A 24-year-old woman presents with cyclic pelvic pain, dysmenorrhea, and dyspareunia. On pelvic examination, tender nodules are palpated along the uterosacral ligaments. Which of the following conditions is most likely to be responsible for these findings?

Correct Answer: B

Rationale: The symptoms of cyclic pelvic pain, dysmenorrhea (painful menstruation), dyspareunia (painful intercourse), and tender nodules along the uterosacral ligaments are classic findings associated with endometriosis. In endometriosis, tissue similar to the lining of the uterus (endometrium) grows outside the uterus, commonly on the ovaries, fallopian tubes, and pelvic peritoneum. The presence of tender nodules along the uterosacral ligaments is known as "nodularity" and is a characteristic feature of advanced endometriosis. It occurs due to the formation of endometrial implants that respond to hormonal changes during the menstrual cycle, resulting in inflammation, scarring, and pain in affected areas.

Correct Answer: A

Rationale: Somatic hypermutation is the mechanism responsible for generating diversity in the antigen-binding sites of immunoglobulins. During somatic hypermutation, point mutations are introduced into the variable regions of immunoglobulin genes in B cells. These mutations occur randomly and lead to a wide range of amino acid changes in the antigen-binding sites of antibodies. As a result, a diverse repertoire of antibodies with varying specificities for different antigens is created. Gene rearrangement and isotype switching are other mechanisms that contribute to antibody diversity but do not specifically target the antigen-binding sites. Clonal expansion, on the other hand, refers to the proliferation of specific B cell clones after activation by antigens, which amplifies the immune response but does not directly impact the diversity of antigen-binding sites.

Correct Answer: A

Rationale: Fluticasone/salmeterol (Advair) is a combination medication consisting of an inhaled corticosteroid (fluticasone) and a long-acting beta-agonist (salmeterol). This combination medication is recommended for long-term control of asthma symptoms and for the prevention of exacerbations. Fluticasone reduces airway inflammation, while salmeterol helps to relax the muscles of the airways, improving breathing. Using this combination medication regularly can help manage asthma symptoms and reduce the risk of asthma attacks. It is not appropriate to use short-acting beta-agonists like albuterol (salbutamol) on a long-term basis for asthma control. Ipratropium bromide (Atrovent) is an anticholinergic bronchodilator that is more commonly used for chronic obstructive pulmonary disease (COPD

Correct Answer: B

Rationale: CPAP therapy is considered the gold standard treatment for obstructive sleep apnea (OSA) and is the most appropriate intervention for managing OSA and improving symptoms. CPAP therapy involves using a machine that delivers a continuous flow of air through a mask worn over the nose or mouth during sleep. This air pressure helps keep the airway open, preventing the collapse that causes apneas and snoring during sleep.

Correct Answer: A

Rationale: Patients with COPD are at increased risk for developing ventilator-induced lung injury (VILI) due to their underlying lung pathology. Using a low tidal volume strategy (6-8 ml/kg predicted body weight) has been shown to reduce the risk of VILI in these patients. Additionally, applying high positive end-expiratory pressure (PEEP) helps to recruit collapsed alveoli, improve oxygenation, and decrease the risk of barotrauma by keeping the alveoli open throughout the respiratory cycle. Therefore, the most appropriate ventilator settings to minimize the risk of VILI in a COPD patient with acute exacerbation and respiratory failure requiring mechanical ventilation would be low tidal volume and high PEEP.