CT-guided biopsy of focal lesions in patients with multiple myeloma may reveal new and more aggressive cytogenetic abnormalities.

Background And Purpose: Cytogenetic abnormalities, especially chromosome 13 deletion, are high-risk factors for multiple myeloma. Attaining the highest detection rates of cytogenetic abnormalities is important to provide accurate prognostic information to the referring oncologist. The purpose of this study was to use CT-guided percutaneous fine-needle aspiration bone biopsy (CT-guided FNA) of MR-detected focal lesions in patients with multiple myeloma to increase identification of abnormal cytogenetics.

Use of power Doppler in pediatric neurosonography: a pictorial essay.

In pediatric neurosonography, conventional color Doppler imaging has been the primary adjunct to routine gray-scale imaging. Power Doppler sonography is a relatively recent development that does not have the limitations of conventional color Doppler ultrasound. The power Doppler technique measures the energy of moving red blood cells instead of the velocity and direction of flow.

In vivo and in vitro formation and dissociation of HLA-DR complexes with invariant chain-derived peptides.

HLA-DR molecules associated with class II-associated invariant chain peptides (CLIP) are generated in vivo as an intermediate in class II maturation. Such complexes can be produced in vitro by proteolytic digestion of DR alpha beta I complexes, suggesting that CLIP is a residual fragment that remains associated with class II molecules following I chain degradation. In vitro, CLIP dissociation from DR alpha beta dimers occurs at different rates depending on the allele, and is facilitated by low pH and by detergents containing 8-10 carbon unbranched hydrocarbons, or by primary aliphatic amines or carboxylic acids.

Transport and intracellular distribution of MHC class II molecules and associated invariant chain in normal and antigen-processing mutant cell lines.

We have compared the intracellular transport and subcellular distribution of MHC class II-invariant chain complexes in a wild-type HLA-DR3 homozygous cell line and a mutant cell line, T2.DR3. The latter has a defect in antigen processing and accumulates HLA-DR3 molecules associated with an invariant chain-derived peptide (CLIP) rather than the normal complement of peptides derived from endocytosed proteins.

Intracellular transport and peptide binding properties of HLA class II glycoproteins.

Protein antigens internalized by an antigen presenting cell are degraded into peptides, a subset of which binds to the class II glycoproteins encoded by the major histocompatibility complex to form epitopes recognized by specific T cells. Current evidence suggests that the immunogenic peptides are generated in an endosomal, acidic compartment containing internalized antigen, proteinases, and exocytic class II molecules. These exocytic class II glycoproteins are associated during transport from the endoplasmic reticulum to the endosomal compartment with an additional glycoprotein, the invariant chain.