Microbiology Genetics

Strep throat.

Antibodies (Human)

The ‘foot’ (bottom) of the antibody is known as the Fc fragment - binds to cells, binds to complement = effector function (kills or removes antigen)

The top (antigen binding) is the Fab fragment

Chains are held together with disulphide binds

Associated molecules allow intracellular signalling 

Normally 3X constant heavy chain domains per chain and a hinge region (except μ and ε which have 4 and no hinge region)

Classes of Immunoglobulins

The five primary classes of immunoglobulins are IgG, IgM, IgA, IgD and IgE,  distinguished by the type of heavy chain found in the molecule. 

IgG - gamma-chains

IgMs - mu-chains

IgAs - alpha-chains

IgEs - epsilon-chains

IgDs - delta-chains.

Differences in heavy chain polypeptides allow different types of immune responses. The differences are found primarily in the Fc fragment. There are only two main types of light chains: kappa (κ) and lambda (λ), and any antibody can have any combination of these 2 (variation).

IgG 

monomer

Gamma chains

70-85% of Ig in human serum. 

secondary immune response 

only class that can cross the placenta - protection of the newborn during first 6 months of life

principle antibody used in immunological research and clinical diagnostics

21 day half life

Hinge region (allows it to make Y and T shapes - increasing chance of being able to bind to more than one site)

Fc strongly binds to Fcγ receptor on phagocyte - opsono-phagocytosis

Activates complement pathway

IgM

Serum = pentamer 

Primary immune responses - first Ig to be synthesised

complement fixing 

10% of serum Ig 

also expressed on the plasma membrane of B lymphocytes as a monomer - B cell antigen receptor

H chains each contain an additional hydrophobic domain for anchoring in the membrane

Monomers are bound together by disulfide bonds and a joining (J) chain.

Each of the five monomers = two light chains (either kappa or lambda) and two mu heavy chains.

heavy chain = one variable and four constant regions (no hinge region)

can cause cell agglutination as a result of recognition of epitopes on invading microorganisms. This antibody-antigen immune complex is then destroyed by complement fixation or receptor mediated endocytosis by macrophages.

In humans there are four subclasses of IgG: IgG1, IgG2, IgG3 and IgG4. IgG1 and IgG3 activate complement.

IgD 

B cell receptor

<1% of blood serum Ig

has tail pieces that anchor it across B cell membrane

forms an antigen specific receptor on mature B cells - consequently has no known effector function (don’t kill antigens, purely a receptor) (IgM as a monomer can also do this)

IgE 

Extra rigid central domain

has the most carbohydrates

IgE primarily defends against parasitic invasion and is responsible for allergic reactions.

basophils and tissue mast cells express very high affinity Fc receptors for IgE - mast cells then release histamine

so high that almost all IgE is bound

sensitizes (activates) mucosal cells and tissues 

protects against helminth parasites

IgE’s main purpose is to protect against parasites but due to improved sanitation these are no longer a prevalent issue across most of the world. Consequently it is thought that they become over activated and over sensitive while looking for parasites and start reacting to eg pollen and causing allergies.

IgA

Exists in serum in both monomeric (IgA1) and dimeric (IgA2) forms (dimeric when 2 Fcs bind via secretory complex)

15% of the total serum Ig.

4-7 day half life

Secretory IgA2 (dimer) = primary defense against some local infections

Secreted as a dimer in mucous (e.g., saliva, tears)

prevents passage of foreign substances into the circulatory system

Isotype: class of antibody (IgD, IgM etc)

Allotype: person specific alleles 

Idiotype: (hyper) variable region - antibody specificity 

Hey, I’m back with another masterpost. I decided to include some of my tips.

Use the forest app to keep you off your phone, your phone is a distractions you face when studying

Try making a to-do list to plan out how much time you take to do each task so you keep track of time

Set rewards i.e. if I finish this task at 9am instead of 9.30am, I’ll watch my favourite tv show for 1 hour instead of 30mins.

How to be disciplined

I guess this is pretty much like a habit. So try to maybe start small, i.e. study 10 mins each day and gradually increase the time limit if you feel comfortable doing so. The reason I chose 10 mins is because it seems like a very short period of time so it’s easier for you to get to work.

How to manage studies with social media

Always set a time period for your school work. For example, after 30 minutes of browsing through your social media, force yourself to do a piece of school work. That way, you will still get work done instead of browsing through your social media all day long.

If you realise on tumblr, I don’t come up with an original post every day and I tend to reblog my old post or queue others posts so don’t stress too much on coming up with a post. For instagram, you could try to take pictures all during the weekend, so you don’t have to stress taking them after school, etc.  But it is important to always put studies first before your social media.

Consider switching off your phone or even deleting your social media apps or deactivating them during exams period if they are really getting in the way of your studies.

Plan

How to schedule your day when you’re unemployed by @businessinsider

How to stick your plans by @cafeinated

How to make and stick to your study plan by @sherlocks-study

Create long term study plan + how to stick to study routines by @studyforyourself

Start

How to start studying by @studylou

How to start working when you really don’t feel like it? by @studentstoolbox

What to do when you really don’t want to study by @yeon-studies

How to stop scrolling through tumblr for 3 hours when you have work by @effectivestudies

More productive

How to become more productive by @to-work-or-not-to-work

How I increased my productivity by 3 times by @brbimstudying

4 secrets to efficiency

The ivy lee method for peak productivity by @harcules

General

How to study as a busy student by @julstudies

Use studyblr to become productive by @determinationandcaffeine

Take a productive break by @thestudycoffee

5 things everyone should do on sunday night by @staedtlers-and-stabilos

Productivity 101 by @lets-study-together

The no bullshit guide to getting your shit together: for the lazy student by @knoweldge

