CLINICAL NOTES

  BONE MARROW EXAMINATION It is the only method of correctly diagnosing diseases of blood. Sites of bone marrow aspiration: The following sites are selected for bone marrow aspiration: Sternum Iliac crest and upper end of tibia in children. Requirements: A special bone marrow needle (salah or klima needle) along with stilette Local anesthesia (Lignocaine) 2 to 5 ml syringe Glass slides Absolute methanol Formal ethanol Procedure: The site of puncture is usually sternum. Sterilize the selected site with soap water, iodine and finally with alcohol. The Site is anesthetized locally using lignocaine. Skin and subcutaneous tissues are punctured using sterilized bone biopsy and needly. When needle reaches periosteum, guarded needle is pushed further about 5 mm. Now the needle is fixed tightly in position. Now the needle is further pushed with boring motion into the cavity of bone. The stilette is removed and well fitted 2-5 ml syringe is used About 0.3 ml of bone marrow contents are sucked. P

Introduction: For the investigation of a case of bleeding disorder,clinical history is very important. An accurate clinical and family history will often give an important time-saving clue to the nature of underlying bleeding disorder. 􀂄 Appearance of purpuric spots or bruises over minimally injured surface suggests an abnormality of the vascular wall. 􀂄 Continuous bleeding from mucous membranes, cuts, wounds, deeper haematomas or bleeding into the joints will suggest a defect in the blood coagulation system. 􀂄 Excessive bleeding following delivery, or retention of dead foetus, or oozing following extensive surgery, suggest the possibility of fibrinogen depletion or presence of circulating anticoagulant agents. 􀂄 History should also be taken about the ingestion of antiplatelet drugs such as aspirin. Two of the commonly used screening tests, bleeding time and whole blood clotting time, are discussed below. BLEEDING TIME  (BT) Bleeding time is duration of bleeding from a standard pun

ROUTINE STAINING (H & E) Routine staining is done with haematoxylin and eosin (H&E). Haematoxylin This is a natural dye which is obtained from log-wood tree, Haematoxylon campechianum.  This tree is nowadays commercially grown in Jamaica and Mexico.  The natural extract from the stem of this tree is haematoxylin which is an inactive product.  This product is oxidised to an active ingredient which is haematein.  This process of oxidation is known as ripening which can be done naturally in sunlight, or chemically by addition of oxidant like sodium iodate, KMnO4 or mercuric oxide. A mordant is added to it (e.g. potash alum) which helps in attaching the stain particles to the tissue. Procedure for Staining: Sections are first deparaffinised (removal of wax) by placing the slide in a jar of xylene for 10-15 minutes.  As haematoxylin is a water-based dye, the sections before staining are rehydrated which is done by passing the sections in a series of descending grades of alcohol and

ERYTHROCYTE SEDIMENTATION RATE (ESR) ESR is used as an index for presence of an active disease which could be due to many causes. Principle When well mixed anticoagulated blood is placed in a vertical tube, the erythrocytes tend to fall towards the bottom of the tube/pipette till they form a packed column in the lower part of the tube in a given time. Mechanism of ESR Fall of RBCs depends upon following factors: i. Rouleaux formation ii. Concentration of fibrinogen in plasma iii. Concentration of α and β globulins iv. Length of the tube v. Ratio of red cells to plasma vi. Bore of the tube vii. Position of the tube i) Rouleaux formation The erythrocytes sediment in the tube/pipette because their density is greater than that of plasma. When a number of erythrocytes aggregate in the form of rouleaux and settle down, their area is much less than that of the sum of the area of constituent corpuscles. The rouleaux formation is very important factor which increases the ESR. ii) Concentration

Introduction to Vitamin: Vitamin may be defined as organic compounds occurring in small quantities in different natural foods and necessary for growth and maintenance of good health in human beings and in experimental animals. Vitamins are essential food factors, which are required for the proper utilization of the proximate principles of food like carbohydrates, lipids and proteins. All the vitamins are usually available in an ordinary Indian diet. The vitamins are mainly classified in to two: 1. The fat soluble vitamins are A,D,E and K 2. Water soluble vitamins are B complex and C . Vitamin A: It is a fat soluble . The active form is present only in animal tissues. The pro-vitamin, beta - carotene is present in plant tissues. One molecule of beta-carotene can theoretically give rise to two molecules of vitamin A. Vitamin A has a beta- ionone (cyclohexenyl) ring system. Three different compounds with vitamin A activity are retinol (vit.A alcohol), retinal (vit A aldehyde) and retinoic

Tissue Processing:       Nowadays all the process of fixation, dehydration, clearing, and impregnation are carried out in a special equipment which is known as automated tissue processor. It can be a open (hydraulic) system or a closed (Vacuum) type. In the open type, the tissue processor has 12 - 16 glass jars for formalin, ascending grades of alcohol, xylene and thermostatically- controlled two paraffin wax baths to keep paraffin wax in molten state. Tissue moves automatically by hydraulic mechanism from one jar to another after fixed time schedule and the whole process takes 16-22 hours. In closed type of tissue processor, tissue cassettes are placed in a single container while different processing fluids are moved in and out sequentially according to electronically programmed cycle. The closed or vacuum  processor has the advantage that there is no hazard of contamination of the laboratory by toxic fumes unlike in open system. In addition, heat and vacuum can be appli