Basic concepts, immunity and inflammation

Inflammation is an observable alteration in the tissues, with changes in vascular permeability and dilation. Leukocytes, the white blood cells, control all three stages of inflammation.
3 Stages of Inflammation are:

1.Immediate

2.Acute

3.Chronic

 Cardinal Signs of Inflammation:

Erythema

Oedema

Heat

Pain

Loss of function

• Immediate inflammation: main cell Resident Leukocytes*.
• Acute Inflammation: main cell is neutrophil.
• Chronic inflammation: main cell is lymphocyte and macrophage.

*Resident Leukocytes are:

• mast cells
• peripheral dendritic cells
• dermal dendrocytes  ( histiocytes)

Cells of Immunity And Inflammation

1 Mast Cells

• Immediate inflammation
• receptors for IgE and IgG
• Express toll like receptors
• Contain lysosomes
• Cause anaphylaxis

2 Dermal Dendrocytes

•  Also called Histiocytes
• Cause immediate inflammation
• Collagen associated dendritic cells of myeloid origin
• Express MHC class II molecules
• Express matrix metalloproteinases and cause periodontal tissue destruction

3 Peripheral Dendritic cells

• They are leukocytes with cytoplasmic projections or dentrites
• Langerhans cells are dendritic cells
• Ingest antigen and transfer to lymph nodes

4 Neutrophils

• Phagocytic leukocytes
• Differentiate in the bone marrow(14 days)
• Also called Polymorphonuclear Leukocytes
• Predominant leukocyte
• 2/3rd of the blood leukocyte
• 4000-8000 cells /mm3 
• Receptors for IgG

5 Monocytes/ macrophages

• Phagocytic leukocyte
• Monocytes differentiate in the tissues
• Monocytes are macrophages when they leave the blood
• 22 micrometers
• Present antigen to T cells
• Macrophages and Lymphocytes orchestrate the chronic immune response

6 Lymphocytes

They are of 3 types:

1.T cells

2.B cells

3.Natural Killer cells

1. T cells

•  Inactive in the blood
•  Small( 8-10 micrometer)
• Major histocompatibility complex
• Recognise T cell antigen receptor
• Two types: CD4+ T cells and CD8+ T cells

2. B cells

• Control extracelleular antigens such as bacteria, fungal, yeast and virions.
• 8-10 micrometer.
• Express IgM
•  After antigen exposure B cells differentiate to plasma cells
• B cells also form memory B cells in the presence of T cells, which after secondary antigen exposure convert to plasma cells.

3 Natural Killer Cells

• Kill tumor and virally affected cells
• Have killer inhibitory receptors and killer activating receptors
• Largest of all leukocytes( 15micrometer ).
• Recognize antigens associated with MHC class I molecules.

Complement (C)

• Has 30 membrane associated cell receptors and soluble serum glycoproteins
• Soluble component is 5%.
• C3 is the most important.
• Enables endothelium and leukocytes to recognize and bind foreign antigen

Transendothelial Migration

• It is the interaction between the leukocyte and endothelium to exit blood and enter tissues.
• Inflammation occurs due to interaction between complement, resident leukocytes and recruited inflammatory leukocytes.
• Neutrophils and monocytes spend less than 12 hrs in blood.
• B & T cells :30 mins(Lymphyocytic recirculation: these cells require influence of lymphoid organs. They exit the blood, enter lymphatics and lymphoid organs and then again enter the blood)

Steps in endothelial migration

Step 1: Rolling

• L-selectin is expressed(non enzymatic carbohydrate binding protein).
• Leukocytes are the main cells.

Step 2: Insult to the epithelium

Step 3:Signalling the endothelium

• Inflammatory signals( Interleukin -1beta , TNF-alpha) from mast cells in tissues.
• Mast cells recruit neutrophils against bacteria and respond to anaphylatoxins such as C3a and C5a.

Step 4: Increased rolling

•  IL-1beta, TNF-alpha and C5a stimulate endothelial cells to express P-selectin and E-selectin

Step 5: Signal for rolling arrest

• Chemokines are signals for leukocytes to exit blood
• Chemokines are signals for rolling arrest.

Step 6: Strong Adhesion

• L-selectin shed
• LFA-1 expressed
• LFA interacts with ICAM-2 on the endothelium.

