Adichunchanagiri

Institute of Medical

Sciences

Chief Patron

Paramapoojya

Sri Sri Sri

Nirmalanandanatha

Mahaswamiji

Chief Advisor

Dr Shivaramu M.G.

Principal A.I.M.S.

Chief Editor

Dr Aliya Nusrath.

Professor & Head

Dept. of Biochemistry

Editorial Board

Dr. Rajeshwari A.

Assoc. Professor

Sri. Somashekar G.N.

Asst. Professor

Dr. Chikkanna D.

Asst. Professor

Dr Maithri C.M.

Asst. Professor

Dr Asha Rani N.

Asst. Professor

Mrs Rafiya Begum

Tutor

Members

Dr. Prathibha K.

Tutor cum PG

Dr Namitha D.

Tutor cum PG

Contact information:

biomedaims@gmail.com

Biochemistry - Medicine at molecular level

Biomed Dept of Biochemistry

___________________________________________________

News letter VOLUME 1 ISSUE 4 JANUARY 2014

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From Editor’s Desk Greetings

With great pleasure and pride we are releasing the fourth

issue of Biomed.

Cardiovascular disease (CVD) is the leading cause of

morbidity and mortality globally. Even though genetic factor

plays a major role in causation of the disease, modifying the risk

factors may prevent early onset. Screening for the disease, early

diagnosis and timely intervention may reduces the morbidity and

mortality events of CVD. In view of this we have focused on

current new markers in diagnostics of CVD in this issue and also

are conducting a state level CME on “Biochemical Aspects of

Cardiovascular Diseases –An Update”

Dept staff

First Row (From left to right): Dr Chikkanna, Dr Aliya Nusrath, Dr Rajeshwari A and Sri Somashekhar

Second Row (From left to right): Dr Asha Rani, Mrs Rafiya

Begum, Dr Prathibha K and Dr Namitha D Third Row (From left to right): Sri Krishne Gowda, Sri Yateesh,

Sri Shankare Gowda and Sri Mahalinge Gowda,

D-Dimer

D-dimer a high molecular weight fibrinogen derivative derived from the degradation of cross linked

fibrin. Systemic values of D-dimer are the index of fibrin turnover in the circulation and a single

measurement may be adequate to assess the fibrinolytic status. Systemic D-dimer values are raised in variety

of clinical conditions and D-dimer testing provides cost effective diagnostic strategies. The D-dimer antigen

is a unique marker of fibrin degradation is formed by the sequential action of enzymes, thrombin, factor

XIIIa and plasmin. D-dimer measurements serves as a (1) clinically useful marker for exclusion of venous

thromboembolism (VTE) and evaluate the risk of VTE recurrence. (2) To diagnosis and monitoring of

coagulation activation in disseminated coagulation (DIC). (3) Deep vein thrombosis (DVT) and/or

pulmonary embolism (PE).

Impaired fibrinolytic activity is an independent risk factor of CHD or its recurrence. Myocardial

infarction is higher in patients having high levels of biochemical markers of thrombus formation such as

fibrinogen, prothrombin fragment, thrombin-antithrombin complex and fibrin peptides. D-dimer serves as

the global marker of ongoing coagulation with fibrinolysis. D-dimer level is independent of other

cardiovascular risk factors. It’s level increases in patients with unstable angina pectoris, acute myocardial

infarction and early marker of coronary ischemia in patients with chest pain. D-dimer assays by approved

ELISA and latex turbidimetric methods with excellent sensitivity are available for the exclusion of VTE and

are used worldwide for this purpose. Dr. Rajeshwari A Assoc. Professor, Biochemistry

LIPOPROTEIN(a) [Lp(a)]

Lipoproteins are the particles composed of proteins (apolipoproteins), phospholipids, triglycerides,

cholesterol and transport cholesterol and triglycerides in the blood stream. Lp(a) is a lipoprotein rich in

cholesterol and it differs from LDL as it contains apolipoprotein (a) (apo(a) attached to apo B-100 by a

disulphide bond). In adults, plasma levels of Lp(a) vary widely, ranging from 0.2 – 250 mg/dL. Lp(a) levels

less than 30 mg/dL are considered normal.

