FHHD Flashcards
1
Q
What is haemachromatosis
A
Excessive iron absorption in intestine causing pathological increase in iron body stores - 2/3rds will be incorporated in Hb, the rest stored in liver mainly. Once absorbed theres no mechanism to remove it. The iron stores cause liver scarring (fibrosis) + enlarged + may lead to cirrhosis.
2
Q
Explain Wilsons disease
A
Abnormally high levels of copper in the body due to genetic defect where theres a lack of removal of copper by the liver through bile = accumulation of copper = hepatitis = cirrhosis
3
Q
Keratin pearls are characteristic of…
A
Squamous cell carcinoma
Keratinisation - seen as circles or kinda like roses.
4
Q
Ground glass hepatocytes are characteristic of ..
A
Hep B induced hepatitis
They are smooth and pink
5
Q
Mallorys hyaline is seen in…
A
Alcoholic liver
Pink patches
6
Q
Describe mould fungi
A
Branching filaments (hyphae) Mass of interwoven branches are called mycelium Reproduce by spores
7
Q
Describe yeast fungi
A
Unicellular
Reproduce by budding
8
Q
What are dermatophytes
A
Fungi that colonise and digest keratin in skin (stratum corneum), nails, hair. They cause tinea infections
9
Q
What are the three genera of dermatophytes
A
Microsporum
Epidermophyton
Trichophyton
10
Q
What is saouraud agar used to culture
A
Fungal Dermatophytes - epidermophyton and microsporum
11
Q
What genus is candida from
A
Yeast
12
Q
What is the alternate term used for leukoplakia
A
Chronic hyperplastic candidosis
13
Q
Wats the alternate name for denture stomatitis + clinical features
A
Chronic atrophic candidosis
Red+ swollen+ inflamed mucosa under denture
Probs cuz denture was affecting integrity of mucous membrane underneath hence allowing prolif of fungi C.albicans
14
Q
Which two organisms cause angular cheilitis
A
Bacteria eg staph aureus, and fungi eg C.albicans.
A weakened immune system + trauma/chapped lips/excess drool salivation/ deep creases in corners of mouth allow bacteria/fungi to spread more easily.
15
Q
What is perleche a synonym of
A
Angular cheilitis
16
Q
What is maceration and what is it a predisposing factor to
A
Softening/breakdown of skin due to long term exposure to moisture.
Oral candidosos
17
Q
Use n form of chlorhexidine
A
Solution
Antibacterial and anticandidal
18
Q
Preparation form of miconazole and use
A
Topical oral gel/cream Candida species (altho have variable sensitivity) + antistaphylococcal activity
19
Q
Treatment and prevention of candidiasis:
A
3 options - amphotericin B, nystatin, azoles eg miconazole.
Prevention- remove predisposing factor eg denture
20
Q
Describe actinomyces
A
Rod shaped
Gram positive
Filamentous bacteria
Facultative anaerobe
21
Q
Describe actinomycosis
A
Mainly caused by Actinomyces israelii
Chronic infection +granulomas
Tissue destruction
Swelling
Multiple discharging sinuses in chronic case
Extensive fibrosis
Mycelia formed embedded in polysaccharide matrix containing acid fast structures- often visible to naked eye - sulphur granules - light yellow in colour
22
Q
Actinomyces treatment
A
Antibiotics eg penicillin, tetracycline
Surgical debridement reduces scarring/deformity and enhances healing and lowers recurrence incidence
23
Q
Wat is commensal
A
Org that bevegits from another withiut cauding benefit ot harm to host
24
Q
Carriage
A
Asympyonatically carring a pathogeniv organidn which can be trabsmittef to other ppl eg staph aureus in the nose
25
Pathogen
Any org capqble of causing infection
26
Oppurtnistic pathogeb
Cause disease if host is immunocomptomised or get to sotes where they dont normslly live
27
Virulence
Degree of pathegonicity
28
Fomites
Inanimate objectvwhich carries and transmits organisms eg a steam mop
29
Coagulase in staph aireus
Walling off of staph aureus from phagocytosis
30
Classic exotoxins
Heat destroyed
Neurralised by antitoxib
Hughly toxic
Actvat specifuc sites
31
Endemic
Infection Always present at constant lebel in pop or may have sessinal variation
32
Epidemic
Short term higher than normak level in population
33
Outbreak
Lovalised increase in incidence of dusease
34
Pandemic
Epidemic spreading between continents
35
Degree of infectivity
Ability to enter, muktiply, and survive inside hist
36
Active case
Clinically unwell
Whereas carrier looks well (asymptonatic) but are chronically infected and are unaware of their infection risk to others.
