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Contents• Introduction• Tests done by dentists• Hematological• Urine Analysis• Biochemistry :Renal function tests Tests – diseases of bone Liver function tests Lipid Analysis• Immunological investigations• Histopathology, cytology and immunofluorescent studies Microbiology• Radiological• Conclusion• References
INTRODUCTION• Diagnosis & identification - disease by careful investigation o patients signs, symptoms and history• Carefully crafted history and physical examination - satisfactory – diagnosis• Times when more information is required through the use of diagnostic tests.• Clinical and/or lab data must be used to distinguish between different diagnoses.
importance of laboratory investigations• laboratory tests - important in assisting & management of the patient during treatment of disease besides diagnosis.• Used-1. screen - disease in asymptomatic individual2. to establish or exclude presence of diseases in symptomatic patients3. assist the practitioner in the management of the patient.
important characteristics of a laboratory test• Accuracy• Cost• Interfering factors• Precision• Reference range• Sensitivity• Specificity
TESTS ADVISED BY DENTISTS Acc. Sonis, Fazio & Fang
Depending upon the specimens submitted1. Hematological2. Biochemical3. Immunological4. Histopathological – histological & Immunofluorescent5. Microbial6. Radiological
Depending upon the organs involved• Heart • Skin• Vascular system • Eye• Respiratory system • Bones & joints• GIT • Skeletal muscle• Liver, gallbladder & pancreas • CVS• Kidney & genitourinary • Mental illness• Female genital • Endocrine system• Breast • Infectious diseases • Immunological diseases
BLOOD CHEMISTRY TESTS A. . Estimation of electrolytes B. . Renal function C. .Liver function D. .Thyroid Function E. . Metabolic bone disease F. . Other tests .
A. Estimation of electrolytes• Maintain fluid levels inside & outside cells• Osmotic gradient – nerve condtn. Muscle func,hydration & maintaining Ph levels1. SODIUM :• Loss of sodium results extracellular fluid volume• Circulation, renal function, and central nervous system function.• Normal : 136-145 m Eq/l
2. Chloride• Normal : 95 to 108 mEq/l.• Important - maintenance of acid-base balance
3. Potassium• determines neuromuscular irritability.• or conc. impair - ability of muscle tissue contract• Normal - 3.5 to 5.2 mEq/l.
4. Bicarbonate• Bicarbonate–carbonic acid buffer - maintaining normal pH of body fluids.• basis for assessing acid-base balance.• Normal : 24 to 30 mEq/l.
Dentists• Electrolytes -• Maintain - Ph• Proteins are denatured and digested• Enzymes lose their ability to function and death may occur.• possibly life threatening.• could require hospitalization and intravenous electrolytes.
b. renal function test1. blood urea nitrogen• Normal value of BUN in adults: 8 – 18 mg %. 10 – 20 mg/dl sonis symptom - >50 mg/dl
Clinical significance :• Pre renal causes – reduced flow to kidney, shock, blood loss, dehydration, increased protein catabolism, injuries, burns, fever• Renal causes – acute renal failure, glomerulonephritis, malignant hypertension, chronic renal failure, DM• Post renal causes – urinary obstruction by stones, tumors
• Decreased blood urea nitrogen –• Poor nutrition• High fluid intake• Excessive administration of i.v fluids• Liver damage• Late pregnancy, infancy, acromegaly.
2. creatinine• Creatinine - catabolic product of creatinine phosphate - used for skeletal muscle contraction.• excreted entirely - kidneys• amount in blood - directly proportional to renal excretory function• diagnose impaired renal function• Normal range – 0.5 – 1.6mg% or 1.5 mg/dl• symptom > 4mg/dl
C. LIVER FUNCTIONSerum bilirubinUrine urobilinogenSerum albumin – globulinSerum alkaline phosphataseAST & ALT
1.serum bilirubin• Bilirubin : excreted - intestines.• Intestines converted - colorless compound - urobilinogen.• Level of bilirubin elevates - excessive hemolysis• Inability of liver to eliminate bilirubin (liver damage or obstruction of bile duct)• yellow color - product• skin, mucous membranes, sclera of the eye, plasma and urine• Excess bilirubin - associated - hepatitis
• Jaundice - total serum bilirubin rises• Normal Value → 0.1 to 1.2 mg / 100 ml 5.1–17.0 micro mol/LHigh values:• Hemolytic Anemia• Biliary obstruction• Hepatitis• Malignant Hepatic Disease
2. SERUM GLUTAMIC OXALOACETIC TRANSAMINASE (SGOT) SERUM GLUTAMIC PYRUVIC TRANSAMINASE (SGPT)• enzymes -large amounts - liver, heart, kidney and skeletal muscle• metabolism of amino acids and carbohydrates.• NORMAL VALUES :• SGOT also called Aspartate Aminotransferase 6 -25 I U/ L• SGPT also called Alanine Aminotransferase 3– 26 I U/ L
screening for hepatitis b &c• Detection of hepatitis B surface antigen:• Hepatitis B virus (HBV) is a double stranded DNA spherical particle with a double shell. - referred as the Dane particle.• Antigens which have so far been associated with HBV are as follows ;• Hepatitis B surface antigen (HBsAg) : This was first noticed in the blood of an Australian aborigine hence earlier was termed as Australia antigen.• Hepatitis B core antigen (HBcAg)• Hepatitis B e antigen (HBeAg).
