Monday, April 23, 2012

The authority of teachers

Apple daily had a recent commentry written by Chip Tsao(陶傑). 

For those who can't read Chinese, it was about a secondary school teacher having problem with child who doesn't give a damn about the subject she was teaching - home economics. The child thought that if the button goes off from the cloth she'll just buy another piece of clothing[1]. Tsao believe that it is important for the teacher to hold up their dignity and perhaps traditional values in school and that she should not be afraid of complaints.

To be honest though this is totally NOT applicable for secondary teachers these days -- the principals in schools are more apologetic than ever and to be honest do they even have the dignity of an academic?

The value of his comment aside, this is a very vivid illustration of teachers losing their authority over students and parents.

I personally hold a belief that teachers should:

(1) Be very knowledgeable in their field, and
(2) Be respected.

The thing is, if you would like the teachers to deliver their teaching effectively, they have to be able to manage the classroom well - and to manage the classroom well, one has to confer them of adequate power to discipline the children in the class (fairly).

These days, the typical teacher had more fear than power inside the classroom. Children are more fragile than ever - they are prone to harm themselves, taking drugs, joining gangs and so on - if you ever punish them, and they retaliate by abandoning themselves. And then if they go such way after your punishment, you are going to be the "killer teacher" who will be fired and not be hired by any other school. And even if a child cries at home after being scold/punished in school, parents these days often complain to the school without even knowing why their child was punished.

If a teacher had more fear than power inside a classroom, how can they teach effectively?

Thus, the way to go is:

(1) For the management of school - you should stand by the very teachers you have hired, and treat students as students, parents as parents and school as a professional agent delivering teaching. If they run the school like a service industry, the only that can come is failing the delivery of teaching (and thus they fail professionally).
(2) For the teachers - they should uphold their professional standards and not be put into fear by these students and parents who would only complain.

In my humble opinion, though, teachers in Hong Kong had more problems with knowledge in their fields than complaints...

[1] well, true - and perhaps it even isn't economical to put it back in if the one doing it is earning quite a bit per hour

Friday, April 20, 2012

Tetris & Friends

Came across this piece recently. The technique may not be perfect but his interpretation of the tetris song (Korobeiniki) is excellent. For the original, see below:


Examinations for doctors

Examinations for the medical doctor (as in achieving a specialist status) are usually divided into two parts:

1. Membership examination
2. Fellowship examination (also called the "Exit" examination)

The membership examination is often itself comprised of several parts, with the first examination focusing on the basic sciences of medicine (e.g. Anatomy, Physiology, Biochemistry, etc.) - the so-called "part 1 examination". The remaining parts of the membership examination then focuses on patient management - usually those skills and knowledge that are required to run a department rather independently.

The fellowship examination are designed to examine candidates to see if they deserves the specialist status - advanced knowledge on the subject, latest development, and increasingly, management skills are examined, often in a face-to-face manner, known as the 'viva' examination.

Tuesday, April 17, 2012

Bride wannabes :: Florence

Warning: Spoilers ahead

She, in fact, is the most truthful women out of the five contestants.

Not that she is particularly pleasant or that her personality is particularly amiable, but she is speaking the truth, deep in her mind - and I guess this mind-set is sort-of engraved onto the mind of fellow female citizens of Hong Kong.

Your look matters, you age matters

She mentioned in episode three that Mei-ling has introduced to her an old man - CK Tsang in the show - who purportedly is a community college lecturer[1]. She obviously judged CK in his look and that his age is old - without thinking that she is already approaching 40. Looking at it on the another scale, she is only a few years approaching menopause, which, otherwise could be termed as "physiological infertility".

It is the nature of men to date young women. Though feminists may disagree on this, the nature of men to date young women is likely an evolution-derived characteristic.

The simple reason behind dating a young woman is for her fertility. Women ovulate every month, and often till the age of 50. It is very important to know that all the ova inside a woman's ovary are already made by the time that she was born, and these ova, unsurprisingly would be worse off when used 40 years after it was made, than, for example, some 20 years after it was made. This is demonstrated by the vast increase in genetic defects such as Down syndrome for women past the age of 35.

As to giving birth to a child, the answer is: 20 years old physiologically, 30 years old psychologically and 40 years old economically.

