Dentosphere : World of Dentistry

 # Which of the following have decreased osmotic fragility?  a. Hereditary spherocytosis  b. Hereditary elliptocytosis  c. Hereditary xerocytosis  d. Hereditary stomatocytosis/hydrocytosis The correct answer is C. Hereditary xerocytosis. Osmotic fragility has been typically increased in Hereditary spherocytosis and hereditary  elliptocytosis. There are 2 types of hereditary stomatocytosis: hereditary xerocytosis (complex permeability defect d/t increased membrane lipids) and hereditary stomatocytosis – hydrocytosis (d/t deficiency of band 7.2b or stomatin). Both have autosomal dominant inheritance. Osmotic fragility is decreased in xerocytosis and increased in hydrocytosis. Xerocytosis may result in recurrent fetal loss, hydrops fetalis, neonatal hepatitis and familial pseudohyperkalemia. CLICK HERE FOR MORE MCQs

 Which of the following is a major risk factor for venous thrombosis? a. Smoking b. High cholesterol c. Hypertension d. Diabetes mellitus e. Cancer The correct answer is E. Cancer. Venous thrombosis, including deep vein thrombosis and pulmonary embolism, occurs at an annual incidence of about 1 per 1000 adults. Rates increase sharply after around age 45 years, and are slightly higher in men than women in older age. Major risk factors for thrombosis, other than age, include exogenous factors such as surgery, hospitalization, immobility, trauma, pregnancy and the puerperium and hormone use, and endogenous factors such as cancer, obesity, and inherited and acquired disorders of hypercoagulation.  Ref: Cushman M. Epidemiology and risk factors for venous thrombosis. Semin Hematol. 2007;44(2):62-69. doi:10.1053/j.seminhematol.2007.02.004 CLICK HERE FOR MORE MCQs  

# Commonest inherited cause of thrombosis in Caucasians is: a. Protein S deficiency b. Factor V leiden mutation c. Anti thrombin III deficiency d. Protein C deficiency The correct answer is B. Factor V Leiden mutation. Factor V Leiden (G1691A or arg 506 glu substitution) and prothrombin (G 20210 A) are rare in African and orientals but they have prevalence in whites, highest prevalence of heterozygotes (11–14%) is reported in Sweden and Arabs. CLICK HERE FOR MORE MCQs

 # Which of the following is the strongest activator of platelet?  a. Thrombin  b. Serotonin  c. Thromboxane A2  d. Epinephrine The correct answer is: A. Thrombin. Strong activator: Thrombin Collagen ADP, Shear Weak: Epinephrine Thromboxane A2/Prostoglandin H2 Serotonin Platelet activating factor Vasopressin Thrombospondin-1 Thrombolytic agent CLICK HERE FOR MORE MCQs

# Most common cause of thrombocytopenia in children is: a. Aplastic anemia  b. ITP c. TTP  d. Drug induced The correct answer is B. ITP. ITP is the most common cause of acquired severe thrombocytopenia and 50% of ITP cases are children, i.e. < 10 years of age.  CLICK HERE FOR MORE MCQs

 # One unit of random donor platelet ideally increases the platelet count in an adult by:  a. 5000  b. 10000  c. 15000  d. 20000 The correct answer is: a. 5000. The increment in platelet count depends on many factors but if all other factors are absent then 1 unit of whole blood derived random platelet increases the platelet count by 5,000/mm3 per square metre. So in a person of BSA 2 m2. It should raise by 10000/mm3 and of 1.5 m2 by 7500/mm3 respectively.  CLICK HERE FOR MORE MCQs

 # Which of the following can be given safely in pregnancy?  a. Imatinib  b. Heparin  c. Warfarin  d. Thalidomide The correct answer is B. Heparin. Human Teratogenic Drugs - Drugs causing human birth defect Thalidomide – Phocomelia, multiple defects All anticancer drugs – Multiple defects, fetal death Androgens – Virilization, limb, esophageal, cardiac defects Progestins – Virilization of female fetus Tetracycline – Discolored and deformed teeth, retarded bone growth Warfarin – Nose, eye and hand defects, growth retardation Phenytion – Hypoplastic phalanges, cleft lip/palate microcephaly Phenobarbitone – Various malformations Chlorpromazine – Neural tube defects Valproate sodium – Spina bifida and other normal tube defects Lithium – Fetal goitre, cardiac and other abnormalities Isotretinoin – Craniofacial, heart and CVS defects Imatinib – Multiple defects exomphalos, kidney abnormalities CLICK HERE FOR MORE MCQs