INI-CET 2024 Practice Questions

Q: The bone matrix has the following crystals -

Calcium hydroxyapatite. ***Calcium hydroxyapatite*** - The primary mineral component of bone matrix is **calcium hydroxyapatite**, which gives bone its rigidity and strength [1]. - These crystals are formed from **calcium and phosphate ions** arranged in a specific crystalline structure within the collagen fibers [1]. *Calcium pyrophosphate* - **Calcium pyrophosphate dihydrate (CPPD)** crystals are associated with **pseudogout**, a condition causing joint inflammation, not the normal bone matrix [1]. - They are found in articular cartilage and synovial fluid, not as a structural component of healthy bone. *Calcium phosphate* - While hydroxyapatite is a form of **calcium phosphate**, simply "calcium phosphate" is too general and does not specify the exact crystalline structure found in bone [1]. - Many calcium phosphate compounds exist, but **hydroxyapatite** is the specific and most abundant one in bone [1]. *Calcium sulphate* - **Calcium sulfate** is not a naturally occurring mineral component of the bone matrix in vertebrates. - It is sometimes used in medical applications as a **bone graft substitute** or a drug delivery system, but not as an endogenous component.

Q: A 45-year-old Caucasian male with a history of chronic myeloid leukemia for which he is receiving chemotherapy presents to the emergency room with oliguria and colicky left flank pain. His serum creatinine is 3.0 mg/dL and his urine pH is 5.0. You diagnose nephrolithiasis. His kidney stones, however, are not visible on abdominal x-ray. His stone is most likely composed of which of the following?

Uric acid. ***Uric acid*** - The patient has **chronic myeloid leukemia (CML)** and is receiving **chemotherapy**, which can cause a rapid turnover of cells, leading to **hyperuricemia** and the formation of uric acid stones. - Uric acid stones are **radiolucent** (not visible on X-ray) and are associated with a **low urine pH** (5.0 in this case). *Cystine* - Cystine stones are caused by a **genetic defect** in amino acid transport, leading to high urinary cystine levels. - While they are also **radiolucent**, there is no clinical information to suggest a genetic predisposition for cystinuria in this patient. *Calcium phosphate* - Calcium phosphate stones are typically **radio-opaque** and usually form in alkaline urine, which contradicts the patient's low urine pH [1]. - They are often associated with conditions like **renal tubular acidosis** or hyperparathyroidism [1]. *Magnesium ammonium phosphate* - These are also known as **struvite stones** and are highly suggestive of **urinary tract infections** with urea-splitting organisms (e.g., *Proteus*) [1]. - They tend to grow large, form **staghorn calculi**, and are **radio-opaque** [1]. *Calcium oxalate* - Calcium oxalate stones are the **most common type** of kidney stone and are **radio-opaque**, making them visible on X-ray. - They are typically associated with conditions causing **hypercalciuria** or hyperoxaluria, which are not explicitly indicated here, and they would be visible on the X-ray.

Q: To replenish the inventory, blood banks routinely issue blood packets which are close to the expiry date. Which of the following will be the closest to expiry date, according to the anticoagulant used and the method of storage of the packet:

SAGM, 25 days with irradiation. ***SAGM, 25 days with irradiation*** - **SAGM** (Saline-Adenine-Glucose-Mannitol) is an additive solution that extends the storage life of red blood cells significantly. - While SAGM usually allows for storage up to **42 days**, if the blood is **irradiated**, the shelf life is reduced to **28 days from collection or 14 days from irradiation, whichever is sooner**. Given the options, 25 days with irradiation falls within this reduced shelf life, making it the closest to expiry among the provided choices (implying the Irradiation was done earlier). *ACD, 14 days* - **ACD** (Acid Citrate Dextrose) is an older anticoagulant primarily used for apheresis products. - Red blood cells collected with ACD typically have a maximum storage duration of **21 days**. While 14 days is within this, other anticoagulant-additive combinations offer longer storage, and this option is not the closest to expiry when considering the maximum allowed. *CPDA, 27 days* - **CPDA** (Citrate Phosphate Dextrose Adenine) provides a standard shelf life of **35 days** for red blood cells. - While 27 days represents blood that has been stored for a significant period, it still has 8 more days until its maximum expiry, making it less "close to expiry" than the irradiated SAGM option which would expire sooner. *SAGM, 35 days* - **SAGM** (Saline-Adenine-Glucose-Mannitol) allows for the storage of red blood cells for up to **42 days** from collection. - At 35 days, a unit stored in SAGM still has 7 days until its maximum expiry date (if not irradiated), making it less "close to expiry" than a unit that had been irradiated.