Step 7: Zipper

• CD31 is the platelet endothelial cell adhesion molecule.
• CD31 is a 130 kD transmembrane glycoprotein present at the intercellular borders of endothelial cells and leukocytes.
• It is a homophilic molecule.
• CD31 on endothelium binds to CD31 on leukocytes and guides them to the boundaries between endothelial cells.
• This zipper effect minimizes the leakage of fluid.

Leukocyte Functions

1 Chemotaxis

• It is the migration of leukocyte to the site of insult.
• Receptors for chemotaxis are G-protein coupled family
• Chemotaxins derived from bacteria are: formyl methionyl peptides.

2 Phagocytosis

• These cells ingest particles of a size visible under light microscope.
• Neutrophils and macrophages are involved
• Phagosome is containment of pathogen in a membrane delimited structure.
• Opsonization is coating of pathogen with ligands
• There are two types of killings: 

1. Oxidative mechanism

•           It occurs in the presence of oxygen
•           The mechanism is oxidation -reduction potential which is -160mv(at or above).
•           Neutrophils form superoxide anion using NADPH oxidase system
•           Superoxide anion forms hydrogen peroxide.
•           Hydrogen Peroxide is s substrate for myeloperoxidase.
•           In the presence of myeloperoxidase, hydrogen peroxidase with chloride ions forms                      hypochlorous acid, which is an antimicrobial agent.
•           Deficiencies of NADPH causes chronic granulomatous disease.

   2.  Non Oxidative Killing

•          Phagosome-Lysosome fusion happens which is called phagolysosome.
•          There are two types of lysosomes in neutrophils:      
•             Specific Granules: extracellular and intraphagolysosomal secretion.         
•              Azurophil granules: intraphagolysosomal secretion
•          Specific granules have lysozyme(bactericidal and fungicidal) and lactoferrin(bacteriostatic  compound).
•          Non oxidative killing mechanism is important in periodontal diseases because of the highly anerobic condition of the subgingival environment.

3 Antigen Processing and presentation.

• MHC is present on the locus of the short arm of the chromosome 6.
• MHC encodes molecules including Class I, II and III which are involved in antigen uptake , processing and presentation.
• MHC class I presents intracellular antigens to CD8+ T cells and NK cells
• MHC class III include complement factors B, C2 and C4.
• Antigen presenting cells present antigens from extracellular sources.
• Antigen presenting cells are peripheral DC's , monocyte derivatives and B cells.
• APCs present antigen to CD4+ T cells in association with MHC class III.
• MHC exhibit pleomorphism.
• MHC are significant in transplantation.
• Co-stimulation (second signal): reaffirms T cell has recognised an antigen.

       Functions of Co-stimulation:

1. Makes T cells resistant to apoptosis.
2. upregulates growth factor receptors.
3. Decreased amount of time needed to trigger T cells( amplification).

• Toll (receptor molecule ) first identified in fruit flies.
• Toll like receptors in humans are stimulated by bacterial components like LPS.

Specific Immune Responses

• In protracted chronic inflammation.
• Requires lymphocytes, which uses two types of receptors : the B cell antigen receptor and the T cell antigen receptor.
• Steps:

1. Clonal selection: selection of lymphocytes that bear receptors(BCR/TCR) recognizing specific antigen.
2. Clonal expansion: proliferation of those lymphocytes.
3. Clonal contraction: death of effector lymphocytes.
4. Memory: maintainance of specific clone cells that bear receptors.

T cell responses

• T cell interacts with APC.
• T cell antigen recognition is a function of TCR.
• T cells express 3000-50,000 TCRs on the surface.
• MHC class I and II present antigen to T cells.
• CD-1 presents antigen to NK cells.
• CD3 transductory apparatus activates TCR.
• CD8 and CD4 are T cell co receptors.
• Scanning: Time dependent interaction of TCR with antigen.
• Scanning that triggers T cell activation is serial triggering.
• Immunophilins diminish action of calcinurin.
• Immunosuppressants like cyclosporin A and tacrolimus bind and activate immunophilins resulting in immunosuppressive effects.

