INI-CET 2021 Practice Questions

Q: A 45-year-old male patient presented with a history of bilateral lower limb weakness, which progressed to his upper limbs in a year. On examination, he had weakness in both lower limbs and wasting in the left upper limb. Babinski sign was positive and the deep tendon reflexes were hyperactive. He has no sensory loss or any autonomic dysfunction. What is the likely diagnosis?

ALS. ***ALS*** - This patient exhibits a classic combination of **upper motor neuron (UMN)** signs (hyperactive deep tendon reflexes, positive Babinski sign) and **lower motor neuron (LMN)** signs (weakness, wasting), along with progressive limb weakness [1], [2]. These findings are characteristic of **amyotrophic lateral sclerosis (ALS)**, especially with the sparing of sensory and autonomic function [1]. - ALS is fundamentally a **motor neuron disease** that affects both UMNs and LMNs, leading to progressive muscle weakness without significant sensory deficits [1]. *GBS* - **Guillain-Barré Syndrome (GBS)** typically presents with **acute, ascending paralysis** and **areflexia** or hyporeflexia, which contradicts the hyperactive reflexes and progressive, chronic nature observed in the patient. - While GBS causes motor weakness, it is primarily a demyelinating neuropathy affecting the peripheral nervous system and usually spares upper motor neuron signs. *MS* - **Multiple sclerosis (MS)** is characterized by **demyelinating lesions** in the central nervous system, leading to a wide variety of neurological deficits, often with sensory disturbances, visual problems, and bladder dysfunction. - While MS can cause motor weakness and hyperreflexia, it usually presents with a relapsing-remitting course and significant sensory symptoms, which are absent in this patient. *Tropical spastic paraparesis* - **Tropical spastic paraparesis** primarily causes **progressive spasticity and weakness** in the lower limbs, indicative of central nervous system involvement, often linked to **HTLV-1 infection**. - While it features upper motor neuron signs, it typically does not involve the prominent muscle wasting and lower motor neuron signs observed in this patient.

Q: A 62-year-old male patient with heart failure is scheduled for a heart transplant. His renal function test is deranged, and haemoglobin is $6 \mathrm{gm} \%$. The physician ordered 2 units of whole blood. Four hours after transfusion, he developed severe respiratory distress. On examination, he is hypoxemic, has tachycardia and his mean arterial pressure is elevated. Which of the following are the best investigations for the above scenario? 1. Chest X-ray 2. Brain natriuretic peptide (BNP) level 3. Absolute neutrophil count 4. Leucocyte antibodies 5. Platelets

1 and 2. ***1 and 2*** - A **Chest X-ray** would help identify signs of **pulmonary edema** and **cardiomegaly** [1], which are characteristic of transfusion-associated circulatory overload (**TACO**) due to his underlying heart failure exacerbated by fluid from the transfusion. [2] - An elevated **Brain Natriuretic Peptide (BNP) level** is a key biomarker for heart failure [1] and would support a diagnosis of **TACO** by indicating increased ventricular stretch and volume overload. *3 and 5* - An **absolute neutrophil count** is primarily relevant for assessing infection or inflammatory conditions, which are not the primary focus given the acute respiratory distress post-transfusion in a heart failure patient. - **Platelets** are important for coagulation assessments but do not directly explain acute respiratory distress and hypoxemia in the context of post-transfusion events like TACO. *4 and 5* - **Leukocyte antibodies** (such as anti-HLA antibodies) are typically investigated in cases of **transfusion-related acute lung injury (TRALI)**, but the elevated blood pressure and underlying heart failure point more strongly towards **TACO**. - **Platelets** are not a primary investigation for acute respiratory distress following transfusion in a patient with heart failure. *2 only* - While an elevated **BNP level** is highly indicative of heart failure exacerbation and TACO [1], a **Chest X-ray** is also crucial for visualizing the pulmonary edema and assessing the extent of circulatory overload [2]. - Relying solely on BNP might miss co-occurring pulmonary issues or provide an incomplete picture of the patient's acute respiratory distress.

Q: The following set of instruments are used for which procedure?

