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L White

Publications and source records attributed to L White.

276 records · Page 16Linked to original sources
PubMedDate not supplied

Distribution of m-IBG in nude mice bearing LAN-5 neuroblastoma xenografts and in vitro cell culture.

BACKGROUND: Neuroblastoma is the commonest extra-cranial solid tumour of childhood and has a poor clinical outcome in patients with disseminated disease. Animal xenografts of this tumour offer a useful method of studying new diagnostic and therapeutic strategies for the tumour, prior to consideration of clinical trials. METHODS: 131I m-IBG was injected into nude mice bearing xenografts of the human neuroblastoma line LAN 5 in several sites. Animals were sacrificed at 24 (n = 6) and 48 hours (n = 5) and the biodistribution of the agent as well as uptake into the xenografted tumours was determined in a gamma well counter. In-vitro uptake of m-IBG into suspensions of LAN 5 cells was also determined in order to confirm the animal studies. RESULTS: There was no preferential accumulation of m-IBG in the xenografted tumours in any of the sites considered. Similarly, the in-vitro uptake of m-IBG showed the typical Michaelis-Menten kinetics of simple diffusion with no evidence of active uptake. CONCLUSIONS: The human neuroblastoma line LAN 5 failed to enrich m-IBG in either the xenograft or in-vitro situation. This may be related to the poor degree of differentiation of the tumour as evidenced by its unusual ease of growth in the sub-cutaneous site.

3-Iodobenzylguanidine↗
PubMedDate not supplied

Prospective study of pneumonia hospitalizations and mortality of U.S. older people: the role of chronic conditions, health behaviors, and nutritional status.

Mortality and hospitalization rates for pneumonia have increased among older Americans during recent years (1979-86), despite a national commitment to the reduction of premature deaths from pneumonia. A prospective study of deaths and hospitalizations attributable to pneumonia was conducted among 5,474 subjects ages 55 and older who participated in the NHANES I Epidemiologic Followup Study. Prevalent chronic conditions, health behaviors, and nutritional status indicators, measured at baseline, were examined in relation to pneumonia hospitalization and death during 12 years of followup. Mortality and hospitalization rates for pneumonia were higher among men than women, and higher among those ages 65 and older than among those 55-64 of both sexes. Risk of pneumonia death was higher among subjects with a history of congestive heart failure, stroke, cancer, or diabetes. Risk of pneumonia hospitalization was higher among subjects with a history of chronic obstructive pulmonary disease and among men who were current smokers. Daily alcohol consumption did not increase risk of pneumonia in this study population. Four measures of nutritional status were examined taking age, prevalent chronic conditions, and cigarette smoking into account: body mass index, arm muscle area, and serum albumin and hemoglobin levels. Risk of pneumonia death was 2.6 times higher in men in the lowest quartile, compared with men in the highest quartile, of body mass index. Similarly, the risk was 4.5 times higher among men in the lowest quartile of arm muscle area. Risk of death from pneumonia was 3.6 times higher among women in the lowest quartile of serum albumin levels compared with women in the highest quartile. Relative risks for these nutritional status indicators remained elevated after adjusting for age and the medical history risk factors. These risk factors should be taken into account when designing and evaluating pneumonia vaccination trials and community prevention programs.

Adult↗
PubMedDate not supplied

Tissue concentrations of doxorubicin in animal models with engrafted intraocular tumours.

The role of chemotherapy in the management of retinoblastoma remains unclear. In order to evaluate the responsiveness to conventional or experimental agents, a xenograft model had been developed, where human retinoblastoma is heterotransplanted to the anterior chambers of nude mouse eyes. Because doxorubicin had been found to be ineffective in therapeutic studies utilizing the model, experiments were conducted to evaluate the concentration of the drug in tissues, including intraocular engrafted tumour. The presence of doxorubicin was demonstrated in xenograft containing mouse eyes as well as in tumours of a comparable rabbit model. Distribution in extraocular tissues was consistent with previously published data. It is concluded that failure of response to doxorubicin in the xenograft model is not explained by lack of tumour penetration by the drug.

Animals↗
PubMedDate not supplied

Ferritin production and desferrioxamine cytotoxicity in human neuroblastoma cell lines.

In patients with neuroblastoma, elevated serum ferritin is correlated with adverse outcome. In this investigation, three human neuroblastoma cell lines have been characterised in terms of their levels of both intracellular and secreted ferritin and their response to the iron-chelating agent, desferrioxamine (deferoxamine). The cell lines differed markedly in respect of ferritin production as determined by radioimmunoassay. Intracellular and secreted ferritin concentrations for SH-SY5Y and BE(2)-C cells were several fold higher than that determined for IMR-32 cells. IMR-32 cells were most sensitive to desferrioxamine, BE(2)-C intermediate and SH-SY5Y the most resistant to the drug in terms of the respective ID50 values. Combining the differentiating agent retinoic acid with desferrioxamine did not enhance cytotoxicity in the neuroblastoma cells. The present data suggest that neuroblastoma cells secreting a relatively low levels of ferritin may be most responsive to iron chelating agents.

Deferoxamine↗
PubMedDate not supplied

Nurse manager selection process (Part 1). Survey of selection process (Part 2).

The Queen Elizabeth II Health Sciences Centre developed as a result of the merger of the five adult hospitals in Halifax, Nova Scotia. The merge involved 7000 staff members, 2700 of whom were nursing staff. Although mergers are becoming relatively common amongst health care organizations, there is a paucity of information in the literature to describe such an enormous human resource effort. This two-part article describes the hiring process for the selection and placement of 52 nurse managers over a concentrated time period of six weeks. Issues identified and resolved included: unionized and non unionized head nurses, the role of nurse managers, varying educational preparations, the time frame and organization of the process itself, options for unsuccessful incumbents, and multi unit and multi site management. The second part of the article reports on the results of a survey which was carried out to obtain feedback from the applicants and the interview panel members. The survey was conducted within eight weeks of the conclusion of the hiring process. Overall the process was deemed successful, albeit stressful. Some of the problems encountered are discussed.

Adult↗