We investigate the difference between surface matching and target matching for pelvic radiation image guidance. The uniqueness of our study is that all patients have multiple CT-on-rails (CTOR) scans to compare to corresponding AlignRT images. Ten patients receiving pelvic radiation were enrolled in this study. Two simulation CT scans were performed in supine and prone positions for each patient. Body surface contours were generated in treatment planning system and exported to AlignRT to serve as reference images. During treatment day, the patient was aligned to treatment isocenter with room lasers, and then scanned with both CTOR and AlignRT. Image-guidance shifts were calculated for both modalities by comparison to the simulation CT and the differences between them were analyzed for both supine and prone positions, respectively. These procedures were performed for each patient once per week for five weeks. The difference of patient displacement between AlignRT and CTOR was analyzed. For supine position, five patients had an average difference of displacement between AlignRT and CTOR along any direction (vertical, longitudinal, and lateral) greater than 0.5 cm, and one patient greater than 1 cm. Four patients had a maximum difference greater than 1 cm. For prone position, seven patients had an average difference greater than 0.5 cm, and three patients greater than 1 cm. Nine patients had a maximum difference greater than 1 cm. The difference of displacement between AlignRT and CTOR was greater for the prone position than for the supine position. For the patients studied here, surface matching does not appear to be an advisable image-guidance approach for pelvic radiation therapy for patients with either supine or prone position. There appears to be a potential for large alignment discrepancies (up to 2.25 cm) between surface matching and target matching.

No description available.

<p>There are many types of membrane lipids throughout Nature. Still little is known about synthesizing pathways and how different lipids affect the embedded membrane proteins. The most common lipids are glycolipids since they dominate plant green tissue. Glycolipids also exist in mammal cells as well as in most Gram-positive bacteria. Glycosyltransferases (GTs) catalyze the final enzymatic steps for these glycolipids. In the bacteria <i>Acholeplasma laidlawii</i> and <i>Streptococcus pneumonie</i> and in the plant <i>Arabidopsis thaliana</i>, GTs for mono-/di-glycosyl-diacylglycerol (-DAG) are suggested to be regulated to keep a certain membrane curvature close to a bilayer/nonbilayer phase transition. The monoglycosylDAGs are nonbilayer-prone with small headgroups, hence by themselves they will not form bilayer structures.</p><p>Here we have determined the genes encoding the main glycolipids of <i>A. laidlawii</i> and <i>S. pneumonie</i>. We have also shown that these GTs belong to a large enzyme group widely spread in Nature, and that all four enzymes are differently regulated by membrane lipids. The importance of different lipid properties were traced in a lipid mutant of <i>Escherichia coli</i> lacking the major (75 %), nonbilayer-prone/zwitterionic, lipid phosphatidylethanolamine. Introducing the genes for the GTs of <i>A. laidlawii</i> and two analogous genes from <i>A. thaliana</i> yielded new strains containing 50 percent of glyco-DAG lipids. The monoglyco-DAG strains contain significant amounts of nonbilayer-prone lipids while the diglyco-DAG strains contain no such lipids. Comparing these new strains for viability and the state of membrane-associated functions made it possible to connect different functions to certain lipid properties. In summary, a low surface charge density of anionic lipids is important in <i>E.coli</i> membranes, but this fails to be supportive if the diluting species have a too large headgroup. This indicates that a certain magnitude of the curvature stress is crucial for the membrane bilayer <i>in vivo</i>.</p>

No description available.

