Дисертації з теми "Biological dose"
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1
Fenwick, John David. "Biological modelling of pelvic radiotherapy : potential gains from conformal techniques." Thesis, Institute of Cancer Research (University Of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322314.
Повний текст джерела
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Verma, Malvika. "Gastric resident systems for large dose drug delivery." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/123066.
Повний текст джерелаАнотація:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biological Engineering, 2019Cataloged from PDF version of thesis.
Includes bibliographical references (pages 154-176).
Lack of medication adherence is a worldwide problem. As many as 50-70% of patients have trouble following treatment recommendations. Whereas adherence is driven by many factors including the socioeconomic status of a patient and the quality of the health care team, drug regimen complexity also affects treatment outcomes. For example, adherence decreases as the number of pills per dose and the number of doses per day increases. For diseases where potent medications are available, depot formulations provide sustained drug release to simplify dosing. For diseases lacking potent compounds for treatment, there remains an unmet need for depot systems that could transform medication adherence. Tuberculosis (TB) is one such disease with a high pill burden, where poor patient adherence to the treatment regimen is a major cause of treatment failure and contributes to the emergence of drug-resistant TB strains.
For example, an average 60-kg patient with TB needs to take 3.3 g of antibiotics per day, which is a dose that exceeds the largest swallowable capsule and current depot systems. According to the World Health Organization (WHO), 10 million people developed TB in 2017 with a global economic burden amounting to $12 billion annually. This thesis presents a solution to the challenge of prolonged dosing for regimens such as TB that require multigram drug dosing. First, a gastric resident system (GRS) compatible with transesophageal administration was designed using biocompatible materials. The GRS consists of a series of drug pills on a coiled superelastic nitinol wire; the ends are protected with a retainer and tubing. Safe administration, gastric retention for 1 month, and retrieval of the GRS were demonstrated in a swine model. Next, sustained release formulations for 6 TB antibiotics were formulated into drug-polymer pills, and first-order drug release kinetics were achieved in vitro.
Then, the GRS was demonstrated to be capable of safely encapsulating and releasing 10 grams of an antibiotic over the period of weeks in a swine model. Lastly, end-user assessment was evaluated with a field questionnaire in India and an economic model to estimate the impact of the GRS on the health care system. There are multiple applications of the GRS in the field of infectious diseases, as well as for other indications where multigram depots could impart meaningful benefits to patients, helping maximize adherence to their medication.
"Funding and Resources: -- Bill and Melinda Gates Foundation -- National Institutes of Health -- National Science Foundation Graduate Research Fellowship -- MIT Tata Center and leadership team for believing in and guiding our project"
by Malvika Verma.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Biological Engineering
3
Hollmark, Malin. "Absorbed dose and biological effect in light ion therapy." Doctoral thesis, Stockholm : Medical Radiation Physics, Stockholm university together with KI, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7756.
Повний текст джерела
4
Zackrisson, Björn. "Biological effects of high energy radiation and ultra high dose rates." Doctoral thesis, Umeå universitet, Onkologisk radiobiologi, 1991. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-96889.
Повний текст джерелаАнотація:
Recently a powerful electron accelerator, 50 MeV race-track microtron, has been taken into clinical use. This gives the opportunity to treat patients with higher x-ray and electron energies than before. Furthermore, treatments can be performed were the entire fractional dose can be delivered in parts of a second. The relative biological effectiveness (RBE) of high energy photons (up to 50 MV) was studied in vitro and in vivo. Oxygen enhancement ratio (OER) of 50 MV photons and RBE of 50 MeV electrons were investigated in vitro. Single-fraction experiments, in vitro, using V-79 Chinese hamster fibroblasts showed an RBE for 50 MV x-rays of approximately 1.1 at surviving fraction 0.01, with reference to the response to 4 MV x- rays. No significant difference in OER could be demonstrated. Fractionation experiments were carried out to establish the RBE at the clinically relevant dose level, 2 Gy. The RBE calculated for the 2 Gy/fraction experiments was 1.17. The RBEs for 20 MV x-rays and 50 MeV electrons were equal to one. In order to investigate the validity of these results, the jejunal crypt microcolony assay in mice was used to determine the RBE of 50 MV x-rays. The RBE for 50 MV x-rays in this case was estimated to be 1.06 at crypt surviving fraction 0.1. Photonuclear processes are proposed as one possible explanation to the higher RBE for 50 MV x-rays. Several studies of biological response to ionizing radiation of high absorbed dose rates have been performed, often with conflicting results. With the aim of investigating whether a difference in effect between irradiation at high dose rates and at conventional dose rates could be verified, pulsed 50 MeV electrons from a clinical accelerator were used for experiments with ultra high dose rates (mean dose rate: 3.8 x 10^ Gy/s) in comparison to conventional (mean dose rate: 9.6 x 10"^ Gy/s). V-79 cells were irradiated in vitro under both oxic and anoxic conditions. No significant difference in relative biological effectiveness (RBE) or oxygen enhancement ratio (OER) was observed for ultra high dose rates compared to conventional dose rates. A central issue in clinical radiobiological research is the prediction of responses to different radiation qualities. The choice of cell survival and dose response model greatly influences the results. In this context the relationship between theory and model is emphasized. Generally, the interpretations of experimental data are dependent on the model. Cell survival models are systematized with respect to their relations to radiobiological theories of cell kill. The growing knowledge of biological, physical, and chemical mechanisms is reflected in the formulation of new models. This study shows that recent modelling has been more oriented towards the stochastic fluctuations connected to radiation energy deposition. This implies that the traditional cell survival models ought to be complemented by models of stochastic energy deposition processes at the intracellular level.S. 1-44: sammanfattning, s. 47-130: 5 uppsatser
digitalisering@umu
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Hann, Robert Mark. "Estimation of the median effective dose in quantal response biological assay." Thesis, Liverpool John Moores University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299065.
Повний текст джерела
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Ali, Yasmine. "Biological dose estimation in hadrontherapy using the GATE Monte Carlo simulation platform." Thesis, Lyon, 2021. http://www.theses.fr/2021LYSE1329.
Повний текст джерелаАнотація:
Un des challenges en hadronthérapie est l'estimation de la dose biologique. Les systèmes de planification de traitement (TPS) doivent optimiser les faisceaux de traitement en prenant en compte la prédiction de la dose biologique en plus de la prédiction de la dose physique. Pour estimer la dose biologique, des modèles biophysiques ont été développés tels que les modèles mMKM et NanOx. Les paramètres d'entrée de ces modèles peuvent être estimés grâce à des codes de calculs Monte Carlo en structure de trace. Nous utilisons les codes Geant4-DNA et LPCHEM et les comparons pour évaluer leurs différences. Les deux codes peuvent simuler les radiations ionisantes jusqu'à l'eV ainsi que la production d'espèces radiolytiques suite à la radiolyse de l'eau entre la picoseconde et la microseconde. Les modèles biophysiques permettent des calculs de dose complexes à l'échelle du voxel en les couplant à des codes de calcul Monte Carlo. Nous avons développé un outil pour la plateforme de calcul Monte Carlo GATE, le "Biodose actor", dans le but d'estimer la dose biologique pour des pics de Bragg étalés issus de lignes cliniques et précliniques, irradiant avec des faisceaux de protons, d'ions hélium et d'ions carbone. Nous avons comparé les codes Geant4-DNA et LPCHEM pout la simulation de spectres nanodosimétriques dans le cœur de trace d’ion et la production d'espèce radiolytiques dans l’eau par des particules chargées (10 MeV protons). Les spectres totaux d’énergie spécifique dans des cibles nanométriques ainsi que les rendements d’espèces radiolytiques pour les deux codes sont en bon accord. En plus de l’implémentation du BioDose actor dans GATE, l’outil a été testé et validé avec des données expérimentales de survie cellulaire obtenues grâce à différents pics de Bragg étalés. Cet outil facilitera les comparaisons et évaluation des diffèrents modèles biophysiquesOne of the current challenges in hadrontherapy is the evaluation of the biological effects due to microscopic pattern of energy deposition of ions. Treatment Planning Systems (TPS) should optimize beam parameters taking into account their predictions through the calculation of the biological dose in addition to the physical dose. To estimate the biological dose, biophysics models have been developed such as the mMKM and NanOx models. Some input parameters of the models are generally estimated with Monte Carlo Track Structure Codes such as Geant4-DNA and LPCHEM codes. Both codes are able to perform the simulation of ion and electron transport in water down to some eV as well as the evaluation of the chemical species generated during water radiolysis between 10-12 and 10-6 s. In this work, we first compared the outcome of LPCHEM and Geant4-DNA in terms of specific energy in nano and micro targets as well as yields of chemical species (input of the biophysical models). Then, we enhanced the GATE Monte Carlo simulation platform by creating a “Biodose actor” in order to estimate the biological dose for different clinical Spread-out Bragg Peaks (SOBP) with hydrogen, helium and carbon ion beams. We performed the first comparison between the LPCHEM and Geant4-DNA codes for the simulation of nanodosimetry spectra in the track core and the production of chemical species yields for water irradiations with charged particles (10 MeV protons). The total specific energy spectra in nanometric targets and the chemical yields predicted by the two codes are in good agreement. Besides the implementation of the BioDose actor in GATE has been tested and validated with comparison against experimental cell survival obtained in several SOBP. This tool paves the way of facilitated benchmarking between different models and evaluation approaches
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Gayzik, Francis Scott. "Optimal Control of Thermal Damage to Biological Materials." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/35087.
