NEET MDS Synopsis
Nimesulide
Pharmacology
Nimesulide
analgesic and antipyretic properties
Nimesulide is a relatively COX-2 selective, non-steroidal anti-inflammatory drug (NSAID) with analgesic and antipyretic properties. Its approved indications are the treatment of acute pain, the symptomatic treatment of osteoarthritis and primary dysmenorrhoea in adolescents and adults above 12 years old.
Banned - not used
Connective Tissue of the Gingiva
PeriodontologyConnective Tissue of the Gingiva and Related Cellular Components
The connective tissue of the gingiva, known as the lamina propria,
plays a crucial role in supporting the gingival epithelium and maintaining
periodontal health. This lecture will cover the structure of the lamina propria,
the types of connective tissue fibers present, the role of Langerhans cells, and
the changes observed in the periodontal ligament (PDL) with aging.
Structure of the Lamina Propria
Layers of the Lamina Propria:
The lamina propria consists of two distinct layers:
Papillary Layer:
The upper layer that interdigitates with the epithelium,
containing finger-like projections that increase the surface
area for exchange of nutrients and waste.
Reticular Layer:
The deeper layer that provides structural support and
contains larger blood vessels and nerves.
Types of Connective Tissue Fibers:
The lamina propria contains three main types of connective tissue
fibers:
Collagen Fibers:
Type I Collagen: Forms the bulk of the
lamina propria and provides tensile strength to the gingival
fibers, essential for maintaining the integrity of the gingiva.
Reticular Fibers:
These fibers provide a supportive network within the
connective tissue.
Elastic Fibers:
Contribute to the elasticity and flexibility of the gingival
tissue.
Type IV Collagen:
Found branching between the Type I collagen bundles, it is
continuous with the fibers of the basement membrane and the walls of
blood vessels.
Langerhans Cells
Description:
Langerhans cells are dendritic cells located among keratinocytes at
all suprabasal levels of the gingival epithelium.
They belong to the mononuclear phagocyte system and play a critical
role in immune responses.
Function:
Act as antigen-presenting cells for lymphocytes, facilitating the
immune reaction.
Contain specific granules known as Birbeck’s granules and
exhibit marked ATP activity.
Location:
Found in the oral epithelium of normal gingiva and in small amounts
in the sulcular epithelium.
Absent from the junctional epithelium of normal gingiva.
Changes in the Periodontal Ligament (PDL) with Aging
Aging Effects:
With aging, several changes have been reported in the periodontal
ligament:
Decreased Numbers of Fibroblasts: This
reduction can lead to impaired healing and regeneration of the PDL.
Irregular Structure: The PDL may exhibit a more
irregular structure, paralleling changes in the gingival connective
tissues.
Decreased Organic Matrix Production: This can
affect the overall health and function of the PDL.
Epithelial Cell Rests: There may be a decrease
in the number of epithelial cell rests, which are remnants of the
Hertwig's epithelial root sheath.
Increased Amounts of Elastic Fibers: This
change may contribute to the altered mechanical properties of the
PDL.
HAEMORRHAGIC DISORDERS
General Pathology
HAEMORRHAGIC DISORDERS
Normal homeostasis depends on
-Capillary integrity and tissue support.
- Platelets; number and function
(a) For integrity of capillary endothelium and platelet plug by adhesion and aggregation
(b) Vasoactive substances for vasoconstriction
(c) Platelet factor for coagulation.
(d) clot retraction.
- Fibrinolytic system(mainly Plasmin) : which keeps the coagulation system in check.
Coagulation disorders
These may be factors :
Deficiency .of factors
Genetic.
Vitamin K deficiency.
Liver disease.
Secondary to disseminated intravascular coagulation.or defibrinatian
Overactive fibrinolytic system.
Inhibitors of the factors (immune, acquired).
Anticoagulant therapy as in myocardial infarction.
Haemophilia. Genetic disease transmitted as X linked recessive trait. Common in Europe. Defect in fcatorVII Haemophilia A .or in fact .or IX-Haemaphilia B (rarer).
Features:
May manifest in infancy or later.
Severity depends on degree of deficiency.
Persistant wound bleeding.
Easy Bruising with Hematoma formation
Nose bleed , arthrosis, abdominal pain with fever and leukocytosis
Prognosis is good with prevention of trauma and-transfusion of Fresh blood or fTesh plasma except for danger of developing immune inhibitors.
