Diabetes insipidus occur due to lack of:

# Diabetes insipidus occur due to lack of:

A. Insulin

B. Antidiuretic hormone

C. ACTH

D. Thyroxin

The correct answer is B. Antidiuretic hormone.

The neurohypophysis， or posterior pituitary， is formed by axons that originate in large cell bodies in the supraoptic and paraventricular nuclei of the hypothalamus. It produces two hormones: ( 1 ) arginine

vasopressin (AVP)， also known as antidiuretic hormone， and (2) oxytocin. AVP acts on the renal tubulω to reduce water loss by con centrating the urine. Oxytocin stimulates postpartum milk letdown in response to suckling. A deficiency of AVP secretion or action causes diabetes insipidus (DI)，a syndrome characterized by the production of large amounts of dilute urine. Exιessive or inappropriate AVP production impairs urinary water excretion and predisposes to hyponatremia if water intake is not reduced in parallel with urine output.

Reference: Harrison's Principles of Internal Medicine, 19th Edition, Page no: 2274

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In jaundice there is an unconjugated hyperbilirubinemia which is most likely due to:

 # In jaundice there is an unconjugated hyperbilirubinemia which is most likely due to:

A. Hepatitis

B. Cirrhosis

C. Obstruction of bile in canaliculi

D. Increased breakdown of red cells

The correct answer is D. Increased breakdown of red cells.

Hemolysis Increased destruction of erythrocytes leads to increased bilirubin turnover and unconjugated hyperbilirubinemia; the hyperbilirubinemia is usually modest in the presence of normal liver function.

In particular，the bone marrow is only capable of a sustained eightfold increase in erythrocyte production in response to a hemoIytic stress. Therefore， hemolysis alone cannot result in a sustained hyperbilirubinemia of more than -68 μmol/L (4 mg/dL) . Higher values imply concomitant hepatic dysfunction. When hemolysis is the only abnormality in an otherwise healthy individual， the result is a purely unconjugated hyperbilirubinemia，with the direct-reacting fraction as measured in a typical clinical laboratory being less or equal to 15% of the total serum bilirubin.

Reference: Harrison's Principles of Internal MEDICINE, 19th Edition Page no: 2000

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Pernicious anemia is due to deficiency of:

# Pernicious anemia is due to deficiency of:

A. Iron

B. Cobalamine

C. Folic acid

D. Niacin

The correct answer is B. Cobalamine.

Pernicious anemia is a relatively common chronic hematologic disease. It is an adult form of anemia that is associated with gastric atrophy and a loss of intrinsic factor production in gastric secretions and a rare congenital autosomal recessive form in which intrinsic factor (IF) production is lacking without gastric atrophy. The term pernicious anemia is reserved for patients with vitamin B12 deficiency due to a lack of production of IF in the stomach. Intrinsic factor in gastric secretions is necessary for the absorption of dietary vitamin B12. Vitamin B12, a substance now thought to be synonymous with the ‘erythrocyte-maturing factor’ or ‘hemopoietic principle’ and present in many foods, particularly liver, beef, milk and dairy products. Body stores of the vitamin usually exceed 1000 mcg and the daily requirement is about 1 mcg.

Reference: Shafer’s Textbook of ORAL PATHOLOGY, Seventh Edition, Page 762

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Common site of carcinoma of tongue is:

 # Common site of carcinoma of tongue is:

A. Apical

B. Lateral borders

C. Dorsum

D. Posterior 1/3rd 

The correct answer is B. Lateral borders.

The typical lesion develops on the lateral border or ventral surface of the tongue. When, in rare cases, carcinoma occurs on the dorsum of the tongue, it is usually in a patient with a past or present history of syphilitic glossitis. In a series of 1,554 cases of carcinoma of the tongue reported by Frazell and Lucas, only 4% occurred on the dorsum. The lesions on the lateral border are rather equally distributed between the base of the tongue, the anterior third and the mid portion, although in the above series 45% of cases occurred on the middle third. Lesions near the base of the tongue are particularly insidious, since they may be asymptomatic until far advanced. Even then the only presenting manifestations may be a sore throat and dysphagia. The specific site of development of these tumors is of great significance, since the lesions on the posterior portion of the tongue are usually of a higher grade of malignancy, metastasize earlier and offer a poorer prognosis, especially because of their inaccessibility for treatment.

Reference: Shafer’s Textbook of ORAL PATHOLOGY, Seventh Edition, Page no: 116

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What is best for factor VIII replacement in Hemophilia A:

 # What is best for factor VIII replacement in Hemophilia A?

A. Fresh frozen plasma

B. Cryoprecipitate

C. Whole blood

D. Platelets

The correct answer is B. Cryoprecipitate.

Cryoprecipitate is a source of fibrinogen， factor VIII，and von Willebrand factor (VWF). It is ideal for supplying fibrinogen to the volume-sensitive patient. When factor VIII concentrates are not

available， cryoprecipitate may be used because each unit contains approximately 80 units of factor VIII. Cryoprecipitate may also supply VWF to patients with dysfunctional (type II) or absent (type III) von Willebrand's disease. 

Reference: Harrison's Principles of Internal Medicine, 19th Edition, Page no: 138e-3

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Which deficiency affects tooth development?

 # Which deficiency affects tooth development?

A. Vitamin A

B. Carbohydrates

C. Vitamin E

D. Vitamin B

The correct answer is A. Vitamin A.

In vitamin A deficiency the ameloblasts fail to differentiate properly. Consequently, their organizing influence on the adjacent mesenchymal cells is disturbed, and atypical dentin, known as osteodentin, is formed.

Reference: Orban’s Oral Histology and Embryology, Thirteenth Edition, Page no 46

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A child with fever of 102 degrees F and vesicles in the oral cavity is probably suffering from:

 # A child with fever of 102 degrees F and vesicles in the oral cavity is probably suffering from:

A. Herpes Simplex type I

B. Juvenile periodontitis

C. Acute herpetic gingivostomatitis

D. Neutropenia

The correct answer is C. Acute Herpetic Gingivostomatitis.

In some preschool children the primary infection of Herpes Simplex virus may be characterized by only one or two mild sores on the oral mucous membranes, which may be of little concern to the child or may go unnoticed by the parents. In other children the primary infection may be manifested by acute symptoms (acute herpetic gingivostomatitis). The active symptoms of the acute disease can occur in children with clean mouths and healthy oral tissues. The symptoms of the disease develop suddenly and include, in addition to the fiery red gingival tissues, malaise, irritability, headache, and pain associated with the intake of food and liquids of acidic content. A characteristic oral finding in the acute primary disease is the presence of yellow or white liquid-filled vesicles. In a few days the vesicles rupture and form painful ulcers, 1 to 3 mm in diameter, which are covered with a whitish gray membrane and have a circumscribed area of inflammation. The ulcers may be observed on any area of the mucous membrane, including buccal mucosa, tongue, lips, hard and soft palate, and the tonsillar areas. Large ulcerated lesions may occasionally be observed on the palate or gingival tissues or in the region of the mucobuccal fold. This distribution makes the differential diagnosis more difficult. An additional diagnostic criterion is a fourfold rise of serum antibodies to HSV-1. The lesion culture also shows positive results for HSV-1.

Reference: McDONALD AND AVERY’S DENTISTRY FOR THE CHILD AND

ADOLESCENT, TENTH EDITION, Page no 246.

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