Повний текст джерелаАнотація:
Hyperthermia is a cancer treatment modality that raises cancerous tissue to cytotoxic temperature levels for roughly 30 to 45 minutes. Hyperthermia treatment planning refers to the
use of computational models to optimize the heating protocol to be used in a hyperthermia
treatment. This thesis presents a method to optimize a hyperthermia treatment heating
protocol. An algorithm is developed which recovers a heating protocol that will cause a
desired amount of thermal damage within a region of tissue. The optimization algorithm is
validated experimentally on an albumen tissue phantom.The transient temperature distribution within the region is simulated using a two- dimensional, finite-difference model of the Pennes bioheat equation. The relationship between temperature and time is integrated to produce a damage field according to two different models; Henriques'' model and the thermal dose model (Moritz and Henriques (1947)), (Sapareto and Dewey (1984)). A minimization algorithm is developed which re duces the value of an objective function based on the squared difference between an optimal and calculated damage field. Either damage model can be used in the minimization algorithm. The adjoint problem in conjunction with the conjugate gradient method is used to minimize the objective function of the control problem.
The flexibility of the minimization algorithm is proven experimentally and through a variety of simulations. With regards to the validation experiment, the optimal and recovered regions of permanent thermal damage are in good agreement for each test performed. A sensitivity analysis of the finite difference and damage models shows that the experimentally-obtained extent of damage is consistently within a tolerable error range.
Excellent agreement between the optimal and recovered damage fields is also found in
simulations of hyperthermia treatments on perfused tissue. A simplified and complex model
of the human skin were created for use within the algorithm. Minimizations using both the
Henriques'' model and the thermal dose model in the objective function are performed.
The Henriques'' damage model was found to be more desirable for use in the minimization algorithm than the thermal dose model because it is less computationally intensive
and includes a mechanism to predict the threshold of permanent thermal damage. The
performance of the minimization algorithm was not hindered by adding complexity to the skin
model. The method presented here for optimizing hyperthermia treatments is shown to be
robust and merits further investigation using more complicated patient models.
Master of Science
8
Gayzik, F. Scott. "Optimal Control of Thermal Damage to Biological Materials." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/35087.
Повний текст джерелаАнотація:
Hyperthermia is a cancer treatment modality that raises cancerous tissue to cytotoxic temperature levels for roughly 30 to 45 minutes. Hyperthermia treatment planning refers to the use of computational models to optimize the heating protocol to be used in a hyperthermia treatment. This thesis presents a method to optimize a hyperthermia treatment heating protocol. An algorithm is developed which recovers a heating protocol that will cause a desired amount of thermal damage within a region of tissue. The optimization algorithm is validated experimentally on an albumen tissue phantom.
The transient temperature distribution within the region is simulated using a two-dimensional, finite-difference model of the Pennes bioheat equation. The relationship between temperature and time is integrated to produce a damage field according to two different models; Henriques'' model and the thermal dose model (Moritz and Henriques (1947)), (Sapareto and Dewey (1984)). A minimization algorithm is developed which re duces the value of an objective function based on the squared difference between an optimal and calculated damage field. Either damage model can be used in the minimization algorithm. The adjoint problem in conjunction with the conjugate gradient method is used to minimize the objective function of the control problem.
The flexibility of the minimization algorithm is proven experimentally and through a variety of simulations. With regards to the validation experiment, the optimal and recovered regions of permanent thermal damage are in good agreement for each test performed. A sensitivity analysis of the finite difference and damage models shows that the experimentally-obtained extent of damage is consistently within a tolerable error range.
Excellent agreement between the optimal and recovered damage fields is also found in simulations of hyperthermia treatments on perfused tissue. A simplified and complex model of the human skin were created for use within the algorithm. Minimizations using both the Henriques'' model and the thermal dose model in the objective function are performed. The Henriques'' damage model was found to be more desirable for use in the minimization algorithm than the thermal dose model because it is less computationally intensive and includes a mechanism to predict the threshold of permanent thermal damage. The performance of the minimization algorithm was not hindered by adding complexity to the skin model. The method presented here for optimizing hyperthermia treatments is shown to be robust and merits further investigation using more complicated patient models.Master of Science
9
Harvey, Jane Ellen. "Long-term and high dose opioid medicine use in the U.K." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/52175/.
Повний текст джерелаАнотація:
Introduction The number of prescriptions dispensed for opioid medicines has increased in the U.K. in the last two decades and studies have shown patients are receiving opioids for longer periods than in the past. There is a lack of evidence as to the effectiveness of these drugs when used long-term, as efficacy evidence is taken from short clinical trials in populations who do not have the comorbidities commonly seen in chronic pain patients. Large observational studies of patients prescribed opioid medicines outside of clinical trials, have identified that some patients taking long-term opioids are reporting they are still in high levels of pain. There is also a concern that patients are receiving high dosages of opioid medicines without effective pain relief. However, no studies in the U.K. have looked at the proportion of patients who continue to receive opioids (for all conditions) in the long-term or at high dosages so we do not know how opioid use develops in the U.K. Research from other countries has also identified that long-term and high dose use is linked to patient characteristics such as patient demographics and psychological and physical comorbidities. For example, a prior history of depression has been found to increase the risk of long-term and high dose use. This is of concern as this may indicate that patients may be potentially medicating the depression with the opioid. This may not be the case in the U.K. due to key factors such as the structure of the health system, so the aim of this thesis was to see if this phenomenon could potentially be occurring in the U.K. Methods This thesis was a retrospective observational cohort study of patients receiving opioid medicines for non-cancer conditions using data from a U.K. derived primary care database, the clinical practice research datalink (CPRD). Patients were included in the study if they received a prescription for opioid medication at any point in the year 2009 and followed, where possible to January 2015 (though data was collected for baseline variables prior to 2009). This thesis consists of a series of longitudinal analyses that attempt to define and describe the probability of long-term use and proportion of patients who receive high dosages in the U.K and seeks to understand how baseline characteristics (such as having a comorbid condition occurring before opioid use starts) affect the probability of long-term and high dose use. Competing risks methods were used to calculate the probability of continuation of opioid medicines (using death as a competing risk) and to determine long-term use. Cox regression models were used to determine whether baseline factors (such as prior antidepressant use) were associated with discontinuation of long-term use. Calculation of odds ratios were used to predict whether baseline characteristics predicted high dose use. Cox regression was also used to predict time to discontinuation of high dose use. Results In the U.K., 10.58% of patients received opioid medicines to treat non-cancer pain in the year 2009. Of the non-cancer patients included in the study, 41.41% were patients who received opioids in the six months prior to 2009 and the remaining were new users of opioid medicines. In the new user opioid group, 5.75% continued to be prescribed opioids for at least one year. When including new and existing users of opioid medicines, one in thirty people in the U.K. population who started opioids for non-cancer pain in 2009 were continuously prescribed opioids for a full year. Patients who were female, received an antidepressant before opioid use started and were in the youngest age category were more likely to continue opioid use past 2 years. The probability of continuing to take opioid medicines is higher in patients who have been receiving opioids for longer and are on higher dosages; in patients who had received over 10mg OMEQ for over two years, over half of patients continued to receive prescriptions for opioid medicines for the five year period study after 2009. In the U.K. population, one in a hundred opioid medicine users were prescribed a high dose (estimated dosage received >120mg oral morphine equivalents per day for at least 91 days) for non-cancer pain in their first 91 days of use in the year 2009. Patients receiving high dosages were likely to be receiving multiple opioid drug types and to receive preparations with multiple release profiles. In new users of opioid medication, the odds of high dose use were increased in patients who were younger (aged 18-49 years), had 3 or more comorbidities or were in receipt of an antidepressant or benzodiazepine and/or anti-anxiety drug before or after opioid use started. In new and existing users of opioid medicines, patients who were receiving high dosages were more likely to be diagnosed or be recorded with symptoms of depression or anxiety and to have been prescribed an antidepressant or benzodiazepine and/or other anti-anxiety drug in the youngest age group compared to the older age groups. Of the patients that were prescribed high dosages of opioid medicines for at least 91 days, 37.64% of patients did not have a second consecutive high dose quarter due to death or stopping high dose use. Almost one in five patients who had a high dose quarter continued to have a high dose for the next three years (22.98%). Older patients, patients prescribed weak opioids and/or tramadol discontinued high dose use at a faster rate than younger patients. Conclusion Both high dose and long-term use were found to be associated with a prior prescribing of antidepressants before opioid use started, suggesting that in the U.K. psychological comorbidities are associated with continued and high dose opioid use. Further work is required to measure outcomes within these groups and to understand the care that these patients have already received. Most patients who start opioid medicines in the U.K. stop taking them in their first year of use. However, of those who continue use past two years, a large proportion continue for the full five year period. Similarly, only a small proportion of patients receive high dosages of opioid medicines but once this use is established, many patients have a high probability of continuation. Further work should be undertaken to facilitate effective review of these patients in practice.
