Friday 28 September 2012

Diabetes mellitus

Discovery of insulin
One of the great stories from medical history is Banting and Best's visit to the terminal ward where children with juvenile-onset diabetic coma went to die. The two went down the line of children injecting insulin. As they were finishing, the first children injected were already awake. Insulin was available in 1922 from Eli Lilly and Company. Eli Lilly was a chemist. Best assisted Captain Banting. Collip assisted Macleod. Macleod and Banting won the 1923 Nobel Prize for Physiology or Medicine. Each then shared their prize with their assistants. Sir Frederick Grant Banting died during WWII in 1941 and was buried in Mt Pleasant in Toronto, Canada.

Pancreatic disease
http://www.pathguy.com/lectures/pancreas.htm

Diabetic problems
  1. Gallstones (made of cholesterol; nobody knows why these are more common in diabetics, but the average gallbladder volume is much higher in non-insulin-dependent diabetics, perhaps promoting stasis and nidation: Dig. Dis. Sci. 43: 344, 1998.)
  2. Altered platelet function (significance?)
  3. Complications of pregnancy -- all the common problems are commoner in diabetic mothers, and babies are bigger (partly the hyperglycemia, probably partly some growth factor or other: Br. J. Ob. Gyn. 103: 427, 1996) and at extra risk for a variety of birth defects (all of which seem to be preventable by euglycemia through pregnancy).
  4. Diabetic xanthomas (yellow skin bumps -- pseudotumors made of lipid-laden macrophages), necrobiosis (focal necrosis of the dermis), and many other skin abnormalities
  5. Infections (bacterial and fungal) -- Why diabetics get more infections is still poorly-understood. Candida may thrive on the glucose, hyperglycemia slows down polys, poor circulation keeps the body from fighting infection, etc., etc.).
  6. Babies of diabetic mothers have hyperplastic islets (because of all that glucose), and they are infiltrated with lymphocytes and eosinophils (mysterious.)
  7. Eyes -- Diabetes is the commonest cause of blindness before old age in the US. Review: Lancet 350: 197, 1998. Cataracts: a variety of types, including some clearly caused by sorbitol deposition (proof Proc. Nat. Acad. Sci. 9: 2780, 1995; remains a robust finding). Glaucoma: reason for its being more common with diabetes is uncertain. Diabetic retinopathy: the most serious diabetic eye problem (Lancet 376: 124, 2010)
  8. Kidneys -- The etiology of diabetic glomerulopathy is complex and poorly-understood. Intrarenal fluid dynamics are involved. We don't even know why the kidneys enlarge in diabetics (NEJM 324: 1662, 1991, still good). Tight control of blood glucose does seem to benefit these patients, and reduces the hyperfiltration response to amino acids (NEJM 324: 1629, 1991). Patients are now put on ACE-inhibitors and protein-restricted to prevent progression of the renal disease. (Yes, it can regress due to therapy: NEJM 348: 2285, 2003). Ace-inhibitor plus a calcium channel blocker works marvellously to prevent diabetic kidney disease: NEJM 351: 1941, 2004. Renal lesions in diabetes: Thick tubular basement membranes (not a health problem). Fatty change of tubular cells (systemic lipid disturbance, not a health problem). Glycogen in proximal tubular cells (Armanni-Ebstein lesion, a sign of heavy glycosuria, not itself a health problem). Lots of glycogen in the tubular cells. Kidney infections (gram-negative bacilli causing infection of renal pelvis in pyelonephritis, staphylococci causing cortical infections, candida infections, etc.) Sometimes present: "Fibrin caps" ("exudative lesion", "hyperfiltration lesion") -- hyaline frosting on a glomerular tuft; "Capsular drops" -- hyaline material on the inside surface of Bowman's capsule (highly characteristic of diabetes.) Clinically, patients have albuminuria (rarely heavy proteinuria), then renal failure (probably due to the mesangium crunching the glomerular capillaries). Renal papillary necrosis -- just like it sounds. The lesion is seen in diabetes, obstruction, sicklers, Wegener's, or abuse of the analgesic phenacetin.)

