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Biomedical subjects

G W Sledge

Publications and source records attributed to G W Sledge.

105 records · Page 6Linked to original sources
PubMed1986

Establishment in long term culture of megakaryocytic leukemia cells (EST-IU) from the marrow of a patient with leukemia and a mediastinal germ cell neoplasm.

Megakaryocytes are the bone marrow cells that generate platelets. They are relatively rare cells, comprising between 0.03 and 0.06% of all nucleated marrow cells (R. L. Berkow et al., J. Lab. Clin. Med., 103: 811-818, 1984). The study of human megakaryocyte differentiation and function has been hampered by the small number of these cells available for study. Recently we have established a human cell line (EST-IU) from the marrow of a patient with an acute nonlymphocytic leukemia and a mediastinal germ cell tumor. While this cell line seems to express many of the phenotypic characteristics of human megakaryocytes, it does not appear to express any phenotypic properties associated with cells of the erythroid, lymphoid, granulocytic, or monocytic lineages. Transmission electron microscopy demonstrates frequent multinucleated cells. Staining for platelet peroxidase reactivity revealed darkening of the perinuclear envelope and the endoplasmic reticulum, a characteristic of cells of the megakaryocytic lineage. Indirect immunofluorescence assays reveal that EST-IU expresses reactivity with anti-platelet glycoprotein antisera, anti-Factor VIII-related antigen antisera, anti-Factor V antisera, anti-thrombocyte antisera, Tab (monoclonal anti-platelet glycoprotein IIb-IIIa), and anti-fibronectin antisera. Flow cytometry-derived DNA histograms demonstrate populations with multiple ploidies, ranging from approximately 4N to 32N. Based upon morphological and histochemical characteristics, antigenic expression, and nuclear characteristics, EST-IU cells appear to have a phenotype that closely resembles human megakaryocytes. This cell line should be useful in the further cell study of the molecular and cell biology of human megakaryocytopoiesis.

Acute Disease↗
PubMed1986

Lactoferrin: affinity purification from human milk and polymorphonuclear neutrophils using monoclonal antibody (II 2C) to human lactoferrin, development of an immunoradiometric assay using II 2C, and myelopoietic regulation and receptor-binding characteristics.

Several investigators have now confirmed our original report demonstrating the myelopoietic suppressive activity of lactoferrin (LF) in vitro. In order to further clarify this activity, we used the recently produced and purified neutralizing antibody (II 2C) to LF to set up an immunoradiometric assay specific for LF and to affinity purify LF from lysates of peripheral blood polymorphonuclear neutrophils (PMN) obtained from healthy donors. Iron-saturated purified PMN LF was as active as iron-saturated affinity purified milk LF as a suppressor of the release of granulocyte-macrophage colony stimulating factors (GM-CSF) from mononuclear human peripheral blood leukocytes. The activities of both the PMN LF and milk LF were inactivated by preincubation with monoclonal anti-LF antibody (II 2C). In order to evaluate the methods of iron saturation of LF in vitro as measures of their functional activities, milk LF was iron saturated by four different methods, including ferric citrate, ferric ammonium sulphate, ferric chloride with nitriloacetate, and ferric chloride alone. The functional characteristics of all four preparations of LF saturated with iron in vitro were relatively equal and were more active than native LF. Resident mouse peritoneal macrophages separated into subpopulations of GM-CSF-producing cells by velocity sedimentation were evaluated for their LF-receptor binding capacity and for sensitivity to the suppression of GM-CSF release by LF. Iron saturated LF suppressed release of GM-CSF from only those fractions containing LF-receptor bearing cells, although not all fractions containing cells bearing receptors for LF responded to the suppressive activity of LF. These studies provide further evidence for the myelopoietic regulatory activity in vitro of PMN-derived LF, which is mediated through populations of mononuclear phagocytes having receptors for LF.

Animals↗
PubMed1986

Monoclonal antibody identification and characterization of a Mr 43,000 membrane glycoprotein associated with human breast cancer.