Von Willebrand's disease. Capillary fragility and decreased factor VIII (due to deficient stimulatory factor). It is transmitted in an autosomal dominant manner both. Sexes affected equally
Vitamin K Deficiency. Vitamin K is needed for synthesis of factor II,VII,IX and X.
Deficiency maybe due to:
Obstructive jaundice.
Steatorrhoea.
Gut sterilisation by antibiotics.
Liver disease results in :
Deficient synthesis of factor I II, V, Vll, IX and X Incseased fibrinolysis (as liver is the site of detoxification of activators ).
Defibrination syndrome. occurs when factors are depleted due to disseminated .intravascular coagulation (DIC). It is initiated by endothelial damage or tissue factor entering the circulation.
Causes
Obstetric accidents, especially amniotic fluid embolism. Septicaemia. .
Hypersensitivity reactions.
Disseminated malignancy.
Snake bite.
Vascular defects : (Non thrombocytopenic purpura).
Acquired :
Simple purpura a seen in women. It is probably endocrinal
Senile parpura in old people due to reduced tissue support to vessels
Allergic or toxic damage to endothelium due to Infections like Typhoid Septicemia
Col!agen diseases.
Scurvy
Uraemia damage to endothelium (platelet defects).
Drugs like aspirin. tranquillisers, Streptomvcin pencillin etc.
Henoc schonlien purpura Widespeard vasculitis due to hypersensitivity to bacteria or foodstuff
It manifests as :
Pulrpurric rashes.
Arthralgia.
Abdominal pain.
Nephritis and haematuria.
Hereditary :
(a) Haemhoragic telangieclasia. Spider like tortous vessels which bleed easily. There are disseminated lesions in skin, mucosa and viscera.
(b) Hereditary capillary fragilily similar to the vascular component of von Willbrand’s disease
.(c) Ehler Danlos Syndrome which is a connective tissue defect with skin, vascular and joint manifestations.
Platelet defects
These may be :
(I) Qualitative thromboasthenia and thrombocytopathy.
(2) Thrombocytopenia :Reduction in number.
(a) Primary or idiopathic thrombocytopenic purpura.
(b) Secondary to :
(i) Drugs especially sedormid
(ii) Leukaemias
(iii) Aplastic-anaemia.
Idiopathic thrombocytopenic purpura (ITP). Commoner in young females.
Manifests as :
Acute self limiting type.
Chronic recurring type.
Features:
(i) Spontaneous bleeding and easy bruisability
(ii)Skin (petechiae), mucus membrane (epistaxis) lesions and sometimes visceral lesions involving any organ.
Thrombocytopenia with abnormal forms of platelets.
Marrow shows increased megakaryocytes with immature forms, vacuolation, and lack of platelet budding.
Pathogenesis:
hypersensitivity to infective agent in acute type.
Plasma thrombocytopenic factor ( Antibody in nature) in chronic type
ISO-ENZYMES
Biochemistry
ISO-ENZYMES
Iso-enzymes are physically distinct forms of the same enzyme activity. Higher organisms have several physically distinct versions of a given enzyme, each of which catalyzes the same reaction. Isozymes arise through gene duplication and exhibit differences in properties such as sensitivity to particular regulatory factors or substrate affinity that adapts them to specific tissues or circumstances.
Isoforms of Lactate dehydrogenase is useful in diagnosis of myocardial infarction. While study of alkaline phosphatase isoforms are helpful in diagnosis of various bone disorder and obstructive liver diseases.
CLINICAL SIGNIFICANCE OF ENZYMES
Biochemistry
CLINICAL SIGNIFICANCE OF ENZYMES
The measurement of enzymes level in serum is applied in diagnostic application
Pancreatic Enzymes
Acute pancreatitis is an inflammatory process where auto digestion of gland was noticed with activation of the certain pancreatic enzymes. Enzymes which involves in pancreatic destruction includes α-amylase, lipase etc.,
1. α-amylase (AMYs) are calcium dependent hydrolyase class of metaloenzyme that catalyzes the hydrolysis of 1, 4- α-glycosidic linkages in polysaccharides. The normal values of amylase is in range of 28-100 U/L. Marked increase of 5 to 10 times the upper reference limit (URL) in AMYs activity indicates acute pancreatitis and severe glomerular impairment.
