Human Disease YR3 #1 Flashcards
What is the function of an osteoblast?
It forms bone
What is the function of an osteoclast?
It resorbs bone
What differentiate to form osteoblasts?
Mesenchymal progenitor cells
What differentiates to form osteoclsts?
Myeloid progenitor cells
Name 5 cell signalling ligands stimulate the activity of osteoblasts?
TNFaIL-1IL-11PTHPGE2
What do osteoblasts release to activate the differentiation of osteoclasts?
RANKL
What vitamin is essential for bone health?
Vitamin D
Explain the 4 steps in the cycle of vitamin D formation in our body?
- Photons from sun hit skin2. 7DHC is activated and travels to the liver3. At the liver it is converted to 25(OH)vit D (then stored)4. It then travels to the kidney and becomes 1,25(OH)2 vit D (physiologically active)
What ion is essential for bone formation/turnover?
Calcium
If Ca is low what occurs?
Bone resportion
If Ca is high what occurs?
Bone formation
What are the 5 main substances that aid the control of Ca metabolism? and which organs?
Ascorbic acidVit DCaPTHPO4
BoneGIParathyroid glandKidneyLiver
What is the definition of Paget’s disease of the bone?
Localised disorder of bone turnoverIncreased bone resorption followed by increased bone formationLeading to disorganised bone: bigger, less compact, more vascular and more susceptible to deformity and fracture
How is Paget’s disease of the bone transmitted?
Genetically (15-30% familial)Anglo-Saxon originsChronic viral infection within osteoclasts
What are the symptoms for Paget’s disease?
> 40 age with bone painBone deformityExcessive heat over pagetic boneNeurological complications such as nerve deafness
What are the presentations of Paget’s disease?
Isolated elevation of serum alkaline phosphataseBone pain and local heatBone fracture or deformityHearing loss
What is the treatment for Paget’s disease?
Surgical intervention (hard if asymptomatic)Don't treat if raised alkaline phosphatase aloneIV bisphosphonates therapy with one off IV zoledronic acid
What is the difference between Rickets and Osteomalacia?
Rickets - before the epiphyseal lines are closed| Osteomalacia - adult disease
What is the definition of Rickets and Osteomalacia?
A severe vitamin D or Ca deficiency causing insufficient mineralisationMuscle function is also impaired in low vit D states
How are vitamin D and Ca related?
Vit D stimulates the absorption of Ca and PO4 from the gut and Ca and PO4 then becomes available for bone mineralisation
What is the presentation of Rickets?
Stunted growthCurved spineWide joints at elbow and wristCurved legs (splayed)Wide bones and ankles
What are the symptoms for Osteomalacia?
Aches and painsInability for muscle coordination Waddle gaitStruggle out of chair
Treatment for Osteomalacia and Rickets?
Ca and vit D supplementation
What is the definition of osteogenesis imperfecta?
Genetic disorder of CT characterised by fragile bones from mild trauma or everyday acts
What are the 4 most common phenotypes for osteogenesis imperfecta?
28 different genetic variation existType I: milder form when child starts to walk but can present in adultsType II: lethal by age 1Type III: progressive deforming with severe bone dysplasia and poor growthType IV: more severe version of type I
What is the presentation for osteogenesis imperfecta?
Growth deficiencyDefective tooth formationhearing lossBlue scleraScoliosisLigamentous laxityEasy bruising
What is the surgical, medical, social and genetic management options for osteogenesis imperfecta?
Surgical to treat fractureMedical to prevent fracture via IV bisphosphonatesSocial adaptations to education and socialGenetic via counselling for parents and next generation
What is the definition of osteoporosis?
A metabolic bone disease characterised by low bone mass and micro architectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk T- score < -2.5 SDs
What other factors increase the risk of bone fractures?
AgeBMDFallsBone turnover
What is a good website to calculate the risk of fracture for a patient?
Frax
What T-score is needed for an osteoporosis diagnosis?
< -2.5 SDs
What type of scan is used to help diagnose osteoporosis?
Dual energy x-ray absorptiometry (DXA)
How common is osteoporosis, for men and women?
