MISC Flashcards

1
Q

What is AIDS?

A

Acquired Immunodeficiency syndrome–> Late stage HIV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is HIV

A

Human immunodeficiency virus: An RNA retrovirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the most common type of HIV?

A

HIV-1

HIV-2 confined to West Africa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does the HIV virus do?

A

Enters and destroys CD4 T helper cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does HIV enter cells?

A

Via the GP120 envelope glycoprotein on its surface.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What happens to the infected CD4 cells?

A

They migrate to lymphoid tissue where the virus replicates, producing billions of new virions which are released and go on to infect new CD4 cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a virion?

A

An entire virus particle, consisting of a capsid (outer protein shell) and inner core of DNA or RNA/

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the structure of HIV?

A

Spherical RNA lentivirus. Envelope covered in glycoproteins gp120 and gp41 contains matrix with nucleus held inside the capsid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does HIV’s capsid contain?

A

Two enzymes essential for replication (reverse transcriptase and integrase) and two strands of RNA.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What cells does HIV infect?

A

Cells with CD4 receptors on their surface: T cells, monocytes, macrophages and dendritic cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does HIV attach and enter immune cells?

A

The gp120 spikes lock onto the CD4 receptor and another co-receptor (CCR5 or CXCR4). The gp41 protein is then used to fuse the HIV envelope to the cell wall, allowing the capsid to enter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens when HIV RNA enters the immune cell?

A

It must be reverse transcribed into proviral DNA before it can be integrated into the hosts DNA. This is done using reverse transcriptase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens after HIV RNA has been converted into DNA?

A

HIV’s integrase enzyme attaches itself to the end of the proviral DNA strands and it passes through the wall of the cell nucleus and binds to the host cells DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a latently infected cell?

A

When the proviral DNA has integrated into the host cells DNA, HIV remains dormant for a period.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When do infected CD4 cells become activated?

A

If they encounter an infectious agent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens when the infected cell becomes active?

A

HIV uses the hosts RNA polymerase to make new HIV RNA which are split into pieces using HIV’s protease enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What happens to the newly formed HIV RNA after being produced?

A

They begin to assemble into new viruses at the cell wall and becomes enclosed in a capsid. It then takes lipids from the cell wall to make surface glycoproteins and buds from the cell wall.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does HIV enter the body?

A

By infecting CD4 cells in the mucous membranes of the vagina or rectum, or by direct infection of CD4 T-cells in the bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is PrEP?

A

Pre-exposure prophylaxis that people at risk of HIV can take consistently to prevent it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How soon after exposure does HIV arrive at the lymph nodes?

A

24 to 28 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where does HIV begin to replicate and how long does this stage last?

A

the lymph nodes for 7-21 days. Not detectable at this period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How soon after exposure is HIV detectable in the blood by viral load testing?

A

Several weeks after infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the common symptoms of acute HIV infection and how long do they last?

A
Symptoms can last for up to 2 weeks:
Fever
Rash
Swollen glands
Myalgia
Significant weight loss
May be asymptomatic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the asymptomatic phase of HIV and how long does it last?