Thursday 27 September 2012

Psychiatry and Psychology

Neurosis

Catecholamines


  1. Catecholamines are chemical compounds derived from the amino acid tyrosine (Tyr) that act as hormones or neurotransmitters. They are examples of phenethylamines.
  2. Catecholamines are soluble, and so they can circulate dissolved in blood.
  3. The most abundant catecholamines are epinephrine (adrenaline), norepinephrine (noradrenaline) and dopamine. They are produced mainly from the adrenal medulla and the postganglionic fibres of the sympathetic nervous system.
  4. Adrenaline acts as a neurotransmitter in the central nervous system (CNS) and as a hormone in the blood circulation. 
  5. Noradrenaline is primarily a neurotransmitter of the peripheral sympathetic nervous system but is also present in the blood (mostly through "spillover" from the synapses of the sympathetic system).
  6. High catecholamine levels in blood are associated with stress. Catecholamines cause general physiological changes that prepare the body for physical activity (e.g. exercise). Some typical effects are increases in heart rate, blood pressure, and blood glucose levels. 
  7. Some drugs, like selegiline, raise the levels of all the catecholamines. Selegiline (l-deprenyl, Eldepryl® or Anipryl® [veterinary]) is a drug used for the treatment of early-stage Parkinson's disease and senile dementia


Selegiline

Endocrine System

http://www.biologydaily.com/biology/Endocrine_system

Hormones
http://www.biologydaily.com/biology/Hormone

Endocrine glands
An endocrine gland is one of a set of internal organs involved in the secretion of hormones into the blood. The other major type of gland is the exocrine glands, which secrete substances—usually digestive juices—into the digestive tract or onto the skin.

A list of major endocrine glands:
  1. pituitary gland
  2. adrenal gland
  3. thyroid gland
  4. gonads
  5. parathyroid glands
  6. pancreas
  7. thymus

Circulatory System

History of Discovery
http://www.biologydaily.com/biology/Cardiovascular

Pharmacology

http://www.biologydaily.com/biology/Pharmaceutical

http://www.biologydaily.com/biology/Nifty_Fifty

Medical Equipment

New & used pulmonary medicine equipment
http://www.medwow.com/used-pulmonary-medicine-medical-equipment/29.syn

Wednesday 26 September 2012

Acid-Base Imbalance (Phase 2 MD)

Acid Base Balance
http://www.youtube.com/watch?v=i_pTaTveCCo&feature=related

Metabolic and Respiratory Acidosis and Alkalosis
http://www.youtube.com/watch?v=Vl9KvDH2xeI&feature=related

drifter120:
Clinical Application of Blood Gases: Introduction
http://www.youtube.com/watch?v=Py5AyRCliy8&feature=relmfu

Clinical Application of Blood Gases, Part 1: CO2
http://www.youtube.com/watch?v=d1jb-9VAmjM&feature=related

Clinical Application of Blood Gases, Part 2: pH
http://www.youtube.com/watch?feature=endscreen&NR=1&v=IBJtQtzN7O8

Clinical Application of Blood Gases, Part 3: Bicarb
http://www.youtube.com/watch?v=d1jb-9VAmjM&feature=related

Clinical Application of Blood Gases, Part 4: Acidosis
http://www.youtube.com/watch?v=7s6OGhMfUqI&feature=relmfu

Clinical Application of Blood Gases, Part 5: Alkalosis
http://www.youtube.com/watch?v=LcmjGMWDbXw&feature=relmfu

Clinical Application Blood Gases, Part 6: Compensation
http://www.youtube.com/watch?v=t9x4tB9GOi8&feature=relmfu

Clinical Application of Blood Gases, Part 7: O2
http://www.youtube.com/watch?v=NICzxSWYqUo&feature=relmfu



Acid Base Disorders

Medical Acid Base Explained (8 videos)
  1. http://www.youtube.com/watch?v=4wMEMhvrQxE&feature=related
  2. http://www.youtube.com/watch?v=GmEeKVTpOKI&feature=relmfu
  3. http://www.youtube.com/watch?v=caOXZi6YPnU&feature=relmfu
  4. http://www.youtube.com/watch?v=2wMShkaRrRs&feature=relmfu
  5. http://www.youtube.com/watch?v=e-lJ7SmqnxA&feature=relmfu
  6. http://www.youtube.com/watch?v=u4GwLG2Gcwo&feature=relmfu
  7. http://www.youtube.com/watch?v=YSyEZmW6afE&feature=relmfu
  8. http://www.youtube.com/watch?v=ODf_DKfjBGc&feature=relmfu

survivenursing:
Arterial Blood Gas (ABG) Tic-Tac-Toe Examples

Arterial Blood Gas (ABG) Tic-Tac-Toe Full Compensation Examples


Part 1: Acidosis and Alkalosis: Metabolic or Respiratory

Part 2: Acidosis and Alkalosis: Metabolic or Respiratory


Dr Paul:-
Respiratory Alkalosis (Most Important Things To Know)

Respiratory Acidosis

Metabolic Acidosis (Most Important Points)
http://www.youtube.com/watch?v=SQ98EWPmPXE&feature=relmfu

John Bielinksi:
Secrets of Metabolic Acidosis: KUSSMAUL breathing
http://www.youtube.com/watch?v=NIF_7yE-8Js&feature=related