B cell responses and antibodies

• B cells produce immunoglobulins.
• Immunoglobulin that binds to antigen is called antibody.
• 9  isotypes in humans: IgM, IgD, IgG1, IgG2, IgG3, IgG4, IgA1, IgA2, IgE.
• Maximum production: IgA.
• BCR binds antigen with high affinity in contrast to TCR.
• T- independent- B cell antibody response: B cells respond to certain antigens in the absence of antigens.
• B cell responses don't mature, they don't enter the memory pathway.
• Mutation in gene for Gp39 lead to X- linked hyperimmunoglobulinemia M syndrome: deficiency of immunoglobulin isotypes.
•  IgM : primary response Immunoglobulin
•  IgE, IgG, IgA: Secondary response immunoglobulins( by memory B cells).

Hello readers. I am writing the basic concepts of immunity and inflammation. I hope it is helpful to the students and any other reader. I have tried to make it as simple as possible.

You can always let me know if any changes are required . Thank you.

     Reference: Carranza's Clinical periodontology.    

Immunity

Immunity is the resistance exhibited by the host against any foreign antigen including microorganisms.

2 Types of immunity

• Innate
• Acquired

1.Innate Immunity

It is the resistance which the individual possesses by birth. It is not dependent on prior contact with antigens.

Types of innate immunity

• Species immunity: Resistance to a pathogen shown by all members of a particular species .Eg B.anthracis infects humans but not chickens.
• Racial immunity; Different races exhibit resistance or susceptibility to infections.
• Individual immunity: Resistance to infection varies with different individuals of the same race and species .

Factors influencing Innate immunity

• Age: Children and elderly have a higher susceptibility to infections.
• Hormones: Hormonal disorders like diabetes mellitus, hypothyroidism enhance susceptibility to infections.
• Nutrition :Malnutrition predisposes to infections.

Mechanism of Innate immunity

1. Epithelial surfaces:

• Skin: It acts as a mechanical barrier. It also provides bactericidal secretions which are present in the sweat and sebaceous glands.
• Respiratory tract: The inhaled particles are trapped in the mucous secretions of the respiratory tract. Cilia propels the particles towards the pharynx. Cough is an important defence mechanism.
• Intestinal tract: Saliva has an inhibitory effect on many microorganisms. Microorganisms that reach the stomach are destroyed by the acidic pH of the stomach. The intestinal flora prevent the growth and colonization of harmful microorganisms.
• Conjunctiva:Lysosyme present in the tears has a bactericidal action. Tears flush away bacteria and dust particles from the eyes.
• The genitourinary tract: Urine flushes away bacteria from the urinary tract. The acidic pH of vaginal secretions and the semen in males has antibacterial substances.

2. Antibacterial substances: Properdin, complement, lysozyme, betalysin, basic polypeptides,(leukins from leukocytes and plakins from platelets. Interferons have antiviral activity.

3. Cellular factors: When an infective agent invades the tissues, phagocytes accumulate at the site and cause an exudative inflammatory reaction. hagocytic action is of 4 types

• Chemotaxis: Phagocytes reach thee site of infection attracted by chemotactic substances.
• Attachment: The infective agent gets attached to the phagocytic membrane.
• Ingestion: Phagocyte engulfs the infective agent(phagosome).
• Intracellular killing:Phagolysosome destroys most bacteria by ingestion. Some bacteria are not killed even after ingestion and they multiply within the phagolysosome and produce disease eg: M.tuberculosis and M.leprae.

4. Inflammation: Inflammation occurs as a result of tissue injury or irritation and is initiated by the entry of pathogens, It is a non specific defence mechanism. Inflammation leads to vasodilation, increased vascular permeability and cellular infiltration. Microorganisms are phagocytosed and destroyed. A fibrin barrier is laid to wall off the site of infection.

5.Fever: A rise in body temperature destroys the microorganisms. Fever stimulates the production of interferon which is helpful in viral infections.

6. Acute phase proteins: After an infection or injury, there is an increase in the plasma concentration of acute phase proteins. These proteins activate the alternate pathway of the complement.

2.Acquired immunity.

The resistance acquired by the individual during life is called acquired immunity.

It is of 2 types:

Active

Passive

1. Active:

• Natural: It is acquires from clinical or subclinical infections. Such immunity is long lasting. Eg people recovering from small pox.
• Artificial : It is produced by vaccination. The vaccines have live, attenuated, killed microorganisms or their antigens or toxoids. Toxoids are immunogenic not toxigenic.

