05 May 2009

Human papilloma Viruse(HPV)



Human papilloma Viruse(HPV)
Presentation By:Nathalia Cruz

What is a Virus?
* Exceptionally simple living microbes.
* Contain a single type of nucleic acid (DNA or RNA) and a protein coat.
* Obligatory intracellular parasites.
* Range from 20 to 14.000 nm in length.
* It’s classification is based on type of nucleic acid, strategy for replication, and morphology

HUMAN PAPILLOMA VIRUS

* HPV is the virus that causes warts.
* More than 100 different kinds, 30-some of this cause genital HPV.
* Spread by sexual contact or from mother to baby.
* Genital warts appear 6 weeks to 8 months after contact with an HPV infected person.
* The most common sexually transmitted disease worldwide.
* Certain types of HPV are linked with cervical cancer.
* Divided into 2 subcategories: Genital Warts and Cervical Dysplasia.
* Most people do not know they have it.
* There are high risk and low risk types of it.

HISTORY

* The papillomaviruses are part of the PAPOVAVIRIDAE family of DNA tumor viruses.
* First discovered in the early 40’s.
* Gained notoriety in the early 80’s when it was discovered that some types of HPV caused cervical cancer.

MORPHOLOGY

* Papilloma virus genome is circular covalently closed double stranded DNA of about 8 kbp.
* All PV genes are coded in one of the 2 DNA strands utilizing the alternative splicing for the individual expression of each gene.
* Papillomavirus expression is characterized by a large array of mRNAs cells coding for different genes.
* 55 nm in diameter.

APPEARANCE
MECHANISM OF INFECTION
* All PV exhibit extreme specificity for infection on epithelial cells.
* The papillomavirus epitheliotrophy resides in the interaction of specific transmission factors with the viral regulatory region LCR.
* The infection normally results in hyperproliferation of the host cell and may lead to transformation and immortalization.

GENITAL WARTS

* Sometimes called condylomata acuminata.
* Are soft, moist or flesh colored, and appear in the genital area within weeks or months after infection.
* Sometimes appear in clusters and are either raised or flat, small or large.
* Women: appear in the vulva, cervix, vagina and anus.
* Men: Can appear on the scrotum or penis.

LIFE CYCLE (HPV-16)

* Starts with the infection of the host cell.
* The virus DNA is released within the nucleus
* Numerous cellular transcription factors interact with the non-coding viral regulatory region (LCR), starting transcription of the two hpv-16 transforming early genes (E6 and E7).
* The transforming proteins interact with the cellular antioncogenic regulator p53 disrupting the cell cycle.

LIFE CYCLE
HPV TYPES
HPV GENOMIC ORGANIZATION
HOW HPV CAUSES CANCER
* HPV DNA integrates into the host genome.
* The proteins E6 and E7 are produced from the resultant DNA.
* E6 binds and degrades p53 (a tumor suppressor gene).
* If the DNA is altered, the cell keeps replicating. The mutation rate of the cell increases.
* E7 binds and degrades retinoblastoma (another tumor suppressor gene).
* Retinoblastoma normally keeps the cell from growing too fast or responding to growth stimulators. This inhibitory factor is now lost.
* without these two mechanisms to slow down cell growth and prevent mutation. . .
* Malignant Transformation Occurs.


HPV TREATMENT

* Genital warts can be treated by a doctor and by different methods.
* Podofilox gel: A patient-applied treatment for external genital warts.
* Imiquimod cream: A patient-applied treatment.
* Chemical treatments (including trichloracetic acid and podophyllin), which must be applied by a trained health care provider to destroy warts.
* Cryotherapy: Uses liquid nitrogen to freeze off the warts.
* Laser therapy: Uses a laser beam or intense lights to destroy the warts.
* Electrosurgery: Uses and electric current to burn off the warts.
* Surgery: Can cut away the wart in one office visit .
* Interferon: an antiviral drug, which can be injected directly into warts.

