A 55-year-old postmenopausal woman presents with vaginal bleeding. On pelvic examination, the cervix appears healthy, and there is no cervical motion tenderness. Which of the following conditions is most likely to be responsible for these findings?

Correct Answer: D

Rationale: In a 55-year-old postmenopausal woman presenting with vaginal bleeding and a healthy cervix on examination, the most likely cause would be a cervical polyp. Cervical polyps are benign growths that can occur on the cervix and are often asymptomatic but can occasionally cause postmenopausal bleeding. Their appearance on examination would typically be a non-malignant finding with no cervical motion tenderness. Cervical cancer, endometrial cancer, and vaginal cancer would typically present with different examination findings and risk factors.

Correct Answer: B

Rationale: T cell exhaustion is a state of T cell dysfunction that arises during chronic viral infections or cancer. In the case of a chronic viral infection, the persistent exposure to viral antigens leads to continuous stimulation of CD8+ cytotoxic T cells. Over time, this sustained stimulation can lead to T cell exhaustion, characterized by the upregulation of inhibitory receptors, impaired effector functions, and reduced proliferative capacity. As a result, despite the elevated levels of CD8+ T cells in the blood, their function may be compromised, ultimately impacting the immune response against the viral infection. In contrast, activation-induced cell death (AICD) may contribute to T cell loss during chronic infections but would not explain the persistently elevated CD8+ T cell levels. Thymic involution refers to the age-related decline in thymus function, which is not directly related to the observed increase in CD8+ T cells. Antigenic

Correct Answer: B

Rationale: Opsonization is a process in the immune response where opsonins, which are proteins such as antibodies and complement proteins, bind to pathogens such as bacteria, making them more easily recognized and engulfed by phagocytic cells like macrophages and neutrophils. This coating of pathogens by opsonins enhances the efficiency of phagocytosis, helping in the elimination of pathogens from the body. Opsonins do not facilitate cell lysis, neutralize toxins, or stimulate histamine release; their main function is to tag pathogens for phagocytosis.

Correct Answer: D

Rationale: Spiral CT angiography is the most appropriate test for confirming the diagnosis of pulmonary embolism (PE) in a patient with suspected PE. It is a non-invasive imaging modality that can detect filling defects within the pulmonary vasculature indicative of a clot. This diagnostic test has high sensitivity and specificity for diagnosing PE, making it a valuable tool in the management of patients with suspected PE.

Correct Answer: D

Rationale: In a patient with acute exacerbation of COPD who presents with hypercapnia and respiratory acidosis, the most appropriate ventilatory strategy is invasive mechanical ventilation with a lung protective strategy. This involves using lower tidal volumes and limiting plateau pressures to prevent ventilator-induced lung injury.