50% of women over 50 will have an osteoporotic fracture before death (Men 1/5)A 50 year old women had a 17% risk of hip fracture
What are the endocrine causes of osteoporosis?
ThyrotoxicosisHyper/HypoparathyroidismCushingsHyperprolactinemiaHypopituitarismEarly menopause
Which rheumatic disease can cause osteoporosis?
RAAnkylosing spondylitisPolymyalgia rheumatica
Which GI disease can cause osteoporosis?
UC and Crohn’sLiver diseaseMalabsorption
Which medications can cause an increase risk of osteoporosis?
SteroidsPPI (proton-pump inhibitors)Enzyme inducing antiepileptic medicationsAromatase inhibitorGnRH inhibitorsWarfarin
What preventions can be put in place to reduce osteoporotic fractures?
Minimise risk factorsEnsure good Ca and vit D statusFall prevention strategiesMedications
What is the treatment for osteoporosis?
HRT until 60 years oldSelective oestrogen receptor modulatorsBisphosphonatesDenosumab
What are the side effects of HRT?
Increased risk of blood clotsIncreased risk of breast cancerIncreased risk of heart disease and stroke
What are the side effects of SERMS?
Hot flushesIncreased clotting risksLack protection at hip site
What are the side effects of bisphosphonates?
OesophagitisIritis/UveitisAtypical femoral shaft fracturesNecrosis of the jaw
What is Denosumab?
Monoclonal antibody against RANKLReduces osteoclastic bone resorptionSubcut injection every 6 months
What are the side effects for Denosumab?
AllergySymptomatic hypocalcemia if given when vit D is depleteAtypical femoral shaft fractures
What are the side effects of Teriparatide?
Injection site irritationRarely hypercalcaemiaAllergy
What common features do all CT diseases share?
Auto-antibodies presentMainly femaleAll have oral features
What antibody can be used to support a clinical diagnosisof Lupus?
ANA (95% +ve in CTD)| Lupus
What are the oral presentations for systemic lupus?
1/1000
Oral ulcers (painless)Dry mouth/eyes(Fatigue, arthralgia and malar rash across nose)
What are the treatments for systemic lupus, specifically oral symptoms?
AspirinImmunosuppressive medications )sides thrush and ulcers)(methotrexate and rituximab)Check patients bloodsSuncream, hydroxychloroquine, anti-inflamm and steroids
What are the oral presentations for Sjogren’s syndrome?
Dry mouth (xerostomia) –> dental decay and oral infectionSalivary gland swellingsDry eyes (xerophthalmia) –> burning and gritty eyesFatigueArthralgia
How to confirm a suspicions of Sjogren’s?
Schirmer’s test, saliva test, blood test (RO and La antibodies)Labial gland biopsy (referral)
What are the 2 types of Sjogren’s?
Primary (just the disease)| Secondary (complication of other CTDs)
What is the treatment for Sjogren’s, specifically for oral symptoms?
Saliva substitutes: water, BioXtra oral gel, Saliva Othana, Biotene oral gel, High Fl toothpasteSugar free chewing gumRegular dental check ups
What are the 2 types of scleroderma?
Localised: morphoeaSystemic: limited and diffuse
What are the presentations for systemic sclerosis?
Limited mouth openingPoor dentitionGum recessionSecondary Sjogren’s
Adult onset Raynaud'sSwollen hands/sausage fingersTight waxy skinFatigueDysphagia
What is the treatment for systemic sclerosis?
Immunosuppression (methotrexate)Anti-fibroticVascular (ca channel blockers - nifedipine)
What are the presentations for inflammatory muscle disease?
Dry mouth and eyes due to secondary Sjogren’sDysphagiaMuscle weaknessRashRapid loss of function (need aid out of chair)
What are the 2 types of inflammaotry muscle disease?
Dermatomyositis| Polymyositis
What is the treatment for inflammatory muscle disease?
SteroidImmunosuppressivesIV Immunoglobulins
What is the definition of antiphospholipid syndrome?
Sticky blood disorder| have it or its abs
What is the clinical presentation of antiphospholipid syndrome?