37
Cellulitis
Spread of infection in soft tossues - mostly caused by strep pyogenes
38
Cardinal signs of inflam
Red swollen painful hot
39
Asepsis
State of being free from living organisms
40
Antiseptic
Applied to open wounds/abrasions
| Destroys/inhibits growth of microbe
41
Gram pos bacteria
More sensituve to disinfectabt
42
Disinfection used when
```
Surfaces
Spilkages
Grossly contaminated areas
Non surgical instrument
B4 sterilisation
Dental unit wster dupplies
```
43
Sterilisation
Surgical instruments- then store them under sterile conditions
44
Prodromal stage
After the incubation period
| Symptoms arent spevific and severe yet and can still perform usual functions
45
3 main sources of infection in dental surgety
Carrier
Prodromal
Suffering from infectious disease
46
3 main ways if transmissuib in dent surgery
Contaminated instrunents
Direcr contact with russues if skin n fluids
Droplets cintainung unfectuous agent
47
Incineration
Infected waste
48
Whats eh
Oxidation potential
| Eg obligate anaerobes require low oxidation potential
49
3 facultative anaerobes
Staph
Strep
Ecoli
50
2 obligate aerobes
Neiserria
| Pseudomonas
51
Anaerobiosis
Any form of life that is sustained in the absence of oxygen
52
Describe an abscess
Forms around apices of teeth with necrotic infected root canals
Mainly caused by obligate anaerobes + oral streptococci
53
Define osteomyelitis
Inflammation n infection of usually long bones but can affect jaw bone cavity
54
Chronic marginal gingivitis
No particular species of bacterua involved - its as a result of dental plaque accumulation
55
AUG
Grey gingival pseudomembrane which can be pulled off to reveal bleeding area underneath. Loss of interdental papilla.
56
Wat organisms linked to AUG
Spirochaetes eg treponema
Prevotella intermedia
Fusobacterium
57
Organisms causing periodontitis
Porphyromonas gingivalis
Prevotella intermedia
Aggregatibacter
Cspnocytophaga
58
Orgs causing pericoronitis
Prevotella intermedia
| Fusobacterium nucleatum
59
Peri implantitis
P. Gingivalis and intermedia
60
Wat org causes actinomycosis
Actinomyces israelii
61
Wats sialadenitis
Infecrion of salivary glands
62
Orgs causing sialadenitis
Strep
Staph from nose n skin
Gram neg anaerobes too
63
Clostridium endospores adv
Allows org to survive in adverse conditions eg skin n soil
64
3 main clostridial infections
- tetanus - clostridium tetani
- botulism - clos. Botulinum
- gas gangrene - several species eg c perfringen
65
Wats the morohology of tetanus bacilli
Drumstick shape due to round terminal spores
| Can be gram stained to see this
66
Wat are the 2 things tetanus produces
Tetanospasmin (neurotoxin)
| Tetanolysin (haemolysin)
67
Where are clostridia found
Intestine
Soil
Water
Decaying plant n animal matter
68
Tetanus - 4 features
Trismus
Risus sardonicus - facial muscle spasm
Opisthotonus - backward arching of head neck spine
Resp muscke spasm
69
Describe botulism
Ingested of toxin via processed foods n canned.
