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Colchicine - complete information

Introduction: Colchicine is an alkaloid isolated from the autumn crocus, Colchicum autumnale. It is actually present in the corm of the plant, the underground swollen part of the stem. Pharmacokinetics: Colchicine is absorbed readily when taken in orally. It reaches peak plasma levels within 2 hours.  It has a serum half-life of 9 hours.  Colchicine is partially deacetylated in the liver and the unchanged drug and its metabolites are excreted in the bile and undergo intestinal reabsorption. Colchicine is found in high concentrations in leucocytes, kidneys, the liver and spleen. Most of the drug is excreted in the feces but 10 to 20% is excreted in the urine and this proportion rises in patients with liver disorders. For patients with creatinine clearance of < 50 mL/min, colchicine must be avoided or used at a lower dose. Colchicine is also distributed into breast milk. Pharmacodynamics: Colchicine relieves the pain and inflammation of gouty arthritis in 12-24 hou

Pulmonary embolism due to metallic mercury

Above is a chest radiograph of a schizophrenic patient. He was delusional about being a doctor. He used to read a lot of medical books and mastered the art of taking blood pressure. During an episode of psychosis, he broke the blood pressure apparatus and injected the mercury into his vein. We can see in the X-ray that there is micro-embolism of the liquid mercury to the pulmonary arterioles, mostly to the dependent areas and the arrow indicates a small pool of the mercury in the right ventricle.

Popliteal artery cyst

This is a popliteal arteriogram of a 27 year old male who presented with pain in left calf when exercising. Signs of deep vein thrombosis were negative but there was minimal swelling at the left ankle. A palpable pulsatile mass could be felt on the popliteal fossa. On arteriography a filling defect was obtained as shown in the picture above. CT scan confirmed that the cyst was within the popliteal artery wall.

Insulin - Structure

Insulin is a protein hormone. It was the first protein to be shown to have a precisely defined amino acid sequence. This work was done by Federick Sanger in 1953.  As shown above in two colours, the insulin molecule consists of 2 peptide chains.  a) The blue coloured chain is the A chain. It has 21 amino acids and a sisulphide bond within itself.  b) The yellow colour represents the B chain. It is larger with 30 amino acids.  Both chains are connected by 2 disulphide bridges.  Porcine and bovine insulins differ from human insulin at 1 and 3 positions of the amino acids respectively. 

Tests performed in diagnostic abdominocentesis

Diabetes Mellitus - Definition / Criteria for diagnosis

Definition: It is a group of metabolic disorders that is characterized by hyperglycemia which is due to a relative or absolute deficiency in insulin. There is usually a defect in insulin secretion, a defect in insulin action or a combination of both.  Criteria for diagnosis: 1) An Fasting Plasma Glucose   ≥  7.0 mmol/L (126 mg/dL),  2) A Plasma Glucose    ≥  11.1 mmol/L (200 mg/dL) 2 h after an oral glucose tolerance test, 3) An HbA1c    ≥    6.5% or 4) A Random Plasma Glucose concentration    ≥   11.1 mmol/L (200 mg/dL) accompanied by classic symptoms of DM (polyuria, polydipsia, polyphagia, weight loss).  Note: 1) Fasting means no calorie intake for the past 8 hours. 2) For the glucose tolerance test, we must use 75 g of anhydrous glucose dissolved in water. 3) The diagnostic HbA1c test should be performed using a method certified by the National Glycohemoglobin Standardization Program (NGSP) and standardized or traceable to the Diabetes Control and Complications Trial (D