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G Hill

Publications and source records attributed to G Hill.

173 records · Page 10Linked to original sources
PubMedDate not supplied

The epitheliome: agent-based modelling of the social behaviour of cells.

We have developed a new computational modelling paradigm for predicting the emergent behaviour resulting from the interaction of cells in epithelial tissue. As proof-of-concept, an agent-based model, in which there is a one-to-one correspondence between biological cells and software agents, has been coupled to a simple physical model. Behaviour of the computational model is compared with the growth characteristics of epithelial cells in monolayer culture, using growth media with low and physiological calcium concentrations. Results show a qualitative fit between the growth characteristics produced by the simulation and the in vitro cell models.

Algorithms↗
PubMedDate not supplied

A population-based study of the usefulness of screening for neuroblastoma.

BACKGROUND: Neuroblastoma has many characteristics which suggest that preclinical detection might improve outcome. The Quebec Neuroblastoma Screening Project was initiated to determine whether mass screening could reduce mortality in a large cohort of infants. As an early endpoint, we report whether screening could reduce the incidence of poor-prognosis neuroblastoma in children with advanced-stage disease over 1 year of age. METHODS: All 476,603 children born in the province of Quebec during the 5-year period of May 1, 1989, to April 30, 1994, were eligible for urinary assay of homovanillic acid and vanillylmandelic acid at 3 weeks and 6 months of age. Children with a positive screen were referred to one of four paediatric cancer centres in the province for uniform evaluation and treatment if necessary. Standardised incidence ratios (SIRs) were calculated for neuroblastoma in the province and two similar population-based controls, the state of Minnesota and the province of Ontario, during the same period of time and with similar ascertainment procedures. FINDINGS: Compliance with screening in Quebec province was 91% at 3 weeks (n = 425,816) and 74% at 6 months (n = 349,706). Through July 31, 1995, with a follow-up of the birth cohort of 15-75 months, 118 cases of neuroblastoma were diagnosed, 43 detected preclinically by screening, 20 detected clinically before screening at 3 weeks of age, and 55 detected clinically after 3 weeks of age having normal screens (52) or never screened (3). Retrospective analysis of stored samples confirmed that 49 of 52 patients missed by screening had levels of catecholamine metabolites that were too low to be detected at 6 months or earlier. Based on US Surveillance, Epidemiology and End Results data, 54.5 cases of neuroblastoma would have been expected in Quebec province during the study period, for an SIR of 2.17 (95% CI 1.79-2.57, p < 0.0001). For the two control groups, 43 and 80 cases of neuroblastoma were detected, respectively, compared with 37.9 and 85.4 expected, overall SIR 1.00 (not significant). SIRs for Quebec province by age at diagnosis in yearly intervals show a marked increased incidence under 1 year of age (SIR 2.85, 2.26-3.50), with no reduction in incidence in subsequent years. Limiting analysis to only patients diagnosed over 1 year of age with advanced-stage disease, 22 cases were detected in Quebec province versus 14.4 expected (SIR 1.52, 0.95-2.23). Data in the two control groups show no significant increase or decrease in any-stage disease in children under or over the age of 1 year, except for an increase in early-stage disease in Minnesota children over 1 year: 10 versus 3.8 expected (SIR 2.67, 1.27-4.58). INTERPRETATION: Screening for neuroblastoma increases the incidence in infants without decreasing the incidence of unfavourable advanced-stage disease in older children. It is unlikely that screening for neuroblastoma in infants will reduce mortality for this disease.

Chromatography, Thin Layer↗
PubMedDate not supplied

A scoring system for the quantitative evaluation of oral mucositis during bone marrow transplantation.

A system for assessing the severity of mucositis in patients undergoing bone marrow transplantation (BMT) is presented. Ten criteria were graded to give component scores together with a total score. The overall severity score ranged from 0 through 21. Scores were assigned three times daily by nursing staff members and verified daily by the attending dental and medical practitioners. Total scores were highly reproducible and were related to the severity of neutropenia. Variation between sequential total scores was not related to interexaminer variation but rather to changes in the severity of oral mucositis. Component scores provided a useful means for transmitting oral health information between health care personnel. Total scores were used to regulate the nature and frequency of oral hygiene procedures for patients undergoing BMT as well as other hematology/oncology patients. Application of this oral assessment system to other institutional settings may be beneficial.

Adolescent↗
PubMedDate not supplied

Professional issues associated with the role of the research nurse.

This article presents the findings of two studies undertaken during 2002 and 2003 that aimed to explore a range of professional issues facing research nurses. The results indicated that the position of research nurses is often complex because of a combination of contractual and accountability arrangements. This position can be intensified by feelings of isolation, a lack of professional support and limited specific educational opportunities. Experienced research nurses are often highly skilled in terms of their specialist clinical knowledge, and have a comprehensive understanding of all aspects of the research process, including methodological, ethical and practical issues.

Attitude of Health Personnel↗
PubMedDate not supplied

Recent trends in morbidity and mortality rates for abdominal aortic aneurysms.

OBJECTIVES: To examine recent trends in mortality and morbidity rates from aortic aneurysms among Canadian seniors. DESIGN: Retrospective study. PARTICIPANTS: Men and women age 65 years or older who were hospitalized in Canada with a primary diagnosis of aortic aneurysm or whose underlying cause of death was aortic aneurysm. MAIN RESULTS: Unlike other circulatory diseases which have shown marked declines, mortality and morbidity rates from aortic aneurysms have remained constant over the last 10 years. Risks for male seniors are 4-5 times greater than for females. CONCLUSIONS: Since mortality and morbidity from aortic aneurysms have not decreased and screening offers potential benefits, costs and benefits of screening need to be quantified.

Aged↗
PubMedDate not supplied

Use of laboratory reports to assess cervical cancer screening in a community.

Cancer of the uterine cervix, the sixth most common cancer among women, is still considered a significant health problem, despite declining mortality rates during recent decades. In Baltimore, the age-adjusted mortality rates for cervical cancer are significantly higher than the U.S. average, for both black and white women. Early detection of cervical cancer through screening with the Papanicolaou (Pap) test has shown to decrease mortality by preventing development of invasive disease, and intervention programs have been developed to increase use of Pap testing. However, the evaluation of those programs is difficult, as self-reports of Pap screening may be inaccurate, and repeated inquiries about Pap tests may influence the behavior being studied. We report in this article a method to use data from cytopathology laboratories to estimate the use of Pap screening by women in a defined population. This approach can be used to evaluate changes in receipt of Pap smears and to provide feedback to intervention programs.

Adult↗