There are many types of membrane lipids throughout Nature. Still little is known about synthesizing pathways and how different lipids affect the embedded membrane proteins. The most common lipids are glycolipids since they dominate plant green tissue. Glycolipids also exist in mammal cells as well as in most Gram-positive bacteria. Glycosyltransferases (GTs) catalyze the final enzymatic steps for these glycolipids. In the bacteria Acholeplasma laidlawii and Streptococcus pneumonie and in the plant Arabidopsis thaliana, GTs for mono-/di-glycosyl-diacylglycerol (-DAG) are suggested to be regulated to keep a certain membrane curvature close to a bilayer/nonbilayer phase transition. The monoglycosylDAGs are nonbilayer-prone with small headgroups, hence by themselves they will not form bilayer structures. Here we have determined the genes encoding the main glycolipids of A. laidlawii and S. pneumonie. We have also shown that these GTs belong to a large enzyme group widely spread in Nature, and that all four enzymes are differently regulated by membrane lipids. The importance of different lipid properties were traced in a lipid mutant of Escherichia coli lacking the major (75 %), nonbilayer-prone/zwitterionic, lipid phosphatidylethanolamine. Introducing the genes for the GTs of A. laidlawii and two analogous genes from A. thaliana yielded new strains containing 50 percent of glyco-DAG lipids. The monoglyco-DAG strains contain significant amounts of nonbilayer-prone lipids while the diglyco-DAG strains contain no such lipids. Comparing these new strains for viability and the state of membrane-associated functions made it possible to connect different functions to certain lipid properties. In summary, a low surface charge density of anionic lipids is important in E.coli membranes, but this fails to be supportive if the diluting species have a too large headgroup. This indicates that a certain magnitude of the curvature stress is crucial for the membrane bilayer in vivo.

Since the introduction of the American Academy of Pediatrics Back to Sleep Campaign infants have not met the recommendation to “incorporate supervised, awake “prone play” in their infant’s daily routine to support motor development and minimize the risk of plagiocephaly”. Interventions are needed to increase infants’ tolerance for prone position and prone playtime to reduce the risk of plagiocephaly and motor delays. Associative learning is the ability to understand causal relationship between events. Operant conditioning is a form of associative learning that occurs by associating a behavior with positive or negative consequences. Operant conditions has been utilized to encourage behaviors such as kicking, reaching and sucking in infants by associating these behaviors with positive reinforcement. This dissertation is a compilation of three papers that each represent a study used to investigate a potential play based interventions to encourage prone motor skills in infants. The first paper describes a series of experiment used to develop the Prone Play Activity Center (PPAC) and experimental protocols used in the other studies. The purpose of the second study was to determine the feasibility of a clinical trial comparing usual care (low tech) to a high-tech intervention based on the principles of operant conditioning to increase tolerance for prone and improve prone motor skills. Ten infants participated in the study where parents of infants in the high tech intervention group (n=5) used the PPAC for 3 weeks to practice prone play. Findings from this study suggested the proposed intervention is feasible with some modifications for a future large-scale clinical trial. The purpose of the third study evaluated the ability of 3-6 months old infants to demonstrate AL in prone and remember the association learned a day later. Findings from this study suggested that a majority of infants demonstrated AL in prone with poor retention of the association, 24 hours later. Taken together these 3 papers provide preliminary evidence that a clinical trial of an intervention is feasible and that associative learning could be used to reinforce specific prone motor behaviors in the majority of infants.

Substance use behaviours have been viewed as the end products of a combination of influences. Numerous theories for working with substance use behaviour utilizing a multi-systemic approach have been proposed. In this project, an effort was made to control for limitations and problems that have often beset previous studies utilizing such an approach. The overall objective of the current project was to test, using a multi-systemic approach, the ability of the family socialization framework to explain the development of substance use patterns in youth and young adults. The central hypothesis of this project was that family socialization factors (contextual factors) affect and predict the development of an offspring’s personality (individual factors) and substance use behaviour. The behavioural genetic approach (i.e., the adoption design) was utilized to examine the genetic and environmental impacts on associations between factors. This project used secondary data analyses of general population data to examine the links between aspects of the family environment, personality, and substance use patterns. The Vancouver Family Survey data set used here contained information on fathers, mothers, and offspring from 405 families (328 biological and 77 adoptive) at two points in time. The development of personality and substance use behaviours over time, and associations with family socialization factors, were examined through three studies. Study 1 focused on the associations between offspring’s perspectives of fathers’ and mothers’ parental socialization and offspring’s polysubstance use. Study 2 investigated the development of addiction-prone personality characteristics and the predictive effects of family socialization and demographic variables on these characteristics. Study 3 explored the subscales of the Addiction-Prone Personality scale: impulsivity/recklessness, sensation seeking, negative view of self, and social deviance proneness. The descriptive characteristics of each subscale and changes in subscale scores over time were investigated. Also examined were transgenerational associations on these subscales, and potential relationships between personality subscales and choice of substance. The results of this project suggest that family socialization may be linked with both substance use behaviour and personality development over time. Nurturing family socialization is negatively associated with the development of addiction-prone personality characteristics. It is also negatively associated with the development of substance use behaviours. These results are consistent with previous studies utilizing a family socialization framework. The findings supporting the family socialization framework are very encouraging for the field of child, youth, and family-related practice. Some of the limitations of the current project, implications of the findings, and future research directions are discussed. / Graduate