Secrets of Acid-Base / ABG Clinical Analysis
http://www.youtube.com/watch?v=EIQy8rXPSmE&feature=relmfu


ABG Procedures:
Arterial Blood Gas Sampling Procedure
http://www.youtube.com/watch?v=tv7GnAUgKjM&feature=related

Arterial Puncture for Blood Gas Analysis
http://www.youtube.com/watch?v=YuFK22n-tvI&feature=fvwrel

Arterial Blood Gas Collection - Preview
http://www.youtube.com/watch?v=WVFvr5LjTvM&feature=related

Arterial Blood Gas Demonstration
http://www.youtube.com/watch?v=0Rr6vpFMKPE&feature=related


Board Exams
COMLEX USMLE Board Prep Review of Metabolic Acidosis
http://www.youtube.com/watch?v=9MPY8cbou1c&feature=related

ABG Interpretation
http://www.youtube.com/watch?v=zZ3-GXPepWQ&feature=fvwrel

ABG Analysis - Nursing
http://www.youtube.com/watch?v=1yHDtWK9zSo&feature=related

RNA

Chemical Structure of RNA
http://www.nature.com/scitable/topicpage/chemical-structure-of-rna-348

RNA Functions
http://www.nature.com/scitable/topicpage/rna-functions-352

RNA Splicing
http://www.nature.com/scitable/topicpage/rna-splicing-introns-exons-and-spliceosome-12375

RNA Transcription
http://www.nature.com/scitable/topicpage/rna-transcription-by-rna-polymerase-prokaryotes-vs-961




Restriction Enzymes

Restriction Enzymes
http://www.nature.com/scitable/topicpage/restriction-enzymes-545

E. coli

Genome Packing in Procaryotes - circular chromosomes of E.coli
http://www.nature.com/scitable/topicpage/genome-packaging-in-prokaryotes-the-circular-chromosome-9113


Gene

What is a gene?
http://www.nature.com/scitable/topicpage/what-is-a-gene-colinearity-and-transcription-430

Eucaryotic Genome Complexity
http://www.nature.com/scitable/topicpage/eukaryotic-genome-complexity-437

Copy Number Variations
http://www.nature.com/scitable/topicpage/copy-number-variation-445

Copy Number Variation and Genetic Disease
http://www.nature.com/scitable/topicpage/copy-number-variation-and-genetic-disease-911

Copy Number Variation and Human Disease
http://www.nature.com/scitable/topicpage/copy-number-variation-and-human-disease-741737

DNA Deletion/Duplication and Associated Genetic Disorders
http://www.nature.com/scitable/topicpage/dna-deletion-and-duplication-and-the-associated-331

Tandem Repeats and Morphological Variation
http://www.nature.com/scitable/topicpage/tandem-repeats-and-morphological-variation-40690

DNA Transcription

DNA Transcription
http://www.nature.com/scitable/topicpage/dna-transcription-426

Translation of DNA to mRNA to Protein
http://www.nature.com/scitable/topicpage/translation-dna-to-mrna-to-protein-393

DNA Replication

Molecular Events of DNA Replication
http://www.nature.com/scitable/topicpage/major-molecular-events-of-dna-replication-413

Semi-Conservative DNA Replication
http://www.nature.com/scitable/topicpage/semi-conservative-dna-replication-meselson-and-stahl-421

Genetic Mutation

Genetic Mutation
http://www.nature.com/scitable/topicpage/genetic-mutation-1127
http://www.nature.com/scitable/topicpage/genetic-mutation-441

DNA Mutation

Errors in DNA Replication and Causes of Mutation
http://www.nature.com/scitable/topicpage/dna-replication-and-causes-of-mutation-409

DNA Repair

DNA Damage and Repair Mechanisms
http://www.nature.com/scitable/topicpage/dna-damage-repair-mechanisms-for-maintaining-dna-344

Structure and Function of DNA

Structure of DNA by Watson & Crick:
http://www.nature.com/scitable/topicpage/discovery-of-dna-structure-and-function-watson-397

Study questions:

  1. What are nucleic acids?
  2. What is the genetic or hereditary material in man/humans?
  3. What are the genetic or hereditary materials in bacteria?
  4. What are the genetic or hereditary materials in viruses?
  5. Can bacteria transfer their genetic/hereditary material to humans? How?
  6. Can viruses transfer their genetic/hereditary material to humans? How?
  7. What is the structure of DNA? What does DNA contain? 
  8. How does DNA multiply (replicate) itself?
  9. What is the structure of RNA? What does RNA contain?
  10. Can DNA be generated from RNA and vice versa?