CURE

* There is currently no cure for human papillomavirus.
* Once an individual is infected, he or she carries the virus for life even if genital warts are removed.
* The development of a vaccine against HPV is under way, but is still not available.
* If left untreated, some genital warts may regress on their own.


SOURCES

* http://cinvestav.mx/genetica/MyFiles/Papillomavirus/PAPepi.html
* http://www.life.umd.edu/classroom/bsci424/BSCI223WebSiteFiles/LectureList.htm#LectureList
* WWW.STDSERVICES.ON.NET/STD/WARTS
* http://www.ashastd.org/stdfaqs/hpv.html
* http://www.niaid.nih.gov/factsheets/stdhpv.htm

Human papilloma Viruse.ppt

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Dental Management of Patients with Cardiac Arrhythmias



Dental Management of Patients with Cardiac Arrhythmias
Presentation by:Donald Falace, DMD
Oral Diagnosis and Oral Medicine
UK College of Dentistry

Conduction System of the Heart
* Begins with depolarization of the SA (sinus) node
* Impulse then spreads to the atria resulting in..
* Contraction of atria with blood being pumped out of the atria
* Then the AV node depolarizes and…
* Impulse spreads to the bundle of His and then to right and left bundle branches resulting in…
* Contraction of ventricles and blood being pumped out of the ventricles

Electrocardiogram
* P wave = atrial depolarization
* QRS wave = ventricular depolarization
* T wave = ventricular depolarization
* Atrial depolarization is masked by the QRS wave

Terminology

* Sinus rhythm: normal heart rhythm originating in the SA (sinus) node; 60-100 beats/minute
o Tachycardia: rapid heart rate greater than 100 beats per minute
o Bradycardia: slow heart rate less that 60 beats per minute
* Supraventricular arrhythmias: arrhythmias originating in areas other than the normal ventricular pathways (such as from the atria, AV node, or an accessory pathway)
* Premature ventricular contraction (PVC): a ventricular contraction (QRS wave) not preceded by an atrial contraction (P wave) due to an abnormal electrical focus in the ventricles; found in normal and abnormal patients
* Heart block: an interruption in the normal electrical conduction between the atria and ventricles so that the atria and ventricles beat independently
* Ectopic pacemaker: appearance of a new and abnormal pacemaker
* Fibrillation: a chaotic heart beat

Classification of Arrhythmias
Classified by Site of Origin

o Supraventricular: arrhythmias that arise above the bifurcation of the His bundle (atria) and broadly categorized into
+ Tachyarrhythmias (too fast)
+ Bradyarrhythmias (too slow)
o Ventricular: arise below the bifurcation of the His bundle (ventricles)

Supraventricular Arrhythmias
* Sinus nodal disturbances
o Sinus arrhythmia (resp)
o Sinus tachycardia (>100)
o Sinus bradycardia (<60)
* Disturbances of atrial rhythm
o Premature atrial complexes (ectopic foci)
o Atrial flutter (250-350)
o Atrial fibrillation (350-600)
o Atrial tachycardias (150-200)
* Tachycardias involving the atrioventricular (AV) junction (accessory AV pathways)
o Pre-excitation syndrome (Wolff-Parkinson-White)
* Heart block (conduction impairment)
o First degree
o Second degree
+ Mobitz type I (Wennckebach)
+ Mobitz type II
o Third degree

Ventricular Arrhythmias
* Premature ventricular complexes (PVC’s; very common)
o Occur alone
o Every other (bigeminy)
o Every third (trigeminy)
o Two consecutive (couplet)
o Three consecutive (ventricular tachycardia)
* Ventricular tachycardia
o Three or more PVC’s in a row
* Ventricular fibrillation

Atrial Fibrillation

* Most common sustained arrhythmia
* Rapid, chaotic atrial activity; 350-600 beats per minute
* Disagreeable palpitations or discomfort, weakness, faintness, breathlessness; stroke
* Usually associated with RHD, HBP, IHD, thyrotoxicosis
* May be found in otherwise healthy individuals
* Prone to thromboembolism, therefore, will often be on warfarin