Pap smear. ***Pap smear*** - The image displays a complete set of instruments used for a **Pap smear**, including **glass slides** for sample collection, a **cervical brush**, a **spatula** (cytobrush and Ayre spatula), and a **speculum** to visualize the cervix. - These tools are specifically designed for collecting cervical cells to screen for **cervical cancer** and **precancerous changes**. *Biopsy* - A biopsy typically involves specialized instruments like **punch biopsy tools**, **forceps**, or needles to extract tissue samples, which are not depicted here. - While glass slides might be used for processing biopsy samples, the primary collection tools are absent. *Dilatation and curettage* - This procedure requires instruments such as **dilators** to open the cervix and **curetters** to scrape the uterine lining, which are not shown in the image. - The instruments shown are for surface cell collection, not for uterine cavity procedures. *Hysteroscopy* - Hysteroscopy uses a **hysteroscope**—a thin, lighted tube with a camera—to visualize the inside of the uterus. - The instruments in the image are for external examination and cervical cell collection, not for direct visualization of the uterine cavity.

Q: Which of the following is not a long-acting reversible contraceptive method?

Combined oral contraceptives. ***Combined oral contraceptives*** - While effective, **combined oral contraceptives** require daily adherence and are not typically classified as long-acting due to their need for frequent, consistent administration. - Their mechanism involves **exogenous hormones** that suppress ovulation and thicken cervical mucus, but their contraceptive effect relies on continuous daily intake. *Implanon* - **Implanon** (etonogestrel implant) is a **subdermal contraceptive implant** that provides effective contraception for up to three years. - It works by slowly releasing progestin, making it a **long-acting reversible contraceptive (LARC)**. *Copper T* - The **Copper T intrauterine device (IUD)** is a non-hormonal LARC that can prevent pregnancy for **up to 10 years**. - It acts by creating an inflammatory reaction in the uterus that is toxic to sperm and eggs, preventing fertilization. *Depo-Provera injection* - The **Depo-Provera injection** (medroxyprogesterone acetate) is a progestin-only contraceptive given every **3 months**. - While it offers extended protection, it is **not universally classified as a LARC** by major guidelines (WHO, ACOG, CDC), which typically reserve this designation for IUDs and implants that do not require regular clinic visits.

Q: A patient is on phenytoin for a seizure disorder. He was prescribed sucralfate 4 times a day for peptic ulcers. What should be the minimum duration of time between consumption of these drugs?

120 minutes. **_120 minutes_** - **Sucralfate** forms a protective barrier in the stomach and can **adsorb other medications**, significantly reducing their absorption. - A minimum separation of **2 hours (120 minutes)** is recommended between sucralfate and other oral medications to prevent drug interactions. *90 minutes* - While a longer interval is beneficial, **90 minutes** may not be sufficient to completely avoid the significant reduction in **phenytoin absorption** caused by sucralfate. - Given the narrow therapeutic index of phenytoin, a more conservative approach with a longer separation is preferred. *60 minutes* - A **60-minute interval** is generally considered too short to prevent the **adsorption of phenytoin** by sucralfate. - This short duration increases the risk of **subtherapeutic phenytoin levels** and potential seizure recurrence. *30 minutes* - A **30-minute interval** is entirely inadequate and would almost certainly lead to a significant **reduction in phenytoin absorption**. - This would place the patient at high risk of **seizure recurrence** due to insufficient drug levels.

Q: What is the mechanism of action of cyclosporine?

Inhibition of calcineurin. ***Inhibition of calcineurin*** - Cyclosporine forms a complex with **cyclophilin**, which then inhibits the phosphatase activity of **calcineurin**. - This inhibition prevents the dephosphorylation and subsequent nuclear translocation of **NFAT (nuclear factor of activated T-cells)**, thereby blocking the transcription of **IL-2** and other cytokines essential for T-cell activation. *Dihydro-orotate dehydrogenase inhibition* - This is the mechanism of action of **leflunomide**, another immunosuppressant, which works by inhibiting *de novo* pyrimidine synthesis. - Leflunomide primarily affects rapidly proliferating cells, such as T-lymphocytes, by depriving them of essential pyrimidine nucleotides. *AMP kinase stimulation* - **AMP-activated protein kinase (AMPK)** is a cellular energy sensor that plays a role in metabolism and cellular growth. - While AMPK activation has various cellular effects, it is not the primary mechanism of action for cyclosporine or other calcineurin inhibitors. *IMP dehydrogenase inhibition* - This is the mechanism of action of **mycophenolate mofetil**, an immunosuppressant that selectively inhibits *de novo* guanosine nucleotide synthesis. - By depleting guanosine nucleotides, mycophenolate specifically inhibits the proliferation of T and B lymphocytes.