DNA Animations & videos:

The Doctor Who Cures Cancer

Dr Emanuel Revici - medical breakthroughs and innovative treatments:
http://bit2.ca/categories/Lpg.asp?IdLnk=189699450

Reverse Diabetes

Using mind control and refraining from certain foods in order to control diabetes
http://bit2.ca/categories/Lpg.asp?IdLnk=723077648

Study questions:

  1. Will the pancreas be able to respond when the food intake changes?
  2. Will the pancreas regenerate the portions lost to diabetes?
  3. Is the pancreas regenerative; can it regenerate?
  4. How does the pancreas regenerate or rejuvenate?
  5. Under what conditions will the pancreas respond and heal itself?

Human Anatomy and Physiology

Home Study Course is good if you plan to study before class and be prepared before coming to class.
http://www.humananatomycourse.com/index-opt.htm

Monday 24 September 2012

Academic Session 2012/2013

We now teach separately: PPSP will teach only medic students; PPSG will teach only dental students.

  1. PPSP teaching is now split from PPSG teaching
  2. # of new Year 1 students: 166
  3. Repeat Year 1: 13
  4. Total Year 1 students: 179
  5. Years 2 & 3 are still combined

Saturday 22 September 2012

Child marriage

How young do girls get married? As young as age 5 years!!! Yes, there is practice in various parts of the world where children are married off! Weeee eeeee ... off to another man..... off to another home!! This is reality. Would you marry off your daughter at a young age? Are we helping the young girls by letting them marry young?

http://www.youtube.com/watch?v=7c_zppPutQw&feature=related

Marlie's nose

Everyone has a nose. Where is it? What is it for? It looks beautiful to have a nose. But some kids have problematic nose. Marlie's nose is big - why? How big can the nose get when things go wrong? What went wrong with Marlie's nose? What is the cause of Marlie's nose? How can we help her?


http://www.youtube.com/watch?feature=endscreen&v=xk7yEj4g5YI&NR=1
http://www.youtube.com/watch?v=Mc3W80f7Yos&feature=related
http://www.youtube.com/watch?v=co1JIl9v-TQ&feature=related

Friday 21 September 2012

The eyes have it, the hair shows it

Have you ever seen a kid who is out of place? Have you ever seen a girl with green eyes at the bus station in Butterworth? She's Malay, but probably of Aryan origin. Have you ever seen a little boy in Pakistan who has blue eyes?! Have you ever seen a little girl in India who has hazel eyes, like glass?! I once had an Indian family as a neighbour. They were from India. The entire family had green eyes! They moved to Australia. I have a male cousin who has green eyes. Have you seen beautiful eyes in children? What causes these beautiful eyes we see in people, young and old? They are descended from the Aryan people or race. Who or what are they?

Aryan means noble or honoured. Ariane is a popular Malay name. It is believed that the Aryan race is noble. All races are noble in our eyes. The Aryans are diverse and comprise some of the people living in Iran, India, Afghanistan, Pakistan, Kashmir, Burma and many other places, including along the ancient Silk Route, in some parts of China, and in northern Malaysia. Where did they come from? They were probably descended from the white people who had green or blue eyes, possibly from the Greeks, and the Syrians, etc.

From our glorious history, Alexander the Great was thought to have come this far from Greece, before he turned his army back and returned to Greece, but he died on the way home and did not reach Greece. Of course, when the Greek armies invaded these Asian countries one after the other, the Greek soldiers could have captured and raped the women (this is a common practice) and this gave rise to the first generation of green eyes, which through in-breeding, keeps the green eye colour within a specific clan. The same could have happened to the other invaders of Asia - a barbaric tribe came, battled, won, raped the women, and moved on, leaving their marks behind.

The Syrian people are thought to be the descendants of Nabi Yusuf a.s. We know from Islamic history that he was a beautiful prophet and was much adored by the ladies of his time. He married Zulaikha, the former wife of the Governor Abdul Aziz. So Syrian women have beautiful eyes and hair, and are generally very beautiful. We were told by our tour group leader and ustaz in Makkah that Syrians are beautiful as they are descended from Nabi Yusof a.s.

We can see some Greek features and eye structure of the children below, who were spotted in the countries mentioned above, but not Greece.