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Niebuhr, Nina Isabelle [Verfasser], and Joao [Akademischer Betreuer] Seco. "Biological Dose Accumulation in Image-guided Radiotherapy / Nina Isabelle Niebuhr ; Betreuer: Joao Seco." Heidelberg : Universitätsbibliothek Heidelberg, 2021. http://d-nb.info/1224684508/34.
Повний текст джерела
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Alticozzi, Lucio. "Radiotherapy with scanning carbon ion beams: biological dose analysis for partial treatment delivery." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10428/.
Повний текст джерелаАнотація:
L’uso di particelle cariche pesanti in radioterapia prende il nome di adroterapia.
L’adroterapia permette l’irraggiamento di un volume bersaglio minimizzando il danno ai tessuti sani circostanti rispetto alla radioterapia tradizionale a raggi X. Le proprietà radiobiologiche degli ioni carbonio rappresentano un problema per i modelli radiobiologici a causa della non linearità della loro efficacia biologica. In questa tesi presenteremo gli algoritmi che possono essere usati per calcolare la dose fisica e biologica per un piano di trattamento del CNAO (Centro Nazionale Adroterapia Oncologica).
Un caso di particolare interesse è l’eventualità che un piano di trattamento venga interrotto prima del dovuto. A causa della non linearità della sopravvivenza cellulare al variare della quantità di dose ricevuta giornalmente, è necessario studiare gli effetti degli
irraggiamenti parziali utilizzando algoritmi che tengano conto delle tante variabili che caratterizzano sia i fasci di ioni che i tessuti irraggiati.
Nell'ambito di questa tesi, appositi algoritmi in MATLAB sono stati sviluppati e implementati per confrontare la dose biologica e fisica assorbita nei casi di trattamento parziale.
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Davidson, Matthew Allen. "Irradiators for measuring the biological effects of low dose-rate ionizing radiation fields." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/76941.
Повний текст джерелаАнотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references.
Biological response to ionizing radiation differs with radiation field. Particle type, energy spectrum, and dose-rate all affect biological response per unit dose. This thesis describes methods of spectral analysis, dosimetry, biological assays, and mathematical modeling for determining the relative biological response for low dose-rate fields. The spatial dimensions of optically stimulated luminescence dosimeters make them ideal for measuring dose at a specific location. However the response of these dosimeters varies with photon energy. A method is presented for measuring dose delivered by several fields with photon energies less than 60 keV using these optically-stimulated luminescence dosimeters. This method is confirmed using an ion chamber dosimeter and computer simulation. The construction of 24Am irradiators for tissue culture and animal experiments using this dosimetry method is also described. The results of tissue culture experiments performed using these irradiators are presented, and the relative biological effectiveness (RBE) is determined for two fields with approximately equal dose-rates produced by shielding 24Am foil sources with aluminum and polyethylene. Biological effects can result from single instances of energy deposition within a cell or from the combination of separate instances, but at low dose-rates biological repair mechanisms reduce the probability of effects resulting from the combination of separate instances. At a sufficiently low dose-rate the effects due to combination of separate instances are negligible. A model of low dose-rate energy deposition within a cell nucleus was developed to determine this doserate. In this model the proportion of biological effects due to single instances of energy deposition within a cell nucleus is described in terms of the DNA repair rate of the biological 'system and the dose-rate and lineal energy transfer of the radiation field. This model also describes the projection of RBE values for fields with dose-rates below this threshold.
by Matthew Allen Davidson.
S.M.
13
Liebesny, Paul Hancock. "Single-dose growth factor treatments to enhance cell recruitment and neotissue integration in an augmented microfracture cartilage repair model." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104225.
Повний текст джерелаАнотація:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biological Engineering, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 198-215).
Focal cartilage defects caused by joint injury have a limited capacity to self-repair, and if left untreated, can lead to the early onset of osteoarthritis. The current gold standard of care, microfracture surgery, induces an endogenous repair response, but typically results in poorly integrated fibrocartilage, rather than native hyaline cartilage. The objective of this thesis was to test the hypothesis that a self-assembling peptide hydrogel functionalized with chemotactic and pro-anabolic growth factors and placed into the defect during surgery could induce migration of endogenous progenitor cells into the repair tissue. Since these progenitors are naturally accessed during microfracture surgery, clinical translation of this approach could ultimately steer repair to a more hyaline-like response. Poor cartilage repair is believed to be the result of an insufficient number of progenitor cells at the defect site. We hypothesized that the addition of a single dose combination of chemotactic growth factors (such as platelet derived growth factor-BB (PDGF-BB), transforming growth factor-P 1 (TGF-[beta]1), and heparin-binding IGF-l (HB-IGF-1)) premixed into a hydrogel scaffold could stimulate bone-marrow progenitor cell migration into the hydrogel. A novel 3D gel-to-gel migration assay, using (KLDL)₃ self-assembling peptide gels, demonstrated that the combination of PDGF-BB and TGF-[beta]1 induced significant migration into the gel compared to growth-factor free controls. Importantly, these growth factors were retained in the hydrogel and exhibited a slow release over 1-2 weeks. We also hypothesized that a brief enzymatic pre-treatment of the defect site could release proteoglycans from the walls of the surrounding native cartilage in a controlled manner, and thereby create space for newly synthesized repair tissue to anchor and integrate with this adjacent host cartilage. We used an in vitro model in which a cylindrical annulus of native cartilage was pre-treated with trypsin over a 2-minute period and then filled with a chondrocyte-seeded (KLDL) ³ hydrogel ftnctionalized with pro-anabolic HB-IGF-I that had been premixed into the gel. (This procedure was deemed to be clinically tractable by collaborating equine surgeons now using this approach in parallel animal studies.) Trypsin pre-treatment depleted proteoglycan content of adjacent cartilage in a controlled manner, and HB-IGF-l was found to be delivered to the surrounding cartilage from the peptide gel. HB-IGF-I was found to stimulate matrix biosynthesis both in the surrounding cartilage and the chondrocyte-seeded KLD scaffold, and to enhance mechanical integration. We further explored the uptake and diffusive transport properties of HB-IGF-l into cartilage motivated by the need to understand the pharmacokinetics of delivery from the repair construct to surrounding cartilage. The positively charged heparin-binding domain of HB-IGF-l results in high uptake into cartilage, making it an effective method of delivering the pro-anabolic attributes of IGF-1, which in its native form would be rapidly cleared from the joint. The observed high and rapid uptake of HB-IGF-l into cartilage will enable characterization of dosing for HB-IGF-l delivery to cartilage by either intra-articular injection or from implanted hydrogel scaffolds. In summary our results show that of (KLDL)₃ peptide hydrogel scaffolds can foster growth-factor induced progenitor cell migration to increase progenitor cell recruitment into a cartilage defect. Thus, the use of a peptide gel premixed with PDGF-BB and HB-IGF-l to enhance progenitor migration into the scaffold, combined with a trypsin pre-treatment to help promote subsequent integration, is a promising strategy towards improving integrative repair. The combination of these approaches is currently being tested in an in vivo rabbit model.
by Paul Hancock Liebesny.
Ph. D.
14
Pritz, Jakub. "Biological Effective Dose (BED) Distribution Matching for Obtaining Brachytherapy Prescription Doses & Dosimetric Optimization for Hybrid Seed Brachytherapy." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3298.
Повний текст джерелаАнотація:
Radioactive seed implant brachytherapy is a common radiotherapy treatment method for prostate cancer. In current clinical practice, a seed consists of a single isotope, such as 125I or 103Pd. A seed containing a mixture of two isotopes has been proposed for prostate cancer treatment. This study investigates a method for defining a prescription dose for new seed compositions based on matching the biological equivalent dose (BED) of a reference plan.
Ten prostate cancer cases previously treated using single isotope seeds (5 using 125I seeds and 5 using 103Pd seeds) were selected for this study. Verification of the method was done by calculating prescription doses for 103Pd and 125I seeds. A prescription dose for a 50/50 hybrid seed was calculated. Number and location of seeds remained invariant within each case. The BED distributions for hybrid and single isotope seed plans were generated and matched to the BED distribution generated off of the optimized plans.
For the 125I isotopes, the dose necessary to cover 90% of the prostate with a BED of 110 Gy is 145 Gy. For the same BED coverage, the dose for 103Pd and 50/50 hybrid seed is 120 Gy and 137 Gy respectively.
A method is introduced for obtaining prescription doses for new brachytherapy sources. The method was verified by obtaining doses for 125I and 103Pd isotopes which match clinical prescription doses. The method developed is robust enough to calculate prescription doses in any region of interest, for any seed type, and for any isotope as long as the BED coverage remains invariant with respect to the treatment plan.