Recurrent thrombosisRecurrent pregnancy lossPeculiar rash (levido reticularis)
What is the lab presentation of antiphospholipid syndrome?
Anticardiolipin antibodyLupus anticoagulantAnti-beta 2 glycoprotein
How to treat someone with antiphospholipid syndrome and what effect does this have on dental procedures?
Antiplatelets AnticoagulantsHigh bleeding risk
What are the presentations for Behcet’s disease?
Recurrent painful oral ulcers
What are the presentations for giant cell arteritis?
Jaw painJaw Cramps/claudicationsTongue pain
What are the presentations for juvenile idiopathic arthrtis?
Micrognathia| TMJ involvement
What medications give side effects such as oral ulcers?
MethotrexateSulfasalazineFetunomideMycophenolate mofetil
What medications give side effects such as dry mouth
Amitriptyline
What medications give side effects such as thrush?
Steroids| Immunosuppressants
What medications give side effects such as metallic taste?
Penicillamine| Sulfasalazine
What medications give side effects such as gum hypertrophy or staining?
Cyclosporin
What are the 2 main causes of autoimmunity?
Genetic: susceptible genes that lead to a failure of self-toleranceEnvironmental stimuli: tissue damage leading to presentation of self-antigens activating self-reactive lymphocytes
What is the definition of autoimmune disease?
A failure or breakdown of immune system that maintains tolerance to self tissues
How does the immune system change for someone who is autoimmune?
Loss of tolerance is due to abnormal selection or lack of control of self-reactive B/T cells
What is the definition of a hypersensitivity response?
A harmful immune response that may produce tissue injury or cause serious disease
What is each type of hypersensitivity reaction mediated by?
TI-III - antibodies| TIV - T cells
What type of hypersensitivity does autoimmune disease fall under?
TII-IV
What is he antibody, ligand, MoA and general name for type I hypersensitivity?
IgESoluble antigenAct mast cells and produce mediatorsAllergy
What is he antibody, ligand, MoA and general name for type II hypersensitivity?
IgG, IgMCell or matrix antigenOpsonisation, phagocytosis, complement and act of leukocytesRheumatic fever
What is he antibody, ligand and general name for type III hypersensitivity?
IgG, IgMSoluble antigenComplement, Fc receptor recruitment and act of leukocytesRA
What is he T cell variation, ligand, MoA and general name for type IV hypersensitivity?
Th1 - sol antigen TI diabetes (delayed-type)Th2 - sol antigen MS (T cell mediated)(both produce inflammatory cytokines)CTL - cell antigenTh1 - macrophage activation causing cytokine-mediated inflammTh2 - direct cell killing and cytokine mediated inflammation
Explain the process of type I hypersensitivity?
- Exposure to allergen2. Act of Tfh cells and stimulation of IgE class switching in B cells3. Production of IgE4. Binding of IgE to FceRI on mast cells5. Repeated exposure to allergen6. Activation of mast cell; releasing medicators7. Mediators such as cytokines and vasoactive amines and lipid
What are the effects of biogenic amines (histamine)
Vasodilation| Vasc leakage
What are the effects of lipid mediators (PAF and LTC4)
Bronchoconstriction intestinal hypermotility| Inflammation
What are the effects of cytokines (TNF)
Inflammation
What are the effects of cationic granule proteins?
Killing parasitic cells
What are the effects of enzymes?
Tissue damage
Explain the mechanism of action of type II hypersensitivity?
Antibody binding to antigenRecruit and activate inflammatory cells (via complement and Fc receptor) (neutrophils and macrophages)Causing tissue injury
Explain the mechanism of action of type III hypersensitivity?
Soluble immune complexes of antibodies and antigensRecruit and activate inflammatory cells (via complement and Fc receptor) (neutrophils)Causing tissue injury
What is the MoA of ‘type V’ hypersensitivity
Antibody against TSH receptorStimulates the receptor without the ligandIncrease production of thyroid hormoneHyperthyroidism
Name 4 TII hypersensitivity disease?
Autoimmune haemolytic anaemiaInsulin-resistant diabetesMyasthenia gravisGraves’ disease
Name 3 TIII hypersensitivity disease?