Very American or Irish but found in Afghanistan

She definitely resembles Alexander the Great, a Greek
She looks Syrian and partly Greek
He has my maternal grandfather's face and smile; he was a Pakistani (Sindhi)
Deceptive eyes
Looks Irish
She resembles my youngest daughter
Beautiful green eyes of an Indian schoolgirl
An Indian woman with green eyes, definitely Greek
An Afghan lady, Sarbat Gula. She was photographed by the National Geographic for its magazine cover. She was probably 35 years old in 2003/4. She should be 45 in 2012. The National Geographic team returned to locate and interview her but the culture there prevents that. She is married and has kids. She didn't speak English. Her facial features did not change much. Her eyes are green.
http://www.youtube.com/watch?feature=endscreen&NR=1&v=URqN0Iu64D4
http://www.youtube.com/watch?NR=1&feature=endscreen&v=8hHMwCE3ECU
http://www.youtube.com/watch?feature=endscreen&v=BOj0nzuPLMY&NR=1
http://www.youtube.com/watch?feature=fvwp&NR=1&v=qA5G1rKQTJg

King Tut's DNA

Since we have settled things which have to do with the Human Genome Project (HGP), now it is time is study King Tut's DNA. What was King Tut's genomic DNA like? Did he have DNA like ours? Did he have the same chromosomes as males today? Did King Tut have the 43 + XY genetic make-up? Did he have the same genes as ours? Did he have genetic markers like we have? How do we know his parents and grandparents? What blood group did King Tut have? Do we have to dig up all the mummies in the pyramids to find out? Do we have to open up all the mummies to find out? What exactly do we have to do to find out what King Tut's genetic makeup was like? Any clues? Is it exciting to learn about the usefulness of DNA applications? What else can we do with DNA?


http://www.youtube.com/watch?v=Y_zBVrgwkb4&feature=related

Ancient Egyptians

What did the people of ancient Egypt look like? Did they look like Africans? Were the ancient Egyptians descended from the Africans or vice versa?


http://www.youtube.com/watch?feature=endscreen&NR=1&v=fGJFrnMYQEc

Not high cholesterol but inflammation that causes heart attack

How safe is cholesterol? How safe is high cholesterol? How unsafe is omega-6 oil? How safe is omega-3 oil? How safe/unsafe is omega-9? What actually causes heart attacks? Does high cholesterol kill? Does inflammation of the blood vessel wall kill in the end? Which is more dangerous - inflammation with high blood cholesterol or no inflammation but with high blood cholesterol? Injury to the arterial wall with subsequent inflammation of the arterial vessel wall, are these dangerous features of an impending heart attack? How do we approach and study this problem? What should we know? What is right and what is incorrect today? Have we been misled about high cholesterol causing heart attacks? How do we correct this notion?

http://biococo.com.my/not-high-cholesterol-but-inflammation-that-cause-heart-attack/

Pray for Adam

Baby Adam suffers from HIE (hypoxic-ishaemic encephalopathy). He is cared for at home by his young parents. Follow his story in Facebook.
https://www.facebook.com/Ahmad-ADAM-SYUKRI-SN


Useful links on HIE:
Medscape: http://emedicine.medscape.com/article/973501-overview
Slideshare: http://www.slideshare.net/drAjayAgale/hypoxic-ischaemic-encephalopathy-12745905
Slideshare: http://www.slideshare.net/alanialiraqi/hypoxic-ischemic-encephalopathy

Thursday 20 September 2012

Bioenergetics

Bioenergetics deals with energy in the cell - how the cell derives its energy, what the cell can do when it has sufficient energy, what happens when the cell has insufficient energy, various energy sources for the cell, why we feel weak when we have some illness or fever of some sort, why we feel weak and fatigued, etc.

Keywords: thermodynamics, first law of thermodynamics, second law of thermodynamics, groundstate, high-energy state, low-energy state, free energy, -AG, +AG, graph to show bioenergetics of the cell, reactions that provide energy, reactions that use up energy, ATP, ADP. AMP, energy storage.

http://faculty.ksu.edu.sa/70917/Pages/BCH451.aspx

Tuesday 11 September 2012

Terpenes


INTRODUCTION TO TERPENES

Useful links:
http://en.wikipedia.org/wiki/Terpene
http://en.wikipedia.org/wiki/Osmeterium
http://www.chemie.fu-berlin.de/chemistry/oc/terpene/terpene_en.html
http://www.chem.qmul.ac.uk/iubmb/enzyme/glossary/pinene.html
http://www.nlm.nih.gov/cgi/mesh/2011/MB_cgi?mode=&term=Terpenes
http://www.nlm.nih.gov/cgi/mesh/2011/MB_cgi?mode=&term=Xanthophylls&field=entry


A. CHEMISTRY OF TERPENES

What are terpenes?

Terpenes are a large and diverse class of strong smelling organic compounds produced by plants and insects. Terpenes are found in abundance in the oil of plants and flowers. They have distinctive flavours, odours and colours. They are responsible for the odour of the pine trees, pine wood and pine furniture. They are responsible for the red colour in tomatoes.

What is the building block of terpenes?

Terpenes have isoprene units as a common structural feature.

What are terpenes vs. terpenoids?

When terpenes are modified chemically, such as by oxidation or rearrangement of the carbon skeleton, the resulting compounds are generally referred to as terpenoids. Some authors will use the term terpene to include all terpenoids. Terpenoids are also known as isoprenoids.

