An older male reports to the clinic nurse that he sometimes feels chest pressure and becomes breathless. He further describes an event where he had to sit for about one hour before he felt better. He is asymptomatic at rest, but is concerned that he has had a heart attack. This clinical picture is consistent with which cardiac ischemic event?

Leukotrienes are inflammatory mediators derived from arachidonic acid metabolism, primarily produced by leukocytes (white blood cells) such as mast cells, eosinophils, and basophils. In the context of asthma, leukotrienes play a significant role in the pathophysiology of the disease by contributing to airway inflammation and bronchoconstriction. Here's a breakdown of their immune response:

A) Produce the sensation of itching:

Leukotrienes are not directly involved in producing the sensation of itching. Itching is often associated with histamine release rather than leukotrienes.

B) Tighten airway and produce mucous:

Correct. Leukotrienes are potent bronchoconstrictors that cause smooth muscle contraction in the airways, leading to narrowing (constriction) of the bronchioles. Additionally, they stimulate the secretion of mucus from goblet cells in the airway epithelium, contributing to airway obstruction and mucus production, which are characteristic features of asthma exacerbations.

C) Causes formation of bradykinin:

Bradykinin is a peptide mediator that is generated from the plasma protein kininogen and is involved in vasodilation, pain sensation, and inflammation. Leukotrienes are not directly responsible for the formation of bradykinin.

D) Serves as a receptor for antigen:

Leukotrienes do not serve as receptors for antigens. Instead, they are lipid mediators released in response to various stimuli, including allergens, infections, and irritants, and they act on specific receptors (e.g., leukotriene receptors) to exert their effects, such as bronchoconstriction and inflammation

Tumor lysis syndrome (TLS) is a potentially life-threatening oncologic emergency characterized by the rapid release of intracellular contents into the bloodstream following the destruction of cancer cells. This release can lead to metabolic disturbances, including hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia. Here's how the child's laboratory results are indicative of tumor lysis syndrome:

A) Wilm's tumor:

Wilms tumor is a type of kidney cancer that primarily affects children. However, it typically does not cause the metabolic disturbances seen in tumor lysis syndrome. Laboratory abnormalities in Wilms tumor are generally related to renal dysfunction and may include hematuria and proteinuria.

B) Tumor lysis syndrome:

Correct. Tumor lysis syndrome occurs when chemotherapy or radiation therapy causes a rapid breakdown of cancer cells, leading to the release of intracellular contents such as potassium, phosphorus, and uric acid into the bloodstream. The elevated potassium and phosphorus levels seen in the child's laboratory results are consistent with tumor lysis syndrome. Hyperkalemia (elevated potassium) and hyperphosphatemia (elevated phosphorus) are common metabolic disturbances in tumor lysis syndrome.

C) Superior vena cava syndrome:

Superior vena cava syndrome occurs when the superior vena cava, a major vein that carries blood from the upper body to the heart, becomes partially or completely obstructed. This obstruction can lead to symptoms such as facial swelling, dyspnea, and dilated neck veins. While superior vena cava syndrome may occur in cancer patients, it does not typically cause the metabolic disturbances seen in the child's laboratory results.

D) Hyperleukocytosis:

Hyperleukocytosis refers to an extremely high white blood cell count, which can occur in leukemia. While leukemia can lead to metabolic abnormalities, the child's laboratory results, particularly the elevated potassium and phosphorus levels, are more indicative of tumor lysis syndrome than hyperleukocytosis.