Decoupling illumination from isosurface generation using 4D light transport.

One way to provide global illumination for the scientist who performs an interactive sweep through a 3D scalar dataset is to pre-compute global illumination, resample the radiance onto a 3D grid, then use it as a 3D texture. The basic approach of repeatedly extracting isosurfaces, illuminating them, and then building a 3D illumination grid suffers from the non-uniform sampling that arises from coupling the sampling of radiance with the sampling of isosurfaces. We demonstrate how the illumination step can be decoupled from the isosurface extraction step by illuminating the entire 3D scalar function as a 3-manifold in 4-dimensional space. By reformulating light transport in a higher dimension, one can sample a 3D volume without requiring the radiance samples to aggregate along individual isosurfaces in the pre-computed illumination grid.

Diminished CD10, CD13, and CD15 expression in a differentiated granulocyte population in CML.

Flow cytometric analysis of cluster of differentiation (CD) markers of myeloid cells has been used in conjunction with cell morphology to diagnose chronic myelogenous leukemia (CML). In the present study, 16 cases of CML were studied for levels of expression of myeloid markers CD15, CD13, CD33, and CALLA, i.e., CD10 which is also expressed on mature granulocytes. In 11 (68.8%) of 16 cases, a differentiated granulocyte population was detected that showed decreased expression of both CD10 and CD13. CD10 was found to be negative in 1 (6.3%) case and showed decreased expression in 10 (62.5%) of the cases. CD13 showed decreased expression in 11 (68.8%) of the 16 cases. Of the 15 cases analyzed for CD15, 2 (13.3%) were negative and 6 (40%) showed decreased expression. Of the 11 cases which showed simultaneous diminished expression of CD10 and CD13, 8 (72.7%) also showed decreased expression of CD15. Of the antigens studied, CD33 was the only one to be consistently expressed at normal levels, i.e., 13 (81.3%) cases demonstrated normal expression. Therefore, these results point to frequently decreased expression levels of CD10, CD13, and CD15 and rarely decreased expression levels of CD33 in association with CML.

Contrasting antigenic maturation patterns in M0-M2 versus M3 acute myeloid leukemias.

Acute myelogenous leukemia (AML) is divided into 8 FAB subgroups based on differentiation and maturation properties of the neoplastic cells. Acute promyelocytic leukemia (APL), or M3 AML, is associated with disseminated intravascular coagulation (DIC). Flow cytometric immunophenotyping differentiates among the AML subtypes. Key markers in this classification include the myeloid antigens CD13 and CD33 and the hematopoietic precursor markers CD34 and HLA-DR. The present study analyzes and compares differences in the expression of these markers in 27 M0-M2 cases and 8 M3 cases. The M0-M2 cases generally expressed all four antigens. CD13 and CD33 were positively expressed in 23 (85.2%) and 21 (77.8%) of the 27 cases, respectively. CD34 and HLA-DR were present in 25 (92.6%) and 26 (96.3%) of the 27 cases, respectively. Analysis of the M3 cases revealed a different immunophenotype as CD13 and CD33 were each positive in all 8 (100%) M3 AML cases while CD34 and HLA-DR were negative in 6 (75%) and 8 (100%) of the 8 M3 cases, respectively. In contrast to expression of the early markers CD34 and HLA-DR in the M0-M2 group, these were negative in the M3 cases which were characterized by heterogeneous CD13 and generally homogeneous and bright CD33 expression.

The immunophenotype of pre-TALL/LBL revisited.

Flow cytometric analysis of cluster of differentiation (CD) markers in abnormal lymphocyte populations is crucial in the diagnosis of precursor T cell acute lymphoblastic leukemia (T-ALL)/lymphoblastic lymphoma (LBL). The World Health Organization (WHO) suggested immunophenotype for pre-T ALL/LBL typically includes the expression of TdT, cCD3, and CD7, while CD2, CD3, CD4, CD5, CD8, and CD10 are variably expressed. The myeloid antigens CD13 and CD33 are usually positive, whereas CD117 and cCD79a are infrequently expressed. Furthermore, there is frequent dual expression of CD4 and CD8. In the present investigation, 19 cases of pre-TALL/LBL were analyzed for selected CD marker expression. Fifteen of 19 cases studied were evaluated for TdT, cCD3, and cCD79a expression. Eleven (73.3%) positively expressed TdT, 15 (100%) positively expressed cCD3, and 9 (60%) positively expressed cCD79a. Of the 17 cases analyzed for CD7, CD5, and CD10 expression, CD7 and CD5 were positive in all 17 (100%) cases, whereas CD10 was positive in 8 (47.1%) cases. Of the 18 cases evaluated for CD2, CD3, CD4, CD8, and dual expression of CD4 and CD8, CD2 was expressed in 14 (77.8%), while CD3 was expressed in 7 (38.9%) cases. CD4 was positive in 11 (61.1%), and CD8 was expressed in 9 (50%). Dual expression of CD4 and CD8 occurred in only 4 (22.2%) of the cases. Of the 16 analyzed for CD13, CD33, and CD117, only 1 case (6.3%) expressed CD13, while 2 (12.5%) cases expressed CD33 and CD117. Thus, these data point to the need for a more extensive study to reevaluate the current WHO defined immunophenotype used in the diagnosis of pre-TALL/LBL.