• Infection - HBV i- entry of virus through the skin or mucous membranes into the blood or body fluids.Routes of transmission• transfusion of blood or blood products.• HBV contaminated needles, syringes or prickers.• Close personal contact with a person with hepatitis B• Contact with blood specimen (Laboratory personnel those who handle the specimen)• Transmission by blood sucking insects or bed bugs.
• detection of hepatitis – b surface antigen (hbsag) by direct enZyme linKed immunosorbent assay (elisa) :• HBsAg formerly called Australia antigen is• Reduce incidence of post-transfusion hepatitis, testing for HbsAg is mandatory for blood products intended for human use.• Care – Rx – viral particles – saliva & other body secretions.
• Signs• H/O: Alcohol abuse, hepatitis ,abnormal bleeding• Features – improper function Liver – Def production clotting factors – PT elevated• So investigation & physicians opinion – needed – precautions
3. serum albumin and globulin• total protein• important - coagulation, transport hormones, act on antibodies• act - buffers with enzymes• help - maintain osmotic pressure.
• Serum albumin - synthesized in liver• globulins - produced - plasma cell• Normal Values:• Total Protein 6.0 to 7.8 g / 100 ml or 6.0 to 8.3 gm/dL• Albumin 3.2 to 5.6 g / 100 ml• Globulin 2.3 to 3.5 g / 100 ml• A / G Ratio 1.5 to 1 to 2.5:1
Total proteinsHigh Albumin - rare but dehydration and shock.Low Albumin : same as proteins.High Globulin : Multiple myeloma, Nephrosis, Chronic infections, Collagen diseases, Liver diseasesLow Globulin : Burns and severe malnutrition.
5.Alkaline phosphatase• high concentration - growing bone, bile, placenta.• Normal level: 30 to 115 U/l.IncreasedA. In childrenB. Osteoblastic bone diseaseC. Hepatic disease / bileobstruction - stone, stricture, neoplasm.D. Pregnancy.Decreased:• Hypophosphatasia, hypothyroidism, malnutrition.
Normal values and changes in two types of Jaundice Hepatocellular UncomplicatedTests Normal Values Jaundice Obstructive JaundiceBilirubin- Direct 1. – 0.3 mg/dL Increased Increased-Indirect 2. – 0.7 mg/dL Increased IncreasedUrine bilirubin None Increased IncreasedSerum albumin/Total Albumin, 3.5-5.5 g/dL Albumin decreased Unchangedprotein Total protein, 6.5-8.4 g/dLAlkaline phosphatase 30-115 units /L Increased (+) Increased (++++)Prothrombin time INR of 1.0 – 1.4 After Prolonged if damage Prolonged if obstruction Vitamin K, 10% increase severe and does not marked, but responds to in 24 hours respond to parenteral parenteral vitamin K Vit K ALT, AST ALT, 5-35 units/L, AST, 5-40 Increased in Minimally increased units/L hepatocellular damage, viral hepatitis
HYPO THYROIDISM HYPER THYROIDISM• Catecholamines in LA + • CNS depression – present stress in dental operatory • Administration of narcotic• Ppt thyroid Astorm analgesics increase risk• Characterised High fever, CNS depression& collapse psycosis, CNS depresssion, vomiting diaorrhea – risk CHF Pt asked for Heat & cold intolerance, wt gain /loss, change in appetite bowel habits , muscle weakness and palpitations
E. Metabolic Bone Disease• Jaw lesions – radiographic examination• Systemic jaw diseases-• Pagets disease, FD, Primary & Sec. Hyperparathyroidism, Osteoporosis, MM, Osteogenic sarcoma or metastatic malignancy• Serum Ca, P,& alkaline phosphatase -
Serum Ca, P• Serum cal I / serum phosphorus• Measured : mg/dl• serum Ca conc. X serum P conc. = constant• 30 to 40 mg/dl = Normal adults• 50 to 60 mg/ dl = growing children
• GA & surgical procedures – cardiac arrythmmias, heart block• Hypercalcaemia - excessive skeletal calcium release, increased intestinal calcium absorption, or decreased renal calcium excretion.• serum Ca – hypo proteinmia, due decreased binding by serum protein & renal disease.