And then if you loved me, you should accept me "as-is"

Not that it is any wrong - but one has to get others to love him/her before one can say this. And as Mei-ling pointed out aptly, in terms of matchmaking, no matter how good you are, there ought to be somebody out there who are as good as you, yet prettier than you - and if you don't care about your outlook, you won't even get the chance in the first place.

Love is a bilateral business[2]. Anything bilateral involves compromises - that is, unsurprisingly, changes that one has to make in order to keep the relationship going. I am not a christian, but the biblical teaching on love is really on the point:
Love is patient and kind; love does not envy or boast; it is not arrogant or rude. It does not insist on its own way; it is not irritable or resentful; it does not rejoice at wrongdoing, but rejoices with the truth. Love bears all things, believes all things, hopes all things, endures all things[3].
There is probably no such somebody out there who do not need to change to behave as described above... Not me, after all[4].

More to come.

[1] And according to some facebook members who confirmed his teaching career
[2] Readers who can read chinese is directed to RC's blog here
[3] Emphasis mine.
[4] I love my girlfriend dearly, and not that I haven't changed. I think I changed for the better of our relationship.

Monday, April 16, 2012

First degree

Recently came across a few books in the commercial press on the topic of "what i wish i knew when i was 20".. Surely these books do have some content to sell and if a 20-year-old man would really follow the advice i can see it working...

I also have something to offer to the secondary school students (though i think none of them are likely audience of this blog). it's about one's own education.

what comprises a degree

depends on who you ask - this is going to mean very different things for different people. most would see a degree in terms of:

(1) the granting institution
(2) the faculty / major
(3) the honor (as in, first, second upper/lower and third)

for those who dig deeper, these are also interesting to the employer:

(4) whether it is acquired in distant learning (esp Lond degrees)
(5) supervisor for final year project
(6) courses taken

For the items 4-6 they would need your transcript to know it.

and getting a good first degree is important

the reason why a good first degree is important is that a second degree (or taught master for the matter) is never going to cover up the blemishes introduced by the first degree - unless the second one is really a spectacular one. studying for a second degree mean that you will need to dedicate time which you could spent to polish your career path. these also raises question in the job interviews on why you do not get into your target school in the first place (hint: this prompts the interviewer that you may be a lazy person)

what is a good first degree? it's simple:

(1) the best local schools - nobody is going to blame you for not going overseas
(2) oxbridge, icl, lse, st andrew, durham, ucl
(3) ivy league, pacific-12

for the purpose of hong kong students - (1) meant hku, cuhk and hkust. it is not that the other schools do not have good degrees[1] - it's that people look at the degree name, then the bracket, then the rest.

and then not that japan universities are not good - in fact, u of tokyo is very good in most aspects and are great rivals with hku in terms of ranking - note that hku's ranking is more of a research thing than a teaching thing and many of us would consider u of tokyo having better teaching and better students than hku.

why not a good second degree/master degree?

the simple reason is that it is less recognized - most boss understand what taught master meant - it's just exchanging money for degree - and often one do not learn much because of (1) its part-time basis, and (2) because of daytime work. if you do fulltime on these taught master then it raises question on how much your time is really worth - to be honest, to a productive man, a year off just for a master degree is way too much.

for the (overseas) research master, it may as well be better, but then the career choice would then be much more limited - mostly to companies with R&D, as well as in the academic/teaching field. it is also a more difficult business - professors detaining research students just to complete projects are not something that is unheard of.

[1] for example, polyu BA in design is of course best in the field, but we are talking about general degrees. general ones.

Mechanical watches

Watches, watches...

These days wearing a mechanical watch seems to be more of a lifestyle choice than a necessity – clocks are everywhere – the little clock sitting at the right-lower[1] corner of the screen is the ubiquitous example. To make the watches even more redundant – a clock which synchronizes to a network clock is almost always available at your pocket – your smartphone.

So yes – your watch is likely to be a mere ornamental instrument.

Why do people wear watches then?

In some professions, doctors included – recording the time of an incident is of extreme importance and good documentation can often spare one from a legal suit that may cost millions of dollars. A handy reference at your left hand, be it 5 minutes late or 4 minutes ahead, is still better than having to take the phone out from the pocket (often with a dirty hand).

