NEET-PG 2018 Practice Questions

Q: Which chromosome is responsible for the production of MIF?

Chromosome 22. ***Chromosome 22*** * The **macrophage migration inhibitory factor (MIF)** gene is located on **chromosome 22q11.2**, making it responsible for MIF production. * MIF is a crucial **pro-inflammatory cytokine** involved in immune responses and inflammation. *Chromosome 16* * Chromosome 16 contains genes like those for **alpha-globin** and **CDH1 (E-cadherin)**, not MIF. * Disorders associated with chromosome 16 include **alpha-thalassemia** and certain types of **hereditary diffuse gastric cancer**. *X Chromosome* * The X chromosome contains genes primarily involved in **sex determination** and various X-linked disorders. * Examples include genes like **DMD (Duchenne muscular dystrophy)** and **F8 (hemophilia A)**, but not MIF. *Y chromosome* * The Y chromosome contains genes, such as **SRY (sex-determining region Y)**, that are critical for male sexual development. * It plays a role in male-specific traits and conditions like **infertility** but does not carry the gene for MIF.

Q: Which of the following is an example of an X-linked disorder?

Color blindness. ***Color blindness*** - **Color blindness**, particularly red-green color blindness, is a classic example of an **X-linked recessive disorder**. - It results from mutations in genes encoding **photopigments** located on the X chromosome, affecting more males than females. - Represents one of the most commonly cited examples of X-linked inheritance in medical education. *Thalassemia* - **Thalassemia** is an **autosomal recessive disorder** affecting the synthesis of hemoglobin chains (α or β chains). - Not an X-linked condition; mutations are in genes on chromosome 16 (α-thalassemia) or chromosome 11 (β-thalassemia). - Commonly seen in populations from the Mediterranean, Middle East, and Asia. *Azoospermia* - **Azoospermia** (absence of sperm in ejaculate) is a clinical finding, not a specific genetic disorder. - Can result from various genetic causes including **Y-chromosome microdeletions** and **autosomal mutations** (e.g., CFTR gene in congenital bilateral absence of vas deferens). - Not classified as an X-linked disorder. *Sickle cell anemia* - **Sickle cell anemia** is an **autosomal recessive disorder** caused by a mutation in the β-globin gene on chromosome 11. - Results from substitution of valine for glutamic acid at position 6 of the β-globin chain (HbS). - Not an X-linked condition; both males and females are equally affected when inheriting two copies of the mutant allele.

Q: Patient presenting with cutaneous vasculitis, glomerulonephritis, peripheral neuropathy, Which investigation is to be performed next that will help you diagnose the condition?

ANCA. ### ANCA - The combination of **cutaneous vasculitis**, **glomerulonephritis**, and **peripheral neuropathy** points towards a small-vessel vasculitis, for which **ANCA (anti-neutrophil cytoplasmic antibodies)** testing is crucial [1]. - ANCA is highly specific for conditions like **Granulomatosis with Polyangiitis (GPA)** and **Microscopic Polyangiitis (MPA)** [1]. ### RA factor - **Rheumatoid factor (RF)** is primarily associated with **rheumatoid arthritis**, which typically presents with symmetrical polyarthritis, not the constellation of symptoms described. - While RF can be positive in some vasculitides, it is not the most specific initial test for the given clinical presentation. ### Hbsag - **Hepatitis B surface antigen (HbsAg)** typically screens for **Hepatitis B infection**, which can cause **polyarteritis nodosa (PAN)**, a medium-vessel vasculitis. - However, the patient's symptoms (cutaneous vasculitis, glomerulonephritis) are more characteristic of **small-vessel vasculitis**, making ANCA a more direct investigation [1]. ### MIF - **MIF (Macrophage Migration Inhibitory Factor)** is a cytokine involved in inflammation, but it is not a routine diagnostic marker for vasculitis. - It is not used as a primary investigation to diagnose specific autoimmune or inflammatory conditions like vasculitis.

