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Biomedical subjects

M Relf

Publications and source records attributed to M Relf.

9 recordsLinked to original sources
PubMed1997

Expression of the angiogenic factors vascular endothelial cell growth factor, acidic and basic fibroblast growth factor, tumor growth factor beta-1, platelet-derived endothelial cell growth factor, placenta growth factor, and pleiotrophin in human primary breast cancer and its relation to angiogenesis.

Angiogenesis is a significant prognostic factor in breast cancer, but the factors that control angiogenesis in vivo are not well defined. Multiple angiogenic polypeptides are known, and we have determined the expression of seven of these in primary human breast cancers; the relationship of expression to estrogen receptor and vascular density was also examined. Vascular endothelial growth factor (VEGF) and its four isoforms (121, 165, 189, and 206 amino acids), transforming growth factor (TGF)-beta1, pleiotrophin, acidic and basic fibroblast growth factor (FGF), placental growth factor, and thymidine phosphorylase (platelet-derived endothelial cell growth factor) were quantitated by RNase protection analysis. beta-FGF was also measured by ELISA. The estrogen receptor (ER), epidermal growth factor receptor, and vascular density were analyzed in 64 primary breast cancers. All tumors expressed at least six different vascular growth factors. VEGF was most abundant, and the transcript for the 121-amino acid form predominated. Other angiogenic factors expressed at high levels were thymidine phosphorylase and TGF-beta1. Expression of most of the angiogenic factors did not correlate with that of ER or vascular density. However, thymidine phosphorylase did, with a correlation coefficient of 0.3 (P = 0.03). There were significant associations of pleiotrophin with acidic FGF expression (P = 0.001) and TGF-beta with platelet-derived endothelial cell growth factor expression (P = 0.001). Thus, angiogenesis may involve a coordinate regulation of some vascular growth factors. High VEGF expression correlated with poor prognosis in univariate analysis (P = 0.03), as did ER and epidermal growth factor receptor expression. Basic FGF was also assessed by ELISA and was more highly expressed in tumors than normal breast tissues (median, 346 microg/ml cytosol; range, 54-1323 versus median, 149; range, 32-509; P = 0.01). Implications for therapy are that broad spectrum agents that block features common to these factors may be useful (e.g., antagonism of heparin-binding activity agents), because so many angiogenic factors are expressed. Inhibiting endothelial migration or agents directly toxic to endothelium would be of value in a combined approach to therapy.

Breast Neoplasms↗
PubMed1996

A cytokine profile of normal and malignant ovary.

We defined a cytokine mRNA profile of 12 ovarian cancer biopsies, 10 normal/benign biopsies, six ovarian cancer cell lines and three ovarian cancer xenografts, using RT-PCR. The profile, based on screening for 25 cytokines and 12 receptor mRNAs, was rich in growth factors, pro-inflammatory cytokines and chemokines, but weak in lymphocyte-associated cytokines. The pattern was unique to ovarian tissue, but similar in normal, benign and malignant biopsies, with > 80% samples expressing 16 cytokines in common. Fourteen of these were also expressed by > 65% cell lines, but fewer were detected in xenografts. Potential autocrine loops existed for IL-1, IGF-1, M-CSF, GM-CSF and TNF-alpha. IL-4 and IFN-gamma receptors were expressed in absence of ligand. Chemokines RANTES, MIP-1 alpha and MIP-1 beta were expressed in biopsies, but were rarely detected in cell lines and absent from xenografts. IGF-1 and its receptor was expressed in every sample, as was IFN-gamma receptor. Another 10 cytokine mRNAs and six receptors were expressed in > 80% samples. These may contribute to key survival/growth loops. Similarities between normal and malignant biopsies suggest that analogous processes of remodelling and repair occur. RT-PCR proved a rapid, reproducible screen, but further assays are required to detect quantitative differences between normal and malignant tissues and tumour models.

Animals↗
PubMed1995

Increasing job satisfaction and motivation while reducing nursing turnover through the implementation of shared governance.

