Biochemistry
2 questionsIn which type of hemoglobin are zeta 2 and gamma 2 chains present?
Which of the following is required for proper effects of Insulin?
NEET-PG 2015 - Biochemistry NEET-PG Practice Questions and MCQs
Question 941: In which type of hemoglobin are zeta 2 and gamma 2 chains present?
- A. Gower I
- B. Gower II
- C. Portland (Correct Answer)
- D. Fetal hemoglobin
Explanation: ***Portland*** - **Portland hemoglobin** is a primitive embryonic hemoglobin composed of **zeta (ζ) 2 and gamma (γ) 2 chains** (ζ2γ2). - It plays a role in early fetal oxygen transport, particularly in the yolk sac stage. *Gower I* - **Gower I hemoglobin** is another embryonic hemoglobin, but it consists of **zeta (ζ) 2 and epsilon (ε) 2 chains** (ζ2ε2). - This composition is crucial for oxygen delivery during the very initial stages of embryonic development. *Gower II* - **Gower II hemoglobin** is an embryonic hemoglobin made up of **alpha (α) 2 and epsilon (ε) 2 chains** (α2ε2). - It represents a transitional form as the embryo develops and starts producing alpha globin chains. *Fetal hemoglobin* - **Fetal hemoglobin (HbF)** consists of **alpha (α) 2 and gamma (γ) 2 chains** (α2γ2). - It is the predominant hemoglobin during the second and third trimesters of pregnancy and has a higher affinity for oxygen than adult hemoglobin.
Question 942: Which of the following is required for proper effects of Insulin?
- A. Chromium (Correct Answer)
- B. Selenium
- C. Copper
- D. Iron
Explanation: ***Chromium*** - **Chromium** is an essential trace mineral that plays a crucial role in enhancing the action of **insulin** by promoting its binding to cell receptors. - It is a key component of **glucose tolerance factor (GTF)**, which helps cells absorb glucose more efficiently. *Selenium* - **Selenium** is an antioxidant and is involved in thyroid hormone metabolism and immune function, but it does not directly facilitate insulin action. - While important for overall health, it has no known direct requirement for the proper effects of insulin. *Copper* - **Copper** is involved in various enzymatic reactions, iron metabolism, and connective tissue formation, but it is not directly required for insulin's proper function. - High levels of **copper** can even negatively impact glucose metabolism in some contexts. *Iron* - **Iron** is essential for oxygen transport in hemoglobin and myoglobin, as well as for many enzymatic processes, but it does not directly enhance insulin sensitivity or action [1]. - Both **iron deficiency** and **iron overload** can indirectly affect metabolic health but do not directly influence insulin's effects in the same way chromium does [2].
Internal Medicine
6 questionsWhich of the following statements about CNS leukemia is false?
Thrombocythemia is characterized by an elevated platelet count.
In a patient with hypoglycemia, what is the appropriate dose adjustment of insulin?
What is the best indicator for assessing short-term control of blood glucose levels over a period of 2-3 weeks?
What is the recommended postprandial capillary glucose level (in mg/dl) for adequate diabetes control?
Hyperpigmentation is seen with which hormone?
NEET-PG 2015 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 941: Which of the following statements about CNS leukemia is false?
- A. Intrathecal methotrexate is given
- B. Seen with acute myeloid leukemia
- C. CNS irradiation is given
- D. Single blast in CSF is sufficient for diagnosis (Correct Answer)
Explanation: ***Seen with acute myeloid leukemia*** - CNS involvement is typically not a common feature of **acute myeloid leukemia (AML)**; it's more associated with acute lymphoblastic leukemia (ALL) [1]. - While leukemia can affect the CNS, **AML is not predominantly known** for this complication compared to ALL . *Single blast in CSF is sufficient for diagnosis* - A **single blast** in the cerebrospinal fluid (CSF) does **not establish a definitive diagnosis** of CNS leukemia; multiple blasts are typically required. - Diagnosis involves considering clinical symptoms, laboratory findings, and often requires **a combination of findings** to confirm CNS involvement. *Intrathecal methotrexate is given* - **Intrathecal methotrexate** is used for treatment of CNS leukemia; however, this statement is true and does not meet the 'except' criteria. - It is a common practice to deliver chemotherapy directly to the CNS to combat leukemia effectively. *CNS irradiation is given* - CNS irradiation can be used as a treatment modality in certain instances of leukemia; thus, this statement is also true. - It is part of the therapeutic strategies for managing CNS involvement but is not universally applied for all cases.