Numerical calculations were performed to derive analytical conversions of total dose to BED for 50/50, 75/25 and 25/75 hybrid seeds. These analytical conversions are faster than the original numerical methods employed allowing for real-time BED optimization for hybrid seeds.
Varying seed distribution was seen not to influence the analytical conversions. It was observed that when total dose remained invariant while individual isotope contributions varied, the value of BED varied. The BED variance was seen to be the smaller at larger BED values (~2% at 100 Gy).
Using the conversions derived in this paper, BED based optimization for hybrid seeds are now performable. However, these conversions should only be used in high dose regions due to high uncertainty in the low regime.
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Kim, Jongsoon. "Dose calculation methodology for irradiation treatment of complex-shaped foods." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1899.
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Hall, Susan Claire. "The C₃H 10T1/2 mouse embryo transformation assay : the role of radiation quality and dose-rate." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279005.
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Broadhead, Dawn. "Large scale entrance surface dose survey and organ dose measurements during diagnostic radiology using the Harshaw 5500 and 6600 TLD systems." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366517.
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Zheng, Yifeng. "Studies on biological activities of low dose of phenethylamine from hot water extract of Chlorella pyrenoidosa." Doctoral thesis, Kyoto University, 2020. http://hdl.handle.net/2433/259745.
Повний текст джерелаАнотація:
京都大学0048
新制・課程博士
博士(農学)
甲第22849号
農博第2432号
新制||農||1082(附属図書館)
学位論文||R2||N5309(農学部図書室)
京都大学大学院農学研究科応用生物科学専攻
(主査)教授 佐藤 健司, 教授 澤山 茂樹, 教授 菅原 達也
学位規則第4条第1項該当
Doctor of Agricultural Science
Kyoto University
DGAM
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Short, Susan Christine. "New methods to overcome radioresistance." Thesis, Institute of Cancer Research (University Of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313289.
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SILVA, MARCIA A. da. "Dosimetria biologica em protecao radiologica. Elaboracao de curvas dose-reposta para o Cosup60 e Cssup137." reponame:Repositório Institucional do IPEN, 1997. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10674.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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OLIVEIRA, ELAINE M. de. "Avaliacao do efeito biologico da radiacao beta do sup[90]Sr em celulas sanguineas humanas e elaboracao de curva dose resposta." reponame:Repositório Institucional do IPEN, 2000. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10815.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Chanrion, Marie-Anne. "Study and development of physical models to evaluate biological effects of ion therapy : the study of local control of prostate cancer." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10304/document.
Повний текст джерелаАнотація:
La radiothérapie externe est un traitement anticancéreux locorégional efficace et curatif. Néanmoins, il y a toujours des malades qui meurent de tumeurs locales non-contrôlées. Les nouvelles techniques en radiothérapie visent toujours à trouver un moyen d'augmenter la dose à la tumeur tout en réduisant au minimum la dose aux tissus sains adjacents. Une des dernières techniques innovantes est l'hadronthérapie par ions carbone. Ces dix dernières années ont vu augmenter le nombre de nouveaux centres d hadronthérapie dans le monde avec des faisceaux d'ions carbone, forts des résultats promettant des projets pilotes Berkeley (USA), Chiba (Japon) et Darmstadt (Allemagne). Les avantages théoriques des ions carbone sont: une meilleure balistique et une meilleure efficacité dans la destruction des cellules tumorales. Ainsi cette technique a le potentiel d'augmenter le contrôle des tumeurs, particulièrement pour celles inopérables et radiorésistantes. Les effets biologiques varient le long de la trajectoire des ions de haut TEL (Transfert d'´Énergie Linéique) comme les ions carbone. Ainsi des modèles radiobiologiques sont nécessaires pour quantifier les effets biologiques. Il existe plusieurs modèles radiobiologiques qui reposent sur des approches et des approximations théoriques différentes. Ces modèles ont été développés au sein de chacune des institutions où se déroulaient les projets pilotes. Au stade actuel des connaissances, il semble peu probable d'atteindre une rapide convergence des résultats produits par ces différents modèles. Parmi les modèles radiobiologiques utilisés en clinique, il y a le Local Effect Model (LEM), développé en Allemagne et implémenté dans les systèmes de planification de traitement certifiés CE, le modèle de la National Institute of Radiological Science (NIRS), employé dans les centres japonais d'hadronthérapie possédant un système d'irradiation passif, et le Microdosimetric Kinetic Model (MKM) employé dans les centres japonais d'hadronthérapie possédant un système d'irradiation actif en mode pencil beam scanningExternal beam radiotherapy (EBRT) is a therapy technique aiming at treating locoregional tumors with high efficiency. However, many tumors remain uncontrolled. Newest EBRT techniques always aim at increasing the dose to the tumor while sparing the surrounding healthy tissues. Carbon-ion beam therapy is one of these promising techniques. The number of clinical centres offering carbon-ion beam radiotherapy has been increasing over the world for the last decade. This keen interest spread after very promising results from pilot projects at Berkeley (USA), Chiba (Japan) and Darmstadt (Germany). The theoretical advantages of carbon-ionsare better spatial selectivity in dose deposition and better efficiency in cell killing. They have thus the potential to increase the control of tumors, particularly for unresectable radioresistant tumors. In high linear-energy-transfer (LET) radiations, such as carbon-ion beams, biological effects vary along the ion track, hence, to quantify them, specific radiobiological models are needed. There exist several radiobiological models based on very different theoretical approaches and approximations. They were created and improved in each of the pilot institutions. At the current state of knowledge, no convergence between the model results seems to be possible in the very near future. Clinically employed radiobiological models are the Local Effect Model (LEM) developed in Germany and implemented in CE-certified treatment planning systems, the National Institute of Radiological Science (NIRS) model employed in Japanese centres with passive beam delivery systems and the microdosimetric kinetic model (MKM) in Japanese centres with active scanning beam delivery systems
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Rüegsegger, Martin. "The dose-dependent systemic availability of prednisone, one reason for the reduced biological effect of alternate-day prednisone /." [S.l : s.n.], 1985. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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24
Knudsen, Erik S., Jack Hutcheson, Paris Vail, and Agnieszka K. Witkiewicz. "Biological specificity of CDK4/6 inhibitors: dose response relationship, in vivo signaling, and composite response signature." IMPACT JOURNALS LLC, 2017. http://hdl.handle.net/10150/625360.
Повний текст джерелаАнотація:
Recently developed potent and selective CDK4/6 inhibitors fall into two classes based on structure and toxicity profiles in clinical studies. One class, exemplified by palbociclib and ribociclib, exhibits neutropenia as a dose-limiting toxicity and requires discontinuous dosing. In contrast, the structurally distinct CDK4/6 inhibitor abemaciclib is dosed continuously, and has diarrhea and fatigue as dose-limiting toxicities. In preclinical models, palbociclib has been extensively studied and induces cell cycle inhibition in an RB-dependent manner. Thus far, abemaciclib has been less extensively evaluated. We found that abemaciclib cell cycle inhibitory activity is RB-dependent at clinically achievable concentrations. Abemaciclib elicited potent suppression of RB/E2F regulated genes associated with prognosis in ER-positive breast cancer. However, unlike palbociclib, at 250nM-1 mu M doses abemaciclib induced cell death in RB-deficient cell lines. This response was associated with a rapidlyinduced multi-vacuolar phenotype indicative of lysosomal membrane permeabilization that could be ameliorated with chloroquine. This event was not a reflection of inhibition of other CDK family members, but could be recapitulated with CBX4945 that inhibits casein and DYRK/HIPK kinases. To determine if these "off-target" features of abemaciclib were observed in vivo, mice harboring matched RB-positive and negative xenografts were treated with palbociclib and abemaciclib. In vivo, all of the apparent activity of abemaciclib was RB-dependent and strongly elicited suppression of cell cycle regulatory genes in a fashion markedly similar to palbociclib. Using gene expression data from cell lines and tumors treated with abemaciclib and palbociclib a composite signature of response to CDK4/6 inhibition was developed that included many genes that are individually required for tumor cell proliferation or viability. These data indicate that while abemaciclib and palbociclib can exert distinct biological and molecular effects, there are common gene expression features that could be broadly utilized in measuring the response to CDK4/6 inhibition.
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Shim, Grace. "Influence of Individual Radiosensitivity on Biological Responses to Ionizing Radiation Dose Estimation and the Role of Telomere Maintenance." Thesis, Paris 11, 2015. http://www.theses.fr/2015PA11T050/document.
