INI-CET 2024 Practice Questions

Q: Which of the following is not a complication of hypokalemia?

Cerebral edema. ***Cerebral edema*** - **Cerebral edema** is typically associated with **hyponatremia** (low sodium levels), which causes hypotonicity in the extracellular fluid leading to water shifting into brain cells. - Hypokalemia primarily impacts neuromuscular and cardiac function and does not directly cause brain swelling due to fluid shifts. *Quadriparesis* - **Severe hypokalemia** can lead to **muscle weakness**, which can progress to flaccid paralysis affecting all four limbs (quadriparesis). - This occurs due to alterations in the **resting membrane potential** of muscle cells, making them less excitable. *Ventricular Tachycardia* - Hypokalemia can cause **cardiac arrhythmias**, including **ventricular tachycardia** and **fibrillation**, by prolonging repolarization and increasing myocardial excitability. - It can also lead to characteristic electrocardiogram (ECG) changes such as **flattened T waves**, **ST segment depression**, and prominent **U waves**. *Diabetes insipidus* - **Nephrogenic diabetes insipidus** can be a complication of chronic hypokalemia, where the kidneys become resistant to the effects of **antidiuretic hormone (ADH)**. - This results in the inability to concentrate urine, leading to **polyuria** (excessive urination) and **polydipsia** (excessive thirst).

Q: A patient presents with fever and retro-orbital pain. Which investigation should be conducted next for confirmation of dengue fever?

NS1 antigen test. ***NS1 antigen test*** - The **NS1 antigen test** is highly sensitive and specific for dengue in the **early stages** of infection (typically 0-7 days after symptom onset), which is when a patient with fever and retro-orbital pain would likely present. - It detects a non-structural protein of the dengue virus, indicating **active viral replication**. *Viral culture* - **Viral culture** for dengue is time-consuming and technically demanding, making it impractical for rapid diagnosis in clinical settings, especially when an urgent confirmation is needed for patient management. - It is primarily used for research purposes rather than routine clinical diagnosis [2]. *IgM ELISA* - **IgM ELISA** detects antibodies produced in response to dengue infection, which typically become detectable **5-7 days after symptom onset**. - While useful for confirming dengue in later stages of illness, it may yield a **false negative** result if performed too early in the course of the disease [2]. *PCR* - **PCR (Polymerase Chain Reaction)** detects dengue viral RNA and is highly sensitive and specific in the **early acute phase** of infection (first 5 days) [1]. - However, it is generally more expensive, requires specialized laboratory equipment, and has a longer turnaround time compared to the NS1 antigen test, making NS1 a more accessible initial diagnostic choice.

Q: Which of the following statements about obstructive sleep apnea is false?

Contraction of pharyngeal muscles can worsen obstruction. ***Contraction of pharyngeal muscles can worsen obstruction*** - In **obstructive sleep apnea (OSA)**, the pharyngeal muscles are normally responsible for maintaining airway patency [1]. - A *contraction* of these muscles would *open* the airway, whereas *relaxation* or *loss of tone* leads to collapse and obstruction. *Apnea is associated with high respiratory effort* - During an **apneic episode** in OSA, the airway is *obstructed*, leading to continued but **unsuccessful inspiratory efforts** against a closed airway. - This results in a significant increase in **respiratory effort** as the diaphragm and accessory muscles try to overcome the obstruction. *Apnea is associated with fall in SpO2* - The cessation of airflow during **apnea** prevents **gas exchange**, leading to a progressive decrease in **oxygen saturation (SpO2)**. - This **hypoxia** is a hallmark physiological consequence of apneic events and often triggers arousal from sleep [2]. *Apnea is associated with sudden awakening* - The combination of **hypoxia** and **hypercapnia** (increased CO2), along with the increased respiratory effort, stimulates the central nervous system [2]. - This stimulation causes a **brief arousal or awakening** from sleep, often accompanied by gasping or snorting, to re-establish airway patency.

Q: Which of the following organisms show parthenogenesis?

Strongyloides. ***Correct: Strongyloides*** - *Strongyloides stercoralis* is known for its complex life cycle, which includes **parthenogenetic reproduction** in the free-living female generation. - The parasitic females can produce larvae directly through **parthenogenesis (reproduction without fertilization)**, enabling autoinfection. - This unique ability allows the parasite to **reproduce without a male** within and outside the human host, leading to persistent infections and hyperinfection syndrome. *Incorrect: Ascaris* - *Ascaris lumbricoides* reproduces sexually, requiring **both male and female worms** for fertilization and egg production. - There is no evidence of parthenogenetic reproduction in *Ascaris*. *Incorrect: Trichuris* - *Trichuris trichiura* (whipworm) is a **dioecious** (sexually reproducing) nematode where **separate male and female worms** are required for reproduction. - Parthenogenesis is not observed in the life cycle of *Trichuris*. *Incorrect: Ancylostoma* - *Ancylostoma duodenale* (hookworm) reproduces sexually in the human intestine. - Requires **male and female worms** to produce fertilized eggs; parthenogenesis does not occur.