Question 942: Thrombocythemia is characterized by an elevated platelet count.
- A. Low platelets
- B. Neutrophilia
- C. Monocytosis
- D. Elevated platelet count (Correct Answer)
Explanation: Elevated platelet count - Thrombocythemia is a condition specifically defined by an abnormally high number of platelets (thrombocytes) in the blood [2]. - This elevated count can lead to issues with both bleeding and clotting [2]. Low platelets - Low platelets, also known as thrombocytopenia, is the opposite of thrombocythemia [1]. - This condition is associated with an increased risk of bleeding [1]. Neutrophilia - Neutrophilia refers to an elevated count of neutrophils, a type of white blood cell, which is typically seen in bacterial infections. - It does not directly describe the platelet count. Monocytosis - Monocytosis indicates an increase in monocytes, another type of white blood cell, often seen in chronic infections or inflammatory conditions. - This term is unrelated to platelet levels.
Question 943: In a patient with hypoglycemia, what is the appropriate dose adjustment of insulin?
- A. Increase insulin dosage
- B. Decrease insulin dosage (Correct Answer)
- C. Maintain current insulin dosage
- D. Add a different medication
Explanation: ***Decrease insulin dosage*** - Hypoglycemia indicates that the current insulin dose is too high, causing blood glucose levels to drop excessively [1]. - Reducing the insulin dosage helps prevent future episodes of low blood sugar by allowing blood glucose to remain within a healthier range [1]. *Increase insulin dosage* - Increasing insulin would further lower blood glucose, exacerbating the **hypoglycemia** and potentially leading to a more severe and dangerous state. - This action is appropriate for **hyperglycemia**, not hypoglycemia. *Maintain current insulin dosage* - Maintaining the current dose would not address the problem, as it has already proven to be too much for the patient, causing the **hypoglycemic episodes** [1]. - This approach would leave the patient at continued risk for recurrent hypoglycemia. *Add a different medication* - While other medications might be used in diabetes management, adding a new one without adjusting the existing insulin dose could further complicate blood glucose control. - The immediate and most direct action for **hypoglycemia** caused by insulin is to adjust the insulin itself [1].
Question 944: What is the best indicator for assessing short-term control of blood glucose levels over a period of 2-3 weeks?
- A. Serum fructosamine (Correct Answer)
- B. Blood sugar
- C. Urine sugar
- D. HbA1c
Explanation: ***Serum fructosamine*** - **Fructosamine** reflects the glycation of serum proteins, primarily albumin, which has a shorter half-life (around 17-20 days) compared to hemoglobin. - This allows it to assess average blood glucose control over the preceding **2-3 weeks**, making it suitable for short-term monitoring. *HbA1c* - **HbA1c** (glycated hemoglobin) reflects average blood glucose levels over the lifespan of red blood cells, typically **2-3 months** [1]. - While an excellent long-term indicator, its longer time frame makes it less suitable for assessing short-term changes over just 2-3 weeks [1]. *Blood sugar* - A single **blood sugar** measurement (fasting or random) provides an instantaneous snapshot of glucose levels at that specific moment [2]. - It does not reflect average glucose control over a period of 2-3 weeks and is highly influenced by recent food intake and activity [2]. *Urine sugar* - **Urine sugar** levels indicate that the kidney's reabsorption capacity for glucose has been exceeded, resulting in glucose spilling into the urine [3]. - This is a qualitative or semi-quantitative measure that primarily reflects very high blood glucose levels and is not a reliable indicator of averaged glucose control over any specific time frame [3].
Question 945: What is the recommended postprandial capillary glucose level (in mg/dl) for adequate diabetes control?
- A. < 180 mg/dl (Correct Answer)
- B. < 200 mg/dl
- C. < 100 mg/dl
- D. < 140 mg/dl
Explanation: ***< 180 mg/dl*** - This is the **recommended target** for postprandial (1-2 hours after a meal) capillary glucose levels in most non-pregnant adults with diabetes to achieve **adequate glycemic control** [1], [2]. - Maintaining levels below 180 mg/dl helps to minimize the risk of **long-term microvascular and macrovascular complications**. *< 100 mg/dl* - While this is an ideal fasting glucose level, it is generally **too low for postprandial glucose**, and attempting to maintain such levels might increase the risk of **hypoglycemia** in many patients with diabetes [1]. - This target is more appropriate for **fasting or pre-meal glucose** goals. *< 140 mg/dl* - This is a **more stringent target** that may be appropriate for some individuals with diabetes, particularly those who are carefully managed and at low risk of hypoglycemia. - However, for the general population with diabetes, **< 180 mg/dl is the more commonly accepted and achievable goal** for postprandial readings [2]. *< 200 mg/dl* - A postprandial glucose level of < 200 mg/dl is considered **good control** in some contexts, but it's often a **less strict target** than < 180 mg/dl for optimal long-term management. - While better than uncontrolled high levels, consistently approaching 200 mg/dl may still contribute to **increased risk of complications** over time compared to tighter control.