Повний текст джерелаАнотація:
L'exposition aux rayonnements ionisants est une composante inévitable de la vie moderne. Il est bien établi qu'il existe une grande variabilité inter-individuelle de la radiosensibilité chez les individus sains et chez des patients atteints de cancer. Cependant, les mécanismes impliqués dans l'hétérogénéité des réponses biologiques radio-induites ne sont pas encore bien compris, et une approche biologique permettant d’établir de façon fiable le niveau de radiosensibilité reste à développer. Dans cette thèse, nous avons étudié l'ampleur et l'impact de la radiosensibilité individuelle chez les individus sains dans les contextes de dosimétrie d'urgence et de radiothérapie. Nous avons également examiné les différents rôles des télomères dans la prédiction de la radiosensibilité individuelle et des risques pour la santé humaine à long terme (spécifiquement, en ce qui concerne les maladies cardiovasculaires et/ou les cancers) après irradiation. Tout d'abord, dans le contexte de la dosimétrie dans le cas d'une situation d'urgence (lorsqu’il est nécessaire d’estimer rapidement la dose d’irradiation reçu par un individu), nous avons démontré que l'impact de la radiosensibilité individuelle peut être négligeable en utilisant des mesures globales de fluorescence de γH2AX via cytométrie en flux dans des fibroblastes humains et des lymphocytes à 4 heures après exposition ; cette méthode peut être un outil de biodosimétrie efficace et rapide qui peut aider au tri des personnes irradiées dans une situation d'urgence basées sur les niveaux individuels d'exposition. Dans un second temps, nous avons étudié l'ampleur et l'influence de la radiosensibilité individuelle sur l'induction d'aberrations chromosomiques après une irradiation de 2 Gy de rayons γ, correspondant à une fraction de radiothérapie conventionnelle, dans les lymphocytes d'individus sains. Pour ces analyses, nous définissons la radiosensibilité individuelle par rapport à la fréquence des cassures double-brin (CDB) radio-induite, qui ont été calculées à partir de la quantification des aberrations chromosomiques visualisées par hybridation in situ des télomères et centromères (TC-FISH). Ce marquage améliore et simplifie la technique « gold standard » de dosimétrie biologique (la quantification des chromosomes dicentriques). Nous avons également estimé la radiosensibilité individuelle à l’irradiation carbone, ions lourds utilisés en radiothérapie, et l'efficacité biologique relative (EBR) des ions carbone par rapport à une irradiation γ. Nous avons fourni des courbes dose-réponse pour ces deux types d’irradiations en fonction de la fréquence des CDB radio-induite par exposition à une gamme de doses. De plus, nous avons estimé l'EBR d'un troisième type de rayonnement également utilisé en radiothérapie d'ions lourds (protons) par rapport à une irradiation γ, et nous avons comparé la radiosensibilité individuelle de ces trois types d'irradiation avec énergies différentes. Ensuite, nous avons évalué les rôles des télomères et de leur maintien pour la prédiction de la radiosensibilité individuelle. Nous avons constaté que la longueur moyenne des télomères, en combinaison avec leurs modifications radio-induites, peuvent être un bon prédicteur de la radiosensibilité individuelle. Enfin, nous avons montré comment les télomères pourraient être liés à des risques sanitaires à long terme après une irradiation: nous avons démontré que le raccourcissement des télomères pouvait être un nouveau facteur de prédiction de maladies cardiovasculaires après radiothérapie, et nous avons discuté par la suite, les télomères comme des acteurs clés dans le processus de cancérogenèse radio-induite. En conclusion, nous proposons un modèle présentant la façon dont les télomères pourraient jouer un rôle crucial dans ces deux pathologies radio-induite, et nous délibérons des relations entre le maintien des télomères, les effets biologiques radio-induites, et la radiosensibilité individuelleExposure to ionizing radiation (IR), from both natural and man-made sources, is an inevitable part of modern life. It is well established that there are considerable inter-individual variations in sensitivity to IR among healthy individuals and cancer patients. However, the mechanisms involved in the heterogeneity of biological responses to IR are not well understood, and a reliable biodosimetric and clinical approach to measure and rank radiosensitivity remains to be established. In this thesis, we study the extent and impact of individual radiosensitivity in healthy individuals in the contexts of emergency dosimetry and radiotherapy, and we explore the roles of telomeres in the prediction of individual radiosensitivity and long-term human health risks following IR exposure (specifically, cardiovascular diseases and/or cancer). First, in the context of dosimetry in the event of an emergency situation (when rapid dose estimates of each individual in an irradiated population are needed), we demonstrate that the impact of individual radiosensitivity can be negligible using global cellular measurements of γH2AX fluorescence via flow cytometry in human fibroblasts and lymphocytes at 4 hours post-irradiation; this method could be an effective and rapid biodosimetry tool that can aid in the medical triage of irradiated individuals in an emergency setting based on individual levels of exposure. Second, we study the extent and influence of individual radiosensitivity on the induction of chromosomal aberrations following a routinely administered dose of 2 Gy during conventional fractionated photon radiotherapy (γ-rays) in lymphocytes of healthy individuals. For these analyses, we define individual radiosensitivity based on the frequency of IR-induced DNA double strand breaks (DSBs), which were calculated from the scoring of chromosomal aberrations visualized with telomere/centromere-fluorescence in situ hybridization (TC-FISH). This TC-FISH staining of metaphasic chromosomes enhances the “gold standard technique” of biodosimetry (the dicentric chromosome assay) with the visualization of telomeres and centromeres and thereby provides improved simplicity and sensitivity to the classical cytogenetic assay. We also compare individual radiosensitivity following γ-irradiation to that following carbon irradiation, an up-and-coming ion species currently being used in heavy ion radiotherapy. We provide dose response curves for both γ- and carbon irradiations based on the calculated frequency of IR-induced DNA DSBs at a range of doses, and estimate the relative biological effectiveness (RBE) of carbon irradiation relative to γ-irradiation. We then estimate the RBE of a third type of IR also frequently used in heavy ion radiotherapy (proton beams) in comparison to γ-irradiation, and compare individual radiosensitivity to each of these three types of IR with different IR energies. Third, we evaluate the roles of telomeres and telomere maintenance in the prediction of individual radiosensitivity; we find that inherent mean telomere length in combination with the IR-induced change in mean telomere length may be a strong predictor of individual radiosensitivity. Finally, we show how telomeres could be linked to long-term health risks following IR exposure: we demonstrate that telomere shortening could be a new prognostic factor for cardiovascular disease following radiotherapy, and discuss how telomeres could be key players in the process of radiation-induced carcinogenesis. In conclusion, we deliberate the relationships between telomere maintenance, radiation effects, and individual radiosensitivity, and propose a model of how telomeres could play crucial roles in the development of cardiovascular diseases and the process of IR-induced carcinogenesis
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Nyholm, Tufve. "Verification of dose calculations in radiotherapy." Doctoral thesis, Umeå : Umeå University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1931.
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Le, Roux Jacques. "The analysis of radiation-induced micronuclei in peripheral blood lymphocytes for purpose of biological dosimetry." Master's thesis, University of Cape Town, 1995. http://hdl.handle.net/11427/27038.
Повний текст джерелаАнотація:
In the investigation of radiation accidents, it is of great importance to estimate the dose absorbed by exposed persons in order to plan their therapy. Although occasionally in these situations physical dose measurements are possible, most often biological methods are required for dose estimation. The aim of this investigation was to assess the suitability of the cytokinesis blocked (CB) micronucleus assay as a biodosimetric method using lymphocytes irradiated in vivo. The approach adopted to achieve this was to estimate whole body doses by relating micronuclei yields in patients undergoing radiotherapy treatment with an in vitro radiation dose-response curve. These biologically derived estimates were then compared with the corresponding doses obtained by physical measurement and calculation. As a first approach a study was performed of the in vitro dose-response of gamma-ray induced micronuclei following cytokinesis-block in the lymphocytes of peripheral blood samples obtained from 4 healthy donors. The results indicated that the distribution of the induced micronuclei were overdispersed. Furthermore, a linear dose-response relationship was established when a curve was fitted to the data by an iteratively reweighted least squares method. By means of an analysis of covariance it was demonstrated that this result is in agreement with the dose-response relationships found by various other workers (Fenech et al., 1985; Fenech et al., 1986; Fenech et al., 1989; Balasem et al., 1992, and Slabbert, 1993). To assess the suitability and accuracy of dose assessment using the CB micronucleus assay for in vivo exposure of lymphocytes, blood samples obtained from 8 patients undergoing radiotherapy before, during and after treatment were examined. The physical doses of these patients were determined according to conventional radiation treatment plans and cumulative dose-volume histograms. The dose-volume histograms permitted calculation of integral doses and subsequently the estimate of equivalent whole-body doses. The results of the CB micronucleus assay applied to peripheral blood lymphocytes of 6 patients undergoing fractionated partial-body irradiation showed a dose-related increase in micronucleus frequency in each of the patients studied. This demonstrated that micronuclei analysis may serve as a quantitative biological measure of such exposures. The pooled data of these patients compared to the pooled data of the healthy donors show that there was no statistically significant difference between in vitro and in vivo results, however a slightly lower induced micronuclei frequency was observed after in vivo exposure. When the biological dose estimates for equivalent whole-body doses obtained from the in vitro dose response curve were compared with calculated physical doses, it was found that: biologically estimated dose = 0.936 physical dose. However, there was inadequate statistical evidence to discard the hypothesis that the gradient of the equation was equal to one. Therefore, the analysis of micronuclei induced in lymphocytes in vivo yields highly quantitative information on the equivalent whole-body dose. The negative binomial method was used for analysing the micronucleus data from two patients who received single, relatively larger tumour doses of 10 Gy each, with the objective to obtain estimates of the exposed body fraction and the dose to this fraction. The dose estimates to the irradiated volume were found to be within 30% of the physical tumour dose. The irradiated volume estimates seemed to be higher than the physically calculated volumes but by discarding the correction for the loss of cells due to interphase death the agreement was good between the physically and biologically determined integral doses. This study has revealed that the CB micronucleus assay appears to offer a reliable, consistent and relatively rapid biological method of whole body dose estimation. It is recognised that further corroborative work using the techniques described in this thesis is required for estimating localized exposure.