In today's cost-conscious, changing health care environment, health care agencies must identify and implement strategies to promote fiscal responsibility while maintaining employee satisfaction and retention. The cost to recruit professional nurses is high. Therefore, the business objective is to retain the productive employee. Through the implementation of shared governance, employees find the workplace rewarding and stimulating--motivating factors as described by Herzberg. The Secretary's Commission on Nursing identified 16 strategies for the reduction of the nursing shortage and retention of professional nurses. One recommendation reinforces a report by the American Academy of Nursing that states work satisfaction among nurses in higher and turnover rates lower when organizational climates provide for nursing's involvement in decision making relating not only to nursing practice and unit management but also patient care. Through shared governance, staff nurse involvement in nursing and patient care policy is advanced.

Humans↗
PubMed1994

Gene therapy through signal transduction pathways and angiogenic growth factors as therapeutic targets in breast cancer.

Angiogenesis is a major new prognostic factor in breast cancer. Small vessels quantitatively assessed by staining with anti-CD31 antibodies correlate with lymph node involvement and are a better independent predictor of survival. There are many vascular growth factors, but predominant in primary tumors assessed by nuclease protection assays are vascular endothelial growth factor and platelet-derived endothelial cell growth factor. Acidic and basic fibroblast growth factor are also detectable. A common feature of these angiogenic factors is heparin binding, so novel analogues of suramin that can compete for heparin binding have been developed. These are more potent in vitro against endothelial cells and are less toxic in vivo, thereby giving a much better therapeutic ratio. Protein kinase C is also important in endothelial growth, as it is in carcinoma growth. Thus, a novel agent inhibiting this pathway, and inducing transforming growth factor-beta production has been assessed in a Phase I trial; this agent is bryostatin. It does not cause marrow suppression and has stimulatory effects of tumor necrosis factor-alpha and interleukin (IL)-6 production. High expression of epidermal growth factor (EGF) receptors and erbB-2 has been related to poor prognosis. EGF receptors are mainly regulated by transcription, as are some cases of high erbB-2 expression. Thus, a novel approach to gene therapy is being developed using direct tumor injection of cDNA, with a tumor specific promoter ligated to the IL-2 gene. This avoids many problems associated with targeting. Because IL-2 stimulation of cytotoxic T-cells will depend on appropriate antigen presentation, human lymphocyte antigen Class I expression was studied, as was the peptide transporter system RING4 (TAP1). Losses were found in 50% of cases, and in some cases only in lymph nodes but not primary cancers, thereby providing evidence for a role in suppressing metastasis. Thus, many new approaches to therapy are possible as a result of understanding growth factors and intracellular signaling pathways.

Angiogenesis Inducing Agents↗
PubMed1994

The assessment of need for bereavement follow-up in palliative and hospice care.

This paper describes a postal survey of palliative care services and teams which were identified in the 1992 Directory of Hospice Services in the UK and Ireland. Its aims were to investigate how units assess the need for bereavement follow-up, and to determine the nature and extent of services provided for bereaved adults. We sent out 397 questionnaires, of which 187 were returned, a response rate of 47%. Results indicate that 156 respondents (84%) provided follow-up and a further 13 (7%) were planning bereavement services. Only 48 (25%) units undertook formal standardized risk assessment procedures to allocate appropriate services; in 41 units (85%) this was done by a nurse. Of the remaining 125 units, 58 (46%) reported basing their decisions on clinical impressions. Content analysis of the formal assessment instruments revealed 39 subcategories, which were broadly grouped into three areas: circumstantial factors at or near to the time of death, personal factors and social factors. Recommendations are made for further study.

Bereavement↗
PubMed1992

Rickets--a complication of ifosfamide chemotherapy for Wilms tumor.

Recent reports of metabolic bone disease occurring as a result of drug induced Fanconi syndrome due to ifosfamide have appeared in the pediatric literature. Ifosfamide is a chemotherapeutic agent used for treatment of pediatric solid tumors. We present an additional case of ifosfamide induced rickets, the first in the radiologic literature.

Child, Preschool↗
PubMed1988

Evaluation of four CD22 antibodies as ricin A chain-containing immunotoxins for the in vivo therapy of human B-cell leukemias and lymphomas.