Habits

8 morning habits for productivity by @eintsein

The 8 habits of highly productive people by @medicinasanguis

Habits of highly effective people by @onlinecounsellingcollege

6 habits for maximum productivity by @livingthatlibrarylifestyle

How to develop self discipline

How to wake up earlier by @gurl

Motivation

Focus and motivation by @katsdesk

Whenever you’re feeling unmotivated and sleepy by @evergreenstudies

How to stay awake while studying without caffeine by @getshitsdone

How to be productive + motivated on weekends by @studywithinspo

Procrastination

Types of procrastination and how to deal with them by @emmastudies

How to stop procrastination

How to stop procrastinating by @cutestudystuff

15 productivity hacks for procrastinators by @engincrd

Unconventional methods to beat procrastination by @hawkestudies

What type of procrastinator are you by @b-uwu-ng

Eliminating procrastination and distraction during a study session by @simply-study

Productive when travelling

productive commutes by @universi-tea

productivity on road trips by @intellectys

Tips

7 productivity tips by @simmonestudies

10 small tips to improve your productivity

The dutch student’s productivity tips by @thedutchstudent

My top 10 tips for productivity by @lovelybluepanda

21 tips to become the most productive person you know by @studying-towards-success

Tips and tricks for busy students by @roeum

Time management

Managing time

How to manage time by @solar-citrus

How i manage my time by @pensandmachines

Time management 

Tips

Time management tips by @365text

Time management tips for busy students

Time management tips

Tips for time management by @holocrams

26 time management hacks I’d wish I’d known at 20 by @geekvitamin

How to make the best use of your time by @tbhstudying

5 ways to manage your time efficiently by @quadrtics

Printables

Daily planner by @arystudies

Weekly planner by @studyblrbunny

Productivity printables by @thearialligraphyproject

Habit tracker by @candydsgn

Schedules by @kouiro

Bullet journal

My 2016 bullet journal setup

Sounds

Study sounds by @studyquill

Other masterposts by me

Printables

College

Apps for students

Note taking

Math

Bullet journal

icon credit to @nerdastically

Micobacterium tuberculosis DX

Auramine-Rhodamine staining bacilli: fluorescent apple green (sensitive but not specific). If positive, do acid fast.

Acid Fast

Lowenstein-Jensen medium: aerobic, slow growing (2-3weeks)

PPD or Mantoux Test: measure 48-72h after. POSITIVE: >/= 5mm in VIH+ pts, >/=10mm in high risk population (IVDA, poverty, immigrants from high TB area, physicians, nurses), >/=15mm in low risk population

Positive indicates exposure, but not necessarily active disease.

Quantiferon-TB Gold Test: measures IF-gamma

Niacin producers

Catalase negative at 68° and catalase active at body T°

No serodiagnosis

To all my microbiology studiers out there. I found this video when I was studying for the virology block of my micro class, and this + sketchy micro was an absolute GODSEND. If you’re struggling with remembering the structures and families of the viruses or prefer flow charts over big tables, CHECK THIS DUDE OUT. I could listen to him talk viruses to me all day. 

Here’s a look at how I implemented it into my First Aid (pages 148, 150).

Hope someone finds this helpful!

Passive Immunotherapy

Active immunotherapies:

Cytokines (TNFa IL-2, IFNs)

Cancer vaccines

tumour CTL and APC

DC priming

Passive immunotherapy:

Administration of monocolnal (clone derived asexually from a single individual or cell) antibodies which target either tumour-specific or over expressed antigens

Generally comprised of antibodies made outside of the body (in a lab)

administered to patients to provide immunity against a disease, or to help fight existing disease

do not stimulate a patient’s body to ‘actively’ respond to a disease the way a vaccine does

immunogen is given several times to induce a strong secondary response

blood serum contains many different antibodies to the immunogen

most immunogens have multiple antigenic epitopes 

each stimulates a different B cell clone/receptor –> polyclonal antibody (PAb) response 

Monoclonal antibody (mAb) therapy is the most widely used form of cancer immunotherapy. Monoclonal antibodies cannot be purified from a polyclonal sample and are derived from a single clone/specific for a single epitope.

Antibodies in cancer therapy:

Trigger immune system to attack cancer cells 

Block molecules that stop the immune system working (checkpoint inhibitors)

 Block signals telling cancer cells to divide 

Carry drugs or radiation to cancer cells

Checkpoint inhibitors

Immune system uses particular molecules to stop it being over activated and damaging healthy cells  - these are known as checkpoints

some cancers make high levels of checkpoint molecules to switch of immune system T cells which would normally attack cancer cells

examples of targets include CTLA-4, PD-1 and PD-L1 (programmed death ligand 1)

Blocking cell division signals 

Cancer cells often express large amounts of growth factor receptors on their surface –> rapid cell division when growth factors stimulate them

some monoclonal antibodies stop growth factor receptors working

either by blocking the signal or the receptor itself 

cancer no longer gets signal to divide

Carrying drugs/radiation

drugs or radioisotopes can be attached to monoclonal antibodies

the mAB binds to the cancer cell, delivering directly

known as conjugated MABs

Tularemia as a biological weapon

It was viewed as an attractive agent because:

it is easy to aerosolize,

it is highly infective; 10-50 bacteria are required to infect,

it is nonpersistent and easy to decontaminate (unlike anthrax),

it is highly incapacitating to infected persons,

it has comparatively low lethality, which is useful where enemy soldiers are in proximity to noncombatants, e.g. civilians

can you see the irony……we are working our ass off to kill these bugs.At th same time some weirdo working in one lab is making bio weapon.

Medically Important Bacteria: Clasification