Q: Which of the following organisms is MOST associated with histamine production in scombroid fish poisoning?

Morganella morganii. ***Morganella morganii*** - ***Morganella morganii*** is the **MOST commonly implicated organism** in **scombroid fish poisoning** - It produces the enzyme **histidine decarboxylase**, which converts **histidine** (abundant in scombroid fish like tuna, mackerel, bonito) to **histamine** - When fish are stored at improper temperatures (>15°C), *M. morganii* proliferates and produces large amounts of **histamine** - Other histamine-producing bacteria include *Klebsiella*, *Proteus*, *Enterobacter*, and *Photobacterium* species - Symptoms mimic an **allergic reaction**: flushing, headache, palpitations, urticaria, diarrhea *Staphylococcus* - ***Staphylococcus aureus*** causes **staphylococcal food poisoning** through preformed **enterotoxins** (not histamine) - Associated with protein-rich foods left at room temperature - Causes rapid-onset nausea, vomiting, and abdominal cramps - **Not a significant cause** of scombroid fish poisoning *Salmonella* - ***Salmonella*** species cause **gastroenteritis** through direct infection and invasion of intestinal mucosa - Symptoms include **diarrhea**, **fever**, and **abdominal cramps** with longer incubation period (6-72 hours) - **Not associated** with histamine production or scombroid poisoning *P. aeruginosa* - ***Pseudomonas aeruginosa*** is an **opportunistic pathogen** causing hospital-acquired infections - Associated with wound infections, pneumonia, and UTIs in immunocompromised patients - **Not a cause** of foodborne histamine poisoning

Q: Which of the following methods is known as a fimbriectomy procedure?

Kroener procedure. ***Kroener procedure*** - The **Kroener procedure** is a method of **tubal ligation** particularly known as a **fimbriectomy**, where the fimbriated end of the fallopian tube is removed. - This sterilization technique primarily involves excising the **fimbriae**, preventing **ovum capture** and subsequent fertilization. *Uchida procedure* - The **Uchida procedure** involves **injecting a sclerosing solution** under the serosa of the fallopian tube, then excising a small segment and ligating the ends. - This method aims to **bury the fimbriated end** within the broad ligament, but it is not a fimbriectomy. *Irving procedure* - The **Irving procedure** involves **tying and transecting the fallopian tube**, then burying the severed medial end into the posterior wall of the uterus. - This technique is designed to prevent **fistula formation** and recanalization but does not involve fimbriectomy. *Madlener procedure* - The **Madlener procedure** involves **crushing a section** of the fallopian tube, usually a knuckle, and then ligating it. - This method is simpler but has a **higher failure rate** compared to other sterilization techniques and does not involve removal of the fimbriae.

Q: Long-standing pelvic inflammatory disease (PID) may lead to which of the following complications?

Hydrosalpinx. ***Hydrosalpinx*** - **Hydrosalpinx** is a condition where the fallopian tube is blocked and filled with serous fluid, representing the **end-stage of chronic pelvic inflammatory disease (PID)**. - Chronic inflammation from **repeated or inadequately treated PID** causes damage to the tubal epithelium, loss of fimbrial function, and **adhesions that seal the distal end of the tube**. - This leads to accumulation of sterile transudate within the obstructed tube, creating a **fluid-filled, dilated fallopian tube**. - It is a major cause of **tubal factor infertility** and increased risk of **ectopic pregnancy**. - Classic imaging finding: **sausage-shaped cystic structure** on ultrasound. *Uterine polyposis* - **Endometrial polyps** are benign growths arising from the endometrium, typically associated with **unopposed estrogen stimulation** or hormonal imbalances. - They are **not a complication of chronic PID** but rather a proliferative endometrial disorder. - Common causes include obesity, tamoxifen use, and perimenopause. *Asherman syndrome* - **Asherman syndrome** involves **intrauterine adhesions** (synechiae) causing partial or complete obliteration of the uterine cavity. - It typically results from **endometrial trauma** following procedures like **D&C (dilatation and curettage)**, particularly post-abortion or postpartum curettage. - While PID can cause adhesions, Asherman syndrome specifically refers to **intrauterine** adhesions, not a typical sequela of chronic PID, which primarily affects the **tubes and ovaries**. *Endometriosis* - **Endometriosis** is the presence of **endometrial tissue outside the uterine cavity**, most commonly on ovaries, pelvic peritoneum, and uterosacral ligaments. - It is thought to result from **retrograde menstruation** (Sampson's theory) and genetic/immune factors. - It is **not caused by PID** but is a distinct pathological entity with different etiology and pathophysiology.