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CLARO, THIAGO R. "Desenvolvimento de um código computacional de apoio ao cálculo de dose interna para radionuclídeos de interesse do IPEN." reponame:Repositório Institucional do IPEN, 2011. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10056.
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Preston, Rika. "Measuring DNA damage and repair as possible biological markers for long-term, low-dose chemical exposure in hairdressers / R. Preston." Thesis, North-West University, 2008. http://hdl.handle.net/10394/2326.
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Kubs, Fleur. "Apport de la modulation d'intensité et de l'optimisation pour délivrer une dose adaptée aux hétérogénéités biologiques." Thesis, Vandoeuvre-les-Nancy, INPL, 2007. http://www.theses.fr/2007INPL066N/document.
Повний текст джерелаАнотація:
Les progrès en imagerie fonctionnelle ouvrent de nouvelles perspectives dans la délimitation des volumes cibles en radiothérapie. Il est envisagé d’adapter les doses d’irradiation sur l’activité tumorale et de réaliser une escalade de dose. Nos objectifs étaient caractériser la détectabilité en TEP, en quantifiant les incertitudes de contour du GTV, de mettre en place la géométrie appropriée, d’évaluer l’impact dosimétrique de ce nouveau protocole et de vérifier la bonne délivrance de cette irradiation. 3 fantômes originaux et 2 fantômes virtuels avec les 3 niveaux de dose recherchés ont été spécialement conçus. Le diamètre de 1cm pour le niveau 3 a pu être atteint. Une escalade de 20Gy a été possible. L’impact dosimétrique sur deux cas réels était satisfaisant. Les tolérances cliniques ont été respectées. Toute la chaîne de traitement a été évaluée et validée. Cependant de telles doses doivent être évaluées avec précaution avant d’être prescrites et des progrès sont attendus en imagerieThe progress in functional imaging opens new perspectives in the delineation of target volumes in radiotherapy. We can intend to adapt the irradiation doses on the tumor activity and to perform a dose escalation. Our objectives were (i) to characterize the TEP thresholding, by quantifying the uncertainties of the target volume contour, (ii) to set up the geometry suited, (iii) to estimate the dosimetric impact of this new protocol and (iv) to verify that dosimetry is perfectly distributed. 3 original phantoms and 2 virtual phantoms containing 3 dose levels were specially created. The diameter of 1cm for the 3rd level was able to be reached. A dose escalation of 20Gy was possible. The dosimetric impact on two real cases was suitable. The clinical tolerances were respected. So all the treatment process was estimated and validated. However such doses should be carefully estimated before being prescribed clinically and progress is also expected in imaging
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Allen, Janet Elizabeth. "Radon, '2'1'0Pb-supported '2'1'0Po and factors affecting dose to adult and fetal bone marrow." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310604.
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Leidel, Jason M. "In vitro partial-body dose assessment using a radiation responsive protein biomarker /." Download the thesis in PDF, 2005. http://www.lrc.usuhs.mil/dissertations/pdf/Leidel2005.pdf.
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LIMA, MARINA F. "Proposição de modelos cinéticos e alométricos para a dosimetria de radiofármacos marcados com lantanídeos." reponame:Repositório Institucional do IPEN, 2012. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10181.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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SZAROTA, ROSA M. "Influencia da radiacao ionizante sobre o Trypanosoma cruzi." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11380.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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SANCHEZ, ANDREA. "Projeto e confecção de simuladores oftálmicos para aplicações clínicas." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11431.
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IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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SILVA, MARCIA A. da. "Efeito citogenetico do sup(153) Sm-EDTMP em linfocitos perifericos de pacientes com cancer metastatico." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10924.
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IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Kamp, Florian [Verfasser], Jan J. [Akademischer Betreuer] Wilkens, and Franz [Akademischer Betreuer] Pfeiffer. "Uncertainties in biological dose response models and their integration in treatment planning of carbon ion therapy / Florian Kamp. Gutachter: Jan J. Wilkens ; Franz Pfeiffer. Betreuer: Jan J. Wilkens." München : Universitätsbibliothek der TU München, 2015. http://d-nb.info/1069127795/34.
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38
Joly, Baptiste. "Optimisation de la résolution temporelle en Tomographie par Emission de Positons dédiée au contrôle de dose en hadronthérapie." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2010. http://tel.archives-ouvertes.fr/tel-00505129.
Повний текст джерелаАнотація:
L'hadronthérapie est une technique de traitement de tumeurs basée sur l'irradiation par un faisceau d'ions. La distribution de dose peut être contrôlée durant le traitement par plusieurs techniques dont la tomographie par émission de positons (TEP). En effet, les collisions nucléaires entre les ions incidents et le milieu cible produisent des émetteurs bêta+, dont la distribution spatiale est corrélée à la dose. Toutefois, cette application est pénalisée par une faible activité bêta+, une forte activité parasite, et nécessite une reconstruction rapide. La mesure de temps de vol semble un facteur crucial pour rendre cette technique faisable. Ce travail part d'un concept d'électronique frontale basé sur l'échantillonnage et le traitement numérique des signaux de détecteurs pour reconstruire l'énergie et le temps. Les limites statistiques à la résolution temporelle déterminées par le processus de scintillation sont examinées théoriquement. Un dispositif expérimental à deux détecteurs à scintillation en coïncidence est utilisé pour tester différents algorithmes : des discriminateurs (à seuil fixe, à fraction constante) et des filtres numériques (moindres carrés, optimal, passe-bas). Leurs performances temporelles sont similaires, excepté le filtre des moindres carrés, inadapté au bruit non-stationnaire du signal de scintillation. Plusieurs scintillateurs et configurations sont testés, confirmant l'importance du rendement lumineux, des constantes de temps de scintillation et de la réponse du photodétecteur. Un détecteur à base de photodiode à avalanche est testé dans le cadre de la construction d'un démonstrateur multivoies, qui sera utilisé pour des tests en faisceau.
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PEREIRA, MARCO A. G. "Avaliacao dos espectros primarios e secundarios da radiacao X em objetos simuladores para energias utilizadas em diagnostico medico." reponame:Repositório Institucional do IPEN, 2004. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11241.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
40
Watanabe, Tsubasa. "L-phenylalanine preloading reduces the 10B(n,α)7Li dose to the normal brain by inhibiting the uptake of boronophenylalanine in boron neutron capture therapy for brain tumours". 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225452.
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Zhang, Pengcheng. "Optimisation de la planification en radiothérapie prostatique et ORL." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S042/document.