Significance and Risk of Arrhythmias

* ACC/AHA Guideline Update for Perioperative Cardiovascular Risk Evaluation for Non-Cardiac Surgery (Circulation 2002;105:1257-1267)
* Major Risk:
o High grade A-V block
o Symptomatic ventricular arrhythmias in the presence of underlying heart disease
o Supraventricular arrhythmias with uncontrolled ventricular rate
* Intermediate Risk:
o Abnormal Q waves (marker of previous MI)
* Minor Risk:
o Abnormal ECG (LVH, L-BBB, St-T abnormalities)
o Rhythm other than sinus


Diagnosis of Arrhythmias
Pulse
Physical exam
Electrocardiogram
Stress test
Echocardiogram
Holter monitor
Event recorder
Arrhythmias
* Signs
* Symptoms

Medical Management of Arrhythmias
Antiarrhythmic Drugs
Potential Drug Concerns
Implanted Pacemaker
Placement/Functioning of Pacemaker
Implanted Defibrillator
Pacemakers/Defibrillators
Cardioversion
Surgical Ablation
Dental Management Considerations for Patients With Arrhythmias

* ID patients with significant arrhythmias; must rely on medical history; obtain medical consult if any question
* Consult with physician if patient is symptomatic (frequent palpitations, chest pain, dizziness, shortness of breath)
* Avoid elective care in patients with significant arrhythmias or with uncontrolled or poorly controlled arrhythmias
* Avoid epinephrine in uncontrolled or poorly controlled patients and in patients taking digitalis
* Avoid lidocaine in patients taking amiodarone
* With stable (controlled) arrhythmia, may use vasoconstrictor in modest amounts if needed; treat as normal patient
* Implement stress management protocol as needed
* Be mindful of anticoagulant therapy; most treatment permissible if INR is within the therapeutic range)
* Watch for digitalis toxicity (increased salivation)
* Avoid electrical interference with pacemaker

Dental Management of Patients with Cardiac Arrhythmias.ppt

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Dermatologic Surgery



Dermatologic Surgery
Presentation lecture by:Kristy P. Gilbert, D.O.

Introduction
* Derm surgery increasing in complexity
* Aesthetic and Laser procedures
* Plastic surgery – blepharoplasty, facelifts, liposuction
* Mohs micrographic surgery
* Increasing emphasis on patient safety, documentation, and accreditation.

Basics: Pre-Op Evaluation
* Drug Allergies
* Meds: Coumadin, Plavix, ASA.
* Pacemaker? Defibrillator?
* MVP, Endocarditis, Prosthetics?
* Informed Consent, photographic consent, risks v. benefits and options must all be discussed & signed
* OTC and Herbals…..

Past medical history

* Factors that will affect wound healing
* Prophylactic antibiotics
* Risks for scarring
* Risks for bleeding

Factors that will affect wound healing
* Advanced age
* Nutritional status
* Diabetes
* Immunosuppressive drugs
* Smoking
* Critically ill patients, HIV
* Atherosclerosis, PVD

Prophylactic Antibiotics
* Contaminated or “dirty” wounds benefit, not clean wounds
* Indications
* ear, nose mouth, hand foot, axilla, genitalia (“dirty” areas)
- Artificial Heart Valve
- Artificial Joint Replacement < 6 months
- Past history Endocarditis, Rheumatic Fever
* Mitral Valve Prolapse WITH holosystolic murmur
* Immunocompromised

Antibiotic Prophylaxis:
Risks for scarring
* Location: upper chest, back, shoulders, extremities
* Personal hx scarring: i.e. keloids, hypertrophic scars
* Medications: isotretinoin in past 12 mo. Or Vitamin A or E use

ASA/NSAID containing drugs

* There are about 160 of them
* Most are OTC
* Patients don’t think of these as drugs because they are not prescriptions.

