Chapter 2: Cell Injury, Cell Death, and Aging
A patient in the emergency department is determined to have elevated blood levels of troponin I. Measurements of levels of this protein are of clinical utility because they indicate which of the following in regard to cardiac muscle tissue?
Explanation: Troponin I is an enzyme found specifically within cardiac myocytes. Release into the blood is associated with disruption of such cell membranes, a finding associated with cell death (i.e., necrosis). Ischemia might or might not result in cell death and enzyme release depending on degree and length of time. The other choices would not be expected to be associated with cardiac myocyte cell death.
A pathologist examines a specimen of cardiac tissues and describes it as demonstrating necrosis. This is most clearly demonstrated by which of the following in the Figure 2-70.
A. Lack of nuclei in myocytes
B. Staining properties of myocytes
C. Diameter (thickness) of myocytes
D. Striations in myocytes
Explanation: At the light microscopic level, lack of nuclei is a clear sign of cellular necrosis. Although all the other choices may occur in cases of cell injury, they may occur in cells which have been reversibly injured. Loss of nuclei is an irreversible process.
Which of the following descriptive terms would always raise clinical concern in a biopsy report?
Explanation: Dysplasia is an abnormal change in the pattern of growth of cells in tissue. It is often considered as a precursor to neoplasia. All the other descriptors may be normative elements to physiological stress or may be indicators of pathogenesis
A pathologist examines a biopsy from the trachea of a smoker (patient). The change in tissue she observes would best be described using which of the following terms?