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Ces travaux portent sur l'optimisation de la planification en radiothérapie prostatique et ORL. De façon à améliorer le calcul dosimétrique, la méthode de calcul de dose dite « Pencil beam » a d'abord été modifiée en considérant un système de coordonnées sphériques, en améliorant le mode de correction des hétérogénéités et en accélérant le calcul en effectuant les opérations de convolution grâce à la transformée de Fourier rapide. L'approche proposée a été comparée aux méthodes classiques en utilisant différents fantômes numériques. Cette évaluation a démontré la précision de la méthode proposée ainsi que l'accélération des calculs d'un facteur 40 par la méthode utilisant la transformée de Fourier, au prix toutefois d'une dégradation de la précision des résultats. Dans un second temps, l'incorporation de critères biologiques lors de l'optimisation du plan de traitement a été mise en œuvre à travers l'équivalent convexe du modèle NTCP (probabilité de toxicité des tissus sains) et son optimisation. L'évaluation de cette approche a été réalisée sur les données de dix patients traités pour un cancer de la prostate et a montré que la méthode proposée produit des planifications cliniquement satisfaisantes avec de meilleurs résultats en termes de toxicité prédite. Une méthode de compensation des incertitudes géométriques survenant lors du traitement a aussi été proposée, reposant sur une décomposition en séries de Taylor et un filtre de Butterworth. Son évaluation a montré son efficacité en termes de réduction des oscillations de haute fréquence ainsi que de présence de points chauds et froids. Enfin, dans un contexte de radiothérapie adaptative en ORL, une étude permettant d'identifier le scénario optimal de replanification, c'est-à-dire le nombre et les moments des replanifications, a été menée. Les critères de comparaison considérés reposaient sur le calcul de la dose cumulée reçue notamment par les parotides lors du traitement complet. L'efficacité des replanifications a ainsi été démontrée, avec par exemple une diminution du risque de toxicité de 9% pour le scénario optimal. Les perspectives de ce travail concernent la combinaison de ces méthodes dans un processus complet de planification pour évaluer leur impact dans un contexte cliniqueThis work focuses on the optimization of planning in prostate and head-and-neck radiation therapy. In order to improve the dose calculation, the Pencil Beam method was firstly modified by considering a spherical coordinate system, by improving the heterogeneities correction method and by accelerating the calculation by performing the convolution operations using the Fast Fourier Transform. The proposed approach was compared to conventional methods using different numerical phantoms. This evaluation demonstrated the accuracy of the proposed method and the acceleration of the calculations by a factor 40 by the method using the Fast Fourier Transform, but at the cost of deterioration in the accuracy of the results. In a second step, the incorporation of biological criteria in the optimization of the treatment plan has been implemented through an equivalent convex NTCP constraints and its optimization. The evaluation of this approach has been performed on the data of ten patients treated for prostate cancer and has shown that the proposed method produces clinically satisfactory plans with better results in terms of predicted toxicity. A method to compensate geometric uncertainties occurring during treatment has also been proposed, based on the expansion in series of Taylor and a Butterworth filter. Its evaluation has shown its effectiveness in reducing high-frequency oscillations as well as the presence of hot and cold spots. Finally, in the context of adaptive radiotherapy in head and neck, a study was conducted to identify the optimal scenario of replannings, i.e. the number and timing of replannings. The comparison criteria were based on the calculation of the cumulative dose received by the parotid during the whole treatment. The effectiveness of the replanning has been demonstrated, for example with a decreased risk of toxicity 9% for the optimal scenario. The perspectives of this work relate to the combination of these methods in a comprehensive planning process to assess their clinical impact
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MITAKE, MALVINA B. "Estudos bioquimico e farmacologico das crotaminas nativa e irradiada com radiacao gamma de sup(60)Co." reponame:Repositório Institucional do IPEN, 2000. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10819.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
43
Nilsson, Johan. "Accurate description of heterogeneous tumors for biologically optimized radiation therapy." Doctoral thesis, Stockholm : Division of medical radiation physics, Department of oncology-pathology, Stockholm University and Karolinska Institutet, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-311.
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MORENO, CAROLINA dos S. "Estudo do efeito radioprotetor do resveratrol." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9440.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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MELO, ANA M. M. de A. "Estudos dos efeitos da radiacao gama de sup60Co sobre larvas de Biomphalaria glabrata (Say,1818)." reponame:Repositório Institucional do IPEN, 1998. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9270.
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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
46
Szarota, Rosa Maria. "Influência da radiação ionizante sobre o Trypanosoma cruzi." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-15052012-112111/.
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A Doença de Chagas é um dos maiores problemas de saúde pública na América do Sul causando um elevado prejuízo à população. A despeito dos inúmeros esforços para o seu controle, a doença não tem cura e apresenta problemas científicos ainda não esclarecidos. Considerando-se que vários pesquisadores têm usado a radiação ionizante para modificar protozoários ou propriedades imunológicas de biomoléculas, neste trabalho foram estudados aspectos da resposta imunológica induzida em camundongos, resistentes e suscetíveis ao T. cruzi, utilizando formas irradiadas deste parasita. Doses baixas de radiação preservaram a capacidade reprodutiva e de invasão celular. Animais resistentes e suscetíveis, imunizados com os parasitas tratados por radiação, produziram anticorpos específicos. Após o desafio, os animais apresentaram baixa parasitemia, com exceção dos grupos imunizados com parasitas que receberam apenas altas doses de radiação. A seleção de formas tripomastigotas foi obtida irradiando-se os parasitas com baixas doses, o que promoveu aprimoramento da qualidade da resposta imune, a exemplo do que se observa quando da utilização de complemento. Estes dados evidenciam a importância da seleção das formas tripomastigotas para a imunização contra o T. cruzi e apontam a radiação ionizante como alternativa para este fim, uma vez que quando a seleção é feita utilizando-se complemento, depara-se com a dificuldade de sua remoção, colocando em risco o processo de imunização por introduzir substancias estranhas ao organismo.Chagas\'s disease is one of the major public health problems in South America, promoting high prejudice to the local population. Despite the massive efforts to control it, this disease has no cure and presents puzzling unsolved questions. Considering that many researchers have used ionizing radiation to modify protozoans or biomolecules, we investigated the immunological response aspects of susceptible and resistant mice using irradiated parasites. Low radiation doses preserved the reproductive and invasive capacities of the parasite. Both susceptible and resistant animals, after immunization with irradiated parasites produced specific antibodies. After a challenge, the animals presented low parasitaemia, excepting those immunized with the antigen irradiated with higher doses. Using low radiation doses, we were able to selectively isolate trypomastigotes, leading to an improvement in the quality of the immune response, as previously reported when performing complement system assays. These data highlight the importance of selecting trypomastigote forms for immunization against T. cruz; and point towards ionizing radiation as an alternative to achieve this selection, since when this procedure is performed using complement, the subsequent steps are impaired by the difficulties to remove this component from the system.
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SARMENTO, DANIELE M. "Avaliação dos níveis de radiação ambiental no laboratório de tomografia por emissão de pósitrons acoplada a tomografia computadorizada, microPET/CT." reponame:Repositório Institucional do IPEN, 2016. http://repositorio.ipen.br:8080/xmlui/handle/123456789/26611.
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O sistema microPET/CT é um importante equipamento utilizado nas pesquisas de imagem diagnóstica em pequenos animais. O radiofármaco mais usado nesta tecnologia é o fluordeoxiglicose marcado com flúor-18. Este estudo tem como objetivo efetuar o controle radiológico no laboratório de pesquisa microPET/CT do Centro de Radiofarmácia do IPEN-CNEN/SP, de forma a satisfazer tanto as normas nacionais como as recomendações internacionais. O laboratório está classificado pela equipe de radioproteção da instalação como área supervisionada, nas quais embora não seja obrigatória a adoção de medidas específicas de proteção e segurança, devem ser submetidas reavaliações regulares das condições do ambiente de trabalho. Visando assegurar a proteção radiológica dos trabalhadores diretamente envolvidos no manuseio do equipamento, realizou-se o monitoramento do local de trabalho e a avaliação do controle de dose individual. Inicialmente foi feito o monitoramento pré-operacional, isto é, o levantamento radiométrico no laboratório. Além disso, mediu-se nível de radiação externa nas instalações do laboratório e suas adjacências, por meio da colocação de nove dosímetros termoluminescentes (TL) de CaSO4:Dy, em locais previamente selecionados. Os indivíduos ocupacionalmente expostos foram avaliados mensalmente por meio do uso de dosímetros TL posicionados no tórax e por medidas de corpo inteiro, tomadas a cada seis meses. O período do estudo foi de dois anos, com início em abril de 2014. Para o controle do microPET/CT realizou-se testes de desempenho de acordo com o protocolo padrão do equipamento e em conformidade com a norma desenvolvida pela força tarefa para estudos com PET em animais Animal PET Standard Task Force. O presente estudo permitiu demonstrar que os níveis de radiação das áreas (estimativas de dose ambiente e dose efetiva), assim como a blindagem do equipamento estão adequados de acordo com os limites da exposição ocupacional. Ressalta-se a importância de se seguir rigorosamente os princípios de radioproteção, já que se trata de pesquisas com fontes radioativas não seladas.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
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Santos, Gustavo Souza. "Biomonitoramento das Baías de Guaratuba e Paranaguá através de biomarcadores de contaminação ambiental." reponame:Repositório Institucional da UFPR, 2013. http://hdl.handle.net/1884/29826.
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Resumo: Os estuários são muitas vezes referidos como o tipo de habitat mais degradado do mundo. São vulneráveis a diversas perturbações causadas por atividades humanas, incluindo a agricultura, a indústria, os assentamentos humanos, a pesca e as atividades portuárias. O estuário de Guaratuba é afetado principalmente pelo desenvolvimento das atividades agrícolas e pelas modificações hidrológicas provenientes da construção de barragens. Já o complexo estuarino de Paranaguá recebe regularmente escoamentos provenientes do Porto, de indústrias locais e atividades agrícolas, além do esgoto doméstico, o que acarreta numa variedade muito grande de substâncias químicas que diariamente entram neste ambiente. A fim de avaliar a qualidade da água nestes estuários, bem como os efeitos da sazonalidade na disponibilidade de xenobióticos, foram utilizados os seguintes biomarcadores: Etoxiresorufina-O-deetilase (EROD), Glutationa S-transferase (GST), Lipoperoxidação (LPO), Acetilcolinesterase (AChE), Metalotioneínas (MTs), Teste do micronúcleo písceo (TMP), Ensaio cometa, Ensaio de difusão do DNA, Histopatologia de fígado, além da análise de metais (As, Pb, Sn e Hg) no músculo e no fígado das espécies Cathorops spixii e Atherinella brasiliensis. Foram realizadas duas coletas (verão e inverno) em dois pontos de cada estuário. De acordo com os dados obtidos para os biomarcadores, tanto a baía de Guaratuba quanto a de Paranaguá são impactadas pela presença de xenobióticos, causando efeitos adversos a saúde das espécies pesquisadas. Os biomarcadores sugerem também que o aporte de xenobióticos nestes locais apresenta fontes diferentes, sendo as mais impactantes, as plantações ao redor da baía em Guaratuba e as atividades relacionadas ao porto em Paranaguá. A relação entre a sazonalidade e as respostas dos biomarcadores também foi avaliada, com os pontos mais internos das baías apresentando maiores variações para a espécie C. spixii. A contaminação por metais também foi evidenciada, sendo que o Hg foi mais encontrado em Guaratuba (relacionado a utilização de fertilizantes na agricultura) e o As em Paranaguá, que ocorre naturalmente na região, mas também tem fonte nas indústrias de fertilizantes. A presença destes metais pode estar relacionada a alterações na saúde dos peixes das baías. As espécies C. spixii e A. brasiliensis podem ser consideradas como bioindicadores adequados quando utilizamos a abordagem de biomarcadores, e são indicadas para futuros programas de monitoramentos.
