Etiology, Biology

Assignment Help:

M protein of rheumatogenic GAS has distinct structural characteristics that are akin to human heart tissue, particularly sarcolemmal membrane proteins and cardiac myosin. The major factors that lead to risk of ARF are the severity of the immune response to GAS pharyngitis and persistence of GAS organisms during convalescence. A very small proportion (0.3-3 per cent) of patients suffering from GAS throat infection ultimately develop ARF and this along with a familial predisposition of ARF points to a genetic susceptibility. However, in our Indian patients a genetic linkage to HLA DR3 in patients, with ARF has been demonstrated. For confirmation of the initial diagnosis of acute rheumatic fever, evidence of prior GAS infection is required. Several rapid GAS antigen tests are available. Majority of these tests has a high degree of specificity but low level of sensitivity in clinical practice.

However, it must be stressed that a negative test does not rule out the GAS infection in the throat. At the same time in presence of a positive antigen test and positive throat culture, it is difficult to distinguish between a recent infection which can be associated with ARF and chronic carrier of GAS infection with ARF. Elevated or rising ASO titres (> 250Todd units in adults and >333 Todd units in children) are more reliable evidence of recent GAS infection than a positive culture or positive rapid antigen test and such titres are also significant for diagnosis.


Related Discussions:- Etiology

Biological challenges, Biology is becoming a more quantitative science, a t...

Biology is becoming a more quantitative science, a trend that has motivated and been recently spurred by advances in computing power and data-gathering technologies. Nowhere is th

Vertebrate heart, VERTEBR A T E HEART Heart = Cardia. Most import...

VERTEBR A T E HEART Heart = Cardia. Most important organ of body. Main function is to pump the blood. Study of heart is cardiology. In heart auricles and ventricles pr

What is fehling's test - reduction tests, What is Fehling's test - Reductio...

What is Fehling's test - Reduction Tests? This test is answered by all reducing sugars which possess a free aldehyde or ketone group. All monosaccharides possess a free aldehyd

Explain functional property of waterbinding - whey protein, Explain Functi...

Explain Functional property of  WaterBinding/ Hydration Mode of action  Proteins can help reduce formula costs as the proteins hold additional water. Food system

Natriuretic peptides, There are three natriuretic peptides-atrial (ANP) sto...

There are three natriuretic peptides-atrial (ANP) stored mainly in the atrium, brain (BNP) stored mainly in the ventricular myocardium and C-natriuretic peptide (CNP) located prima

Bovine spongiform encephalopathy (bse), B o vi n e spongiform encephalo...

B o vi n e spongiform encephalopathy (BSE) Bovine spongiform encephalopathy (BSE) is a transmissible, neurodegenerative, fatal brain disease of cattle characterized by post

What is the root pressure, What is the root pressure? The Root pressure...

What is the root pressure? The Root pressure is the pressure that forces water from the soil to be absorbed by xylem of the root. It is because of the osmotic gradient between

Gills - respiration, Gills - Respiration Gills are highly vascularise...

Gills - Respiration Gills are highly vascularised extensions of gas exchange membranes. The simple type may be extension of the body surface as in sea-slugs, sea stars and ma

Where do the two neuronal pathways diverge, Where do the two neuronal pathw...

Where do the two neuronal pathways diverge For both the neuronal pathways i.e. light reflex and near reflex the efferent fibres go to are 3rd cranial nerve and then to sphinct

Fast response - biological responses, Fast Response - Biological Responses ...

Fast Response - Biological Responses Some of the fast responses are discussed below: It was found that when mung bean root tips were kept in a specific solution (contain

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd