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Biomedical subjects

W C DeWolf

Publications and source records attributed to W C DeWolf.

At least 37 records · Page 2Linked to original sources
PubMed1995

Distinct glycoforms of a tumor specific glycoprotein, gp200, in human testis and testicular tumors.

We recently purified a 200 kD peanut agglutinin-binding glycoprotein from the embryonal carcinoma cell line HT-E (833K) that is expressed selectively in nonseminomatous germ cell tumors. We now further characterize gp200 using Western blot analysis to compare normal and malignant testicular germ cells for reactivity to peanut agglutinin, a plant lectin that recognizes terminal D-galactosyl residues, and GCTM-2, a monoclonal antibody that recognizes a 200 kD keratan-sulfate proteoglycan on human embryonal carcinoma. The results indicate that normal germ cells express gp200 as a membrane-bound 230 kD glycoform that expresses terminal galactose residues. This 230 kD glycoprotein is absent on spermatozoa but present on seminomatous germ cell tumors and somatic tissue and does not express terminal galactose on its carbohydrate side chains. In contrast, nonseminomatous germ cell tumors express a heavily sialylated glycoform of gp200 that does express terminal galactose residues. These results describe a glycoprotein that exists in several glycoforms in normal and malignant testicular germ cells. The differential expression of these glycoforms may help in understanding the ontogeny of germ cell tumors.

Blotting, Western↗
PubMed1995

Bacillus Calmette-Guérin immunotherapy for superficial bladder cancer. New prospects for an old warhorse.

The use of live M. bovis BCG to treat superficial bladder cancer has endured its seemingly anachronistic origin in the early days of tumor immunology to emerge as the therapy of choice for superficial bladder cancer. Its superiority over conventional intravesical therapy has been established for tumor prophylaxis and treatment of residual disease and CIS, providing long-term results that have translated into improvements in disease progression and survival. Although its exact mechanism of action remains elusive, extensive studies suggest that this intracellular pathogen stimulates the immune system to produce powerful cytokine mediators and effector cells that act locally to destroy bladder tumors. Although unique toxicities occur by virtue of BCG's use as a live vaccine, this same liability has opened the door for new opportunities through the use of recombinant DNA technology. Exciting prospects include the use of BCG as a cytokine carrier and as a tumor antigen depot. Genetic engineering may also yield varients that are both intrinsically safer and more specific in bladder tumor targeting.

BCG Vaccine↗
PubMed1994

The effect of testicular nongerm cell tumors on local spermatogenesis.

OBJECTIVE: To assess ipsilateral spermatogenesis in men with malignant and benign nongerm cell tumors of the testis. DESIGN, PATIENTS: Histologic review of radical orchiectomy specimens performed for 20 men with malignant nongerm cell tumors and 15 with benign testicular lesions, including five Leydig cell tumors with benign clinical features. MAIN OUTCOME MEASURES: Degree of spermatogenesis was determined on a 1 to 10 scale, with 10 representing mature sperm within a seminiferous tubule. For each patient "near" and "far" scores were determined by obtaining the mean score of 50 tubules adjacent (< 3 mm) to the tumor and 50 tubules distant (> 3 mm) from the tumor, respectively. RESULTS: Total, near, and far scores were all lower for malignant tumors than for benign lesions. Scores for Leydig cell tumors were similar to benign lesions. Malignant tumors demonstrated a gradient effect, with greatest impairment of spermatogenesis occurring adjacent to tumor. In contrast, a distinction between near and far scores was not observed for benign lesions or Leydig cell tumors. CONCLUSIONS: Malignant nongerm cell tumors of the testis were associated with significant impairment of ipsilateral spermatogenesis, particularly in areas adjacent to tumor. These findings are similar to those observed for testicular germ cell tumors, suggesting a generalized negative influence on ipsilateral spermatogenesis by malignant tumors.

Adult↗
PubMed1994

Recombinant Mycobacterium bovis BCG secreting functional interleukin-2 enhances gamma interferon production by splenocytes.

Mycobacterium bovis BCG was genetically engineered to express and secrete mouse interleukin-2 (IL-2) and rat IL-2. Genes encoding IL-2 were inserted into an Escherichia coli-BCG shuttle plasmid under the control of the BCG HSP60 promoter. To facilitate study of proteins produced in this system, the IL-2 gene product was expressed (i) alone, (ii) with the mycobacterial alpha-antigen secretion signal sequence at the amino terminus, (iii) with an influenza virus hemagglutinin epitope tag at the amino terminus, and (iv) with both the secretion signal sequence and the epitope tag. When expressed with the alpha-antigen signal sequence, biologically active IL-2 was secreted into the extracellular medium. Western blot (immunoblot) analysis of the intracellular IL-2 and extracellular IL-2 revealed that the secretion signal was appropriately cleaved from the recombinant lymphokine upon secretion. To assess the ability of recombinant BCG to stimulate cytokine production in a splenocyte population, mouse splenocytes were cultured together with wild-type or IL-2-producing BCG. IL-2-secreting BCG clones stimulated substantial increases in gamma interferon production, which could be reproduced by the addition of exogenous IL-2 to BCG. Levels of IL-6, IL-10, tumor necrosis factor alpha, and granulocyte-macrophage colony-stimulating factor were not significantly changed, while IL-4 and IL-5 remained undetectable (less than 50 pg/ml). The enhanced production of gamma interferon in response to IL-2-secreting BCG was strain independent. Recombinant BCG expressing mammalian cytokines provides a novel means to deliver cytokines and may augment the immunostimulatory properties of BCG in immunization and cancer therapy.

Animals↗
PubMed1993

Candida epididymitis: newly recognized opportunistic epididymal infection.

Epididymitis is common, yet it is rarely associated with fungal pathogens. We report a case of Candida albicans epididymitis in a diabetic which was ultimately treated by orchiectomy. Opportunistic infections of the genitourinary tract in immunosuppressed patients are becoming more prevalent; examples include fungal infections in patients with acquired immune deficiency syndrome or after organ transplant. The fact that opportunistic organisms can invade the epididymis and produce infection suggests that in cases of persistent epididymitis, which have failed to respond to conventional therapy, more aggressive diagnostic procedures should be considered. Needle aspiration with cultures for fungus and viral organisms should be performed. This is especially true in patients with preexisting chronic illness or an immune compromised state.

Aged↗
PubMed1993

A self-expanding prostatic stent for bladder outlet obstruction in high risk patients.

We describe the clinical experience with a self-expanding prostatic stent used in patients with bladder outlet obstruction and advanced comorbid medical illness. A Gianturco-Z stent was placed in 25 men, including 21 in urinary retention. Patients were followed clinically and with serial endoscopy. Mean age was 80.5 years (range 54 to 98). Mean followup was 10.1 months, with a longest followup of 24 months. Spontaneous voiding resumed in 20 of 21 patients (95%) with retention, with 16 of 21 (76%) demonstrating long-term success. Two patients failed due to stent migration within 1 month. Other complications were limited to minor stent incrustations in 2 cases, symptomatic urinary infections without fever in 2 and epididymitis occurring 15 months following stent placement in 1. No perioperative cardiovascular complications were encountered. Followup endoscopy revealed partial stent coverage by urothelium in 13 of 16 men at 1 month and greater than 90% coverage in 8 of 13 by 3 months. The high success rate with minimal morbidity observed suggests that prostatic stents may become the first-line therapy for the medically compromised man with bladder outlet obstruction.

Aged↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1990

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↗
PubMed1989

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↗
PubMed1988

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↗
PubMed1987

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↗
PubMed1986

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↗