Question 946: Hyperpigmentation is seen with which hormone?
- A. TSH
- B. ACTH (Correct Answer)
- C. FSH
- D. LH
Explanation: ***ACTH*** - In conditions like **Addison's disease**, the adrenal glands' inability to produce cortisol leads to increased **ACTH** (adrenocorticotropic hormone) secretion due to a lack of negative feedback [3], [4]. - ACTH is derived from proopiomelanocortin (POMC), which also gives rise to alpha-melanocyte-stimulating hormone (α-MSH). Elevated ACTH levels can thus stimulate melanocytes, causing **hyperpigmentation** in skin folds, buccal mucosa, and pressure points [4]. *FSH* - **FSH** (follicle-stimulating hormone) primarily regulates the development of **follicles in the ovaries** and sperm production in the testes [1]. - There is no known direct association between excessive FSH levels and **hyperpigmentation**. *TSH* - **TSH** (thyroid-stimulating hormone) stimulates the **thyroid gland** to produce thyroid hormones (T3 and T4) [1]. - While thyroid disorders can affect skin texture and moisture, there is no direct link between elevated TSH and **hyperpigmentation**. *LH* - **LH** (luteinizing hormone) plays a key role in **ovulation** in females and testosterone production in males [2]. - High LH levels are not associated with **hyperpigmentation**.
Pathology
2 questionsThe Ham test is specifically used for diagnosing paroxysmal nocturnal hemoglobinuria (PNH) and is based upon:
The tissue of origin of the Kaposi's sarcoma is
NEET-PG 2015 - Pathology NEET-PG Practice Questions and MCQs
Question 941: The Ham test is specifically used for diagnosing paroxysmal nocturnal hemoglobinuria (PNH) and is based upon:
- A. GPI Anchor Proteins
- B. Complement (Correct Answer)
- C. Spectrin protein
- D. Mannose binding proteins
Explanation: ***Complement*** - The HAM test is based on the activation of the **complement system** which enhances the opsonization and clearance of immune complexes [1]. - It is used in the diagnosis of certain conditions, notably those associated with **hemolytic anemia** due to complement fixation. *GPI Anchor Proteins* - GPI anchor proteins are involved in anchoring proteins to cell membranes but are **not related to the HAM test**. - This oes not explain the **mechanism** or purpose of the HAM test. *Mannose binding proteins* - Mannose binding lectins play a role in **innate immunity** but are not the basis of the HAM test. - They function in the **opsonization of pathogens**, which is unrelated to the complement activation aspect of the HAM test. *Spectrin protein* - Spectrin is a cytoskeletal protein that contributes to the integrity of cell membranes, particularly in red blood cells. - It does not relate to the **mechanism of the HAM test**, which focuses on complement involvement. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 99-100.
Question 942: The tissue of origin of the Kaposi's sarcoma is
- A. Lymphoid
- B. Vascular (Correct Answer)
- C. Neural
- D. Muscular
Explanation: ***Vascular*** - Kaposi's sarcoma originates from the **vascular tissue**, specifically from endothelial cells lining blood vessels [2]. - The lesions are characterized by **angiogenesis**, leading to the formation of vascular tumors with dilated endothelial cell-lined vascular spaces [1]. *Muscular* - Muscular tissue is involved in **voluntary** and **involuntary movements** but is not related to the etiology of Kaposi's sarcoma. - This condition does not arise from **muscle cells** or any muscular components. *Neural* - Neural tissue consists of **neurons** and **glial cells**, which are not implicated in Kaposi's sarcoma. - Kaposi's sarcoma does not originate from any **neural structures** or pathologies. *Lymphoid* - Lymphoid tissue primarily concerns the immune system, particularly the **lymphatic system**, and does not give rise to Kaposi's sarcoma. - This malignancy does not derive from **lymphoid components** like lymphocytes or lymph nodes. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 526-527. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Cardiovascular Disease, pp. 282-283.