Q: Identify the pathology from the given flow-volume loop:

Fixed central airway obstruction. ***Fixed central airway obstruction*** - This flow-volume loop shows **flattening of both the inspiratory and expiratory limbs**, creating a characteristic "box" or "square" shape. - This pattern indicates that airflow is limited equally during both inspiration and expiration, regardless of lung volume changes, which is characteristic of a **fixed central airway obstruction**. - Examples include **tracheal stenosis, tracheal tumors, or fixed goiters** compressing the trachea. *Variable extrathoracic obstruction* - Characterized by flattening of the **inspiratory limb only**, as negative intrathoracic pressure during inspiration exacerbates the obstruction. - The expiratory limb typically remains normal as positive intrathoracic pressure tends to open the airway. - Examples include **vocal cord paralysis or extrathoracic tracheal tumors**. *Variable intrathoracic obstruction* - Characterized by flattening of the **expiratory limb only**, as positive intrathoracic pressure during forced expiration collapses the airway. - The inspiratory limb usually remains normal as negative pressure helps maintain airway patency. - Examples include **intrathoracic tracheal tumors or tracheomalacia**. *Fixed distal airway obstruction* - Fixed obstructions producing the characteristic "box" pattern are typically **central (proximal) lesions in large airways**, not distal. - Distal airway obstructions (like **COPD or asthma**) produce a different flow-volume loop pattern characterized by **decreased peak expiratory flow** and "scooping" or "concave" appearance of the expiratory limb, not the flat bilateral pattern seen here.

Q: Acid-base imbalance is suspected in a patient. Which of the following parameters would you use for initial determination of acid-base status?

pH, PaCO2, and Bicarbonate. ***pH, PaCO2, and Bicarbonate*** - The **pH** provides immediate assessment of overall acid-base status (acidemia if 7.45) - The **PaCO2** reflects the respiratory component - elevated in respiratory acidosis or compensated metabolic alkalosis; decreased in respiratory alkalosis or compensated metabolic acidosis - The **HCO3- (bicarbonate)** reflects the metabolic component - essential for determining whether the primary disorder is metabolic or respiratory - This triad forms the **standard approach** to arterial blood gas (ABG) interpretation taught in all major medical textbooks - Together, these three parameters allow complete initial classification of acid-base disorders using the Henderson-Hasselbalch relationship *pH and PaCO2* - While pH and PaCO2 are critical measurements, **without bicarbonate**, you cannot differentiate between metabolic and respiratory disorders or assess metabolic compensation - For example, a low pH with normal PaCO2 could indicate metabolic acidosis, but you need HCO3- to confirm this diagnosis - Incomplete for initial acid-base determination *pH, PaCO2, and Base excess* - Base excess is a **calculated parameter** used to quantify the metabolic component of acid-base disturbances - While useful, it is considered a **secondary parameter** for more detailed metabolic analysis rather than essential for initial determination - Standard ABG interpretation uses bicarbonate, not base excess, as the primary metabolic parameter *pH, PaCO2, Bicarbonate, and Base excess* - While this includes all relevant parameters, **base excess is redundant** for initial determination - Base excess adds quantitative information about metabolic component but is not required for the initial classification of acid-base status - The essential triad for initial assessment is pH, PaCO2, and HCO3-

Q: Which of the following is not an off-label use of risperidone?