Antigenic transformation in plasma cell dyscrasia.

The WHO immunophenotype for plasma cell myeloma is deletion of CD19 and CD20, usual expression of CD38, CD138, and CD56, and occasional expression of CD10. Of the 39 cases of plasma cell dyscrasia in our study, the mean fluorescence intensities (MFI) of CD38, CD138, CD56, and CD19 were quantified in 30 cases. CD19 was absent in 38 of the cases (97.4%), whereas CD138 and CD38 were expressed in all 39 cases (100%). Most cases expressed CD38 and CD138 brightly with MFI values greater than 501, whereas all other marker expression was moderate with MFI greater than 301. Whereas CD38/CD56 dual expression was observed in 25 cases (64.1%), 14 failed to express CD56 (35.9%). CD56 expression was bright in 16 cases (53.3%), moderate in 2 cases (6.7%), and negative in the remaining 12 cases (40%) with MFI values of 200 or less. CD117 expression was positive in 9 of 24 cases (37.5%). In 32 of 39 cases, 27 were negative for CD20 (84.4%) and 28 were negative for CD10 (87.5%). Our results point to the value of quantitative fluorescence intensity in the flow cytometric evaluation of CD molecular expression or deletion in the diagnosis of hematopathologic disorders, such as plasma cell dyscrasia.

CD79a expression in acute myeloid leukemia t(8;21) and the importance of cytogenetics in the diagnosis of leukemias with immunophenotypic ambiguity.

Acute leukemias that express antigens associated with more than one lineage have been classified as acute lymphocytic leukemia with myeloid markers, acute myeloid leukemia with lymphoid markers, or biphenotypic acute leukemia (BAL). Antibody to cytoplasmic CD79a has been recently introduced to flow cytometry. CD79a functions in and has a high degree of specificity for B-cell differentiation. It has only recently begun to be reported in biphenotypic acute leukemias. Cases of acute leukemia submitted to the flow cytometry laboratory were retrospectively reviewed beginning from the time analysis for cytoplasmic CD79a was added to leukemia and lymphoma panels. Among 89 cases of AML, 2 showed strong coexpression of CD79a. Both cases were differentiated FAB AML-M2 and demonstrated the t(8;21) with cytogenetics and the AML1/ETO rearrangement with fluorescence in situ hybridization (FISH). These are recurring abnormalities in FAB AML-M2. The immunophenotyping met proposed scoring criteria for a diagnosis of BAL. Nevertheless, the cytogenetic and FISH findings indicate that CD79a, despite its specificity for B-cell differentiation, represented the aberrant presence of a B-cell antigen in leukemias of distinct myeloid linage. It is doubtful that, in this setting, CD79a expression should be considered a manifestation of lineage ambiguity.

A comparative study of four serological tumor markers for the detection of breast cancer.

Breast cancer is currently the third most common cause of cancer in the world. Circulating tumor antigens are often used as a minimally invasive tool for noting breast cancer progression. The objective of this study was to compare four tumor antigens (CA 15-3, CA 27.29, alpha-fetoprotein [AFP], and carcinoembryonic antigen [CEA]) for their diagnostic efficacy in breast cancer patients. It was hypothesized that CA 15-3 would proved to be superior to CA 27.29, CEA, and AFP in assay performance. Tumor marker assays were performed according to the manufacturers' directions. Assays used in this study were CA 15-3 and CA 27.29 (Fujirebio Diagnostics/Centocor Inc.), AFP (Abbott Inc.), and CEA (Hybritech Inc.). A total of 554 patient samples were obtained from an area hospital, plus 200 healthy adult samples which were used for the determination of normal reference intervals. The patients included patients with no disease (184), with non-malignant disease (11), with breast cancer (87), and with other types of cancer (272). Diagnostic percent sensitivities for each marker were: CA 15-3 (63%), CA 27.29 (39%), CEA (22%), and AFP (22%). Diagnostic specificities for each marker were comparable, ranging from 80-88%. Analytical parameters were evaluated for the assays and compared favorably. We concluded that CA 15-3 was the best tumor antigen for use as a diagnostic aid and monitoring agent.