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.

Introduction: Acute respiratory distress syndrome (ARDS), seen in critically ill patients, is a disease process that affects the lungs and directly impacts a patient’s oxygenation. Despite treatment, patients often die of ARDS secondary to systemic complications. Prone positioning has been introduced as a treatment to improve the outcomes of ARDS patients. This thesis summarized and critiqued recent literature on the outcomes of prone positioning in ARDS patients. Methodology: An initial literature search was conducted using CINAHL Plus with Text, Medline, Cochrane Database of Systematic Reviews, and US National Library of Medicine National Institutes of Health. Multiple search terms were used. Inclusion criteria consisted of peer reviewed research articles, academic journal articles, and evidence-based research or practices published within the last ten years. All studies included adult subjects and were published in the English language. Studies that did not address patient outcomes such as mortality, length of stay, or hemodynamic oxygenation were excluded from the review. Results: The review of literature contains one meta-analysis and two studies. Data indicated that prone positioning was statistically significant in reducing mortality when performed in sessions of 12 hours or longer (p=0.05). Hemodynamic oxygenation improved significantly after at least 48 hours of implementing prone positioning. There was no trend in the length of stay or duration in mechanical ventilation whether supine or prone positioning was used. Complications such as endotracheal tube dislodgement, incidence of ventilator-associated pneumonia, and pressure ulcers were reported in both supine and prone position with an increased risk of pressure ulcers and endotracheal tube obstruction in the prone position groups. Conclusions: Findings support a benefit in patient outcomes in patients placed in prone position with ARDS. Mortality was reduced when prone sessions lasted longer than 12 hours possibly due to the improvement in patient oxygenation 48 hours after initiation of prone positioning intervention. Further research is needed to solidify these findings and establish guidelines and optimal procedural methods to maximize patient outcomes and lower the incidence of patient complications.

