Which of the following would NOT be a cause of prerenal failure?

A. Traveling abroad recently: While international travel can expose individuals to infectious diseases, it is not the most concerning factor in this case compared to his communal living situation.

B. Living in a large, crowded communal setting: Crowded living conditions significantly increase the risk of meningitis transmission, especially for bacterial types like Neisseria meningitidis which spread via respiratory droplets.

C. An infection of the brain tissue, typically due to a virus or bacteria: This describes encephalitis, not meningitis. Meningitis affects the protective membranes, not the brain tissue itself.

D. An inflammation of the protective membranes around the brain and spinal cord (meninges): This is the correct definition of meningitis and is the pathological hallmark of the disease.

E. Having an allergy to medications: Having an allergy to medications is important for safe patient care and medication administration, but it is not a risk factor for acquiring meningitis.

F. An inflammation of the lungs caused by a viral or bacterial infection: This describes pneumonia, not meningitis. It is unrelated to the direct cause of meningitis.

A. Tubular necrosis: Tubular necrosis refers to the death of tubular epithelial cells in the kidneys, commonly due to ischemia or toxins. This is not the primary defect in Potter syndrome, which involves developmental abnormalities rather than acute tubular injury.

B. Renal hyperplasia: Hyperplasia means increased cell number leading to organ enlargement. Potter syndrome typically involves renal hypoplasia or agenesis rather than hyperplasia, so this is not consistent with the syndrome’s defect.

C. Renal failure: Potter syndrome primarily results from bilateral renal agenesis or severe renal dysplasia, leading to absent or nonfunctional kidneys and subsequent renal failure. The lack of functional kidneys leads to oligohydramnios and the characteristic features of Potter syndrome.

D. Renal metaplasia: Metaplasia refers to abnormal transformation of one differentiated tissue type into another. This process is not the main defect in Potter syndrome, which is related to kidney development failure rather than abnormal tissue differentiation.