I’m presenting here content already posted before, but it has gotten much attention and acclaim from my visitors, so I thought I’d re-publish it. It has also been used in Wikipedia in three articles.

It’s an illustration I’ve made a long time ago on the renal physiology and corresponding diuretics. My visitors liked it so much. One of them, va, used it for his MRCS exam, and another one, khairul Majumder, showed the illustration to the nurses, explaining to them the basics of the renal physiology.

Head over to the original post to view a full-sized version of the illustration, read the detailed description, and be able to comment.

SITE
• Largely localized to left ventricle

TYPES (ACC. TO DEPTH)
• Transmural (“Prolonged-” Q wave MI)
• Subendocardial (Non-Q wave MI or Non-ST Elevation MI; NSTEMI)

TYPES (ACC. TO SITE)
Type: Corresponding EKG changes in
• Inferior: Leads II, III, aVF
• Anterior: Leads V1-V4
• Lateral: Leads I, aVL, V4-V6
• Posterior: Leads V1, V2 (Tall T, ST depression)

DEFINITE DIAGNOSIS
By EKG
• ST segment changes, or
• New LBBB (left bundle branch block)

EKG PATTERNS
• Transmural MI (Q wave MI):
Hyperacute T & ST elevation » T-wave inversion » prolonged Q
• Non-Q-Wave MI (Also termed non-ST elevation MI, or NSTEMI):
ST depression » persistent ST-T-wave changes without Q-wave development

Quick intro:
Hypersensitivity reactions occur due to the introduction of a certain antigen (Ag) which the body finds foreign and thus tries to eliminate it with the help of certain cells and antibodies (Ab). This conflict produces an immune process, a war-like phenomenon known as hypersensitivity reaction.

Remember the mnemonic: [ ACID ]:

Type I; Anaphylactic/Atopic
- Mast cell or basophil + Ag + IgE
- e.g. Anaphylaxis (e.g. to penicillin), Asthma

Type II; Cytotoxic (kills cells)
- Affected cell + Ag + IgM/IgG
- e.g. Autoimmune hemolytic anemia, Rh factor dse, Rheumatic fever

Type III; Immune complex
- Ag + Ab + complement (e.g. C3, C5)
- e.g. Post-streptococcal glomerulonephritis, SLE, Rheumatoid arthritis

Type IV; Delayed (T-cell mediated)
- T lymphocytes + Ag » formation of lymphokines
- e.g. TB skin test, Transplant rejection, Contact dermatitis

Some information, including the mnemonic, was taken from First Aid for USMLE Step 1 book.

Most common
• Bronchogenic Carcinoma (++)
• Pulmonary Infarction (++)
• T.B. (+)

Common
• Bronchiectasis
• Lung abscess (+ pus)
• Bronchitis (acute; chronic; COPD)

Uncommon
• Tumors of Trachea, Larync
• Bronchial Adenoma
• Lung secondaries

Others
• Chest trauma
• F.B.
• Iatrogenic

¶ S1
• pronounced in MS
• weak in MR/MP

¶ S2
weak in both AS and AR

¶ S3 (blood splash!)
• comes just after S2 (early diastole)
• lub-dub-‘dub’
• normal in children, young adults, athletes, pregnancy, fever
• abnormal in others
• cause:
large poorly contractile left ventricle usually due to volume overload
“blood from pulmonary veins forcefully hits the inside of the LARGE ventricle making this sound”. This is common in MR and AR.

¶ S4 (atrium contracts!)
• comes just before S1 (late diastole)
• ‘da’-lub-dub
• almost always abnormal
• cause:
left ventricle hypertrophy (not enlargement) due to an obstructive cause
“atrium forcefully contracts to get blood into the highly tense muscular ventricle”. It is common in HTN, AS, MS “late”, restrictive cardiomyopathy.

Recently it striked me the prevalence of use of Cortisone, secondary to prevalence of collagen and autoimmune diseases, and inflammatory or allergic  conditions. Maybe the incidence is the same, but it’s just the advance of diagnosis and investigations, but the end result is the same, Cortisone is highly used nowadays in many, many conditions.

Well, to understand the side effects (especially of prolonged use of Cortisone), a quick reference to the actions of Glucocorticoids is a must:

1. Maintains metabolic homeostasis:

A. Regulates blood glucose level/permissive effects on gluconeogenesis/increases glycogen synthesis

B. Raises Insulin levels/permissive effects on lipolytic hormones

C. Increases catabolism/decreases anabolism (except fat)/inhibits growth hormone axis

D. Inhibits reproductive axis

E. Mineralocorticoid activity of cortisol

2. Affects connective tissues:

A. Causes loss of collagen & connective tissue

3. Affects calcium homeostasis:

A. Stimulates osteoclasts/inhibits osteoblasts

B. Reduces intestinal calcium absorption/stimulates PTH release/increases urinary calcium excretion/decreases reabsorption of phosphate

4. Maintains cardiovascular function:

A. Increases cardiac output

B. Increases vascular tone

C. Permissive effects on pressor hormones/increases sodium retention

5. Affects behavior and cognitive function

6. Affects immune system:

A. Increases intravascular leukocyte concentration

B. Decreases migration of inflammatory cells to sites of injury

C. Decreases antigen-antibody reaction

D. Suppresses immune system (thymolysis, suppression of cytokines, kinins, serotonin, histamine, collagenase, and plasminogen activator)

7. Antistress/Antishock

About side effects of prolonged use:

1. Edema

2. Hypertension

3. Heart failure

4. Cushing’s syndrome

5. Psychosis

6. Osteoporosis

7. Growth retardation in children

8. Delayed healing of wounds

9. Increases intraocular pressure (glaucoma)

10. May precipitate diabetes mellitus

11. Perforation of peptic ulcer

12. Infections: e.g. Activation of tuberculosis, fungal infection

13. Hirsutism, menstrual irregularities

14. Sudden withdrawal —> Acute adrenocortical insuffieciency/Addisonian crisis

Skyscape announces the release of First Aid Q&A For The USMLE Step 2 CK (The McGraw-Hill Companies, Inc.), First Aid Cases For The USMLE Step 2 CK (The McGraw-Hill Companies, Inc.) and First Aid For The USMLE Step 3 (The McGraw-Hill Companies, Inc.) for mobile devices.