ASA/NSAID containing drugs

* Aspirin
* Irreversibly acetylates platelet COX reducing PG and thromboxane A2 synthesis therefore platelets inhibited for their lifetime (7-10days)
* For this reason, must be D/Ced 7-10 d pre-op
* NSAIDs
- Reversibly inhibit COX therefore less clinical effect
Other drugs affecting platelets

* Production
* Myelosuppressive agents, ethanol, estrogens, thiazides
* Destruction
* Abx: sulfathiazole; quinine, ASA, dig, methyldopa
* Function
- ASA, dipyridamole, ethanol, heparin, NSAIDS, plavix, ticlopidine, herbal supplements

Herbal Supplements that inhibit coagulation….

* MOST COMMON: Fish Oils, Garlic, Gingko, Ginseng, Chinese Herbal/Green Teas, Vitamin E
* Alfalfa, Capsicum, Celery, Chamomile, Dong quai, Fenugreek, Feverfew, Ginger, Horseradish, Huang qui, Kava kava, Licorice, Passionflower, Red Clover.

Local anesthesia
* Ideal properties
* Rapid onset
* Long duration of action
* Lack of toxicity
* Water solubility
* Structure & function
* Aromatic portion= lipophilic= potency
* Amine= hydrophilic= solubility
* Intermediate chain- determines class: i.e. ester, amide AND most importantly- this determines route of excretion and metabolism
* MOA = blocks movement of Na+ influx across membrane thereby blocking depolarization

Local Anesthesia Categories
* Esthers:
* Procaine (novocaine)
* Chloroprocaine (nesacaine)
* Cocaine
* Tetracaine
* Benzocaine
* Amides

-Lidocaine (xylocaine)
* Mepivacaine (carbocaine)
* Prilocaine (citanest)
* Etidocaine(durantest)
* Bupivicaine (marcaine) = the LONGEST acting
* Nupercaine
* Pearl: fears of epinephrine induced necrosis at distal sites (nose, ears, penis, toes, fingertips) are largely unfounded.
* Pitfalls: patients with severe peripheral vascular disease, diabetic angiopathy and Raynaud’s phenomenon may be exceptions to the rule.
* Contraindications to epinephrine in anesthsia:

-severe HTN, pheochromocytoma, HyperTH, severe vascular ds, bradycardia “ABSOLUTE”
-pregnancy, MAO inhibitors, narrow angle glaucoma “RELATIVE”
* Maximum dosage
* Insert needle at a 30 degree angle and slowly retract the needle as you inject the anesthetic. When the tissue blanches you are at the right level.
* Always best to try to avoid too many sticks, if your doing a larger area, each re-stick should be into an area that has already been anesthetised

Pain Control
* Local Anesthesia:
* INJECT SLOWLY: Decreases pain more than warming or adding bicarbonate.
* Distraction techniques useful as well – pinching skin during injection, vibrating pen, etc.
* For pediatric patients, let them sit in the lobby with ELA-Max or EMLA under occlusion for 30 min.- 1 hr. Your eardrums will thank you.

Surgical Cleansers
* Clean Procedures:
* Isopropyl alcohol
o weak antimicrobial
o most commonly used agent for shave biopsies
* Hydrogen peroxide
o no significant antiseptic properties
o not suitable for sterile procedures

Surgical Cleansers: Sterile

* Betadine
o irritating to skin, residual color
o must dry completely to be antimicrobial
o absorbed by premature infants
* Chlorhexidine (Hibiclens)
o keratitis if it gets in the eyes
* Hexachlorophene (pHisoHex)
o not on women or children due to neurotoxicity and teratogenicity

Common Procedures

* Shave Biopsy
* Punch Biopsy
* Excisional Biopsy
* Cryosurgery

Shave biopsy
* Best suited to pedunculated, papular or otherwise elevated lesions but may be used for macular lesions.
* Simple
* Quick
* Satisfactory cosmetic result
* Adequate biopsy tissue for diagnosis
* Sterile #15 blade
* 4x4’s
* Drysol solution
* Sterile Q-tips
* Path container
* Gillette Blue Blade Razor cut in half, bends to follow contour

