Path Lab Exam 2 Flashcards
B lymphoblast characteristics
Kappa, lambda, CD10+ [CALLA] , TdT+, CD2-, CD7-, CD19+
What is the biochemical function of NF1?
NF1 encodes a GTPase-activating protein (GAP) that facilitates the inactivation of RAS by converting RAS-GTP to RAS-GDP. Thus, NF1 downregulates the function of RAS.
Methods used to treat breast adenimocarcinoma
- Oophorectomy to deplete the supply of estrogen
- Tamoxifen to interrupt the binding of estrogen to its receptor
Do you know how immunohistochemical staining is done?
Immunohistochemical staining requires an antibody against the target protein to be detected. The antibody is conjugated to an enzyme (eg, horseradish peroxidase) that converts a colorless compound into a chromogen. In this way, any antibody binding to the tissue can be visualized.
What is the significance of a positive von Williebrand factor in terms of the probability of distant metastases?
The von Willebrand factor staining correlates with the degree of angiogenesis, which predicts the risk of metastases.
*Secreted by endothelial cells
Which family of cell surface receptors includes the HER2 protein?
The epidermal growth factor receptor family of tyrosine kinases.
How does the presence of carcinoma cells in the cerebrospinal fluid influence tumor staging? How does it influence grading?
The presence of cells in the CSF indicates distant metastases, and hence the tumor stage is increased to stage IV. Because the cells still appear to have a differentiated feature (mucin secretion), the tumor grade is not affected by this finding.
What therapeutic approaches may be used to treat Gaucher disease?
In patients who are thrombocytopenic, splenectomy can improve platelet counts. Splenectomy also reduces the production of glucocerebrosides, because a major source of their accumulation are membranes of red cells and white cells that are normally destroyed in the spleen. Enzyme replacement therapy can reduce further glucocerebroside accumulation.
What are causes of low platelet counts in patients with Gaucher disease?
Low platelet counts may be due to marrow compromise by Gaucher cells or to accelerated destruction of platelets by an enlarged spleen.
In what other tissues may Gaucher cells accumulate?
In any part of the mononuclear phagocyte system (eg, liver, lymph nodes, tonsils). In the neuronopathic forms, Gaucher cells are found in the Virchow-Robin spaces in the brain.
What is the source of the glucocerebroside accumulation in the spleen?
In the spleen, the stored glucocerebrosides are derived from the breakdown of cell membranes of red blood cells and white blood cells.
How does the molecular defect in cystic fibrosis lead to lung disease?
The abnormal regulation of chloride (and coupled sodium) transport across the bronchial epithelium causes the mucous secretions to become dehydrated. Abnormal bicarbonate ion transport, also mediated by CFTR, may result in acidic secretions, which lead to precipitation of mucus. The thick, dehydrated secretions impair the mucociliary action of the respiratory epithelium, leading to poor clearance of the secretions and bacteria. Additionally, because of its abnormal chemistry, the airway surface fluid in cystic fibrosis has inadequate endogenous antibacterial activity.
What is the most common cardiovascular malformation in Turner syndrome?
Coarctation of the aorta.
What are the most common abnormalities of the genitourinary system in Turner syndrome?
Horseshoe kidney and streak (fibrotic) ovaries.
What is the state of X chromosome inactivation in Klinefelter syndrome?
One X chromosome is inactivated.