What are the types of terpenes?

Terpenes are classified by the number of isoprene units in the molecule; a prefix in the name indicates the number of terpene units needed to assemble the molecule.

(i) From Institute of Chemistry, FU Berlin, Germany:

Terpenes are widespread in nature, mainly in plants as constituents of essential oils. Many terpenes are hydrocarbons, but oxygen-containing compounds such as alcohols, aldehydes or ketones (terpenoids) are also found. Their building block is the hydrocarbon isoprene, CH2=C(CH3)-CH=CH2 (isoprene rule, Wallach 1887). Terpene hydrocarbons therefore have molecular formulas (C5H8)n, they are classified according to the number of isoprene units:

number of isoprene units 
monoterpenes  2 
sesquiterpenes 3 
diterpenes       4 
triterpenes       6 
tetraterpenes   8

Examples of monoterpenes are: pinene, nerol, citral, camphor, menthol, limonene.
Examples of sesquiterpenes are: nerolidol, farnesol.
Examples of diterpenes are: phytol, vitamin A1.
Squalene is a triterpene.
Carotene (provitamin A1) is a tetraterpene.
  • Pinene: alpha- and beta-pinene are bicyclic terpenes, they are the major components of wood turpentine which can be obtained from the resinous sap of pine trees (Pinus) by steam distillation.
  • Nerol, a monoterpene, is a colorless liquid that has a rose scent. It is a constituent of attar of roses, oil of orange blossoms and oil of lavender.
  • Citral a (trans form) and citral b (cis form) are terpene aldehydes, colorless liquids, components of many essential oils that have a strong lemon and verbena odor.
  • Camphor, a bicyclic terpene ketone, is a tough gummy volatile fragrant crystalline compound obtained from the wood and bark of the camphor tree (Cinnamomum camphora, Taiwan) by steam distillation.
  • Phytol, an acyclic diterpene alcohol, is a colorless, high-boiling oil. Esterified, it is part of chlorophyll.
  • beta-Carotene, provitamin A1, is a tetraterpene, forms orange to red crystals and occurs in the chromoplasts of plants and in the fatty tissues of plant-eating animals.
  • Terpenes:

(ii) From Wikipedia:




  • Hemiterpenes consist of a single isoprene unit. Isoprene itself is considered the only hemiterpene, but oxygen-containing derivatives such as prenol and isovaleric acid are hemiterpenoids.



  • Monoterpenes consist of two isoprene units and are derived from the molecular formula C10H16. Examples of monoterpenes are: geraniol, limonene (from orange peel) and terpineol.



  • Sesquiterpenes consist of three isoprene units and are derived from the molecular formula C15H24. Examples of sesquiterpenes are: humulenefarnesenesfarnesol. (The sesqui- prefix means one and a half.)



  • Diterpenes are composed of four isoprene units and have the molecular formula C20H32. They derive from geranylgeranyl pyrophosphate. Examples of diterpenes are cafestol, kahweol, cembrene and taxadiene (precursor of taxol). Diterpenes also form the basis for biologically important compounds such as retinolretinal, and phytol. They are known to be antimicrobial and antiinflammatory.



  • Sesterterpenes, terpenes having 25 carbons and five isoprene units, are rare relative to the other sizes. (The sester- prefix means half to three, i.e. two and a half.) An example of a sesterterpene is geranylfarnesol.



  • Triterpenes consist of six isoprene units and are derived from the molecular formula C30H48. The linear triterpene squalene, the major constituent of shark liver oil, is derived from the reductive coupling of two molecules of farnesyl pyrophosphate. Squalene is then processed biosynthetically to generate either lanosterol or cycloartenol, the structural precursors to all the steroids.



  • Sesquarterpenes are composed of seven isoprene units and are derived from the molecular formula C35H56. Sesquartepenes are typically microbial in their origin. Examples of sesquarterpenes are ferrugicadiol and tetraprenylcurcumene.



  • Tetraterpenes contain eight isoprene units and are derived from the molecular formula C40H64. Biologically important tetraterpenes include the acyclic lycopene, the monocyclic gamma-carotene, and the bicyclic alpha- and beta-carotenes.



  • Polyterpenes consist of long chains of many isoprene units. Natural rubber consists of polyisoprene in which the double bonds are cis. Some plants produce a polyisoprene with trans double bonds, known as gutta-percha.



  • Norisoprenoids, such as the C13-norisoprenoids 3-oxo-α-ionol present in Muscat of Alexandria leaves and 7,8-dihydroionone derivatives, such as megastigmane-3,9-diol and 3-oxo-7,8-dihydro-α-ionol found in Shiraz leaves (both grapes in the species Vitis vinifera) or wine (responsible for some of the spice notes in Chardonnay), can be produced by fungal peroxydases oglycosidases.

