1.Lactose tolerance and intolerance in Malaysians
International e-Journal of Science, Medicine and Education 2012;6(supp1):S12-S23
This review explores the digestibility of
lactose by Malaysians, and the value of milk and other
milk-derived products as sources of appropriate nutrition
for Malaysians. Increased calcium intake through
consumption of milk is an effective mechanism for
increasing calcium uptake from the diet and thereby
minimising the risk of development of osteoporosis in
later life. Detailed information about rates of lactose
intolerance, and adaptation to dietary lactose and
its consequences for Malaysians, will help in the
formulation of dietary advice, and improve commerial
food manufaturing practice and Government policy
directed to the minimization of rates of osteoporosis,
which presents a substantial morbidity risk to elderly
female Asians in particular.
2.The pH of very dilute solutions of strong acids – a calculation for a medical or biomedical class involving the application of simple numerical skills
International e-Journal of Science, Medicine and Education 2012;6(2):32-38
This paper presents the solution to a calculation
of the pH of a very dilute solution of a strong acid or
base, taking into account the effect of the hydronium
or hydroxyl ions generated from the ionisation of the
strong acid or base on the ionisation of water, as a
second very weak acid. To be solved successfully, this
calculation involves the concepts of conservation of
charge, pH and the application of the general solution
to a quadratic equation. Such an exercise involves the
application of skills in basic numeracy, and can provide
a core of understanding that can prepare students for
many different sorts of calculations that represent reallife problems in the medical and biological sciences.
A programme is presented in C++ which enables the
work of students to be individualised so that each
student in a class can work through a slightly different
pH calculation, in such a way that a class supervisor
can quickly check each student’s result for accuracy.
This exercise is presented as a potential means of
enabling students to undertake and master similar
types of calculations involving simple or more complex
equilibria.
3.The pH of very dilute solutions of weak acids – a calculation involving the application of numerical skills to the solution of a cubic equation
International e-Journal of Science, Medicine and Education 2014;8(2):24-29
This paper presents the solution to a
calculation of the pH of a very dilute solution of a weak
acid, taking into account the effect of the hydroxonium
ions generated from the ionization of the acid on the
ionization of water, also a very weak acid. To be solved
successfully, this calculation involves the concepts
of conservation of charge, pH, equilibria and the
application of the general solution to a cubic equation.
Such an exercise requires the application of skills in
algebra, and can provide a core of understanding that
can prepare advanced students for many different sorts
of calculations that represent real-life problems in the
chemical sciences. A programme is presented in C++
which enables the work of students to be individualized
so that each student in a class can work through a
slightly different pH calculation, in such a way that a
class supervisor can quickly check each student’s result
for accuracy. This exercise is presented as a potential
means of enabling students to undertake and master
similar types of calculations involving the application
of complex algebra to problems related to equilibria and
solution dynamics.
4.Oily fish, liquid wax esters and keriorrhoea – a review
Peter Michael Barling ; Yi Huan Foong
International e-Journal of Science, Medicine and Education 2015;9(1):21-25
Keriorrhoea is the involuntarily passing
of orange oil per rectum. One of us (PMB) had the
misfortune to experience this symptom, together
with considerable gastrointestinal disturbances for a
prolonged period of time after consumption of a deep
sea fish, orange roughy, which is rich in liquid wax esters
(LWEs). This paper presents a summary of available
evidence concerned with the physiology and pathology
of ingestion of LWEs, which can enter the human diet in
substantial amounts from consumption of several species
of deep-sea fish. LWEs are poorly digested and absorbed
by the human body. They generally cause keriorrhoea
when ingested deliberately or accidentally. Jojoba oil,
which is a plant LWE, together with certain nutritional
products (e.g. olestra) and medical (e.g. Orlistat) which
are not LWEs may mimic the effects of LWEs, and
cause similar gastrointestinal disturbances. This paper
discusses the potential effects of LWEs as components of
gastrointestinal micelles, and predicts that the orange oil
which is leaked from a bout of keriorrhoea may contain
considerable volumes of triacylglycerols (TAGs).
Lipase