Q: A lady came with yellowish discharge and stain showing gram-negative diplococci. What is the most likely causative organism of her condition?

Neisseria gonorrhoeae. ***Neisseria gonorrhoeae*** - The presence of **yellowish discharge** and **gram-negative diplococci** on a stain is a classic presentation for **gonorrhea**, caused by *Neisseria gonorrhoeae*. - This bacterium is a common cause of **sexually transmitted infections (STIs)**, leading to conditions like cervicitis, urethritis, and pelvic inflammatory disease. *Streptococcus pneumoniae* - This organism is a **gram-positive coccus** and typically causes **respiratory infections** (e.g., pneumonia, otitis media, meningitis), not genital discharge with gram-negative diplococci. - It is not associated with STI-related yellowish genital discharge. *Enterococcus faecalis* - This is a **gram-positive coccus** and a common cause of **urinary tract infections (UTIs)** and **nosocomial infections**, but not typically associated with yellowish genital discharge showing gram-negative diplococci. - It is also not classified as a gram-negative organism. *Both Streptococcus and Enterococcus* - This option is incorrect because both *Streptococcus* and *Enterococcus* are **gram-positive organisms**. - The clinical presentation clearly describes **gram-negative diplococci**, which rules out these bacteria as the primary cause.

Q: Which of the following organisms does not have a polysaccharide capsule?

Hepatitis B. ***Hepatitis B (Correct Answer)*** - Hepatitis B is a **DNA virus** (Hepadnavirus family), not a bacterium - Viruses do **not possess polysaccharide capsules** - Its outer envelope is composed of **lipids and proteins** (HBsAg surface antigen), not polysaccharides - This is the only non-bacterial organism in the options, making it the correct answer *Haemophilus influenzae type b (Hib)* - Encapsulated bacterium with a **polysaccharide capsule** composed of **polyribosylribitol phosphate (PRP)** - The PRP capsule is a major virulence factor protecting against phagocytosis - Causes invasive diseases like meningitis, epiglottitis, and septicemia - Hib conjugate vaccine targets this capsular polysaccharide *Streptococcus pneumoniae (Pneumococcus)* - Possesses a prominent **polysaccharide capsule** (over 90 serotypes based on capsular composition) - The capsule is the primary virulence factor enabling immune evasion - Inhibits complement activation and prevents phagocytosis - Pneumococcal vaccines (PCV13, PPSV23) target capsular polysaccharides *Neisseria meningitidis* - Encapsulated gram-negative diplococcus with a **polysaccharide capsule** - Capsule is essential for virulence and survival in bloodstream - Serogroups (A, B, C, W, Y) are based on capsular polysaccharide composition - Meningococcal conjugate vaccines target capsular antigens (except serogroup B which uses protein-based vaccine)

Q: 18 weeks pregnant female presents with no high risk of NTD and low risk of trisomy 21 on quad test. What is the most appropriate next step in management?

Perform a detailed fetal ultrasound.. ***Perform a detailed fetal ultrasound.*** - A **detailed fetal ultrasound** (often referred to as an **anatomy scan**) at around 18-22 weeks is a standard component of prenatal care for all pregnant women, regardless of screening test results. - This ultrasound evaluates fetal anatomy for structural anomalies, assesses fetal growth, and confirms gestational age, providing crucial information even with low-risk screening. *Repeat non-invasive screening test.* - Repeating a non-invasive screening test (like another quad screen or NIPT) is generally **not indicated** when initial results show a low risk and there are no other clinical concerns. - Such tests are primarily for screening purposes, and a second low-risk result would offer little additional actionable information, as their positive predictive value is low. *Perform invasive diagnostic testing.* - **Invasive diagnostic testing**, such as **amniocentesis** or **chorionic villus sampling (CVS)**, carries a risk of miscarriage and is reserved for situations with a high risk of chromosomal abnormalities or genetic conditions. - Given the low-risk quad screen results for trisomy 21 and no high risk for NTDs, invasive testing is **not warranted** at this stage. *Perform amniotic fluid analysis.* - **Amniotic fluid analysis** is part of an amniocentesis, an **invasive diagnostic procedure** designed to detect chromosomal abnormalities or genetic disorders. - This procedure is typically reserved for cases where screening tests indicate a high risk or there is a clinical suspicion of a genetic condition; it's **not a routine step** after a low-risk quad screen.

Q: A child presents with short stature. His bone age is less than chronological age. The height of his parents is normal. What is the most likely diagnosis?

