Best provocative test for diagnosis of Gastrinoma is:
Chemotherapeutic Agent of Choice for the treatment of CML?
A pregnant woman is diagnosed with Graves' disease. The most appropriate therapy for her would be:
Hypophosphatemia is seen in:
Which of the following diseases is NOT associated with Anti-Neutrophil Cytoplasmic Antibodies (ANCA)?
Neurofibromatosis true all, except-
Which of the following provide protection against malaria except
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 101: Best provocative test for diagnosis of Gastrinoma is:
- A. Ca++ infusion test
- B. Secretin injection test (Correct Answer)
- C. ACTH stimulation test
- D. Steroid assay
Explanation: ***Secretin injection test*** - The **secretin injection test** is the most reliable provocative test for gastrinoma, leading to a paradoxical increase in gastrin levels [1]. - In normal individuals, secretin suppresses gastrin release, but in gastrinoma, it stimulates **gastrin secretion** [1]. *Ca++ infusion test* - The **calcium infusion test** can also stimulate gastrin release in gastrinoma patients, but it is less specific and potentially more risky than the secretin test due to potential side effects like cardiac arrhythmias. - It involves infusing calcium gluconate to observe any uncharacteristic rise in gastrin. *ACTH stimulation test* - The **ACTH stimulation test** is used to evaluate adrenal gland function, particularly in suspected cases of adrenal insufficiency or hypercortisolism [2]. - It does not have any direct relevance to the diagnosis of **gastrinoma**. *Steroid assay* - **Steroid assays** measure levels of various steroid hormones (e.g., cortisol, aldosterone) in the body to assess adrenal or gonadal function. - This test is not used for diagnosing **gastrinoma**.
Question 102: Chemotherapeutic Agent of Choice for the treatment of CML?
- A. Imatinib (Correct Answer)
- B. Vincristine
- C. Cyclophosphamide
- D. Methotrexate
Explanation: ***Imatinib*** - **Imatinib** is a **tyrosine kinase inhibitor** specifically targeting the **BCR-ABL fusion protein**, which is the hallmark of CML [1][2]. - It dramatically improved the prognosis of CML patients, making it the **first-line therapy** and agent of choice due to its high efficacy and relatively low toxicity compared to conventional chemotherapy [2]. *Vincristine* - **Vincristine** is a **vinca alkaloid** that inhibits microtubule formation, primarily used in acute leukemias and lymphomas. - It is not the agent of choice for CML due to its different mechanism of action and the availability of more targeted therapies for CML. *Cyclophosphamide* - **Cyclophosphamide** is an **alkylating agent** that causes DNA damage, used in various cancers and autoimmune diseases. - While it can be used in some hematologic malignancies, it is not the preferred or most effective treatment for CML, especially given the success of targeted therapies. *Methotrexate* - **Methotrexate** is an **antimetabolite** that interferes with DNA synthesis, commonly used in acute leukemias, lymphomas, and autoimmune conditions. - It is not considered the chemotherapeutic agent of choice for CML, as its mechanism of action is not specific to the BCR-ABL anomaly characteristic of CML.
Question 103: A pregnant woman is diagnosed with Graves' disease. The most appropriate therapy for her would be:
- A. Radioiodine therapy
- B. Total thyroidectomy
- C. Carbimazole parenteral
- D. Propylthiouracil oral (Correct Answer)
Explanation: ***Propylthiouracil oral*** - **Propylthiouracil (PTU)** is the preferred antithyroid drug during the **first trimester** of pregnancy due to a lower risk of teratogenicity compared to methimazole/carbimazole [1]. - It works by inhibiting both the synthesis of thyroid hormones and the peripheral conversion of **T4 to T3**. *Radioiodine therapy* - **Radioactive iodine** is absolutely contraindicated in pregnancy as it can cross the placenta and cause **fetal hypothyroidism or athyreosis**. - It leads to permanent destruction of the thyroid gland and is not suitable for a temporary condition in a pregnant woman. *Total thyroidectomy* - While thyroidectomy can be considered for Graves' disease in pregnancy, it is generally reserved for cases where antithyroid drugs are not tolerated or ineffective, or for very large goiters causing compressive symptoms. - It carries risks associated with **surgery and anesthesia** during pregnancy, and requires **lifelong thyroid hormone replacement**. *Carbimazole parenteral* - **Carbimazole** (which is metabolized to methimazole) is generally avoided in the **first trimester** due to an increased risk of teratogenicity, particularly **aplasia cutis**, omphalocele, and choanal atresia [1]. - While it can be used in the second and third trimesters, **PTU is preferred in the first trimester**, and carbimazole is not typically administered parenterally.