A

After acute infection, HIV will not cause further illness for some years and the number of infected CD4 cells falls. (usually lasts around 10 years)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What does the length of the asymptomatic phase depend on?
How quickly the CD4 count declines--> Once it is below 200 the patient is at far greater risk of AIDS.
26
What are the two largest groups of people living with HIV
Sub-Saharan Africans and homosexuals.
27
Who is most at risk of AIDS
``` Homosexuals Those who have unprotected sex IV drug users Sex workers Truck drivers and migrant workers Uncircumcised men ```
28
How is HIV transmitted?
Unprotected anal, vaginal or oral sex Mother to child in pregnancy, birth or breastfeeding (vertical transmission) Mucous membrane, blood or open wound exposure to infected blood or bodily fluids (e.g. sharing needles)
29
What is Late-Stage HIV?
When AIDs occurs, patients are highly susceptible to opportunistic infections due to low CD4 count
30
What are the most common AIDS-defining illnesses?
Infections--> Pneumonia, Ctyomegalovirus infection Candidiasis, Tuberculosis, herpes simplex e.t.c. Neoplams--> Kaposi's sarcoma, Lymphomas
31
Who should be screened for HIV?
Anybody admitted to hospital with an infectious disease regardless of risk factors and patients with any risk factors.
32
How is HIV tested for?
Antibody blood test p24 antigen test PCR testing with HIV RNA levels indicates viral load
33
How can HIV be monitored?
CD4 count | Viral load
34
What are the symptoms of early symptomatic HIV? (AIDS-related complex ARC)
``` Fever Night sweat Diarrhoea Weight loss Minor opportunistic infection (oral candida, herpes zoster- shingles, herpes simplex) ```
35
How is HIV treated?
HAART: Use more than 3 drugs--> 2NRTIs + 1 NNRTI or 2 NRTI and 1 PI. ``` ART (Antiretroviral therapy)--> Offered to everyone diagnosed despite viral load or CD4 count. Single combination tablet once a day. 2 NRTIs (Nucleoside reverse transcriptase inhibitors) ```
36
What is HAART and what are the different medication classes?
Highly active Anti-retrovirus therapy: Protease inhibitors (PIs) Integrase inhibitors (IIs) Nucleoside reverse transcriptase inhibitors (NRTIs) non-nucleoside reverse transcriptase inhibitors (NNRTIs) Entry inhibitors. (EIs)
37
What additional management is given to HIV patients to reduce risk of complications?
Prophylactiv Septrin given to patients with CD4< 200 to protect against pneumonia Close monitoring of CV risk factors and appropriate treatment (e.g. statins) Yearly cervical smears Vaccinations up to date (avoid live vaccines)
38
What measures should be taken for a HIV positive pregnancy?
Can use sperm washing and IVF C-section should be used unless mother has undetectable viral load Newborns should receive ART for 4 weeks after birth.
39
What is post-exposure prophylaxis?
Combination of ART therapy (Truvada and Raltegravir) given within 72 hours of exposure to prevent infection.
40
What is amyloidosis?
A rare group of conditions caused by an abnormal buildup or a protein called amyloid in the organs, interfering with their normal function.
41
What are the symptoms of AL amyloidosis?
Depends on the tissues/ organs affects: Kidney failure--> Oedema, tiredness, weakness, loss of appetite Heart failure--> S.O.B., oedema, arrhythmia Lightheadedness GI problems Carpal tunnel Easy bruising
42
What causes AL amyloidosis?
Abnormal plasma cells produce abnormal forms of light chain proteins which clump together (amyloid fibrils) and build up in tissues and organs as amyloid deposits
43
How is amyloidosis treated?
No cure but treatments can prevent more abnormal proteins being produced: Chemotherapy (damages abnormal bone marrow cells to stop them producing abnormal proteins) Steroids (boost chemo) Stem cell transplant Treatment of complications (e.g. dialysis, kidney tranplant)
44
How can amyloidosis be diagnosed?
``` Biopsy from affected part of the body See how it has affected the body: -Bone marrow sample -Echocardiogram - Blood tests -CT/ MRI ```
45
What is the most common cancer in women?
Breast cancer
46
Where do the majority of breast cancers arise from?
Epithelial lining of ducts (ductal) or epithelium of terminal ducts of the lobules (lobular)
47
How many women are diagnosed with breast cancer in their life?
1 in 8
48
What are the main breast cancer symptoms?
``` Lump or area of thickened breast tissue Change in size/ shape of breast Discharge from either nipple Lump/ Swelling in either armpit Dimpling of skin Rash Change in nipple appearance (e.g. sunken) ```
49
What are the main risk factors with breast cancer?
