Novel Therapeutic Approaches — MCQs

10 questions

Regeneration is characterized by:

Choose the correct options regarding the route of administration and bioavailability. A- Intravenous =1 B- 0.75< Oral <1 C-0.75 <IM ≤ 1 D- 0.75<SC ≤ 1 IM - Intramuscular SC- Subcutaneous

Major mechanism of transport of drugs across biological membranes is:

Before the advent of tyrosine kinase inhibitors, the most effective treatment of chronic myeloid leukemia was:

Which of the following is a monoclonal antibody used in cancer treatment?

Stem cells in skin are found in all, EXCEPT:

Which of the following treatments are recommended for a pregnant woman suffering from sickle cell disease ? I. Folic acid 1 mg daily II. Azathioprine III. Penicillin prophylaxis IV. Thromboprophylaxis with low molecular weight heparin Select the correct answer using the code given below :

Association of sexual precocity, multiple cystic bone lesions and endocrinopathies are seen in:

40-year-old patient having arthritis of PIP and DIP along with carpometacarpal joint of thumb and sparing of wrist and metacarpophalangeal joint, most likely diagnosis is

Q10

A35 yr old lady with Normal PT and increased aPTT. 2 year back, she was operated for cholecystectomy & did not have any bleeding episode. What is next investigation for clinical diagnosis -

Novel Therapeutic Approaches Indian Medical PG Practice Questions and MCQs

Question 1: Regeneration is characterized by:

A. Granulation tissue
B. Repairing by different type of tissue
C. Cellular proliferation is largely regulated by biochemical factors
D. Repairing by same type of tissue (Correct Answer)

Explanation: ***Repairing by same type of tissue*** - **Regeneration** involves the replacement of damaged cells and tissues with cells of the **same type**, leading to a complete restoration of normal structure and function [1]. - This process is seen in tissues with high proliferative capacity, like the **epidermis** or the **liver**, following injury [2]. *Granulation tissue* - **Granulation tissue** is characteristic of **repair by fibrosis** (scar formation), not regeneration [1]. - It consists of proliferating fibroblasts, new blood vessels (angiogenesis), and inflammatory cells, which eventually mature into a fibrous scar. *Repairing by different type of tissue* - The replacement of damaged tissue with a **different type of tissue** (typically fibrous connective tissue) is known as **repair by fibrosis** or **scar formation** [1]. - This occurs when the tissue's regenerative capacity is limited or when the injury is severe, resulting in the loss of normal tissue architecture and function [3]. *Cellular proliferation is largely regulated by biochemical factors* - While **cellular proliferation** is indeed regulated by **biochemical factors** (growth factors, cytokines) in both regeneration and repair, this statement describes a mechanism common to cellular growth and healing in general, not a defining characteristic unique to regeneration [1]. - This regulation guides both the replacement with original tissue (regeneration) and scar formation, so it's not specific enough to define regeneration alone. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 113-115. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 112-113. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, p. 113.

Question 2: Choose the correct options regarding the route of administration and bioavailability. A- Intravenous =1 B- 0.75< Oral <1 C-0.75 <IM ≤ 1 D- 0.75<SC ≤ 1 IM - Intramuscular SC- Subcutaneous

A. A and D
B. A and C
C. A, C, D (Correct Answer)
D. A, B, D

Explanation: ***A, C, D*** - Intravenous (IV) administration has **100% bioavailability** because the drug enters the systemic circulation directly, bypassing any absorption barriers. - Intramuscular (IM) and subcutaneous (SC) routes generally have **high bioavailability**, often between 75% and 100%, as drugs are absorbed directly into the bloodstream without first-pass metabolism. *A and D* - While options A and D are correct, this choice is incomplete as option C is also a correct statement regarding bioavailability. - IM administration typically results in high systemic bioavailability, similar to SC, making its exclusion here incorrect. *A and C* - While options A and C are correct, this choice is incomplete as option D is also a correct statement regarding bioavailability. - Subcutaneous administration also generally results in high bioavailability, as absorption tends to be complete. *A, B, D* - While options A and D are correct, option B is typically incorrect for oral bioavailability. - Oral bioavailability of many drugs is often less than 0.75 (75%) due to factors like **first-pass metabolism** and incomplete absorption in the gastrointestinal tract.