A monoclonal antibody (323/A3) with a high degree of selectivity for binding to breast cancer cells was produced by immunization of mice with MCF-7 human breast cancer cells. The antigen recognized by 323/A3 on MCF-7 appears to be surface localized, and by enzyme-linked immunosorbent assay, the antibody was found to bind strongly with four of six breast cancer cell lines examined while no binding was detectable with nonbreast cancer cell lines. In vivo distribution of the 323/A3 antigen was screened by immunoperoxidase staining of formalin-fixed paraffin sections of normal human tissues and tumors. Among breast tissues, positive staining was detected with 75% (6 of 8) of metastatic lymph nodes, 59% (76 of 128) of primary breast tumors, 20% (13 of 63) of benign breast lesions, and 0% (0 of 10) of normal breast. No immunostaining was detected with a large variety and number of other normal human tissues with the exception of staining observed with epithelium of normal colon. Antigen distribution appears not to be disease specific, since positive staining was also observed with adenocarcinomas other than breast. The antigen recognized by the 323/A3 antibody was identified by Western blot analysis as a Mr 43,000 protein. The glycoprotein nature of the antigen was demonstrated by its binding to concanavalin A, specific elution with sugar, and immunoprecipitation of a Mr 43,000 radiolabeled protein from extracts of MCF-7 cells after pulse labeling with [3H]glucosamine. The 323/A3 antigen appears to be the same Mr 43,000 protein in cell lines as in breast tumors in vivo. Based on a comparison with the molecular weights of other known tumor-associated antigens and with their immunocytochemical tissue distribution, the Mr 43,000 glycoprotein described here represents a tumor-associated antigen previously undescribed in breast cancer or in other tumors. Since the Mr 43,000 glycoprotein is present on the surface of most breast cancer cells and is either absent or expressed at very low levels in most normal tissues including normal breast, the monoclonal antibody described here may have potential applications in diagnosis and management of breast cancer.

Antibodies, Monoclonal↗
PubMed1986

A new marker of maturation in the cervix: the estrogen-regulated 24K protein.

The presence of an estrogen-regulated protein (24K) in normal, dysplastic, metaplastic, and neoplastic cervical epithelium correlates with histologic criteria for squamous cell maturation. The 24K protein, originally discovered in the MCF-7 breast cancer cell line, was studied in 51 cases by the modified immunoperoxidase Avidin-Biotin Complex method, using an anti-24K mouse monoclonal antibody. Immunostained sections were compared to hematoxylin-and-eosin-stained sections cut from the same tissue block. The 24K protein was observed to be located primarily in the parabasal or "prickle cell layer" of normal cervical tissue (6 of 7 normal cervical tissue specimens tested were positive for 24K protein. Specimens were obtained from surgery for nonneoplastic causes) and in all cases (12 of 12) of dysplasia and carcinoma in situ. Intercellular bridges of these cells showed prominent immunostaining in normal cervix and dysplasia. 24K protein was observed as a granular cytoplasmic stain in all cases of squamous metaplasia (5 of 5) and keratinizing squamous cell carcinoma (9 of 9), and in 8 of 14 cases of nonkeratinizing squamous cell carcinoma. In this latter group, immunostaining was confined to only those cells showing cytoplasmic eosinophilia on H&E sections. In no case was the presence of the 24K protein associated with areas of mature keratin. 24K immunostaining was also observed in the reserve cells of morphologically normal endocervical glands adjacent to areas of dysplasia and carcinoma. We conclude that 24K protein is associated with squamous cell maturation and may be an important marker of reserve cell hyperplasia and squamous metaplasia.

Adult↗
PubMed1986

Monoclonal antibody (II2C) to human lactoferrin inactivates the myelopoietic suppressive effect of human lactoferrin in vitro.

