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Biomedical subjects

W Biddle

Publications and source records attributed to W Biddle.

17 recordsLinked to original sources
PubMed1997

Animal serum-free culture of purified human CD34+ cells: amplification of progenitors from G-CSF and GM-CSF-mobilized peripheral blood.

The isolation and culture of human CD34+ cells could have broad clinical application for hematologic support following high-dose chemotherapy or bone marrow transplantation. The need for reproducible, animal product-free conditions for the culture of progenitors is crucial to the widespread clinical implementation of ex vivo cell therapies. In these studies, we explored the use of animal serum-free (ASF) medium for the culture of isolated human bone marrow and peripheral blood CD34+ cells. In this ASF system, isolated CD34+ cells were cultured using a variety of different growth factor combinations. Such ASF culture conditions yielded equivalent to superior cell and progenitor growth when directly compared with culture containing 10% fetal calf serum (FCS). In cultures containing IL-1, IL-3, and stem cell factor, total cell numbers increased, on average, 33-fold over the first 2 weeks. On phenotypic analysis, the ASF cultures demonstrated sustained proliferation of CD33+ myeloid cells throughout the culture period. CD34+ cell numbers increased during the first 7-10 days of culture, with a mean 3.4-fold expansion. Concomitant with the CD34+ cell expansion was an average 8.2-fold expansion of colony-forming unit-granulocyte-macrophage (CFU-GM) and a 102.0-fold increase in burst-forming units-erythrocytes (BFU-E). Likewise, a mean 4929-fold expansion of CD41a+ megakaryocyte progenitors was observed in these CD34+ cultures. Different combinations of growth factors affected the fold increase in cell and progenitor number. When CD34+ cell cultures from normal healthy volunteers mobilized with either G-CSF or GM-CSF were compared, similar expansions of total cell and progenitor cells resulted. However, CD41+ cells expansions were greater in those samples from G-CSF-mobilized volunteers in every case tested. These studies established the feasibility of this ASF CD34+ cell culture system to generate a population of maturing progenitors for potential use in transfusion support during cytopenic periods following high-dose chemotherapy or bone marrow transplantation.

Animals↗
PubMed1994

Rapid isolation and serum-free expansion of human CD34+ cells.

Human CD34+ cells were isolated from bone marrow from normal volunteers and expanded under serum-free culture conditions. CD34+ cells were cultured with interleukin-3 (IL-3), IL-1, and stem cell factor and expanded in granulocyte-macrophage colony-forming units, erythroid blast-forming units, and CD34+ cell number during the first 7-14 days of incubation. By contrast, cultures maintained in fetal calf serum under identical conditions showed much reduced expansion, as measured by all of the above parameters. The level of expansion of the CD34+ cells was dependent on the combination of growth factors used during culture. The data establish the feasibility of serum-free expansion of progenitors and suggest the clinical use of this procedure for the generation of expanded progenitor cell products for transfusion after chemotherapy to minimize treatment-related cytopenias.

Adult↗
PubMed1992

Colonic mucosal mast cell distribution at line of demarcation of active ulcerative colitis.

We examined the distribution of colonic mucosal mast cells in 25 patients with active ulcerative colitis, with a clear line of demarcation separating active inflammation from normal mucosa. Biopsies, at least one adjacent to the line of demarcation, one in inflamed mucosa, and one above were obtained during colonoscopy. Eight patients had elevated mast cells throughout the colon, and 12 had increased numbers at the line of demarcation of disease. Mean numbers of mast cells from these patients were 6.3 (+/- 2.1 SD) in active inflammation, 19.5 (+/- 7.1 SD) at the line of demarcation, and 15.8 (+/- 8.4 SD) in normal mucosa. Histologic inflammation decreased as mast cells increased. The accumulation of mast cells at the visible line of demarcation between normal and abnormal mucosa suggests mast cells play a critical role in either accelerating the process of inflammation or in suppressing continued extension of the disease.

Adult↗
PubMed1991

An introduction to research: a primer for the nurse anesthetist.

The goals of this article are to provide an overview of the research process and highlight some of the most important aspects. In the process, the definition of research and some general terminology will be reviewed. Discussions of how to define a problem, reviewing the literature, types of study designs, sampling, types of measurement, reliability and validity, limitations and assumptions, data analysis, ethical concerns with human subjects, and time management are included, as are examples of published research.

Data Collection↗
PubMed1990

Murine monoclonal anti-idiotype antibody as a potential network antigen for human carcinoembryonic antigen.

Carcinomas of the gastrointestinal tract are not curable by standard therapies. Thus, new therapeutic approaches for this disease are needed. This study proposes the use of anti-Id mAb as Ag substitutes to induce anti-tumor immunity in gastrointestinal cancer patients. Recently, we have generated and characterized one monoclonal anti-Id antibody, designated 3H1 (Ab2), which mimics biologically and antigenically a distinct and specific epitope of the 180,000 m.w. carcinoembryonic antigen (CEA) primarily expressed in high density by human pancreatic and colonic tumor cells. This epitope is unique to CEA and not present on other CEA-related lower m.w. members of the Ag family also found on normal tissues. The antigenic determinant as defined by the mAb 8019 (Ab1) against which the Ab2, 3H1 was raised, is absent on normal adult tissues by immunoperoxidase staining and haematopoietic cells including granulocytes by flow cytometry analysis. Anti-Id (Ab2) 3H1 induced CEA-specific antibodies in mice and rabbits. The immune sera from both mice and rabbits competed with Ab1 for binding to the colon carcinoma cell line LS174T and inhibited the binding of radioiodinated Ab1 to Ab2. This indicates that anti-anti-Id (Ab3) in mice and rabbits share idiotopes with Ab1 (8019). Furthermore, monoclonal Ab3 that bind to CEA have been generated from mice immunized with 3H1. The Ab3 (both polyclonal as well as monoclonal) immunoprecipitated the same 180,000 m.w. CEA as Ab1 (8019) by Western blotting analysis and showed almost identical immuno-staining patterns as Ab1 on colonic adenocarcinoma tissue sections from several patients. Collectively these data suggest that Ab2 3H1 could potentially be used clinically as a network Ag for immunotherapy of patients with CEA positive tumors.

Adenocarcinoma↗
PubMed1990

Interferon gamma augments Lym-1-dependent, granulocyte-mediated tumor cell lysis.

Lym-1 is a therapeutically promising IgG2a monoclonal antibody (MoAb) that reacts with variant class II molecules expressed on B-lineage malignancies. To optimize antitumor immunotherapy with Lym-1, we determined whether granulocytes could participate in tumor lysis mediated by Lym-1 and whether recombinant interferon gamma (IFN-gamma) could influence this reaction. Granulocytes had minimal activity in mediating Lym-1 antibody-dependent cellular cytotoxicity (ADCC) compared with peripheral blood mononuclear cells (PBMC). However, IFN-gamma markedly augmented and occasionally induced granulocyte Lym-1 ADCC in a dose-dependent fashion (optimal 100 U/mL). Granulocytes primed with IFN-gamma for 24 hours displayed greatly increased ADCC in the absence of further IFN-gamma exposure. In most individuals, IFN-gamma also enhanced PBMC Lym-1 ADCC. Interferon alfa (IFN-alpha), although able to enhance PBMC-mediated Lym-1 ADCC and non-ADCC lysis, had no effect on granulocyte activity. Lym-1 ADCC involved an interaction between Fc receptor-bearing granulocytes and Lym-1 antigen positive targets based on the following: (1) The reaction was Lym-1 dose-dependent with cytotoxicity detectable at concentrations as low as 0.5 microgram/mL. (2) An irrelevant, isotype-matched MoAb (UPC-10) was unable to mediate ADCC. (3) In the absence of Lym-1, granulocytes--with or without IFN-gamma--displayed no intrinsic tumor lytic ability. Conversely, without granulocytes, Lym-1 or Lym-1 plus IFN-gamma had no effect. (4) Protein A, which binds avidly to Lym-1, inhibited the reaction 95%. (5) IFN-gamma induced granulocyte expression of CD64, the IgG Fc receptor that binds murine IgG2a MoAbs. (6) Of nine malignant human cell lines, only the three that moderately or strongly expressed the Lym-1 antigen were consistently lysed. Preclinical studies such as these may provide a rational basis for designing clinical trials with Lym-1 in combination with IFN-gamma.

Antibodies, Monoclonal↗
PubMed1990

Survey results: identification of research interests and needs in SGNA.