Q: Which gene is primarily associated with Cowden syndrome?

PTEN. ***PTEN*** - Cowden syndrome is an **autosomal dominant** inherited disorder caused by germline mutations in the **PTEN (phosphatase and tensin homolog) tumor suppressor gene**. - The PTEN gene plays a crucial role in cell growth, proliferation, and apoptosis, and its dysfunction leads to uncontrolled cell growth and the development of multiple **hamartomas** and increased cancer risk. *TP53* - Mutations in the **TP53 gene** are primarily associated with Li-Fraumeni syndrome, a different inherited cancer predisposition syndrome characterized by a high risk of various cancers including sarcomas, breast cancer, and adrenocortical carcinoma. - While both inherited cancer syndromes involve tumor suppressor gene mutations, the specific gene affected and the clinical presentation differ significantly. *RB1* - The **RB1 gene** is a tumor suppressor gene primarily associated with **retinoblastoma**, a rare childhood eye cancer, and an increased risk of other cancers like osteosarcoma. - It plays a critical role in cell cycle regulation, and its mutation leads to uncontrolled cell division in the retina and other tissues. *KRAS* - The **KRAS gene** is an oncogene, not a tumor suppressor gene, and its mutations are frequently found in various sporadic cancers, particularly **colorectal cancer**, pancreatic cancer, and lung cancer. - KRAS mutations lead to constitutive activation of signaling pathways that promote cell growth and survival, but they are not the primary genetic cause of inherited Cowden syndrome.

Q: Anaplasia is

Lack of differentiation. ***Lack of differentiation*** - Anaplasia refers to a **loss of differentiation** in cells, making them more primitive and less specialized [1]. - It is often seen in **malignant tumors**, indicating a poor prognosis and aggressive behavior [1]. *Morphological changes* - While anaplasia involves **morphological changes**, this term is too broad and can relate to various cellular alterations, not exclusively anaplasia [1]. - Anaplasia specifically emphasizes **lack of differentiation**, distinct from general changes in cell appearance [1]. *Changing one type of epithelium to another* - This describes a process known as **metaplasia**, where one adult cell type transforms into another, not anaplasia. - Anaplasia signifies a **de-differentiation** rather than a change to a different epithelial type [1]. *Nuclear chromatin* - While changes in **nuclear chromatin** can occur in anaplastic cells, this does not define anaplasia itself [1]. - Anaplasia primarily refers to **loss of cell differentiation**, making this option insufficient to describe the concept [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Neoplasia, pp. 276-280.

Q: In hypovolemic shock there is -

Decreased cardiac output. ***Decreased cardiac output*** - **Hypovolemic shock** is fundamentally defined by **decreased circulating blood volume**, which leads to **decreased venous return** to the heart. - According to the **Frank-Starling mechanism**, decreased venous return leads to **decreased preload**, which results in **decreased stroke volume** and consequently **decreased cardiac output**. - This is the **primary hemodynamic characteristic** of hypovolemic shock and is present in ALL cases. - Decreased cardiac output triggers all the compensatory mechanisms seen in hypovolemic shock, including sympathetic activation and RAAS activation. *Afferent arteriolar constriction* - While afferent arteriolar constriction does occur in hypovolemic shock due to **sympathetic activation**, it is a **compensatory response** rather than the primary feature. - The predominant effect at the kidney level is actually a combination of both afferent and efferent arteriolar changes. - This occurs secondary to the decreased cardiac output. *Efferent arteriolar constriction* - **Efferent arteriolar constriction** is mediated primarily by **angiotensin II** and is actually MORE prominent than afferent constriction. - This helps **maintain glomerular filtration rate (GFR)** despite reduced renal blood flow by increasing glomerular hydrostatic pressure. - However, this is also a compensatory response, not the primary feature of hypovolemic shock. *Increased blood flow to kidney* - This is incorrect as hypovolemic shock causes **decreased renal blood flow**. - Blood is redistributed away from the kidneys to vital organs like the heart and brain through compensatory vasoconstriction.