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Al-Sarar, Ali Saeed. "The impact of the variable flow rate application system on pesticide dose-transfer processes and development of resistance to insecticides in fall armyworm Spodoptera frugiperda (J. E Smith)." The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1070933281.
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Silva, William Marcos da. "Diversidade dos Cyclopoida (Copepoda, Crustácea) de água doce do estado de São Paulo: taxonomia, ecologia e genética." Universidade Federal de São Carlos, 2003. https://repositorio.ufscar.br/handle/ufscar/1765.
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Previous issue date: 2003-07-30Universidade Federal de Minas Gerais
In the present work, the diversity of the Copepoda Cyclopoida from Sao Paulo State was studied. Samples of zooplankton were collected along with water samples were collected in 22 Hydrographic Management Units (UHGRH) of the State. Different environments, such as Reservoirs, Ponds, and Rivers were sampled totalizing 207 water bodies. All of them were positioned by using GPS. Samples of zooplankton were collected using net with 68µm of mesh size. Vertical hauls were performed in limnetic zone, while in littoral zone horizontal hauls and bucket were used. The plankton samples were preserved in formaldehyde 4%. Identifications of Cyclopoida were achieved using adult females forms. The data thus obtained were submitted to the SinBiota World Web Site where Geographical distribution of Cyclopoida was plotted to the map of the Sao Paulo State using the geographic coordinates obtained from GPS. It was compared the biodiversity and abundance of Cyclopoida in Reservoirs with different trophic degrees located in the Basins of rivers Tietê, Ribeira do Iguape, and Grande. ITS 2 sequence of DNA of the Cyclopoida was obtained for the following species: Thermcyclops decipiens, Thermocyclops inversus, Mesocyclops ogunnus and Mesocyclops longisetus longisetus. Number of chromosomes Mesocyclops longisetus longisetus was counted and a chromatin diminution observed. New Cyclopoida species, Thermocyclops n. sp., was first described and five species, Acanthocyclops robustus, Eucyclops elegans, Eucyclops cf. prinophorus, Microcyclops alius, and Mesocyclops aspericornis, were newly registered in the São Paulo State. With this, there are now 10 genera and 26 species recorded in the Sao Paulo State. A key to genres and species in the São Paulo State was proposed based on morphological differences, including draws from the anatomical characteristics which are important for taxonomy. It was proved that species identified earlier in the São Paulo State as Mesocyclops kieferi and Mesocyclops brasilianus were actually confused with species Mesocyclops ogunnus and Mesocyclops meridianus, respectively. It was found that Pacyclops fimbriatus, recorded earlier in the Broa Reservoir, is actually Pacyclops chiltoni inhabiting Sao Paulo water bodies. Thermocyclops decipiens was found to be the most broadly distributed species of the Cyclopoid recorded in 20 of 22 hydrographic units followed by Mesocyclops longisetus longisetus recorded in 16 units and Thermocyclops mintus, Mesocyclops ogunnus and Mesocyclops meridianus recorded in 15 units. Based on our observations, we concluded that, in contrast to the common opinion, highly eutrophicated Reservoirs present the highest species richness and distribution equitability as compared to oligotrophic ones. It was found that Acanthocyclops robustus, Mesocyclops ogunnus, and Thermocyclops inversus present the high abundance in eutrophic systems, along with Thermocyclops decipiens. On the other hand, Thermocyclops n. sp., as well as Thermocyclops minutus, have presented the high abundance in systems less eutrophicated streams. We found that the newly described species Thermocyclops n. sp is distributed specifically in the Basins of Ribeira do Iguape and Paraíba do Sul. ITS 2 sequence of DNA varied greatly between different species, while no significantly variation was observed between specimens of the same species. Mesocyclops longisetus longisetus was found to possess 2n = 14 chromosomes and presented the chromatin diminution in 4th egg cleavage. The present study clearly shows that the exhaustive study of the biodiversity needs the use complex approaches as taxonomy, ecology and genetics. This work is part of Biota/FAPESP program, the virtual institute of biodiversity.
Com o objetivo de conhecer a biodiversidade de Copepoda Cyclopoida do Estado de São Paulo foi realizado coletas de água em suas 22 unidades hidrográficas de gerenciamento de recursos hídricos (UHGRH). As coletas foram realizadas em diversos sistemas incluído represas, lagoas e rios, totalizando 207 corpos de água e todos georeferenciados com GPS. As amostras de Cyclopoida foram coletadas com rede de 68 µm de poro em arrastos verticais na zona limnética e coletados com equipamentos apropriados na região litorânea. As amostras foram preservadas em formol 4%. A identificação das espécies de Cyclopoida foi realizada analisando as fêmeas adultas. A distribuição das espécies foi realizada por submissão dos dados georreferenciados para plataforma do SinBiota/FAPESP. A biodiversidade e abundância das espécies em reservatórios de diferentes graus de trofia foi realizado para as represas do Rio Tietê, da Unidade Ribeira do Iguape e da Unidade Pardo Grande. Foi realizado pela primeira vez no Brasil a extração e sequenciamento do DNA de Cyclopoida. Foi seqüenciado o DNA do ITS 2 das espécies: Thermocyclops decipiens, Thermocyclops inversus, Mesocyclops ogunnus e Mesocyclops longisetus longisetus. Foi realizado também pela primeira vez no Brazil a citogenética para Cyclopoida, sendo utilizada a espécie Mesocyclops longisetus longisetus. Foi registrado para o Estado de São Paulo mais 6 espécies, sendo uma espécie nova Thermocyclops n. sp. e 5 novos registros, Acanthocyclops robustus, Eucyclops elegans, Eucyclops cf. prinophorus, Microcyclops alius e Mesocyclops aspericornis. Totalizando para o Estado de São Paulo 10 gêneros e 26 espécies. Com base nas diferenças morfológicas foi elaborado uma chave de identificação para gêneros e espécies do Estado de São Paulo com ilustrações das partes anatômicas de interesse. Foi constatado que as espécies Mesocyclops ogunnus e Mesocyclops meridianus são respectivamente M. kieferi e M. brasilianus anteriormente identificadas no Estado de São Paulo. Do gênero Paracyclops a espécie P. chiltoni encontrada nos corpos de água do Estado é a mesma encontrada na represa do Broa identificada como P. fimbiratus. As espécies mais amplamente distribuídas nas 22 UHGRHs foi Thermocyclops decipiens presente em 20 UHGRH seguida por Mesocyclops longisetus longisetus presente em 16 UHGRHs e Thermvocyclops minutus, Mesocyclops ogunnus, Mesocyclops meridianus e com presença em 15 UHGRHs. As represas mais eutrofizadas apresentaram uma maior riqueza e densidades similares de distribuição das espécies de Cyclopoida do que as represas menos eutrofizadas. As espécies Thermocyclops decipiens, Mesocyclops ogunnus, Acantocyclops robustus e Thermocyclops inversus foram mais abundantes em sistemas eutrofizados enquanto que as espéices Thermocyclops minutus e Thermocyclops n. sp. apresentaram maior abundância nos sistemas menos eutrofizados. A espécie Thermocyclops igaupensis n.sp. teve sua distribuição geográfica restrita as Unidades Ribeira do Iguape e Paraíba do Sul. As seqüências do DNA do ITS2 apresentou alta variação entre as diferentes espécies e baixa ou nenhuma variação entre as mesmas espécies. A análise citogenética feita na espécie Mesocyclops longisetus longisetus mostrou que a espécie possui 2n = 14 cromossomos e apresenta perda de cromatina a partir da 4a clivagem do ovo. Os estudos mostraram que a biodiversidade é melhor conhecida se estudada em diversos aspectos tais como taxonômico, ecológico e genético. Esta tese fez parte do Programa BIOTA/FAPESP o instituto virtual da biodiversidade.