In other professions, the watch is a symbol of wealth and sometimes a fashion statement. Granted, some watches are very good looking – just look at the latest Omega watches – they are definitely gorgeous (look at the Ladymatic line!) However, in my humble opinion, the beauty of old-school Swiss watches e.g. Patek Philippe and Vacheron Constantin are not really that easily appreciated, especially for those who do not have a great interest in it... Do the watches really look THAT good with the black leather strips? Wearing it is probably more for the brand than for the look (and movement) of the watch.

It is the mechanism that matters

Many of us men have an innate love to great engineering – and mechanical watch is exactly one of those things that belong to the 'wonderfully complex, yet incredibly small' category. If you own one of those watches that had a 'open-heart' configuration, or one of those with a transparent back – looking at the movement (the term for the mechanism of the watch) is quite an enjoyable thing.

In the beginning, most watches are hand-wound and the power derives from the tension build upon the mainspring. The mainspring provides the force necessary to drive the watch. The force is then used to drive a series of gears which moves the balance wheel – which is made to rotate in a simple harmonic motion – it oscillates to and fro at a constant rate.

The periodic movement of the balance wheel is then converted into stepwise, single-direction, rotatory movement by a structure called the escapement. This stepwise, single-direction, rotatory movement then drives a series of gears which eventually tells the time.

Below are a few video that is quite interesting and a good introduction to the working of mechanical movements:

What do I wear?

I wear a rather uninteresting mechanical watch with a power reserve indicator. The mechanical watch allows me to know the time easily, the mechanical nature pleases me because I know it is harvesting the otherwise wasted energy from the movement of my hand, and the power reserve indicator soothes my soul because it allows me to know the mechanical energy remaining in the mainspring (and thus I can have a good sleep without winding all these watches before I sleep in the fear of losing time)

[1] For those mac users, right-upper corner.

Sunday, April 15, 2012

What? Winnie Leung as a life coach? Coaching whom?

What is with choosing Miss Winnie Leung as a life coach? Is it that she is so successful in life that we would need her to coach other women who are unable to find a man who would stay with her for life?

Just examine the labels at her blog:

"bling bling, BMW, Chanel, Clinique, Facebook, Grand Hyatt, Hermes[1], HRT, il colpo, iphone, Kenji Ng, L'Oreal Paris, Lane Crawford, Louis Vuitton, LV, M.A.C. Porsche, Purpleland, Sassou Cosmo, Sex and the City, Tod's, TVB, Ultima II, Winnie Leung, Younger by Design, YSL" (There are another 19 Chinese tags) [2]

If these are representatives of what she is most interested in, I do have my reservation for her to be anybody's life coach...

Not that I am skeptical to the discipline of aesthetic medicine - but if she has nothing more than makeup, facials and aesthetic medicine to offer to her clients, one would really need to think if she is really some target goals that these five ladies in the show should really be after... (not that she's married, anyways... did I say the show is called "bride wannabes"?)

To some, the show means good entertainments for 10 weekdays.
To some, the show means an often undesired reminder for those who are still not in a relationship.

To some, the show means the day of judgement for ladies who are still not in a relationship by the age of 30.
To some, it is a joke.

[1] I really do not see the need to type the letter e with a grave accent - does that make it look nicer? Perhaps. To be honest, typing the letter with the accent is quite an undertaking for somebody with a keyboard manufactured in Hong Kong - but then who knows - maybe she got a Hermes branded keyboard...
[2] Taken from her blog on 15/4/2012 5:30

Saturday, April 14, 2012

Bride wannabes, and Supersize vs Superskinny II

The UK television program probably wins in terms of actually making people happier.

Getting the much needed love - for the lady

It is really not that difficult to get love - especially for the ladies, given the correct mentality. It is never the face or body shape that is precluding a woman from a successful relationship[1]. It might as well hinder a bit in terms of establishing a relationship in the beginning, but past the first few months, the face is not going to mean much.

The face ages, the body shape sags, but the mind evolves.

In Bride Wannabes, they are giving the ladies chances in changing themselves - mostly aesthetic, sometimes behavioral, but almost never mental - You see them having their hair dyed, face covered with makeups, eyelashes lengthened to exponential scales and different clothes to package them into nice-looking ladies. You also see courses given to them in terms of how to seduce people, and how to begin a relationship.

But then this is not the point - what they need is to change their mind[2]. The most important thing that they can learn is to extend their social circle. It is really not that hard - know the friends of your friends, and you are already exponentially enlarging your social circle.