Vaccines are: Live vaccines eg BCG for tuberculosis

                      Killed vaccines eg Hepatitis B vaccine

                      Bacterial products eg Tetanus toxoid for tetanus.

Mechanism: 

Humoral immunity: It is antibody mediated immunity. The plasma cells produce antibodies. The antibodies cause lysis or neutralize the toxins of the antigens.

Cell mediated immunity: It is T- cell mediated immunity. The T cells are important in resistance to chronic bacterial(tuberculosis) and viral(Herpes simplex) infections.

2. Passive immunity:

Passive immunity is induced in the body by preformed antibodies. It is short lasting.

It is of 2 types:

Natural: It is transferred from mother to foetus through transplacental maternal antibodies IgG and to infant through milk.

Artificial: It is through administration of antibodies parenterally.The agents used are hyperimmune sera of animal or human origin, convalescent sera and pooled human gammaglobulin. Hyperimmune sera like Antitetanus serum is prepared by  injecting doses of tetanus toxoid to horses and bleeding them to obtain the serum. Convalescent sera( sera of patients recovering from infectious diseases) is used for the passive immunization against measles and rubella. Pooled human gammaglobulin is used against the passive immunization against viral infections like hepatitis A.

                                                               ---------------------------

Foods harmful for the mouth

Everyone knows that a high sugar diet is not good for teeth. But there are certain foods  other than a high sugar diet that are harmful for your teeth. Here is a list

1. Sugar

 Candies, chocolates or any other foods having high amount of sugar content in them are harmful when consumed in large and regular amounts. If you don't brush and floss regularly, then the foods with stick to the teeth. This will cause tooth decay and eventually loss of teeth.

2. Aerated drinks

 The acid present in the aerated drinks causes erosion of the enamel over time. The acid slowly dissolves the enamel and exposes the dentin when the consumption is very high and regular.

3.Ice

Ice is just water and without any calories. Then why is it harmful? Chewing hard ice can lead to cracks in enamel. This causes sensitivity.  Once the teeth are sensitive, you cannot enjoy your meals like you did before.

4.Citrus fruits

Check on your consumption of citrus fruits. Although citrus fruits are good for your health but if you consume  in large amounts then it can lead to dental issues. The citric acid in the fruits dissolves the enamel and leads to erosion of enamel. This exposes the dentin and can lead to cavity formation at a faster rate.

5.Beverages

Tea and coffee are beneficial but over consumption can lead to staining of the teeth overtime.  Brown or black stains appear on the teeth which make the teeth look unappealing. Caffeinated drinks dry out your mouth. Make sure to drink lots of water.

6.Sticky foods

When people choose a healthy snack, dried fruits are a priority. Many dried fruits are sticky. Sticky food damage the teeth because they stay on the teeth longer as well as on areas where tooth brush cannot clean. Make sure to brush and floss regularly.

7.Starchy foods

Crunchy potato chips are a popular snack. Potato chips are starchy and so is bread. They tend to stick to your teeth and cause cavities. Brush and floss properly after consuming such foods.

8. Alcohol

Regular and heavy consumption of alcohol is harmful. It dries the mouth which leads to cavity formation and bad breath. Limit your alcohol consumption and drink lots of water.

9 ways for a photogenic smile

The wedding is near and everything is perfect yet not perfect. Want a captivating smile? Don't worry the problem is solved. The solution is not only for the wedding but for many years to come.
Here are solutions to your problem...

Cosmetic Dentistry is a part of dentistry that improves the appearance of teeth, gums, lips. It primarily focuses on the smile designing by focusing on the color, shape, size and alignment of teeth as well as gums and lips.
1. Teeth whitening
Teeth whitening(bleaching) is the easiest and the most common procedure to improve the smile as well as to whiten the teeth. If the teeth are yellow, stained due to tea, coffee then tooth whitening is an apt procedure for such cases.

2. Veneers
Veneer is a thin layer of material placed over the tooth. It improves the aesthetics of the tooth/ teeth as well as protects the teeth from damage. It is used in cases with discoloured, malformed, enamel hypoplasia, fluorosis, erosion or to modify the shape of the tooth.