``` Age Family history BRXA1 or BRCA2 mutation Previous diagnosis Previous benign breast lump Being tall, overweight or obese Drinking alcohol ```
50
How is breast cancer diagnosed?
``` Breast examination Mammography Ultrasound scan Biopsy Fine-needle aspiration ```
51
What are the two main types of breast cancer?
Non-invasive--> Found in ducts but not spread to surrounding tissue Invasive--> Cancer cells have spread to surrounding breast tissue
52
What is the breast cancer screening programme?
All women age 50-70 invited for mammogram every 3 years.
53
How is breast cancer treated?
Surgery Chemotherapy Radiotherapy
54
What gene is associated with breast cancers?
BRCA1/2
55
What is the most common type of breast cancer?
Infiltrating ductal carcinoma
56
What are the different stages of breast cancer?
Stage 0= ductal carcinoma in situ Stage 1= Tumuor < 2cm and isolated to breast Stage 2= Tumour measures 2-5cm, armpit lymph nodes affected but nowhere else Stage 3= Tumour is 2-5cm and may be attached to structures in the breast such as skin and surrounding tissues, lymph nodes are affected Stage 4= Tumour of anzy size has metastasised.
57
What is the TNM staging system?
``` T= size of tumour N= Whether the cancer has spread to the lymph nodes M= Where the cancer has spread to other parts of the body. ```
58
What are the different grades of breast cancer?
``` Low grade (G1)= Abnormal cells appear to be growing slowly Medium grade (G2)= Cells look more abnormal than G1 High grade (G3)= Cells look more abnormal and grow more quickly. ```
59
What is lymphoedema?
A chronic condition that causes swelling of the tissues due to lymphatic insufficiency.
60
What causes lymphoedema?
When the lymphatic system fails to drain.
61
What are the 2 main types of lympheodema?
Primary lymphoedema- caused by fenetic mutations that affect the development of the lymphatic system Secondary lymphoedema- caused by damage to the lymphatic systemor problems with the movement and drainage of fluid (e.g. cancer treatment, infection, inflammation e.t.c.)
62
What are the symptoms of lymphoedema?
``` Swelling in a limb (may come and go but eventually gets more persistent) Aching, heavy feeling Difficulty moving Skin infections Hard, tight skin, Skin folds ```
63
How is lymphoedema managed?
``` No cure- just treat symptoms: Compression garments Skin care Regular movement/ exercise Healthy diet/ lifestyle ```
64
What is the most common complication of lymphoedema?
Cellulitis- bacterial infection of dermis
65
What causes carbon monoxide poisining?
Inhalation of smoke, car exhaust fumes or improperly maintained/ ventilated heating systems
66
Why does carbon monoxide reduce the oxygen-carrying capacity of Hb?
It has 200 X greater affinity for the oxygen-binding sites on haemoglobin than oxygen.
67
In what direction does CO shift the oxygen-haemoglobin dissociation curve?
Left
68
What are the main symptoms of CO poisoning?
``` Hypoxaemia Vomiting Tachypnoea Headache, mental impairment Convulsions/ coma/ cardiac arrest et.c. ```
69
How is CO poisoning diagnosed?
ABG that looks for oxygen haemoglobin satruration, haemoglobin and COHb/
70
How is Co poisoning treated?
Remove CO source | Give 100% O2 until COHb <10%
71
How can opioid withdrawal symptoms be reduced?
Using methadone (pharmaceutical preperation of an opioid)
72
What are the main presentations of an insecticide overdose? /
``` SLUD: Salivation Lacrimation (tears) Urination Diarrhoea ```
73
What are sarcomas?
Rare tumours that form in the connective tissues.
74
Where can sarcomas develop?
Muscle, bone, nerves, cartilage, tendons, blood vessels, fatty and fibrous tissues
75
What are the two main types of sarcoma?
``` Soft tissue sarcoma (80%) Bone sarcoma (20%) ```
76
What are the red flags that indicate a soft tissue sarcoma?
``` Lump that is : - Big (>5cm) or getting bigger -Deep in body tissues Painful Occurs in older patient ```
77
What are the key presentations of STS?
Lump that is painless at first | Pain and soreness as lump grows and presses against nerves and muscles
78
How is STS diagnosed?
MRI and cor needle biopsy | CT for metastases
79
How is STS treated?
Surgical resection + Chemo/ radiotherapy
80
What are the red flags for.a bone sarcoma?
Non-mechanical bone pain Night pain Palpable bony ass For > 3months
81
How does bone tumour present?
``` Non mechanical bone pain that is still present when lying still Swelling Fatigue Pyrexia Weight loss ```
82
How is bone sarcoma diagnosed?
X-ray CT/ MRI Bone scans/ biopsy
83
How are bone sarcomas treated?
Wide surgical resection/ reconstruction | Chemo/ Radiotherapy