2. Lipase is single chain glycoprotein. Bile salts and a cofactor called colipase are required for full catalytic activity of lipase. Colipase is secreted by pancreas. Increase in plasma lipase activity indicates acute pancreatitis and carcinoma of the pancreas.
Liver Enzymes
Markers of Hepatocellular Damage
1. Aspartate transaminase (AST) Aspartate transaminase is present in high concentrations in cells of cardiac and skeletal muscle, liver, kidney and erythrocytes. Damage to any of these tissues may increase plasma AST levels.
The normal value of AST for male is <35 U/ L and for female it is <31 U/L.
2. Alanine transaminase (ALT) Alanine transaminase is present at high concentrations in liver and to a lesser extent, in skeletal muscle, kidney and heart. Thus in case of liver damage increase in both AST and ALT were noticed. While in myocardial infarction AST is increased with little or no increase in ALT.
The normal value of ALT is <45 U/L and <34 U/L for male and female respectively
Markers of cholestasis
1. Alkaline phosphatases
Alkaline phosphatases are a group of enzymes that hydrolyse organic phosphates at high pH. They are present in osteoblasts of bone, the cells of the hepatobiliary tract, intestinal wall, renal tubules and placenta.
Gamma-glutamyl-transferase (GGT) Gamma-glutamyl-transferase catalyzes the transfere of the γ–glutamyl group from peptides. The activity of GGT is higher in men than in women. In male the normal value of GGT activity is <55 U/L and for female it is <38 U/L.
2. Glutamate dehydrogenase (GLD) Glutamate dehydrogenase is a mitochondrial enzyme found in liver, heart muscle and kidneys.
Muscle Enzymes
1. Creatine Kinase Creatine kinase (CK) is most abundant in cells of brain, cardiac and skeletal.
2. Lactate Dehydrogenase
Lactate dehydrogenase (LD) catalyses the reversible interconversion of lactate and pyruvate.
Management of Skin Loss in the Face
Oral and Maxillofacial SurgeryManagement of Skin Loss in the Face
Skin loss in the face can be a challenging condition to manage, particularly
when it involves critical areas such as the lips and eyelids. The initial
assessment of skin loss may be misleading, as retraction of skin due to
underlying muscle tension can create the appearance of tissue loss. However,
when significant skin loss is present, it is essential to address the issue
promptly and effectively to prevent complications and promote optimal healing.
Principles of Management
Assessment Under Anesthesia: A thorough examination
under anesthesia is necessary to accurately assess the extent of skin loss
and plan the most suitable repair strategy.
No Healing by Granulation: Unlike other areas of the
body, wounds on the face should not be allowed to heal by granulation. This
approach can lead to unacceptable scarring, contracture, and functional
impairment.
Repair Options: The following options are available for
repairing skin loss in the face:
Skin Grafting: This involves transferring a piece
of skin from a donor site to the affected area. Skin grafting can be
used for small to moderate-sized defects.
Local Flaps: Local flaps involve transferring
tissue from an adjacent area to the defect site. This approach is useful
for larger defects and can provide better color and texture match.
Apposition of Skin to Mucosa: In some cases, it may
be possible to appose skin to mucosa, particularly in areas where the
skin and mucosa are closely approximated.
Types of skin grafts:
Split-thickness skin graft (STSG):The most common type, where only the epidermis
and a thin layer of dermis are harvested.
Full-thickness skin graft (FTSG):Includes the entire thickness of the skin,
typically used for smaller areas where cosmetic appearance is crucial.
Epidermal skin graft (ESG):Only the outermost layer of the epidermis is
harvested, often used for smaller wounds.
Considerations for Repair
Aesthetic Considerations: The face is a highly visible
area, and any repair should aim to restore optimal aesthetic appearance.
This may involve careful planning and execution of the repair to minimize
scarring and ensure a natural-looking outcome.
Functional Considerations: In addition to aesthetic
concerns, functional considerations are also crucial. The repair should aim
to restore normal function to the affected area, particularly in critical
areas such as the lips and eyelids.
Timing of Repair: The timing of repair is also
important. In general, early repair is preferred to minimize the risk of
complications and promote optimal healing.