2. Alkaline phosphatase• Oestoblasts• enzyme - produced - small amounts –liver• larger amounts by osteoblasts.• active in bone formation and therefore is found at higher levels there.• result increased osteoblastic activity• In association – obstructive liver disease, amyloid disease, leukemia & sarcoidosis
• Normal values for serum Alkaline phosphatase• King Armstrong Units – 4 to 13• Brodansky Units - 1.5 to 4.5• International Units - 30 to 85 IU
Values Serum calcium Serum Serum phosphates mg/dl phosphorus Units /dl P/dlNormal 8.8 to 10.5 2 to 5 1-4Rickets Normal Decreased – Increased 20 to 40 x Exc tetany normalOsteomalacia Decreased Decreased Little if any changePaget’s Disease Normal Normal Occasionally elevatedHyperparathyroidism Increased Decreased Increased 2 to 50 x normalOsteogenic normal Normal Slightly increaseImperfectaSolitary Bone cysts normal normal normalMetatstatic Oseous May be elevated Normal Normal / slightlyDisorders elevatedTetany 7 mg ca/dl or less Normal / elevated Normal
G. Other Tests1. Acid phosphatase• Phosphatases active at pH 4.9 are present - high conc.• prostate gland, erythrocytes, platelets, reticuloendothelial cells, liver, spleen, and kidney.• Normal levels: 0.8 IU/l.• Increased: carcinoma of the prostate
2. Serum amylase• Normal level: 5 to 75 IU/l.• Increased:• Acute pancreatitis, pseudocyst of the pancreas,• obstruction of pancreatic ducts (carcinoma, stone, stricture,duct sphincter spasm after morphine), and parotitis.• Decreased:• Acute and chronic hepatitis• Pancreatic insufficiency,• toxemia of pregnancy.
3. Serum lipaseNormal level: 0.2 to 1.5 units.Increased:• acute or exacerbated pancreatitis• obstruction of pancreatic ducts- stone or neoplasm.
Check on triglycerides• HDL : good" cholesterol - removes excess cholesterol from the blood and takes it to the liver• LDL: BAD: High levels- linked - increased risk of heart and blood vessel disease, inlcuding coronary artery disease, heart attack and death.
5. Creatine phosphokinase (CPK)• Male: 50 to 180 IU/l, female: 50 to 60 IU/l.• Myocardial infarction, trauma to muscle, malignant• Hyperthermia muscular dystrophies, polymyositis, severe Muscular exertion (jogging), hypothyroidism
6. Lactate dehydrogenase (LDH)• Normal level: 45 to 100 U/l.• Increased:• Tissue necrosis, particularly those involving acute injury to heart, red cells, kidney, skeletal muscle, liver, lung
• In all these Pt where CVS disease – suspected• Signs – cyanosis, clubbing, peripheral edema• H/O : Palpitations, dizziness• Lab inv : cholesterol > 240mg/dl
7. Serum uric ACID• Range : 4 mg /dl to 8.5 mg/dl - Males• 2.8 to 7.5 mg/dl – females• Metabolic end product – nucleoprotein metabolism – derived purine mol
The Function of Urinary SystemA) Excretion & Elimination: removal of organic wastes products from body fluids (urea, creatinine, uric acid)B) Homeostatic regulation: Water -Salt Balance Acid - base BalanceC) Enocrine function: Hormones
Indication• Disease of kidney & UI• As a screening procedure in systemic Disease – diabetes , Jaundice• Diagnosis – metabolic diseases , enteric fever• Hormonal studies – pregnancy, steroid metabolites & catecholamines
TYPE Presence in Possible causes of abnormal normal urine amts of cells in urineRBC’s 0-5 cells / hpf Inflammatory diseses Acute glomerulonephritis Hypertension, renal infarction, trauma, stones, bleeding diseases, Use of anti coagulantsWBC’s 0-8 cells /hpf Polynephritis, cystitis, urethritis, prostatitis, Transplant rejection,Sq epi cells Often present Vaginal contaminationTumor cells Not often present Tumors of Renal pelvis, Renal parenchyma, Ureters, Bladder
