Search PubMed⌕ Search

Biomedical subjects

L Moore

Publications and source records attributed to L Moore.

At least 253 records · Page 14Linked to original sources
PubMedDate not supplied

Separation of a breast cancer cell line from human blood using a quadrupole magnetic flow sorter.

We have developed a quadrupole magnetic flow sorter (QMS) to facilitate high-throughput binary cell separation. Optimized QMS operation requires the adjustment of three flow parameters based on the immunomagnetic characteristics of the target cell sample. To overcome the inefficiency of semiempirical operation/optimization of QMS flow parameters, a theoretical model of the QMS sorting process was developed. Application of this model requires measurement of the magnetophoretic mobility distribution of the cell sample by the cell tracking velocimetry (CTV) technique developed in our laboratory. In this work, the theoretical model was experimentally tested using breast carcinoma cells (HCC1954) overexpressing the HER-2/neu gene, and peripheral blood leukocytes (PBLs). The magnetophoretic mobility distribution of immunomagnetically labeled HCC1954 cells was measured using the CTV technique, and then theoretical predictions of sorting recoveries were calculated. Mean magnetophoretic mobilities of (1-3) x 10(-4) mm(3)/(T A s) were obtained depending on the labeling conditions. Labeled HCC1954 cells were mixed with unlabeled PBLs to form a "spiked" sample to be separated by the QMS. Fractional recoveries of cells for different flow parameters were examined and compared with theoretical predictions. Experimental results showed that the theoretical model accurately predicted fractional recoveries of HCC1954 cells. High-throughput (3.29 x 10(5) cells/s) separations with high recovery (0.89) of HCC1954 cells were achieved.

Algorithms↗
PubMedDate not supplied

Flow through, immunomagnetic cell separation.

A brief, process-oriented overview of immunologically based cell separation technology is presented. In addition, the design and preliminary experimental data of two unique flow-through immunomagnetic cell separation devices are presented. The first design is based on a dipole magnetic field, while the second design is basis on a quadrupole magnetic field. The dipole design can "fractionate" an inlet, magnetically labeled, cell stream into different outlet streams on the basis of the degree to which the cell is immunomagnetically labeled. The quadrupole separator splits an inlet, immunomagnetically labeled, cell stream into two outlet streams in which the purity, recovery, and potentially the degree to which the cells are immunomagnetically labeled is controlled by the flow rates in the inlet and outlet flows. A 99% purity and 86% recovery have been achieved with this system. Some distinct advantages of these two systems are the potential of high purity, recovery, and throughput at a cost which is potentially significantly lower than current, comparable technologies.

Electrochemistry↗
PubMedDate not supplied

Drug abuse treatment on demand in San Francisco: preliminary findings.

This article reports on a process and capacity evaluation of San Francisco's Treatment on Demand Initiative, which was launched in 1997 to increase availability of publicly-funded substance abuse treatment. For the process evaluation, data from public documents, interviews with community key informants, and newspaper articles were analyzed. For the capacity evaluation, budget documents and admissions data for publicly-funded substance abuse treatment in San Francisco for fiscal years 1995-1998 were analyzed. Results from the process evaluation document the development of the community-oriented Treatment on Demand Planning Council, and its efforts to not only expand treatment, but to create a continuum of services to address the needs of San Francisco's richly diverse communities, to provide service enhancements, and to prioritize service needs. Process evaluation results also highlight the complexities of implementing treatment on demand, including the difficulty of opening new programs. Results from the capacity evaluation indicate that the San Francisco budget supporting publicly-funded treatment increased from $32 million to $45.2 million over four years. During the same period, the number of persons entering the system in a single year increased by 18%, and the number of admissions in a single year increased by 15%. Implications of these findings are discussed.

Female↗
PubMedDate not supplied

Measuring quality and effectiveness of prehospital EMS.

