Nokea
Which of the following cephalosporins has activity against gram negative anaerobic bacteria like Bacteroides fragilis, and the only cephalosporins that cross the blood brain barrier and enter the brain?
- A. Ceftriaxone
- B. Cefoxitin
- C. Cephalexin
- D. Cefixime
Correct Answer: A
Rationale: Rationale:
1. Ceftriaxone is a third-generation cephalosporin known for broad-spectrum coverage.
2. It has excellent activity against gram-negative anaerobes such as Bacteroides fragilis.
3. It is also one of the cephalosporins that can penetrate the blood-brain barrier.
4. The other choices do not have the same anaerobic coverage or BBB penetration.
Summary:
- B: Cefoxitin is a second-generation cephalosporin with anaerobic coverage but does not cross the BBB.
- C: Cephalexin is a first-generation cephalosporin with limited anaerobic activity and no BBB penetration.
- D: Cefixime is a third-generation cephalosporin with no anaerobic activity or BBB penetration.
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A patient with HIV-AIDS being treated with combined antiviral drugs and * immunosuppressive agents, develops an opportunistic infection caused by Pneumocystis caranii. Which of the following drugs most likely be used in the treatment of pulmonary infection caused by P, caranii?
- A. Metronidazole
- B. Carbenicillin
- C. Trimthoprim /Sulfametoxazole
- D. Penicillin G
Correct Answer: C
Rationale: The correct answer is C: Trimethoprim/Sulfamethoxazole. This combination is the first-line treatment for Pneumocystis carinii pneumonia in patients with HIV-AIDS due to its efficacy against the organism. Trimethoprim inhibits bacterial folic acid synthesis, while sulfamethoxazole inhibits bacterial dihydrofolic acid formation. These drugs work synergistically to target different steps in the folic acid synthesis pathway of Pneumocystis carinii, leading to its effective eradication. Metronidazole (A) is used for anaerobic bacterial infections, Carbenicillin (B) is a penicillin derivative mainly used for Gram-negative bacteria, and Penicillin G (D) is not effective against Pneumocystis carinii.
Furosemide acts by inhibiting the following in the renal tubular cell: *
- A. Na +K + ATPase
- B. Na +/Cl - transporter
- C. Na +K +/ 2Cl - transporter
- D. Na +H + antiporter
Correct Answer: C
Rationale: Furosemide inhibits the Na+K+/2Cl- transporter in the renal tubular cell. This transporter is responsible for reabsorbing sodium, potassium, and chloride ions from the urine back into the bloodstream. By inhibiting this transporter, furosemide prevents the reabsorption of these ions, leading to increased excretion of water and electrolytes, thereby promoting diuresis. Na+K+ ATPase (A) is not the target of furosemide. Na+/Cl- transporter (B) is not the primary mechanism of action for furosemide. Na+H+ antiporter (D) is not the target of furosemide in the renal tubular cell.
One of the primary functions of the kidney is to filter blood in order to remove substances that have no useful function in the body. Which of the following is the correct path of blood from the abdominal aorta to the inferior vena cava (IVC)?
- A. abdominal aorta – renal arteries – segmental arteries – interlobar arteries – arcuate arteries – interlobular arteries – efferent arteries – glomerulus – afferent arteries – peritubular capillaries – interlobular veins – arcuate veins – interlobar veins – renal veins – inferior vena cava
- B. abdominal aorta – renal arteries – interlobar arteries – segmental arteries – arcuate arteries – interlobular arteries – afferent arteries – glomerulus – efferent arteries – peritubular capillaries – interlobular veins – arcuate veins – interlobar veins – renal veins – inferior vena cava
- C. abdominal aorta – renal arteries – segmental arteries – interlobar arteries – arcuate arteries – interlobular arteries – afferent arteries – glomerulus – efferent arteries – peritubular capillaries – interlobular veins – arcuate veins – interlobar veins – renal veins – inferior vena cava
- D. abdominal aorta – renal arteries – interlobar arteries – interlobular arteries – segmental arteries – arcuate arteries – afferent arteries – glomerulus – efferent arteries – peritubular capillaries – interlobular veins – arcuate veins – interlobar veins – renal veins – inferior vena cava
Correct Answer: C
Rationale: The correct path of blood flow in the kidney is from the abdominal aorta to the renal arteries, then to the segmental arteries, followed by interlobar arteries, arcuate arteries, interlobular arteries, afferent arteries, glomerulus, efferent arteries, peritubular capillaries, interlobular veins, arcuate veins, interlobar veins, renal veins, and finally to the inferior vena cava. Choice C accurately follows this sequential flow of blood, making it the correct answer.
Explanation for why other choices are incorrect:
- Choice A has the incorrect sequence of interlobar and interlobular arteries, which disrupts the correct flow.
- Choice B also has an incorrect sequence of interlobar and interlobular arteries, leading to an inaccurate path.
- Choice D has the interlobar and interlobular arteries in the wrong order, deviating from the correct blood flow pathway.
Which of the following drug is a radical curative in plasmodium vivax malaria * and is used as prophylaxis for malaria at Chloroquine sensitive regions
- A. Quinine
- B. Primaquine
- C. Meoquine
- D. Chloroquine
Correct Answer: B
Rationale: The correct answer is B: Primaquine. Primaquine is a radical curative drug for Plasmodium vivax malaria, as it targets the hypnozoite stage in the liver, preventing relapses. It is also used as prophylaxis in Chloroquine-sensitive regions due to its efficacy against P. vivax and P. ovale.
Rationale:
1. Quinine (A) is not a radical curative drug for P. vivax malaria. It is mainly used for treatment of acute malaria.
2. Meoquine (C) is not a radical curative drug for P. vivax malaria and is used more for prophylaxis in certain regions.
3. Chloroquine (D) is not a radical curative drug for P. vivax malaria and is primarily used for treatment and prevention of malaria caused by susceptible strains of Plasmodium species.
Which of the following antibiotics is considered safe to use in newborn * babies?
- A. Chloramphenicol
- B. Trimethoprim/Sulfamethoxazole
- C. Teracyclines
- D. Ampicillin
Correct Answer: D
Rationale: The correct answer is D: Ampicillin. Ampicillin is considered safe for use in newborn babies because it is a commonly used antibiotic in neonates and has a favorable safety profile. It is effective against a wide range of bacteria commonly found in newborns. Chloramphenicol (A) can cause serious side effects like gray baby syndrome. Trimethoprim/Sulfamethoxazole (B) is not recommended in newborns due to potential risks. Tetracyclines (C) can lead to tooth discoloration and bone growth inhibition in newborns.