Contrasting it with the UK program, in which the chief reason for their problem (eating habit) is being treated - which program is doing good for the ladies?
[1] The same is true for the gentleman. 
[2] There are quite some discussions on how these girls are paid actress, but anyways, it doesn't matter - what we're discussing on is the mindset / philosophy behind the show.

Friday, April 13, 2012

Bride wannabes, and Supersize vs Superskinny

For the uninitiated...

Miss Winnie Leung is an avid blogger, and author of various books including 男人争氣手冊, 美肌瘦身祕笈 etc. Her blog can be accessed here: She has become quite famous recently because of her participation in the TVB reality programme "Bride Wannabes"[1] (盛女愛作戰).

Dr Christian Jessen is an English doctor and a TV personality. He is best known for his presentation in "Supersize vs Superskinny" which was broadcasted in BBC Channel 4. He is a regular columnist of The Daily Mail, The Evening Standard as well as the FHM. He has written an accompanying book for the TV show entitled Supersize vs Superskinny: Take Control of Your Weight. His personal website can be accessed here:

The television shows

Supersize vs Superskinny is a television show, presented by Dr Jessen, describing a pair of clients in each issue - one supersized (overweight) and one superskinny (underweight). In each episode the pair is invited to a house for a week of weight treatment - they are presented of what their eating habits were, how their eating habit came, and how they damage their body, and what change do they have to make in order to become healthier. They are released home, and at the end of the episode they have a debriefing showing their progress.

Bride Wannabes is a television show showing five middle-aged[2] ladies and their progress on finding love. In the process, their "life-coach", Miss Winnie Leung, together with others such as the matchmaking specialist Mei-Ling[3], provides the five ladies with various improvement programs on their outlook, the way they communicate, among other things - and they are offered chances to meet men in various activities. They are given time to express themselves, and more often than not, put into cut-scenes showing a contrasting picture on how others viewed them.


To boot, the UK television show is much better received than the Hong Kong show although the Hong Kong show is only beginning with the fourth episode being aired as of the day of writing. Where's the difference?

Readers are suggested to have a look on the episodes of each show. The TVB show can be viewed in mytv:

The UK television show, although not supposed to be viewable online for non-UK citizens, the following youtube search can probably yield dozens of episode available... (Warning: very addictive)

To be continued...

[1] I didn't invent the name - it's TVB's official translation.
[2] Not in the medical sense, this middle-aged refers to women in their late twenties to late thirties.
[3] Whose comment was critical, dead-on and very interesting...

Wednesday, April 11, 2012

TCM practitioners and Laboratory medicine (and other investigations)

To be honest I really do not understand why these TCM practitioners/herbalists are increasingly utilizing laboratory medicine to extend their patient care...

What is the trouble?

The trouble is not of the fact that they could order tests - any layman can order tests themselves and submit their blood sample to the laboratory - some laboratories even offer to take your blood and test it right away provided that you give up your almighty buck to them.

It is also not the fact that they are not (western-) medically trained that matters to me. To be honest I have little problem with bonesetters requesting radiographs - it is in fact helping the patient very much as these radiographs often come with accompanying reports (that are, indeed, easy to read - e.g. "avulsion fracture of the proximal end of the left 5th metatarsal" would be unmistakably understood, and referred to the orthopaedic surgeon)

The trouble is with interpretation. It is perhaps a convention that the common requests for the clinical chemistry laboratory are reported but not interpreted (e.g. blood gas, liver and renal function test panels, etc. see note 1.) and in fact interpreting the liver and renal function tests has not been an easy task even for some specialists... I have recently come across a patient with significant hyponatremia. He was diagnosed to have the syndrome of inappropriate ADH secretion "SIADH", even (1) in a dry clinical picture and  (2) he has been on a thiazide diuretic before admission.

The truth is that interpreting tests takes time and training to learn - and it is important to learn in a supervised manner, that you get the feedback from your senior that your interpretation is wrong.

It is not the first time for us to see people with chronic hepatitis B managed by certain herbalists missed their chance of curative treatment for hepatocellular carcinoma (liver cancer) even though their biochemical picture is strongly suggestive of space-occupying lesions in the liver.

If they are not trained to do the interpretations correctly perhaps they shouldn't order it at all. It's just like calling a medical doctor to look at all the gauges and meters in the nuclear facility.

[1] Of course there exists tests that are interpreted, e.g. Serum electrophoresis, etc. but the majority of tests are not interpreted.