Question 3: Major mechanism of transport of drugs across biological membranes is:

A. Passive diffusion (Correct Answer)
B. Facilitated diffusion
C. Active transport
D. Endocytosis

Explanation: ***Passive diffusion*** - This is the **most common mechanism** for drug transport across biological membranes, especially for **lipid-soluble** drugs. - It occurs down a **concentration gradient** and does not require energy or carrier proteins. *Facilitated diffusion* - This process requires **carrier proteins** to move drugs across membranes, but it still occurs down a **concentration gradient** and does not consume energy directly. - It handles substances that are **too large or too polar** to cross by passive diffusion, but it is not the primary mechanism for most drugs. *Active transport* - This mechanism uses **carrier proteins** and **expends energy (ATP)** to move drugs against their **concentration gradient**. - It is important for the transport of specific drugs, but it is not the predominant mode for the majority of drug molecules. *Endocytosis* - This involves the **engulfment of large molecules** or particles by the cell membrane, forming vesicles. - It is a less common mechanism for drug absorption, primarily used for **very large molecules** like proteins or nanoparticles.

Question 4: Before the advent of tyrosine kinase inhibitors, the most effective treatment of chronic myeloid leukemia was:

A. Chemotherapy
B. Hydroxyurea and interferon
C. Haploidentical bone marrow transplant
D. Allogeneic bone marrow transplant (Correct Answer)

Explanation: ***Allogeneic bone marrow transplant*** - Before the advent of TKIs, **allogeneic hematopoietic stem cell transplantation (HSCT)** was the only curative treatment for CML [1]. - It involved replacing the patient's diseased bone marrow with healthy stem cells from a genetically matched donor, thereby eradicating the **Philadelphia chromosome-positive clone** [1]. *Haploidentical bone marrow transplant* - While a form of HSCT, **haploidentical transplants** were typically used as a backup option when a fully matched donor was unavailable due to higher risks of **graft-versus-host disease (GVHD)** and rejection. - It was not considered the most effective or preferred treatment before TKIs, being reserved for specific challenging cases. *Chemotherapy* - **Conventional chemotherapy** for CML, such as busulfan or hydroxyurea, primarily aimed at reducing the white blood cell count and controlling symptoms. - It was **palliative** and did not offer a cure or significantly prolong survival in the long term, unlike allogeneic HSCT [1]. *Hydroxyurea and interferon* - **Hydroxyurea** is a cytoreductive agent, and **interferon-alpha** was used to induce hematologic and cytogenetic responses in CML patients. - Although they provided some benefit in controlling the disease and improving survival compared to no treatment, they rarely achieved a cure and were associated with significant side effects, making them less effective than allogeneic HSCT [1].

Question 5: Which of the following is a monoclonal antibody used in cancer treatment?

A. Cisplatin
B. Rituximab (Correct Answer)
C. 5-fluorouracil
D. Methotrexate

Explanation: ***Rituximab*** - **Rituximab** is a **chimeric monoclonal antibody** that targets the **CD20 protein** found on the surface of normal and malignant **B lymphocytes**. - It is widely used in the treatment of various **lymphomas** and **leukemias**, as well as autoimmune diseases, by inducing the death of CD20-positive B cells. *Cisplatin* - **Cisplatin** is a **platinum-based chemotherapy drug** that works by forming **DNA adducts**, leading to DNA damage and apoptosis of cancer cells. - It is used in various solid tumors but is not a monoclonal antibody; it's a **cytotoxic agent**. *5-fluorouracil* - **5-fluorouracil (5-FU)** is an **antimetabolite chemotherapy drug** that interferes with DNA and RNA synthesis, thereby inhibiting cell division. - It is a **pyrimidine analog** and not a monoclonal antibody. *Methotrexate* - **Methotrexate** is a **folate analog antimetabolite** that inhibits **dihydrofolate reductase**, interfering with DNA synthesis and cell proliferation. - It's a conventional chemotherapy agent and immunosuppressant, not a monoclonal antibody.