  • B. BIOLOGY OF TERPENES

    Where are terpenes found?
    1. Terpenes and terpenoids are the primary constituents of the essential oils of many types of plants (particularly conifers) and flowers. 
    2. Terpenes are released by trees more actively in warmer weather, acting as a natural form of cloud seeding. The clouds reflect sunlight, allowing the forest to regulate its temperature.
    3. Turpenes are the major components of resin, and of turpentine produced from resin. The name "terpene" is derived from the word "turpentine". 
    4. Terpenes are produced by some insects such as termites. Terpenes are used by termites of the Nasutitermitinae family to attack enemy insects, through the use of a specialized mechanism called a fontanellar gun.
    5. Terpenes are produced by caterpillars of the swallowtail butterflies, which emit terpenes from their osmeteria. They are often strong smelling and thus may have had a protective function.

    Conifer resin is a source of terpenes.
    The osmeterium is a fleshy organ found in the prothoracic segment of larvae (caterpillars) of Swallowtail butterflies including Birdwings. This organ emits odorous compounds believed to be pheromones (insect hormones). Normally hidden, this forked structure can be everted when the caterpillar is threatened, and used to emit a foul-smelling secretion containing terpenes.

    Caterpillar with bright orange osmeterium (fleshy feelers) extruded.
    Osmeterium of a caterpillar.
    Close-up of osmeterium.

    C. INDUSTRIES INVOLVING TERPENES

    What are the industrial uses of terpenes?
    1. Essential oils are used as fragrances in perfumery.
    2. Essential oils are used in traditional and alternative medicines such as aromatherapy. 
    3. Synthetic variations and derivatives of natural terpenes and terpenoids also greatly expand the variety of aromas used in perfumery - lavender oil, rose oil, etc
    4. Natural rubber consists of polyisoprene in which the double bonds are cis
    5. Some plants produce a polyisoprene with trans double bonds, known as gutta-percha (getah perca).
    6. Research into terpenes has found that many of them possess qualities that make them ideal active ingredients as part of natural agricultural pesticides.
    What are the uses of terpenes in food?
    1. Essential oils are used widely as natural flavour additives for food. 
    2. Synthetic variations and derivatives of natural terpenes and terpenoids also greatly expand the variety of flavors used in food additives - peppermint oil, banana oil, etc.
    3. The linear triterpene squalene, is the major constituent of shark liver oil.
    4. Tetraterpenes include the acyclic lycopene found in tomatoes, and the bicyclic beta-carotenes found in carrots. 
    5. Norisoprenoids, such as the C13-norisoprenoids 3-oxo-α-ionol present in Muscat of Alexandria leaves and 7,8-dihydroionone derivatives, such as megastigmane-3,9-diol and 3-oxo-7,8-dihydro-α-ionol found in Shiraz leaves (both grapes in the species Vitis vinifera). These leaves are used to wrap food to make steamed dumplings in Mediterranean cuisine. They are healthy alternatives.


    D. HEALTH & MEDICAL ASPECTS OF TERPENES

    What are the health applications of terpenes?
    1. Vitamin A is an example of a terpene. 
    2. In addition to their roles as end-products in many organisms, terpenes are major biosynthetic building blocks within nearly every living creature. Steroids, for example, are derivatives of the triterpene squalene. Squalene is an intermediate in cholesterol synthesis.  
    3. Diterpenes form retinol, retinal, and phytol, which are known to be antimicrobial and antiinflammatory.
    4. Grapeseed oil is a therapeutic oil.
    5. Terpin hydrate is a derivative of turpentine. An expectorant and humectant, it is commonly used in the treatment of acute or chronic bronchitis and related conditions.
    6. Xanthophyll carotenoids are oxygenated forms of carotenoids. They are usually derived from alpha- and beta-carotene.

    Thursday 6 September 2012

    Functions of Lipids

    Why are there lipids in our body? What are they for? Are lipids important for our body's function? What functions do lipids have in our body?

    FUNCTIONS OF LIPIDS
    1. To serve as structural components of biological membranes.
    2. To provide as a readily available energy reserve, in the form of triglycerides.
    3. To serve as vitamin precursors, as vitamins and hormones.
    4. To provide as a readily available source of lipophilic bile acids for lipid solubilisation.

    Introduction to Lipids and Classification of Lipids

    INTRODUCTION TO LIPIDS
    What are lipids? Where can they be found? How do we recognise them? How are lipids classified? What are the components (building blocks) of lipids? What are the important lipids in medicine and healthy living?

