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Sunday, May 30, 2010

Bacteria Gram-staining.

What is Gram staining?
A type of differential staining, commonly used to differentiate bacterial species into two large groups (Gram-positive and Gram-negative) based on the physical properties of their cell walls.

Gram-positive bacteria have a thick mesh-like cell wall made of peptidoglycan (50-90% of cell wall), which stains purple while Gram-negative bacteria have a thinner layer (10% of cell wall), which stains pink.

Aerobic bacteria.

Gram-positive cocci
- Staphylococci
- Streptococci
- Pneumococci

Gram-positive bacilli
- Corynebacterium
- Bacillus
- Clostridium
- Actinomycetes (filamentous)
- Mycobacterium (stains poorly)

Gram-positive coccobacilli
- Listeria
- Erysipelothrix

Gram-negative cocci
- Neisseria
- Moraxella

Gram-negative bacilli
- all aerobic bacteria which have not been mentioned.

Gram-negative coccobacilli
- Bordetella
- Brucella

Anaerobic Bacteria.

Gram-positive cocci
- Peptococcus
- Peptostreptococcus

Gram-positive bacilli
- Eubacterium
- Lactobacillus
- Bifidobacterium
- Propionibacterium
- Actinomyces
- Mobiluncus

Gram-negative cocci
- Veillonella

Gram-negative bacilli
- Bacteroides
- Prevotella
- Porphyromonas
- Fusobacterium
- Leptotrichia


tips : there are about 30 bacteria species which are Gram-negative bacilli. so in viva voce, if you unsure about the Gram staining of an aerobic bacilli, just say Gram-negative bacilli! insyaAllah, it worth a guess :)

Diuretic Drugs.


What is diuretics?
Diuretics are drugs that promote the excretion of Sodium (Na+) and water in urine.

It is commonly used in patients with;
a) Hypertension (by reducing blood volume)
b) Edema (by concentrating the blood, thus increases plasma oncotic pressure)

They can be classified by their efficacy;
a) High efficacy (Inhibitors of Na+ K+ 2Cl- co-transport)
-Sulphamoyl derivatives: Furosemide, Bumetanide, Torasemide
b) Medium efficacy (Inhibitors of Na+ Cl- symport)
- Benzothiazidines : Hydrochlorothiazide, Benzthiazide, Hydroflumethiazide, Clopamide
- Thiazide-like : Chlorthalidone, Metolazone, Xipamide, Indapamide
c) Weak or adjunctive diuretics
- Carbonic anhydrase inhibitor : Acetazolamide
- Potassium sparing
~Aldosterone antagonist : Spironolactone
~Inhibitors of renal epithelial Na+ channels : Amiloride, Triamterene
- Osmotic diuretics : Mannitol, Isosorbide, Glycerol

Uses of high ceiling diuretics;
1) Edema
- most preferred drug in congestive cardiac failure
2) Acute pulmonary edema
- Furosemide i.v. gives prompt relief
3) Cerebral edema
- Furosemide with osmotic diuretics have high efficacy
4) Hypertension
- given with the presents of renal insufficiency and congestive cardiac failure
5) Blood transfusion
- to prevent vascular overload
6) Hypercalcemia
- Furosemide promotes calcium excretion through the kidney

Uses of thiazides;
1) Edema
- good in maintenance therapy
2) Hypertension
- preferably better than Furosemide
3) Diabetes insipidus
- Reduces urine volume (unlike Furosemide)
4) Hypercalciuria
- Reduces calcium excretion (unlike Furosemide)

Adverse effects
1) Hypokalemia : excess potassium loss via urine
2) Acute saline depletion : Overdosage (esp. Furosemide) may cause dehydration and fall in blood pressure
3) Dilutional hyponatremia
4) GIT and CNS disturbances : Nausea, vomiting, diarrhoea
5) Hearing loss : rarely, but increases risk in renal insufficiency

Tuesday, May 18, 2010

Introduction.

This blog is mainly serves as a purpose of entering my medical notes.

This blog was inspired by my respected friend, Bro Na'im USM.

It may contain some errors. Do inform me by commenting on the particular post. Any corrections will be done immediately.

May this blog be beneficial to myself and all my readers, InsyaAllah.

Thank you.

Imanul Hassan bin Abdul Shukor
4th Semester MBBS
JJM Medical College, Davangere.