First Aid Q&A For The USMLE Step 2 CK
(Tao Le, MD, MHS, Anil Shivaram, MD and Joshua Klein, MD, PhD)

This new study tool for the USMLE Step 2 CK features 1000 board-style questons and answers with explanations for correct and incorrect answers.

First Aid Cases For The USMLE Step 2 CK
(Tao T. Le, MD, MHS, Esteban Schabelman, MD, MBA, Anil Shivaram, MD and Joshua Klein, MD, PhD)

Designed to provides students with the most useful and up-to-date preparation guides for the USMLE Step 2 CK.

First Aid For The USMLE Step 3
(Tao Le, MD, MHS, Vikas Bhushan, MD, Robert W. Grow, MD, MS and Veronique Tache, MD)

First Aid for the USMLE Step 3 is the most useful and up-to-date preparation resource designed for residents and international medical graduates for the USMLE exams.

Those programs should work on: BlackBerry ®, iPhone/iPod Touch, Palm OS ® [3.5 or higher], Symbian S60 [3rd edition] (Nokia), Windows Mobile™ Pocket PC [all versions], Windows Mobile Smartphone, Windows 98/2000/ME/XP/Vista/Tablet PC.

Don’t forget to recheck your device compatibility before purchasing.

Medicopedia is not affiliated with Skyscape in any way.

Reference:
s is related to the surface antigenic component
c is related to the core antigenic component
e is related to the envelope antigenic component

Look for these in the question! They could be the only key to the diagnosis!

• HBsAg » HBV infection
• No Anti-HBc » no HBV infection
• HBeAg » active viral replication
• Anti-HBs » immunity is present
• Anti-HBc » according to type of Ig:
IgM » acute/recent infection
IgG » chronic infection

Here’s also a table listing those in detail, in addition to markers of other hepatitis viruses. (Thanks to our author mixeva for the image. Original source: Cecil Essentials).
Hepatitis Markers

A fellow author has recently joined Medicopedia!

Please let me introduce her to you:

mixeva has just finished her 6th year of Medical School in Egypt, and she will be starting her internship soon.

You can start reading her first post, titled “Interstitial Lung Diseases (ILD)/ including Pneumoconioses” by clicking here.

Hope you enjoy her posts!

Hello everyone

So, while I was having my oral exams this year, I came across a question that many people were asked: “ILD”, so I looked it up to find that it includes a very wide range of diseases that I studied individually, but never had them collected, they’re quite interesting actually, especially the pneumoconiosis causes (that rhymes ), let’s go:

ILD, or Interstitial Lung Diseases, is a term that refers to a group of diseases that affect the “interstitium” of lungs; alveoli, capillaries, the separating basement membrane and the perivascular/lymphatic tissues. Almost everything but the bronchial tree or the (Obstructive Lung Diseases).

They give a diffuse shadowing pattern, or a “miliary pattern” on chest x-ray.

The full classification is after the break.

1. Infections:

Virus

Influenza

Varicella

Smallpox

Measles

Q Fever

CMV

Psittacosis

Mycoplasma

Legionnaires’

Parasite

Pneumocystitis

Schistosoma

Microfilaria

Mycobacteria

Tuberculosis

Atypical

Bacterial

Gram-negative bacilli

Staphylococci

Fungal

Histoplasma

Coccidioides

Blastomyces (South American)

Candida

Cryptococcus

Aspergillus

2. Pneumoconiosis

Silicosis

Coal Miners’

Asbestosis

Beryllium

Talc

Graphite

Aluminium

Silo fillers’

3. Allergic Alveolitis: (Now that’s interesting!)

Farmers’ lung

Bird fancier lung

Maple bark

Air conditioning

Bagassosis

Sequoia tree

Pituitary snuff

Cheese washer

Mushroom worker

Malt worker

Coffee & tea growers

Woodworkers lung

Coptic lung (cloth wrappings of mummies, now that’s where the “curse” comes from )

4. Malignancy:

Alveolar cell carcinoma

Metastases (haematogenous et lymphatic)

Leukaemia

Hodgkin’s

5. Drugs

Methotrexate

Bleomycin

6. Cardiovascular diseases:

Mitral stenosis

Haemosiderosis

Goodpasture’s Syndrome

7. Fibrosing alveolitis:

Rheumatoid Arthritis

SLE

Systemic Sclerosis (Scleroderma)

Neurofibromatosis

Dermatomyositis

8. Autoimmune:

Sjogren’s Syndrome

Fibrosing alveolitis

9. Misc.:

Sarcoidosis

Histocytosis X (eosinophilic granuloma)

Alveolar proteinosis

Thesaurosis

Macroglobulinaemia

Almost everything in the world is in this list, huh? I found many classifications, but this was the only one that had it all, enjoy!