CastsUrinary casts are tiny tube-shaped particles made up of white blood cells, red bloodcells, or kidney cells.form in kidney structures called tubules. Casts are held together by a proteinreleased by the kidney.Type Description causesHyaline casts Colourless,Transperent, Low RI Strenous ex, acute glomerulonephritis, Acute polynephritis, Malignant hypertension, Chronic renal diseaseRed blood cells casts Red cells in hyaline matrix AGN, Lupus N, Collagen Yellow orange colour disease, Renal infarction, High - RI Malignant hypertensionGranular casts Opaque granules in matrix Nephrotic syn Congestive heart failure, Acute/ chronic renal diseaseFatty casts Fat globules Nephrotic synd, DM, Mercury & ethylene glycol poisioningEpithelial cells Hayaline matrix Glomerulonephritis, Vascuclar High -RI disease, Toxin, Virus
Red blood cell cast in urine White blood cell cast in urine Urinary casts. (A) Hyaline cast (200 X); (B) erythrocyte cast (100 X); (C) leukocyte cast (100 X); (D) granular cast (100 X)
4. Oncology • Saliva - analyzed - presence tumor markers, mutated genes • exfoliated cells - saliva - used :simple, non-invasive method for obtaining DNA for gene analysis. • diagnosis / detection - cancers distant oral cavity.p53 levels of salivary antibodies to p53.CA 125 Elevated – ovarian carcinomasc-erbB-2 & Epidermal Elevated – breast cancersgrowth factorAlbumin Stomatitis associated chemotherapyIngested nitrate salivary nitrate - indicative ingested nitrate converted to nitrite and nitrosamine contribute - development of oral and gastric carcinomasRecurrent oral cancer Salivary concentrations - carbohydrate antigens (Cyfra 21-1, TPS and CA 125) : found to significantly increase
HISTOPATHOLOGY, CYTOLOGY AND IMMUNOFLUORESCENT STUDIES
• Study - microscopic anatomy of cells and tissues - plants and animals.• Performed by examining cells and tissues - sectioning and staining• Followed by examination - light microscope or electron microscope
Commonly used methodsExfoliative cytology :• chair side• Screening large areas, un limited repetition• Early detection – maliganancy• Lesions – herpes & candida – scrapping• determining site of biopsyAspiration Cytology :• Microinvasive procedureBiopsy :• gross & microscopic exam.• Tissues of cells – removed living patients
BIOPSY USES COMPLICATION• Diagnosis of pathological • Hemorrhage lesion • infection• Grading of tumor • Poor wound healing• Neoplastic & non neoplastic • Spread of tumor cells lesions • Injury adjacent cells• Metastatic lesions • Reaction - LA• Evaluation of recurrence• Therapeutic assessment• Differentiation – Benign & malignant
Immufluorescence studies• Technique – antibodies or antigens are labeled with fluorescent dyes• Used - visualize - subcellular distribution of biomolecules.• Immunofluorescent labeled tissue sections or cultures• studied using a fluorescence microscope or by confocal microscopy• Three types of fluorescent antibody• Procedure - direct immunofluorescence, indirect immunofluorescence
Direct immunofluorescencetechnique Indirect Immunofluorescence technique • Auto antibodies bound to patient’s • detecting antibodies circulating - tissue blood. • Can be detected. • monkeys esophagus - patient’s • Frozen section - patient’s tissue • serum is added. • Antihuman antibodies tagged with • excess serum - washed away. fluorescein dye is added. • Antihuman antibodies tagged - • Excess suspension - washed fluorescein dye added. away. • washed • Section is viewed under • viewed under microscope (UV) microscope (uv light).