Constitutional short stature. ***Constitutional short stature*** - This condition is characterized by a **delayed bone age** compared to chronological age, indicating a delay in skeletal maturation. - Children with constitutional short stature typically have **normal parental height** and will eventually reach a normal adult height, although puberty and growth spurts are often delayed. *Malnutrition* - While malnutrition causes **short stature** and **delayed bone age**, it would also likely present with other signs of nutritional deficiency such as **weight loss** or failure to thrive. - The case does not mention any dietary issues or poor socioeconomic conditions typically associated with malnutrition. *Familial short stature* - In familial short stature, the child's height is typically proportional to the parents' height, indicating a strong genetic component to their shorter stature. - It is characterized by a **normal bone age** for chronological age, unlike the delayed bone age seen in this child. *Cretinism* - Cretinism, or congenital hypothyroidism, results in **severe growth retardation** and **delayed bone age**. - However, it is also associated with distinct features like **coarse facial features**, macroglossia, umbilical hernia, and severe developmental delays, which are not mentioned in this case.

Q: Which of the following statements regarding Wilms tumor is false?

Lung metastasis is rare and occurs late. ***Lung metastasis is rare and occurs late*** - This statement is **false** primarily because when lung metastases occur, they often present **early (at initial diagnosis)** rather than late. - Approximately **10-15% of patients** have pulmonary metastases at presentation, making the "occurs late" portion incorrect. - While lungs are the **most common site** for distant metastases when they do occur, the overall incidence is relatively low, so calling it "rare" is debatable but the "late" timing is definitively wrong. - The statement's claim about late occurrence contradicts clinical reality where metastatic disease, when present, is typically identified at diagnosis or within the first 2 years. *Most commonly seen < 5 years of age* - This statement is **true** as Wilms tumor has **peak incidence at ages 2-3 years**, with the majority of cases diagnosed before age **5 years**. - It is the most common primary **renal malignancy in children**, predominantly affecting young children. *Most patients recover well with chemotherapy and radiotherapy.* - This statement is **true** as Wilms tumor has an **excellent prognosis** with **overall survival rates exceeding 90%** using multimodal therapy. - Treatment includes **surgery (nephrectomy), chemotherapy**, and **radiotherapy** (in selected cases), resulting in high cure rates even in advanced stages. *Presents as a renal mass.* - This statement is **true** as the typical presentation is an **asymptomatic abdominal mass** discovered incidentally by parents or during routine examination. - The mass is usually **firm, smooth, and non-tender**, representing an **intrarenal tumor** that may cause abdominal distension.

Question 1

Which of the following is not a complication of hypokalemia?

Accepted Answer

Cerebral edema

Answer

Quadriparesis

Answer

Ventricular Tachycardia

Answer

Diabetes insipidus

Question 2

A patient presents with fever and retro-orbital pain. Which investigation should be conducted next for confirmation of dengue fever?

Accepted Answer

NS1 antigen test

Answer

Viral culture

Answer

IgM ELISA

Answer

PCR

Question 3

Which of the following statements about obstructive sleep apnea is false?

Accepted Answer

Contraction of pharyngeal muscles can worsen obstruction

Answer

Apnea is associated with high respiratory effort

Answer

Apnea is associated with fall in SpO2

Answer

Apnea is associated with sudden awakening

Question 4

Which of the following organisms show parthenogenesis?

Accepted Answer

Strongyloides

Answer

Ascaris

Answer

Trichuris

Answer

Ancylostoma

Question 5

A lady came with yellowish discharge and stain showing gram-negative diplococci. What is the most likely causative organism of her condition?

Accepted Answer

Neisseria gonorrhoeae

Answer

Streptococcus pneumoniae

Answer

Enterococcus faecalis

Answer

Both Streptococcus and Enterococcus

Question 6

Assertion: Plasmodium falciparum does not show the schizont stage in the peripheral blood. Reason: This is due to cytoadherence of infected RBCs to the vascular endothelium.

Accepted Answer

Assertion is true, reason is true and reason is the correct explanation of the assertion.

Answer

Assertion is true, reason is true but reason is not the correct explanation of the assertion.

Answer

Assertion is true, reason is false.

Answer

Assertion is false, reason is true.

Question 7

Which of the following organisms does not have a polysaccharide capsule?

Accepted Answer

Hepatitis B

Answer

Haemophilus influenzae type b (Hib)

Answer

Streptococcus pneumoniae (Pneumococcus)

Answer

Neisseria meningitidis

Question 8

18 weeks pregnant female presents with no high risk of NTD and low risk of trisomy 21 on quad test. What is the most appropriate next step in management?

Accepted Answer

Perform a detailed fetal ultrasound.

Answer

Repeat non-invasive screening test.

Answer

Perform invasive diagnostic testing.

Answer

Perform amniotic fluid analysis.

Question 9

A child presents with short stature. His bone age is less than chronological age. The height of his parents is normal. What is the most likely diagnosis?

Accepted Answer

Constitutional short stature

Answer

Malnutrition

Answer

Familial short stature

Answer

Cretinism

Question 10

Which of the following statements regarding Wilms tumor is false?

Accepted Answer

Lung metastasis is rare and occurs late

Answer

Most commonly seen < 5 years of age

Answer

Most patients recover well with chemotherapy and radiotherapy.

Answer

Presents as a renal mass.

INI-CET 2024

Internal Medicine

Microbiology

Obstetrics and Gynecology

Pediatrics