INTRODUCTION: In today's health care environment, the demand for objective comparative information about the performance of health care organizations and providers has created a need for data-driven evaluation processes. In response, national organizations and federal agencies have established quality indicators, created tools to measure performance according to those indicators, and issued report cards for individual providers, as well as health care organizations. PURPOSE: Emergency medical services (EMS) systems are no different from other health care systems in the need for objective comparative system information to assist government officials at all levels in establishing relevant policy, selecting appropriate system design, and monitoring system quality and effectiveness. Governmental decision makers, payers, and consumers are demanding objective evidence that they are receiving value and quality for the cost of EMS. EMS systems administrators also require objective feedback about performance that can be used internally to support improvement efforts and externally to demonstrate accountability to the public and other stakeholders. To date, there are few validated indicators of effectiveness and quality in EMS systems. Moreover, most potential indicators have not been studied for use in systemwide evaluation. As a result, there are no universally accepted methods of measurement. The following paper examines traditional efforts to assure quality in EMS systems, while assessing the need to go beyond the traditional to establish measurable indicators of system quality. Valid and measurable indicators will provide a basis for establishing benchmarks of performance. In the future, these benchmarks will facilitate comparisons of a system with itself, as well as with other systems.

Decision Making↗
PubMedDate not supplied

Rationale for selecting exfoliated bladder cell micronuclei as potential biomarkers for arsenic genotoxicity.

Biomarkers of effect have important potential in epidemiology, since they may enable ascertainment of exposure-effect associations in relatively inexpensive cross-sectional studies, with confirmation by short follow-up after cessation of exposure. Arsenic is known to cause human skin and lung cancer, and may also cause various internal cancers including bladder, kidney, and liver cancer. The strongest epidemiological association between arsenic ingestion and an internal cancer is that with bladder cancer. Epidemiological studies of a Taiwanese population exposed to high levels of arsenic from drinking water reported relative risks for bladder cancer well above any other known environmental carcinogen. Populations at increased risk for bladder cancer from other exposures, such as smoking and schistosomiasis infection, have elevated frequencies of micronuclei in exfoliated bladder cells. We have therefore proposed that the bladder cell micronucleus assay could be an appropriate biological marker of genotoxic effect of arsenic exposure. In this paper, we present the rationale for choosing the bladder cell micronucleus assay as a potential biomarker of effect for arsenic. We also briefly describe the studies we are conducting using this biomarker in currently exposed populations.

Arsenic↗
PubMedDate not supplied

Self-assessment: a personalized approach to nursing during pregnancy.

A Prenatal Self-Assessment questionnaire was developed to aid in personalizing nursing care in a large medical center prenatal clinic. The questionnaire complements the standard prenatal record, which is intended primarily to document medical findings and treatment. The tool was used with more than 100 mothers who were receptive to this approach. The women's responses to questions about their feelings and thoughts concerning their pregnancies facilitated identification of potential problems and provided a basis for individualized and comprehensive care.

Consumer Behavior↗
PubMedDate not supplied

Mutational analysis of a DNA sequence involved in linking gene expression to the cell cycle.

Entry of budding yeast cells into the mitotic cell cycle requires the activity of a conserved regulatory kinase encoded by the CDC28 gene. The kinase is thought to trigger entry into the cell cycle or START, through association with a number of regulatory subunits known as G1 cyclins. A number of genes whose transcription is dependent on CDC28 and thus linked to START are controlled by two transcription factors, SWI4 and SWI6. The genes controlled by SWI4 and SWI6 include two known G1 cyclins (CLN1 and CLN2), a putative new G1 cyclin (HCS26), and the HO gene whose product initiates cell type switching. SWI4 and SWI6 act through a repeated sequence element, SCB (SWI4,6-dependent cell cycle box), found 2-10 times in the upstream regulatory sequences of target genes. We have constructed a library of mutants in the SCB using doped oligonucleotide mutagenesis. All single base pair changes examined compromised the ability of the SCB to activate transcription in vivo. Analysis of the behaviour of the mutant SCBs in an in vitro DNA binding assay shows that the inability to activate transcription can be explained by reduced binding of SWI4 and SWI6 to the mutant SCBs. This analysis, together with a consideration of the SCBs found upstream of known SWI4,6-dependent genes, leads to the proposal of a revised consensus sequence for this important regulatory element.

Base Sequence↗