The purpose of this study was to determine the interest level and needs of the Society of Gastroenterology Nurses and Associates (SGNA) to develop a research program for (SGNA), whose members care for patients with gastrointestinal (GI) problems. A questionnaire mailed to all members (3500) focused on their research interest and experience, and 358 questionnaires were returned (return rate 10%). Data were analyzed with descriptive statistics, analysis of variance, and content analysis. Educational levels were: 8% LPN, 32% RN, 16% AD, 31% BA/BS, 9% MA/MS. Sixty-seven percent were employed in GI endoscopy laboratories. Approximately 35% had some type of research experience. The mean level of interest in research, rated on a scale of 0 (none) to 10 (high), was 6.6 (+/- 2.3). There was a significant difference between education and interest levels (RN and AD mean = 6.2, MS and "other" mean = 7.6). Moderate interest was expressed for all aspects of research (data collection--highest; finding funding--lowest). Two commonly expressed needs were for information about current GI research and how to begin the research process. The most frequently cited clinical problems needing study were infection control, staffing, and intra-procedure medication use and monitoring. This study demonstrated an interest in research among GI nurses of varied educational backgrounds and experience. Nurses in practice have observed many areas of concern and recognize the value of research to contribute to the improvement of their practice.

Gastrointestinal Diseases↗
PubMed1990

Cellular origin and induction of pregnancy-associated alpha 2-glycoprotein synthesis in pregnant rats.

The synthesis of alpha 2-PAG was measured and compared in tissues and cells from normal non-pregnant females, and maternal and fetal rats in vitro to define the target cells hormonally regulated during pregnancy. Synthesis was measured by [L-14C]leucine incorporation into immunochemically isolated alpha 2-PAG and confirmed by radioimmunodiffusion. alpha 2-PAG synthesis was demonstrated in maternal peripheral blood leucocytes, placenta, breast, spleen, liver and fetal peripheral blood leucocytes and liver. Maternal and fetal liver were the most active tissue producers and fetal liver synthesized 4 times more alpha 2-PAG than did maternal liver. Furthermore, fetal peripheral blood leucocytes synthesized 2 times more alpha 2-PAG per cell than did these same maternal cells. A direct comparison of synthesis by cells from pregnant and non-pregnant female rats revealed that (1) maternal peripheral blood leucocytes synthesized 5 times more alpha 2-PAG per cell than did normal leucocytes, although these same cells synthesized approximately equal amounts of total cell protein per cell, (2) maternal peritoneal exudate macrophages also synthesized 5 times more alpha 2-PAG per cell than did macrophages obtained from normal female rats, and total protein synthesis by these cells also closely paralleled each other, (3) maternal and fetal plastic-adherent peripheral blood monocytes synthesized 22 and 58 times more alpha 2-PAG per cell respectively than did normal monocytes, (4) maternal and fetal non-adherent lymphocytes synthesized 8 and 16 times more alpha 2-PAG per cell respectively than did normal lymphocytes and (5) fetal monocytes and lymphocytes synthesized 3 and 2 times more alpha 2-PAG per cell than did maternal monocytes and lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

A beginner's guide to research.

The purpose of this article is to provide an overview of the research process and highlight some of the most important aspects. The definition of research and some general terminology are reviewed. Included in this article are discussions of the following: defining a problem, reviewing the literature, types of study designs, sampling, types of measurement, reliability and validity, limitations and assumptions, data analysis, ethical concerns with human subjects, and time management. Examples of published research are used to illustrate the points where necessary. A supplemental bibliography is provided to direct the interested reader to more in-depth discussions of the various aspects of the research process.

Data Interpretation, Statistical↗
PubMed1987

Specific cytoplasmic alpha-fetoprotein binding protein in MCF-7 human breast cancer cells and primary breast cancer tissue.

Direct evidence was obtained for the existence of a specific high affinity alpha-fetoprotein (AFP)-binding protein in the cytosol of both MCF-7 human breast cancer cultured cells and primary breast cancer tissue from postmenopausal women using a nitrocellulose blotting assay. Scatchard analysis of the binding data for MCF-7 cells at 37 degrees C revealed the presence of a single class of AFP binding sites with an apparent Kd of 4.5 x 10(-8) M, and 75,000 binding sites per cell. All 9 primary breast cancer cytosols obtained from postmenopausal women also contained measureable levels of this specific AFP-binding protein. The number of AFP molecules specifically bound varied considerably between patients and ranged from 29-250 fmol per mg cytosol protein. Levels of AFP-binding protein levels and estrogen receptor measured in these same breast cancer cytosols showed a positive statistical correlation (r = 0.85). Taken together, the present evidence for the existence of a specific cytoplasmic AFP-binding protein in MCF-7 cells and previously reported evidence for de novo synthesis of free immunoreactive and bound nonimmunoreactive forms of cytoplasmic AFP by MCF-7 cells is consistent with the conclusion that most of the endogenous AFP synthesized in breast cancer cells is rapidly bound to specific cytoplasmic AFP-receptors, and that binding of AFP to these receptors masks its immunoreactivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Neoplasms↗
PubMed1987

Elevated serum alpha fetoprotein levels in postmenopausal women with primary breast carcinoma.

