📌 POINTS TO PONDER

🔹 Systemic diseases associated with neutrophil disorders and periodontal diseases are diabetes mellitus, Papillon-Lefevre syndrome, Down syndrome, Chediak-Higashi syndrome, drug induced agranulocytosis, cyclic neutropenia and leukocyte adhesion deficiency.

🔹Periodontal diseases with neutrophil disorders areNUG, localized aggressive periodontitis and refractory periodontitis.

🔹Chemokine paralysis: P. gingivalis impedes transepithelial migration of neutrophils and prevent epithelial cells from secreting IL-8 in response to bacterial challenge. This property may contribute to the virulence of P. gingivalis by interfering with the host immune response.

📌 VIVA VOCE

Q1. Which is the smallest MMP?

Ans. Matrilysin is the smallest MMP.

Q2. What are resolvins?

Ans. Resolvins are lipid mediators that are induced endogenously during the resolution phase of inflammation. These are biosynthesized from the precursor essential-3 polyunsaturated fatty acids:  eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) derived from the diet.

Q3. What are gingipains?

Ans. They are trypsin like proteases which are virulence factors of Porphyromonas gingivalis.

Q4. What is Chemokine paralysis?

Ans. Porphyromonas gingivalis obstructs the transepithelial migration of neutrophils and inhibits IL-8 secretion from epithelial cells against bacterial challenge. Thus, P.gingivalis contributes to the virulence by interfering with the host immune response.

Q5. What is periodontain?

Ans. Porphyromonas gingivalis has potential virulence factor through production of periodontain, an alpha-1 proteinase inhibitor of human neutrophil elastase.

Q6. How do the host tissue damages occur during host microbial interaction?

Ans. A. Through metabolic by-products of microbes: Ammonia, fatty acid, peptides and enzymes (collagenase, keratinase, trypsin-like enzyme, fibronectin-degrading enzyme).

B. Through the release of biologic mediators from host tissue cells: IL-1, tumor necrosis factor, and prostaglandins.

Q7. What are the virulence factors?

Ans. The properties of a microorganism that enables it to cause disease are referred to as virulence factors.

Q8. What are the various virulence factors of A. actinomycetemcomitans? 

Ans. Collagenase, cytotoxin, leukotoxin, bacteriocin, endotoxin, Fc binding protein, invasins, immunosuppressive factors, adhesins and chemotaxis inhibitor.

Q9. What are prostaglandins?

Ans. Prostaglandins are arachidonic acid derivatives synthesized under the action of cyclooxygenases [cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX- 2)] isoenzymes.

Q10. What are lipoxins?

Ans. Lipoxins are the natural proresolving molecules synthesized from endogenous fatty acids via COX-2/ LOX pathways.

📌 MULTIPLE CHOICE QUESTIONS MCQs

💡Microorganisms having the ability to directly invade host tissue cells:

A. Aggregatibacter actinomycetemcomitans

B. P. gingivalis

C. F. nucleatum

D. Treponema denticola

E. All of the above

Answer : E

💡 P. gingivalis has the ability to inhibit the production of:

A. IL-1 by epithelial cells

B. IL-8 by epithelial cells

C. IL-6 by epithelial cells

D. None of the above

Answer :B

💡 The smallest Matrix metalloproteinases (MMPs) is:

A. Matrilysin (MMP – 7)

B.Gelatinase – B (MMP – 9)

C. Enamelysin (MMP – 20)

D. Stromelysin – 1 (MMP – 3

Answer : A

💡 The sequence of stages related to the pathogenesis of periodontal diseases are:

1. Adhesion and colonization

2. Host tissue invasion

3. Bacterial evasion of host defense mechanisms

4. Host tissue destruction

5.Tissue healing

A. 1, 2, 3, 4, 5

B. 1, 3, 2, 4, 5

C.1, 4, 3, 5, 2

D. 3, 1, 2, 4, 5

Answer : A