Sunday, April 8, 2012

Friday, April 6, 2012

The 80s generation - education

This is definitely a complex socioeconomic phenomenon that one must write about these days.

They are born in the years of prosperity that last through their young childhood. Then they see the recessions. Not once. Not twice. Not thrice. Perhaps there has been too many recessions for them, occurring too frequently for them to adapt to even one. 


To be honest, education is one thing that has been in turmoils for people born in the 1980s. It is not that they have not enough options. It is that they have too many options - and mind you, that is not so much of a good thing.

For those born in the 70s, when they have finished their school certificate examination, they can study up to matriculation (which, they can apply for universities/higher education afterwards), or they can come out and work. There are the vocational schools e.g. Haking Wong Technical Institute[1], which allows youngsters to be trained into somebody who can do their job really well in a certain sector.

For those born in the 80s, though, as the number of universities grew, higher education became a necessity rather than a privilege, a basic need rather than a luxury. And then the government gave them something called "associate degree" which (1) cost an arm and a leg, (2) teaches little that is practical, and (3) had extremely lax graduation requirements -- to some, it is almost like selling the diploma rather than doing education[2] - of course it is just an example... but if you can let these people graduate...

It looks really bad -- to the previous generation -- these people born in the 80s are not learning for the sake of learning, they are learning for the sake of not working.

Readers, what do you think?

[1] I can still remember the free soup that was available in the canteen in Haking Wong back in the days. The meals there was affordable, and most importantly, one can be sure that he is well fed there with just $20...
[2] My experience with these associate degree people is that.. I once came across a biological science major - I asked him if he could tell me the features of various phyla of the animal kingdom - he couldn't. I asked the same for the plant kingdom - he couldn't. I asked for the most important cycle in the body - Kreb's cycle - he can't even remember the intermediates (and I was only asking for citrate, alpha-ketoglutarate and oxaloacetate - i wasn't asking for the details). So what kind of biological science major is he....

Thursday, April 5, 2012

Malachite green, melamine, plasticizer and pink bug drink in Starbucks - 4 of 4

Pink bugs in starbucks

IT was quite a sight - I went back to work in the hospital just to find that the nurses are all there chattering about Starbucks drinks made from insect fragments. My first reaction to it was like...

Okay. Topic to write on.


Cochineal is a type of insect that feeds on cactus. It contains a compound known as carmine (wiki) which is usually used as its salt in product as a kind of red colouring. Historically it is produced in Spain and is extremely valuable. The value of cochineal fell much following the discovery of artificial red dyes in the previous century.

So why are we using cochineal?

In fact, this is likely to be the only reasonable red colouring for use in food. The other legal food red colouring these days is Red 40 (wiki) which is under attack[1]. The cochineal red coloring can be obtained in two forms, carmine, and cochineal extract.

Cochineal extract is prepared from a water-alcohol extraction of powdered, dried cochineal.Carmine on the other hand are further filtered and is more chemically pure.

Comments like "Are we eating insect fragments? - Oh I still remember there are quiet a few red fragments there when I had my strawberry frappucino - That must be the insect fragments" are everywhere[2]. These comments are of course factually wrong - if a industrial pulverizer can leave insects fragments alone then it wouldn't be called a pulverizer at all. And we are talking about powdery food additive which are freely soluble in water (and they cannot have insoluble components of more than 1% by weight (by UN standards).

Food standards with regard to insect fragments

To understand the ubiquity of insects in our common food, one must understand what standards are set there - FDA (of america) has set some ground rules for food in america (and those approved in america are usually allowed in Hong Kong - go figure). These are a few examples of "action level" of FDA[3] (i.e. they will accept the product if the count is below these...):

(1) Cinnamon, ground - 400 or more insect fragments per 50 gram
(2) Chocolate -  60 or more insect fragments per 100 grams
(3) Canned orange juice - 5 or more fly eggs per 250 ml

Can you imagine you accepted a can of orange juice with 4 fly eggs? I guess if these are acceptable, cochineal extract is just a mere mental inconvenience... Plus it is healthier than those artificial substitutes... 

[2] "...不免令人聯想到,可能是被攪碎的蟲子翅膀、身體...", "...現在想想,難道這就是尚未被碾碎的蟲子翅膀或其他身體部分..." etc. Obtained from a google search on "胭脂蟲 翅膀 starbucks"

Tuesday, April 3, 2012

Malachite green, melamine, plasticizer and pink bug drink in Starbucks - 3 of 4


There has been quite a fuss surrounding taiwanese drinks back then in 2011 - you hear all those 'completely artificial' drinks from taiwan and many of us stopped buying drinks from these taiwanese outlets. Whereas it is true that these drinks are artificial, the health impact they had in human is debatable.

The case was that a supplier of clouding agent added a plasticizer called Bis(2-ethylhexyl)phthalate also known as DEHP into its product.

Clouding agent

Clouding agent is a type of food additive which causes the drink to become cloudy.

This cloudy lemonade is an example of what a drink would
look like if a clouding agent is added to it[1]

Typical clouding agent contains gum arabic, palm oil as well as citrus extracts. By nature of its palm oil, it is easy to spoil and gives a rancid taste when spoiled. There, they noted that DEHP, when added to it instead of palm oil, will produce a very nice clouding effect with little chance of spoiling. All these contribute to a better product, except... that DEHP is an antiandrogen (That is, it interferes with male sex hormone production and/or the effect of male sex hormone).

And then, as usual, with the ultra-sensitive investigations available, suddenly we are worried about the presence of DEHP everywhere - taiwanese drinks included. But when it comes to a drug...

There are also other plasticizers similar to DEHP and their toxicity are also similar. 


Augmentin is a very common penicillin-type antibiotics. Arguably, it is the most commonly prescribed antibiotic both in in-patient and out-patient settings - mostly because of its broad spectrum (the ability to kill many different kinds of bacteria).

The tablet of it contained 2.7 ppm of DIDP, 1.1ppm of DEHP and 3.5ppm of DINP.

The powder for syrup reconstitution contained 88ppm of DIDP and 1.4ppm of DINP.

The maximum allowable intake level of DIDP is 2200 microgram per day[2]. 2.7ppm is 2.7mg/kg = 2.7microgram/g. An augmentin 375mg tablet is about 500mg in weight. by proportion, it contains about 1.35 microgram of DIDP. A full course of augmentin thus contain 28.35 micrograms of DIDP (1.35 x 3 times per day x 7 days). The daily dose is about 0.18% of the maximum allowable intake level. One has to take a 500x overdose of augmentin tablet in order to see a reproductive effect of DIDP. To be honest, if one takes a 500x overdose augmentin I would worry about the brain of the patient more than the antiandrogen effect of DIDP/DEHP/DINP...

For the powder, it has a vastly higher amount of DIDP at 88ppm. 88ppm is 88mg/kg = 88 microgram per gram. The 457mg/5ml syrup contain around 1g of powder for 5ml of syrup. Thus, there is 88 microgram of DIDP in 5ml of syrup. A full course thus contain 1232 microgram of DIDP. The daily dosage, which is 176 micrograms, represents 8% of the maximum allowable intake level.

And then they take away all the oral augmentin available from the clinics and hospitals. Compare the risk of patient requiring the use of second line antibiotics (which are more expensive / had more side effects / had narrower spectrum / less suitable) with these small risks of anti-androgenic effect from plasticizers... well, not that the ban is incorrect, but the negative impact is so much worse than the woes it caused.

For the matter, the maximum allowable dose level of DEHP is 418ug/day for adults, 58ug/day for children and 20ug/day for neonates; and none was defined for DINP. One can try to do the mathematics, but it is exceedingly unlikely for anybody to become affected by the dose level available in the syrup or the tablet.

You get the idea.

[1] The picture taken was from a natural cloudy lemonade, which is a mixture of water, sugar and lemon juice. The clouding effect is natural and is not due to a clouding agent. This photo is (C) 2009 JJ Harrison, used per CC-BY-SA 2.5 license. (Further information available from Wikipedia)

Monday, April 2, 2012

Malachite green, melamine, plasticizer and pink bug drink in Starbucks - 2 of 4


Melamine is a trimer of cyanoamide (H2NCN). The industrial use of melamine is basically as a polymer: (after mixing with other chemicals)

(1) Thermoset plastic - melamine resin is very durable. The only problem with it though is that it heats up in microwave, thus it cannot be used in a microwave.
(2) Melamine foam - it can be used as a soundproof/insulation, as well as an abrasive cleaning agent (quite well known by now in Hong Kong and perhaps Japan as 激落君)

On the other hand, since melamine contain more than 60% nitrogen by weight, it has been considered for use as a (rather unsuccessful) nitrogen source in the feed for livestocks[1]. In the melamine-tainted milk incident, it was used to increase the apparent nitrogen content of the milk because some assays measure protein content in milk by measuring the nitrogen content.

