Bactericidal effect is:

Correct Answer: C

Rationale: The correct answer is C: Destroying of bacterial cells. Bactericidal effect refers to the ability to kill bacteria. This is achieved by directly destroying the bacterial cells, leading to their death. Inhibition of bacterial cell division (A) and young bacterial cell growth (B) refer to bacteriostatic effects, which only stop bacterial growth but do not kill the bacteria. Formation of bacterial L-form (D) is a phenomenon where bacteria lose their cell wall and become resistant to antibiotics, but it does not directly relate to bactericidal action.

Correct Answer: D

Rationale: The correct answer is D: Diloxanide. Diloxanide is a luminal amebicide, meaning it acts within the lumen of the intestines to target and eliminate amoebas residing there. This drug is specifically effective against amoebic cysts and is not absorbed systemically. Metronidazole (A) and Emetine (B) are tissue amebicides, which act systemically to target amoebas in tissues. Doxycycline (C) is an antibiotic commonly used for bacterial infections, not for treating amoebiasis. Therefore, Diloxanide (D) is the correct choice for a luminal amebicide drug.

Correct Answer: D

Rationale: The correct answer is D: All of the above. General contraindications for anticancer drugs include depression of bone marrow, which can lead to decreased production of blood cells; acute infections, as these drugs can further compromise the immune system; and severe hepatic and/or renal insufficiency, as these organs are responsible for drug metabolism and elimination. These contraindications are crucial to consider to prevent further harm to the patient. Choices A, B, and C individually are incorrect because they do not encompass all the general contraindications associated with anticancer drugs.

Correct Answer: C

Rationale: The correct answer is C: Procainamide. Procainamide blocks inactivated Na+ channels by binding to them preferentially when they are in the inactivated state. This mechanism helps decrease excitability in cardiac and neuronal tissues. Mexiletine (A) blocks both inactivated and activated Na+ channels, making it incorrect. Phenytoin (B) primarily blocks activated Na+ channels, not inactivated ones. Quinidine (D) blocks both inactivated and activated Na+ channels, so it is not the correct choice in this scenario.

Correct Answer: C

Rationale: The correct answer is C: Blockade of beta receptors of the vascular wall. Atenolol is a beta-blocker that works by blocking beta receptors in the vascular wall, leading to reduced sympathetic stimulation and vasodilation, ultimately lowering blood pressure. Choice A is incorrect as atenolol primarily affects beta receptors, not large veins. Choice B is incorrect as atenolol does not directly affect epinephrine release from the adrenal medulla. Choice D is incorrect as atenolol primarily acts at the beta receptors in the vascular wall rather than affecting sympathetic outflow from the vasomotor area.