Extremely potent toxins A-G
In humans type A,B,E
Blocks ach at nerve terminals = vomiting, thirst, muscle paralysis.
70
C perfringen conditions
Antibiotic associated diarrhoea
| Food poisoning
71
C difficile causes:
Antibiotic associated diarrhoea
| Pseudomembranous colitis
72
Nagler reaction
Alpha toxin of c perfringen is a lecithinase, demonstrated in egg yolk medium - a line of incubated c perfringed added to medium- seeing opacity will indicate lecithinase activity
73
Tetanus prevention
Toxoid injection to give immunity
| Or antitoxin for short term passive immunity (an immunoglobulin)
74
Tests for staph aureus
```
Based on enzyme production:
- dnase
- coagulase
- catalase
Sugar fermentation tests
- glucose
- mannitol
```
75
Septicaemia
Absorption of pathogenic bacteria and their toxins from blood into tissues causing widespread destruction
76
Epidermolytic toxin - splitting within plane of epidermis causes:
Scalded skin syndrome
Impetigo non bullous
Pemphigus neonatorun
77
Describe pustular impetigo
Vesicles- pus filled- on an erythematous base
| May also have dry crysted lesions where vesicles have burst
78
Why is scalded skin s mainly in children
Cuz neonates lack the antitoxin to the epidermolytic toxin from staph aureus
79
Wat toxin causes toxic shock syndrome
TSST-1
80
Wat condition is linked to highly absorbsnt tampons
Toxic shock syndrome
| The tampon creates conditions for bacteriak multiplication and toxin production
81
What is the name of the toxin that breaks down wbcs, released by staph aureus
Panton valentine leucocidin
82
Wats panten valentine leucocidin associated with - resistance
MRSA
83
What enzyme released by staph aureus breaks down hyaluronic acid intracellular ground substance of tissues
Hyaluronidase - spreading factor
84
Role of peptidoglycan
Inhibits inflam response
85
Protein A (staph aureus)
Binds to fc region if iGg
86
Wat is tested for in the slide test
Clumping factor - binds to fibrinogen hence looking for clumps under microscope. Plus cell surface bound coagulase which converts fibrinogen to fibrin
87
Oral strep - what type of haemolysis do they do
Alpha - partial
Or
None
88
Function of antigen |/|| and what bacterial cell wall it is found from
Streptococcus mutans
Immune modulation
Platelet aggregation
Tissue invasion
Biofilm formation - binds pellicle components
Also found in E.coli - the K antigen
89
S. Mitis species main infections:
Bacterial endocarditis
| Plaque isolated - pioneering species
90
S. Salivarious species group
Plaque pioneering specie
Mainly found on tongue
S.vestibularis - produces urease and hydrogen peroxide which can contribute to local salivary peroxidase activity and competing with pathogenic bacteria
91
Strep Anginosus - what infections does it cause
Purulent infections eg abscesses
92
Define bacterial endocarditis
Infection of endocardium inner lining of heart by microorganisms present in the blood stream
Serious life threatening condition
93
Which bacterial group id most frequently isolated from heart valve vegetations in IE
Oral streptococci
94
Wat factors make someone predisposed to IE
Congenital heart defect
Prosthetic heart valve
Heart disease
All these factors cause irregular blood flow = thrombi formation
95
How can oral bacteria cause IE
Dental manipulations may introduce the bacteria into patients blood stream from an oral infection eg periapical abscess.
96
Characteristics of strep
```
Fastidious culture requirements - complex growth media
Catalase neg
Facultative anaerobes
Cocci forming chains
Gram positive
```
97
Describe Lancefield grouping
For beta haemolytic species of streptococci which are the most frequently isolated type of strep in the body.
Groups specific carbohydrate antigens in cell walls - useful as a specie marker.
They use nitrous acid to extract the specific antigen from the bacterial cell wall - precipitin reaction. And lancefield group antisera used to identify the antigen group.