The acute toxicity of melamine is very low. the LD50 (lethal dose-50, i.e. the dosage of the medication to kill 50% of a population, usually of laboratory animals, e.g. mice, rats) is around the same as salt, at >3000mg/kg. Chronic toxicity is another problem - melamine by itself requires consumption of large amount of pure melamine without good water intake. This is almost impossible for adults.

Melamine has been implicated in several incidents, including one involving pet food in the past. Together with the 2008 melamine tainted milk incident, it was noted that melamine primarily cause complications due to two mechanisms:

(1) the hydrolysis product of melamine (co-contaminants due to the use of low quality of melamine) inhibits a liver enzyme called uric acid oxidase which decomposes uric acid - this leads to a high blood, and thus urine level of uric acid and cause kidney problems.
(2) melamine is also excreted unchanged in the kidneys, causing stone formation.

Again - the addition of melamine is one act of pure fraud. It is definitely not something acceptable in any society. but then as talked the day before, the dose defines the poison. In the Sanlu milk that caused this whole scandal, the dose detected was up to 2,500mg/kg (=part per million, and later up to >6197mg/kg), which is very high - and this dose is only causing the disease in infants because they almost do not drink anything else - the lack of water intake increases the precipitation.

The story in Hong Kong

According to the Centre for Food Safety, melamine-tainted food that has been seen in Hong Kong had concentration up to 68ppm (in chocolate bars).This level, together with the target population, is unlikely to cause any damage even in the worst case scenario (child eating it as the only food - in which case the parents should be prosecuted for child abuse I think).

And then we see a boycott of milk products from China, as well as all other diary products in Hong Kong because of a detection of concentration averaging around 3 part per million.

And then we saw the hospital authority opening special clinics for those children who "supposingly" had taken melamine-tainted milk. To be honest, if anything, if we have a look at the balance between:

(1) Loss of work hours of parents and study hours for children
(2) Risk of contracting disease from clinic attendence
(3) Delay of other patients in same / different department (e.g. ultrasound appointment)
(4) Pressure of work to our paediatric colleagues


(1) The remote risk of having renal disorders from locally bought milk powder/other products

I think most of us could judge.If the child had Sanlu, Mengniu or Yili infant milk powder from China I think it is very acceptable for doctors to consider a streamlined investigation protocol for them. For others, I think the readers can now decide.

[1] The use of non-protein nitrogen sources in animals has been a practice in farming for quite some time - compounds such as ammonia, urea and biuret can be feed to the ruminants and would eventually be incorporated into protein for the animal because of bacterial action in the ruminant stomach.

Sunday, April 1, 2012

Malachite green, melamine, plasticizer and pink bug drink in Starbucks - 1 of 4

It is not news that people are easily manipulated[1].

The collective stupidity of people never fails me... Looking at the list of feared substance that occur in Hong Kong, I can only say, good luck, my friend. Below lists a handful of substance that has been publicized in Hong Kong for being added to food (legally or illegally) and are of utmost hazard to your health:

(1) Malachite green
(2) Melamine
(3) DEHP (Bis(2-ethylhexyl) phthalate and other similar plasticizer)
(4) Cochinea colouring

This is the first installment of a four-article series on the public reaction to chemical substances identified in food.

Malachite green

Malachite green is an aniline dye which is commonly used in production of green articles made of e.g. silk, leather or even toilet paper. Another use of it is in eradicating protozoan disease, notably Ichthyophthirius multifiliis which is better known as white spot disease (白點病), a prevalent parasite of freshwater fish. 

Malachite green has been implied in causing cancer, change in genetic material, abnormal babies as well as toxicity to lung[2]. Together with its metabolite in fish, leukomalachite green, these produces an increase of liver DNA adduct in rats (a measurement of genotoxicity), in a dose-related manner in concentrations above 91ppm[3]. There is also an increase in lung adenoma (a benign tumor) in the tested rats.

There is, however, in this 2-year tumorigenesis study, no increase in the occurence of liver tumor.

