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Biomedical subjects

B C Murphy

Publications and source records attributed to B C Murphy.

9 recordsLinked to original sources
PubMed1992

Effects of extracellular matrix components and dihydrotestosterone on the structure and function of human prostate cancer cells.

The extracellular matrix (ECM) has been shown to play a major role in cell structure and function. Several studies have demonstrated that the ECM can alter cell morphology and effect DNA synthesis and gene expression. The ECM also interacts with growth hormones which have been shown to be located in or near the ECM where they are believed to effect cell structure and function. In the nontransformed cell, these ECM and hormone-mediated effects appear to be tightly regulated and this is believed to be accomplished through cell receptor-tissue matrix interactions. We, therefore, undertook a study to determine the effects of a variety of ECM components and the adrogenic hormone dihydrotestosterone (DHT) on the structure and function of the human prostate cancer cell line, LNCaP. The effects of individual matrix components in the presence and absence of 1 nM DHT on the static and dynamic morphology, growth rate, and PSA production of the LNCaP cell line were studied. We determine that the ECM and DHT interact in complex ways to effect cell structure and function. DHT produced alterations in cytoplasmic structure that increased cell size and decreased the nuclear area/cytoplasmic area ratio. Dynamic cell structure as measured by cell motility was very sensitive to the ECM components and the presence of DHT. PSA and growth could be regulated by substratum and DHT and there was an inverse relationship between PSA production and growth rate. These data exemplify the complex interactions which occur between prostate cancer cells, ECM components, and exogenous DHT that are reflected in cell structure and function.

Antigens, Neoplasm↗
PubMed1992

Effect of pentosan, a novel cancer chemotherapeutic agent, on prostate cancer cell growth and motility.

Pentosan is a new chemotherapeutic drug which is currently in Phase I clinical trials. In our experimental systems, in vivo, pentosan inhibits the growth of the highly metastatic MAT-LyLu (MLL) Dunning R3327 prostate cancer cell line only at toxic doses and has no apparent effect on growth in vitro. The mechanism of tumor inhibition of this drug is unknown; however, in vitro, pentosan exhibits a potent inhibition of cell motility. Cell motility is essential for tumor cell metastasis and angiogenesis. By blocking cell motility, pentosan has the potential to inhibit both tumor growth and metastasis. We have characterized the mechanism of motility inhibition by pentosan and believe it alters cell-extracellular matrix interactions. The mechanism of motility inhibition by pentosan appears to be independent of cytoskeletal structural alterations, including changes in microfilament and microtubule networks. Pentosan acts through a different mechanism than suramin, a drug which inhibits motility through inhibition of growth factor effects. In vitro, pentosan alters cellular contacts with the extravascular matrix and inhibits cell motility. In vivo, pentosan prolongs survival of rats injected with MLL cells by 25%, but did not appear to decrease the rate of primary tumor growth or the number of metastatic lesions in the treated animals. These data suggest that, in vivo, pentosan acts through an as yet undefined mechanism.

Animals↗
PubMed1992

Environmentally contaminated families: therapeutic considerations.

The unique stress for families of exposure to environmental toxins is discussed in terms of the physical characteristics of such contaminants and resultant adaptational dilemmas, the agent or cause of the injury, and institutional responses to the contamination. Recommendations for mental health professionals working with contaminated families are presented.

Adaptation, Psychological↗
PubMed1992

Educating mental health professionals about gay and lesbian issues.

Despite the large number of clients with gay and lesbian concerns, many mental health professionals remain biased and unqualified to serve them. Mental health professionals are poorly prepared to deal with sexuality in general and with gay and lesbian issues specifically. Education and training about gay and lesbian topics is needed both in graduate schools and in the field. This training should focus on three components: (1) information about sexual orientation, gay and lesbian lifestyles, and community resources; (2) the interface between the gay or lesbian client, his or her sexuality, and the effects of living in a heterosexist and homophobic society; and (3) the interaction between the attitudes, feelings, and sexual orientation of the clinician and of the client.

Adult↗
PubMed1991

The effect of extracellular matrix interactions on morphologic transformation in vitro.

There is emerging evidence that the structure and function of a cell is dependent in part on the contacts that cells make with the extracellular matrix. We report here the effect of extracellular matrices secreted from both normal and tumor cells have on the structure of normal rat kidney epithelial cells. Normal rat kidney cells plated on the basement membrane secreted by tumor cells adopt a morphology and phenotype which closely resembles a Kirsten-ras transformed normal rat kidney cell. This morphologic transformation was not observed for cells plated on individual extracellular matrix components or on basement membrane secreted by normal placenta cells. This suggests that tumor derived basement membrane has unique characteristics which may cause morphologic transformation of normal rat kidney cells.

Animals↗
PubMed1991

Modifications of the intermediate filament and nuclear matrix networks by the extracellular matrix.

The tissue matrix system is a dynamic, interacting structural network directly linking the nuclear matrix, cytoskeleton and the extracellular matrix. We report here that interaction of normal rat kidney epithelial cells (NRK) and Kirsten-ras transformed rat kidney cells, with an extracellular matrix secreted by tumor cells, causes modifications to the protein composition of the intermediate filament and nuclear matrix networks. The matrix networks are different between normal and transformed cells; however, these alterations by the tumor extracellular matrix are similar in both cell types. These data represent the first report that modification of the extracellular matrix environment can have an effect on the protein composition of the nuclear matrix.

Animals↗
PubMed1990

Atomic veterans and their families: responses to radiation exposure.

In-depth interviews with seven atomic veterans and their families indicated powerful psychological effects on all family members from exposure to low-level ionizing radiation. Four themes emerged: the invalidation of their experiences by government and other authority figures; family concerns about genetic effects on future generations; family members' desire to protect each other from fears of physical consequences; and desire to leave a record of their experiences to help prevent future suffering.

Abnormalities, Radiation-Induced↗
PubMed1975

Granulocyte transfusions in treatment of infections in patients with acute leukaemia and aplastic anaemia.

By use of the continuous-flow blood-cell separator 137 bags of granulocyte-rich plasma were obtained from normal donors (59 bags) and patients with chronic granulocytic leukaemia (C.G.L.) (78 bags). Eighty-nine courses of granulocyte transfusion therapy consisting of 1 or more such bags were administered to forty-one ABO-compatible patients with acute leukaemia or aplastic anaemia, who had definite or probable infections that had failed to respond to antibiotics. The fever resolved after 67% of courses of transfusions of two or more bags but after only 24% of transfusions of single bags of granulocytes (p less than 0-01), and this result suggests that this form of treatment is in general effective. Granulocytes from C.G.L. and normal donors were equally effective, although transfusion reactions were commoner after C.G.L. cells (33% versus 12%, respectively, p less than 0-05). C.G.L. grafts, and probable graft-versus-host disease, occurred in three recipients of unirradiated C.G.L. cells. Recipients of normal cells whose fevers resolved received on average four times as many granulocytes per sq.m. as those fevers did not respond. No such difference was found when C.G.L. cells were used. The fever was more likely to resolve in recipients with established or clinically probable bacterial or fungal infections than in those with fever of uncertain cause. Fever was less likely to resolve in recipients with peripheral blood granulocyte counts before transfusion of greater than 1000 per mul. It is concluded that granulocyte transfusion therapy is a valuable advance in the management of infections in neutropenic patients.

Adolescent↗