An antigen/antiserum complex will form and be seen as a line of precipitation
98
Which type of strep cannot be lance field grouped
Viridans strep (oral)
99
Where is the M protein surface antigen found
S.pyogene surface
It is an antigen
100
Features of M protein
Heat n acid stable
Antiphagocytic property
Antibody to it contributes to immunity
101
Wat do o streptolysins breakdown
Platelets
Rbc
Cardiac tissue
Neutrophils
102
Where are o and s streptolysins found
Beta haemolytic strep
| Eg s.pyogenes
103
S streptolysin
Breaks down rbcs
White blood cells (leucocidal)
Not inactivated by oxygen whereas o toxin is
104
What are the two important beta haemolytics strep pathogens
S.pyogene
| S.agalactiae
105
What organisms is bacitracin sensitive and explain wat this means
Strep pyogenes
Bacitracin is a peptide that interferes with cell wall and peotidoglycan synthesis - hence will see a zone of inhibition when placed on blood agar
106
Which bacteria are optochin sensitive and what can u use this to differentiate fron
S.pneumonia - hence will see zone of inhibition. Since pneumonia is alpha haemolytic u can use this test to differentiate it from other alpha haem strep eg viridans
107
Wats conjunctiva
Lines the surface of the eye and eyelids
108
Complications of gonorrhea
Salpingitis
Epididymitis
Purulent conjunctiva of newborn = blindness
Disseminated - fever, joint pain, skin lesions
109
Function of neisseria gono fimbriae/pilli
Attachment
| Resistance to phagocytosis
110
Can we do serology for neisseria gonorrhea
Nah cuz its very heterogeneous serologically
111
Treatment for gonor
Antibiotics - penicillin - slow release IM, also tetraycline and ceftriaxone used
112
How does treponema pallidum enter body
Penetration of intact mucosa
| Abraded skin
113
Whats a chancre
Firm
Painless
Ulcerated nodule
Occurs in primary syphilis
114
Secondary syphilis
Rash - macular or pustular
Condylomata lata - genital warts
Mucous patch/snail track ulcer
Lesions are highly infectious
115
Describe latent syphilis
No clinical features- so no lesions or rash or warts or ulcers
Butt serology persists - so might still be present in blood (remember its disseminated at secondary stage)
Then from latency it may reactivate to secondary stage - relapse
116
Describe a mucous patch/snail track ulcer
Oral ulceration that occurs in secondary syphilis whereby it has spread systemically and caused a grey shedding superficial ulcer
117
What type of bacteria are present in large intestine
Strict anaerobes
118
Wats dysentery
Abdominal cramps
Pus and blood in stool
Due to bacterial invasion of tissues in intestine causing necrosis
119
List the gram negative bacilli present in the large intestine
Enterobacteriacea: E.coli, klebsiella, shigella, salmonella
120
Wat are pili n wat do they do
Aka fimbriae
Hair like processes on surface of bacteria
Adhesion to cells
Transfer of DNA during conjugation (wen bacteria unite to transfer their dna)
121
Wat do mycolic acids do in mycobacterium
They are present in cell wall, they cross link arabinose and galsctose to form arabinogalactan layer.
Presence of mycolic acid layer (lipid) makes mycobacterium acid fast hence cant be gram stained since this layer covers the peptidoglycan layer beneath
122
Describe features of mycobacterium
Aerobic (they cause tb which commonly occurs in lungs which is has a lot of oxygen hence will obviously be aerobic)
Non motile
Rods - straight or curved
123
What colour do acid fast bacilli appear with the ziehl neelsen stain
Red
| Others appear green
124
What culture medium is used to grow tubercle bacilli and how will they appear
Lowenstein Jensen slopes (LJ)
Rough buff n tough yellow colonies
However it takes up to 8 weeks for this to grow so need to use faster detection methods
125
What is tb
A chronic granulomatous disease
126
What type of hypersensitivity reaction is tb
Type 4- cell mediated
127
Wat specimens can be examined for tb
Sputum
Urine
Pleural fluid
Csf
128
IE effects which places
Heart valves
Septal defect
Mural endocardium in a left ventricular aneurysm
129
Whats the treatment drugs for tb
Isoniazid
| Rifampicin
130
Causes of dentoalveolar abscess
Oral strep/staph and mainly other oral obligate anaerobes:
- prevotella
- veillonella
- fusobacterium
131
Describe herpetic stomatitis
```
Caused by HS1 mainly but can be caused by hsv2.
