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Showing posts from September, 2011

Effect of alcohol on body temperature

Ingestion of alcohol makes you feel warm because it causes cutaneous vasodilation. Increased blood flow to the skin coupled with a low environmental temperature means that there is a more rapid loss of heat from the body. Furthermore, consumption of a large amount of ethanol leads to depression of the central temperature regulating mechanism. Thus drinking alcohol excessively in cold climates can lead to hypothermia and even death if appropriate measures are not taken.

Atrial fibrillation - classification AHA/ACC/ESC

1) First detected AF - It is the designation given when diagnosis has only recently been made. 2) Recurrent AF - When patient has experienced two or more episodes of AF. 3) Paroxysmal AF - Self terminating episodes that generally last less than 7 days (mostly <24 hr) 4) Persistent AF - Last more than 7 days and requires electrical or pharmacologic cardioversion. 5) Permanent AF - It has failed cardioversion and has been sustained for more than a year.

Diabetes insipidus - effect of desmopressin

This is a continuation of the main article  Diabetes insipidus . It shows the effect of desmopressin in a case of central D.I. The changes seen are: 1) decrease in urine output, 2) increase in urine osmolarity, 3) decrease in plasma osmolarity and 4) slight increase in body weight. Desmopressin is 12 times more potent antidiuretic than ADH. It has a duration of action of around 8 hours and thus can be given in 3 divided doses per day. The intranasal route is preferred though the bioavailability is only 10-20%. Treatment is life long.

Diabetes insipidus

Definition: It is a syndrome characterized by the production of abnormally large volumes of dilute urine due to the decreased secretion or decreased action of AVP (arginine vasopressin). AVP is also commonly known as ADH i.e. Anti Diuretic Hormone. Cause: 1) Central D.I - aka pituitary D.I or neurohypophyseal D.I. 2) Nephrogenic D.I Central D.I occurs because of an inadequate release of ADH from the posterior pituitary. The usual causes are idiopathic, traumatic, iatrogenic (surgery,radiation), neoplastic, infective, granulomatous (TB,sarcoidosis) and congenital being a rarer cause. Nephrogenic D.I is due to the resistance to ADH at the level of the collecting duct cell. The most common cause of resistance is the use of drugs like lithium (bipolar disorders) and amphotericin. But it can rarely be due to a congenital cause. Pathogenesis: The antidiuretic effect of ADH is achieved by increasing the hydroosmotic permeability of cells that line the distal tubule and medullary

Gene cloning - steps and applications

Application: 1) Production of recombinant proteins like factor VIII, insulin and tissue plasminogen activator, 2) Transgenic organisms also called as genetically modified organisms like herbicide resistant crops, 3) Gene therapy to correct a genetic disorder or an acquired disease, though there has only been limited success in this field till now.

Azithromycin - macrolide

Group: macrolide Antimicrobial activity: Good against Gram positive and Gram negative organisms. Slightly less active than erythromycin against staphylococci and streptococci but more active against H.influenzae. It is also highly active against chlamydia, Mycobacterium avium complex and Toxoplasma gondii. Mechanism of action: It binds to the 50s ribosome subunit and hinders the translocation of the elongated peptide chain from the acceptor site to the peptidyl site. Thus the ribosome does not move along the mRNA to expose the next codon and peptide synthesis is prematurely terminated. Pharmacokinetic properties: Acid stability and more active in alkaline medium, rapid oral absorption but better given 1 hour before meals or 2 hours after meals, marked tissue distribution especially intracellular penetration (macrophages and fibroblasts), Half life : 2-4 days, therefore can be given as once a day dosing Clinical uses: 1) Legionnaire's pneumonia - 500 mg O.D for 2 wee

Opiods in acute pulmonary edema

The use of I.V morphine in dyspnea from pulmonary edema due to left ventricular failure produces remarkable relief. The proposed mechanisms include:  1) reduced anxiety ( decreased perception of shortness of breath ),  2) reduced cardiac preload ( reduced venous tone ) and  3) decreased cardiac afterload (decreased peripheral resistance ).  However frusemide remains the treatment of choice.  Side effect is respiratory depression at a higher dosage which occurs because of inhibition of the brainstem respiratory mechanism.