The structure of Lp(a) is similar to plasminogen and tPA (tissue plasminogen activator) and it

competes with plasminogen for its binding site, leading to reduced fibrinolysis. Lp(a) stimulates secretion

of PAI-1, it leads to thrombogenesis. Lp(a) penetrate the inner layer of the arterial wall and accumulate at

sites for atherosclerotic plaque formation than LDL. Lp(a) transports oxidized phospholipids whose plasma

levels are strongly correlated with the severity of coronary artery disease. These Lp(a) associated oxidized

phospholipids also possess pro-inflammatory activity. This may be mechanisms behind the involvement of

Lp(a) in heart attack and stroke.

Lp(a) is mainly genetically determined and therefore refractory to lifestyle intervention. Dietary

changes, exercise and weight loss have not been shown to lower Lp (a). Agents that lowers Lp(a) are Niacin

(nicotinic acid), aspirin, l-carnitine, ascorbic acid/L-lysine, angiotensin converting enzyme inhibitors,

calcium antagonists, androgens . Oestrogen replacement therapy in women also lowers Lp(a). Lowering of

plasma Lp(a) levels is also seen in individuals on diets rich in saturated fat (a palm oil enriched diet). There

is a significant decrease in Lp(a) levels in individuals whose diets were supplemented with almonds.

Lp(a) should be measured in high risk individuals such as those with premature CVD, familial

hypercholesterolemia, family history of premature CVD and/or elevated Lp(a), and individuals with

recurrent CVD despite statin therapy. Dr. Namitha D, Postgraduate, Biochemistry

Laboratory Medicine is the cornerstone of Health Care System

Diagnostic utility of Heart type –Fatty Acid Binding Protein (H-FABP)

Fatty Acid Binding Protein (H-FABP) is a small cytoplasmic protein abundantly expressed in tissues

with an active fatty acid metabolism, such as the heart and liver with their primary function being the

facilitation of intracellular long-chain fatty acid transport. Nine distinct types of the FABP family have been

identified and H-FABP also known as mammary-derived growth inhibitor with molecular weight of 15 kDa

is being the most widely studied, as they are found in abundance in the cardiomyocytes. It is encoded by

the FABP3 gene in humans.

H-FABP is a highly sensitive early rise biomarker across the full spectrum of acute coronary

syndrome (ACS), detectable as early as 30 minutes following the onset of an ischemic episode. They are

released very rapidly following Acute Myocardial Infarction (AMI) due to their low molecular weight and

cytoplasmic location. It peaks at approximately 6-8 hours and return to normal within 24-30 hours. It is

approximately 15-20 times more cardiac specific than Myoglobin, hence making it a more efficacious

biomarker for myocardial injury. A secondary benefit of the H-FABP is that it can be used as a biomarker

for reinfarction since it returns to baseline concentrations rapidly. It is a very stable protein in-vitro, as many

studies have shown that serum/ plasma samples can be subjected to up to 8 freeze/thaw cycles without the

loss of immuno-reactivity. It is a highly effective biomarker in the diagnosis and management of patients

with suspected Acute Coronary Syndrome (ACS), especially when used in combination with Troponin (TnT

or TnI).

Due to its early release mechanism, H-FABP has recently been demonstrated to be a superior

independent predictor of outcome in post-operative mortality, ventricular dysfunction, and pulmonary

embolism and also helps to discriminate between graft failure with massive tissue necrosis and ischemia

reperfusion injury within 24 hrs after coronary artery bypass grafting surgery than troponin & CK-MB.

Dr. N. Asha Rani, Assistant Professor, Biochemistry

Serum Paraoxonase: A Novel antioxidant

Serum paraoxonase/arylesterase 1 (PON1) [EC 3.1.8.1]) also known as aromatic esterase 1 or serum

aryldialkylphosphatase 1 is an enzyme that in humans is encoded by the PON1 gene. Paraoxonase 1 has

esterase and more specifically paraoxonase activity.