Shave Biopsy - skin tension
Shave Biopsy - flush w/ surface
Endpoint is “pinpoint bleeding”
Indicates you are at the level of the papillary dermis, minimal scarring

* Stay superficial for minimal scarring.
* Pink atrophic area has a full year to heal.
* Upper chest and back scars no matter what you do.
Punch Biopsy
* Most common use is for skin biopsy
* Can excise small lesions
* Treats acne scars
* Hair transplantation
* May stretch skin perpendicular to skin tension lines to create elliptical defect and avoid “dog ears”
* Sterile OR clean procedure
* 3 or 4 mm punch is standard
* 4x4s, Drysol, Q-tips
* Needle driver, forceps
* Suture
* Path specimen bottle
* Twist punch tool until buried to the hub*
* *Caveat: Have a firm grasp of anatomy and skin thickness in the area you are punching before you punch it.
* Finger tendons, facial and neck structures.
* KEY: do not crush tissue when removing it from the biopsy site.
* Crush artifact makes pathologic interpretation difficult to impossible.
* Some pull it out using the suture needle as this method is atraumatic.


Hemostasis
* Chemical
* Electrical
* Physical

Chemical Hemostasis
* Drysol
* Aluminum Chloride
* Quick, easy, cheap.
* Q-tip application.
* No odor or discoloration.
* Good for superficial biopsy - shave.
* Monsel’s solution.
* 20% ferric subsulfate.
* Cheap, easy to use.
* Risk of tattooing.
* Superficial only!
* Caustic, may destroy connective tissue if sutured into wound.

Electrosurgery
Electrosurgery- definitions

* Electrosurgery- passing high frequency alternating current (AC) thru the tissue
* Electrocautery- electrically heated metal element applied to tissue; transfers heat but does not transfer current thru tissue
* Electrolysis- low direct current (DC) passed thru tissue b/w 2 electrodes; chemical reaction occurs @ one electrode
* Diathermy- the process of heat production and tissue necrosis due to electrosurgery
* Monoterminal= one connection b/w device and pt. (i.e. electrodessication, electrofulgration, epilation, hyfercation)
* Biterminal= 2 contacts b/w device and pt. such as a ground plate (i.e. electrocoagulation, electrosection)

Electrodessication/Electrofulguration

* Electrodessication – tip touches tissue
* Electrofulguration – 1-2mm separation between tip and tissue
* High voltage and low amperage limits depth of destruction
* Monoterminal current – no grounding required

Electro-epilation

* Follicular destruction
* AKA Electrolysis
* Chemical reaction at electrode tip causes production of sodium hydroxide (lye) at the hair root – works without scarring.
* Takes 1 minute per follicle, very slow.
* Largely replaced by laser hair removal.

Electrodessication

* LOW POWER:
* Facial telangiectasias
* Syringomas
* HIGH POWER:
* SK, Skin Tags, VV
* ED&C: BCC & SCC under 2 cm, 2-3 cycles
* Hemostasis during excisional surgery.

Electrosection

* “Cutting Current”, Radio-Frequency Ablation
* Biterminal current produced by vacuum tube is similar in form to radiowaves
* Active electrode is cool
* Tissue disruption occurs in response to the wave at the point of contact.
* Minimal trauma, excellent hemostasis.
* “Custom” attachments: wire loops, balls, needles, scalpels.
* i.e. tx of rhynophyma

THERMAL CAUTERY
Electrosurgery and pacemakers
* Published debate
* Standard of care tends to be use of only electrocautery
* Most modern pacemakers operate in a demand mode, requiring sensing and output circuits which can be interupted by high frequency electrosurgery

