Investigation of Human Disease Essay Example | Topics and Well Written Essays - 1500 words

Investigation of Human Disease - Essay Example Without vitamin K, the levels of these clotting factors will be significantly decreased leading to bleeding tendencies. Liver diseases such as cirrhosis, hepatitis, and atrophy all lead to failure of liver to secrete bile which is necessary for fat metabolism and its absorption together with vitamin K therefore, decreasing absorption of vitamin K as well. Laboratory results are prolonged bleeding time, PT and prolonged to normal PTT, normal platelet count, decreased levels of coagulation factors except VIII, decreased thrombin time and fibrinogen levels (Guyton & Hall, 2008). Warfarin (Coumadin), an oral anticoagulant functions by antagonizing vitamin K through the enzyme epoxide reductase which blocks vitamin K to be reduced in its active form. Thus the Vitamin K-dependent clotting factors as well as the anticoagulant proteins C and S which are produced in the liver are rendered inactive. About 97% of warfarin is tightly bound to plasma protein primarily albumin. Toxicity of the dru g is dose dependent in which single intake of 10-20 mg only leads to mild intoxication. Meanwhile, chronic intake of small quantities of even 2-5 mg daily can result to considerable anticoagulation effects particularly with ingestion of interacting drugs. Likewise, superwarfarins are long acting and are utilized primarily as rodenticides can be highly potent resulting to extended adverse effects with dose as little as 1 mg. Laboratory findings are prolonged bleeding time and PT and decreased coagulation factors II, VII, IX, and X. The main consequence of warfarin or superwarfarin poisoning is bleeding (Olson, n.d.). VKOR (Vitamin K epoxide reductuse) can indicate dosages of warfarin and is encoded by the gene VKORC1. Vitamin K is fat-soluble and is needed as cofactor for the carboxylation of ?-carbon of the glutamic acid residues of the vitamin K-dependent clotting factors namely II, VII, IX, and X. The process is a vital stage for calcium and phospholipid to bind with these protein s. Epoxide reductase and ?-glutamylcarboxylase are important enzymes for metabolism and renewal of vitamin K. Genetic mutations involving these enzymes lead to their defective functioning eventually decreasing also the function of the vitamin-K dependent clotting factors. Laboratory findings are prolonged PT aPTT, and bleeding time, and decreased factors II, VII, IX, and X. Clinical manifestations of the disorder are characterized by hemorrhages ranging from mild to severe that may be apparent at birth. Medical interventions include replacement therapy with fresh frozen plasma or PCCs (Fauci, A., et al., 2008). Patient 2: Laboratory results: Marginal low thrombin time Diagnosis: Factor V Leiden Factor V Leiden mutation is present in about up to 15% of Caucasians. Genetic mutation of glutamine to arginine substitution at 506 position results to a factor V that is resistant to cleavage by protein C. Consequently, a significant antithrombotic counter-regulatory mechanism is lost result ing to a hypercoagulable state which may predispose a patient to develop thrombus formation (Kumar, et al., 2010). APC acts to inactivate factors Va and VIIIa via activation of thrombomodulin by thrombin. Protein C attaches with thrombomodulin producing then APC. Activated protein C also attaches with protein S on surface membranes of platelets. With this, APC can now lyse activated factors V and VIII. But with factor V Leiden, factor V