ASPIRATEDISEASE AspirateOKC Thick , cheesy ,yellow granular fluid Keratin dough like consistencyAmeloblastoma Clear brownish yellow colour fluidOdontogenic cyst Straw colored fluid : + cholesterol crystalsSebaceous cyst Sebum – homogeneous & yellowish cheesy subThyroglossal duct cyst Dark amber col.Hemangioma, varicosities, hematoma Blue bloodAneurysm & arteriovenous fistula Brighter red bloodActinomycosis Pus with yellow granule - sulphur
Features DiseaseRuston bodies Dentigerous cystReed sternberg cell Hodgkins diseaseSaw tooth appearance Lichen planusPicket fence / tombstone Primodial cystLipschtz bodies Herpes simplex infAntischkow cell Apthous ulcer, sickle cell, megaloblastic and fe def anemiaLiesegang ring CEOTCart wheel / checker board MMappLava flowing around boulder Dentin DysplasiaHoney comb/ swiss cheese Adenoid cystic carcinoma of salivary glandpatternCell in cells Hereditary benign intraepithelial keratosis
SKIN LESIONS :LP Saw tooth rete pegsPemphigus Tzank cells’Pemphigoid Sub epithelial vesicles - acantholysisCYSTSOKC Tomb stone basal cells & satellite cystsDENTIGEROUS CYST Cholesterol cleftsINFECTIONSTB Langhans gaint cells & epitheloid cellsACTINOMYCOSIS Col of fungus- ray fungsBONE LESIONSFD Trabaculae- chinese lettern patternPAGETS DISEASE Jig saw puzzle/ mosaic patternBENIGN & MALIGNANT TUMORSSCC Multiple keratin pearl formationFibrosarcoma Cells – herring bone pattern
METHODS OF DETECTION OF ANTIBODIES 1. Immuno-precipitation Assays = detect antibodies in solution = qualitative indication of the presence of antibodies = end-point is visual flocculation of the antigen and antibody in suspension 2. Complement Fixation = based on the activation or fixation of complement following binding of complement factors to Ag-Ab immune complexes
3. Neutralization = effectively of an organism or activity of toxin is neutralized by specific antibody = rarely used for diagnostic purposes = mainly used to detect antibody formation after vaccination4. Particle Agglutination = relatively simple and fast = capable of detecting lower concentration of antibodies = designed to detect antibodies to viruses, subsequent to interaction or vaccination = utilize Ag coated latex particles, coal particles, = direct and indirect methods
5. Immunofluorescence– requires use of microscope equipped provide ultraviolet illumination or– an instrument capable of irradiating the assay with UV light and detecting resultant fluorescence with a fluorometer6. Enzyme Immunoassay– most sensitive– usually indirect assay that depends on the use of an antihuman IgG or IgM antibody conjugate– antibody conjugate (if present) is made to attach to enzyme which catalyzes conversion of substrate to a colored product which will then be read with the use of a spectrophotometer7. Radioimmunoassay = high sensitivity
Tests for HIVLaboratory diagnosis of HIV infection❑ Detection of anti-HIV antibodies❑ Detection of antigen❑ Detection of viral nucleic acid❑ Virus isolation.Investigations for HIV non-specific testsLymphocytopenia below 2000 cu.mmDecrease in CD4 countLow t4:t8 ratio (t helper/t suppressor cell ratio) increase inIgG and IgA.
Specific TestsPrimary tests❑ EIA/ELISA❑ Polymerase chain reactionConfirmatory tests❑ Western blot❑ RIPA❑ Immunofluorescence assay❑ DNA/RNA amplification tests
PCR – Polymerase Chain Reaction –• uses - amplify viral RNA from blood,• detect even small amounts of virus in newly infected person.• expensive, time consuming, and not readily availableRIPA –• done when antibody levels are low or Western Blot results - unclear• expensive, difficult to perform, and not often used.Immunofluorescence Assay –• Confirmatory test used when Western Blot results are unclear.• used instead of a Western Blot after an ELISA test. DNA/RNA Amplification Tests –• Tests similar to PCR• used when the result of a western blot is unclear.
• Radiographs – recomended for demonstrating varios lesións
Region required Standard views Additional viewsSKULL PA, Lateral skull SMVFACIAL BONES OM,Lateral Red exposure SMVPNS OM for max antrum Upper occlusal/lat SMV.OPG,CTOrthodontics OPG, Cephalometric skullNasal bones OM – 30 ,Lateral,MANDIBLE OPG Lat oblique, PA mandible MAnd.OcclusalTMJ Transcranial,Lat oblique, Transpharyngeal,Arthrog OPG raphy, reberse townes, Ct,,MRI
SPECIAL RADIOGRAPHIC TECNIQUES• CT• Digital Radiography• Subtraction radiography• Radionuclide imaging• Sonography
Tests for Syphilis• Diagnosis - achieved either by direct identification - pathogen - serological findings & treponema pallidum
Serology• confirmatory test - FTAABS - golden standard• enzyme immunoassays, Western blot technique• Serology in congenital syphilis: Finding specifi c IgM anti- treponemal antibodies is helpful in diagnosing congenital infection• If titers > in infant then mother