Curettage
ED&C
Cryosurgery
Cryosurgery delivery systems
Cryosurgery complications
Classic atrophic hypopigmented cryosurgery scars……
Excisions- margins
Mask Area of Face
Always consider the anatomy!
Branches of the facial nerve
Facial Nerve Damage
Excision: Instruments
Webster Gillies
BROWN ADSON FORCEPS – HEAVY TISSUES
CASTROVIEJO FORCEPS – DELICATE TISSUES
IDEAL FOR FLAPS, CUTTING THICK, LESS DELICATE TISSUE
Absorbable Suture
Non Absorbable Suture
SIMPLE INTERRUPTED
VERTICAL MATTRESS
CORNER STITCH
HORIZONTAL MATTRESS
DEEP SUTURES
RUNNING SUBCUTANEOUS
RUNNING SUBCUTICULAR
Mohs Surgery
Mohs- indications

* Recurrent or persistent tumor
* Anatomic location
* Embryonic fusion planes
* Nasolabial folds
* Columella of nose
* Pre- auricular, post-auricular sulcus
* Conservation of tissue impt.
* eyelids, nose, lips, ears, genitalia
* Size
* >1cm on head
* >2cm on trunk & extremities
* Special considerations
* Very young/ old
* Immunocompromised
* Unusual tumors
* Pt or family anxiety
* Poorly defined borders
* Scar carcinoma
* Major histo indications
* BCC subtypes
* Morpheaform
* Adenoid
* Superficial multifocal
* Perineural
* SCC subtypes
* Poorly differentiated
* Acantholytic
* Perineural
* Basosquamous
* Microcystic Adenexal
* DFSP
* Merkel cell
* Malignant fibrous histiocytoma
* Lentigo maligna
* Rowe et al reviewed literature since 1947
* 5 year recurrence rates primary BCC

General Surgical Complications
* Hematoma –
* usu 24-48 hrs post-op
* no evidence that ASA, NSAID or COUMADIN increases risk of hematoma
* Open and evacuate clot if necessary
* Gentle heat may facilitate reabsorption
* Bleeding
* Intraoperative control imperative
* Post-op: dressings, minimize post-op movement/activities
* ? d/c anticoagulants
* Infection –
* Main contamination period is peri-operative
* Pain, warmth, erythema, swelling, D/C, fever, chills, malaise
* Can culture, Irrigate, daily wound care, abx 7-10 days
* Dehiscence – from infection, trauma, poor surgical technique, excessive movement
* Necrosis – high tension in sutures or wound edges, poor flap design.

Avoiding Surgical Complications
* Aseptic technique
* Meticulous hemostasis
* Wide undermining
* Good surgical planning

Advancement flaps
* Primary movement is straight across the primary defect
* Essentially a large ellipse/ fusiform closure
* Types: O-H, O-T, V-Y, island pedicle
* Locations:

-Unilateral- anywhere
-Bilateral- forehead, eyebrow, upper lip, upper nose, chin
Rotation flaps

* Primary movement is arc-like or rotary
* Tension distributed away from primary defect to secondary defect
* Tension decreased by increasing length
* Recommended locations:
* Scalp, forehead, chin, cheek
Transposition flaps

* Movement of flap results in crossing intervening skin to reach defect
* Tension completely redirected from primary to secondary defect
* Creates larger secondary defect than other flaps
* Good for defects near free margin
Cutaneous Laser Surgery

* Light Amplification by Stimulated Emission of Radiation
* Light limited to one WAVELENGTH
* CHROMOPHORES are substances that preferentially absorb one WAVELENGTH
* Examples: water, Hgb, melanin
* HEAT created = “Selective Thermolysis”

Argon Laser

* Vascular and pigmented lesions
* 488 to 514 nm wavelength
* These are NOT the wavelengths specific to Hgb and melanin, therefore damage to surrounding tissue significant, possibly leading to scarring and hypopigmentation.
* Has fallen out of favor
Flashlamp Pumped Pulsed Dye
Q switched Ruby

Dermatologic Surgery.ppt

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