Systemic lupusPolyarthritisPoststreptococcal glomerulonephritis
Name 3 TIV T cell mediated hypersensitivity diseases and their antigen targets?
TI diabetes - Islet cellsRA - TII collagenMS - myelin basic protein
Theoretically, how can we treat TIV hypersensitivity?
Blockade of CD4 or MHC II molecules with blocking antibodies| Or blockage of CTLA-4 (T-cell inhibitor)
What part of genetics can influence autoimmunity?
HLA alleles
What HLA does RA have?
DR4
What HLA does Insulin-dependent diabetes have?
DR3/DR4
What HLA does MS have?
DR2
What HLA does systemic lupus have?
DR2/DR3
What gene polymorphisms in HLA can cause increased susceptibility to autoimmune disease?
IL-10
What are the potential mechanisms of environmental causes for autoimmunity?
Molecular mimicryViral/bacterial superantigensEnhanced presentation and processing of autoantigensBystander activationAct of lymphocytes by lymphotropic viruses
What is the definition of molecular mimicry?
Activation of autoreactive T cells by microbial peptides that have sufficient structural similarity to self peptide
What is the definition of viral/bacterial superantigen?
Activation of autoreactive T cells that express particular Vbeta segments
What is the definition of enhanced presentation and processing of autoantigens?
Enhanced presentation of autoantigens by APC recruited to inflammatory site, followed by priming of autoreactive lymphocytes
What is the definition of bystander activation?
Expansion of previously activated T cells at inflammatory site
What is the definition of activation of lymphocytes by lymphotropic viruses?
Viral infection of lymphocytes, such as infection of B cells with Hepatitis C virus, resulting in enhanced antibody production and formation of circulating immune complexes
What is a good example for molecular mimicry and MoA?
Rheumatic fever:| - streptococcal A antibodies bind M protein, then cross react with cardiac myosin
What are the types of autoimmune disease?
Systemic and organ specific
What is the definition of systemic autoimmune disease?
Spread throughout the body
What is the definition of organ specific autoimmune disease?
Directed towards one organ
What are the oral presentations of systemic lupus?
Mouth ulcersFacial rash (butterfly)
What is TI diabetes’ mainly mediated by and what does it attack?
By CD4 and attacks islet cells and insulin and GAD65
What are the oral presentations of oral lichen planus?
Papular skin eruptions| Chronic desquamative gingivitis
What is the treatment for oral lichen planus?
Mouthwash
What is oral lichen planus’ mainly mediated by and what does it attack?
CD8 cells| Targeting keratinocytes
What is the oral presentation of TI diabetes?
Increased caries risk
What is the definition of arthritis?
Inflammation of joints
What are the symptoms of arthritis?
PainStiffnessSwellingFunctional impairment
What are the clinical signs of arthritis?
TendernessRestriction of movementHeatRedness
What is the definition of RA?
A chronic autoimmune systemic illness characterised by a symmetrical peripheral arthritis and other systemic features, associated with joint damage
Explain the classification for RA?
Categories such as: - joint involvement- serology- acute phase reactants- duration of symptomsA score >6/10 is classified as having definite RA
What are the aetiologies for RA?
Genetic:- associated with position 70-74 of DRBeta1Environmental:- smoking- chronic infection (perio disease)
What is the pathology of RA?
Synovitis:- bone erosion- swollen and inflamed synovial membrane- inflamed synovium- inflamed joint capsule- destruction of cartilage- long term joint damage
What test to request to identify if a patient has RA?
Anti-cyclic citrullinated antibodies test (ACPA)| MRI to identify inflammation
If patient has arthritis, what should you ask about?
Where specifically the arthritis is?| If neck, be careful during extra-oral and intra-oral examinations, as neck is very tender
What are the non-specific features of systemic RA?
FatigueWeight lossAnaemia
What are the specific features of systemic RA?
Mouth, eyes, lungs, nerves, skin and kidneys
What are the long term features of systemic RA?