Q: Arrange the following according to good outcome a - zone of stasis b - zone of coagulation c - zone of hyperemia

c > a > b. **Context:** This question refers to Jackson's burn wound model, which describes three concentric zones in a burn injury. ***c > a > b*** (Correct Answer) - The **zone of hyperemia (c)** has the **best prognosis** for recovery because tissue damage is minimal, involving primarily vasodilation and increased blood flow. This zone typically recovers completely within 7-10 days. - The **zone of stasis (a)** has an **intermediate prognosis**; tissue here is potentially salvageable but at risk of progression to necrosis within 24-48 hours if not properly managed (adequate fluid resuscitation, prevention of infection, avoiding vasoconstrictors). - The **zone of coagulation (b)** has the **worst prognosis**, as cellular damage is irreversible with immediate coagulative necrosis. This tissue will eventually slough off and requires debridement. *a > b > c* - Incorrectly suggests the **zone of stasis** has better outcome than **zone of hyperemia**, which contradicts the pathophysiology of burn injuries. - The **zone of coagulation** cannot have better outcome than **zone of hyperemia** as it represents dead tissue. *a > c > b* - Incorrectly places **zone of stasis** as having the best outcome when it has only intermediate prognosis. - The **zone of hyperemia** should be first as it has the highest probability of complete recovery without intervention. *a = c > b* - Incorrectly equates the prognosis of **zone of stasis** and **zone of hyperemia**, despite clear differences in severity and reversibility of tissue damage. - The **zone of hyperemia** has unequivocally better prognosis than the **zone of stasis**.

Question 1

The bone matrix has the following crystals -

Accepted Answer

Calcium hydroxyapatite

Answer

Calcium pyrophosphate

Answer

Calcium phosphate

Answer

Calcium sulphate

Question 2

A 45-year-old Caucasian male with a history of chronic myeloid leukemia for which he is receiving chemotherapy presents to the emergency room with oliguria and colicky left flank pain. His serum creatinine is 3.0 mg/dL and his urine pH is 5.0. You diagnose nephrolithiasis. His kidney stones, however, are not visible on abdominal x-ray. His stone is most likely composed of which of the following?

Accepted Answer

Uric acid

Answer

Cystine

Answer

Calcium phosphate

Answer

Magnesium ammonium phosphate

Answer

Calcium oxalate

Question 3

To replenish the inventory, blood banks routinely issue blood packets which are close to the expiry date. Which of the following will be the closest to expiry date, according to the anticoagulant used and the method of storage of the packet:

Accepted Answer

SAGM, 25 days with irradiation

Answer

ACD, 14 days

Answer

CPDA, 27 days

Answer

SAGM, 35 days

Question 4

A 12-year-old Caucasian male presents with his mother to the pediatrician’s office complaining of right thigh pain. He reports that he has noticed slowly progressive pain and swelling over the distal aspect of his right thigh over the past two months. He denies any recent trauma to the area and his temperature is 100.9°F (38.3°C). On exam, there is swelling and tenderness overlying the distal right femoral diaphysis. Laboratory evaluation is notable for an elevated white blood cell (WBC) count and elevated erythrocyte sedimentation rate (ESR). A radiograph of the patient’s right leg is shown. Biopsy of the lesion demonstrates sheets of monotonous small round blue cells with minimal cytoplasm. Which of the following genetic mutations is most likely associated with this patient’s condition?

Accepted Answer

t(11;22)

Answer

RB1 inactivation

Answer

TP53 inactivation

Answer

t(8;14)

Answer

t(X;18)

Question 5

Arrange the following according to good outcome
a - zone of stasis
 b - zone of coagulation
 c - zone of hyperemia

Accepted Answer

c > a > b

Answer

a > b > c

Answer

a > c > b

Answer

a = c > b

INI-CET 2024

Anatomy

Internal Medicine

Pathology

Surgery