PON1 is responsible for hydrolysing organophosphate pesticides and nerve gases. Polymorphisms in

the PON1 gene significantly affect the catalytic ability of the enzyme.

PON1 (paraoxonase 1) is also a major anti-atherosclerotic component of high-density lipoprotein (HDL).

The PON1 gene is activated by PPAR-γ, which increases synthesis and release of paraoxonase 1 enzyme

from the liver, reducing atherosclerosis.

Several epidemiological studies have shown serum HDL concentration to be inversely related to the

risk of developing atherosclerosis. The oxidation of LDL in the artery wall have a central role in

atherogenesis. HDL prevents the oxidative modification of LDL by enzymatic mechanism. Paraoxonase

isolated from human HDL in liposomes has also been shown to decrease the susceptibility of LDL to lipid

peroxidation. This suggests a potential role for paraoxonase in the detoxification of lipid peroxides and

suggests that individuals with a low paraoxonase activity phenotype may have a greater risk of developing a

disease such as atherosclerosis, which may involve lipid peroxidation.

Populations with insulin-dependent diabetes mellitus show marked reductions in serum paraoxonase

activity without having a significantly lower HDL cholesterol concentration. Therefore, the decrease in

activity of serum paraoxonase associated with diabetes may play a role in the increased incidence of

premature atherosclerosis associated with this disease. Furthermore, it may influence susceptibility to

neuropathy, in which lipid peroxidation has been implicated in pathogenesis.

Dr. Prathibha K, Postgraduate, Biochemistry

Hearty congratulations To Dr. PRATHIBHA.K, Post graduate, for securing first prize in student category for

presenting an oral paper entitled “Study of CRP level and lipid profile in Psoriasis” at

International conference (IMSACON 2013) of International medical sciences academy in

association with Rajarajeshwari Medical College Bangalore on 5th- 6

th October 2013.

Fun and Learn

Biomed Crossword (Crossword on Lipids)

1 2 3 4

5 6

7

8 9

10 11 12 13

14 15

16 17

18

19 20

21 22

Across 5. A solid alcohol (6)

6. An important component of phospholipid as well as

neurotransmitter (7)

7. An important PUFA (9)

8. A lipid in blood clotting (8)

11. A juice rich in cholesterol

14. A molecule which is repository of apolipoproteins (3)

16. A heterogeneous group of hydrophobic compounds (5)

18. An amphipathic vehicle for exogenous compounds (9)

19. An acid which is preferred fuel of heart (5)

20. Major stored fuel (3)

(Abbreviation)

21. A lipid secreted by cells which

acts as a strong aggregator of same

cells (3) (Abbreviation)

22. The little rascal (3)

(Abbreviation)

Down 1. Endogenously synthesized

triglyceride rich molecule (4)

2. A keto group containing lipid

derivative (7)

3. An alcohol of lipid (8)

4. A resistance to action of this

hormone leads to obesity (6)

7. Most common lipid of plasma

membranes (8)

9. oxidation of this molecule

generates net 106 ATP (9)

10. A cholesterol derivative with

three hydroxyl groups (7)

12. Also acts as part of anchorage of

proteins in membrane structure (8)

13. Accumulation of GM2 occurs in

this disease (3,5)

15. A hydrolytic enzyme of lipids

secreted by many tissues (6)

17. Major product of lipid digestion

(4)

19. Common term for obesity (3)

By Dr Aliya Nusrath

Prof and HOD, Biochemistry. Answers will be given in next issue {Answers of previous issue Across: 1. Hunters 7. Chorea 8. Goiter 11.

Cori 12. Diabetes 16. Pellegra 18. NIDDM 20. SIDS 22. Prion 23. MSUD 24. Taysachs

Down: 2. Edward 3. SCID 4. Gout 5. Hers

6. Homocystinuria 9. Tauri’s 10. STD 13. Scurvy 14. Slys 15. Tangier 16. PEM

17. Refsum’s 19. Fish 21. PKU