CV disease| Malignancy
What is a good website to assess a patient’s disease score? What are the score ranges?
das28.comDAS < 2.4 represents clinical remissionDAS > 5.1 eligibility for biologic therapy
What are the 4 therapeutic categories for the treatment of RA?
NSAIDsDisease modifying anti-rheumatic drugsBiologicsCorticosteroids
What is the definition of Disease modifying anti-rheumatic drugs (DMARD)?
A group of structurally unrelated, typical small molecule drugs which have demonstrated to have a slow onset effect on disease activity and retard disease progression, but have been associated with toxicity profiles and risk of occasional serious adverse events
Name 4 examples of DMARDs for RA?
MethotrexateSulfasalazineHydroxychloroquineLeflunomide
What is the approach for management and treatment of RA?
Early and aggressive intervention is key to obtaining optimal outcomesEffective suppression of inflammation
Why is methotrexate the golden standard?
Effective Well-toleratedCheapPeople stay on itCan be combined with DMARD or biologics
What is the definition of biologic DMARDs?
Large complex proteins which need to be given via injection, they work rapidly and are well tolerated but with important toxicities
Name 6 biologic DMARDs for RA?
TNFa inhibitors (first line)IL-1/6 inhibitorsAnti B/T cell therapiesOral kinase inhibitors
What are the side effects of biologic DMARDs?
Injection site reactionInfectionPossible malignancy
When can you use corticosteroids for RA?
Short term| In combination with other treatments for RA
What are the outcomes for RA sufferers?
50% will be unable to work due to disability within 10 years of diagnosisIncreased number of sick days75% of cases diagnosed during working life
Where to position the blood pressure cuff on the arm?
It should be over the brachial artery, above the elbow| Place the stethoscope on the artery to listen for sounds
What are the key Korotkoff sounds?
I: artery just opening after reliving of some pressure - SYSTOLICV: silent artery, artery fully open - DIASTOLIC
Process of measuring blood pressure?
- Place tourniquet over the brachial artery, above the elbow - line on tourniquet should line up with the brachial artery2. Place stethoscope over arteryInflate tourniquet until the artery is fully occluded3. Behind to deflate the tourniquet slowly and once the first sound is heard record the pressure value - this is the systolic pressure4. Continue to release the pressure from the tourniquet, until the artery is fully open and the sound has become silent - this is the diastolic pressure
How should the patient be positioned?
Arm on table| Level with heart
What is the definition of osteoporosis?
Low bone mass and microarchitectural deterioration of bone tissue
What are the risk factors for osteoporosis?
Rheumatic diseaseMalabsorptionEndocrineMedication
What is the absorption and T1/2 of bisphosphonates?
Very poor intestinal absorption50% goes to skeleton, rest excreted via kidneyLong skeletal retention, with T1/2 of 10 years
What are bisphosphonates?
Pyrophosphate analogues| 2 phosphates linked to C
What is the function of bisphosphonates?
Prevent loss of bone density and decrease risk of fractures
How do bisphosphonates work?
Stimulate osteoclast apoptosis and inhibit cholesterol synthesis pathwayThis decreases osteoclast numbers and decrease bone resorption
Chemically, how are 2nd and 3rd generation bisphosphonates different?
2nd: N side chain3rd: N heterocyclic ring
Name 3 2nd generation bisphosphonates?
AlendronateIbrandronatePamidronate
Name 2 3rd generation bisphosphonates?
Risedronate| Zoledronate
What is the definition of Medication Related Osteonecrosis of the Jaw (MRONJ)?
It is defined as exposed bone, or bone that can be probed through an intraoral or extraoral fistula, in the maxillofacial region that has persisted for more than eight weeks in patients with a history of treatment with anti-resorptive or anti-angiogenic drugs, and where there has been no history of radiation therapy to the jaw or no obvious metastatic disease to the jaws.
What are the systemic risk factors for MRONJ?
GeneticsDiseaseAgeObesityAlcoholSteroid therapyTobaccoSex
What are the medication related risk factor?
Total dose| Length of treatment
What are the local factors related to risk factors?
MicrotraumaInflamm diseaseOral surgeryOral implantology
What is the pathogenesis of MRONJ?