Blisters
Ulcers
Bleeding
Difficulty eating
Swallowing
Redness of all gingiva
```
132
Give an example of short term disturbance of oral cavity n long term
St - short term antibiotic therapy (causing candida over growth)
Lt- loss of salivary secretion eg due to sjogrens syndrome
133
What mouthwash can you use for herpetic gingivostomatitis
```
Tetracycline
Swallowed after
Must complete full course
Broad spectrum antibiotic
Do not give to ppl with renal disease - can exacerbate it, pregnancy/breastfeeding
```
134
Which two first line antibiotics are used for dental infections
Metronidazole - inc activity against anaerobic bacteria - avoid alcohol
Amoxycillin - broad spectrum antibiotic- interferes with cell wall synthesis- predisposes to candidiasis
135
Features of different antifungals
Amphotericin - lozenge- not absorbed by gut
Nystatin - also not absorbed by gut
Miconazole - cream or gel - applied to dentures- adv is tht u can keep dentures in. Drug is absorbed. Interaction warfarin.
136
Wat antiviral is used for herpes infections
Aciclovir - needs to be used in initial infection n frequent risk dosage
Topical - herpes labialis - the application at prodromal stage
Systemic - for health care workers who are treating immunicompromised patients
Higher dose used for vzv (shingles)
137
Wats the gold standard
A diagnostic test that is considered most accurate
| Eg culture is considered the gold standard
138
Identifying fungi
Cotton blue stain - microscopy
| Growth on sabourauds agar
139
Wats the purpose of oxidase
Enzyme that allows respiration - found in bacteria using o2 as an electron acceptor eg Neisseria - aerobes and facultative anaerobes
140
Explain oxidase test
Dyes that act as electron acceptor , become purple when oxidised (losing electrons) eg cytochrome c becomes oxidised as electrons pass to o2
141
Wats MacConkey agar used for
Detecting lactose fermenting (pink) orgs n non fermenting (yellow)
Eg e.coli n salmonella
142
Wen is serology mainly used
Viral infection
| Difficult to grow presumptive bacteria
143
Wats tegument
Cytoplasm area of herpes virus which contains virally encoded proteins n enzymes for replication
144
Wats nucleocapsid
Surrounds the genome inside herpes virus cell
145
Can herpes spread via dry surfaces
No, cuz they have a fragile lipid envelope sensitive to acids etc, once envelope is damaged virus isnt infectious - fluids only
146
Describe herpetic whitlow
Manual contact of an infected lesion causing infection and abscess of fingers and hands = red, swollen, painful, may form blister (fluid filled) which may burst and crust over.
147
List the conditions caused by HSV
```
Herpetic whitlow
Eczema herpeticus
Hsv prostatitis
Hsv encephalitis
Hsv meningitis
```
148
Hsv encephalitis
Cerebral dysfunction
Temporal lobes damaged
Blood in csf
Seizures possible
149
Hsv chemotherapy:
Gamma globulins
Amantadine
Rifampicin
Reverse transcriptase inhibitors
150
Describe nucleoside analog drugs
Eg aciclovir, famciclovir, valaciclovir
| Only act on cells containing thymidine kinase - replicating - therefore rlly specific in their action.
