MDS PREP
What is the primary function of protein S?
1) Inhibition of factor Xa
2) Inhibition of factor VIIIa
3) Inhibition of factor IIa (thrombin)
4) Activation of factor V
Protein S, in complex with activated protein C, acts as a cofactor for the inhibition of factor Xa, thus playing a role in the regulation of the coagulation cascade and preventing thrombus formation.
What is the role of angiotensinogen in blood pressure regulation?
1) It is a precursor to angiotensin II, which is a potent vasoconstrictor and stimulant of aldosterone release.
2) It is a precursor to angiotensin I, which has no direct role in blood pressure regulation.
3) It acts as a co-factor in the production of bradykinin, a vasodilator.
4) It is a potent inhibitor of the renin-angiotensin system.
Angiotensinogen is converted to angiotensin II by the action of renin and angiotensin-converting enzyme (ACE). Angiotensin II is a potent vasoconstrictor and stimulates the release of aldosterone from the adrenal cortex, leading to sodium and water retention and an increase in blood pressure.
Which of the following is NOT a type of E. coli associated with diarrheal disease?
1) Enterotoxigenic E. coli (ETEC)
2) Enteropathogenic E. coli (EPEC)
3) Enterohemorrhagic E. coli (EHEC)
4) Enteroaggregative E. coli (EAEC)
ETEC, EIEC, and EAEC are all types of E. coli that can cause diarrheal disease through various mechanisms. EPEC is typically associated with gastrointestinal illness, particularly in children, but does not typically cause the severe forms of diarrhea seen with ETEC or EHEC.
What is the primary mechanism of injury in alcoholic liver disease?
1) Direct cytotoxicity of ethanol
2) Oxidative stress
3) Lipid peroxidation
4) Cytokine-mediated inflammation
Cytokine-mediated inflammation is a major mechanism in alcoholic liver disease. TNF is the primary cytokine involved, with other cytokines such as IL-1, IL-6, and IL-8 also contributing to cell injury. These cytokines are produced in response to reactive oxygen species and other toxic metabolites of ethanol.
What is the major effector of cell injury in alcoholic hepatitis?
1) Tumor Necrosis Factor (TNF)
2) Interferon gamma (IFN-?)
3) Interleukin-10 (IL-10)
4) Interleukin-4 (IL-4)
TNF is considered the main effector of injury in alcoholic hepatitis. It is produced by activated macrophages, particularly Kupffer cells, and plays a critical role in the initiation and perpetuation of inflammation and necrosis in the liver.
A 55-year-old male with a history of chronic obstructive pulmonary disease (COPD) presents with increasing shortness of breath and cough with greenish sputum. His chest X-ray shows consolidation in the right middle lobe. Which of the following is the most likely pathogen?
1) Streptococcus pneumoniae
2) Haemophilus influenzae
3) Mycoplasma pneumoniae
4) Legionella pneumophila
In a patient with COPD presenting with community-acquired pneumonia, the most common bacterial pathogen is Streptococcus pneumoniae. The consolidation on chest X-ray and the presence of purulent sputum are characteristic features of bacterial pneumonia.
A 30-year-old male presents with a history of recurrent fever, chills, and pain in the right iliac fossa. His urinalysis is normal. His blood tests reveal leukocytosis and an elevated ESR. An ultrasound shows a right sided mass. Which of the following is the most likely diagnosis?
1) Pyelonephritis
2) Crohn's disease
3) Tubo-ovarian abscess
4) Appendicitis
The combination of fever, chills, and right iliac fossa pain with a pelvic mass and leukocytosis is most indicative of a tubo-ovarian abscess. This condition is often a complication of pelvic inflammatory disease, which can be caused by a variety of bacterial pathogens including sexually transmitted infections.
In restrictive lung disease
1) Increasing of FEV1/FVC and compliance of lung decreasing
2) Decreasing of FEV1/FVC and compliance of lung decreasing
3) Increasing of FEV1/FVC and compliance of lung increasing
4) Decreasing of FEV1/FVC and compliance of lung increasing
General Medicine
Answer: 1
In restrictive lung disease, the FEV1/FVC ratio and compliance of the lung are
decreasing.
Restrictive lung diseases, such as pulmonary fibrosis or severe asthma, are
characterized by a decrease in the lung's ability to expand due to factors like
stiffening of the lung tissue or a reduction in the volume of the thoracic
cavity. As a result, the forced expiratory volume in one second (FEV1) is
reduced in relation to the forced vital capacity (FVC), leading to a decreased
FEV1/FVC ratio. Additionally, the compliance of the lung, which is a measure of
the lung's ability to expand and contract, is also decreased in these conditions
because the lung tissue becomes less elastic.