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Biomedical subjects

D Zwick

Publications and source records attributed to D Zwick.

6 recordsLinked to original sources

Vasoactive intestinal peptide receptor expression on human lymphoblasts.

This study was designed to determine which (if any) subtypes of leukemic blasts express a functional receptor for vasoactive intestinal peptide (VIP). Blasts harvested from bone marrow of 38 newly diagnosed patients were classified as acute lymphocytic leukemia (CALLA + pre-B-cell leukemia, CALLA-, pre-B-cell leukemia, T-cell leukemia) or acute myeloid leukemia based on cytochemical and histochemical markers. Of the 32 patients with lymphocytic leukemia, 22 expressed the VIP receptor as evidenced by VIP-mediated activation of adenylate cyclase in cell homogenates. Binding of 125I-VIP to ALL cells correlated with the ability of VIP to activate adenylate cyclase. The VIP receptor was not identified in myeloid blasts from any of six patients. Further correlation of 125I-VIP binding and VIP-mediated stimulation of adenylate cyclase was demonstrated in transformed cell lines: a pre-B-cell line (Nalm 6) and a T-cell line (Molt 4b) exhibited high-affinity binding of 125I-VIP and VIP-mediated activation of adenylate cyclase, whereas neither the histiocytic line (U937) nor the myelocytic line (HL60) appeared to express the VIP receptor. These observations suggest a role for VIP in the proliferation or differentiation of human T and B lymphocytes.

Adenylyl Cyclases↗

Central spinal myelinolysis.

A midline lesion of the funiculus gracilis was found in four patients with histories of alcoholism, nutritional disturbance, and repeated episodes of electrolyte imbalance. Histologic and anatomic abnormalities were similar to those of central pontine myelinolysis. Sodium imbalance may play a role in the pathogenesis of both conditions.

Adult↗

Comparison between flow cytometric and cytogenetic tumor cell DNA content using a simple flow sample preparation method: ploidy comparison of 86 fresh pediatric tumors.

A comparison of tumor ploidy by flow cytometry (FL) and cytogenetics (CYG) was made in 86 fresh pediatric solid (n = 47) and hematopoietic (n = 39) tumors using simple sampling and semiautomated proprietary FL preparation methods and defined histogram interpretive criteria. Tumor karyotypes with 44-48 chromosomes were regarded as CYG diploid and other chromosomal complements CYG aneuploid for comparison purposes. Five histograms were uninterpretable and nine cases failed to produce 15 or more metaphases for karyotyping. Mean G0/G1 peak coefficients of variation of all 86 cases were 2.7 and 3.0 for the diploid and aneuploid populations, respectively. Of the 72 eligible cases, 41 were concordant diploid and 16 concordant aneuploid with an overall concordance of 79%. The DNA index and karyotypic index correlation coefficient was 0.92 for the 16 concordant aneuploid cases. Analysis of the 15 discordant cases highlights the limitations of both methods and of the histogram interpretive criteria and indicates that FL is probably more sensitive for detection of tumor aneuploidy as defined and detected by these methods.

Aneuploidy↗