A mouse monoclonal antibody was prepared against purified and fully iron-saturated human breast milk lactoferrin (LF). This antibody was of the IgG1 subclass, and recognized LF biosynthesized in low-density normal human bone marrow cells and LF stored in normal human polymorphonuclear neutrophils. This antibody did not recognize purified and iron-saturated human transferrin. The antibody inactivated the suppressive effects of purified and iron-saturated human milk LF and LF present in crude extracts of normal polymorphonuclear neutrophils against the release of granulocyte-macrophage colony-stimulating factors from mononuclear blood leukocytes in vitro.

Animals↗
PubMed1985

Presence of an estrogen-regulated protein in endometrial cancer.

The presence of an estrogen-regulated protein of Mr 24,000 (24K) was studied in 43 patients diagnosed as having endometrial adenocarcinoma. using an anti-24K monoclonal antibody, a modified immunoperoxidase system (avidinbiotin complex) was used to detect the presence of 24K in formalin-fixed, paraffin-embedded tissue samples. The positivity for 24K was correlated with low tumor histologic grade, few mitotic figures, few nucleoli, and a low degree of nuclear pleomorphism. These data suggest that 24K may be a potential marker of tumor differentiation.

Adenocarcinoma↗
PubMed1984

Phase II trial of vindesine in patients with squamous cell cancer of the head and neck.

Fifteen patients with advanced squamous cell cancer of the head and neck received weekly vindesine at doses of 3 mg/m2. No patient had received prior chemotherapy, though all had received either radiotherapy or radiotherapy and surgery. Fourteen patients were evaluable for response. Two patients had documented partial remissions. Dose-limiting neutropenia was the primary toxic effect observed. It was frequent and occasionally life-threatening. Vindesine has minor but real activity in this group of patients with advanced head and neck cancer who have not received prior chemotherapy.

Aged↗
PubMed1983

Monoclonal antibody storage conditions, and concentration effects on immunohistochemical specificity.

Monoclonal antibodies against a 24,000 dalton intracellular estrogen-regulated protein in human breast cancer cells were used to study storage conditions and the effects of monoclonal antibody concentrations on immunohistochemical antigen localization. Both hybridoma supernatants and ascites fluid obtained from mice injected with hybridoma cells were used as sources of monoclonal antibodies; the monoclonal antibodies in the ascites fluid were concentrated and purified. Both antibody preparations were stored at 4, -20, or -70 degrees C and periodically tested for activity at these storage conditions. There was no difference in activity for the antibodies between storage at -20 and -70 degrees C. However, when highly diluted antibody was stored at 4 degrees C, the activity was lost within 2 weeks if carrier proteins were not added. These monoclonal antibodies were applied to immunohistochemical staining of different mouse and human tissues processed for routine paraffin sections, using the avidin-biotin-peroxidase procedure. A monoclonal antibody of unrelated specificity was used as control. When these antibodies were used at high concentrations, all the different tissues examined were immunostained. With reduction of the antibody concentration, an immunohistochemical dissection of the tissues was seen until specific immunostaining was reached. When even more highly diluted monoclonal antibody was used, heterogeneity in the staining pattern became very high. On the basis of these results, certain immunohistochemical criteria are proposed for the selection of the optimum concentration of monoclonal antibodies for specific antigen detection.

Animals↗
PubMedDate not supplied

High-dose chemotherapy in breast cancer -- the perils of history uncontrolled.

Breast cancer remains a common and devastating disease that affects approximately 180,000 women and results in more than 43,000 deaths annually in the United States. Although only 10% of patients have overt metastatic disease at the time of diagnosis, as many as one third of those who present with lymph node-negative disease and half of those who present with lymph node-positive disease eventually develop metastatic breast cancer. With few exceptions, metastatic breast cancer is largely incurable, and the median duration of survival remains 18 to 24 months. Over the past 3 decades, both laboratory and clinical efforts to increase survival have focused on dose intensity in chemotherapy regimens.

Antineoplastic Agents↗