Question 104: Hypophosphatemia is seen in:
- A. Hyperthyroidism
- B. Hypoparathyroidism
- C. Hyperparathyroidism (Correct Answer)
- D. Pseudohypoparathyroidism
Explanation: ***Hyperparathyroidism*** - In **primary hyperparathyroidism**, the excess **parathyroid hormone (PTH)** leads to increased phosphate excretion by the kidneys [1], [4]. - This results in **hypophosphatemia** as the body attempts to maintain **calcium-phosphate balance**, often at the expense of phosphate levels [1]. *Hyperthyroidism* - While hyperthyroidism can affect **bone metabolism**, it is typically associated with **normal or slightly elevated phosphate levels**, not hypophosphatemia [3]. - The main electrolyte disturbances are usually related to **calcium** (e.g., hypercalcemia) due to increased bone turnover [3]. *Hypoparathyroidism* - **Hypoparathyroidism** is characterized by **low or absent PTH**, leading to decreased renal phosphate excretion. - This results in **hyperphosphatemia**, along with **hypocalcemia** [2]. *Pseudohypoparathyroidism* - In **pseudohypoparathyroidism**, there is **PTH resistance** at target tissues, even with high or normal PTH levels [2]. - This leads to symptoms resembling hypoparathyroidism, including **hyperphosphatemia** and **hypocalcemia** [2].
Question 105: Which of the following diseases is NOT associated with Anti-Neutrophil Cytoplasmic Antibodies (ANCA)?
- A. Wegener's granulomatosis
- B. Henoch schonlein purpura (Correct Answer)
- C. Microscopic PAN
- D. Churg Strauss syndrome
Explanation: ***Henoch schonlein purpura*** - **Henoch-Schönlein purpura (HSP)** is not associated with **ANCA**; it primarily involves IgA deposition [1]. - Commonly presents with **purpura**, **abdominal pain**, and **glomerulonephritis**, differentiating it from ANCA-associated vasculitides [1]. *Wegener's granulomatosis* - **Wegener's granulomatosis**, now known as **Granulomatosis with polyangiitis**, is strongly associated with **c-ANCA** and anti-PR3 antibodies. - It typically presents with **respiratory** and **renal symptoms** due to vasculitis [2]. *Microscopic PAN* - **Microscopic polyangiitis (PAN)** is associated with **p-ANCA** and myeloperoxidase (MPO) antibodies. - It leads to **glomerulonephritis** and **pulmonary hemorrhage**, indicating its vasculitic nature. *Churg Strauss syndrome* - **Churg-Strauss syndrome**, or **Eosinophilic Granulomatosis with Polyangiitis**, is associated with **p-ANCA** and perinuclear staining [1]. - Often presents with **asthma**, **eosinophilia**, and systemic vasculitis affecting multiple organs [1].
Question 106: Neurofibromatosis true all, except-
- A. Associated with cataract
- B. Multiple fibroma
- C. Autosomal recessive (Correct Answer)
- D. Scoliosis
Explanation: Autosomal recessive - Neurofibromatosis types 1 and 2 are autosomal dominant disorders, not autosomal recessive. - This indicates that only one copy of the mutated gene is sufficient to cause the condition, and it can be passed from one affected parent to their children with a 50% probability. Associated with cataract - Juvenile posterior subcapsular cataracts are a known ocular manifestation, particularly in Neurofibromatosis type 2 (NF2). - This is a common finding and one of the diagnostic criteria for NF2. Multiple fibroma - Neurofibromas (benign tumors of peripheral nerves) are characteristic features of Neurofibromatosis type 1 (NF1). - These can be cutaneous, subcutaneous, or plexiform and are often numerous. Scoliosis - Scoliosis (curvature of the spine) is a common musculoskeletal complication associated with Neurofibromatosis, especially NF1. - It can be dystrophic or non-dystrophic and may require surgical intervention in severe cases.
Question 107: Which of the following provide protection against malaria except
- A. Thalassemia
- B. PNH (Correct Answer)
- C. Sickle cell anemia
- D. Duffy blood group
Explanation: ***PNH*** - **Paroxysmal nocturnal hemoglobinuria (PNH)** is a rare, acquired clonal disorder of hematopoietic stem cells characterized by complement-mediated hemolysis. - It does not offer any known protective advantage against malaria infection; in fact, chronic hemolysis could potentially complicate malaria diagnosis or management. *Thalassemia* - Individuals with **thalassemia traits (heterozygotes)**, particularly alpha-thalassemia, have red blood cells that are more resistant to malarial parasite invasion and growth [1]. - This protection is thought to arise from altered red cell morphology, reduced parasite multiplication, and enhanced clearance of infected cells. *Sickle cell anemia* - The **heterozygous state (sickle cell trait)** provides significant protection against severe malaria, as the altered hemoglobin S in red blood cells inhibits parasite growth and promotes early clearance of infected cells [1], [2]. - Although the homozygous state (sickle cell anemia) can be severe, even carriers benefit from reduced malaria susceptibility. *Duffy blood group* - Absence of the **Duffy antigen on red blood cells**, common in West African populations, provides complete protection against infection with **Plasmodium vivax** malaria. - The Duffy antigen receptor is essential for *P. vivax* to invade human red blood cells.