Bipolar disorder. ***Bipolar disorder*** - **Risperidone** is FDA-approved for the treatment of **bipolar I disorder**, both as monotherapy and adjunctive therapy for acute manic or mixed episodes. - This means its use for bipolar disorder is an **on-label indication**, not an off-label use. *PTSD* - The use of risperidone for **post-traumatic stress disorder (PTSD)** is considered an **off-label use**, as it is not specifically approved by the FDA for this condition. - While atypical antipsychotics may be used in some cases for severe PTSD symptoms, especially those involving psychosis or severe agitation, it is not a primary or approved treatment. *OCD* - The use of risperidone as an adjunct in **obsessive-compulsive disorder (OCD)**, particularly in treatment-resistant cases, is an **off-label use**. - While some studies support its use for augmenting SSRIs in OCD, it is not an FDA-approved indication. *Dementia* - Using risperidone for behavioral symptoms associated with **dementia** (e.g., aggression, agitation) is generally considered an **off-label use**. - Although it may be prescribed for these symptoms, there are significant concerns regarding increased mortality risk in elderly patients with dementia-related psychosis, leading to specific warnings and limited official indications.

Question 1

Identify the false statement regarding suicide inhibition

Accepted Answer

The inhibitor can bind with any site resulting in suicidal inhibition

Answer

The binding of the enzyme to the substrate analogue is irreversible

Answer

The inhibitor forms a product with the enzyme and the product inhibits it

Answer

They are enzyme specific and used in rational drug design

Question 2

A 45-year-old male patient presented with a history of bilateral lower limb weakness, which progressed to his upper limbs in a year. On examination, he had weakness in both lower limbs and wasting in the left upper limb. Babinski sign was positive and the deep tendon reflexes were hyperactive. He has no sensory loss or any autonomic dysfunction. What is the likely diagnosis?

Accepted Answer

ALS

Answer

GBS

Answer

MS

Answer

Tropical spastic paraparesis

Question 3

A 62-year-old male patient with heart failure is scheduled for a heart transplant. His renal function test is deranged, and haemoglobin is $6 \mathrm{gm} \%$. The physician ordered 2 units of whole blood. Four hours after transfusion, he developed severe respiratory distress. On examination, he is hypoxemic, has tachycardia and his mean arterial pressure is elevated. Which of the following are the best investigations for the above scenario?

1. Chest X-ray
2. Brain natriuretic peptide (BNP) level
3. Absolute neutrophil count
4. Leucocyte antibodies
5. Platelets

Accepted Answer

1 and 2

Answer

3 and 5

Answer

4 and 5

Answer

2 only

Question 4

The following set of instruments are used for which procedure?

Accepted Answer

Pap smear

Answer

Biopsy

Answer

Dilatation and curettage

Answer

Hysteroscopy

Question 5

Which of the following is not a long-acting reversible contraceptive method?

Accepted Answer

Combined oral contraceptives

Answer

Implanon

Answer

Copper T

Answer

Depo-Provera injection

Question 6

A patient is on phenytoin for a seizure disorder. He was prescribed sucralfate 4 times a day for peptic ulcers. What should be the minimum duration of time between consumption of these drugs?

Accepted Answer

120 minutes

Answer

90 minutes

Answer

60 minutes

Answer

30 minutes

Question 7

What is the mechanism of action of cyclosporine?

Accepted Answer

Inhibition of calcineurin

Answer

Dihydro-orotate dehydrogenase inhibition

Answer

AMP kinase stimulation

Answer

IMP dehydrogenase inhibition

Question 8

Identify the pathology from the given flow-volume loop:

Accepted Answer

Fixed central airway obstruction

Answer

Variable extra thoracic obstruction

Answer

Variable intrathoracic obstruction

Answer

Fixed distal airway obstruction

Question 9

Acid-base imbalance is suspected in a patient. Which of the following parameters would you use for initial determination of acid-base status?

Accepted Answer

pH, PaCO2, and Bicarbonate

Answer

pH, PaCO2, and Base excess

Answer

pH and PaCO2

Answer

pH, PaCO2, Bicarbonate, and Base excess

Question 10

Which of the following is not an off-label use of risperidone?

Accepted Answer

Bipolar disorder

Answer

PTSD

Answer

OCD

Answer

Dementia

INI-CET 2021

Biochemistry

Internal Medicine

Obstetrics and Gynecology

Pharmacology

Physiology

Psychiatry