Q: What is the structure seen in the X-ray?

Stent. ***Stent*** - The image clearly shows **bilateral coiled structures** (pigtails) at the proximal and distal ends within the renal pelvis and bladder, which are characteristic features of **double J stents (ureteral stents)**. - These devices are used to maintain patency in the **ureters**, often to bypass obstructions or facilitate urine drainage. *Surgical clips* - **Surgical clips** are typically small, dense, metallic objects used to ligate vessels or tissue, appearing as tiny, bright specks on X-rays. - The structures seen in the image are long, tubular, and coiled, which is inconsistent with the appearance of surgical clips. *Foley catheter* - A **Foley catheter** is a flexible tube inserted into the bladder to drain urine, sometimes with a balloon tip. - It would typically be seen entirely within the **bladder**, and its path would not extend bilaterally into the renal pelvis as shown. *Intravesical wire* - An **intravesical wire** (a wire entirely within the bladder) would appear as a coiled or linear structure confined to the bladder itself. - The structures in the image extend from the renal region down into the bladder, traversing the **ureters**, which is not typical for an intravesical wire.

Question 1

Which chromosome is responsible for the production of MIF?

Accepted Answer

Chromosome 22

Answer

Y chromosome

Answer

Chromosome 16

Answer

X Chromosome

Question 2

Which of the following is an example of an X-linked disorder?

Accepted Answer

Color blindness

Answer

Thalassemia

Answer

Azoospermia

Answer

Sickle cell anemia

Question 3

Patient presenting with cutaneous vasculitis, glomerulonephritis, peripheral neuropathy, Which investigation is to be performed next that will help you diagnose the condition?

Accepted Answer

ANCA

Answer

RA factor

Answer

Hbsag

Answer

MIF

Question 4

Which of the following organisms is MOST associated with histamine production in scombroid fish poisoning?

Accepted Answer

Morganella morganii

Answer

P. aeruginosa

Answer

Staphylococcus

Answer

Salmonella

Question 5

Which of the following methods is known as a fimbriectomy procedure?

Accepted Answer

Kroener procedure

Answer

Uchida procedure

Answer

Irving procedure

Answer

Madlener procedure

Question 6

Long-standing pelvic inflammatory disease (PID) may lead to which of the following complications?

Accepted Answer

Hydrosalpinx

Answer

Uterine polyposis

Answer

Endometriosis

Answer

Asherman syndrome

Question 7

Which gene is primarily associated with Cowden syndrome?

Accepted Answer

PTEN

Answer

RB1

Answer

KRAS

Answer

TP53

Question 8

Anaplasia is

Accepted Answer

Lack of differentiation

Answer

Changing one type of epithelium to another

Answer

Nuclear chromatin

Answer

Morphological changes

Question 9

In hypovolemic shock there is -

Accepted Answer

Decreased cardiac output

Answer

Efferent arteriolar constriction

Answer

Increased blood flow to kidney

Answer

Afferent arteriolar constriction

Question 10

What is the structure seen in the X-ray?

Accepted Answer

Stent

Answer

Surgical clips

Answer

Foley catheter

Answer

Intravesical wire

NEET-PG 2018

Biochemistry

Internal Medicine

Microbiology

Obstetrics and Gynecology

Pathology

Physiology

Radiology