Ricin A chain-containing immunotoxins (IT-As) specific for the human B-cell antigen, CD22, were prepared from 4 monoclonal antibodies (MAbs) or their Fab' fragments: RFB4, HD6, UV22-I and UV22-2. The ITs were tested for their ability to kill cells from the Burkitt lymphoma line, Daudi, the pre-B-cell leukemia line, NALM-6, and the myeloma cell line, ARH-77. Daudi expresses high levels of CD22, whereas NALM-6 and ARH-77 express low levels of CD22. The IgG-RFB4-A was highly toxic to all 3 cell lines; it killed 50% of the Daudi cells at a concentration of 1.2 x 10(-12) M and 50% of NALM-6 and ARH-77 cells at concentrations of 1.5 to 2.1 x 10(-11) M. IgG-RFB4-A was 10-30 times more toxic to Daudi cells than were the IgG-As constructed from the other 3 CD22 MAbs and 10 times more toxic than ricin itself. IT-As constructed from the Fab' fragments of the 4 CD22 antibodies were 2 to 5 times less toxic to Daudi cells than their IgG-A counterparts. Fab'-RFB4-A was twice as toxic to Daudi cells as ricin, whereas the other Fab'-As were about 7 times less toxic than ricin. Scatchard analyses of the binding of the radio-iodinated antibodies to Daudi cells showed that the intact RFB4 antibody bound 3-10 times more strongly than the other antibodies, whereas the Fab'-RFB4 bound 1.2 to 3.5 times more strongly than the Fab' fragments prepared from the other antibodies. Thus, the potent cytotoxic activity of the RFB4-As appears to derive, in part, from their superior binding affinity. Prior studies have shown that UV22-I and HD6 cross-react with certain normal human tissues lacking cells of B-cell lineage, whereas UV22-2 and RFB4 are B-cell-specific. This fact, together with its superior potency as an IT-A, suggests that RFB4 is the antibody of choice for preparing Fab'-As or IgG-As for in vivo therapy of human B-cell leukemias and lymphomas.

Animals↗
PubMed1988

Evaluation of ricin A chain-containing immunotoxins directed against CD19 and CD22 antigens on normal and malignant human B-cells as potential reagents for in vivo therapy.

Ricin A chain-containing immunotoxins (IT-As) specific for the human B-cell antigens, CD22 and CD19, were constructed using the monoclonal antibodies, HD6 and HD37, respectively. IT-As were prepared by coupling intact antibodies, F(ab')2, or Fab' fragments to native or chemically deglycosylated ricin A chain. The IT-As were then evaluated for cytotoxicity to normal and neoplastic human B-cells in vitro with the major objective of appraising their suitability for in vivo therapy of human B-cell tumors. The IT-As prepared with both the HD6 and HD37 antibodies were specifically toxic to normal B-cells and to most of the neoplastic B-cell lines tested. However, the IT-As prepared from HD6 were generally more potent than those prepared from HD37. On Daudi cells, to which the two antibodies bound in similar numbers and with similar affinities, IT-As prepared with intact HD6 antibody or its Fab' fragment were 10-fold and 1.5- to 4-fold more potent, respectively, than the corresponding HD37 IT-As. The IT-As constructed from intact HD6 antibody and native or deglycosylated A chain reduced protein synthesis in Daudi cells by 50% at a concentration of 1.2 X 10(-11) M indicating that they were only 5-fold less toxic to the cells than ricin itself. Intact HD37 IT-As produced equivalent inhibition of protein synthesis at 1.5 X 10(-10) M. With both antibodies, IT-As constructed from the Fab' fragments were 10- to 20-fold less potent than their intact antibody counterparts. Different neoplastic B-cell lines varied in sensitivity to the IT-As. In most cases, their sensitivity correlated with the levels of CD19 and CD22 antigens expressed. Neither HD6 nor HD37 IT-As affected the ability of normal human bone marrow cells to form granulocyte-macrophage colony-forming units in soft agar, suggesting that both antigens are absent from these progenitor cells. Examination of sections of frozen human tissues using immunoperoxidase staining procedures indicated that the antibodies did not bind to a panel of normal tissues lacking B-lymphocytes. These results suggest that HD6 and HD37 IT-As are candidates for in vivo therapy in humans with certain B-cell tumors. However, HD6 IT-As are more potent, reduce protein synthesis more completely, and hence appear to be the ITs of choice for treating tumors expressing the CD22 antigen.

Antigens, CD↗