151
How is vzv transmitted
Aerosols - droplets inhaled
| Skin contact
152
Clinical pres of chicken pox
Fever
Rash on skin - vesicular /pustular/scab
Mucous membeane ulcers on hard palate with red halo
153
Complications of VZV
Encephalitis (like hsv)
Secondary infection- bronchopneumonia (infects bronchi)
Guillain barre syndrome - body immune system attacks nerve cells = myelin damage, rapid onset muscle weakness n pain - PNS
Traverse myelitis - inflammation of spinal cord - CNS
154
Describe Ramsay Hunt syndrome
Caused by VZV infecting a motor nerve - affects geniculate ganglion of CNV|| (facial nerve) ipsilateral facial paralysis LMN lesion - f palsy
Rash in external ear
Loss of taste in ant 2/3 tongue
155
What condition would you find downey cells in
EBV infection - glandular fever/infectious mononucleosis
156
Clinical symptoms of EBV
```
Fever
Enlarged lymph nodes
Pharyngitis
Fatigue
Pain
Rash
Oral ulcerations similar ANUG
Petechiae in hard palate
Oral hairy leukoplakia
Gingival bleeding
Swollen tonsils
Enlarged liver/spleen
```
157
What type of cells do ebv infect
Cells containing c3d complement receptor on surface - B lynphocytes and Oro/nasopharync epithelial cells.
158
Describe burkitts lymphoma
Tumour of lymphatic system caused by EBV
B lymphocytes infected and proliferate into a tumour mass
Non hodgekins lymphoma
Africa and children
Mainly jaw n abdomen affected
159
Complications of ebv
Lymphoma may spread to bone marrow = neutropenia, thrombocytopenia, anaemia
Could infect other organs- brain, liver, lungs
Breathing difficulties due to swollen tonsils
160
Ebv treatment
Cant use acyclovir cuz it doesn't use thymidine kinase
No drugs available
Gland F: dont prescribe amoxicillin (red rash), bed rest n antipyretics, hospitalise if liver/spleen involved
161
Which condition has dane particles in fluid n right hypochondral pain
Hep B
162
Wat 3 things can be detected in hepB
E antigen (HBeAg)
S antigen
Viral dna polymerase
163
Treatment for hepB
Lamivudine- RT inhibitor
| Interferon - slows growth of virus
164
Which two hep viruses are non enveloped
A n E
165
Describe replication of Hep B
Rna intermediate used by RT to replicate DNA from it
| High mutation rate but small genome limits genetic variability
166
True or F: hep c can be transmitted sexually n vertically
False
167
How does AIDS reduce immune response
Infects CD4+ t cells and macrophages = reduced numbers
Acute - t cytoxic cells kill infected cells
Chronic - immune system gradually loses ability to generate new t cells
= oppurtunistic infections
168
Key cause of chronic bronchitis and emphysema
SMOKING
169
Pathological def of emphysema
Perm dilation of airspaces distal to terminal bronchioles
170
Wat metaplasia occurs in barrets oesophagis
Squam cell epith to columnar
171
Where does krukenberg tumour spread from
Gastric carcinoma
172
Jaundice definition
Raised serum bilirubin with bilirubin deposition in tissues
173
Wats asterixis n wen does it occur
Hand tremor when wrist is extended
174
Wats phage typing
Used to identify strains of bacteria. Bacterua culture are plated, different phages added to dofferent areas of plate. Plaque formation indicates susceptibikity to phage.
175
Which virus switches off p53 and wat is p53
Human papilloma virus
P53 = tumour suppressor gene - apoptosis of abnormal cells
176
Polymorphisn
Changes in dna in population due to natural selection
177
Wats sporadic cancer
Not due to inherited changes
178
Role of retinoblastoma tumour suppressor gene
Important for transition from g1 to s phase (growth to replication of chromosomes)
179
Myc gene
Enhancer sequence moved towards it = burkitts lymphoma
180
Philadelphia chromosome
Translocation of c22 and 9 = chronic myelogenous leukemia - abnormal n increased prolif of myeloid stem cells in bone marrow
181
Wat type is brca1 n 2
Tumour suppresspr genes - caretaker type - dna repair n regulation in response to DNA damage
