Biomedical subjects
M M Gottesman
Publications and source records attributed to M M Gottesman.
Children in foster care: a nursing perspective on research, policy, and child health issues.
ISSUES AND PURPOSE: To examine the roles of public policy and poverty on the rising number of children in family foster care, and to examine the impact of different types of family foster care on children's well-being. CONCLUSIONS: Recent changes in welfare legislation increase the likelihood of family poverty, with a subsequent increase in the number of children in out-of-home care. Greater emphasis needs to be placed on preventing entry into out-of-home care, improving the quality of foster care, and giving children a voice in care decisions. PRACTICE IMPLICATIONS: Nurses have important roles to play in the prevention of family dissolution, the design of healthcare delivery systems for children in foster care, in evaluating and educating all types of foster families, and as advocates in legal and legislative proceedings.
Overview: homelessness in America.
Explore the source record for details and available documents.
Coexpression of a multidrug resistance gene (MDR1) and herpes simplex virus thymidine kinase gene in a bicistronic retroviral vector Ha-MDR-IRES-TK allows selective killing of MDR1-transduced human tumors transplanted in nude mice.
Ha-MDR-IRES-TK is a bicistronic vector that coexpresses the MDR1 gene and the herpes simplex virus thymidine kinase (HSV-TK) gene. In the present study we examined the effect of ganciclovir on MDR1-positive tumors that have been transduced with Ha-MDR-IRES-TK. To establish a human tumor xenograft model of MDR1-transduced recurrent tumors, human KB-3-1 carcinoma cells were transduced with HaMDR or Ha-MDR-IRES-TK, and one each of representative clones, termed KB/MDR and KB/MDR-TK, respectively, were isolated. KB/MDR and KB/MDR-TK showed similar levels of multidrug resistance in vitro. Vinblastine strongly inhibited the growth of the parental KB-3-1 tumors in nude mice but showed little or no effect against KB/MDR-TK tumors. Ganciclovir inhibited the in vivo growth of KB/MDR-TK tumors almost completely under conditions that did not affect the growth of KB-3-1 tumors. Coadministration of vinblastine and ganciclovir inhibited the in vivo growth of KB/MDR-TK premixed with KB-3-1 at any ratio. Long-term, high-level expression of human P-glycoprotein was observed in peripheral blood cells of mice transplanted with Ha-MDR-IRES-TK-transduced bone marrow cells. Ganciclovir eliminated the P-glycoprotein-positive normal blood cells. However, no systemic toxicity was observed. These results clearly demonstrate that it is possible to use ganciclovir to treat MDR1-positive tumors that have been unintentionally transduced with Ha-MDR-IRES-TK. This safety-modified vector should be useful for introducing the MDR1 gene into bone marrow cells to protect normal cells from the toxic effects of cancer chemotherapy.
Construction and characterization of bicistronic retroviral vectors encoding the multidrug transporter and beta-galactosidase or green fluorescent protein.
Multidrug resistance (MDR) can be conferred by overexpression of the adenosine triphosphate-driven multidrug transporter P-glycoprotein (Pgp) known as MDR1. Thus, two potential applications of the MDR1 gene that may be useful in gene therapy are the protection of bone marrow cells from the cytotoxic effects of chemotherapy regimens in cancer patients and its possible use as an in vivo selectable gene when linked to a therapeutic gene. In this study, we have designed two retroviral bicistronic expression vectors by linking the MDR1 gene to the reporters known as beta-galactosidase and the red-shifted green fluorescent protein (GFP). We report the creation of stable producer cell lines that synthesize virus particles carrying the MDR-internal ribosomal entry site (IRES)-lacZ and the MDR-IRES-GFP transgenes. These transcriptional fusions allow coordinate expression of Pgp and the reporter gene product to easily mark the MDR phenotype. Using the MDR-IRES-lacZ retrovirus, we demonstrate that periodic pulses of cytotoxic drug selection with a Pgp substrate enable sustained, long-term expression of the reporter beta-galactosidase in otherwise unstable transductants. We have also incorporated the improved features of GFP as a reporter gene into our MDR-IRES-GFP retrovirus. This vector allows rapid and specific identification of MDR1 gene transfer and expression in living cells either by fluorescence microscopy or by fluorescence-activated cell sorter analysis. These two MDR/reporter gene systems should be useful for in vivo studies, the evaluation of the potential of the MDR1 gene in gene therapy applications, and as a monitor of the selective efficacy of its MDR phenotype.