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J Lark

Publications and source records attributed to J Lark.

6 recordsLinked to original sources
PubMed1999

Compliance with advance directives: nursing's view.

The purpose for this article is to define the terms of the Advance Directive within the legal and medical community and then to explore the bioethical implications of the Advance Directive for the nurse. Over the last decade, a legal document has entered the arena of the health care facility: the Advance Directive. Today, not only is the critical care nurse responsible for technical handling of the ever-changing medical equipment, advances in medicine and nursing, and new pharmaceuticals, but this nurse is also responsible for being ever cognizant of a very important legal document called the Advance Directive.

Advance Directives↗
PubMed1989

Effects of adriamycin and etoposide on the replication of adenovirus 5 in sensitive and resistant human tumour cells.

Adenovirus is a potential probe for identifying and understanding drug sensitivity in primary, nonproliferating cultures of human normal and tumour cells but the scope and limitations of such an approach first need to be evaluated in established cell lines. For this purpose we have identified an ovarian tumour cell line (CI-80-13S) with natural resistance to adriamycin, etoposide and crosslinking agents compared with other human tumour lines. Resistance to adriamycin correlated poorly with resistance to etoposide in these cell lines (r = 0.05). Adenovirus replication in drug-treated cells (viral capacity) was found to be differentially inhibited in sensitive cells when the drug was administered to cells simultaneously with infection (adriamycin) or 20 hr after infection (etoposide). Viral capacity could not be inhibited by more than 90% in sensitive cells. In contrast, no such plateau was exhibited in the dose-responses of cell survival or inhibition of cellular DNA synthesis, both of which distinguished sensitive from resistant cells. Adenovirus was not inactivated by preincubation with high doses of adriamycin or etoposide, thus confirming that no functionally-relevant damage is directly induced by these agents in DNA. Uptake of adriamycin and etoposide was similar in sensitive and resistant cells and both agents blocked cells in the G2 phase of the cell cycle. Protein-linked DNA was induced in sensitive cells. The results indicate that (a) these drugs have two dose-dependent effects in cells, one of which does not inhibit replication of adenovirus; and (b) inhibition of adenovirus replication could in principle be used to predict sensitivity to adriamycin and etoposide.

Adenoviridae↗
PubMed1989

In vitro sensitivity of ovarian cancer as determined by a short-term biochemical assay: comparison between primary and metastatic sites in the same patient.

Tumor sensitivity of ovarian cancer to cytotoxic drugs in vitro was examined between paired samples taken from the primary tumor and its metastases in the same patient. A 3-hour assay of primary cultures of the tumor was used to determine cellular response to the drugs by measurement of the incorporation of [3H]thymidine. Although there was variability, a reasonable correlation was found between the primary tumor and its different metastases, between the different metastases, and between the different tumor sites and cells from the peritoneal fluid. However, there was discordance between some of the pairings; the rate varied between 12 and 42% when the criterion was greater than 20% inhibition. Consistent drug sensitivity for all sites tested was present in only 8 of the 18 patients. Because of the discordance in some pairings, attempts should be made to sample all metastatic tumors, particularly those which cannot be removed completely by surgery. The discordant subgroup may be a source of false-negative and false-positive results of the assay.

Cisplatin↗
PubMed1986

The production of hydroxyl radical by human neutrophils stimulated by arachidonic acid--measurements by ESR spectroscopy.

Human neutrophils incubated with sodium arachidonate generated hydroxyl radicals. The radical formed an adduct with the spin trap 5', 5-dimethyl-l-pyrroline-N-oxide (DMPO) and was subsequently detected by electron spin resonance (ESR) spectroscopy. The ESR signal was inhibited by mannitol and superoxide dismutase but not by catalase. Removal of glucose from the reaction mixture or the presence of glucose metabolic inhibitors including 2-deoxy-D-glucose and 3-O-methyl-D-glucose did not affect the production of hydroxyl radical by the neutrophils. The ESR signal was, however, inhibited by the lipoxygenase inhibitors nordihydroguaiaretic acid and N-ethylmaleimide. The involvement of lipoxygenase in the production of hydroxyl radical was demonstrated by the trapping of the radical with DMPO in a reaction mixture of soybean lipoxygenase and arachidonic acid (AA). These findings support our previous postulation that the metabolism of AA via the lipoxygenase pathway is a source of hydroxyl radical in stimulated neutrophils.

3-O-Methylglucose↗