Question 6: Stem cells in skin are found in all, EXCEPT:

A. Hair follicle
B. Sebaceous glands
C. Sweat glands
D. Stratum corneum (Correct Answer)

Explanation: ***Stratum corneum*** - The **stratum corneum** is the outermost layer of the epidermis consisting of **dead, anucleated keratinocytes** (corneocytes) that have undergone terminal differentiation [1]. - This layer contains **no viable cells** and therefore **no stem cells**, as it is composed entirely of flattened, keratinized cells that serve as a protective barrier [1]. - Stem cells require viable cellular machinery for self-renewal and differentiation, which is absent in this dead layer. *Hair follicle* - The **hair follicle bulge** region contains a population of multipotent **stem cells** responsible for hair regeneration and contributing to epidermal repair [1]. - These stem cells can differentiate into various cell types, including keratinocytes, sebocytes, and pigment cells [1]. *Sebaceous glands* - **Stem cells** are located in the **basal layer of sebaceous glands** and contribute to the maintenance and repair of the gland [1]. - These cells facilitate the continuous production of sebum and the structural integrity of the gland. *Sweat glands* - **Stem cells** are present in the **sweat glands**, particularly in the ductal regions, and play a role in the regeneration and repair of this glandular tissue [1]. - They are important for maintaining the function of eccrine and apocrine glands [1].

Question 7: Which of the following treatments are recommended for a pregnant woman suffering from sickle cell disease ? I. Folic acid 1 mg daily II. Azathioprine III. Penicillin prophylaxis IV. Thromboprophylaxis with low molecular weight heparin Select the correct answer using the code given below :

A. I, II and IV
B. I, III and IV (Correct Answer)
C. I, II and III
D. II, III and IV

Explanation: ***I, III and IV*** - **Folic acid 5 mg daily** (not 1mg) is essential in pregnancy, especially for women with **sickle cell disease**, to prevent **megaloblastic anemia** due to increased red cell turnover [1]. - **Penicillin prophylaxis** is crucial to prevent **Bacterial infections** as patients with sickle cell disease are at increased risk of infection, especially from encapsulated organisms, due to **functional asplenia** [1]. - **Thromboprophylaxis with low molecular weight heparin** is recommended because pregnancy in sickle cell disease significantly increases the risk of **venous thromboembolism** [1]. *I, II and IV* - **Azathioprine** is an immunosuppressant typically used for autoimmune conditions or organ transplantation, and it is **not a standard treatment** for managing sickle cell disease itself during pregnancy. - While folic acid and thromboprophylaxis are indicated, the inclusion of azathioprine makes this option incorrect. *I, II and III* - This option incorrectly includes **azathioprine**, an immunosuppressant not indicated for routine sickle cell management in pregnancy. - It also omits crucial **thromboprophylaxis**, which is vital given the increased risk of blood clots. *II, III and IV* - This option correctly includes **penicillin prophylaxis** and **thromboprophylaxis** but **incorrectly omits folic acid**, which is a cornerstone of daily management for all pregnant women with sickle cell disease. - It also incorrectly includes **azathioprine**, which is not a standard treatment.

Question 8: Association of sexual precocity, multiple cystic bone lesions and endocrinopathies are seen in:

A. McCune-Albright's syndrome (Correct Answer)
B. Hepatoblastoma
C. Androblastoma
D. Granulosa cell tumor

Explanation: ***McCune-Albright's syndrome*** - This syndrome is characterized by the classic triad of **precocious puberty**, **polyostotic fibrous dysplasia** (multiple cystic bone lesions), and **café-au-lait spots**. - It is caused by a somatic activating mutation in the **GNAS1 gene**, leading to constitutive activation of G protein-coupled receptors in affected tissues, resulting in hormonal overproduction and dysplastic changes. *Hepatoblastoma* - Hepatoblastoma is a **malignant liver tumor** primarily affecting infants and children. - While it can, in rare cases, produce human chorionic gonadotropin (hCG) causing precocious puberty, it is not typically associated with widespread cystic bone lesions or other endocrinopathies characteristic of McCune-Albright's. *Androblastoma* - An androblastoma (also known as a **Sertoli-Leydig cell tumor**) is a rare **gonadal stromal tumor** that secretes androgens. - It can cause **virilization** and, in prepubertal girls, precocious puberty, but it does not cause multiple cystic bone lesions or other systemic endocrine disorders as seen in McCune-Albright's. *Granulosa cell tumor* - Granulosa cell tumors are **ovarian stromal tumors** that can produce **estrogen**, leading to precocious puberty in young girls. - While they are a cause of precocious puberty, they do not typically present with the extensive cystic bone lesions or the full spectrum of endocrinopathies found in McCune-Albright's syndrome.

Question 9: 40-year-old patient having arthritis of PIP and DIP along with carpometacarpal joint of thumb and sparing of wrist and metacarpophalangeal joint, most likely diagnosis is

A. osteoarthritis (Correct Answer)
B. pseudo gout
C. psoriatic arthritis
D. rheumatoid arthritis

Explanation: ***Osteoarthritis*** - This classic presentation of arthritis in the **PIP, DIP**, and **first carpometacarpal (CMC) joint** with sparing of the wrist and MCP joints is highly characteristic of **osteoarthritis** [1]. - **Osteoarthritis** primarily affects cartilage and bone, leading to pain and stiffness, and commonly involves these specific hand joints [1]. *Pseudo gout* - Pseudo gout, or **calcium pyrophosphate deposition disease (CPPD)**, typically causes acute, monoarticular or oligoarticular arthritis, often affecting larger joints like the knee or wrist [3]. - While it can affect the hand, its presentation is usually more acute and less chronic, and it does not typically show the joint distribution described here. *Psoriatic arthritis* - **Psoriatic arthritis** can affect the DIP joints and can cause a "sausage digit" (dactylitis), but it often also involves the wrist or other joints, and skin/nail changes of psoriasis would typically be present. - While it can involve the DIP joints, the classic sparing of wrist and MCP for this specific pattern is less typical for psoriatic arthritis compared to osteoarthritis. *Rheumatoid arthritis* - **Rheumatoid arthritis** typically affects the **MCP joints** and **wrists symmetrically**, often sparing the DIP joints [2]. - The presented pattern of joint involvement, especially the sparing of the MCP and wrist joints and involvement of the DIP and CMC joints, makes rheumatoid arthritis unlikely [2].

Question 10: A35 yr old lady with Normal PT and increased aPTT. 2 year back, she was operated for cholecystectomy & did not have any bleeding episode. What is next investigation for clinical diagnosis -

A. Platelet aggregation test
B. Anti viper venom assay
C. Ristocetin cofactor assay
D. Factor VIII assay (Correct Answer)

Explanation: ***Factor VIII assay*** - An isolated **increased aPTT** with a **normal PT** points to an abnormality in the **intrinsic pathway** of coagulation, which includes Factor VIII [1]. - The absence of bleeding episodes for a cholecystectomy suggests a **mild deficiency** or a defect that doesn't cause severe hemorrhage, making Factor VIII deficiency (Hemophilia A) a strong consideration [2]. *Platelet aggregation test* - This test evaluates **platelet function**, abnormalities of which typically present with mucocutaneous bleeding and a normal PT and aPTT. - The patient's presentation of an isolated prolonged aPTT does not primarily suggest a platelet function disorder. *Anti viper venom assay* - This test is primarily used to detect the presence of **lupus anticoagulant**, which can cause a prolonged aPTT but is often associated with thrombotic events, not bleeding. - While lupus anticoagulant can prolong aPTT without bleeding, a Factor VIII deficiency is a more common cause of an isolated prolonged aPTT that is compatible with no significant bleeding history. *Ristocetin cofactor assay* - This assay is used to evaluate **von Willebrand factor (vWF)** activity, which is involved in platelet adhesion and also stabilizes Factor VIII [3]. - While vWF deficiency can cause a prolonged aPTT, it typically presents with mucocutaneous bleeding, and the patient's history doesn't strongly suggest this [3].

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