3. Crowns/ Bridges
Crowns(caps) are either made of metal, porcelain fused with metal (PFM)or zirconia. Metal, PFM or zirconia is used for the posterior teeth, depending upon the budget. For anterior teeth only PFM or zirconia is used , depending upon the budget. They improve the aesthetic as well as restore the function of the teeth. It is used to improve the esthetics of unsightly teeth, restore a badly broken tooth, root canal treated tooth, single or multiple missing teeth(bridge), a big cavity restoration, over a dental implant.

4. Botox and fillers

We cannot ignore the whole face and just make the teeth look good. It is helpful in removing wrinkles on the forehead, the eyes. It is also useful for people who have a high lip line, lip augmentation and even for facial pain.

5. Braces
Dental braces are used to align crooked teeth and many other issues like overbite, underbite, cross bite.They are of many types. The traditional ones are the metal braces. Then there are ceramic, monocrystalline ceramic and Invisalign. Invisalign is the latest. You can wear it to your office, to meeting , in the public to parties and no one will notice. Dentist appointments are also less.

                            



6.Implant
A dental implant is used to replace a single or multiple missing teeth. It consists of a screw which is  made up of titanium. It is placed in the bone surgically. It cannot be removed from the mouth. Success or failure depends on the health of the patient, the drugs that effect, health of the tissues receiving the implant. If the implant procedure is a success then it is the best solution for missing teeth.

7.Composite
Dental composite is used as a restorative material or adhesive. It is a cheap procedure as compared to the above mentioned procedures. It is used to correct cavities, minor gaps between front teeth, as veneers.

8. Gum procedures
Sometimes there is no issue with the teeth, instead the gums are not symmetrical.There are cosmetic gum surgeries to make the gums more symmetrical.

9. Reshaping of teeth
Tooth reshaping involves correction of teeth by removal of parts enamel to improve the appearance. It may be used to correct minor chipping or tooth size discrepancy .

9 yoga poses for PCOS

PCOS or PCOD is Polycystic Ovary Syndrome ,a hormonal disorder affecting women of reproductive age. According to WHO , PCOS has affected 116 million women worldwide.
This syndrome has cysts in the ovaries along with high levels of male hormones and irregular menstrual cycle.

Here are some beneficial yoga poses that will help in PCOS

1.Chakki Chalan asana/ Milk churning pose

Duration : 5-10 rounds clockwise and then 5-10 rounds anticlockwise
Benefits:

• Everyday practice helps to relieve stress associated with PCOS.
• Reduces belly fat.

Contraindications:

• Should not be practiced during slipped disc conditions. 

2. Hala asana/ Plough pose

Duration: Hold on to the pose for 30 seconds to 3 minutes.

Benefits:

• Stimulates the reproductive organs
• Relieves symptoms of menopause.
• Beneficial for Infertility

Contraindications:

• Diarrhoea
• Menstruation
• Neck injury
• Asthama
• High blood pressure
• Pregnancy

3. Setubandha asana/Bridge pose

Duration: Hold on for 15- 30 seconds. Repeat 3-5 times.

Benefits:

• Regulates thyroid function which is beneficial in PCOS.

Contraindications:

• Neck Injury

4. Baddhakona asana/ Butterfly pose

Duration: 15 minutes.

Benefits:

• Stimulates ovaries for better function.
• Helps relieve symptoms of menopause.
• If practiced till later stages of pregnancy then eases childbirth.
• Soothes menstrual discomfort.

Contraindication

• Groin injury
• Knee injury.

5.Dhanur asana/ Bow pose

Duration: 15-30 seconds. Repeat 3-5 times.

Benefits:

• Menstrual discomfort is relieved.

Contraindications:

• High /low blood pressure
• Migraine
• Insomnia
• Back/neck injury
• Pregnancy
• Menstruation

6.Bhujanga asana/ Cobra pose

Duration: 15-30 seconds. Repeat 3-5 times.

Benefits

• Stimulates ovaries for better function.

Contraindications

• Menstruatin
• Pregnancy
• Lower back pain

7.Paschimottan asana/ Forward bend pose

Duration: Hold on for 15-30 seconds. Repeat 3-5 times.

Benefits:

• Massages the pelvic region
• Reduces obesity
• Relieves menstrual discomfort.

Contraindications

• Diarrhoea
• Lower back pain/injury.

