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Biomedical subjects

W C DeWolf

Publications and source records attributed to W C DeWolf.

At least 19 recordsLinked to original sources

Purification of a tumor-specific PNA-binding glycoprotein, gp200, from a human embryonal carcinoma cell line.

A 200-kDa peanut agglutinin (PNA)-binding glycoprotein, gp200, has been purified and partially characterized from the human embryonal carcinoma cell line, HT-E (833k). Tissue distribution analysis of this molecule by lectin blotting with PNA of detergent-extracted proteins from human cell lines and tissues demonstrated expression limited to nonseminomatous germ cell tumors. The 200-kDa protein was purified with lectin affinity and gel filtration chromatography. Purification to apparent homogeneity was demonstrated by one- and two-dimensional gel electrophoresis. Characterization of gp200 revealed it to be a surface integral membrane glycoprotein; however, gp200 could also be purified from the culture media of EC cells, suggesting gp200 has an extracellular role. The carbohydrate groups of gp200 are N-linked and partially sialylated and contain terminal galactose residues. These initial studies suggest that the PNA-defined glycoprotein, gp200, is a candidate for a nonseminomatous germ cell tumor marker.

Cell Line

Rapid high resolution two-dimensional electrophoresis of human sperm proteins.

An improved protocol has been developed for two-dimensional gel analysis of human sperm proteins through the application of recent technical advances. Advantages of this protocol consist of increased resolving power, reduced processing time, enhanced reproducibility of staining patterns, and applicability to small quantities of protein. Technical improvements include determination of optimal protein loading (20 micrograms/gel), development of a reliable tube gel casting system, and application of minigel technology. In this study over 500 proteins were resolved with molecular weights ranging from 12,000 to 105,000 and isoelectric points from 5.0 to 8.5. This is a three-fold improvement in resolution over earlier results. A single operator was able to generate two-dimensional gels of multiple samples in less than one day. This rapid high resolution technique should facilitate further investigation of human sperm proteins under normal and pathologic conditions.

Electrophoresis, Gel, Two-Dimensional

Influence of testicular carcinoma on ipsilateral spermatogenesis.

A histological review of radical orchiectomy specimens was performed to assess the impact of testicular cancer on spermatogenesis. Slides from 28 patients with testicular cancer were available for review, consisting of 14 pure seminomas, 12 embryonal carcinomas and 2 mixed tumors. For each specimen tubules adjacent (less than 3 mm.) to the tumor and distant (more than 3 mm.) from the tumor were evaluated. This study indicates that marked impairment of ipsilateral spermatogenesis is associated with testicular carcinoma, particularly in the vicinity of the tumor. The quality of distant spermatogenesis appears to be influenced by tumor type and not by elevation of known serum tumor markers, such as human chorionic gonadotropin and alpha-fetoprotein, nor by the presence of carcinoma in situ.

Adult

Protein differences between normal and oligospermic human sperm demonstrated by two-dimensional gel electrophoresis.

Protein expression by sperm obtained from men with normal semen analysis and men with oligospermia were evaluated by two-dimensional gel electrophoresis. Proteins were solubilized in a 9.5 M urea/2% Nonidet-P40 (LKB, Bromma, Sweden) lysis buffer and underwent second dimension separation on 10 to 16% polyacrylamide gradient gels. A set of 36 invariant proteins was identified in all normospermic samples, whereas 8 of 10 evaluable oligospermic samples lacked 1 or more of the invariant proteins. Proteins absent in oligospermic samples may be critical to normal sperm function and may serve as markers for infertility.

Biomarkers

Regional loss of chromosome 6 in two urological malignancies.

Immunogenetic evidence suggests a genetic association between the major histocompatibility complex and the two genitourinary neoplasms, testicular teratocarcinoma and renal cell carcinoma. In order to develop a possible explanation for these findings, we designed a series of experiments to investigate the existence of a tumor suppressor gene in the region of HLA by looking for loss of germ line heterozygosity in these neoplasms at loci within and centromeric to HLA on chromosome 6. Restriction enzyme-digested DNA, from 15 human teratocarcinoma tumors, and corresponding normal somatic DNA, from peripheral blood mononuclear cells, were hybridized to one of three chromosome 6 probes determined to be polymorphic in this region. Probe 4c11 (6p11-cen) revealed loss of germ line DNA in three of 14 tumors. In contrast, probes pC22A (6p21.3) and p308 (6cen), which hybridize to chromosome 6p sequences, telomeric and centromeric to those sequences recognized by 4c11, did not demonstrate loss or sequence alteration in a total of 14 analyzable tumors. A total of 33 renal cell carcinoma specimens was also analyzed with the informative 4c11 probe with loss demonstrated in six of 33 tumors. In contrast, 23 different samples representing 15 other tumor types were examined with 4c11. Loss of chromosome 6p DNA was demonstrated in only two samples. These data support the hypothesis that there is nonrandom loss of DNA centromeric to HLA on chromosome 6 in both testicular teratocarcinoma and renal cell carcinoma.

