XX. As girl's DNA consist of 2 same X and X. One of the X are being inactivated and knowned as the Barr Bodies. This is one of the reasons why there are alot of genetic dieseases which there's a high possiblity of woman suffering from. As only one of the X DNA is expressed in female to allow proper functioning of the cells, hence if the defective X DNA chromatid is transmitted from the mother or the father (most likely from the mother side who is the carrier of the genetic disease) to a girl. Her body will only b able to express this defective X DNA template for the functioning of cells if the other normal X DNA is being inactivated. The inactivation process is random and will change randomly during each cell division. Normally, this defective X DNA causes loss of function. For eg. The normal X DNA consists of gene which allow expression of proteins to form your immune system but this defective X DNA gene which codes for the same function is changed to a non-functional proteins. Therefore, your imune system is ruined. However, there are some gene being mutated that gives a gain of function gene. However, the proteins being expressed by such gene may be good or bad for you. It may boost your immune system compared to the normal gene or it may act as a poison to your body.

Back to the zebra fish, since there is such process where in case of a double XX chromosomes where 1 of the X will be inactivated. This X may be the chromosome that possess our fluorscence DNA but it was not able to be expressed as it was being inactivated. Therefore, in order to screen for such possibility, we uses RT-PCR (Reverse time Poly Chain Reaction) where the DNA are being amplified and analysed by SDSpage/ Electrophoresis/ELISA methods. If the DNA sequence of the DNA which we had injected earlier are found, this showed that this fish is also a trangenic founder.

So what's the difference between a transgenic founder and a stable transgenic line?
Transgenic founder is the F1 generation. Whereas a stble transgenic line is the F2 generation. F2 generation is when the transgenic founders are mated with the normal zebra fishes again. The % of the F2 generation having the fluorscence trait is 50% according to the Mendelian Rule. For the transgenic founder, theres a possibilty the DNA which we hab injected via their parents be lost. However, for the stable transgenic line, the DNA hab been integrated inside their own genome. Loss of the trangenic DNA is of low porbability.

What are the consequences of such transgenic fish if they were to be released into the wild?
Will they cause the wild type species of zebra fish to be extinct? Previously, theres 2 mathematicians who proposed that such Glo-Fish will be more popular to the female wild type zebra fishes since they FLUORSCENCE and APPEAL to US. No experimental studies were conducted to confirm this. Finally, experiment were conducted and the results were totally opposite of the 2 mathematicians.

First, Male zebra fishes that FLUORSCENCE DO NOT APPEAL to both the Female wild type and transgenic zebra fishes. They only appeal to us =="

Imagine Hulk and Superman come to you and want you to choose one of them. Of cos, you will choose Superman right? LoLx!! Okay, my analogy abit off. =.=

Second, transgenic zebra fishes lifespan is shorter.

Conclusion?? U figure that out urself.

Next, we went to do the micro injection. The needle is super fine.. I think poke into u u oso duno lo. So we use a microscope and proceed to aim the needle towards the embryos. The embryos like soccer ball lo. The first time i poked, i poked through it =.= Den u can see the embryos from round became deflated. Dots.. I killed 1 fish =X Den i tried again. This time succeeded. Woot!! Hope they will grow wen we come back on Monday. ^^
"Never ask why i love you, just accept that i do." || 6:59 PM

[-Thursday, January 18, 2007-]

Lots to say!!

First, Hong Kong ppl wtf are all of your problems?

Ppl wanna commit suicide, you all like to laugh and laugh, sneer and sneer and even encouraged them to jump down fast?

WTF is wron with all of u?? Work too much den all kana stressed till sot sot?

When that person decided not to jump u all laughed and booed at the ger and even commented that u all noe that she dared not to jump anyway. If she wanted to jump, she would have jump down long time ago. KNN!!

Den one day another guy decided to commit suicide oso by hanging at the window pane on the 9th floor. Same fking ting happen again!! Passers by stood and watched. Watched den tiam tiam la. Still dare to laugh and ask him to faster jump down.

And guessed what? That guy really damned stupid la (changed my mind), he really let off and jumped. He got killed on the 4th floor balcony. Now wen the reporter interviewed them, they tiam tiam dun dare to say anymore ting. Fk la!! U all so li hai know when ppl will dare to jump when they dun dare to jump. I bet u all dun even dare to walk up to 9th floor of the same building and hang on the window pane for 10mins!! Cos wad? U all will scare that the guy's spirit will come and make u drop down and die with him.

I cant really say that guy is really stupid. U noe wad? Sometime guy can be really stupid due to our ego.

Imagine la.. Since female activist are fighting that guy and ger should b equal, how come guy dun even dare report to police for being sexually harassed by a girl?

Y? Bcos of our ego la! What will a police of your same gender tink of u wen u told him that you are being sexually harassed by a girl? Sissy? Coward? Not a man?

This is the same as the 2 incidents occur above. Y didn't the girl jump whereas the guy went to jump? Bcos of the guy's ego. Maybe if that guy didn't jump, the ppl will say that the guy is tis wad wad wad... Throw guy face, go and b a ger etc..

Wad i am trying to say is gender stereotypes still do exist and will forever be there despite how much the activist are trying to call for equality between genders. The best ting is even the activists themselves practiced gender stereotypes without themselves realising that.

2nd ting is i was wondering... If u hate this guy alot. He got real bad fking attitude. Somemore even to gers even tou iin his own frenster profile, he put a guy should nv hit a girl, should not scold bad words etc.. LOL! And he likes this girl. The girl like kinda heck care him for duno how many donkey years. He even said that the girl sometime dun even talk to him if he pissed her off. (See wad he write i very shiok.. I so bad.. =X)

I was tinking.. No matter how great a guy are u (he's not great okay.. i jus using a bi yu), u will always be bring down by a girl. Somemore, i saw that girl's pic. I was like astonished.. This girl can make him behave like a mouse? This made me confirmed with my bi yu.

ps: I not saying that the girl is ugly or wad okay.. Is jus that she is not my kind thats y i feel nothing wen i saw that pic. Mayb to other guys with other taste, she is very appealing to them.
"Never ask why i love you, just accept that i do." || 6:29 PM