Elevated serum alpha fetoprotein (AFP) levels were detected and measured by a RIA in postmenopausal women with primary breast carcinoma. This increased AFP consisted of both free and total AFP measured before and after treatment of serum with 0.4 M KCl. The difference between free and total serum AFP in breast cancer patients was 44 IU ml-1. We conclude that serum from breast cancer patients contains appreciable amounts of previously undetected, initially nonimmunoreactive, AFP which became immunoreactive and measurable after KCl treatment. Previous reports indicating the presence of free and nonimmunoreactive AFP in primary breast cancer tissue cytosol and synthesis of these AFP components by MCF-7 cultured human breast cancer cells supports the conclusion that elevated serum AFP measured in breast cancer patients originates from the breast cancer cells. The conclusion that AFP is a breast tumour marker protein suggests that: (1) serial serum AFP measurements in breast cancer patients may provide useful diagnostic and prognostic information in individual cases and (2) a similar nonimmunoreactive serum AFP may be detected in patients with other types of cancer not currently known to be associated with AFP.

Biomarkers, Tumor↗
PubMed1984

Potentiation of the cell growth inhibitory effect of beta interferon by mopidamole.

It was suggested that the antitumor effect of the interferons is based in part on their ability to stimulate increased cAMP production. We have explored the interaction of human fibroblastic beta interferon (HFIF) with a cAMP decomposition inhibitory pyrimido-pyrimidine derivative, Mopidamole (RA-233) in cultures of neoplastic and normal cell lines. Mopidamole potentiated the growth inhibitory effect of HFIF in cultures of ES-1 malignant melanoma cells, LNCaP prostatic carcinoma cells, RT-4 transitional carcinoma cells, HT-29 colon adenocarcinoma cells and in diploid fibroblast cells.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1984

Antineoplastic effect of the xanthine derivative Trental.

The xanthine derivative, Trental (pentoxifylline) was found to inhibit several human leukemic and lymphoma cell lines in tissue cultures. Optimal concentrations were less inhibitory for a normal B-lymphocyte cell line then for the neoplastic cell lines. In fact, small concentrations stimulated DNA synthesis in the normal cell line. Trental and beta-interferon appeared to be additive synergists at certain dosages. Possible mechanisms are discussed.

B-Lymphocytes↗
PubMed1984

Antineoplastic effect of the pyrimido-pyrimidine derivative: RA 233.

A number of normal and neoplastic human cell lines in culture were studied by cell count and 3H thymidine incorporation for growth inhibitory effect by the pyrimido-pyrimidine derivative RA-233 (mopidamole). There was more inhibition when the drug was added to the culture in the lag phase than in the logarithmic growth phase. There was more inhibition (particularly at low doses) of the neoplastic cell lines than of the non-neoplastic cell lines.

Antineoplastic Agents↗
PubMedDate not supplied

Growth of NS0 cells in protein-free, chemically defined medium.

Many hybridoma and recombinant myeloma cell lines have been successfully adapted to growth in protein-free media. Compared with serum-supplemented media, use of protein-free media promotes superior cell growth and protein expression and facilitates downstream purification of the expressed product. Owing to its sterol auxotrophy, the NS0 myeloma is normally grown in either a serum-supplemented medium or a serum-free medium supplemented with an animal-derived lipoprotein. CD Hybridoma Medium (a protein-free, chemically defined formulation) grows many cell lines that do not exhibit lipid dependence, but this medium does not support growth of NS0 cells without further lipid supplementation. We tested several commercially available lipid supplements in CD Hybridoma Medium, including bovine EX-CYTE VLE. None of the tested supplements supported long-term growth of NS0 cells in CD Hybridoma Medium. Sustained long-term growth of NS0 cells was achieved in CD Hybridoma Medium supplemented with various animal- or plant-derived lipids complexed with cyclodextrin. NS0 cells adapted to CD Hybridoma Medium supplemented with cyclodextrin-lipid complex reached peak cell densities that were more than double those observed in serum-supplemented medium and were cultured for more than 15 passages. These cultures were also successfully cryopreserved and recovered in this defined medium. Through the use of cyclodextrin-based additives to CD Hybridoma Medium, it is possible to solubilize significant quantities of sterols and other lipids and to maintain a protein-free, chemically defined cultivation environment for NS0 cells. The culture system can be kept entirely free of animal-derived components if the supplement is made with plant-derived or synthetic lipids.

Cell Division↗