Blotting, Southern

Aspiration and tetracycline sclerotherapy of hydroceles.

Aspiration and sclerotherapy of hydroceles have been considered an effective outpatient procedure. We report on our experience with modification of this procedure in the treatment of 28 hydroceles. A 10 per cent solution of tetracycline hydrochloride was used as the sclerosant. In this series the mean followup was 15 months and there was an over-all 93 per cent success rate. A single treatment was successful in 75 per cent of the hydroceles. Complications included a hematoma in 2 patients and epididymitis in 1. We consider aspiration and sclerotherapy of hydroceles to be a reasonable alternative to an operation.

Adult

Inhibition of ganglioside sialyltransferase activity and stimulation of neutral glycolipid exocytosis by heparin.

Heparin treatment of human teratocarcinoma cells in culture has several manifestations. Accumulation of gangliosides is greatly decreased while the content of cellular neutral glycolipids is relatively unaffected. However, synthesis of neutral glycolipids is increased and large amounts of these glycolipids are exported out of the cells into the medium. In addition, sialyltransferase activity of heparin-treated teratocarcinoma cells is significantly inhibited, accounting for the decreased cellular content of gangliosides. These studies are not intended to infer any physiological role of heparin in the regulation of glycolipid biosynthesis. However, results do show that beta-D-galactoside 2,3-sialyltransferase is a heparin-binding protein and that inhibition of the enzyme activity by heparin is linked to an alteration in the secretion of most neutral glycolipid precursors and sialyltransferase acceptors. These data suggest that in addition to its biosynthetic function, this ganglioside transferase may play a regulatory role in glycolipid secretion.

Autoradiography

Trophoblastic differentiation of human teratocarcinoma cell line HT-H1.

In culture the human teratocarcinoma cell line HT-H generates both adherent monolayer and free-floating aggregates. Some populations of aggregated cells develop further to form cystic bodies. A previous study showed the morphological resemblance of the cystic bodies to cells of blastocyst of preimplantation embryo. In this study, HT-H adherent cells were further separated into two subpopulations, fast adhering and slow adhering cells. Fast adhering cells produce fibronectin, spread well onto substratum, and do not proliferate. In contrast, slow adhering cells do not produce fibronectin. Trophoblastic markers were examined in each morphological stage of HT-H cells and the following results were obtained. Only fast adhering cells produce progesterone. Human chorionic gonadotropin was secreted preferentially by fast adhering cells, about six times less by slow adhering cells, and was not secreted by aggregates or cystic bodies. All stages of HT-H cells express c-fos but only fast adhering cells express c-fms oncogene. Cytokeratin 18 was expressed in all stages of HT-H cells. The level of cytokeratin 18 is modestly decreased from adherent to aggregates further into cystic bodies. These results indicate that HT-H cells share properties with cells in trophoblast, placenta, and extraembryonic endoderm. Spontaneous differentiation of HT-H cultures results in the appearance of fast adhering cells which exhibit biochemical properties expected for syncytiotrophoblast.

Cell Adhesion

DRw antisera react with activated T cells.

Nylon wool-purified T cells appear to be nonreactive in a lymphocytotoxicity assay with HLA-DRw antisera and complement before cell activation. However, after activation in mixed lymphocyte culture, responder cells express determinants that are strongly reactive with DRw alloantisera after 6 days and gradually disappear by 16 to 18 days. Restimulation of the primed cells resulted in re-expression of the blast determinants. Mitogenic stimulation with Con A or purified PHA (HA-17) also resulted in temporary expression of these determinants; reactivity usually conformed to DRw genetic restriction; however, occasional extra reactions occurred that were variable depending on the method of activation (i.e., MLC, Con A, or HA-17). The results suggest the presence of additional allospecificities within some of the DRw antisera that react with "Ia-like" antigens on activated cells from unique subsets of T cells. Whether these DRw antisera contain antibodies against T cells or agains activation or differentiation T cell antigens is not as yet clear.

Adult

The genetics of PLT response. II. HLA-DRw is a major PLT-stimulating determinant.

PLT response is restricted by the HLA-D region. The present study was undertaken to help define the role of HLA-DRw in PLT restimulation. Haplotype-primed intrafamily PLT cells were made against specificities HLA-DRw1, HLA-DRw3, and HLA-DRw7; each PLT was then restimulated with cells from a 35-member unrelated panel. Restimulation values for each PLT were subjected to bimodal clustering analysis. In addition, blocking experiments were performed with other intrafamily and homozygous typing cell PLT after preincubation with B cell alloantisera. The results show a high correlation (0.881 less than or equal to r less than or equal to 1.00) between the HLA-DRw specificity of the priming haplotype and the HLA-DRw specificity of unrelated panel cells that restimulate in PLT. When stimulating cells were absorbed with the corresponding DRw alloantisera or p29,34 heteroantiserum (against B cell specific antigens), PLT restimulation was significantly blocked. However, the PLT cells treated with antisera showed no effect. The results strongly suggest that HLA-DRw is the principal PLT-stimulating determinant.

Binding, Competitive