Inflamm/infectionMicrotraumaAltered bone remodelling or over suppression of bone resorptionANgiogenesis inhibitionSoft tissue BPs toxicityPeculiar biofilm of the oral cavityterminal vascularisation of the mandibleSuppression of immunityVit D deficiency
Risk assessment for MRONJ?
No risk - if no medsLow risk - if on meds but not previous diagnosisHigher risk - if on meds for <5 years
Dental advice for a patient with MRONJ?
Healthy diet and reducing sugary snacks and drinksExcellent oral hygieneFl toothpaste and mouthwashStop smokingLimit alcoholRegular dental check ups
What symptoms should an MRONJ patient report to the dentist?
Exposed boneLoose teethNon-healing sores or lesionsPusTinglingNumbness or altered sensationsPainSwelling
What are the treatments for established MRONJ?
SurgicalGentle debridement (best)Avoid resectionRemove sequestra
What is a medical management for MRONJ?
Teriparatide
Why is stroke relevant to dentists?
Seeing older patientsA link between oral health and risk of strokeOH poor after stroke
Risk factors at the dentists for stroke?
Invasive treatments
When do most strokes occur across the population?
75% over the age of 65
What fraction of patients die within 1 year after their stroke?
1/2
What percentage of stroke survivors become dependent on others?
50%
How many strokes does the UK have per year?
150,000
How much does stroke cost the the NHS?
8bn
What is the definition of stroke?
It is the sudden onset of focal neurological symptoms caused by ischemia or hemorrhage and lasting more than 24hrsMost strokes are ischaemic
What is the difference between a stroke and a TIA?
Symptoms usually resolve within 24hrs (usually an hour)
What is the definition of a hemorrhagic stroke?
Blood leaks into brain tissue
What’s the definition of an ischaemic stroke?
Clot stops blood supply to an area of the brain
What are the vessels of the anterior supply to the brain?
Common carotid
What are the vessels of the posterior supply to the brain?
Vertebral arteries
What do the vertebral arteries form?
Basilar artery
What does the basilar artery form?
Posterior cerebral artery
What does the internal carotid artery form?
Middle cerebral artery
What does the middle cerebral artery form?
Anterior cerebral artery
How is the posterior and anterior blood supplies of the brain connected?
Posterior communicating artery
What does the carotid system of the brain supply?
Most of the hemispheres and cortical deep white matter
What does the vertebrobasilar system of the brain supply?
Brain stem, cerebellum and occipital lobes
What is the function of the frontal lobe?
Judgement, foresight and voluntary movement| Smell
What is the function of the motor coretx?
Movement
What is the function of the sensory coretx?
Pain, heat and other sensations
What is the function of the parietal lobe?
Comprehension of language
What is the function of the temporal lobe?
Hearing| Intellectual and emotional functions
What is the function of the Occipital lobe?
Primary visual area
What is the function of the Wernicke’s area?
Speech comprehension
What is the function of the cerebellum?
Coordination
What is the function of the Brain stem?
Swallowing, breathing, heartbeat, wakefulness centre and other involuntary functions
What is the function of the Broca’s lobe?
Speech
What would occur of there is a small stroke in the deep white matter?
Major deficit as the fibres are packed closely together
What are the signs and symptoms of stroke?
Motor: clumsy or weak limbsSensory: loss of feelingSpeech: dysarthria/dysphagiaNeglect/visuospatial problemsVision: loss in one eye or hemianopiaHaze palsyAtaxia/vertigo
What does the posterior circulation supply?
PonsMidbrainHindbrainCerebellum
What are the stroke symptoms that may arise from the posterior circulation?
AtaxiaVertigoNystagmusLoss of consciousness (thrombus in basilar artery)Cardiorespiratory control
What are some conditions that present similar symptoms to stroke?
MigraineEpilepsyStructural brain lesionsMetabolic disordersvestibular disorderPsychological disordersDemyelinationMononeuropathy
Name 4 causes for a stroke?
Carotid stenosisCarotid diseaseAtrial fibrillationLacunar stroke (small vessel)
Name 2 rare causes for a stroke?
Foramen ovale hole (PFO)| Carotid dissection