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S Knutsen

Publications and source records attributed to S Knutsen.

5 recordsLinked to original sources
PubMed2006

Mentoring Cambodian and Lao health professionals in tobacco control leadership and research skills.

DESIGN: The aim of the programme was to ultimately affect public health practice and policy in the Kingdom of Cambodia and Lao People's Democratic Republic (Lao PDR) by training key health professionals to conduct tobacco control research. SETTING: Encouraged by the World Health Organization's Framework Convention on Tobacco Control, a global partnership formed to build effective leadership to develop and guide national tobacco control agendas. The partners were the Ministries of Health (Cambodia and Lao PDR), non-government organisations (Adventist Development and Relief Agency in Cambodia and Laos) and an academic institution (Loma Linda University, Loma Linda, California, USA). SUBJECTS: 16 health professionals, 10 from Cambodia and 6 from Lao PDR, were selected by local advisory committees to enter a two-year, intensive tobacco research graduate certificate and research training programme. INTERVENTION: We developed a "Global Tobacco Control Methods" (GTCM) 28 unit certificate programme that was offered in five sessions from September 2003 to September 2005 at the National Institute of Public Health, Phnom Penh, Cambodia. As part of their coursework, the 16 trainees actively participated in the development and implementation of two research projects. In the first project, "Healthy Doc Healthy Patient" (HDHP), trainees adapted an existing, self-administered questionnaire designed to assess health practices and beliefs of medical students in Cambodia and Lao PDR. The second project involved the design of a national prevalence of tobacco use and health beliefs study in Cambodia using a multi-stage, cluster sample method. Trainees were sponsored to attend and present at international tobacco control conferences to enhance their awareness of the tobacco epidemic. RESULTS: As of September 2005, 14 trainees (8 from Cambodia and 6 from Lao PDR) completed the courses in the GTCM certificate programme. The HDHP study sampled four medical school classes (years 3, 4, 5 and 6) in both Cambodia (n = 330, 71.1% response rate) and Lao PDR (n = 386, 87.3% response rate). As part of the Cambodian adult tobacco prevalence study in Cambodia, 13,988 adults (ages > or = 18 years) were interviewed from all 22 provinces during the summer of 2005. Over the two years, more than half of the trainees participated substantially in local and regional tobacco control and research activities. Programme challenges included the trainees' limited English language and computer proficiency skills, both of which improved during the two years. CONCLUSIONS: With the successful completion of the certificate programme, the remaining two years of the grant will be used to prepare the trainees for positions of leadership within their Ministries of Health and other agencies to implement effective tobacco control policies based on locally-derived research findings.

Cambodia↗
PubMed2001

Dosimetric verification of a dedicated 3D treatment planning system for episcleral plaque therapy.

PURPOSE: Episcleral plaque therapy (EPT) is applied in the management of some malignant ocular tumors. A customized configuration of typically 4 to 20 radioactive seeds is fixed in a gold plaque, and the plaque is sutured to the scleral surface corresponding to the basis of the intraocular tumor, allowing for a localized radiation dose delivery to the tumor. Minimum target doses as high as 100 Gy are directed at malignant tumor sites close to critical normal tissues (e.g., optic disc and macula). Precise dosimetry is therefore fundamental for judging both the risk for normal tissue toxicity and tumor dose prescription. This paper describes the dosimetric verification of a commercially available dedicated treatment planning system (TPS) for EPT when realistic multiple-seed configurations are applied. MATERIALS AND METHODS: The TPS Bebig Plaque Simulator is used to plan EPT at our institution. Relative dose distributions in a water phantom, including central axis depth dose and off-axis dose profiles for three different plaques, the University of Southern California (USC) #9 and the Collaborative Ocular Melanoma Study (COMS) 12-mm and 20-mm plaques, were measured with a diode detector. Each plaque was arranged with realistic multiple 125I seed configurations. The measured dose distributions were compared to the corresponding dose profiles calculated with the TPS. All measurements were corrected for the angular sensitivity variation of the diode. RESULTS: Single-seed dose distributions measured with our dosimetry setup agreed with previously published data within 3%. For the three multiple-seed plaque configurations, the measured and calculated dose distributions were in good agreement. For the central axis depth doses, the agreement was within 4%, whereas deviations up to 11% were observed in single points far off-axis. CONCLUSIONS: The Bebig Plaque Simulator is a reliable TPS for calculating relative dose distributions around realistic multiple 125I seed configurations in EPT.

Brachytherapy↗
PubMed1993

Evidence for double helical kappa-carrageenan in aqueous LiI-solution and model for iodide binding.

NMR experiments with a 21412 Redfield observation pulse were carried out on a kappa-carrageenan aqueous solution containing 0.5M LiI. A detected hydrogen-bonded proton resonance at approximately 17.6 ppm, is in accordance with an ordered carrageenan structure in the solution similar to the double, parallel-stranded helix with interstrand hydrogen-bonds found in the condensed state by R.P. Millane, R. Chandrasekaran, S. Arnott, and I.C.M. Dea (Carbohydr. Res. 198, 1 1988). Starting with the published iota-carrageenan coordinates obtained from the Brookhaven Databank, we modelled this kappa-carrageenan structure by the molecular modelling software INSIGHTH-II. The kappa-carrageenan double-helix has a wide interior that can accommodate iodide. Conversely, the iota-carrageenan double-helix has a narrow interior not suited for a large ion like iodide. We propose that the detected selective iodide binding sites in the ordered kappa-carrageenan structure (H. Grasdalen, and O. Smidsrød, Macromolecules 14, 1842 1981) could very well be in the interior of the double-helix.

Binding Sites↗
PubMed1982

Chronopsies assess the within-day variability of blood pressure and pulse.

Blood pressure and pulse were monitored throughout 24 hours in 13 middle-aged men using a sphygmomanometer with an automatically inflatable cuff. These volunteers were in part mistakenly believed to have a "mildly elevated blood pressure" (in the light of a conventional non-chronobiologic approach, involving time-unspecified spot checks of blood pressure). Within about 24 hours, blood pressures and pulse varied remarkably: the coefficient of variation extended from 6.9 to 14.9% for systolic blood pressure (SBP), from 8.5 to 15.4% for diastolic blood pressure (DBP) and from 8.0 to 17.9% for pulse. By applying the single cosinor method (involving the least-squares fit of a 24-hour cosine curve), statistically significant circadian rhythms were observed in SBP, DBP, and pulse in all but 2 cases. In most cases, the timing of peak values was estimated to be in the evening for all 3 variables. Circadian rhythmicity accounted for up to 46, 30, and 42% of the total variability of SBP, DBP, and pulse, respectively. This marked circadian rhythmic variability is an important aspect of cardiovascular function.

Adult↗