According to the press release by CFS, HKSAR[4], the samples concerned contained  16ppm and 0.0025ppm respectively (by LC-MS/MS among other methods[5,6]), well below the concentration that has been observed to cause significant genotoxicity.

In fact, most of the samples acquired in Hong Kong afterwards contained up to 5ppb (part per billion) only - which is, higher than the EU directive (<2ppb) but lower than the Japanese directive (<10ppb).

The ban is correct

I for one am surprised that samples would contain as much as 16ppm, far above the possibility of contamination, and this points much more to (illegal) usage of malachite green in that particular case. The ban means that future products would be tested for it with sensitive assays and the fisheries will have an incentive NOT to use malachite green in their fish-farming practice.

But the reactions are stupid

The dose makes the poison - Paracelsus

The trouble though, with these incident is that most of those who wrote about these had little idea that toxicity is related to the dose - even something as innocent as pure water or pure oxygen could be a poison if given in large enough a dose and/or long enough a time period, but even cyanide could be nontoxic if given in small enough a dose.

What people says about these malachite green-tainted eels?

"致癌鰻魚驚世大發現"[7] - Written by a chemistry teacher.

What's the deal? The dosage isn't even remotely near the carcinogenic levels. To make it worse, he further wrote "孔雀石綠經已被証實為可以致癌的物質" - when has it been classified to be a known carcinogen? The WHO publishes a list of known carcinogen - one can check here. There are some borderline evidence of carcinogenesis - e.g. a significant increase in "pooled liver adenoma and carcinoma"[8]. Yes, one can say that it is a potential carcinogen (with all the indirect evidence) but proven to be carcinogenic?

And then the worst in the article: "右圖為被過量孔雀石綠浸過的甲魚,魚身已被染成綠色" - what's remaining in the malachite green tainted fish is mostly leukomalachite green which had longer half-life (of 10 days) than malachite green - which is not coloured at all. To add to it, the observed amount (even the wow-factor 16ppm detected) will unlikely add any colour to the specimen.

Please, for god's sake - learn before you teach.

[1] Do you really expect a source on this? It's April Fool's day!
[2] Srivastava S, Sinha R, Roy D. Toxicological effects of malachite green. Aquat Toxico. 2004 Feb 25; 66(3): 319-29.
[3] Culp SJ, Beland FA, Heflich RH et al. Mutagenicity and carcinogenicity in relation to DNA adduct formation in rats fed leucomalachite green. Mutat Res. 2002 Sep 30;506-507:55-63.
[5] Tang HPO, Choi JYY, Analysis of Malachite Green in Fish Samples. Downloaded from:,
[6] Tang HPO, Choi JYY, Analysis of Malachite Green in Fish. Downloade from:
[8] Culp SJ, Mellick PW, Trotter RW et al. Carcinogenicity of malachite green chloride and leucomalachite green in B6C3F1 mice and F344 rats. Food Chem. Toxicol., 44 (2006), pp. 1204–1212.


Democracy has been promoted by so many proponents of it that it is almost impossible to criticize democracy in front of people without triggering a flamewar instead of a fruitful discussion. In fact democracy has been popularized to the point that those speaking about it often have no idea what is being represented by the term.

The term democracy comes from the Greek word demokratia, which is the combination of the term demos (people) and kratos (power). Essentially, the aim of any democratic system would be to grant the power back to the people.

In my humble opinion there is really not a need to talk about the benefits of a democratic society - though, to be honest, most of the quoted benefits of the democratic society are actually the prerequisite of a democratic society, not an effect of it (and these includes freedom of speech, freedom of political expression, freedom of press, etc.)

One major problem of democracy is that of a mob rule. The treatment by Plato on this subject is at least interesting (if not practical enough) to read. Mob rule refers to the situation in which the majority utilizes its power via democracy to intimidate, or even harm minority groups. Another situation that could also be referred to mob rule is when the majority in the society elects (or intimidates the government) for a certain action to be passed, when the action itself may not be for the better in the long run.

Look at the $6,000 scheme by the Government of Hong Kong last year.

In my opinion, the government has been doing a disservice to the society by changing its decision from investing six grands into people's MPF account to dispensing cash. The problem is that many of us are not being protected adequately by our retirement scheme and the approval of such decision is only making the government more liable in terms of social security spending because these people who do not save it up and spend the money right away are likely to be the people who would rely on the social security policy for their "retirement plan" in the long run.