Pranayams for PCOS

8. Kapala Bhati pranayama

Kapala: head, Bhati : shine

Duration: 15 minutes. Start from 2 minutes and gradually increase to 15 minutes.

Benefits

• Stimulates pancreas to release insulin. Insulin resistance is a common problem in PCOS.
• Weight loss
• Blood circulation improves
• Healthy body organs

Contraindications

• Pregnancy
• Abdominal ulcers
• Menstruation
• High blood pressure
• Asthama

9. Anulom vilom pranayama

Duration: 30 mins to 1 hour.

Benefits

• Opens blockages in any artery, vein or any other part of the body.
• Improves blood circulation
• Increases flow of oxygen to all parts of the body
• Re- energizes the body.

Contraindications

• Severe throat infection
• Lung disorders
• Abnormal nasal growth.

Along with these exercises you need to control your diet. A BIG NO to junk, processed, ultra processed, oily and fried foods

Have simple meals of fresh fruits , vegetables, pulses.

Drink lots of water.

That's all. Take good care of your health.

10 ways to keep your Mouth Healthy and Odourfree

Bad breath is an issue that is caused by many reasons ranging from poor dental hygiene, gum diseases, tooth decay to conditions not related the mouth . The basic method to prevent bad breath is to keep brushing regularly along with proper tongue cleaning, which many people tend to overlook.
Here are some methods by which you can prevent bad breath and keep mouth healthy.


1.Scaling
When calculus(tartar) collects around your teeth, it weakens the gums causing swelling and bleeding from the gums along with bad breath. It also causes bone loss around the teeth. This eventually loosens the teeth.
What happens then?
 Not able to eat properly, not a photogenic smile and bad breath!!!.
What to do?
Start brushing regularly.
Get your teeth cleaned by the dentist and get the tartar removed because at this stage just brushing wont help.

2. Dentrifices

Dentrifices are available as toothpaste, gel and powder. They remove food particles along with the toothbrush and polish the tooth surface. Powdered forms are more abrasive and  should not be used by those who already have sensitive teeth. Desensitizing tooth pastes should be used only by people having sensitivity or when the dentist recommends, not otherwise. 

For children only a pea size amount of toothpaste is enough. Don't fill the whole brush with the paste. For children mild toothpastes come in different flavours.

3. Toothbrush

For all those who have sensitivity: Are you using a hard bristle brush? If yes, then stop now.

Use a soft bristle brush with minimum pressure.

 For children there are pedo brushes. They are small and  adapt easily to their mouths.They come in different shapes and colours to encourage them to clean their teeth. 

Brush twice daily.

4. Mouth washes

 Bad odour issues?

There are many mouthwashes available in the market.

After brushing your teeth , rinse your mouth with the mouth wash.  You can eat and drink after one hour. Let the mouthwash do its work. Continue this for a week. If  the problem still persists consult your dentist.

5. Warm saline rinses

When you have got your teeth cleaned by a dentist then mix some table salt in luke warm water and rinse your mouth. Warm saline rinses keep the gums intact and disease free.

 Even after a tooth extraction start doing warm saline rinses after 24 hours. The wound will heal faster. Add a pinch of alum for better results.

6. Rinse your mouth after meals

As we cannot brush after every meal ,make a habit of rinsing your mouth after meals. This will help to remove the food particles lodged in the mouth, preventing the risk of cavities and gum diseases.

7. Drink lots of  water

Drinking water will prevent the mouth from getting dry. Thus, it will reduce the risk of cavities and bad breath. It will also take away any lodged food particles straight into the stomach.

8. Cut on sugars

If you don't brush your teeth regularly and have a diet high on sugars, then you might need to visit your dentist sooner than you think. Sugars weaken the teeth and increase the risk of cavities. To prevent this start brushing regularly and have a diet high in fiber and protein content.

9. Flossing

Flossing can help you achieve what tooth brushes don't. A dental floss can help you to clean those areas where the tooth brush cannot reach. It helps you to clean in between two teeth very efficiently.

Thus, along with brushing use a floss to get better results.

10. Clean Tongue

Some people clean the teeth properly but overlook the tongue. Like the teeth , tongue has to be cleaned thoroughly. An unclean tongue promotes causes bad breath.

That's all.