MDS PREP
What is the primary source of vitamin D3 in humans?
1) Diet
2) Skin synthesis from sunlight
3) Intestinal bacteria
4) Supplementation
The precursor of vitamin D3, 7-dehydrocholesterol, is present in the keratinocytes of the skin's stratum corneum. Upon exposure to UV light, it is converted into cholecalciferol (vitamin D3).
A 45-year-old male presents with severe epigastric pain radiating to the back, nausea, vomiting, and malaise after consuming a large meal at a buffet. His stool is watery and non-bloody. His blood pressure is normal. Which of the following is the most likely diagnosis?
1) Peptic ulcer
2) Gallstones
3) Pancreatitis
4) Clostridium perfringens food poisoning
The rapid onset of symptoms after a large meal at a buffet, along with the presence of severe epigastric pain and watery diarrhea, suggests a gastrointestinal infection. Clostridium perfringens is a common cause of foodborne illness and typically presents within 8 to 16 hours of ingestion. The condition is usually self-limiting and improves with supportive care.
Which of the following HLA types is most strongly associated with Celiac disease?
1) HLA-DQ2
2) HLA-DQ8
3) HLA-B8
4) HLA-DR3
The strongest genetic association with Celiac disease is with the HLA-DQ2 haplotype, which is found in the majority of patients with the condition.
In which of the following conditions is the prevalence of nephrotic syndrome more common in children than in adults?
1) Membranous nephropathy
2) Minimal-change disease
3) Focal segmental glomerulosclerosis
4) Membranoproliferative glomerulonephritis
Minimal-change disease is the most common cause of nephrotic syndrome in children, with a prevalence of 65%. In contrast, it is less common in adults, affecting only 10% of cases.
What is the most common non-CNS manifestation of Wilson’s disease?
1) Hepatic cirrhosis
2) Cardiac dysfunction
3) Pancreatitis
4) Arthritis
While CNS manifestations are prominent in Wilson’s disease, hepatic cirrhosis is the most common non-CNS manifestation. It occurs due to the deposition of copper in the liver, leading to chronic liver damage.
What is the primary function of transferrin in the body?
1) Transport of iron
2) Transport of copper
3) Binding and transport of thyroid hormones
4) Lipoprotein assembly
Transferrin is a glycoprotein synthesized by the liver that acts as the primary iron-transport protein in the blood. It binds to iron and transfers it to cells that require it, such as erythrocytes for hemoglobin synthesis.
What is the most common symptom associated with H. pylori infection?
1) Abdominal pain
2) Nausea and vomiting
3) Diarrhea
4) Fatigue
While H. pylori infection can cause various symptoms, the most common is abdominal pain, often related to peptic ulcer disease.