    Biological molecules that are insoluble in aqueous solutions (water-based media) but are soluble in organic solvents are classified as LIPIDS. Lipids are a diverse group of biological substances which are made up of primarily non-polar functional groups. Lipids include oils (eg cooking oil, ghee, butter), waxes (candles, beeswax, car polish, earwax/tahi telinga), phospholipids (eg soy lecithin, used in creamers, used in instant milk, used in instant drinks), steroids (body builders and athletes consume them), sterols (eg cholesterol), terpenes (eg beta-carotene, the orange stuff in carrots, the red stuff in tomatoes) and many others. There are some 7-9 classes of lipids, depending on how we organise them.


    CLASSIFICATION OF LIPIDS

    1. Lipids are divided into 2 types based on their hydrolysis reactions/ability to be hydrolysed - Simple Lipids and Complex Lipids
    2. Simple Lipids are classed as Terpenes and Steroids & Sterols. Simple Lipids are not hydrolysable.
    3. Free Fatty Acids (FFA) are esterified to form larger molecules grouped as Complex Lipids. 
    4. Complex Lipids include Waxes, Triglycerides, Glycerophospholipids and Eicasanoids. Complex Lipids contain a component called Fatty Acids. All components of Complex Lipids are hydrolysable to yield the free components forms.
    5. Esterified complex lipids consist of 1 or more components which are hydrolysable into simple components.
    6. The common building block for most of the different types of lipids is the fatty acids.
    7. Fatty acids are composed of a chain on methylene groups (-CH2-) with a carboxyl functional group (-COOH) at one end. 
    8. Lipids differ mainly in the nature of the fatty acid chains.

    Wednesday 5 September 2012

    Staying In or Staying at Home

    A question that students and parents ask is whether students are allowed to stay at home when they have been accepted to first year medicine.

    The answer really depends on the students. The parents can advise and help out with understanding what the students will go through when they are new in medical school.

    Here are some of the things which students may want to discuss with their parents or guardians:

    1. Main reason to stay at home vs hostel
    2. Distance between medical school and home
    3. Travelling schedule
    4. Transportation mode and cost
    5. Traffic on the way to medical school and return
    6. Time-table for medical students (lectures begin at 8.30 a.m.)
    7. Hectic activities at medical school
    8. Benefits vs restricted activities of hostel life
    9. Study schedule and recreation
    10. Meeting others and building a healthy life together


    By the time Malaysian medical students enter first year university, they are 19 or 20 years old. At this age, most students are independent and can manage their lives well, even without their parents being around. Most will have experienced hostel life elsewhere before coming to USM medical school. So most students will find it easy and can settle down in the hostel in USM Kubang Kerian without much hassle. Kelantan life is simple and food is good and affordable. There are medical students, dental students and students from the health sciences to find and get to know. There is so much to learn about life here in USM in Kubang Kerian.

    Medical lectures take up the brunt of first year teaching and 2 lectures and scheduled every morning. The practical and other activities are in the afternoon. They are plenty of self-study periods each week. What students choose to do in their free time is entirely up to them. Lecturers will not direct students to do anything. But students should put the self-study periods to good use and not just extend their sleep hours. Revising lectures and looking through the notes collected from lectures will be a good activity during self-study. Looking up new words, a medical term, etc is highly encouraged. Visiting the library or studying in the library will also be good during self study.

    When students decide to stay at home rather than stay in the hostel, they have an added responsibility to attend all lectures as scheduled in the time-table. They will also need to know which lectures have been cancelled or postponed. They must not miss any scheduled or re-scheduled lectures. If a student decides to stay at home, he is entirely responsible for his actions. The mentor has only to note it for the student's records. If the student's studies become affected because he is commuting, then he is better of staying in the hostel and spend the 'travelling time' to study. Time is very precious in first year medicine. Do not waste it.

    Welcome to USM

    Welcome medical students to the 2012/2013 Academic Session.

    I have not met anyone yet. I met some of the dental students in the cafeteria at Desa Murni.

    I was busy editing my second book for publication this year. I have just finished that earlier this week. The 2 books that I have written this year are:

    1. Research on the Early Malay Doctors 1900-1957 Malaya and Singapore.
    2. Biography of the Early Malay Doctors 1900-1957 Malaya and Singapore.
    You can follow the blog here: http://theearlymalaydoctors.blogspot.com/

    I have a lecture next week on "History of Medicine". You can read up anything on that topic. There will not be any students' presentations this year. This is the second time that the academic session begins in September, just after Merdeka. As such we lose 1 day and that is the day for the students' presentations on History of Medicine. Since there will not be any students' presentations this year, it makes this lecture topic very dull. It used to be the best lecture in first year medicine and students really enjoyed their presentations. I enjoyed them too.

    I haven't prepared anything much for next week's lecture as I still prefer to have the students' presentation.