Le Ketosis-Prone Diabetes (KPD) est un phénotype de diabète intermédiaire entre le diabète de type 1 et le diabète de type 2, fréquemment rencontré chez le sujet d’origine noire africaine. Cette forme de diabète suscite un intérêt certain de par son évolution clinique marquée notamment par la restauration de l’insulinosécrétion initialement altérée. Sobngwi et coll. en 2008 ont établi une association entre le virus HHV8 et le KPD chez des sujets Africains vivant en France. Nulle part ailleurs l’étude n’a été reproduite. L’objectif de cette thèse était de rechercher la potentielle association entre l’infection à HHV8 et le KPD ; puis d’évaluer l’impact de l’infection à HHV8 sur le profil inflammatoire des phénotypes du diabète de type 2. L’étude s’appuie sur une population de patients Africains vivant en Afrique admis consécutivement pour une décompensation hyperglycémique (glycémie à jeun≥2,5g/l) au Centre National d’Obésité de l’Hôpital Central de Yaoundé. Plus spécifiquement, il était question de :• étudier la fréquence du diabète non auto-immun à tendance cétosique (KPD); • étudier l’association entre le virus HHV8 et le KPD;• rechercher si l’infection à HHV8 est associée à un profil inflammatoire pouvant participer aux phénotypes de diabète. Etait inclus dans l’étude tout patient diabétique âgé de plus de 18 ans présentant un diabète aigu avec syndrome cardinal et cétonurie (KPD1), ceux ayant présenté un diabète inaugural aigu avec syndrome cardinal et cétonurie et en rémission depuis plus de trois mois et sans cétonurie à l’inclusion (KPD2), et ceux présentant un diabète de type 2 connu sans cétonurie (DT2). Etait exclu de l’étude tout patient présentant des stigmates d’auto-immunité du diabète de type 1 A, un diabète « MODY », une endocrinopathie, une maladie du pancréas, ou un diabète de type auto-immun. Chez l’ensemble des participants admis, nous avons collecté les données cliniques (le poids, la taille, l’IMC, le rapport tour de taille sur tour de hanche, la pression artérielle, et le pourcentage de graisse) et des prélèvements à jeun ont été effectués (sérum et cellules mononuclées du sang périphérique) pour les analyses biologiques : la glycémie par glucose oxydase, l’HbA1c par HPLC, les paramètres du profil lipidique par des methodes enzymatiques, les concentrations d’insuline et de peptide-C par électrochimiluminescence, les anticorps anti-HHV8 par immunofluorescence, l’ADN viral HHV8 par PCR en temps réel, et les marqueurs de l’inflammation par le Luminex. Les indices HOMA-β et HOMA-IR ont été utilisés pour évaluer l’insulinosécrétion et la sensibilité à l’insuline respectivement. Les marqueurs sérologiques de l’inflammation recherchés étaient : TNF-α, MCP-1, IL-8, MIP-1β, VEGF et MIP-1α... / Ketosis-Prone Diabetes (KPD) is a diabetes phenotype intermediate between type 1 and type 2 diabetes, frequently encountered in populations of African origin. This form of diabetes arouses some interest because of its clinical course marked in particular by restoring the initial impaired insulin secretion. Sobngwi et al. in 2008 established an association between HHV-8 virus and KPD in African population living in France. Nowhere else has the study been replicated. The objective of this thesis was to investigate the potential association between HHV-8 infection and KPD; then evaluate the impact of HHV-8 infection on the inflammatory profile of type 2 diabetes phenotypes. The study is based on African patients living in Africa consecutively admitted for hyperglycemic decompensation (Fasting blood glucose≥2,5g/l) at the National Obesity Centre of the Yaounde Central Hospital. More specifically, the issue was:• study the frequency of non-immune ketosis-prone diabetes (KPD);• investigate the association between HHV8 and KPD;• investigate whether HHV-8 infection is associated with an inflammatory profile that may participate in diabetes phenotypes.Was included in this study all diabetic patients old more than 18 years with acute diabetes with syndrome cardinal and ketonuria (KPD1), those who presented with an acute inaugural cardinal syndrome and diabetes ketonuria and in remission for more than three months and without ketonuria at baseline (KPD2), and those with type 2 diabetes experienced without ketonuria (T2D). Was excluded from the study all patient with stigmata of autoimmunity of type 1 A diabetes, diabetes "MODY", endocrinopathy, pancreatic disease or an autoimmune diabetes.Among all participants admitted, we collected clinical data (weight, height, BMI, waist to hip ratio, blood pressure, and the percentage of fat) and levies fasting were made (serum and peripheral blood mononuclear cells) for biological testing: glyceamia by glucose oxidase, HbA1c by HPLC, lipid profile by enzymatic methods, the insulin and C-peptide concentrations by electrochemiluminescence, anti-HHV8 antibodies by immunofluorescence, HHV8 viral DNA by real-time PCR, and markers of inflammation by Luminex. HOMA-β and HOMA-IR indices were used to assess insulinsecretion and insulinsensitivity respectively. Serological markers of inflammation investigated were : TNF-α, MCP-1, IL-8, MIP-1β, MIP-1α and VEGF...