Whipple's triad - hypoglycemia diagnosis and treatment

 DIAGNOSIS  Hypoglycemia can be diagnosed by whipple's triad which consists of: 1) symptoms consistent with hypoglycemia, 2) a low plasma glucose concentration measured by an accurate method, 3) relief of the symptoms when the plasma glucose level is raised.  SYMPTOMS  Symptoms of hypoglycemia are: 1) Neuroglycopenic symptoms like behavioral changes, fatigue, seizures, altered consciousness, 2) Adrenergic symptoms like palpitations, tremors, anxiety, 3) Cholinergic symptoms like sweating, hunger and altered sensations The cut off value for hypoglycemia is 70 mg/dL which is equal to 3.9 mmol/L.  TREATMENT  Relief of symptoms can be done by: 1) an initial 20 g of carbohydrate containing fluid or food can be given if the patient can tolerate orally, 2) I.V glucose 25 g bolus at 2 mg/kg/min followed by 10 g/hr. 250 mL of 10% dextrose is better than 50 mL of 50 % dextrose as there is less thrombophlebitis. 3) Glucagon 1 mg subcutaneously or intramuscularly works as rap


It is caused by an organism known as Bacillus anthracis. The latter is a gram positive, spore-forming rod that is found in soil. The spores can remain viable for years. Anthrax came to public notice in September 2001 when it was used as a bioweapon delivered through the U.S Postal System causing infection in 22 persons of whom 5 died. In the past i.e. during World War II , anthrax was studied mainly for its potential use as a biological weapon but following the Biological and Toxin Weapons Convention Treaty in 1972, such research was no longer allowed. Still, some nations and extremist groups do work on this agent secretly. There are 3 major clinical forms of anthrax: 11)       Gastrointestinal anthrax – from ingestion of contaminated meat 22)       Cutaneous   anthrax – from introduction of spores through opening in skin 33)       Inhalational anthrax- inhalation of spores that deposit in the alveolar spaces. The inhalational form is the one usually used for biot

Newly diagnosed Diabetes Mellitus type 2 - minimum assessment

1)  Measurement of height, weight, waist, BMI 2) Measurement of blood pressure  3) Examination of feet for pulses, loss of sensation to touch/vibration, signs of  infection  4) Measurement of visual acuity  5) Urine tested for albumin, ketones and glucose  6) Record made of current physical activity/recreational exercise levels, smoking  history and alcohol consumption, addition of salt to prepared food  If the resources and laboratory facilities are available then the following may be desirable.  •  ECG as baseline  •  Fasting blood lipids-cholesterol and triglycerides, HDL, LDL  •  Serum urea and creatinine for those with proteinuria  •  Retinal examination by fundoscopy  •  Urine for microalbuminuria if dipstick –ve  •  Glycosylated haemoglobin (HbA1c) 

Axilla / Cubital fossa / Carpal tunnel

The axilla is an irregularly shaped pyramidal area formed by muscles and bones of the shoulder and the lateral surface of the thoracic wall. The apex or inlet opens directly into the lower portion of the neck. The skin of the 'armpit' forms the floor. All major structures that pass between the neck and arm pass through the axilla. The cubital fossa is a triangularly shaped depression formed by muscles anterior to the elbow joint. The brachial artery and the median nerve pass from the arm to the forearm through this fossa. The carpal tunnel is the gateway to the palm of the hand. Its posterior, lateral, and medial walls form an arch, which is made up of small carpal bones in the proximal region of the hand. A thick band of connective tissue, the flexor retinaculum, spans the distance between each side of the arch and forms the anterior wall of the tunnel. The median nerve and all the long flexor tendons passing from the forearm to the digits of the hand pass through t

Differences between hemoptysis and hematemesis

1) There is usually a tingling sensation in the throat in hemoptysis while in hematemesis the patient will usually complain from nausea and upset stomach. 2) The blood is usually frothy and bright red in hemoptysis while it is dark red in hematemesis, non-frothy and food particles may also be present at the same time. 3) Blood in hematemesis will give an acidic pH when tested with litmus paper whereas that in hemoptysis will be neutral to alkaline. 4) Stools will be almost always positive for occult blood in hematemesis while it is usually negative in case of hemoptysis. But it can also be positive at times if the patient has swallowed his sputum. Last reviewed on: 1 September 2015