PubMed Health⌕ Search

Biomedical subjects

Ruth L Katz

Publications and source records attributed to Ruth L Katz.

24 records · Page 2Linked to original sources

Rapid detection of IgH/BCL2 rearrangement in follicular lymphoma by interphase fluorescence in situ hybridization with bacterial artificial chromosome probes.

Follicular lymphomas (FLs) can be difficult to diagnose on aspirated specimens since the architectural pattern is not present. FLs characteristically have rearrangements in the IgH and BCL2 genes resulting from the reciprocal t(14;18) (q32; q21) translocation. Because of the dispersed distribution of breakpoints, fluorescence in situ hybridization (FISH) using genomic probes that span or flank the breakpoints is ideal for detecting this rearrangement in fine-needle aspiration (FNA) biopsies. To develop a set of probes, a bacterial artificial chromosome library was screened and the clones were mapped by fiber FISH. The probes were produced by the direct incorporation of fluorochrome-labeled nucleotides. The colocalization base FISH assay was applied to Cytospin preparations from FNA biopsies of lymph nodes from 26 patients with FL and 10 patients without FL. In those with FL, the percentage of cells with at least one IgH/BCL2 fusion signal ranged from 22% to 100% (mean, 63%), which was statistically significantly higher than that in FL-negative samples (mean, 2.7%). The probes demonstrated a significantly lower cutoff value (7%) in normal controls and effectively reduced the false-positive rate in FL-negative cases. These results were confirmed with fiber FISH assays on the same specimens. This interphase FISH assay is rapid and reliable for detecting rearrangements in the IGH/BCL2 gene, thereby aiding in the diagnosis of FL on FNA biopsy specimens.

Chromosomes, Artificial, Bacterial↗

Use of interphase fluorescence in situ hybridization as a powerful diagnostic tool in cytology.

Interphase fluorescence in situ hybridization (I-FISH) using labeled nucleic acid probes detects chromosomal and genetic aberrations at a cellular level. I-FISH is a relatively fast and sensitive technique for evaluating a large number of cells and revealing more specific information than other techniques. It has been proven to be an invaluable molecular test in cytologic analyses for the detection of subtle genetic alterations that correlate with disease progression. In this postgenomic era, with the draft of the human genome available and expansion of the knowledge of tumor-specific genetic changes, the application of I-FISH probes in cytologic analysis should be of great value in the early detection, risk assessment, and monitoring of therapy efficacy in cancer. Here, we outline the principle of the I-FISH procedure, present suggestions to efficiently analyze cytologic materials, provide examples of practical applications, and discuss new aspects of the technique.

DNA, Neoplasm↗

Discrepancies in the immunophenotype of lymphoma cells in samples obtained simultaneously from different anatomic sites.

Few studies have compared the immunophenotypic profiles of non-Hodgkin lymphoma (NHL) cells obtained simultaneously from different anatomic sites. In the present study, we compared flow cytometry immunophenotypic results in 64 consecutive NHL cases in which aspiration or biopsy of 2 sites was performed within 30 days to assess the potential discrepancy rate. In 14 cases (22%), discordant antigen expression was identified, including 4 (36%) of 11 cases with discordant morphologic features and 10 (19%) of 53 cases with concordant morphologic features in the 2 samples. Discrepancies involved 1 antigen in 10 patients and 2 antigens in 4 patients. Antigens most frequently discrepant included CD5 (n = 4), FMC7 (n = 3), and CD20 (n = 3). We conclude that the immunophenotype of NHL cells is generally stable, yet discrepancies can occur in a subset of patients. Differences in immunophenotype may relate to mechanisms of disease dissemination, influence of the microenvironment, or differential response to therapy.

Adult↗

Grading follicular lymphoma on fine needle aspiration specimens. Comparison with proliferative index by DNA image analysis and Ki-67 labeling index.

OBJECTIVE: To determine whether follicular lymphoma (FL) can be graded on fine needle aspiration (FNA) biopsies by determining the percentage of centroblasts in the neoplastic follicles on the smears. STUDY DESIGN: Eighty-nine cases of histologically confirmed cases of FL, including 31 grade 1, 46 grade 2 and 12 grade 3, were evaluated. Proliferative index (PI) by DNA image analysis (DIA) and Ki-67 labeling index (LI) were obtained on all cases. A minimum of 200 cells were counted per case (range, 200-800 cells) at 40x magnification, and the number of large cells (centroblasts) was expressed as a percentage of the total number of cells counted within the follicles. RESULTS: The percentage of centroblasts in the follicular aggregates was 9.7 +/- 2.9% in grade 1 FLs, 24.7 +/- 5.6% in grade 2 and 48.4 +/- 7.5% in grade 3. These differences were significant (P < .05). DNA image analysis of PI and Ki-67 LI differed significantly between grade 1 FLs and grade 2 and 3 FLs (P < .05), but there were no significant differences between grade 2 and 3 FLs. CONCLUSION: Determining the percentage of centroblasts in the follicular aggregates on FNA specimens is a good method of grading FLs. Using the percentage of centroblasts per follicular structure, FL grades 1, 2 and 3 were adequately distinguished. PI by DIA and Ki-67 LI clearly distinguished FL grade 1 from FL grades 2 and 3; however, it did not clearly distinguish between grades 2 and 3.

Adult↗

Genomic profiles in stage I primary non small cell lung cancer using comparative genomic hybridization analysis of cDNA microarrays.

To investigate the genomic aberrations that are involved in lung tumorigenesis and therefore may be developed as biomarkers for lung cancer diagnosis, we characterized the genomic copy number changes associated with individual genes in 14 tumors from patients with primary non small cell lung cancer (NSCLC). Six squamous cell carcinomas (SQCAs) and eight adenocarcinomas (ADCAs) were examined by high-resolution comparative genomic hybridization (CGH) analysis of cDNA microarray. The SQCAs and ADCAs shared common frequency distributions of recurrent genomic gains of 63 genes and losses of 72 genes. Cluster analysis using 57 genes defined the genomic differences between these two major histologic types of NSCLC. Genomic aberrations from a set of 18 genes showed distinct difference of primary ADCAs from their paired normal lung tissues. The genomic copy number of four genes was validated by fluorescence in situ hybridization of 32 primary NSCLC tumors, including those used for cDNA microarray CGH analysis; a strong correlation with cDNA microarray CGH data emerged. The identified genomic aberrations may be involved in the initiation and progression of lung tumorigenesis and, most importantly, may be developed as new biomarkers for the early detection and classification of lung cancer.

Adenocarcinoma↗