Space Maintainers
PedodonticsSpace Maintainers: A fixed or removable appliance designed
to maintain the space left by a prematurely lost tooth, ensuring proper
alignment and positioning of the permanent dentition.
Importance of Primary Teeth
Primary teeth serve as the best space maintainers for the permanent
dentition. Their presence is crucial for guiding the eruption of permanent
teeth and maintaining arch integrity.
Consequences of Space Loss
When a tooth is lost prematurely, the space can change significantly within a
six-month period, leading to several complications:
Loss of Arch Length: This can result in crowding of the
permanent dentition.
Impaction of Permanent Teeth: Teeth may become impacted
if there is insufficient space for their eruption.
Esthetic Problems: Loss of space can lead to visible
gaps or misalignment, affecting a child's smile.
Malocclusion: Improper alignment of teeth can lead to
functional issues and bite problems.
Indications for Space Maintainers
Space maintainers are indicated in the following situations:
If the space shows signs of closing.
If using a space maintainer will simplify future orthodontic treatment.
If treatment for malocclusion is not indicated at a later date.
When the space needs to be maintained for two years or more.
To prevent supra-eruption of opposing teeth.
To improve the masticatory system and restore dental health.
Contraindications for Space Maintainers
Space maintainers should not be used in the following situations:
If radiographs show that the succedaneous tooth will erupt soon.
If one-third of the root of the succedaneous tooth is already calcified.
When the space left is greater than what is needed for the permanent
tooth, as indicated radiographically.
If the space shows no signs of closing.
When the succedaneous tooth is absent.
Classification of Space Maintainers
Space maintainers can be classified into two main categories:
1. Fixed Space Maintainers
These are permanently attached to the teeth and cannot be removed
by the patient. Examples include band and loop space maintainers.
Common types include:
Band and Loop Space Maintainer:
A metal band is placed around an adjacent tooth, and a wire loop
extends into the space of the missing tooth. This is commonly used
for maintaining space after the loss of a primary molar.
Crown and Loop Space Maintainer:
Similar to the band and loop, but a crown is placed on the
adjacent tooth instead of a band. This is used when the adjacent
tooth requires a crown.
Distal Shoe Space Maintainer:
This is used when a primary second molar is lost before the
eruption of the permanent first molar. It consists of a metal band
on the first molar with a metal extension (shoe) that guides the
eruption of the permanent molar.
Transpalatal Arch:
A fixed appliance that connects the maxillary molars across the
palate. It is used to maintain space and prevent molar movement.
Nance Appliance:
Similar to the transpalatal arch, but it has a small acrylic
button that rests against the anterior palate. It is used to
maintain space in the upper arch.
2. Removable Space Maintainers
These can be taken out by the patient and are typically used when more
than one tooth is lost. They can also serve to replace occlusal function and
improve esthetics.
Common types include:
Removable Partial Denture:
A prosthetic device that replaces one or more missing teeth and
can be removed by the patient. It can help maintain space and
restore function and esthetics.
Acrylic Space Maintainer:
A simple acrylic appliance that can be used to maintain space.
It is often used in cases where esthetics are a concern.
Functional Space Maintainers:
These are designed to provide occlusal function while
maintaining space. They may include components that allow for
chewing and speaking.
Types of Removable Space Maintainers
Non-functional: Typically used when more than one tooth
is lost.
Functional: Designed to provide occlusal function.
Advantages of Removable Space Maintainers
Easy to clean and maintain proper oral hygiene.
Maintains vertical dimension.
Can be worn part-time, allowing circulation of blood to soft tissues.
Creates room for permanent teeth.
Helps prevent the development of tongue thrust habits into the
extraction space.
Disadvantages of Removable Space Maintainers
May be lost or broken by the patient.
Uncooperative patients may not wear the appliance.
Lateral jaw growth may be restricted if clasps are incorporated.
May cause irritation of the underlying soft tissues.
Blood
PhysiologyBlood is a liquid tissue. Suspended in the watery plasma are seven types of cells and cell fragments.
red blood cells (RBCs) or erythrocytes
platelets or thrombocytes
five kinds of white blood cells (WBCs) or leukocytes
Three kinds of granulocytes
neutrophils
eosinophils
basophils
Two kinds of leukocytes without granules in their cytoplasm
lymphocytes
monocytes